/*-
 * Copyright (c) 1997, 1998
 *      Nan Yang Computer Services Limited.  All rights reserved.
 *
 *  This software is distributed under the so-called ``Berkeley
 *  License'':
 *
 * 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 Nan Yang Computer
 *      Services Limited.
 * 4. Neither the name of the Company 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 ``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 company 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.
 *
 * $Id: vinumio.c,v 1.30 2000/05/10 23:23:30 grog Exp grog $
 * $FreeBSD: src/sys/dev/vinum/vinumio.c,v 1.52.2.6 2002/05/02 08:43:44 grog Exp $
 */

#include "vinumhdr.h"
#include "request.h"
#include <vm/vm_zone.h>
#include <sys/nlookup.h>

static char *sappend(char *txt, char *s);
static int drivecmp(const void *va, const void *vb);

/*
 * Open the device associated with the drive, and set drive's vp.
 * Return an error number
 */
int
open_drive(struct drive *drive, struct proc *p, int verbose)
{
    struct nlookupdata nd;
    int error;

    /*
     * Fail if already open
     */
    if (drive->flags & VF_OPEN)
        return EBUSY;

    if (rootdev) {
        /*
         * Open via filesystem (future)
         */
        error = nlookup_init(&nd, drive->devicename, UIO_SYSSPACE, NLC_FOLLOW);
        if (error)
            return error;
        error = vn_open(&nd, NULL, FREAD|FWRITE, 0);
        drive->vp = nd.nl_open_vp;
        nd.nl_open_vp = NULL;
        nlookup_done(&nd);
    } else {
        /*
         * Open via synthesized vnode backed by disk device
         */
        error = vn_opendisk(drive->devicename, FREAD|FWRITE, &drive->vp);
        if (error)
            return error;
    }

    if (error == 0 && drive->vp == NULL)
        error = ENODEV;

    /*
     * A huge amount of pollution all over vinum requires that our low
     * level drive be a device.
     */
    if (error == 0 && drive->vp->v_type != VCHR) {
        vn_close(drive->vp, FREAD|FWRITE, NULL);
        drive->vp = NULL;
        error = ENODEV;
    }
    if (error) {
        drive->state = drive_down;
        if (verbose) {
            log(LOG_WARNING,
                "vinum open_drive %s: failed with error %d\n",
                drive->devicename, error);
        }
    } else {
        drive->dev = drive->vp->v_rdev;
        drive->flags |= VF_OPEN;
    }
    drive->lasterror = error;
    return error;
}

/*
 * Set some variables in the drive struct
 * in more convenient form.  Return error indication
 */
int
set_drive_parms(struct drive *drive)
{
    drive->blocksize = BLKDEV_IOSIZE;                       /* do we need this? */
    drive->secsperblock = drive->blocksize                  /* number of sectors per block */
        / drive->partinfo.media_blksize;

    /* Now update the label part */
    bcopy(hostname, drive->label.sysname, VINUMHOSTNAMELEN); /* put in host name */
    getmicrotime(&drive->label.date_of_birth);              /* and current time */
    drive->label.drive_size = drive->partinfo.media_size;
#ifdef VINUMDEBUG
    if (debug & DEBUG_BIGDRIVE)                             /* pretend we're 100 times as big */
        drive->label.drive_size *= 100;
#endif

    /* number of sectors available for subdisks */
    drive->sectors_available = drive->label.drive_size / DEV_BSIZE - DATASTART;

    /*
     * Bug in 3.0 as of January 1998: you can open
     * non-existent slices.  They have a length of 0.
     */
    if (drive->label.drive_size < MINVINUMSLICE) {          /* too small to worry about */
        set_drive_state(drive->driveno, drive_down, setstate_force);
        drive->lasterror = ENOSPC;
        return ENOSPC;
    }
    drive->freelist_size = INITIAL_DRIVE_FREELIST;          /* initial number of entries */
    drive->freelist = (struct drive_freelist *)
        Malloc(INITIAL_DRIVE_FREELIST * sizeof(struct drive_freelist));
    if (drive->freelist == NULL)                            /* can't malloc, dammit */
        return ENOSPC;
    drive->freelist_entries = 1;                            /* just (almost) the complete drive */
    drive->freelist[0].offset = DATASTART;                  /* starts here */
    drive->freelist[0].sectors = (drive->label.drive_size >> DEV_BSHIFT) - DATASTART; /* and it's this long */
    if (drive->label.name[0] != '\0')                       /* got a name */
        set_drive_state(drive->driveno, drive_up, setstate_force); /* our drive is accessible */
    else                                                    /* we know about it, but that's all */
        drive->state = drive_referenced;
    return 0;
}

