Don't kill processes by signals in process group 0, and do a sync before

killing all processes in FS reboot.

servers/fs/misc.c

@@ -258,6 +258,9 @@ PUBLIC int do_reboot()
   /* Only PM may make this call directly. */
   if (who != PM_PROC_NR) return(EGENERIC);
 
+  /* Sync before the drivers die. */
+  do_sync();
+
   /* Do exit processing for all leftover processes and servers. */
   for (i = 0; i < NR_PROCS; i++) { m_in.slot1 = i; do_exit(); }