On Sun, Apr 16, 2023 at 02:01:30PM -0700, Bart Van Assche wrote: > On 4/16/23 13:09, Christoph Hellwig wrote: >> diff --git a/block/blk-flush.c b/block/blk-flush.c >> index 69e9806f575455..231d3780e74ad1 100644 >> --- a/block/blk-flush.c >> +++ b/block/blk-flush.c >> @@ -188,7 +188,9 @@ static void blk_flush_complete_seq(struct request *rq, >> case REQ_FSEQ_DATA: >> list_move_tail(&rq->flush.list, &fq->flush_data_in_flight); >> - blk_mq_add_to_requeue_list(rq, 0); >> + spin_lock(&q->requeue_lock); >> + list_add_tail(&rq->queuelist, &q->flush_list); >> + spin_unlock(&q->requeue_lock); >> blk_mq_kick_requeue_list(q); >> break; > > At least the SCSI core can call blk_flush_complete_seq() from interrupt > context so I don't think the above code is correct. The call chain is as > follows: All callers of blk_flush_complete_seq already disable interrupts when taking mq_flush_lock. No need to disable interrupts again for a nested lock then.
