windows-remove-give-up-callbacks-scache-recycling-20070627

[openafs.git] / src / WINNT / afsd / cm_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
 */

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

#include <windows.h>
#include <winsock2.h>
#include <malloc.h>
#include <string.h>
#include <stdlib.h>

#include "afsd.h"
#include <osi.h>
#include <rx_pthread.h>

#include <WINNT/syscfg.h>
#include <WINNT/afsreg.h>
#include <../afsrdr/kif.h>

/*extern void afsi_log(char *pattern, ...);*/

/* read/write lock for all global storage in this module */
osi_rwlock_t cm_callbackLock;

#ifdef AFS_FREELANCE_CLIENT
extern osi_mutex_t cm_Freelance_Lock;
#endif

/* count of # of callback breaking messages received by this CM so far.  We use
 * this count in determining whether there have been any callback breaks that
 * apply to a call that returned a new callback.  If the counter doesn't
 * increase during a call, then we know that no callbacks were broken during
 * that call, and thus that the callback that was just returned is still valid.
 */
long cm_callbackCount;

/* count of number of RPCs potentially returning a callback executing now.
 * When this counter hits zero, we can clear out the racing revokes list, since
 * at that time, we know that none of the just-executed callback revokes will
 * apply to any future call that returns a callback (since the latter hasn't
 * even started execution yet).
 */
long cm_activeCallbackGrantingCalls;

/* list of callbacks that have been broken recently.  If a call returning a
 * callback is executing and a callback revoke runs immediately after it at the
 * server, the revoke may end up being processed before the response to the
 * original callback granting call.  We detect this by keeping a list of
 * callback revokes that have been received since we *started* the callback
 * granting call, and discarding any callbacks received for the same file ID,
 * even if the callback revoke was received before the callback grant.
 */
cm_racingRevokes_t *cm_racingRevokesp;

/* record a (potentially) racing revoke for this file ID; null means for all
 * file IDs, and is used by InitCallBackState.
 *
 * The cancelFlags describe whether we're just discarding callbacks for the same
 * file ID, the same volume, or all from the same server.
 *
 * Called with no locks held.
 */
void cm_RecordRacingRevoke(cm_fid_t *fidp, long cancelFlags)
{
    cm_racingRevokes_t *rp;

    lock_ObtainWrite(&cm_callbackLock);

    osi_Log3(afsd_logp, "RecordRacingRevoke Volume %d Flags %lX activeCalls %d",
                fidp ? fidp->volume : 0, cancelFlags, cm_activeCallbackGrantingCalls);

    if (cm_activeCallbackGrantingCalls > 0) {
        rp = malloc(sizeof(*rp));
        memset(rp, 0, sizeof(*rp));
        osi_QAdd((osi_queue_t **) &cm_racingRevokesp, &rp->q);
        rp->flags |= (cancelFlags & CM_RACINGFLAG_ALL);
        if (fidp) rp->fid = *fidp;
        rp->callbackCount = ++cm_callbackCount;
    }
    lock_ReleaseWrite(&cm_callbackLock);
}

/*
 * When we lose a callback, may have to send change notification replies.
 * Do not call with a lock on the scp.
 */
void cm_CallbackNotifyChange(cm_scache_t *scp)
{
    DWORD dwDelay = 0;
    HKEY  hKey;
    DWORD dummyLen;

    /* why does this have to query the registry each time? */
        if (RegOpenKeyEx( HKEY_LOCAL_MACHINE, 
                      AFSREG_CLT_OPENAFS_SUBKEY,
                      0,
                      KEY_READ|KEY_QUERY_VALUE,
                      &hKey) == ERROR_SUCCESS) {

        dummyLen = sizeof(DWORD);
        RegQueryValueEx(hKey, "CallBack Notify Change Delay", NULL, NULL,
                        (BYTE *) &dwDelay, &dummyLen);
        RegCloseKey(hKey);
    }

    if (dwDelay > 5000)    /* do not allow a delay of more then 5 seconds */
        dwDelay = 5000;   

    osi_Log3(afsd_logp, "CallbackNotifyChange FileType %d Flags %lX Delay %dms",
              scp->fileType, scp->flags, dwDelay);

    if (dwDelay)
        Sleep(dwDelay);

    /* for directories, this sends a change notification on the dir itself */
    if (scp->fileType == CM_SCACHETYPE_DIRECTORY) {
#ifndef AFSIFS
        if (scp->flags & CM_SCACHEFLAG_ANYWATCH)
            smb_NotifyChange(0,
                             FILE_NOTIFY_GENERIC_DIRECTORY_FILTER,
                             scp, NULL, NULL, TRUE);
#else
        dc_break_callback(FID_HASH_FN(&scp->fid));
#endif
    } else {
        /* and for files, this sends a change notification on the file's parent dir */
        cm_fid_t tfid;
        cm_scache_t *dscp;

        tfid.cell = scp->fid.cell;
        tfid.volume = scp->fid.volume;
        tfid.vnode = scp->parentVnode;
        tfid.unique = scp->parentUnique;
        dscp = cm_FindSCache(&tfid);
#ifndef AFSIFS
        if ( dscp &&
             dscp->flags & CM_SCACHEFLAG_ANYWATCH )
            smb_NotifyChange( 0,
                              FILE_NOTIFY_GENERIC_FILE_FILTER,
                              dscp, NULL, NULL, TRUE);
#else
        if (dscp)
            dc_break_callback(FID_HASH_FN(&dscp->fid));
#endif
        if (dscp) 
            cm_ReleaseSCache(dscp);
    }
}

/* called with no locks held for every file ID that is revoked directly by
 * a callback revoke call.  Does not have to handle volume callback breaks,
 * since those have already been split out.
 *
 * The callp parameter is currently unused.
 */
void cm_RevokeCallback(struct rx_call *callp, cm_cell_t * cellp, AFSFid *fidp)
{
    cm_fid_t tfid;
    cm_scache_t *scp;
    long hash;
        
    /* don't bother setting cell, since we won't be checking it (to aid
     * in working with multi-homed servers: we don't know the cell if we
     * don't recognize the IP address).
     */
    tfid.cell = 0;
    tfid.volume = fidp->Volume;
    tfid.vnode = fidp->Vnode;
    tfid.unique = fidp->Unique;
    hash = CM_SCACHE_HASH(&tfid);

    osi_Log3(afsd_logp, "RevokeCallback vol %u vn %u uniq %u",
             fidp->Volume, fidp->Vnode, fidp->Unique);
        
    /* do this first, so that if we're executing a callback granting call
     * at this moment, we kill it before it can be merged in.  Otherwise,
     * it could complete while we're doing the scan below, and get missed
     * by both the scan and by this code.
     */
    cm_RecordRacingRevoke(&tfid, 0);

    lock_ObtainWrite(&cm_scacheLock);
    /* do all in the hash bucket, since we don't know how many we'll find with
     * varying cells.
     */
    for (scp = cm_data.scacheHashTablep[hash]; scp; scp=scp->nextp) {
        if (scp->fid.volume == tfid.volume &&
             scp->fid.vnode == tfid.vnode &&
             scp->fid.unique == tfid.unique &&
             (cellp == NULL || scp->fid.cell == cellp->cellID) &&
             scp->cbExpires > 0 && 
             scp->cbServerp != NULL)
        {
            cm_HoldSCacheNoLock(scp);
            lock_ReleaseWrite(&cm_scacheLock);
            osi_Log4(afsd_logp, "RevokeCallback Discarding SCache scp 0x%p vol %u vn %u uniq %u", 
                     scp, scp->fid.volume, scp->fid.vnode, scp->fid.unique);

            lock_ObtainMutex(&scp->mx);
            cm_DiscardSCache(scp);
            lock_ReleaseMutex(&scp->mx);

            cm_CallbackNotifyChange(scp);
            
            lock_ObtainWrite(&cm_scacheLock);
            cm_ReleaseSCacheNoLock(scp);
        }
    }
    lock_ReleaseWrite(&cm_scacheLock);

    osi_Log3(afsd_logp, "RevokeCallback Complete vol %u vn %u uniq %u",
             fidp->Volume, fidp->Vnode, fidp->Unique);
}

