[apple/network_cmds.git] / rpc_lockd.tproj / lockd_lock.c

/*      $NetBSD: lockd_lock.c,v 1.5 2000/11/21 03:47:41 enami Exp $     */
/*      $FreeBSD: src/usr.sbin/rpc.lockd/lockd_lock.c,v 1.10 2002/03/22 19:57:09 alfred Exp $ */

/*
 * Copyright (c) 2001 Andrew P. Lentvorski, Jr.
 * Copyright (c) 2000 Manuel Bouyer.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */

#define LOCKD_DEBUG

#include <stdio.h>
#ifdef LOCKD_DEBUG
#include <stdarg.h>
#endif
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <syslog.h>
#include <errno.h>
#include <string.h>
#include <signal.h>
#include <rpc/rpc.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/param.h>
#include <sys/mount.h>
#include <sys/wait.h>
#include <rpcsvc/sm_inter.h>
#include <rpcsvc/nlm_prot.h>

#include "lockd.h"
#include "lockd_lock.h"

#define MAXOBJECTSIZE 64
#define MAXBUFFERSIZE 1024

/*
 * A set of utilities for managing file locking
 *
 * XXX: All locks are in a linked list, a better structure should be used
 * to improve search/access effeciency.
 */

/* struct describing a lock */
struct file_lock {
        LIST_ENTRY(file_lock) nfslocklist;
        netobj filehandle; /* NFS filehandle */
        struct sockaddr *addr;
        struct nlm4_holder client; /* lock holder */
        u_int64_t granted_cookie;
        int nsm_status; /* status from the remote lock manager */
        int status; /* lock status, see below */
        int flags; /* lock flags, see lockd_lock.h */
        int blocking; /* blocking lock or not */
        char client_name[SM_MAXSTRLEN]; /* client_name is really variable length and must be last! */
};

LIST_HEAD(nfslocklist_head, file_lock);
struct nfslocklist_head nfslocklist_head = LIST_HEAD_INITIALIZER(nfslocklist_head);

LIST_HEAD(blockedlocklist_head, file_lock);
struct blockedlocklist_head blockedlocklist_head = LIST_HEAD_INITIALIZER(blockedlocklist_head);

/* struct describing a share reservation */
struct file_share {
        LIST_ENTRY(file_share) nfssharelist;
        netobj oh; /* share holder */
        short mode;
        short access;
        char client_name[SM_MAXSTRLEN]; /* name is really variable length and must be last! */
};
LIST_HEAD(nfssharelist_head, file_share);

/* Struct describing a file with share reservations */
struct sharefile {
        LIST_ENTRY(sharefile) sharefilelist;
        netobj filehandle; /* Local access filehandle */
        int fd; /* file descriptor: remains open until no more shares */
        int refcount;
        struct nfssharelist_head sharelist_head;
};
LIST_HEAD(nfssharefilelist_head, sharefile);
struct nfssharefilelist_head nfssharefilelist_head = LIST_HEAD_INITIALIZER(nfssharefilelist_head);

/* lock status */
#define LKST_LOCKED     1 /* lock is locked */
/* XXX: Is this flag file specific or lock specific? */
#define LKST_WAITING    2 /* file is already locked by another host */
#define LKST_PROCESSING 3 /* child is trying to aquire the lock */
#define LKST_DYING      4 /* must dies when we get news from the child */

/* struct describing a monitored host */
struct host {
        TAILQ_ENTRY(host) hostlst;
        int refcnt;
        time_t lastuse;
        struct sockaddr addr;
        char name[SM_MAXSTRLEN]; /* name is really variable length and must be last! */
};
/* list of hosts we monitor */
TAILQ_HEAD(hostlst_head, host);
struct hostlst_head hostlst_head = TAILQ_HEAD_INITIALIZER(hostlst_head);
struct hostlst_head hostlst_unref = TAILQ_HEAD_INITIALIZER(hostlst_unref);

int host_expire = 60;   /* seconds */
time_t currsec;
u_int64_t send_granted_cookie = 0;

/*
 * File monitoring handlers
 * XXX: These might be able to be removed when kevent support
 * is placed into the hardware lock/unlock routines.  (ie.
 * let the kernel do all the file monitoring)
 */

/* Struct describing a monitored file */
struct monfile {
        LIST_ENTRY(monfile) monfilelist;
        netobj filehandle; /* Local access filehandle */
        int fd; /* file descriptor: remains open until unlock! */
        int refcount;
        int exclusive;
};

/* List of files we monitor */
LIST_HEAD(monfilelist_head, monfile);
struct monfilelist_head monfilelist_head = LIST_HEAD_INITIALIZER(monfilelist_head);

static int debugdelay = 0;

enum nfslock_status { NFS_GRANTED = 0, NFS_GRANTED_DUPLICATE,
                      NFS_DENIED, NFS_DENIED_NOLOCK,
                      NFS_RESERR };

enum hwlock_status { HW_GRANTED = 0, HW_GRANTED_DUPLICATE,
                     HW_DENIED, HW_DENIED_NOLOCK, 
                     HW_STALEFH, HW_READONLY, HW_RESERR };

enum partialfilelock_status { PFL_GRANTED=0, PFL_GRANTED_DUPLICATE, PFL_DENIED,
                              PFL_NFSDENIED, PFL_NFSBLOCKED, PFL_NFSDENIED_NOLOCK, PFL_NFSRESERR, 
                              PFL_HWDENIED,  PFL_HWBLOCKED,  PFL_HWDENIED_NOLOCK, PFL_HWRESERR,
                              PFL_HWDENIED_STALEFH, PFL_HWDENIED_READONLY };

enum LFLAGS {LEDGE_LEFT, LEDGE_LBOUNDARY, LEDGE_INSIDE, LEDGE_RBOUNDARY, LEDGE_RIGHT};
enum RFLAGS {REDGE_LEFT, REDGE_LBOUNDARY, REDGE_INSIDE, REDGE_RBOUNDARY, REDGE_RIGHT};
/* XXX: WARNING! I HAVE OVERLOADED THIS STATUS ENUM!  SPLIT IT APART INTO TWO */
enum split_status {SPL_DISJOINT=0, SPL_LOCK1=1, SPL_LOCK2=2, SPL_CONTAINED=4, SPL_RESERR=8};

enum partialfilelock_status lock_partialfilelock(struct file_lock *fl);

int send_granted(struct file_lock *fl, int opcode);
void siglock(void);
void sigunlock(void);
void destroy_lock_host(struct host *ihp);
static void monitor_lock_host(const char *hostname, const struct sockaddr *addr);

void    copy_nlm4_lock_to_nlm4_holder(const struct nlm4_lock *src,
    const bool_t exclusive, struct nlm4_holder *dest);
struct file_lock *      allocate_file_lock(const netobj *lockowner,
    const netobj *filehandle, const struct sockaddr *addr,
    const char *caller_name);
void    deallocate_file_lock(struct file_lock *fl);
void    fill_file_lock(struct file_lock *fl,
    const bool_t exclusive, const int32_t svid,
    const u_int64_t offset, const u_int64_t len,
    const int state, const int status, const int flags, const int blocking);
int     regions_overlap(const u_int64_t start1, const u_int64_t len1,
    const u_int64_t start2, const u_int64_t len2);;
enum split_status  region_compare(const u_int64_t starte, const u_int64_t lene,
    const u_int64_t startu, const u_int64_t lenu,
    u_int64_t *start1, u_int64_t *len1, u_int64_t *start2, u_int64_t *len2);
int     same_netobj(const netobj *n0, const netobj *n1);
int     same_filelock_identity(const struct file_lock *fl0,
    const struct file_lock *fl2);

static void debuglog(char const *fmt, ...);
void dump_static_object(const unsigned char* object, const int sizeof_object,
                        unsigned char* hbuff, const int sizeof_hbuff,
                        unsigned char* cbuff, const int sizeof_cbuff);
void dump_netobj(const struct netobj *nobj);
void dump_filelock(const struct file_lock *fl);
struct file_lock *      get_lock_matching_unlock(const struct file_lock *fl);
enum nfslock_status     test_nfslock(const struct file_lock *fl,
    struct file_lock **conflicting_fl);
enum nfslock_status     lock_nfslock(struct file_lock *fl);
enum nfslock_status     delete_nfslock(struct file_lock *fl);
enum nfslock_status     unlock_nfslock(const struct file_lock *fl,
    struct file_lock **released_lock, struct file_lock **left_lock,
    struct file_lock **right_lock);
enum hwlock_status lock_hwlock(struct file_lock *fl);
enum split_status split_nfslock(const struct file_lock *exist_lock,
    const struct file_lock *unlock_lock, struct file_lock **left_lock,
    struct file_lock **right_lock);
void    add_blockingfilelock(struct file_lock *fl);
enum hwlock_status      unlock_hwlock(const struct file_lock *fl);
enum hwlock_status      test_hwlock(const struct file_lock *fl,
    struct file_lock **conflicting_fl); 
void    remove_blockingfilelock(struct file_lock *fl);
void    clear_blockingfilelock(const char *hostname);
void    retry_blockingfilelocklist(netobj *fh);
enum partialfilelock_status     unlock_partialfilelock(
    const struct file_lock *fl);
void    clear_partialfilelock(const char *hostname);
enum partialfilelock_status     test_partialfilelock(
    const struct file_lock *fl, struct file_lock **conflicting_fl);
enum nlm4_stats do_test(struct file_lock *fl, struct file_lock **conflicting_fl);
enum nlm4_stats do_unlock(struct file_lock *fl);
enum nlm4_stats do_lock(struct file_lock *fl);
void    do_clear(const char *hostname);


void
debuglog(char const *fmt, ...)
{
        va_list ap;

        if (debug_level < 1) {
                return;
        }

        sleep(debugdelay);

        va_start(ap, fmt);
        vsyslog(LOG_DEBUG, fmt, ap);
        va_end(ap);
}

void
dump_static_object(object, size_object, hbuff, size_hbuff, cbuff, size_cbuff)
        const unsigned char *object;
        const int size_object;
        unsigned char *hbuff;
        const int size_hbuff;
        unsigned char *cbuff;
        const int size_cbuff;
{ 
        int i, objectsize;

        if (debug_level < 2) {
                return;
        }

        objectsize = size_object;

        if (objectsize == 0) {
                debuglog("object is size 0\n");
        } else {
                if (objectsize > MAXOBJECTSIZE) {
                        debuglog("Object of size %d being clamped"
                            "to size %d\n", objectsize, MAXOBJECTSIZE);
                        objectsize = MAXOBJECTSIZE;
                }
                
                if (hbuff != NULL) {
                        if (size_hbuff < objectsize*2+1) {
                                debuglog("Hbuff not large enough."
                                    "  Increase size\n");
                        } else {
                                for(i=0;i<objectsize;i++) {
                                        sprintf(hbuff+i*2,"%02x",*(object+i));
                                }
                                *(hbuff+i*2) = '\0';
                        }
                }
                
                if (cbuff != NULL) {
                        if (size_cbuff < objectsize+1) {
                                debuglog("Cbuff not large enough."
                                    "  Increase Size\n");
                        }
                        
                        for(i=0;i<objectsize;i++) {
                                if (*(object+i) >= 32 && *(object+i) <= 127) {
                                        *(cbuff+i) = *(object+i);
                                } else {
                                        *(cbuff+i) = '.';
                                }
                        }
                        *(cbuff+i) = '\0';
                }
        }
}

void
dump_netobj(const struct netobj *nobj)
{
        char hbuff[MAXBUFFERSIZE*2];
        char cbuff[MAXBUFFERSIZE];

        if (debug_level < 2) {
                return;
        }

        if (nobj == NULL) {
                debuglog("Null netobj pointer\n");
        }
        else if (nobj->n_len == 0) {
                debuglog("Size zero netobj\n");
        } else {
                dump_static_object(nobj->n_bytes, nobj->n_len,
                    hbuff, sizeof(hbuff), cbuff, sizeof(cbuff));
                debuglog("netobj: len: %d  data: %s :::  %s\n",
                    nobj->n_len, hbuff, cbuff);
        }
}

/* #define DUMP_FILELOCK_VERBOSE */
void
dump_filelock(const struct file_lock *fl)
{
#ifdef DUMP_FILELOCK_VERBOSE
        char hbuff[MAXBUFFERSIZE*2];
        char cbuff[MAXBUFFERSIZE];
#endif

        if (debug_level < 2) {
                return;
        }

        if (fl != NULL) {
                debuglog("Dumping file lock structure @ %p\n", fl);

