The fact that the bs->aio_context is changing can confuse the dataplane iothread, because of the now fine granularity aio context lock. bdrv_drain should rather be a bdrv_drained_begin/end pair, but since bs->aio_context is changing, we can just use aio_disable_external and block_job_pause.
Reported-by: Ed Swierk <[email protected]> Signed-off-by: Fam Zheng <[email protected]> --- block.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/block.c b/block.c index 8893ac1..e70684a 100644 --- a/block.c +++ b/block.c @@ -4395,11 +4395,14 @@ void bdrv_attach_aio_context(BlockDriverState *bs, void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context) { - AioContext *ctx; + AioContext *ctx = bdrv_get_aio_context(bs); + aio_disable_external(ctx); + if (bs->job) { + block_job_pause(bs->job); + } bdrv_drain(bs); /* ensure there are no in-flight requests */ - ctx = bdrv_get_aio_context(bs); while (aio_poll(ctx, false)) { /* wait for all bottom halves to execute */ } @@ -4412,6 +4415,10 @@ void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context) aio_context_acquire(new_context); bdrv_attach_aio_context(bs, new_context); aio_context_release(new_context); + if (bs->job) { + block_job_resume(bs->job); + } + aio_enable_external(ctx); } void bdrv_add_aio_context_notifier(BlockDriverState *bs, -- 2.9.3
