Import Upstream version 1.8.5

[hcoop/debian/openafs.git] / src / viced / callback.c

/*
 * Copyright 2000, International Business Machines Corporation and others.
 * All Rights Reserved.
 *
 * This software has been released under the terms of the IBM Public
 * License.  For details, see the LICENSE file in the top-level source
 * directory or online at http://www.openafs.org/dl/license10.html
 *
 * Portions Copyright (c) 2006 Sine Nomine Associates
 */

/*
 * NEW callback package callback.c (replaces vicecb.c)
 * Updated call back routines, NOW with:
 *
 *     Faster DeleteVenus (Now called DeleteAllCallBacks)
 *     Call back breaking for volumes
 *     Adaptive timeouts on call backs
 *     Architected for Multi RPC
 *     No locks (currently implicit vnode locks--these will go, to)
 *     Delayed call back when rpc connection down.
 *     Bulk break of delayed call backs when rpc connection
 *         reestablished
 *     Strict limit on number of call backs.
 *
 * InitCallBack(nblocks)
 *     Initialize: nblocks is max number # of file entries + # of callback entries
 *     nblocks must be < 65536
 *     Space used is nblocks*16 bytes
 *     Note that space will be reclaimed by breaking callbacks of old hosts
 *
 * time = AddCallBack(host, fid)
 *     Add a call back.
 *     Returns the expiration time at the workstation.
 *
 * BreakCallBack(host, fid)
 *     Break all call backs for fid, except for the specified host.
 *     Delete all of them.
 *
 * BreakVolumeCallBacksLater(volume)
 *     Break all call backs on volume, using single call to each host
 *     Delete all the call backs.
 *
 * DeleteCallBack(host,fid)
 *     Delete (do not break) single call back for fid.
 *
 * DeleteFileCallBacks(fid)
 *     Delete (do not break) all call backs for fid.
 *
 * DeleteAllCallBacks(host)
 *     Delete (do not break) all call backs for host.
 *
 * CleanupTimedOutCallBacks()
 *     Delete all timed out call back entries
 *     Must be called periodically by file server.
 *
 * BreakDelayedCallBacks(host)
 *     Break all delayed call backs for host.
 *     Returns 1: one or more failed, 0: success.
 *
 * PrintCallBackStats()
 *     Print statistics about call backs to stdout.
 *
 * DumpCallBacks() ---wishful thinking---
 *     Dump call back state to /tmp/callback.state.
 *     This is separately interpretable by the program pcb.
 *
 * Notes:  In general, if a call back to a host doesn't get through,
 * then HostDown, supplied elsewhere, is called.  BreakDelayedCallBacks,
 * however, does not call HostDown, but instead returns an indication of
 * success if all delayed call backs were finally broken.
 *
 * BreakDelayedCallBacks MUST be called at the first sign of activity
 * from the host after HostDown has been called (or a previous
 * BreakDelayedCallBacks failed). The BreakDelayedCallBacks must be
 * allowed to complete before any requests from that host are handled.
 * If BreakDelayedCallBacks fails, then the host should remain
 * down (and the request should be failed).

 * CleanupCallBacks MUST be called periodically by the file server for
 * this package to work correctly.  Every 5 minutes is suggested.
 */

#include <afsconfig.h>
#include <afs/param.h>
#include <afs/stds.h>

#include <roken.h>

#ifdef HAVE_SYS_FILE_H
#include <sys/file.h>
#endif

#include <afs/opr.h>
#include <opr/lock.h>
#include <afs/nfs.h>            /* yuck.  This is an abomination. */
#include <rx/rx.h>
#include <rx/rx_queue.h>
#include <afs/afscbint.h>
#include <afs/afsutil.h>
#include <afs/ihandle.h>
#include <afs/partition.h>
#include <afs/vnode.h>
#include <afs/volume.h>
#include "viced_prototypes.h"
#include "viced.h"

#include <afs/ptclient.h>       /* need definition of prlist for host.h */
#include "host.h"
#include "callback.h"
#ifdef AFS_DEMAND_ATTACH_FS
#include "serialize_state.h"
#endif /* AFS_DEMAND_ATTACH_FS */


extern afsUUID FS_HostUUID;
extern int hostCount;

#ifndef INTERPRET_DUMP
static int ShowProblems = 1;
#endif

struct cbcounters cbstuff;

static struct FileEntry * FE = NULL;    /* don't use FE[0] */
static struct CallBack * CB = NULL;     /* don't use CB[0] */

static struct CallBack * CBfree = NULL;
static struct FileEntry * FEfree = NULL;


/* Time to live for call backs depends upon number of users of the file.
 * TimeOuts is indexed by this number/8 (using TimeOut macro).  Times
 * in this table are for the workstation; server timeouts, add
 * ServerBias */

static int TimeOuts[] = {
/* Note: don't make the first entry larger than 4 hours (see above) */
    4 * 60 * 60,                /* 0-7 users */
    1 * 60 * 60,                /* 8-15 users */
    30 * 60,                    /* 16-23 users */
    15 * 60,                    /* 24-31 users */
    15 * 60,                    /* 32-39 users */
    10 * 60,                    /* 40-47 users */
    10 * 60,                    /* 48-55 users */
    10 * 60,                    /* 56-63 users */
};                              /* Anything more: MinTimeOut */

/* minimum time given for a call back */
#ifndef INTERPRET_DUMP
static int MinTimeOut = (7 * 60);
#endif

/* Heads of CB queues; a timeout index is 1+index into this array */
static afs_uint32 timeout[CB_NUM_TIMEOUT_QUEUES];

static afs_int32 tfirst;        /* cbtime of oldest unexpired call back time queue */


/* 16 byte object get/free routines */
struct object {
    struct object *next;
};

/* Prototypes for static routines */
static struct FileEntry *FindFE(AFSFid * fid);

#ifndef INTERPRET_DUMP
static struct CallBack *iGetCB(int *nused);
static int iFreeCB(struct CallBack *cb, int *nused);
static struct FileEntry *iGetFE(int *nused);
static int iFreeFE(struct FileEntry *fe, int *nused);
static int TAdd(struct CallBack *cb, afs_uint32 * thead);
static int TDel(struct CallBack *cb);
static int HAdd(struct CallBack *cb, struct host *host);
static int HDel(struct CallBack *cb);
static int CDel(struct CallBack *cb, int deletefe);
static int CDelPtr(struct FileEntry *fe, afs_uint32 * cbp,
                   int deletefe);
static afs_uint32 *FindCBPtr(struct FileEntry *fe, struct host *host);
static int FDel(struct FileEntry *fe);
static int AddCallBack1_r(struct host *host, AFSFid * fid, afs_uint32 * thead,
                          int type, int locked);
static void MultiBreakCallBack_r(struct cbstruct cba[], int ncbas,
                                 struct AFSCBFids *afidp);
static int MultiBreakVolumeCallBack_r(struct host *host,
                                      struct VCBParams *parms, int deletefe);
static int MultiBreakVolumeLaterCallBack(struct host *host, void *rock);
static int GetSomeSpace_r(struct host *hostp, int locked);
static int ClearHostCallbacks_r(struct host *hp, int locked);
static int DumpCallBackState_r(void);
#endif

#define GetCB() ((struct CallBack *)iGetCB(&cbstuff.nCBs))
#define GetFE() ((struct FileEntry *)iGetFE(&cbstuff.nFEs))
#define FreeCB(cb) iFreeCB((struct CallBack *)cb, &cbstuff.nCBs)
#define FreeFE(fe) iFreeFE((struct FileEntry *)fe, &cbstuff.nFEs)


/* Other protos - move out sometime */
void PrintCB(struct CallBack *cb, afs_uint32 now);

static afs_uint32 HashTable[FEHASH_SIZE];       /* File entry hash table */

static struct FileEntry *
FindFE(AFSFid * fid)
{
    int hash;
    int fei;
    struct FileEntry *fe;

    hash = FEHash(fid->Volume, fid->Unique);
    for (fei = HashTable[hash]; fei; fei = fe->fnext) {
        fe = itofe(fei);
        if (fe->volid == fid->Volume && fe->unique == fid->Unique
            && fe->vnode == fid->Vnode && (fe->status & FE_LATER) != FE_LATER)
            return fe;
    }
    return 0;
}

#ifndef INTERPRET_DUMP

static struct CallBack *
iGetCB(int *nused)
{
    struct CallBack *ret;

    if ((ret = CBfree)) {
        CBfree = (struct CallBack *)(((struct object *)ret)->next);
        (*nused)++;
    }
    return ret;
}

static int
iFreeCB(struct CallBack *cb, int *nused)
{
    ((struct object *)cb)->next = (struct object *)CBfree;
    CBfree = cb;
    (*nused)--;
    return 0;
}

static struct FileEntry *
iGetFE(int *nused)
{
    struct FileEntry *ret;

    if ((ret = FEfree)) {
        FEfree = (struct FileEntry *)(((struct object *)ret)->next);
        (*nused)++;
    }
    return ret;
}

static int
iFreeFE(struct FileEntry *fe, int *nused)
{
    ((struct object *)fe)->next = (struct object *)FEfree;
    FEfree = fe;
    (*nused)--;
    return 0;
}

/* Add cb to end of specified timeout list */
static int
TAdd(struct CallBack *cb, afs_uint32 * thead)
{
    if (!*thead) {
        (*thead) = cb->tnext = cb->tprev = cbtoi(cb);
    } else {
        struct CallBack *thp = itocb(*thead);

        cb->tprev = thp->tprev;
        cb->tnext = *thead;
        if (thp) {
            if (thp->tprev)
                thp->tprev = (itocb(thp->tprev)->tnext = cbtoi(cb));
            else
                thp->tprev = cbtoi(cb);
        }
    }
    cb->thead = ttoi(thead);
    return 0;
}

/* Delete call back entry from timeout list */
static int
TDel(struct CallBack *cb)
{
    afs_uint32 *thead = itot(cb->thead);

    if (*thead == cbtoi(cb))
        *thead = (*thead == cb->tnext ? 0 : cb->tnext);
    if (itocb(cb->tprev))
        itocb(cb->tprev)->tnext = cb->tnext;
    if (itocb(cb->tnext))
        itocb(cb->tnext)->tprev = cb->tprev;
    return 0;
}

/* Add cb to end of specified host list */
static int
HAdd(struct CallBack *cb, struct host *host)
{
    cb->hhead = h_htoi(host);
    if (!host->z.cblist) {
        host->z.cblist = cb->hnext = cb->hprev = cbtoi(cb);
    } else {
        struct CallBack *fcb = itocb(host->z.cblist);

        cb->hprev = fcb->hprev;
        cb->hnext = cbtoi(fcb);
        fcb->hprev = (itocb(fcb->hprev)->hnext = cbtoi(cb));
    }
    return 0;
}

/* Delete call back entry from host list */
static int
HDel(struct CallBack *cb)
{
    afs_uint32 *hhead = &h_itoh(cb->hhead)->z.cblist;

    if (*hhead == cbtoi(cb))
        *hhead = (*hhead == cb->hnext ? 0 : cb->hnext);
    itocb(cb->hprev)->hnext = cb->hnext;
    itocb(cb->hnext)->hprev = cb->hprev;
    return 0;
}

/* Delete call back entry from fid's chain of cb's */
/* N.B.  This one also deletes the CB, and also possibly parent FE, so
 * make sure that it is not on any other list before calling this
 * routine */
static int
CDel(struct CallBack *cb, int deletefe)
{
    int cbi = cbtoi(cb);
    struct FileEntry *fe = itofe(cb->fhead);
    afs_uint32 *cbp;
    int safety;

    for (safety = 0, cbp = &fe->firstcb; *cbp && *cbp != cbi;
         cbp = &itocb(*cbp)->cnext, safety++) {
        if (safety > cbstuff.nblks + 10) {
            ViceLogThenPanic(0, ("CDel: Internal Error -- shutting down: "
                                 "wanted %d from %d, now at %d\n",
                                 cbi, fe->firstcb, *cbp));
            DumpCallBackState_r();
            ShutDownAndCore(PANIC);
        }
    }
    CDelPtr(fe, cbp, deletefe);
    return 0;
}

/* Same as CDel, but pointer to parent pointer to CB entry is passed,
 * as well as file entry */
/* N.B.  This one also deletes the CB, and also possibly parent FE, so
 * make sure that it is not on any other list before calling this
 * routine */
static int Ccdelpt = 0, CcdelB = 0;

static int
CDelPtr(struct FileEntry *fe, afs_uint32 * cbp,
        int deletefe)
{
    struct CallBack *cb;

    if (!*cbp)
        return 0;
    Ccdelpt++;
    cb = itocb(*cbp);
    if (cb != &CB[*cbp])
        CcdelB++;
    *cbp = cb->cnext;
    FreeCB(cb);
    if ((--fe->ncbs == 0) && deletefe)
        FDel(fe);
    return 0;
}

static afs_uint32 *
FindCBPtr(struct FileEntry *fe, struct host *host)
{
    afs_uint32 hostindex = h_htoi(host);
    struct CallBack *cb;
    afs_uint32 *cbp;
    int safety;

    for (safety = 0, cbp = &fe->firstcb; *cbp; cbp = &cb->cnext, safety++) {
        if (safety > cbstuff.nblks) {
            ViceLog(0, ("FindCBPtr: Internal Error -- shutting down.\n"));
            DumpCallBackState_r();
            ShutDownAndCore(PANIC);
        }
        cb = itocb(*cbp);
        if (cb->hhead == hostindex)
            break;
    }
    return cbp;
}

