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net: sched: cls_rcvp, complete rcu conversion 

This completes the cls_rsvp conversion to RCU safe
copy, update semantics.

As a result all cases of tcf_exts_change occur on
empty lists now.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
John Fastabend 2014-09-26 10:02:50 -07:00 committed by David S. Miller
parent 3d9a0d2f82
commit 53dfd50181
1 changed files with 42 additions and 4 deletions
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46
net/sched/cls_rsvp.h
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@ -222,6 +222,33 @@ static int rsvp_classify(struct sk_buff *skb, const struct tcf_proto *tp,
return -1;
}
static void rsvp_replace(struct tcf_proto *tp, struct rsvp_filter *n, u32 h)
{
struct rsvp_head *head = rtnl_dereference(tp->root);
struct rsvp_session *s;
struct rsvp_filter __rcu **ins;
struct rsvp_filter *pins;
unsigned int h1 = h & 0xFF;
unsigned int h2 = (h >> 8) & 0xFF;
for (s = rtnl_dereference(head->ht[h1]); s;
s = rtnl_dereference(s->next)) {
for (ins = &s->ht[h2], pins = rtnl_dereference(*ins); ;
ins = &pins->next, pins = rtnl_dereference(*ins)) {
if (pins->handle == h) {
RCU_INIT_POINTER(n->next, pins->next);
rcu_assign_pointer(*ins, n);
return;
}
}
}
/* Something went wrong if we are trying to replace a non-existant
* node. Mind as well halt instead of silently failing.
*/
BUG_ON(1);
}
static unsigned long rsvp_get(struct tcf_proto *tp, u32 handle)
{
struct rsvp_head *head = rtnl_dereference(tp->root);
@ -454,15 +481,26 @@ static int rsvp_change(struct net *net, struct sk_buff *in_skb,
f = (struct rsvp_filter *)*arg;
if (f) {
/* Node exists: adjust only classid */
struct rsvp_filter *n;
if (f->handle != handle && handle)
goto errout2;
if (tb[TCA_RSVP_CLASSID]) {
f->res.classid = nla_get_u32(tb[TCA_RSVP_CLASSID]);
tcf_bind_filter(tp, &f->res, base);
n = kmemdup(f, sizeof(*f), GFP_KERNEL);
if (!n) {
err = -ENOMEM;
goto errout2;
}
tcf_exts_change(tp, &f->exts, &e);
tcf_exts_init(&n->exts, TCA_RSVP_ACT, TCA_RSVP_POLICE);
if (tb[TCA_RSVP_CLASSID]) {
n->res.classid = nla_get_u32(tb[TCA_RSVP_CLASSID]);
tcf_bind_filter(tp, &n->res, base);
}
tcf_exts_change(tp, &n->exts, &e);
rsvp_replace(tp, n, handle);
return 0;
}