Linux-OMAP Archive on lore.kernel.org
 help / color / Atom feed
From: Vladimir Oltean <olteanv@gmail.com>
To: Tobias Waldekranz <tobias@waldekranz.com>
Cc: Jakub Kicinski <kuba@kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	Andrew Lunn <andrew@lunn.ch>,
	Vivien Didelot <vivien.didelot@gmail.com>,
	Florian Fainelli <f.fainelli@gmail.com>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	Roopa Prabhu <roopa@nvidia.com>,
	Nikolay Aleksandrov <nikolay@nvidia.com>,
	Jiri Pirko <jiri@resnulli.us>, Ido Schimmel <idosch@idosch.org>,
	Alexandre Belloni <alexandre.belloni@bootlin.com>,
	UNGLinuxDriver@microchip.com, Vadym Kochan <vkochan@marvell.com>,
	Taras Chornyi <tchornyi@marvell.com>,
	Grygorii Strashko <grygorii.strashko@ti.com>,
	Vignesh Raghavendra <vigneshr@ti.com>,
	Ioana Ciornei <ioana.ciornei@nxp.com>,
	Ivan Vecera <ivecera@redhat.com>,
	linux-omap@vger.kernel.org,
	Vladimir Oltean <vladimir.oltean@nxp.com>
Subject: Re: [RFC PATCH v2 net-next 09/16] net: dsa: replay port and local fdb entries when joining the bridge
Date: Mon, 22 Mar 2021 19:13:28 +0200
Message-ID: <20210322171328.6ctmzyullywm3qmk@skbuf> (raw)
In-Reply-To: <87o8fbm80o.fsf@waldekranz.com>

On Mon, Mar 22, 2021 at 06:07:51PM +0100, Tobias Waldekranz wrote:
> On Mon, Mar 22, 2021 at 18:19, Vladimir Oltean <olteanv@gmail.com> wrote:
> > On Mon, Mar 22, 2021 at 04:44:41PM +0100, Tobias Waldekranz wrote:
> >> I do not know if it is a problem or not, more of an observation: This is
> >> not guaranteed to be an exact replay of the events that the bridge port
> >> (i.e. bond0 or whatever) has received since, in fdb_insert, we exit
> >> early when adding local entries if that address is already in the
> >> database.
> >> 
> >> Do we have to guard against this somehow? Or maybe we should consider
> >> the current behavior a bug and make sure to always send the event in the
> >> first place?
> >
> > I don't really understand what you're saying.
> > fdb_insert has:
> >
> > 	fdb = br_fdb_find(br, addr, vid);
> > 	if (fdb) {
> > 		/* it is okay to have multiple ports with same
> > 		 * address, just use the first one.
> > 		 */
> > 		if (test_bit(BR_FDB_LOCAL, &fdb->flags))
> > 			return 0;
> > 		br_warn(br, "adding interface %s with same address as a received packet (addr:%pM, vlan:%u)\n",
> > 		       source ? source->dev->name : br->dev->name, addr, vid);
> > 		fdb_delete(br, fdb, true);
> > 	}
> >
> > 	fdb = fdb_create(br, source, addr, vid,
> > 			 BIT(BR_FDB_LOCAL) | BIT(BR_FDB_STATIC));
> >
> > Basically, if the {addr, vid} pair already exists in the fdb, and it
> > points to a local entry, fdb_create is bypassed.
> >
> > Whereas my br_fdb_replay() function iterates over br->fdb_list, which is
> > exactly where fdb_create() also lays its eggs. That is to say, unless
> > I'm missing something, that duplicate local FDB entries that skipped the
> > fdb_create() call in fdb_insert() because they were for already-existing
> > local FDB entries will also be skipped by br_fdb_replay(), because it
> > iterates over a br->fdb_list which contains unique local addresses.
> > Where am I wrong?
> 
> No you are right. I was thinking back to my attempt of offloading local
> addresses and I distinctly remembered that local addresses could be
> added without a notification being sent.
> 
> But that is not what is happening. It is just already inserted on
> another port. So the notification would reach DSA, or not, depending on
> ordering the of events. But there will be no discrepancy between that
> and the replay.

I'm not saying that the bridge isn't broken, because it is, but for
different reasons, as explained here:
https://patchwork.kernel.org/project/netdevbpf/patch/20210224114350.2791260-9-olteanv@gmail.com/

What I can do is I can make br_switchdev_fdb_notify() skip fdb entries
with the BR_FDB_LOCAL bit set, and target that patch against "net", with
a Fixes: tag of 6b26b51b1d13 ("net: bridge: Add support for notifying
devices about FDB add/del").
Then I can also skip the entries with BR_FDB_LOCAL from br_fdb_replay.
Then, when I return to the "RX filtering for DSA" series, I can add the
"is_local" bit to switchdev FDB objects, and make all drivers reject
"is_local" entries (which is what the linked patch does) unless more
specific treatment is applied to those (trap to CPU).
Nikolay?

