[PATCH] Fix for bug #9706 - Parameter is incorrect on Android

[Jeremy Allison]

On Mon, Mar 18, 2013 at 08:38:01PM +0100, Stefan (metze) Metzmacher wrote:
> 
> All tests have shown that it should make no difference if the client
> send CAP_LARGE_READX or CAP_LARGE_WRITEX. Even if the client doesn't
> send it, it's possible to do large reads and write.
> 
> If the client doesn't support large reads or write it would just doesn't
> trigger them, there's really nothing more a client need to tell the server.
> 
> That's why we should should just skip this patch.

That's true for Samba clients to Windows servers. It's not
true for Samba or MacOS clients to Samba servers 3.6.x or
lower. In the v3-6-test code reply_read_and_X() we have:

       if (global_client_caps & CAP_LARGE_READX) {
                size_t upper_size = SVAL(req->vwv+7, 0);

- that's the only place we look at the upper bytes in
a SMBReadX call. So yes, it does matter.

Both older Samba client libraries, MacOSX client, CIFSFS
clients and jCIFS clients all correctly send (or not) the
CAP_LARGE_READX bit on the sessionsetupX request from
the client.

You changed that in the initial 4.0.x client code release.
I think that was a mistake, and we need to put it back. It
doesn't affect how Windows servers behave (or after we fix
this code how Samba servers will behave), but it's the correct
thing to do to inform servers (what they do with that knowledge
is up to them).

I'll keep one email reply per issue, so it's easier
not to have to wade through enourmous email threads :-).

Jeremy.