diff options
| author | Eric Dumazet <edumazet@google.com> | 2024-04-18 07:32:48 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2024-04-19 11:34:08 +0100 |
| commit | c85cedb38f41bebc3da08c4a7bc58c5f62a2a950 (patch) | |
| tree | cd123321512e0d1b1f8271e902bd65ce923613e5 | |
| parent | 6c00dc4fdb40fa434cb1271fac3a1201449cb4d3 (diff) | |
| download | net-queue-c85cedb38f41bebc3da08c4a7bc58c5f62a2a950.tar.gz | |
net_sched: sch_skbprio: implement lockless skbprio_dump()
Instead of relying on RTNL, skbprio_dump() can use READ_ONCE()
annotation, paired with WRITE_ONCE() one in skbprio_change().
Also add a READ_ONCE(sch->limit) in skbprio_enqueue().
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/sched/sch_skbprio.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/net/sched/sch_skbprio.c b/net/sched/sch_skbprio.c index b4dd626c309c36..20ff7386b74bd8 100644 --- a/net/sched/sch_skbprio.c +++ b/net/sched/sch_skbprio.c @@ -79,7 +79,9 @@ static int skbprio_enqueue(struct sk_buff *skb, struct Qdisc *sch, prio = min(skb->priority, max_priority); qdisc = &q->qdiscs[prio]; - if (sch->q.qlen < sch->limit) { + + /* sch->limit can change under us from skbprio_change() */ + if (sch->q.qlen < READ_ONCE(sch->limit)) { __skb_queue_tail(qdisc, skb); qdisc_qstats_backlog_inc(sch, skb); q->qstats[prio].backlog += qdisc_pkt_len(skb); @@ -172,7 +174,7 @@ static int skbprio_change(struct Qdisc *sch, struct nlattr *opt, if (opt->nla_len != nla_attr_size(sizeof(*ctl))) return -EINVAL; - sch->limit = ctl->limit; + WRITE_ONCE(sch->limit, ctl->limit); return 0; } @@ -200,7 +202,7 @@ static int skbprio_dump(struct Qdisc *sch, struct sk_buff *skb) { struct tc_skbprio_qopt opt; - opt.limit = sch->limit; + opt.limit = READ_ONCE(sch->limit); if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt)) return -1; |