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[/] [or1k_soc_on_altera_embedded_dev_kit/] [trunk/] [linux-2.6/] [linux-2.6.24/] [fs/] [afs/] [vlocation.c] - Blame information for rev 17

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/* AFS volume location management
 *
 * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * 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 <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include "internal.h"
 
static unsigned afs_vlocation_timeout = 10;     /* volume location timeout in seconds */
static unsigned afs_vlocation_update_timeout = 10 * 60;
 
static void afs_vlocation_reaper(struct work_struct *);
static void afs_vlocation_updater(struct work_struct *);
 
static LIST_HEAD(afs_vlocation_updates);
static LIST_HEAD(afs_vlocation_graveyard);
static DEFINE_SPINLOCK(afs_vlocation_updates_lock);
static DEFINE_SPINLOCK(afs_vlocation_graveyard_lock);
static DECLARE_DELAYED_WORK(afs_vlocation_reap, afs_vlocation_reaper);
static DECLARE_DELAYED_WORK(afs_vlocation_update, afs_vlocation_updater);
static struct workqueue_struct *afs_vlocation_update_worker;
 
/*
 * iterate through the VL servers in a cell until one of them admits knowing
 * about the volume in question
 */
static int afs_vlocation_access_vl_by_name(struct afs_vlocation *vl,
                                           struct key *key,
                                           struct afs_cache_vlocation *vldb)
{
        struct afs_cell *cell = vl->cell;
        struct in_addr addr;
        int count, ret;
 
        _enter("%s,%s", cell->name, vl->vldb.name);
 
        down_write(&vl->cell->vl_sem);
        ret = -ENOMEDIUM;
        for (count = cell->vl_naddrs; count > 0; count--) {
                addr = cell->vl_addrs[cell->vl_curr_svix];
 
                _debug("CellServ[%hu]: %08x", cell->vl_curr_svix, addr.s_addr);
 
                /* attempt to access the VL server */
                ret = afs_vl_get_entry_by_name(&addr, key, vl->vldb.name, vldb,
                                               &afs_sync_call);
                switch (ret) {
                case 0:
                        goto out;
                case -ENOMEM:
                case -ENONET:
                case -ENETUNREACH:
                case -EHOSTUNREACH:
                case -ECONNREFUSED:
                        if (ret == -ENOMEM || ret == -ENONET)
                                goto out;
                        goto rotate;
                case -ENOMEDIUM:
                        goto out;
                default:
                        ret = -EIO;
                        goto rotate;
                }
 
                /* rotate the server records upon lookup failure */
        rotate:
                cell->vl_curr_svix++;
                cell->vl_curr_svix %= cell->vl_naddrs;
        }
 
out:
        up_write(&vl->cell->vl_sem);
        _leave(" = %d", ret);
        return ret;
}
 
/*
 * iterate through the VL servers in a cell until one of them admits knowing
 * about the volume in question
 */
static int afs_vlocation_access_vl_by_id(struct afs_vlocation *vl,
                                         struct key *key,
                                         afs_volid_t volid,
                                         afs_voltype_t voltype,
                                         struct afs_cache_vlocation *vldb)
{
        struct afs_cell *cell = vl->cell;
        struct in_addr addr;
        int count, ret;
 
        _enter("%s,%x,%d,", cell->name, volid, voltype);
 
        down_write(&vl->cell->vl_sem);
        ret = -ENOMEDIUM;
        for (count = cell->vl_naddrs; count > 0; count--) {
                addr = cell->vl_addrs[cell->vl_curr_svix];
 
                _debug("CellServ[%hu]: %08x", cell->vl_curr_svix, addr.s_addr);
 
                /* attempt to access the VL server */
                ret = afs_vl_get_entry_by_id(&addr, key, volid, voltype, vldb,
                                             &afs_sync_call);
                switch (ret) {
                case 0:
                        goto out;
                case -ENOMEM:
                case -ENONET:
                case -ENETUNREACH:
                case -EHOSTUNREACH:
                case -ECONNREFUSED:
                        if (ret == -ENOMEM || ret == -ENONET)
                                goto out;
                        goto rotate;
                case -EBUSY:
                        vl->upd_busy_cnt++;
                        if (vl->upd_busy_cnt <= 3) {
                                if (vl->upd_busy_cnt > 1) {
                                        /* second+ BUSY - sleep a little bit */
                                        set_current_state(TASK_UNINTERRUPTIBLE);
                                        schedule_timeout(1);
                                        __set_current_state(TASK_RUNNING);
                                }
                                continue;
                        }
                        break;
                case -ENOMEDIUM:
                        vl->upd_rej_cnt++;
                        goto rotate;
                default:
                        ret = -EIO;
                        goto rotate;
                }
 
                /* rotate the server records upon lookup failure */
        rotate:
                cell->vl_curr_svix++;
                cell->vl_curr_svix %= cell->vl_naddrs;
                vl->upd_busy_cnt = 0;
        }
 
out:
        if (ret < 0 && vl->upd_rej_cnt > 0) {
                printk(KERN_NOTICE "kAFS:"
                       " Active volume no longer valid '%s'\n",
                       vl->vldb.name);
                vl->valid = 0;
                ret = -ENOMEDIUM;
        }
 
        up_write(&vl->cell->vl_sem);
        _leave(" = %d", ret);
        return ret;
}
 
/*
 * allocate a volume location record
 */
static struct afs_vlocation *afs_vlocation_alloc(struct afs_cell *cell,
                                                 const char *name,
                                                 size_t namesz)
{
        struct afs_vlocation *vl;
 
        vl = kzalloc(sizeof(struct afs_vlocation), GFP_KERNEL);
        if (vl) {
                vl->cell = cell;
                vl->state = AFS_VL_NEW;
                atomic_set(&vl->usage, 1);
                INIT_LIST_HEAD(&vl->link);
                INIT_LIST_HEAD(&vl->grave);
                INIT_LIST_HEAD(&vl->update);
                init_waitqueue_head(&vl->waitq);
                spin_lock_init(&vl->lock);
                memcpy(vl->vldb.name, name, namesz);
        }
 
        _leave(" = %p", vl);
        return vl;
}
 
/*
 * update record if we found it in the cache
 */
static int afs_vlocation_update_record(struct afs_vlocation *vl,
                                       struct key *key,
                                       struct afs_cache_vlocation *vldb)
{
        afs_voltype_t voltype;
        afs_volid_t vid;
        int ret;
 
