mirror of
https://github.com/qemu/qemu.git
synced 2024-12-12 05:03:42 +08:00
1084159b31
Modern way is using blockdev-add + blockdev-backup, which provides a lot more control on how target is opened. As example of drive-backup problems consider the following: User of drive-backup expects that target will be opened in the same cache and aio mode as source. Corresponding logic is in drive_backup_prepare(), where we take bs->open_flags of source. It works rather bad if source was added by blockdev-add. Assume source is qcow2 image. On blockdev-add we should specify aio and cache options for file child of qcow2 node. What happens next: drive_backup_prepare() looks at bs->open_flags of qcow2 source node. But there no BDRV_O_NOCAHE neither BDRV_O_NATIVE_AIO: BDRV_O_NOCAHE is places in bs->file->bs->open_flags, and BDRV_O_NATIVE_AIO is nowhere, as file-posix parse options and simply set s->use_linux_aio. The documentation is updated in a minimal way, so that drive-backup is noted only as a deprecated command, and blockdev-backup used in most of places. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
259 lines
7.6 KiB
Python
259 lines
7.6 KiB
Python
# -*- Mode: Python -*-
|
|
# vim: filetype=python
|
|
#
|
|
|
|
##
|
|
# = Transactions
|
|
##
|
|
|
|
{ 'include': 'block-core.json' }
|
|
|
|
##
|
|
# @Abort:
|
|
#
|
|
# This action can be used to test transaction failure.
|
|
#
|
|
# Since: 1.6
|
|
##
|
|
{ 'struct': 'Abort',
|
|
'data': { } }
|
|
|
|
##
|
|
# @ActionCompletionMode:
|
|
#
|
|
# An enumeration of Transactional completion modes.
|
|
#
|
|
# @individual: Do not attempt to cancel any other Actions if any Actions fail
|
|
# after the Transaction request succeeds. All Actions that
|
|
# can complete successfully will do so without waiting on others.
|
|
# This is the default.
|
|
#
|
|
# @grouped: If any Action fails after the Transaction succeeds, cancel all
|
|
# Actions. Actions do not complete until all Actions are ready to
|
|
# complete. May be rejected by Actions that do not support this
|
|
# completion mode.
|
|
#
|
|
# Since: 2.5
|
|
##
|
|
{ 'enum': 'ActionCompletionMode',
|
|
'data': [ 'individual', 'grouped' ] }
|
|
|
|
##
|
|
# @TransactionActionKind:
|
|
#
|
|
# @abort: Since 1.6
|
|
# @block-dirty-bitmap-add: Since 2.5
|
|
# @block-dirty-bitmap-remove: Since 4.2
|
|
# @block-dirty-bitmap-clear: Since 2.5
|
|
# @block-dirty-bitmap-enable: Since 4.0
|
|
# @block-dirty-bitmap-disable: Since 4.0
|
|
# @block-dirty-bitmap-merge: Since 4.0
|
|
# @blockdev-backup: Since 2.3
|
|
# @blockdev-snapshot: Since 2.5
|
|
# @blockdev-snapshot-internal-sync: Since 1.7
|
|
# @blockdev-snapshot-sync: since 1.1
|
|
# @drive-backup: Since 1.6
|
|
#
|
|
# Features:
|
|
# @deprecated: Member @drive-backup is deprecated. Use member
|
|
# @blockdev-backup instead.
|
|
#
|
|
# Since: 1.1
|
