Since blk_cleanup_queue() waits until q->q_usage_counter drops to zero before setting the "dead" flag, it is guaranteed that all requests that were in progress when blk_cleanup_queue() was called have finished before the "dead" flag is set. This means it is not possible that any .queue_rq() call is ongoing while the "dead" flag is set. Hence remove the code that waits for ongoing .queue_rq() calls to finish after the "dead" flag has been set. See also commit c2856ae2f315 ("blk-mq: quiesce queue before freeing queue") # v4.16.

Cc: Christoph Hellwig hch@infradead.org Cc: Hannes Reinecke hare@suse.com Cc: James Smart james.smart@broadcom.com Cc: Ming Lei ming.lei@redhat.com Cc: Jianchao Wang jianchao.w.wang@oracle.com Cc: Dongli Zhang dongli.zhang@oracle.com Cc: stable@vger.kernel.org Signed-off-by: Bart Van Assche bvanassche@acm.org --- block/blk-core.c | 12 ------------ 1 file changed, 12 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c index bfdbdbb8ec65..2921af6f8d33 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -348,18 +348,6 @@ void blk_cleanup_queue(struct request_queue *q)

blk_queue_flag_set(QUEUE_FLAG_DEAD, q);

- /* - * make sure all in-progress dispatch are completed because - * blk_freeze_queue() can only complete all requests, and - * dispatch may still be in-progress since we dispatch requests - * from more than one contexts. - * - * We rely on driver to deal with the race in case that queue - * initialization isn't done. - */ - if (queue_is_mq(q) && blk_queue_init_done(q)) - blk_mq_quiesce_queue(q); - /* for synchronous bio-based driver finish in-flight integrity i/o */ blk_flush_integrity();