/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2001, 2002 Scott Long <scottl@freebsd.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 */

/* udf_vfsops.c */
/* Implement the VFS side of things */

/*
 * Ok, here's how it goes.  The UDF specs are pretty clear on how each data
 * structure is made up, but not very clear on how they relate to each other.
 * Here is the skinny... This demonstrates a filesystem with one file in the
 * root directory.  Subdirectories are treated just as normal files, but they
 * have File Id Descriptors of their children as their file data.  As for the
 * Anchor Volume Descriptor Pointer, it can exist in two of the following three
 * places: sector 256, sector n (the max sector of the disk), or sector
 * n - 256.  It's a pretty good bet that one will exist at sector 256 though.
 * One caveat is unclosed CD media.  For that, sector 256 cannot be written,
 * so the Anchor Volume Descriptor Pointer can exist at sector 512 until the
 * media is closed.
 *
 *  Sector:
 *     256:
 *       n: Anchor Volume Descriptor Pointer
 * n - 256:     |
 *              |
 *              |-->Main Volume Descriptor Sequence
 *                      |       |
 *                      |       |
 *                      |       |-->Logical Volume Descriptor
 *                      |                         |
 *                      |-->Partition Descriptor  |
 *                              |                 |
 *                              |                 |
 *                              |-->Fileset Descriptor
 *                                      |
 *                                      |
 *                                      |-->Root Dir File Entry
 *                                              |
 *                                              |
 *                                              |-->File data:
 *                                                  File Id Descriptor
 *                                                      |
 *                                                      |
 *                                                      |-->File Entry
 *                                                              |
 *                                                              |
 *                                                              |-->File data
 */
#include <sys/types.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/uio.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/conf.h>
#include <sys/dirent.h>
#include <sys/fcntl.h>
#include <sys/iconv.h>
#include <sys/kernel.h>
#include <sys/limits.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/queue.h>
#include <sys/vnode.h>
#include <sys/endian.h>

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

#include <vm/uma.h>

#include <fs/udf/ecma167-udf.h>
#include <fs/udf/osta.h>
#include <fs/udf/udf.h>
#include <fs/udf/udf_mount.h>

static MALLOC_DEFINE(M_UDFMOUNT, "udf_mount", "UDF mount structure");
MALLOC_DEFINE(M_UDFFENTRY, "udf_fentry", "UDF file entry structure");

struct iconv_functions *udf_iconv = NULL;

/* Zones */
uma_zone_t udf_zone_trans = NULL;
uma_zone_t udf_zone_node = NULL;
uma_zone_t udf_zone_ds = NULL;

static vfs_init_t      udf_init;
static vfs_uninit_t    udf_uninit;
static vfs_mount_t     udf_mount;
static vfs_root_t      udf_root;
static vfs_statfs_t    udf_statfs;
static vfs_unmount_t   udf_unmount;
static vfs_fhtovp_t     udf_fhtovp;

static int udf_find_partmaps(struct udf_mnt *, struct logvol_desc *);

static struct vfsops udf_vfsops = {
        .vfs_fhtovp =           udf_fhtovp,
        .vfs_init =             udf_init,
        .vfs_mount =            udf_mount,
        .vfs_root =             udf_root,
        .vfs_statfs =           udf_statfs,
        .vfs_uninit =           udf_uninit,
        .vfs_unmount =          udf_unmount,
        .vfs_vget =             udf_vget,
};
VFS_SET(udf_vfsops, udf, VFCF_READONLY);

MODULE_VERSION(udf, 1);

static int udf_mountfs(struct vnode *, struct mount *);

static int
udf_init(struct vfsconf *foo)
{

        udf_zone_trans = uma_zcreate("UDF translation buffer, zone", MAXNAMLEN *
            sizeof(unicode_t), NULL, NULL, NULL, NULL, 0, 0);

        udf_zone_node = uma_zcreate("UDF Node zone", sizeof(struct udf_node),
            NULL, NULL, NULL, NULL, 0, 0);

        udf_zone_ds = uma_zcreate("UDF Dirstream zone",
            sizeof(struct udf_dirstream), NULL, NULL, NULL, NULL, 0, 0);

