diff options
| -rw-r--r-- | blockdev.c | 165 | ||||
| -rw-r--r-- | qapi-schema.json | 2 | ||||
| -rw-r--r-- | qapi/block-core.json | 28 | ||||
| -rw-r--r-- | qmp-commands.hx | 38 |
4 files changed, 172 insertions, 61 deletions
diff --git a/blockdev.c b/blockdev.c index 86a29d8fa3..7645d491cb 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1185,6 +1185,18 @@ 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) @@ -1530,58 +1542,48 @@ 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->type == TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC); - - has_device = action->u.blockdev_snapshot_sync->has_device; - device = action->u.blockdev_snapshot_sync->device; - has_node_name = action->u.blockdev_snapshot_sync->has_node_name; - node_name = action->u.blockdev_snapshot_sync->node_name; - has_snapshot_node_name = - action->u.blockdev_snapshot_sync->has_snapshot_node_name; - snapshot_node_name = action->u.blockdev_snapshot_sync->snapshot_node_name; - - new_image_file = action->u.blockdev_snapshot_sync->snapshot_file; - if (action->u.blockdev_snapshot_sync->has_format) { - format = action->u.blockdev_snapshot_sync->format; - } - if (action->u.blockdev_snapshot_sync->has_mode) { - mode = action->u.blockdev_snapshot_sync->mode; + /* 'blockdev-snapshot' and 'blockdev-snapshot-sync' have similar + * purpose but a different set of parameters */ + switch (action->type) { + case TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT: + { + BlockdevSnapshot *s = action->u.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->u.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; } @@ -1612,35 +1614,70 @@ static void external_snapshot_prepare(BlkTransactionState *common, return; } - flags = state->old_bs->open_flags; + if (action->type == TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC) { + BlockdevSnapshotSync *s = action->u.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 != NULL) { + error_setg(errp, "The snapshot already has a backing image"); } } @@ -1843,6 +1880,12 @@ 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, diff --git a/qapi-schema.json b/qapi-schema.json index 04a01b1247..c3f95ab170 100644 --- a/qapi-schema.json +++ b/qapi-schema.json @@ -1545,9 +1545,11 @@ # 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', diff --git a/qapi/block-core.json b/qapi/block-core.json index f592adc8df..083d2cd346 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -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 # diff --git a/qmp-commands.hx b/qmp-commands.hx index 39d6e25121..5fd6f9c0e3 100644 --- a/qmp-commands.hx +++ b/qmp-commands.hx @@ -1495,6 +1495,44 @@ 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, |