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

With help from Chris Wedgwood.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Documentation/feature-removal-schedule.txt

@@ -262,25 +262,6 @@ Who:	Richard Purdie <rpurdie@rpsys.net>
 
 ---------------------------
 
-What:	Multipath cached routing support in ipv4
-When:	in 2.6.23
-Why:	Code was merged, then submitter immediately disappeared leaving
-	us with no maintainer and lots of bugs.  The code should not have
-	been merged in the first place, and many aspects of it's
-	implementation are blocking more critical core networking
-	development.  It's marked EXPERIMENTAL and no distribution
-	enables it because it cause obscure crashes due to unfixable bugs
-	(interfaces don't return errors so memory allocation can't be
-	handled, calling contexts of these interfaces make handling
-	errors impossible too because they get called after we've
-	totally commited to creating a route object, for example).
-	This problem has existed for years and no forward progress
-	has ever been made, and nobody steps up to try and salvage
-	this code, so we're going to finally just get rid of it.
-Who:	David S. Miller <davem@davemloft.net>
-
----------------------------
-
 What:	read_dev_chars(), read_conf_data{,_lpm}() (s390 common I/O layer)
 When:	December 2007
 Why:	These functions are a leftover from 2.4 times. They have several

include/linux/Kbuild

@@ -91,7 +91,6 @@ header-y += in6.h
 header-y += in_route.h
 header-y += ioctl.h
 header-y += ipmi_msgdefs.h
-header-y += ip_mp_alg.h
 header-y += ipsec.h
 header-y += ipx.h
 header-y += irda.h

include/linux/ip_mp_alg.h

-/* ip_mp_alg.h: IPV4 multipath algorithm support, user-visible values.
- *
- * Copyright (C) 2004, 2005 Einar Lueck <elueck@de.ibm.com>
- * Copyright (C) 2005 David S. Miller <davem@davemloft.net>
- */
-
-#ifndef _LINUX_IP_MP_ALG_H
-#define _LINUX_IP_MP_ALG_H
-
-enum ip_mp_alg {
-	IP_MP_ALG_NONE,
-	IP_MP_ALG_RR,
-	IP_MP_ALG_DRR,
-	IP_MP_ALG_RANDOM,
-	IP_MP_ALG_WRANDOM,
-	__IP_MP_ALG_MAX
-};
-
-#define IP_MP_ALG_MAX (__IP_MP_ALG_MAX - 1)
-
-#endif /* _LINUX_IP_MP_ALG_H */
-

include/linux/rtnetlink.h

@@ -261,7 +261,7 @@ enum rtattr_type_t
 	RTA_FLOW,
 	RTA_CACHEINFO,
 	RTA_SESSION,
-	RTA_MP_ALGO,
+	RTA_MP_ALGO, /* no longer used */
 	RTA_TABLE,
 	__RTA_MAX
 };

include/net/dst.h

@@ -47,7 +47,6 @@ struct dst_entry
 #define DST_NOXFRM		2
 #define DST_NOPOLICY		4
 #define DST_NOHASH		8
-#define DST_BALANCED            0x10
 	unsigned long		expires;
 
 	unsigned short		header_len;	/* more space at head required */

include/net/ip_fib.h

@@ -39,7 +39,6 @@ struct fib_config {
 	int			fc_mx_len;
 	int			fc_mp_len;
 	u32			fc_flow;
-	u32			fc_mp_alg;
 	u32			fc_nlflags;
 	struct nl_info		fc_nlinfo;
  };
@@ -85,9 +84,6 @@ struct fib_info {
 	int			fib_nhs;
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 	int			fib_power;
-#endif
-#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
-	u32			fib_mp_alg;
 #endif
 	struct fib_nh		fib_nh[0];
 #define fib_dev		fib_nh[0].nh_dev
@@ -103,10 +99,6 @@ struct fib_result {
 	unsigned char	nh_sel;
 	unsigned char	type;
 	unsigned char	scope;
-#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
-	__be32          network;
-	__be32          netmask;
-#endif
 	struct fib_info *fi;
 #ifdef CONFIG_IP_MULTIPLE_TABLES
 	struct fib_rule	*r;
@@ -145,14 +137,6 @@ struct fib_result_nl {
 #define FIB_RES_DEV(res)		(FIB_RES_NH(res).nh_dev)
 #define FIB_RES_OIF(res)		(FIB_RES_NH(res).nh_oif)
 
-#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
-#define FIB_RES_NETWORK(res)		((res).network)
-#define FIB_RES_NETMASK(res)	        ((res).netmask)
-#else /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
-#define FIB_RES_NETWORK(res)		(0)
-#define FIB_RES_NETMASK(res)	        (0)
-#endif /* CONFIG_IP_ROUTE_MULTIPATH_WRANDOM */
-
 struct fib_table {
 	struct hlist_node tb_hlist;
 	u32		tb_id;