        return 0;
}

static int
udf_uninit(struct vfsconf *foo)
{

        if (udf_zone_trans != NULL) {
                uma_zdestroy(udf_zone_trans);
                udf_zone_trans = NULL;
        }

        if (udf_zone_node != NULL) {
                uma_zdestroy(udf_zone_node);
                udf_zone_node = NULL;
        }

        if (udf_zone_ds != NULL) {
                uma_zdestroy(udf_zone_ds);
                udf_zone_ds = NULL;
        }

        return (0);
}

static int
udf_mount(struct mount *mp)
{
        struct vnode *devvp;    /* vnode of the mount device */
        struct thread *td;
        struct udf_mnt *imp = NULL;
        struct vfsoptlist *opts;
        char *fspec, *cs_disk, *cs_local;
        int error, len, *udf_flags;
        struct nameidata nd, *ndp = &nd;

        td = curthread;
        opts = mp->mnt_optnew;

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

        /*
         * No root filesystem support.  Probably not a big deal, since the
         * bootloader doesn't understand UDF.
         */
        if (mp->mnt_flag & MNT_ROOTFS)
                return (ENOTSUP);

        fspec = NULL;
        error = vfs_getopt(opts, "from", (void **)&fspec, &len);
        if (!error && fspec[len - 1] != '\0')
                return (EINVAL);

        if (mp->mnt_flag & MNT_UPDATE) {
                return (0);
        }

        /* Check that the mount device exists */
        if (fspec == NULL)
                return (EINVAL);
        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);
        }

        /* Check the access rights on the mount device */
        error = VOP_ACCESS(devvp, VREAD, td->td_ucred, td);
        if (error)
                error = priv_check(td, PRIV_VFS_MOUNT_PERM);
        if (error) {
                vput(devvp);
                return (error);
        }

        if ((error = udf_mountfs(devvp, mp))) {
                vrele(devvp);
                return (error);
        }

        imp = VFSTOUDFFS(mp);

        udf_flags = NULL;
        error = vfs_getopt(opts, "flags", (void **)&udf_flags, &len);
        if (error || len != sizeof(int))
                return (EINVAL);
        imp->im_flags = *udf_flags;

        if (imp->im_flags & UDFMNT_KICONV && udf_iconv) {
                cs_disk = NULL;
                error = vfs_getopt(opts, "cs_disk", (void **)&cs_disk, &len);
                if (!error && cs_disk[len - 1] != '\0')
                        return (EINVAL);
                cs_local = NULL;
                error = vfs_getopt(opts, "cs_local", (void **)&cs_local, &len);
                if (!error && cs_local[len - 1] != '\0')
                        return (EINVAL);
                udf_iconv->open(cs_local, cs_disk, &imp->im_d2l);
#if 0
                udf_iconv->open(cs_disk, cs_local, &imp->im_l2d);
#endif
        }

        vfs_mountedfrom(mp, fspec);
        return 0;
};

/*
 * Check the descriptor tag for both the correct id and correct checksum.
 * Return zero if all is good, EINVAL if not.
 */
int
udf_checktag(struct desc_tag *tag, uint16_t id)
{
        uint8_t *itag;
        uint8_t i, cksum = 0;

        itag = (uint8_t *)tag;

        if (le16toh(tag->id) != id)
                return (EINVAL);

        for (i = 0; i < 16; i++)
                cksum = cksum + itag[i];
        cksum = cksum - itag[4];

        if (cksum == tag->cksum)
                return (0);

        return (EINVAL);
}

static int
udf_mountfs(struct vnode *devvp, struct mount *mp)
{
        struct buf *bp = NULL;
        struct cdev *dev;
        struct anchor_vdp avdp;
        struct udf_mnt *udfmp = NULL;
        struct part_desc *pd;
        struct logvol_desc *lvd;
        struct fileset_desc *fsd;
        struct file_entry *root_fentry;
        uint32_t sector, size, mvds_start, mvds_end;
        uint32_t logical_secsize;
        uint32_t fsd_offset = 0;
        uint16_t part_num = 0, fsd_part = 0;
        int error = EINVAL;
        int logvol_found = 0, part_found = 0, fsd_found = 0;
        int bsize;
        struct g_consumer *cp;
        struct bufobj *bo;

        dev = devvp->v_rdev;
        dev_ref(dev);
        g_topology_lock();
        error = g_vfs_open(devvp, &cp, "udf", 0);
        g_topology_unlock();
        VOP_UNLOCK(devvp);
        if (error)
                goto bail;

        bo = &devvp->v_bufobj;

