/*      $NetBSD: subr_disk.c,v 1.138 2025/04/13 14:00:59 jakllsch Exp $ */

/*-
* Copyright (c) 1996, 1997, 1999, 2000, 2009 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
* NASA Ames Research Center.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/

/*
* Copyright (c) 1982, 1986, 1988, 1993
*      The Regents of the University of California.  All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* 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. 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.
*
*      @(#)ufs_disksubr.c      8.5 (Berkeley) 1/21/94
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: subr_disk.c,v 1.138 2025/04/13 14:00:59 jakllsch Exp $");

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/kmem.h>
#include <sys/buf.h>
#include <sys/fcntl.h>
#include <sys/syslog.h>
#include <sys/disklabel.h>
#include <sys/disk.h>
#include <sys/sysctl.h>
#include <lib/libkern/libkern.h>

/*
* Disk error is the preface to plaintive error messages
* about failing disk transfers.  It prints messages of the form

hp0g: hard error reading fsbn 12345 of 12344-12347 (hp0 bn %d cn %d tn %d sn %d)

* if the offset of the error in the transfer and a disk label
* are both available.  blkdone should be -1 if the position of the error
* is unknown; the disklabel pointer may be null from drivers that have not
* been converted to use them.  The message is printed with printf
* if pri is LOG_PRINTF, otherwise it uses log at the specified priority.
* The message should be completed (with at least a newline) with printf
* or addlog, respectively.  There is no trailing space.
*/
#ifndef PRIdaddr
#define PRIdaddr PRId64
#endif
void
diskerr(const struct buf *bp, const char *dname, const char *what, int pri,
   int blkdone, const struct disklabel *lp)
{
       int unit = DISKUNIT(bp->b_dev), part = DISKPART(bp->b_dev);
       void (*pr)(const char *, ...) __printflike(1, 2);
       char partname = 'a' + part;
       daddr_t sn;

       if (/*CONSTCOND*/0)
               /* Compiler will error this if the format is wrong... */
               printf("%" PRIdaddr, bp->b_blkno);

       if (pri != LOG_PRINTF) {
               static const char fmt[] = "";
               log(pri, fmt);
               pr = addlog;
       } else
               pr = printf;
       (*pr)("%s%d%c: %s %sing fsbn ", dname, unit, partname, what,
           bp->b_flags & B_READ ? "read" : "writ");
       sn = bp->b_blkno;
       if (bp->b_bcount <= DEV_BSIZE)
               (*pr)("%" PRIdaddr, sn);
       else {
               if (blkdone >= 0) {
                       sn += blkdone;
                       (*pr)("%" PRIdaddr " of ", sn);
               }
               (*pr)("%" PRIdaddr "-%" PRIdaddr "", bp->b_blkno,
                   bp->b_blkno + (bp->b_bcount - 1) / DEV_BSIZE);
       }
       if (lp && (blkdone >= 0 || bp->b_bcount <= lp->d_secsize)) {
               sn += lp->d_partitions[part].p_offset;
               (*pr)(" (%s%d bn %" PRIdaddr "; cn %" PRIdaddr "",
                   dname, unit, sn, sn / lp->d_secpercyl);
               sn %= lp->d_secpercyl;
               (*pr)(" tn %" PRIdaddr " sn %" PRIdaddr ")",
                   sn / lp->d_nsectors, sn % lp->d_nsectors);
       }
}

/*
* Searches the iostatlist for the disk corresponding to the
* name provided.
*/
struct disk *
disk_find(const char *name)
{
       struct io_stats *stat;

       stat = iostat_find(name);

       if ((stat != NULL) && (stat->io_type == IOSTAT_DISK))
               return stat->io_parent;

       return (NULL);
}

void
disk_init(struct disk *diskp, const char *name, const struct dkdriver *driver)
{
       u_int blocksize = DEV_BSIZE;

