Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> --- blockdev.c | 42 ++++++++++++++++++++++++++++++++---------- qapi-schema.json | 19 ++++++++++++++++++- qmp-commands.hx | 12 +++++++++++- 3 files changed, 61 insertions(+), 12 deletions(-)
diff --git a/blockdev.c b/blockdev.c index 8fcdf0e..f181c6f 100644 --- a/blockdev.c +++ b/blockdev.c @@ -733,6 +733,7 @@ void qmp_blockdev_transaction(BlockdevActionList *dev_list, int ret = 0; BlockdevActionList *dev_entry = dev_list; BlkTransactionStates *states; + char *new_source = NULL; QSIMPLEQ_HEAD(snap_bdrv_states, BlkTransactionStates) snap_bdrv_states; QSIMPLEQ_INIT(&snap_bdrv_states); @@ -744,12 +745,12 @@ void qmp_blockdev_transaction(BlockdevActionList *dev_list, while (NULL != dev_entry) { BlockdevAction *dev_info = NULL; BlockDriver *proto_drv; - BlockDriver *drv; + BlockDriver *target_drv; + BlockDriver *drv = NULL; int flags; const char *device; const char *format = "qcow2"; const char *new_image_file = NULL; - bool do_snapshot; dev_info = dev_entry->value; dev_entry = dev_entry->next; @@ -760,21 +761,40 @@ void qmp_blockdev_transaction(BlockdevActionList *dev_list, switch (dev_info->kind) { case BLOCKDEV_ACTION_KIND_SNAPSHOT: device = dev_info->snapshot->device; - do_snapshot = !dev_info->snapshot->has_reuse || !dev_info->snapshot->reuse; + if (!dev_info->snapshot->has_reuse || !dev_info->snapshot->reuse) { + new_image_file = dev_info->snapshot->snapshot_file; + } if (dev_info->snapshot->has_format) { format = dev_info->snapshot->format; } - new_image_file = dev_info->snapshot->snapshot_file; + new_source = g_strdup(dev_info->snapshot->snapshot_file); break; + + case BLOCKDEV_ACTION_KIND_MIRROR: + device = dev_info->mirror->device; + drv = bdrv_find_format("blkmirror"); + if (!dev_info->mirror->has_reuse || !dev_info->mirror->reuse) { + new_image_file = dev_info->mirror->target; + } + if (dev_info->mirror->has_format) { + format = dev_info->mirror->format; + } + new_source = g_strdup_printf("blkmirror:%s:%s", format, + dev_info->mirror->target); + break; + default: abort(); } - drv = bdrv_find_format(format); - if (!drv) { + target_drv = bdrv_find_format(format); + if (!target_drv) { error_set(errp, QERR_INVALID_BLOCK_FORMAT, format); goto delete_and_fail; } + if (!drv) { + drv = target_drv; + } states->old_bs = bdrv_find(device); if (!states->old_bs) { @@ -798,14 +817,14 @@ void qmp_blockdev_transaction(BlockdevActionList *dev_list, flags = states->old_bs->open_flags; - proto_drv = bdrv_find_protocol(new_image_file); + proto_drv = bdrv_find_protocol(new_source); if (!proto_drv) { error_set(errp, QERR_INVALID_BLOCK_FORMAT, format); goto delete_and_fail; } /* create new image w/backing file */ - if (do_snapshot) { + if (new_image_file) { ret = bdrv_img_create(new_image_file, format, states->old_bs->filename, states->old_bs->drv->format_name, @@ -818,12 +837,14 @@ void qmp_blockdev_transaction(BlockdevActionList *dev_list, /* We will manually add the backing_hd field to the bs later */ states->new_bs = bdrv_new(""); - ret = bdrv_open(states->new_bs, new_image_file, + ret = bdrv_open(states->new_bs, new_source, flags | BDRV_O_NO_BACKING, drv); if (ret != 0) { - error_set(errp, QERR_OPEN_FILE_FAILED, new_image_file); + error_set(errp, QERR_OPEN_FILE_FAILED, new_source); goto delete_and_fail; } + g_free(new_source); + new_source = NULL; } @@ -851,6 +872,7 @@ exit: QSIMPLEQ_FOREACH(states, &snap_bdrv_states, entry) { g_free(states); } + g_free(new_source); return; } diff --git a/qapi-schema.json b/qapi-schema.json index 78df122..fd5973d 100644 --- a/qapi-schema.json +++ b/qapi-schema.json @@ -1131,6 +1131,22 @@ '*reuse': 'bool' } } ## +# @BlockdevMirror +# +# @device: the name of the device to start mirroring. +# +# @target: the image that will start receiving writes for @device. A new +# file will be created if @reuse is absent or false. +# +# @format: #optional the format of the target image, default is 'qcow2'. +# +# @reuse: #optional whether QEMU should create a new image. +## +{ 'type': 'BlockdevMirror', + 'data': { 'device': 'str', 'target': 'str', '*format': 'str', + '*reuse': 'bool' } } + +## # @BlockdevAction # # A discriminated record of operations that can be performed with @@ -1138,7 +1154,8 @@ ## { 'union': 'BlockdevAction', 'data': { - 'snapshot': 'BlockdevSnapshot' + 'snapshot': 'BlockdevSnapshot', + 'mirror': 'BlockdevMirror', } } ## diff --git a/qmp-commands.hx b/qmp-commands.hx index 817b689..50ac5a0 100644 --- a/qmp-commands.hx +++ b/qmp-commands.hx @@ -701,7 +701,11 @@ operation for now is snapshotting. If there is any failure performing any of the operations, all snapshots for the group are abandoned, and the original disks pre-snapshot attempt are used. +Mirrored writes keep the previous image file open, and start writing +data also to the new file specified in the command. + A list of dictionaries is accepted, that contains the actions to be performed. + For snapshots this is the device, the file to use for the new snapshot, and the format. The default format, if not specified, is qcow2. @@ -716,7 +720,7 @@ Arguments: actions array: - "type": the operation to perform. The only supported - value is "snapshot". (json-string) + values are "snapshot" and "mirror". (json-string) - "data": a dictionary. The contents depend on the value of "type". When "type" is "snapshot": - "device": device name to snapshot (json-string) @@ -724,6 +728,12 @@ actions array: - "format": format of new image (json-string, optional) - "reuse": whether QEMU should look for an existing image file (json-bool, optional, default false) + When "type" is "mirror": + - "device": device name to snapshot (json-string) + - "target": name of destination image file (json-string) + - "format": format of new image (json-string, optional) + - "reuse": whether QEMU should look for an existing image file + (json-bool, optional, default false) Example: -- 1.7.7.6