Linux-2.6.12-rc2v2.6.12-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, 888 insertions, 0 deletions

diff --git a/net/ipv4/ipvs/ip_vs_lblcr.c b/net/ipv4/ipvs/ip_vs_lblcr.c
new file mode 100644
index 000000000000..22b5dd55d271
--- /dev/null
+++ b/net/ipv4/ipvs/ip_vs_lblcr.c
@@ -0,0 +1,888 @@
+/*
+ * IPVS:        Locality-Based Least-Connection with Replication scheduler
+ *
+ * Version:     $Id: ip_vs_lblcr.c,v 1.11 2002/09/15 08:14:08 wensong Exp $
+ *
+ * Authors:     Wensong Zhang <wensong@gnuchina.org>
+ *
+ *              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.
+ *
+ * Changes:
+ *     Julian Anastasov        :    Added the missing (dest->weight>0)
+ *                                  condition in the ip_vs_dest_set_max.
+ *
+ */
+
+/*
+ * The lblc/r algorithm is as follows (pseudo code):
+ *
+ *       if serverSet[dest_ip] is null then
+ *               n, serverSet[dest_ip] <- {weighted least-conn node};
+ *       else
+ *               n <- {least-conn (alive) node in serverSet[dest_ip]};
+ *               if (n is null) OR
+ *                  (n.conns>n.weight AND
+ *                   there is a node m with m.conns<m.weight/2) then
+ *                   n <- {weighted least-conn node};
+ *                   add n to serverSet[dest_ip];
+ *               if |serverSet[dest_ip]| > 1 AND
+ *                   now - serverSet[dest_ip].lastMod > T then
+ *                   m <- {most conn node in serverSet[dest_ip]};
+ *                   remove m from serverSet[dest_ip];
+ *       if serverSet[dest_ip] changed then
+ *               serverSet[dest_ip].lastMod <- now;
+ *
+ *       return n;
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+
+/* for sysctl */
+#include <linux/fs.h>
+#include <linux/sysctl.h>
+/* for proc_net_create/proc_net_remove */
+#include <linux/proc_fs.h>
+
+#include <net/ip_vs.h>
+
+
+/*
+ *    It is for garbage collection of stale IPVS lblcr entries,
+ *    when the table is full.
+ */
+#define CHECK_EXPIRE_INTERVAL   (60*HZ)
+#define ENTRY_TIMEOUT           (6*60*HZ)
+
+/*
+ *    It is for full expiration check.
+ *    When there is no partial expiration check (garbage collection)
+ *    in a half hour, do a full expiration check to collect stale
+ *    entries that haven't been touched for a day.
+ */
+#define COUNT_FOR_FULL_EXPIRATION   30
+static int sysctl_ip_vs_lblcr_expiration = 24*60*60*HZ;
+
+
+/*
+ *     for IPVS lblcr entry hash table
+ */
+#ifndef CONFIG_IP_VS_LBLCR_TAB_BITS
+#define CONFIG_IP_VS_LBLCR_TAB_BITS      10
+#endif
+#define IP_VS_LBLCR_TAB_BITS     CONFIG_IP_VS_LBLCR_TAB_BITS
+#define IP_VS_LBLCR_TAB_SIZE     (1 << IP_VS_LBLCR_TAB_BITS)
+#define IP_VS_LBLCR_TAB_MASK     (IP_VS_LBLCR_TAB_SIZE - 1)
+
+
+/*
+ *      IPVS destination set structure and operations
+ */
+struct ip_vs_dest_list {
+        struct ip_vs_dest_list  *next;          /* list link */
+        struct ip_vs_dest       *dest;          /* destination server */
+};
+
+struct ip_vs_dest_set {
+        atomic_t                size;           /* set size */
+        unsigned long           lastmod;        /* last modified time */
+        struct ip_vs_dest_list  *list;          /* destination list */
+        rwlock_t                lock;           /* lock for this list */
+};
+
+
+static struct ip_vs_dest_list *
+ip_vs_dest_set_insert(struct ip_vs_dest_set *set, struct ip_vs_dest *dest)
+{
+        struct ip_vs_dest_list *e;
+
+        for (e=set->list; e!=NULL; e=e->next) {
+                if (e->dest == dest)
+                        /* already existed */
+                        return NULL;
+        }
+
+        e = kmalloc(sizeof(struct ip_vs_dest_list), GFP_ATOMIC);
+        if (e == NULL) {
+                IP_VS_ERR("ip_vs_dest_set_insert(): no memory\n");
+                return NULL;
+        }
+
+        atomic_inc(&dest->refcnt);
+        e->dest = dest;
+
+        /* link it to the list */
