* [PATCH v5 00/31] block layer: split block APIs in global state and I/O
@ 2021-11-24 6:43 Emanuele Giuseppe Esposito
2021-11-24 6:43 ` [PATCH v5 01/31] main-loop.h: introduce qemu_in_main_thread() Emanuele Giuseppe Esposito
` (31 more replies)
0 siblings, 32 replies; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:43 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
Currently, block layer APIs like block.h contain a mix of
functions that are either running in the main loop and under the
BQL, or are thread-safe functions and run in iothreads performing I/O.
The functions running under BQL also take care of modifying the
block graph, by using drain and/or aio_context_acquire/release.
This makes it very confusing to understand where each function
runs, and what assumptions it provided with regards to thread
safety.
We call the functions running under BQL "global state (GS) API", and
distinguish them from the thread-safe "I/O API".
The aim of this series is to split the relevant block headers in
global state and I/O sub-headers. The division will be done in
this way:
header.h will be split in header-global-state.h, header-io.h and
header-common.h. The latter will just contain the data structures
needed by header-global-state and header-io, and common helpers
that are neither in GS nor in I/O. header.h will remain for
legacy and to avoid changing all includes in all QEMU c files,
but will only include the two new headers. No function shall be
added in header.c .
Once we split all relevant headers, it will be much easier to see what
uses the AioContext lock and remove it, which is the overall main
goal of this and other series that I posted/will post.
In addition to splitting the relevant headers shown in this series,
it is also very helpful splitting the function pointers in some
block structures, to understand what runs under AioContext lock and
what doesn't. This is what patches 21-27 do.
Each function in the GS API will have an assertion, checking
that it is always running under BQL.
I/O functions are instead thread safe (or so should be), meaning
that they *can* run under BQL, but also in an iothread in another
AioContext. Therefore they do not provide any assertion, and
need to be audited manually to verify the correctness.
Adding assetions has helped finding 2 bugs already, as shown in
my series "Migration: fix missing iothread locking".
Tested this series by running unit tests, qemu-iotests and qtests
(x86_64).
Some functions in the GS API are used everywhere but not
properly tested. Therefore their assertion is never actually run in
the tests, so despite my very careful auditing, it is not impossible
to exclude that some will trigger while actually using QEMU.
Patch 1 introduces qemu_in_main_thread(), the function used in
all assertions. This had to be introduced otherwise all unit tests
would fail, since they run in the main loop but use the code in
stubs/iothread.c
Patches 2-27 (with the exception of patch 9-10, that are an additional
assert) are all structured in the same way: first we split the header
and in the next (or same, if small) patch we add assertions.
Patch 28-31 take care instead of the block layer permission API,
fixing some bugs where they are used in I/O functions.
Next steps once this get reviewed:
1) audit the GS API and replace the AioContext lock with drains,
or remove them when not necessary (requires further discussion).
2) [optional as it should be already the case] audit the I/O API
and check that thread safety is guaranteed
In order to keep this series a little bit smaller, move some
refactoring patches in another series, "block: minor refactoring
in preparation to the block layer API split".
Based-on: <20211124063640.3118897-1-eesposit@redhat.com>
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
v5 -> v6:
* In short, apply all Hanna's comments. More in details,
the following functions in the following headers have been moved:
block-backend:
blk_replace_bs (to gs)
blk_nb_sectors (to io)
blk_name (to io)
blk_set_perm (to io)
blk_get_perm (to io)
blk_drain (to io)
blk_abort_aio_request (to io)
blk_make_empty (to gs)
blk_invalidate_cache (was in io, but had GS assertion)
blk_aio_cancel (to gs)
block:
bdrv_replace_child_bs (to gs)
bdrv_get_device_name (to io)
bdrv_get_device_or_node_name (to io)
bdrv_drained_end_no_poll (to io)
bdrv_block_status (was in io, but had GS assertion)
bdrv_drain (to io)
bdrv_co_drain (to io)
bdrv_make_zero (was in GS, but did not have the assertion)
bdrv_save_vmstate (to io)
bdrv_load_vmstate (to io)
bdrv_aio_cancel_async (to io)
block_int:
bdrv_get_parent_name (to io)
bdrv_apply_subtree_drain (to io)
bdrv_unapply_subtree_drain (to io)
bdrv_co_copy_range_from (was in io, but had GS assertion)
bdrv_co_copy_range_to (was in io, but had GS assertion)
->bdrv_save_vmstate (to io)
->bdrv_load_vmstate (to io)
coding style (assertion after definitions):
bdrv_save_vmstate
bdrv_load_vmstate
block_job_next
block_job_get
new patches:
block.c: modify .attach and .detach callbacks of child_of_bds
introduce pre_run as JobDriver callback to handle
bdrv_co_amend usage of permission function
leave blk_set/get_perm as a TODO in fuse.c
make sure bdrv_co_invalidate_cache does not use permissions
if BQL is not held
minor changes:
put back TODO for include block/block.h in block-backend-common.h
rebase on kwolf/block branch
modify where are used assert_bdrv_graph_writable, due to rebase
v4 -> v5:
* Moved the following functions from block-io to
block-global-state (+ assertion):
- bdrv_apply_auto_read_only
- bdrv_can_set_read_only
* Moved the following functions from block-backend-io to
block-backend-global-state (+ assertion):
- blk_ioctl
* added patch 4 to distinguish assertions added to static functions
in block.c
* block/coroutines: it seems that blk_co_do_ioctl and
blk_do_ioctl are global state too
v3 -> v4:
* blockdev.h (patch 14): blockdev_mark_auto_del, blockdev_auto_del
and blk_legacy_dinfo as GS API.
* add copyright header to block.h, block-io.h and block-global-state.h
* rebase on current master (c5b2f55981)
v2 -> v3:
* rename "graph API" into "global state API"
* change order of patches, block.h comes before block-backend.h
* change GS and I/O comment headers to avoid redundancy, all other
headers refer to block-global-state.h and block-io.h
* fix typo on GS and I/O headers
* use assert instead of g_assert
* move bdrv_pwrite_sync, bdrv_block_status and bdrv_co_copy_range_{from/to}
to the I/O API
* change assert_bdrv_graph_writable implementation, since we need
to introduce additional drains
* remove transactions API split
* add preparation patch for blockdev.h (patch 13)
* backup-top -> copy-on-write
* change I/O comment in job.h into a better meaningful explanation
* fix all warnings given by checkpatch, mostly due to /* */ to be
split in separate lines
* rebase on current master (c09124dcb8), and split the following new functions:
blk_replace_bs (I/O)
bdrv_bsc_is_data (I/O)
bdrv_bsc_invalidate_range (I/O)
bdrv_bsc_fill (I/O)
bdrv_new_open_driver_opts (GS)
blk_get_max_hw_iov (I/O)
they are all added in patches 4 and 6.
v1 -> v2:
* remove the iothread locking bug fix, and send it as separate patch
* rename graph API -> global state API
* better documented patch 1 (qemu_in_main_thread)
* add and split all other block layer headers
* fix warnings given by checkpatch on multiline comments
Emanuele Giuseppe Esposito (31):
main-loop.h: introduce qemu_in_main_thread()
include/block/block: split header into I/O and global state API
assertions for block global state API
include/sysemu/block-backend: split header into I/O and global state
(GS) API
block-backend: special comments for blk_set/get_perm due to fuse
block/block-backend.c: assertions for block-backend
include/block/block_int: split header into I/O and global state API
assertions for block_int global state API
block: introduce assert_bdrv_graph_writable
block.c: modify .attach and .detach callbacks of child_of_bds
include/block/blockjob_int.h: split header into I/O and GS API
assertions for blockjob_int.h
block.c: add assertions to static functions
include/block/blockjob.h: global state API
assertions for blockjob.h global state API
include/sysemu/blockdev.h: global state API
assertions for blockdev.h global state API
include/block/snapshot: global state API + assertions
block/copy-before-write.h: global state API + assertions
block/coroutines: I/O API
block_int-common.h: split function pointers in BlockDriver
block_int-common.h: assertion in the callers of BlockDriver function
pointers
block_int-common.h: split function pointers in BdrvChildClass
block_int-common.h: assertions in the callers of BdrvChildClass
function pointers
block-backend-common.h: split function pointers in BlockDevOps
job.h: split function pointers in JobDriver
job.h: assertions in the callers of JobDriver funcion pointers
block.c: assert BQL lock held in bdrv_co_invalidate_cache
jobs: introduce pre_run function in JobDriver
crypto: delegate permission functions to JobDriver .pre_run
block.c: assertions to the block layer permissions API
block/copy-before-write.h | 7 +
block/coroutines.h | 6 +
include/block/block-common.h | 380 +++++
include/block/block-global-state.h | 271 ++++
include/block/block-io.h | 322 ++++
include/block/block.h | 878 +----------
include/block/block_int-common.h | 1204 +++++++++++++++
include/block/block_int-global-state.h | 323 ++++
include/block/block_int-io.h | 167 +++
include/block/block_int.h | 1475 +------------------
include/block/blockjob.h | 9 +
include/block/blockjob_int.h | 28 +
include/block/snapshot.h | 13 +-
include/qemu/job.h | 31 +
include/qemu/main-loop.h | 13 +
include/sysemu/block-backend-common.h | 102 ++
include/sysemu/block-backend-global-state.h | 121 ++
include/sysemu/block-backend-io.h | 139 ++
include/sysemu/block-backend.h | 269 +---
include/sysemu/blockdev.h | 13 +-
block.c | 272 +++-
block/amend.c | 20 +
block/backup.c | 1 +
block/block-backend.c | 108 +-
block/commit.c | 4 +
block/copy-before-write.c | 2 +
block/create.c | 10 +
block/crypto.c | 18 +-
block/dirty-bitmap.c | 1 +
block/export/fuse.c | 16 +-
block/io.c | 26 +
block/mirror.c | 4 +
block/monitor/bitmap-qmp-cmds.c | 6 +
block/snapshot.c | 28 +
block/stream.c | 2 +
blockdev.c | 28 +
blockjob.c | 14 +
job.c | 23 +
migration/savevm.c | 2 +
softmmu/cpus.c | 5 +
softmmu/qdev-monitor.c | 2 +
stubs/iothread-lock.c | 5 +
block/meson.build | 7 +-
43 files changed, 3758 insertions(+), 2617 deletions(-)
create mode 100644 include/block/block-common.h
create mode 100644 include/block/block-global-state.h
create mode 100644 include/block/block-io.h
create mode 100644 include/block/block_int-common.h
create mode 100644 include/block/block_int-global-state.h
create mode 100644 include/block/block_int-io.h
create mode 100644 include/sysemu/block-backend-common.h
create mode 100644 include/sysemu/block-backend-global-state.h
create mode 100644 include/sysemu/block-backend-io.h
--
2.27.0
^ permalink raw reply [flat|nested] 66+ messages in thread
* [PATCH v5 01/31] main-loop.h: introduce qemu_in_main_thread()
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
@ 2021-11-24 6:43 ` Emanuele Giuseppe Esposito
2021-11-24 6:43 ` [PATCH v5 02/31] include/block/block: split header into I/O and global state API Emanuele Giuseppe Esposito
` (30 subsequent siblings)
31 siblings, 0 replies; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:43 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
When invoked from the main loop, this function is the same
as qemu_mutex_iothread_locked, and returns true if the BQL is held.
When invoked from iothreads or tests, it returns true only
if the current AioContext is the Main Loop.
This essentially just extends qemu_mutex_iothread_locked to work
also in unit tests or other users like storage-daemon, that run
in the Main Loop but end up using the implementation in
stubs/iothread-lock.c.
Using qemu_mutex_iothread_locked in unit tests defaults to false
because they use the implementation in stubs/iothread-lock,
making all assertions added in next patches fail despite the
AioContext is still the main loop.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
include/qemu/main-loop.h | 13 +++++++++++++
softmmu/cpus.c | 5 +++++
stubs/iothread-lock.c | 5 +++++
3 files changed, 23 insertions(+)
diff --git a/include/qemu/main-loop.h b/include/qemu/main-loop.h
index 8dbc6fcb89..6b8fa57c5d 100644
--- a/include/qemu/main-loop.h
+++ b/include/qemu/main-loop.h
@@ -245,6 +245,19 @@ AioContext *iohandler_get_aio_context(void);
*/
bool qemu_mutex_iothread_locked(void);
+/**
+ * qemu_in_main_thread: same as qemu_mutex_iothread_locked when
+ * softmmu/cpus.c implementation is linked. Otherwise this function
+ * checks that the current AioContext is the global AioContext
+ * (main loop).
+ *
+ * This is useful when checking that the BQL is held, to avoid
+ * returning false when invoked by unit tests or other users like
+ * storage-daemon that end up using stubs/iothread-lock.c
+ * implementation.
+ */
+bool qemu_in_main_thread(void);
+
/**
* qemu_mutex_lock_iothread: Lock the main loop mutex.
*
diff --git a/softmmu/cpus.c b/softmmu/cpus.c
index 071085f840..3f61a3c31d 100644
--- a/softmmu/cpus.c
+++ b/softmmu/cpus.c
@@ -481,6 +481,11 @@ bool qemu_mutex_iothread_locked(void)
return iothread_locked;
}
+bool qemu_in_main_thread(void)
+{
+ return qemu_mutex_iothread_locked();
+}
+
/*
* The BQL is taken from so many places that it is worth profiling the
* callers directly, instead of funneling them all through a single function.
diff --git a/stubs/iothread-lock.c b/stubs/iothread-lock.c
index 5b45b7fc8b..ff7386e42c 100644
--- a/stubs/iothread-lock.c
+++ b/stubs/iothread-lock.c
@@ -6,6 +6,11 @@ bool qemu_mutex_iothread_locked(void)
return false;
}
+bool qemu_in_main_thread(void)
+{
+ return qemu_get_current_aio_context() == qemu_get_aio_context();
+}
+
void qemu_mutex_lock_iothread_impl(const char *file, int line)
{
}
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 02/31] include/block/block: split header into I/O and global state API
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
2021-11-24 6:43 ` [PATCH v5 01/31] main-loop.h: introduce qemu_in_main_thread() Emanuele Giuseppe Esposito
@ 2021-11-24 6:43 ` Emanuele Giuseppe Esposito
2021-11-24 6:43 ` [PATCH v5 03/31] assertions for block " Emanuele Giuseppe Esposito
` (29 subsequent siblings)
31 siblings, 0 replies; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:43 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
block.h currently contains a mix of functions:
some of them run under the BQL and modify the block layer graph,
others are instead thread-safe and perform I/O in iothreads.
It is not easy to understand which function is part of which
group (I/O vs GS), and this patch aims to clarify it.
The "GS" functions need the BQL, and often use
aio_context_acquire/release and/or drain to be sure they
can modify the graph safely.
The I/O function are instead thread safe, and can run in
any AioContext.
By splitting the header in two files, block-io.h
and block-global-state.h we have a clearer view on what
needs what kind of protection. block-common.h
contains common structures shared by both headers.
block.h is left there for legacy and to avoid changing
all includes in all c files that use the block APIs.
Assertions are added in the next patch.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
include/block/block-common.h | 380 +++++++++++++
include/block/block-global-state.h | 271 +++++++++
include/block/block-io.h | 322 +++++++++++
include/block/block.h | 878 +----------------------------
block.c | 3 +
block/meson.build | 7 +-
6 files changed, 1004 insertions(+), 857 deletions(-)
create mode 100644 include/block/block-common.h
create mode 100644 include/block/block-global-state.h
create mode 100644 include/block/block-io.h
diff --git a/include/block/block-common.h b/include/block/block-common.h
new file mode 100644
index 0000000000..dfaa73ac70
--- /dev/null
+++ b/include/block/block-common.h
@@ -0,0 +1,380 @@
+#ifndef BLOCK_COMMON_H
+#define BLOCK_COMMON_H
+
+#include "block/aio.h"
+#include "block/aio-wait.h"
+#include "qemu/iov.h"
+#include "qemu/coroutine.h"
+#include "block/accounting.h"
+#include "block/dirty-bitmap.h"
+#include "block/blockjob.h"
+#include "qemu/hbitmap.h"
+#include "qemu/transactions.h"
+
+/*
+ * generated_co_wrapper
+ *
+ * Function specifier, which does nothing but mark functions to be
+ * generated by scripts/block-coroutine-wrapper.py
+ *
+ * Read more in docs/devel/block-coroutine-wrapper.rst
+ */
+#define generated_co_wrapper
+
+/* block.c */
+typedef struct BlockDriver BlockDriver;
+typedef struct BdrvChild BdrvChild;
+typedef struct BdrvChildClass BdrvChildClass;
+
+typedef struct BlockDriverInfo {
+ /* in bytes, 0 if irrelevant */
+ int cluster_size;
+ /* offset at which the VM state can be saved (0 if not possible) */
+ int64_t vm_state_offset;
+ bool is_dirty;
+ /*
+ * True if this block driver only supports compressed writes
+ */
+ bool needs_compressed_writes;
+} BlockDriverInfo;
+
+typedef struct BlockFragInfo {
+ uint64_t allocated_clusters;
+ uint64_t total_clusters;
+ uint64_t fragmented_clusters;
+ uint64_t compressed_clusters;
+} BlockFragInfo;
+
+typedef enum {
+ BDRV_REQ_COPY_ON_READ = 0x1,
+ BDRV_REQ_ZERO_WRITE = 0x2,
+
+ /*
+ * The BDRV_REQ_MAY_UNMAP flag is used in write_zeroes requests to indicate
+ * that the block driver should unmap (discard) blocks if it is guaranteed
+ * that the result will read back as zeroes. The flag is only passed to the
+ * driver if the block device is opened with BDRV_O_UNMAP.
+ */
+ BDRV_REQ_MAY_UNMAP = 0x4,
+
+ BDRV_REQ_FUA = 0x10,
+ BDRV_REQ_WRITE_COMPRESSED = 0x20,
+
+ /*
+ * Signifies that this write request will not change the visible disk
+ * content.
+ */
+ BDRV_REQ_WRITE_UNCHANGED = 0x40,
+
+ /*
+ * Forces request serialisation. Use only with write requests.
+ */
+ BDRV_REQ_SERIALISING = 0x80,
+
+ /*
+ * Execute the request only if the operation can be offloaded or otherwise
+ * be executed efficiently, but return an error instead of using a slow
+ * fallback.
+ */
+ BDRV_REQ_NO_FALLBACK = 0x100,
+
+ /*
+ * BDRV_REQ_PREFETCH makes sense only in the context of copy-on-read
+ * (i.e., together with the BDRV_REQ_COPY_ON_READ flag or when a COR
+ * filter is involved), in which case it signals that the COR operation
+ * need not read the data into memory (qiov) but only ensure they are
+ * copied to the top layer (i.e., that COR operation is done).
+ */
+ BDRV_REQ_PREFETCH = 0x200,
+
+ /*
+ * If we need to wait for other requests, just fail immediately. Used
+ * only together with BDRV_REQ_SERIALISING.
+ */
+ BDRV_REQ_NO_WAIT = 0x400,
+
+ /* Mask of valid flags */
+ BDRV_REQ_MASK = 0x7ff,
+} BdrvRequestFlags;
+
+#define BDRV_O_NO_SHARE 0x0001 /* don't share permissions */
+#define BDRV_O_RDWR 0x0002
+#define BDRV_O_RESIZE 0x0004 /* request permission for resizing the node */
+#define BDRV_O_SNAPSHOT 0x0008 /* open the file read only and save
+ writes in a snapshot */
+#define BDRV_O_TEMPORARY 0x0010 /* delete the file after use */
+#define BDRV_O_NOCACHE 0x0020 /* do not use the host page cache */
+#define BDRV_O_NATIVE_AIO 0x0080 /* use native AIO instead of the
+ thread pool */
+#define BDRV_O_NO_BACKING 0x0100 /* don't open the backing file */
+#define BDRV_O_NO_FLUSH 0x0200 /* disable flushing on this disk */
+#define BDRV_O_COPY_ON_READ 0x0400 /* copy read backing sectors into image */
+#define BDRV_O_INACTIVE 0x0800 /* consistency hint for migration handoff */
+#define BDRV_O_CHECK 0x1000 /* open solely for consistency check */
+#define BDRV_O_ALLOW_RDWR 0x2000 /* allow reopen to change from r/o to r/w */
+#define BDRV_O_UNMAP 0x4000 /* execute guest UNMAP/TRIM operations */
+#define BDRV_O_PROTOCOL 0x8000 /* if no block driver is explicitly given:
+ select an appropriate protocol driver,
+ ignoring the format layer */
+#define BDRV_O_NO_IO 0x10000 /* don't initialize for I/O */
+#define BDRV_O_AUTO_RDONLY 0x20000 /* degrade to read-only if opening
+ read-write fails */
+#define BDRV_O_IO_URING 0x40000 /* use io_uring instead of the thread pool */
+
+#define BDRV_O_CACHE_MASK (BDRV_O_NOCACHE | BDRV_O_NO_FLUSH)
+
+
+/* Option names of options parsed by the block layer */
+
+#define BDRV_OPT_CACHE_WB "cache.writeback"
+#define BDRV_OPT_CACHE_DIRECT "cache.direct"
+#define BDRV_OPT_CACHE_NO_FLUSH "cache.no-flush"
+#define BDRV_OPT_READ_ONLY "read-only"
+#define BDRV_OPT_AUTO_READ_ONLY "auto-read-only"
+#define BDRV_OPT_DISCARD "discard"
+#define BDRV_OPT_FORCE_SHARE "force-share"
+
+
+#define BDRV_SECTOR_BITS 9
+#define BDRV_SECTOR_SIZE (1ULL << BDRV_SECTOR_BITS)
+
+#define BDRV_REQUEST_MAX_SECTORS MIN_CONST(SIZE_MAX >> BDRV_SECTOR_BITS, \
+ INT_MAX >> BDRV_SECTOR_BITS)
+#define BDRV_REQUEST_MAX_BYTES (BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS)
+
+/*
+ * We want allow aligning requests and disk length up to any 32bit alignment
+ * and don't afraid of overflow.
+ * To achieve it, and in the same time use some pretty number as maximum disk
+ * size, let's define maximum "length" (a limit for any offset/bytes request and
+ * for disk size) to be the greatest power of 2 less than INT64_MAX.
+ */
+#define BDRV_MAX_ALIGNMENT (1L << 30)
+#define BDRV_MAX_LENGTH (QEMU_ALIGN_DOWN(INT64_MAX, BDRV_MAX_ALIGNMENT))
+
+/*
+ * Allocation status flags for bdrv_block_status() and friends.
+ *
+ * Public flags:
+ * BDRV_BLOCK_DATA: allocation for data at offset is tied to this layer
+ * BDRV_BLOCK_ZERO: offset reads as zero
+ * BDRV_BLOCK_OFFSET_VALID: an associated offset exists for accessing raw data
+ * BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
+ * layer rather than any backing, set by block layer
+ * BDRV_BLOCK_EOF: the returned pnum covers through end of file for this
+ * layer, set by block layer
+ *
+ * Internal flags:
+ * BDRV_BLOCK_RAW: for use by passthrough drivers, such as raw, to request
+ * that the block layer recompute the answer from the returned
+ * BDS; must be accompanied by just BDRV_BLOCK_OFFSET_VALID.
+ * BDRV_BLOCK_RECURSE: request that the block layer will recursively search for
+ * zeroes in file child of current block node inside
+ * returned region. Only valid together with both
+ * BDRV_BLOCK_DATA and BDRV_BLOCK_OFFSET_VALID. Should not
+ * appear with BDRV_BLOCK_ZERO.
+ *
+ * If BDRV_BLOCK_OFFSET_VALID is set, the map parameter represents the
+ * host offset within the returned BDS that is allocated for the
+ * corresponding raw guest data. However, whether that offset
+ * actually contains data also depends on BDRV_BLOCK_DATA, as follows:
+ *
+ * DATA ZERO OFFSET_VALID
+ * t t t sectors read as zero, returned file is zero at offset
+ * t f t sectors read as valid from file at offset
+ * f t t sectors preallocated, read as zero, returned file not
+ * necessarily zero at offset
+ * f f t sectors preallocated but read from backing_hd,
+ * returned file contains garbage at offset
+ * t t f sectors preallocated, read as zero, unknown offset
+ * t f f sectors read from unknown file or offset
+ * f t f not allocated or unknown offset, read as zero
+ * f f f not allocated or unknown offset, read from backing_hd
+ */
+#define BDRV_BLOCK_DATA 0x01
+#define BDRV_BLOCK_ZERO 0x02
+#define BDRV_BLOCK_OFFSET_VALID 0x04
+#define BDRV_BLOCK_RAW 0x08
+#define BDRV_BLOCK_ALLOCATED 0x10
+#define BDRV_BLOCK_EOF 0x20
+#define BDRV_BLOCK_RECURSE 0x40
+
+typedef QTAILQ_HEAD(BlockReopenQueue, BlockReopenQueueEntry) BlockReopenQueue;
+
+typedef struct BDRVReopenState {
+ BlockDriverState *bs;
+ int flags;
+ BlockdevDetectZeroesOptions detect_zeroes;
+ bool backing_missing;
+ BlockDriverState *old_backing_bs; /* keep pointer for permissions update */
+ BlockDriverState *old_file_bs; /* keep pointer for permissions update */
+ QDict *options;
+ QDict *explicit_options;
+ void *opaque;
+} BDRVReopenState;
+
+/*
+ * Block operation types
+ */
+typedef enum BlockOpType {
+ BLOCK_OP_TYPE_BACKUP_SOURCE,
+ BLOCK_OP_TYPE_BACKUP_TARGET,
+ BLOCK_OP_TYPE_CHANGE,
+ BLOCK_OP_TYPE_COMMIT_SOURCE,
+ BLOCK_OP_TYPE_COMMIT_TARGET,
+ BLOCK_OP_TYPE_DATAPLANE,
+ BLOCK_OP_TYPE_DRIVE_DEL,
+ BLOCK_OP_TYPE_EJECT,
+ BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT,
+ BLOCK_OP_TYPE_INTERNAL_SNAPSHOT,
+ BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE,
+ BLOCK_OP_TYPE_MIRROR_SOURCE,
+ BLOCK_OP_TYPE_MIRROR_TARGET,
+ BLOCK_OP_TYPE_RESIZE,
+ BLOCK_OP_TYPE_STREAM,
+ BLOCK_OP_TYPE_REPLACE,
+ BLOCK_OP_TYPE_MAX,
+} BlockOpType;
+
+/* Block node permission constants */
+enum {
+ /**
+ * A user that has the "permission" of consistent reads is guaranteed that
+ * their view of the contents of the block device is complete and
+ * self-consistent, representing the contents of a disk at a specific
+ * point.
+ *
+ * For most block devices (including their backing files) this is true, but
+ * the property cannot be maintained in a few situations like for
+ * intermediate nodes of a commit block job.
+ */
+ BLK_PERM_CONSISTENT_READ = 0x01,
+
+ /** This permission is required to change the visible disk contents. */
+ BLK_PERM_WRITE = 0x02,
+
+ /**
+ * This permission (which is weaker than BLK_PERM_WRITE) is both enough and
+ * required for writes to the block node when the caller promises that
+ * the visible disk content doesn't change.
+ *
+ * As the BLK_PERM_WRITE permission is strictly stronger, either is
+ * sufficient to perform an unchanging write.
+ */
+ BLK_PERM_WRITE_UNCHANGED = 0x04,
+
+ /** This permission is required to change the size of a block node. */
+ BLK_PERM_RESIZE = 0x08,
+
+ /**
+ * This permission is required to change the node that this BdrvChild
+ * points to.
+ */
+ BLK_PERM_GRAPH_MOD = 0x10,
+
+ BLK_PERM_ALL = 0x1f,
+
+ DEFAULT_PERM_PASSTHROUGH = BLK_PERM_CONSISTENT_READ
+ | BLK_PERM_WRITE
+ | BLK_PERM_WRITE_UNCHANGED
+ | BLK_PERM_RESIZE,
+
+ DEFAULT_PERM_UNCHANGED = BLK_PERM_ALL & ~DEFAULT_PERM_PASSTHROUGH,
+};
+
+/*
+ * Flags that parent nodes assign to child nodes to specify what kind of
+ * role(s) they take.
+ *
+ * At least one of DATA, METADATA, FILTERED, or COW must be set for
+ * every child.
+ */
+enum BdrvChildRoleBits {
+ /*
+ * This child stores data.
+ * Any node may have an arbitrary number of such children.
+ */
+ BDRV_CHILD_DATA = (1 << 0),
+
+ /*
+ * This child stores metadata.
+ * Any node may have an arbitrary number of metadata-storing
+ * children.
+ */
+ BDRV_CHILD_METADATA = (1 << 1),
+
+ /*
+ * A child that always presents exactly the same visible data as
+ * the parent, e.g. by virtue of the parent forwarding all reads
+ * and writes.
+ * This flag is mutually exclusive with DATA, METADATA, and COW.
+ * Any node may have at most one filtered child at a time.
+ */
+ BDRV_CHILD_FILTERED = (1 << 2),
+
+ /*
+ * Child from which to read all data that isn't allocated in the
+ * parent (i.e., the backing child); such data is copied to the
+ * parent through COW (and optionally COR).
+ * This field is mutually exclusive with DATA, METADATA, and
+ * FILTERED.
+ * Any node may have at most one such backing child at a time.
+ */
+ BDRV_CHILD_COW = (1 << 3),
+
+ /*
+ * The primary child. For most drivers, this is the child whose
+ * filename applies best to the parent node.
+ * Any node may have at most one primary child at a time.
+ */
+ BDRV_CHILD_PRIMARY = (1 << 4),
+
+ /* Useful combination of flags */
+ BDRV_CHILD_IMAGE = BDRV_CHILD_DATA
+ | BDRV_CHILD_METADATA
+ | BDRV_CHILD_PRIMARY,
+};
+
+/* Mask of BdrvChildRoleBits values */
+typedef unsigned int BdrvChildRole;
+
+typedef struct BdrvCheckResult {
+ int corruptions;
+ int leaks;
+ int check_errors;
+ int corruptions_fixed;
+ int leaks_fixed;
+ int64_t image_end_offset;
+ BlockFragInfo bfi;
+} BdrvCheckResult;
+
+typedef enum {
+ BDRV_FIX_LEAKS = 1,
+ BDRV_FIX_ERRORS = 2,
+} BdrvCheckMode;
+
+typedef struct BlockSizes {
+ uint32_t phys;
+ uint32_t log;
+} BlockSizes;
+
+typedef struct HDGeometry {
+ uint32_t heads;
+ uint32_t sectors;
+ uint32_t cylinders;
+} HDGeometry;
+
+/* Common functions that are neither I/O nor Global State */
+
+int bdrv_parse_aio(const char *mode, int *flags);
+
+int path_has_protocol(const char *path);
+int path_is_absolute(const char *path);
+char *path_combine(const char *base_path, const char *filename);
+
+char *bdrv_get_full_backing_filename_from_filename(const char *backed,
+ const char *backing,
+ Error **errp);
+char *bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp);
+
+#endif /* BLOCK_COMMON_H */
diff --git a/include/block/block-global-state.h b/include/block/block-global-state.h
new file mode 100644
index 0000000000..7a6b065101
--- /dev/null
+++ b/include/block/block-global-state.h
@@ -0,0 +1,271 @@
+/*
+ * QEMU System Emulator block driver
+ *
+ * Copyright (c) 2003 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#ifndef BLOCK_GLOBAL_STATE_H
+#define BLOCK_GLOBAL_STATE_H
+
+#include "block-common.h"
+
+/*
+ * Global state (GS) API. These functions run under the BQL lock.
+ *
+ * If a function modifies the graph, it also uses drain and/or
+ * aio_context_acquire/release to be sure it has unique access.
+ * aio_context locking is needed together with BQL because of
+ * the thread-safe I/O API that concurrently runs and accesses
+ * the graph without the BQL.
+ *
+ * It is important to note that not all of these functions are
+ * necessarily limited to running under the BQL, but they would
+ * require additional auditing and many small thread-safety changes
+ * to move them into the I/O API. Often it's not worth doing that
+ * work since the APIs are only used with the BQL held at the
+ * moment, so they have been placed in the GS API (for now).
+ *
+ * All functions in this header must use this assertion:
+ * assert(qemu_in_main_thread());
+ * to catch when they are accidentally called without the BQL.
+ */
+
+char *bdrv_perm_names(uint64_t perm);
+uint64_t bdrv_qapi_perm_to_blk_perm(BlockPermission qapi_perm);
+
+/* disk I/O throttling */
+void bdrv_init(void);
+void bdrv_init_with_whitelist(void);
+bool bdrv_uses_whitelist(void);
+int bdrv_is_whitelisted(BlockDriver *drv, bool read_only);
+BlockDriver *bdrv_find_protocol(const char *filename,
+ bool allow_protocol_prefix,
+ Error **errp);
+BlockDriver *bdrv_find_format(const char *format_name);
+int bdrv_create(BlockDriver *drv, const char* filename,
+ QemuOpts *opts, Error **errp);
+int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp);
+
+BlockDriverState *bdrv_new(void);
+int bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
+ Error **errp);
+int bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
+ Error **errp);
+int bdrv_replace_child_bs(BdrvChild *child, BlockDriverState *new_bs,
+ Error **errp);
+BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *node_options,
+ int flags, Error **errp);
+int bdrv_drop_filter(BlockDriverState *bs, Error **errp);
+
+int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough);
+int bdrv_parse_discard_flags(const char *mode, int *flags);
+BdrvChild *bdrv_open_child(const char *filename,
+ QDict *options, const char *bdref_key,
+ BlockDriverState *parent,
+ const BdrvChildClass *child_class,
+ BdrvChildRole child_role,
+ bool allow_none, Error **errp);
+BlockDriverState *bdrv_open_blockdev_ref(BlockdevRef *ref, Error **errp);
+int bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
+ Error **errp);
+int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
+ const char *bdref_key, Error **errp);
+BlockDriverState *bdrv_open(const char *filename, const char *reference,
+ QDict *options, int flags, Error **errp);
+BlockDriverState *bdrv_new_open_driver_opts(BlockDriver *drv,
+ const char *node_name,
+ QDict *options, int flags,
+ Error **errp);
+BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name,
+ int flags, Error **errp);
+BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
+ BlockDriverState *bs, QDict *options,
+ bool keep_old_opts);
+void bdrv_reopen_queue_free(BlockReopenQueue *bs_queue);
+int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp);
+int bdrv_reopen(BlockDriverState *bs, QDict *opts, bool keep_old_opts,
+ Error **errp);
+int bdrv_reopen_set_read_only(BlockDriverState *bs, bool read_only,
+ Error **errp);
+int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags);
+BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
+ const char *backing_file);
+void bdrv_refresh_filename(BlockDriverState *bs);
+void bdrv_refresh_limits(BlockDriverState *bs, Transaction *tran, Error **errp);
+int bdrv_commit(BlockDriverState *bs);
+int bdrv_make_empty(BdrvChild *c, Error **errp);
+int bdrv_change_backing_file(BlockDriverState *bs, const char *backing_file,
+ const char *backing_fmt, bool warn);
+void bdrv_register(BlockDriver *bdrv);
+int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base,
+ const char *backing_file_str);
+BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
+ BlockDriverState *bs);
+BlockDriverState *bdrv_find_base(BlockDriverState *bs);
+bool bdrv_is_backing_chain_frozen(BlockDriverState *bs, BlockDriverState *base,
+ Error **errp);
+int bdrv_freeze_backing_chain(BlockDriverState *bs, BlockDriverState *base,
+ Error **errp);
+void bdrv_unfreeze_backing_chain(BlockDriverState *bs, BlockDriverState *base);
+
+/*
+ * The units of offset and total_work_size may be chosen arbitrarily by the
+ * block driver; total_work_size may change during the course of the amendment
+ * operation
+ */
+typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset,
+ int64_t total_work_size, void *opaque);
+int bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts,
+ BlockDriverAmendStatusCB *status_cb, void *cb_opaque,
+ bool force,
+ Error **errp);
+
+/* check if a named node can be replaced when doing drive-mirror */
+BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
+ const char *node_name, Error **errp);
+
+/* async block I/O */
+void bdrv_aio_cancel(BlockAIOCB *acb);
+void bdrv_invalidate_cache_all(Error **errp);
+
+int bdrv_inactivate_all(void);
+
+int bdrv_flush_all(void);
+void bdrv_close_all(void);
+void bdrv_drain_all_begin(void);
+void bdrv_drain_all_end(void);
+void bdrv_drain_all(void);
+
+#define BDRV_POLL_WHILE(bs, cond) ({ \
+ BlockDriverState *bs_ = (bs); \
+ AIO_WAIT_WHILE(bdrv_get_aio_context(bs_), \
+ cond); })
+
+int bdrv_has_zero_init_1(BlockDriverState *bs);
+int bdrv_has_zero_init(BlockDriverState *bs);
+int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only,
+ bool ignore_allow_rdw, Error **errp);
+int bdrv_apply_auto_read_only(BlockDriverState *bs, const char *errmsg,
+ Error **errp);
+void bdrv_lock_medium(BlockDriverState *bs, bool locked);
+void bdrv_eject(BlockDriverState *bs, bool eject_flag);
+BlockDriverState *bdrv_find_node(const char *node_name);
+BlockDeviceInfoList *bdrv_named_nodes_list(bool flat, Error **errp);
+XDbgBlockGraph *bdrv_get_xdbg_block_graph(Error **errp);
+BlockDriverState *bdrv_lookup_bs(const char *device,
+ const char *node_name,
+ Error **errp);
+bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base);
+BlockDriverState *bdrv_next_node(BlockDriverState *bs);
+BlockDriverState *bdrv_next_all_states(BlockDriverState *bs);
+
+typedef struct BdrvNextIterator {
+ enum {
+ BDRV_NEXT_BACKEND_ROOTS,
+ BDRV_NEXT_MONITOR_OWNED,
+ } phase;
+ BlockBackend *blk;
+ BlockDriverState *bs;
+} BdrvNextIterator;
+
+BlockDriverState *bdrv_first(BdrvNextIterator *it);
+BlockDriverState *bdrv_next(BdrvNextIterator *it);
+void bdrv_next_cleanup(BdrvNextIterator *it);
+
+BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs);
+void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
+ void *opaque, bool read_only);
+int bdrv_get_flags(BlockDriverState *bs);
+char *bdrv_dirname(BlockDriverState *bs, Error **errp);
+
+void bdrv_img_create(const char *filename, const char *fmt,
+ const char *base_filename, const char *base_fmt,
+ char *options, uint64_t img_size, int flags,
+ bool quiet, Error **errp);
+
+void bdrv_ref(BlockDriverState *bs);
+void bdrv_unref(BlockDriverState *bs);
+void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child);
+BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
+ BlockDriverState *child_bs,
+ const char *child_name,
+ const BdrvChildClass *child_class,
+ BdrvChildRole child_role,
+ Error **errp);
+
+bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp);
+void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);
+void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason);
+void bdrv_op_block_all(BlockDriverState *bs, Error *reason);
+void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason);
+bool bdrv_op_blocker_is_empty(BlockDriverState *bs);
+
+int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
+ const char *tag);
+int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag);
+int bdrv_debug_resume(BlockDriverState *bs, const char *tag);
+bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag);
+
+/**
+ * Locks the AioContext of @bs if it's not the current AioContext. This avoids
+ * double locking which could lead to deadlocks: This is a coroutine_fn, so we
+ * know we already own the lock of the current AioContext.
+ *
+ * May only be called in the main thread.
+ */
+void coroutine_fn bdrv_co_lock(BlockDriverState *bs);
+
+/**
+ * Unlocks the AioContext of @bs if it's not the current AioContext.
+ */
+void coroutine_fn bdrv_co_unlock(BlockDriverState *bs);
+
+void bdrv_set_aio_context_ignore(BlockDriverState *bs,
+ AioContext *new_context, GSList **ignore);
+int bdrv_try_set_aio_context(BlockDriverState *bs, AioContext *ctx,
+ Error **errp);
+int bdrv_child_try_set_aio_context(BlockDriverState *bs, AioContext *ctx,
+ BdrvChild *ignore_child, Error **errp);
+bool bdrv_child_can_set_aio_context(BdrvChild *c, AioContext *ctx,
+ GSList **ignore, Error **errp);
+bool bdrv_can_set_aio_context(BlockDriverState *bs, AioContext *ctx,
+ GSList **ignore, Error **errp);
+
+int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz);
+int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo);
+
+void bdrv_add_child(BlockDriverState *parent, BlockDriverState *child,
+ Error **errp);
+void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp);
+
+/**
+ *
+ * bdrv_register_buf/bdrv_unregister_buf:
+ *
+ * Register/unregister a buffer for I/O. For example, VFIO drivers are
+ * interested to know the memory areas that would later be used for I/O, so
+ * that they can prepare IOMMU mapping etc., to get better performance.
+ */
+void bdrv_register_buf(BlockDriverState *bs, void *host, size_t size);
+void bdrv_unregister_buf(BlockDriverState *bs, void *host);
+
+void bdrv_cancel_in_flight(BlockDriverState *bs);
+
+#endif /* BLOCK_GLOBAL_STATE_H */
diff --git a/include/block/block-io.h b/include/block/block-io.h
new file mode 100644
index 0000000000..e2789dd344
--- /dev/null
+++ b/include/block/block-io.h
@@ -0,0 +1,322 @@
+/*
+ * QEMU System Emulator block driver
+ *
+ * Copyright (c) 2003 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#ifndef BLOCK_IO_H
+#define BLOCK_IO_H
+
+#include "block-common.h"
+
+/*
+ * I/O API functions. These functions are thread-safe, and therefore
+ * can run in any thread as long as the thread has called
+ * aio_context_acquire/release().
+ */
+
+int bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset,
+ int64_t bytes, BdrvRequestFlags flags);
+int bdrv_pread(BdrvChild *child, int64_t offset, void *buf, int64_t bytes);
+int bdrv_pwrite(BdrvChild *child, int64_t offset, const void *buf,
+ int64_t bytes);
+int bdrv_pwrite_sync(BdrvChild *child, int64_t offset,
+ const void *buf, int64_t bytes);
+/*
+ * Efficiently zero a region of the disk image. Note that this is a regular
+ * I/O request like read or write and should have a reasonable size. This
+ * function is not suitable for zeroing the entire image in a single request
+ * because it may allocate memory for the entire region.
+ */
+int coroutine_fn bdrv_co_pwrite_zeroes(BdrvChild *child, int64_t offset,
+ int64_t bytes, BdrvRequestFlags flags);
+
+int coroutine_fn bdrv_co_truncate(BdrvChild *child, int64_t offset, bool exact,
+ PreallocMode prealloc, BdrvRequestFlags flags,
+ Error **errp);
+int generated_co_wrapper
+bdrv_truncate(BdrvChild *child, int64_t offset, bool exact,
+ PreallocMode prealloc, BdrvRequestFlags flags, Error **errp);
+
+int64_t bdrv_nb_sectors(BlockDriverState *bs);
+int64_t bdrv_getlength(BlockDriverState *bs);
+int64_t bdrv_get_allocated_file_size(BlockDriverState *bs);
+BlockMeasureInfo *bdrv_measure(BlockDriver *drv, QemuOpts *opts,
+ BlockDriverState *in_bs, Error **errp);
+void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr);
+int coroutine_fn bdrv_co_delete_file(BlockDriverState *bs, Error **errp);
+void coroutine_fn bdrv_co_delete_file_noerr(BlockDriverState *bs);
+
+
+int generated_co_wrapper bdrv_check(BlockDriverState *bs, BdrvCheckResult *res,
+ BdrvCheckMode fix);
+
+void bdrv_aio_cancel_async(BlockAIOCB *acb);
+
+/* sg packet commands */
+int bdrv_co_ioctl(BlockDriverState *bs, int req, void *buf);
+
+/* Invalidate any cached metadata used by image formats */
+int generated_co_wrapper bdrv_invalidate_cache(BlockDriverState *bs,
+ Error **errp);
+
+/* Ensure contents are flushed to disk. */
+int generated_co_wrapper bdrv_flush(BlockDriverState *bs);
+int coroutine_fn bdrv_co_flush(BlockDriverState *bs);
+void bdrv_drain(BlockDriverState *bs);
+void coroutine_fn bdrv_co_drain(BlockDriverState *bs);
+
+int generated_co_wrapper bdrv_pdiscard(BdrvChild *child, int64_t offset,
+ int64_t bytes);
+int bdrv_co_pdiscard(BdrvChild *child, int64_t offset, int64_t bytes);
+bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs);
+int bdrv_block_status(BlockDriverState *bs, int64_t offset,
+ int64_t bytes, int64_t *pnum, int64_t *map,
+ BlockDriverState **file);
+int bdrv_block_status_above(BlockDriverState *bs, BlockDriverState *base,
+ int64_t offset, int64_t bytes, int64_t *pnum,
+ int64_t *map, BlockDriverState **file);
+int bdrv_is_allocated(BlockDriverState *bs, int64_t offset, int64_t bytes,
+ int64_t *pnum);
+int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base,
+ bool include_base, int64_t offset, int64_t bytes,
+ int64_t *pnum);
+int coroutine_fn bdrv_co_is_zero_fast(BlockDriverState *bs, int64_t offset,
+ int64_t bytes);
+
+bool bdrv_is_read_only(BlockDriverState *bs);
+bool bdrv_is_writable(BlockDriverState *bs);
+bool bdrv_is_sg(BlockDriverState *bs);
+bool bdrv_is_inserted(BlockDriverState *bs);
+const char *bdrv_get_format_name(BlockDriverState *bs);
+
+bool bdrv_supports_compressed_writes(BlockDriverState *bs);
+const char *bdrv_get_node_name(const BlockDriverState *bs);
+const char *bdrv_get_device_name(const BlockDriverState *bs);
+const char *bdrv_get_device_or_node_name(const BlockDriverState *bs);
+int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi);
+ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs,
+ Error **errp);
+BlockStatsSpecific *bdrv_get_specific_stats(BlockDriverState *bs);
+void bdrv_round_to_clusters(BlockDriverState *bs,
+ int64_t offset, int64_t bytes,
+ int64_t *cluster_offset,
+ int64_t *cluster_bytes);
+
+void bdrv_get_backing_filename(BlockDriverState *bs,
+ char *filename, int filename_size);
+
+int generated_co_wrapper
+bdrv_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
+int generated_co_wrapper
+bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
+int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
+ int64_t pos, int size);
+
+int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
+ int64_t pos, int size);
+
+/*
+ * Returns the alignment in bytes that is required so that no bounce buffer
+ * is required throughout the stack
+ */
+size_t bdrv_min_mem_align(BlockDriverState *bs);
+/* Returns optimal alignment in bytes for bounce buffer */
+size_t bdrv_opt_mem_align(BlockDriverState *bs);
+void *qemu_blockalign(BlockDriverState *bs, size_t size);
+void *qemu_blockalign0(BlockDriverState *bs, size_t size);
+void *qemu_try_blockalign(BlockDriverState *bs, size_t size);
+void *qemu_try_blockalign0(BlockDriverState *bs, size_t size);
+bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov);
+
+void bdrv_enable_copy_on_read(BlockDriverState *bs);
+void bdrv_disable_copy_on_read(BlockDriverState *bs);
+
+void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event);
+
+#define BLKDBG_EVENT(child, evt) \
+ do { \
+ if (child) { \
+ bdrv_debug_event(child->bs, evt); \
+ } \
+ } while (0)
+
+/**
+ * bdrv_get_aio_context:
+ *
+ * Returns: the currently bound #AioContext
+ */
+AioContext *bdrv_get_aio_context(BlockDriverState *bs);
+/**
+ * Move the current coroutine to the AioContext of @bs and return the old
+ * AioContext of the coroutine. Increase bs->in_flight so that draining @bs
+ * will wait for the operation to proceed until the corresponding
+ * bdrv_co_leave().
+ *
+ * Consequently, you can't call drain inside a bdrv_co_enter/leave() section as
+ * this will deadlock.
+ */
+AioContext *coroutine_fn bdrv_co_enter(BlockDriverState *bs);
+
+/**
+ * Ends a section started by bdrv_co_enter(). Move the current coroutine back
+ * to old_ctx and decrease bs->in_flight again.
+ */
+void coroutine_fn bdrv_co_leave(BlockDriverState *bs, AioContext *old_ctx);
+
+/**
+ * Transfer control to @co in the aio context of @bs
+ */
+void bdrv_coroutine_enter(BlockDriverState *bs, Coroutine *co);
+
+AioContext *bdrv_child_get_parent_aio_context(BdrvChild *c);
+AioContext *child_of_bds_get_parent_aio_context(BdrvChild *c);
+
+void bdrv_io_plug(BlockDriverState *bs);
+void bdrv_io_unplug(BlockDriverState *bs);
+
+/**
+ * bdrv_parent_drained_begin_single:
+ *
+ * Begin a quiesced section for the parent of @c. If @poll is true, wait for
+ * any pending activity to cease.
+ */
+void bdrv_parent_drained_begin_single(BdrvChild *c, bool poll);
+
+/**
+ * bdrv_parent_drained_end_single:
+ *
+ * End a quiesced section for the parent of @c.
+ *
+ * This polls @bs's AioContext until all scheduled sub-drained_ends
+ * have settled, which may result in graph changes.
+ */
+void bdrv_parent_drained_end_single(BdrvChild *c);
+
+/**
+ * bdrv_drain_poll:
+ *
+ * Poll for pending requests in @bs, its parents (except for @ignore_parent),
+ * and if @recursive is true its children as well (used for subtree drain).
+ *
+ * If @ignore_bds_parents is true, parents that are BlockDriverStates must
+ * ignore the drain request because they will be drained separately (used for
+ * drain_all).
+ *
+ * This is part of bdrv_drained_begin.
+ */
+bool bdrv_drain_poll(BlockDriverState *bs, bool recursive,
+ BdrvChild *ignore_parent, bool ignore_bds_parents);
+
+/**
+ * bdrv_drained_begin:
+ *
+ * Begin a quiesced section for exclusive access to the BDS, by disabling
+ * external request sources including NBD server, block jobs, and device model.
+ *
+ * This function can be recursive.
+ */
+void bdrv_drained_begin(BlockDriverState *bs);
+
+/**
+ * bdrv_do_drained_begin_quiesce:
+ *
+ * Quiesces a BDS like bdrv_drained_begin(), but does not wait for already
+ * running requests to complete.
+ */
+void bdrv_do_drained_begin_quiesce(BlockDriverState *bs,
+ BdrvChild *parent, bool ignore_bds_parents);
+
+/**
+ * Like bdrv_drained_begin, but recursively begins a quiesced section for
+ * exclusive access to all child nodes as well.
+ */
+void bdrv_subtree_drained_begin(BlockDriverState *bs);
+
+/**
+ * bdrv_drained_end:
+ *
+ * End a quiescent section started by bdrv_drained_begin().
+ *
+ * This polls @bs's AioContext until all scheduled sub-drained_ends
+ * have settled. On one hand, that may result in graph changes. On
+ * the other, this requires that the caller either runs in the main
+ * loop; or that all involved nodes (@bs and all of its parents) are
+ * in the caller's AioContext.
+ */
+void bdrv_drained_end(BlockDriverState *bs);
+
+/**
+ * bdrv_drained_end_no_poll:
+ *
+ * Same as bdrv_drained_end(), but do not poll for the subgraph to
+ * actually become unquiesced. Therefore, no graph changes will occur
+ * with this function.
+ *
+ * *drained_end_counter is incremented for every background operation
+ * that is scheduled, and will be decremented for every operation once
+ * it settles. The caller must poll until it reaches 0. The counter
+ * should be accessed using atomic operations only.
+ */
+void bdrv_drained_end_no_poll(BlockDriverState *bs, int *drained_end_counter);
+
+/**
+ * End a quiescent section started by bdrv_subtree_drained_begin().
+ */
+void bdrv_subtree_drained_end(BlockDriverState *bs);
+
+bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name,
+ uint32_t granularity, Error **errp);
+
+/**
+ *
+ * bdrv_co_copy_range:
+ *
+ * Do offloaded copy between two children. If the operation is not implemented
+ * by the driver, or if the backend storage doesn't support it, a negative
+ * error code will be returned.
+ *
+ * Note: block layer doesn't emulate or fallback to a bounce buffer approach
+ * because usually the caller shouldn't attempt offloaded copy any more (e.g.
+ * calling copy_file_range(2)) after the first error, thus it should fall back
+ * to a read+write path in the caller level.
+ *
+ * @src: Source child to copy data from
+ * @src_offset: offset in @src image to read data
+ * @dst: Destination child to copy data to
+ * @dst_offset: offset in @dst image to write data
+ * @bytes: number of bytes to copy
+ * @flags: request flags. Supported flags:
+ * BDRV_REQ_ZERO_WRITE - treat the @src range as zero data and do zero
+ * write on @dst as if bdrv_co_pwrite_zeroes is
+ * called. Used to simplify caller code, or
+ * during BlockDriver.bdrv_co_copy_range_from()
+ * recursion.
+ * BDRV_REQ_NO_SERIALISING - do not serialize with other overlapping
+ * requests currently in flight.
+ *
+ * Returns: 0 if succeeded; negative error code if failed.
+ **/
+int coroutine_fn bdrv_co_copy_range(BdrvChild *src, int64_t src_offset,
+ BdrvChild *dst, int64_t dst_offset,
+ int64_t bytes, BdrvRequestFlags read_flags,
+ BdrvRequestFlags write_flags);
+
+#endif /* BLOCK_IO_H */
diff --git a/include/block/block.h b/include/block/block.h
index e5dd22b034..1e6b8fef1e 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -1,864 +1,32 @@
-#ifndef BLOCK_H
-#define BLOCK_H
-
-#include "block/aio.h"
-#include "block/aio-wait.h"
-#include "qemu/iov.h"
-#include "qemu/coroutine.h"
-#include "block/accounting.h"
-#include "block/dirty-bitmap.h"
-#include "block/blockjob.h"
-#include "qemu/hbitmap.h"
-#include "qemu/transactions.h"
-
/*
- * generated_co_wrapper
- *
- * Function specifier, which does nothing but mark functions to be
- * generated by scripts/block-coroutine-wrapper.py
- *
- * Read more in docs/devel/block-coroutine-wrapper.rst
- */
-#define generated_co_wrapper
-
-/* block.c */
-typedef struct BlockDriver BlockDriver;
-typedef struct BdrvChild BdrvChild;
-typedef struct BdrvChildClass BdrvChildClass;
-
-typedef struct BlockDriverInfo {
- /* in bytes, 0 if irrelevant */
- int cluster_size;
- /* offset at which the VM state can be saved (0 if not possible) */
- int64_t vm_state_offset;
- bool is_dirty;
- /*
- * True if this block driver only supports compressed writes
- */
- bool needs_compressed_writes;
-} BlockDriverInfo;
-
-typedef struct BlockFragInfo {
- uint64_t allocated_clusters;
- uint64_t total_clusters;
- uint64_t fragmented_clusters;
- uint64_t compressed_clusters;
-} BlockFragInfo;
-
-typedef enum {
- BDRV_REQ_COPY_ON_READ = 0x1,
- BDRV_REQ_ZERO_WRITE = 0x2,
-
- /*
- * The BDRV_REQ_MAY_UNMAP flag is used in write_zeroes requests to indicate
- * that the block driver should unmap (discard) blocks if it is guaranteed
- * that the result will read back as zeroes. The flag is only passed to the
- * driver if the block device is opened with BDRV_O_UNMAP.
- */
- BDRV_REQ_MAY_UNMAP = 0x4,
-
- BDRV_REQ_FUA = 0x10,
- BDRV_REQ_WRITE_COMPRESSED = 0x20,
-
- /* Signifies that this write request will not change the visible disk
- * content. */
- BDRV_REQ_WRITE_UNCHANGED = 0x40,
-
- /* Forces request serialisation. Use only with write requests. */
- BDRV_REQ_SERIALISING = 0x80,
-
- /* Execute the request only if the operation can be offloaded or otherwise
- * be executed efficiently, but return an error instead of using a slow
- * fallback. */
- BDRV_REQ_NO_FALLBACK = 0x100,
-
- /*
- * BDRV_REQ_PREFETCH makes sense only in the context of copy-on-read
- * (i.e., together with the BDRV_REQ_COPY_ON_READ flag or when a COR
- * filter is involved), in which case it signals that the COR operation
- * need not read the data into memory (qiov) but only ensure they are
- * copied to the top layer (i.e., that COR operation is done).
- */
- BDRV_REQ_PREFETCH = 0x200,
-
- /*
- * If we need to wait for other requests, just fail immediately. Used
- * only together with BDRV_REQ_SERIALISING.
- */
- BDRV_REQ_NO_WAIT = 0x400,
-
- /* Mask of valid flags */
- BDRV_REQ_MASK = 0x7ff,
-} BdrvRequestFlags;
-
-typedef struct BlockSizes {
- uint32_t phys;
- uint32_t log;
-} BlockSizes;
-
-typedef struct HDGeometry {
- uint32_t heads;
- uint32_t sectors;
- uint32_t cylinders;
-} HDGeometry;
-
-#define BDRV_O_NO_SHARE 0x0001 /* don't share permissions */
-#define BDRV_O_RDWR 0x0002
-#define BDRV_O_RESIZE 0x0004 /* request permission for resizing the node */
-#define BDRV_O_SNAPSHOT 0x0008 /* open the file read only and save writes in a snapshot */
-#define BDRV_O_TEMPORARY 0x0010 /* delete the file after use */
-#define BDRV_O_NOCACHE 0x0020 /* do not use the host page cache */
-#define BDRV_O_NATIVE_AIO 0x0080 /* use native AIO instead of the thread pool */
-#define BDRV_O_NO_BACKING 0x0100 /* don't open the backing file */
-#define BDRV_O_NO_FLUSH 0x0200 /* disable flushing on this disk */
-#define BDRV_O_COPY_ON_READ 0x0400 /* copy read backing sectors into image */
-#define BDRV_O_INACTIVE 0x0800 /* consistency hint for migration handoff */
-#define BDRV_O_CHECK 0x1000 /* open solely for consistency check */
-#define BDRV_O_ALLOW_RDWR 0x2000 /* allow reopen to change from r/o to r/w */
-#define BDRV_O_UNMAP 0x4000 /* execute guest UNMAP/TRIM operations */
-#define BDRV_O_PROTOCOL 0x8000 /* if no block driver is explicitly given:
- select an appropriate protocol driver,
- ignoring the format layer */
-#define BDRV_O_NO_IO 0x10000 /* don't initialize for I/O */
-#define BDRV_O_AUTO_RDONLY 0x20000 /* degrade to read-only if opening read-write fails */
-#define BDRV_O_IO_URING 0x40000 /* use io_uring instead of the thread pool */
-
-#define BDRV_O_CACHE_MASK (BDRV_O_NOCACHE | BDRV_O_NO_FLUSH)
-
-
-/* Option names of options parsed by the block layer */
-
-#define BDRV_OPT_CACHE_WB "cache.writeback"
-#define BDRV_OPT_CACHE_DIRECT "cache.direct"
-#define BDRV_OPT_CACHE_NO_FLUSH "cache.no-flush"
-#define BDRV_OPT_READ_ONLY "read-only"
-#define BDRV_OPT_AUTO_READ_ONLY "auto-read-only"
-#define BDRV_OPT_DISCARD "discard"
-#define BDRV_OPT_FORCE_SHARE "force-share"
-
-
-#define BDRV_SECTOR_BITS 9
-#define BDRV_SECTOR_SIZE (1ULL << BDRV_SECTOR_BITS)
-
-#define BDRV_REQUEST_MAX_SECTORS MIN_CONST(SIZE_MAX >> BDRV_SECTOR_BITS, \
- INT_MAX >> BDRV_SECTOR_BITS)
-#define BDRV_REQUEST_MAX_BYTES (BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS)
-
-/*
- * We want allow aligning requests and disk length up to any 32bit alignment
- * and don't afraid of overflow.
- * To achieve it, and in the same time use some pretty number as maximum disk
- * size, let's define maximum "length" (a limit for any offset/bytes request and
- * for disk size) to be the greatest power of 2 less than INT64_MAX.
- */
-#define BDRV_MAX_ALIGNMENT (1L << 30)
-#define BDRV_MAX_LENGTH (QEMU_ALIGN_DOWN(INT64_MAX, BDRV_MAX_ALIGNMENT))
-
-/*
- * Allocation status flags for bdrv_block_status() and friends.
- *
- * Public flags:
- * BDRV_BLOCK_DATA: allocation for data at offset is tied to this layer
- * BDRV_BLOCK_ZERO: offset reads as zero
- * BDRV_BLOCK_OFFSET_VALID: an associated offset exists for accessing raw data
- * BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
- * layer rather than any backing, set by block layer
- * BDRV_BLOCK_EOF: the returned pnum covers through end of file for this
- * layer, set by block layer
- *
- * Internal flags:
- * BDRV_BLOCK_RAW: for use by passthrough drivers, such as raw, to request
- * that the block layer recompute the answer from the returned
- * BDS; must be accompanied by just BDRV_BLOCK_OFFSET_VALID.
- * BDRV_BLOCK_RECURSE: request that the block layer will recursively search for
- * zeroes in file child of current block node inside
- * returned region. Only valid together with both
- * BDRV_BLOCK_DATA and BDRV_BLOCK_OFFSET_VALID. Should not
- * appear with BDRV_BLOCK_ZERO.
- *
- * If BDRV_BLOCK_OFFSET_VALID is set, the map parameter represents the
- * host offset within the returned BDS that is allocated for the
- * corresponding raw guest data. However, whether that offset
- * actually contains data also depends on BDRV_BLOCK_DATA, as follows:
- *
- * DATA ZERO OFFSET_VALID
- * t t t sectors read as zero, returned file is zero at offset
- * t f t sectors read as valid from file at offset
- * f t t sectors preallocated, read as zero, returned file not
- * necessarily zero at offset
- * f f t sectors preallocated but read from backing_hd,
- * returned file contains garbage at offset
- * t t f sectors preallocated, read as zero, unknown offset
- * t f f sectors read from unknown file or offset
- * f t f not allocated or unknown offset, read as zero
- * f f f not allocated or unknown offset, read from backing_hd
- */
-#define BDRV_BLOCK_DATA 0x01
-#define BDRV_BLOCK_ZERO 0x02
-#define BDRV_BLOCK_OFFSET_VALID 0x04
-#define BDRV_BLOCK_RAW 0x08
-#define BDRV_BLOCK_ALLOCATED 0x10
-#define BDRV_BLOCK_EOF 0x20
-#define BDRV_BLOCK_RECURSE 0x40
-
-typedef QTAILQ_HEAD(BlockReopenQueue, BlockReopenQueueEntry) BlockReopenQueue;
-
-typedef struct BDRVReopenState {
- BlockDriverState *bs;
- int flags;
- BlockdevDetectZeroesOptions detect_zeroes;
- bool backing_missing;
- BlockDriverState *old_backing_bs; /* keep pointer for permissions update */
- BlockDriverState *old_file_bs; /* keep pointer for permissions update */
- QDict *options;
- QDict *explicit_options;
- void *opaque;
-} BDRVReopenState;
-
-/*
- * Block operation types
- */
-typedef enum BlockOpType {
- BLOCK_OP_TYPE_BACKUP_SOURCE,
- BLOCK_OP_TYPE_BACKUP_TARGET,
- BLOCK_OP_TYPE_CHANGE,
- BLOCK_OP_TYPE_COMMIT_SOURCE,
- BLOCK_OP_TYPE_COMMIT_TARGET,
- BLOCK_OP_TYPE_DATAPLANE,
- BLOCK_OP_TYPE_DRIVE_DEL,
- BLOCK_OP_TYPE_EJECT,
- BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT,
- BLOCK_OP_TYPE_INTERNAL_SNAPSHOT,
- BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE,
- BLOCK_OP_TYPE_MIRROR_SOURCE,
- BLOCK_OP_TYPE_MIRROR_TARGET,
- BLOCK_OP_TYPE_RESIZE,
- BLOCK_OP_TYPE_STREAM,
- BLOCK_OP_TYPE_REPLACE,
- BLOCK_OP_TYPE_MAX,
-} BlockOpType;
-
-/* Block node permission constants */
-enum {
- /**
- * A user that has the "permission" of consistent reads is guaranteed that
- * their view of the contents of the block device is complete and
- * self-consistent, representing the contents of a disk at a specific
- * point.
- *
- * For most block devices (including their backing files) this is true, but
- * the property cannot be maintained in a few situations like for
- * intermediate nodes of a commit block job.
- */
- BLK_PERM_CONSISTENT_READ = 0x01,
-
- /** This permission is required to change the visible disk contents. */
- BLK_PERM_WRITE = 0x02,
-
- /**
- * This permission (which is weaker than BLK_PERM_WRITE) is both enough and
- * required for writes to the block node when the caller promises that
- * the visible disk content doesn't change.
- *
- * As the BLK_PERM_WRITE permission is strictly stronger, either is
- * sufficient to perform an unchanging write.
- */
- BLK_PERM_WRITE_UNCHANGED = 0x04,
-
- /** This permission is required to change the size of a block node. */
- BLK_PERM_RESIZE = 0x08,
-
- /**
- * This permission is required to change the node that this BdrvChild
- * points to.
- */
- BLK_PERM_GRAPH_MOD = 0x10,
-
- BLK_PERM_ALL = 0x1f,
-
- DEFAULT_PERM_PASSTHROUGH = BLK_PERM_CONSISTENT_READ
- | BLK_PERM_WRITE
- | BLK_PERM_WRITE_UNCHANGED
- | BLK_PERM_RESIZE,
-
- DEFAULT_PERM_UNCHANGED = BLK_PERM_ALL & ~DEFAULT_PERM_PASSTHROUGH,
-};
-
-/*
- * Flags that parent nodes assign to child nodes to specify what kind of
- * role(s) they take.
- *
- * At least one of DATA, METADATA, FILTERED, or COW must be set for
- * every child.
- */
-enum BdrvChildRoleBits {
- /*
- * This child stores data.
- * Any node may have an arbitrary number of such children.
- */
- BDRV_CHILD_DATA = (1 << 0),
-
- /*
- * This child stores metadata.
- * Any node may have an arbitrary number of metadata-storing
- * children.
- */
- BDRV_CHILD_METADATA = (1 << 1),
-
- /*
- * A child that always presents exactly the same visible data as
- * the parent, e.g. by virtue of the parent forwarding all reads
- * and writes.
- * This flag is mutually exclusive with DATA, METADATA, and COW.
- * Any node may have at most one filtered child at a time.
- */
- BDRV_CHILD_FILTERED = (1 << 2),
-
- /*
- * Child from which to read all data that isn't allocated in the
- * parent (i.e., the backing child); such data is copied to the
- * parent through COW (and optionally COR).
- * This field is mutually exclusive with DATA, METADATA, and
- * FILTERED.
- * Any node may have at most one such backing child at a time.
- */
- BDRV_CHILD_COW = (1 << 3),
-
- /*
- * The primary child. For most drivers, this is the child whose
- * filename applies best to the parent node.
- * Any node may have at most one primary child at a time.
- */
- BDRV_CHILD_PRIMARY = (1 << 4),
-
- /* Useful combination of flags */
- BDRV_CHILD_IMAGE = BDRV_CHILD_DATA
- | BDRV_CHILD_METADATA
- | BDRV_CHILD_PRIMARY,
-};
-
-/* Mask of BdrvChildRoleBits values */
-typedef unsigned int BdrvChildRole;
-
-char *bdrv_perm_names(uint64_t perm);
-uint64_t bdrv_qapi_perm_to_blk_perm(BlockPermission qapi_perm);
-
-/* disk I/O throttling */
-void bdrv_init(void);
-void bdrv_init_with_whitelist(void);
-bool bdrv_uses_whitelist(void);
-int bdrv_is_whitelisted(BlockDriver *drv, bool read_only);
-BlockDriver *bdrv_find_protocol(const char *filename,
- bool allow_protocol_prefix,
- Error **errp);
-BlockDriver *bdrv_find_format(const char *format_name);
-int bdrv_create(BlockDriver *drv, const char* filename,
- QemuOpts *opts, Error **errp);
-int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp);
-
-BlockDriverState *bdrv_new(void);
-int bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
- Error **errp);
-int bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
- Error **errp);
-int bdrv_replace_child_bs(BdrvChild *child, BlockDriverState *new_bs,
- Error **errp);
-BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *node_options,
- int flags, Error **errp);
-int bdrv_drop_filter(BlockDriverState *bs, Error **errp);
-
-int bdrv_parse_aio(const char *mode, int *flags);
-int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough);
-int bdrv_parse_discard_flags(const char *mode, int *flags);
-BdrvChild *bdrv_open_child(const char *filename,
- QDict *options, const char *bdref_key,
- BlockDriverState* parent,
- const BdrvChildClass *child_class,
- BdrvChildRole child_role,
- bool allow_none, Error **errp);
-BlockDriverState *bdrv_open_blockdev_ref(BlockdevRef *ref, Error **errp);
-int bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
- Error **errp);
-int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
- const char *bdref_key, Error **errp);
-BlockDriverState *bdrv_open(const char *filename, const char *reference,
- QDict *options, int flags, Error **errp);
-BlockDriverState *bdrv_new_open_driver_opts(BlockDriver *drv,
- const char *node_name,
- QDict *options, int flags,
- Error **errp);
-BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name,
- int flags, Error **errp);
-BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
- BlockDriverState *bs, QDict *options,
- bool keep_old_opts);
-void bdrv_reopen_queue_free(BlockReopenQueue *bs_queue);
-int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp);
-int bdrv_reopen(BlockDriverState *bs, QDict *opts, bool keep_old_opts,
- Error **errp);
-int bdrv_reopen_set_read_only(BlockDriverState *bs, bool read_only,
- Error **errp);
-int bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset,
- int64_t bytes, BdrvRequestFlags flags);
-int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags);
-int bdrv_pread(BdrvChild *child, int64_t offset, void *buf, int64_t bytes);
-int bdrv_pwrite(BdrvChild *child, int64_t offset, const void *buf,
- int64_t bytes);
-int bdrv_pwrite_sync(BdrvChild *child, int64_t offset,
- const void *buf, int64_t bytes);
-/*
- * Efficiently zero a region of the disk image. Note that this is a regular
- * I/O request like read or write and should have a reasonable size. This
- * function is not suitable for zeroing the entire image in a single request
- * because it may allocate memory for the entire region.
