From: Vlad Yasevich <vyasevich@gmail•com>
To: Xin Long <lucien.xin@gmail•com>, network dev <netdev@vger•kernel.org>
Cc: mleitner@redhat•com, tgraf@infradead•org, davem@davemloft•net
Subject: Re: [PATCH net v2] sctp: donot reset the overall_error_count in SHUTDOWN_RECEIVE state
Date: Wed, 26 Aug 2015 11:19:20 -0400 [thread overview]
Message-ID: <55DDD8F8.4090400@gmail.com> (raw)
In-Reply-To: <46eeeb896c5be2523e3d978d4a7ea9907d4301ee.1440329415.git.lucien.xin@gmail.com>
On 08/23/2015 07:30 AM, Xin Long wrote:
> commit f8d960524 fix the 0 peer.rwnd issue in SHUTDOWN_PENDING state through
> not reseting the overall_error_count when receive a heartbeat, but the same
> issue also exists in SHUTDOWN_RECEIVE state.
>
> so we change the condition to state < SCTP_STATE_SHUTDOWN_PENDING to reset the
> overall_error_count when receive a heartbeat, which can avoid the issue happen
> in SCTP_STATE_SHUTDOWN_RECEIVE.
>
> as to SCTP_STATE_SHUTDOWN_ACK_SENT and SCTP_STATE_SHUTDOWN_SENT state, with
> this patch, it will not be affected by the heartbeat, cause these two states
> have been taken charge of by t2 timer.
>
> Fixes: f8d960524 ("sctp: Enforce retransmission limit during shutdown")
> Signed-off-by: Xin Long <lucien.xin@gmail•com>
The code is OK, but the change log could use some help.
How is this for the explanation:
Commit f8d960524 ("sctp: Enforce retransmission limit during shutdown") fixed a
problem with excessive retransmissions in the SHUTDOWN_PENDING by not resetting
the association overall_error_count. This allowed the association to better
enforce assoc.max_retrans limit.
However, the same issue still exists when the association is in SHUTDOWN_RECEIVED
state. In this state, HB-ACKs will continue to reset the overall_error_count
for the association would extend the lifetime of association unnecessarily.
This patch solves this by resetting the overall_error_count whenever the current
state is small then SCTP_STATE_SHUTDOWN_PENDING. As a small side-effect, we
end up also handling SCTP_STATE_SHUTDOWN_ACK_SENT and SCTP_STATE_SHUTDOWN_SENT
states, but they are not really impacted because we disable Heartbeats in those
states.
Thanks
-vlad
> ---
> net/sctp/sm_sideeffect.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c
> index fef2acd..85e6f03 100644
> --- a/net/sctp/sm_sideeffect.c
> +++ b/net/sctp/sm_sideeffect.c
> @@ -702,7 +702,7 @@ static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
> * outstanding data and rely on the retransmission limit be reached
> * to shutdown the association.
> */
> - if (t->asoc->state != SCTP_STATE_SHUTDOWN_PENDING)
> + if (t->asoc->state < SCTP_STATE_SHUTDOWN_PENDING)
> t->asoc->overall_error_count = 0;
>
> /* Clear the hb_sent flag to signal that we had a good
>
prev parent reply other threads:[~2015-08-26 15:19 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-23 11:30 [PATCH net v2] sctp: donot reset the overall_error_count in SHUTDOWN_RECEIVE state Xin Long
2015-08-26 2:46 ` David Miller
2015-08-26 15:19 ` Vlad Yasevich [this message]
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