+        write_lock(&set->lock);
+        e->next = set->list;
+        set->list = e;
+        atomic_inc(&set->size);
+        write_unlock(&set->lock);
+
+        set->lastmod = jiffies;
+        return e;
+}
+
+static void
+ip_vs_dest_set_erase(struct ip_vs_dest_set *set, struct ip_vs_dest *dest)
+{
+        struct ip_vs_dest_list *e, **ep;
+
+        write_lock(&set->lock);
+        for (ep=&set->list, e=*ep; e!=NULL; e=*ep) {
+                if (e->dest == dest) {
+                        /* HIT */
+                        *ep = e->next;
+                        atomic_dec(&set->size);
+                        set->lastmod = jiffies;
+                        atomic_dec(&e->dest->refcnt);
+                        kfree(e);
+                        break;
+                }
+                ep = &e->next;
+        }
+        write_unlock(&set->lock);
+}
+
+static void ip_vs_dest_set_eraseall(struct ip_vs_dest_set *set)
+{
+        struct ip_vs_dest_list *e, **ep;
+
+        write_lock(&set->lock);
+        for (ep=&set->list, e=*ep; e!=NULL; e=*ep) {
+                *ep = e->next;
+                /*
+                 * We don't kfree dest because it is refered either
+                 * by its service or by the trash dest list.
+                 */
+                atomic_dec(&e->dest->refcnt);
+                kfree(e);
+        }
+        write_unlock(&set->lock);
+}
+
+/* get weighted least-connection node in the destination set */
+static inline struct ip_vs_dest *ip_vs_dest_set_min(struct ip_vs_dest_set *set)
+{
+        register struct ip_vs_dest_list *e;
+        struct ip_vs_dest *dest, *least;
+        int loh, doh;
+
+        if (set == NULL)
+                return NULL;
+
+        read_lock(&set->lock);
+        /* select the first destination server, whose weight > 0 */
+        for (e=set->list; e!=NULL; e=e->next) {
+                least = e->dest;
+                if (least->flags & IP_VS_DEST_F_OVERLOAD)
+                        continue;
+
+                if ((atomic_read(&least->weight) > 0)
+                    && (least->flags & IP_VS_DEST_F_AVAILABLE)) {
+                        loh = atomic_read(&least->activeconns) * 50
+                                + atomic_read(&least->inactconns);
+                        goto nextstage;
+                }
+        }
+        read_unlock(&set->lock);
+        return NULL;
+
+        /* find the destination with the weighted least load */
+  nextstage:
+        for (e=e->next; e!=NULL; e=e->next) {
+                dest = e->dest;
+                if (dest->flags & IP_VS_DEST_F_OVERLOAD)
+                        continue;
+
+                doh = atomic_read(&dest->activeconns) * 50
+                        + atomic_read(&dest->inactconns);
+                if ((loh * atomic_read(&dest->weight) >
+                     doh * atomic_read(&least->weight))
+                    && (dest->flags & IP_VS_DEST_F_AVAILABLE)) {
+                        least = dest;
+                        loh = doh;
+                }
+        }
+        read_unlock(&set->lock);
+
+        IP_VS_DBG(6, "ip_vs_dest_set_min: server %d.%d.%d.%d:%d "
+                  "activeconns %d refcnt %d weight %d overhead %d\n",
+                  NIPQUAD(least->addr), ntohs(least->port),
+                  atomic_read(&least->activeconns),
+                  atomic_read(&least->refcnt),
+                  atomic_read(&least->weight), loh);
+        return least;
+}
+
+
+/* get weighted most-connection node in the destination set */
+static inline struct ip_vs_dest *ip_vs_dest_set_max(struct ip_vs_dest_set *set)
+{
+        register struct ip_vs_dest_list *e;
+        struct ip_vs_dest *dest, *most;
+        int moh, doh;
+
+        if (set == NULL)
+                return NULL;
+
+        read_lock(&set->lock);
+        /* select the first destination server, whose weight > 0 */