include/net/ip_mp_alg.h

-/* ip_mp_alg.h: IPV4 multipath algorithm support.
- *
- * Copyright (C) 2004, 2005 Einar Lueck <elueck@de.ibm.com>
- * Copyright (C) 2005 David S. Miller <davem@davemloft.net>
- */
-
-#ifndef _NET_IP_MP_ALG_H
-#define _NET_IP_MP_ALG_H
-
-#include <linux/ip_mp_alg.h>
-#include <net/flow.h>
-#include <net/route.h>
-
-struct fib_nh;
-
-struct ip_mp_alg_ops {
-	void	(*mp_alg_select_route)(const struct flowi *flp,
-				       struct rtable *rth, struct rtable **rp);
-	void	(*mp_alg_flush)(void);
-	void	(*mp_alg_set_nhinfo)(__be32 network, __be32 netmask,
-				     unsigned char prefixlen,
-				     const struct fib_nh *nh);
-	void	(*mp_alg_remove)(struct rtable *rth);
-};
-
-extern int multipath_alg_register(struct ip_mp_alg_ops *, enum ip_mp_alg);
-extern void multipath_alg_unregister(struct ip_mp_alg_ops *, enum ip_mp_alg);
-
-extern struct ip_mp_alg_ops *ip_mp_alg_table[];
-
-static inline int multipath_select_route(const struct flowi *flp,
-					 struct rtable *rth,
-					 struct rtable **rp)
-{
-#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
-	struct ip_mp_alg_ops *ops = ip_mp_alg_table[rth->rt_multipath_alg];
-
-	/* mp_alg_select_route _MUST_ be implemented */
-	if (ops && (rth->u.dst.flags & DST_BALANCED)) {
-		ops->mp_alg_select_route(flp, rth, rp);
-		return 1;
-	}
-#endif
-	return 0;
-}
-
-static inline void multipath_flush(void)
-{
-#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
-	int i;
-
-	for (i = IP_MP_ALG_NONE; i <= IP_MP_ALG_MAX; i++) {
-		struct ip_mp_alg_ops *ops = ip_mp_alg_table[i];
-
-		if (ops && ops->mp_alg_flush)
-			ops->mp_alg_flush();
-	}
-#endif
-}
-
-static inline void multipath_set_nhinfo(struct rtable *rth,
-					__be32 network, __be32 netmask,
-					unsigned char prefixlen,
-					const struct fib_nh *nh)
-{
-#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
-	struct ip_mp_alg_ops *ops = ip_mp_alg_table[rth->rt_multipath_alg];
-
-	if (ops && ops->mp_alg_set_nhinfo)
-		ops->mp_alg_set_nhinfo(network, netmask, prefixlen, nh);
-#endif
-}
-
-static inline void multipath_remove(struct rtable *rth)
-{
-#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
-	struct ip_mp_alg_ops *ops = ip_mp_alg_table[rth->rt_multipath_alg];
-
-	if (ops && ops->mp_alg_remove &&
-	    (rth->u.dst.flags & DST_BALANCED))
-		ops->mp_alg_remove(rth);
-#endif
-}
-
-static inline int multipath_comparekeys(const struct flowi *flp1,
-					const struct flowi *flp2)
-{
-	return flp1->fl4_dst == flp2->fl4_dst &&
-		flp1->fl4_src == flp2->fl4_src &&
-		flp1->oif == flp2->oif &&
-		flp1->mark == flp2->mark &&
-		!((flp1->fl4_tos ^ flp2->fl4_tos) &
-		  (IPTOS_RT_MASK | RTO_ONLINK));
-}
-
-#endif /* _NET_IP_MP_ALG_H */

include/net/route.h

@@ -62,7 +62,6 @@ struct rtable
 	
 	unsigned		rt_flags;
 	__u16			rt_type;
-	__u16			rt_multipath_alg;
 
 	__be32			rt_dst;	/* Path destination	*/
 	__be32			rt_src;	/* Path source		*/

net/ipv4/Kconfig

@@ -116,48 +116,6 @@ config IP_ROUTE_MULTIPATH
 	  equal "cost" and chooses one of them in a non-deterministic fashion
 	  if a matching packet arrives.
 
-config IP_ROUTE_MULTIPATH_CACHED
-	bool "IP: equal cost multipath with caching support (EXPERIMENTAL)"
-	depends on IP_ROUTE_MULTIPATH
-	help
-	  Normally, equal cost multipath routing is not supported by the
-	  routing cache. If you say Y here, alternative routes are cached
-	  and on cache lookup a route is chosen in a configurable fashion.
-
-	  If unsure, say N.
-
-config IP_ROUTE_MULTIPATH_RR
-	tristate "MULTIPATH: round robin algorithm"
-	depends on IP_ROUTE_MULTIPATH_CACHED
-	help
-	  Multipath routes are chosen according to Round Robin
-
-config IP_ROUTE_MULTIPATH_RANDOM
-	tristate "MULTIPATH: random algorithm"
-	depends on IP_ROUTE_MULTIPATH_CACHED
-	help
-	  Multipath routes are chosen in a random fashion. Actually,
-	  there is no weight for a route. The advantage of this policy
-	  is that it is implemented stateless and therefore introduces only
-	  a very small delay.
-
-config IP_ROUTE_MULTIPATH_WRANDOM
-	tristate "MULTIPATH: weighted random algorithm"
-	depends on IP_ROUTE_MULTIPATH_CACHED
-	help
-	  Multipath routes are chosen in a weighted random fashion. 
-	  The per route weights are the weights visible via ip route 2. As the
-	  corresponding state management introduces some overhead routing delay
-	  is increased.
-
-config IP_ROUTE_MULTIPATH_DRR
-	tristate "MULTIPATH: interface round robin algorithm"
-	depends on IP_ROUTE_MULTIPATH_CACHED
-	help
-	  Connections are distributed in a round robin fashion over the
-	  available interfaces. This policy makes sense if the connections 
-	  should be primarily distributed on interfaces and not on routes. 
-
 config IP_ROUTE_VERBOSE
 	bool "IP: verbose route monitoring"
 	depends on IP_ADVANCED_ROUTER

