Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote: > > /dev/loop0 /root/loop0-noacl-noquota-nouser_xattr ext4 rw,relatime,nouser_xattr,noacl 0 0 > > /dev/loop0 /root/loop0-acl-quota-user_xattr ext4 rw,relatime,nouser_xattr,noacl 0 0 > > To make sure I understand correctly: the problem is that the second mount > ignored the options because the device was already mounted, right? > > For the new API, I think the only remotely sane approach is to refuse to > mount or init or whatever you call it an already mounted bdev. If user code > genuinely needs to bind-mount an existing mount that is known only by its > bdev, we can add a specific API just for that. I'm adding some flags to fsopen() to allow userspace to say whether it wants no sharing, same parameters-only sharing or anything-goes sharing (as now). I'm also adding a flag whereby userspace can forbid anyone else from sharing a new superblock it has just set up. David