Patch to add support for advertising FULLSYNC to Mac OSX Clients

[Ralph Böhme]

On Fri, Apr 07, 2017 at 01:20:55PM -0700, Jeremy Allison wrote:
> On Fri, Apr 07, 2017 at 10:13:25PM +0200, Ralph Böhme wrote:
> > On Fri, Apr 07, 2017 at 11:04:04AM -0700, Jeremy Allison wrote:
> > > 
> > > Doesn't this need to be SMB_VFS_FSYNC_SEND() and
> > > the whole thing use the standard async callback
> > > mechanisms ?
> > > 
> > > Looking at https://goo.gl/Lw5bdz it doesn't say we can't
> > > return an intermediate response followed by a completed
> > > response.
> > 
> > It says:
> > 
> >   In response, the server must first process the SMB2 FLUSH command in the usual
> >   manner, and then must flush the data to stable storage (that is, flush the
> >   physical disk’s track cache) before responding to the client.
> >   
> > So we must use the sync sync.
> 
> It says:
> 
> "In response, the server must first process the SMB2 FLUSH command in the usual manner"
> 
> which for us is to go async if it takes longer than our normal
> return time. Can we check with Apple. This is ambiguous, as I can't
> believe their client will fail this if a server goes async. I
> very much doubt the client code is special-cased for this to
> fail if a server goes async. They are just waiting for the
> final response.

My bet is that their server won't go async. We can ask them.

> We should ask for a clarification to:
> 
> "flush the physical disk’s track cache) before making a final
> response to the client".

There's no mention of *final* response in the doc. It just says

  before responding to the client.

I'm reading this as "sync and don't cheat!".

Cheerio!
-slow