Merge commit 'ea01a15a654b9e1c7b37d958f4d1911882ed7781'

[unleashed.git] / kernel / fs / hsfs / hsfs_vfsops.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 (c) 1990, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2011 Bayard G. Bell. All rights reserved.
 * Copyright 2013 Joyent, Inc. All rights reserved.
 * Copyright (c) 2017 by Delphix. All rights reserved.
 */

/*
 * VFS operations for High Sierra filesystem
 */

#include <sys/types.h>
#include <sys/isa_defs.h>
#include <sys/t_lock.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysmacros.h>
#include <sys/kmem.h>
#include <sys/signal.h>
#include <sys/user.h>
#include <sys/proc.h>
#include <sys/disp.h>
#include <sys/buf.h>
#include <sys/pathname.h>
#include <sys/vfs.h>
#include <sys/vnode.h>
#include <sys/file.h>
#include <sys/uio.h>
#include <sys/conf.h>
#include <sys/policy.h>

#include <vm/page.h>

#include <sys/fs/snode.h>
#include <sys/fs/hsfs_spec.h>
#include <sys/fs/hsfs_isospec.h>
#include <sys/fs/hsfs_node.h>
#include <sys/fs/hsfs_impl.h>
#include <sys/fs/hsfs_susp.h>
#include <sys/fs/hsfs_rrip.h>

#include <sys/statvfs.h>
#include <sys/mount.h>
#include <sys/mntent.h>
#include <sys/swap.h>
#include <sys/errno.h>
#include <sys/debug.h>
#include "sys/fs_subr.h"
#include <sys/cmn_err.h>
#include <sys/bootconf.h>

#include <sys/sdt.h>

/*
 * These are needed for the CDROMREADOFFSET Code
 */
#include <sys/cdio.h>
#include <sys/sunddi.h>

#define HSFS_CLKSET

#include <sys/modctl.h>

/*
 * Options for mount.
 */
#define HOPT_MAPLCASE   "maplcase"
#define HOPT_NOMAPLCASE "nomaplcase"
#define HOPT_NOTRAILDOT "notraildot"
#define HOPT_TRAILDOT   "traildot"
#define HOPT_NRR        "nrr"
#define HOPT_RR         "rr"
#define HOPT_JOLIET     "joliet"
#define HOPT_NOJOLIET   "nojoliet"
#define HOPT_JOLIETLONG "jolietlong"
#define HOPT_VERS2      "vers2"
#define HOPT_NOVERS2    "novers2"
#define HOPT_RO         MNTOPT_RO

static char *mapl_cancel[] = { HOPT_NOMAPLCASE, NULL };
static char *nomapl_cancel[] = { HOPT_MAPLCASE, NULL };
static char *ro_cancel[] = { MNTOPT_RW, NULL };
static char *rr_cancel[] = { HOPT_NRR, NULL };
static char *nrr_cancel[] = { HOPT_RR, NULL };
static char *joliet_cancel[] = { HOPT_NOJOLIET, NULL };
static char *nojoliet_cancel[] = { HOPT_JOLIET, NULL };
static char *vers2_cancel[] = { HOPT_NOVERS2, NULL };
static char *novers2_cancel[] = { HOPT_VERS2, NULL };
static char *trail_cancel[] = { HOPT_NOTRAILDOT, NULL };
static char *notrail_cancel[] = { HOPT_TRAILDOT, NULL };

static mntopt_t hsfs_options[] = {
        { HOPT_MAPLCASE, mapl_cancel, NULL, MO_DEFAULT, NULL },
        { HOPT_NOMAPLCASE, nomapl_cancel, NULL, 0, NULL },
        { HOPT_RO, ro_cancel, NULL, MO_DEFAULT, NULL },
        { HOPT_RR, rr_cancel, NULL, MO_DEFAULT, NULL },
        { HOPT_NRR, nrr_cancel, NULL, 0, NULL },
        { HOPT_JOLIET, joliet_cancel, NULL, 0, NULL },
        { HOPT_NOJOLIET, nojoliet_cancel, NULL, 0, NULL },
        { HOPT_JOLIETLONG, NULL, NULL, 0, NULL },
        { HOPT_VERS2, vers2_cancel, NULL, 0, NULL },
        { HOPT_NOVERS2, novers2_cancel, NULL, 0, NULL },
        { HOPT_TRAILDOT, trail_cancel, NULL, MO_DEFAULT, NULL },
        { HOPT_NOTRAILDOT, notrail_cancel, NULL, 0, NULL },
        { "sector", NULL, "0", MO_HASVALUE, NULL},
};

static mntopts_t hsfs_proto_opttbl = {
        sizeof (hsfs_options) / sizeof (mntopt_t),
        hsfs_options
};

/*
 * Indicates whether to enable the I/O scheduling and readahead logic
 * 1 - Enable, 0 - Do not Enable.
 * Debugging purposes.
 */
int do_schedio = 1;
static int hsfsfstype;
static int hsfsinit(int, char *);

static vfsdef_t vfw = {
        VFSDEF_VERSION,
        "hsfs",
        hsfsinit,
        /* We don't suppport remounting */
        VSW_HASPROTO|VSW_STATS|VSW_CANLOFI|VSW_MOUNTDEV,
        &hsfs_proto_opttbl
};

static struct modlfs modlfs = {
        &mod_fsops, "filesystem for HSFS", &vfw
};

static struct modlinkage modlinkage = {
        MODREV_1, (void *)&modlfs, NULL
};

extern void hsched_init_caches(void);
extern void hsched_fini_caches(void);


int
_init(void)
{
        return (mod_install(&modlinkage));
}

int
_fini(void)
{
        int     error;

        error = mod_remove(&modlinkage);

        DTRACE_PROBE1(mod_remove, int, error);

        if (error)
                return (error);

        mutex_destroy(&hs_mounttab_lock);

        /*
         * Tear down the operations vectors
         */
        (void) vfs_freevfsops_by_type(hsfsfstype);

        hs_fini_hsnode_cache();
        hsched_fini_caches();
        return (0);
}

int
_info(struct modinfo *modinfop)
{
        return (mod_info(&modlinkage, modinfop));
}

#define BDEVFLAG(dev)   ((devopsp[getmajor(dev)])->devo_cb_ops->cb_flag)

kmutex_t hs_mounttab_lock;
struct hsfs *hs_mounttab = NULL;