#ifdef DUMP_FILELOCK_VERBOSE
                dump_static_object((unsigned char *)&fl->filehandle.n_bytes,
                    fl->filehandle.n_len, hbuff, sizeof(hbuff),
                    cbuff, sizeof(cbuff));
                debuglog("Filehandle: %8s  :::  %8s\n", hbuff, cbuff);
#endif
                
                debuglog("Dumping nlm4_holder:\n"
                    "exc: %x  svid: %x  offset:len %llx:%llx\n",
                    fl->client.exclusive, fl->client.svid,
                    fl->client.l_offset, fl->client.l_len);

#ifdef DUMP_FILELOCK_VERBOSE
                debuglog("Dumping client identity:\n");
                dump_netobj(&fl->client.oh);
                
                debuglog("nsm: %d  status: %d  flags: %d  locker: %d"
                    "  fd:  %d\n", fl->nsm_status, fl->status,
                    fl->flags, fl->locker, fl->fd);
#endif
        } else {
                debuglog("NULL file lock structure\n");
        }
}

void
copy_nlm4_lock_to_nlm4_holder(src, exclusive, dest)
        const struct nlm4_lock *src;
        const bool_t exclusive;
        struct nlm4_holder *dest;
{

        dest->exclusive = exclusive;
        dest->oh.n_len = src->oh.n_len;
        dest->oh.n_bytes = src->oh.n_bytes;
        dest->svid = src->svid;
        dest->l_offset = src->l_offset;
        dest->l_len = src->l_len;
}


size_t
strnlen(const char *s, size_t len)
{
    size_t n;

    for (n = 0;  s[n] != 0 && n < len; n++)
        ;
    return n;
}

/*
 * allocate_file_lock: Create a lock with the given parameters
 */

struct file_lock *
allocate_file_lock(const netobj *lockowner, const netobj *filehandle,
                   const struct sockaddr *addr, const char *caller_name)
{
        struct file_lock *newfl;
        size_t n;

        /* Beware of rubbish input! */
        n = strnlen(caller_name, SM_MAXSTRLEN);
        if (n == SM_MAXSTRLEN) {
                return NULL;
        }

        newfl = malloc(sizeof(*newfl) - sizeof(newfl->client_name) + n + 1);
        if (newfl == NULL) {
                return NULL;
        }
        bzero(newfl, sizeof(*newfl) - sizeof(newfl->client_name));
        memcpy(newfl->client_name, caller_name, n);
        newfl->client_name[n] = 0;

        newfl->client.oh.n_bytes = malloc(lockowner->n_len);
        if (newfl->client.oh.n_bytes == NULL) {
                free(newfl);
                return NULL;
        }
        newfl->client.oh.n_len = lockowner->n_len;
        bcopy(lockowner->n_bytes, newfl->client.oh.n_bytes, lockowner->n_len);

        newfl->filehandle.n_bytes = malloc(filehandle->n_len);
        if (newfl->filehandle.n_bytes == NULL) {
                free(newfl->client.oh.n_bytes);
                free(newfl);
                return NULL;
        }
        newfl->filehandle.n_len = filehandle->n_len;
        bcopy(filehandle->n_bytes, newfl->filehandle.n_bytes, filehandle->n_len);

        newfl->addr = malloc(addr->sa_len);
        if (newfl->addr == NULL) {
                free(newfl->client.oh.n_bytes);
                free(newfl);
                return NULL;
        }
        memcpy(newfl->addr, addr, addr->sa_len);

        return newfl;
}

/*
 * file_file_lock: Force creation of a valid file lock
 */
void
fill_file_lock(struct file_lock *fl,
    const bool_t exclusive, const int32_t svid,
    const u_int64_t offset, const u_int64_t len,
    const int state, const int status, const int flags, const int blocking)
{
        fl->client.exclusive = exclusive;
        fl->client.svid = svid;
        fl->client.l_offset = offset;
        fl->client.l_len = len;

        fl->nsm_status = state;
        fl->status = status;
        fl->flags = flags;
        fl->blocking = blocking;
}

/*
 * deallocate_file_lock: Free all storage associated with a file lock
 */
void
deallocate_file_lock(struct file_lock *fl)
{
        free(fl->addr);
        free(fl->client.oh.n_bytes);
        free(fl->filehandle.n_bytes);
        free(fl);
}

/*
 * regions_overlap(): This function examines the two provided regions for
 * overlap.
 */
int
regions_overlap(start1, len1, start2, len2)
        const u_int64_t start1, len1, start2, len2;
{
        u_int64_t d1,d2,d3,d4;
        enum split_status result;

        debuglog("Entering region overlap with vals: %llu:%llu--%llu:%llu\n",
                 start1, len1, start2, len2);

        result = region_compare(start1, len1, start2, len2,
            &d1, &d2, &d3, &d4);

        debuglog("Exiting region overlap with val: %d\n",result);

        if (result == SPL_DISJOINT) {
                return 0;
        } else {
                return 1;
        }

        return (result);
}

/*
 * region_compare(): Examine lock regions and split appropriately
 *
 * XXX: Fix 64 bit overflow problems
 * XXX: Check to make sure I got *ALL* the cases. 
 * XXX: This DESPERATELY needs a regression test.
 */
enum split_status
region_compare(starte, lene, startu, lenu,
    start1, len1, start2, len2)
        const u_int64_t starte, lene, startu, lenu;
        u_int64_t *start1, *len1, *start2, *len2;
{
        /*
         * Please pay attention to the sequential exclusions
         * of the if statements!!!
         */
        enum LFLAGS lflags;
        enum RFLAGS rflags;
        enum split_status retval;

        retval = SPL_DISJOINT;

        if (lene == 0 && lenu == 0) {
                /* Examine left edge of locker */
                if (startu < starte) {
                        lflags = LEDGE_LEFT;
                } else if (startu == starte) {
                        lflags = LEDGE_LBOUNDARY;
                } else {
                        lflags = LEDGE_INSIDE;
                }

                rflags = REDGE_RBOUNDARY; /* Both are infiinite */

                if (lflags == LEDGE_INSIDE) {
                        *start1 = starte;
                        *len1 = startu - starte;
                }

                if (lflags == LEDGE_LEFT || lflags == LEDGE_LBOUNDARY) {
                        retval = SPL_CONTAINED;
                } else {
                        retval = SPL_LOCK1;
                }
        } else if (lene == 0 && lenu != 0) {
                /* Established lock is infinite */
                /* Examine left edge of unlocker */
                if (startu < starte) {
                        lflags = LEDGE_LEFT;
                } else if (startu == starte) {
                        lflags = LEDGE_LBOUNDARY;
                } else if (startu > starte) {
                        lflags = LEDGE_INSIDE;
                }

                /* Examine right edge of unlocker */
                if (startu + lenu < starte) {
                        /* Right edge of unlocker left of established lock */
                        rflags = REDGE_LEFT;
                        return SPL_DISJOINT;
                } else if (startu + lenu == starte) {
                        /* Right edge of unlocker on start of established lock */
                        rflags = REDGE_LBOUNDARY;
                        return SPL_DISJOINT;
                } else { /* Infinifty is right of finity */
                        /* Right edge of unlocker inside established lock */
                        rflags = REDGE_INSIDE;
                }

                if (lflags == LEDGE_INSIDE) {
                        *start1 = starte;
                        *len1 = startu - starte;
                        retval |= SPL_LOCK1;
                }

                if (rflags == REDGE_INSIDE) {
                        /* Create right lock */
                        *start2 = startu+lenu;
                        *len2 = 0;
                        retval |= SPL_LOCK2;
                }
        } else if (lene != 0 && lenu == 0) {
                /* Unlocker is infinite */
                /* Examine left edge of unlocker */
                if (startu < starte) {
                        lflags = LEDGE_LEFT;
                        retval = SPL_CONTAINED;
                        return retval;
                } else if (startu == starte) {
                        lflags = LEDGE_LBOUNDARY;
                        retval = SPL_CONTAINED;
                        return retval;
                } else if ((startu > starte) && (startu < starte + lene - 1)) {
                        lflags = LEDGE_INSIDE;
                } else if (startu == starte + lene - 1) {
                        lflags = LEDGE_RBOUNDARY;
                } else { /* startu > starte + lene -1 */
                        lflags = LEDGE_RIGHT;
                        return SPL_DISJOINT;
                }

                rflags = REDGE_RIGHT; /* Infinity is right of finity */

                if (lflags == LEDGE_INSIDE || lflags == LEDGE_RBOUNDARY) {
                        *start1 = starte;
                        *len1 = startu - starte;
                        retval |= SPL_LOCK1;
                        return retval;
                }

        } else {
                /* Both locks are finite */

                /* Examine left edge of unlocker */
                if (startu < starte) {
                        lflags = LEDGE_LEFT;
                } else if (startu == starte) {
                        lflags = LEDGE_LBOUNDARY;
                } else if ((startu > starte) && (startu < starte + lene - 1)) {
                        lflags = LEDGE_INSIDE;
                } else if (startu == starte + lene - 1) {
                        lflags = LEDGE_RBOUNDARY;
                } else { /* startu > starte + lene -1 */
                        lflags = LEDGE_RIGHT;
                        return SPL_DISJOINT;
                }

                /* Examine right edge of unlocker */
                if (startu + lenu < starte) {
                        /* Right edge of unlocker left of established lock */
                        rflags = REDGE_LEFT;
                        return SPL_DISJOINT;
                } else if (startu + lenu == starte) {
                        /* Right edge of unlocker on start of established lock */
                        rflags = REDGE_LBOUNDARY;
                        return SPL_DISJOINT;
                } else if (startu + lenu < starte + lene) {
                        /* Right edge of unlocker inside established lock */
                        rflags = REDGE_INSIDE;
                } else if (startu + lenu == starte + lene) {
                        /* Right edge of unlocker on right edge of established lock */
                        rflags = REDGE_RBOUNDARY;
                } else { /* startu + lenu > starte + lene */
                        /* Right edge of unlocker is right of established lock */
                        rflags = REDGE_RIGHT;
                }

                if (lflags == LEDGE_INSIDE || lflags == LEDGE_RBOUNDARY) {
                        /* Create left lock */
                        *start1 = starte;
                        *len1 = (startu - starte);
                        retval |= SPL_LOCK1;
                }

                if (rflags == REDGE_INSIDE) {
                        /* Create right lock */
                        *start2 = startu+lenu;
                        *len2 = starte+lene-(startu+lenu);
                        retval |= SPL_LOCK2;
                }

                if ((lflags == LEDGE_LEFT || lflags == LEDGE_LBOUNDARY) &&
                    (rflags == REDGE_RBOUNDARY || rflags == REDGE_RIGHT)) {
                        retval = SPL_CONTAINED;
                }
        }

        return retval;
}

/*
 * same_netobj: Compares the apprpriate bits of a netobj for identity
 */
int
same_netobj(const netobj *n0, const netobj *n1)
{
        int retval;

        retval = 0;

        debuglog("Entering netobj identity check\n");

        if (n0->n_len == n1->n_len) {
                debuglog("Preliminary length check passed\n");
                retval = !bcmp(n0->n_bytes, n1->n_bytes, n0->n_len);
                debuglog("netobj %smatch\n", retval ? "" : "mis");
        }
        
        return (retval);
}

/*
 * same_filelock_identity: Compares the appropriate bits of a file_lock
 */
int
same_filelock_identity(fl0, fl1)
        const struct file_lock *fl0, *fl1;
{
        int retval;

        retval = 0;

        debuglog("Checking filelock identity\n");

        /*
         * Check process ids and host information.
         */
        retval = (fl0->client.svid == fl1->client.svid &&
            same_netobj(&(fl0->client.oh), &(fl1->client.oh)));

        debuglog("Exiting checking filelock identity: retval: %d\n",retval);

        return (retval);
}

/*
 * Below here are routines associated with manipulating the NFS
 * lock list.
 */

/*
 * get_lock_matching_unlock: Return a lock which matches the given unlock lock
 *                           or NULL otherwise
 * XXX: It is a shame that this duplicates so much code from test_nfslock.
 */
struct file_lock *
get_lock_matching_unlock(const struct file_lock *fl)
{
        struct file_lock *ifl; /* Iterator */

        debuglog("Entering lock_matching_unlock\n");
        debuglog("********Dump of fl*****************\n");
        dump_filelock(fl);

        LIST_FOREACH(ifl, &nfslocklist_head, nfslocklist) {
                debuglog("Pointer to file lock: %p\n",ifl);

                debuglog("****Dump of ifl****\n");
                dump_filelock(ifl);
                debuglog("*******************\n");

