1 files changed, 3 insertions, 0 deletions

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 8399d6d05d63..2e6039825b7b 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -519,6 +519,9 @@ static struct file_system_type btrfs_fs_type = {
         .fs_flags       = FS_REQUIRES_DEV,
 };
 
+/*
+ * used by btrfsctl to scan devices when no FS is mounted
+ */
 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
                                 unsigned long arg)
 {