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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 107EAC3F6B0 for ; Fri, 5 Aug 2022 18:27:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241283AbiHES1b (ORCPT ); Fri, 5 Aug 2022 14:27:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60574 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241225AbiHES12 (ORCPT ); Fri, 5 Aug 2022 14:27:28 -0400 Received: from mail-pg1-x52c.google.com (mail-pg1-x52c.google.com [IPv6:2607:f8b0:4864:20::52c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BE2A07A533; Fri, 5 Aug 2022 11:27:26 -0700 (PDT) Received: by mail-pg1-x52c.google.com with SMTP id f11so3318418pgj.7; Fri, 05 Aug 2022 11:27:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=AioU5oUE5g4jF1wbScY3S1UHHdfeyCyY6/YrQaOYSsg=; b=ad35ukFWKMSqyuH7imBf6ZVcSHjPYpipHSBVJvYPCSL2DaXaRxxsZajWTtT9lKuqSb WTJlEPQeqT5G+kJmd1LZd/ESmC2433vWBX1JWTE8IBNyrZ9p2NDD6MTROpXUy4sCYqDU hy0GcaqZ2rPu4ExV/gZ+aD80DGJTwBi/I2i83cCTBX2dI3KOY8s/ELUSM9I3+YvnTAzJ Rc6VdAd5jz/FVLGpp/9X+cYAdmoSeRtc/kdThgURHPT0yM2hhJW4FPYmXA+X/mz5W3Nv dWE99ix2QpZJ57CeD7fDueL95INE835zvEAXl85gUDQLp5L9Yx/XIiegsUk9dIA+KKx9 NTCw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=AioU5oUE5g4jF1wbScY3S1UHHdfeyCyY6/YrQaOYSsg=; b=4Oei6XExi5bgZwzG5ul/enF8iLKX46abOLSwwt622QivVBSW1w6uhJHZP1NbmTNmv6 /Y5qhIfKJnfGIcxe2msoROhlzeBhv0XsZvIwMj09VycVNwafvvJUgash7Y/XHh7brEOP KhFSYZHODvOo67r3yTkRan0H8tuaKsnE3NnuT/coQOrgo/3FEMNeT5/l9fWXDRpcnytI oVyk5UeVtPMQpRP91Uobn0NUQ7oKYZfNLc2TVzGuBnvyHVKMjcAgETptpZLp01e+tK8P 71h3KtD0mphCHV3oWAnIovM74663gFlJlnerB4IY82VyJK0ytdA7ySjmyeWmYy8V73hf znFw== X-Gm-Message-State: ACgBeo1mmruD0+gxzlfvvW3vZvKggwZGyrq7bM1n7NPlKNPHmVr3w5yE F1Zpy3CVAXtpQSdpXd09QA== X-Google-Smtp-Source: AA6agR7LiU0xyCJ09OZa/6LwgqA2y3Bwj+Jwac4aAi+Crn5xO9X0Q3+O42fBF+fuWGndnpSjbIGf8w== X-Received: by 2002:aa7:9390:0:b0:52d:8816:a906 with SMTP id t16-20020aa79390000000b0052d8816a906mr7910716pfe.63.1659724046005; Fri, 05 Aug 2022 11:27:26 -0700 (PDT) Received: from bytedance ([139.177.225.229]) by smtp.gmail.com with ESMTPSA id ik30-20020a170902ab1e00b0016c1a1c1405sm3244850plb.222.2022.08.05.11.27.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 05 Aug 2022 11:27:25 -0700 (PDT) Date: Fri, 5 Aug 2022 11:27:15 -0700 From: Peilin Ye To: Stefano Garzarella Cc: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Peilin Ye , virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH RFC net-next] vsock: Reschedule connect_work for O_NONBLOCK connect() requests Message-ID: <20220805182715.GA17335@bytedance> References: <20220804020925.32167-1-yepeilin.cs@gmail.com> <20220804065923.66bor7cyxwk2bwsf@sgarzare-redhat> <20220804234447.GA2294@bytedance> <20220805124239.iy5lkeytqwjyvn7g@sgarzare-redhat> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220805124239.iy5lkeytqwjyvn7g@sgarzare-redhat> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 05, 2022 at 02:42:39PM +0200, Stefano Garzarella wrote: > On Thu, Aug 04, 2022 at 04:44:47PM -0700, Peilin Ye wrote: > > 1. I think the root cause of this memleak is, we keep @connect_work > > pending, even after the 2nd, blocking request times out (or gets > > interrupted) and sets sock->state back to SS_UNCONNECTED. > > > > @connect_work is effectively no-op when sk->sk_state is > > TCP_CLOS{E,ING} anyway, so why not we just cancel @connect_work when > > blocking requests time out or get interrupted? Something like: > > > > diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c > > index f04abf662ec6..62628af84164 100644 > > --- a/net/vmw_vsock/af_vsock.c > > +++ b/net/vmw_vsock/af_vsock.c > > @@ -1402,6 +1402,9 @@ static int vsock_connect(struct socket *sock, struct sockaddr *addr, > > lock_sock(sk); > > > > if (signal_pending(current)) { > > + if (cancel_delayed_work(&vsk->connect_work)) > > + sock_put(sk); > > + > > err = sock_intr_errno(timeout); > > sk->sk_state = sk->sk_state == TCP_ESTABLISHED ? TCP_CLOSING : TCP_CLOSE; > > sock->state = SS_UNCONNECTED; > > @@ -1409,6 +1412,9 @@ static int vsock_connect(struct socket *sock, struct sockaddr *addr, > > vsock_remove_connected(vsk); > > goto out_wait; > > } else if (timeout == 0) { > > + if (cancel_delayed_work(&vsk->connect_work)) > > + sock_put(sk); > > + > > err = -ETIMEDOUT; > > sk->sk_state = TCP_CLOSE; > > sock->state = SS_UNCONNECTED; > > > > Then no need to worry about rescheduling @connect_work, and the state > > machine becomes more accurate. What do you think? I will ask syzbot > > to test this. > > It could work, but should we set `sk->sk_err` and call sk_error_report() to > wake up thread waiting on poll()? > > Maybe the previous version is simpler. Right, I forgot about sk_error_report(). Let us use the simpler version then. > > 2. About your suggestion of setting sock->state = SS_UNCONNECTED in > > vsock_connect_timeout(), I think it makes sense. Are you going to > > send a net-next patch for this? > > If you have time, feel free to send it. > > Since it is a fix, I believe you can use the "net" tree. (Also for this > patch). > > Remember to put the "Fixes" tag that should be the same. Sure, I will send them this week. Thanks! Peilin Ye