/*
 * Initialize a drive: open the device and add device
 * information
 */
int
init_drive(struct drive *drive, int verbose)
{
    if (drive->devicename[0] != '/') {
        drive->lasterror = EINVAL;
        log(LOG_ERR, "vinum: Can't open drive without drive name (%s)\n",
            drive->devicename);
        return EINVAL;
    }
    drive->lasterror = open_drive(drive, curproc, verbose); /* open the drive */
    if (drive->lasterror)
        return drive->lasterror;

    drive->lasterror = VOP_IOCTL(drive->vp, DIOCGPART,
                                 (caddr_t)&drive->partinfo, FREAD|FWRITE,
                                 proc0.p_ucred, NULL);
    if (drive->lasterror) {
        if (verbose)
            log(LOG_WARNING,
                "vinum open_drive %s: Can't get partition information, drive->lasterror %d\n",
                drive->devicename,
                drive->lasterror);
        close_drive(drive);
        return drive->lasterror;
    }
    if (drive->partinfo.fstype != FS_VINUM &&
        !kuuid_is_vinum(&drive->partinfo.fstype_uuid)
    ) {  
        drive->lasterror = EFTYPE;
        if (verbose)
            log(LOG_WARNING,
                "vinum open_drive %s: Wrong partition type for vinum\n",
                drive->devicename);
        close_drive(drive);
        return EFTYPE;
    }
    return set_drive_parms(drive);                          /* set various odds and ends */
}

/* Close a drive if it's open. */
void
close_drive(struct drive *drive)
{
    LOCKDRIVE(drive);                                       /* keep the daemon out */
    if (drive->flags & VF_OPEN)
        close_locked_drive(drive);                          /* and close it */
    if (drive->state > drive_down)                          /* if it's up */
        drive->state = drive_down;                          /* make sure it's down */
    unlockdrive(drive);
}

/*
 * Real drive close code, called with drive already locked.
 * We have also checked that the drive is open.  No errors.
 */
void
close_locked_drive(struct drive *drive)
{
    /*
     * If we can't access the drive, we can't flush
     * the queues, which spec_close() will try to
     * do.  Get rid of them here first.
     */
    if (drive->vp) {
        drive->lasterror = vn_close(drive->vp, FREAD|FWRITE, NULL);
        drive->vp = NULL;
    }
    drive->flags &= ~VF_OPEN;
}

/*
 * Remove drive from the configuration.
 * Caller must ensure that it isn't active.
 */
void
remove_drive(int driveno)
{
    struct drive *drive = &vinum_conf.drive[driveno];
    struct vinum_hdr *vhdr;                                 /* buffer for header */
    int error;

    if (drive->state > drive_referenced) {                  /* real drive */
        if (drive->state == drive_up) {
            vhdr = (struct vinum_hdr *) Malloc(VINUMHEADERLEN); /* allocate buffer */
            CHECKALLOC(vhdr, "Can't allocate memory");
            error = read_drive(drive, (void *) vhdr, VINUMHEADERLEN, VINUM_LABEL_OFFSET);
            if (error)
                drive->lasterror = error;
            else {
                vhdr->magic = VINUM_NOMAGIC;                /* obliterate the magic, but leave the rest */
                write_drive(drive, (void *) vhdr, VINUMHEADERLEN, VINUM_LABEL_OFFSET);
            }
            Free(vhdr);
        }
        free_drive(drive);                                  /* close it and free resources */
        save_config();                                      /* and save the updated configuration */
    }
}

