linux-hardened/fs/btrfs/Kconfig
Li Zefan a6fa6fae40 btrfs: Add lzo compression support
Lzo is a much faster compression algorithm than gzib, so would allow
more users to enable transparent compression, and some users can
choose from compression ratio and speed for different applications

Usage:

 # mount -t btrfs -o compress[=<zlib,lzo>] dev /mnt
or
 # mount -t btrfs -o compress-force[=<zlib,lzo>] dev /mnt

"-o compress" without argument is still allowed for compatability.

Compatibility:

If we mount a filesystem with lzo compression, it will not be able be
mounted in old kernels. One reason is, otherwise btrfs will directly
dump compressed data, which sits in inline extent, to user.

Performance:

The test copied a linux source tarball (~400M) from an ext4 partition
to the btrfs partition, and then extracted it.

(time in second)
           lzo        zlib        nocompress
copy:      10.6       21.7        14.9
extract:   70.1       94.4        66.6

(data size in MB)
           lzo        zlib        nocompress
copy:      185.87     108.69      394.49
extract:   193.80     132.36      381.21

Changelog:

v1 -> v2:
- Select LZO_COMPRESS and LZO_DECOMPRESS in btrfs Kconfig.
- Add incompability flag.
- Fix error handling in compress code.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2010-12-22 23:15:47 +08:00

33 lines
1 KiB
Text

config BTRFS_FS
tristate "Btrfs filesystem (EXPERIMENTAL) Unstable disk format"
depends on EXPERIMENTAL
select LIBCRC32C
select ZLIB_INFLATE
select ZLIB_DEFLATE
select LZO_COMPRESS
select LZO_DECOMPRESS
help
Btrfs is a new filesystem with extents, writable snapshotting,
support for multiple devices and many more features.
Btrfs is highly experimental, and THE DISK FORMAT IS NOT YET
FINALIZED. You should say N here unless you are interested in
testing Btrfs with non-critical data.
To compile this file system support as a module, choose M here. The
module will be called btrfs.
If unsure, say N.
config BTRFS_FS_POSIX_ACL
bool "Btrfs POSIX Access Control Lists"
depends on BTRFS_FS
select FS_POSIX_ACL
help
POSIX Access Control Lists (ACLs) support permissions for users and
groups beyond the owner/group/world scheme.
To learn more about Access Control Lists, visit the POSIX ACLs for
Linux website <http://acl.bestbits.at/>.
If you don't know what Access Control Lists are, say N