|
##
|
|
{ 'enum': 'TransactionActionKind',
|
|
'data': [ 'abort', 'block-dirty-bitmap-add', 'block-dirty-bitmap-remove',
|
|
'block-dirty-bitmap-clear', 'block-dirty-bitmap-enable',
|
|
'block-dirty-bitmap-disable', 'block-dirty-bitmap-merge',
|
|
'blockdev-backup', 'blockdev-snapshot',
|
|
'blockdev-snapshot-internal-sync', 'blockdev-snapshot-sync',
|
|
{ 'name': 'drive-backup', 'features': [ 'deprecated' ] } ] }
|
|
|
|
##
|
|
# @AbortWrapper:
|
|
#
|
|
# Since: 1.6
|
|
##
|
|
{ 'struct': 'AbortWrapper',
|
|
'data': { 'data': 'Abort' } }
|
|
|
|
##
|
|
# @BlockDirtyBitmapAddWrapper:
|
|
#
|
|
# Since: 2.5
|
|
##
|
|
{ 'struct': 'BlockDirtyBitmapAddWrapper',
|
|
'data': { 'data': 'BlockDirtyBitmapAdd' } }
|
|
|
|
##
|
|
# @BlockDirtyBitmapWrapper:
|
|
#
|
|
# Since: 2.5
|
|
##
|
|
{ 'struct': 'BlockDirtyBitmapWrapper',
|
|
'data': { 'data': 'BlockDirtyBitmap' } }
|
|
|
|
##
|
|
# @BlockDirtyBitmapMergeWrapper:
|
|
#
|
|
# Since: 4.0
|
|
##
|
|
{ 'struct': 'BlockDirtyBitmapMergeWrapper',
|
|
'data': { 'data': 'BlockDirtyBitmapMerge' } }
|
|
|
|
##
|
|
# @BlockdevBackupWrapper:
|
|
#
|
|
# Since: 2.3
|
|
##
|
|
{ 'struct': 'BlockdevBackupWrapper',
|
|
'data': { 'data': 'BlockdevBackup' } }
|
|
|
|
##
|
|
# @BlockdevSnapshotWrapper:
|
|
#
|
|
# Since: 2.5
|
|
##
|
|
{ 'struct': 'BlockdevSnapshotWrapper',
|
|
'data': { 'data': 'BlockdevSnapshot' } }
|
|
|
|
##
|
|
# @BlockdevSnapshotInternalWrapper:
|
|
#
|
|
# Since: 1.7
|
|
##
|
|
{ 'struct': 'BlockdevSnapshotInternalWrapper',
|
|
'data': { 'data': 'BlockdevSnapshotInternal' } }
|
|
|
|
##
|
|
# @BlockdevSnapshotSyncWrapper:
|
|
#
|
|
# Since: 1.1
|
|
##
|
|
{ 'struct': 'BlockdevSnapshotSyncWrapper',
|
|
'data': { 'data': 'BlockdevSnapshotSync' } }
|
|
|
|
##
|
|
# @DriveBackupWrapper:
|
|
#
|
|
# Since: 1.6
|
|
##
|
|
{ 'struct': 'DriveBackupWrapper',
|
|
'data': { 'data': 'DriveBackup' } }
|
|
|
|
##
|
|
# @TransactionAction:
|
|
#
|
|
# A discriminated record of operations that can be performed with
|
|
# @transaction.
|
|
#
|
|
# Since: 1.1
|
|
##
|
|
{ 'union': 'TransactionAction',
|
|
'base': { 'type': 'TransactionActionKind' },
|
|
'discriminator': 'type',
|
|
'data': {
|
|
'abort': 'AbortWrapper',
|
|
'block-dirty-bitmap-add': 'BlockDirtyBitmapAddWrapper',
|
|
'block-dirty-bitmap-remove': 'BlockDirtyBitmapWrapper',
|
|
'block-dirty-bitmap-clear': 'BlockDirtyBitmapWrapper',
|
|
'block-dirty-bitmap-enable': 'BlockDirtyBitmapWrapper',
|
|
'block-dirty-bitmap-disable': 'BlockDirtyBitmapWrapper',
|
|
'block-dirty-bitmap-merge': 'BlockDirtyBitmapMergeWrapper',
|
|
'blockdev-backup': 'BlockdevBackupWrapper',
|
|
'blockdev-snapshot': 'BlockdevSnapshotWrapper',
|
|
'blockdev-snapshot-internal-sync': 'BlockdevSnapshotInternalWrapper',
|
|
'blockdev-snapshot-sync': 'BlockdevSnapshotSyncWrapper',
|
|
'drive-backup': 'DriveBackupWrapper'
