Re: [PATCH v2 1/4] mptcp: fix ADD_ADDR and RM_ADDR maybe flush addr_signal each other

[Yonglong Li <liyonglong@chinatelecom.cn>]

On 2021/6/17 7:30, Mat Martineau wrote:
> On Tue, 15 Jun 2021, Yonglong Li wrote:
> 
>> ADD_ADDR share pm.addr_signal with RM_ADDR, so after RM_ADDR/ADD_ADDR
>> done we should not clean ADD_ADDR/RM_ADDR's addr_signal.
>>
>> Signed-off-by: Yonglong Li <liyonglong@chinatelecom.cn>
>> ---
>> net/mptcp/pm.c | 10 +++++++---
>> 1 file changed, 7 insertions(+), 3 deletions(-)
>>
>> diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
>> index 9d00fa6..74886a3 100644
>> --- a/net/mptcp/pm.c
>> +++ b/net/mptcp/pm.c
>> @@ -252,6 +252,7 @@ void mptcp_pm_mp_prio_received(struct sock *sk, u8 bkup)
>> bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
>>                   struct mptcp_addr_info *saddr, bool *echo, bool *port)
>> {
>> +    u8 add_addr;
>>     int ret = false;
>>
>>     spin_lock_bh(&msk->pm.lock);
>> @@ -267,7 +268,8 @@ bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
>>         goto out_unlock;
>>
>>     *saddr = msk->pm.local;
>> -    WRITE_ONCE(msk->pm.addr_signal, 0);
>> +    add_addr = msk->pm.addr_signal & BIT(MPTCP_RM_ADDR_SIGNAL);
> 
> Hello Yonglong, thank you for your revised patch series.
> 
> It would be better to use ~BIT(MPTCP_ADD_ADDR_SIGNAL), similar to the change in 
Hi Mat, Thanks for your review.
If use ~BIT(MPTCP_ADD_ADDR_SIGNAL), MPTCP_ADD_ADDR_ECHO maybe not being clean out. MPTCP_ADD_ADDR_ECHO
and MPTCP_ADD_ADDR_SIGNAL are being set with pm.lock at the same time, So I think here use
BIT(MPTCP_RM_ADDR_SIGNAL) is ok.

mptcp_pm_rm_addr_signal() below.
> 
>> +    WRITE_ONCE(msk->pm.addr_signal, add_addr);
>>     ret = true;
>>
>> out_unlock:
>> @@ -278,6 +280,7 @@ bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
>> bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
>>                  struct mptcp_rm_list *rm_list)
>> {
>> +    u8 rm_addr;
>>     int ret = false, len;
>>
>>     spin_lock_bh(&msk->pm.lock);
>> @@ -286,16 +289,17 @@ bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
>>     if (!mptcp_pm_should_rm_signal(msk))
>>         goto out_unlock;
>>
>> +    rm_addr = msk->pm.addr_signal & ~BIT(MPTCP_RM_ADDR_SIGNAL);
>>     len = mptcp_rm_addr_len(&msk->pm.rm_list_tx);
>>     if (len < 0) {
>> -        WRITE_ONCE(msk->pm.addr_signal, 0);
>> +        WRITE_ONCE(msk->pm.addr_signal, rm_addr);
>>         goto out_unlock;
>>     }
>>     if (remaining < len)
>>         goto out_unlock;
>>
>>     *rm_list = msk->pm.rm_list_tx;
>> -    WRITE_ONCE(msk->pm.addr_signal, 0);
>> +    WRITE_ONCE(msk->pm.addr_signal, rm_addr);
>>     ret = true;
>>
>> out_unlock:
>> -- 
>> 1.8.3.1
>>
>>
> 
> -- 
> Mat Martineau
> Intel
> 
>