Re: [PATCH v2 2/2] fs: btrfs: use fs_ls_generic() and drop custom implementation

[Qu Wenruo <quwenruo.btrfs@gmx.com>]

在 2026/6/27 00:48, Alexey Charkov 写道:
> Now that generic callbacks for opendir/readdir/closedir are implemented,
> the custom btrfs_ls() implementation is no longer needed, along with the
> btrfs_iter_dir() callback iterator.
> 
> Use fs_ls_generic() instead.
> 
> Signed-off-by: Alexey Charkov <alchark@flipper.net>

Reviewed-by: Qu Wenruo <wqu@suse.com>

Thanks,
Qu

> ---
>   fs/btrfs/btrfs.c    | 129 ----------------------------------------------------
>   fs/btrfs/ctree.h    |   5 --
>   fs/btrfs/dir-item.c |  59 ++----------------------
>   fs/fs.c             |   2 +-
>   include/btrfs.h     |   1 -
>   5 files changed, 4 insertions(+), 192 deletions(-)
> 
> diff --git a/fs/btrfs/btrfs.c b/fs/btrfs/btrfs.c
> index 6f034861da90..e663dda12e80 100644
> --- a/fs/btrfs/btrfs.c
> +++ b/fs/btrfs/btrfs.c
> @@ -17,107 +17,6 @@
>   
>   struct btrfs_fs_info *current_fs_info;
>   
> -static int show_dir(struct btrfs_root *root, struct extent_buffer *eb,
> -		    struct btrfs_dir_item *di)
> -{
> -	struct btrfs_fs_info *fs_info = root->fs_info;
> -	struct btrfs_inode_item ii;
> -	struct btrfs_key key;
> -	static const char* dir_item_str[] = {
> -		[BTRFS_FT_REG_FILE]	= "   ",
> -		[BTRFS_FT_DIR]		= "DIR",
> -		[BTRFS_FT_CHRDEV]	= "CHR",
> -		[BTRFS_FT_BLKDEV]	= "BLK",
> -		[BTRFS_FT_FIFO]		= "FIF",
> -		[BTRFS_FT_SOCK]		= "SCK",
> -		[BTRFS_FT_SYMLINK]	= "SYM",
> -	};
> -	u8 type = btrfs_dir_type(eb, di);
> -	char namebuf[BTRFS_NAME_LEN];
> -	char *target = NULL;
> -	char filetime[32];
> -	time_t mtime;
> -	int ret = 0;
> -
> -	/* skip XATTRs in directory listing */
> -	if (type == BTRFS_FT_XATTR)
> -		return 0;
> -
> -	btrfs_dir_item_key_to_cpu(eb, di, &key);
> -
> -	if (key.type == BTRFS_ROOT_ITEM_KEY) {
> -		struct btrfs_root *subvol;
> -
> -		/* It's a subvolume, get its mtime from root item */
> -		subvol = btrfs_read_fs_root(fs_info, &key);
> -		if (IS_ERR(subvol)) {
> -			ret = PTR_ERR(subvol);
> -			error("Can't find root %llu", key.objectid);
> -			return ret;
> -		}
> -		mtime = btrfs_stack_timespec_sec(&subvol->root_item.otime);
> -	} else {
> -		struct btrfs_path path;
> -
> -		/* It's regular inode, get its mtime from inode item */
> -		btrfs_init_path(&path);
> -		ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
> -		if (ret > 0)
> -			ret = -ENOENT;
> -		if (ret < 0) {
> -			error("Can't find inode %llu", key.objectid);
> -			btrfs_release_path(&path);
> -			return ret;
> -		}
> -		read_extent_buffer(path.nodes[0], &ii,
> -			btrfs_item_ptr_offset(path.nodes[0], path.slots[0]),
> -			sizeof(ii));
> -		btrfs_release_path(&path);
> -		mtime = btrfs_stack_timespec_sec(&ii.mtime);
> -	}
> -	ctime_r(&mtime, filetime);
> -
> -	if (type == BTRFS_FT_SYMLINK) {
> -		target = malloc(fs_info->sectorsize);
> -		if (!target) {
> -			error("Can't alloc memory for symlink %llu",
> -				key.objectid);
