From 013b7ebe5a0d70e2a02fd225174595e79c591b3e Mon Sep 17 00:00:00 2001 From: Mark Ruijter Date: Thu, 30 Jan 2020 10:29:32 -0800 Subject: [PATCH] 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 Reviewed-by: Sagi Grimberg Signed-off-by: Mark Ruijter [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 Signed-off-by: Keith Busch --- drivers/nvme/target/admin-cmd.c | 17 +++++++++-- drivers/nvme/target/configfs.c | 66 +++++++++++++++++++++++++++++++++++++++++ drivers/nvme/target/core.c | 1 + drivers/nvme/target/nvmet.h | 8 +++++ 4 files changed, 90 insertions(+), 2 deletions(-) diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c index 72a7e41f3018..19f949570625 100644 --- a/drivers/nvme/target/admin-cmd.c +++ b/drivers/nvme/target/admin-cmd.c @@ -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), ' '); diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c index 71c50751b5a6..1654064deea5 100644 --- a/drivers/nvme/target/configfs.c +++ b/drivers/nvme/target/configfs.c @@ -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, }; diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c index 48080c948692..b685f99d56a1 100644 --- a/drivers/nvme/target/core.c +++ b/drivers/nvme/target/core.c @@ -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); } diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h index c2d518fb1789..42ba2ddd9e96 100644 --- a/drivers/nvme/target/nvmet.h +++ b/drivers/nvme/target/nvmet.h @@ -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) -- 2.11.0