linux-kernel - Re: [PATCH v2] nfsd: Implement large extent array support in pNFS

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <aEkouh-uedz1_c4m@infradead.org>
Date: Tue, 10 Jun 2025 23:56:58 -0700
From: Christoph Hellwig <hch@...radead.org>
To: Chuck Lever <chuck.lever@...cle.com>
Cc: Sergey Bashirov <sergeybashirov@...il.com>,
	Christoph Hellwig <hch@...radead.org>,
	Jeff Layton <jlayton@...nel.org>, NeilBrown <neil@...wn.name>,
	Olga Kornievskaia <okorniev@...hat.com>,
	Dai Ngo <Dai.Ngo@...cle.com>, Tom Talpey <tom@...pey.com>,
	linux-nfs@...r.kernel.org, linux-kernel@...r.kernel.org,
	Konstantin Evtushenko <koevtushenko@...dex.com>
Subject: Re: [PATCH v2] nfsd: Implement large extent array support in pNFS

On Tue, Jun 10, 2025 at 02:10:46PM -0400, Chuck Lever wrote:
> > +	if (xdr_stream_decode_u32(argp->xdr, &len) < 0)
> > +		return nfserr_bad_xdr;
> > +	if (!xdr_stream_subsegment(argp->xdr, &lcp->lc_up_layout, len))
> >  		return nfserr_bad_xdr;
> 
> The layout is effectively an opaque payload at this point, so using
> xdr_stream_subsegment() makes sense to me.

Btw, when trying to switch XDR to work with bvec backing,
xdr_stream_subsegment has been a very painful primitive.  I also don't
really understand what the benefit of it is vs just keeping on decoding
the subsegment normally.  That might just be me not understanding the
code, though.