Re: [PATCH mptcp-next v3 5/9] mptcp: drop free_list for deleting entries

[Matthieu Baerts <matttbe@kernel.org>]

Hi Geliang,

On 07/11/2024 07:45, Geliang Tang wrote:
> From: Geliang Tang <tanggeliang@kylinos.cn>
> 
> mptcp_pm_remove_addrs() actually only deletes one address, which does
> not match its name. This patch renames it to mptcp_pm_remove_addr_entry()
> and changes the parameter "rm_list" to "entry".
> 
> With the help of mptcp_pm_remove_addr_entry(), it's no longer necessary to
> move the entry to be deleted to free_list and then traverse the list to
> delete the entry, which is not allowed in BPF. The entry can be directly
> deleted through list_del_rcu() and sock_kfree_s() now.
> 
> Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
> ---
>  net/mptcp/pm_userspace.c | 33 ++++++++++++---------------------
>  net/mptcp/protocol.h     |  3 ++-
>  2 files changed, 14 insertions(+), 22 deletions(-)
> 
> diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
> index 737a07f5defe..a98da9a44bfa 100644
> --- a/net/mptcp/pm_userspace.c
> +++ b/net/mptcp/pm_userspace.c
> @@ -286,26 +286,21 @@ static int mptcp_userspace_pm_remove_id_zero_address(struct mptcp_sock *msk,
>  	return err;
>  }
>  
> -void mptcp_pm_remove_addrs(struct mptcp_sock *msk, struct list_head *rm_list)
> +void mptcp_pm_remove_addr_entry(struct mptcp_sock *msk,
> +				struct mptcp_pm_addr_entry *entry)
>  {
>  	struct mptcp_rm_list alist = { .nr = 0 };
> -	struct mptcp_pm_addr_entry *entry;
>  	int anno_nr = 0;
>  
> -	list_for_each_entry(entry, rm_list, list) {
> -		if (alist.nr >= MPTCP_RM_IDS_MAX)
> -			break;
> -
> -		/* only delete if either announced or matching a subflow */
> -		if (mptcp_remove_anno_list_by_saddr(msk, &entry->addr))
> -			anno_nr++;
> -		else if (!mptcp_lookup_subflow_by_saddr(&msk->conn_list,
> -							&entry->addr))
> -			continue;
> +	/* only delete if either announced or matching a subflow */
> +	if (mptcp_remove_anno_list_by_saddr(msk, &entry->addr))
> +		anno_nr++;
> +	else if (!mptcp_lookup_subflow_by_saddr(&msk->conn_list, &entry->addr))
> +		goto out;

Here, you can 'return', no need to use this new 'out' label.

>  
> -		alist.ids[alist.nr++] = entry->addr.id;
> -	}
> +	alist.ids[alist.nr++] = entry->addr.id;
>  
> +out:
>  	if (alist.nr) {

If the 'out' label is removed, you can also remove this if-statement.

>  		spin_lock_bh(&msk->pm.lock);
>  		msk->pm.add_addr_signaled -= anno_nr;

(...)

Cheers,
Matt
-- 
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