[Qemu-devel] [PATCH v5 00/38] blockdev: BlockBackend and media

[Qemu-devel] [PATCH v5 00/38] blockdev: BlockBackend and media

[Max Reitz]

This series reworks a lot regarding BlockBackend and media. Basically,
it allows empty BlockBackends, that is BBs without a BDS tree.

Before this series, empty drives are represented by a BlockBackend with
an empty BDS attached to it (a BDS with a NULL driver). However, now we
have BlockBackends, thus an empty drive should be represented by a
BlockBackend without any BDS tree attached to it. This is what this
series does.


Quick and early summary for the v5 changes:
- Rebase on master
- Addressed Kevin's comments for v4


Justification for each of the patches and their order:

-- Preparation before _is_inserted() patches --
 1: Patch 9 will not take care not to break host floppy support, so that
    support needs to be removed first.
 2: Needed for patch 3, so that blockdev-added BDSs without a BB still
    get the BDRV_O_INCOMING flag set.
 3: Needed for patch 4. Patch 25 is a follow-up after BDS-less BBs are
    allowed.
 4: bdrv_close_all() is broken ("block: Rework bdrv_close_all()"). Patch
    7 will break iotest 071 (actually, just make the problem apparent).
    So this patch is required to work around the issue.
    (with "the issue" being that bdrv_close_all() does not unref() the
    BDSs it is closing, but just force-closes everything, even if the
    BDS may still be in use somewhere)

-- _is_inserted() patches --
 5: General clean-up work, nice to have before patch 7 (and goes in tune
    with patch 6).
 6: Using the same BB as a guest device means that the data read from
    there should be exactly the same. Opening the guest tray should
    therefore result in no data being readable. This is what we then
    need this function for.
 7: General clean-up work (in the _is_inserted() area).
 8: General clean-up work (in the _is_inserted() area).
 9: General clean-up work (also regarding _is_inserted()).
10: Required so inserting a floppy will not result in the tray being
    reported as closed (you need to "push in" the floppy first, using
    blockdev-close-tray). It's here in the "_is_inserted() patches area"
    because I feel like that's a very related topic.

-- Support for BDS-less BBs --
11: Preparation for BDS-less BBs
12: Preparation for BDS-less BBs
13: Preparation for BDS-less BBs (BB properties should be in the BB, and
    not in the root BDS)
14: Patch 15 removes BlockAcctStats from the BDS, but wr_highest_sector
    is BDS-dependent, so it needs to stay here
15: Preparation for BDS-less BBs (BB properties should be in the BB, and
    not in the root BDS)
16: Preparation for BDS-less BBs (BB properties should be in the BB, and
    not in the root BDS)
17: Preparation for BDS-less BBs (Removing a BDS tree should retain some
    properties for legacy reasons, which must therefore be stored in the
    BB(RS))
18: Preparation for BDS-less BBs
19: Preparation for BDS-less BBs
20: Preparation for BDS-less BBs
21: Ability to add BDS trees to empty BBs ("inserting a medium")
22: Preparation for BDS-less BBs (needs patch 21)
23: One goal of this series, and fixes the "opening tray" event for
    empty drives when shutting down qemu
24: Needed for patch 25
25: Completion of what patch 3 begun
26: Ability to detach BDS trees from BBs

-- "Atomic" QMP tray operations --
27: blockdev-open-tray
28: blockdev-close-tray
29: blockdev-remove-medium
30: blockdev-insert-medium

-- Reimplementation of change/eject --
31: eject
32: change
33: Clean-up patch

-- New QMP blockdev-change-medium command --
34: New QMP command
35: Use for HMP change command
36: Add flag to that command for changing the read-only access mode
    (which was my original intention for this series)
37: Same flag for HMP

-- Tests --
38: iotests are always nice, so here is one


v5:
- Patch 1: [Kevin]
  - Drop fd_open() stub, use the FreeBSD implementation for every
    platform
  - s/2\.4/2.5/
- Patch 2: Added, required for patch 3 [Kevin]
- Patch 3: @drv parameter has been dropped from bdrv_open()
- Patch 4: Fix up some blockdev-add invocations [Kevin]
- Patch 7: Good thing we have a generic children list now, we can use
  that for a more generic recursive bdrv_is_inserted() [Kevein]
- Patch 10: As of 2711fd33a4b18c5e35a6f7efe57b5d868def829e (-nodefaults
  for the iotests) the tests previously broken by this patch no longer
  have the affected output, thereby making fixing them unnecessary
- Patch 22: Rebase conflicts due to the @drv dropping patches
- Patch 23:
  - Rebase conflict due the new patch 2 (a good thing)
  - Same as for patch 10: The tests no longer need to be fixed
- Patch 25: Rebase conflicts due to the @drv dropping patches
- Patch 32: Rebase conflicts due to the @drv dropping patches


git-backport-diff against v4:

Key:
[----] : patches are identical
[####] : number of functional differences between upstream/downstream patch
[down] : patch is downstream-only
The flags [FC] indicate (F)unctional and (C)ontextual differences, respectively

001/38:[0011] [FC] 'block: Remove host floppy support'
002/38:[down] 'block: Set BDRV_O_INCOMING in bdrv_fill_options()'
003/38:[0002] [FC] 'blockdev: Allow creation of BDS trees without BB'
004/38:[0020] [FC] 'iotests: Only create BB if necessary'
005/38:[----] [--] 'block: Make bdrv_is_inserted() return a bool'
006/38:[----] [--] 'block: Add blk_is_available()'
007/38:[0013] [FC] 'block: Make bdrv_is_inserted() recursive'
008/38:[down] 'block/raw_bsd: Drop raw_is_inserted()'
009/38:[----] [--] 'block: Invoke change media CB before NULLing drv'
010/38:[0069] [FC] 'hw/block/fdc: Implement tray status'
011/38:[----] [--] 'hw/usb-storage: Check whether BB is inserted'
012/38:[----] [--] 'block: Fix BB AIOCB AioContext without BDS'
013/38:[----] [--] 'block: Move guest_block_size into BlockBackend'
014/38:[----] [--] 'block: Remove wr_highest_sector from BlockAcctStats'
015/38:[----] [--] 'block: Move BlockAcctStats into BlockBackend'
016/38:[----] [--] 'block: Move I/O status and error actions into BB'
017/38:[----] [--] 'block: Add BlockBackendRootState'
018/38:[----] [--] 'block: Make some BB functions fall back to BBRS'
019/38:[----] [--] 'block: Fail requests to empty BlockBackend'
020/38:[----] [--] 'block: Prepare remaining BB functions for NULL BDS'
021/38:[----] [--] 'block: Add blk_insert_bs()'
022/38:[0010] [FC] 'block: Prepare for NULL BDS'
023/38:[0057] [FC] 'blockdev: Do not create BDS for empty drive'
024/38:[----] [--] 'blockdev: Pull out blockdev option extraction'
025/38:[0004] [FC] 'blockdev: Allow more options for BB-less BDS tree'
026/38:[----] [--] 'block: Add blk_remove_bs()'
027/38:[----] [--] 'blockdev: Add blockdev-open-tray'
028/38:[----] [--] 'blockdev: Add blockdev-close-tray'
029/38:[----] [--] 'blockdev: Add blockdev-remove-medium'
030/38:[----] [--] 'blockdev: Add blockdev-insert-medium'
031/38:[----] [--] 'blockdev: Implement eject with basic operations'
032/38:[0032] [FC] 'blockdev: Implement change with basic operations'
033/38:[----] [--] 'block: Inquire tray state before tray-moved events'
034/38:[----] [-C] 'qmp: Introduce blockdev-change-medium'
035/38:[----] [--] 'hmp: Use blockdev-change-medium for change command'
036/38:[----] [--] 'blockdev: read-only-mode for blockdev-change-medium'
037/38:[----] [--] 'hmp: Add read-only-mode option to change command'
038/38:[----] [--] 'iotests: Add test for change-related QMP commands'


Max Reitz (38):
  block: Remove host floppy support
  block: Set BDRV_O_INCOMING in bdrv_fill_options()
  blockdev: Allow creation of BDS trees without BB
  iotests: Only create BB if necessary
  block: Make bdrv_is_inserted() return a bool
  block: Add blk_is_available()
  block: Make bdrv_is_inserted() recursive
  block/raw_bsd: Drop raw_is_inserted()
  block: Invoke change media CB before NULLing drv
  hw/block/fdc: Implement tray status
  hw/usb-storage: Check whether BB is inserted
  block: Fix BB AIOCB AioContext without BDS
  block: Move guest_block_size into BlockBackend
  block: Remove wr_highest_sector from BlockAcctStats
  block: Move BlockAcctStats into BlockBackend
  block: Move I/O status and error actions into BB
  block: Add BlockBackendRootState
  block: Make some BB functions fall back to BBRS
  block: Fail requests to empty BlockBackend
  block: Prepare remaining BB functions for NULL BDS
  block: Add blk_insert_bs()
  block: Prepare for NULL BDS
  blockdev: Do not create BDS for empty drive
  blockdev: Pull out blockdev option extraction
  blockdev: Allow more options for BB-less BDS tree
  block: Add blk_remove_bs()
  blockdev: Add blockdev-open-tray
  blockdev: Add blockdev-close-tray
  blockdev: Add blockdev-remove-medium
  blockdev: Add blockdev-insert-medium
  blockdev: Implement eject with basic operations
  blockdev: Implement change with basic operations
  block: Inquire tray state before tray-moved events
  qmp: Introduce blockdev-change-medium
  hmp: Use blockdev-change-medium for change command
  blockdev: read-only-mode for blockdev-change-medium
  hmp: Add read-only-mode option to change command
  iotests: Add test for change-related QMP commands

 block.c                        | 180 ++------
 block/accounting.c             |   8 -
 block/backup.c                 |  17 +-
 block/block-backend.c          | 387 +++++++++++++++--
 block/commit.c                 |   3 +-
 block/io.c                     |  10 +-
 block/mirror.c                 |  17 +-
 block/qapi.c                   |  36 +-
 block/raw-posix.c              | 230 +----------
 block/raw_bsd.c                |   6 -
 block/stream.c                 |   3 +-
 blockdev.c                     | 916 +++++++++++++++++++++++++++++------------
 blockjob.c                     |   5 +-
 hmp-commands.hx                |  20 +-
 hmp.c                          |  47 ++-
 hw/block/fdc.c                 |  20 +-
 hw/block/xen_disk.c            |   4 +-
 hw/usb/dev-storage.c           |  30 +-
 include/block/accounting.h     |   3 -
 include/block/block.h          |  16 +-
 include/block/block_int.h      |  25 +-
 include/qemu/typedefs.h        |   1 +
 include/sysemu/block-backend.h |  14 +-
 include/sysemu/blockdev.h      |   2 -
 migration/block.c              |   5 +
 monitor.c                      |   4 +
 qapi-schema.json               |   6 +-
 qapi/block-core.json           | 138 ++++++-
 qmp-commands.hx                | 213 +++++++++-
 qmp.c                          |   9 +-
 tests/fdc-test.c               |   4 +-
 tests/qemu-iotests/071         |  54 ++-
 tests/qemu-iotests/071.out     |  12 +-
 tests/qemu-iotests/081         |  18 +-
 tests/qemu-iotests/081.out     |   5 +-
 tests/qemu-iotests/087         |   2 +-
 tests/qemu-iotests/087.out     |   4 +-
 tests/qemu-iotests/118         | 638 ++++++++++++++++++++++++++++
 tests/qemu-iotests/118.out     |   5 +
 tests/qemu-iotests/group       |   1 +
 40 files changed, 2294 insertions(+), 824 deletions(-)
 create mode 100755 tests/qemu-iotests/118
 create mode 100644 tests/qemu-iotests/118.out

-- 
2.5.2

[Qemu-devel] [PATCH v5 01/38] block: Remove host floppy support

[Max Reitz]

It has been deprecated as of 2.3, so we can now remove it.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block/raw-posix.c    | 222 ++-------------------------------------------------
 qapi/block-core.json |   9 +--
 2 files changed, 9 insertions(+), 222 deletions(-)

diff --git a/block/raw-posix.c b/block/raw-posix.c
index 30df8ad..e650c9b 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -127,11 +127,6 @@ do { \
 
 #define FTYPE_FILE   0
 #define FTYPE_CD     1
-#define FTYPE_FD     2
-
-/* if the FD is not accessed during that time (in ns), we try to
-   reopen it to see if the disk has been changed */
-#define FD_OPEN_TIMEOUT (1000000000)
 
 #define MAX_BLOCKSIZE	4096
 
@@ -141,13 +136,6 @@ typedef struct BDRVRawState {
     int open_flags;
     size_t buf_align;
 
-#if defined(__linux__)
-    /* linux floppy specific */
-    int64_t fd_open_time;
-    int64_t fd_error_time;
-    int fd_got_error;
-    int fd_media_changed;
-#endif
 #ifdef CONFIG_LINUX_AIO
     int use_aio;
     void *aio_ctx;
@@ -626,7 +614,7 @@ static int raw_reopen_prepare(BDRVReopenState *state,
     }
 #endif
 
-    if (s->type == FTYPE_FD || s->type == FTYPE_CD) {
+    if (s->type == FTYPE_CD) {
         raw_s->open_flags |= O_NONBLOCK;
     }
 
@@ -2178,47 +2166,6 @@ static int hdev_open(BlockDriverState *bs, QDict *options, int flags,
 }
 
 #if defined(__linux__)
-/* Note: we do not have a reliable method to detect if the floppy is
-   present. The current method is to try to open the floppy at every
-   I/O and to keep it opened during a few hundreds of ms. */
-static int fd_open(BlockDriverState *bs)
-{
-    BDRVRawState *s = bs->opaque;
-    int last_media_present;
-
-    if (s->type != FTYPE_FD)
-        return 0;
-    last_media_present = (s->fd >= 0);
-    if (s->fd >= 0 &&
-        (qemu_clock_get_ns(QEMU_CLOCK_REALTIME) - s->fd_open_time) >= FD_OPEN_TIMEOUT) {
-        qemu_close(s->fd);
-        s->fd = -1;
-        DPRINTF("Floppy closed\n");
-    }
-    if (s->fd < 0) {
-        if (s->fd_got_error &&
-            (qemu_clock_get_ns(QEMU_CLOCK_REALTIME) - s->fd_error_time) < FD_OPEN_TIMEOUT) {
-            DPRINTF("No floppy (open delayed)\n");
-            return -EIO;
-        }
-        s->fd = qemu_open(bs->filename, s->open_flags & ~O_NONBLOCK);
-        if (s->fd < 0) {
-            s->fd_error_time = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
-            s->fd_got_error = 1;
-            if (last_media_present)
-                s->fd_media_changed = 1;
-            DPRINTF("No floppy\n");
-            return -EIO;
-        }
-        DPRINTF("Floppy opened\n");
-    }
-    if (!last_media_present)
-        s->fd_media_changed = 1;
-    s->fd_open_time = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
-    s->fd_got_error = 0;
-    return 0;
-}
-
 static int hdev_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
 {
     BDRVRawState *s = bs->opaque;
@@ -2247,8 +2194,8 @@ static BlockAIOCB *hdev_aio_ioctl(BlockDriverState *bs,
     pool = aio_get_thread_pool(bdrv_get_aio_context(bs));
     return thread_pool_submit_aio(pool, aio_worker, acb, cb, opaque);
 }
+#endif /* linux */
 
-#elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
 static int fd_open(BlockDriverState *bs)
 {
     BDRVRawState *s = bs->opaque;
@@ -2258,14 +2205,6 @@ static int fd_open(BlockDriverState *bs)
         return 0;
     return -EIO;
 }
-#else /* !linux && !FreeBSD */
-
-static int fd_open(BlockDriverState *bs)
-{
-    return 0;
-}
-
-#endif /* !linux && !FreeBSD */
 
 static coroutine_fn BlockAIOCB *hdev_aio_discard(BlockDriverState *bs,
     int64_t sector_num, int nb_sectors,
@@ -2309,14 +2248,13 @@ static int hdev_create(const char *filename, QemuOpts *opts,
     int64_t total_size = 0;
     bool has_prefix;
 
-    /* This function is used by all three protocol block drivers and therefore
-     * any of these three prefixes may be given.
+    /* This function is used by both protocol block drivers and therefore either
+     * of these prefixes may be given.
      * The return value has to be stored somewhere, otherwise this is an error
      * due to -Werror=unused-value. */
     has_prefix =
         strstart(filename, "host_device:", &filename) ||
-        strstart(filename, "host_cdrom:" , &filename) ||
-        strstart(filename, "host_floppy:", &filename);
+        strstart(filename, "host_cdrom:" , &filename);
 
     (void)has_prefix;
 
@@ -2396,155 +2334,6 @@ static BlockDriver bdrv_host_device = {
 #endif
 };
 
-#ifdef __linux__
-static void floppy_parse_filename(const char *filename, QDict *options,
-                                  Error **errp)
-{
-    /* The prefix is optional, just as for "file". */
-    strstart(filename, "host_floppy:", &filename);
-
-    qdict_put_obj(options, "filename", QOBJECT(qstring_from_str(filename)));
-}
-
-static int floppy_open(BlockDriverState *bs, QDict *options, int flags,
-                       Error **errp)
-{
-    BDRVRawState *s = bs->opaque;
-    Error *local_err = NULL;
-    int ret;
-
-    s->type = FTYPE_FD;
-
-    /* open will not fail even if no floppy is inserted, so add O_NONBLOCK */
-    ret = raw_open_common(bs, options, flags, O_NONBLOCK, &local_err);
-    if (ret) {
-        if (local_err) {
-            error_propagate(errp, local_err);
-        }
-        return ret;
-    }
-
-    /* close fd so that we can reopen it as needed */
-    qemu_close(s->fd);
-    s->fd = -1;
-    s->fd_media_changed = 1;
-
-    error_report("Host floppy pass-through is deprecated");
-    error_printf("Support for it will be removed in a future release.\n");
-    return 0;
-}
-
-static int floppy_probe_device(const char *filename)
-{
-    int fd, ret;
-    int prio = 0;
-    struct floppy_struct fdparam;
-    struct stat st;
-
-    if (strstart(filename, "/dev/fd", NULL) &&
-        !strstart(filename, "/dev/fdset/", NULL) &&
-        !strstart(filename, "/dev/fd/", NULL)) {
-        prio = 50;
-    }
-
-    fd = qemu_open(filename, O_RDONLY | O_NONBLOCK);
-    if (fd < 0) {
-        goto out;
-    }
-    ret = fstat(fd, &st);
-    if (ret == -1 || !S_ISBLK(st.st_mode)) {
-        goto outc;
-    }
-
-    /* Attempt to detect via a floppy specific ioctl */
-    ret = ioctl(fd, FDGETPRM, &fdparam);
-    if (ret >= 0)
-        prio = 100;
-
-outc:
-    qemu_close(fd);
-out:
-    return prio;
-}
-
-
-static int floppy_is_inserted(BlockDriverState *bs)
-{
-    return fd_open(bs) >= 0;
-}
-
-static int floppy_media_changed(BlockDriverState *bs)
-{
-    BDRVRawState *s = bs->opaque;
-    int ret;
-
-    /*
-     * XXX: we do not have a true media changed indication.
-     * It does not work if the floppy is changed without trying to read it.
-     */
-    fd_open(bs);
-    ret = s->fd_media_changed;
-    s->fd_media_changed = 0;
-    DPRINTF("Floppy changed=%d\n", ret);
-    return ret;
-}
-
-static void floppy_eject(BlockDriverState *bs, bool eject_flag)
-{
-    BDRVRawState *s = bs->opaque;
-    int fd;
-
-    if (s->fd >= 0) {
-        qemu_close(s->fd);
-        s->fd = -1;
-    }
-    fd = qemu_open(bs->filename, s->open_flags | O_NONBLOCK);
-    if (fd >= 0) {
-        if (ioctl(fd, FDEJECT, 0) < 0)
-            perror("FDEJECT");
-        qemu_close(fd);
-    }
-}
-
-static BlockDriver bdrv_host_floppy = {
-    .format_name        = "host_floppy",
-    .protocol_name      = "host_floppy",
-    .instance_size      = sizeof(BDRVRawState),
-    .bdrv_needs_filename = true,
-    .bdrv_probe_device	= floppy_probe_device,
-    .bdrv_parse_filename = floppy_parse_filename,
-    .bdrv_file_open     = floppy_open,
-    .bdrv_close         = raw_close,
-    .bdrv_reopen_prepare = raw_reopen_prepare,
-    .bdrv_reopen_commit  = raw_reopen_commit,
-    .bdrv_reopen_abort   = raw_reopen_abort,
-    .bdrv_create         = hdev_create,
-    .create_opts         = &raw_create_opts,
-
-    .bdrv_aio_readv     = raw_aio_readv,
-    .bdrv_aio_writev    = raw_aio_writev,
-    .bdrv_aio_flush	= raw_aio_flush,
-    .bdrv_refresh_limits = raw_refresh_limits,
-    .bdrv_io_plug = raw_aio_plug,
-    .bdrv_io_unplug = raw_aio_unplug,
-    .bdrv_flush_io_queue = raw_aio_flush_io_queue,
-
-    .bdrv_truncate      = raw_truncate,
-    .bdrv_getlength      = raw_getlength,
-    .has_variable_length = true,
-    .bdrv_get_allocated_file_size
-                        = raw_get_allocated_file_size,
-
-    .bdrv_detach_aio_context = raw_detach_aio_context,
-    .bdrv_attach_aio_context = raw_attach_aio_context,
-
-    /* removable device support */
-    .bdrv_is_inserted   = floppy_is_inserted,
-    .bdrv_media_changed = floppy_media_changed,
-    .bdrv_eject         = floppy_eject,
-};
-#endif
-
 #if defined(__linux__) || defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
 static void cdrom_parse_filename(const char *filename, QDict *options,
                                  Error **errp)
@@ -2822,7 +2611,6 @@ static void bdrv_file_init(void)
     bdrv_register(&bdrv_file);
     bdrv_register(&bdrv_host_device);
 #ifdef __linux__
-    bdrv_register(&bdrv_host_floppy);
     bdrv_register(&bdrv_host_cdrom);
 #endif
 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
diff --git a/qapi/block-core.json b/qapi/block-core.json
index bb2189e..c042561 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -215,10 +215,11 @@
 # @drv: the name of the block format used to open the backing device. As of
 #       0.14.0 this can be: 'blkdebug', 'bochs', 'cloop', 'cow', 'dmg',
 #       'file', 'file', 'ftp', 'ftps', 'host_cdrom', 'host_device',
-#       'host_floppy', 'http', 'https', 'nbd', 'parallels', 'qcow',
+#       'http', 'https', 'nbd', 'parallels', 'qcow',
 #       'qcow2', 'raw', 'tftp', 'vdi', 'vmdk', 'vpc', 'vvfat'
 #       2.2: 'archipelago' added, 'cow' dropped
 #       2.3: 'host_floppy' deprecated
+#       2.5: 'host_floppy' dropped
 #
 # @backing_file: #optional the name of the backing file (for copy-on-write)
 #
@@ -1373,15 +1374,14 @@
 #
 # Drivers that are supported in block device operations.
 #
-# @host_device, @host_cdrom, @host_floppy: Since 2.1
-# @host_floppy: deprecated since 2.3
+# @host_device, @host_cdrom: Since 2.1
 #
 # Since: 2.0
 ##
 { 'enum': 'BlockdevDriver',
   'data': [ 'archipelago', 'blkdebug', 'blkverify', 'bochs', 'cloop',
             'dmg', 'file', 'ftp', 'ftps', 'host_cdrom', 'host_device',
-            'host_floppy', 'http', 'https', 'null-aio', 'null-co', 'parallels',
+            'http', 'https', 'null-aio', 'null-co', 'parallels',
             'qcow', 'qcow2', 'qed', 'quorum', 'raw', 'tftp', 'vdi', 'vhdx',
             'vmdk', 'vpc', 'vvfat' ] }
 
@@ -1816,7 +1816,6 @@
 # TODO gluster: Wait for structured options
       'host_cdrom': 'BlockdevOptionsFile',
       'host_device':'BlockdevOptionsFile',
-      'host_floppy':'BlockdevOptionsFile',
       'http':       'BlockdevOptionsFile',
       'https':      'BlockdevOptionsFile',
 # TODO iscsi: Wait for structured options
-- 
2.5.2

[Qemu-devel] [PATCH v5 02/38] block: Set BDRV_O_INCOMING in bdrv_fill_options()

[Max Reitz]

This flag should not be set for the root BDS only, but for any BDS that
is being created while incoming migration is pending, so setting it is
moved from blockdev_init() to bdrv_fill_options().

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block.c    | 4 ++++
 blockdev.c | 4 ----
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/block.c b/block.c
index 6268e37..51d8c51 100644
--- a/block.c
+++ b/block.c
@@ -1076,6 +1076,10 @@ static int bdrv_fill_options(QDict **options, const char **pfilename,
         }
     }
 
+    if (runstate_check(RUN_STATE_INMIGRATE)) {
+        *flags |= BDRV_O_INCOMING;
+    }
+
     return 0;
 }
 
diff --git a/blockdev.c b/blockdev.c
index 32b04b4..ab6eaea 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -539,10 +539,6 @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
             bdrv_flags |= BDRV_O_COPY_ON_READ;
         }
 
-        if (runstate_check(RUN_STATE_INMIGRATE)) {
-            bdrv_flags |= BDRV_O_INCOMING;
-        }
-
         bdrv_flags |= ro ? 0 : BDRV_O_RDWR;
 
         blk = blk_new_open(qemu_opts_id(opts), file, NULL, bs_opts, bdrv_flags,
-- 
2.5.2

[Qemu-devel] [PATCH v5 03/38] blockdev: Allow creation of BDS trees without BB

[Max Reitz]

If the "id" field is missing from the options given to blockdev-add,
just omit the BlockBackend and create the BlockDriverState tree alone.

However, if "id" is missing, "node-name" must be specified; otherwise,
the BDS tree would no longer be accessible.

Many BDS options which are not parsed by bdrv_open() (like caching)
cannot be specified for these BB-less BDS trees yet. A future patch will
remove this limitation.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 blockdev.c                 | 44 +++++++++++++++++++++++++++++++-------------
 qapi/block-core.json       | 13 +++++++++----
 tests/qemu-iotests/087     |  2 +-
 tests/qemu-iotests/087.out |  4 ++--
 4 files changed, 43 insertions(+), 20 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index ab6eaea..013583b 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -3028,17 +3028,12 @@ out:
 void qmp_blockdev_add(BlockdevOptions *options, Error **errp)
 {
     QmpOutputVisitor *ov = qmp_output_visitor_new();
-    BlockBackend *blk;
+    BlockDriverState *bs;
+    BlockBackend *blk = NULL;
     QObject *obj;
     QDict *qdict;
     Error *local_err = NULL;
 
-    /* Require an ID in the top level */
-    if (!options->has_id) {
-        error_setg(errp, "Block device needs an ID");
-        goto fail;
-    }
-
     /* TODO Sort it out in raw-posix and drive_new(): Reject aio=native with
      * cache.direct=false instead of silently switching to aio=threads, except
      * when called from drive_new().
@@ -3066,14 +3061,37 @@ void qmp_blockdev_add(BlockdevOptions *options, Error **errp)
 
     qdict_flatten(qdict);
 
-    blk = blockdev_init(NULL, qdict, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
-        goto fail;
+    if (options->has_id) {
+        blk = blockdev_init(NULL, qdict, &local_err);
+        if (local_err) {
+            error_propagate(errp, local_err);
+            goto fail;
+        }
+
+        bs = blk_bs(blk);
+    } else {
+        int ret;
+
+        if (!qdict_get_try_str(qdict, "node-name")) {
+            error_setg(errp, "'id' and/or 'node-name' need to be specified for "
+                       "the root node");
+            goto fail;
+        }
+
+        bs = NULL;
+        ret = bdrv_open(&bs, NULL, NULL, qdict, BDRV_O_RDWR | BDRV_O_CACHE_WB,
+                        errp);
+        if (ret < 0) {
+            goto fail;
+        }
     }
 
-    if (bdrv_key_required(blk_bs(blk))) {
-        blk_unref(blk);
+    if (bs && bdrv_key_required(bs)) {
+        if (blk) {
+            blk_unref(blk);
+        } else {
+            bdrv_unref(bs);
+        }
         error_setg(errp, "blockdev-add doesn't support encrypted devices");
         goto fail;
     }
diff --git a/qapi/block-core.json b/qapi/block-core.json
index c042561..425fdab 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1393,9 +1393,12 @@
 #
 # @driver:        block driver name
 # @id:            #optional id by which the new block device can be referred to.
-#                 This is a required option on the top level of blockdev-add, and
-#                 currently not allowed on any other level.
-# @node-name:     #optional the name of a block driver state node (Since 2.0)
+#                 This option is only allowed on the top level of blockdev-add.
+#                 A BlockBackend will be created by blockdev-add if and only if
+#                 this option is given.
+# @node-name:     #optional the name of a block driver state node (Since 2.0).
+#                 This option is required on the top level of blockdev-add if
+#                 the @id option is not given there.
 # @discard:       #optional discard-related options (default: ignore)
 # @cache:         #optional cache-related options
 # @aio:           #optional AIO backend (default: threads)
@@ -1859,7 +1862,9 @@
 ##
 # @blockdev-add:
 #
-# Creates a new block device.
+# Creates a new block device. If the @id option is given at the top level, a
+# BlockBackend will be created; otherwise, @node-name is mandatory at the top
+# level and no BlockBackend will be created.
 #
 # This command is still a work in progress.  It doesn't support all
 # block drivers, it lacks a matching blockdev-del, and more.  Stay
diff --git a/tests/qemu-iotests/087 b/tests/qemu-iotests/087
index 8694749..af44299 100755
--- a/tests/qemu-iotests/087
+++ b/tests/qemu-iotests/087
@@ -54,7 +54,7 @@ size=128M
 _make_test_img $size
 
 echo
-echo === Missing ID ===
+echo === Missing ID and node-name ===
 echo
 
 run_qemu <<EOF
diff --git a/tests/qemu-iotests/087.out b/tests/qemu-iotests/087.out
index c509a40..7d62cd5 100644
--- a/tests/qemu-iotests/087.out
+++ b/tests/qemu-iotests/087.out
@@ -1,12 +1,12 @@
 QA output created by 087
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
 
-=== Missing ID ===
+=== Missing ID and node-name ===
 
 Testing:
 QMP_VERSION
 {"return": {}}
-{"error": {"class": "GenericError", "desc": "Block device needs an ID"}}
+{"error": {"class": "GenericError", "desc": "'id' and/or 'node-name' need to be specified for the root node"}}
 {"return": {}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "SHUTDOWN"}
 
-- 
2.5.2

[Qemu-devel] [PATCH v5 04/38] iotests: Only create BB if necessary

[Max Reitz]

Tests 071 and 081 test giving references in blockdev-add. It is not
necessary to create a BlockBackend here, so omit it.

While at it, fix up some blockdev-add invocations in the vicinity
(s/raw/$IMGFMT/ in 081, drop the format BDS for blkverify's raw child in
071).

