1. 24 Jun, 2016 38 commits
  2. 08 Jun, 2016 2 commits
    • Greg Kroah-Hartman's avatar
      Linux 4.4.13 · ba760d43
      Greg Kroah-Hartman authored
      ba760d43
    • Dave Chinner's avatar
      xfs: handle dquot buffer readahead in log recovery correctly · 55f6ddfc
      Dave Chinner authored
      commit 7d6a13f0 upstream.
      
      When we do dquot readahead in log recovery, we do not use a verifier
      as the underlying buffer may not have dquots in it. e.g. the
      allocation operation hasn't yet been replayed. Hence we do not want
      to fail recovery because we detect an operation to be replayed has
      not been run yet. This problem was addressed for inodes in commit
      d8914002 ("xfs: inode buffers may not be valid during recovery
      readahead") but the problem was not recognised to exist for dquots
      and their buffers as the dquot readahead did not have a verifier.
      
      The result of not using a verifier is that when the buffer is then
      next read to replay a dquot modification, the dquot buffer verifier
      will only be attached to the buffer if *readahead is not complete*.
      Hence we can read the buffer, replay the dquot changes and then add
      it to the delwri submission list without it having a verifier
      attached to it. This then generates warnings in xfs_buf_ioapply(),
      which catches and warns about this case.
      
      Fix this and make it handle the same readahead verifier error cases
      as for inode buffers by adding a new readahead verifier that has a
      write operation as well as a read operation that marks the buffer as
      not done if any corruption is detected.  Also make sure we don't run
      readahead if the dquot buffer has been marked as cancelled by
      recovery.
      
      This will result in readahead either succeeding and the buffer
      having a valid write verifier, or readahead failing and the buffer
      state requiring the subsequent read to resubmit the IO with the new
      verifier.  In either case, this will result in the buffer always
      ending up with a valid write verifier on it.
      
      Note: we also need to fix the inode buffer readahead error handling
      to mark the buffer with EIO. Brian noticed the code I copied from
      there wrong during review, so fix it at the same time. Add comments
      linking the two functions that handle readahead verifier errors
      together so we don't forget this behavioural link in future.
      Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarBrian Foster <bfoster@redhat.com>
      Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      55f6ddfc