[PATCH 0/3] Add O_DENY* flags to fcntl and cifs

[Theodore Ts'o]

On Thu, Dec 06, 2012 at 11:57:52AM -0800, Jeremy Allison wrote:
> 
> And this is where things get really ugly of course :-).
> 
> For the CIFSFS client they're expecting to be able to
> just ship them to a Windows server, where they'll
> get the (insane) Windows semantics. These semantics
> are not what would be wanted on a local filesystem.

I'm confused; why would a userspace application need to be able to
request this behavior?  I can understand why an SMB client might
depend on this so it can use Windows' insane cache coherency scheme.
Are you trying to let Samba act as a middle man, where a remote file
system is mounted on Linux, and then Samba will try to act as a SMB
server, so you want to be able to pass through these semantics, i.e.:

   Windows SMB Server <--->  Linux cifs remote file system <--->
      Linux Samba server <---> Windows SMB client

Is this somewhat contrivuewd example the intended use case?  Or
something else?

					- Ted