[PATCH] blk-mq: Fix queue usage on failed request allocation
From: Keith Busch <hidden>
Date: 2017-08-14 20:40:11
Also in:
linux-nvme
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
blk_mq_get_request() does not release the callers queue usage counter
when allocation fails. The caller still needs to account for its own
queue usage when it is unable to allocate a request.
Fixes: 1ad43c0078b7 ("blk-mq: don't leak preempt counter/q_usage_counter when allocating rq failed")
Reported-by: Max Gurtovoy <redacted>
Signed-off-by: Keith Busch <redacted>
---
block/blk-mq.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 535cbdf..4603b11 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c@@ -360,12 +360,12 @@ struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op, return ERR_PTR(ret); rq = blk_mq_get_request(q, NULL, op, &alloc_data); + blk_queue_exit(q); if (!rq) return ERR_PTR(-EWOULDBLOCK); blk_mq_put_ctx(alloc_data.ctx); - blk_queue_exit(q); rq->__data_len = 0; rq->__sector = (sector_t) -1;
@@ -411,12 +411,11 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q, alloc_data.ctx = __blk_mq_get_ctx(q, cpu); rq = blk_mq_get_request(q, NULL, op, &alloc_data); + blk_queue_exit(q); if (!rq) return ERR_PTR(-EWOULDBLOCK); - blk_queue_exit(q); - return rq; } EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx);
--
2.5.5