net/sched: Export mq functions for reuse

To enable the cake_mq qdisc to reuse code from the mq qdisc, export a
bunch of functions from sch_mq. Split common functionality out from some
functions so it can be composed with other code, and export other
functions wholesale. To discourage wanton reuse, put the symbols into a
new NET_SCHED_INTERNAL namespace, and a sch_priv.h header file.

No functional change intended.

Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20260109-mq-cake-sub-qdisc-v8-1-8d613fece5d8@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/MAINTAINERS b/MAINTAINERS
index 6348b87b7600e50603338e000f3cb6421b816231..6a0635fe11f983c1993ed3a58e267be9d3e8406d 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -25454,6 +25454,7 @@ L:      netdev@vger.kernel.org
 S:     Maintained
 F:     include/net/pkt_cls.h
 F:     include/net/pkt_sched.h
+F:     include/net/sch_priv.h
 F:     include/net/tc_act/
 F:     include/uapi/linux/pkt_cls.h
 F:     include/uapi/linux/pkt_sched.h

diff --git a/include/net/sch_priv.h b/include/net/sch_priv.h
new file mode 100644 (file)
index 0000000..4789f66
--- /dev/null
+++ b/include/net/sch_priv.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __NET_SCHED_PRIV_H
+#define __NET_SCHED_PRIV_H
+
+#include <net/sch_generic.h>
+
+struct mq_sched {
+       struct Qdisc            **qdiscs;
+};
+
+int mq_init_common(struct Qdisc *sch, struct nlattr *opt,
+                  struct netlink_ext_ack *extack,
+                  const struct Qdisc_ops *qdisc_ops);
+void mq_destroy_common(struct Qdisc *sch);
+void mq_attach(struct Qdisc *sch);
+void mq_dump_common(struct Qdisc *sch, struct sk_buff *skb);
+struct netdev_queue *mq_select_queue(struct Qdisc *sch,
+                                    struct tcmsg *tcm);
+struct Qdisc *mq_leaf(struct Qdisc *sch, unsigned long cl);
+unsigned long mq_find(struct Qdisc *sch, u32 classid);
+int mq_dump_class(struct Qdisc *sch, unsigned long cl,
+                 struct sk_buff *skb, struct tcmsg *tcm);
+int mq_dump_class_stats(struct Qdisc *sch, unsigned long cl,
+                       struct gnet_dump *d);
+void mq_walk(struct Qdisc *sch, struct qdisc_walker *arg);
+
+#endif

diff --git a/net/sched/sch_mq.c b/net/sched/sch_mq.c
index c860119a8f091c68c64932dee48465f4bca6f901..bb94cd577943a429231debdab5d74c983e3a8fe9 100644 (file)
--- a/net/sched/sch_mq.c
+++ b/net/sched/sch_mq.c
@@ -15,11 +15,7 @@
 #include <net/netlink.h>
 #include <net/pkt_cls.h>
 #include <net/pkt_sched.h>
-#include <net/sch_generic.h>
-
-struct mq_sched {
-       struct Qdisc            **qdiscs;
-};
+#include <net/sch_priv.h>
 
 static int mq_offload(struct Qdisc *sch, enum tc_mq_command cmd)
 {
@@ -49,23 +45,29 @@ static int mq_offload_stats(struct Qdisc *sch)
        return qdisc_offload_dump_helper(sch, TC_SETUP_QDISC_MQ, &opt);
 }
 
-static void mq_destroy(struct Qdisc *sch)
+void mq_destroy_common(struct Qdisc *sch)
 {
        struct net_device *dev = qdisc_dev(sch);
        struct mq_sched *priv = qdisc_priv(sch);
        unsigned int ntx;
 
-       mq_offload(sch, TC_MQ_DESTROY);
-
        if (!priv->qdiscs)
                return;
        for (ntx = 0; ntx < dev->num_tx_queues && priv->qdiscs[ntx]; ntx++)
                qdisc_put(priv->qdiscs[ntx]);
        kfree(priv->qdiscs);
 }
+EXPORT_SYMBOL_NS_GPL(mq_destroy_common, "NET_SCHED_INTERNAL");
 
-static int mq_init(struct Qdisc *sch, struct nlattr *opt,
-                  struct netlink_ext_ack *extack)
+static void mq_destroy(struct Qdisc *sch)
+{
+       mq_offload(sch, TC_MQ_DESTROY);
+       mq_destroy_common(sch);
+}
+
+int mq_init_common(struct Qdisc *sch, struct nlattr *opt,
+                  struct netlink_ext_ack *extack,
+                  const struct Qdisc_ops *qdisc_ops)
 {
        struct net_device *dev = qdisc_dev(sch);
        struct mq_sched *priv = qdisc_priv(sch);
@@ -87,7 +89,8 @@ static int mq_init(struct Qdisc *sch, struct nlattr *opt,
 
        for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
                dev_queue = netdev_get_tx_queue(dev, ntx);
-               qdisc = qdisc_create_dflt(dev_queue, get_default_qdisc_ops(dev, ntx),
+               qdisc = qdisc_create_dflt(dev_queue,
+                                         qdisc_ops ?: get_default_qdisc_ops(dev, ntx),
                                          TC_H_MAKE(TC_H_MAJ(sch->handle),
                                                    TC_H_MIN(ntx + 1)),
                                          extack);
@@ -98,12 +101,24 @@ static int mq_init(struct Qdisc *sch, struct nlattr *opt,
        }
 
