Patchwork [net-next,v3,3/6] net_sched: mirred: remove action when the target device is gone

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Submitter WANG Cong
Date Dec. 13, 2013, 5:47 a.m.
Message ID <1386913673-8210-4-git-send-email-xiyou.wangcong@gmail.com>
Download mbox | patch
Permalink /patch/300891/
State Superseded
Delegated to: David Miller
Headers show

Comments

WANG Cong - Dec. 13, 2013, 5:47 a.m.
When the target device is removed, the mirred action is
still there but with the dev pointer setting to NULL.
This makes the output from 'tc filter' ugly. There is no
reason to keep it.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
---
 include/net/tc_act/tc_mirred.h |  4 +++-
 net/sched/act_mirred.c         | 15 +++++++--------
 2 files changed, 10 insertions(+), 9 deletions(-)
Jamal Hadi Salim - Dec. 13, 2013, 12:07 p.m.
On 12/13/13 00:47, Cong Wang wrote:
> When the target device is removed, the mirred action is
> still there but with the dev pointer setting to NULL.
> This makes the output from 'tc filter' ugly. There is no
> reason to keep it.
>
> Cc: Jamal Hadi Salim <jhs@mojatatu.com>
> Cc: David S. Miller <davem@davemloft.net>
> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
> ---
>   include/net/tc_act/tc_mirred.h |  4 +++-
>   net/sched/act_mirred.c         | 15 +++++++--------
>   2 files changed, 10 insertions(+), 9 deletions(-)
>
> diff --git a/include/net/tc_act/tc_mirred.h b/include/net/tc_act/tc_mirred.h
> index cfe2943..2026cf6 100644
> --- a/include/net/tc_act/tc_mirred.h
> +++ b/include/net/tc_act/tc_mirred.h
> @@ -7,9 +7,11 @@ struct tcf_mirred {
>   	struct tcf_common	common;
>   	int			tcfm_eaction;
>   	int			tcfm_ifindex;
> -	int			tcfm_ok_push;
> +	unsigned int		tcfm_ok_push:1;
> +	unsigned int		tcfm_bind:1;

What has the above cleverness got to do with anything you intended?

cheers,
jamal
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David Laight - Dec. 13, 2013, 12:12 p.m.
> From: Jamal Hadi Salim
> Sent: 13 December 2013 12:08
...
> > -	int			tcfm_ok_push;
> > +	unsigned int		tcfm_ok_push:1;
> > +	unsigned int		tcfm_bind:1;
> 
> What has the above cleverness got to do with anything you intended?

Not even 'cleverness'.
Using byte-sized fields is enough to stop the structure growing.
Bit fields are usually not a good idea at all.

	David



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WANG Cong - Dec. 13, 2013, 6:52 p.m.
On Fri, Dec 13, 2013 at 4:12 AM, David Laight <David.Laight@aculab.com> wrote:
>> From: Jamal Hadi Salim
>> Sent: 13 December 2013 12:08
> ...
>> > -   int                     tcfm_ok_push;
>> > +   unsigned int            tcfm_ok_push:1;
>> > +   unsigned int            tcfm_bind:1;
>>
>> What has the above cleverness got to do with anything you intended?
>
> Not even 'cleverness'.
> Using byte-sized fields is enough to stop the structure growing.
> Bit fields are usually not a good idea at all.
>

They are both boolean, I think it is a waste to use 'int' for both of them.
I am not a fan of bit fields though.
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Patch

diff --git a/include/net/tc_act/tc_mirred.h b/include/net/tc_act/tc_mirred.h
index cfe2943..2026cf6 100644
--- a/include/net/tc_act/tc_mirred.h
+++ b/include/net/tc_act/tc_mirred.h
@@ -7,9 +7,11 @@  struct tcf_mirred {
 	struct tcf_common	common;
 	int			tcfm_eaction;
 	int			tcfm_ifindex;
-	int			tcfm_ok_push;
+	unsigned int		tcfm_ok_push:1;
+	unsigned int		tcfm_bind:1;
 	struct net_device	*tcfm_dev;
 	struct list_head	tcfm_list;
+	struct tc_action	*tcfm_act;
 };
 #define to_mirred(pc) \
 	container_of(pc, struct tcf_mirred, common)
diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c
index 2523781..c26bfe5 100644
--- a/net/sched/act_mirred.c
+++ b/net/sched/act_mirred.c
@@ -136,6 +136,8 @@  static int tcf_mirred_init(struct net *net, struct nlattr *nla,
 		dev_hold(dev);
 		m->tcfm_dev = dev;
 		m->tcfm_ok_push = ok_push;
+		m->tcfm_bind = bind;
+		m->tcfm_act = a;
 	}
 	spin_unlock_bh(&m->tcf_lock);
 	if (ret == ACT_P_CREATED) {
@@ -169,10 +171,6 @@  static int tcf_mirred(struct sk_buff *skb, const struct tc_action *a,
 	bstats_update(&m->tcf_bstats, skb);
 
 	dev = m->tcfm_dev;
-	if (!dev) {
-		printk_once(KERN_NOTICE "tc mirred: target device is gone\n");
-		goto out;
-	}
 
 	if (!(dev->flags & IFF_UP)) {
 		net_notice_ratelimited("tc mirred to Houston: device %s is down\n",
@@ -244,13 +242,14 @@  static int mirred_device_event(struct notifier_block *unused,
 			       unsigned long event, void *ptr)
 {
 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
-	struct tcf_mirred *m;
+	struct tcf_mirred *m, *tmp;
 
 	if (event == NETDEV_UNREGISTER)
-		list_for_each_entry(m, &mirred_list, tcfm_list) {
+		list_for_each_entry_safe(m, tmp, &mirred_list, tcfm_list) {
 			if (m->tcfm_dev == dev) {
-				dev_put(dev);
-				m->tcfm_dev = NULL;
+				list_del(&m->tcfm_act->list);
+				tcf_mirred_cleanup(m->tcfm_act, m->tcfm_bind);
+				kfree(m->tcfm_act);
 			}
 		}