/* Delete file entry from hash table */
static int
FDel(struct FileEntry *fe)
{
    int fei = fetoi(fe);
    afs_uint32 *p = &HashTable[FEHash(fe->volid, fe->unique)];

    while (*p && *p != fei)
        p = &itofe(*p)->fnext;
    opr_Assert(*p);
    *p = fe->fnext;
    FreeFE(fe);
    return 0;
}

/* initialize the callback package */
int
InitCallBack(int nblks)
{
    opr_Assert(nblks > 0);

    H_LOCK;
    tfirst = CBtime(time(NULL));
    /* N.B. The "-1", below, is because
     * FE[0] and CB[0] are not used--and not allocated */
    FE = calloc(nblks, sizeof(struct FileEntry));
    if (!FE) {
        ViceLogThenPanic(0, ("Failed malloc in InitCallBack\n"));
    }
    FE--;  /* FE[0] is supposed to point to junk */
    cbstuff.nFEs = nblks;
    while (cbstuff.nFEs)
        FreeFE(&FE[cbstuff.nFEs]);      /* This is correct */
    CB = calloc(nblks, sizeof(struct CallBack));
    if (!CB) {
        ViceLogThenPanic(0, ("Failed malloc in InitCallBack\n"));
    }
    CB--;  /* CB[0] is supposed to point to junk */
    cbstuff.nCBs = nblks;
    while (cbstuff.nCBs)
        FreeCB(&CB[cbstuff.nCBs]);      /* This is correct */
    cbstuff.nblks = nblks;
    cbstuff.nbreakers = 0;
    H_UNLOCK;
    return 0;
}

afs_int32
XCallBackBulk_r(struct host * ahost, struct AFSFid * fids, afs_int32 nfids)
{
    struct AFSCallBack tcbs[AFSCBMAX];
    int i;
    struct AFSCBFids tf;
    struct AFSCBs tc;
    int code;
    int j;
    struct rx_connection *cb_conn = NULL;

    rx_SetConnDeadTime(ahost->z.callback_rxcon, 4);
    rx_SetConnHardDeadTime(ahost->z.callback_rxcon, AFS_HARDDEADTIME);

    code = 0;
    j = 0;
    while (nfids > 0) {

        for (i = 0; i < nfids && i < AFSCBMAX; i++) {
            tcbs[i].CallBackVersion = CALLBACK_VERSION;
            tcbs[i].ExpirationTime = 0;
            tcbs[i].CallBackType = CB_DROPPED;
        }
        tf.AFSCBFids_len = i;
        tf.AFSCBFids_val = &(fids[j]);
        nfids -= i;
        j += i;
        tc.AFSCBs_len = i;
        tc.AFSCBs_val = tcbs;

        cb_conn = ahost->z.callback_rxcon;
        rx_GetConnection(cb_conn);
        H_UNLOCK;
        code |= RXAFSCB_CallBack(cb_conn, &tf, &tc);
        rx_PutConnection(cb_conn);
        cb_conn = NULL;
        H_LOCK;
    }

    return code;
}

/* the locked flag tells us if the host entry has already been locked
 * by our parent.  I don't think anybody actually calls us with the
 * host locked, but here's how to make that work:  GetSomeSpace has to
 * change so that it doesn't attempt to lock any hosts < "host".  That
 * means that it might be unable to free any objects, so it has to
 * return an exit status.  If it fails, then AddCallBack1 might fail,
 * as well. If so, the host->ResetDone should probably be set to 0,
 * and we probably don't want to return a callback promise to the
 * cache manager, either. */
int
AddCallBack1(struct host *host, AFSFid * fid, afs_uint32 * thead, int type,
             int locked)
{
    int retVal = 0;
    H_LOCK;
    if (!locked) {
        h_Lock_r(host);
    }
    if (!(host->z.hostFlags & HOSTDELETED))
        retVal = AddCallBack1_r(host, fid, thead, type, 1);

    if (!locked) {
        h_Unlock_r(host);
    }
    H_UNLOCK;
    return retVal;
}

static int
AddCallBack1_r(struct host *host, AFSFid * fid, afs_uint32 * thead, int type,
               int locked)
{
    struct FileEntry *fe;
    struct CallBack *cb = 0, *lastcb = 0;
    struct FileEntry *newfe = 0;
    afs_uint32 time_out = 0;
    afs_uint32 *Thead = thead;
    struct CallBack *newcb = 0;
    int safety;

    cbstuff.AddCallBacks++;

    host->z.Console |= 2;

    /* allocate these guys first, since we can't call the allocator with
     * the host structure locked -- or we might deadlock. However, we have
     * to avoid races with FindFE... */
    while (!(newcb = GetCB())) {
        GetSomeSpace_r(host, locked);
    }
    while (!(newfe = GetFE())) {        /* Get it now, so we don't have to call */
        /* GetSomeSpace with the host locked, later.  This might turn out to */
        /* have been unneccessary, but that's actually kind of unlikely, since */
        /* most files are not shared. */
        GetSomeSpace_r(host, locked);
    }

    if (!locked) {
        h_Lock_r(host);         /* this can yield, so do it before we get any */
        /* fragile info */
        if (host->z.hostFlags & HOSTDELETED) {
            host->z.Console &= ~2;
            h_Unlock_r(host);
            return 0;
        }
    }

    fe = FindFE(fid);
    if (type == CB_NORMAL) {
        time_out =
            TimeCeiling(time(NULL) + TimeOut(fe ? fe->ncbs : 0) +
                        ServerBias);
        Thead = THead(CBtime(time_out));
    } else if (type == CB_VOLUME) {
        time_out = TimeCeiling((60 * 120 + time(NULL)) + ServerBias);
        Thead = THead(CBtime(time_out));
    } else if (type == CB_BULK) {
        /* bulk status can get so many callbacks all at once, and most of them
         * are probably not for things that will be used for long.
         */
        time_out =
            TimeCeiling(time(NULL) + ServerBias +
                        TimeOut(22 + (fe ? fe->ncbs : 0)));
        Thead = THead(CBtime(time_out));
    }

    host->z.Console &= ~2;

    if (!fe) {
        afs_uint32 hash;

        fe = newfe;
        newfe = NULL;
        fe->firstcb = 0;
        fe->volid = fid->Volume;
        fe->vnode = fid->Vnode;
        fe->unique = fid->Unique;
        fe->ncbs = 0;
        fe->status = 0;
        hash = FEHash(fid->Volume, fid->Unique);
        fe->fnext = HashTable[hash];
        HashTable[hash] = fetoi(fe);
    }
    for (safety = 0, lastcb = cb = itocb(fe->firstcb); cb;
         lastcb = cb, cb = itocb(cb->cnext), safety++) {
        if (safety > cbstuff.nblks) {
            ViceLog(0, ("AddCallBack1: Internal Error -- shutting down.\n"));
            DumpCallBackState_r();
            ShutDownAndCore(PANIC);
        }
        if (cb->hhead == h_htoi(host))
            break;
    }
    if (cb) {                   /* Already have call back:  move to new timeout list */
        /* don't change delayed callbacks back to normal ones */
        if (cb->status != CB_DELAYED)
            cb->status = type;
        /* Only move if new timeout is longer */
        if (TNorm(ttoi(Thead)) > TNorm(cb->thead)) {
            TDel(cb);
            TAdd(cb, Thead);
        }
        if (newfe == NULL) {    /* we are using the new FE */
            fe->firstcb = cbtoi(cb);
            fe->ncbs++;
            cb->fhead = fetoi(fe);
        }
    } else {
        cb = newcb;
        newcb = NULL;
        *(lastcb ? &lastcb->cnext : &fe->firstcb) = cbtoi(cb);
        fe->ncbs++;
        cb->cnext = 0;
        cb->fhead = fetoi(fe);
        cb->status = type;
        cb->flags = 0;
        HAdd(cb, host);
        TAdd(cb, Thead);
    }

    /* now free any still-unused callback or host entries */
    if (newcb)
        FreeCB(newcb);
    if (newfe)
        FreeFE(newfe);

    if (!locked)                /* freecb and freefe might(?) yield */
        h_Unlock_r(host);

    if (type == CB_NORMAL || type == CB_VOLUME || type == CB_BULK)
        return time_out - ServerBias;   /* Expires sooner at workstation */

    return 0;
}

static int
CompareCBA(const void *e1, const void *e2)
{
    const struct cbstruct *cba1 = (const struct cbstruct *)e1;
    const struct cbstruct *cba2 = (const struct cbstruct *)e2;
    return ((cba1->hp)->index - (cba2->hp)->index);
}

/* Take an array full of hosts, all held.  Break callbacks to them, and
 * release the holds once you're done.
 * Currently only works for a single Fid in afidp array.
 * If you want to make this work with multiple fids, you need to fix
 * the error handling.  One approach would be to force a reset if a
 * multi-fid call fails, or you could add delayed callbacks for each
 * fid.   You probably also need to sort and remove duplicate hosts.
 * When this is called from the BreakVolumeCallBacks path, it does NOT
 * force a reset if the RPC fails, it just marks the host down and tries
 * to create a delayed callback. */
/* N.B.  be sure that code works when ncbas == 0 */
/* N.B.  requires all the cba[*].hp pointers to be valid... */
/* This routine does not hold a lock on the host for the duration of
 * the BreakCallBack RPC, which is a significant deviation from tradition.
 * It _does_ get a lock on the host before setting VenusDown = 1,
 * which is sufficient only if VenusDown = 0 only happens when the
 * lock is held over the RPC and the subsequent VenusDown == 0
 * wherever that is done. */
static void
MultiBreakCallBack_r(struct cbstruct cba[], int ncbas,
                     struct AFSCBFids *afidp)
{
    int i, j;
    struct rx_connection *conns[MAX_CB_HOSTS];
    static struct AFSCBs tc = { 0, 0 };
    int multi_to_cba_map[MAX_CB_HOSTS];

    opr_Assert(ncbas <= MAX_CB_HOSTS);

    /*
     * When we issue a multi_Rx callback break, we must rx_NewCall a call for
     * each host before we do anything. If there are no call channels
     * available on the conn, we must wait for one of the existing calls to
     * finish. If another thread is breaking callbacks at the same time, it is
     * possible for us to be waiting on NewCall for one of their multi_Rx
     * CallBack calls to finish, but they are waiting on NewCall for one of
     * our calls to finish. So we deadlock.
     *
     * This can be thought of as similar to obtaining multiple locks at the
     * same time. So if we establish an ordering, the possibility of deadlock
     * goes away. Here we provide such an ordering, by sorting our CBAs
     * according to CompareCBA.
     */
    qsort(cba, ncbas, sizeof(struct cbstruct), CompareCBA);

    /* set up conns for multi-call */
    for (i = 0, j = 0; i < ncbas; i++) {
        struct host *thishost = cba[i].hp;
        if (!thishost || (thishost->z.hostFlags & HOSTDELETED)) {
            continue;
        }
        rx_GetConnection(thishost->z.callback_rxcon);
        multi_to_cba_map[j] = i;
        conns[j++] = thishost->z.callback_rxcon;

        rx_SetConnDeadTime(thishost->z.callback_rxcon, 4);
        rx_SetConnHardDeadTime(thishost->z.callback_rxcon, AFS_HARDDEADTIME);
    }

    if (j) {                    /* who knows what multi would do with 0 conns? */
        cbstuff.nbreakers++;
        H_UNLOCK;
        multi_Rx(conns, j) {
            multi_RXAFSCB_CallBack(afidp, &tc);
            if (multi_error) {
                afs_uint32 idx;
                struct host *hp;
                char hoststr[16];

                i = multi_to_cba_map[multi_i];
                hp = cba[i].hp;
                idx = cba[i].thead;

                if (!hp || !idx) {
                    ViceLog(0,
                            ("BCB: INTERNAL ERROR: hp=%p, cba=%p, thead=%u\n",
                             hp, cba, idx));
                } else {
                    /*
                     ** try breaking callbacks on alternate interface addresses
                     */
                    if (MultiBreakCallBackAlternateAddress(hp, afidp)) {
                        if (ShowProblems) {
                            ViceLog(7,
                                    ("BCB: Failed on file %u.%u.%u, "
                                     "Host %p (%s:%d) is down\n",
                                     afidp->AFSCBFids_val->Volume,
                                     afidp->AFSCBFids_val->Vnode,
                                     afidp->AFSCBFids_val->Unique,
                                     hp,
                                     afs_inet_ntoa_r(hp->z.host, hoststr),
                                     ntohs(hp->z.port)));
                        }

                        H_LOCK;
                        h_Lock_r(hp);
                        if (!(hp->z.hostFlags & HOSTDELETED)) {
                            hp->z.hostFlags |= VENUSDOWN;
                            /**
                             * We always go into AddCallBack1_r with the host locked
                             */
                            AddCallBack1_r(hp, afidp->AFSCBFids_val, itot(idx),
                                           CB_DELAYED, 1);
                        }
                        h_Unlock_r(hp);
                        H_UNLOCK;
                    }
                }
            }
        }
        multi_End;
        H_LOCK;
        cbstuff.nbreakers--;
    }

    for (i = 0; i < ncbas; i++) {
        struct host *hp;
        hp = cba[i].hp;
        if (hp) {
            h_Release_r(hp);
        }
    }

