1. 06 1月, 2009 3 次提交
  2. 12 12月, 2008 1 次提交
  3. 02 12月, 2008 2 次提交
  4. 20 11月, 2008 1 次提交
  5. 18 11月, 2008 2 次提交
    • C
      Btrfs: Allow subvolumes and snapshots anywhere in the directory tree · 3de4586c
      Chris Mason 提交于
      Before, all snapshots and subvolumes lived in a single flat directory.  This
      was awkward and confusing because the single flat directory was only writable
      with the ioctls.
      
      This commit changes the ioctls to create subvols and snapshots at any
      point in the directory tree.  This requires making separate ioctls for
      snapshot and subvol creation instead of a combining them into one.
      
      The subvol ioctl does:
      
      btrfsctl -S subvol_name parent_dir
      
      After the ioctl is done subvol_name lives inside parent_dir.
      
      The snapshot ioctl does:
      
      btrfsctl -s path_for_snapshot root_to_snapshot
      
      path_for_snapshot can be an absolute or relative path.  btrfsctl breaks it up
      into directory and basename components.
      
      root_to_snapshot can be any file or directory in the FS.  The snapshot
      is taken of the entire root where that file lives.
      Signed-off-by: NChris Mason <chris.mason@oracle.com>
      3de4586c
    • Y
      Btrfs: Seed device support · 2b82032c
      Yan Zheng 提交于
      Seed device is a special btrfs with SEEDING super flag
      set and can only be mounted in read-only mode. Seed
      devices allow people to create new btrfs on top of it.
      
      The new FS contains the same contents as the seed device,
      but it can be mounted in read-write mode.
      
      This patch does the following:
      
      1) split code in btrfs_alloc_chunk into two parts. The first part does makes
      the newly allocated chunk usable, but does not do any operation that modifies
      the chunk tree. The second part does the the chunk tree modifications. This
      division is for the bootstrap step of adding storage to the seed device.
      
      2) Update device management code to handle seed device.
      The basic idea is: For an FS grown from seed devices, its
      seed devices are put into a list. Seed devices are
      opened on demand at mounting time. If any seed device is
      missing or has been changed, btrfs kernel module will
      refuse to mount the FS.
      
      3) make btrfs_find_block_group not return NULL when all
      block groups are read-only.
      Signed-off-by: NYan Zheng <zheng.yan@oracle.com>
      2b82032c
  6. 13 11月, 2008 1 次提交
    • Y
      Btrfs: mount ro and remount support · c146afad
      Yan Zheng 提交于
      This patch adds mount ro and remount support. The main
      changes in patch are: adding btrfs_remount and related
      helper function; splitting the transaction related code
      out of close_ctree into btrfs_commit_super; updating
      allocator to properly handle read only block group.
      Signed-off-by: NYan Zheng <zheng.yan@oracle.com>
      c146afad
  7. 07 11月, 2008 1 次提交
    • C
      Btrfs: Optimize compressed writeback and reads · 771ed689
      Chris Mason 提交于
      When reading compressed extents, try to put pages into the page cache
      for any pages covered by the compressed extent that readpages didn't already
      preload.
      
      Add an async work queue to handle transformations at delayed allocation processing
      time.  Right now this is just compression.  The workflow is:
      
      1) Find offsets in the file marked for delayed allocation
      2) Lock the pages
      3) Lock the state bits
      4) Call the async delalloc code
      
      The async delalloc code clears the state lock bits and delalloc bits.  It is
      important this happens before the range goes into the work queue because
      otherwise it might deadlock with other work queue items that try to lock
      those extent bits.
      
      The file pages are compressed, and if the compression doesn't work the
      pages are written back directly.
      
      An ordered work queue is used to make sure the inodes are written in the same
      order that pdflush or writepages sent them down.
      
      This changes extent_write_cache_pages to let the writepage function
      update the wbc nr_written count.
      Signed-off-by: NChris Mason <chris.mason@oracle.com>
      771ed689
  8. 30 10月, 2008 1 次提交
    • C
      Btrfs: Add zlib compression support · c8b97818
      Chris Mason 提交于
      This is a large change for adding compression on reading and writing,
      both for inline and regular extents.  It does some fairly large
      surgery to the writeback paths.
      
      Compression is off by default and enabled by mount -o compress.  Even
      when the -o compress mount option is not used, it is possible to read
      compressed extents off the disk.
      
      If compression for a given set of pages fails to make them smaller, the
      file is flagged to avoid future compression attempts later.
      
      * While finding delalloc extents, the pages are locked before being sent down
      to the delalloc handler.  This allows the delalloc handler to do complex things
      such as cleaning the pages, marking them writeback and starting IO on their
      behalf.
      
      * Inline extents are inserted at delalloc time now.  This allows us to compress
      the data before inserting the inline extent, and it allows us to insert
      an inline extent that spans multiple pages.
      
      * All of the in-memory extent representations (extent_map.c, ordered-data.c etc)
      are changed to record both an in-memory size and an on disk size, as well
      as a flag for compression.
      
      From a disk format point of view, the extent pointers in the file are changed
      to record the on disk size of a given extent and some encoding flags.
      Space in the disk format is allocated for compression encoding, as well
      as encryption and a generic 'other' field.  Neither the encryption or the
      'other' field are currently used.
      
      In order to limit the amount of data read for a single random read in the
      file, the size of a compressed extent is limited to 128k.  This is a
      software only limit, the disk format supports u64 sized compressed extents.
      
      In order to limit the ram consumed while processing extents, the uncompressed
      size of a compressed extent is limited to 256k.  This is a software only limit
      and will be subject to tuning later.
      
      Checksumming is still done on compressed extents, and it is done on the
      uncompressed version of the data.  This way additional encodings can be
      layered on without having to figure out which encoding to checksum.
      
      Compression happens at delalloc time, which is basically singled threaded because
      it is usually done by a single pdflush thread.  This makes it tricky to
      spread the compression load across all the cpus on the box.  We'll have to
      look at parallel pdflush walks of dirty inodes at a later time.
      
      Decompression is hooked into readpages and it does spread across CPUs nicely.
      Signed-off-by: NChris Mason <chris.mason@oracle.com>
      c8b97818
  9. 30 9月, 2008 1 次提交
    • C
      Btrfs: add and improve comments · d352ac68
      Chris Mason 提交于
      This improves the comments at the top of many functions.  It didn't
      dive into the guts of functions because I was trying to
      avoid merging problems with the new allocator and back reference work.
      
      extent-tree.c and volumes.c were both skipped, and there is definitely
      more work todo in cleaning and commenting the code.
      Signed-off-by: NChris Mason <chris.mason@oracle.com>
      d352ac68
  10. 26 9月, 2008 1 次提交
  11. 25 9月, 2008 26 次提交