From: Max Gurtovoy mgurtovoy@nvidia.com
[ 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@nvidia.com Signed-off-by: Christoph Hellwig hch@lst.de Signed-off-by: Sasha Levin sashal@kernel.org --- 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;