[Qemu-devel] [PATCH v7 00/39] blockdev: BlockBackend and media

[Qemu-devel] [PATCH v7 00/39] 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 v7 changes:
- Rebased
- Addressed Kevin's comments for v6


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 26 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: Needed for patch 18
18: 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))
19: Preparation for BDS-less BBs
20: Preparation for BDS-less BBs
21: Preparation for BDS-less BBs
22: Ability to add BDS trees to empty BBs ("inserting a medium")
23: Preparation for BDS-less BBs (needs patch 22)
24: One goal of this series, and fixes the "opening tray" event for
    empty drives when shutting down qemu
25: Needed for patch 26
26: Completion of what patch 3 begun
27: Ability to detach BDS trees from BBs

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

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

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

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


v7:
- Patch 4: Rebase conflict
- Patch 23: [Kevin]
  - Drop blk_is_available() check in drive_backup_prepare(); the same
    check is done by qmp_drive_backup() already
  - eject_device(): If there is no BDS attached to the BB, return
    immediately without doing anything
  - Simplify qmp_bdrv_open_encrypted()
  - Make last error path in qmp_change_blockdev() more explicit
  - Move the contents of two consecutive if (bs [&& ...]) blocks into a
    single if (bs) block
- Patch 24: Drop the unnecessary and now actually wrong block which sets
  BDRV_O_INCOMING [Kevin]
- Patch 25:
  - Make parameters for extract_common_blockdev_options() optional; we
    won't need the throttle options in bds_tree_init()
  - Reorder the parameters (throttling group and throttle config should
    be together, because that makes sense)
  - Rebase conflict (CONFIG_LINUX_AIO dropped)
- Patch 26: Do not allow throttle configuration for BB-less BDS trees
  [Kevin]
- Patch 33: Rebase conflicts due to changes to patch 23


git-backport-diff against v6:

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

001/39:[----] [--] 'block: Remove host floppy support'
002/39:[----] [--] 'block: Set BDRV_O_INCOMING in bdrv_fill_options()'
003/39:[----] [--] 'blockdev: Allow creation of BDS trees without BB'
004/39:[0002] [FC] 'iotests: Only create BB if necessary'
005/39:[----] [--] 'block: Make bdrv_is_inserted() return a bool'
006/39:[----] [--] 'block: Add blk_is_available()'
007/39:[----] [--] 'block: Make bdrv_is_inserted() recursive'
008/39:[----] [--] 'block/raw_bsd: Drop raw_is_inserted()'
009/39:[----] [--] 'block: Invoke change media CB before NULLing drv'
010/39:[----] [--] 'hw/block/fdc: Implement tray status'
011/39:[----] [--] 'hw/usb-storage: Check whether BB is inserted'
012/39:[----] [--] 'block: Fix BB AIOCB AioContext without BDS'
013/39:[----] [--] 'block: Move guest_block_size into BlockBackend'
014/39:[----] [--] 'block: Remove wr_highest_sector from BlockAcctStats'
015/39:[----] [--] 'block: Move BlockAcctStats into BlockBackend'
016/39:[----] [--] 'block: Move I/O status and error actions into BB'
017/39:[----] [--] 'block/throttle-groups: Make incref/decref public'
018/39:[----] [--] 'block: Add BlockBackendRootState'
019/39:[----] [--] 'block: Make some BB functions fall back to BBRS'
020/39:[----] [--] 'block: Fail requests to empty BlockBackend'
021/39:[----] [--] 'block: Prepare remaining BB functions for NULL BDS'
022/39:[----] [--] 'block: Add blk_insert_bs()'
023/39:[0037] [FC] 'block: Prepare for NULL BDS'
024/39:[0004] [FC] 'blockdev: Do not create BDS for empty drive'
025/39:[0176] [FC] 'blockdev: Pull out blockdev option extraction'
026/39:[0067] [FC] 'blockdev: Allow more options for BB-less BDS tree'
027/39:[----] [--] 'block: Add blk_remove_bs()'
028/39:[----] [--] 'blockdev: Add blockdev-open-tray'
029/39:[----] [--] 'blockdev: Add blockdev-close-tray'
030/39:[----] [--] 'blockdev: Add blockdev-remove-medium'
031/39:[----] [--] 'blockdev: Add blockdev-insert-medium'
032/39:[----] [--] 'blockdev: Implement eject with basic operations'
033/39:[0022] [FC] 'blockdev: Implement change with basic operations'
034/39:[----] [--] 'block: Inquire tray state before tray-moved events'
035/39:[----] [--] 'qmp: Introduce blockdev-change-medium'
036/39:[----] [--] 'hmp: Use blockdev-change-medium for change command'
037/39:[----] [--] 'blockdev: read-only-mode for blockdev-change-medium'
038/39:[----] [--] 'hmp: Add read-only-mode option to change command'
039/39:[----] [--] 'iotests: Add test for change-related QMP commands'


Max Reitz (39):
  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/throttle-groups: Make incref/decref public
  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           | 389 ++++++++++++++++--
 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 +-
 block/throttle-groups.c         |  19 +-
 blockdev.c                      | 855 ++++++++++++++++++++++++++++------------
 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/block/throttle-groups.h |   3 +
 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 +
 42 files changed, 2248 insertions(+), 833 deletions(-)
 create mode 100755 tests/qemu-iotests/118
 create mode 100644 tests/qemu-iotests/118.out

-- 
2.6.1

[Qemu-devel] [PATCH v7 01/39] 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>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@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 3a527f0..2e3db44 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;
@@ -635,7 +623,7 @@ 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;
     }
 
@@ -2187,47 +2175,6 @@ 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;
@@ -2256,8 +2203,8 @@ 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;
@@ -2267,14 +2214,6 @@ 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,
@@ -2318,14 +2257,13 @@ 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;
 
@@ -2405,155 +2343,6 @@ 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)
@@ -2831,7 +2620,6 @@ 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
-- 
2.6.1

[Qemu-devel] [PATCH v7 02/39] 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>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
---
 block.c    | 4 ++++
 blockdev.c | 4 ----
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/block.c b/block.c
index 09f2a75..4fa2057 100644
--- a/block.c
+++ b/block.c
@@ -1081,6 +1081,10 @@ 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 8141b6b..27398b1 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -537,10 +537,6 @@ 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,
-- 
2.6.1

[Qemu-devel] [PATCH v7 03/39] 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>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.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 27398b1..0785557 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -3026,17 +3026,12 @@ 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().
@@ -3064,14 +3059,37 @@ 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"}
 
-- 
2.6.1

[Qemu-devel] [PATCH v7 04/39] 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 51873ff..e4b4c6c 100755
--- a/tests/qemu-iotests/081
+++ b/tests/qemu-iotests/081
@@ -102,17 +102,29 @@ $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"
@@ -120,7 +132,7 @@ 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 044793d..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": "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": ""}
-- 
2.6.1

[Qemu-devel] [PATCH v7 05/39] 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>
Reviewed-by: Kevin Wolf <kwolf@redhat.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 4fa2057..2a77169 100644
--- a/block.c
+++ b/block.c
@@ -3140,14 +3140,16 @@ 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 2256551..1db002c 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -769,7 +769,7 @@ 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 2e3db44..918c756 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -2398,15 +2398,13 @@ 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)
@@ -2532,7 +2530,7 @@ 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 63ee911..3c7b413 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->bs, offset);
 }
 
-static int raw_is_inserted(BlockDriverState *bs)
+static bool raw_is_inserted(BlockDriverState *bs)
 {
     return bdrv_is_inserted(bs->file->bs);
 }
diff --git a/include/block/block.h b/include/block/block.h
index 6d70eb4..db860ef 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -399,7 +399,7 @@ 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 c0e6513..40d40df 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -212,7 +212,7 @@ 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);
-- 
2.6.1

[Qemu-devel] [PATCH v7 06/39] 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>
Reviewed-by: Kevin Wolf <kwolf@redhat.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 1db002c..74642dc 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -771,7 +771,12 @@ 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);
-- 
2.6.1

[Qemu-devel] [PATCH v7 07/39] 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>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
---
 block.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/block.c b/block.c
index 2a77169..0f23a98 100644
--- a/block.c
+++ b/block.c
@@ -3143,14 +3143,20 @@ 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;
 }
 
 /**
-- 
2.6.1

[Qemu-devel] [PATCH v7 08/39] 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>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
---
 block/raw_bsd.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/block/raw_bsd.c b/block/raw_bsd.c
index 3c7b413..0aded31 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->bs, offset);
 }
 
-static bool raw_is_inserted(BlockDriverState *bs)
-{
-    return bdrv_is_inserted(bs->file->bs);
-}
-
 static int raw_media_changed(BlockDriverState *bs)
 {
     return bdrv_media_changed(bs->file->bs);
@@ -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,
-- 
2.6.1

[Qemu-devel] [PATCH v7 09/39] 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 false
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>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
---
 block.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/block.c b/block.c
index 0f23a98..59a2a62 100644
--- a/block.c
+++ b/block.c
@@ -1912,6 +1912,10 @@ 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;
 
@@ -1950,10 +1954,6 @@ void bdrv_close(BlockDriverState *bs)
         bs->full_open_options = NULL;
     }
 
-    if (bs->blk) {
-        blk_dev_change_media_cb(bs->blk, false);
-    }
-
     QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) {
         g_free(ban);
     }
-- 
2.6.1

[Qemu-devel] [PATCH v7 10/39] 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>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@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);
-- 
2.6.1

[Qemu-devel] [PATCH v7 11/39] 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>
Reviewed-by: Kevin Wolf <kwolf@redhat.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;
+            }
         }
     }
 
-- 
2.6.1

[Qemu-devel] [PATCH v7 12/39] 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>
Reviewed-by: Kevin Wolf <kwolf@redhat.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 74642dc..c7e0f7b 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),
 };
 
@@ -558,6 +562,7 @@ 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);
@@ -831,7 +836,17 @@ 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)
-- 
2.6.1