- */
-int coroutine_fn bdrv_co_pwrite_zeroes(BdrvChild *child, int64_t offset,
- int64_t bytes, BdrvRequestFlags flags);
-BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
- const char *backing_file);
-void bdrv_refresh_filename(BlockDriverState *bs);
-
-int coroutine_fn bdrv_co_truncate(BdrvChild *child, int64_t offset, bool exact,
- PreallocMode prealloc, BdrvRequestFlags flags,
- Error **errp);
-int generated_co_wrapper
-bdrv_truncate(BdrvChild *child, int64_t offset, bool exact,
- PreallocMode prealloc, BdrvRequestFlags flags, Error **errp);
-
-int64_t bdrv_nb_sectors(BlockDriverState *bs);
-int64_t bdrv_getlength(BlockDriverState *bs);
-int64_t bdrv_get_allocated_file_size(BlockDriverState *bs);
-BlockMeasureInfo *bdrv_measure(BlockDriver *drv, QemuOpts *opts,
- BlockDriverState *in_bs, Error **errp);
-void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr);
-void bdrv_refresh_limits(BlockDriverState *bs, Transaction *tran, Error **errp);
-int bdrv_commit(BlockDriverState *bs);
-int bdrv_make_empty(BdrvChild *c, Error **errp);
-int bdrv_change_backing_file(BlockDriverState *bs, const char *backing_file,
- const char *backing_fmt, bool warn);
-void bdrv_register(BlockDriver *bdrv);
-int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base,
- const char *backing_file_str);
-BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
- BlockDriverState *bs);
-BlockDriverState *bdrv_find_base(BlockDriverState *bs);
-bool bdrv_is_backing_chain_frozen(BlockDriverState *bs, BlockDriverState *base,
- Error **errp);
-int bdrv_freeze_backing_chain(BlockDriverState *bs, BlockDriverState *base,
- Error **errp);
-void bdrv_unfreeze_backing_chain(BlockDriverState *bs, BlockDriverState *base);
-int coroutine_fn bdrv_co_delete_file(BlockDriverState *bs, Error **errp);
-void coroutine_fn bdrv_co_delete_file_noerr(BlockDriverState *bs);
-
-
-typedef struct BdrvCheckResult {
- int corruptions;
- int leaks;
- int check_errors;
- int corruptions_fixed;
- int leaks_fixed;
- int64_t image_end_offset;
- BlockFragInfo bfi;
-} BdrvCheckResult;
-
-typedef enum {
- BDRV_FIX_LEAKS = 1,
- BDRV_FIX_ERRORS = 2,
-} BdrvCheckMode;
-
-int generated_co_wrapper bdrv_check(BlockDriverState *bs, BdrvCheckResult *res,
- BdrvCheckMode fix);
-
-/* The units of offset and total_work_size may be chosen arbitrarily by the
- * block driver; total_work_size may change during the course of the amendment
- * operation */
-typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset,
- int64_t total_work_size, void *opaque);
-int bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts,
- BlockDriverAmendStatusCB *status_cb, void *cb_opaque,
- bool force,
- Error **errp);
-
-/* check if a named node can be replaced when doing drive-mirror */
-BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
- const char *node_name, Error **errp);
-
-/* async block I/O */
-void bdrv_aio_cancel(BlockAIOCB *acb);
-void bdrv_aio_cancel_async(BlockAIOCB *acb);
-
-/* sg packet commands */
-int bdrv_co_ioctl(BlockDriverState *bs, int req, void *buf);
-
-/* Invalidate any cached metadata used by image formats */
-int generated_co_wrapper bdrv_invalidate_cache(BlockDriverState *bs,
- Error **errp);
-void bdrv_invalidate_cache_all(Error **errp);
-int bdrv_inactivate_all(void);
-
-/* Ensure contents are flushed to disk. */
-int generated_co_wrapper bdrv_flush(BlockDriverState *bs);
-int coroutine_fn bdrv_co_flush(BlockDriverState *bs);
-int bdrv_flush_all(void);
-void bdrv_close_all(void);
-void bdrv_drain(BlockDriverState *bs);
-void coroutine_fn bdrv_co_drain(BlockDriverState *bs);
-void bdrv_drain_all_begin(void);
-void bdrv_drain_all_end(void);
-void bdrv_drain_all(void);
-
-#define BDRV_POLL_WHILE(bs, cond) ({ \
- BlockDriverState *bs_ = (bs); \
- AIO_WAIT_WHILE(bdrv_get_aio_context(bs_), \
- cond); })
-
-int generated_co_wrapper bdrv_pdiscard(BdrvChild *child, int64_t offset,
- int64_t bytes);
-int bdrv_co_pdiscard(BdrvChild *child, int64_t offset, int64_t bytes);
-int bdrv_has_zero_init_1(BlockDriverState *bs);
-int bdrv_has_zero_init(BlockDriverState *bs);
-bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs);
-int bdrv_block_status(BlockDriverState *bs, int64_t offset,
- int64_t bytes, int64_t *pnum, int64_t *map,
- BlockDriverState **file);
-int bdrv_block_status_above(BlockDriverState *bs, BlockDriverState *base,
- int64_t offset, int64_t bytes, int64_t *pnum,
- int64_t *map, BlockDriverState **file);
-int bdrv_is_allocated(BlockDriverState *bs, int64_t offset, int64_t bytes,
- int64_t *pnum);
-int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base,
- bool include_base, int64_t offset, int64_t bytes,
- int64_t *pnum);
-int coroutine_fn bdrv_co_is_zero_fast(BlockDriverState *bs, int64_t offset,
- int64_t bytes);
-
-bool bdrv_is_read_only(BlockDriverState *bs);
-int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only,
- bool ignore_allow_rdw, Error **errp);
-int bdrv_apply_auto_read_only(BlockDriverState *bs, const char *errmsg,
- Error **errp);
-bool bdrv_is_writable(BlockDriverState *bs);
-bool bdrv_is_sg(BlockDriverState *bs);
-bool bdrv_is_inserted(BlockDriverState *bs);
-void bdrv_lock_medium(BlockDriverState *bs, bool locked);
-void bdrv_eject(BlockDriverState *bs, bool eject_flag);
-const char *bdrv_get_format_name(BlockDriverState *bs);
-BlockDriverState *bdrv_find_node(const char *node_name);
-BlockDeviceInfoList *bdrv_named_nodes_list(bool flat, Error **errp);
-XDbgBlockGraph *bdrv_get_xdbg_block_graph(Error **errp);
-BlockDriverState *bdrv_lookup_bs(const char *device,
- const char *node_name,
- Error **errp);
-bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base);
-BlockDriverState *bdrv_next_node(BlockDriverState *bs);
-BlockDriverState *bdrv_next_all_states(BlockDriverState *bs);
-
-typedef struct BdrvNextIterator {
- enum {
- BDRV_NEXT_BACKEND_ROOTS,
- BDRV_NEXT_MONITOR_OWNED,
- } phase;
- BlockBackend *blk;
- BlockDriverState *bs;
-} BdrvNextIterator;
-
-BlockDriverState *bdrv_first(BdrvNextIterator *it);
-BlockDriverState *bdrv_next(BdrvNextIterator *it);
-void bdrv_next_cleanup(BdrvNextIterator *it);
-
-BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs);
-bool bdrv_supports_compressed_writes(BlockDriverState *bs);
-void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
- void *opaque, bool read_only);
-const char *bdrv_get_node_name(const BlockDriverState *bs);
-const char *bdrv_get_device_name(const BlockDriverState *bs);
-const char *bdrv_get_device_or_node_name(const BlockDriverState *bs);
-int bdrv_get_flags(BlockDriverState *bs);
-int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi);
-ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs,
- Error **errp);
-BlockStatsSpecific *bdrv_get_specific_stats(BlockDriverState *bs);
-void bdrv_round_to_clusters(BlockDriverState *bs,
- int64_t offset, int64_t bytes,
- int64_t *cluster_offset,
- int64_t *cluster_bytes);
-
-void bdrv_get_backing_filename(BlockDriverState *bs,
- char *filename, int filename_size);
-char *bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp);
-char *bdrv_get_full_backing_filename_from_filename(const char *backed,
- const char *backing,
- Error **errp);
-char *bdrv_dirname(BlockDriverState *bs, Error **errp);
-
-int path_has_protocol(const char *path);
-int path_is_absolute(const char *path);
-char *path_combine(const char *base_path, const char *filename);
-
-int generated_co_wrapper
-bdrv_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
-int generated_co_wrapper
-bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
-int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
- int64_t pos, int size);
-
-int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
- int64_t pos, int size);
-
-void bdrv_img_create(const char *filename, const char *fmt,
- const char *base_filename, const char *base_fmt,
- char *options, uint64_t img_size, int flags,
- bool quiet, Error **errp);
-
-/* Returns the alignment in bytes that is required so that no bounce buffer
- * is required throughout the stack */
-size_t bdrv_min_mem_align(BlockDriverState *bs);
-/* Returns optimal alignment in bytes for bounce buffer */
-size_t bdrv_opt_mem_align(BlockDriverState *bs);
-void *qemu_blockalign(BlockDriverState *bs, size_t size);
-void *qemu_blockalign0(BlockDriverState *bs, size_t size);
-void *qemu_try_blockalign(BlockDriverState *bs, size_t size);
-void *qemu_try_blockalign0(BlockDriverState *bs, size_t size);
-bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov);
-
-void bdrv_enable_copy_on_read(BlockDriverState *bs);
-void bdrv_disable_copy_on_read(BlockDriverState *bs);
-
-void bdrv_ref(BlockDriverState *bs);
-void bdrv_unref(BlockDriverState *bs);
-void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child);
-BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
- BlockDriverState *child_bs,
- const char *child_name,
- const BdrvChildClass *child_class,
- BdrvChildRole child_role,
- Error **errp);
-
-bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp);
-void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);
-void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason);
-void bdrv_op_block_all(BlockDriverState *bs, Error *reason);
-void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason);
-bool bdrv_op_blocker_is_empty(BlockDriverState *bs);
-
-#define BLKDBG_EVENT(child, evt) \
- do { \
- if (child) { \
- bdrv_debug_event(child->bs, evt); \
- } \
- } while (0)
-
-void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event);
-
-int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
- const char *tag);
-int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag);
-int bdrv_debug_resume(BlockDriverState *bs, const char *tag);
-bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag);
-
-/**
- * bdrv_get_aio_context:
+ * QEMU System Emulator block driver
*
- * Returns: the currently bound #AioContext
- */
-AioContext *bdrv_get_aio_context(BlockDriverState *bs);
-
-/**
- * Move the current coroutine to the AioContext of @bs and return the old
- * AioContext of the coroutine. Increase bs->in_flight so that draining @bs
- * will wait for the operation to proceed until the corresponding
- * bdrv_co_leave().
+ * Copyright (c) 2003 Fabrice Bellard
*
- * Consequently, you can't call drain inside a bdrv_co_enter/leave() section as
- * this will deadlock.
- */
-AioContext *coroutine_fn bdrv_co_enter(BlockDriverState *bs);
-
-/**
- * Ends a section started by bdrv_co_enter(). Move the current coroutine back
- * to old_ctx and decrease bs->in_flight again.
- */
-void coroutine_fn bdrv_co_leave(BlockDriverState *bs, AioContext *old_ctx);
-
-/**
- * Locks the AioContext of @bs if it's not the current AioContext. This avoids
- * double locking which could lead to deadlocks: This is a coroutine_fn, so we
- * know we already own the lock of the current AioContext.
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
*
- * May only be called in the main thread.
- */
-void coroutine_fn bdrv_co_lock(BlockDriverState *bs);
-
-/**
- * Unlocks the AioContext of @bs if it's not the current AioContext.
- */
-void coroutine_fn bdrv_co_unlock(BlockDriverState *bs);
-
-/**
- * Transfer control to @co in the aio context of @bs
- */
-void bdrv_coroutine_enter(BlockDriverState *bs, Coroutine *co);
-
-void bdrv_set_aio_context_ignore(BlockDriverState *bs,
- AioContext *new_context, GSList **ignore);
-int bdrv_try_set_aio_context(BlockDriverState *bs, AioContext *ctx,
- Error **errp);
-int bdrv_child_try_set_aio_context(BlockDriverState *bs, AioContext *ctx,
- BdrvChild *ignore_child, Error **errp);
-bool bdrv_child_can_set_aio_context(BdrvChild *c, AioContext *ctx,
- GSList **ignore, Error **errp);
-bool bdrv_can_set_aio_context(BlockDriverState *bs, AioContext *ctx,
- GSList **ignore, Error **errp);
-AioContext *bdrv_child_get_parent_aio_context(BdrvChild *c);
-AioContext *child_of_bds_get_parent_aio_context(BdrvChild *c);
-
-int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz);
-int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo);
-
-void bdrv_io_plug(BlockDriverState *bs);
-void bdrv_io_unplug(BlockDriverState *bs);
-
-/**
- * bdrv_parent_drained_begin_single:
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
*
- * Begin a quiesced section for the parent of @c. If @poll is true, wait for
- * any pending activity to cease.
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
*/
-void bdrv_parent_drained_begin_single(BdrvChild *c, bool poll);
-
-/**
- * bdrv_parent_drained_end_single:
- *
- * End a quiesced section for the parent of @c.
- *
- * This polls @bs's AioContext until all scheduled sub-drained_ends
- * have settled, which may result in graph changes.
- */
-void bdrv_parent_drained_end_single(BdrvChild *c);
-
-/**
- * bdrv_drain_poll:
- *
- * Poll for pending requests in @bs, its parents (except for @ignore_parent),
- * and if @recursive is true its children as well (used for subtree drain).
- *
- * If @ignore_bds_parents is true, parents that are BlockDriverStates must
- * ignore the drain request because they will be drained separately (used for
- * drain_all).
- *
- * This is part of bdrv_drained_begin.
- */
-bool bdrv_drain_poll(BlockDriverState *bs, bool recursive,
- BdrvChild *ignore_parent, bool ignore_bds_parents);
-
-/**
- * bdrv_drained_begin:
- *
- * Begin a quiesced section for exclusive access to the BDS, by disabling
- * external request sources including NBD server, block jobs, and device model.
- *
- * This function can be recursive.
- */
-void bdrv_drained_begin(BlockDriverState *bs);
-
-/**
- * bdrv_do_drained_begin_quiesce:
- *
- * Quiesces a BDS like bdrv_drained_begin(), but does not wait for already
- * running requests to complete.
- */
-void bdrv_do_drained_begin_quiesce(BlockDriverState *bs,
- BdrvChild *parent, bool ignore_bds_parents);
-
-/**
- * Like bdrv_drained_begin, but recursively begins a quiesced section for
- * exclusive access to all child nodes as well.
- */
-void bdrv_subtree_drained_begin(BlockDriverState *bs);
-
-/**
- * bdrv_drained_end:
- *
- * End a quiescent section started by bdrv_drained_begin().
- *
- * This polls @bs's AioContext until all scheduled sub-drained_ends
- * have settled. On one hand, that may result in graph changes. On
- * the other, this requires that the caller either runs in the main
- * loop; or that all involved nodes (@bs and all of its parents) are
- * in the caller's AioContext.
- */
-void bdrv_drained_end(BlockDriverState *bs);
-
-/**
- * bdrv_drained_end_no_poll:
- *
- * Same as bdrv_drained_end(), but do not poll for the subgraph to
- * actually become unquiesced. Therefore, no graph changes will occur
- * with this function.
- *
- * *drained_end_counter is incremented for every background operation
- * that is scheduled, and will be decremented for every operation once
- * it settles. The caller must poll until it reaches 0. The counter
- * should be accessed using atomic operations only.
- */
-void bdrv_drained_end_no_poll(BlockDriverState *bs, int *drained_end_counter);
-
-/**
- * End a quiescent section started by bdrv_subtree_drained_begin().
- */
-void bdrv_subtree_drained_end(BlockDriverState *bs);
-
-void bdrv_add_child(BlockDriverState *parent, BlockDriverState *child,
- Error **errp);
-void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp);
-
-bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name,
- uint32_t granularity, Error **errp);
-/**
- *
- * bdrv_register_buf/bdrv_unregister_buf:
- *
- * Register/unregister a buffer for I/O. For example, VFIO drivers are
- * interested to know the memory areas that would later be used for I/O, so
- * that they can prepare IOMMU mapping etc., to get better performance.
- */
-void bdrv_register_buf(BlockDriverState *bs, void *host, size_t size);
-void bdrv_unregister_buf(BlockDriverState *bs, void *host);
+#ifndef BLOCK_H
+#define BLOCK_H
-/**
- *
- * bdrv_co_copy_range:
- *
- * Do offloaded copy between two children. If the operation is not implemented
- * by the driver, or if the backend storage doesn't support it, a negative
- * error code will be returned.
- *
- * Note: block layer doesn't emulate or fallback to a bounce buffer approach
- * because usually the caller shouldn't attempt offloaded copy any more (e.g.
- * calling copy_file_range(2)) after the first error, thus it should fall back
- * to a read+write path in the caller level.
- *
- * @src: Source child to copy data from
- * @src_offset: offset in @src image to read data
- * @dst: Destination child to copy data to
- * @dst_offset: offset in @dst image to write data
- * @bytes: number of bytes to copy
- * @flags: request flags. Supported flags:
- * BDRV_REQ_ZERO_WRITE - treat the @src range as zero data and do zero
- * write on @dst as if bdrv_co_pwrite_zeroes is
- * called. Used to simplify caller code, or
- * during BlockDriver.bdrv_co_copy_range_from()
- * recursion.
- * BDRV_REQ_NO_SERIALISING - do not serialize with other overlapping
- * requests currently in flight.
- *
- * Returns: 0 if succeeded; negative error code if failed.
- **/
-int coroutine_fn bdrv_co_copy_range(BdrvChild *src, int64_t src_offset,
- BdrvChild *dst, int64_t dst_offset,
- int64_t bytes, BdrvRequestFlags read_flags,
- BdrvRequestFlags write_flags);
+#include "block-global-state.h"
+#include "block-io.h"
-void bdrv_cancel_in_flight(BlockDriverState *bs);
+/* DO NOT ADD ANYTHING IN HERE. USE ONE OF THE HEADERS INCLUDED ABOVE */
-#endif
+#endif /* BLOCK_H */
diff --git a/block.c b/block.c
index 10346b5011..84de6867e6 100644
--- a/block.c
+++ b/block.c
@@ -67,12 +67,15 @@
#define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */
+/* Protected by BQL */
static QTAILQ_HEAD(, BlockDriverState) graph_bdrv_states =
QTAILQ_HEAD_INITIALIZER(graph_bdrv_states);
+/* Protected by BQL */
static QTAILQ_HEAD(, BlockDriverState) all_bdrv_states =
QTAILQ_HEAD_INITIALIZER(all_bdrv_states);
+/* Protected by BQL */
static QLIST_HEAD(, BlockDriver) bdrv_drivers =
QLIST_HEAD_INITIALIZER(bdrv_drivers);
diff --git a/block/meson.build b/block/meson.build
index deb73ca389..ee636e2754 100644
--- a/block/meson.build
+++ b/block/meson.build
@@ -113,8 +113,11 @@ block_ss.add(module_block_h)
wrapper_py = find_program('../scripts/block-coroutine-wrapper.py')
block_gen_c = custom_target('block-gen.c',
output: 'block-gen.c',
- input: files('../include/block/block.h',
- 'coroutines.h'),
+ input: files(
+ '../include/block/block-io.h',
+ '../include/block/block-global-state.h',
+ 'coroutines.h'
+ ),
command: [wrapper_py, '@OUTPUT@', '@INPUT@'])
block_ss.add(block_gen_c)
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 03/31] assertions for block global state API
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
2021-11-24 6:43 ` [PATCH v5 01/31] main-loop.h: introduce qemu_in_main_thread() Emanuele Giuseppe Esposito
2021-11-24 6:43 ` [PATCH v5 02/31] include/block/block: split header into I/O and global state API Emanuele Giuseppe Esposito
@ 2021-11-24 6:43 ` Emanuele Giuseppe Esposito
2021-12-16 15:17 ` Hanna Reitz
2021-11-24 6:43 ` [PATCH v5 04/31] include/sysemu/block-backend: split header into I/O and global state (GS) API Emanuele Giuseppe Esposito
` (28 subsequent siblings)
31 siblings, 1 reply; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:43 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
All the global state (GS) API functions will check that
qemu_in_main_thread() returns true. If not, it means
that the safety of BQL cannot be guaranteed, and
they need to be moved to I/O.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
block.c | 135 ++++++++++++++++++++++++++++++++++++++++++++++++-
block/commit.c | 2 +
block/io.c | 14 +++++
blockdev.c | 1 +
4 files changed, 150 insertions(+), 2 deletions(-)
diff --git a/block.c b/block.c
index 84de6867e6..49bee69e27 100644
--- a/block.c
+++ b/block.c
@@ -278,6 +278,8 @@ bool bdrv_is_read_only(BlockDriverState *bs)
int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only,
bool ignore_allow_rdw, Error **errp)
{
+ assert(qemu_in_main_thread());
+
/* Do not set read_only if copy_on_read is enabled */
if (bs->copy_on_read && read_only) {
error_setg(errp, "Can't set node '%s' to r/o with copy-on-read enabled",
@@ -311,6 +313,7 @@ int bdrv_apply_auto_read_only(BlockDriverState *bs, const char *errmsg,
Error **errp)
{
int ret = 0;
+ assert(qemu_in_main_thread());
if (!(bs->open_flags & BDRV_O_RDWR)) {
return 0;
@@ -393,6 +396,7 @@ char *bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp)
void bdrv_register(BlockDriver *bdrv)
{
assert(bdrv->format_name);
+ assert(qemu_in_main_thread());
QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list);
}
@@ -401,6 +405,8 @@ BlockDriverState *bdrv_new(void)
BlockDriverState *bs;
int i;
+ assert(qemu_in_main_thread());
+
bs = g_new0(BlockDriverState, 1);
QLIST_INIT(&bs->dirty_bitmaps);
for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
@@ -443,6 +449,8 @@ BlockDriver *bdrv_find_format(const char *format_name)
BlockDriver *drv1;
int i;
+ assert(qemu_in_main_thread());
+
drv1 = bdrv_do_find_format(format_name);
if (drv1) {
return drv1;
@@ -492,11 +500,13 @@ static int bdrv_format_is_whitelisted(const char *format_name, bool read_only)
int bdrv_is_whitelisted(BlockDriver *drv, bool read_only)
{
+ assert(qemu_in_main_thread());
return bdrv_format_is_whitelisted(drv->format_name, read_only);
}
bool bdrv_uses_whitelist(void)
{
+ assert(qemu_in_main_thread());
return use_bdrv_whitelist;
}
@@ -527,6 +537,8 @@ int bdrv_create(BlockDriver *drv, const char* filename,
{
int ret;
+ assert(qemu_in_main_thread());
+
Coroutine *co;
CreateCo cco = {
.drv = drv,
@@ -702,6 +714,8 @@ int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp)
QDict *qdict;
int ret;
+ assert(qemu_in_main_thread());
+
drv = bdrv_find_protocol(filename, true, errp);
if (drv == NULL) {
return -ENOENT;
@@ -799,6 +813,7 @@ int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz)
{
BlockDriver *drv = bs->drv;
BlockDriverState *filtered = bdrv_filter_bs(bs);
+ assert(qemu_in_main_thread());
if (drv && drv->bdrv_probe_blocksizes) {
return drv->bdrv_probe_blocksizes(bs, bsz);
@@ -819,6 +834,7 @@ int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo)
{
BlockDriver *drv = bs->drv;
BlockDriverState *filtered = bdrv_filter_bs(bs);
+ assert(qemu_in_main_thread());
if (drv && drv->bdrv_probe_geometry) {
return drv->bdrv_probe_geometry(bs, geo);
@@ -910,6 +926,7 @@ BlockDriver *bdrv_find_protocol(const char *filename,
const char *p;
int i;
+ assert(qemu_in_main_thread());
/* TODO Drivers without bdrv_file_open must be specified explicitly */
/*
@@ -975,6 +992,7 @@ BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
{
int score_max = 0, score;
BlockDriver *drv = NULL, *d;
+ assert(qemu_in_main_thread());
QLIST_FOREACH(d, &bdrv_drivers, list) {
if (d->bdrv_probe) {
@@ -1122,6 +1140,7 @@ int bdrv_parse_aio(const char *mode, int *flags)
*/
int bdrv_parse_discard_flags(const char *mode, int *flags)
{
+ assert(qemu_in_main_thread());
*flags &= ~BDRV_O_UNMAP;
if (!strcmp(mode, "off") || !strcmp(mode, "ignore")) {
@@ -1142,6 +1161,7 @@ int bdrv_parse_discard_flags(const char *mode, int *flags)
*/
int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough)
{
+ assert(qemu_in_main_thread());
*flags &= ~BDRV_O_CACHE_MASK;
if (!strcmp(mode, "off") || !strcmp(mode, "none")) {
@@ -1634,6 +1654,8 @@ BlockDriverState *bdrv_new_open_driver_opts(BlockDriver *drv,
BlockDriverState *bs;
int ret;
+ assert(qemu_in_main_thread());
+
bs = bdrv_new();
bs->open_flags = flags;
bs->options = options ?: qdict_new();
@@ -1659,6 +1681,7 @@ BlockDriverState *bdrv_new_open_driver_opts(BlockDriver *drv,
BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name,
int flags, Error **errp)
{
+ assert(qemu_in_main_thread());
return bdrv_new_open_driver_opts(drv, node_name, NULL, flags, errp);
}
@@ -2480,6 +2503,8 @@ void bdrv_get_cumulative_perm(BlockDriverState *bs, uint64_t *perm,
char *bdrv_perm_names(uint64_t perm)
{
+ assert(qemu_in_main_thread());
+
struct perm_name {
uint64_t perm;
const char *name;
@@ -2718,6 +2743,8 @@ void bdrv_default_perms(BlockDriverState *bs, BdrvChild *c,
uint64_t bdrv_qapi_perm_to_blk_perm(BlockPermission qapi_perm)
{
+ assert(qemu_in_main_thread());
+
static const uint64_t permissions[] = {
[BLOCK_PERMISSION_CONSISTENT_READ] = BLK_PERM_CONSISTENT_READ,
[BLOCK_PERMISSION_WRITE] = BLK_PERM_WRITE,
@@ -3097,6 +3124,8 @@ BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
BdrvChild *child = NULL;
Transaction *tran = tran_new();
+ assert(qemu_in_main_thread());
+
ret = bdrv_attach_child_noperm(parent_bs, child_bs, child_name, child_class,
child_role, &child, tran, errp);
if (ret < 0) {
@@ -3123,6 +3152,8 @@ void bdrv_root_unref_child(BdrvChild *child)
{
BlockDriverState *child_bs;
+ assert(qemu_in_main_thread());
+
child_bs = child->bs;
bdrv_detach_child(&child);
bdrv_unref(child_bs);
@@ -3197,6 +3228,7 @@ static void bdrv_unset_inherits_from(BlockDriverState *root, BdrvChild *child,
/* Callers must ensure that child->frozen is false. */
void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child)
{
+ assert(qemu_in_main_thread());
if (child == NULL) {
return;
}
@@ -3347,6 +3379,8 @@ int bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
int ret;
Transaction *tran = tran_new();
+ assert(qemu_in_main_thread());
+
ret = bdrv_set_backing_noperm(bs, backing_hd, tran, errp);
if (ret < 0) {
goto out;
@@ -3382,6 +3416,8 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
QDict *tmp_parent_options = NULL;
Error *local_err = NULL;
+ assert(qemu_in_main_thread());
+
if (bs->backing != NULL) {
goto free_exit;
}
@@ -3541,6 +3577,8 @@ BdrvChild *bdrv_open_child(const char *filename,
{
BlockDriverState *bs;
+ assert(qemu_in_main_thread());
+
bs = bdrv_open_child_bs(filename, options, bdref_key, parent, child_class,
child_role, allow_none, errp);
if (bs == NULL) {
@@ -3563,6 +3601,8 @@ BlockDriverState *bdrv_open_blockdev_ref(BlockdevRef *ref, Error **errp)
const char *reference = NULL;
Visitor *v = NULL;
+ assert(qemu_in_main_thread());
+
if (ref->type == QTYPE_QSTRING) {
reference = ref->u.reference;
} else {
@@ -3960,6 +4000,8 @@ close_and_fail:
BlockDriverState *bdrv_open(const char *filename, const char *reference,
QDict *options, int flags, Error **errp)
{
+ assert(qemu_in_main_thread());
+
return bdrv_open_inherit(filename, reference, options, flags, NULL,
NULL, 0, errp);
}
@@ -4214,12 +4256,15 @@ BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
BlockDriverState *bs,
QDict *options, bool keep_old_opts)
{
+ assert(qemu_in_main_thread());
+
return bdrv_reopen_queue_child(bs_queue, bs, options, NULL, 0, false,
NULL, 0, keep_old_opts);
}
void bdrv_reopen_queue_free(BlockReopenQueue *bs_queue)
{
+ assert(qemu_in_main_thread());
if (bs_queue) {
BlockReopenQueueEntry *bs_entry, *next;
QTAILQ_FOREACH_SAFE(bs_entry, bs_queue, entry, next) {
@@ -4367,6 +4412,8 @@ int bdrv_reopen(BlockDriverState *bs, QDict *opts, bool keep_old_opts,
BlockReopenQueue *queue;
int ret;
+ assert(qemu_in_main_thread());
+
bdrv_subtree_drained_begin(bs);
if (ctx != qemu_get_aio_context()) {
aio_context_release(ctx);
@@ -4388,6 +4435,8 @@ int bdrv_reopen_set_read_only(BlockDriverState *bs, bool read_only,
{
QDict *opts = qdict_new();
+ assert(qemu_in_main_thread());
+
qdict_put_bool(opts, BDRV_OPT_READ_ONLY, read_only);
return bdrv_reopen(bs, opts, true, errp);
@@ -4842,6 +4891,7 @@ static void bdrv_close(BlockDriverState *bs)
void bdrv_close_all(void)
{
assert(job_next(NULL) == NULL);
+ assert(qemu_in_main_thread());
/* Drop references from requests still in flight, such as canceled block
* jobs whose AIO context has not been polled yet */
@@ -5156,11 +5206,15 @@ out:
int bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
Error **errp)
{
+ assert(qemu_in_main_thread());
+
return bdrv_replace_node_common(from, to, true, false, errp);
}
int bdrv_drop_filter(BlockDriverState *bs, Error **errp)
{
+ assert(qemu_in_main_thread());
+
return bdrv_replace_node_common(bs, bdrv_filter_or_cow_bs(bs), true, true,
errp);
}
@@ -5183,6 +5237,8 @@ int bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
int ret;
Transaction *tran = tran_new();
+ assert(qemu_in_main_thread());
+
assert(!bs_new->backing);
ret = bdrv_attach_child_noperm(bs_new, bs_top, "backing",
@@ -5216,6 +5272,8 @@ int bdrv_replace_child_bs(BdrvChild *child, BlockDriverState *new_bs,
g_autoptr(GSList) refresh_list = NULL;
BlockDriverState *old_bs = child->bs;
+ assert(qemu_in_main_thread());
+
bdrv_ref(old_bs);
bdrv_drained_begin(old_bs);
bdrv_drained_begin(new_bs);
@@ -5287,6 +5345,8 @@ BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *options,
node_name = qdict_get_try_str(options, "node-name");
+ assert(qemu_in_main_thread());
+
new_node_bs = bdrv_new_open_driver_opts(drv, node_name, options, flags,
errp);
options = NULL; /* bdrv_new_open_driver() eats options */
@@ -5347,6 +5407,8 @@ int bdrv_change_backing_file(BlockDriverState *bs, const char *backing_file,
BlockDriver *drv = bs->drv;
int ret;
+ assert(qemu_in_main_thread());
+
if (!drv) {
return -ENOMEDIUM;
}
@@ -5388,6 +5450,9 @@ int bdrv_change_backing_file(BlockDriverState *bs, const char *backing_file,
BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
BlockDriverState *bs)
{
+
+ assert(qemu_in_main_thread());
+
bs = bdrv_skip_filters(bs);
active = bdrv_skip_filters(active);
@@ -5405,6 +5470,8 @@ BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
/* Given a BDS, searches for the base layer. */
BlockDriverState *bdrv_find_base(BlockDriverState *bs)
{
+ assert(qemu_in_main_thread());
+
return bdrv_find_overlay(bs, NULL);
}
@@ -5419,6 +5486,8 @@ bool bdrv_is_backing_chain_frozen(BlockDriverState *bs, BlockDriverState *base,
BlockDriverState *i;
BdrvChild *child;
+ assert(qemu_in_main_thread());
+
for (i = bs; i != base; i = child_bs(child)) {
child = bdrv_filter_or_cow_child(i);
@@ -5445,6 +5514,8 @@ int bdrv_freeze_backing_chain(BlockDriverState *bs, BlockDriverState *base,
BlockDriverState *i;
BdrvChild *child;
+ assert(qemu_in_main_thread());
+
if (bdrv_is_backing_chain_frozen(bs, base, errp)) {
return -EPERM;
}
@@ -5479,6 +5550,8 @@ void bdrv_unfreeze_backing_chain(BlockDriverState *bs, BlockDriverState *base)
BlockDriverState *i;
BdrvChild *child;
+ assert(qemu_in_main_thread());
+
for (i = bs; i != base; i = child_bs(child)) {
child = bdrv_filter_or_cow_child(i);
if (child) {
@@ -5528,6 +5601,8 @@ int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base,
g_autoptr(GSList) updated_children = NULL;
GSList *p;
+ assert(qemu_in_main_thread());
+
bdrv_ref(top);
bdrv_subtree_drained_begin(top);
@@ -5789,6 +5864,8 @@ void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
int i;
const char **formats = NULL;
+ assert(qemu_in_main_thread());
+
QLIST_FOREACH(drv, &bdrv_drivers, list) {
if (drv->format_name) {
bool found = false;
@@ -5847,6 +5924,7 @@ BlockDriverState *bdrv_find_node(const char *node_name)
BlockDriverState *bs;
assert(node_name);
+ assert(qemu_in_main_thread());
QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
if (!strcmp(node_name, bs->node_name)) {
@@ -5863,6 +5941,8 @@ BlockDeviceInfoList *bdrv_named_nodes_list(bool flat,
BlockDeviceInfoList *list;
BlockDriverState *bs;
+ assert(qemu_in_main_thread());
+
list = NULL;
QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
BlockDeviceInfo *info = bdrv_block_device_info(NULL, bs, flat, errp);
@@ -5968,6 +6048,8 @@ XDbgBlockGraph *bdrv_get_xdbg_block_graph(Error **errp)
BdrvChild *child;
XDbgBlockGraphConstructor *gr = xdbg_graph_new();
+ assert(qemu_in_main_thread());
+
for (blk = blk_all_next(NULL); blk; blk = blk_all_next(blk)) {
char *allocated_name = NULL;
const char *name = blk_name(blk);
@@ -6011,6 +6093,8 @@ BlockDriverState *bdrv_lookup_bs(const char *device,
BlockBackend *blk;
BlockDriverState *bs;
+ assert(qemu_in_main_thread());
+
if (device) {
blk = blk_by_name(device);
@@ -6042,6 +6126,9 @@ BlockDriverState *bdrv_lookup_bs(const char *device,
* return false. If either argument is NULL, return false. */
bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base)
{
+
+ assert(qemu_in_main_thread());
+
while (top && top != base) {
top = bdrv_filter_or_cow_bs(top);
}
@@ -6051,6 +6138,7 @@ bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base)
BlockDriverState *bdrv_next_node(BlockDriverState *bs)
{
+ assert(qemu_in_main_thread());
if (!bs) {
return QTAILQ_FIRST(&graph_bdrv_states);
}
@@ -6059,6 +6147,7 @@ BlockDriverState *bdrv_next_node(BlockDriverState *bs)
BlockDriverState *bdrv_next_all_states(BlockDriverState *bs)
{
+ assert(qemu_in_main_thread());
if (!bs) {
return QTAILQ_FIRST(&all_bdrv_states);
}
@@ -6105,17 +6194,20 @@ const char *bdrv_get_device_or_node_name(const BlockDriverState *bs)
int bdrv_get_flags(BlockDriverState *bs)
{
+ assert(qemu_in_main_thread());
return bs->open_flags;
}
int bdrv_has_zero_init_1(BlockDriverState *bs)
{
+ assert(qemu_in_main_thread());
return 1;
}
int bdrv_has_zero_init(BlockDriverState *bs)
{
BlockDriverState *filtered;
+ assert(qemu_in_main_thread());
if (!bs->drv) {
return 0;
@@ -6227,6 +6319,7 @@ static BlockDriverState *bdrv_find_debug_node(BlockDriverState *bs)
int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
const char *tag)
{
+ assert(qemu_in_main_thread());
bs = bdrv_find_debug_node(bs);
if (bs) {
return bs->drv->bdrv_debug_breakpoint(bs, event, tag);
@@ -6237,6 +6330,7 @@ int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag)
{
+ assert(qemu_in_main_thread());
bs = bdrv_find_debug_node(bs);
if (bs) {
return bs->drv->bdrv_debug_remove_breakpoint(bs, tag);
@@ -6247,6 +6341,7 @@ int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag)
int bdrv_debug_resume(BlockDriverState *bs, const char *tag)
{
+ assert(qemu_in_main_thread());
while (bs && (!bs->drv || !bs->drv->bdrv_debug_resume)) {
bs = bdrv_primary_bs(bs);
}
@@ -6260,6 +6355,7 @@ int bdrv_debug_resume(BlockDriverState *bs, const char *tag)
bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag)
{
+ assert(qemu_in_main_thread());
while (bs && bs->drv && !bs->drv->bdrv_debug_is_suspended) {
bs = bdrv_primary_bs(bs);
}
@@ -6287,6 +6383,8 @@ BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
BlockDriverState *retval = NULL;
BlockDriverState *bs_below;
+ assert(qemu_in_main_thread());
+
if (!bs || !bs->drv || !backing_file) {
return NULL;
}
@@ -6385,6 +6483,7 @@ BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
void bdrv_init(void)
{
+ assert(qemu_in_main_thread());
#ifdef CONFIG_BDRV_WHITELIST_TOOLS
use_bdrv_whitelist = 1;
#endif
@@ -6393,6 +6492,7 @@ void bdrv_init(void)
void bdrv_init_with_whitelist(void)
{
+ assert(qemu_in_main_thread());
use_bdrv_whitelist = 1;
bdrv_init();
}
@@ -6477,6 +6577,8 @@ void bdrv_invalidate_cache_all(Error **errp)
BlockDriverState *bs;
BdrvNextIterator it;
+ assert(qemu_in_main_thread());
+
for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
AioContext *aio_context = bdrv_get_aio_context(bs);
int ret;
@@ -6576,6 +6678,8 @@ int bdrv_inactivate_all(void)
int ret = 0;
GSList *aio_ctxs = NULL, *ctx;
+ assert(qemu_in_main_thread());
+
for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
AioContext *aio_context = bdrv_get_aio_context(bs);
@@ -6653,6 +6757,7 @@ void bdrv_eject(BlockDriverState *bs, bool eject_flag)
void bdrv_lock_medium(BlockDriverState *bs, bool locked)
{
BlockDriver *drv = bs->drv;
+ assert(qemu_in_main_thread());
trace_bdrv_lock_medium(bs, locked);
@@ -6664,6 +6769,7 @@ void bdrv_lock_medium(BlockDriverState *bs, bool locked)
/* Get a reference to bs */
void bdrv_ref(BlockDriverState *bs)
{
+ assert(qemu_in_main_thread());
bs->refcnt++;
}
@@ -6672,6 +6778,7 @@ void bdrv_ref(BlockDriverState *bs)
* deleted. */
void bdrv_unref(BlockDriverState *bs)
{
+ assert(qemu_in_main_thread());
if (!bs) {
return;
}
@@ -6689,6 +6796,7 @@ struct BdrvOpBlocker {
bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp)
{
BdrvOpBlocker *blocker;
+ assert(qemu_in_main_thread());
assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
if (!QLIST_EMPTY(&bs->op_blockers[op])) {
blocker = QLIST_FIRST(&bs->op_blockers[op]);
@@ -6703,6 +6811,7 @@ bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp)
void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason)
{
BdrvOpBlocker *blocker;
+ assert(qemu_in_main_thread());
assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
blocker = g_new0(BdrvOpBlocker, 1);
@@ -6713,6 +6822,7 @@ void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason)
void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason)
{
BdrvOpBlocker *blocker, *next;
+ assert(qemu_in_main_thread());
assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
QLIST_FOREACH_SAFE(blocker, &bs->op_blockers[op], list, next) {
if (blocker->reason == reason) {
@@ -6725,6 +6835,7 @@ void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason)
void bdrv_op_block_all(BlockDriverState *bs, Error *reason)
{
int i;
+ assert(qemu_in_main_thread());
for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
bdrv_op_block(bs, i, reason);
}
@@ -6733,6 +6844,7 @@ void bdrv_op_block_all(BlockDriverState *bs, Error *reason)
void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason)
{
int i;
+ assert(qemu_in_main_thread());
for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
bdrv_op_unblock(bs, i, reason);
}
@@ -6741,7 +6853,7 @@ void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason)
bool bdrv_op_blocker_is_empty(BlockDriverState *bs)
{
int i;
-
+ assert(qemu_in_main_thread());
for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
if (!QLIST_EMPTY(&bs->op_blockers[i])) {
return false;
@@ -6763,6 +6875,8 @@ void bdrv_img_create(const char *filename, const char *fmt,
Error *local_err = NULL;
int ret = 0;
+ assert(qemu_in_main_thread());
+
/* Find driver and parse its options */
drv = bdrv_find_format(fmt);
if (!drv) {
@@ -7179,6 +7293,7 @@ static bool bdrv_parent_can_set_aio_context(BdrvChild *c, AioContext *ctx,
bool bdrv_child_can_set_aio_context(BdrvChild *c, AioContext *ctx,
GSList **ignore, Error **errp)
{
+ assert(qemu_in_main_thread());
if (g_slist_find(*ignore, c)) {
return true;
}
@@ -7197,6 +7312,8 @@ bool bdrv_can_set_aio_context(BlockDriverState *bs, AioContext *ctx,
return true;
}
+ assert(qemu_in_main_thread());
+
QLIST_FOREACH(c, &bs->parents, next_parent) {
if (!bdrv_parent_can_set_aio_context(c, ctx, ignore, errp)) {
return false;
@@ -7217,6 +7334,8 @@ int bdrv_child_try_set_aio_context(BlockDriverState *bs, AioContext *ctx,
GSList *ignore;
bool ret;
+ assert(qemu_in_main_thread());
+
ignore = ignore_child ? g_slist_prepend(NULL, ignore_child) : NULL;
ret = bdrv_can_set_aio_context(bs, ctx, &ignore, errp);
g_slist_free(ignore);
@@ -7235,6 +7354,7 @@ int bdrv_child_try_set_aio_context(BlockDriverState *bs, AioContext *ctx,
int bdrv_try_set_aio_context(BlockDriverState *bs, AioContext *ctx,
Error **errp)
{
+ assert(qemu_in_main_thread());
return bdrv_child_try_set_aio_context(bs, ctx, NULL, errp);
}
@@ -7248,6 +7368,7 @@ void bdrv_add_aio_context_notifier(BlockDriverState *bs,
.detach_aio_context = detach_aio_context,
.opaque = opaque
};
+ assert(qemu_in_main_thread());
QLIST_INSERT_HEAD(&bs->aio_notifiers, ban, list);
}
@@ -7259,6 +7380,7 @@ void bdrv_remove_aio_context_notifier(BlockDriverState *bs,
void *opaque)
{
BdrvAioNotifier *ban, *ban_next;
+ assert(qemu_in_main_thread());
QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) {
if (ban->attached_aio_context == attached_aio_context &&
@@ -7283,6 +7405,7 @@ int bdrv_amend_options(BlockDriverState *bs, QemuOpts *opts,
bool force,
Error **errp)
{
+ assert(qemu_in_main_thread());
if (!bs->drv) {
error_setg(errp, "Node is ejected");
return -ENOMEDIUM;
@@ -7353,6 +7476,8 @@ BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
BlockDriverState *to_replace_bs = bdrv_find_node(node_name);
AioContext *aio_context;
+ assert(qemu_in_main_thread());
+
if (!to_replace_bs) {
error_setg(errp, "Failed to find node with node-name='%s'", node_name);
return NULL;
@@ -7514,6 +7639,8 @@ void bdrv_refresh_filename(BlockDriverState *bs)
bool generate_json_filename; /* Whether our default implementation should
fill exact_filename (false) or not (true) */
+ assert(qemu_in_main_thread());
+
if (!drv) {
return;
}
@@ -7636,6 +7763,8 @@ char *bdrv_dirname(BlockDriverState *bs, Error **errp)
BlockDriver *drv = bs->drv;
BlockDriverState *child_bs;
+ assert(qemu_in_main_thread());
+
if (!drv) {
error_setg(errp, "Node '%s' is ejected", bs->node_name);
return NULL;
@@ -7667,7 +7796,7 @@ char *bdrv_dirname(BlockDriverState *bs, Error **errp)
void bdrv_add_child(BlockDriverState *parent_bs, BlockDriverState *child_bs,
Error **errp)
{
-
+ assert(qemu_in_main_thread());
if (!parent_bs->drv || !parent_bs->drv->bdrv_add_child) {
error_setg(errp, "The node %s does not support adding a child",
bdrv_get_device_or_node_name(parent_bs));
@@ -7687,6 +7816,7 @@ void bdrv_del_child(BlockDriverState *parent_bs, BdrvChild *child, Error **errp)
{
BdrvChild *tmp;
+ assert(qemu_in_main_thread());
if (!parent_bs->drv || !parent_bs->drv->bdrv_del_child) {
error_setg(errp, "The node %s does not support removing a child",
bdrv_get_device_or_node_name(parent_bs));
@@ -7714,6 +7844,7 @@ int bdrv_make_empty(BdrvChild *c, Error **errp)
BlockDriver *drv = c->bs->drv;
int ret;
+ assert(qemu_in_main_thread());
assert(c->perm & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED));
if (!drv->bdrv_make_empty) {
diff --git a/block/commit.c b/block/commit.c
index 10cc5ff451..45a414a19b 100644
--- a/block/commit.c
+++ b/block/commit.c
@@ -433,6 +433,8 @@ int bdrv_commit(BlockDriverState *bs)
QEMU_AUTO_VFREE uint8_t *buf = NULL;
Error *local_err = NULL;
+ assert(qemu_in_main_thread());
+
if (!drv)
return -ENOMEDIUM;
diff --git a/block/io.c b/block/io.c
index bb0a254def..51497d1b27 100644
--- a/block/io.c
+++ b/block/io.c
@@ -164,6 +164,8 @@ void bdrv_refresh_limits(BlockDriverState *bs, Transaction *tran, Error **errp)
BdrvChild *c;
bool have_limits;
+ assert(qemu_in_main_thread());
+
if (tran) {
BdrvRefreshLimitsState *s = g_new(BdrvRefreshLimitsState, 1);
*s = (BdrvRefreshLimitsState) {
@@ -612,6 +614,7 @@ static bool bdrv_drain_all_poll(void)
{
BlockDriverState *bs = NULL;
bool result = false;
+ assert(qemu_in_main_thread());
/* bdrv_drain_poll() can't make changes to the graph and we are holding the
* main AioContext lock, so iterating bdrv_next_all_states() is safe. */
@@ -640,6 +643,7 @@ static bool bdrv_drain_all_poll(void)
void bdrv_drain_all_begin(void)
{
BlockDriverState *bs = NULL;
+ assert(qemu_in_main_thread());
if (qemu_in_coroutine()) {
bdrv_co_yield_to_drain(NULL, true, false, NULL, true, true, NULL);
@@ -696,6 +700,7 @@ void bdrv_drain_all_end(void)
{
BlockDriverState *bs = NULL;
int drained_end_counter = 0;
+ assert(qemu_in_main_thread());
/*
* bdrv queue is managed by record/replay,
@@ -723,6 +728,7 @@ void bdrv_drain_all_end(void)
void bdrv_drain_all(void)
{
+ assert(qemu_in_main_thread());
bdrv_drain_all_begin();
bdrv_drain_all_end();
}
@@ -1059,6 +1065,8 @@ int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags)
int64_t target_size, bytes, offset = 0;
BlockDriverState *bs = child->bs;
+ assert(qemu_in_main_thread());
+
target_size = bdrv_getlength(bs);
if (target_size < 0) {
return target_size;
@@ -2345,6 +2353,8 @@ int bdrv_flush_all(void)
BlockDriverState *bs = NULL;
int result = 0;
+ assert(qemu_in_main_thread());
+
/*
* bdrv queue is managed by record/replay,
* creating new flush request for stopping
@@ -2898,6 +2908,7 @@ int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
void bdrv_aio_cancel(BlockAIOCB *acb)
{
+ assert(qemu_in_main_thread());
qemu_aio_ref(acb);
bdrv_aio_cancel_async(acb);
while (acb->refcnt > 1) {
@@ -3292,6 +3303,7 @@ void bdrv_register_buf(BlockDriverState *bs, void *host, size_t size)
{
BdrvChild *child;
+ assert(qemu_in_main_thread());
if (bs->drv && bs->drv->bdrv_register_buf) {
bs->drv->bdrv_register_buf(bs, host, size);
}
@@ -3304,6 +3316,7 @@ void bdrv_unregister_buf(BlockDriverState *bs, void *host)
{
BdrvChild *child;
+ assert(qemu_in_main_thread());
if (bs->drv && bs->drv->bdrv_unregister_buf) {
bs->drv->bdrv_unregister_buf(bs, host);
}
@@ -3575,6 +3588,7 @@ out:
void bdrv_cancel_in_flight(BlockDriverState *bs)
{
+ assert(qemu_in_main_thread());
if (!bs || !bs->drv) {
return;
}
diff --git a/blockdev.c b/blockdev.c
index 84897f9d70..750ff40d41 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -648,6 +648,7 @@ void blockdev_close_all_bdrv_states(void)
/* Iterates over the list of monitor-owned BlockDriverStates */
BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs)
{
+ assert(qemu_in_main_thread());
return bs ? QTAILQ_NEXT(bs, monitor_list)
: QTAILQ_FIRST(&monitor_bdrv_states);
}
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 04/31] include/sysemu/block-backend: split header into I/O and global state (GS) API
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (2 preceding siblings ...)
2021-11-24 6:43 ` [PATCH v5 03/31] assertions for block " Emanuele Giuseppe Esposito
@ 2021-11-24 6:43 ` Emanuele Giuseppe Esposito
2021-12-10 14:21 ` Hanna Reitz
2021-11-24 6:43 ` [PATCH v5 05/31] block-backend: special comments for blk_set/get_perm due to fuse Emanuele Giuseppe Esposito
` (27 subsequent siblings)
31 siblings, 1 reply; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:43 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
Similarly to the previous patches, split block-backend.h
in block-backend-io.h and block-backend-global-state.h
In addition, remove "block/block.h" include as it seems
it is not necessary anymore, together with "qemu/iov.h"
block-backend-common.h contains the structures shared between
the two headers, and the functions that can't be categorized as
I/O or global state.
Assertions are added in the next patch.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
include/sysemu/block-backend-common.h | 84 ++++++
include/sysemu/block-backend-global-state.h | 121 +++++++++
include/sysemu/block-backend-io.h | 139 ++++++++++
include/sysemu/block-backend.h | 269 +-------------------
block/block-backend.c | 9 +-
5 files changed, 353 insertions(+), 269 deletions(-)
create mode 100644 include/sysemu/block-backend-common.h
create mode 100644 include/sysemu/block-backend-global-state.h
create mode 100644 include/sysemu/block-backend-io.h
diff --git a/include/sysemu/block-backend-common.h b/include/sysemu/block-backend-common.h
new file mode 100644
index 0000000000..6963bbf45a
--- /dev/null
+++ b/include/sysemu/block-backend-common.h
@@ -0,0 +1,84 @@
+/*
+ * QEMU Block backends
+ *
+ * Copyright (C) 2014-2016 Red Hat, Inc.
+ *
+ * Authors:
+ * Markus Armbruster <armbru@redhat.com>,
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.1
+ * or later. See the COPYING.LIB file in the top-level directory.
+ */
+
+#ifndef BLOCK_BACKEND_COMMON_H
+#define BLOCK_BACKEND_COMMON_H
+
+#include "qemu/iov.h"
+#include "block/throttle-groups.h"
+
+/*
+ * TODO Have to include block/block.h for a bunch of block layer
+ * types. Unfortunately, this pulls in the whole BlockDriverState
+ * API, which we don't want used by many BlockBackend users. Some of
+ * the types belong here, and the rest should be split into a common
+ * header and one for the BlockDriverState API.
+ */
+#include "block/block.h"
+
+/* Callbacks for block device models */
+typedef struct BlockDevOps {
+ /*
+ * Runs when virtual media changed (monitor commands eject, change)
+ * Argument load is true on load and false on eject.
+ * Beware: doesn't run when a host device's physical media
+ * changes. Sure would be useful if it did.
+ * Device models with removable media must implement this callback.
+ */
+ void (*change_media_cb)(void *opaque, bool load, Error **errp);
+ /*
+ * Runs when an eject request is issued from the monitor, the tray
+ * is closed, and the medium is locked.
+ * Device models that do not implement is_medium_locked will not need
+ * this callback. Device models that can lock the medium or tray might
+ * want to implement the callback and unlock the tray when "force" is
+ * true, even if they do not support eject requests.
+ */
+ void (*eject_request_cb)(void *opaque, bool force);
+ /*
+ * Is the virtual tray open?
+ * Device models implement this only when the device has a tray.
+ */
+ bool (*is_tray_open)(void *opaque);
+ /*
+ * Is the virtual medium locked into the device?
+ * Device models implement this only when device has such a lock.
+ */
+ bool (*is_medium_locked)(void *opaque);
+ /*
+ * Runs when the size changed (e.g. monitor command block_resize)
+ */
+ void (*resize_cb)(void *opaque);
+ /*
+ * Runs when the backend receives a drain request.
+ */
+ void (*drained_begin)(void *opaque);
+ /*
+ * Runs when the backend's last drain request ends.
+ */
+ void (*drained_end)(void *opaque);
+ /*
+ * Is the device still busy?
+ */
+ bool (*drained_poll)(void *opaque);
+} BlockDevOps;
+
+/*
+ * This struct is embedded in (the private) BlockBackend struct and contains
+ * fields that must be public. This is in particular for QLIST_ENTRY() and
+ * friends so that BlockBackends can be kept in lists outside block-backend.c
+ */
+typedef struct BlockBackendPublic {
+ ThrottleGroupMember throttle_group_member;
+} BlockBackendPublic;
+
+#endif /* BLOCK_BACKEND_COMMON_H */
diff --git a/include/sysemu/block-backend-global-state.h b/include/sysemu/block-backend-global-state.h
new file mode 100644
index 0000000000..77009bf7a2
--- /dev/null
+++ b/include/sysemu/block-backend-global-state.h
@@ -0,0 +1,121 @@
+/*
+ * QEMU Block backends
+ *
+ * Copyright (C) 2014-2016 Red Hat, Inc.
+ *
+ * Authors:
+ * Markus Armbruster <armbru@redhat.com>,
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.1
+ * or later. See the COPYING.LIB file in the top-level directory.
+ */
+
+#ifndef BLOCK_BACKEND_GS_H
+#define BLOCK_BACKEND_GS_H
+
+#include "block-backend-common.h"
+
+/*
+ * Global state (GS) API. These functions run under the BQL lock.
+ *
+ * See include/block/block-global-state.h for more information about
+ * the GS API.
+ */
+
+BlockBackend *blk_new(AioContext *ctx, uint64_t perm, uint64_t shared_perm);
+BlockBackend *blk_new_with_bs(BlockDriverState *bs, uint64_t perm,
+ uint64_t shared_perm, Error **errp);
+BlockBackend *blk_new_open(const char *filename, const char *reference,
+ QDict *options, int flags, Error **errp);
+int blk_get_refcnt(BlockBackend *blk);
+void blk_ref(BlockBackend *blk);
+void blk_unref(BlockBackend *blk);
+void blk_remove_all_bs(void);
+BlockBackend *blk_by_name(const char *name);
+BlockBackend *blk_next(BlockBackend *blk);
+BlockBackend *blk_all_next(BlockBackend *blk);
+bool monitor_add_blk(BlockBackend *blk, const char *name, Error **errp);
+void monitor_remove_blk(BlockBackend *blk);
+
+BlockBackendPublic *blk_get_public(BlockBackend *blk);
+BlockBackend *blk_by_public(BlockBackendPublic *public);
+
+void blk_remove_bs(BlockBackend *blk);
+int blk_insert_bs(BlockBackend *blk, BlockDriverState *bs, Error **errp);
+int blk_replace_bs(BlockBackend *blk, BlockDriverState *new_bs, Error **errp);
+bool bdrv_has_blk(BlockDriverState *bs);
+bool bdrv_is_root_node(BlockDriverState *bs);
+int blk_set_perm(BlockBackend *blk, uint64_t perm, uint64_t shared_perm,
+ Error **errp);
+void blk_get_perm(BlockBackend *blk, uint64_t *perm, uint64_t *shared_perm);
+
+void blk_iostatus_enable(BlockBackend *blk);
+bool blk_iostatus_is_enabled(const BlockBackend *blk);
+BlockDeviceIoStatus blk_iostatus(const BlockBackend *blk);
+void blk_iostatus_disable(BlockBackend *blk);
+void blk_iostatus_reset(BlockBackend *blk);
+void blk_iostatus_set_err(BlockBackend *blk, int error);
+int blk_attach_dev(BlockBackend *blk, DeviceState *dev);
+void blk_detach_dev(BlockBackend *blk, DeviceState *dev);
+DeviceState *blk_get_attached_dev(BlockBackend *blk);
+char *blk_get_attached_dev_id(BlockBackend *blk);
+BlockBackend *blk_by_dev(void *dev);
+BlockBackend *blk_by_qdev_id(const char *id, Error **errp);
+void blk_set_dev_ops(BlockBackend *blk, const BlockDevOps *ops, void *opaque);
+int blk_ioctl(BlockBackend *blk, unsigned long int req, void *buf);
+
+int blk_make_zero(BlockBackend *blk, BdrvRequestFlags flags);
+void blk_aio_cancel(BlockAIOCB *acb);
+int blk_commit_all(void);
+void blk_drain_all(void);
+void blk_set_on_error(BlockBackend *blk, BlockdevOnError on_read_error,
+ BlockdevOnError on_write_error);
+bool blk_supports_write_perm(BlockBackend *blk);
+bool blk_is_sg(BlockBackend *blk);
+bool blk_enable_write_cache(BlockBackend *blk);
+void blk_set_enable_write_cache(BlockBackend *blk, bool wce);
+void blk_lock_medium(BlockBackend *blk, bool locked);
+void blk_eject(BlockBackend *blk, bool eject_flag);
+int blk_get_flags(BlockBackend *blk);
+void blk_set_guest_block_size(BlockBackend *blk, int align);
+bool blk_op_is_blocked(BlockBackend *blk, BlockOpType op, Error **errp);
+void blk_op_unblock(BlockBackend *blk, BlockOpType op, Error *reason);
+void blk_op_block_all(BlockBackend *blk, Error *reason);
+void blk_op_unblock_all(BlockBackend *blk, Error *reason);
+int blk_set_aio_context(BlockBackend *blk, AioContext *new_context,
+ Error **errp);
+void blk_add_aio_context_notifier(BlockBackend *blk,
+ void (*attached_aio_context)(AioContext *new_context, void *opaque),
+ void (*detach_aio_context)(void *opaque), void *opaque);
+void blk_remove_aio_context_notifier(BlockBackend *blk,
+ void (*attached_aio_context)(AioContext *,
+ void *),
+ void (*detach_aio_context)(void *),
+ void *opaque);
+void blk_add_remove_bs_notifier(BlockBackend *blk, Notifier *notify);
+void blk_add_insert_bs_notifier(BlockBackend *blk, Notifier *notify);
+BlockBackendRootState *blk_get_root_state(BlockBackend *blk);
+void blk_update_root_state(BlockBackend *blk);
+bool blk_get_detect_zeroes_from_root_state(BlockBackend *blk);
+int blk_get_open_flags_from_root_state(BlockBackend *blk);
+
+int blk_save_vmstate(BlockBackend *blk, const uint8_t *buf,
+ int64_t pos, int size);
+int blk_load_vmstate(BlockBackend *blk, uint8_t *buf, int64_t pos, int size);
+int blk_probe_blocksizes(BlockBackend *blk, BlockSizes *bsz);
+int blk_probe_geometry(BlockBackend *blk, HDGeometry *geo);
+
+void blk_set_io_limits(BlockBackend *blk, ThrottleConfig *cfg);
+void blk_io_limits_disable(BlockBackend *blk);
+void blk_io_limits_enable(BlockBackend *blk, const char *group);
+void blk_io_limits_update_group(BlockBackend *blk, const char *group);
+void blk_set_force_allow_inactivate(BlockBackend *blk);
+
+void blk_register_buf(BlockBackend *blk, void *host, size_t size);
+void blk_unregister_buf(BlockBackend *blk, void *host);
+
+const BdrvChild *blk_root(BlockBackend *blk);
+
+int blk_make_empty(BlockBackend *blk, Error **errp);
+
+#endif /* BLOCK_BACKEND_GS_H */
diff --git a/include/sysemu/block-backend-io.h b/include/sysemu/block-backend-io.h
new file mode 100644
index 0000000000..b85f46dfd7
--- /dev/null
+++ b/include/sysemu/block-backend-io.h
@@ -0,0 +1,139 @@
+/*
+ * QEMU Block backends
+ *
+ * Copyright (C) 2014-2016 Red Hat, Inc.
+ *
+ * Authors:
+ * Markus Armbruster <armbru@redhat.com>,
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.1
+ * or later. See the COPYING.LIB file in the top-level directory.
+ */
+
+#ifndef BLOCK_BACKEND_IO_H
+#define BLOCK_BACKEND_IO_H
+
+#include "block-backend-common.h"
+
+/*
+ * I/O API functions. These functions are thread-safe.
+ *
+ * See include/block/block-io.h for more information about
+ * the I/O API.
+ */
+
+const char *blk_name(const BlockBackend *blk);
+
+BlockDriverState *blk_bs(BlockBackend *blk);
+
+void blk_set_allow_write_beyond_eof(BlockBackend *blk, bool allow);
+void blk_set_allow_aio_context_change(BlockBackend *blk, bool allow);
+void blk_set_disable_request_queuing(BlockBackend *blk, bool disable);
+
+int blk_pread(BlockBackend *blk, int64_t offset, void *buf, int bytes);
+int blk_pwrite(BlockBackend *blk, int64_t offset, const void *buf, int bytes,
+ BdrvRequestFlags flags);
+int coroutine_fn blk_co_preadv(BlockBackend *blk, int64_t offset,
+ int64_t bytes, QEMUIOVector *qiov,
+ BdrvRequestFlags flags);
+int coroutine_fn blk_co_pwritev_part(BlockBackend *blk, int64_t offset,
+ int64_t bytes,
+ QEMUIOVector *qiov, size_t qiov_offset,
+ BdrvRequestFlags flags);
+int coroutine_fn blk_co_pwritev(BlockBackend *blk, int64_t offset,
+ int64_t bytes, QEMUIOVector *qiov,
+ BdrvRequestFlags flags);
+
+static inline int coroutine_fn blk_co_pread(BlockBackend *blk, int64_t offset,
+ int64_t bytes, void *buf,
+ BdrvRequestFlags flags)
+{
+ QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
+
+ assert(bytes <= SIZE_MAX);
+
+ return blk_co_preadv(blk, offset, bytes, &qiov, flags);
+}
+
+static inline int coroutine_fn blk_co_pwrite(BlockBackend *blk, int64_t offset,
+ int64_t bytes, void *buf,
+ BdrvRequestFlags flags)
+{
+ QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
+
+ assert(bytes <= SIZE_MAX);
+
+ return blk_co_pwritev(blk, offset, bytes, &qiov, flags);
+}
+
+BlockAIOCB *blk_aio_pwrite_zeroes(BlockBackend *blk, int64_t offset,
+ int64_t bytes, BdrvRequestFlags flags,
+ BlockCompletionFunc *cb, void *opaque);
+
+BlockAIOCB *blk_aio_preadv(BlockBackend *blk, int64_t offset,
+ QEMUIOVector *qiov, BdrvRequestFlags flags,
+ BlockCompletionFunc *cb, void *opaque);
+BlockAIOCB *blk_aio_pwritev(BlockBackend *blk, int64_t offset,
+ QEMUIOVector *qiov, BdrvRequestFlags flags,
+ BlockCompletionFunc *cb, void *opaque);
+BlockAIOCB *blk_aio_flush(BlockBackend *blk,
+ BlockCompletionFunc *cb, void *opaque);
+BlockAIOCB *blk_aio_pdiscard(BlockBackend *blk, int64_t offset, int64_t bytes,
+ BlockCompletionFunc *cb, void *opaque);
+void blk_aio_cancel_async(BlockAIOCB *acb);
+BlockAIOCB *blk_aio_ioctl(BlockBackend *blk, unsigned long int req, void *buf,
+ BlockCompletionFunc *cb, void *opaque);
+int coroutine_fn blk_co_pdiscard(BlockBackend *blk, int64_t offset,
+ int64_t bytes);
+int coroutine_fn blk_co_flush(BlockBackend *blk);
+int blk_flush(BlockBackend *blk);
+void blk_inc_in_flight(BlockBackend *blk);
+void blk_dec_in_flight(BlockBackend *blk);
+void blk_drain(BlockBackend *blk);
+bool blk_is_inserted(BlockBackend *blk);
+bool blk_is_available(BlockBackend *blk);
+int64_t blk_getlength(BlockBackend *blk);
+void blk_get_geometry(BlockBackend *blk, uint64_t *nb_sectors_ptr);
+int64_t blk_nb_sectors(BlockBackend *blk);
+void *blk_try_blockalign(BlockBackend *blk, size_t size);
+void *blk_blockalign(BlockBackend *blk, size_t size);
+bool blk_is_writable(BlockBackend *blk);
+BlockdevOnError blk_get_on_error(BlockBackend *blk, bool is_read);
+BlockErrorAction blk_get_error_action(BlockBackend *blk, bool is_read,
+ int error);
+void blk_error_action(BlockBackend *blk, BlockErrorAction action,
+ bool is_read, int error);
+int blk_get_max_iov(BlockBackend *blk);
+int blk_get_max_hw_iov(BlockBackend *blk);
+
+void blk_invalidate_cache(BlockBackend *blk, Error **errp);
+
+void blk_io_plug(BlockBackend *blk);
+void blk_io_unplug(BlockBackend *blk);
+AioContext *blk_get_aio_context(BlockBackend *blk);
+BlockAcctStats *blk_get_stats(BlockBackend *blk);
+void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk,
+ BlockCompletionFunc *cb, void *opaque);
+int blk_pwrite_compressed(BlockBackend *blk, int64_t offset, const void *buf,
+ int64_t bytes);
+int blk_pdiscard(BlockBackend *blk, int64_t offset, int64_t bytes);
+int blk_pwrite_zeroes(BlockBackend *blk, int64_t offset,
+ int64_t bytes, BdrvRequestFlags flags);
+int coroutine_fn blk_co_pwrite_zeroes(BlockBackend *blk, int64_t offset,
+ int64_t bytes, BdrvRequestFlags flags);
+int blk_truncate(BlockBackend *blk, int64_t offset, bool exact,
+ PreallocMode prealloc, BdrvRequestFlags flags, Error **errp);
+BlockAIOCB *blk_abort_aio_request(BlockBackend *blk,
+ BlockCompletionFunc *cb,
+ void *opaque, int ret);
+
+uint32_t blk_get_request_alignment(BlockBackend *blk);
+uint32_t blk_get_max_transfer(BlockBackend *blk);
+uint64_t blk_get_max_hw_transfer(BlockBackend *blk);
+
+int coroutine_fn blk_co_copy_range(BlockBackend *blk_in, int64_t off_in,
+ BlockBackend *blk_out, int64_t off_out,
+ int64_t bytes, BdrvRequestFlags read_flags,
+ BdrvRequestFlags write_flags);
+
+#endif /* BLOCK_BACKEND_IO_H */
diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
index e5e1524f06..038be9fc40 100644
--- a/include/sysemu/block-backend.h
+++ b/include/sysemu/block-backend.h
@@ -13,272 +13,9 @@
#ifndef BLOCK_BACKEND_H
#define BLOCK_BACKEND_H
-#include "qemu/iov.h"
-#include "block/throttle-groups.h"
+#include "block-backend-global-state.h"
+#include "block-backend-io.h"
-/*
- * TODO Have to include block/block.h for a bunch of block layer
- * types. Unfortunately, this pulls in the whole BlockDriverState
- * API, which we don't want used by many BlockBackend users. Some of
- * the types belong here, and the rest should be split into a common
- * header and one for the BlockDriverState API.
- */
-#include "block/block.h"
-
-/* Callbacks for block device models */
-typedef struct BlockDevOps {
- /*
- * Runs when virtual media changed (monitor commands eject, change)
- * Argument load is true on load and false on eject.
- * Beware: doesn't run when a host device's physical media
- * changes. Sure would be useful if it did.
- * Device models with removable media must implement this callback.
- */
- void (*change_media_cb)(void *opaque, bool load, Error **errp);
- /*
- * Runs when an eject request is issued from the monitor, the tray
- * is closed, and the medium is locked.
- * Device models that do not implement is_medium_locked will not need
- * this callback. Device models that can lock the medium or tray might
- * want to implement the callback and unlock the tray when "force" is
- * true, even if they do not support eject requests.
- */
- void (*eject_request_cb)(void *opaque, bool force);
- /*
- * Is the virtual tray open?
- * Device models implement this only when the device has a tray.
- */
- bool (*is_tray_open)(void *opaque);
- /*
- * Is the virtual medium locked into the device?
- * Device models implement this only when device has such a lock.
- */
- bool (*is_medium_locked)(void *opaque);
- /*
- * Runs when the size changed (e.g. monitor command block_resize)
- */
- void (*resize_cb)(void *opaque);
- /*
- * Runs when the backend receives a drain request.
- */
- void (*drained_begin)(void *opaque);
- /*
- * Runs when the backend's last drain request ends.
- */
- void (*drained_end)(void *opaque);
- /*
- * Is the device still busy?