/* default mode, uid, gid */
mode_t hsfs_default_mode = 0555;
uid_t hsfs_default_uid = 0;
gid_t hsfs_default_gid = 3;

extern void hsched_init(struct hsfs *fsp, int fsid,
                                        struct modlinkage *modlinkage);
extern void hsched_fini(struct hsfs_queue *hqueue);
extern void hsfs_init_kstats(struct hsfs *fsp, int fsid);
extern void hsfs_fini_kstats(struct hsfs *fsp);

static int hsfs_mount(struct vfs *vfsp, struct vnode *mvp,
        struct mounta *uap, struct cred *cr);
static int hsfs_unmount(struct vfs *vfsp, int, struct cred *cr);
static int hsfs_root(struct vfs *vfsp, struct vnode **vpp);
static int hsfs_statvfs(struct vfs *vfsp, struct statvfs64 *sbp);
static int hsfs_vget(struct vfs *vfsp, struct vnode **vpp, struct fid *fidp);
static int hsfs_mountroot(struct vfs *, enum whymountroot);

static int hs_mountfs(struct vfs *vfsp, dev_t dev, char *path,
        mode_t mode, int flags, struct cred *cr, int isroot);
static int hs_getrootvp(struct vfs *vfsp, struct hsfs *fsp, size_t pathsize);
static int hs_findhsvol(struct hsfs *fsp, struct vnode *vp,
        struct hs_volume *hvp);
static int hs_parsehsvol(struct hsfs *fsp, uchar_t *volp,
        struct hs_volume *hvp);
static int hs_findisovol(struct hsfs *fsp, struct vnode *vp,
        struct hs_volume *hvp,
        struct hs_volume *svp,
        struct hs_volume *jvp);
static int hs_joliet_level(uchar_t *volp);
static int hs_parseisovol(struct hsfs *fsp, uchar_t *volp,
        struct hs_volume *hvp);
static void hs_copylabel(struct hs_volume *, unsigned char *, int);
static int hs_getmdev(struct vfs *, char *fspec, int flags, dev_t *pdev,
        mode_t *mode, cred_t *cr);
static int hs_findvoldesc(dev_t rdev, int desc_sec);

static const struct vfsops hsfs_vfsops = {
        .vfs_mount = hsfs_mount,
        .vfs_unmount = hsfs_unmount,
        .vfs_root = hsfs_root,
        .vfs_statvfs = hsfs_statvfs,
        .vfs_vget = hsfs_vget,
        .vfs_mountroot = hsfs_mountroot,
};

static int
hsfsinit(int fstype, char *name)
{
        int error;

        error = vfs_setfsops(fstype, &hsfs_vfsops);
        if (error != 0) {
                cmn_err(CE_WARN, "hsfsinit: bad fstyp");
                return (error);
        }

        hsfsfstype = fstype;
        mutex_init(&hs_mounttab_lock, NULL, MUTEX_DEFAULT, NULL);
        hs_init_hsnode_cache();
        hsched_init_caches();
        return (0);
}

/*ARGSUSED*/
static int
hsfs_mount(struct vfs *vfsp, struct vnode *mvp,
    struct mounta *uap, struct cred *cr)
{
        int             vnode_busy;
        dev_t           dev;
        struct pathname dpn;
        int             error;
        mode_t          mode;
        int             flags;  /* this will hold the mount specific data */

        if ((error = secpolicy_fs_mount(cr, mvp, vfsp)) != 0)
                return (error);

        if (mvp->v_type != VDIR)
                return (ENOTDIR);

        /* mount option must be read only, else mount will be rejected */
        if (!(uap->flags & MS_RDONLY))
                return (EROFS);

        /*
         * We already told the framework that we don't support remounting.
         */
        ASSERT(!(uap->flags & MS_REMOUNT));

        mutex_enter(&mvp->v_lock);
        vnode_busy = (mvp->v_count != 1) || (mvp->v_flag & VROOT);
        mutex_exit(&mvp->v_lock);

        if ((uap->flags & MS_OVERLAY) == 0 && vnode_busy) {
                return (EBUSY);
        }

        /*
         * Check for the options that actually affect things
         * at our level.
         */
        flags = 0;
        if (vfs_optionisset(vfsp, HOPT_NOMAPLCASE, NULL))
                flags |= HSFSMNT_NOMAPLCASE;
        if (vfs_optionisset(vfsp, HOPT_NOTRAILDOT, NULL))
                flags |= HSFSMNT_NOTRAILDOT;
        if (vfs_optionisset(vfsp, HOPT_NRR, NULL))
                flags |= HSFSMNT_NORRIP;
        if (vfs_optionisset(vfsp, HOPT_NOJOLIET, NULL))
                flags |= HSFSMNT_NOJOLIET;
        if (vfs_optionisset(vfsp, HOPT_JOLIETLONG, NULL))
                flags |= HSFSMNT_JOLIETLONG;
        if (vfs_optionisset(vfsp, HOPT_NOVERS2, NULL))
                flags |= HSFSMNT_NOVERS2;

        error = pn_get(uap->dir, (uap->flags & MS_SYSSPACE) ?
            UIO_SYSSPACE : UIO_USERSPACE, &dpn);
        if (error)
                return (error);

        error = hs_getmdev(vfsp, uap->spec, uap->flags, &dev, &mode, cr);
        if (error != 0) {
                pn_free(&dpn);
                return (error);
        }

        /*
         * If the device is a tape, return error
         */
        if ((BDEVFLAG(dev) & D_TAPE) == D_TAPE)  {
                pn_free(&dpn);
                return (ENOTBLK);
        }

        /*
         * Mount the filesystem.
         */
        error = hs_mountfs(vfsp, dev, dpn.pn_path, mode, flags, cr, 0);
        pn_free(&dpn);
        return (error);
}

/*ARGSUSED*/
static int
hsfs_unmount(
        struct vfs *vfsp,
        int flag,
        struct cred *cr)
{
        struct hsfs **tspp;
        struct hsfs *fsp;

        if (secpolicy_fs_unmount(cr, vfsp) != 0)
                return (EPERM);

        /*
         * forced unmount is not supported by this file system
         * and thus, ENOTSUP is being returned.
         */
        if (flag & MS_FORCE)
                return (ENOTSUP);

        fsp = VFS_TO_HSFS(vfsp);

        if (fsp->hsfs_rootvp->v_count != 1)
                return (EBUSY);

        /* destroy all old pages and hsnodes for this vfs */
        if (hs_synchash(vfsp))
                return (EBUSY);

        mutex_enter(&hs_mounttab_lock);
        for (tspp = &hs_mounttab; *tspp != NULL; tspp = &(*tspp)->hsfs_next) {
                if (*tspp == fsp)
                        break;
        }
        if (*tspp == NULL) {
                mutex_exit(&hs_mounttab_lock);
                panic("hsfs_unmount: vfs not mounted?");
                /*NOTREACHED*/
        }

        *tspp = fsp->hsfs_next;

        mutex_exit(&hs_mounttab_lock);

        hsfs_fini_kstats(fsp);
        (void) fop_close(fsp->hsfs_devvp, FREAD, 1, 0, cr, NULL);
        VN_RELE(fsp->hsfs_devvp);
        /* free path table space */
        if (fsp->hsfs_ptbl != NULL)
                kmem_free(fsp->hsfs_ptbl, (size_t)fsp->hsfs_vol.ptbl_len);
        /* free path table index table */
        if (fsp->hsfs_ptbl_idx != NULL)
                kmem_free(fsp->hsfs_ptbl_idx, (size_t)
                    (fsp->hsfs_ptbl_idx_size * sizeof (struct ptable_idx)));

