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Commit 53dfd501 authored by John Fastabend's avatar John Fastabend Committed by David S. Miller
Browse files

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: default avatarJohn Fastabend <john.r.fastabend@intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 3d9a0d2f

net/sched/cls_rsvp.h

+41 −3
Original line number Diff line number Diff line
@@ -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;



		n = kmemdup(f, sizeof(*f), GFP_KERNEL);

		if (!n) {

			err = -ENOMEM;

			goto errout2;

		}



		tcf_exts_init(&n->exts, TCA_RSVP_ACT, TCA_RSVP_POLICE);



		if (tb[TCA_RSVP_CLASSID]) {

			f->res.classid = nla_get_u32(tb[TCA_RSVP_CLASSID]);

			tcf_bind_filter(tp, &f->res, base);

			n->res.classid = nla_get_u32(tb[TCA_RSVP_CLASSID]);

			tcf_bind_filter(tp, &n->res, base);

		}



		tcf_exts_change(tp, &f->exts, &e);

		tcf_exts_change(tp, &n->exts, &e);

		rsvp_replace(tp, n, handle);

		return 0;

	}