| Message ID | 20220826011248.323922-1-shaozhengchao@huawei.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next] net: sched: tbf: don't call qdisc_put() while holding tree lock | expand |
On Fri, 26 Aug 2022 09:12:48 +0800 Zhengchao Shao wrote: > The issue is the same to commit c2999f7fb05b ("net: sched: multiq: don't > call qdisc_put() while holding tree lock"). Qdiscs call qdisc_put() while > holding sch tree spinlock, which results sleeping-while-atomic BUG. > > Fixes: c266f64dbfa2 ("net: sched: protect block state with mutex") > Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com> If it's a bug fix for a commit already in Linus's main tree it should come with [PATCH net] in the subject (i.e. without the -next). Please repost.
On 2022/8/26 9:13, Jakub Kicinski wrote: > On Fri, 26 Aug 2022 09:12:48 +0800 Zhengchao Shao wrote: >> The issue is the same to commit c2999f7fb05b ("net: sched: multiq: don't >> call qdisc_put() while holding tree lock"). Qdiscs call qdisc_put() while >> holding sch tree spinlock, which results sleeping-while-atomic BUG. >> >> Fixes: c266f64dbfa2 ("net: sched: protect block state with mutex") >> Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com> > > If it's a bug fix for a commit already in Linus's main tree it should > come with [PATCH net] in the subject (i.e. without the -next). > Please repost. Hi Jakub: Thank you for your reply. I will repost this patch. Zhangchao Shao
diff --git a/net/sched/sch_tbf.c b/net/sched/sch_tbf.c index 72102277449e..36079fdde2cb 100644 --- a/net/sched/sch_tbf.c +++ b/net/sched/sch_tbf.c @@ -356,6 +356,7 @@ static int tbf_change(struct Qdisc *sch, struct nlattr *opt, struct nlattr *tb[TCA_TBF_MAX + 1]; struct tc_tbf_qopt *qopt; struct Qdisc *child = NULL; + struct Qdisc *old = NULL; struct psched_ratecfg rate; struct psched_ratecfg peak; u64 max_size; @@ -447,7 +448,7 @@ static int tbf_change(struct Qdisc *sch, struct nlattr *opt, sch_tree_lock(sch); if (child) { qdisc_tree_flush_backlog(q->qdisc); - qdisc_put(q->qdisc); + old = q->qdisc; q->qdisc = child; } q->limit = qopt->limit; @@ -467,6 +468,7 @@ static int tbf_change(struct Qdisc *sch, struct nlattr *opt, memcpy(&q->peak, &peak, sizeof(struct psched_ratecfg)); sch_tree_unlock(sch); + qdisc_put(old); err = 0; tbf_offload_change(sch);
The issue is the same to commit c2999f7fb05b ("net: sched: multiq: don't call qdisc_put() while holding tree lock"). Qdiscs call qdisc_put() while holding sch tree spinlock, which results sleeping-while-atomic BUG. Fixes: c266f64dbfa2 ("net: sched: protect block state with mutex") Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com> --- net/sched/sch_tbf.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)