                /*
                 * XXX: It is conceivable that someone could use the NLM RPC
                 * system to directly access filehandles.  This may be a
                 * security hazard as the filehandle code may bypass normal
                 * file access controls
                 */
                if (fl->filehandle.n_len != ifl->filehandle.n_len)
                        continue;
                if (bcmp(fl->filehandle.n_bytes, ifl->filehandle.n_bytes,
                        fl->filehandle.n_len))
                        continue;

                debuglog("matching_unlock: Filehandles match, "
                    "checking regions\n");

                /* Filehandles match, check for region overlap */
                if (!regions_overlap(fl->client.l_offset, fl->client.l_len,
                        ifl->client.l_offset, ifl->client.l_len))
                        continue;
               
                debuglog("matching_unlock: Region overlap"
                    " found %llu : %llu -- %llu : %llu\n",
                    fl->client.l_offset,fl->client.l_len,
                    ifl->client.l_offset,ifl->client.l_len);

                /* Regions overlap, check the identity */
                if (!same_filelock_identity(fl,ifl))
                        continue;

                debuglog("matching_unlock: Duplicate lock id.  Granting\n");
                return (ifl);
        }

        debuglog("Exiting lock_matching_unlock\n");

        return (NULL);
}

/*
 * test_nfslock: check for NFS lock in lock list
 *
 * This routine makes the following assumptions:
 *    1) Nothing will adjust the lock list during a lookup
 *
 * This routine has an intersting quirk which bit me hard.
 * The conflicting_fl is the pointer to the conflicting lock.
 * However, to modify the "*pointer* to the conflicting lock" rather
 * that the "conflicting lock itself" one must pass in a "pointer to
 * the pointer of the conflicting lock".  Gross.
 */

enum nfslock_status
test_nfslock(const struct file_lock *fl, struct file_lock **conflicting_fl)
{
        struct file_lock *ifl; /* Iterator */
        enum nfslock_status retval;

        debuglog("Entering test_nfslock\n");

        retval = NFS_GRANTED;
        (*conflicting_fl) = NULL;

        debuglog("Entering lock search loop\n");

        debuglog("***********************************\n");
        debuglog("Dumping match filelock\n");
        debuglog("***********************************\n");
        dump_filelock(fl);
        debuglog("***********************************\n");

        LIST_FOREACH(ifl, &nfslocklist_head, nfslocklist) {
                if (retval == NFS_DENIED)
                        break;

                debuglog("Top of lock loop\n");
                debuglog("Pointer to file lock: %p\n",ifl);
                
                debuglog("***********************************\n");
                debuglog("Dumping test filelock\n");
                debuglog("***********************************\n");
                dump_filelock(ifl);
                debuglog("***********************************\n");

                /*
                 * XXX: It is conceivable that someone could use the NLM RPC
                 * system to directly access filehandles.  This may be a
                 * security hazard as the filehandle code may bypass normal
                 * file access controls
                 */
                if (fl->filehandle.n_len != ifl->filehandle.n_len)
                        continue;
                if (bcmp(fl->filehandle.n_bytes, ifl->filehandle.n_bytes,
                        fl->filehandle.n_len))
                        continue;

                debuglog("test_nfslock: filehandle match found\n");

                /* Filehandles match, check for region overlap */
                if (!regions_overlap(fl->client.l_offset, fl->client.l_len,
                        ifl->client.l_offset, ifl->client.l_len))
                        continue;

                debuglog("test_nfslock: Region overlap found"
                    " %llu : %llu -- %llu : %llu\n",
                    fl->client.l_offset,fl->client.l_len,
                    ifl->client.l_offset,ifl->client.l_len);

                /* Regions overlap, check the exclusivity */
                if (!(fl->client.exclusive || ifl->client.exclusive))
                        continue;
               
                debuglog("test_nfslock: Exclusivity failure: %d %d\n",
                    fl->client.exclusive,
                    ifl->client.exclusive);

                if (same_filelock_identity(fl,ifl)) {
                        debuglog("test_nfslock: Duplicate id.  Granting\n");
                        (*conflicting_fl) = ifl;
                        retval = NFS_GRANTED_DUPLICATE;
                } else {
                        /* locking attempt fails */
                        debuglog("test_nfslock: Lock attempt failed\n");
                        debuglog("Desired lock\n");
                        dump_filelock(fl);
                        debuglog("Conflicting lock\n");
                        dump_filelock(ifl);
                        (*conflicting_fl) = ifl;
                        retval = NFS_DENIED;
                }
        }
        
        debuglog("Dumping file locks\n");
        debuglog("Exiting test_nfslock\n");
        
        return (retval);
}

/*
 * lock_nfslock: attempt to create a lock in the NFS lock list
 *
 * This routine tests whether the lock will be granted and then adds
 * the entry to the lock list if so.
 * 
 * Argument fl gets modified as its list housekeeping entries get modified
 * upon insertion into the NFS lock list
 *
 * This routine makes several assumptions:
 *    1) It is perfectly happy to grant a duplicate lock from the same pid.
 *       While this seems to be intuitively wrong, it is required for proper
 *       Posix semantics during unlock.  It is absolutely imperative to not
 *       unlock the main lock before the two child locks are established. Thus,
 *       one has be be able to create duplicate locks over an existing lock
 *    2) It currently accepts duplicate locks from the same id,pid
 */

enum nfslock_status
lock_nfslock(struct file_lock *fl)
{
        enum nfslock_status retval;
        struct file_lock *dummy_fl;

        dummy_fl = NULL;

        debuglog("Entering lock_nfslock...\n");

        retval = test_nfslock(fl,&dummy_fl);

        if (retval == NFS_GRANTED || retval == NFS_GRANTED_DUPLICATE) {
                debuglog("Inserting lock...\n");
                dump_filelock(fl);
                LIST_INSERT_HEAD(&nfslocklist_head, fl, nfslocklist);
        }

        debuglog("Exiting lock_nfslock...\n");

        return (retval);
}

/*
 * delete_nfslock: delete an NFS lock list entry
 *
 * This routine is used to delete a lock out of the NFS lock list
 * without regard to status, underlying locks, regions or anything else
 *
 * Note that this routine *does not deallocate memory* of the lock.
 * It just disconnects it from the list.  The lock can then be used
 * by other routines without fear of trashing the list.
 */

enum nfslock_status
delete_nfslock(struct file_lock *fl)
{

        LIST_REMOVE(fl, nfslocklist);

        return (NFS_GRANTED);
}

enum split_status
split_nfslock(exist_lock, unlock_lock, left_lock, right_lock)
        const struct file_lock *exist_lock, *unlock_lock;
        struct file_lock **left_lock, **right_lock;
{
        u_int64_t start1, len1, start2, len2;
        enum split_status spstatus;

        spstatus = region_compare(exist_lock->client.l_offset, exist_lock->client.l_len,
            unlock_lock->client.l_offset, unlock_lock->client.l_len,
            &start1, &len1, &start2, &len2);

        if ((spstatus & SPL_LOCK1) != 0) {
                *left_lock = allocate_file_lock(&exist_lock->client.oh, &exist_lock->filehandle, exist_lock->addr, exist_lock->client_name);
                if (*left_lock == NULL) {
                        debuglog("Unable to allocate resource for split 1\n");
                        return SPL_RESERR;
                }

                fill_file_lock(*left_lock,
                    exist_lock->client.exclusive, exist_lock->client.svid,
                    start1, len1,
                    exist_lock->nsm_status,
                    exist_lock->status, exist_lock->flags, exist_lock->blocking);
        }

        if ((spstatus & SPL_LOCK2) != 0) {
                *right_lock = allocate_file_lock(&exist_lock->client.oh, &exist_lock->filehandle, exist_lock->addr, exist_lock->client_name);
                if (*right_lock == NULL) {
                        debuglog("Unable to allocate resource for split 1\n");
                        if (*left_lock != NULL) {
                                deallocate_file_lock(*left_lock);
                        }
                        return SPL_RESERR;
                }

                fill_file_lock(*right_lock,
                    exist_lock->client.exclusive, exist_lock->client.svid,
                    start2, len2,
                    exist_lock->nsm_status,
                    exist_lock->status, exist_lock->flags, exist_lock->blocking);
        }

        return spstatus;
}

enum nfslock_status
unlock_nfslock(fl, released_lock, left_lock, right_lock)
        const struct file_lock *fl;
        struct file_lock **released_lock;
        struct file_lock **left_lock;
        struct file_lock **right_lock;
{
        struct file_lock *mfl; /* Matching file lock */
        enum nfslock_status retval;
        enum split_status spstatus;

        debuglog("Entering unlock_nfslock\n");

        *released_lock = NULL;
        *left_lock = NULL;
        *right_lock = NULL;

        retval = NFS_DENIED_NOLOCK;

        debuglog("Attempting to match lock...\n");
        mfl = get_lock_matching_unlock(fl);

        if (mfl != NULL) {
                debuglog("Unlock matched.  Querying for split\n");

                spstatus = split_nfslock(mfl, fl, left_lock, right_lock);

                debuglog("Split returned %d %p %p %p %p\n",spstatus,mfl,fl,*left_lock,*right_lock);
                debuglog("********Split dumps********");
                dump_filelock(mfl);
                dump_filelock(fl);
                dump_filelock(*left_lock);
                dump_filelock(*right_lock);
                debuglog("********End Split dumps********");

                if (spstatus == SPL_RESERR) {
                        if (*left_lock != NULL) {
                                deallocate_file_lock(*left_lock);
                                *left_lock = NULL;
                        }

                        if (*right_lock != NULL) {
                                deallocate_file_lock(*right_lock);
                                *right_lock = NULL;
                        }

                        return NFS_RESERR;
                }

                /* Insert new locks from split if required */
                if (*left_lock != NULL) {
                        debuglog("Split left activated\n");
                        LIST_INSERT_HEAD(&nfslocklist_head, *left_lock, nfslocklist);
                }

                if (*right_lock != NULL) {
                        debuglog("Split right activated\n");
                        LIST_INSERT_HEAD(&nfslocklist_head, *right_lock, nfslocklist);
                }

                /* Unlock the lock since it matches identity */
                LIST_REMOVE(mfl, nfslocklist);
                *released_lock = mfl;
                retval = NFS_GRANTED;
        }

        debuglog("Exiting unlock_nfslock\n");

        return retval;
}

/*
 * Below here are the routines for manipulating the file lock directly
 * on the disk hardware itself
 */
enum hwlock_status
lock_hwlock(struct file_lock *fl)
{
        struct monfile *imf,*nmf;
        int lflags, flerror;
        fhandle_t fh;

        /* Scan to see if filehandle already present */
        LIST_FOREACH(imf, &monfilelist_head, monfilelist) {
                if ((fl->filehandle.n_len == imf->filehandle.n_len) &&
                    (bcmp(fl->filehandle.n_bytes, imf->filehandle.n_bytes,
                        fl->filehandle.n_len) == 0)) {
                        /* imf is the correct filehandle */
                        break;
                }
        }

        /*
         * Filehandle already exists (we control the file)
         * *AND* NFS has already cleared the lock for availability
         * Grant it and bump the refcount.
         */
        if (imf != NULL) {
                ++(imf->refcount);
                return (HW_GRANTED);
        }

        /* No filehandle found, create and go */
        nmf = malloc(sizeof(struct monfile));
        if (nmf == NULL) {
                debuglog("hwlock resource allocation failure\n");
                return (HW_RESERR);
        }
        nmf->filehandle.n_bytes = malloc(fl->filehandle.n_len);
        if (nmf->filehandle.n_bytes == NULL) {
                debuglog("hwlock resource allocation failure\n");
                free(nmf);
                return (HW_RESERR);
        }

        if (fl->filehandle.n_len > NFS_MAX_FH_SIZE) {
                debuglog("hwlock: bad fh length %d (from %16s): %32s\n",
                    fl->filehandle.n_len, fl->client_name, strerror(errno));
                free(nmf->filehandle.n_bytes);
                free(nmf);
                return (HW_STALEFH);
        }
        fh.fh_len = fl->filehandle.n_len;
        bcopy(fl->filehandle.n_bytes, fh.fh_data, fh.fh_len);

        /* XXX: Is O_RDWR always the correct mode? */
        nmf->fd = fhopen(&fh, O_RDWR);
        if (nmf->fd < 0) {
                debuglog("fhopen failed (from %16s): %32s\n",
                    fl->client_name, strerror(errno));
                free(nmf->filehandle.n_bytes);
                free(nmf);
                switch (errno) {
                case ESTALE:
                        return (HW_STALEFH);
                case EROFS:
                        return (HW_READONLY);
                default:
                        return (HW_RESERR);
                }
        }

