Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
new file mode 100644
index 0000000..8c01e02
--- /dev/null
+++ b/net/sched/sch_generic.c
@@ -0,0 +1,609 @@
+/*
+ * net/sched/sch_generic.c Generic packet scheduler routines.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ * Jamal Hadi Salim, <hadi@cyberus.ca> 990601
+ * - Ingress support
+ */
+
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <linux/bitops.h>
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/in.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/rtnetlink.h>
+#include <linux/init.h>
+#include <linux/rcupdate.h>
+#include <linux/list.h>
+#include <net/sock.h>
+#include <net/pkt_sched.h>
+
+/* Main transmission queue. */
+
+/* Main qdisc structure lock.
+
+ However, modifications
+ to data, participating in scheduling must be additionally
+ protected with dev->queue_lock spinlock.
+
+ The idea is the following:
+ - enqueue, dequeue are serialized via top level device
+ spinlock dev->queue_lock.
+ - tree walking is protected by read_lock_bh(qdisc_tree_lock)
+ and this lock is used only in process context.
+ - updates to tree are made under rtnl semaphore or
+ from softirq context (__qdisc_destroy rcu-callback)
+ hence this lock needs local bh disabling.
+
+ qdisc_tree_lock must be grabbed BEFORE dev->queue_lock!
+ */
+DEFINE_RWLOCK(qdisc_tree_lock);
+
+void qdisc_lock_tree(struct net_device *dev)
+{
+ write_lock_bh(&qdisc_tree_lock);
+ spin_lock_bh(&dev->queue_lock);
+}
+
+void qdisc_unlock_tree(struct net_device *dev)
+{
+ spin_unlock_bh(&dev->queue_lock);
+ write_unlock_bh(&qdisc_tree_lock);
+}
+
+/*
+ dev->queue_lock serializes queue accesses for this device
+ AND dev->qdisc pointer itself.
+
+ dev->xmit_lock serializes accesses to device driver.
+
+ dev->queue_lock and dev->xmit_lock are mutually exclusive,
+ if one is grabbed, another must be free.
+ */
+
+
+/* Kick device.
+ Note, that this procedure can be called by a watchdog timer, so that
+ we do not check dev->tbusy flag here.
+
+ Returns: 0 - queue is empty.
+ >0 - queue is not empty, but throttled.
+ <0 - queue is not empty. Device is throttled, if dev->tbusy != 0.
+
+ NOTE: Called under dev->queue_lock with locally disabled BH.
+*/
+
+int qdisc_restart(struct net_device *dev)
+{
+ struct Qdisc *q = dev->qdisc;
+ struct sk_buff *skb;
+
+ /* Dequeue packet */
+ if ((skb = q->dequeue(q)) != NULL) {
+ unsigned nolock = (dev->features & NETIF_F_LLTX);
+ /*
+ * When the driver has LLTX set it does its own locking
+ * in start_xmit. No need to add additional overhead by
+ * locking again. These checks are worth it because
+ * even uncongested locks can be quite expensive.
+ * The driver can do trylock like here too, in case
+ * of lock congestion it should return -1 and the packet
+ * will be requeued.
+ */
+ if (!nolock) {
+ if (!spin_trylock(&dev->xmit_lock)) {
+ collision:
+ /* So, someone grabbed the driver. */
+
+ /* It may be transient configuration error,
+ when hard_start_xmit() recurses. We detect
+ it by checking xmit owner and drop the
+ packet when deadloop is detected.
