From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 39EF43793DD for ; Thu, 23 Apr 2026 10:13:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776939206; cv=none; b=tuj+UXI4F2J0QEoPpVLyakmqIE8R2i1DcdysugoK5pJPFqwl/qmyrhXMLLP6ks/FkVea3EQlr+J5NKkdQn+hhHaHFDei3y1wpK9BmW5qSqst1h418ZndONgAxBExaPSLUOr6efPjw4di3X5QfhN6EoKSSyXawftGnZEvzSoke+0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776939206; c=relaxed/simple; bh=2REbWSVv6SJOy7FnA2tVcEQgkIZf2TRIcOEhVdMfb0I=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=MIEDfMAAbsnK3TiRsuZcgRT5c0uBJqz5mdhD+L4vI12n3ATof5SGL8DMpxuLtqIWSL5aycq16b22XE2o16YgUV27dLBkysaIJNf3yE0CrKSgoGwiRxKJ0ksi8OJKic3G9iG7nusDziqUlLU5oAAruvL20ByQdFRPKH4KeTXiAcU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=O+cAcZn0; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=N3EvWZNi; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="O+cAcZn0"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="N3EvWZNi" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1776939203; h=from:from: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; bh=QkTAY0cWRY7AHIF+qIX/Mtw1Z0EQWzt9k3+TnQSWKLw=; b=O+cAcZn0H13VYQde+lko4VpeniIxsUzGdHV8afE3K6fQKejs6646EUjWnhUcpaoeVhKIkY 8WmvwtX7V6TLJJbNhv80UzokENBAATapANo24RI9P0k8pxFAcfu9+BlgKjiUbJL6Sgqcs0 rwi7ozcRO7Osm2EvFHaeILWtO6FBjaI= Received: from mail-wm1-f69.google.com (mail-wm1-f69.google.com [209.85.128.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-141-9UguDlvMP0SjeurV_9poLQ-1; Thu, 23 Apr 2026 06:13:22 -0400 X-MC-Unique: 9UguDlvMP0SjeurV_9poLQ-1 X-Mimecast-MFC-AGG-ID: 9UguDlvMP0SjeurV_9poLQ_1776939201 Received: by mail-wm1-f69.google.com with SMTP id 5b1f17b1804b1-48a5adc12ffso12767635e9.0 for ; Thu, 23 Apr 2026 03:13:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1776939201; x=1777544001; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=QkTAY0cWRY7AHIF+qIX/Mtw1Z0EQWzt9k3+TnQSWKLw=; b=N3EvWZNiuM+BbQdXXECLX+hk8dXQT0BGkYWG92YTbk1O0xeaFCuqqQaSDWFcFDWPIz BWvAKH4RRdEb+0b4nwCbo83khtAYDFph0CJE+Zena7o6BxhoW5AlObHt7WY8iAqc/UDO FG8kSC+dOiUQXxsPxxetq/P2FkFWrYYDfdXW+poazopJwCACrQoBjQ9jklLjwtkO7OcT rf8eIxgjkd1Pmeh+Wii1WVsRT9KmgXGfqSMNemuH8I2IV0MXvSWag47uCH4wEdmujcB8 OTxk7+Bq0KrUJpf0hePHqzdE4GkKZibItq9HRE6Cigudh9XM0vo1cc0j9ROJBEgeEIMz sVQw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1776939201; x=1777544001; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=QkTAY0cWRY7AHIF+qIX/Mtw1Z0EQWzt9k3+TnQSWKLw=; b=CW3kpVS1nuZ5vifqCy6W0roH6ccvWczN93Vt9JX9rzqARb/eKzibyohY+zvlnt31XC R9+zZR9ijsufLk6wpRc2nBK1i2rigZcfn/bp01Nb7orsZIb4drs/AtvFQTHnY5ld58QA z/dk6k8tVenlLLPKe7iCHy2vcdcldtJ/uPLXtoF3Svw09H/DZYOlOjkZ3nP+DbYPhw3O 1KH9cu1G6Giu2zwHNa4yt9NIMMUTwio147VLbowvB+/36qMB5MYuDzklSX8LKGlWr81t 1rDRc1w2uwqpwZiL7XY47CAqUcErFTbo/FrO7Ic+/MrAWs5uLLhI3P85i/7IMPaA8bzz TGXQ== X-Gm-Message-State: AOJu0Yw7CNZ6sgwHUmSDXYANLEwGhoxUEcsIjUDrd2j5OVyMzhbc1mDA YujQpd5Ewk6A2ClIoD3RuGOfTfr4vYD0OXtJxczzwYY8FzUUXXXzZrulR7QAuUJQsW460UiaYp7 NoMl/hhgv+fFT2iKvnwJvXc1uUTCmIgIxi6kmaUjYMxmtnT3eXShBEYetVA== X-Gm-Gg: AeBDietAQ/3QkUtpCJdkNq2A/fI2QMg/WqjiRb/rqGxjNXvfJRqEkNrTGTCUr3uvHxd wQPwymh3qCvgfl+caDLhaMgvD87rP8vI8da0JqO3oedo+dZuUL6sYkRuN1w7znnqTwY3TT3To67 r3WZsx+MWs+YYU/84n/BoQAhAFUgK5JdWQ/+MCyWry3GUdA/1gXPYnKYcjv8kU+jK1GjUO2ru4l ZIV8L6S9byU5csC9OhLyE4Zp0Ju9SKy6Nw0ZOsjo6gCoBFS2Xhfhy0BVx4BEcGEYzEDmMwEKGG4 k+LVfrZsqezuJmymz/fVmVrcWslPaOusgQouJWg28v9DNPppWVx4p2zDZasQLA00SJmzF4heibD O//aCBXw0paRYrAsdOnUmGdEUMVa+oWH5WeP0LO37rrdKRyXPrglXU9XgIgjXyOM7tqU= X-Received: by 2002:a05:600c:6209:b0:48a:592c:e63d with SMTP id 5b1f17b1804b1-48a592ce89emr113247815e9.14.1776939200869; Thu, 23 Apr 2026 03:13:20 -0700 (PDT) X-Received: by 2002:a05:600c:6209:b0:48a:592c:e63d with SMTP id 5b1f17b1804b1-48a592ce89emr113247435e9.14.1776939200401; Thu, 23 Apr 2026 03:13:20 -0700 (PDT) Received: from [192.168.88.32] ([150.228.93.216]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-488fc10777csm582390305e9.8.2026.04.23.03.13.19 