        /* File opened correctly, fill the monitor struct */
        nmf->filehandle.n_len = fl->filehandle.n_len;
        bcopy(fl->filehandle.n_bytes, nmf->filehandle.n_bytes, fl->filehandle.n_len);
        nmf->refcount = 1;
        nmf->exclusive = fl->client.exclusive;

        lflags = (nmf->exclusive == 1) ?
            (LOCK_EX | LOCK_NB) : (LOCK_SH | LOCK_NB);

        flerror = flock(nmf->fd, lflags);

        if (flerror != 0) {
                debuglog("flock failed (from %16s): %32s\n",
                    fl->client_name, strerror(errno));
                close(nmf->fd);
                free(nmf->filehandle.n_bytes);
                free(nmf);
                switch (errno) {
                case EAGAIN:
                        return (HW_DENIED);
                case ESTALE:
                        return (HW_STALEFH);
                case EROFS:
                        return (HW_READONLY);
                default:
                        return (HW_RESERR);
                        break;
                }
        }

        /* File opened and locked */
        LIST_INSERT_HEAD(&monfilelist_head, nmf, monfilelist);

        debuglog("flock succeeded (from %16s)\n", fl->client_name);
        return (HW_GRANTED);
}
                
enum hwlock_status
unlock_hwlock(const struct file_lock *fl)
{
        struct monfile *imf;

        debuglog("Entering unlock_hwlock\n");
        debuglog("Entering loop interation\n");

        /* Scan to see if filehandle already present */
        LIST_FOREACH(imf, &monfilelist_head, monfilelist) {
                if ((fl->filehandle.n_len == imf->filehandle.n_len) &&
                    (bcmp(fl->filehandle.n_bytes, imf->filehandle.n_bytes,
                        fl->filehandle.n_len) == 0)) {
                        /* imf is the correct filehandle */
                        break;
                }
        }

        debuglog("Completed iteration.  Proceeding\n");

        if (imf == NULL) {
                /* No lock found */
                debuglog("Exiting unlock_hwlock (HW_DENIED_NOLOCK)\n");
                return (HW_DENIED_NOLOCK);
        }

        /* Lock found */
        --imf->refcount;

        if (imf->refcount < 0) {
                debuglog("Negative hardware reference count\n");
        }

        if (imf->refcount <= 0) {
                close(imf->fd);
                LIST_REMOVE(imf, monfilelist);
                free(imf->filehandle.n_bytes);
                free(imf);
        }
        debuglog("Exiting unlock_hwlock (HW_GRANTED)\n");
        return (HW_GRANTED);
}

enum hwlock_status
test_hwlock(fl, conflicting_fl)
        const struct file_lock *fl __unused;
        struct file_lock **conflicting_fl __unused;
{

        /*
         * XXX: lock tests on hardware are not required until
         * true partial file testing is done on the underlying file
         */
        return (HW_RESERR);
}



/*
 * Below here are routines for manipulating blocked lock requests
 * They should only be called from the XXX_partialfilelock routines
 * if at all possible
 */

void
add_blockingfilelock(struct file_lock *fl)
{
        struct file_lock *ifl, *nfl;

        debuglog("Entering add_blockingfilelock\n");

        /*
         * Check for a duplicate lock request.
         * If found, deallocate the older request.
         */
        ifl = LIST_FIRST(&blockedlocklist_head);
        for (; ifl != NULL; ifl = nfl) {
                debuglog("Pointer to file lock: %p\n",ifl);
                debuglog("****Dump of ifl****\n");
                dump_filelock(ifl);
                debuglog("*******************\n");

                nfl = LIST_NEXT(ifl, nfslocklist);

                if (fl->filehandle.n_len != ifl->filehandle.n_len)
                        continue;
                if (bcmp(fl->filehandle.n_bytes, ifl->filehandle.n_bytes,
                        fl->filehandle.n_len))
                        continue;

                /* Filehandles match, check region */
                if ((fl->client.l_offset != ifl->client.l_offset) ||
                    (fl->client.l_len != ifl->client.l_len))
                        continue;

                /* Regions match, check the identity */
                if (!same_filelock_identity(fl,ifl))
                        continue;

                debuglog("add_blockingfilelock: removing duplicate lock request.\n");
                remove_blockingfilelock(ifl);
                deallocate_file_lock(ifl);
                break;
        }

        /*
         * Clear the blocking flag so that it can be reused without
         * adding it to the blocking queue a second time
         */

        fl->blocking = 0;
        LIST_INSERT_HEAD(&blockedlocklist_head, fl, nfslocklist);

        debuglog("Exiting add_blockingfilelock\n");
}

void
remove_blockingfilelock(struct file_lock *fl)
{

        debuglog("Entering remove_blockingfilelock\n");

        LIST_REMOVE(fl, nfslocklist);

        debuglog("Exiting remove_blockingfilelock\n");
}

void
clear_blockingfilelock(const char *hostname)
{
        struct file_lock *ifl,*nfl;

        /*
         * Normally, LIST_FOREACH is called for, but since
         * the current element *is* the iterator, deleting it
         * would mess up the iteration.  Thus, a next element
         * must be used explicitly
         */

        ifl = LIST_FIRST(&blockedlocklist_head);

        while (ifl != NULL) {
                nfl = LIST_NEXT(ifl, nfslocklist);

                if (strncmp(hostname, ifl->client_name, SM_MAXSTRLEN) == 0) {
                        remove_blockingfilelock(ifl);
                        deallocate_file_lock(ifl);
                }

                ifl = nfl;
        }
}

int need_retry_blocked_locks = 0; /* need to call retry_blockingfilelocklist() */

void
retry_blockingfilelocklist(netobj *fh)
{
        /*
         * If fh is given, then retry just the locks with the
         * same filehandle in the blocked list.
         * Otherwise, simply retry all locks in the blocked list.
         */
        struct file_lock *ifl, *nfl, *pfl; /* Iterator */
        enum partialfilelock_status pflstatus;
        int rv;

        debuglog("Entering retry_blockingfilelocklist\n");

        need_retry_blocked_locks = 0;

        pfl = NULL;
        ifl = LIST_FIRST(&blockedlocklist_head);
        debuglog("Iterator choice %p\n",ifl);

        while (ifl != NULL) {
                /*
                 * SUBTLE BUG: The next element must be worked out before the
                 * current element has been moved
                 */
                nfl = LIST_NEXT(ifl, nfslocklist);
                debuglog("Iterator choice %p\n",ifl);
                debuglog("Prev iterator choice %p\n",pfl);
                debuglog("Next iterator choice %p\n",nfl);

                /* if given a filehandle, only retry locks for the same filehandle */
                if (fh && !same_netobj(fh, &ifl->filehandle)) {
                        ifl = nfl;
                        continue;
                }

                /*
                 * SUBTLE BUG: The file_lock must be removed from the
                 * old list so that it's list pointers get disconnected
                 * before being allowed to participate in the new list
                 * which will automatically add it in if necessary.
                 */

                LIST_REMOVE(ifl, nfslocklist);
                pflstatus = lock_partialfilelock(ifl);
                
                if (pflstatus == PFL_GRANTED || pflstatus == PFL_GRANTED_DUPLICATE) {
                        debuglog("Granted blocked lock\n");
                        /* lock granted and is now being used */
                        rv = send_granted(ifl, 0);
                        if (rv) {
                                /*
                                 * Uh oh... the NLM_GRANTED message failed.
                                 * About the only thing we can do is drop the lock.
                                 * Note: this could be bad if the error was only
                                 * transient.  Hopefully, if the client is still
                                 * waiting for the lock, they will resend the request.
                                 */
                                do_unlock(ifl);
                                /* ifl is NO LONGER VALID AT THIS POINT */
                        }
                } else if (pflstatus == PFL_HWDENIED_STALEFH) {
                        /*
                         * Uh oh...
                         * It would be nice if we could inform the client of
                         * this error.  Unfortunately, there's no way to do
                         * that in the NLM protocol (can't send "granted"
                         * message with an error and there's no "never going
                         * to be granted" message).
                         *
                         * Since there's no chance of this blocked request ever
                         * succeeding, we drop the lock request rather than
                         * needlessly keeping it around just to rot forever in
                         * the blocked lock list.
                         *
                         * Hopefully, if the client is still waiting for the lock,
                         * they will resend the request (and get an error then).
                         *
                         * XXX Note: PFL_HWDENIED_READONLY could potentially
                         * be handled this way as well, although that would
                         * only be an issue if a file system changed from
                         * read-write to read-only out from under a blocked
                         * lock request, and that's far less likely than a
                         * file disappearing out from under such a request.
                         */
                        deallocate_file_lock(ifl);
                        /* ifl is NO LONGER VALID AT THIS POINT */
                } else {
                        /* Reinsert lock back into same place in blocked list */
                        debuglog("Replacing blocked lock\n");
                        if (pfl != NULL)
                                LIST_INSERT_AFTER(pfl, ifl, nfslocklist);
                        else
                                /* ifl is the only elem. in the list */
                                LIST_INSERT_HEAD(&blockedlocklist_head, ifl, nfslocklist);
                }

                if (pflstatus == PFL_GRANTED || pflstatus == PFL_GRANTED_DUPLICATE ||
                    pflstatus == PFL_HWDENIED_STALEFH) {
                        /* If ifl was permanently removed from the list, (e.g it */
                        /* was granted or dropped), pfl should remain where it's at. */
                } else {
                        /* If ifl was left in the list, (e.g it was reinserted back */
                        /* in place), pfl should simply be moved forward to be ifl */
                        pfl = ifl;
                }
                /* Valid increment behavior regardless of state of ifl */
                ifl = nfl;
        }

        debuglog("Exiting retry_blockingfilelocklist\n");
}

/*
 * Below here are routines associated with manipulating all
 * aspects of the partial file locking system (list, hardware, etc.)
 */

/*
 * Please note that lock monitoring must be done at this level which
 * keeps track of *individual* lock requests on lock and unlock
 *
 * XXX: Split unlocking is going to make the unlock code miserable
 */

/*
 * lock_partialfilelock:
 *
 * Argument fl gets modified as its list housekeeping entries get modified
 * upon insertion into the NFS lock list
 *
 * This routine makes several assumptions:
 * 1) It (will) pass locks through to flock to lock the entire underlying file
 *     and then parcel out NFS locks if it gets control of the file.
 *         This matches the old rpc.lockd file semantics (except where it
 *         is now more correct).  It is the safe solution, but will cause
 *         overly restrictive blocking if someone is trying to use the
 *         underlying files without using NFS.  This appears to be an
 *         acceptable tradeoff since most people use standalone NFS servers.
 * XXX: The right solution is probably kevent combined with fcntl
 *
 *    2) Nothing modifies the lock lists between testing and granting
 *           I have no idea whether this is a useful assumption or not
 */

enum partialfilelock_status
lock_partialfilelock(struct file_lock *fl)
{
        enum partialfilelock_status retval;
        enum nfslock_status lnlstatus;
        enum hwlock_status hwstatus;

        debuglog("Entering lock_partialfilelock\n");

        retval = PFL_DENIED;

        /*
         * Execute the NFS lock first, if possible, as it is significantly
         * easier and less expensive to undo than the filesystem lock
         */

        lnlstatus = lock_nfslock(fl);

        switch (lnlstatus) {
        case NFS_GRANTED:
        case NFS_GRANTED_DUPLICATE:
                /*
                 * At this point, the NFS lock is allocated and active.
                 * Remember to clean it up if the hardware lock fails
                 */
                hwstatus = lock_hwlock(fl);

                switch (hwstatus) {
                case HW_GRANTED:
                case HW_GRANTED_DUPLICATE:
                        debuglog("HW GRANTED\n");
                        /*
                         * XXX: Fixme: Check hwstatus for duplicate when
                         * true partial file locking and accounting is
                         * done on the hardware 
                         */
                        if (lnlstatus == NFS_GRANTED_DUPLICATE) {
                                retval = PFL_GRANTED_DUPLICATE;
                        } else {
                                retval = PFL_GRANTED;
                        }
                        if (fl->flags & LOCK_MON)
                                monitor_lock_host_by_name(fl->client_name);
                        break;
                case HW_RESERR:
                        debuglog("HW RESERR\n");
                        retval = PFL_HWRESERR;
                        break;
                case HW_DENIED:
                        debuglog("HW DENIED\n");
                        retval = PFL_HWDENIED;
                        break;
                case HW_DENIED_NOLOCK:
                        debuglog("HW DENIED NOLOCK\n");
                        retval = PFL_HWDENIED_NOLOCK;
                        break;
                case HW_STALEFH:
                        debuglog("HW STALE FH\n");
                        retval = PFL_HWDENIED_STALEFH;
                        break;
                case HW_READONLY:
                        debuglog("HW READONLY\n");
                        retval = PFL_HWDENIED_READONLY;
                        break;
                default:
                        debuglog("Unmatched hwstatus %d\n",hwstatus);
                        break;
                }

                if (retval != PFL_GRANTED &&
                    retval != PFL_GRANTED_DUPLICATE) {
                        /* Clean up the NFS lock */
                        debuglog("Deleting trial NFS lock\n");
                        delete_nfslock(fl);
                }
                break;
        case NFS_DENIED:
                retval = PFL_NFSDENIED;
                break;
        case NFS_RESERR:
                retval = PFL_NFSRESERR;
        default:
                debuglog("Unmatched lnlstatus %d\n");
                retval = PFL_NFSDENIED_NOLOCK;
                break;
        }

