Re: [PATCH v6 1/4] mptcp: fix ADD_ADDR and RM_ADDR maybe flush addr_signal each other

From: Geliang Tang <geliangtang@gmail.com>
To: Yonglong Li <liyonglong@chinatelecom.cn>
Cc: mptcp@lists.linux.dev,
	Mat Martineau <mathew.j.martineau@linux.intel.com>
Subject: Re: [PATCH v6 1/4] mptcp: fix ADD_ADDR and RM_ADDR maybe flush addr_signal each other
Date: Tue, 29 Jun 2021 13:43:55 +0800	[thread overview]
Message-ID: <CA+WQbwtxcHsHvthHp65NX=Y0uHuHpMXv1d9W0S=fEY=rUQEW_A@mail.gmail.com> (raw)
In-Reply-To: <1624930899-99623-2-git-send-email-liyonglong@chinatelecom.cn>

Hi Yonglong,

Thank you for this new patch set!

Yonglong Li <liyonglong@chinatelecom.cn> 于2021年6月29日周二 上午9:42写道：
>
> 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..6c427c8 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;

Here we should use the reverse xmas tree order for variables definition:
        int ret = false;
        u8 add_addr;

>
>         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_ADD_ADDR_SIGNAL) | BIT(MPTCP_ADD_ADDR_ECHO));

I think we could use mptcp_pm_should_add_signal_echo to choose ECHO or
SIGNAL to set here:
      if (mptcp_pm_should_add_signal_echo(msk))
              add_addr = msk->pm.addr_signal & ~BIT(MPTCP_ADD_ADDR_ECHO);
      else
              add_addr = msk->pm.addr_signal & ~BIT(MPTCP_ADD_ADDR_SIGNAL);

> +       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
>