net/ipv4/Makefile

@@ -29,14 +29,9 @@ obj-$(CONFIG_INET_TUNNEL) += tunnel4.o
 obj-$(CONFIG_INET_XFRM_MODE_TRANSPORT) += xfrm4_mode_transport.o
 obj-$(CONFIG_INET_XFRM_MODE_TUNNEL) += xfrm4_mode_tunnel.o
 obj-$(CONFIG_IP_PNP) += ipconfig.o
-obj-$(CONFIG_IP_ROUTE_MULTIPATH_RR) += multipath_rr.o
-obj-$(CONFIG_IP_ROUTE_MULTIPATH_RANDOM) += multipath_random.o
-obj-$(CONFIG_IP_ROUTE_MULTIPATH_WRANDOM) += multipath_wrandom.o
-obj-$(CONFIG_IP_ROUTE_MULTIPATH_DRR) += multipath_drr.o
 obj-$(CONFIG_NETFILTER)	+= netfilter.o netfilter/
 obj-$(CONFIG_IP_VS) += ipvs/
 obj-$(CONFIG_INET_DIAG) += inet_diag.o 
-obj-$(CONFIG_IP_ROUTE_MULTIPATH_CACHED) += multipath.o
 obj-$(CONFIG_INET_TCP_DIAG) += tcp_diag.o
 obj-$(CONFIG_NET_TCPPROBE) += tcp_probe.o
 obj-$(CONFIG_TCP_CONG_BIC) += tcp_bic.o

net/ipv4/fib_frontend.c

@@ -453,7 +453,6 @@ const struct nla_policy rtm_ipv4_policy[RTA_MAX+1] = {
 	[RTA_MULTIPATH]		= { .len = sizeof(struct rtnexthop) },
 	[RTA_PROTOINFO]		= { .type = NLA_U32 },
 	[RTA_FLOW]		= { .type = NLA_U32 },
-	[RTA_MP_ALGO]		= { .type = NLA_U32 },
 };
 
 static int rtm_to_fib_config(struct sk_buff *skb, struct nlmsghdr *nlh,
@@ -515,9 +514,6 @@ static int rtm_to_fib_config(struct sk_buff *skb, struct nlmsghdr *nlh,
 		case RTA_FLOW:
 			cfg->fc_flow = nla_get_u32(attr);
 			break;
-		case RTA_MP_ALGO:
-			cfg->fc_mp_alg = nla_get_u32(attr);
-			break;
 		case RTA_TABLE:
 			cfg->fc_table = nla_get_u32(attr);
 			break;

net/ipv4/fib_semantics.c

@@ -42,7 +42,6 @@
 #include <net/tcp.h>
 #include <net/sock.h>
 #include <net/ip_fib.h>
-#include <net/ip_mp_alg.h>
 #include <net/netlink.h>
 #include <net/nexthop.h>
 
@@ -697,13 +696,6 @@ struct fib_info *fib_create_info(struct fib_config *cfg)
 			goto err_inval;
 	}
 #endif
-#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
-	if (cfg->fc_mp_alg) {
-		if (cfg->fc_mp_alg < IP_MP_ALG_NONE ||
-		    cfg->fc_mp_alg > IP_MP_ALG_MAX)
-			goto err_inval;
-	}
-#endif
 
 	err = -ENOBUFS;
 	if (fib_info_cnt >= fib_hash_size) {
@@ -791,10 +783,6 @@ struct fib_info *fib_create_info(struct fib_config *cfg)
 #endif
 	}
 
-#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
-	fi->fib_mp_alg = cfg->fc_mp_alg;
-#endif
-
 	if (fib_props[cfg->fc_type].error) {
 		if (cfg->fc_gw || cfg->fc_oif || cfg->fc_mp)
 			goto err_inval;
@@ -940,10 +928,6 @@ int fib_semantic_match(struct list_head *head, const struct flowi *flp,
 	res->type = fa->fa_type;
 	res->scope = fa->fa_scope;
 	res->fi = fa->fa_info;
-#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
-	res->netmask = mask;
-	res->network = zone & inet_make_mask(prefixlen);
-#endif
 	atomic_inc(&res->fi->fib_clntref);
 	return 0;
 }