|
|
} }
|
|
|
|
##
|
|
# @TransactionProperties:
|
|
#
|
|
# Optional arguments to modify the behavior of a Transaction.
|
|
#
|
|
# @completion-mode: Controls how jobs launched asynchronously by
|
|
# Actions will complete or fail as a group.
|
|
# See @ActionCompletionMode for details.
|
|
#
|
|
# Since: 2.5
|
|
##
|
|
{ 'struct': 'TransactionProperties',
|
|
'data': {
|
|
'*completion-mode': 'ActionCompletionMode'
|
|
}
|
|
}
|
|
|
|
##
|
|
# @transaction:
|
|
#
|
|
# Executes a number of transactionable QMP commands atomically. If any
|
|
# operation fails, then the entire set of actions will be abandoned and the
|
|
# appropriate error returned.
|
|
#
|
|
# For external snapshots, the dictionary contains the device, the file to use for
|
|
# the new snapshot, and the format. The default format, if not specified, is
|
|
# qcow2.
|
|
#
|
|
# Each new snapshot defaults to being created by QEMU (wiping any
|
|
# contents if the file already exists), but it is also possible to reuse
|
|
# an externally-created file. In the latter case, you should ensure that
|
|
# the new image file has the same contents as the current one; QEMU cannot
|
|
# perform any meaningful check. Typically this is achieved by using the
|
|
# current image file as the backing file for the new image.
|
|
#
|
|
# On failure, the original disks pre-snapshot attempt will be used.
|
|
#
|
|
# For internal snapshots, the dictionary contains the device and the
|
|
# snapshot's name. If an internal snapshot matching name already exists,
|
|
# the request will be rejected. Only some image formats support it, for
|
|
# example, qcow2, and rbd,
|
|
#
|
|
# On failure, qemu will try delete the newly created internal snapshot in the
|
|
# transaction. When an I/O error occurs during deletion, the user needs to fix
|
|
# it later with qemu-img or other command.
|
|
#
|
|
# @actions: List of @TransactionAction;
|
|
# information needed for the respective operations.
|
|
#
|
|
# @properties: structure of additional options to control the
|
|
# execution of the transaction. See @TransactionProperties
|
|
# for additional detail.
|
|
#
|
|
# Returns: nothing on success
|
|
#
|
|
# Errors depend on the operations of the transaction
|
|
#
|
|
# Note: The transaction aborts on the first failure. Therefore, there will be
|
|
# information on only one failed operation returned in an error condition, and
|
|
# subsequent actions will not have been attempted.
|
|
#
|
|
# Since: 1.1
|
|
#
|
|
# Example:
|
|
#
|
|
# -> { "execute": "transaction",
|
|
# "arguments": { "actions": [
|
|
# { "type": "blockdev-snapshot-sync", "data" : { "device": "ide-hd0",
|
|
# "snapshot-file": "/some/place/my-image",
|
|
# "format": "qcow2" } },
|
|
# { "type": "blockdev-snapshot-sync", "data" : { "node-name": "myfile",
|
|
# "snapshot-file": "/some/place/my-image2",
|
|
# "snapshot-node-name": "node3432",
|
|
# "mode": "existing",
|
|
# "format": "qcow2" } },
|
|
# { "type": "blockdev-snapshot-sync", "data" : { "device": "ide-hd1",
|
|
# "snapshot-file": "/some/place/my-image2",
|
|
# "mode": "existing",
|
|
# "format": "qcow2" } },
|
|
# { "type": "blockdev-snapshot-internal-sync", "data" : {
|
|
# "device": "ide-hd2",
|
|
# "name": "snapshot0" } } ] } }
|
|
# <- { "return": {} }
|
|
#
|
|
##
|
|
{ 'command': 'transaction',
|
|
'data': { 'actions': [ 'TransactionAction' ],
|
|
'*properties': 'TransactionProperties'
|
|
}
|
|
}
|