Merge lp:~jamesodhunt/ubuntu/saucy/sysvinit/force-reload-configuration-for-broken-inotify into lp:ubuntu/saucy/sysvinit

[James Hunt]

* debian/src/sysv-rc/sbin/invoke-rc.d: Call 'initctl reload-configuration'
  to work reliably on systems with broken inotify.

= Note =

The 'reload-configuration' will also be called when invoked from within a chroot.

[James Hunt (jamesodhunt)]

Although the proposed change is safe for all systems, it is only currently necessary on systems where /etc/init/ is on overlayfs. As such, I wonder if we should be checking to see if /etc/init/ is actually on overlayfs prior to calling 'reload-configuration' (since on my system it took ~1 second to run 'reload-configuration' for the first time).

slangasek/smoser may have an opinion on this.

[Martin Pitt (pitti)]

Is that for the live session only? I. e. could we just guard that with

  grep -q '^/cow / overlayfs' /proc/mounts

or something similar?

[Martin Pitt (pitti)]

How about making this more generic:

rootfs=$(awk '{if ($5 == "/") print $8; }' /proc/self/mountinfo)

if [ "$rootfs" = "overlayfs" ]; then
   ... do the reload hack
fi

?

[James Hunt (jamesodhunt)]

Not just live session - it's also used by the cloud images I understand.

[Steve Langasek (vorlon)]

I'm happy with this change as-is. The worst case is the overhead of unnecessarily rereading all of /etc/init. But that's not hugely expensive, and avoiding that overhead while working around the overlayfs problems would still cost us digging around in /proc. So I think we should stick with the smaller change instead of adding extra guards.

review: Approve

Unmerged revisions

193. By James Hunt on 2013-08-17

debian/src/sysv-rc/sbin/invoke-rc.d: Call 'initctl reload-configuration'
to work reliably on systems with broken inotify.

=== modified file 'debian/changelog'
--- debian/changelog	2013-06-04 08:53:47 +0000
+++ debian/changelog	2013-08-17 12:33:46 +0000
@@ -1,3 +1,10 @@
+sysvinit (2.88dsf-41ubuntu4) UNRELEASED; urgency=low
+
+  * debian/src/sysv-rc/sbin/invoke-rc.d: Call 'initctl reload-configuration'
+    to work reliably on systems with broken inotify.
+
+ -- James Hunt <[e-mail]>  Sat, 17 Aug 2013 13:27:22 +0100
+
 sysvinit (2.88dsf-41ubuntu3) saucy; urgency=low
 
   * Exit the ondemand script silently if we are on a system that has

=== modified file 'debian/src/sysv-rc/sbin/invoke-rc.d'
--- debian/src/sysv-rc/sbin/invoke-rc.d	2013-05-28 19:23:43 +0000
+++ debian/src/sysv-rc/sbin/invoke-rc.d	2013-08-17 12:33:46 +0000
@@ -476,6 +476,10 @@
 	    fi
 
 	    if [ -n "$is_upstart" ]; then
+		# Force Upstart to re-scan /etc/init for filesystems with
+		# broken inotify (such as overlayfs (LP: #882147)).
+		initctl reload-configuration >/dev/null 2>&1
+
 		case $saction in
 		    status)
 			"$saction" "$INITSCRIPTID" && exit 0