From: Max Gurtovoy <mgurtovoy@xxxxxxxxxx>
[ Upstream commit d9f273b7585c380d7a10d4b3187ddc2d37f2740b ]
In case we have already established connection to nvmf target, it
shouldn't be allowed to change the model_number. E.g. if someone will
identify ctrl and get model_number of "my_model" later on will change
the model_numbel via configfs to "my_new_model" this will break the NVMe
specification for "Get Log Page – Persistent Event Log" that refers to
Model Number as: "This field contains the same value as reported in the
Model Number field of the Identify Controller data structure, bytes
63:24."
Although it doesn't mentioned explicitly that this field can't be
changed, we can assume it.
So allow setting this field only once: using configfs or in the first
identify ctrl operation.
Signed-off-by: Max Gurtovoy <mgurtovoy@xxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/nvme/target/admin-cmd.c | 36 ++++++++++++++++--------
drivers/nvme/target/configfs.c | 50 +++++++++++++++------------------
drivers/nvme/target/core.c | 2 +-
drivers/nvme/target/nvmet.h | 7 +----
4 files changed, 50 insertions(+), 45 deletions(-)
diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index 1827d8d8f3b0..44d6d9f419d0 100644
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -319,27 +319,40 @@ static void nvmet_execute_get_log_page(struct nvmet_req *req)
nvmet_req_complete(req, NVME_SC_INVALID_FIELD | NVME_SC_DNR);
}
-static void nvmet_id_set_model_number(struct nvme_id_ctrl *id,
- struct nvmet_subsys *subsys)
+static u16 nvmet_set_model_number(struct nvmet_subsys *subsys)
{
- const char *model = NVMET_DEFAULT_CTRL_MODEL;
- struct nvmet_subsys_model *subsys_model;
+ u16 status = 0;
+
+ mutex_lock(&subsys->lock);
+ if (!subsys->model_number) {
+ subsys->model_number =
+ kstrdup(NVMET_DEFAULT_CTRL_MODEL, GFP_KERNEL);
+ if (!subsys->model_number)
+ status = NVME_SC_INTERNAL;
+ }
+ mutex_unlock(&subsys->lock);
- rcu_read_lock();
- subsys_model = rcu_dereference(subsys->model);
- if (subsys_model)
- model = subsys_model->number;
- memcpy_and_pad(id->mn, sizeof(id->mn), model, strlen(model), ' ');
- rcu_read_unlock();
+ return status;
}
static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
{
struct nvmet_ctrl *ctrl = req->sq->ctrl;
+ struct nvmet_subsys *subsys = ctrl->subsys;
struct nvme_id_ctrl *id;
u32 cmd_capsule_size;
u16 status = 0;
+ /*
+ * If there is no model number yet, set it now. It will then remain
+ * stable for the life time of the subsystem.
+ */
+ if (!subsys->model_number) {
+ status = nvmet_set_model_number(subsys);
+ if (status)
+ goto out;
+ }
+
id = kzalloc(sizeof(*id), GFP_KERNEL);
if (!id) {
status = NVME_SC_INTERNAL;
@@ -353,7 +366,8 @@ static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
memset(id->sn, ' ', sizeof(id->sn));
bin2hex(id->sn, &ctrl->subsys->serial,
min(sizeof(ctrl->subsys->serial), sizeof(id->sn) / 2));
- nvmet_id_set_model_number(id, ctrl->subsys);
+ memcpy_and_pad(id->mn, sizeof(id->mn), subsys->model_number,
+ strlen(subsys->model_number), ' ');
memcpy_and_pad(id->fr, sizeof(id->fr),
UTS_RELEASE, strlen(UTS_RELEASE), ' ');
diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
index c61ffd767062..4b809fe499c2 100644
--- a/drivers/nvme/target/configfs.c
+++ b/drivers/nvme/target/configfs.c
@@ -1120,16 +1120,12 @@ static ssize_t nvmet_subsys_attr_model_show(struct config_item *item,
char *page)
{
struct nvmet_subsys *subsys = to_subsys(item);
- struct nvmet_subsys_model *subsys_model;
- char *model = NVMET_DEFAULT_CTRL_MODEL;
int ret;
- rcu_read_lock();
- subsys_model = rcu_dereference(subsys->model);
- if (subsys_model)
- model = subsys_model->number;
- ret = snprintf(page, PAGE_SIZE, "%s\n", model);
- rcu_read_unlock();
+ mutex_lock(&subsys->lock);
+ ret = snprintf(page, PAGE_SIZE, "%s\n", subsys->model_number ?
