qemu/qapi/transaction.json
Markus Armbruster 277b51fc01 qapi: Convert simple union TransactionAction to flat one
Simple unions predate flat unions.  Having both complicates the QAPI
schema language and the QAPI generator.  We haven't been using simple
unions in new code for a long time, because they are less flexible and
somewhat awkward on the wire.

To prepare for their removal, convert simple union TransactionAction
to an equivalent flat one.  Adds some boilerplate to the schema, which
is a bit ugly, but a lot easier to maintain than the simple union
feature.

Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Hanna Reitz <hreitz@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20210917143134.412106-11-armbru@redhat.com>
2021-09-27 08:23:25 +02:00

255 lines
7.4 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
#
# 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',
'drive-backup' ] }
##
# @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'
}
}