    /* H_UNLOCK around this so h_FreeConnection does not deadlock.
       h_FreeConnection should *never* be called on a callback connection,
       but on 10/27/04 a deadlock occurred where it was, when we know why,
       this should be reverted. -- shadow */
    H_UNLOCK;
    for (i = 0; i < j; i++) {
        rx_PutConnection(conns[i]);
    }
    H_LOCK;

    return;
}

/*
 * Break all call backs for fid, except for the specified host (unless flag
 * is true, in which case all get a callback message. Assumption: the specified
 * host is h_Held, by the caller; the others aren't.
 * Specified host may be bogus, that's ok.  This used to check to see if the
 * host was down in two places, once right after the host was h_held, and
 * again after it was locked.  That race condition is incredibly rare and
 * relatively harmless even when it does occur, so we don't check for it now.
 */
/* if flag is true, send a break callback msg to "host", too */
int
BreakCallBack(struct host *xhost, AFSFid * fid, int flag)
{
    struct FileEntry *fe;
    struct CallBack *cb, *nextcb;
    struct cbstruct cba[MAX_CB_HOSTS];
    int ncbas;
    struct AFSCBFids tf;
    int hostindex;
    char hoststr[16];

    if (xhost)
        ViceLog(7,
                ("BCB: BreakCallBack(Host %p all but %s:%d, (%u,%u,%u))\n",
                 xhost, afs_inet_ntoa_r(xhost->z.host, hoststr), ntohs(xhost->z.port),
                 fid->Volume, fid->Vnode, fid->Unique));
    else
        ViceLog(7,
                ("BCB: BreakCallBack(No Host, (%u,%u,%u))\n",
                fid->Volume, fid->Vnode, fid->Unique));

    H_LOCK;
    cbstuff.BreakCallBacks++;
    fe = FindFE(fid);
    if (!fe) {
        goto done;
    }
    hostindex = xhost ? h_htoi(xhost) : 0;
    cb = itocb(fe->firstcb);
    if (!cb || ((fe->ncbs == 1) && (cb->hhead == hostindex) && !flag)) {
        /* the most common case is what follows the || */
        goto done;
    }
    tf.AFSCBFids_len = 1;
    tf.AFSCBFids_val = fid;

    /* Set CBFLAG_BREAKING flag on all CBs we're looking at. We do this so we
     * can loop through all relevant CBs while dropping H_LOCK, and not lose
     * track of which CBs we want to look at. If we look at all CBs over and
     * over again, we can loop indefinitely as new CBs are added. */
    for (; cb; cb = nextcb) {
        nextcb = itocb(cb->cnext);

        if ((cb->hhead != hostindex || flag)
            && (cb->status == CB_BULK || cb->status == CB_NORMAL
                || cb->status == CB_VOLUME)) {
            cb->flags |= CBFLAG_BREAKING;
        }
    }

    cb = itocb(fe->firstcb);
    opr_Assert(cb);

    /* loop through all CBs, only looking at ones with the CBFLAG_BREAKING
     * flag set */
    for (; cb;) {
        for (ncbas = 0; cb && ncbas < MAX_CB_HOSTS; cb = nextcb) {
            nextcb = itocb(cb->cnext);
            if ((cb->flags & CBFLAG_BREAKING)) {
                struct host *thishost = h_itoh(cb->hhead);
                cb->flags &= ~CBFLAG_BREAKING;
                if (!thishost) {
                    ViceLog(0, ("BCB: BOGUS! cb->hhead is NULL!\n"));
                } else if (thishost->z.hostFlags & VENUSDOWN) {
                    ViceLog(7,
                            ("BCB: %p (%s:%d) is down; delaying break call back\n",
                             thishost, afs_inet_ntoa_r(thishost->z.host, hoststr),
                             ntohs(thishost->z.port)));
                    cb->status = CB_DELAYED;
                } else {
                    if (!(thishost->z.hostFlags & HOSTDELETED)) {
                        h_Hold_r(thishost);
                        cba[ncbas].hp = thishost;
                        cba[ncbas].thead = cb->thead;
                        ncbas++;
                    }
                    TDel(cb);
                    HDel(cb);
                    CDel(cb, 1);        /* Usually first; so this delete
                                         * is reasonably inexpensive */
                }
            }
        }

        if (ncbas) {
            MultiBreakCallBack_r(cba, ncbas, &tf);

            /* we need to to all these initializations again because MultiBreakCallBack may block */
            fe = FindFE(fid);
            if (!fe) {
                goto done;
            }
            cb = itocb(fe->firstcb);
            if (!cb || ((fe->ncbs == 1) && (cb->hhead == hostindex) && !flag)) {
                /* the most common case is what follows the || */
                goto done;
            }
        }
    }

  done:
    H_UNLOCK;
    return 0;
}

/* Delete (do not break) single call back for fid */
int
DeleteCallBack(struct host *host, AFSFid * fid)
{
    struct FileEntry *fe;
    afs_uint32 *pcb;
    char hoststr[16];

    H_LOCK;
    cbstuff.DeleteCallBacks++;

    h_Lock_r(host);
    /* do not care if the host has been HOSTDELETED */
    fe = FindFE(fid);
    if (!fe) {
        h_Unlock_r(host);
        H_UNLOCK;
        ViceLog(8,
                ("DCB: No call backs for fid (%u, %u, %u)\n", fid->Volume,
                 fid->Vnode, fid->Unique));
        return 0;
    }
    pcb = FindCBPtr(fe, host);
    if (!*pcb) {
        ViceLog(8,
                ("DCB: No call back for host %p (%s:%d), (%u, %u, %u)\n",
                 host, afs_inet_ntoa_r(host->z.host, hoststr), ntohs(host->z.port),
                 fid->Volume, fid->Vnode, fid->Unique));
        h_Unlock_r(host);
        H_UNLOCK;
        return 0;
    }
    HDel(itocb(*pcb));
    TDel(itocb(*pcb));
    CDelPtr(fe, pcb, 1);
    h_Unlock_r(host);
    H_UNLOCK;
    return 0;
}

/*
 * Delete (do not break) all call backs for fid.  This call doesn't
 * set all of the various host locks, but it shouldn't really matter
 * since we're not adding callbacks, but deleting them.  I'm not sure
 * why it doesn't set the lock, however; perhaps it should.
 */
int
DeleteFileCallBacks(AFSFid * fid)
{
    struct FileEntry *fe;
    struct CallBack *cb;
    afs_uint32 cbi;
    int n;

    H_LOCK;
    cbstuff.DeleteFiles++;
    fe = FindFE(fid);
    if (!fe) {
        H_UNLOCK;
        ViceLog(8,
                ("DF: No fid (%u,%u,%u) to delete\n", fid->Volume, fid->Vnode,
                 fid->Unique));
        return 0;
    }
    for (n = 0, cbi = fe->firstcb; cbi; n++) {
        cb = itocb(cbi);
        cbi = cb->cnext;
        TDel(cb);
        HDel(cb);
        FreeCB(cb);
        fe->ncbs--;
    }
    FDel(fe);
    H_UNLOCK;
    return 0;
}

/* Delete (do not break) all call backs for host.  The host should be
 * locked. */
int
DeleteAllCallBacks_r(struct host *host, int deletefe)
{
    struct CallBack *cb;
    int cbi, first;

    cbstuff.DeleteAllCallBacks++;
    cbi = first = host->z.cblist;
    if (!cbi) {
        ViceLog(8, ("DV: no call backs\n"));
        return 0;
    }
    do {
        cb = itocb(cbi);
        cbi = cb->hnext;
        TDel(cb);
        CDel(cb, deletefe);
    } while (cbi != first);
    host->z.cblist = 0;
    return 0;
}

/*
 * Break all delayed call backs for host.  Returns 1 if all call backs
 * successfully broken; 0 otherwise.  Assumes host is h_Held and h_Locked.
 * Must be called with VenusDown set for this host
 */
int
BreakDelayedCallBacks(struct host *host)
{
    int retVal;
    H_LOCK;
    retVal = BreakDelayedCallBacks_r(host);
    H_UNLOCK;
    return retVal;
}

int
BreakDelayedCallBacks_r(struct host *host)
{
    struct AFSFid fids[AFSCBMAX];
    int cbi, first, nfids;
    struct CallBack *cb;
    int code;
    char hoststr[16];
    struct rx_connection *cb_conn;

    cbstuff.nbreakers++;
    if (!(host->z.hostFlags & RESETDONE) && !(host->z.hostFlags & HOSTDELETED)) {
        host->z.hostFlags &= ~ALTADDR;  /* alternate addresses are invalid */
        cb_conn = host->z.callback_rxcon;
        rx_GetConnection(cb_conn);
        if (host->z.interface) {
            H_UNLOCK;
            code =
                RXAFSCB_InitCallBackState3(cb_conn, &FS_HostUUID);
        } else {
            H_UNLOCK;
            code = RXAFSCB_InitCallBackState(cb_conn);
        }
        rx_PutConnection(cb_conn);
        cb_conn = NULL;
        H_LOCK;
        host->z.hostFlags |= ALTADDR;   /* alternate addresses are valid */
        if (code) {
            if (ShowProblems) {
                ViceLog(0,
                        ("CB: Call back connect back failed (in break delayed) "
                         "for Host %p (%s:%d)\n",
                         host, afs_inet_ntoa_r(host->z.host, hoststr),
                         ntohs(host->z.port)));
            }
            host->z.hostFlags |= VENUSDOWN;
        } else {
            ViceLog(25,
                    ("InitCallBackState success on %p (%s:%d)\n",
                     host, afs_inet_ntoa_r(host->z.host, hoststr),
                     ntohs(host->z.port)));
            /* reset was done successfully */
            host->z.hostFlags |= RESETDONE;
            host->z.hostFlags &= ~VENUSDOWN;
        }
    } else
        while (!(host->z.hostFlags & HOSTDELETED)) {
            nfids = 0;
            host->z.hostFlags &= ~VENUSDOWN;    /* presume up */
            cbi = first = host->z.cblist;
            if (!cbi)
                break;
            do {
                first = host->z.cblist;
                cb = itocb(cbi);
                cbi = cb->hnext;
                if (cb->status == CB_DELAYED) {
                    struct FileEntry *fe = itofe(cb->fhead);
                    fids[nfids].Volume = fe->volid;
                    fids[nfids].Vnode = fe->vnode;
                    fids[nfids].Unique = fe->unique;
                    nfids++;
                    HDel(cb);
                    TDel(cb);
                    CDel(cb, 1);
                }
            } while (cbi && cbi != first && nfids < AFSCBMAX);

            if (nfids == 0) {
                break;
            }

            if (XCallBackBulk_r(host, fids, nfids)) {
                /* Failed, again:  put them back, probably with old
                 * timeout values */
                int i;
                if (ShowProblems) {
                    ViceLog(0,
                            ("CB: XCallBackBulk failed, Host %p (%s:%d); "
                             "callback list follows:\n",
                             host, afs_inet_ntoa_r(host->z.host, hoststr),
                             ntohs(host->z.port)));
                }
                for (i = 0; i < nfids; i++) {
                    if (ShowProblems) {
                        ViceLog(0,
                                ("CB: Host %p (%s:%d), file %u.%u.%u "
                                 "(part of bulk callback)\n",
                                 host, afs_inet_ntoa_r(host->z.host, hoststr),
                                 ntohs(host->z.port), fids[i].Volume,
                                 fids[i].Vnode, fids[i].Unique));
                    }
                    /* used to do this:
                     * AddCallBack1_r(host, &fids[i], itot(thead[i]), CB_DELAYED, 1);
                     * * but it turns out to cause too many tricky locking problems.
                     * * now, if break delayed fails, screw it. */
                }
                host->z.hostFlags |= VENUSDOWN; /* Failed */
                ClearHostCallbacks_r(host, 1 /* locked */ );
                break;
            }
            if (nfids < AFSCBMAX)
                break;
        }

    cbstuff.nbreakers--;
    /* If we succeeded it's always ok to unset HFE_LATER */
    if (!(host->z.hostFlags & VENUSDOWN))
        host->z.hostFlags &= ~HFE_LATER;
    return (host->z.hostFlags & VENUSDOWN);
}

static int
MultiBreakVolumeCallBack_r(struct host *host,
                           struct VCBParams *parms, int deletefe)
{
    char hoststr[16];

    if (host->z.hostFlags & HOSTDELETED)
        return 0;

    if (!(host->z.hostFlags & HCBREAK))
        return 0;               /* host is not flagged to notify */

    if (host->z.hostFlags & VENUSDOWN) {
        h_Lock_r(host);
        /* Do not care if the host is now HOSTDELETED */
        if (ShowProblems) {
            ViceLog(0,
                    ("BVCB: volume callback for Host %p (%s:%d) failed\n",
                     host, afs_inet_ntoa_r(host->z.host, hoststr),
                     ntohs(host->z.port)));
        }
        DeleteAllCallBacks_r(host, deletefe);   /* Delete all callback state
                                                 * rather than attempting to
                                                 * selectively remember to
                                                 * delete the volume callbacks
                                                 * later */
        host->z.hostFlags &= ~(RESETDONE|HCBREAK);      /* Do InitCallBackState when host returns */
        h_Unlock_r(host);
        return 0;
    }
    opr_Assert(parms->ncbas <= MAX_CB_HOSTS);

    /* Do not call MultiBreakCallBack on the current host structure
     ** because it would prematurely release the hold on the host
     */
    if (parms->ncbas == MAX_CB_HOSTS) {
        struct AFSCBFids tf;

        tf.AFSCBFids_len = 1;
        tf.AFSCBFids_val = parms->fid;

