From b48fda0976a802e0fe4fc0bedefb7cf380ec6426 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 26 Jan 2017 14:52:20 -0700 Subject: [PATCH] blk-mq-sched: check for successful allocation before assigning tag We don't trigger this from the normal IO path, since we always use blocking allocations from there. But Bart saw it testing multipath dm, since that is a heavy user of atomic request allocations in the map and clone path. Reported-by: Bart Van Assche Signed-off-by: Jens Axboe --- block/blk-mq-sched.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index 56b92db944ae..4cee060a292d 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -134,7 +134,8 @@ struct request *blk_mq_sched_get_request(struct request_queue *q, rq = __blk_mq_alloc_request(data, op); } else { rq = __blk_mq_alloc_request(data, op); - data->hctx->tags->rqs[rq->tag] = rq; + if (rq) + data->hctx->tags->rqs[rq->tag] = rq; } if (rq) { -- 2.20.1