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 tests/qemu-iotests/071     | 54 ++++++++++++++++++++++++++++++++++++++--------
 tests/qemu-iotests/071.out | 12 +++++++----
 tests/qemu-iotests/081     | 18 +++++++++++++---
 tests/qemu-iotests/081.out |  5 +++--
 4 files changed, 71 insertions(+), 18 deletions(-)

diff --git a/tests/qemu-iotests/071 b/tests/qemu-iotests/071
index 9eaa49b..92ab991 100755
--- a/tests/qemu-iotests/071
+++ b/tests/qemu-iotests/071
@@ -104,11 +104,20 @@ echo
 echo "=== Testing blkdebug on existing block device ==="
 echo
 
-run_qemu -drive "file=$TEST_IMG,format=raw,if=none,id=drive0" <<EOF
+run_qemu <<EOF
 { "execute": "qmp_capabilities" }
 { "execute": "blockdev-add",
     "arguments": {
         "options": {
+            "node-name": "drive0",
+            "driver": "file",
+            "filename": "$TEST_IMG"
+        }
+    }
+}
+{ "execute": "blockdev-add",
+    "arguments": {
+        "options": {
             "driver": "$IMGFMT",
             "id": "drive0-debug",
             "file": {
@@ -133,20 +142,29 @@ echo
 echo "=== Testing blkverify on existing block device ==="
 echo
 
-run_qemu -drive "file=$TEST_IMG,format=$IMGFMT,if=none,id=drive0" <<EOF
+run_qemu <<EOF
 { "execute": "qmp_capabilities" }
 { "execute": "blockdev-add",
     "arguments": {
         "options": {
+            "node-name": "drive0",
+            "driver": "$IMGFMT",
+            "file": {
+                "driver": "file",
+                "filename": "$TEST_IMG"
+            }
+        }
+    }
+}
+{ "execute": "blockdev-add",
+    "arguments": {
+        "options": {
             "driver": "blkverify",
             "id": "drive0-verify",
             "test": "drive0",
             "raw": {
-                "driver": "raw",
-                "file": {
-                    "driver": "file",
-                    "filename": "$TEST_IMG.base"
-                }
+                "driver": "file",
+                "filename": "$TEST_IMG.base"
             }
         }
     }
@@ -163,11 +181,20 @@ echo
 echo "=== Testing blkverify on existing raw block device ==="
 echo
 
-run_qemu -drive "file=$TEST_IMG.base,format=raw,if=none,id=drive0" <<EOF
+run_qemu <<EOF
 { "execute": "qmp_capabilities" }
 { "execute": "blockdev-add",
     "arguments": {
         "options": {
+            "node-name": "drive0",
+            "driver": "file",
+            "filename": "$TEST_IMG.base"
+        }
+    }
+}
+{ "execute": "blockdev-add",
+    "arguments": {
+        "options": {
             "driver": "blkverify",
             "id": "drive0-verify",
             "test": {
@@ -193,11 +220,20 @@ echo
 echo "=== Testing blkdebug's set-state through QMP ==="
 echo
 
-run_qemu -drive "file=$TEST_IMG,format=raw,if=none,id=drive0" <<EOF
+run_qemu <<EOF
 { "execute": "qmp_capabilities" }
 { "execute": "blockdev-add",
     "arguments": {
         "options": {
+            "node-name": "drive0",
+            "driver": "file",
+            "filename": "$TEST_IMG"
+        }
+    }
+}
+{ "execute": "blockdev-add",
+    "arguments": {
+        "options": {
             "driver": "$IMGFMT",
             "id": "drive0-debug",
             "file": {
diff --git a/tests/qemu-iotests/071.out b/tests/qemu-iotests/071.out
index 8d2095a..2b40ead 100644
--- a/tests/qemu-iotests/071.out
+++ b/tests/qemu-iotests/071.out
@@ -42,10 +42,11 @@ read failed: Input/output error
 
 === Testing blkdebug on existing block device ===
 
-Testing: -drive file=TEST_DIR/t.IMGFMT,format=raw,if=none,id=drive0
+Testing:
 QMP_VERSION
 {"return": {}}
 {"return": {}}
+{"return": {}}
 read failed: Input/output error
 {"return": ""}
 {"return": {}}
@@ -56,28 +57,31 @@ QEMU_PROG: Failed to flush the refcount block cache: Input/output error
 
 === Testing blkverify on existing block device ===
 
-Testing: -drive file=TEST_DIR/t.IMGFMT,format=IMGFMT,if=none,id=drive0
+Testing:
 QMP_VERSION
 {"return": {}}
 {"return": {}}
+{"return": {}}
 blkverify: read sector_num=0 nb_sectors=1 contents mismatch in sector 0
 
 
 === Testing blkverify on existing raw block device ===
 
-Testing: -drive file=TEST_DIR/t.IMGFMT.base,format=raw,if=none,id=drive0
+Testing:
 QMP_VERSION
 {"return": {}}
 {"return": {}}
+{"return": {}}
 blkverify: read sector_num=0 nb_sectors=1 contents mismatch in sector 0
 
 
 === Testing blkdebug's set-state through QMP ===
 
-Testing: -drive file=TEST_DIR/t.IMGFMT,format=raw,if=none,id=drive0
+Testing:
 QMP_VERSION
 {"return": {}}
 {"return": {}}
+{"return": {}}
 read 512/512 bytes at offset 0
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 {"return": ""}
diff --git a/tests/qemu-iotests/081 b/tests/qemu-iotests/081
index d9b042c..775e356 100755
--- a/tests/qemu-iotests/081
+++ b/tests/qemu-iotests/081
@@ -101,17 +101,29 @@ $QEMU_IO -c "open -o $quorum" -c "read -P 0x32 0 $size" | _filter_qemu_io
 echo
 echo "== checking mixed reference/option specification =="
 
-run_qemu -drive "file=$TEST_DIR/2.raw,format=$IMGFMT,if=none,id=drive2" <<EOF
+run_qemu <<EOF
 { "execute": "qmp_capabilities" }
 { "execute": "blockdev-add",
     "arguments": {
         "options": {
+            "node-name": "drive2",
+            "driver": "$IMGFMT",
+            "file": {
+                "driver": "file",
+                "filename": "$TEST_DIR/2.raw"
+            }
+        }
+    }
+}
+{ "execute": "blockdev-add",
+    "arguments": {
+        "options": {
             "driver": "quorum",
             "id": "drive0-quorum",
             "vote-threshold": 2,
             "children": [
                 {
-                    "driver": "raw",
+                    "driver": "$IMGFMT",
                     "file": {
                         "driver": "file",
                         "filename": "$TEST_DIR/1.raw"
@@ -119,7 +131,7 @@ run_qemu -drive "file=$TEST_DIR/2.raw,format=$IMGFMT,if=none,id=drive2" <<EOF
                 },
                 "drive2",
                 {
-                    "driver": "raw",
+                    "driver": "$IMGFMT",
                     "file": {
                         "driver": "file",
                         "filename": "$TEST_DIR/3.raw"
diff --git a/tests/qemu-iotests/081.out b/tests/qemu-iotests/081.out
index 692c4a4..7063231 100644
--- a/tests/qemu-iotests/081.out
+++ b/tests/qemu-iotests/081.out
@@ -26,11 +26,12 @@ read 10485760/10485760 bytes at offset 0
 10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 
 == checking mixed reference/option specification ==
-Testing: -drive file=TEST_DIR/2.IMGFMT,format=IMGFMT,if=none,id=drive2
+Testing:
 QMP_VERSION
 {"return": {}}
 {"return": {}}
-{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "QUORUM_REPORT_BAD", "data": {"node-name": "", "sectors-count": 20480, "sector-num": 0}}
+{"return": {}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "QUORUM_REPORT_BAD", "data": {"node-name": "drive2", "sectors-count": 20480, "sector-num": 0}}
 read 10485760/10485760 bytes at offset 0
 10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 {"return": ""}
-- 
2.5.2

[Qemu-devel] [PATCH v5 05/38] block: Make bdrv_is_inserted() return a bool

[Max Reitz]

Make bdrv_is_inserted(), blk_is_inserted(), and the callback
BlockDriver.bdrv_is_inserted() return a bool.

Suggested-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
---
 block.c                        | 12 +++++++-----
 block/block-backend.c          |  2 +-
 block/raw-posix.c              |  8 +++-----
 block/raw_bsd.c                |  2 +-
 include/block/block.h          |  2 +-
 include/block/block_int.h      |  2 +-
 include/sysemu/block-backend.h |  2 +-
 7 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/block.c b/block.c
index 51d8c51..4a089e6 100644
--- a/block.c
+++ b/block.c
@@ -3244,14 +3244,16 @@ void bdrv_invalidate_cache_all(Error **errp)
 /**
  * Return TRUE if the media is present
  */
-int bdrv_is_inserted(BlockDriverState *bs)
+bool bdrv_is_inserted(BlockDriverState *bs)
 {
     BlockDriver *drv = bs->drv;
 
-    if (!drv)
-        return 0;
-    if (!drv->bdrv_is_inserted)
-        return 1;
+    if (!drv) {
+        return false;
+    }
+    if (!drv->bdrv_is_inserted) {
+        return true;
+    }
     return drv->bdrv_is_inserted(bs);
 }
 
diff --git a/block/block-backend.c b/block/block-backend.c
index c2e8732..5ad2dd4 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -752,7 +752,7 @@ void blk_invalidate_cache(BlockBackend *blk, Error **errp)
     bdrv_invalidate_cache(blk->bs, errp);
 }
 
-int blk_is_inserted(BlockBackend *blk)
+bool blk_is_inserted(BlockBackend *blk)
 {
     return bdrv_is_inserted(blk->bs);
 }
diff --git a/block/raw-posix.c b/block/raw-posix.c
index e650c9b..d6e88e3 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -2389,15 +2389,13 @@ out:
     return prio;
 }
 
-static int cdrom_is_inserted(BlockDriverState *bs)
+static bool cdrom_is_inserted(BlockDriverState *bs)
 {
     BDRVRawState *s = bs->opaque;
     int ret;
 
     ret = ioctl(s->fd, CDROM_DRIVE_STATUS, CDSL_CURRENT);
-    if (ret == CDS_DISC_OK)
-        return 1;
-    return 0;
+    return ret == CDS_DISC_OK;
 }
 
 static void cdrom_eject(BlockDriverState *bs, bool eject_flag)
@@ -2523,7 +2521,7 @@ static int cdrom_reopen(BlockDriverState *bs)
     return 0;
 }
 
-static int cdrom_is_inserted(BlockDriverState *bs)
+static bool cdrom_is_inserted(BlockDriverState *bs)
 {
     return raw_getlength(bs) > 0;
 }
diff --git a/block/raw_bsd.c b/block/raw_bsd.c
index e3d2d04..d718583 100644
--- a/block/raw_bsd.c
+++ b/block/raw_bsd.c
@@ -154,7 +154,7 @@ static int raw_truncate(BlockDriverState *bs, int64_t offset)
     return bdrv_truncate(bs->file, offset);
 }
 
-static int raw_is_inserted(BlockDriverState *bs)
+static bool raw_is_inserted(BlockDriverState *bs)
 {
     return bdrv_is_inserted(bs->file);
 }
diff --git a/include/block/block.h b/include/block/block.h
index ef67353..c9cc62b 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -397,7 +397,7 @@ int bdrv_is_read_only(BlockDriverState *bs);
 int bdrv_is_sg(BlockDriverState *bs);
 int bdrv_enable_write_cache(BlockDriverState *bs);
 void bdrv_set_enable_write_cache(BlockDriverState *bs, bool wce);
-int bdrv_is_inserted(BlockDriverState *bs);
+bool bdrv_is_inserted(BlockDriverState *bs);
 int bdrv_media_changed(BlockDriverState *bs);
 void bdrv_lock_medium(BlockDriverState *bs, bool locked);
 void bdrv_eject(BlockDriverState *bs, bool eject_flag);
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 14ad4c3..f3b3354 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -213,7 +213,7 @@ struct BlockDriver {
         const char *backing_file, const char *backing_fmt);
 
     /* removable device specific */
-    int (*bdrv_is_inserted)(BlockDriverState *bs);
+    bool (*bdrv_is_inserted)(BlockDriverState *bs);
     int (*bdrv_media_changed)(BlockDriverState *bs);
     void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
     void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
index 8fc960f..8f2bf10 100644
--- a/include/sysemu/block-backend.h
+++ b/include/sysemu/block-backend.h
@@ -130,7 +130,7 @@ int blk_is_sg(BlockBackend *blk);
 int blk_enable_write_cache(BlockBackend *blk);
 void blk_set_enable_write_cache(BlockBackend *blk, bool wce);
 void blk_invalidate_cache(BlockBackend *blk, Error **errp);
-int blk_is_inserted(BlockBackend *blk);
+bool blk_is_inserted(BlockBackend *blk);
 void blk_lock_medium(BlockBackend *blk, bool locked);
 void blk_eject(BlockBackend *blk, bool eject_flag);
 int blk_get_flags(BlockBackend *blk);
-- 
2.5.2

[Qemu-devel] [PATCH v5 06/38] block: Add blk_is_available()

[Max Reitz]

blk_is_available() returns true iff the BDS is inserted (which means
blk_bs() is not NULL and bdrv_is_inserted() returns true) and if the
tray of the guest device is closed.

blk_is_inserted() is changed to return true only if blk_bs() is not
NULL.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
---
 block/block-backend.c          | 7 ++++++-
 include/sysemu/block-backend.h | 1 +
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/block/block-backend.c b/block/block-backend.c
index 5ad2dd4..cf30cad 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -754,7 +754,12 @@ void blk_invalidate_cache(BlockBackend *blk, Error **errp)
 
 bool blk_is_inserted(BlockBackend *blk)
 {
-    return bdrv_is_inserted(blk->bs);
+    return blk->bs && bdrv_is_inserted(blk->bs);
+}
+
+bool blk_is_available(BlockBackend *blk)
+{
+    return blk_is_inserted(blk) && !blk_dev_is_tray_open(blk);
 }
 
 void blk_lock_medium(BlockBackend *blk, bool locked)
diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
index 8f2bf10..1e19d1b 100644
--- a/include/sysemu/block-backend.h
+++ b/include/sysemu/block-backend.h
@@ -131,6 +131,7 @@ int 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);
-- 
2.5.2

[Qemu-devel] [PATCH v5 07/38] block: Make bdrv_is_inserted() recursive

[Max Reitz]

If bdrv_is_inserted() is called on the top level BDS, it should make
sure all nodes in the BDS tree are actually inserted.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/block.c b/block.c
index 4a089e6..c4fa299 100644
--- a/block.c
+++ b/block.c
@@ -3247,14 +3247,20 @@ void bdrv_invalidate_cache_all(Error **errp)
 bool bdrv_is_inserted(BlockDriverState *bs)
 {
     BlockDriver *drv = bs->drv;
+    BdrvChild *child;
 
     if (!drv) {
         return false;
     }
-    if (!drv->bdrv_is_inserted) {
-        return true;
+    if (drv->bdrv_is_inserted) {
+        return drv->bdrv_is_inserted(bs);
     }
-    return drv->bdrv_is_inserted(bs);
+    QLIST_FOREACH(child, &bs->children, next) {
+        if (!bdrv_is_inserted(child->bs)) {
+            return false;
+        }
+    }
+    return true;
 }
 
 /**
-- 
2.5.2

[Qemu-devel] [PATCH v5 08/38] block/raw_bsd: Drop raw_is_inserted()

[Max Reitz]

With the new automatically-recursive implementation of
bdrv_is_inserted() checking by default whether all the children of a BDS
are inserted, we can drop raw's own implementation.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block/raw_bsd.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/block/raw_bsd.c b/block/raw_bsd.c
index d718583..891a1fa 100644
--- a/block/raw_bsd.c
+++ b/block/raw_bsd.c
@@ -154,11 +154,6 @@ static int raw_truncate(BlockDriverState *bs, int64_t offset)
     return bdrv_truncate(bs->file, offset);
 }
 
-static bool raw_is_inserted(BlockDriverState *bs)
-{
-    return bdrv_is_inserted(bs->file);
-}
-
 static int raw_media_changed(BlockDriverState *bs)
 {
     return bdrv_media_changed(bs->file);
@@ -264,7 +259,6 @@ BlockDriver bdrv_raw = {
     .bdrv_refresh_limits  = &raw_refresh_limits,
     .bdrv_probe_blocksizes = &raw_probe_blocksizes,
     .bdrv_probe_geometry  = &raw_probe_geometry,
-    .bdrv_is_inserted     = &raw_is_inserted,
     .bdrv_media_changed   = &raw_media_changed,
     .bdrv_eject           = &raw_eject,
     .bdrv_lock_medium     = &raw_lock_medium,
-- 
2.5.2

[Qemu-devel] [PATCH v5 09/38] block: Invoke change media CB before NULLing drv

[Max Reitz]

In order to handle host device passthrough, some guest device models
may call blk_is_inserted() to check whether the medium is inserted on
the host, when checking the guest tray status.

This tray status is inquired by blk_dev_change_media_cb(); because
bdrv_is_inserted() (invoked by blk_is_inserted()) always returns 0 for
BDS with drv set to NULL, blk_dev_change_media_cb() should therefore be
called before drv is set to NULL.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
---
 block.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/block.c b/block.c
index c4fa299..661c621 100644
--- a/block.c
+++ b/block.c
@@ -1916,6 +1916,10 @@ void bdrv_close(BlockDriverState *bs)
     bdrv_drain(bs); /* in case flush left pending I/O */
     notifier_list_notify(&bs->close_notifiers, bs);
 
+    if (bs->blk) {
+        blk_dev_change_media_cb(bs->blk, false);
+    }
+
     if (bs->drv) {
         BdrvChild *child, *next;
 
@@ -1958,10 +1962,6 @@ void bdrv_close(BlockDriverState *bs)
         }
     }
 
-    if (bs->blk) {
-        blk_dev_change_media_cb(bs->blk, false);
-    }
-
     /*throttling disk I/O limits*/
     if (bs->io_limits_enabled) {
         bdrv_io_limits_disable(bs);
-- 
2.5.2

[Qemu-devel] [PATCH v5 10/38] hw/block/fdc: Implement tray status

[Max Reitz]

The tray of an FDD is open iff there is no medium inserted (there are
only two states for an FDD: "medium inserted" or "no medium inserted").

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 hw/block/fdc.c   | 20 ++++++++++++++++----
 tests/fdc-test.c |  4 +---
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/hw/block/fdc.c b/hw/block/fdc.c
index 6686a72..4292ece 100644
--- a/hw/block/fdc.c
+++ b/hw/block/fdc.c
@@ -192,6 +192,8 @@ typedef struct FDrive {
     uint8_t ro;               /* Is read-only           */
     uint8_t media_changed;    /* Is media changed       */
     uint8_t media_rate;       /* Data rate of medium    */
+
+    bool media_inserted;      /* Is there a medium in the tray */
 } FDrive;
 
 static void fd_init(FDrive *drv)
@@ -261,7 +263,7 @@ static int fd_seek(FDrive *drv, uint8_t head, uint8_t track, uint8_t sect,
 #endif
         drv->head = head;
         if (drv->track != track) {
-            if (drv->blk != NULL && blk_is_inserted(drv->blk)) {
+            if (drv->media_inserted) {
                 drv->media_changed = 0;
             }
             ret = 1;
@@ -270,7 +272,7 @@ static int fd_seek(FDrive *drv, uint8_t head, uint8_t track, uint8_t sect,
         drv->sect = sect;
     }
 
-    if (drv->blk == NULL || !blk_is_inserted(drv->blk)) {
+    if (!drv->media_inserted) {
         ret = 2;
     }
 
@@ -296,7 +298,7 @@ static void fd_revalidate(FDrive *drv)
         ro = blk_is_read_only(drv->blk);
         pick_geometry(drv->blk, &nb_heads, &max_track,
                       &last_sect, drv->drive, &drive, &rate);
-        if (!blk_is_inserted(drv->blk)) {
+        if (!drv->media_inserted) {
             FLOPPY_DPRINTF("No disk in drive\n");
         } else {
             FLOPPY_DPRINTF("Floppy disk (%d h %d t %d s) %s\n", nb_heads,
@@ -692,7 +694,7 @@ static bool fdrive_media_changed_needed(void *opaque)
 {
     FDrive *drive = opaque;
 
-    return (drive->blk != NULL && drive->media_changed != 1);
+    return (drive->media_inserted && drive->media_changed != 1);
 }
 
 static const VMStateDescription vmstate_fdrive_media_changed = {
@@ -2184,12 +2186,21 @@ static void fdctrl_change_cb(void *opaque, bool load)
 {
     FDrive *drive = opaque;
 
+    drive->media_inserted = load && drive->blk && blk_is_inserted(drive->blk);
+
     drive->media_changed = 1;
     fd_revalidate(drive);
 }
 
+static bool fdctrl_is_tray_open(void *opaque)
+{
+    FDrive *drive = opaque;
+    return !drive->media_inserted;
+}
+
 static const BlockDevOps fdctrl_block_ops = {
     .change_media_cb = fdctrl_change_cb,
+    .is_tray_open = fdctrl_is_tray_open,
 };
 
 /* Init functions */
@@ -2217,6 +2228,7 @@ static void fdctrl_connect_drives(FDCtrl *fdctrl, Error **errp)
         fdctrl_change_cb(drive, 0);
         if (drive->blk) {
             blk_set_dev_ops(drive->blk, &fdctrl_block_ops, drive);
+            drive->media_inserted = blk_is_inserted(drive->blk);
         }
     }
 }
diff --git a/tests/fdc-test.c b/tests/fdc-test.c
index 416394f..b5a4696 100644
--- a/tests/fdc-test.c
+++ b/tests/fdc-test.c
@@ -304,9 +304,7 @@ static void test_media_insert(void)
     qmp_discard_response("{'execute':'change', 'arguments':{"
                          " 'device':'floppy0', 'target': %s, 'arg': 'raw' }}",
                          test_image);
-    qmp_discard_response(""); /* ignore event
-                                 (FIXME open -> open transition?!) */
-    qmp_discard_response(""); /* ignore event */
+    qmp_discard_response(""); /* ignore event (open -> close) */
 
     dir = inb(FLOPPY_BASE + reg_dir);
     assert_bit_set(dir, DSKCHG);
-- 
2.5.2

[Qemu-devel] [PATCH v5 11/38] hw/usb-storage: Check whether BB is inserted

[Max Reitz]

Only call bdrv_add_key() on the BlockDriverState if it is not NULL.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
---
 hw/usb/dev-storage.c | 30 ++++++++++++++++--------------
 1 file changed, 16 insertions(+), 14 deletions(-)

diff --git a/hw/usb/dev-storage.c b/hw/usb/dev-storage.c
index 9a4e7dc..597d8fd 100644
--- a/hw/usb/dev-storage.c
+++ b/hw/usb/dev-storage.c
@@ -613,20 +613,22 @@ static void usb_msd_realize_storage(USBDevice *dev, Error **errp)
         return;
     }
 
-    bdrv_add_key(blk_bs(blk), NULL, &err);
-    if (err) {
-        if (monitor_cur_is_qmp()) {
-            error_propagate(errp, err);
-            return;
-        }
-        error_free(err);
-        err = NULL;
-        if (cur_mon) {
-            monitor_read_bdrv_key_start(cur_mon, blk_bs(blk),
-                                        usb_msd_password_cb, s);
-            s->dev.auto_attach = 0;
-        } else {
-            autostart = 0;
+    if (blk_bs(blk)) {
+        bdrv_add_key(blk_bs(blk), NULL, &err);
+        if (err) {
+            if (monitor_cur_is_qmp()) {
+                error_propagate(errp, err);
+                return;
+            }
+            error_free(err);
+            err = NULL;
+            if (cur_mon) {
+                monitor_read_bdrv_key_start(cur_mon, blk_bs(blk),
+                                            usb_msd_password_cb, s);
+                s->dev.auto_attach = 0;
+            } else {
+                autostart = 0;
+            }
         }
     }
 
-- 
2.5.2

[Qemu-devel] [PATCH v5 12/38] block: Fix BB AIOCB AioContext without BDS

[Max Reitz]

Fix the BlockBackend's AIOCB AioContext for aborting AIO in case there
is no BDS. If there is no implementation of AIOCBInfo::get_aio_context()
the AioContext is derived from the BDS the AIOCB belongs to. If that BDS
is NULL (because it has been removed from the BB) this will not work.

This patch makes blk_get_aio_context() fall back to the main loop
context if the BDS pointer is NULL and implements
AIOCBInfo::get_aio_context() (blk_aiocb_get_aio_context()) which invokes
blk_get_aio_context().

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
---
 block/block-backend.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/block/block-backend.c b/block/block-backend.c
index cf30cad..501130b 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -18,6 +18,8 @@
 /* Number of coroutines to reserve per attached device model */
 #define COROUTINE_POOL_RESERVATION 64
 
+static AioContext *blk_aiocb_get_aio_context(BlockAIOCB *acb);
+
 struct BlockBackend {
     char *name;
     int refcnt;
@@ -34,10 +36,12 @@ struct BlockBackend {
 typedef struct BlockBackendAIOCB {
     BlockAIOCB common;
     QEMUBH *bh;
+    BlockBackend *blk;
     int ret;
 } BlockBackendAIOCB;
 
 static const AIOCBInfo block_backend_aiocb_info = {
+    .get_aio_context = blk_aiocb_get_aio_context,
     .aiocb_size = sizeof(BlockBackendAIOCB),
 };
 
@@ -541,6 +545,7 @@ static BlockAIOCB *abort_aio_request(BlockBackend *blk, BlockCompletionFunc *cb,
     QEMUBH *bh;
 
     acb = blk_aio_get(&block_backend_aiocb_info, blk, cb, opaque);
+    acb->blk = blk;
     acb->ret = ret;
 
     bh = aio_bh_new(blk_get_aio_context(blk), error_callback_bh, acb);
@@ -814,7 +819,17 @@ void blk_op_unblock_all(BlockBackend *blk, Error *reason)
 
 AioContext *blk_get_aio_context(BlockBackend *blk)
 {
-    return bdrv_get_aio_context(blk->bs);
+    if (blk->bs) {
+        return bdrv_get_aio_context(blk->bs);
+    } else {
+        return qemu_get_aio_context();
+    }
+}
+
+static AioContext *blk_aiocb_get_aio_context(BlockAIOCB *acb)
+{
+    BlockBackendAIOCB *blk_acb = DO_UPCAST(BlockBackendAIOCB, common, acb);
+    return blk_get_aio_context(blk_acb->blk);
 }
 
 void blk_set_aio_context(BlockBackend *blk, AioContext *new_context)
-- 
2.5.2

[Qemu-devel] [PATCH v5 13/38] block: Move guest_block_size into BlockBackend

[Max Reitz]

guest_block_size is a guest device property so it should be moved into
the interface between block layer and guest devices, which is the
BlockBackend.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
---
 block.c                   | 7 -------
 block/block-backend.c     | 7 +++++--
 include/block/block.h     | 1 -
 include/block/block_int.h | 3 ---
 4 files changed, 5 insertions(+), 13 deletions(-)

diff --git a/block.c b/block.c
index 661c621..55357c4 100644
--- a/block.c
+++ b/block.c
@@ -852,7 +852,6 @@ static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file,
         goto fail_opts;
     }
 
-    bs->guest_block_size = 512;
     bs->request_alignment = 512;
     bs->zero_beyond_eof = true;
     open_flags = bdrv_open_flags(bs, flags);
@@ -2021,7 +2020,6 @@ static void bdrv_move_feature_fields(BlockDriverState *bs_dest,
     /* move some fields that need to stay attached to the device */
 
     /* dev info */
-    bs_dest->guest_block_size   = bs_src->guest_block_size;
     bs_dest->copy_on_read       = bs_src->copy_on_read;
 
     bs_dest->enable_write_cache = bs_src->enable_write_cache;
@@ -3311,11 +3309,6 @@ void bdrv_lock_medium(BlockDriverState *bs, bool locked)
     }
 }
 
-void bdrv_set_guest_block_size(BlockDriverState *bs, int align)
-{
-    bs->guest_block_size = align;
-}
-
 BdrvDirtyBitmap *bdrv_find_dirty_bitmap(BlockDriverState *bs, const char *name)
 {
     BdrvDirtyBitmap *bm;
diff --git a/block/block-backend.c b/block/block-backend.c
index 501130b..ff862ad 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -31,6 +31,9 @@ struct BlockBackend {
     /* TODO change to DeviceState when all users are qdevified */
     const BlockDevOps *dev_ops;
     void *dev_opaque;
+
+    /* the block size for which the guest device expects atomicity */
+    int guest_block_size;
 };
 
 typedef struct BlockBackendAIOCB {
@@ -334,7 +337,7 @@ void blk_detach_dev(BlockBackend *blk, void *dev)
     blk->dev = NULL;
     blk->dev_ops = NULL;
     blk->dev_opaque = NULL;
-    bdrv_set_guest_block_size(blk->bs, 512);
+    blk->guest_block_size = 512;
     blk_unref(blk);
 }
 
@@ -789,7 +792,7 @@ int blk_get_max_transfer_length(BlockBackend *blk)
 
 void blk_set_guest_block_size(BlockBackend *blk, int align)
 {
-    bdrv_set_guest_block_size(blk->bs, align);
+    blk->guest_block_size = align;
 }
 
 void *blk_blockalign(BlockBackend *blk, size_t size)
diff --git a/include/block/block.h b/include/block/block.h
index c9cc62b..3e818f4 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -464,7 +464,6 @@ void bdrv_img_create(const char *filename, const char *fmt,
 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 bdrv_set_guest_block_size(BlockDriverState *bs, int align);
 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);
diff --git a/include/block/block_int.h b/include/block/block_int.h
index f3b3354..b7e1e16 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -412,9 +412,6 @@ struct BlockDriverState {
     /* Alignment requirement for offset/length of I/O requests */
     unsigned int request_alignment;
 
-    /* the block size for which the guest device expects atomicity */
-    int guest_block_size;
-
     /* do we need to tell the quest if we have a volatile write cache? */
     int enable_write_cache;
 
-- 
2.5.2

[Qemu-devel] [PATCH v5 14/38] block: Remove wr_highest_sector from BlockAcctStats

[Max Reitz]

BlockAcctStats contains statistics about the data transferred from and
to the device; wr_highest_sector does not fit in with the rest.

Furthermore, those statistics are supposed to be specific for a certain
device and not necessarily for a BDS (see the comment above
bdrv_get_stats()); on the other hand, wr_highest_sector may be a rather
important information to know for each BDS. When BlockAcctStats is
finally removed from the BDS, we will want to keep wr_highest_sector in
the BDS.

Finally, wr_highest_sector is renamed to wr_highest_offset and given the
appropriate meaning. Externally, it is represented as an offset so there
is no point in doing something different internally. Its definition is
changed to match that in qapi/block-core.json which is "the offset after
the greatest byte written to". Doing so should not cause any harm since
if external programs tried to calculate the volume usage by
(wr_highest_offset + 512) / volume_size, after this patch they will just
assume the volume to be full slightly earlier than before.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
---
 block/accounting.c         | 8 --------
 block/io.c                 | 4 +++-
 block/qapi.c               | 4 ++--
 include/block/accounting.h | 3 ---
 include/block/block_int.h  | 3 +++
 qmp-commands.hx            | 4 ++--
 6 files changed, 10 insertions(+), 16 deletions(-)

diff --git a/block/accounting.c b/block/accounting.c
index 01d594f..a423560 100644
--- a/block/accounting.c
+++ b/block/accounting.c
@@ -47,14 +47,6 @@ void block_acct_done(BlockAcctStats *stats, BlockAcctCookie *cookie)
 }
 
 
-void block_acct_highest_sector(BlockAcctStats *stats, int64_t sector_num,
-                               unsigned int nb_sectors)
-{
-    if (stats->wr_highest_sector < sector_num + nb_sectors - 1) {
-        stats->wr_highest_sector = sector_num + nb_sectors - 1;
-    }
-}
-
 void block_acct_merge_done(BlockAcctStats *stats, enum BlockAcctType type,
                       int num_requests)
 {
diff --git a/block/io.c b/block/io.c
index d4bc83b..21cc82a 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1141,7 +1141,9 @@ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs,
 
     bdrv_set_dirty(bs, sector_num, nb_sectors);
 
-    block_acct_highest_sector(&bs->stats, sector_num, nb_sectors);
+    if (bs->wr_highest_offset < offset + bytes) {
+        bs->wr_highest_offset = offset + bytes;
+    }
 
     if (ret >= 0) {
         bs->total_sectors = MAX(bs->total_sectors, sector_num + nb_sectors);
diff --git a/block/qapi.c b/block/qapi.c
index 2ce5097..d3cbc80 100644
--- a/block/qapi.c
+++ b/block/qapi.c
@@ -350,13 +350,13 @@ static BlockStats *bdrv_query_stats(const BlockDriverState *bs,
     s->stats->wr_operations = bs->stats.nr_ops[BLOCK_ACCT_WRITE];
     s->stats->rd_merged = bs->stats.merged[BLOCK_ACCT_READ];
     s->stats->wr_merged = bs->stats.merged[BLOCK_ACCT_WRITE];
-    s->stats->wr_highest_offset =
-        bs->stats.wr_highest_sector * BDRV_SECTOR_SIZE;
     s->stats->flush_operations = bs->stats.nr_ops[BLOCK_ACCT_FLUSH];
     s->stats->wr_total_time_ns = bs->stats.total_time_ns[BLOCK_ACCT_WRITE];
     s->stats->rd_total_time_ns = bs->stats.total_time_ns[BLOCK_ACCT_READ];
     s->stats->flush_total_time_ns = bs->stats.total_time_ns[BLOCK_ACCT_FLUSH];
 
+    s->stats->wr_highest_offset = bs->wr_highest_offset;
+
     if (bs->file) {
         s->has_parent = true;
         s->parent = bdrv_query_stats(bs->file, query_backing);
diff --git a/include/block/accounting.h b/include/block/accounting.h
index 4c406cf..66637cd 100644
--- a/include/block/accounting.h
+++ b/include/block/accounting.h
@@ -40,7 +40,6 @@ typedef struct BlockAcctStats {
     uint64_t nr_ops[BLOCK_MAX_IOTYPE];
     uint64_t total_time_ns[BLOCK_MAX_IOTYPE];
     uint64_t merged[BLOCK_MAX_IOTYPE];
-    uint64_t wr_highest_sector;
 } BlockAcctStats;
 
 typedef struct BlockAcctCookie {
@@ -52,8 +51,6 @@ typedef struct BlockAcctCookie {
 void block_acct_start(BlockAcctStats *stats, BlockAcctCookie *cookie,
                       int64_t bytes, enum BlockAcctType type);
 void block_acct_done(BlockAcctStats *stats, BlockAcctCookie *cookie);
-void block_acct_highest_sector(BlockAcctStats *stats, int64_t sector_num,
-                               unsigned int nb_sectors);
 void block_acct_merge_done(BlockAcctStats *stats, enum BlockAcctType type,
                            int num_requests);
 
diff --git a/include/block/block_int.h b/include/block/block_int.h
index b7e1e16..67e05ac 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -403,6 +403,9 @@ struct BlockDriverState {
     /* I/O stats (display with "info blockstats"). */
     BlockAcctStats stats;
 
+    /* Offset after the highest byte written to */
+    uint64_t wr_highest_offset;
+
     /* I/O Limits */
     BlockLimits bl;
 
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 9848fd8..8343289 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -2481,8 +2481,8 @@ Each json-object contain the following:
     - "wr_total_time_ns": total time spend on writes in nano-seconds (json-int)
     - "rd_total_time_ns": total time spend on reads in nano-seconds (json-int)
     - "flush_total_time_ns": total time spend on cache flushes in nano-seconds (json-int)
-    - "wr_highest_offset": Highest offset of a sector written since the
-                           BlockDriverState has been opened (json-int)
+    - "wr_highest_offset": The offset after the greatest byte written to the
+                           BlockDriverState since it has been opened (json-int)
     - "rd_merged": number of read requests that have been merged into
                    another request (json-int)
     - "wr_merged": number of write requests that have been merged into
-- 
2.5.2

[Qemu-devel] [PATCH v5 15/38] block: Move BlockAcctStats into BlockBackend

[Max Reitz]

As the comment above bdrv_get_stats() says, BlockAcctStats is something
which belongs to the device instead of each BlockDriverState. This patch
therefore moves it into the BlockBackend.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
---
 block.c                   | 11 -----------
 block/block-backend.c     |  5 ++++-
 block/io.c                |  6 +++++-
 block/qapi.c              | 24 ++++++++++++++----------
 include/block/block.h     |  2 --
 include/block/block_int.h |  3 ---
 6 files changed, 23 insertions(+), 28 deletions(-)

diff --git a/block.c b/block.c
index 55357c4..f81ef23 100644
--- a/block.c
+++ b/block.c
@@ -4256,14 +4256,3 @@ void bdrv_refresh_filename(BlockDriverState *bs)
         QDECREF(json);
     }
 }
-
-/* This accessor function purpose is to allow the device models to access the
- * BlockAcctStats structure embedded inside a BlockDriverState without being
- * aware of the BlockDriverState structure layout.
- * It will go away when the BlockAcctStats structure will be moved inside
- * the device models.
- */
-BlockAcctStats *bdrv_get_stats(BlockDriverState *bs)
-{
-    return &bs->stats;
-}
diff --git a/block/block-backend.c b/block/block-backend.c
index ff862ad..310ca50 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -34,6 +34,9 @@ struct BlockBackend {
 
     /* the block size for which the guest device expects atomicity */
     int guest_block_size;
+
+    /* I/O stats (display with "info blockstats"). */
+    BlockAcctStats stats;
 };
 
 typedef struct BlockBackendAIOCB {
@@ -875,7 +878,7 @@ void blk_io_unplug(BlockBackend *blk)
 
 BlockAcctStats *blk_get_stats(BlockBackend *blk)
 {
-    return bdrv_get_stats(blk->bs);
+    return &blk->stats;
 }
 
 void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk,
diff --git a/block/io.c b/block/io.c
index 21cc82a..08b50c0 100644
--- a/block/io.c
+++ b/block/io.c
@@ -23,6 +23,7 @@
  */
 
 #include "trace.h"
+#include "sysemu/block-backend.h"
 #include "block/blockjob.h"
 #include "block/block_int.h"
 #include "block/throttle-groups.h"
@@ -1895,7 +1896,10 @@ static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs,
         }
     }
 