        /* this releases all the hosts */
        MultiBreakCallBack_r(parms->cba, parms->ncbas, &tf);

        parms->ncbas = 0;
    }
    parms->cba[parms->ncbas].hp = host;
    parms->cba[(parms->ncbas)++].thead = parms->thead;
    host->z.hostFlags &= ~HCBREAK;

    /* we have more work to do on this host, so make sure we keep a reference
     * to it */
    h_Hold_r(host);

    return 0;
}

static int
MultiBreakVolumeLaterCallBack(struct host *host, void *rock)
{
    struct VCBParams *parms = (struct VCBParams *)rock;
    int retval;
    H_LOCK;
    retval = MultiBreakVolumeCallBack_r(host, parms, 0);
    H_UNLOCK;
    return retval;
}

/*
 * Break all call backs on a single volume.  Don't call this with any
 * hosts h_held.  Note that this routine clears the callbacks before
 * actually breaking them, and that the vnode isn't locked during this
 * operation, so that people might see temporary callback loss while
 * this function is executing.  It is just a temporary state, however,
 * since the callback will be broken later by this same function.
 *
 * Now uses multi-RX for CallBack RPC in a different thread,
 * only marking them here.
 */
extern pthread_cond_t fsync_cond;

int
BreakVolumeCallBacksLater(VolumeId volume)
{
    int hash;
    afs_uint32 *feip;
    struct FileEntry *fe;
    struct CallBack *cb;
    struct host *host;
    int found = 0;

    ViceLog(25, ("Setting later on volume %" AFS_VOLID_FMT "\n",
                 afs_printable_VolumeId_lu(volume)));
    H_LOCK;
    for (hash = 0; hash < FEHASH_SIZE; hash++) {
        for (feip = &HashTable[hash]; (fe = itofe(*feip)) != NULL; ) {
            if (fe->volid == volume) {
                struct CallBack *cbnext;
                for (cb = itocb(fe->firstcb); cb; cb = cbnext) {
                    host = h_itoh(cb->hhead);
                    host->z.hostFlags |= HFE_LATER;
                    cb->status = CB_DELAYED;
                    cbnext = itocb(cb->cnext);
                }
                FSYNC_LOCK;
                fe->status |= FE_LATER;
                FSYNC_UNLOCK;
                found = 1;
            }
            feip = &fe->fnext;
        }
    }
    H_UNLOCK;
    if (!found) {
        /* didn't find any callbacks, so return right away. */
        return 0;
    }

    ViceLog(25, ("Fsync thread wakeup\n"));
    FSYNC_LOCK;
    opr_cv_broadcast(&fsync_cond);
    FSYNC_UNLOCK;
    return 0;
}

int
BreakLaterCallBacks(void)
{
    struct AFSFid fid;
    int hash;
    afs_uint32 *feip;
    struct CallBack *cb;
    struct FileEntry *fe = NULL;
    struct FileEntry *myfe = NULL;
    struct host *host;
    struct VCBParams henumParms;
    unsigned short tthead = 0;  /* zero is illegal value */
    char hoststr[16];

    /* Unchain first */
    ViceLog(25, ("Looking for FileEntries to unchain\n"));
    H_LOCK;
    FSYNC_LOCK;
    /* Pick the first volume we see to clean up */
    fid.Volume = fid.Vnode = fid.Unique = 0;

    for (hash = 0; hash < FEHASH_SIZE; hash++) {
        for (feip = &HashTable[hash]; (fe = itofe(*feip)) != NULL; ) {
            if (fe && (fe->status & FE_LATER)
                && (fid.Volume == 0 || fid.Volume == fe->volid)) {
                /* Ugly, but used to avoid left side casting */
                struct object *tmpfe;
                ViceLog(125,
                        ("Unchaining for %u:%u:%" AFS_VOLID_FMT "\n", fe->vnode,
                         fe->unique, afs_printable_VolumeId_lu(fe->volid)));
                fid.Volume = fe->volid;
                *feip = fe->fnext;
                fe->status &= ~FE_LATER; /* not strictly needed */
                /* Works since volid is deeper than the largest pointer */
                tmpfe = (struct object *)fe;
                tmpfe->next = (struct object *)myfe;
                myfe = fe;
            } else
                feip = &fe->fnext;
        }
    }
    FSYNC_UNLOCK;

    if (!myfe) {
        H_UNLOCK;
        return 0;
    }

    /* loop over FEs from myfe and free/break */
    tthead = 0;
    for (fe = myfe; fe;) {
        struct CallBack *cbnext;
        for (cb = itocb(fe->firstcb); cb; cb = cbnext) {
            cbnext = itocb(cb->cnext);
            host = h_itoh(cb->hhead);
            if (cb->status == CB_DELAYED) {
                if (!(host->z.hostFlags & HOSTDELETED)) {
                    /* mark this host for notification */
                    host->z.hostFlags |= HCBREAK;
                    if (!tthead || (TNorm(tthead) < TNorm(cb->thead))) {
                        tthead = cb->thead;
                    }
                }
                TDel(cb);
                HDel(cb);
                CDel(cb, 0);    /* Don't let CDel clean up the fe */
                /* leave flag for MultiBreakVolumeCallBack to clear */
            } else {
                ViceLog(125,
                        ("Found host %p (%s:%d) non-DELAYED cb for %u:%u:%" AFS_VOLID_FMT "\n",
                         host, afs_inet_ntoa_r(host->z.host, hoststr),
                         ntohs(host->z.port), fe->vnode, fe->unique,
                         afs_printable_VolumeId_lu(fe->volid)));
            }
        }
        myfe = fe;
        fe = (struct FileEntry *)((struct object *)fe)->next;
        FreeFE(myfe);
    }

    if (tthead) {
        ViceLog(125, ("Breaking volume %u\n", fid.Volume));
        henumParms.ncbas = 0;
        henumParms.fid = &fid;
        henumParms.thead = tthead;
        H_UNLOCK;
        h_Enumerate(MultiBreakVolumeLaterCallBack, (char *)&henumParms);
        H_LOCK;
        if (henumParms.ncbas) { /* do left-overs */
            struct AFSCBFids tf;
            tf.AFSCBFids_len = 1;
            tf.AFSCBFids_val = &fid;

            MultiBreakCallBack_r(henumParms.cba, henumParms.ncbas, &tf);
            henumParms.ncbas = 0;
        }
    }
    H_UNLOCK;

    /* Arrange to be called again */
    return 1;
}

/*
 * Delete all timed-out call back entries (to be called periodically by file
 * server)
 */
int
CleanupTimedOutCallBacks(void)
{
    H_LOCK;
    CleanupTimedOutCallBacks_r();
    H_UNLOCK;
    return 0;
}

int
CleanupTimedOutCallBacks_r(void)
{
    afs_uint32 now = CBtime(time(NULL));
    afs_uint32 *thead;
    struct CallBack *cb;
    int ntimedout = 0;
    char hoststr[16];

    while (tfirst <= now) {
        int cbi;
        cbi = *(thead = THead(tfirst));
        if (cbi) {
            do {
                cb = itocb(cbi);
                cbi = cb->tnext;
                ViceLog(8,
                        ("CCB: deleting timed out call back %x (%s:%d), (%" AFS_VOLID_FMT ",%u,%u)\n",
                         h_itoh(cb->hhead)->z.host,
                         afs_inet_ntoa_r(h_itoh(cb->hhead)->z.host, hoststr),
                         h_itoh(cb->hhead)->z.port,
                         afs_printable_VolumeId_lu(itofe(cb->fhead)->volid),
                         itofe(cb->fhead)->vnode, itofe(cb->fhead)->unique));
                HDel(cb);
                CDel(cb, 1);
                ntimedout++;
                if (ntimedout > cbstuff.nblks) {
                    ViceLog(0, ("CCB: Internal Error -- shutting down...\n"));
                    DumpCallBackState_r();
                    ShutDownAndCore(PANIC);
                }
            } while (cbi != *thead);
            *thead = 0;
        }
        tfirst++;
    }
    cbstuff.CBsTimedOut += ntimedout;
    ViceLog(7, ("CCB: deleted %d timed out callbacks\n", ntimedout));
    return (ntimedout > 0);
}

/**
 * parameters to pass to lih*_r from h_Enumerate_r when trying to find a host
 * from which to clear callbacks.
 */
struct lih_params {
    /**
     * Points to the least interesting host found; try to clear callbacks on
     * this host after h_Enumerate_r(lih*_r)'ing.
     */
    struct host *lih;

    /**
     * The last host we got from lih*_r, but we couldn't clear its callbacks
     * for some reason. Choose the next-best host after this one (with the
     * current lih*_r, this means to only select hosts that have an ActiveCall
     * newer than lastlih).
     */
    struct host *lastlih;
};

/* Value of host->z.refCount that allows us to reliably infer that
 * host may be held by some other thread */
#define OTHER_MUSTHOLD_LIH 2

/* This version does not allow 'host' to be selected unless its ActiveCall
 * is newer than 'params->lastlih' which is the host with the oldest
 * ActiveCall from the last pass (if it is provided).  We filter out any hosts
 * that are are held by other threads.
 *
 * There is a small problem here, but it may not be easily fixable. Say we
 * select some host A, and give it back to GetSomeSpace_r. GSS_r for some
 * reason cannot clear the callbacks on A, and so calls us again with
 * lastlih = A. Suppose there is another host B that has the same ActiveCall
 * time as A. We will now skip over host B, since
 * 'hostB->z.ActiveCall > hostA->z.ActiveCall' is not true. This could result in
 * us prematurely going to the GSS_r 2nd or 3rd pass, and making us a little
 * inefficient. This should be pretty rare, though, except perhaps in cases
 * with very small numbers of hosts.
 *
 * Also filter out any hosts with HOSTDELETED set. h_Enumerate_r should in
 * theory not give these to us anyway, but be paranoid.
 */
static int
lih0_r(struct host *host, void *rock)
{
    struct lih_params *params = (struct lih_params *)rock;

    /* OTHER_MUSTHOLD_LIH is because the h_Enum loop holds us once */
    if (host->z.cblist
        && (!(host->z.hostFlags & HOSTDELETED))
        && (host->z.refCount < OTHER_MUSTHOLD_LIH)
        && (!params->lih || host->z.ActiveCall < params->lih->z.ActiveCall)
        && (!params->lastlih || host->z.ActiveCall > params->lastlih->z.ActiveCall)) {

        if (params->lih) {
            h_Release_r(params->lih); /* release prev host */
        }

        h_Hold_r(host);
        params->lih = host;
    }
    return 0;
}

/* same as lih0_r, except we do not prevent held hosts from being selected. */
static int
lih1_r(struct host *host, void *rock)
{
    struct lih_params *params = (struct lih_params *)rock;

    if (host->z.cblist
        && (!(host->z.hostFlags & HOSTDELETED))
        && (!params->lih || host->z.ActiveCall < params->lih->z.ActiveCall)
        && (!params->lastlih || host->z.ActiveCall > params->lastlih->z.ActiveCall)) {

        if (params->lih) {
            h_Release_r(params->lih); /* release prev host */
        }

        h_Hold_r(host);
        params->lih = host;
    }
    return 0;
}

/* This could be upgraded to get more space each time */
/* first pass: sequentially find the oldest host which isn't held by
               anyone for which we can clear callbacks;
               skipping 'hostp' */
/* second pass: sequentially find the oldest host regardless of
               whether or not the host is held; skipping 'hostp' */
/* third pass: attempt to clear callbacks from 'hostp' */
/* always called with hostp unlocked */

/* Note: hostlist is ordered most recently created host first and
 * its order has no relationship to the most recently used. */
extern struct host *hostList;
static int
GetSomeSpace_r(struct host *hostp, int locked)
{
    struct host *hp;
    struct lih_params params;
    int i = 0;

    if (cbstuff.GotSomeSpaces == 0) {
        /* only log this once; if GSS is getting called constantly, that's not
         * good but don't make things worse by spamming the log. */
        ViceLog(0, ("We have run out of callback space; forcing callback revocation. "
                    "This suggests the fileserver is configured with insufficient "
                    "callbacks; you probably want to increase the -cb fileserver "
                    "parameter (current setting: %u). The fileserver will continue "
                    "to operate, but this may indicate a severe performance problem\n",
                    cbstuff.nblks));
        ViceLog(0, ("This message is logged at most once; for more information "
                    "see the OpenAFS documentation and fileserver xstat collection 3\n"));
    }

    cbstuff.GotSomeSpaces++;
    ViceLog(5,
            ("GSS: First looking for timed out call backs via CleanupCallBacks\n"));
    if (CleanupTimedOutCallBacks_r()) {
        cbstuff.GSS3++;
        return 0;
    }

    i = 0;
    params.lastlih = NULL;

    do {
        params.lih = NULL;

        h_Enumerate_r(i == 0 ? lih0_r : lih1_r, hostList, &params);

        hp = params.lih;
        if (params.lastlih) {
            h_Release_r(params.lastlih);
            params.lastlih = NULL;
        }

        if (hp) {
            /* note that 'hp' was held by lih*_r; we will need to release it */
            cbstuff.GSS4++;
            if ((hp != hostp) && !ClearHostCallbacks_r(hp, 0 /* not locked or held */ )) {
                h_Release_r(hp);
                return 0;
            }

            params.lastlih = hp;
            /* params.lastlih will be released on the next iteration, after
             * h_Enumerate_r */

