From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [net PATCH] net: sched: Fix for duplicate class dump
Date: Thu, 18 Oct 2018 16:00:44 -0700 (PDT)
Message-ID: <20181018.160044.75473782850101628.davem@davemloft.net>
References: <20181018083426.6623-1-phil@nwl.cc>
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From: Phil Sutter <phil@nwl.cc>
Date: Thu, 18 Oct 2018 10:34:26 +0200

> When dumping classes by parent, kernel would return classes twice:
> 
> | # tc qdisc add dev lo root prio
> | # tc class show dev lo
> | class prio 8001:1 parent 8001:
> | class prio 8001:2 parent 8001:
> | class prio 8001:3 parent 8001:
> | # tc class show dev lo parent 8001:
> | class prio 8001:1 parent 8001:
> | class prio 8001:2 parent 8001:
> | class prio 8001:3 parent 8001:
> | class prio 8001:1 parent 8001:
> | class prio 8001:2 parent 8001:
> | class prio 8001:3 parent 8001:
> 
> This comes from qdisc_match_from_root() potentially returning the root
> qdisc itself if its handle matched. Though in that case, root's classes
> were already dumped a few lines above.
> 
> Fixes: cb395b2010879 ("net: sched: optimize class dumps")
> Signed-off-by: Phil Sutter <phil@nwl.cc>

Applied and queued up for -stable, thanks Phil.