/* called to revoke a volume callback, which is typically issued when a volume
 * is moved from one server to another.
 *
 * Called with no locks held.
 */
void cm_RevokeVolumeCallback(struct rx_call *callp, cm_cell_t *cellp, AFSFid *fidp)
{
    long hash;
    cm_scache_t *scp;
    cm_fid_t tfid;

    osi_Log1(afsd_logp, "RevokeVolumeCallback vol %d", fidp->Volume);

    /* do this first, so that if we're executing a callback granting call
     * at this moment, we kill it before it can be merged in.  Otherwise,
     * it could complete while we're doing the scan below, and get missed
     * by both the scan and by this code.
     */
    tfid.cell = tfid.vnode = tfid.unique = 0;
    tfid.volume = fidp->Volume;
    cm_RecordRacingRevoke(&tfid, CM_RACINGFLAG_CANCELVOL);

    lock_ObtainWrite(&cm_scacheLock);
    for (hash = 0; hash < cm_data.scacheHashTableSize; hash++) {
        for(scp=cm_data.scacheHashTablep[hash]; scp; scp=scp->nextp) {
            if (scp->fid.volume == fidp->Volume &&
                (cellp == NULL || scp->fid.cell == cellp->cellID) &&
                 scp->cbExpires > 0 &&
                 scp->cbServerp != NULL) {
                cm_HoldSCacheNoLock(scp);
                lock_ReleaseWrite(&cm_scacheLock);

                lock_ObtainMutex(&scp->mx);
                osi_Log4(afsd_logp, "RevokeVolumeCallback Discarding SCache scp 0x%p vol %u vn %u uniq %u", 
                          scp, scp->fid.volume, scp->fid.vnode, scp->fid.unique);
                cm_DiscardSCache(scp);
                lock_ReleaseMutex(&scp->mx);

                cm_CallbackNotifyChange(scp);
                lock_ObtainWrite(&cm_scacheLock);
                cm_ReleaseSCacheNoLock(scp);
            }
        }       /* search one hash bucket */
    }   /* search all hash buckets */

    lock_ReleaseWrite(&cm_scacheLock);

    osi_Log1(afsd_logp, "RevokeVolumeCallback Complete vol %d", fidp->Volume);
}

/*
 * afs_data_pointer_to_int32() - returns least significant afs_int32 of the
 * given data pointer, without triggering "cast truncates pointer"
 * warnings.  We use this where we explicitly don't care whether a
 * pointer is truncated -- it loses information where a pointer is
 * larger than an afs_int32.
 */

static afs_int32
afs_data_pointer_to_int32(const void *p)
{
    union {
        afs_int32 i32[sizeof(void *) / sizeof(afs_int32)];
        const void *p;
    } ip;

    int i32_sub;                /* subscript of least significant afs_int32 in ip.i32[] */

    /* set i32_sub */

    {
        /* used to determine the byte order of the system */

        union {
            char c[sizeof(int) / sizeof(char)];
            int i;
        } ci;

        ci.i = 1;
        if (ci.c[0] == 1) {
            /* little-endian system */
            i32_sub = 0;
        } else {
            /* big-endian system */
            i32_sub = (sizeof ip.i32 / sizeof ip.i32[0]) - 1;
        }
    }

    ip.p = p;
    return ip.i32[i32_sub];
}
/*------------------------------------------------------------------------
 * EXPORTED SRXAFSCB_CallBack
 *
 * Description:
 *      Routine called by the server-side callback RPC interface to
 *      implement passing in callback information.
 *      table.
 *
 * Arguments:
 *      rx_call    : Ptr to Rx call on which this request came in.
 *      fidsArrayp : Ptr to array of fids involved.
 *      cbsArrayp  : Ptr to matching callback info for the fids.
 *
 * Returns:
 *      0 (always).
 *
 * Environment:
 *      Nothing interesting.
 *
 * Side Effects:
 *      As advertised.
 *------------------------------------------------------------------------*/
/* handle incoming RPC callback breaking message.
 * Called with no locks held.
 */
int
SRXAFSCB_CallBack(struct rx_call *callp, AFSCBFids *fidsArrayp, AFSCBs *cbsArrayp)
{
    int i;
    AFSFid *tfidp;
    struct rx_connection *connp;
    struct rx_peer *peerp;
    unsigned long host = 0;
    unsigned short port = 0;
    cm_server_t *tsp = NULL;
    cm_cell_t * cellp = NULL;

    MUTEX_ENTER(&callp->lock);

    if ((connp = rx_ConnectionOf(callp)) && (peerp = rx_PeerOf(connp))) {
        host = rx_HostOf(peerp);
        port = rx_PortOf(peerp);

        tsp = cm_FindServerByIP(host, CM_SERVER_FILE);
        if (tsp)
            cellp = tsp->cellp;
    }

    osi_Log2(afsd_logp, "SRXAFSCB_CallBack from host 0x%x port %d",
              ntohl(host),
              ntohs(port));

    for (i=0; i < (long) fidsArrayp->AFSCBFids_len; i++) {
        tfidp = &fidsArrayp->AFSCBFids_val[i];
                
        if (tfidp->Volume == 0)
            continue;   /* means don't do anything */
        else if (tfidp->Vnode == 0)
            cm_RevokeVolumeCallback(callp, cellp, tfidp);
        else
            cm_RevokeCallback(callp, cellp, tfidp);
    }

    MUTEX_EXIT(&callp->lock);
    return 0;
}

/*------------------------------------------------------------------------
 * EXPORTED SRXAFSCB_InitCallBackState
 *
 * Description:
 *      Routine called by the server-side callback RPC interface to
 *      implement clearing all callbacks from this host.
 *
 * Arguments:
 *      rx_call : Ptr to Rx call on which this request came in.
 *
 * Returns:
 *      0 (always).
 *
 * Environment:
 *      Nothing interesting.
 *
 * Side Effects:
 *      As advertised.
 *------------------------------------------------------------------------*/
/* called with no locks by RPC system when a server indicates that it has never
 * heard from us, or for other reasons has had to discard callbacks from us
 * without telling us, e.g. a network partition.
 */
int
SRXAFSCB_InitCallBackState(struct rx_call *callp)
{
    struct sockaddr_in taddr;
    cm_server_t *tsp;
    cm_scache_t *scp;
    int hash;
    int discarded;
    struct rx_connection *connp;
    struct rx_peer *peerp;
    unsigned long host = 0;
    unsigned short port = 0;

    MUTEX_ENTER(&callp->lock);

    if ((connp = rx_ConnectionOf(callp)) && (peerp = rx_PeerOf(connp))) {
        host = rx_HostOf(peerp);
        port = rx_PortOf(peerp);
    }

    osi_Log2(afsd_logp, "SRXAFSCB_InitCallBackState from host 0x%x port %d",
              ntohl(host),
              ntohs(port));

    if ((rx_ConnectionOf(callp)) && (rx_PeerOf(rx_ConnectionOf(callp)))) {
        taddr.sin_family = AF_INET;
        taddr.sin_addr.s_addr = rx_HostOf(rx_PeerOf(rx_ConnectionOf(callp)));

        tsp = cm_FindServer(&taddr, CM_SERVER_FILE);

        osi_Log1(afsd_logp, "Init Callback State server %x", tsp);
        
        /* record the callback in the racing revokes structure.  This
         * shouldn't be necessary, since we shouldn't be making callback
         * granting calls while we're going to get an initstate call,
         * but there probably are some obscure races, so better safe
         * than sorry.
         *
         * We do this first since we don't hold the cm_scacheLock and vnode
         * locks over the entire callback scan operation below.  The
         * big loop below is guaranteed to hit any callback already
         * processed.  The call to RecordRacingRevoke is guaranteed
         * to kill any callback that is currently being returned.
         * Anything that sneaks past both must start
         * after the call to RecordRacingRevoke.
         */
        cm_RecordRacingRevoke(NULL, CM_RACINGFLAG_CANCELALL);
        
