[Lxc-users] [PATCH 2/2] Accurately detect whether a system supports clone_children

[Serge E. Hallyn]

If multiple cgroups are mounted under /sys/fs/cgroup, then the
original check ends up looking for /sys/fs/cgroup/cgroup.clone_children,
which does not exist because that is just a tmpfs.

So make sure to check an actual cgroupfs.

Signed-off-by: Serge Hallyn <serge.hallyn at canonical.com>
---
 src/lxc/lxc-checkconfig.in |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)

diff --git a/src/lxc/lxc-checkconfig.in b/src/lxc/lxc-checkconfig.in
index 5dcf3a4..30f6186 100755
--- a/src/lxc/lxc-checkconfig.in
+++ b/src/lxc/lxc-checkconfig.in
@@ -63,7 +63,12 @@ echo -n "Multiple /dev/pts instances: " && is_enabled DEVPTS_MULTIPLE_INSTANCES
 echo
 echo "--- Control groups ---"
 
-CGROUP_MNT_PATH=$(grep -m1 "^cgroup" /proc/self/mounts | awk '{ print $2 }')
+print_cgroups() {
+  # print all mountpoints for cgroup filesystems
+  awk '$1 !~ /#/ && $3 == mp { print $2; } ; END { exit(0); } '  "mp=$1" "$2" ;
+}
+
+CGROUP_MNT_PATH=`print_cgroups cgroup /proc/self/mounts | head -1`
 
 echo -n "Cgroup: " && is_enabled CONFIG_CGROUPS yes
 
-- 
1.7.5.4