+        for (e=set->list; e!=NULL; e=e->next) {
+                most = e->dest;
+                if (atomic_read(&most->weight) > 0) {
+                        moh = atomic_read(&most->activeconns) * 50
+                                + atomic_read(&most->inactconns);
+                        goto nextstage;
+                }
+        }
+        read_unlock(&set->lock);
+        return NULL;
+
+        /* find the destination with the weighted most load */
+  nextstage:
+        for (e=e->next; e!=NULL; e=e->next) {
+                dest = e->dest;
+                doh = atomic_read(&dest->activeconns) * 50
+                        + atomic_read(&dest->inactconns);
+                /* moh/mw < doh/dw ==> moh*dw < doh*mw, where mw,dw>0 */
+                if ((moh * atomic_read(&dest->weight) <
+                     doh * atomic_read(&most->weight))
+                    && (atomic_read(&dest->weight) > 0)) {
+                        most = dest;
+                        moh = doh;
+                }
+        }
+        read_unlock(&set->lock);
+
+        IP_VS_DBG(6, "ip_vs_dest_set_max: server %d.%d.%d.%d:%d "
+                  "activeconns %d refcnt %d weight %d overhead %d\n",
+                  NIPQUAD(most->addr), ntohs(most->port),
+                  atomic_read(&most->activeconns),
+                  atomic_read(&most->refcnt),
+                  atomic_read(&most->weight), moh);
+        return most;
+}
+
+
+/*
+ *      IPVS lblcr entry represents an association between destination
+ *      IP address and its destination server set
+ */
+struct ip_vs_lblcr_entry {
+        struct list_head        list;
+        __u32                   addr;           /* destination IP address */
+        struct ip_vs_dest_set   set;            /* destination server set */
+        unsigned long           lastuse;        /* last used time */
+};
+
+
+/*
+ *      IPVS lblcr hash table
+ */
+struct ip_vs_lblcr_table {
+        rwlock_t                lock;           /* lock for this table */
+        struct list_head        bucket[IP_VS_LBLCR_TAB_SIZE];  /* hash bucket */
+        atomic_t                entries;        /* number of entries */
+        int                     max_size;       /* maximum size of entries */
+        struct timer_list       periodic_timer; /* collect stale entries */
+        int                     rover;          /* rover for expire check */
+        int                     counter;        /* counter for no expire */
+};
+
+
+/*
+ *      IPVS LBLCR sysctl table
+ */
+
+static ctl_table vs_vars_table[] = {
+        {
+                .ctl_name       = NET_IPV4_VS_LBLCR_EXPIRE,
+                .procname       = "lblcr_expiration",
+                .data           = &sysctl_ip_vs_lblcr_expiration,
+                .maxlen         = sizeof(int),
+                .mode           = 0644, 
+                .proc_handler   = &proc_dointvec_jiffies,
+        },
+        { .ctl_name = 0 }
+};
+
+static ctl_table vs_table[] = {
+        {
+                .ctl_name       = NET_IPV4_VS,
+                .procname       = "vs",
+                .mode           = 0555,
+                .child          = vs_vars_table
+        },
+        { .ctl_name = 0 }
+};
+
+static ctl_table ipv4_table[] = {
+        {
+                .ctl_name       = NET_IPV4,
+                .procname       = "ipv4", 
+                .mode           = 0555,
+                .child          = vs_table
+        },
+        { .ctl_name = 0 }
+};
+
+static ctl_table lblcr_root_table[] = {
+        {
+                .ctl_name       = CTL_NET,
+                .procname       = "net", 
+                .mode           = 0555, 
+                .child          = ipv4_table
+        },
+        { .ctl_name = 0 }
+};
+
+static struct ctl_table_header * sysctl_header;
+
+/*
+ *      new/free a ip_vs_lblcr_entry, which is a mapping of a destination
+ *      IP address to a server.
