/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1994
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley
 * by Pace Willisson (pace@blitz.com).  The Rock Ridge Extension
 * Support code is derived from software contributed to Berkeley
 * by Atsushi Murai (amurai@spec.co.jp).
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/kernel.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/cdio.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/malloc.h>
#include <sys/stat.h>
#include <sys/syslog.h>
#include <sys/iconv.h>

#include <fs/cd9660/iso.h>
#include <fs/cd9660/iso_rrip.h>
#include <fs/cd9660/cd9660_node.h>
#include <fs/cd9660/cd9660_mount.h>

#include <geom/geom.h>
#include <geom/geom_vfs.h>

MALLOC_DEFINE(M_ISOFSMNT, "isofs_mount", "ISOFS mount structure");
MALLOC_DEFINE(M_ISOFSNODE, "isofs_node", "ISOFS vnode private part");

struct iconv_functions *cd9660_iconv = NULL;

static vfs_mount_t      cd9660_mount;
static vfs_cmount_t     cd9660_cmount;
static vfs_unmount_t    cd9660_unmount;
static vfs_root_t       cd9660_root;
static vfs_statfs_t     cd9660_statfs;
static vfs_vget_t       cd9660_vget;
static vfs_fhtovp_t     cd9660_fhtovp;

static struct vfsops cd9660_vfsops = {
        .vfs_fhtovp =           cd9660_fhtovp,
        .vfs_mount =            cd9660_mount,
        .vfs_cmount =           cd9660_cmount,
        .vfs_root =             cd9660_root,
        .vfs_statfs =           cd9660_statfs,
        .vfs_unmount =          cd9660_unmount,
        .vfs_vget =             cd9660_vget,
};
VFS_SET(cd9660_vfsops, cd9660, VFCF_READONLY);
MODULE_VERSION(cd9660, 1);

static int cd9660_vfs_hash_cmp(struct vnode *vp, void *pino);
static int iso_mountfs(struct vnode *devvp, struct mount *mp);

/*
 * VFS Operations.
 */

static int
cd9660_cmount(struct mntarg *ma, void *data, uint64_t flags)
{
        struct iso_args args;
        int error;

        error = copyin(data, &args, sizeof args);
        if (error)
                return (error);

        ma = mount_argsu(ma, "from", args.fspec, MAXPATHLEN);
        ma = mount_arg(ma, "export", &args.export, sizeof(args.export));
        if (args.flags & ISOFSMNT_UID)
                ma = mount_argf(ma, "uid", "%d", args.uid);
        if (args.flags & ISOFSMNT_GID)
                ma = mount_argf(ma, "gid", "%d", args.gid);
        ma = mount_argf(ma, "mask", "%d", args.fmask);
        ma = mount_argf(ma, "dirmask", "%d", args.dmask);
        ma = mount_argsu(ma, "cs_disk", args.cs_disk, 64);
        ma = mount_argsu(ma, "cs_local", args.cs_local, 64);
        ma = mount_argf(ma, "ssector", "%u", args.ssector);
        ma = mount_argb(ma, !(args.flags & ISOFSMNT_NORRIP), "norrip");
        ma = mount_argb(ma, args.flags & ISOFSMNT_GENS, "nogens");
        ma = mount_argb(ma, args.flags & ISOFSMNT_EXTATT, "noextatt");
        ma = mount_argb(ma, !(args.flags & ISOFSMNT_NOJOLIET), "nojoliet");
        ma = mount_argb(ma,
            args.flags & ISOFSMNT_BROKENJOLIET, "nobrokenjoliet");
        ma = mount_argb(ma, args.flags & ISOFSMNT_KICONV, "nokiconv");

        error = kernel_mount(ma, flags);

        return (error);
}

static int
cd9660_mount(struct mount *mp)
{
        struct vnode *devvp;
        struct thread *td;
        char *fspec;
        int error;
        accmode_t accmode;
        struct nameidata ndp;
        struct iso_mnt *imp = NULL;

        td = curthread;

