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authorFam Zheng <famz@redhat.com>2015-12-24 12:45:05 +0800
committerMax Reitz <mreitz@redhat.com>2016-01-07 21:30:18 +0100
commitdf92562e68d6676a52faeaf20e87526ceaa28003 (patch)
tree2e9ccdcd2a48a581be67f04f694fa90d040e1392
parente40e5027f6b0b7e981c4f1844180fb0e7947d1cd (diff)
downloadqemu-arm-df92562e68d6676a52faeaf20e87526ceaa28003.tar.gz
qmp: Add blockdev-mirror command
This will start a mirror job from a named device to another named device, its relation with drive-mirror is similar with blockdev-backup to drive-backup. In blockdev-mirror, the target node should be prepared by blockdev-add, which will be responsible for assigning a name to the new node, so we don't have 'node-name' parameter. Signed-off-by: Fam Zheng <famz@redhat.com> Acked-by: Markus Armbruster <armbru@redhat.com> Message-id: 1450932306-13717-5-git-send-email-famz@redhat.com Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
-rw-r--r--blockdev.c62
-rw-r--r--qapi/block-core.json48
-rw-r--r--qmp-commands.hx50
3 files changed, 159 insertions, 1 deletions
diff --git a/blockdev.c b/blockdev.c
index f42e1713e9..2df0c6d366 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -3345,6 +3345,10 @@ static void blockdev_mirror_common(BlockDriverState *bs,
if (bdrv_op_is_blocked(target, BLOCK_OP_TYPE_MIRROR_TARGET, errp)) {
return;
}
+ if (target->blk) {
+ error_setg(errp, "Cannot mirror to an attached block device");
+ return;
+ }
if (!bs->backing && sync == MIRROR_SYNC_MODE_TOP) {
sync = MIRROR_SYNC_MODE_FULL;
@@ -3518,6 +3522,64 @@ out:
aio_context_release(aio_context);
}
+void qmp_blockdev_mirror(const char *device, const char *target,
+ bool has_replaces, const char *replaces,
+ MirrorSyncMode sync,
+ bool has_speed, int64_t speed,
+ bool has_granularity, uint32_t granularity,
+ bool has_buf_size, int64_t buf_size,
+ bool has_on_source_error,
+ BlockdevOnError on_source_error,
+ bool has_on_target_error,
+ BlockdevOnError on_target_error,
+ Error **errp)
+{
+ BlockDriverState *bs;
+ BlockBackend *blk;
+ BlockDriverState *target_bs;
+ AioContext *aio_context;
+ Error *local_err = NULL;
+
+ blk = blk_by_name(device);
+ if (!blk) {
+ error_setg(errp, "Device '%s' not found", device);
+ return;
+ }
+ bs = blk_bs(blk);
+
+ if (!bs) {
+ error_setg(errp, "Device '%s' has no media", device);
+ return;
+ }
+
+ target_bs = bdrv_lookup_bs(target, target, errp);
+ if (!target_bs) {
+ return;
+ }
+
+ aio_context = bdrv_get_aio_context(bs);
+ aio_context_acquire(aio_context);
+
+ bdrv_ref(target_bs);
+ bdrv_set_aio_context(target_bs, aio_context);
+
+ blockdev_mirror_common(bs, target_bs,
+ has_replaces, replaces, sync,
+ has_speed, speed,
+ has_granularity, granularity,
+ has_buf_size, buf_size,
+ has_on_source_error, on_source_error,
+ has_on_target_error, on_target_error,
+ true, true,
+ &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ bdrv_unref(target_bs);
+ }
+
+ aio_context_release(aio_context);
+}
+
/* Get the block job for a given device name and acquire its AioContext */
static BlockJob *find_block_job(const char *device, AioContext **aio_context,
Error **errp)
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 1a5d9ce9bb..0a915eda59 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1184,6 +1184,54 @@
'data': 'BlockDirtyBitmap' }
##
+# @blockdev-mirror
+#
+# Start mirroring a block device's writes to a new destination.
+#
+# @device: the name of the device whose writes should be mirrored.
+#
+# @target: the id or node-name of the block device to mirror to. This mustn't be
+# attached to guest.
