From 9704472d1c0edd9b04b294bd975ee3fc35b8c42d Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Wed, 24 Jun 2009 13:33:03 +0000
Subject: [PATCH] Some hacks to support clean shutdowns of VMs that mount the
 Nix store ove QEMU (and other NixOS instances that use a remote filesystem
 like NFS):

* Don't take down the network interfaces during shutdown.
* Don't try to unmount the Nix store.  Usually, this doesn't work
  because it's still in use, but on remote filesystems like CIFS the
  `-f' umount flag actually works.

svn path=/nixos/branches/modular-nixos/; revision=16036
---
 modules/system/upstart-events/halt.nix | 7 ++++++-
 modules/tasks/network-interfaces.nix   | 8 ++++----
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/modules/system/upstart-events/halt.nix b/modules/system/upstart-events/halt.nix
index 60727e3686b..82b5ffcae1a 100644
--- a/modules/system/upstart-events/halt.nix
+++ b/modules/system/upstart-events/halt.nix
@@ -69,7 +69,12 @@ let
               for mp in $(getMountPoints); do
                   device=$(getDevice $mp)
                   echo "unmounting $mp..."
-                  if umount -f -n "$mp"; then
+                  # !!! Don't unmount /nix/store or /hostfs.  This is
+                  # a quick hack to cleanly shutdown VMs that mount
+                  # the Nix store via CIFS.  "mount -f" will actually
+                  # work on such filesystems, which makes all commands
+                  # needed below disappear.
+                  if test "$mp" != /nix/store -a "$mp" != /hostfs && umount -f -n "$mp"; then
                       if test "$mp" != /; then tryAgain=1; fi
                   else
                       mount -n -o remount,ro "$mp" || true
diff --git a/modules/tasks/network-interfaces.nix b/modules/tasks/network-interfaces.nix
index 4c57b48bd94..d075d04ed6b 100644
--- a/modules/tasks/network-interfaces.nix
+++ b/modules/tasks/network-interfaces.nix
@@ -159,10 +159,10 @@ in
       respawn sleep 100000
 
       stop script
-          for i in $(cd /sys/class/net && ls -d *); do
-              echo "Taking down network device $i..."
-              ${nettools}/sbin/ifconfig $i down || true
-          done
+          #for i in $(cd /sys/class/net && ls -d *); do
+          #    echo "Taking down network device $i..."
+          #    ${nettools}/sbin/ifconfig $i down || true
+          #done
       end script
     '';
   }];