Pull morse(6) into the new millenium and teach it to use sound(4).

[dragonfly.git] / sys / kern / subr_disk.c

/*
 * Copyright (c) 2003,2004 The DragonFly Project.  All rights reserved.
 * 
 * This code is derived from software contributed to The DragonFly Project
 * by Matthew Dillon <dillon@backplane.com>
 * 
 * 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 DragonFly Project 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 COPYRIGHT HOLDERS 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
 * COPYRIGHT HOLDERS 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.
 * 
 * ----------------------------------------------------------------------------
 * "THE BEER-WARE LICENSE" (Revision 42):
 * <phk@FreeBSD.ORG> wrote this file.  As long as you retain this notice you
 * can do whatever you want with this stuff. If we meet some day, and you think
 * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
 * ----------------------------------------------------------------------------
 *
 * 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. 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.
 *
 *      @(#)ufs_disksubr.c      8.5 (Berkeley) 1/21/94
 * $FreeBSD: src/sys/kern/subr_disk.c,v 1.20.2.6 2001/10/05 07:14:57 peter Exp $
 * $FreeBSD: src/sys/ufs/ufs/ufs_disksubr.c,v 1.44.2.3 2001/03/05 05:42:19 obrien Exp $
 * $DragonFly: src/sys/kern/subr_disk.c,v 1.28 2006/12/26 11:01:07 swildner Exp $
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/sysctl.h>
#include <sys/buf.h>
#include <sys/conf.h>
#include <sys/disklabel.h>
#include <sys/diskslice.h>
#include <sys/disk.h>
#include <sys/malloc.h>
#include <sys/sysctl.h>
#include <machine/md_var.h>
#include <sys/ctype.h>
#include <sys/syslog.h>
#include <sys/device.h>
#include <sys/msgport.h>
#include <sys/msgport2.h>
#include <sys/buf2.h>

static MALLOC_DEFINE(M_DISK, "disk", "disk data");

static d_open_t diskopen;
static d_close_t diskclose; 
static d_ioctl_t diskioctl;
static d_strategy_t diskstrategy;
static d_psize_t diskpsize;
static d_clone_t diskclone;
static d_dump_t diskdump;

static LIST_HEAD(, disk) disklist = LIST_HEAD_INITIALIZER(&disklist);

static struct dev_ops disk_ops = {
        { "disk" },
        .d_open = diskopen,
        .d_close = diskclose,
        .d_read = physread,
        .d_write = physwrite,
        .d_ioctl = diskioctl,
        .d_strategy = diskstrategy,
        .d_dump = diskdump,
        .d_psize = diskpsize,
        .d_clone = diskclone
};

/*
 * Create a raw device for the dev_ops template (which is returned).  Also
 * create a slice and unit managed disk and overload the user visible
 * device space with it.
 *
 * NOTE: The returned raw device is NOT a slice and unit managed device.
 * It is an actual raw device representing the raw disk as specified by
 * the passed dev_ops.  The disk layer not only returns such a raw device,
 * it also uses it internally when passing (modified) commands through.
 */
cdev_t
disk_create(int unit, struct disk *dp, int flags, struct dev_ops *raw_ops)
{
        cdev_t rawdev;
        struct dev_ops *dev_ops;

        /*
         * Create the raw backing device
         */
        compile_dev_ops(raw_ops);
        rawdev = make_dev(raw_ops,
                            dkmakeminor(unit, WHOLE_DISK_SLICE, RAW_PART),
                            UID_ROOT, GID_OPERATOR, 0640,
                            "%s%d", raw_ops->head.name, unit);

        bzero(dp, sizeof(*dp));

        /*
         * We install a custom cdevsw rather then the passed cdevsw,
         * and save our disk structure in d_data so we can get at it easily
         * without any complex cloning code.
         */
        dev_ops = dev_ops_add_override(rawdev, &disk_ops,
                                       dkunitmask(), dkmakeunit(unit));
        dev_ops->head.data = dp;

        dp->d_rawdev = rawdev;
        dp->d_raw_ops = raw_ops;
        dp->d_dev_ops = dev_ops;
        dp->d_cdev = make_dev(dev_ops, 
                            dkmakeminor(unit, WHOLE_DISK_SLICE, RAW_PART),
                            UID_ROOT, GID_OPERATOR, 0640,
                            "%s%d", dev_ops->head.name, unit);

        dp->d_dsflags = flags;
        LIST_INSERT_HEAD(&disklist, dp, d_list);
        return (dp->d_rawdev);
}