        /* try to look up a cached volume in the cell VL databases by ID */
        _debug("Locally Cached: %s %02x { %08x(%x) %08x(%x) %08x(%x) }",
               vl->vldb.name,
               vl->vldb.vidmask,
               ntohl(vl->vldb.servers[0].s_addr),
               vl->vldb.srvtmask[0],
               ntohl(vl->vldb.servers[1].s_addr),
               vl->vldb.srvtmask[1],
               ntohl(vl->vldb.servers[2].s_addr),
               vl->vldb.srvtmask[2]);
 
        _debug("Vids: %08x %08x %08x",
               vl->vldb.vid[0],
               vl->vldb.vid[1],
               vl->vldb.vid[2]);
 
        if (vl->vldb.vidmask & AFS_VOL_VTM_RW) {
                vid = vl->vldb.vid[0];
                voltype = AFSVL_RWVOL;
        } else if (vl->vldb.vidmask & AFS_VOL_VTM_RO) {
                vid = vl->vldb.vid[1];
                voltype = AFSVL_ROVOL;
        } else if (vl->vldb.vidmask & AFS_VOL_VTM_BAK) {
                vid = vl->vldb.vid[2];
                voltype = AFSVL_BACKVOL;
        } else {
                BUG();
                vid = 0;
                voltype = 0;
        }
 
        /* contact the server to make sure the volume is still available
         * - TODO: need to handle disconnected operation here
         */
        ret = afs_vlocation_access_vl_by_id(vl, key, vid, voltype, vldb);
        switch (ret) {
                /* net error */
        default:
                printk(KERN_WARNING "kAFS:"
                       " failed to update volume '%s' (%x) up in '%s': %d\n",
                       vl->vldb.name, vid, vl->cell->name, ret);
                _leave(" = %d", ret);
                return ret;
 
                /* pulled from local cache into memory */
        case 0:
                _leave(" = 0");
                return 0;
 
                /* uh oh... looks like the volume got deleted */
        case -ENOMEDIUM:
                printk(KERN_ERR "kAFS:"
                       " volume '%s' (%x) does not exist '%s'\n",
                       vl->vldb.name, vid, vl->cell->name);
 
                /* TODO: make existing record unavailable */
                _leave(" = %d", ret);
                return ret;
        }
}
 
/*
 * apply the update to a VL record
 */
static void afs_vlocation_apply_update(struct afs_vlocation *vl,
                                       struct afs_cache_vlocation *vldb)
{
        _debug("Done VL Lookup: %s %02x { %08x(%x) %08x(%x) %08x(%x) }",
               vldb->name, vldb->vidmask,
               ntohl(vldb->servers[0].s_addr), vldb->srvtmask[0],
               ntohl(vldb->servers[1].s_addr), vldb->srvtmask[1],
               ntohl(vldb->servers[2].s_addr), vldb->srvtmask[2]);
 
        _debug("Vids: %08x %08x %08x",
               vldb->vid[0], vldb->vid[1], vldb->vid[2]);
 
        if (strcmp(vldb->name, vl->vldb.name) != 0)
                printk(KERN_NOTICE "kAFS:"
                       " name of volume '%s' changed to '%s' on server\n",
                       vl->vldb.name, vldb->name);
 
        vl->vldb = *vldb;
 
#ifdef AFS_CACHING_SUPPORT
        /* update volume entry in local cache */
        cachefs_update_cookie(vl->cache);
#endif
}
 
/*
 * fill in a volume location record, consulting the cache and the VL server
 * both
 */
static int afs_vlocation_fill_in_record(struct afs_vlocation *vl,
                                        struct key *key)
{
        struct afs_cache_vlocation vldb;
        int ret;
 
        _enter("");
 
        ASSERTCMP(vl->valid, ==, 0);
 
        memset(&vldb, 0, sizeof(vldb));
 
        /* see if we have an in-cache copy (will set vl->valid if there is) */
#ifdef AFS_CACHING_SUPPORT
        cachefs_acquire_cookie(cell->cache,
                               &afs_volume_cache_index_def,
                               vlocation,
                               &vl->cache);
#endif
 
        if (vl->valid) {
                /* try to update a known volume in the cell VL databases by
                 * ID as the name may have changed */
                _debug("found in cache");
                ret = afs_vlocation_update_record(vl, key, &vldb);
        } else {
                /* try to look up an unknown volume in the cell VL databases by
                 * name */
                ret = afs_vlocation_access_vl_by_name(vl, key, &vldb);
                if (ret < 0) {
                        printk("kAFS: failed to locate '%s' in cell '%s'\n",
                               vl->vldb.name, vl->cell->name);
                        return ret;
                }
        }
 
        afs_vlocation_apply_update(vl, &vldb);
        _leave(" = 0");
        return 0;
}
 
/*
 * queue a vlocation record for updates
 */
static void afs_vlocation_queue_for_updates(struct afs_vlocation *vl)
{
        struct afs_vlocation *xvl;
 
        /* wait at least 10 minutes before updating... */
        vl->update_at = get_seconds() + afs_vlocation_update_timeout;
 
        spin_lock(&afs_vlocation_updates_lock);
 
        if (!list_empty(&afs_vlocation_updates)) {
                /* ... but wait at least 1 second more than the newest record
                 * already queued so that we don't spam the VL server suddenly
                 * with lots of requests
                 */
                xvl = list_entry(afs_vlocation_updates.prev,
                                 struct afs_vlocation, update);
                if (vl->update_at <= xvl->update_at)
                        vl->update_at = xvl->update_at + 1;
        } else {
                queue_delayed_work(afs_vlocation_update_worker,
                                   &afs_vlocation_update,
                                   afs_vlocation_update_timeout * HZ);
        }
 
        list_add_tail(&vl->update, &afs_vlocation_updates);
        spin_unlock(&afs_vlocation_updates_lock);
}
 
/*
 * lookup volume location
 * - iterate through the VL servers in a cell until one of them admits knowing
 *   about the volume in question
 * - lookup in the local cache if not able to find on the VL server
 * - insert/update in the local cache if did get a VL response
 */
struct afs_vlocation *afs_vlocation_lookup(struct afs_cell *cell,
                                           struct key *key,
                                           const char *name,
                                           size_t namesz)
{
        struct afs_vlocation *vl;
        int ret;
 
        _enter("{%s},{%x},%*.*s,%zu",
               cell->name, key_serial(key),
               (int) namesz, (int) namesz, name, namesz);
 
        if (namesz >= sizeof(vl->vldb.name)) {
                _leave(" = -ENAMETOOLONG");
                return ERR_PTR(-ENAMETOOLONG);
        }
 
