sd: remove 'ssd' driver support

[unleashed/tickless.git] / usr / src / cmd / addbadsec / ix_altsctr.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 * copyright (c) 1990, 1991 UNIX System Laboratories, Inc.
 * copyright (c) 1984, 1986, 1987, 1988, 1989, 1990 AT&T
 * All rights reserved.
 */

/*
 * Copyrighted as an unpublished work.
 * (c) Copyright INTERACTIVE Systems Corporation 1986, 1988, 1990
 * All rights reserved.
 */

#include <sys/types.h>
#include <ctype.h>
#include <fcntl.h>
#include <malloc.h>
#include <sys/stat.h>
#include <sys/swap.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/vtoc.h>
#include <sys/param.h>
#include <sys/dkio.h>
#include <sys/dktp/altsctr.h>
#include <sys/dktp/fdisk.h>
#include "badsec.h"

#define FAILURE 0
#define SUCCESS 1

#define CMD_READ        0
#define CMD_WRITE       1

struct  badsec_lst *badsl_chain;
int     badsl_chain_cnt;
struct  badsec_lst *gbadsl_chain;
int     gbadsl_chain_cnt;

extern struct dk_geom   dkg;
extern int      alts_fd;

struct  alts_mempart alts_part = { 0, NULL, 0 };
struct  alts_mempart *ap = &alts_part;  /* pointer to incore alts tables */

static void read_altsctr(struct extpartition *part, int badok);
static void chk_badsec(void);
static void init_altsctr(void);
void wr_altsctr(void);
static void get_badsec(void);
static int count_badsec(void);
static void gen_alts_ent(void);
static void assign_altsctr(void);
static void expand_map(void);
static void compress_map(void);
static int altsmap_getbit(blkaddr_t badsec);
static blkaddr_t altsmap_alloc(blkaddr_t srt_ind, blkaddr_t end_ind,
        int cnt, int dir);
static void ent_sort(struct alts_ent buf[], int cnt);
static void ent_compress(struct alts_ent buf[], int cnt);
static int  ent_merge(
        struct alts_ent buf[],
        struct alts_ent list1[],
        int    lcnt1,
        struct alts_ent list2[],
        int    lcnt2);
static int  ent_bsearch(struct alts_ent buf[], int cnt, struct alts_ent *key);
static int  chk_bad_altsctr(blkaddr_t badsec);
int     print_altsec(struct extpartition *part);
int     get_altsctr(int);
static void print_altsctr(void);
static int  absdsk_io(int fd, uint_t srtsec, char *bufp, uint_t len,
        int ioflag);

/*
 * updatebadsec () -- update bad sector/track mapping tables
 */
int
updatebadsec(struct extpartition *part, int init_flag)
{
        if (init_flag)
                ap->ap_flag |= ALTS_ADDPART;
        get_badsec();
        read_altsctr(part, 1);
        ent_sort(ap->ap_gbadp, ap->ap_gbadcnt);
        ent_compress(ap->ap_gbadp, ap->ap_gbadcnt);
        gen_alts_ent();
        compress_map();
        return (SUCCESS);
}

/*
 * read_altsctr( ptr to alternate sector partition )
 *              -- read the alternate sector partition tables
 */
static void
read_altsctr(struct extpartition *part, int badok)
{
        if (ap->ap_tblp == NULL) {
/*          allocate buffer for the alts partition table (sector size)  */
            ap->ap_tbl_secsiz = byte_to_secsiz(ALTS_PARTTBL_SIZE, NBPSCTR);
            ap->ap_tblp = (struct alts_parttbl *)malloc(ap->ap_tbl_secsiz);
            if (ap->ap_tblp == NULL) {
                (void) fprintf(stderr,
                        "Unable to malloc alternate partition table.\n");
                exit(50);
            }