        /*
         * Unconditionally mount as read-only.
         */
        MNT_ILOCK(mp);
        mp->mnt_flag |= MNT_RDONLY;
        MNT_IUNLOCK(mp);

        fspec = vfs_getopts(mp->mnt_optnew, "from", &error);
        if (error)
                return (error);

        imp = VFSTOISOFS(mp);

        if (mp->mnt_flag & MNT_UPDATE) {
                if (vfs_flagopt(mp->mnt_optnew, "export", NULL, 0))
                        return (0);
        }
        /*
         * Not an update, or updating the name: look up the name
         * and verify that it refers to a sensible block device.
         */
        NDINIT(&ndp, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, fspec);
        if ((error = namei(&ndp)))
                return (error);
        NDFREE_PNBUF(&ndp);
        devvp = ndp.ni_vp;

        if (!vn_isdisk_error(devvp, &error)) {
                vput(devvp);
                return (error);
        }

        /*
         * Verify that user has necessary permissions on the device,
         * or has superuser abilities
         */
        accmode = VREAD;
        error = VOP_ACCESS(devvp, accmode, td->td_ucred, td);
        if (error)
                error = priv_check(td, PRIV_VFS_MOUNT_PERM);
        if (error) {
                vput(devvp);
                return (error);
        }

        if ((mp->mnt_flag & MNT_UPDATE) == 0) {
                error = iso_mountfs(devvp, mp);
                if (error)
                        vrele(devvp);
        } else {
                if (devvp != imp->im_devvp)
                        error = EINVAL; /* needs translation */
                vput(devvp);
        }
        if (error)
                return (error);
        vfs_mountedfrom(mp, fspec);
        return (0);
}

/*
 * Common code for mount and mountroot
 */
static int
iso_mountfs(struct vnode *devvp, struct mount *mp)
{
        struct iso_mnt *isomp = NULL;
        struct buf *bp = NULL;
        struct buf *pribp = NULL, *supbp = NULL;
        struct cdev *dev;
        int error = EINVAL;
        int high_sierra = 0;
        int iso_bsize;
        int iso_blknum;
        int joliet_level;
        int isverified = 0;
        struct iso_volume_descriptor *vdp = NULL;
        struct iso_primary_descriptor *pri = NULL;
        struct iso_sierra_primary_descriptor *pri_sierra = NULL;
        struct iso_supplementary_descriptor *sup = NULL;
        struct iso_directory_record *rootp;
        int logical_block_size, ssector;
        struct g_consumer *cp;
        struct bufobj *bo;
        char *cs_local, *cs_disk;
        int v;

        dev = devvp->v_rdev;
        dev_ref(dev);
        g_topology_lock();
        error = g_vfs_open(devvp, &cp, "cd9660", 0);
        if (error == 0)
                g_getattr("MNT::verified", cp, &isverified);
        g_topology_unlock();
        VOP_UNLOCK(devvp);
        if (error)
                goto out;
        if (devvp->v_rdev->si_iosize_max != 0)
                mp->mnt_iosize_max = devvp->v_rdev->si_iosize_max;
        if (mp->mnt_iosize_max > maxphys)
                mp->mnt_iosize_max = maxphys;

        bo = &devvp->v_bufobj;

        /* This is the "logical sector size".  The standard says this
         * should be 2048 or the physical sector size on the device,
         * whichever is greater.
         */
        if ((ISO_DEFAULT_BLOCK_SIZE % cp->provider->sectorsize) != 0) {
                error = EINVAL;
                goto out;
        }

        iso_bsize = cp->provider->sectorsize;

        joliet_level = 0;
        if (1 != vfs_scanopt(mp->mnt_optnew, "ssector", "%d", &ssector))
                ssector = 0;
        for (iso_blknum = 16 + ssector;
             iso_blknum < 100 + ssector;
             iso_blknum++) {
                if ((error = bread(devvp, iso_blknum * btodb(ISO_DEFAULT_BLOCK_SIZE),
                                  iso_bsize, NOCRED, &bp)) != 0)
                        goto out;

