From 6676d5e416eecaf4e823a2c3903aa132ffc2ede0 Mon Sep 17 00:00:00 2001 From: Vlad Buslov Date: Mon, 25 Feb 2019 17:38:31 +0200 Subject: net: sched: set dedicated tcf_walker flag when tp is empty Using tcf_walker->stop flag to determine when tcf_walker->fn() was called at least once is unreliable. Some classifiers set 'stop' flag on error before calling walker callback, other classifiers used to call it with NULL filter pointer when empty. In order to prevent further regressions, extend tcf_walker structure with dedicated 'nonempty' flag. Set this flag in tcf_walker->fn() implementation that is used to check if classifier has filters configured. Fixes: 8b64678e0af8 ("net: sched: refactor tp insert/delete for concurrent execution") Signed-off-by: Vlad Buslov Suggested-by: Cong Wang Signed-off-by: David S. Miller --- include/net/pkt_cls.h | 1 + net/sched/cls_api.c | 13 +++++++++---- 2 files changed, 10 insertions(+), 4 deletions(-) diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h index 58ea48e1221c..d5e7a1af346f 100644 --- a/include/net/pkt_cls.h +++ b/include/net/pkt_cls.h @@ -17,6 +17,7 @@ struct tcf_walker { int stop; int skip; int count; + bool nonempty; unsigned long cookie; int (*fn)(struct tcf_proto *, void *node, struct tcf_walker *); }; diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c index 6593c245f714..97d9312c2ff9 100644 --- a/net/sched/cls_api.c +++ b/net/sched/cls_api.c @@ -238,18 +238,23 @@ static void tcf_proto_put(struct tcf_proto *tp, bool rtnl_held, tcf_proto_destroy(tp, rtnl_held, extack); } -static int walker_noop(struct tcf_proto *tp, void *d, struct tcf_walker *arg) +static int walker_check_empty(struct tcf_proto *tp, void *d, + struct tcf_walker *arg) { - return -1; + if (tp) { + arg->nonempty = true; + return -1; + } + return 0; } static bool tcf_proto_is_empty(struct tcf_proto *tp, bool rtnl_held) { - struct tcf_walker walker = { .fn = walker_noop, }; + struct tcf_walker walker = { .fn = walker_check_empty, }; if (tp->ops->walk) { tp->ops->walk(tp, &walker, rtnl_held); - return !walker.stop; + return !walker.nonempty; } return true; } -- cgit v1.2.3-59-g8ed1b