/*          allocate buffer for the alts partition map (sector size)    */
/*          buffers include the disk image bit map                      */
/*          and the incore transformed char map                         */

            if ((ap->ap_memmapp = (uchar_t *)malloc(part->p_size)) == NULL) {
                (void) fprintf(stderr,
                        "Unable to malloc incore alternate partition map.\n");
                exit(51);
            }
            ap->ap_tblp->alts_map_len = (part->p_size + 8 - 1) / 8;
            ap->ap_map_secsiz = byte_to_secsiz(ap->ap_tblp->alts_map_len,
                NBPSCTR);
            ap->ap_map_sectot = ap->ap_map_secsiz / NBPSCTR;
            if ((ap->ap_mapp = (uchar_t *)malloc(ap->ap_map_secsiz)) == NULL) {
                (void) fprintf(stderr,
                    "Unable to malloc alternate partition map.\n");
                exit(52);
            }
/*          clear the buffers to zero                                   */
            (void) memset(ap->ap_memmapp, 0, part->p_size);
            (void) memset(ap->ap_mapp, 0, ap->ap_map_secsiz);
            ap->part = *part;           /* struct copy                  */

/*
 *          if add alternate partition flag is set, then install the partition
 *          otherwise read the alts partition info from disk
 *          if failed, then assume the first installation
 */
            if (ap->ap_flag & ALTS_ADDPART) {
                (void) fprintf(stderr,
                    "WARNING: Manually initializing alternate table.\n");
                init_altsctr();
            } else {
                if (get_altsctr(badok) == SUCCESS)
                    chk_badsec();
                else
                    init_altsctr();
            }
        }
}


/*
 *      checking duplicate bad sectors or bad sectors in ALTSCTR partition
 */
static void
chk_badsec(void)
{
        blkaddr_t       badsec;
        blkaddr_t       altsp_srtsec = ap->part.p_start;
        blkaddr_t       altsp_endsec = ap->part.p_start + ap->part.p_size - 1;
        int     cnt;
        int     status;

        for (cnt = 0; cnt < ap->ap_gbadcnt; cnt++) {
            badsec = (ap->ap_gbadp)[cnt].bad_start;

            /* if bad sector is within the ATLSCTR partition */
            if ((badsec >= altsp_srtsec) && (badsec <= altsp_endsec)) {
                if ((ap->ap_memmapp)[badsec - altsp_srtsec] != ALTS_BAD) {
                    if ((badsec >= altsp_srtsec) && (badsec <= (altsp_srtsec +
                        ap->ap_tbl_secsiz / NBPSCTR - 1))) {
                        (void) fprintf(stderr,
                            "Alternate partition information table is bad.\n");
                        exit(53);
                    }
                    if ((badsec >= altsp_srtsec+ap->ap_tblp->alts_map_base) &&
                        (badsec <= (altsp_srtsec + ap->ap_tblp->alts_map_base +
                        ap->ap_map_sectot - 1))) {
                        (void) fprintf(stderr,
                            "Alternate partition map is bad.\n");
                        exit(54);
                    }
                    if ((badsec >= altsp_srtsec+ap->ap_tblp->alts_ent_base) &&
                        (badsec <= (altsp_srtsec + ap->ap_tblp->alts_ent_base +
                        ap->ap_ent_secsiz / NBPSCTR - 1))) {
                        (void) fprintf(stderr,
                            "Alternate partition entry table is bad.\n");
                        exit(55);
                    }
                    (ap->ap_memmapp)[badsec - altsp_srtsec] = ALTS_BAD;
                    (ap->ap_gbadp)[cnt].bad_start = (uint32_t)ALTS_ENT_EMPTY;
                } else {
                    status = chk_bad_altsctr(badsec);
                    (ap->ap_gbadp)[cnt].bad_start = (uint32_t)ALTS_ENT_EMPTY;
                }
            } else {
/*
 *              binary search for bad sector in the alts entry table
 */
                status = ent_bsearch(ap->ap_entp, ap->ap_tblp->alts_ent_used,
                                        &((ap->ap_gbadp)[cnt]));
/*
 *              if the bad sector had already been remapped(found in alts_entry)
 *              then ignore the bad sector
 */
                if (status != -1) {
                    (ap->ap_gbadp)[cnt].bad_start = (uint32_t)ALTS_ENT_EMPTY;
                }
            }
        }
        
