blk-mq: call commit_rqs while list empty but error happen

Blk-mq should call commit_rqs once 'bd.last != true' and no more
request will come(so virtscsi can kick the virtqueue, e.g.). We already
do that in 'blk_mq_dispatch_rq_list/blk_mq_try_issue_list_directly' while
list not empty and 'queued > 0'. However, we can seen the same scene
once the last request in list call queue_rq and return error like
BLK_STS_IOERR which will not requeue the request, and lead that list
empty but need call commit_rqs too(Or the request for virtscsi will stay
timeout until other request kick virtqueue).

We found this problem by do fsstress test with offline/online virtscsi
device repeat quickly.

Fixes: d666ba98f849 ("blk-mq: add mq_ops->commit_rqs()")
Reported-by: zhangyi (F) <[email protected]>
Signed-off-by: yangerkun <[email protected]>
Reviewed-by: Ming Lei <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

0 files changed, 0 insertions, 0 deletions