+ */
+ if (dev->xmit_lock_owner == smp_processor_id()) {
+ kfree_skb(skb);
+ if (net_ratelimit())
+ printk(KERN_DEBUG "Dead loop on netdevice %s, fix it urgently!\n", dev->name);
+ return -1;
+ }
+ __get_cpu_var(netdev_rx_stat).cpu_collision++;
+ goto requeue;
+ }
+ /* Remember that the driver is grabbed by us. */
+ dev->xmit_lock_owner = smp_processor_id();
+ }
+
+ {
+ /* And release queue */
+ spin_unlock(&dev->queue_lock);
+
+ if (!netif_queue_stopped(dev)) {
+ int ret;
+ if (netdev_nit)
+ dev_queue_xmit_nit(skb, dev);
+
+ ret = dev->hard_start_xmit(skb, dev);
+ if (ret == NETDEV_TX_OK) {
+ if (!nolock) {
+ dev->xmit_lock_owner = -1;
+ spin_unlock(&dev->xmit_lock);
+ }
+ spin_lock(&dev->queue_lock);
+ return -1;
+ }
+ if (ret == NETDEV_TX_LOCKED && nolock) {
+ spin_lock(&dev->queue_lock);
+ goto collision;
+ }
+ }
+
+ /* NETDEV_TX_BUSY - we need to requeue */
+ /* Release the driver */
+ if (!nolock) {
+ dev->xmit_lock_owner = -1;
+ spin_unlock(&dev->xmit_lock);
+ }
+ spin_lock(&dev->queue_lock);
+ q = dev->qdisc;
+ }
+
+ /* Device kicked us out :(
+ This is possible in three cases:
+
+ 0. driver is locked
+ 1. fastroute is enabled
+ 2. device cannot determine busy state
+ before start of transmission (f.e. dialout)
+ 3. device is buggy (ppp)
+ */
+
+requeue:
+ q->ops->requeue(skb, q);
+ netif_schedule(dev);
+ return 1;
+ }
+ return q->q.qlen;
+}
+
+static void dev_watchdog(unsigned long arg)
+{
+ struct net_device *dev = (struct net_device *)arg;
+
+ spin_lock(&dev->xmit_lock);
+ if (dev->qdisc != &noop_qdisc) {
+ if (netif_device_present(dev) &&
+ netif_running(dev) &&
+ netif_carrier_ok(dev)) {
+ if (netif_queue_stopped(dev) &&
+ (jiffies - dev->trans_start) > dev->watchdog_timeo) {
+ printk(KERN_INFO "NETDEV WATCHDOG: %s: transmit timed out\n", dev->name);
+ dev->tx_timeout(dev);
+ }
+ if (!mod_timer(&dev->watchdog_timer, jiffies + dev->watchdog_timeo))
+ dev_hold(dev);
+ }
+ }
+ spin_unlock(&dev->xmit_lock);
+
+ dev_put(dev);
+}
+
+static void dev_watchdog_init(struct net_device *dev)
+{
+ init_timer(&dev->watchdog_timer);
+ dev->watchdog_timer.data = (unsigned long)dev;
+ dev->watchdog_timer.function = dev_watchdog;
+}
+
+void __netdev_watchdog_up(struct net_device *dev)
+{
+ if (dev->tx_timeout) {
+ if (dev->watchdog_timeo <= 0)
+ dev->watchdog_timeo = 5*HZ;
+ if (!mod_timer(&dev->watchdog_timer, jiffies + dev->watchdog_timeo))
+ dev_hold(dev);
+ }
+}
+
+static void dev_watchdog_up(struct net_device *dev)
+{
+ spin_lock_bh(&dev->xmit_lock);
+ __netdev_watchdog_up(dev);
+ spin_unlock_bh(&dev->xmit_lock);
+}
+
+static void dev_watchdog_down(struct net_device *dev)
+{
+ spin_lock_bh(&dev->xmit_lock);
+ if (del_timer(&dev->watchdog_timer))
+ __dev_put(dev);
+ spin_unlock_bh(&dev->xmit_lock);
+}
+
+/* "NOOP" scheduler: the best scheduler, recommended for all interfaces
+ under all circumstances. It is difficult to invent anything faster or
+ cheaper.
