VFS to NTFS transition

[Ralph Böhme]

Shlomi,

thank you for you detailed description. Before I reply with a  
description of what I have in mind regarding netatalk<->samba interop  
I have some comments and questions:

Am 24.04.2008 um 15:03 schrieb Shlomi Yaakobovich:
> In Exanet we use a modified vfs_netatalk object. We call it vfs_ads.  
> It
> includes possible some of the enhancements you are referring to.
>
> As you might know, the vfs_netatalk code is compatible with the
> adouble:v1 format. In short, this format saves Macintosh Resource  
> forks
> under the .AppleDouble folder. Our older tests using this format were
> quite ok, we used it for quite some time.

If I am not totally missing something the code it is also compatible  
with adouble:v2 format which is what netatalk 2 is actually using to  
store the Mac metadata as well as some private data: it is compatible  
because it does nothing more than hide and delete adouble extra files  
if the corresponding (data fork) file is moved (or deleted) through  
Samba.

> However, we wanted to increase interoperability, and we discovered  
> that
> Microsoft treats Resource Forks the same way it handles Resource  
> forks.
> The first stage was to develop the adouble:ads format, and also change
> vfs_netatalk to vfs_ads. The new functionality now saves the Alternate
> Data Streams in the same directory as the Macintsh Resource forks.
> Moreover, all operations by either Mac or Windows clients (e.g.  
> rename,
> delete etc.) are performed well on files with whichever attached
> Resource Fork or Aletrnate Data streams.
>
> Later work was designed to allow Windows clients/application actual
> access to the data inside the resource fork, for example in order to
> show the icon of the picture. This lead to the development of the
> adouble:sfm format in netatalk and to the appropriate changes in
> vfs_ads. Resource Forks are separated into two files in this format:
> AFP_Resource and AFP_AfpInfo. This has its side effects, but does  
> allow
> the required interoperability.

So on the netatalk side: what is the functional difference between  
adouble:v2 and your adouble:sfm? Why didn't you just work with  
adouble:v2?
Just asking out of curiosity and in order to fully undestand your  
implementation.

> We can share the code of course, it is GPL after all !  But the code  
> has
> changed quite much from the vfs_netatalk, and does not compile without
> our changes to samba (which I am not sure you want). However, it is in
> our best interest that our changes will eventually come back to the
> samba code. I would like to know exactly which changes you have had in
> mind, ...

All operations by either Mac or Windows clients (e.g. rename, delete  
etc.) shall be performed well on basis of the current netatalk  
adouble:v2 implementation. Most importantly vfs_netatalk must copy and  
move adouble:v2 files upon SMB copy/move actions.

This and any further anhancemnet is done with the following  
assumptions in mind:
- primary filing protocol for Macs is AFP -- CIFS for Macs is  
considered a bad idea in this setup
- it is unecessary that SMB clients access Mac metadata or ressource  
forks (as you are doing -- which applications actually make use of  
that?)
- Windows alternate data streams are stored wherever the current Samba  
implementation and configuration likes to store it, thats a totally  
different mapping

Regards,
-Ralph