From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 42B62C433F5 for ; Thu, 16 Sep 2021 02:22:58 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E473261209 for ; Thu, 16 Sep 2021 02:22:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org E473261209 Authentication-Results: mail.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1631758976; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:list-id:list-help: list-unsubscribe:list-subscribe:list-post; bh=YzzeOgcAtR/MoPXMrrmXiBwEFcHa76snBkr52wTcaZY=; b=gTTEJtd56NOnAoTsEzLZH3zWerXh0pIQkz3QTMZ5le2/J4SZ6VbnnOCAB/xrsFsAqyeXLI /PROcBidbVBmNwMuQg8mMVMUtPPK6Gt+FwGqp9qqrhRY1du/bOXro4a/eOTVXVYJ8GE2hE OHamUqCvspbSNslfEgTVXwod9NtqbZg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-346-hWOXBGZ-MumlS5ScQ1OokQ-1; Wed, 15 Sep 2021 22:22:55 -0400 X-MC-Unique: hWOXBGZ-MumlS5ScQ1OokQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E11C61808304; Thu, 16 Sep 2021 02:22:50 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C278F10016FF; Thu, 16 Sep 2021 02:22:50 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id 8F53A4EA2F; Thu, 16 Sep 2021 02:22:50 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id 18G2MmCv028066 for ; Wed, 15 Sep 2021 22:22:48 -0400 Received: by smtp.corp.redhat.com (Postfix) id B264C100E107; Thu, 16 Sep 2021 02:22:48 +0000 (UTC) Received: from octiron.msp.redhat.com (unknown [10.15.80.209]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 85F8510016FF; Thu, 16 Sep 2021 02:22:43 +0000 (UTC) Received: from octiron.msp.redhat.com (localhost.localdomain [127.0.0.1]) by octiron.msp.redhat.com (8.14.9/8.14.9) with ESMTP id 18G2Mfp2007388; Wed, 15 Sep 2021 21:22:41 -0500 Received: (from bmarzins@localhost) by octiron.msp.redhat.com (8.14.9/8.14.9/Submit) id 18G2Mfe7007387; Wed, 15 Sep 2021 21:22:41 -0500 Date: Wed, 15 Sep 2021 21:22:40 -0500 From: Benjamin Marzinski To: mwilck@suse.com Message-ID: <20210916022240.GJ3087@octiron.msp.redhat.com> References: <20210910114120.13665-1-mwilck@suse.com> <20210910114120.13665-25-mwilck@suse.com> MIME-Version: 1.0 In-Reply-To: <20210910114120.13665-25-mwilck@suse.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-loop: dm-devel@redhat.com Cc: lixiaokeng@huawei.com, dm-devel@redhat.com, Chongyun Wu Subject: Re: [dm-devel] [PATCH 24/35] multipathd: uxlsnr: use main poll loop for receiving X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dm-devel-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Disposition: inline Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Fri, Sep 10, 2021 at 01:41:09PM +0200, mwilck@suse.com wrote: > From: Martin Wilck > > As a first step towards our state machine, avoid the call to > read_all() via recv_packet_from_client(). handle_client() is now > invoked twice for the same connection. The first time it reads > the command length, and later on it reads the command itself > piece-wise, as sent by the client. This will be just a single > read in most cases, but not always. > Reviewed-by: Benjamin Marzinski > Signed-off-by: Martin Wilck > --- > multipathd/uxlsnr.c | 90 +++++++++++++++++++++++++++++++++++++-------- > 1 file changed, 75 insertions(+), 15 deletions(-) > > diff --git a/multipathd/uxlsnr.c b/multipathd/uxlsnr.c > index 2fb23c8..eff4f7b 100644 > --- a/multipathd/uxlsnr.c > +++ b/multipathd/uxlsnr.c > @@ -292,6 +292,8 @@ static void handle_inotify(int fd, struct watch_descriptors *wds) > condlog(1, "Multipath configuration updated.