[PATCH] kNFSd: NFSv4: wipe out all evidence in fh_put()

When a filehandle is cleared with fh_put(), wipe out all traces by
clearing ->fh_pre_saved and ->fh_post_saved.  This prevents
fill_post_wcc() from complaining if the filehandle is later reused.
(This could happen in NFSv4 to CURRENT_FH if, for example, LOOKUP LOOKUP
occurs in a COMPOUND.)

fs/nfsd/nfsfh.c

@@ -438,6 +438,10 @@ fh_put(struct svc_fh *fhp)
 		fh_unlock(fhp);
 		fhp->fh_dentry = NULL;
 		dput(dentry);
+#ifdef CONFIG_NFSD_V3
+		fhp->fh_pre_saved = 0;
+		fhp->fh_post_saved = 0;
+#endif
 		nfsd_nr_put++;
 	}
 	return;