        } else {
            /*
             * Next time try getting callbacks from any host even if
             * it's held, since the only other option is starvation for
             * the file server (i.e. until the callback timeout arrives).
             */
            i++;
            params.lastlih = NULL;
            cbstuff.GSS1++;
            ViceLog(5,
                    ("GSS: Try harder for longest inactive host cnt= %d\n",
                     i));
        }
    } while (i < 2);

    /* Could not obtain space from other hosts, clear hostp's callback state */
    cbstuff.GSS2++;
    if (!locked) {
        h_Lock_r(hostp);
    }
    ClearHostCallbacks_r(hostp, 1 /*already locked */ );
    if (!locked) {
        h_Unlock_r(hostp);
    }
    return 0;
}

/* locked - set if caller has already locked the host */
static int
ClearHostCallbacks_r(struct host *hp, int locked)
{
    int code;
    char hoststr[16];
    struct rx_connection *cb_conn = NULL;

    ViceLog(5,
            ("GSS: Delete longest inactive host %p (%s:%d)\n",
             hp, afs_inet_ntoa_r(hp->z.host, hoststr), ntohs(hp->z.port)));

    if ((hp->z.hostFlags & HOSTDELETED)) {
        /* hp could go away after reacquiring H_LOCK in h_NBLock_r, so we can't
         * really use it; its callbacks will get cleared anyway when
         * h_TossStuff_r gets its hands on it */
        return 1;
    }

    h_Hold_r(hp);

    /** Try a non-blocking lock. If the lock is already held return
      * after releasing hold on hp
      */
    if (!locked) {
        if (h_NBLock_r(hp)) {
            h_Release_r(hp);
            return 1;
        }
    }
    if (hp->z.Console & 2) {
        /*
         * If the special console field is set it means that a thread
         * is waiting in AddCallBack1 after it set pointers to the
         * file entry and/or callback entry. Because of the bogus
         * usage of h_hold it won't prevent from another thread, this
         * one, to remove all the callbacks so just to be safe we keep
         * a reference. NOTE, on the last phase we'll free the calling
         * host's callbacks but that's ok...
         */
        cbstuff.GSS5++;
    }
    DeleteAllCallBacks_r(hp, 1);
    if (hp->z.hostFlags & VENUSDOWN) {
        hp->z.hostFlags &= ~RESETDONE;  /* remember that we must do a reset */
    } else if (!(hp->z.hostFlags & HOSTDELETED)) {
        /* host is up, try a call */
        hp->z.hostFlags &= ~ALTADDR;    /* alternate addresses are invalid */
        cb_conn = hp->z.callback_rxcon;
        rx_GetConnection(hp->z.callback_rxcon);
        if (hp->z.interface) {
            H_UNLOCK;
            code =
                RXAFSCB_InitCallBackState3(cb_conn, &FS_HostUUID);
        } else {
            H_UNLOCK;
            code = RXAFSCB_InitCallBackState(cb_conn);
        }
        rx_PutConnection(cb_conn);
        cb_conn = NULL;
        H_LOCK;
        hp->z.hostFlags |= ALTADDR;     /* alternate addresses are valid */
        if (code) {
            /* failed, mark host down and need reset */
            hp->z.hostFlags |= VENUSDOWN;
            hp->z.hostFlags &= ~RESETDONE;
        } else {
            /* reset succeeded, we're done */
            hp->z.hostFlags |= RESETDONE;
        }
    }
    if (!locked)
        h_Unlock_r(hp);
    h_Release_r(hp);

    return 0;
}
#endif /* INTERPRET_DUMP */


int
PrintCallBackStats(void)
{
    fprintf(stderr,
            "%d add CB, %d break CB, %d del CB, %d del FE, %d CB's timed out, %d space reclaim, %d del host\n",
            cbstuff.AddCallBacks, cbstuff.BreakCallBacks,
            cbstuff.DeleteCallBacks, cbstuff.DeleteFiles, cbstuff.CBsTimedOut,
            cbstuff.GotSomeSpaces, cbstuff.DeleteAllCallBacks);
    fprintf(stderr, "%d CBs, %d FEs, (%d of total of %d 16-byte blocks)\n",
            cbstuff.nCBs, cbstuff.nFEs, cbstuff.nCBs + cbstuff.nFEs,
            cbstuff.nblks);
    fprintf(stderr, "%d GSS1, %d GSS2, %d GSS3, %d GSS4, %d GSS5 (internal counters)\n",
            cbstuff.GSS1, cbstuff.GSS2, cbstuff.GSS3, cbstuff.GSS4, cbstuff.GSS5);

    return 0;
}

#define MAGIC 0x12345678        /* To check byte ordering of dump when it is read in */
#define MAGICV2 0x12345679      /* To check byte ordering & version of dump when it is read in */


#ifndef INTERPRET_DUMP

#ifdef AFS_DEMAND_ATTACH_FS
/*
 * demand attach fs
 * callback state serialization
 */
static int cb_stateSaveTimeouts(struct fs_dump_state * state);
static int cb_stateSaveFEHash(struct fs_dump_state * state);
static int cb_stateSaveFEs(struct fs_dump_state * state);
static int cb_stateSaveFE(struct fs_dump_state * state, struct FileEntry * fe);
static int cb_stateRestoreTimeouts(struct fs_dump_state * state);
static int cb_stateRestoreFEHash(struct fs_dump_state * state);
static int cb_stateRestoreFEs(struct fs_dump_state * state);
static int cb_stateRestoreFE(struct fs_dump_state * state);
static int cb_stateRestoreCBs(struct fs_dump_state * state, struct FileEntry * fe,
                              struct iovec * iov, int niovecs);

static int cb_stateVerifyFEHash(struct fs_dump_state * state);
static int cb_stateVerifyFE(struct fs_dump_state * state, struct FileEntry * fe);
static int cb_stateVerifyFCBList(struct fs_dump_state * state, struct FileEntry * fe);
static int cb_stateVerifyTimeoutQueues(struct fs_dump_state * state);

static int cb_stateFEToDiskEntry(struct FileEntry *, struct FEDiskEntry *);
static int cb_stateDiskEntryToFE(struct fs_dump_state * state,
                                 struct FEDiskEntry *, struct FileEntry *);

static int cb_stateCBToDiskEntry(struct CallBack *, struct CBDiskEntry *);
static int cb_stateDiskEntryToCB(struct fs_dump_state * state,
                                 struct CBDiskEntry *, struct CallBack *);

static int cb_stateFillHeader(struct callback_state_header * hdr);
static int cb_stateCheckHeader(struct callback_state_header * hdr);

static int cb_stateAllocMap(struct fs_dump_state * state);

int
cb_stateSave(struct fs_dump_state * state)
{
    int ret = 0;

    AssignInt64(state->eof_offset, &state->hdr->cb_offset);

    /* invalidate callback state header */
    memset(state->cb_hdr, 0, sizeof(struct callback_state_header));
    if (fs_stateWriteHeader(state, &state->hdr->cb_offset, state->cb_hdr,
                            sizeof(struct callback_state_header))) {
        ret = 1;
        goto done;
    }

    fs_stateIncEOF(state, sizeof(struct callback_state_header));

    /* dump timeout state */
    if (cb_stateSaveTimeouts(state)) {
        ret = 1;
        goto done;
    }

    /* dump fe hashtable state */
    if (cb_stateSaveFEHash(state)) {
        ret = 1;
        goto done;
    }

    /* dump callback state */
    if (cb_stateSaveFEs(state)) {
        ret = 1;
        goto done;
    }

    /* write the callback state header to disk */
    cb_stateFillHeader(state->cb_hdr);
    if (fs_stateWriteHeader(state, &state->hdr->cb_offset, state->cb_hdr,
                            sizeof(struct callback_state_header))) {
        ret = 1;
        goto done;
    }

 done:
    return ret;
}

int
cb_stateRestore(struct fs_dump_state * state)
{
    int ret = 0;

    if (fs_stateReadHeader(state, &state->hdr->cb_offset, state->cb_hdr,
                           sizeof(struct callback_state_header))) {
        ret = 1;
        goto done;
    }

    if (cb_stateCheckHeader(state->cb_hdr)) {
        ret = 1;
        goto done;
    }

    if (cb_stateAllocMap(state)) {
        ret = 1;
        goto done;
    }

    if (cb_stateRestoreTimeouts(state)) {
        ret = 1;
        goto done;
    }

    if (cb_stateRestoreFEHash(state)) {
        ret = 1;
        goto done;
    }

    /* restore FEs and CBs from disk */
    if (cb_stateRestoreFEs(state)) {
        ret = 1;
        goto done;
    }

    /* restore the timeout queue heads */
    tfirst = state->cb_hdr->tfirst;

 done:
    return ret;
}

int
cb_stateRestoreIndices(struct fs_dump_state * state)
{
    int i, ret = 0;
    struct FileEntry * fe;
    struct CallBack * cb;

    /* restore indices in the FileEntry structures */
    for (i = 1; i < state->fe_map.len; i++) {
        if (state->fe_map.entries[i].new_idx) {
            fe = itofe(state->fe_map.entries[i].new_idx);

            /* restore the fe->fnext entry */
            if (fe_OldToNew(state, fe->fnext, &fe->fnext)) {
                ret = 1;
                goto done;
            }

            /* restore the fe->firstcb entry */
            if (cb_OldToNew(state, fe->firstcb, &fe->firstcb)) {
                ret = 1;
                goto done;
            }
        }
    }

    /* restore indices in the CallBack structures */
    for (i = 1; i < state->cb_map.len; i++) {
        if (state->cb_map.entries[i].new_idx) {
            cb = itocb(state->cb_map.entries[i].new_idx);

            /* restore the cb->cnext entry */
            if (cb_OldToNew(state, cb->cnext, &cb->cnext)) {
                ret = 1;
                goto done;
            }

            /* restore the cb->fhead entry */
            if (fe_OldToNew(state, cb->fhead, &cb->fhead)) {
                ret = 1;
                goto done;
            }

            /* restore the cb->hhead entry */
            if (h_OldToNew(state, cb->hhead, &cb->hhead)) {
                ret = 1;
                goto done;
            }

            /* restore the cb->tprev entry */
            if (cb_OldToNew(state, cb->tprev, &cb->tprev)) {
                ret = 1;
                goto done;
            }

            /* restore the cb->tnext entry */
            if (cb_OldToNew(state, cb->tnext, &cb->tnext)) {
                ret = 1;
                goto done;
            }

            /* restore the cb->hprev entry */
            if (cb_OldToNew(state, cb->hprev, &cb->hprev)) {
                ret = 1;
                goto done;
            }

            /* restore the cb->hnext entry */
            if (cb_OldToNew(state, cb->hnext, &cb->hnext)) {
                ret = 1;
                goto done;
            }
        }
    }

    /* restore the timeout queue head indices */
    for (i = 0; i < state->cb_timeout_hdr->records; i++) {
        if (cb_OldToNew(state, timeout[i], &timeout[i])) {
            ret = 1;
            goto done;
        }
    }

    /* restore the FE hash table queue heads */
    for (i = 0; i < state->cb_fehash_hdr->records; i++) {
        if (fe_OldToNew(state, HashTable[i], &HashTable[i])) {
            ret = 1;
            goto done;
        }
    }

 done:
    return ret;
}

int
cb_stateVerify(struct fs_dump_state * state)
{
    int ret = 0;

    if (cb_stateVerifyFEHash(state)) {
        ret = 1;
    }

    if (cb_stateVerifyTimeoutQueues(state)) {
        ret = 1;
    }

    return ret;
}

static int
cb_stateVerifyFEHash(struct fs_dump_state * state)
{
    int ret = 0, i;
    struct FileEntry * fe;
    afs_uint32 fei, chain_len;

    for (i = 0; i < FEHASH_SIZE; i++) {
        chain_len = 0;
        for (fei = HashTable[i], fe = itofe(fei);
             fe;
             fei = fe->fnext, fe = itofe(fei)) {
            if (fei > cbstuff.nblks) {
                ViceLog(0, ("cb_stateVerifyFEHash: error: index out of range (fei=%d)\n", fei));
                ret = 1;
                break;
            }
            if (cb_stateVerifyFE(state, fe)) {
                ret = 1;
            }
            if (chain_len > FS_STATE_FE_MAX_HASH_CHAIN_LEN) {
                ViceLog(0, ("cb_stateVerifyFEHash: error: hash chain %d length exceeds %d; assuming there's a loop\n",
                            i, FS_STATE_FE_MAX_HASH_CHAIN_LEN));
                ret = 1;
                break;
            }
            chain_len++;
        }
    }

    return ret;
}

static int
cb_stateVerifyFE(struct fs_dump_state * state, struct FileEntry * fe)
{
    int ret = 0;

    if ((fe->firstcb && !fe->ncbs) ||
        (!fe->firstcb && fe->ncbs)) {
        ViceLog(0, ("cb_stateVerifyFE: error: fe->firstcb does not agree with fe->ncbs (fei=%lu, fe->firstcb=%lu, fe->ncbs=%lu)\n",
                    afs_printable_uint32_lu(fetoi(fe)),
                    afs_printable_uint32_lu(fe->firstcb),
                    afs_printable_uint32_lu(fe->ncbs)));
        ret = 1;
    }
    if (cb_stateVerifyFCBList(state, fe)) {
        ViceLog(0, ("cb_stateVerifyFE: error: FCBList failed verification (fei=%lu)\n",
                    afs_printable_uint32_lu(fetoi(fe))));
        ret = 1;
    }

    return ret;
}

static int
cb_stateVerifyFCBList(struct fs_dump_state * state, struct FileEntry * fe)
{
    int ret = 0;
    afs_uint32 cbi, fei, chain_len = 0;
    struct CallBack * cb;