- */
- bool (*drained_poll)(void *opaque);
-} BlockDevOps;
-
-/* This struct is embedded in (the private) BlockBackend struct and contains
- * fields that must be public. This is in particular for QLIST_ENTRY() and
- * friends so that BlockBackends can be kept in lists outside block-backend.c
- * */
-typedef struct BlockBackendPublic {
- ThrottleGroupMember throttle_group_member;
-} BlockBackendPublic;
-
-BlockBackend *blk_new(AioContext *ctx, uint64_t perm, uint64_t shared_perm);
-BlockBackend *blk_new_with_bs(BlockDriverState *bs, uint64_t perm,
- uint64_t shared_perm, Error **errp);
-BlockBackend *blk_new_open(const char *filename, const char *reference,
- QDict *options, int flags, Error **errp);
-int blk_get_refcnt(BlockBackend *blk);
-void blk_ref(BlockBackend *blk);
-void blk_unref(BlockBackend *blk);
-void blk_remove_all_bs(void);
-const char *blk_name(const BlockBackend *blk);
-BlockBackend *blk_by_name(const char *name);
-BlockBackend *blk_next(BlockBackend *blk);
-BlockBackend *blk_all_next(BlockBackend *blk);
-bool monitor_add_blk(BlockBackend *blk, const char *name, Error **errp);
-void monitor_remove_blk(BlockBackend *blk);
-
-BlockBackendPublic *blk_get_public(BlockBackend *blk);
-BlockBackend *blk_by_public(BlockBackendPublic *public);
-
-BlockDriverState *blk_bs(BlockBackend *blk);
-void blk_remove_bs(BlockBackend *blk);
-int blk_insert_bs(BlockBackend *blk, BlockDriverState *bs, Error **errp);
-int blk_replace_bs(BlockBackend *blk, BlockDriverState *new_bs, Error **errp);
-bool bdrv_has_blk(BlockDriverState *bs);
-bool bdrv_is_root_node(BlockDriverState *bs);
-int blk_set_perm(BlockBackend *blk, uint64_t perm, uint64_t shared_perm,
- Error **errp);
-void blk_get_perm(BlockBackend *blk, uint64_t *perm, uint64_t *shared_perm);
-
-void blk_set_allow_write_beyond_eof(BlockBackend *blk, bool allow);
-void blk_set_allow_aio_context_change(BlockBackend *blk, bool allow);
-void blk_set_disable_request_queuing(BlockBackend *blk, bool disable);
-void blk_iostatus_enable(BlockBackend *blk);
-bool blk_iostatus_is_enabled(const BlockBackend *blk);
-BlockDeviceIoStatus blk_iostatus(const BlockBackend *blk);
-void blk_iostatus_disable(BlockBackend *blk);
-void blk_iostatus_reset(BlockBackend *blk);
-void blk_iostatus_set_err(BlockBackend *blk, int error);
-int blk_attach_dev(BlockBackend *blk, DeviceState *dev);
-void blk_detach_dev(BlockBackend *blk, DeviceState *dev);
-DeviceState *blk_get_attached_dev(BlockBackend *blk);
-char *blk_get_attached_dev_id(BlockBackend *blk);
-BlockBackend *blk_by_dev(void *dev);
-BlockBackend *blk_by_qdev_id(const char *id, Error **errp);
-void blk_set_dev_ops(BlockBackend *blk, const BlockDevOps *ops, void *opaque);
-int coroutine_fn blk_co_preadv(BlockBackend *blk, int64_t offset,
- int64_t bytes, QEMUIOVector *qiov,
- BdrvRequestFlags flags);
-int coroutine_fn blk_co_pwritev_part(BlockBackend *blk, int64_t offset,
- int64_t bytes,
- QEMUIOVector *qiov, size_t qiov_offset,
- BdrvRequestFlags flags);
-int coroutine_fn blk_co_pwritev(BlockBackend *blk, int64_t offset,
- int64_t bytes, QEMUIOVector *qiov,
- BdrvRequestFlags flags);
-
-static inline int coroutine_fn blk_co_pread(BlockBackend *blk, int64_t offset,
- int64_t bytes, void *buf,
- BdrvRequestFlags flags)
-{
- QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
-
- assert(bytes <= SIZE_MAX);
-
- return blk_co_preadv(blk, offset, bytes, &qiov, flags);
-}
-
-static inline int coroutine_fn blk_co_pwrite(BlockBackend *blk, int64_t offset,
- int64_t bytes, void *buf,
- BdrvRequestFlags flags)
-{
- QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
-
- assert(bytes <= SIZE_MAX);
-
- return blk_co_pwritev(blk, offset, bytes, &qiov, flags);
-}
-
-int blk_pwrite_zeroes(BlockBackend *blk, int64_t offset,
- int64_t bytes, BdrvRequestFlags flags);
-BlockAIOCB *blk_aio_pwrite_zeroes(BlockBackend *blk, int64_t offset,
- int64_t bytes, BdrvRequestFlags flags,
- BlockCompletionFunc *cb, void *opaque);
-int blk_make_zero(BlockBackend *blk, BdrvRequestFlags flags);
-int blk_pread(BlockBackend *blk, int64_t offset, void *buf, int bytes);
-int blk_pwrite(BlockBackend *blk, int64_t offset, const void *buf, int bytes,
- BdrvRequestFlags flags);
-int64_t blk_getlength(BlockBackend *blk);
-void blk_get_geometry(BlockBackend *blk, uint64_t *nb_sectors_ptr);
-int64_t blk_nb_sectors(BlockBackend *blk);
-BlockAIOCB *blk_aio_preadv(BlockBackend *blk, int64_t offset,
- QEMUIOVector *qiov, BdrvRequestFlags flags,
- BlockCompletionFunc *cb, void *opaque);
-BlockAIOCB *blk_aio_pwritev(BlockBackend *blk, int64_t offset,
- QEMUIOVector *qiov, BdrvRequestFlags flags,
- BlockCompletionFunc *cb, void *opaque);
-BlockAIOCB *blk_aio_flush(BlockBackend *blk,
- BlockCompletionFunc *cb, void *opaque);
-BlockAIOCB *blk_aio_pdiscard(BlockBackend *blk, int64_t offset, int64_t bytes,
- BlockCompletionFunc *cb, void *opaque);
-void blk_aio_cancel(BlockAIOCB *acb);
-void blk_aio_cancel_async(BlockAIOCB *acb);
-int blk_ioctl(BlockBackend *blk, unsigned long int req, void *buf);
-BlockAIOCB *blk_aio_ioctl(BlockBackend *blk, unsigned long int req, void *buf,
- BlockCompletionFunc *cb, void *opaque);
-int coroutine_fn blk_co_pdiscard(BlockBackend *blk, int64_t offset,
- int64_t bytes);
-int coroutine_fn blk_co_flush(BlockBackend *blk);
-int blk_flush(BlockBackend *blk);
-int blk_commit_all(void);
-void blk_inc_in_flight(BlockBackend *blk);
-void blk_dec_in_flight(BlockBackend *blk);
-void blk_drain(BlockBackend *blk);
-void blk_drain_all(void);
-void blk_set_on_error(BlockBackend *blk, BlockdevOnError on_read_error,
- BlockdevOnError on_write_error);
-BlockdevOnError blk_get_on_error(BlockBackend *blk, bool is_read);
-BlockErrorAction blk_get_error_action(BlockBackend *blk, bool is_read,
- int error);
-void blk_error_action(BlockBackend *blk, BlockErrorAction action,
- bool is_read, int error);
-bool blk_supports_write_perm(BlockBackend *blk);
-bool blk_is_writable(BlockBackend *blk);
-bool blk_is_sg(BlockBackend *blk);
-bool blk_enable_write_cache(BlockBackend *blk);
-void blk_set_enable_write_cache(BlockBackend *blk, bool wce);
-void blk_invalidate_cache(BlockBackend *blk, Error **errp);
-bool blk_is_inserted(BlockBackend *blk);
-bool blk_is_available(BlockBackend *blk);
-void blk_lock_medium(BlockBackend *blk, bool locked);
-void blk_eject(BlockBackend *blk, bool eject_flag);
-int blk_get_flags(BlockBackend *blk);
-uint32_t blk_get_request_alignment(BlockBackend *blk);
-uint32_t blk_get_max_transfer(BlockBackend *blk);
-uint64_t blk_get_max_hw_transfer(BlockBackend *blk);
-int blk_get_max_iov(BlockBackend *blk);
-int blk_get_max_hw_iov(BlockBackend *blk);
-void blk_set_guest_block_size(BlockBackend *blk, int align);
-void *blk_try_blockalign(BlockBackend *blk, size_t size);
-void *blk_blockalign(BlockBackend *blk, size_t size);
-bool blk_op_is_blocked(BlockBackend *blk, BlockOpType op, Error **errp);
-void blk_op_unblock(BlockBackend *blk, BlockOpType op, Error *reason);
-void blk_op_block_all(BlockBackend *blk, Error *reason);
-void blk_op_unblock_all(BlockBackend *blk, Error *reason);
-AioContext *blk_get_aio_context(BlockBackend *blk);
-int blk_set_aio_context(BlockBackend *blk, AioContext *new_context,
- Error **errp);
-void blk_add_aio_context_notifier(BlockBackend *blk,
- void (*attached_aio_context)(AioContext *new_context, void *opaque),
- void (*detach_aio_context)(void *opaque), void *opaque);
-void blk_remove_aio_context_notifier(BlockBackend *blk,
- void (*attached_aio_context)(AioContext *,
- void *),
- void (*detach_aio_context)(void *),
- void *opaque);
-void blk_add_remove_bs_notifier(BlockBackend *blk, Notifier *notify);
-void blk_add_insert_bs_notifier(BlockBackend *blk, Notifier *notify);
-void blk_io_plug(BlockBackend *blk);
-void blk_io_unplug(BlockBackend *blk);
-BlockAcctStats *blk_get_stats(BlockBackend *blk);
-BlockBackendRootState *blk_get_root_state(BlockBackend *blk);
-void blk_update_root_state(BlockBackend *blk);
-bool blk_get_detect_zeroes_from_root_state(BlockBackend *blk);
-int blk_get_open_flags_from_root_state(BlockBackend *blk);
-
-void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk,
- BlockCompletionFunc *cb, void *opaque);
-int coroutine_fn blk_co_pwrite_zeroes(BlockBackend *blk, int64_t offset,
- int64_t bytes, BdrvRequestFlags flags);
-int blk_pwrite_compressed(BlockBackend *blk, int64_t offset, const void *buf,
- int64_t bytes);
-int blk_truncate(BlockBackend *blk, int64_t offset, bool exact,
- PreallocMode prealloc, BdrvRequestFlags flags, Error **errp);
-int blk_pdiscard(BlockBackend *blk, int64_t offset, int64_t bytes);
-int blk_save_vmstate(BlockBackend *blk, const uint8_t *buf,
- int64_t pos, int size);
-int blk_load_vmstate(BlockBackend *blk, uint8_t *buf, int64_t pos, int size);
-int blk_probe_blocksizes(BlockBackend *blk, BlockSizes *bsz);
-int blk_probe_geometry(BlockBackend *blk, HDGeometry *geo);
-BlockAIOCB *blk_abort_aio_request(BlockBackend *blk,
- BlockCompletionFunc *cb,
- void *opaque, int ret);
-
-void blk_set_io_limits(BlockBackend *blk, ThrottleConfig *cfg);
-void blk_io_limits_disable(BlockBackend *blk);
-void blk_io_limits_enable(BlockBackend *blk, const char *group);
-void blk_io_limits_update_group(BlockBackend *blk, const char *group);
-void blk_set_force_allow_inactivate(BlockBackend *blk);
-
-void blk_register_buf(BlockBackend *blk, void *host, size_t size);
-void blk_unregister_buf(BlockBackend *blk, void *host);
-
-int coroutine_fn blk_co_copy_range(BlockBackend *blk_in, int64_t off_in,
- BlockBackend *blk_out, int64_t off_out,
- int64_t bytes, BdrvRequestFlags read_flags,
- BdrvRequestFlags write_flags);
-
-const BdrvChild *blk_root(BlockBackend *blk);
-
-int blk_make_empty(BlockBackend *blk, Error **errp);
+/* DO NOT ADD ANYTHING IN HERE. USE ONE OF THE HEADERS INCLUDED ABOVE */
#endif
diff --git a/block/block-backend.c b/block/block-backend.c
index 12ef80ea17..1f0bda578e 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -79,6 +79,7 @@ struct BlockBackend {
bool allow_aio_context_change;
bool allow_write_beyond_eof;
+ /* Protected by BQL lock */
NotifierList remove_bs_notifiers, insert_bs_notifiers;
QLIST_HEAD(, BlockBackendAioNotifier) aio_notifiers;
@@ -111,12 +112,14 @@ static const AIOCBInfo block_backend_aiocb_info = {
static void drive_info_del(DriveInfo *dinfo);
static BlockBackend *bdrv_first_blk(BlockDriverState *bs);
-/* All BlockBackends */
+/* All BlockBackends. Protected by BQL lock. */
static QTAILQ_HEAD(, BlockBackend) block_backends =
QTAILQ_HEAD_INITIALIZER(block_backends);
-/* All BlockBackends referenced by the monitor and which are iterated through by
- * blk_next() */
+/*
+ * All BlockBackends referenced by the monitor and which are iterated through by
+ * blk_next(). Protected by BQL lock.
+ */
static QTAILQ_HEAD(, BlockBackend) monitor_block_backends =
QTAILQ_HEAD_INITIALIZER(monitor_block_backends);
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 05/31] block-backend: special comments for blk_set/get_perm due to fuse
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (3 preceding siblings ...)
2021-11-24 6:43 ` [PATCH v5 04/31] include/sysemu/block-backend: split header into I/O and global state (GS) API Emanuele Giuseppe Esposito
@ 2021-11-24 6:43 ` Emanuele Giuseppe Esposito
2021-12-10 14:38 ` Hanna Reitz
2021-11-24 6:43 ` [PATCH v5 06/31] block/block-backend.c: assertions for block-backend Emanuele Giuseppe Esposito
` (26 subsequent siblings)
31 siblings, 1 reply; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:43 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
Fuse logic can be classified as I/O, so there is no BQL held
during its execution. And yet, it uses blk_{get/set}_perm
functions, that are classified as BQL and clearly require
the BQL lock. Since there is no easy solution for this,
add a couple of TODOs and FIXME in the relevant sections of the
code.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
block/block-backend.c | 10 ++++++++++
block/export/fuse.c | 16 ++++++++++++++--
2 files changed, 24 insertions(+), 2 deletions(-)
diff --git a/block/block-backend.c b/block/block-backend.c
index 1f0bda578e..7a4b50a8f0 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -888,6 +888,11 @@ int blk_set_perm(BlockBackend *blk, uint64_t perm, uint64_t shared_perm,
Error **errp)
{
int ret;
+ /*
+ * FIXME: blk_{get/set}_perm should be always called under
+ * BQL, but it is not the case right now (see block/export/fuse.c)
+ */
+ /* assert(qemu_in_main_thread()); */
if (blk->root && !blk->disable_perm) {
ret = bdrv_child_try_set_perm(blk->root, perm, shared_perm, errp);
@@ -904,6 +909,11 @@ int blk_set_perm(BlockBackend *blk, uint64_t perm, uint64_t shared_perm,
void blk_get_perm(BlockBackend *blk, uint64_t *perm, uint64_t *shared_perm)
{
+ /*
+ * FIXME: blk_{get/set}_perm should be always called under
+ * BQL, but it is not the case right now (see block/export/fuse.c)
+ */
+ /* assert(qemu_in_main_thread()); */
*perm = blk->perm;
*shared_perm = blk->shared_perm;
}
diff --git a/block/export/fuse.c b/block/export/fuse.c
index 823c126d23..7ceb8d783b 100644
--- a/block/export/fuse.c
+++ b/block/export/fuse.c
@@ -89,7 +89,10 @@ static int fuse_export_create(BlockExport *blk_exp,
/* For growable exports, take the RESIZE permission */
if (args->growable) {
uint64_t blk_perm, blk_shared_perm;
-
+ /*
+ * FIXME: blk_{get/set}_perm should not be here, as permissions
+ * should be modified only under BQL and here we are not!
+ */
blk_get_perm(exp->common.blk, &blk_perm, &blk_shared_perm);
ret = blk_set_perm(exp->common.blk, blk_perm | BLK_PERM_RESIZE,
@@ -400,6 +403,11 @@ static int fuse_do_truncate(const FuseExport *exp, int64_t size,
/* Growable exports have a permanent RESIZE permission */
if (!exp->growable) {
+
+ /*
+ * FIXME: blk_{get/set}_perm should not be here, as permissions
+ * should be modified only under BQL and here we are not!
+ */
blk_get_perm(exp->common.blk, &blk_perm, &blk_shared_perm);
ret = blk_set_perm(exp->common.blk, blk_perm | BLK_PERM_RESIZE,
@@ -413,7 +421,11 @@ static int fuse_do_truncate(const FuseExport *exp, int64_t size,
truncate_flags, NULL);
if (!exp->growable) {
- /* Must succeed, because we are only giving up the RESIZE permission */
+ /*
+ * Must succeed, because we are only giving up the RESIZE permission.
+ * FIXME: blk_{get/set}_perm should not be here, as permissions
+ * should be modified only under BQL and here we are not!
+ */
blk_set_perm(exp->common.blk, blk_perm, blk_shared_perm, &error_abort);
}
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 06/31] block/block-backend.c: assertions for block-backend
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (4 preceding siblings ...)
2021-11-24 6:43 ` [PATCH v5 05/31] block-backend: special comments for blk_set/get_perm due to fuse Emanuele Giuseppe Esposito
@ 2021-11-24 6:43 ` Emanuele Giuseppe Esposito
2021-12-10 15:37 ` Hanna Reitz
2021-11-24 6:43 ` [PATCH v5 07/31] include/block/block_int: split header into I/O and global state API Emanuele Giuseppe Esposito
` (25 subsequent siblings)
31 siblings, 1 reply; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:43 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
All the global state (GS) API functions will check that
qemu_in_main_thread() returns true. If not, it means
that the safety of BQL cannot be guaranteed, and
they need to be moved to I/O.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
block/block-backend.c | 83 ++++++++++++++++++++++++++++++++++++++++++
softmmu/qdev-monitor.c | 2 +
2 files changed, 85 insertions(+)
diff --git a/block/block-backend.c b/block/block-backend.c
index 7a4b50a8f0..11131ca68c 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -228,6 +228,7 @@ static void blk_root_activate(BdrvChild *child, Error **errp)
void blk_set_force_allow_inactivate(BlockBackend *blk)
{
+ assert(qemu_in_main_thread());
blk->force_allow_inactivate = true;
}
@@ -346,6 +347,8 @@ BlockBackend *blk_new(AioContext *ctx, uint64_t perm, uint64_t shared_perm)
{
BlockBackend *blk;
+ assert(qemu_in_main_thread());
+
blk = g_new0(BlockBackend, 1);
blk->refcnt = 1;
blk->ctx = ctx;
@@ -383,6 +386,8 @@ BlockBackend *blk_new_with_bs(BlockDriverState *bs, uint64_t perm,
{
BlockBackend *blk = blk_new(bdrv_get_aio_context(bs), perm, shared_perm);
+ assert(qemu_in_main_thread());
+
if (blk_insert_bs(blk, bs, errp) < 0) {
blk_unref(blk);
return NULL;
@@ -411,6 +416,8 @@ BlockBackend *blk_new_open(const char *filename, const char *reference,
uint64_t perm = 0;
uint64_t shared = BLK_PERM_ALL;
+ assert(qemu_in_main_thread());
+
/*
* blk_new_open() is mainly used in .bdrv_create implementations and the
* tools where sharing isn't a major concern because the BDS stays private
@@ -488,6 +495,7 @@ static void drive_info_del(DriveInfo *dinfo)
int blk_get_refcnt(BlockBackend *blk)
{
+ assert(qemu_in_main_thread());
return blk ? blk->refcnt : 0;
}
@@ -498,6 +506,7 @@ int blk_get_refcnt(BlockBackend *blk)
void blk_ref(BlockBackend *blk)
{
assert(blk->refcnt > 0);
+ assert(qemu_in_main_thread());
blk->refcnt++;
}
@@ -508,6 +517,7 @@ void blk_ref(BlockBackend *blk)
*/
void blk_unref(BlockBackend *blk)
{
+ assert(qemu_in_main_thread());
if (blk) {
assert(blk->refcnt > 0);
if (blk->refcnt > 1) {
@@ -528,6 +538,7 @@ void blk_unref(BlockBackend *blk)
*/
BlockBackend *blk_all_next(BlockBackend *blk)
{
+ assert(qemu_in_main_thread());
return blk ? QTAILQ_NEXT(blk, link)
: QTAILQ_FIRST(&block_backends);
}
@@ -536,6 +547,8 @@ void blk_remove_all_bs(void)
{
BlockBackend *blk = NULL;
+ assert(qemu_in_main_thread());
+
while ((blk = blk_all_next(blk)) != NULL) {
AioContext *ctx = blk_get_aio_context(blk);
@@ -559,6 +572,7 @@ void blk_remove_all_bs(void)
*/
BlockBackend *blk_next(BlockBackend *blk)
{
+ assert(qemu_in_main_thread());
return blk ? QTAILQ_NEXT(blk, monitor_link)
: QTAILQ_FIRST(&monitor_block_backends);
}
@@ -625,6 +639,7 @@ static void bdrv_next_reset(BdrvNextIterator *it)
BlockDriverState *bdrv_first(BdrvNextIterator *it)
{
+ assert(qemu_in_main_thread());
bdrv_next_reset(it);
return bdrv_next(it);
}
@@ -662,6 +677,7 @@ bool monitor_add_blk(BlockBackend *blk, const char *name, Error **errp)
{
assert(!blk->name);
assert(name && name[0]);
+ assert(qemu_in_main_thread());
if (!id_wellformed(name)) {
error_setg(errp, "Invalid device name");
@@ -689,6 +705,8 @@ bool monitor_add_blk(BlockBackend *blk, const char *name, Error **errp)
*/
void monitor_remove_blk(BlockBackend *blk)
{
+ assert(qemu_in_main_thread());
+
if (!blk->name) {
return;
}
@@ -715,6 +733,7 @@ BlockBackend *blk_by_name(const char *name)
{
BlockBackend *blk = NULL;
+ assert(qemu_in_main_thread());
assert(name);
while ((blk = blk_next(blk)) != NULL) {
if (!strcmp(name, blk->name)) {
@@ -749,6 +768,7 @@ static BlockBackend *bdrv_first_blk(BlockDriverState *bs)
*/
bool bdrv_has_blk(BlockDriverState *bs)
{
+ assert(qemu_in_main_thread());
return bdrv_first_blk(bs) != NULL;
}
@@ -759,6 +779,7 @@ bool bdrv_is_root_node(BlockDriverState *bs)
{
BdrvChild *c;
+ assert(qemu_in_main_thread());
QLIST_FOREACH(c, &bs->parents, next_parent) {
if (c->klass != &child_root) {
return false;
@@ -808,6 +829,7 @@ BlockBackend *blk_by_legacy_dinfo(DriveInfo *dinfo)
*/
BlockBackendPublic *blk_get_public(BlockBackend *blk)
{
+ assert(qemu_in_main_thread());
return &blk->public;
}
@@ -816,6 +838,7 @@ BlockBackendPublic *blk_get_public(BlockBackend *blk)
*/
BlockBackend *blk_by_public(BlockBackendPublic *public)
{
+ assert(qemu_in_main_thread());
return container_of(public, BlockBackend, public);
}
@@ -828,6 +851,8 @@ void blk_remove_bs(BlockBackend *blk)
BlockDriverState *bs;
BdrvChild *root;
+ assert(qemu_in_main_thread());
+
notifier_list_notify(&blk->remove_bs_notifiers, blk);
if (tgm->throttle_state) {
bs = blk_bs(blk);
@@ -855,6 +880,7 @@ void blk_remove_bs(BlockBackend *blk)
int blk_insert_bs(BlockBackend *blk, BlockDriverState *bs, Error **errp)
{
ThrottleGroupMember *tgm = &blk->public.throttle_group_member;
+ assert(qemu_in_main_thread());
bdrv_ref(bs);
blk->root = bdrv_root_attach_child(bs, "root", &child_root,
BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY,
@@ -878,6 +904,7 @@ int blk_insert_bs(BlockBackend *blk, BlockDriverState *bs, Error **errp)
*/
int blk_replace_bs(BlockBackend *blk, BlockDriverState *new_bs, Error **errp)
{
+ assert(qemu_in_main_thread());
return bdrv_replace_child_bs(blk->root, new_bs, errp);
}
@@ -924,6 +951,7 @@ void blk_get_perm(BlockBackend *blk, uint64_t *perm, uint64_t *shared_perm)
*/
int blk_attach_dev(BlockBackend *blk, DeviceState *dev)
{
+ assert(qemu_in_main_thread());
if (blk->dev) {
return -EBUSY;
}
@@ -949,6 +977,7 @@ int blk_attach_dev(BlockBackend *blk, DeviceState *dev)
void blk_detach_dev(BlockBackend *blk, DeviceState *dev)
{
assert(blk->dev == dev);
+ assert(qemu_in_main_thread());
blk->dev = NULL;
blk->dev_ops = NULL;
blk->dev_opaque = NULL;
@@ -962,6 +991,7 @@ void blk_detach_dev(BlockBackend *blk, DeviceState *dev)
*/
DeviceState *blk_get_attached_dev(BlockBackend *blk)
{
+ assert(qemu_in_main_thread());
return blk->dev;
}
@@ -970,6 +1000,7 @@ DeviceState *blk_get_attached_dev(BlockBackend *blk)
char *blk_get_attached_dev_id(BlockBackend *blk)
{
DeviceState *dev = blk->dev;
+ assert(qemu_in_main_thread());
if (!dev) {
return g_strdup("");
@@ -990,6 +1021,8 @@ BlockBackend *blk_by_dev(void *dev)
{
BlockBackend *blk = NULL;
+ assert(qemu_in_main_thread());
+
assert(dev != NULL);
while ((blk = blk_all_next(blk)) != NULL) {
if (blk->dev == dev) {
@@ -1007,6 +1040,7 @@ BlockBackend *blk_by_dev(void *dev)
void blk_set_dev_ops(BlockBackend *blk, const BlockDevOps *ops,
void *opaque)
{
+ assert(qemu_in_main_thread());
blk->dev_ops = ops;
blk->dev_opaque = opaque;
@@ -1028,6 +1062,7 @@ void blk_set_dev_ops(BlockBackend *blk, const BlockDevOps *ops,
*/
void blk_dev_change_media_cb(BlockBackend *blk, bool load, Error **errp)
{
+ assert(qemu_in_main_thread());
if (blk->dev_ops && blk->dev_ops->change_media_cb) {
bool tray_was_open, tray_is_open;
Error *local_err = NULL;
@@ -1119,6 +1154,7 @@ static void blk_root_resize(BdrvChild *child)
void blk_iostatus_enable(BlockBackend *blk)
{
+ assert(qemu_in_main_thread());
blk->iostatus_enabled = true;
blk->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
}
@@ -1127,6 +1163,7 @@ void blk_iostatus_enable(BlockBackend *blk)
* enables it _and_ the VM is configured to stop on errors */
bool blk_iostatus_is_enabled(const BlockBackend *blk)
{
+ assert(qemu_in_main_thread());
return (blk->iostatus_enabled &&
(blk->on_write_error == BLOCKDEV_ON_ERROR_ENOSPC ||
blk->on_write_error == BLOCKDEV_ON_ERROR_STOP ||
@@ -1135,16 +1172,19 @@ bool blk_iostatus_is_enabled(const BlockBackend *blk)
BlockDeviceIoStatus blk_iostatus(const BlockBackend *blk)
{
+ assert(qemu_in_main_thread());
return blk->iostatus;
}
void blk_iostatus_disable(BlockBackend *blk)
{
+ assert(qemu_in_main_thread());
blk->iostatus_enabled = false;
}
void blk_iostatus_reset(BlockBackend *blk)
{
+ assert(qemu_in_main_thread());
if (blk_iostatus_is_enabled(blk)) {
blk->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
}
@@ -1152,6 +1192,7 @@ void blk_iostatus_reset(BlockBackend *blk)
void blk_iostatus_set_err(BlockBackend *blk, int error)
{
+ assert(qemu_in_main_thread());
assert(blk_iostatus_is_enabled(blk));
if (blk->iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
blk->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE :
@@ -1351,6 +1392,7 @@ int blk_pwrite_zeroes(BlockBackend *blk, int64_t offset,
int blk_make_zero(BlockBackend *blk, BdrvRequestFlags flags)
{
+ assert(qemu_in_main_thread());
return bdrv_make_zero(blk->root, flags);
}
@@ -1560,6 +1602,7 @@ BlockAIOCB *blk_aio_pwritev(BlockBackend *blk, int64_t offset,
void blk_aio_cancel(BlockAIOCB *acb)
{
+ assert(qemu_in_main_thread());
bdrv_aio_cancel(acb);
}
@@ -1584,6 +1627,7 @@ blk_co_do_ioctl(BlockBackend *blk, unsigned long int req, void *buf)
int blk_ioctl(BlockBackend *blk, unsigned long int req, void *buf)
{
int ret;
+ assert(qemu_in_main_thread());
blk_inc_in_flight(blk);
ret = blk_do_ioctl(blk, req, buf);
@@ -1734,6 +1778,8 @@ void blk_drain_all(void)
{
BlockBackend *blk = NULL;
+ assert(qemu_in_main_thread());
+
bdrv_drain_all_begin();
while ((blk = blk_all_next(blk)) != NULL) {
@@ -1753,6 +1799,7 @@ void blk_drain_all(void)
void blk_set_on_error(BlockBackend *blk, BlockdevOnError on_read_error,
BlockdevOnError on_write_error)
{
+ assert(qemu_in_main_thread());
blk->on_read_error = on_read_error;
blk->on_write_error = on_write_error;
}
@@ -1836,6 +1883,7 @@ void blk_error_action(BlockBackend *blk, BlockErrorAction action,
bool blk_supports_write_perm(BlockBackend *blk)
{
BlockDriverState *bs = blk_bs(blk);
+ assert(qemu_in_main_thread());
if (bs) {
return !bdrv_is_read_only(bs);
@@ -1856,6 +1904,7 @@ bool blk_is_writable(BlockBackend *blk)
bool blk_is_sg(BlockBackend *blk)
{
BlockDriverState *bs = blk_bs(blk);
+ assert(qemu_in_main_thread());
if (!bs) {
return false;
@@ -1866,11 +1915,13 @@ bool blk_is_sg(BlockBackend *blk)
bool blk_enable_write_cache(BlockBackend *blk)
{
+ assert(qemu_in_main_thread());
return blk->enable_write_cache;
}
void blk_set_enable_write_cache(BlockBackend *blk, bool wce)
{
+ assert(qemu_in_main_thread());
blk->enable_write_cache = wce;
}
@@ -1901,6 +1952,7 @@ bool blk_is_available(BlockBackend *blk)
void blk_lock_medium(BlockBackend *blk, bool locked)
{
BlockDriverState *bs = blk_bs(blk);
+ assert(qemu_in_main_thread());
if (bs) {
bdrv_lock_medium(bs, locked);
@@ -1910,6 +1962,8 @@ void blk_lock_medium(BlockBackend *blk, bool locked)
void blk_eject(BlockBackend *blk, bool eject_flag)
{
BlockDriverState *bs = blk_bs(blk);
+ assert(qemu_in_main_thread());
+
char *id;
if (bs) {
@@ -1927,6 +1981,7 @@ void blk_eject(BlockBackend *blk, bool eject_flag)
int blk_get_flags(BlockBackend *blk)
{
BlockDriverState *bs = blk_bs(blk);
+ assert(qemu_in_main_thread());
if (bs) {
return bdrv_get_flags(bs);
@@ -1980,6 +2035,7 @@ int blk_get_max_iov(BlockBackend *blk)
void blk_set_guest_block_size(BlockBackend *blk, int align)
{
+ assert(qemu_in_main_thread());
blk->guest_block_size = align;
}
@@ -1996,6 +2052,7 @@ void *blk_blockalign(BlockBackend *blk, size_t size)
bool blk_op_is_blocked(BlockBackend *blk, BlockOpType op, Error **errp)
{
BlockDriverState *bs = blk_bs(blk);
+ assert(qemu_in_main_thread());
if (!bs) {
return false;
@@ -2007,6 +2064,7 @@ bool blk_op_is_blocked(BlockBackend *blk, BlockOpType op, Error **errp)
void blk_op_unblock(BlockBackend *blk, BlockOpType op, Error *reason)
{
BlockDriverState *bs = blk_bs(blk);
+ assert(qemu_in_main_thread());
if (bs) {
bdrv_op_unblock(bs, op, reason);
@@ -2016,6 +2074,7 @@ void blk_op_unblock(BlockBackend *blk, BlockOpType op, Error *reason)
void blk_op_block_all(BlockBackend *blk, Error *reason)
{
BlockDriverState *bs = blk_bs(blk);
+ assert(qemu_in_main_thread());
if (bs) {
bdrv_op_block_all(bs, reason);
@@ -2025,6 +2084,7 @@ void blk_op_block_all(BlockBackend *blk, Error *reason)
void blk_op_unblock_all(BlockBackend *blk, Error *reason)
{
BlockDriverState *bs = blk_bs(blk);
+ assert(qemu_in_main_thread());
if (bs) {
bdrv_op_unblock_all(bs, reason);
@@ -2079,6 +2139,7 @@ static int blk_do_set_aio_context(BlockBackend *blk, AioContext *new_context,
int blk_set_aio_context(BlockBackend *blk, AioContext *new_context,
Error **errp)
{
+ assert(qemu_in_main_thread());
return blk_do_set_aio_context(blk, new_context, true, errp);
}
@@ -2115,6 +2176,7 @@ void blk_add_aio_context_notifier(BlockBackend *blk,
{
BlockBackendAioNotifier *notifier;
BlockDriverState *bs = blk_bs(blk);
+ assert(qemu_in_main_thread());
notifier = g_new(BlockBackendAioNotifier, 1);
notifier->attached_aio_context = attached_aio_context;
@@ -2137,6 +2199,8 @@ void blk_remove_aio_context_notifier(BlockBackend *blk,
BlockBackendAioNotifier *notifier;
BlockDriverState *bs = blk_bs(blk);
+ assert(qemu_in_main_thread());
+
if (bs) {
bdrv_remove_aio_context_notifier(bs, attached_aio_context,
detach_aio_context, opaque);
@@ -2157,11 +2221,13 @@ void blk_remove_aio_context_notifier(BlockBackend *blk,
void blk_add_remove_bs_notifier(BlockBackend *blk, Notifier *notify)
{
+ assert(qemu_in_main_thread());
notifier_list_add(&blk->remove_bs_notifiers, notify);
}
void blk_add_insert_bs_notifier(BlockBackend *blk, Notifier *notify)
{
+ assert(qemu_in_main_thread());
notifier_list_add(&blk->insert_bs_notifiers, notify);
}
@@ -2224,6 +2290,7 @@ int blk_save_vmstate(BlockBackend *blk, const uint8_t *buf,
int64_t pos, int size)
{
int ret;
+ assert(qemu_in_main_thread());
if (!blk_is_available(blk)) {
return -ENOMEDIUM;
@@ -2243,6 +2310,7 @@ int blk_save_vmstate(BlockBackend *blk, const uint8_t *buf,
int blk_load_vmstate(BlockBackend *blk, uint8_t *buf, int64_t pos, int size)
{
+ assert(qemu_in_main_thread());
if (!blk_is_available(blk)) {
return -ENOMEDIUM;
}
@@ -2252,6 +2320,7 @@ int blk_load_vmstate(BlockBackend *blk, uint8_t *buf, int64_t pos, int size)
int blk_probe_blocksizes(BlockBackend *blk, BlockSizes *bsz)
{
+ assert(qemu_in_main_thread());
if (!blk_is_available(blk)) {
return -ENOMEDIUM;
}
@@ -2261,6 +2330,7 @@ int blk_probe_blocksizes(BlockBackend *blk, BlockSizes *bsz)
int blk_probe_geometry(BlockBackend *blk, HDGeometry *geo)
{
+ assert(qemu_in_main_thread());
if (!blk_is_available(blk)) {
return -ENOMEDIUM;
}
@@ -2274,6 +2344,7 @@ int blk_probe_geometry(BlockBackend *blk, HDGeometry *geo)
*/
void blk_update_root_state(BlockBackend *blk)
{
+ assert(qemu_in_main_thread());
assert(blk->root);
blk->root_state.open_flags = blk->root->bs->open_flags;
@@ -2286,6 +2357,7 @@ void blk_update_root_state(BlockBackend *blk)
*/
bool blk_get_detect_zeroes_from_root_state(BlockBackend *blk)
{
+ assert(qemu_in_main_thread());
return blk->root_state.detect_zeroes;
}
@@ -2295,17 +2367,20 @@ bool blk_get_detect_zeroes_from_root_state(BlockBackend *blk)
*/
int blk_get_open_flags_from_root_state(BlockBackend *blk)
{
+ assert(qemu_in_main_thread());
return blk->root_state.open_flags;
}
BlockBackendRootState *blk_get_root_state(BlockBackend *blk)
{
+ assert(qemu_in_main_thread());
return &blk->root_state;
}
int blk_commit_all(void)
{
BlockBackend *blk = NULL;
+ assert(qemu_in_main_thread());
while ((blk = blk_all_next(blk)) != NULL) {
AioContext *aio_context = blk_get_aio_context(blk);
@@ -2330,6 +2405,7 @@ int blk_commit_all(void)
/* throttling disk I/O limits */
void blk_set_io_limits(BlockBackend *blk, ThrottleConfig *cfg)
{
+ assert(qemu_in_main_thread());
throttle_group_config(&blk->public.throttle_group_member, cfg);
}
@@ -2338,6 +2414,7 @@ void blk_io_limits_disable(BlockBackend *blk)
BlockDriverState *bs = blk_bs(blk);
ThrottleGroupMember *tgm = &blk->public.throttle_group_member;
assert(tgm->throttle_state);
+ assert(qemu_in_main_thread());
if (bs) {
bdrv_drained_begin(bs);
}
@@ -2351,12 +2428,14 @@ void blk_io_limits_disable(BlockBackend *blk)
void blk_io_limits_enable(BlockBackend *blk, const char *group)
{
assert(!blk->public.throttle_group_member.throttle_state);
+ assert(qemu_in_main_thread());
throttle_group_register_tgm(&blk->public.throttle_group_member,
group, blk_get_aio_context(blk));
}
void blk_io_limits_update_group(BlockBackend *blk, const char *group)
{
+ assert(qemu_in_main_thread());
/* this BB is not part of any group */
if (!blk->public.throttle_group_member.throttle_state) {
return;
@@ -2424,11 +2503,13 @@ static void blk_root_drained_end(BdrvChild *child, int *drained_end_counter)
void blk_register_buf(BlockBackend *blk, void *host, size_t size)
{
+ assert(qemu_in_main_thread());
bdrv_register_buf(blk_bs(blk), host, size);
}
void blk_unregister_buf(BlockBackend *blk, void *host)
{
+ assert(qemu_in_main_thread());
bdrv_unregister_buf(blk_bs(blk), host);
}
@@ -2453,11 +2534,13 @@ int coroutine_fn blk_co_copy_range(BlockBackend *blk_in, int64_t off_in,
const BdrvChild *blk_root(BlockBackend *blk)
{
+ assert(qemu_in_main_thread());
return blk->root;
}
int blk_make_empty(BlockBackend *blk, Error **errp)
{
+ assert(qemu_in_main_thread());
if (!blk_is_available(blk)) {
error_setg(errp, "No medium inserted");
return -ENOMEDIUM;
diff --git a/softmmu/qdev-monitor.c b/softmmu/qdev-monitor.c
index 01ec420e61..62866d08c4 100644
--- a/softmmu/qdev-monitor.c
+++ b/softmmu/qdev-monitor.c
@@ -969,6 +969,8 @@ BlockBackend *blk_by_qdev_id(const char *id, Error **errp)
DeviceState *dev;
BlockBackend *blk;
+ assert(qemu_in_main_thread());
+
dev = find_device_state(id, errp);
if (dev == NULL) {
return NULL;
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 07/31] include/block/block_int: split header into I/O and global state API
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (5 preceding siblings ...)
2021-11-24 6:43 ` [PATCH v5 06/31] block/block-backend.c: assertions for block-backend Emanuele Giuseppe Esposito
@ 2021-11-24 6:43 ` Emanuele Giuseppe Esposito
2021-11-24 6:43 ` [PATCH v5 08/31] assertions for block_int " Emanuele Giuseppe Esposito
` (24 subsequent siblings)
31 siblings, 0 replies; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:43 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
Similarly to the previous patch, split block_int.h
in block_int-io.h and block_int-global-state.h
block_int-common.h contains the structures shared between
the two headers, and the functions that can't be categorized as
I/O or global state.
Assertions are added in the next patch.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
include/block/block_int-common.h | 1161 +++++++++++++++++++
include/block/block_int-global-state.h | 315 +++++
include/block/block_int-io.h | 167 +++
include/block/block_int.h | 1475 +-----------------------
blockdev.c | 5 +
5 files changed, 1651 insertions(+), 1472 deletions(-)
create mode 100644 include/block/block_int-common.h
create mode 100644 include/block/block_int-global-state.h
create mode 100644 include/block/block_int-io.h
diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h
new file mode 100644
index 0000000000..70534f94ae
--- /dev/null
+++ b/include/block/block_int-common.h
@@ -0,0 +1,1161 @@
+/*
+ * QEMU System Emulator block driver
+ *
+ * Copyright (c) 2003 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#ifndef BLOCK_INT_COMMON_H
+#define BLOCK_INT_COMMON_H
+
+#include "block/accounting.h"
+#include "block/block.h"
+#include "block/aio-wait.h"
+#include "qemu/queue.h"
+#include "qemu/coroutine.h"
+#include "qemu/stats64.h"
+#include "qemu/timer.h"
+#include "qemu/hbitmap.h"
+#include "block/snapshot.h"
+#include "qemu/throttle.h"
+#include "qemu/rcu.h"
+
+#define BLOCK_FLAG_LAZY_REFCOUNTS 8
+
+#define BLOCK_OPT_SIZE "size"
+#define BLOCK_OPT_ENCRYPT "encryption"
+#define BLOCK_OPT_ENCRYPT_FORMAT "encrypt.format"
+#define BLOCK_OPT_COMPAT6 "compat6"
+#define BLOCK_OPT_HWVERSION "hwversion"
+#define BLOCK_OPT_BACKING_FILE "backing_file"
+#define BLOCK_OPT_BACKING_FMT "backing_fmt"
+#define BLOCK_OPT_CLUSTER_SIZE "cluster_size"
+#define BLOCK_OPT_TABLE_SIZE "table_size"
+#define BLOCK_OPT_PREALLOC "preallocation"
+#define BLOCK_OPT_SUBFMT "subformat"
+#define BLOCK_OPT_COMPAT_LEVEL "compat"
+#define BLOCK_OPT_LAZY_REFCOUNTS "lazy_refcounts"
+#define BLOCK_OPT_ADAPTER_TYPE "adapter_type"
+#define BLOCK_OPT_REDUNDANCY "redundancy"
+#define BLOCK_OPT_NOCOW "nocow"
+#define BLOCK_OPT_EXTENT_SIZE_HINT "extent_size_hint"
+#define BLOCK_OPT_OBJECT_SIZE "object_size"
+#define BLOCK_OPT_REFCOUNT_BITS "refcount_bits"
+#define BLOCK_OPT_DATA_FILE "data_file"
+#define BLOCK_OPT_DATA_FILE_RAW "data_file_raw"
+#define BLOCK_OPT_COMPRESSION_TYPE "compression_type"
+#define BLOCK_OPT_EXTL2 "extended_l2"
+
+#define BLOCK_PROBE_BUF_SIZE 512
+
+enum BdrvTrackedRequestType {
+ BDRV_TRACKED_READ,
+ BDRV_TRACKED_WRITE,
+ BDRV_TRACKED_DISCARD,
+ BDRV_TRACKED_TRUNCATE,
+};
+
+/*
+ * That is not quite good that BdrvTrackedRequest structure is public,
+ * as block/io.c is very careful about incoming offset/bytes being
+ * correct. Be sure to assert bdrv_check_request() succeeded after any
+ * modification of BdrvTrackedRequest object out of block/io.c
+ */
+typedef struct BdrvTrackedRequest {
+ BlockDriverState *bs;
+ int64_t offset;
+ int64_t bytes;
+ enum BdrvTrackedRequestType type;
+
+ bool serialising;
+ int64_t overlap_offset;
+ int64_t overlap_bytes;
+
+ QLIST_ENTRY(BdrvTrackedRequest) list;
+ Coroutine *co; /* owner, used for deadlock detection */
+ CoQueue wait_queue; /* coroutines blocked on this request */
+
+ struct BdrvTrackedRequest *waiting_for;
+} BdrvTrackedRequest;
+
+
+struct BlockDriver {
+ const char *format_name;
+ int instance_size;
+
+ /*
+ * Set to true if the BlockDriver is a block filter. Block filters pass
+ * certain callbacks that refer to data (see block.c) to their bs->file
+ * or bs->backing (whichever one exists) if the driver doesn't implement
+ * them. Drivers that do not wish to forward must implement them and return
+ * -ENOTSUP.
+ * Note that filters are not allowed to modify data.
+ *
+ * Filters generally cannot have more than a single filtered child,
+ * because the data they present must at all times be the same as
+ * that on their filtered child. That would be impossible to
+ * achieve for multiple filtered children.
+ * (And this filtered child must then be bs->file or bs->backing.)
+ */
+ bool is_filter;
+ /*
+ * Set to true if the BlockDriver is a format driver. Format nodes
+ * generally do not expect their children to be other format nodes
+ * (except for backing files), and so format probing is disabled
+ * on those children.
+ */
+ bool is_format;
+ /*
+ * Return true if @to_replace can be replaced by a BDS with the
+ * same data as @bs without it affecting @bs's behavior (that is,
+ * without it being visible to @bs's parents).
+ */
+ bool (*bdrv_recurse_can_replace)(BlockDriverState *bs,
+ BlockDriverState *to_replace);
+
+ int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
+ int (*bdrv_probe_device)(const char *filename);
+
+ /*
+ * Any driver implementing this callback is expected to be able to handle
+ * NULL file names in its .bdrv_open() implementation.
+ */
+ void (*bdrv_parse_filename)(const char *filename, QDict *options,
+ Error **errp);
+ /*
+ * Drivers not implementing bdrv_parse_filename nor bdrv_open should have
+ * this field set to true, except ones that are defined only by their
+ * child's bs.
+ * An example of the last type will be the quorum block driver.
+ */
+ bool bdrv_needs_filename;
+
+ /*
+ * Set if a driver can support backing files. This also implies the
+ * following semantics:
+ *
+ * - Return status 0 of .bdrv_co_block_status means that corresponding
+ * blocks are not allocated in this layer of backing-chain
+ * - For such (unallocated) blocks, read will:
+ * - fill buffer with zeros if there is no backing file
+ * - read from the backing file otherwise, where the block layer
+ * takes care of reading zeros beyond EOF if backing file is short
+ */
+ bool supports_backing;
+
+ /* For handling image reopen for split or non-split files */
+ int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state,
+ BlockReopenQueue *queue, Error **errp);
+ void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state);
+ void (*bdrv_reopen_commit_post)(BDRVReopenState *reopen_state);
+ void (*bdrv_reopen_abort)(BDRVReopenState *reopen_state);
+ void (*bdrv_join_options)(QDict *options, QDict *old_options);
+
+ int (*bdrv_open)(BlockDriverState *bs, QDict *options, int flags,
+ Error **errp);
+
+ /* Protocol drivers should implement this instead of bdrv_open */
+ int (*bdrv_file_open)(BlockDriverState *bs, QDict *options, int flags,
+ Error **errp);
+ void (*bdrv_close)(BlockDriverState *bs);
+
+
+ int coroutine_fn (*bdrv_co_create)(BlockdevCreateOptions *opts,
+ Error **errp);
+ int coroutine_fn (*bdrv_co_create_opts)(BlockDriver *drv,
+ const char *filename,
+ QemuOpts *opts,
+ Error **errp);
+
+ int coroutine_fn (*bdrv_co_amend)(BlockDriverState *bs,
+ BlockdevAmendOptions *opts,
+ bool force,
+ Error **errp);
+
+ int (*bdrv_amend_options)(BlockDriverState *bs,
+ QemuOpts *opts,
+ BlockDriverAmendStatusCB *status_cb,
+ void *cb_opaque,
+ bool force,
+ Error **errp);
+
+ int (*bdrv_make_empty)(BlockDriverState *bs);
+
+ /*
+ * Refreshes the bs->exact_filename field. If that is impossible,
+ * bs->exact_filename has to be left empty.
+ */
+ void (*bdrv_refresh_filename)(BlockDriverState *bs);
+
+ /*
+ * Gathers the open options for all children into @target.
+ * A simple format driver (without backing file support) might
+ * implement this function like this:
+ *
+ * QINCREF(bs->file->bs->full_open_options);
+ * qdict_put(target, "file", bs->file->bs->full_open_options);
+ *
+ * If not specified, the generic implementation will simply put
+ * all children's options under their respective name.
+ *
+ * @backing_overridden is true when bs->backing seems not to be
+ * the child that would result from opening bs->backing_file.
+ * Therefore, if it is true, the backing child's options should be
+ * gathered; otherwise, there is no need since the backing child
+ * is the one implied by the image header.
+ *
+ * Note that ideally this function would not be needed. Every
+ * block driver which implements it is probably doing something
+ * shady regarding its runtime option structure.
+ */
+ void (*bdrv_gather_child_options)(BlockDriverState *bs, QDict *target,
+ bool backing_overridden);
+
+ /*
+ * Returns an allocated string which is the directory name of this BDS: It
+ * will be used to make relative filenames absolute by prepending this
+ * function's return value to them.
+ */
+ char *(*bdrv_dirname)(BlockDriverState *bs, Error **errp);
+
+ /* aio */
+ BlockAIOCB *(*bdrv_aio_preadv)(BlockDriverState *bs,
+ int64_t offset, int64_t bytes, QEMUIOVector *qiov,
+ BdrvRequestFlags flags, BlockCompletionFunc *cb, void *opaque);
+ BlockAIOCB *(*bdrv_aio_pwritev)(BlockDriverState *bs,
+ int64_t offset, int64_t bytes, QEMUIOVector *qiov,
+ BdrvRequestFlags flags, BlockCompletionFunc *cb, void *opaque);
+ BlockAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
+ BlockCompletionFunc *cb, void *opaque);
+ BlockAIOCB *(*bdrv_aio_pdiscard)(BlockDriverState *bs,
+ int64_t offset, int bytes,
+ BlockCompletionFunc *cb, void *opaque);
+
+ int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
+
+ /**
+ * @offset: position in bytes to read at
+ * @bytes: number of bytes to read
+ * @qiov: the buffers to fill with read data
+ * @flags: currently unused, always 0
+ *
+ * @offset and @bytes will be a multiple of 'request_alignment',
+ * but the length of individual @qiov elements does not have to
+ * be a multiple.
+ *
+ * @bytes will always equal the total size of @qiov, and will be
+ * no larger than 'max_transfer'.
+ *
+ * The buffer in @qiov may point directly to guest memory.
+ */
+ int coroutine_fn (*bdrv_co_preadv)(BlockDriverState *bs,
+ int64_t offset, int64_t bytes, QEMUIOVector *qiov,
+ BdrvRequestFlags flags);
+
+ int coroutine_fn (*bdrv_co_preadv_part)(BlockDriverState *bs,
+ int64_t offset, int64_t bytes,
+ QEMUIOVector *qiov, size_t qiov_offset,
+ BdrvRequestFlags flags);
+
+ int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
+ int flags);
+ /**
+ * @offset: position in bytes to write at
+ * @bytes: number of bytes to write
+ * @qiov: the buffers containing data to write
+ * @flags: zero or more bits allowed by 'supported_write_flags'
+ *
+ * @offset and @bytes will be a multiple of 'request_alignment',
+ * but the length of individual @qiov elements does not have to
+ * be a multiple.
+ *
+ * @bytes will always equal the total size of @qiov, and will be
+ * no larger than 'max_transfer'.
+ *
+ * The buffer in @qiov may point directly to guest memory.
+ */
+ int coroutine_fn (*bdrv_co_pwritev)(BlockDriverState *bs,
+ int64_t offset, int64_t bytes, QEMUIOVector *qiov,
+ BdrvRequestFlags flags);
+ int coroutine_fn (*bdrv_co_pwritev_part)(BlockDriverState *bs,
+ int64_t offset, int64_t bytes, QEMUIOVector *qiov, size_t qiov_offset,
+ BdrvRequestFlags flags);
+
+ /*
+ * Efficiently zero a region of the disk image. Typically an image format
+ * would use a compact metadata representation to implement this. This
+ * function pointer may be NULL or return -ENOSUP and .bdrv_co_writev()
+ * will be called instead.
+ */
+ int coroutine_fn (*bdrv_co_pwrite_zeroes)(BlockDriverState *bs,
+ int64_t offset, int64_t bytes, BdrvRequestFlags flags);
+ int coroutine_fn (*bdrv_co_pdiscard)(BlockDriverState *bs,
+ int64_t offset, int64_t bytes);
+
+ /*
+ * Map [offset, offset + nbytes) range onto a child of @bs to copy from,
+ * and invoke bdrv_co_copy_range_from(child, ...), or invoke
+ * bdrv_co_copy_range_to() if @bs is the leaf child to copy data from.
+ *
+ * See the comment of bdrv_co_copy_range for the parameter and return value
+ * semantics.
+ */
+ int coroutine_fn (*bdrv_co_copy_range_from)(BlockDriverState *bs,
+ BdrvChild *src,
+ int64_t offset,
+ BdrvChild *dst,
+ int64_t dst_offset,
+ int64_t bytes,
+ BdrvRequestFlags read_flags,
+ BdrvRequestFlags write_flags);
+
+ /*
+ * Map [offset, offset + nbytes) range onto a child of bs to copy data to,
+ * and invoke bdrv_co_copy_range_to(child, src, ...), or perform the copy
+ * operation if @bs is the leaf and @src has the same BlockDriver. Return
+ * -ENOTSUP if @bs is the leaf but @src has a different BlockDriver.
+ *
+ * See the comment of bdrv_co_copy_range for the parameter and return value
+ * semantics.
+ */
+ int coroutine_fn (*bdrv_co_copy_range_to)(BlockDriverState *bs,
+ BdrvChild *src,
+ int64_t src_offset,
+ BdrvChild *dst,
+ int64_t dst_offset,
+ int64_t bytes,
+ BdrvRequestFlags read_flags,
+ BdrvRequestFlags write_flags);
+
+ /*
+ * Building block for bdrv_block_status[_above] and
+ * bdrv_is_allocated[_above]. The driver should answer only
+ * according to the current layer, and should only need to set
+ * BDRV_BLOCK_DATA, BDRV_BLOCK_ZERO, BDRV_BLOCK_OFFSET_VALID,
+ * and/or BDRV_BLOCK_RAW; if the current layer defers to a backing
+ * layer, the result should be 0 (and not BDRV_BLOCK_ZERO). See
+ * block.h for the overall meaning of the bits. As a hint, the
+ * flag want_zero is true if the caller cares more about precise
+ * mappings (favor accurate _OFFSET_VALID/_ZERO) or false for
+ * overall allocation (favor larger *pnum, perhaps by reporting
+ * _DATA instead of _ZERO). The block layer guarantees input
+ * clamped to bdrv_getlength() and aligned to request_alignment,
+ * as well as non-NULL pnum, map, and file; in turn, the driver
+ * must return an error or set pnum to an aligned non-zero value.
+ *
+ * Note that @bytes is just a hint on how big of a region the
+ * caller wants to inspect. It is not a limit on *pnum.
+ * Implementations are free to return larger values of *pnum if
+ * doing so does not incur a performance penalty.
+ *
+ * block/io.c's bdrv_co_block_status() will utilize an unclamped
+ * *pnum value for the block-status cache on protocol nodes, prior
+ * to clamping *pnum for return to its caller.
+ */
+ int coroutine_fn (*bdrv_co_block_status)(BlockDriverState *bs,
+ bool want_zero, int64_t offset, int64_t bytes, int64_t *pnum,
+ int64_t *map, BlockDriverState **file);
+
+ /*
+ * This informs the driver that we are no longer interested in the result
+ * of in-flight requests, so don't waste the time if possible.
+ *
+ * One example usage is to avoid waiting for an nbd target node reconnect
+ * timeout during job-cancel with force=true.
+ */
+ void (*bdrv_cancel_in_flight)(BlockDriverState *bs);
+
+ /*
+ * Invalidate any cached meta-data.
+ */
+ void coroutine_fn (*bdrv_co_invalidate_cache)(BlockDriverState *bs,
+ Error **errp);
+ int (*bdrv_inactivate)(BlockDriverState *bs);
+
+ /*
+ * Flushes all data for all layers by calling bdrv_co_flush for underlying
+ * layers, if needed. This function is needed for deterministic
+ * synchronization of the flush finishing callback.
+ */
+ int coroutine_fn (*bdrv_co_flush)(BlockDriverState *bs);
+
+ /* Delete a created file. */
+ int coroutine_fn (*bdrv_co_delete_file)(BlockDriverState *bs,
+ Error **errp);
+
+ /*
+ * Flushes all data that was already written to the OS all the way down to
+ * the disk (for example file-posix.c calls fsync()).
+ */
+ int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs);
+
+ /*
+ * Flushes all internal caches to the OS. The data may still sit in a
+ * writeback cache of the host OS, but it will survive a crash of the qemu
+ * process.
+ */
+ int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);
+
+ /*
+ * Drivers setting this field must be able to work with just a plain
+ * filename with '<protocol_name>:' as a prefix, and no other options.
+ * Options may be extracted from the filename by implementing
+ * bdrv_parse_filename.
+ */
+ const char *protocol_name;
+
+ /*
+ * Truncate @bs to @offset bytes using the given @prealloc mode
+ * when growing. Modes other than PREALLOC_MODE_OFF should be
+ * rejected when shrinking @bs.
+ *
+ * If @exact is true, @bs must be resized to exactly @offset.
+ * Otherwise, it is sufficient for @bs (if it is a host block
+ * device and thus there is no way to resize it) to be at least
+ * @offset bytes in length.
+ *
+ * If @exact is true and this function fails but would succeed
+ * with @exact = false, it should return -ENOTSUP.
+ */
+ int coroutine_fn (*bdrv_co_truncate)(BlockDriverState *bs, int64_t offset,
+ bool exact, PreallocMode prealloc,
+ BdrvRequestFlags flags, Error **errp);
+ int64_t (*bdrv_getlength)(BlockDriverState *bs);
+ bool has_variable_length;
+ int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);
+ BlockMeasureInfo *(*bdrv_measure)(QemuOpts *opts, BlockDriverState *in_bs,
+ Error **errp);
+
+ int coroutine_fn (*bdrv_co_pwritev_compressed)(BlockDriverState *bs,
+ int64_t offset, int64_t bytes, QEMUIOVector *qiov);
+ int coroutine_fn (*bdrv_co_pwritev_compressed_part)(BlockDriverState *bs,
+ int64_t offset, int64_t bytes, QEMUIOVector *qiov,
+ size_t qiov_offset);
+
+ int (*bdrv_snapshot_create)(BlockDriverState *bs,
+ QEMUSnapshotInfo *sn_info);
+ int (*bdrv_snapshot_goto)(BlockDriverState *bs,
+ const char *snapshot_id);
+ int (*bdrv_snapshot_delete)(BlockDriverState *bs,
+ const char *snapshot_id,
+ const char *name,
+ Error **errp);
+ int (*bdrv_snapshot_list)(BlockDriverState *bs,
+ QEMUSnapshotInfo **psn_info);
+ int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
+ const char *snapshot_id,
+ const char *name,
+ Error **errp);
+ int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
+
+ ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs,
+ Error **errp);
+ BlockStatsSpecific *(*bdrv_get_specific_stats)(BlockDriverState *bs);
+
+ int coroutine_fn (*bdrv_save_vmstate)(BlockDriverState *bs,
+ QEMUIOVector *qiov,
+ int64_t pos);
+ int coroutine_fn (*bdrv_load_vmstate)(BlockDriverState *bs,
+ QEMUIOVector *qiov,
+ int64_t pos);
+
+ int (*bdrv_change_backing_file)(BlockDriverState *bs,
+ const char *backing_file, const char *backing_fmt);
+
+ /* removable device specific */
+ bool (*bdrv_is_inserted)(BlockDriverState *bs);
+ void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
+ void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
+
+ /* to control generic scsi devices */
+ BlockAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
+ unsigned long int req, void *buf,
+ BlockCompletionFunc *cb, void *opaque);
+ int coroutine_fn (*bdrv_co_ioctl)(BlockDriverState *bs,
+ unsigned long int req, void *buf);
+
+ /* List of options for creating images, terminated by name == NULL */
+ QemuOptsList *create_opts;
+
+ /* List of options for image amend */
+ QemuOptsList *amend_opts;
+
+ /*
+ * If this driver supports reopening images this contains a
+ * NULL-terminated list of the runtime options that can be
+ * modified. If an option in this list is unspecified during
+ * reopen then it _must_ be reset to its default value or return
+ * an error.
+ */
+ const char *const *mutable_opts;
+
+ /*
+ * Returns 0 for completed check, -errno for internal errors.
+ * The check results are stored in result.
+ */
+ int coroutine_fn (*bdrv_co_check)(BlockDriverState *bs,
+ BdrvCheckResult *result,
+ BdrvCheckMode fix);
+
+ void (*bdrv_debug_event)(BlockDriverState *bs, BlkdebugEvent event);
+
+ /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */
+ int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event,
+ const char *tag);
+ int (*bdrv_debug_remove_breakpoint)(BlockDriverState *bs,
+ const char *tag);
+ int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag);
+ bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag);
+
+ void (*bdrv_refresh_limits)(BlockDriverState *bs, Error **errp);
+
+ /*
+ * Returns 1 if newly created images are guaranteed to contain only
+ * zeros, 0 otherwise.
+ */
+ int (*bdrv_has_zero_init)(BlockDriverState *bs);
+
+ /*
+ * Remove fd handlers, timers, and other event loop callbacks so the event
+ * loop is no longer in use. Called with no in-flight requests and in
+ * depth-first traversal order with parents before child nodes.
+ */
+ void (*bdrv_detach_aio_context)(BlockDriverState *bs);
+
+ /*
+ * Add fd handlers, timers, and other event loop callbacks so I/O requests
+ * can be processed again. Called with no in-flight requests and in
+ * depth-first traversal order with child nodes before parent nodes.
+ */
+ void (*bdrv_attach_aio_context)(BlockDriverState *bs,
+ AioContext *new_context);
+
+ /* io queue for linux-aio */
+ void (*bdrv_io_plug)(BlockDriverState *bs);
+ void (*bdrv_io_unplug)(BlockDriverState *bs);
+
+ /**
+ * Try to get @bs's logical and physical block size.
+ * On success, store them in @bsz and return zero.
+ * On failure, return negative errno.
+ */
+ int (*bdrv_probe_blocksizes)(BlockDriverState *bs, BlockSizes *bsz);
+ /**
+ * Try to get @bs's geometry (cyls, heads, sectors)
+ * On success, store them in @geo and return 0.
+ * On failure return -errno.
+ * Only drivers that want to override guest geometry implement this
+ * callback; see hd_geometry_guess().
+ */
+ int (*bdrv_probe_geometry)(BlockDriverState *bs, HDGeometry *geo);
+
+ /**
+ * bdrv_co_drain_begin is called if implemented in the beginning of a
+ * drain operation to drain and stop any internal sources of requests in
+ * the driver.
+ * bdrv_co_drain_end is called if implemented at the end of the drain.
+ *
+ * They should be used by the driver to e.g. manage scheduled I/O
+ * requests, or toggle an internal state. After the end of the drain new
+ * requests will continue normally.
+ */
+ void coroutine_fn (*bdrv_co_drain_begin)(BlockDriverState *bs);
+ void coroutine_fn (*bdrv_co_drain_end)(BlockDriverState *bs);
+
+ void (*bdrv_add_child)(BlockDriverState *parent, BlockDriverState *child,
+ Error **errp);
+ void (*bdrv_del_child)(BlockDriverState *parent, BdrvChild *child,
+ Error **errp);
+
+ /**
+ * Informs the block driver that a permission change is intended. The
+ * driver checks whether the change is permissible and may take other
+ * preparations for the change (e.g. get file system locks). This operation
+ * is always followed either by a call to either .bdrv_set_perm or
+ * .bdrv_abort_perm_update.
+ *
+ * Checks whether the requested set of cumulative permissions in @perm
+ * can be granted for accessing @bs and whether no other users are using
+ * permissions other than those given in @shared (both arguments take
+ * BLK_PERM_* bitmasks).
+ *
+ * If both conditions are met, 0 is returned. Otherwise, -errno is returned
+ * and errp is set to an error describing the conflict.
+ */
+ int (*bdrv_check_perm)(BlockDriverState *bs, uint64_t perm,
+ uint64_t shared, Error **errp);
+
+ /**
+ * Called to inform the driver that the set of cumulative set of used
+ * permissions for @bs has changed to @perm, and the set of sharable
+ * permission to @shared. The driver can use this to propagate changes to
+ * its children (i.e. request permissions only if a parent actually needs
+ * them).
+ *
+ * This function is only invoked after bdrv_check_perm(), so block drivers
+ * may rely on preparations made in their .bdrv_check_perm implementation.
+ */
+ void (*bdrv_set_perm)(BlockDriverState *bs, uint64_t perm, uint64_t shared);
+
+ /*
+ * Called to inform the driver that after a previous bdrv_check_perm()
+ * call, the permission update is not performed and any preparations made
+ * for it (e.g. taken file locks) need to be undone.
+ *
+ * This function can be called even for nodes that never saw a
+ * bdrv_check_perm() call. It is a no-op then.
+ */
+ void (*bdrv_abort_perm_update)(BlockDriverState *bs);
+
+ /**
+ * Returns in @nperm and @nshared the permissions that the driver for @bs
+ * needs on its child @c, based on the cumulative permissions requested by
+ * the parents in @parent_perm and @parent_shared.
+ *
+ * If @c is NULL, return the permissions for attaching a new child for the
+ * given @child_class and @role.
+ *
+ * If @reopen_queue is non-NULL, don't return the currently needed
+ * permissions, but those that will be needed after applying the
+ * @reopen_queue.
+ */
+ void (*bdrv_child_perm)(BlockDriverState *bs, BdrvChild *c,
+ BdrvChildRole role,
+ BlockReopenQueue *reopen_queue,
+ uint64_t parent_perm, uint64_t parent_shared,
+ uint64_t *nperm, uint64_t *nshared);
+
+ bool (*bdrv_supports_persistent_dirty_bitmap)(BlockDriverState *bs);
+ bool (*bdrv_co_can_store_new_dirty_bitmap)(BlockDriverState *bs,
+ const char *name,
+ uint32_t granularity,
+ Error **errp);
+ int (*bdrv_co_remove_persistent_dirty_bitmap)(BlockDriverState *bs,
+ const char *name,
+ Error **errp);
+
+ /**
+ * Register/unregister a buffer for I/O. For example, when the driver is
+ * interested to know the memory areas that will later be used in iovs, so
+ * that it can do IOMMU mapping with VFIO etc., in order to get better
+ * performance. In the case of VFIO drivers, this callback is used to do
+ * DMA mapping for hot buffers.
+ */
+ void (*bdrv_register_buf)(BlockDriverState *bs, void *host, size_t size);
+ void (*bdrv_unregister_buf)(BlockDriverState *bs, void *host);
+ QLIST_ENTRY(BlockDriver) list;
+
+ /*
+ * Pointer to a NULL-terminated array of names of strong options
+ * that can be specified for bdrv_open(). A strong option is one
+ * that changes the data of a BDS.
+ * If this pointer is NULL, the array is considered empty.
+ * "filename" and "driver" are always considered strong.
+ */
+ const char *const *strong_runtime_opts;
+};
+
+static inline bool block_driver_can_compress(BlockDriver *drv)
+{
+ return drv->bdrv_co_pwritev_compressed ||
+ drv->bdrv_co_pwritev_compressed_part;
+}
+
+typedef struct BlockLimits {
+ /*
+ * Alignment requirement, in bytes, for offset/length of I/O
+ * requests. Must be a power of 2 less than INT_MAX; defaults to
+ * 1 for drivers with modern byte interfaces, and to 512
+ * otherwise.
+ */
+ uint32_t request_alignment;
+
+ /*
+ * Maximum number of bytes that can be discarded at once. Must be multiple
+ * of pdiscard_alignment, but need not be power of 2. May be 0 if no
+ * inherent 64-bit limit.
+ */
+ int64_t max_pdiscard;
+
+ /*
+ * Optimal alignment for discard requests in bytes. A power of 2
+ * is best but not mandatory. Must be a multiple of
+ * bl.request_alignment, and must be less than max_pdiscard if
+ * that is set. May be 0 if bl.request_alignment is good enough
+ */
+ uint32_t pdiscard_alignment;
+
+ /*
+ * Maximum number of bytes that can zeroized at once. Must be multiple of
+ * pwrite_zeroes_alignment. 0 means no limit.
+ */
+ int64_t max_pwrite_zeroes;
+
+ /*
+ * Optimal alignment for write zeroes requests in bytes. A power
+ * of 2 is best but not mandatory. Must be a multiple of
+ * bl.request_alignment, and must be less than max_pwrite_zeroes
+ * if that is set. May be 0 if bl.request_alignment is good
+ * enough
+ */
+ uint32_t pwrite_zeroes_alignment;
+
+ /*
+ * Optimal transfer length in bytes. A power of 2 is best but not
+ * mandatory. Must be a multiple of bl.request_alignment, or 0 if
+ * no preferred size
+ */
+ uint32_t opt_transfer;
+
+ /*
+ * Maximal transfer length in bytes. Need not be power of 2, but
+ * must be multiple of opt_transfer and bl.request_alignment, or 0
+ * for no 32-bit limit. For now, anything larger than INT_MAX is
+ * clamped down.
+ */
+ uint32_t max_transfer;
+
+ /*
+ * Maximal hardware transfer length in bytes. Applies whenever
+ * transfers to the device bypass the kernel I/O scheduler, for
+ * example with SG_IO. If larger than max_transfer or if zero,
+ * blk_get_max_hw_transfer will fall back to max_transfer.
+ */
+ uint64_t max_hw_transfer;
+
+ /*
+ * Maximal number of scatter/gather elements allowed by the hardware.
+ * Applies whenever transfers to the device bypass the kernel I/O
+ * scheduler, for example with SG_IO. If larger than max_iov
+ * or if zero, blk_get_max_hw_iov will fall back to max_iov.
+ */
+ int max_hw_iov;
+
+
+ /* memory alignment, in bytes so that no bounce buffer is needed */
+ size_t min_mem_alignment;
+
+ /* memory alignment, in bytes, for bounce buffer */
+ size_t opt_mem_alignment;
+
+ /* maximum number of iovec elements */
+ int max_iov;
+} BlockLimits;
+
+typedef struct BdrvOpBlocker BdrvOpBlocker;
+
+typedef struct BdrvAioNotifier {
+ void (*attached_aio_context)(AioContext *new_context, void *opaque);
+ void (*detach_aio_context)(void *opaque);
+
+ void *opaque;
+ bool deleted;
+
+ QLIST_ENTRY(BdrvAioNotifier) list;
+} BdrvAioNotifier;
+
+struct BdrvChildClass {
+ /*
+ * If true, bdrv_replace_node() doesn't change the node this BdrvChild
+ * points to.
+ */
+ bool stay_at_node;
+
+ /*
+ * If true, the parent is a BlockDriverState and bdrv_next_all_states()
+ * will return it. This information is used for drain_all, where every node
+ * will be drained separately, so the drain only needs to be propagated to
+ * non-BDS parents.
+ */
+ bool parent_is_bds;
+
+ void (*inherit_options)(BdrvChildRole role, bool parent_is_format,
+ int *child_flags, QDict *child_options,
+ int parent_flags, QDict *parent_options);
+
+ void (*change_media)(BdrvChild *child, bool load);
+ void (*resize)(BdrvChild *child);
+
+ /*
+ * Returns a name that is supposedly more useful for human users than the
+ * node name for identifying the node in question (in particular, a BB
+ * name), or NULL if the parent can't provide a better name.
+ */
+ const char *(*get_name)(BdrvChild *child);
+
+ /*
+ * Returns a malloced string that describes the parent of the child for a
+ * human reader. This could be a node-name, BlockBackend name, qdev ID or
+ * QOM path of the device owning the BlockBackend, job type and ID etc. The
+ * caller is responsible for freeing the memory.
+ */
+ char *(*get_parent_desc)(BdrvChild *child);
+
+ /*
+ * If this pair of functions is implemented, the parent doesn't issue new
+ * requests after returning from .drained_begin() until .drained_end() is
+ * called.
+ *
+ * These functions must not change the graph (and therefore also must not
+ * call aio_poll(), which could change the graph indirectly).
+ *
+ * If drained_end() schedules background operations, it must atomically
+ * increment *drained_end_counter for each such operation and atomically
+ * decrement it once the operation has settled.
+ *
+ * Note that this can be nested. If drained_begin() was called twice, new
+ * I/O is allowed only after drained_end() was called twice, too.
+ */
+ void (*drained_begin)(BdrvChild *child);
+ void (*drained_end)(BdrvChild *child, int *drained_end_counter);
+
+ /*
+ * Returns whether the parent has pending requests for the child. This
+ * callback is polled after .drained_begin() has been called until all
+ * activity on the child has stopped.
+ */
+ bool (*drained_poll)(BdrvChild *child);
+
+ /*
+ * Notifies the parent that the child has been activated/inactivated (e.g.
+ * when migration is completing) and it can start/stop requesting
+ * permissions and doing I/O on it.
+ */
+ void (*activate)(BdrvChild *child, Error **errp);
+ int (*inactivate)(BdrvChild *child);
+
+ void (*attach)(BdrvChild *child);
+ void (*detach)(BdrvChild *child);
+
+ /*
+ * Notifies the parent that the filename of its child has changed (e.g.
+ * because the direct child was removed from the backing chain), so that it
+ * can update its reference.
+ */
+ int (*update_filename)(BdrvChild *child, BlockDriverState *new_base,
+ const char *filename, Error **errp);
+
+ bool (*can_set_aio_ctx)(BdrvChild *child, AioContext *ctx,
+ GSList **ignore, Error **errp);
+ void (*set_aio_ctx)(BdrvChild *child, AioContext *ctx, GSList **ignore);
+
+ AioContext *(*get_parent_aio_context)(BdrvChild *child);
+};
+
+extern const BdrvChildClass child_of_bds;
+
+struct BdrvChild {
+ BlockDriverState *bs;
+ char *name;
+ const BdrvChildClass *klass;
+ BdrvChildRole role;
+ void *opaque;
+
+ /**
+ * Granted permissions for operating on this BdrvChild (BLK_PERM_* bitmask)
+ */
+ uint64_t perm;
+
+ /**
+ * Permissions that can still be granted to other users of @bs while this
+ * BdrvChild is still attached to it. (BLK_PERM_* bitmask)
+ */
+ uint64_t shared_perm;
+
+ /*
+ * This link is frozen: the child can neither be replaced nor
+ * detached from the parent.