        /* free "mounted on" pathame */
        if (fsp->hsfs_fsmnt != NULL)
                kmem_free(fsp->hsfs_fsmnt, strlen(fsp->hsfs_fsmnt) + 1);

        hsched_fini(fsp->hqueue);
        kmem_free(fsp->hqueue, sizeof (struct hsfs_queue));

        mutex_destroy(&fsp->hsfs_free_lock);
        rw_destroy(&fsp->hsfs_hash_lock);

        kmem_free(fsp, sizeof (*fsp));
        return (0);
}

/*ARGSUSED*/
static int
hsfs_root(struct vfs *vfsp, struct vnode **vpp)
{
        *vpp = (VFS_TO_HSFS(vfsp))->hsfs_rootvp;
        VN_HOLD(*vpp);
        return (0);
}

/*ARGSUSED*/
static int
hsfs_statvfs(struct vfs *vfsp, struct statvfs64 *sbp)
{
        struct hsfs *fsp;
        dev32_t d32;

        fsp = VFS_TO_HSFS(vfsp);
        if (fsp->hsfs_magic != HSFS_MAGIC)
                return (EINVAL);
        bzero(sbp, sizeof (*sbp));
        sbp->f_bsize = vfsp->vfs_bsize;
        sbp->f_frsize = sbp->f_bsize; /* no fragment, same as block size */
        sbp->f_blocks = (fsblkcnt64_t)fsp->hsfs_vol.vol_size;

        sbp->f_bfree = (fsblkcnt64_t)0;
        sbp->f_bavail = (fsblkcnt64_t)0;
        sbp->f_files = (fsfilcnt64_t)-1;
        sbp->f_ffree = (fsfilcnt64_t)0;
        sbp->f_favail = (fsfilcnt64_t)0;
        (void) cmpldev(&d32, vfsp->vfs_dev);
        sbp->f_fsid = d32;
        (void) strcpy(sbp->f_basetype, vfssw[vfsp->vfs_fstype].vsw_name);
        sbp->f_flag = vf_to_stf(vfsp->vfs_flag);
        sbp->f_namemax = fsp->hsfs_namemax;
        (void) strcpy(sbp->f_fstr, fsp->hsfs_vol.vol_id);

        return (0);
}

/*
 * Previously nodeid was declared as uint32_t. This has been changed
 * to conform better with the ISO9660 standard. The standard states that
 * a LBN can be a 32 bit number, as the MAKE_NODEID macro shifts this
 * LBN 11 places left (LBN_TO_BYTE) and then shifts the result 5 right
 * (divide by 32) we are left with the potential of an overflow if
 * confined to a 32 bit value.
 */

static int
hsfs_vget(struct vfs *vfsp, struct vnode **vpp, struct fid *fidp)
{
        struct hsfid *fid;
        struct hsfs *fsp;
        ino64_t nodeid;
        int error;

        fsp = (struct hsfs *)VFS_TO_HSFS(vfsp);
        fid = (struct hsfid *)fidp;

        /*
         * Look for vnode on hashlist.
         * If found, it's now active and the refcnt was incremented.
         */

        rw_enter(&fsp->hsfs_hash_lock, RW_READER);

        nodeid = fid->hf_ino;

        if ((*vpp = hs_findhash(nodeid, fid->hf_dir_lbn,
            (uint_t)fid->hf_dir_off, vfsp)) == NULL) {
                /*
                 * Not in cache, so we need to remake it.
                 * hs_remakenode() will read the directory entry
                 * and then check again to see if anyone else has
                 * put it in the cache.
                 */
                rw_exit(&fsp->hsfs_hash_lock);
                error = hs_remakenode(fid->hf_dir_lbn, (uint_t)fid->hf_dir_off,
                    vfsp, vpp);
                return (error);
        }
        rw_exit(&fsp->hsfs_hash_lock);
        return (0);
}


#define CHECKSUM_SIZE                           (64 * 1024)

/*
 * Compute a CD-ROM fsid by checksumming the first 64K of data on the CD
 * We use the 'fsp' argument to determine the location of the root
 * directory entry, and we start reading from there.
 */
static int
compute_cdrom_id(struct hsfs *fsp, vnode_t *devvp)
{
        uint_t          secno;
        struct hs_volume *hsvp = &fsp->hsfs_vol;
        struct buf      *bp;
        int             error;
        int             fsid;

        secno = hsvp->root_dir.ext_lbn >> hsvp->lbn_secshift;
        bp = bread(devvp->v_rdev, secno * 4, CHECKSUM_SIZE);
        error = geterror(bp);

        /*
         * An error on read or a partial read means we asked
         * for a nonexistant/corrupted piece of the device
         * (including past-the-end of the media). Don't
         * try to use the checksumming method then.
         */
        if (!error && bp->b_bcount == CHECKSUM_SIZE) {
                int *ibuf = (int *)bp->b_un.b_addr;
                int i;

                fsid = 0;

                for (i = 0; i < CHECKSUM_SIZE / sizeof (int); i++)
                        fsid ^= ibuf[ i ];
        } else {
                /*
                 * Fallback - use creation date
                 */
                fsid = hsvp->cre_date.tv_sec;
        }

        brelse(bp);

        return (fsid);
}


/*ARGSUSED*/
static int
hs_mountfs(
        struct vfs      *vfsp,
        dev_t           dev,
        char            *path,
        mode_t          mode,
        int             mount_flags,
        struct cred     *cr,
        int             isroot)
{
        struct vnode    *devvp;
        struct hsfs     *tsp;
        struct hsfs     *fsp = NULL;
        struct vattr    vap;
        struct hsnode   *hp;
        int             error;
        struct timeval  tv;
        int             fsid;
        int             use_rrip;
        int             use_vers2;
        int             use_joliet;
        int             has_rrip = 0;
        int             has_vers2 = 0;
        int             has_joliet = 0;
        int             force_rrip_off;
        int             force_vers2_off;
        int             force_joliet_off;
        size_t          pathbufsz = strlen(path) + 1;
        int             redo_rootvp;

        struct hs_volume *svp = NULL;   /* Supplemental VD for ISO-9660:1999 */
        struct hs_volume *jvp = NULL;   /* Joliet VD */

        /*
         * The rules for which extension will be used are:
         * 1. No specific mount options given:
         *      - use rrip if available
         *      - use ISO9660:1999 if available
         *      - use joliet if available.
         * 2. rrip/ISO9660:1999/joliet explicitly disabled via mount option:
         *      - use next "lower" extension
         * 3. joliet/ISO9660:1999/rrip explicitly requested via mount option:
         *      - disable rrip support even if available
         *      - disable IOS9660:1999 support even if available
         *
         * We need to adjust these flags as we discover the extensions
         * present. See below. These are just the starting values.
         */
        use_rrip = (mount_flags & HSFSMNT_NORRIP) == 0;
        use_vers2 = (mount_flags & HSFSMNT_NOVERS2) == 0;
        use_joliet = (mount_flags & HSFSMNT_NOJOLIET) == 0;

