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!

1 files changed, 609 insertions, 0 deletions

diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
new file mode 100644
index 000000000000..8c01e023f02e
--- /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);