net: sched: remove redundant NULL check in change hook function

Currently, the change function can be called by two ways. The one way is
that qdisc_change() will call it. Before calling change function,
qdisc_change() ensures tca[TCA_OPTIONS] is not empty. The other way is
that .init() will call it. The opt parameter is also checked before
calling change function in .init(). Therefore, it's no need to check the
input parameter opt in change function.

Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Link: https://lore.kernel.org/r/20220829071219.208646-1-shaozhengchao@huawei.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

13 files changed, 1 insertions, 39 deletions

diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index a43a58a73d09..36acc95d611e 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -2569,9 +2569,6 @@ static int cake_change(struct Qdisc *sch, struct nlattr *opt,
 	struct nlattr *tb[TCA_CAKE_MAX + 1];
 	int err;
 
-	if (!opt)
-		return -EINVAL;
-
 	err = nla_parse_nested_deprecated(tb, TCA_CAKE_MAX, opt, cake_policy,
 					  extack);
 	if (err < 0)
diff --git a/net/sched/sch_codel.c b/net/sched/sch_codel.c
index 30169b3adbbb..d7a4874543de 100644
--- a/net/sched/sch_codel.c
+++ b/net/sched/sch_codel.c
@@ -138,9 +138,6 @@ static int codel_change(struct Qdisc *sch, struct nlattr *opt,
 	unsigned int qlen, dropped = 0;
 	int err;
 
-	if (!opt)
-		return -EINVAL;
-
 	err = nla_parse_nested_deprecated(tb, TCA_CODEL_MAX, opt,
 					  codel_policy, NULL);
 	if (err < 0)
diff --git a/net/sched/sch_ets.c b/net/sched/sch_ets.c
index 8de4365886e8..a3aea22ef09d 100644
--- a/net/sched/sch_ets.c
+++ b/net/sched/sch_ets.c
@@ -594,11 +594,6 @@ static int ets_qdisc_change(struct Qdisc *sch, struct nlattr *opt,
 	unsigned int i;
 	int err;
 
-	if (!opt) {
-		NL_SET_ERR_MSG(extack, "ETS options are required for this operation");
-		return -EINVAL;
-	}
-
 	err = nla_parse_nested(tb, TCA_ETS_MAX, opt, ets_policy, extack);
 	if (err < 0)
 		return err;
diff --git a/net/sched/sch_fq.c b/net/sched/sch_fq.c
index 2fb76fc0cc31..48d14fb90ba0 100644
--- a/net/sched/sch_fq.c
+++ b/net/sched/sch_fq.c
@@ -808,9 +808,6 @@ static int fq_change(struct Qdisc *sch, struct nlattr *opt,
 	unsigned drop_len = 0;
 	u32 fq_log;
 
-	if (!opt)
-		return -EINVAL;
-
 	err = nla_parse_nested_deprecated(tb, TCA_FQ_MAX, opt, fq_policy,
 					  NULL);
 	if (err < 0)
diff --git a/net/sched/sch_fq_codel.c b/net/sched/sch_fq_codel.c
index 23a042adb74d..f16f471daa81 100644
--- a/net/sched/sch_fq_codel.c
+++ b/net/sched/sch_fq_codel.c
@@ -372,9 +372,6 @@ static int fq_codel_change(struct Qdisc *sch, struct nlattr *opt,
 	u32 quantum = 0;
 	int err;
 
-	if (!opt)
-		return -EINVAL;
-
 	err = nla_parse_nested_deprecated(tb, TCA_FQ_CODEL_MAX, opt,
 					  fq_codel_policy, NULL);
 	if (err < 0)
diff --git a/net/sched/sch_fq_pie.c b/net/sched/sch_fq_pie.c
index 35c35465226b..6980796d435d 100644
--- a/net/sched/sch_fq_pie.c
+++ b/net/sched/sch_fq_pie.c
@@ -283,9 +283,6 @@ static int fq_pie_change(struct Qdisc *sch, struct nlattr *opt,
 	unsigned int num_dropped = 0;
 	int err;
 
