From 25d8c0d55f241ce2d360df1bea48e23a55836ee6 Mon Sep 17 00:00:00 2001 From: John Fastabend Date: Fri, 12 Sep 2014 20:05:27 -0700 Subject: 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 Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- net/sched/sch_htb.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) (limited to 'net/sched/sch_htb.c') diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c index aea942ce6008..6d16b9b81c28 100644 --- a/net/sched/sch_htb.c +++ b/net/sched/sch_htb.c @@ -103,7 +103,7 @@ struct htb_class { u32 prio; /* these two are used only by leaves... */ int quantum; /* but stored for parent-to-leaf return */ - struct tcf_proto *filter_list; /* class attached filters */ + struct tcf_proto __rcu *filter_list; /* class attached filters */ int filter_cnt; int refcnt; /* usage count of this class */ @@ -153,7 +153,7 @@ struct htb_sched { int rate2quantum; /* quant = rate / rate2quantum */ /* filters for qdisc itself */ - struct tcf_proto *filter_list; + struct tcf_proto __rcu *filter_list; #define HTB_WARN_TOOMANYEVENTS 0x1 unsigned int warned; /* only one warning */ @@ -223,9 +223,9 @@ static struct htb_class *htb_classify(struct sk_buff *skb, struct Qdisc *sch, if (cl->level == 0) return cl; /* Start with inner filter chain if a non-leaf class is selected */ - tcf = cl->filter_list; + tcf = rcu_dereference_bh(cl->filter_list); } else { - tcf = q->filter_list; + tcf = rcu_dereference_bh(q->filter_list); } *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; @@ -251,7 +251,7 @@ static struct htb_class *htb_classify(struct sk_buff *skb, struct Qdisc *sch, return cl; /* we hit leaf; return it */ /* we have got inner class; apply inner filter chain */ - tcf = cl->filter_list; + tcf = rcu_dereference_bh(cl->filter_list); } /* classification failed; try to use default class */ cl = htb_find(TC_H_MAKE(TC_H_MAJ(sch->handle), q->defcls), sch); @@ -1519,11 +1519,12 @@ failure: return err; } -static struct tcf_proto **htb_find_tcf(struct Qdisc *sch, unsigned long arg) +static struct tcf_proto __rcu **htb_find_tcf(struct Qdisc *sch, + unsigned long arg) { struct htb_sched *q = qdisc_priv(sch); struct htb_class *cl = (struct htb_class *)arg; - struct tcf_proto **fl = cl ? &cl->filter_list : &q->filter_list; + struct tcf_proto __rcu **fl = cl ? &cl->filter_list : &q->filter_list; return fl; } -- cgit v1.2.3