        /*
         * By the time fl reaches here, it is completely free again on
         * failure.  The NFS lock done before attempting the
         * hardware lock has been backed out
         */

        if (retval == PFL_NFSDENIED || retval == PFL_HWDENIED) {
                /* Once last chance to check the lock */
                if (fl->blocking == 1) {
                        if (retval == PFL_NFSDENIED) {
                                /* Queue the lock */
                                debuglog("BLOCKING LOCK RECEIVED\n");
                                retval = PFL_NFSBLOCKED;
                                add_blockingfilelock(fl);
                                dump_filelock(fl);
                        } else {
                                /* retval is okay as PFL_HWDENIED */
                                debuglog("BLOCKING LOCK DENIED IN HARDWARE\n");
                                dump_filelock(fl);
                        }
                } else {
                        /* Leave retval alone, it's already correct */
                        debuglog("Lock denied.  Non-blocking failure\n");
                        dump_filelock(fl);
                }
        }

        debuglog("Exiting lock_partialfilelock\n");

        return retval;
}

/*
 * unlock_partialfilelock:
 *
 * Given a file_lock, unlock all locks which match.
 *
 * Note that a given lock might have to unlock ITSELF!  See
 * clear_partialfilelock for example.
 */

enum partialfilelock_status
unlock_partialfilelock(const struct file_lock *fl)
{
        struct file_lock *lfl,*rfl,*releasedfl,*selffl;
        enum partialfilelock_status retval;
        enum nfslock_status unlstatus;
        enum hwlock_status unlhwstatus, lhwstatus;

        debuglog("Entering unlock_partialfilelock\n");

        selffl = NULL;
        lfl = NULL;
        rfl = NULL;
        releasedfl = NULL;
        retval = PFL_DENIED;

        /*
         * There are significant overlap and atomicity issues
         * with partially releasing a lock.  For example, releasing
         * part of an NFS shared lock does *not* always release the
         * corresponding part of the file since there is only one
         * rpc.lockd UID but multiple users could be requesting it
         * from NFS.  Also, an unlock request should never allow
         * another process to gain a lock on the remaining parts.
         * ie. Always apply the new locks before releasing the
         * old one
         */

        /*
         * Loop is required since multiple little locks
         * can be allocated and then deallocated with one
         * big unlock.
         *
         * The loop is required to be here so that the nfs &
         * hw subsystems do not need to communicate with one
         * one another
         */

        do {
                debuglog("Value of releasedfl: %p\n",releasedfl);
                /* lfl&rfl are created *AND* placed into the NFS lock list if required */
                unlstatus = unlock_nfslock(fl, &releasedfl, &lfl, &rfl);
                debuglog("Value of releasedfl: %p\n",releasedfl);


                /* XXX: This is grungy.  It should be refactored to be cleaner */
                if (lfl != NULL) {
                        lhwstatus = lock_hwlock(lfl);
                        if (lhwstatus != HW_GRANTED &&
                            lhwstatus != HW_GRANTED_DUPLICATE) {
                                debuglog("HW duplicate lock failure for left split\n");
                        }
                        if (lfl->flags & LOCK_MON)
                                monitor_lock_host_by_name(lfl->client_name);
                }

                if (rfl != NULL) {
                        lhwstatus = lock_hwlock(rfl);
                        if (lhwstatus != HW_GRANTED &&
                            lhwstatus != HW_GRANTED_DUPLICATE) {
                                debuglog("HW duplicate lock failure for right split\n");
                        }
                        if (rfl->flags & LOCK_MON)
                                monitor_lock_host_by_name(rfl->client_name);
                }

                switch (unlstatus) {
                case NFS_GRANTED:
                        /* Attempt to unlock on the hardware */
                        debuglog("NFS unlock granted.  Attempting hardware unlock\n");

                        /* This call *MUST NOT* unlock the two newly allocated locks */
                        unlhwstatus = unlock_hwlock(fl);
                        debuglog("HW unlock returned with code %d\n",unlhwstatus);
                        
                        switch (unlhwstatus) {
                        case HW_GRANTED:
                                debuglog("HW unlock granted\n");
                                if (releasedfl->flags & LOCK_MON)
                                        unmonitor_lock_host(releasedfl->client_name);
                                retval = PFL_GRANTED;
                                break;
                        case HW_DENIED_NOLOCK:
                                /* Huh?!?!  This shouldn't happen */
                                debuglog("HW unlock denied no lock\n");
                                retval = PFL_HWRESERR;
                                /* Break out of do-while */
                                unlstatus = NFS_RESERR;
                                break;
                        default:
                                debuglog("HW unlock failed\n");
                                retval = PFL_HWRESERR;
                                /* Break out of do-while */
                                unlstatus = NFS_RESERR;
                                break;
                        }
                        
                        debuglog("Exiting with status retval: %d\n",retval);
                        
                        // XXX sending granted messages before unlock response
                        // XXX causes unlock response to be corrupted?
                        // XXX Workaround is to move this to nlm_prot_svc.c
                        // XXX after the unlock response is sent.
                        // retry_blockingfilelocklist();
                        need_retry_blocked_locks = 1;
                        break;
                case NFS_DENIED_NOLOCK:
                        retval = PFL_GRANTED;
                        debuglog("All locks cleaned out\n");
                        break;
                default:
                        retval = PFL_NFSRESERR;
                        debuglog("NFS unlock failure\n");
                        dump_filelock(fl);
                        break;
                }

                if (releasedfl != NULL) {
                        if (fl == releasedfl) {
                                /*
                                 * XXX: YECHHH!!! Attempt to unlock self succeeded
                                 * but we can't deallocate the space yet.  This is what
                                 * happens when you don't write malloc and free together
                                 */
                                debuglog("Attempt to unlock self\n");
                                selffl = releasedfl;
                        } else {
                                /*
                                 * XXX: this deallocation *still* needs to migrate closer
                                 * to the allocation code way up in get_lock or the allocation
                                 * code needs to migrate down (violation of "When you write
                                 * malloc you must write free")
                                 */
                        
                                deallocate_file_lock(releasedfl);
                        }
                }

        } while (unlstatus == NFS_GRANTED);

        if (selffl != NULL) {
                /*
                 * This statement wipes out the incoming file lock (fl)
                 * in spite of the fact that it is declared const
                 */
                debuglog("WARNING!  Destroying incoming lock pointer\n");
                deallocate_file_lock(selffl);
        }

        debuglog("Exiting unlock_partialfilelock\n");

        return retval;
}

/*
 * clear_partialfilelock
 *
 * Normally called in response to statd state number change.
 * Wipe out all locks held by a host.  As a bonus, the act of
 * doing so should automatically clear their statd entries and
 * unmonitor the host.
 */

void 
clear_partialfilelock(const char *hostname)
{
        struct file_lock *ifl, *nfl;
        enum partialfilelock_status pfsret;

        /* Clear blocking file lock list */
        clear_blockingfilelock(hostname);

        /* do all required unlocks */
        /* Note that unlock can smash the current pointer to a lock */

        /*
         * Normally, LIST_FOREACH is called for, but since
         * the current element *is* the iterator, deleting it
         * would mess up the iteration.  Thus, a next element
         * must be used explicitly
         */
restart:
        ifl = LIST_FIRST(&nfslocklist_head);

        while (ifl != NULL) {
                nfl = LIST_NEXT(ifl, nfslocklist);

                if (strncmp(hostname, ifl->client_name, SM_MAXSTRLEN) == 0) {
                        /* Unlock destroys ifl out from underneath */
                        pfsret = unlock_partialfilelock(ifl);
                        if (pfsret != PFL_GRANTED) {
                                /* Uh oh... there was some sort of problem. */
                                /* If we restart the loop, we may get */
                                /* stuck here forever getting errors. */
                                /* So, let's just abort the whole scan. */
                                syslog(LOG_WARNING, "lock clearing for %s failed: %d",
                                        hostname, pfsret);
                                break;
                        }
                        /* ifl is NO LONGER VALID AT THIS POINT */
                        /* Note: the unlock may deallocate several existing locks. */
                        /* Therefore, we need to restart the scanning of the list, */
                        /* because nfl could be pointing to a freed lock. */
                        goto restart;
                }
                ifl = nfl;
        }
}

/*
 * test_partialfilelock:
 */
enum partialfilelock_status
test_partialfilelock(const struct file_lock *fl,
    struct file_lock **conflicting_fl)
{
        enum partialfilelock_status retval;
        enum nfslock_status teststatus;

        debuglog("Entering testpartialfilelock...\n");

        retval = PFL_DENIED;

        teststatus = test_nfslock(fl, conflicting_fl);
        debuglog("test_partialfilelock: teststatus %d\n",teststatus);

        if (teststatus == NFS_GRANTED || teststatus == NFS_GRANTED_DUPLICATE) {
                /* XXX: Add the underlying filesystem locking code */
                retval = (teststatus == NFS_GRANTED) ?
                    PFL_GRANTED : PFL_GRANTED_DUPLICATE;
                debuglog("Dumping locks...\n");
                dump_filelock(fl);
                dump_filelock(*conflicting_fl);
                debuglog("Done dumping locks...\n");
        } else {
                retval = PFL_NFSDENIED;
                debuglog("NFS test denied.\n");
                dump_filelock(fl);
                debuglog("Conflicting.\n");
                dump_filelock(*conflicting_fl);
        }

        debuglog("Exiting testpartialfilelock...\n");

        return retval;
}

/*
 * Below here are routines associated with translating the partial file locking
 * codes into useful codes to send back to the NFS RPC messaging system
 */

/*
 * These routines translate the (relatively) useful return codes back onto
 * the few return codes which the nlm subsystems wishes to trasmit
 */

enum nlm4_stats
do_test(struct file_lock *fl, struct file_lock **conflicting_fl)
{
        enum partialfilelock_status pfsret;
        enum nlm4_stats retval;

        debuglog("Entering do_test...\n");

        pfsret = test_partialfilelock(fl,conflicting_fl);

        switch (pfsret) {
        case PFL_GRANTED:
                debuglog("PFL test lock granted\n");
                dump_filelock(fl);
                dump_filelock(*conflicting_fl);
                retval = (fl->flags & LOCK_V4) ? nlm4_granted : nlm_granted;
                break;
        case PFL_GRANTED_DUPLICATE:
                debuglog("PFL test lock granted--duplicate id detected\n");
                dump_filelock(fl);
                dump_filelock(*conflicting_fl);
                debuglog("Clearing conflicting_fl for call semantics\n");
                *conflicting_fl = NULL;
                retval = (fl->flags & LOCK_V4) ? nlm4_granted : nlm_granted;
                break;
        case PFL_NFSDENIED:
        case PFL_HWDENIED:
                debuglog("PFL test lock denied\n");
                dump_filelock(fl);
                dump_filelock(*conflicting_fl);
                retval = (fl->flags & LOCK_V4) ? nlm4_denied : nlm_denied;
                break;
        case PFL_NFSRESERR:
        case PFL_HWRESERR:
                debuglog("PFL test lock resource fail\n");
                dump_filelock(fl);
                dump_filelock(*conflicting_fl);
                retval = (fl->flags & LOCK_V4) ? nlm4_denied_nolocks : nlm_denied_nolocks;
                break;
        default:
                debuglog("PFL test lock *FAILED*\n");
                dump_filelock(fl);
                dump_filelock(*conflicting_fl);
                retval = (fl->flags & LOCK_V4) ? nlm4_failed : nlm_denied;
                break;
        }

        debuglog("Exiting do_test...\n");

        return retval;
}

/*
 * do_lock: Try to acquire a lock
 *
 * This routine makes a distinction between NLM versions.  I am pretty
 * convinced that this should be abstracted out and bounced up a level
 */

enum nlm4_stats
do_lock(struct file_lock *fl)
{
        enum partialfilelock_status pfsret;
        enum nlm4_stats retval;

        debuglog("Entering do_lock...\n");

        pfsret = lock_partialfilelock(fl);

        switch (pfsret) {
        case PFL_GRANTED:
                debuglog("PFL lock granted");
                dump_filelock(fl);
                retval = (fl->flags & LOCK_V4) ? nlm4_granted : nlm_granted;
                break;
        case PFL_GRANTED_DUPLICATE:
                debuglog("PFL lock granted--duplicate id detected");
                dump_filelock(fl);
                retval = (fl->flags & LOCK_V4) ? nlm4_granted : nlm_granted;
                break;
        case PFL_NFSDENIED:
        case PFL_HWDENIED:
                debuglog("PFL_NFS lock denied");
                dump_filelock(fl);
                retval = (fl->flags & LOCK_V4) ? nlm4_denied : nlm_denied;
                break;
        case PFL_NFSBLOCKED:
        case PFL_HWBLOCKED:
                debuglog("PFL_NFS blocking lock denied.  Queued.\n");
                dump_filelock(fl);
                retval = (fl->flags & LOCK_V4) ? nlm4_blocked : nlm_blocked;
                break;
        case PFL_NFSRESERR:
        case PFL_HWRESERR:
        case PFL_NFSDENIED_NOLOCK:
        case PFL_HWDENIED_NOLOCK:
                debuglog("PFL lock resource alocation fail\n");
                dump_filelock(fl);
                retval = (fl->flags & LOCK_V4) ? nlm4_denied_nolocks : nlm_denied_nolocks;
                break;
        case PFL_HWDENIED_STALEFH:
                debuglog("PFL_NFS lock denied STALEFH");
                dump_filelock(fl);
                retval = (fl->flags & LOCK_V4) ? nlm4_stale_fh : nlm_denied;
                break;
        case PFL_HWDENIED_READONLY:
                debuglog("PFL_NFS lock denied READONLY");
                dump_filelock(fl);
                retval = (fl->flags & LOCK_V4) ? nlm4_rofs : nlm_denied;
                break;
        default:
                debuglog("PFL lock *FAILED*");
                dump_filelock(fl);
                retval = (fl->flags & LOCK_V4) ? nlm4_failed : nlm_denied;
                break;
        }

        debuglog("Exiting do_lock...\n");

        return retval;
}

enum nlm4_stats
do_unlock(struct file_lock *fl)
{
        enum partialfilelock_status pfsret;
        enum nlm4_stats retval;

        debuglog("Entering do_unlock...\n");
        pfsret = unlock_partialfilelock(fl);

        switch (pfsret) {
        case PFL_GRANTED:
                debuglog("PFL unlock granted");
                dump_filelock(fl);
                retval = (fl->flags & LOCK_V4) ? nlm4_granted : nlm_granted;
                break;
        case PFL_NFSDENIED:
        case PFL_HWDENIED:
                debuglog("PFL_NFS unlock denied");
                dump_filelock(fl);
                retval = (fl->flags & LOCK_V4) ? nlm4_denied : nlm_denied;
                break;
        case PFL_NFSDENIED_NOLOCK:
        case PFL_HWDENIED_NOLOCK:
                debuglog("PFL_NFS no lock found\n");
                retval = (fl->flags & LOCK_V4) ? nlm4_granted : nlm_granted;
                break;
        case PFL_NFSRESERR:
        case PFL_HWRESERR:
                debuglog("PFL unlock resource failure");
                dump_filelock(fl);
                retval = (fl->flags & LOCK_V4) ? nlm4_denied_nolocks : nlm_denied_nolocks;
                break;
        default:
                debuglog("PFL unlock *FAILED*");
                dump_filelock(fl);
                retval = (fl->flags & LOCK_V4) ? nlm4_failed : nlm_denied;
                break;
        }

        debuglog("Exiting do_unlock...\n");

        return retval;
}

/*
 * do_clear
 *
 * This routine is non-existent because it doesn't have a return code.
 * It is here for completeness in case someone *does* need to do return
 * codes later.  A decent compiler should optimize this away.
 */

void
do_clear(const char *hostname)
{

        clear_partialfilelock(hostname);
}

/*
 * The following routines are all called from the code which the
 * RPC layer invokes
 */

/*
 * testlock(): inform the caller if the requested lock would be granted
 *
 * returns NULL if lock would granted
 * returns pointer to a conflicting nlm4_holder if not
 */

struct nlm4_holder *
testlock(struct nlm4_lock *lock, bool_t exclusive, int flags __unused)
{
        struct file_lock test_fl, *conflicting_fl;

        if (lock->fh.n_len > NFS_MAX_FH_SIZE) {
                debuglog("received fhandle size %d, max size %d",
                    lock->fh.n_len, NFS_MAX_FH_SIZE);
                return NULL;
        }

        bzero(&test_fl, sizeof(test_fl));

        test_fl.filehandle.n_len = lock->fh.n_len;
        test_fl.filehandle.n_bytes = lock->fh.n_bytes;
        copy_nlm4_lock_to_nlm4_holder(lock, exclusive, &test_fl.client);

        siglock();
        do_test(&test_fl, &conflicting_fl);
        
        if (conflicting_fl == NULL) {
                debuglog("No conflicting lock found\n");
                sigunlock();
                return NULL;
        } else {
                debuglog("Found conflicting lock\n");
                dump_filelock(conflicting_fl);
                sigunlock();
                return (&conflicting_fl->client);
        }
}

/*
 * getlock: try to aquire the lock. 
 * If file is already locked and we can sleep, put the lock in the list with
 * status LKST_WAITING; it'll be processed later.
 * Otherwise try to lock. If we're allowed to block, fork a child which
 * will do the blocking lock.
 */

enum nlm4_stats
getlock(nlm4_lockargs *lckarg, struct svc_req *rqstp, const int flags)
{
        struct file_lock *newfl;
        enum nlm4_stats retval;

        debuglog("Entering getlock...\n");

        if (grace_expired == 0 && lckarg->reclaim == 0)
                return (flags & LOCK_V4) ?
                    nlm4_denied_grace_period : nlm_denied_grace_period;

        if (lckarg->alock.fh.n_len > NFS_MAX_FH_SIZE) {
                debuglog("received fhandle size %d, max size %d",
                    lckarg->alock.fh.n_len, NFS_MAX_FH_SIZE);
                return (flags & LOCK_V4) ? nlm4_failed : nlm_denied;
        }

        /* allocate new file_lock for this request */
        newfl = allocate_file_lock(&lckarg->alock.oh, &lckarg->alock.fh,
                                   (struct sockaddr *)svc_getcaller(rqstp->rq_xprt),
                                   lckarg->alock.caller_name);
        if (newfl == NULL) {
                syslog(LOG_NOTICE, "lock allocate failed: %s", strerror(errno));
                /* failed */
                return (flags & LOCK_V4) ?
                    nlm4_denied_nolocks : nlm_denied_nolocks;
        }

        fill_file_lock(newfl,
            lckarg->exclusive, lckarg->alock.svid, lckarg->alock.l_offset,
            lckarg->alock.l_len,
            lckarg->state, 0, flags, lckarg->block);
        
        /*
         * newfl is now fully constructed and deallocate_file_lock
         * can now be used to delete it
         */
        
        siglock();
        debuglog("Pointer to new lock is %p\n",newfl);

        retval = do_lock(newfl);

        debuglog("Pointer to new lock is %p\n",newfl);
        sigunlock();
        
        switch (retval)
                {
                case nlm4_granted:
                        /* case nlm_granted: is the same as nlm4_granted */
                        /* do_mon(lckarg->alock.caller_name); */
                        break;
                case nlm4_blocked:
                        /* case nlm_blocked: is the same as nlm4_blocked */
                        /* do_mon(lckarg->alock.caller_name); */
                        break;
                default:
                        deallocate_file_lock(newfl);
                        break;
                }

        debuglog("Exiting getlock...\n");

        return retval;
}


/* unlock a filehandle */
enum nlm4_stats
unlock(nlm4_lock *lock, const int flags)
{
        struct file_lock fl;
        enum nlm4_stats err;
        
        debuglog("Entering unlock...\n");

        if (lock->fh.n_len > NFS_MAX_FH_SIZE) {
                debuglog("received fhandle size %d, max size %d",
                    lock->fh.n_len, NFS_MAX_FH_SIZE);
                return (flags & LOCK_V4) ? nlm4_failed : nlm_denied;
        }
        
        siglock();
        
        bzero(&fl,sizeof(struct file_lock));
        fl.filehandle.n_len = lock->fh.n_len;
        fl.filehandle.n_bytes = lock->fh.n_bytes;
        
        copy_nlm4_lock_to_nlm4_holder(lock, 0, &fl.client);
        
        err = do_unlock(&fl);
        
        sigunlock();
        
        debuglog("Exiting unlock...\n");
        
        return err;
}

/* cancel a blocked lock request */
enum nlm4_stats
cancellock(nlm4_cancargs *args, const int flags)
{
        struct file_lock *ifl, *nfl;
        enum nlm4_stats err;

        debuglog("Entering cancellock...\n");

        if (args->alock.fh.n_len > NFS_MAX_FH_SIZE) {
                debuglog("received fhandle size %d, max size %d",
                    args->alock.fh.n_len, NFS_MAX_FH_SIZE);
                return (flags & LOCK_V4) ? nlm4_failed : nlm_denied;
        }

        siglock();

        err = (flags & LOCK_V4) ? nlm4_denied : nlm_denied;

        /*
         * scan blocked lock list for matching request and remove/destroy
         */
        ifl = LIST_FIRST(&blockedlocklist_head);
        for ( ; ifl != NULL; ifl = nfl) {
                nfl = LIST_NEXT(ifl, nfslocklist);

                /* compare lock fh - filehandle */
                if (!same_netobj(&args->alock.fh, &ifl->filehandle))
                        continue;

                /* compare lock caller_name - client_name */
                if (strncmp(args->alock.caller_name, ifl->client_name, SM_MAXSTRLEN))
                        continue;

                /* Note: done't compare cookie - client_cookie */
                /* The cookie may be specific to the cancel request */
                /* and not be the same as the one in the original lock request. */

                /* compare lock oh - client.oh */
                if (!same_netobj(&args->alock.oh, &ifl->client.oh))
                        continue;

                /* compare lock svid - client.svid */
                if (args->alock.svid != ifl->client.svid)
                        continue;

                /* compare lock l_offset - client.l_offset */
                if (args->alock.l_offset != ifl->client.l_offset)
                        continue;

                /* compare lock l_len - client.l_len */
                if (args->alock.l_len != ifl->client.l_len)
                        continue;

                /* compare exclusive - client.exclusive */
                if (args->exclusive != ifl->client.exclusive)
                        continue;

                /* got it */
                remove_blockingfilelock(ifl);
                deallocate_file_lock(ifl);
                err = (flags & LOCK_V4) ? nlm4_granted : nlm_granted;
                break;
        }

        sigunlock();

        debuglog("Exiting cancellock...\n");

        return err;
}


/*
 * XXX: The following monitor/unmonitor routines 
 * have not been extensively tested (ie. no regression
 * script exists like for the locking sections)
 */

/*
 * Find a lock host on a queue.  If found:
 *    bump the ref,
 *    bump the access time,
 *    dequeue it from the queue it was found on,
 *    enqueue it at the front of the "in use" queue.
 */
struct host *
get_lock_host(struct hostlst_head *hd, const char *hostname, const struct sockaddr *saddr)
{
        struct host *ihp;

        if (!hostname && !saddr)
                return (NULL);

        debuglog("get_lock_host %s\n", hostname ? hostname : "addr");
        TAILQ_FOREACH(ihp, hd, hostlst) {
                if (hostname && (strncmp(hostname, ihp->name, SM_MAXSTRLEN) != 0))
                        continue;
                if (saddr && addrcmp(saddr, &ihp->addr))
                        continue;
                TAILQ_REMOVE(hd, ihp, hostlst);
                /*
                 * Host is already monitored, so just bump the
                 * reference count.  But don't bump the reference
                 * count if we're adding additional client-side
                 * references.  Client-side monitors are done by
                 * address, are never unmonitored, and should only
                 * take one refcount.  Otherwise, repeated calls
                 * could cause the refcount to wrap.
                 */
                if (!saddr || !ihp->addr.sa_len)
                        ++ihp->refcnt;
                ihp->lastuse = currsec;
                /* Host should only be in the monitor list once */
                TAILQ_INSERT_HEAD(&hostlst_head, ihp, hostlst);
                break;
        }
        debuglog("get_lock_host %s %s\n",
            ihp == NULL ? "did not find" : "found", hostname ? hostname : "addr");
        return (ihp);
}