    fei = fetoi(fe);

    for (cbi = fe->firstcb, cb = itocb(cbi);
         cb;
         cbi = cb->cnext, cb = itocb(cbi)) {
        if (cbi > cbstuff.nblks) {
            ViceLog(0, ("cb_stateVerifyFCBList: error: list index out of range (cbi=%d, ncbs=%d)\n",
                        cbi, cbstuff.nblks));
            ret = 1;
            goto done;
        }
        if (cb->fhead != fei) {
            ViceLog(0, ("cb_stateVerifyFCBList: error: cb->fhead != fei (fei=%d, cb->fhead=%d)\n",
                        fei, cb->fhead));
            ret = 1;
        }
        if (chain_len > FS_STATE_FCB_MAX_LIST_LEN) {
            ViceLog(0, ("cb_stateVerifyFCBList: error: list length exceeds %d (fei=%d); assuming there's a loop\n",
                        FS_STATE_FCB_MAX_LIST_LEN, fei));
            ret = 1;
            goto done;
        }
        chain_len++;
    }

    if (fe->ncbs != chain_len) {
        ViceLog(0, ("cb_stateVerifyFCBList: error: list length mismatch (len=%d, fe->ncbs=%d)\n",
                    chain_len, fe->ncbs));
        ret = 1;
    }

 done:
    return ret;
}

int
cb_stateVerifyHCBList(struct fs_dump_state * state, struct host * host)
{
    int ret = 0;
    afs_uint32 hi, chain_len, cbi;
    struct CallBack *cb, *ncb;

    hi = h_htoi(host);
    chain_len = 0;

    for (cbi = host->z.cblist, cb = itocb(cbi);
         cb;
         cbi = cb->hnext, cb = ncb) {
        if (chain_len && (host->z.cblist == cbi)) {
            /* we've wrapped around the circular list, and everything looks ok */
            break;
        }
        if (cb->hhead != hi) {
            ViceLog(0, ("cb_stateVerifyHCBList: error: incorrect cb->hhead (cbi=%d, h->index=%d, cb->hhead=%d)\n",
                        cbi, hi, cb->hhead));
            ret = 1;
        }
        if (!cb->hprev || !cb->hnext) {
            ViceLog(0, ("cb_stateVerifyHCBList: error: null index in circular list (cbi=%d, h->index=%d)\n",
                        cbi, hi));
            ret = 1;
            goto done;
        }
        if ((cb->hprev > cbstuff.nblks) ||
            (cb->hnext > cbstuff.nblks)) {
            ViceLog(0, ("cb_stateVerifyHCBList: error: list index out of range (cbi=%d, h->index=%d, cb->hprev=%d, cb->hnext=%d, nCBs=%d)\n",
                        cbi, hi, cb->hprev, cb->hnext, cbstuff.nblks));
            ret = 1;
            goto done;
        }
        ncb = itocb(cb->hnext);
        if (cbi != ncb->hprev) {
            ViceLog(0, ("cb_stateVerifyHCBList: error: corrupt linked list (cbi=%d, h->index=%d)\n",
                        cbi, hi));
            ret = 1;
            goto done;
        }
        if (chain_len > FS_STATE_HCB_MAX_LIST_LEN) {
            ViceLog(0, ("cb_stateVerifyFCBList: error: list length exceeds %d (h->index=%d); assuming there's a loop\n",
                        FS_STATE_HCB_MAX_LIST_LEN, hi));
            ret = 1;
            goto done;
        }
        chain_len++;
    }

 done:
    return ret;
}

static int
cb_stateVerifyTimeoutQueues(struct fs_dump_state * state)
{
    int ret = 0, i;
    afs_uint32 cbi, chain_len;
    struct CallBack *cb, *ncb;

    for (i = 0; i < CB_NUM_TIMEOUT_QUEUES; i++) {
        chain_len = 0;
        for (cbi = timeout[i], cb = itocb(cbi);
             cb;
             cbi = cb->tnext, cb = ncb) {
            if (chain_len && (cbi == timeout[i])) {
                /* we've wrapped around the circular list, and everything looks ok */
                break;
            }
            if (cbi > cbstuff.nblks) {
                ViceLog(0, ("cb_stateVerifyTimeoutQueues: error: list index out of range (cbi=%d, tindex=%d)\n",
                            cbi, i));
                ret = 1;
                break;
            }
            if (itot(cb->thead) != &timeout[i]) {
                ViceLog(0, ("cb_stateVerifyTimeoutQueues: error: cb->thead points to wrong timeout queue (tindex=%d, cbi=%d, cb->thead=%d)\n",
                            i, cbi, cb->thead));
                ret = 1;
            }
            if (!cb->tprev || !cb->tnext) {
                ViceLog(0, ("cb_stateVerifyTimeoutQueues: null index in circular list (cbi=%d, tindex=%d)\n",
                            cbi, i));
                ret = 1;
                break;
            }
            if ((cb->tprev > cbstuff.nblks) ||
                (cb->tnext > cbstuff.nblks)) {
                ViceLog(0, ("cb_stateVerifyTimeoutQueues: list index out of range (cbi=%d, tindex=%d, cb->tprev=%d, cb->tnext=%d, nCBs=%d)\n",
                            cbi, i, cb->tprev, cb->tnext, cbstuff.nblks));
                ret = 1;
                break;
            }
            ncb = itocb(cb->tnext);
            if (cbi != ncb->tprev) {
                ViceLog(0, ("cb_stateVerifyTimeoutQueues: corrupt linked list (cbi=%d, tindex=%d)\n",
                            cbi, i));
                ret = 1;
                break;
            }
            if (chain_len > FS_STATE_TCB_MAX_LIST_LEN) {
                ViceLog(0, ("cb_stateVerifyTimeoutQueues: list length exceeds %d (tindex=%d); assuming there's a loop\n",
                            FS_STATE_TCB_MAX_LIST_LEN, i));
                ret = 1;
                break;
            }
            chain_len++;
        }
    }

    return ret;
}

static int
cb_stateSaveTimeouts(struct fs_dump_state * state)
{
    int ret = 0;
    struct iovec iov[2];

    AssignInt64(state->eof_offset, &state->cb_hdr->timeout_offset);

    memset(state->cb_timeout_hdr, 0, sizeof(struct callback_state_fehash_header));
    state->cb_timeout_hdr->magic = CALLBACK_STATE_TIMEOUT_MAGIC;
    state->cb_timeout_hdr->records = CB_NUM_TIMEOUT_QUEUES;
    state->cb_timeout_hdr->len = sizeof(struct callback_state_timeout_header) +
        (state->cb_timeout_hdr->records * sizeof(afs_uint32));

    iov[0].iov_base = (char *)state->cb_timeout_hdr;
    iov[0].iov_len = sizeof(struct callback_state_timeout_header);
    iov[1].iov_base = (char *)timeout;
    iov[1].iov_len = sizeof(timeout);

    if (fs_stateSeek(state, &state->cb_hdr->timeout_offset)) {
        ret = 1;
        goto done;
    }

    if (fs_stateWriteV(state, iov, 2)) {
        ret = 1;
        goto done;
    }

    fs_stateIncEOF(state, state->cb_timeout_hdr->len);

 done:
    return ret;
}

static int
cb_stateRestoreTimeouts(struct fs_dump_state * state)
{
    int ret = 0, len;

    if (fs_stateReadHeader(state, &state->cb_hdr->timeout_offset,
                           state->cb_timeout_hdr,
                           sizeof(struct callback_state_timeout_header))) {
        ret = 1;
        goto done;
    }

    if (state->cb_timeout_hdr->magic != CALLBACK_STATE_TIMEOUT_MAGIC) {
        ret = 1;
        goto done;
    }
    if (state->cb_timeout_hdr->records != CB_NUM_TIMEOUT_QUEUES) {
        ret = 1;
        goto done;
    }

    len = state->cb_timeout_hdr->records * sizeof(afs_uint32);

    if (state->cb_timeout_hdr->len !=
        (sizeof(struct callback_state_timeout_header) + len)) {
        ret = 1;
        goto done;
    }

    if (fs_stateRead(state, timeout, len)) {
        ret = 1;
        goto done;
    }

 done:
    return ret;
}

static int
cb_stateSaveFEHash(struct fs_dump_state * state)
{
    int ret = 0;
    struct iovec iov[2];

    AssignInt64(state->eof_offset, &state->cb_hdr->fehash_offset);

    memset(state->cb_fehash_hdr, 0, sizeof(struct callback_state_fehash_header));
    state->cb_fehash_hdr->magic = CALLBACK_STATE_FEHASH_MAGIC;
    state->cb_fehash_hdr->records = FEHASH_SIZE;
    state->cb_fehash_hdr->len = sizeof(struct callback_state_fehash_header) +
        (state->cb_fehash_hdr->records * sizeof(afs_uint32));

    iov[0].iov_base = (char *)state->cb_fehash_hdr;
    iov[0].iov_len = sizeof(struct callback_state_fehash_header);
    iov[1].iov_base = (char *)HashTable;
    iov[1].iov_len = sizeof(HashTable);

    if (fs_stateSeek(state, &state->cb_hdr->fehash_offset)) {
        ret = 1;
        goto done;
    }

    if (fs_stateWriteV(state, iov, 2)) {
        ret = 1;
        goto done;
    }

    fs_stateIncEOF(state, state->cb_fehash_hdr->len);

 done:
    return ret;
}

static int
cb_stateRestoreFEHash(struct fs_dump_state * state)
{
    int ret = 0, len;

    if (fs_stateReadHeader(state, &state->cb_hdr->fehash_offset,
                           state->cb_fehash_hdr,
                           sizeof(struct callback_state_fehash_header))) {
        ret = 1;
        goto done;
    }

    if (state->cb_fehash_hdr->magic != CALLBACK_STATE_FEHASH_MAGIC) {
        ret = 1;
        goto done;
    }
    if (state->cb_fehash_hdr->records != FEHASH_SIZE) {
        ret = 1;
        goto done;
    }

    len = state->cb_fehash_hdr->records * sizeof(afs_uint32);

    if (state->cb_fehash_hdr->len !=
        (sizeof(struct callback_state_fehash_header) + len)) {
        ret = 1;
        goto done;
    }

    if (fs_stateRead(state, HashTable, len)) {
        ret = 1;
        goto done;
    }

 done:
    return ret;
}

static int
cb_stateSaveFEs(struct fs_dump_state * state)
{
    int ret = 0;
    int fei, hash;
    struct FileEntry *fe;

    AssignInt64(state->eof_offset, &state->cb_hdr->fe_offset);

    for (hash = 0; hash < FEHASH_SIZE ; hash++) {
        for (fei = HashTable[hash]; fei; fei = fe->fnext) {
            fe = itofe(fei);
            if (cb_stateSaveFE(state, fe)) {
                ret = 1;
                goto done;
            }
        }
    }

 done:
    return ret;
}

static int
cb_stateRestoreFEs(struct fs_dump_state * state)
{
    int count, nFEs, ret = 0;

    nFEs = state->cb_hdr->nFEs;

    for (count = 0; count < nFEs; count++) {
        if (cb_stateRestoreFE(state)) {
            ret = 1;
            goto done;
        }
    }

 done:
    return ret;
}

static int
cb_stateSaveFE(struct fs_dump_state * state, struct FileEntry * fe)
{
    int ret = 0, iovcnt, cbi, written = 0;
    afs_uint32 fei;
    struct callback_state_entry_header hdr;
    struct FEDiskEntry fedsk;
    struct CBDiskEntry cbdsk[16];
    struct iovec iov[16];
    struct CallBack *cb;

    fei = fetoi(fe);
    if (fei > state->cb_hdr->fe_max) {
        state->cb_hdr->fe_max = fei;
    }

    memset(&hdr, 0, sizeof(struct callback_state_entry_header));

    if (cb_stateFEToDiskEntry(fe, &fedsk)) {
        ret = 1;
        goto done;
    }

    iov[0].iov_base = (char *)&hdr;
    iov[0].iov_len = sizeof(hdr);
    iov[1].iov_base = (char *)&fedsk;
    iov[1].iov_len = sizeof(struct FEDiskEntry);
    iovcnt = 2;

    for (cbi = fe->firstcb, cb = itocb(cbi);
         cb != NULL;
         cbi = cb->cnext, cb = itocb(cbi), hdr.nCBs++) {
        if (cbi > state->cb_hdr->cb_max) {
            state->cb_hdr->cb_max = cbi;
        }
        if (cb_stateCBToDiskEntry(cb, &cbdsk[iovcnt])) {
            ret = 1;
            goto done;
        }
        cbdsk[iovcnt].index = cbi;
        iov[iovcnt].iov_base = (char *)&cbdsk[iovcnt];
        iov[iovcnt].iov_len = sizeof(struct CBDiskEntry);
        iovcnt++;
        if ((iovcnt == 16) || (!cb->cnext)) {
            if (fs_stateWriteV(state, iov, iovcnt)) {
                ret = 1;
                goto done;
            }
            written = 1;
            iovcnt = 0;
        }
    }

    hdr.magic = CALLBACK_STATE_ENTRY_MAGIC;
    hdr.len = sizeof(hdr) + sizeof(struct FEDiskEntry) +
        (hdr.nCBs * sizeof(struct CBDiskEntry));

    if (!written) {
        if (fs_stateWriteV(state, iov, iovcnt)) {
            ret = 1;
            goto done;
        }
    } else {
        if (fs_stateWriteHeader(state, &state->eof_offset, &hdr, sizeof(hdr))) {
            ret = 1;
            goto done;
        }
    }