        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;

        /* XXX: should be M_WAITOK */
        udfmp = malloc(sizeof(struct udf_mnt), M_UDFMOUNT,
            M_NOWAIT | M_ZERO);
        if (udfmp == NULL) {
                printf("Cannot allocate UDF mount struct\n");
                error = ENOMEM;
                goto bail;
        }

        mp->mnt_data = udfmp;
        mp->mnt_stat.f_fsid.val[0] = dev2udev(devvp->v_rdev);
        mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum;
        MNT_ILOCK(mp);
        mp->mnt_flag |= MNT_LOCAL;
        mp->mnt_kern_flag |= MNTK_LOOKUP_SHARED | MNTK_EXTENDED_SHARED;
        MNT_IUNLOCK(mp);
        udfmp->im_mountp = mp;
        udfmp->im_dev = dev;
        udfmp->im_devvp = devvp;
        udfmp->im_d2l = NULL;
        udfmp->im_cp = cp;
        udfmp->im_bo = bo;

#if 0
        udfmp->im_l2d = NULL;
#endif
        /*
         * The UDF specification defines a logical sectorsize of 2048
         * for DVD media.
         */
        logical_secsize = 2048;

        if (((logical_secsize % cp->provider->sectorsize) != 0) ||
            (logical_secsize < cp->provider->sectorsize)) {
                error = EINVAL;
                goto bail;
        }

        bsize = cp->provider->sectorsize;

        /* 
         * Get the Anchor Volume Descriptor Pointer from sector 256.
         * XXX Should also check sector n - 256, n, and 512.
         */
        sector = 256;
        if ((error = bread(devvp, sector * btodb(logical_secsize), bsize,
                           NOCRED, &bp)) != 0)
                goto bail;
        if ((error = udf_checktag((struct desc_tag *)bp->b_data, TAGID_ANCHOR)))
                goto bail;

        bcopy(bp->b_data, &avdp, sizeof(struct anchor_vdp));
        brelse(bp);
        bp = NULL;

        /*
         * Extract the Partition Descriptor and Logical Volume Descriptor
         * from the Volume Descriptor Sequence.
         * XXX Should we care about the partition type right now?
         * XXX What about multiple partitions?
         */
        mvds_start = le32toh(avdp.main_vds_ex.loc);
        mvds_end = mvds_start + (le32toh(avdp.main_vds_ex.len) - 1) / bsize;
        for (sector = mvds_start; sector < mvds_end; sector++) {
                if ((error = bread(devvp, sector * btodb(logical_secsize),
                                   bsize, NOCRED, &bp)) != 0) {
                        printf("Can't read sector %d of VDS\n", sector);
                        goto bail;
                }
                lvd = (struct logvol_desc *)bp->b_data;
                if (!udf_checktag(&lvd->tag, TAGID_LOGVOL)) {
                        udfmp->bsize = le32toh(lvd->lb_size);
                        if (udfmp->bsize < 0 || udfmp->bsize > maxbcachebuf) {
                                printf("lvd block size %d\n", udfmp->bsize);
                                error = EINVAL;
                                goto bail;
                        }
                        udfmp->bmask = udfmp->bsize - 1;
                        udfmp->bshift = ffs(udfmp->bsize) - 1;
                        fsd_part = le16toh(lvd->_lvd_use.fsd_loc.loc.part_num);
                        fsd_offset = le32toh(lvd->_lvd_use.fsd_loc.loc.lb_num);
                        if (udf_find_partmaps(udfmp, lvd))
                                break;
                        logvol_found = 1;
                }
                pd = (struct part_desc *)bp->b_data;
                if (!udf_checktag(&pd->tag, TAGID_PARTITION)) {
                        part_found = 1;
                        part_num = le16toh(pd->part_num);
                        udfmp->part_len = le32toh(pd->part_len);
                        udfmp->part_start = le32toh(pd->start_loc);
                }

