net_sched: sch_ets: implement lockless ets_dump()
[ Upstream commit c5f1dde7f731e7bf2e7c169ca42cb4989fc2f8b9 ] Instead of relying on RTNL, ets_dump() can use READ_ONCE() annotations, paired with WRITE_ONCE() ones in ets_change(). Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Stable-dep-of: 87c6efc5ce9c ("net/sched: ets: use old 'nbands' while purging unused classes") Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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committed by
Greg Kroah-Hartman
parent
c2ab3d677f
commit
36b3872a56
@@ -664,7 +664,7 @@ static int ets_qdisc_change(struct Qdisc *sch, struct nlattr *opt,
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sch_tree_lock(sch);
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q->nbands = nbands;
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WRITE_ONCE(q->nbands, nbands);
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for (i = nstrict; i < q->nstrict; i++) {
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if (q->classes[i].qdisc->q.qlen) {
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list_add_tail(&q->classes[i].alist, &q->active);
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@@ -676,11 +676,11 @@ static int ets_qdisc_change(struct Qdisc *sch, struct nlattr *opt,
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list_del_init(&q->classes[i].alist);
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qdisc_purge_queue(q->classes[i].qdisc);
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}
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q->nstrict = nstrict;
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WRITE_ONCE(q->nstrict, nstrict);
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memcpy(q->prio2band, priomap, sizeof(priomap));
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for (i = 0; i < q->nbands; i++)
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q->classes[i].quantum = quanta[i];
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WRITE_ONCE(q->classes[i].quantum, quanta[i]);
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for (i = oldbands; i < q->nbands; i++) {
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q->classes[i].qdisc = queues[i];
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@@ -694,7 +694,7 @@ static int ets_qdisc_change(struct Qdisc *sch, struct nlattr *opt,
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for (i = q->nbands; i < oldbands; i++) {
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qdisc_put(q->classes[i].qdisc);
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q->classes[i].qdisc = NULL;
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q->classes[i].quantum = 0;
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WRITE_ONCE(q->classes[i].quantum, 0);
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q->classes[i].deficit = 0;
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memset(&q->classes[i].bstats, 0, sizeof(q->classes[i].bstats));
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memset(&q->classes[i].qstats, 0, sizeof(q->classes[i].qstats));
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@@ -751,6 +751,7 @@ static int ets_qdisc_dump(struct Qdisc *sch, struct sk_buff *skb)
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struct ets_sched *q = qdisc_priv(sch);
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struct nlattr *opts;
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struct nlattr *nest;
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u8 nbands, nstrict;
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int band;
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int prio;
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int err;
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@@ -763,21 +764,22 @@ static int ets_qdisc_dump(struct Qdisc *sch, struct sk_buff *skb)
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if (!opts)
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goto nla_err;
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if (nla_put_u8(skb, TCA_ETS_NBANDS, q->nbands))
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nbands = READ_ONCE(q->nbands);
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if (nla_put_u8(skb, TCA_ETS_NBANDS, nbands))
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goto nla_err;
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if (q->nstrict &&
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nla_put_u8(skb, TCA_ETS_NSTRICT, q->nstrict))
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nstrict = READ_ONCE(q->nstrict);
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if (nstrict && nla_put_u8(skb, TCA_ETS_NSTRICT, nstrict))
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goto nla_err;
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if (q->nbands > q->nstrict) {
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if (nbands > nstrict) {
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nest = nla_nest_start(skb, TCA_ETS_QUANTA);
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if (!nest)
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goto nla_err;
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for (band = q->nstrict; band < q->nbands; band++) {
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for (band = nstrict; band < nbands; band++) {
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if (nla_put_u32(skb, TCA_ETS_QUANTA_BAND,
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q->classes[band].quantum))
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READ_ONCE(q->classes[band].quantum)))
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goto nla_err;
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}
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@@ -789,7 +791,8 @@ static int ets_qdisc_dump(struct Qdisc *sch, struct sk_buff *skb)
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goto nla_err;
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for (prio = 0; prio <= TC_PRIO_MAX; prio++) {
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if (nla_put_u8(skb, TCA_ETS_PRIOMAP_BAND, q->prio2band[prio]))
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if (nla_put_u8(skb, TCA_ETS_PRIOMAP_BAND,
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READ_ONCE(q->prio2band[prio])))
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goto nla_err;
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}
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