        /* see if we have an in-memory copy first */
        down_write(&cell->vl_sem);
        spin_lock(&cell->vl_lock);
        list_for_each_entry(vl, &cell->vl_list, link) {
                if (vl->vldb.name[namesz] != '\0')
                        continue;
                if (memcmp(vl->vldb.name, name, namesz) == 0)
                        goto found_in_memory;
        }
        spin_unlock(&cell->vl_lock);
 
        /* not in the cell's in-memory lists - create a new record */
        vl = afs_vlocation_alloc(cell, name, namesz);
        if (!vl) {
                up_write(&cell->vl_sem);
                return ERR_PTR(-ENOMEM);
        }
 
        afs_get_cell(cell);
 
        list_add_tail(&vl->link, &cell->vl_list);
        vl->state = AFS_VL_CREATING;
        up_write(&cell->vl_sem);
 
fill_in_record:
        ret = afs_vlocation_fill_in_record(vl, key);
        if (ret < 0)
                goto error_abandon;
        spin_lock(&vl->lock);
        vl->state = AFS_VL_VALID;
        spin_unlock(&vl->lock);
        wake_up(&vl->waitq);
 
        /* schedule for regular updates */
        afs_vlocation_queue_for_updates(vl);
        goto success;
 
found_in_memory:
        /* found in memory */
        _debug("found in memory");
        atomic_inc(&vl->usage);
        spin_unlock(&cell->vl_lock);
        if (!list_empty(&vl->grave)) {
                spin_lock(&afs_vlocation_graveyard_lock);
                list_del_init(&vl->grave);
                spin_unlock(&afs_vlocation_graveyard_lock);
        }
        up_write(&cell->vl_sem);
 
        /* see if it was an abandoned record that we might try filling in */
        spin_lock(&vl->lock);
        while (vl->state != AFS_VL_VALID) {
                afs_vlocation_state_t state = vl->state;
 
                _debug("invalid [state %d]", state);
 
                if (state == AFS_VL_NEW || state == AFS_VL_NO_VOLUME) {
                        vl->state = AFS_VL_CREATING;
                        spin_unlock(&vl->lock);
                        goto fill_in_record;
                }
 
                /* must now wait for creation or update by someone else to
                 * complete */
                _debug("wait");
 
                spin_unlock(&vl->lock);
                ret = wait_event_interruptible(vl->waitq,
                                               vl->state == AFS_VL_NEW ||
                                               vl->state == AFS_VL_VALID ||
                                               vl->state == AFS_VL_NO_VOLUME);
                if (ret < 0)
                        goto error;
                spin_lock(&vl->lock);
        }
        spin_unlock(&vl->lock);
 
success:
        _leave(" = %p",vl);
        return vl;
 
error_abandon:
        spin_lock(&vl->lock);
        vl->state = AFS_VL_NEW;
        spin_unlock(&vl->lock);
        wake_up(&vl->waitq);
error:
        ASSERT(vl != NULL);
        afs_put_vlocation(vl);
        _leave(" = %d", ret);
        return ERR_PTR(ret);
}
 
/*
 * finish using a volume location record
 */
void afs_put_vlocation(struct afs_vlocation *vl)
{
        if (!vl)
                return;
 
        _enter("%s", vl->vldb.name);
 
        ASSERTCMP(atomic_read(&vl->usage), >, 0);
 
        if (likely(!atomic_dec_and_test(&vl->usage))) {
                _leave("");
                return;
        }
 
        spin_lock(&afs_vlocation_graveyard_lock);
        if (atomic_read(&vl->usage) == 0) {
                _debug("buried");
                list_move_tail(&vl->grave, &afs_vlocation_graveyard);
                vl->time_of_death = get_seconds();
                schedule_delayed_work(&afs_vlocation_reap,
                                      afs_vlocation_timeout * HZ);
 
                /* suspend updates on this record */
                if (!list_empty(&vl->update)) {
                        spin_lock(&afs_vlocation_updates_lock);
                        list_del_init(&vl->update);
                        spin_unlock(&afs_vlocation_updates_lock);
                }
        }
        spin_unlock(&afs_vlocation_graveyard_lock);
        _leave(" [killed?]");
}
 
/*
 * destroy a dead volume location record
 */
static void afs_vlocation_destroy(struct afs_vlocation *vl)
{
        _enter("%p", vl);
 
#ifdef AFS_CACHING_SUPPORT
        cachefs_relinquish_cookie(vl->cache, 0);
#endif
 
        afs_put_cell(vl->cell);
        kfree(vl);
}
 
/*
 * reap dead volume location records
 */
static void afs_vlocation_reaper(struct work_struct *work)
{
        LIST_HEAD(corpses);
        struct afs_vlocation *vl;
        unsigned long delay, expiry;
        time_t now;
 
        _enter("");
 
        now = get_seconds();
        spin_lock(&afs_vlocation_graveyard_lock);
 
        while (!list_empty(&afs_vlocation_graveyard)) {
                vl = list_entry(afs_vlocation_graveyard.next,
                                struct afs_vlocation, grave);
 
                _debug("check %p", vl);
 
                /* the queue is ordered most dead first */
                expiry = vl->time_of_death + afs_vlocation_timeout;
                if (expiry > now) {
                        delay = (expiry - now) * HZ;
                        _debug("delay %lu", delay);
                        if (!schedule_delayed_work(&afs_vlocation_reap,
                                                   delay)) {
                                cancel_delayed_work(&afs_vlocation_reap);
                                schedule_delayed_work(&afs_vlocation_reap,
                                                      delay);
                        }
                        break;
                }
 
                spin_lock(&vl->cell->vl_lock);
                if (atomic_read(&vl->usage) > 0) {
                        _debug("no reap");
                        list_del_init(&vl->grave);
                } else {
                        _debug("reap");
                        list_move_tail(&vl->grave, &corpses);
                        list_del_init(&vl->link);
                }
                spin_unlock(&vl->cell->vl_lock);
        }
 
        spin_unlock(&afs_vlocation_graveyard_lock);
 
        /* now reap the corpses we've extracted */
        while (!list_empty(&corpses)) {
                vl = list_entry(corpses.next, struct afs_vlocation, grave);
                list_del(&vl->grave);
                afs_vlocation_destroy(vl);
        }
 
        _leave("");
}
 
/*
 * initialise the VL update process
 */
int __init afs_vlocation_update_init(void)
{
        afs_vlocation_update_worker =
                create_singlethread_workqueue("kafs_vlupdated");
        return afs_vlocation_update_worker ? 0 : -ENOMEM;
}
 
