| Message ID | 20221223125223.1687670-2-shikemeng@huaweicloud.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | A few bugfix and cleanup patches for blk-mq | expand |
On Fri, Dec 23, 2022 at 08:52:11PM +0800, Kemeng Shi wrote:
> + if (WARN_ON_ONCE(((!flags) & (BLK_MQ_REQ_NOWAIT | BLK_MQ_REQ_RESERVED))))
This check does not make any sense. I think what you want is
if (WARN_ON_ONCE(!(flags & BLK_MQ_REQ_NOWAIT) ||
WARN_ON_ONCE(!(flags & BLK_MQ_REQ_RESERVED))))
Hi, Christoph. on 12/23/2022 1:37 PM, Christoph Hellwig wrote: > On Fri, Dec 23, 2022 at 08:52:11PM +0800, Kemeng Shi wrote: >> + if (WARN_ON_ONCE(((!flags) & (BLK_MQ_REQ_NOWAIT | BLK_MQ_REQ_RESERVED)))) > > This check does not make any sense. I think what you want is > > if (WARN_ON_ONCE(!(flags & BLK_MQ_REQ_NOWAIT) || > WARN_ON_ONCE(!(flags & BLK_MQ_REQ_RESERVED)))) This is exactly what I want and I will fix this in next version. Thanks.
diff --git a/block/blk-mq.c b/block/blk-mq.c index 4e6b3ccd4989..988812811db9 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -657,7 +657,7 @@ 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 | BLK_MQ_REQ_RESERVED)))) return ERR_PTR(-EINVAL); if (hctx_idx >= q->nr_hw_queues)
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") Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> --- block/blk-mq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)