+ */
+static inline struct ip_vs_lblcr_entry *ip_vs_lblcr_new(__u32 daddr)
+{
+        struct ip_vs_lblcr_entry *en;
+
+        en = kmalloc(sizeof(struct ip_vs_lblcr_entry), GFP_ATOMIC);
+        if (en == NULL) {
+                IP_VS_ERR("ip_vs_lblcr_new(): no memory\n");
+                return NULL;
+        }
+
+        INIT_LIST_HEAD(&en->list);
+        en->addr = daddr;
+
+        /* initilize its dest set */
+        atomic_set(&(en->set.size), 0);
+        en->set.list = NULL;
+        rwlock_init(&en->set.lock);
+
+        return en;
+}
+
+
+static inline void ip_vs_lblcr_free(struct ip_vs_lblcr_entry *en)
+{
+        list_del(&en->list);
+        ip_vs_dest_set_eraseall(&en->set);
+        kfree(en);
+}
+
+
+/*
+ *      Returns hash value for IPVS LBLCR entry
+ */
+static inline unsigned ip_vs_lblcr_hashkey(__u32 addr)
+{
+        return (ntohl(addr)*2654435761UL) & IP_VS_LBLCR_TAB_MASK;
+}
+
+
+/*
+ *      Hash an entry in the ip_vs_lblcr_table.
+ *      returns bool success.
+ */
+static int
+ip_vs_lblcr_hash(struct ip_vs_lblcr_table *tbl, struct ip_vs_lblcr_entry *en)
+{
+        unsigned hash;
+
+        if (!list_empty(&en->list)) {
+                IP_VS_ERR("ip_vs_lblcr_hash(): request for already hashed, "
+                          "called from %p\n", __builtin_return_address(0));
+                return 0;
+        }
+
+        /*
+         *      Hash by destination IP address
+         */
+        hash = ip_vs_lblcr_hashkey(en->addr);
+
+        write_lock(&tbl->lock);
+        list_add(&en->list, &tbl->bucket[hash]);
+        atomic_inc(&tbl->entries);
+        write_unlock(&tbl->lock);
+
+        return 1;
+}
+
+
+#if 0000
+/*
+ *      Unhash ip_vs_lblcr_entry from ip_vs_lblcr_table.
+ *      returns bool success.
+ */
+static int ip_vs_lblcr_unhash(struct ip_vs_lblcr_table *tbl,
+                             struct ip_vs_lblcr_entry *en)
+{
+        if (list_empty(&en->list)) {
+                IP_VS_ERR("ip_vs_lblcr_unhash(): request for not hashed entry, "
+                          "called from %p\n", __builtin_return_address(0));
+                return 0;
+        }
+
+        /*
+         * Remove it from the table
+         */
+        write_lock(&tbl->lock);
+        list_del(&en->list);
+        INIT_LIST_HEAD(&en->list);
+        write_unlock(&tbl->lock);
+
+        return 1;
+}
+#endif
+
+
+/*
+ *  Get ip_vs_lblcr_entry associated with supplied parameters.