[Qemu-devel] [PATCH v7 13/39] 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>
Reviewed-by: Kevin Wolf <kwolf@redhat.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 59a2a62..2f69ec7 100644
--- a/block.c
+++ b/block.c
@@ -857,7 +857,6 @@ static int bdrv_open_common(BlockDriverState *bs, BdrvChild *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);
@@ -2002,7 +2001,6 @@ 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;
@@ -3207,11 +3205,6 @@ 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 c7e0f7b..7bc2eb1 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 {
@@ -351,7 +354,7 @@ 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);
 }
 
@@ -806,7 +809,7 @@ 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 db860ef..0f40d9f 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -466,7 +466,6 @@ 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 40d40df..e79d8c0 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -411,9 +411,6 @@ 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;
 
-- 
2.6.1

[Qemu-devel] [PATCH v7 14/39] 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>
Reviewed-by: Kevin Wolf <kwolf@redhat.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 5311473..b80044b 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1151,7 +1151,9 @@ 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 355ba32..0360126 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->bs, 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 e79d8c0..b8e1c59 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -402,6 +402,9 @@ 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 2b52980..d7cf0ff 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -2520,8 +2520,8 @@ 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
-- 
2.6.1

[Qemu-devel] [PATCH v7 15/39] 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>
Reviewed-by: Kevin Wolf <kwolf@redhat.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 2f69ec7..40be84b 100644
--- a/block.c
+++ b/block.c
@@ -4153,14 +4153,3 @@ 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 7bc2eb1..a52037b 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 {
@@ -892,7 +895,7 @@ 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 b80044b..2fd7a1d 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"
@@ -1905,7 +1906,10 @@ 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 0360126..7c8209b 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 0f40d9f..f1f6300 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -621,6 +621,4 @@ 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 b8e1c59..f9c7ec5 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -399,9 +399,6 @@ 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;
 
-- 
2.6.1

[Qemu-devel] [PATCH v7 16/39] 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>
---
 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 40be84b..6f239a4 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]);
@@ -2005,14 +2004,6 @@ static void bdrv_move_feature_fields(BlockDriverState *bs_dest,
 
     bs_dest->enable_write_cache = bs_src->enable_write_cache;
 
-    /* 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;
 }
@@ -2499,82 +2490,6 @@ 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;
@@ -3602,46 +3517,6 @@ 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 5696431..ec01db8 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)
@@ -215,7 +216,9 @@ 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 = {
@@ -360,8 +363,10 @@ 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);
 
@@ -451,7 +456,9 @@ 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));
@@ -480,7 +487,7 @@ 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 a52037b..2708ad1 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 {
@@ -330,7 +336,7 @@ 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;
 }
 
@@ -462,7 +468,47 @@ 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,
@@ -738,21 +784,81 @@ 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 7e43511..b1252a1 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"
@@ -599,7 +600,9 @@ 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;
@@ -621,7 +624,9 @@ 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 7c8209b..3b46f97 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 3f64fa2..25af7ef 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 {
     /*
@@ -222,7 +223,7 @@ 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 0785557..433c4e2 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -549,7 +549,7 @@ 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)) {
@@ -2168,8 +2168,8 @@ 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 d87869c..69461b4 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"
@@ -354,8 +355,8 @@ 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 f1f6300..28d903c 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -174,11 +174,6 @@ 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);
@@ -389,12 +384,6 @@ 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 f9c7ec5..009d6ea 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -414,12 +414,6 @@ 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 d9ecede..ff54e5a 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);
-- 
2.6.1

[Qemu-devel] [PATCH v7 17/39] block/throttle-groups: Make incref/decref public

[Max Reitz]

Throttle groups are not necessarily referenced by BDSs alone; a later
patch will essentially allow BBs to reference them, too. Make the
ref/unref functions public so that reference can be properly accounted
for.

Their interface is slightly adjusted in that they return and take a
ThrottleState pointer, respectively, instead of a ThrottleGroup pointer.
Functionally, they are equivalent, but since ThrottleGroup is not meant
to be used outside of block/throttle-groups.c, ThrottleState is easier
to handle.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
---
 block/throttle-groups.c         | 19 +++++++++++--------
 include/block/throttle-groups.h |  3 +++
 2 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/block/throttle-groups.c b/block/throttle-groups.c
index 1abc6fc..20cb216 100644
--- a/block/throttle-groups.c
+++ b/block/throttle-groups.c
@@ -76,9 +76,9 @@ static QTAILQ_HEAD(, ThrottleGroup) throttle_groups =
  * created.
  *
  * @name: the name of the ThrottleGroup
- * @ret:  the ThrottleGroup
+ * @ret:  the ThrottleState member of the ThrottleGroup
  */
-static ThrottleGroup *throttle_group_incref(const char *name)
+ThrottleState *throttle_group_incref(const char *name)
 {
     ThrottleGroup *tg = NULL;
     ThrottleGroup *iter;
@@ -108,7 +108,7 @@ static ThrottleGroup *throttle_group_incref(const char *name)
 
     qemu_mutex_unlock(&throttle_groups_lock);
 
-    return tg;
+    return &tg->ts;
 }
 
 /* Decrease the reference count of a ThrottleGroup.
@@ -116,10 +116,12 @@ static ThrottleGroup *throttle_group_incref(const char *name)
  * When the reference count reaches zero the ThrottleGroup is
  * destroyed.
  *
- * @tg:  The ThrottleGroup to unref
+ * @ts:  The ThrottleGroup to unref, given by its ThrottleState member
  */
-static void throttle_group_unref(ThrottleGroup *tg)
+void throttle_group_unref(ThrottleState *ts)
 {
+    ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
+
     qemu_mutex_lock(&throttle_groups_lock);
     if (--tg->refcount == 0) {
         QTAILQ_REMOVE(&throttle_groups, tg, list);
@@ -401,7 +403,8 @@ static void write_timer_cb(void *opaque)
 void throttle_group_register_bs(BlockDriverState *bs, const char *groupname)
 {
     int i;
-    ThrottleGroup *tg = throttle_group_incref(groupname);
+    ThrottleState *ts = throttle_group_incref(groupname);
+    ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
     int clock_type = QEMU_CLOCK_REALTIME;
 
     if (qtest_enabled()) {
@@ -409,7 +412,7 @@ void throttle_group_register_bs(BlockDriverState *bs, const char *groupname)
         clock_type = QEMU_CLOCK_VIRTUAL;
     }
 
-    bs->throttle_state = &tg->ts;
+    bs->throttle_state = ts;
 
     qemu_mutex_lock(&tg->lock);
     /* If the ThrottleGroup is new set this BlockDriverState as the token */
@@ -461,7 +464,7 @@ void throttle_group_unregister_bs(BlockDriverState *bs)
     throttle_timers_destroy(&bs->throttle_timers);
     qemu_mutex_unlock(&tg->lock);
 
-    throttle_group_unref(tg);
+    throttle_group_unref(&tg->ts);
     bs->throttle_state = NULL;
 }
 
diff --git a/include/block/throttle-groups.h b/include/block/throttle-groups.h
index fab113f..f3b75b3 100644
--- a/include/block/throttle-groups.h
+++ b/include/block/throttle-groups.h
@@ -30,6 +30,9 @@
 
 const char *throttle_group_get_name(BlockDriverState *bs);
 
+ThrottleState *throttle_group_incref(const char *name);
+void throttle_group_unref(ThrottleState *ts);
+
 void throttle_group_config(BlockDriverState *bs, ThrottleConfig *cfg);
 void throttle_group_get_config(BlockDriverState *bs, ThrottleConfig *cfg);
 
-- 
2.6.1

[Qemu-devel] [PATCH v7 18/39] 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: Kevin Wolf <kwolf@redhat.com>
---
 block/block-backend.c          | 40 ++++++++++++++++++++++++++++++++++++++++
 include/block/block_int.h      | 10 ++++++++++
 include/qemu/typedefs.h        |  1 +
 include/sysemu/block-backend.h |  2 ++
 4 files changed, 53 insertions(+)

diff --git a/block/block-backend.c b/block/block-backend.c
index 2708ad1..6a3f0c7 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 +166,10 @@ static void blk_delete(BlockBackend *blk)
         bdrv_unref(blk->bs);
         blk->bs = NULL;
     }
+    if (blk->root_state.throttle_state) {
+        g_free(blk->root_state.throttle_group);
+        throttle_group_unref(blk->root_state.throttle_state);
+    }
     /* Avoid double-remove after blk_hide_on_behalf_of_hmp_drive_del() */
     if (blk->name[0]) {
         QTAILQ_REMOVE(&blk_backends, blk, link);
@@ -1067,3 +1076,34 @@ 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;
+
+    if (blk->root_state.throttle_group) {
+        g_free(blk->root_state.throttle_group);
+        throttle_group_unref(blk->root_state.throttle_state);
+    }
+    if (blk->bs->throttle_state) {
+        const char *name = throttle_group_get_name(blk->bs);
+        blk->root_state.throttle_group = g_strdup(name);
+        blk->root_state.throttle_state = throttle_group_incref(name);
+    } else {
+        blk->root_state.throttle_group = NULL;
+        blk->root_state.throttle_state = 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 009d6ea..e472a03 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -26,6 +26,7 @@
 
 #include "block/accounting.h"
 #include "block/block.h"
+#include "block/throttle-groups.h"
 #include "qemu/option.h"
 #include "qemu/queue.h"
 #include "block/coroutine.h"
@@ -449,6 +450,15 @@ struct BlockDriverState {
     NotifierWithReturn write_threshold_notifier;
 };
 
+struct BlockBackendRootState {
+    int open_flags;
+    bool read_only;
+    BlockdevDetectZeroesOptions detect_zeroes;
+
+    char *throttle_group;
+    ThrottleState *throttle_state;
+};
+
 static inline BlockDriverState *backing_bs(BlockDriverState *bs)
 {
     return bs->backing ? bs->backing->bs : NULL;
diff --git a/include/qemu/typedefs.h b/include/qemu/typedefs.h
index d4a8f7a..d961362 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);
-- 
2.6.1