/*
 * discard all the volume location records for rmmod
 */
void afs_vlocation_purge(void)
{
        afs_vlocation_timeout = 0;
 
        spin_lock(&afs_vlocation_updates_lock);
        list_del_init(&afs_vlocation_updates);
        spin_unlock(&afs_vlocation_updates_lock);
        cancel_delayed_work(&afs_vlocation_update);
        queue_delayed_work(afs_vlocation_update_worker,
                           &afs_vlocation_update, 0);
        destroy_workqueue(afs_vlocation_update_worker);
 
        cancel_delayed_work(&afs_vlocation_reap);
        schedule_delayed_work(&afs_vlocation_reap, 0);
}
 
/*
 * update a volume location
 */
static void afs_vlocation_updater(struct work_struct *work)
{
        struct afs_cache_vlocation vldb;
        struct afs_vlocation *vl, *xvl;
        time_t now;
        long timeout;
        int ret;
 
        _enter("");
 
        now = get_seconds();
 
        /* find a record to update */
        spin_lock(&afs_vlocation_updates_lock);
        for (;;) {
                if (list_empty(&afs_vlocation_updates)) {
                        spin_unlock(&afs_vlocation_updates_lock);
                        _leave(" [nothing]");
                        return;
                }
 
                vl = list_entry(afs_vlocation_updates.next,
                                struct afs_vlocation, update);
                if (atomic_read(&vl->usage) > 0)
                        break;
                list_del_init(&vl->update);
        }
 
        timeout = vl->update_at - now;
        if (timeout > 0) {
                queue_delayed_work(afs_vlocation_update_worker,
                                   &afs_vlocation_update, timeout * HZ);
                spin_unlock(&afs_vlocation_updates_lock);
                _leave(" [nothing]");
                return;
        }
 
        list_del_init(&vl->update);
        atomic_inc(&vl->usage);
        spin_unlock(&afs_vlocation_updates_lock);
 
        /* we can now perform the update */
        _debug("update %s", vl->vldb.name);
        vl->state = AFS_VL_UPDATING;
        vl->upd_rej_cnt = 0;
        vl->upd_busy_cnt = 0;
 
        ret = afs_vlocation_update_record(vl, NULL, &vldb);
        spin_lock(&vl->lock);
        switch (ret) {
        case 0:
                afs_vlocation_apply_update(vl, &vldb);
                vl->state = AFS_VL_VALID;
                break;
        case -ENOMEDIUM:
                vl->state = AFS_VL_VOLUME_DELETED;
                break;
        default:
                vl->state = AFS_VL_UNCERTAIN;
                break;
        }
        spin_unlock(&vl->lock);
        wake_up(&vl->waitq);
 
        /* and then reschedule */
        _debug("reschedule");
        vl->update_at = get_seconds() + afs_vlocation_update_timeout;
 
        spin_lock(&afs_vlocation_updates_lock);
 
        if (!list_empty(&afs_vlocation_updates)) {
                /* next update in 10 minutes, but wait at least 1 second more
                 * than the newest record already queued so that we don't spam
                 * the VL server suddenly with lots of requests
                 */
                xvl = list_entry(afs_vlocation_updates.prev,
                                 struct afs_vlocation, update);
                if (vl->update_at <= xvl->update_at)
                        vl->update_at = xvl->update_at + 1;
                xvl = list_entry(afs_vlocation_updates.next,
                                 struct afs_vlocation, update);
                timeout = xvl->update_at - now;
                if (timeout < 0)
                        timeout = 0;
        } else {
                timeout = afs_vlocation_update_timeout;
        }
 
        ASSERT(list_empty(&vl->update));
 
        list_add_tail(&vl->update, &afs_vlocation_updates);
 
        _debug("timeout %ld", timeout);
        queue_delayed_work(afs_vlocation_update_worker,
                           &afs_vlocation_update, timeout * HZ);
        spin_unlock(&afs_vlocation_updates_lock);
        afs_put_vlocation(vl);
}

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[/] [or1k_soc_on_altera_embedded_dev_kit/] [trunk/] [linux-2.6/] [linux-2.6.24/] [fs/] [afs/] [vlocation.c] - Blame information for rev 17

