1. 12 Apr, 2011 1 commit
    • Josef Bacik's avatar
      Btrfs: avoid taking the trans_mutex in btrfs_end_transaction · 13c5a93e
      Josef Bacik authored
      I've been working on making our O_DIRECT latency not suck and I noticed we were
      taking the trans_mutex in btrfs_end_transaction.  So to do this we convert
      num_writers and use_count to atomic_t's and just decrement them in
      btrfs_end_transaction.  Instead of deleting the transaction from the trans list
      in put_transaction we do that in btrfs_commit_transaction() since that's the
      only time it actually needs to be removed from the list.  Thanks,
      Signed-off-by: default avatarJosef Bacik <josef@redhat.com>
      13c5a93e
  2. 08 Apr, 2011 8 commits
    • Josef Bacik's avatar
      Btrfs: check for duplicate iov_base's when doing dio reads · 93a54bc4
      Josef Bacik authored
      Apparently it is ok to submit a read to an IDE device with the same target page
      for different offsets.  This is what Windows does under qemu.  The problem is
      under DIO we expect them to be different buffers for checksumming reasons, and
      so this sort of thing will result in checksum errors, when in reality the file
      is fine.  So when reading, check to make sure that all iov bases are different,
      and if they aren't fall back to buffered mode, since that will work out right.
      Thanks,
      Signed-off-by: default avatarJosef Bacik <josef@redhat.com>
      93a54bc4
    • Josef Bacik's avatar
      Btrfs: reuse the extent_map we found when calling btrfs_get_extent · 16d299ac
      Josef Bacik authored
      In btrfs_get_block_direct we call btrfs_get_extent to lookup the extent for the
      range that we are looking for.  If we don't find an extent, btrfs_get_extent
      will insert a extent_map for that area and mark it as a hole.  So it does the
      job of allocating a new extent map and inserting it into the io tree.  But if
      we're creating a new extent we free it up and redo all of that work.  So instead
      pass the em to btrfs_new_extent_direct(), and if it will work just allocate the
      disk space and set it up properly and bypass the freeing/allocating of a new
      extent map and the expensive operation of inserting the thing into the io_tree.
      Thanks,
      Signed-off-by: default avatarJosef Bacik <josef@redhat.com>
      16d299ac
    • Josef Bacik's avatar
      Btrfs: do not use async submit for small DIO io's · 1ae39938
      Josef Bacik authored
      When looking at our DIO performance Chris said that for small IO's doing the
      async submit stuff tends to be more overhead than it's worth.  With this on top
      of my other fixes I get about a 17-20% speedup doing a sequential dd with 4k
      IO's.  Basically if we don't have to split the bio for the map length it's small
      enough to be directly submitted, otherwise go back to the async submit.  Thanks,
      Signed-off-by: default avatarJosef Bacik <josef@redhat.com>
      1ae39938
    • Josef Bacik's avatar
      Btrfs: don't split dio bios if we don't have to · 02f57c7a
      Josef Bacik authored
      We have been unconditionally allocating a new bio and re-adding all pages from
      our original bio to the new bio.  This is needed if our original bio is larger
      than our stripe size, but if it is smaller than the stripe size then there is no
      need to do this.  So check the map length and if we are under that then go ahead
      and submit the original bio.  Thanks,
      Signed-off-by: default avatarJosef Bacik <josef@redhat.com>
      02f57c7a
    • Josef Bacik's avatar
      Btrfs: do not call btrfs_update_inode in endio if nothing changed · 1ef30be1
      Josef Bacik authored
      In the DIO code we often don't update the i_disk_size because the i_size isn't
      updated until after the DIO is completed, so basically we are allocating a path,
      doing a search, and updating the inode item for no reason since nothing changed.
      btrfs_ordered_update_i_size will return 1 if it didn't update i_disk_size, so
      only run btrfs_update_inode if btrfs_ordered_update_i_size returns 0.  Thanks,
      Signed-off-by: default avatarJosef Bacik <josef@redhat.com>
      1ef30be1
    • Josef Bacik's avatar
      Btrfs: map the inode item when doing fill_inode_item · 12ddb96c
      Josef Bacik authored
      Instead of calling kmap_atomic for every thing we set in the inode item, map the
      entire inode item at the start and unmap it at the end.  This makes a sequential
      dd of 400mb O_DIRECT something like 1% faster.  Thanks,
      Signed-off-by: default avatarJosef Bacik <josef@redhat.com>
      12ddb96c
    • Josef Bacik's avatar
      Btrfs: only retry transaction reservation once · 06d5a589
      Josef Bacik authored
      I saw a lockup where we kept getting into this start transaction->commit
      transaction loop because of enospce.  The fact is if we fail to make our
      reservation, we've tried _everything_ several times, so we only need to try and
      commit the transaction once, and if that doesn't work then we really are out of
      space and need to just exit.  Thanks,
      Signed-off-by: default avatarJosef Bacik <josef@redhat.com>
      06d5a589
    • Josef Bacik's avatar
      Btrfs: deal with the case that we run out of space in the cache · be1a12a0
      Josef Bacik authored
      Currently we don't handle running out of space in the cache, so to fix this we
      keep track of how far in the cache we are.  Then we only dirty the pages if we
      successfully modify all of them, otherwise if we have an error or run out of
      space we can just drop them and not worry about the vm writing them out.
      Thanks,
      
      Tested-by Johannes Hirte <johannes.hirte@fem.tu-ilmenau.de>
      Signed-off-by: default avatarJosef Bacik <josef@redhat.com>
      be1a12a0
  3. 05 Apr, 2011 10 commits
  4. 28 Mar, 2011 21 commits