        /*
         * Open the device
         */
        devvp = makespecvp(dev, VBLK);
        ASSERT(devvp != 0);

        /*
         * Open the target device (file) for read only.
         */
        if (error = fop_open(&devvp, FREAD, cr, NULL)) {
                VN_RELE(devvp);
                return (error);
        }

        /*
         * Refuse to go any further if this
         * device is being used for swapping
         */
        if (IS_SWAPVP(common_specvp(devvp))) {
                error = EBUSY;
                goto cleanup;
        }

        vap.va_mask = AT_SIZE;
        if ((error = fop_getattr(devvp, &vap, ATTR_COMM, cr, NULL)) != 0) {
                cmn_err(CE_NOTE, "Cannot get attributes of the CD-ROM driver");
                goto cleanup;
        }

        /*
         * Make sure we have a nonzero size partition.
         * The current version of the SD driver will *not* fail the open
         * of such a partition so we have to check for it here.
         */
        if (vap.va_size == 0) {
                error = ENXIO;
                goto cleanup;
        }

        /*
         * Init a new hsfs structure.
         */
        fsp = kmem_zalloc(sizeof (*fsp), KM_SLEEP);
        svp = kmem_zalloc(sizeof (*svp), KM_SLEEP);
        jvp = kmem_zalloc(sizeof (*jvp), KM_SLEEP);

        /* hardwire perms, uid, gid */
        fsp->hsfs_vol.vol_uid = hsfs_default_uid;
        fsp->hsfs_vol.vol_gid =  hsfs_default_gid;
        fsp->hsfs_vol.vol_prot = hsfs_default_mode;
        svp->vol_uid = hsfs_default_uid;
        svp->vol_gid =  hsfs_default_gid;
        svp->vol_prot = hsfs_default_mode;
        jvp->vol_uid = hsfs_default_uid;
        jvp->vol_gid =  hsfs_default_gid;
        jvp->vol_prot = hsfs_default_mode;

        /*
         * Look for a Standard File Structure Volume Descriptor,
         * of which there must be at least one.
         * If found, check for volume size consistency.
         *
         * If svp->lbn_size is != 0, we did find a ISO-9660:1999 SVD
         * If jvp->lbn_size is != 0, we did find a Joliet SVD.
         */
        fsp->hsfs_namemax = ISO_FILE_NAMELEN;
        fsp->hsfs_namelen = ISO_FILE_NAMELEN;
        error = hs_findisovol(fsp, devvp, &fsp->hsfs_vol, svp, jvp);
        if (error == EINVAL) /* no iso 9660 - try high sierra ... */
                error = hs_findhsvol(fsp, devvp, &fsp->hsfs_vol);

        if (error)
                goto cleanup;

        DTRACE_PROBE4(findvol,
            struct hsfs *, fsp,
            struct hs_volume *, &fsp->hsfs_vol,
            struct hs_volume *, svp,
            struct hs_volume *, jvp);

        /*
         * Generate a file system ID from the CD-ROM,
         * and check it for uniqueness.
         *
         * What we are aiming for is some chance of integrity
         * across disk change.  That is, if a client has an fhandle,
         * it will be valid as long as the same disk is mounted.
         */
        fsid = compute_cdrom_id(fsp, devvp);

        mutex_enter(&hs_mounttab_lock);

        if (fsid == 0 || fsid == -1) {
                uniqtime(&tv);
                fsid = tv.tv_sec;
        } else  /* make sure that the fsid is unique */
                for (tsp = hs_mounttab; tsp != NULL; tsp = tsp->hsfs_next) {
                        if (fsid == tsp->hsfs_vfs->vfs_fsid.val[0]) {
                                uniqtime(&tv);
                                fsid = tv.tv_sec;
                                break;
                        }
                }

        fsp->hsfs_next = hs_mounttab;
        hs_mounttab = fsp;

        fsp->hsfs_devvp = devvp;
        fsp->hsfs_vfs = vfsp;
        fsp->hsfs_fsmnt = kmem_alloc(pathbufsz, KM_SLEEP);
        (void) strlcpy(fsp->hsfs_fsmnt, path, pathbufsz);

        mutex_init(&fsp->hsfs_free_lock, NULL, MUTEX_DEFAULT, NULL);
        rw_init(&fsp->hsfs_hash_lock, NULL, RW_DEFAULT, NULL);

        vfsp->vfs_data = (caddr_t)fsp;
        vfsp->vfs_dev = dev;
        vfsp->vfs_fstype = hsfsfstype;
        vfsp->vfs_bsize = fsp->hsfs_vol.lbn_size; /* %% */
        vfsp->vfs_fsid.val[0] = fsid;
        vfsp->vfs_fsid.val[1] =  hsfsfstype;

        if (!hs_getrootvp(vfsp, fsp, pathbufsz)) {
                DTRACE_PROBE1(rootvp__failed, struct hsfs *, fsp);
                error = EINVAL;
                goto cleanup;
        }
        DTRACE_PROBE1(rootvp, struct hsfs *, fsp);

        /*
         * Attempt to discover a RR extension.
         */
        if (use_rrip) {
                hp = VTOH(fsp->hsfs_rootvp);
                hs_check_root_dirent(fsp->hsfs_rootvp, &(hp->hs_dirent));
        }

        has_rrip = IS_RRIP_IMPLEMENTED(fsp);
        has_vers2 = (svp->lbn_size != 0);
        has_joliet = (jvp->lbn_size != 0);

        DTRACE_PROBE4(voltype__suggested, struct hsfs *, fsp,
            int, use_rrip, int, use_vers2, int, use_joliet);

        DTRACE_PROBE4(voltype__actual, struct hsfs *, fsp,
            int, has_rrip, int, has_vers2, int, has_joliet);

        DTRACE_PROBE4(findvol,
            struct hsfs *, fsp,
            struct hs_volume *, &fsp->hsfs_vol,
            struct hs_volume *, svp,
            struct hs_volume *, jvp);

        force_rrip_off = !use_rrip ||
            (vfs_optionisset(vfsp, HOPT_JOLIET, NULL) && has_joliet) ||
            (vfs_optionisset(vfsp, HOPT_VERS2, NULL) && has_vers2);

        force_vers2_off = !use_vers2 ||
            (vfs_optionisset(vfsp, HOPT_JOLIET, NULL) && has_joliet);

        force_joliet_off = !use_joliet;

        DTRACE_PROBE4(voltype__force_off, struct hsfs *, fsp,
            int, force_rrip_off, int, force_vers2_off, int, force_joliet_off);