/*
 * This routine is called when an adapter detaches.  The higher level
 * managed disk device is destroyed while the lower level raw device is
 * released.
 */
void
disk_destroy(struct disk *disk)
{
        if (disk->d_dev_ops) {
            dev_ops_remove(disk->d_dev_ops, dkunitmask(), 
                            dkmakeunit(dkunit(disk->d_cdev)));
            LIST_REMOVE(disk, d_list);
        }
        if (disk->d_raw_ops) {
            destroy_all_devs(disk->d_raw_ops, dkunitmask(), 
                            dkmakeunit(dkunit(disk->d_rawdev)));
        }
        bzero(disk, sizeof(*disk));
}

int
disk_dumpcheck(cdev_t dev, u_int *count, u_int *blkno, u_int *secsize)
{
        struct disk *dp;
        struct disklabel *dl;
        u_int boff;

        dp = dev->si_disk;
        if (!dp)
                return (ENXIO);
        if (!dp->d_slice)
                return (ENXIO);
        dl = dsgetlabel(dev, dp->d_slice);
        if (!dl)
                return (ENXIO);
        *count = Maxmem * (PAGE_SIZE / dl->d_secsize);
        if (dumplo <= LABELSECTOR || 
            (dumplo + *count > dl->d_partitions[dkpart(dev)].p_size))
                return (EINVAL);
        boff = dl->d_partitions[dkpart(dev)].p_offset +
            dp->d_slice->dss_slices[dkslice(dev)].ds_offset;
        *blkno = boff + dumplo;
        *secsize = dl->d_secsize;
        return (0);
        
}

void 
disk_invalidate (struct disk *disk)
{
        if (disk->d_slice)
                dsgone(&disk->d_slice);
}

struct disk *
disk_enumerate(struct disk *disk)
{
        if (!disk)
                return (LIST_FIRST(&disklist));
        else
                return (LIST_NEXT(disk, d_list));
}

static 
int
sysctl_disks(SYSCTL_HANDLER_ARGS)
{
        struct disk *disk;
        int error, first;

        disk = NULL;
        first = 1;

        while ((disk = disk_enumerate(disk))) {
                if (!first) {
                        error = SYSCTL_OUT(req, " ", 1);
                        if (error)
                                return error;
                } else {
                        first = 0;
                }
                error = SYSCTL_OUT(req, disk->d_rawdev->si_name,
                                   strlen(disk->d_rawdev->si_name));
                if (error)
                        return error;
        }
        error = SYSCTL_OUT(req, "", 1);
        return error;
}
 
SYSCTL_PROC(_kern, OID_AUTO, disks, CTLTYPE_STRING | CTLFLAG_RD, 0, NULL, 
    sysctl_disks, "A", "names of available disks");

/*
 * Open a disk device or partition.
 */
static
int
diskopen(struct dev_open_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        struct disk *dp;
        int error;

        /*
         * dp can't be NULL here XXX.
         */
        dp = dev->si_disk;
        if (dp == NULL)
                return (ENXIO);
        error = 0;

        /*
         * Deal with open races
         */
        while (dp->d_flags & DISKFLAG_LOCK) {
                dp->d_flags |= DISKFLAG_WANTED;
                error = tsleep(dp, PCATCH, "diskopen", hz);
                if (error)
                        return (error);
        }
        dp->d_flags |= DISKFLAG_LOCK;

        /*
         * Open the underlying raw device.
         */
        if (!dsisopen(dp->d_slice)) {
#if 0
                if (!pdev->si_iosize_max)
                        pdev->si_iosize_max = dev->si_iosize_max;
#endif
                error = dev_dopen(dp->d_rawdev, ap->a_oflags,
                                  ap->a_devtype, ap->a_cred);
        }

        /*
         * Inherit properties from the underlying device now that it is
         * open.
         */
        dev_dclone(dev);

        if (error)
                goto out;
        
        error = dsopen(dev, ap->a_devtype, dp->d_dsflags,
                       &dp->d_slice, &dp->d_label);

        if (!dsisopen(dp->d_slice)) 
                dev_dclose(dp->d_rawdev, ap->a_oflags, ap->a_devtype);
out:    
        dp->d_flags &= ~DISKFLAG_LOCK;
        if (dp->d_flags & DISKFLAG_WANTED) {
                dp->d_flags &= ~DISKFLAG_WANTED;
                wakeup(dp);
        }
        
        return(error);
}

/*
 * Close a disk device or partition
 */
static
int
diskclose(struct dev_close_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        struct disk *dp;
        int error;

        error = 0;
        dp = dev->si_disk;

        dsclose(dev, ap->a_devtype, dp->d_slice);
        if (!dsisopen(dp->d_slice))
                error = dev_dclose(dp->d_rawdev, ap->a_fflag, ap->a_devtype);
        return (error);
}

