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[Qemu-devel] [PATCH v8 3/4] block: Add replaces argument to drive-mirror
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From: |
Benoît Canet |
|
Subject: |
[Qemu-devel] [PATCH v8 3/4] block: Add replaces argument to drive-mirror |
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Date: |
Tue, 10 Jun 2014 09:21:45 +0200 |
drive-mirror will bdrv_swap the new BDS named node-name with the one
pointed by replaces when the mirroring is finished.
Signed-off-by: Benoit Canet <address@hidden>
---
block.c | 26 ++++++++++++++++++++
block/mirror.c | 62 +++++++++++++++++++++++++++++++++++++----------
blockdev.c | 30 ++++++++++++++++++++++-
hmp.c | 2 +-
include/block/block.h | 4 +++
include/block/block_int.h | 4 ++-
qapi/block-core.json | 6 ++++-
qmp-commands.hx | 4 ++-
8 files changed, 120 insertions(+), 18 deletions(-)
diff --git a/block.c b/block.c
index 17f763d..0a79b65 100644
--- a/block.c
+++ b/block.c
@@ -5795,3 +5795,29 @@ bool bdrv_is_first_non_filter(BlockDriverState
*candidate)
return false;
}
+
+BlockDriverState *check_to_replace_node(const char *node_name, Error **errp)
+{
+ BlockDriverState *to_replace_bs = bdrv_find_node(node_name);
+ if (!to_replace_bs) {
+ error_setg(errp, "node_name=%s not found",
+ node_name);
+ return NULL;
+ }
+
+ /* the code should only be able to replace the top first non filter
+ * node of the graph. For example the first BDS under a quorum.
+ */
+ if (!bdrv_is_first_non_filter(to_replace_bs)) {
+ error_set(errp, QERR_FEATURE_DISABLED,
+ "drive-mirror and replace node-name");
+ return NULL;
+ }
+
+ if (bdrv_op_is_blocked(to_replace_bs, BLOCK_OP_TYPE_REPLACE, errp)) {
+ return NULL;
+ }
+
+ return to_replace_bs;
+}
+
diff --git a/block/mirror.c b/block/mirror.c
index 94c8661..13568eb 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -32,6 +32,12 @@ typedef struct MirrorBlockJob {
RateLimit limit;
BlockDriverState *target;
BlockDriverState *base;
+ /* The name of the graph node to replace */
+ char *replaces;
+ /* The block BDS to replace */
+ BlockDriverState *to_replace;
+ /* Used to block operations on the drive-mirror-replace target */
+ Error *replace_blocker;
bool is_none_mode;
BlockdevOnError on_source_error, on_target_error;
bool synced;
@@ -490,10 +496,14 @@ immediate_exit:
bdrv_release_dirty_bitmap(bs, s->dirty_bitmap);
bdrv_iostatus_disable(s->target);
if (s->should_complete && ret == 0) {
- if (bdrv_get_flags(s->target) != bdrv_get_flags(s->common.bs)) {
- bdrv_reopen(s->target, bdrv_get_flags(s->common.bs), NULL);
+ BlockDriverState *to_replace = s->common.bs;
+ if (s->to_replace) {
+ to_replace = s->to_replace;
}
- bdrv_swap(s->target, s->common.bs);
+ if (bdrv_get_flags(s->target) != bdrv_get_flags(to_replace)) {
+ bdrv_reopen(s->target, bdrv_get_flags(to_replace), NULL);
+ }
+ bdrv_swap(s->target, to_replace);
if (s->common.driver->job_type == BLOCK_JOB_TYPE_COMMIT) {
/* drop the bs loop chain formed by the swap: break the loop then
* trigger the unref from the top one */
@@ -502,6 +512,11 @@ immediate_exit:
bdrv_unref(p);
}
}
+ if (s->to_replace) {
+ bdrv_op_unblock_all(s->to_replace, s->replace_blocker);
+ error_free(s->replace_blocker);
+ bdrv_unref(s->to_replace);
+ }
bdrv_unref(s->target);
block_job_completed(&s->common, ret);
}
@@ -540,6 +555,23 @@ static void mirror_complete(BlockJob *job, Error **errp)
return;
}
+ /* check the target bs is not block and block all operations on it */
+ if (s->replaces) {
+ s->to_replace = check_to_replace_node(s->replaces, errp);
+
+ if (!s->to_replace) {
+ return;
+ }
+
+ error_setg(&s->replace_blocker,
+ "block device is in use by block-job-complete");
+ bdrv_op_block_all(s->to_replace, s->replace_blocker);
+ bdrv_ref(s->to_replace);
+
+ g_free(s->replaces);
+ s->replaces = NULL;
+ }
+
s->should_complete = true;