Line No.	Rev	Author	Line
1	3	xianfeng	`/* AFS volume location management`
2			`*`
3			`* Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.`
4			`* Written by David Howells (dhowells@redhat.com)`
5			`*`
6			`* This program is free software; you can redistribute it and/or`
7			`* modify it under the terms of the GNU General Public License`
8			`* as published by the Free Software Foundation; either version`
9			`* 2 of the License, or (at your option) any later version.`
10			`*/`
11
12			`#include <linux/kernel.h>`
13			`#include <linux/module.h>`
14			`#include <linux/init.h>`
15			`#include <linux/sched.h>`
16			`#include "internal.h"`
17
18			`static unsigned afs_vlocation_timeout = 10; /* volume location timeout in seconds */`
19			`static unsigned afs_vlocation_update_timeout = 10 * 60;`
20
21			`static void afs_vlocation_reaper(struct work_struct *);`
22			`static void afs_vlocation_updater(struct work_struct *);`
23
24			`static LIST_HEAD(afs_vlocation_updates);`
25			`static LIST_HEAD(afs_vlocation_graveyard);`
26			`static DEFINE_SPINLOCK(afs_vlocation_updates_lock);`
27			`static DEFINE_SPINLOCK(afs_vlocation_graveyard_lock);`
28			`static DECLARE_DELAYED_WORK(afs_vlocation_reap, afs_vlocation_reaper);`
29			`static DECLARE_DELAYED_WORK(afs_vlocation_update, afs_vlocation_updater);`
30			`static struct workqueue_struct *afs_vlocation_update_worker;`
31
32			`/*`
33			`* iterate through the VL servers in a cell until one of them admits knowing`
34			`* about the volume in question`
35			`*/`
36			`static int afs_vlocation_access_vl_by_name(struct afs_vlocation *vl,`
37			`struct key *key,`
38			`struct afs_cache_vlocation *vldb)`
39			`{`
40			`struct afs_cell *cell = vl->cell;`
41			`struct in_addr addr;`
42			`int count, ret;`
43
44			`_enter("%s,%s", cell->name, vl->vldb.name);`
45
46			`down_write(&vl->cell->vl_sem);`
47			`ret = -ENOMEDIUM;`
48			`for (count = cell->vl_naddrs; count > 0; count--) {`
49			`addr = cell->vl_addrs[cell->vl_curr_svix];`
50
51			`_debug("CellServ[%hu]: %08x", cell->vl_curr_svix, addr.s_addr);`
52
53			`/* attempt to access the VL server */`
54			`ret = afs_vl_get_entry_by_name(&addr, key, vl->vldb.name, vldb,`
55			`&afs_sync_call);`
56			`switch (ret) {`
57			`case 0:`
58			`goto out;`
59			`case -ENOMEM:`
60			`case -ENONET:`
61			`case -ENETUNREACH:`
62			`case -EHOSTUNREACH:`
63			`case -ECONNREFUSED:`
64			`if (ret == -ENOMEM \|\| ret == -ENONET)`
65			`goto out;`
66			`goto rotate;`
67			`case -ENOMEDIUM:`
68			`goto out;`
69			`default:`
70			`ret = -EIO;`
71			`goto rotate;`
72			`}`
73
74			`/* rotate the server records upon lookup failure */`
75			`rotate:`
76			`cell->vl_curr_svix++;`
77			`cell->vl_curr_svix %= cell->vl_naddrs;`
78			`}`
79
80			`out:`
81			`up_write(&vl->cell->vl_sem);`
82			`_leave(" = %d", ret);`
83			`return ret;`
84			`}`
85
86			`/*`
87			`* iterate through the VL servers in a cell until one of them admits knowing`
88			`* about the volume in question`
89			`*/`
90			`static int afs_vlocation_access_vl_by_id(struct afs_vlocation *vl,`
91			`struct key *key,`
92			`afs_volid_t volid,`
93			`afs_voltype_t voltype,`
94			`struct afs_cache_vlocation *vldb)`
95			`{`
96			`struct afs_cell *cell = vl->cell;`
97			`struct in_addr addr;`
98			`int count, ret;`
99
100			`_enter("%s,%x,%d,", cell->name, volid, voltype);`
101
102			`down_write(&vl->cell->vl_sem);`
103			`ret = -ENOMEDIUM;`
104			`for (count = cell->vl_naddrs; count > 0; count--) {`
105			`addr = cell->vl_addrs[cell->vl_curr_svix];`
106
107			`_debug("CellServ[%hu]: %08x", cell->vl_curr_svix, addr.s_addr);`
108
109			`/* attempt to access the VL server */`
110			`ret = afs_vl_get_entry_by_id(&addr, key, volid, voltype, vldb,`
111			`&afs_sync_call);`
112			`switch (ret) {`
113			`case 0:`
114			`goto out;`
115			`case -ENOMEM:`
116			`case -ENONET:`
117			`case -ENETUNREACH:`
118			`case -EHOSTUNREACH:`
119			`case -ECONNREFUSED:`
120			`if (ret == -ENOMEM \|\| ret == -ENONET)`
121			`goto out;`
122			`goto rotate;`
123			`case -EBUSY:`
124			`vl->upd_busy_cnt++;`
125			`if (vl->upd_busy_cnt <= 3) {`
126			`if (vl->upd_busy_cnt > 1) {`
127			`/* second+ BUSY - sleep a little bit */`
128			`set_current_state(TASK_UNINTERRUPTIBLE);`
129			`schedule_timeout(1);`
130			`__set_current_state(TASK_RUNNING);`
131			`}`
132			`continue;`
133			`}`
134			`break;`
135			`case -ENOMEDIUM:`
136			`vl->upd_rej_cnt++;`
137			`goto rotate;`
138			`default:`
139			`ret = -EIO;`
140			`goto rotate;`
141			`}`
142
143			`/* rotate the server records upon lookup failure */`
144			`rotate:`
145			`cell->vl_curr_svix++;`
146			`cell->vl_curr_svix %= cell->vl_naddrs;`
147			`vl->upd_busy_cnt = 0;`
148			`}`
149
150			`out:`
151			`if (ret < 0 && vl->upd_rej_cnt > 0) {`
152			`printk(KERN_NOTICE "kAFS:"`
153			`" Active volume no longer valid '%s'\n",`
154			`vl->vldb.name);`
155			`vl->valid = 0;`
156			`ret = -ENOMEDIUM;`
157			`}`
158
159			`up_write(&vl->cell->vl_sem);`
160			`_leave(" = %d", ret);`
161			`return ret;`
162			`}`
163
164			`/*`
165			`* allocate a volume location record`
166			`*/`
167			`static struct afs_vlocation afs_vlocation_alloc(struct afs_cell cell,`
168			`const char *name,`
169			`size_t namesz)`
170			`{`
171			`struct afs_vlocation *vl;`
172
173			`vl = kzalloc(sizeof(struct afs_vlocation), GFP_KERNEL);`
174			`if (vl) {`
175			`vl->cell = cell;`
176			`vl->state = AFS_VL_NEW;`
177			`atomic_set(&vl->usage, 1);`