+ */
+ bool frozen;
+
+ /*
+ * How many times the parent of this child has been drained
+ * (through klass->drained_*).
+ * Usually, this is equal to bs->quiesce_counter (potentially
+ * reduced by bdrv_drain_all_count). It may differ while the
+ * child is entering or leaving a drained section.
+ */
+ int parent_quiesce_counter;
+
+ QLIST_ENTRY(BdrvChild) next;
+ QLIST_ENTRY(BdrvChild) next_parent;
+};
+
+/*
+ * Allows bdrv_co_block_status() to cache one data region for a
+ * protocol node.
+ *
+ * @valid: Whether the cache is valid (should be accessed with atomic
+ * functions so this can be reset by RCU readers)
+ * @data_start: Offset where we know (or strongly assume) is data
+ * @data_end: Offset where the data region ends (which is not necessarily
+ * the start of a zeroed region)
+ */
+typedef struct BdrvBlockStatusCache {
+ struct rcu_head rcu;
+
+ bool valid;
+ int64_t data_start;
+ int64_t data_end;
+} BdrvBlockStatusCache;
+
+struct BlockDriverState {
+ /*
+ * Protected by big QEMU lock or read-only after opening. No special
+ * locking needed during I/O...
+ */
+ int open_flags; /* flags used to open the file, re-used for re-open */
+ bool encrypted; /* if true, the media is encrypted */
+ bool sg; /* if true, the device is a /dev/sg* */
+ bool probed; /* if true, format was probed rather than specified */
+ bool force_share; /* if true, always allow all shared permissions */
+ bool implicit; /* if true, this filter node was automatically inserted */
+
+ BlockDriver *drv; /* NULL means no media */
+ void *opaque;
+
+ AioContext *aio_context; /* event loop used for fd handlers, timers, etc */
+ /*
+ * long-running tasks intended to always use the same AioContext as this
+ * BDS may register themselves in this list to be notified of changes
+ * regarding this BDS's context
+ */
+ QLIST_HEAD(, BdrvAioNotifier) aio_notifiers;
+ bool walking_aio_notifiers; /* to make removal during iteration safe */
+
+ char filename[PATH_MAX];
+ /*
+ * If not empty, this image is a diff in relation to backing_file.
+ * Note that this is the name given in the image header and
+ * therefore may or may not be equal to .backing->bs->filename.
+ * If this field contains a relative path, it is to be resolved
+ * relatively to the overlay's location.
+ */
+ char backing_file[PATH_MAX];
+ /*
+ * The backing filename indicated by the image header. Contrary
+ * to backing_file, if we ever open this file, auto_backing_file
+ * is replaced by the resulting BDS's filename (i.e. after a
+ * bdrv_refresh_filename() run).
+ */
+ char auto_backing_file[PATH_MAX];
+ char backing_format[16]; /* if non-zero and backing_file exists */
+
+ QDict *full_open_options;
+ char exact_filename[PATH_MAX];
+
+ BdrvChild *backing;
+ BdrvChild *file;
+
+ /* I/O Limits */
+ BlockLimits bl;
+
+ /*
+ * Flags honored during pread
+ */
+ unsigned int supported_read_flags;
+ /*
+ * Flags honored during pwrite (so far: BDRV_REQ_FUA,
+ * BDRV_REQ_WRITE_UNCHANGED).
+ * If a driver does not support BDRV_REQ_WRITE_UNCHANGED, those
+ * writes will be issued as normal writes without the flag set.
+ * This is important to note for drivers that do not explicitly
+ * request a WRITE permission for their children and instead take
+ * the same permissions as their parent did (this is commonly what
+ * block filters do). Such drivers have to be aware that the
+ * parent may have taken a WRITE_UNCHANGED permission only and is
+ * issuing such requests. Drivers either must make sure that
+ * these requests do not result in plain WRITE accesses (usually
+ * by supporting BDRV_REQ_WRITE_UNCHANGED, and then forwarding
+ * every incoming write request as-is, including potentially that
+ * flag), or they have to explicitly take the WRITE permission for
+ * their children.
+ */
+ unsigned int supported_write_flags;
+ /*
+ * Flags honored during pwrite_zeroes (so far: BDRV_REQ_FUA,
+ * BDRV_REQ_MAY_UNMAP, BDRV_REQ_WRITE_UNCHANGED)
+ */
+ unsigned int supported_zero_flags;
+ /*
+ * Flags honoured during truncate (so far: BDRV_REQ_ZERO_WRITE).
+ *
+ * If BDRV_REQ_ZERO_WRITE is given, the truncate operation must make sure
+ * that any added space reads as all zeros. If this can't be guaranteed,
+ * the operation must fail.
+ */
+ unsigned int supported_truncate_flags;
+
+ /* the following member gives a name to every node on the bs graph. */
+ char node_name[32];
+ /* element of the list of named nodes building the graph */
+ QTAILQ_ENTRY(BlockDriverState) node_list;
+ /* element of the list of all BlockDriverStates (all_bdrv_states) */
+ QTAILQ_ENTRY(BlockDriverState) bs_list;
+ /* element of the list of monitor-owned BDS */
+ QTAILQ_ENTRY(BlockDriverState) monitor_list;
+ int refcnt;
+
+ /* operation blockers. Protected by BQL. */
+ QLIST_HEAD(, BdrvOpBlocker) op_blockers[BLOCK_OP_TYPE_MAX];
+
+ /*
+ * The node that this node inherited default options from (and a reopen on
+ * which can affect this node by changing these defaults). This is always a
+ * parent node of this node.
+ */
+ BlockDriverState *inherits_from;
+ QLIST_HEAD(, BdrvChild) children;
+ QLIST_HEAD(, BdrvChild) parents;
+
+ QDict *options;
+ QDict *explicit_options;
+ BlockdevDetectZeroesOptions detect_zeroes;
+
+ /* The error object in use for blocking operations on backing_hd */
+ Error *backing_blocker;
+
+ /* Protected by AioContext lock */
+
+ /*
+ * If we are reading a disk image, give its size in sectors.
+ * Generally read-only; it is written to by load_snapshot and
+ * save_snaphost, but the block layer is quiescent during those.
+ */
+ int64_t total_sectors;
+
+ /* threshold limit for writes, in bytes. "High water mark". */
+ uint64_t write_threshold_offset;
+
+ /*
+ * Writing to the list requires the BQL _and_ the dirty_bitmap_mutex.
+ * Reading from the list can be done with either the BQL or the
+ * dirty_bitmap_mutex. Modifying a bitmap only requires
+ * dirty_bitmap_mutex.
+ */
+ QemuMutex dirty_bitmap_mutex;
+ QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps;
+
+ /* Offset after the highest byte written to */
+ Stat64 wr_highest_offset;
+
+ /*
+ * If true, copy read backing sectors into image. Can be >1 if more
+ * than one client has requested copy-on-read. Accessed with atomic
+ * ops.
+ */
+ int copy_on_read;
+
+ /*
+ * number of in-flight requests; overall and serialising.
+ * Accessed with atomic ops.
+ */
+ unsigned int in_flight;
+ unsigned int serialising_in_flight;
+
+ /*
+ * counter for nested bdrv_io_plug.
+ * Accessed with atomic ops.
+ */
+ unsigned io_plugged;
+
+ /* do we need to tell the quest if we have a volatile write cache? */
+ int enable_write_cache;
+
+ /* Accessed with atomic ops. */
+ int quiesce_counter;
+ int recursive_quiesce_counter;
+
+ unsigned int write_gen; /* Current data generation */
+
+ /* Protected by reqs_lock. */
+ CoMutex reqs_lock;
+ QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
+ CoQueue flush_queue; /* Serializing flush queue */
+ bool active_flush_req; /* Flush request in flight? */
+
+ /* Only read/written by whoever has set active_flush_req to true. */
+ unsigned int flushed_gen; /* Flushed write generation */
+
+ /* BdrvChild links to this node may never be frozen */
+ bool never_freeze;
+
+ /* Lock for block-status cache RCU writers */
+ CoMutex bsc_modify_lock;
+ /* Always non-NULL, but must only be dereferenced under an RCU read guard */
+ BdrvBlockStatusCache *block_status_cache;
+};
+
+struct BlockBackendRootState {
+ int open_flags;
+ BlockdevDetectZeroesOptions detect_zeroes;
+};
+
+typedef enum BlockMirrorBackingMode {
+ /*
+ * Reuse the existing backing chain from the source for the target.
+ * - sync=full: Set backing BDS to NULL.
+ * - sync=top: Use source's backing BDS.
+ * - sync=none: Use source as the backing BDS.
+ */
+ MIRROR_SOURCE_BACKING_CHAIN,
+
+ /* Open the target's backing chain completely anew */
+ MIRROR_OPEN_BACKING_CHAIN,
+
+ /* Do not change the target's backing BDS after job completion */
+ MIRROR_LEAVE_BACKING_CHAIN,
+} BlockMirrorBackingMode;
+
+
+/*
+ * Essential block drivers which must always be statically linked into qemu, and
+ * which therefore can be accessed without using bdrv_find_format()
+ */
+extern BlockDriver bdrv_file;
+extern BlockDriver bdrv_raw;
+extern BlockDriver bdrv_qcow2;
+
+extern unsigned int bdrv_drain_all_count;
+extern QemuOptsList bdrv_create_opts_simple;
+
+/* Common functions that are neither I/O nor Global State */
+
+static inline BlockDriverState *child_bs(BdrvChild *child)
+{
+ return child ? child->bs : NULL;
+}
+
+int bdrv_check_request(int64_t offset, int64_t bytes, Error **errp);
+int get_tmp_filename(char *filename, int size);
+void bdrv_parse_filename_strip_prefix(const char *filename, const char *prefix,
+ QDict *options);
+
+
+int bdrv_check_qiov_request(int64_t offset, int64_t bytes,
+ QEMUIOVector *qiov, size_t qiov_offset,
+ Error **errp);
+
+#ifdef _WIN32
+int is_windows_drive(const char *filename);
+#endif
+
+#endif /* BLOCK_INT_COMMON_H */
diff --git a/include/block/block_int-global-state.h b/include/block/block_int-global-state.h
new file mode 100644
index 0000000000..a1b7d0579d
--- /dev/null
+++ b/include/block/block_int-global-state.h
@@ -0,0 +1,315 @@
+/*
+ * QEMU System Emulator block driver
+ *
+ * Copyright (c) 2003 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#ifndef BLOCK_INT_GLOBAL_STATE_H
+#define BLOCK_INT_GLOBAL_STATE_H
+
+#include "block_int-common.h"
+
+/*
+ * Global state (GS) API. These functions run under the BQL lock.
+ *
+ * See include/block/block-global-state.h for more information about
+ * the GS API.
+ */
+
+BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
+ const char *filename);
+
+/**
+ * stream_start:
+ * @job_id: The id of the newly-created job, or %NULL to use the
+ * device name of @bs.
+ * @bs: Block device to operate on.
+ * @base: Block device that will become the new base, or %NULL to
+ * flatten the whole backing file chain onto @bs.
+ * @backing_file_str: The file name that will be written to @bs as the
+ * the new backing file if the job completes. Ignored if @base is %NULL.
+ * @creation_flags: Flags that control the behavior of the Job lifetime.
+ * See @BlockJobCreateFlags
+ * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
+ * @on_error: The action to take upon error.
+ * @filter_node_name: The node name that should be assigned to the filter
+ * driver that the stream job inserts into the graph above
+ * @bs. NULL means that a node name should be autogenerated.
+ * @errp: Error object.
+ *
+ * Start a streaming operation on @bs. Clusters that are unallocated
+ * in @bs, but allocated in any image between @base and @bs (both
+ * exclusive) will be written to @bs. At the end of a successful
+ * streaming job, the backing file of @bs will be changed to
+ * @backing_file_str in the written image and to @base in the live
+ * BlockDriverState.
+ */
+void stream_start(const char *job_id, BlockDriverState *bs,
+ BlockDriverState *base, const char *backing_file_str,
+ BlockDriverState *bottom,
+ int creation_flags, int64_t speed,
+ BlockdevOnError on_error,
+ const char *filter_node_name,
+ Error **errp);
+
+/**
+ * commit_start:
+ * @job_id: The id of the newly-created job, or %NULL to use the
+ * device name of @bs.
+ * @bs: Active block device.
+ * @top: Top block device to be committed.
+ * @base: Block device that will be written into, and become the new top.
+ * @creation_flags: Flags that control the behavior of the Job lifetime.
+ * See @BlockJobCreateFlags
+ * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
+ * @on_error: The action to take upon error.
+ * @backing_file_str: String to use as the backing file in @top's overlay
+ * @filter_node_name: The node name that should be assigned to the filter
+ * driver that the commit job inserts into the graph above @top. NULL means
+ * that a node name should be autogenerated.
+ * @errp: Error object.
+ *
+ */
+void commit_start(const char *job_id, BlockDriverState *bs,
+ BlockDriverState *base, BlockDriverState *top,
+ int creation_flags, int64_t speed,
+ BlockdevOnError on_error, const char *backing_file_str,
+ const char *filter_node_name, Error **errp);
+/**
+ * commit_active_start:
+ * @job_id: The id of the newly-created job, or %NULL to use the
+ * device name of @bs.
+ * @bs: Active block device to be committed.
+ * @base: Block device that will be written into, and become the new top.
+ * @creation_flags: Flags that control the behavior of the Job lifetime.
+ * See @BlockJobCreateFlags
+ * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
+ * @on_error: The action to take upon error.
+ * @filter_node_name: The node name that should be assigned to the filter
+ * driver that the commit job inserts into the graph above @bs. NULL means that
+ * a node name should be autogenerated.
+ * @cb: Completion function for the job.
+ * @opaque: Opaque pointer value passed to @cb.
+ * @auto_complete: Auto complete the job.
+ * @errp: Error object.
+ *
+ */
+BlockJob *commit_active_start(const char *job_id, BlockDriverState *bs,
+ BlockDriverState *base, int creation_flags,
+ int64_t speed, BlockdevOnError on_error,
+ const char *filter_node_name,
+ BlockCompletionFunc *cb, void *opaque,
+ bool auto_complete, Error **errp);
+/*
+ * mirror_start:
+ * @job_id: The id of the newly-created job, or %NULL to use the
+ * device name of @bs.
+ * @bs: Block device to operate on.
+ * @target: Block device to write to.
+ * @replaces: Block graph node name to replace once the mirror is done. Can
+ * only be used when full mirroring is selected.
+ * @creation_flags: Flags that control the behavior of the Job lifetime.
+ * See @BlockJobCreateFlags
+ * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
+ * @granularity: The chosen granularity for the dirty bitmap.
+ * @buf_size: The amount of data that can be in flight at one time.
+ * @mode: Whether to collapse all images in the chain to the target.
+ * @backing_mode: How to establish the target's backing chain after completion.
+ * @zero_target: Whether the target should be explicitly zero-initialized
+ * @on_source_error: The action to take upon error reading from the source.
+ * @on_target_error: The action to take upon error writing to the target.
+ * @unmap: Whether to unmap target where source sectors only contain zeroes.
+ * @filter_node_name: The node name that should be assigned to the filter
+ * driver that the mirror job inserts into the graph above @bs. NULL means that
+ * a node name should be autogenerated.
+ * @copy_mode: When to trigger writes to the target.
+ * @errp: Error object.
+ *
+ * Start a mirroring operation on @bs. Clusters that are allocated
+ * in @bs will be written to @target until the job is cancelled or
+ * manually completed. At the end of a successful mirroring job,
+ * @bs will be switched to read from @target.
+ */
+void mirror_start(const char *job_id, BlockDriverState *bs,
+ BlockDriverState *target, const char *replaces,
+ int creation_flags, int64_t speed,
+ uint32_t granularity, int64_t buf_size,
+ MirrorSyncMode mode, BlockMirrorBackingMode backing_mode,
+ bool zero_target,
+ BlockdevOnError on_source_error,
+ BlockdevOnError on_target_error,
+ bool unmap, const char *filter_node_name,
+ MirrorCopyMode copy_mode, Error **errp);
+
+/*
+ * backup_job_create:
+ * @job_id: The id of the newly-created job, or %NULL to use the
+ * device name of @bs.
+ * @bs: Block device to operate on.
+ * @target: Block device to write to.
+ * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
+ * @sync_mode: What parts of the disk image should be copied to the destination.
+ * @sync_bitmap: The dirty bitmap if sync_mode is 'bitmap' or 'incremental'
+ * @bitmap_mode: The bitmap synchronization policy to use.
+ * @perf: Performance options. All actual fields assumed to be present,
+ * all ".has_*" fields are ignored.
+ * @on_source_error: The action to take upon error reading from the source.
+ * @on_target_error: The action to take upon error writing to the target.
+ * @creation_flags: Flags that control the behavior of the Job lifetime.
+ * See @BlockJobCreateFlags
+ * @cb: Completion function for the job.
+ * @opaque: Opaque pointer value passed to @cb.
+ * @txn: Transaction that this job is part of (may be NULL).
+ *
+ * Create a backup operation on @bs. Clusters in @bs are written to @target
+ * until the job is cancelled or manually completed.
+ */
+BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
+ BlockDriverState *target, int64_t speed,
+ MirrorSyncMode sync_mode,
+ BdrvDirtyBitmap *sync_bitmap,
+ BitmapSyncMode bitmap_mode,
+ bool compress,
+ const char *filter_node_name,
+ BackupPerf *perf,
+ BlockdevOnError on_source_error,
+ BlockdevOnError on_target_error,
+ int creation_flags,
+ BlockCompletionFunc *cb, void *opaque,
+ JobTxn *txn, Error **errp);
+
+BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
+ const char *child_name,
+ const BdrvChildClass *child_class,
+ BdrvChildRole child_role,
+ uint64_t perm, uint64_t shared_perm,
+ void *opaque, Error **errp);
+void bdrv_root_unref_child(BdrvChild *child);
+
+void bdrv_get_cumulative_perm(BlockDriverState *bs, uint64_t *perm,
+ uint64_t *shared_perm);
+
+/**
+ * Sets a BdrvChild's permissions. Avoid if the parent is a BDS; use
+ * bdrv_child_refresh_perms() instead and make the parent's
+ * .bdrv_child_perm() implementation return the correct values.
+ */
+int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared,
+ Error **errp);
+
+/**
+ * Calls bs->drv->bdrv_child_perm() and updates the child's permission
+ * masks with the result.
+ * Drivers should invoke this function whenever an event occurs that
+ * makes their .bdrv_child_perm() implementation return different
+ * values than before, but which will not result in the block layer
+ * automatically refreshing the permissions.
+ */
+int bdrv_child_refresh_perms(BlockDriverState *bs, BdrvChild *c, Error **errp);
+
+bool bdrv_recurse_can_replace(BlockDriverState *bs,
+ BlockDriverState *to_replace);
+
+/*
+ * Default implementation for BlockDriver.bdrv_child_perm() that can
+ * be used by block filters and image formats, as long as they use the
+ * child_of_bds child class and set an appropriate BdrvChildRole.
+ */
+void bdrv_default_perms(BlockDriverState *bs, BdrvChild *c,
+ BdrvChildRole role, BlockReopenQueue *reopen_queue,
+ uint64_t perm, uint64_t shared,
+ uint64_t *nperm, uint64_t *nshared);
+
+void blk_dev_change_media_cb(BlockBackend *blk, bool load, Error **errp);
+bool blk_dev_has_removable_media(BlockBackend *blk);
+void blk_dev_eject_request(BlockBackend *blk, bool force);
+bool blk_dev_is_medium_locked(BlockBackend *blk);
+
+void bdrv_restore_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *backup);
+
+void bdrv_set_monitor_owned(BlockDriverState *bs);
+
+void blockdev_close_all_bdrv_states(void);
+
+BlockDriverState *bds_tree_init(QDict *bs_opts, Error **errp);
+
+/**
+ * Simple implementation of bdrv_co_create_opts for protocol drivers
+ * which only support creation via opening a file
+ * (usually existing raw storage device)
+ */
+int coroutine_fn bdrv_co_create_opts_simple(BlockDriver *drv,
+ const char *filename,
+ QemuOpts *opts,
+ Error **errp);
+
+BdrvDirtyBitmap *block_dirty_bitmap_lookup(const char *node,
+ const char *name,
+ BlockDriverState **pbs,
+ Error **errp);
+BdrvDirtyBitmap *block_dirty_bitmap_merge(const char *node, const char *target,
+ BlockDirtyBitmapMergeSourceList *bms,
+ HBitmap **backup, Error **errp);
+BdrvDirtyBitmap *block_dirty_bitmap_remove(const char *node, const char *name,
+ bool release,
+ BlockDriverState **bitmap_bs,
+ Error **errp);
+
+
+BlockDriverState *bdrv_skip_implicit_filters(BlockDriverState *bs);
+
+/**
+ * bdrv_add_aio_context_notifier:
+ *
+ * If a long-running job intends to be always run in the same AioContext as a
+ * certain BDS, it may use this function to be notified of changes regarding the
+ * association of the BDS to an AioContext.
+ *
+ * attached_aio_context() is called after the target BDS has been attached to a
+ * new AioContext; detach_aio_context() is called before the target BDS is being
+ * detached from its old AioContext.
+ */
+void bdrv_add_aio_context_notifier(BlockDriverState *bs,
+ void (*attached_aio_context)(AioContext *new_context, void *opaque),
+ void (*detach_aio_context)(void *opaque), void *opaque);
+
+/**
+ * bdrv_remove_aio_context_notifier:
+ *
+ * Unsubscribe of change notifications regarding the BDS's AioContext. The
+ * parameters given here have to be the same as those given to
+ * bdrv_add_aio_context_notifier().
+ */
+void bdrv_remove_aio_context_notifier(BlockDriverState *bs,
+ void (*aio_context_attached)(AioContext *,
+ void *),
+ void (*aio_context_detached)(void *),
+ void *opaque);
+
+/**
+ * End all quiescent sections started by bdrv_drain_all_begin(). This is
+ * needed when deleting a BDS before bdrv_drain_all_end() is called.
+ *
+ * NOTE: this is an internal helper for bdrv_close() *only*. No one else
+ * should call it.
+ */
+void bdrv_drain_all_end_quiesce(BlockDriverState *bs);
+
+#endif /* BLOCK_INT_GLOBAL_STATE*/
diff --git a/include/block/block_int-io.h b/include/block/block_int-io.h
new file mode 100644
index 0000000000..e9e47eb129
--- /dev/null
+++ b/include/block/block_int-io.h
@@ -0,0 +1,167 @@
+/*
+ * QEMU System Emulator block driver
+ *
+ * Copyright (c) 2003 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#ifndef BLOCK_INT_IO_H
+#define BLOCK_INT_IO_H
+
+#include "block_int-common.h"
+
+/*
+ * I/O API functions. These functions are thread-safe.
+ *
+ * See include/block/block-io.h for more information about
+ * the I/O API.
+ */
+
+int coroutine_fn bdrv_co_preadv(BdrvChild *child,
+ int64_t offset, int64_t bytes, QEMUIOVector *qiov,
+ BdrvRequestFlags flags);
+int coroutine_fn bdrv_co_preadv_part(BdrvChild *child,
+ int64_t offset, int64_t bytes,
+ QEMUIOVector *qiov, size_t qiov_offset, BdrvRequestFlags flags);
+int coroutine_fn bdrv_co_pwritev(BdrvChild *child,
+ int64_t offset, int64_t bytes, QEMUIOVector *qiov,
+ BdrvRequestFlags flags);
+int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child,
+ int64_t offset, int64_t bytes,
+ QEMUIOVector *qiov, size_t qiov_offset, BdrvRequestFlags flags);
+
+static inline int coroutine_fn bdrv_co_pread(BdrvChild *child,
+ int64_t offset, unsigned int bytes, void *buf, BdrvRequestFlags flags)
+{
+ QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
+
+ return bdrv_co_preadv(child, offset, bytes, &qiov, flags);
+}
+
+static inline int coroutine_fn bdrv_co_pwrite(BdrvChild *child,
+ int64_t offset, unsigned int bytes, void *buf, BdrvRequestFlags flags)
+{
+ QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
+
+ return bdrv_co_pwritev(child, offset, bytes, &qiov, flags);
+}
+
+void bdrv_apply_subtree_drain(BdrvChild *child, BlockDriverState *new_parent);
+void bdrv_unapply_subtree_drain(BdrvChild *child, BlockDriverState *old_parent);
+
+bool coroutine_fn bdrv_make_request_serialising(BdrvTrackedRequest *req,
+ uint64_t align);
+BdrvTrackedRequest *coroutine_fn bdrv_co_get_self_request(BlockDriverState *bs);
+
+/**
+ * bdrv_wakeup:
+ * @bs: The BlockDriverState for which an I/O operation has been completed.
+ *
+ * Wake up the main thread if it is waiting on BDRV_POLL_WHILE. During
+ * synchronous I/O on a BlockDriverState that is attached to another
+ * I/O thread, the main thread lets the I/O thread's event loop run,
+ * waiting for the I/O operation to complete. A bdrv_wakeup will wake
+ * up the main thread if necessary.
+ *
+ * Manual calls to bdrv_wakeup are rarely necessary, because
+ * bdrv_dec_in_flight already calls it.
+ */
+void bdrv_wakeup(BlockDriverState *bs);
+
+const char *bdrv_get_parent_name(const BlockDriverState *bs);
+bool blk_dev_has_tray(BlockBackend *blk);
+bool blk_dev_is_tray_open(BlockBackend *blk);
+
+void bdrv_set_dirty(BlockDriverState *bs, int64_t offset, int64_t bytes);
+
+void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out);
+bool bdrv_dirty_bitmap_merge_internal(BdrvDirtyBitmap *dest,
+ const BdrvDirtyBitmap *src,
+ HBitmap **backup, bool lock);
+
+void bdrv_inc_in_flight(BlockDriverState *bs);
+void bdrv_dec_in_flight(BlockDriverState *bs);
+
+int coroutine_fn bdrv_co_copy_range_from(BdrvChild *src, int64_t src_offset,
+ BdrvChild *dst, int64_t dst_offset,
+ int64_t bytes,
+ BdrvRequestFlags read_flags,
+ BdrvRequestFlags write_flags);
+int coroutine_fn bdrv_co_copy_range_to(BdrvChild *src, int64_t src_offset,
+ BdrvChild *dst, int64_t dst_offset,
+ int64_t bytes,
+ BdrvRequestFlags read_flags,
+ BdrvRequestFlags write_flags);
+
+int refresh_total_sectors(BlockDriverState *bs, int64_t hint);
+
+BdrvChild *bdrv_cow_child(BlockDriverState *bs);
+BdrvChild *bdrv_filter_child(BlockDriverState *bs);
+BdrvChild *bdrv_filter_or_cow_child(BlockDriverState *bs);
+BdrvChild *bdrv_primary_child(BlockDriverState *bs);
+BlockDriverState *bdrv_skip_filters(BlockDriverState *bs);
+BlockDriverState *bdrv_backing_chain_next(BlockDriverState *bs);
+
+static inline BlockDriverState *bdrv_cow_bs(BlockDriverState *bs)
+{
+ return child_bs(bdrv_cow_child(bs));
+}
+
+static inline BlockDriverState *bdrv_filter_bs(BlockDriverState *bs)
+{
+ return child_bs(bdrv_filter_child(bs));
+}
+
+static inline BlockDriverState *bdrv_filter_or_cow_bs(BlockDriverState *bs)
+{
+ return child_bs(bdrv_filter_or_cow_child(bs));
+}
+
+static inline BlockDriverState *bdrv_primary_bs(BlockDriverState *bs)
+{
+ return child_bs(bdrv_primary_child(bs));
+}
+
+/**
+ * Check whether the given offset is in the cached block-status data
+ * region.
+ *
+ * If it is, and @pnum is not NULL, *pnum is set to
+ * `bsc.data_end - offset`, i.e. how many bytes, starting from
+ * @offset, are data (according to the cache).
+ * Otherwise, *pnum is not touched.
+ */
+bool bdrv_bsc_is_data(BlockDriverState *bs, int64_t offset, int64_t *pnum);
+
+/**
+ * If [offset, offset + bytes) overlaps with the currently cached
+ * block-status region, invalidate the cache.
+ *
+ * (To be used by I/O paths that cause data regions to be zero or
+ * holes.)
+ */
+void bdrv_bsc_invalidate_range(BlockDriverState *bs,
+ int64_t offset, int64_t bytes);
+
+/**
+ * Mark the range [offset, offset + bytes) as a data region.
+ */
+void bdrv_bsc_fill(BlockDriverState *bs, int64_t offset, int64_t bytes);
+
+#endif /* BLOCK_INT_IO_H */
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 27008cfb22..7d50b6bbd1 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -24,1478 +24,9 @@
#ifndef BLOCK_INT_H
#define BLOCK_INT_H
-#include "block/accounting.h"
-#include "block/block.h"
-#include "block/aio-wait.h"
-#include "qemu/queue.h"
-#include "qemu/coroutine.h"
-#include "qemu/stats64.h"
-#include "qemu/timer.h"
-#include "qemu/hbitmap.h"
-#include "block/snapshot.h"
-#include "qemu/throttle.h"
-#include "qemu/rcu.h"
+#include "block_int-global-state.h"
+#include "block_int-io.h"
-#define BLOCK_FLAG_LAZY_REFCOUNTS 8
-
-#define BLOCK_OPT_SIZE "size"
-#define BLOCK_OPT_ENCRYPT "encryption"
-#define BLOCK_OPT_ENCRYPT_FORMAT "encrypt.format"
-#define BLOCK_OPT_COMPAT6 "compat6"
-#define BLOCK_OPT_HWVERSION "hwversion"
-#define BLOCK_OPT_BACKING_FILE "backing_file"
-#define BLOCK_OPT_BACKING_FMT "backing_fmt"
-#define BLOCK_OPT_CLUSTER_SIZE "cluster_size"
-#define BLOCK_OPT_TABLE_SIZE "table_size"
-#define BLOCK_OPT_PREALLOC "preallocation"
-#define BLOCK_OPT_SUBFMT "subformat"
-#define BLOCK_OPT_COMPAT_LEVEL "compat"
-#define BLOCK_OPT_LAZY_REFCOUNTS "lazy_refcounts"
-#define BLOCK_OPT_ADAPTER_TYPE "adapter_type"
-#define BLOCK_OPT_REDUNDANCY "redundancy"
-#define BLOCK_OPT_NOCOW "nocow"
-#define BLOCK_OPT_EXTENT_SIZE_HINT "extent_size_hint"
-#define BLOCK_OPT_OBJECT_SIZE "object_size"
-#define BLOCK_OPT_REFCOUNT_BITS "refcount_bits"
-#define BLOCK_OPT_DATA_FILE "data_file"
-#define BLOCK_OPT_DATA_FILE_RAW "data_file_raw"
-#define BLOCK_OPT_COMPRESSION_TYPE "compression_type"
-#define BLOCK_OPT_EXTL2 "extended_l2"
-
-#define BLOCK_PROBE_BUF_SIZE 512
-
-enum BdrvTrackedRequestType {
- BDRV_TRACKED_READ,
- BDRV_TRACKED_WRITE,
- BDRV_TRACKED_DISCARD,
- BDRV_TRACKED_TRUNCATE,
-};
-
-/*
- * That is not quite good that BdrvTrackedRequest structure is public,
- * as block/io.c is very careful about incoming offset/bytes being
- * correct. Be sure to assert bdrv_check_request() succeeded after any
- * modification of BdrvTrackedRequest object out of block/io.c
- */
-typedef struct BdrvTrackedRequest {
- BlockDriverState *bs;
- int64_t offset;
- int64_t bytes;
- enum BdrvTrackedRequestType type;
-
- bool serialising;
- int64_t overlap_offset;
- int64_t overlap_bytes;
-
- QLIST_ENTRY(BdrvTrackedRequest) list;
- Coroutine *co; /* owner, used for deadlock detection */
- CoQueue wait_queue; /* coroutines blocked on this request */
-
- struct BdrvTrackedRequest *waiting_for;
-} BdrvTrackedRequest;
-
-int bdrv_check_qiov_request(int64_t offset, int64_t bytes,
- QEMUIOVector *qiov, size_t qiov_offset,
- Error **errp);
-int bdrv_check_request(int64_t offset, int64_t bytes, Error **errp);
-
-struct BlockDriver {
- const char *format_name;
- int instance_size;
-
- /* set to true if the BlockDriver is a block filter. Block filters pass
- * certain callbacks that refer to data (see block.c) to their bs->file
- * or bs->backing (whichever one exists) if the driver doesn't implement
- * them. Drivers that do not wish to forward must implement them and return
- * -ENOTSUP.
- * Note that filters are not allowed to modify data.
- *
- * Filters generally cannot have more than a single filtered child,
- * because the data they present must at all times be the same as
- * that on their filtered child. That would be impossible to
- * achieve for multiple filtered children.
- * (And this filtered child must then be bs->file or bs->backing.)
- */
- bool is_filter;
- /*
- * Set to true if the BlockDriver is a format driver. Format nodes
- * generally do not expect their children to be other format nodes
- * (except for backing files), and so format probing is disabled
- * on those children.
- */
- bool is_format;
- /*
- * Return true if @to_replace can be replaced by a BDS with the
- * same data as @bs without it affecting @bs's behavior (that is,
- * without it being visible to @bs's parents).
- */
- bool (*bdrv_recurse_can_replace)(BlockDriverState *bs,
- BlockDriverState *to_replace);
-
- int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
- int (*bdrv_probe_device)(const char *filename);
-
- /* Any driver implementing this callback is expected to be able to handle
- * NULL file names in its .bdrv_open() implementation */
- void (*bdrv_parse_filename)(const char *filename, QDict *options, Error **errp);
- /* Drivers not implementing bdrv_parse_filename nor bdrv_open should have
- * this field set to true, except ones that are defined only by their
- * child's bs.
- * An example of the last type will be the quorum block driver.
- */
- bool bdrv_needs_filename;
-
- /*
- * Set if a driver can support backing files. This also implies the
- * following semantics:
- *
- * - Return status 0 of .bdrv_co_block_status means that corresponding
- * blocks are not allocated in this layer of backing-chain
- * - For such (unallocated) blocks, read will:
- * - fill buffer with zeros if there is no backing file
- * - read from the backing file otherwise, where the block layer
- * takes care of reading zeros beyond EOF if backing file is short
- */
- bool supports_backing;
-
- /* For handling image reopen for split or non-split files */
- int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state,
- BlockReopenQueue *queue, Error **errp);
- void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state);
- void (*bdrv_reopen_commit_post)(BDRVReopenState *reopen_state);
- void (*bdrv_reopen_abort)(BDRVReopenState *reopen_state);
- void (*bdrv_join_options)(QDict *options, QDict *old_options);
-
- int (*bdrv_open)(BlockDriverState *bs, QDict *options, int flags,
- Error **errp);
-
- /* Protocol drivers should implement this instead of bdrv_open */
- int (*bdrv_file_open)(BlockDriverState *bs, QDict *options, int flags,
- Error **errp);
- void (*bdrv_close)(BlockDriverState *bs);
-
-
- int coroutine_fn (*bdrv_co_create)(BlockdevCreateOptions *opts,
- Error **errp);
- int coroutine_fn (*bdrv_co_create_opts)(BlockDriver *drv,
- const char *filename,
- QemuOpts *opts,
- Error **errp);
-
- int coroutine_fn (*bdrv_co_amend)(BlockDriverState *bs,
- BlockdevAmendOptions *opts,
- bool force,
- Error **errp);
-
- int (*bdrv_amend_options)(BlockDriverState *bs,
- QemuOpts *opts,
- BlockDriverAmendStatusCB *status_cb,
- void *cb_opaque,
- bool force,
- Error **errp);
-
- int (*bdrv_make_empty)(BlockDriverState *bs);
-
- /*
- * Refreshes the bs->exact_filename field. If that is impossible,
- * bs->exact_filename has to be left empty.
- */
- void (*bdrv_refresh_filename)(BlockDriverState *bs);
-
- /*
- * Gathers the open options for all children into @target.
- * A simple format driver (without backing file support) might
- * implement this function like this:
- *
- * QINCREF(bs->file->bs->full_open_options);
- * qdict_put(target, "file", bs->file->bs->full_open_options);
- *
- * If not specified, the generic implementation will simply put
- * all children's options under their respective name.
- *
- * @backing_overridden is true when bs->backing seems not to be
- * the child that would result from opening bs->backing_file.
- * Therefore, if it is true, the backing child's options should be
- * gathered; otherwise, there is no need since the backing child
- * is the one implied by the image header.
- *
- * Note that ideally this function would not be needed. Every
- * block driver which implements it is probably doing something
- * shady regarding its runtime option structure.
- */
- void (*bdrv_gather_child_options)(BlockDriverState *bs, QDict *target,
- bool backing_overridden);
-
- /*
- * Returns an allocated string which is the directory name of this BDS: It
- * will be used to make relative filenames absolute by prepending this
- * function's return value to them.
- */
- char *(*bdrv_dirname)(BlockDriverState *bs, Error **errp);
-
- /* aio */
- BlockAIOCB *(*bdrv_aio_preadv)(BlockDriverState *bs,
- int64_t offset, int64_t bytes, QEMUIOVector *qiov,
- BdrvRequestFlags flags, BlockCompletionFunc *cb, void *opaque);
- BlockAIOCB *(*bdrv_aio_pwritev)(BlockDriverState *bs,
- int64_t offset, int64_t bytes, QEMUIOVector *qiov,
- BdrvRequestFlags flags, BlockCompletionFunc *cb, void *opaque);
- BlockAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
- BlockCompletionFunc *cb, void *opaque);
- BlockAIOCB *(*bdrv_aio_pdiscard)(BlockDriverState *bs,
- int64_t offset, int bytes,
- BlockCompletionFunc *cb, void *opaque);
-
- int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
-
- /**
- * @offset: position in bytes to read at
- * @bytes: number of bytes to read
- * @qiov: the buffers to fill with read data
- * @flags: currently unused, always 0
- *
- * @offset and @bytes will be a multiple of 'request_alignment',
- * but the length of individual @qiov elements does not have to
- * be a multiple.
- *
- * @bytes will always equal the total size of @qiov, and will be
- * no larger than 'max_transfer'.
- *
- * The buffer in @qiov may point directly to guest memory.
- */
- int coroutine_fn (*bdrv_co_preadv)(BlockDriverState *bs,
- int64_t offset, int64_t bytes, QEMUIOVector *qiov,
- BdrvRequestFlags flags);
- int coroutine_fn (*bdrv_co_preadv_part)(BlockDriverState *bs,
- int64_t offset, int64_t bytes,
- QEMUIOVector *qiov, size_t qiov_offset, BdrvRequestFlags flags);
- int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, int flags);
- /**
- * @offset: position in bytes to write at
- * @bytes: number of bytes to write
- * @qiov: the buffers containing data to write
- * @flags: zero or more bits allowed by 'supported_write_flags'
- *
- * @offset and @bytes will be a multiple of 'request_alignment',
- * but the length of individual @qiov elements does not have to
- * be a multiple.
- *
- * @bytes will always equal the total size of @qiov, and will be
- * no larger than 'max_transfer'.
- *
- * The buffer in @qiov may point directly to guest memory.
- */
- int coroutine_fn (*bdrv_co_pwritev)(BlockDriverState *bs,
- int64_t offset, int64_t bytes, QEMUIOVector *qiov,
- BdrvRequestFlags flags);
- int coroutine_fn (*bdrv_co_pwritev_part)(BlockDriverState *bs,
- int64_t offset, int64_t bytes, QEMUIOVector *qiov, size_t qiov_offset,
- BdrvRequestFlags flags);
-
- /*
- * Efficiently zero a region of the disk image. Typically an image format
- * would use a compact metadata representation to implement this. This
- * function pointer may be NULL or return -ENOSUP and .bdrv_co_writev()
- * will be called instead.
- */
- int coroutine_fn (*bdrv_co_pwrite_zeroes)(BlockDriverState *bs,
- int64_t offset, int64_t bytes, BdrvRequestFlags flags);
- int coroutine_fn (*bdrv_co_pdiscard)(BlockDriverState *bs,
- int64_t offset, int64_t bytes);
-
- /* Map [offset, offset + nbytes) range onto a child of @bs to copy from,
- * and invoke bdrv_co_copy_range_from(child, ...), or invoke
- * bdrv_co_copy_range_to() if @bs is the leaf child to copy data from.
- *
- * See the comment of bdrv_co_copy_range for the parameter and return value
- * semantics.
- */
- int coroutine_fn (*bdrv_co_copy_range_from)(BlockDriverState *bs,
- BdrvChild *src,
- int64_t offset,
- BdrvChild *dst,
- int64_t dst_offset,
- int64_t bytes,
- BdrvRequestFlags read_flags,
- BdrvRequestFlags write_flags);
-
- /* Map [offset, offset + nbytes) range onto a child of bs to copy data to,
- * and invoke bdrv_co_copy_range_to(child, src, ...), or perform the copy
- * operation if @bs is the leaf and @src has the same BlockDriver. Return
- * -ENOTSUP if @bs is the leaf but @src has a different BlockDriver.
- *
- * See the comment of bdrv_co_copy_range for the parameter and return value
- * semantics.
- */
- int coroutine_fn (*bdrv_co_copy_range_to)(BlockDriverState *bs,
- BdrvChild *src,
- int64_t src_offset,
- BdrvChild *dst,
- int64_t dst_offset,
- int64_t bytes,
- BdrvRequestFlags read_flags,
- BdrvRequestFlags write_flags);
-
- /*
- * Building block for bdrv_block_status[_above] and
- * bdrv_is_allocated[_above]. The driver should answer only
- * according to the current layer, and should only need to set
- * BDRV_BLOCK_DATA, BDRV_BLOCK_ZERO, BDRV_BLOCK_OFFSET_VALID,
- * and/or BDRV_BLOCK_RAW; if the current layer defers to a backing
- * layer, the result should be 0 (and not BDRV_BLOCK_ZERO). See
- * block.h for the overall meaning of the bits. As a hint, the
- * flag want_zero is true if the caller cares more about precise
- * mappings (favor accurate _OFFSET_VALID/_ZERO) or false for
- * overall allocation (favor larger *pnum, perhaps by reporting
- * _DATA instead of _ZERO). The block layer guarantees input
- * clamped to bdrv_getlength() and aligned to request_alignment,
- * as well as non-NULL pnum, map, and file; in turn, the driver
- * must return an error or set pnum to an aligned non-zero value.
- *
- * Note that @bytes is just a hint on how big of a region the
- * caller wants to inspect. It is not a limit on *pnum.
- * Implementations are free to return larger values of *pnum if
- * doing so does not incur a performance penalty.
- *
- * block/io.c's bdrv_co_block_status() will utilize an unclamped
- * *pnum value for the block-status cache on protocol nodes, prior
- * to clamping *pnum for return to its caller.
- */
- int coroutine_fn (*bdrv_co_block_status)(BlockDriverState *bs,
- bool want_zero, int64_t offset, int64_t bytes, int64_t *pnum,
- int64_t *map, BlockDriverState **file);
-
- /*
- * This informs the driver that we are no longer interested in the result
- * of in-flight requests, so don't waste the time if possible.
- *
- * One example usage is to avoid waiting for an nbd target node reconnect
- * timeout during job-cancel with force=true.
- */
- void (*bdrv_cancel_in_flight)(BlockDriverState *bs);
-
- /*
- * Invalidate any cached meta-data.
- */
- void coroutine_fn (*bdrv_co_invalidate_cache)(BlockDriverState *bs,
- Error **errp);
- int (*bdrv_inactivate)(BlockDriverState *bs);
-
- /*
- * Flushes all data for all layers by calling bdrv_co_flush for underlying
- * layers, if needed. This function is needed for deterministic
- * synchronization of the flush finishing callback.
- */
- int coroutine_fn (*bdrv_co_flush)(BlockDriverState *bs);
-
- /* Delete a created file. */
- int coroutine_fn (*bdrv_co_delete_file)(BlockDriverState *bs,
- Error **errp);
-
- /*
- * Flushes all data that was already written to the OS all the way down to
- * the disk (for example file-posix.c calls fsync()).
- */
- int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs);
-
- /*
- * Flushes all internal caches to the OS. The data may still sit in a
- * writeback cache of the host OS, but it will survive a crash of the qemu
- * process.
- */
- int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);
-
- /*
- * Drivers setting this field must be able to work with just a plain
- * filename with '<protocol_name>:' as a prefix, and no other options.
- * Options may be extracted from the filename by implementing
- * bdrv_parse_filename.
- */
- const char *protocol_name;
-
- /*
- * Truncate @bs to @offset bytes using the given @prealloc mode
- * when growing. Modes other than PREALLOC_MODE_OFF should be
- * rejected when shrinking @bs.
- *
- * If @exact is true, @bs must be resized to exactly @offset.
- * Otherwise, it is sufficient for @bs (if it is a host block
- * device and thus there is no way to resize it) to be at least
- * @offset bytes in length.
- *
- * If @exact is true and this function fails but would succeed
- * with @exact = false, it should return -ENOTSUP.
- */
- int coroutine_fn (*bdrv_co_truncate)(BlockDriverState *bs, int64_t offset,
- bool exact, PreallocMode prealloc,
- BdrvRequestFlags flags, Error **errp);
-
- int64_t (*bdrv_getlength)(BlockDriverState *bs);
- bool has_variable_length;
- int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);
- BlockMeasureInfo *(*bdrv_measure)(QemuOpts *opts, BlockDriverState *in_bs,
- Error **errp);
-
- int coroutine_fn (*bdrv_co_pwritev_compressed)(BlockDriverState *bs,
- int64_t offset, int64_t bytes, QEMUIOVector *qiov);
- int coroutine_fn (*bdrv_co_pwritev_compressed_part)(BlockDriverState *bs,
- int64_t offset, int64_t bytes, QEMUIOVector *qiov, size_t qiov_offset);
-
- int (*bdrv_snapshot_create)(BlockDriverState *bs,
- QEMUSnapshotInfo *sn_info);
- int (*bdrv_snapshot_goto)(BlockDriverState *bs,
- const char *snapshot_id);
- int (*bdrv_snapshot_delete)(BlockDriverState *bs,
- const char *snapshot_id,
- const char *name,
- Error **errp);
- int (*bdrv_snapshot_list)(BlockDriverState *bs,
- QEMUSnapshotInfo **psn_info);
- int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
- const char *snapshot_id,
- const char *name,
- Error **errp);
- int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
- ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs,
- Error **errp);
- BlockStatsSpecific *(*bdrv_get_specific_stats)(BlockDriverState *bs);
-
- int coroutine_fn (*bdrv_save_vmstate)(BlockDriverState *bs,
- QEMUIOVector *qiov,
- int64_t pos);
- int coroutine_fn (*bdrv_load_vmstate)(BlockDriverState *bs,
- QEMUIOVector *qiov,
- int64_t pos);
-
- int (*bdrv_change_backing_file)(BlockDriverState *bs,
- const char *backing_file, const char *backing_fmt);
-
- /* removable device specific */
- bool (*bdrv_is_inserted)(BlockDriverState *bs);
- void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
- void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
-
- /* to control generic scsi devices */
- BlockAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
- unsigned long int req, void *buf,
- BlockCompletionFunc *cb, void *opaque);
- int coroutine_fn (*bdrv_co_ioctl)(BlockDriverState *bs,
- unsigned long int req, void *buf);
-
- /* List of options for creating images, terminated by name == NULL */
- QemuOptsList *create_opts;
-
- /* List of options for image amend */
- QemuOptsList *amend_opts;
-
- /*
- * If this driver supports reopening images this contains a
- * NULL-terminated list of the runtime options that can be
- * modified. If an option in this list is unspecified during
- * reopen then it _must_ be reset to its default value or return
- * an error.
- */
- const char *const *mutable_opts;
-
- /*
- * Returns 0 for completed check, -errno for internal errors.
- * The check results are stored in result.
- */
- int coroutine_fn (*bdrv_co_check)(BlockDriverState *bs,
- BdrvCheckResult *result,
- BdrvCheckMode fix);
-
- void (*bdrv_debug_event)(BlockDriverState *bs, BlkdebugEvent event);
-
- /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */
- int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event,
- const char *tag);
- int (*bdrv_debug_remove_breakpoint)(BlockDriverState *bs,
- const char *tag);
- int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag);
- bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag);
-
- void (*bdrv_refresh_limits)(BlockDriverState *bs, Error **errp);
-
- /*
- * Returns 1 if newly created images are guaranteed to contain only
- * zeros, 0 otherwise.
- */
- int (*bdrv_has_zero_init)(BlockDriverState *bs);
-
- /* Remove fd handlers, timers, and other event loop callbacks so the event
- * loop is no longer in use. Called with no in-flight requests and in
- * depth-first traversal order with parents before child nodes.
- */
- void (*bdrv_detach_aio_context)(BlockDriverState *bs);
-
- /* Add fd handlers, timers, and other event loop callbacks so I/O requests
- * can be processed again. Called with no in-flight requests and in
- * depth-first traversal order with child nodes before parent nodes.
- */
- void (*bdrv_attach_aio_context)(BlockDriverState *bs,
- AioContext *new_context);
-
- /* io queue for linux-aio */
- void (*bdrv_io_plug)(BlockDriverState *bs);
- void (*bdrv_io_unplug)(BlockDriverState *bs);
-
- /**
- * Try to get @bs's logical and physical block size.
- * On success, store them in @bsz and return zero.
- * On failure, return negative errno.
- */
- int (*bdrv_probe_blocksizes)(BlockDriverState *bs, BlockSizes *bsz);
- /**
- * Try to get @bs's geometry (cyls, heads, sectors)
- * On success, store them in @geo and return 0.
- * On failure return -errno.
- * Only drivers that want to override guest geometry implement this
- * callback; see hd_geometry_guess().
- */
- int (*bdrv_probe_geometry)(BlockDriverState *bs, HDGeometry *geo);
-
- /**
- * bdrv_co_drain_begin is called if implemented in the beginning of a
- * drain operation to drain and stop any internal sources of requests in
- * the driver.
- * bdrv_co_drain_end is called if implemented at the end of the drain.
- *
- * They should be used by the driver to e.g. manage scheduled I/O
- * requests, or toggle an internal state. After the end of the drain new
- * requests will continue normally.
- */
- void coroutine_fn (*bdrv_co_drain_begin)(BlockDriverState *bs);
- void coroutine_fn (*bdrv_co_drain_end)(BlockDriverState *bs);
-
- void (*bdrv_add_child)(BlockDriverState *parent, BlockDriverState *child,
- Error **errp);
- void (*bdrv_del_child)(BlockDriverState *parent, BdrvChild *child,
- Error **errp);
-
- /**
- * Informs the block driver that a permission change is intended. The
- * driver checks whether the change is permissible and may take other
- * preparations for the change (e.g. get file system locks). This operation
- * is always followed either by a call to either .bdrv_set_perm or
- * .bdrv_abort_perm_update.
- *
- * Checks whether the requested set of cumulative permissions in @perm
- * can be granted for accessing @bs and whether no other users are using
- * permissions other than those given in @shared (both arguments take
- * BLK_PERM_* bitmasks).
- *
- * If both conditions are met, 0 is returned. Otherwise, -errno is returned
- * and errp is set to an error describing the conflict.
- */
- int (*bdrv_check_perm)(BlockDriverState *bs, uint64_t perm,
- uint64_t shared, Error **errp);
-
- /**
- * Called to inform the driver that the set of cumulative set of used
- * permissions for @bs has changed to @perm, and the set of sharable
- * permission to @shared. The driver can use this to propagate changes to
- * its children (i.e. request permissions only if a parent actually needs
- * them).
- *
- * This function is only invoked after bdrv_check_perm(), so block drivers
- * may rely on preparations made in their .bdrv_check_perm implementation.
- */
- void (*bdrv_set_perm)(BlockDriverState *bs, uint64_t perm, uint64_t shared);
-
- /*
- * Called to inform the driver that after a previous bdrv_check_perm()
- * call, the permission update is not performed and any preparations made
- * for it (e.g. taken file locks) need to be undone.
- *
- * This function can be called even for nodes that never saw a
- * bdrv_check_perm() call. It is a no-op then.
- */
- void (*bdrv_abort_perm_update)(BlockDriverState *bs);
-
- /**
- * Returns in @nperm and @nshared the permissions that the driver for @bs
- * needs on its child @c, based on the cumulative permissions requested by
- * the parents in @parent_perm and @parent_shared.
- *
- * If @c is NULL, return the permissions for attaching a new child for the
- * given @child_class and @role.
- *
- * If @reopen_queue is non-NULL, don't return the currently needed
- * permissions, but those that will be needed after applying the
- * @reopen_queue.
- */
- void (*bdrv_child_perm)(BlockDriverState *bs, BdrvChild *c,
- BdrvChildRole role,
- BlockReopenQueue *reopen_queue,
- uint64_t parent_perm, uint64_t parent_shared,
- uint64_t *nperm, uint64_t *nshared);
-
- bool (*bdrv_supports_persistent_dirty_bitmap)(BlockDriverState *bs);
- bool (*bdrv_co_can_store_new_dirty_bitmap)(BlockDriverState *bs,
- const char *name,
- uint32_t granularity,
- Error **errp);
- int (*bdrv_co_remove_persistent_dirty_bitmap)(BlockDriverState *bs,
- const char *name,
- Error **errp);
-
- /**
- * Register/unregister a buffer for I/O. For example, when the driver is
- * interested to know the memory areas that will later be used in iovs, so
- * that it can do IOMMU mapping with VFIO etc., in order to get better
- * performance. In the case of VFIO drivers, this callback is used to do
- * DMA mapping for hot buffers.
- */
- void (*bdrv_register_buf)(BlockDriverState *bs, void *host, size_t size);
- void (*bdrv_unregister_buf)(BlockDriverState *bs, void *host);
- QLIST_ENTRY(BlockDriver) list;
-
- /* Pointer to a NULL-terminated array of names of strong options
- * that can be specified for bdrv_open(). A strong option is one
- * that changes the data of a BDS.
- * If this pointer is NULL, the array is considered empty.
- * "filename" and "driver" are always considered strong. */
- const char *const *strong_runtime_opts;
-};
-
-static inline bool block_driver_can_compress(BlockDriver *drv)
-{
- return drv->bdrv_co_pwritev_compressed ||
- drv->bdrv_co_pwritev_compressed_part;
-}
-
-typedef struct BlockLimits {
- /* Alignment requirement, in bytes, for offset/length of I/O
- * requests. Must be a power of 2 less than INT_MAX; defaults to
- * 1 for drivers with modern byte interfaces, and to 512
- * otherwise. */
- uint32_t request_alignment;
-
- /*
- * Maximum number of bytes that can be discarded at once. Must be multiple
- * of pdiscard_alignment, but need not be power of 2. May be 0 if no
- * inherent 64-bit limit.
- */
- int64_t max_pdiscard;
-
- /* Optimal alignment for discard requests in bytes. A power of 2
- * is best but not mandatory. Must be a multiple of
- * bl.request_alignment, and must be less than max_pdiscard if
- * that is set. May be 0 if bl.request_alignment is good enough */
- uint32_t pdiscard_alignment;
-
- /*
- * Maximum number of bytes that can zeroized at once. Must be multiple of
- * pwrite_zeroes_alignment. 0 means no limit.
- */
- int64_t max_pwrite_zeroes;
-
- /* Optimal alignment for write zeroes requests in bytes. A power
- * of 2 is best but not mandatory. Must be a multiple of
- * bl.request_alignment, and must be less than max_pwrite_zeroes
- * if that is set. May be 0 if bl.request_alignment is good
- * enough */
- uint32_t pwrite_zeroes_alignment;
-
- /* Optimal transfer length in bytes. A power of 2 is best but not
- * mandatory. Must be a multiple of bl.request_alignment, or 0 if
- * no preferred size */
- uint32_t opt_transfer;
-
- /* Maximal transfer length in bytes. Need not be power of 2, but
- * must be multiple of opt_transfer and bl.request_alignment, or 0
- * for no 32-bit limit. For now, anything larger than INT_MAX is
- * clamped down. */
- uint32_t max_transfer;
-
- /* Maximal hardware transfer length in bytes. Applies whenever
- * transfers to the device bypass the kernel I/O scheduler, for
- * example with SG_IO. If larger than max_transfer or if zero,
- * blk_get_max_hw_transfer will fall back to max_transfer.
- */
- uint64_t max_hw_transfer;
-
- /* Maximal number of scatter/gather elements allowed by the hardware.
- * Applies whenever transfers to the device bypass the kernel I/O
- * scheduler, for example with SG_IO. If larger than max_iov
- * or if zero, blk_get_max_hw_iov will fall back to max_iov.
- */
- int max_hw_iov;
-
- /* memory alignment, in bytes so that no bounce buffer is needed */
- size_t min_mem_alignment;
-
- /* memory alignment, in bytes, for bounce buffer */
- size_t opt_mem_alignment;
-
- /* maximum number of iovec elements */
- int max_iov;
-} BlockLimits;
-
-typedef struct BdrvOpBlocker BdrvOpBlocker;
-
-typedef struct BdrvAioNotifier {
- void (*attached_aio_context)(AioContext *new_context, void *opaque);
- void (*detach_aio_context)(void *opaque);
-
- void *opaque;
- bool deleted;
-
- QLIST_ENTRY(BdrvAioNotifier) list;
-} BdrvAioNotifier;
-
-struct BdrvChildClass {
- /* If true, bdrv_replace_node() doesn't change the node this BdrvChild
- * points to. */
- bool stay_at_node;
-
- /* If true, the parent is a BlockDriverState and bdrv_next_all_states()
- * will return it. This information is used for drain_all, where every node
- * will be drained separately, so the drain only needs to be propagated to
- * non-BDS parents. */
- bool parent_is_bds;
-
- void (*inherit_options)(BdrvChildRole role, bool parent_is_format,
- int *child_flags, QDict *child_options,
- int parent_flags, QDict *parent_options);
-
- void (*change_media)(BdrvChild *child, bool load);
- void (*resize)(BdrvChild *child);
-
- /* Returns a name that is supposedly more useful for human users than the
- * node name for identifying the node in question (in particular, a BB
- * name), or NULL if the parent can't provide a better name. */
- const char *(*get_name)(BdrvChild *child);
-
- /* Returns a malloced string that describes the parent of the child for a
- * human reader. This could be a node-name, BlockBackend name, qdev ID or
- * QOM path of the device owning the BlockBackend, job type and ID etc. The
- * caller is responsible for freeing the memory. */
- char *(*get_parent_desc)(BdrvChild *child);
-
- /*
- * If this pair of functions is implemented, the parent doesn't issue new
- * requests after returning from .drained_begin() until .drained_end() is
- * called.
- *
- * These functions must not change the graph (and therefore also must not
- * call aio_poll(), which could change the graph indirectly).
- *
- * If drained_end() schedules background operations, it must atomically
- * increment *drained_end_counter for each such operation and atomically
- * decrement it once the operation has settled.
- *
- * Note that this can be nested. If drained_begin() was called twice, new
- * I/O is allowed only after drained_end() was called twice, too.
- */
- void (*drained_begin)(BdrvChild *child);
- void (*drained_end)(BdrvChild *child, int *drained_end_counter);
-
- /*
- * Returns whether the parent has pending requests for the child. This
- * callback is polled after .drained_begin() has been called until all
- * activity on the child has stopped.
- */
- bool (*drained_poll)(BdrvChild *child);
-
- /* Notifies the parent that the child has been activated/inactivated (e.g.
- * when migration is completing) and it can start/stop requesting
- * permissions and doing I/O on it. */
- void (*activate)(BdrvChild *child, Error **errp);
- int (*inactivate)(BdrvChild *child);
-
- void (*attach)(BdrvChild *child);
- void (*detach)(BdrvChild *child);
-
- /* Notifies the parent that the filename of its child has changed (e.g.
- * because the direct child was removed from the backing chain), so that it
- * can update its reference. */
- int (*update_filename)(BdrvChild *child, BlockDriverState *new_base,
- const char *filename, Error **errp);
-
- bool (*can_set_aio_ctx)(BdrvChild *child, AioContext *ctx,
- GSList **ignore, Error **errp);
- void (*set_aio_ctx)(BdrvChild *child, AioContext *ctx, GSList **ignore);
-
- AioContext *(*get_parent_aio_context)(BdrvChild *child);
-};
-
-extern const BdrvChildClass child_of_bds;
-
-struct BdrvChild {
- BlockDriverState *bs;
- char *name;
- const BdrvChildClass *klass;
- BdrvChildRole role;
- void *opaque;
-
- /**
- * Granted permissions for operating on this BdrvChild (BLK_PERM_* bitmask)
- */
- uint64_t perm;
-
- /**
- * Permissions that can still be granted to other users of @bs while this
- * BdrvChild is still attached to it. (BLK_PERM_* bitmask)
- */
- uint64_t shared_perm;
-
- /*
- * This link is frozen: the child can neither be replaced nor
- * detached from the parent.
- */
- bool frozen;
-
- /*
- * How many times the parent of this child has been drained
- * (through klass->drained_*).
- * Usually, this is equal to bs->quiesce_counter (potentially
- * reduced by bdrv_drain_all_count). It may differ while the
- * child is entering or leaving a drained section.
- */
- int parent_quiesce_counter;
-
- QLIST_ENTRY(BdrvChild) next;
- QLIST_ENTRY(BdrvChild) next_parent;
-};
-
-/*
- * Allows bdrv_co_block_status() to cache one data region for a
- * protocol node.
- *
- * @valid: Whether the cache is valid (should be accessed with atomic
- * functions so this can be reset by RCU readers)
- * @data_start: Offset where we know (or strongly assume) is data
- * @data_end: Offset where the data region ends (which is not necessarily
- * the start of a zeroed region)
- */
-typedef struct BdrvBlockStatusCache {
- struct rcu_head rcu;
-
- bool valid;
- int64_t data_start;
- int64_t data_end;
-} BdrvBlockStatusCache;
-
-struct BlockDriverState {
- /* Protected by big QEMU lock or read-only after opening. No special
- * locking needed during I/O...
- */
- int open_flags; /* flags used to open the file, re-used for re-open */
- bool encrypted; /* if true, the media is encrypted */
- bool sg; /* if true, the device is a /dev/sg* */
- bool probed; /* if true, format was probed rather than specified */
- bool force_share; /* if true, always allow all shared permissions */
- bool implicit; /* if true, this filter node was automatically inserted */
-
- BlockDriver *drv; /* NULL means no media */
- void *opaque;
-
- AioContext *aio_context; /* event loop used for fd handlers, timers, etc */
- /* long-running tasks intended to always use the same AioContext as this
- * BDS may register themselves in this list to be notified of changes
- * regarding this BDS's context */
- QLIST_HEAD(, BdrvAioNotifier) aio_notifiers;
- bool walking_aio_notifiers; /* to make removal during iteration safe */
-
- char filename[PATH_MAX];
- /*
- * If not empty, this image is a diff in relation to backing_file.
- * Note that this is the name given in the image header and
- * therefore may or may not be equal to .backing->bs->filename.
- * If this field contains a relative path, it is to be resolved
- * relatively to the overlay's location.
- */
- char backing_file[PATH_MAX];
- /*
- * The backing filename indicated by the image header. Contrary
- * to backing_file, if we ever open this file, auto_backing_file
- * is replaced by the resulting BDS's filename (i.e. after a
- * bdrv_refresh_filename() run).
- */
- char auto_backing_file[PATH_MAX];
- char backing_format[16]; /* if non-zero and backing_file exists */
-
- QDict *full_open_options;
- char exact_filename[PATH_MAX];
-
- BdrvChild *backing;
- BdrvChild *file;
-
- /* I/O Limits */
- BlockLimits bl;
-
- /*
- * Flags honored during pread
- */
- unsigned int supported_read_flags;
- /* Flags honored during pwrite (so far: BDRV_REQ_FUA,
- * BDRV_REQ_WRITE_UNCHANGED).
- * If a driver does not support BDRV_REQ_WRITE_UNCHANGED, those
- * writes will be issued as normal writes without the flag set.
- * This is important to note for drivers that do not explicitly
- * request a WRITE permission for their children and instead take
- * the same permissions as their parent did (this is commonly what
- * block filters do). Such drivers have to be aware that the
- * parent may have taken a WRITE_UNCHANGED permission only and is
- * issuing such requests. Drivers either must make sure that
- * these requests do not result in plain WRITE accesses (usually
- * by supporting BDRV_REQ_WRITE_UNCHANGED, and then forwarding
- * every incoming write request as-is, including potentially that
- * flag), or they have to explicitly take the WRITE permission for
- * their children. */
- unsigned int supported_write_flags;
- /* Flags honored during pwrite_zeroes (so far: BDRV_REQ_FUA,
- * BDRV_REQ_MAY_UNMAP, BDRV_REQ_WRITE_UNCHANGED) */
- unsigned int supported_zero_flags;
- /*
- * Flags honoured during truncate (so far: BDRV_REQ_ZERO_WRITE).
- *
- * If BDRV_REQ_ZERO_WRITE is given, the truncate operation must make sure
- * that any added space reads as all zeros. If this can't be guaranteed,
- * the operation must fail.
- */
- unsigned int supported_truncate_flags;
-
- /* the following member gives a name to every node on the bs graph. */
- char node_name[32];
- /* element of the list of named nodes building the graph */
- QTAILQ_ENTRY(BlockDriverState) node_list;
- /* element of the list of all BlockDriverStates (all_bdrv_states) */
- QTAILQ_ENTRY(BlockDriverState) bs_list;
- /* element of the list of monitor-owned BDS */
- QTAILQ_ENTRY(BlockDriverState) monitor_list;
- int refcnt;
-
- /* operation blockers */
- QLIST_HEAD(, BdrvOpBlocker) op_blockers[BLOCK_OP_TYPE_MAX];
-
- /* The node that this node inherited default options from (and a reopen on
- * which can affect this node by changing these defaults). This is always a
- * parent node of this node. */
- BlockDriverState *inherits_from;
- QLIST_HEAD(, BdrvChild) children;
- QLIST_HEAD(, BdrvChild) parents;
-
- QDict *options;
- QDict *explicit_options;
- BlockdevDetectZeroesOptions detect_zeroes;
-
- /* The error object in use for blocking operations on backing_hd */
- Error *backing_blocker;
-
- /* Protected by AioContext lock */
-
- /* If we are reading a disk image, give its size in sectors.
- * Generally read-only; it is written to by load_snapshot and
- * save_snaphost, but the block layer is quiescent during those.
- */
- int64_t total_sectors;
-
- /* threshold limit for writes, in bytes. "High water mark". */
- uint64_t write_threshold_offset;
-
- /* Writing to the list requires the BQL _and_ the dirty_bitmap_mutex.
- * Reading from the list can be done with either the BQL or the
- * dirty_bitmap_mutex. Modifying a bitmap only requires
- * dirty_bitmap_mutex. */
- QemuMutex dirty_bitmap_mutex;
- QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps;
-
- /* Offset after the highest byte written to */
- Stat64 wr_highest_offset;
-
- /* If true, copy read backing sectors into image. Can be >1 if more
- * than one client has requested copy-on-read. Accessed with atomic
- * ops.
- */
- int copy_on_read;
-
- /* number of in-flight requests; overall and serialising.
- * Accessed with atomic ops.
- */
- unsigned int in_flight;
- unsigned int serialising_in_flight;
-
- /* counter for nested bdrv_io_plug.
- * Accessed with atomic ops.
- */
- unsigned io_plugged;
-
- /* do we need to tell the quest if we have a volatile write cache? */
- int enable_write_cache;
-
- /* Accessed with atomic ops. */
- int quiesce_counter;
- int recursive_quiesce_counter;
-
- unsigned int write_gen; /* Current data generation */
-
- /* Protected by reqs_lock. */
- CoMutex reqs_lock;
- QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
- CoQueue flush_queue; /* Serializing flush queue */
- bool active_flush_req; /* Flush request in flight? */
-
- /* Only read/written by whoever has set active_flush_req to true. */
- unsigned int flushed_gen; /* Flushed write generation */
-
- /* BdrvChild links to this node may never be frozen */
- bool never_freeze;
-
- /* Lock for block-status cache RCU writers */
- CoMutex bsc_modify_lock;
- /* Always non-NULL, but must only be dereferenced under an RCU read guard */
- BdrvBlockStatusCache *block_status_cache;
-};
-
-struct BlockBackendRootState {
- int open_flags;
- BlockdevDetectZeroesOptions detect_zeroes;
-};
-
-typedef enum BlockMirrorBackingMode {
- /* Reuse the existing backing chain from the source for the target.
- * - sync=full: Set backing BDS to NULL.
- * - sync=top: Use source's backing BDS.
- * - sync=none: Use source as the backing BDS. */
- MIRROR_SOURCE_BACKING_CHAIN,
-
- /* Open the target's backing chain completely anew */
- MIRROR_OPEN_BACKING_CHAIN,
-
- /* Do not change the target's backing BDS after job completion */
- MIRROR_LEAVE_BACKING_CHAIN,
-} BlockMirrorBackingMode;
-
-
-/* Essential block drivers which must always be statically linked into qemu, and
- * which therefore can be accessed without using bdrv_find_format() */
-extern BlockDriver bdrv_file;
-extern BlockDriver bdrv_raw;
-extern BlockDriver bdrv_qcow2;
-
-int coroutine_fn bdrv_co_preadv(BdrvChild *child,
- int64_t offset, int64_t bytes, QEMUIOVector *qiov,
- BdrvRequestFlags flags);
-int coroutine_fn bdrv_co_preadv_part(BdrvChild *child,
- int64_t offset, int64_t bytes,
- QEMUIOVector *qiov, size_t qiov_offset, BdrvRequestFlags flags);
-int coroutine_fn bdrv_co_pwritev(BdrvChild *child,
- int64_t offset, int64_t bytes, QEMUIOVector *qiov,
- BdrvRequestFlags flags);
-int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child,
- int64_t offset, int64_t bytes,
- QEMUIOVector *qiov, size_t qiov_offset, BdrvRequestFlags flags);
-
-static inline int coroutine_fn bdrv_co_pread(BdrvChild *child,
- int64_t offset, unsigned int bytes, void *buf, BdrvRequestFlags flags)
-{
- QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
-
- return bdrv_co_preadv(child, offset, bytes, &qiov, flags);
-}
-
-static inline int coroutine_fn bdrv_co_pwrite(BdrvChild *child,
- int64_t offset, unsigned int bytes, void *buf, BdrvRequestFlags flags)
-{
- QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
-
- return bdrv_co_pwritev(child, offset, bytes, &qiov, flags);
-}
-
-extern unsigned int bdrv_drain_all_count;
-void bdrv_apply_subtree_drain(BdrvChild *child, BlockDriverState *new_parent);
-void bdrv_unapply_subtree_drain(BdrvChild *child, BlockDriverState *old_parent);
-
-bool coroutine_fn bdrv_make_request_serialising(BdrvTrackedRequest *req,
- uint64_t align);
-BdrvTrackedRequest *coroutine_fn bdrv_co_get_self_request(BlockDriverState *bs);
-
-int get_tmp_filename(char *filename, int size);
-BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
- const char *filename);
-
-void bdrv_parse_filename_strip_prefix(const char *filename, const char *prefix,
- QDict *options);
-
-/**
- * bdrv_add_aio_context_notifier:
- *
- * If a long-running job intends to be always run in the same AioContext as a
- * certain BDS, it may use this function to be notified of changes regarding the
- * association of the BDS to an AioContext.
- *
- * attached_aio_context() is called after the target BDS has been attached to a
- * new AioContext; detach_aio_context() is called before the target BDS is being
- * detached from its old AioContext.
