Commit b93af305 authored by John Garry's avatar John Garry Committed by Jens Axboe
Browse files

blk-mq-sched: Fix blk_mq_sched_alloc_tags() error handling 



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: 6917ff0b ("blk-mq-sched: refactor scheduler initialization")
Signed-off-by: default avatarJohn Garry <john.garry@huawei.com>
Reviewed-by: default avatarMing Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/1627378373-148090-1-git-send-email-john.garry@huawei.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 3ce6e1f6

block/blk-mq-sched.c

+4 −13
Original line number Diff line number Diff line
@@ -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;

}