                vdp = (struct iso_volume_descriptor *)bp->b_data;
                if (bcmp (vdp->id, ISO_STANDARD_ID, sizeof vdp->id) != 0) {
                        if (bcmp (vdp->id_sierra, ISO_SIERRA_ID,
                                  sizeof vdp->id_sierra) != 0) {
                                error = EINVAL;
                                goto out;
                        } else
                                high_sierra = 1;
                }
                switch (isonum_711 (high_sierra? vdp->type_sierra: vdp->type)){
                case ISO_VD_PRIMARY:
                        if (pribp == NULL) {
                                pribp = bp;
                                bp = NULL;
                                pri = (struct iso_primary_descriptor *)vdp;
                                pri_sierra =
                                  (struct iso_sierra_primary_descriptor *)vdp;
                        }
                        break;

                case ISO_VD_SUPPLEMENTARY:
                        if (supbp == NULL) {
                                supbp = bp;
                                bp = NULL;
                                sup = (struct iso_supplementary_descriptor *)vdp;

                                if (!vfs_flagopt(mp->mnt_optnew, "nojoliet", NULL, 0)) {
                                        if (bcmp(sup->escape, "%/@", 3) == 0)
                                                joliet_level = 1;
                                        if (bcmp(sup->escape, "%/C", 3) == 0)
                                                joliet_level = 2;
                                        if (bcmp(sup->escape, "%/E", 3) == 0)
                                                joliet_level = 3;

                                        if ((isonum_711 (sup->flags) & 1) &&
                                            !vfs_flagopt(mp->mnt_optnew, "brokenjoliet", NULL, 0))
                                                joliet_level = 0;
                                }
                        }
                        break;

                case ISO_VD_END:
                        goto vd_end;

                default:
                        break;
                }
                if (bp != NULL) {
                        brelse(bp);
                        bp = NULL;
                }
        }
 vd_end:
        if (bp != NULL) {
                brelse(bp);
                bp = NULL;
        }

        if (pri == NULL) {
                error = EINVAL;
                goto out;
        }

        logical_block_size =
                isonum_723 (high_sierra?
                            pri_sierra->logical_block_size:
                            pri->logical_block_size);

        if (logical_block_size < DEV_BSIZE || logical_block_size > MAXBSIZE
            || (logical_block_size & (logical_block_size - 1)) != 0) {
                error = EINVAL;
                goto out;
        }

        if (logical_block_size < cp->provider->sectorsize) {
                printf("cd9660: Unsupported logical block size %u\n",
                    logical_block_size);
                error = EINVAL;
                goto out;
        }

        rootp = (struct iso_directory_record *)
                (high_sierra?
                 pri_sierra->root_directory_record:
                 pri->root_directory_record);

        isomp = malloc(sizeof *isomp, M_ISOFSMNT, M_WAITOK | M_ZERO);
        isomp->im_cp = cp;
        isomp->im_bo = bo;
        isomp->logical_block_size = logical_block_size;
        isomp->volume_space_size =
                isonum_733 (high_sierra?
                            pri_sierra->volume_space_size:
                            pri->volume_space_size);
        isomp->joliet_level = 0;
        /*
         * Since an ISO9660 multi-session CD can also access previous
         * sessions, we have to include them into the space consider-
         * ations.  This doesn't yield a very accurate number since
         * parts of the old sessions might be inaccessible now, but we
         * can't do much better.  This is also important for the NFS
         * filehandle validation.
         */
        isomp->volume_space_size += ssector;
        memcpy(isomp->root, rootp, sizeof isomp->root);
        isomp->root_extent = isonum_733 (rootp->extent);
        isomp->root_size = isonum_733 (rootp->size);

        isomp->im_bmask = logical_block_size - 1;
        isomp->im_bshift = ffs(logical_block_size) - 1;

        pribp->b_flags |= B_AGE;
        brelse(pribp);
        pribp = NULL;
        rootp = NULL;
        pri = NULL;
        pri_sierra = NULL;

