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Date: Wed, 28 Feb 2024 13:30:42 +0100
From: Jiri Pirko <jiri@resnulli.us>
To: Lena Wang =?utf-8?B?KOeOi+WonCk=?= <Lena.Wang@mediatek.com>
Cc: "davem@davemloft.net" <davem@davemloft.net>,
	"kuba@kernel.org" <kuba@kernel.org>,
	"pabeni@redhat.com" <pabeni@redhat.com>,
	"dsahern@kernel.org" <dsahern@kernel.org>,
	"edumazet@google.com" <edumazet@google.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	Shiming Cheng =?utf-8?B?KOaIkOivl+aYjik=?= <Shiming.Cheng@mediatek.com>
Subject: Re: [PATCH net v2] Net:cache didn't flush when ipv6 rule changed
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[PATCH net v2] Net:cache didn't flush when ipv6 rule changed

Please make sure your patch subject is aligned with the rest:
$ git log --no-merges --pretty=format:"%s" net/ipv6/fib6_rules.c | head -n30
fib: remove unnecessary input parameters in fib_default_rule_add
ipv6: change fib6_rules_net_exit() to batch mode
ipv6: Define dscp_t and stop taking ECN bits into account in fib6-rules
fib: rules: remove duplicated nla policies
ipv6: fix memory leak in fib6_rule_suppress
ipv6: fib6: remove redundant initialization of variable err
fib: use indirect call wrappers in the most common fib_rules_ops
ipv6: fib6: avoid indirect calls from fib6_rule_lookup
net: fib_notifier: propagate extack down to the notifier block callback
ipv6: do not free rt if FIB_LOOKUP_NOREF is set on suppress rule
ipv6: honor RT6_LOOKUP_F_DST_NOREF in rule lookup logic
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 372
ipv6: Use result arg in fib_lookup_arg consistently
ipv6: fib6_rule_action_alt needs to return -EAGAIN
ipv6: Pass fib6_result to fib lookups
net/ipv6: Add fib6_lookup
net/ipv6: Refactor fib6_rule_action
net: fib_rules: add extack support
net: Drop pernet_operations::async
net/ipv6: Pass skb to route lookup
ipv6: route: dissect flow in input path if fib rules need it
ipv6: fib6_rules: support for match on sport, dport and ip proto
net: Convert fib6_rules_net_ops
net: ipv6: avoid overhead when no custom FIB rules are installed
ipv6: fib_rules: Dump rules during registration to FIB chain
ipv6: fib_rules: Check if rule is a default rule
ipv6: Do not leak throw route references
net: flow: Add l3mdev flow update
net: Add l3mdev rule
ipv6: fix the incorrect return value of throw route

Use imperative mood as other subjects do, tell the codebase what do do.


Wed, Feb 28, 2024 at 09:24:55AM CET, Lena.Wang@mediatek.com wrote:
>From bf53859b379a653eec8a14fbb3f29286f9f888fb Mon Sep 17 00:00:00 2001
>From: shiming cheng <shiming.cheng@mediatek.com>

Names start with capital letters.


>Date: Mon, 26 Feb 2024 20:17:58 +0800
>Subject: [PATCH net v2] Net:cache didn't flush when ipv6 rule changed

I don't understand why you put these "headers" here. Only one "from" is
enough in this case (you are submitting the patch in stead of another
person).

If you are not, I suggest to use git-send-email for submissions.


>
>When changed from old rule&route configure to new one as below,

"as below" where?

>ipv6 cache dst_entry did not change to new route table as no
>cache flush callback function, then forward to wrong out interface.

I don't understand this sentence :/


>When fib6_check dst_entry, the fib6_node version[fn_sernm] is
>always the same with socket dst_cookie, old cache dst_entry is
>always used and no chance to update.

Sorry, this is too cryptic for me to understand :/


>
>So we need to update fib6_node version when rule changed and
>flush cache to avoid dispatching a wrong interface.

Be imperative in the patch description too, tell the codebase what do do.

https://www.kernel.org/doc/html/v6.6/process/submitting-patches.html#describe-your-changes


>
>Signed-off-by: shiming cheng <shiming.cheng@mediatek.com>

Names start with capital letters.

Also, when you submit the patch, your signed-off-by tag should be here
as well.


>---
>v2: 
>    1. Add the fix tag.

And there, there is none...


pw-bot: cr


>    2. Changes according to David Ahern's suggestions, modify flush
>functions same way as ipv4 flush cache and use tabs to aligh with
>existing code.
>---
>---
> net/ipv6/fib6_rules.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
>diff --git a/net/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c
>index 7523c4baef35..52c04f0ac498 100644
>--- a/net/ipv6/fib6_rules.c
>+++ b/net/ipv6/fib6_rules.c
>@@ -449,6 +449,11 @@ static size_t fib6_rule_nlmsg_payload(struct
>fib_rule *rule)
> 	       + nla_total_size(16); /* src */
> }
> 
>+static void fib6_rule_flush_cache(struct fib_rules_ops *ops)
>+{
>+	rt_genid_bump_ipv6(ops->fro_net);
>+}
>+
> static const struct fib_rules_ops __net_initconst
>fib6_rules_ops_template = {
> 	.family			= AF_INET6,
> 	.rule_size		= sizeof(struct fib6_rule),
>@@ -461,6 +466,7 @@ static const struct fib_rules_ops __net_initconst
>fib6_rules_ops_template = {
> 	.compare		= fib6_rule_compare,
> 	.fill			= fib6_rule_fill,
> 	.nlmsg_payload		= fib6_rule_nlmsg_payload,
>+	.flush_cache		= fib6_rule_flush_cache,
> 	.nlgroup		= RTNLGRP_IPV6_RULE,
> 	.owner			= THIS_MODULE,
> 	.fro_net		= &init_net,
>-- 
>2.18.0
>