       /*
        * Initialize the wedge-related locks and other fields.
        */
       mutex_init(&diskp->dk_rawlock, MUTEX_DEFAULT, IPL_NONE);
       mutex_init(&diskp->dk_openlock, MUTEX_DEFAULT, IPL_NONE);
       LIST_INIT(&diskp->dk_wedges);
       diskp->dk_nwedges = 0;
       diskp->dk_labelsector = LABELSECTOR;
       diskp->dk_blkshift = DK_BSIZE2BLKSHIFT(blocksize);
       diskp->dk_byteshift = DK_BSIZE2BYTESHIFT(blocksize);
       diskp->dk_name = name;
       diskp->dk_driver = driver;
}

/*
* Rename a disk.
*/
void
disk_rename(struct disk *diskp, const char *name)
{

       diskp->dk_name = name;
       iostat_rename(diskp->dk_stats, diskp->dk_name);
}

/*
* Attach a disk.
*/
void
disk_attach(struct disk *diskp)
{

       /*
        * Allocate and initialize the disklabel structures.
        */
       diskp->dk_label = kmem_zalloc(sizeof(struct disklabel), KM_SLEEP);
       diskp->dk_cpulabel = kmem_zalloc(sizeof(struct cpu_disklabel),
           KM_SLEEP);

       /*
        * Set up the stats collection.
        */
       diskp->dk_stats = iostat_alloc(IOSTAT_DISK, diskp, diskp->dk_name);
}

int
disk_begindetach(struct disk *dk, int (*lastclose)(device_t),
   device_t self, int flags)
{
       int rc;

       rc = 0;
       mutex_enter(&dk->dk_openlock);
       if (dk->dk_openmask == 0)
               ;       /* nothing to do */
       else if ((flags & DETACH_FORCE) == 0)
               rc = EBUSY;
       else if (lastclose != NULL)
               rc = (*lastclose)(self);
       mutex_exit(&dk->dk_openlock);

       return rc;
}

/*
* Detach a disk.
*/
void
disk_detach(struct disk *diskp)
{

       /*
        * Remove from the drivelist.
        */
       iostat_free(diskp->dk_stats);

       /*
        * Release the disk-info dictionary.
        */
       if (diskp->dk_info) {
               prop_object_release(diskp->dk_info);
               diskp->dk_info = NULL;
       }

       /*
        * Free the space used by the disklabel structures.
        */
       kmem_free(diskp->dk_label, sizeof(*diskp->dk_label));
       kmem_free(diskp->dk_cpulabel, sizeof(*diskp->dk_cpulabel));
}

void
disk_destroy(struct disk *diskp)
{

       mutex_destroy(&diskp->dk_openlock);
       mutex_destroy(&diskp->dk_rawlock);
}

/*
* Mark the disk as having work queued for metrics collection.
*/
void
disk_wait(struct disk *diskp)
{

       iostat_wait(diskp->dk_stats);
}

/*
* Mark the disk as busy for metrics collection.
*/
void
disk_busy(struct disk *diskp)
{

       iostat_busy(diskp->dk_stats);
}

/*
* Finished disk operations, gather metrics.
*/
void
disk_unbusy(struct disk *diskp, long bcount, int read)
{

       iostat_unbusy(diskp->dk_stats, bcount, read);
}

/*
* Return true if disk has an I/O operation in flight.
*/
bool
disk_isbusy(struct disk *diskp)
{

       return iostat_isbusy(diskp->dk_stats);
}

/*
* Bounds checking against the media size, used for the raw partition.
* secsize, mediasize and b_blkno must all be the same units.
* Possibly this has to be DEV_BSIZE (512).
*/
int
bounds_check_with_mediasize(struct buf *bp, int secsize, uint64_t mediasize)
{
       int64_t sz;

       if (bp->b_blkno < 0) {
               /* Reject negative offsets immediately. */
               bp->b_error = EINVAL;
               return 0;
       }

       sz = howmany((int64_t)bp->b_bcount, secsize);

