Re: [PATCH v2] nfs41: change PNFS_LAYOUTRET_ON_SETATTR to only return on truncation to smaller size

[Christoph Hellwig <hch@lst.de>]

On Sun, Sep 14, 2014 at 01:49:34PM +0300, Boaz Harrosh wrote:
> This is in violation of the pnf-objects draft.

Ithought that's an RFC by now? :)

> We are obliged
> on chown to return layouts because of how the CAPs work, they
> have an embedded CAPs version which might increment when chown
> is changed, and also the credential keys. Which means that using
> the old layout will return an E_ACCESS from the OSD.

This is a good enough argument to just split the flags into one
for chown and one for truncate.  Can you confirm that any other
setattr but a truncate to a smaller size or chown is fine with
your interpretation of RFC5664?

> But..
> 
> I will agree with this patch. The above is true in an OSD
> protocol higher then NO_SEC. But none of the current implementation
> support anything other then NO_SEC.
> 
> Second also with none-NO_SEC once a client does a chown the server
> needs to RECALL all other clients, so as Peng says above the Server
> should/can also recall from us.
> 
> But some good sole needs to make an errata at the RFC draft so to
> explain.

I'd rather not violate the existing RFC unless we have a good reason for it
and an errata out.  Having a flag to return on chown for the object layout
seems like the easier way to go forward.