[PATCH] libmachdev: Introduce startup notification for clean rumpdisk shutdown

[Damien Zammit]

This still does not work.  I get a freeze on reboot command:

root@zamhurd:~# reboot
INIT: Switching to runlevel: 6
INIT: Sending processes configured via /etc/inittab the TERM signal
root@zamhurd:~#
Broadcast message from root@zamhurd (console) (Sun Jul 25 16:32:28 1999):

The system is going down for reboot NOW!
INIT: Sending processes configured via /etc/inittab the KILL signal
Using makefile-style concurrent boot in runlevel 6.
Stopping deferred execution scheduler: atd.
Asking all remaining processes to terminate...

<HANG>

---
 libmachdev/Makefile        |  6 ++--
 libmachdev/startup-ops.c   | 36 +++++++++++++++++++++++
 libmachdev/startup.c       | 58 ++++++++++++++++++++++++++++++++++++++
 libmachdev/startup.h       | 28 ++++++++++++++++++
 libmachdev/trivfs_server.c |  8 ++++--
 libmachdev/trivfs_server.h | 30 ++++++++++++++++++++
 6 files changed, 161 insertions(+), 5 deletions(-)
 create mode 100644 libmachdev/startup-ops.c
 create mode 100644 libmachdev/startup.c
 create mode 100644 libmachdev/startup.h
 create mode 100644 libmachdev/trivfs_server.h

diff --git a/libmachdev/Makefile b/libmachdev/Makefile
index 15b98cf1..a111a2eb 100644
--- a/libmachdev/Makefile
+++ b/libmachdev/Makefile
@@ -19,10 +19,10 @@ dir := libmachdev
 makemode := library
 libname = libmachdev
 
-SRCS = ds_routines.c trivfs_server.c \
-       deviceServer.c notifyServer.c mach_i386Server.c
+SRCS = ds_routines.c trivfs_server.c startup_notifyServer.c \
+       deviceServer.c notifyServer.c mach_i386Server.c startup.c startup-ops.c
 
-LCLHDRS = machdev.h machdev-device_emul.h machdev-dev_hdr.h mach_device.h
+LCLHDRS = machdev.h machdev-device_emul.h machdev-dev_hdr.h mach_device.h 
startup.h
 installhdrs = machdev.h machdev-device_emul.h machdev-dev_hdr.h
 HURDLIBS = ports trivfs
 LDLIBS += -lpthread -lmachuser
diff --git a/libmachdev/startup-ops.c b/libmachdev/startup-ops.c
new file mode 100644
index 00000000..5d46c217
--- /dev/null
+++ b/libmachdev/startup-ops.c
@@ -0,0 +1,36 @@
+/*
+   Copyright (C) 2020 Free Software Foundation, Inc.
+
+   The GNU Hurd is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2, or (at
+   your option) any later version.
+
+   The GNU Hurd is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with the GNU Hurd.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <startup_notify_S.h>
+#include <hurd/trivfs.h>
+#include "startup.h"
+#include "trivfs_server.h"
+
+/* The system is going down. Call trivfs_goaway() */
+error_t
+S_startup_dosync (mach_port_t handle)
+{
+  struct port_info *inpi = ports_lookup_port (port_bucket, handle,
+                                             machdev_shutdown_notify_class);
+
+  if (!inpi)
+    return EOPNOTSUPP;
+
+  ports_port_deref (inpi);
+
+  return trivfs_goaway (NULL, FSYS_GOAWAY_FORCE);
+}
diff --git a/libmachdev/startup.c b/libmachdev/startup.c
new file mode 100644
index 00000000..fee5a665
--- /dev/null
+++ b/libmachdev/startup.c
@@ -0,0 +1,58 @@
+/*
+   Copyright (C) 2020 Free Software Foundation, Inc.
+
+   The GNU Hurd is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2, or (at
+   your option) any later version.
+
+   The GNU Hurd is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with the GNU Hurd.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/* Startup and shutdown notifications management */
+
+#include "startup.h"
+#include "trivfs_server.h"
+
+#include <unistd.h>
+#include <hurd/paths.h>
+#include <hurd/startup.h>
+#include <hurd/trivfs.h>
+
+struct port_class *machdev_shutdown_notify_class;
+
+void
+arrange_shutdown_notification ()
+{
+  error_t err;
+  mach_port_t initport, notify;
+  struct port_info *pi;
+
+  machdev_shutdown_notify_class = ports_create_class (0, 0);
+
+  /* Arrange to get notified when the system goes down,
+     but if we fail for some reason, just silently give up.  No big deal. */
+
+  err = ports_create_port (machdev_shutdown_notify_class, port_bucket,
+                          sizeof (struct port_info), &pi);
+  if (err)
+    return;
+
+  initport = file_name_lookup (_SERVERS_STARTUP, 0, 0);
+  if (initport == MACH_PORT_NULL)
+    return;
+
+  notify = ports_get_send_right (pi);
+  ports_port_deref (pi);
+  startup_request_notification (initport, notify,
+                               MACH_MSG_TYPE_MAKE_SEND,
+                               program_invocation_short_name);
+  mach_port_deallocate (mach_task_self (), notify);
+  mach_port_deallocate (mach_task_self (), initport);
+}
diff --git a/libmachdev/startup.h b/libmachdev/startup.h
new file mode 100644
index 00000000..2bc6b1d7
--- /dev/null
+++ b/libmachdev/startup.h
@@ -0,0 +1,28 @@
+/*
+   Copyright (C) 2020 Free Software Foundation, Inc.
+
+   The GNU Hurd is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2, or (at
+   your option) any later version.
+
+   The GNU Hurd is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with the GNU Hurd.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef STARTUP_H
+#define STARTUP_H
+
+/* Startup and shutdown notifications management */
+
+/* Port class for startup requests */
+extern struct port_class *machdev_shutdown_notify_class;
+
+void arrange_shutdown_notification (void);
+
+#endif /* STARTUP_H */
diff --git a/libmachdev/trivfs_server.c b/libmachdev/trivfs_server.c
index 93d498ad..64f447b9 100644
--- a/libmachdev/trivfs_server.c
+++ b/libmachdev/trivfs_server.c
@@ -30,12 +30,14 @@
 #include <device/device.h> /* mach console */
 
