From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:in-reply-to:references:date:message-id :mime-version; bh=hLvX9In1jxN1MmiovYwJxjgsn4VqeCvwwYBZvBi7CO8=; b=Zf5pwO/z+b6zqpeN5dacXhHvcrf713zmafvc8sSy8t0z52u5r1uZRhyV4XZIRIwmbC x9n8Lqxv0rn1j4Nbm2QnMzECR8pvFJTiTByr1e3drc2Iq2NcfyvHfg0L8zdP/N2L8lJO vzobpHKPSZIJE5msoH0TE9nsoYQRU3+MUmXzi470pixY+ZU9XG0skAFJXWd300AP9qfr vllNF++PhJAARRziXJriMiGeMnSlZ924JgNJDW16l+7DdV0C9GF9n0NqZI3rzpfyLPXo Gt7+b+rHI0t6L9g7xL6ZsKc2lth/J6/rJBTHaZti4GGG6cH7za1zCFafr8a+2CJZ+4kc aBvg== From: Hans Schultz In-Reply-To: <20220322110806.kbdb362jf6pbtqaf@skbuf> References: <20220317153625.2ld5zgtuhoxbcgvo@skbuf> <86ilscr2a4.fsf@gmail.com> <20220317161808.psftauoz5iaecduy@skbuf> <8635jg5xe5.fsf@gmail.com> <20220317172013.rhjvknre5w7mfmlo@skbuf> <86tubvk24r.fsf@gmail.com> <20220318121400.sdc4guu5m4auwoej@skbuf> <86pmmjieyl.fsf@gmail.com> <20220318131943.hc7z52beztqlzwfq@skbuf> <86a6dixnd2.fsf@gmail.com> <20220322110806.kbdb362jf6pbtqaf@skbuf> Date: Wed, 23 Mar 2022 11:13:51 +0100 Message-ID: <86fsn90ye8.fsf@gmail.com> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Bridge] [PATCH net-next 3/3] net: dsa: mv88e6xxx: mac-auth/MAB implementation List-Id: Linux Ethernet Bridging List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Vladimir Oltean , Hans Schultz Cc: Ivan Vecera , Andrew Lunn , Florian Fainelli , Jiri Pirko , Daniel Borkmann , netdev@vger.kernel.org, Nikolay Aleksandrov , bridge@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Vivien Didelot , Ido Schimmel , Roopa Prabhu , kuba@kernel.org, davem@davemloft.net On tis, mar 22, 2022 at 13:08, Vladimir Oltean wrote: > On Tue, Mar 22, 2022 at 12:01:13PM +0100, Hans Schultz wrote: >> On fre, mar 18, 2022 at 15:19, Vladimir Oltean wrote: >> > On Fri, Mar 18, 2022 at 02:10:26PM +0100, Hans Schultz wrote: >> >> In the offloaded case there is no difference between static and dynamic >> >> flags, which I see as a general issue. (The resulting ATU entry is static >> >> in either case.) >> > >> > It _is_ a problem. We had the same problem with the is_local bit. >> > Independently of this series, you can add the dynamic bit to struct >> > switchdev_notifier_fdb_info and make drivers reject it. >> > >> >> These FDB entries are removed when link goes down (soft or hard). The >> >> zero DPV entries that the new code introduces age out after 5 minutes, >> >> while the locked flagged FDB entries are removed by link down (thus the >> >> FDB and the ATU are not in sync in this case). >> > >> > Ok, so don't let them disappear from hardware, refresh them from the >> > driver, since user space and the bridge driver expect that they are >> > still there. >> >> I have now tested with two extra unmanaged switches (each connected to a >> seperate port on our managed switch, and when migrating from one port to >> another, there is member violations, but as the initial entry ages out, >> a new miss violation occurs and the new port adds the locked entry. In >> this case I only see one locked entry, either on the initial port or >> later on the port the host migrated to (via switch). >> >> If I refresh the ATU entries indefinitly, then this migration will for >> sure not work, and with the member violation suppressed, it will be >> silent about it. > > Manual says that migrations should trigger miss violations if configured > adequately, is this not the case? > >> So I don't think it is a good idea to refresh the ATU entries >> indefinitely. >> >> Another issue I see, is that there is a deadlock or similar issue when >> receiving violations and running 'bridge fdb show' (it seemed that >> member violations also caused this, but not sure yet...), as the unit >> freezes, not to return... > > Have you enabled lockdep, debug atomic sleep, detect hung tasks, things > like that? I have now determined that it is the rtnl_lock() that causes the "deadlock". The doit() in rtnetlink.c is under rtnl_lock() and is what takes care of getting the fdb entries when running 'bridge fdb show'. In principle there should be no problem with this, but I don't know if some interrupt queue is getting jammed as they are blocked from rtnetlink.c?