\nReload multipathd for changes to take effect"); > } > > +static const struct timespec ts_zero = { .tv_sec = 0, }; > + > static int parse_cmd (char *cmd, char **reply, int *len, void *data, > int timeout) > { > @@ -394,23 +396,78 @@ static int uxsock_trigger(char *str, char **reply, int *len, > return r; > } > > +static void set_client_state(struct client *c, int state) > +{ > + switch(state) > + { > + case CLT_RECV: > + reset_strbuf(&c->reply); > + memset(c->cmd, '\0', sizeof(c->cmd)); > + c->expires = ts_zero; > + /* fallthrough */ > + case CLT_SEND: > + /* reuse these fields for next data transfer */ > + c->len = c->cmd_len = 0; > + break; > + default: > + break; > + } > + c->state = state; > +} > + > static void handle_client(struct client *c, void *trigger_data) > { > int rlen; > - char *inbuf, *reply; > + char *reply; > + ssize_t n; > > - if (recv_packet_from_client(c->fd, &inbuf, uxsock_timeout) != 0) { > - dead_client(c); > - return; > + switch (c->state) { > + case CLT_RECV: > + if (c->cmd_len == 0) { > + /* > + * We got POLLIN; assume that at least the length can > + * be read immediately. > + */ > + get_monotonic_time(&c->expires); > + c->expires.tv_sec += uxsock_timeout / 1000; > + c->expires.tv_nsec += (uxsock_timeout % 1000) * 1000000; > + normalize_timespec(&c->expires); > + n = mpath_recv_reply_len(c->fd, 0); > + if (n == -1) { > + condlog(1, "%s: cli[%d]: failed to receive reply len", > + __func__, c->fd); > + c->error = -ECONNRESET; > + } else if (n > _MAX_CMD_LEN) { > + condlog(1, "%s: cli[%d]: overlong command (%zd bytes)", > + __func__, c->fd, n); > + c->error = -ECONNRESET; > + } else { > + c->cmd_len = n; > + condlog(4, "%s: cli[%d]: connected", __func__, c->fd); > + } > + /* poll for data */ > + return; > + } else if (c->len < c->cmd_len) { > + n = recv(c->fd, c->cmd + c->len, c->cmd_len - c->len, 0); > + if (n <= 0 && errno != EINTR && errno != EAGAIN) { > + condlog(1, "%s: cli[%d]: error in recv: %m", > + __func__, c->fd); > + c->error = -ECONNRESET; > + return; > + } > + c->len += n; > + if (c->len < c->cmd_len) > + /* continue polling */ > + return; > + set_client_state(c, CLT_PARSE); > + } > + break; > + default: > + break; > } > > - if (!inbuf) { > - condlog(4, "recv_packet_from_client get null request"); > - return; > - } > - > - condlog(4, "cli[%d]: Got request [%s]", c->fd, inbuf); > - uxsock_trigger(inbuf, &reply, &rlen, > + condlog(4, "cli[%d]: Got request [%s]", c->fd, c->cmd); > + uxsock_trigger(c->cmd, &reply, &rlen, > _socket_client_is_root(c->fd), > trigger_data); > > @@ -418,11 +475,12 @@ static void handle_client(struct client *c, void *trigger_data) > if (send_packet(c->fd, reply) != 0) > dead_client(c); > else > - condlog(4, "cli[%d]: Reply [%d bytes]", c->fd, rlen); > - FREE(reply); > - reply = NULL; > + condlog(4, "cli[%d]: Reply [%zu bytes]", c->fd, > + get_strbuf_len(&c->reply) + 1); > + reset_strbuf(&c->reply); > } > - FREE(inbuf); > + > + set_client_state(c, CLT_RECV); > } > > /* > @@ -553,6 +611,8 @@ void *uxsock_listen(long ux_sock, void *trigger_data) > continue; > } > handle_client(c, trigger_data); > + if (c->error == -ECONNRESET) > + dead_client(c); > } > } > /* see if we got a non-fatal signal */ > -- > 2.33.0 -- dm-devel mailing list dm-devel@redhat.com https://listman.redhat.com/mailman/listinfo/dm-devel