- */
-void bdrv_add_aio_context_notifier(BlockDriverState *bs,
- void (*attached_aio_context)(AioContext *new_context, void *opaque),
- void (*detach_aio_context)(void *opaque), void *opaque);
-
-/**
- * bdrv_remove_aio_context_notifier:
- *
- * Unsubscribe of change notifications regarding the BDS's AioContext. The
- * parameters given here have to be the same as those given to
- * bdrv_add_aio_context_notifier().
- */
-void bdrv_remove_aio_context_notifier(BlockDriverState *bs,
- void (*aio_context_attached)(AioContext *,
- void *),
- void (*aio_context_detached)(void *),
- void *opaque);
-
-/**
- * bdrv_wakeup:
- * @bs: The BlockDriverState for which an I/O operation has been completed.
- *
- * Wake up the main thread if it is waiting on BDRV_POLL_WHILE. During
- * synchronous I/O on a BlockDriverState that is attached to another
- * I/O thread, the main thread lets the I/O thread's event loop run,
- * waiting for the I/O operation to complete. A bdrv_wakeup will wake
- * up the main thread if necessary.
- *
- * Manual calls to bdrv_wakeup are rarely necessary, because
- * bdrv_dec_in_flight already calls it.
- */
-void bdrv_wakeup(BlockDriverState *bs);
-
-#ifdef _WIN32
-int is_windows_drive(const char *filename);
-#endif
-
-/**
- * stream_start:
- * @job_id: The id of the newly-created job, or %NULL to use the
- * device name of @bs.
- * @bs: Block device to operate on.
- * @base: Block device that will become the new base, or %NULL to
- * flatten the whole backing file chain onto @bs.
- * @backing_file_str: The file name that will be written to @bs as the
- * the new backing file if the job completes. Ignored if @base is %NULL.
- * @creation_flags: Flags that control the behavior of the Job lifetime.
- * See @BlockJobCreateFlags
- * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
- * @on_error: The action to take upon error.
- * @filter_node_name: The node name that should be assigned to the filter
- * driver that the stream job inserts into the graph above
- * @bs. NULL means that a node name should be autogenerated.
- * @errp: Error object.
- *
- * Start a streaming operation on @bs. Clusters that are unallocated
- * in @bs, but allocated in any image between @base and @bs (both
- * exclusive) will be written to @bs. At the end of a successful
- * streaming job, the backing file of @bs will be changed to
- * @backing_file_str in the written image and to @base in the live
- * BlockDriverState.
- */
-void stream_start(const char *job_id, BlockDriverState *bs,
- BlockDriverState *base, const char *backing_file_str,
- BlockDriverState *bottom,
- int creation_flags, int64_t speed,
- BlockdevOnError on_error,
- const char *filter_node_name,
- Error **errp);
-
-/**
- * commit_start:
- * @job_id: The id of the newly-created job, or %NULL to use the
- * device name of @bs.
- * @bs: Active block device.
- * @top: Top block device to be committed.
- * @base: Block device that will be written into, and become the new top.
- * @creation_flags: Flags that control the behavior of the Job lifetime.
- * See @BlockJobCreateFlags
- * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
- * @on_error: The action to take upon error.
- * @backing_file_str: String to use as the backing file in @top's overlay
- * @filter_node_name: The node name that should be assigned to the filter
- * driver that the commit job inserts into the graph above @top. NULL means
- * that a node name should be autogenerated.
- * @errp: Error object.
- *
- */
-void commit_start(const char *job_id, BlockDriverState *bs,
- BlockDriverState *base, BlockDriverState *top,
- int creation_flags, int64_t speed,
- BlockdevOnError on_error, const char *backing_file_str,
- const char *filter_node_name, Error **errp);
-/**
- * commit_active_start:
- * @job_id: The id of the newly-created job, or %NULL to use the
- * device name of @bs.
- * @bs: Active block device to be committed.
- * @base: Block device that will be written into, and become the new top.
- * @creation_flags: Flags that control the behavior of the Job lifetime.
- * See @BlockJobCreateFlags
- * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
- * @on_error: The action to take upon error.
- * @filter_node_name: The node name that should be assigned to the filter
- * driver that the commit job inserts into the graph above @bs. NULL means that
- * a node name should be autogenerated.
- * @cb: Completion function for the job.
- * @opaque: Opaque pointer value passed to @cb.
- * @auto_complete: Auto complete the job.
- * @errp: Error object.
- *
- */
-BlockJob *commit_active_start(const char *job_id, BlockDriverState *bs,
- BlockDriverState *base, int creation_flags,
- int64_t speed, BlockdevOnError on_error,
- const char *filter_node_name,
- BlockCompletionFunc *cb, void *opaque,
- bool auto_complete, Error **errp);
-/*
- * mirror_start:
- * @job_id: The id of the newly-created job, or %NULL to use the
- * device name of @bs.
- * @bs: Block device to operate on.
- * @target: Block device to write to.
- * @replaces: Block graph node name to replace once the mirror is done. Can
- * only be used when full mirroring is selected.
- * @creation_flags: Flags that control the behavior of the Job lifetime.
- * See @BlockJobCreateFlags
- * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
- * @granularity: The chosen granularity for the dirty bitmap.
- * @buf_size: The amount of data that can be in flight at one time.
- * @mode: Whether to collapse all images in the chain to the target.
- * @backing_mode: How to establish the target's backing chain after completion.
- * @zero_target: Whether the target should be explicitly zero-initialized
- * @on_source_error: The action to take upon error reading from the source.
- * @on_target_error: The action to take upon error writing to the target.
- * @unmap: Whether to unmap target where source sectors only contain zeroes.
- * @filter_node_name: The node name that should be assigned to the filter
- * driver that the mirror job inserts into the graph above @bs. NULL means that
- * a node name should be autogenerated.
- * @copy_mode: When to trigger writes to the target.
- * @errp: Error object.
- *
- * Start a mirroring operation on @bs. Clusters that are allocated
- * in @bs will be written to @target until the job is cancelled or
- * manually completed. At the end of a successful mirroring job,
- * @bs will be switched to read from @target.
- */
-void mirror_start(const char *job_id, BlockDriverState *bs,
- BlockDriverState *target, const char *replaces,
- int creation_flags, int64_t speed,
- uint32_t granularity, int64_t buf_size,
- MirrorSyncMode mode, BlockMirrorBackingMode backing_mode,
- bool zero_target,
- BlockdevOnError on_source_error,
- BlockdevOnError on_target_error,
- bool unmap, const char *filter_node_name,
- MirrorCopyMode copy_mode, Error **errp);
-
-/*
- * backup_job_create:
- * @job_id: The id of the newly-created job, or %NULL to use the
- * device name of @bs.
- * @bs: Block device to operate on.
- * @target: Block device to write to.
- * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
- * @sync_mode: What parts of the disk image should be copied to the destination.
- * @sync_bitmap: The dirty bitmap if sync_mode is 'bitmap' or 'incremental'
- * @bitmap_mode: The bitmap synchronization policy to use.
- * @perf: Performance options. All actual fields assumed to be present,
- * all ".has_*" fields are ignored.
- * @on_source_error: The action to take upon error reading from the source.
- * @on_target_error: The action to take upon error writing to the target.
- * @creation_flags: Flags that control the behavior of the Job lifetime.
- * See @BlockJobCreateFlags
- * @cb: Completion function for the job.
- * @opaque: Opaque pointer value passed to @cb.
- * @txn: Transaction that this job is part of (may be NULL).
- *
- * Create a backup operation on @bs. Clusters in @bs are written to @target
- * until the job is cancelled or manually completed.
- */
-BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
- BlockDriverState *target, int64_t speed,
- MirrorSyncMode sync_mode,
- BdrvDirtyBitmap *sync_bitmap,
- BitmapSyncMode bitmap_mode,
- bool compress,
- const char *filter_node_name,
- BackupPerf *perf,
- BlockdevOnError on_source_error,
- BlockdevOnError on_target_error,
- int creation_flags,
- BlockCompletionFunc *cb, void *opaque,
- JobTxn *txn, Error **errp);
-
-BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
- const char *child_name,
- const BdrvChildClass *child_class,
- BdrvChildRole child_role,
- uint64_t perm, uint64_t shared_perm,
- void *opaque, Error **errp);
-void bdrv_root_unref_child(BdrvChild *child);
-
-void bdrv_get_cumulative_perm(BlockDriverState *bs, uint64_t *perm,
- uint64_t *shared_perm);
-
-/**
- * Sets a BdrvChild's permissions. Avoid if the parent is a BDS; use
- * bdrv_child_refresh_perms() instead and make the parent's
- * .bdrv_child_perm() implementation return the correct values.
- */
-int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared,
- Error **errp);
-
-/**
- * Calls bs->drv->bdrv_child_perm() and updates the child's permission
- * masks with the result.
- * Drivers should invoke this function whenever an event occurs that
- * makes their .bdrv_child_perm() implementation return different
- * values than before, but which will not result in the block layer
- * automatically refreshing the permissions.
- */
-int bdrv_child_refresh_perms(BlockDriverState *bs, BdrvChild *c, Error **errp);
-
-bool bdrv_recurse_can_replace(BlockDriverState *bs,
- BlockDriverState *to_replace);
-
-/*
- * Default implementation for BlockDriver.bdrv_child_perm() that can
- * be used by block filters and image formats, as long as they use the
- * child_of_bds child class and set an appropriate BdrvChildRole.
- */
-void bdrv_default_perms(BlockDriverState *bs, BdrvChild *c,
- BdrvChildRole role, BlockReopenQueue *reopen_queue,
- uint64_t perm, uint64_t shared,
- uint64_t *nperm, uint64_t *nshared);
-
-const char *bdrv_get_parent_name(const BlockDriverState *bs);
-void blk_dev_change_media_cb(BlockBackend *blk, bool load, Error **errp);
-bool blk_dev_has_removable_media(BlockBackend *blk);
-bool blk_dev_has_tray(BlockBackend *blk);
-void blk_dev_eject_request(BlockBackend *blk, bool force);
-bool blk_dev_is_tray_open(BlockBackend *blk);
-bool blk_dev_is_medium_locked(BlockBackend *blk);
-
-void bdrv_set_dirty(BlockDriverState *bs, int64_t offset, int64_t bytes);
-
-void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out);
-void bdrv_restore_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *backup);
-bool bdrv_dirty_bitmap_merge_internal(BdrvDirtyBitmap *dest,
- const BdrvDirtyBitmap *src,
- HBitmap **backup, bool lock);
-
-void bdrv_inc_in_flight(BlockDriverState *bs);
-void bdrv_dec_in_flight(BlockDriverState *bs);
-
-void blockdev_close_all_bdrv_states(void);
-
-int coroutine_fn bdrv_co_copy_range_from(BdrvChild *src, int64_t src_offset,
- BdrvChild *dst, int64_t dst_offset,
- int64_t bytes,
- BdrvRequestFlags read_flags,
- BdrvRequestFlags write_flags);
-int coroutine_fn bdrv_co_copy_range_to(BdrvChild *src, int64_t src_offset,
- BdrvChild *dst, int64_t dst_offset,
- int64_t bytes,
- BdrvRequestFlags read_flags,
- BdrvRequestFlags write_flags);
-
-int refresh_total_sectors(BlockDriverState *bs, int64_t hint);
-
-void bdrv_set_monitor_owned(BlockDriverState *bs);
-BlockDriverState *bds_tree_init(QDict *bs_opts, Error **errp);
-
-/**
- * Simple implementation of bdrv_co_create_opts for protocol drivers
- * which only support creation via opening a file
- * (usually existing raw storage device)
- */
-int coroutine_fn bdrv_co_create_opts_simple(BlockDriver *drv,
- const char *filename,
- QemuOpts *opts,
- Error **errp);
-extern QemuOptsList bdrv_create_opts_simple;
-
-BdrvDirtyBitmap *block_dirty_bitmap_lookup(const char *node,
- const char *name,
- BlockDriverState **pbs,
- Error **errp);
-BdrvDirtyBitmap *block_dirty_bitmap_merge(const char *node, const char *target,
- BlockDirtyBitmapMergeSourceList *bms,
- HBitmap **backup, Error **errp);
-BdrvDirtyBitmap *block_dirty_bitmap_remove(const char *node, const char *name,
- bool release,
- BlockDriverState **bitmap_bs,
- Error **errp);
-
-BdrvChild *bdrv_cow_child(BlockDriverState *bs);
-BdrvChild *bdrv_filter_child(BlockDriverState *bs);
-BdrvChild *bdrv_filter_or_cow_child(BlockDriverState *bs);
-BdrvChild *bdrv_primary_child(BlockDriverState *bs);
-BlockDriverState *bdrv_skip_implicit_filters(BlockDriverState *bs);
-BlockDriverState *bdrv_skip_filters(BlockDriverState *bs);
-BlockDriverState *bdrv_backing_chain_next(BlockDriverState *bs);
-
-static inline BlockDriverState *child_bs(BdrvChild *child)
-{
- return child ? child->bs : NULL;
-}
-
-static inline BlockDriverState *bdrv_cow_bs(BlockDriverState *bs)
-{
- return child_bs(bdrv_cow_child(bs));
-}
-
-static inline BlockDriverState *bdrv_filter_bs(BlockDriverState *bs)
-{
- return child_bs(bdrv_filter_child(bs));
-}
-
-static inline BlockDriverState *bdrv_filter_or_cow_bs(BlockDriverState *bs)
-{
- return child_bs(bdrv_filter_or_cow_child(bs));
-}
-
-static inline BlockDriverState *bdrv_primary_bs(BlockDriverState *bs)
-{
- return child_bs(bdrv_primary_child(bs));
-}
-
-/**
- * End all quiescent sections started by bdrv_drain_all_begin(). This is
- * needed when deleting a BDS before bdrv_drain_all_end() is called.
- *
- * NOTE: this is an internal helper for bdrv_close() *only*. No one else
- * should call it.
- */
-void bdrv_drain_all_end_quiesce(BlockDriverState *bs);
-
-/**
- * Check whether the given offset is in the cached block-status data
- * region.
- *
- * If it is, and @pnum is not NULL, *pnum is set to
- * `bsc.data_end - offset`, i.e. how many bytes, starting from
- * @offset, are data (according to the cache).
- * Otherwise, *pnum is not touched.
- */
-bool bdrv_bsc_is_data(BlockDriverState *bs, int64_t offset, int64_t *pnum);
-
-/**
- * If [offset, offset + bytes) overlaps with the currently cached
- * block-status region, invalidate the cache.
- *
- * (To be used by I/O paths that cause data regions to be zero or
- * holes.)
- */
-void bdrv_bsc_invalidate_range(BlockDriverState *bs,
- int64_t offset, int64_t bytes);
-
-/**
- * Mark the range [offset, offset + bytes) as a data region.
- */
-void bdrv_bsc_fill(BlockDriverState *bs, int64_t offset, int64_t bytes);
+/* DO NOT ADD ANYTHING IN HERE. USE ONE OF THE HEADERS INCLUDED ABOVE */
#endif /* BLOCK_INT_H */
diff --git a/blockdev.c b/blockdev.c
index 750ff40d41..0698398a94 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -63,6 +63,7 @@
#include "qemu/main-loop.h"
#include "qemu/throttle-options.h"
+/* Protected by BQL lock */
QTAILQ_HEAD(, BlockDriverState) monitor_bdrv_states =
QTAILQ_HEAD_INITIALIZER(monitor_bdrv_states);
@@ -1165,6 +1166,8 @@ typedef struct BlkActionState BlkActionState;
*
* Only prepare() may fail. In a single transaction, only one of commit() or
* abort() will be called. clean() will always be called if it is present.
+ *
+ * Always run under BQL.
*/
typedef struct BlkActionOps {
size_t instance_size;
@@ -2274,6 +2277,8 @@ static TransactionProperties *get_transaction_properties(
/*
* 'Atomic' group operations. The operations are performed as a set, and if
* any fail then we roll back all operations in the group.
+ *
+ * Always run under BQL.
*/
void qmp_transaction(TransactionActionList *dev_list,
bool has_props,
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 08/31] assertions for block_int global state API
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (6 preceding siblings ...)
2021-11-24 6:43 ` [PATCH v5 07/31] include/block/block_int: split header into I/O and global state API Emanuele Giuseppe Esposito
@ 2021-11-24 6:43 ` Emanuele Giuseppe Esposito
2021-11-24 6:43 ` [PATCH v5 09/31] block: introduce assert_bdrv_graph_writable Emanuele Giuseppe Esposito
` (23 subsequent siblings)
31 siblings, 0 replies; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:43 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
block.c | 15 +++++++++++++++
block/backup.c | 1 +
block/block-backend.c | 3 +++
block/commit.c | 2 ++
block/dirty-bitmap.c | 1 +
block/io.c | 1 +
block/mirror.c | 4 ++++
block/monitor/bitmap-qmp-cmds.c | 6 ++++++
block/stream.c | 2 ++
blockdev.c | 7 +++++++
10 files changed, 42 insertions(+)
diff --git a/block.c b/block.c
index 49bee69e27..198ec636ff 100644
--- a/block.c
+++ b/block.c
@@ -662,6 +662,8 @@ int coroutine_fn bdrv_co_create_opts_simple(BlockDriver *drv,
Error *local_err = NULL;
int ret;
+ assert(qemu_in_main_thread());
+
size = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0);
buf = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC);
prealloc = qapi_enum_parse(&PreallocMode_lookup, buf,
@@ -2492,6 +2494,8 @@ void bdrv_get_cumulative_perm(BlockDriverState *bs, uint64_t *perm,
uint64_t cumulative_perms = 0;
uint64_t cumulative_shared_perms = BLK_PERM_ALL;
+ assert(qemu_in_main_thread());
+
QLIST_FOREACH(c, &bs->parents, next_parent) {
cumulative_perms |= c->perm;
cumulative_shared_perms &= c->shared_perm;
@@ -2552,6 +2556,8 @@ int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared,
Transaction *tran = tran_new();
int ret;
+ assert(qemu_in_main_thread());
+
bdrv_child_set_perm(c, perm, shared, tran);
ret = bdrv_refresh_perms(c->bs, &local_err);
@@ -2582,6 +2588,8 @@ int bdrv_child_refresh_perms(BlockDriverState *bs, BdrvChild *c, Error **errp)
uint64_t parent_perms, parent_shared;
uint64_t perms, shared;
+ assert(qemu_in_main_thread());
+
bdrv_get_cumulative_perm(bs, &parent_perms, &parent_shared);
bdrv_child_perm(bs, c->bs, c, c->role, NULL,
parent_perms, parent_shared, &perms, &shared);
@@ -2724,6 +2732,7 @@ void bdrv_default_perms(BlockDriverState *bs, BdrvChild *c,
uint64_t perm, uint64_t shared,
uint64_t *nperm, uint64_t *nshared)
{
+ assert(qemu_in_main_thread());
if (role & BDRV_CHILD_FILTERED) {
assert(!(role & (BDRV_CHILD_DATA | BDRV_CHILD_METADATA |
BDRV_CHILD_COW)));
@@ -3084,6 +3093,8 @@ BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
BdrvChild *child = NULL;
Transaction *tran = tran_new();
+ assert(qemu_in_main_thread());
+
ret = bdrv_attach_child_common(child_bs, child_name, child_class,
child_role, perm, shared_perm, opaque,
&child, tran, errp);
@@ -7436,6 +7447,8 @@ bool bdrv_recurse_can_replace(BlockDriverState *bs,
{
BlockDriverState *filtered;
+ assert(qemu_in_main_thread());
+
if (!bs || !bs->drv) {
return false;
}
@@ -7607,6 +7620,7 @@ static bool append_strong_runtime_options(QDict *d, BlockDriverState *bs)
* would result in exactly bs->backing. */
static bool bdrv_backing_overridden(BlockDriverState *bs)
{
+ assert(qemu_in_main_thread());
if (bs->backing) {
return strcmp(bs->auto_backing_file,
bs->backing->bs->filename);
@@ -7995,6 +8009,7 @@ static BlockDriverState *bdrv_do_skip_filters(BlockDriverState *bs,
*/
BlockDriverState *bdrv_skip_implicit_filters(BlockDriverState *bs)
{
+ assert(qemu_in_main_thread());
return bdrv_do_skip_filters(bs, true);
}
diff --git a/block/backup.c b/block/backup.c
index 21d5983779..c53041772c 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -372,6 +372,7 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
assert(bs);
assert(target);
+ assert(qemu_in_main_thread());
/* QMP interface protects us from these cases */
assert(sync_mode != MIRROR_SYNC_MODE_INCREMENTAL);
diff --git a/block/block-backend.c b/block/block-backend.c
index 11131ca68c..56670a774f 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -1095,6 +1095,7 @@ static void blk_root_change_media(BdrvChild *child, bool load)
*/
bool blk_dev_has_removable_media(BlockBackend *blk)
{
+ assert(qemu_in_main_thread());
return !blk->dev || (blk->dev_ops && blk->dev_ops->change_media_cb);
}
@@ -1112,6 +1113,7 @@ bool blk_dev_has_tray(BlockBackend *blk)
*/
void blk_dev_eject_request(BlockBackend *blk, bool force)
{
+ assert(qemu_in_main_thread());
if (blk->dev_ops && blk->dev_ops->eject_request_cb) {
blk->dev_ops->eject_request_cb(blk->dev_opaque, force);
}
@@ -1134,6 +1136,7 @@ bool blk_dev_is_tray_open(BlockBackend *blk)
*/
bool blk_dev_is_medium_locked(BlockBackend *blk)
{
+ assert(qemu_in_main_thread());
if (blk->dev_ops && blk->dev_ops->is_medium_locked) {
return blk->dev_ops->is_medium_locked(blk->dev_opaque);
}
diff --git a/block/commit.c b/block/commit.c
index 45a414a19b..f639eb49c5 100644
--- a/block/commit.c
+++ b/block/commit.c
@@ -253,6 +253,8 @@ void commit_start(const char *job_id, BlockDriverState *bs,
uint64_t base_perms, iter_shared_perms;
int ret;
+ assert(qemu_in_main_thread());
+
assert(top != bs);
if (bdrv_skip_filters(top) == bdrv_skip_filters(base)) {
error_setg(errp, "Invalid files for merge: top and base are the same");
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index 0ef46163e3..49462ca121 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -673,6 +673,7 @@ void bdrv_restore_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *backup)
{
HBitmap *tmp = bitmap->bitmap;
assert(!bdrv_dirty_bitmap_readonly(bitmap));
+ assert(qemu_in_main_thread());
bitmap->bitmap = backup;
hbitmap_free(tmp);
}
diff --git a/block/io.c b/block/io.c
index 51497d1b27..cb095deeec 100644
--- a/block/io.c
+++ b/block/io.c
@@ -687,6 +687,7 @@ void bdrv_drain_all_end_quiesce(BlockDriverState *bs)
{
int drained_end_counter = 0;
+ assert(qemu_in_main_thread());
g_assert(bs->quiesce_counter > 0);
g_assert(!bs->refcnt);
diff --git a/block/mirror.c b/block/mirror.c
index efec2c7674..00089e519b 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -1880,6 +1880,8 @@ void mirror_start(const char *job_id, BlockDriverState *bs,
bool is_none_mode;
BlockDriverState *base;
+ assert(qemu_in_main_thread());
+
if ((mode == MIRROR_SYNC_MODE_INCREMENTAL) ||
(mode == MIRROR_SYNC_MODE_BITMAP)) {
error_setg(errp, "Sync mode '%s' not supported",
@@ -1905,6 +1907,8 @@ BlockJob *commit_active_start(const char *job_id, BlockDriverState *bs,
bool base_read_only;
BlockJob *job;
+ assert(qemu_in_main_thread());
+
base_read_only = bdrv_is_read_only(base);
if (base_read_only) {
diff --git a/block/monitor/bitmap-qmp-cmds.c b/block/monitor/bitmap-qmp-cmds.c
index 9f11deec64..8b8d30287a 100644
--- a/block/monitor/bitmap-qmp-cmds.c
+++ b/block/monitor/bitmap-qmp-cmds.c
@@ -56,6 +56,8 @@ BdrvDirtyBitmap *block_dirty_bitmap_lookup(const char *node,
BlockDriverState *bs;
BdrvDirtyBitmap *bitmap;
+ assert(qemu_in_main_thread());
+
if (!node) {
error_setg(errp, "Node cannot be NULL");
return NULL;
@@ -155,6 +157,8 @@ BdrvDirtyBitmap *block_dirty_bitmap_remove(const char *node, const char *name,
BdrvDirtyBitmap *bitmap;
AioContext *aio_context;
+ assert(qemu_in_main_thread());
+
bitmap = block_dirty_bitmap_lookup(node, name, &bs, errp);
if (!bitmap || !bs) {
return NULL;
@@ -261,6 +265,8 @@ BdrvDirtyBitmap *block_dirty_bitmap_merge(const char *node, const char *target,
BlockDirtyBitmapMergeSourceList *lst;
Error *local_err = NULL;
+ assert(qemu_in_main_thread());
+
dst = block_dirty_bitmap_lookup(node, target, &bs, errp);
if (!dst) {
return NULL;
diff --git a/block/stream.c b/block/stream.c
index e45113aed6..3dff31beb8 100644
--- a/block/stream.c
+++ b/block/stream.c
@@ -219,6 +219,8 @@ void stream_start(const char *job_id, BlockDriverState *bs,
QDict *opts;
int ret;
+ assert(qemu_in_main_thread());
+
assert(!(base && bottom));
assert(!(backing_file_str && bottom));
diff --git a/blockdev.c b/blockdev.c
index 0698398a94..7706919410 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -69,6 +69,7 @@ QTAILQ_HEAD(, BlockDriverState) monitor_bdrv_states =
void bdrv_set_monitor_owned(BlockDriverState *bs)
{
+ assert(qemu_in_main_thread());
QTAILQ_INSERT_TAIL(&monitor_bdrv_states, bs, monitor_list);
}
@@ -619,6 +620,7 @@ BlockDriverState *bds_tree_init(QDict *bs_opts, Error **errp)
{
int bdrv_flags = 0;
+ assert(qemu_in_main_thread());
/* bdrv_open() defaults to the values in bdrv_flags (for compatibility
* with other callers) rather than what we want as the real defaults.
* Apply the defaults here instead. */
@@ -637,6 +639,7 @@ void blockdev_close_all_bdrv_states(void)
{
BlockDriverState *bs, *next_bs;
+ assert(qemu_in_main_thread());
QTAILQ_FOREACH_SAFE(bs, &monitor_bdrv_states, monitor_list, next_bs) {
AioContext *ctx = bdrv_get_aio_context(bs);
@@ -2290,6 +2293,8 @@ void qmp_transaction(TransactionActionList *dev_list,
BlkActionState *state, *next;
Error *local_err = NULL;
+ assert(qemu_in_main_thread());
+
QTAILQ_HEAD(, BlkActionState) snap_bdrv_states;
QTAILQ_INIT(&snap_bdrv_states);
@@ -3583,6 +3588,8 @@ void qmp_blockdev_del(const char *node_name, Error **errp)
AioContext *aio_context;
BlockDriverState *bs;
+ assert(qemu_in_main_thread());
+
bs = bdrv_find_node(node_name);
if (!bs) {
error_setg(errp, "Failed to find node with node-name='%s'", node_name);
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 09/31] block: introduce assert_bdrv_graph_writable
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (7 preceding siblings ...)
2021-11-24 6:43 ` [PATCH v5 08/31] assertions for block_int " Emanuele Giuseppe Esposito
@ 2021-11-24 6:43 ` Emanuele Giuseppe Esposito
2021-12-10 17:43 ` Hanna Reitz
2021-11-24 6:43 ` [PATCH v5 10/31] block.c: modify .attach and .detach callbacks of child_of_bds Emanuele Giuseppe Esposito
` (22 subsequent siblings)
31 siblings, 1 reply; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:43 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
We want to be sure that the functions that write the child and
parent list of a bs are under BQL and drain.
BQL prevents from concurrent writings from the GS API, while
drains protect from I/O.
TODO: drains are missing in some functions using this assert.
Therefore a proper assertion will fail. Because adding drains
requires additional discussions, they will be added in future
series.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
include/block/block_int-global-state.h | 10 +++++++++-
block.c | 4 ++++
block/io.c | 11 +++++++++++
3 files changed, 24 insertions(+), 1 deletion(-)
diff --git a/include/block/block_int-global-state.h b/include/block/block_int-global-state.h
index a1b7d0579d..fa96e8b449 100644
--- a/include/block/block_int-global-state.h
+++ b/include/block/block_int-global-state.h
@@ -312,4 +312,12 @@ void bdrv_remove_aio_context_notifier(BlockDriverState *bs,
*/
void bdrv_drain_all_end_quiesce(BlockDriverState *bs);
-#endif /* BLOCK_INT_GLOBAL_STATE*/
+/**
+ * Make sure that the function is running under both drain and BQL.
+ * The latter protects from concurrent writings
+ * from the GS API, while the former prevents concurrent reads
+ * from I/O.
+ */
+void assert_bdrv_graph_writable(BlockDriverState *bs);
+
+#endif /* BLOCK_INT_GLOBAL_STATE */
diff --git a/block.c b/block.c
index 198ec636ff..522a273140 100644
--- a/block.c
+++ b/block.c
@@ -1416,6 +1416,7 @@ static void bdrv_child_cb_attach(BdrvChild *child)
{
BlockDriverState *bs = child->opaque;
+ assert_bdrv_graph_writable(bs);
QLIST_INSERT_HEAD(&bs->children, child, next);
if (child->role & BDRV_CHILD_COW) {
@@ -1435,6 +1436,7 @@ static void bdrv_child_cb_detach(BdrvChild *child)
bdrv_unapply_subtree_drain(child, bs);
+ assert_bdrv_graph_writable(bs);
QLIST_REMOVE(child, next);
}
@@ -2818,6 +2820,7 @@ static void bdrv_replace_child_noperm(BdrvChild **childp,
if (child->klass->detach) {
child->klass->detach(child);
}
+ assert_bdrv_graph_writable(old_bs);
QLIST_REMOVE(child, next_parent);
}
@@ -2827,6 +2830,7 @@ static void bdrv_replace_child_noperm(BdrvChild **childp,
}
if (new_bs) {
+ assert_bdrv_graph_writable(new_bs);
QLIST_INSERT_HEAD(&new_bs->parents, child, next_parent);
/*
diff --git a/block/io.c b/block/io.c
index cb095deeec..3be08cad29 100644
--- a/block/io.c
+++ b/block/io.c
@@ -734,6 +734,17 @@ void bdrv_drain_all(void)
bdrv_drain_all_end();
}
+void assert_bdrv_graph_writable(BlockDriverState *bs)
+{
+ /*
+ * TODO: this function is incomplete. Because the users of this
+ * assert lack the necessary drains, check only for BQL.
+ * Once the necessary drains are added,
+ * assert also for qatomic_read(&bs->quiesce_counter) > 0
+ */
+ assert(qemu_in_main_thread());
+}
+
/**
* Remove an active request from the tracked requests list
*
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 10/31] block.c: modify .attach and .detach callbacks of child_of_bds
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (8 preceding siblings ...)
2021-11-24 6:43 ` [PATCH v5 09/31] block: introduce assert_bdrv_graph_writable Emanuele Giuseppe Esposito
@ 2021-11-24 6:43 ` Emanuele Giuseppe Esposito
2021-12-16 14:57 ` Hanna Reitz
2021-11-24 6:43 ` [PATCH v5 11/31] include/block/blockjob_int.h: split header into I/O and GS API Emanuele Giuseppe Esposito
` (21 subsequent siblings)
31 siblings, 1 reply; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:43 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
According to the assertions put in the previous patch, we should
first drain and then modify the ->children list. In this way
we prevent other iothreads to read the list while it is being
updated.
In this case, moving the drain won't cause any harm, because
child is a parameter of the drain function so it will still be
included in the operation, despite not being in the list.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
block.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/block.c b/block.c
index 522a273140..5516c84ec4 100644
--- a/block.c
+++ b/block.c
@@ -1416,6 +1416,7 @@ static void bdrv_child_cb_attach(BdrvChild *child)
{
BlockDriverState *bs = child->opaque;
+ bdrv_apply_subtree_drain(child, bs);
assert_bdrv_graph_writable(bs);
QLIST_INSERT_HEAD(&bs->children, child, next);
@@ -1423,7 +1424,6 @@ static void bdrv_child_cb_attach(BdrvChild *child)
bdrv_backing_attach(child);
}
- bdrv_apply_subtree_drain(child, bs);
}
static void bdrv_child_cb_detach(BdrvChild *child)
@@ -1434,10 +1434,9 @@ static void bdrv_child_cb_detach(BdrvChild *child)
bdrv_backing_detach(child);
}
- bdrv_unapply_subtree_drain(child, bs);
-
assert_bdrv_graph_writable(bs);
QLIST_REMOVE(child, next);
+ bdrv_unapply_subtree_drain(child, bs);
}
static int bdrv_child_cb_update_filename(BdrvChild *c, BlockDriverState *base,
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 11/31] include/block/blockjob_int.h: split header into I/O and GS API
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (9 preceding siblings ...)
2021-11-24 6:43 ` [PATCH v5 10/31] block.c: modify .attach and .detach callbacks of child_of_bds Emanuele Giuseppe Esposito
@ 2021-11-24 6:43 ` Emanuele Giuseppe Esposito
2021-11-24 6:43 ` [PATCH v5 12/31] assertions for blockjob_int.h Emanuele Giuseppe Esposito
` (20 subsequent siblings)
31 siblings, 0 replies; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:43 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
Since the I/O functions are not many, keep a single file.
Also split the function pointers in BlockJobDriver.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
include/block/blockjob_int.h | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/include/block/blockjob_int.h b/include/block/blockjob_int.h
index 6633d83da2..718d7b92d2 100644
--- a/include/block/blockjob_int.h
+++ b/include/block/blockjob_int.h
@@ -38,6 +38,13 @@ struct BlockJobDriver {
/** Generic JobDriver callbacks and settings */
JobDriver job_driver;
+ /*
+ * I/O API functions. These functions are thread-safe.
+ *
+ * See include/block/block-io.h for more information about
+ * the I/O API.
+ */
+
/*
* Returns whether the job has pending requests for the child or will
* submit new requests before the next pause point. This callback is polled
@@ -46,6 +53,13 @@ struct BlockJobDriver {
*/
bool (*drained_poll)(BlockJob *job);
+ /*
+ * Global state (GS) API. These functions run under the BQL lock.
+ *
+ * See include/block/block-global-state.h for more information about
+ * the GS API.
+ */
+
/*
* If the callback is not NULL, it will be invoked before the job is
* resumed in a new AioContext. This is the place to move any resources
@@ -56,6 +70,13 @@ struct BlockJobDriver {
void (*set_speed)(BlockJob *job, int64_t speed);
};
+/*
+ * Global state (GS) API. These functions run under the BQL lock.
+ *
+ * See include/block/block-global-state.h for more information about
+ * the GS API.
+ */
+
/**
* block_job_create:
* @job_id: The id of the newly-created job, or %NULL to have one
@@ -98,6 +119,13 @@ void block_job_free(Job *job);
*/
void block_job_user_resume(Job *job);
+/*
+ * I/O API functions. These functions are thread-safe.
+ *
+ * See include/block/block-io.h for more information about
+ * the I/O API.
+ */
+
/**
* block_job_ratelimit_get_delay:
*
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 12/31] assertions for blockjob_int.h
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (10 preceding siblings ...)
2021-11-24 6:43 ` [PATCH v5 11/31] include/block/blockjob_int.h: split header into I/O and GS API Emanuele Giuseppe Esposito
@ 2021-11-24 6:43 ` Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 13/31] block.c: add assertions to static functions Emanuele Giuseppe Esposito
` (19 subsequent siblings)
31 siblings, 0 replies; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:43 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
blockjob.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/blockjob.c b/blockjob.c
index 4bad1408cb..10c807413e 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -84,6 +84,7 @@ BlockJob *block_job_get(const char *id)
void block_job_free(Job *job)
{
BlockJob *bjob = container_of(job, BlockJob, job);
+ assert(qemu_in_main_thread());
block_job_remove_all_bdrv(bjob);
blk_unref(bjob->blk);
@@ -436,6 +437,8 @@ void *block_job_create(const char *job_id, const BlockJobDriver *driver,
BlockBackend *blk;
BlockJob *job;
+ assert(qemu_in_main_thread());
+
if (job_id == NULL && !(flags & JOB_INTERNAL)) {
job_id = bdrv_get_device_name(bs);
}
@@ -505,6 +508,7 @@ void block_job_iostatus_reset(BlockJob *job)
void block_job_user_resume(Job *job)
{
BlockJob *bjob = container_of(job, BlockJob, job);
+ assert(qemu_in_main_thread());
block_job_iostatus_reset(bjob);
}
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 13/31] block.c: add assertions to static functions
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (11 preceding siblings ...)
2021-11-24 6:43 ` [PATCH v5 12/31] assertions for blockjob_int.h Emanuele Giuseppe Esposito
@ 2021-11-24 6:44 ` Emanuele Giuseppe Esposito
2021-12-16 16:08 ` Hanna Reitz
2021-11-24 6:44 ` [PATCH v5 14/31] include/block/blockjob.h: global state API Emanuele Giuseppe Esposito
` (18 subsequent siblings)
31 siblings, 1 reply; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:44 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
Following the assertion derived from the API split,
propagate the assertion also in the static functions.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
block.c | 45 ++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 44 insertions(+), 1 deletion(-)
diff --git a/block.c b/block.c
index 5516c84ec4..b77ab0a104 100644
--- a/block.c
+++ b/block.c
@@ -434,6 +434,7 @@ BlockDriverState *bdrv_new(void)
static BlockDriver *bdrv_do_find_format(const char *format_name)
{
BlockDriver *drv1;
+ assert(qemu_in_main_thread());
QLIST_FOREACH(drv1, &bdrv_drivers, list) {
if (!strcmp(drv1->format_name, format_name)) {
@@ -593,6 +594,8 @@ static int64_t create_file_fallback_truncate(BlockBackend *blk,
int64_t size;
int ret;
+ assert(qemu_in_main_thread());
+
ret = blk_truncate(blk, minimum_size, false, PREALLOC_MODE_OFF, 0,
&local_err);
if (ret < 0 && ret != -ENOTSUP) {
@@ -631,6 +634,8 @@ static int create_file_fallback_zero_first_sector(BlockBackend *blk,
int64_t bytes_to_clear;
int ret;
+ assert(qemu_in_main_thread());
+
bytes_to_clear = MIN(current_size, BDRV_SECTOR_SIZE);
if (bytes_to_clear) {
ret = blk_pwrite_zeroes(blk, 0, bytes_to_clear, BDRV_REQ_MAY_UNMAP);
@@ -891,6 +896,7 @@ static BlockDriver *find_hdev_driver(const char *filename)
{
int score_max = 0, score;
BlockDriver *drv = NULL, *d;
+ assert(qemu_in_main_thread());
QLIST_FOREACH(d, &bdrv_drivers, list) {
if (d->bdrv_probe_device) {
@@ -908,6 +914,7 @@ static BlockDriver *find_hdev_driver(const char *filename)
static BlockDriver *bdrv_do_find_protocol(const char *protocol)
{
BlockDriver *drv1;
+ assert(qemu_in_main_thread());
QLIST_FOREACH(drv1, &bdrv_drivers, list) {
if (drv1->protocol_name && !strcmp(drv1->protocol_name, protocol)) {
@@ -1016,6 +1023,8 @@ static int find_image_format(BlockBackend *file, const char *filename,
uint8_t buf[BLOCK_PROBE_BUF_SIZE];
int ret = 0;
+ assert(qemu_in_main_thread());
+
/* Return the raw BlockDriver * to scsi-generic devices or empty drives */
if (blk_is_sg(file) || !blk_is_inserted(file) || blk_getlength(file) == 0) {
*pdrv = &bdrv_raw;
@@ -1097,6 +1106,7 @@ static BlockdevDetectZeroesOptions bdrv_parse_detect_zeroes(QemuOpts *opts,
BlockdevDetectZeroesOptions detect_zeroes =
qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup, value,
BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF, &local_err);
+ assert(qemu_in_main_thread());
g_free(value);
if (local_err) {
error_propagate(errp, local_err);
@@ -1214,6 +1224,7 @@ static void bdrv_child_cb_drained_end(BdrvChild *child,
static int bdrv_child_cb_inactivate(BdrvChild *child)
{
BlockDriverState *bs = child->opaque;
+ assert(qemu_in_main_thread());
assert(bs->open_flags & BDRV_O_INACTIVE);
return 0;
}
@@ -1241,6 +1252,7 @@ static void bdrv_temp_snapshot_options(int *child_flags, QDict *child_options,
int parent_flags, QDict *parent_options)
{
*child_flags = (parent_flags & ~BDRV_O_SNAPSHOT) | BDRV_O_TEMPORARY;
+ assert(qemu_in_main_thread());
/* For temporary files, unconditional cache=unsafe is fine */
qdict_set_default_str(child_options, BDRV_OPT_CACHE_DIRECT, "off");
@@ -1260,6 +1272,7 @@ static void bdrv_backing_attach(BdrvChild *c)
BlockDriverState *parent = c->opaque;
BlockDriverState *backing_hd = c->bs;
+ assert(qemu_in_main_thread());
assert(!parent->backing_blocker);
error_setg(&parent->backing_blocker,
"node is used as backing hd of '%s'",
@@ -1298,6 +1311,7 @@ static void bdrv_backing_detach(BdrvChild *c)
{
BlockDriverState *parent = c->opaque;
+ assert(qemu_in_main_thread());
assert(parent->backing_blocker);
bdrv_op_unblock_all(c->bs, parent->backing_blocker);
error_free(parent->backing_blocker);
@@ -1310,6 +1324,7 @@ static int bdrv_backing_update_filename(BdrvChild *c, BlockDriverState *base,
BlockDriverState *parent = c->opaque;
bool read_only = bdrv_is_read_only(parent);
int ret;
+ assert(qemu_in_main_thread());
if (read_only) {
ret = bdrv_reopen_set_read_only(parent, false, errp);
@@ -1341,6 +1356,7 @@ static void bdrv_inherited_options(BdrvChildRole role, bool parent_is_format,
int parent_flags, QDict *parent_options)
{
int flags = parent_flags;
+ assert(qemu_in_main_thread());
/*
* First, decide whether to set, clear, or leave BDRV_O_PROTOCOL.
@@ -1479,6 +1495,7 @@ AioContext *bdrv_child_get_parent_aio_context(BdrvChild *c)
static int bdrv_open_flags(BlockDriverState *bs, int flags)
{
int open_flags = flags;
+ assert(qemu_in_main_thread());
/*
* Clear flags that are internal to the block layer before opening the
@@ -1491,6 +1508,8 @@ static int bdrv_open_flags(BlockDriverState *bs, int flags)
static void update_flags_from_options(int *flags, QemuOpts *opts)
{
+ assert(qemu_in_main_thread());
+
*flags &= ~(BDRV_O_CACHE_MASK | BDRV_O_RDWR | BDRV_O_AUTO_RDONLY);
if (qemu_opt_get_bool_del(opts, BDRV_OPT_CACHE_NO_FLUSH, false)) {
@@ -1512,6 +1531,7 @@ static void update_flags_from_options(int *flags, QemuOpts *opts)
static void update_options_from_flags(QDict *options, int flags)
{
+ assert(qemu_in_main_thread());
if (!qdict_haskey(options, BDRV_OPT_CACHE_DIRECT)) {
qdict_put_bool(options, BDRV_OPT_CACHE_DIRECT, flags & BDRV_O_NOCACHE);
}
@@ -1533,6 +1553,7 @@ static void bdrv_assign_node_name(BlockDriverState *bs,
Error **errp)
{
char *gen_node_name = NULL;
+ assert(qemu_in_main_thread());
if (!node_name) {
node_name = gen_node_name = id_generate(ID_BLOCK);
@@ -1779,6 +1800,7 @@ static int bdrv_open_common(BlockDriverState *bs, BlockBackend *file,
assert(bs->file == NULL);
assert(options != NULL && bs->options != options);
+ assert(qemu_in_main_thread());
opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort);
if (!qemu_opts_absorb_qdict(opts, options, errp)) {
@@ -1904,6 +1926,7 @@ static QDict *parse_json_filename(const char *filename, Error **errp)
QObject *options_obj;
QDict *options;
int ret;
+ assert(qemu_in_main_thread());
ret = strstart(filename, "json:", &filename);
assert(ret);
@@ -1931,6 +1954,7 @@ static void parse_json_protocol(QDict *options, const char **pfilename,
{
QDict *json_options;
Error *local_err = NULL;
+ assert(qemu_in_main_thread());
/* Parse json: pseudo-protocol */
if (!*pfilename || !g_str_has_prefix(*pfilename, "json:")) {
@@ -2184,6 +2208,8 @@ static GSList *bdrv_topological_dfs(GSList *list, GHashTable *found,
BdrvChild *child;
g_autoptr(GHashTable) local_found = NULL;
+ assert(qemu_in_main_thread());
+
if (!found) {
assert(!list);
found = local_found = g_hash_table_new(NULL, NULL);
@@ -2295,6 +2321,7 @@ typedef struct BdrvReplaceChildState {
static void bdrv_replace_child_commit(void *opaque)
{
BdrvReplaceChildState *s = opaque;
+ assert(qemu_in_main_thread());
if (s->free_empty_child && !s->child->bs) {
bdrv_child_free(s->child);
@@ -2307,6 +2334,7 @@ static void bdrv_replace_child_abort(void *opaque)
BdrvReplaceChildState *s = opaque;
BlockDriverState *new_bs = s->child->bs;
+ assert(qemu_in_main_thread());
/*
* old_bs reference is transparently moved from @s to s->child.
*
@@ -2872,6 +2900,7 @@ static void bdrv_replace_child_noperm(BdrvChild **childp,
static void bdrv_child_free(BdrvChild *child)
{
assert(!child->bs);
+ assert(qemu_in_main_thread());
assert(!child->next.le_prev); /* not in children list */
g_free(child->name);
@@ -2952,6 +2981,7 @@ static int bdrv_attach_child_common(BlockDriverState *child_bs,
assert(child);
assert(*child == NULL);
assert(child_class->get_parent_desc);
+ assert(qemu_in_main_thread());
new_child = g_new(BdrvChild, 1);
*new_child = (BdrvChild) {
@@ -3032,6 +3062,7 @@ static int bdrv_attach_child_noperm(BlockDriverState *parent_bs,
uint64_t perm, shared_perm;
assert(parent_bs->drv);
+ assert(qemu_in_main_thread());
if (bdrv_recurse_has_child(child_bs, parent_bs)) {
error_setg(errp, "Making '%s' a %s child of '%s' would create a cycle",
@@ -3057,6 +3088,7 @@ static void bdrv_detach_child(BdrvChild **childp)
{
BlockDriverState *old_bs = (*childp)->bs;
+ assert(qemu_in_main_thread());
bdrv_replace_child_noperm(childp, NULL, true);
if (old_bs) {
@@ -3305,6 +3337,8 @@ static int bdrv_set_file_or_backing_noperm(BlockDriverState *parent_bs,
BdrvChild *child = is_backing ? parent_bs->backing : parent_bs->file;
BdrvChildRole role;
+ assert(qemu_in_main_thread());
+
if (!parent_bs->drv) {
/*
* Node without drv is an object without a class :/. TODO: finally fix
@@ -3384,6 +3418,7 @@ static int bdrv_set_backing_noperm(BlockDriverState *bs,
BlockDriverState *backing_hd,
Transaction *tran, Error **errp)
{
+ assert(qemu_in_main_thread());
return bdrv_set_file_or_backing_noperm(bs, backing_hd, true, tran, errp);
}
@@ -3659,6 +3694,8 @@ static BlockDriverState *bdrv_append_temp_snapshot(BlockDriverState *bs,
BlockDriverState *bs_snapshot = NULL;
int ret;
+ assert(qemu_in_main_thread());
+
/* if snapshot, we create a temporary backing file and open it
instead of opening 'filename' directly */
@@ -4485,6 +4522,8 @@ static int bdrv_reopen_parse_file_or_backing(BDRVReopenState *reopen_state,
QObject *value;
const char *str;
+ assert(qemu_in_main_thread());
+
value = qdict_get(reopen_state->options, child_name);
if (value == NULL) {
return 0;
@@ -5024,7 +5063,7 @@ static void bdrv_remove_filter_or_cow_child_abort(void *opaque)
static void bdrv_remove_filter_or_cow_child_commit(void *opaque)
{
BdrvRemoveFilterOrCowChild *s = opaque;
-
+ assert(qemu_in_main_thread());
bdrv_child_free(s->child);
}
@@ -5157,6 +5196,7 @@ static int bdrv_replace_node_common(BlockDriverState *from,
BlockDriverState *to_cow_parent = NULL;
int ret;
+ assert(qemu_in_main_thread());
assert(to != NULL);
if (detach_subchain) {
@@ -5315,6 +5355,7 @@ static void bdrv_delete(BlockDriverState *bs)
{
assert(bdrv_op_blocker_is_empty(bs));
assert(!bs->refcnt);
+ assert(qemu_in_main_thread());
/* remove from list, if necessary */
if (bs->node_name[0] != '\0') {
@@ -6318,6 +6359,7 @@ void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event)
static BlockDriverState *bdrv_find_debug_node(BlockDriverState *bs)
{
+ assert(qemu_in_main_thread());
while (bs && bs->drv && !bs->drv->bdrv_debug_breakpoint) {
bs = bdrv_primary_bs(bs);
}
@@ -7128,6 +7170,7 @@ void bdrv_coroutine_enter(BlockDriverState *bs, Coroutine *co)
static void bdrv_do_remove_aio_context_notifier(BdrvAioNotifier *ban)
{
+ assert(qemu_in_main_thread());
QLIST_REMOVE(ban, list);
g_free(ban);
}
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 14/31] include/block/blockjob.h: global state API
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (12 preceding siblings ...)
2021-11-24 6:44 ` [PATCH v5 13/31] block.c: add assertions to static functions Emanuele Giuseppe Esposito
@ 2021-11-24 6:44 ` Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 15/31] assertions for blockjob.h " Emanuele Giuseppe Esposito
` (17 subsequent siblings)
31 siblings, 0 replies; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:44 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
blockjob functions run always under the BQL lock.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
include/block/blockjob.h | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/include/block/blockjob.h b/include/block/blockjob.h
index d200f33c10..fa0c3f7a47 100644
--- a/include/block/blockjob.h
+++ b/include/block/blockjob.h
@@ -77,6 +77,13 @@ typedef struct BlockJob {
GSList *nodes;
} BlockJob;
+/*
+ * Global state (GS) API. These functions run under the BQL lock.
+ *
+ * See include/block/block-global-state.h for more information about
+ * the GS API.
+ */
+
/**
* block_job_next:
* @job: A block job, or %NULL.
@@ -158,6 +165,8 @@ BlockJobInfo *block_job_query(BlockJob *job, Error **errp);
*/
void block_job_iostatus_reset(BlockJob *job);
+/* Common functions that are neither I/O nor Global State */
+
/**
* block_job_is_internal:
* @job: The job to determine if it is user-visible or not.
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 15/31] assertions for blockjob.h global state API
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (13 preceding siblings ...)
2021-11-24 6:44 ` [PATCH v5 14/31] include/block/blockjob.h: global state API Emanuele Giuseppe Esposito
@ 2021-11-24 6:44 ` Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 16/31] include/sysemu/blockdev.h: " Emanuele Giuseppe Esposito
` (16 subsequent siblings)
31 siblings, 0 replies; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:44 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
blockjob.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/blockjob.c b/blockjob.c
index 10c807413e..74476af473 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -62,6 +62,7 @@ static bool is_block_job(Job *job)
BlockJob *block_job_next(BlockJob *bjob)
{
Job *job = bjob ? &bjob->job : NULL;
+ assert(qemu_in_main_thread());
do {
job = job_next(job);
@@ -73,6 +74,7 @@ BlockJob *block_job_next(BlockJob *bjob)
BlockJob *block_job_get(const char *id)
{
Job *job = job_get(id);
+ assert(qemu_in_main_thread());
if (job && is_block_job(job)) {
return container_of(job, BlockJob, job);
@@ -185,6 +187,7 @@ static const BdrvChildClass child_job = {
void block_job_remove_all_bdrv(BlockJob *job)
{
+ assert(qemu_in_main_thread());
/*
* bdrv_root_unref_child() may reach child_job_[can_]set_aio_ctx(),
* which will also traverse job->nodes, so consume the list one by
@@ -207,6 +210,7 @@ void block_job_remove_all_bdrv(BlockJob *job)
bool block_job_has_bdrv(BlockJob *job, BlockDriverState *bs)
{
GSList *el;
+ assert(qemu_in_main_thread());
for (el = job->nodes; el; el = el->next) {
BdrvChild *c = el->data;
@@ -223,6 +227,7 @@ int block_job_add_bdrv(BlockJob *job, const char *name, BlockDriverState *bs,
{
BdrvChild *c;
bool need_context_ops;
+ assert(qemu_in_main_thread());
bdrv_ref(bs);
@@ -272,6 +277,8 @@ bool block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
const BlockJobDriver *drv = block_job_driver(job);
int64_t old_speed = job->speed;
+ assert(qemu_in_main_thread());
+
if (job_apply_verb(&job->job, JOB_VERB_SET_SPEED, errp) < 0) {
return false;
}
@@ -309,6 +316,8 @@ BlockJobInfo *block_job_query(BlockJob *job, Error **errp)
BlockJobInfo *info;
uint64_t progress_current, progress_total;
+ assert(qemu_in_main_thread());
+
if (block_job_is_internal(job)) {
error_setg(errp, "Cannot query QEMU internal jobs");
return NULL;
@@ -498,6 +507,7 @@ void *block_job_create(const char *job_id, const BlockJobDriver *driver,
void block_job_iostatus_reset(BlockJob *job)
{
+ assert(qemu_in_main_thread());
if (job->iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
return;
}
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 16/31] include/sysemu/blockdev.h: global state API
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (14 preceding siblings ...)
2021-11-24 6:44 ` [PATCH v5 15/31] assertions for blockjob.h " Emanuele Giuseppe Esposito
@ 2021-11-24 6:44 ` Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 17/31] assertions for blockdev.h " Emanuele Giuseppe Esposito
` (15 subsequent siblings)
31 siblings, 0 replies; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:44 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
blockdev functions run always under the BQL lock.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
include/sysemu/blockdev.h | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/include/sysemu/blockdev.h b/include/sysemu/blockdev.h
index c4b7b8b54e..e53eb91be6 100644
--- a/include/sysemu/blockdev.h
+++ b/include/sysemu/blockdev.h
@@ -13,9 +13,6 @@
#include "block/block.h"
#include "qemu/queue.h"
-void blockdev_mark_auto_del(BlockBackend *blk);
-void blockdev_auto_del(BlockBackend *blk);
-
typedef enum {
IF_DEFAULT = -1, /* for use with drive_add() only */
/*
@@ -40,6 +37,16 @@ struct DriveInfo {
QTAILQ_ENTRY(DriveInfo) next;
};
+/*
+ * Global state (GS) API. These functions run under the BQL lock.
+ *
+ * See include/block/block-global-state.h for more information about
+ * the GS API.
+ */
+
+void blockdev_mark_auto_del(BlockBackend *blk);
+void blockdev_auto_del(BlockBackend *blk);
+
DriveInfo *blk_legacy_dinfo(BlockBackend *blk);
DriveInfo *blk_set_legacy_dinfo(BlockBackend *blk, DriveInfo *dinfo);
BlockBackend *blk_by_legacy_dinfo(DriveInfo *dinfo);
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 17/31] assertions for blockdev.h global state API
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (15 preceding siblings ...)
2021-11-24 6:44 ` [PATCH v5 16/31] include/sysemu/blockdev.h: " Emanuele Giuseppe Esposito
@ 2021-11-24 6:44 ` Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 18/31] include/block/snapshot: global state API + assertions Emanuele Giuseppe Esposito
` (14 subsequent siblings)
31 siblings, 0 replies; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:44 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
block/block-backend.c | 3 +++
blockdev.c | 15 +++++++++++++++
2 files changed, 18 insertions(+)
diff --git a/block/block-backend.c b/block/block-backend.c
index 56670a774f..aad6d9a4c3 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -794,6 +794,7 @@ bool bdrv_is_root_node(BlockDriverState *bs)
*/
DriveInfo *blk_legacy_dinfo(BlockBackend *blk)
{
+ assert(qemu_in_main_thread());
return blk->legacy_dinfo;
}
@@ -805,6 +806,7 @@ DriveInfo *blk_legacy_dinfo(BlockBackend *blk)
DriveInfo *blk_set_legacy_dinfo(BlockBackend *blk, DriveInfo *dinfo)
{
assert(!blk->legacy_dinfo);
+ assert(qemu_in_main_thread());
return blk->legacy_dinfo = dinfo;
}
@@ -815,6 +817,7 @@ DriveInfo *blk_set_legacy_dinfo(BlockBackend *blk, DriveInfo *dinfo)
BlockBackend *blk_by_legacy_dinfo(DriveInfo *dinfo)
{
BlockBackend *blk = NULL;
+ assert(qemu_in_main_thread());
while ((blk = blk_next(blk)) != NULL) {
if (blk->legacy_dinfo == dinfo) {
diff --git a/blockdev.c b/blockdev.c
index 7706919410..eebd9317c2 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -113,6 +113,8 @@ void override_max_devs(BlockInterfaceType type, int max_devs)
BlockBackend *blk;
DriveInfo *dinfo;
+ assert(qemu_in_main_thread());
+
if (max_devs <= 0) {
return;
}
@@ -142,6 +144,8 @@ void blockdev_mark_auto_del(BlockBackend *blk)
DriveInfo *dinfo = blk_legacy_dinfo(blk);
BlockJob *job;
+ assert(qemu_in_main_thread());
+
if (!dinfo) {
return;
}
@@ -163,6 +167,7 @@ void blockdev_mark_auto_del(BlockBackend *blk)
void blockdev_auto_del(BlockBackend *blk)
{
DriveInfo *dinfo = blk_legacy_dinfo(blk);
+ assert(qemu_in_main_thread());
if (dinfo && dinfo->auto_del) {
monitor_remove_blk(blk);
@@ -187,6 +192,8 @@ DriveInfo *drive_get(BlockInterfaceType type, int bus, int unit)
BlockBackend *blk;
DriveInfo *dinfo;
+ assert(qemu_in_main_thread());
+
for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
dinfo = blk_legacy_dinfo(blk);
if (dinfo && dinfo->type == type
@@ -209,6 +216,8 @@ void drive_check_orphaned(void)
Location loc;
bool orphans = false;
+ assert(qemu_in_main_thread());
+
for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
dinfo = blk_legacy_dinfo(blk);
/*
@@ -242,6 +251,7 @@ void drive_check_orphaned(void)
DriveInfo *drive_get_by_index(BlockInterfaceType type, int index)
{
+ assert(qemu_in_main_thread());
return drive_get(type,
drive_index_to_bus_id(type, index),
drive_index_to_unit_id(type, index));
@@ -253,6 +263,8 @@ int drive_get_max_bus(BlockInterfaceType type)
BlockBackend *blk;
DriveInfo *dinfo;
+ assert(qemu_in_main_thread());
+
max_bus = -1;
for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
dinfo = blk_legacy_dinfo(blk);
@@ -269,6 +281,7 @@ int drive_get_max_bus(BlockInterfaceType type)
DriveInfo *drive_get_next(BlockInterfaceType type)
{
static int next_block_unit[IF_COUNT];
+ assert(qemu_in_main_thread());
return drive_get(type, 0, next_block_unit[type]++);
}
@@ -749,6 +762,8 @@ DriveInfo *drive_new(QemuOpts *all_opts, BlockInterfaceType block_default_type,
const char *filename;
int i;
+ assert(qemu_in_main_thread());
+
/* Change legacy command line options into QMP ones */
static const struct {
const char *from;
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 18/31] include/block/snapshot: global state API + assertions
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (16 preceding siblings ...)
2021-11-24 6:44 ` [PATCH v5 17/31] assertions for blockdev.h " Emanuele Giuseppe Esposito
@ 2021-11-24 6:44 ` Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 19/31] block/copy-before-write.h: " Emanuele Giuseppe Esposito
` (13 subsequent siblings)
31 siblings, 0 replies; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:44 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
Snapshots run also under the BQL lock, so they all are
in the global state API. The aiocontext lock that they hold
is currently an overkill and in future could be removed.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
include/block/snapshot.h | 13 +++++++++++--
block/snapshot.c | 28 ++++++++++++++++++++++++++++
migration/savevm.c | 2 ++
3 files changed, 41 insertions(+), 2 deletions(-)
diff --git a/include/block/snapshot.h b/include/block/snapshot.h
index 940345692f..cda82c1ba1 100644
--- a/include/block/snapshot.h
+++ b/include/block/snapshot.h
@@ -45,6 +45,13 @@ typedef struct QEMUSnapshotInfo {
uint64_t icount; /* record/replay step */
} QEMUSnapshotInfo;
+/*
+ * Global state (GS) API. These functions run under the BQL lock.
+ *
+ * See include/block/block-global-state.h for more information about
+ * the GS API.
+ */
+
int bdrv_snapshot_find(BlockDriverState *bs, QEMUSnapshotInfo *sn_info,
const char *name);
bool bdrv_snapshot_find_by_id_and_name(BlockDriverState *bs,
@@ -73,9 +80,11 @@ int bdrv_snapshot_load_tmp_by_id_or_name(BlockDriverState *bs,
Error **errp);
-/* Group operations. All block drivers are involved.
+/*
+ * Group operations. All block drivers are involved.
* These functions will properly handle dataplane (take aio_context_acquire
- * when appropriate for appropriate block drivers */
+ * when appropriate for appropriate block drivers
+ */
bool bdrv_all_can_snapshot(bool has_devices, strList *devices,
Error **errp);
diff --git a/block/snapshot.c b/block/snapshot.c
index ccacda8bd5..3dd3c9d3bd 100644
--- a/block/snapshot.c
+++ b/block/snapshot.c
@@ -57,6 +57,8 @@ int bdrv_snapshot_find(BlockDriverState *bs, QEMUSnapshotInfo *sn_info,
QEMUSnapshotInfo *sn_tab, *sn;
int nb_sns, i, ret;
+ assert(qemu_in_main_thread());
+
ret = -ENOENT;
nb_sns = bdrv_snapshot_list(bs, &sn_tab);
if (nb_sns < 0) {
@@ -105,6 +107,7 @@ bool bdrv_snapshot_find_by_id_and_name(BlockDriverState *bs,
bool ret = false;
assert(id || name);
+ assert(qemu_in_main_thread());
nb_sns = bdrv_snapshot_list(bs, &sn_tab);
if (nb_sns < 0) {
@@ -200,6 +203,7 @@ static BlockDriverState *bdrv_snapshot_fallback(BlockDriverState *bs)
int bdrv_can_snapshot(BlockDriverState *bs)
{
BlockDriver *drv = bs->drv;
+ assert(qemu_in_main_thread());
if (!drv || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
return 0;
}
@@ -220,6 +224,9 @@ int bdrv_snapshot_create(BlockDriverState *bs,
{
BlockDriver *drv = bs->drv;
BlockDriverState *fallback_bs = bdrv_snapshot_fallback(bs);
+
+ assert(qemu_in_main_thread());
+
if (!drv) {
return -ENOMEDIUM;
}
@@ -240,6 +247,8 @@ int bdrv_snapshot_goto(BlockDriverState *bs,
BdrvChild **fallback_ptr;
int ret, open_ret;
+ assert(qemu_in_main_thread());
+
if (!drv) {
error_setg(errp, "Block driver is closed");
return -ENOMEDIUM;
@@ -348,6 +357,8 @@ int bdrv_snapshot_delete(BlockDriverState *bs,
BlockDriverState *fallback_bs = bdrv_snapshot_fallback(bs);
int ret;
+ assert(qemu_in_main_thread());
+
if (!drv) {
error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, bdrv_get_device_name(bs));
return -ENOMEDIUM;
@@ -380,6 +391,8 @@ int bdrv_snapshot_list(BlockDriverState *bs,
{
BlockDriver *drv = bs->drv;
BlockDriverState *fallback_bs = bdrv_snapshot_fallback(bs);
+
+ assert(qemu_in_main_thread());
if (!drv) {
return -ENOMEDIUM;
}
@@ -419,6 +432,8 @@ int bdrv_snapshot_load_tmp(BlockDriverState *bs,
{
BlockDriver *drv = bs->drv;
+ assert(qemu_in_main_thread());
+
if (!drv) {
error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, bdrv_get_device_name(bs));
return -ENOMEDIUM;
@@ -447,6 +462,8 @@ int bdrv_snapshot_load_tmp_by_id_or_name(BlockDriverState *bs,
int ret;
Error *local_err = NULL;
+ assert(qemu_in_main_thread());
+
ret = bdrv_snapshot_load_tmp(bs, id_or_name, NULL, &local_err);
if (ret == -ENOENT || ret == -EINVAL) {
error_free(local_err);
@@ -515,6 +532,8 @@ bool bdrv_all_can_snapshot(bool has_devices, strList *devices,
g_autoptr(GList) bdrvs = NULL;
GList *iterbdrvs;
+ assert(qemu_in_main_thread());
+
if (bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, errp) < 0) {
return false;
}
@@ -549,6 +568,8 @@ int bdrv_all_delete_snapshot(const char *name,
g_autoptr(GList) bdrvs = NULL;
GList *iterbdrvs;
+ assert(qemu_in_main_thread());
+
if (bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, errp) < 0) {
return -1;
}
@@ -588,6 +609,8 @@ int bdrv_all_goto_snapshot(const char *name,
g_autoptr(GList) bdrvs = NULL;
GList *iterbdrvs;
+ assert(qemu_in_main_thread());
+
if (bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, errp) < 0) {
return -1;
}
@@ -622,6 +645,8 @@ int bdrv_all_has_snapshot(const char *name,
g_autoptr(GList) bdrvs = NULL;
GList *iterbdrvs;
+ assert(qemu_in_main_thread());
+
if (bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, errp) < 0) {
return -1;
}
@@ -663,6 +688,7 @@ int bdrv_all_create_snapshot(QEMUSnapshotInfo *sn,
{
g_autoptr(GList) bdrvs = NULL;
GList *iterbdrvs;
+ assert(qemu_in_main_thread());
if (bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, errp) < 0) {
return -1;
@@ -703,6 +729,8 @@ BlockDriverState *bdrv_all_find_vmstate_bs(const char *vmstate_bs,
g_autoptr(GList) bdrvs = NULL;
GList *iterbdrvs;
+ assert(qemu_in_main_thread());
+
if (bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, errp) < 0) {
return NULL;
}
diff --git a/migration/savevm.c b/migration/savevm.c
index d59e976d50..d4bc226caa 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -2786,6 +2786,8 @@ bool save_snapshot(const char *name, bool overwrite, const char *vmstate,
g_autoptr(GDateTime) now = g_date_time_new_now_local();
AioContext *aio_context;
+ assert(qemu_in_main_thread());
+
if (migration_is_blocked(errp)) {
return false;
}
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 19/31] block/copy-before-write.h: global state API + assertions
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (17 preceding siblings ...)
2021-11-24 6:44 ` [PATCH v5 18/31] include/block/snapshot: global state API + assertions Emanuele Giuseppe Esposito
@ 2021-11-24 6:44 ` Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 20/31] block/coroutines: I/O API Emanuele Giuseppe Esposito
` (12 subsequent siblings)
31 siblings, 0 replies; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:44 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
copy-before-write functions always run under BQL lock.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
block/copy-before-write.h | 7 +++++++
block/copy-before-write.c | 2 ++
2 files changed, 9 insertions(+)
diff --git a/block/copy-before-write.h b/block/copy-before-write.h
index 51847e711a..9a45de2fce 100644
--- a/block/copy-before-write.h
+++ b/block/copy-before-write.h
@@ -29,6 +29,13 @@
#include "block/block_int.h"
#include "block/block-copy.h"
+/*
+ * Global state (GS) API. These functions run under the BQL lock.
+ *
+ * See include/block/block-global-state.h for more information about
+ * the GS API.
+ */
+
BlockDriverState *bdrv_cbw_append(BlockDriverState *source,
BlockDriverState *target,
const char *filter_node_name,
diff --git a/block/copy-before-write.c b/block/copy-before-write.c
index c30a5ff8de..36a8d7ba52 100644
--- a/block/copy-before-write.c
+++ b/block/copy-before-write.c
@@ -223,6 +223,7 @@ BlockDriverState *bdrv_cbw_append(BlockDriverState *source,
QDict *opts;
assert(source->total_sectors == target->total_sectors);
+ assert(qemu_in_main_thread());
opts = qdict_new();
qdict_put_str(opts, "driver", "copy-before-write");
@@ -245,6 +246,7 @@ BlockDriverState *bdrv_cbw_append(BlockDriverState *source,
void bdrv_cbw_drop(BlockDriverState *bs)
{
+ assert(qemu_in_main_thread());
bdrv_drop_filter(bs, &error_abort);
bdrv_unref(bs);
}
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 20/31] block/coroutines: I/O API
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (18 preceding siblings ...)
2021-11-24 6:44 ` [PATCH v5 19/31] block/copy-before-write.h: " Emanuele Giuseppe Esposito
@ 2021-11-24 6:44 ` Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 21/31] block_int-common.h: split function pointers in BlockDriver Emanuele Giuseppe Esposito
` (11 subsequent siblings)
31 siblings, 0 replies; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:44 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
block coroutines functions run in different aiocontext, and are
not protected by the BQL. Therefore are I/O.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
block/coroutines.h | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/block/coroutines.h b/block/coroutines.h
index c8c14a29c8..c61abd271a 100644
--- a/block/coroutines.h
+++ b/block/coroutines.h
@@ -29,6 +29,12 @@
/* For blk_bs() in generated block/block-gen.c */
#include "sysemu/block-backend.h"
+/*
+ * I/O API functions. These functions are thread-safe.
+ *
+ * See include/block/block-io.h for more information about
+ * the I/O API.
+ */
int coroutine_fn bdrv_co_check(BlockDriverState *bs,
BdrvCheckResult *res, BdrvCheckMode fix);
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 21/31] block_int-common.h: split function pointers in BlockDriver
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (19 preceding siblings ...)
2021-11-24 6:44 ` [PATCH v5 20/31] block/coroutines: I/O API Emanuele Giuseppe Esposito
@ 2021-11-24 6:44 ` Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 22/31] block_int-common.h: assertion in the callers of BlockDriver function pointers Emanuele Giuseppe Esposito
` (10 subsequent siblings)
31 siblings, 0 replies; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:44 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
Similar to the header split, also the function pointers in BlockDriver
can be split in I/O and global state.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
include/block/block_int-common.h | 440 +++++++++++++++++--------------
1 file changed, 235 insertions(+), 205 deletions(-)
diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h
index 70534f94ae..0e63dc694f 100644
--- a/include/block/block_int-common.h
+++ b/include/block/block_int-common.h
@@ -96,6 +96,11 @@ typedef struct BdrvTrackedRequest {
struct BlockDriver {
+ /*
+ * These fields are initialized when this object is created,
+ * and are never changed afterwards.
+ */
+
const char *format_name;
int instance_size;
@@ -121,23 +126,7 @@ struct BlockDriver {
* on those children.
*/
bool is_format;
- /*
- * Return true if @to_replace can be replaced by a BDS with the
- * same data as @bs without it affecting @bs's behavior (that is,
- * without it being visible to @bs's parents).
- */
- bool (*bdrv_recurse_can_replace)(BlockDriverState *bs,
- BlockDriverState *to_replace);
-
- int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
- int (*bdrv_probe_device)(const char *filename);
- /*
- * Any driver implementing this callback is expected to be able to handle
- * NULL file names in its .bdrv_open() implementation.
- */
- void (*bdrv_parse_filename)(const char *filename, QDict *options,
- Error **errp);
/*
* Drivers not implementing bdrv_parse_filename nor bdrv_open should have
* this field set to true, except ones that are defined only by their
@@ -159,7 +148,66 @@ struct BlockDriver {
*/
bool supports_backing;
- /* For handling image reopen for split or non-split files */
+ bool has_variable_length;
+
+ /*
+ * Drivers setting this field must be able to work with just a plain
+ * filename with '<protocol_name>:' as a prefix, and no other options.