/*
 * monitor_lock_host: monitor lock hosts locally with a ref count and
 * inform statd
 */
void
monitor_lock_host_by_name(const char *hostname)
{
        struct host *ihp;

        debuglog("monitor_lock_host: %s\n", hostname);
        ihp = get_lock_host(&hostlst_head, hostname, NULL);
        if (ihp == NULL)
                ihp = get_lock_host(&hostlst_unref, hostname, NULL);
        if (ihp != NULL) {
                debuglog("Monitor_lock_host: %s (cached)\n", hostname);
                return;
        }

        monitor_lock_host(hostname, NULL);
}

void
monitor_lock_host_by_addr(const struct sockaddr *saddr)
{
        struct host *ihp;
        struct hostent *hp;
        char hostaddr[SM_MAXSTRLEN];
        struct sockaddr_in *sin = (struct sockaddr_in *)saddr;

        if (getnameinfo(saddr, saddr->sa_len, hostaddr, sizeof(hostaddr),
                        NULL, 0, NI_NUMERICHOST)) {
                debuglog("monitor_lock_host: bad address\n");
                return;
        }
        debuglog("monitor_lock_host: %s\n", hostaddr);
        ihp = get_lock_host(&hostlst_head, NULL, saddr);
        if (ihp == NULL)
                ihp = get_lock_host(&hostlst_unref, NULL, saddr);
        if (ihp != NULL) {
                debuglog("Monitor_lock_host: %s (cached)\n", ihp->name);
                return;
        }

        hp = gethostbyaddr((char*)&sin->sin_addr, sizeof(sin->sin_addr), AF_INET);
        if (hp) {
                monitor_lock_host(hp->h_name, saddr);
        } else {
                // herror(hostaddr);
                monitor_lock_host(hostaddr, saddr);
        }
}

static void
monitor_lock_host(const char *hostname, const struct sockaddr *saddr)
{
        struct host *nhp;
        struct mon smon;
        struct sm_stat_res sres;
        int rpcret, statflag;
        size_t n;

        rpcret = 0;
        statflag = 0;

        /* Host is not yet monitored, add it */
        debuglog("Monitor_lock_host: %s (creating)\n", hostname);
        n = strnlen(hostname, SM_MAXSTRLEN);
        if (n == SM_MAXSTRLEN) {
                debuglog("monitor_lock_host: hostname too long\n");
                return;
        }
        nhp = malloc(sizeof(*nhp) - sizeof(nhp->name) + n + 1);
        if (nhp == NULL) {
                debuglog("Unable to allocate entry for statd mon\n");
                return;
        }

        /* Allocated new host entry, now fill the fields */
        memcpy(nhp->name, hostname, n);
        nhp->name[n] = 0;
        nhp->refcnt = 1;
        nhp->lastuse = currsec;
        if (saddr) {
                bcopy(saddr, &nhp->addr, saddr->sa_len);
        } else {
                nhp->addr.sa_len = 0;
        }
        debuglog("Locally Monitoring host '%s'\n", hostname);

        debuglog("Attempting to tell statd\n");

        bzero(&smon,sizeof(smon));

        smon.mon_id.mon_name = nhp->name;
        smon.mon_id.my_id.my_name = "localhost\0";

        smon.mon_id.my_id.my_prog = NLM_PROG;
        smon.mon_id.my_id.my_vers = NLM_SM;
        smon.mon_id.my_id.my_proc = NLM_SM_NOTIFY;

        rpcret = callrpc("localhost", SM_PROG, SM_VERS, SM_MON, xdr_mon,
            &smon, xdr_sm_stat_res, &sres);

        if (rpcret == 0) {
                if (sres.res_stat == stat_fail) {
                        debuglog("Statd call failed\n");
                        statflag = 0;
                } else {
                        statflag = 1;
                }
        } else {
                debuglog("Rpc call to statd failed with return value: %d\n",
                    rpcret);
                statflag = 0;
        }

        if (statflag == 1) {
                TAILQ_INSERT_HEAD(&hostlst_head, nhp, hostlst);
        } else {
                free(nhp);
        }
}

/*
 * unmonitor_lock_host: clear monitor ref counts and inform statd when gone
 */
void
unmonitor_lock_host(const char *hostname)
{
        struct host *ihp;

        TAILQ_FOREACH(ihp, &hostlst_head, hostlst) {
                if (strncmp(hostname, ihp->name, SM_MAXSTRLEN) == 0) {
                        /* Host is unmonitored, drop refcount */
                        --ihp->refcnt;
                        /* Host should only be in the monitor list once */
                        break;
                }
        }

        if (ihp == NULL) {
                debuglog("Could not find host %16s in mon list\n", hostname);
                return;
        }

        if (ihp->refcnt > 0)
                return;

        if (ihp->refcnt < 0) {
                debuglog("Negative refcount!: %d\n", ihp->refcnt);
        }

        TAILQ_REMOVE(&hostlst_head, ihp, hostlst);
        TAILQ_INSERT_HEAD(&hostlst_unref, ihp, hostlst);
        if (host_expire <= 0)
                destroy_lock_host(ihp);
}

void
destroy_lock_host(struct host *ihp)
{
        struct mon_id smon_id;
        struct sm_stat smstat;
        int rpcret;

        debuglog("Attempting to unmonitor host %16s\n", ihp->name);

        bzero(&smon_id,sizeof(smon_id));

        smon_id.mon_name = (char *)ihp->name;
        smon_id.my_id.my_name = "localhost";
        smon_id.my_id.my_prog = NLM_PROG;
        smon_id.my_id.my_vers = NLM_SM;
        smon_id.my_id.my_proc = NLM_SM_NOTIFY;
                          
        rpcret = callrpc("localhost", SM_PROG, SM_VERS, SM_UNMON, xdr_mon_id,
            &smon_id, xdr_sm_stat, &smstat);
                          
        if (rpcret != 0) {
                debuglog("Rpc call to unmonitor statd failed with "
                   " return value: %d: %s", rpcret, clnt_sperrno(rpcret));
        } else {
                debuglog("Succeeded unmonitoring %16s\n", ihp->name);
        }

        TAILQ_REMOVE(&hostlst_unref, ihp, hostlst);
        free(ihp);
}

/*
 * returns 1 if there are hosts to expire or 0 if there are none.
 */
int
expire_lock_hosts(void)
{
        struct host *ihp;

        debuglog("expire_lock_hosts: called\n");
        for ( ;; ) {
                ihp = TAILQ_LAST(&hostlst_unref, hostlst_head);
                if (ihp == NULL)
                        break;
                if (host_expire > 0 && ihp->lastuse >= currsec - host_expire)
                        break;
                debuglog("expire_lock_hosts: expiring %s %d %d %d\n",
                    ihp->name, (int)ihp->lastuse,
                    (int)currsec, (int)currsec - host_expire);
                destroy_lock_host(ihp);
        }
        return (TAILQ_LAST(&hostlst_unref, hostlst_head) != NULL);
}

/*
 * notify: Clear all locks from a host if statd complains
 *
 * XXX: This routine has not been thoroughly tested.  However, neither
 * had the old one been.  It used to compare the statd crash state counter
 * to the current lock state.  The upshot of this was that it basically
 * cleared all locks from the specified host 99% of the time (with the
 * other 1% being a bug).  Consequently, the assumption is that clearing
 * all locks from a host when notified by statd is acceptable.
 *
 * Please note that this routine skips the usual level of redirection
 * through a do_* type routine.  This introduces a possible level of
 * error and might better be written as do_notify and take this one out.

 */

void
notify(const char *hostname, const int state)
{
        debuglog("notify from %s, new state %d", hostname, state);
        
        siglock();
        do_clear(hostname);
        sigunlock();

        debuglog("Leaving notify\n");
}

int
send_granted(fl, opcode)
        struct file_lock *fl;
        int opcode __unused;
{
        CLIENT *cli;
        static char dummy;
        struct timeval timeo;
        enum clnt_stat rv;
        static struct nlm_res retval;
        static struct nlm4_res retval4;

        debuglog("About to send granted on blocked lock\n");

        cli = get_client(fl->addr,
            (fl->flags & LOCK_V4) ? NLM_VERS4 : NLM_VERS);
        if (cli == NULL) {
                syslog(LOG_NOTICE, "failed to get CLIENT for %s",
                    fl->client_name);
                /*
                 * We fail to notify remote that the lock has been granted.
                 * The client will timeout and retry, the lock will be
                 * granted at this time.
                 */
                return -1;
        }
        timeo.tv_sec = 0;
        timeo.tv_usec = (fl->flags & LOCK_ASYNC) ? 0 : 500000; /* 0.5s */

        fl->granted_cookie = ++send_granted_cookie;
        if (!send_granted_cookie)
                send_granted_cookie++;

        if (fl->flags & LOCK_V4) {
                static nlm4_testargs res;
                res.cookie.n_len = sizeof(fl->granted_cookie);
                res.cookie.n_bytes = (char*)&fl->granted_cookie;
                res.exclusive = fl->client.exclusive;
                res.alock.caller_name = fl->client_name;
                res.alock.fh.n_len = fl->filehandle.n_len;
                res.alock.fh.n_bytes = fl->filehandle.n_bytes;
                res.alock.oh = fl->client.oh;
                res.alock.svid = fl->client.svid;
                res.alock.l_offset = fl->client.l_offset;
                res.alock.l_len = fl->client.l_len;
                debuglog("sending v4 reply%s",
                         (fl->flags & LOCK_ASYNC) ? " (async)":"");
                if (fl->flags & LOCK_ASYNC) {
                        rv = clnt_call(cli, NLM4_GRANTED_MSG,
                            xdr_nlm4_testargs, &res, xdr_void, &dummy, timeo);
                } else {
                        rv = clnt_call(cli, NLM4_GRANTED,
                            xdr_nlm4_testargs, &res, xdr_nlm4_res,
                            &retval4, timeo);
                }
        } else {
                static nlm_testargs res;

                res.cookie.n_len = sizeof(fl->granted_cookie);
                res.cookie.n_bytes = (char*)&fl->granted_cookie;
                res.exclusive = fl->client.exclusive;
                res.alock.caller_name = fl->client_name;
                res.alock.fh.n_len = fl->filehandle.n_len;
                res.alock.fh.n_bytes = fl->filehandle.n_bytes;
                res.alock.oh = fl->client.oh;
                res.alock.svid = fl->client.svid;
                res.alock.l_offset = fl->client.l_offset;
                res.alock.l_len = fl->client.l_len;
                debuglog("sending v1 reply%s",
                         (fl->flags & LOCK_ASYNC) ? " (async)":"");
                if (fl->flags & LOCK_ASYNC) {
                        rv = clnt_call(cli, NLM_GRANTED_MSG,
                            xdr_nlm_testargs, &res, xdr_void, &dummy, timeo);
                } else {
                        rv = clnt_call(cli, NLM_GRANTED,
                            xdr_nlm_testargs, &res, xdr_nlm_res,
                            &retval, timeo);
                }
        }
        if (debug_level > 2)
                debuglog("clnt_call returns %d(%s) for granted",
                         rv, clnt_sperrno(rv));

        if ((rv != RPC_SUCCESS) &&
            !((fl->flags & LOCK_ASYNC) && (rv == RPC_TIMEDOUT)))
                return -1;
        return 0;
}

/*
 * granted_failed: remove a granted lock that wasn't successfully
 * accepted by the client
 */
void
granted_failed(nlm4_res *arg)
{
        u_int64_t cookie;
        struct file_lock *ifl;

        debuglog("Entering granted_failed, status %d\n", arg->stat.stat);

        if (arg->cookie.n_len != sizeof(cookie)) {
                debuglog("Exiting granted_failed: bogus cookie size %d\n",
                        arg->cookie.n_len);
                return;
        }
        bcopy(arg->cookie.n_bytes, &cookie, sizeof(cookie));
        debuglog("granted_failed, cookie 0x%llx\n", cookie);

