From: Veaceslav Falico <vfalico@redhat•com>
To: Ding Tianhong <dingtianhong@huawei•com>
Cc: netdev@vger•kernel.org, Jay Vosburgh <fubar@us•ibm.com>,
Andy Gospodarek <andy@greyhouse•net>
Subject: Re: [PATCH v4 net-next 01/12] bonding: remove bond->lock from bond_arp_rcv
Date: Tue, 18 Feb 2014 07:12:22 +0100 [thread overview]
Message-ID: <20140218061222.GA18373@redhat.com> (raw)
In-Reply-To: <5302DB61.4070505@huawei.com>
On Tue, Feb 18, 2014 at 12:02:41PM +0800, Ding Tianhong wrote:
>On 2014/2/17 22:41, Veaceslav Falico wrote:
>> We're always called with rcu_read_lock() held (bond_arp_rcv() is only
>> called from bond_handle_frame(), which is rx_handler and always called
>> under rcu from __netif_receive_skb_core() ).
>>
>> The slave active/passive and/or bonding params can change in-flight, however
>> we don't really care about that - we only modify the last time packet was
>> received, which is harmless.
>>
>> CC: Jay Vosburgh <fubar@us•ibm.com>
>> CC: Andy Gospodarek <andy@greyhouse•net>
>> Signed-off-by: Veaceslav Falico <vfalico@redhat•com>
>> ---
>> drivers/net/bonding/bond_main.c | 3 ---
>> 1 file changed, 3 deletions(-)
>>
>> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
>> index 3bce855..3c50bec 100644
>> --- a/drivers/net/bonding/bond_main.c
>> +++ b/drivers/net/bonding/bond_main.c
>> @@ -2260,8 +2260,6 @@ int bond_arp_rcv(const struct sk_buff *skb, struct bonding *bond,
>> if (skb->protocol != __cpu_to_be16(ETH_P_ARP))
>> return RX_HANDLER_ANOTHER;
>>
>> - read_lock(&bond->lock);
>> -
>> if (!slave_do_arp_validate(bond, slave))
>> goto out_unlock;
>>
>> @@ -2318,7 +2316,6 @@ int bond_arp_rcv(const struct sk_buff *skb, struct bonding *bond,
>> bond_validate_arp(bond, slave, tip, sip);
>>
>> out_unlock:
>> - read_unlock(&bond->lock);
>> if (arp != (struct arphdr *)skb->data)
>> kfree(arp);
>> return RX_HANDLER_ANOTHER;
>>
>
>I think it is not enough, you should add rcu_dereference for bond->curr_active_slave, it may be changed during
>the recv processing.
bond->lock has absolutely nothing to du with bond->curr_active_slave .
>
>Regards
>Ding
>
>
next prev parent reply other threads:[~2014-02-18 6:12 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-17 14:41 [PATCH v4 net-next 0/12] bonding: add an option to rely on unvalidated arp packets Veaceslav Falico
2014-02-17 14:41 ` [PATCH v4 net-next 01/12] bonding: remove bond->lock from bond_arp_rcv Veaceslav Falico
2014-02-18 4:02 ` Ding Tianhong
2014-02-18 6:12 ` Veaceslav Falico [this message]
2014-02-18 7:07 ` Ding Tianhong
2014-02-18 7:10 ` Veaceslav Falico
2014-02-17 14:41 ` [PATCH v4 net-next 02/12] bonding: permit using arp_validate with non-ab modes Veaceslav Falico
2014-02-17 15:22 ` Nikolay Aleksandrov
2014-02-18 6:39 ` Veaceslav Falico
2014-02-17 14:41 ` [PATCH v4 net-next 03/12] bonding: always update last_arp_rx on packet recieve Veaceslav Falico
2014-02-17 14:41 ` [PATCH v4 net-next 04/12] bonding: always set recv_probe to bond_arp_rcv in arp monitor Veaceslav Falico
2014-02-17 14:41 ` [PATCH v4 net-next 05/12] bonding: extend arp_validate to be able to receive unvalidated arp-only traffic Veaceslav Falico
2014-02-17 14:41 ` [PATCH v4 net-next 06/12] bonding: document the new _arp options for arp_validate Veaceslav Falico
2014-02-17 14:41 ` [PATCH v4 net-next 07/12] bonding: use the new options to correctly set last_arp_rx Veaceslav Falico
2014-02-17 14:41 ` [PATCH v4 net-next 08/12] bonding: use last_arp_rx in slave_last_rx() Veaceslav Falico
2014-02-17 14:41 ` [PATCH v4 net-next 09/12] bonding: use last_arp_rx in bond_loadbalance_arp_mon() Veaceslav Falico
2014-02-17 14:41 ` [PATCH v4 net-next 10/12] bonding: remove useless updating of slave->dev->last_rx Veaceslav Falico
2014-02-17 14:41 ` [PATCH v4 net-next 11/12] bonding: trivial: rename slave->jiffies to ->last_link_up Veaceslav Falico
2014-02-17 15:02 ` David Laight
2014-02-17 15:15 ` Veaceslav Falico
2014-02-17 14:41 ` [PATCH v4 net-next 12/12] bonding: rename last_arp_rx to last_rx Veaceslav Falico
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20140218061222.GA18373@redhat.com \
--to=vfalico@redhat$(echo .)com \
--cc=andy@greyhouse$(echo .)net \
--cc=dingtianhong@huawei$(echo .)com \
--cc=fubar@us$(echo .)ibm.com \
--cc=netdev@vger$(echo .)kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox