xfs_seek_data() refinement with unwritten extents check up from page cache.
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>