net/ipv4/multipath.c

-/* multipath.c: IPV4 multipath algorithm support.
- *
- * Copyright (C) 2004, 2005 Einar Lueck <elueck@de.ibm.com>
- * Copyright (C) 2005 David S. Miller <davem@davemloft.net>
- */
-
-#include <linux/module.h>
-#include <linux/errno.h>
-#include <linux/netdevice.h>
-#include <linux/spinlock.h>
-
-#include <net/ip_mp_alg.h>
-
-static DEFINE_SPINLOCK(alg_table_lock);
-struct ip_mp_alg_ops *ip_mp_alg_table[IP_MP_ALG_MAX + 1];
-
-int multipath_alg_register(struct ip_mp_alg_ops *ops, enum ip_mp_alg n)
-{
-	struct ip_mp_alg_ops **slot;
-	int err;
-
-	if (n < IP_MP_ALG_NONE || n > IP_MP_ALG_MAX ||
-	    !ops->mp_alg_select_route)
-		return -EINVAL;
-
-	spin_lock(&alg_table_lock);
-	slot = &ip_mp_alg_table[n];
-	if (*slot != NULL) {
-		err = -EBUSY;
-	} else {
-		*slot = ops;
-		err = 0;
-	}
-	spin_unlock(&alg_table_lock);
-
-	return err;
-}
-EXPORT_SYMBOL(multipath_alg_register);
-
-void multipath_alg_unregister(struct ip_mp_alg_ops *ops, enum ip_mp_alg n)
-{
-	struct ip_mp_alg_ops **slot;
-
-	if (n < IP_MP_ALG_NONE || n > IP_MP_ALG_MAX)
-		return;
-
-	spin_lock(&alg_table_lock);
-	slot = &ip_mp_alg_table[n];
-	if (*slot == ops)
-		*slot = NULL;
-	spin_unlock(&alg_table_lock);
-
-	synchronize_net();
-}
-EXPORT_SYMBOL(multipath_alg_unregister);

net/ipv4/multipath_drr.c

-/*
- *              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");

net/ipv4/multipath_random.c

-/*
- *              Random policy for multipath.
- *
- *
- * Version:	$Id: multipath_random.c,v 1.1.2.3 2004/09/21 08:42:11 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 <linux/random.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>
-
-#define MULTIPATH_MAX_CANDIDATES 40
-
-static void random_select_route(const struct flowi *flp,
-				struct rtable *first,
-				struct rtable **rp)
-{
-	struct rtable *rt;
-	struct rtable *decision;
-	unsigned char candidate_count = 0;
-
-	/* count all candidate */
-	for (rt = rcu_dereference(first); rt;
-	     rt = rcu_dereference(rt->u.dst.rt_next)) {
-		if ((rt->u.dst.flags & DST_BALANCED) != 0 &&
-		    multipath_comparekeys(&rt->fl, flp))
-			++candidate_count;
-	}
-
-	/* choose a random candidate */
-	decision = first;
-	if (candidate_count > 1) {
-		unsigned char i = 0;
-		unsigned char candidate_no = (unsigned char)
-			(random32() % candidate_count);
-
-		/* find chosen candidate and adjust GC data for all candidates
-		 * to ensure they stay in cache
-		 */
-		for (rt = first; rt; rt = rt->u.dst.rt_next) {
-			if ((rt->u.dst.flags & DST_BALANCED) != 0 &&
-			    multipath_comparekeys(&rt->fl, flp)) {
-				rt->u.dst.lastuse = jiffies;
-
-				if (i == candidate_no)
-					decision = rt;
-
-				if (i >= candidate_count)
-					break;
-
-				i++;
-			}
-		}
-	}
-
-	decision->u.dst.__use++;
-	*rp = decision;
-}
-
-static struct ip_mp_alg_ops random_ops = {
-	.mp_alg_select_route	=	random_select_route,
-};
-
-static int __init random_init(void)
-{
-	return multipath_alg_register(&random_ops, IP_MP_ALG_RANDOM);
-}
-
-static void __exit random_exit(void)
-{
-	multipath_alg_unregister(&random_ops, IP_MP_ALG_RANDOM);
-}
-
-module_init(random_init);
-module_exit(random_exit);
-MODULE_LICENSE("GPL");

net/ipv4/multipath_rr.c

-/*
- *              Round robin policy for multipath.
- *
- *
- * Version:	$Id: multipath_rr.c,v 1.1.2.2 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>
-
-static void rr_select_route(const struct flowi *flp,
-			    struct rtable *first, struct rtable **rp)
-{
-	struct rtable *nh, *result, *min_use_cand = NULL;
-	int min_use = -1;
-
-	/* 1. make sure all alt. nexthops have the same GC related data
-	 * 2. determine the new candidate to be returned
-	 */
-	result = 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)) {
-			nh->u.dst.lastuse = jiffies;
-
-			if (min_use == -1 || nh->u.dst.__use < min_use) {
-				min_use = nh->u.dst.__use;
-				min_use_cand = nh;
-			}
-		}
-	}
-	result = min_use_cand;
-	if (!result)
-		result = first;
-
-	result->u.dst.__use++;
-	*rp = result;
-}
-
-static struct ip_mp_alg_ops rr_ops = {
-	.mp_alg_select_route	=	rr_select_route,
-};
-
-static int __init rr_init(void)
-{
-	return multipath_alg_register(&rr_ops, IP_MP_ALG_RR);
-}
-
-static void __exit rr_exit(void)
-{
-	multipath_alg_unregister(&rr_ops, IP_MP_ALG_RR);
-}
-
-module_init(rr_init);
-module_exit(rr_exit);
-MODULE_LICENSE("GPL");