                brelse(bp); 
                bp = NULL;
                if ((part_found) && (logvol_found))
                        break;
        }

        if (!part_found || !logvol_found) {
                error = EINVAL;
                goto bail;
        }

        if (fsd_part != part_num) {
                printf("FSD does not lie within the partition!\n");
                error = EINVAL;
                goto bail;
        }

        /*
         * Grab the Fileset Descriptor
         * Thanks to Chuck McCrobie <mccrobie@cablespeed.com> for pointing
         * me in the right direction here.
         */
        sector = udfmp->part_start + fsd_offset;
        if ((error = RDSECTOR(devvp, sector, udfmp->bsize, &bp)) != 0) {
                printf("Cannot read sector %d of FSD\n", sector);
                goto bail;
        }
        fsd = (struct fileset_desc *)bp->b_data;
        if (!udf_checktag(&fsd->tag, TAGID_FSD)) {
                fsd_found = 1;
                bcopy(&fsd->rootdir_icb, &udfmp->root_icb,
                    sizeof(struct long_ad));
        }

        brelse(bp);
        bp = NULL;

        if (!fsd_found) {
                printf("Couldn't find the fsd\n");
                error = EINVAL;
                goto bail;
        }

        /*
         * Find the file entry for the root directory.
         */
        sector = le32toh(udfmp->root_icb.loc.lb_num) + udfmp->part_start;
        size = le32toh(udfmp->root_icb.len);
        if (size < UDF_FENTRY_SIZE) {
                printf("Invalid root directory file entry length %u\n",
                    size);
                goto bail;
        }
        if ((error = udf_readdevblks(udfmp, sector, size, &bp)) != 0) {
                printf("Cannot read sector %d\n", sector);
                goto bail;
        }

        root_fentry = (struct file_entry *)bp->b_data;
        if ((error = udf_checktag(&root_fentry->tag, TAGID_FENTRY))) {
                printf("Invalid root file entry!\n");
                goto bail;
        }

        brelse(bp);
        bp = NULL;

        return 0;

bail:
        if (udfmp != NULL)
                free(udfmp, M_UDFMOUNT);
        if (bp != NULL)
                brelse(bp);
        if (cp != NULL) {
                g_topology_lock();
                g_vfs_close(cp);
                g_topology_unlock();
        }
        dev_rel(dev);
        return error;
};

static int
udf_unmount(struct mount *mp, int mntflags)
{
        struct udf_mnt *udfmp;
        int error, flags = 0;

        udfmp = VFSTOUDFFS(mp);

        if (mntflags & MNT_FORCE)
                flags |= FORCECLOSE;

        if ((error = vflush(mp, 0, flags, curthread)))
                return (error);

        if (udfmp->im_flags & UDFMNT_KICONV && udf_iconv) {
                if (udfmp->im_d2l)
                        udf_iconv->close(udfmp->im_d2l);
#if 0
                if (udfmp->im_l2d)
                        udf_iconv->close(udfmp->im_l2d);
#endif
        }

        g_topology_lock();
        g_vfs_close(udfmp->im_cp);
        g_topology_unlock();
        vrele(udfmp->im_devvp);
        dev_rel(udfmp->im_dev);

        if (udfmp->s_table != NULL)
                free(udfmp->s_table, M_UDFMOUNT);

        free(udfmp, M_UDFMOUNT);

        mp->mnt_data = NULL;
        return (0);
}

static int
udf_root(struct mount *mp, int flags, struct vnode **vpp)
{
        struct udf_mnt *udfmp;
        ino_t id;

        udfmp = VFSTOUDFFS(mp);

        id = udf_getid(&udfmp->root_icb);

        return (udf_vget(mp, id, flags, vpp));
}

static int
udf_statfs(struct mount *mp, struct statfs *sbp)
{
        struct udf_mnt *udfmp;

