root/sys/fs/udf/udf_subr.c
/* $NetBSD: udf_subr.c,v 1.178 2025/11/22 21:27:08 andvar Exp $ */

/*
 * Copyright (c) 2006, 2008 Reinoud Zandijk
 * 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 ``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 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/cdefs.h>
#ifndef lint
__KERNEL_RCSID(0, "$NetBSD: udf_subr.c,v 1.178 2025/11/22 21:27:08 andvar Exp $");
#endif /* not lint */


#if defined(_KERNEL_OPT)
#include "opt_compat_netbsd.h"
#endif

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/kernel.h>
#include <sys/vnode.h>
#include <miscfs/genfs/genfs_node.h>
#include <sys/mount.h>
#include <sys/buf.h>
#include <sys/file.h>
#include <sys/device.h>
#include <sys/disklabel.h>
#include <sys/ioctl.h>
#include <sys/malloc.h>
#include <sys/dirent.h>
#include <sys/stat.h>
#include <sys/conf.h>
#include <sys/kauth.h>
#include <fs/unicode.h>
#include <dev/clock_subr.h>

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

#include "udf.h"
#include "udf_subr.h"
#include "udf_bswap.h"


#define VTOI(vnode) ((struct udf_node *) (vnode)->v_data)

#define UDF_SET_SYSTEMFILE(vp) \
        /* XXXAD Is the vnode locked? */        \
        (vp)->v_vflag |= VV_SYSTEM;             \
        vref((vp));                     \
        vput((vp));                     \

extern int syncer_maxdelay;     /* maximum delay time */
extern int (**udf_vnodeop_p)(void *);

/* --------------------------------------------------------------------- */

//#ifdef DEBUG
#if 1

#if 0
static void
udf_dumpblob(boid *blob, uint32_t dlen)
{
        int i, j;

        printf("blob = %p\n", blob);
        printf("dump of %d bytes\n", dlen);

        for (i = 0; i < dlen; i+ = 16) {
                printf("%04x ", i);
                for (j = 0; j < 16; j++) {
                        if (i+j < dlen) {
                                printf("%02x ", blob[i+j]);
                        } else {
                                printf("   ");
                        }
                }
                for (j = 0; j < 16; j++) {
                        if (i+j < dlen) {
                                if (blob[i+j]>32 && blob[i+j]! = 127) {
                                        printf("%c", blob[i+j]);
                                } else {
                                        printf(".");
                                }
                        }
                }
                printf("\n");
        }
        printf("\n");
        Debugger();
}
#endif

static void
udf_dump_discinfo(struct udf_mount *ump)
{
        char   bits[128];
        struct mmc_discinfo *di = &ump->discinfo;

        if ((udf_verbose & UDF_DEBUG_VOLUMES) == 0)
                return;

        printf("Device/media info  :\n");
        printf("\tMMC profile        0x%02x\n", di->mmc_profile);
        printf("\tderived class      %d\n", di->mmc_class);
        printf("\tsector size        %d\n", di->sector_size);
        printf("\tdisc state         %d\n", di->disc_state);
        printf("\tlast ses state     %d\n", di->last_session_state);
        printf("\tbg format state    %d\n", di->bg_format_state);
        printf("\tfrst track         %d\n", di->first_track);
        printf("\tfst on last ses    %d\n", di->first_track_last_session);
        printf("\tlst on last ses    %d\n", di->last_track_last_session);
        printf("\tlink block penalty %d\n", di->link_block_penalty);
        snprintb(bits, sizeof(bits), MMC_DFLAGS_FLAGBITS, di->disc_flags);
        printf("\tdisc flags         %s\n", bits);
        printf("\tdisc id            %x\n", di->disc_id);
        printf("\tdisc barcode       %"PRIx64"\n", di->disc_barcode);

        printf("\tnum sessions       %d\n", di->num_sessions);
        printf("\tnum tracks         %d\n", di->num_tracks);

        snprintb(bits, sizeof(bits), MMC_CAP_FLAGBITS, di->mmc_cur);
        printf("\tcapabilities cur   %s\n", bits);
        snprintb(bits, sizeof(bits), MMC_CAP_FLAGBITS, di->mmc_cap);
        printf("\tcapabilities cap   %s\n", bits);
}

static void
udf_dump_trackinfo(struct mmc_trackinfo *trackinfo)
{
        char   bits[128];

        if ((udf_verbose & UDF_DEBUG_VOLUMES) == 0)
                return;

        printf("Trackinfo for track %d:\n", trackinfo->tracknr);
        printf("\tsessionnr           %d\n", trackinfo->sessionnr);
        printf("\ttrack mode          %d\n", trackinfo->track_mode);
        printf("\tdata mode           %d\n", trackinfo->data_mode);
        snprintb(bits, sizeof(bits), MMC_TRACKINFO_FLAGBITS, trackinfo->flags);
        printf("\tflags               %s\n", bits);

        printf("\ttrack start         %d\n", trackinfo->track_start);
        printf("\tnext_writable       %d\n", trackinfo->next_writable);
        printf("\tfree_blocks         %d\n", trackinfo->free_blocks);
        printf("\tpacket_size         %d\n", trackinfo->packet_size);
        printf("\ttrack size          %d\n", trackinfo->track_size);
        printf("\tlast recorded block %d\n", trackinfo->last_recorded);
}

#else
#define udf_dump_discinfo(a);
#define udf_dump_trackinfo(a);
#endif


/* --------------------------------------------------------------------- */

/* not called often */
int
udf_update_discinfo(struct udf_mount *ump)
{
        struct vnode *devvp = ump->devvp;
        uint64_t psize;
        unsigned secsize;
        struct mmc_discinfo *di;
        int error;

        DPRINTF(VOLUMES, ("read/update disc info\n"));
        di = &ump->discinfo;
        memset(di, 0, sizeof(struct mmc_discinfo));

        /* check if we're on a MMC capable device, i.e. CD/DVD */
        error = VOP_IOCTL(devvp, MMCGETDISCINFO, di, FKIOCTL, NOCRED);
        if (error == 0) {
                udf_dump_discinfo(ump);
                return 0;
        }

        /* disc partition support */
        error = getdisksize(devvp, &psize, &secsize);
        if (error)
                return error;

        /* set up a disc info profile for partitions */
        di->mmc_profile         = 0x01; /* disc type */
        di->mmc_class           = MMC_CLASS_DISC;
        di->disc_state          = MMC_STATE_CLOSED;
        di->last_session_state  = MMC_STATE_CLOSED;
        di->bg_format_state     = MMC_BGFSTATE_COMPLETED;
        di->link_block_penalty  = 0;

        di->mmc_cur     = MMC_CAP_RECORDABLE | MMC_CAP_REWRITABLE |
                MMC_CAP_ZEROLINKBLK | MMC_CAP_HW_DEFECTFREE;
        di->mmc_cap    = di->mmc_cur;
        di->disc_flags = MMC_DFLAGS_UNRESTRICTED;

        /* TODO problem with last_possible_lba on resizable VND; request */
        di->last_possible_lba = psize;
        di->sector_size       = secsize;

        di->num_sessions = 1;
        di->num_tracks   = 1;

        di->first_track  = 1;
        di->first_track_last_session = di->last_track_last_session = 1;

        udf_dump_discinfo(ump);
        return 0;
}


int
udf_update_trackinfo(struct udf_mount *ump, struct mmc_trackinfo *ti)
{
        struct vnode *devvp = ump->devvp;
        struct mmc_discinfo *di = &ump->discinfo;
        int error, class;

        DPRINTF(VOLUMES, ("read track info\n"));

        class = di->mmc_class;
        if (class != MMC_CLASS_DISC) {
                /* tracknr specified in struct ti */
                error = VOP_IOCTL(devvp, MMCGETTRACKINFO, ti, FKIOCTL, NOCRED);
                return error;
        }

        /* disc partition support */
        if (ti->tracknr != 1)
                return EIO;

        /* create fake ti (TODO check for resized vnds) */
        ti->sessionnr  = 1;

        ti->track_mode = 0;     /* XXX */
        ti->data_mode  = 0;     /* XXX */
        ti->flags = MMC_TRACKINFO_LRA_VALID | MMC_TRACKINFO_NWA_VALID;

        ti->track_start    = 0;
        ti->packet_size    = 1;

        /* TODO support for resizable vnd */
        ti->track_size    = di->last_possible_lba;
        ti->next_writable = di->last_possible_lba;
        ti->last_recorded = ti->next_writable;
        ti->free_blocks   = 0;

        return 0;
}


int
udf_setup_writeparams(struct udf_mount *ump)
{
        struct mmc_writeparams mmc_writeparams;
        int error;

        if (ump->discinfo.mmc_class == MMC_CLASS_DISC)
                return 0;

        /*
         * only CD burning normally needs setting up, but other disc types
         * might need other settings to be made. The MMC framework will set up
         * the necessary recording parameters according to the disc
         * characteristics read in. Modifications can be made in the discinfo
         * structure passed to change the nature of the disc.
         */

        memset(&mmc_writeparams, 0, sizeof(struct mmc_writeparams));
        mmc_writeparams.mmc_class  = ump->discinfo.mmc_class;
        mmc_writeparams.mmc_cur    = ump->discinfo.mmc_cur;

        /*
         * UDF dictates first track to determine track mode for the whole
         * disc. [UDF 1.50/6.10.1.1, UDF 1.50/6.10.2.1]
         * To prevent problems with a `reserved' track in front we start with
         * the 2nd track and if that is not valid, go for the 1st.
         */
        mmc_writeparams.tracknr = 2;
        mmc_writeparams.data_mode  = MMC_DATAMODE_DEFAULT;      /* XA disc */
        mmc_writeparams.track_mode = MMC_TRACKMODE_DEFAULT;     /* data */

        error = VOP_IOCTL(ump->devvp, MMCSETUPWRITEPARAMS, &mmc_writeparams,
                        FKIOCTL, NOCRED);
        if (error) {
                mmc_writeparams.tracknr = 1;
                error = VOP_IOCTL(ump->devvp, MMCSETUPWRITEPARAMS,
                                &mmc_writeparams, FKIOCTL, NOCRED);
        }
        return error;
}


void
udf_mmc_synchronise_caches(struct udf_mount *ump)
{
        struct mmc_op mmc_op;

        DPRINTF(CALL, ("udf_mcc_synchronise_caches()\n"));

        if (ump->vfs_mountp->mnt_flag & MNT_RDONLY)
                return;

        /* discs are done now */
        if (ump->discinfo.mmc_class == MMC_CLASS_DISC)
                return;

        memset(&mmc_op, 0, sizeof(struct mmc_op));
        mmc_op.operation = MMC_OP_SYNCHRONISECACHE;

        /* ignore return code */
        (void) VOP_IOCTL(ump->devvp, MMCOP, &mmc_op, FKIOCTL, NOCRED);
}

/* --------------------------------------------------------------------- */

/* track/session searching for mounting */
int
udf_search_tracks(struct udf_mount *ump, struct udf_args *args,
                  int *first_tracknr, int *last_tracknr)
{
        struct mmc_trackinfo trackinfo;
        uint32_t tracknr, start_track, num_tracks;
        int error;

        /* if negative, sessionnr is relative to last session */
        if (args->sessionnr < 0) {
                args->sessionnr += ump->discinfo.num_sessions;
        }

        /* sanity */
        if (args->sessionnr < 0)
                args->sessionnr = 0;
        if (args->sessionnr > ump->discinfo.num_sessions)
                args->sessionnr = ump->discinfo.num_sessions;

        /* search the tracks for this session, zero session nr indicates last */
        if (args->sessionnr == 0)
                args->sessionnr = ump->discinfo.num_sessions;
        if (ump->discinfo.last_session_state == MMC_STATE_EMPTY)
                args->sessionnr--;

        /* sanity again */
        if (args->sessionnr < 0)
                args->sessionnr = 0;

        /* search the first and last track of the specified session */
        num_tracks  = ump->discinfo.num_tracks;
        start_track = ump->discinfo.first_track;

        /* search for first track of this session */
        for (tracknr = start_track; tracknr <= num_tracks; tracknr++) {
                /* get track info */
                trackinfo.tracknr = tracknr;
                error = udf_update_trackinfo(ump, &trackinfo);
                if (error)
                        return error;

                if (trackinfo.sessionnr == args->sessionnr)
                        break;
        }
        *first_tracknr = tracknr;

        /* search for last track of this session */
        for (;tracknr <= num_tracks; tracknr++) {
                /* get track info */
                trackinfo.tracknr = tracknr;
                error = udf_update_trackinfo(ump, &trackinfo);
                if (error || (trackinfo.sessionnr != args->sessionnr)) {
                        tracknr--;
                        break;
                }
        }
        if (tracknr > num_tracks)
                tracknr--;

        *last_tracknr = tracknr;

        if (*last_tracknr < *first_tracknr) {
                printf( "udf_search_tracks: sanity check on drive+disc failed, "
                        "drive returned garbage\n");
                return EINVAL;
        }

        assert(*last_tracknr >= *first_tracknr);
        return 0;
}


/*
 * NOTE: this is the only routine in this file that directly peeks into the
 * metadata file but since its at a larval state of the mount it can't hurt.
 *
 * XXX candidate for udf_allocation.c
 * XXX clean me up!, change to new node reading code.
 */

static void
udf_check_track_metadata_overlap(struct udf_mount *ump,
        struct mmc_trackinfo *trackinfo)
{
        struct part_desc *part;
        struct file_entry      *fe;
        struct extfile_entry   *efe;
        struct short_ad        *s_ad;
        struct long_ad         *l_ad;
        uint32_t track_start, track_end;
        uint32_t phys_part_start, phys_part_end, part_start, part_end;
        uint32_t sector_size, len, alloclen, plb_num;
        uint8_t *pos;
        int addr_type, icblen, icbflags;

        /* get our track extents */
        track_start = trackinfo->track_start;
        track_end   = track_start + trackinfo->track_size;

        /* get our base partition extent */
        KASSERT(ump->node_part == ump->fids_part);
        part = ump->partitions[ump->vtop[ump->node_part]];
        phys_part_start = udf_rw32(part->start_loc);
        phys_part_end   = phys_part_start + udf_rw32(part->part_len);

        /* no use if its outside the physical partition */
        if ((phys_part_start >= track_end) || (phys_part_end < track_start))
                return;

        /*
         * now follow all extents in the fe/efe to see if they refer to this
         * track
         */

        sector_size = ump->discinfo.sector_size;

        /* XXX should we claim exclusive access to the metafile ? */
        /* TODO: move to new node read code */
        fe  = ump->metadata_node->fe;
        efe = ump->metadata_node->efe;
        if (fe) {
                alloclen = udf_rw32(fe->l_ad);
                pos      = &fe->data[0] + udf_rw32(fe->l_ea);
                icbflags = udf_rw16(fe->icbtag.flags);
        } else {
                assert(efe);
                alloclen = udf_rw32(efe->l_ad);
                pos      = &efe->data[0] + udf_rw32(efe->l_ea);
                icbflags = udf_rw16(efe->icbtag.flags);
        }
        addr_type = icbflags & UDF_ICB_TAG_FLAGS_ALLOC_MASK;

        while (alloclen) {
                if (addr_type == UDF_ICB_SHORT_ALLOC) {
                        icblen = sizeof(struct short_ad);
                        s_ad   = (struct short_ad *) pos;
                        len        = udf_rw32(s_ad->len);
                        plb_num    = udf_rw32(s_ad->lb_num);
                } else {
                        /* should not be present, but why not */
                        icblen = sizeof(struct long_ad);
                        l_ad   = (struct long_ad *) pos;
                        len        = udf_rw32(l_ad->len);
                        plb_num    = udf_rw32(l_ad->loc.lb_num);
                        /* pvpart_num = udf_rw16(l_ad->loc.part_num); */
                }
                /* process extent */
                len     = UDF_EXT_LEN(len);

                part_start = phys_part_start + plb_num;
                part_end   = part_start + (len / sector_size);

                if ((part_start >= track_start) && (part_end <= track_end)) {
                        /* extent is enclosed within this track */
                        ump->metadata_track = *trackinfo;
                        return;
                }

                pos        += icblen;
                alloclen   -= icblen;
        }
}


int
udf_search_writing_tracks(struct udf_mount *ump)
{
        struct vnode *devvp = ump->devvp;
        struct mmc_trackinfo trackinfo;
        struct mmc_op        mmc_op;
        struct part_desc *part;
        uint32_t tracknr, start_track, num_tracks;
        uint32_t track_start, track_end, part_start, part_end;
        int node_alloc, error;

        /*
         * in the CD/(HD)DVD/BD recordable device model a few tracks within
         * the last session might be open but in the UDF device model at most
         * three tracks can be open: a reserved track for delayed ISO VRS
         * writing, a data track and a metadata track. We search here for the
         * data track and the metadata track. Note that the reserved track is
         * troublesome but can be detected by its small size of < 512 sectors.
         */