-    block_acct_merge_done(&bs->stats, BLOCK_ACCT_WRITE, num_reqs - outidx - 1);
+    if (bs->blk) {
+        block_acct_merge_done(blk_get_stats(bs->blk), BLOCK_ACCT_WRITE,
+                              num_reqs - outidx - 1);
+    }
 
     return outidx + 1;
 }
diff --git a/block/qapi.c b/block/qapi.c
index d3cbc80..2d1ef87 100644
--- a/block/qapi.c
+++ b/block/qapi.c
@@ -344,16 +344,20 @@ static BlockStats *bdrv_query_stats(const BlockDriverState *bs,
     }
 
     s->stats = g_malloc0(sizeof(*s->stats));
-    s->stats->rd_bytes = bs->stats.nr_bytes[BLOCK_ACCT_READ];
-    s->stats->wr_bytes = bs->stats.nr_bytes[BLOCK_ACCT_WRITE];
-    s->stats->rd_operations = bs->stats.nr_ops[BLOCK_ACCT_READ];
-    s->stats->wr_operations = bs->stats.nr_ops[BLOCK_ACCT_WRITE];
-    s->stats->rd_merged = bs->stats.merged[BLOCK_ACCT_READ];
-    s->stats->wr_merged = bs->stats.merged[BLOCK_ACCT_WRITE];
-    s->stats->flush_operations = bs->stats.nr_ops[BLOCK_ACCT_FLUSH];
-    s->stats->wr_total_time_ns = bs->stats.total_time_ns[BLOCK_ACCT_WRITE];
-    s->stats->rd_total_time_ns = bs->stats.total_time_ns[BLOCK_ACCT_READ];
-    s->stats->flush_total_time_ns = bs->stats.total_time_ns[BLOCK_ACCT_FLUSH];
+    if (bs->blk) {
+        BlockAcctStats *stats = blk_get_stats(bs->blk);
+
+        s->stats->rd_bytes = stats->nr_bytes[BLOCK_ACCT_READ];
+        s->stats->wr_bytes = stats->nr_bytes[BLOCK_ACCT_WRITE];
+        s->stats->rd_operations = stats->nr_ops[BLOCK_ACCT_READ];
+        s->stats->wr_operations = stats->nr_ops[BLOCK_ACCT_WRITE];
+        s->stats->rd_merged = stats->merged[BLOCK_ACCT_READ];
+        s->stats->wr_merged = stats->merged[BLOCK_ACCT_WRITE];
+        s->stats->flush_operations = stats->nr_ops[BLOCK_ACCT_FLUSH];
+        s->stats->wr_total_time_ns = stats->total_time_ns[BLOCK_ACCT_WRITE];
+        s->stats->rd_total_time_ns = stats->total_time_ns[BLOCK_ACCT_READ];
+        s->stats->flush_total_time_ns = stats->total_time_ns[BLOCK_ACCT_FLUSH];
+    }
 
     s->stats->wr_highest_offset = bs->wr_highest_offset;
 
diff --git a/include/block/block.h b/include/block/block.h
index 3e818f4..960eb98 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -613,6 +613,4 @@ void bdrv_io_plug(BlockDriverState *bs);
 void bdrv_io_unplug(BlockDriverState *bs);
 void bdrv_flush_io_queue(BlockDriverState *bs);
 
-BlockAcctStats *bdrv_get_stats(BlockDriverState *bs);
-
 #endif
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 67e05ac..0376508 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -400,9 +400,6 @@ struct BlockDriverState {
     unsigned       pending_reqs[2];
     QLIST_ENTRY(BlockDriverState) round_robin;
 
-    /* I/O stats (display with "info blockstats"). */
-    BlockAcctStats stats;
-
     /* Offset after the highest byte written to */
     uint64_t wr_highest_offset;
 
-- 
2.5.2

[Qemu-devel] [PATCH v5 16/38] block: Move I/O status and error actions into BB

[Max Reitz]

These options are only relevant for the user of a whole BDS tree (like a
guest device or a block job) and should thus be moved into the
BlockBackend.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 block.c                        | 125 -----------------------------------------
 block/backup.c                 |  17 ++++--
 block/block-backend.c          | 116 ++++++++++++++++++++++++++++++++++++--
 block/commit.c                 |   3 +-
 block/mirror.c                 |  17 ++++--
 block/qapi.c                   |   4 +-
 block/stream.c                 |   3 +-
 blockdev.c                     |   6 +-
 blockjob.c                     |   5 +-
 include/block/block.h          |  11 ----
 include/block/block_int.h      |   6 --
 include/sysemu/block-backend.h |   7 +++
 qmp.c                          |   6 +-
 13 files changed, 158 insertions(+), 168 deletions(-)

diff --git a/block.c b/block.c
index f81ef23..67a39fb 100644
--- a/block.c
+++ b/block.c
@@ -257,7 +257,6 @@ BlockDriverState *bdrv_new(void)
     for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
         QLIST_INIT(&bs->op_blockers[i]);
     }
-    bdrv_iostatus_disable(bs);
     notifier_list_init(&bs->close_notifiers);
     notifier_with_return_list_init(&bs->before_write_notifiers);
     qemu_co_queue_init(&bs->throttled_reqs[0]);
@@ -2038,14 +2037,6 @@ static void bdrv_move_feature_fields(BlockDriverState *bs_dest,
            &bs_src->throttle_timers,
            sizeof(ThrottleTimers));
 
-    /* r/w error */
-    bs_dest->on_read_error      = bs_src->on_read_error;
-    bs_dest->on_write_error     = bs_src->on_write_error;
-
-    /* i/o status */
-    bs_dest->iostatus_enabled   = bs_src->iostatus_enabled;
-    bs_dest->iostatus           = bs_src->iostatus;
-
     /* dirty bitmap */
     bs_dest->dirty_bitmaps      = bs_src->dirty_bitmaps;
 
@@ -2605,82 +2596,6 @@ void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
     *nb_sectors_ptr = nb_sectors < 0 ? 0 : nb_sectors;
 }
 
-void bdrv_set_on_error(BlockDriverState *bs, BlockdevOnError on_read_error,
-                       BlockdevOnError on_write_error)
-{
-    bs->on_read_error = on_read_error;
-    bs->on_write_error = on_write_error;
-}
-
-BlockdevOnError bdrv_get_on_error(BlockDriverState *bs, bool is_read)
-{
-    return is_read ? bs->on_read_error : bs->on_write_error;
-}
-
-BlockErrorAction bdrv_get_error_action(BlockDriverState *bs, bool is_read, int error)
-{
-    BlockdevOnError on_err = is_read ? bs->on_read_error : bs->on_write_error;
-
-    switch (on_err) {
-    case BLOCKDEV_ON_ERROR_ENOSPC:
-        return (error == ENOSPC) ?
-               BLOCK_ERROR_ACTION_STOP : BLOCK_ERROR_ACTION_REPORT;
-    case BLOCKDEV_ON_ERROR_STOP:
-        return BLOCK_ERROR_ACTION_STOP;
-    case BLOCKDEV_ON_ERROR_REPORT:
-        return BLOCK_ERROR_ACTION_REPORT;
-    case BLOCKDEV_ON_ERROR_IGNORE:
-        return BLOCK_ERROR_ACTION_IGNORE;
-    default:
-        abort();
-    }
-}
-
-static void send_qmp_error_event(BlockDriverState *bs,
-                                 BlockErrorAction action,
-                                 bool is_read, int error)
-{
-    IoOperationType optype;
-
-    optype = is_read ? IO_OPERATION_TYPE_READ : IO_OPERATION_TYPE_WRITE;
-    qapi_event_send_block_io_error(bdrv_get_device_name(bs), optype, action,
-                                   bdrv_iostatus_is_enabled(bs),
-                                   error == ENOSPC, strerror(error),
-                                   &error_abort);
-}
-
-/* This is done by device models because, while the block layer knows
- * about the error, it does not know whether an operation comes from
- * the device or the block layer (from a job, for example).
- */
-void bdrv_error_action(BlockDriverState *bs, BlockErrorAction action,
-                       bool is_read, int error)
-{
-    assert(error >= 0);
-
-    if (action == BLOCK_ERROR_ACTION_STOP) {
-        /* First set the iostatus, so that "info block" returns an iostatus
-         * that matches the events raised so far (an additional error iostatus
-         * is fine, but not a lost one).
-         */
-        bdrv_iostatus_set_err(bs, error);
-
-        /* Then raise the request to stop the VM and the event.
-         * qemu_system_vmstop_request_prepare has two effects.  First,
-         * it ensures that the STOP event always comes after the
-         * BLOCK_IO_ERROR event.  Second, it ensures that even if management
-         * can observe the STOP event and do a "cont" before the STOP
-         * event is issued, the VM will not stop.  In this case, vm_start()
-         * also ensures that the STOP/RESUME pair of events is emitted.
-         */
-        qemu_system_vmstop_request_prepare();
-        send_qmp_error_event(bs, action, is_read, error);
-        qemu_system_vmstop_request(RUN_STATE_IO_ERROR);
-    } else {
-        send_qmp_error_event(bs, action, is_read, error);
-    }
-}
-
 int bdrv_is_read_only(BlockDriverState *bs)
 {
     return bs->read_only;
@@ -3706,46 +3621,6 @@ bool bdrv_op_blocker_is_empty(BlockDriverState *bs)
     return true;
 }
 
-void bdrv_iostatus_enable(BlockDriverState *bs)
-{
-    bs->iostatus_enabled = true;
-    bs->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
-}
-
-/* The I/O status is only enabled if the drive explicitly
- * enables it _and_ the VM is configured to stop on errors */
-bool bdrv_iostatus_is_enabled(const BlockDriverState *bs)
-{
-    return (bs->iostatus_enabled &&
-           (bs->on_write_error == BLOCKDEV_ON_ERROR_ENOSPC ||
-            bs->on_write_error == BLOCKDEV_ON_ERROR_STOP   ||
-            bs->on_read_error == BLOCKDEV_ON_ERROR_STOP));
-}
-
-void bdrv_iostatus_disable(BlockDriverState *bs)
-{
-    bs->iostatus_enabled = false;
-}
-
-void bdrv_iostatus_reset(BlockDriverState *bs)
-{
-    if (bdrv_iostatus_is_enabled(bs)) {
-        bs->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
-        if (bs->job) {
-            block_job_iostatus_reset(bs->job);
-        }
-    }
-}
-
-void bdrv_iostatus_set_err(BlockDriverState *bs, int error)
-{
-    assert(bdrv_iostatus_is_enabled(bs));
-    if (bs->iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
-        bs->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE :
-                                         BLOCK_DEVICE_IO_STATUS_FAILED;
-    }
-}
-
 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,
diff --git a/block/backup.c b/block/backup.c
index 965654d..c61e4c3 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -21,6 +21,7 @@
 #include "block/blockjob.h"
 #include "qapi/qmp/qerror.h"
 #include "qemu/ratelimit.h"
+#include "sysemu/block-backend.h"
 
 #define BACKUP_CLUSTER_BITS 16
 #define BACKUP_CLUSTER_SIZE (1 << BACKUP_CLUSTER_BITS)
@@ -208,7 +209,9 @@ static void backup_iostatus_reset(BlockJob *job)
 {
     BackupBlockJob *s = container_of(job, BackupBlockJob, common);
 
-    bdrv_iostatus_reset(s->target);
+    if (s->target->blk) {
+        blk_iostatus_reset(s->target->blk);
+    }
 }
 
 static const BlockJobDriver backup_job_driver = {
@@ -352,8 +355,10 @@ static void coroutine_fn backup_run(void *opaque)
     job->bitmap = hbitmap_alloc(end, 0);
 
     bdrv_set_enable_write_cache(target, true);
-    bdrv_set_on_error(target, on_target_error, on_target_error);
-    bdrv_iostatus_enable(target);
+    if (target->blk) {
+        blk_set_on_error(target->blk, on_target_error, on_target_error);
+        blk_iostatus_enable(target->blk);
+    }
 
     bdrv_add_before_write_notifier(bs, &before_write);
 
@@ -443,7 +448,9 @@ static void coroutine_fn backup_run(void *opaque)
     }
     hbitmap_free(job->bitmap);
 
-    bdrv_iostatus_disable(target);
+    if (target->blk) {
+        blk_iostatus_disable(target->blk);
+    }
     bdrv_op_unblock_all(target, job->common.blocker);
 
     data = g_malloc(sizeof(*data));
@@ -472,7 +479,7 @@ void backup_start(BlockDriverState *bs, BlockDriverState *target,
 
     if ((on_source_error == BLOCKDEV_ON_ERROR_STOP ||
          on_source_error == BLOCKDEV_ON_ERROR_ENOSPC) &&
-        !bdrv_iostatus_is_enabled(bs)) {
+        (!bs->blk || !blk_iostatus_is_enabled(bs->blk))) {
         error_setg(errp, QERR_INVALID_PARAMETER, "on-source-error");
         return;
     }
diff --git a/block/block-backend.c b/block/block-backend.c
index 310ca50..1f2cd9b 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -12,7 +12,9 @@
 
 #include "sysemu/block-backend.h"
 #include "block/block_int.h"
+#include "block/blockjob.h"
 #include "sysemu/blockdev.h"
+#include "sysemu/sysemu.h"
 #include "qapi-event.h"
 
 /* Number of coroutines to reserve per attached device model */
@@ -37,6 +39,10 @@ struct BlockBackend {
 
     /* I/O stats (display with "info blockstats"). */
     BlockAcctStats stats;
+
+    BlockdevOnError on_read_error, on_write_error;
+    bool iostatus_enabled;
+    BlockDeviceIoStatus iostatus;
 };
 
 typedef struct BlockBackendAIOCB {
@@ -313,7 +319,7 @@ int blk_attach_dev(BlockBackend *blk, void *dev)
     }
     blk_ref(blk);
     blk->dev = dev;
-    bdrv_iostatus_reset(blk->bs);
+    blk_iostatus_reset(blk);
     return 0;
 }
 
@@ -445,7 +451,47 @@ void blk_dev_resize_cb(BlockBackend *blk)
 
 void blk_iostatus_enable(BlockBackend *blk)
 {
-    bdrv_iostatus_enable(blk->bs);
+    blk->iostatus_enabled = true;
+    blk->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
+}
+
+/* The I/O status is only enabled if the drive explicitly
+ * enables it _and_ the VM is configured to stop on errors */
+bool blk_iostatus_is_enabled(const BlockBackend *blk)
+{
+    return (blk->iostatus_enabled &&
+           (blk->on_write_error == BLOCKDEV_ON_ERROR_ENOSPC ||
+            blk->on_write_error == BLOCKDEV_ON_ERROR_STOP   ||
+            blk->on_read_error == BLOCKDEV_ON_ERROR_STOP));
+}
+
+BlockDeviceIoStatus blk_iostatus(const BlockBackend *blk)
+{
+    return blk->iostatus;
+}
+
+void blk_iostatus_disable(BlockBackend *blk)
+{
+    blk->iostatus_enabled = false;
+}
+
+void blk_iostatus_reset(BlockBackend *blk)
+{
+    if (blk_iostatus_is_enabled(blk)) {
+        blk->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
+        if (blk->bs && blk->bs->job) {
+            block_job_iostatus_reset(blk->bs->job);
+        }
+    }
+}
+
+void blk_iostatus_set_err(BlockBackend *blk, int error)
+{
+    assert(blk_iostatus_is_enabled(blk));
+    if (blk->iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
+        blk->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE :
+                                          BLOCK_DEVICE_IO_STATUS_FAILED;
+    }
 }
 
 static int blk_check_byte_request(BlockBackend *blk, int64_t offset,
@@ -721,21 +767,81 @@ void blk_drain_all(void)
     bdrv_drain_all();
 }
 
+void blk_set_on_error(BlockBackend *blk, BlockdevOnError on_read_error,
+                      BlockdevOnError on_write_error)
+{
+    blk->on_read_error = on_read_error;
+    blk->on_write_error = on_write_error;
+}
+
 BlockdevOnError blk_get_on_error(BlockBackend *blk, bool is_read)
 {
-    return bdrv_get_on_error(blk->bs, is_read);
+    return is_read ? blk->on_read_error : blk->on_write_error;
 }
 
 BlockErrorAction blk_get_error_action(BlockBackend *blk, bool is_read,
                                       int error)
 {
-    return bdrv_get_error_action(blk->bs, is_read, error);
+    BlockdevOnError on_err = blk_get_on_error(blk, is_read);
+
+    switch (on_err) {
+    case BLOCKDEV_ON_ERROR_ENOSPC:
+        return (error == ENOSPC) ?
+               BLOCK_ERROR_ACTION_STOP : BLOCK_ERROR_ACTION_REPORT;
+    case BLOCKDEV_ON_ERROR_STOP:
+        return BLOCK_ERROR_ACTION_STOP;
+    case BLOCKDEV_ON_ERROR_REPORT:
+        return BLOCK_ERROR_ACTION_REPORT;
+    case BLOCKDEV_ON_ERROR_IGNORE:
+        return BLOCK_ERROR_ACTION_IGNORE;
+    default:
+        abort();
+    }
 }
 
+static void send_qmp_error_event(BlockBackend *blk,
+                                 BlockErrorAction action,
+                                 bool is_read, int error)
+{
+    IoOperationType optype;
+
+    optype = is_read ? IO_OPERATION_TYPE_READ : IO_OPERATION_TYPE_WRITE;
+    qapi_event_send_block_io_error(blk_name(blk), optype, action,
+                                   blk_iostatus_is_enabled(blk),
+                                   error == ENOSPC, strerror(error),
+                                   &error_abort);
+}
+
+/* This is done by device models because, while the block layer knows
+ * about the error, it does not know whether an operation comes from
+ * the device or the block layer (from a job, for example).
+ */
 void blk_error_action(BlockBackend *blk, BlockErrorAction action,
                       bool is_read, int error)
 {
-    bdrv_error_action(blk->bs, action, is_read, error);
+    assert(error >= 0);
+
+    if (action == BLOCK_ERROR_ACTION_STOP) {
+        /* First set the iostatus, so that "info block" returns an iostatus
+         * that matches the events raised so far (an additional error iostatus
+         * is fine, but not a lost one).
+         */
+        blk_iostatus_set_err(blk, error);
+
+        /* Then raise the request to stop the VM and the event.
+         * qemu_system_vmstop_request_prepare has two effects.  First,
+         * it ensures that the STOP event always comes after the
+         * BLOCK_IO_ERROR event.  Second, it ensures that even if management
+         * can observe the STOP event and do a "cont" before the STOP
+         * event is issued, the VM will not stop.  In this case, vm_start()
+         * also ensures that the STOP/RESUME pair of events is emitted.
+         */
+        qemu_system_vmstop_request_prepare();
+        send_qmp_error_event(blk, action, is_read, error);
+        qemu_system_vmstop_request(RUN_STATE_IO_ERROR);
+    } else {
+        send_qmp_error_event(blk, action, is_read, error);
+    }
 }
 
 int blk_is_read_only(BlockBackend *blk)
diff --git a/block/commit.c b/block/commit.c
index d12e26f..fdebe87 100644
--- a/block/commit.c
+++ b/block/commit.c
@@ -17,6 +17,7 @@
 #include "block/blockjob.h"
 #include "qapi/qmp/qerror.h"
 #include "qemu/ratelimit.h"
+#include "sysemu/block-backend.h"
 
 enum {
     /*
@@ -213,7 +214,7 @@ void commit_start(BlockDriverState *bs, BlockDriverState *base,
 
     if ((on_error == BLOCKDEV_ON_ERROR_STOP ||
          on_error == BLOCKDEV_ON_ERROR_ENOSPC) &&
-        !bdrv_iostatus_is_enabled(bs)) {
+        (!bs->blk || !blk_iostatus_is_enabled(bs->blk))) {
         error_setg(errp, "Invalid parameter combination");
         return;
     }
diff --git a/block/mirror.c b/block/mirror.c
index a258926..56c18b1 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -14,6 +14,7 @@
 #include "trace.h"
 #include "block/blockjob.h"
 #include "block/block_int.h"
+#include "sysemu/block-backend.h"
 #include "qapi/qmp/qerror.h"
 #include "qemu/ratelimit.h"
 #include "qemu/bitmap.h"
@@ -598,7 +599,9 @@ immediate_exit:
     g_free(s->cow_bitmap);
     g_free(s->in_flight_bitmap);
     bdrv_release_dirty_bitmap(bs, s->dirty_bitmap);
-    bdrv_iostatus_disable(s->target);
+    if (s->target->blk) {
+        blk_iostatus_disable(s->target->blk);
+    }
 
     data = g_malloc(sizeof(*data));
     data->ret = ret;
@@ -620,7 +623,9 @@ static void mirror_iostatus_reset(BlockJob *job)
 {
     MirrorBlockJob *s = container_of(job, MirrorBlockJob, common);
 
-    bdrv_iostatus_reset(s->target);
+    if (s->target->blk) {
+        blk_iostatus_reset(s->target->blk);
+    }
 }
 
 static void mirror_complete(BlockJob *job, Error **errp)
@@ -704,7 +709,7 @@ static void mirror_start_job(BlockDriverState *bs, BlockDriverState *target,
 
     if ((on_source_error == BLOCKDEV_ON_ERROR_STOP ||
          on_source_error == BLOCKDEV_ON_ERROR_ENOSPC) &&
-        !bdrv_iostatus_is_enabled(bs)) {
+        (!bs->blk || !blk_iostatus_is_enabled(bs->blk))) {
         error_setg(errp, QERR_INVALID_PARAMETER, "on-source-error");
         return;
     }
@@ -740,8 +745,10 @@ static void mirror_start_job(BlockDriverState *bs, BlockDriverState *target,
         return;
     }
     bdrv_set_enable_write_cache(s->target, true);
-    bdrv_set_on_error(s->target, on_target_error, on_target_error);
-    bdrv_iostatus_enable(s->target);
+    if (s->target->blk) {
+        blk_set_on_error(s->target->blk, on_target_error, on_target_error);
+        blk_iostatus_enable(s->target->blk);
+    }
     s->common.co = qemu_coroutine_create(mirror_run);
     trace_mirror_start(bs, s, s->common.co, opaque);
     qemu_coroutine_enter(s->common.co, s);
diff --git a/block/qapi.c b/block/qapi.c
index 2d1ef87..f295692 100644
--- a/block/qapi.c
+++ b/block/qapi.c
@@ -301,9 +301,9 @@ static void bdrv_query_info(BlockBackend *blk, BlockInfo **p_info,
         info->tray_open = blk_dev_is_tray_open(blk);
     }
 
-    if (bdrv_iostatus_is_enabled(bs)) {
+    if (blk_iostatus_is_enabled(blk)) {
         info->has_io_status = true;
-        info->io_status = bs->iostatus;
+        info->io_status = blk_iostatus(blk);
     }
 
     if (!QLIST_EMPTY(&bs->dirty_bitmaps)) {
diff --git a/block/stream.c b/block/stream.c
index ab0bd05..a0b090d 100644
--- a/block/stream.c
+++ b/block/stream.c
@@ -16,6 +16,7 @@
 #include "block/blockjob.h"
 #include "qapi/qmp/qerror.h"
 #include "qemu/ratelimit.h"
+#include "sysemu/block-backend.h"
 
 enum {
     /*
@@ -250,7 +251,7 @@ void stream_start(BlockDriverState *bs, BlockDriverState *base,
 
     if ((on_error == BLOCKDEV_ON_ERROR_STOP ||
          on_error == BLOCKDEV_ON_ERROR_ENOSPC) &&
-        !bdrv_iostatus_is_enabled(bs)) {
+        (!bs->blk || !blk_iostatus_is_enabled(bs->blk))) {
         error_setg(errp, QERR_INVALID_PARAMETER, "on-error");
         return;
     }
diff --git a/blockdev.c b/blockdev.c
index 013583b..01d422e 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -551,7 +551,7 @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
 
     bs->detect_zeroes = detect_zeroes;
 
-    bdrv_set_on_error(bs, on_read_error, on_write_error);
+    blk_set_on_error(blk, on_read_error, on_write_error);
 
     /* disk I/O throttling */
     if (throttle_enabled(&cfg)) {
@@ -2170,8 +2170,8 @@ void hmp_drive_del(Monitor *mon, const QDict *qdict)
     if (blk_get_attached_dev(blk)) {
         blk_hide_on_behalf_of_hmp_drive_del(blk);
         /* Further I/O must not pause the guest */
-        bdrv_set_on_error(bs, BLOCKDEV_ON_ERROR_REPORT,
-                          BLOCKDEV_ON_ERROR_REPORT);
+        blk_set_on_error(blk, BLOCKDEV_ON_ERROR_REPORT,
+                         BLOCKDEV_ON_ERROR_REPORT);
     } else {
         blk_unref(blk);
     }
diff --git a/blockjob.c b/blockjob.c
index 62bb906..ca4be94 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -29,6 +29,7 @@
 #include "block/block.h"
 #include "block/blockjob.h"
 #include "block/block_int.h"
+#include "sysemu/block-backend.h"
 #include "qapi/qmp/qerror.h"
 #include "qapi/qmp/qjson.h"
 #include "block/coroutine.h"
@@ -353,8 +354,8 @@ BlockErrorAction block_job_error_action(BlockJob *job, BlockDriverState *bs,
         job->user_paused = true;
         block_job_pause(job);
         block_job_iostatus_set_err(job, error);
-        if (bs != job->bs) {
-            bdrv_iostatus_set_err(bs, error);
+        if (bs->blk && bs != job->bs) {
+            blk_iostatus_set_err(bs->blk, error);
         }
     }
     return action;
diff --git a/include/block/block.h b/include/block/block.h
index 960eb98..11c0316 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -173,11 +173,6 @@ typedef enum BlockOpType {
     BLOCK_OP_TYPE_MAX,
 } BlockOpType;
 
-void bdrv_iostatus_enable(BlockDriverState *bs);
-void bdrv_iostatus_reset(BlockDriverState *bs);
-void bdrv_iostatus_disable(BlockDriverState *bs);
-bool bdrv_iostatus_is_enabled(const BlockDriverState *bs);
-void bdrv_iostatus_set_err(BlockDriverState *bs, int error);
 void bdrv_info_print(Monitor *mon, const QObject *data);
 void bdrv_info(Monitor *mon, QObject **ret_data);
 void bdrv_stats_print(Monitor *mon, const QObject *data);
@@ -387,12 +382,6 @@ int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
 int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base,
                             int64_t sector_num, int nb_sectors, int *pnum);
 
-void bdrv_set_on_error(BlockDriverState *bs, BlockdevOnError on_read_error,
-                       BlockdevOnError on_write_error);
-BlockdevOnError bdrv_get_on_error(BlockDriverState *bs, bool is_read);
-BlockErrorAction bdrv_get_error_action(BlockDriverState *bs, bool is_read, int error);
-void bdrv_error_action(BlockDriverState *bs, BlockErrorAction action,
-                       bool is_read, int error);
 int bdrv_is_read_only(BlockDriverState *bs);
 int bdrv_is_sg(BlockDriverState *bs);
 int bdrv_enable_write_cache(BlockDriverState *bs);
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 0376508..bd35570 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -415,12 +415,6 @@ struct BlockDriverState {
     /* do we need to tell the quest if we have a volatile write cache? */
     int enable_write_cache;
 
-    /* NOTE: the following infos are only hints for real hardware
-       drivers. They are not used by the block driver */
-    BlockdevOnError on_read_error, on_write_error;
-    bool iostatus_enabled;
-    BlockDeviceIoStatus iostatus;
-
     /* 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 */
diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
index 1e19d1b..eafcef0 100644
--- a/include/sysemu/block-backend.h
+++ b/include/sysemu/block-backend.h
@@ -76,6 +76,11 @@ BlockDriverState *blk_bs(BlockBackend *blk);
 void blk_hide_on_behalf_of_hmp_drive_del(BlockBackend *blk);
 
 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, void *dev);
 void blk_attach_dev_nofail(BlockBackend *blk, void *dev);
 void blk_detach_dev(BlockBackend *blk, void *dev);
@@ -120,6 +125,8 @@ int blk_flush(BlockBackend *blk);
 int blk_flush_all(void);
 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);
diff --git a/qmp.c b/qmp.c
index 9623c80..8c3dca8 100644
--- a/qmp.c
+++ b/qmp.c
@@ -24,6 +24,7 @@
 #include "sysemu/arch_init.h"
 #include "hw/qdev.h"
 #include "sysemu/blockdev.h"
+#include "sysemu/block-backend.h"
 #include "qom/qom-qobject.h"
 #include "qapi/qmp/qerror.h"
 #include "qapi/qmp/qobject.h"
@@ -170,6 +171,7 @@ SpiceInfo *qmp_query_spice(Error **errp)
 void qmp_cont(Error **errp)
 {
     Error *local_err = NULL;
+    BlockBackend *blk;
     BlockDriverState *bs;
 
     if (runstate_needs_reset()) {
@@ -179,8 +181,8 @@ void qmp_cont(Error **errp)
         return;
     }
 
-    for (bs = bdrv_next(NULL); bs; bs = bdrv_next(bs)) {
-        bdrv_iostatus_reset(bs);
+    for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
+        blk_iostatus_reset(blk);
     }
     for (bs = bdrv_next(NULL); bs; bs = bdrv_next(bs)) {
         bdrv_add_key(bs, NULL, &local_err);
-- 
2.5.2

[Qemu-devel] [PATCH v5 17/38] block: Add BlockBackendRootState

[Max Reitz]

This structure will store some of the state of the root BDS if the BDS
tree is removed, so that state can be restored once a new BDS tree is
inserted.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 block/block-backend.c          | 37 +++++++++++++++++++++++++++++++++++++
 include/block/block_int.h      | 10 ++++++++++
 include/qemu/typedefs.h        |  1 +
 include/sysemu/block-backend.h |  2 ++
 4 files changed, 50 insertions(+)

diff --git a/block/block-backend.c b/block/block-backend.c
index 1f2cd9b..9590be5 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -13,6 +13,7 @@
 #include "sysemu/block-backend.h"
 #include "block/block_int.h"
 #include "block/blockjob.h"
+#include "block/throttle-groups.h"
 #include "sysemu/blockdev.h"
 #include "sysemu/sysemu.h"
 #include "qapi-event.h"
@@ -37,6 +38,10 @@ struct BlockBackend {
     /* the block size for which the guest device expects atomicity */
     int guest_block_size;
 
+    /* If the BDS tree is removed, some of its options are stored here (which
+     * can be used to restore those options in the new BDS on insert) */
+    BlockBackendRootState root_state;
+
     /* I/O stats (display with "info blockstats"). */
     BlockAcctStats stats;
 
@@ -161,6 +166,7 @@ static void blk_delete(BlockBackend *blk)
         bdrv_unref(blk->bs);
         blk->bs = NULL;
     }
+    g_free(blk->root_state.throttle_group_name);
     /* Avoid double-remove after blk_hide_on_behalf_of_hmp_drive_del() */
     if (blk->name[0]) {
         QTAILQ_REMOVE(&blk_backends, blk, link);
@@ -1050,3 +1056,34 @@ int blk_probe_geometry(BlockBackend *blk, HDGeometry *geo)
 {
     return bdrv_probe_geometry(blk->bs, geo);
 }
+
+/*
+ * Updates the BlockBackendRootState object with data from the currently
+ * attached BlockDriverState.
+ */
+void blk_update_root_state(BlockBackend *blk)
+{
+    assert(blk->bs);
+
+    blk->root_state.open_flags    = blk->bs->open_flags;
+    blk->root_state.read_only     = blk->bs->read_only;
+    blk->root_state.detect_zeroes = blk->bs->detect_zeroes;
+
+    blk->root_state.io_limits_enabled = blk->bs->io_limits_enabled;
+
+    g_free(blk->root_state.throttle_group_name);
+    if (blk->bs->throttle_state) {
+        throttle_get_config(blk->bs->throttle_state,
+                            &blk->root_state.throttle_config);
+        blk->root_state.throttle_group_name =
+            g_strdup(throttle_group_get_name(blk->bs));
+    } else {
+        blk->root_state.throttle_config = (ThrottleConfig){};
+        blk->root_state.throttle_group_name = NULL;
+    }
+}
+
+BlockBackendRootState *blk_get_root_state(BlockBackend *blk)
+{
+    return &blk->root_state;
+}
diff --git a/include/block/block_int.h b/include/block/block_int.h
index bd35570..ca1eefa 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -449,6 +449,16 @@ struct BlockDriverState {
     NotifierWithReturn write_threshold_notifier;
 };
 
+struct BlockBackendRootState {
+    int open_flags;
+    bool read_only;
+    BlockdevDetectZeroesOptions detect_zeroes;
+
+    bool io_limits_enabled;
+    ThrottleConfig throttle_config;
+    char *throttle_group_name;
+};
+
 
 /* Essential block drivers which must always be statically linked into qemu, and
  * which therefore can be accessed without using bdrv_find_format() */
diff --git a/include/qemu/typedefs.h b/include/qemu/typedefs.h
index 97ac727..5105cc7 100644
--- a/include/qemu/typedefs.h
+++ b/include/qemu/typedefs.h
@@ -11,6 +11,7 @@ typedef struct AddressSpace AddressSpace;
 typedef struct AioContext AioContext;
 typedef struct AudioState AudioState;
 typedef struct BlockBackend BlockBackend;
+typedef struct BlockBackendRootState BlockBackendRootState;
 typedef struct BlockDriverState BlockDriverState;
 typedef struct BusClass BusClass;
 typedef struct BusState BusState;
diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
index eafcef0..52e35a1 100644
--- a/include/sysemu/block-backend.h
+++ b/include/sysemu/block-backend.h
@@ -163,6 +163,8 @@ void blk_add_close_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);
 
 void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk,
                   BlockCompletionFunc *cb, void *opaque);
-- 
2.5.2

[Qemu-devel] [PATCH v5 18/38] block: Make some BB functions fall back to BBRS

[Max Reitz]

If there is no BDS tree attached to a BlockBackend, functions that can
do so should fall back to the BlockBackendRootState structure (which are
blk_is_read_only() and blk_get_flags(), because the read-only status and
the "open flags" are part of the BBRS).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 block/block-backend.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/block/block-backend.c b/block/block-backend.c
index 9590be5..417374f 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -852,7 +852,11 @@ void blk_error_action(BlockBackend *blk, BlockErrorAction action,
 
 int blk_is_read_only(BlockBackend *blk)
 {
-    return bdrv_is_read_only(blk->bs);
+    if (blk->bs) {
+        return bdrv_is_read_only(blk->bs);
+    } else {
+        return blk->root_state.read_only;
+    }
 }
 
 int blk_is_sg(BlockBackend *blk)
@@ -897,7 +901,11 @@ void blk_eject(BlockBackend *blk, bool eject_flag)
 
 int blk_get_flags(BlockBackend *blk)
 {
-    return bdrv_get_flags(blk->bs);
+    if (blk->bs) {
+        return bdrv_get_flags(blk->bs);
+    } else {
+        return blk->root_state.open_flags;
+    }
 }
 
 int blk_get_max_transfer_length(BlockBackend *blk)
-- 
2.5.2

[Qemu-devel] [PATCH v5 19/38] block: Fail requests to empty BlockBackend

[Max Reitz]

If there is no BlockDriverState in a BlockBackend or if the tray of the
guest device is open, fail all requests (where that is possible) with
-ENOMEDIUM.