        mp->mnt_data = isomp;
        mp->mnt_stat.f_fsid.val[0] = dev2udev(dev);
        mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum;
        MNT_ILOCK(mp);
        if (isverified)
                mp->mnt_flag |= MNT_VERIFIED;
        mp->mnt_flag |= MNT_LOCAL;
        mp->mnt_kern_flag |= MNTK_LOOKUP_SHARED | MNTK_EXTENDED_SHARED;
        MNT_IUNLOCK(mp);
        isomp->im_mountp = mp;
        isomp->im_dev = dev;
        isomp->im_devvp = devvp;
        isomp->im_fmask = isomp->im_dmask = ALLPERMS;

        vfs_flagopt(mp->mnt_optnew, "norrip", &isomp->im_flags, ISOFSMNT_NORRIP);
        vfs_flagopt(mp->mnt_optnew, "gens", &isomp->im_flags, ISOFSMNT_GENS);
        vfs_flagopt(mp->mnt_optnew, "extatt", &isomp->im_flags, ISOFSMNT_EXTATT);
        vfs_flagopt(mp->mnt_optnew, "nojoliet", &isomp->im_flags, ISOFSMNT_NOJOLIET);
        vfs_flagopt(mp->mnt_optnew, "kiconv", &isomp->im_flags, ISOFSMNT_KICONV);

        if (vfs_scanopt(mp->mnt_optnew, "uid", "%d", &v) == 1) {
                isomp->im_flags |= ISOFSMNT_UID;
                isomp->im_uid = v;
        }
        if (vfs_scanopt(mp->mnt_optnew, "gid", "%d", &v) == 1) {
                isomp->im_flags |= ISOFSMNT_GID;
                isomp->im_gid = v;
        }
        if (vfs_scanopt(mp->mnt_optnew, "mask", "%d", &v) == 1) {
                isomp->im_fmask &= v;
        }
        if (vfs_scanopt(mp->mnt_optnew, "dirmask", "%d", &v) == 1) {
                isomp->im_dmask &= v;
        }

        /* Check the Rock Ridge Extension support */
        if (!(isomp->im_flags & ISOFSMNT_NORRIP)) {
                if ((error = bread(isomp->im_devvp, (isomp->root_extent +
                    isonum_711(((struct iso_directory_record *)isomp->root)->
                    ext_attr_length)) << (isomp->im_bshift - DEV_BSHIFT),
                    isomp->logical_block_size, NOCRED, &bp)) != 0)
                        goto out;

                rootp = (struct iso_directory_record *)bp->b_data;

                if ((isomp->rr_skip = cd9660_rrip_offset(rootp,isomp)) < 0) {
                    isomp->im_flags |= ISOFSMNT_NORRIP;
                } else {
                    isomp->im_flags &= ~ISOFSMNT_GENS;
                }

                /*
                 * The contents are valid,
                 * but they will get reread as part of another vnode, so...
                 */
                bp->b_flags |= B_AGE;
                brelse(bp);
                bp = NULL;
                rootp = NULL;
        }

        if (isomp->im_flags & ISOFSMNT_KICONV && cd9660_iconv) {
                cs_local = vfs_getopts(mp->mnt_optnew, "cs_local", &error);
                if (error)
                        goto out;
                cs_disk = vfs_getopts(mp->mnt_optnew, "cs_disk", &error);
                if (error)
                        goto out;
                cd9660_iconv->open(cs_local, cs_disk, &isomp->im_d2l);
                cd9660_iconv->open(cs_disk, cs_local, &isomp->im_l2d);
        } else {
                isomp->im_d2l = NULL;
                isomp->im_l2d = NULL;
        }

        if (high_sierra) {
                /* this effectively ignores all the mount flags */
                if (bootverbose)
                        log(LOG_INFO, "cd9660: High Sierra Format\n");
                isomp->iso_ftype = ISO_FTYPE_HIGH_SIERRA;
        } else
                switch (isomp->im_flags&(ISOFSMNT_NORRIP|ISOFSMNT_GENS)) {
                  default:
                          isomp->iso_ftype = ISO_FTYPE_DEFAULT;
                          break;
                  case ISOFSMNT_GENS|ISOFSMNT_NORRIP:
                          isomp->iso_ftype = ISO_FTYPE_9660;
                          break;
                  case 0:
                          if (bootverbose)
                                  log(LOG_INFO, "cd9660: RockRidge Extension\n");
                          isomp->iso_ftype = ISO_FTYPE_RRIP;
                          break;
                }