+ * Options may be extracted from the filename by implementing
+ * bdrv_parse_filename.
+ */
+ const char *protocol_name;
+
+ /* List of options for creating images, terminated by name == NULL */
+ QemuOptsList *create_opts;
+
+ /* List of options for image amend */
+ QemuOptsList *amend_opts;
+
+ /*
+ * If this driver supports reopening images this contains a
+ * NULL-terminated list of the runtime options that can be
+ * modified. If an option in this list is unspecified during
+ * reopen then it _must_ be reset to its default value or return
+ * an error.
+ */
+ const char *const *mutable_opts;
+
+ /*
+ * Pointer to a NULL-terminated array of names of strong options
+ * that can be specified for bdrv_open(). A strong option is one
+ * that changes the data of a BDS.
+ * If this pointer is NULL, the array is considered empty.
+ * "filename" and "driver" are always considered strong.
+ */
+ const char *const *strong_runtime_opts;
+
+ /*
+ * Global state (GS) API. These functions run under the BQL lock.
+ *
+ * See include/block/block-global-state.h for more information about
+ * the GS API.
+ */
+
+ /*
+ * Return true if @to_replace can be replaced by a BDS with the
+ * same data as @bs without it affecting @bs's behavior (that is,
+ * without it being visible to @bs's parents).
+ */
+ bool (*bdrv_recurse_can_replace)(BlockDriverState *bs,
+ BlockDriverState *to_replace);
+
+ int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
+ int (*bdrv_probe_device)(const char *filename);
+
+ /*
+ * Any driver implementing this callback is expected to be able to handle
+ * NULL file names in its .bdrv_open() implementation.
+ */
+ void (*bdrv_parse_filename)(const char *filename, QDict *options,
+ Error **errp);
+
+ /* For handling image reopen for split or non-split files. */
int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state,
BlockReopenQueue *queue, Error **errp);
void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state);
@@ -175,7 +223,6 @@ struct BlockDriver {
Error **errp);
void (*bdrv_close)(BlockDriverState *bs);
-
int coroutine_fn (*bdrv_co_create)(BlockdevCreateOptions *opts,
Error **errp);
int coroutine_fn (*bdrv_co_create_opts)(BlockDriver *drv,
@@ -183,11 +230,6 @@ struct BlockDriver {
QemuOpts *opts,
Error **errp);
- int coroutine_fn (*bdrv_co_amend)(BlockDriverState *bs,
- BlockdevAmendOptions *opts,
- bool force,
- Error **errp);
-
int (*bdrv_amend_options)(BlockDriverState *bs,
QemuOpts *opts,
BlockDriverAmendStatusCB *status_cb,
@@ -234,6 +276,176 @@ struct BlockDriver {
*/
char *(*bdrv_dirname)(BlockDriverState *bs, Error **errp);
+ /*
+ * This informs the driver that we are no longer interested in the result
+ * of in-flight requests, so don't waste the time if possible.
+ *
+ * One example usage is to avoid waiting for an nbd target node reconnect
+ * timeout during job-cancel with force=true.
+ */
+ void (*bdrv_cancel_in_flight)(BlockDriverState *bs);
+
+ int (*bdrv_inactivate)(BlockDriverState *bs);
+
+ int (*bdrv_snapshot_create)(BlockDriverState *bs,
+ QEMUSnapshotInfo *sn_info);
+ int (*bdrv_snapshot_goto)(BlockDriverState *bs,
+ const char *snapshot_id);
+ int (*bdrv_snapshot_delete)(BlockDriverState *bs,
+ const char *snapshot_id,
+ const char *name,
+ Error **errp);
+ int (*bdrv_snapshot_list)(BlockDriverState *bs,
+ QEMUSnapshotInfo **psn_info);
+ int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
+ const char *snapshot_id,
+ const char *name,
+ Error **errp);
+
+ int (*bdrv_change_backing_file)(BlockDriverState *bs,
+ const char *backing_file, const char *backing_fmt);
+
+ /* removable device specific */
+ void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
+ void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
+
+ /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */
+ int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event,
+ const char *tag);
+ int (*bdrv_debug_remove_breakpoint)(BlockDriverState *bs,
+ const char *tag);
+ int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag);
+ bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag);
+
+ void (*bdrv_refresh_limits)(BlockDriverState *bs, Error **errp);
+
+ /*
+ * Returns 1 if newly created images are guaranteed to contain only
+ * zeros, 0 otherwise.
+ */
+ int (*bdrv_has_zero_init)(BlockDriverState *bs);
+
+ /*
+ * Remove fd handlers, timers, and other event loop callbacks so the event
+ * loop is no longer in use. Called with no in-flight requests and in
+ * depth-first traversal order with parents before child nodes.
+ */
+ void (*bdrv_detach_aio_context)(BlockDriverState *bs);
+
+ /*
+ * Add fd handlers, timers, and other event loop callbacks so I/O requests
+ * can be processed again. Called with no in-flight requests and in
+ * depth-first traversal order with child nodes before parent nodes.
+ */
+ void (*bdrv_attach_aio_context)(BlockDriverState *bs,
+ AioContext *new_context);
+
+ /**
+ * Try to get @bs's logical and physical block size.
+ * On success, store them in @bsz and return zero.
+ * On failure, return negative errno.
+ */
+ int (*bdrv_probe_blocksizes)(BlockDriverState *bs, BlockSizes *bsz);
+ /**
+ * Try to get @bs's geometry (cyls, heads, sectors)
+ * On success, store them in @geo and return 0.
+ * On failure return -errno.
+ * Only drivers that want to override guest geometry implement this
+ * callback; see hd_geometry_guess().
+ */
+ int (*bdrv_probe_geometry)(BlockDriverState *bs, HDGeometry *geo);
+
+ void (*bdrv_add_child)(BlockDriverState *parent, BlockDriverState *child,
+ Error **errp);
+ void (*bdrv_del_child)(BlockDriverState *parent, BdrvChild *child,
+ Error **errp);
+
+ /**
+ * Informs the block driver that a permission change is intended. The
+ * driver checks whether the change is permissible and may take other
+ * preparations for the change (e.g. get file system locks). This operation
+ * is always followed either by a call to either .bdrv_set_perm or
+ * .bdrv_abort_perm_update.
+ *
+ * Checks whether the requested set of cumulative permissions in @perm
+ * can be granted for accessing @bs and whether no other users are using
+ * permissions other than those given in @shared (both arguments take
+ * BLK_PERM_* bitmasks).
+ *
+ * If both conditions are met, 0 is returned. Otherwise, -errno is returned
+ * and errp is set to an error describing the conflict.
+ */
+ int (*bdrv_check_perm)(BlockDriverState *bs, uint64_t perm,
+ uint64_t shared, Error **errp);
+
+ /**
+ * Called to inform the driver that the set of cumulative set of used
+ * permissions for @bs has changed to @perm, and the set of sharable
+ * permission to @shared. The driver can use this to propagate changes to
+ * its children (i.e. request permissions only if a parent actually needs
+ * them).
+ *
+ * This function is only invoked after bdrv_check_perm(), so block drivers
+ * may rely on preparations made in their .bdrv_check_perm implementation.
+ */
+ void (*bdrv_set_perm)(BlockDriverState *bs, uint64_t perm, uint64_t shared);
+
+ /*
+ * Called to inform the driver that after a previous bdrv_check_perm()
+ * call, the permission update is not performed and any preparations made
+ * for it (e.g. taken file locks) need to be undone.
+ *
+ * This function can be called even for nodes that never saw a
+ * bdrv_check_perm() call. It is a no-op then.
+ */
+ void (*bdrv_abort_perm_update)(BlockDriverState *bs);
+
+ /**
+ * Returns in @nperm and @nshared the permissions that the driver for @bs
+ * needs on its child @c, based on the cumulative permissions requested by
+ * the parents in @parent_perm and @parent_shared.
+ *
+ * If @c is NULL, return the permissions for attaching a new child for the
+ * given @child_class and @role.
+ *
+ * If @reopen_queue is non-NULL, don't return the currently needed
+ * permissions, but those that will be needed after applying the
+ * @reopen_queue.
+ */
+ void (*bdrv_child_perm)(BlockDriverState *bs, BdrvChild *c,
+ BdrvChildRole role,
+ BlockReopenQueue *reopen_queue,
+ uint64_t parent_perm, uint64_t parent_shared,
+ uint64_t *nperm, uint64_t *nshared);
+
+ /**
+ * Register/unregister a buffer for I/O. For example, when the driver is
+ * interested to know the memory areas that will later be used in iovs, so
+ * that it can do IOMMU mapping with VFIO etc., in order to get better
+ * performance. In the case of VFIO drivers, this callback is used to do
+ * DMA mapping for hot buffers.
+ */
+ void (*bdrv_register_buf)(BlockDriverState *bs, void *host, size_t size);
+ void (*bdrv_unregister_buf)(BlockDriverState *bs, void *host);
+
+ /*
+ * This field is modified only under the BQL, and is part of
+ * the global state.
+ */
+ QLIST_ENTRY(BlockDriver) list;
+
+ /*
+ * I/O API functions. These functions are thread-safe.
+ *
+ * See include/block/block-io.h for more information about
+ * the I/O API.
+ */
+
+ int coroutine_fn (*bdrv_co_amend)(BlockDriverState *bs,
+ BlockdevAmendOptions *opts,
+ bool force,
+ Error **errp);
+
/* aio */
BlockAIOCB *(*bdrv_aio_preadv)(BlockDriverState *bs,
int64_t offset, int64_t bytes, QEMUIOVector *qiov,
@@ -374,21 +586,11 @@ struct BlockDriver {
bool want_zero, int64_t offset, int64_t bytes, int64_t *pnum,
int64_t *map, BlockDriverState **file);
- /*
- * This informs the driver that we are no longer interested in the result
- * of in-flight requests, so don't waste the time if possible.
- *
- * One example usage is to avoid waiting for an nbd target node reconnect
- * timeout during job-cancel with force=true.
- */
- void (*bdrv_cancel_in_flight)(BlockDriverState *bs);
-
/*
* Invalidate any cached meta-data.
*/
void coroutine_fn (*bdrv_co_invalidate_cache)(BlockDriverState *bs,
Error **errp);
- int (*bdrv_inactivate)(BlockDriverState *bs);
/*
* Flushes all data for all layers by calling bdrv_co_flush for underlying
@@ -414,14 +616,6 @@ struct BlockDriver {
*/
int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);
- /*
- * Drivers setting this field must be able to work with just a plain
- * filename with '<protocol_name>:' as a prefix, and no other options.
- * Options may be extracted from the filename by implementing
- * bdrv_parse_filename.
- */
- const char *protocol_name;
-
/*
* Truncate @bs to @offset bytes using the given @prealloc mode
* when growing. Modes other than PREALLOC_MODE_OFF should be
@@ -439,7 +633,6 @@ struct BlockDriver {
bool exact, PreallocMode prealloc,
BdrvRequestFlags flags, Error **errp);
int64_t (*bdrv_getlength)(BlockDriverState *bs);
- bool has_variable_length;
int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);
BlockMeasureInfo *(*bdrv_measure)(QemuOpts *opts, BlockDriverState *in_bs,
Error **errp);
@@ -450,20 +643,6 @@ struct BlockDriver {
int64_t offset, int64_t bytes, QEMUIOVector *qiov,
size_t qiov_offset);
- int (*bdrv_snapshot_create)(BlockDriverState *bs,
- QEMUSnapshotInfo *sn_info);
- int (*bdrv_snapshot_goto)(BlockDriverState *bs,
- const char *snapshot_id);
- int (*bdrv_snapshot_delete)(BlockDriverState *bs,
- const char *snapshot_id,
- const char *name,
- Error **errp);
- int (*bdrv_snapshot_list)(BlockDriverState *bs,
- QEMUSnapshotInfo **psn_info);
- int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
- const char *snapshot_id,
- const char *name,
- Error **errp);
int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs,
@@ -477,13 +656,8 @@ struct BlockDriver {
QEMUIOVector *qiov,
int64_t pos);
- int (*bdrv_change_backing_file)(BlockDriverState *bs,
- const char *backing_file, const char *backing_fmt);
-
/* removable device specific */
bool (*bdrv_is_inserted)(BlockDriverState *bs);
- void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
- void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
/* to control generic scsi devices */
BlockAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
@@ -492,21 +666,6 @@ struct BlockDriver {
int coroutine_fn (*bdrv_co_ioctl)(BlockDriverState *bs,
unsigned long int req, void *buf);
- /* List of options for creating images, terminated by name == NULL */
- QemuOptsList *create_opts;
-
- /* List of options for image amend */
- QemuOptsList *amend_opts;
-
- /*
- * If this driver supports reopening images this contains a
- * NULL-terminated list of the runtime options that can be
- * modified. If an option in this list is unspecified during
- * reopen then it _must_ be reset to its default value or return
- * an error.
- */
- const char *const *mutable_opts;
-
/*
* Returns 0 for completed check, -errno for internal errors.
* The check results are stored in result.
@@ -517,56 +676,10 @@ struct BlockDriver {
void (*bdrv_debug_event)(BlockDriverState *bs, BlkdebugEvent event);
- /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */
- int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event,
- const char *tag);
- int (*bdrv_debug_remove_breakpoint)(BlockDriverState *bs,
- const char *tag);
- int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag);
- bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag);
-
- void (*bdrv_refresh_limits)(BlockDriverState *bs, Error **errp);
-
- /*
- * Returns 1 if newly created images are guaranteed to contain only
- * zeros, 0 otherwise.
- */
- int (*bdrv_has_zero_init)(BlockDriverState *bs);
-
- /*
- * Remove fd handlers, timers, and other event loop callbacks so the event
- * loop is no longer in use. Called with no in-flight requests and in
- * depth-first traversal order with parents before child nodes.
- */
- void (*bdrv_detach_aio_context)(BlockDriverState *bs);
-
- /*
- * Add fd handlers, timers, and other event loop callbacks so I/O requests
- * can be processed again. Called with no in-flight requests and in
- * depth-first traversal order with child nodes before parent nodes.
- */
- void (*bdrv_attach_aio_context)(BlockDriverState *bs,
- AioContext *new_context);
-
/* io queue for linux-aio */
void (*bdrv_io_plug)(BlockDriverState *bs);
void (*bdrv_io_unplug)(BlockDriverState *bs);
- /**
- * Try to get @bs's logical and physical block size.
- * On success, store them in @bsz and return zero.
- * On failure, return negative errno.
- */
- int (*bdrv_probe_blocksizes)(BlockDriverState *bs, BlockSizes *bsz);
- /**
- * Try to get @bs's geometry (cyls, heads, sectors)
- * On success, store them in @geo and return 0.
- * On failure return -errno.
- * Only drivers that want to override guest geometry implement this
- * callback; see hd_geometry_guess().
- */
- int (*bdrv_probe_geometry)(BlockDriverState *bs, HDGeometry *geo);
-
/**
* bdrv_co_drain_begin is called if implemented in the beginning of a
* drain operation to drain and stop any internal sources of requests in
@@ -580,69 +693,6 @@ struct BlockDriver {
void coroutine_fn (*bdrv_co_drain_begin)(BlockDriverState *bs);
void coroutine_fn (*bdrv_co_drain_end)(BlockDriverState *bs);
- void (*bdrv_add_child)(BlockDriverState *parent, BlockDriverState *child,
- Error **errp);
- void (*bdrv_del_child)(BlockDriverState *parent, BdrvChild *child,
- Error **errp);
-
- /**
- * Informs the block driver that a permission change is intended. The
- * driver checks whether the change is permissible and may take other
- * preparations for the change (e.g. get file system locks). This operation
- * is always followed either by a call to either .bdrv_set_perm or
- * .bdrv_abort_perm_update.
- *
- * Checks whether the requested set of cumulative permissions in @perm
- * can be granted for accessing @bs and whether no other users are using
- * permissions other than those given in @shared (both arguments take
- * BLK_PERM_* bitmasks).
- *
- * If both conditions are met, 0 is returned. Otherwise, -errno is returned
- * and errp is set to an error describing the conflict.
- */
- int (*bdrv_check_perm)(BlockDriverState *bs, uint64_t perm,
- uint64_t shared, Error **errp);
-
- /**
- * Called to inform the driver that the set of cumulative set of used
- * permissions for @bs has changed to @perm, and the set of sharable
- * permission to @shared. The driver can use this to propagate changes to
- * its children (i.e. request permissions only if a parent actually needs
- * them).
- *
- * This function is only invoked after bdrv_check_perm(), so block drivers
- * may rely on preparations made in their .bdrv_check_perm implementation.
- */
- void (*bdrv_set_perm)(BlockDriverState *bs, uint64_t perm, uint64_t shared);
-
- /*
- * Called to inform the driver that after a previous bdrv_check_perm()
- * call, the permission update is not performed and any preparations made
- * for it (e.g. taken file locks) need to be undone.
- *
- * This function can be called even for nodes that never saw a
- * bdrv_check_perm() call. It is a no-op then.
- */
- void (*bdrv_abort_perm_update)(BlockDriverState *bs);
-
- /**
- * Returns in @nperm and @nshared the permissions that the driver for @bs
- * needs on its child @c, based on the cumulative permissions requested by
- * the parents in @parent_perm and @parent_shared.
- *
- * If @c is NULL, return the permissions for attaching a new child for the
- * given @child_class and @role.
- *
- * If @reopen_queue is non-NULL, don't return the currently needed
- * permissions, but those that will be needed after applying the
- * @reopen_queue.
- */
- void (*bdrv_child_perm)(BlockDriverState *bs, BdrvChild *c,
- BdrvChildRole role,
- BlockReopenQueue *reopen_queue,
- uint64_t parent_perm, uint64_t parent_shared,
- uint64_t *nperm, uint64_t *nshared);
-
bool (*bdrv_supports_persistent_dirty_bitmap)(BlockDriverState *bs);
bool (*bdrv_co_can_store_new_dirty_bitmap)(BlockDriverState *bs,
const char *name,
@@ -651,26 +701,6 @@ struct BlockDriver {
int (*bdrv_co_remove_persistent_dirty_bitmap)(BlockDriverState *bs,
const char *name,
Error **errp);
-
- /**
- * Register/unregister a buffer for I/O. For example, when the driver is
- * interested to know the memory areas that will later be used in iovs, so
- * that it can do IOMMU mapping with VFIO etc., in order to get better
- * performance. In the case of VFIO drivers, this callback is used to do
- * DMA mapping for hot buffers.
- */
- void (*bdrv_register_buf)(BlockDriverState *bs, void *host, size_t size);
- void (*bdrv_unregister_buf)(BlockDriverState *bs, void *host);
- QLIST_ENTRY(BlockDriver) list;
-
- /*
- * Pointer to a NULL-terminated array of names of strong options
- * that can be specified for bdrv_open(). A strong option is one
- * that changes the data of a BDS.
- * If this pointer is NULL, the array is considered empty.
- * "filename" and "driver" are always considered strong.
- */
- const char *const *strong_runtime_opts;
};
static inline bool block_driver_can_compress(BlockDriver *drv)
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 22/31] block_int-common.h: assertion in the callers of BlockDriver function pointers
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (20 preceding siblings ...)
2021-11-24 6:44 ` [PATCH v5 21/31] block_int-common.h: split function pointers in BlockDriver Emanuele Giuseppe Esposito
@ 2021-11-24 6:44 ` Emanuele Giuseppe Esposito
2021-12-16 18:43 ` Hanna Reitz
2021-11-24 6:44 ` [PATCH v5 23/31] block_int-common.h: split function pointers in BdrvChildClass Emanuele Giuseppe Esposito
` (9 subsequent siblings)
31 siblings, 1 reply; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:44 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
block.c | 18 ++++++++++++++++++
block/create.c | 10 ++++++++++
2 files changed, 28 insertions(+)
diff --git a/block.c b/block.c
index b77ab0a104..180884b8c0 100644
--- a/block.c
+++ b/block.c
@@ -526,6 +526,7 @@ static void coroutine_fn bdrv_create_co_entry(void *opaque)
CreateCo *cco = opaque;
assert(cco->drv);
+ assert(qemu_in_main_thread());
ret = cco->drv->bdrv_co_create_opts(cco->drv,
cco->filename, cco->opts, &local_err);
@@ -1090,6 +1091,7 @@ int refresh_total_sectors(BlockDriverState *bs, int64_t hint)
static void bdrv_join_options(BlockDriverState *bs, QDict *options,
QDict *old_options)
{
+ assert(qemu_in_main_thread());
if (bs->drv && bs->drv->bdrv_join_options) {
bs->drv->bdrv_join_options(options, old_options);
} else {
@@ -1598,6 +1600,7 @@ static int bdrv_open_driver(BlockDriverState *bs, BlockDriver *drv,
{
Error *local_err = NULL;
int i, ret;
+ assert(qemu_in_main_thread());
bdrv_assign_node_name(bs, node_name, &local_err);
if (local_err) {
@@ -1989,6 +1992,8 @@ static int bdrv_fill_options(QDict **options, const char *filename,
BlockDriver *drv = NULL;
Error *local_err = NULL;
+ assert(qemu_in_main_thread());
+
/*
* Caution: while qdict_get_try_str() is fine, getting non-string
* types would require more care. When @options come from
@@ -2182,6 +2187,7 @@ static void bdrv_child_perm(BlockDriverState *bs, BlockDriverState *child_bs,
uint64_t *nperm, uint64_t *nshared)
{
assert(bs->drv && bs->drv->bdrv_child_perm);
+ assert(qemu_in_main_thread());
bs->drv->bdrv_child_perm(bs, c, role, reopen_queue,
parent_perm, parent_shared,
nperm, nshared);
@@ -2267,6 +2273,7 @@ static void bdrv_drv_set_perm_commit(void *opaque)
{
BlockDriverState *bs = opaque;
uint64_t cumulative_perms, cumulative_shared_perms;
+ assert(qemu_in_main_thread());
if (bs->drv->bdrv_set_perm) {
bdrv_get_cumulative_perm(bs, &cumulative_perms,
@@ -2278,6 +2285,7 @@ static void bdrv_drv_set_perm_commit(void *opaque)
static void bdrv_drv_set_perm_abort(void *opaque)
{
BlockDriverState *bs = opaque;
+ assert(qemu_in_main_thread());
if (bs->drv->bdrv_abort_perm_update) {
bs->drv->bdrv_abort_perm_update(bs);
@@ -2293,6 +2301,7 @@ static int bdrv_drv_set_perm(BlockDriverState *bs, uint64_t perm,
uint64_t shared_perm, Transaction *tran,
Error **errp)
{
+ assert(qemu_in_main_thread());
if (!bs->drv) {
return 0;
}
@@ -4357,6 +4366,7 @@ int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp)
assert(qemu_get_current_aio_context() == qemu_get_aio_context());
assert(bs_queue != NULL);
+ assert(qemu_in_main_thread());
QTAILQ_FOREACH(bs_entry, bs_queue, entry) {
ctx = bdrv_get_aio_context(bs_entry->state.bs);
@@ -4622,6 +4632,7 @@ static int bdrv_reopen_prepare(BDRVReopenState *reopen_state,
assert(reopen_state != NULL);
assert(reopen_state->bs->drv != NULL);
+ assert(qemu_in_main_thread());
drv = reopen_state->bs->drv;
/* This function and each driver's bdrv_reopen_prepare() remove
@@ -4832,6 +4843,7 @@ static void bdrv_reopen_commit(BDRVReopenState *reopen_state)
bs = reopen_state->bs;
drv = bs->drv;
assert(drv != NULL);
+ assert(qemu_in_main_thread());
/* If there are any driver level actions to take */
if (drv->bdrv_reopen_commit) {
@@ -4873,6 +4885,7 @@ static void bdrv_reopen_abort(BDRVReopenState *reopen_state)
assert(reopen_state != NULL);
drv = reopen_state->bs->drv;
assert(drv != NULL);
+ assert(qemu_in_main_thread());
if (drv->bdrv_reopen_abort) {
drv->bdrv_reopen_abort(reopen_state);
@@ -4886,6 +4899,7 @@ static void bdrv_close(BlockDriverState *bs)
BdrvChild *child, *next;
assert(!bs->refcnt);
+ assert(qemu_in_main_thread());
bdrv_drained_begin(bs); /* complete I/O */
bdrv_flush(bs);
@@ -6671,6 +6685,8 @@ static int bdrv_inactivate_recurse(BlockDriverState *bs)
int ret;
uint64_t cumulative_perms, cumulative_shared_perms;
+ assert(qemu_in_main_thread());
+
if (!bs->drv) {
return -ENOMEDIUM;
}
@@ -7180,6 +7196,7 @@ static void bdrv_detach_aio_context(BlockDriverState *bs)
BdrvAioNotifier *baf, *baf_tmp;
assert(!bs->walking_aio_notifiers);
+ assert(qemu_in_main_thread());
bs->walking_aio_notifiers = true;
QLIST_FOREACH_SAFE(baf, &bs->aio_notifiers, list, baf_tmp) {
if (baf->deleted) {
@@ -7207,6 +7224,7 @@ static void bdrv_attach_aio_context(BlockDriverState *bs,
AioContext *new_context)
{
BdrvAioNotifier *ban, *ban_tmp;
+ assert(qemu_in_main_thread());
if (bs->quiesce_counter) {
aio_disable_external(new_context);
diff --git a/block/create.c b/block/create.c
index 89812669df..0167118579 100644
--- a/block/create.c
+++ b/block/create.c
@@ -42,6 +42,16 @@ static int coroutine_fn blockdev_create_run(Job *job, Error **errp)
BlockdevCreateJob *s = container_of(job, BlockdevCreateJob, common);
int ret;
+ /*
+ * Currently there is nothing preventing this
+ * function from being called in an iothread context.
+ * However, since it will crash anyways because of the
+ * aiocontext lock not taken, we might as well make it
+ * crash with a more meaningful error, by checking that
+ * we are in the main loop
+ */
+ assert(qemu_in_main_thread());
+
job_progress_set_remaining(&s->common, 1);
ret = s->drv->bdrv_co_create(s->opts, errp);
job_progress_update(&s->common, 1);
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 23/31] block_int-common.h: split function pointers in BdrvChildClass
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (21 preceding siblings ...)
2021-11-24 6:44 ` [PATCH v5 22/31] block_int-common.h: assertion in the callers of BlockDriver function pointers Emanuele Giuseppe Esposito
@ 2021-11-24 6:44 ` Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 24/31] block_int-common.h: assertions in the callers of BdrvChildClass function pointers Emanuele Giuseppe Esposito
` (8 subsequent siblings)
31 siblings, 0 replies; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:44 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
include/block/block_int-common.h | 67 +++++++++++++++++++-------------
1 file changed, 40 insertions(+), 27 deletions(-)
diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h
index 0e63dc694f..3ceb2365a8 100644
--- a/include/block/block_int-common.h
+++ b/include/block/block_int-common.h
@@ -817,12 +817,16 @@ struct BdrvChildClass {
*/
bool parent_is_bds;
+ /*
+ * Global state (GS) API. These functions run under the BQL lock.
+ *
+ * See include/block/block-global-state.h for more information about
+ * the GS API.
+ */
void (*inherit_options)(BdrvChildRole role, bool parent_is_format,
int *child_flags, QDict *child_options,
int parent_flags, QDict *parent_options);
-
void (*change_media)(BdrvChild *child, bool load);
- void (*resize)(BdrvChild *child);
/*
* Returns a name that is supposedly more useful for human users than the
@@ -839,6 +843,40 @@ struct BdrvChildClass {
*/
char *(*get_parent_desc)(BdrvChild *child);
+ /*
+ * Notifies the parent that the child has been activated/inactivated (e.g.
+ * when migration is completing) and it can start/stop requesting
+ * permissions and doing I/O on it.
+ */
+ void (*activate)(BdrvChild *child, Error **errp);
+ int (*inactivate)(BdrvChild *child);
+
+ void (*attach)(BdrvChild *child);
+ void (*detach)(BdrvChild *child);
+
+ /*
+ * Notifies the parent that the filename of its child has changed (e.g.
+ * because the direct child was removed from the backing chain), so that it
+ * can update its reference.
+ */
+ int (*update_filename)(BdrvChild *child, BlockDriverState *new_base,
+ const char *filename, Error **errp);
+
+ bool (*can_set_aio_ctx)(BdrvChild *child, AioContext *ctx,
+ GSList **ignore, Error **errp);
+ void (*set_aio_ctx)(BdrvChild *child, AioContext *ctx, GSList **ignore);
+
+ AioContext *(*get_parent_aio_context)(BdrvChild *child);
+
+ /*
+ * I/O API functions. These functions are thread-safe.
+ *
+ * See include/block/block-io.h for more information about
+ * the I/O API.
+ */
+
+ void (*resize)(BdrvChild *child);
+
/*
* If this pair of functions is implemented, the parent doesn't issue new
* requests after returning from .drained_begin() until .drained_end() is
@@ -863,31 +901,6 @@ struct BdrvChildClass {
* activity on the child has stopped.
*/
bool (*drained_poll)(BdrvChild *child);
-
- /*
- * Notifies the parent that the child has been activated/inactivated (e.g.
- * when migration is completing) and it can start/stop requesting
- * permissions and doing I/O on it.
- */
- void (*activate)(BdrvChild *child, Error **errp);
- int (*inactivate)(BdrvChild *child);
-
- void (*attach)(BdrvChild *child);
- void (*detach)(BdrvChild *child);
-
- /*
- * Notifies the parent that the filename of its child has changed (e.g.
- * because the direct child was removed from the backing chain), so that it
- * can update its reference.
- */
- int (*update_filename)(BdrvChild *child, BlockDriverState *new_base,
- const char *filename, Error **errp);
-
- bool (*can_set_aio_ctx)(BdrvChild *child, AioContext *ctx,
- GSList **ignore, Error **errp);
- void (*set_aio_ctx)(BdrvChild *child, AioContext *ctx, GSList **ignore);
-
- AioContext *(*get_parent_aio_context)(BdrvChild *child);
};
extern const BdrvChildClass child_of_bds;
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 24/31] block_int-common.h: assertions in the callers of BdrvChildClass function pointers
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (22 preceding siblings ...)
2021-11-24 6:44 ` [PATCH v5 23/31] block_int-common.h: split function pointers in BdrvChildClass Emanuele Giuseppe Esposito
@ 2021-11-24 6:44 ` Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 25/31] block-backend-common.h: split function pointers in BlockDevOps Emanuele Giuseppe Esposito
` (7 subsequent siblings)
31 siblings, 0 replies; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:44 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
block.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/block.c b/block.c
index 180884b8c0..a0309f827d 100644
--- a/block.c
+++ b/block.c
@@ -1491,6 +1491,7 @@ const BdrvChildClass child_of_bds = {
AioContext *bdrv_child_get_parent_aio_context(BdrvChild *c)
{
+ assert(qemu_in_main_thread());
return c->klass->get_parent_aio_context(c);
}
@@ -2120,6 +2121,7 @@ bool bdrv_is_writable(BlockDriverState *bs)
static char *bdrv_child_user_desc(BdrvChild *c)
{
+ assert(qemu_in_main_thread());
return c->klass->get_parent_desc(c);
}
@@ -2832,6 +2834,7 @@ static void bdrv_replace_child_noperm(BdrvChild **childp,
assert(!child->frozen);
assert(old_bs != new_bs);
+ assert(qemu_in_main_thread());
if (old_bs && new_bs) {
assert(bdrv_get_aio_context(old_bs) == bdrv_get_aio_context(new_bs));
@@ -2928,6 +2931,7 @@ static void bdrv_attach_child_common_abort(void *opaque)
BdrvChild *child = *s->child;
BlockDriverState *bs = child->bs;
+ assert(qemu_in_main_thread());
/*
* Pass free_empty_child=false, because we still need the child
* for the AioContext operations on the parent below; those
@@ -3296,6 +3300,7 @@ void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child)
static void bdrv_parent_cb_change_media(BlockDriverState *bs, bool load)
{
BdrvChild *c;
+ assert(qemu_in_main_thread());
QLIST_FOREACH(c, &bs->parents, next_parent) {
if (c->klass->change_media) {
c->klass->change_media(c, load);
@@ -3792,6 +3797,7 @@ static BlockDriverState *bdrv_open_inherit(const char *filename,
assert(!child_class || !flags);
assert(!child_class == !parent);
+ assert(qemu_in_main_thread());
if (reference) {
bool options_non_empty = options ? qdict_size(options) : false;
@@ -4178,6 +4184,7 @@ static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue,
* important to avoid graph changes between the recursive queuing here and
* bdrv_reopen_multiple(). */
assert(bs->quiesce_counter > 0);
+ assert(qemu_in_main_thread());
if (bs_queue == NULL) {
bs_queue = g_new0(BlockReopenQueue, 1);
@@ -7271,6 +7278,7 @@ void bdrv_set_aio_context_ignore(BlockDriverState *bs,
BdrvChild *child, *parent;
g_assert(qemu_get_current_aio_context() == qemu_get_aio_context());
+ assert(qemu_in_main_thread());
if (old_context == new_context) {
return;
@@ -7343,6 +7351,7 @@ void bdrv_set_aio_context_ignore(BlockDriverState *bs,
static bool bdrv_parent_can_set_aio_context(BdrvChild *c, AioContext *ctx,
GSList **ignore, Error **errp)
{
+ assert(qemu_in_main_thread());
if (g_slist_find(*ignore, c)) {
return true;
}
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 25/31] block-backend-common.h: split function pointers in BlockDevOps
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (23 preceding siblings ...)
2021-11-24 6:44 ` [PATCH v5 24/31] block_int-common.h: assertions in the callers of BdrvChildClass function pointers Emanuele Giuseppe Esposito
@ 2021-11-24 6:44 ` Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 26/31] job.h: split function pointers in JobDriver Emanuele Giuseppe Esposito
` (6 subsequent siblings)
31 siblings, 0 replies; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:44 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Philippe Mathieu-Daudé,
Eric Blake
Assertions in the callers of the function pointrs are already
added by previous patches.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
include/sysemu/block-backend-common.h | 28 ++++++++++++++++++++++-----
1 file changed, 23 insertions(+), 5 deletions(-)
diff --git a/include/sysemu/block-backend-common.h b/include/sysemu/block-backend-common.h
index 6963bbf45a..ae630c624c 100644
--- a/include/sysemu/block-backend-common.h
+++ b/include/sysemu/block-backend-common.h
@@ -27,6 +27,14 @@
/* Callbacks for block device models */
typedef struct BlockDevOps {
+
+ /*
+ * Global state (GS) API. These functions run under the BQL lock.
+ *
+ * See include/block/block-global-state.h for more information about
+ * the GS API.
+ */
+
/*
* Runs when virtual media changed (monitor commands eject, change)
* Argument load is true on load and false on eject.
@@ -44,16 +52,26 @@ typedef struct BlockDevOps {
* true, even if they do not support eject requests.
*/
void (*eject_request_cb)(void *opaque, bool force);
- /*
- * Is the virtual tray open?
- * Device models implement this only when the device has a tray.
- */
- bool (*is_tray_open)(void *opaque);
+
/*
* Is the virtual medium locked into the device?
* Device models implement this only when device has such a lock.
*/
bool (*is_medium_locked)(void *opaque);
+
+ /*
+ * I/O API functions. These functions are thread-safe.
+ *
+ * See include/block/block-io.h for more information about
+ * the I/O API.
+ */
+
+ /*
+ * Is the virtual tray open?
+ * Device models implement this only when the device has a tray.
+ */
+ bool (*is_tray_open)(void *opaque);
+
/*
* Runs when the size changed (e.g. monitor command block_resize)
*/
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 26/31] job.h: split function pointers in JobDriver
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (24 preceding siblings ...)
2021-11-24 6:44 ` [PATCH v5 25/31] block-backend-common.h: split function pointers in BlockDevOps Emanuele Giuseppe Esposito
@ 2021-11-24 6:44 ` Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 27/31] job.h: assertions in the callers of JobDriver funcion pointers Emanuele Giuseppe Esposito
` (5 subsequent siblings)
31 siblings, 0 replies; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:44 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
The job API will be handled separately in another serie.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
include/qemu/job.h | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/include/qemu/job.h b/include/qemu/job.h
index 6e67b6977f..4ea7a4a0cd 100644
--- a/include/qemu/job.h
+++ b/include/qemu/job.h
@@ -169,6 +169,12 @@ typedef struct Job {
* Callbacks and other information about a Job driver.
*/
struct JobDriver {
+
+ /*
+ * These fields are initialized when this object is created,
+ * and are never changed afterwards
+ */
+
/** Derived Job struct size */
size_t instance_size;
@@ -184,9 +190,18 @@ struct JobDriver {
* aborted. If it returns zero, the job moves into the WAITING state. If it
* is the last job to complete in its transaction, all jobs in the
* transaction move from WAITING to PENDING.
+ *
+ * This callback must be run in the job's context.
*/
int coroutine_fn (*run)(Job *job, Error **errp);
+ /*
+ * Functions run without regard to the BQL that may run in any
+ * arbitrary thread. These functions do not need to be thread-safe
+ * because the caller ensures that they are invoked from one
+ * thread at time.
+ */
+
/**
* If the callback is not NULL, it will be invoked when the job transitions
* into the paused state. Paused jobs must not perform any asynchronous
@@ -201,6 +216,13 @@ struct JobDriver {
*/
void coroutine_fn (*resume)(Job *job);
+ /*
+ * Global state (GS) API. These functions run under the BQL lock.
+ *
+ * See include/block/block-global-state.h for more information about
+ * the GS API.
+ */
+
/**
* Called when the job is resumed by the user (i.e. user_paused becomes
* false). .user_resume is called before .resume.
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 27/31] job.h: assertions in the callers of JobDriver funcion pointers
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (25 preceding siblings ...)
2021-11-24 6:44 ` [PATCH v5 26/31] job.h: split function pointers in JobDriver Emanuele Giuseppe Esposito
@ 2021-11-24 6:44 ` Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 28/31] block.c: assert BQL lock held in bdrv_co_invalidate_cache Emanuele Giuseppe Esposito
` (4 subsequent siblings)
31 siblings, 0 replies; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:44 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
Also assert that job->run() callback is called in the job aiocontext.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
job.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/job.c b/job.c
index dbfa67bb0a..bb57ec6887 100644
--- a/job.c
+++ b/job.c
@@ -380,6 +380,8 @@ void job_ref(Job *job)
void job_unref(Job *job)
{
+ assert(qemu_in_main_thread());
+
if (--job->refcnt == 0) {
assert(job->status == JOB_STATUS_NULL);
assert(!timer_pending(&job->sleep_timer));
@@ -601,6 +603,7 @@ bool job_user_paused(Job *job)
void job_user_resume(Job *job, Error **errp)
{
assert(job);
+ assert(qemu_in_main_thread());
if (!job->user_paused || job->pause_count <= 0) {
error_setg(errp, "Can't resume a job that was not paused");
return;
@@ -671,6 +674,7 @@ static void job_update_rc(Job *job)
static void job_commit(Job *job)
{
assert(!job->ret);
+ assert(qemu_in_main_thread());
if (job->driver->commit) {
job->driver->commit(job);
}
@@ -679,6 +683,7 @@ static void job_commit(Job *job)
static void job_abort(Job *job)
{
assert(job->ret);
+ assert(qemu_in_main_thread());
if (job->driver->abort) {
job->driver->abort(job);
}
@@ -686,6 +691,7 @@ static void job_abort(Job *job)
static void job_clean(Job *job)
{
+ assert(qemu_in_main_thread());
if (job->driver->clean) {
job->driver->clean(job);
}
@@ -725,6 +731,7 @@ static int job_finalize_single(Job *job)
static void job_cancel_async(Job *job, bool force)
{
+ assert(qemu_in_main_thread());
if (job->driver->cancel) {
force = job->driver->cancel(job, force);
} else {
@@ -824,6 +831,7 @@ static void job_completed_txn_abort(Job *job)
static int job_prepare(Job *job)
{
+ assert(qemu_in_main_thread());
if (job->ret == 0 && job->driver->prepare) {
job->ret = job->driver->prepare(job);
job_update_rc(job);
@@ -950,6 +958,7 @@ static void coroutine_fn job_co_entry(void *opaque)
{
Job *job = opaque;
+ assert(job->aio_context == qemu_get_current_aio_context());
assert(job && job->driver && job->driver->run);
job_pause_point(job);
job->ret = job->driver->run(job, &job->err);
@@ -1053,6 +1062,7 @@ void job_complete(Job *job, Error **errp)
{
/* Should not be reachable via external interface for internal jobs */
assert(job->id);
+ assert(qemu_in_main_thread());
if (job_apply_verb(job, JOB_VERB_COMPLETE, errp)) {
return;
}
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 28/31] block.c: assert BQL lock held in bdrv_co_invalidate_cache
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (26 preceding siblings ...)
2021-11-24 6:44 ` [PATCH v5 27/31] job.h: assertions in the callers of JobDriver funcion pointers Emanuele Giuseppe Esposito
@ 2021-11-24 6:44 ` Emanuele Giuseppe Esposito
2021-12-17 11:04 ` Hanna Reitz
2021-11-24 6:44 ` [PATCH v5 29/31] jobs: introduce pre_run function in JobDriver Emanuele Giuseppe Esposito
` (3 subsequent siblings)
31 siblings, 1 reply; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:44 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
bdrv_co_invalidate_cache is special: it is an I/O function,
but uses the block layer permission API, which is GS.
Because of this, we can assert that either the function is
being called with BQL held, and thus can use the permission API,
or make sure that the permission API is not used, by ensuring that
bs (and parents) .open_flags does not contain BDRV_O_INACTIVE.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
block.c | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)
diff --git a/block.c b/block.c
index a0309f827d..805974676b 100644
--- a/block.c
+++ b/block.c
@@ -6574,6 +6574,26 @@ void bdrv_init_with_whitelist(void)
bdrv_init();
}
+static bool bdrv_is_active(BlockDriverState *bs)
+{
+ BdrvChild *parent;
+
+ if (bs->open_flags & BDRV_O_INACTIVE) {
+ return false;
+ }
+
+ QLIST_FOREACH(parent, &bs->parents, next_parent) {
+ if (parent->klass->parent_is_bds) {
+ BlockDriverState *parent_bs = parent->opaque;
+ if (!bdrv_is_active(parent_bs)) {
+ return false;
+ }
+ }
+ }
+
+ return true;
+}
+
int coroutine_fn bdrv_co_invalidate_cache(BlockDriverState *bs, Error **errp)
{
BdrvChild *child, *parent;
@@ -6585,6 +6605,12 @@ int coroutine_fn bdrv_co_invalidate_cache(BlockDriverState *bs, Error **errp)
return -ENOMEDIUM;
}
+ /*
+ * No need to muck with permissions if bs is active.
+ * TODO: should activation be a separate function?
+ */
+ assert(qemu_in_main_thread() || bdrv_is_active(bs));
+
QLIST_FOREACH(child, &bs->children, next) {
bdrv_co_invalidate_cache(child->bs, &local_err);
if (local_err) {
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 29/31] jobs: introduce pre_run function in JobDriver
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (27 preceding siblings ...)
2021-11-24 6:44 ` [PATCH v5 28/31] block.c: assert BQL lock held in bdrv_co_invalidate_cache Emanuele Giuseppe Esposito
@ 2021-11-24 6:44 ` Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 30/31] crypto: delegate permission functions to JobDriver .pre_run Emanuele Giuseppe Esposito
` (2 subsequent siblings)
31 siblings, 0 replies; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:44 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
.pre_run takes care of doing some initial job setup just before
the job is run inside the coroutine. Doing so can be useful
to invoke GS functions that require the BQL held.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
include/qemu/job.h | 9 +++++++++
job.c | 13 +++++++++++++
2 files changed, 22 insertions(+)
diff --git a/include/qemu/job.h b/include/qemu/job.h
index 4ea7a4a0cd..915ceff425 100644
--- a/include/qemu/job.h
+++ b/include/qemu/job.h
@@ -223,6 +223,15 @@ struct JobDriver {
* the GS API.
*/
+ /**
+ * Called in the Main Loop context, before the job coroutine
+ * is started in the job aiocontext. Useful to perform operations
+ * that needs to be done under BQL (like permissions setup).
+ * On success, it returns 0. Otherwise the job failed to initialize
+ * and won't start.
+ */
+ int (*pre_run)(Job *job, Error **errp);
+
/**
* Called when the job is resumed by the user (i.e. user_paused becomes
* false). .user_resume is called before .resume.
diff --git a/job.c b/job.c
index bb57ec6887..e048037099 100644
--- a/job.c
+++ b/job.c
@@ -967,11 +967,24 @@ static void coroutine_fn job_co_entry(void *opaque)
aio_bh_schedule_oneshot(qemu_get_aio_context(), job_exit, job);
}
+static int job_pre_run(Job *job)
+{
+ assert(qemu_in_main_thread());
+ if (job->driver->pre_run) {
+ return job->driver->pre_run(job, &job->err);
+ }
+
+ return 0;
+}
+
void job_start(Job *job)
{
assert(job && !job_started(job) && job->paused &&
job->driver && job->driver->run);
job->co = qemu_coroutine_create(job_co_entry, job);
+ if (job_pre_run(job)) {
+ return;
+ }
job->pause_count--;
job->busy = true;
job->paused = false;
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 30/31] crypto: delegate permission functions to JobDriver .pre_run
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (28 preceding siblings ...)
2021-11-24 6:44 ` [PATCH v5 29/31] jobs: introduce pre_run function in JobDriver Emanuele Giuseppe Esposito
@ 2021-11-24 6:44 ` Emanuele Giuseppe Esposito
2021-12-17 12:29 ` Hanna Reitz
2021-11-24 6:44 ` [PATCH v5 31/31] block.c: assertions to the block layer permissions API Emanuele Giuseppe Esposito
2021-11-29 13:32 ` [PATCH v5 00/31] block layer: split block APIs in global state and I/O Stefan Hajnoczi
31 siblings, 1 reply; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:44 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
block_crypto_amend_options_generic_luks uses the block layer
permission API, therefore it should be called with the BQL held.
However, the same function is being called ib two BlockDriver
callbacks: bdrv_amend_options (under BQL) and bdrv_co_amend (I/O).
The latter is I/O because it is invoked by block/amend.c's
blockdev_amend_run(), a .run callback of the amend JobDriver
Therefore we want to 1) change block_crypto_amend_options_generic_luks
to use the permission API only when the BQL is held, and
2) use the .pre_run JobDriver callback to check for
permissions before switching to the job aiocontext. This has also
the benefit of applying the same permission operation to all
amend implementations, not only luks.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
block/amend.c | 20 ++++++++++++++++++++
block/crypto.c | 18 ++++++++++++------
2 files changed, 32 insertions(+), 6 deletions(-)
diff --git a/block/amend.c b/block/amend.c
index 392df9ef83..fba6add51a 100644
--- a/block/amend.c
+++ b/block/amend.c
@@ -53,10 +53,30 @@ static int coroutine_fn blockdev_amend_run(Job *job, Error **errp)
return ret;
}
+static int blockdev_amend_refresh_perms(Job *job, Error **errp)
+{
+ BlockdevAmendJob *s = container_of(job, BlockdevAmendJob, common);
+
+ return bdrv_child_refresh_perms(s->bs, s->bs->file, errp);
+}
+
+static int blockdev_amend_pre_run(Job *job, Error **errp)
+{
+ return blockdev_amend_refresh_perms(job, errp);
+}
+
+static void blockdev_amend_clean(Job *job)
+{
+ Error *errp;
+ blockdev_amend_refresh_perms(job, &errp);
+}
+
static const JobDriver blockdev_amend_job_driver = {
.instance_size = sizeof(BlockdevAmendJob),
.job_type = JOB_TYPE_AMEND,
.run = blockdev_amend_run,
+ .pre_run = blockdev_amend_pre_run,
+ .clean = blockdev_amend_clean,
};
void qmp_x_blockdev_amend(const char *job_id,
diff --git a/block/crypto.c b/block/crypto.c
index c8ba4681e2..82f154516c 100644
--- a/block/crypto.c
+++ b/block/crypto.c
@@ -780,6 +780,7 @@ block_crypto_get_specific_info_luks(BlockDriverState *bs, Error **errp)
static int
block_crypto_amend_options_generic_luks(BlockDriverState *bs,
QCryptoBlockAmendOptions *amend_options,
+ bool under_bql,
bool force,
Error **errp)
{
@@ -791,9 +792,12 @@ block_crypto_amend_options_generic_luks(BlockDriverState *bs,
/* apply for exclusive read/write permissions to the underlying file*/
crypto->updating_keys = true;
- ret = bdrv_child_refresh_perms(bs, bs->file, errp);
- if (ret) {
- goto cleanup;
+
+ if (under_bql) {
+ ret = bdrv_child_refresh_perms(bs, bs->file, errp);
+ if (ret) {
+ goto cleanup;
+ }
}
ret = qcrypto_block_amend_options(crypto->block,
@@ -806,7 +810,9 @@ block_crypto_amend_options_generic_luks(BlockDriverState *bs,
cleanup:
/* release exclusive read/write permissions to the underlying file*/
crypto->updating_keys = false;
- bdrv_child_refresh_perms(bs, bs->file, errp);
+ if (under_bql) {
+ bdrv_child_refresh_perms(bs, bs->file, errp);
+ }
return ret;
}
@@ -834,7 +840,7 @@ block_crypto_amend_options_luks(BlockDriverState *bs,
goto cleanup;
}
ret = block_crypto_amend_options_generic_luks(bs, amend_options,
- force, errp);
+ true, force, errp);
cleanup:
qapi_free_QCryptoBlockAmendOptions(amend_options);
return ret;
@@ -853,7 +859,7 @@ coroutine_fn block_crypto_co_amend_luks(BlockDriverState *bs,
.u.luks = *qapi_BlockdevAmendOptionsLUKS_base(&opts->u.luks),
};
return block_crypto_amend_options_generic_luks(bs, &amend_opts,
- force, errp);
+ false, force, errp);
}
static void
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* [PATCH v5 31/31] block.c: assertions to the block layer permissions API
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (29 preceding siblings ...)
2021-11-24 6:44 ` [PATCH v5 30/31] crypto: delegate permission functions to JobDriver .pre_run Emanuele Giuseppe Esposito
@ 2021-11-24 6:44 ` Emanuele Giuseppe Esposito
2021-11-29 13:32 ` [PATCH v5 00/31] block layer: split block APIs in global state and I/O Stefan Hajnoczi
31 siblings, 0 replies; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-24 6:44 UTC (permalink / raw)
To: qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Emanuele Giuseppe Esposito, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
Now that we "covered" the three main cases where the
permission API was being used under BQL (fuse,
amend and invalidate_cache), we can safely assert for
the permission functions implemented in block.c
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
block.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/block.c b/block.c
index 805974676b..6056ec4bc5 100644
--- a/block.c
+++ b/block.c
@@ -2138,6 +2138,7 @@ static bool bdrv_a_allow_b(BdrvChild *a, BdrvChild *b, Error **errp)
assert(a->bs);
assert(a->bs == b->bs);
+ assert(qemu_in_main_thread());
if ((b->perm & a->shared_perm) == b->perm) {
return true;
@@ -2161,6 +2162,7 @@ static bool bdrv_a_allow_b(BdrvChild *a, BdrvChild *b, Error **errp)
static bool bdrv_parent_perms_conflict(BlockDriverState *bs, Error **errp)
{
BdrvChild *a, *b;
+ assert(qemu_in_main_thread());
/*
* During the loop we'll look at each pair twice. That's correct because
@@ -2245,6 +2247,8 @@ static void bdrv_child_set_perm_abort(void *opaque)
{
BdrvChildSetPermState *s = opaque;
+ assert(qemu_in_main_thread());
+
s->child->perm = s->old_perm;
s->child->shared_perm = s->old_shared_perm;
}
@@ -2258,6 +2262,7 @@ static void bdrv_child_set_perm(BdrvChild *c, uint64_t perm,
uint64_t shared, Transaction *tran)
{
BdrvChildSetPermState *s = g_new(BdrvChildSetPermState, 1);
+ assert(qemu_in_main_thread());
*s = (BdrvChildSetPermState) {
.child = c,
@@ -2442,6 +2447,7 @@ static int bdrv_node_refresh_perm(BlockDriverState *bs, BlockReopenQueue *q,
BdrvChild *c;
int ret;
uint64_t cumulative_perms, cumulative_shared_perms;
+ assert(qemu_in_main_thread());
bdrv_get_cumulative_perm(bs, &cumulative_perms, &cumulative_shared_perms);
@@ -2510,6 +2516,7 @@ static int bdrv_list_refresh_perms(GSList *list, BlockReopenQueue *q,
{
int ret;
BlockDriverState *bs;
+ assert(qemu_in_main_thread());
for ( ; list; list = list->next) {
bs = list->data;
@@ -2582,6 +2589,7 @@ static int bdrv_refresh_perms(BlockDriverState *bs, Error **errp)
int ret;
Transaction *tran = tran_new();
g_autoptr(GSList) list = bdrv_topological_dfs(NULL, NULL, bs);
+ assert(qemu_in_main_thread());
ret = bdrv_list_refresh_perms(list, NULL, tran, errp);
tran_finalize(tran, ret);
@@ -2648,6 +2656,7 @@ static void bdrv_filter_default_perms(BlockDriverState *bs, BdrvChild *c,
uint64_t perm, uint64_t shared,
uint64_t *nperm, uint64_t *nshared)
{
+ assert(qemu_in_main_thread());
*nperm = perm & DEFAULT_PERM_PASSTHROUGH;
*nshared = (shared & DEFAULT_PERM_PASSTHROUGH) | DEFAULT_PERM_UNCHANGED;
}
@@ -2659,6 +2668,7 @@ static void bdrv_default_perms_for_cow(BlockDriverState *bs, BdrvChild *c,
uint64_t *nperm, uint64_t *nshared)
{
assert(role & BDRV_CHILD_COW);
+ assert(qemu_in_main_thread());
/*
* We want consistent read from backing files if the parent needs it.
@@ -2696,6 +2706,7 @@ static void bdrv_default_perms_for_storage(BlockDriverState *bs, BdrvChild *c,
{
int flags;
+ assert(qemu_in_main_thread());
assert(role & (BDRV_CHILD_METADATA | BDRV_CHILD_DATA));
flags = bdrv_reopen_get_flags(reopen_queue, bs);
@@ -6094,6 +6105,7 @@ static void xdbg_graph_add_edge(XDbgBlockGraphConstructor *gr, void *parent,
{
BlockPermission qapi_perm;
XDbgBlockGraphEdge *edge;
+ assert(qemu_in_main_thread());
edge = g_new0(XDbgBlockGraphEdge, 1);
--
2.27.0
^ permalink raw reply related [flat|nested] 66+ messages in thread
* Re: [PATCH v5 00/31] block layer: split block APIs in global state and I/O
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
` (30 preceding siblings ...)
2021-11-24 6:44 ` [PATCH v5 31/31] block.c: assertions to the block layer permissions API Emanuele Giuseppe Esposito
@ 2021-11-29 13:32 ` Stefan Hajnoczi
2021-11-30 8:39 ` Emanuele Giuseppe Esposito
31 siblings, 1 reply; 66+ messages in thread
From: Stefan Hajnoczi @ 2021-11-29 13:32 UTC (permalink / raw)
To: Emanuele Giuseppe Esposito
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, qemu-block, Juan Quintela, qemu-devel,
John Snow, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Paolo Bonzini, Eric Blake
[-- Attachment #1: Type: text/plain, Size: 2147 bytes --]
On Wed, Nov 24, 2021 at 01:43:47AM -0500, Emanuele Giuseppe Esposito wrote:
> v5 -> v6:
> * In short, apply all Hanna's comments. More in details,
> the following functions in the following headers have been moved:
> block-backend:
> blk_replace_bs (to gs)
> blk_nb_sectors (to io)
> blk_name (to io)
> blk_set_perm (to io)
> blk_get_perm (to io)
> blk_drain (to io)
> blk_abort_aio_request (to io)
> blk_make_empty (to gs)
> blk_invalidate_cache (was in io, but had GS assertion)
> blk_aio_cancel (to gs)
> block:
> bdrv_replace_child_bs (to gs)
> bdrv_get_device_name (to io)
> bdrv_get_device_or_node_name (to io)
> bdrv_drained_end_no_poll (to io)
> bdrv_block_status (was in io, but had GS assertion)
> bdrv_drain (to io)
> bdrv_co_drain (to io)
> bdrv_make_zero (was in GS, but did not have the assertion)
> bdrv_save_vmstate (to io)
> bdrv_load_vmstate (to io)
> bdrv_aio_cancel_async (to io)
> block_int:
> bdrv_get_parent_name (to io)
> bdrv_apply_subtree_drain (to io)
> bdrv_unapply_subtree_drain (to io)
> bdrv_co_copy_range_from (was in io, but had GS assertion)
> bdrv_co_copy_range_to (was in io, but had GS assertion)
> ->bdrv_save_vmstate (to io)
> ->bdrv_load_vmstate (to io)
>
> coding style (assertion after definitions):
> bdrv_save_vmstate
> bdrv_load_vmstate
> block_job_next
> block_job_get
>
> new patches:
> block.c: modify .attach and .detach callbacks of child_of_bds
> introduce pre_run as JobDriver callback to handle
> bdrv_co_amend usage of permission function
> leave blk_set/get_perm as a TODO in fuse.c
> make sure bdrv_co_invalidate_cache does not use permissions
> if BQL is not held
>
> minor changes:
> put back TODO for include block/block.h in block-backend-common.h
> rebase on kwolf/block branch
> modify where are used assert_bdrv_graph_writable, due to rebase
These changes sound fine to me. Hanna or Kevin can merge the series when
they are happy.
Stefan
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 00/31] block layer: split block APIs in global state and I/O
2021-11-29 13:32 ` [PATCH v5 00/31] block layer: split block APIs in global state and I/O Stefan Hajnoczi
@ 2021-11-30 8:39 ` Emanuele Giuseppe Esposito
0 siblings, 0 replies; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-11-30 8:39 UTC (permalink / raw)
To: Stefan Hajnoczi
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, qemu-block, Juan Quintela, qemu-devel,
John Snow, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Paolo Bonzini, Eric Blake
On 29/11/2021 14:32, Stefan Hajnoczi wrote:
> On Wed, Nov 24, 2021 at 01:43:47AM -0500, Emanuele Giuseppe Esposito wrote:
>> v5 -> v6:
>> * In short, apply all Hanna's comments. More in details,
>> the following functions in the following headers have been moved:
>> block-backend:
>> blk_replace_bs (to gs)
>> blk_nb_sectors (to io)
>> blk_name (to io)
>> blk_set_perm (to io)
>> blk_get_perm (to io)
>> blk_drain (to io)
>> blk_abort_aio_request (to io)
>> blk_make_empty (to gs)
>> blk_invalidate_cache (was in io, but had GS assertion)
>> blk_aio_cancel (to gs)
>> block:
>> bdrv_replace_child_bs (to gs)
>> bdrv_get_device_name (to io)
>> bdrv_get_device_or_node_name (to io)
>> bdrv_drained_end_no_poll (to io)
>> bdrv_block_status (was in io, but had GS assertion)
>> bdrv_drain (to io)
>> bdrv_co_drain (to io)
>> bdrv_make_zero (was in GS, but did not have the assertion)
>> bdrv_save_vmstate (to io)
>> bdrv_load_vmstate (to io)
>> bdrv_aio_cancel_async (to io)
>> block_int:
>> bdrv_get_parent_name (to io)
>> bdrv_apply_subtree_drain (to io)
>> bdrv_unapply_subtree_drain (to io)
>> bdrv_co_copy_range_from (was in io, but had GS assertion)
>> bdrv_co_copy_range_to (was in io, but had GS assertion)
>> ->bdrv_save_vmstate (to io)
>> ->bdrv_load_vmstate (to io)
>>
>> coding style (assertion after definitions):
>> bdrv_save_vmstate
>> bdrv_load_vmstate
>> block_job_next
>> block_job_get
>>
>> new patches:
>> block.c: modify .attach and .detach callbacks of child_of_bds
>> introduce pre_run as JobDriver callback to handle
>> bdrv_co_amend usage of permission function
>> leave blk_set/get_perm as a TODO in fuse.c
>> make sure bdrv_co_invalidate_cache does not use permissions
>> if BQL is not held
>>
>> minor changes:
>> put back TODO for include block/block.h in block-backend-common.h
>> rebase on kwolf/block branch
>> modify where are used assert_bdrv_graph_writable, due to rebase
>
> These changes sound fine to me. Hanna or Kevin can merge the series when
> they are happy.
>
Just a tiny nitpick, I would just not merge patch 10: "block.c: modify
.attach and .detach callbacks of child_of_bds". It is not wrong and
should produce no side effect, but does not do what it was intended for
(ie using the drain to protect the bs's list of children). I will work
on that in a future serie. Apologies.
Thank you,
Emanuele
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 04/31] include/sysemu/block-backend: split header into I/O and global state (GS) API
2021-11-24 6:43 ` [PATCH v5 04/31] include/sysemu/block-backend: split header into I/O and global state (GS) API Emanuele Giuseppe Esposito
@ 2021-12-10 14:21 ` Hanna Reitz
0 siblings, 0 replies; 66+ messages in thread
From: Hanna Reitz @ 2021-12-10 14:21 UTC (permalink / raw)
To: Emanuele Giuseppe Esposito, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 24.11.21 07:43, Emanuele Giuseppe Esposito wrote:
> Similarly to the previous patches, split block-backend.h
> in block-backend-io.h and block-backend-global-state.h
>
> In addition, remove "block/block.h" include as it seems
> it is not necessary anymore, together with "qemu/iov.h"
>
> block-backend-common.h contains the structures shared between
> the two headers, and the functions that can't be categorized as
> I/O or global state.
>
> Assertions are added in the next patch.
>
> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
> ---
> include/sysemu/block-backend-common.h | 84 ++++++
> include/sysemu/block-backend-global-state.h | 121 +++++++++
> include/sysemu/block-backend-io.h | 139 ++++++++++
> include/sysemu/block-backend.h | 269 +-------------------
> block/block-backend.c | 9 +-
> 5 files changed, 353 insertions(+), 269 deletions(-)
> create mode 100644 include/sysemu/block-backend-common.h
> create mode 100644 include/sysemu/block-backend-global-state.h
> create mode 100644 include/sysemu/block-backend-io.h
[...]
> diff --git a/include/sysemu/block-backend-global-state.h b/include/sysemu/block-backend-global-state.h
> new file mode 100644
> index 0000000000..77009bf7a2
> --- /dev/null
> +++ b/include/sysemu/block-backend-global-state.h
[...]
> +int blk_ioctl(BlockBackend *blk, unsigned long int req, void *buf);
I don’t quite follow what makes blk_ioctl() a GS function. (It’s
possible that I forgot something about this from v4, though, and can’t
find it anymore...)
I suppose it can be said that in the context of the block layer, ioctl
functions are generally used outside of I/O threads as something that
kind of affects the global data state, but... bdrv_co_ioctl() is in
block-io.h, and internally we definitely do use ioctl in I/O threads
(various uses in file-posix.c, e.g. to zero out areas). I also don’t
understand why blk_ioctl() is GS, and blk_aio_ioctl() is I/O.
And if you have a virtio-scsi device in an iothread, and then create a
scsi-generic device on it, will bdrv_co_ioctl() not run in the I/O
thread still...? Hm, testing (on patch 6), it appears that not – I
think that’s because it mostly uses blk_aio_ioctl(), apart from
*_realize() and scsi_SG_IO_FROM_DEV() (whatever that is; and this makes
me a bit cautious, too). Still, I’m not quite sure how it’s more global
state than e.g. writing zeroes or, well, blk_aio_ioctl().
However, testing brought some other problems to light:
$ ls /dev/sg?
/dev/sg0
$ sudo modprobe scsi_debug max_luns=1 num_tgts=1 add_host=1
$ ls /dev/sg?
/dev/sg0 /dev/sg1
$ ./qemu-system-x86_64 \
-object iothread,id=foo \
-device virtio-scsi,iothread=foo \
-blockdev host_device,filename=/dev/sg1,node-name=bar \
-device scsi-generic,drive=bar
qemu-system-x86_64: ../block/block-backend.c:2038:
blk_set_guest_block_size: Assertion `qemu_in_main_thread()' failed.
[1] 121353 IOT instruction (core dumped) ./qemu-system-x86_64
-object iothread,id=foo -device virtio-scsi,iothread=foo
And:
$ ./qemu-system-x86_64 \
-object iothread,id=foo \
-device virtio-scsi,iothread=foo \
-blockdev null-co,read-zeroes=true,node-name=bar \
-device scsi-hd,drive=bar \
-cdrom ~/tmp/arch.iso \
-enable-kvm \
-m 1g
qemu-system-x86_64: ../block/block-backend.c:1918:
blk_enable_write_cache: Assertion `qemu_in_main_thread()' failed.
[1] 127203 IOT instruction (core dumped) ./qemu-system-x86_64
-object iothread,id=foo -device virtio-scsi,iothread=foo
If I boot from a CD under virtio-scsi (in an iothread), I also get an
error for blk_lock_medium(), and if I eject such a CD, for blk_eject()
and blk_get_attached_dev_id() (called from blk_eject()).
It appears like scsi_disk_emulate_command() is always run in the BB’s
AioContext, and so everything it (indirectly) calls cannot assume to be
in the main thread. As for blk_set_guest_block_size(), that one’s
called from scsi-generic’s scsi_read_complete().
Hanna
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 05/31] block-backend: special comments for blk_set/get_perm due to fuse
2021-11-24 6:43 ` [PATCH v5 05/31] block-backend: special comments for blk_set/get_perm due to fuse Emanuele Giuseppe Esposito
@ 2021-12-10 14:38 ` Hanna Reitz
2021-12-15 8:57 ` Emanuele Giuseppe Esposito
0 siblings, 1 reply; 66+ messages in thread
From: Hanna Reitz @ 2021-12-10 14:38 UTC (permalink / raw)
To: Emanuele Giuseppe Esposito, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 24.11.21 07:43, Emanuele Giuseppe Esposito wrote:
> Fuse logic can be classified as I/O, so there is no BQL held
> during its execution. And yet, it uses blk_{get/set}_perm
> functions, that are classified as BQL and clearly require
> the BQL lock. Since there is no easy solution for this,
> add a couple of TODOs and FIXME in the relevant sections of the
> code.
Well, the problem goes deeper, because we still consider them GS
functions. So it’s fine for the permission function
raw_handle_perm_lock() to call bdrv_get_flags(), which is a GS function,
and then you still get:
qemu-storage-daemon: ../block.c:6195: bdrv_get_flags: Assertion
`qemu_in_main_thread()' failed.
It looks like in this case making bdrv_get_flags() not a GS function
would be feasible and might solve the problem, but I guess we should
instead think about adding something like
if (!exp->growable && !qemu_in_main_thread()) {
/* Changing permissions like below only works in the main thread */
return -EPERM;
}
to fuse_do_truncate().
Ideally, to make up for this, we should probably take the RESIZE
permission in fuse_export_create() for writable exports in iothreads.
> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
> ---
> block/block-backend.c | 10 ++++++++++
> block/export/fuse.c | 16 ++++++++++++++--
> 2 files changed, 24 insertions(+), 2 deletions(-)
>
> diff --git a/block/block-backend.c b/block/block-backend.c
> index 1f0bda578e..7a4b50a8f0 100644
> --- a/block/block-backend.c
> +++ b/block/block-backend.c
> @@ -888,6 +888,11 @@ int blk_set_perm(BlockBackend *blk, uint64_t perm, uint64_t shared_perm,
> Error **errp)
> {
> int ret;
> + /*
> + * FIXME: blk_{get/set}_perm should be always called under
> + * BQL, but it is not the case right now (see block/export/fuse.c)
> + */
> + /* assert(qemu_in_main_thread()); */
>
> if (blk->root && !blk->disable_perm) {
> ret = bdrv_child_try_set_perm(blk->root, perm, shared_perm, errp);
> @@ -904,6 +909,11 @@ int blk_set_perm(BlockBackend *blk, uint64_t perm, uint64_t shared_perm,
>
> void blk_get_perm(BlockBackend *blk, uint64_t *perm, uint64_t *shared_perm)
> {
> + /*
> + * FIXME: blk_{get/set}_perm should be always called under
> + * BQL, but it is not the case right now (see block/export/fuse.c)
> + */
> + /* assert(qemu_in_main_thread()); */
> *perm = blk->perm;
> *shared_perm = blk->shared_perm;
> }
> diff --git a/block/export/fuse.c b/block/export/fuse.c
> index 823c126d23..7ceb8d783b 100644
> --- a/block/export/fuse.c
> +++ b/block/export/fuse.c
> @@ -89,7 +89,10 @@ static int fuse_export_create(BlockExport *blk_exp,
> /* For growable exports, take the RESIZE permission */
> if (args->growable) {
> uint64_t blk_perm, blk_shared_perm;
> -
> + /*
> + * FIXME: blk_{get/set}_perm should not be here, as permissions
> + * should be modified only under BQL and here we are not!
> + */
I believe we are, BlockExportDriver.create() is called by blk_exp_add(),
which looks very much like it runs in the main thread (calling
bdrv_lookup_bs(), bdrv_try_set_aio_context(), blk_new(), and whatnot).
Hanna
> blk_get_perm(exp->common.blk, &blk_perm, &blk_shared_perm);
>
> ret = blk_set_perm(exp->common.blk, blk_perm | BLK_PERM_RESIZE,
> @@ -400,6 +403,11 @@ static int fuse_do_truncate(const FuseExport *exp, int64_t size,
>
> /* Growable exports have a permanent RESIZE permission */
> if (!exp->growable) {
> +
> + /*
> + * FIXME: blk_{get/set}_perm should not be here, as permissions
> + * should be modified only under BQL and here we are not!
> + */
> blk_get_perm(exp->common.blk, &blk_perm, &blk_shared_perm);
>
> ret = blk_set_perm(exp->common.blk, blk_perm | BLK_PERM_RESIZE,
> @@ -413,7 +421,11 @@ static int fuse_do_truncate(const FuseExport *exp, int64_t size,
> truncate_flags, NULL);
>
> if (!exp->growable) {
> - /* Must succeed, because we are only giving up the RESIZE permission */
> + /*
> + * Must succeed, because we are only giving up the RESIZE permission.
> + * FIXME: blk_{get/set}_perm should not be here, as permissions
> + * should be modified only under BQL and here we are not!
> + */
> blk_set_perm(exp->common.blk, blk_perm, blk_shared_perm, &error_abort);
> }
>
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 06/31] block/block-backend.c: assertions for block-backend
2021-11-24 6:43 ` [PATCH v5 06/31] block/block-backend.c: assertions for block-backend Emanuele Giuseppe Esposito
@ 2021-12-10 15:37 ` Hanna Reitz
0 siblings, 0 replies; 66+ messages in thread
From: Hanna Reitz @ 2021-12-10 15:37 UTC (permalink / raw)
To: Emanuele Giuseppe Esposito, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 24.11.21 07:43, Emanuele Giuseppe Esposito wrote:
> All the global state (GS) API functions will check that
> qemu_in_main_thread() returns true. If not, it means
> that the safety of BQL cannot be guaranteed, and
> they need to be moved to I/O.
>
> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
> ---
> block/block-backend.c | 83 ++++++++++++++++++++++++++++++++++++++++++
> softmmu/qdev-monitor.c | 2 +
> 2 files changed, 85 insertions(+)
So given my thoughts on patch 5, I believe that blk_set_perm() and
blk_get_perm() should get assertions here.
Hanna
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 09/31] block: introduce assert_bdrv_graph_writable
2021-11-24 6:43 ` [PATCH v5 09/31] block: introduce assert_bdrv_graph_writable Emanuele Giuseppe Esposito
@ 2021-12-10 17:43 ` Hanna Reitz
2021-12-14 19:48 ` Emanuele Giuseppe Esposito
0 siblings, 1 reply; 66+ messages in thread
From: Hanna Reitz @ 2021-12-10 17:43 UTC (permalink / raw)
To: Emanuele Giuseppe Esposito, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 24.11.21 07:43, Emanuele Giuseppe Esposito wrote:
> We want to be sure that the functions that write the child and
> parent list of a bs are under BQL and drain.
