On Sat, Mar 18, 2017 at 7:48 PM, Julian Anastasov <ja@xxxxxx> wrote:
>
> Hello,
>
> On Sat, 18 Mar 2017, Xin Long wrote:
>
>> Commit c86a773c7802 ("sctp: add dst_pending_confirm flag") introduced
>> a temporary variable "confirm" in sctp_packet_transmit.
>>
>> But it broke the rule that longer lines should be above shorter ones.
>> Besides, this variable is not necessary, so this patch is to just
>> remove it and use tp->dst_pending_confirm directly.
>>
>> Fixes: c86a773c7802 ("sctp: add dst_pending_confirm flag")
>> Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx>
>> ---
>> net/sctp/output.c | 7 +++----
>> 1 file changed, 3 insertions(+), 4 deletions(-)
>>
>> diff --git a/net/sctp/output.c b/net/sctp/output.c
>> index 71ce6b9..1224421 100644
>> --- a/net/sctp/output.c
>> +++ b/net/sctp/output.c
>> @@ -546,7 +546,6 @@ int sctp_packet_transmit(struct sctp_packet *packet, gfp_t gfp)
>> struct sctp_association *asoc = tp->asoc;
>> struct sctp_chunk *chunk, *tmp;
>> int pkt_count, gso = 0;
>> - int confirm;
>> struct dst_entry *dst;
>> struct sk_buff *head;
>> struct sctphdr *sh;
>> @@ -625,13 +624,13 @@ int sctp_packet_transmit(struct sctp_packet *packet, gfp_t gfp)
>> asoc->peer.last_sent_to = tp;
>> }
>> head->ignore_df = packet->ipfragok;
>> - confirm = tp->dst_pending_confirm;
>> - if (confirm)
>> + if (tp->dst_pending_confirm)
>> skb_set_dst_pending_confirm(head, 1);
>> /* neighbour should be confirmed on successful transmission or
>> * positive error
>> */
>> - if (tp->af_specific->sctp_xmit(head, tp) >= 0 && confirm)
>> + if (tp->af_specific->sctp_xmit(head, tp) >= 0 &&
>> + tp->dst_pending_confirm)
>> tp->dst_pending_confirm = 0;
>>
>> out:
>> --
>
> I played safe here, I was not sure if currently
> or some day in the future the SCTP stack can allow another
> thread to set tp->dst_pending_confirm concurrently with the
> sending. My idea was only when skb was used to confirm
> neighbour only then to clear the indication. I guess, your
> patch is ok because we should be locking the socket
> everywhere.
Yeps, It's safe, as all the codes for dst_pending_confirm are
under the sock lock protection.
>
> Regards
>
> --
> Julian Anastasov <ja@xxxxxx>
--
To unsubscribe from this list: send the line "unsubscribe linux-sctp" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
