From 53dfd501819a6e9c3a7d56cac1ddaf03fe90800d Mon Sep 17 00:00:00 2001 From: John Fastabend Date: Fri, 26 Sep 2014 10:02:50 -0700 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- net/sched/cls_rsvp.h | 44 +++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 41 insertions(+), 3 deletions(-) diff --git a/net/sched/cls_rsvp.h b/net/sched/cls_rsvp.h index 1c64a09753c4..6bb55f277a5a 100644 --- a/net/sched/cls_rsvp.h +++ b/net/sched/cls_rsvp.h @@ -222,6 +222,33 @@ matched: 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; } -- 2.20.1