+ */
+
+static int
+noop_enqueue(struct sk_buff *skb, struct Qdisc * qdisc)
+{
+ kfree_skb(skb);
+ return NET_XMIT_CN;
+}
+
+static struct sk_buff *
+noop_dequeue(struct Qdisc * qdisc)
+{
+ return NULL;
+}
+
+static int
+noop_requeue(struct sk_buff *skb, struct Qdisc* qdisc)
+{
+ if (net_ratelimit())
+ printk(KERN_DEBUG "%s deferred output. It is buggy.\n", skb->dev->name);
+ kfree_skb(skb);
+ return NET_XMIT_CN;
+}
+
+struct Qdisc_ops noop_qdisc_ops = {
+ .next = NULL,
+ .cl_ops = NULL,
+ .id = "noop",
+ .priv_size = 0,
+ .enqueue = noop_enqueue,
+ .dequeue = noop_dequeue,
+ .requeue = noop_requeue,
+ .owner = THIS_MODULE,
+};
+
+struct Qdisc noop_qdisc = {
+ .enqueue = noop_enqueue,
+ .dequeue = noop_dequeue,
+ .flags = TCQ_F_BUILTIN,
+ .ops = &noop_qdisc_ops,
+ .list = LIST_HEAD_INIT(noop_qdisc.list),
+};
+
+static struct Qdisc_ops noqueue_qdisc_ops = {
+ .next = NULL,
+ .cl_ops = NULL,
+ .id = "noqueue",
+ .priv_size = 0,
+ .enqueue = noop_enqueue,
+ .dequeue = noop_dequeue,
+ .requeue = noop_requeue,
+ .owner = THIS_MODULE,
+};
+
+static struct Qdisc noqueue_qdisc = {
+ .enqueue = NULL,
+ .dequeue = noop_dequeue,
+ .flags = TCQ_F_BUILTIN,
+ .ops = &noqueue_qdisc_ops,
+ .list = LIST_HEAD_INIT(noqueue_qdisc.list),
+};
+
+
+static const u8 prio2band[TC_PRIO_MAX+1] =
+ { 1, 2, 2, 2, 1, 2, 0, 0 , 1, 1, 1, 1, 1, 1, 1, 1 };
+
+/* 3-band FIFO queue: old style, but should be a bit faster than
+ generic prio+fifo combination.
+ */
+
+static int
+pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc* qdisc)
+{
+ struct sk_buff_head *list = qdisc_priv(qdisc);
+
+ list += prio2band[skb->priority&TC_PRIO_MAX];
+
+ if (list->qlen < qdisc->dev->tx_queue_len) {
+ __skb_queue_tail(list, skb);
+ qdisc->q.qlen++;
+ qdisc->bstats.bytes += skb->len;
+ qdisc->bstats.packets++;
+ return 0;
+ }
+ qdisc->qstats.drops++;
+ kfree_skb(skb);
+ return NET_XMIT_DROP;
+}
+
+static struct sk_buff *
+pfifo_fast_dequeue(struct Qdisc* qdisc)
+{
+ int prio;
+ struct sk_buff_head *list = qdisc_priv(qdisc);
+ struct sk_buff *skb;
+
+ for (prio = 0; prio < 3; prio++, list++) {
+ skb = __skb_dequeue(list);
+ if (skb) {
+ qdisc->q.qlen--;
+ return skb;
+ }
+ }
+ return NULL;
+}
+
+static int
+pfifo_fast_requeue(struct sk_buff *skb, struct Qdisc* qdisc)
+{
+ struct sk_buff_head *list = qdisc_priv(qdisc);
+
+ list += prio2band[skb->priority&TC_PRIO_MAX];
+
+ __skb_queue_head(list, skb);
+ qdisc->q.qlen++;
+ qdisc->qstats.requeues++;
+ return 0;
+}
+
+static void
+pfifo_fast_reset(struct Qdisc* qdisc)
+{
+ int prio;
+ struct sk_buff_head *list = qdisc_priv(qdisc);
+
+ for (prio=0; prio < 3; prio++)
+ skb_queue_purge(list+prio);
+ qdisc->q.qlen = 0;
+}
+
+static int pfifo_fast_dump(struct Qdisc *qdisc, struct sk_buff *skb)
+{
+ unsigned char *b = skb->tail;
+ struct tc_prio_qopt opt;
+