-	if (!opt)
-		return -EINVAL;
-
 	err = nla_parse_nested(tb, TCA_FQ_PIE_MAX, opt, fq_pie_policy, extack);
 	if (err < 0)
 		return err;
diff --git a/net/sched/sch_gred.c b/net/sched/sch_gred.c
index e7af53f607bb..44af3b18eed9 100644
--- a/net/sched/sch_gred.c
+++ b/net/sched/sch_gred.c
@@ -648,9 +648,6 @@ static int gred_change(struct Qdisc *sch, struct nlattr *opt,
 	u32 max_P;
 	struct gred_sched_data *prealloc;
 
-	if (opt == NULL)
-		return -EINVAL;
-
 	err = nla_parse_nested_deprecated(tb, TCA_GRED_MAX, opt, gred_policy,
 					  extack);
 	if (err < 0)
diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c
index 03efc40e42fc..c8bef923c79c 100644
--- a/net/sched/sch_hfsc.c
+++ b/net/sched/sch_hfsc.c
@@ -1430,7 +1430,7 @@ hfsc_change_qdisc(struct Qdisc *sch, struct nlattr *opt,
 	struct hfsc_sched *q = qdisc_priv(sch);
 	struct tc_hfsc_qopt *qopt;
 
-	if (opt == NULL || nla_len(opt) < sizeof(*qopt))
+	if (nla_len(opt) < sizeof(*qopt))
 		return -EINVAL;
 	qopt = nla_data(opt);
 
diff --git a/net/sched/sch_hhf.c b/net/sched/sch_hhf.c
index 420ede875322..d26cd436cbe3 100644
--- a/net/sched/sch_hhf.c
+++ b/net/sched/sch_hhf.c
@@ -516,9 +516,6 @@ static int hhf_change(struct Qdisc *sch, struct nlattr *opt,
 	u32 new_quantum = q->quantum;
 	u32 new_hhf_non_hh_weight = q->hhf_non_hh_weight;
 
-	if (!opt)
-		return -EINVAL;
-
 	err = nla_parse_nested_deprecated(tb, TCA_HHF_MAX, opt, hhf_policy,
 					  NULL);
 	if (err < 0)
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index 5449ed114e40..b70ac04110dd 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -961,9 +961,6 @@ static int netem_change(struct Qdisc *sch, struct nlattr *opt,
 	int old_loss_model = CLG_RANDOM;
 	int ret;
 
-	if (opt == NULL)
-		return -EINVAL;
-
 	qopt = nla_data(opt);
 	ret = parse_attr(tb, TCA_NETEM_MAX, opt, netem_policy, sizeof(*qopt));
 	if (ret < 0)
diff --git a/net/sched/sch_pie.c b/net/sched/sch_pie.c
index 5a457ff61acd..974038ba6c7b 100644
--- a/net/sched/sch_pie.c
+++ b/net/sched/sch_pie.c
@@ -143,9 +143,6 @@ static int pie_change(struct Qdisc *sch, struct nlattr *opt,
 	unsigned int qlen, dropped = 0;
 	int err;
 
-	if (!opt)
-		return -EINVAL;
-
 	err = nla_parse_nested_deprecated(tb, TCA_PIE_MAX, opt, pie_policy,
 					  NULL);
 	if (err < 0)
diff --git a/net/sched/sch_plug.c b/net/sched/sch_plug.c
index cbc2ebca4548..ea8c4a7174bb 100644
--- a/net/sched/sch_plug.c
+++ b/net/sched/sch_plug.c
@@ -161,9 +161,6 @@ static int plug_change(struct Qdisc *sch, struct nlattr *opt,
 	struct plug_sched_data *q = qdisc_priv(sch);
 	struct tc_plug_qopt *msg;
 
-	if (opt == NULL)
-		return -EINVAL;
-
 	msg = nla_data(opt);
 	if (nla_len(opt) < sizeof(*msg))
 		return -EINVAL;
diff --git a/net/sched/sch_red.c b/net/sched/sch_red.c
index f7ac40c0335e..4952406f70b9 100644
--- a/net/sched/sch_red.c
+++ b/net/sched/sch_red.c
@@ -368,9 +368,6 @@ static int red_change(struct Qdisc *sch, struct nlattr *opt,
 	struct nlattr *tb[TCA_RED_MAX + 1];
 	int err;
 
-	if (!opt)
-		return -EINVAL;
-
 	err = nla_parse_nested_deprecated(tb, TCA_RED_MAX, opt, red_policy,
 					  extack);
 	if (err < 0)