        /* update discinfo since it might have changed */
        error = udf_update_discinfo(ump);
        if (error)
                return error;

        num_tracks  = ump->discinfo.num_tracks;
        start_track = ump->discinfo.first_track;

        /* fetch info on first and possibly only track */
        trackinfo.tracknr = start_track;
        error = udf_update_trackinfo(ump, &trackinfo);
        if (error)
                return error;

        /* copy results to our mount point */
        ump->data_track     = trackinfo;
        ump->metadata_track = trackinfo;

        /* if not sequential, we're done */
        if (num_tracks == 1)
                return 0;

        for (tracknr = start_track;tracknr <= num_tracks; tracknr++) {
                /* get track info */
                trackinfo.tracknr = tracknr;
                error = udf_update_trackinfo(ump, &trackinfo);
                if (error)
                        return error;

                /*
                 * If this track is marked damaged, ask for repair. This is an
                 * optional command, so ignore its error but report warning.
                 */
                if (trackinfo.flags & MMC_TRACKINFO_DAMAGED) {
                        memset(&mmc_op, 0, sizeof(mmc_op));
                        mmc_op.operation   = MMC_OP_REPAIRTRACK;
                        mmc_op.mmc_profile = ump->discinfo.mmc_profile;
                        mmc_op.tracknr     = tracknr;
                        error = VOP_IOCTL(devvp, MMCOP, &mmc_op, FKIOCTL, NOCRED);
                        if (error)
                                (void)printf("Drive can't explicitly repair "
                                        "damaged track %d, but it might "
                                        "autorepair\n", tracknr);

                        /* reget track info */
                        error = udf_update_trackinfo(ump, &trackinfo);
                        if (error)
                                return error;
                }
                if ((trackinfo.flags & MMC_TRACKINFO_NWA_VALID) == 0)
                        continue;

                track_start = trackinfo.track_start;
                track_end   = track_start + trackinfo.track_size;

                /* check for overlap on data partition */
                part = ump->partitions[ump->data_part];
                part_start = udf_rw32(part->start_loc);
                part_end   = part_start + udf_rw32(part->part_len);
                if ((part_start < track_end) && (part_end > track_start)) {
                        ump->data_track = trackinfo;
                        /* TODO check if UDF partition data_part is writable */
                }

                /* check for overlap on metadata partition */
                node_alloc = ump->vtop_alloc[ump->node_part];
                if ((node_alloc == UDF_ALLOC_METASEQUENTIAL) ||
                    (node_alloc == UDF_ALLOC_METABITMAP)) {
                        udf_check_track_metadata_overlap(ump, &trackinfo);
                } else {
                        ump->metadata_track = trackinfo;
                }
        }

        if ((ump->data_track.flags & MMC_TRACKINFO_NWA_VALID) == 0)
                return EROFS;

        if ((ump->metadata_track.flags & MMC_TRACKINFO_NWA_VALID) == 0)
                return EROFS;

        return 0;
}

/* --------------------------------------------------------------------- */

/*
 * Check if the blob starts with a good UDF tag. Tags are protected by a
 * checksum over the header except one byte at position 4 that is the checksum
 * itself.
 */

int
udf_check_tag(void *blob)
{
        struct desc_tag *tag = blob;
        uint8_t *pos, sum, cnt;

        /* check TAG header checksum */
        pos = (uint8_t *) tag;
        sum = 0;

        for(cnt = 0; cnt < 16; cnt++) {
                if (cnt != 4)
                        sum += *pos;
                pos++;
        }
        if (sum != tag->cksum) {
                /* bad tag header checksum; this is not a valid tag */
                return EINVAL;
        }

        return 0;
}


/*
 * check tag payload will check descriptor CRC as specified.
 * If the descriptor is too long, it will return EIO otherwise EINVAL.
 */

int
udf_check_tag_payload(void *blob, uint32_t max_length)
{
        struct desc_tag *tag = blob;
        uint16_t crc, crc_len;

        crc_len = udf_rw16(tag->desc_crc_len);

        /* check payload CRC if applicable */
        if (crc_len == 0)
                return 0;

        if (crc_len > max_length)
                return EIO;

        crc = udf_cksum(((uint8_t *) tag) + UDF_DESC_TAG_LENGTH, crc_len);
        if (crc != udf_rw16(tag->desc_crc)) {
                /* bad payload CRC; this is a broken tag */
                return EINVAL;
        }

        return 0;
}


void
udf_validate_tag_sum(void *blob)
{
        struct desc_tag *tag = blob;
        uint8_t *pos, sum, cnt;

        /* calculate TAG header checksum */
        pos = (uint8_t *) tag;
        sum = 0;

        for(cnt = 0; cnt < 16; cnt++) {
                if (cnt != 4) sum += *pos;
                pos++;
        }
        tag->cksum = sum;       /* 8 bit */
}


/* assumes sector number of descriptor to be saved already present */
void
udf_validate_tag_and_crc_sums(void *blob)
{
        struct desc_tag *tag  = blob;
        uint8_t         *btag = (uint8_t *) tag;
        uint16_t crc, crc_len;

        crc_len = udf_rw16(tag->desc_crc_len);

        /* check payload CRC if applicable */
        if (crc_len > 0) {
                crc = udf_cksum(btag + UDF_DESC_TAG_LENGTH, crc_len);
                tag->desc_crc = udf_rw16(crc);
        }

        /* calculate TAG header checksum */
        udf_validate_tag_sum(blob);
}

/* --------------------------------------------------------------------- */

/*
 * XXX note the different semantics from udfclient: for FIDs it still rounds
 * up to sectors. Use udf_fidsize() for a correct length.
 */

int
udf_tagsize(union dscrptr *dscr, uint32_t lb_size)
{
        uint32_t size, tag_id, num_lb, elmsz;

        tag_id = udf_rw16(dscr->tag.id);

        switch (tag_id) {
        case TAGID_LOGVOL :
                size  = sizeof(struct logvol_desc) - 1;
                size += udf_rw32(dscr->lvd.mt_l);
                break;
        case TAGID_UNALLOC_SPACE :
                elmsz = sizeof(struct extent_ad);
                size  = sizeof(struct unalloc_sp_desc) - elmsz;
                size += udf_rw32(dscr->usd.alloc_desc_num) * elmsz;
                break;
        case TAGID_FID :
                size = UDF_FID_SIZE + dscr->fid.l_fi + udf_rw16(dscr->fid.l_iu);
                size = (size + 3) & ~3;
                break;
        case TAGID_LOGVOL_INTEGRITY :
                size  = sizeof(struct logvol_int_desc) - sizeof(uint32_t);
                size += udf_rw32(dscr->lvid.l_iu);
                size += (2 * udf_rw32(dscr->lvid.num_part) * sizeof(uint32_t));
                break;
        case TAGID_SPACE_BITMAP :
                size  = sizeof(struct space_bitmap_desc) - 1;
                size += udf_rw32(dscr->sbd.num_bytes);
                break;
        case TAGID_SPARING_TABLE :
                elmsz = sizeof(struct spare_map_entry);
                size  = sizeof(struct udf_sparing_table) - elmsz;
                size += udf_rw16(dscr->spt.rt_l) * elmsz;
                break;
        case TAGID_FENTRY :
                size  = sizeof(struct file_entry);
                size += udf_rw32(dscr->fe.l_ea) + udf_rw32(dscr->fe.l_ad)-1;
                break;
        case TAGID_EXTFENTRY :
                size  = sizeof(struct extfile_entry);
                size += udf_rw32(dscr->efe.l_ea) + udf_rw32(dscr->efe.l_ad)-1;
                break;
        case TAGID_FSD :
                size  = sizeof(struct fileset_desc);
                break;
        default :
                size = sizeof(union dscrptr);
                break;
        }

        if ((size == 0) || (lb_size == 0))
                return 0;

        if (lb_size == 1)
                return size;

        /* round up in sectors */
        num_lb = (size + lb_size -1) / lb_size;
        return num_lb * lb_size;
}


int
udf_fidsize(struct fileid_desc *fid)
{
        uint32_t size;

        if (udf_rw16(fid->tag.id) != TAGID_FID)
                panic("got udf_fidsize on non FID\n");

        size = UDF_FID_SIZE + fid->l_fi + udf_rw16(fid->l_iu);
        size = (size + 3) & ~3;

        return size;
}

/* --------------------------------------------------------------------- */

void
udf_lock_node(struct udf_node *udf_node, int flag, char const *fname, const int lineno)
{
        int ret;

        mutex_enter(&udf_node->node_mutex);
        /* wait until free */
        while (udf_node->i_flags & IN_LOCKED) {
                ret = cv_timedwait(&udf_node->node_lock, &udf_node->node_mutex, hz/8);
                /* TODO check if we should return error; abort */
                if (ret == EWOULDBLOCK) {
                        DPRINTF(LOCKING, ( "udf_lock_node: udf_node %p would block "
                                "wanted at %s:%d, previously locked at %s:%d\n",
                                udf_node, fname, lineno,
                                udf_node->lock_fname, udf_node->lock_lineno));
                }
        }
        /* grab */
        udf_node->i_flags |= IN_LOCKED | flag;
        /* debug */
        udf_node->lock_fname  = fname;
        udf_node->lock_lineno = lineno;

        mutex_exit(&udf_node->node_mutex);
}


void
udf_unlock_node(struct udf_node *udf_node, int flag)
{
        mutex_enter(&udf_node->node_mutex);
        udf_node->i_flags &= ~(IN_LOCKED | flag);
        cv_broadcast(&udf_node->node_lock);
        mutex_exit(&udf_node->node_mutex);
}


/* --------------------------------------------------------------------- */

static int
udf_read_anchor(struct udf_mount *ump, uint32_t sector, struct anchor_vdp **dst)
{
        int error;

        error = udf_read_phys_dscr(ump, sector, M_UDFVOLD,
                        (union dscrptr **) dst);
        if (!error) {
                /* blank terminator blocks are not allowed here */
                if (*dst == NULL)
                        return ENOENT;
                if (udf_rw16((*dst)->tag.id) != TAGID_ANCHOR) {
                        error = ENOENT;
                        free(*dst, M_UDFVOLD);
                        *dst = NULL;
                        DPRINTF(VOLUMES, ("Not an anchor\n"));
                }
        }

        return error;
}


int
udf_read_anchors(struct udf_mount *ump)
{
        struct udf_args *args = &ump->mount_args;
        struct mmc_trackinfo first_track;
        struct mmc_trackinfo second_track;
        struct mmc_trackinfo last_track;
        struct anchor_vdp **anchorsp;
        uint32_t track_start;
        uint32_t track_end;
        uint32_t positions[4];
        int first_tracknr, last_tracknr;
        int error, anch, ok, first_anchor;

        /* search the first and last track of the specified session */
        error = udf_search_tracks(ump, args, &first_tracknr, &last_tracknr);
        if (!error) {
                first_track.tracknr = first_tracknr;
                error = udf_update_trackinfo(ump, &first_track);
        }
        if (!error) {
                last_track.tracknr = last_tracknr;
                error = udf_update_trackinfo(ump, &last_track);
        }
        if ((!error) && (first_tracknr != last_tracknr)) {
                second_track.tracknr = first_tracknr+1;
                error = udf_update_trackinfo(ump, &second_track);
        }
        if (error) {
                printf("UDF mount: reading disc geometry failed\n");
                return 0;
        }

        track_start = first_track.track_start;

        /* `end' is not as straitforward as start. */
        track_end =   last_track.track_start
                    + last_track.track_size - last_track.free_blocks - 1;

        if (ump->discinfo.mmc_cur & MMC_CAP_SEQUENTIAL) {
                /* end of track is not straitforward here */
                if (last_track.flags & MMC_TRACKINFO_LRA_VALID)
                        track_end = last_track.last_recorded;
                else if (last_track.flags & MMC_TRACKINFO_NWA_VALID)
                        track_end = last_track.next_writable
                                    - ump->discinfo.link_block_penalty;
        }

        /* its no use reading a blank track */
        first_anchor = 0;
        if (first_track.flags & MMC_TRACKINFO_BLANK)
                first_anchor = 1;

        /* get our packet size */
        ump->packet_size = first_track.packet_size;
        if (first_track.flags & MMC_TRACKINFO_BLANK)
                ump->packet_size = second_track.packet_size;

        if (ump->packet_size <= 1) {
                /* take max, but not bigger than 64 */
                ump->packet_size = MAXPHYS / ump->discinfo.sector_size;
                ump->packet_size = MIN(ump->packet_size, 64);
        }
        KASSERT(ump->packet_size >= 1);

        /* read anchors start+256, start+512, end-256, end */
        positions[0] = track_start+256;
        positions[1] =   track_end-256;
        positions[2] =   track_end;
        positions[3] = track_start+512; /* [UDF 2.60/6.11.2] */
        /* XXX shouldn't +512 be preferred over +256 for compat with Roxio CD */

        ok = 0;
        anchorsp = ump->anchors;
        for (anch = first_anchor; anch < 4; anch++) {
                DPRINTF(VOLUMES, ("Read anchor %d at sector %d\n", anch,
                    positions[anch]));
                error = udf_read_anchor(ump, positions[anch], anchorsp);
                if (!error) {
                        anchorsp++;
                        ok++;
                }
        }

        /* VATs are only recorded on sequential media, but initialise */
        ump->first_possible_vat_location = track_start + 2;
        ump->last_possible_vat_location  = track_end;

        return ok;
}

/* --------------------------------------------------------------------- */

int
udf_get_c_type(struct udf_node *udf_node)
{
        int isdir, what;

        isdir  = (udf_node->vnode->v_type == VDIR);
        what   = isdir ? UDF_C_FIDS : UDF_C_USERDATA;

        if (udf_node->ump)
                if (udf_node == udf_node->ump->metadatabitmap_node)
                        what = UDF_C_METADATA_SBM;

        return what;
}


int
udf_get_record_vpart(struct udf_mount *ump, int udf_c_type)
{
        int vpart_num;

        vpart_num = ump->data_part;
        if (udf_c_type == UDF_C_NODE)
                vpart_num = ump->node_part;
        if (udf_c_type == UDF_C_FIDS)
                vpart_num = ump->fids_part;

        return vpart_num;
}


/*
 * BUGALERT: some rogue implementations use random physical partition
 * numbers to break other implementations so lookup the number.
 */

static uint16_t
udf_find_raw_phys(struct udf_mount *ump, uint16_t raw_phys_part)
{
        struct part_desc *part;
        uint16_t phys_part;

        for (phys_part = 0; phys_part < UDF_PARTITIONS; phys_part++) {
                part = ump->partitions[phys_part];
                if (part == NULL)
                        break;
                if (udf_rw16(part->part_num) == raw_phys_part)
                        break;
        }
        return phys_part;
}

/* --------------------------------------------------------------------- */

/* we dont try to be smart; we just record the parts */
#define UDF_UPDATE_DSCR(name, dscr) \
        if (name) \
                free(name, M_UDFVOLD); \
        name = dscr;

static int
udf_process_vds_descriptor(struct udf_mount *ump, union dscrptr *dscr)
{
        uint16_t phys_part, raw_phys_part;

        DPRINTF(VOLUMES, ("\tprocessing VDS descr %d\n",
            udf_rw16(dscr->tag.id)));
        switch (udf_rw16(dscr->tag.id)) {
        case TAGID_PRI_VOL :            /* primary partition            */
                UDF_UPDATE_DSCR(ump->primary_vol, &dscr->pvd);
                break;
        case TAGID_LOGVOL :             /* logical volume               */
                UDF_UPDATE_DSCR(ump->logical_vol, &dscr->lvd);
                break;
        case TAGID_UNALLOC_SPACE :      /* unallocated space            */
                UDF_UPDATE_DSCR(ump->unallocated, &dscr->usd);
                break;
        case TAGID_IMP_VOL :            /* implementation               */
                /* XXX do we care about multiple impl. descr ? */
                UDF_UPDATE_DSCR(ump->implementation, &dscr->ivd);
                break;
        case TAGID_PARTITION :          /* physical partition           */
                /* not much use if its not allocated */
                if ((udf_rw16(dscr->pd.flags) & UDF_PART_FLAG_ALLOCATED) == 0) {
                        free(dscr, M_UDFVOLD);
                        break;
                }

                /*
                 * BUGALERT: some rogue implementations use random physical
                 * partition numbers to break other implementations so lookup
                 * the number.
                 */
                raw_phys_part = udf_rw16(dscr->pd.part_num);
                phys_part = udf_find_raw_phys(ump, raw_phys_part);

                if (phys_part == UDF_PARTITIONS) {
                        free(dscr, M_UDFVOLD);
                        return EINVAL;
                }

                UDF_UPDATE_DSCR(ump->partitions[phys_part], &dscr->pd);
                break;
        case TAGID_VOL :                /* volume space extender; rare  */
                DPRINTF(VOLUMES, ("VDS extender ignored\n"));
                free(dscr, M_UDFVOLD);
                break;
        default :
                DPRINTF(VOLUMES, ("Unhandled VDS type %d\n",
                    udf_rw16(dscr->tag.id)));
                free(dscr, M_UDFVOLD);
        }

        return 0;
}
#undef UDF_UPDATE_DSCR

/* --------------------------------------------------------------------- */

static int
udf_read_vds_extent(struct udf_mount *ump, uint32_t loc, uint32_t len)
{
        union dscrptr *dscr;
        uint32_t sector_size, dscr_size;
        int error;

        sector_size = ump->discinfo.sector_size;

