[PATCH 1/6] nvme: move the dying queue check from cancel to completion

Christoph Hellwig
2017-11-02T18:28:51Z

With multipath we don't want a hard DNR bit on a request that is cancelled
by a controller reset, but instead want to be able to retry it on another
patch. To archive this don't always set the DNR bit when the queue is
dying in nvme_cancel_request, but defer that decision to
nvme_req_needs_retry. Note that it applies to any command there and not
just cancelled commands, but one the queue is dying that is the right
thing to do anyway.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/nvme/host/core.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 07b9f4e1c283..1c2686d4eaf3 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -172,6 +172,8 @@ static inline bool nvme_req_needs_retry(struct request *req)
return false;
if (nvme_req(req)->retries >= nvme_max_retries)
return false;
+ if (blk_queue_dying(req->q))
+ return false;
return true;
}

@@ -189,18 +191,13 @@ EXPORT_SYMBOL_GPL(nvme_complete_rq);

void nvme_cancel_request(struct request *req, void *data, bool reserved)
{
- int status;
-
if (!blk_mq_request_started(req))
return;

dev_dbg_ratelimited(((struct nvme_ctrl *) data)->device,
"Cancelling I/O %d", req->tag);

- status = NVME_SC_ABORT_REQ;
- if (blk_queue_dying(req->q))
- status |= NVME_SC_DNR;
- nvme_req(req)->status = status;
+ nvme_req(req)->status = NVME_SC_ABORT_REQ;
blk_mq_complete_request(req);

}
--
2.14.2