btrfs: make functions static when possible

Signed-off-by: David Sterba <dsterba@suse.cz>

fs/btrfs/ctree.c

@@ -74,7 +74,7 @@ noinline void btrfs_set_path_blocking(struct btrfs_path *p)
  * retake all the spinlocks in the path.  You can safely use NULL
  * for held
  */
-noinline void btrfs_clear_path_blocking(struct btrfs_path *p,
+static noinline void btrfs_clear_path_blocking(struct btrfs_path *p,
 					       struct extent_buffer *held)
 {
 	int i;

fs/btrfs/extent-tree.c

@@ -94,7 +94,7 @@ static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
 	return (cache->flags & bits) == bits;
 }
 
-void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
+static void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
 {
 	atomic_inc(&cache->count);
 }
@@ -3651,7 +3651,7 @@ static void block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv,
 	spin_unlock(&block_rsv->lock);
 }
 
-void block_rsv_release_bytes(struct btrfs_block_rsv *block_rsv,
+static void block_rsv_release_bytes(struct btrfs_block_rsv *block_rsv,
 				    struct btrfs_block_rsv *dest, u64 num_bytes)
 {
 	struct btrfs_space_info *space_info = block_rsv->space_info;

fs/btrfs/free-space-cache.c

@@ -1455,7 +1455,7 @@ static int insert_into_bitmap(struct btrfs_block_group_cache *block_group,
 	return ret;
 }
 
-bool try_merge_free_space(struct btrfs_block_group_cache *block_group,
+static bool try_merge_free_space(struct btrfs_block_group_cache *block_group,
 				 struct btrfs_free_space *info, bool update_stat)
 {
 	struct btrfs_free_space *left_info;