4 files changed, 66 insertions, 10 deletions

diff --git a/net/sched/Kconfig b/net/sched/Kconfig
index 21f9c7678aa3..2f691fb180d1 100644
--- a/net/sched/Kconfig
+++ b/net/sched/Kconfig
@@ -328,13 +328,16 @@ config NET_CLS_FLOW
           module will be called cls_flow.
 
 config NET_CLS_CGROUP
-        bool "Control Group Classifier"
+        tristate "Control Group Classifier"
         select NET_CLS
         depends on CGROUPS
         ---help---
           Say Y here if you want to classify packets based on the control
           cgroup of their process.
 
+          To compile this code as a module, choose M here: the
+          module will be called cls_cgroup.
+
 config NET_EMATCH
         bool "Extended Matches"
         select NET_CLS
diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c
index e4877ca6727c..7f27d2c15e08 100644
--- a/net/sched/cls_cgroup.c
+++ b/net/sched/cls_cgroup.c
@@ -24,6 +24,25 @@ struct cgroup_cls_state
         u32 classid;
 };
 
+static struct cgroup_subsys_state *cgrp_create(struct cgroup_subsys *ss,
+                                               struct cgroup *cgrp);
+static void cgrp_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp);
+static int cgrp_populate(struct cgroup_subsys *ss, struct cgroup *cgrp);
+
+struct cgroup_subsys net_cls_subsys = {
+        .name           = "net_cls",
+        .create         = cgrp_create,
+        .destroy        = cgrp_destroy,
+        .populate       = cgrp_populate,
+#ifdef CONFIG_NET_CLS_CGROUP
+        .subsys_id      = net_cls_subsys_id,
+#else
+#define net_cls_subsys_id net_cls_subsys.subsys_id
+#endif
+        .module         = THIS_MODULE,
+};
+
+
 static inline struct cgroup_cls_state *cgrp_cls_state(struct cgroup *cgrp)
 {
         return container_of(cgroup_subsys_state(cgrp, net_cls_subsys_id),
@@ -79,14 +98,6 @@ static int cgrp_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)
         return cgroup_add_files(cgrp, ss, ss_files, ARRAY_SIZE(ss_files));
 }
 
-struct cgroup_subsys net_cls_subsys = {
-        .name           = "net_cls",
-        .create         = cgrp_create,
-        .destroy        = cgrp_destroy,
-        .populate       = cgrp_populate,
-        .subsys_id      = net_cls_subsys_id,
-};
-
 struct cls_cgroup_head
 {
         u32                     handle;
@@ -277,12 +288,19 @@ static struct tcf_proto_ops cls_cgroup_ops __read_mostly = {
 
 static int __init init_cgroup_cls(void)
 {
-        return register_tcf_proto_ops(&cls_cgroup_ops);
+        int ret = register_tcf_proto_ops(&cls_cgroup_ops);
+        if (ret)
+                return ret;
+        ret = cgroup_load_subsys(&net_cls_subsys);
+        if (ret)
+                unregister_tcf_proto_ops(&cls_cgroup_ops);
+        return ret;
 }
 
 static void __exit exit_cgroup_cls(void)
 {
         unregister_tcf_proto_ops(&cls_cgroup_ops);
+        cgroup_unload_subsys(&net_cls_subsys);
 }
 
 module_init(init_cgroup_cls);
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 75fd1c672c61..6cd491013b50 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -1707,6 +1707,7 @@ static int __init pktsched_init(void)
 {
         register_qdisc(&pfifo_qdisc_ops);
         register_qdisc(&bfifo_qdisc_ops);
+        register_qdisc(&pfifo_head_drop_qdisc_ops);
         register_qdisc(&mq_qdisc_ops);
         proc_net_fops_create(&init_net, "psched", 0, &psched_fops);
 
diff --git a/net/sched/sch_fifo.c b/net/sched/sch_fifo.c
index 69188e8358b4..4b0a6cc44c77 100644
--- a/net/sched/sch_fifo.c
+++ b/net/sched/sch_fifo.c
@@ -43,6 +43,26 @@ static int pfifo_enqueue(struct sk_buff *skb, struct Qdisc* sch)
         return qdisc_reshape_fail(skb, sch);
 }
 
+static int pfifo_tail_enqueue(struct sk_buff *skb, struct Qdisc* sch)
+{
+        struct sk_buff *skb_head;
+        struct fifo_sched_data *q = qdisc_priv(sch);
+
+        if (likely(skb_queue_len(&sch->q) < q->limit))
+                return qdisc_enqueue_tail(skb, sch);
+
+        /* queue full, remove one skb to fulfill the limit */
+        skb_head = qdisc_dequeue_head(sch);
+        sch->bstats.bytes -= qdisc_pkt_len(skb_head);
+        sch->bstats.packets--;
+        sch->qstats.drops++;
+        kfree_skb(skb_head);
+
+        qdisc_enqueue_tail(skb, sch);
+
+        return NET_XMIT_CN;
+}
+
 static int fifo_init(struct Qdisc *sch, struct nlattr *opt)
 {
         struct fifo_sched_data *q = qdisc_priv(sch);
@@ -108,6 +128,20 @@ struct Qdisc_ops bfifo_qdisc_ops __read_mostly = {
 };
 EXPORT_SYMBOL(bfifo_qdisc_ops);
 
+struct Qdisc_ops pfifo_head_drop_qdisc_ops __read_mostly = {
+        .id             =       "pfifo_head_drop",
+        .priv_size      =       sizeof(struct fifo_sched_data),
+        .enqueue        =       pfifo_tail_enqueue,
+        .dequeue        =       qdisc_dequeue_head,
+        .peek           =       qdisc_peek_head,
+        .drop           =       qdisc_queue_drop_head,
+        .init           =       fifo_init,
+        .reset          =       qdisc_reset_queue,
+        .change         =       fifo_init,
+        .dump           =       fifo_dump,
+        .owner          =       THIS_MODULE,
+};
+
 /* Pass size change message down to embedded FIFO */
 int fifo_set_limit(struct Qdisc *q, unsigned int limit)
 {