        LIST_FOREACH(ifl, &nfslocklist_head, nfslocklist) {
                debuglog("Pointer to file lock: %p\n",ifl);

                debuglog("****Dump of ifl****\n");
                dump_filelock(ifl);

                if (ifl->granted_cookie != cookie)
                        continue;

                debuglog("granted_failed: cookie found\n");
                break;
        }

        if (ifl) {
                do_unlock(ifl);
                /* ifl is NO LONGER VALID AT THIS POINT */
        } else {
                debuglog("granted_failed: cookie NOT FOUND\n");
        }

        debuglog("Exiting granted_failed\n");
}

/*
 * getshare: try to acquire a share reservation
 */
enum nlm4_stats
getshare(nlm_shareargs *shrarg, struct svc_req *rqstp, const int flags)
{
        struct sharefile *shrfile;
        struct file_share *sh;
        size_t n;

        debuglog("Entering getshare...\n");

        if (grace_expired == 0 && shrarg->reclaim == 0) {
                debuglog("getshare denied - grace period\n");
                return (flags & LOCK_V4) ?
                        nlm4_denied_grace_period :
                        nlm_denied_grace_period;
        }

        if (shrarg->share.fh.n_len > NFS_MAX_FH_SIZE) {
                debuglog("received fhandle size %d, max size %d",
                    shrarg->share.fh.n_len, NFS_MAX_FH_SIZE);
                return (flags & LOCK_V4) ? nlm4_failed : nlm_denied;
        }

        /* find file in list of share files */
        LIST_FOREACH(shrfile, &nfssharefilelist_head, sharefilelist) {
                if ((shrarg->share.fh.n_len == shrfile->filehandle.n_len) &&
                    (bcmp(shrarg->share.fh.n_bytes, shrfile->filehandle.n_bytes,
                        shrarg->share.fh.n_len) == 0)) {
                        /* shrfile is the correct file */
                        break;
                }
        }

        /* if share file not found, create a new share file */
        if (!shrfile) {
                fhandle_t fh;
                int fd;
                fh.fh_len = shrarg->share.fh.n_len;
                bcopy(shrarg->share.fh.n_bytes, fh.fh_data, fh.fh_len);
                fd = fhopen(&fh, O_RDONLY);
                if (fd < 0) {
                        debuglog("fhopen failed (from %16s): %32s\n",
                            shrarg->share.caller_name, strerror(errno));
                        if ((flags & LOCK_V4) == 0)
                                return nlm_denied;
                        switch (errno) {
                        case ESTALE:
                                return nlm4_stale_fh;
                        default:
                                return nlm4_failed;
                        }
                }
                shrfile = malloc(sizeof(struct sharefile));
                if (!shrfile) {
                        debuglog("getshare failed: can't allocate sharefile\n");
                        close(fd);
                        return (flags & LOCK_V4) ? nlm4_denied_nolocks : nlm_denied_nolocks;
                }
                shrfile->filehandle.n_len = shrarg->share.fh.n_len;
                shrfile->filehandle.n_bytes = malloc(shrarg->share.fh.n_len);
                if (!shrfile->filehandle.n_bytes) {
                        debuglog("getshare failed: can't allocate sharefile filehandle\n");
                        free(shrfile);
                        close(fd);
                        return (flags & LOCK_V4) ? nlm4_denied_nolocks : nlm_denied_nolocks;
                }
                bcopy(shrarg->share.fh.n_bytes, shrfile->filehandle.n_bytes,
                        shrarg->share.fh.n_len);
                shrfile->fd = fd;
                shrfile->refcount = 0;
                shrfile->sharelist_head.lh_first = NULL;
                LIST_INSERT_HEAD(&nfssharefilelist_head, shrfile, sharefilelist);
        }

        /* compare request mode/access to current shares */
        LIST_FOREACH(sh, &shrfile->sharelist_head, nfssharelist) {
                /* if request host/owner matches a current share... */
                if ((strncmp(shrarg->share.caller_name, sh->client_name, SM_MAXSTRLEN) == 0) &&
                        same_netobj(&shrarg->share.oh, &sh->oh)) {
                        /* ...then just update share mode/access */
                        sh->mode = shrarg->share.mode;
                        sh->access = shrarg->share.access;
                        debuglog("getshare: updated existing share\n");
                        return (flags & LOCK_V4) ? nlm4_granted : nlm_granted;
                }
                if (((shrarg->share.mode & sh->access) != 0) ||
                    ((shrarg->share.access & sh->mode) != 0)) {
                        /* share request conflicts with existing share */
                        debuglog("getshare: conflicts with existing share\n");
                        return (flags & LOCK_V4) ? nlm4_denied : nlm_denied;
                }
        }

        /* create/init new share */
        n = strnlen(shrarg->share.caller_name, SM_MAXSTRLEN);
        if (n < SM_MAXSTRLEN) {
                sh = malloc(sizeof(*sh) - sizeof(sh->client_name) + n + 1);
        } else {
                debuglog("getshare failed: hostname too long\n");
                sh = NULL;
        }
        if (!sh) {
                debuglog("getshare failed: can't allocate share\n");
                if (!shrfile->refcount) {
                        LIST_REMOVE(shrfile, sharefilelist);
                        close(shrfile->fd);
                        free(shrfile->filehandle.n_bytes);
                        free(shrfile);
                }
                return (flags & LOCK_V4) ? nlm4_denied_nolocks : nlm_denied_nolocks;
        }
        bzero(sh, sizeof(*sh) - sizeof(sh->client_name));
        sh->oh.n_len = shrarg->share.oh.n_len;
        sh->oh.n_bytes = malloc(sh->oh.n_len);
        if (!sh->oh.n_bytes) {
                debuglog("getshare failed: can't allocate share owner handle\n");
                free(sh);
                if (!shrfile->refcount) {
                        LIST_REMOVE(shrfile, sharefilelist);
                        close(shrfile->fd);
                        free(shrfile->filehandle.n_bytes);
                        free(shrfile);
                }
                return (flags & LOCK_V4) ? nlm4_denied_nolocks : nlm_denied_nolocks;
        }
        memcpy(sh->client_name, shrarg->share.caller_name, n);
        sh->client_name[n] = 0;
        sh->mode = shrarg->share.mode;
        sh->access = shrarg->share.access;

        /* insert new share into file's share list */
        LIST_INSERT_HEAD(&shrfile->sharelist_head, sh, nfssharelist);
        shrfile->refcount++;

        debuglog("Exiting getshare...\n");

        return (flags & LOCK_V4) ? nlm4_granted : nlm_granted;
}


/* remove a share reservation */
enum nlm4_stats
unshare(nlm_shareargs *shrarg, struct svc_req *rqstp, const int flags)
{
        struct sharefile *shrfile;
        struct file_share *sh;

        debuglog("Entering unshare...\n");

        if (shrarg->share.fh.n_len > NFS_MAX_FH_SIZE) {
                debuglog("received fhandle size %d, max size %d",
                    shrarg->share.fh.n_len, NFS_MAX_FH_SIZE);
                return (flags & LOCK_V4) ? nlm4_failed : nlm_denied;
        }

        /* find file in list of share files */
        LIST_FOREACH(shrfile, &nfssharefilelist_head, sharefilelist) {
                if ((shrarg->share.fh.n_len == shrfile->filehandle.n_len) &&
                    (bcmp(shrarg->share.fh.n_bytes, shrfile->filehandle.n_bytes,
                        shrarg->share.fh.n_len) == 0)) {
                        /* shrfile is the correct file */
                        break;
                }
        }

        /* if share file not found, return success (per spec) */
        if (!shrfile) {
                debuglog("unshare: no such share file\n");
                return (flags & LOCK_V4) ? nlm4_granted : nlm_granted;
        }

        /* find share */
        LIST_FOREACH(sh, &shrfile->sharelist_head, nfssharelist) {
                /* if request host/owner matches a current share... */
                if ((strncmp(shrarg->share.caller_name, sh->client_name, SM_MAXSTRLEN) == 0) &&
                        same_netobj(&shrarg->share.oh, &sh->oh))
                        break;
        }

        /* if share not found, return success (per spec) */
        if (!sh) {
                debuglog("unshare: no such share\n");
                return (flags & LOCK_V4) ? nlm4_granted : nlm_granted;
        }

        /* remove share from file and deallocate */
        shrfile->refcount--;
        LIST_REMOVE(sh, nfssharelist);
        free(sh->oh.n_bytes);
        free(sh);

        /* if file has no more shares, deallocate share file */
        if (!shrfile->refcount) {
                debuglog("unshare: file has no more shares\n");
                LIST_REMOVE(shrfile, sharefilelist);
                close(shrfile->fd);
                free(shrfile->filehandle.n_bytes);
                free(shrfile);
        }

        debuglog("Exiting unshare...\n");

        return (flags & LOCK_V4) ? nlm4_granted : nlm_granted;
}

/*
 * do_free_all
 *
 * Wipe out all non-monitored locks and shares held by a host.
 */

void 
do_free_all(const char *hostname)
{
        struct file_lock *ifl, *nfl;
        struct sharefile *shrfile, *nshrfile;
        struct file_share *ifs, *nfs;
        enum partialfilelock_status pfsret;

        /* clear non-monitored blocking file locks */
        ifl = LIST_FIRST(&blockedlocklist_head);
        while (ifl != NULL) {
                nfl = LIST_NEXT(ifl, nfslocklist);

                if (((ifl->flags & LOCK_MON) == 0) &&
                    (strncmp(hostname, ifl->client_name, SM_MAXSTRLEN) == 0)) {
                        remove_blockingfilelock(ifl);
                        deallocate_file_lock(ifl);
                }

                ifl = nfl;
        }

        /* clear non-monitored file locks */
restart:
        ifl = LIST_FIRST(&nfslocklist_head);
        while (ifl != NULL) {
                nfl = LIST_NEXT(ifl, nfslocklist);

                if (((ifl->flags & LOCK_MON) == 0) &&
                    (strncmp(hostname, ifl->client_name, SM_MAXSTRLEN) == 0)) {
                        /* Unlock destroys ifl out from underneath */
                        pfsret = unlock_partialfilelock(ifl);
                        if (pfsret != PFL_GRANTED) {
                                /* Uh oh... there was some sort of problem. */
                                /* If we restart the loop, we may get */
                                /* stuck here forever getting errors. */
                                /* So, let's just abort the whole scan. */
                                syslog(LOG_WARNING, "unmonitored lock clearing for %s failed: %d",
                                        hostname, pfsret);
                                break;
                        }
                        /* ifl is NO LONGER VALID AT THIS POINT */
                        /* Note: the unlock may deallocate several existing locks. */
                        /* Therefore, we need to restart the scanning of the list, */
                        /* because nfl could be pointing to a freed lock. */
                        goto restart;
                }

                ifl = nfl;
        }

        /* clear shares */
        shrfile = LIST_FIRST(&nfssharefilelist_head);
        while (shrfile != NULL) {
                nshrfile = LIST_NEXT(shrfile, sharefilelist);

                ifs = LIST_FIRST(&shrfile->sharelist_head);
                while (ifs != NULL) {
                        nfs = LIST_NEXT(ifs, nfssharelist);

                        if (strncmp(hostname, ifs->client_name, SM_MAXSTRLEN) == 0) {
                                shrfile->refcount--;
                                LIST_REMOVE(ifs, nfssharelist);
                                free(ifs->oh.n_bytes);
                                free(ifs);
                        }

                        ifs = nfs;
                }

                if (!shrfile->refcount) {
                        LIST_REMOVE(shrfile, sharefilelist);
                        close(shrfile->fd);
                        free(shrfile->filehandle.n_bytes);
                        free(shrfile);
                }

                shrfile = nshrfile;
        }

}



/*
 * Routines below here have not been modified in the overhaul
 */

/*
 * Are these two routines still required since lockd is not spawning off
 * children to service locks anymore?  Presumably they were originally
 * put in place to prevent a one child from changing the lock list out
 * from under another one.
 */

void
siglock(void)
{
  sigset_t block;
        
  sigemptyset(&block);
  sigaddset(&block, SIGCHLD);

  if (sigprocmask(SIG_BLOCK, &block, NULL) < 0) {
    syslog(LOG_WARNING, "siglock failed: %s", strerror(errno));
  }
}

void
sigunlock(void)
{
  sigset_t block;
        
  sigemptyset(&block);
  sigaddset(&block, SIGCHLD);
  
  if (sigprocmask(SIG_UNBLOCK, &block, NULL) < 0) {
    syslog(LOG_WARNING, "sigunlock failed: %s", strerror(errno));
  }
}