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net: sched: set dedicated tcf_walker flag when tp is empty

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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: 8b64678e0a ("net: sched: refactor tp insert/delete for concurrent execution")
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Suggested-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Vlad Buslov 2019-02-25 17:38:31 +02:00 committed by David S. Miller
parent e3af71a36f
commit 6676d5e416
2 changed files with 10 additions and 4 deletions
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1
include/net/pkt_cls.h
View File

@ -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 *);
};

13
net/sched/cls_api.c
View File

@ -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;
}