NFSv4: Add a tracepoint for CB_LAYOUTRECALL

Only support for single file layoutrecall for now.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index 07258d2..b85cf7a 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -41,7 +41,7 @@
 
 	inode = nfs_delegation_find_inode(cps->clp, &args->fh);
 	if (inode == NULL) {
-		trace_nfs4_cb_getattr(cps->clp, &args->fh, inode,
+		trace_nfs4_cb_getattr(cps->clp, &args->fh, NULL,
 				-ntohl(res->status));
 		goto out;
 	}
@@ -198,6 +198,7 @@
 	spin_unlock(&ino->i_lock);
 	pnfs_free_lseg_list(&free_me_list);
 	pnfs_put_layout_hdr(lo);
+	trace_nfs4_cb_layoutrecall_inode(clp, &args->cbl_fh, ino, -rv);
 	iput(ino);
 out:
 	return rv;