}

/*
 *      initialize the alternate partition tables
 */
static void
init_altsctr(void)
{
        blkaddr_t       badsec;
        blkaddr_t       altsp_srtsec = ap->part.p_start;
        blkaddr_t       altsp_endsec = ap->part.p_start + ap->part.p_size - 1;
        int     cnt;

        ap->ap_entp = NULL;
        ap->ap_ent_secsiz = 0;
        ap->ap_tblp->alts_sanity = ALTS_SANITY;
        ap->ap_tblp->alts_version = ALTS_VERSION1;
        ap->ap_tblp->alts_map_len = (ap->part.p_size + 8 - 1) / 8;
        ap->ap_tblp->alts_ent_used = 0;
        ap->ap_tblp->alts_ent_base = 0;
        ap->ap_tblp->alts_ent_end  = 0;
        ap->ap_tblp->alts_resv_base = ap->part.p_size - 1;
        for (cnt = 0; cnt < 5; cnt++)
            ap->ap_tblp->alts_pad[cnt] = 0;

        for (cnt = 0; cnt < ap->ap_gbadcnt; cnt++) {
            badsec = (ap->ap_gbadp)[cnt].bad_start;
            if ((badsec >= altsp_srtsec) && (badsec <= altsp_endsec)) {
                if (badsec == altsp_srtsec) {
                    (void) fprintf(stderr,
                        "First sector of alternate partition is bad.\n");
                    exit(56);
                }
                (ap->ap_memmapp)[badsec - altsp_srtsec] = ALTS_BAD;
                (ap->ap_gbadp)[cnt].bad_start = (uint32_t)ALTS_ENT_EMPTY;
            }
        }

/*      allocate the alts_map on disk skipping possible bad sectors     */
        ap->ap_tblp->alts_map_base =
                altsmap_alloc(ap->ap_tbl_secsiz / NBPSCTR,
                        ap->part.p_size, ap->ap_map_sectot, ALTS_MAP_UP);
        if (ap->ap_tblp->alts_map_base == 0) {
            perror("Unable to allocate alternate map on disk: ");
            exit(57);
        }

}


/*
 *      read the alternate partition tables from disk
 */
int
get_altsctr(badok)
int badok;
{
/*      get alts partition table info                                   */
        if (absdsk_io(alts_fd, 0, (char *)ap->ap_tblp,
                        ap->ap_tbl_secsiz, CMD_READ) == FAILURE) {
            if (badok)
                return(FAILURE);
            perror("Unable to read alternate sector partition: ");
            exit(58);
        }
        if (ap->ap_tblp->alts_sanity != ALTS_SANITY) {
            if (badok)
                return(FAILURE);
            (void) fprintf(stderr, "Bad alternate sector magic number.\n");
            exit(69);
        }

/*      get the alts map                                                */
        if (absdsk_io(alts_fd, ap->ap_tblp->alts_map_base,
                (char *)ap->ap_mapp, ap->ap_map_secsiz, CMD_READ) == FAILURE) {
            if (badok)
                return(FAILURE);
            perror("Unable to read alternate sector partition map: ");
            exit(59);
        }

/*      transform the disk image bit-map to incore char map             */
        expand_map();

        if (ap->ap_tblp->alts_ent_used == 0) {
            ap->ap_entp = NULL;
            ap->ap_ent_secsiz = 0;
        } else {
            ap->ap_ent_secsiz = byte_to_secsiz(
                        (ap->ap_tblp->alts_ent_used*ALTS_ENT_SIZE),NBPSCTR);
            if ((ap->ap_entp =
                (struct alts_ent *)malloc(ap->ap_ent_secsiz)) == NULL) {
                if (badok)
                    return(FAILURE);
                (void) fprintf(stderr,
                    "Unable to malloc alternate sector entry table.\n");
                exit(60);
            }

            if (absdsk_io(alts_fd, ap->ap_tblp->alts_ent_base,
                (char *)ap->ap_entp, ap->ap_ent_secsiz,
                CMD_READ) ==FAILURE){
                if (badok)
                    return(FAILURE);
                perror("Unable to read alternate sector entry table: ");
                exit(61);
            }
        }
        return(SUCCESS);
}


