Re: [PATCH v2 00/13] NFS client user xattr (RFC8276) support

Frank van der Linden
2020-03-26T23:16:19Z

On Thu, Mar 26, 2020 at 08:03:13PM +0100, Mkrtchyan, Tigran wrote:
> The new patchset looks broken to me.
>
> Client quiryes for supported attributes and gets xattr_support bit set:
>
> Mar 26 11:27:07 ani.desy.de kernel: decode_attr_supported: bitmask=fcffbfff:40fdbe3e:00040800
>
> However, the attribute never queries, but client makes is decision:
>
> Mar 26 11:27:07 ani.desy.de kernel: decode_attr_xattrsupport: XATTR support=false
>
> The packets can be found here: https://sas.desy.de/index.php/s/GEPiBxPg3eR4aGA
>
> Can you provide packets of your mount/umount round.

Hi Tigran,

I looked at your packet dump. It seems like your server only supports 4.1,
not 4.2. xattr support builds on 4.2 (within the rules laid out in
RFC 8178).

So, the fsinfo client call, which is just a GETATTR, masks out the 4.2
fattr bits from server->attr_mask, and just uses the 4.1 bits. Meaning that
xattr_support is not included, and defaults to false.

The packet dump also indicates that your server advertises the xattr_support
fattr as supported, even though it's in a 4.1 session, which would not
be correct.

- Frank