[PATCH 2/2] nvme: avoid memset for passthrough requests

[Kanchan Joshi]

nvme_clear_nvme_request() clears the nvme_command, which is unncessary for
passthrough requests as nvme_command is overwritten immediately.
Change nvme_clear_nvme_request() so that double memset for passthrough
requests is avoided.

Signed-off-by: Kanchan Joshi <joshi.k at samsung.com>
---
 drivers/nvme/host/core.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index ea5b40e469d6..5f6b742aa32c 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -583,14 +583,13 @@ void nvme_put_ns(struct nvme_ns *ns)
 }
 EXPORT_SYMBOL_NS_GPL(nvme_put_ns, NVME_TARGET_PASSTHRU);
 
-static inline void nvme_clear_nvme_request(struct request *req)
+static inline void nvme_clear_nvme_request(struct request *req, bool clear_cmd)
 {
-	struct nvme_command *cmd = nvme_req(req)->cmd;
-
-	memset(cmd, 0, sizeof(*cmd));
 	nvme_req(req)->retries = 0;
 	nvme_req(req)->flags = 0;
 	req->rq_flags |= RQF_DONTPREP;
+	if (clear_cmd)
+		memset(nvme_req(req)->cmd, 0, sizeof(struct nvme_command));
 }
 
 static inline unsigned int nvme_req_op(struct nvme_command *cmd)
@@ -610,7 +609,7 @@ static inline void nvme_init_request(struct request *req,
 	cmd->common.flags &= ~NVME_CMD_SGL_ALL;
 
 	req->cmd_flags |= REQ_FAILFAST_DRIVER;
-	nvme_clear_nvme_request(req);
+	nvme_clear_nvme_request(req, false);
 	memcpy(nvme_req(req)->cmd, cmd, sizeof(*cmd));
 }
 
@@ -900,7 +899,7 @@ blk_status_t nvme_setup_cmd(struct nvme_ns *ns, struct request *req)
 	blk_status_t ret = BLK_STS_OK;
 
 	if (!(req->rq_flags & RQF_DONTPREP))
-		nvme_clear_nvme_request(req);
+		nvme_clear_nvme_request(req, true);
 
 	switch (req_op(req)) {
 	case REQ_OP_DRV_IN:
-- 
2.25.1