Commit 9515743b authored Feb 26, 2020 by Bijan Mottahedeh Committed by Keith Busch Feb 28, 2020

nvme-pci: Hold cq_poll_lock while completing CQEs

Completions need to consumed in the same order the controller submitted
them, otherwise future completion entries may overwrite ones we haven't
handled yet. Hold the nvme queue's poll lock while completing new CQEs to
prevent another thread from freeing command tags for reuse out-of-order.

Fixes: dabcefab ("nvme: provide optimized poll function for separate poll queues")
Signed-off-by: Bijan Mottahedeh <bijan.mottahedeh@oracle.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Keith Busch <kbusch@kernel.org>

parent cae740a0

drivers/nvme/host/pci.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1078,9 +1078,9 @@ static int nvme_poll(struct blk_mq_hw_ctx *hctx)

		spin_lock(&nvmeq->cq_poll_lock);
		found = nvme_process_cq(nvmeq, &start, &end, -1);
		nvme_complete_cqes(nvmeq, start, end);
		spin_unlock(&nvmeq->cq_poll_lock);

		nvme_complete_cqes(nvmeq, start, end);
		return found;
		}

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