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