[Qemu-devel] [PATCH v7 19/39] 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.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
---
 block/block-backend.c | 28 ++++++++++++++++++++++++----
 1 file changed, 24 insertions(+), 4 deletions(-)

diff --git a/block/block-backend.c b/block/block-backend.c
index 6a3f0c7..d790870 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -872,7 +872,11 @@ 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)
@@ -882,12 +886,24 @@ int blk_is_sg(BlockBackend *blk)
 
 int blk_enable_write_cache(BlockBackend *blk)
 {
-    return bdrv_enable_write_cache(blk->bs);
+    if (blk->bs) {
+        return bdrv_enable_write_cache(blk->bs);
+    } else {
+        return !!(blk->root_state.open_flags & BDRV_O_CACHE_WB);
+    }
 }
 
 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);
+    } else {
+        if (wce) {
+            blk->root_state.open_flags |= BDRV_O_CACHE_WB;
+        } else {
+            blk->root_state.open_flags &= ~BDRV_O_CACHE_WB;
+        }
+    }
 }
 
 void blk_invalidate_cache(BlockBackend *blk, Error **errp)
@@ -917,7 +933,11 @@ 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)
-- 
2.6.1

[Qemu-devel] [PATCH v7 20/39] 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>
Reviewed-by: Kevin Wolf <kwolf@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 d790870..2779c22 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -529,7 +529,7 @@ 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;
     }
 
@@ -668,6 +668,10 @@ 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);
 }
 
@@ -678,6 +682,10 @@ 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);
 }
 
@@ -708,6 +716,10 @@ 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);
 }
 
@@ -749,12 +761,20 @@ 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);
 }
 
@@ -770,11 +790,19 @@ 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);
 }
 
@@ -908,6 +936,11 @@ 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);
 }
 
@@ -1063,6 +1096,10 @@ 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);
 }
 
@@ -1079,21 +1116,37 @@ 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);
 }
 
-- 
2.6.1

[Qemu-devel] [PATCH v7 21/39] 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: Kevin Wolf <kwolf@redhat.com>
---
 block/block-backend.c | 72 +++++++++++++++++++++++++++++++++++++++------------
 1 file changed, 56 insertions(+), 16 deletions(-)

diff --git a/block/block-backend.c b/block/block-backend.c
index 2779c22..a5c58c5 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -677,7 +677,11 @@ 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)
@@ -813,7 +817,9 @@ int blk_flush_all(void)
 
 void blk_drain(BlockBackend *blk)
 {
-    bdrv_drain(blk->bs);
+    if (blk->bs) {
+        bdrv_drain(blk->bs);
+    }
 }
 
 void blk_drain_all(void)
@@ -909,6 +915,10 @@ int blk_is_read_only(BlockBackend *blk)
 
 int blk_is_sg(BlockBackend *blk)
 {
+    if (!blk->bs) {
+        return 0;
+    }
+
     return bdrv_is_sg(blk->bs);
 }
 
@@ -956,12 +966,16 @@ 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)
@@ -975,7 +989,11 @@ 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)
@@ -990,22 +1008,32 @@ 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)
@@ -1025,15 +1053,19 @@ 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,
@@ -1042,23 +1074,31 @@ 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)
-- 
2.6.1

[Qemu-devel] [PATCH v7 22/39] 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: Kevin Wolf <kwolf@redhat.com>
---
 block/block-backend.c          | 11 +++++++++++
 include/sysemu/block-backend.h |  1 +
 2 files changed, 12 insertions(+)

diff --git a/block/block-backend.c b/block/block-backend.c
index a5c58c5..19fdaae 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -334,6 +334,17 @@ 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)
+{
+    assert(!blk->bs && !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);
 
-- 
2.6.1

[Qemu-devel] [PATCH v7 23/39] 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          | 204 ++++++++++++++++++++++++++++++++++------------------
 hw/block/xen_disk.c |   4 +-
 migration/block.c   |   5 ++
 monitor.c           |   4 ++
 6 files changed, 154 insertions(+), 72 deletions(-)

diff --git a/block.c b/block.c
index 6f239a4..f4dec11 100644
--- a/block.c
+++ b/block.c
@@ -2683,6 +2683,11 @@ 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 3b46f97..ec0f513 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 433c4e2..c9271d2 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;
         }
     }
@@ -1038,6 +1040,10 @@ 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) {
@@ -1117,7 +1123,9 @@ 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;
@@ -1129,11 +1137,14 @@ 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;
@@ -1307,16 +1318,16 @@ 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;
@@ -1568,7 +1579,6 @@ 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;
@@ -1582,10 +1592,9 @@ 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);
 
     qmp_drive_backup(backup->device, backup->target,
@@ -1602,7 +1611,7 @@ static void drive_backup_prepare(BlkTransactionState *common, Error **errp)
         return;
     }
 
-    state->bs = bs;
+    state->bs = blk_bs(blk);
     state->job = state->bs->job;
 }
 
@@ -1637,8 +1646,7 @@ 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);
@@ -1649,18 +1657,16 @@ 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;
@@ -1678,7 +1684,7 @@ static void blockdev_backup_prepare(BlkTransactionState *common, Error **errp)
         return;
     }
 
-    state->bs = bs;
+    state->bs = blk_bs(blk);
     state->job = state->bs->job;
 }
 
@@ -1816,6 +1822,11 @@ static void eject_device(BlockBackend *blk, int force, Error **errp)
     BlockDriverState *bs = blk_bs(blk);
     AioContext *aio_context;
 
+    if (!bs) {
+        /* No medium inserted, so there is nothing to do */
+        return;
+    }
+
     aio_context = bdrv_get_aio_context(bs);
     aio_context_acquire(aio_context);
 
@@ -1882,7 +1893,8 @@ 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)
 {
@@ -1895,13 +1907,13 @@ 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;
     }
 
-    bdrv_add_key(bs, password, errp);
+    bdrv_add_key(*pbs, password, errp);
 }
 
 void qmp_change_blockdev(const char *device, const char *filename,
@@ -1911,6 +1923,7 @@ 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);
@@ -1920,8 +1933,9 @@ 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);
@@ -1930,10 +1944,21 @@ 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);
+        goto out;
+    }
+
+    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);
@@ -1973,7 +1998,15 @@ 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;
@@ -2008,12 +2041,9 @@ 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. */
@@ -2029,6 +2059,7 @@ 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);
 }
 
@@ -2141,7 +2172,6 @@ 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"
@@ -2149,16 +2179,19 @@ 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)) {
-        error_report_err(local_err);
-        aio_context_release(aio_context);
-        return;
-    }
+    bs = blk_bs(blk);
+    if (bs) {
+        if (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);
+        bdrv_close(bs);
+    }
 
     /* if we have a device attached to this BlockDriverState
      * then we need to make the drive anonymous until the device
@@ -2291,11 +2324,16 @@ 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;
     }
@@ -2366,11 +2404,16 @@ 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;
     }
@@ -2476,17 +2519,17 @@ 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;
@@ -2583,7 +2626,7 @@ 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;
@@ -2604,17 +2647,27 @@ 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);
@@ -2691,15 +2744,15 @@ 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;
@@ -2829,17 +2882,22 @@ 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;
     }
 
@@ -2848,7 +2906,10 @@ 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;
 }
 
@@ -2955,11 +3016,16 @@ 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 4f1ba2f..301a143 100644
--- a/monitor.c
+++ b/monitor.c
@@ -4145,6 +4145,10 @@ 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) {
-- 
2.6.1

[Qemu-devel] [PATCH v7 24/39] 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 | 68 ++++++++++++++++++++++++++++++++++++--------------------------
 1 file changed, 40 insertions(+), 28 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index c9271d2..faa5218 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -512,16 +512,40 @@ 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;
+    }
+
+    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->throttle_group = g_strdup(throttling_group);
+            blk_rs->throttle_state = throttle_group_incref(throttling_group);
+            blk_rs->throttle_state->cfg = cfg;
+        }
 
         QDECREF(bs_opts);
     } else {
@@ -529,42 +553,30 @@ 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);
-- 
2.6.1

[Qemu-devel] [PATCH v7 25/39] 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 | 213 ++++++++++++++++++++++++++++++++++---------------------------
 1 file changed, 119 insertions(+), 94 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index faa5218..dd4885f 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -350,25 +350,134 @@ static bool check_throttle_config(ThrottleConfig *cfg, Error **errp)
 
 typedef enum { MEDIA_DISK, MEDIA_CDROM } DriveMediaType;
 
+/* All parameters but @opts are optional and may be set to NULL. */
+static void extract_common_blockdev_options(QemuOpts *opts, int *bdrv_flags,
+    const char **throttling_group, ThrottleConfig *throttle_cfg,
+    BlockdevDetectZeroesOptions *detect_zeroes, Error **errp)
+{
+    const char *discard;
+    Error *local_error = NULL;
+    const char *aio;
+
+    if (bdrv_flags) {
+        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;
+        }
+
+        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;
+            }
+        }
+    }
+
+    /* disk I/O throttling */
+    if (throttling_group) {
+        *throttling_group = qemu_opt_get(opts, "throttling.group");
+    }
+
+    if (throttle_cfg) {
+        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);
+
+        if (!check_throttle_config(throttle_cfg, errp)) {
+            return;
+        }
+    }
+
+    if (detect_zeroes) {
+        *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 (bdrv_flags &&
+            *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(). */
@@ -393,35 +502,12 @@ 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;
-    }
 