    fs_stateIncEOF(state, hdr.len);

    if (written) {
        if (fs_stateSeek(state, &state->eof_offset)) {
            ret = 1;
            goto done;
        }
    }

    state->cb_hdr->nFEs++;
    state->cb_hdr->nCBs += hdr.nCBs;

 done:
    return ret;
}

static int
cb_stateRestoreFE(struct fs_dump_state * state)
{
    int ret = 0, iovcnt, nCBs;
    struct callback_state_entry_header hdr;
    struct FEDiskEntry fedsk;
    struct CBDiskEntry cbdsk[16];
    struct iovec iov[16];
    struct FileEntry * fe;

    iov[0].iov_base = (char *)&hdr;
    iov[0].iov_len = sizeof(hdr);
    iov[1].iov_base = (char *)&fedsk;
    iov[1].iov_len = sizeof(fedsk);
    iovcnt = 2;

    if (fs_stateReadV(state, iov, iovcnt)) {
        ret = 1;
        goto done;
    }

    if (hdr.magic != CALLBACK_STATE_ENTRY_MAGIC) {
        ret = 1;
        goto done;
    }

    fe = GetFE();
    if (fe == NULL) {
        ViceLog(0, ("cb_stateRestoreFE: ran out of free FileEntry structures\n"));
        ret = 1;
        goto done;
    }

    if (cb_stateDiskEntryToFE(state, &fedsk, fe)) {
        ret = 1;
        goto done;
    }

    if (hdr.nCBs) {
        for (iovcnt = 0, nCBs = 0;
             nCBs < hdr.nCBs;
             nCBs++) {
            iov[iovcnt].iov_base = (char *)&cbdsk[iovcnt];
            iov[iovcnt].iov_len = sizeof(struct CBDiskEntry);
            iovcnt++;
            if ((iovcnt == 16) || (nCBs == hdr.nCBs - 1)) {
                if (fs_stateReadV(state, iov, iovcnt)) {
                    ret = 1;
                    goto done;
                }
                if (cb_stateRestoreCBs(state, fe, iov, iovcnt)) {
                    ret = 1;
                    goto done;
                }
                iovcnt = 0;
            }
        }
    }

 done:
    return ret;
}

static int
cb_stateRestoreCBs(struct fs_dump_state * state, struct FileEntry * fe,
                   struct iovec * iov, int niovecs)
{
    int ret = 0, idx;
    struct CallBack * cb;
    struct CBDiskEntry * cbdsk;

    for (idx = 0; idx < niovecs; idx++) {
        cbdsk = (struct CBDiskEntry *) iov[idx].iov_base;

        if (cbdsk->cb.hhead < state->h_map.len &&
            state->h_map.entries[cbdsk->cb.hhead].valid == FS_STATE_IDX_SKIPPED) {
            continue;
        }

        if ((cb = GetCB()) == NULL) {
            ViceLog(0, ("cb_stateRestoreCBs: ran out of free CallBack structures\n"));
            ret = 1;
            goto done;
        }
        if (cb_stateDiskEntryToCB(state, cbdsk, cb)) {
            ViceLog(0, ("cb_stateRestoreCBs: corrupt CallBack disk entry\n"));
            ret = 1;
            goto done;
        }
    }

 done:
    return ret;
}


static int
cb_stateFillHeader(struct callback_state_header * hdr)
{
    hdr->stamp.magic = CALLBACK_STATE_MAGIC;
    hdr->stamp.version = CALLBACK_STATE_VERSION;
    hdr->tfirst = tfirst;
    return 0;
}

static int
cb_stateCheckHeader(struct callback_state_header * hdr)
{
    int ret = 0;

    if (hdr->stamp.magic != CALLBACK_STATE_MAGIC) {
        ret = 1;
    } else if (hdr->stamp.version != CALLBACK_STATE_VERSION) {
        ret = 1;
    } else if ((hdr->nFEs > cbstuff.nblks) || (hdr->nCBs > cbstuff.nblks)) {
        ViceLog(0, ("cb_stateCheckHeader: saved callback state larger than callback memory allocation\n"));
        ret = 1;
    }
    return ret;
}

/* disk entry conversion routines */
static int
cb_stateFEToDiskEntry(struct FileEntry * in, struct FEDiskEntry * out)
{
    memcpy(&out->fe, in, sizeof(struct FileEntry));
    out->index = fetoi(in);
    return 0;
}

static int
cb_stateDiskEntryToFE(struct fs_dump_state * state,
                      struct FEDiskEntry * in, struct FileEntry * out)
{
    int ret = 0;

    memcpy(out, &in->fe, sizeof(struct FileEntry));

    /* setup FE map entry */
    if (!in->index || (in->index >= state->fe_map.len)) {
        ViceLog(0, ("cb_stateDiskEntryToFE: index (%d) out of range",
                    in->index));
        ret = 1;
        goto done;
    }
    state->fe_map.entries[in->index].valid = FS_STATE_IDX_VALID;
    state->fe_map.entries[in->index].old_idx = in->index;
    state->fe_map.entries[in->index].new_idx = fetoi(out);

 done:
    return ret;
}

static int
cb_stateCBToDiskEntry(struct CallBack * in, struct CBDiskEntry * out)
{
    memcpy(&out->cb, in, sizeof(struct CallBack));
    out->index = cbtoi(in);
    return 0;
}

static int
cb_stateDiskEntryToCB(struct fs_dump_state * state,
                      struct CBDiskEntry * in, struct CallBack * out)
{
    int ret = 0;

    memcpy(out, &in->cb, sizeof(struct CallBack));

    /* setup CB map entry */
    if (!in->index || (in->index >= state->cb_map.len)) {
        ViceLog(0, ("cb_stateDiskEntryToCB: index (%d) out of range\n",
                    in->index));
        ret = 1;
        goto done;
    }
    state->cb_map.entries[in->index].valid = FS_STATE_IDX_VALID;
    state->cb_map.entries[in->index].old_idx = in->index;
    state->cb_map.entries[in->index].new_idx = cbtoi(out);

 done:
    return ret;
}

/* index map routines */
static int
cb_stateAllocMap(struct fs_dump_state * state)
{
    state->fe_map.len = state->cb_hdr->fe_max + 1;
    state->cb_map.len = state->cb_hdr->cb_max + 1;
    state->fe_map.entries = (struct idx_map_entry_t *)
        calloc(state->fe_map.len, sizeof(struct idx_map_entry_t));
    state->cb_map.entries = (struct idx_map_entry_t *)
        calloc(state->cb_map.len, sizeof(struct idx_map_entry_t));
    return ((state->fe_map.entries != NULL) && (state->cb_map.entries != NULL)) ? 0 : 1;
}

int
fe_OldToNew(struct fs_dump_state * state, afs_uint32 old, afs_uint32 * new)
{
    int ret = 0;

    /* FEs use a one-based indexing system, so old==0 implies no mapping */
    if (!old) {
        *new = 0;
        goto done;
    }

    if (old >= state->fe_map.len) {
        ViceLog(0, ("fe_OldToNew: index %d is out of range\n", old));
        ret = 1;
    } else if (state->fe_map.entries[old].valid != FS_STATE_IDX_VALID ||
               state->fe_map.entries[old].old_idx != old) { /* sanity check */
        ViceLog(0, ("fe_OldToNew: index %d points to an invalid FileEntry record\n", old));
        ret = 1;
    } else {
        *new = state->fe_map.entries[old].new_idx;
    }

 done:
    return ret;
}

int
cb_OldToNew(struct fs_dump_state * state, afs_uint32 old, afs_uint32 * new)
{
    int ret = 0;

    /* CBs use a one-based indexing system, so old==0 implies no mapping */
    if (!old) {
        *new = 0;
        goto done;
    }

    if (old >= state->cb_map.len) {
        ViceLog(0, ("cb_OldToNew: index %d is out of range\n", old));
        ret = 1;
    } else if (state->cb_map.entries[old].valid != FS_STATE_IDX_VALID ||
               state->cb_map.entries[old].old_idx != old) { /* sanity check */
        ViceLog(0, ("cb_OldToNew: index %d points to an invalid CallBack record\n", old));
        ret = 1;
    } else {
        *new = state->cb_map.entries[old].new_idx;
    }

 done:
    return ret;
}
#endif /* AFS_DEMAND_ATTACH_FS */

#define DumpBytes(fd,buf,req) if (write(fd, buf, req) < 0) {} /* don't care */

static int
DumpCallBackState_r(void)
{
    int fd, oflag;
    afs_uint32 magic = MAGICV2, now = (afs_int32) time(NULL), freelisthead;

    oflag = O_WRONLY | O_CREAT | O_TRUNC;
#ifdef AFS_NT40_ENV
    oflag |= O_BINARY;
#endif
    fd = open(AFSDIR_SERVER_CBKDUMP_FILEPATH, oflag, 0666);
    if (fd < 0) {
        ViceLog(0,
                ("Couldn't create callback dump file %s\n",
                 AFSDIR_SERVER_CBKDUMP_FILEPATH));
        return 0;
    }
    /*
     * Collect but ignoring the return value of write(2) here,
     * to avoid compiler warnings on some platforms.
     */
    DumpBytes(fd, &magic, sizeof(magic));
    DumpBytes(fd, &now, sizeof(now));
    DumpBytes(fd, &cbstuff, sizeof(cbstuff));
    DumpBytes(fd, TimeOuts, sizeof(TimeOuts));
    DumpBytes(fd, timeout, sizeof(timeout));
    DumpBytes(fd, &tfirst, sizeof(tfirst));
    freelisthead = cbtoi((struct CallBack *)CBfree);
    DumpBytes(fd, &freelisthead, sizeof(freelisthead)); /* This is a pointer */
    freelisthead = fetoi((struct FileEntry *)FEfree);
    DumpBytes(fd, &freelisthead, sizeof(freelisthead)); /* This is a pointer */
    DumpBytes(fd, HashTable, sizeof(HashTable));
    DumpBytes(fd, &CB[1], sizeof(CB[1]) * cbstuff.nblks);       /* CB stuff */
    DumpBytes(fd, &FE[1], sizeof(FE[1]) * cbstuff.nblks);       /* FE stuff */
    close(fd);

    return 0;
}

int
DumpCallBackState(void) {
    int rc;

    H_LOCK;
    rc = DumpCallBackState_r();
    H_UNLOCK;

    return(rc);
}

#endif /* !INTERPRET_DUMP */

#ifdef INTERPRET_DUMP

static void
ReadBytes(int fd, void *buf, size_t req)
{
    ssize_t count;

    count = read(fd, buf, req);
    if (count < 0) {
        perror("read");
        exit(-1);
    } else if (count != req) {
        fprintf(stderr, "read: premature EOF (expected %lu, got %lu)\n",
                (unsigned long)req, (unsigned long)count);
        exit(-1);
    }
}

/* This is only compiled in for the callback analyzer program */
/* Returns the time of the dump */
time_t
ReadDump(char *file, int timebits)
{
    int fd, oflag;
    afs_uint32 magic, freelisthead;
    afs_uint32 now;
    afs_int64 now64;

    oflag = O_RDONLY;
#ifdef AFS_NT40_ENV
    oflag |= O_BINARY;
#endif
    fd = open(file, oflag);
    if (fd < 0) {
        fprintf(stderr, "Couldn't read dump file %s\n", file);
        exit(1);
    }
    ReadBytes(fd, &magic, sizeof(magic));
    if (magic == MAGICV2) {
        timebits = 32;
    } else {
        if (magic != MAGIC) {
            fprintf(stderr,
                    "Magic number of %s is invalid.  You might be trying to\n",
                    file);
            fprintf(stderr,
                    "run this program on a machine type with a different byte ordering.\n");
            exit(1);
        }
    }
    if (timebits == 64) {
        ReadBytes(fd, &now64, sizeof(afs_int64));
        now = (afs_int32) now64;
    } else
        ReadBytes(fd, &now, sizeof(afs_int32));

    ReadBytes(fd, &cbstuff, sizeof(cbstuff));
    ReadBytes(fd, TimeOuts, sizeof(TimeOuts));
    ReadBytes(fd, timeout, sizeof(timeout));
    ReadBytes(fd, &tfirst, sizeof(tfirst));
    ReadBytes(fd, &freelisthead, sizeof(freelisthead));
    CB = ((struct CallBack
           *)(calloc(cbstuff.nblks, sizeof(struct CallBack)))) - 1;
    FE = ((struct FileEntry
           *)(calloc(cbstuff.nblks, sizeof(struct FileEntry)))) - 1;
    CBfree = (struct CallBack *)itocb(freelisthead);
    ReadBytes(fd, &freelisthead, sizeof(freelisthead));
    FEfree = (struct FileEntry *)itofe(freelisthead);
    ReadBytes(fd, HashTable, sizeof(HashTable));
    ReadBytes(fd, &CB[1], sizeof(CB[1]) * cbstuff.nblks);       /* CB stuff */
    ReadBytes(fd, &FE[1], sizeof(FE[1]) * cbstuff.nblks);       /* FE stuff */
    if (close(fd)) {
        perror("Error reading dumpfile");
        exit(1);
    }
    return now;
}

