On 2015/4/1 16:19, Fam Zheng wrote: > On Wed, 04/01 12:42, Bin Wu wrote: >> From: Bin Wu <wu.wu...@huawei.com> > > What's the issue are you fixing? I think the coroutine already is running in > the AioContext of bs. > > Fam > In the current implementation of bdrv_drain, it should be placed in a critical section as suggested in the comments above the function: "Note that unlike bdrv_drain_all(), the caller must hold the BlockDriverState AioContext".
However, the mirror coroutine starting with mirror_run doesn't do this. I just found qmp_drive_mirror protects the AioCentext, but it is out of the scope of the mirror coroutine. Bin >> >> Signed-off-by: Bin Wu <wu.wu...@huawei.com> >> --- >> block/mirror.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/block/mirror.c b/block/mirror.c >> index 4056164..08372df 100644 >> --- a/block/mirror.c >> +++ b/block/mirror.c >> @@ -530,7 +530,9 @@ static void coroutine_fn mirror_run(void *opaque) >> * mirror_populate runs. >> */ >> trace_mirror_before_drain(s, cnt); >> + aio_context_acquire(bdrv_get_aio_context(bs)); >> bdrv_drain(bs); >> + aio_context_release(bdrv_get_aio_context(bs)); >> cnt = bdrv_get_dirty_count(bs, s->dirty_bitmap); >> } >> >> -- >> 1.7.12.4 >> >> >> > > . >
