nspawn: optionally, automatically allocated --bind=/--overlay source from /var/tmp

This extends the --bind= and --overlay= syntax so that an empty string as source/upper
directory is taken as request to automatically allocate a temporary directory
below /var/tmp, whose lifetime is bound to the nspawn runtime. In combination
with the "+" path extension this permits a switch "--overlay=+/var::/var" in
order to use the container's shipped /var, combine it with a writable temporary
directory and mount it to the runtime /var of the container.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/nspawn/nspawn-mount.h b/src/nspawn/nspawn-mount.h
index dc8be438ac..467082a737 100644
--- a/src/nspawn/nspawn-mount.h
+++ b/src/nspawn/nspawn-mount.h
@@ -56,6 +56,7 @@ typedef struct CustomMount {
         char *options;
         char *work_dir;
         char **lower;
+        char *rm_rf_tmpdir;
 } CustomMount;
 
 CustomMount* custom_mount_add(CustomMount **l, unsigned *n, CustomMountType t);