Re: [PATCH] NFSD: drop support for ancient file-handles

[Christoph Hellwig <hch@lst.de>]

On Thu, Aug 26, 2021 at 02:28:15PM +1000, NeilBrown wrote:
> This patch also moves the nfsfh.h from the include/uapi directory into
> fs/nfsd.  I can find no evidence of it being used anywhere outside the
> kernel.  Certainly nfs-utils and wireshark do not use it.

That sounds fine, but I'd split this into a separate patch.

> fh_base and fh_pad are occasionally used to refer to the whole
> filehandle.  These are replaced with "fh_raw" which is hopefully more
> meaningful.

I think that kind of cleanup should also be a separate patch.  That
being said as far as I can tell fh_raw is only ever used in context
where we can just pass a void pointer.  So just giving the struct
for the "new" file handle after fh_size a name and passing that
would be much cleaner than a union with a char array.


> I found
>  https://www.spinics.net/lists/linux-nfs/msg43280.html
>  "Re: [PATCH] nfsd: clean up fh_auth usage"
> from 2014 where moving nfsfh.h out of uapi was considered but not
> actioned. Christoph said he would "do some research if the
> uapi <linux/nfsd/*.h> headers are used anywhere at all".  I can find no
> report on the result of that research.  My own research turned up
> nothing.

I can't remember doing much of research, and certainly not of finding
anything.

> -	memcpy((char*)&fh.fh_handle.fh_base, f->data, f->size);
> +	memcpy((char*)&fh.fh_handle.fh_raw, f->data, f->size);

Indedpendnt on what we're going to pass here, I don't think we
should need cast like this one (there are a few more).