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| author | John Fastabend <john.fastabend@gmail.com> | 2014-09-12 20:05:27 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-09-13 12:30:25 -0400 |
| commit | 25d8c0d55f241ce2d360df1bea48e23a55836ee6 (patch) | |
| tree | c0aca67607e7ce560a4a2cebef5fb6d55adf4112 /net/sched/sch_atm.c | |
| parent | 46e5da40aec256155cfedee96dd21a75da941f2c (diff) | |
| download | lwn-25d8c0d55f241ce2d360df1bea48e23a55836ee6.tar.gz lwn-25d8c0d55f241ce2d360df1bea48e23a55836ee6.zip | |
net: rcu-ify tcf_proto
rcu'ify tcf_proto this allows calling tc_classify() without holding
any locks. Updaters are protected by RTNL.
This patch prepares the core net_sched infrastracture for running
the classifier/action chains without holding the qdisc lock however
it does nothing to ensure cls_xxx and act_xxx types also work without
locking. Additional patches are required to address the fall out.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched/sch_atm.c')
| -rw-r--r-- | net/sched/sch_atm.c | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/net/sched/sch_atm.c b/net/sched/sch_atm.c index 8449b337f9e3..c398f9c3dbdd 100644 --- a/net/sched/sch_atm.c +++ b/net/sched/sch_atm.c @@ -41,7 +41,7 @@ struct atm_flow_data { struct Qdisc *q; /* FIFO, TBF, etc. */ - struct tcf_proto *filter_list; + struct tcf_proto __rcu *filter_list; struct atm_vcc *vcc; /* VCC; NULL if VCC is closed */ void (*old_pop)(struct atm_vcc *vcc, struct sk_buff *skb); /* chaining */ @@ -273,7 +273,7 @@ static int atm_tc_change(struct Qdisc *sch, u32 classid, u32 parent, error = -ENOBUFS; goto err_out; } - flow->filter_list = NULL; + RCU_INIT_POINTER(flow->filter_list, NULL); flow->q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, classid); if (!flow->q) flow->q = &noop_qdisc; @@ -311,7 +311,7 @@ static int atm_tc_delete(struct Qdisc *sch, unsigned long arg) pr_debug("atm_tc_delete(sch %p,[qdisc %p],flow %p)\n", sch, p, flow); if (list_empty(&flow->list)) return -EINVAL; - if (flow->filter_list || flow == &p->link) + if (rcu_access_pointer(flow->filter_list) || flow == &p->link) return -EBUSY; /* * Reference count must be 2: one for "keepalive" (set at class @@ -345,7 +345,8 @@ static void atm_tc_walk(struct Qdisc *sch, struct qdisc_walker *walker) } } -static struct tcf_proto **atm_tc_find_tcf(struct Qdisc *sch, unsigned long cl) +static struct tcf_proto __rcu **atm_tc_find_tcf(struct Qdisc *sch, + unsigned long cl) { struct atm_qdisc_data *p = qdisc_priv(sch); struct atm_flow_data *flow = (struct atm_flow_data *)cl; @@ -369,11 +370,12 @@ static int atm_tc_enqueue(struct sk_buff *skb, struct Qdisc *sch) flow = NULL; if (TC_H_MAJ(skb->priority) != sch->handle || !(flow = (struct atm_flow_data *)atm_tc_get(sch, skb->priority))) { + struct tcf_proto *fl; + list_for_each_entry(flow, &p->flows, list) { - if (flow->filter_list) { - result = tc_classify_compat(skb, - flow->filter_list, - &res); + fl = rcu_dereference_bh(flow->filter_list); + if (fl) { + result = tc_classify_compat(skb, fl, &res); if (result < 0) continue; flow = (struct atm_flow_data *)res.class; @@ -544,7 +546,7 @@ static int atm_tc_init(struct Qdisc *sch, struct nlattr *opt) if (!p->link.q) p->link.q = &noop_qdisc; pr_debug("atm_tc_init: link (%p) qdisc %p\n", &p->link, p->link.q); - p->link.filter_list = NULL; + RCU_INIT_POINTER(p->link.filter_list, NULL); p->link.vcc = NULL; p->link.sock = NULL; p->link.classid = sch->handle; |