        /* now search all vnodes looking for guys with this callback, if we
         * found it, or guys with any callbacks, if we didn't find the server
         * (that's how multihomed machines will appear and how we'll handle
         * them, albeit a little inefficiently).  That is, we're discarding all
         * callbacks from all hosts if we get an initstate call from an unknown
         * host.  Since these calls are rare, and multihomed servers
         * are "rare," hopefully this won't be a problem.
         */
        lock_ObtainWrite(&cm_scacheLock);
        for (hash = 0; hash < cm_data.scacheHashTableSize; hash++) {
            for (scp=cm_data.scacheHashTablep[hash]; scp; scp=scp->nextp) {
                cm_HoldSCacheNoLock(scp);
                lock_ReleaseWrite(&cm_scacheLock);
                lock_ObtainMutex(&scp->mx);
                discarded = 0;
                if (scp->cbExpires > 0 && scp->cbServerp != NULL) {
                    /* we have a callback, now decide if we should clear it */
                    if (scp->cbServerp == tsp || tsp == NULL) {
                        osi_Log4(afsd_logp, "InitCallbackState Discarding SCache scp 0x%p vol %u vn %u uniq %u", 
                                  scp, scp->fid.volume, scp->fid.vnode, scp->fid.unique);
                        cm_DiscardSCache(scp);
                        discarded = 1;
                    }
                }
                lock_ReleaseMutex(&scp->mx);
                if (discarded)
                    cm_CallbackNotifyChange(scp);
                lock_ObtainWrite(&cm_scacheLock);
                cm_ReleaseSCacheNoLock(scp);
            }   /* search one hash bucket */
        }       /* search all hash buckets */
        
        lock_ReleaseWrite(&cm_scacheLock);
        
        if (tsp) {
            /* reset the No flags on the server */
            cm_SetServerNo64Bit(tsp, 0);
            cm_SetServerNoInlineBulk(tsp, 0);

            /* we're done with the server structure */
            cm_PutServer(tsp);
        } 
    }
    MUTEX_EXIT(&callp->lock);
    return 0;
}

/*------------------------------------------------------------------------
 * EXPORTED SRXAFSCB_Probe
 *
 * Description:
 *      Routine called by the server-side callback RPC interface to
 *      implement ``probing'' the Cache Manager, just making sure it's
 *      still there.
 *
 * Arguments:
 *      rx_call : Ptr to Rx call on which this request came in.
 *
 * Returns:
 *      0 (always).
 *
 * Environment:
 *      Nothing interesting.
 *
 * Side Effects:
 *      As advertised.
 *------------------------------------------------------------------------*/
int
SRXAFSCB_Probe(struct rx_call *callp)
{
    struct rx_connection *connp;
    struct rx_peer *peerp;
    unsigned long host = 0;
    unsigned short port = 0;

    MUTEX_ENTER(&callp->lock);

    if ((connp = rx_ConnectionOf(callp)) && (peerp = rx_PeerOf(connp))) {
        host = rx_HostOf(peerp);
        port = rx_PortOf(peerp);
    }

    osi_Log2(afsd_logp, "SRXAFSCB_Probe from host 0x%x port %d",
              ntohl(host),
              ntohs(port));

    MUTEX_EXIT(&callp->lock);
    return 0;
}

/*------------------------------------------------------------------------
 * EXPORTED SRXAFSCB_GetLock
 *
 * Description:
 *      Routine called by the server-side callback RPC interface to
 *      implement pulling out the contents of a lock in the lock
 *      table.
 *
 * Arguments:
 *      a_call   : Ptr to Rx call on which this request came in.
 *      a_index  : Index of desired lock.
 *      a_result : Ptr to a buffer for the given lock.
 *
 * Returns:
 *      0 if everything went fine,
 *      1 if we were given a bad index.
 *
 * Environment:
 *      Nothing interesting.
 *
 * Side Effects:
 *      As advertised.
 *------------------------------------------------------------------------*/
/* debug interface */

extern osi_rwlock_t cm_aclLock;
extern osi_rwlock_t buf_globalLock;
extern osi_rwlock_t cm_callbackLock;
extern osi_rwlock_t cm_cellLock;
extern osi_rwlock_t cm_connLock;
extern osi_rwlock_t cm_daemonLock;
extern osi_rwlock_t cm_dnlcLock;
extern osi_rwlock_t cm_scacheLock;
extern osi_rwlock_t cm_serverLock;
extern osi_rwlock_t cm_userLock;
extern osi_rwlock_t cm_utilsLock;
extern osi_rwlock_t cm_volumeLock;
extern osi_rwlock_t smb_globalLock;
extern osi_rwlock_t smb_rctLock;

extern osi_mutex_t cm_Freelance_Lock;
extern osi_mutex_t cm_bufGetMutex;
extern osi_mutex_t cm_Afsdsbmt_Lock;
extern osi_mutex_t tokenEventLock;
extern osi_mutex_t  smb_ListenerLock;
extern osi_mutex_t smb_RawBufLock;
extern osi_mutex_t smb_Dir_Watch_Lock;

#define LOCKTYPE_RW     1
#define LOCKTYPE_MUTEX  2
static struct _ltable {
    char *name;
    char *addr;
    int  type;
} ltable[] = {
    {"cm_scacheLock",    (char*)&cm_scacheLock,         LOCKTYPE_RW},
    {"buf_globalLock",   (char*)&buf_globalLock,        LOCKTYPE_RW},
    {"cm_serverLock",    (char*)&cm_serverLock,         LOCKTYPE_RW},
    {"cm_callbackLock",  (char*)&cm_callbackLock,       LOCKTYPE_RW},
    {"cm_aclLock",       (char*)&cm_aclLock,            LOCKTYPE_RW},
    {"cm_cellLock",      (char*)&cm_cellLock,           LOCKTYPE_RW},
    {"cm_connLock",      (char*)&cm_connLock,           LOCKTYPE_RW},
    {"cm_userLock",      (char*)&cm_userLock,           LOCKTYPE_RW},
    {"cm_volumeLock",    (char*)&cm_volumeLock,         LOCKTYPE_RW},
    {"cm_daemonLock",    (char*)&cm_daemonLock,         LOCKTYPE_RW},
    {"cm_dnlcLock",      (char*)&cm_dnlcLock,           LOCKTYPE_RW},
    {"cm_utilsLock",     (char*)&cm_utilsLock,          LOCKTYPE_RW},
    {"smb_globalLock",   (char*)&smb_globalLock,        LOCKTYPE_RW},
    {"smb_rctLock",      (char*)&smb_rctLock,           LOCKTYPE_RW},
    {"cm_Freelance_Lock",(char*)&cm_Freelance_Lock,     LOCKTYPE_MUTEX},
    {"cm_bufGetMutex",   (char*)&cm_bufGetMutex,        LOCKTYPE_MUTEX},
    {"cm_Afsdsbmt_Lock", (char*)&cm_Afsdsbmt_Lock,      LOCKTYPE_MUTEX},
    {"tokenEventLock",   (char*)&tokenEventLock,        LOCKTYPE_MUTEX},
    {"smb_ListenerLock", (char*)&smb_ListenerLock,      LOCKTYPE_MUTEX},
    {"smb_RawBufLock",   (char*)&smb_RawBufLock,        LOCKTYPE_MUTEX},
    {"smb_Dir_Watch_Lock",(char*)&smb_Dir_Watch_Lock,   LOCKTYPE_MUTEX}
};

int
SRXAFSCB_GetLock(struct rx_call *callp, long index, AFSDBLock *lockp)
{
    struct _ltable *tl;          /*Ptr to lock table entry */
    osi_rwlock_t  *rwp;
    osi_mutex_t   *mtxp;
    int nentries;               /*Num entries in table */
    int code;                   /*Return code */
    struct rx_connection *connp;
    struct rx_peer *peerp;
    unsigned long host = 0;
    unsigned short port = 0;

    MUTEX_ENTER(&callp->lock);

    if ((connp = rx_ConnectionOf(callp)) && (peerp = rx_PeerOf(connp))) {
        host = rx_HostOf(peerp);
        port = rx_PortOf(peerp);
    }

    osi_Log3(afsd_logp, "SRXAFSCB_GetLock(%d) from host 0x%x port %d", 
             index, ntohl(host), ntohs(port));

    nentries = sizeof(ltable) / sizeof(struct _ltable);
    if (index < 0 || index >= nentries) {
        /*
         * Past EOF
         */
        code = 1;
    } else {
        /*
         * Found it - copy out its contents.
         */
        tl = &ltable[index];
        strncpy(lockp->name, tl->name, sizeof(lockp->name));
        lockp->name[sizeof(lockp->name)-1] = '\0';
        lockp->lock.waitStates = 0;
        switch ( tl->type ) {
        case LOCKTYPE_RW:
            rwp = (osi_rwlock_t *)tl->addr;
            lockp->lock.exclLocked = rwp->flags;
            lockp->lock.readersReading = rwp->readers;
            lockp->lock.numWaiting = rwp->waiters;
            break;
        case LOCKTYPE_MUTEX:
            mtxp = (osi_mutex_t *)tl->addr;
            lockp->lock.exclLocked = mtxp->flags;
            lockp->lock.readersReading = 0;
            lockp->lock.numWaiting = mtxp->waiters;
            break;
        }
        lockp->lock.pid_last_reader = 0;
        lockp->lock.pid_writer = 0;
        lockp->lock.src_indicator = 0;
        code = 0;
    }

