nvme: split nvme status from block req->errors

We want our own clearly defined error field for NVMe passthrough commands,
and the request errors field is going away in its current form.

Just store the status and result field in the nvme_request field from
hardirq completion context (using a new helper) and then generate a
Linux errno for the block layer only when we actually need it.

Because we can't overload the status value with a negative error code
for cancelled command we now have a flags filed in struct nvme_request
that contains a bit for this condition.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 31 insertions, 19 deletions

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index d33f829c3ab7..c6f256d74b6b 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -66,11 +66,24 @@ static DEFINE_SPINLOCK(dev_list_lock);
 
 static struct class *nvme_class;
 
+int nvme_error_status(struct request *req)
+{
+	switch (nvme_req(req)->status & 0x7ff) {
+	case NVME_SC_SUCCESS:
+		return 0;
+	case NVME_SC_CAP_EXCEEDED:
+		return -ENOSPC;
+	default:
+		return -EIO;
+	}
+}
+EXPORT_SYMBOL_GPL(nvme_error_status);
+
 static inline bool nvme_req_needs_retry(struct request *req)
 {
 	if (blk_noretry_request(req))
 		return false;
-	if (req->errors & NVME_SC_DNR)
+	if (nvme_req(req)->status & NVME_SC_DNR)
 		return false;
 	if (jiffies - req->start_time >= req->timeout)
 		return false;
@@ -81,23 +94,13 @@ static inline bool nvme_req_needs_retry(struct request *req)
 
 void nvme_complete_rq(struct request *req)
 {
-	int error = 0;
-
-	if (unlikely(req->errors)) {
-		if (nvme_req_needs_retry(req)) {
-			nvme_req(req)->retries++;
-			blk_mq_requeue_request(req,
-					!blk_mq_queue_stopped(req->q));
-			return;
-		}
-
-		if (blk_rq_is_passthrough(req))
-			error = req->errors;
-		else
-			error = nvme_error_status(req->errors);
+	if (unlikely(nvme_req(req)->status && nvme_req_needs_retry(req))) {
+		nvme_req(req)->retries++;
+		blk_mq_requeue_request(req, !blk_mq_queue_stopped(req->q));
+		return;
 	}
 
-	blk_mq_end_request(req, error);
+	blk_mq_end_request(req, nvme_error_status(req));
 }
 EXPORT_SYMBOL_GPL(nvme_complete_rq);
 
@@ -114,7 +117,9 @@ void nvme_cancel_request(struct request *req, void *data, bool reserved)
 	status = NVME_SC_ABORT_REQ;
 	if (blk_queue_dying(req->q))
 		status |= NVME_SC_DNR;
-	blk_mq_complete_request(req, status);
+	nvme_req(req)->status = status;
+	blk_mq_complete_request(req, 0);
+
 }
 EXPORT_SYMBOL_GPL(nvme_cancel_request);
 
@@ -357,6 +362,7 @@ int nvme_setup_cmd(struct nvme_ns *ns, struct request *req,
 
 	if (!(req->rq_flags & RQF_DONTPREP)) {
 		nvme_req(req)->retries = 0;
+		nvme_req(req)->flags = 0;
 		req->rq_flags |= RQF_DONTPREP;
 	}
 
@@ -413,7 +419,10 @@ int __nvme_submit_sync_cmd(struct request_queue *q, struct nvme_command *cmd,
 	blk_execute_rq(req->q, NULL, req, at_head);
 	if (result)
 		*result = nvme_req(req)->result;
-	ret = req->errors;
+	if (nvme_req(req)->flags & NVME_REQ_CANCELLED)
+		ret = -EINTR;
+	else
+		ret = nvme_req(req)->status;
  out:
 	blk_mq_free_request(req);
 	return ret;
@@ -498,7 +507,10 @@ int __nvme_submit_user_cmd(struct request_queue *q, struct nvme_command *cmd,
 	}
  submit:
 	blk_execute_rq(req->q, disk, req, 0);
-	ret = req->errors;
+	if (nvme_req(req)->flags & NVME_REQ_CANCELLED)
+		ret = -EINTR;
+	else
+		ret = nvme_req(req)->status;
 	if (result)
 		*result = le32_to_cpu(nvme_req(req)->result.u32);
 	if (meta && !ret && !write) {