178			`INIT_LIST_HEAD(&vl->link);`
179			`INIT_LIST_HEAD(&vl->grave);`
180			`INIT_LIST_HEAD(&vl->update);`
181			`init_waitqueue_head(&vl->waitq);`
182			`spin_lock_init(&vl->lock);`
183			`memcpy(vl->vldb.name, name, namesz);`
184			`}`
185
186			`_leave(" = %p", vl);`
187			`return vl;`
188			`}`
189
190			`/*`
191			`* update record if we found it in the cache`
192			`*/`
193			`static int afs_vlocation_update_record(struct afs_vlocation *vl,`
194			`struct key *key,`
195			`struct afs_cache_vlocation *vldb)`
196			`{`
197			`afs_voltype_t voltype;`
198			`afs_volid_t vid;`
199			`int ret;`
200
201			`/* try to look up a cached volume in the cell VL databases by ID */`
202			`_debug("Locally Cached: %s %02x { %08x(%x) %08x(%x) %08x(%x) }",`
203			`vl->vldb.name,`
204			`vl->vldb.vidmask,`
205			`ntohl(vl->vldb.servers[0].s_addr),`
206			`vl->vldb.srvtmask[0],`
207			`ntohl(vl->vldb.servers[1].s_addr),`
208			`vl->vldb.srvtmask[1],`
209			`ntohl(vl->vldb.servers[2].s_addr),`
210			`vl->vldb.srvtmask[2]);`
211
212			`_debug("Vids: %08x %08x %08x",`
213			`vl->vldb.vid[0],`
214			`vl->vldb.vid[1],`
215			`vl->vldb.vid[2]);`
216
217			`if (vl->vldb.vidmask & AFS_VOL_VTM_RW) {`
218			`vid = vl->vldb.vid[0];`
219			`voltype = AFSVL_RWVOL;`
220			`} else if (vl->vldb.vidmask & AFS_VOL_VTM_RO) {`
221			`vid = vl->vldb.vid[1];`
222			`voltype = AFSVL_ROVOL;`
223			`} else if (vl->vldb.vidmask & AFS_VOL_VTM_BAK) {`
224			`vid = vl->vldb.vid[2];`
225			`voltype = AFSVL_BACKVOL;`
226			`} else {`
227			`BUG();`
228			`vid = 0;`
229			`voltype = 0;`
230			`}`
231
232			`/* contact the server to make sure the volume is still available`
233			`* - TODO: need to handle disconnected operation here`
234			`*/`
235			`ret = afs_vlocation_access_vl_by_id(vl, key, vid, voltype, vldb);`
236			`switch (ret) {`
237			`/* net error */`
238			`default:`
239			`printk(KERN_WARNING "kAFS:"`
240			`" failed to update volume '%s' (%x) up in '%s': %d\n",`
241			`vl->vldb.name, vid, vl->cell->name, ret);`
242			`_leave(" = %d", ret);`
243			`return ret;`
244
245			`/* pulled from local cache into memory */`
246			`case 0:`
247			`_leave(" = 0");`
248			`return 0;`
249
250			`/* uh oh... looks like the volume got deleted */`
251			`case -ENOMEDIUM:`
252			`printk(KERN_ERR "kAFS:"`
253			`" volume '%s' (%x) does not exist '%s'\n",`
254			`vl->vldb.name, vid, vl->cell->name);`
255
256			`/* TODO: make existing record unavailable */`
257			`_leave(" = %d", ret);`
258			`return ret;`
259			`}`
260			`}`
261
262			`/*`
263			`* apply the update to a VL record`
264			`*/`
265			`static void afs_vlocation_apply_update(struct afs_vlocation *vl,`
266			`struct afs_cache_vlocation *vldb)`
267			`{`
268			`_debug("Done VL Lookup: %s %02x { %08x(%x) %08x(%x) %08x(%x) }",`
269			`vldb->name, vldb->vidmask,`
270			`ntohl(vldb->servers[0].s_addr), vldb->srvtmask[0],`
271			`ntohl(vldb->servers[1].s_addr), vldb->srvtmask[1],`
272			`ntohl(vldb->servers[2].s_addr), vldb->srvtmask[2]);`
273
274			`_debug("Vids: %08x %08x %08x",`
275			`vldb->vid[0], vldb->vid[1], vldb->vid[2]);`
276
277			`if (strcmp(vldb->name, vl->vldb.name) != 0)`
278			`printk(KERN_NOTICE "kAFS:"`
279			`" name of volume '%s' changed to '%s' on server\n",`
280			`vl->vldb.name, vldb->name);`
281
282			`vl->vldb = *vldb;`
283
284			`#ifdef AFS_CACHING_SUPPORT`
285			`/* update volume entry in local cache */`
286			`cachefs_update_cookie(vl->cache);`
287			`#endif`
288			`}`
289
290			`/*`
291			`* fill in a volume location record, consulting the cache and the VL server`
292			`* both`
293			`*/`
294			`static int afs_vlocation_fill_in_record(struct afs_vlocation *vl,`
295			`struct key *key)`
296			`{`
297			`struct afs_cache_vlocation vldb;`
298			`int ret;`
299
300			`_enter("");`
301
302			`ASSERTCMP(vl->valid, ==, 0);`
303
304			`memset(&vldb, 0, sizeof(vldb));`
305
306			`/* see if we have an in-cache copy (will set vl->valid if there is) */`
307			`#ifdef AFS_CACHING_SUPPORT`
308			`cachefs_acquire_cookie(cell->cache,`
309			`&afs_volume_cache_index_def,`
310			`vlocation,`
311			`&vl->cache);`
312			`#endif`
313
314			`if (vl->valid) {`
315			`/* try to update a known volume in the cell VL databases by`
316			`* ID as the name may have changed */`
317			`_debug("found in cache");`
318			`ret = afs_vlocation_update_record(vl, key, &vldb);`
319			`} else {`
320			`/* try to look up an unknown volume in the cell VL databases by`
321			`* name */`
322			`ret = afs_vlocation_access_vl_by_name(vl, key, &vldb);`
323			`if (ret < 0) {`
324			`printk("kAFS: failed to locate '%s' in cell '%s'\n",`
325			`vl->vldb.name, vl->cell->name);`
326			`return ret;`
327			`}`
328			`}`
329
330			`afs_vlocation_apply_update(vl, &vldb);`
331			`_leave(" = 0");`
332			`return 0;`
333			`}`
334
335			`/*`
336			`* queue a vlocation record for updates`
337			`*/`
338			`static void afs_vlocation_queue_for_updates(struct afs_vlocation *vl)`
339			`{`
340			`struct afs_vlocation *xvl;`
341
342			`/* wait at least 10 minutes before updating... */`
343			`vl->update_at = get_seconds() + afs_vlocation_update_timeout;`
344
345			`spin_lock(&afs_vlocation_updates_lock);`
346
347			`if (!list_empty(&afs_vlocation_updates)) {`
348			`/* ... but wait at least 1 second more than the newest record`
349			`* already queued so that we don't spam the VL server suddenly`
350			`* with lots of requests`
351			`*/`
352			`xvl = list_entry(afs_vlocation_updates.prev,`
353			`struct afs_vlocation, update);`