    MUTEX_EXIT(&callp->lock);
    return code;
}

/* debug interface */
int
SRXAFSCB_GetCE(struct rx_call *callp, long index, AFSDBCacheEntry *cep)
{
    int i;
    cm_scache_t * scp;
    int code;
    struct rx_connection *connp;
    struct rx_peer *peerp;
    unsigned long host = 0;
    unsigned short port = 0;

    MUTEX_ENTER(&callp->lock);

    if ((connp = rx_ConnectionOf(callp)) && (peerp = rx_PeerOf(connp))) {
        host = rx_HostOf(peerp);
        port = rx_PortOf(peerp);
    }

    osi_Log2(afsd_logp, "SRXAFSCB_GetCE from host 0x%x port %d",
             ntohl(host), ntohs(port));

    lock_ObtainRead(&cm_scacheLock);
    for (i = 0; i < cm_data.scacheHashTableSize; i++) {
        for (scp = cm_data.scacheHashTablep[i]; scp; scp = scp->nextp) {
            if (index == 0)
                goto searchDone;
            index--;
        }                       /*Zip through current hash chain */
    }                           /*Zip through hash chains */

  searchDone:
    if (scp == NULL) {
        /*Past EOF */
        code = 1;
        goto fcnDone;
    }

    /*
     * Copy out the located entry.
     */
    memset(cep, 0, sizeof(AFSDBCacheEntry));
    cep->addr = afs_data_pointer_to_int32(scp);
    cep->cell = scp->fid.cell;
    cep->netFid.Volume = scp->fid.volume;
    cep->netFid.Vnode = scp->fid.vnode;
    cep->netFid.Unique = scp->fid.unique;
    cep->lock.waitStates = 0;
    cep->lock.exclLocked = scp->mx.flags;
    cep->lock.readersReading = 0;
    cep->lock.numWaiting = scp->mx.waiters;
    cep->lock.pid_last_reader = 0;
    cep->lock.pid_writer = 0;
    cep->lock.src_indicator = 0;
    cep->Length = scp->length.LowPart;
    cep->DataVersion = scp->dataVersion;
    cep->callback = afs_data_pointer_to_int32(scp->cbServerp);
    cep->cbExpires = scp->cbExpires;
    cep->refCount = scp->refCount;
    cep->opens = scp->openReads;
    cep->writers = scp->openWrites;
    switch (scp->fileType) {
    case CM_SCACHETYPE_FILE:
        cep->mvstat = 0;
        break;
    case CM_SCACHETYPE_MOUNTPOINT:
        cep->mvstat = 1;
        break;
    case CM_SCACHETYPE_DIRECTORY:
        if (scp->fid.vnode == 1 && scp->fid.unique == 1)
            cep->mvstat = 2;
        else
            cep->mvstat = 3;
        break;
    case CM_SCACHETYPE_SYMLINK:
        cep->mvstat = 4;
        break;
    case CM_SCACHETYPE_DFSLINK:
        cep->mvstat = 5;
        break;
    case CM_SCACHETYPE_INVALID:
        cep->mvstat = 6;
        break;
    }
    cep->states = 0;
    if (scp->flags & CM_SCACHEFLAG_STATD)
        cep->states |= 1;
    if (scp->flags & CM_SCACHEFLAG_RO || scp->flags & CM_SCACHEFLAG_PURERO)
        cep->states |= 4;
    if (scp->fileType == CM_SCACHETYPE_MOUNTPOINT &&
        scp->mountPointStringp[0])
        cep->states |= 8;
    if (scp->flags & CM_SCACHEFLAG_WAITING)
        cep->states |= 0x40;
    code = 0;

    /*
     * Return our results.
     */
  fcnDone:
    lock_ReleaseRead(&cm_scacheLock);

    MUTEX_EXIT(&callp->lock);
    return (code);
}

/* debug interface */
int
SRXAFSCB_GetCE64(struct rx_call *callp, long index, AFSDBCacheEntry64 *cep)
{
    int i;
    cm_scache_t * scp;
    int code;
    struct rx_connection *connp;
    struct rx_peer *peerp;
    unsigned long host = 0;
    unsigned short port = 0;

    MUTEX_ENTER(&callp->lock);

    if ((connp = rx_ConnectionOf(callp)) && (peerp = rx_PeerOf(connp))) {
        host = rx_HostOf(peerp);
        port = rx_PortOf(peerp);
    }

    osi_Log2(afsd_logp, "SRXAFSCB_GetCE64 from host 0x%x port %d",
             ntohl(host), ntohs(port));

    lock_ObtainRead(&cm_scacheLock);
    for (i = 0; i < cm_data.scacheHashTableSize; i++) {
        for (scp = cm_data.scacheHashTablep[i]; scp; scp = scp->nextp) {
            if (index == 0)
                goto searchDone;
            index--;
        }                       /*Zip through current hash chain */
    }                           /*Zip through hash chains */

  searchDone:
    if (scp == NULL) {
        /*Past EOF */
        code = 1;
        goto fcnDone;
    }

    /*
     * Copy out the located entry.
     */
    memset(cep, 0, sizeof(AFSDBCacheEntry64));
    cep->addr = afs_data_pointer_to_int32(scp);
    cep->cell = scp->fid.cell;
    cep->netFid.Volume = scp->fid.volume;
    cep->netFid.Vnode = scp->fid.vnode;
    cep->netFid.Unique = scp->fid.unique;
    cep->lock.waitStates = 0;
    cep->lock.exclLocked = scp->mx.flags;
    cep->lock.readersReading = 0;
    cep->lock.numWaiting = scp->mx.waiters;
    cep->lock.pid_last_reader = 0;
    cep->lock.pid_writer = 0;
    cep->lock.src_indicator = 0;
#if !defined(AFS_64BIT_ENV)
    cep->Length.high = scp->length.HighPart;
    cep->Length.low = scp->length.LowPart;
#else
    cep->Length = (afs_int64) scp->length.QuadPart;
#endif
    cep->DataVersion = scp->dataVersion;
    cep->callback = afs_data_pointer_to_int32(scp->cbServerp);
    cep->cbExpires = scp->cbExpires;
    cep->refCount = scp->refCount;
    cep->opens = scp->openReads;
    cep->writers = scp->openWrites;
    switch (scp->fileType) {
    case CM_SCACHETYPE_FILE:
        cep->mvstat = 0;
        break;
    case CM_SCACHETYPE_MOUNTPOINT:
        cep->mvstat = 1;
        break;
    case CM_SCACHETYPE_DIRECTORY:
        if (scp->fid.vnode == 1 && scp->fid.unique == 1)
            cep->mvstat = 2;
        else
            cep->mvstat = 3;
        break;
    case CM_SCACHETYPE_SYMLINK:
        cep->mvstat = 4;
        break;
    case CM_SCACHETYPE_DFSLINK:
        cep->mvstat = 5;
        break;
    case CM_SCACHETYPE_INVALID:
        cep->mvstat = 6;
        break;
    }
    cep->states = 0;
    if (scp->flags & CM_SCACHEFLAG_STATD)
        cep->states |= 1;
    if (scp->flags & CM_SCACHEFLAG_RO || scp->flags & CM_SCACHEFLAG_PURERO)
        cep->states |= 4;
    if (scp->fileType == CM_SCACHETYPE_MOUNTPOINT &&
        scp->mountPointStringp[0])
        cep->states |= 8;
    if (scp->flags & CM_SCACHEFLAG_WAITING)
        cep->states |= 0x40;
    code = 0;

    /*
     * Return our results.
     */
  fcnDone:
    lock_ReleaseRead(&cm_scacheLock);

    MUTEX_EXIT(&callp->lock);
    return (code);
}

/* debug interface: not implemented */
int
SRXAFSCB_XStatsVersion(struct rx_call *callp, long *vp)
{
    struct rx_connection *connp;
    struct rx_peer *peerp;
    unsigned long host = 0;
    unsigned short port = 0;

