From: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Date: Tue, 9 Feb 2021 21:48:01 -0800
Subject: nvmet: add nvmet_req_subsys() helper
Patch-mainline: v5.12-rc1
Git-commit: 20c2c3bb83f26c42bf62cc773f96f30848ed11a2
References: bsc#1192761

Just like what we have to get the passthru ctrl from the req, add an
helper to get the subsystem associated with the nvmet_req() instead
of open coding the chain of structures.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Daniel Wagner <dwagner@suse.de>
---
 drivers/nvme/target/admin-cmd.c |   10 +++++-----
 drivers/nvme/target/nvmet.h     |    7 ++++++-
 2 files changed, 11 insertions(+), 6 deletions(-)

--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -692,7 +692,7 @@ static u16 nvmet_write_protect_flush_syn
 static u16 nvmet_set_feat_write_protect(struct nvmet_req *req)
 {
 	u32 write_protect = le32_to_cpu(req->cmd->common.cdw11);
-	struct nvmet_subsys *subsys = req->sq->ctrl->subsys;
+	struct nvmet_subsys *subsys = nvmet_req_subsys(req);
 	u16 status = NVME_SC_FEATURE_NOT_CHANGEABLE;
 
 	req->ns = nvmet_find_namespace(req->sq->ctrl, req->cmd->rw.nsid);
@@ -751,7 +751,7 @@ u16 nvmet_set_feat_async_event(struct nv
 
 void nvmet_execute_set_features(struct nvmet_req *req)
 {
-	struct nvmet_subsys *subsys = req->sq->ctrl->subsys;
+	struct nvmet_subsys *subsys = nvmet_req_subsys(req);
 	u32 cdw10 = le32_to_cpu(req->cmd->common.cdw10);
 	u32 cdw11 = le32_to_cpu(req->cmd->common.cdw11);
 	u16 status = 0;
@@ -795,7 +795,7 @@ void nvmet_execute_set_features(struct n
 
 static u16 nvmet_get_feat_write_protect(struct nvmet_req *req)
 {
-	struct nvmet_subsys *subsys = req->sq->ctrl->subsys;
+	struct nvmet_subsys *subsys = nvmet_req_subsys(req);
 	u32 result;
 
 	req->ns = nvmet_find_namespace(req->sq->ctrl, req->cmd->common.nsid);
@@ -826,7 +826,7 @@ void nvmet_get_feat_async_event(struct n
 
 void nvmet_execute_get_features(struct nvmet_req *req)
 {
-	struct nvmet_subsys *subsys = req->sq->ctrl->subsys;
+	struct nvmet_subsys *subsys = nvmet_req_subsys(req);
 	u32 cdw10 = le32_to_cpu(req->cmd->common.cdw10);
 	u16 status = 0;
 
@@ -933,7 +933,7 @@ u16 nvmet_parse_admin_cmd(struct nvmet_r
 
 	if (nvme_is_fabrics(cmd))
 		return nvmet_parse_fabrics_cmd(req);
-	if (req->sq->ctrl->subsys->type == NVME_NQN_DISC)
+	if (nvmet_req_subsys(req)->type == NVME_NQN_DISC)
 		return nvmet_parse_discovery_cmd(req);
 
 	ret = nvmet_check_ctrl_status(req, cmd);
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -547,6 +547,11 @@ static inline u32 nvmet_dsm_len(struct n
 		sizeof(struct nvme_dsm_range);
 }
 
+static inline struct nvmet_subsys *nvmet_req_subsys(struct nvmet_req *req)
+{
+	return req->sq->ctrl->subsys;
+}
+
 #ifdef CONFIG_NVME_TARGET_PASSTHRU
 void nvmet_passthru_subsys_free(struct nvmet_subsys *subsys);
 int nvmet_passthru_ctrl_enable(struct nvmet_subsys *subsys);
@@ -581,7 +586,7 @@ static inline struct nvme_ctrl *nvmet_pa
 static inline struct nvme_ctrl *
 nvmet_req_passthru_ctrl(struct nvmet_req *req)
 {
-	return nvmet_passthru_ctrl(req->sq->ctrl->subsys);
+	return nvmet_passthru_ctrl(nvmet_req_subsys(req));
 }
 
 u16 errno_to_nvme_status(struct nvmet_req *req, int errno);