Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756441AbcDGOhl (ORCPT ); Thu, 7 Apr 2016 10:37:41 -0400 Received: from arroyo.ext.ti.com ([192.94.94.40]:60311 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753684AbcDGOhj (ORCPT ); Thu, 7 Apr 2016 10:37:39 -0400 Subject: Re: Boot failure when using NFS on OMAP based evms To: Willem de Bruijn References: <570597EA.3040902@ti.com> CC: Sam Kumar , Willem de Bruijn , Eric Dumazet , , , Network Development , LKML , David Miller , , , , , , From: "Franklin S Cooper Jr." Message-ID: <57067089.4080406@ti.com> Date: Thu, 7 Apr 2016 09:36:57 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4256 Lines: 112 On 04/06/2016 09:22 PM, Willem de Bruijn wrote: > On Wed, Apr 6, 2016 at 7:12 PM, Franklin S Cooper Jr. wrote: >> Hi All, >> >> Currently linux-next is failing to boot via NFS on my AM335x GP evm, >> AM437x GP evm and Beagle X15. I bisected the problem down to the commit >> "udp: remove headers from UDP packets before queueing". >> >> I had to revert the following three commits to get things working again: >> >> e6afc8ace6dd5cef5e812f26c72579da8806f5ac >> udp: remove headers from UDP packets before queueing >> >> 627d2d6b550094d88f9e518e15967e7bf906ebbf >> udp: enable MSG_PEEK at non-zero offset >> >> b9bb53f3836f4eb2bdeb3447be11042bd29c2408 >> sock: convert sk_peek_offset functions to WRITE_ONCE >> > > Thanks for the report, and apologies for breaking your configuration. > I had missed that sunrpc can dequeue skbs from a udp receive > queue and makes assumptions about the layout of those packets. rxrpc > does the same. From what I can tell so far, those are the only two > protocols that do this. I have verified that the following fixes rxrpc for me > > --- a/net/rxrpc/ar-input.c > +++ b/net/rxrpc/ar-input.c > @@ -612,9 +612,9 @@ int rxrpc_extract_header(struct rxrpc_skb_priv > *sp, struct sk_buff *skb) > struct rxrpc_wire_header whdr; > > /* dig out the RxRPC connection details */ > - if (skb_copy_bits(skb, sizeof(struct udphdr), &whdr, sizeof(whdr)) < 0) > + if (skb_copy_bits(skb, 0, &whdr, sizeof(whdr)) < 0) > return -EBADMSG; > - if (!pskb_pull(skb, sizeof(struct udphdr) + sizeof(whdr))) > + if (!pskb_pull(skb, sizeof(whdr))) > BUG(); > > I have not yet been able to reproduce the sunrpc/nfs issue, but I > suspect that the following might fix it. I will try to create an NFS > setup. > > diff --git a/net/sunrpc/socklib.c b/net/sunrpc/socklib.c > index 2df87f7..8ab40ba 100644 > --- a/net/sunrpc/socklib.c > +++ b/net/sunrpc/socklib.c > @@ -155,7 +155,7 @@ int csum_partial_copy_to_xdr(struct xdr_buf *xdr, > struct sk_buff *skb) > struct xdr_skb_reader desc; > > desc.skb = skb; > - desc.offset = sizeof(struct udphdr); > + desc.offset = 0; > desc.count = skb->len - desc.offset; > > if (skb_csum_unnecessary(skb)) > diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c > index 1413cdc..71d6072 100644 > --- a/net/sunrpc/svcsock.c > +++ b/net/sunrpc/svcsock.c > @@ -617,7 +617,7 @@ static int svc_udp_recvfrom(struct svc_rqst *rqstp) > svsk->sk_sk->sk_stamp = skb->tstamp; > set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); /* there may be > more data... */ > > - len = skb->len - sizeof(struct udphdr); > + len = skb->len; > rqstp->rq_arg.len = len; > > rqstp->rq_prot = IPPROTO_UDP; > @@ -641,8 +641,7 @@ static int svc_udp_recvfrom(struct svc_rqst *rqstp) > skb_free_datagram_locked(svsk->sk_sk, skb); > } else { > /* we can use it in-place */ > - rqstp->rq_arg.head[0].iov_base = skb->data + > - sizeof(struct udphdr); > + rqstp->rq_arg.head[0].iov_base = skb->data; > rqstp->rq_arg.head[0].iov_len = len; > if (skb_checksum_complete(skb)) > goto out_free; > diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c > index 65e7595..c1fc7b2 100644 > --- a/net/sunrpc/xprtsock.c > +++ b/net/sunrpc/xprtsock.c > @@ -995,15 +995,14 @@ static void xs_udp_data_read_skb(struct rpc_xprt *xprt, > u32 _xid; > __be32 *xp; > > - repsize = skb->len - sizeof(struct udphdr); > + repsize = skb->len; > if (repsize < 4) { > dprintk("RPC: impossible RPC reply size %d!\n", repsize); > return; > } > > > > /* Copy the XID from the skb... */ > - xp = skb_header_pointer(skb, sizeof(struct udphdr), > - sizeof(_xid), &_xid); > + xp = skb_header_pointer(skb, 0, sizeof(_xid), &_xid); > if (xp == NULL) > return; > Thank you for your quick response. I verified with all of the above suggested changes that NFS works again on my 3 evms.