        /*
         * At the moment, we have references of all three possible
         * extensions (RR, ISO9660:1999/v2 and Joliet) if present.
         *
         * The "active" volume descriptor is RRIP (or ISO9660:1988).
         * We now switch to the user-requested one.
         */
        redo_rootvp = 0;

        if (force_rrip_off || !has_rrip) {
                if (has_vers2 && !force_vers2_off) {
                        VN_RELE(fsp->hsfs_rootvp);
                        bcopy(svp, &fsp->hsfs_vol, sizeof (struct hs_volume));
                        fsp->hsfs_vol_type = HS_VOL_TYPE_ISO_V2;
                        vfsp->vfs_bsize = fsp->hsfs_vol.lbn_size;
                        redo_rootvp = 1;
                        has_joliet = 0;
                } else if (has_joliet && !force_joliet_off) {
                        VN_RELE(fsp->hsfs_rootvp);
                        bcopy(jvp, &fsp->hsfs_vol, sizeof (struct hs_volume));
                        fsp->hsfs_vol_type = HS_VOL_TYPE_JOLIET;
                        vfsp->vfs_bsize = fsp->hsfs_vol.lbn_size;
                        redo_rootvp = 1;
                        has_vers2 = 0;
                }
        }

        if (redo_rootvp) {
                /*
                 * Make sure not to use Rock Ridge.
                 */
                UNSET_IMPL_BIT(fsp, RRIP_BIT);
                UNSET_SUSP_BIT(fsp);
                has_rrip = 0;

                if (!hs_getrootvp(vfsp, fsp, pathbufsz)) {
                        DTRACE_PROBE1(rootvp__failed, struct hsfs *, fsp);
                        error = EINVAL;
                        goto cleanup;
                }
                DTRACE_PROBE1(rootvp, struct hsfs *, fsp);
        }
        if (IS_RRIP_IMPLEMENTED(fsp)) {
                has_vers2 = 0;
                has_joliet = 0;
        }
        if (force_vers2_off)
                has_vers2 = 0;
        if (force_joliet_off)
                has_joliet = 0;
        DTRACE_PROBE4(voltype__taken, struct hsfs *, fsp,
            int, has_rrip, int, has_vers2, int, has_joliet);

        /*
         * mark root node as VROOT
         */
        fsp->hsfs_rootvp->v_flag |= VROOT;

        /* Here we take care of some special case stuff for mountroot */
        if (isroot) {
                fsp->hsfs_rootvp->v_rdev = devvp->v_rdev;
                rootvp = fsp->hsfs_rootvp;
        }

        if (IS_RRIP_IMPLEMENTED(fsp)) {
                /*
                 * if RRIP, don't copy NOMAPLCASE or NOTRAILDOT to hsfs_flags
                 */
                mount_flags &= ~(HSFSMNT_NOMAPLCASE | HSFSMNT_NOTRAILDOT);

                fsp->hsfs_namemax = RRIP_FILE_NAMELEN;
                fsp->hsfs_namelen = RRIP_FILE_NAMELEN;

                ASSERT(vfs_optionisset(vfsp, HOPT_RR, NULL));
                vfs_clearmntopt(vfsp, HOPT_VERS2);
                vfs_clearmntopt(vfsp, HOPT_JOLIET);

        } else switch (fsp->hsfs_vol_type) {

        case HS_VOL_TYPE_HS:
        case HS_VOL_TYPE_ISO:
        default:
                /*
                 * if iso v1, don't allow trailing spaces in iso file names
                 */
                mount_flags |= HSFSMNT_NOTRAILSPACE;
                fsp->hsfs_namemax = ISO_NAMELEN_V2_MAX;
                fsp->hsfs_namelen = ISO_FILE_NAMELEN;
                vfs_clearmntopt(vfsp, HOPT_RR);
                vfs_clearmntopt(vfsp, HOPT_VERS2);
                vfs_clearmntopt(vfsp, HOPT_JOLIET);
                break;

        case HS_VOL_TYPE_ISO_V2:
                /*
                 * if iso v2, don't copy NOTRAILDOT to hsfs_flags
                 */
                mount_flags &= ~HSFSMNT_NOTRAILDOT;
                mount_flags |= HSFSMNT_NOMAPLCASE | HSFSMNT_NOVERSION;
                fsp->hsfs_namemax = ISO_NAMELEN_V2_MAX;
                fsp->hsfs_namelen = ISO_NAMELEN_V2;
                vfs_setmntopt(vfsp, HOPT_VERS2, NULL, 0);
                vfs_clearmntopt(vfsp, HOPT_RR);
                vfs_clearmntopt(vfsp, HOPT_JOLIET);
                break;

        case HS_VOL_TYPE_JOLIET:
                /*
                 * if Joliet, don't copy NOMAPLCASE or NOTRAILDOT to hsfs_flags
                 */
                mount_flags &= ~(HSFSMNT_NOMAPLCASE | HSFSMNT_NOTRAILDOT);
                mount_flags |= HSFSMNT_NOMAPLCASE;
                if (mount_flags & HSFSMNT_JOLIETLONG)
                        fsp->hsfs_namemax = JOLIET_NAMELEN_MAX*3; /* UTF-8 */
                else
                        fsp->hsfs_namemax = MAXNAMELEN-1;
                fsp->hsfs_namelen = JOLIET_NAMELEN*2;
                vfs_setmntopt(vfsp, HOPT_JOLIET, NULL, 0);
                vfs_clearmntopt(vfsp, HOPT_RR);
                vfs_clearmntopt(vfsp, HOPT_VERS2);
                break;
        }

        /*
         * Add the HSFSMNT_INODE pseudo mount flag to the current mount flags.
         */
        fsp->hsfs_flags = mount_flags | (fsp->hsfs_flags & HSFSMNT_INODE);

        /*
         * Setup I/O Scheduling structures
         */
        if (do_schedio) {
                fsp->hqueue = kmem_alloc(sizeof (struct hsfs_queue), KM_SLEEP);
                hsched_init(fsp, fsid, &modlinkage);
        }

        /*
         * Setup kstats
         */
        hsfs_init_kstats(fsp, fsid);

        DTRACE_PROBE1(mount__done, struct hsfs *, fsp);

        /*
         * set the magic word
         */
        fsp->hsfs_magic = HSFS_MAGIC;
        mutex_exit(&hs_mounttab_lock);

        kmem_free(svp, sizeof (*svp));
        kmem_free(jvp, sizeof (*jvp));

        return (0);

cleanup:
        (void) fop_close(devvp, FREAD, 1, 0, cr, NULL);
        VN_RELE(devvp);
        if (fsp)
                kmem_free(fsp, sizeof (*fsp));
        if (svp)
                kmem_free(svp, sizeof (*svp));
        if (jvp)
                kmem_free(jvp, sizeof (*jvp));
        return (error);
}

/*
 * Get the rootvp associated with fsp->hsfs_vol
 */
static int
hs_getrootvp(
        struct vfs      *vfsp,
        struct hsfs     *fsp,
        size_t          pathsize)
{
        struct hsnode   *hp;

        ASSERT(pathsize == strlen(fsp->hsfs_fsmnt) + 1);

