[IPV4]: The scheduled removal of multipath cached routing support.

With help from Chris Wedgwood.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 0 insertions, 249 deletions

diff --git a/net/ipv4/multipath_drr.c b/net/ipv4/multipath_drr.c
deleted file mode 100644
index b03c5ca2c823..000000000000
--- a/net/ipv4/multipath_drr.c
+++ /dev/null
@@ -1,249 +0,0 @@
-/*
- *              Device round robin policy for multipath.
- *
- *
- * Version:	$Id: multipath_drr.c,v 1.1.2.1 2004/09/16 07:42:34 elueck Exp $
- *
- * Authors:	Einar Lueck <elueck@de.ibm.com><lkml@einar-lueck.de>
- *
- *		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.
- */
-
-#include <asm/system.h>
-#include <asm/uaccess.h>
-#include <linux/types.h>
-#include <linux/errno.h>
-#include <linux/timer.h>
-#include <linux/mm.h>
-#include <linux/kernel.h>
-#include <linux/fcntl.h>
-#include <linux/stat.h>
-#include <linux/socket.h>
-#include <linux/in.h>
-#include <linux/inet.h>
-#include <linux/netdevice.h>
-#include <linux/inetdevice.h>
-#include <linux/igmp.h>
-#include <linux/proc_fs.h>
-#include <linux/seq_file.h>
-#include <linux/module.h>
-#include <linux/mroute.h>
-#include <linux/init.h>
-#include <net/ip.h>
-#include <net/protocol.h>
-#include <linux/skbuff.h>
-#include <net/sock.h>
-#include <net/icmp.h>
-#include <net/udp.h>
-#include <net/raw.h>
-#include <linux/notifier.h>
-#include <linux/if_arp.h>
-#include <linux/netfilter_ipv4.h>
-#include <net/ipip.h>
-#include <net/checksum.h>
-#include <net/ip_mp_alg.h>
-
-struct multipath_device {
-	int		ifi; /* interface index of device */
-	atomic_t	usecount;
-	int 		allocated;
-};
-
-#define MULTIPATH_MAX_DEVICECANDIDATES 10
-
-static struct multipath_device state[MULTIPATH_MAX_DEVICECANDIDATES];
-static DEFINE_SPINLOCK(state_lock);
-
-static int inline __multipath_findslot(void)
-{
-	int i;
-
-	for (i = 0; i < MULTIPATH_MAX_DEVICECANDIDATES; i++) {
-		if (state[i].allocated == 0)
-			return i;
-	}
-	return -1;
-}
-
-static int inline __multipath_finddev(int ifindex)
-{
-	int i;
-
-	for (i = 0; i < MULTIPATH_MAX_DEVICECANDIDATES; i++) {
-		if (state[i].allocated != 0 &&
-		    state[i].ifi == ifindex)
-			return i;
-	}
-	return -1;
-}
-
-static int drr_dev_event(struct notifier_block *this,
-			 unsigned long event, void *ptr)
-{
-	struct net_device *dev = ptr;
-	int devidx;
-
-	switch (event) {
-	case NETDEV_UNREGISTER:
-	case NETDEV_DOWN:
-		spin_lock_bh(&state_lock);
-
-		devidx = __multipath_finddev(dev->ifindex);
-		if (devidx != -1) {
-			state[devidx].allocated = 0;
-			state[devidx].ifi = 0;
-			atomic_set(&state[devidx].usecount, 0);
-		}
-
-		spin_unlock_bh(&state_lock);
-		break;
-	}
-
-	return NOTIFY_DONE;
-}
-
-static struct notifier_block drr_dev_notifier = {
-	.notifier_call	= drr_dev_event,
-};
-
-
-static void drr_safe_inc(atomic_t *usecount)
-{
-	int n;
-
-	atomic_inc(usecount);
-
-	n = atomic_read(usecount);
-	if (n <= 0) {
-		int i;
-
-		spin_lock_bh(&state_lock);
-
-		for (i = 0; i < MULTIPATH_MAX_DEVICECANDIDATES; i++)
-			atomic_set(&state[i].usecount, 0);
-
-		spin_unlock_bh(&state_lock);
-	}
-}
-
-static void drr_select_route(const struct flowi *flp,
-			     struct rtable *first, struct rtable **rp)
-{
-	struct rtable *nh, *result, *cur_min;
-	int min_usecount = -1;
-	int devidx = -1;
-	int cur_min_devidx = -1;
-
-	/* 1. make sure all alt. nexthops have the same GC related data */
-	/* 2. determine the new candidate to be returned */
-	result = NULL;
-	cur_min = NULL;
-	for (nh = rcu_dereference(first); nh;
-	     nh = rcu_dereference(nh->u.dst.rt_next)) {
-		if ((nh->u.dst.flags & DST_BALANCED) != 0 &&
-		    multipath_comparekeys(&nh->fl, flp)) {
-			int nh_ifidx = nh->u.dst.dev->ifindex;
-
-			nh->u.dst.lastuse = jiffies;
-			nh->u.dst.__use++;
-			if (result != NULL)
-				continue;
-
-			/* search for the output interface */
-
-			/* this is not SMP safe, only add/remove are
-			 * SMP safe as wrong usecount updates have no big
-			 * impact
-			 */
-			devidx = __multipath_finddev(nh_ifidx);
-			if (devidx == -1) {
-				/* add the interface to the array
-				 * SMP safe
-				 */
-				spin_lock_bh(&state_lock);
-
-				/* due to SMP: search again */
-				devidx = __multipath_finddev(nh_ifidx);
-				if (devidx == -1) {
-					/* add entry for device */
-					devidx = __multipath_findslot();
-					if (devidx == -1) {
-						/* unlikely but possible */
-						continue;
-					}
-
-					state[devidx].allocated = 1;
-					state[devidx].ifi = nh_ifidx;
-					atomic_set(&state[devidx].usecount, 0);
-					min_usecount = 0;
-				}
-
-				spin_unlock_bh(&state_lock);
-			}
-
-			if (min_usecount == 0) {
-				/* if the device has not been used it is
-				 * the primary target
-				 */
-				drr_safe_inc(&state[devidx].usecount);
-				result = nh;
-			} else {
-				int count =
-					atomic_read(&state[devidx].usecount);
-
-				if (min_usecount == -1 ||
-				    count < min_usecount) {
-					cur_min = nh;
-					cur_min_devidx = devidx;
-					min_usecount = count;
-				}
-			}
-		}
-	}
-
-	if (!result) {
-		if (cur_min) {
-			drr_safe_inc(&state[cur_min_devidx].usecount);
-			result = cur_min;
-		} else {
-			result = first;
-		}
-	}
-
-	*rp = result;
-}
-
-static struct ip_mp_alg_ops drr_ops = {
-	.mp_alg_select_route	=	drr_select_route,
-};
-
-static int __init drr_init(void)
-{
-	int err = register_netdevice_notifier(&drr_dev_notifier);
-
-	if (err)
-		return err;
-
-	err = multipath_alg_register(&drr_ops, IP_MP_ALG_DRR);
-	if (err)
-		goto fail;
-
-	return 0;
-
-fail:
-	unregister_netdevice_notifier(&drr_dev_notifier);
-	return err;
-}
-
-static void __exit drr_exit(void)
-{
-	unregister_netdevice_notifier(&drr_dev_notifier);
-	multipath_alg_unregister(&drr_ops, IP_MP_ALG_DRR);
-}
-
-module_init(drr_init);
-module_exit(drr_exit);
-MODULE_LICENSE("GPL");