        /* loc is sectornr, len is in bytes */
        error = EIO;
        while (len) {
                error = udf_read_phys_dscr(ump, loc, M_UDFVOLD, &dscr);
                if (error)
                        return error;

                /* blank block is a terminator */
                if (dscr == NULL)
                        return 0;

                /* TERM descriptor is a terminator */
                if (udf_rw16(dscr->tag.id) == TAGID_TERM) {
                        free(dscr, M_UDFVOLD);
                        return 0;
                }

                /* process all others */
                dscr_size = udf_tagsize(dscr, sector_size);
                error = udf_process_vds_descriptor(ump, dscr);
                if (error) {
                        free(dscr, M_UDFVOLD);
                        break;
                }
                assert((dscr_size % sector_size) == 0);

                len -= dscr_size;
                loc += dscr_size / sector_size;
        }

        return error;
}


int
udf_read_vds_space(struct udf_mount *ump)
{
        /* struct udf_args *args = &ump->mount_args; */
        struct anchor_vdp *anchor, *anchor2;
        size_t size;
        uint32_t main_loc, main_len;
        uint32_t reserve_loc, reserve_len;
        int error;

        /*
         * read in VDS space provided by the anchors; if one descriptor read
         * fails, try the mirror sector.
         *
         * check if 2nd anchor is different from 1st; if so, go for 2nd. This
         * avoids the `compatibility features' of DirectCD that may confuse
         * stuff completely.
         */

        anchor  = ump->anchors[0];
        anchor2 = ump->anchors[1];
        assert(anchor);

        if (anchor2) {
                size = sizeof(struct extent_ad);
                if (memcmp(&anchor->main_vds_ex, &anchor2->main_vds_ex, size))
                        anchor = anchor2;
                /* reserve is specified to be a literal copy of main */
        }

        main_loc    = udf_rw32(anchor->main_vds_ex.loc);
        main_len    = udf_rw32(anchor->main_vds_ex.len);

        reserve_loc = udf_rw32(anchor->reserve_vds_ex.loc);
        reserve_len = udf_rw32(anchor->reserve_vds_ex.len);

        error = udf_read_vds_extent(ump, main_loc, main_len);
        if (error) {
                printf("UDF mount: reading in reserve VDS extent\n");
                error = udf_read_vds_extent(ump, reserve_loc, reserve_len);
        }

        return error;
}

/* --------------------------------------------------------------------- */

/*
 * Read in the logical volume integrity sequence pointed to by our logical
 * volume descriptor. Its a sequence that can be extended using fields in the
 * integrity descriptor itself. On sequential media only one is found, on
 * rewritable media a sequence of descriptors can be found as a form of
 * history keeping and on non sequential write-once media the chain is vital
 * to allow more and more descriptors to be written. The last descriptor
 * written in an extent needs to claim space for a new extent.
 */

static int
udf_retrieve_lvint(struct udf_mount *ump)
{
        union dscrptr *dscr;
        struct logvol_int_desc *lvint;
        struct udf_lvintq *trace;
        uint32_t lb_size, lbnum, len;
        int dscr_type, error, trace_len;

        lb_size = udf_rw32(ump->logical_vol->lb_size);
        len     = udf_rw32(ump->logical_vol->integrity_seq_loc.len);
        lbnum   = udf_rw32(ump->logical_vol->integrity_seq_loc.loc);

        /* clean trace */
        memset(ump->lvint_trace, 0,
            UDF_LVDINT_SEGMENTS * sizeof(struct udf_lvintq));

        trace_len    = 0;
        trace        = ump->lvint_trace;
        trace->start = lbnum;
        trace->end   = lbnum + len/lb_size;
        trace->pos   = 0;
        trace->wpos  = 0;

        lvint = NULL;
        dscr  = NULL;
        error = 0;
        while (len) {
                trace->pos  = lbnum - trace->start;
                trace->wpos = trace->pos + 1;

                /* read in our integrity descriptor */
                error = udf_read_phys_dscr(ump, lbnum, M_UDFVOLD, &dscr);
                if (!error) {
                        if (dscr == NULL) {
                                trace->wpos = trace->pos;
                                break;          /* empty terminates */
                        }
                        dscr_type = udf_rw16(dscr->tag.id);
                        if (dscr_type == TAGID_TERM) {
                                trace->wpos = trace->pos;
                                break;          /* clean terminator */
                        }
                        if (dscr_type != TAGID_LOGVOL_INTEGRITY) {
                                /* fatal... corrupt disc */
                                error = ENOENT;
                                break;
                        }
                        if (lvint)
                                free(lvint, M_UDFVOLD);
                        lvint = &dscr->lvid;
                        dscr = NULL;
                } /* else hope for the best... maybe the next is ok */

                DPRINTFIF(VOLUMES, lvint, ("logvol integrity read, state %s\n",
                    udf_rw32(lvint->integrity_type) ? "CLOSED" : "OPEN"));

                /* proceed sequential */
                lbnum += 1;
                len    -= lb_size;

                /* are we linking to a new piece? */
                if (dscr && lvint->next_extent.len) {
                        len   = udf_rw32(lvint->next_extent.len);
                        lbnum = udf_rw32(lvint->next_extent.loc);

                        if (trace_len >= UDF_LVDINT_SEGMENTS-1) {
                                /* IEK! segment link full... */
                                DPRINTF(VOLUMES, ("lvdint segments full\n"));
                                error = EINVAL;
                        } else {
                                trace++;
                                trace_len++;

                                trace->start = lbnum;
                                trace->end   = lbnum + len/lb_size;
                                trace->pos   = 0;
                                trace->wpos  = 0;
                        }
                }
        }

        /* clean up the mess, esp. when there is an error */
        if (dscr)
                free(dscr, M_UDFVOLD);

        if (error && lvint) {
                free(lvint, M_UDFVOLD);
                lvint = NULL;
        }

        if (!lvint)
                error = ENOENT;

        ump->logvol_integrity = lvint;
        return error;
}


static int
udf_loose_lvint_history(struct udf_mount *ump)
{
        union dscrptr **bufs, *dscr, *last_dscr;
        struct udf_lvintq *trace, *in_trace, *out_trace;
        struct logvol_int_desc *lvint;
        uint32_t in_ext, in_pos, in_len;
        uint32_t out_ext, out_wpos, out_len;
        uint32_t lb_num;
        uint32_t len, start;
        int ext, sumext, extlen, cnt, cpy_len, dscr_type;
        int losing;
        int error;

        DPRINTF(VOLUMES, ("need to lose some lvint history\n"));

        /* search smallest extent */
        trace = &ump->lvint_trace[0];
        sumext = trace->end - trace->start;
        for (ext = 1; ext < UDF_LVDINT_SEGMENTS; ext++) {
                trace = &ump->lvint_trace[ext];
                extlen = trace->end - trace->start;
                if (extlen == 0)
                        break;
                sumext += extlen;
        }

        /* just one element? its not legal but be bug compatible */
        if (sumext == 1) {
                /* overwrite the only entry */
                DPRINTF(VOLUMES, ("\tLinux bugcompat overwriting sole entry\n"));
                trace = &ump->lvint_trace[0];
                trace->wpos = 0;
                return 0;
        }

        losing = MIN(sumext, UDF_LVINT_LOSSAGE);

        /* no sense wiping too much */
        if (sumext == UDF_LVINT_LOSSAGE)
                losing = UDF_LVINT_LOSSAGE/2;

        DPRINTF(VOLUMES, ("\tlosing %d entries\n", losing));

        /* get buffer for pieces */
        bufs = malloc(UDF_LVDINT_SEGMENTS * sizeof(void *), M_TEMP, M_WAITOK);

        in_ext    = 0;
        in_pos    = losing;
        in_trace  = &ump->lvint_trace[in_ext];
        in_len    = in_trace->end - in_trace->start;
        out_ext   = 0;
        out_wpos  = 0;
        out_trace = &ump->lvint_trace[out_ext];
        out_len   = out_trace->end - out_trace->start;

        last_dscr = NULL;
        for(;;) {
                out_trace->pos  = out_wpos;
                out_trace->wpos = out_trace->pos;
                if (in_pos >= in_len) {
                        in_ext++;
                        in_pos = 0;
                        in_trace = &ump->lvint_trace[in_ext];
                        in_len   = in_trace->end - in_trace->start;
                }
                if (out_wpos >= out_len) {
                        out_ext++;
                        out_wpos = 0;
                        out_trace = &ump->lvint_trace[out_ext];
                        out_len   = out_trace->end - out_trace->start;
                }
                /* copy overlap contents */
                cpy_len = MIN(in_len - in_pos, out_len - out_wpos);
                cpy_len = MIN(cpy_len, in_len - in_trace->pos);
                if (cpy_len == 0)
                        break;

                /* copy */
                DPRINTF(VOLUMES, ("\treading %d lvid descriptors\n", cpy_len));
                for (cnt = 0; cnt < cpy_len; cnt++) {
                        /* read in our integrity descriptor */
                        lb_num = in_trace->start + in_pos + cnt;
                        error = udf_read_phys_dscr(ump, lb_num, M_UDFVOLD,
                                &dscr);
                        if (error) {
                                /* copy last one */
                                dscr = last_dscr;
                        }
                        bufs[cnt] = dscr;
                        if (!error) {
                                if (dscr == NULL) {
                                        out_trace->pos  = out_wpos + cnt;
                                        out_trace->wpos = out_trace->pos;
                                        break;          /* empty terminates */
                                }
                                dscr_type = udf_rw16(dscr->tag.id);
                                if (dscr_type == TAGID_TERM) {
                                        out_trace->pos  = out_wpos + cnt;
                                        out_trace->wpos = out_trace->pos;
                                        break;          /* clean terminator */
                                }
                                if (dscr_type != TAGID_LOGVOL_INTEGRITY) {
                                        panic(  "UDF integrity sequence "
                                                "corrupted while mounted!\n");
                                }
                                last_dscr = dscr;
                        }
                }

                /* patch up if first entry was on error */
                if (bufs[0] == NULL) {
                        for (cnt = 0; cnt < cpy_len; cnt++)
                                if (bufs[cnt] != NULL)
                                        break;
                        last_dscr = bufs[cnt];
                        for (; cnt > 0; cnt--) {
                                bufs[cnt] = last_dscr;
                        }
                }

                /* glue + write out */
                DPRINTF(VOLUMES, ("\twriting %d lvid descriptors\n", cpy_len));
                for (cnt = 0; cnt < cpy_len; cnt++) {
                        lb_num = out_trace->start + out_wpos + cnt;
                        lvint  = &bufs[cnt]->lvid;

                        /* set continuation */
                        len = 0;
                        start = 0;
                        if (out_wpos + cnt == out_len) {
                                /* get continuation */
                                trace = &ump->lvint_trace[out_ext+1];
                                len   = trace->end - trace->start;
                                start = trace->start;
                        }
                        lvint->next_extent.len = udf_rw32(len);
                        lvint->next_extent.loc = udf_rw32(start);

                        lb_num = trace->start + trace->wpos;
                        error = udf_write_phys_dscr_sync(ump, NULL, UDF_C_DSCR,
                                bufs[cnt], lb_num, lb_num);
                        DPRINTFIF(VOLUMES, error,
                                ("error writing lvint lb_num\n"));
                }

                /* free non repeating descriptors */
                last_dscr = NULL;
                for (cnt = 0; cnt < cpy_len; cnt++) {
                        if (bufs[cnt] != last_dscr)
                                free(bufs[cnt], M_UDFVOLD);
                        last_dscr = bufs[cnt];
                }

                /* advance */
                in_pos   += cpy_len;
                out_wpos += cpy_len;
        }

        free(bufs, M_TEMP);

        return 0;
}


static int
udf_writeout_lvint(struct udf_mount *ump, int lvflag)
{
        struct udf_lvintq *trace;
        struct timeval  now_v;
        struct timespec now_s;
        uint32_t sector;
        int logvol_integrity;
        int space, error;

        DPRINTF(VOLUMES, ("writing out logvol integrity descriptor\n"));

        /* get free space in last chunk */
        trace = ump->lvint_trace;
        while (trace->wpos > (trace->end - trace->start)) {
                DPRINTF(VOLUMES, ("skip : start = %d, end = %d, pos = %d, "
                                  "wpos = %d\n", trace->start, trace->end,
                                  trace->pos, trace->wpos));
                trace++;
        }

        /* check if there is space to append */
        space = (trace->end - trace->start) - trace->wpos;
        DPRINTF(VOLUMES, ("write start = %d, end = %d, pos = %d, wpos = %d, "
                          "space = %d\n", trace->start, trace->end, trace->pos,
                          trace->wpos, space));

        /* get state */
        logvol_integrity = udf_rw32(ump->logvol_integrity->integrity_type);
        if (logvol_integrity == UDF_INTEGRITY_CLOSED) {
                if ((space < 3) && (lvflag & UDF_APPENDONLY_LVINT)) {
                        /* TODO extent LVINT space if possible */
                        return EROFS;
                }
        }

        if (space < 1) {
                if (lvflag & UDF_APPENDONLY_LVINT)
                        return EROFS;

                /* loose history by re-writing extents */
                error = udf_loose_lvint_history(ump);
                if (error)
                        return error;

                trace = ump->lvint_trace;
                while (trace->wpos > (trace->end - trace->start))
                        trace++;
                space = (trace->end - trace->start) - trace->wpos;
                DPRINTF(VOLUMES, ("new try: write start = %d, end = %d, "
                                  "pos = %d, wpos = %d, "
                                  "space = %d\n", trace->start, trace->end,
                                  trace->pos, trace->wpos, space));
        }

        /* update our integrity descriptor to identify us and timestamp it */
        DPRINTF(VOLUMES, ("updating integrity descriptor\n"));
        microtime(&now_v);
        TIMEVAL_TO_TIMESPEC(&now_v, &now_s);
        udf_timespec_to_timestamp(&now_s, &ump->logvol_integrity->time);
        udf_set_regid(&ump->logvol_info->impl_id, IMPL_NAME);
        udf_add_impl_regid(ump, &ump->logvol_info->impl_id);

        /* writeout integrity descriptor */
        sector = trace->start + trace->wpos;
        error = udf_write_phys_dscr_sync(ump, NULL, UDF_C_DSCR,
                        (union dscrptr *) ump->logvol_integrity,
                        sector, sector);
        DPRINTF(VOLUMES, ("writeout lvint : error = %d\n", error));
        if (error)
                return error;

        /* advance write position */
        trace->wpos++; space--;
        if (space >= 1) {
                /* append terminator */
                sector = trace->start + trace->wpos;
                error = udf_write_terminator(ump, sector);

                DPRINTF(VOLUMES, ("write terminator : error = %d\n", error));
        }

        space = (trace->end - trace->start) - trace->wpos;
        DPRINTF(VOLUMES, ("write start = %d, end = %d, pos = %d, wpos = %d, "
                "space = %d\n", trace->start, trace->end, trace->pos,
                trace->wpos, space));
        DPRINTF(VOLUMES, ("finished writing out logvol integrity descriptor "
                "successfully\n"));

        return error;
}

/* --------------------------------------------------------------------- */

static int
udf_read_physical_partition_spacetables(struct udf_mount *ump)
{
        union dscrptr        *dscr;
        /* struct udf_args *args = &ump->mount_args; */
        struct part_desc     *partd;
        struct part_hdr_desc *parthdr;
        struct udf_bitmap    *bitmap;
        uint32_t phys_part;
        uint32_t lb_num, len;
        int error, dscr_type;

        /* unallocated space map */
        for (phys_part = 0; phys_part < UDF_PARTITIONS; phys_part++) {
                partd = ump->partitions[phys_part];
                if (partd == NULL)
                        continue;
                parthdr = &partd->_impl_use.part_hdr;

                lb_num  = udf_rw32(partd->start_loc);
                lb_num += udf_rw32(parthdr->unalloc_space_bitmap.lb_num);
                len     = udf_rw32(parthdr->unalloc_space_bitmap.len);
                if (len == 0)
                        continue;

                DPRINTF(VOLUMES, ("Read unalloc. space bitmap %d\n", lb_num));
                error = udf_read_phys_dscr(ump, lb_num, M_UDFVOLD, &dscr);
                if (!error && dscr) {
                        /* analyse */
                        dscr_type = udf_rw16(dscr->tag.id);
                        if (dscr_type == TAGID_SPACE_BITMAP) {
                                DPRINTF(VOLUMES, ("Accepting space bitmap\n"));
                                ump->part_unalloc_dscr[phys_part] = &dscr->sbd;

