Move the code for lxcContainerGetSubtree into the virfile
module creating 2 new functions
int virFileGetMountSubtree(const char *mtabpath,
const char *prefix,
char ***mountsret,
size_t *nmountsret);
int virFileGetMountReverseSubtree(const char *mtabpath,
const char *prefix,
char ***mountsret,
size_t *nmountsret);
Add a new virfiletest.c test case to validate the new code.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
