From: Mark Ruijter <MRuijter@onestopsystems.com>
Date: Thu, 30 Jan 2020 10:29:32 -0800
Subject: [PATCH] nvmet: make ctrl model configurable
Git-commit: 013b7ebe5a0d70e2a02fd225174595e79c591b3e
Patch-mainline: v5.7-rc1
References: bsc#1169045
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>
Acked-by: Hannes Reinecke <hare@suse.com>
---
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 @@ static ssize_t nvmet_subsys_attr_cntlid_max_store(struct config_item *item,
}
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)
--
2.16.4