gpfs 3.5 and Samba Compatibility

[Maxim Kalaev]

> From a brief look, making this change would tie Samba to GPFS
> 3.5. A proper solution should allow a binary of the vfs_gpfs
> module to work with GPFS 3.5 and older versions.
> 
> I am not sure if this can be done automatically, there is always
> the fallback of adding a config option to specify the format.
> When reading an ACL, simply allocating enough space and then
> deciding according to the gpfs_acl header could be
> enough. Writing might be more complicated as the Samba module
> would not know beforehand which format to try.

If not, making separate modules for gpfs v3.4 and newer versions is simple 
and will work as well.
(e.g., having samba modules: vfs_gpfs_3_4 and vfs_gpfs)

Maxim