> -			return -ENOMEM;
> -		}
> -		ret = btrfs_readlink(root, key.objectid, target);
> -		if (ret < 0) {
> -			error("Failed to read symlink %llu", key.objectid);
> -			goto out;
> -		}
> -		target[ret] = '\0';
> -	}
> -
> -	if (type < ARRAY_SIZE(dir_item_str) && dir_item_str[type])
> -		printf("<%s> ", dir_item_str[type]);
> -	else
> -		printf("?%3u? ", type);
> -	if (type == BTRFS_FT_CHRDEV || type == BTRFS_FT_BLKDEV) {
> -		ASSERT(key.type == BTRFS_INODE_ITEM_KEY);
> -		printf("%4llu,%5llu  ", btrfs_stack_inode_rdev(&ii) >> 20,
> -				btrfs_stack_inode_rdev(&ii) & 0xfffff);
> -	} else {
> -		if (key.type == BTRFS_INODE_ITEM_KEY)
> -			printf("%10llu  ", btrfs_stack_inode_size(&ii));
> -		else
> -			printf("%10llu  ", 0ULL);
> -	}
> -
> -	read_extent_buffer(eb, namebuf, (unsigned long)(di + 1),
> -			   btrfs_dir_name_len(eb, di));
> -	printf("%24.24s  %.*s", filetime, btrfs_dir_name_len(eb, di), namebuf);
> -	if (type == BTRFS_FT_SYMLINK)
> -		printf(" -> %s", target ? target : "?");
> -	printf("\n");
> -out:
> -	free(target);
> -	return ret;
> -}
> -
>   int btrfs_probe(struct blk_desc *fs_dev_desc,
>   		struct disk_partition *fs_partition)
>   {
> @@ -133,34 +32,6 @@ int btrfs_probe(struct blk_desc *fs_dev_desc,
>   	return ret;
>   }
>   
> -int btrfs_ls(const char *path)
> -{
> -	struct btrfs_fs_info *fs_info = current_fs_info;
> -	struct btrfs_root *root = fs_info->fs_root;
> -	u64 ino = BTRFS_FIRST_FREE_OBJECTID;
> -	u8 type;
> -	int ret;
> -
> -	ASSERT(fs_info);
> -	ret = btrfs_lookup_path(fs_info->fs_root, BTRFS_FIRST_FREE_OBJECTID,
> -				path, &root, &ino, &type, 40);
> -	if (ret < 0) {
> -		printf("Cannot lookup path %s\n", path);
> -		return ret;
> -	}
> -
> -	if (type != BTRFS_FT_DIR) {
> -		error("Not a directory: %s", path);
> -		return -ENOENT;
> -	}
> -	ret = btrfs_iter_dir(root, ino, show_dir);
> -	if (ret < 0) {
> -		error("An error occurred while listing directory %s", path);
> -		return ret;
> -	}
> -	return 0;
> -}
> -
>   /*
>    * The fs layer closes and re-probes btrfs between readdir() calls (see
>    * fs_readdir() in fs/fs.c), freeing and reallocating fs_info, so root cannot
> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
> index 7de35aa7efd5..3fa9a8c9c020 100644
> --- a/fs/btrfs/ctree.h
> +++ b/fs/btrfs/ctree.h
> @@ -1220,11 +1220,6 @@ struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
>   					     struct btrfs_path *path, u64 dir,
>   					     const char *name, int name_len,
>   					     int mod);
> -typedef int (*btrfs_iter_dir_callback_t)(struct btrfs_root *root,
> -					 struct extent_buffer *eb,
> -					 struct btrfs_dir_item *di);
> -int btrfs_iter_dir(struct btrfs_root *root, u64 ino,
> -		   btrfs_iter_dir_callback_t callback);
>   int btrfs_next_dir_entry(struct btrfs_root *root, u64 ino, u64 *offset,
>   			 char *namebuf, int namebuf_len, u8 *ftype);
>   /* inode.c */
> diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
> index b12298e20c41..c7b87d60d986 100644
