fs/ntfs/aops.c::ntfs_write_mst_block(), mft.c::ntfs_sync_mft_mirror(),
        and write_mft_record_nolock().  From now on we require that the
        complete runlist for the mft mirror is always mapped into memory.
      - Add creation of buffers to fs/ntfs/mft.c::ntfs_sync_mft_mirror().
      - Do not check for the page being uptodate in mark_ntfs_record_dirty()
        as we now call this after marking the page not uptodate during mft
        mirror synchronisation (fs/ntfs/mft.c::ntfs_sync_mft_mirror()).
      - Improve error handling in fs/ntfs/aops.c::ntfs_{read,write}_block().
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>