[PATCH] pathname cleanups

[Jeremy Allison]

On Fri, May 19, 2017 at 08:37:03AM +0200, Volker Lendecke wrote:
> To support the dumb clients the heuristic would have to be to try
> inserting @GMT at all places where / now is if we lose the place the
> client sent the @GMT initially. We can't rely on the flag being set I
> believe. We're talking FreeBSD, (I believe AIX) and other custom SMB
> clients that used to work.

With my patch, for clients that don't set the flag, we will preserve the place
they sent the @GMT as smbd will no longer canonicalize the path and it will
be passed down into the VFS as a regular pathname as before.

Then the underlying shadow_copy module can then cope with the strangeness
as required.

Longer term though we have to stop supporting odd clients that don't
set the FLAGS2_REPARSE_PATH flag to mean 'access previous version' - the
complexity of supporting that in our code is an engineering burdon we simply
cannot bear going forward. Especially for a deprecated protocol (SMB1) and
as SMB2 supports previous versions without any pathname modification.