>
> BQL prevents from concurrent writings from the GS API, while
> drains protect from I/O.
>
> TODO: drains are missing in some functions using this assert.
> Therefore a proper assertion will fail. Because adding drains
> requires additional discussions, they will be added in future
> series.
>
> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
> ---
> include/block/block_int-global-state.h | 10 +++++++++-
> block.c | 4 ++++
> block/io.c | 11 +++++++++++
> 3 files changed, 24 insertions(+), 1 deletion(-)
>
> diff --git a/include/block/block_int-global-state.h b/include/block/block_int-global-state.h
> index a1b7d0579d..fa96e8b449 100644
> --- a/include/block/block_int-global-state.h
> +++ b/include/block/block_int-global-state.h
> @@ -312,4 +312,12 @@ void bdrv_remove_aio_context_notifier(BlockDriverState *bs,
> */
> void bdrv_drain_all_end_quiesce(BlockDriverState *bs);
>
> -#endif /* BLOCK_INT_GLOBAL_STATE*/
This looks like it should be squashed into patch 7, sorry I missed this
in v4...
(Rest of this patch looks good to me, for the record – and while I’m at
it, for patches I didn’t reply to so far, I planned to send an R-b
later. But then there’s things like patches 2/3 looking good to me, but
it turned out in my review for patch 4 that bdrv_lock_medium() is used
in an I/O path, so I can’t really send an R-b now anymore...)
Hanna
> +/**
> + * Make sure that the function is running under both drain and BQL.
> + * The latter protects from concurrent writings
> + * from the GS API, while the former prevents concurrent reads
> + * from I/O.
> + */
> +void assert_bdrv_graph_writable(BlockDriverState *bs);
> +
> +#endif /* BLOCK_INT_GLOBAL_STATE */
> diff --git a/block.c b/block.c
> index 198ec636ff..522a273140 100644
> --- a/block.c
> +++ b/block.c
> @@ -1416,6 +1416,7 @@ static void bdrv_child_cb_attach(BdrvChild *child)
> {
> BlockDriverState *bs = child->opaque;
>
> + assert_bdrv_graph_writable(bs);
> QLIST_INSERT_HEAD(&bs->children, child, next);
>
> if (child->role & BDRV_CHILD_COW) {
> @@ -1435,6 +1436,7 @@ static void bdrv_child_cb_detach(BdrvChild *child)
>
> bdrv_unapply_subtree_drain(child, bs);
>
> + assert_bdrv_graph_writable(bs);
> QLIST_REMOVE(child, next);
> }
>
> @@ -2818,6 +2820,7 @@ static void bdrv_replace_child_noperm(BdrvChild **childp,
> if (child->klass->detach) {
> child->klass->detach(child);
> }
> + assert_bdrv_graph_writable(old_bs);
> QLIST_REMOVE(child, next_parent);
> }
>
> @@ -2827,6 +2830,7 @@ static void bdrv_replace_child_noperm(BdrvChild **childp,
> }
>
> if (new_bs) {
> + assert_bdrv_graph_writable(new_bs);
> QLIST_INSERT_HEAD(&new_bs->parents, child, next_parent);
>
> /*
> diff --git a/block/io.c b/block/io.c
> index cb095deeec..3be08cad29 100644
> --- a/block/io.c
> +++ b/block/io.c
> @@ -734,6 +734,17 @@ void bdrv_drain_all(void)
> bdrv_drain_all_end();
> }
>
> +void assert_bdrv_graph_writable(BlockDriverState *bs)
> +{
> + /*
> + * TODO: this function is incomplete. Because the users of this
> + * assert lack the necessary drains, check only for BQL.
> + * Once the necessary drains are added,
> + * assert also for qatomic_read(&bs->quiesce_counter) > 0
> + */
> + assert(qemu_in_main_thread());
> +}
> +
> /**
> * Remove an active request from the tracked requests list
> *
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 09/31] block: introduce assert_bdrv_graph_writable
2021-12-10 17:43 ` Hanna Reitz
@ 2021-12-14 19:48 ` Emanuele Giuseppe Esposito
2021-12-16 14:01 ` Hanna Reitz
0 siblings, 1 reply; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-12-14 19:48 UTC (permalink / raw)
To: Hanna Reitz, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 10/12/2021 18:43, Hanna Reitz wrote:
> On 24.11.21 07:43, Emanuele Giuseppe Esposito wrote:
>> We want to be sure that the functions that write the child and
>> parent list of a bs are under BQL and drain.
>>
>> BQL prevents from concurrent writings from the GS API, while
>> drains protect from I/O.
>>
>> TODO: drains are missing in some functions using this assert.
>> Therefore a proper assertion will fail. Because adding drains
>> requires additional discussions, they will be added in future
>> series.
>>
>> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
>> ---
>> include/block/block_int-global-state.h | 10 +++++++++-
>> block.c | 4 ++++
>> block/io.c | 11 +++++++++++
>> 3 files changed, 24 insertions(+), 1 deletion(-)
>>
>> diff --git a/include/block/block_int-global-state.h
>> b/include/block/block_int-global-state.h
>> index a1b7d0579d..fa96e8b449 100644
>> --- a/include/block/block_int-global-state.h
>> +++ b/include/block/block_int-global-state.h
>> @@ -312,4 +312,12 @@ void
>> bdrv_remove_aio_context_notifier(BlockDriverState *bs,
>> */
>> void bdrv_drain_all_end_quiesce(BlockDriverState *bs);
>> -#endif /* BLOCK_INT_GLOBAL_STATE*/
>
> This looks like it should be squashed into patch 7, sorry I missed this
> in v4...
>
> (Rest of this patch looks good to me, for the record – and while I’m at
> it, for patches I didn’t reply to so far, I planned to send an R-b
> later. But then there’s things like patches 2/3 looking good to me, but
> it turned out in my review for patch 4 that bdrv_lock_medium() is used
> in an I/O path, so I can’t really send an R-b now anymore...)
>
Sorry I don't understand this, what should be squashed into patch 7? The
assertion? If so, why?
Thank you,
Emanuele
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 05/31] block-backend: special comments for blk_set/get_perm due to fuse
2021-12-10 14:38 ` Hanna Reitz
@ 2021-12-15 8:57 ` Emanuele Giuseppe Esposito
2021-12-15 10:13 ` Emanuele Giuseppe Esposito
0 siblings, 1 reply; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-12-15 8:57 UTC (permalink / raw)
To: Hanna Reitz, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 10/12/2021 15:38, Hanna Reitz wrote:
> On 24.11.21 07:43, Emanuele Giuseppe Esposito wrote:
>> Fuse logic can be classified as I/O, so there is no BQL held
>> during its execution. And yet, it uses blk_{get/set}_perm
>> functions, that are classified as BQL and clearly require
>> the BQL lock. Since there is no easy solution for this,
>> add a couple of TODOs and FIXME in the relevant sections of the
>> code.
>
> Well, the problem goes deeper, because we still consider them GS
> functions. So it’s fine for the permission function
> raw_handle_perm_lock() to call bdrv_get_flags(), which is a GS function,
> and then you still get:
>
> qemu-storage-daemon: ../block.c:6195: bdrv_get_flags: Assertion
> `qemu_in_main_thread()' failed.
>
> It looks like in this case making bdrv_get_flags() not a GS function
> would be feasible and might solve the problem, but I guess we should
> instead think about adding something like
>
> if (!exp->growable && !qemu_in_main_thread()) {
> /* Changing permissions like below only works in the main thread */
> return -EPERM;
> }
>
> to fuse_do_truncate().
>
> Ideally, to make up for this, we should probably take the RESIZE
> permission in fuse_export_create() for writable exports in iothreads.
I think I got it. I will send the RESIZE permission fix in a separate patch.
Thank you,
Emanuele
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 05/31] block-backend: special comments for blk_set/get_perm due to fuse
2021-12-15 8:57 ` Emanuele Giuseppe Esposito
@ 2021-12-15 10:13 ` Emanuele Giuseppe Esposito
2021-12-16 14:00 ` Hanna Reitz
0 siblings, 1 reply; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-12-15 10:13 UTC (permalink / raw)
To: Hanna Reitz, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 15/12/2021 09:57, Emanuele Giuseppe Esposito wrote:
>
>
> On 10/12/2021 15:38, Hanna Reitz wrote:
>> On 24.11.21 07:43, Emanuele Giuseppe Esposito wrote:
>>> Fuse logic can be classified as I/O, so there is no BQL held
>>> during its execution. And yet, it uses blk_{get/set}_perm
>>> functions, that are classified as BQL and clearly require
>>> the BQL lock. Since there is no easy solution for this,
>>> add a couple of TODOs and FIXME in the relevant sections of the
>>> code.
>>
>> Well, the problem goes deeper, because we still consider them GS
>> functions. So it’s fine for the permission function
>> raw_handle_perm_lock() to call bdrv_get_flags(), which is a GS
>> function, and then you still get:
>>
>> qemu-storage-daemon: ../block.c:6195: bdrv_get_flags: Assertion
>> `qemu_in_main_thread()' failed.
Wait... Now that I read it more carefully I am confused about this. I
don't think the above has to do with fuse, right?
Can you share the command that makes qemu-storage-daemon fail?
raw_handle_perm_lock() is currently called by these three callbacks:
.bdrv_check_perm = raw_check_perm,
.bdrv_set_perm = raw_set_perm,
.bdrv_abort_perm_update = raw_abort_perm_update,
all three function pointers are defined as GS functions. So I don't
understand why is this failing.
>>
>> It looks like in this case making bdrv_get_flags() not a GS function
>> would be feasible and might solve the problem, but I guess we should
>> instead think about adding something like
>>
>> if (!exp->growable && !qemu_in_main_thread()) {
>> /* Changing permissions like below only works in the main thread */
>> return -EPERM;
>> }
>>
>> to fuse_do_truncate().
>>
>> Ideally, to make up for this, we should probably take the RESIZE
>> permission in fuse_export_create() for writable exports in iothreads.
>
> I think I got it. I will send the RESIZE permission fix in a separate
> patch.
>
> Thank you,
> Emanuele
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 05/31] block-backend: special comments for blk_set/get_perm due to fuse
2021-12-15 10:13 ` Emanuele Giuseppe Esposito
@ 2021-12-16 14:00 ` Hanna Reitz
0 siblings, 0 replies; 66+ messages in thread
From: Hanna Reitz @ 2021-12-16 14:00 UTC (permalink / raw)
To: Emanuele Giuseppe Esposito, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 15.12.21 11:13, Emanuele Giuseppe Esposito wrote:
>
>
> On 15/12/2021 09:57, Emanuele Giuseppe Esposito wrote:
>>
>>
>> On 10/12/2021 15:38, Hanna Reitz wrote:
>>> On 24.11.21 07:43, Emanuele Giuseppe Esposito wrote:
>>>> Fuse logic can be classified as I/O, so there is no BQL held
>>>> during its execution. And yet, it uses blk_{get/set}_perm
>>>> functions, that are classified as BQL and clearly require
>>>> the BQL lock. Since there is no easy solution for this,
>>>> add a couple of TODOs and FIXME in the relevant sections of the
>>>> code.
>>>
>>> Well, the problem goes deeper, because we still consider them GS
>>> functions. So it’s fine for the permission function
>>> raw_handle_perm_lock() to call bdrv_get_flags(), which is a GS
>>> function, and then you still get:
>>>
>>> qemu-storage-daemon: ../block.c:6195: bdrv_get_flags: Assertion
>>> `qemu_in_main_thread()' failed.
>
> Wait... Now that I read it more carefully I am confused about this. I
> don't think the above has to do with fuse, right?
It does, because the problem is that the FUSE export code
(fuse_do_truncate()) calls a permission function (blk_set_perm()), and
then we assume in those permission functions that they can call GS
functions, like bdrv_get_flags() (called from raw_handle_perm_lock()).
So in practice, the permission functions are still effectively GS
functions, and just dropping the assertions from blk_set/get_perm()
doesn’t really help.
(This is the state on this patch; patch 7 adds an assertion in
bdrv_child_try_set_perm(), and so from then on, that assertion fails
before the one in bdrv_get_flags() can.)
> Can you share the command that makes qemu-storage-daemon fail?
Sure:
$ touch /tmp/fuse-export
$ storage-daemon/qemu-storage-daemon \
--object iothread,id=iothr0 \
--blockdev file,node-name=node0,filename=/tmp/fuse-export \
--export
fuse,id=exp0,node-name=node0,mountpoint=/tmp/fuse-export,iothread=iothr0,writable=true
\
&
[1] 96997
$ truncate /tmp/fuse-export -s 1M
qemu-storage-daemon: ../block.c:6197: bdrv_get_flags: Assertion
`qemu_in_main_thread()' failed.
truncate: failed to truncate '/tmp/fuse-export' at 1048576 bytes:
Software caused connection abort
truncate: failed to close '/tmp/fuse-export': Transport endpoint is not
connected
[1] + 96997 IOT instruction (core dumped)
storage-daemon/qemu-storage-daemon --object iothread,id=iothr0 --blockdev
$ fusermount -u /tmp/fuse-export
Relevant part of the stacktrace:
#5 0x00007f68322243a6 in __GI___assert_fail
(assertion=assertion@entry=0x562380ca2f53 "qemu_in_main_thread()",
file=file@entry=0x562380ca53cd "../block.c", line=line@entry=6197,
function=function@entry=0x562380ca78e8 <__PRETTY_FUNCTION__.63>
"bdrv_get_flags") at assert.c:101
#6 0x0000562380b64283 in bdrv_get_flags (bs=0x562382440680) at
../block.c:6197
#7 0x0000562380b68506 in bdrv_get_flags (bs=bs@entry=0x562382440680) at
../block.c:6199
#8 0x0000562380be6d18 in raw_handle_perm_lock (errp=0x7f68277103b0,
new_shared=31, new_perm=11, op=RAW_PL_PREPARE, bs=0x562382440680) at
../block/file-posix.c:975
#9 raw_check_perm (bs=0x562382440680, perm=11, shared=31,
errp=0x7f68277103b0) at ../block/file-posix.c:3172
#10 0x0000562380b66db5 in bdrv_drv_set_perm (errp=0x7f68277103b0,
tran=0x7f68180038b0, shared_perm=31, perm=11, bs=0x562382440680) at
../block.c:2272
#11 bdrv_node_refresh_perm (errp=0x7f68277103b0, tran=0x7f68180038b0,
q=0x0, bs=0x562382440680) at ../block.c:2441
#12 bdrv_list_refresh_perms (list=list@entry=0x56238243a1c0 = {...},
q=q@entry=0x0, tran=tran@entry=0x7f68180038b0,
errp=errp@entry=0x7f68277103b0) at ../block.c:2479
#13 0x0000562380b67098 in bdrv_refresh_perms (bs=0x562382440680,
errp=errp@entry=0x7f68277103b0) at ../block.c:2542
#14 0x0000562380b6727c in bdrv_child_try_set_perm (c=0x56238243cf70,
perm=11, shared=31, errp=0x0) at ../block.c:2557
#15 0x0000562380b8632d in blk_set_perm (blk=0x56238243e7a0, perm=11,
shared_perm=31, errp=errp@entry=0x0) at ../block/block-backend.c:890
#16 0x0000562380b57a7d in fuse_do_truncate
(exp=exp@entry=0x56238243eb20, size=1048576,
req_zero_write=req_zero_write@entry=true,
prealloc=prealloc@entry=PREALLOC_MODE_OFF) at ../block/export/fuse.c:405
#17 0x0000562380b58121 in fuse_setattr (req=0x7f6818003800, inode=1,
statbuf=0x7f68277104e0, to_set=8, fi=0x7f68277104b0) at
../block/export/fuse.c:476
> raw_handle_perm_lock() is currently called by these three callbacks:
> .bdrv_check_perm = raw_check_perm,
> .bdrv_set_perm = raw_set_perm,
> .bdrv_abort_perm_update = raw_abort_perm_update,
>
> all three function pointers are defined as GS functions. So I don't
> understand why is this failing.
Because this patch explicitly allows I/O code to call
blk_set/get_perm(). But as you rightly say, all permission functions
are still classified as GS code, so we can’t allow it.
Hanna
>>>
>>> It looks like in this case making bdrv_get_flags() not a GS function
>>> would be feasible and might solve the problem, but I guess we should
>>> instead think about adding something like
>>>
>>> if (!exp->growable && !qemu_in_main_thread()) {
>>> /* Changing permissions like below only works in the main
>>> thread */
>>> return -EPERM;
>>> }
>>>
>>> to fuse_do_truncate().
>>>
>>> Ideally, to make up for this, we should probably take the RESIZE
>>> permission in fuse_export_create() for writable exports in iothreads.
>>
>> I think I got it. I will send the RESIZE permission fix in a separate
>> patch.
>>
>> Thank you,
>> Emanuele
>
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 09/31] block: introduce assert_bdrv_graph_writable
2021-12-14 19:48 ` Emanuele Giuseppe Esposito
@ 2021-12-16 14:01 ` Hanna Reitz
0 siblings, 0 replies; 66+ messages in thread
From: Hanna Reitz @ 2021-12-16 14:01 UTC (permalink / raw)
To: Emanuele Giuseppe Esposito, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 14.12.21 20:48, Emanuele Giuseppe Esposito wrote:
>
>
> On 10/12/2021 18:43, Hanna Reitz wrote:
>> On 24.11.21 07:43, Emanuele Giuseppe Esposito wrote:
>>> We want to be sure that the functions that write the child and
>>> parent list of a bs are under BQL and drain.
>>>
>>> BQL prevents from concurrent writings from the GS API, while
>>> drains protect from I/O.
>>>
>>> TODO: drains are missing in some functions using this assert.
>>> Therefore a proper assertion will fail. Because adding drains
>>> requires additional discussions, they will be added in future
>>> series.
>>>
>>> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
>>> ---
>>> include/block/block_int-global-state.h | 10 +++++++++-
>>> block.c | 4 ++++
>>> block/io.c | 11 +++++++++++
>>> 3 files changed, 24 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/include/block/block_int-global-state.h
>>> b/include/block/block_int-global-state.h
>>> index a1b7d0579d..fa96e8b449 100644
>>> --- a/include/block/block_int-global-state.h
>>> +++ b/include/block/block_int-global-state.h
>>> @@ -312,4 +312,12 @@ void
>>> bdrv_remove_aio_context_notifier(BlockDriverState *bs,
>>> */
>>> void bdrv_drain_all_end_quiesce(BlockDriverState *bs);
>>> -#endif /* BLOCK_INT_GLOBAL_STATE*/
>>
>> This looks like it should be squashed into patch 7, sorry I missed
>> this in v4...
>>
>> (Rest of this patch looks good to me, for the record – and while I’m
>> at it, for patches I didn’t reply to so far, I planned to send an R-b
>> later. But then there’s things like patches 2/3 looking good to me,
>> but it turned out in my review for patch 4 that bdrv_lock_medium() is
>> used in an I/O path, so I can’t really send an R-b now anymore...)
>>
> Sorry I don't understand this, what should be squashed into patch 7?
> The assertion? If so, why?
No, the
-#endif /* BLOCK_INT_GLOBAL_STATE*/
+#endif /* BLOCK_INT_GLOBAL_STATE */
part of the hunk.
Hanna
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 10/31] block.c: modify .attach and .detach callbacks of child_of_bds
2021-11-24 6:43 ` [PATCH v5 10/31] block.c: modify .attach and .detach callbacks of child_of_bds Emanuele Giuseppe Esposito
@ 2021-12-16 14:57 ` Hanna Reitz
2021-12-16 16:05 ` Emanuele Giuseppe Esposito
0 siblings, 1 reply; 66+ messages in thread
From: Hanna Reitz @ 2021-12-16 14:57 UTC (permalink / raw)
To: Emanuele Giuseppe Esposito, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 24.11.21 07:43, Emanuele Giuseppe Esposito wrote:
> According to the assertions put in the previous patch, we should
> first drain and then modify the ->children list. In this way
> we prevent other iothreads to read the list while it is being
> updated.
>
> In this case, moving the drain won't cause any harm, because
> child is a parameter of the drain function so it will still be
> included in the operation, despite not being in the list.
Sounds good.
> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
> ---
> block.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/block.c b/block.c
> index 522a273140..5516c84ec4 100644
> --- a/block.c
> +++ b/block.c
> @@ -1416,6 +1416,7 @@ static void bdrv_child_cb_attach(BdrvChild *child)
> {
> BlockDriverState *bs = child->opaque;
>
> + bdrv_apply_subtree_drain(child, bs);
> assert_bdrv_graph_writable(bs);
> QLIST_INSERT_HEAD(&bs->children, child, next);
>
> @@ -1423,7 +1424,6 @@ static void bdrv_child_cb_attach(BdrvChild *child)
> bdrv_backing_attach(child);
> }
>
> - bdrv_apply_subtree_drain(child, bs);
I think we should also remove the empty line above.
Hanna
> }
>
> static void bdrv_child_cb_detach(BdrvChild *child)
> @@ -1434,10 +1434,9 @@ static void bdrv_child_cb_detach(BdrvChild *child)
> bdrv_backing_detach(child);
> }
>
> - bdrv_unapply_subtree_drain(child, bs);
> -
> assert_bdrv_graph_writable(bs);
> QLIST_REMOVE(child, next);
> + bdrv_unapply_subtree_drain(child, bs);
> }
>
> static int bdrv_child_cb_update_filename(BdrvChild *c, BlockDriverState *base,
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 03/31] assertions for block global state API
2021-11-24 6:43 ` [PATCH v5 03/31] assertions for block " Emanuele Giuseppe Esposito
@ 2021-12-16 15:17 ` Hanna Reitz
0 siblings, 0 replies; 66+ messages in thread
From: Hanna Reitz @ 2021-12-16 15:17 UTC (permalink / raw)
To: Emanuele Giuseppe Esposito, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 24.11.21 07:43, Emanuele Giuseppe Esposito wrote:
> All the global state (GS) API functions will check that
> qemu_in_main_thread() returns true. If not, it means
> that the safety of BQL cannot be guaranteed, and
> they need to be moved to I/O.
>
> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
> ---
> block.c | 135 ++++++++++++++++++++++++++++++++++++++++++++++++-
> block/commit.c | 2 +
> block/io.c | 14 +++++
> blockdev.c | 1 +
> 4 files changed, 150 insertions(+), 2 deletions(-)
>
> diff --git a/block.c b/block.c
> index 84de6867e6..49bee69e27 100644
> --- a/block.c
> +++ b/block.c
[...]
> @@ -975,6 +992,7 @@ BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
> {
> int score_max = 0, score;
> BlockDriver *drv = NULL, *d;
> + assert(qemu_in_main_thread());
While reviewing patch 13 and the find_image_format() it touches, I
noticed that this function is called from raw_co_pwritev() to prevent
the guest from writing image headers into probed-raw images.
Reproducible like so:
$ qemu-img create -f raw test.img 64M
Formatting 'test.img', fmt=raw size=67108864
$ ./qemu-system-x86_64 \
-object iothread,id=iothr0 \
-drive if=none,id=drv0,file=test.img \
-device virtio-blk,drive=drv0,iothread=iothr0 \
-monitor stdio
WARNING: Image format was not specified for 'test.img' and probing
guessed raw.
Automatically detecting the format is dangerous for raw
images, write operations on block 0 will be restricted.
Specify the 'raw' format explicitly to remove the restrictions.
QEMU 6.1.93 monitor - type 'help' for more information
(qemu) qemu-io drv0 "write 0 512"
qemu-system-x86_64: ../block.c:1004: bdrv_probe_all: Assertion
`qemu_in_main_thread()' failed.
[1] 108256 IOT instruction (core dumped) ./qemu-system-x86_64
-object iothread,id=iothr0 -drive -device -monitor
I don’t think there’s any reason not to classify bdrv_probe_all() as an
I/O function then, is there?
(Also, bdrv_probe_all() is part of block_int.h, so this assertion would
actually belong in patch 8, not here.)
Hanna
>
> QLIST_FOREACH(d, &bdrv_drivers, list) {
> if (d->bdrv_probe) {
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 10/31] block.c: modify .attach and .detach callbacks of child_of_bds
2021-12-16 14:57 ` Hanna Reitz
@ 2021-12-16 16:05 ` Emanuele Giuseppe Esposito
2021-12-16 16:12 ` Hanna Reitz
0 siblings, 1 reply; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-12-16 16:05 UTC (permalink / raw)
To: Hanna Reitz, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 16/12/2021 15:57, Hanna Reitz wrote:
> On 24.11.21 07:43, Emanuele Giuseppe Esposito wrote:
>> According to the assertions put in the previous patch, we should
>> first drain and then modify the ->children list. In this way
>> we prevent other iothreads to read the list while it is being
>> updated.
>>
>> In this case, moving the drain won't cause any harm, because
>> child is a parameter of the drain function so it will still be
>> included in the operation, despite not being in the list.
>
> Sounds good.
Uhm.. I don't think this is useful at all. I was thinking to drop this
patch in v6.
My plans on subtree drains, ->children and ->parent lists are explained
in "Removal of Aiocontext lock and usage of subtree drains in aborted
transactions"
https://patchew.org/QEMU/20211213104014.69858-1-eesposit@redhat.com/
And as I say there, commit d736f119da makes sure that it is safe to
modify the graph even side a bdrv_subtree_drained_begin/end() section.
So this should be unnecessary.
Thank you,
Emanuele
>
>> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
>> ---
>> block.c | 5 ++---
>> 1 file changed, 2 insertions(+), 3 deletions(-)
>>
>> diff --git a/block.c b/block.c
>> index 522a273140..5516c84ec4 100644
>> --- a/block.c
>> +++ b/block.c
>> @@ -1416,6 +1416,7 @@ static void bdrv_child_cb_attach(BdrvChild *child)
>> {
>> BlockDriverState *bs = child->opaque;
>> + bdrv_apply_subtree_drain(child, bs);
>> assert_bdrv_graph_writable(bs);
>> QLIST_INSERT_HEAD(&bs->children, child, next);
>> @@ -1423,7 +1424,6 @@ static void bdrv_child_cb_attach(BdrvChild *child)
>> bdrv_backing_attach(child);
>> }
>> - bdrv_apply_subtree_drain(child, bs);
>
> I think we should also remove the empty line above.
>
> Hanna
>
>> }
>> static void bdrv_child_cb_detach(BdrvChild *child)
>> @@ -1434,10 +1434,9 @@ static void bdrv_child_cb_detach(BdrvChild *child)
>> bdrv_backing_detach(child);
>> }
>> - bdrv_unapply_subtree_drain(child, bs);
>> -
>> assert_bdrv_graph_writable(bs);
>> QLIST_REMOVE(child, next);
>> + bdrv_unapply_subtree_drain(child, bs);
>> }
>> static int bdrv_child_cb_update_filename(BdrvChild *c,
>> BlockDriverState *base,
>
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 13/31] block.c: add assertions to static functions
2021-11-24 6:44 ` [PATCH v5 13/31] block.c: add assertions to static functions Emanuele Giuseppe Esposito
@ 2021-12-16 16:08 ` Hanna Reitz
2021-12-16 16:39 ` Emanuele Giuseppe Esposito
0 siblings, 1 reply; 66+ messages in thread
From: Hanna Reitz @ 2021-12-16 16:08 UTC (permalink / raw)
To: Emanuele Giuseppe Esposito, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 24.11.21 07:44, Emanuele Giuseppe Esposito wrote:
> Following the assertion derived from the API split,
> propagate the assertion also in the static functions.
>
> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
> ---
> block.c | 45 ++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 44 insertions(+), 1 deletion(-)
Looks good to me, just one small question:
> diff --git a/block.c b/block.c
> index 5516c84ec4..b77ab0a104 100644
> --- a/block.c
> +++ b/block.c
[...]
> @@ -1241,6 +1252,7 @@ static void bdrv_temp_snapshot_options(int *child_flags, QDict *child_options,
> int parent_flags, QDict *parent_options)
> {
> *child_flags = (parent_flags & ~BDRV_O_SNAPSHOT) | BDRV_O_TEMPORARY;
> + assert(qemu_in_main_thread());
Stylistically, it’s a bit strange that in other places, this assertion
comes right after all local variable declarations, or after some
assertions that are already present in that place; but here, it follows
a normal statement. Is that on purpose?
>
> /* For temporary files, unconditional cache=unsafe is fine */
> qdict_set_default_str(child_options, BDRV_OPT_CACHE_DIRECT, "off");
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 10/31] block.c: modify .attach and .detach callbacks of child_of_bds
2021-12-16 16:05 ` Emanuele Giuseppe Esposito
@ 2021-12-16 16:12 ` Hanna Reitz
0 siblings, 0 replies; 66+ messages in thread
From: Hanna Reitz @ 2021-12-16 16:12 UTC (permalink / raw)
To: Emanuele Giuseppe Esposito, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 16.12.21 17:05, Emanuele Giuseppe Esposito wrote:
>
>
> On 16/12/2021 15:57, Hanna Reitz wrote:
>> On 24.11.21 07:43, Emanuele Giuseppe Esposito wrote:
>>> According to the assertions put in the previous patch, we should
>>> first drain and then modify the ->children list. In this way
>>> we prevent other iothreads to read the list while it is being
>>> updated.
>>>
>>> In this case, moving the drain won't cause any harm, because
>>> child is a parameter of the drain function so it will still be
>>> included in the operation, despite not being in the list.
>>
>> Sounds good.
>
> Uhm.. I don't think this is useful at all. I was thinking to drop this
> patch in v6.
>
> My plans on subtree drains, ->children and ->parent lists are
> explained in "Removal of Aiocontext lock and usage of subtree drains
> in aborted transactions"
>
> https://patchew.org/QEMU/20211213104014.69858-1-eesposit@redhat.com/
>
> And as I say there, commit d736f119da makes sure that it is safe to
> modify the graph even side a bdrv_subtree_drained_begin/end() section.
> So this should be unnecessary.
Sounds good, too. :)
Hanna
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 13/31] block.c: add assertions to static functions
2021-12-16 16:08 ` Hanna Reitz
@ 2021-12-16 16:39 ` Emanuele Giuseppe Esposito
0 siblings, 0 replies; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-12-16 16:39 UTC (permalink / raw)
To: Hanna Reitz, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 16/12/2021 17:08, Hanna Reitz wrote:
> On 24.11.21 07:44, Emanuele Giuseppe Esposito wrote:
>> Following the assertion derived from the API split,
>> propagate the assertion also in the static functions.
>>
>> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
>> ---
>> block.c | 45 ++++++++++++++++++++++++++++++++++++++++++++-
>> 1 file changed, 44 insertions(+), 1 deletion(-)
>
> Looks good to me, just one small question:
>
>> diff --git a/block.c b/block.c
>> index 5516c84ec4..b77ab0a104 100644
>> --- a/block.c
>> +++ b/block.c
>
> [...]
>
>> @@ -1241,6 +1252,7 @@ static void bdrv_temp_snapshot_options(int
>> *child_flags, QDict *child_options,
>> int parent_flags, QDict
>> *parent_options)
>> {
>> *child_flags = (parent_flags & ~BDRV_O_SNAPSHOT) |
>> BDRV_O_TEMPORARY;
>> + assert(qemu_in_main_thread());
>
> Stylistically, it’s a bit strange that in other places, this assertion
> comes right after all local variable declarations, or after some
> assertions that are already present in that place; but here, it follows
> a normal statement. Is that on purpose?
Nope :) Just a misread, I don't even recall when I added this.
But I appreciate the investigative spirit :)
>
>> /* For temporary files, unconditional cache=unsafe is fine */
>> qdict_set_default_str(child_options, BDRV_OPT_CACHE_DIRECT, "off");
>
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 22/31] block_int-common.h: assertion in the callers of BlockDriver function pointers
2021-11-24 6:44 ` [PATCH v5 22/31] block_int-common.h: assertion in the callers of BlockDriver function pointers Emanuele Giuseppe Esposito
@ 2021-12-16 18:43 ` Hanna Reitz
2021-12-17 15:53 ` Emanuele Giuseppe Esposito
0 siblings, 1 reply; 66+ messages in thread
From: Hanna Reitz @ 2021-12-16 18:43 UTC (permalink / raw)
To: Emanuele Giuseppe Esposito, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 24.11.21 07:44, Emanuele Giuseppe Esposito wrote:
> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
> block.c | 18 ++++++++++++++++++
> block/create.c | 10 ++++++++++
> 2 files changed, 28 insertions(+)
[...]
> diff --git a/block/create.c b/block/create.c
> index 89812669df..0167118579 100644
> --- a/block/create.c
> +++ b/block/create.c
> @@ -42,6 +42,16 @@ static int coroutine_fn blockdev_create_run(Job *job, Error **errp)
> BlockdevCreateJob *s = container_of(job, BlockdevCreateJob, common);
> int ret;
>
> + /*
> + * Currently there is nothing preventing this
> + * function from being called in an iothread context.
> + * However, since it will crash anyways because of the
> + * aiocontext lock not taken, we might as well make it
> + * crash with a more meaningful error, by checking that
> + * we are in the main loop
> + */
> + assert(qemu_in_main_thread());
Mostly agreed. This function is always run in the main loop right now,
so this assertion will never fail.
But that’s the “mostly”: Adding this assertion won’t give a more
meaningful error, because the problem still remains that block drivers
do not error out when encountering (or correctly handle) BDSs in
non-main contexts, and so it remains a “qemu_mutex_unlock_impl:
Operation not permitted”.
Not trying to say that that’s your problem. It’s pre-existing, and this
assertion is good. Just wanting to clarify something about the comment
that seemed unclear to me (in that I found it implied that the
qemu_mutex_unlock_impl error would be replaced by this assertion failing).
Hanna
> +
> job_progress_set_remaining(&s->common, 1);
> ret = s->drv->bdrv_co_create(s->opts, errp);
> job_progress_update(&s->common, 1);
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 28/31] block.c: assert BQL lock held in bdrv_co_invalidate_cache
2021-11-24 6:44 ` [PATCH v5 28/31] block.c: assert BQL lock held in bdrv_co_invalidate_cache Emanuele Giuseppe Esposito
@ 2021-12-17 11:04 ` Hanna Reitz
2021-12-17 16:38 ` Emanuele Giuseppe Esposito
0 siblings, 1 reply; 66+ messages in thread
From: Hanna Reitz @ 2021-12-17 11:04 UTC (permalink / raw)
To: Emanuele Giuseppe Esposito, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 24.11.21 07:44, Emanuele Giuseppe Esposito wrote:
> bdrv_co_invalidate_cache is special: it is an I/O function,
I still don’t believe it is, but well.
(Yes, it is called by a test in an iothread, but I believe we’ve seen
that the tests simply sometimes test things that shouldn’t be allowed.)
> but uses the block layer permission API, which is GS.
>
> Because of this, we can assert that either the function is
> being called with BQL held, and thus can use the permission API,
> or make sure that the permission API is not used, by ensuring that
> bs (and parents) .open_flags does not contain BDRV_O_INACTIVE.
>
> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
> ---
> block.c | 26 ++++++++++++++++++++++++++
> 1 file changed, 26 insertions(+)
>
> diff --git a/block.c b/block.c
> index a0309f827d..805974676b 100644
> --- a/block.c
> +++ b/block.c
> @@ -6574,6 +6574,26 @@ void bdrv_init_with_whitelist(void)
> bdrv_init();
> }
>
> +static bool bdrv_is_active(BlockDriverState *bs)
> +{
> + BdrvChild *parent;
> +
> + if (bs->open_flags & BDRV_O_INACTIVE) {
> + return false;
> + }
> +
> + QLIST_FOREACH(parent, &bs->parents, next_parent) {
> + if (parent->klass->parent_is_bds) {
> + BlockDriverState *parent_bs = parent->opaque;
This looks like a really bad hack to me. We purposefully have made the
parent link opaque so that a BDS cannot easily reach its parents. All
accesses should go through BdrvChildClass methods.
I also don’t understand why we need to query parents at all. The only
fact that determines whether the current BDS will have its permissions
changed is whether the BDS itself is active or inactive. Sure, we’ll
invoke bdrv_co_invalidate_cache() on the parents, too, but then we could
simply let the assertion fail there.
> + if (!bdrv_is_active(parent_bs)) {
> + return false;
> + }
> + }
> + }
> +
> + return true;
> +}
> +
> int coroutine_fn bdrv_co_invalidate_cache(BlockDriverState *bs, Error **errp)
> {
> BdrvChild *child, *parent;
> @@ -6585,6 +6605,12 @@ int coroutine_fn bdrv_co_invalidate_cache(BlockDriverState *bs, Error **errp)
> return -ENOMEDIUM;
> }
>
> + /*
> + * No need to muck with permissions if bs is active.
> + * TODO: should activation be a separate function?
> + */
> + assert(qemu_in_main_thread() || bdrv_is_active(bs));
> +
I don’t understand this, really. It looks to me like “if you don’t call
this in the main thread, this better be a no-op”, i.e., you must never
call this function in an I/O thread if you really want to use it. I.e.
what I’d classify as a GS function.
It sounds like this is just a special case for said test, and
special-casing code for tests sounds like a bad idea.
Hanna
> QLIST_FOREACH(child, &bs->children, next) {
> bdrv_co_invalidate_cache(child->bs, &local_err);
> if (local_err) {
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 30/31] crypto: delegate permission functions to JobDriver .pre_run
2021-11-24 6:44 ` [PATCH v5 30/31] crypto: delegate permission functions to JobDriver .pre_run Emanuele Giuseppe Esposito
@ 2021-12-17 12:29 ` Hanna Reitz
2021-12-17 14:32 ` Hanna Reitz
2021-12-20 15:47 ` Emanuele Giuseppe Esposito
0 siblings, 2 replies; 66+ messages in thread
From: Hanna Reitz @ 2021-12-17 12:29 UTC (permalink / raw)
To: Emanuele Giuseppe Esposito, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 24.11.21 07:44, Emanuele Giuseppe Esposito wrote:
> block_crypto_amend_options_generic_luks uses the block layer
> permission API, therefore it should be called with the BQL held.
>
> However, the same function is being called ib two BlockDriver
s/ ib / by /
> callbacks: bdrv_amend_options (under BQL) and bdrv_co_amend (I/O).
>
> The latter is I/O because it is invoked by block/amend.c's
> blockdev_amend_run(), a .run callback of the amend JobDriver
>
> Therefore we want to 1) change block_crypto_amend_options_generic_luks
> to use the permission API only when the BQL is held, and
> 2) use the .pre_run JobDriver callback to check for
> permissions before switching to the job aiocontext. This has also
> the benefit of applying the same permission operation to all
> amend implementations, not only luks.
>
> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
> ---
> block/amend.c | 20 ++++++++++++++++++++
> block/crypto.c | 18 ++++++++++++------
> 2 files changed, 32 insertions(+), 6 deletions(-)
>
> diff --git a/block/amend.c b/block/amend.c
> index 392df9ef83..fba6add51a 100644
> --- a/block/amend.c
> +++ b/block/amend.c
> @@ -53,10 +53,30 @@ static int coroutine_fn blockdev_amend_run(Job *job, Error **errp)
> return ret;
> }
>
> +static int blockdev_amend_refresh_perms(Job *job, Error **errp)
> +{
> + BlockdevAmendJob *s = container_of(job, BlockdevAmendJob, common);
> +
> + return bdrv_child_refresh_perms(s->bs, s->bs->file, errp);
> +}
I miss some documentation for this function, why we do it and how it
works together with the bdrv_co_amend implementation.
I was trying to come up with an example text, but then I wondered – how
does it actually work? bdrv_child_refresh_perms() eventually ends up in
block_crypto_child_perms(). However, that will only return exceptional
permissions if crypto->updating_keys is true. But that’s set only in
block_crypto_amend_options_generic_luks() – i.e. when the job runs.
That’s exactly why that function calls bdrv_child_refresh_perms() only
after it has modified crypto->updating_keys.
Reproducer (amend on a LUKS image with read-only=true, so it doesn’t
have the WRITE permission continuously, but needs to take it as an
exception in block_crypto_child_perms()):
$ qemu-img create \
-f luks \
--object secret,id=sec0,data=123456 \
-o key-secret=sec0 \
test.luks \
64M
Formatting 'test.luks', fmt=luks size=67108864 key-secret=sec0
$ ./qemu-system-x86_64 \
-object secret,id=sec0,data=123456 \
-object iothread,id=iothr0 \
-blockdev file,node-name=node0,filename=test.luks \
-blockdev
luks,node-name=node1,key-secret=sec0,file=node0,read-only=true \
-device virtio-blk,drive=node1,iothread=iothr0 -qmp stdio \
<<EOF
{"execute": "qmp_capabilities"}
{
"execute": "x-blockdev-amend",
"arguments": {
"job-id": "amend0",
"node-name": "node1",
"options": {
"driver": "luks",
"state": "active",
"new-secret": "sec0"
}
}
}
EOF
{"QMP": {"version": {"qemu": {"micro": 93, "minor": 1, "major": 6},
"package": "v6.2.0-rc3-50-gdb635fc4e7"}, "capabilities": ["oob"]}}
{"return": {}}
{"timestamp": {"seconds": 1639742600, "microseconds": 574641}, "event":
"JOB_STATUS_CHANGE", "data": {"status": "created", "id": "amend0"}}
{"timestamp": {"seconds": 1639742600, "microseconds": 574919}, "event":
"JOB_STATUS_CHANGE", "data": {"status": "running", "id": "amend0"}}
{"return": {}}
qemu-system-x86_64: ../block/io.c:2041: bdrv_co_write_req_prepare:
Assertion `child->perm & BLK_PERM_WRITE' failed.
[1] 55880 IOT instruction (core dumped) ./qemu-system-x86_64 -object
secret,id=sec0,data=123456 -object -blockdev
I believe this means we need some new block driver function to prepare
for an amendment operation. If so, another question comes up, which is
whether this preparatory function should then also call
bdrv_child_refresh_perms(), and then whether we should have a clean-up
function for symmetry.
> +
> +static int blockdev_amend_pre_run(Job *job, Error **errp)
> +{
> + return blockdev_amend_refresh_perms(job, errp);
> +}
> +
> +static void blockdev_amend_clean(Job *job)
> +{
> + Error *errp;
> + blockdev_amend_refresh_perms(job, &errp);
Do we really want to ignore this error? If so, we shouldn’t pass a
pointer to an unused local variable, but NULL.
If we don’t want to ignore it, we have the option of doing what you do
here and then at least reporting a potential error with
error_report_err(), and then freeing it, and we also must initialize
errp to NULL in this case.
If we expect no error to happen (e.g. because we require the amend
implementation to only release/share permissions and not acquire/unshare
them), then I’d expect passing &error_abort here.
> +}
> +
> static const JobDriver blockdev_amend_job_driver = {
> .instance_size = sizeof(BlockdevAmendJob),
> .job_type = JOB_TYPE_AMEND,
> .run = blockdev_amend_run,
> + .pre_run = blockdev_amend_pre_run,
> + .clean = blockdev_amend_clean,
> };
>
> void qmp_x_blockdev_amend(const char *job_id,
> diff --git a/block/crypto.c b/block/crypto.c
> index c8ba4681e2..82f154516c 100644
> --- a/block/crypto.c
> +++ b/block/crypto.c
> @@ -780,6 +780,7 @@ block_crypto_get_specific_info_luks(BlockDriverState *bs, Error **errp)
> static int
> block_crypto_amend_options_generic_luks(BlockDriverState *bs,
> QCryptoBlockAmendOptions *amend_options,
> + bool under_bql,
This name makes sense in the context of this series, but not so much
outside of it.
I’d rename it to e.g. “in_amend_job” (and invert its value), and then
explain that we don’t need to refresh the child permissions when running
in an amend job, because that job has already taken care of that.
OTOH, given that I believe we need some separate preparatory function
anyway, perhaps we should just pull out the bdrv_child_refresh_perms()
from this function altogether, so that we have:
block_crypto_amend_options_luks():
/* sets updating_keys to true, and invokes bdrv_child_refresh_perms() */
block_crypto_amend_options_prepare();
block_crypto_amend_options_generic_luks();
/* sets updating_keys to false, and invokes bdrv_child_refresh_perms() */
block_crypto_amend_options_clean();
block_crypto_co_amend_luks():
/* No need to prepare or clean up, that is taken care of by the amend job */
block_crypto_amend_options_generic_luks();
(If we decide not to put bdrv_child_refresh_perms() into
prepare()/clean(), then it would need to be called by
block_crypto_amend_options_luks(); and if we decide not to have a
block_crypto_amend_options_clean(), then we’d need to inline it fully.)
Hanna
> bool force,
> Error **errp)
> {
> @@ -791,9 +792,12 @@ block_crypto_amend_options_generic_luks(BlockDriverState *bs,
>
> /* apply for exclusive read/write permissions to the underlying file*/
> crypto->updating_keys = true;
> - ret = bdrv_child_refresh_perms(bs, bs->file, errp);
> - if (ret) {
> - goto cleanup;
> +
> + if (under_bql) {
> + ret = bdrv_child_refresh_perms(bs, bs->file, errp);
> + if (ret) {
> + goto cleanup;
> + }
> }
>
> ret = qcrypto_block_amend_options(crypto->block,
> @@ -806,7 +810,9 @@ block_crypto_amend_options_generic_luks(BlockDriverState *bs,
> cleanup:
> /* release exclusive read/write permissions to the underlying file*/
> crypto->updating_keys = false;
> - bdrv_child_refresh_perms(bs, bs->file, errp);
> + if (under_bql) {
> + bdrv_child_refresh_perms(bs, bs->file, errp);
> + }
> return ret;
> }
>
> @@ -834,7 +840,7 @@ block_crypto_amend_options_luks(BlockDriverState *bs,
> goto cleanup;
> }
> ret = block_crypto_amend_options_generic_luks(bs, amend_options,
> - force, errp);
> + true, force, errp);
> cleanup:
> qapi_free_QCryptoBlockAmendOptions(amend_options);
> return ret;
> @@ -853,7 +859,7 @@ coroutine_fn block_crypto_co_amend_luks(BlockDriverState *bs,
> .u.luks = *qapi_BlockdevAmendOptionsLUKS_base(&opts->u.luks),
> };
> return block_crypto_amend_options_generic_luks(bs, &amend_opts,
> - force, errp);
> + false, force, errp);
> }
>
> static void
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 30/31] crypto: delegate permission functions to JobDriver .pre_run
2021-12-17 12:29 ` Hanna Reitz
@ 2021-12-17 14:32 ` Hanna Reitz
2021-12-20 15:47 ` Emanuele Giuseppe Esposito
1 sibling, 0 replies; 66+ messages in thread
From: Hanna Reitz @ 2021-12-17 14:32 UTC (permalink / raw)
To: Emanuele Giuseppe Esposito, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 17.12.21 13:29, Hanna Reitz wrote:
> On 24.11.21 07:44, Emanuele Giuseppe Esposito wrote:
>> block_crypto_amend_options_generic_luks uses the block layer
>> permission API, therefore it should be called with the BQL held.
>>
>> However, the same function is being called ib two BlockDriver
>
> s/ ib / by /
>
>> callbacks: bdrv_amend_options (under BQL) and bdrv_co_amend (I/O).
>>
>> The latter is I/O because it is invoked by block/amend.c's
>> blockdev_amend_run(), a .run callback of the amend JobDriver
>>
>> Therefore we want to 1) change block_crypto_amend_options_generic_luks
>> to use the permission API only when the BQL is held, and
>> 2) use the .pre_run JobDriver callback to check for
>> permissions before switching to the job aiocontext. This has also
>> the benefit of applying the same permission operation to all
>> amend implementations, not only luks.
>>
>> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
>> ---
>> block/amend.c | 20 ++++++++++++++++++++
>> block/crypto.c | 18 ++++++++++++------
>> 2 files changed, 32 insertions(+), 6 deletions(-)
>>
>> diff --git a/block/amend.c b/block/amend.c
>> index 392df9ef83..fba6add51a 100644
>> --- a/block/amend.c
>> +++ b/block/amend.c
>> @@ -53,10 +53,30 @@ static int coroutine_fn blockdev_amend_run(Job
>> *job, Error **errp)
>> return ret;
>> }
>> +static int blockdev_amend_refresh_perms(Job *job, Error **errp)
>> +{
>> + BlockdevAmendJob *s = container_of(job, BlockdevAmendJob, common);
>> +
>> + return bdrv_child_refresh_perms(s->bs, s->bs->file, errp);
>> +}
>
> I miss some documentation for this function, why we do it and how it
> works together with the bdrv_co_amend implementation.
>
> I was trying to come up with an example text, but then I wondered –
> how does it actually work? bdrv_child_refresh_perms() eventually ends
> up in block_crypto_child_perms(). However, that will only return
> exceptional permissions if crypto->updating_keys is true. But that’s
> set only in block_crypto_amend_options_generic_luks() – i.e. when the
> job runs. That’s exactly why that function calls
> bdrv_child_refresh_perms() only after it has modified
> crypto->updating_keys.
>
> Reproducer (amend on a LUKS image with read-only=true, so it doesn’t
> have the WRITE permission continuously, but needs to take it as an
> exception in block_crypto_child_perms()):
>
> $ qemu-img create \
> -f luks \
> --object secret,id=sec0,data=123456 \
> -o key-secret=sec0 \
> test.luks \
> 64M
> Formatting 'test.luks', fmt=luks size=67108864 key-secret=sec0
>
> $ ./qemu-system-x86_64 \
> -object secret,id=sec0,data=123456 \
> -object iothread,id=iothr0 \
> -blockdev file,node-name=node0,filename=test.luks \
> -blockdev
> luks,node-name=node1,key-secret=sec0,file=node0,read-only=true \
> -device virtio-blk,drive=node1,iothread=iothr0 -qmp stdio \
> <<EOF
> {"execute": "qmp_capabilities"}
> {
> "execute": "x-blockdev-amend",
> "arguments": {
> "job-id": "amend0",
> "node-name": "node1",
> "options": {
> "driver": "luks",
> "state": "active",
> "new-secret": "sec0"
> }
> }
> }
> EOF
>
> {"QMP": {"version": {"qemu": {"micro": 93, "minor": 1, "major": 6},
> "package": "v6.2.0-rc3-50-gdb635fc4e7"}, "capabilities": ["oob"]}}
> {"return": {}}
> {"timestamp": {"seconds": 1639742600, "microseconds": 574641},
> "event": "JOB_STATUS_CHANGE", "data": {"status": "created", "id":
> "amend0"}}
> {"timestamp": {"seconds": 1639742600, "microseconds": 574919},
> "event": "JOB_STATUS_CHANGE", "data": {"status": "running", "id":
> "amend0"}}
> {"return": {}}
> qemu-system-x86_64: ../block/io.c:2041: bdrv_co_write_req_prepare:
> Assertion `child->perm & BLK_PERM_WRITE' failed.
> [1] 55880 IOT instruction (core dumped) ./qemu-system-x86_64
> -object secret,id=sec0,data=123456 -object -blockdev
Addendum: Running the iotests, I realized that (because 295 and 296 fail
for luks) of course it doesn’t matter whether the job runs in the main
loop or not in order to reproduce this assertion failure, so the
`-object iothread,id=iothr0` and `-device
virtio-blk,drive=node1,iothread=iothr0` can be dropped from the qemu
command line.
Hanna
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 22/31] block_int-common.h: assertion in the callers of BlockDriver function pointers
2021-12-16 18:43 ` Hanna Reitz
@ 2021-12-17 15:53 ` Emanuele Giuseppe Esposito
2021-12-17 16:00 ` Hanna Reitz
0 siblings, 1 reply; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-12-17 15:53 UTC (permalink / raw)
To: Hanna Reitz, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 16/12/2021 19:43, Hanna Reitz wrote:
> On 24.11.21 07:44, Emanuele Giuseppe Esposito wrote:
>> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
>> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
>> ---
>> block.c | 18 ++++++++++++++++++
>> block/create.c | 10 ++++++++++
>> 2 files changed, 28 insertions(+)
>
> [...]
>
>> diff --git a/block/create.c b/block/create.c
>> index 89812669df..0167118579 100644
>> --- a/block/create.c
>> +++ b/block/create.c
>> @@ -42,6 +42,16 @@ static int coroutine_fn blockdev_create_run(Job
>> *job, Error **errp)
>> BlockdevCreateJob *s = container_of(job, BlockdevCreateJob,
>> common);
>> int ret;
>> + /*
>> + * Currently there is nothing preventing this
>> + * function from being called in an iothread context.
>> + * However, since it will crash anyways because of the
>> + * aiocontext lock not taken, we might as well make it
>> + * crash with a more meaningful error, by checking that
>> + * we are in the main loop
>> + */
>> + assert(qemu_in_main_thread());
>
> Mostly agreed. This function is always run in the main loop right now,
> so this assertion will never fail.
>
> But that’s the “mostly”: Adding this assertion won’t give a more
> meaningful error, because the problem still remains that block drivers
> do not error out when encountering (or correctly handle) BDSs in
> non-main contexts, and so it remains a “qemu_mutex_unlock_impl:
> Operation not permitted”.
>
> Not trying to say that that’s your problem. It’s pre-existing, and this
> assertion is good. Just wanting to clarify something about the comment
> that seemed unclear to me (in that I found it implied that the
> qemu_mutex_unlock_impl error would be replaced by this assertion failing).
>
You are right. Trying your example given in v4:
$ touch /tmp/iothread-create-test.qcow2
$ ./qemu-system-x86_64 -object iothread,id=iothr0 -qmp stdio <<EOF
{"execute": "qmp_capabilities"}
{"execute":"blockdev-add","arguments":{"node-name":"proto","driver":"file","filename":"/tmp/iothread-create-test.qcow2"}}
{"execute":"x-blockdev-set-iothread","arguments":{"node-name":"proto","iothread":"iothr0"}}
{"execute":"blockdev-create","arguments":{"job-id":"create","options":{"driver":"qcow2","file":"proto","size":0}}}
EOF
I still get "qemu_mutex_unlock_impl: Operation not permitted"
I will remove the comment above the assertion, makes no sense.
Or should I replace it with a TODO/FIXME explaining the above? Something
like:
/*
* TODO: it is currently possible to run a blockdev-create job in an
* I/O thread, for example by doing:
* [ command line above ]
* This should not be allowed.
*/
What do you think?
Emanuele
>
>> +
>> job_progress_set_remaining(&s->common, 1);
>> ret = s->drv->bdrv_co_create(s->opts, errp);
>> job_progress_update(&s->common, 1);
>
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 22/31] block_int-common.h: assertion in the callers of BlockDriver function pointers
2021-12-17 15:53 ` Emanuele Giuseppe Esposito
@ 2021-12-17 16:00 ` Hanna Reitz
0 siblings, 0 replies; 66+ messages in thread
From: Hanna Reitz @ 2021-12-17 16:00 UTC (permalink / raw)
To: Emanuele Giuseppe Esposito, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 17.12.21 16:53, Emanuele Giuseppe Esposito wrote:
>
>
> On 16/12/2021 19:43, Hanna Reitz wrote:
>> On 24.11.21 07:44, Emanuele Giuseppe Esposito wrote:
>>> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
>>> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
>>> ---
>>> block.c | 18 ++++++++++++++++++
>>> block/create.c | 10 ++++++++++
>>> 2 files changed, 28 insertions(+)
>>
>> [...]
>>
>>> diff --git a/block/create.c b/block/create.c
>>> index 89812669df..0167118579 100644
>>> --- a/block/create.c
>>> +++ b/block/create.c
>>> @@ -42,6 +42,16 @@ static int coroutine_fn blockdev_create_run(Job
>>> *job, Error **errp)
>>> BlockdevCreateJob *s = container_of(job, BlockdevCreateJob,
>>> common);
>>> int ret;
>>> + /*
>>> + * Currently there is nothing preventing this
>>> + * function from being called in an iothread context.
>>> + * However, since it will crash anyways because of the
>>> + * aiocontext lock not taken, we might as well make it
>>> + * crash with a more meaningful error, by checking that
>>> + * we are in the main loop
>>> + */
>>> + assert(qemu_in_main_thread());
>>
>> Mostly agreed. This function is always run in the main loop right
>> now, so this assertion will never fail.
>>
>> But that’s the “mostly”: Adding this assertion won’t give a more
>> meaningful error, because the problem still remains that block
>> drivers do not error out when encountering (or correctly handle) BDSs
>> in non-main contexts, and so it remains a “qemu_mutex_unlock_impl:
>> Operation not permitted”.
>>
>> Not trying to say that that’s your problem. It’s pre-existing, and
>> this assertion is good. Just wanting to clarify something about the
>> comment that seemed unclear to me (in that I found it implied that
>> the qemu_mutex_unlock_impl error would be replaced by this assertion
>> failing).
>>
>
> You are right. Trying your example given in v4:
>
> $ touch /tmp/iothread-create-test.qcow2
> $ ./qemu-system-x86_64 -object iothread,id=iothr0 -qmp stdio <<EOF
> {"execute": "qmp_capabilities"}
> {"execute":"blockdev-add","arguments":{"node-name":"proto","driver":"file","filename":"/tmp/iothread-create-test.qcow2"}}
>
> {"execute":"x-blockdev-set-iothread","arguments":{"node-name":"proto","iothread":"iothr0"}}
>
> {"execute":"blockdev-create","arguments":{"job-id":"create","options":{"driver":"qcow2","file":"proto","size":0}}}
>
> EOF
>
> I still get "qemu_mutex_unlock_impl: Operation not permitted"
>
> I will remove the comment above the assertion, makes no sense.
>
> Or should I replace it with a TODO/FIXME explaining the above?
> Something like:
>
> /*
> * TODO: it is currently possible to run a blockdev-create job in an
> * I/O thread, for example by doing:
> * [ command line above ]
> * This should not be allowed.
> */
Just removing it makes the most sense to me. We already have a TODO
comment to that effect (block/create.c:86).
(And to be precise, it is *not* possible to run a blockdev-create job in
an I/O thread, it’s always run in the main thread. It is possible to
run a blockdev-create job involving nodes in I/O threads, and it’s fine
that that’s possible, but in such cases the block drivers’
.bdrv_co_create() implementations should at least error out with a
benign error, which they don’t.)
Hanna
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 28/31] block.c: assert BQL lock held in bdrv_co_invalidate_cache
2021-12-17 11:04 ` Hanna Reitz
@ 2021-12-17 16:38 ` Emanuele Giuseppe Esposito
2021-12-20 12:20 ` Emanuele Giuseppe Esposito
0 siblings, 1 reply; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-12-17 16:38 UTC (permalink / raw)
To: Hanna Reitz, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 17/12/2021 12:04, Hanna Reitz wrote:
> On 24.11.21 07:44, Emanuele Giuseppe Esposito wrote:
>> bdrv_co_invalidate_cache is special: it is an I/O function,
>
> I still don’t believe it is, but well.
>
> (Yes, it is called by a test in an iothread, but I believe we’ve seen
> that the tests simply sometimes test things that shouldn’t be allowed.)
>
>> but uses the block layer permission API, which is GS.
>>
>> Because of this, we can assert that either the function is
>> being called with BQL held, and thus can use the permission API,
>> or make sure that the permission API is not used, by ensuring that
>> bs (and parents) .open_flags does not contain BDRV_O_INACTIVE.
>>
>> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
>> ---
>> block.c | 26 ++++++++++++++++++++++++++
>> 1 file changed, 26 insertions(+)
>>
>> diff --git a/block.c b/block.c
>> index a0309f827d..805974676b 100644
>> --- a/block.c
>> +++ b/block.c
>> @@ -6574,6 +6574,26 @@ void bdrv_init_with_whitelist(void)
>> bdrv_init();
>> }
>> +static bool bdrv_is_active(BlockDriverState *bs)
>> +{
>> + BdrvChild *parent;
>> +
>> + if (bs->open_flags & BDRV_O_INACTIVE) {
>> + return false;
>> + }
>> +
>> + QLIST_FOREACH(parent, &bs->parents, next_parent) {
>> + if (parent->klass->parent_is_bds) {
>> + BlockDriverState *parent_bs = parent->opaque;
>
> This looks like a really bad hack to me. We purposefully have made the
> parent link opaque so that a BDS cannot easily reach its parents. All
> accesses should go through BdrvChildClass methods.
>
> I also don’t understand why we need to query parents at all. The only
> fact that determines whether the current BDS will have its permissions
> changed is whether the BDS itself is active or inactive. Sure, we’ll
> invoke bdrv_co_invalidate_cache() on the parents, too, but then we could
> simply let the assertion fail there.
>
>> + if (!bdrv_is_active(parent_bs)) {
>> + return false;
>> + }
>> + }
>> + }
>> +
>> + return true;
>> +}
>> +
>> int coroutine_fn bdrv_co_invalidate_cache(BlockDriverState *bs,
>> Error **errp)
>> {
>> BdrvChild *child, *parent;
>> @@ -6585,6 +6605,12 @@ int coroutine_fn
>> bdrv_co_invalidate_cache(BlockDriverState *bs, Error **errp)
>> return -ENOMEDIUM;
>> }
>> + /*
>> + * No need to muck with permissions if bs is active.
>> + * TODO: should activation be a separate function?
>> + */
>> + assert(qemu_in_main_thread() || bdrv_is_active(bs));
>> +
>
> I don’t understand this, really. It looks to me like “if you don’t call
> this in the main thread, this better be a no-op”, i.e., you must never
> call this function in an I/O thread if you really want to use it. I.e.
> what I’d classify as a GS function.
>
> It sounds like this is just a special case for said test, and
> special-casing code for tests sounds like a bad idea.
Ok, but trying to leave just the qemu_in_main_thread() assertion makes
test 307 (./check 307) fail.
I am actually not sure on why it fails, but I am sure it is because of
the assertion, since without it it passes.
I tried with gdb (./check -gdb 307 on one terminal and
gdb -iex "target remote localhost:12345"
in another) but it points me to this below, which I think is the ndb
server getting the socket closed (because on the other side it crashed),
and not the actual error.
Thread 1 "qemu-system-x86" received signal SIGPIPE, Broken pipe.
0x00007ffff68af54d in sendmsg () from target:/lib64/libc.so.6
(gdb) bt
#0 0x00007ffff68af54d in sendmsg () from target:/lib64/libc.so.6
#1 0x0000555555c13cc9 in qio_channel_socket_writev (ioc=<optimized
out>, iov=0x5555569a4870, niov=1, fds=0x0, nfds=<optimized out>, errp=0x0)
at ../io/channel-socket.c:561
#2 0x0000555555c19b18 in qio_channel_writev_full_all
(ioc=0x55555763b800, iov=iov@entry=0x7fffe8dffd80, niov=niov@entry=1,
fds=fds@entry=0x0,
nfds=nfds@entry=0, errp=errp@entry=0x0) at ../io/channel.c:240
#3 0x0000555555c19bd2 in qio_channel_writev_all (errp=0x0, niov=1,
iov=0x7fffe8dffd80, ioc=<optimized out>) at ../io/channel.c:220
#4 qio_channel_write_all (ioc=<optimized out>,
buf=buf@entry=0x7fffe8dffdd0 "", buflen=buflen@entry=20,
errp=errp@entry=0x0) at ../io/channel.c:330
#5 0x0000555555c27e75 in nbd_write (errp=0x0, size=20,
buffer=0x7fffe8dffdd0, ioc=<optimized out>) at ../nbd/nbd-internal.h:71
#6 nbd_negotiate_send_rep_len (client=client@entry=0x555556f60930,
type=type@entry=1, len=len@entry=0, errp=errp@entry=0x0) at
../nbd/server.c:203
#7 0x0000555555c29db1 in nbd_negotiate_send_rep (errp=0x0, type=1,
client=0x555556f60930) at ../nbd/server.c:211
--Type <RET> for more, q to quit, c to continue without paging--
#8 nbd_negotiate_options (errp=0x7fffe8dffe88, client=<optimized out>)
at ../nbd/server.c:1224
#9 nbd_negotiate (errp=0x7fffe8dffe88, client=<optimized out>) at
../nbd/server.c:1340
#10 nbd_co_client_start (opaque=<optimized out>) at ../nbd/server.c:2715
#11 0x0000555555d70423 in coroutine_trampoline (i0=<optimized out>,
i1=<optimized out>) at ../util/coroutine-ucontext.c:173
#12 0x00007ffff67f3820 in ?? () from target:/lib64/libc.so.6
#13 0x00007fffffffca80 in ?? ()
Emanuele
>
> Hanna
>
>> QLIST_FOREACH(child, &bs->children, next) {
>> bdrv_co_invalidate_cache(child->bs, &local_err);
>> if (local_err) {
>
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 28/31] block.c: assert BQL lock held in bdrv_co_invalidate_cache
2021-12-17 16:38 ` Emanuele Giuseppe Esposito
@ 2021-12-20 12:20 ` Emanuele Giuseppe Esposito
2021-12-23 17:11 ` Hanna Reitz
2022-01-19 18:34 ` Kevin Wolf
0 siblings, 2 replies; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-12-20 12:20 UTC (permalink / raw)
To: Hanna Reitz, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 17/12/2021 17:38, Emanuele Giuseppe Esposito wrote:
>
>
> On 17/12/2021 12:04, Hanna Reitz wrote:
>> On 24.11.21 07:44, Emanuele Giuseppe Esposito wrote:
>>> bdrv_co_invalidate_cache is special: it is an I/O function,
>>
>> I still don’t believe it is, but well.
>>
>> (Yes, it is called by a test in an iothread, but I believe we’ve seen
>> that the tests simply sometimes test things that shouldn’t be allowed.)
>>
>>> but uses the block layer permission API, which is GS.
>>>
>>> Because of this, we can assert that either the function is
>>> being called with BQL held, and thus can use the permission API,
>>> or make sure that the permission API is not used, by ensuring that
>>> bs (and parents) .open_flags does not contain BDRV_O_INACTIVE.
>>>
>>> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
>>> ---
>>> block.c | 26 ++++++++++++++++++++++++++
>>> 1 file changed, 26 insertions(+)
>>>
>>> diff --git a/block.c b/block.c
>>> index a0309f827d..805974676b 100644
>>> --- a/block.c
>>> +++ b/block.c
>>> @@ -6574,6 +6574,26 @@ void bdrv_init_with_whitelist(void)
>>> bdrv_init();
>>> }
>>> +static bool bdrv_is_active(BlockDriverState *bs)
>>> +{
>>> + BdrvChild *parent;
>>> +
>>> + if (bs->open_flags & BDRV_O_INACTIVE) {
>>> + return false;
>>> + }
>>> +
>>> + QLIST_FOREACH(parent, &bs->parents, next_parent) {
>>> + if (parent->klass->parent_is_bds) {
>>> + BlockDriverState *parent_bs = parent->opaque;
>>
>> This looks like a really bad hack to me. We purposefully have made
>> the parent link opaque so that a BDS cannot easily reach its parents.
>> All accesses should go through BdrvChildClass methods.
>>
>> I also don’t understand why we need to query parents at all. The only
>> fact that determines whether the current BDS will have its permissions
>> changed is whether the BDS itself is active or inactive. Sure, we’ll
>> invoke bdrv_co_invalidate_cache() on the parents, too, but then we
>> could simply let the assertion fail there.
>>
>>> + if (!bdrv_is_active(parent_bs)) {
>>> + return false;
>>> + }
>>> + }
>>> + }
>>> +
>>> + return true;
>>> +}
>>> +
>>> int coroutine_fn bdrv_co_invalidate_cache(BlockDriverState *bs,
>>> Error **errp)
>>> {
>>> BdrvChild *child, *parent;
>>> @@ -6585,6 +6605,12 @@ int coroutine_fn
>>> bdrv_co_invalidate_cache(BlockDriverState *bs, Error **errp)
>>> return -ENOMEDIUM;
>>> }
>>> + /*
>>> + * No need to muck with permissions if bs is active.
>>> + * TODO: should activation be a separate function?
>>> + */
>>> + assert(qemu_in_main_thread() || bdrv_is_active(bs));
>>> +
>>
>> I don’t understand this, really. It looks to me like “if you don’t
>> call this in the main thread, this better be a no-op”, i.e., you must
>> never call this function in an I/O thread if you really want to use
>> it. I.e. what I’d classify as a GS function.
>>
>> It sounds like this is just a special case for said test, and
>> special-casing code for tests sounds like a bad idea.
>
> Ok, but trying to leave just the qemu_in_main_thread() assertion makes
> test 307 (./check 307) fail.
> I am actually not sure on why it fails, but I am sure it is because of
> the assertion, since without it it passes.
>
> I tried with gdb (./check -gdb 307 on one terminal and
> gdb -iex "target remote localhost:12345"
> in another) but it points me to this below, which I think is the ndb
> server getting the socket closed (because on the other side it crashed),
> and not the actual error.
>
>
> Thread 1 "qemu-system-x86" received signal SIGPIPE, Broken pipe.
> 0x00007ffff68af54d in sendmsg () from target:/lib64/libc.so.6
> (gdb) bt
> #0 0x00007ffff68af54d in sendmsg () from target:/lib64/libc.so.6
> #1 0x0000555555c13cc9 in qio_channel_socket_writev (ioc=<optimized
> out>, iov=0x5555569a4870, niov=1, fds=0x0, nfds=<optimized out>, errp=0x0)
> at ../io/channel-socket.c:561
> #2 0x0000555555c19b18 in qio_channel_writev_full_all
> (ioc=0x55555763b800, iov=iov@entry=0x7fffe8dffd80, niov=niov@entry=1,
> fds=fds@entry=0x0,
> nfds=nfds@entry=0, errp=errp@entry=0x0) at ../io/channel.c:240
> #3 0x0000555555c19bd2 in qio_channel_writev_all (errp=0x0, niov=1,
> iov=0x7fffe8dffd80, ioc=<optimized out>) at ../io/channel.c:220
> #4 qio_channel_write_all (ioc=<optimized out>,
> buf=buf@entry=0x7fffe8dffdd0 "", buflen=buflen@entry=20,
> errp=errp@entry=0x0) at ../io/channel.c:330
> #5 0x0000555555c27e75 in nbd_write (errp=0x0, size=20,
> buffer=0x7fffe8dffdd0, ioc=<optimized out>) at ../nbd/nbd-internal.h:71
> #6 nbd_negotiate_send_rep_len (client=client@entry=0x555556f60930,
> type=type@entry=1, len=len@entry=0, errp=errp@entry=0x0) at
> ../nbd/server.c:203
> #7 0x0000555555c29db1 in nbd_negotiate_send_rep (errp=0x0, type=1,
> client=0x555556f60930) at ../nbd/server.c:211
> --Type <RET> for more, q to quit, c to continue without paging--
> #8 nbd_negotiate_options (errp=0x7fffe8dffe88, client=<optimized out>)
> at ../nbd/server.c:1224
> #9 nbd_negotiate (errp=0x7fffe8dffe88, client=<optimized out>) at
> ../nbd/server.c:1340
> #10 nbd_co_client_start (opaque=<optimized out>) at ../nbd/server.c:2715
> #11 0x0000555555d70423 in coroutine_trampoline (i0=<optimized out>,
> i1=<optimized out>) at ../util/coroutine-ucontext.c:173
> #12 0x00007ffff67f3820 in ?? () from target:/lib64/libc.so.6
> #13 0x00007fffffffca80 in ?? ()
>
Ok the reason for this is line 89 of tests/qemu-iotests/307:
# Should ignore the iothread conflict, but then fail because of the
# permission conflict (and not crash)
vm.qmp_log('block-export-add', id='export1', type='nbd', node_name='null',
iothread='iothread1', fixed_iothread=False, writable=True)
This calls qmp_block_export_add() and then blk_exp_add(), that calls
bdrv_invalidate_cache().
Both functions are running in the main thread, but then
bdrv_invalidate_cache invokes bdrv_co_invalidate_cache() as a coroutine
in the AioContext of the given bs, so not the main loop.
So Hanna, what should we do here? This seems very similar to the
discussion in patch 22, ie run blockdev-create (in this case
block-export-add, which seems similar?) involving nodes in I/O threads.