                                /* fill in ump->part_unalloc_bits */
                                bitmap = &ump->part_unalloc_bits[phys_part];
                                bitmap->blob  = (uint8_t *) dscr;
                                bitmap->bits  = dscr->sbd.data;
                                bitmap->max_offset = udf_rw32(dscr->sbd.num_bits);
                                bitmap->pages = NULL;   /* TODO */
                                bitmap->data_pos     = 0;
                                bitmap->metadata_pos = 0;
                        } else {
                                free(dscr, M_UDFVOLD);

                                printf( "UDF mount: error reading unallocated "
                                        "space bitmap\n");
                                return EROFS;
                        }
                } else {
                        /* blank not allowed */
                        printf("UDF mount: blank unallocated space bitmap\n");
                        return EROFS;
                }
        }

        /* unallocated space table (not supported) */
        for (phys_part = 0; phys_part < UDF_PARTITIONS; phys_part++) {
                partd = ump->partitions[phys_part];
                if (partd == NULL)
                        continue;
                parthdr = &partd->_impl_use.part_hdr;

                len     = udf_rw32(parthdr->unalloc_space_table.len);
                if (len) {
                        printf("UDF mount: space tables not supported\n");
                        return EROFS;
                }
        }

        /* freed space map */
        for (phys_part = 0; phys_part < UDF_PARTITIONS; phys_part++) {
                partd = ump->partitions[phys_part];
                if (partd == NULL)
                        continue;
                parthdr = &partd->_impl_use.part_hdr;

                /* freed space map */
                lb_num  = udf_rw32(partd->start_loc);
                lb_num += udf_rw32(parthdr->freed_space_bitmap.lb_num);
                len     = udf_rw32(parthdr->freed_space_bitmap.len);
                if (len == 0)
                        continue;

                DPRINTF(VOLUMES, ("Read unalloc. space bitmap %d\n", lb_num));
                error = udf_read_phys_dscr(ump, lb_num, M_UDFVOLD, &dscr);
                if (!error && dscr) {
                        /* analyse */
                        dscr_type = udf_rw16(dscr->tag.id);
                        if (dscr_type == TAGID_SPACE_BITMAP) {
                                DPRINTF(VOLUMES, ("Accepting space bitmap\n"));
                                ump->part_freed_dscr[phys_part] = &dscr->sbd;

                                /* fill in ump->part_freed_bits */
                                bitmap = &ump->part_unalloc_bits[phys_part];
                                bitmap->blob  = (uint8_t *) dscr;
                                bitmap->bits  = dscr->sbd.data;
                                bitmap->max_offset = udf_rw32(dscr->sbd.num_bits);
                                bitmap->pages = NULL;   /* TODO */
                                bitmap->data_pos     = 0;
                                bitmap->metadata_pos = 0;
                        } else {
                                free(dscr, M_UDFVOLD);

                                printf( "UDF mount: error reading freed  "
                                        "space bitmap\n");
                                return EROFS;
                        }
                } else {
                        /* blank not allowed */
                        printf("UDF mount: blank freed space bitmap\n");
                        return EROFS;
                }
        }

        /* freed space table (not supported) */
        for (phys_part = 0; phys_part < UDF_PARTITIONS; phys_part++) {
                partd = ump->partitions[phys_part];
                if (partd == NULL)
                        continue;
                parthdr = &partd->_impl_use.part_hdr;

                len     = udf_rw32(parthdr->freed_space_table.len);
                if (len) {
                        printf("UDF mount: space tables not supported\n");
                        return EROFS;
                }
        }

        return 0;
}


/* TODO implement async writeout */
int
udf_write_physical_partition_spacetables(struct udf_mount *ump, int waitfor)
{
        union dscrptr        *dscr;
        /* struct udf_args *args = &ump->mount_args; */
        struct part_desc     *partd;
        struct part_hdr_desc *parthdr;
        uint32_t phys_part;
        uint32_t lb_num, len, ptov;
        int error_all, error;

        error_all = 0;
        /* unallocated space map */
        for (phys_part = 0; phys_part < UDF_PARTITIONS; phys_part++) {
                partd = ump->partitions[phys_part];
                if (partd == NULL)
                        continue;
                parthdr = &partd->_impl_use.part_hdr;

                ptov   = udf_rw32(partd->start_loc);
                lb_num = udf_rw32(parthdr->unalloc_space_bitmap.lb_num);
                len    = udf_rw32(parthdr->unalloc_space_bitmap.len);
                if (len == 0)
                        continue;

                DPRINTF(VOLUMES, ("Write unalloc. space bitmap %d\n",
                        lb_num + ptov));
                dscr = (union dscrptr *) ump->part_unalloc_dscr[phys_part];

                /* force a sane minimum for descriptors CRC length */
                /* see UDF 2.3.1.2 and 2.3.8.1 */
                KASSERT(udf_rw16(dscr->sbd.tag.id) == TAGID_SPACE_BITMAP);
                if (udf_rw16(dscr->sbd.tag.desc_crc_len) == 0)
                        dscr->sbd.tag.desc_crc_len = udf_rw16(8);

                /* write out space bitmap */
                error = udf_write_phys_dscr_sync(ump, NULL, UDF_C_DSCR,
                                (union dscrptr *) dscr,
                                ptov + lb_num, lb_num);
                if (error) {
                        DPRINTF(VOLUMES, ("\tfailed!! (error %d)\n", error));
                        error_all = error;
                }
        }

        /* freed space map */
        for (phys_part = 0; phys_part < UDF_PARTITIONS; phys_part++) {
                partd = ump->partitions[phys_part];
                if (partd == NULL)
                        continue;
                parthdr = &partd->_impl_use.part_hdr;

                /* freed space map */
                ptov   = udf_rw32(partd->start_loc);
                lb_num = udf_rw32(parthdr->freed_space_bitmap.lb_num);
                len    = udf_rw32(parthdr->freed_space_bitmap.len);
                if (len == 0)
                        continue;

                DPRINTF(VOLUMES, ("Write freed space bitmap %d\n",
                        lb_num + ptov));
                dscr = (union dscrptr *) ump->part_freed_dscr[phys_part];

                /* force a sane minimum for descriptors CRC length */
                /* see UDF 2.3.1.2 and 2.3.8.1 */
                KASSERT(udf_rw16(dscr->sbd.tag.id) == TAGID_SPACE_BITMAP);
                if (udf_rw16(dscr->sbd.tag.desc_crc_len) == 0)
                        dscr->sbd.tag.desc_crc_len = udf_rw16(8);

                /* write out space bitmap */
                error = udf_write_phys_dscr_sync(ump, NULL, UDF_C_DSCR,
                                (union dscrptr *) dscr,
                                ptov + lb_num, lb_num);
                if (error) {
                        DPRINTF(VOLUMES, ("\tfailed!! (error %d)\n", error));
                        error_all = error;
                }
        }

        return error_all;
}


static int
udf_read_metadata_partition_spacetable(struct udf_mount *ump)
{
        struct udf_node      *bitmap_node;
        union dscrptr        *dscr;
        struct udf_bitmap    *bitmap;
        uint64_t inflen;
        int error, dscr_type;

        bitmap_node = ump->metadatabitmap_node;

        /* only read in when metadata bitmap node is read in */
        if (bitmap_node == NULL)
                return 0;

        if (bitmap_node->fe) {
                inflen = udf_rw64(bitmap_node->fe->inf_len);
        } else {
                KASSERT(bitmap_node->efe);
                inflen = udf_rw64(bitmap_node->efe->inf_len);
        }

        DPRINTF(VOLUMES, ("Reading metadata space bitmap for "
                "%"PRIu64" bytes\n", inflen));

        /* allocate space for bitmap */
        dscr = malloc(inflen, M_UDFVOLD, M_WAITOK);
        if (!dscr)
                return ENOMEM;

        /* set vnode type to regular file or we can't read from it! */
        bitmap_node->vnode->v_type = VREG;

        /* read in complete metadata bitmap file */
        error = vn_rdwr(UIO_READ, bitmap_node->vnode,
                        dscr,
                        inflen, 0,
                        UIO_SYSSPACE,
                        IO_SYNC | IO_ALTSEMANTICS, FSCRED,
                        NULL, NULL);
        if (error) {
                DPRINTF(VOLUMES, ("Error reading metadata space bitmap\n"));
                goto errorout;
        }

        /* analyse */
        dscr_type = udf_rw16(dscr->tag.id);
        if (dscr_type == TAGID_SPACE_BITMAP) {
                DPRINTF(VOLUMES, ("Accepting metadata space bitmap\n"));
                ump->metadata_unalloc_dscr = &dscr->sbd;

                /* fill in bitmap bits */
                bitmap = &ump->metadata_unalloc_bits;
                bitmap->blob  = (uint8_t *) dscr;
                bitmap->bits  = dscr->sbd.data;
                bitmap->max_offset = udf_rw32(dscr->sbd.num_bits);
                bitmap->pages = NULL;   /* TODO */
                bitmap->data_pos     = 0;
                bitmap->metadata_pos = 0;
        } else {
                DPRINTF(VOLUMES, ("No valid bitmap found!\n"));
                goto errorout;
        }

        return 0;

errorout:
        free(dscr, M_UDFVOLD);
        printf( "UDF mount: error reading unallocated "
                "space bitmap for metadata partition\n");
        return EROFS;
}


int
udf_write_metadata_partition_spacetable(struct udf_mount *ump, int waitfor)
{
        struct udf_node      *bitmap_node;
        union dscrptr        *dscr;
        uint64_t new_inflen;
        int dummy, error;

        bitmap_node = ump->metadatabitmap_node;

        /* only write out when metadata bitmap node is known */
        if (bitmap_node == NULL)
                return 0;

        if (!bitmap_node->fe) {
                KASSERT(bitmap_node->efe);
        }

        /* reduce length to zero */
        dscr = (union dscrptr *) ump->metadata_unalloc_dscr;
        new_inflen = udf_tagsize(dscr, 1);

        DPRINTF(VOLUMES, ("Resize and write out metadata space bitmap "
                " for %"PRIu64" bytes\n", new_inflen));

        error = udf_resize_node(bitmap_node, new_inflen, &dummy);
        if (error)
                printf("Error resizing metadata space bitmap\n");

        error = vn_rdwr(UIO_WRITE, bitmap_node->vnode,
                        dscr,
                        new_inflen, 0,
                        UIO_SYSSPACE,
                        IO_ALTSEMANTICS, FSCRED,
                        NULL, NULL);

        bitmap_node->i_flags |= IN_MODIFIED;
        error = vflushbuf(bitmap_node->vnode, FSYNC_WAIT);
        if (error == 0)
                error = VOP_FSYNC(bitmap_node->vnode,
                                FSCRED, FSYNC_WAIT, 0, 0);

        if (error)
                printf( "Error writing out metadata partition unalloced "
                        "space bitmap!\n");

        return error;
}


/* --------------------------------------------------------------------- */

/*
 * Checks if ump's vds information is correct and complete
 */

int
udf_process_vds(struct udf_mount *ump) {
        union udf_pmap *mapping;
        /* struct udf_args *args = &ump->mount_args; */
        struct logvol_int_desc *lvint;
        struct udf_logvol_info *lvinfo;
        uint32_t n_pm;
        uint8_t *pmap_pos;
        char *domain_name, *map_name;
        const char *check_name;
        char bits[128];
        int pmap_stype, pmap_size;
        int pmap_type, log_part, phys_part, raw_phys_part, maps_on;
        int n_phys, n_virt, n_spar, n_meta;
        int len;

        if (ump == NULL)
                return ENOENT;

        /* we need at least an anchor (trivial, but for safety) */
        if (ump->anchors[0] == NULL)
                return EINVAL;

        /* we need at least one primary and one logical volume descriptor */
        if ((ump->primary_vol == NULL) || (ump->logical_vol) == NULL)
                return EINVAL;

        /* we need at least one partition descriptor */
        if (ump->partitions[0] == NULL)
                return EINVAL;

        /* check logical volume sector size verses device sector size */
        if (udf_rw32(ump->logical_vol->lb_size) != ump->discinfo.sector_size) {
                printf("UDF mount: format violation, lb_size != sector size\n");
                return EINVAL;
        }

        /* check domain name */
        domain_name = ump->logical_vol->domain_id.id;
        if (strncmp(domain_name, "*OSTA UDF Compliant", 20)) {
                printf("mount_udf: disc not OSTA UDF Compliant, aborting\n");
                return EINVAL;
        }

        /* retrieve logical volume integrity sequence */
        (void)udf_retrieve_lvint(ump);

        /*
         * We need at least one logvol integrity descriptor recorded.  Note
         * that its OK to have an open logical volume integrity here. The VAT
         * will close/update the integrity.
         */
        if (ump->logvol_integrity == NULL)
                return EINVAL;

        /* process derived structures */
        n_pm   = udf_rw32(ump->logical_vol->n_pm);   /* num partmaps         */
        lvint  = ump->logvol_integrity;
        lvinfo = (struct udf_logvol_info *) (&lvint->tables[2 * n_pm]);
        ump->logvol_info = lvinfo;

        /* TODO check udf versions? */

        /*
         * check logvol mappings: effective virt->log partmap translation
         * check and recording of the mapping results. Saves expensive
         * strncmp() in tight places.
         */
        DPRINTF(VOLUMES, ("checking logvol mappings\n"));
        n_pm = udf_rw32(ump->logical_vol->n_pm);   /* num partmaps         */
        pmap_pos =  ump->logical_vol->maps;

        if (n_pm > UDF_PMAPS) {
                printf("UDF mount: too many mappings\n");
                return EINVAL;
        }

        /* count types and set partition numbers */
        ump->data_part = ump->node_part = ump->fids_part = 0;
        n_phys = n_virt = n_spar = n_meta = 0;
        for (log_part = 0; log_part < n_pm; log_part++) {
                mapping = (union udf_pmap *) pmap_pos;
                pmap_stype = pmap_pos[0];
                pmap_size  = pmap_pos[1];
                switch (pmap_stype) {
                case 1: /* physical mapping */
                        /* volseq    = udf_rw16(mapping->pm1.vol_seq_num); */
                        raw_phys_part = udf_rw16(mapping->pm1.part_num);
                        pmap_type = UDF_VTOP_TYPE_PHYS;
                        n_phys++;
                        ump->data_part = log_part;
                        ump->node_part = log_part;
                        ump->fids_part = log_part;
                        break;
                case 2: /* virtual/sparable/meta mapping */
                        map_name  = mapping->pm2.part_id.id;
                        /* volseq  = udf_rw16(mapping->pm2.vol_seq_num); */
                        raw_phys_part = udf_rw16(mapping->pm2.part_num);
                        pmap_type = UDF_VTOP_TYPE_UNKNOWN;
                        len = UDF_REGID_ID_SIZE;

                        check_name = "*UDF Virtual Partition";
                        if (strncmp(map_name, check_name, len) == 0) {
                                pmap_type = UDF_VTOP_TYPE_VIRT;
                                n_virt++;
                                ump->node_part = log_part;
                                break;
                        }
                        check_name = "*UDF Sparable Partition";
                        if (strncmp(map_name, check_name, len) == 0) {
                                pmap_type = UDF_VTOP_TYPE_SPARABLE;
                                n_spar++;
                                ump->data_part = log_part;
                                ump->node_part = log_part;
                                ump->fids_part = log_part;
                                break;
                        }
                        check_name = "*UDF Metadata Partition";
                        if (strncmp(map_name, check_name, len) == 0) {
                                pmap_type = UDF_VTOP_TYPE_META;
                                n_meta++;
                                ump->node_part = log_part;
                                ump->fids_part = log_part;
                                break;
                        }
                        break;
                default:
                        return EINVAL;
                }

                /*
                 * BUGALERT: some rogue implementations use random physical
                 * partition numbers to break other implementations so lookup
                 * the number.
                 */
                phys_part = udf_find_raw_phys(ump, raw_phys_part);

                DPRINTF(VOLUMES, ("\t%d -> %d(%d) type %d\n", log_part,
                    raw_phys_part, phys_part, pmap_type));

                if (phys_part == UDF_PARTITIONS)
                        return EINVAL;
                if (pmap_type == UDF_VTOP_TYPE_UNKNOWN)
                        return EINVAL;

                ump->vtop   [log_part] = phys_part;
                ump->vtop_tp[log_part] = pmap_type;

                pmap_pos += pmap_size;
        }
        /* not winning the beauty contest */
        ump->vtop_tp[UDF_VTOP_RAWPART] = UDF_VTOP_TYPE_RAW;

        /* test some basic UDF assertions/requirements */
        if ((n_virt > 1) || (n_spar > 1) || (n_meta > 1))
                return EINVAL;

        if (n_virt) {
                if ((n_phys == 0) || n_spar || n_meta)
                        return EINVAL;
        }
        if (n_spar + n_phys == 0)
                return EINVAL;

