@@ -1183,6 +1183,18 @@ void qmp_blockdev_snapshot_sync(bool has_device, const char *device,
&snapshot, errp);
}
+void qmp_blockdev_snapshot(const char *node, const char *overlay,
+ Error **errp)
+{
+ BlockdevSnapshot snapshot_data = {
+ .node = (char *) node,
+ .overlay = (char *) overlay
+ };
+
+ blockdev_do_action(TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT,
+ &snapshot_data, errp);
+}
+
void qmp_blockdev_snapshot_internal_sync(const char *device,
const char *name,
Error **errp)
@@ -1521,58 +1533,48 @@ typedef struct ExternalSnapshotState {
static void external_snapshot_prepare(BlkTransactionState *common,
Error **errp)
{
- int flags, ret;
- QDict *options;
+ int flags = 0, ret;
+ QDict *options = NULL;
Error *local_err = NULL;
- bool has_device = false;
+ /* Device and node name of the image to generate the snapshot from */
const char *device;
- bool has_node_name = false;
const char *node_name;
- bool has_snapshot_node_name = false;
- const char *snapshot_node_name;
+ /* Reference to the new image (for 'blockdev-snapshot') */
+ const char *snapshot_ref;
+ /* File name of the new image (for 'blockdev-snapshot-sync') */
const char *new_image_file;
- const char *format = "qcow2";
- enum NewImageMode mode = NEW_IMAGE_MODE_ABSOLUTE_PATHS;
ExternalSnapshotState *state =
DO_UPCAST(ExternalSnapshotState, common, common);
TransactionAction *action = common->action;
- /* get parameters */
- g_assert(action->kind == TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC);
-
- has_device = action->blockdev_snapshot_sync->has_device;
- device = action->blockdev_snapshot_sync->device;
- has_node_name = action->blockdev_snapshot_sync->has_node_name;
- node_name = action->blockdev_snapshot_sync->node_name;
- has_snapshot_node_name =
- action->blockdev_snapshot_sync->has_snapshot_node_name;
- snapshot_node_name = action->blockdev_snapshot_sync->snapshot_node_name;
-
- new_image_file = action->blockdev_snapshot_sync->snapshot_file;
- if (action->blockdev_snapshot_sync->has_format) {
- format = action->blockdev_snapshot_sync->format;
- }
- if (action->blockdev_snapshot_sync->has_mode) {
- mode = action->blockdev_snapshot_sync->mode;
+ /* 'blockdev-snapshot' and 'blockdev-snapshot-sync' have similar
+ * purpose but a different set of parameters */
+ switch (action->kind) {
+ case TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT:
+ {
+ BlockdevSnapshot *s = action->blockdev_snapshot;
+ device = s->node;
+ node_name = s->node;
+ new_image_file = NULL;
+ snapshot_ref = s->overlay;
+ }
+ break;
+ case TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC:
+ {
+ BlockdevSnapshotSync *s = action->blockdev_snapshot_sync;
+ device = s->has_device ? s->device : NULL;
+ node_name = s->has_node_name ? s->node_name : NULL;
+ new_image_file = s->snapshot_file;
+ snapshot_ref = NULL;
+ }
+ break;
+ default:
+ g_assert_not_reached();
}
/* start processing */
- state->old_bs = bdrv_lookup_bs(has_device ? device : NULL,
- has_node_name ? node_name : NULL,
- &local_err);
- if (local_err) {
- error_propagate(errp, local_err);
- return;
- }
-
- if (has_node_name && !has_snapshot_node_name) {
- error_setg(errp, "New snapshot node name missing");
- return;
- }
-
- if (has_snapshot_node_name &&
- bdrv_lookup_bs(snapshot_node_name, snapshot_node_name, NULL)) {
- error_setg(errp, "New snapshot node name already in use");
+ state->old_bs = bdrv_lookup_bs(device, node_name, errp);
+ if (!state->old_bs) {
return;
}
@@ -1602,35 +1604,70 @@ static void external_snapshot_prepare(BlkTransactionState *common,
return;
}
- flags = state->old_bs->open_flags;
+ if (action->kind == TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC) {
+ BlockdevSnapshotSync *s = action->blockdev_snapshot_sync;
+ const char *format = s->has_format ? s->format : "qcow2";
+ enum NewImageMode mode;
+ const char *snapshot_node_name =
+ s->has_snapshot_node_name ? s->snapshot_node_name : NULL;
- /* create new image w/backing file */
- if (mode != NEW_IMAGE_MODE_EXISTING) {
- bdrv_img_create(new_image_file, format,
- state->old_bs->filename,
- state->old_bs->drv->format_name,
- NULL, -1, flags, &local_err, false);
- if (local_err) {
- error_propagate(errp, local_err);
+ if (node_name && !snapshot_node_name) {
+ error_setg(errp, "New snapshot node name missing");
return;
}
- }
- options = qdict_new();
- if (has_snapshot_node_name) {
- qdict_put(options, "node-name",
- qstring_from_str(snapshot_node_name));
+ if (snapshot_node_name &&
+ bdrv_lookup_bs(snapshot_node_name, snapshot_node_name, NULL)) {