The reason the status of the guest device is taken into account is
because once the guest device's tray is opened, any request on the same
BlockBackend as the guest uses should fail. If the BDS tree is supposed
to be usable even after ejecting it from the guest, a different
BlockBackend must be used.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 block/block-backend.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 54 insertions(+), 1 deletion(-)

diff --git a/block/block-backend.c b/block/block-backend.c
index 417374f..0da4be9 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -509,7 +509,7 @@ static int blk_check_byte_request(BlockBackend *blk, int64_t offset,
         return -EIO;
     }
 
-    if (!blk_is_inserted(blk)) {
+    if (!blk_is_available(blk)) {
         return -ENOMEDIUM;
     }
 
@@ -648,6 +648,10 @@ int blk_pwrite(BlockBackend *blk, int64_t offset, const void *buf, int count)
 
 int64_t blk_getlength(BlockBackend *blk)
 {
+    if (!blk_is_available(blk)) {
+        return -ENOMEDIUM;
+    }
+
     return bdrv_getlength(blk->bs);
 }
 
@@ -658,6 +662,10 @@ void blk_get_geometry(BlockBackend *blk, uint64_t *nb_sectors_ptr)
 
 int64_t blk_nb_sectors(BlockBackend *blk)
 {
+    if (!blk_is_available(blk)) {
+        return -ENOMEDIUM;
+    }
+
     return bdrv_nb_sectors(blk->bs);
 }
 
@@ -688,6 +696,10 @@ BlockAIOCB *blk_aio_writev(BlockBackend *blk, int64_t sector_num,
 BlockAIOCB *blk_aio_flush(BlockBackend *blk,
                           BlockCompletionFunc *cb, void *opaque)
 {
+    if (!blk_is_available(blk)) {
+        return abort_aio_request(blk, cb, opaque, -ENOMEDIUM);
+    }
+
     return bdrv_aio_flush(blk->bs, cb, opaque);
 }
 
@@ -729,12 +741,20 @@ int blk_aio_multiwrite(BlockBackend *blk, BlockRequest *reqs, int num_reqs)
 
 int blk_ioctl(BlockBackend *blk, unsigned long int req, void *buf)
 {
+    if (!blk_is_available(blk)) {
+        return -ENOMEDIUM;
+    }
+
     return bdrv_ioctl(blk->bs, req, buf);
 }
 
 BlockAIOCB *blk_aio_ioctl(BlockBackend *blk, unsigned long int req, void *buf,
                           BlockCompletionFunc *cb, void *opaque)
 {
+    if (!blk_is_available(blk)) {
+        return abort_aio_request(blk, cb, opaque, -ENOMEDIUM);
+    }
+
     return bdrv_aio_ioctl(blk->bs, req, buf, cb, opaque);
 }
 
@@ -750,11 +770,19 @@ int blk_co_discard(BlockBackend *blk, int64_t sector_num, int nb_sectors)
 
 int blk_co_flush(BlockBackend *blk)
 {
+    if (!blk_is_available(blk)) {
+        return -ENOMEDIUM;
+    }
+
     return bdrv_co_flush(blk->bs);
 }
 
 int blk_flush(BlockBackend *blk)
 {
+    if (!blk_is_available(blk)) {
+        return -ENOMEDIUM;
+    }
+
     return bdrv_flush(blk->bs);
 }
 
@@ -876,6 +904,11 @@ void blk_set_enable_write_cache(BlockBackend *blk, bool wce)
 
 void blk_invalidate_cache(BlockBackend *blk, Error **errp)
 {
+    if (!blk->bs) {
+        error_setg(errp, "Device '%s' has no medium", blk->name);
+        return;
+    }
+
     bdrv_invalidate_cache(blk->bs, errp);
 }
 
@@ -1031,6 +1064,10 @@ int blk_write_compressed(BlockBackend *blk, int64_t sector_num,
 
 int blk_truncate(BlockBackend *blk, int64_t offset)
 {
+    if (!blk_is_available(blk)) {
+        return -ENOMEDIUM;
+    }
+
     return bdrv_truncate(blk->bs, offset);
 }
 
@@ -1047,21 +1084,37 @@ int blk_discard(BlockBackend *blk, int64_t sector_num, int nb_sectors)
 int blk_save_vmstate(BlockBackend *blk, const uint8_t *buf,
                      int64_t pos, int size)
 {
+    if (!blk_is_available(blk)) {
+        return -ENOMEDIUM;
+    }
+
     return bdrv_save_vmstate(blk->bs, buf, pos, size);
 }
 
 int blk_load_vmstate(BlockBackend *blk, uint8_t *buf, int64_t pos, int size)
 {
+    if (!blk_is_available(blk)) {
+        return -ENOMEDIUM;
+    }
+
     return bdrv_load_vmstate(blk->bs, buf, pos, size);
 }
 
 int blk_probe_blocksizes(BlockBackend *blk, BlockSizes *bsz)
 {
+    if (!blk_is_available(blk)) {
+        return -ENOMEDIUM;
+    }
+
     return bdrv_probe_blocksizes(blk->bs, bsz);
 }
 
 int blk_probe_geometry(BlockBackend *blk, HDGeometry *geo)
 {
+    if (!blk_is_available(blk)) {
+        return -ENOMEDIUM;
+    }
+
     return bdrv_probe_geometry(blk->bs, geo);
 }
 
-- 
2.5.2

[Qemu-devel] [PATCH v5 20/38] block: Prepare remaining BB functions for NULL BDS

[Max Reitz]

There are several BlockBackend functions which, in theory, cannot fail.
This patch makes them cope with the BlockDriverState pointer being NULL
by making them fall back to some default action like ignoring the value
in setters and returning the default in getters.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 block/block-backend.c | 76 ++++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 60 insertions(+), 16 deletions(-)

diff --git a/block/block-backend.c b/block/block-backend.c
index 0da4be9..33145f8 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -657,7 +657,11 @@ int64_t blk_getlength(BlockBackend *blk)
 
 void blk_get_geometry(BlockBackend *blk, uint64_t *nb_sectors_ptr)
 {
-    bdrv_get_geometry(blk->bs, nb_sectors_ptr);
+    if (!blk->bs) {
+        *nb_sectors_ptr = 0;
+    } else {
+        bdrv_get_geometry(blk->bs, nb_sectors_ptr);
+    }
 }
 
 int64_t blk_nb_sectors(BlockBackend *blk)
@@ -889,17 +893,27 @@ int blk_is_read_only(BlockBackend *blk)
 
 int blk_is_sg(BlockBackend *blk)
 {
+    if (!blk->bs) {
+        return 0;
+    }
+
     return bdrv_is_sg(blk->bs);
 }
 
 int blk_enable_write_cache(BlockBackend *blk)
 {
+    if (!blk->bs) {
+        return 0;
+    }
+
     return bdrv_enable_write_cache(blk->bs);
 }
 
 void blk_set_enable_write_cache(BlockBackend *blk, bool wce)
 {
-    bdrv_set_enable_write_cache(blk->bs, wce);
+    if (blk->bs) {
+        bdrv_set_enable_write_cache(blk->bs, wce);
+    }
 }
 
 void blk_invalidate_cache(BlockBackend *blk, Error **errp)
@@ -924,12 +938,16 @@ bool blk_is_available(BlockBackend *blk)
 
 void blk_lock_medium(BlockBackend *blk, bool locked)
 {
-    bdrv_lock_medium(blk->bs, locked);
+    if (blk->bs) {
+        bdrv_lock_medium(blk->bs, locked);
+    }
 }
 
 void blk_eject(BlockBackend *blk, bool eject_flag)
 {
-    bdrv_eject(blk->bs, eject_flag);
+    if (blk->bs) {
+        bdrv_eject(blk->bs, eject_flag);
+    }
 }
 
 int blk_get_flags(BlockBackend *blk)
@@ -943,7 +961,11 @@ int blk_get_flags(BlockBackend *blk)
 
 int blk_get_max_transfer_length(BlockBackend *blk)
 {
-    return blk->bs->bl.max_transfer_length;
+    if (blk->bs) {
+        return blk->bs->bl.max_transfer_length;
+    } else {
+        return 0;
+    }
 }
 
 void blk_set_guest_block_size(BlockBackend *blk, int align)
@@ -958,22 +980,32 @@ void *blk_blockalign(BlockBackend *blk, size_t size)
 
 bool blk_op_is_blocked(BlockBackend *blk, BlockOpType op, Error **errp)
 {
+    if (!blk->bs) {
+        return false;
+    }
+
     return bdrv_op_is_blocked(blk->bs, op, errp);
 }
 
 void blk_op_unblock(BlockBackend *blk, BlockOpType op, Error *reason)
 {
-    bdrv_op_unblock(blk->bs, op, reason);
+    if (blk->bs) {
+        bdrv_op_unblock(blk->bs, op, reason);
+    }
 }
 
 void blk_op_block_all(BlockBackend *blk, Error *reason)
 {
-    bdrv_op_block_all(blk->bs, reason);
+    if (blk->bs) {
+        bdrv_op_block_all(blk->bs, reason);
+    }
 }
 
 void blk_op_unblock_all(BlockBackend *blk, Error *reason)
 {
-    bdrv_op_unblock_all(blk->bs, reason);
+    if (blk->bs) {
+        bdrv_op_unblock_all(blk->bs, reason);
+    }
 }
 
 AioContext *blk_get_aio_context(BlockBackend *blk)
@@ -993,15 +1025,19 @@ static AioContext *blk_aiocb_get_aio_context(BlockAIOCB *acb)
 
 void blk_set_aio_context(BlockBackend *blk, AioContext *new_context)
 {
-    bdrv_set_aio_context(blk->bs, new_context);
+    if (blk->bs) {
+        bdrv_set_aio_context(blk->bs, new_context);
+    }
 }
 
 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)
 {
-    bdrv_add_aio_context_notifier(blk->bs, attached_aio_context,
-                                  detach_aio_context, opaque);
+    if (blk->bs) {
+        bdrv_add_aio_context_notifier(blk->bs, attached_aio_context,
+                                      detach_aio_context, opaque);
+    }
 }
 
 void blk_remove_aio_context_notifier(BlockBackend *blk,
@@ -1010,23 +1046,31 @@ void blk_remove_aio_context_notifier(BlockBackend *blk,
                                      void (*detach_aio_context)(void *),
                                      void *opaque)
 {
-    bdrv_remove_aio_context_notifier(blk->bs, attached_aio_context,
-                                     detach_aio_context, opaque);
+    if (blk->bs) {
+        bdrv_remove_aio_context_notifier(blk->bs, attached_aio_context,
+                                         detach_aio_context, opaque);
+    }
 }
 
 void blk_add_close_notifier(BlockBackend *blk, Notifier *notify)
 {
-    bdrv_add_close_notifier(blk->bs, notify);
+    if (blk->bs) {
+        bdrv_add_close_notifier(blk->bs, notify);
+    }
 }
 
 void blk_io_plug(BlockBackend *blk)
 {
-    bdrv_io_plug(blk->bs);
+    if (blk->bs) {
+        bdrv_io_plug(blk->bs);
+    }
 }
 
 void blk_io_unplug(BlockBackend *blk)
 {
-    bdrv_io_unplug(blk->bs);
+    if (blk->bs) {
+        bdrv_io_unplug(blk->bs);
+    }
 }
 
 BlockAcctStats *blk_get_stats(BlockBackend *blk)
-- 
2.5.2

[Qemu-devel] [PATCH v5 21/38] block: Add blk_insert_bs()

[Max Reitz]

This function associates the given BlockDriverState with the given
BlockBackend.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
---
 block/block-backend.c          | 16 ++++++++++++++++
 include/sysemu/block-backend.h |  1 +
 2 files changed, 17 insertions(+)

diff --git a/block/block-backend.c b/block/block-backend.c
index 33145f8..652385e 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -314,6 +314,22 @@ void blk_hide_on_behalf_of_hmp_drive_del(BlockBackend *blk)
 }
 
 /*
+ * Associates a new BlockDriverState with @blk.
+ */
+void blk_insert_bs(BlockBackend *blk, BlockDriverState *bs)
+{
+    if (bs->blk == blk) {
+        return;
+    }
+
+    assert(!blk->bs);
+    assert(!bs->blk);
+    bdrv_ref(bs);
+    blk->bs = bs;
+    bs->blk = blk;
+}
+
+/*
  * Attach device model @dev to @blk.
  * Return 0 on success, -EBUSY when a device model is attached already.
  */
diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
index 52e35a1..9306a52 100644
--- a/include/sysemu/block-backend.h
+++ b/include/sysemu/block-backend.h
@@ -72,6 +72,7 @@ BlockBackend *blk_by_name(const char *name);
 BlockBackend *blk_next(BlockBackend *blk);
 
 BlockDriverState *blk_bs(BlockBackend *blk);
+void blk_insert_bs(BlockBackend *blk, BlockDriverState *bs);
 
 void blk_hide_on_behalf_of_hmp_drive_del(BlockBackend *blk);
 
-- 
2.5.2

[Qemu-devel] [PATCH v5 22/38] block: Prepare for NULL BDS

[Max Reitz]

blk_bs() will not necessarily return a non-NULL value any more (unless
blk_is_available() is true or it can be assumed to otherwise, e.g.
because it is called immediately after a successful blk_new_with_bs() or
blk_new_open()).

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block.c             |   5 ++
 block/qapi.c        |   4 +-
 blockdev.c          | 201 ++++++++++++++++++++++++++++++++++------------------
 hw/block/xen_disk.c |   4 +-
 migration/block.c   |   5 ++
 monitor.c           |   4 ++
 6 files changed, 153 insertions(+), 70 deletions(-)

diff --git a/block.c b/block.c
index 67a39fb..7776871 100644
--- a/block.c
+++ b/block.c
@@ -2787,6 +2787,11 @@ BlockDriverState *bdrv_lookup_bs(const char *device,
         blk = blk_by_name(device);
 
         if (blk) {
+            if (!blk_bs(blk)) {
+                error_setg(errp, "Device '%s' has no medium", device);
+                return NULL;
+            }
+
             return blk_bs(blk);
         }
     }
diff --git a/block/qapi.c b/block/qapi.c
index f295692..e936ba7 100644
--- a/block/qapi.c
+++ b/block/qapi.c
@@ -306,12 +306,12 @@ static void bdrv_query_info(BlockBackend *blk, BlockInfo **p_info,
         info->io_status = blk_iostatus(blk);
     }
 
-    if (!QLIST_EMPTY(&bs->dirty_bitmaps)) {
+    if (bs && !QLIST_EMPTY(&bs->dirty_bitmaps)) {
         info->has_dirty_bitmaps = true;
         info->dirty_bitmaps = bdrv_query_dirty_bitmaps(bs);
     }
 
-    if (bs->drv) {
+    if (bs && bs->drv) {
         info->has_inserted = true;
         info->inserted = bdrv_block_device_info(bs, errp);
         if (info->inserted == NULL) {
diff --git a/blockdev.c b/blockdev.c
index 01d422e..6168b09 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -124,14 +124,16 @@ void blockdev_mark_auto_del(BlockBackend *blk)
         return;
     }
 
-    aio_context = bdrv_get_aio_context(bs);
-    aio_context_acquire(aio_context);
+    if (bs) {
+        aio_context = bdrv_get_aio_context(bs);
+        aio_context_acquire(aio_context);
 
-    if (bs->job) {
-        block_job_cancel(bs->job);
-    }
+        if (bs->job) {
+            block_job_cancel(bs->job);
+        }
 
-    aio_context_release(aio_context);
+        aio_context_release(aio_context);
+    }
 
     dinfo->auto_del = 1;
 }
@@ -229,8 +231,8 @@ bool drive_check_orphaned(void)
             dinfo->type != IF_NONE) {
             fprintf(stderr, "Warning: Orphaned drive without device: "
                     "id=%s,file=%s,if=%s,bus=%d,unit=%d\n",
-                    blk_name(blk), blk_bs(blk)->filename, if_name[dinfo->type],
-                    dinfo->bus, dinfo->unit);
+                    blk_name(blk), blk_bs(blk) ? blk_bs(blk)->filename : "",
+                    if_name[dinfo->type], dinfo->bus, dinfo->unit);
             rs = true;
         }
     }
@@ -1040,6 +1042,10 @@ void hmp_commit(Monitor *mon, const QDict *qdict)
             monitor_printf(mon, "Device '%s' not found\n", device);
             return;
         }
+        if (!blk_is_available(blk)) {
+            monitor_printf(mon, "Device '%s' has no medium\n", device);
+            return;
+        }
         ret = bdrv_commit(blk_bs(blk));
     }
     if (ret < 0) {
@@ -1119,7 +1125,9 @@ SnapshotInfo *qmp_blockdev_snapshot_delete_internal_sync(const char *device,
                   "Device '%s' not found", device);
         return NULL;
     }
-    bs = blk_bs(blk);
+
+    aio_context = blk_get_aio_context(blk);
+    aio_context_acquire(aio_context);
 
     if (!has_id) {
         id = NULL;
@@ -1131,11 +1139,14 @@ SnapshotInfo *qmp_blockdev_snapshot_delete_internal_sync(const char *device,
 
     if (!id && !name) {
         error_setg(errp, "Name or id must be provided");
-        return NULL;
+        goto out_aio_context;
     }
 
-    aio_context = bdrv_get_aio_context(bs);
-    aio_context_acquire(aio_context);
+    if (!blk_is_available(blk)) {
+        error_setg(errp, "Device '%s' has no medium", device);
+        goto out_aio_context;
+    }
+    bs = blk_bs(blk);
 
     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE, errp)) {
         goto out_aio_context;
@@ -1309,16 +1320,16 @@ static void internal_snapshot_prepare(BlkTransactionState *common,
                   "Device '%s' not found", device);
         return;
     }
-    bs = blk_bs(blk);
 
     /* AioContext is released in .clean() */
-    state->aio_context = bdrv_get_aio_context(bs);
+    state->aio_context = blk_get_aio_context(blk);
     aio_context_acquire(state->aio_context);
 
-    if (!bdrv_is_inserted(bs)) {
+    if (!blk_is_available(blk)) {
         error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
         return;
     }
+    bs = blk_bs(blk);
 
     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_INTERNAL_SNAPSHOT, errp)) {
         return;
@@ -1570,7 +1581,6 @@ typedef struct DriveBackupState {
 static void drive_backup_prepare(BlkTransactionState *common, Error **errp)
 {
     DriveBackupState *state = DO_UPCAST(DriveBackupState, common, common);
-    BlockDriverState *bs;
     BlockBackend *blk;
     DriveBackup *backup;
     Error *local_err = NULL;
@@ -1584,12 +1594,16 @@ static void drive_backup_prepare(BlkTransactionState *common, Error **errp)
                   "Device '%s' not found", backup->device);
         return;
     }
-    bs = blk_bs(blk);
 
     /* AioContext is released in .clean() */
-    state->aio_context = bdrv_get_aio_context(bs);
+    state->aio_context = blk_get_aio_context(blk);
     aio_context_acquire(state->aio_context);
 
+    if (!blk_is_available(blk)) {
+        error_setg(errp, "Device '%s' has no medium", backup->device);
+        return;
+    }
+
     qmp_drive_backup(backup->device, backup->target,
                      backup->has_format, backup->format,
                      backup->sync,
@@ -1604,7 +1618,7 @@ static void drive_backup_prepare(BlkTransactionState *common, Error **errp)
         return;
     }
 
-    state->bs = bs;
+    state->bs = blk_bs(blk);
     state->job = state->bs->job;
 }
 
@@ -1639,8 +1653,7 @@ static void blockdev_backup_prepare(BlkTransactionState *common, Error **errp)
 {
     BlockdevBackupState *state = DO_UPCAST(BlockdevBackupState, common, common);
     BlockdevBackup *backup;
-    BlockDriverState *bs, *target;
-    BlockBackend *blk;
+    BlockBackend *blk, *target;
     Error *local_err = NULL;
 
     assert(common->action->kind == TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP);
@@ -1651,18 +1664,16 @@ static void blockdev_backup_prepare(BlkTransactionState *common, Error **errp)
         error_setg(errp, "Device '%s' not found", backup->device);
         return;
     }
-    bs = blk_bs(blk);
 
-    blk = blk_by_name(backup->target);
-    if (!blk) {
+    target = blk_by_name(backup->target);
+    if (!target) {
         error_setg(errp, "Device '%s' not found", backup->target);
         return;
     }
-    target = blk_bs(blk);
 
     /* AioContext is released in .clean() */
-    state->aio_context = bdrv_get_aio_context(bs);
-    if (state->aio_context != bdrv_get_aio_context(target)) {
+    state->aio_context = blk_get_aio_context(blk);
+    if (state->aio_context != blk_get_aio_context(target)) {
         state->aio_context = NULL;
         error_setg(errp, "Backup between two IO threads is not implemented");
         return;
@@ -1680,7 +1691,7 @@ static void blockdev_backup_prepare(BlkTransactionState *common, Error **errp)
         return;
     }
 
-    state->bs = bs;
+    state->bs = blk_bs(blk);
     state->job = state->bs->job;
 }
 
@@ -1818,10 +1829,10 @@ static void eject_device(BlockBackend *blk, int force, Error **errp)
     BlockDriverState *bs = blk_bs(blk);
     AioContext *aio_context;
 
-    aio_context = bdrv_get_aio_context(bs);
+    aio_context = blk_get_aio_context(blk);
     aio_context_acquire(aio_context);
 
-    if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_EJECT, errp)) {
+    if (bs && bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_EJECT, errp)) {
         goto out;
     }
     if (!blk_dev_has_removable_media(blk)) {
@@ -1839,7 +1850,9 @@ static void eject_device(BlockBackend *blk, int force, Error **errp)
         }
     }
 
-    bdrv_close(bs);
+    if (bs) {
+        bdrv_close(bs);
+    }
 
 out:
     aio_context_release(aio_context);
@@ -1884,10 +1897,12 @@ void qmp_block_passwd(bool has_device, const char *device,
 }
 
 /* Assumes AioContext is held */
-static void qmp_bdrv_open_encrypted(BlockDriverState *bs, const char *filename,
+static void qmp_bdrv_open_encrypted(BlockDriverState **pbs,
+                                    const char *filename,
                                     int bdrv_flags, const char *format,
                                     const char *password, Error **errp)
 {
+    BlockDriverState *bs;
     Error *local_err = NULL;
     QDict *options = NULL;
     int ret;
@@ -1897,11 +1912,12 @@ static void qmp_bdrv_open_encrypted(BlockDriverState *bs, const char *filename,
         qdict_put(options, "driver", qstring_from_str(format));
     }
 
-    ret = bdrv_open(&bs, filename, NULL, options, bdrv_flags, &local_err);
+    ret = bdrv_open(pbs, filename, NULL, options, bdrv_flags, &local_err);
     if (ret < 0) {
         error_propagate(errp, local_err);
         return;
     }
+    bs = *pbs;
 
     bdrv_add_key(bs, password, errp);
 }
@@ -1913,6 +1929,7 @@ void qmp_change_blockdev(const char *device, const char *filename,
     BlockDriverState *bs;
     AioContext *aio_context;
     int bdrv_flags;
+    bool new_bs;
     Error *err = NULL;
 
     blk = blk_by_name(device);
@@ -1922,8 +1939,9 @@ void qmp_change_blockdev(const char *device, const char *filename,
         return;
     }
     bs = blk_bs(blk);
+    new_bs = !bs;
 
-    aio_context = bdrv_get_aio_context(bs);
+    aio_context = blk_get_aio_context(blk);
     aio_context_acquire(aio_context);
 
     eject_device(blk, 0, &err);
@@ -1932,10 +1950,18 @@ void qmp_change_blockdev(const char *device, const char *filename,
         goto out;
     }
 
-    bdrv_flags = bdrv_is_read_only(bs) ? 0 : BDRV_O_RDWR;
-    bdrv_flags |= bdrv_is_snapshot(bs) ? BDRV_O_SNAPSHOT : 0;
+    bdrv_flags = blk_is_read_only(blk) ? 0 : BDRV_O_RDWR;
+    bdrv_flags |= blk_get_root_state(blk)->open_flags & ~BDRV_O_RDWR;
 
-    qmp_bdrv_open_encrypted(bs, filename, bdrv_flags, format, NULL, errp);
+    qmp_bdrv_open_encrypted(&bs, filename, bdrv_flags, format, NULL, &err);
+    if (err) {
+        error_propagate(errp, err);
+    } else if (new_bs) {
+        blk_insert_bs(blk, bs);
+        /* Has been sent automatically by bdrv_open() if blk_bs(blk) was not
+         * NULL */
+        blk_dev_change_media_cb(blk, true);
+    }
 
 out:
     aio_context_release(aio_context);
@@ -1975,7 +2001,15 @@ void qmp_block_set_io_throttle(const char *device, int64_t bps, int64_t bps_rd,
                   "Device '%s' not found", device);
         return;
     }
+
+    aio_context = blk_get_aio_context(blk);
+    aio_context_acquire(aio_context);
+
     bs = blk_bs(blk);
+    if (!bs) {
+        error_setg(errp, "Device '%s' has no medium", device);
+        goto out;
+    }
 
     memset(&cfg, 0, sizeof(cfg));
     cfg.buckets[THROTTLE_BPS_TOTAL].avg = bps;
@@ -2010,12 +2044,9 @@ void qmp_block_set_io_throttle(const char *device, int64_t bps, int64_t bps_rd,
     }
 
     if (!check_throttle_config(&cfg, errp)) {
-        return;
+        goto out;
     }
 
-    aio_context = bdrv_get_aio_context(bs);
-    aio_context_acquire(aio_context);
-
     if (throttle_enabled(&cfg)) {
         /* Enable I/O limits if they're not enabled yet, otherwise
          * just update the throttling group. */
@@ -2031,6 +2062,7 @@ void qmp_block_set_io_throttle(const char *device, int64_t bps, int64_t bps_rd,
         bdrv_io_limits_disable(bs);
     }
 
+out:
     aio_context_release(aio_context);
 }
 
@@ -2143,7 +2175,6 @@ void hmp_drive_del(Monitor *mon, const QDict *qdict)
         error_report("Device '%s' not found", id);
         return;
     }
-    bs = blk_bs(blk);
 
     if (!blk_legacy_dinfo(blk)) {
         error_report("Deleting device added with blockdev-add"
@@ -2151,16 +2182,19 @@ void hmp_drive_del(Monitor *mon, const QDict *qdict)
         return;
     }
 
-    aio_context = bdrv_get_aio_context(bs);
+    aio_context = blk_get_aio_context(blk);
     aio_context_acquire(aio_context);
 
-    if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_DRIVE_DEL, &local_err)) {
+    bs = blk_bs(blk);
+    if (bs && bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_DRIVE_DEL, &local_err)) {
         error_report_err(local_err);
         aio_context_release(aio_context);
         return;
     }
 
-    bdrv_close(bs);
+    if (bs) {
+        bdrv_close(bs);
+    }
 
     /* if we have a device attached to this BlockDriverState
      * then we need to make the drive anonymous until the device
@@ -2293,11 +2327,16 @@ void qmp_block_stream(const char *device,
                   "Device '%s' not found", device);
         return;
     }
-    bs = blk_bs(blk);
 
-    aio_context = bdrv_get_aio_context(bs);
+    aio_context = blk_get_aio_context(blk);
     aio_context_acquire(aio_context);
 
+    if (!blk_is_available(blk)) {
+        error_setg(errp, "Device '%s' has no medium", device);
+        goto out;
+    }
+    bs = blk_bs(blk);
+
     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_STREAM, errp)) {
         goto out;
     }
@@ -2368,11 +2407,16 @@ void qmp_block_commit(const char *device,
                   "Device '%s' not found", device);
         return;
     }
-    bs = blk_bs(blk);
 
-    aio_context = bdrv_get_aio_context(bs);
+    aio_context = blk_get_aio_context(blk);
     aio_context_acquire(aio_context);
 
+    if (!blk_is_available(blk)) {
+        error_setg(errp, "Device '%s' has no medium", device);
+        goto out;
+    }
+    bs = blk_bs(blk);
+
     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_COMMIT_SOURCE, errp)) {
         goto out;
     }
@@ -2478,17 +2522,17 @@ void qmp_drive_backup(const char *device, const char *target,
                   "Device '%s' not found", device);
         return;
     }
-    bs = blk_bs(blk);
 
-    aio_context = bdrv_get_aio_context(bs);
+    aio_context = blk_get_aio_context(blk);
     aio_context_acquire(aio_context);
 
     /* Although backup_run has this check too, we need to use bs->drv below, so
      * do an early check redundantly. */
-    if (!bdrv_is_inserted(bs)) {
+    if (!blk_is_available(blk)) {
         error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
         goto out;
     }
+    bs = blk_bs(blk);
 
     if (!has_format) {
         format = mode == NEW_IMAGE_MODE_EXISTING ? NULL : bs->drv->format_name;
@@ -2585,7 +2629,7 @@ void qmp_blockdev_backup(const char *device, const char *target,
                          BlockdevOnError on_target_error,
                          Error **errp)
 {
-    BlockBackend *blk;
+    BlockBackend *blk, *target_blk;
     BlockDriverState *bs;
     BlockDriverState *target_bs;
     Error *local_err = NULL;
@@ -2606,17 +2650,27 @@ void qmp_blockdev_backup(const char *device, const char *target,
         error_setg(errp, "Device '%s' not found", device);
         return;
     }
-    bs = blk_bs(blk);
 
-    aio_context = bdrv_get_aio_context(bs);
+    aio_context = blk_get_aio_context(blk);
     aio_context_acquire(aio_context);
 
-    blk = blk_by_name(target);
-    if (!blk) {
+    if (!blk_is_available(blk)) {
+        error_setg(errp, "Device '%s' has no medium", device);
+        goto out;
+    }
+    bs = blk_bs(blk);
+
+    target_blk = blk_by_name(target);
+    if (!target_blk) {
         error_setg(errp, "Device '%s' not found", target);
         goto out;
     }
-    target_bs = blk_bs(blk);
+
+    if (!blk_is_available(target_blk)) {
+        error_setg(errp, "Device '%s' has no medium", target);
+        goto out;
+    }
+    target_bs = blk_bs(target_blk);
 
     bdrv_ref(target_bs);
     bdrv_set_aio_context(target_bs, aio_context);
@@ -2693,15 +2747,15 @@ void qmp_drive_mirror(const char *device, const char *target,
                   "Device '%s' not found", device);
         return;
     }
-    bs = blk_bs(blk);
 
-    aio_context = bdrv_get_aio_context(bs);
+    aio_context = blk_get_aio_context(blk);
     aio_context_acquire(aio_context);
 
-    if (!bdrv_is_inserted(bs)) {
+    if (!blk_is_available(blk)) {
         error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
         goto out;
     }
+    bs = blk_bs(blk);
 
     if (!has_format) {
         format = mode == NEW_IMAGE_MODE_EXISTING ? NULL : bs->drv->format_name;
@@ -2831,17 +2885,22 @@ static BlockJob *find_block_job(const char *device, AioContext **aio_context,
     BlockBackend *blk;
     BlockDriverState *bs;
 
+    *aio_context = NULL;
+
     blk = blk_by_name(device);
     if (!blk) {
         goto notfound;
     }
-    bs = blk_bs(blk);
 
-    *aio_context = bdrv_get_aio_context(bs);
+    *aio_context = blk_get_aio_context(blk);
     aio_context_acquire(*aio_context);
 
+    if (!blk_is_available(blk)) {
+        goto notfound;
+    }
+    bs = blk_bs(blk);
+
     if (!bs->job) {
-        aio_context_release(*aio_context);
         goto notfound;
     }
 
@@ -2850,7 +2909,10 @@ static BlockJob *find_block_job(const char *device, AioContext **aio_context,
 notfound:
     error_set(errp, ERROR_CLASS_DEVICE_NOT_ACTIVE,
               "No active block job on device '%s'", device);
-    *aio_context = NULL;
+    if (*aio_context) {
+        aio_context_release(*aio_context);
+        *aio_context = NULL;
+    }
     return NULL;
 }
 
@@ -2957,11 +3019,16 @@ void qmp_change_backing_file(const char *device,
                   "Device '%s' not found", device);
         return;
     }
-    bs = blk_bs(blk);
 
-    aio_context = bdrv_get_aio_context(bs);
+    aio_context = blk_get_aio_context(blk);
     aio_context_acquire(aio_context);
 
+    if (!blk_is_available(blk)) {
+        error_setg(errp, "Device '%s' has no medium", device);
+        goto out;
+    }
+    bs = blk_bs(blk);
+
     image_bs = bdrv_lookup_bs(NULL, image_node_name, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
diff --git a/hw/block/xen_disk.c b/hw/block/xen_disk.c
index 36d7398..1bbc111 100644
--- a/hw/block/xen_disk.c
+++ b/hw/block/xen_disk.c
@@ -931,9 +931,11 @@ static int blk_connect(struct XenDevice *xendev)
     blk_attach_dev_nofail(blkdev->blk, blkdev);
     blkdev->file_size = blk_getlength(blkdev->blk);
     if (blkdev->file_size < 0) {
+        BlockDriverState *bs = blk_bs(blkdev->blk);
+        const char *drv_name = bs ? bdrv_get_format_name(bs) : NULL;
         xen_be_printf(&blkdev->xendev, 1, "blk_getlength: %d (%s) | drv %s\n",
                       (int)blkdev->file_size, strerror(-blkdev->file_size),
-                      bdrv_get_format_name(blk_bs(blkdev->blk)) ?: "-");
+                      drv_name ?: "-");
         blkdev->file_size = 0;
     }
 
diff --git a/migration/block.c b/migration/block.c
index ed865ed..f7bb1e0 100644
--- a/migration/block.c
+++ b/migration/block.c
@@ -808,6 +808,11 @@ static int block_load(QEMUFile *f, void *opaque, int version_id)
                 return -EINVAL;
             }
             bs = blk_bs(blk);
+            if (!bs) {
+                fprintf(stderr, "Block device %s has no medium\n",
+                        device_name);
+                return -EINVAL;
+            }
 
             if (bs != bs_prev) {
                 bs_prev = bs;
diff --git a/monitor.c b/monitor.c
index 1f43263..94b7267 100644
--- a/monitor.c
+++ b/monitor.c
@@ -4130,6 +4130,10 @@ int monitor_read_block_device_key(Monitor *mon, const char *device,
         monitor_printf(mon, "Device not found %s\n", device);
         return -1;
     }
+    if (!blk_bs(blk)) {
+        monitor_printf(mon, "Device '%s' has no medium\n", device);
+        return -1;
+    }
 
     bdrv_add_key(blk_bs(blk), NULL, &err);
     if (err) {
-- 
2.5.2

[Qemu-devel] [PATCH v5 23/38] blockdev: Do not create BDS for empty drive

[Max Reitz]

Do not use "rudimentary" BDSs for empty drives any longer (for
freshly created drives).

