btrfs: use LIST_HEAD() to initialize the list_head

Use LIST_HEAD() to initialize the list_head instead of open-coding it.
Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/disk-io.c

@@ -4554,9 +4554,7 @@ static void btrfs_destroy_ordered_extents(struct btrfs_root *root)
 static void btrfs_destroy_all_ordered_extents(struct btrfs_fs_info *fs_info)
 {
 	struct btrfs_root *root;
-	struct list_head splice;
-
-	INIT_LIST_HEAD(&splice);
+	LIST_HEAD(splice);
 
 	spin_lock(&fs_info->ordered_root_lock);
 	list_splice_init(&fs_info->ordered_roots, &splice);
@@ -4662,9 +4660,7 @@ static void btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
 {
 	struct btrfs_inode *btrfs_inode;
-	struct list_head splice;
-
-	INIT_LIST_HEAD(&splice);
+	LIST_HEAD(splice);
 
 	spin_lock(&root->delalloc_lock);
 	list_splice_init(&root->delalloc_inodes, &splice);
@@ -4697,9 +4693,7 @@ static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
 static void btrfs_destroy_all_delalloc_inodes(struct btrfs_fs_info *fs_info)
 {
 	struct btrfs_root *root;
-	struct list_head splice;
-
-	INIT_LIST_HEAD(&splice);
+	LIST_HEAD(splice);
 
 	spin_lock(&fs_info->delalloc_root_lock);
 	list_splice_init(&fs_info->delalloc_roots, &splice);

fs/btrfs/file.c

@@ -3018,7 +3018,7 @@ static long btrfs_fallocate(struct file *file, int mode,
 	struct extent_changeset *data_reserved = NULL;
 	struct falloc_range *range;
 	struct falloc_range *tmp;
-	struct list_head reserve_list;
+	LIST_HEAD(reserve_list);
 	u64 cur_offset;
 	u64 last_byte;
 	u64 alloc_start;
@@ -3110,7 +3110,6 @@ static long btrfs_fallocate(struct file *file, int mode,
 	btrfs_assert_inode_range_clean(BTRFS_I(inode), alloc_start, locked_end);
 
 	/* First, check if we exceed the qgroup limit */
-	INIT_LIST_HEAD(&reserve_list);
 	while (cur_offset < alloc_end) {
 		em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur_offset,
 				      alloc_end - cur_offset);

fs/btrfs/inode.c

@@ -5861,8 +5861,8 @@ static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
 	struct btrfs_key found_key;
 	struct btrfs_path *path;
 	void *addr;
-	struct list_head ins_list;
-	struct list_head del_list;
+	LIST_HEAD(ins_list);
+	LIST_HEAD(del_list);
 	int ret;
 	char *name_ptr;
 	int name_len;
@@ -5881,8 +5881,6 @@ static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
 	addr = private->filldir_buf;
 	path->reada = READA_FORWARD;
 
-	INIT_LIST_HEAD(&ins_list);
-	INIT_LIST_HEAD(&del_list);
 	put = btrfs_readdir_get_delayed_items(inode, private->last_index,
 					      &ins_list, &del_list);
 
@@ -9244,14 +9242,11 @@ static int start_delalloc_inodes(struct btrfs_root *root,
 	struct btrfs_inode *binode;
 	struct inode *inode;
 	struct btrfs_delalloc_work *work, *next;
-	struct list_head works;
-	struct list_head splice;
+	LIST_HEAD(works);
+	LIST_HEAD(splice);
 	int ret = 0;
 	bool full_flush = wbc->nr_to_write == LONG_MAX;
 
-	INIT_LIST_HEAD(&works);
-	INIT_LIST_HEAD(&splice);
-
 	mutex_lock(&root->delalloc_mutex);
 	spin_lock(&root->delalloc_lock);
 	list_splice_init(&root->delalloc_inodes, &splice);
@@ -9339,14 +9334,12 @@ int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, long nr,
 		.range_end = LLONG_MAX,
 	};
 	struct btrfs_root *root;
-	struct list_head splice;
+	LIST_HEAD(splice);
 	int ret;
 
 	if (BTRFS_FS_ERROR(fs_info))
 		return -EROFS;
 
-	INIT_LIST_HEAD(&splice);
-
 	mutex_lock(&fs_info->delalloc_root_mutex);
 	spin_lock(&fs_info->delalloc_root_lock);
 	list_splice_init(&fs_info->delalloc_roots, &splice);

fs/btrfs/ordered-data.c

@@ -740,11 +740,9 @@ void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
 			     const u64 range_start, const u64 range_len)
 {
 	struct btrfs_root *root;
-	struct list_head splice;
+	LIST_HEAD(splice);
 	u64 done;
 
-	INIT_LIST_HEAD(&splice);
-
 	mutex_lock(&fs_info->ordered_operations_mutex);
 	spin_lock(&fs_info->ordered_root_lock);
 	list_splice_init(&fs_info->ordered_roots, &splice);

fs/btrfs/send.c

@@ -3685,7 +3685,7 @@ static void tail_append_pending_moves(struct send_ctx *sctx,
 static int apply_children_dir_moves(struct send_ctx *sctx)
 {
 	struct pending_dir_move *pm;
-	struct list_head stack;
+	LIST_HEAD(stack);
 	u64 parent_ino = sctx->cur_ino;
 	int ret = 0;
 
@@ -3693,7 +3693,6 @@ static int apply_children_dir_moves(struct send_ctx *sctx)
 	if (!pm)
 		return 0;
 
-	INIT_LIST_HEAD(&stack);
 	tail_append_pending_moves(sctx, pm, &stack);
 
 	while (!list_empty(&stack)) {
@@ -4165,7 +4164,7 @@ static int process_recorded_refs(struct send_ctx *sctx, int *pending_move)
 	int ret = 0;
 	struct recorded_ref *cur;
 	struct recorded_ref *cur2;
-	struct list_head check_dirs;
+	LIST_HEAD(check_dirs);
 	struct fs_path *valid_path = NULL;
 	u64 ow_inode = 0;
 	u64 ow_gen;
@@ -4184,7 +4183,6 @@ static int process_recorded_refs(struct send_ctx *sctx, int *pending_move)
 	 * which is always '..'
 	 */
 	BUG_ON(sctx->cur_ino <= BTRFS_FIRST_FREE_OBJECTID);
-	INIT_LIST_HEAD(&check_dirs);
 
 	valid_path = fs_path_alloc();
 	if (!valid_path) {

fs/btrfs/tree-log.c

@@ -4841,13 +4841,11 @@ static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans,
 	struct btrfs_ordered_extent *ordered;
 	struct btrfs_ordered_extent *tmp;
 	struct extent_map *em, *n;
-	struct list_head extents;
+	LIST_HEAD(extents);
 	struct extent_map_tree *tree = &inode->extent_tree;
 	int ret = 0;
 	int num = 0;
 
-	INIT_LIST_HEAD(&extents);
-
 	write_lock(&tree->lock);
 
 	list_for_each_entry_safe(em, n, &tree->modified_extents, list) {