/*
 * Transfer drive data.  Usually called from one of these defines;
 * #define read_drive(a, b, c, d) driveio (a, b, c, d, BUF_CMD_READ)
 * #define write_drive(a, b, c, d) driveio (a, b, c, d, BUF_CMD_WRITE)
 *
 * length and offset are in bytes, but must be multiples of sector
 * size.  The function *does not check* for this condition, and
 * truncates ruthlessly.
 * Return error number
 */
int
driveio(struct drive *drive, char *buf, size_t length, off_t offset, buf_cmd_t cmd)
{
    int error;
    struct buf *bp;
    caddr_t saveaddr;

    error = 0;                                              /* to keep the compiler happy */
    while (length) {                                        /* divide into small enough blocks */
        int len = umin(length, MAXBSIZE);                   /* maximum block device transfer is MAXBSIZE */

        bp = getpbuf_kva(NULL);                             /* get a buffer header */
        KKASSERT(len <= bp->b_bufsize);
        bp->b_cmd = cmd;
        bp->b_bio1.bio_offset = offset;                     /* disk offset */
        bp->b_bio1.bio_done = biodone_sync;
        bp->b_bio1.bio_flags |= BIO_SYNC;
        saveaddr = bp->b_data;
        bp->b_data = buf;
        bp->b_bcount = len;
        vn_strategy(drive->vp, &bp->b_bio1);
        error = biowait(&bp->b_bio1, (cmd == BUF_CMD_READ ? "drvrd" : "drvwr"));
        bp->b_data = saveaddr;
        bp->b_flags |= B_INVAL | B_AGE;
        bp->b_flags &= ~B_ERROR;
        relpbuf(bp, NULL);
        if (error)
            break;
        length -= len;                                      /* update pointers */
        buf += len;
        offset += len;
    }
    return error;
}

/*
 * Check a drive for a vinum header.  If found,
 * update the drive information.  We come here
 * with a partially populated drive structure
 * which includes the device name.
 *
 * Return information on what we found.
 *
 * This function is called from two places: check_drive,
 * which wants to find out whether the drive is a
 * Vinum drive, and config_drive, which asserts that
 * it is a vinum drive.  In the first case, we don't
 * print error messages (verbose==0), in the second
 * we do (verbose==1).
 */
enum drive_label_info
read_drive_label(struct drive *drive, int verbose)
{
    int error;
    int result;
    struct vinum_hdr *vhdr;

    error = init_drive(drive, verbose);                     /* find the drive */
    if (error)                                              /* find the drive */
        return DL_CANT_OPEN;                                /* not ours */

    vhdr = (struct vinum_hdr *) Malloc(VINUMHEADERLEN);     /* allocate buffers */
    CHECKALLOC(vhdr, "Can't allocate memory");

    drive->state = drive_up;                                /* be optimistic */
    error = read_drive(drive, (void *) vhdr, VINUMHEADERLEN, VINUM_LABEL_OFFSET);
    if (vhdr->magic == VINUM_MAGIC) {                       /* ours! */
        if (drive->label.name[0]                            /* we have a name for this drive */
        &&(strcmp(drive->label.name, vhdr->label.name))) {  /* but it doesn't match the real name */
            drive->lasterror = EINVAL;
            result = DL_WRONG_DRIVE;                        /* it's the wrong drive */
            drive->state = drive_unallocated;               /* put it back, it's not ours */
        } else
            result = DL_OURS;
        /*
         * We copy the drive anyway so that we have
         * the correct name in the drive info.  This
         * may not be the name specified
         */
        drive->label = vhdr->label;                         /* put in the label information */
    } else if (vhdr->magic == VINUM_NOMAGIC)                /* was ours, but we gave it away */
        result = DL_DELETED_LABEL;                          /* and return the info */
    else
        result = DL_NOT_OURS;                               /* we could have it, but we don't yet */
    Free(vhdr);                                             /* that's all. */
    return result;
}

/*
 * Check a drive for a vinum header.  If found,
 * read configuration information from the drive and
 * incorporate the data into the configuration.
 *
 * Return drive number.
 */
struct drive *
check_drive(char *devicename)
{
    int driveno;
    int i;
    struct drive *drive;

    driveno = find_drive_by_dev(devicename, 1);             /* if entry doesn't exist, create it */
    drive = &vinum_conf.drive[driveno];                     /* and get a pointer */

    if (read_drive_label(drive, 0) == DL_OURS) {            /* one of ours */
        for (i = 0; i < vinum_conf.drives_allocated; i++) { /* see if the name already exists */
            if ((i != driveno)                              /* not this drive */
            &&(DRIVE[i].state != drive_unallocated)         /* and it's allocated */
            &&(strcmp(DRIVE[i].label.name,
                        DRIVE[driveno].label.name) == 0)) { /* and it has the same name */
                struct drive *mydrive = &DRIVE[i];

