From 47df9ce95cd568d3f84218c4f65e9fbd4dfeda55 Mon Sep 17 00:00:00 2001 From: Kemeng Shi Date: Wed, 18 Jan 2023 17:37:16 +0800 Subject: [PATCH] blk-mq: Fix potential io hung for shared sbitmap per tagset Commit f906a6a0f4268 ("blk-mq: improve tag waiting setup for non-shared tags") mark restart for unshared tags for improvement. At that time, tags is only shared betweens queues and we can check if tags is shared by test BLK_MQ_F_TAG_SHARED. Afterwards, commit 32bc15afed04b ("blk-mq: Facilitate a shared sbitmap per tagset") enabled tags share betweens hctxs inside a queue. We only mark restart for shared hctxs inside a queue and may cause io hung if there is no tag currently allocated by hctxs going to be marked restart. Wait on sbitmap_queue instead of mark restart for shared hctxs case to fix this. Fixes: 32bc15afed04 ("blk-mq: Facilitate a shared sbitmap per tagset") Signed-off-by: Kemeng Shi Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-mq.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index fa12f4e9310b..3ac732368866 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1831,7 +1831,8 @@ static bool blk_mq_mark_tag_wait(struct blk_mq_hw_ctx *hctx, wait_queue_entry_t *wait; bool ret; - if (!(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) { + if (!(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) && + !(blk_mq_is_shared_tags(hctx->flags))) { blk_mq_sched_mark_restart_hctx(hctx); /* @@ -2101,7 +2102,8 @@ out: bool needs_restart; /* For non-shared tags, the RESTART check will suffice */ bool no_tag = prep == PREP_DISPATCH_NO_TAG && - (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED); + ((hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) || + blk_mq_is_shared_tags(hctx->flags)); if (nr_budgets) blk_mq_release_budgets(q, list); -- 2.25.1