diff options
Diffstat (limited to 'net/ipv4/multipath_drr.c')
| -rw-r--r-- | net/ipv4/multipath_drr.c | 249 |
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 b03c5ca2c82..00000000000 --- 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"); |