354			`if (vl->update_at <= xvl->update_at)`
355			`vl->update_at = xvl->update_at + 1;`
356			`} else {`
357			`queue_delayed_work(afs_vlocation_update_worker,`
358			`&afs_vlocation_update,`
359			`afs_vlocation_update_timeout * HZ);`
360			`}`
361
362			`list_add_tail(&vl->update, &afs_vlocation_updates);`
363			`spin_unlock(&afs_vlocation_updates_lock);`
364			`}`
365
366			`/*`
367			`* lookup volume location`
368			`* - iterate through the VL servers in a cell until one of them admits knowing`
369			`* about the volume in question`
370			`* - lookup in the local cache if not able to find on the VL server`
371			`* - insert/update in the local cache if did get a VL response`
372			`*/`
373			`struct afs_vlocation afs_vlocation_lookup(struct afs_cell cell,`
374			`struct key *key,`
375			`const char *name,`
376			`size_t namesz)`
377			`{`
378			`struct afs_vlocation *vl;`
379			`int ret;`
380
381			`_enter("{%s},{%x},%.s,%zu",`
382			`cell->name, key_serial(key),`
383			`(int) namesz, (int) namesz, name, namesz);`
384
385			`if (namesz >= sizeof(vl->vldb.name)) {`
386			`_leave(" = -ENAMETOOLONG");`
387			`return ERR_PTR(-ENAMETOOLONG);`
388			`}`
389
390			`/* see if we have an in-memory copy first */`
391			`down_write(&cell->vl_sem);`
392			`spin_lock(&cell->vl_lock);`
393			`list_for_each_entry(vl, &cell->vl_list, link) {`
394			`if (vl->vldb.name[namesz] != '\0')`
395			`continue;`
396			`if (memcmp(vl->vldb.name, name, namesz) == 0)`
397			`goto found_in_memory;`
398			`}`
399			`spin_unlock(&cell->vl_lock);`
400
401			`/* not in the cell's in-memory lists - create a new record */`
402			`vl = afs_vlocation_alloc(cell, name, namesz);`
403			`if (!vl) {`
404			`up_write(&cell->vl_sem);`
405			`return ERR_PTR(-ENOMEM);`
406			`}`
407
408			`afs_get_cell(cell);`
409
410			`list_add_tail(&vl->link, &cell->vl_list);`
411			`vl->state = AFS_VL_CREATING;`
412			`up_write(&cell->vl_sem);`
413
414			`fill_in_record:`
415			`ret = afs_vlocation_fill_in_record(vl, key);`
416			`if (ret < 0)`
417			`goto error_abandon;`
418			`spin_lock(&vl->lock);`
419			`vl->state = AFS_VL_VALID;`
420			`spin_unlock(&vl->lock);`
421			`wake_up(&vl->waitq);`
422
423			`/* schedule for regular updates */`
424			`afs_vlocation_queue_for_updates(vl);`
425			`goto success;`
426
427			`found_in_memory:`
428			`/* found in memory */`
429			`_debug("found in memory");`
430			`atomic_inc(&vl->usage);`
431			`spin_unlock(&cell->vl_lock);`
432			`if (!list_empty(&vl->grave)) {`
433			`spin_lock(&afs_vlocation_graveyard_lock);`
434			`list_del_init(&vl->grave);`
435			`spin_unlock(&afs_vlocation_graveyard_lock);`
436			`}`
437			`up_write(&cell->vl_sem);`
438
439			`/* see if it was an abandoned record that we might try filling in */`
440			`spin_lock(&vl->lock);`
441			`while (vl->state != AFS_VL_VALID) {`
442			`afs_vlocation_state_t state = vl->state;`
443
444			`_debug("invalid [state %d]", state);`
445
446			`if (state == AFS_VL_NEW \|\| state == AFS_VL_NO_VOLUME) {`
447			`vl->state = AFS_VL_CREATING;`
448			`spin_unlock(&vl->lock);`
449			`goto fill_in_record;`
450			`}`
451
452			`/* must now wait for creation or update by someone else to`
453			`* complete */`
454			`_debug("wait");`
455
456			`spin_unlock(&vl->lock);`
457			`ret = wait_event_interruptible(vl->waitq,`
458			`vl->state == AFS_VL_NEW \|\|`
459			`vl->state == AFS_VL_VALID \|\|`
460			`vl->state == AFS_VL_NO_VOLUME);`
461			`if (ret < 0)`
462			`goto error;`
463			`spin_lock(&vl->lock);`
464			`}`
465			`spin_unlock(&vl->lock);`
466
467			`success:`
468			`_leave(" = %p",vl);`
469			`return vl;`
470
471			`error_abandon:`
472			`spin_lock(&vl->lock);`
473			`vl->state = AFS_VL_NEW;`
474			`spin_unlock(&vl->lock);`
475			`wake_up(&vl->waitq);`
476			`error:`
477			`ASSERT(vl != NULL);`
478			`afs_put_vlocation(vl);`
479			`_leave(" = %d", ret);`
480			`return ERR_PTR(ret);`
481			`}`
482
483			`/*`
484			`* finish using a volume location record`
485			`*/`
486			`void afs_put_vlocation(struct afs_vlocation *vl)`
487			`{`
488			`if (!vl)`
489			`return;`
490
491			`_enter("%s", vl->vldb.name);`
492
493			`ASSERTCMP(atomic_read(&vl->usage), >, 0);`
494
495			`if (likely(!atomic_dec_and_test(&vl->usage))) {`
496			`_leave("");`
497			`return;`
498			`}`
499
500			`spin_lock(&afs_vlocation_graveyard_lock);`
501			`if (atomic_read(&vl->usage) == 0) {`
502			`_debug("buried");`
503			`list_move_tail(&vl->grave, &afs_vlocation_graveyard);`
504			`vl->time_of_death = get_seconds();`
505			`schedule_delayed_work(&afs_vlocation_reap,`
506			`afs_vlocation_timeout * HZ);`
507
508			`/* suspend updates on this record */`
509			`if (!list_empty(&vl->update)) {`
510			`spin_lock(&afs_vlocation_updates_lock);`
511			`list_del_init(&vl->update);`
512			`spin_unlock(&afs_vlocation_updates_lock);`
513			`}`
514			`}`
515			`spin_unlock(&afs_vlocation_graveyard_lock);`
516			`_leave(" [killed?]");`
517			`}`
518
519			`/*`
520			`* destroy a dead volume location record`
521			`*/`
522			`static void afs_vlocation_destroy(struct afs_vlocation *vl)`
523			`{`
524			`_enter("%p", vl);`
525
526			`#ifdef AFS_CACHING_SUPPORT`
527			`cachefs_relinquish_cookie(vl->cache, 0);`
528			`#endif`
529
530			`afs_put_cell(vl->cell);`
531			`kfree(vl);`
532			`}`
533
534			`/*`
535			`* reap dead volume location records`
536			`*/`
537			`static void afs_vlocation_reaper(struct work_struct *work)`
538			`{`
539			`LIST_HEAD(corpses);`