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 23 Apr 2026 03:13:19 -0700 (PDT) Message-ID: <8bae5082-b086-4c22-a19a-3a3c20c827a9@redhat.com> Date: Thu, 23 Apr 2026 12:13:18 +0200 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net v2 2/2] 8021q: delete cleared egress QoS mappings To: Simon Horman , Ren Wei Cc: netdev@vger.kernel.org, edumazet@google.com, andrew+netdev@lunn.ch, davem@davemloft.net, kuba@kernel.org, kees@kernel.org, yuantan098@gmail.com, ylong030@ucr.edu, yifanwucs@gmail.com, tomapufckgml@gmail.com, bird@lzu.edu.cn References: <9136768189f8c6d3f824f476c62d2fa1111688e8.1776647968.git.yuantan098@gmail.com> <20260422162041.GO651125@horms.kernel.org> Content-Language: en-US From: Paolo Abeni In-Reply-To: <20260422162041.GO651125@horms.kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 4/22/26 6:20 PM, Simon Horman wrote: > On Mon, Apr 20, 2026 at 11:18:46AM +0800, Ren Wei wrote: >> From: Longxuan Yu >> >> vlan_dev_set_egress_priority() currently keeps cleared egress >> priority mappings in the hash as tombstones. Repeated set/clear cycles >> with distinct skb priorities therefore accumulate mapping nodes until >> device teardown and leak memory. >> >> Delete mappings when vlan_prio is cleared instead of keeping tombstones. >> Now that the egress mapping lists are RCU protected, the node can be >> unlinked safely and freed after a grace period. >> >> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") >> Cc: stable@kernel.org >> Reported-by: Yifan Wu >> Reported-by: Juefei Pu >> Reported-by: Xin Liu >> Co-developed-by: Yuan Tan >> Signed-off-by: Yuan Tan >> Signed-off-by: Longxuan Yu >> Signed-off-by: Ren Wei >> --- >> net/8021q/vlan_dev.c | 20 ++++++++++++++------ >> net/8021q/vlan_netlink.c | 4 ---- >> 2 files changed, 14 insertions(+), 10 deletions(-) >> >> diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c >> index a5340932b657..7aa3af8b10ea 100644 >> --- a/net/8021q/vlan_dev.c >> +++ b/net/8021q/vlan_dev.c >> @@ -172,26 +172,34 @@ int vlan_dev_set_egress_priority(const struct net_device *dev, >> u32 skb_prio, u16 vlan_prio) >> { >> struct vlan_dev_priv *vlan = vlan_dev_priv(dev); >> + struct vlan_priority_tci_mapping __rcu **mpp; >> struct vlan_priority_tci_mapping *mp; >> struct vlan_priority_tci_mapping *np; >> u32 bucket = skb_prio & 0xF; >> u32 vlan_qos = (vlan_prio << VLAN_PRIO_SHIFT) & VLAN_PRIO_MASK; >> >> /* See if a priority mapping exists.. */ >> - mp = rtnl_dereference(vlan->egress_priority_map[bucket]); >> + mpp = &vlan->egress_priority_map[bucket]; >> + mp = rtnl_dereference(*mpp); >> while (mp) { >> if (mp->priority == skb_prio) { >> - if (mp->vlan_qos && !vlan_qos) >> + if (!vlan_qos) { >> + rcu_assign_pointer(*mpp, rtnl_dereference(mp->next)); >> vlan->nr_egress_mappings--; >> - else if (!mp->vlan_qos && vlan_qos) >> - vlan->nr_egress_mappings++; >> - WRITE_ONCE(mp->vlan_qos, vlan_qos); >> + kfree_rcu(mp, rcu); >> + } else { >> + WRITE_ONCE(mp->vlan_qos, vlan_qos); >> + } >> return 0; >> } >> - mp = rtnl_dereference(mp->next); >> + mpp = &mp->next; >> + mp = rtnl_dereference(*mpp); >> } > > Hi Ren, > > Thanks for splitting up the patchset, it is very helpful to me. > > It seems to me that the mpp/mp construct used is a bit complex and > stems from the use of a hand-rolled list centred the next field of > struct vlan_priority_tci_mapping. > > I wonder if things can be simplified by moving to use a standardised > list construct, such as an hlist. And the helpers available for using it. I agree hlist_rcu usage would simplify the code above, but I fear it will make this already relatively big change even bigger, as several list traversing places will need to be updated accordingly. I think conversion to hlist_rcu could/should be a net-next follow-up. Thanks, Paolo