[gpfsug-discuss] GPFS API

[Jonathan Buzzard]

On 17/12/2018 17:35, Simon Thompson wrote:
> Indeed.
> 
> Actually this was exactly what we were trying to work out. We'd set
> the buf size to 0 hoping it would tell us how much we need, but we
> kept getting EINVAL back - which the docs states is invalid path, but
> actually it can be invalid bufsize as well apparently (the header
> file comments are different again to the docs).
>  

Well duh, if you pass in a zero sized buffer, then there is no space to 
pass the size back because it's in the first four bytes of the returned 
buffer. Further it needs to be big enough to hold the main fields 
otherwise did you request POSIX or NFSv4 ACL's etc.

> Anyway, we're looking at patching mpifileutils to support GPFS ACLs
> to help wi th migration of between old and new file-systems.
> 
> I was actually using the opaque call on the assumption that it would
> be a binary blob of data I could poke to the new file. (I was too
> scared to use the attr functions as that copies DMAPI info as well
> and I'm not sure I want to "copy" my ILM files without recall!).
> 
> Its not clear what DEFAULT and ACCESS ACLs are. I'm guessing
> something to do with inheritance maybe?
> 

A default ACL is the default ACL that would be given to the file. Access 
ACL's are all the other ones. That is pretty basic ACL stuff.

I would really like some info on the  v4Level1_t stuff, as I ma 
reluctant to release my mmsetfacl code until I do.

JAB.

-- 
Jonathan A. Buzzard                         Tel: +44141-5483420
HPC System Administrator, ARCHIE-WeSt.
University of Strathclyde, John Anderson Building, Glasgow. G4 0NG