    MUTEX_ENTER(&callp->lock);

    if ((connp = rx_ConnectionOf(callp)) && (peerp = rx_PeerOf(connp))) {
        host = rx_HostOf(peerp);
        port = rx_PortOf(peerp);
    }

    osi_Log2(afsd_logp, "SRXAFSCB_XStatsVersion from host 0x%x port %d - not implemented",
             ntohl(host), ntohs(port));
    *vp = -1;

    MUTEX_EXIT(&callp->lock);
    return RXGEN_OPCODE;
}

/* debug interface: not implemented */
int
SRXAFSCB_GetXStats(struct rx_call *callp, long cvn, long coln, long *srvp, long *timep,
                   AFSCB_CollData *datap)
{
    struct rx_connection *connp;
    struct rx_peer *peerp;
    unsigned long host = 0;
    unsigned short port = 0;

    MUTEX_ENTER(&callp->lock);

    if ((connp = rx_ConnectionOf(callp)) && (peerp = rx_PeerOf(connp))) {
        host = rx_HostOf(peerp);
        port = rx_PortOf(peerp);
    }

    osi_Log2(afsd_logp, "SRXAFSCB_GetXStats from host 0x%x port %d - not implemented",
             ntohl(host), ntohs(port));

    MUTEX_EXIT(&callp->lock);
    return RXGEN_OPCODE;
}

int
SRXAFSCB_InitCallBackState2(struct rx_call *callp, struct interfaceAddr* addr)
{
    osi_Log0(afsd_logp, "SRXAFSCB_InitCallBackState2 ->");

    return SRXAFSCB_InitCallBackState(callp);
}

/* debug interface */
int
SRXAFSCB_WhoAreYou(struct rx_call *callp, struct interfaceAddr* addr)
{
    int i;
    int cm_noIPAddr;         /* number of client network interfaces */
    int cm_IPAddr[CM_MAXINTERFACE_ADDR];    /* client's IP address in host order */
    int cm_SubnetMask[CM_MAXINTERFACE_ADDR];/* client's subnet mask in host order*/
    int cm_NetMtu[CM_MAXINTERFACE_ADDR];    /* client's MTU sizes */
    int cm_NetFlags[CM_MAXINTERFACE_ADDR];  /* network flags */
    long code;
    struct rx_connection *connp;
    struct rx_peer *peerp;
    unsigned long host = 0;
    unsigned short port = 0;

    MUTEX_ENTER(&callp->lock);

    if ((connp = rx_ConnectionOf(callp)) && (peerp = rx_PeerOf(connp))) {
        host = rx_HostOf(peerp);
        port = rx_PortOf(peerp);
    }

    /* get network related info */
    cm_noIPAddr = CM_MAXINTERFACE_ADDR;
    code = syscfg_GetIFInfo(&cm_noIPAddr,
                             cm_IPAddr, cm_SubnetMask,
                             cm_NetMtu, cm_NetFlags);

    /* return all network interface addresses */
    osi_Log2(afsd_logp, "SRXAFSCB_WhoAreYou from host 0x%x port %d",
              ntohl(host),
              ntohs(port));

    addr->numberOfInterfaces = cm_noIPAddr;
    addr->uuid = cm_data.Uuid;
    for ( i=0; i < cm_noIPAddr; i++ ) {
        addr->addr_in[i] = cm_IPAddr[i];
        addr->subnetmask[i] = cm_SubnetMask[i];
        addr->mtu[i] = (rx_mtu == -1 || (rx_mtu != -1 && cm_NetMtu[i] < rx_mtu)) ? 
            cm_NetMtu[i] : rx_mtu;
    }

    MUTEX_EXIT(&callp->lock);
    return 0;
}

int
SRXAFSCB_InitCallBackState3(struct rx_call *callp, afsUUID* serverUuid)
{
    char *p = NULL;

    if (UuidToString((UUID *)serverUuid, &p) == RPC_S_OK) {
        osi_Log1(afsd_logp, "SRXAFSCB_InitCallBackState3 %s ->",p);
        RpcStringFree(&p);
    } else
        osi_Log0(afsd_logp, "SRXAFSCB_InitCallBackState3 - no server Uuid ->");

    return SRXAFSCB_InitCallBackState(callp);
}

/* debug interface */
int
SRXAFSCB_ProbeUuid(struct rx_call *callp, afsUUID* clientUuid)
{
    struct rx_connection *connp;
    struct rx_peer *peerp;
    unsigned long host = 0;
    unsigned short port = 0;
    char *p,*q;
    int code = 0;

    MUTEX_ENTER(&callp->lock);

    if ((connp = rx_ConnectionOf(callp)) && (peerp = rx_PeerOf(connp))) {
        host = rx_HostOf(peerp);
        port = rx_PortOf(peerp);
    }

    if ( !afs_uuid_equal(&cm_data.Uuid, clientUuid) ) {
        UuidToString((UUID *)&cm_data.Uuid, &p);
        UuidToString((UUID *)clientUuid, &q);
        osi_Log4(afsd_logp, "SRXAFSCB_ProbeUuid %s != %s from host 0x%x port %d", 
                  osi_LogSaveString(afsd_logp,p), 
                  osi_LogSaveString(afsd_logp,q),
                  ntohl(host),
                  ntohs(port));
        RpcStringFree(&p);
        RpcStringFree(&q);

        code = 1;       /* failure */
    } else
        osi_Log2(afsd_logp, "SRXAFSCB_ProbeUuid (success) from host 0x%x port %d",
                  ntohl(host),
                  ntohs(port));

    MUTEX_EXIT(&callp->lock);
    return code;
}

/* debug interface */
int 
SRXAFSCB_GetCellByNum(struct rx_call *callp, afs_int32 a_cellnum,
                      char **a_name, serverList *a_hosts)
{
    afs_int32 sn;
    cm_cell_t * cellp;
    cm_serverRef_t * serverRefp; 
    struct rx_connection *connp;
    struct rx_peer *peerp;
    unsigned long host = 0;
    unsigned short port = 0;

    MUTEX_ENTER(&callp->lock);

    if ((connp = rx_ConnectionOf(callp)) && (peerp = rx_PeerOf(connp))) {
        host = rx_HostOf(peerp);
        port = rx_PortOf(peerp);
    }

    osi_Log3(afsd_logp, "SRXAFSCB_GetCellByNum(%d) from host 0x%x port %d",
             a_cellnum, ntohl(host), ntohs(port));

    a_hosts->serverList_val = 0;
    a_hosts->serverList_len = 0;

    cellp = cm_FindCellByID(a_cellnum);
    if (!cellp) {
        *a_name = strdup("");
        MUTEX_EXIT(&callp->lock);
        return 0;
    }

    lock_ObtainRead(&cm_serverLock);
    *a_name = strdup(cellp->name);

    for ( sn = 0, serverRefp = cellp->vlServersp; 
          sn < AFSMAXCELLHOSTS && serverRefp;
          sn++, serverRefp = serverRefp->next);

    a_hosts->serverList_len = sn;
    a_hosts->serverList_val = (afs_int32 *)osi_Alloc(sn * sizeof(afs_int32));

    for ( sn = 0, serverRefp = cellp->vlServersp; 
          sn < AFSMAXCELLHOSTS && serverRefp;
          sn++, serverRefp = serverRefp->next)
    {
        a_hosts->serverList_val[sn] = ntohl(serverRefp->server->addr.sin_addr.s_addr);
    }

    lock_ReleaseRead(&cm_serverLock);
    MUTEX_EXIT(&callp->lock);
    return 0;
}

/* debug interface */
int 
SRXAFSCB_TellMeAboutYourself( struct rx_call *callp, 
                              struct interfaceAddr *addr,
                              Capabilities * capabilities)
{
    int i;
    afs_int32 *dataBuffP;
    afs_int32 dataBytes;
    int cm_noIPAddr;         /* number of client network interfaces */
    int cm_IPAddr[CM_MAXINTERFACE_ADDR];    /* client's IP address in host order */
    int cm_SubnetMask[CM_MAXINTERFACE_ADDR];/* client's subnet mask in host order*/
    int cm_NetMtu[CM_MAXINTERFACE_ADDR];    /* client's MTU sizes */
    int cm_NetFlags[CM_MAXINTERFACE_ADDR];  /* network flags */
    long code;
    struct rx_connection *connp;
    struct rx_peer *peerp;
    unsigned long host = 0;
    unsigned short port = 0;