/*
 * First execute the ioctl on the disk device, and if it isn't supported 
 * try running it on the backing device.
 */
static
int
diskioctl(struct dev_ioctl_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        struct disk *dp;
        int error;

        dp = dev->si_disk;
        if (dp == NULL)
                return (ENXIO);
        error = dsioctl(dev, ap->a_cmd, ap->a_data, ap->a_fflag, &dp->d_slice);
        if (error == ENOIOCTL) {
                error = dev_dioctl(dp->d_rawdev, ap->a_cmd, ap->a_data,
                                   ap->a_fflag, ap->a_cred);
        }
        return (error);
}

/*
 * Execute strategy routine
 */
static
int
diskstrategy(struct dev_strategy_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        struct bio *bio = ap->a_bio;
        struct bio *nbio;
        struct disk *dp;

        dp = dev->si_disk;

        if (dp == NULL) {
                bio->bio_buf->b_error = ENXIO;
                bio->bio_buf->b_flags |= B_ERROR;
                biodone(bio);
                return(0);
        }
        KKASSERT(dev->si_disk == dp);

        /*
         * The dscheck() function will also transform the slice relative
         * block number i.e. bio->bio_offset into a block number that can be
         * passed directly to the underlying raw device.  If dscheck()
         * returns NULL it will have handled the bio for us (e.g. EOF
         * or error due to being beyond the device size).
         */
        if ((nbio = dscheck(dev, bio, dp->d_slice)) != NULL)
                dev_dstrategy(dp->d_rawdev, nbio);
        else
                biodone(bio);
        return(0);
}

/*
 * Return the partition size in ?blocks?
 */
static
int
diskpsize(struct dev_psize_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        struct disk *dp;

        dp = dev->si_disk;
        if (dp == NULL)
                return(ENODEV);
        ap->a_result = dssize(dev, &dp->d_slice);
        return(0);
}

/*
 * When new device entries are instantiated, make sure they inherit our
 * si_disk structure and block and iosize limits from the raw device.
 *
 * This routine is always called synchronously in the context of the 
 * client.
 *
 * XXX The various io and block size constraints are not always initialized
 * properly by devices.
 */
static
int
diskclone(struct dev_clone_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        struct disk *dp;

        dp = dev->si_ops->head.data;
        KKASSERT(dp != NULL);
        dev->si_disk = dp;
        dev->si_iosize_max = dp->d_rawdev->si_iosize_max;
        dev->si_bsize_phys = dp->d_rawdev->si_bsize_phys;
        dev->si_bsize_best = dp->d_rawdev->si_bsize_best;
        return(0);
}

int
diskdump(struct dev_dump_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        struct disk *dp = dev->si_ops->head.data;
        int error;

        error = disk_dumpcheck(dev, &ap->a_count, &ap->a_blkno, &ap->a_secsize);
        if (error == 0) {
                ap->a_head.a_dev = dp->d_rawdev;
                error = dev_doperate(&ap->a_head);
        }

        return(error);
}


SYSCTL_INT(_debug_sizeof, OID_AUTO, disklabel, CTLFLAG_RD, 
    0, sizeof(struct disklabel), "sizeof(struct disklabel)");

SYSCTL_INT(_debug_sizeof, OID_AUTO, diskslices, CTLFLAG_RD, 
    0, sizeof(struct diskslices), "sizeof(struct diskslices)");

SYSCTL_INT(_debug_sizeof, OID_AUTO, disk, CTLFLAG_RD, 
    0, sizeof(struct disk), "sizeof(struct disk)");


/*
 * Seek sort for disks.
 *
 * The bio_queue keep two queues, sorted in ascending block order.  The first
 * queue holds those requests which are positioned after the current block
 * (in the first request); the second, which starts at queue->switch_point,
 * holds requests which came in after their block number was passed.  Thus
 * we implement a one way scan, retracting after reaching the end of the drive
 * to the first request on the second queue, at which time it becomes the
 * first queue.
 *
 * A one-way scan is natural because of the way UNIX read-ahead blocks are
 * allocated.
 */
void
bioqdisksort(struct bio_queue_head *bioq, struct bio *bio)
{
        struct bio *bq;
        struct bio *bn;
        struct bio *be;
        
        be = TAILQ_LAST(&bioq->queue, bio_queue);
        /*
         * If the queue is empty or we are an
         * ordered transaction, then it's easy.
         */
        if ((bq = bioq_first(bioq)) == NULL || 
            (bio->bio_buf->b_flags & B_ORDERED) != 0) {
                bioq_insert_tail(bioq, bio);
                return;
        } else if (bioq->insert_point != NULL) {