        udfmp = VFSTOUDFFS(mp);

        sbp->f_bsize = udfmp->bsize;
        sbp->f_iosize = udfmp->bsize;
        sbp->f_blocks = udfmp->part_len;
        sbp->f_bfree = 0;
        sbp->f_bavail = 0;
        sbp->f_files = 0;
        sbp->f_ffree = 0;
        return 0;
}

int
udf_vget(struct mount *mp, ino_t ino, int flags, struct vnode **vpp)
{
        struct buf *bp;
        struct vnode *devvp;
        struct udf_mnt *udfmp;
        struct thread *td;
        struct vnode *vp;
        struct udf_node *unode;
        struct file_entry *fe;
        uint32_t lea, lad;
        int error, sector, size;

        error = vfs_hash_get(mp, ino, flags, curthread, vpp, NULL, NULL);
        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!
         */

        td = curthread;
        udfmp = VFSTOUDFFS(mp);

        unode = uma_zalloc(udf_zone_node, M_WAITOK | M_ZERO);

        if ((error = udf_allocv(mp, &vp, td))) {
                printf("Error from udf_allocv\n");
                uma_zfree(udf_zone_node, unode);
                return (error);
        }

        unode->i_vnode = vp;
        unode->hash_id = ino;
        unode->udfmp = udfmp;
        vp->v_data = unode;

        lockmgr(vp->v_vnlock, LK_EXCLUSIVE, NULL);
        error = insmntque(vp, mp);
        if (error != 0) {
                uma_zfree(udf_zone_node, unode);
                return (error);
        }
        error = vfs_hash_insert(vp, ino, flags, td, vpp, NULL, NULL);
        if (error || *vpp != NULL)
                return (error);

        /*
         * Copy in the file entry.  Per the spec, the size can only be 1 block.
         */
        sector = ino + udfmp->part_start;
        devvp = udfmp->im_devvp;
        if ((error = RDSECTOR(devvp, sector, udfmp->bsize, &bp)) != 0) {
                printf("Cannot read sector %d\n", sector);
                goto error;
        }

        /*
         * File entry length validation.
         */
        fe = (struct file_entry *)bp->b_data;
        if (udf_checktag(&fe->tag, TAGID_FENTRY)) {
                printf("Invalid file entry!\n");
                error = ENOMEM;
                goto error;
        }
        lea = le32toh(fe->l_ea);
        lad = le32toh(fe->l_ad);
        if (lea > udfmp->bsize || lad > udfmp->bsize) {
                printf("Invalid EA and AD lengths %u, %u\n", lea, lad);
                error = EIO;
                goto error;
        }
        size = UDF_FENTRY_SIZE + lea + lad;
        if (size > udfmp->bsize) {
                printf("Invalid file entry size %u\n", size);
                error = EIO;
                goto error;
        }

        unode->fentry = malloc(size, M_UDFFENTRY, M_NOWAIT | M_ZERO);
        if (unode->fentry == NULL) {
                printf("Cannot allocate file entry block\n");
                error = ENOMEM;
                goto error;
        }

        bcopy(bp->b_data, unode->fentry, size);

        brelse(bp);
        bp = NULL;

        switch (unode->fentry->icbtag.file_type) {
        default:
                vp->v_type = VBAD;
                break;
        case 4:
                vp->v_type = VDIR;
                break;
        case 5:
                vp->v_type = VREG;
                break;
        case 6:
                vp->v_type = VBLK;
                break;
        case 7:
                vp->v_type = VCHR;
                break;
        case 9:
                vp->v_type = VFIFO;
                vp->v_op = &udf_fifoops;
                break;
        case 10:
                vp->v_type = VSOCK;
                break;
        case 12:
                vp->v_type = VLNK;
                break;
        }

        if (vp->v_type != VFIFO)
                VN_LOCK_ASHARE(vp);

        if (ino == udf_getid(&udfmp->root_icb))
                vp->v_vflag |= VV_ROOT;

        vn_set_state(vp, VSTATE_CONSTRUCTED);
        *vpp = vp;

        return (0);