    MUTEX_ENTER(&callp->lock);

    if ((connp = rx_ConnectionOf(callp)) && (peerp = rx_PeerOf(connp))) {
        host = rx_HostOf(peerp);
        port = rx_PortOf(peerp);
    }

    /* get network related info */
    cm_noIPAddr = CM_MAXINTERFACE_ADDR;
    code = syscfg_GetIFInfo(&cm_noIPAddr,
                             cm_IPAddr, cm_SubnetMask,
                             cm_NetMtu, cm_NetFlags);

    osi_Log2(afsd_logp, "SRXAFSCB_TellMeAboutYourself from host 0x%x port %d",
              ntohl(host),
              ntohs(port));

    /* return all network interface addresses */
    addr->numberOfInterfaces = cm_noIPAddr;
    addr->uuid = cm_data.Uuid;
    for ( i=0; i < cm_noIPAddr; i++ ) {
        addr->addr_in[i] = cm_IPAddr[i];
        addr->subnetmask[i] = cm_SubnetMask[i];
        addr->mtu[i] = (rx_mtu == -1 || (rx_mtu != -1 && cm_NetMtu[i] < rx_mtu)) ? 
            cm_NetMtu[i] : rx_mtu;
    }

    dataBytes = 1 * sizeof(afs_int32);
    dataBuffP = (afs_int32 *) osi_Alloc(dataBytes);
    dataBuffP[0] = CLIENT_CAPABILITY_ERRORTRANS;
    capabilities->Capabilities_len = dataBytes / sizeof(afs_int32);
    capabilities->Capabilities_val = dataBuffP;

    MUTEX_EXIT(&callp->lock);
    return 0;
}

/*------------------------------------------------------------------------
 * EXPORTED SRXAFSCB_GetServerPrefs
 *
 * Description:
 *      Routine to list server preferences used by this client.
 *
 * Arguments:
 *      a_call  : Ptr to Rx call on which this request came in.
 *      a_index : Input server index
 *      a_srvr_addr  : Output server address (0xffffffff on last server)
 *      a_srvr_rank  : Output server rank
 *
 * Returns:
 *      0 on success
 *
 * Environment:
 *      Nothing interesting.
 *
 * Side Effects:
 *      As advertised.
 *------------------------------------------------------------------------*/

int SRXAFSCB_GetServerPrefs(
    struct rx_call *callp,
    afs_int32 a_index,
    afs_int32 *a_srvr_addr,
    afs_int32 *a_srvr_rank)
{
    struct rx_connection *connp;
    struct rx_peer *peerp;
    unsigned long host = 0;
    unsigned short port = 0;

    MUTEX_ENTER(&callp->lock);

    if ((connp = rx_ConnectionOf(callp)) && (peerp = rx_PeerOf(connp))) {
        host = rx_HostOf(peerp);
        port = rx_PortOf(peerp);
    }

    osi_Log2(afsd_logp, "SRXAFSCB_GetServerPrefs from host 0x%x port %d - not implemented",
              ntohl(host),
              ntohs(port));

    *a_srvr_addr = 0xffffffff;
    *a_srvr_rank = 0xffffffff;

    MUTEX_EXIT(&callp->lock);
    return 0;
}

/*------------------------------------------------------------------------
 * EXPORTED SRXAFSCB_GetCellServDB
 *
 * Description:
 *      Routine to list cells configured for this client
 *
 * Arguments:
 *      a_call  : Ptr to Rx call on which this request came in.
 *      a_index : Input cell index
 *      a_name  : Output cell name ("" on last cell)
 *      a_hosts : Output cell database servers
 *
 * Returns:
 *      0 on success
 *
 * Environment:
 *      Nothing interesting.
 *
 * Side Effects:
 *      As advertised.
 *------------------------------------------------------------------------*/

int SRXAFSCB_GetCellServDB(struct rx_call *callp, afs_int32 index, char **a_name, 
                           serverList *a_hosts)
{
    char *t_name;
    struct rx_connection *connp;
    struct rx_peer *peerp;
    unsigned long host = 0;
    unsigned short port = 0;

    MUTEX_ENTER(&callp->lock);

    if ((connp = rx_ConnectionOf(callp)) && (peerp = rx_PeerOf(connp))) {
        host = rx_HostOf(peerp);
        port = rx_PortOf(peerp);
    }

    osi_Log2(afsd_logp, "SRXAFSCB_GetCellServDB from host 0x%x port %d - not implemented",
             ntohl(host), ntohs(port));

    t_name = (char *)malloc(AFSNAMEMAX);
    t_name[0] = '\0';
    *a_name = t_name;
    a_hosts->serverList_len = 0;

    MUTEX_EXIT(&callp->lock);
    return 0;
}

/*------------------------------------------------------------------------
 * EXPORTED SRXAFSCB_GetLocalCell
 *
 * Description:
 *      Routine to return name of client's local cell
 *
 * Arguments:
 *      a_call  : Ptr to Rx call on which this request came in.
 *      a_name  : Output cell name
 *
 * Returns:
 *      0 on success
 *
 * Environment:
 *      Nothing interesting.
 *
 * Side Effects:
 *      As advertised.
 *------------------------------------------------------------------------*/

int SRXAFSCB_GetLocalCell(struct rx_call *callp, char **a_name)
{
    char *t_name;
    struct rx_connection *connp;
    struct rx_peer *peerp;
    unsigned long host = 0;
    unsigned short port = 0;

    MUTEX_ENTER(&callp->lock);

    if ((connp = rx_ConnectionOf(callp)) && (peerp = rx_PeerOf(connp))) {
        host = rx_HostOf(peerp);
        port = rx_PortOf(peerp);
    }

    osi_Log2(afsd_logp, "SRXAFSCB_GetLocalCell from host 0x%x port %d",
             ntohl(host), ntohs(port));

    if (cm_data.rootCellp) {
        t_name = (char *)malloc(strlen(cm_data.rootCellp->name)+1);
        strcpy(t_name, cm_data.rootCellp->name);
    } else {
        t_name = (char *)malloc(1);
        t_name[0] = '\0';
    }
    *a_name = t_name;

    MUTEX_EXIT(&callp->lock);
    return 0;
}


/*
 * afs_MarshallCacheConfig - marshall client cache configuration
 *
 * PARAMETERS
 *
 * IN callerVersion - the rpc stat version of the caller.
 *
 * IN config - client cache configuration.
 *
 * OUT ptr - buffer where configuration is marshalled.
 *
 * RETURN CODES
 *
 * Returns void.
 */
static void afs_MarshallCacheConfig(
    afs_uint32 callerVersion,
    cm_initparams_v1 *config,
    afs_uint32 *ptr)
{
    /*
     * We currently only support version 1.
     */
    *(ptr++) = config->nChunkFiles;
    *(ptr++) = config->nStatCaches;
    *(ptr++) = config->nDataCaches;
    *(ptr++) = config->nVolumeCaches;
    *(ptr++) = config->firstChunkSize;
    *(ptr++) = config->otherChunkSize;
    *(ptr++) = config->cacheSize;
    *(ptr++) = config->setTime;
    *(ptr++) = config->memCache;

}
 

/*------------------------------------------------------------------------
 * EXPORTED SRXAFSCB_GetCacheConfig
 *
 * Description:
 *      Routine to return parameters used to initialize client cache.
 *      Client may request any format version. Server may not return
 *      format version greater than version requested by client.
 *
 * Arguments:
 *      a_call:        Ptr to Rx call on which this request came in.
 *      callerVersion: Data format version desired by the client.
 *      serverVersion: Data format version of output data.
 *      configCount:   Number bytes allocated for output data.
 *      config:        Client cache configuration.
 *
 * Returns:
 *      0 on success
 *
 * Environment:
 *      Nothing interesting.
 *
 * Side Effects:
 *      As advertised.
 *------------------------------------------------------------------------*/

int SRXAFSCB_GetCacheConfig(struct rx_call *callp,
                            afs_uint32 callerVersion,
                            afs_uint32 *serverVersion,
                            afs_uint32 *configCount,
                            cacheConfig *config)
{
    afs_uint32 *t_config;
    size_t allocsize;
    extern cm_initparams_v1 cm_initParams;
    struct rx_connection *connp;
    struct rx_peer *peerp;
    unsigned long host = 0;
    unsigned short port = 0;

