Sounds like this is a kernel bug then? Mounting a filesystem r/o should NEVER modify the disk. Should another bug be created for that and filed upstream?
-- Replaying journals of other OS's filesystems, by mounting them, is unsafe https://launchpad.net/bugs/41624 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
