From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [Patch net-next] bridge: fix seq check in br_mdb_dump()
Date: Mon, 10 Dec 2012 13:46:02 -0500 (EST)
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From: Cong Wang <amwang@redhat.com>
Date: Mon, 10 Dec 2012 20:15:35 +0800

> From: Cong Wang <amwang@redhat.com>
> 
> In case of rehashing, introduce a global variable 'br_mdb_rehash_seq'
> which gets increased every time when rehashing, and assign
> net->dev_base_seq + br_mdb_rehash_seq to cb->seq.
> 
> In theory cb->seq could be wrapped to zero, but this is not
> easy to fix, as net->dev_base_seq is not visible inside
> br_mdb_rehash(). In practice, this is rare.
> 
> Cc: Herbert Xu <herbert@gondor.apana.org.au>
> Cc: Stephen Hemminger <shemminger@vyatta.com>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Thomas Graf <tgraf@suug.ch>
> Cc: Jesper Dangaard Brouer <brouer@redhat.com>
> Signed-off-by: Cong Wang <amwang@redhat.com>

No synchronization at all is applied to this variable, I can't
see how this is OK.