fix-for-cache-consistency-on-linux-24-smp-systems-20010315

"Here are the symptoms.  I have 2 OpenAFS  Linux 2.4 machines, one SMP and
one not.
--With both of them I access a series of directories and files within
(/afs/w/x/y/z/).
--I then move to the root directory.
--From a third machine, I remove the directories x, y, and z. Then re-add
them (same names) with some other files.
--From the SMP box, I do an ls in /afs/w and see x.  But x is inaccessible.
--From the UP box I can see and access x.
"

====================
This delta was composed from multiple commits as part of the CVS->Git migration.
The checkin message with each commit was inconsistent.
The following are the additional commit messages.
====================
Missed earlier: not part of the IBM delta.

====================
Part of the alpha patch slipped into the delta; Revert to previous
revision

src/afs/LINUX/osi_vnodeops.c

@@ -628,6 +628,16 @@ static int afs_linux_revalidate(struct dentry *dp)
 	return 0;
     }
 
+    /* Drop the dentry if the callback is broken */
+    if (!(vcp->states & CStatd)) {
+        d_drop(dp); 
+#ifdef AFS_LINUX24_ENV
+	unlock_kernel();
+#endif
+        AFS_GUNLOCK();
+        return 0;
+    }
+
     /* Make this a fast path (no crref), since it's called so often. */
     if (vcp->states & CStatd) {
         if (*dp->d_name.name != '/' && vcp->mvstat == 2) /* root vnode */