+ */
+static inline struct ip_vs_lblcr_entry *
+ip_vs_lblcr_get(struct ip_vs_lblcr_table *tbl, __u32 addr)
+{
+        unsigned hash;
+        struct ip_vs_lblcr_entry *en;
+
+        hash = ip_vs_lblcr_hashkey(addr);
+
+        read_lock(&tbl->lock);
+
+        list_for_each_entry(en, &tbl->bucket[hash], list) {
+                if (en->addr == addr) {
+                        /* HIT */
+                        read_unlock(&tbl->lock);
+                        return en;
+                }
+        }
+
+        read_unlock(&tbl->lock);
+
+        return NULL;
+}
+
+
+/*
+ *      Flush all the entries of the specified table.
+ */
+static void ip_vs_lblcr_flush(struct ip_vs_lblcr_table *tbl)
+{
+        int i;
+        struct ip_vs_lblcr_entry *en, *nxt;
+
+        for (i=0; i<IP_VS_LBLCR_TAB_SIZE; i++) {
+                write_lock(&tbl->lock);
+                list_for_each_entry_safe(en, nxt, &tbl->bucket[i], list) {
+                        ip_vs_lblcr_free(en);
+                        atomic_dec(&tbl->entries);
+                }
+                write_unlock(&tbl->lock);
+        }
+}
+
+
+static inline void ip_vs_lblcr_full_check(struct ip_vs_lblcr_table *tbl)
+{
+        unsigned long now = jiffies;
+        int i, j;
+        struct ip_vs_lblcr_entry *en, *nxt;
+
+        for (i=0, j=tbl->rover; i<IP_VS_LBLCR_TAB_SIZE; i++) {
+                j = (j + 1) & IP_VS_LBLCR_TAB_MASK;
+
+                write_lock(&tbl->lock);
+                list_for_each_entry_safe(en, nxt, &tbl->bucket[j], list) {
+                        if (time_after(en->lastuse+sysctl_ip_vs_lblcr_expiration,
+                                       now))
+                                continue;
+
+                        ip_vs_lblcr_free(en);
+                        atomic_dec(&tbl->entries);
+                }
+                write_unlock(&tbl->lock);
+        }
+        tbl->rover = j;
+}
+
+
+/*
+ *      Periodical timer handler for IPVS lblcr table
+ *      It is used to collect stale entries when the number of entries
+ *      exceeds the maximum size of the table.
+ *
+ *      Fixme: we probably need more complicated algorithm to collect
+ *             entries that have not been used for a long time even
+ *             if the number of entries doesn't exceed the maximum size
+ *             of the table.
+ *      The full expiration check is for this purpose now.
+ */
+static void ip_vs_lblcr_check_expire(unsigned long data)
+{
+        struct ip_vs_lblcr_table *tbl;
+        unsigned long now = jiffies;
+        int goal;
+        int i, j;
+        struct ip_vs_lblcr_entry *en, *nxt;
+
+        tbl = (struct ip_vs_lblcr_table *)data;
+
+        if ((tbl->counter % COUNT_FOR_FULL_EXPIRATION) == 0) {
+                /* do full expiration check */
+                ip_vs_lblcr_full_check(tbl);
+                tbl->counter = 1;
+                goto out;
+        }
+
+        if (atomic_read(&tbl->entries) <= tbl->max_size) {
+                tbl->counter++;
+                goto out;
+        }
+
+        goal = (atomic_read(&tbl->entries) - tbl->max_size)*4/3;
+        if (goal > tbl->max_size/2)
+                goal = tbl->max_size/2;
+
+        for (i=0, j=tbl->rover; i<IP_VS_LBLCR_TAB_SIZE; i++) {
+                j = (j + 1) & IP_VS_LBLCR_TAB_MASK;
+
+                write_lock(&tbl->lock);
+                list_for_each_entry_safe(en, nxt, &tbl->bucket[j], list) {
+                        if (time_before(now, en->lastuse+ENTRY_TIMEOUT))
+                                continue;
+
+                        ip_vs_lblcr_free(en);