        /* Decide whether to use the Joliet descriptor */

        if (isomp->iso_ftype != ISO_FTYPE_RRIP && joliet_level) {
                if (bootverbose)
                        log(LOG_INFO, "cd9660: Joliet Extension (Level %d)\n",
                            joliet_level);
                rootp = (struct iso_directory_record *)
                        sup->root_directory_record;
                memcpy(isomp->root, rootp, sizeof isomp->root);
                isomp->root_extent = isonum_733 (rootp->extent);
                isomp->root_size = isonum_733 (rootp->size);
                isomp->joliet_level = joliet_level;
                supbp->b_flags |= B_AGE;
        }

        if (supbp) {
                brelse(supbp);
                supbp = NULL;
                sup = NULL;
        }

        return 0;
out:
        if (bp != NULL)
                brelse(bp);
        if (pribp != NULL)
                brelse(pribp);
        if (supbp != NULL)
                brelse(supbp);
        if (cp != NULL) {
                g_topology_lock();
                g_vfs_close(cp);
                g_topology_unlock();
        }
        if (isomp) {
                free(isomp, M_ISOFSMNT);
                mp->mnt_data = NULL;
        }
        dev_rel(dev);
        return error;
}

/*
 * unmount system call
 */
static int
cd9660_unmount(struct mount *mp, int mntflags)
{
        struct iso_mnt *isomp;
        int error, flags = 0;

        if (mntflags & MNT_FORCE)
                flags |= FORCECLOSE;
        if ((error = vflush(mp, 0, flags, curthread)))
                return (error);

        isomp = VFSTOISOFS(mp);

        if (isomp->im_flags & ISOFSMNT_KICONV && cd9660_iconv) {
                if (isomp->im_d2l)
                        cd9660_iconv->close(isomp->im_d2l);
                if (isomp->im_l2d)
                        cd9660_iconv->close(isomp->im_l2d);
        }
        g_topology_lock();
        g_vfs_close(isomp->im_cp);
        g_topology_unlock();
        vrele(isomp->im_devvp);
        dev_rel(isomp->im_dev);
        free(isomp, M_ISOFSMNT);
        mp->mnt_data = NULL;
        return (error);
}

/*
 * Return root of a filesystem
 */
static int
cd9660_root(struct mount *mp, int flags, struct vnode **vpp)
{
        struct iso_mnt *imp = VFSTOISOFS(mp);
        struct iso_directory_record *dp =
            (struct iso_directory_record *)imp->root;
        ino_t ino = isodirino(dp, imp);

        /*
         * With RRIP we must use the `.' entry of the root directory.
         * Simply tell vget, that it's a relocated directory.
         */
        return (cd9660_vget_internal(mp, ino, flags, vpp,
            imp->iso_ftype == ISO_FTYPE_RRIP, dp));
}

/*
 * Get filesystem statistics.
 */
static int
cd9660_statfs(struct mount *mp, struct statfs *sbp)
{
        struct iso_mnt *isomp;

        isomp = VFSTOISOFS(mp);

        sbp->f_bsize = isomp->logical_block_size;
        sbp->f_iosize = sbp->f_bsize;   /* XXX */
        sbp->f_blocks = isomp->volume_space_size;
        sbp->f_bfree = 0; /* total free blocks */
        sbp->f_bavail = 0; /* blocks free for non superuser */
        sbp->f_files =  0; /* total files */
        sbp->f_ffree = 0; /* free file nodes */
        return 0;
}

/*
 * File handle to vnode
 *
 * Have to be really careful about stale file handles:
 * - check that the inode number is in range
 * - call iget() to get the locked inode
 * - check for an unallocated inode (i_mode == 0)
 * - check that the generation number matches
 */