Thank you,
Emanuele
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 30/31] crypto: delegate permission functions to JobDriver .pre_run
2021-12-17 12:29 ` Hanna Reitz
2021-12-17 14:32 ` Hanna Reitz
@ 2021-12-20 15:47 ` Emanuele Giuseppe Esposito
2021-12-23 17:15 ` Hanna Reitz
1 sibling, 1 reply; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2021-12-20 15:47 UTC (permalink / raw)
To: Hanna Reitz, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 17/12/2021 13:29, Hanna Reitz wrote:
> On 24.11.21 07:44, Emanuele Giuseppe Esposito wrote:
>> block_crypto_amend_options_generic_luks uses the block layer
>> permission API, therefore it should be called with the BQL held.
>>
>> However, the same function is being called ib two BlockDriver
>
> s/ ib / by /
>
>> callbacks: bdrv_amend_options (under BQL) and bdrv_co_amend (I/O).
>>
>> The latter is I/O because it is invoked by block/amend.c's
>> blockdev_amend_run(), a .run callback of the amend JobDriver
>>
>> Therefore we want to 1) change block_crypto_amend_options_generic_luks
>> to use the permission API only when the BQL is held, and
>> 2) use the .pre_run JobDriver callback to check for
>> permissions before switching to the job aiocontext. This has also
>> the benefit of applying the same permission operation to all
>> amend implementations, not only luks.
>>
>> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
>> ---
>> block/amend.c | 20 ++++++++++++++++++++
>> block/crypto.c | 18 ++++++++++++------
>> 2 files changed, 32 insertions(+), 6 deletions(-)
>>
>> diff --git a/block/amend.c b/block/amend.c
>> index 392df9ef83..fba6add51a 100644
>> --- a/block/amend.c
>> +++ b/block/amend.c
>> @@ -53,10 +53,30 @@ static int coroutine_fn blockdev_amend_run(Job
>> *job, Error **errp)
>> return ret;
>> }
>> +static int blockdev_amend_refresh_perms(Job *job, Error **errp)
>> +{
>> + BlockdevAmendJob *s = container_of(job, BlockdevAmendJob, common);
>> +
>> + return bdrv_child_refresh_perms(s->bs, s->bs->file, errp);
>> +}
>
> I miss some documentation for this function, why we do it and how it
> works together with the bdrv_co_amend implementation.
>
> I was trying to come up with an example text, but then I wondered – how
> does it actually work? bdrv_child_refresh_perms() eventually ends up in
> block_crypto_child_perms(). However, that will only return exceptional
> permissions if crypto->updating_keys is true. But that’s set only in
> block_crypto_amend_options_generic_luks() – i.e. when the job runs.
> That’s exactly why that function calls bdrv_child_refresh_perms() only
> after it has modified crypto->updating_keys.
>
> Reproducer (amend on a LUKS image with read-only=true, so it doesn’t
> have the WRITE permission continuously, but needs to take it as an
> exception in block_crypto_child_perms()):
>
> $ qemu-img create \
> -f luks \
> --object secret,id=sec0,data=123456 \
> -o key-secret=sec0 \
> test.luks \
> 64M
> Formatting 'test.luks', fmt=luks size=67108864 key-secret=sec0
>
> $ ./qemu-system-x86_64 \
> -object secret,id=sec0,data=123456 \
> -object iothread,id=iothr0 \
> -blockdev file,node-name=node0,filename=test.luks \
> -blockdev
> luks,node-name=node1,key-secret=sec0,file=node0,read-only=true \
> -device virtio-blk,drive=node1,iothread=iothr0 -qmp stdio \
> <<EOF
> {"execute": "qmp_capabilities"}
> {
> "execute": "x-blockdev-amend",
> "arguments": {
> "job-id": "amend0",
> "node-name": "node1",
> "options": {
> "driver": "luks",
> "state": "active",
> "new-secret": "sec0"
> }
> }
> }
> EOF
>
> {"QMP": {"version": {"qemu": {"micro": 93, "minor": 1, "major": 6},
> "package": "v6.2.0-rc3-50-gdb635fc4e7"}, "capabilities": ["oob"]}}
> {"return": {}}
> {"timestamp": {"seconds": 1639742600, "microseconds": 574641}, "event":
> "JOB_STATUS_CHANGE", "data": {"status": "created", "id": "amend0"}}
> {"timestamp": {"seconds": 1639742600, "microseconds": 574919}, "event":
> "JOB_STATUS_CHANGE", "data": {"status": "running", "id": "amend0"}}
> {"return": {}}
> qemu-system-x86_64: ../block/io.c:2041: bdrv_co_write_req_prepare:
> Assertion `child->perm & BLK_PERM_WRITE' failed.
> [1] 55880 IOT instruction (core dumped) ./qemu-system-x86_64 -object
> secret,id=sec0,data=123456 -object -blockdev
>
>
> I believe this means we need some new block driver function to prepare
> for an amendment operation. If so, another question comes up, which is
> whether this preparatory function should then also call
> bdrv_child_refresh_perms(), and then whether we should have a clean-up
> function for symmetry.
>
Yes, unfortunately it means that (see at the end of the mail for more).
I think it does not work because of crypto->updating_keys missing in
blockdev_amend_pre_run(). That is why the permission is not correctly
set and the example fails.
>> +
>> +static int blockdev_amend_pre_run(Job *job, Error **errp)
>> +{
>> + return blockdev_amend_refresh_perms(job, errp);
>> +}
>> +
>> +static void blockdev_amend_clean(Job *job)
>> +{
>> + Error *errp;
>> + blockdev_amend_refresh_perms(job, &errp);
>
> Do we really want to ignore this error? If so, we shouldn’t pass a
> pointer to an unused local variable, but NULL.
>
> If we don’t want to ignore it, we have the option of doing what you do
> here and then at least reporting a potential error with
> error_report_err(), and then freeing it, and we also must initialize
> errp to NULL in this case.
Going with this one above, thanks.
>
> If we expect no error to happen (e.g. because we require the amend
> implementation to only release/share permissions and not acquire/unshare
> them), then I’d expect passing &error_abort here.
>
>> +}
>> +
>> static const JobDriver blockdev_amend_job_driver = {
>> .instance_size = sizeof(BlockdevAmendJob),
>> .job_type = JOB_TYPE_AMEND,
>> .run = blockdev_amend_run,
>> + .pre_run = blockdev_amend_pre_run,
>> + .clean = blockdev_amend_clean,
>> };
>> void qmp_x_blockdev_amend(const char *job_id,
>> diff --git a/block/crypto.c b/block/crypto.c
>> index c8ba4681e2..82f154516c 100644
>> --- a/block/crypto.c
>> +++ b/block/crypto.c
>> @@ -780,6 +780,7 @@
>> block_crypto_get_specific_info_luks(BlockDriverState *bs, Error **errp)
>> static int
>> block_crypto_amend_options_generic_luks(BlockDriverState *bs,
>> QCryptoBlockAmendOptions
>> *amend_options,
>> + bool under_bql,
>
> This name makes sense in the context of this series, but not so much
> outside of it.
>
> I’d rename it to e.g. “in_amend_job” (and invert its value), and then
> explain that we don’t need to refresh the child permissions when running
> in an amend job, because that job has already taken care of that.
>
> OTOH, given that I believe we need some separate preparatory function
> anyway, perhaps we should just pull out the bdrv_child_refresh_perms()
> from this function altogether, so that we have:
>
> block_crypto_amend_options_luks():
>
> /* sets updating_keys to true, and invokes bdrv_child_refresh_perms() */
> block_crypto_amend_options_prepare();
> block_crypto_amend_options_generic_luks();
> /* sets updating_keys to false, and invokes bdrv_child_refresh_perms() */
> block_crypto_amend_options_clean();
>
>
> block_crypto_co_amend_luks():
>
> /* No need to prepare or clean up, that is taken care of by the amend
> job */
> block_crypto_amend_options_generic_luks();
>
>
> (If we decide not to put bdrv_child_refresh_perms() into
> prepare()/clean(), then it would need to be called by
> block_crypto_amend_options_luks(); and if we decide not to have a
> block_crypto_amend_options_clean(), then we’d need to inline it fully.)
So a couple of things I will change (according with your feedbacks):
- Remove the assertion job->aio_context == qemu_in_main_thread() done in
job_co_entry, as it is wrong. I don't know why I added that, but we
cannot assume that job->run() always run in the main context, because
the job aiocontext can be different. I don't think there is a test doing
that now, but it is possible. If run() was in the main context, then
bdrv_co_amend (called only in blockdev_amend_run) would be GS too, but
it isn't, also according with your comment in v4:
"[...] .bdrv_co_amend very much strikes me like a GS function, but
it isn’t. I’m afraid it must work on nodes that are not in the main
context, and it launches a job, so AFAIU we absolutely cannot run it
under the BQL."
- Introduce block_crypto_amend_options_prepare and
block_crypto_amend_options_clean, as you suggested above. These fix the
GS call stack of block_crypto_amend_options_generic_luks()
- Introduce .bdrv_pre_run() and .bdrv_cleanup(), respectively called by
.job_pre_run() and .job_cleanup(). The reason is that we need to set
crypto->updating_keys, otherwise the job amend won't temporary give the
write permission so the example above would fail.
So for the I/O callstack of block_crypto_amend_options_generic_luks() we
will have:
job->pre_run():
.bdrv_pre_run();
crypto->update_keys = true;
blockdev_amend_refresh_perms()
job->run():
block_crypto_amend_options_generic_luks()
job->cleanup():
.bdrv_cleanup();
crypto->update_keys = false;
blockdev_amend_refresh_perms()
Thank you,
Emanuele
>
> Hanna
>
>> bool force,
>> Error **errp)
>> {
>> @@ -791,9 +792,12 @@
>> block_crypto_amend_options_generic_luks(BlockDriverState *bs,
>> /* apply for exclusive read/write permissions to the underlying
>> file*/
>> crypto->updating_keys = true;
>> - ret = bdrv_child_refresh_perms(bs, bs->file, errp);
>> - if (ret) {
>> - goto cleanup;
>> +
>> + if (under_bql) {
>> + ret = bdrv_child_refresh_perms(bs, bs->file, errp);
>> + if (ret) {
>> + goto cleanup;
>> + }
>> }
>> ret = qcrypto_block_amend_options(crypto->block,
>> @@ -806,7 +810,9 @@
>> block_crypto_amend_options_generic_luks(BlockDriverState *bs,
>> cleanup:
>> /* release exclusive read/write permissions to the underlying
>> file*/
>> crypto->updating_keys = false;
>> - bdrv_child_refresh_perms(bs, bs->file, errp);
>> + if (under_bql) {
>> + bdrv_child_refresh_perms(bs, bs->file, errp);
>> + }
>> return ret;
>> }
>> @@ -834,7 +840,7 @@ block_crypto_amend_options_luks(BlockDriverState *bs,
>> goto cleanup;
>> }
>> ret = block_crypto_amend_options_generic_luks(bs, amend_options,
>> - force, errp);
>> + true, force, errp);
>> cleanup:
>> qapi_free_QCryptoBlockAmendOptions(amend_options);
>> return ret;
>> @@ -853,7 +859,7 @@ coroutine_fn
>> block_crypto_co_amend_luks(BlockDriverState *bs,
>> .u.luks = *qapi_BlockdevAmendOptionsLUKS_base(&opts->u.luks),
>> };
>> return block_crypto_amend_options_generic_luks(bs, &amend_opts,
>> - force, errp);
>> + false, force, errp);
>> }
>> static void
>
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 28/31] block.c: assert BQL lock held in bdrv_co_invalidate_cache
2021-12-20 12:20 ` Emanuele Giuseppe Esposito
@ 2021-12-23 17:11 ` Hanna Reitz
2022-01-19 15:57 ` Hanna Reitz
2022-01-19 18:34 ` Kevin Wolf
1 sibling, 1 reply; 66+ messages in thread
From: Hanna Reitz @ 2021-12-23 17:11 UTC (permalink / raw)
To: Emanuele Giuseppe Esposito, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 20.12.21 13:20, Emanuele Giuseppe Esposito wrote:
>
>
> On 17/12/2021 17:38, Emanuele Giuseppe Esposito wrote:
>>
>>
>> On 17/12/2021 12:04, Hanna Reitz wrote:
>>> On 24.11.21 07:44, Emanuele Giuseppe Esposito wrote:
>>>> bdrv_co_invalidate_cache is special: it is an I/O function,
>>>
>>> I still don’t believe it is, but well.
>>>
>>> (Yes, it is called by a test in an iothread, but I believe we’ve
>>> seen that the tests simply sometimes test things that shouldn’t be
>>> allowed.)
>>>
>>>> but uses the block layer permission API, which is GS.
>>>>
>>>> Because of this, we can assert that either the function is
>>>> being called with BQL held, and thus can use the permission API,
>>>> or make sure that the permission API is not used, by ensuring that
>>>> bs (and parents) .open_flags does not contain BDRV_O_INACTIVE.
>>>>
>>>> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
>>>> ---
>>>> block.c | 26 ++++++++++++++++++++++++++
>>>> 1 file changed, 26 insertions(+)
>>>>
>>>> diff --git a/block.c b/block.c
>>>> index a0309f827d..805974676b 100644
>>>> --- a/block.c
>>>> +++ b/block.c
>>>> @@ -6574,6 +6574,26 @@ void bdrv_init_with_whitelist(void)
>>>> bdrv_init();
>>>> }
>>>> +static bool bdrv_is_active(BlockDriverState *bs)
>>>> +{
>>>> + BdrvChild *parent;
>>>> +
>>>> + if (bs->open_flags & BDRV_O_INACTIVE) {
>>>> + return false;
>>>> + }
>>>> +
>>>> + QLIST_FOREACH(parent, &bs->parents, next_parent) {
>>>> + if (parent->klass->parent_is_bds) {
>>>> + BlockDriverState *parent_bs = parent->opaque;
>>>
>>> This looks like a really bad hack to me. We purposefully have made
>>> the parent link opaque so that a BDS cannot easily reach its
>>> parents. All accesses should go through BdrvChildClass methods.
>>>
>>> I also don’t understand why we need to query parents at all. The
>>> only fact that determines whether the current BDS will have its
>>> permissions changed is whether the BDS itself is active or
>>> inactive. Sure, we’ll invoke bdrv_co_invalidate_cache() on the
>>> parents, too, but then we could simply let the assertion fail there.
>>>
>>>> + if (!bdrv_is_active(parent_bs)) {
>>>> + return false;
>>>> + }
>>>> + }
>>>> + }
>>>> +
>>>> + return true;
>>>> +}
>>>> +
>>>> int coroutine_fn bdrv_co_invalidate_cache(BlockDriverState *bs,
>>>> Error **errp)
>>>> {
>>>> BdrvChild *child, *parent;
>>>> @@ -6585,6 +6605,12 @@ int coroutine_fn
>>>> bdrv_co_invalidate_cache(BlockDriverState *bs, Error **errp)
>>>> return -ENOMEDIUM;
>>>> }
>>>> + /*
>>>> + * No need to muck with permissions if bs is active.
>>>> + * TODO: should activation be a separate function?
>>>> + */
>>>> + assert(qemu_in_main_thread() || bdrv_is_active(bs));
>>>> +
>>>
>>> I don’t understand this, really. It looks to me like “if you don’t
>>> call this in the main thread, this better be a no-op”, i.e., you
>>> must never call this function in an I/O thread if you really want to
>>> use it. I.e. what I’d classify as a GS function.
>>>
>>> It sounds like this is just a special case for said test, and
>>> special-casing code for tests sounds like a bad idea.
>>
>> Ok, but trying to leave just the qemu_in_main_thread() assertion
>> makes test 307 (./check 307) fail.
>> I am actually not sure on why it fails, but I am sure it is because
>> of the assertion, since without it it passes.
>>
>> I tried with gdb (./check -gdb 307 on one terminal and
>> gdb -iex "target remote localhost:12345"
>> in another) but it points me to this below, which I think is the ndb
>> server getting the socket closed (because on the other side it
>> crashed), and not the actual error.
>>
>>
>> Thread 1 "qemu-system-x86" received signal SIGPIPE, Broken pipe.
>> 0x00007ffff68af54d in sendmsg () from target:/lib64/libc.so.6
>> (gdb) bt
>> #0 0x00007ffff68af54d in sendmsg () from target:/lib64/libc.so.6
>> #1 0x0000555555c13cc9 in qio_channel_socket_writev (ioc=<optimized
>> out>, iov=0x5555569a4870, niov=1, fds=0x0, nfds=<optimized out>,
>> errp=0x0)
>> at ../io/channel-socket.c:561
>> #2 0x0000555555c19b18 in qio_channel_writev_full_all
>> (ioc=0x55555763b800, iov=iov@entry=0x7fffe8dffd80, niov=niov@entry=1,
>> fds=fds@entry=0x0,
>> nfds=nfds@entry=0, errp=errp@entry=0x0) at ../io/channel.c:240
>> #3 0x0000555555c19bd2 in qio_channel_writev_all (errp=0x0, niov=1,
>> iov=0x7fffe8dffd80, ioc=<optimized out>) at ../io/channel.c:220
>> #4 qio_channel_write_all (ioc=<optimized out>,
>> buf=buf@entry=0x7fffe8dffdd0 "", buflen=buflen@entry=20,
>> errp=errp@entry=0x0) at ../io/channel.c:330
>> #5 0x0000555555c27e75 in nbd_write (errp=0x0, size=20,
>> buffer=0x7fffe8dffdd0, ioc=<optimized out>) at ../nbd/nbd-internal.h:71
>> #6 nbd_negotiate_send_rep_len (client=client@entry=0x555556f60930,
>> type=type@entry=1, len=len@entry=0, errp=errp@entry=0x0) at
>> ../nbd/server.c:203
>> #7 0x0000555555c29db1 in nbd_negotiate_send_rep (errp=0x0, type=1,
>> client=0x555556f60930) at ../nbd/server.c:211
>> --Type <RET> for more, q to quit, c to continue without paging--
>> #8 nbd_negotiate_options (errp=0x7fffe8dffe88, client=<optimized
>> out>) at ../nbd/server.c:1224
>> #9 nbd_negotiate (errp=0x7fffe8dffe88, client=<optimized out>) at
>> ../nbd/server.c:1340
>> #10 nbd_co_client_start (opaque=<optimized out>) at ../nbd/server.c:2715
>> #11 0x0000555555d70423 in coroutine_trampoline (i0=<optimized out>,
>> i1=<optimized out>) at ../util/coroutine-ucontext.c:173
>> #12 0x00007ffff67f3820 in ?? () from target:/lib64/libc.so.6
>> #13 0x00007fffffffca80 in ?? ()
>>
>
> Ok the reason for this is line 89 of tests/qemu-iotests/307:
>
> # Should ignore the iothread conflict, but then fail because of the
> # permission conflict (and not crash)
> vm.qmp_log('block-export-add', id='export1', type='nbd',
> node_name='null',
> iothread='iothread1', fixed_iothread=False, writable=True)
>
> This calls qmp_block_export_add() and then blk_exp_add(), that calls
> bdrv_invalidate_cache().
> Both functions are running in the main thread, but then
> bdrv_invalidate_cache invokes bdrv_co_invalidate_cache() as a
> coroutine in the AioContext of the given bs, so not the main loop.
>
> So Hanna, what should we do here? This seems very similar to the
> discussion in patch 22, ie run blockdev-create (in this case
> block-export-add, which seems similar?) involving nodes in I/O threads.
Honestly, I’m still thinking about this and haven’t come to a
conclusion. It doesn’t seem invalid to run bdrv_co_invalidate_cache()
in the context of the BDS here, but then the assertion that the BDS is
already active seems kind of just lucky to work.
I plan to look into whether I can reproduce some case where the
assertion doesn’t hold (thinking of migration with a block device in an
iothread), and then see what I learn from this. :/
Hanna
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 30/31] crypto: delegate permission functions to JobDriver .pre_run
2021-12-20 15:47 ` Emanuele Giuseppe Esposito
@ 2021-12-23 17:15 ` Hanna Reitz
0 siblings, 0 replies; 66+ messages in thread
From: Hanna Reitz @ 2021-12-23 17:15 UTC (permalink / raw)
To: Emanuele Giuseppe Esposito, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 20.12.21 16:47, Emanuele Giuseppe Esposito wrote:
>
>
> On 17/12/2021 13:29, Hanna Reitz wrote:
>> On 24.11.21 07:44, Emanuele Giuseppe Esposito wrote:
>>> block_crypto_amend_options_generic_luks uses the block layer
>>> permission API, therefore it should be called with the BQL held.
>>>
>>> However, the same function is being called ib two BlockDriver
>>
>> s/ ib / by /
>>
>>> callbacks: bdrv_amend_options (under BQL) and bdrv_co_amend (I/O).
>>>
>>> The latter is I/O because it is invoked by block/amend.c's
>>> blockdev_amend_run(), a .run callback of the amend JobDriver
>>>
>>> Therefore we want to 1) change block_crypto_amend_options_generic_luks
>>> to use the permission API only when the BQL is held, and
>>> 2) use the .pre_run JobDriver callback to check for
>>> permissions before switching to the job aiocontext. This has also
>>> the benefit of applying the same permission operation to all
>>> amend implementations, not only luks.
>>>
>>> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
>>> ---
>>> block/amend.c | 20 ++++++++++++++++++++
>>> block/crypto.c | 18 ++++++++++++------
>>> 2 files changed, 32 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/block/amend.c b/block/amend.c
>>> index 392df9ef83..fba6add51a 100644
>>> --- a/block/amend.c
>>> +++ b/block/amend.c
>>> @@ -53,10 +53,30 @@ static int coroutine_fn blockdev_amend_run(Job
>>> *job, Error **errp)
>>> return ret;
>>> }
>>> +static int blockdev_amend_refresh_perms(Job *job, Error **errp)
>>> +{
>>> + BlockdevAmendJob *s = container_of(job, BlockdevAmendJob, common);
>>> +
>>> + return bdrv_child_refresh_perms(s->bs, s->bs->file, errp);
>>> +}
>>
>> I miss some documentation for this function, why we do it and how it
>> works together with the bdrv_co_amend implementation.
>
>>
>> I was trying to come up with an example text, but then I wondered –
>> how does it actually work? bdrv_child_refresh_perms() eventually ends
>> up in block_crypto_child_perms(). However, that will only return
>> exceptional permissions if crypto->updating_keys is true. But that’s
>> set only in block_crypto_amend_options_generic_luks() – i.e. when the
>> job runs. That’s exactly why that function calls
>> bdrv_child_refresh_perms() only after it has modified
>> crypto->updating_keys.
>>
>> Reproducer (amend on a LUKS image with read-only=true, so it doesn’t
>> have the WRITE permission continuously, but needs to take it as an
>> exception in block_crypto_child_perms()):
>>
>> $ qemu-img create \
>> -f luks \
>> --object secret,id=sec0,data=123456 \
>> -o key-secret=sec0 \
>> test.luks \
>> 64M
>> Formatting 'test.luks', fmt=luks size=67108864 key-secret=sec0
>>
>> $ ./qemu-system-x86_64 \
>> -object secret,id=sec0,data=123456 \
>> -object iothread,id=iothr0 \
>> -blockdev file,node-name=node0,filename=test.luks \
>> -blockdev
>> luks,node-name=node1,key-secret=sec0,file=node0,read-only=true \
>> -device virtio-blk,drive=node1,iothread=iothr0 -qmp stdio \
>> <<EOF
>> {"execute": "qmp_capabilities"}
>> {
>> "execute": "x-blockdev-amend",
>> "arguments": {
>> "job-id": "amend0",
>> "node-name": "node1",
>> "options": {
>> "driver": "luks",
>> "state": "active",
>> "new-secret": "sec0"
>> }
>> }
>> }
>> EOF
>>
>> {"QMP": {"version": {"qemu": {"micro": 93, "minor": 1, "major": 6},
>> "package": "v6.2.0-rc3-50-gdb635fc4e7"}, "capabilities": ["oob"]}}
>> {"return": {}}
>> {"timestamp": {"seconds": 1639742600, "microseconds": 574641},
>> "event": "JOB_STATUS_CHANGE", "data": {"status": "created", "id":
>> "amend0"}}
>> {"timestamp": {"seconds": 1639742600, "microseconds": 574919},
>> "event": "JOB_STATUS_CHANGE", "data": {"status": "running", "id":
>> "amend0"}}
>> {"return": {}}
>> qemu-system-x86_64: ../block/io.c:2041: bdrv_co_write_req_prepare:
>> Assertion `child->perm & BLK_PERM_WRITE' failed.
>> [1] 55880 IOT instruction (core dumped) ./qemu-system-x86_64
>> -object secret,id=sec0,data=123456 -object -blockdev
>>
>>
>> I believe this means we need some new block driver function to
>> prepare for an amendment operation. If so, another question comes
>> up, which is whether this preparatory function should then also call
>> bdrv_child_refresh_perms(), and then whether we should have a
>> clean-up function for symmetry.
>>
>
> Yes, unfortunately it means that (see at the end of the mail for more).
>
> I think it does not work because of crypto->updating_keys missing in
> blockdev_amend_pre_run(). That is why the permission is not correctly
> set and the example fails.
>
>
>>> +
>>> +static int blockdev_amend_pre_run(Job *job, Error **errp)
>>> +{
>>> + return blockdev_amend_refresh_perms(job, errp);
>>> +}
>>> +
>>> +static void blockdev_amend_clean(Job *job)
>>> +{
>>> + Error *errp;
>>> + blockdev_amend_refresh_perms(job, &errp);
>>
>> Do we really want to ignore this error? If so, we shouldn’t pass a
>> pointer to an unused local variable, but NULL.
>>
>> If we don’t want to ignore it, we have the option of doing what you
>> do here and then at least reporting a potential error with
>> error_report_err(), and then freeing it, and we also must initialize
>> errp to NULL in this case.
>
> Going with this one above, thanks.
>>
>> If we expect no error to happen (e.g. because we require the amend
>> implementation to only release/share permissions and not
>> acquire/unshare them), then I’d expect passing &error_abort here.
>>
>>> +}
>>> +
>>> static const JobDriver blockdev_amend_job_driver = {
>>> .instance_size = sizeof(BlockdevAmendJob),
>>> .job_type = JOB_TYPE_AMEND,
>>> .run = blockdev_amend_run,
>>> + .pre_run = blockdev_amend_pre_run,
>>> + .clean = blockdev_amend_clean,
>>> };
>>> void qmp_x_blockdev_amend(const char *job_id,
>>> diff --git a/block/crypto.c b/block/crypto.c
>>> index c8ba4681e2..82f154516c 100644
>>> --- a/block/crypto.c
>>> +++ b/block/crypto.c
>>> @@ -780,6 +780,7 @@
>>> block_crypto_get_specific_info_luks(BlockDriverState *bs, Error **errp)
>>> static int
>>> block_crypto_amend_options_generic_luks(BlockDriverState *bs,
>>> QCryptoBlockAmendOptions *amend_options,
>>> + bool under_bql,
>>
>> This name makes sense in the context of this series, but not so much
>> outside of it.
>>
>> I’d rename it to e.g. “in_amend_job” (and invert its value), and then
>> explain that we don’t need to refresh the child permissions when
>> running in an amend job, because that job has already taken care of
>> that.
>>
>> OTOH, given that I believe we need some separate preparatory function
>> anyway, perhaps we should just pull out the
>> bdrv_child_refresh_perms() from this function altogether, so that we
>> have:
>>
>> block_crypto_amend_options_luks():
>>
>> /* sets updating_keys to true, and invokes bdrv_child_refresh_perms() */
>> block_crypto_amend_options_prepare();
>> block_crypto_amend_options_generic_luks();
>> /* sets updating_keys to false, and invokes
>> bdrv_child_refresh_perms() */
>> block_crypto_amend_options_clean();
>>
>>
>> block_crypto_co_amend_luks():
>>
>> /* No need to prepare or clean up, that is taken care of by the amend
>> job */
>> block_crypto_amend_options_generic_luks();
>>
>>
>> (If we decide not to put bdrv_child_refresh_perms() into
>> prepare()/clean(), then it would need to be called by
>> block_crypto_amend_options_luks(); and if we decide not to have a
>> block_crypto_amend_options_clean(), then we’d need to inline it fully.)
>
> So a couple of things I will change (according with your feedbacks):
>
> - Remove the assertion job->aio_context == qemu_in_main_thread() done
> in job_co_entry, as it is wrong. I don't know why I added that, but we
> cannot assume that job->run() always run in the main context, because
> the job aiocontext can be different. I don't think there is a test
> doing that now, but it is possible. If run() was in the main context,
> then bdrv_co_amend (called only in blockdev_amend_run) would be GS
> too, but it isn't, also according with your comment in v4:
>
> "[...] .bdrv_co_amend very much strikes me like a GS function, but
> it isn’t. I’m afraid it must work on nodes that are not in the main
> context, and it launches a job, so AFAIU we absolutely cannot run it
> under the BQL."
>
> - Introduce block_crypto_amend_options_prepare and
> block_crypto_amend_options_clean, as you suggested above. These fix
> the GS call stack of block_crypto_amend_options_generic_luks()
>
> - Introduce .bdrv_pre_run() and .bdrv_cleanup(), respectively called
> by .job_pre_run() and .job_cleanup(). The reason is that we need to
> set crypto->updating_keys, otherwise the job amend won't temporary
> give the write permission so the example above would fail.
>
> So for the I/O callstack of block_crypto_amend_options_generic_luks()
> we will have:
> job->pre_run():
> .bdrv_pre_run();
> crypto->update_keys = true;
> blockdev_amend_refresh_perms()
>
> job->run():
> block_crypto_amend_options_generic_luks()
>
> job->cleanup():
> .bdrv_cleanup();
> crypto->update_keys = false;
> blockdev_amend_refresh_perms()
Sounds good! The only adjustment I’d make is to add “amend” somewhere
in the .bdrv functions (e.g. “.bdrv_amend_pre_run” and
“.bdrv_amend_cleanup”), because AFAIU they’ll still be amend-specific,
right?
(Happy holidays :))
Hanna
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 28/31] block.c: assert BQL lock held in bdrv_co_invalidate_cache
2021-12-23 17:11 ` Hanna Reitz
@ 2022-01-19 15:57 ` Hanna Reitz
2022-01-19 17:44 ` Hanna Reitz
0 siblings, 1 reply; 66+ messages in thread
From: Hanna Reitz @ 2022-01-19 15:57 UTC (permalink / raw)
To: Emanuele Giuseppe Esposito, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 23.12.21 18:11, Hanna Reitz wrote:
> On 20.12.21 13:20, Emanuele Giuseppe Esposito wrote:
>>
>>
>> On 17/12/2021 17:38, Emanuele Giuseppe Esposito wrote:
>>>
>>>
>>> On 17/12/2021 12:04, Hanna Reitz wrote:
>>>> On 24.11.21 07:44, Emanuele Giuseppe Esposito wrote:
>>>>> bdrv_co_invalidate_cache is special: it is an I/O function,
>>>>
>>>> I still don’t believe it is, but well.
>>>>
>>>> (Yes, it is called by a test in an iothread, but I believe we’ve
>>>> seen that the tests simply sometimes test things that shouldn’t be
>>>> allowed.)
>>>>
>>>>> but uses the block layer permission API, which is GS.
>>>>>
>>>>> Because of this, we can assert that either the function is
>>>>> being called with BQL held, and thus can use the permission API,
>>>>> or make sure that the permission API is not used, by ensuring that
>>>>> bs (and parents) .open_flags does not contain BDRV_O_INACTIVE.
>>>>>
>>>>> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
>>>>> ---
>>>>> block.c | 26 ++++++++++++++++++++++++++
>>>>> 1 file changed, 26 insertions(+)
>>>>>
>>>>> diff --git a/block.c b/block.c
>>>>> index a0309f827d..805974676b 100644
>>>>> --- a/block.c
>>>>> +++ b/block.c
>>>>> @@ -6574,6 +6574,26 @@ void bdrv_init_with_whitelist(void)
>>>>> bdrv_init();
>>>>> }
>>>>> +static bool bdrv_is_active(BlockDriverState *bs)
>>>>> +{
>>>>> + BdrvChild *parent;
>>>>> +
>>>>> + if (bs->open_flags & BDRV_O_INACTIVE) {
>>>>> + return false;
>>>>> + }
>>>>> +
>>>>> + QLIST_FOREACH(parent, &bs->parents, next_parent) {
>>>>> + if (parent->klass->parent_is_bds) {
>>>>> + BlockDriverState *parent_bs = parent->opaque;
>>>>
>>>> This looks like a really bad hack to me. We purposefully have made
>>>> the parent link opaque so that a BDS cannot easily reach its
>>>> parents. All accesses should go through BdrvChildClass methods.
>>>>
>>>> I also don’t understand why we need to query parents at all. The
>>>> only fact that determines whether the current BDS will have its
>>>> permissions changed is whether the BDS itself is active or
>>>> inactive. Sure, we’ll invoke bdrv_co_invalidate_cache() on the
>>>> parents, too, but then we could simply let the assertion fail there.
>>>>
>>>>> + if (!bdrv_is_active(parent_bs)) {
>>>>> + return false;
>>>>> + }
>>>>> + }
>>>>> + }
>>>>> +
>>>>> + return true;
>>>>> +}
>>>>> +
>>>>> int coroutine_fn bdrv_co_invalidate_cache(BlockDriverState *bs,
>>>>> Error **errp)
>>>>> {
>>>>> BdrvChild *child, *parent;
>>>>> @@ -6585,6 +6605,12 @@ int coroutine_fn
>>>>> bdrv_co_invalidate_cache(BlockDriverState *bs, Error **errp)
>>>>> return -ENOMEDIUM;
>>>>> }
>>>>> + /*
>>>>> + * No need to muck with permissions if bs is active.
>>>>> + * TODO: should activation be a separate function?
>>>>> + */
>>>>> + assert(qemu_in_main_thread() || bdrv_is_active(bs));
>>>>> +
>>>>
>>>> I don’t understand this, really. It looks to me like “if you don’t
>>>> call this in the main thread, this better be a no-op”, i.e., you
>>>> must never call this function in an I/O thread if you really want
>>>> to use it. I.e. what I’d classify as a GS function.
>>>>
>>>> It sounds like this is just a special case for said test, and
>>>> special-casing code for tests sounds like a bad idea.
>>>
>>> Ok, but trying to leave just the qemu_in_main_thread() assertion
>>> makes test 307 (./check 307) fail.
>>> I am actually not sure on why it fails, but I am sure it is because
>>> of the assertion, since without it it passes.
>>>
>>> I tried with gdb (./check -gdb 307 on one terminal and
>>> gdb -iex "target remote localhost:12345"
>>> in another) but it points me to this below, which I think is the ndb
>>> server getting the socket closed (because on the other side it
>>> crashed), and not the actual error.
>>>
>>>
>>> Thread 1 "qemu-system-x86" received signal SIGPIPE, Broken pipe.
>>> 0x00007ffff68af54d in sendmsg () from target:/lib64/libc.so.6
>>> (gdb) bt
>>> #0 0x00007ffff68af54d in sendmsg () from target:/lib64/libc.so.6
>>> #1 0x0000555555c13cc9 in qio_channel_socket_writev (ioc=<optimized
>>> out>, iov=0x5555569a4870, niov=1, fds=0x0, nfds=<optimized out>,
>>> errp=0x0)
>>> at ../io/channel-socket.c:561
>>> #2 0x0000555555c19b18 in qio_channel_writev_full_all
>>> (ioc=0x55555763b800, iov=iov@entry=0x7fffe8dffd80,
>>> niov=niov@entry=1, fds=fds@entry=0x0,
>>> nfds=nfds@entry=0, errp=errp@entry=0x0) at ../io/channel.c:240
>>> #3 0x0000555555c19bd2 in qio_channel_writev_all (errp=0x0, niov=1,
>>> iov=0x7fffe8dffd80, ioc=<optimized out>) at ../io/channel.c:220
>>> #4 qio_channel_write_all (ioc=<optimized out>,
>>> buf=buf@entry=0x7fffe8dffdd0 "", buflen=buflen@entry=20,
>>> errp=errp@entry=0x0) at ../io/channel.c:330
>>> #5 0x0000555555c27e75 in nbd_write (errp=0x0, size=20,
>>> buffer=0x7fffe8dffdd0, ioc=<optimized out>) at ../nbd/nbd-internal.h:71
>>> #6 nbd_negotiate_send_rep_len (client=client@entry=0x555556f60930,
>>> type=type@entry=1, len=len@entry=0, errp=errp@entry=0x0) at
>>> ../nbd/server.c:203
>>> #7 0x0000555555c29db1 in nbd_negotiate_send_rep (errp=0x0, type=1,
>>> client=0x555556f60930) at ../nbd/server.c:211
>>> --Type <RET> for more, q to quit, c to continue without paging--
>>> #8 nbd_negotiate_options (errp=0x7fffe8dffe88, client=<optimized
>>> out>) at ../nbd/server.c:1224
>>> #9 nbd_negotiate (errp=0x7fffe8dffe88, client=<optimized out>) at
>>> ../nbd/server.c:1340
>>> #10 nbd_co_client_start (opaque=<optimized out>) at
>>> ../nbd/server.c:2715
>>> #11 0x0000555555d70423 in coroutine_trampoline (i0=<optimized out>,
>>> i1=<optimized out>) at ../util/coroutine-ucontext.c:173
>>> #12 0x00007ffff67f3820 in ?? () from target:/lib64/libc.so.6
>>> #13 0x00007fffffffca80 in ?? ()
>>>
>>
>> Ok the reason for this is line 89 of tests/qemu-iotests/307:
>>
>> # Should ignore the iothread conflict, but then fail because of the
>> # permission conflict (and not crash)
>> vm.qmp_log('block-export-add', id='export1', type='nbd',
>> node_name='null',
>> iothread='iothread1', fixed_iothread=False,
>> writable=True)
>>
>> This calls qmp_block_export_add() and then blk_exp_add(), that calls
>> bdrv_invalidate_cache().
>> Both functions are running in the main thread, but then
>> bdrv_invalidate_cache invokes bdrv_co_invalidate_cache() as a
>> coroutine in the AioContext of the given bs, so not the main loop.
>>
>> So Hanna, what should we do here? This seems very similar to the
>> discussion in patch 22, ie run blockdev-create (in this case
>> block-export-add, which seems similar?) involving nodes in I/O threads.
>
> Honestly, I’m still thinking about this and haven’t come to a
> conclusion. It doesn’t seem invalid to run bdrv_co_invalidate_cache()
> in the context of the BDS here, but then the assertion that the BDS is
> already active seems kind of just lucky to work.
>
> I plan to look into whether I can reproduce some case where the
> assertion doesn’t hold (thinking of migration with a block device in
> an iothread), and then see what I learn from this. :/
OK, so. I nearly couldn’t reproduce a case where the assertion doesn’t
hold, and I was also very close to believing that your condition is
entirely correct; on migration, we generally inactivate block nodes
(BlockDriverStates) only after they have been detached from their
respective block devices, and so they’re in the main context. On the
destination, it’s the other way around: We invalidate their caches
before attaching them to the respective block devices, so they are again
in the main context.
There are exceptions where we call bdrv_invalidate_cache() on error
paths and so on, basically just to be sure, while the guest devices are
connected to block nodes. But in that case, we have never inactivated
them (or have already re-activated them), and that’s where the
`bdrv_is_active()` condition comes in.
But then I wanted to find out what happens when you don’t have a guest
device, but an NBD export on top of the block node, and this happens:
$ ./qemu-system-x86_64 \
-incoming defer \
-qmp stdio \
-object iothread,id=iothr0 \
-blockdev null-co,node-name=node0 \
<<EOF
{"execute": "qmp_capabilities"}
{"execute":"nbd-server-start","arguments":{"addr":{"type":"unix","data":{"path":"/tmp/nbd.sock"}}}}
{"execute":"block-export-add","arguments":{"type":"nbd","id":"exp0","iothread":"iothr0","node-name":"node0","name":"exp0"}}
EOF
{"QMP": {"version": {"qemu": {"micro": 91, "minor": 2, "major": 6},
"package": "v6.2.0-rc1-47-g043ab68869"}, "capabilities": ["oob"]}}
{"return": {}}
{"return": {}}
qemu-system-x86_64: ../block.c:6612: bdrv_co_invalidate_cache: Assertion
`qemu_in_main_thread() || bdrv_is_active(bs)' failed.
[1] 155729 abort (core dumped) ./qemu-system-x86_64 -incoming defer
-qmp stdio -object iothread,id=iothr0
The problem here is that blk_exp_add() invalidates the cache after
moving the node to the target context. I think we can solve this
particular problem by simply moving its bdrv_invalidate_cache() call
before the `if (export->has_iothread)` block above it.
But it does mean the search isn’t over and I’ll need to look a bit
further still... At least your assertion condition now makes more sense
to me.
Hanna
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 28/31] block.c: assert BQL lock held in bdrv_co_invalidate_cache
2022-01-19 15:57 ` Hanna Reitz
@ 2022-01-19 17:44 ` Hanna Reitz
0 siblings, 0 replies; 66+ messages in thread
From: Hanna Reitz @ 2022-01-19 17:44 UTC (permalink / raw)
To: Emanuele Giuseppe Esposito, qemu-block
Cc: Kevin Wolf, Fam Zheng, Vladimir Sementsov-Ogievskiy,
Daniel P. Berrangé,
Eduardo Habkost, Juan Quintela, qemu-devel, John Snow,
Richard Henderson, Markus Armbruster, Dr. David Alan Gilbert,
Stefan Hajnoczi, Paolo Bonzini, Eric Blake
On 19.01.22 16:57, Hanna Reitz wrote:
> On 23.12.21 18:11, Hanna Reitz wrote:
>> On 20.12.21 13:20, Emanuele Giuseppe Esposito wrote:
>>>
>>>
>>> On 17/12/2021 17:38, Emanuele Giuseppe Esposito wrote:
>>>>
>>>>
>>>> On 17/12/2021 12:04, Hanna Reitz wrote:
>>>>> On 24.11.21 07:44, Emanuele Giuseppe Esposito wrote:
>>>>>> bdrv_co_invalidate_cache is special: it is an I/O function,
>>>>>
>>>>> I still don’t believe it is, but well.
>>>>>
>>>>> (Yes, it is called by a test in an iothread, but I believe we’ve
>>>>> seen that the tests simply sometimes test things that shouldn’t be
>>>>> allowed.)
>>>>>
>>>>>> but uses the block layer permission API, which is GS.
>>>>>>
>>>>>> Because of this, we can assert that either the function is
>>>>>> being called with BQL held, and thus can use the permission API,
>>>>>> or make sure that the permission API is not used, by ensuring that
>>>>>> bs (and parents) .open_flags does not contain BDRV_O_INACTIVE.
>>>>>>
>>>>>> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
>>>>>> ---
>>>>>> block.c | 26 ++++++++++++++++++++++++++
>>>>>> 1 file changed, 26 insertions(+)
>>>>>>
>>>>>> diff --git a/block.c b/block.c
>>>>>> index a0309f827d..805974676b 100644
>>>>>> --- a/block.c
>>>>>> +++ b/block.c
>>>>>> @@ -6574,6 +6574,26 @@ void bdrv_init_with_whitelist(void)
>>>>>> bdrv_init();
>>>>>> }
>>>>>> +static bool bdrv_is_active(BlockDriverState *bs)
>>>>>> +{
>>>>>> + BdrvChild *parent;
>>>>>> +
>>>>>> + if (bs->open_flags & BDRV_O_INACTIVE) {
>>>>>> + return false;
>>>>>> + }
>>>>>> +
>>>>>> + QLIST_FOREACH(parent, &bs->parents, next_parent) {
>>>>>> + if (parent->klass->parent_is_bds) {
>>>>>> + BlockDriverState *parent_bs = parent->opaque;
>>>>>
>>>>> This looks like a really bad hack to me. We purposefully have
>>>>> made the parent link opaque so that a BDS cannot easily reach its
>>>>> parents. All accesses should go through BdrvChildClass methods.
>>>>>
>>>>> I also don’t understand why we need to query parents at all. The
>>>>> only fact that determines whether the current BDS will have its
>>>>> permissions changed is whether the BDS itself is active or
>>>>> inactive. Sure, we’ll invoke bdrv_co_invalidate_cache() on the
>>>>> parents, too, but then we could simply let the assertion fail there.
>>>>>
>>>>>> + if (!bdrv_is_active(parent_bs)) {
>>>>>> + return false;
>>>>>> + }
>>>>>> + }
>>>>>> + }
>>>>>> +
>>>>>> + return true;
>>>>>> +}
>>>>>> +
>>>>>> int coroutine_fn bdrv_co_invalidate_cache(BlockDriverState *bs,
>>>>>> Error **errp)
>>>>>> {
>>>>>> BdrvChild *child, *parent;
>>>>>> @@ -6585,6 +6605,12 @@ int coroutine_fn
>>>>>> bdrv_co_invalidate_cache(BlockDriverState *bs, Error **errp)
>>>>>> return -ENOMEDIUM;
>>>>>> }
>>>>>> + /*
>>>>>> + * No need to muck with permissions if bs is active.
>>>>>> + * TODO: should activation be a separate function?
>>>>>> + */
>>>>>> + assert(qemu_in_main_thread() || bdrv_is_active(bs));
>>>>>> +
>>>>>
>>>>> I don’t understand this, really. It looks to me like “if you
>>>>> don’t call this in the main thread, this better be a no-op”, i.e.,
>>>>> you must never call this function in an I/O thread if you really
>>>>> want to use it. I.e. what I’d classify as a GS function.
>>>>>
>>>>> It sounds like this is just a special case for said test, and
>>>>> special-casing code for tests sounds like a bad idea.
>>>>
>>>> Ok, but trying to leave just the qemu_in_main_thread() assertion
>>>> makes test 307 (./check 307) fail.
>>>> I am actually not sure on why it fails, but I am sure it is because
>>>> of the assertion, since without it it passes.
>>>>
>>>> I tried with gdb (./check -gdb 307 on one terminal and
>>>> gdb -iex "target remote localhost:12345"
>>>> in another) but it points me to this below, which I think is the
>>>> ndb server getting the socket closed (because on the other side it
>>>> crashed), and not the actual error.
>>>>
>>>>
>>>> Thread 1 "qemu-system-x86" received signal SIGPIPE, Broken pipe.
>>>> 0x00007ffff68af54d in sendmsg () from target:/lib64/libc.so.6
>>>> (gdb) bt
>>>> #0 0x00007ffff68af54d in sendmsg () from target:/lib64/libc.so.6
>>>> #1 0x0000555555c13cc9 in qio_channel_socket_writev (ioc=<optimized
>>>> out>, iov=0x5555569a4870, niov=1, fds=0x0, nfds=<optimized out>,
>>>> errp=0x0)
>>>> at ../io/channel-socket.c:561
>>>> #2 0x0000555555c19b18 in qio_channel_writev_full_all
>>>> (ioc=0x55555763b800, iov=iov@entry=0x7fffe8dffd80,
>>>> niov=niov@entry=1, fds=fds@entry=0x0,
>>>> nfds=nfds@entry=0, errp=errp@entry=0x0) at ../io/channel.c:240
>>>> #3 0x0000555555c19bd2 in qio_channel_writev_all (errp=0x0, niov=1,
>>>> iov=0x7fffe8dffd80, ioc=<optimized out>) at ../io/channel.c:220
>>>> #4 qio_channel_write_all (ioc=<optimized out>,
>>>> buf=buf@entry=0x7fffe8dffdd0 "", buflen=buflen@entry=20,
>>>> errp=errp@entry=0x0) at ../io/channel.c:330
>>>> #5 0x0000555555c27e75 in nbd_write (errp=0x0, size=20,
>>>> buffer=0x7fffe8dffdd0, ioc=<optimized out>) at
>>>> ../nbd/nbd-internal.h:71
>>>> #6 nbd_negotiate_send_rep_len (client=client@entry=0x555556f60930,
>>>> type=type@entry=1, len=len@entry=0, errp=errp@entry=0x0) at
>>>> ../nbd/server.c:203
>>>> #7 0x0000555555c29db1 in nbd_negotiate_send_rep (errp=0x0, type=1,
>>>> client=0x555556f60930) at ../nbd/server.c:211
>>>> --Type <RET> for more, q to quit, c to continue without paging--
>>>> #8 nbd_negotiate_options (errp=0x7fffe8dffe88, client=<optimized
>>>> out>) at ../nbd/server.c:1224
>>>> #9 nbd_negotiate (errp=0x7fffe8dffe88, client=<optimized out>) at
>>>> ../nbd/server.c:1340
>>>> #10 nbd_co_client_start (opaque=<optimized out>) at
>>>> ../nbd/server.c:2715
>>>> #11 0x0000555555d70423 in coroutine_trampoline (i0=<optimized out>,
>>>> i1=<optimized out>) at ../util/coroutine-ucontext.c:173
>>>> #12 0x00007ffff67f3820 in ?? () from target:/lib64/libc.so.6
>>>> #13 0x00007fffffffca80 in ?? ()
>>>>
>>>
>>> Ok the reason for this is line 89 of tests/qemu-iotests/307:
>>>
>>> # Should ignore the iothread conflict, but then fail because of the
>>> # permission conflict (and not crash)
>>> vm.qmp_log('block-export-add', id='export1', type='nbd',
>>> node_name='null',
>>> iothread='iothread1', fixed_iothread=False,
>>> writable=True)
>>>
>>> This calls qmp_block_export_add() and then blk_exp_add(), that calls
>>> bdrv_invalidate_cache().
>>> Both functions are running in the main thread, but then
>>> bdrv_invalidate_cache invokes bdrv_co_invalidate_cache() as a
>>> coroutine in the AioContext of the given bs, so not the main loop.
>>>
>>> So Hanna, what should we do here? This seems very similar to the
>>> discussion in patch 22, ie run blockdev-create (in this case
>>> block-export-add, which seems similar?) involving nodes in I/O threads.
>>
>> Honestly, I’m still thinking about this and haven’t come to a
>> conclusion. It doesn’t seem invalid to run
>> bdrv_co_invalidate_cache() in the context of the BDS here, but then
>> the assertion that the BDS is already active seems kind of just lucky
>> to work.
>>
>> I plan to look into whether I can reproduce some case where the
>> assertion doesn’t hold (thinking of migration with a block device in
>> an iothread), and then see what I learn from this. :/
>
> OK, so. I nearly couldn’t reproduce a case where the assertion
> doesn’t hold, and I was also very close to believing that your
> condition is entirely correct; on migration, we generally inactivate
> block nodes (BlockDriverStates) only after they have been detached
> from their respective block devices, and so they’re in the main
> context. On the destination, it’s the other way around: We invalidate
> their caches before attaching them to the respective block devices, so
> they are again in the main context.
Correcting myself: It doesn’t have to do anything with
attaching/detaching, it’s that the guest puts the BDS into the non-main
context only if the vmstate is “running”.
(virtio_pci_vmstate_change() is invoked on vmstate changes, and
virtio_blk_class_init() registers virtio_blk_data_plane_{start,stop}()
as the {start,stop}_ioeventfd callbacks.)
So it’s even better, the devices actually take care to put the BDS nodes
into the main context while migration is ongoing.
> There are exceptions where we call bdrv_invalidate_cache() on error
> paths and so on, basically just to be sure, while the guest devices
> are connected to block nodes. But in that case, we have never
> inactivated them (or have already re-activated them), and that’s where
> the `bdrv_is_active()` condition comes in.
>
> But then I wanted to find out what happens when you don’t have a guest
> device, but an NBD export on top of the block node, and this happens:
>
> $ ./qemu-system-x86_64 \
> -incoming defer \
> -qmp stdio \
> -object iothread,id=iothr0 \
> -blockdev null-co,node-name=node0 \
> <<EOF
> {"execute": "qmp_capabilities"}
> {"execute":"nbd-server-start","arguments":{"addr":{"type":"unix","data":{"path":"/tmp/nbd.sock"}}}}
>
> {"execute":"block-export-add","arguments":{"type":"nbd","id":"exp0","iothread":"iothr0","node-name":"node0","name":"exp0"}}
>
> EOF
> {"QMP": {"version": {"qemu": {"micro": 91, "minor": 2, "major": 6},
> "package": "v6.2.0-rc1-47-g043ab68869"}, "capabilities": ["oob"]}}
> {"return": {}}
> {"return": {}}
> qemu-system-x86_64: ../block.c:6612: bdrv_co_invalidate_cache:
> Assertion `qemu_in_main_thread() || bdrv_is_active(bs)' failed.
> [1] 155729 abort (core dumped) ./qemu-system-x86_64 -incoming
> defer -qmp stdio -object iothread,id=iothr0
>
> The problem here is that blk_exp_add() invalidates the cache after
> moving the node to the target context. I think we can solve this
> particular problem by simply moving its bdrv_invalidate_cache() call
> before the `if (export->has_iothread)` block above it.
And that means that this makes even more sense, because if the virtio
devices take care to keep their block device in the main context while
migration is ongoing, blk_exp_add() should do the same when it calls a
“migration function” (bdrv_invalidate_cache()).
> But it does mean the search isn’t over and I’ll need to look a bit
> further still...
Did look further, couldn’t find anything else interesting.
So I think(TM) that this blk_exp_add() is the only thing that needs fixing.
Hanna
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 28/31] block.c: assert BQL lock held in bdrv_co_invalidate_cache
2021-12-20 12:20 ` Emanuele Giuseppe Esposito
2021-12-23 17:11 ` Hanna Reitz
@ 2022-01-19 18:34 ` Kevin Wolf
2022-01-20 13:22 ` Paolo Bonzini
1 sibling, 1 reply; 66+ messages in thread
From: Kevin Wolf @ 2022-01-19 18:34 UTC (permalink / raw)
To: Emanuele Giuseppe Esposito
Cc: Fam Zheng, Vladimir Sementsov-Ogievskiy, Daniel P. Berrangé,
Eduardo Habkost, qemu-block, Juan Quintela, qemu-devel,
John Snow, Richard Henderson, Markus Armbruster,
Dr. David Alan Gilbert, Hanna Reitz, Stefan Hajnoczi,
Paolo Bonzini, Eric Blake
Am 20.12.2021 um 13:20 hat Emanuele Giuseppe Esposito geschrieben:
>
>
> On 17/12/2021 17:38, Emanuele Giuseppe Esposito wrote:
> >
> >
> > On 17/12/2021 12:04, Hanna Reitz wrote:
> > > On 24.11.21 07:44, Emanuele Giuseppe Esposito wrote:
> > > > bdrv_co_invalidate_cache is special: it is an I/O function,
> > >
> > > I still don’t believe it is, but well.
> > >
> > > (Yes, it is called by a test in an iothread, but I believe we’ve
> > > seen that the tests simply sometimes test things that shouldn’t be
> > > allowed.)
> > >
> > > > but uses the block layer permission API, which is GS.
> > > >
> > > > Because of this, we can assert that either the function is
> > > > being called with BQL held, and thus can use the permission API,
> > > > or make sure that the permission API is not used, by ensuring that
> > > > bs (and parents) .open_flags does not contain BDRV_O_INACTIVE.
> > > >
> > > > Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
> > > > ---
> > > > block.c | 26 ++++++++++++++++++++++++++
> > > > 1 file changed, 26 insertions(+)
> > > >
> > > > diff --git a/block.c b/block.c
> > > > index a0309f827d..805974676b 100644
> > > > --- a/block.c
> > > > +++ b/block.c
> > > > @@ -6574,6 +6574,26 @@ void bdrv_init_with_whitelist(void)
> > > > bdrv_init();
> > > > }
> > > > +static bool bdrv_is_active(BlockDriverState *bs)
> > > > +{
> > > > + BdrvChild *parent;
> > > > +
> > > > + if (bs->open_flags & BDRV_O_INACTIVE) {
> > > > + return false;
> > > > + }
> > > > +
> > > > + QLIST_FOREACH(parent, &bs->parents, next_parent) {
> > > > + if (parent->klass->parent_is_bds) {
> > > > + BlockDriverState *parent_bs = parent->opaque;
> > >
> > > This looks like a really bad hack to me. We purposefully have made
> > > the parent link opaque so that a BDS cannot easily reach its
> > > parents. All accesses should go through BdrvChildClass methods.
> > >
> > > I also don’t understand why we need to query parents at all. The
> > > only fact that determines whether the current BDS will have its
> > > permissions changed is whether the BDS itself is active or
> > > inactive. Sure, we’ll invoke bdrv_co_invalidate_cache() on the
> > > parents, too, but then we could simply let the assertion fail there.
> > >
> > > > + if (!bdrv_is_active(parent_bs)) {
> > > > + return false;
> > > > + }
> > > > + }
> > > > + }
> > > > +
> > > > + return true;
> > > > +}
> > > > +
> > > > int coroutine_fn bdrv_co_invalidate_cache(BlockDriverState
> > > > *bs, Error **errp)
> > > > {
> > > > BdrvChild *child, *parent;
> > > > @@ -6585,6 +6605,12 @@ int coroutine_fn
> > > > bdrv_co_invalidate_cache(BlockDriverState *bs, Error **errp)
> > > > return -ENOMEDIUM;
> > > > }
> > > > + /*
> > > > + * No need to muck with permissions if bs is active.
> > > > + * TODO: should activation be a separate function?
> > > > + */
> > > > + assert(qemu_in_main_thread() || bdrv_is_active(bs));
> > > > +
> > >
> > > I don’t understand this, really. It looks to me like “if you don’t
> > > call this in the main thread, this better be a no-op”, i.e., you
> > > must never call this function in an I/O thread if you really want to
> > > use it. I.e. what I’d classify as a GS function.
> > >
> > > It sounds like this is just a special case for said test, and
> > > special-casing code for tests sounds like a bad idea.
> >
> > Ok, but trying to leave just the qemu_in_main_thread() assertion makes
> > test 307 (./check 307) fail.
> > I am actually not sure on why it fails, but I am sure it is because of
> > the assertion, since without it it passes.
> >
> > I tried with gdb (./check -gdb 307 on one terminal and
> > gdb -iex "target remote localhost:12345"
> > in another) but it points me to this below, which I think is the ndb
> > server getting the socket closed (because on the other side it crashed),
> > and not the actual error.
> >
> >
> > Thread 1 "qemu-system-x86" received signal SIGPIPE, Broken pipe.
> > 0x00007ffff68af54d in sendmsg () from target:/lib64/libc.so.6
> > (gdb) bt
> > #0 0x00007ffff68af54d in sendmsg () from target:/lib64/libc.so.6
> > #1 0x0000555555c13cc9 in qio_channel_socket_writev (ioc=<optimized
> > out>, iov=0x5555569a4870, niov=1, fds=0x0, nfds=<optimized out>,
> > errp=0x0)
> > at ../io/channel-socket.c:561
> > #2 0x0000555555c19b18 in qio_channel_writev_full_all
> > (ioc=0x55555763b800, iov=iov@entry=0x7fffe8dffd80, niov=niov@entry=1,
> > fds=fds@entry=0x0,
> > nfds=nfds@entry=0, errp=errp@entry=0x0) at ../io/channel.c:240
> > #3 0x0000555555c19bd2 in qio_channel_writev_all (errp=0x0, niov=1,
> > iov=0x7fffe8dffd80, ioc=<optimized out>) at ../io/channel.c:220
> > #4 qio_channel_write_all (ioc=<optimized out>,
> > buf=buf@entry=0x7fffe8dffdd0 "", buflen=buflen@entry=20,
> > errp=errp@entry=0x0) at ../io/channel.c:330
> > #5 0x0000555555c27e75 in nbd_write (errp=0x0, size=20,
> > buffer=0x7fffe8dffdd0, ioc=<optimized out>) at ../nbd/nbd-internal.h:71
> > #6 nbd_negotiate_send_rep_len (client=client@entry=0x555556f60930,
> > type=type@entry=1, len=len@entry=0, errp=errp@entry=0x0) at
> > ../nbd/server.c:203
> > #7 0x0000555555c29db1 in nbd_negotiate_send_rep (errp=0x0, type=1,
> > client=0x555556f60930) at ../nbd/server.c:211
> > --Type <RET> for more, q to quit, c to continue without paging--
> > #8 nbd_negotiate_options (errp=0x7fffe8dffe88, client=<optimized out>)
> > at ../nbd/server.c:1224
> > #9 nbd_negotiate (errp=0x7fffe8dffe88, client=<optimized out>) at
> > ../nbd/server.c:1340
> > #10 nbd_co_client_start (opaque=<optimized out>) at ../nbd/server.c:2715
> > #11 0x0000555555d70423 in coroutine_trampoline (i0=<optimized out>,
> > i1=<optimized out>) at ../util/coroutine-ucontext.c:173
> > #12 0x00007ffff67f3820 in ?? () from target:/lib64/libc.so.6
> > #13 0x00007fffffffca80 in ?? ()
> >
>
> Ok the reason for this is line 89 of tests/qemu-iotests/307:
>
> # Should ignore the iothread conflict, but then fail because of the
> # permission conflict (and not crash)
> vm.qmp_log('block-export-add', id='export1', type='nbd', node_name='null',
> iothread='iothread1', fixed_iothread=False, writable=True)
>
> This calls qmp_block_export_add() and then blk_exp_add(), that calls
> bdrv_invalidate_cache().
> Both functions are running in the main thread, but then
> bdrv_invalidate_cache invokes bdrv_co_invalidate_cache() as a coroutine in
> the AioContext of the given bs, so not the main loop.
>
> So Hanna, what should we do here? This seems very similar to the discussion
> in patch 22, ie run blockdev-create (in this case block-export-add, which
> seems similar?) involving nodes in I/O threads.
My gut feeling is that the bug is that we're entering coroutine context
in the node's iothread too early. I think the only place where we really
need it is the bs->drv->bdrv_co_invalidate_cache() call.
In fact, not only permission code, but also parent->klass->activate()
must be run in the main thread. The only implementation of the callback
is blk_root_activate(), and it calls some permissions functions, too,
but also qemu_add_vm_change_state_handler(), which doesn't look thread
safe. Unlikely to ever cause problems and if it does, it won't be
reproducible, but still a bug.
So if we go back to a bdrv_invalidate_cache() that does all the graph
manipulations (and asserts that we're in the main loop) and then have a
much smaller bdrv_co_invalidate_cache() that basically just calls into
the driver, would that solve the problem?
Kevin
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 28/31] block.c: assert BQL lock held in bdrv_co_invalidate_cache
2022-01-19 18:34 ` Kevin Wolf
@ 2022-01-20 13:22 ` Paolo Bonzini
2022-01-20 13:48 ` Kevin Wolf
0 siblings, 1 reply; 66+ messages in thread
From: Paolo Bonzini @ 2022-01-20 13:22 UTC (permalink / raw)
To: Kevin Wolf, Emanuele Giuseppe Esposito
Cc: Fam Zheng, Vladimir Sementsov-Ogievskiy, Daniel P. Berrangé,
Eduardo Habkost, qemu-block, Juan Quintela, Eric Blake,
Richard Henderson, qemu-devel, Markus Armbruster, Hanna Reitz,
Stefan Hajnoczi, John Snow, Dr. David Alan Gilbert
On 1/19/22 19:34, Kevin Wolf wrote:
> So if we go back to a bdrv_invalidate_cache() that does all the graph
> manipulations (and asserts that we're in the main loop) and then have a
> much smaller bdrv_co_invalidate_cache() that basically just calls into
> the driver, would that solve the problem?
I was going to suggest something similar, and even name the former
bdrv_activate(). Then bdrv_activate() is a graph manipulation function,
while bdrv_co_invalidate_cache() is an I/O function.
Paolo
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 28/31] block.c: assert BQL lock held in bdrv_co_invalidate_cache
2022-01-20 13:22 ` Paolo Bonzini
@ 2022-01-20 13:48 ` Kevin Wolf
2022-01-21 10:22 ` Emanuele Giuseppe Esposito
0 siblings, 1 reply; 66+ messages in thread
From: Kevin Wolf @ 2022-01-20 13:48 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Emanuele Giuseppe Esposito, Fam Zheng,
Vladimir Sementsov-Ogievskiy, Daniel P. Berrangé,
Eduardo Habkost, qemu-block, Juan Quintela, Eric Blake,
Richard Henderson, qemu-devel, Markus Armbruster, Hanna Reitz,
Stefan Hajnoczi, John Snow, Dr. David Alan Gilbert
Am 20.01.2022 um 14:22 hat Paolo Bonzini geschrieben:
> On 1/19/22 19:34, Kevin Wolf wrote:
> > So if we go back to a bdrv_invalidate_cache() that does all the graph
> > manipulations (and asserts that we're in the main loop) and then have a
> > much smaller bdrv_co_invalidate_cache() that basically just calls into
> > the driver, would that solve the problem?
>
> I was going to suggest something similar, and even name the former
> bdrv_activate(). Then bdrv_activate() is a graph manipulation function,
> while bdrv_co_invalidate_cache() is an I/O function.
I like this. The naming inconsistency between inactivate and
invalidate_cache has always bothered me.
Kevin
^ permalink raw reply [flat|nested] 66+ messages in thread
* Re: [PATCH v5 28/31] block.c: assert BQL lock held in bdrv_co_invalidate_cache
2022-01-20 13:48 ` Kevin Wolf
@ 2022-01-21 10:22 ` Emanuele Giuseppe Esposito
0 siblings, 0 replies; 66+ messages in thread
From: Emanuele Giuseppe Esposito @ 2022-01-21 10:22 UTC (permalink / raw)
To: Kevin Wolf, Paolo Bonzini, Hanna Reitz
Cc: Fam Zheng, Vladimir Sementsov-Ogievskiy, Daniel P. Berrangé,
Eduardo Habkost, qemu-block, Juan Quintela, Eric Blake,
Richard Henderson, qemu-devel, Markus Armbruster,
Stefan Hajnoczi, John Snow, Dr. David Alan Gilbert
On 20/01/2022 14:48, Kevin Wolf wrote:
> Am 20.01.2022 um 14:22 hat Paolo Bonzini geschrieben:
>> On 1/19/22 19:34, Kevin Wolf wrote:
>>> So if we go back to a bdrv_invalidate_cache() that does all the graph
>>> manipulations (and asserts that we're in the main loop) and then have a
>>> much smaller bdrv_co_invalidate_cache() that basically just calls into
>>> the driver, would that solve the problem?
>>
>> I was going to suggest something similar, and even name the former
>> bdrv_activate(). Then bdrv_activate() is a graph manipulation function,
>> while bdrv_co_invalidate_cache() is an I/O function.
>
> I like this. The naming inconsistency between inactivate and
> invalidate_cache has always bothered me.
>
Ok, I am going to apply this. Thank you for the suggestion!
> Did look further, couldn’t find anything else interesting.
> So I think(TM) that this blk_exp_add() is the only thing that needs fixing.
When splitting the logic between bdrv_activate and
bdrv_co_invalidate_cache, there is no need anymore to fix blk_exp_add :)
I am going to send v6 by the end of today.
Thank you,
Emanuele
^ permalink raw reply [flat|nested] 66+ messages in thread
end of thread, other threads:[~2022-01-21 10:46 UTC | newest]
Thread overview: 66+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-11-24 6:43 [PATCH v5 00/31] block layer: split block APIs in global state and I/O Emanuele Giuseppe Esposito
2021-11-24 6:43 ` [PATCH v5 01/31] main-loop.h: introduce qemu_in_main_thread() Emanuele Giuseppe Esposito
2021-11-24 6:43 ` [PATCH v5 02/31] include/block/block: split header into I/O and global state API Emanuele Giuseppe Esposito
2021-11-24 6:43 ` [PATCH v5 03/31] assertions for block " Emanuele Giuseppe Esposito
2021-12-16 15:17 ` Hanna Reitz
2021-11-24 6:43 ` [PATCH v5 04/31] include/sysemu/block-backend: split header into I/O and global state (GS) API Emanuele Giuseppe Esposito
2021-12-10 14:21 ` Hanna Reitz
2021-11-24 6:43 ` [PATCH v5 05/31] block-backend: special comments for blk_set/get_perm due to fuse Emanuele Giuseppe Esposito
2021-12-10 14:38 ` Hanna Reitz
2021-12-15 8:57 ` Emanuele Giuseppe Esposito
2021-12-15 10:13 ` Emanuele Giuseppe Esposito
2021-12-16 14:00 ` Hanna Reitz
2021-11-24 6:43 ` [PATCH v5 06/31] block/block-backend.c: assertions for block-backend Emanuele Giuseppe Esposito
2021-12-10 15:37 ` Hanna Reitz
2021-11-24 6:43 ` [PATCH v5 07/31] include/block/block_int: split header into I/O and global state API Emanuele Giuseppe Esposito
2021-11-24 6:43 ` [PATCH v5 08/31] assertions for block_int " Emanuele Giuseppe Esposito
2021-11-24 6:43 ` [PATCH v5 09/31] block: introduce assert_bdrv_graph_writable Emanuele Giuseppe Esposito
2021-12-10 17:43 ` Hanna Reitz
2021-12-14 19:48 ` Emanuele Giuseppe Esposito
2021-12-16 14:01 ` Hanna Reitz
2021-11-24 6:43 ` [PATCH v5 10/31] block.c: modify .attach and .detach callbacks of child_of_bds Emanuele Giuseppe Esposito
2021-12-16 14:57 ` Hanna Reitz
2021-12-16 16:05 ` Emanuele Giuseppe Esposito
2021-12-16 16:12 ` Hanna Reitz
2021-11-24 6:43 ` [PATCH v5 11/31] include/block/blockjob_int.h: split header into I/O and GS API Emanuele Giuseppe Esposito
2021-11-24 6:43 ` [PATCH v5 12/31] assertions for blockjob_int.h Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 13/31] block.c: add assertions to static functions Emanuele Giuseppe Esposito
2021-12-16 16:08 ` Hanna Reitz
2021-12-16 16:39 ` Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 14/31] include/block/blockjob.h: global state API Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 15/31] assertions for blockjob.h " Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 16/31] include/sysemu/blockdev.h: " Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 17/31] assertions for blockdev.h " Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 18/31] include/block/snapshot: global state API + assertions Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 19/31] block/copy-before-write.h: " Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 20/31] block/coroutines: I/O API Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 21/31] block_int-common.h: split function pointers in BlockDriver Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 22/31] block_int-common.h: assertion in the callers of BlockDriver function pointers Emanuele Giuseppe Esposito
2021-12-16 18:43 ` Hanna Reitz
2021-12-17 15:53 ` Emanuele Giuseppe Esposito
2021-12-17 16:00 ` Hanna Reitz
2021-11-24 6:44 ` [PATCH v5 23/31] block_int-common.h: split function pointers in BdrvChildClass Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 24/31] block_int-common.h: assertions in the callers of BdrvChildClass function pointers Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 25/31] block-backend-common.h: split function pointers in BlockDevOps Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 26/31] job.h: split function pointers in JobDriver Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 27/31] job.h: assertions in the callers of JobDriver funcion pointers Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 28/31] block.c: assert BQL lock held in bdrv_co_invalidate_cache Emanuele Giuseppe Esposito
2021-12-17 11:04 ` Hanna Reitz
2021-12-17 16:38 ` Emanuele Giuseppe Esposito
2021-12-20 12:20 ` Emanuele Giuseppe Esposito
2021-12-23 17:11 ` Hanna Reitz
2022-01-19 15:57 ` Hanna Reitz
2022-01-19 17:44 ` Hanna Reitz
2022-01-19 18:34 ` Kevin Wolf
2022-01-20 13:22 ` Paolo Bonzini
2022-01-20 13:48 ` Kevin Wolf
2022-01-21 10:22 ` Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 29/31] jobs: introduce pre_run function in JobDriver Emanuele Giuseppe Esposito
2021-11-24 6:44 ` [PATCH v5 30/31] crypto: delegate permission functions to JobDriver .pre_run Emanuele Giuseppe Esposito
2021-12-17 12:29 ` Hanna Reitz
2021-12-17 14:32 ` Hanna Reitz
2021-12-20 15:47 ` Emanuele Giuseppe Esposito
2021-12-23 17:15 ` Hanna Reitz
2021-11-24 6:44 ` [PATCH v5 31/31] block.c: assertions to the block layer permissions API Emanuele Giuseppe Esposito
2021-11-29 13:32 ` [PATCH v5 00/31] block layer: split block APIs in global state and I/O Stefan Hajnoczi
2021-11-30 8:39 ` Emanuele Giuseppe Esposito
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