+                        atomic_dec(&tbl->entries);
+                        goal--;
+                }
+                write_unlock(&tbl->lock);
+                if (goal <= 0)
+                        break;
+        }
+        tbl->rover = j;
+
+  out:
+        mod_timer(&tbl->periodic_timer, jiffies+CHECK_EXPIRE_INTERVAL);
+}
+
+
+#ifdef CONFIG_IP_VS_LBLCR_DEBUG
+static struct ip_vs_lblcr_table *lblcr_table_list;
+
+/*
+ *      /proc/net/ip_vs_lblcr to display the mappings of
+ *                  destination IP address <==> its serverSet
+ */
+static int
+ip_vs_lblcr_getinfo(char *buffer, char **start, off_t offset, int length)
+{
+        off_t pos=0, begin;
+        int len=0, size;
+        struct ip_vs_lblcr_table *tbl;
+        unsigned long now = jiffies;
+        int i;
+        struct ip_vs_lblcr_entry *en;
+
+        tbl = lblcr_table_list;
+
+        size = sprintf(buffer, "LastTime Dest IP address  Server set\n");
+        pos += size;
+        len += size;
+
+        for (i=0; i<IP_VS_LBLCR_TAB_SIZE; i++) {
+                read_lock_bh(&tbl->lock);
+                list_for_each_entry(en, &tbl->bucket[i], list) {
+                        char tbuf[16];
+                        struct ip_vs_dest_list *d;
+
+                        sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(en->addr));
+                        size = sprintf(buffer+len, "%8lu %-16s ",
+                                       now-en->lastuse, tbuf);
+
+                        read_lock(&en->set.lock);
+                        for (d=en->set.list; d!=NULL; d=d->next) {
+                                size += sprintf(buffer+len+size,
+                                                "%u.%u.%u.%u ",
+                                                NIPQUAD(d->dest->addr));
+                        }
+                        read_unlock(&en->set.lock);
+                        size += sprintf(buffer+len+size, "\n");
+                        len += size;
+                        pos += size;
+                        if (pos <= offset)
+                                len=0;
+                        if (pos >= offset+length) {
+                                read_unlock_bh(&tbl->lock);
+                                goto done;
+                        }
+                }
+                read_unlock_bh(&tbl->lock);
+        }
+
+  done:
+        begin = len - (pos - offset);
+        *start = buffer + begin;
+        len -= begin;
+        if(len>length)
+                len = length;
+        return len;
+}
+#endif
+
+
+static int ip_vs_lblcr_init_svc(struct ip_vs_service *svc)
+{
+        int i;
+        struct ip_vs_lblcr_table *tbl;
+
+        /*
+         *    Allocate the ip_vs_lblcr_table for this service
+         */
+        tbl = kmalloc(sizeof(struct ip_vs_lblcr_table), GFP_ATOMIC);
+        if (tbl == NULL) {
+                IP_VS_ERR("ip_vs_lblcr_init_svc(): no memory\n");
+                return -ENOMEM;
+        }
+        svc->sched_data = tbl;
+        IP_VS_DBG(6, "LBLCR hash table (memory=%Zdbytes) allocated for "
+                  "current service\n",
+                  sizeof(struct ip_vs_lblcr_table));
+
+        /*
+         *    Initialize the hash buckets
+         */
+        for (i=0; i<IP_VS_LBLCR_TAB_SIZE; i++) {
+                INIT_LIST_HEAD(&tbl->bucket[i]);
+        }
+        rwlock_init(&tbl->lock);
+        tbl->max_size = IP_VS_LBLCR_TAB_SIZE*16;
+        tbl->rover = 0;
+        tbl->counter = 1;
+
+        /*
+         *    Hook periodic timer for garbage collection
