block: Add replaces argument to drive-mirror
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 <benoit@irqsave.net>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/block/mirror.c b/block/mirror.c
index 7c9f898..6c3ee70 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -32,6 +32,12 @@
RateLimit limit;
BlockDriverState *target;
BlockDriverState *base;
+ /* The name of the graph node to replace */
+ char *replaces;
+ /* The 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;
@@ -500,10 +506,14 @@
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 */
@@ -512,6 +522,12 @@
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);
+ }
+ g_free(s->replaces);
bdrv_unref(s->target);
block_job_completed(&s->common, ret);
}
@@ -550,6 +566,20 @@
return;
}
+ /* check the target bs is not blocked and block all operations on it */
+ if (s->replaces) {
+ s->to_replace = check_to_replace_node(s->replaces, &local_err);
+ if (!s->to_replace) {
+ error_propagate(errp, local_err);
+ 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);
+ }
+
s->should_complete = true;
block_job_resume(job);
}
@@ -572,14 +602,15 @@
};
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;
@@ -610,6 +641,7 @@
return;
}
+ s->replaces = g_strdup(replaces);
s->on_source_error = on_source_error;
s->on_target_error = on_target_error;
s->target = target;
@@ -631,6 +663,7 @@
}
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,
@@ -642,7 +675,8 @@
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);
}
@@ -690,7 +724,7 @@
}
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) {