                if (mydrive->devicename[0] == '/') {        /* we know a device name for it */
                    /*
                     * set an error, but don't take the
                     * drive down: that would cause unneeded
                     * error messages.
                     */
                    drive->lasterror = EEXIST;
                    break;
                } else {                                    /* it's just a place holder, */
                    int sdno;

                    for (sdno = 0; sdno < vinum_conf.subdisks_allocated; sdno++) { /* look at each subdisk */
                        if ((SD[sdno].driveno == i)         /* it's pointing to this one, */
                        &&(SD[sdno].state != sd_unallocated)) { /* and it's a real subdisk */
                            SD[sdno].driveno = drive->driveno; /* point to the one we found */
                            update_sd_state(sdno);          /* and update its state */
                        }
                    }
                    bzero(mydrive, sizeof(struct drive));   /* don't deallocate it, just remove it */
                }
            }
        }
    } else {
        if (drive->lasterror == 0)
            drive->lasterror = ENODEV;
        close_drive(drive);
        drive->state = drive_down;
    }
    return drive;
}

static char *
sappend(char *txt, char *s)
{
    while ((*s++ = *txt++) != 0);
    return s - 1;
}

void
format_config(char *config, int len)
{
    int i;
    int j;
    char *s = config;
    char *configend = &config[len];

    bzero(config, len);

    /* First write the volume configuration */
    for (i = 0; i < vinum_conf.volumes_allocated; i++) {
        struct volume *vol;

        vol = &vinum_conf.volume[i];
        if ((vol->state > volume_uninit)
            && (vol->name[0] != '\0')) {                    /* paranoia */
            ksnprintf(s,
                configend - s,
                "volume %s state %s",
                vol->name,
                volume_state(vol->state));
            while (*s)
                s++;                                        /* find the end */
            if (vol->preferred_plex >= 0)                   /* preferences, */
                ksnprintf(s,
                    configend - s,
                    " readpol prefer %s",
                    vinum_conf.plex[vol->preferred_plex].name);
            while (*s)
                s++;                                        /* find the end */
            s = sappend("\n", s);
        }
    }

    /* Then the plex configuration */
    for (i = 0; i < vinum_conf.plexes_allocated; i++) {
        struct plex *plex;

        plex = &vinum_conf.plex[i];
        if ((plex->state > plex_referenced)
            && (plex->name[0] != '\0')) {                   /* paranoia */
            ksnprintf(s,
                configend - s,
                "plex name %s state %s org %s ",
                plex->name,
                plex_state(plex->state),
                plex_org(plex->organization));
            while (*s)
                s++;                                        /* find the end */
            if (isstriped(plex)) {
                ksnprintf(s,
                    configend - s,
                    "%ds ",
                    (int) plex->stripesize);
                while (*s)
                    s++;                                    /* find the end */
            }
            if (plex->volno >= 0)                           /* we have a volume */
                ksnprintf(s,
                    configend - s,
                    "vol %s ",
                    vinum_conf.volume[plex->volno].name);
            while (*s)
                s++;                                        /* find the end */
            for (j = 0; j < plex->subdisks; j++) {
                ksnprintf(s,
                    configend - s,
                    " sd %s",
                    vinum_conf.sd[plex->sdnos[j]].name);
            }
            s = sappend("\n", s);
        }
    }

    /* And finally the subdisk configuration */
    for (i = 0; i < vinum_conf.subdisks_allocated; i++) {
        struct sd *sd;
        char *drivename;