        sch->flags |= TCQ_F_MQROOT;
+       return 0;
+}
+EXPORT_SYMBOL_NS_GPL(mq_init_common, "NET_SCHED_INTERNAL");
+
+static int mq_init(struct Qdisc *sch, struct nlattr *opt,
+                  struct netlink_ext_ack *extack)
+{
+       int ret;
+
+       ret = mq_init_common(sch, opt, extack, NULL);
+       if (ret)
+               return ret;
 
        mq_offload(sch, TC_MQ_CREATE);
        return 0;
 }
 
-static void mq_attach(struct Qdisc *sch)
+void mq_attach(struct Qdisc *sch)
 {
        struct net_device *dev = qdisc_dev(sch);
        struct mq_sched *priv = qdisc_priv(sch);
@@ -124,8 +139,9 @@ static void mq_attach(struct Qdisc *sch)
        kfree(priv->qdiscs);
        priv->qdiscs = NULL;
 }
+EXPORT_SYMBOL_NS_GPL(mq_attach, "NET_SCHED_INTERNAL");
 
-static int mq_dump(struct Qdisc *sch, struct sk_buff *skb)
+void mq_dump_common(struct Qdisc *sch, struct sk_buff *skb)
 {
        struct net_device *dev = qdisc_dev(sch);
        struct Qdisc *qdisc;
@@ -152,7 +168,12 @@ static int mq_dump(struct Qdisc *sch, struct sk_buff *skb)
 
                spin_unlock_bh(qdisc_lock(qdisc));
        }
+}
+EXPORT_SYMBOL_NS_GPL(mq_dump_common, "NET_SCHED_INTERNAL");
 
+static int mq_dump(struct Qdisc *sch, struct sk_buff *skb)
+{
+       mq_dump_common(sch, skb);
        return mq_offload_stats(sch);
 }
 
@@ -166,11 +187,12 @@ static struct netdev_queue *mq_queue_get(struct Qdisc *sch, unsigned long cl)
        return netdev_get_tx_queue(dev, ntx);
 }
 
-static struct netdev_queue *mq_select_queue(struct Qdisc *sch,
-                                           struct tcmsg *tcm)
+struct netdev_queue *mq_select_queue(struct Qdisc *sch,
+                                    struct tcmsg *tcm)
 {
        return mq_queue_get(sch, TC_H_MIN(tcm->tcm_parent));
 }
+EXPORT_SYMBOL_NS_GPL(mq_select_queue, "NET_SCHED_INTERNAL");
 
 static int mq_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new,
                    struct Qdisc **old, struct netlink_ext_ack *extack)
@@ -198,14 +220,15 @@ static int mq_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new,
        return 0;
 }
 
-static struct Qdisc *mq_leaf(struct Qdisc *sch, unsigned long cl)
+struct Qdisc *mq_leaf(struct Qdisc *sch, unsigned long cl)
 {
        struct netdev_queue *dev_queue = mq_queue_get(sch, cl);
 
        return rtnl_dereference(dev_queue->qdisc_sleeping);
 }
+EXPORT_SYMBOL_NS_GPL(mq_leaf, "NET_SCHED_INTERNAL");
 
-static unsigned long mq_find(struct Qdisc *sch, u32 classid)
+unsigned long mq_find(struct Qdisc *sch, u32 classid)
 {
        unsigned int ntx = TC_H_MIN(classid);
 
@@ -213,9 +236,10 @@ static unsigned long mq_find(struct Qdisc *sch, u32 classid)
                return 0;
        return ntx;
 }
+EXPORT_SYMBOL_NS_GPL(mq_find, "NET_SCHED_INTERNAL");
 
-static int mq_dump_class(struct Qdisc *sch, unsigned long cl,
-                        struct sk_buff *skb, struct tcmsg *tcm)
+int mq_dump_class(struct Qdisc *sch, unsigned long cl,
+                 struct sk_buff *skb, struct tcmsg *tcm)
 {
        struct netdev_queue *dev_queue = mq_queue_get(sch, cl);
 
@@ -224,9 +248,10 @@ static int mq_dump_class(struct Qdisc *sch, unsigned long cl,
        tcm->tcm_info = rtnl_dereference(dev_queue->qdisc_sleeping)->handle;
        return 0;
 }
+EXPORT_SYMBOL_NS_GPL(mq_dump_class, "NET_SCHED_INTERNAL");
 
-static int mq_dump_class_stats(struct Qdisc *sch, unsigned long cl,
-                              struct gnet_dump *d)
+int mq_dump_class_stats(struct Qdisc *sch, unsigned long cl,
+                       struct gnet_dump *d)
 {
        struct netdev_queue *dev_queue = mq_queue_get(sch, cl);
 
@@ -236,8 +261,9 @@ static int mq_dump_class_stats(struct Qdisc *sch, unsigned long cl,
                return -1;
        return 0;
 }
+EXPORT_SYMBOL_NS_GPL(mq_dump_class_stats, "NET_SCHED_INTERNAL");
 
-static void mq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
+void mq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 {
        struct net_device *dev = qdisc_dev(sch);
        unsigned int ntx;
@@ -251,6 +277,7 @@ static void mq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
                        break;
        }
 }
+EXPORT_SYMBOL_NS_GPL(mq_walk, "NET_SCHED_INTERNAL");
 
 static const struct Qdisc_class_ops mq_class_ops = {
        .select_queue   = mq_select_queue,