blk-mq: remove unnecessary list_empty check in blk_mq_try_issue_list_directly

We only break the list walk if we get 'BLK_STS_*RESOURCE'. We also
count errors for 'BLK_STS_*RESOURCE' error. If list is not empty,
errors will always be non-zero. So we can remove unnecessary list_empty
check. This will remove redundant list_empty check for case that
error happened at sending last request in list.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 3ac7323..b764bdd 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2839,8 +2839,7 @@ void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
         * the driver there was more coming, but that turned out to
         * be a lie.
         */
-       if ((!list_empty(list) || errors) &&
-            hctx->queue->mq_ops->commit_rqs && queued)
+       if (errors && hctx->queue->mq_ops->commit_rqs && queued)
                hctx->queue->mq_ops->commit_rqs(hctx);
 }