        /* select allocation type for each logical partition */
        for (log_part = 0; log_part < n_pm; log_part++) {
                maps_on = ump->vtop[log_part];
                switch (ump->vtop_tp[log_part]) {
                case UDF_VTOP_TYPE_PHYS :
                        assert(maps_on == log_part);
                        ump->vtop_alloc[log_part] = UDF_ALLOC_SPACEMAP;
                        break;
                case UDF_VTOP_TYPE_VIRT :
                        ump->vtop_alloc[log_part] = UDF_ALLOC_VAT;
                        ump->vtop_alloc[maps_on]  = UDF_ALLOC_SEQUENTIAL;
                        break;
                case UDF_VTOP_TYPE_SPARABLE :
                        assert(maps_on == log_part);
                        ump->vtop_alloc[log_part] = UDF_ALLOC_SPACEMAP;
                        break;
                case UDF_VTOP_TYPE_META :
                        ump->vtop_alloc[log_part] = UDF_ALLOC_METABITMAP;
                        if (ump->discinfo.mmc_cur & MMC_CAP_PSEUDOOVERWRITE) {
                                /* special case for UDF 2.60 */
                                ump->vtop_alloc[log_part] = UDF_ALLOC_METASEQUENTIAL;
                                ump->vtop_alloc[maps_on]  = UDF_ALLOC_SEQUENTIAL;
                        }
                        break;
                default:
                        panic("bad allocation type in udf's ump->vtop\n");
                }
        }

        /* determine logical volume open/closure actions */
        if (n_virt) {
                ump->lvopen  = 0;
                if (ump->discinfo.last_session_state == MMC_STATE_EMPTY)
                        ump->lvopen |= UDF_OPEN_SESSION ;
                ump->lvclose = UDF_WRITE_VAT;
                if (ump->mount_args.udfmflags & UDFMNT_CLOSESESSION)
                        ump->lvclose |= UDF_CLOSE_SESSION;
        } else {
                /* `normal' rewritable or non sequential media */
                ump->lvopen  = UDF_WRITE_LVINT;
                ump->lvclose = UDF_WRITE_LVINT;
                if ((ump->discinfo.mmc_cur & MMC_CAP_REWRITABLE) == 0)
                        ump->lvopen  |=  UDF_APPENDONLY_LVINT;
                if ((ump->discinfo.mmc_cur & MMC_CAP_PSEUDOOVERWRITE))
                        ump->lvopen  &= ~UDF_APPENDONLY_LVINT;
        }

        /*
         * Determine scheduler error behaviour. For virtual partitions, update
         * the trackinfo; for sparable partitions replace a whole block on the
         * sparable table. Always requeue.
         */
        ump->lvreadwrite = 0;
        if (n_virt)
                ump->lvreadwrite = UDF_UPDATE_TRACKINFO;
        if (n_spar)
                ump->lvreadwrite = UDF_REMAP_BLOCK;

        /*
         * Select our scheduler
         */
        ump->strategy = &udf_strat_rmw;
        if (n_virt || (ump->discinfo.mmc_cur & MMC_CAP_PSEUDOOVERWRITE))
                ump->strategy = &udf_strat_sequential;
        if ((ump->discinfo.mmc_class == MMC_CLASS_DISC) ||
                (ump->discinfo.mmc_class == MMC_CLASS_UNKN))
                        ump->strategy = &udf_strat_direct;
        if (n_spar)
                ump->strategy = &udf_strat_rmw;

#if 0
        /* read-only access won't benefit from the other schedulers */
        if (ump->vfs_mountp->mnt_flag & MNT_RDONLY)
                ump->strategy = &udf_strat_direct;
#endif

        /* print results */
        DPRINTF(VOLUMES, ("\tdata partition    %d\n", ump->data_part));
        DPRINTF(VOLUMES, ("\t\talloc scheme %d\n", ump->vtop_alloc[ump->data_part]));
        DPRINTF(VOLUMES, ("\tnode partition    %d\n", ump->node_part));
        DPRINTF(VOLUMES, ("\t\talloc scheme %d\n", ump->vtop_alloc[ump->node_part]));
        DPRINTF(VOLUMES, ("\tfids partition    %d\n", ump->fids_part));
        DPRINTF(VOLUMES, ("\t\talloc scheme %d\n", ump->vtop_alloc[ump->fids_part]));

        snprintb(bits, sizeof(bits), UDFLOGVOL_BITS, ump->lvopen);
        DPRINTF(VOLUMES, ("\tactions on logvol open  %s\n", bits));
        snprintb(bits, sizeof(bits), UDFLOGVOL_BITS, ump->lvclose);
        DPRINTF(VOLUMES, ("\tactions on logvol close %s\n", bits));
        snprintb(bits, sizeof(bits), UDFONERROR_BITS, ump->lvreadwrite);
        DPRINTF(VOLUMES, ("\tactions on logvol errors %s\n", bits));

        DPRINTF(VOLUMES, ("\tselected scheduler `%s`\n",
                (ump->strategy == &udf_strat_direct) ? "Direct" :
                (ump->strategy == &udf_strat_sequential) ? "Sequential" :
                (ump->strategy == &udf_strat_rmw) ? "RMW" : "UNKNOWN!"));

        /* signal its OK for now */
        return 0;
}

/* --------------------------------------------------------------------- */

/*
 * Update logical volume name in all structures that keep a record of it. We
 * use memmove since each of them might be specified as a source.
 *
 * Note that it doesn't update the VAT structure!
 */

static void
udf_update_logvolname(struct udf_mount *ump, char *logvol_id)
{
        struct logvol_desc     *lvd = NULL;
        struct fileset_desc    *fsd = NULL;
        struct udf_lv_info     *lvi = NULL;

        DPRINTF(VOLUMES, ("Updating logical volume name\n"));
        lvd = ump->logical_vol;
        fsd = ump->fileset_desc;
        if (ump->implementation)
                lvi = &ump->implementation->_impl_use.lv_info;

        /* logvol's id might be specified as original so use memmove here */
        memmove(lvd->logvol_id, logvol_id, 128);
        if (fsd)
                memmove(fsd->logvol_id, logvol_id, 128);
        if (lvi)
                memmove(lvi->logvol_id, logvol_id, 128);
}

/* --------------------------------------------------------------------- */

void
udf_inittag(struct udf_mount *ump, struct desc_tag *tag, int tagid,
        uint32_t sector)
{
        assert(ump->logical_vol);

        tag->id                 = udf_rw16(tagid);
        tag->descriptor_ver     = ump->logical_vol->tag.descriptor_ver;
        tag->cksum              = 0;
        tag->reserved           = 0;
        tag->serial_num         = ump->logical_vol->tag.serial_num;
        tag->tag_loc            = udf_rw32(sector);
}


uint64_t
udf_advance_uniqueid(struct udf_mount *ump)
{
        uint64_t unique_id;

        mutex_enter(&ump->logvol_mutex);
        unique_id = udf_rw64(ump->logvol_integrity->lvint_next_unique_id);
        if (unique_id < 0x10)
                unique_id = 0x10;
        ump->logvol_integrity->lvint_next_unique_id = udf_rw64(unique_id + 1);
        mutex_exit(&ump->logvol_mutex);

        return unique_id;
}


static void
udf_adjust_filecount(struct udf_node *udf_node, int sign)
{
        struct udf_mount *ump = udf_node->ump;
        uint32_t num_dirs, num_files;
        int udf_file_type;

        /* get file type */
        if (udf_node->fe) {
                udf_file_type = udf_node->fe->icbtag.file_type;
        } else {
                udf_file_type = udf_node->efe->icbtag.file_type;
        }

        /* adjust file count */
        mutex_enter(&ump->allocate_mutex);
        if (udf_file_type == UDF_ICB_FILETYPE_DIRECTORY) {
                num_dirs = udf_rw32(ump->logvol_info->num_directories);
                ump->logvol_info->num_directories =
                        udf_rw32((num_dirs + sign));
        } else {
                num_files = udf_rw32(ump->logvol_info->num_files);
                ump->logvol_info->num_files =
                        udf_rw32((num_files + sign));
        }
        mutex_exit(&ump->allocate_mutex);
}


void
udf_osta_charset(struct charspec *charspec)
{
        memset(charspec, 0, sizeof(struct charspec));
        charspec->type = 0;
        strcpy((char *) charspec->inf, "OSTA Compressed Unicode");
}


/* first call udf_set_regid and then the suffix */
void
udf_set_regid(struct regid *regid, char const *name)
{
        memset(regid, 0, sizeof(struct regid));
        regid->flags    = 0;            /* not dirty and not protected */
        strcpy((char *) regid->id, name);
}


void
udf_add_domain_regid(struct udf_mount *ump, struct regid *regid)
{
        uint16_t *ver;

        ver  = (uint16_t *) regid->id_suffix;
        *ver = ump->logvol_info->min_udf_readver;
}


void
udf_add_udf_regid(struct udf_mount *ump, struct regid *regid)
{
        uint16_t *ver;

        ver  = (uint16_t *) regid->id_suffix;
        *ver = ump->logvol_info->min_udf_readver;

        regid->id_suffix[2] = 4;        /* unix */
        regid->id_suffix[3] = 8;        /* NetBSD */
}


void
udf_add_impl_regid(struct udf_mount *ump, struct regid *regid)
{
        regid->id_suffix[0] = 4;        /* unix */
        regid->id_suffix[1] = 8;        /* NetBSD */
}


void
udf_add_app_regid(struct udf_mount *ump, struct regid *regid)
{
        regid->id_suffix[0] = APP_VERSION_MAIN;
        regid->id_suffix[1] = APP_VERSION_SUB;
}

static int
udf_create_parentfid(struct udf_mount *ump, struct fileid_desc *fid,
        struct long_ad *parent, uint64_t unique_id)
{
        /* the size of an empty FID is 38 but needs to be a multiple of 4 */
        int fidsize = 40;

        udf_inittag(ump, &fid->tag, TAGID_FID, udf_rw32(parent->loc.lb_num));
        fid->file_version_num = udf_rw16(1);    /* UDF 2.3.4.1 */
        fid->file_char = UDF_FILE_CHAR_DIR | UDF_FILE_CHAR_PAR;
        fid->icb = *parent;
        fid->icb.longad_uniqueid = udf_rw32((uint32_t) unique_id);
        fid->tag.desc_crc_len = udf_rw16(fidsize - UDF_DESC_TAG_LENGTH);
        (void) udf_validate_tag_and_crc_sums((union dscrptr *) fid);

        return fidsize;
}

/* --------------------------------------------------------------------- */

/*
 * Extended attribute support. UDF knows of 3 places for extended attributes:
 *
 * (a) inside the file's (e)fe in the length of the extended attribute area
 * before the allocation descriptors/filedata
 *
 * (b) in a file referenced by (e)fe->ext_attr_icb and
 *
 * (c) in the e(fe)'s associated stream directory that can hold various
 * sub-files. In the stream directory a few fixed named subfiles are reserved
 * for NT/Unix ACL's and OS/2 attributes.
 *
 * NOTE: Extended attributes are read randomly but always written
 * *atomically*. For ACL's this interface is probably different but not known
 * to me yet.
 *
 * Order of extended attributes in a space:
 *   ECMA 167 EAs
 *   Non block aligned Implementation Use EAs
 *   Block aligned Implementation Use EAs
 *   Application Use EAs
 */

static int
udf_impl_extattr_check(struct impl_extattr_entry *implext)
{
        uint16_t   *spos;

        if (strncmp(implext->imp_id.id, "*UDF", 4) == 0) {
                /* checksum valid? */
                DPRINTF(EXTATTR, ("checking UDF impl. attr checksum\n"));
                spos = (uint16_t *) implext->data;
                if (udf_rw16(*spos) != udf_ea_cksum((uint8_t *) implext))
                        return EINVAL;
        }
        return 0;
}

static void
udf_calc_impl_extattr_checksum(struct impl_extattr_entry *implext)
{
        uint16_t   *spos;

        if (strncmp(implext->imp_id.id, "*UDF", 4) == 0) {
                /* set checksum */
                spos = (uint16_t *) implext->data;
                *spos = udf_rw16(udf_ea_cksum((uint8_t *) implext));
        }
}


int
udf_extattr_search_intern(struct udf_node *node,
        uint32_t sattr, char const *sattrname,
        uint32_t *offsetp, uint32_t *lengthp)
{
        struct extattrhdr_desc    *eahdr;
        struct extattr_entry      *attrhdr;
        struct impl_extattr_entry *implext;
        uint32_t    offset, a_l, sector_size;
         int32_t    l_ea;
        uint8_t    *pos;
        int         error;

        /* get mountpoint */
        sector_size = node->ump->discinfo.sector_size;

        /* get information from fe/efe */
        if (node->fe) {
                l_ea  = udf_rw32(node->fe->l_ea);
                eahdr = (struct extattrhdr_desc *) node->fe->data;
        } else {
                assert(node->efe);
                l_ea  = udf_rw32(node->efe->l_ea);
                eahdr = (struct extattrhdr_desc *) node->efe->data;
        }

        /* something recorded here? */
        if (l_ea == 0)
                return ENOENT;

        /* check extended attribute tag; what to do if it fails? */
        error = udf_check_tag(eahdr);
        if (error)
                return EINVAL;
        if (udf_rw16(eahdr->tag.id) != TAGID_EXTATTR_HDR)
                return EINVAL;
        error = udf_check_tag_payload(eahdr, sizeof(struct extattrhdr_desc));
        if (error)
                return EINVAL;

        DPRINTF(EXTATTR, ("Found %d bytes of extended attributes\n", l_ea));

        /* looking for Ecma-167 attributes? */
        offset = sizeof(struct extattrhdr_desc);

        /* looking for either implementation use or application use */
        if (sattr == 2048) {                            /* [4/48.10.8] */
                offset = udf_rw32(eahdr->impl_attr_loc);
                if (offset == UDF_IMPL_ATTR_LOC_NOT_PRESENT)
                        return ENOENT;
        }
        if (sattr == 65536) {                           /* [4/48.10.9] */
                offset = udf_rw32(eahdr->appl_attr_loc);
                if (offset == UDF_APPL_ATTR_LOC_NOT_PRESENT)
                        return ENOENT;
        }

        /* paranoia check offset and l_ea */
        if (l_ea + offset >= sector_size - sizeof(struct extattr_entry))
                return EINVAL;

        DPRINTF(EXTATTR, ("Starting at offset %d\n", offset));

        /* find our extended attribute  */
        l_ea -= offset;
        pos = (uint8_t *) eahdr + offset;

        while (l_ea >= sizeof(struct extattr_entry)) {
                DPRINTF(EXTATTR, ("%d extended attr bytes left\n", l_ea));
                attrhdr = (struct extattr_entry *) pos;
                implext = (struct impl_extattr_entry *) pos;

                /* get complete attribute length and check for roque values */
                a_l = udf_rw32(attrhdr->a_l);
                DPRINTF(EXTATTR, ("attribute %d:%d, len %d/%d\n",
                                udf_rw32(attrhdr->type),
                                attrhdr->subtype, a_l, l_ea));
                if ((a_l == 0) || (a_l > l_ea))
                        return EINVAL;

                if (udf_rw32(attrhdr->type) != sattr)
                        goto next_attribute;

                /* we might have found it! */
                if (udf_rw32(attrhdr->type) < 2048) {   /* Ecma-167 attribute */
                        *offsetp = offset;
                        *lengthp = a_l;
                        return 0;               /* success */
                }

                /*
                 * Implementation use and application use extended attributes
                 * have a name to identify. They share the same structure only
                 * UDF implementation use extended attributes have a checksum
                 * we need to check
                 */

                DPRINTF(EXTATTR, ("named attribute %s\n", implext->imp_id.id));
                if (strcmp(implext->imp_id.id, sattrname) == 0) {
                        /* we have found our appl/implementation attribute */
                        *offsetp = offset;
                        *lengthp = a_l;
                        return 0;               /* success */
                }

next_attribute:
                /* next attribute */
                pos    += a_l;
                l_ea   -= a_l;
                offset += a_l;
        }
        /* not found */
        return ENOENT;
}


static void
udf_extattr_insert_internal(struct udf_mount *ump, union dscrptr *dscr,
        struct extattr_entry *extattr)
{
        struct file_entry      *fe;
        struct extfile_entry   *efe;
        struct extattrhdr_desc *extattrhdr;
        struct impl_extattr_entry *implext;
        uint32_t impl_attr_loc, appl_attr_loc, l_ea, a_l, exthdr_len;
        uint32_t *l_eap, l_ad;
        uint16_t *spos;
        uint8_t *bpos, *data;

        if (udf_rw16(dscr->tag.id) == TAGID_FENTRY) {
                fe    = &dscr->fe;
                data  = fe->data;
                l_eap = &fe->l_ea;
                l_ad  = udf_rw32(fe->l_ad);
        } else if (udf_rw16(dscr->tag.id) == TAGID_EXTFENTRY) {
                efe   = &dscr->efe;
                data  = efe->data;
                l_eap = &efe->l_ea;
                l_ad  = udf_rw32(efe->l_ad);
        } else {
                panic("Bad tag passed to udf_extattr_insert_internal");
        }

        /* can't append already written to file descriptors yet */
        assert(l_ad == 0);
        __USE(l_ad);

