[PATCH V2 1/4] nvmet: change the type of the ns->readonly

[Chaitanya Kulkarni]

In this patch, we change the type of the ns->readonly attribute from
bool to the nvme_ns_wp_state and rename it to write_protect so that we
can actually store the state of the ns write protection. This is needed
to store the ns write protection permanent state since in the next patch
we allow user to set the write protection from the configfs ns attr to
export the read-only snapshots such that host should not change the write
protect value when it is set to permanent from configfs.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni at wdc.com>
---
 drivers/nvme/target/admin-cmd.c | 27 ++++++++++++++++-----------
 drivers/nvme/target/core.c      |  3 ++-
 drivers/nvme/target/nvmet.h     |  2 +-
 include/linux/nvme.h            |  2 +-
 4 files changed, 20 insertions(+), 14 deletions(-)

diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index dca34489a1dc..263cfff6ddd4 100644
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -537,8 +537,17 @@ static void nvmet_execute_identify_ns(struct nvmet_req *req)
 		id->lbaf[0].ms = cpu_to_le16(ns->metadata_size);
 	}
 
-	if (ns->readonly)
+	switch (ns->write_protect) {
+	case NVME_NS_NO_WRITE_PROTECT:
+		id->nsattr |= 0;
+		break;
+	case NVME_NS_WRITE_PROTECT:
 		id->nsattr |= (1 << 0);
+		break;
+	default:
+		break;
+	}
+
 	nvmet_put_namespace(ns);
 done:
 	status = nvmet_copy_to_sgl(req, 0, id, sizeof(*id));
@@ -704,13 +713,14 @@ static u16 nvmet_set_feat_write_protect(struct nvmet_req *req)
 	mutex_lock(&subsys->lock);
 	switch (write_protect) {
 	case NVME_NS_WRITE_PROTECT:
-		req->ns->readonly = true;
 		status = nvmet_write_protect_flush_sync(req);
-		if (status)
-			req->ns->readonly = false;
+		if (status == NVME_SC_SUCCESS)
+			req->ns->write_protect = NVME_NS_WRITE_PROTECT;
+		else
+			req->ns->write_protect = NVME_NS_NO_WRITE_PROTECT;
 		break;
 	case NVME_NS_NO_WRITE_PROTECT:
-		req->ns->readonly = false;
+		req->ns->write_protect = NVME_NS_NO_WRITE_PROTECT;
 		status = 0;
 		break;
 	default:
@@ -798,7 +808,6 @@ void nvmet_execute_set_features(struct nvmet_req *req)
 static u16 nvmet_get_feat_write_protect(struct nvmet_req *req)
 {
 	struct nvmet_subsys *subsys = req->sq->ctrl->subsys;
-	u32 result;
 
 	req->ns = nvmet_find_namespace(req->sq->ctrl, req->cmd->common.nsid);
 	if (!req->ns)  {
@@ -806,11 +815,7 @@ static u16 nvmet_get_feat_write_protect(struct nvmet_req *req)
 		return NVME_SC_INVALID_NS | NVME_SC_DNR;
 	}
 	mutex_lock(&subsys->lock);
-	if (req->ns->readonly == true)
-		result = NVME_NS_WRITE_PROTECT;
-	else
-		result = NVME_NS_NO_WRITE_PROTECT;
-	nvmet_set_result(req, result);
+	nvmet_set_result(req, req->ns->write_protect);
 	mutex_unlock(&subsys->lock);
 
 	return 0;
diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index 25d62d867563..036ce39cf838 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -681,6 +681,7 @@ struct nvmet_ns *nvmet_ns_alloc(struct nvmet_subsys *subsys, u32 nsid)
 
 	uuid_gen(&ns->uuid);
 	ns->buffered_io = false;
+	ns->write_protect = NVME_NS_NO_WRITE_PROTECT;
 
 	return ns;
 }
@@ -839,7 +840,7 @@ static inline u16 nvmet_check_ana_state(struct nvmet_port *port,
 
 static inline u16 nvmet_io_cmd_check_access(struct nvmet_req *req)
 {
-	if (unlikely(req->ns->readonly)) {
+	if (unlikely(req->ns->write_protect)) {
 		switch (req->cmd->common.opcode) {
 		case nvme_cmd_read:
 		case nvme_cmd_flush:
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index 559a15ccc322..7b9d64c097eb 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -57,7 +57,7 @@ struct nvmet_ns {
 	struct percpu_ref	ref;
 	struct block_device	*bdev;
 	struct file		*file;
-	bool			readonly;
+	enum nvme_ns_wp_state	write_protect;
 	u32			nsid;
 	u32			blksize_shift;
 	loff_t			size;
diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index d92535997687..ae54132cfab0 100644
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -1067,7 +1067,7 @@ enum {
 };
 
 /* NVMe Namespace Write Protect State */
-enum {
+enum nvme_ns_wp_state {
 	NVME_NS_NO_WRITE_PROTECT = 0,
 	NVME_NS_WRITE_PROTECT,
 	NVME_NS_WRITE_PROTECT_POWER_CYCLE,
-- 
2.22.1