After a follow-up patch, empty drives will generally use a NULL BDS, not
only the freshly created drives.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 blockdev.c | 72 ++++++++++++++++++++++++++++++++++++++------------------------
 1 file changed, 44 insertions(+), 28 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index 6168b09..e76a7de 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -514,16 +514,44 @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
         goto early_err;
     }
 
+    if (snapshot) {
+        /* always use cache=unsafe with snapshot */
+        bdrv_flags &= ~BDRV_O_CACHE_MASK;
+        bdrv_flags |= (BDRV_O_SNAPSHOT|BDRV_O_CACHE_WB|BDRV_O_NO_FLUSH);
+    }
+
+    if (copy_on_read) {
+        bdrv_flags |= BDRV_O_COPY_ON_READ;
+    }
+
+    if (runstate_check(RUN_STATE_INMIGRATE)) {
+        bdrv_flags |= BDRV_O_INCOMING;
+    }
+
+    bdrv_flags |= ro ? 0 : BDRV_O_RDWR;
+
     /* init */
     if ((!file || !*file) && !has_driver_specific_opts) {
-        blk = blk_new_with_bs(qemu_opts_id(opts), errp);
+        BlockBackendRootState *blk_rs;
+
+        blk = blk_new(qemu_opts_id(opts), errp);
         if (!blk) {
             goto early_err;
         }
 
-        bs = blk_bs(blk);
-        bs->open_flags = snapshot ? BDRV_O_SNAPSHOT : 0;
-        bs->read_only = ro;
+        blk_rs = blk_get_root_state(blk);
+        blk_rs->open_flags    = bdrv_flags;
+        blk_rs->read_only     = ro;
+        blk_rs->detect_zeroes = detect_zeroes;
+
+        if (throttle_enabled(&cfg)) {
+            if (!throttling_group) {
+                throttling_group = blk_name(blk);
+            }
+            blk_rs->io_limits_enabled = true;
+            blk_rs->throttle_config = cfg;
+            blk_rs->throttle_group_name = g_strdup(throttling_group);
+        }
 
         QDECREF(bs_opts);
     } else {
@@ -531,42 +559,30 @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
             file = NULL;
         }
 
-        if (snapshot) {
-            /* always use cache=unsafe with snapshot */
-            bdrv_flags &= ~BDRV_O_CACHE_MASK;
-            bdrv_flags |= (BDRV_O_SNAPSHOT|BDRV_O_CACHE_WB|BDRV_O_NO_FLUSH);
-        }
-
-        if (copy_on_read) {
-            bdrv_flags |= BDRV_O_COPY_ON_READ;
-        }
-
-        bdrv_flags |= ro ? 0 : BDRV_O_RDWR;
-
         blk = blk_new_open(qemu_opts_id(opts), file, NULL, bs_opts, bdrv_flags,
                            errp);
         if (!blk) {
             goto err_no_bs_opts;
         }
         bs = blk_bs(blk);
-    }
 
-    bs->detect_zeroes = detect_zeroes;
+        bs->detect_zeroes = detect_zeroes;
 
-    blk_set_on_error(blk, on_read_error, on_write_error);
+        /* disk I/O throttling */
+        if (throttle_enabled(&cfg)) {
+            if (!throttling_group) {
+                throttling_group = blk_name(blk);
+            }
+            bdrv_io_limits_enable(bs, throttling_group);
+            bdrv_set_io_limits(bs, &cfg);
+        }
 
-    /* disk I/O throttling */
-    if (throttle_enabled(&cfg)) {
-        if (!throttling_group) {
-            throttling_group = blk_name(blk);
+        if (bdrv_key_required(bs)) {
+            autostart = 0;
         }
-        bdrv_io_limits_enable(bs, throttling_group);
-        bdrv_set_io_limits(bs, &cfg);
     }
 
-    if (bdrv_key_required(bs)) {
-        autostart = 0;
-    }
+    blk_set_on_error(blk, on_read_error, on_write_error);
 
 err_no_bs_opts:
     qemu_opts_del(opts);
-- 
2.5.2

[Qemu-devel] [PATCH v5 24/38] blockdev: Pull out blockdev option extraction

[Max Reitz]

Extract some of the blockdev option extraction code from blockdev_init()
into its own function. This simplifies blockdev_init() and will allow
reusing the code in a different function added in a follow-up patch.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 blockdev.c | 209 +++++++++++++++++++++++++++++++++----------------------------
 1 file changed, 113 insertions(+), 96 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index e76a7de..688ee5f 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -350,25 +350,128 @@ static bool check_throttle_config(ThrottleConfig *cfg, Error **errp)
 
 typedef enum { MEDIA_DISK, MEDIA_CDROM } DriveMediaType;
 
+static void extract_common_blockdev_options(QemuOpts *opts, int *bdrv_flags,
+    ThrottleConfig *throttle_cfg, BlockdevDetectZeroesOptions *detect_zeroes,
+    const char **throttling_group, Error **errp)
+{
+    const char *discard;
+    Error *local_error = NULL;
+#ifdef CONFIG_LINUX_AIO
+    const char *aio;
+#endif
+
+    if (!qemu_opt_get_bool(opts, "read-only", false)) {
+        *bdrv_flags |= BDRV_O_RDWR;
+    }
+    if (qemu_opt_get_bool(opts, "copy-on-read", false)) {
+        *bdrv_flags |= BDRV_O_COPY_ON_READ;
+    }
+
+    if ((discard = qemu_opt_get(opts, "discard")) != NULL) {
+        if (bdrv_parse_discard_flags(discard, bdrv_flags) != 0) {
+            error_setg(errp, "Invalid discard option");
+            return;
+        }
+    }
+
+    if (qemu_opt_get_bool(opts, BDRV_OPT_CACHE_WB, true)) {
+        *bdrv_flags |= BDRV_O_CACHE_WB;
+    }
+    if (qemu_opt_get_bool(opts, BDRV_OPT_CACHE_DIRECT, false)) {
+        *bdrv_flags |= BDRV_O_NOCACHE;
+    }
+    if (qemu_opt_get_bool(opts, BDRV_OPT_CACHE_NO_FLUSH, false)) {
+        *bdrv_flags |= BDRV_O_NO_FLUSH;
+    }
+
+#ifdef CONFIG_LINUX_AIO
+    if ((aio = qemu_opt_get(opts, "aio")) != NULL) {
+        if (!strcmp(aio, "native")) {
+            *bdrv_flags |= BDRV_O_NATIVE_AIO;
+        } else if (!strcmp(aio, "threads")) {
+            /* this is the default */
+        } else {
+           error_setg(errp, "invalid aio option");
+           return;
+        }
+    }
+#endif
+
+    /* disk I/O throttling */
+    memset(throttle_cfg, 0, sizeof(*throttle_cfg));
+    throttle_cfg->buckets[THROTTLE_BPS_TOTAL].avg =
+        qemu_opt_get_number(opts, "throttling.bps-total", 0);
+    throttle_cfg->buckets[THROTTLE_BPS_READ].avg  =
+        qemu_opt_get_number(opts, "throttling.bps-read", 0);
+    throttle_cfg->buckets[THROTTLE_BPS_WRITE].avg =
+        qemu_opt_get_number(opts, "throttling.bps-write", 0);
+    throttle_cfg->buckets[THROTTLE_OPS_TOTAL].avg =
+        qemu_opt_get_number(opts, "throttling.iops-total", 0);
+    throttle_cfg->buckets[THROTTLE_OPS_READ].avg =
+        qemu_opt_get_number(opts, "throttling.iops-read", 0);
+    throttle_cfg->buckets[THROTTLE_OPS_WRITE].avg =
+        qemu_opt_get_number(opts, "throttling.iops-write", 0);
+
+    throttle_cfg->buckets[THROTTLE_BPS_TOTAL].max =
+        qemu_opt_get_number(opts, "throttling.bps-total-max", 0);
+    throttle_cfg->buckets[THROTTLE_BPS_READ].max  =
+        qemu_opt_get_number(opts, "throttling.bps-read-max", 0);
+    throttle_cfg->buckets[THROTTLE_BPS_WRITE].max =
+        qemu_opt_get_number(opts, "throttling.bps-write-max", 0);
+    throttle_cfg->buckets[THROTTLE_OPS_TOTAL].max =
+        qemu_opt_get_number(opts, "throttling.iops-total-max", 0);
+    throttle_cfg->buckets[THROTTLE_OPS_READ].max =
+        qemu_opt_get_number(opts, "throttling.iops-read-max", 0);
+    throttle_cfg->buckets[THROTTLE_OPS_WRITE].max =
+        qemu_opt_get_number(opts, "throttling.iops-write-max", 0);
+
+    throttle_cfg->op_size =
+        qemu_opt_get_number(opts, "throttling.iops-size", 0);
+
+    *throttling_group = qemu_opt_get(opts, "throttling.group");
+
+    if (!check_throttle_config(throttle_cfg, errp)) {
+        return;
+    }
+
+    *detect_zeroes =
+        qapi_enum_parse(BlockdevDetectZeroesOptions_lookup,
+                        qemu_opt_get(opts, "detect-zeroes"),
+                        BLOCKDEV_DETECT_ZEROES_OPTIONS_MAX,
+                        BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
+                        &local_error);
+    if (local_error) {
+        error_propagate(errp, local_error);
+        return;
+    }
+
+    if (*detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
+        !(*bdrv_flags & BDRV_O_UNMAP))
+    {
+        error_setg(errp, "setting detect-zeroes to unmap is not allowed "
+                         "without setting discard operation to unmap");
+        return;
+    }
+}
+
 /* Takes the ownership of bs_opts */
 static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
                                    Error **errp)
 {
     const char *buf;
-    int ro = 0;
     int bdrv_flags = 0;
     int on_read_error, on_write_error;
     BlockBackend *blk;
     BlockDriverState *bs;
     ThrottleConfig cfg;
     int snapshot = 0;
-    bool copy_on_read;
     Error *error = NULL;
     QemuOpts *opts;
     const char *id;
     bool has_driver_specific_opts;
-    BlockdevDetectZeroesOptions detect_zeroes;
-    const char *throttling_group;
+    BlockdevDetectZeroesOptions detect_zeroes =
+        BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
+    const char *throttling_group = NULL;
 
     /* Check common options by copying from bs_opts to opts, all other options
      * stay in bs_opts for processing by bdrv_open(). */
@@ -393,38 +496,13 @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
 
     /* extract parameters */
     snapshot = qemu_opt_get_bool(opts, "snapshot", 0);
-    ro = qemu_opt_get_bool(opts, "read-only", 0);
-    copy_on_read = qemu_opt_get_bool(opts, "copy-on-read", false);
-
-    if ((buf = qemu_opt_get(opts, "discard")) != NULL) {
-        if (bdrv_parse_discard_flags(buf, &bdrv_flags) != 0) {
-            error_setg(errp, "invalid discard option");
-            goto early_err;
-        }
-    }
 
-    if (qemu_opt_get_bool(opts, BDRV_OPT_CACHE_WB, true)) {
-        bdrv_flags |= BDRV_O_CACHE_WB;
-    }
-    if (qemu_opt_get_bool(opts, BDRV_OPT_CACHE_DIRECT, false)) {
-        bdrv_flags |= BDRV_O_NOCACHE;
-    }
-    if (qemu_opt_get_bool(opts, BDRV_OPT_CACHE_NO_FLUSH, false)) {
-        bdrv_flags |= BDRV_O_NO_FLUSH;
-    }
-
-#ifdef CONFIG_LINUX_AIO
-    if ((buf = qemu_opt_get(opts, "aio")) != NULL) {
-        if (!strcmp(buf, "native")) {
-            bdrv_flags |= BDRV_O_NATIVE_AIO;
-        } else if (!strcmp(buf, "threads")) {
-            /* this is the default */
-        } else {
-           error_setg(errp, "invalid aio option");
-           goto early_err;
-        }
+    extract_common_blockdev_options(opts, &bdrv_flags, &cfg, &detect_zeroes,
+                                    &throttling_group, &error);
+    if (error) {
+        error_propagate(errp, error);
+        goto early_err;
     }
-#endif
 
     if ((buf = qemu_opt_get(opts, "format")) != NULL) {
         if (is_help_option(buf)) {
@@ -441,43 +519,6 @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
         qdict_put(bs_opts, "driver", qstring_from_str(buf));
     }
 
-    /* disk I/O throttling */
-    memset(&cfg, 0, sizeof(cfg));
-    cfg.buckets[THROTTLE_BPS_TOTAL].avg =
-        qemu_opt_get_number(opts, "throttling.bps-total", 0);
-    cfg.buckets[THROTTLE_BPS_READ].avg  =
-        qemu_opt_get_number(opts, "throttling.bps-read", 0);
-    cfg.buckets[THROTTLE_BPS_WRITE].avg =
-        qemu_opt_get_number(opts, "throttling.bps-write", 0);
-    cfg.buckets[THROTTLE_OPS_TOTAL].avg =
-        qemu_opt_get_number(opts, "throttling.iops-total", 0);
-    cfg.buckets[THROTTLE_OPS_READ].avg =
-        qemu_opt_get_number(opts, "throttling.iops-read", 0);
-    cfg.buckets[THROTTLE_OPS_WRITE].avg =
-        qemu_opt_get_number(opts, "throttling.iops-write", 0);
-
-    cfg.buckets[THROTTLE_BPS_TOTAL].max =
-        qemu_opt_get_number(opts, "throttling.bps-total-max", 0);
-    cfg.buckets[THROTTLE_BPS_READ].max  =
-        qemu_opt_get_number(opts, "throttling.bps-read-max", 0);
-    cfg.buckets[THROTTLE_BPS_WRITE].max =
-        qemu_opt_get_number(opts, "throttling.bps-write-max", 0);
-    cfg.buckets[THROTTLE_OPS_TOTAL].max =
-        qemu_opt_get_number(opts, "throttling.iops-total-max", 0);
-    cfg.buckets[THROTTLE_OPS_READ].max =
-        qemu_opt_get_number(opts, "throttling.iops-read-max", 0);
-    cfg.buckets[THROTTLE_OPS_WRITE].max =
-        qemu_opt_get_number(opts, "throttling.iops-write-max", 0);
-
-    cfg.op_size = qemu_opt_get_number(opts, "throttling.iops-size", 0);
-
-    throttling_group = qemu_opt_get(opts, "throttling.group");
-
-    if (!check_throttle_config(&cfg, &error)) {
-        error_propagate(errp, error);
-        goto early_err;
-    }
-
     on_write_error = BLOCKDEV_ON_ERROR_ENOSPC;
     if ((buf = qemu_opt_get(opts, "werror")) != NULL) {
         on_write_error = parse_block_error_action(buf, 0, &error);
@@ -496,40 +537,16 @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
         }
     }
 
-    detect_zeroes =
-        qapi_enum_parse(BlockdevDetectZeroesOptions_lookup,
-                        qemu_opt_get(opts, "detect-zeroes"),
-                        BLOCKDEV_DETECT_ZEROES_OPTIONS_MAX,
-                        BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
-                        &error);
-    if (error) {
-        error_propagate(errp, error);
-        goto early_err;
-    }
-
-    if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
-        !(bdrv_flags & BDRV_O_UNMAP)) {
-        error_setg(errp, "setting detect-zeroes to unmap is not allowed "
-                         "without setting discard operation to unmap");
-        goto early_err;
-    }
-
     if (snapshot) {
         /* always use cache=unsafe with snapshot */
         bdrv_flags &= ~BDRV_O_CACHE_MASK;
         bdrv_flags |= (BDRV_O_SNAPSHOT|BDRV_O_CACHE_WB|BDRV_O_NO_FLUSH);
     }
 
-    if (copy_on_read) {
-        bdrv_flags |= BDRV_O_COPY_ON_READ;
-    }
-
     if (runstate_check(RUN_STATE_INMIGRATE)) {
         bdrv_flags |= BDRV_O_INCOMING;
     }
 
-    bdrv_flags |= ro ? 0 : BDRV_O_RDWR;
-
     /* init */
     if ((!file || !*file) && !has_driver_specific_opts) {
         BlockBackendRootState *blk_rs;
@@ -541,7 +558,7 @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
 
         blk_rs = blk_get_root_state(blk);
         blk_rs->open_flags    = bdrv_flags;
-        blk_rs->read_only     = ro;
+        blk_rs->read_only     = !(bdrv_flags & BDRV_O_RDWR);
         blk_rs->detect_zeroes = detect_zeroes;
 
         if (throttle_enabled(&cfg)) {
-- 
2.5.2

[Qemu-devel] [PATCH v5 25/38] blockdev: Allow more options for BB-less BDS tree

[Max Reitz]

Most of the options which blockdev_init() parses for both the
BlockBackend and the root BDS are valid for just the root BDS as well
(e.g. read-only). This patch allows specifying these options even if not
creating a BlockBackend.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 blockdev.c | 160 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 154 insertions(+), 6 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index 688ee5f..647ce0b 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -612,6 +612,65 @@ err_no_opts:
     return NULL;
 }
 
+static QemuOptsList qemu_root_bds_opts;
+
+/* Takes the ownership of bs_opts */
+static BlockDriverState *bds_tree_init(QDict *bs_opts, Error **errp)
+{
+    BlockDriverState *bs;
+    QemuOpts *opts;
+    Error *local_error = NULL;
+    ThrottleConfig cfg;
+    BlockdevDetectZeroesOptions detect_zeroes;
+    const char *throttling_group = NULL;
+    int ret;
+    int bdrv_flags = 0;
+
+    opts = qemu_opts_create(&qemu_root_bds_opts, NULL, 1, errp);
+    if (!opts) {
+        goto fail;
+    }
+
+    qemu_opts_absorb_qdict(opts, bs_opts, &local_error);
+    if (local_error) {
+        error_propagate(errp, local_error);
+        goto fail;
+    }
+
+    extract_common_blockdev_options(opts, &bdrv_flags, &cfg, &detect_zeroes,
+                                    &throttling_group, &local_error);
+    if (local_error) {
+        error_propagate(errp, local_error);
+        goto fail;
+    }
+
+    bs = NULL;
+    ret = bdrv_open(&bs, NULL, NULL, bs_opts, bdrv_flags, errp);
+    if (ret < 0) {
+        goto fail_no_bs_opts;
+    }
+
+    bs->detect_zeroes = detect_zeroes;
+
+    /* disk I/O throttling */
+    if (throttle_enabled(&cfg)) {
+        if (!throttling_group) {
+            throttling_group = bdrv_get_node_name(bs);
+        }
+        bdrv_io_limits_enable(bs, throttling_group);
+        bdrv_set_io_limits(bs, &cfg);
+    }
+
+fail_no_bs_opts:
+    qemu_opts_del(opts);
+    return bs;
+
+fail:
+    qemu_opts_del(opts);
+    QDECREF(bs_opts);
+    return NULL;
+}
+
 static void qemu_opt_rename(QemuOpts *opts, const char *from, const char *to,
                             Error **errp)
 {
@@ -3170,18 +3229,14 @@ void qmp_blockdev_add(BlockdevOptions *options, Error **errp)
 
         bs = blk_bs(blk);
     } else {
-        int ret;
-
         if (!qdict_get_try_str(qdict, "node-name")) {
             error_setg(errp, "'id' and/or 'node-name' need to be specified for "
                        "the root node");
             goto fail;
         }
 
-        bs = NULL;
-        ret = bdrv_open(&bs, NULL, NULL, qdict, BDRV_O_RDWR | BDRV_O_CACHE_WB,
-                        errp);
-        if (ret < 0) {
+        bs = bds_tree_init(qdict, errp);
+        if (!bs) {
             goto fail;
         }
     }
@@ -3336,6 +3391,99 @@ QemuOptsList qemu_common_drive_opts = {
     },
 };
 
+static QemuOptsList qemu_root_bds_opts = {
+    .name = "root-bds",
+    .head = QTAILQ_HEAD_INITIALIZER(qemu_common_drive_opts.head),
+    .desc = {
+        {
+            .name = "discard",
+            .type = QEMU_OPT_STRING,
+            .help = "discard operation (ignore/off, unmap/on)",
+        },{
+            .name = "cache.writeback",
+            .type = QEMU_OPT_BOOL,
+            .help = "enables writeback mode for any caches",
+        },{
+            .name = "cache.direct",
+            .type = QEMU_OPT_BOOL,
+            .help = "enables use of O_DIRECT (bypass the host page cache)",
+        },{
+            .name = "cache.no-flush",
+            .type = QEMU_OPT_BOOL,
+            .help = "ignore any flush requests for the device",
+        },{
+            .name = "aio",
+            .type = QEMU_OPT_STRING,
+            .help = "host AIO implementation (threads, native)",
+        },{
+            .name = "read-only",
+            .type = QEMU_OPT_BOOL,
+            .help = "open drive file as read-only",
+        },{
+            .name = "throttling.iops-total",
+            .type = QEMU_OPT_NUMBER,
+            .help = "limit total I/O operations per second",
+        },{
+            .name = "throttling.iops-read",
+            .type = QEMU_OPT_NUMBER,
+            .help = "limit read operations per second",
+        },{
+            .name = "throttling.iops-write",
+            .type = QEMU_OPT_NUMBER,
+            .help = "limit write operations per second",
+        },{
+            .name = "throttling.bps-total",
+            .type = QEMU_OPT_NUMBER,
+            .help = "limit total bytes per second",
+        },{
+            .name = "throttling.bps-read",
+            .type = QEMU_OPT_NUMBER,
+            .help = "limit read bytes per second",
+        },{
+            .name = "throttling.bps-write",
+            .type = QEMU_OPT_NUMBER,
+            .help = "limit write bytes per second",
+        },{
+            .name = "throttling.iops-total-max",
+            .type = QEMU_OPT_NUMBER,
+            .help = "I/O operations burst",
+        },{
+            .name = "throttling.iops-read-max",
+            .type = QEMU_OPT_NUMBER,
+            .help = "I/O operations read burst",
+        },{
+            .name = "throttling.iops-write-max",
+            .type = QEMU_OPT_NUMBER,
+            .help = "I/O operations write burst",
+        },{
+            .name = "throttling.bps-total-max",
+            .type = QEMU_OPT_NUMBER,
+            .help = "total bytes burst",
+        },{
+            .name = "throttling.bps-read-max",
+            .type = QEMU_OPT_NUMBER,
+            .help = "total bytes read burst",
+        },{
+            .name = "throttling.bps-write-max",
+            .type = QEMU_OPT_NUMBER,
+            .help = "total bytes write burst",
+        },{
+            .name = "throttling.iops-size",
+            .type = QEMU_OPT_NUMBER,
+            .help = "when limiting by iops max size of an I/O in bytes",
+        },{
+            .name = "copy-on-read",
+            .type = QEMU_OPT_BOOL,
+            .help = "copy read data from backing file into image file",
+        },{
+            .name = "detect-zeroes",
+            .type = QEMU_OPT_STRING,
+            .help = "try to optimize zero writes (off, on, unmap)",
+        },
+        { /* end of list */ }
+    },
+};
+
 QemuOptsList qemu_drive_opts = {
     .name = "drive",
     .head = QTAILQ_HEAD_INITIALIZER(qemu_drive_opts.head),
-- 
2.5.2

[Qemu-devel] [PATCH v5 26/38] block: Add blk_remove_bs()

[Max Reitz]

This function removes the BlockDriverState associated with the given
BlockBackend from that BB and sets the BDS pointer in the BB to NULL.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 block/block-backend.c          | 22 +++++++++++++++++++++-
 include/sysemu/block-backend.h |  1 +
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/block/block-backend.c b/block/block-backend.c
index 652385e..66ecc07 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -314,6 +314,22 @@ void blk_hide_on_behalf_of_hmp_drive_del(BlockBackend *blk)
 }
 
 /*
+ * Disassociates the currently associated BlockDriverState from @blk.
+ */
+void blk_remove_bs(BlockBackend *blk)
+{
+    if (!blk->bs) {
+        return;
+    }
+
+    blk_update_root_state(blk);
+
+    bdrv_unref(blk->bs);
+    blk->bs->blk = NULL;
+    blk->bs = NULL;
+}
+
+/*
  * Associates a new BlockDriverState with @blk.
  */
 void blk_insert_bs(BlockBackend *blk, BlockDriverState *bs)
@@ -323,9 +339,13 @@ void blk_insert_bs(BlockBackend *blk, BlockDriverState *bs)
     }
 
     assert(!blk->bs);
-    assert(!bs->blk);
     bdrv_ref(bs);
     blk->bs = bs;
+
+    if (bs->blk) {
+        blk_remove_bs(bs->blk);
+    }
+
     bs->blk = blk;
 }
 
diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
index 9306a52..14a6d32 100644
--- a/include/sysemu/block-backend.h
+++ b/include/sysemu/block-backend.h
@@ -72,6 +72,7 @@ BlockBackend *blk_by_name(const char *name);
 BlockBackend *blk_next(BlockBackend *blk);
 
 BlockDriverState *blk_bs(BlockBackend *blk);
+void blk_remove_bs(BlockBackend *blk);
 void blk_insert_bs(BlockBackend *blk, BlockDriverState *bs);
 
 void blk_hide_on_behalf_of_hmp_drive_del(BlockBackend *blk);
-- 
2.5.2

[Qemu-devel] [PATCH v5 27/38] blockdev: Add blockdev-open-tray

[Max Reitz]

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 blockdev.c           | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 qapi/block-core.json | 23 +++++++++++++++++++++++
 qmp-commands.hx      | 39 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 111 insertions(+)

diff --git a/blockdev.c b/blockdev.c
index 647ce0b..6bc5841 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2059,6 +2059,55 @@ out:
     aio_context_release(aio_context);
 }
 
+void qmp_blockdev_open_tray(const char *device, bool has_force, bool force,
+                            Error **errp)
+{
+    BlockBackend *blk;
+    BlockDriverState *bs;
+    AioContext *aio_context = NULL;
+
+    if (!has_force) {
+        force = false;
+    }
+
+    blk = blk_by_name(device);
+    if (!blk) {
+        error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
+                  "Device '%s' not found", device);
+        return;
+    }
+
+    if (!blk_dev_has_removable_media(blk)) {
+        error_setg(errp, "Device '%s' is not removable", device);
+        return;
+    }
+
+    if (blk_dev_is_tray_open(blk)) {
+        return;
+    }
+
+    bs = blk_bs(blk);
+    if (bs) {
+        aio_context = bdrv_get_aio_context(bs);
+        aio_context_acquire(aio_context);
+
+        if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_EJECT, errp)) {
+            goto out;
+        }
+    }
+
+    if (blk_dev_is_medium_locked(blk)) {
+        blk_dev_eject_request(blk, force);
+    } else {
+        blk_dev_change_media_cb(blk, false);
+    }
+
+out:
+    if (aio_context) {
+        aio_context_release(aio_context);
+    }
+}
+
 /* throttling disk I/O limits */
 void qmp_block_set_io_throttle(const char *device, int64_t bps, int64_t bps_rd,
                                int64_t bps_wr,
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 425fdab..b9b4a24 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1876,6 +1876,29 @@
 ##
 { 'command': 'blockdev-add', 'data': { 'options': 'BlockdevOptions' } }
 
+##
+# @blockdev-open-tray:
+#
+# Opens a block device's tray. If there is a block driver state tree inserted as
+# a medium, it will become inaccessible to the guest (but it will remain
+# associated to the block device, so closing the tray will make it accessible
+# again).
+#
+# If the tray was already open before, this will be a no-op.
+#
+# @device: block device name
+#
+# @force:  #optional if false (the default), an eject request will be sent to
+#          the guest if it has locked the tray (and the tray will not be opened
+#          immediately); if true, the tray will be opened regardless of whether
+#          it is locked
+#
+# Since: 2.5
+##
+{ 'command': 'blockdev-open-tray',
+  'data': { 'device': 'str',
+            '*force': 'bool' } }
+
 
 ##
 # @BlockErrorAction
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 8343289..f6ea5ea 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -3897,6 +3897,45 @@ Example (2):
 EQMP
 
     {
+        .name       = "blockdev-open-tray",
+        .args_type  = "device:s,force:b?",
+        .mhandler.cmd_new = qmp_marshal_input_blockdev_open_tray,
+    },
+
+SQMP
+blockdev-open-tray
+------------------
+
+Opens a block device's tray. If there is a block driver state tree inserted as a
+medium, it will become inaccessible to the guest (but it will remain associated
+to the block device, so closing the tray will make it accessible again).
+
+If the tray was already open before, this will be a no-op.
+
+Arguments:
+
+- "device": block device name (json-string)
+- "force": if false (the default), an eject request will be sent to the guest if
+           it has locked the tray (and the tray will not be opened immediately);
+           if true, the tray will be opened regardless of whether it is locked
+           (json-bool, optional)
+
+Example:
+
+-> { "execute": "blockdev-open-tray",
+     "arguments": { "device": "ide1-cd0" } }
+
+<- { "timestamp": { "seconds": 1418751016,
+                    "microseconds": 716996 },
+     "event": "DEVICE_TRAY_MOVED",
+     "data": { "device": "ide1-cd0",
+               "tray-open": true } }
+
+<- { "return": {} }
+
+EQMP
+
+    {
         .name       = "query-named-block-nodes",
         .args_type  = "",
         .mhandler.cmd_new = qmp_marshal_input_query_named_block_nodes,
-- 
2.5.2

[Qemu-devel] [PATCH v5 28/38] blockdev: Add blockdev-close-tray

[Max Reitz]

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 blockdev.c           | 23 +++++++++++++++++++++++
 qapi/block-core.json | 16 ++++++++++++++++
 qmp-commands.hx      | 35 +++++++++++++++++++++++++++++++++++
 3 files changed, 74 insertions(+)

diff --git a/blockdev.c b/blockdev.c
index 6bc5841..d07bf8a 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2108,6 +2108,29 @@ out:
     }
 }
 
+void qmp_blockdev_close_tray(const char *device, Error **errp)
+{
+    BlockBackend *blk;
+
+    blk = blk_by_name(device);
+    if (!blk) {
+        error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
+                  "Device '%s' not found", device);
+        return;
+    }
+
+    if (!blk_dev_has_removable_media(blk)) {
+        error_setg(errp, "Device '%s' is not removable", device);
+        return;
+    }
+
+    if (!blk_dev_is_tray_open(blk)) {
+        return;
+    }
+
+    blk_dev_change_media_cb(blk, true);
+}
+
 /* throttling disk I/O limits */
 void qmp_block_set_io_throttle(const char *device, int64_t bps, int64_t bps_rd,
                                int64_t bps_wr,
diff --git a/qapi/block-core.json b/qapi/block-core.json
index b9b4a24..1a51829 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1899,6 +1899,22 @@
   'data': { 'device': 'str',
             '*force': 'bool' } }
 
+##
+# @blockdev-close-tray:
+#
+# Closes a block device's tray. If there is a block driver state tree associated
+# with the block device (which is currently ejected), that tree will be loaded
+# as the medium.
+#
+# If the tray was already closed before, this will be a no-op.
+#
+# @device: block device name
+#
+# Since: 2.5
+##
+{ 'command': 'blockdev-close-tray',
+  'data': { 'device': 'str' } }
+
 
 ##
 # @BlockErrorAction
diff --git a/qmp-commands.hx b/qmp-commands.hx
index f6ea5ea..7c7125a 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -3936,6 +3936,41 @@ Example:
 EQMP
 
     {
+        .name       = "blockdev-close-tray",
+        .args_type  = "device:s",
+        .mhandler.cmd_new = qmp_marshal_input_blockdev_close_tray,
+    },
+
+SQMP
+blockdev-close-tray
+-------------------
+
+Closes a block device's tray. If there is a block driver state tree associated
+with the block device (which is currently ejected), that tree will be loaded as
+the medium.
+
+If the tray was already closed before, this will be a no-op.
+
+Arguments:
+
+- "device": block device name (json-string)
+
+Example:
+
+-> { "execute": "blockdev-close-tray",
+     "arguments": { "device": "ide1-cd0" } }
+
+<- { "timestamp": { "seconds": 1418751345,
+                    "microseconds": 272147 },
+     "event": "DEVICE_TRAY_MOVED",
+     "data": { "device": "ide1-cd0",
+               "tray-open": false } }
+
+<- { "return": {} }
+
+EQMP
+
+    {
         .name       = "query-named-block-nodes",
         .args_type  = "",
         .mhandler.cmd_new = qmp_marshal_input_query_named_block_nodes,
-- 
2.5.2

[Qemu-devel] [PATCH v5 29/38] blockdev: Add blockdev-remove-medium

[Max Reitz]

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 blockdev.c           | 30 ++++++++++++++++++++++++++++++
 qapi/block-core.json | 15 +++++++++++++++
 qmp-commands.hx      | 45 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 90 insertions(+)

diff --git a/blockdev.c b/blockdev.c
index d07bf8a..b7835e4 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2131,6 +2131,36 @@ void qmp_blockdev_close_tray(const char *device, Error **errp)
     blk_dev_change_media_cb(blk, true);
 }
 
+void qmp_blockdev_remove_medium(const char *device, Error **errp)
+{
+    BlockBackend *blk;
+    bool has_device;
+
+    blk = blk_by_name(device);
+    if (!blk) {
+        error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
+                  "Device '%s' not found", device);
+        return;
+    }
+
+    /* For BBs without a device, we can exchange the BDS tree at will */
+    has_device = blk_get_attached_dev(blk);
+
+    if (has_device && !blk_dev_has_removable_media(blk)) {
+        error_setg(errp, "Device '%s' is not removable", device);
+        return;
+    }
+
+    if (has_device && !blk_dev_is_tray_open(blk)) {
+        error_setg(errp, "Tray of device '%s' is not open", device);
+        return;
+    }
+
+    if (blk_bs(blk)) {
+        blk_remove_bs(blk);
+    }
+}
+
 /* throttling disk I/O limits */
 void qmp_block_set_io_throttle(const char *device, int64_t bps, int64_t bps_rd,
                                int64_t bps_wr,
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 1a51829..8edf5d9 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1915,6 +1915,21 @@
 { 'command': 'blockdev-close-tray',
   'data': { 'device': 'str' } }
 
+##
+# @blockdev-remove-medium:
+#
+# Removes a medium (a block driver state tree) from a block device. That block
+# device's tray must currently be open.
+#
+# If the tray is open and there is no medium inserted, this will be a no-op.
+#
+# @device: block device name
+#
+# Since: 2.5
+##
+{ 'command': 'blockdev-remove-medium',
+  'data': { 'device': 'str' } }
+
 
 ##
 # @BlockErrorAction
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 7c7125a..a9594a7 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -3971,6 +3971,51 @@ Example:
 EQMP
 
     {
+        .name       = "blockdev-remove-medium",
+        .args_type  = "device:s",
+        .mhandler.cmd_new = qmp_marshal_input_blockdev_remove_medium,
+    },
+
+SQMP
+blockdev-remove-medium
+----------------------
+
+Removes a medium (a block driver state tree) from a block device. That block
+device's tray must currently be open.
+
+If the tray is open and there is no medium inserted, this will be a no-op.
+
+Arguments:
+
+- "device": block device name (json-string)
+
+Example:
+
+-> { "execute": "blockdev-remove-medium",
+     "arguments": { "device": "ide1-cd0" } }
+
+<- { "error": { "class": "GenericError",
+                "desc": "Tray of device 'ide1-cd0' is not open" } }
+
+-> { "execute": "blockdev-open-tray",
+     "arguments": { "device": "ide1-cd0" } }
+
+<- { "timestamp": { "seconds": 1418751627,
+                    "microseconds": 549958 },
+     "event": "DEVICE_TRAY_MOVED",
+     "data": { "device": "ide1-cd0",
+               "tray-open": true } }
+
+<- { "return": {} }
+
+-> { "execute": "blockdev-remove-medium",
+     "arguments": { "device": "ide1-cd0" } }
+
+<- { "return": {} }
+
+EQMP
+
+    {
         .name       = "query-named-block-nodes",
         .args_type  = "",
         .mhandler.cmd_new = qmp_marshal_input_query_named_block_nodes,
-- 
2.5.2

[Qemu-devel] [PATCH v5 30/38] blockdev: Add blockdev-insert-medium

[Max Reitz]

And a helper function for that, which directly takes a pointer to the
BDS to be inserted instead of its node-name (which will be used for
implementing 'change' using blockdev-insert-medium).

