nvmet: make ctrl model configurable

This patch adds a new target subsys attribute which allows user to
optionally specify model name which then used in the
nvmet_execute_identify_ctrl() to fill up the nvme_id_ctrl structure.

The default value for the model is set to "Linux" for backward
compatibility.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Mark Ruijter <MRuijter@onestopsystems.com>
[chaitanya.kulkarni@wdc.com
 *Use macro for default model, coding style fixes.
 *Use RCU for accessing model in for configfs and in
  nvmet_execute_identify_ctrl().
]
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
This commit is contained in:
Mark Ruijter 2020-01-30 10:29:32 -08:00 committed by Keith Busch
parent 94a39d61f8
commit 013b7ebe5a
4 changed files with 90 additions and 2 deletions

View File

@ -322,12 +322,25 @@ 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)
{
const char *model = NVMET_DEFAULT_CTRL_MODEL;
struct nvmet_subsys_model *subsys_model;
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();
}
static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
{
struct nvmet_ctrl *ctrl = req->sq->ctrl;
struct nvme_id_ctrl *id;
u16 status = 0;
const char model[] = "Linux";
id = kzalloc(sizeof(*id), GFP_KERNEL);
if (!id) {
@ -342,7 +355,7 @@ 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));
memcpy_and_pad(id->mn, sizeof(id->mn), model, sizeof(model) - 1, ' ');
nvmet_id_set_model_number(id, ctrl->subsys);
memcpy_and_pad(id->fr, sizeof(id->fr),
UTS_RELEASE, strlen(UTS_RELEASE), ' ');

View File

@ -919,12 +919,78 @@ out_unlock:
}
CONFIGFS_ATTR(nvmet_subsys_, attr_cntlid_max);
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();
return ret;
}
/* See Section 1.5 of NVMe 1.4 */
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)
{
struct nvmet_subsys *subsys = to_subsys(item);
struct nvmet_subsys_model *new_model;
char *new_model_number;
int pos = 0, len;
len = strcspn(page, "\n");
if (!len)
return -EINVAL;
for (pos = 0; pos < len; pos++) {
if (!nvmet_is_ascii(page[pos]))
return -EINVAL;
}
new_model_number = kstrndup(page, len, GFP_KERNEL);
if (!new_model_number)
return -ENOMEM;
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);
down_write(&nvmet_config_sem);
mutex_lock(&subsys->lock);
new_model = rcu_replace_pointer(subsys->model, new_model,
mutex_is_locked(&subsys->lock));
mutex_unlock(&subsys->lock);
up_write(&nvmet_config_sem);
kfree_rcu(new_model, rcuhead);
return count;
}
CONFIGFS_ATTR(nvmet_subsys_, attr_model);
static struct configfs_attribute *nvmet_subsys_attrs[] = {
&nvmet_subsys_attr_attr_allow_any_host,
&nvmet_subsys_attr_attr_version,
&nvmet_subsys_attr_attr_serial,
&nvmet_subsys_attr_attr_cntlid_min,
&nvmet_subsys_attr_attr_cntlid_max,
&nvmet_subsys_attr_attr_model,
NULL,
};

View File

@ -1461,6 +1461,7 @@ static void nvmet_subsys_free(struct kref *ref)
WARN_ON_ONCE(!list_empty(&subsys->namespaces));
kfree(subsys->subsysnqn);
kfree_rcu(subsys->model, rcuhead);
kfree(subsys);
}

View File

@ -23,6 +23,7 @@
#define NVMET_ASYNC_EVENTS 4
#define NVMET_ERROR_LOG_SLOTS 128
#define NVMET_NO_ERROR_LOC ((u16)-1)
#define NVMET_DEFAULT_CTRL_MODEL "Linux"
/*
* Supported optional AENs:
@ -202,6 +203,11 @@ struct nvmet_ctrl {
struct nvme_error_slot slots[NVMET_ERROR_LOG_SLOTS];
};
struct nvmet_subsys_model {
struct rcu_head rcuhead;
char number[];
};
struct nvmet_subsys {
enum nvme_subsys_type type;
@ -229,6 +235,8 @@ struct nvmet_subsys {
struct config_group namespaces_group;
struct config_group allowed_hosts_group;
struct nvmet_subsys_model __rcu *model;
};
static inline struct nvmet_subsys *to_subsys(struct config_item *item)