-    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, &throttling_group, &cfg,
+                                    &detect_zeroes, &error);
+    if (error) {
+        error_propagate(errp, error);
+        goto early_err;
     }
 
     if ((buf = qemu_opt_get(opts, "format")) != NULL) {
@@ -439,43 +525,6 @@ 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);
@@ -494,36 +543,12 @@ 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;
-    }
-
-    bdrv_flags |= ro ? 0 : BDRV_O_RDWR;
-
     /* init */
     if ((!file || !*file) && !has_driver_specific_opts) {
         BlockBackendRootState *blk_rs;
@@ -535,7 +560,7 @@ 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)) {
-- 
2.6.1

[Qemu-devel] [PATCH v7 26/39] 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 | 97 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 91 insertions(+), 6 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index dd4885f..35e5719 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -614,6 +614,54 @@ 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;
+    BlockdevDetectZeroesOptions detect_zeroes;
+    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, NULL, NULL,
+                                    &detect_zeroes, &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;
+
+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)
 {
@@ -3171,18 +3219,14 @@ 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;
         }
     }
@@ -3337,6 +3381,47 @@ 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 = "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),
-- 
2.6.1

[Qemu-devel] [PATCH v7 27/39] 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>
---
 block/block-backend.c          | 12 ++++++++++++
 include/sysemu/block-backend.h |  1 +
 2 files changed, 13 insertions(+)

diff --git a/block/block-backend.c b/block/block-backend.c
index 19fdaae..eb7409c 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -334,6 +334,18 @@ void blk_hide_on_behalf_of_hmp_drive_del(BlockBackend *blk)
 }
 
 /*
+ * Disassociates the currently associated BlockDriverState from @blk.
+ */
+void blk_remove_bs(BlockBackend *blk)
+{
+    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)
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);
-- 
2.6.1

[Qemu-devel] [PATCH v7 28/39] 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 35e5719..aa68c36 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2049,6 +2049,55 @@ 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 d7cf0ff..595aee2 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -3936,6 +3936,45 @@ Example (2):
 EQMP
 
     {
+        .name       = "blockdev-open-tray",
+        .args_type  = "device:s,force:b?",
+        .mhandler.cmd_new = qmp_marshal_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_query_named_block_nodes,
-- 
2.6.1

[Qemu-devel] [PATCH v7 29/39] 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 aa68c36..743e5ca 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2098,6 +2098,29 @@ 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 595aee2..70241ac 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -3975,6 +3975,41 @@ Example:
 EQMP
 
     {
+        .name       = "blockdev-close-tray",
+        .args_type  = "device:s",
+        .mhandler.cmd_new = qmp_marshal_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_query_named_block_nodes,
-- 
2.6.1

[Qemu-devel] [PATCH v7 30/39] 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 743e5ca..a8601ca 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2121,6 +2121,36 @@ 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 70241ac..ca46c80 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -4010,6 +4010,51 @@ Example:
 EQMP
 
     {
+        .name       = "blockdev-remove-medium",
+        .args_type  = "device:s",
+        .mhandler.cmd_new = qmp_marshal_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_query_named_block_nodes,
-- 
2.6.1

[Qemu-devel] [PATCH v7 31/39] 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           | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 qapi/block-core.json | 17 +++++++++++++++++
 qmp-commands.hx      | 37 +++++++++++++++++++++++++++++++++++
 3 files changed, 108 insertions(+)

diff --git a/blockdev.c b/blockdev.c
index a8601ca..a4c278f 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2151,6 +2151,60 @@ 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;
+    }
+
+    if (bs->blk) {
+        error_setg(errp, "Node '%s' is already in use by '%s'", node_name,
+                   blk_name(bs->blk));
+        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 ca46c80..16d7e2a 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -4055,6 +4055,43 @@ Example:
 EQMP
 
     {
+        .name       = "blockdev-insert-medium",
+        .args_type  = "device:s,node-name:s",
+        .mhandler.cmd_new = qmp_marshal_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_query_named_block_nodes,
-- 
2.6.1

[Qemu-devel] [PATCH v7 32/39] 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 a4c278f..0481686 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1941,16 +1941,15 @@ 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,
-- 
2.6.1

[Qemu-devel] [PATCH v7 33/39] 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 | 184 +++++++++++++++++++++++++------------------------------------
 1 file changed, 74 insertions(+), 110 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index 0481686..50e5e74 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1901,44 +1901,6 @@ exit:
     }
 }
 
-
-static void eject_device(BlockBackend *blk, int force, Error **errp)
-{
-    BlockDriverState *bs = blk_bs(blk);
-    AioContext *aio_context;
-
-    if (!bs) {
-        /* No medium inserted, so there is nothing to do */
-        return;
-    }
-
-    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_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;
-        }
-    }
-
-    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;
@@ -1976,78 +1938,6 @@ 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)
-{
-    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;
-    }
-
-    bdrv_add_key(*pbs, 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);
-        goto out;
-    }
-
-    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)
 {
@@ -2204,6 +2094,80 @@ 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->throttle_group) {
+        bdrv_io_limits_enable(medium_bs, blk_rs->throttle_group);
+    }
+
+    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,
-- 
2.6.1

[Qemu-devel] [PATCH v7 34/39] 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 eb7409c..10e4d71 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -429,18 +429,15 @@ 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);
         }
     }
 }
-- 
2.6.1

[Qemu-devel] [PATCH v7 35/39] 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 50e5e74..db789e2 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2094,8 +2094,9 @@ 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;
@@ -2119,7 +2120,7 @@ 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 a00be94..b06a060 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 702b7b5..058b8ec 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1842,8 +1842,10 @@
 #          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 16d7e2a..8643d95 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -4154,6 +4154,37 @@ Example:
 EQMP
 
     {
+        .name       = "blockdev-change-medium",
+        .args_type  = "device:B,filename:F,format:s?",
+        .mhandler.cmd_new = qmp_marshal_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_query_memdev,
diff --git a/qmp.c b/qmp.c
index ff54e5a..4e44f98 100644
--- a/qmp.c
+++ b/qmp.c
@@ -414,7 +414,7 @@ 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);
     }
 }
 
-- 
2.6.1

[Qemu-devel] [PATCH v7 36/39] 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 5048eee..b91821b 100644
--- a/hmp.c
+++ b/hmp.c
@@ -1338,22 +1338,25 @@ 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);
 }
 
-- 
2.6.1

[Qemu-devel] [PATCH v7 37/39] 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 db789e2..b79b0a6 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2096,6 +2096,8 @@ 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;
@@ -2117,7 +2119,28 @@ 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 b91821b..9e6b7e5 100644
--- a/hmp.c
+++ b/hmp.c
@@ -1348,7 +1348,7 @@ 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 8643d95..ed6f4ad 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -4155,7 +4155,7 @@ 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_blockdev_change_medium,
     },
 
@@ -4171,6 +4171,8 @@ 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:
 
@@ -4182,6 +4184,26 @@ 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 4e44f98..ddc63ea 100644
--- a/qmp.c
+++ b/qmp.c
@@ -414,7 +414,8 @@ 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);
     }
 }
 
-- 
2.6.1

[Qemu-devel] [PATCH v7 38/39] 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 3a4ae39..814ea86 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 9e6b7e5..28caa7d 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"
@@ -1336,9 +1337,16 @@ 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) {
@@ -1348,7 +1356,19 @@ 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);
-- 
2.6.1

[Qemu-devel] [PATCH v7 39/39] 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 30c784e..a6a61ae 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -122,6 +122,7 @@
 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
-- 
2.6.1

Re: [Qemu-devel] [PATCH v7 27/39] block: Add blk_remove_bs()

[Kevin Wolf]

Am 19.10.2015 um 17:53 hat Max Reitz geschrieben:
> 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>
> ---
>  block/block-backend.c          | 12 ++++++++++++
>  include/sysemu/block-backend.h |  1 +
>  2 files changed, 13 insertions(+)
> 
> diff --git a/block/block-backend.c b/block/block-backend.c
> index 19fdaae..eb7409c 100644
> --- a/block/block-backend.c
> +++ b/block/block-backend.c
> @@ -334,6 +334,18 @@ void blk_hide_on_behalf_of_hmp_drive_del(BlockBackend *blk)
>  }
>  
>  /*
> + * Disassociates the currently associated BlockDriverState from @blk.
> + */
> +void blk_remove_bs(BlockBackend *blk)
> +{
> +    blk_update_root_state(blk);
> +
> +    bdrv_unref(blk->bs);
> +    blk->bs->blk = NULL;

Use after free?

> +    blk->bs = NULL;
> +}

Kevin

Re: [Qemu-devel] [PATCH v7 00/39] blockdev: BlockBackend and media

[Kevin Wolf]

Am 19.10.2015 um 17:53 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.

Thanks, applied patches 1-26 to the block branch.

Kevin

Re: [Qemu-devel] [PATCH v7 31/39] blockdev: Add blockdev-insert-medium

[Alberto Garcia]

On Mon 19 Oct 2015 05:53:37 PM CEST, Max Reitz wrote:
> 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).

Shouldn't this update bdrv_states?

Consider this scenario:

1) We add a drive and eject its BDS
   { "execute": "blockdev-add", "arguments": {
         "options": { "driver": "qcow2",
                      "file": { "driver": "file",
                                "filename": "/tmp/hd0.img"},
                      "id": "drive0" }}}

   { "execute": "eject", "arguments": {"device": "drive0"}}

2) We create a new BDS and insert it in drive0
   { "execute": "blockdev-add", "arguments": {
         "options": { "driver": "qcow2",
                      "file": { "driver": "file",
                                "filename": "/tmp/hd0.img"},
                      "node-name": "hd0" }}}

   { "execute": "blockdev-insert-medium", "arguments": {
         "device": "drive0",
         "node-name": "hd0" }}

3) Now we try to create a snapshot...

   { "execute": "blockdev-snapshot-sync", "arguments": {
         "device": "drive0",
         "snapshot-file": "/tmp/new.img",
         "format": "qcow2" }}

   {"error": {"class": "GenericError",
              "desc": "The feature 'snapshot' is not enabled"}}

   Ooops! It seems that this is because the new node hd0 is not in the
   bdrv_states list.

