MFC r198291:

Unloading of the nfscl module is unsupported because newnfslock doesn't
support unloading. It's not trivial to implement newnfslock unloading so
for now just admit that unloading is unsupported and refuse to attempt
unload in all nfscl module event handlers.

Approved by:	trasz (mentor)

sys/fs/nfsclient/nfs_clport.c

@@ -1243,6 +1243,10 @@ nfscl_modevent(module_t mod, int type, void *data)
 			break;
 		}
 
+		/*
+		 * XXX: Unloading of nfscl module is unsupported.
+		 */
+#if 0
 		ncl_call_invalcaches = NULL;
 		nfsd_call_nfscl = NULL;
 		/* and get rid of the mutexes */
@@ -1250,6 +1254,9 @@ nfscl_modevent(module_t mod, int type, void *data)
 		mtx_destroy(&ncl_iod_mutex);
 		loaded = 0;
 		break;
+#else
+		/* FALLTHROUGH */
+#endif
 	default:
 		error = EOPNOTSUPP;
 		break;

sys/fs/nfsclient/nfs_clsubs.c

@@ -87,6 +87,10 @@ extern struct nfsstats newnfsstats;
 int
 ncl_uninit(struct vfsconf *vfsp)
 {
+	/*
+	 * XXX: Unloading of nfscl module is unsupported.
+	 */
+#if 0
 	int i;
 
 	/*
@@ -104,6 +108,9 @@ ncl_uninit(struct vfsconf *vfsp)
 	mtx_unlock(&ncl_iod_mutex);
 	ncl_nhuninit();
 	return (0);
+#else
+	return (EOPNOTSUPP);
+#endif
 }
 
 void