1. 05 Jan, 2009 5 commits
  2. 19 Dec, 2008 4 commits
  3. 17 Dec, 2008 4 commits
  4. 16 Dec, 2008 1 commit
    • Chris Mason's avatar
      Btrfs: delete checksum items before marking blocks free · dcbdd4dc
      Chris Mason authored
      Btrfs maintains a cache of blocks available for allocation in ram.  The
      code that frees extents was marking the extents free and then deleting
      the checksum items.
      
      This meant it was possible the extent would be reallocated before the
      checksum item was actually deleted, leading to races and other
      problems as the checksums were updated for the newly allocated extent.
      
      The fix is to delete the checksum before marking the extent free.
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      dcbdd4dc
  5. 15 Dec, 2008 2 commits
  6. 12 Dec, 2008 2 commits
    • Yan Zheng's avatar
      Btrfs: fix nodatasum handling in balancing code · 17d217fe
      Yan Zheng authored
      Checksums on data can be disabled by mount option, so it's
      possible some data extents don't have checksums or have
      invalid checksums. This causes trouble for data relocation.
      This patch contains following things to make data relocation
      work.
      
      1) make nodatasum/nodatacow mount option only affects new
      files. Checksums and COW on data are only controlled by the
      inode flags.
      
      2) check the existence of checksum in the nodatacow checker.
      If checksums exist, force COW the data extent. This ensure that
      checksum for a given block is either valid or does not exist.
      
      3) update data relocation code to properly handle the case
      of checksum missing.
      Signed-off-by: default avatarYan Zheng <zheng.yan@oracle.com>
      17d217fe
    • Yan Zheng's avatar
      Btrfs: shared seed device · e4404d6e
      Yan Zheng authored
      This patch makes seed device possible to be shared by
      multiple mounted file systems. The sharing is achieved
      by cloning seed device's btrfs_fs_devices structure.
      Thanks you,
      Signed-off-by: default avatarYan Zheng <zheng.yan@oracle.com>
      e4404d6e
  7. 11 Dec, 2008 3 commits
  8. 10 Dec, 2008 1 commit
    • Chris Mason's avatar
      Btrfs: Delete csum items when freeing extents · 459931ec
      Chris Mason authored
      This finishes off the new checksumming code by removing csum items
      for extents that are no longer in use.
      
      The trick is doing it without racing because a single csum item may
      hold csums for more than one extent.  Extra checks are added to
      btrfs_csum_file_blocks to make sure that we are using the correct
      csum item after dropping locks.
      
      A new btrfs_split_item is added to split a single csum item so it
      can be split without dropping the leaf lock.  This is used to
      remove csum bytes from the middle of an item.
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      459931ec
  9. 09 Dec, 2008 1 commit
  10. 08 Dec, 2008 4 commits
    • Chris Mason's avatar
      Btrfs: Add inode sequence number for NFS and reserved space in a few structs · c3027eb5
      Chris Mason authored
      This adds a sequence number to the btrfs inode that is increased on
      every update.  NFS will be able to use that to detect when an inode has
      changed, without relying on inaccurate time fields.
      
      While we're here, this also:
      
      Puts reserved space into the super block and inode
      
      Adds a log root transid to the super so we can pick the newest super
      based on the fsync log as well as the main transaction ID.  For now
      the log root transid is always zero, but that'll get fixed.
      
      Adds a starting offset to the dev_item.  This will let us do better
      alignment calculations if we know the start of a partition on the disk.
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      c3027eb5
    • Chris Mason's avatar
      Btrfs: Use map_private_extent_buffer during generic_bin_search · 934d375b
      Chris Mason authored
      It is possible that generic_bin_search will be called on a tree block
      that has not been locked.  This happens because cache_block_block skips
      locking on the tree blocks.
      
      Since the tree block isn't locked, we aren't allowed to change
      the extent_buffer->map_token field.  Using map_private_extent_buffer
      avoids any changes to the internal extent buffer fields.
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      934d375b
    • Yan Zheng's avatar
      Btrfs: superblock duplication · a512bbf8
      Yan Zheng authored
      This patch implements superblock duplication. Superblocks
      are stored at offset 16K, 64M and 256G on every devices.
      Spaces used by superblocks are preserved by the allocator,
      which uses a reverse mapping function to find the logical
      addresses that correspond to superblocks. Thank you,
      Signed-off-by: default avatarYan Zheng <zheng.yan@oracle.com>
      a512bbf8
    • Chris Mason's avatar
      Btrfs: move data checksumming into a dedicated tree · d20f7043
      Chris Mason authored
      Btrfs stores checksums for each data block.  Until now, they have
      been stored in the subvolume trees, indexed by the inode that is
      referencing the data block.  This means that when we read the inode,
      we've probably read in at least some checksums as well.
      
      But, this has a few problems:
      
      * The checksums are indexed by logical offset in the file.  When
      compression is on, this means we have to do the expensive checksumming
      on the uncompressed data.  It would be faster if we could checksum
      the compressed data instead.
      
      * If we implement encryption, we'll be checksumming the plain text and
      storing that on disk.  This is significantly less secure.
      
      * For either compression or encryption, we have to get the plain text
      back before we can verify the checksum as correct.  This makes the raid
      layer balancing and extent moving much more expensive.
      
      * It makes the front end caching code more complex, as we have touch
      the subvolume and inodes as we cache extents.
      
      * There is potentitally one copy of the checksum in each subvolume
      referencing an extent.
      
      The solution used here is to store the extent checksums in a dedicated
      tree.  This allows us to index the checksums by phyiscal extent
      start and length.  It means:
      
      * The checksum is against the data stored on disk, after any compression
      or encryption is done.
      
      * The checksum is stored in a central location, and can be verified without
      following back references, or reading inodes.
      
      This makes compression significantly faster by reducing the amount of
      data that needs to be checksummed.  It will also allow much faster
      raid management code in general.
      
      The checksums are indexed by a key with a fixed objectid (a magic value
      in ctree.h) and offset set to the starting byte of the extent.  This
      allows us to copy the checksum items into the fsync log tree directly (or
      any other tree), without having to invent a second format for them.
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      d20f7043
  11. 02 Dec, 2008 13 commits