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 blockdev.c           | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 qapi/block-core.json | 17 +++++++++++++++++
 qmp-commands.hx      | 37 +++++++++++++++++++++++++++++++++++++
 3 files changed, 102 insertions(+)

diff --git a/blockdev.c b/blockdev.c
index b7835e4..bbcea00 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2161,6 +2161,54 @@ void qmp_blockdev_remove_medium(const char *device, Error **errp)
     }
 }
 
+static void qmp_blockdev_insert_anon_medium(const char *device,
+                                            BlockDriverState *bs, Error **errp)
+{
+    BlockBackend *blk;
+    bool has_device;
+
+    blk = blk_by_name(device);
+    if (!blk) {
+        error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
+                  "Device '%s' not found", device);
+        return;
+    }
+
+    /* For BBs without a device, we can exchange the BDS tree at will */
+    has_device = blk_get_attached_dev(blk);
+
+    if (has_device && !blk_dev_has_removable_media(blk)) {
+        error_setg(errp, "Device '%s' is not removable", device);
+        return;
+    }
+
+    if (has_device && !blk_dev_is_tray_open(blk)) {
+        error_setg(errp, "Tray of device '%s' is not open", device);
+        return;
+    }
+
+    if (blk_bs(blk)) {
+        error_setg(errp, "There already is a medium in device '%s'", device);
+        return;
+    }
+
+    blk_insert_bs(blk, bs);
+}
+
+void qmp_blockdev_insert_medium(const char *device, const char *node_name,
+                                Error **errp)
+{
+    BlockDriverState *bs;
+
+    bs = bdrv_find_node(node_name);
+    if (!bs) {
+        error_setg(errp, "Node '%s' not found", node_name);
+        return;
+    }
+
+    qmp_blockdev_insert_anon_medium(device, bs, errp);
+}
+
 /* throttling disk I/O limits */
 void qmp_block_set_io_throttle(const char *device, int64_t bps, int64_t bps_rd,
                                int64_t bps_wr,
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 8edf5d9..81a1f19 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1930,6 +1930,23 @@
 { 'command': 'blockdev-remove-medium',
   'data': { 'device': 'str' } }
 
+##
+# @blockdev-insert-medium:
+#
+# Inserts a medium (a block driver state tree) into a block device. That block
+# device's tray must currently be open and there must be no medium inserted
+# already.
+#
+# @device:    block device name
+#
+# @node-name: name of a node in the block driver state graph
+#
+# Since: 2.5
+##
+{ 'command': 'blockdev-insert-medium',
+  'data': { 'device': 'str',
+            'node-name': 'str'} }
+
 
 ##
 # @BlockErrorAction
diff --git a/qmp-commands.hx b/qmp-commands.hx
index a9594a7..38a0f5f 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -4016,6 +4016,43 @@ Example:
 EQMP
 
     {
+        .name       = "blockdev-insert-medium",
+        .args_type  = "device:s,node-name:s",
+        .mhandler.cmd_new = qmp_marshal_input_blockdev_insert_medium,
+    },
+
+SQMP
+blockdev-insert-medium
+----------------------
+
+Inserts a medium (a block driver state tree) into a block device. That block
+device's tray must currently be open and there must be no medium inserted
+already.
+
+Arguments:
+
+- "device": block device name (json-string)
+- "node-name": root node of the BDS tree to insert into the block device
+
+Example:
+
+-> { "execute": "blockdev-add",
+     "arguments": { "options": { "node-name": "node0",
+                                 "driver": "raw",
+                                 "file": { "driver": "file",
+                                           "filename": "fedora.iso" } } } }
+
+<- { "return": {} }
+
+-> { "execute": "blockdev-insert-medium",
+     "arguments": { "device": "ide1-cd0",
+                    "node-name": "node0" } }
+
+<- { "return": {} }
+
+EQMP
+
+    {
         .name       = "query-named-block-nodes",
         .args_type  = "",
         .mhandler.cmd_new = qmp_marshal_input_query_named_block_nodes,
-- 
2.5.2

[Qemu-devel] [PATCH v5 31/38] blockdev: Implement eject with basic operations

[Max Reitz]

Implement 'eject' by calling blockdev-open-tray and
blockdev-remove-medium.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 blockdev.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index bbcea00..2644a4a 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1952,16 +1952,15 @@ out:
 
 void qmp_eject(const char *device, bool has_force, bool force, Error **errp)
 {
-    BlockBackend *blk;
+    Error *local_err = NULL;
 
-    blk = blk_by_name(device);
-    if (!blk) {
-        error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
-                  "Device '%s' not found", device);
+    qmp_blockdev_open_tray(device, has_force, force, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
         return;
     }
 
-    eject_device(blk, force, errp);
+    qmp_blockdev_remove_medium(device, errp);
 }
 
 void qmp_block_passwd(bool has_device, const char *device,
-- 
2.5.2

[Qemu-devel] [PATCH v5 32/38] blockdev: Implement change with basic operations

[Max Reitz]

Implement 'change' on block devices by calling blockdev-open-tray,
blockdev-remove-medium, blockdev-insert-medium (a variation of that
which does not need a node-name) and blockdev-close-tray.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 blockdev.c | 181 +++++++++++++++++++++++++------------------------------------
 1 file changed, 75 insertions(+), 106 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index 2644a4a..3882033 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1915,41 +1915,6 @@ exit:
     }
 }
 
-
-static void eject_device(BlockBackend *blk, int force, Error **errp)
-{
-    BlockDriverState *bs = blk_bs(blk);
-    AioContext *aio_context;
-
-    aio_context = blk_get_aio_context(blk);
-    aio_context_acquire(aio_context);
-
-    if (bs && bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_EJECT, errp)) {
-        goto out;
-    }
-    if (!blk_dev_has_removable_media(blk)) {
-        error_setg(errp, "Device '%s' is not removable",
-                   bdrv_get_device_name(bs));
-        goto out;
-    }
-
-    if (blk_dev_is_medium_locked(blk) && !blk_dev_is_tray_open(blk)) {
-        blk_dev_eject_request(blk, force);
-        if (!force) {
-            error_setg(errp, "Device '%s' is locked",
-                       bdrv_get_device_name(bs));
-            goto out;
-        }
-    }
-
-    if (bs) {
-        bdrv_close(bs);
-    }
-
-out:
-    aio_context_release(aio_context);
-}
-
 void qmp_eject(const char *device, bool has_force, bool force, Error **errp)
 {
     Error *local_err = NULL;
@@ -1987,77 +1952,6 @@ void qmp_block_passwd(bool has_device, const char *device,
     aio_context_release(aio_context);
 }
 
-/* Assumes AioContext is held */
-static void qmp_bdrv_open_encrypted(BlockDriverState **pbs,
-                                    const char *filename,
-                                    int bdrv_flags, const char *format,
-                                    const char *password, Error **errp)
-{
-    BlockDriverState *bs;
-    Error *local_err = NULL;
-    QDict *options = NULL;
-    int ret;
-
-    if (format) {
-        options = qdict_new();
-        qdict_put(options, "driver", qstring_from_str(format));
-    }
-
-    ret = bdrv_open(pbs, filename, NULL, options, bdrv_flags, &local_err);
-    if (ret < 0) {
-        error_propagate(errp, local_err);
-        return;
-    }
-    bs = *pbs;
-
-    bdrv_add_key(bs, password, errp);
-}
-
-void qmp_change_blockdev(const char *device, const char *filename,
-                         const char *format, Error **errp)
-{
-    BlockBackend *blk;
-    BlockDriverState *bs;
-    AioContext *aio_context;
-    int bdrv_flags;
-    bool new_bs;
-    Error *err = NULL;
-
-    blk = blk_by_name(device);
-    if (!blk) {
-        error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
-                  "Device '%s' not found", device);
-        return;
-    }
-    bs = blk_bs(blk);
-    new_bs = !bs;
-
-    aio_context = blk_get_aio_context(blk);
-    aio_context_acquire(aio_context);
-
-    eject_device(blk, 0, &err);
-    if (err) {
-        error_propagate(errp, err);
-        goto out;
-    }
-
-    bdrv_flags = blk_is_read_only(blk) ? 0 : BDRV_O_RDWR;
-    bdrv_flags |= blk_get_root_state(blk)->open_flags & ~BDRV_O_RDWR;
-
-    qmp_bdrv_open_encrypted(&bs, filename, bdrv_flags, format, NULL, &err);
-    if (err) {
-        error_propagate(errp, err);
-    } else if (new_bs) {
-        blk_insert_bs(blk, bs);
-        /* Has been sent automatically by bdrv_open() if blk_bs(blk) was not
-         * NULL */
-        blk_dev_change_media_cb(blk, true);
-    }
-
-out:
-    aio_context_release(aio_context);
-}
-
 void qmp_blockdev_open_tray(const char *device, bool has_force, bool force,
                             Error **errp)
 {
@@ -2208,6 +2102,81 @@ void qmp_blockdev_insert_medium(const char *device, const char *node_name,
     qmp_blockdev_insert_anon_medium(device, bs, errp);
 }
 
+void qmp_change_blockdev(const char *device, const char *filename,
+                         const char *format, Error **errp)
+{
+    BlockBackend *blk;
+    BlockBackendRootState *blk_rs;
+    BlockDriverState *medium_bs = NULL;
+    int bdrv_flags, ret;
+    QDict *options = NULL;
+    Error *err = NULL;
+
+    blk = blk_by_name(device);
+    if (!blk) {
+        error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
+                  "Device '%s' not found", device);
+        goto fail;
+    }
+
+    if (blk_bs(blk)) {
+        blk_update_root_state(blk);
+    }
+
+    blk_rs = blk_get_root_state(blk);
+    bdrv_flags = blk_rs->read_only ? 0 : BDRV_O_RDWR;
+    bdrv_flags |= blk_rs->open_flags & ~BDRV_O_RDWR;
+
+    if (format) {
+        options = qdict_new();
+        qdict_put(options, "driver", qstring_from_str(format));
+    }
+
+    assert(!medium_bs);
+    ret = bdrv_open(&medium_bs, filename, NULL, options, bdrv_flags, errp);
+    if (ret < 0) {
+        goto fail;
+    }
+
+    medium_bs->detect_zeroes = blk_rs->detect_zeroes;
+    if (blk_rs->io_limits_enabled) {
+        bdrv_io_limits_enable(medium_bs, blk_rs->throttle_group_name);
+        bdrv_set_io_limits(medium_bs, &blk_rs->throttle_config);
+    }
+
+    bdrv_add_key(medium_bs, NULL, &err);
+    if (err) {
+        error_propagate(errp, err);
+        goto fail;
+    }
+
+    qmp_blockdev_open_tray(device, false, false, &err);
+    if (err) {
+        error_propagate(errp, err);
+        goto fail;
+    }
+
+    qmp_blockdev_remove_medium(device, &err);
+    if (err) {
+        error_propagate(errp, err);
+        goto fail;
+    }
+
+    qmp_blockdev_insert_anon_medium(device, medium_bs, &err);
+    if (err) {
+        error_propagate(errp, err);
+        goto fail;
+    }
+
+    qmp_blockdev_close_tray(device, errp);
+
+fail:
+    /* If the medium has been inserted, the device has its own reference, so
+     * ours must be relinquished; and if it has not been inserted successfully,
+     * the reference must be relinquished anyway */
+    bdrv_unref(medium_bs);
+}
+
 /* throttling disk I/O limits */
 void qmp_block_set_io_throttle(const char *device, int64_t bps, int64_t bps_rd,
                                int64_t bps_wr,
-- 
2.5.2

[Qemu-devel] [PATCH v5 33/38] block: Inquire tray state before tray-moved events

[Max Reitz]

blk_dev_change_media_cb() is called for all potential tray movements;
however, it is possible to request closing the tray but nothing actually
happening (on a floppy disk drive without a medium).

Thus, the actual tray status should be inquired before sending a
tray-moved event (and an event should be sent whenever the status
changed).

Checking @load is now superfluous; it was necessary because it was
possible to change a medium without having explicitly opened the tray
and closed it again (or it might have been possible, at least). This is
no longer possible, though.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 block/block-backend.c | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/block/block-backend.c b/block/block-backend.c
index 66ecc07..09efb8b 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -422,18 +422,15 @@ void blk_set_dev_ops(BlockBackend *blk, const BlockDevOps *ops,
 void blk_dev_change_media_cb(BlockBackend *blk, bool load)
 {
     if (blk->dev_ops && blk->dev_ops->change_media_cb) {
-        bool tray_was_closed = !blk_dev_is_tray_open(blk);
+        bool tray_was_open, tray_is_open;
 
+        tray_was_open = blk_dev_is_tray_open(blk);
         blk->dev_ops->change_media_cb(blk->dev_opaque, load);
-        if (tray_was_closed) {
-            /* tray open */
-            qapi_event_send_device_tray_moved(blk_name(blk),
-                                              true, &error_abort);
-        }
-        if (load) {
-            /* tray close */
-            qapi_event_send_device_tray_moved(blk_name(blk),
-                                              false, &error_abort);
+        tray_is_open = blk_dev_is_tray_open(blk);
+
+        if (tray_was_open != tray_is_open) {
+            qapi_event_send_device_tray_moved(blk_name(blk), tray_is_open,
+                                              &error_abort);
         }
     }
 }
-- 
2.5.2

[Qemu-devel] [PATCH v5 34/38] qmp: Introduce blockdev-change-medium

[Max Reitz]

Introduce a new QMP command 'blockdev-change-medium' which is intended
to replace the 'change' command for block devices. The existing function
qmp_change_blockdev() is accordingly renamed to
qmp_blockdev_change_medium().

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 blockdev.c                |  7 ++++---
 include/sysemu/blockdev.h |  2 --
 qapi-schema.json          |  6 ++++--
 qapi/block-core.json      | 23 +++++++++++++++++++++++
 qmp-commands.hx           | 31 +++++++++++++++++++++++++++++++
 qmp.c                     |  2 +-
 6 files changed, 63 insertions(+), 8 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index 3882033..2ef0745 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2102,8 +2102,9 @@ void qmp_blockdev_insert_medium(const char *device, const char *node_name,
     qmp_blockdev_insert_anon_medium(device, bs, errp);
 }
 
-void qmp_change_blockdev(const char *device, const char *filename,
-                         const char *format, Error **errp)
+void qmp_blockdev_change_medium(const char *device, const char *filename,
+                                bool has_format, const char *format,
+                                Error **errp)
 {
     BlockBackend *blk;
     BlockBackendRootState *blk_rs;
@@ -2127,7 +2128,7 @@ void qmp_change_blockdev(const char *device, const char *filename,
     bdrv_flags = blk_rs->read_only ? 0 : BDRV_O_RDWR;
     bdrv_flags |= blk_rs->open_flags & ~BDRV_O_RDWR;
 
-    if (format) {
+    if (has_format) {
         options = qdict_new();
         qdict_put(options, "driver", qstring_from_str(format));
     }
diff --git a/include/sysemu/blockdev.h b/include/sysemu/blockdev.h
index 3104150..553b53c 100644
--- a/include/sysemu/blockdev.h
+++ b/include/sysemu/blockdev.h
@@ -63,8 +63,6 @@ DriveInfo *drive_new(QemuOpts *arg, BlockInterfaceType block_default_type);
 
 /* device-hotplug */
 
-void qmp_change_blockdev(const char *device, const char *filename,
-                         const char *format, Error **errp);
 void hmp_commit(Monitor *mon, const QDict *qdict);
 void hmp_drive_del(Monitor *mon, const QDict *qdict);
 #endif
diff --git a/qapi-schema.json b/qapi-schema.json
index 2bada60..0d5190b 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1809,8 +1809,10 @@
 #          device's password.  The behavior of reads and writes to the block
 #          device between when these calls are executed is undefined.
 #
-# Notes:  It is strongly recommended that this interface is not used especially
-#         for changing block devices.
+# Notes:  This interface is deprecated, and it is strongly recommended that you
+#         avoid using it.  For changing block devices, use
+#         blockdev-change-medium; for changing VNC parameters, use
+#         change-vnc-password.
 #
 # Since: 0.14.0
 ##
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 81a1f19..b8cc18a 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1949,6 +1949,29 @@
 
 
 ##
+# @blockdev-change-medium:
+#
+# Changes the medium inserted into a block device by ejecting the current medium
+# and loading a new image file which is inserted as the new medium (this command
+# combines blockdev-open-tray, blockdev-remove-medium, blockdev-insert-medium
+# and blockdev-close-tray).
+#
+# @device:          block device name
+#
+# @filename:        filename of the new image to be loaded
+#
+# @format:          #optional, format to open the new image with (defaults to
+#                   the probed format)
+#
+# Since: 2.5
+##
+{ 'command': 'blockdev-change-medium',
+  'data': { 'device': 'str',
+            'filename': 'str',
+            '*format': 'str' } }
+
+
+##
 # @BlockErrorAction
 #
 # An enumeration of action that has been taken when a DISK I/O occurs
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 38a0f5f..538b3d1 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -4115,6 +4115,37 @@ Example:
 EQMP
 
     {
+        .name       = "blockdev-change-medium",
+        .args_type  = "device:B,filename:F,format:s?",
+        .mhandler.cmd_new = qmp_marshal_input_blockdev_change_medium,
+    },
+
+SQMP
+blockdev-change-medium
+----------------------
+
+Changes the medium inserted into a block device by ejecting the current medium
+and loading a new image file which is inserted as the new medium.
+
+Arguments:
+
+- "device": device name (json-string)
+- "filename": filename of the new image (json-string)
+- "format": format of the new image (json-string, optional)
+
+Examples:
+
+1. Change a removable medium
+
+-> { "execute": "blockdev-change-medium",
+             "arguments": { "device": "ide1-cd0",
+                            "filename": "/srv/images/Fedora-12-x86_64-DVD.iso",
+                            "format": "raw" } }
+<- { "return": {} }
+
+EQMP
+
+    {
         .name       = "query-memdev",
         .args_type  = "",
         .mhandler.cmd_new = qmp_marshal_input_query_memdev,
diff --git a/qmp.c b/qmp.c
index 8c3dca8..941fc39 100644
--- a/qmp.c
+++ b/qmp.c
@@ -419,7 +419,7 @@ void qmp_change(const char *device, const char *target,
     if (strcmp(device, "vnc") == 0) {
         qmp_change_vnc(target, has_arg, arg, errp);
     } else {
-        qmp_change_blockdev(device, target, arg, errp);
+        qmp_blockdev_change_medium(device, target, has_arg, arg, errp);
     }
 }
 
-- 
2.5.2

[Qemu-devel] [PATCH v5 35/38] hmp: Use blockdev-change-medium for change command

[Max Reitz]

Use separate code paths for the two overloaded functions of the 'change'
HMP command, and invoke the 'blockdev-change-medium' QMP command if used
on a block device (by calling qmp_blockdev_change_medium()).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 hmp.c | 27 +++++++++++++++------------
 1 file changed, 15 insertions(+), 12 deletions(-)

diff --git a/hmp.c b/hmp.c
index 3f807b7..a753a0f 100644
--- a/hmp.c
+++ b/hmp.c
@@ -1317,22 +1317,25 @@ void hmp_change(Monitor *mon, const QDict *qdict)
     const char *arg = qdict_get_try_str(qdict, "arg");
     Error *err = NULL;
 
-    if (strcmp(device, "vnc") == 0 &&
-            (strcmp(target, "passwd") == 0 ||
-             strcmp(target, "password") == 0)) {
-        if (!arg) {
-            monitor_read_password(mon, hmp_change_read_arg, NULL);
+    if (strcmp(device, "vnc") == 0) {
+        if (strcmp(target, "passwd") == 0 ||
+            strcmp(target, "password") == 0) {
+            if (!arg) {
+                monitor_read_password(mon, hmp_change_read_arg, NULL);
+                return;
+            }
+        }
+        qmp_change("vnc", target, !!arg, arg, &err);
+    } else {
+        qmp_blockdev_change_medium(device, target, !!arg, arg, &err);
+        if (err &&
+            error_get_class(err) == ERROR_CLASS_DEVICE_ENCRYPTED) {
+            error_free(err);
+            monitor_read_block_device_key(mon, device, NULL, NULL);
             return;
         }
     }
 
-    qmp_change(device, target, !!arg, arg, &err);
-    if (err &&
-        error_get_class(err) == ERROR_CLASS_DEVICE_ENCRYPTED) {
-        error_free(err);
-        monitor_read_block_device_key(mon, device, NULL, NULL);
-        return;
-    }
     hmp_handle_error(mon, &err);
 }
 
-- 
2.5.2

[Qemu-devel] [PATCH v5 36/38] blockdev: read-only-mode for blockdev-change-medium

[Max Reitz]

Add an option to qmp_blockdev_change_medium() which allows changing the
read-only status of the block device whose medium is changed.

Some drives do not have a inherently fixed read-only status; for
instance, floppy disks can be set read-only or writable independently of
the drive. Some users may find it useful to be able to therefore change
the read-only status of a block device when changing the medium.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 blockdev.c           | 25 ++++++++++++++++++++++++-
 hmp.c                |  2 +-
 qapi/block-core.json | 24 +++++++++++++++++++++++-
 qmp-commands.hx      | 24 +++++++++++++++++++++++-
 qmp.c                |  3 ++-
 5 files changed, 73 insertions(+), 5 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index 2ef0745..4731843 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2104,6 +2104,8 @@ void qmp_blockdev_insert_medium(const char *device, const char *node_name,
 
 void qmp_blockdev_change_medium(const char *device, const char *filename,
                                 bool has_format, const char *format,
+                                bool has_read_only,
+                                BlockdevChangeReadOnlyMode read_only,
                                 Error **errp)
 {
     BlockBackend *blk;
@@ -2125,7 +2127,28 @@ void qmp_blockdev_change_medium(const char *device, const char *filename,
     }
 
     blk_rs = blk_get_root_state(blk);
-    bdrv_flags = blk_rs->read_only ? 0 : BDRV_O_RDWR;
+
+    if (!has_read_only) {
+        read_only = BLOCKDEV_CHANGE_READ_ONLY_MODE_RETAIN;
+    }
+
+    switch (read_only) {
+    case BLOCKDEV_CHANGE_READ_ONLY_MODE_RETAIN:
+        bdrv_flags = blk_rs->read_only ? 0 : BDRV_O_RDWR;
+        break;
+
+    case BLOCKDEV_CHANGE_READ_ONLY_MODE_READ_ONLY:
+        bdrv_flags = 0;
+        break;
+
+    case BLOCKDEV_CHANGE_READ_ONLY_MODE_READ_WRITE:
+        bdrv_flags = BDRV_O_RDWR;
+        break;
+
+    default:
+        abort();
+    }
+
     bdrv_flags |= blk_rs->open_flags & ~BDRV_O_RDWR;
 
     if (has_format) {
diff --git a/hmp.c b/hmp.c
index a753a0f..5ea7ef2 100644
--- a/hmp.c
+++ b/hmp.c
@@ -1327,7 +1327,7 @@ void hmp_change(Monitor *mon, const QDict *qdict)
         }
         qmp_change("vnc", target, !!arg, arg, &err);
     } else {
-        qmp_blockdev_change_medium(device, target, !!arg, arg, &err);
+        qmp_blockdev_change_medium(device, target, !!arg, arg, false, 0, &err);
         if (err &&
             error_get_class(err) == ERROR_CLASS_DEVICE_ENCRYPTED) {
             error_free(err);
diff --git a/qapi/block-core.json b/qapi/block-core.json
index b8cc18a..5f12af7 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1949,6 +1949,24 @@
 
 
 ##
+# @BlockdevChangeReadOnlyMode:
+#
+# Specifies the new read-only mode of a block device subject to the
+# @blockdev-change-medium command.
+#
+# @retain:      Retains the current read-only mode
+#
+# @read-only:   Makes the device read-only
+#
+# @read-write:  Makes the device writable
+#
+# Since: 2.3
+##
+{ 'enum': 'BlockdevChangeReadOnlyMode',
+  'data': ['retain', 'read-only', 'read-write'] }
+
+
+##
 # @blockdev-change-medium:
 #
 # Changes the medium inserted into a block device by ejecting the current medium
@@ -1963,12 +1981,16 @@
 # @format:          #optional, format to open the new image with (defaults to
 #                   the probed format)
 #
+# @read-only-mode:  #optional, change the read-only mode of the device; defaults
+#                   to 'retain'
+#
 # Since: 2.5
 ##
 { 'command': 'blockdev-change-medium',
   'data': { 'device': 'str',
             'filename': 'str',
-            '*format': 'str' } }
+            '*format': 'str',
+            '*read-only-mode': 'BlockdevChangeReadOnlyMode' } }
 
 
 ##
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 538b3d1..495670b 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -4116,7 +4116,7 @@ EQMP
 
     {
         .name       = "blockdev-change-medium",
-        .args_type  = "device:B,filename:F,format:s?",
+        .args_type  = "device:B,filename:F,format:s?,read-only-mode:s?",
         .mhandler.cmd_new = qmp_marshal_input_blockdev_change_medium,
     },
 
@@ -4132,6 +4132,8 @@ Arguments:
 - "device": device name (json-string)
 - "filename": filename of the new image (json-string)
 - "format": format of the new image (json-string, optional)
+- "read-only-mode": new read-only mode (json-string, optional)
+          - Possible values: "retain" (default), "read-only", "read-write"
 
 Examples:
 
@@ -4143,6 +4145,26 @@ Examples:
                             "format": "raw" } }
 <- { "return": {} }
 
+2. Load a read-only medium into a writable drive
+
+-> { "execute": "blockdev-change-medium",
+             "arguments": { "device": "isa-fd0",
+                            "filename": "/srv/images/ro.img",
+                            "format": "raw",
+                            "read-only-mode": "retain" } }
+
+<- { "error":
+     { "class": "GenericError",
+       "desc": "Could not open '/srv/images/ro.img': Permission denied" } }
+
+-> { "execute": "blockdev-change-medium",
+             "arguments": { "device": "isa-fd0",
+                            "filename": "/srv/images/ro.img",
+                            "format": "raw",
+                            "read-only-mode": "read-only" } }
+
+<- { "return": {} }
+
 EQMP
 
     {
diff --git a/qmp.c b/qmp.c
index 941fc39..961c739 100644
--- a/qmp.c
+++ b/qmp.c
@@ -419,7 +419,8 @@ void qmp_change(const char *device, const char *target,
     if (strcmp(device, "vnc") == 0) {
         qmp_change_vnc(target, has_arg, arg, errp);
     } else {
-        qmp_blockdev_change_medium(device, target, has_arg, arg, errp);
+        qmp_blockdev_change_medium(device, target, has_arg, arg, false, 0,
+                                   errp);
     }
 }
 
-- 
2.5.2

[Qemu-devel] [PATCH v5 37/38] hmp: Add read-only-mode option to change command

[Max Reitz]

Expose the new read-only-mode option of 'blockdev-change-medium' for the
'change' HMP command.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 hmp-commands.hx | 20 +++++++++++++++++---
 hmp.c           | 22 +++++++++++++++++++++-
 2 files changed, 38 insertions(+), 4 deletions(-)

diff --git a/hmp-commands.hx b/hmp-commands.hx
index a511004..00fb390 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -194,8 +194,8 @@ ETEXI
 
     {
         .name       = "change",
-        .args_type  = "device:B,target:F,arg:s?",
-        .params     = "device filename [format]",
+        .args_type  = "device:B,target:F,arg:s?,read-only-mode:s?",
+        .params     = "device filename [format [read-only-mode]]",
         .help       = "change a removable medium, optional format",
         .mhandler.cmd = hmp_change,
     },
@@ -206,7 +206,7 @@ STEXI
 Change the configuration of a device.
 
 @table @option
-@item change @var{diskdevice} @var{filename} [@var{format}]
+@item change @var{diskdevice} @var{filename} [@var{format} [@var{read-only-mode}]]
 Change the medium for a removable disk device to point to @var{filename}. eg
 
 @example
@@ -215,6 +215,20 @@ Change the medium for a removable disk device to point to @var{filename}. eg
 
 @var{format} is optional.
 
+@var{read-only-mode} may be used to change the read-only status of the device.
+It accepts the following values:
+
+@table @var
+@item retain
+Retains the current status; this is the default.
+
+@item read-only
+Makes the device read-only.
+
+@item read-write
+Makes the device writable.
+@end table
+
 @item change vnc @var{display},@var{options}
 Change the configuration of the VNC server. The valid syntax for @var{display}
 and @var{options} are described at @ref{sec_invocation}. eg
diff --git a/hmp.c b/hmp.c
index 5ea7ef2..6e2bbc8 100644
--- a/hmp.c
+++ b/hmp.c
@@ -27,6 +27,7 @@
 #include "qapi/opts-visitor.h"
 #include "qapi/qmp/qerror.h"
 #include "qapi/string-output-visitor.h"
+#include "qapi/util.h"
 #include "qapi-visit.h"
 #include "ui/console.h"
 #include "block/qapi.h"
@@ -1315,9 +1316,16 @@ void hmp_change(Monitor *mon, const QDict *qdict)
     const char *device = qdict_get_str(qdict, "device");
     const char *target = qdict_get_str(qdict, "target");
     const char *arg = qdict_get_try_str(qdict, "arg");
+    const char *read_only = qdict_get_try_str(qdict, "read-only-mode");
+    BlockdevChangeReadOnlyMode read_only_mode = 0;
     Error *err = NULL;
 
     if (strcmp(device, "vnc") == 0) {
+        if (read_only) {
+            monitor_printf(mon,
+                           "Parameter 'read-only-mode' is invalid for VNC");
+            return;
+        }
         if (strcmp(target, "passwd") == 0 ||
             strcmp(target, "password") == 0) {
             if (!arg) {
@@ -1327,7 +1335,19 @@ void hmp_change(Monitor *mon, const QDict *qdict)
         }
         qmp_change("vnc", target, !!arg, arg, &err);
     } else {
-        qmp_blockdev_change_medium(device, target, !!arg, arg, false, 0, &err);
+        if (read_only) {
+            read_only_mode =
+                qapi_enum_parse(BlockdevChangeReadOnlyMode_lookup,
+                                read_only, BLOCKDEV_CHANGE_READ_ONLY_MODE_MAX,
+                                BLOCKDEV_CHANGE_READ_ONLY_MODE_RETAIN, &err);
+            if (err) {
+                hmp_handle_error(mon, &err);
+                return;
+            }
+        }
+
+        qmp_blockdev_change_medium(device, target, !!arg, arg,
+                                   !!read_only, read_only_mode, &err);
         if (err &&
             error_get_class(err) == ERROR_CLASS_DEVICE_ENCRYPTED) {
             error_free(err);
-- 
2.5.2

[Qemu-devel] [PATCH v5 38/38] iotests: Add test for change-related QMP commands

[Max Reitz]

