Deal with broken Tru64 servers that send different fsids
(due to sign extensions) by sign extending the received
fsid and then doing the comparison.

Signed-off-by: Steve Dickson <steved@redhat.com>
Acked-by: Peter Staubach <staubach@redhat.com>

--- linux-2.6.18.i686/include/linux/nfs_xdr.h.orig	2007-03-05 11:13:35.000000000 -0500
+++ linux-2.6.18.i686/include/linux/nfs_xdr.h	2007-03-05 13:23:00.000000000 -0500
@@ -21,10 +21,26 @@ struct nfs_fsid {
 
 /*
  * Helper for checking equality between 2 fsids.
+ * Hack Alert:
+ * Due do broken Tru64 servers sending sign extend
+ * 32bit fsids in most but _not_ all procedures, 
+ * we need to be a bit clever as well as make an 
+ * assumption when comparing fsids.
+ *
+ * If the assumption can be made that the bottom 32 bits 
+ * of an fsids will *always* change when the fsid changes
+ * then it should be safe to only look at the bottom 32 bits
+ * during a 64bit comparison.
+ *
+ * So by sign extending the fsid we just received (i.e. b->major) 
+ * and then do the comparison, we are still going a 64bit
+ * comparison but only really "looking at" the bottom 32 bits.
  */
 static inline int nfs_fsid_equal(const struct nfs_fsid *a, const struct nfs_fsid *b)
 {
-	return a->major == b->major && a->minor == b->minor;
+	return (a->major == b->major || 
+	    a->major == (uint64_t)((int64_t)((int32_t)(b->major & 0xffffffff)))) &&
+		a->minor == b->minor;
 }
 
 struct nfs_fattr {