[PATCH] smbd: Fix snapshot query on shares with DFS enabled

[Jeremy Allison]

On Wed, Aug 17, 2016 at 02:03:28PM -0700, Jeremy Allison wrote:
> 
> Ah, this might be a clue...
> 
> http://www.snia.org/sites/default/orig/sdc_archives/2008_presentations/thursday/DavidKruse_BeyondCIFS.pdf
> 
>  SMB_FLAGS2_REPARSE_PATH hints that @GMT is present

Been doing some digging, and it seems for SMB1 we
can ignore any @GMT-token in the path if:

FLAGS2_REPARSE_PATH            0x0400

is *NOT* set. At least in master we have
the flags field inside struct smb_filename,
which should allow us to flag any path
containing a @GMT-token to make the
shadow2 and snapper modules much more
efficient (they won't have to strip
paths on every VFS call).

This could help a *lot*, if we plumb
this in via unix_convert() pathname
processing for both SMB1 and SMB2..