Work on SMB3 persistent handles

[Jeremy Allison]

On Thu, Nov 16, 2017 at 10:19:03PM +0100, Ralph Böhme via samba-technical wrote:
> Hi Albert,
> 
> On Thu, Nov 09, 2017 at 07:46:29AM +0000, Albert Guo wrote:
> > > 2. The second approach, i.e. “2.1.2 New database for persistent handles”
> > >
> > > After some more tinkering I came to the conclustion that this approach doesn't
> > > work. I've removed it from the design doc.
> 
> > Could you give me a bit more explanation on why you think this approach
> > doesn’t work?
> 
> Because storing the (persistent) handle state is only one part, the other one is
> the FSA state.
> 
> Without extensive filesystem support with a lower level OS API for persistent
> handles and a complete redesign of our durable and future persistent handle
> support on top of that, we have to implement the required FSA state guarantees
> in Samba and in clustered Samba.

When we design the API for the FSA state guarantees for Samba/Clustered Samba
we need to make this pluggable (maybe via VFS calls) in order to allow OEMs
with a filesystem that can make these guarantees directly to call into their
filesystems, whilst the default is to call our own backends.

Just my 2 cents :-).

Jeremy.