+#
+# @replaces: #optional with sync=full graph node name to be replaced by the new
+# image when a whole image copy is done. This can be used to repair
+# broken Quorum files.
+#
+# @speed: #optional the maximum speed, in bytes per second
+#
+# @sync: what parts of the disk image should be copied to the destination
+# (all the disk, only the sectors allocated in the topmost image, or
+# only new I/O).
+#
+# @granularity: #optional granularity of the dirty bitmap, default is 64K
+# if the image format doesn't have clusters, 4K if the clusters
+# are smaller than that, else the cluster size. Must be a
+# power of 2 between 512 and 64M
+#
+# @buf-size: #optional maximum amount of data in flight from source to
+# target
+#
+# @on-source-error: #optional the action to take on an error on the source,
+# default 'report'. 'stop' and 'enospc' can only be used
+# if the block device supports io-status (see BlockInfo).
+#
+# @on-target-error: #optional the action to take on an error on the target,
+# default 'report' (no limitations, since this applies to
+# a different block device than @device).
+#
+# Returns: nothing on success.
+#
+# Since 2.6
+##
+{ 'command': 'blockdev-mirror',
+ 'data': { 'device': 'str', 'target': 'str',
+ '*replaces': 'str',
+ 'sync': 'MirrorSyncMode',
+ '*speed': 'int', '*granularity': 'uint32',
+ '*buf-size': 'int', '*on-source-error': 'BlockdevOnError',
+ '*on-target-error': 'BlockdevOnError' } }
+
+##
# @block_set_io_throttle:
#
# Change I/O throttle limits for a block drive.
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 7b235eeff7..db072a6e4c 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -1635,7 +1635,7 @@ Arguments:
- "speed": maximum speed of the streaming job, in bytes per second
(json-int)
- "granularity": granularity of the dirty bitmap, in bytes (json-int, optional)
-- "buf_size": maximum amount of data in flight from source to target, in bytes
+- "buf-size": maximum amount of data in flight from source to target, in bytes
(json-int, default 10M)
- "sync": what parts of the disk image should be copied to the destination;
possibilities include "full" for all the disk, "top" for only the sectors
@@ -1665,6 +1665,54 @@ Example:
EQMP
{
+ .name = "blockdev-mirror",
+ .args_type = "sync:s,device:B,target:B,replaces:s?,speed:i?,"
+ "on-source-error:s?,on-target-error:s?,"
+ "granularity:i?,buf-size:i?",
+ .mhandler.cmd_new = qmp_marshal_blockdev_mirror,
+ },
+
+SQMP
+blockdev-mirror
+------------
+
+Start mirroring a block device's writes to another block device. target
+specifies the target of mirror operation.
+
+Arguments:
+
+- "device": device name to operate on (json-string)
+- "target": device name to mirror to (json-string)
+- "replaces": the block driver node name to replace when finished
+ (json-string, optional)
+- "speed": maximum speed of the streaming job, in bytes per second
+ (json-int)
+- "granularity": granularity of the dirty bitmap, in bytes (json-int, optional)
+- "buf_size": maximum amount of data in flight from source to target, in bytes
+ (json-int, default 10M)
+- "sync": what parts of the disk image should be copied to the destination;
+ possibilities include "full" for all the disk, "top" for only the sectors
+ allocated in the topmost image, or "none" to only replicate new I/O
+ (MirrorSyncMode).
+- "on-source-error": the action to take on an error on the source
+ (BlockdevOnError, default 'report')
+- "on-target-error": the action to take on an error on the target
+ (BlockdevOnError, default 'report')
+
+The default value of the granularity is the image cluster size clamped
+between 4096 and 65536, if the image format defines one. If the format
+does not define a cluster size, the default value of the granularity
+is 65536.
+
+Example:
+
+-> { "execute": "blockdev-mirror", "arguments": { "device": "ide-hd0",
+ "target": "target0",
+ "sync": "full" } }
+<- { "return": {} }
+
+EQMP
+ {
.name = "change-backing-file",
.args_type = "device:s,image-node-name:s,backing-file:s",
.mhandler.cmd_new = qmp_marshal_change_backing_file,