nvmet: expose firmware revision to configfs

Allow user to set currently active firmware revision

Reviewed-by: Konstantin Shelekhin <k.shelekhin@yadro.com>
Reviewed-by: Dmitriy Bogdanov <d.bogdanov@yadro.com>
Signed-off-by: Aleksandr Miloserdov <a.miloserdov@yadro.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

1 files changed, 63 insertions, 0 deletions

diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
index 02797170dd91..d48deb9bdb27 100644
--- a/drivers/nvme/target/configfs.c
+++ b/drivers/nvme/target/configfs.c
@@ -1307,6 +1307,68 @@ static ssize_t nvmet_subsys_attr_ieee_oui_store(struct config_item *item,
 }
 CONFIGFS_ATTR(nvmet_subsys_, attr_ieee_oui);
 
+static ssize_t nvmet_subsys_attr_firmware_show(struct config_item *item,
+					    char *page)
+{
+	struct nvmet_subsys *subsys = to_subsys(item);
+
+	return sysfs_emit(page, "%s\n", subsys->firmware_rev);
+}
+
+static ssize_t nvmet_subsys_attr_firmware_store_locked(struct nvmet_subsys *subsys,
+		const char *page, size_t count)
+{
+	int pos = 0, len;
+	char *val;
+
+	if (subsys->subsys_discovered) {
+		pr_err("Can't set firmware revision. %s is already assigned\n",
+		       subsys->firmware_rev);
+		return -EINVAL;
+	}
+
+	len = strcspn(page, "\n");
+	if (!len)
+		return -EINVAL;
+
+	if (len > NVMET_FR_MAX_SIZE) {
+		pr_err("Firmware revision size can not exceed %d Bytes\n",
+		       NVMET_FR_MAX_SIZE);
+		return -EINVAL;
+	}
+
+	for (pos = 0; pos < len; pos++) {
+		if (!nvmet_is_ascii(page[pos]))
+			return -EINVAL;
+	}
+
+	val = kmemdup_nul(page, len, GFP_KERNEL);
+	if (!val)
+		return -ENOMEM;
+
+	kfree(subsys->firmware_rev);
+
+	subsys->firmware_rev = val;
+
+	return count;
+}
+
+static ssize_t nvmet_subsys_attr_firmware_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);
+	ret = nvmet_subsys_attr_firmware_store_locked(subsys, page, count);
+	mutex_unlock(&subsys->lock);
+	up_write(&nvmet_config_sem);
+
+	return ret;
+}
+CONFIGFS_ATTR(nvmet_subsys_, attr_firmware);
+
 #ifdef CONFIG_BLK_DEV_INTEGRITY
 static ssize_t nvmet_subsys_attr_pi_enable_show(struct config_item *item,
 						char *page)
@@ -1369,6 +1431,7 @@ static struct configfs_attribute *nvmet_subsys_attrs[] = {
 	&nvmet_subsys_attr_attr_model,
 	&nvmet_subsys_attr_attr_qid_max,
 	&nvmet_subsys_attr_attr_ieee_oui,
+	&nvmet_subsys_attr_attr_firmware,
 #ifdef CONFIG_BLK_DEV_INTEGRITY
 	&nvmet_subsys_attr_attr_pi_enable,
 #endif