/*
 *      update the new alternate partition tables on disk
 */
void
wr_altsctr(void)
{
        if (ap->ap_tblp == NULL)
                return;
        if (absdsk_io(alts_fd, 0, (char *)ap->ap_tblp,
                ap->ap_tbl_secsiz, CMD_WRITE) == FAILURE) {
            perror("Unable to write alternate sector partition: ");
            exit(62);
        }

        if (absdsk_io(alts_fd, ap->ap_tblp->alts_map_base,
                (char *)ap->ap_mapp, ap->ap_map_secsiz, CMD_WRITE) == FAILURE) {
            perror("Unable to write alternate sector partition map: ");
            exit(63);
        }

        if (ap->ap_tblp->alts_ent_used != 0) {
            if (absdsk_io(alts_fd, ap->ap_tblp->alts_ent_base,
                                (char *)ap->ap_entp, ap->ap_ent_secsiz,
                                CMD_WRITE) == FAILURE) {
                perror("Unable to write alternate sector entry table: ");
                exit(64);
            }
        }
}


/*
 *      get a list of bad sector
 */
static void
get_badsec(void)
{
        int     cnt;
        struct  badsec_lst *blc_p;
        blkaddr_t       curbad;
        blkaddr_t       maxsec = (blkaddr_t)dkg.dkg_nhead *
                                        dkg.dkg_ncyl * dkg.dkg_nsect;
        struct  alts_ent *growbadp;
        int     i;

        cnt = count_badsec();
        if (!cnt) {
            ap->ap_gbadp = NULL;
            ap->ap_gbadcnt = 0;
        } else {
            ap->ap_gbadp = (struct alts_ent *)malloc(cnt*ALTS_ENT_SIZE);
            (void) memset(ap->ap_gbadp,0,cnt*ALTS_ENT_SIZE);

            for (growbadp = ap->ap_gbadp, cnt=0, blc_p=badsl_chain;
                blc_p; blc_p=blc_p->bl_nxt) {
                for (i=0; i<blc_p->bl_cnt; i++) {
                    curbad = blc_p->bl_sec[i];
                    if (curbad < (blkaddr_t)dkg.dkg_nsect) {
                        (void) fprintf(stderr,
                            "Ignoring bad sector %ld which is in first"
                            " track of the drive.\n", curbad);
                        continue;
                    }
                    if (curbad >= maxsec) {
                        (void) fprintf(stderr,
                            "Ignoring bad sector %ld which is past"
                            " the end of the drive.\n", curbad);
                        continue;
                    }
                    growbadp[cnt].bad_start = curbad;
                    growbadp[cnt].bad_end = curbad;
                    cnt++;
                }
            }
        }
        ap->ap_gbadcnt = cnt;
}

/*
 *      count number of bad sector on list
 *      merging the bad sector list from surface analysis and the
 *      one given through the command line
 */
static int
count_badsec(void)
{

        struct badsec_lst *blc_p;

        if (!badsl_chain)
                badsl_chain = gbadsl_chain;
        else {
                for (blc_p = badsl_chain; blc_p->bl_nxt; blc_p = blc_p->bl_nxt)
                        ;
                blc_p->bl_nxt = gbadsl_chain;
        }

        badsl_chain_cnt += gbadsl_chain_cnt;
        return(badsl_chain_cnt);
}


/*
 *      generate alternate entry table by merging the existing and
 *      the new entry list.
 */
static void
gen_alts_ent(void)
{
        uint_t  ent_used;
        struct  alts_ent *entp;

        if (ap->ap_gbadcnt == 0)
            return;

