nvmet: Remove the data_len field from the nvmet_req struct

Instead of storing the expected length and checking it when it's
executed, just check the length inside the command themselves.

A new helper, nvmet_check_data_len() is created to help with this
check.

Signed-off-by: Christoph Hellwig <hch@lst.de>
[split patch, udpate changelog]
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 12 insertions, 4 deletions

diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index 6b39cfc6ade1..565def19d593 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -930,13 +930,21 @@ void nvmet_req_uninit(struct nvmet_req *req)
 }
 EXPORT_SYMBOL_GPL(nvmet_req_uninit);
 
-void nvmet_req_execute(struct nvmet_req *req)
+bool nvmet_check_data_len(struct nvmet_req *req, size_t data_len)
 {
-	if (unlikely(req->data_len != req->transfer_len)) {
+	if (unlikely(data_len != req->transfer_len)) {
 		req->error_loc = offsetof(struct nvme_common_command, dptr);
 		nvmet_req_complete(req, NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR);
-	} else
-		req->execute(req);
+		return false;
+	}
+
+	return true;
+}
+EXPORT_SYMBOL_GPL(nvmet_check_data_len);
+
+void nvmet_req_execute(struct nvmet_req *req)
+{
+	req->execute(req);
 }
 EXPORT_SYMBOL_GPL(nvmet_req_execute);