+ error_setg(errp, "New snapshot node name already in use");
+ return;
+ }
+
+ flags = state->old_bs->open_flags;
+
+ /* create new image w/backing file */
+ mode = s->has_mode ? s->mode : NEW_IMAGE_MODE_ABSOLUTE_PATHS;
+ if (mode != NEW_IMAGE_MODE_EXISTING) {
+ bdrv_img_create(new_image_file, format,
+ state->old_bs->filename,
+ state->old_bs->drv->format_name,
+ NULL, -1, flags, &local_err, false);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ return;
+ }
+ }
+
+ options = qdict_new();
+ if (s->has_snapshot_node_name) {
+ qdict_put(options, "node-name",
+ qstring_from_str(snapshot_node_name));
+ }
+ qdict_put(options, "driver", qstring_from_str(format));
+
+ flags |= BDRV_O_NO_BACKING;
}
- qdict_put(options, "driver", qstring_from_str(format));
- /* TODO Inherit bs->options or only take explicit options with an
- * extended QMP command? */
assert(state->new_bs == NULL);
- ret = bdrv_open(&state->new_bs, new_image_file, NULL, options,
- flags | BDRV_O_NO_BACKING, &local_err);
+ ret = bdrv_open(&state->new_bs, new_image_file, snapshot_ref, options,
+ flags, errp);
/* We will manually add the backing_hd field to the bs later */
if (ret != 0) {
- error_propagate(errp, local_err);
+ return;
+ }
+
+ if (state->new_bs->blk != NULL) {
+ error_setg(errp, "The snapshot is already in use by %s",
+ blk_name(state->new_bs->blk));
+ return;
+ }
+
+ if (bdrv_op_is_blocked(state->new_bs, BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT,
+ errp)) {
+ return;
+ }
+
+ if (state->new_bs->backing_hd != NULL) {
+ error_setg(errp, "The snapshot already has a backing image");
}
}
@@ -1819,6 +1856,12 @@ static void abort_commit(BlkTransactionState *common)
}
static const BdrvActionOps actions[] = {
+ [TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT] = {
+ .instance_size = sizeof(ExternalSnapshotState),
+ .prepare = external_snapshot_prepare,
+ .commit = external_snapshot_commit,
+ .abort = external_snapshot_abort,
+ },
[TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC] = {
.instance_size = sizeof(ExternalSnapshotState),
.prepare = external_snapshot_prepare,
@@ -1531,9 +1531,11 @@
# abort since 1.6
# blockdev-snapshot-internal-sync since 1.7
# blockdev-backup since 2.3
+# blockdev-snapshot since 2.5
##
{ 'union': 'TransactionAction',
'data': {
+ 'blockdev-snapshot': 'BlockdevSnapshot',
'blockdev-snapshot-sync': 'BlockdevSnapshotSync',
'drive-backup': 'DriveBackup',
'blockdev-backup': 'BlockdevBackup',
@@ -705,6 +705,21 @@
'*format': 'str', '*mode': 'NewImageMode' } }
##
+# @BlockdevSnapshot
+#
+# @node: device or node name that will have a snapshot created.
+#
+# @overlay: reference to the existing block device that will become
+# the overlay of @node, as part of creating the snapshot.
+# It must not have a current backing file (this can be
+# achieved by passing "backing": "" to blockdev-add).
+#
+# Since 2.5
+##
+{ 'struct': 'BlockdevSnapshot',
+ 'data': { 'node': 'str', 'overlay': 'str' } }
+
+##
# @DriveBackup
#
# @device: the name of the device which should be copied.
@@ -800,6 +815,19 @@
{ 'command': 'blockdev-snapshot-sync',
'data': 'BlockdevSnapshotSync' }
+
+##
+# @blockdev-snapshot
+#
+# Generates a snapshot of a block device.
+#
+# For the arguments, see the documentation of BlockdevSnapshot.
+#
+# Since 2.5
+##
+{ 'command': 'blockdev-snapshot',
+ 'data': 'BlockdevSnapshot' }
+
##
# @change-backing-file
#
@@ -1461,6 +1461,44 @@ Example:
EQMP
{
+ .name = "blockdev-snapshot",
+ .args_type = "node:s,overlay:s",
+ .mhandler.cmd_new = qmp_marshal_blockdev_snapshot,
+ },
+
+SQMP
+blockdev-snapshot
+-----------------
+Since 2.5
+
+Create a snapshot, by installing 'node' as the backing image of
+'overlay'. Additionally, if 'node' is associated with a block
+device, the block device changes to using 'overlay' as its new active
+image.
+
+Arguments:
+
+- "node": device that will have a snapshot created (json-string)
+- "overlay": device that will have 'node' as its backing image (json-string)
+
+Example:
+
+-> { "execute": "blockdev-add",
+ "arguments": { "options": { "driver": "qcow2",
+ "node-name": "node1534",
+ "file": { "driver": "file",
+ "filename": "hd1.qcow2" },
+ "backing": "" } } }
+
+<- { "return": {} }
+
+-> { "execute": "blockdev-snapshot", "arguments": { "node": "ide-hd0",
+ "overlay": "node1534" } }
+<- { "return": {} }
+
+EQMP
+
+ {
.name = "blockdev-snapshot-internal-sync",
.args_type = "device:B,name:s",
.mhandler.cmd_new = qmp_marshal_blockdev_snapshot_internal_sync,