        ent_used = ap->ap_tblp->alts_ent_used + ap->ap_gbadcnt;
        ap->ap_ent_secsiz = byte_to_secsiz(ent_used*ALTS_ENT_SIZE,NBPSCTR);
        entp=(struct alts_ent *) malloc (ap->ap_ent_secsiz);
        ent_used = ent_merge(entp, ap->ap_entp, ap->ap_tblp->alts_ent_used,
                             ap->ap_gbadp, ap->ap_gbadcnt);
        free(ap->ap_entp);
        free(ap->ap_gbadp);
        ap->ap_entp = entp;
        ap->ap_ent_secsiz = byte_to_secsiz(ent_used*ALTS_ENT_SIZE, NBPSCTR);
        ap->ap_tblp->alts_ent_used = ent_used;
        ap->ap_gbadp = NULL;
        ap->ap_gbadcnt = 0;

/*      assign alternate sectors to the bad sectors                     */
        assign_altsctr();

/*      allocate the alts_entry on disk skipping possible bad sectors   */
        ap->ap_tblp->alts_ent_base =
                altsmap_alloc(ap->ap_tblp->alts_map_base + ap->ap_map_sectot,
                        ap->part.p_size,
                        ap->ap_ent_secsiz / NBPSCTR, ALTS_MAP_UP);
        if (ap->ap_tblp->alts_ent_base == 0) {
            perror("Unable to allocate alternate entry table on disk: ");
            exit(65);
        }

        ap->ap_tblp->alts_ent_end = ap->ap_tblp->alts_ent_base +
                        (ap->ap_ent_secsiz / NBPSCTR) - 1;
}


/*
 *      assign alternate sectors for bad sector mapping
 */
static void
assign_altsctr(void)
{
        uint_t  i;
        uint_t  j;
        blkaddr_t       alts_ind;
        uint_t  cluster;

        for (i = 0; i < ap->ap_tblp->alts_ent_used; i++) {
            if ((ap->ap_entp)[i].bad_start == (uint32_t)ALTS_ENT_EMPTY)
                continue;
            if ((ap->ap_entp)[i].good_start != 0)
                continue;
            cluster = (ap->ap_entp)[i].bad_end-(ap->ap_entp)[i].bad_start +1;
            alts_ind =
                altsmap_alloc(ap->part.p_size-1, ap->ap_tblp->alts_map_base +
                        ap->ap_map_sectot - 1, cluster, ALTS_MAP_DOWN);
            if (alts_ind == 0) {
                (void) fprintf(stderr,
                    "Unable to allocate alternates for bad starting"
                    " sector %u.\n", (ap->ap_entp)[i].bad_start);
                exit(65);
            }
            alts_ind = alts_ind - cluster + 1;
            (ap->ap_entp)[i].good_start = alts_ind + ap->part.p_start;
            for (j = 0; j < cluster; j++) {
                (ap->ap_memmapp)[alts_ind+j] = ALTS_BAD;                
            }

        }

}

/*
 *      transform the disk image alts bit map to incore char map
 */
static void
expand_map(void)
{
        int     i;

        for (i = 0; i < ap->part.p_size; i++) {
            (ap->ap_memmapp)[i] = altsmap_getbit(i);
        }
}

/*
 *      transform the incore alts char map to the disk image bit map
 */
static void
compress_map(void)
{

        int     i;
        int     bytesz;
        char    mask = 0;
        int     maplen = 0;

        for (i = 0, bytesz = 7; i < ap->part.p_size; i++) {
            mask |= ((ap->ap_memmapp)[i] << bytesz--);
            if (bytesz < 0) {
                (ap->ap_mapp)[maplen++] = mask;
                bytesz = 7;
                mask = 0;
            }
        }
/*
 *      if partition size != multiple number of bytes
 *      then record the last partial byte
 */
        if (bytesz != 7)
            (ap->ap_mapp)[maplen] = mask;

}

/*
 *      given a bad sector number, search in the alts bit map
 *      and identify the sector as good or bad
 */
static int
altsmap_getbit(blkaddr_t badsec)
{
        uint_t  slot = badsec / 8;
        uint_t  field = badsec % 8;
        uchar_t mask;

        mask = ALTS_BAD<<7;
        mask >>= field;
        if ((ap->ap_mapp)[slot] & mask)
             return(ALTS_BAD);
        return(ALTS_GOOD);
}