        /* should have a header! */
        extattrhdr = (struct extattrhdr_desc *) data;
        l_ea = udf_rw32(*l_eap);
        if (l_ea == 0) {
                /* create empty extended attribute header */
                exthdr_len = sizeof(struct extattrhdr_desc);

                udf_inittag(ump, &extattrhdr->tag, TAGID_EXTATTR_HDR,
                        /* loc */ 0);
                extattrhdr->impl_attr_loc = udf_rw32(exthdr_len);
                extattrhdr->appl_attr_loc = udf_rw32(exthdr_len);
                extattrhdr->tag.desc_crc_len = udf_rw16(8);

                /* record extended attribute header length */
                l_ea = exthdr_len;
                *l_eap = udf_rw32(l_ea);
        }

        /* extract locations */
        impl_attr_loc = udf_rw32(extattrhdr->impl_attr_loc);
        appl_attr_loc = udf_rw32(extattrhdr->appl_attr_loc);
        if (impl_attr_loc == UDF_IMPL_ATTR_LOC_NOT_PRESENT)
                impl_attr_loc = l_ea;
        if (appl_attr_loc == UDF_IMPL_ATTR_LOC_NOT_PRESENT)
                appl_attr_loc = l_ea;

        /* Ecma 167 EAs */
        if (udf_rw32(extattr->type) < 2048) {
                assert(impl_attr_loc == l_ea);
                assert(appl_attr_loc == l_ea);
        }

        /* implementation use extended attributes */
        if (udf_rw32(extattr->type) == 2048) {
                assert(appl_attr_loc == l_ea);

                /* calculate and write extended attribute header checksum */
                implext = (struct impl_extattr_entry *) extattr;
                assert(udf_rw32(implext->iu_l) == 4);   /* [UDF 3.3.4.5] */
                spos = (uint16_t *) implext->data;
                *spos = udf_rw16(udf_ea_cksum((uint8_t *) implext));
        }

        /* application use extended attributes */
        assert(udf_rw32(extattr->type) != 65536);
        assert(appl_attr_loc == l_ea);

        /* append the attribute at the end of the current space */
        bpos = data + udf_rw32(*l_eap);
        a_l  = udf_rw32(extattr->a_l);

        /* update impl. attribute locations */
        if (udf_rw32(extattr->type) < 2048) {
                impl_attr_loc = l_ea + a_l;
                appl_attr_loc = l_ea + a_l;
        }
        if (udf_rw32(extattr->type) == 2048) {
                appl_attr_loc = l_ea + a_l;
        }

        /* copy and advance */
        memcpy(bpos, extattr, a_l);
        l_ea += a_l;
        *l_eap = udf_rw32(l_ea);

        /* do the `dance` again backwards */
        if (udf_rw16(ump->logical_vol->tag.descriptor_ver) != 2) {
                if (impl_attr_loc == l_ea)
                        impl_attr_loc = UDF_IMPL_ATTR_LOC_NOT_PRESENT;
                if (appl_attr_loc == l_ea)
                        appl_attr_loc = UDF_APPL_ATTR_LOC_NOT_PRESENT;
        }

        /* store offsets */
        extattrhdr->impl_attr_loc = udf_rw32(impl_attr_loc);
        extattrhdr->appl_attr_loc = udf_rw32(appl_attr_loc);
}


/* --------------------------------------------------------------------- */

static int
udf_update_lvid_from_vat_extattr(struct udf_node *vat_node)
{
        struct udf_mount       *ump;
        struct udf_logvol_info *lvinfo;
        struct impl_extattr_entry     *implext;
        struct vatlvext_extattr_entry  lvext;
        const char *extstr = "*UDF VAT LVExtension";
        uint64_t    vat_uniqueid;
        uint32_t    offset, a_l;
        uint8_t    *ea_start, *lvextpos;
        int         error;

        /* get mountpoint and lvinfo */
        ump    = vat_node->ump;
        lvinfo = ump->logvol_info;

        /* get information from fe/efe */
        if (vat_node->fe) {
                vat_uniqueid = udf_rw64(vat_node->fe->unique_id);
                ea_start     = vat_node->fe->data;
        } else {
                vat_uniqueid = udf_rw64(vat_node->efe->unique_id);
                ea_start     = vat_node->efe->data;
        }

        error = udf_extattr_search_intern(vat_node, 2048, extstr, &offset, &a_l);
        if (error)
                return error;

        implext = (struct impl_extattr_entry *) (ea_start + offset);
        error = udf_impl_extattr_check(implext);
        if (error)
                return error;

        /* paranoia */
        if (a_l != sizeof(*implext) -2 + udf_rw32(implext->iu_l) + sizeof(lvext)) {
                DPRINTF(VOLUMES, ("VAT LVExtension size doesn't compute\n"));
                return EINVAL;
        }

        /*
         * we have found our "VAT LVExtension attribute. BUT due to a
         * bug in the specification it might not be word aligned so
         * copy first to avoid panics on some machines (!!)
         */
        DPRINTF(VOLUMES, ("Found VAT LVExtension attr\n"));
        lvextpos = implext->data + udf_rw32(implext->iu_l);
        memcpy(&lvext, lvextpos, sizeof(lvext));

        /* check if it was updated the last time */
        if (udf_rw64(lvext.unique_id_chk) == vat_uniqueid) {
                lvinfo->num_files       = lvext.num_files;
                lvinfo->num_directories = lvext.num_directories;
                udf_update_logvolname(ump, lvext.logvol_id);
        } else {
                DPRINTF(VOLUMES, ("VAT LVExtension out of date\n"));
                /* replace VAT LVExt by free space EA */
                memset(implext->imp_id.id, 0, UDF_REGID_ID_SIZE);
                strcpy(implext->imp_id.id, "*UDF FreeEASpace");
                udf_calc_impl_extattr_checksum(implext);
        }

        return 0;
}


static int
udf_update_vat_extattr_from_lvid(struct udf_node *vat_node)
{
        struct udf_mount       *ump;
        struct udf_logvol_info *lvinfo;
        struct impl_extattr_entry     *implext;
        struct vatlvext_extattr_entry  lvext;
        const char *extstr = "*UDF VAT LVExtension";
        uint64_t    vat_uniqueid;
        uint32_t    offset, a_l;
        uint8_t    *ea_start;
        uintptr_t   lvextpos;
        int         error;

        /* get mountpoint and lvinfo */
        ump    = vat_node->ump;
        lvinfo = ump->logvol_info;

        /* get information from fe/efe */
        if (vat_node->fe) {
                vat_uniqueid = udf_rw64(vat_node->fe->unique_id);
                ea_start     = vat_node->fe->data;
        } else {
                vat_uniqueid = udf_rw64(vat_node->efe->unique_id);
                ea_start     = vat_node->efe->data;
        }

        error = udf_extattr_search_intern(vat_node, 2048, extstr, &offset, &a_l);
        if (error)
                return error;
        /* found, it existed */

        /* paranoia */
        implext = (struct impl_extattr_entry *) (ea_start + offset);
        error = udf_impl_extattr_check(implext);
        if (error) {
                DPRINTF(VOLUMES, ("VAT LVExtension bad on update\n"));
                return error;
        }
        /* it is correct */

        /*
         * we have found our "VAT LVExtension attribute. BUT due to a
         * bug in the specification it might not be word aligned so
         * copy first to avoid panics on some machines (!!)
         */
        DPRINTF(VOLUMES, ("Updating VAT LVExtension attr\n"));
        lvextpos = (uintptr_t)implext->data + udf_rw32(implext->iu_l);

        lvext.unique_id_chk   = vat_uniqueid;
        lvext.num_files       = lvinfo->num_files;
        lvext.num_directories = lvinfo->num_directories;
        memmove(lvext.logvol_id, ump->logical_vol->logvol_id, 128);

        memcpy((void *)lvextpos, &lvext, sizeof(lvext));

        return 0;
}

/* --------------------------------------------------------------------- */

int
udf_vat_read(struct udf_node *vat_node, uint8_t *blob, int size, uint32_t offset)
{
        struct udf_mount *ump = vat_node->ump;

        if (offset + size > ump->vat_offset + ump->vat_entries * 4)
                return EINVAL;

        memcpy(blob, ump->vat_table + offset, size);
        return 0;
}

int
udf_vat_write(struct udf_node *vat_node, uint8_t *blob, int size, uint32_t offset)
{
        struct udf_mount *ump = vat_node->ump;
        uint32_t offset_high;
        uint8_t *new_vat_table;

        /* extent VAT allocation if needed */
        offset_high = offset + size;
        if (offset_high >= ump->vat_table_alloc_len) {
                /* realloc */
                new_vat_table = realloc(ump->vat_table,
                        ump->vat_table_alloc_len + UDF_VAT_CHUNKSIZE,
                        M_UDFVOLD, M_WAITOK);
                if (!new_vat_table) {
                        printf("udf_vat_write: can't extent VAT, out of mem\n");
                        return ENOMEM;
                }
                ump->vat_table = new_vat_table;
                ump->vat_table_alloc_len += UDF_VAT_CHUNKSIZE;
        }
        ump->vat_table_len = MAX(ump->vat_table_len, offset_high);

        memcpy(ump->vat_table + offset, blob, size);
        return 0;
}

/* --------------------------------------------------------------------- */

/* TODO support previous VAT location writeout */
static int
udf_update_vat_descriptor(struct udf_mount *ump)
{
        struct udf_node *vat_node = ump->vat_node;
        struct udf_logvol_info *lvinfo = ump->logvol_info;
        struct icb_tag *icbtag;
        struct udf_oldvat_tail *oldvat_tl;
        struct udf_vat *vat;
        struct regid *regid;
        uint64_t unique_id;
        uint32_t lb_size;
        uint8_t *raw_vat;
        int vat_length, impl_use_len, filetype, error;

        KASSERT(vat_node);
        KASSERT(lvinfo);
        lb_size = udf_rw32(ump->logical_vol->lb_size);

        /* get our new unique_id */
        unique_id = udf_advance_uniqueid(ump);

        /* get information from fe/efe */
        if (vat_node->fe) {
                icbtag    = &vat_node->fe->icbtag;
                vat_node->fe->unique_id = udf_rw64(unique_id);
        } else {
                icbtag = &vat_node->efe->icbtag;
                vat_node->efe->unique_id = udf_rw64(unique_id);
        }

        /* Check icb filetype! it has to be 0 or UDF_ICB_FILETYPE_VAT */
        filetype = icbtag->file_type;
        KASSERT((filetype == 0) || (filetype == UDF_ICB_FILETYPE_VAT));

        /* allocate piece to process head or tail of VAT file */
        raw_vat = malloc(lb_size, M_TEMP, M_WAITOK);

        if (filetype == 0) {
                /*
                 * Update "*UDF VAT LVExtension" extended attribute from the
                 * lvint if present.
                 */
                udf_update_vat_extattr_from_lvid(vat_node);

                /* setup identifying regid */
                oldvat_tl = (struct udf_oldvat_tail *) raw_vat;
                memset(oldvat_tl, 0, sizeof(struct udf_oldvat_tail));

                udf_set_regid(&oldvat_tl->id, "*UDF Virtual Alloc Tbl");
                udf_add_udf_regid(ump, &oldvat_tl->id);
                oldvat_tl->prev_vat = udf_rw32(0xffffffff);

                /* write out new tail of virtual allocation table file */
                error = udf_vat_write(vat_node, raw_vat,
                        sizeof(struct udf_oldvat_tail), ump->vat_entries * 4);
        } else {
                /* compose the VAT2 header */
                vat_length = sizeof(struct udf_vat);
                vat = (struct udf_vat *) raw_vat;

                error = udf_vat_read(vat_node, raw_vat, vat_length, 0);
                if (error)
                        goto errout;

                impl_use_len = udf_rw16(vat->impl_use_len);
                vat_length += impl_use_len;

                error = udf_vat_read(vat_node, raw_vat, vat_length, 0);
                if (error)
                        goto errout;

                memmove(vat->logvol_id, ump->logical_vol->logvol_id, 128);
                vat->prev_vat         = udf_rw32(0xffffffff);
                vat->num_files        = lvinfo->num_files;
                vat->num_directories  = lvinfo->num_directories;
                vat->min_udf_readver  = lvinfo->min_udf_readver;
                vat->min_udf_writever = lvinfo->min_udf_writever;
                vat->max_udf_writever = lvinfo->max_udf_writever;

                if (impl_use_len >= sizeof(struct regid)) {
                        /* insert our implementation identification */
                        memset(vat->data, 0, impl_use_len);
                        regid = (struct regid *) vat->data;
                        udf_set_regid(regid, IMPL_NAME);
                        udf_add_app_regid(ump, regid);
                } else {
                        if (impl_use_len)
                                memset(vat->data, 0, impl_use_len);
                        vat->impl_use_len = 0;
                }
                error = udf_vat_write(vat_node, raw_vat, vat_length, 0);
        }
errout:
        free(raw_vat, M_TEMP);

        return error;   /* success! */
}


int
udf_writeout_vat(struct udf_mount *ump)
{
        struct udf_node *vat_node = ump->vat_node;
        int error;

        KASSERT(vat_node);

        DPRINTF(CALL, ("udf_writeout_vat\n"));

//      mutex_enter(&ump->allocate_mutex);
        udf_update_vat_descriptor(ump);

        /* write out the VAT contents ; TODO intelligent writing */
        error = vn_rdwr(UIO_WRITE, vat_node->vnode,
                ump->vat_table, ump->vat_table_len, 0,
                UIO_SYSSPACE, 0, FSCRED, NULL, NULL);
        if (error) {
                printf("udf_writeout_vat: failed to write out VAT contents\n");
                goto out;
        }

//      mutex_exit(&ump->allocate_mutex);

        error = vflushbuf(ump->vat_node->vnode, FSYNC_WAIT);
        if (error)
                goto out;
        error = VOP_FSYNC(ump->vat_node->vnode,
                        FSCRED, FSYNC_WAIT, 0, 0);
        if (error)
                printf("udf_writeout_vat: error writing VAT node!\n");
out:
        return error;
}

/* --------------------------------------------------------------------- */

/*
 * Read in relevant pieces of VAT file and check if its indeed a VAT file
 * descriptor. If OK, read in complete VAT file.
 */

static int
udf_check_for_vat(struct udf_node *vat_node)
{
        struct udf_mount *ump;
        struct icb_tag   *icbtag;
        struct timestamp *mtime;
        struct udf_vat   *vat;
        struct udf_oldvat_tail *oldvat_tl;
        struct udf_logvol_info *lvinfo;
        uint64_t  unique_id;
        uint32_t  vat_length;
        uint32_t  vat_offset, vat_entries, vat_table_alloc_len;
        uint32_t  sector_size;
        uint32_t *raw_vat;
        uint8_t  *vat_table;
        char     *regid_name;
        int filetype;
        int error;

        /* vat_length is really 64 bits though impossible */

        DPRINTF(VOLUMES, ("Checking for VAT\n"));
        if (!vat_node)
                return ENOENT;

        /* get mount info */
        ump = vat_node->ump;
        sector_size = udf_rw32(ump->logical_vol->lb_size);

        /* check assertions */
        assert(vat_node->fe || vat_node->efe);
        assert(ump->logvol_integrity);

        /* set vnode type to regular file or we can't read from it! */
        vat_node->vnode->v_type = VREG;

        /* get information from fe/efe */
        if (vat_node->fe) {
                vat_length = udf_rw64(vat_node->fe->inf_len);
                icbtag    = &vat_node->fe->icbtag;
                mtime     = &vat_node->fe->mtime;
                unique_id = udf_rw64(vat_node->fe->unique_id);
        } else {
                vat_length = udf_rw64(vat_node->efe->inf_len);
                icbtag = &vat_node->efe->icbtag;
                mtime  = &vat_node->efe->mtime;
                unique_id = udf_rw64(vat_node->efe->unique_id);
        }

        /* Check icb filetype! it has to be 0 or UDF_ICB_FILETYPE_VAT */
        filetype = icbtag->file_type;
        if ((filetype != 0) && (filetype != UDF_ICB_FILETYPE_VAT))
                return ENOENT;

        DPRINTF(VOLUMES, ("\tPossible VAT length %d\n", vat_length));

        vat_table_alloc_len =
                ((vat_length + UDF_VAT_CHUNKSIZE-1) / UDF_VAT_CHUNKSIZE)
                        * UDF_VAT_CHUNKSIZE;

        vat_table = malloc(vat_table_alloc_len, M_UDFVOLD, M_WAITOK);
        if (vat_table == NULL) {
                printf("allocation of %d bytes failed for VAT\n",
                        vat_table_alloc_len);
                return ENOMEM;
        }

        /* allocate piece to read in head or tail of VAT file */
        raw_vat = malloc(sector_size, M_TEMP, M_WAITOK);

        /*
         * check contents of the file if its the old 1.50 VAT table format.
         * Its notoriously broken and allthough some implementations support an
         * extension as defined in the UDF 1.50 errata document, its doubtful
         * to be useable since a lot of implementations don't maintain it.
         */
        lvinfo = ump->logvol_info;

        if (filetype == 0) {
                /* definition */
                vat_offset  = 0;
                vat_entries = (vat_length-36)/4;