net/ipv4/multipath_wrandom.c

-/*
- *              Weighted random policy for multipath.
- *
- *
- * Version:	$Id: multipath_wrandom.c,v 1.1.2.3 2004/09/22 07:51:40 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 <linux/random.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_fib.h>
-#include <net/ip_mp_alg.h>
-
-#define MULTIPATH_STATE_SIZE 15
-
-struct multipath_candidate {
-	struct multipath_candidate	*next;
-	int				power;
-	struct rtable			*rt;
-};
-
-struct multipath_dest {
-	struct list_head	list;
-
-	const struct fib_nh	*nh_info;
-	__be32			netmask;
-	__be32			network;
-	unsigned char		prefixlen;
-
-	struct rcu_head		rcu;
-};
-
-struct multipath_bucket {
-	struct list_head	head;
-	spinlock_t		lock;
-};
-
-struct multipath_route {
-	struct list_head	list;
-
-	int			oif;
-	__be32			gw;
-	struct list_head	dests;
-
-	struct rcu_head		rcu;
-};
-
-/* state: primarily weight per route information */
-static struct multipath_bucket state[MULTIPATH_STATE_SIZE];
-
-static unsigned char __multipath_lookup_weight(const struct flowi *fl,
-					       const struct rtable *rt)
-{
-	const int state_idx = rt->idev->dev->ifindex % MULTIPATH_STATE_SIZE;
-	struct multipath_route *r;
-	struct multipath_route *target_route = NULL;
-	struct multipath_dest *d;
-	int weight = 1;
-
-	/* lookup the weight information for a certain route */
-	rcu_read_lock();
-
-	/* find state entry for gateway or add one if necessary */
-	list_for_each_entry_rcu(r, &state[state_idx].head, list) {
-		if (r->gw == rt->rt_gateway &&
-		    r->oif == rt->idev->dev->ifindex) {
-			target_route = r;
-			break;
-		}
-	}
-
-	if (!target_route) {
-		/* this should not happen... but we are prepared */
-		printk( KERN_CRIT"%s: missing state for gateway: %u and " \
-			"device %d\n", __FUNCTION__, rt->rt_gateway,
-			rt->idev->dev->ifindex);
-		goto out;
-	}
-
-	/* find state entry for destination */
-	list_for_each_entry_rcu(d, &target_route->dests, list) {
-		__be32 targetnetwork = fl->fl4_dst &
-			inet_make_mask(d->prefixlen);
-
-		if ((targetnetwork & d->netmask) == d->network) {
-			weight = d->nh_info->nh_weight;
-			goto out;
-		}
-	}
-
-out:
-	rcu_read_unlock();
-	return weight;
-}
-
-static void wrandom_init_state(void)
-{
-	int i;
-
-	for (i = 0; i < MULTIPATH_STATE_SIZE; ++i) {
-		INIT_LIST_HEAD(&state[i].head);
-		spin_lock_init(&state[i].lock);
-	}
-}
-
-static void wrandom_select_route(const struct flowi *flp,
-				 struct rtable *first,
-				 struct rtable **rp)
-{
-	struct rtable *rt;
-	struct rtable *decision;
-	struct multipath_candidate *first_mpc = NULL;
-	struct multipath_candidate *mpc, *last_mpc = NULL;
-	int power = 0;
-	int last_power;
-	int selector;
-	const size_t size_mpc = sizeof(struct multipath_candidate);
-
-	/* collect all candidates and identify their weights */
-	for (rt = rcu_dereference(first); rt;
-	     rt = rcu_dereference(rt->u.dst.rt_next)) {
-		if ((rt->u.dst.flags & DST_BALANCED) != 0 &&
-		    multipath_comparekeys(&rt->fl, flp)) {
-			struct multipath_candidate* mpc =
-				(struct multipath_candidate*)
-				kmalloc(size_mpc, GFP_ATOMIC);
-
-			if (!mpc)
-				return;
-
-			power += __multipath_lookup_weight(flp, rt) * 10000;
-
-			mpc->power = power;
-			mpc->rt = rt;
-			mpc->next = NULL;
-
-			if (!first_mpc)
-				first_mpc = mpc;
-			else
-				last_mpc->next = mpc;
-
-			last_mpc = mpc;
-		}
-	}
-
-	/* choose a weighted random candidate */
-	decision = first;
-	selector = random32() % power;
-	last_power = 0;
-
-	/* select candidate, adjust GC data and cleanup local state */
-	decision = first;
-	last_mpc = NULL;
-	for (mpc = first_mpc; mpc; mpc = mpc->next) {
-		mpc->rt->u.dst.lastuse = jiffies;
-		if (last_power <= selector && selector < mpc->power)
-			decision = mpc->rt;
-
-		last_power = mpc->power;
-		kfree(last_mpc);
-		last_mpc = mpc;
-	}
-
-	/* concurrent __multipath_flush may lead to !last_mpc */
-	kfree(last_mpc);
-
-	decision->u.dst.__use++;
-	*rp = decision;
-}
-
-static void wrandom_set_nhinfo(__be32 network,
-			       __be32 netmask,
-			       unsigned char prefixlen,
-			       const struct fib_nh *nh)
-{
-	const int state_idx = nh->nh_oif % MULTIPATH_STATE_SIZE;
-	struct multipath_route *r, *target_route = NULL;
-	struct multipath_dest *d, *target_dest = NULL;
-
-	/* store the weight information for a certain route */
-	spin_lock_bh(&state[state_idx].lock);
-
-	/* find state entry for gateway or add one if necessary */
-	list_for_each_entry_rcu(r, &state[state_idx].head, list) {
-		if (r->gw == nh->nh_gw && r->oif == nh->nh_oif) {
-			target_route = r;
-			break;
-		}
-	}
-
-	if (!target_route) {
-		const size_t size_rt = sizeof(struct multipath_route);
-		target_route = (struct multipath_route *)
-			kmalloc(size_rt, GFP_ATOMIC);
-
-		target_route->gw = nh->nh_gw;
-		target_route->oif = nh->nh_oif;
-		memset(&target_route->rcu, 0, sizeof(struct rcu_head));
-		INIT_LIST_HEAD(&target_route->dests);
-
-		list_add_rcu(&target_route->list, &state[state_idx].head);
-	}
-
-	/* find state entry for destination or add one if necessary */
-	list_for_each_entry_rcu(d, &target_route->dests, list) {
-		if (d->nh_info == nh) {
-			target_dest = d;
-			break;
-		}
-	}
-
-	if (!target_dest) {
-		const size_t size_dst = sizeof(struct multipath_dest);
-		target_dest = (struct multipath_dest*)
-			kmalloc(size_dst, GFP_ATOMIC);
-
-		target_dest->nh_info = nh;
-		target_dest->network = network;
-		target_dest->netmask = netmask;
-		target_dest->prefixlen = prefixlen;
-		memset(&target_dest->rcu, 0, sizeof(struct rcu_head));
-
-		list_add_rcu(&target_dest->list, &target_route->dests);
-	}
-	/* else: we already stored this info for another destination =>
-	 * we are finished
-	 */
-
-	spin_unlock_bh(&state[state_idx].lock);
-}
-
-static void __multipath_free(struct rcu_head *head)
-{
-	struct multipath_route *rt = container_of(head, struct multipath_route,
-						  rcu);
-	kfree(rt);
-}
-
-static void __multipath_free_dst(struct rcu_head *head)
-{
-	struct multipath_dest *dst = container_of(head,
-						  struct multipath_dest,
-						  rcu);
-	kfree(dst);
-}
-
-static void wrandom_flush(void)
-{
-	int i;
-
-	/* defere delete to all entries */
-	for (i = 0; i < MULTIPATH_STATE_SIZE; ++i) {
-		struct multipath_route *r;
-
-		spin_lock_bh(&state[i].lock);
-		list_for_each_entry_rcu(r, &state[i].head, list) {
-			struct multipath_dest *d;
-			list_for_each_entry_rcu(d, &r->dests, list) {
-				list_del_rcu(&d->list);
-				call_rcu(&d->rcu,
-					 __multipath_free_dst);
-			}
-			list_del_rcu(&r->list);
-			call_rcu(&r->rcu,
-				 __multipath_free);
-		}
-
-		spin_unlock_bh(&state[i].lock);
-	}
-}
-
-static struct ip_mp_alg_ops wrandom_ops = {
-	.mp_alg_select_route	=	wrandom_select_route,
-	.mp_alg_flush		=	wrandom_flush,
-	.mp_alg_set_nhinfo	=	wrandom_set_nhinfo,
-};
-
-static int __init wrandom_init(void)
-{
-	wrandom_init_state();
-
-	return multipath_alg_register(&wrandom_ops, IP_MP_ALG_WRANDOM);
-}
-
-static void __exit wrandom_exit(void)
-{
-	multipath_alg_unregister(&wrandom_ops, IP_MP_ALG_WRANDOM);
-}
-
-module_init(wrandom_init);
-module_exit(wrandom_exit);
-MODULE_LICENSE("GPL");