/*
 *      allocate a range of sectors from the alternate partition
 */
static blkaddr_t
altsmap_alloc(blkaddr_t srt_ind, blkaddr_t end_ind, int cnt, int dir)
{
        blkaddr_t       i;
        blkaddr_t       total;
        blkaddr_t       first_ind;

        for (i = srt_ind, first_ind = srt_ind, total = 0;
            i != end_ind; i += dir) {
            if ((ap->ap_memmapp)[i] == ALTS_BAD) {
                total = 0;
                first_ind = i + dir;
                continue;
            }
            total++;
            if (total == cnt)
                return(first_ind);

        }
        return(0);
}



/*
 *      bubble sort the entry table into ascending order
 */
static void
ent_sort(struct alts_ent buf[], int cnt)
{
struct  alts_ent temp;
int     flag;
int     i, j;

        for (i = 0; i < cnt-1; i++) {
            temp = buf[cnt-1];
            flag = 1;

            for (j = cnt-1; j > i; j--) {
                if (buf[j-1].bad_start < temp.bad_start) {
                    buf[j] = temp;
                    temp = buf[j-1];
                } else {
                    buf[j] = buf[j-1];
                    flag = 0;
                }
            }
            buf[i] = temp;
            if (flag) break;
        }

}


/*
 *      compress all the contiguous bad sectors into a single entry
 *      in the entry table. The entry table must be sorted into ascending
 *      before the compression.
 */
static void
ent_compress(struct alts_ent buf[], int cnt)
{
int     keyp;
int     movp;
int     i;

        for (i = 0; i < cnt; i++) {
            if (buf[i].bad_start == (uint32_t)ALTS_ENT_EMPTY)
                continue;
            for (keyp = i, movp = i+1; movp < cnt; movp++) {
                if (buf[movp].bad_start == (uint32_t)ALTS_ENT_EMPTY)
                        continue;
                if (buf[keyp].bad_end+1 != buf[movp].bad_start)
                    break;
                buf[keyp].bad_end++;
                buf[movp].bad_start = (uint32_t)ALTS_ENT_EMPTY;
            }
            if (movp == cnt) break;
        }
}


/*
 *      merging two entry tables into a single table. In addition,
 *      all empty slots in the entry table will be removed.
 */
static int
ent_merge(
        struct alts_ent buf[],
        struct alts_ent list1[],
        int    lcnt1,
        struct alts_ent list2[],
        int    lcnt2)
{
        int     i;
        int     j1, j2;

        for (i = 0, j1 = 0, j2 = 0; j1 < lcnt1 && j2 < lcnt2; ) {
            if (list1[j1].bad_start == (uint32_t)ALTS_ENT_EMPTY) {
                j1++;
                continue;
            }
            if (list2[j2].bad_start == (uint32_t)ALTS_ENT_EMPTY) {
                j2++;
                continue;
            }
            if (list1[j1].bad_start < list2[j2].bad_start)
                buf[i++] = list1[j1++];
            else
                buf[i++] = list2[j2++];
        }
        for (; j1 < lcnt1; j1++) {
            if (list1[j1].bad_start == (uint32_t)ALTS_ENT_EMPTY)
                continue;
            buf[i++] = list1[j1];
        }
        for (; j2 < lcnt2; j2++) {
            if (list2[j2].bad_start == (uint32_t)ALTS_ENT_EMPTY)
                continue;
            buf[i++] = list2[j2];
        }
        return (i);
}


