Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs

* 'for-linus' of git://oss.sgi.com/xfs/xfs:
  xfs: optimize the negative xattr caching
  xfs: prevent against ioend livelocks in xfs_file_fsync
  xfs: flag all buffers as metadata
  xfs: encapsulate a block of debug code