       /*
        * bp->b_bcount is a 32-bit value, and we rejected a negative
        * bp->b_blkno already, so "bp->b_blkno + sz" cannot overflow.
        */

       if (bp->b_blkno + sz > mediasize) {
               sz = mediasize - bp->b_blkno;
               if (sz == 0) {
                       /* If exactly at end of disk, return EOF. */
                       bp->b_resid = bp->b_bcount;
                       return 0;
               }
               if (sz < 0) {
                       /* If past end of disk, return EINVAL. */
                       bp->b_error = EINVAL;
                       return 0;
               }
               /* Otherwise, truncate request. */
               bp->b_bcount = sz * secsize;
       }

       return 1;
}

/*
* Determine the size of the transfer, and make sure it is
* within the boundaries of the partition. Adjust transfer
* if needed, and signal errors or early completion.
*/
int
bounds_check_with_label(struct disk *dk, struct buf *bp, int wlabel)
{
       struct disklabel *lp = dk->dk_label;
       struct partition *p = lp->d_partitions + DISKPART(bp->b_dev);
       uint64_t p_size, p_offset, labelsector;
       int64_t sz;

       if (bp->b_blkno < 0) {
               /* Reject negative offsets immediately. */
               bp->b_error = EINVAL;
               return -1;
       }

       /* Protect against division by zero. XXX: Should never happen?!?! */
       if ((lp->d_secsize / DEV_BSIZE) == 0 || lp->d_secpercyl == 0) {
               bp->b_error = EINVAL;
               return -1;
       }

       p_size = (uint64_t)p->p_size << dk->dk_blkshift;
       p_offset = (uint64_t)p->p_offset << dk->dk_blkshift;
#if RAW_PART == 3
       labelsector = lp->d_partitions[2].p_offset;
#else
       labelsector = lp->d_partitions[RAW_PART].p_offset;
#endif
       labelsector = (labelsector + dk->dk_labelsector) << dk->dk_blkshift;

       sz = howmany((int64_t)bp->b_bcount, DEV_BSIZE);

       /*
        * bp->b_bcount is a 32-bit value, and we rejected a negative
        * bp->b_blkno already, so "bp->b_blkno + sz" cannot overflow.
        */

       if (bp->b_blkno + sz > p_size) {
               sz = p_size - bp->b_blkno;
               if (sz == 0) {
                       /* If exactly at end of disk, return EOF. */
                       bp->b_resid = bp->b_bcount;
                       return 0;
               }
               if (sz < 0) {
                       /* If past end of disk, return EINVAL. */
                       bp->b_error = EINVAL;
                       return -1;
               }
               /* Otherwise, truncate request. */
               bp->b_bcount = sz << DEV_BSHIFT;
       }

       /* Overwriting disk label? */
       if (bp->b_blkno + p_offset <= labelsector &&
           bp->b_blkno + p_offset + sz > labelsector &&
           (bp->b_flags & B_READ) == 0 && !wlabel) {
               bp->b_error = EROFS;
               return -1;
       }

       /* calculate cylinder for disksort to order transfers with */
       bp->b_cylinder = (bp->b_blkno + p->p_offset) /
           (lp->d_secsize / DEV_BSIZE) / lp->d_secpercyl;
       return 1;
}

int
disk_read_sectors(void (*strat)(struct buf *), const struct disklabel *lp,
   struct buf *bp, unsigned int sector, int count)
{

       if ((lp->d_secsize / DEV_BSIZE) == 0 || lp->d_secpercyl == 0)
               return EINVAL;

       bp->b_blkno = btodb((off_t)sector * lp->d_secsize);
       bp->b_bcount = count * lp->d_secsize;
       bp->b_flags = (bp->b_flags & ~B_WRITE) | B_READ;
       bp->b_oflags &= ~BO_DONE;
       bp->b_cylinder = sector / lp->d_secpercyl;
       (*strat)(bp);
       return biowait(bp);
}

const char *
convertdisklabel(struct disklabel *lp, void (*strat)(struct buf *),
   struct buf *bp, uint32_t secperunit)
{
       struct partition rp, *altp, *p;
       int geom_ok;
       const char *str;

       memset(&rp, 0, sizeof(rp));
       rp.p_size = secperunit;
       rp.p_fstype = FS_UNUSED;

