linux/drivers/net/team
Jason Wang f663dd9aaf net: core: explicitly select a txq before doing l2 forwarding
Currently, the tx queue were selected implicitly in ndo_dfwd_start_xmit(). The
will cause several issues:

- NETIF_F_LLTX were removed for macvlan, so txq lock were done for macvlan
  instead of lower device which misses the necessary txq synchronization for
  lower device such as txq stopping or frozen required by dev watchdog or
  control path.
- dev_hard_start_xmit() was called with NULL txq which bypasses the net device
  watchdog.
- dev_hard_start_xmit() does not check txq everywhere which will lead a crash
  when tso is disabled for lower device.

Fix this by explicitly introducing a new param for .ndo_select_queue() for just
selecting queues in the case of l2 forwarding offload. netdev_pick_tx() was also
extended to accept this parameter and dev_queue_xmit_accel() was used to do l2
forwarding transmission.

With this fixes, NETIF_F_LLTX could be preserved for macvlan and there's no need
to check txq against NULL in dev_hard_start_xmit(). Also there's no need to keep
a dedicated ndo_dfwd_start_xmit() and we can just reuse the code of
dev_queue_xmit() to do the transmission.

In the future, it was also required for macvtap l2 forwarding support since it
provides a necessary synchronization method.

Cc: John Fastabend <john.r.fastabend@intel.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: e1000-devel@lists.sourceforge.net
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-10 13:23:08 -05:00
..
Kconfig team: introduce random mode 2013-03-06 14:55:20 -05:00
Makefile team: introduce random mode 2013-03-06 14:55:20 -05:00
team_mode_activebackup.c team: ab: set active port option as changed when port is leaving 2013-02-04 14:55:45 -05:00
team_mode_broadcast.c team: introduce two default team_modeop functions and use them in modes 2013-03-06 14:55:20 -05:00
team_mode_loadbalance.c net: Explicitly initialize u64_stats_sync structures for lockdep 2013-11-06 12:40:25 +01:00
team_mode_random.c team: check return value of team_get_port_by_index_rcu() for NULL 2013-06-12 00:56:27 -07:00
team_mode_roundrobin.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-06-19 16:49:39 -07:00
team.c net: core: explicitly select a txq before doing l2 forwarding 2014-01-10 13:23:08 -05:00