From: Kemeng Shi Date: Wed, 18 Jan 2023 09:37:15 +0000 (+0800) Subject: blk-mq: wait on correct sbitmap_queue in blk_mq_mark_tag_wait X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=98b99e9412d0cde8c7b442bf5efb09528a2ede8b;p=linux.git blk-mq: wait on correct sbitmap_queue in blk_mq_mark_tag_wait For shared queues case, we will only wait on bitmap_tags if we fail to get driver tag. However, rq could be from breserved_tags, then two problems will occur: 1. io hung if no tag is currently allocated from bitmap_tags. 2. unnecessary wakeup when tag is freed to bitmap_tags while no tag is freed to breserved_tags. Wait on the bitmap which rq from to fix this. Fixes: f906a6a0f426 ("blk-mq: improve tag waiting setup for non-shared tags") Reviewed-by: Christoph Hellwig Signed-off-by: Kemeng Shi Signed-off-by: Jens Axboe --- diff --git a/block/blk-mq.c b/block/blk-mq.c index 351f160bf6919..fa12f4e9310b8 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1826,7 +1826,7 @@ static int blk_mq_dispatch_wake(wait_queue_entry_t *wait, unsigned mode, static bool blk_mq_mark_tag_wait(struct blk_mq_hw_ctx *hctx, struct request *rq) { - struct sbitmap_queue *sbq = &hctx->tags->bitmap_tags; + struct sbitmap_queue *sbq; struct wait_queue_head *wq; wait_queue_entry_t *wait; bool ret; @@ -1849,6 +1849,10 @@ static bool blk_mq_mark_tag_wait(struct blk_mq_hw_ctx *hctx, if (!list_empty_careful(&wait->entry)) return false; + if (blk_mq_tag_is_reserved(rq->mq_hctx->sched_tags, rq->internal_tag)) + sbq = &hctx->tags->breserved_tags; + else + sbq = &hctx->tags->bitmap_tags; wq = &bt_wait_ptr(sbq, hctx)->wait; spin_lock_irq(&wq->lock);