    MUTEX_ENTER(&callp->lock);

    if ((connp = rx_ConnectionOf(callp)) && (peerp = rx_PeerOf(connp))) {
        host = rx_HostOf(peerp);
        port = rx_PortOf(peerp);
    }

    osi_Log2(afsd_logp, "SRXAFSCB_GetCacheConfig from host 0x%x port %d - version 1 only",
             ntohl(host), ntohs(port));

    /*
     * Currently only support version 1
     */
    allocsize = sizeof(cm_initparams_v1);
    t_config = (afs_uint32 *)malloc(allocsize);

    afs_MarshallCacheConfig(callerVersion, &cm_initParams, t_config);

    *serverVersion = AFS_CLIENT_RETRIEVAL_FIRST_EDITION;
#ifdef DEBUG
#ifndef SIZE_MAX
#define SIZE_MAX UINT_MAX
#endif
    osi_assert(allocsize < SIZE_MAX);
#endif
    *configCount = (afs_uint32)allocsize;
    config->cacheConfig_val = t_config;
    config->cacheConfig_len = (*configCount)/sizeof(afs_uint32);

    MUTEX_EXIT(&callp->lock);
    return 0;
}

/* called by afsd without any locks to initialize this module */
void cm_InitCallback(void)
{
    lock_InitializeRWLock(&cm_callbackLock, "cm_callbackLock");
    cm_activeCallbackGrantingCalls = 0;
}

/* called with locked scp; tells us whether we've got a callback.
 * Expirations are checked by a background daemon so as to make
 * this function as inexpensive as possible
 */
int cm_HaveCallback(cm_scache_t *scp)
{
#ifdef AFS_FREELANCE_CLIENT
    // yj: we handle callbacks specially for callbacks on the root directory
    // Since it's local, we almost always say that we have callback on it
    // The only time we send back a 0 is if we're need to initialize or
    // reinitialize the fake directory

    // There are 2 state variables cm_fakeGettingCallback and cm_fakeDirCallback
    // cm_fakeGettingCallback is 1 if we're in the process of initialization and
    // hence should return false. it's 0 otherwise
    // cm_fakeDirCallback is 0 if we haven't loaded the fake directory, it's 1
    // if the fake directory is loaded and this is the first time cm_HaveCallback
    // is called since then. We return false in this case to allow cm_GetCallback
    // to be called because cm_GetCallback has some initialization work to do.
    // If cm_fakeDirCallback is 2, then it means that the fake directory is in
    // good shape and we simply return true, provided no change is detected.
    int fdc, fgc;

    if (cm_freelanceEnabled && 
         scp->fid.cell==AFS_FAKE_ROOT_CELL_ID && scp->fid.volume==AFS_FAKE_ROOT_VOL_ID) {
        /* if it's something on /afs */
        if (!(scp->fid.vnode==0x1 && scp->fid.unique==0x1)) {
            /* if it's not root.afs */
            return 1;
        }

        lock_ObtainMutex(&cm_Freelance_Lock);
        fdc = cm_fakeDirCallback;
        fgc = cm_fakeGettingCallback;
        lock_ReleaseMutex(&cm_Freelance_Lock);
            
        if (fdc==1) {   // first call since init
            return 0;
        } else if (fdc==2 && !fgc) {    // we're in good shape
            if (cm_getLocalMountPointChange()) {        // check for changes
                cm_clearLocalMountPointChange(); // clear the changefile
                lock_ReleaseMutex(&scp->mx);      // this is re-locked in reInitLocalMountPoints
                cm_reInitLocalMountPoints();    // start reinit
                lock_ObtainMutex(&scp->mx);      // now get the lock back 
                return 0;
            }
            return 1;                   // no change
        }
        return 0;
    }
#endif

    if (scp->cbServerp != NULL)
        return 1;
    else 
        return 0;
}

/* need to detect a broken callback that races with our obtaining a callback.
 * Need to be able to do this even if we don't know the file ID of the file
 * we're breaking the callback on at the time we start the acquisition of the
 * callback (as in the case where we are creating a file).
 *
 * So, we start by writing down the count of the # of callbacks we've received
 * so far, and bumping a global counter of the # of callback granting calls
 * outstanding (all done under cm_callbackLock).
 *
 * When we're back from the call, we look at all of the callback revokes with
 * counter numbers greater than the one we recorded in our caller's structure,
 * and replay those that are higher than when we started the call.
 * 
 * We free all the structures in the queue when the count of the # of outstanding
 * callback-granting calls drops to zero.
 *
 * We call this function with the scp locked, too, but in its current implementation,
 * this knowledge is not used.
 */
void cm_StartCallbackGrantingCall(cm_scache_t *scp, cm_callbackRequest_t *cbrp)
{
    lock_ObtainWrite(&cm_callbackLock);
    cbrp->callbackCount = cm_callbackCount;
    cm_activeCallbackGrantingCalls++;
    cbrp->startTime = osi_Time();
    cbrp->serverp = NULL;
    lock_ReleaseWrite(&cm_callbackLock);
}

/* Called at the end of a callback-granting call, to remove the callback
 * info from the scache entry, if necessary.
 *
 * Called with scp locked, so we can discard the callbacks easily with
 * this locking hierarchy.
 */
void cm_EndCallbackGrantingCall(cm_scache_t *scp, cm_callbackRequest_t *cbrp,
                                AFSCallBack *cbp, long flags)
{
    cm_racingRevokes_t *revp;           /* where we are */
    cm_racingRevokes_t *nrevp;          /* where we'll be next */
    int freeFlag;
    cm_server_t * serverp = NULL;
    int discardScp = 0;

    lock_ObtainWrite(&cm_callbackLock);
    if (flags & CM_CALLBACK_MAINTAINCOUNT) {
        osi_assert(cm_activeCallbackGrantingCalls > 0);
    }
    else {
        osi_assert(cm_activeCallbackGrantingCalls-- > 0);
    }
    if (cm_activeCallbackGrantingCalls == 0) 
        freeFlag = 1;
    else 
        freeFlag = 0;

    /* record the callback; we'll clear it below if we really lose it */
    if (cbrp) {
        if (scp) {
            if (scp->cbServerp != cbrp->serverp) {
                serverp = scp->cbServerp;
                if (!freeFlag)
                    cm_GetServer(cbrp->serverp);
                scp->cbServerp = cbrp->serverp;
            } else {
                if (freeFlag)
                    serverp = cbrp->serverp;
            }
            scp->cbExpires = cbrp->startTime + cbp->ExpirationTime;
        } else {
            if (freeFlag)
                serverp = cbrp->serverp;
        }
        if (freeFlag)
            cbrp->serverp = NULL;
    }

    /* a callback was actually revoked during our granting call, so
     * run down the list of revoked fids, looking for ours.
     * If activeCallbackGrantingCalls is zero, free the elements, too.
     *
     * May need to go through entire list just to do the freeing.
     */
    for (revp = cm_racingRevokesp; revp; revp = nrevp) {
        nrevp = (cm_racingRevokes_t *) osi_QNext(&revp->q);
        /* if this callback came in later than when we started the
         * callback-granting call, and if this fid is the right fid,
         * then clear the callback.
         */
        if (scp && cbrp && cbrp->callbackCount != cm_callbackCount
             && revp->callbackCount > cbrp->callbackCount
             && (( scp->fid.volume == revp->fid.volume &&
                   scp->fid.vnode == revp->fid.vnode &&
                   scp->fid.unique == revp->fid.unique)
                  ||
                  ((revp->flags & CM_RACINGFLAG_CANCELVOL) &&
                    scp->fid.volume == revp->fid.volume)
                  ||
                  (revp->flags & CM_RACINGFLAG_CANCELALL))) {
            /* this one matches */
            osi_Log4(afsd_logp,
                      "Racing revoke scp 0x%p old cbc %d rev cbc %d cur cbc %d",
                      scp,
                      cbrp->callbackCount, revp->callbackCount,
                      cm_callbackCount);
            discardScp = 1;
        }
        if (freeFlag) 
            free(revp);
    }