       /* If we can seek to d_secperunit - 1, believe the disk geometry. */
       if (secperunit != 0 &&
           disk_read_sectors(strat, lp, bp, secperunit - 1, 1) == 0)
               geom_ok = 1;
       else
               geom_ok = 0;

#if 0
       printf("%s: secperunit (%" PRIu32 ") %s\n", __func__,
           secperunit, geom_ok ? "ok" : "not ok");
#endif

       p = &lp->d_partitions[RAW_PART];
       if (RAW_PART == 'c' - 'a')
               altp = &lp->d_partitions['d' - 'a'];
       else
               altp = &lp->d_partitions['c' - 'a'];

       if (lp->d_npartitions > RAW_PART && p->p_offset == 0 && p->p_size != 0)
               return NULL;    /* already a raw partition */
       else if (lp->d_npartitions > MAX('c', 'd') - 'a' &&
                altp->p_offset == 0 && altp->p_size != 0) {
               /* alternate partition ('c' or 'd') is suitable for raw slot,
                * swap with 'd' or 'c'.
                */
               rp = *p;
               *p = *altp;
               *altp = rp;
               return NULL;
       } else if (lp->d_npartitions <= RAW_PART &&
                  lp->d_npartitions > 'c' - 'a') {
               /* No raw partition is present, but the alternate is present.
                * Copy alternate to raw partition.
                */
               lp->d_npartitions = RAW_PART + 1;
               *p = *altp;
               return NULL;
       } else if (!geom_ok)
               str = "no raw partition and disk reports bad geometry";
       else if (lp->d_npartitions <= RAW_PART) {
               memset(&lp->d_partitions[lp->d_npartitions], 0,
                   sizeof(struct partition) * (RAW_PART - lp->d_npartitions));
               *p = rp;
               lp->d_npartitions = RAW_PART + 1;
               return NULL;
       } else if (lp->d_npartitions < MAXPARTITIONS) {
               memmove(p + 1, p,
                   sizeof(struct partition) * (lp->d_npartitions - RAW_PART));
               *p = rp;
               lp->d_npartitions++;
               return NULL;
       } else
               str = "no raw partition and partition table is full";
#ifdef DIAGNOSTIC
       printf("Bad partition: %s\n", str);
       printf("type = %u, subtype = %u, typename = %s\n",
           lp->d_type, lp->d_subtype, lp->d_typename);
       printf("secsize = %u, nsectors = %u, ntracks = %u\n",
           lp->d_secsize, lp->d_nsectors, lp->d_ntracks);
       printf("ncylinders = %u, secpercyl = %u, secperunit = %u\n",
           lp->d_ncylinders, lp->d_secpercyl, lp->d_secperunit);
       printf("npartitions = %u\n", lp->d_npartitions);

       for (size_t i = 0; i < MIN(lp->d_npartitions, MAXPARTITIONS); i++) {
               p = &lp->d_partitions[i];
               printf("\t%c: offset = %u size = %u fstype = %u\n",
                   (char)(i + 'a'), p->p_offset, p->p_size, p->p_fstype);
       }
#endif
       return str;
}

/*
* disk_ioctl --
*      Generic disk ioctl handling.
*/
int
disk_ioctl(struct disk *dk, dev_t dev, u_long cmd, void *data, int flag,
   struct lwp *l)
{
       struct dkwedge_info *dkw;
       struct partinfo *pi;
       struct partition *dp;
#ifdef __HAVE_OLD_DISKLABEL
       struct disklabel newlabel;
#endif

       switch (cmd) {
       case DIOCGDISKINFO: {
               prop_dictionary_t disk_info;
               int error;

               mutex_enter(&dk->dk_openlock);
               if ((disk_info = dk->dk_info) == NULL) {
                       error = ENOTSUP;
               } else {
                       prop_object_retain(disk_info);
                       error = 0;
               }
               mutex_exit(&dk->dk_openlock);
               if (error)
                       return error;

               error = prop_dictionary_copyout_ioctl(data, cmd, disk_info);
               prop_object_release(disk_info);
               return error;
       }
       case DIOCGSECTORSIZE:
               *(u_int *)data = dk->dk_geom.dg_secsize;
               return 0;

       case DIOCGMEDIASIZE:
               *(off_t *)data = (off_t)dk->dk_geom.dg_secsize *
                   dk->dk_geom.dg_secperunit;
               return 0;
       default:
               break;
       }

       if (dev == NODEV)
               return EPASSTHROUGH;

