diff options
| author | Pedro Tammela <pctammela@mojatatu.com> | 2023-07-28 12:35:33 -0300 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2023-08-01 10:47:24 +0200 |
| commit | 8798481b667fa7c9bbd5aa843bf1557ada699964 (patch) | |
| tree | 164b3ceb99342adfe3cfa8da837947ccfa784704 /net/sched/sch_drr.c | |
| parent | 05e1d8bdb276068069d3de65e488700280029e20 (diff) | |
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_drr.c')
| -rw-r--r-- | net/sched/sch_drr.c | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/net/sched/sch_drr.c b/net/sched/sch_drr.c index e35a4e90f4e6..1b22b3b741c9 100644 --- a/net/sched/sch_drr.c +++ b/net/sched/sch_drr.c @@ -17,7 +17,6 @@ struct drr_class { struct Qdisc_class_common common; - unsigned int filter_cnt; struct gnet_stats_basic_sync bstats; struct gnet_stats_queue qstats; @@ -150,7 +149,7 @@ static int drr_delete_class(struct Qdisc *sch, unsigned long arg, struct drr_sched *q = qdisc_priv(sch); struct drr_class *cl = (struct drr_class *)arg; - if (cl->filter_cnt > 0) + if (qdisc_class_in_use(&cl->common)) return -EBUSY; sch_tree_lock(sch); @@ -187,8 +186,8 @@ static unsigned long drr_bind_tcf(struct Qdisc *sch, unsigned long parent, { struct drr_class *cl = drr_find_class(sch, classid); - if (cl != NULL) - cl->filter_cnt++; + if (cl) + qdisc_class_get(&cl->common); return (unsigned long)cl; } @@ -197,7 +196,7 @@ static void drr_unbind_tcf(struct Qdisc *sch, unsigned long arg) { struct drr_class *cl = (struct drr_class *)arg; - cl->filter_cnt--; + qdisc_class_put(&cl->common); } static int drr_graft_class(struct Qdisc *sch, unsigned long arg, |