[PATCH] nvme: make prp passthrough usage less scary

[Keith Busch]

From: Keith Busch <kbusch at kernel.org>

The warning is a bit alarming, and it only prints for the very first
non-sgl capable device that receives a passthrough command. Just log an
informational message on initial discovery for every device.

Signed-off-by: Keith Busch <kbusch at kernel.org>
---
 drivers/nvme/host/core.c  |  4 ++++
 drivers/nvme/host/ioctl.c | 12 ++----------
 2 files changed, 6 insertions(+), 10 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index dc388e24caade..1e7e42b43aa3f 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3749,6 +3749,10 @@ int nvme_init_ctrl_finish(struct nvme_ctrl *ctrl, bool was_suspended)
 		ret = nvme_hwmon_init(ctrl);
 		if (ret == -EINTR)
 			return ret;
+
+		if (!nvme_ctrl_sgl_supported(ctrl))
+			dev_info(ctrl->device,
+				"passthrough uses implicit buffer lengths\n");
 	}
 
 	clear_bit(NVME_CTRL_DIRTY_CAPABILITY, &ctrl->flags);
diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c
index 9597a87cf05dc..39d6e69cbbe72 100644
--- a/drivers/nvme/host/ioctl.c
+++ b/drivers/nvme/host/ioctl.c
@@ -125,16 +125,8 @@ static int nvme_map_user_request(struct request *req, u64 ubuffer,
 	struct bio *bio = NULL;
 	int ret;
 
-	if (!nvme_ctrl_sgl_supported(ctrl))
-		dev_warn_once(ctrl->device, "using unchecked data buffer\n");
-	if (has_metadata) {
-		if (!supports_metadata)
-			return -EINVAL;
-
-		if (!nvme_ctrl_meta_sgl_supported(ctrl))
-			dev_warn_once(ctrl->device,
-				      "using unchecked metadata buffer\n");
-	}
+	if (has_metadata && !supports_metadata)
+		return -EINVAL;
 
 	if (iter)
 		ret = blk_rq_map_user_iov(q, req, NULL, iter, GFP_KERNEL);
-- 
2.52.0