net/ipv4/route.c

@@ -101,7 +101,6 @@
 #include <net/tcp.h>
 #include <net/icmp.h>
 #include <net/xfrm.h>
-#include <net/ip_mp_alg.h>
 #include <net/netevent.h>
 #include <net/rtnetlink.h>
 #ifdef CONFIG_SYSCTL
@@ -495,13 +494,11 @@ static const struct file_operations rt_cpu_seq_fops = {
 
 static __inline__ void rt_free(struct rtable *rt)
 {
-	multipath_remove(rt);
 	call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
 }
 
 static __inline__ void rt_drop(struct rtable *rt)
 {
-	multipath_remove(rt);
 	ip_rt_put(rt);
 	call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
 }
@@ -574,52 +571,6 @@ static inline int compare_keys(struct flowi *fl1, struct flowi *fl2)
 		(fl1->iif ^ fl2->iif)) == 0;
 }
 
-#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
-static struct rtable **rt_remove_balanced_route(struct rtable **chain_head,
-						struct rtable *expentry,
-						int *removed_count)
-{
-	int passedexpired = 0;
-	struct rtable **nextstep = NULL;
-	struct rtable **rthp = chain_head;
-	struct rtable *rth;
-
-	if (removed_count)
-		*removed_count = 0;
-
-	while ((rth = *rthp) != NULL) {
-		if (rth == expentry)
-			passedexpired = 1;
-
-		if (((*rthp)->u.dst.flags & DST_BALANCED) != 0  &&
-		    compare_keys(&(*rthp)->fl, &expentry->fl)) {
-			if (*rthp == expentry) {
-				*rthp = rth->u.dst.rt_next;
-				continue;
-			} else {
-				*rthp = rth->u.dst.rt_next;
-				rt_free(rth);
-				if (removed_count)
-					++(*removed_count);
-			}
-		} else {
-			if (!((*rthp)->u.dst.flags & DST_BALANCED) &&
-			    passedexpired && !nextstep)
-				nextstep = &rth->u.dst.rt_next;
-
-			rthp = &rth->u.dst.rt_next;
-		}
-	}
-
-	rt_free(expentry);
-	if (removed_count)
-		++(*removed_count);
-
-	return nextstep;
-}
-#endif /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
-
-
 /* This runs via a timer and thus is always in BH context. */
 static void rt_check_expire(unsigned long dummy)
 {
@@ -658,22 +609,8 @@ static void rt_check_expire(unsigned long dummy)
 			}
 
