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From:   Jon Maloy <jon.maloy@ericsson.com>
To:     Chris Packham <chris.packham@alliedtelesis.co.nz>,
        "ying.xue@windriver.com" <ying.xue@windriver.com>,
        "davem@davemloft.net" <davem@davemloft.net>
CC:     "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
        "tipc-discussion@lists.sourceforge.net" 
        <tipc-discussion@lists.sourceforge.net>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH] tipc: set addr_trail_end when using explicit node
 addresses
Thread-Topic: [PATCH] tipc: set addr_trail_end when using explicit node
 addresses
Thread-Index: AQHVTNxmcyx4K5X64kCOEEbx4BfRSKbxVbDQ
Date:   Thu, 8 Aug 2019 14:49:59 +0000
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References: <20190807045543.28373-1-chris.packham@alliedtelesis.co.nz>
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You should rather set this one unconditionally in tipc_set_node_addr().
The problems is not about the state machine, but that jiffies is close to t=
he wrap-around time, so that it is perceived as being before the time "0".

BR
///jon


> -----Original Message-----
> From: netdev-owner@vger.kernel.org <netdev-owner@vger.kernel.org> On
> Behalf Of Chris Packham
> Sent: 7-Aug-19 00:56
> To: Jon Maloy <jon.maloy@ericsson.com>; ying.xue@windriver.com;
> davem@davemloft.net
> Cc: netdev@vger.kernel.org; tipc-discussion@lists.sourceforge.net; linux-
> kernel@vger.kernel.org; Chris Packham <chris.packham@alliedtelesis.co.nz>
> Subject: [PATCH] tipc: set addr_trail_end when using explicit node addres=
ses
>=20
> When tipc uses auto-generated node addresses it goes through a duplicate
> address detection phase to ensure the address is unique.
>=20
> When using explicitly configured node names the DAD phase is skipped.
> However addr_trail_end was being left set to 0 which causes parts of the =
tipc
> state machine to assume that the address is not yet valid and unnecessari=
ly
> delays the discovery phase. By setting addr_trail_end to jiffies when usi=
ng
> explicit addresses we ensure that we move straight to discovery.
>=20
> Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
> ---
>  net/tipc/discover.c | 2 ++
>  1 file changed, 2 insertions(+)
>=20
> diff --git a/net/tipc/discover.c b/net/tipc/discover.c index
> c138d68e8a69..f83bfe8c9443 100644
> --- a/net/tipc/discover.c
> +++ b/net/tipc/discover.c
> @@ -361,6 +361,8 @@ int tipc_disc_create(struct net *net, struct
> tipc_bearer *b,
>  	if (!tipc_own_addr(net)) {
>  		tn->addr_trial_end =3D jiffies + msecs_to_jiffies(1000);
>  		msg_set_type(buf_msg(d->skb), DSC_TRIAL_MSG);
> +	} else {
> +		tn->addr_trial_end =3D jiffies;
>  	}
>  	memcpy(&d->dest, dest, sizeof(*dest));
>  	d->net =3D net;
> --
> 2.22.0