                /* read in tail of virtual allocation table file */
                error = vn_rdwr(UIO_READ, vat_node->vnode,
                                (uint8_t *) raw_vat,
                                sizeof(struct udf_oldvat_tail),
                                vat_entries * 4,
                                UIO_SYSSPACE, IO_SYNC | IO_NODELOCKED, FSCRED,
                                NULL, NULL);
                if (error)
                        goto out;

                /* check 1.50 VAT */
                oldvat_tl = (struct udf_oldvat_tail *) raw_vat;
                regid_name = (char *) oldvat_tl->id.id;
                error = strncmp(regid_name, "*UDF Virtual Alloc Tbl", 22);
                if (error) {
                        DPRINTF(VOLUMES, ("VAT format 1.50 rejected\n"));
                        error = ENOENT;
                        goto out;
                }

                /*
                 * update LVID from "*UDF VAT LVExtension" extended attribute
                 * if present.
                 */
                udf_update_lvid_from_vat_extattr(vat_node);
        } else {
                /* read in head of virtual allocation table file */
                error = vn_rdwr(UIO_READ, vat_node->vnode,
                                (uint8_t *) raw_vat,
                                sizeof(struct udf_vat), 0,
                                UIO_SYSSPACE, IO_SYNC | IO_NODELOCKED, FSCRED,
                                NULL, NULL);
                if (error)
                        goto out;

                /* definition */
                vat = (struct udf_vat *) raw_vat;
                vat_offset  = udf_rw16(vat->header_len);
                vat_entries = (vat_length - vat_offset)/4;

                assert(lvinfo);
                lvinfo->num_files        = vat->num_files;
                lvinfo->num_directories  = vat->num_directories;
                lvinfo->min_udf_readver  = vat->min_udf_readver;
                lvinfo->min_udf_writever = vat->min_udf_writever;
                lvinfo->max_udf_writever = vat->max_udf_writever;

                udf_update_logvolname(ump, vat->logvol_id);
        }

        /* read in complete VAT file */
        error = vn_rdwr(UIO_READ, vat_node->vnode,
                        vat_table,
                        vat_length, 0,
                        UIO_SYSSPACE, IO_SYNC | IO_NODELOCKED, FSCRED,
                        NULL, NULL);
        if (error)
                printf("read in of complete VAT file failed (error %d)\n",
                        error);
        if (error)
                goto out;

        DPRINTF(VOLUMES, ("VAT format accepted, marking it closed\n"));
        ump->logvol_integrity->lvint_next_unique_id = udf_rw64(unique_id);
        ump->logvol_integrity->integrity_type = udf_rw32(UDF_INTEGRITY_CLOSED);
        ump->logvol_integrity->time           = *mtime;

        /* if we're updating, free old allocated space */
        if (ump->vat_table)
                free(ump->vat_table, M_UDFVOLD);

        ump->vat_table_len = vat_length;
        ump->vat_table_alloc_len = vat_table_alloc_len;
        ump->vat_table   = vat_table;
        ump->vat_offset  = vat_offset;
        ump->vat_entries = vat_entries;
        ump->vat_last_free_lb = 0;              /* start at beginning */

out:
        if (error) {
                if (vat_table)
                        free(vat_table, M_UDFVOLD);
        }
        free(raw_vat, M_TEMP);

        return error;
}

/* --------------------------------------------------------------------- */

static int
udf_search_vat(struct udf_mount *ump, union udf_pmap *mapping)
{
        struct udf_node *vat_node, *accepted_vat_node;
        struct long_ad   icb_loc;
        uint32_t early_vat_loc, late_vat_loc, vat_loc;
        int error;

        /* mapping info not needed */
        mapping = mapping;

        DPRINTF(VOLUMES, ("Searching VAT\n"));

        /*
         * Start reading forward in blocks from the first possible vat
         * location. If not found in this block, start again a bit before
         * until we get a hit.
         */
        late_vat_loc = ump->last_possible_vat_location;
        early_vat_loc = MAX(late_vat_loc - 64, ump->first_possible_vat_location);

        DPRINTF(VOLUMES, ("\tfull range %d to %d\n", early_vat_loc, late_vat_loc));
        accepted_vat_node = NULL;
        do {
                vat_loc = early_vat_loc;
                DPRINTF(VOLUMES, ("\tchecking range %d to %d\n",
                        early_vat_loc, late_vat_loc));
                do {
                        DPRINTF(VOLUMES, ("\t\tChecking for VAT at sector %d\n",
                                vat_loc));
                        icb_loc.loc.part_num = udf_rw16(UDF_VTOP_RAWPART);
                        icb_loc.loc.lb_num   = udf_rw32(vat_loc);

                        error = udf_get_node(ump, &icb_loc, &vat_node,
                            LK_EXCLUSIVE);
                        if (!error) {
                                error = udf_check_for_vat(vat_node);
                                vat_node->i_flags = 0;  /* reset access */
                        }
                        if (!error) {
                                DPRINTFIF(VOLUMES, !error,
                                        ("VAT candidate accepted at %d\n",
                                         vat_loc));
                                if (accepted_vat_node)
                                        vput(accepted_vat_node->vnode);
                                accepted_vat_node = vat_node;
                                accepted_vat_node->i_flags |= IN_NO_DELETE;
                                vat_node = NULL;
                        }
                        if (vat_node)
                                vput(vat_node->vnode);
                        vat_loc++;      /* walk forward */
                } while (vat_loc <= late_vat_loc);
                if (accepted_vat_node)
                        break;

                early_vat_loc = MAX(early_vat_loc - 64, ump->first_possible_vat_location);
                late_vat_loc = MIN(early_vat_loc + 64, ump->last_possible_vat_location);
        } while (late_vat_loc > ump->first_possible_vat_location);

        /* keep our last accepted VAT node around */
        if (accepted_vat_node) {
                /* revert no delete flag again to avoid potential side effects */
                accepted_vat_node->i_flags &= ~IN_NO_DELETE;

                UDF_SET_SYSTEMFILE(accepted_vat_node->vnode);
                ump->vat_node = accepted_vat_node;
                return 0;
        }

        return error;
}

/* --------------------------------------------------------------------- */

static int
udf_read_sparables(struct udf_mount *ump, union udf_pmap *mapping)
{
        union dscrptr *dscr;
        struct part_map_spare *pms = &mapping->pms;
        uint32_t lb_num;
        int spar, error;

        /*
         * The partition mapping passed on to us specifies the information we
         * need to locate and initialise the sparable partition mapping
         * information we need.
         */

        DPRINTF(VOLUMES, ("Read sparable table\n"));
        ump->sparable_packet_size = udf_rw16(pms->packet_len);
        KASSERT(ump->sparable_packet_size >= ump->packet_size); /* XXX */

        for (spar = 0; spar < pms->n_st; spar++) {
                lb_num = pms->st_loc[spar];
                DPRINTF(VOLUMES, ("Checking for sparing table %d\n", lb_num));
                error = udf_read_phys_dscr(ump, lb_num, M_UDFVOLD, &dscr);
                if (!error && dscr) {
                        if (udf_rw16(dscr->tag.id) == TAGID_SPARING_TABLE) {
                                if (ump->sparing_table)
                                        free(ump->sparing_table, M_UDFVOLD);
                                ump->sparing_table = &dscr->spt;
                                dscr = NULL;
                                DPRINTF(VOLUMES,
                                    ("Sparing table accepted (%d entries)\n",
                                     udf_rw16(ump->sparing_table->rt_l)));
                                break;  /* we're done */
                        }
                }
                if (dscr)
                        free(dscr, M_UDFVOLD);
        }

        if (ump->sparing_table)
                return 0;

        return ENOENT;
}

/* --------------------------------------------------------------------- */

static int
udf_read_metadata_nodes(struct udf_mount *ump, union udf_pmap *mapping)
{
        struct part_map_meta *pmm = &mapping->pmm;
        struct long_ad   icb_loc;
        struct vnode *vp;
        uint16_t raw_phys_part, phys_part;
        int error;

        /*
         * BUGALERT: some rogue implementations use random physical
         * partition numbers to break other implementations so lookup
         * the number.
         */

        /* extract our allocation parameters set up on format */
        ump->metadata_alloc_unit_size     = udf_rw32(mapping->pmm.alloc_unit_size);
        ump->metadata_alignment_unit_size = udf_rw16(mapping->pmm.alignment_unit_size);
        ump->metadata_flags = mapping->pmm.flags;

        DPRINTF(VOLUMES, ("Reading in Metadata files\n"));
        raw_phys_part = udf_rw16(pmm->part_num);
        phys_part = udf_find_raw_phys(ump, raw_phys_part);

        icb_loc.loc.part_num = udf_rw16(phys_part);

        DPRINTF(VOLUMES, ("Metadata file\n"));
        icb_loc.loc.lb_num   = pmm->meta_file_lbn;
        error = udf_get_node(ump, &icb_loc, &ump->metadata_node,
            LK_EXCLUSIVE);
        if (ump->metadata_node) {
                vp = ump->metadata_node->vnode;
                UDF_SET_SYSTEMFILE(vp);
        }

        icb_loc.loc.lb_num   = pmm->meta_mirror_file_lbn;
        if (icb_loc.loc.lb_num != -1) {
                DPRINTF(VOLUMES, ("Metadata copy file\n"));
                error = udf_get_node(ump, &icb_loc, &ump->metadatamirror_node,
                    LK_EXCLUSIVE);
                if (ump->metadatamirror_node) {
                        vp = ump->metadatamirror_node->vnode;
                        UDF_SET_SYSTEMFILE(vp);
                }
        }

        icb_loc.loc.lb_num   = pmm->meta_bitmap_file_lbn;
        if (icb_loc.loc.lb_num != -1) {
                DPRINTF(VOLUMES, ("Metadata bitmap file\n"));
                error = udf_get_node(ump, &icb_loc, &ump->metadatabitmap_node,
                    LK_EXCLUSIVE);
                if (ump->metadatabitmap_node) {
                        vp = ump->metadatabitmap_node->vnode;
                        UDF_SET_SYSTEMFILE(vp);
                }
        }

        /* if we're mounting read-only we relax the requirements */
        if (ump->vfs_mountp->mnt_flag & MNT_RDONLY) {
                error = EFAULT;
                if (ump->metadata_node)
                        error = 0;
                if ((ump->metadata_node == NULL) && (ump->metadatamirror_node)) {
                        printf( "udf mount: Metadata file not readable, "
                                "substituting Metadata copy file\n");
                        ump->metadata_node = ump->metadatamirror_node;
                        ump->metadatamirror_node = NULL;
                        error = 0;
                }
        } else {
                /* mounting read/write */
                /* XXX DISABLED! metadata writing is not working yet XXX */
                if (error)
                        error = EROFS;
        }
        DPRINTFIF(VOLUMES, error, ("udf mount: failed to read "
                                   "metadata files\n"));
        return error;
}

/* --------------------------------------------------------------------- */

int
udf_read_vds_tables(struct udf_mount *ump)
{
        union udf_pmap *mapping;
        /* struct udf_args *args = &ump->mount_args; */
        uint32_t n_pm;
        uint32_t log_part;
        uint8_t *pmap_pos;
        int pmap_size;
        int error;

        /* Iterate (again) over the part mappings for locations   */
        n_pm = udf_rw32(ump->logical_vol->n_pm);   /* num partmaps         */
        pmap_pos =  ump->logical_vol->maps;

        for (log_part = 0; log_part < n_pm; log_part++) {
                mapping = (union udf_pmap *) pmap_pos;
                switch (ump->vtop_tp[log_part]) {
                case UDF_VTOP_TYPE_PHYS :
                        /* nothing */
                        break;
                case UDF_VTOP_TYPE_VIRT :
                        /* search and load VAT */
                        error = udf_search_vat(ump, mapping);
                        if (error)
                                return ENOENT;
                        break;
                case UDF_VTOP_TYPE_SPARABLE :
                        /* load one of the sparable tables */
                        error = udf_read_sparables(ump, mapping);
                        if (error)
                                return ENOENT;
                        break;
                case UDF_VTOP_TYPE_META :
                        /* load the associated file descriptors */
                        error = udf_read_metadata_nodes(ump, mapping);
                        if (error)
                                return ENOENT;
                        break;
                default:
                        break;
                }
                pmap_size  = pmap_pos[1];
                pmap_pos  += pmap_size;
        }

        /* read in and check unallocated and free space info if writing */
        if ((ump->vfs_mountp->mnt_flag & MNT_RDONLY) == 0) {
                error = udf_read_physical_partition_spacetables(ump);
                if (error)
                        return error;

                /* also read in metadata partition spacebitmap if defined */
                error = udf_read_metadata_partition_spacetable(ump);
                        return error;
        }

        return 0;
}

/* --------------------------------------------------------------------- */

int
udf_read_rootdirs(struct udf_mount *ump)
{
        union dscrptr *dscr;
        /* struct udf_args *args = &ump->mount_args; */
        struct udf_node *rootdir_node, *streamdir_node;
        struct long_ad  fsd_loc, *dir_loc;
        uint32_t lb_num, dummy;
        uint32_t fsd_len;
        int dscr_type;
        int error;

        /* TODO implement FSD reading in separate function like integrity? */
        /* get fileset descriptor sequence */
        fsd_loc = ump->logical_vol->lv_fsd_loc;
        fsd_len = udf_rw32(fsd_loc.len);

        dscr  = NULL;
        error = 0;
        while (fsd_len || error) {
                DPRINTF(VOLUMES, ("fsd_len = %d\n", fsd_len));
                /* translate fsd_loc to lb_num */
                error = udf_translate_vtop(ump, &fsd_loc, &lb_num, &dummy);
                if (error)
                        break;
                DPRINTF(VOLUMES, ("Reading FSD at lb %d\n", lb_num));
                error = udf_read_phys_dscr(ump, lb_num, M_UDFVOLD, &dscr);
                /* end markers */
                if (error || (dscr == NULL))
                        break;

                /* analyse */
                dscr_type = udf_rw16(dscr->tag.id);
                if (dscr_type == TAGID_TERM)
                        break;
                if (dscr_type != TAGID_FSD) {
                        free(dscr, M_UDFVOLD);
                        return ENOENT;
                }

                /*
                 * TODO check for multiple fileset descriptors; its only
                 * picking the last now. Also check for FSD
                 * correctness/interpretability
                 */

                /* update */
                if (ump->fileset_desc) {
                        free(ump->fileset_desc, M_UDFVOLD);
                }
                ump->fileset_desc = &dscr->fsd;
                dscr = NULL;

                /* continue to the next fsd */
                fsd_len -= ump->discinfo.sector_size;
                fsd_loc.loc.lb_num = udf_rw32(udf_rw32(fsd_loc.loc.lb_num)+1);

                /* follow up to fsd->next_ex (long_ad) if its not null */
                if (udf_rw32(ump->fileset_desc->next_ex.len)) {
                        DPRINTF(VOLUMES, ("follow up FSD extent\n"));
                        fsd_loc = ump->fileset_desc->next_ex;
                        fsd_len = udf_rw32(ump->fileset_desc->next_ex.len);
                }
        }
        if (dscr)
                free(dscr, M_UDFVOLD);

        /* there has to be one */
        if (ump->fileset_desc == NULL)
                return ENOENT;

        DPRINTF(VOLUMES, ("FSD read in fine\n"));
        DPRINTF(VOLUMES, ("Updating fsd logical volume id\n"));
        udf_update_logvolname(ump, ump->logical_vol->logvol_id);

        /*
         * Now the FSD is known, read in the rootdirectory and if one exists,
         * the system stream dir. Some files in the system streamdir are not
         * wanted in this implementation since they are not maintained. If
         * writing is enabled we'll delete these files if they exist.
         */

        rootdir_node = streamdir_node = NULL;
        dir_loc = NULL;

        /* try to read in the rootdir */
        dir_loc = &ump->fileset_desc->rootdir_icb;
        error = udf_get_node(ump, dir_loc, &rootdir_node, LK_EXCLUSIVE);
        if (error)
                return ENOENT;

        /* apparently it reads in fine */

        /*
         * Try the system stream directory; not very likely in the ones we
         * test, but for completeness.
         */
        dir_loc = &ump->fileset_desc->streamdir_icb;
        if (udf_rw32(dir_loc->len)) {
                printf("udf_read_rootdirs: streamdir defined ");
                error = udf_get_node(ump, dir_loc, &streamdir_node,
                    LK_EXCLUSIVE);
                if (error) {
                        printf("but error in streamdir reading\n");
                } else {
                        printf("but ignored\n");
                        /*
                         * TODO process streamdir `baddies' i.e. files we dont
                         * want if R/W
                         */
                }
        }

        DPRINTF(VOLUMES, ("Rootdir(s) read in fine\n"));

