Index: head/sys/kern/vfs_bio.c
===================================================================
--- head/sys/kern/vfs_bio.c
+++ head/sys/kern/vfs_bio.c
@@ -72,7 +72,7 @@
 #include <sys/rwlock.h>
 #include <sys/smp.h>
 #include <sys/sysctl.h>
-#include <sys/sysproto.h>
+#include <sys/syscallsubr.h>
 #include <sys/vmem.h>
 #include <sys/vmmeter.h>
 #include <sys/vnode.h>
@@ -1342,7 +1342,7 @@
 	 * Sync filesystems for shutdown
 	 */
 	wdog_kern_pat(WD_LASTVAL);
-	sys_sync(curthread, NULL);
+	kern_sync(curthread);
 
 	/*
 	 * With soft updates, some buffers that are
@@ -1369,7 +1369,7 @@
 		pbusy = nbusy;
 
 		wdog_kern_pat(WD_LASTVAL);
-		sys_sync(curthread, NULL);
+		kern_sync(curthread);
 
 #ifdef PREEMPTION
 		/*
Index: head/sys/kern/vfs_syscalls.c
===================================================================
--- head/sys/kern/vfs_syscalls.c
+++ head/sys/kern/vfs_syscalls.c
@@ -114,17 +114,8 @@
 static int kern_linkat_vp(struct thread *td, struct vnode *vp, int fd,
     const char *path, enum uio_seg segflag);
 
-/*
- * Sync each mounted filesystem.
- */
-#ifndef _SYS_SYSPROTO_H_
-struct sync_args {
-	int     dummy;
-};
-#endif
-/* ARGSUSED */
 int
-sys_sync(struct thread *td, struct sync_args *uap)
+kern_sync(struct thread *td)
 {
 	struct mount *mp, *nmp;
 	int save;
@@ -149,6 +140,22 @@
 	}
 	mtx_unlock(&mountlist_mtx);
 	return (0);
+}
+
+/*
+ * Sync each mounted filesystem.
+ */
+#ifndef _SYS_SYSPROTO_H_
+struct sync_args {
+	int     dummy;
+};
+#endif
+/* ARGSUSED */
+int
+sys_sync(struct thread *td, struct sync_args *uap)
+{
+
+	return (kern_sync(td));
 }
 
 /*
Index: head/sys/sys/syscallsubr.h
===================================================================
--- head/sys/sys/syscallsubr.h
+++ head/sys/sys/syscallsubr.h
@@ -276,6 +276,7 @@
 	    struct statfs *buf);
 int	kern_symlinkat(struct thread *td, const char *path1, int fd,
 	    const char *path2, enum uio_seg segflg);
+int	kern_sync(struct thread *td);
 int	kern_ktimer_create(struct thread *td, clockid_t clock_id,
 	    struct sigevent *evp, int *timerid, int preset_id);
 int	kern_ktimer_delete(struct thread *, int);