 			/* Cleanup aged off entries. */
-#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
-			/* remove all related balanced entries if necessary */
-			if (rth->u.dst.flags & DST_BALANCED) {
-				rthp = rt_remove_balanced_route(
-					&rt_hash_table[i].chain,
-					rth, NULL);
-				if (!rthp)
-					break;
-			} else {
-				*rthp = rth->u.dst.rt_next;
-				rt_free(rth);
-			}
-#else /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
 			*rthp = rth->u.dst.rt_next;
 			rt_free(rth);
-#endif /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
 		}
 		spin_unlock(rt_hash_lock_addr(i));
 
@@ -721,9 +658,6 @@ void rt_cache_flush(int delay)
 	if (delay < 0)
 		delay = ip_rt_min_delay;
 
-	/* flush existing multipath state*/
-	multipath_flush();
-
 	spin_lock_bh(&rt_flush_lock);
 
 	if (del_timer(&rt_flush_timer) && delay > 0 && rt_deadline) {
@@ -842,30 +776,9 @@ static int rt_garbage_collect(void)
 					rthp = &rth->u.dst.rt_next;
 					continue;
 				}
-#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
-				/* remove all related balanced entries
-				 * if necessary
-				 */
-				if (rth->u.dst.flags & DST_BALANCED) {
-					int r;
-
-					rthp = rt_remove_balanced_route(
-						&rt_hash_table[k].chain,
-						rth,
-						&r);
-					goal -= r;
-					if (!rthp)
-						break;
-				} else {
-					*rthp = rth->u.dst.rt_next;
-					rt_free(rth);
-					goal--;
-				}
-#else /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
 				*rthp = rth->u.dst.rt_next;
 				rt_free(rth);
 				goal--;
-#endif /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
 			}
 			spin_unlock_bh(rt_hash_lock_addr(k));
 			if (goal <= 0)
@@ -939,12 +852,7 @@ static int rt_intern_hash(unsigned hash, struct rtable *rt, struct rtable **rp)
 
 	spin_lock_bh(rt_hash_lock_addr(hash));
 	while ((rth = *rthp) != NULL) {
-#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
-		if (!(rth->u.dst.flags & DST_BALANCED) &&
-		    compare_keys(&rth->fl, &rt->fl)) {
-#else
 		if (compare_keys(&rth->fl, &rt->fl)) {
-#endif
 			/* Put it first */
 			*rthp = rth->u.dst.rt_next;
 			/*
@@ -1774,10 +1682,6 @@ static inline int __mkroute_input(struct sk_buff *skb,
 
 	atomic_set(&rth->u.dst.__refcnt, 1);
 	rth->u.dst.flags= DST_HOST;
-#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
-	if (res->fi->fib_nhs > 1)
-		rth->u.dst.flags |= DST_BALANCED;
-#endif
 	if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
 		rth->u.dst.flags |= DST_NOPOLICY;
 	if (IN_DEV_CONF_GET(out_dev, NOXFRM))
@@ -1812,7 +1716,7 @@ static inline int __mkroute_input(struct sk_buff *skb,
 	return err;
 }
 
-static inline int ip_mkroute_input_def(struct sk_buff *skb,
+static inline int ip_mkroute_input(struct sk_buff *skb,
 				   struct fib_result* res,
 				   const struct flowi *fl,
 				   struct in_device *in_dev,
@@ -1837,63 +1741,6 @@ static inline int ip_mkroute_input_def(struct sk_buff *skb,
 	return rt_intern_hash(hash, rth, (struct rtable**)&skb->dst);
 }
 
-static inline int ip_mkroute_input(struct sk_buff *skb,
-				   struct fib_result* res,
-				   const struct flowi *fl,
-				   struct in_device *in_dev,
-				   __be32 daddr, __be32 saddr, u32 tos)
-{
-#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
-	struct rtable* rth = NULL, *rtres;
-	unsigned char hop, hopcount;
-	int err = -EINVAL;
-	unsigned int hash;
-
-	if (res->fi)
-		hopcount = res->fi->fib_nhs;
-	else
-		hopcount = 1;
-
-	/* distinguish between multipath and singlepath */
-	if (hopcount < 2)
-		return ip_mkroute_input_def(skb, res, fl, in_dev, daddr,
-					    saddr, tos);
-
-	/* add all alternatives to the routing cache */
-	for (hop = 0; hop < hopcount; hop++) {
-		res->nh_sel = hop;
-
-		/* put reference to previous result */
-		if (hop)
-			ip_rt_put(rtres);
-
-		/* create a routing cache entry */
-		err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos,
-				      &rth);
-		if (err)
-			return err;
-
-		/* put it into the cache */
-		hash = rt_hash(daddr, saddr, fl->iif);
-		err = rt_intern_hash(hash, rth, &rtres);
-		if (err)
-			return err;
-
-		/* forward hop information to multipath impl. */
-		multipath_set_nhinfo(rth,
-				     FIB_RES_NETWORK(*res),
-				     FIB_RES_NETMASK(*res),
-				     res->prefixlen,
-				     &FIB_RES_NH(*res));
-	}
-	skb->dst = &rtres->u.dst;
-	return err;
-#else /* CONFIG_IP_ROUTE_MULTIPATH_CACHED  */
-	return ip_mkroute_input_def(skb, res, fl, in_dev, daddr, saddr, tos);
-#endif /* CONFIG_IP_ROUTE_MULTIPATH_CACHED  */
-}
-
-
 /*
  *	NOTE. We drop all the packets that has local source
  *	addresses, because every properly looped back packet
@@ -2211,13 +2058,6 @@ static inline int __mkroute_output(struct rtable **result,
 