        /*
         * If the root directory does not appear to be
         * valid, use what it points to as "." instead.
         * Some Defense Mapping Agency disks are non-conformant
         * in this way.
         */
        if (!hsfs_valid_dir(&fsp->hsfs_vol.root_dir)) {
                hs_log_bogus_disk_warning(fsp, HSFS_ERR_BAD_ROOT_DIR, 0);
                if (hs_remakenode(fsp->hsfs_vol.root_dir.ext_lbn,
                    0, vfsp, &fsp->hsfs_rootvp)) {
                        hs_mounttab = hs_mounttab->hsfs_next;
                        mutex_destroy(&fsp->hsfs_free_lock);
                        rw_destroy(&fsp->hsfs_hash_lock);
                        kmem_free(fsp->hsfs_fsmnt, pathsize);
                        mutex_exit(&hs_mounttab_lock);
                        return (0);
                }
        } else {
                fsp->hsfs_rootvp = hs_makenode(&fsp->hsfs_vol.root_dir,
                    fsp->hsfs_vol.root_dir.ext_lbn, 0, vfsp);
        }

        /* XXX - ignore the path table for now */
        fsp->hsfs_ptbl = NULL;
        hp = VTOH(fsp->hsfs_rootvp);
        hp->hs_ptbl_idx = NULL;

        return (1);
}

/*
 * hs_findhsvol()
 *
 * Locate the Standard File Structure Volume Descriptor and
 * parse it into an hs_volume structure.
 *
 * XXX - May someday want to look for Coded Character Set FSVD, too.
 */
static int
hs_findhsvol(struct hsfs *fsp, struct vnode *vp, struct hs_volume *hvp)
{
        struct buf *secbp;
        int i;
        int n;
        uchar_t *volp;
        int error;
        uint_t secno;

        secno = hs_findvoldesc(vp->v_rdev, HS_VOLDESC_SEC);
        secbp = bread(vp->v_rdev, secno * 4, HS_SECTOR_SIZE);
        error = geterror(secbp);

        if (error != 0) {
                cmn_err(CE_NOTE, "hs_findhsvol: bread: error=(%d)", error);
                brelse(secbp);
                return (error);
        }

        volp = (uchar_t *)secbp->b_un.b_addr;

        /*
         * To avoid that we read the whole medium in case that someone prepares
         * a malicious "fs image", we read at most 32 blocks.
         */
        for (n = 0; n < 32 &&
            HSV_DESC_TYPE(volp) != VD_EOV; n++) {
                for (i = 0; i < HSV_ID_STRLEN; i++)
                        if (HSV_STD_ID(volp)[i] != HSV_ID_STRING[i])
                                goto cantfind;
                if (HSV_STD_VER(volp) != HSV_ID_VER)
                        goto cantfind;
                switch (HSV_DESC_TYPE(volp)) {
                case VD_SFS:
                        /* Standard File Structure */
                        fsp->hsfs_vol_type = HS_VOL_TYPE_HS;
                        error = hs_parsehsvol(fsp, volp, hvp);
                        brelse(secbp);
                        return (error);

                case VD_CCFS:
                        /* Coded Character File Structure */
                case VD_BOOT:
                case VD_UNSPEC:
                case VD_EOV:
                        break;
                }
                brelse(secbp);
                ++secno;
                secbp = bread(vp->v_rdev, secno * 4, HS_SECTOR_SIZE);

                error = geterror(secbp);

                if (error != 0) {
                        cmn_err(CE_NOTE, "hs_findhsvol: bread: error=(%d)",
                            error);
                        brelse(secbp);
                        return (error);
                }

                volp = (uchar_t *)secbp->b_un.b_addr;
        }
cantfind:
        brelse(secbp);
        return (EINVAL);
}

/*
 * hs_parsehsvol
 *
 * Parse the Standard File Structure Volume Descriptor into
 * an hs_volume structure.  We can't just bcopy it into the
 * structure because of byte-ordering problems.
 *
 */
static int
hs_parsehsvol(struct hsfs *fsp, uchar_t *volp, struct hs_volume *hvp)
{
        hvp->vol_size = HSV_VOL_SIZE(volp);
        hvp->lbn_size = HSV_BLK_SIZE(volp);
        if (hvp->lbn_size == 0) {
                cmn_err(CE_NOTE, "hs_parsehsvol: logical block size in the "
                    "SFSVD is zero");
                return (EINVAL);
        }
        hvp->lbn_shift = ffs((long)hvp->lbn_size) - 1;
        hvp->lbn_secshift =
            ffs((long)howmany(HS_SECTOR_SIZE, (int)hvp->lbn_size)) - 1;
        hvp->lbn_maxoffset = hvp->lbn_size - 1;
        hs_parse_longdate(HSV_cre_date(volp), &hvp->cre_date);
        hs_parse_longdate(HSV_mod_date(volp), &hvp->mod_date);
        hvp->file_struct_ver = HSV_FILE_STRUCT_VER(volp);
        hvp->ptbl_len = HSV_PTBL_SIZE(volp);
        hvp->vol_set_size = (ushort_t)HSV_SET_SIZE(volp);
        hvp->vol_set_seq = (ushort_t)HSV_SET_SEQ(volp);
#if defined(_LITTLE_ENDIAN)
        hvp->ptbl_lbn = HSV_PTBL_MAN_LS(volp);
#else
        hvp->ptbl_lbn = HSV_PTBL_MAN_MS(volp);
#endif
        hs_copylabel(hvp, HSV_VOL_ID(volp), 0);

        /*
         * Make sure that lbn_size is a power of two and otherwise valid.
         */
        if (hvp->lbn_size & ~(1 << hvp->lbn_shift)) {
                cmn_err(CE_NOTE,
                    "hsfs: %d-byte logical block size not supported",
                    hvp->lbn_size);
                return (EINVAL);
        }
        return (hs_parsedir(fsp, HSV_ROOT_DIR(volp), &hvp->root_dir,
            NULL, NULL, HDE_ROOT_DIR_REC_SIZE));
}

/*
 * hs_findisovol()
 *
 * Locate the Primary Volume Descriptor
 * parse it into an hs_volume structure.
 *
 * XXX - Partition not yet done
 *
 * Except for fsp->hsfs_vol_type, no fsp member may be modified.
 * fsp->hsfs_vol is modified indirectly via the *hvp argument.
 */
static int
hs_findisovol(struct hsfs *fsp, struct vnode *vp,
    struct hs_volume *hvp,
    struct hs_volume *svp,
    struct hs_volume *jvp)
{
        struct buf *secbp;
        int i;
        int n;
        uchar_t *volp;
        int error;
        uint_t secno;
        int foundpvd = 0;
        int foundsvd = 0;
        int foundjvd = 0;
        int pvd_sum = 0;

        secno = hs_findvoldesc(vp->v_rdev, ISO_VOLDESC_SEC);
        secbp = bread(vp->v_rdev, secno * 4, ISO_SECTOR_SIZE);
        error = geterror(secbp);

        if (error != 0) {
                cmn_err(CE_NOTE, "hs_findisovol: bread: error=(%d)", error);
                brelse(secbp);
                return (error);
        }

        volp = (uchar_t *)secbp->b_un.b_addr;

