linux-stable/fs/btrfs/props.h
Filipe Manana d94df5eb5e btrfs: skip compression property for anything other than files and dirs
commit 4b73c55fde upstream.

The compression property only has effect on regular files and directories
(so that it's propagated to files and subdirectories created inside a
directory). For any other inode type (symlink, fifo, device, socket),
it's pointless to set the compression property because it does nothing
and ends up unnecessarily wasting leaf space due to the pointless xattr
(75 or 76 bytes, depending on the compression value). Symlinks in
particular are very common (for example, I have almost 10k symlinks under
/etc, /usr and /var alone) and therefore it's worth to avoid wasting
leaf space with the compression xattr.

For example, the compression property can end up on a symlink or character
device implicitly, through inheritance from a parent directory

  $ mkdir /mnt/testdir
  $ btrfs property set /mnt/testdir compression lzo

  $ ln -s yadayada /mnt/testdir/lnk
  $ mknod /mnt/testdir/dev c 0 0

Or explicitly like this:

  $ ln -s yadayda /mnt/lnk
  $ setfattr -h -n btrfs.compression -v lzo /mnt/lnk

So skip the compression property on inodes that are neither a regular
file nor a directory.

CC: stable@vger.kernel.org # 5.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-12 12:32:22 +02:00

30 lines
911 B
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2014 Filipe David Borba Manana <fdmanana@gmail.com>
*/
#ifndef BTRFS_PROPS_H
#define BTRFS_PROPS_H
#include "ctree.h"
void __init btrfs_props_init(void);
int btrfs_set_prop(struct btrfs_trans_handle *trans, struct inode *inode,
const char *name, const char *value, size_t value_len,
int flags);
int btrfs_validate_prop(const struct btrfs_inode *inode, const char *name,
const char *value, size_t value_len);
bool btrfs_ignore_prop(const struct btrfs_inode *inode, const char *name);
int btrfs_load_inode_props(struct inode *inode, struct btrfs_path *path);
int btrfs_inode_inherit_props(struct btrfs_trans_handle *trans,
struct inode *inode,
struct inode *dir);
int btrfs_subvol_inherit_props(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_root *parent_root);
#endif