4) Let's try to create a mirror instead

   { "execute": "drive-mirror", "arguments": {
         "device": "drive0",
         "target": "/tmp/new.img",
         "sync": "top"}}

   {"return": {}}
   {"timestamp": {"seconds": 1445427560,
                  "microseconds": 765993},
    "event": "BLOCK_JOB_READY",
    "data": {"device": "drive0",
             "len": 0,
             "offset": 0,
             "speed": 0,
             "type": "mirror"}}

5) Ok, the block job is ready, so let's complete it:

   { "execute": "query-block-jobs" }
   {"return": []}

   Ooops! Again, hd0 is not in bdrv_states so QEMU cannot find the block
   job.

6) Anyway, we only need the backend name in order to complete a block
   job, so surely we can do it even if it's not in the list:

   { "execute": "block-job-complete", "arguments": {
         "device": "drive0"}}

   Segmentation fault

   That's QTAILQ_INSERT_BEFORE() in change_parent_backing_link(). This
   code assumes that since the 'from' BDS is attached to a backend, it
   must also be in bdrv_states.

Berto

Re: [Qemu-devel] [PATCH v7 27/39] block: Add blk_remove_bs()

[Max Reitz]

[-- Attachment #1: Type: text/plain, Size: 1056 bytes --]

On 20.10.2015 10:33, Kevin Wolf wrote:
> Am 19.10.2015 um 17:53 hat Max Reitz geschrieben:
>> 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>
>> ---
>>  block/block-backend.c          | 12 ++++++++++++
>>  include/sysemu/block-backend.h |  1 +
>>  2 files changed, 13 insertions(+)
>>
>> diff --git a/block/block-backend.c b/block/block-backend.c
>> index 19fdaae..eb7409c 100644
>> --- a/block/block-backend.c
>> +++ b/block/block-backend.c
>> @@ -334,6 +334,18 @@ void blk_hide_on_behalf_of_hmp_drive_del(BlockBackend *blk)
>>  }
>>  
>>  /*
>> + * Disassociates the currently associated BlockDriverState from @blk.
>> + */
>> +void blk_remove_bs(BlockBackend *blk)
>> +{
>> +    blk_update_root_state(blk);
>> +
>> +    bdrv_unref(blk->bs);
>> +    blk->bs->blk = NULL;
> 
> Use after free?

Yes, indeed, will fix.

Max

>> +    blk->bs = NULL;
>> +}
> 
> Kevin
> 



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Re: [Qemu-devel] [PATCH v7 31/39] blockdev: Add blockdev-insert-medium

[Max Reitz]

[-- Attachment #1: Type: text/plain, Size: 2864 bytes --]

On 21.10.2015 13:49, Alberto Garcia wrote:
> On Mon 19 Oct 2015 05:53:37 PM CEST, Max Reitz wrote:
>> 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).
> 
> Shouldn't this update bdrv_states?

I hate bdrv_states.

Yes, it should. Thanks!

Max

> Consider this scenario:
> 
> 1) We add a drive and eject its BDS
>    { "execute": "blockdev-add", "arguments": {
>          "options": { "driver": "qcow2",
>                       "file": { "driver": "file",
>                                 "filename": "/tmp/hd0.img"},
>                       "id": "drive0" }}}
> 
>    { "execute": "eject", "arguments": {"device": "drive0"}}
> 
> 2) We create a new BDS and insert it in drive0
>    { "execute": "blockdev-add", "arguments": {
>          "options": { "driver": "qcow2",
>                       "file": { "driver": "file",
>                                 "filename": "/tmp/hd0.img"},
>                       "node-name": "hd0" }}}
> 
>    { "execute": "blockdev-insert-medium", "arguments": {
>          "device": "drive0",
>          "node-name": "hd0" }}
> 
> 3) Now we try to create a snapshot...
> 
>    { "execute": "blockdev-snapshot-sync", "arguments": {
>          "device": "drive0",
>          "snapshot-file": "/tmp/new.img",
>          "format": "qcow2" }}
> 
>    {"error": {"class": "GenericError",
>               "desc": "The feature 'snapshot' is not enabled"}}
> 
>    Ooops! It seems that this is because the new node hd0 is not in the
>    bdrv_states list.
> 
> 4) Let's try to create a mirror instead
> 
>    { "execute": "drive-mirror", "arguments": {
>          "device": "drive0",
>          "target": "/tmp/new.img",
>          "sync": "top"}}
> 
>    {"return": {}}
>    {"timestamp": {"seconds": 1445427560,
>                   "microseconds": 765993},
>     "event": "BLOCK_JOB_READY",
>     "data": {"device": "drive0",
>              "len": 0,
>              "offset": 0,
>              "speed": 0,
>              "type": "mirror"}}
> 
> 5) Ok, the block job is ready, so let's complete it:
> 
>    { "execute": "query-block-jobs" }
>    {"return": []}
> 
>    Ooops! Again, hd0 is not in bdrv_states so QEMU cannot find the block
>    job.
> 
> 6) Anyway, we only need the backend name in order to complete a block
>    job, so surely we can do it even if it's not in the list:
> 
>    { "execute": "block-job-complete", "arguments": {
>          "device": "drive0"}}
> 
>    Segmentation fault
> 
>    That's QTAILQ_INSERT_BEFORE() in change_parent_backing_link(). This
>    code assumes that since the 'from' BDS is attached to a backend, it
>    must also be in bdrv_states.
> 
> Berto
> 



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Re: [Qemu-devel] [PATCH v7 28/39] blockdev: Add blockdev-open-tray

[Kevin Wolf]

Am 19.10.2015 um 17:53 hat Max Reitz geschrieben:
> 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(+)

> +
> +    if (blk_dev_is_medium_locked(blk)) {
> +        blk_dev_eject_request(blk, force);
> +    } else {
> +        blk_dev_change_media_cb(blk, false);
> +    }

This seems to be inconsistent with the command documentation: In the
case of a forced eject request, the tray is just unlocked, but not
opened.

> +##
> +# @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' } }

This API makes it impossible for the management application to know
whether the tray has actually been opened or just an eject request has
been made.

Is the expected use that management sets a timeout and waits for a
tray opened event? If so, worth documenting?

Kevin

Re: [Qemu-devel] [PATCH v7 28/39] blockdev: Add blockdev-open-tray

[Kevin Wolf]

Am 19.10.2015 um 17:53 hat Max Reitz geschrieben:
> 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(+)

> +    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;
> +        }

Is this blocker really for protecting against opening the tray? I think
the BDS shouldn't care about whether the guest can access it. So it's
probably more about preventing a bdrv_close() from happening, i.e. it
would be relevant only for the blockdev-remove-medium command.

Kevin

Re: [Qemu-devel] [PATCH v7 31/39] blockdev: Add blockdev-insert-medium

[Kevin Wolf]

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Am 21.10.2015 um 15:47 hat Max Reitz geschrieben:
> On 21.10.2015 13:49, Alberto Garcia wrote:
> > On Mon 19 Oct 2015 05:53:37 PM CEST, Max Reitz wrote:
> >> 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).
> > 
> > Shouldn't this update bdrv_states?
> 
> I hate bdrv_states.
> 
> Yes, it should. Thanks!

Once your reimplement blk_set_bs() on top of blk_insert/remove_bs(),
this logic would replace the code in change_parent_backing_link().

Of course, I left the list update in block.c for a reason, it's meant to
be an internal data structure, so your code accessing it from outside
won't be much nicer. Do we actually still need bdrv_states or can we get
rid of it in a follow-up series? If so, I wouldn't mind an ugly
intermediate state.

Kevin

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Re: [Qemu-devel] [PATCH v7 31/39] blockdev: Add blockdev-insert-medium

[Kevin Wolf]

Am 19.10.2015 um 17:53 hat Max Reitz geschrieben:
> 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           | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>  qapi/block-core.json | 17 +++++++++++++++++
>  qmp-commands.hx      | 37 +++++++++++++++++++++++++++++++++++
>  3 files changed, 108 insertions(+)
> 
> diff --git a/blockdev.c b/blockdev.c
> index a8601ca..a4c278f 100644
> --- a/blockdev.c
> +++ b/blockdev.c
> @@ -2151,6 +2151,60 @@ 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);

Shouldn't this use bdrv_lookup_bs() to accept a BB name and be consisent
with most other commands? Of course, if you actually used a BB name, it
would fail below, but not with a confusing "not found" message.

> +    if (!bs) {
> +        error_setg(errp, "Node '%s' not found", node_name);
> +        return;
> +    }
> +
> +    if (bs->blk) {
> +        error_setg(errp, "Node '%s' is already in use by '%s'", node_name,
> +                   blk_name(bs->blk));
> +        return;
> +    }
> +
> +    qmp_blockdev_insert_anon_medium(device, bs, errp);
> +}

Kevin

Re: [Qemu-devel] [PATCH v7 29/39] blockdev: Add blockdev-close-tray

[Kevin Wolf]

Am 19.10.2015 um 17:53 hat Max Reitz geschrieben:
> Signed-off-by: Max Reitz <mreitz@redhat.com>

Reviewed-by: Kevin Wolf <kwolf@redhat.com>

Re: [Qemu-devel] [PATCH v7 30/39] blockdev: Add blockdev-remove-medium

[Kevin Wolf]

Am 19.10.2015 um 17:53 hat Max Reitz geschrieben:
> Signed-off-by: Max Reitz <mreitz@redhat.com>

I assume that you'll fix the bdrv_states issues in blk_insert/remove_bs,
so the blk_remove_bs() call in this patch will take care of it.