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 tests/qemu-iotests/118     | 638 +++++++++++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/118.out |   5 +
 tests/qemu-iotests/group   |   1 +
 3 files changed, 644 insertions(+)
 create mode 100755 tests/qemu-iotests/118
 create mode 100644 tests/qemu-iotests/118.out

diff --git a/tests/qemu-iotests/118 b/tests/qemu-iotests/118
new file mode 100755
index 0000000..915e439
--- /dev/null
+++ b/tests/qemu-iotests/118
@@ -0,0 +1,638 @@
+#!/usr/bin/env python
+#
+# Test case for the QMP 'change' command and all other associated
+# commands
+#
+# Copyright (C) 2015 Red Hat, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+import os
+import stat
+import time
+import iotests
+from iotests import qemu_img
+
+old_img = os.path.join(iotests.test_dir, 'test0.img')
+new_img = os.path.join(iotests.test_dir, 'test1.img')
+
+class ChangeBaseClass(iotests.QMPTestCase):
+    has_opened = False
+    has_closed = False
+
+    def process_events(self):
+        for event in self.vm.get_qmp_events(wait=False):
+            if (event['event'] == 'DEVICE_TRAY_MOVED' and
+                event['data']['device'] == 'drive0'):
+                if event['data']['tray-open'] == False:
+                    self.has_closed = True
+                else:
+                    self.has_opened = True
+
+    def wait_for_open(self):
+        timeout = time.clock() + 3
+        while not self.has_opened and time.clock() < timeout:
+            self.process_events()
+        if not self.has_opened:
+            self.fail('Timeout while waiting for the tray to open')
+
+    def wait_for_close(self):
+        timeout = time.clock() + 3
+        while not self.has_closed and time.clock() < timeout:
+            self.process_events()
+        if not self.has_opened:
+            self.fail('Timeout while waiting for the tray to close')
+
+class GeneralChangeTestsBaseClass(ChangeBaseClass):
+    def test_change(self):
+        result = self.vm.qmp('change', device='drive0', target=new_img,
+                                       arg=iotests.imgfmt)
+        self.assert_qmp(result, 'return', {})
+
+        self.wait_for_open()
+        self.wait_for_close()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', False)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', new_img)
+
+    def test_blockdev_change_medium(self):
+        result = self.vm.qmp('blockdev-change-medium', device='drive0',
+                                                       filename=new_img,
+                                                       format=iotests.imgfmt)
+        self.assert_qmp(result, 'return', {})
+
+        self.wait_for_open()
+        self.wait_for_close()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', False)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', new_img)
+
+    def test_eject(self):
+        result = self.vm.qmp('eject', device='drive0', force=True)
+        self.assert_qmp(result, 'return', {})
+
+        self.wait_for_open()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', True)
+        self.assert_qmp_absent(result, 'return[0]/inserted')
+
+    def test_tray_eject_change(self):
+        result = self.vm.qmp('eject', device='drive0', force=True)
+        self.assert_qmp(result, 'return', {})
+
+        self.wait_for_open()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', True)
+        self.assert_qmp_absent(result, 'return[0]/inserted')
+
+        result = self.vm.qmp('blockdev-change-medium', device='drive0',
+                                                       filename=new_img,
+                                                       format=iotests.imgfmt)
+        self.assert_qmp(result, 'return', {})
+
+        self.wait_for_close()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', False)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', new_img)
+
+    def test_tray_open_close(self):
+        result = self.vm.qmp('blockdev-open-tray', device='drive0', force=True)
+        self.assert_qmp(result, 'return', {})
+
+        self.wait_for_open()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', True)
+        if self.was_empty == True:
+            self.assert_qmp_absent(result, 'return[0]/inserted')
+        else:
+            self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
+
+        result = self.vm.qmp('blockdev-close-tray', device='drive0')
+        self.assert_qmp(result, 'return', {})
+
+        if self.has_real_tray or not self.was_empty:
+            self.wait_for_close()
+
+        result = self.vm.qmp('query-block')
+        if self.has_real_tray or not self.was_empty:
+            self.assert_qmp(result, 'return[0]/tray_open', False)
+        else:
+            self.assert_qmp(result, 'return[0]/tray_open', True)
+        if self.was_empty == True:
+            self.assert_qmp_absent(result, 'return[0]/inserted')
+        else:
+            self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
+
+    def test_tray_eject_close(self):
+        result = self.vm.qmp('eject', device='drive0', force=True)
+        self.assert_qmp(result, 'return', {})
+
+        self.wait_for_open()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', True)
+        self.assert_qmp_absent(result, 'return[0]/inserted')
+
+        result = self.vm.qmp('blockdev-close-tray', device='drive0')
+        self.assert_qmp(result, 'return', {})
+
+        if self.has_real_tray:
+            self.wait_for_close()
+
+        result = self.vm.qmp('query-block')
+        if self.has_real_tray:
+            self.assert_qmp(result, 'return[0]/tray_open', False)
+        else:
+            self.assert_qmp(result, 'return[0]/tray_open', True)
+        self.assert_qmp_absent(result, 'return[0]/inserted')
+
+    def test_tray_open_change(self):
+        result = self.vm.qmp('blockdev-open-tray', device='drive0', force=True)
+        self.assert_qmp(result, 'return', {})
+
+        self.wait_for_open()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', True)
+        if self.was_empty == True:
+            self.assert_qmp_absent(result, 'return[0]/inserted')
+        else:
+            self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
+
+        result = self.vm.qmp('blockdev-change-medium', device='drive0',
+                                                       filename=new_img,
+                                                       format=iotests.imgfmt)
+        self.assert_qmp(result, 'return', {})
+
+        self.wait_for_close()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', False)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', new_img)
+
+    def test_cycle(self):
+        result = self.vm.qmp('blockdev-add',
+                             options={'node-name': 'new',
+                                      'driver': iotests.imgfmt,
+                                      'file': {'filename': new_img,
+                                               'driver': 'file'}})
+        self.assert_qmp(result, 'return', {})
+
+        result = self.vm.qmp('blockdev-open-tray', device='drive0', force=True)
+        self.assert_qmp(result, 'return', {})
+
+        self.wait_for_open()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', True)
+        if self.was_empty == True:
+            self.assert_qmp_absent(result, 'return[0]/inserted')
+        else:
+            self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
+
+        result = self.vm.qmp('blockdev-remove-medium', device='drive0')
+        self.assert_qmp(result, 'return', {})
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', True)
+        self.assert_qmp_absent(result, 'return[0]/inserted')
+
+        result = self.vm.qmp('blockdev-insert-medium', device='drive0',
+                                                       node_name='new')
+        self.assert_qmp(result, 'return', {})
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', True)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', new_img)
+
+        result = self.vm.qmp('blockdev-close-tray', device='drive0')
+        self.assert_qmp(result, 'return', {})
+
+        self.wait_for_close()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', False)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', new_img)
+
+    def test_close_on_closed(self):
+        result = self.vm.qmp('blockdev-close-tray', device='drive0')
+        # Should be a no-op
+        self.assert_qmp(result, 'return', {})
+        self.assertEquals(self.vm.get_qmp_events(wait=False), [])
+
+    def test_remove_on_closed(self):
+        if self.has_opened:
+            # Empty floppy drive
+            return
+
+        result = self.vm.qmp('blockdev-remove-medium', device='drive0')
+        self.assert_qmp(result, 'error/class', 'GenericError')
+
+    def test_insert_on_closed(self):
+        if self.has_opened:
+            # Empty floppy drive
+            return
+
+        result = self.vm.qmp('blockdev-add',
+                             options={'node-name': 'new',
+                                      'driver': iotests.imgfmt,
+                                      'file': {'filename': new_img,
+                                               'driver': 'file'}})
+        self.assert_qmp(result, 'return', {})
+
+        result = self.vm.qmp('blockdev-insert-medium', device='drive0',
+                                                       node_name='new')
+        self.assert_qmp(result, 'error/class', 'GenericError')
+
+class TestInitiallyFilled(GeneralChangeTestsBaseClass):
+    was_empty = False
+
+    def setUp(self, media, interface):
+        qemu_img('create', '-f', iotests.imgfmt, old_img, '1440k')
+        qemu_img('create', '-f', iotests.imgfmt, new_img, '1440k')
+        self.vm = iotests.VM().add_drive(old_img, 'media=%s' % media, interface)
+        self.vm.launch()
+
+    def tearDown(self):
+        self.vm.shutdown()
+        os.remove(old_img)
+        os.remove(new_img)
+
+    def test_insert_on_filled(self):
+        result = self.vm.qmp('blockdev-add',
+                             options={'node-name': 'new',
+                                      'driver': iotests.imgfmt,
+                                      'file': {'filename': new_img,
+                                               'driver': 'file'}})
+        self.assert_qmp(result, 'return', {})
+
+        result = self.vm.qmp('blockdev-open-tray', device='drive0')
+        self.assert_qmp(result, 'return', {})
+
+        self.wait_for_open()
+
+        result = self.vm.qmp('blockdev-insert-medium', device='drive0',
+                                                       node_name='new')
+        self.assert_qmp(result, 'error/class', 'GenericError')
+
+class TestInitiallyEmpty(GeneralChangeTestsBaseClass):
+    was_empty = True
+
+    def setUp(self, media, interface):
+        qemu_img('create', '-f', iotests.imgfmt, new_img, '1440k')
+        self.vm = iotests.VM().add_drive(None, 'media=%s' % media, interface)
+        self.vm.launch()
+
+    def tearDown(self):
+        self.vm.shutdown()
+        os.remove(new_img)
+
+    def test_remove_on_empty(self):
+        result = self.vm.qmp('blockdev-open-tray', device='drive0')
+        self.assert_qmp(result, 'return', {})
+
+        self.wait_for_open()
+
+        result = self.vm.qmp('blockdev-remove-medium', device='drive0')
+        # Should be a no-op
+        self.assert_qmp(result, 'return', {})
+
+class TestCDInitiallyFilled(TestInitiallyFilled):
+    TestInitiallyFilled = TestInitiallyFilled
+    has_real_tray = True
+
+    def setUp(self):
+        self.TestInitiallyFilled.setUp(self, 'cdrom', 'ide')
+
+class TestCDInitiallyEmpty(TestInitiallyEmpty):
+    TestInitiallyEmpty = TestInitiallyEmpty
+    has_real_tray = True
+
+    def setUp(self):
+        self.TestInitiallyEmpty.setUp(self, 'cdrom', 'ide')
+
+class TestFloppyInitiallyFilled(TestInitiallyFilled):
+    TestInitiallyFilled = TestInitiallyFilled
+    has_real_tray = False
+
+    def setUp(self):
+        self.TestInitiallyFilled.setUp(self, 'disk', 'floppy')
+
+class TestFloppyInitiallyEmpty(TestInitiallyEmpty):
+    TestInitiallyEmpty = TestInitiallyEmpty
+    has_real_tray = False
+
+    def setUp(self):
+        self.TestInitiallyEmpty.setUp(self, 'disk', 'floppy')
+        # FDDs not having a real tray and there not being a medium inside the
+        # tray at startup means the tray will be considered open
+        self.has_opened = True
+
+class TestChangeReadOnly(ChangeBaseClass):
+    def setUp(self):
+        qemu_img('create', '-f', iotests.imgfmt, old_img, '1440k')
+        qemu_img('create', '-f', iotests.imgfmt, new_img, '1440k')
+        self.vm = iotests.VM()
+
+    def tearDown(self):
+        self.vm.shutdown()
+        os.chmod(old_img, 0666)
+        os.chmod(new_img, 0666)
+        os.remove(old_img)
+        os.remove(new_img)
+
+    def test_ro_ro_retain(self):
+        os.chmod(old_img, 0444)
+        os.chmod(new_img, 0444)
+        self.vm.add_drive(old_img, 'media=disk,read-only=on', 'floppy')
+        self.vm.launch()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', False)
+        self.assert_qmp(result, 'return[0]/inserted/ro', True)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
+
+        result = self.vm.qmp('blockdev-change-medium', device='drive0',
+                                                       filename=new_img,
+                                                       format=iotests.imgfmt,
+                                                       read_only_mode='retain')
+        self.assert_qmp(result, 'return', {})
+
+        self.wait_for_open()
+        self.wait_for_close()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', False)
+        self.assert_qmp(result, 'return[0]/inserted/ro', True)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', new_img)
+
+    def test_ro_rw_retain(self):
+        os.chmod(old_img, 0444)
+        self.vm.add_drive(old_img, 'media=disk,read-only=on', 'floppy')
+        self.vm.launch()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', False)
+        self.assert_qmp(result, 'return[0]/inserted/ro', True)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
+
+        result = self.vm.qmp('blockdev-change-medium', device='drive0',
+                                                       filename=new_img,
+                                                       format=iotests.imgfmt,
+                                                       read_only_mode='retain')
+        self.assert_qmp(result, 'return', {})
+
+        self.wait_for_open()
+        self.wait_for_close()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', False)
+        self.assert_qmp(result, 'return[0]/inserted/ro', True)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', new_img)
+
+    def test_rw_ro_retain(self):
+        os.chmod(new_img, 0444)
+        self.vm.add_drive(old_img, 'media=disk', 'floppy')
+        self.vm.launch()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', False)
+        self.assert_qmp(result, 'return[0]/inserted/ro', False)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
+
+        result = self.vm.qmp('blockdev-change-medium', device='drive0',
+                                                       filename=new_img,
+                                                       format=iotests.imgfmt,
+                                                       read_only_mode='retain')
+        self.assert_qmp(result, 'error/class', 'GenericError')
+
+        self.assertEquals(self.vm.get_qmp_events(wait=False), [])
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', False)
+        self.assert_qmp(result, 'return[0]/inserted/ro', False)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
+
+    def test_ro_rw(self):
+        os.chmod(old_img, 0444)
+        self.vm.add_drive(old_img, 'media=disk,read-only=on', 'floppy')
+        self.vm.launch()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', False)
+        self.assert_qmp(result, 'return[0]/inserted/ro', True)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
+
+        result = self.vm.qmp('blockdev-change-medium',
+                             device='drive0',
+                             filename=new_img,
+                             format=iotests.imgfmt,
+                             read_only_mode='read-write')
+        self.assert_qmp(result, 'return', {})
+
+        self.wait_for_open()
+        self.wait_for_close()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', False)
+        self.assert_qmp(result, 'return[0]/inserted/ro', False)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', new_img)
+
+    def test_rw_ro(self):
+        os.chmod(new_img, 0444)
+        self.vm.add_drive(old_img, 'media=disk', 'floppy')
+        self.vm.launch()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', False)
+        self.assert_qmp(result, 'return[0]/inserted/ro', False)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
+
+        result = self.vm.qmp('blockdev-change-medium',
+                             device='drive0',
+                             filename=new_img,
+                             format=iotests.imgfmt,
+                             read_only_mode='read-only')
+        self.assert_qmp(result, 'return', {})
+
+        self.wait_for_open()
+        self.wait_for_close()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', False)
+        self.assert_qmp(result, 'return[0]/inserted/ro', True)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', new_img)
+
+    def test_make_rw_ro(self):
+        self.vm.add_drive(old_img, 'media=disk', 'floppy')
+        self.vm.launch()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', False)
+        self.assert_qmp(result, 'return[0]/inserted/ro', False)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
+
+        result = self.vm.qmp('blockdev-change-medium',
+                             device='drive0',
+                             filename=new_img,
+                             format=iotests.imgfmt,
+                             read_only_mode='read-only')
+        self.assert_qmp(result, 'return', {})
+
+        self.wait_for_open()
+        self.wait_for_close()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', False)
+        self.assert_qmp(result, 'return[0]/inserted/ro', True)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', new_img)
+
+    def test_make_ro_rw(self):
+        os.chmod(new_img, 0444)
+        self.vm.add_drive(old_img, 'media=disk', 'floppy')
+        self.vm.launch()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', False)
+        self.assert_qmp(result, 'return[0]/inserted/ro', False)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
+
+        result = self.vm.qmp('blockdev-change-medium',
+                             device='drive0',
+                             filename=new_img,
+                             format=iotests.imgfmt,
+                             read_only_mode='read-write')
+        self.assert_qmp(result, 'error/class', 'GenericError')
+
+        self.assertEquals(self.vm.get_qmp_events(wait=False), [])
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', False)
+        self.assert_qmp(result, 'return[0]/inserted/ro', False)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
+
+    def test_make_rw_ro_by_retain(self):
+        os.chmod(old_img, 0444)
+        self.vm.add_drive(old_img, 'media=disk,read-only=on', 'floppy')
+        self.vm.launch()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', False)
+        self.assert_qmp(result, 'return[0]/inserted/ro', True)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
+
+        result = self.vm.qmp('blockdev-change-medium', device='drive0',
+                                                       filename=new_img,
+                                                       format=iotests.imgfmt,
+                                                       read_only_mode='retain')
+        self.assert_qmp(result, 'return', {})
+
+        self.wait_for_open()
+        self.wait_for_close()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', False)
+        self.assert_qmp(result, 'return[0]/inserted/ro', True)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', new_img)
+
+    def test_make_ro_rw_by_retain(self):
+        os.chmod(new_img, 0444)
+        self.vm.add_drive(old_img, 'media=disk', 'floppy')
+        self.vm.launch()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', False)
+        self.assert_qmp(result, 'return[0]/inserted/ro', False)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
+
+        result = self.vm.qmp('blockdev-change-medium', device='drive0',
+                                                       filename=new_img,
+                                                       format=iotests.imgfmt,
+                                                       read_only_mode='retain')
+        self.assert_qmp(result, 'error/class', 'GenericError')
+
+        self.assertEquals(self.vm.get_qmp_events(wait=False), [])
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', False)
+        self.assert_qmp(result, 'return[0]/inserted/ro', False)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
+
+    def test_rw_ro_cycle(self):
+        os.chmod(new_img, 0444)
+        self.vm.add_drive(old_img, 'media=disk', 'floppy')
+        self.vm.launch()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', False)
+        self.assert_qmp(result, 'return[0]/inserted/ro', False)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
+
+        result = self.vm.qmp('blockdev-add',
+                             options={'node-name': 'new',
+                                      'driver': iotests.imgfmt,
+                                      'read-only': True,
+                                      'file': {'filename': new_img,
+                                               'driver': 'file'}})
+        self.assert_qmp(result, 'return', {})
+
+        result = self.vm.qmp('blockdev-open-tray', device='drive0', force=True)
+        self.assert_qmp(result, 'return', {})
+
+        self.wait_for_open()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', True)
+        self.assert_qmp(result, 'return[0]/inserted/ro', False)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
+
+        result = self.vm.qmp('blockdev-remove-medium', device='drive0')
+        self.assert_qmp(result, 'return', {})
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', True)
+        self.assert_qmp_absent(result, 'return[0]/inserted')
+
+        result = self.vm.qmp('blockdev-insert-medium', device='drive0',
+                                                       node_name='new')
+        self.assert_qmp(result, 'return', {})
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', True)
+        self.assert_qmp(result, 'return[0]/inserted/ro', True)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', new_img)
+
+        result = self.vm.qmp('blockdev-close-tray', device='drive0')
+        self.assert_qmp(result, 'return', {})
+
+        self.wait_for_close()
+
+        result = self.vm.qmp('query-block')
+        self.assert_qmp(result, 'return[0]/tray_open', False)
+        self.assert_qmp(result, 'return[0]/inserted/ro', True)
+        self.assert_qmp(result, 'return[0]/inserted/image/filename', new_img)
+
+GeneralChangeTestsBaseClass = None
+TestInitiallyFilled = None
+TestInitiallyEmpty = None
+
+if __name__ == '__main__':
+    iotests.main()
diff --git a/tests/qemu-iotests/118.out b/tests/qemu-iotests/118.out
new file mode 100644
index 0000000..7d4a8ca
--- /dev/null
+++ b/tests/qemu-iotests/118.out
@@ -0,0 +1,5 @@
+..........................................................
+----------------------------------------------------------------------
+Ran 58 tests
+
+OK
diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
index 439b1d2..85329af 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -121,6 +121,7 @@
 114 rw auto quick
 115 rw auto
 116 rw auto quick
+118 rw auto
 119 rw auto quick
 120 rw auto quick
 121 rw auto
-- 
2.5.2

Re: [Qemu-devel] [PATCH v5 01/38] block: Remove host floppy support

[Eric Blake]

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On 09/18/2015 09:22 AM, Max Reitz wrote:
> It has been deprecated as of 2.3, so we can now remove it.
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> ---
>  block/raw-posix.c    | 222 ++-------------------------------------------------
>  qapi/block-core.json |   9 +--
>  2 files changed, 9 insertions(+), 222 deletions(-)

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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Re: [Qemu-devel] [PATCH v5 02/38] block: Set BDRV_O_INCOMING in bdrv_fill_options()

[Eric Blake]

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On 09/18/2015 09:22 AM, Max Reitz wrote:
> This flag should not be set for the root BDS only, but for any BDS that
> is being created while incoming migration is pending, so setting it is
> moved from blockdev_init() to bdrv_fill_options().
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> ---
>  block.c    | 4 ++++
>  blockdev.c | 4 ----
>  2 files changed, 4 insertions(+), 4 deletions(-)

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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Re: [Qemu-devel] [PATCH v5 03/38] blockdev: Allow creation of BDS trees without BB

[Eric Blake]

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On 09/18/2015 09:22 AM, Max Reitz wrote:
> If the "id" field is missing from the options given to blockdev-add,
> just omit the BlockBackend and create the BlockDriverState tree alone.
> 
> However, if "id" is missing, "node-name" must be specified; otherwise,
> the BDS tree would no longer be accessible.
> 
> Many BDS options which are not parsed by bdrv_open() (like caching)
> cannot be specified for these BB-less BDS trees yet. A future patch will
> remove this limitation.
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> ---
>  blockdev.c                 | 44 +++++++++++++++++++++++++++++++-------------
>  qapi/block-core.json       | 13 +++++++++----
>  tests/qemu-iotests/087     |  2 +-
>  tests/qemu-iotests/087.out |  4 ++--
>  4 files changed, 43 insertions(+), 20 deletions(-)
> 

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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Re: [Qemu-devel] [PATCH v5 04/38] iotests: Only create BB if necessary

[Eric Blake]

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On 09/18/2015 09:22 AM, Max Reitz wrote:
> Tests 071 and 081 test giving references in blockdev-add. It is not
> necessary to create a BlockBackend here, so omit it.
> 
> While at it, fix up some blockdev-add invocations in the vicinity
> (s/raw/$IMGFMT/ in 081, drop the format BDS for blkverify's raw child in
> 071).
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> ---
>  tests/qemu-iotests/071     | 54 ++++++++++++++++++++++++++++++++++++++--------
>  tests/qemu-iotests/071.out | 12 +++++++----
>  tests/qemu-iotests/081     | 18 +++++++++++++---
>  tests/qemu-iotests/081.out |  5 +++--
>  4 files changed, 71 insertions(+), 18 deletions(-)
> 

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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Re: [Qemu-devel] [PATCH v5 07/38] block: Make bdrv_is_inserted() recursive

[Eric Blake]

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On 09/18/2015 09:22 AM, Max Reitz wrote:
> If bdrv_is_inserted() is called on the top level BDS, it should make
> sure all nodes in the BDS tree are actually inserted.
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> ---
>  block.c | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
> 

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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Re: [Qemu-devel] [PATCH v5 08/38] block/raw_bsd: Drop raw_is_inserted()

[Eric Blake]

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On 09/18/2015 09:22 AM, Max Reitz wrote:
> With the new automatically-recursive implementation of
> bdrv_is_inserted() checking by default whether all the children of a BDS
> are inserted, we can drop raw's own implementation.
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> ---
>  block/raw_bsd.c | 6 ------
>  1 file changed, 6 deletions(-)
> 

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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Re: [Qemu-devel] [PATCH v5 09/38] block: Invoke change media CB before NULLing drv

[Eric Blake]

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On 09/18/2015 09:22 AM, Max Reitz wrote:
> In order to handle host device passthrough, some guest device models
> may call blk_is_inserted() to check whether the medium is inserted on
> the host, when checking the guest tray status.
> 
> This tray status is inquired by blk_dev_change_media_cb(); because
> bdrv_is_inserted() (invoked by blk_is_inserted()) always returns 0 for

Stale comment - you just fixed bdrv_is_inserted() to return false rather
than 0 in commit 5/38.

> BDS with drv set to NULL, blk_dev_change_media_cb() should therefore be
> called before drv is set to NULL.
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> Reviewed-by: Eric Blake <eblake@redhat.com>
> Reviewed-by: Alberto Garcia <berto@igalia.com>
> ---
>  block.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)

R-b still stands.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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Re: [Qemu-devel] [PATCH v5 10/38] hw/block/fdc: Implement tray status

[Eric Blake]

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On 09/18/2015 09:22 AM, Max Reitz wrote:
> The tray of an FDD is open iff there is no medium inserted (there are
> only two states for an FDD: "medium inserted" or "no medium inserted").
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> ---
>  hw/block/fdc.c   | 20 ++++++++++++++++----
>  tests/fdc-test.c |  4 +---
>  2 files changed, 17 insertions(+), 7 deletions(-)
> 

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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Re: [Qemu-devel] [PATCH v5 14/38] block: Remove wr_highest_sector from BlockAcctStats

[Eric Blake]

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On 09/18/2015 09:22 AM, Max Reitz wrote:
> BlockAcctStats contains statistics about the data transferred from and
> to the device; wr_highest_sector does not fit in with the rest.
> 
> Furthermore, those statistics are supposed to be specific for a certain
> device and not necessarily for a BDS (see the comment above
> bdrv_get_stats()); on the other hand, wr_highest_sector may be a rather
> important information to know for each BDS. When BlockAcctStats is
> finally removed from the BDS, we will want to keep wr_highest_sector in
> the BDS.
> 
> Finally, wr_highest_sector is renamed to wr_highest_offset and given the
> appropriate meaning. Externally, it is represented as an offset so there
> is no point in doing something different internally. Its definition is
> changed to match that in qapi/block-core.json which is "the offset after
> the greatest byte written to". Doing so should not cause any harm since
> if external programs tried to calculate the volume usage by
> (wr_highest_offset + 512) / volume_size, after this patch they will just
> assume the volume to be full slightly earlier than before.
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> Reviewed-by: Eric Blake <eblake@redhat.com>
> Reviewed-by: Alberto Garcia <berto@igalia.com>

Still holds, but...

> +++ b/qmp-commands.hx
> @@ -2481,8 +2481,8 @@ Each json-object contain the following:
>      - "wr_total_time_ns": total time spend on writes in nano-seconds (json-int)
>      - "rd_total_time_ns": total time spend on reads in nano-seconds (json-int)
>      - "flush_total_time_ns": total time spend on cache flushes in nano-seconds (json-int)
> -    - "wr_highest_offset": Highest offset of a sector written since the
> -                           BlockDriverState has been opened (json-int)
> +    - "wr_highest_offset": The offset after the greatest byte written to the
> +                           BlockDriverState since it has been opened (json-int)

...someday, I'd really like to have this stat show as non-zero even when
first opening the device (before writing to it). Right now, you have no
clue how full a backing device is prior to starting a block-commit; you
have to start writing to it to get a feel for its current usage.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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Re: [Qemu-devel] [PATCH v5 22/38] block: Prepare for NULL BDS

[Eric Blake]

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On 09/18/2015 09:22 AM, Max Reitz wrote:
> blk_bs() will not necessarily return a non-NULL value any more (unless
> blk_is_available() is true or it can be assumed to otherwise, e.g.
> because it is called immediately after a successful blk_new_with_bs() or
> blk_new_open()).
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> ---
>  block.c             |   5 ++
>  block/qapi.c        |   4 +-
>  blockdev.c          | 201 ++++++++++++++++++++++++++++++++++------------------
>  hw/block/xen_disk.c |   4 +-
>  migration/block.c   |   5 ++
>  monitor.c           |   4 ++
>  6 files changed, 153 insertions(+), 70 deletions(-)
> 

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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Re: [Qemu-devel] [PATCH v5 14/38] block: Remove wr_highest_sector from BlockAcctStats

[Kevin Wolf]

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Am 18.09.2015 um 18:59 hat Eric Blake geschrieben:
> On 09/18/2015 09:22 AM, Max Reitz wrote:
> > BlockAcctStats contains statistics about the data transferred from and
> > to the device; wr_highest_sector does not fit in with the rest.
> > 
> > Furthermore, those statistics are supposed to be specific for a certain
> > device and not necessarily for a BDS (see the comment above
> > bdrv_get_stats()); on the other hand, wr_highest_sector may be a rather
> > important information to know for each BDS. When BlockAcctStats is
> > finally removed from the BDS, we will want to keep wr_highest_sector in
> > the BDS.
> > 
> > Finally, wr_highest_sector is renamed to wr_highest_offset and given the
> > appropriate meaning. Externally, it is represented as an offset so there
> > is no point in doing something different internally. Its definition is
> > changed to match that in qapi/block-core.json which is "the offset after
> > the greatest byte written to". Doing so should not cause any harm since
> > if external programs tried to calculate the volume usage by
> > (wr_highest_offset + 512) / volume_size, after this patch they will just
> > assume the volume to be full slightly earlier than before.
> > 
> > Signed-off-by: Max Reitz <mreitz@redhat.com>
> > Reviewed-by: Eric Blake <eblake@redhat.com>
> > Reviewed-by: Alberto Garcia <berto@igalia.com>
> 
> Still holds, but...
> 
> > +++ b/qmp-commands.hx
> > @@ -2481,8 +2481,8 @@ Each json-object contain the following:
> >      - "wr_total_time_ns": total time spend on writes in nano-seconds (json-int)
> >      - "rd_total_time_ns": total time spend on reads in nano-seconds (json-int)
> >      - "flush_total_time_ns": total time spend on cache flushes in nano-seconds (json-int)
> > -    - "wr_highest_offset": Highest offset of a sector written since the
> > -                           BlockDriverState has been opened (json-int)
> > +    - "wr_highest_offset": The offset after the greatest byte written to the
> > +                           BlockDriverState since it has been opened (json-int)
> 
> ...someday, I'd really like to have this stat show as non-zero even when
> first opening the device (before writing to it). Right now, you have no
> clue how full a backing device is prior to starting a block-commit; you
> have to start writing to it to get a feel for its current usage.

With which value would it start? You don't want the file/device size
because for block devices that's more than is actually used yet.

What you really want to know is a number for the parent node, which
isn't readily available for qcow2 (you would have to scan the refcounts
in the last refcount block on startup) and doesn't really exist for most
other formats (very few of them can be used on block devices, most rely
on the file size).

Kevin

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Re: [Qemu-devel] [PATCH v5 14/38] block: Remove wr_highest_sector from BlockAcctStats

[Eric Blake]

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On 09/21/2015 01:57 AM, Kevin Wolf wrote:

>>> +    - "wr_highest_offset": The offset after the greatest byte written to the
>>> +                           BlockDriverState since it has been opened (json-int)
>>
>> ...someday, I'd really like to have this stat show as non-zero even when
>> first opening the device (before writing to it). Right now, you have no
>> clue how full a backing device is prior to starting a block-commit; you
>> have to start writing to it to get a feel for its current usage.
> 
> With which value would it start? You don't want the file/device size
> because for block devices that's more than is actually used yet.
> 
> What you really want to know is a number for the parent node, which
> isn't readily available for qcow2 (you would have to scan the refcounts
> in the last refcount block on startup) and doesn't really exist for most
> other formats (very few of them can be used on block devices, most rely
> on the file size).

Libvirt only uses the stat on qcow2 format atop block devices, and uses
it precisely because that is the one place where relying on device size
is wrong.  And yes, it really WOULD be nice for the value to read the
last refcount block on startup, as that IS the correct value.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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Re: [Qemu-devel] [PATCH v5 17/38] block: Add BlockBackendRootState

[Kevin Wolf]

Am 18.09.2015 um 17:22 hat Max Reitz geschrieben:
> This structure will store some of the state of the root BDS if the BDS
> tree is removed, so that state can be restored once a new BDS tree is
> inserted.

This is magic that is bound to bite us sooner or later. I see that we
have to do this in order to maintain compatibility, but imagine we'll
have multiple BlockBackends sitting on top of the same BDS. They'll be
fighting for whose throttling settings are applied. With this approach,
the winner is the BlockBackend that most recently went from no medium to
medium, which might just be the most surprising way to solve the
problem.

I'll detail one aspect of the problem below.

The correct way to solve this seems to be that each BB has its own I/O
throttling filter. Actually, if we could lift the throttling code to
BlockBackend, that might solve the problem.

I guess the same applies for the other fields in BlockBackendRootState.

> Signed-off-by: Max Reitz <mreitz@redhat.com>
> Reviewed-by: Eric Blake <eblake@redhat.com>
> ---
>  block/block-backend.c          | 37 +++++++++++++++++++++++++++++++++++++
>  include/block/block_int.h      | 10 ++++++++++
>  include/qemu/typedefs.h        |  1 +
>  include/sysemu/block-backend.h |  2 ++
>  4 files changed, 50 insertions(+)
> 
> diff --git a/block/block-backend.c b/block/block-backend.c
> index 1f2cd9b..9590be5 100644
> --- a/block/block-backend.c
> +++ b/block/block-backend.c
> @@ -13,6 +13,7 @@
>  #include "sysemu/block-backend.h"
>  #include "block/block_int.h"
>  #include "block/blockjob.h"
> +#include "block/throttle-groups.h"
>  #include "sysemu/blockdev.h"
>  #include "sysemu/sysemu.h"
>  #include "qapi-event.h"
> @@ -37,6 +38,10 @@ struct BlockBackend {
>      /* the block size for which the guest device expects atomicity */
>      int guest_block_size;
>  
> +    /* If the BDS tree is removed, some of its options are stored here (which
> +     * can be used to restore those options in the new BDS on insert) */
> +    BlockBackendRootState root_state;
> +
>      /* I/O stats (display with "info blockstats"). */
>      BlockAcctStats stats;
>  
> @@ -161,6 +166,7 @@ static void blk_delete(BlockBackend *blk)
>          bdrv_unref(blk->bs);
>          blk->bs = NULL;
>      }
> +    g_free(blk->root_state.throttle_group_name);
>      /* Avoid double-remove after blk_hide_on_behalf_of_hmp_drive_del() */
>      if (blk->name[0]) {
>          QTAILQ_REMOVE(&blk_backends, blk, link);
> @@ -1050,3 +1056,34 @@ int blk_probe_geometry(BlockBackend *blk, HDGeometry *geo)
>  {
>      return bdrv_probe_geometry(blk->bs, geo);
>  }
> +
> +/*
> + * Updates the BlockBackendRootState object with data from the currently
> + * attached BlockDriverState.
> + */
> +void blk_update_root_state(BlockBackend *blk)
> +{
> +    assert(blk->bs);
> +
> +    blk->root_state.open_flags    = blk->bs->open_flags;
> +    blk->root_state.read_only     = blk->bs->read_only;
> +    blk->root_state.detect_zeroes = blk->bs->detect_zeroes;
> +
> +    blk->root_state.io_limits_enabled = blk->bs->io_limits_enabled;
> +
> +    g_free(blk->root_state.throttle_group_name);
> +    if (blk->bs->throttle_state) {
> +        throttle_get_config(blk->bs->throttle_state,
> +                            &blk->root_state.throttle_config);
> +        blk->root_state.throttle_group_name =
> +            g_strdup(throttle_group_get_name(blk->bs));

The throttling group name is essentially a weak reference. I think
making it strong is worth considering.

If you attach a new BDS, if the old throttling group still exists, the
new BDS is re-added there, as expected. If the throttling group has got
changed limits meanwhile, you need to choose whether to apply the limits
saved here or use the new limits for the BDS. I guess the latter will be
the correct choice.

If the old throttling group doesn't exist any more, a new one is created
with the old name and limits. If two BlockBackends eject their media at
separate times and the throttle group goes away, reinstantiating the
throttle group by attaching a BDS to both BBs will use the config of the
BB that got a new medium first (as opposed to: the latest setting the
throttling group had before it was freed).

If the old throttling group was freed, but then a new throttling group
was created with the same name, we get attached to that new group with
its new limits. This could be slightly surprising as well.

Kevin

Re: [Qemu-devel] [PATCH v5 19/38] block: Fail requests to empty BlockBackend

[Kevin Wolf]

Am 18.09.2015 um 17:22 hat Max Reitz geschrieben:
> If there is no BlockDriverState in a BlockBackend or if the tray of the
> guest device is open, fail all requests (where that is possible) with
> -ENOMEDIUM.
> 
> The reason the status of the guest device is taken into account is
> because once the guest device's tray is opened, any request on the same
> BlockBackend as the guest uses should fail. If the BDS tree is supposed
> to be usable even after ejecting it from the guest, a different
> BlockBackend must be used.
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> Reviewed-by: Eric Blake <eblake@redhat.com>

Do we want to include blk_drain() to make it a no-op instead of
crashing?

Also, we're now introducing BlockAIOCBs with a NULL bs with your use of
abort_aio_request. I haven't carefully reviewed the implications of this
yet, but that should definitely be done before we merge the series.

Kevin

Re: [Qemu-devel] [PATCH v5 20/38] block: Prepare remaining BB functions for NULL BDS

[Kevin Wolf]

Am 18.09.2015 um 17:22 hat Max Reitz geschrieben:
> There are several BlockBackend functions which, in theory, cannot fail.
> This patch makes them cope with the BlockDriverState pointer being NULL
> by making them fall back to some default action like ignoring the value
> in setters and returning the default in getters.
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> Reviewed-by: Eric Blake <eblake@redhat.com>

Hm, okay, maybe bdrv_drain() belongs here. I just reviewed the end
result for completeness and didn't check which patch did what.