 #include "libdiskfs/diskfs.h"
+#include "startup.h"
+#include "startup_notify_S.h"
 #include "device_S.h"
 #include "notify_S.h"
 #include "fsys_S.h"
 #include "mach_i386_S.h"
 
-static struct port_bucket *port_bucket;
+struct port_bucket *port_bucket;
 
 /* Trivfs hooks.  */
 int trivfs_fstype = FSTYPE_MISC;
@@ -194,7 +196,6 @@ S_i386_io_perm_create (mach_port_t master_port,
   return i386_io_perm_create (_hurd_device_master, from, to, io_perm);
 }
 
-/* This is fraud */
 kern_return_t
 trivfs_S_fsys_startup (mach_port_t bootport,
                        mach_port_t reply,
@@ -204,6 +205,8 @@ trivfs_S_fsys_startup (mach_port_t bootport,
                        mach_port_t *realnode,
                        mach_msg_type_name_t *realnodetype)
 {
+  arrange_shutdown_notification ();
+
   *realnode = MACH_PORT_NULL;
   *realnodetype = MACH_MSG_TYPE_MOVE_SEND;
   return 0;
@@ -327,6 +330,7 @@ demuxer (mach_msg_header_t *inp, mach_msg_header_t *outp)
   if ((routine = device_server_routine (inp)) ||
       (routine = notify_server_routine (inp)) ||
       (routine = mach_i386_server_routine (inp)) ||
+      (routine = startup_notify_server_routine (inp)) ||
       (routine = NULL, trivfs_demuxer (inp, outp)))
     {
       if (routine)
diff --git a/libmachdev/trivfs_server.h b/libmachdev/trivfs_server.h
new file mode 100644
index 00000000..908feaf6
--- /dev/null
+++ b/libmachdev/trivfs_server.h
@@ -0,0 +1,30 @@
+/*
+   Copyright (C) 2020 Free Software Foundation, Inc.
+
+   The GNU Hurd is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   The GNU Hurd is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with the GNU Hurd; see the file COPYING.  If not, write to
+   the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+#ifndef _TRIVFS_SERVER_H
+#define _TRIVFS_SERVER_H
+
+#include <hurd/ports.h>
+#include <hurd/trivfs.h>
+#include <hurd.h>
+
+extern struct port_bucket *port_bucket;
+extern struct port_class *trivfs_protid_class;
+extern struct port_class *trivfs_cntl_class;
+
+#endif
+
-- 
2.25.1