From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Ricardo Leitner Subject: Re: [PATCHv2 net] sctp: change to save MSG_MORE flag into assoc Date: Mon, 27 Mar 2017 19:43:55 -0300 Message-ID: <20170327224355.GK23553@localhost.localdomain> References: <6faab86dbae351f6ae3994c77dbaf56ac2d98ecf.1490545275.git.lucien.xin@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: network dev , linux-sctp@vger.kernel.org, davem@davemloft.net, Neil Horman , David Laight To: Xin Long Return-path: Received: from mx1.redhat.com ([209.132.183.28]:44508 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752887AbdC0WoJ (ORCPT ); Mon, 27 Mar 2017 18:44:09 -0400 Content-Disposition: inline In-Reply-To: <6faab86dbae351f6ae3994c77dbaf56ac2d98ecf.1490545275.git.lucien.xin@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, Mar 27, 2017 at 12:21:15AM +0800, Xin Long wrote: > David Laight noticed the support for MSG_MORE with datamsg->force_delay > didn't really work as we expected, as the first msg with MSG_MORE set > would always block the following chunks' dequeuing. > > This Patch is to rewrite it by saving the MSG_MORE flag into assoc as > David Laight suggested. > > asoc->force_delay is used to save MSG_MORE flag before a msg is sent. > All chunks in queue would not be sent out if asoc->force_delay is set > by the msg with MSG_MORE flag, until a new msg without MSG_MORE flag > clears asoc->force_delay. > > Note that this change would not affect the flush is generated by other > triggers, like asoc->state != ESTABLISHED, queue size > pmtu etc. > > v1->v2: > Not clear asoc->force_delay after sending the msg with MSG_MORE flag. > > Fixes: 4ea0c32f5f42 ("sctp: add support for MSG_MORE") > Signed-off-by: Xin Long > --- > include/net/sctp/structs.h | 2 +- > net/sctp/output.c | 2 +- > net/sctp/socket.c | 2 +- > 3 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h > index 592dece..8caa5ee 100644 > --- a/include/net/sctp/structs.h > +++ b/include/net/sctp/structs.h > @@ -499,7 +499,6 @@ struct sctp_datamsg { > /* Did the messenge fail to send? */ > int send_error; > u8 send_failed:1, > - force_delay:1, > can_delay; /* should this message be Nagle delayed */ > }; > > @@ -1878,6 +1877,7 @@ struct sctp_association { > > __u8 need_ecne:1, /* Need to send an ECNE Chunk? */ > temp:1, /* Is it a temporary association? */ > + force_delay:1, > prsctp_enable:1, > reconf_enable:1; > > diff --git a/net/sctp/output.c b/net/sctp/output.c > index 1224421..73fd178 100644 > --- a/net/sctp/output.c > +++ b/net/sctp/output.c > @@ -704,7 +704,7 @@ static sctp_xmit_t sctp_packet_can_append_data(struct sctp_packet *packet, > */ > > if ((sctp_sk(asoc->base.sk)->nodelay || inflight == 0) && > - !chunk->msg->force_delay) > + !asoc->force_delay) How is this going to not block the flush on asoc->state != ESTABLISHED? AFAICT b7018d0b6300 ("sctp: flush out queue once assoc state falls into SHUTDOWN_PENDING") need to clear asoc->force_delay too. Case I have in mind is the same old one: - app send a msg with MSG_MORE - close the asoc, without sending the final msg > /* Nothing unacked */ > return SCTP_XMIT_OK; > > diff --git a/net/sctp/socket.c b/net/sctp/socket.c > index 0f378ea..baa269a 100644 > --- a/net/sctp/socket.c > +++ b/net/sctp/socket.c > @@ -1965,7 +1965,7 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len) > err = PTR_ERR(datamsg); > goto out_free; > } > - datamsg->force_delay = !!(msg->msg_flags & MSG_MORE); > + asoc->force_delay = !!(msg->msg_flags & MSG_MORE); > > /* Now send the (possibly) fragmented message. */ > list_for_each_entry(chunk, &datamsg->chunks, frag_list) { > -- > 2.1.0 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-sctp" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >