Merge lp:~gary/ubuntu/precise/lxc/bug-951150-2 into lp:ubuntu/precise/lxc

[Gary Poster]

It turns out that using an overlayfs as the upperdir of an overlayfs does not work. Files cannot be removed. Perhaps overlayfs does not support xattrs, even though it requires them?

Therefore, this branch adjusts my changes from lp:~gary/ubuntu/precise/lxc/bug-951150 to use a tempfs for the upperdir. Removing files now works.

Thank you

[Serge Hallyn (serge-hallyn)]

Thanks, merged.

review: Approve

=== modified file 'debian/local/lxc-start-ephemeral'
--- debian/local/lxc-start-ephemeral	2012-03-12 09:51:59 +0000
+++ debian/local/lxc-start-ephemeral	2012-03-12 18:16:37 +0000
@@ -40,6 +40,7 @@
         sudo lxc-stop -n $LXC_NAME
     fi
     if [ $LXC_MOUNTED -eq 1 ]; then
+        sudo umount $EPHEMERAL_BIND_DIR
         sudo umount $LXC_DIR
         sudo umount $OVERLAY_DIR
         sudo rmdir $LXC_DIR
@@ -121,6 +122,9 @@
     LXC_DIR=`sudo mktemp -d --tmpdir=/var/lib/lxc $LXC_BASE-temp-XXXXXXX`
     LXC_NAME=`basename $LXC_DIR`
     sudo mount -t overlayfs -oupperdir=$OVERLAY_DIR,lowerdir=/var/lib/lxc/$LXC_BASE none $LXC_DIR
+    EPHEMERAL_BIND_DIR=$LXC_DIR/ephemeralbind
+    sudo mkdir $EPHEMERAL_BIND_DIR
+    sudo mount -t tmpfs none $EPHEMERAL_BIND_DIR
     LXC_MOUNTED=1
 
     # Update the ephemeral lxc's configuration to reflect the new container name.
@@ -140,7 +144,7 @@
             if [ `echo -n $line | awk '{print $4}'` == "bind" ]; then
                 # ...we should rewrite it as an overlay.
                 source=`echo -n $line | awk '{print $1}'`
-                upperdir=$LXC_DIR/ephemeralbind$source
+                upperdir=$EPHEMERAL_BIND_DIR$source
                 sudo mkdir -p $upperdir
                 sudo chown `sudo stat -c '%U.%G' $source` $upperdir
                 echo "none	$path	overlayfs upperdir=$upperdir,lowerdir=$source 0 0";
@@ -237,6 +241,8 @@
     echo "Stopping lxc" >&2
     sudo lxc-stop -n $LXC_NAME
     sleep 2
+    # echo "umounting ephemeral_bind_dir $EPHEMERAL_BIND_DIR" >&2
+    sudo umount $EPHEMERAL_BIND_DIR
     # echo "umounting lxc_dir $LXC_DIR" >&2
     sudo umount $LXC_DIR
     # echo "umounting overlay" >&2