[PATCH 3/4] nvme: separate command prep and issue

Jens Axboe
2021-12-16T16:06:50Z

Add a nvme_prep_rq() helper to setup a command, and nvme_queue_rq() is
adapted to use this helper.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
drivers/nvme/host/pci.c | 57 ++++++++++++++++++++++++-----------------
1 file changed, 33 insertions(+), 24 deletions(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 09ea21f75439..6be6b1ab4285 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -918,52 +918,32 @@ static blk_status_t nvme_map_metadata(struct nvme_dev *dev, struct request *req,
return BLK_STS_OK;
}

-/*
- * NOTE: ns is NULL when called on the admin queue.
- */
-static blk_status_t nvme_queue_rq(struct blk_mq_hw_ctx *hctx,
- const struct blk_mq_queue_data *bd)
+static blk_status_t nvme_prep_rq(struct nvme_dev *dev, struct request *req)
{
- struct nvme_ns *ns = hctx->queue->queuedata;
- struct nvme_queue *nvmeq = hctx->driver_data;
- struct nvme_dev *dev = nvmeq->dev;
- struct request *req = bd->rq;
struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
- struct nvme_command *cmnd = &iod->cmd;
blk_status_t ret;

iod->aborted = 0;
iod->npages = -1;
iod->nents = 0;

- /*
- * We should not need to do this, but we're still using this to
- * ensure we can drain requests on a dying queue.
- */
- if (unlikely(!test_bit(NVMEQ_ENABLED, &nvmeq->flags)))
- return BLK_STS_IOERR;
-
- if (!nvme_check_ready(&dev->ctrl, req, true))
- return nvme_fail_nonready_command(&dev->ctrl, req);
-
- ret = nvme_setup_cmd(ns, req);
+ ret = nvme_setup_cmd(req->q->queuedata, req);
if (ret)
return ret;

if (blk_rq_nr_phys_segments(req)) {
- ret = nvme_map_data(dev, req, cmnd);
+ ret = nvme_map_data(dev, req, &iod->cmd);
if (ret)
goto out_free_cmd;
}

if (blk_integrity_rq(req)) {
- ret = nvme_map_metadata(dev, req, cmnd);
+ ret = nvme_map_metadata(dev, req, &iod->cmd);
if (ret)
goto out_unmap_data;
}

blk_mq_start_request(req);
- nvme_submit_cmd(nvmeq, cmnd, bd->last);
return BLK_STS_OK;
out_unmap_data:
nvme_unmap_data(dev, req);
@@ -972,6 +952,35 @@ static blk_status_t nvme_queue_rq(struct blk_mq_hw_ctx *hctx,
return ret;
}

+/*
+ * NOTE: ns is NULL when called on the admin queue.
+ */
+static blk_status_t nvme_queue_rq(struct blk_mq_hw_ctx *hctx,
+ const struct blk_mq_queue_data *bd)
+{
+ struct nvme_queue *nvmeq = hctx->driver_data;
+ struct nvme_dev *dev = nvmeq->dev;
+ struct request *req = bd->rq;
+ struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
+ blk_status_t ret;
+
+ /*
+ * We should not need to do this, but we're still using this to
+ * ensure we can drain requests on a dying queue.
+ */
+ if (unlikely(!test_bit(NVMEQ_ENABLED, &nvmeq->flags)))
+ return BLK_STS_IOERR;
+
+ if (unlikely(!nvme_check_ready(&dev->ctrl, req, true)))
+ return nvme_fail_nonready_command(&dev->ctrl, req);
+
+ ret = nvme_prep_rq(dev, req);
+ if (unlikely(ret))
+ return ret;
+ nvme_submit_cmd(nvmeq, &iod->cmd, bd->last);
+ return BLK_STS_OK;