+ subsys->model_number : NVMET_DEFAULT_CTRL_MODEL);
+ mutex_unlock(&subsys->lock);
return ret;
}
@@ -1140,14 +1136,17 @@ static bool nvmet_is_ascii(const char c)
return c >= 0x20 && c <= 0x7e;
}
-static ssize_t nvmet_subsys_attr_model_store(struct config_item *item,
- const char *page, size_t count)
+static ssize_t nvmet_subsys_attr_model_store_locked(struct nvmet_subsys *subsys,
+ const char *page, size_t count)
{
- struct nvmet_subsys *subsys = to_subsys(item);
- struct nvmet_subsys_model *new_model;
- char *new_model_number;
int pos = 0, len;
+ if (subsys->model_number) {
+ pr_err("Can't set model number. %s is already assigned\n",
+ subsys->model_number);
+ return -EINVAL;
+ }
+
len = strcspn(page, "\n");
if (!len)
return -EINVAL;
@@ -1157,28 +1156,25 @@ static ssize_t nvmet_subsys_attr_model_store(struct config_item *item,
return -EINVAL;
}
- new_model_number = kmemdup_nul(page, len, GFP_KERNEL);
- if (!new_model_number)
+ subsys->model_number = kmemdup_nul(page, len, GFP_KERNEL);
+ if (!subsys->model_number)
return -ENOMEM;
+ return count;
+}
- new_model = kzalloc(sizeof(*new_model) + len + 1, GFP_KERNEL);
- if (!new_model) {
- kfree(new_model_number);
- return -ENOMEM;
- }
- memcpy(new_model->number, new_model_number, len);
+static ssize_t nvmet_subsys_attr_model_store(struct config_item *item,
+ const char *page, size_t count)
+{
+ struct nvmet_subsys *subsys = to_subsys(item);
+ ssize_t ret;
down_write(&nvmet_config_sem);
mutex_lock(&subsys->lock);
- new_model = rcu_replace_pointer(subsys->model, new_model,
- mutex_is_locked(&subsys->lock));
+ ret = nvmet_subsys_attr_model_store_locked(subsys, page, count);
mutex_unlock(&subsys->lock);
up_write(&nvmet_config_sem);
- kfree_rcu(new_model, rcuhead);
- kfree(new_model_number);
-
- return count;
+ return ret;
}
CONFIGFS_ATTR(nvmet_subsys_, attr_model);
diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index 8ce4d59cc9e7..c7af907912f2 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -1521,7 +1521,7 @@ static void nvmet_subsys_free(struct kref *ref)
nvmet_passthru_subsys_free(subsys);
kfree(subsys->subsysnqn);
- kfree_rcu(subsys->model, rcuhead);
+ kfree(subsys->model_number);
kfree(subsys);
}
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index 592763732065..aac741bf378c 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -208,11 +208,6 @@ struct nvmet_ctrl {
bool pi_support;
};
-struct nvmet_subsys_model {
- struct rcu_head rcuhead;
- char number[];
-};
-
struct nvmet_subsys {
enum nvme_subsys_type type;
@@ -242,7 +237,7 @@ struct nvmet_subsys {
struct config_group namespaces_group;
struct config_group allowed_hosts_group;
- struct nvmet_subsys_model __rcu *model;
+ char *model_number;
#ifdef CONFIG_NVME_TARGET_PASSTHRU
struct nvme_ctrl *passthru_ctrl;
--
2.30.1
