From 3280d66a6363af0df0441709bc0bc302bd9a2510 Mon Sep 17 00:00:00 2001 From: Keith Busch Date: Mon, 14 Aug 2017 16:40:11 -0400 Subject: [PATCH] blk-mq: Fix queue usage on failed request allocation 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 Reviewed-by: Ming Lei Reviewed-by: Sagi Grimberg Tested-by: Max Gurtovoy Signed-off-by: Keith Busch Signed-off-by: Jens Axboe --- 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 535cbdf32aab..4603b115e234 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);