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From: John Garry <john.garry@huawei.com>
To: <axboe@kernel.dk>
Cc: <osandov@fb.com>, <linux-block@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>, <ming.lei@redhat.com>,
	John Garry <john.garry@huawei.com>
Subject: [PATCH] blk-mq-sched: Fix blk_mq_sched_alloc_tags() error handling
Date: Tue, 27 Jul 2021 17:32:53 +0800	[thread overview]
Message-ID: <1627378373-148090-1-git-send-email-john.garry@huawei.com> (raw)

If the blk_mq_sched_alloc_tags() -> blk_mq_alloc_rqs() call fails, then we
call blk_mq_sched_free_tags() -> blk_mq_free_rqs().

It is incorrect to do so, as any rqs would have already been freed in the
blk_mq_alloc_rqs() call.

Fix by calling blk_mq_free_rq_map() only directly.

Fixes: 6917ff0b5bd41 ("blk-mq-sched: refactor scheduler initialization")
Signed-off-by: John Garry <john.garry@huawei.com>

diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index c838d81ac058..0f006cabfd91 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -515,17 +515,6 @@ void blk_mq_sched_insert_requests(struct blk_mq_hw_ctx *hctx,
 	percpu_ref_put(&q->q_usage_counter);
 }
 
-static void blk_mq_sched_free_tags(struct blk_mq_tag_set *set,
-				   struct blk_mq_hw_ctx *hctx,
-				   unsigned int hctx_idx)
-{
-	if (hctx->sched_tags) {
-		blk_mq_free_rqs(set, hctx->sched_tags, hctx_idx);
-		blk_mq_free_rq_map(hctx->sched_tags, set->flags);
-		hctx->sched_tags = NULL;
-	}
-}
-
 static int blk_mq_sched_alloc_tags(struct request_queue *q,
 				   struct blk_mq_hw_ctx *hctx,
 				   unsigned int hctx_idx)
@@ -539,8 +528,10 @@ static int blk_mq_sched_alloc_tags(struct request_queue *q,
 		return -ENOMEM;
 
 	ret = blk_mq_alloc_rqs(set, hctx->sched_tags, hctx_idx, q->nr_requests);
-	if (ret)
-		blk_mq_sched_free_tags(set, hctx, hctx_idx);
+	if (ret) {
+		blk_mq_free_rq_map(hctx->sched_tags, set->flags);
+		hctx->sched_tags = NULL;
+	}
 
 	return ret;
 }
-- 
2.26.2


             reply	other threads:[~2021-07-27  9:37 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-27  9:32 John Garry [this message]
2021-07-27 10:06 ` [PATCH] blk-mq-sched: Fix blk_mq_sched_alloc_tags() error handling Ming Lei
2021-07-27 10:30   ` John Garry
2021-07-27 10:43     ` Ming Lei
2021-07-27 22:44 ` Jens Axboe

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