If so, you can add:
Reviewed-by: Kevin Wolf <kwolf@redhat.com>

Re: [Qemu-devel] [PATCH v7 32/39] blockdev: Implement eject with basic operations

[Kevin Wolf]

Am 19.10.2015 um 17:53 hat Max Reitz geschrieben:
> 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 a4c278f..0481686 100644
> --- a/blockdev.c
> +++ b/blockdev.c
> @@ -1941,16 +1941,15 @@ 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;
>      }

This changes the behaviour, in the current patch series in two ways if
the device is locked:

1. With force, the qmp_blockdev_remove_medium() call will fail because
   we only unlocked the device, but didn't actually open the tray (I
   commented on this in the qmp_blockdev_open_tray() patch). This breaks
   the API, obviously.

2. Without force, eject previously sent an eject request and also
   returned a "Device is locked" error. Now it fails with "Tray of
   device is not open". Regression in the message quality, but not an
   API breakage because tools must not parse the message.

> -    eject_device(blk, force, errp);
> +    qmp_blockdev_remove_medium(device, errp);
>  }

Kevin

Re: [Qemu-devel] [PATCH v7 31/39] blockdev: Add blockdev-insert-medium

[Max Reitz]

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On 23.10.2015 15:39, Kevin Wolf wrote:
> Am 21.10.2015 um 15:47 hat Max Reitz geschrieben:
>> On 21.10.2015 13:49, Alberto Garcia wrote:
>>> On Mon 19 Oct 2015 05:53:37 PM CEST, Max Reitz wrote:
>>>> 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).
>>>
>>> Shouldn't this update bdrv_states?
>>
>> I hate bdrv_states.
>>
>> Yes, it should. Thanks!
> 
> Once your reimplement blk_set_bs() on top of blk_insert/remove_bs(),
> this logic would replace the code in change_parent_backing_link().
> 
> Of course, I left the list update in block.c for a reason, it's meant to
> be an internal data structure, so your code accessing it from outside
> won't be much nicer. Do we actually still need bdrv_states or can we get
> rid of it in a follow-up series? If so, I wouldn't mind an ugly
> intermediate state.

I do get rid of it in "blockdev: Further BlockBackend work"* (the final
patch of that series).

Max


* http://lists.nongnu.org/archive/html/qemu-block/2015-02/msg00021.html


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Re: [Qemu-devel] [PATCH v7 33/39] blockdev: Implement change with basic operations

[Kevin Wolf]

Am 19.10.2015 um 17:53 hat Max Reitz geschrieben:
> 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 | 184 +++++++++++++++++++++++++------------------------------------
>  1 file changed, 74 insertions(+), 110 deletions(-)
> 
> diff --git a/blockdev.c b/blockdev.c
> index 0481686..50e5e74 100644
> --- a/blockdev.c
> +++ b/blockdev.c
> @@ -1901,44 +1901,6 @@ exit:
>      }
>  }
>  
> -
> -static void eject_device(BlockBackend *blk, int force, Error **errp)
> -{
> -    BlockDriverState *bs = blk_bs(blk);
> -    AioContext *aio_context;
> -
> -    if (!bs) {
> -        /* No medium inserted, so there is nothing to do */
> -        return;
> -    }
> -
> -    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_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;
> -        }
> -    }
> -
> -    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;
> @@ -1976,78 +1938,6 @@ 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)
> -{
> -    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;
> -    }
> -
> -    bdrv_add_key(*pbs, 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);
> -        goto out;
> -    }
> -
> -    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)
>  {
> @@ -2204,6 +2094,80 @@ 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->throttle_group) {
> +        bdrv_io_limits_enable(medium_bs, blk_rs->throttle_group);
> +    }

Would it make sense to have a blk_apply_root_state() that does these
updates? Otherwise you have to keep this place up to date if the struct
is ever extended. (Which would mean that we forgot something, so
hopefully not.)

Kevin

Re: [Qemu-devel] [PATCH v7 34/39] block: Inquire tray state before tray-moved events

[Kevin Wolf]

Am 19.10.2015 um 17:53 hat Max Reitz geschrieben:
> 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>

Reviewed-by: Kevin Wolf <kwolf@redhat.com>

Re: [Qemu-devel] [PATCH v7 28/39] blockdev: Add blockdev-open-tray

[Max Reitz]

[-- Attachment #1: Type: text/plain, Size: 3450 bytes --]

On 23.10.2015 15:22, Kevin Wolf wrote:
> Am 19.10.2015 um 17:53 hat Max Reitz geschrieben:
>> 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(+)
> 
>> +
>> +    if (blk_dev_is_medium_locked(blk)) {
>> +        blk_dev_eject_request(blk, force);
>> +    } else {
>> +        blk_dev_change_media_cb(blk, false);
>> +    }
> 
> This seems to be inconsistent with the command documentation: In the
> case of a forced eject request, the tray is just unlocked, but not
> opened.

OK. I assumed that since the guest would be expected to open the tray by
itself if @force was false, the emulated device would do the same if
@force was true.

So I'll call blk_dev_change_media_cb() after blk_dev_eject_request(),
too, if @force is true.

>> +##
>> +# @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' } }
> 
> This API makes it impossible for the management application to know
> whether the tray has actually been opened or just an eject request has
> been made.

Yes, and I faintly remember having asked you and Markus on your opinion
on this topic in last December. A related question I was even more
concerned about was "If the tray is locked and an eject request has been
sent, the eject issued by the guest may do something different than
blockdev-open-tray would have done with an unlocked tray", with the
issue being that the management application cannot prevent
blockdev-open-tray from sending the unlock request.

I considered actually making blockdev-open-tray and this
"send-eject-request" two different commands, so that blockdev-open-tray
would never send an eject request and just return an error if the tray
is locked. As far as I remember, you (both?) convinced me to keep it a
single command which would do what "pressing the button on a physical CD
drive does".

So I did that, and thus it's the same. Just when pressing that button,
after sending this command you'll have to wait until the tray is open
and you won't know whether the OS actually has any intention of doing so
until you've waited for too long.

> Is the expected use that management sets a timeout and waits for a
> tray opened event? If so, worth documenting?

That's probably what management software should do, yes, just like it is
with the "eject" command right now. I considered the "the tray will not
be opened immediately" enough, but feel free to tell me it is not.

Max


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Re: [Qemu-devel] [PATCH v7 35/39] qmp: Introduce blockdev-change-medium

[Kevin Wolf]

Am 19.10.2015 um 17:53 hat Max Reitz geschrieben:
> 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-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' } }

Do we really want to expose such an interface in a new QMP command? It
isn't like blockdev-add, but like -hda. Which doesn't only mean that you
can't specify most options, but also that filename is parsed for
protocol names etc.

Shouldn't new clients use blockdev-add and the separate tray-open/close
and remove/insert-medium commands instead of converting from one bad
commannd (change) to another (this one)?

Or, if we really want to provide a convenience function, this should
probably take a BlockdevRef instead of filename/format.

Kevin

Re: [Qemu-devel] [PATCH v7 28/39] blockdev: Add blockdev-open-tray

[Max Reitz]

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On 23.10.2015 15:26, Kevin Wolf wrote:
> Am 19.10.2015 um 17:53 hat Max Reitz geschrieben:
>> 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(+)
> 
>> +    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;
>> +        }
> 
> Is this blocker really for protecting against opening the tray? I think
> the BDS shouldn't care about whether the guest can access it. So it's
> probably more about preventing a bdrv_close() from happening, i.e. it
> would be relevant only for the blockdev-remove-medium command.

I don't think so. I intended blockdev-open-tray to be what it is for
real hardware: Opening the tray severs all the links between the medium
and software trying to access the drive. blockdev-remove-medium should
never fail if the tray is already open, since it would never fail in
real life.

By the way, that's the reason why I generally preferred
blk_is_available() over blk_is_inserted() in this series.

Max


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Re: [Qemu-devel] [PATCH v7 31/39] blockdev: Add blockdev-insert-medium

[Max Reitz]

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On 23.10.2015 15:42, Kevin Wolf wrote:
> Am 19.10.2015 um 17:53 hat Max Reitz geschrieben:
>> 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           | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>>  qapi/block-core.json | 17 +++++++++++++++++
>>  qmp-commands.hx      | 37 +++++++++++++++++++++++++++++++++++
>>  3 files changed, 108 insertions(+)
>>
>> diff --git a/blockdev.c b/blockdev.c
>> index a8601ca..a4c278f 100644
>> --- a/blockdev.c
>> +++ b/blockdev.c
>> @@ -2151,6 +2151,60 @@ 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);
> 
> Shouldn't this use bdrv_lookup_bs() to accept a BB name and be consisent
> with most other commands? Of course, if you actually used a BB name, it
> would fail below, but not with a confusing "not found" message.

Well, and then it fails with "Node 'foo' is already in use by 'foo'",
which doesn't make much more sense either.

Until we support multiple BBs per BDS, using this command with a BB
doesn't make any sense. I may be wrong here or exaggerating, but I feel
like most of the "most other commands" allow that mostly because of
legacy reasons. Second, most of them are block jobs which I feel like
should work behind a BB anyway, and letting them work on a BDS is wrong,
but we just haven't converted them yet.

I don't have a strong preference. I find the error messages equally bad.
But I think I don't want to use bdrv_lookup_bs() since that would look
like pretending that we actually do want to support BB names, whereas in
reality we absolutely don't (not right now at least).

Also, it would confuse me when reading the code: "Why are you accepting
a BB name up there, and then you are rejecting every BDS that has a BB?
That doesn't make sense!"

Improving the error message doesn't seem to good to me either. It would
have to be something like "'%s' is a device, not a node" which I don't
consider much more helpful either (maybe it is, I don't know), and
adding an explanation like "; blockdev-insert-medium only accepts node
names" would feel like a bit too much since we don't do that anywhere
else, do we?