  reply index

Thread overview: 52+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-18 23:18 [RFC PATCH v2 net-next 00/16] Better support for sandwiched LAGs with bridge and DSA Vladimir Oltean
2021-03-18 23:18 ` [RFC PATCH v2 net-next 01/16] net: dsa: call dsa_port_bridge_join when joining a LAG that is already in a bridge Vladimir Oltean
2021-03-19 22:04   ` Florian Fainelli
2021-03-22 10:24   ` Tobias Waldekranz
2021-03-18 23:18 ` [RFC PATCH v2 net-next 02/16] net: dsa: pass extack to dsa_port_{bridge,lag}_join Vladimir Oltean
2021-03-19 22:05   ` Florian Fainelli
2021-03-22 10:25   ` Tobias Waldekranz
2021-03-18 23:18 ` [RFC PATCH v2 net-next 03/16] net: dsa: inherit the actual bridge port flags at join time Vladimir Oltean
2021-03-19 22:08   ` Florian Fainelli
2021-03-20 10:05     ` Vladimir Oltean
2021-03-18 23:18 ` [RFC PATCH v2 net-next 04/16] net: dsa: sync up with bridge port's STP state when joining Vladimir Oltean
2021-03-19 22:11   ` Florian Fainelli
2021-03-22 10:29   ` Tobias Waldekranz
2021-03-18 23:18 ` [RFC PATCH v2 net-next 05/16] net: dsa: sync up VLAN filtering state when joining the bridge Vladimir Oltean
2021-03-19 22:11   ` Florian Fainelli
2021-03-22 10:30   ` Tobias Waldekranz
2021-03-18 23:18 ` [RFC PATCH v2 net-next 06/16] net: dsa: sync multicast router " Vladimir Oltean
2021-03-19 22:12   ` Florian Fainelli
2021-03-22 11:17   ` Tobias Waldekranz
2021-03-22 11:43     ` Vladimir Oltean
2021-03-18 23:18 ` [RFC PATCH v2 net-next 07/16] net: dsa: sync ageing time " Vladimir Oltean
2021-03-19 22:13   ` Florian Fainelli
2021-03-20 10:09     ` Vladimir Oltean
2021-03-22 11:20   ` Tobias Waldekranz
2021-03-18 23:18 ` [RFC PATCH v2 net-next 08/16] net: dsa: replay port and host-joined mdb entries " Vladimir Oltean
2021-03-19 22:20   ` Florian Fainelli
2021-03-20  9:53     ` Vladimir Oltean
2021-03-22 15:56       ` Florian Fainelli
2021-03-18 23:18 ` [RFC PATCH v2 net-next 09/16] net: dsa: replay port and local fdb " Vladimir Oltean
2021-03-22 15:44   ` Tobias Waldekranz
2021-03-22 16:19     ` Vladimir Oltean
2021-03-22 17:07       ` Tobias Waldekranz
2021-03-22 17:13         ` Vladimir Oltean [this message]
2021-03-18 23:18 ` [RFC PATCH v2 net-next 10/16] net: dsa: replay VLANs installed on port " Vladimir Oltean
2021-03-19 22:24   ` Florian Fainelli
2021-03-18 23:18 ` [RFC PATCH v2 net-next 11/16] net: ocelot: support multiple bridges Vladimir Oltean
2021-03-18 23:18 ` [RFC PATCH v2 net-next 12/16] net: ocelot: call ocelot_netdevice_bridge_join when joining a bridged LAG Vladimir Oltean
2021-03-18 23:18 ` [RFC PATCH v2 net-next 13/16] net: ocelot: replay switchdev events when joining bridge Vladimir Oltean
2021-03-18 23:18 ` [RFC PATCH v2 net-next 14/16] net: dsa: don't set skb->offload_fwd_mark when not offloading the bridge Vladimir Oltean
2021-03-19  8:52   ` DENG Qingfang
2021-03-19  9:06     ` Vladimir Oltean
2021-03-19  9:29       ` DENG Qingfang
2021-03-19 10:49         ` Vladimir Oltean
2021-03-22  8:04           ` DENG Qingfang
2021-03-22 22:23             ` Vladimir Oltean
2021-03-22 16:06   ` Florian Fainelli
2021-03-18 23:18 ` [RFC PATCH v2 net-next 15/16] net: dsa: return -EOPNOTSUPP when driver does not implement .port_lag_join Vladimir Oltean
2021-03-22 15:51   ` Florian Fainelli
2021-03-22 15:58   ` Tobias Waldekranz
2021-03-18 23:18 ` [RFC PATCH v2 net-next 16/16] net: bridge: switchdev: let drivers inform which bridge ports are offloaded Vladimir Oltean
2021-03-22 16:30   ` Tobias Waldekranz
2021-03-22 17:19     ` Vladimir Oltean

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210322171328.6ctmzyullywm3qmk@skbuf \
    --to=olteanv@gmail.com \
    --cc=UNGLinuxDriver@microchip.com \
    --cc=alexandre.belloni@bootlin.com \
    --cc=andrew@lunn.ch \
    --cc=davem@davemloft.net \
    --cc=f.fainelli@gmail.com \
    --cc=grygorii.strashko@ti.com \
    --cc=idosch@idosch.org \
    --cc=ioana.ciornei@nxp.com \
    --cc=ivecera@redhat.com \
    --cc=jiri@resnulli.us \
    --cc=kuba@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-omap@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=nikolay@nvidia.com \
    --cc=roopa@nvidia.com \
    --cc=tchornyi@marvell.com \
    --cc=tobias@waldekranz.com \
    --cc=vigneshr@ti.com \
    --cc=vivien.didelot@gmail.com \
    --cc=vkochan@marvell.com \
    --cc=vladimir.oltean@nxp.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-OMAP Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-omap/0 linux-omap/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-omap linux-omap/ https://lore.kernel.org/linux-omap \
		linux-omap@vger.kernel.org
	public-inbox-index linux-omap

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-omap


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git