diff options
| author | Eric Dumazet <edumazet@google.com> | 2024-04-18 07:32:42 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2024-04-19 11:34:07 +0100 |
| commit | 01daf66b791e1ddd1a4aae2a65ea65fa1d4a96ef (patch) | |
| tree | 8649e339c08c3443377e9e6f249bde23f8732167 /net/sched | |
| parent | c5f1dde7f731e7bf2e7c169ca42cb4989fc2f8b9 (diff) | |
net_sched: sch_fifo: implement lockless __fifo_dump()
Instead of relying on RTNL, __fifo_dump() can use READ_ONCE()
annotations, paired with WRITE_ONCE() ones in __fifo_init().
Also add missing READ_ONCE(sh->limit) in bfifo_enqueue(),
pfifo_enqueue() and pfifo_tail_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>
Diffstat (limited to 'net/sched')
| -rw-r--r-- | net/sched/sch_fifo.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/net/sched/sch_fifo.c b/net/sched/sch_fifo.c index 450f5c67ac49..b50b2c2cc09b 100644 --- a/net/sched/sch_fifo.c +++ b/net/sched/sch_fifo.c @@ -19,7 +19,8 @@ static int bfifo_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free) { - if (likely(sch->qstats.backlog + qdisc_pkt_len(skb) <= sch->limit)) + if (likely(sch->qstats.backlog + qdisc_pkt_len(skb) <= + READ_ONCE(sch->limit))) return qdisc_enqueue_tail(skb, sch); return qdisc_drop(skb, sch, to_free); @@ -28,7 +29,7 @@ static int bfifo_enqueue(struct sk_buff *skb, struct Qdisc *sch, static int pfifo_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free) { - if (likely(sch->q.qlen < sch->limit)) + if (likely(sch->q.qlen < READ_ONCE(sch->limit))) return qdisc_enqueue_tail(skb, sch); return qdisc_drop(skb, sch, to_free); @@ -39,7 +40,7 @@ static int pfifo_tail_enqueue(struct sk_buff *skb, struct Qdisc *sch, { unsigned int prev_backlog; - if (likely(sch->q.qlen < sch->limit)) + if (likely(sch->q.qlen < READ_ONCE(sch->limit))) return qdisc_enqueue_tail(skb, sch); prev_backlog = sch->qstats.backlog; @@ -105,14 +106,14 @@ static int __fifo_init(struct Qdisc *sch, struct nlattr *opt, if (is_bfifo) limit *= psched_mtu(qdisc_dev(sch)); - sch->limit = limit; + WRITE_ONCE(sch->limit, limit); } else { struct tc_fifo_qopt *ctl = nla_data(opt); if (nla_len(opt) < sizeof(*ctl)) return -EINVAL; - sch->limit = ctl->limit; + WRITE_ONCE(sch->limit, ctl->limit); } if (is_bfifo) @@ -154,7 +155,7 @@ static void fifo_destroy(struct Qdisc *sch) static int __fifo_dump(struct Qdisc *sch, struct sk_buff *skb) { - struct tc_fifo_qopt opt = { .limit = sch->limit }; + struct tc_fifo_qopt opt = { .limit = READ_ONCE(sch->limit) }; if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt)) goto nla_put_failure; |