>  int blk_enable_write_cache(BlockBackend *blk)
>  {
> +    if (!blk->bs) {
> +        return 0;
> +    }
> +
>      return bdrv_enable_write_cache(blk->bs);
>  }
>  
>  void blk_set_enable_write_cache(BlockBackend *blk, bool wce)
>  {
> -    bdrv_set_enable_write_cache(blk->bs, wce);
> +    if (blk->bs) {
> +        bdrv_set_enable_write_cache(blk->bs, wce);
> +    }
>  }

WCE is part of the open_flags in BlockBackendRootState. The root state
doesn't seem to be used yet, and I wrote about my concerns about it in
reply to an earlier patch, but as long as we have it, should this
query/modify the root state if no BDS is attached?

Kevin

Re: [Qemu-devel] [PATCH v5 21/38] block: Add blk_insert_bs()

[Kevin Wolf]

Am 18.09.2015 um 17:22 hat Max Reitz geschrieben:
> This function associates the given BlockDriverState with the given
> BlockBackend.
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> Reviewed-by: Eric Blake <eblake@redhat.com>
> Reviewed-by: Alberto Garcia <berto@igalia.com>
> ---
>  block/block-backend.c          | 16 ++++++++++++++++
>  include/sysemu/block-backend.h |  1 +
>  2 files changed, 17 insertions(+)
> 
> diff --git a/block/block-backend.c b/block/block-backend.c
> index 33145f8..652385e 100644
> --- a/block/block-backend.c
> +++ b/block/block-backend.c
> @@ -314,6 +314,22 @@ void blk_hide_on_behalf_of_hmp_drive_del(BlockBackend *blk)
>  }
>  
>  /*
> + * Associates a new BlockDriverState with @blk.
> + */
> +void blk_insert_bs(BlockBackend *blk, BlockDriverState *bs)
> +{
> +    if (bs->blk == blk) {
> +        return;
> +    }
> +
> +    assert(!blk->bs);
> +    assert(!bs->blk);

Why is it useful to allow reconnecting a BDS to a BB it's already
connected to? I would have expected that we can assert that this is not
the case.

> +    bdrv_ref(bs);
> +    blk->bs = bs;
> +    bs->blk = blk;
> +}

My series to remove bdrv_swap() introduces a blk_set_bs() function,
which looks suspiciously similar to this one, except that it allows
passing a BB that already had a BDS (it gets unrefed then) and that I
don't assert that the BDS isn't attached to a BB yet (I should do that).

Do you think that's similar enough to have only one function?

Kevin

Re: [Qemu-devel] [PATCH v5 00/38] blockdev: BlockBackend and media

[Kevin Wolf]

Am 18.09.2015 um 17:22 hat Max Reitz geschrieben:
> This series reworks a lot regarding BlockBackend and media. Basically,
> it allows empty BlockBackends, that is BBs without a BDS tree.
> 
> Before this series, empty drives are represented by a BlockBackend with
> an empty BDS attached to it (a BDS with a NULL driver). However, now we
> have BlockBackends, thus an empty drive should be represented by a
> BlockBackend without any BDS tree attached to it. This is what this
> series does.

Patches 1-16 and 18: Reviewed-by: Kevin Wolf <kwolf@redhat.com>

I had comments for 17 and 19-21, and can't seem to find a base commit
that patch 22 applies cleanly to, so I'm stopping the review here,
waiting for another rebase or instructions how to apply the series.

Kevin

Re: [Qemu-devel] [PATCH v5 17/38] block: Add BlockBackendRootState

[Max Reitz]

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On 22.09.2015 16:17, Kevin Wolf wrote:
> Am 18.09.2015 um 17:22 hat Max Reitz geschrieben:
>> This structure will store some of the state of the root BDS if the BDS
>> tree is removed, so that state can be restored once a new BDS tree is
>> inserted.
> 
> This is magic that is bound to bite us sooner or later. I see that we
> have to do this in order to maintain compatibility, but imagine we'll
> have multiple BlockBackends sitting on top of the same BDS. They'll be
> fighting for whose throttling settings are applied. With this approach,
> the winner is the BlockBackend that most recently went from no medium to
> medium, which might just be the most surprising way to solve the
> problem.

Well, my first answer to this is that as far as I remember and as far as
I can see right now, it's only qmp_blockdev_change_medium() that
accesses this structure. This is effectively a legacy command, even
though it is introduced by this series.

When using the "atomic" operations, this structure will not be used.

So let's examine what cases of multiple BBs on top of the same BDS we
can have, that are relevant here: One of the BBs always has to be the BB
belonging to a device such as a CD drive, otherwise we cannot invoke the
change command. The other BB(s) can be either:
(1) Also BBs belonging to CDD-like devices (let's call them "tray
    devices")
(2) Other BBs such as block job BBs or NBD BBs

In the first case, the scenario you described can indeed occur, but only
if the user is indeed using the change command. I'm very much inclined
to say it's the user's own fault for having multiple tray device BBs on
top of a single BDS and managing them with the change command. In any
case, with the current state of having throttling at the BDS level, we
are guarenteed to break something, at least.

In the second case, throttling will change for all the attached BBs
whenever the BDS is inserted into a throttled tray device. This seems
correct to me, at least as long as we have throttling on the BDS level.

> I'll detail one aspect of the problem below.
> 
> The correct way to solve this seems to be that each BB has its own I/O
> throttling filter. Actually, if we could lift the throttling code to
> BlockBackend, that might solve the problem.

So yes, as long as we have throttling on the BDS level, something may
always break when having multiple BBs per BDS, because you'd probably
want throttling to be on the BB level. But lifting that doesn't seem a
trivial task, and I don't really know whether I want this in this series.

Especially considering that right now you cannot have multiple BBs per BDS.

All in all: Yes, before we allow multiple BBs per BDS we want throttling
to be on the BB level. But this is nothing that should be done in or for
this series, since right now we do not allow multiple BBs per BDS.

> I guess the same applies for the other fields in BlockBackendRootState.
> 
>> Signed-off-by: Max Reitz <mreitz@redhat.com>
>> Reviewed-by: Eric Blake <eblake@redhat.com>
>> ---
>>  block/block-backend.c          | 37 +++++++++++++++++++++++++++++++++++++
>>  include/block/block_int.h      | 10 ++++++++++
>>  include/qemu/typedefs.h        |  1 +
>>  include/sysemu/block-backend.h |  2 ++
>>  4 files changed, 50 insertions(+)
>>
>> diff --git a/block/block-backend.c b/block/block-backend.c
>> index 1f2cd9b..9590be5 100644
>> --- a/block/block-backend.c
>> +++ b/block/block-backend.c
>> @@ -13,6 +13,7 @@
>>  #include "sysemu/block-backend.h"
>>  #include "block/block_int.h"
>>  #include "block/blockjob.h"
>> +#include "block/throttle-groups.h"
>>  #include "sysemu/blockdev.h"
>>  #include "sysemu/sysemu.h"
>>  #include "qapi-event.h"
>> @@ -37,6 +38,10 @@ struct BlockBackend {
>>      /* the block size for which the guest device expects atomicity */
>>      int guest_block_size;
>>  
>> +    /* If the BDS tree is removed, some of its options are stored here (which
>> +     * can be used to restore those options in the new BDS on insert) */
>> +    BlockBackendRootState root_state;
>> +
>>      /* I/O stats (display with "info blockstats"). */
>>      BlockAcctStats stats;
>>  
>> @@ -161,6 +166,7 @@ static void blk_delete(BlockBackend *blk)
>>          bdrv_unref(blk->bs);
>>          blk->bs = NULL;
>>      }
>> +    g_free(blk->root_state.throttle_group_name);
>>      /* Avoid double-remove after blk_hide_on_behalf_of_hmp_drive_del() */
>>      if (blk->name[0]) {
>>          QTAILQ_REMOVE(&blk_backends, blk, link);
>> @@ -1050,3 +1056,34 @@ int blk_probe_geometry(BlockBackend *blk, HDGeometry *geo)
>>  {
>>      return bdrv_probe_geometry(blk->bs, geo);
>>  }
>> +
>> +/*
>> + * Updates the BlockBackendRootState object with data from the currently
>> + * attached BlockDriverState.
>> + */
>> +void blk_update_root_state(BlockBackend *blk)
>> +{
>> +    assert(blk->bs);
>> +
>> +    blk->root_state.open_flags    = blk->bs->open_flags;
>> +    blk->root_state.read_only     = blk->bs->read_only;
>> +    blk->root_state.detect_zeroes = blk->bs->detect_zeroes;
>> +
>> +    blk->root_state.io_limits_enabled = blk->bs->io_limits_enabled;
>> +
>> +    g_free(blk->root_state.throttle_group_name);
>> +    if (blk->bs->throttle_state) {
>> +        throttle_get_config(blk->bs->throttle_state,
>> +                            &blk->root_state.throttle_config);
>> +        blk->root_state.throttle_group_name =
>> +            g_strdup(throttle_group_get_name(blk->bs));
> 
> The throttling group name is essentially a weak reference. I think
> making it strong is worth considering.
> 
> If you attach a new BDS, if the old throttling group still exists, the
> new BDS is re-added there, as expected. If the throttling group has got
> changed limits meanwhile, you need to choose whether to apply the limits
> saved here or use the new limits for the BDS. I guess the latter will be
> the correct choice.
> 
> If the old throttling group doesn't exist any more, a new one is created
> with the old name and limits. If two BlockBackends eject their media at
> separate times and the throttle group goes away, reinstantiating the
> throttle group by attaching a BDS to both BBs will use the config of the
> BB that got a new medium first (as opposed to: the latest setting the
> throttling group had before it was freed).
> 
> If the old throttling group was freed, but then a new throttling group
> was created with the same name, we get attached to that new group with
> its new limits. This could be slightly surprising as well.

Yes, I'll see to making it a strong reference, and to fetching the
throttle config from the throttle group (probably by using
throttle_group_unregister_bs()+throttle_group_register_bs()
consecutively in qmp_blockdev_change_medium(), and dropping
BBRS.throttle_config).

Max


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Re: [Qemu-devel] [PATCH v5 19/38] block: Fail requests to empty BlockBackend

[Max Reitz]

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On 22.09.2015 16:30, Kevin Wolf wrote:
> Am 18.09.2015 um 17:22 hat Max Reitz geschrieben:
>> If there is no BlockDriverState in a BlockBackend or if the tray of the
>> guest device is open, fail all requests (where that is possible) with
>> -ENOMEDIUM.
>>
>> The reason the status of the guest device is taken into account is
>> because once the guest device's tray is opened, any request on the same
>> BlockBackend as the guest uses should fail. If the BDS tree is supposed
>> to be usable even after ejecting it from the guest, a different
>> BlockBackend must be used.
>>
>> Signed-off-by: Max Reitz <mreitz@redhat.com>
>> Reviewed-by: Eric Blake <eblake@redhat.com>
> 
> Do we want to include blk_drain() to make it a no-op instead of
> crashing?

Yes, we do, so that would be in patch 20. Thanks for catching that.

> Also, we're now introducing BlockAIOCBs with a NULL bs with your use of
> abort_aio_request. I haven't carefully reviewed the implications of this
> yet, but that should definitely be done before we merge the series.

That should be patch 12.

Max



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Re: [Qemu-devel] [PATCH v5 20/38] block: Prepare remaining BB functions for NULL BDS

[Max Reitz]

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On 22.09.2015 16:35, Kevin Wolf wrote:
> Am 18.09.2015 um 17:22 hat Max Reitz geschrieben:
>> There are several BlockBackend functions which, in theory, cannot fail.
>> This patch makes them cope with the BlockDriverState pointer being NULL
>> by making them fall back to some default action like ignoring the value
>> in setters and returning the default in getters.
>>
>> Signed-off-by: Max Reitz <mreitz@redhat.com>
>> Reviewed-by: Eric Blake <eblake@redhat.com>
> 
> Hm, okay, maybe bdrv_drain() belongs here. I just reviewed the end
> result for completeness and didn't check which patch did what.
> 
>>  int blk_enable_write_cache(BlockBackend *blk)
>>  {
>> +    if (!blk->bs) {
>> +        return 0;
>> +    }
>> +
>>      return bdrv_enable_write_cache(blk->bs);
>>  }
>>  
>>  void blk_set_enable_write_cache(BlockBackend *blk, bool wce)
>>  {
>> -    bdrv_set_enable_write_cache(blk->bs, wce);
>> +    if (blk->bs) {
>> +        bdrv_set_enable_write_cache(blk->bs, wce);
>> +    }
>>  }
> 
> WCE is part of the open_flags in BlockBackendRootState. The root state
> doesn't seem to be used yet, and I wrote about my concerns about it in
> reply to an earlier patch, but as long as we have it, should this
> query/modify the root state if no BDS is attached?

Seems very reasonable, will do.

Max


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Re: [Qemu-devel] [PATCH v5 00/38] blockdev: BlockBackend and media

[Max Reitz]

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On 22.09.2015 16:45, Kevin Wolf wrote:
> Am 18.09.2015 um 17:22 hat Max Reitz geschrieben:
>> This series reworks a lot regarding BlockBackend and media. Basically,
>> it allows empty BlockBackends, that is BBs without a BDS tree.
>>
>> Before this series, empty drives are represented by a BlockBackend with
>> an empty BDS attached to it (a BDS with a NULL driver). However, now we
>> have BlockBackends, thus an empty drive should be represented by a
>> BlockBackend without any BDS tree attached to it. This is what this
>> series does.
> 
> Patches 1-16 and 18: Reviewed-by: Kevin Wolf <kwolf@redhat.com>
> 
> I had comments for 17 and 19-21, and can't seem to find a base commit
> that patch 22 applies cleanly to, so I'm stopping the review here,
> waiting for another rebase or instructions how to apply the series.

16a1b6e97c2a2919fd296db4bea2f9da2ad3cc4d was my base, if that was the
question. ;-)

Thanks for reviewing!

Max


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Re: [Qemu-devel] [PATCH v5 19/38] block: Fail requests to empty BlockBackend

[Kevin Wolf]

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Am 22.09.2015 um 17:05 hat Max Reitz geschrieben:
> On 22.09.2015 16:30, Kevin Wolf wrote:
> > Am 18.09.2015 um 17:22 hat Max Reitz geschrieben:
> >> If there is no BlockDriverState in a BlockBackend or if the tray of the
> >> guest device is open, fail all requests (where that is possible) with
> >> -ENOMEDIUM.
> >>
> >> The reason the status of the guest device is taken into account is
> >> because once the guest device's tray is opened, any request on the same
> >> BlockBackend as the guest uses should fail. If the BDS tree is supposed
> >> to be usable even after ejecting it from the guest, a different
> >> BlockBackend must be used.
> >>
> >> Signed-off-by: Max Reitz <mreitz@redhat.com>
> >> Reviewed-by: Eric Blake <eblake@redhat.com>
> > 
> > Do we want to include blk_drain() to make it a no-op instead of
> > crashing?
> 
> Yes, we do, so that would be in patch 20. Thanks for catching that.
> 
> > Also, we're now introducing BlockAIOCBs with a NULL bs with your use of
> > abort_aio_request. I haven't carefully reviewed the implications of this
> > yet, but that should definitely be done before we merge the series.
> 
> That should be patch 12.

Yes, you caught me reviewing just correctness, but not completeness of
patch 12.

Kevin

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Re: [Qemu-devel] [PATCH v5 21/38] block: Add blk_insert_bs()

[Max Reitz]

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On 22.09.2015 16:42, Kevin Wolf wrote:
> Am 18.09.2015 um 17:22 hat Max Reitz geschrieben:
>> This function associates the given BlockDriverState with the given
>> BlockBackend.
>>
>> Signed-off-by: Max Reitz <mreitz@redhat.com>
>> Reviewed-by: Eric Blake <eblake@redhat.com>
>> Reviewed-by: Alberto Garcia <berto@igalia.com>
>> ---
>>  block/block-backend.c          | 16 ++++++++++++++++
>>  include/sysemu/block-backend.h |  1 +
>>  2 files changed, 17 insertions(+)
>>
>> diff --git a/block/block-backend.c b/block/block-backend.c
>> index 33145f8..652385e 100644
>> --- a/block/block-backend.c
>> +++ b/block/block-backend.c
>> @@ -314,6 +314,22 @@ void blk_hide_on_behalf_of_hmp_drive_del(BlockBackend *blk)
>>  }
>>  
>>  /*
>> + * Associates a new BlockDriverState with @blk.
>> + */
>> +void blk_insert_bs(BlockBackend *blk, BlockDriverState *bs)
>> +{
>> +    if (bs->blk == blk) {
>> +        return;
>> +    }
>> +
>> +    assert(!blk->bs);
>> +    assert(!bs->blk);
> 
> Why is it useful to allow reconnecting a BDS to a BB it's already
> connected to? I would have expected that we can assert that this is not
> the case.

We can do that, too, there is no use case. It's just that I in principle
don't like making things an error that do make sense and can trivially
be handled gracefully. But I can see people wanting to hit an assertion
as soon as something looks fishy.

So I'm fine either way. I think Eric asked about the same before, so
that makes two against one now. :-)

>> +    bdrv_ref(bs);
>> +    blk->bs = bs;
>> +    bs->blk = blk;
>> +}
> 
> My series to remove bdrv_swap() introduces a blk_set_bs() function,
> which looks suspiciously similar to this one, except that it allows
> passing a BB that already had a BDS (it gets unrefed then) and that I
> don't assert that the BDS isn't attached to a BB yet (I should do that).
> 
> Do you think that's similar enough to have only one function?

Well, yours looks like blk_remove_bs()+blk_insert_bs() combined. In case
we have called blk_remove_bs() before, it will effectively be the same,
yes. But that difference still bothers me a bit... I'd prefer
implementing blk_set_bs() by calling blk_remove_bs() and then
blk_insert_bs() instead, but since these functions are not available in
your bdrv_swap() series, that would prove rather difficult.

I don't know. Maybe implement it separately for now, and trust that this
series will stay in flight long enough for the bdrv_swap() series to get
merged so I can include a commit cleaning up blk_set_bs() in this series
later on?

Or I can base this series on your bdrv_swap() series. Your call, as I
haven't looked at it yet and thus don't know how long it'll take to get
merged (albeit judging from your series in the past, it won't be too long).

Max


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Re: [Qemu-devel] [PATCH v5 00/38] blockdev: BlockBackend and media

[Wen Congyang]

On 09/22/2015 11:09 PM, Max Reitz wrote:
> On 22.09.2015 16:45, Kevin Wolf wrote:
>> Am 18.09.2015 um 17:22 hat Max Reitz geschrieben:
>>> This series reworks a lot regarding BlockBackend and media. Basically,
>>> it allows empty BlockBackends, that is BBs without a BDS tree.
>>>
>>> Before this series, empty drives are represented by a BlockBackend with
>>> an empty BDS attached to it (a BDS with a NULL driver). However, now we
>>> have BlockBackends, thus an empty drive should be represented by a
>>> BlockBackend without any BDS tree attached to it. This is what this
>>> series does.
>>
>> Patches 1-16 and 18: Reviewed-by: Kevin Wolf <kwolf@redhat.com>
>>
>> I had comments for 17 and 19-21, and can't seem to find a base commit
>> that patch 22 applies cleanly to, so I'm stopping the review here,
>> waiting for another rebase or instructions how to apply the series.
> 
> 16a1b6e97c2a2919fd296db4bea2f9da2ad3cc4d was my base, if that was the
> question. ;-)

It can be applied to the upstream qemu very easily:
s/qmp_marshal_input_/qmp_marshal_/

> 
> Thanks for reviewing!
> 
> Max
> 

Re: [Qemu-devel] [PATCH v5 03/38] blockdev: Allow creation of BDS trees without BB

[Alberto Garcia]

On Fri 18 Sep 2015 05:22:38 PM CEST, Max Reitz <mreitz@redhat.com> wrote:
> If the "id" field is missing from the options given to blockdev-add,
> just omit the BlockBackend and create the BlockDriverState tree alone.
>
> However, if "id" is missing, "node-name" must be specified; otherwise,
> the BDS tree would no longer be accessible.
>
> Many BDS options which are not parsed by bdrv_open() (like caching)
> cannot be specified for these BB-less BDS trees yet. A future patch will
> remove this limitation.
>
> Signed-off-by: Max Reitz <mreitz@redhat.com>

Reviewed-by: Alberto Garcia <berto@igalia.com>

Berto

Re: [Qemu-devel] [PATCH v5 02/38] block: Set BDRV_O_INCOMING in bdrv_fill_options()

[Alberto Garcia]

On Fri 18 Sep 2015 05:22:37 PM CEST, Max Reitz wrote:
> This flag should not be set for the root BDS only, but for any BDS that
> is being created while incoming migration is pending, so setting it is
> moved from blockdev_init() to bdrv_fill_options().
>
> Signed-off-by: Max Reitz <mreitz@redhat.com>

Reviewed-by: Alberto Garcia <berto@igalia.com>

Berto

Re: [Qemu-devel] [PATCH v5 07/38] block: Make bdrv_is_inserted() recursive

[Alberto Garcia]

On Fri 18 Sep 2015 05:22:42 PM CEST, Max Reitz wrote:
> If bdrv_is_inserted() is called on the top level BDS, it should make
> sure all nodes in the BDS tree are actually inserted.
>
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> ---
>  block.c | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/block.c b/block.c
> index 4a089e6..c4fa299 100644
> --- a/block.c
> +++ b/block.c
> @@ -3247,14 +3247,20 @@ void bdrv_invalidate_cache_all(Error **errp)
>  bool bdrv_is_inserted(BlockDriverState *bs)
>  {
>      BlockDriver *drv = bs->drv;
> +    BdrvChild *child;
>  
>      if (!drv) {
>          return false;
>      }
> -    if (!drv->bdrv_is_inserted) {
> -        return true;
> +    if (drv->bdrv_is_inserted) {
> +        return drv->bdrv_is_inserted(bs);
>      }

If there's drv->bdrv_is_inserted then this code stops here and does not
iterate the children, is this correct?

> -    return drv->bdrv_is_inserted(bs);
> +    QLIST_FOREACH(child, &bs->children, next) {
> +        if (!bdrv_is_inserted(child->bs)) {
> +            return false;
> +        }
> +    }
> +    return true;
>  }

Berto

Re: [Qemu-devel] [PATCH v5 08/38] block/raw_bsd: Drop raw_is_inserted()

[Alberto Garcia]

On Fri 18 Sep 2015 05:22:43 PM CEST, Max Reitz <mreitz@redhat.com> wrote:
> With the new automatically-recursive implementation of
> bdrv_is_inserted() checking by default whether all the children of a BDS
> are inserted, we can drop raw's own implementation.
>
> Signed-off-by: Max Reitz <mreitz@redhat.com>

Reviewed-by: Alberto Garcia <berto@igalia.com>

Berto

Re: [Qemu-devel] [PATCH v5 17/38] block: Add BlockBackendRootState

[Alberto Garcia]

On Tue 22 Sep 2015 05:00:05 PM CEST, Max Reitz wrote:

>> The correct way to solve this seems to be that each BB has its own
>> I/O throttling filter. Actually, if we could lift the throttling code
>> to BlockBackend, that might solve the problem.
>
> So yes, as long as we have throttling on the BDS level, something may
> always break when having multiple BBs per BDS, because you'd probably
> want throttling to be on the BB level. But lifting that doesn't seem a
> trivial task, and I don't really know whether I want this in this
> series.
>
> Especially considering that right now you cannot have multiple BBs per
> BDS.
>
> All in all: Yes, before we allow multiple BBs per BDS we want
> throttling to be on the BB level. But this is nothing that should be
> done in or for this series, since right now we do not allow multiple
> BBs per BDS.

I agree that it makes sense to move throttling to the BB level. It's
probably not trivial but I don't think it's too complex either. I can
give it a look once this series has been merged.

Berto

Re: [Qemu-devel] [PATCH v5 17/38] block: Add BlockBackendRootState

[Eric Blake]

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On 09/29/2015 05:17 AM, Alberto Garcia wrote:
> On Tue 22 Sep 2015 05:00:05 PM CEST, Max Reitz wrote:
> 
>>> The correct way to solve this seems to be that each BB has its own
>>> I/O throttling filter. Actually, if we could lift the throttling code
>>> to BlockBackend, that might solve the problem.
>>
>> So yes, as long as we have throttling on the BDS level, something may
>> always break when having multiple BBs per BDS, because you'd probably
>> want throttling to be on the BB level. But lifting that doesn't seem a
>> trivial task, and I don't really know whether I want this in this
>> series.
>>
>> Especially considering that right now you cannot have multiple BBs per
>> BDS.
>>
>> All in all: Yes, before we allow multiple BBs per BDS we want
>> throttling to be on the BB level. But this is nothing that should be
>> done in or for this series, since right now we do not allow multiple
>> BBs per BDS.
> 
> I agree that it makes sense to move throttling to the BB level. It's
> probably not trivial but I don't think it's too complex either. I can
> give it a look once this series has been merged.

Ultimately, I think we want throttling at both levels.  I can make the
argument that in a cloud, a guest should not be able to consume more
than X resources (throttling at the BB, regardless of what BDS tree it
is associated with); but I can also argue that I may want to throttle
specific BDS (a backing chain with network backing file and local active
file: throttle the backing file to limit network traffic, and the guest
gets faster as it moves more local; or conversely, a common backing file
and one-off guest: throttle the active layer to do performance analysis
of the bottlenecks where the guest differs from the common backing layer).

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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Re: [Qemu-devel] [PATCH v5 17/38] block: Add BlockBackendRootState

[Kevin Wolf]

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Am 29.09.2015 um 14:30 hat Eric Blake geschrieben:
> On 09/29/2015 05:17 AM, Alberto Garcia wrote:
> > On Tue 22 Sep 2015 05:00:05 PM CEST, Max Reitz wrote:
> > 
> >>> The correct way to solve this seems to be that each BB has its own
> >>> I/O throttling filter. Actually, if we could lift the throttling code
> >>> to BlockBackend, that might solve the problem.
> >>
> >> So yes, as long as we have throttling on the BDS level, something may
> >> always break when having multiple BBs per BDS, because you'd probably
> >> want throttling to be on the BB level. But lifting that doesn't seem a
> >> trivial task, and I don't really know whether I want this in this
> >> series.
> >>
> >> Especially considering that right now you cannot have multiple BBs per
> >> BDS.
> >>
> >> All in all: Yes, before we allow multiple BBs per BDS we want
> >> throttling to be on the BB level. But this is nothing that should be
> >> done in or for this series, since right now we do not allow multiple
> >> BBs per BDS.
> > 
> > I agree that it makes sense to move throttling to the BB level. It's
> > probably not trivial but I don't think it's too complex either. I can
> > give it a look once this series has been merged.
> 
> Ultimately, I think we want throttling at both levels.  I can make the
> argument that in a cloud, a guest should not be able to consume more
> than X resources (throttling at the BB, regardless of what BDS tree it
> is associated with); but I can also argue that I may want to throttle
> specific BDS (a backing chain with network backing file and local active
> file: throttle the backing file to limit network traffic, and the guest
> gets faster as it moves more local; or conversely, a common backing file
> and one-off guest: throttle the active layer to do performance analysis
> of the bottlenecks where the guest differs from the common backing layer).

Yes, but the throttling that we currently have is the one that belongs
into BlockBackend. This becomes very clear when you consider that the
throttling moves to the new top when you create live snapshots.

Throttling for individual BDSes should be done by a filter block driver.
In fact, I also suspect that the BB-level filtering should eventually be
done by a filter block driver, but that's something for which we don't
have a clear design yet.

Kevin

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Re: [Qemu-devel] [PATCH v5 24/38] blockdev: Pull out blockdev option extraction

[Alberto Garcia]

On Fri 18 Sep 2015 05:22:59 PM CEST, Max Reitz <mreitz@redhat.com> wrote:
> Extract some of the blockdev option extraction code from blockdev_init()
> into its own function. This simplifies blockdev_init() and will allow
> reusing the code in a different function added in a follow-up patch.
>
> Signed-off-by: Max Reitz <mreitz@redhat.com>

Reviewed-by: Alberto Garcia <berto@igalia.com>

Berto

Re: [Qemu-devel] [PATCH v5 07/38] block: Make bdrv_is_inserted() recursive

[Max Reitz]

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On 29.09.2015 11:15, Alberto Garcia wrote:
> On Fri 18 Sep 2015 05:22:42 PM CEST, Max Reitz wrote:
>> If bdrv_is_inserted() is called on the top level BDS, it should make
>> sure all nodes in the BDS tree are actually inserted.
>>
>> Signed-off-by: Max Reitz <mreitz@redhat.com>
>> ---
>>  block.c | 12 +++++++++---
>>  1 file changed, 9 insertions(+), 3 deletions(-)
>>
>> diff --git a/block.c b/block.c
>> index 4a089e6..c4fa299 100644
>> --- a/block.c
>> +++ b/block.c
>> @@ -3247,14 +3247,20 @@ void bdrv_invalidate_cache_all(Error **errp)
>>  bool bdrv_is_inserted(BlockDriverState *bs)
>>  {
>>      BlockDriver *drv = bs->drv;
>> +    BdrvChild *child;
>>  
>>      if (!drv) {
>>          return false;
>>      }
>> -    if (!drv->bdrv_is_inserted) {
>> -        return true;
>> +    if (drv->bdrv_is_inserted) {
>> +        return drv->bdrv_is_inserted(bs);
>>      }
> 
> If there's drv->bdrv_is_inserted then this code stops here and does not
> iterate the children, is this correct?

Yes, that is how it's supposed to be.

Max

>> -    return drv->bdrv_is_inserted(bs);
>> +    QLIST_FOREACH(child, &bs->children, next) {
>> +        if (!bdrv_is_inserted(child->bs)) {
>> +            return false;
>> +        }
>> +    }
>> +    return true;
>>  }
> 
> Berto
> 



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Re: [Qemu-devel] [PATCH v5 22/38] block: Prepare for NULL BDS

[Kevin Wolf]

Am 18.09.2015 um 17:22 hat Max Reitz geschrieben:
> blk_bs() will not necessarily return a non-NULL value any more (unless
> blk_is_available() is true or it can be assumed to otherwise, e.g.
> because it is called immediately after a successful blk_new_with_bs() or
> blk_new_open()).
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>

> @@ -1922,8 +1939,9 @@ void qmp_change_blockdev(const char *device, const char *filename,
>          return;
>      }
>      bs = blk_bs(blk);
> +    new_bs = !bs;
>  
> -    aio_context = bdrv_get_aio_context(bs);
> +    aio_context = blk_get_aio_context(blk);
>      aio_context_acquire(aio_context);
>  
>      eject_device(blk, 0, &err);
> @@ -1932,10 +1950,18 @@ void qmp_change_blockdev(const char *device, const char *filename,
>          goto out;
>      }
>  
> -    bdrv_flags = bdrv_is_read_only(bs) ? 0 : BDRV_O_RDWR;
> -    bdrv_flags |= bdrv_is_snapshot(bs) ? BDRV_O_SNAPSHOT : 0;
> +    bdrv_flags = blk_is_read_only(blk) ? 0 : BDRV_O_RDWR;
> +    bdrv_flags |= blk_get_root_state(blk)->open_flags & ~BDRV_O_RDWR;
>  
> -    qmp_bdrv_open_encrypted(bs, filename, bdrv_flags, format, NULL, errp);
> +    qmp_bdrv_open_encrypted(&bs, filename, bdrv_flags, format, NULL, &err);
> +    if (err) {
> +        error_propagate(errp, err);
> +    } else if (new_bs) {
> +        blk_insert_bs(blk, bs);
> +        /* Has been sent automatically by bdrv_open() if blk_bs(blk) was not
> +         * NULL */
> +        blk_dev_change_media_cb(blk, true);
> +    }

Was this change supposed to be in this patch? It looks like it's doing a
bit more than just fixing blk_bs() == NULL cases.

Kevin

Re: [Qemu-devel] [PATCH v5 22/38] block: Prepare for NULL BDS

[Max Reitz]

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On 07.10.2015 12:43, Kevin Wolf wrote:
> Am 18.09.2015 um 17:22 hat Max Reitz geschrieben:
>> blk_bs() will not necessarily return a non-NULL value any more (unless
>> blk_is_available() is true or it can be assumed to otherwise, e.g.
>> because it is called immediately after a successful blk_new_with_bs() or
>> blk_new_open()).
>>
>> Signed-off-by: Max Reitz <mreitz@redhat.com>
> 
>> @@ -1922,8 +1939,9 @@ void qmp_change_blockdev(const char *device, const char *filename,
>>          return;
>>      }
>>      bs = blk_bs(blk);
>> +    new_bs = !bs;
>>  
>> -    aio_context = bdrv_get_aio_context(bs);
>> +    aio_context = blk_get_aio_context(blk);
>>      aio_context_acquire(aio_context);
>>  
>>      eject_device(blk, 0, &err);
>> @@ -1932,10 +1950,18 @@ void qmp_change_blockdev(const char *device, const char *filename,
>>          goto out;
>>      }
>>  
>> -    bdrv_flags = bdrv_is_read_only(bs) ? 0 : BDRV_O_RDWR;
>> -    bdrv_flags |= bdrv_is_snapshot(bs) ? BDRV_O_SNAPSHOT : 0;
>> +    bdrv_flags = blk_is_read_only(blk) ? 0 : BDRV_O_RDWR;
>> +    bdrv_flags |= blk_get_root_state(blk)->open_flags & ~BDRV_O_RDWR;
>>  
>> -    qmp_bdrv_open_encrypted(bs, filename, bdrv_flags, format, NULL, errp);
>> +    qmp_bdrv_open_encrypted(&bs, filename, bdrv_flags, format, NULL, &err);
>> +    if (err) {
>> +        error_propagate(errp, err);
>> +    } else if (new_bs) {
>> +        blk_insert_bs(blk, bs);
>> +        /* Has been sent automatically by bdrv_open() if blk_bs(blk) was not
>> +         * NULL */
>> +        blk_dev_change_media_cb(blk, true);
>> +    }
> 
> Was this change supposed to be in this patch? It looks like it's doing a
> bit more than just fixing blk_bs() == NULL cases.

Yes, it's supposed to be here. Before this patch, qmp_change_blockdev()
took the BDS from the specified BB, closed it (eject_device()) and
"re-opened" it (bdrv_open() in qmp_bdrv_open_encrypted()), and we're done.

Now, the BB does not have to have a BDS anymore. In this case
(new_bs == true) qmp_bdrv_open_encrypted() will now create a new BDS
(which is why now it needs to take a BDS ** instead of a plain BDS *)
and we have to then attach it to the BB.

The comment above blk_dev_change_media_cb() then explains why we need
that, too.

Later ("Implement change with basic operations") I'll drop it altogether
anyway, and then, since the "eject" part of "change" will then detach
the BDS from the BB, we'll always have the "need to attach a new BDS to
the BB" case.

Max


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