From: Jiri Pirko <j...@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 -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
