cmd/format/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 * Copyrighted as an unpublished work.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 <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"
#include "global.h"
#include "ctlr_ata.h"
#include "misc.h"

#define	FAILURE	1
#define	SUCCESS	0

#define	CMD_READ	0
#define	CMD_WRITE	1

struct	badsec_lst *badsl_chain = NULL;
int	badsl_chain_cnt = 0;
struct	badsec_lst *gbadsl_chain = NULL;
int	gbadsl_chain_cnt = 0;

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

/* prototypes */
int updatebadsec(struct  dkl_partition *, int);
int read_altsctr(struct  dkl_partition *);
static int chk_badsec(void);
static int init_altsctr(void);
static int get_altsctr(void);
int wr_altsctr(void);
static void get_badsec(void);
static int count_badsec(void);
static int gen_alts_ent(void);
static int assign_altsctr(void);
static void expand_map(void);
static void compress_map(void);
static int altsmap_getbit(blkaddr_t);
static blkaddr_t altsmap_alloc(blkaddr_t, blkaddr_t, int, int);
static void ent_sort(struct  alts_ent *, int);
static void ent_compress(struct  alts_ent *, int);
static int ent_merge(struct alts_ent *, struct alts_ent *, int,
		struct alts_ent *, int);
static int ent_bsearch(struct  alts_ent *, int, struct  alts_ent *);
static int chk_bad_altsctr(blkaddr_t);

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

/*
 * read_altsctr( ptr to alternate sector partition )
 *		-- read the alternate sector partition tables
 */
int
read_altsctr(struct dkl_partition *part)
{
	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 = malloc(ap->ap_tbl_secsiz);
		if (ap->ap_tblp == NULL) {
			(void) fprintf(stderr,
			    "Unable to malloc alternate partition table.\n");
			return (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 = malloc(part->p_size)) == NULL) {
			(void) fprintf(stderr, "Unable to malloc incore "
			    "alternate partition map.\n");
			return (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 = malloc(ap->ap_map_secsiz)) == NULL) {
			(void) fprintf(stderr, "Unable to malloc alternate "
			    "partition map.\n");
			return (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");
			(void) init_altsctr();
		} else {
			if (get_altsctr() == SUCCESS)
				(void) chk_badsec();
			else
				(void) init_altsctr();
		}
	}
	return (SUCCESS);
}


/*
 *	checking duplicate bad sectors or bad sectors in ALTSCTR partition
 */
static int
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");
					return (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");
					return (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");
					return (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;
			}
		}
	}
	return (SUCCESS);
}

/*
 *	initialize the alternate partition tables
 */
static int
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");
				return (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: ");
		return (57);
	}
	(void) wr_altsctr();

	return (SUCCESS);
}


/*
 *	read the alternate partition tables from disk
 */
static int
get_altsctr(void)
{
	int	mystatus = FAILURE;
	int	status = 0;

	/* get alts partition table info */

	status = ata_rdwr(DIR_READ, cur_file, altsec_offset,
	    ap->ap_tbl_secsiz / UBSIZE, (char *)ap->ap_tblp, 0, NULL);
	if (status == FAILURE) {
		perror("Unable to read alternate sector partition: ");
		return (58);
	}
	if (ap->ap_tblp->alts_sanity != ALTS_SANITY)
		return (mystatus);

	/* get the alts map */
	status = ata_rdwr(DIR_READ, cur_file,
	    (ap->ap_tblp->alts_map_base) + altsec_offset,
	    ap->ap_map_secsiz / UBSIZE, (char *)ap->ap_mapp, 0, NULL);
	if (status == FAILURE) {
		perror("Unable to read alternate sector partition map: ");
		return (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);
		ap->ap_entp = malloc(ap->ap_ent_secsiz);
		if (ap->ap_entp == NULL) {
			(void) fprintf(stderr,
			    "Unable to malloc alternate sector entry table.\n");
			return (60);
		}

		status = ata_rdwr(DIR_READ, cur_file,
		    (ap->ap_tblp->alts_ent_base) + altsec_offset,
		    ap->ap_ent_secsiz / UBSIZE, (char *)ap->ap_entp,
		    0, NULL);
		if (status == FAILURE) {
			perror("Unable to read alternate sector entry table: ");
			return (61);
		}
	}

	return (SUCCESS);
}


/*
 *	update the new alternate partition tables on disk
 */
int
wr_altsctr(void)
{
	int	status;

	if (ap->ap_tblp == NULL)
		return (0);
	status = ata_rdwr(DIR_WRITE, cur_file, altsec_offset,
	    ap->ap_tbl_secsiz / UBSIZE, (char *)ap->ap_tblp, 0, NULL);
	if (status) {
		(void) printf("ata_rdwr status = %d need = %d\n",
		    status, ap->ap_tbl_secsiz / 512);
		perror("Unable to write with ata_rdwr the alt sector part: ");
		return (62);
	}

	if (ata_rdwr(DIR_WRITE, cur_file, (ap->ap_tblp->alts_map_base) +
	    altsec_offset, ap->ap_map_secsiz / UBSIZE,
	    (char *)ap->ap_mapp, 0, NULL) == FAILURE) {
		perror("Unable to write alternate sector partition map: ");
		return (63);
	}

	if (ap->ap_tblp->alts_ent_used != 0) {
		if (ata_rdwr(DIR_WRITE, cur_file,
		    (ap->ap_tblp->alts_ent_base)+ altsec_offset,
		    ap->ap_ent_secsiz / UBSIZE,
		    (char *)ap->ap_entp, 0, NULL) == FAILURE) {
			perror("Unable to write alternate sector "
			    "entry table: ");
			return (64);
		}
	}
	return (0);
}


/*
 *	get a list of bad sector
 */
static void
get_badsec(void)
{
	int	cnt;
	struct	badsec_lst *blc_p;
	blkaddr_t	curbad;
	blkaddr_t	maxsec = cur_dtype->dtype_nhead *
	    cur_dtype->dtype_ncyl * cur_dtype->dtype_nsect;
	struct	alts_ent *growbadp;
	int	i;

	cnt = count_badsec();
	if (cnt == 0) {
		ap->ap_gbadp = NULL;
		ap->ap_gbadcnt = 0;
	} else {
		ap->ap_gbadp = malloc(cnt * ALTS_ENT_SIZE);
		if (ap->ap_gbadp == NULL) {
			err_print("get_badsec: unable to malloc %d bytes\n",
			    cnt * ALTS_ENT_SIZE);
			fullabort();
		}
		(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)cur_dtype->dtype_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 int
gen_alts_ent(void)
{
	uint_t	ent_used;
	struct	alts_ent *entp;

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

	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 = malloc(ap->ap_ent_secsiz);
	if (entp == NULL) {
		err_print("get_alts_ent: unable to malloc %d bytes\n",
		    ap->ap_ent_secsiz);
		fullabort();
	}

	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 */
	(void) assign_altsctr();

	/* allocate the alts_entry on disk skipping possible bad sectors */
	ap->ap_tblp->alts_ent_base =
	    altsmap_alloc((blkaddr_t)ap->ap_tblp->alts_map_base +
	    ap->ap_map_sectot, (blkaddr_t)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: ");
		return (65);
	}

	ap->ap_tblp->alts_ent_end = ap->ap_tblp->alts_ent_base +
	    (ap->ap_ent_secsiz / NBPSCTR) - 1;
	return (0);
}


/*
 *	assign alternate sectors for bad sector mapping
 */
static int
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);
			return (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;
		}
	}
	return (SUCCESS);
}

/*
 *	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; ) {
		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;
/*
 *	daddr_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);
			return (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);

}