1 files changed, 28 insertions, 19 deletions

diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
index 4c86697fe4ec..bbcbbfa72b07 100644
--- a/drivers/target/target_core_configfs.c
+++ b/drivers/target/target_core_configfs.c
@@ -72,6 +72,9 @@ static struct config_group target_core_hbagroup;
 static struct config_group alua_group;
 static struct config_group alua_lu_gps_group;
 
+static unsigned int target_devices;
+static DEFINE_MUTEX(target_devices_lock);
+
 static inline struct se_hba *
 item_to_hba(struct config_item *item)
 {
@@ -105,51 +108,48 @@ static ssize_t target_core_item_dbroot_store(struct config_item *item,
 {
 	ssize_t read_bytes;
 	struct file *fp;
+	ssize_t r = -EINVAL;
 
-	mutex_lock(&g_tf_lock);
-	if (!list_empty(&g_tf_list)) {
-		mutex_unlock(&g_tf_lock);
-		pr_err("db_root: cannot be changed: target drivers registered");
-		return -EINVAL;
+	mutex_lock(&target_devices_lock);
+	if (target_devices) {
+		pr_err("db_root: cannot be changed because it's in use\n");
+		goto unlock;
 	}
 
 	if (count > (DB_ROOT_LEN - 1)) {
-		mutex_unlock(&g_tf_lock);
 		pr_err("db_root: count %d exceeds DB_ROOT_LEN-1: %u\n",
 		       (int)count, DB_ROOT_LEN - 1);
-		return -EINVAL;
+		goto unlock;
 	}
 
 	read_bytes = snprintf(db_root_stage, DB_ROOT_LEN, "%s", page);
-	if (!read_bytes) {
-		mutex_unlock(&g_tf_lock);
-		return -EINVAL;
-	}
+	if (!read_bytes)
+		goto unlock;
+
 	if (db_root_stage[read_bytes - 1] == '\n')
 		db_root_stage[read_bytes - 1] = '\0';
 
 	/* validate new db root before accepting it */
 	fp = filp_open(db_root_stage, O_RDONLY, 0);
 	if (IS_ERR(fp)) {
-		mutex_unlock(&g_tf_lock);
 		pr_err("db_root: cannot open: %s\n", db_root_stage);
-		return -EINVAL;
+		goto unlock;
 	}
 	if (!S_ISDIR(file_inode(fp)->i_mode)) {
 		filp_close(fp, NULL);
-		mutex_unlock(&g_tf_lock);
 		pr_err("db_root: not a directory: %s\n", db_root_stage);
-		return -EINVAL;
+		goto unlock;
 	}
 	filp_close(fp, NULL);
 
 	strncpy(db_root, db_root_stage, read_bytes);
-
-	mutex_unlock(&g_tf_lock);
-
 	pr_debug("Target_Core_ConfigFS: db_root set to %s\n", db_root);
 
-	return read_bytes;
+	r = read_bytes;
+
+unlock:
+	mutex_unlock(&target_devices_lock);
+	return r;
 }
 
 CONFIGFS_ATTR(target_core_item_, dbroot);
@@ -3316,6 +3316,10 @@ static struct config_group *target_core_make_subdev(
 	 */
 	target_stat_setup_dev_default_groups(dev);
 
+	mutex_lock(&target_devices_lock);
+	target_devices++;
+	mutex_unlock(&target_devices_lock);
+
 	mutex_unlock(&hba->hba_access_mutex);
 	return &dev->dev_group;
 
@@ -3354,6 +3358,11 @@ static void target_core_drop_subdev(
 	 * se_dev is released from target_core_dev_item_ops->release()
 	 */
 	config_item_put(item);
+
+	mutex_lock(&target_devices_lock);
+	target_devices--;
+	mutex_unlock(&target_devices_lock);
+
 	mutex_unlock(&hba->hba_access_mutex);
 }