[PATCH] nvme-pci: check for valid request when polling for completions

[Hannes Reinecke <hare@kernel.org>]

When polling for completions from the timeout handler we traverse
over _all_ cqes, and the fetching the request via blk_mq_tag_to_rq().
Unfortunately that function will always return a request, even if
that request is already completed.
So we need to check if the command is still in flight before
attempting to complete it.

Signed-off-by: Hannes Reinecke <hare@kernel.org>
---
 drivers/nvme/host/pci.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 6cd9395ba9ec..fc4c616516d6 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1037,6 +1037,13 @@ static inline void nvme_handle_cqe(struct nvme_queue *nvmeq,
 		return;
 	}
 
+	if (blk_mq_rq_state(req) != MQ_RQ_IN_FLIGHT) {
+		dev_warn(nvmeq->dev->ctrl.device,
+			 "stale completion id %d on queue %d\n",
+			 command_id, le16_to_cpu(cqe->sq_id));
+		return;
+	}
+
 	trace_nvme_sq(req, cqe->sq_head, nvmeq->sq_tail);
 	if (!nvme_try_complete_req(req, cqe->status, cqe->result) &&
 	    !blk_mq_add_to_batch(req, iob, nvme_req(req)->status,
-- 
2.35.3