Re: [patch net-next v3 0/7] switchdev: change locking

[Jiri Pirko <jiri@resnulli.us>]

Damn, wrong branch, please ignore, will send v4 shortly.

Mon, Oct 12, 2015 at 05:45:43PM CEST, jiri@resnulli.us wrote:
>From: Jiri Pirko <jiri@mellanox.com>
>
>This is something which I'm currently struggling with.
>Callers of attr_set and obj_add/del often hold not only RTNL, but also
>spinlock (bridge). So in that case, the driver implementing the op cannot sleep.
>
>The way rocker is dealing with this now is just to invoke driver operation
>and go out, without any checking or reporting of the operation status.
>
>Since it would be nice to at least put a warning in case the operation fails,
>it makes sense to do this in delayed work directly in switchdev core
>instead of implementing this in separate drivers. And that is what this patchset
>is introducing.
>
>So from now on, the locking of switchdev mod ops is consistent. Caller either
>holds rtnl mutex or in case it does not, caller sets defer flag, telling
>switchdev core to process the op later in delayed work.
>
>Flush function for switchdev deferred ops can be called by op
>caller in appropriate location, for example after it releases
>spin lock, to force switchdev core to process pending ops.
>
>v1->v2:
>- rebased on current net-next head (including Scott's ageing patchset)
>v2->v3:
>- fixed comment s/of/or/ typo suggested by Nik
>
>Jiri Pirko (7):
>  switchdev: assert rtnl in switchdev_port_obj_del
>  switchdev: introduce switchdev workqueue
>  switchdev: allow caller to explicitly request attr_set as deferred
>  switchdev: remove pointers from switchdev objects
>  switchdev: introduce possibility to defer obj_add/del
>  bridge: defer switchdev fdb del call in fdb_del_external_learn
>  rocker: remove nowait from switchdev callbacks.
>
> drivers/net/ethernet/rocker/rocker.c |  13 +-
> include/net/switchdev.h              |  14 +-
> net/bridge/br_fdb.c                  |   7 +-
> net/bridge/br_if.c                   |   3 +
> net/bridge/br_stp.c                  |   3 +-
> net/dsa/slave.c                      |   2 +-
> net/switchdev/switchdev.c            | 276 +++++++++++++++++++++++++----------
> 7 files changed, 222 insertions(+), 96 deletions(-)
>
>-- 
>1.9.3
>