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| author | Pedro Tammela <pctammela@mojatatu.com> | 2023-07-28 17:35:33 +0200 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2023-08-01 10:47:24 +0200 |
| commit | 8798481b667fa7c9bbd5aa843bf1557ada699964 (patch) | |
| tree | 164b3ceb99342adfe3cfa8da837947ccfa784704 /net/sched/sch_hfsc.c | |
| parent | Merge branch 'mptcp-cleanup-and-improvements-in-the-selftests' (diff) | |
| download | linux-8798481b667fa7c9bbd5aa843bf1557ada699964.tar.xz linux-8798481b667fa7c9bbd5aa843bf1557ada699964.zip | |
net/sched: wrap open coded Qdics class filter counter
The 'filter_cnt' counter is used to control a Qdisc class lifetime.
Each filter referecing this class by its id will eventually
increment/decrement this counter in their respective
'add/update/delete' routines.
As these operations are always serialized under rtnl lock, we don't
need an atomic type like 'refcount_t'.
It also means that we lose the overflow/underflow checks already
present in refcount_t, which are valuable to hunt down bugs
where the unsigned counter wraps around as it aids automated tools
like syzkaller to scream in such situations.
Wrap the open coded increment/decrement into helper functions and
add overflow checks to the operations.
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'net/sched/sch_hfsc.c')
| -rw-r--r-- | net/sched/sch_hfsc.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c index 70b0c5873d32..896cb401fdb9 100644 --- a/net/sched/sch_hfsc.c +++ b/net/sched/sch_hfsc.c @@ -116,7 +116,6 @@ struct hfsc_class { struct net_rate_estimator __rcu *rate_est; struct tcf_proto __rcu *filter_list; /* filter list */ struct tcf_block *block; - unsigned int filter_cnt; /* filter count */ unsigned int level; /* class level in hierarchy */ struct hfsc_sched *sched; /* scheduler data */ @@ -1094,7 +1093,8 @@ hfsc_delete_class(struct Qdisc *sch, unsigned long arg, struct hfsc_sched *q = qdisc_priv(sch); struct hfsc_class *cl = (struct hfsc_class *)arg; - if (cl->level > 0 || cl->filter_cnt > 0 || cl == &q->root) + if (cl->level > 0 || qdisc_class_in_use(&cl->cl_common) || + cl == &q->root) return -EBUSY; sch_tree_lock(sch); @@ -1223,7 +1223,7 @@ hfsc_bind_tcf(struct Qdisc *sch, unsigned long parent, u32 classid) if (cl != NULL) { if (p != NULL && p->level <= cl->level) return 0; - cl->filter_cnt++; + qdisc_class_get(&cl->cl_common); } return (unsigned long)cl; @@ -1234,7 +1234,7 @@ hfsc_unbind_tcf(struct Qdisc *sch, unsigned long arg) { struct hfsc_class *cl = (struct hfsc_class *)arg; - cl->filter_cnt--; + qdisc_class_put(&cl->cl_common); } static struct tcf_block *hfsc_tcf_block(struct Qdisc *sch, unsigned long arg, |