block_job_resume(job);
}
@@ -562,14 +594,15 @@ static const BlockJobDriver commit_active_job_driver = {
};
static void mirror_start_job(BlockDriverState *bs, BlockDriverState *target,
- int64_t speed, int64_t granularity,
- int64_t buf_size,
- BlockdevOnError on_source_error,
- BlockdevOnError on_target_error,
- BlockDriverCompletionFunc *cb,
- void *opaque, Error **errp,
- const BlockJobDriver *driver,
- bool is_none_mode, BlockDriverState *base)
+ const char *replaces,
+ int64_t speed, int64_t granularity,
+ int64_t buf_size,
+ BlockdevOnError on_source_error,
+ BlockdevOnError on_target_error,
+ BlockDriverCompletionFunc *cb,
+ void *opaque, Error **errp,
+ const BlockJobDriver *driver,
+ bool is_none_mode, BlockDriverState *base)
{
MirrorBlockJob *s;
@@ -600,6 +633,7 @@ static void mirror_start_job(BlockDriverState *bs,
BlockDriverState *target,
return;
}
+ s->replaces = g_strdup(replaces);
s->on_source_error = on_source_error;
s->on_target_error = on_target_error;
s->target = target;
@@ -621,6 +655,7 @@ static void mirror_start_job(BlockDriverState *bs,
BlockDriverState *target,
}
void mirror_start(BlockDriverState *bs, BlockDriverState *target,
+ const char *replaces,
int64_t speed, int64_t granularity, int64_t buf_size,
MirrorSyncMode mode, BlockdevOnError on_source_error,
BlockdevOnError on_target_error,
@@ -632,7 +667,8 @@ void mirror_start(BlockDriverState *bs, BlockDriverState
*target,
is_none_mode = mode == MIRROR_SYNC_MODE_NONE;
base = mode == MIRROR_SYNC_MODE_TOP ? bs->backing_hd : NULL;
- mirror_start_job(bs, target, speed, granularity, buf_size,
+ mirror_start_job(bs, target, replaces,
+ speed, granularity, buf_size,
on_source_error, on_target_error, cb, opaque, errp,
&mirror_job_driver, is_none_mode, base);
}
@@ -680,7 +716,7 @@ void commit_active_start(BlockDriverState *bs,
BlockDriverState *base,
}
bdrv_ref(base);
- mirror_start_job(bs, base, speed, 0, 0,
+ mirror_start_job(bs, base, NULL, speed, 0, 0,
on_error, on_error, cb, opaque, &local_err,
&commit_active_job_driver, false, base);
if (local_err) {
diff --git a/blockdev.c b/blockdev.c
index 06b14f2..237a548 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2107,6 +2107,7 @@ BlockDeviceInfoList *qmp_query_named_block_nodes(Error
**errp)
void qmp_drive_mirror(const char *device, const char *target,
bool has_format, const char *format,
bool has_node_name, const char *node_name,
+ bool has_replaces, const char *replaces,
enum MirrorSyncMode sync,
bool has_mode, enum NewImageMode mode,
bool has_speed, int64_t speed,
@@ -2194,6 +2195,28 @@ void qmp_drive_mirror(const char *device, const char
*target,
return;
}
+ if (has_replaces) {
+ BlockDriverState *to_replace_bs;
+
+ if (!has_node_name) {
+ error_setg(errp, "a node-name must be provided when replacing a"
+ " named node of the graph");
+ return;
+ }
+
+ to_replace_bs = check_to_replace_node(replaces, errp);
+
+ if (!to_replace_bs) {
+ return;
+ }
+
+ if (size != bdrv_getlength(to_replace_bs)) {
+ error_setg(errp, "cannot replace image with a mirror image of "
+ "different size");
+ return;
+ }
+ }
+
if ((sync == MIRROR_SYNC_MODE_FULL || !source)
&& mode != NEW_IMAGE_MODE_EXISTING)
{
@@ -2238,7 +2261,12 @@ void qmp_drive_mirror(const char *device, const char
*target,
return;
}
- mirror_start(bs, target_bs, speed, granularity, buf_size, sync,
+ /* pass the node name to replace to mirror start since it's loose coupling
+ * and will allow to check whether the node still exist at mirror
completion
+ */
+ mirror_start(bs, target_bs,
+ has_replaces ? replaces : NULL,
+ speed, granularity, buf_size, sync,
on_source_error, on_target_error,
block_job_cb, bs, &local_err);
if (local_err != NULL) {
diff --git a/hmp.c b/hmp.c
index ef0d583..9a4b8da 100644
--- a/hmp.c
+++ b/hmp.c
@@ -930,7 +930,7 @@ void hmp_drive_mirror(Monitor *mon, const QDict *qdict)
