Re: linux-3.14 nfsd regression

["J. Bruce Fields" <bfields@redhat.com>]

On Thu, Apr 03, 2014 at 12:33:55PM -0400, Mark Lord wrote:
> This commit from linux-3.14 breaks our NFS-root clients here:
> 
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=6e14b46b91fee8a049b0940333ce13a820beaaa5
> 
> 
> - *p++ = htonl((u32) stat->mode);
> + *p++ = htonl((u32) (stat->mode & S_IALLUGO));
> 
> 
> Reverting the one-liner above (on the server) fixes it for us,
> as does reverting back to linux-3.13.8 on the server.
> 
> The NFS-root clients are on PowerPC (big-endian) architecture,
> running linux-3.12.16. The NFS server is on an Intel PC running linux-3.14.
> 
> ACL is completely disabled on server and client,
> and we're using NFSv2/v3.  No support for v4.
> 
> I instrumented the function to see what other bits were being cleared
> by the (stat->mode & S_IALLUGO) masking.  The results are attached.

Hm, it sounds like a bug in the client if it's depending on those high
bits.

The original behavior was in practice harmless and changing it broke
something, so I think we should definitely just revert this patch.

But the client may need fixing too.

--b.