@@ -57,6 +57,8 @@ typedef struct MirrorBlockJob {
int in_flight;
int sectors_in_flight;
int ret;
+ /* True if the source is locked by us */
+ bool need_unlock;
} MirrorBlockJob;
typedef struct MirrorOp {
@@ -358,6 +360,9 @@ static void mirror_exit(BlockJob *job, void *opaque)
if (replace_aio_context) {
aio_context_release(replace_aio_context);
}
+ if (s->need_unlock) {
+ bdrv_unlock(s->common.bs);
+ }
g_free(s->replaces);
bdrv_unref(s->target);
block_job_completed(&s->common, data->ret);
@@ -521,7 +526,8 @@ static void coroutine_fn mirror_run(void *opaque)
* mirror_populate runs.
*/
trace_mirror_before_drain(s, cnt);
- bdrv_drain(bs);
+ bdrv_lock(bs);
+ s->need_unlock = true;
cnt = bdrv_get_dirty_count(s->dirty_bitmap);
}
@@ -543,6 +549,10 @@ static void coroutine_fn mirror_run(void *opaque)
s->common.cancelled = false;
break;
}
+ if (s->need_unlock) {
+ bdrv_unlock(bs);
+ s->need_unlock = false;
+ }
last_pause_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
}
@@ -565,7 +575,11 @@ immediate_exit:
data = g_malloc(sizeof(*data));
data->ret = ret;
- block_job_defer_to_main_loop(&s->common, mirror_exit, data);
+ if (bs->aio_context == qemu_get_aio_context()) {
+ mirror_exit(&s->common, data);
+ } else {
+ block_job_defer_to_main_loop(&s->common, mirror_exit, data);
+ }
}
static void mirror_set_speed(BlockJob *job, int64_t speed, Error **errp)
Source and target are in sync when we leave the mirror_run loop, they should remain so until bdrv_swap. Before block_job_defer_to_main_loop was introduced, it has been easy to prove that. Now that tricky things can happen after mirror_run returns and before mirror_exit runs, for example, ioeventfd handlers being called, or a device model timer callback submitting more I/O. So, skip the block_job_defer_to_main_loop if we're already in the main context. This is a necessary special casing until BlockBackend really honors bdrv_lock. If we're not in the main context, we rely on the notifying mechanism to do the right thing. Signed-off-by: Fam Zheng <famz@redhat.com> --- block/mirror.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-)