+         */
+        init_timer(&tbl->periodic_timer);
+        tbl->periodic_timer.data = (unsigned long)tbl;
+        tbl->periodic_timer.function = ip_vs_lblcr_check_expire;
+        tbl->periodic_timer.expires = jiffies+CHECK_EXPIRE_INTERVAL;
+        add_timer(&tbl->periodic_timer);
+
+#ifdef CONFIG_IP_VS_LBLCR_DEBUG
+        lblcr_table_list = tbl;
+#endif
+        return 0;
+}
+
+
+static int ip_vs_lblcr_done_svc(struct ip_vs_service *svc)
+{
+        struct ip_vs_lblcr_table *tbl = svc->sched_data;
+
+        /* remove periodic timer */
+        del_timer_sync(&tbl->periodic_timer);
+
+        /* got to clean up table entries here */
+        ip_vs_lblcr_flush(tbl);
+
+        /* release the table itself */
+        kfree(svc->sched_data);
+        IP_VS_DBG(6, "LBLCR hash table (memory=%Zdbytes) released\n",
+                  sizeof(struct ip_vs_lblcr_table));
+
+        return 0;
+}
+
+
+static int ip_vs_lblcr_update_svc(struct ip_vs_service *svc)
+{
+        return 0;
+}
+
+
+static inline struct ip_vs_dest *
+__ip_vs_wlc_schedule(struct ip_vs_service *svc, struct iphdr *iph)
+{
+        struct ip_vs_dest *dest, *least;
+        int loh, doh;
+
+        /*
+         * We think the overhead of processing active connections is fifty
+         * times higher than that of inactive connections in average. (This
+         * fifty times might not be accurate, we will change it later.) We
+         * use the following formula to estimate the overhead:
+         *                dest->activeconns*50 + dest->inactconns
+         * and the load:
+         *                (dest overhead) / dest->weight
+         *
+         * Remember -- no floats in kernel mode!!!
+         * The comparison of h1*w2 > h2*w1 is equivalent to that of
+         *                h1/w1 > h2/w2
+         * if every weight is larger than zero.
+         *
+         * The server with weight=0 is quiesced and will not receive any
+         * new connection.
+         */
+        list_for_each_entry(dest, &svc->destinations, n_list) {
+                if (dest->flags & IP_VS_DEST_F_OVERLOAD)
+                        continue;
+
+                if (atomic_read(&dest->weight) > 0) {
+                        least = dest;
+                        loh = atomic_read(&least->activeconns) * 50
+                                + atomic_read(&least->inactconns);
+                        goto nextstage;
+                }
+        }
+        return NULL;
+
+        /*
+         *    Find the destination with the least load.
+         */
+  nextstage:
+        list_for_each_entry_continue(dest, &svc->destinations, n_list) {
+                if (dest->flags & IP_VS_DEST_F_OVERLOAD)
+                        continue;
+
+                doh = atomic_read(&dest->activeconns) * 50
+                        + atomic_read(&dest->inactconns);
+                if (loh * atomic_read(&dest->weight) >
+                    doh * atomic_read(&least->weight)) {
+                        least = dest;
+                        loh = doh;
+                }
+        }
+
+        IP_VS_DBG(6, "LBLCR: server %d.%d.%d.%d:%d "
+                  "activeconns %d refcnt %d weight %d overhead %d\n",
+                  NIPQUAD(least->addr), ntohs(least->port),
+                  atomic_read(&least->activeconns),
+                  atomic_read(&least->refcnt),
+                  atomic_read(&least->weight), loh);
+
+        return least;
+}
+
+
+/*
+ *   If this destination server is overloaded and there is a less loaded
+ *   server, then return true.