        sd = &SD[i];
        if ((sd->state != sd_referenced)
            && (sd->state != sd_unallocated)
            && (sd->name[0] != '\0')) {                     /* paranoia */
            drivename = vinum_conf.drive[sd->driveno].label.name;
            /*
             * XXX We've seen cases of dead subdisks
             * which don't have a drive.  If we let them
             * through here, the drive name is null, so
             * they get the drive named 'plex'.
             *
             * This is a breakage limiter, not a fix.
             */
            if (drivename[0] == '\0')
                drivename = "*invalid*";
            ksnprintf(s,
                configend - s,
                "sd name %s drive %s plex %s len %llus driveoffset %llus state %s",
                sd->name,
                drivename,
                vinum_conf.plex[sd->plexno].name,
                (unsigned long long) sd->sectors,
                (unsigned long long) sd->driveoffset,
                sd_state(sd->state));
            while (*s)
                s++;                                        /* find the end */
            if (sd->plexno >= 0)
                ksnprintf(s,
                    configend - s,
                    " plexoffset %llds",
                    (long long) sd->plexoffset);
            else
                ksnprintf(s, configend - s, " detached");
            while (*s)
                s++;                                        /* find the end */
            if (sd->flags & VF_RETRYERRORS) {
                ksnprintf(s, configend - s, " retryerrors");
                while (*s)
                    s++;                                    /* find the end */
            }
            ksnprintf(s, configend - s, " \n");
            while (*s)
                s++;                                        /* find the end */
        }
    }
    if (s > &config[len - 2])
        panic("vinum: configuration data overflow");
}

/*
 * issue a save config request to the daemon.  The actual work
 * is done in process context by daemon_save_config
 */
void
save_config(void)
{
    union daemoninfo di = { .nothing = 0 };

    queue_daemon_request(daemonrq_saveconfig, di);
}

/*
 * Write the configuration to all vinum slices.  This
 * is performed by the daemon only
 */
void
daemon_save_config(void)
{
    int error;
    int driveno;
    struct drive *drive;                                    /* point to current drive info */
    struct vinum_hdr *vhdr;                                 /* and as header */
    char *config;                                           /* point to config data */
    int wlabel_on;                                          /* to set writing label on/off */

    /* don't save the configuration while we're still working on it */
    if (vinum_conf.flags & VF_CONFIGURING)
        return;
    /* Build a volume header */
    vhdr = (struct vinum_hdr *) Malloc(VINUMHEADERLEN);     /* get space for the config data */
    CHECKALLOC(vhdr, "Can't allocate config data");
    vhdr->magic = VINUM_MAGIC;                              /* magic number */
    vhdr->config_length = MAXCONFIG;                        /* length of following config info */

    config = Malloc(MAXCONFIG);                             /* get space for the config data */
    CHECKALLOC(config, "Can't allocate config data");

    format_config(config, MAXCONFIG);
    error = 0;                                              /* no errors yet */
    for (driveno = 0; driveno < vinum_conf.drives_allocated; driveno++) {
        drive = &vinum_conf.drive[driveno];                 /* point to drive */
        if (drive->state > drive_referenced) {
            LOCKDRIVE(drive);                               /* don't let it change */

            /*
             * First, do some drive consistency checks.  Some
             * of these are kludges, others require a process
             * context and couldn't be done before
             */
            if ((drive->devicename[0] == '\0')
                || (drive->label.name[0] == '\0')) {
                unlockdrive(drive);
                free_drive(drive);                          /* get rid of it */
                break;
            }
            if (((drive->flags & VF_OPEN) == 0)             /* drive not open */
            &&(drive->state > drive_down)) {                /* and it thinks it's not down */
                unlockdrive(drive);
                set_drive_state(driveno, drive_down, setstate_force); /* tell it what's what */
                continue;
            }
            if ((drive->state == drive_down)                /* it's down */
            &&(drive->flags & VF_OPEN)) {                   /* but open, */
                unlockdrive(drive);
                close_drive(drive);                         /* close it */
            } else if (drive->state > drive_down) {
                getmicrotime(&drive->label.last_update);    /* time of last update is now */
                bcopy((char *) &drive->label,               /* and the label info from the drive structure */
                    (char *) &vhdr->label,
                    sizeof(vhdr->label));
                if ((drive->state != drive_unallocated)
                    && (drive->state != drive_referenced)) { /* and it's a real drive */
                    wlabel_on = 1;                          /* enable writing the label */
                    error = 0;
#if 1
                    error = VOP_IOCTL(drive->vp, DIOCWLABEL,
                                      (caddr_t)&wlabel_on, FREAD|FWRITE,
                                      proc0.p_ucred, NULL);
#endif
                    if (error == 0)
                        error = write_drive(drive, (char *) vhdr, VINUMHEADERLEN, VINUM_LABEL_OFFSET);
                    if (error == 0)
                        error = write_drive(drive, config, MAXCONFIG, VINUM_CONFIG_OFFSET); /* first config copy */
                    if (error == 0)
                        error = write_drive(drive, config, MAXCONFIG, VINUM_CONFIG_OFFSET + MAXCONFIG); /* second copy */
                    wlabel_on = 0;                          /* enable writing the label */
#if 1
                    if (error == 0) {
                        error = VOP_IOCTL(drive->vp, DIOCWLABEL,
                                          (caddr_t)&wlabel_on, FREAD|FWRITE,
                                          proc0.p_ucred, NULL);
                    }
#endif
                    unlockdrive(drive);
                    if (error) {
                        log(LOG_ERR,
                            "vinum: Can't write config to %s, error %d\n",
                            drive->devicename,
                            error);
                        set_drive_state(drive->driveno, drive_down, setstate_force);
                    }
                }
            } else                                          /* not worth looking at, */
                unlockdrive(drive);                         /* just unlock it again */
        }
    }
    Free(vhdr);
    Free(config);
}

