Re: [PATCH] SUNRPC: use request size to initialize bio_vec in svc_udp_sendto()

From: Chuck Lever <chuck.lever@oracle.com>
To: Lucas Stach <l.stach@pengutronix.de>
Cc: Jeff Layton <jlayton@kernel.org>, Neil Brown <neilb@suse.de>,
	Olga Kornievskaia <kolga@netapp.com>,
	Dai Ngo <Dai.Ngo@oracle.com>, Tom Talpey <tom@talpey.com>,
	Trond Myklebust <trond.myklebust@hammerspace.com>,
	Anna Schumaker <anna@kernel.org>,
	linux-nfs@vger.kernel.org, netdev@vger.kernel.org,
	kernel@pengutronix.de, patchwork-lst@pengutronix.de
Subject: Re: [PATCH] SUNRPC: use request size to initialize bio_vec in svc_udp_sendto()
Date: Wed, 17 Jan 2024 17:03:06 -0500	[thread overview]
Message-ID: <ZahOmmMZxHcK8Amn@tissot.1015granger.net> (raw)
In-Reply-To: <20240117210628.1534046-1-l.stach@pengutronix.de>

On Wed, Jan 17, 2024 at 10:06:28PM +0100, Lucas Stach wrote:
> Use the proper size when setting up the bio_vec, as otherwise only
> zero-length UDP packets will be sent.
> 
> Fixes: baabf59c2414 ("SUNRPC: Convert svc_udp_sendto() to use the per-socket bio_vec array")
> Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
> ---
>  net/sunrpc/svcsock.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
> index 998687421fa6..e0ce4276274b 100644
> --- a/net/sunrpc/svcsock.c
> +++ b/net/sunrpc/svcsock.c
> @@ -717,12 +717,12 @@ static int svc_udp_sendto(struct svc_rqst *rqstp)
>  				ARRAY_SIZE(rqstp->rq_bvec), xdr);
>  
>  	iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, rqstp->rq_bvec,
> -		      count, 0);
> +		      count, rqstp->rq_res.len);
>  	err = sock_sendmsg(svsk->sk_sock, &msg);
>  	if (err == -ECONNREFUSED) {
>  		/* ICMP error on earlier request. */
>  		iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, rqstp->rq_bvec,
> -			      count, 0);
> +			      count, rqstp->rq_res.len);
>  		err = sock_sendmsg(svsk->sk_sock, &msg);
>  	}
>  
> -- 
> 2.43.0
> 

I can't fathom why I would have chosen zero for the @count argument.

We currently have zero test coverage for UDP. I'll look into that.

I've applied this to the nfsd-fixes branch. It should appear in
v6.8-rc if I can get it tested.

-- 
Chuck Lever