1. 15 Jan, 2015 8 commits
  2. 12 Jan, 2015 31 commits
  3. 05 Jan, 2015 1 commit
    • Josef Bacik's avatar
      Btrfs: do not move em to modified list when unpinning · 736ba53d
      Josef Bacik authored
      commit a2804695 upstream.
      
      We use the modified list to keep track of which extents have been modified so we
      know which ones are candidates for logging at fsync() time.  Newly modified
      extents are added to the list at modification time, around the same time the
      ordered extent is created.  We do this so that we don't have to wait for ordered
      extents to complete before we know what we need to log.  The problem is when
      something like this happens
      
      log extent 0-4k on inode 1
      copy csum for 0-4k from ordered extent into log
      sync log
      commit transaction
      log some other extent on inode 1
      ordered extent for 0-4k completes and adds itself onto modified list again
      log changed extents
      see ordered extent for 0-4k has already been logged
      	at this point we assume the csum has been copied
      sync log
      crash
      
      On replay we will see the extent 0-4k in the log, drop the original 0-4k extent
      which is the same one that we are replaying which also drops the csum, and then
      we won't find the csum in the log for that bytenr.  This of course causes us to
      have errors about not having csums for certain ranges of our inode.  So remove
      the modified list manipulation in unpin_extent_cache, any modified extents
      should have been added well before now, and we don't want them re-logged.  This
      fixes my test that I could reliably reproduce this problem with.  Thanks,
      Signed-off-by: default avatarJosef Bacik <jbacik@fb.com>
      Signed-off-by: default avatarChris Mason <clm@fb.com>
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      736ba53d