[lxc-devel] [PATCH] Issue #476: incomplete destruction of unprivileged ephemeral containers

[overlay fs]

If an unprivileged ephemeral container is started as follows,

    lxc-start-ephemeral -o trusty -n test_ephemeral

Then an empty directory remains upon exit from the container,

    ~/.local/share/lxc/test_ephemeral/tmpfs/delta0

(The tmpfs filesystem is successfully unmounted, but we seem to lack
permission to delete the delta0 directory).

This issue arose following commits 4799a1e and dd2271e .

The following patch resolves the issue. It has been tested on ubuntu
14.04 with the lxc-daily ppa.
Since gmail screws up the formatting of the patch via line-wrapping
etc, please copy the patch from the issue-tracker rather than from
this email.

--- /usr/bin/lxc-start-ephemeral        2015-03-18 07:09:22.000000000 +1100
+++ lxc-start-ephemeral 2015-03-22 01:49:10.929867425 +1100
@@ -240,17 +240,15 @@
count = 0
for entry in overlay_dirs:
          tmpdir = "%s/tmpfs" % dest_path
+        fd.write("mkdir -p %s\n" % (tmpdir))
+        if args.storage_type == "tmpfs":
+            fd.write("mount -n -t tmpfs -o mode=0755 none %s\n" % (tmpdir))
          deltdir = "%s/delta%s" % (tmpdir, count)
          workdir = "%s/work%s" % (tmpdir, count)
          fd.write("mkdir -p %s %s\n" % (deltdir, entry[1]))
          if have_new_overlay:
              fd.write("mkdir -p %s\n" % workdir)

-        if args.storage_type == "tmpfs":
-            fd.write("mount -n -t tmpfs -o mode=0755 none %s\n" % (tmpdir))
-            fd.write("mkdir %s\n" % deltdir)
-            fd.write("mkdir %s\n" % workdir)
-
          fd.write("getfacl -a %s | setfacl --set-file=- %s || true\n" %
                   (entry[0], deltdir))
          fd.write("getfacl -a %s | setfacl --set-file=- %s || true\n" %

Signed-off by: Oleg Freedholm <overlayfs at gmail.com>