 	atomic_set(&rth->u.dst.__refcnt, 1);
 	rth->u.dst.flags= DST_HOST;
-#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
-	if (res->fi) {
-		rth->rt_multipath_alg = res->fi->fib_mp_alg;
-		if (res->fi->fib_nhs > 1)
-			rth->u.dst.flags |= DST_BALANCED;
-	}
-#endif
 	if (IN_DEV_CONF_GET(in_dev, NOXFRM))
 		rth->u.dst.flags |= DST_NOXFRM;
 	if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
@@ -2277,7 +2117,7 @@ static inline int __mkroute_output(struct rtable **result,
 	return err;
 }
 
-static inline int ip_mkroute_output_def(struct rtable **rp,
+static inline int ip_mkroute_output(struct rtable **rp,
 				    struct fib_result* res,
 				    const struct flowi *fl,
 				    const struct flowi *oldflp,
@@ -2295,68 +2135,6 @@ static inline int ip_mkroute_output_def(struct rtable **rp,
 	return err;
 }
 
-static inline int ip_mkroute_output(struct rtable** rp,
-				    struct fib_result* res,
-				    const struct flowi *fl,
-				    const struct flowi *oldflp,
-				    struct net_device *dev_out,
-				    unsigned flags)
-{
-#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
-	unsigned char hop;
-	unsigned hash;
-	int err = -EINVAL;
-	struct rtable *rth = NULL;
-
-	if (res->fi && res->fi->fib_nhs > 1) {
-		unsigned char hopcount = res->fi->fib_nhs;
-
-		for (hop = 0; hop < hopcount; hop++) {
-			struct net_device *dev2nexthop;
-
-			res->nh_sel = hop;
-
-			/* hold a work reference to the output device */
-			dev2nexthop = FIB_RES_DEV(*res);
-			dev_hold(dev2nexthop);
-
-			/* put reference to previous result */
-			if (hop)
-				ip_rt_put(*rp);
-
-			err = __mkroute_output(&rth, res, fl, oldflp,
-					       dev2nexthop, flags);
-
-			if (err != 0)
-				goto cleanup;
-
-			hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src,
-					oldflp->oif);
-			err = rt_intern_hash(hash, rth, rp);
-
-			/* forward hop information to multipath impl. */
-			multipath_set_nhinfo(rth,
-					     FIB_RES_NETWORK(*res),
-					     FIB_RES_NETMASK(*res),
-					     res->prefixlen,
-					     &FIB_RES_NH(*res));
-		cleanup:
-			/* release work reference to output device */
-			dev_put(dev2nexthop);
-
-			if (err != 0)
-				return err;
-		}
-		return err;
-	} else {
-		return ip_mkroute_output_def(rp, res, fl, oldflp, dev_out,
-					     flags);
-	}
-#else /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
-	return ip_mkroute_output_def(rp, res, fl, oldflp, dev_out, flags);
-#endif
-}
-
 /*
  * Major route resolver routine.
  */
@@ -2570,17 +2348,6 @@ int __ip_route_output_key(struct rtable **rp, const struct flowi *flp)
 		    rth->fl.mark == flp->mark &&
 		    !((rth->fl.fl4_tos ^ flp->fl4_tos) &
 			    (IPTOS_RT_MASK | RTO_ONLINK))) {
-
-			/* check for multipath routes and choose one if
-			 * necessary
-			 */
-			if (multipath_select_route(flp, rth, rp)) {
-				dst_hold(&(*rp)->u.dst);
-				RT_CACHE_STAT_INC(out_hit);
-				rcu_read_unlock_bh();
-				return 0;
-			}
-
 			rth->u.dst.lastuse = jiffies;
 			dst_hold(&rth->u.dst);
 			rth->u.dst.__use++;
@@ -2728,10 +2495,6 @@ static int rt_fill_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
 #ifdef CONFIG_NET_CLS_ROUTE
 	if (rt->u.dst.tclassid)
 		NLA_PUT_U32(skb, RTA_FLOW, rt->u.dst.tclassid);
-#endif
-#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
-	if (rt->rt_multipath_alg != IP_MP_ALG_NONE)
-		NLA_PUT_U32(skb, RTA_MP_ALGO, rt->rt_multipath_alg);
 #endif
 	if (rt->fl.iif)
 		NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);