        /*
         * To avoid that we read the whole medium in case that someone prepares
         * a malicious "fs image", we read at most 32 blocks.
         */
        for (n = 0; n < 32 && ISO_DESC_TYPE(volp) != ISO_VD_EOV; n++) {
                for (i = 0; i < ISO_ID_STRLEN; i++)
                        if (ISO_STD_ID(volp)[i] != ISO_ID_STRING[i])
                                goto cantfind;
                switch (ISO_DESC_TYPE(volp)) {
                case ISO_VD_PVD:
                        /* Standard File Structure */
                        if (ISO_STD_VER(volp) != ISO_ID_VER)
                                goto cantfind;
                        if (foundpvd != 1) {
                                fsp->hsfs_vol_type = HS_VOL_TYPE_ISO;
                                if (error = hs_parseisovol(fsp, volp, hvp)) {
                                        brelse(secbp);
                                        return (error);
                                }
                                foundpvd = 1;
                                for (i = 0; i < ISO_SECTOR_SIZE; i++)
                                        pvd_sum += volp[i];
                        }
                        break;
                case ISO_VD_SVD:
                        /* Supplementary Volume Descriptor */
                        if (ISO_STD_VER(volp) == ISO_ID_VER2 &&
                            foundsvd != 1) {
                                fsp->hsfs_vol_type = HS_VOL_TYPE_ISO;
                                if (error = hs_parseisovol(fsp, volp, svp)) {
                                        brelse(secbp);
                                        return (error);
                                }
                                foundsvd = 1;
                        }
                        if (hs_joliet_level(volp) >= 1 && foundjvd != 1) {
                                fsp->hsfs_vol_type = HS_VOL_TYPE_ISO;
                                if (error = hs_parseisovol(fsp, volp, jvp)) {
                                        brelse(secbp);
                                        return (error);
                                }
                                foundjvd = 1;
                        }
                        break;
                case ISO_VD_BOOT:
                        break;
                case ISO_VD_VPD:
                        /* currently cannot handle partition */
                        break;
                case VD_EOV:
                        break;
                }
                brelse(secbp);
                ++secno;
                secbp = bread(vp->v_rdev, secno * 4, HS_SECTOR_SIZE);
                error = geterror(secbp);

                if (error != 0) {
                        cmn_err(CE_NOTE, "hs_findisovol: bread: error=(%d)",
                            error);
                        brelse(secbp);
                        return (error);
                }

                volp = (uchar_t *)secbp->b_un.b_addr;
        }
        for (n = 0; n < 16; n++) {
                brelse(secbp);
                ++secno;
                secbp = bread(vp->v_rdev, secno * 4, HS_SECTOR_SIZE);
                error = geterror(secbp);

                if (error != 0) {
                        cmn_err(CE_NOTE, "hs_findisovol: bread: error=(%d)",
                            error);
                        brelse(secbp);
                        return (error);
                }

                /*
                 * Check for the signature from mkisofs that grants that
                 * the current filesystem allows to use the extent lbn as
                 * inode number even in pure ISO9660 mode.
                 */
                volp = (uchar_t *)secbp->b_un.b_addr;
                if (strncmp((char *)volp, "MKI ", 4) == 0) {
                        int     sum;

                        sum  = volp[2045];
                        sum *= 256;
                        sum += volp[2046];
                        sum *= 256;
                        sum += volp[2047];
                        if (sum == pvd_sum)
                                fsp->hsfs_flags |= HSFSMNT_INODE;
                        break;
                }
        }
        if (foundpvd) {
                brelse(secbp);
                return (0);
        }
cantfind:
        brelse(secbp);
        return (EINVAL);
}

/*
 * Return 0 if no Joliet is found
 * else return Joliet Level 1..3
 */
static int
hs_joliet_level(uchar_t *volp)
{
        if (ISO_std_ver(volp)[0] == ISO_ID_VER &&
            ISO_svd_esc(volp)[0] == '%' &&
            ISO_svd_esc(volp)[1] == '/') {

                switch (ISO_svd_esc(volp)[2]) {

                case '@':
                        return (1);
                case 'C':
                        return (2);
                case 'E':
                        return (3);
                }
        }
        return (0);
}

/*
 * hs_parseisovol
 *
 * Parse the Primary Volume Descriptor into an hs_volume structure.
 *
 */
static int
hs_parseisovol(struct hsfs *fsp, uchar_t *volp, struct hs_volume *hvp)
{
        hvp->vol_size = ISO_VOL_SIZE(volp);
        hvp->lbn_size = ISO_BLK_SIZE(volp);
        if (hvp->lbn_size == 0) {
                cmn_err(CE_NOTE, "hs_parseisovol: logical block size in the "
                    "PVD is zero");
                return (EINVAL);
        }
        hvp->lbn_shift = ffs((long)hvp->lbn_size) - 1;
        hvp->lbn_secshift =
            ffs((long)howmany(ISO_SECTOR_SIZE, (int)hvp->lbn_size)) - 1;
        hvp->lbn_maxoffset = hvp->lbn_size - 1;
        hs_parse_longdate(ISO_cre_date(volp), &hvp->cre_date);
        hs_parse_longdate(ISO_mod_date(volp), &hvp->mod_date);
        hvp->file_struct_ver = ISO_FILE_STRUCT_VER(volp);
        hvp->ptbl_len = ISO_PTBL_SIZE(volp);
        hvp->vol_set_size = (ushort_t)ISO_SET_SIZE(volp);
        hvp->vol_set_seq = (ushort_t)ISO_SET_SEQ(volp);
#if defined(_LITTLE_ENDIAN)
        hvp->ptbl_lbn = ISO_PTBL_MAN_LS(volp);
#else
        hvp->ptbl_lbn = ISO_PTBL_MAN_MS(volp);
#endif
        hs_copylabel(hvp, ISO_VOL_ID(volp), hs_joliet_level(volp) >= 1);

        /*
         * Make sure that lbn_size is a power of two and otherwise valid.
         */
        if (hvp->lbn_size & ~(1 << hvp->lbn_shift)) {
                cmn_err(CE_NOTE,
                    "hsfs: %d-byte logical block size not supported",
                    hvp->lbn_size);
                return (EINVAL);
        }
        return (hs_parsedir(fsp, ISO_ROOT_DIR(volp), &hvp->root_dir,
            NULL, NULL, IDE_ROOT_DIR_REC_SIZE));
}

/*
 * Common code for mount and umount.
 * Check that the user's argument is a reasonable
 * thing on which to mount, and return the device number if so.
 */
static int
hs_getmdev(struct vfs *vfsp, char *fspec, int flags, dev_t *pdev, mode_t *mode,
    cred_t *cr)
{
        int error;
        struct vnode *svp = NULL;
        struct vnode *lvp = NULL;
        struct vnode *bvp;
        struct vattr vap;
        dev_t dev;
        enum uio_seg fromspace = (flags & MS_SYSSPACE) ?
            UIO_SYSSPACE : UIO_USERSPACE;