}
qmp_drive_mirror(device, filename, !!format, format,
- false, NULL,
+ false, NULL, false, NULL,
full ? MIRROR_SYNC_MODE_FULL : MIRROR_SYNC_MODE_TOP,
true, mode, false, 0, false, 0, false, 0,
false, 0, false, 0, &err);
diff --git a/include/block/block.h b/include/block/block.h
index 7d86e29..b0ed701 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -179,6 +179,7 @@ typedef enum BlockOpType {
BLOCK_OP_TYPE_MIRROR,
BLOCK_OP_TYPE_RESIZE,
BLOCK_OP_TYPE_STREAM,
+ BLOCK_OP_TYPE_REPLACE,
BLOCK_OP_TYPE_MAX,
} BlockOpType;
@@ -319,6 +320,9 @@ bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs,
BlockDriverState *candidate);
bool bdrv_is_first_non_filter(BlockDriverState *candidate);
+/* check if a named node can be replaced when doing drive-mirror */
+BlockDriverState *check_to_replace_node(const char *node_name, Error **errp);
+
/* async block I/O */
typedef void BlockDriverDirtyHandler(BlockDriverState *bs, int64_t sector,
int sector_num);
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 8d58334..fdf3ed2 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -86,7 +86,6 @@ struct BlockDriver {
*/
bool (*bdrv_recurse_is_first_non_filter)(BlockDriverState *bs,
BlockDriverState *candidate);
-
int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
int (*bdrv_probe_device)(const char *filename);
@@ -492,6 +491,8 @@ void commit_active_start(BlockDriverState *bs,
BlockDriverState *base,
* mirror_start:
* @bs: Block device to operate on.
* @target: Block device to write to.
+ * @replaces: Block graph node name to replace once the mirror is done. Can
+ * only be used when full mirroring is selected.
* @speed: The maximum speed, in bytes per second, or 0 for unlimited.
* @granularity: The chosen granularity for the dirty bitmap.
* @buf_size: The amount of data that can be in flight at one time.
@@ -508,6 +509,7 @@ void commit_active_start(BlockDriverState *bs,
BlockDriverState *base,
* @bs will be switched to read from @target.
*/
void mirror_start(BlockDriverState *bs, BlockDriverState *target,
+ const char *replaces,
int64_t speed, int64_t granularity, int64_t buf_size,
MirrorSyncMode mode, BlockdevOnError on_source_error,
BlockdevOnError on_target_error,
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 4c28d7b..0f8e703 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -772,6 +772,10 @@
# @node-name: #optional the new block driver state node name in the graph
# (Since 2.1)
#
+# @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. (Since 2.1)
+#
# @mode: #optional whether and how QEMU should create a new image, default is
# 'absolute-paths'.
#
@@ -804,7 +808,7 @@
##
{ 'command': 'drive-mirror',
'data': { 'device': 'str', 'target': 'str', '*format': 'str',
- '*node-name': 'str',
+ '*node-name': 'str', '*replaces': 'str',
'sync': 'MirrorSyncMode', '*mode': 'NewImageMode',
'*speed': 'int', '*granularity': 'uint32',
'*buf-size': 'int', '*on-source-error': 'BlockdevOnError',
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 98c28f5..4a76054 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -1293,7 +1293,7 @@ EQMP
{
.name = "drive-mirror",
.args_type = "sync:s,device:B,target:s,speed:i?,mode:s?,format:s?,"
- "node-name:s?,"
+ "node-name:s?,replaces:s?,"
"on-source-error:s?,on-target-error:s?,"
"granularity:i?,buf-size:i?",
.mhandler.cmd_new = qmp_marshal_input_drive_mirror,
@@ -1317,6 +1317,8 @@ Arguments:
- "format": format of new image (json-string, optional)
- "node-name": the name of the new block driver state in the node graph
(json-string, optional)
+- "replaces": the block driver node name to replace when finished
+ (json-string, optional)
- "mode": how an image file should be created into the target
file/device (NewImageMode, optional, default 'absolute-paths')
- "speed": maximum speed of the streaming job, in bytes per second
--
1.9.1