    /* if we freed the list, zap the pointer to it */
    if (freeFlag) 
        cm_racingRevokesp = NULL;

    lock_ReleaseWrite(&cm_callbackLock);

    if ( discardScp ) {
        cm_DiscardSCache(scp);
        lock_ReleaseMutex(&scp->mx);
        cm_CallbackNotifyChange(scp);
        lock_ObtainMutex(&scp->mx);
    } 

    if ( serverp ) {
        lock_ObtainWrite(&cm_serverLock);
        cm_FreeServer(serverp);
        lock_ReleaseWrite(&cm_serverLock);
    }
}

/* if flags is 1, we want to force the code to make one call, anyway.
 * called with locked scp; returns with same.
 */
long cm_GetCallback(cm_scache_t *scp, struct cm_user *userp,
                    struct cm_req *reqp, long flags)
{
    long code = 0;
    cm_conn_t *connp = NULL;
    AFSFetchStatus afsStatus;
    AFSVolSync volSync;
    AFSCallBack callback;
    AFSFid tfid;
    cm_callbackRequest_t cbr;
    int mustCall;
    cm_fid_t sfid;
    struct rx_connection * callp = NULL;
    int syncop_done = 0;

    osi_Log4(afsd_logp, "GetCallback scp 0x%p cell %d vol %d flags %lX", 
             scp, scp->fid.cell, scp->fid.volume, flags);

#ifdef AFS_FREELANCE_CLIENT
    // The case where a callback is needed on /afs is handled
    // specially. We need to fetch the status by calling
    // cm_MergeStatus and mark that cm_fakeDirCallback is 2
    if (cm_freelanceEnabled) {
        if (scp->fid.cell==AFS_FAKE_ROOT_CELL_ID &&
             scp->fid.volume==AFS_FAKE_ROOT_VOL_ID &&
             scp->fid.unique==0x1 &&
             scp->fid.vnode==0x1) {
            
            // Start by indicating that we're in the process
            // of fetching the callback
            lock_ObtainMutex(&cm_Freelance_Lock);
            osi_Log0(afsd_logp,"cm_getGetCallback fakeGettingCallback=1");
            cm_fakeGettingCallback = 1;
            lock_ReleaseMutex(&cm_Freelance_Lock);

            // Fetch the status info 
            cm_MergeStatus(NULL, scp, &afsStatus, &volSync, userp, 0);

            // Indicate that the callback is not done
            lock_ObtainMutex(&cm_Freelance_Lock);
            osi_Log0(afsd_logp,"cm_getGetCallback fakeDirCallback=2");
            cm_fakeDirCallback = 2;

            // Indicate that we're no longer fetching the callback
            osi_Log0(afsd_logp,"cm_getGetCallback fakeGettingCallback=0");
            cm_fakeGettingCallback = 0;
            lock_ReleaseMutex(&cm_Freelance_Lock);

            return 0;
        }

        if (scp->fid.cell==AFS_FAKE_ROOT_CELL_ID && scp->fid.volume==AFS_FAKE_ROOT_VOL_ID) {
            osi_Log0(afsd_logp,"cm_getcallback should NEVER EVER get here... ");
        }
    }
#endif /* AFS_FREELANCE_CLIENT */
        
    mustCall = (flags & 1);
    cm_AFSFidFromFid(&tfid, &scp->fid);
    while (1) {
        if (!mustCall && cm_HaveCallback(scp))
            break;

        /* turn off mustCall, since it has now forced us past the check above */
        mustCall = 0;

        /* otherwise, we have to make an RPC to get the status */
        if (!syncop_done) {
            code = cm_SyncOp(scp, NULL, userp, reqp, 0, 
                             CM_SCACHESYNC_FETCHSTATUS | CM_SCACHESYNC_GETCALLBACK);
            if (code)
                break;
            syncop_done = 1;
        }
        cm_StartCallbackGrantingCall(scp, &cbr);
        sfid = scp->fid;
        lock_ReleaseMutex(&scp->mx);
                
        /* now make the RPC */
        osi_Log4(afsd_logp, "CALL FetchStatus scp 0x%p vol %u vn %u uniq %u", 
                 scp, sfid.volume, sfid.vnode, sfid.unique);
        do {
            code = cm_ConnFromFID(&sfid, userp, reqp, &connp);
            if (code) 
                continue;

            callp = cm_GetRxConn(connp);
            code = RXAFS_FetchStatus(callp, &tfid,
                                     &afsStatus, &callback, &volSync);
            rx_PutConnection(callp);

        } while (cm_Analyze(connp, userp, reqp, &sfid, &volSync, NULL,
                            &cbr, code));
        code = cm_MapRPCError(code, reqp);
        if (code)
            osi_Log4(afsd_logp, "CALL FetchStatus FAILURE code 0x%x scp 0x%p vol %u vn %u", 
                     code, scp, scp->fid.volume, scp->fid.vnode);
        else
            osi_Log4(afsd_logp, "CALL FetchStatus SUCCESS scp 0x%p vol %u vn %u uniq %u", 
                     scp, scp->fid.volume, scp->fid.vnode, scp->fid.unique);

        lock_ObtainMutex(&scp->mx);
        if (code == 0) {
            cm_EndCallbackGrantingCall(scp, &cbr, &callback, 0);
            cm_MergeStatus(NULL, scp, &afsStatus, &volSync, userp, 0);
        } else {
            cm_EndCallbackGrantingCall(NULL, &cbr, NULL, 0);
        }

        /* if we got an error, return to caller */
        if (code)
            break;
    }

    if (syncop_done)
        cm_SyncOpDone(scp, NULL, CM_SCACHESYNC_FETCHSTATUS | CM_SCACHESYNC_GETCALLBACK);
    
    if (code) {
        osi_Log2(afsd_logp, "GetCallback Failed code 0x%x scp 0x%p -->",code, scp);
        osi_Log4(afsd_logp, "            cell %u vol %u vn %u uniq %u",
                 scp->fid.cell, scp->fid.volume, scp->fid.vnode, scp->fid.unique);
    } else {
        osi_Log3(afsd_logp, "GetCallback Complete scp 0x%p cell %d vol %d", 
                  scp, scp->fid.cell, scp->fid.volume);
    }

    return code;
}

/* called periodically by cm_daemon to shut down use of expired callbacks */
void cm_CheckCBExpiration(void)
{
    int i;
    cm_scache_t *scp;
    time_t now;
        
    osi_Log0(afsd_logp, "CheckCBExpiration");

    now = osi_Time();
    lock_ObtainWrite(&cm_scacheLock);
    for (i=0; i<cm_data.scacheHashTableSize; i++) {
        for (scp = cm_data.scacheHashTablep[i]; scp; scp=scp->nextp) {
            cm_HoldSCacheNoLock(scp);
            if (scp->cbExpires > 0 && (scp->cbServerp == NULL || now > scp->cbExpires)) {
                lock_ReleaseWrite(&cm_scacheLock);
                osi_Log4(afsd_logp, "Callback Expiration Discarding SCache scp 0x%p vol %u vn %u uniq %u", 
                          scp, scp->fid.volume, scp->fid.vnode, scp->fid.unique);
                lock_ObtainMutex(&scp->mx);
                cm_DiscardSCache(scp);
                lock_ReleaseMutex(&scp->mx);
                cm_CallbackNotifyChange(scp);
                lock_ObtainWrite(&cm_scacheLock);
            }
            cm_ReleaseSCacheNoLock(scp);
        }
    }
    lock_ReleaseWrite(&cm_scacheLock);

    osi_Log0(afsd_logp, "CheckCBExpiration Complete");
}


void 
cm_GiveUpAllCallbacks(cm_server_t *tsp)
{
    long code;
    cm_conn_t *connp;
    struct rx_connection * rxconnp;

    if (tsp->type == CM_SERVER_FILE) {
        code = cm_ConnByServer(tsp, cm_rootUserp, &connp);
        if (code == 0) {
            rxconnp = cm_GetRxConn(connp);
            code = RXAFS_GiveUpAllCallBacks(rxconnp);
            rx_PutConnection(rxconnp);
        }
    }
}

void
cm_GiveUpAllCallbacksAllServers(void)
{
    cm_server_t *tsp;

    lock_ObtainWrite(&cm_serverLock);
    for (tsp = cm_allServersp; tsp; tsp = tsp->allNextp) {
        cm_GetServerNoLock(tsp);
        lock_ReleaseWrite(&cm_serverLock);
        cm_GiveUpAllCallbacks(tsp);
        lock_ObtainWrite(&cm_serverLock);
        cm_PutServerNoLock(tsp);
    }
    lock_ReleaseWrite(&cm_serverLock);
}