+ */
+static inline int
+is_overloaded(struct ip_vs_dest *dest, struct ip_vs_service *svc)
+{
+        if (atomic_read(&dest->activeconns) > atomic_read(&dest->weight)) {
+                struct ip_vs_dest *d;
+
+                list_for_each_entry(d, &svc->destinations, n_list) {
+                        if (atomic_read(&d->activeconns)*2
+                            < atomic_read(&d->weight)) {
+                                return 1;
+                        }
+                }
+        }
+        return 0;
+}
+
+
+/*
+ *    Locality-Based (weighted) Least-Connection scheduling
+ */
+static struct ip_vs_dest *
+ip_vs_lblcr_schedule(struct ip_vs_service *svc, const struct sk_buff *skb)
+{
+        struct ip_vs_dest *dest;
+        struct ip_vs_lblcr_table *tbl;
+        struct ip_vs_lblcr_entry *en;
+        struct iphdr *iph = skb->nh.iph;
+
+        IP_VS_DBG(6, "ip_vs_lblcr_schedule(): Scheduling...\n");
+
+        tbl = (struct ip_vs_lblcr_table *)svc->sched_data;
+        en = ip_vs_lblcr_get(tbl, iph->daddr);
+        if (en == NULL) {
+                dest = __ip_vs_wlc_schedule(svc, iph);
+                if (dest == NULL) {
+                        IP_VS_DBG(1, "no destination available\n");
+                        return NULL;
+                }
+                en = ip_vs_lblcr_new(iph->daddr);
+                if (en == NULL) {
+                        return NULL;
+                }
+                ip_vs_dest_set_insert(&en->set, dest);
+                ip_vs_lblcr_hash(tbl, en);
+        } else {
+                dest = ip_vs_dest_set_min(&en->set);
+                if (!dest || is_overloaded(dest, svc)) {
+                        dest = __ip_vs_wlc_schedule(svc, iph);
+                        if (dest == NULL) {
+                                IP_VS_DBG(1, "no destination available\n");
+                                return NULL;
+                        }
+                        ip_vs_dest_set_insert(&en->set, dest);
+                }
+                if (atomic_read(&en->set.size) > 1 &&
+                    jiffies-en->set.lastmod > sysctl_ip_vs_lblcr_expiration) {
+                        struct ip_vs_dest *m;
+                        m = ip_vs_dest_set_max(&en->set);
+                        if (m)
+                                ip_vs_dest_set_erase(&en->set, m);
+                }
+        }
+        en->lastuse = jiffies;
+
+        IP_VS_DBG(6, "LBLCR: destination IP address %u.%u.%u.%u "
+                  "--> server %u.%u.%u.%u:%d\n",
+                  NIPQUAD(en->addr),
+                  NIPQUAD(dest->addr),
+                  ntohs(dest->port));
+
+        return dest;
+}
+
+
+/*
+ *      IPVS LBLCR Scheduler structure
+ */
+static struct ip_vs_scheduler ip_vs_lblcr_scheduler =
+{
+        .name =                 "lblcr",
+        .refcnt =               ATOMIC_INIT(0),
+        .module =               THIS_MODULE,
+        .init_service =         ip_vs_lblcr_init_svc,
+        .done_service =         ip_vs_lblcr_done_svc,
+        .update_service =       ip_vs_lblcr_update_svc,
+        .schedule =             ip_vs_lblcr_schedule,
+};
+
+
+static int __init ip_vs_lblcr_init(void)
+{
+        INIT_LIST_HEAD(&ip_vs_lblcr_scheduler.n_list);
+        sysctl_header = register_sysctl_table(lblcr_root_table, 0);
+#ifdef CONFIG_IP_VS_LBLCR_DEBUG
+        proc_net_create("ip_vs_lblcr", 0, ip_vs_lblcr_getinfo);
+#endif
+        return register_ip_vs_scheduler(&ip_vs_lblcr_scheduler);
+}
+
+
+static void __exit ip_vs_lblcr_cleanup(void)
+{
+#ifdef CONFIG_IP_VS_LBLCR_DEBUG
+        proc_net_remove("ip_vs_lblcr");
+#endif
+        unregister_sysctl_table(sysctl_header);
+        unregister_ip_vs_scheduler(&ip_vs_lblcr_scheduler);
+}
+
+
+module_init(ip_vs_lblcr_init);
+module_exit(ip_vs_lblcr_cleanup);
+MODULE_LICENSE("GPL");