+ opt.bands = 3;
+ memcpy(&opt.priomap, prio2band, TC_PRIO_MAX+1);
+ RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
+ return skb->len;
+
+rtattr_failure:
+ skb_trim(skb, b - skb->data);
+ return -1;
+}
+
+static int pfifo_fast_init(struct Qdisc *qdisc, struct rtattr *opt)
+{
+ int i;
+ struct sk_buff_head *list = qdisc_priv(qdisc);
+
+ for (i=0; i<3; i++)
+ skb_queue_head_init(list+i);
+
+ return 0;
+}
+
+static struct Qdisc_ops pfifo_fast_ops = {
+ .next = NULL,
+ .cl_ops = NULL,
+ .id = "pfifo_fast",
+ .priv_size = 3 * sizeof(struct sk_buff_head),
+ .enqueue = pfifo_fast_enqueue,
+ .dequeue = pfifo_fast_dequeue,
+ .requeue = pfifo_fast_requeue,
+ .init = pfifo_fast_init,
+ .reset = pfifo_fast_reset,
+ .dump = pfifo_fast_dump,
+ .owner = THIS_MODULE,
+};
+
+struct Qdisc * qdisc_create_dflt(struct net_device *dev, struct Qdisc_ops *ops)
+{
+ void *p;
+ struct Qdisc *sch;
+ int size;
+
+ /* ensure that the Qdisc and the private data are 32-byte aligned */
+ size = ((sizeof(*sch) + QDISC_ALIGN_CONST) & ~QDISC_ALIGN_CONST);
+ size += ops->priv_size + QDISC_ALIGN_CONST;
+
+ p = kmalloc(size, GFP_KERNEL);
+ if (!p)
+ return NULL;
+ memset(p, 0, size);
+
+ sch = (struct Qdisc *)(((unsigned long)p + QDISC_ALIGN_CONST)
+ & ~QDISC_ALIGN_CONST);
+ sch->padded = (char *)sch - (char *)p;
+
+ INIT_LIST_HEAD(&sch->list);
+ skb_queue_head_init(&sch->q);
+ sch->ops = ops;
+ sch->enqueue = ops->enqueue;
+ sch->dequeue = ops->dequeue;
+ sch->dev = dev;
+ dev_hold(dev);
+ sch->stats_lock = &dev->queue_lock;
+ atomic_set(&sch->refcnt, 1);
+ if (!ops->init || ops->init(sch, NULL) == 0)
+ return sch;
+
+ dev_put(dev);
+ kfree(p);
+ return NULL;
+}
+
+/* Under dev->queue_lock and BH! */
+
+void qdisc_reset(struct Qdisc *qdisc)
+{
+ struct Qdisc_ops *ops = qdisc->ops;
+
+ if (ops->reset)
+ ops->reset(qdisc);
+}
+
+/* this is the rcu callback function to clean up a qdisc when there
+ * are no further references to it */
+
+static void __qdisc_destroy(struct rcu_head *head)
+{
+ struct Qdisc *qdisc = container_of(head, struct Qdisc, q_rcu);
+ struct Qdisc_ops *ops = qdisc->ops;
+
+#ifdef CONFIG_NET_ESTIMATOR
+ gen_kill_estimator(&qdisc->bstats, &qdisc->rate_est);
+#endif
+ write_lock(&qdisc_tree_lock);
+ if (ops->reset)
+ ops->reset(qdisc);
+ if (ops->destroy)
+ ops->destroy(qdisc);
+ write_unlock(&qdisc_tree_lock);
+ module_put(ops->owner);
+
+ dev_put(qdisc->dev);
+ kfree((char *) qdisc - qdisc->padded);
+}
+
+/* Under dev->queue_lock and BH! */
+
+void qdisc_destroy(struct Qdisc *qdisc)
+{
+ struct list_head cql = LIST_HEAD_INIT(cql);
+ struct Qdisc *cq, *q, *n;
+
+ if (qdisc->flags & TCQ_F_BUILTIN ||
+ !atomic_dec_and_test(&qdisc->refcnt))
+ return;
+
+ if (!list_empty(&qdisc->list)) {
+ if (qdisc->ops->cl_ops == NULL)
+ list_del(&qdisc->list);
+ else