       /* The following should be moved to dk_ioctl */
       switch (cmd) {
       case DIOCGDINFO:
               if (dk->dk_label == NULL)
                       return EBUSY;
               memcpy(data, dk->dk_label, sizeof (*dk->dk_label));
               return 0;

#ifdef __HAVE_OLD_DISKLABEL
       case ODIOCGDINFO:
               if (dk->dk_label == NULL)
                       return EBUSY;
               memcpy(&newlabel, dk->dk_label, sizeof(newlabel));
               if (newlabel.d_npartitions > OLDMAXPARTITIONS)
                       return ENOTTY;
               memcpy(data, &newlabel, sizeof(struct olddisklabel));
               return 0;
#endif

       case DIOCGPARTINFO:
               pi = data;
               memset(pi, 0, sizeof(*pi));
               pi->pi_secsize = dk->dk_geom.dg_secsize;
               pi->pi_bsize = MAX(BLKDEV_IOSIZE, pi->pi_secsize);

               if (DISKPART(dev) == RAW_PART) {
                       pi->pi_size = dk->dk_geom.dg_secperunit;
                       return 0;
               }

               if (dk->dk_label == NULL)
                       return EBUSY;

               dp = &dk->dk_label->d_partitions[DISKPART(dev)];
               pi->pi_offset = dp->p_offset;
               pi->pi_size = dp->p_size;

               pi->pi_fstype = dp->p_fstype;
               pi->pi_frag = dp->p_frag;
               pi->pi_fsize = dp->p_fsize;
               pi->pi_cpg = dp->p_cpg;

               /*
                * dholland 20130616: XXX this logic should not be
                * here. It is here because the old buffer cache
                * demands that all accesses to the same blocks need
                * to be the same size; but it only works for FFS and
                * nowadays I think it'll fail silently if the size
                * info in the disklabel is wrong. (Or missing.) The
                * buffer cache needs to be smarter; or failing that
                * we need a reliable way here to get the right block
                * size; or a reliable way to guarantee that (a) the
                * fs is not mounted when we get here and (b) any
                * buffers generated here will get purged when the fs
                * does get mounted.
                */
               if (dp->p_fstype == FS_BSDFFS &&
                   dp->p_frag != 0 && dp->p_fsize != 0)
                       pi->pi_bsize = dp->p_frag * dp->p_fsize;
               return 0;

       case DIOCAWEDGE:
               if ((flag & FWRITE) == 0)
                       return EBADF;

               dkw = data;
               strlcpy(dkw->dkw_parent, dk->dk_name, sizeof(dkw->dkw_parent));
               return dkwedge_add(dkw);

       case DIOCDWEDGE:
               if ((flag & FWRITE) == 0)
                       return EBADF;

               dkw = data;
               strlcpy(dkw->dkw_parent, dk->dk_name, sizeof(dkw->dkw_parent));
               return dkwedge_del(dkw);

       case DIOCLWEDGES:
               return dkwedge_list(dk, data, l);

       case DIOCMWEDGES:
               if ((flag & FWRITE) == 0)
                       return EBADF;

               dkwedge_discover(dk);
               return 0;

       case DIOCRMWEDGES:
               if ((flag & FWRITE) == 0)
                       return EBADF;

               dkwedge_delidle(dk);
               return 0;

       case DIOCGSECTORALIGN: {
               struct disk_sectoralign * const dsa = data;
               const int part = DISKPART(dev);

               dsa->dsa_alignment = MAX(1u, dk->dk_geom.dg_physsecsize /
                   dk->dk_geom.dg_secsize);
               dsa->dsa_firstaligned = dk->dk_geom.dg_alignedsec;

