From a6fa6fae40ec336c7df6155255ae64ebef43a8bc Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Mon, 25 Oct 2010 15:12:26 +0800 Subject: 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[=] dev /mnt or # mount -t btrfs -o compress-force[=] 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 --- fs/btrfs/ctree.h | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'fs/btrfs/ctree.h') diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index e065344..53b9846 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -398,13 +398,15 @@ struct btrfs_super_block { #define BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF (1ULL << 0) #define BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL (1ULL << 1) #define BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS (1ULL << 2) +#define BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO (1ULL << 3) #define BTRFS_FEATURE_COMPAT_SUPP 0ULL #define BTRFS_FEATURE_COMPAT_RO_SUPP 0ULL #define BTRFS_FEATURE_INCOMPAT_SUPP \ (BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF | \ BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL | \ - BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) + BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS | \ + BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO) /* * A leaf is full of items. offset and size tell us where to find @@ -553,8 +555,9 @@ struct btrfs_timespec { enum btrfs_compression_type { BTRFS_COMPRESS_NONE = 0, BTRFS_COMPRESS_ZLIB = 1, - BTRFS_COMPRESS_TYPES = 1, - BTRFS_COMPRESS_LAST = 2, + BTRFS_COMPRESS_LZO = 2, + BTRFS_COMPRESS_TYPES = 2, + BTRFS_COMPRESS_LAST = 3, }; struct btrfs_inode_item { -- cgit v1.1