/* Look at all disks on the system for vinum slices */
int
vinum_scandisk(char *devicename[], int drives)
{
    struct drive *volatile drive;
    volatile int driveno;
    volatile int gooddrives;                                /* number of usable drives found */
    int firsttime;                                          /* set if we have never configured before */
    int error;
    char *config_text;                                      /* read the config info from disk into here */
    char *volatile cptr;                                    /* pointer into config information */
    char *eptr;                                             /* end pointer into config information */
    char *config_line;                                      /* copy the config line to */
    volatile int status;
    int *volatile drivelist;                                /* list of drive indices */
#define DRIVENAMELEN 64
#define DRIVEPARTS   35                                     /* max partitions per drive, excluding c */
    char partname[DRIVENAMELEN];                            /* for creating partition names */

    status = 0;                                             /* success indication */
    vinum_conf.flags |= VF_READING_CONFIG;                  /* reading config from disk */

    gooddrives = 0;                                         /* number of usable drives found */
    firsttime = vinum_conf.drives_used == 0;                /* are we a virgin? */

    /* allocate a drive pointer list */
    drivelist = (int *) Malloc(drives * DRIVEPARTS * sizeof(int));
    CHECKALLOC(drivelist, "Can't allocate memory");
    error = setjmp(command_fail);                           /* come back here on error */
    if (error) {                                            /* longjmped out */
        return error;
    }

    /* Open all drives and find which was modified most recently */
    for (driveno = 0; driveno < drives; driveno++) {
        char part, has_part = 0;                            /* UNIX partition */
        int slice;
        int has_slice = -1;
        char *tmp;

        /*
         * If the device path contains a slice we do not try to tack on
         * another slice.  If the device path has a partition we only check
         * that partition.
         */
        if ((tmp = rindex(devicename[driveno], '/')) == NULL)
            tmp = devicename[driveno];
        else
                tmp++;
        ksscanf(tmp, "%*[a-z]%*d%*[s]%d%c", &has_slice, &has_part);

        for (slice = 0; slice < MAX_SLICES; slice++) {
            if (has_slice >= 0 && slice != has_slice)
                continue;

            for (part = 'a'; part < 'a' + MAXPARTITIONS; part++) {
                if (part == 'c')
                    continue;
                if (has_part && part != has_part)
                    continue;
                if (has_slice >= 0 && has_part)
                        strncpy(partname, devicename[driveno], DRIVENAMELEN);
                else if (has_slice >= 0)
                        ksnprintf(partname, DRIVENAMELEN,
                                "%s%c", devicename[driveno], part);
                else
                        ksnprintf(partname, DRIVENAMELEN,
                                "%ss%d%c", devicename[driveno], slice, part);
                drive = check_drive(partname);      /* try to open it */
                if ((drive->lasterror != 0)                 /* didn't work, */
                    ||(drive->state != drive_up))
                    free_drive(drive);              /* get rid of it */
                else if (drive->flags & VF_CONFIGURED)  /* already read this config, */
                    log(LOG_WARNING,
                        "vinum: already read config from %s\n", /* say so */
                        drive->label.name);
                else {
                    drivelist[gooddrives] = drive->driveno;     /* keep the drive index */
                    drive->flags &= ~VF_NEWBORN;            /* which is no longer newly born */
                    gooddrives++;
                }
            }
        }
    }