+ list_move(&qdisc->list, &cql);
+ }
+
+ /* unlink inner qdiscs from dev->qdisc_list immediately */
+ list_for_each_entry(cq, &cql, list)
+ list_for_each_entry_safe(q, n, &qdisc->dev->qdisc_list, list)
+ if (TC_H_MAJ(q->parent) == TC_H_MAJ(cq->handle)) {
+ if (q->ops->cl_ops == NULL)
+ list_del_init(&q->list);
+ else
+ list_move_tail(&q->list, &cql);
+ }
+ list_for_each_entry_safe(cq, n, &cql, list)
+ list_del_init(&cq->list);
+
+ call_rcu(&qdisc->q_rcu, __qdisc_destroy);
+}
+
+void dev_activate(struct net_device *dev)
+{
+ /* No queueing discipline is attached to device;
+ create default one i.e. pfifo_fast for devices,
+ which need queueing and noqueue_qdisc for
+ virtual interfaces
+ */
+
+ if (dev->qdisc_sleeping == &noop_qdisc) {
+ struct Qdisc *qdisc;
+ if (dev->tx_queue_len) {
+ qdisc = qdisc_create_dflt(dev, &pfifo_fast_ops);
+ if (qdisc == NULL) {
+ printk(KERN_INFO "%s: activation failed\n", dev->name);
+ return;
+ }
+ write_lock_bh(&qdisc_tree_lock);
+ list_add_tail(&qdisc->list, &dev->qdisc_list);
+ write_unlock_bh(&qdisc_tree_lock);
+ } else {
+ qdisc = &noqueue_qdisc;
+ }
+ write_lock_bh(&qdisc_tree_lock);
+ dev->qdisc_sleeping = qdisc;
+ write_unlock_bh(&qdisc_tree_lock);
+ }
+
+ spin_lock_bh(&dev->queue_lock);
+ rcu_assign_pointer(dev->qdisc, dev->qdisc_sleeping);
+ if (dev->qdisc != &noqueue_qdisc) {
+ dev->trans_start = jiffies;
+ dev_watchdog_up(dev);
+ }
+ spin_unlock_bh(&dev->queue_lock);
+}
+
+void dev_deactivate(struct net_device *dev)
+{
+ struct Qdisc *qdisc;
+
+ spin_lock_bh(&dev->queue_lock);
+ qdisc = dev->qdisc;
+ dev->qdisc = &noop_qdisc;
+
+ qdisc_reset(qdisc);
+
+ spin_unlock_bh(&dev->queue_lock);
+
+ dev_watchdog_down(dev);
+
+ while (test_bit(__LINK_STATE_SCHED, &dev->state))
+ yield();
+
+ spin_unlock_wait(&dev->xmit_lock);
+}
+
+void dev_init_scheduler(struct net_device *dev)
+{
+ qdisc_lock_tree(dev);
+ dev->qdisc = &noop_qdisc;
+ dev->qdisc_sleeping = &noop_qdisc;
+ INIT_LIST_HEAD(&dev->qdisc_list);
+ qdisc_unlock_tree(dev);
+
+ dev_watchdog_init(dev);
+}
+
+void dev_shutdown(struct net_device *dev)
+{
+ struct Qdisc *qdisc;
+
+ qdisc_lock_tree(dev);
+ qdisc = dev->qdisc_sleeping;
+ dev->qdisc = &noop_qdisc;
+ dev->qdisc_sleeping = &noop_qdisc;
+ qdisc_destroy(qdisc);
+#if defined(CONFIG_NET_SCH_INGRESS) || defined(CONFIG_NET_SCH_INGRESS_MODULE)
+ if ((qdisc = dev->qdisc_ingress) != NULL) {
+ dev->qdisc_ingress = NULL;
+ qdisc_destroy(qdisc);
+ }
+#endif
+ BUG_TRAP(!timer_pending(&dev->watchdog_timer));
+ qdisc_unlock_tree(dev);
+}
+
+EXPORT_SYMBOL(__netdev_watchdog_up);
+EXPORT_SYMBOL(noop_qdisc);
+EXPORT_SYMBOL(noop_qdisc_ops);
+EXPORT_SYMBOL(qdisc_create_dflt);
+EXPORT_SYMBOL(qdisc_destroy);
+EXPORT_SYMBOL(qdisc_reset);
+EXPORT_SYMBOL(qdisc_restart);
+EXPORT_SYMBOL(qdisc_lock_tree);
+EXPORT_SYMBOL(qdisc_unlock_tree);