Max

>> +    if (!bs) {
>> +        error_setg(errp, "Node '%s' not found", node_name);
>> +        return;
>> +    }
>> +
>> +    if (bs->blk) {
>> +        error_setg(errp, "Node '%s' is already in use by '%s'", node_name,
>> +                   blk_name(bs->blk));
>> +        return;
>> +    }
>> +
>> +    qmp_blockdev_insert_anon_medium(device, bs, errp);
>> +}
> 
> Kevin
> 



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Re: [Qemu-devel] [PATCH v7 32/39] blockdev: Implement eject with basic operations

[Max Reitz]

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On 23.10.2015 15:54, Kevin Wolf wrote:
> Am 19.10.2015 um 17:53 hat Max Reitz geschrieben:
>> 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 a4c278f..0481686 100644
>> --- a/blockdev.c
>> +++ b/blockdev.c
>> @@ -1941,16 +1941,15 @@ 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;
>>      }
> 
> This changes the behaviour, in the current patch series in two ways if
> the device is locked:
> 
> 1. With force, the qmp_blockdev_remove_medium() call will fail because
>    we only unlocked the device, but didn't actually open the tray (I
>    commented on this in the qmp_blockdev_open_tray() patch). This breaks
>    the API, obviously.

Yep, will fix.

> 2. Without force, eject previously sent an eject request and also
>    returned a "Device is locked" error. Now it fails with "Tray of
>    device is not open". Regression in the message quality, but not an
>    API breakage because tools must not parse the message.

I think this should be fine. The previous message wasn't too good in my
opinion either, because the most likely scenario is this: User issues
eject, management tool reports qemu's message: "Device is locked!" and
then the tray opens. So that's strange, too. Maybe "Tray of device is
not open" is actually the better message here, I don't know. It better
describes the state, but it does not describe the reason...

But in addition to that, there is no easy way around this. I could put a
check into qmp_eject() which returns a "Device is locked" message if the
tray is still closed after a successful qmp_blockdev_open_tray(), but I
don't know whether that's worth it.

Max

>> -    eject_device(blk, force, errp);
>> +    qmp_blockdev_remove_medium(device, errp);
>>  }
> 
> Kevin
> 



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Re: [Qemu-devel] [PATCH v7 33/39] blockdev: Implement change with basic operations

[Max Reitz]

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On 23.10.2015 16:11, Kevin Wolf wrote:
> Am 19.10.2015 um 17:53 hat Max Reitz geschrieben:
>> 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 | 184 +++++++++++++++++++++++++------------------------------------
>>  1 file changed, 74 insertions(+), 110 deletions(-)
>>
>> diff --git a/blockdev.c b/blockdev.c
>> index 0481686..50e5e74 100644
>> --- a/blockdev.c
>> +++ b/blockdev.c
>> @@ -1901,44 +1901,6 @@ exit:
>>      }
>>  }
>>  
>> -
>> -static void eject_device(BlockBackend *blk, int force, Error **errp)
>> -{
>> -    BlockDriverState *bs = blk_bs(blk);
>> -    AioContext *aio_context;
>> -
>> -    if (!bs) {
>> -        /* No medium inserted, so there is nothing to do */
>> -        return;
>> -    }
>> -
>> -    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_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;
>> -        }
>> -    }
>> -
>> -    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;
>> @@ -1976,78 +1938,6 @@ 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)
>> -{
>> -    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;
>> -    }
>> -
>> -    bdrv_add_key(*pbs, 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);
>> -        goto out;
>> -    }
>> -
>> -    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)
>>  {
>> @@ -2204,6 +2094,80 @@ 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->throttle_group) {
>> +        bdrv_io_limits_enable(medium_bs, blk_rs->throttle_group);
>> +    }
> 
> Would it make sense to have a blk_apply_root_state() that does these
> updates? Otherwise you have to keep this place up to date if the struct
> is ever extended. (Which would mean that we forgot something, so
> hopefully not.)

Makes sense. I'll probably write one with an annotation that it's only
to be used by this function.

Max


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Re: [Qemu-devel] [PATCH v7 28/39] blockdev: Add blockdev-open-tray

[Kevin Wolf]

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Am 23.10.2015 um 16:26 hat Max Reitz geschrieben:
> On 23.10.2015 15:26, Kevin Wolf wrote:
> > Am 19.10.2015 um 17:53 hat Max Reitz geschrieben:
> >> 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(+)
> > 
> >> +    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;
> >> +        }
> > 
> > Is this blocker really for protecting against opening the tray? I think
> > the BDS shouldn't care about whether the guest can access it. So it's
> > probably more about preventing a bdrv_close() from happening, i.e. it
> > would be relevant only for the blockdev-remove-medium command.
> 
> I don't think so. I intended blockdev-open-tray to be what it is for
> real hardware: Opening the tray severs all the links between the medium
> and software trying to access the drive. blockdev-remove-medium should
> never fail if the tray is already open, since it would never fail in
> real life.

Comparison with real hardware works only so far. Real hardware doesn't
have block jobs and will therefore never set the eject blocker.

As I said, though, it's mostly protecting against bdrv_close(). Now that
we don't call that any more, we don't strictly need the blocker any
more in order to keep block jobs happy.

However, we still need to prevent that the connection between BB and BDS
is severed in case the old BDS was created implicitly and therefore
would disappear from query-block while the image is still open and in
use, which we don't want. This touches blockdev-del land more than op
blockers, though... I think the eject op blocker can go.

With your check, you prevent the user from opening the tray using QMP
and then they can't get into a bad state with blockdev-remove-medium
because without an opened tray that would fail. However, they could
still eject the medium from within the guest and then use
blockdev-remove-medium, which will get them in the bad state that we
wanted to prevent.

> By the way, that's the reason why I generally preferred
> blk_is_available() over blk_is_inserted() in this series.

I actually think this use is too restrictive in many cases (and in this
patch opening the tray is pointlessly forbidden), but I didn't comment
on it because we can fix it whenever someone needs more.

Kevin

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Re: [Qemu-devel] [PATCH v7 31/39] blockdev: Add blockdev-insert-medium

[Kevin Wolf]

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Am 23.10.2015 um 16:35 hat Max Reitz geschrieben:
> On 23.10.2015 15:42, Kevin Wolf wrote:
> > Am 19.10.2015 um 17:53 hat Max Reitz geschrieben:
> >> 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           | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++
> >>  qapi/block-core.json | 17 +++++++++++++++++
> >>  qmp-commands.hx      | 37 +++++++++++++++++++++++++++++++++++
> >>  3 files changed, 108 insertions(+)
> >>
> >> diff --git a/blockdev.c b/blockdev.c
> >> index a8601ca..a4c278f 100644
> >> --- a/blockdev.c
> >> +++ b/blockdev.c
> >> @@ -2151,6 +2151,60 @@ 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);
> > 
> > Shouldn't this use bdrv_lookup_bs() to accept a BB name and be consisent
> > with most other commands? Of course, if you actually used a BB name, it
> > would fail below, but not with a confusing "not found" message.
> 
> Well, and then it fails with "Node 'foo' is already in use by 'foo'",
> which doesn't make much more sense either.
> 
> Until we support multiple BBs per BDS, using this command with a BB
> doesn't make any sense.

Correct, this would be mostly in preparation for supporting multiple BBs
per BDS.

> I may be wrong here or exaggerating, but I feel
> like most of the "most other commands" allow that mostly because of
> legacy reasons. Second, most of them are block jobs which I feel like
> should work behind a BB anyway, and letting them work on a BDS is wrong,
> but we just haven't converted them yet.
> 
> I don't have a strong preference. I find the error messages equally bad.
> But I think I don't want to use bdrv_lookup_bs() since that would look
> like pretending that we actually do want to support BB names, whereas in
> reality we absolutely don't (not right now at least).
> 
> Also, it would confuse me when reading the code: "Why are you accepting
> a BB name up there, and then you are rejecting every BDS that has a BB?
> That doesn't make sense!"
> 
> Improving the error message doesn't seem to good to me either. It would
> have to be something like "'%s' is a device, not a node" which I don't
> consider much more helpful either (maybe it is, I don't know), and
> adding an explanation like "; blockdev-insert-medium only accepts node
> names" would feel like a bit too much since we don't do that anywhere
> else, do we?

Fair enough. It's your code, you decide.

Kevin

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Re: [Qemu-devel] [PATCH v7 35/39] qmp: Introduce blockdev-change-medium

[Max Reitz]

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On 23.10.2015 16:25, Kevin Wolf wrote:
> Am 19.10.2015 um 17:53 hat Max Reitz geschrieben:
>> 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-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' } }
> 
> Do we really want to expose such an interface in a new QMP command? It
> isn't like blockdev-add, but like -hda. Which doesn't only mean that you
> can't specify most options, but also that filename is parsed for
> protocol names etc.

Let's go back to why this series exists.

Once upon a time, in the magical land of a certain IRC channel, there
was someone who wanted "change" to be able to change the R/W mode of the
medium.

The first iteration of the ensuing series had three patches and did just
that. Alas, however! some people were discontent. "change" is in a
horrible state, they said, Please separate the blockdev operation from
the VNC operation, they said.

And so the second iteration came around which added this here function,
blockdev-change-medium. Now that's much better!, they said. Alas! It was
not enough. Since you are already touching this, why don't you clean up
everything?, they asked.

And so the third iteration came into being, henceforth known as
"blockdev: BlockBackend and media" and re-numerated as v1, since it was
1250 % the size of the last version.

blockdev-change-medium, however, stayed. This is because change is such
an ugly beast that nobody should ever use it again, but the four new
atomic commands are too frightening for human users.

Oh, and it's also for the fact that this function pretty much exists
already and just isn't exposed to the outside yet.

And so this series has to this date been living happily ever after.


In short: It's been in this series since v0. A note next to "change"
tells people not to use it, but without this function here they have to
use it if they don't want to mess with the atomic commands. With this
function added, we can finally tell people *never* to use "change". So
that may be considered progress.

> Shouldn't new clients use blockdev-add and the separate tray-open/close
> and remove/insert-medium commands instead of converting from one bad
> commannd (change) to another (this one)?

Clients, yes, humans, no.

(Although I'll happily accept the obvious argument: Rarely any human
will ever use blockdev-change-medium over change. But at least we can
then tell them that it's simply wrong.)