/* ARGSUSED */
static int
cd9660_fhtovp(struct mount *mp, struct fid *fhp, int flags, struct vnode **vpp)
{
        struct ifid ifh;
        struct iso_node *ip;
        struct vnode *nvp;
        int error;

        memcpy(&ifh, fhp, sizeof(ifh));

#ifdef  ISOFS_DBG
        printf("fhtovp: ino %d, start %ld\n",
            ifh.ifid_ino, ifh.ifid_start);
#endif

        if ((error = VFS_VGET(mp, ifh.ifid_ino, LK_EXCLUSIVE, &nvp)) != 0) {
                *vpp = NULL;
                return (error);
        }
        ip = VTOI(nvp);
        if (ip->inode.iso_mode == 0) {
                vput(nvp);
                *vpp = NULL;
                return (ESTALE);
        }
        *vpp = nvp;
        vnode_create_vobject(*vpp, ip->i_size, curthread);
        return (0);
}

/*
 * Conform to standard VFS interface; can't vget arbitrary inodes beyond 4GB
 * into media with current inode scheme and 32-bit ino_t.  This shouldn't be
 * needed for anything other than nfsd, and who exports a mounted DVD over NFS?
 */
static int
cd9660_vget(struct mount *mp, ino_t ino, int flags, struct vnode **vpp)
{

        /*
         * XXXX
         * It would be nice if we didn't always set the `relocated' flag
         * and force the extra read, but I don't want to think about fixing
         * that right now.
         */
        return (cd9660_vget_internal(mp, ino, flags, vpp,
#if 0
            VFSTOISOFS(mp)->iso_ftype == ISO_FTYPE_RRIP,
#else
            0,
#endif
            (struct iso_directory_record *)0));
}

/* Use special comparator for full 64-bit ino comparison. */
static int
cd9660_vfs_hash_cmp(struct vnode *vp, void *pino)
{
        struct iso_node *ip;
        ino_t ino;

        ip = VTOI(vp);
        ino = *(ino_t *)pino;
        return (ip->i_number != ino);
}

int
cd9660_vget_internal(struct mount *mp, ino_t ino, int flags,
    struct vnode **vpp, int relocated, struct iso_directory_record *isodir)
{
        struct iso_mnt *imp;
        struct iso_node *ip;
        struct buf *bp;
        struct vnode *vp;
        int error;
        struct thread *td;

        td = curthread;
        error = vfs_hash_get(mp, ino, flags, td, vpp, cd9660_vfs_hash_cmp,
            &ino);
        if (error || *vpp != NULL)
                return (error);

        /*
         * We must promote to an exclusive lock for vnode creation.  This
         * can happen if lookup is passed LOCKSHARED.
         */
        if ((flags & LK_TYPE_MASK) == LK_SHARED) {
                flags &= ~LK_TYPE_MASK;
                flags |= LK_EXCLUSIVE;
        }

        /*
         * We do not lock vnode creation as it is believed to be too
         * expensive for such rare case as simultaneous creation of vnode
         * for same ino by different processes. We just allow them to race
         * and check later to decide who wins. Let the race begin!
         */

        imp = VFSTOISOFS(mp);

        /* Allocate a new vnode/iso_node. */
        if ((error = getnewvnode("isofs", mp, &cd9660_vnodeops, &vp)) != 0) {
                *vpp = NULL;
                return (error);
        }
        ip = malloc(sizeof(struct iso_node), M_ISOFSNODE,
            M_WAITOK | M_ZERO);
        vp->v_data = ip;
        ip->i_vnode = vp;
        ip->i_number = ino;

        lockmgr(vp->v_vnlock, LK_EXCLUSIVE, NULL);
        error = insmntque(vp, mp);
        if (error != 0) {
                free(ip, M_ISOFSNODE);
                *vpp = NULL;
                return (error);
        }
        error = vfs_hash_insert(vp, ino, flags, td, vpp, cd9660_vfs_hash_cmp,
            &ino);
        if (error || *vpp != NULL)
                return (error);

