Request For Comments: emulation of Windows file attributes on POSIX

[Keith Matthews]

On Fri, 10 May 2002 00:03:12 +0200 Jakob Eriksson <Jakob Eriksson <jakob at vmlinux.org>> wrote:

> 


> I filed a bug that comments Wine can't create a HIDDEN file,
> so that Wine does not later find it with FindFirstFile().


> http://bugs.winehq.com/show_bug.cgi?id=660

> there was a little discussion there and I suggested
> a) a mode where Wine reads the special info from VFAT and NTFS filesystems.
> 	(linux kernel enhancement probably necessary)

> b) for POSIX filesystems, an emulation layer where Wine emulates the
> 	attributes by storing them in a special file in each directory.

> Andriy Palamarchuk commented with this:

> 	There are plans on integration with Samba and this functionality can be
> 	implemented there for communication with Windows machines.
> 	However, I can't decide whether it is worth to implement these features for
> 	Posix file system. 
> 	I suggest you to discuss the matter on wine-devel.


> Is it worth it at all?

> Is it worth it if I implement it as a Wine learning exercise and all you Wine
> demigods have to do is either say "ok" or "bad, to slow, let's ditch it" or whatever.

> I don't understand that about Samba integration. Can they read the
> special attributes on VFAT and NTFS? Are they planning to emulate it?

I don't know to what extent others on the list have been tracking
filesystem development in Linux or any other *nix, so this may be well
known to some. I've been looking at it from several respects, one of
which was linking ACLs to filesystem ACLs.

In the Linux area SGI's XFS filesystem already supports ACLs. Work is
under way integrating this with Samba ACLs and the ext3 work being
done by Andreas Grunbacher. JFS does not yet support ACLs in it's
Linux incarnation but the work is on the 'todo' list. I have no
knowledge of the situation wrt ReiserFS. 

I mention this because part of the XFS implementation includes
storage of extended attributes in a form that could be used by
products such as Wine. AFAIK  this does not apply to the other
filesystem types although JFS with its O/S 2 background either should
or should not present much difficulty to the addition. 

EAs would certainly be a way of handling the 'DOS' type attributes
that could not be mapped onto normal Unix attributes. Part of the work
involves producing suitable utilities to correctly handle the EAs
along with the files they relate to. 

Clearly tying Wine in to one f/s type is not a practical option, but
some work in that area by those on the periphery of the project might
fill in the holes in such a way as to resolve issues on all f/s types
(for Linux and other platforms).

--
Keith Matthews
Frequentous Consultants  - Linux Services, 
		Oracle development & database administration