540			`struct afs_vlocation *vl;`
541			`unsigned long delay, expiry;`
542			`time_t now;`
543
544			`_enter("");`
545
546			`now = get_seconds();`
547			`spin_lock(&afs_vlocation_graveyard_lock);`
548
549			`while (!list_empty(&afs_vlocation_graveyard)) {`
550			`vl = list_entry(afs_vlocation_graveyard.next,`
551			`struct afs_vlocation, grave);`
552
553			`_debug("check %p", vl);`
554
555			`/* the queue is ordered most dead first */`
556			`expiry = vl->time_of_death + afs_vlocation_timeout;`
557			`if (expiry > now) {`
558			`delay = (expiry - now) * HZ;`
559			`_debug("delay %lu", delay);`
560			`if (!schedule_delayed_work(&afs_vlocation_reap,`
561			`delay)) {`
562			`cancel_delayed_work(&afs_vlocation_reap);`
563			`schedule_delayed_work(&afs_vlocation_reap,`
564			`delay);`
565			`}`
566			`break;`
567			`}`
568
569			`spin_lock(&vl->cell->vl_lock);`
570			`if (atomic_read(&vl->usage) > 0) {`
571			`_debug("no reap");`
572			`list_del_init(&vl->grave);`
573			`} else {`
574			`_debug("reap");`
575			`list_move_tail(&vl->grave, &corpses);`
576			`list_del_init(&vl->link);`
577			`}`
578			`spin_unlock(&vl->cell->vl_lock);`
579			`}`
580
581			`spin_unlock(&afs_vlocation_graveyard_lock);`
582
583			`/* now reap the corpses we've extracted */`
584			`while (!list_empty(&corpses)) {`
585			`vl = list_entry(corpses.next, struct afs_vlocation, grave);`
586			`list_del(&vl->grave);`
587			`afs_vlocation_destroy(vl);`
588			`}`
589
590			`_leave("");`
591			`}`
592
593			`/*`
594			`* initialise the VL update process`
595			`*/`
596			`int __init afs_vlocation_update_init(void)`
597			`{`
598			`afs_vlocation_update_worker =`
599			`create_singlethread_workqueue("kafs_vlupdated");`
600			`return afs_vlocation_update_worker ? 0 : -ENOMEM;`
601			`}`
602
603			`/*`
604			`* discard all the volume location records for rmmod`
605			`*/`
606			`void afs_vlocation_purge(void)`
607			`{`
608			`afs_vlocation_timeout = 0;`
609
610			`spin_lock(&afs_vlocation_updates_lock);`
611			`list_del_init(&afs_vlocation_updates);`
612			`spin_unlock(&afs_vlocation_updates_lock);`
613			`cancel_delayed_work(&afs_vlocation_update);`
614			`queue_delayed_work(afs_vlocation_update_worker,`
615			`&afs_vlocation_update, 0);`
616			`destroy_workqueue(afs_vlocation_update_worker);`
617
618			`cancel_delayed_work(&afs_vlocation_reap);`
619			`schedule_delayed_work(&afs_vlocation_reap, 0);`
620			`}`
621
622			`/*`
623			`* update a volume location`
624			`*/`
625			`static void afs_vlocation_updater(struct work_struct *work)`
626			`{`
627			`struct afs_cache_vlocation vldb;`
628			`struct afs_vlocation vl, xvl;`
629			`time_t now;`
630			`long timeout;`
631			`int ret;`
632
633			`_enter("");`
634
635			`now = get_seconds();`
636
637			`/* find a record to update */`
638			`spin_lock(&afs_vlocation_updates_lock);`
639			`for (;;) {`
640			`if (list_empty(&afs_vlocation_updates)) {`
641			`spin_unlock(&afs_vlocation_updates_lock);`
642			`_leave(" [nothing]");`
643			`return;`
644			`}`
645
646			`vl = list_entry(afs_vlocation_updates.next,`
647			`struct afs_vlocation, update);`
648			`if (atomic_read(&vl->usage) > 0)`
649			`break;`
650			`list_del_init(&vl->update);`
651			`}`
652
653			`timeout = vl->update_at - now;`
654			`if (timeout > 0) {`
655			`queue_delayed_work(afs_vlocation_update_worker,`
656			`&afs_vlocation_update, timeout * HZ);`
657			`spin_unlock(&afs_vlocation_updates_lock);`
658			`_leave(" [nothing]");`
659			`return;`
660			`}`
661
662			`list_del_init(&vl->update);`
663			`atomic_inc(&vl->usage);`
664			`spin_unlock(&afs_vlocation_updates_lock);`
665
666			`/* we can now perform the update */`
667			`_debug("update %s", vl->vldb.name);`
668			`vl->state = AFS_VL_UPDATING;`
669			`vl->upd_rej_cnt = 0;`
670			`vl->upd_busy_cnt = 0;`
671
672			`ret = afs_vlocation_update_record(vl, NULL, &vldb);`
673			`spin_lock(&vl->lock);`
674			`switch (ret) {`
675			`case 0:`
676			`afs_vlocation_apply_update(vl, &vldb);`
677			`vl->state = AFS_VL_VALID;`
678			`break;`
679			`case -ENOMEDIUM:`
680			`vl->state = AFS_VL_VOLUME_DELETED;`
681			`break;`
682			`default:`
683			`vl->state = AFS_VL_UNCERTAIN;`
684			`break;`
685			`}`
686			`spin_unlock(&vl->lock);`
687			`wake_up(&vl->waitq);`
688
689			`/* and then reschedule */`
690			`_debug("reschedule");`
691			`vl->update_at = get_seconds() + afs_vlocation_update_timeout;`
692
693			`spin_lock(&afs_vlocation_updates_lock);`
694
695			`if (!list_empty(&afs_vlocation_updates)) {`
696			`/* next update in 10 minutes, but wait at least 1 second more`
697			`* than the newest record already queued so that we don't spam`
698			`* the VL server suddenly with lots of requests`
699			`*/`
700			`xvl = list_entry(afs_vlocation_updates.prev,`
701			`struct afs_vlocation, update);`
702			`if (vl->update_at <= xvl->update_at)`
703			`vl->update_at = xvl->update_at + 1;`
704			`xvl = list_entry(afs_vlocation_updates.next,`
705			`struct afs_vlocation, update);`
706			`timeout = xvl->update_at - now;`
707			`if (timeout < 0)`
708			`timeout = 0;`
709			`} else {`
710			`timeout = afs_vlocation_update_timeout;`
711			`}`
712
713			`ASSERT(list_empty(&vl->update));`
714
715			`list_add_tail(&vl->update, &afs_vlocation_updates);`
716
717			`_debug("timeout %ld", timeout);`
718			`queue_delayed_work(afs_vlocation_update_worker,`
719			`&afs_vlocation_update, timeout * HZ);`
720			`spin_unlock(&afs_vlocation_updates_lock);`
721			`afs_put_vlocation(vl);`
722			`}`