From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [PATCH net-next-2.6 1/2] net: Get rid of rtnl_link_stats64 /
 net_device_stats union
Date: Fri, 09 Jul 2010 23:08:54 +0200
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Cc: David Miller <davem@davemloft.net>, netdev@vger.kernel.org,
	linux-net-drivers@solarflare.com
To: Ben Hutchings <bhutchings@solarflare.com>
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Le vendredi 09 juillet 2010 =C3=A0 20:11 +0100, Ben Hutchings a =C3=A9c=
rit :
> In commit be1f3c2c027cc5ad735df6a45a542ed1db7ec48b "net: Enable 64-bi=
t
> net device statistics on 32-bit architectures" I redefined struct
> net_device_stats so that it could be used in a union with struct
> rtnl_link_stats64, avoiding the need for explicit copying or
> conversion between the two.  However, this is unsafe because there is
> no locking required and no lock consistently held around calls to
> dev_get_stats() and use of the statistics structure it returns.
>=20
> In commit 28172739f0a276eb8d6ca917b3974c2edb036da3 "net: fix 64 bit
> counters on 32 bit arches" Eric Dumazet dealt with that problem by
> requiring callers of dev_get_stats() to provide storage for the
> result.  This means that the net_device::stats64 field and the paddin=
g
> in struct net_device_stats are now redundant, so remove them.
>=20
> Update the comment on net_device_ops::ndo_get_stats64 to reflect its
> new usage.
>=20
> Change dev_txq_stats_fold() to use struct rtnl_link_stats64, since
> that is what all its callers are really using and it is no longer
> going to be compatible with struct net_device_stats.
>=20
> Eric Dumazet suggested the separate function for the structure
> conversion.
>=20
> Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Acked-by: Eric Dumazet <eric.dumazet@gmail.com>

Thanks !