Data deduplication is a specialized data compression technique for eliminating duplicate copies of repeating data.[1]
This patch set is also related to "Content based storage" in project ideas[2]. PATCH 1 is a hang fix with deduplication on, but it's also useful without dedup in practice use. PATCH 2 and 3 are targetting delayed refs' scalability problems, which are uncovered by the dedup feature. PATCH 4 is a speed-up improvement, which is about dedup and quota. PATCH 5 is full of real things, all details about implementation of dedup. Plus, there is also a btrfs-progs patch which helps to enable/disable dedup feature. TODO: * a bit-to-bit comparison callback. All comments are welcome! [1]: http://en.wikipedia.org/wiki/Data_deduplication [2]: https://btrfs.wiki.kernel.org/index.php/Project_ideas#Content_based_storage v5->v6: - remove BUG_ON()s and use proper error handling. - make dedup hash endian safe on disk. - refractor dedup tree item. - fix a bug of deleting file extents with dedup disabled. - some cleanups - add manpage for dedup subcommand. v4->v5: - go back to one dedup key with a special backref for dedup tree because the disk format understands backref well. - fix a fsync hang with dedup enabled. - rebase onto the latest btrfs. Liu Bo (5): Btrfs: skip merge part for delayed data refs Btrfs: improve the delayed refs process in rm case Btrfs: introduce a head ref rbtree Btrfs: disable qgroups accounting when quata_enable is 0 Btrfs: online data deduplication fs/btrfs/backref.c | 9 + fs/btrfs/ctree.c | 2 +- fs/btrfs/ctree.h | 82 ++++++ fs/btrfs/delayed-ref.c | 159 +++++++---- fs/btrfs/delayed-ref.h | 8 + fs/btrfs/disk-io.c | 31 ++ fs/btrfs/extent-tree.c | 190 +++++++++++-- fs/btrfs/extent_io.c | 29 ++- fs/btrfs/extent_io.h | 16 + fs/btrfs/file-item.c | 211 ++++++++++++++ fs/btrfs/inode.c | 673 +++++++++++++++++++++++++++++++++++++++----- fs/btrfs/ioctl.c | 93 ++++++ fs/btrfs/ordered-data.c | 38 ++- fs/btrfs/ordered-data.h | 13 +- fs/btrfs/qgroup.c | 3 + fs/btrfs/relocation.c | 3 + fs/btrfs/super.c | 27 ++- fs/btrfs/transaction.c | 4 +- include/uapi/linux/btrfs.h | 5 + 19 files changed, 1420 insertions(+), 176 deletions(-) -- 1.7.7 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
