linux/include/net/tc_act
Alexei Starovoitov cff82457c5 net_sched: act_bpf: remove spinlock in fast path
Similar to act_gact/act_mirred, act_bpf can be lockless in packet processing
with extra care taken to free bpf programs after rcu grace period.
Replacement of existing act_bpf (very rare) is done with synchronize_rcu()
and final destruction is done from tc_action_ops->cleanup() callback that is
called from tcf_exts_destroy()->tcf_action_destroy()->__tcf_hash_release() when
bind and refcnt reach zero which is only possible when classifier is destroyed.
Previous two patches fixed the last two classifiers (tcindex and rsvp) to
call tcf_exts_destroy() from rcu callback.

Similar to gact/mirred there is a race between prog->filter and
prog->tcf_action. Meaning that the program being replaced may use
previous default action if it happened to return TC_ACT_UNSPEC.
act_mirred race betwen tcf_action and tcfm_dev is similar.
In all cases the race is harmless.
Long term we may want to improve the situation by replacing the whole
tc_action->priv as single pointer instead of updating inner fields one by one.

Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-26 11:01:45 -07:00
..
tc_bpf.h net_sched: act_bpf: remove spinlock in fast path 2015-08-26 11:01:45 -07:00
tc_connmark.h net: sched: Introduce connmark action 2015-01-19 16:02:06 -05:00
tc_csum.h net_sched: act: hide struct tcf_common from API 2014-02-12 19:23:32 -05:00
tc_defact.h net_sched: act: hide struct tcf_common from API 2014-02-12 19:23:32 -05:00
tc_gact.h net_sched: act_gact: use a separate packet counters for gact_determ() 2015-07-08 13:50:42 -07:00
tc_ipt.h net_sched: act: hide struct tcf_common from API 2014-02-12 19:23:32 -05:00
tc_mirred.h net_sched: act_mirred: remove spinlock in fast path 2015-07-08 13:50:42 -07:00
tc_nat.h net_sched: act: hide struct tcf_common from API 2014-02-12 19:23:32 -05:00
tc_pedit.h net_sched: act: hide struct tcf_common from API 2014-02-12 19:23:32 -05:00
tc_skbedit.h net_sched: act: hide struct tcf_common from API 2014-02-12 19:23:32 -05:00
tc_vlan.h tc_vlan: fix type of tcfv_push_vid 2014-11-24 16:12:03 -05:00