NFSv4: Add tracepoints for debugging delegations

Set up tracepoints to track when delegations are set, reclaimed,
returned by the client, or recalled by the server.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/callback_proc.c

@@ -15,6 +15,7 @@
 #include "internal.h"
 #include "pnfs.h"
 #include "nfs4session.h"
+#include "nfs4trace.h"
 
 #ifdef NFS_DEBUG
 #define NFSDBG_FACILITY NFSDBG_CALLBACK
@@ -93,6 +94,7 @@ __be32 nfs4_callback_recall(struct cb_recallargs *args, void *dummy,
 	default:
 		res = htonl(NFS4ERR_RESOURCE);
 	}
+	trace_nfs4_recall_delegation(inode, -ntohl(res));
 	iput(inode);
 out:
 	dprintk("%s: exit with status = %d\n", __func__, ntohl(res));