Re: [PATCH v2 4/5] ipvlan: protect addresses with internal spinlock

[Mahesh Bandewar <maheshb@google.com>]

On Fri, Jul 3, 2015 at 5:58 AM, Konstantin Khlebnikov
<khlebnikov@yandex-team.ru> wrote:
> Inet6addr notifier is atomic and runs in bh context without RTNL when
> ipv6 receives router advertisement packet and performs autoconfiguration.
>
> This patch adds ipvl_port->addr_lock and helpers: ipvlan_addr_lock_bh,
> ipvlan_addr_unlock_bh for protecting ipvlan addresses and hash table.
>
Frankly I'm not comfortable adding spin-locks all over. I think any
config that mostly takes place with RTNL makes sense but this
inet6addr needs to be thought through and implanting spin-locks in
IPvlan is a work-around for a problem some where else.
Why can't a work-queue that takes RTNL to call inet6addr-notifier be
implemented when called from bh?

> Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
> ---
>  drivers/net/ipvlan/ipvlan.h      |   11 +++++++++++
>  drivers/net/ipvlan/ipvlan_core.c |    2 --
>  drivers/net/ipvlan/ipvlan_main.c |   33 ++++++++++++++++++++++++++++++---
>  3 files changed, 41 insertions(+), 5 deletions(-)
>
[snip]