    if (gooddrives == 0) {
        if (firsttime)
            log(LOG_WARNING, "vinum: no drives found\n");
        else
            log(LOG_INFO, "vinum: no additional drives found\n");
        return ENOENT;
    }
    /*
     * We now have at least one drive
     * open.  Sort them in order of config time
     * and merge the config info with what we
     * have already.
     */
    kqsort(drivelist, gooddrives, sizeof(int), drivecmp);
    config_text = (char *) Malloc(MAXCONFIG * 2);           /* allocate buffers */
    CHECKALLOC(config_text, "Can't allocate memory");
    config_line = (char *) Malloc(MAXCONFIGLINE * 2);       /* allocate buffers */
    CHECKALLOC(config_line, "Can't allocate memory");
    for (driveno = 0; driveno < gooddrives; driveno++) {    /* now include the config */
        drive = &DRIVE[drivelist[driveno]];                 /* point to the drive */

        if (firsttime && (driveno == 0))                    /* we've never configured before, */
            log(LOG_INFO, "vinum: reading configuration from %s\n", drive->devicename);
        else
            log(LOG_INFO, "vinum: updating configuration from %s\n", drive->devicename);

        if (drive->state == drive_up)
            /* Read in both copies of the configuration information */
            error = read_drive(drive, config_text, MAXCONFIG * 2, VINUM_CONFIG_OFFSET);
        else {
            error = EIO;
            kprintf("vinum_scandisk: %s is %s\n", drive->devicename, drive_state(drive->state));
        }

        if (error != 0) {
            log(LOG_ERR, "vinum: Can't read device %s, error %d\n", drive->devicename, error);
            free_drive(drive);                              /* give it back */
            status = error;
        }
        /*
         * At this point, check that the two copies
         * are the same, and do something useful if
         * not.  In particular, consider which is
         * newer, and what this means for the
         * integrity of the data on the drive.
         */
        else {
            vinum_conf.drives_used++;                       /* another drive in use */
            /* Parse the configuration, and add it to the global configuration */
            for (cptr = config_text; *cptr != '\0';) {      /* love this style(9) */
                volatile int parse_status;                  /* return value from parse_config */

                for (eptr = config_line; (*cptr != '\n') && (*cptr != '\0');) /* until the end of the line */
                    *eptr++ = *cptr++;
                *eptr = '\0';                               /* and delimit */
                if (setjmp(command_fail) == 0) {            /* come back here on error and continue */
                    parse_status = parse_config(config_line, &keyword_set, 1); /* parse the config line */
                    if (parse_status < 0) {                 /* error in config */
                        /*
                           * This config should have been parsed in user
                           * space.  If we run into problems here, something
                           * serious is afoot.  Complain and let the user
                           * snarf the config to see what's wrong.
                         */
                        log(LOG_ERR,
                            "vinum: Config error on %s, aborting integration\n",
                            drive->devicename);
                        free_drive(drive);                  /* give it back */
                        status = EINVAL;
                    }
                }
                while (*cptr == '\n')
                    cptr++;                                 /* skip to next line */
            }
        }
        drive->flags |= VF_CONFIGURED;                      /* read this drive's configuration */
    }

    Free(config_line);
    Free(config_text);
    Free(drivelist);
    vinum_conf.flags &= ~VF_READING_CONFIG;                 /* no longer reading from disk */
    if (status != 0)
        kprintf("vinum: couldn't read configuration");
    else
        updateconfig(VF_READING_CONFIG);                    /* update from disk config */
    return status;
}

/*
 * Compare the modification dates of the drives, for qsort.
 * Return 1 if a < b, 0 if a == b, 01 if a > b: in other
 * words, sort backwards.
 */
static int
drivecmp(const void *va, const void *vb)
{
    const struct drive *a = &DRIVE[*(const int *) va];
    const struct drive *b = &DRIVE[*(const int *) vb];

    if ((a->label.last_update.tv_sec == b->label.last_update.tv_sec)
        && (a->label.last_update.tv_usec == b->label.last_update.tv_usec))
        return 0;
    else if ((a->label.last_update.tv_sec > b->label.last_update.tv_sec)
            || ((a->label.last_update.tv_sec == b->label.last_update.tv_sec)
            && (a->label.last_update.tv_usec > b->label.last_update.tv_usec)))
        return -1;
    else
        return 1;
}