        if (isodir == NULL) {
                int lbn, off;

                lbn = lblkno(imp, ino);
                if (lbn >= imp->volume_space_size) {
                        vput(vp);
                        printf("fhtovp: lbn exceed volume space %d\n", lbn);
                        return (ESTALE);
                }

                off = blkoff(imp, ino);
                if (off + ISO_DIRECTORY_RECORD_SIZE > imp->logical_block_size) {
                        vput(vp);
                        printf("fhtovp: crosses block boundary %d\n",
                               off + ISO_DIRECTORY_RECORD_SIZE);
                        return (ESTALE);
                }

                error = bread(imp->im_devvp,
                              lbn << (imp->im_bshift - DEV_BSHIFT),
                              imp->logical_block_size, NOCRED, &bp);
                if (error) {
                        vput(vp);
                        printf("fhtovp: bread error %d\n",error);
                        return (error);
                }
                isodir = (struct iso_directory_record *)(bp->b_data + off);

                if (off + isonum_711(isodir->length) >
                    imp->logical_block_size) {
                        vput(vp);
                        brelse(bp);
                        printf("fhtovp: directory crosses block boundary %d[off=%d/len=%d]\n",
                               off +isonum_711(isodir->length), off,
                               isonum_711(isodir->length));
                        return (ESTALE);
                }

#if 0
                if (isonum_733(isodir->extent) +
                    isonum_711(isodir->ext_attr_length) != ifhp->ifid_start) {
                        brelse(bp);
                        printf("fhtovp: file start miss %d vs %d\n",
                               isonum_733(isodir->extent) + isonum_711(isodir->ext_attr_length),
                               ifhp->ifid_start);
                        return (ESTALE);
                }
#endif
        } else
                bp = NULL;

        ip->i_mnt = imp;

        if (relocated) {
                /*
                 * On relocated directories we must
                 * read the `.' entry out of a dir.
                 */
                ip->iso_start = ino >> imp->im_bshift;
                if (bp != NULL)
                        brelse(bp);
                if ((error = cd9660_blkatoff(vp, (off_t)0, NULL, &bp)) != 0) {
                        vput(vp);
                        return (error);
                }
                isodir = (struct iso_directory_record *)bp->b_data;
        }

        ip->iso_extent = isonum_733(isodir->extent);
        ip->i_size = isonum_733(isodir->size);
        ip->iso_start = isonum_711(isodir->ext_attr_length) + ip->iso_extent;

        /*
         * Setup time stamp, attribute
         */
        vp->v_type = VNON;
        switch (imp->iso_ftype) {
        default:        /* ISO_FTYPE_9660 */
            {
                struct buf *bp2;
                int off;
                if ((imp->im_flags & ISOFSMNT_EXTATT)
                    && (off = isonum_711(isodir->ext_attr_length)))
                        cd9660_blkatoff(vp, (off_t)-(off << imp->im_bshift), NULL,
                                     &bp2);
                else
                        bp2 = NULL;
                cd9660_defattr(isodir, ip, bp2, ISO_FTYPE_9660);
                cd9660_deftstamp(isodir, ip, bp2, ISO_FTYPE_9660);
                if (bp2)
                        brelse(bp2);
                break;
            }
        case ISO_FTYPE_RRIP:
                cd9660_rrip_analyze(isodir, ip, imp);
                break;
        }

        brelse(bp);

        /*
         * Initialize the associated vnode
         */
        switch (vp->v_type = IFTOVT(ip->inode.iso_mode)) {
        case VFIFO:
                vp->v_op = &cd9660_fifoops;
                break;
        default:
                VN_LOCK_ASHARE(vp);
                break;
        }

        if (ip->iso_extent == imp->root_extent)
                vp->v_vflag |= VV_ROOT;

        /*
         * XXX need generation number?
         */

        vn_set_state(vp, VSTATE_CONSTRUCTED);
        *vpp = vp;
        return (0);
}