#ifdef AFS_NT40_ENV
#include "AFS_component_version_number.h"
#else
#include "AFS_component_version_number.c"
#endif

static afs_uint32 *cbTrack;

int
main(int argc, char **argv)
{
    int err = 0, cbi = 0, stats = 0, noptions = 0, all = 0, vol = 0, raw = 0;
    static AFSFid fid;
    struct FileEntry *fe;
    struct CallBack *cb;
    time_t now;
    int timebits = 32;

    memset(&fid, 0, sizeof(fid));
    argc--;
    argv++;
    while (argc && **argv == '-') {
        noptions++;
        argc--;
        if (!strcmp(*argv, "-host")) {
            if (argc < 1) {
                err++;
                break;
            }
            argc--;
            cbi = atoi(*++argv);
        } else if (!strcmp(*argv, "-fid")) {
            if (argc < 2) {
                err++;
                break;
            }
            argc -= 3;
            fid.Volume = atoi(*++argv);
            fid.Vnode = atoi(*++argv);
            fid.Unique = atoi(*++argv);
        } else if (!strcmp(*argv, "-time")) {
            fprintf(stderr, "-time not supported\n");
            exit(1);
        } else if (!strcmp(*argv, "-stats")) {
            stats = 1;
        } else if (!strcmp(*argv, "-all")) {
            all = 1;
        } else if (!strcmp(*argv, "-raw")) {
            raw = 1;
        } else if (!strcmp(*argv, "-timebits")) {
            if (argc < 1) {
                err++;
                break;
            }
            argc--;
            timebits = atoi(*++argv);
            if ((timebits != 32)
                && (timebits != 64)
                )
                err++;
        } else if (!strcmp(*argv, "-volume")) {
            if (argc < 1) {
                err++;
                break;
            }
            argc--;
            vol = atoi(*++argv);
        } else
            err++;
        argv++;
    }
    if (err || argc != 1) {
        fprintf(stderr,
                "Usage: cbd [-host cbid] [-fid volume vnode] [-stats] [-all] [-timebits 32"
                "|64"
                "] callbackdumpfile\n");
        fprintf(stderr,
                "[cbid is shown for each host in the hosts.dump file]\n");
        exit(1);
    }
    now = ReadDump(*argv, timebits);
    if (stats || noptions == 0) {
        time_t uxtfirst = UXtime(tfirst), tnow = now;
        printf("The time of the dump was %u %s", (unsigned int) now, ctime(&tnow));
        printf("The last time cleanup ran was %u %s", (unsigned int) uxtfirst,
               ctime(&uxtfirst));
        PrintCallBackStats();
    }

    cbTrack = calloc(cbstuff.nblks, sizeof(cbTrack[0]));

    if (all || vol) {
        int hash;
        afs_uint32 *feip;
        struct CallBack *cb;
        struct FileEntry *fe;

        for (hash = 0; hash < FEHASH_SIZE; hash++) {
            for (feip = &HashTable[hash]; (fe = itofe(*feip));) {
                if (!vol || (fe->volid == vol)) {
                    afs_uint32 fe_i = fetoi(fe);

                    for (cb = itocb(fe->firstcb); cb; cb = itocb(cb->cnext)) {
                        afs_uint32 cb_i = cbtoi(cb);

                        if (cb_i > cbstuff.nblks) {
                            printf("CB index out of range (%u > %d), stopped for this FE\n",
                                cb_i, cbstuff.nblks);
                            break;
                        }

                        if (cbTrack[cb_i]) {
                            printf("CB entry already claimed for FE[%u] (this is FE[%u]), stopped\n",
                                cbTrack[cb_i], fe_i);
                            break;
                        }
                        cbTrack[cb_i] = fe_i;

                        PrintCB(cb, now);
                    }
                    *feip = fe->fnext;
                } else {
                    feip = &fe->fnext;
                }
            }
        }
    }
    if (cbi) {
        afs_uint32 cfirst = cbi;
        do {
            cb = itocb(cbi);
            PrintCB(cb, now);
            cbi = cb->hnext;
        } while (cbi != cfirst);
    }
    if (fid.Volume) {
        fe = FindFE(&fid);
        if (!fe) {
            printf("No callback entries for %u.%u\n", fid.Volume, fid.Vnode);
            exit(1);
        }
        cb = itocb(fe->firstcb);
        while (cb) {
            PrintCB(cb, now);
            cb = itocb(cb->cnext);
        }
    }
    if (raw) {
        afs_int32 *p, i;
        for (i = 1; i < cbstuff.nblks; i++) {
            p = (afs_int32 *) & FE[i];
            printf("%d:%12x%12x%12x%12x\n", i, p[0], p[1], p[2], p[3]);
        }
    }

    free(cbTrack);
    exit(0);
}

void
PrintCB(struct CallBack *cb, afs_uint32 now)
{
    struct FileEntry *fe = itofe(cb->fhead);
    time_t expires = TIndexToTime(cb->thead);

    if (fe == NULL)
        return;

    printf("vol=%" AFS_VOLID_FMT " vn=%u cbs=%d hi=%d st=%d fest=%d, exp in %lu secs at %s",
           afs_printable_VolumeId_lu(fe->volid), fe->vnode, fe->ncbs,
           cb->hhead, cb->status, fe->status, (unsigned long)(expires - now),
           ctime(&expires));
}

#endif

#if     !defined(INTERPRET_DUMP)
/*
** try breaking calbacks on afidp from host. Use multi_rx.
** return 0 on success, non-zero on failure
*/
int
MultiBreakCallBackAlternateAddress(struct host *host, struct AFSCBFids *afidp)
{
    int retVal;
    H_LOCK;
    retVal = MultiBreakCallBackAlternateAddress_r(host, afidp);
    H_UNLOCK;
    return retVal;
}

int
MultiBreakCallBackAlternateAddress_r(struct host *host,
                                     struct AFSCBFids *afidp)
{
    int i, j;
    struct rx_connection **conns;
    struct rx_connection *connSuccess = 0;
    struct AddrPort *interfaces;
    static struct rx_securityClass *sc = 0;
    static struct AFSCBs tc = { 0, 0 };
    char hoststr[16];

    /* nothing more can be done */
    if (!host->z.interface)
        return 1;               /* failure */

    /* the only address is the primary interface */
    if (host->z.interface->numberOfInterfaces <= 1)
        return 1;               /* failure */

    /* initialise a security object only once */
    if (!sc)
        sc = rxnull_NewClientSecurityObject();

    i = host->z.interface->numberOfInterfaces;
    interfaces = calloc(i, sizeof(struct AddrPort));
    conns = calloc(i, sizeof(struct rx_connection *));
    if (!interfaces || !conns) {
        ViceLogThenPanic(0, ("Failed malloc in "
                             "MultiBreakCallBackAlternateAddress_r\n"));
    }

    /* initialize alternate rx connections */
    for (i = 0, j = 0; i < host->z.interface->numberOfInterfaces; i++) {
        /* this is the current primary address */
        if (host->z.host == host->z.interface->interface[i].addr &&
            host->z.port == host->z.interface->interface[i].port)
            continue;

        interfaces[j] = host->z.interface->interface[i];
        conns[j] =
            rx_NewConnection(interfaces[j].addr,
                             interfaces[j].port, 1, sc, 0);
        rx_SetConnDeadTime(conns[j], 2);
        rx_SetConnHardDeadTime(conns[j], AFS_HARDDEADTIME);
        j++;
    }

    opr_Assert(j);                      /* at least one alternate address */
    ViceLog(125,
            ("Starting multibreakcall back on all addr for host %p (%s:%d)\n",
             host, afs_inet_ntoa_r(host->z.host, hoststr), ntohs(host->z.port)));
    H_UNLOCK;
    multi_Rx(conns, j) {
        multi_RXAFSCB_CallBack(afidp, &tc);
        if (!multi_error) {
            /* first success */
            H_LOCK;
            if (host->z.callback_rxcon)
                rx_DestroyConnection(host->z.callback_rxcon);
            host->z.callback_rxcon = conns[multi_i];
            /* add then remove */
            addInterfaceAddr_r(host, interfaces[multi_i].addr,
                                     interfaces[multi_i].port);
            removeInterfaceAddr_r(host, host->z.host, host->z.port);
            host->z.host = interfaces[multi_i].addr;
            host->z.port = interfaces[multi_i].port;
            connSuccess = conns[multi_i];
            rx_SetConnDeadTime(host->z.callback_rxcon, 50);
            rx_SetConnHardDeadTime(host->z.callback_rxcon, AFS_HARDDEADTIME);
            ViceLog(125,
                    ("multibreakcall success with addr %s:%d\n",
                     afs_inet_ntoa_r(interfaces[multi_i].addr, hoststr),
                     ntohs(interfaces[multi_i].port)));
            H_UNLOCK;
            multi_Abort;
        }
    }
    multi_End_Ignore;
    H_LOCK;
    /* Destroy all connections except the one on which we succeeded */
    for (i = 0; i < j; i++)
        if (conns[i] != connSuccess)
            rx_DestroyConnection(conns[i]);

    free(interfaces);
    free(conns);

    if (connSuccess)
        return 0;               /* success */
    else
        return 1;               /* failure */
}


/*
** try multi_RX probes to host.
** return 0 on success, non-0 on failure
*/
int
MultiProbeAlternateAddress_r(struct host *host)
{
    int i, j;
    struct rx_connection **conns;
    struct rx_connection *connSuccess = 0;
    struct AddrPort *interfaces;
    static struct rx_securityClass *sc = 0;
    char hoststr[16];

    /* nothing more can be done */
    if (!host->z.interface)
        return 1;               /* failure */

    /* the only address is the primary interface */
    if (host->z.interface->numberOfInterfaces <= 1)
        return 1;               /* failure */

    /* initialise a security object only once */
    if (!sc)
        sc = rxnull_NewClientSecurityObject();

    i = host->z.interface->numberOfInterfaces;
    interfaces = calloc(i, sizeof(struct AddrPort));
    conns = calloc(i, sizeof(struct rx_connection *));
    if (!interfaces || !conns) {
        ViceLogThenPanic(0, ("Failed malloc in "
                             "MultiProbeAlternateAddress_r\n"));
    }

    /* initialize alternate rx connections */
    for (i = 0, j = 0; i < host->z.interface->numberOfInterfaces; i++) {
        /* this is the current primary address */
        if (host->z.host == host->z.interface->interface[i].addr &&
            host->z.port == host->z.interface->interface[i].port)
            continue;

        interfaces[j] = host->z.interface->interface[i];
        conns[j] =
            rx_NewConnection(interfaces[j].addr,
                             interfaces[j].port, 1, sc, 0);
        rx_SetConnDeadTime(conns[j], 2);
        rx_SetConnHardDeadTime(conns[j], AFS_HARDDEADTIME);
        j++;
    }

    opr_Assert(j);                      /* at least one alternate address */
    ViceLog(125,
            ("Starting multiprobe on all addr for host %p (%s:%d)\n",
             host, afs_inet_ntoa_r(host->z.host, hoststr),
             ntohs(host->z.port)));
    H_UNLOCK;
    multi_Rx(conns, j) {
        multi_RXAFSCB_ProbeUuid(&host->z.interface->uuid);
        if (!multi_error) {
            /* first success */
            H_LOCK;
            if (host->z.callback_rxcon)
                rx_DestroyConnection(host->z.callback_rxcon);
            host->z.callback_rxcon = conns[multi_i];
            /* add then remove */
            addInterfaceAddr_r(host, interfaces[multi_i].addr,
                                     interfaces[multi_i].port);
            removeInterfaceAddr_r(host, host->z.host, host->z.port);
            host->z.host = interfaces[multi_i].addr;
            host->z.port = interfaces[multi_i].port;
            connSuccess = conns[multi_i];
            rx_SetConnDeadTime(host->z.callback_rxcon, 50);
            rx_SetConnHardDeadTime(host->z.callback_rxcon, AFS_HARDDEADTIME);
            ViceLog(125,
                    ("multiprobe success with addr %s:%d\n",
                     afs_inet_ntoa_r(interfaces[multi_i].addr, hoststr),
                     ntohs(interfaces[multi_i].port)));
            H_UNLOCK;
            multi_Abort;
        } else {
            ViceLog(125,
                    ("multiprobe failure with addr %s:%d\n",
                     afs_inet_ntoa_r(interfaces[multi_i].addr, hoststr),
                     ntohs(interfaces[multi_i].port)));

            /* This is less than desirable but its the best we can do.
             * The AFS Cache Manager will return either 0 for a Uuid
             * match and a 1 for a non-match.   If the error is 1 we
             * therefore know that our mapping of IP address to Uuid
             * is wrong.   We should attempt to find the correct
             * Uuid and fix the host tables.
             */
            if (multi_error == 1) {
                /* remove the current alternate address from this host */
                H_LOCK;
                removeInterfaceAddr_r(host, interfaces[multi_i].addr, interfaces[multi_i].port);
                H_UNLOCK;
            }
        }
#ifdef AFS_DEMAND_ATTACH_FS
        /* try to bail ASAP if the fileserver is shutting down */
        FS_STATE_RDLOCK;
        if (fs_state.mode == FS_MODE_SHUTDOWN) {
            FS_STATE_UNLOCK;
            multi_Abort;
        }
        FS_STATE_UNLOCK;
#endif
    }
    multi_End_Ignore;
    H_LOCK;
    /* Destroy all connections except the one on which we succeeded */
    for (i = 0; i < j; i++)
        if (conns[i] != connSuccess)
            rx_DestroyConnection(conns[i]);

    free(interfaces);
    free(conns);

    if (connSuccess)
        return 0;               /* success */
    else
        return 1;               /* failure */
}

#endif /* !defined(INTERPRET_DUMP) */