Re: [PATCH 24/32] vfs: syscall: Add fsopen() to prepare for superblock creation [ver #9]

[Andy Lutomirski]

> On Jul 12, 2018, at 4:35 PM, David Howells <dhowells@xxxxxxxxxx> wrote:
> 
> Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote:
> 
>> I tend to think that this *should* fail using the new API.  The semantics of
>> the second mount request are bizarre at best.
> 
> You still have to support existing behaviour lest you break userspace.
> 

I assume the existing behavior is that a bind mount is created?  If so, the new mount(8) tool could do it in user code.