               if (part != RAW_PART) {
                       struct disklabel * const lp = dk->dk_label;
                       daddr_t offset = lp->d_partitions[part].p_offset;
                       uint32_t r = offset % dsa->dsa_alignment;

                       if (r <= dsa->dsa_firstaligned)
                               dsa->dsa_firstaligned -= r;
                       else
                               dsa->dsa_firstaligned += dsa->dsa_alignment - r;
               }
               dsa->dsa_firstaligned %= dsa->dsa_alignment;
               return 0;
       }

       default:
               return EPASSTHROUGH;
       }
}

/*
* disk_set_info --
*      Canonicalize dk->dk_geom and set some parameters.
*
*      If disk_set_info can happen concurrently with disk_ioctl in a
*      driver, the driver must serialize calls to disk_set_info with
*      dk_openlock.
*/
void
disk_set_info(device_t dev, struct disk *dk, const char *type)
{
       struct disk_geom *dg = &dk->dk_geom;

       if (dg->dg_secsize == 0) {
#ifdef DIAGNOSTIC
               printf("%s: fixing 0 sector size\n", dk->dk_name);
#endif
               dg->dg_secsize = DEV_BSIZE;
       }

       dk->dk_blkshift = DK_BSIZE2BLKSHIFT(dg->dg_secsize);
       dk->dk_byteshift = DK_BSIZE2BYTESHIFT(dg->dg_secsize);

       if (dg->dg_secperunit == 0) {
#ifdef DIAGNOSTIC
               if (dg->dg_ncylinders == 0) {
                       printf("%s: secperunit and ncylinders are zero\n",
                           dk->dk_name);
               }
               if (dg->dg_nsectors == 0 || dg->dg_ntracks == 0) {
                       printf("%s: secperunit and (sectors or tracks) "
                           "are zero\n", dk->dk_name);
               }
#endif
               dg->dg_secperunit = (int64_t) dg->dg_nsectors *
                   dg->dg_ntracks * dg->dg_ncylinders;
       }

       if (dg->dg_ncylinders == 0) {
               if (dg->dg_ntracks && dg->dg_nsectors)
                       dg->dg_ncylinders = dg->dg_secperunit /
                           (dg->dg_ntracks * dg->dg_nsectors);
       }

       prop_dictionary_t disk_info, odisk_info, geom;

       disk_info = prop_dictionary_create();
       geom = prop_dictionary_create();

       prop_dictionary_set_uint64(geom, "sectors-per-unit",
           dg->dg_secperunit);

       prop_dictionary_set_uint32(geom, "sector-size", dg->dg_secsize);

       if (dg->dg_nsectors)
               prop_dictionary_set_uint16(geom, "sectors-per-track",
                   dg->dg_nsectors);

       if (dg->dg_ntracks)
               prop_dictionary_set_uint16(geom, "tracks-per-cylinder",
                   dg->dg_ntracks);

       if (dg->dg_ncylinders)
               prop_dictionary_set_uint64(geom, "cylinders-per-unit",
                   dg->dg_ncylinders);

       if (dg->dg_physsecsize) {
               prop_dictionary_set_uint32(geom, "physical-sector-size",
                   dg->dg_physsecsize);
               prop_dictionary_set_uint32(geom, "aligned-sector",
                   dg->dg_alignedsec);
       }

       prop_dictionary_set(disk_info, "geometry", geom);

       if (type)
               prop_dictionary_set_string_nocopy(disk_info, "type", type);

       prop_object_release(geom);

       odisk_info = dk->dk_info;
       dk->dk_info = disk_info;

       if (dev)
               prop_dictionary_set(device_properties(dev), "disk-info",
                   disk_info);

       /*
        * Don't release disk_info here; we keep a reference to it.
        * disk_detach() will release it when we go away.
        */
       if (odisk_info)
               prop_object_release(odisk_info);
}

int
disklabel_dev_unit(dev_t dev)
{

       return DISKUNIT(dev);
}