                /*
                 * A certain portion of the list is
                 * "locked" to preserve ordering, so
                 * we can only insert after the insert
                 * point.
                 */
                bq = bioq->insert_point;
        } else {

                /*
                 * If we lie before the last removed (currently active)
                 * request, and are not inserting ourselves into the
                 * "locked" portion of the list, then we must add ourselves
                 * to the second request list.
                 */
                if (bio->bio_offset < bioq->last_offset) {
                        bq = bioq->switch_point;
                        /*
                         * If we are starting a new secondary list,
                         * then it's easy.
                         */
                        if (bq == NULL) {
                                bioq->switch_point = bio;
                                bioq_insert_tail(bioq, bio);
                                return;
                        }
                        /*
                         * If we lie ahead of the current switch point,
                         * insert us before the switch point and move
                         * the switch point.
                         */
                        if (bio->bio_offset < bq->bio_offset) {
                                bioq->switch_point = bio;
                                TAILQ_INSERT_BEFORE(bq, bio, bio_act);
                                return;
                        }
                } else {
                        if (bioq->switch_point != NULL)
                                be = TAILQ_PREV(bioq->switch_point,
                                                bio_queue, bio_act);
                        /*
                         * If we lie between last_offset and bq,
                         * insert before bq.
                         */
                        if (bio->bio_offset < bq->bio_offset) {
                                TAILQ_INSERT_BEFORE(bq, bio, bio_act);
                                return;
                        }
                }
        }

        /*
         * Request is at/after our current position in the list.
         * Optimize for sequential I/O by seeing if we go at the tail.
         */
        if (bio->bio_offset > be->bio_offset) {
                TAILQ_INSERT_AFTER(&bioq->queue, be, bio, bio_act);
                return;
        }

        /* Otherwise, insertion sort */
        while ((bn = TAILQ_NEXT(bq, bio_act)) != NULL) {
                
                /*
                 * We want to go after the current request if it is the end
                 * of the first request list, or if the next request is a
                 * larger cylinder than our request.
                 */
                if (bn == bioq->switch_point
                 || bio->bio_offset < bn->bio_offset)
                        break;
                bq = bn;
        }
        TAILQ_INSERT_AFTER(&bioq->queue, bq, bio, bio_act);
}


/*
 * Attempt to read a disk label from a device using the indicated strategy
 * routine.  The label must be partly set up before this: secpercyl, secsize
 * and anything required in the strategy routine (e.g., dummy bounds for the
 * partition containing the label) must be filled in before calling us.
 * Returns NULL on success and an error string on failure.
 */
char *
readdisklabel(cdev_t dev, struct disklabel *lp)
{
        struct buf *bp;
        struct disklabel *dlp;
        char *msg = NULL;

        bp = geteblk((int)lp->d_secsize);
        bp->b_bio1.bio_offset = (off_t)LABELSECTOR * lp->d_secsize;
        bp->b_bcount = lp->d_secsize;
        bp->b_flags &= ~B_INVAL;
        bp->b_cmd = BUF_CMD_READ;
        dev_dstrategy(dev, &bp->b_bio1);
        if (biowait(bp))
                msg = "I/O error";
        else for (dlp = (struct disklabel *)bp->b_data;
            dlp <= (struct disklabel *)((char *)bp->b_data +
            lp->d_secsize - sizeof(*dlp));
            dlp = (struct disklabel *)((char *)dlp + sizeof(long))) {
                if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC) {
                        if (msg == NULL)
                                msg = "no disk label";
                } else if (dlp->d_npartitions > MAXPARTITIONS ||
                           dkcksum(dlp) != 0)
                        msg = "disk label corrupted";
                else {
                        *lp = *dlp;
                        msg = NULL;
                        break;
                }
        }
        bp->b_flags |= B_INVAL | B_AGE;
        brelse(bp);
        return (msg);
}

/*
 * Check new disk label for sensibility before setting it.
 */
int
setdisklabel(struct disklabel *olp, struct disklabel *nlp, u_long openmask)
{
        int i;
        struct partition *opp, *npp;

