[XFS] Don't map non-uptodate buffers in xfs_probe_cluster; also fixes
obscure corruption case

SGI-PV: 942658
SGI-Modid: xfs-linux-melb:xfs-kern:207119a

Signed-off-by: Eric Sandeen <sandeen@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
1 file changed