From b175c86739d38e41044d3136065f092a6d95aee6 Mon Sep 17 00:00:00 2001 From: Chengming Zhou Date: Mon, 17 Jul 2023 12:00:57 +0800 Subject: [PATCH] blk-flush: count inflight flush_data requests The flush state machine use a double list to link all inflight flush_data requests, to avoid issuing separate post-flushes for these flush_data requests which shared PREFLUSH. So we can't reuse rq->queuelist, this is why we need rq->flush.list In preparation of the next patch that reuse rq->queuelist for flush state machine, we change the double linked list to unsigned long counter, which count all inflight flush_data requests. This is ok since we only need to know if there is any inflight flush_data request, so unsigned long counter is good. Signed-off-by: Chengming Zhou Reviewed-by: Ming Lei Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20230717040058.3993930-4-chengming.zhou@linux.dev Signed-off-by: Jens Axboe --- block/blk-flush.c | 9 +++++---- block/blk.h | 5 ++--- 2 files changed, 7 insertions(+), 7 deletions(-) diff --git a/block/blk-flush.c b/block/blk-flush.c index fdc489e0ea16..fedb39031647 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -187,7 +187,8 @@ static void blk_flush_complete_seq(struct request *rq, break; case REQ_FSEQ_DATA: - list_move_tail(&rq->flush.list, &fq->flush_data_in_flight); + list_del_init(&rq->flush.list); + fq->flush_data_in_flight++; spin_lock(&q->requeue_lock); list_add(&rq->queuelist, &q->requeue_list); spin_unlock(&q->requeue_lock); @@ -299,7 +300,7 @@ static void blk_kick_flush(struct request_queue *q, struct blk_flush_queue *fq, return; /* C2 and C3 */ - if (!list_empty(&fq->flush_data_in_flight) && + if (fq->flush_data_in_flight && time_before(jiffies, fq->flush_pending_since + FLUSH_PENDING_TIMEOUT)) return; @@ -374,6 +375,7 @@ static enum rq_end_io_ret mq_flush_data_end_io(struct request *rq, * the comment in flush_end_io(). */ spin_lock_irqsave(&fq->mq_flush_lock, flags); + fq->flush_data_in_flight--; blk_flush_complete_seq(rq, fq, REQ_FSEQ_DATA, error); spin_unlock_irqrestore(&fq->mq_flush_lock, flags); @@ -445,7 +447,7 @@ bool blk_insert_flush(struct request *rq) blk_rq_init_flush(rq); rq->flush.seq |= REQ_FSEQ_PREFLUSH; spin_lock_irq(&fq->mq_flush_lock); - list_move_tail(&rq->flush.list, &fq->flush_data_in_flight); + fq->flush_data_in_flight++; spin_unlock_irq(&fq->mq_flush_lock); return false; default: @@ -496,7 +498,6 @@ struct blk_flush_queue *blk_alloc_flush_queue(int node, int cmd_size, INIT_LIST_HEAD(&fq->flush_queue[0]); INIT_LIST_HEAD(&fq->flush_queue[1]); - INIT_LIST_HEAD(&fq->flush_data_in_flight); return fq; diff --git a/block/blk.h b/block/blk.h index 608c5dcc516b..686712e13835 100644 --- a/block/blk.h +++ b/block/blk.h @@ -15,15 +15,14 @@ struct elevator_type; extern struct dentry *blk_debugfs_root; struct blk_flush_queue { + spinlock_t mq_flush_lock; unsigned int flush_pending_idx:1; unsigned int flush_running_idx:1; blk_status_t rq_status; unsigned long flush_pending_since; struct list_head flush_queue[2]; - struct list_head flush_data_in_flight; + unsigned long flush_data_in_flight; struct request *flush_rq; - - spinlock_t mq_flush_lock; }; bool is_flush_rq(struct request *req); -- 2.11.0