/*
 *      binary search for bad sector in the alternate entry table
 */
static int
ent_bsearch(struct alts_ent buf[], int cnt, struct alts_ent *key)
{
        int     i;
        int     ind;
        int     interval;
        int     mystatus = -1;

        if (!cnt)
                return(mystatus);

        for (i = 1; i <= cnt; i <<= 1)
            ind = i;

        for (interval = ind; interval; ) {
/*
            printf("ind= %d, intv= %d; ",ind, interval);
*/
            if ((key->bad_start >= buf[ind-1].bad_start) &&
                (key->bad_start <= buf[ind-1].bad_end)) {
                return(mystatus = ind-1);
            } else {
                interval >>= 1;
                if (!interval) break;
                if (key->bad_start < buf[ind-1].bad_start) {
                    ind = ind - interval;
                } else {
 /*                 if key is larger than the last element then break   */
                    if (ind == cnt) break;      
                    if ((ind+interval) <= cnt)
                        ind += interval;
                }
            }
        }
        return(mystatus);
}

/*
 *      check for bad sector in assigned alternate sectors
 */
static int
chk_bad_altsctr(blkaddr_t badsec)
{
        int     i;
        blkaddr_t       numsec;
        int     cnt = ap->ap_tblp->alts_ent_used;
/*
 *      blkaddr_t intv[3];
 */

        for (i = 0; i < cnt; i++) {
            numsec = (ap->ap_entp)[i].bad_end - (ap->ap_entp)[i].bad_start;
            if ((badsec >= (ap->ap_entp)[i].good_start) &&
                (badsec <= ((ap->ap_entp)[i].good_start + numsec))) {
                (void) fprintf(stderr, "Bad sector %ld is an assigned"
                    " alternate sector.\n", badsec);
                exit(66);
/*
 *              if (!numsec) {
 *                  (ap->ap_entp)[i].good_start = 0;
 *                  return (FAILURE);
 *              }
 *              intv[0] = badsec - (ap->ap_entp)[i].good_start;
 *              intv[1] = 1;
 *              intv[2] = (ap->ap_entp)[i].good_start + numsec - badsec;
 */
            }
        }
        /* the bad sector has already been identified as bad */
        return(SUCCESS);
}


/*
 * print_altsec () -- print alternate sector information
 */
int
print_altsec(struct extpartition *part)
{
        ap->ap_tblp = NULL;
        ap->ap_flag &= ~ALTS_ADDPART;
        read_altsctr(part, 0);
        print_altsctr();
        return(SUCCESS);
}

static void
print_altsctr(void)
{
        int     i;
        int     totalloc;
        int     avail;

/*      find # of available alternate sectors                           */
        for (i=0, totalloc=0; i<ap->part.p_size; i++) {
            if ((ap->ap_memmapp)[i])
                totalloc++;
        }
/*
 *      available = size of partition - allocated sectors/bad sectors
 *                  - partition table - partition map
 *                  - entry table
 */
        avail = ap->part.p_size - totalloc;
        avail = avail - (ap->ap_tbl_secsiz/NBPSCTR)
                - ap->ap_map_sectot;
        avail = avail-(ap->ap_tblp->alts_ent_end -ap->ap_tblp->alts_ent_base+1);
        if (avail < 0) avail = 0;

        (void) printf("\nALTERNATE SECTOR/TRACK MAPPING TABLE:\n");
        (void) printf("\nBad Sector Start\tAlternate Sector Start\t\tCount\n");

        for (i=0; i<ap->ap_tblp->alts_ent_used; i++) {
             (void) printf("\t%u\t     ->\t\t%u\t\t\t   %u\n",
                (ap->ap_entp)[i].bad_start,
                (ap->ap_entp)[i].good_start,
                ((ap->ap_entp)[i].bad_end - (ap->ap_entp)[i].bad_start + 1));
        }
        (void) printf("\n      %d alternate sector(s) left for allocation.\n",
            avail);

}

static int
absdsk_io(int fd, uint_t srtsec, char *bufp, uint_t len, int ioflag)
{
        int     rc;

        if (llseek (fd, (offset_t)srtsec * NBPSCTR, SEEK_SET) == -1)
                return(FAILURE);
        switch (ioflag)
        {
        case CMD_READ:
                rc = read (fd, bufp, len);
                break;
        case CMD_WRITE:
                rc = write (fd, bufp, len);
                break;
        default:
                break;
        }
        if (rc == -1)
                return(FAILURE);
        return(SUCCESS);
}