diff options
| author | Eric Dumazet <edumazet@google.com> | 2024-04-18 07:32:45 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2024-04-19 11:34:08 +0100 |
| commit | 49e8ae53700212fbb26302df219922752e81fbd2 (patch) | |
| tree | 1f7638a2d70e8686d9a0201ae0dda1ead64342af | |
| parent | 13a9965de32457d59aa3162d657aa4c5e512c146 (diff) | |
| download | mptcp_net-next-49e8ae53700212fbb26302df219922752e81fbd2.tar.gz | |
net_sched: sch_hfsc: implement lockless accesses to q->defcls
Instead of relying on RTNL, hfsc_dump_qdisc() can use READ_ONCE()
annotation, paired with WRITE_ONCE() one in hfsc_change_qdisc().
Use READ_ONCE(q->defcls) in hfsc_classify() to
no longer acquire qdisc lock from hfsc_change_qdisc().
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_hfsc.c | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c index 4e626df742d7a9..c287bf8423b47b 100644 --- a/net/sched/sch_hfsc.c +++ b/net/sched/sch_hfsc.c @@ -1174,7 +1174,8 @@ hfsc_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr) } /* classification failed, try default class */ - cl = hfsc_find_class(TC_H_MAKE(TC_H_MAJ(sch->handle), q->defcls), sch); + cl = hfsc_find_class(TC_H_MAKE(TC_H_MAJ(sch->handle), + READ_ONCE(q->defcls)), sch); if (cl == NULL || cl->level > 0) return NULL; @@ -1443,9 +1444,7 @@ hfsc_change_qdisc(struct Qdisc *sch, struct nlattr *opt, return -EINVAL; qopt = nla_data(opt); - sch_tree_lock(sch); - q->defcls = qopt->defcls; - sch_tree_unlock(sch); + WRITE_ONCE(q->defcls, qopt->defcls); return 0; } @@ -1525,7 +1524,7 @@ hfsc_dump_qdisc(struct Qdisc *sch, struct sk_buff *skb) unsigned char *b = skb_tail_pointer(skb); struct tc_hfsc_qopt qopt; - qopt.defcls = q->defcls; + qopt.defcls = READ_ONCE(q->defcls); if (nla_put(skb, TCA_OPTIONS, sizeof(qopt), &qopt)) goto nla_put_failure; return skb->len; |