Index: sys/kern/vfs_syscalls.c
===================================================================
--- sys/kern/vfs_syscalls.c
+++ sys/kern/vfs_syscalls.c
@@ -480,7 +480,8 @@
 			continue;
 		}
 #endif
-		if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) {
+		if (vfs_busy(mp, ((flags & MNT_WAIT) ? 0 : MBF_NOWAIT) |
+		    MBF_MNTLSTLOCK)) {
 			nmp = TAILQ_NEXT(mp, mnt_list);
 			continue;
 		}