Better logging in vtrpc, publish cache statistics.

include/venti.h

@@ -369,6 +369,7 @@ void vtrespond(VtReq*);
 
 /* client */
 Packet *vtrpc(VtConn*, Packet*);
+Packet *_vtrpc(VtConn*, Packet*, VtFcall*);
 void vtrecvproc(void*);	/* VtConn* */
 void vtsendproc(void*);	/* VtConn* */
 
@@ -428,6 +429,8 @@ int vtblockwrite(VtBlock*);
 VtBlock *vtblockcopy(VtBlock*);
 void vtblockduplock(VtBlock*);
 
+extern int vtcachencopy, vtcachenread, vtcachenwrite;
+
 /*
  * Hash tree file tree.
  */