        /*
         * Look up the device/file to be mounted.
         */
        error = lookupname(fspec, fromspace, FOLLOW, NULLVPP, &svp);
        if (error) {
                if (error == ENOENT)
                        error = ENODEV;
                goto out;
        }

        error = vfs_get_lofi(vfsp, &lvp);

        if (error > 0) {
                if (error == ENOENT)
                        error = ENODEV;
                goto out;
        } else if (error == 0) {
                bvp = lvp;
        } else {
                bvp = svp;

                if (bvp->v_type != VBLK) {
                        error = ENOTBLK;
                        goto out;
                }

                if ((error = secpolicy_spec_open(cr, bvp, FREAD)) != 0)
                        goto out;
        }

        /*
         * Can we read from the device/file ?
         */
        if ((error = fop_access(svp, VREAD, 0, cr, NULL)) != 0)
                goto out;

        vap.va_mask = AT_MODE;          /* get protection mode */
        (void) fop_getattr(bvp, &vap, 0, CRED(), NULL);
        *mode = vap.va_mode;

        dev = *pdev = bvp->v_rdev;

        error = EBUSY;

        /*
         * Ensure that this device isn't already mounted,
         * unless this is a REMOUNT request or we are told to suppress
         * mount checks.
         */
        if ((flags & MS_NOCHECK) == 0) {
                if (vfs_devmounting(dev, vfsp))
                        goto out;
                if (vfs_devismounted(dev) && !(flags & MS_REMOUNT))
                        goto out;
        }

        if (getmajor(*pdev) >= devcnt) {
                error = ENXIO;
                goto out;
        }

        error = 0;
out:
        if (svp != NULL)
                VN_RELE(svp);
        if (lvp != NULL)
                VN_RELE(lvp);
        return (error);
}

static void
hs_copylabel(struct hs_volume *hvp, unsigned char *label, int isjoliet)
{
        char    lbuf[64];       /* hs_joliet_cp() creates 48 bytes at most */

        if (isjoliet) {
                /*
                 * hs_joliet_cp() will output 16..48 bytes.
                 * We need to clear 'lbuf' to avoid junk chars past byte 15.
                 */
                bzero(lbuf, sizeof (lbuf));
                (void) hs_joliet_cp((char *)label, lbuf, 32);
                label = (unsigned char *)lbuf;
        }
        /* cdrom volid is at most 32 bytes */
        bcopy(label, hvp->vol_id, 32);
        hvp->vol_id[31] = '\0';
}

/*
 * Mount root file system.
 * "why" is ROOT_INIT on initial call, ROOT_REMOUNT if called to
 * remount the root file system, and ROOT_UNMOUNT if called to
 * unmount the root (e.g., as part of a system shutdown).
 *
 * XXX - this may be partially machine-dependent; it, along with the VFS_SWAPVP
 * operation, goes along with auto-configuration.  A mechanism should be
 * provided by which machine-INdependent code in the kernel can say "get me the
 * right root file system" and "get me the right initial swap area", and have
 * that done in what may well be a machine-dependent fashion.
 * Unfortunately, it is also file-system-type dependent (NFS gets it via
 * bootparams calls, UFS gets it from various and sundry machine-dependent
 * mechanisms, as SPECFS does for swap).
 */
static int
hsfs_mountroot(struct vfs *vfsp, enum whymountroot why)
{
        int error;
        struct hsfs *fsp;
        struct hs_volume *fvolp;
        static int hsfsrootdone = 0;
        dev_t rootdev;
        mode_t mode = 0;

        if (why == ROOT_INIT) {
                if (hsfsrootdone++)
                        return (EBUSY);
                rootdev = getrootdev();
                if (rootdev == (dev_t)NODEV)
                        return (ENODEV);
                vfsp->vfs_dev = rootdev;
                vfsp->vfs_flag |= VFS_RDONLY;
        } else if (why == ROOT_REMOUNT) {
                cmn_err(CE_NOTE, "hsfs_mountroot: ROOT_REMOUNT");
                return (0);
        } else if (why == ROOT_UNMOUNT) {
                return (0);
        }
        error = vfs_lock(vfsp);
        if (error) {
                cmn_err(CE_NOTE, "hsfs_mountroot: couldn't get vfs_lock");
                return (error);
        }

        error = hs_mountfs(vfsp, rootdev, "/", mode, 1, CRED(), 1);
        /*
         * XXX - assumes root device is not indirect, because we don't set
         * rootvp.  Is rootvp used for anything?  If so, make another arg
         * to mountfs.
         */
        if (error) {
                vfs_unlock(vfsp);
                if (rootvp) {
                        VN_RELE(rootvp);
                        rootvp = NULL;
                }
                return (error);
        }
        if (why == ROOT_INIT)
                vfs_add(NULL, vfsp,
                    (vfsp->vfs_flag & VFS_RDONLY) ? MS_RDONLY : 0);
        vfs_unlock(vfsp);
        fsp = VFS_TO_HSFS(vfsp);
        fvolp = &fsp->hsfs_vol;
#ifdef HSFS_CLKSET
        if (fvolp->cre_date.tv_sec == 0) {
                cmn_err(CE_NOTE, "hsfs_mountroot: cre_date.tv_sec == 0");
                if (fvolp->mod_date.tv_sec == 0) {
                        cmn_err(CE_NOTE,
                            "hsfs_mountroot: mod_date.tv_sec == 0");
                        cmn_err(CE_NOTE, "hsfs_mountroot: clkset(-1L)");
                        clkset(-1L);
                } else {
                        clkset(fvolp->mod_date.tv_sec);
                }
        } else {
                clkset(fvolp->mod_date.tv_sec);
        }
#else   /* HSFS_CLKSET */
        clkset(-1L);
#endif  /* HSFS_CLKSET */
        return (0);
}

/*
 * hs_findvoldesc()
 *
 * Return the sector where the volume descriptor lives.  This is
 * a fixed value for "normal" cd-rom's, but can change for
 * multisession cd's.
 *
 * desc_sec is the same for high-sierra and iso 9660 formats, why
 * there are two different #defines used in the code for this is
 * beyond me.  These are standards, cast in concrete, right?
 * To be general, however, this function supports passing in different
 * values.
 */
static int
hs_findvoldesc(dev_t rdev, int desc_sec)
{
        int secno;
        int error;
        int rval;       /* ignored */

#ifdef CDROMREADOFFSET
        /*
         * Issue the Read Offset ioctl directly to the
         * device. Ignore any errors and set starting
         * secno to the default, otherwise add the
         * VOLDESC sector number to the offset.
         */
        error = cdev_ioctl(rdev, CDROMREADOFFSET, (intptr_t)&secno,
            FNATIVE|FKIOCTL|FREAD, CRED(), &rval);
        if (error) {
                secno = desc_sec;
        } else {
                secno += desc_sec;
        }
#else
        secno = desc_sec;
#endif

        return (secno);
}