> --- a/fs/btrfs/dir-item.c
> +++ b/fs/btrfs/dir-item.c
> @@ -114,65 +114,12 @@ struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
>   	return btrfs_match_dir_item_name(root, path, name, name_len);
>   }
>   
> -int btrfs_iter_dir(struct btrfs_root *root, u64 ino,
> -		   btrfs_iter_dir_callback_t callback)
> -{
> -	struct btrfs_path path;
> -	struct btrfs_key key;
> -	int ret;
> -
> -	btrfs_init_path(&path);
> -	key.objectid = ino;
> -	key.type = BTRFS_DIR_INDEX_KEY;
> -	key.offset = 0;
> -
> -	ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
> -	if (ret < 0)
> -		return ret;
> -	/* Should not happen */
> -	if (ret == 0) {
> -		ret = -EUCLEAN;
> -		goto out;
> -	}
> -	if (path.slots[0] >= btrfs_header_nritems(path.nodes[0])) {
> -		ret = btrfs_next_leaf(root, &path);
> -		if (ret < 0)
> -			goto out;
> -		if (ret > 0) {
> -			ret = 0;
> -			goto out;
> -		}
> -	}
> -	do {
> -		struct btrfs_dir_item *di;
> -
> -		btrfs_item_key_to_cpu(path.nodes[0], &key, path.slots[0]);
> -		if (key.objectid != ino || key.type != BTRFS_DIR_INDEX_KEY)
> -			break;
> -		di = btrfs_item_ptr(path.nodes[0], path.slots[0],
> -				    struct btrfs_dir_item);
> -		if (verify_dir_item(root, path.nodes[0], di)) {
> -			ret = -EUCLEAN;
> -			goto out;
> -		}
> -		ret = callback(root, path.nodes[0], di);
> -		if (ret < 0)
> -			goto out;
> -	} while (!(ret = btrfs_next_item(root, &path)));
> -
> -	if (ret > 0)
> -		ret = 0;
> -out:
> -	btrfs_release_path(&path);
> -	return ret;
> -}
> -
>   /*
>    * btrfs_next_dir_entry() - read one directory entry at or after a cursor
>    *
> - * Streaming counterpart to btrfs_iter_dir() for the fs-layer readdir, which
> - * is re-entered once per entry: returns the first real entry whose
> - * BTRFS_DIR_INDEX_KEY offset is >= *offset and advances *offset past it.
> + * Iterator for the fs-layer readdir, which is re-entered once per entry:
> + * returns the first real entry whose BTRFS_DIR_INDEX_KEY offset is
> + * >= *offset and advances *offset past it.
>    *
>    * @root, @ino:		directory to read
>    * @offset:		in/out cursor; DIR_INDEX offset to resume from
> diff --git a/fs/fs.c b/fs/fs.c
> index 4694a88f776b..1ebda6f4ee2a 100644
> --- a/fs/fs.c
> +++ b/fs/fs.c
> @@ -320,7 +320,7 @@ static struct fstype_info fstypes[] = {
>   		.null_dev_desc_ok = false,
>   		.probe = btrfs_probe,
>   		.close = btrfs_close,
> -		.ls = btrfs_ls,
> +		.ls = fs_ls_generic,
>   		.exists = btrfs_exists,
>   		.size = btrfs_size,
>   		.read = btrfs_read,
> diff --git a/include/btrfs.h b/include/btrfs.h
> index 6fff45a497ee..3878b7817ea6 100644
> --- a/include/btrfs.h
> +++ b/include/btrfs.h
> @@ -15,7 +15,6 @@ struct fs_dirent;
>   
>   int btrfs_probe(struct blk_desc *fs_dev_desc,
>   		struct disk_partition *fs_partition);
> -int btrfs_ls(const char *);
>   int btrfs_exists(const char *);
>   int btrfs_size(const char *, loff_t *);
>   int btrfs_read(const char *, void *, loff_t, loff_t, loff_t *);
>