diff options
author | Max Gurtovoy <mgurtovoy@nvidia.com> | 2021-02-17 17:19:40 +0000 |
---|---|---|
committer | Christoph Hellwig <hch@lst.de> | 2021-03-05 13:41:03 +0100 |
commit | d9f273b7585c380d7a10d4b3187ddc2d37f2740b (patch) | |
tree | 998d7f00c98c8e32455368f243f5ccef5ab577bf /drivers/nvme/target/configfs.c | |
parent | 32feb6de47242e54692eceab52cfae8616aa0518 (diff) |
nvmet: model_number must be immutable once set
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>
Diffstat (limited to 'drivers/nvme/target/configfs.c')
-rw-r--r-- | drivers/nvme/target/configfs.c | 50 |
1 files changed, 23 insertions, 27 deletions
diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c index 635a7cb45d0b..e5dbd1923b7b 100644 --- a/drivers/nvme/target/configfs.c +++ b/drivers/nvme/target/configfs.c @@ -1118,16 +1118,12 @@ 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; } @@ -1138,14 +1134,17 @@ 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; @@ -1155,28 +1154,25 @@ 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); |