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author | Kemeng Shi <shikemeng@huaweicloud.com> | 2023-01-18 17:37:13 +0800 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-03-10 09:32:43 +0100 |
commit | 14cea6cc8ad3c031394da8c7c1468555fe9ee47e (patch) | |
tree | b53f47ad6282abf4f0c3ffc9d0dcbd47ed25e6b2 /block | |
parent | 76e64c9a0a8220957b81a741de0a1c85e0e85494 (diff) | |
download | linux-14cea6cc8ad3c031394da8c7c1468555fe9ee47e.tar.gz |
blk-mq: avoid sleep in blk_mq_alloc_request_hctx
[ Upstream commit 6ee858a3d3270a68902d66bb47c151a83622535c ] Commit 1f5bd336b9150 ("blk-mq: add blk_mq_alloc_request_hctx") add blk_mq_alloc_request_hctx to send commands to a specific queue. If BLK_MQ_REQ_NOWAIT is not set in tag allocation, we may change to different hctx after sleep and get tag from unexpected hctx. So BLK_MQ_REQ_NOWAIT must be set in flags for blk_mq_alloc_request_hctx. After commit 600c3b0cea784 ("blk-mq: open code __blk_mq_alloc_request in blk_mq_alloc_request_hctx"), blk_mq_alloc_request_hctx return -EINVAL if both BLK_MQ_REQ_NOWAIT and BLK_MQ_REQ_RESERVED are not set instead of if BLK_MQ_REQ_NOWAIT is not set. So if BLK_MQ_REQ_NOWAIT is not set and BLK_MQ_REQ_RESERVED is set, blk_mq_alloc_request_hctx could alloc tag from unexpected hctx. I guess what we need here is that return -EINVAL if either BLK_MQ_REQ_NOWAIT or BLK_MQ_REQ_RESERVED is not set. Currently both BLK_MQ_REQ_NOWAIT and BLK_MQ_REQ_RESERVED will be set if specific hctx is needed in nvme_auth_submit, nvmf_connect_io_queue and nvmf_connect_admin_queue. Fix the potential BLK_MQ_REQ_NOWAIT missed case in future. Fixes: 600c3b0cea78 ("blk-mq: open code __blk_mq_alloc_request in blk_mq_alloc_request_hctx") Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'block')
-rw-r--r-- | block/blk-mq.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index 83fbc7c54617..2983ace81266 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -626,7 +626,8 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q, * allocator for this for the rare use case of a command tied to * a specific queue. */ - if (WARN_ON_ONCE(!(flags & (BLK_MQ_REQ_NOWAIT | BLK_MQ_REQ_RESERVED)))) + if (WARN_ON_ONCE(!(flags & BLK_MQ_REQ_NOWAIT)) || + WARN_ON_ONCE(!(flags & BLK_MQ_REQ_RESERVED))) return ERR_PTR(-EINVAL); if (hctx_idx >= q->nr_hw_queues) |