        /*
         * Check it is actually a disklabel we are looking at.
         */
        if (nlp->d_magic != DISKMAGIC || nlp->d_magic2 != DISKMAGIC ||
            dkcksum(nlp) != 0)
                return (EINVAL);
        /*
         * For each partition that we think is open,
         */
        while ((i = ffs((long)openmask)) != 0) {
                i--;
                /*
                 * Check it is not changing....
                 */
                openmask &= ~(1 << i);
                if (nlp->d_npartitions <= i)
                        return (EBUSY);
                opp = &olp->d_partitions[i];
                npp = &nlp->d_partitions[i];
                if (npp->p_offset != opp->p_offset || npp->p_size < opp->p_size)
                        return (EBUSY);
                /*
                 * Copy internally-set partition information
                 * if new label doesn't include it.             XXX
                 * (If we are using it then we had better stay the same type)
                 * This is possibly dubious, as someone else noted (XXX)
                 */
                if (npp->p_fstype == FS_UNUSED && opp->p_fstype != FS_UNUSED) {
                        npp->p_fstype = opp->p_fstype;
                        npp->p_fsize = opp->p_fsize;
                        npp->p_frag = opp->p_frag;
                        npp->p_cpg = opp->p_cpg;
                }
        }
        nlp->d_checksum = 0;
        nlp->d_checksum = dkcksum(nlp);
        *olp = *nlp;
        return (0);
}

/*
 * Write disk label back to device after modification.
 */
int
writedisklabel(cdev_t dev, struct disklabel *lp)
{
        struct buf *bp;
        struct disklabel *dlp;
        int error = 0;

        if (lp->d_partitions[RAW_PART].p_offset != 0)
                return (EXDEV);                 /* not quite right */
        bp = geteblk((int)lp->d_secsize);
        bp->b_bio1.bio_offset = (off_t)LABELSECTOR * lp->d_secsize;
        bp->b_bcount = lp->d_secsize;
#if 1
        /*
         * We read the label first to see if it's there,
         * in which case we will put ours at the same offset into the block..
         * (I think this is stupid [Julian])
         * Note that you can't write a label out over a corrupted label!
         * (also stupid.. how do you write the first one? by raw writes?)
         */
        bp->b_flags &= ~B_INVAL;
        bp->b_cmd = BUF_CMD_READ;
        dev_dstrategy(dkmodpart(dev, RAW_PART), &bp->b_bio1);
        error = biowait(bp);
        if (error)
                goto done;
        for (dlp = (struct disklabel *)bp->b_data;
            dlp <= (struct disklabel *)
              ((char *)bp->b_data + lp->d_secsize - sizeof(*dlp));
            dlp = (struct disklabel *)((char *)dlp + sizeof(long))) {
                if (dlp->d_magic == DISKMAGIC && dlp->d_magic2 == DISKMAGIC &&
                    dkcksum(dlp) == 0) {
                        *dlp = *lp;
                        bp->b_cmd = BUF_CMD_WRITE;
                        dev_dstrategy(dkmodpart(dev, RAW_PART), &bp->b_bio1);
                        error = biowait(bp);
                        goto done;
                }
        }
        error = ESRCH;
done:
#else
        bzero(bp->b_data, lp->d_secsize);
        dlp = (struct disklabel *)bp->b_data;
        *dlp = *lp;
        bp->b_flags &= ~B_INVAL;
        bp->b_cmd = BUF_CMD_WRITE;
        BUF_STRATEGY(bp, 1);
        error = biowait(bp);
#endif
        bp->b_flags |= B_INVAL | B_AGE;
        brelse(bp);
        return (error);
}

/*
 * 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 kprintf
 * if pri is LOG_PRINTF, otherwise it uses log at the specified priority.
 * The message should be completed (with at least a newline) with kprintf
 * or log(-1, ...), respectively.  There is no trailing space.
 */
void
diskerr(struct bio *bio, cdev_t dev, const char *what, int pri, 
        int donecnt, struct disklabel *lp)
{
        struct buf *bp = bio->bio_buf;
        int unit = dkunit(dev);
        int slice = dkslice(dev);
        int part = dkpart(dev);
        char partname[2];
        char *sname;

        sname = dsname(dev, unit, slice, part, partname);
        kprintf("%s%s: %s %sing ", sname, partname, what,
              (bp->b_cmd == BUF_CMD_READ) ? "read" : "writ");
        kprintf("offset %012llx for %d", bio->bio_offset, bp->b_bcount);
        if (donecnt)
                kprintf(" (%d bytes completed)", donecnt);
}