MountRule: Aligning behavior with apparmor_parser
Mount Rules with options in { remount, [make-] { [r]unbindable, [r]shared, [r]private, and [r]slave }} do not support specifying a source. This commit aligns utils implementation to apparmor_parser's, which prohibits having a both source and a destination simultaneously, instad of just prohibiting source.
Therefore, both mount options=(unbindable) /a,
and mount options=(unbindable) -> /a,
are now supported (and equivalent for apparmor_parser). However, mount options=(unbindable) /a -> /b,
is invalid.
For the same reason, specifying a fstype in these cases is also prohibited.
Similarly, we prohibit to specify a fstype for bind mount rules.
Fixes: https://bugs.launchpad.net/ubuntu/+source/apparmor/+bug/2065685
Signed-off-by: Maxime Bélair maxime.belair@canonical.com