error:
        vgone(vp);
        vput(vp);
        brelse(bp);
        *vpp = NULL;
        return (error);
}

static int
udf_fhtovp(struct mount *mp, struct fid *fhp, int flags, struct vnode **vpp)
{
        struct ifid *ifhp;
        struct vnode *nvp;
        struct udf_node *np;
        uint64_t fsize;
        int error;

        ifhp = (struct ifid *)fhp;

        if ((error = VFS_VGET(mp, ifhp->ifid_ino, LK_EXCLUSIVE, &nvp)) != 0) {
                *vpp = NULL;
                return (error);
        }

        np = VTON(nvp);
        fsize = le64toh(np->fentry->inf_len);
        if (fsize > OFF_MAX) {
                *vpp = NULL;
                return (EIO);
        }

        *vpp = nvp;
        vnode_create_vobject(*vpp, fsize, curthread);
        return (0);
}

static int
udf_find_partmaps(struct udf_mnt *udfmp, struct logvol_desc *lvd)
{
        struct part_map_spare *pms;
        struct regid *pmap_id;
        struct buf *bp;
        unsigned char regid_id[UDF_REGID_ID_SIZE + 1];
        int i, k, ptype, psize, error;
        uint8_t *pmap = (uint8_t *) &lvd->maps[0];

        for (i = 0; i < le32toh(lvd->n_pm); i++) {
                ptype = pmap[0];
                psize = pmap[1];
                if (((ptype != 1) && (ptype != 2)) ||
                    ((psize != UDF_PMAP_TYPE1_SIZE) &&
                     (psize != UDF_PMAP_TYPE2_SIZE))) {
                        printf("Invalid partition map found\n");
                        return (1);
                }

                if (ptype == 1) {
                        /* Type 1 map.  We don't care */
                        pmap += UDF_PMAP_TYPE1_SIZE;
                        continue;
                }

                /* Type 2 map.  Gotta find out the details */
                pmap_id = (struct regid *)&pmap[4];
                bzero(&regid_id[0], UDF_REGID_ID_SIZE);
                bcopy(&pmap_id->id[0], &regid_id[0], UDF_REGID_ID_SIZE);

                if (bcmp(&regid_id[0], "*UDF Sparable Partition",
                    UDF_REGID_ID_SIZE)) {
                        printf("Unsupported partition map: %s\n", &regid_id[0]);
                        return (1);
                }

                pms = (struct part_map_spare *)pmap;
                pmap += UDF_PMAP_TYPE2_SIZE;
                udfmp->s_table = malloc(le32toh(pms->st_size),
                    M_UDFMOUNT, M_NOWAIT | M_ZERO);
                if (udfmp->s_table == NULL)
                        return (ENOMEM);

                /* Calculate the number of sectors per packet. */
                /* XXX Logical or physical? */
                udfmp->p_sectors = le16toh(pms->packet_len) / udfmp->bsize;

                /*
                 * XXX If reading the first Sparing Table fails, should look
                 * for another table.
                 */
                if ((error = udf_readdevblks(udfmp, le32toh(pms->st_loc[0]),
                                           le32toh(pms->st_size), &bp)) != 0) {
                        if (bp != NULL)
                                brelse(bp);
                        printf("Failed to read Sparing Table at sector %d\n",
                            le32toh(pms->st_loc[0]));
                        free(udfmp->s_table, M_UDFMOUNT);
                        return (error);
                }
                bcopy(bp->b_data, udfmp->s_table, le32toh(pms->st_size));
                brelse(bp);

                if (udf_checktag(&udfmp->s_table->tag, 0)) {
                        printf("Invalid sparing table found\n");
                        free(udfmp->s_table, M_UDFMOUNT);
                        return (EINVAL);
                }

                /* See how many valid entries there are here.  The list is
                 * supposed to be sorted. 0xfffffff0 and higher are not valid
                 */
                for (k = 0; k < le16toh(udfmp->s_table->rt_l); k++) {
                        udfmp->s_table_entries = k;
                        if (le32toh(udfmp->s_table->entries[k].org) >=
                            0xfffffff0)
                                break;
                }
        }

        return (0);
}