diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 8888337a95b6455c31b091025cc0e940dc69a954..ddbad8d5094906af82109ad196dcc43203dd3422 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1919,7 +1919,7 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data)
 }
 
 /* Used to sort the devices by max_avail(descending sort) */
-static int btrfs_cmp_device_free_bytes(const void *dev_info1,
+static inline int btrfs_cmp_device_free_bytes(const void *dev_info1,
 				       const void *dev_info2)
 {
 	if (((struct btrfs_device_info *)dev_info1)->max_avail >
@@ -1948,8 +1948,8 @@ static inline void btrfs_descending_sort_devices(
  * The helper to calc the free space on the devices that can be used to store
  * file data.
  */
-static int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info,
-				       u64 *free_bytes)
+static inline int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info,
+					      u64 *free_bytes)
 {
 	struct btrfs_device_info *devices_info;
 	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;