> Or, if we really want to provide a convenience function, this should
> probably take a BlockdevRef instead of filename/format.

We want a change-like convenience function, i.e. one that takes a
filename. Just combining open-tray + remove-medium + insert-medium +
close-tray into a single command doesn't sound like too much convenience
to me. Creating the BDS is much more work than issuing all of these four
commands.

So I don't know whether to drop it. If I drop this function, we still
cannot fully deprecate change. Also, this function pretty much offers
itself, this patch changes only very little code.

I do see the "Do you really want to introduce a function that is going
to be legacy right from the start?" argument. But then again, we'll have
to support change anyway, so I don't think this will cost us anything.

I don't know.

Max


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Re: [Qemu-devel] [PATCH v7 28/39] blockdev: Add blockdev-open-tray

[Max Reitz]

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On 23.10.2015 16:45, Kevin Wolf wrote:
> Am 23.10.2015 um 16:26 hat Max Reitz geschrieben:
>> On 23.10.2015 15:26, Kevin Wolf wrote:
>>> Am 19.10.2015 um 17:53 hat Max Reitz geschrieben:
>>>> 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(+)
>>>
>>>> +    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;
>>>> +        }
>>>
>>> Is this blocker really for protecting against opening the tray? I think
>>> the BDS shouldn't care about whether the guest can access it. So it's
>>> probably more about preventing a bdrv_close() from happening, i.e. it
>>> would be relevant only for the blockdev-remove-medium command.
>>
>> I don't think so. I intended blockdev-open-tray to be what it is for
>> real hardware: Opening the tray severs all the links between the medium
>> and software trying to access the drive. blockdev-remove-medium should
>> never fail if the tray is already open, since it would never fail in
>> real life.
> 
> Comparison with real hardware works only so far. Real hardware doesn't
> have block jobs and will therefore never set the eject blocker.

It does have software accessing the disk and will therefore lock the tray.

> As I said, though, it's mostly protecting against bdrv_close(). Now that
> we don't call that any more, we don't strictly need the blocker any
> more in order to keep block jobs happy.
> 
> However, we still need to prevent that the connection between BB and BDS
> is severed in case the old BDS was created implicitly and therefore
> would disappear from query-block while the image is still open and in
> use, which we don't want. This touches blockdev-del land more than op
> blockers, though... I think the eject op blocker can go.

OK, so the thing is that block jobs don't use the BB but generally
access the BDS directly. Therefore, they don't care whether the BDS is
still accessible from some guest device/BB.

I'm fine with removing the eject op blocker, but I think you'll
understand if I'd rather not make it part of this series.

> With your check, you prevent the user from opening the tray using QMP
> and then they can't get into a bad state with blockdev-remove-medium
> because without an opened tray that would fail. However, they could
> still eject the medium from within the guest and then use
> blockdev-remove-medium, which will get them in the bad state that we
> wanted to prevent.

Well, the logical conclusion from this and the above simply is "remove
that op blocker". The block job shouldn't care about some guest device
behind some BB opening its tray; so consequently it shouldn't care about
the BDS being removed from that BB either.

Oh, but there is a case where the block job should care: If you've
specified the name of that BB when creating the block job. To me, that
implies that the job should run through that BB and the related guest
device may not open its tray.

Anyway, that's definitely outside of this series's realm. I guess I'll
move the check to qmp_blockdev_remove_medium(), as you suggested.

>> By the way, that's the reason why I generally preferred
>> blk_is_available() over blk_is_inserted() in this series.
> 
> I actually think this use is too restrictive in many cases (and in this
> patch opening the tray is pointlessly forbidden), but I didn't comment
> on it because we can fix it whenever someone needs more.

My opinion still is that if you're accessing a BDS tree through a BB
which is attached to a guest device, you should assume the guest
device's view on the BDS tree, that is, if the device's tray is open,
you won't get any data.

Max


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Re: [Qemu-devel] [PATCH v7 28/39] blockdev: Add blockdev-open-tray

[Kevin Wolf]

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Am 23.10.2015 um 17:25 hat Max Reitz geschrieben:
> On 23.10.2015 16:45, Kevin Wolf wrote:
> > Am 23.10.2015 um 16:26 hat Max Reitz geschrieben:
> >> On 23.10.2015 15:26, Kevin Wolf wrote:
> >>> Am 19.10.2015 um 17:53 hat Max Reitz geschrieben:
> >>>> 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(+)
> >>>
> >>>> +    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;
> >>>> +        }
> >>>
> >>> Is this blocker really for protecting against opening the tray? I think
> >>> the BDS shouldn't care about whether the guest can access it. So it's
> >>> probably more about preventing a bdrv_close() from happening, i.e. it
> >>> would be relevant only for the blockdev-remove-medium command.
> >>
> >> I don't think so. I intended blockdev-open-tray to be what it is for
> >> real hardware: Opening the tray severs all the links between the medium
> >> and software trying to access the drive. blockdev-remove-medium should
> >> never fail if the tray is already open, since it would never fail in
> >> real life.
> > 
> > Comparison with real hardware works only so far. Real hardware doesn't
> > have block jobs and will therefore never set the eject blocker.
> 
> It does have software accessing the disk and will therefore lock the tray.

That's an entirely different matter and checked by the
blk_dev_is_medium_locked() call below.

> > As I said, though, it's mostly protecting against bdrv_close(). Now that
> > we don't call that any more, we don't strictly need the blocker any
> > more in order to keep block jobs happy.
> > 
> > However, we still need to prevent that the connection between BB and BDS
> > is severed in case the old BDS was created implicitly and therefore
> > would disappear from query-block while the image is still open and in
> > use, which we don't want. This touches blockdev-del land more than op
> > blockers, though... I think the eject op blocker can go.
> 
> OK, so the thing is that block jobs don't use the BB but generally
> access the BDS directly. Therefore, they don't care whether the BDS is
> still accessible from some guest device/BB.
> 
> I'm fine with removing the eject op blocker, but I think you'll
> understand if I'd rather not make it part of this series.

Fine with me.

> > With your check, you prevent the user from opening the tray using QMP
> > and then they can't get into a bad state with blockdev-remove-medium
> > because without an opened tray that would fail. However, they could
> > still eject the medium from within the guest and then use
> > blockdev-remove-medium, which will get them in the bad state that we
> > wanted to prevent.
> 
> Well, the logical conclusion from this and the above simply is "remove
> that op blocker". The block job shouldn't care about some guest device
> behind some BB opening its tray; so consequently it shouldn't care about
> the BDS being removed from that BB either.

Yes, the block job shouldn't care.

As I said above, though, there's an another principle at danger: That
the monitor reference is always the last one that is dropped, so that
all open image files have a corresponding query-block entry.

> Oh, but there is a case where the block job should care: If you've
> specified the name of that BB when creating the block job. To me, that
> implies that the job should run through that BB and the related guest
> device may not open its tray.

I'm not sure about that. I think in most cases the BB name is just used
as an alias for its root node.

And of course, it has nothing to do with the guest device tray. A block
job can go through the BB even though the guest tray is open. The tray
isn't a BB concept, but a device emulation one.

> Anyway, that's definitely outside of this series's realm. I guess I'll
> move the check to qmp_blockdev_remove_medium(), as you suggested.

That should solve the problems.

> >> By the way, that's the reason why I generally preferred
> >> blk_is_available() over blk_is_inserted() in this series.
> > 
> > I actually think this use is too restrictive in many cases (and in this
> > patch opening the tray is pointlessly forbidden), but I didn't comment
> > on it because we can fix it whenever someone needs more.
> 
> My opinion still is that if you're accessing a BDS tree through a BB
> which is attached to a guest device, you should assume the guest
> device's view on the BDS tree, that is, if the device's tray is open,
> you won't get any data.

Currently the check whether the tray is open is done in the device code,
not in the BB. In the few cases where the BB needs to know the tray
status, it needs to call into the device.

And well, in theory I would very much prefer if the (qemu) user didn't
create BBs manually, but they would just be created and deleted as part
of the (BB) user (i.e. the guest device in this case).

But I'm doubtful if such a change can be implemented compatibly.

Kevin

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Re: [Qemu-devel] [PATCH v7 38/39] hmp: Add read-only-mode option to change command

[Kevin Wolf]

Am 19.10.2015 um 17:53 hat Max Reitz geschrieben:
> 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>

> @@ -1336,9 +1337,16 @@ 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");

Missing \n.

> +            return;
> +        }
>          if (strcmp(target, "passwd") == 0 ||
>              strcmp(target, "password") == 0) {
>              if (!arg) {

With that fixed:
Reviewed-by: Kevin Wolf <kwolf@redhat.com>

Re: [Qemu-devel] [PATCH v7 36/39] hmp: Use blockdev-change-medium for change command

[Kevin Wolf]

Am 19.10.2015 um 17:53 hat Max Reitz geschrieben:
> 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>

Reviewed-by: Kevin Wolf <kwolf@redhat.com>

Re: [Qemu-devel] [PATCH v7 37/39] blockdev: read-only-mode for blockdev-change-medium

[Kevin Wolf]

Am 19.10.2015 um 17:53 hat Max Reitz geschrieben:
> 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>

Reviewed-by: Kevin Wolf <kwolf@redhat.com>

Re: [Qemu-devel] [PATCH v7 35/39] qmp: Introduce blockdev-change-medium

[Kevin Wolf]

Am 19.10.2015 um 17:53 hat Max Reitz geschrieben:
> 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>

Reviewed-by: Kevin Wolf <kwolf@redhat.com>

Re: [Qemu-devel] [PATCH v7 39/39] iotests: Add test for change-related QMP commands

[Kevin Wolf]

Am 19.10.2015 um 17:53 hat Max Reitz geschrieben:
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> Reviewed-by: Eric Blake <eblake@redhat.com>

Reviewed-by: Kevin Wolf <kwolf@redhat.com>