        /* release the vnodes again; they'll be auto-recycled later */
        if (streamdir_node) {
                vput(streamdir_node->vnode);
        }
        if (rootdir_node) {
                vput(rootdir_node->vnode);
        }

        return 0;
}

/* --------------------------------------------------------------------- */

/* To make absolutely sure we are NOT returning zero, add one :) */

long
udf_get_node_id(const struct long_ad *icbptr)
{
        /* ought to be enough since each mountpoint has its own chain */
        return udf_rw32(icbptr->loc.lb_num) + 1;
}


int
udf_compare_icb(const struct long_ad *a, const struct long_ad *b)
{
        if (udf_rw16(a->loc.part_num) < udf_rw16(b->loc.part_num))
                return -1;
        if (udf_rw16(a->loc.part_num) > udf_rw16(b->loc.part_num))
                return 1;

        if (udf_rw32(a->loc.lb_num) < udf_rw32(b->loc.lb_num))
                return -1;
        if (udf_rw32(a->loc.lb_num) > udf_rw32(b->loc.lb_num))
                return 1;

        return 0;
}


static int
udf_compare_rbnodes(void *ctx, const void *a, const void *b)
{
        const struct udf_node *a_node = a;
        const struct udf_node *b_node = b;

        return udf_compare_icb(&a_node->loc, &b_node->loc);
}


static int
udf_compare_rbnode_icb(void *ctx, const void *a, const void *key)
{
        const struct udf_node *a_node = a;
        const struct long_ad * const icb = key;

        return udf_compare_icb(&a_node->loc, icb);
}


static const rb_tree_ops_t udf_node_rbtree_ops = {
        .rbto_compare_nodes = udf_compare_rbnodes,
        .rbto_compare_key = udf_compare_rbnode_icb,
        .rbto_node_offset = offsetof(struct udf_node, rbnode),
        .rbto_context = NULL
};


void
udf_init_nodes_tree(struct udf_mount *ump)
{

        rb_tree_init(&ump->udf_node_tree, &udf_node_rbtree_ops);
}


/* --------------------------------------------------------------------- */

static int
udf_validate_session_start(struct udf_mount *ump)
{
        struct mmc_trackinfo trackinfo;
        struct vrs_desc *vrs;
        uint32_t tracknr, sessionnr, sector, sector_size;
        uint32_t iso9660_vrs, write_track_start;
        uint8_t *buffer, *blank, *pos;
        int blks, max_sectors, vrs_len;
        int error;

        /* disc appendable? */
        if (ump->discinfo.disc_state == MMC_STATE_FULL)
                return EROFS;

        /* already written here? if so, there should be an ISO VDS */
        if (ump->discinfo.last_session_state == MMC_STATE_INCOMPLETE)
                return 0;

        /*
         * Check if the first track of the session is blank and if so, copy or
         * create a dummy ISO descriptor so the disc is valid again.
         */

        tracknr = ump->discinfo.first_track_last_session;
        memset(&trackinfo, 0, sizeof(struct mmc_trackinfo));
        trackinfo.tracknr = tracknr;
        error = udf_update_trackinfo(ump, &trackinfo);
        if (error)
                return error;

        udf_dump_trackinfo(&trackinfo);
        KASSERT(trackinfo.flags & (MMC_TRACKINFO_BLANK | MMC_TRACKINFO_RESERVED));
        KASSERT(trackinfo.sessionnr > 1);

        KASSERT(trackinfo.flags & MMC_TRACKINFO_NWA_VALID);
        write_track_start = trackinfo.next_writable;

        /* we have to copy the ISO VRS from a former session */
        DPRINTF(VOLUMES, ("validate_session_start: "
                        "blank or reserved track, copying VRS\n"));

        /* sessionnr should be the session we're mounting */
        sessionnr = ump->mount_args.sessionnr;

        /* start at the first track */
        tracknr   = ump->discinfo.first_track;
        while (tracknr <= ump->discinfo.num_tracks) {
                trackinfo.tracknr = tracknr;
                error = udf_update_trackinfo(ump, &trackinfo);
                if (error) {
                        DPRINTF(VOLUMES, ("failed to get trackinfo; aborting\n"));
                        return error;
                }
                if (trackinfo.sessionnr == sessionnr)
                        break;
                tracknr++;
        }
        if (trackinfo.sessionnr != sessionnr) {
                DPRINTF(VOLUMES, ("failed to get trackinfo; aborting\n"));
                return ENOENT;
        }

        DPRINTF(VOLUMES, ("found possible former ISO VRS at\n"));
        udf_dump_trackinfo(&trackinfo);

        /*
         * location of iso9660 vrs is defined as first sector AFTER 32kb,
         * minimum ISO `sector size' 2048
         */
        sector_size = ump->discinfo.sector_size;
        iso9660_vrs = ((32*1024 + sector_size - 1) / sector_size)
                 + trackinfo.track_start;

        buffer = malloc(UDF_ISO_VRS_SIZE, M_TEMP, M_WAITOK);
        max_sectors = UDF_ISO_VRS_SIZE / sector_size;
        blks = MAX(1, 2048 / sector_size);

        error = 0;
        for (sector = 0; sector < max_sectors; sector += blks) {
                pos = buffer + sector * sector_size;
                error = udf_read_phys_sectors(ump, UDF_C_DSCR, pos,
                        iso9660_vrs + sector, blks);
                if (error)
                        break;
                /* check this ISO descriptor */
                vrs = (struct vrs_desc *) pos;
                DPRINTF(VOLUMES, ("got VRS id `%4s`\n", vrs->identifier));
                if (strncmp(vrs->identifier, VRS_CD001, 5) == 0)
                        continue;
                if (strncmp(vrs->identifier, VRS_CDW02, 5) == 0)
                        continue;
                if (strncmp(vrs->identifier, VRS_BEA01, 5) == 0)
                        continue;
                if (strncmp(vrs->identifier, VRS_NSR02, 5) == 0)
                        continue;
                if (strncmp(vrs->identifier, VRS_NSR03, 5) == 0)
                        continue;
                if (strncmp(vrs->identifier, VRS_TEA01, 5) == 0)
                        break;
                /* now what? for now, end of sequence */
                break;
        }
        vrs_len = sector + blks;
        if (error) {
                DPRINTF(VOLUMES, ("error reading old ISO VRS\n"));
                DPRINTF(VOLUMES, ("creating minimal ISO VRS\n"));

                memset(buffer, 0, UDF_ISO_VRS_SIZE);

                vrs = (struct vrs_desc *) (buffer);
                vrs->struct_type = 0;
                vrs->version     = 1;
                memcpy(vrs->identifier,VRS_BEA01, 5);

                vrs = (struct vrs_desc *) (buffer + 2048);
                vrs->struct_type = 0;
                vrs->version     = 1;
                if (udf_rw16(ump->logical_vol->tag.descriptor_ver) == 2) {
                        memcpy(vrs->identifier,VRS_NSR02, 5);
                } else {
                        memcpy(vrs->identifier,VRS_NSR03, 5);
                }

                vrs = (struct vrs_desc *) (buffer + 4096);
                vrs->struct_type = 0;
                vrs->version     = 1;
                memcpy(vrs->identifier, VRS_TEA01, 5);

                vrs_len = 3*blks;
        }

        DPRINTF(VOLUMES, ("Got VRS of %d sectors long\n", vrs_len));

        /*
         * location of iso9660 vrs is defined as first sector AFTER 32kb,
         * minimum ISO `sector size' 2048
         */
        sector_size = ump->discinfo.sector_size;
        iso9660_vrs = ((32*1024 + sector_size - 1) / sector_size)
                 + write_track_start;

        /* write out 32 kb */
        blank = malloc(sector_size, M_TEMP, M_WAITOK);
        memset(blank, 0, sector_size);
        error = 0;
        for (sector = write_track_start; sector < iso9660_vrs; sector ++) {
                error = udf_write_phys_sectors(ump, UDF_C_ABSOLUTE,
                        blank, sector, 1);
                if (error)
                        break;
        }
        if (!error) {
                /* write out our ISO VRS */
                KASSERT(sector == iso9660_vrs);
                error = udf_write_phys_sectors(ump, UDF_C_ABSOLUTE, buffer,
                                sector, vrs_len);
                sector += vrs_len;
        }
        if (!error) {
                /* fill upto the first anchor at S+256 */
                for (; sector < write_track_start+256; sector++) {
                        error = udf_write_phys_sectors(ump, UDF_C_ABSOLUTE,
                                blank, sector, 1);
                        if (error)
                                break;
                }
        }
        if (!error) {
                /* write out anchor; write at ABSOLUTE place! */
                error = udf_write_phys_dscr_sync(ump, NULL, UDF_C_ABSOLUTE,
                        (union dscrptr *) ump->anchors[0], sector, sector);
                if (error)
                        printf("writeout of anchor failed!\n");
        }

        free(blank, M_TEMP);
        free(buffer, M_TEMP);

        if (error)
                printf("udf_open_session: error writing iso vrs! : "
                                "leaving disc in compromised state!\n");

        /* synchronise device caches */
        (void) udf_synchronise_caches(ump);

        return error;
}


int
udf_open_logvol(struct udf_mount *ump)
{
        int logvol_integrity;
        int error;

        /* already/still open? */
        logvol_integrity = udf_rw32(ump->logvol_integrity->integrity_type);
        if (logvol_integrity == UDF_INTEGRITY_OPEN)
                return 0;

        /* can we open it ? */
        if (ump->vfs_mountp->mnt_flag & MNT_RDONLY)
                return EROFS;

        /* setup write parameters */
        DPRINTF(VOLUMES, ("Setting up write parameters\n"));
        if ((error = udf_setup_writeparams(ump)) != 0)
                return error;

        /* determine data and metadata tracks (most likely same) */
        error = udf_search_writing_tracks(ump);
        if (error) {
                /* most likely lack of space */
                printf("udf_open_logvol: error searching writing tracks\n");
                return EROFS;
        }

        /* writeout/update lvint on disc or only in memory */
        DPRINTF(VOLUMES, ("Opening logical volume\n"));
        if (ump->lvopen & UDF_OPEN_SESSION) {
                /* TODO optional track reservation opening */
                error = udf_validate_session_start(ump);
                if (error)
                        return error;

                /* determine data and metadata tracks again */
                error = udf_search_writing_tracks(ump);

                if (ump->lvclose & UDF_WRITE_VAT) {
                        /*
                         * we writeout the VAT to get a self-sustained session
                         * for fsck
                         */
                        DPRINTF(VOLUMES, ("lvclose & UDF_WRITE_VAT\n"));

                        /* write out the VAT data and all its descriptors */
                        DPRINTF(VOLUMES, ("writeout vat_node\n"));
                        udf_writeout_vat(ump);

                        /* force everything to be synchronized on the device */
                        (void) udf_synchronise_caches(ump);
                }
        }

        /* mark it open */
        ump->logvol_integrity->integrity_type = udf_rw32(UDF_INTEGRITY_OPEN);

        /* do we need to write it out? */
        if (ump->lvopen & UDF_WRITE_LVINT) {
                error = udf_writeout_lvint(ump, ump->lvopen);
                /* if we couldn't write it mark it closed again */
                if (error) {
                        ump->logvol_integrity->integrity_type =
                                                udf_rw32(UDF_INTEGRITY_CLOSED);
                        return error;
                }
        }

        return 0;
}


int
udf_close_logvol(struct udf_mount *ump, int mntflags)
{
        struct vnode *devvp = ump->devvp;
        struct mmc_op mmc_op;
        uint32_t phys;
        int logvol_integrity;
        int error = 0, error1 = 0, error2 = 0;
        int tracknr;
        int nvats, n, relblk, wrtrack_skew, nok;

        /* already/still closed? */
        logvol_integrity = udf_rw32(ump->logvol_integrity->integrity_type);
        if (logvol_integrity == UDF_INTEGRITY_CLOSED)
                return 0;

        /* writeout/update lvint or write out VAT */
        DPRINTF(VOLUMES, ("udf_close_logvol: closing logical volume\n"));
#ifdef DIAGNOSTIC
        if (ump->lvclose & UDF_CLOSE_SESSION)
                KASSERT(ump->lvclose & UDF_WRITE_VAT);
#endif

        if (ump->lvclose & UDF_WRITE_VAT) {
                DPRINTF(VOLUMES, ("lvclose & UDF_WRITE_VAT\n"));

                /* write out the VAT data and all its descriptors */
                DPRINTF(VOLUMES, ("writeout vat_node\n"));
                udf_writeout_vat(ump);

                /*
                 * For bug-compatibility with Windows, the last VAT sector
                 * must be a multiple of 16/32 from the start of the track.
                 * To allow for scratches, write out at least a 32 pieces.
                 */
                phys = ump->data_track.track_start;
                wrtrack_skew = phys % 32;

                phys = ump->data_track.next_writable;
                relblk = phys % 32;
                nvats = 32 + 32 - (relblk - wrtrack_skew);

#if notyet
                /*
                 * TODO calculate the available space and if the disc is
                 * almost full, write out till end-256-1 with banks, write
                 * AVDP and fill up with VATs, then close session and close
                 * disc.
                 */
                if (ump->lvclose & UDF_FINALISE_DISC) {
                        error = udf_write_phys_dscr_sync(ump, NULL,
                                        UDF_C_FLOAT_DSCR,
                                        (union dscrptr *) ump->anchors[0],
                                        0, 0);
                        if (error)
                                printf("writeout of anchor failed!\n");

                        /* pad space with VAT ICBs */
                        nvats = 256;
                }
#endif

                /* write out a number of VAT nodes */
                nok = 0;
                for (n = 0; n < nvats; n++) {
                        /* will now only write last FE/EFE */
                        ump->vat_node->i_flags |= IN_MODIFIED;
                        error = VOP_FSYNC(ump->vat_node->vnode,
                                        FSCRED, FSYNC_WAIT, 0, 0);
                        if (!error)
                                nok++;
                }
                /* force everything to be synchronized on the device */
                (void) udf_synchronise_caches(ump);

                if (nok < 14) {
                        /* arbitrary; but at least one or two CD frames */
                        printf("writeout of at least 14 VATs failed\n");
                        return error;
                }
        }

        /* NOTE the disc is in a (minimal) valid state now; no erroring out */

        /* finish closing of session */
        if (ump->lvclose & UDF_CLOSE_SESSION) {
                DPRINTF(VOLUMES, ("udf_close_logvol: closing session "
                        "as requested\n"));
                error = udf_validate_session_start(ump);
                if (error)
                        return error;

                (void) udf_synchronise_caches(ump);

                /* close all associated tracks */
                tracknr = ump->discinfo.first_track_last_session;
                error = 0;
                while (tracknr <= ump->discinfo.last_track_last_session) {
                        DPRINTF(VOLUMES, ("\tclosing possible open "
                                "track %d\n", tracknr));
                        memset(&mmc_op, 0, sizeof(mmc_op));
                        mmc_op.operation   = MMC_OP_CLOSETRACK;
                        mmc_op.mmc_profile = ump->discinfo.mmc_profile;
                        mmc_op.tracknr     = tracknr;
                        error = VOP_IOCTL(devvp, MMCOP, &mmc_op,
                                        FKIOCTL, NOCRED);
                        if (error)
                                printf("udf_close_logvol: closing of "
                                        "track %d failed\n", tracknr);
                        tracknr ++;
                }
                if (!error) {
                        DPRINTF(VOLUMES, ("closing session\n"));
                        memset(&mmc_op, 0, sizeof(mmc_op));
                        mmc_op.operation   = MMC_OP_CLOSESESSION;
                        mmc_op.mmc_profile = ump->discinfo.mmc_profile;
                        mmc_op.sessionnr   = ump->discinfo.num_sessions;
                        error = VOP_IOCTL(devvp, MMCOP, &mmc_op,
                                        FKIOCTL, NOCRED);
                        if (error)
                                printf("udf_close_logvol: closing of session"
                                                "failed\n");
                }
                if (!error)
                        ump->lvopen |= UDF_OPEN_SESSION;
                if (error) {
                        printf("udf_close_logvol: leaving disc as it is\n");
                        ump->lvclose &= ~UDF_FINALISE_DISC;
                }
        }

        if (ump->lvclose & UDF_FINALISE_DISC) {
                memset(&mmc_op, 0, sizeof(mmc_op));
                mmc_op.operation   = MMC_OP_FINALISEDISC;
                mmc_op.mmc_profile = ump->discinfo.mmc_profile;
                mmc_op.sessionnr   = ump->discinfo.num_sessions;
                error = VOP_IOCTL(devvp, MMCOP, &mmc_op,
                                FKIOCTL, NOCRED);
                if (error)
                        printf("udf_close_logvol: finalising disc"
                                        "failed\n");
        }

        /* write out partition bitmaps if requested */
        if (ump->lvclose & UDF_WRITE_PART_BITMAPS) {
                /* sync writeout metadata spacetable if existing */
                error1 = udf_write_metadata_partition_spacetable(ump, true);
                if (error1)
                        printf( "udf_close_logvol: writeout of metadata space "
                                "bitmap failed\n");

                /* sync writeout partition spacetables */
                error2 = udf_write_physical_partition_spacetables(ump, true);
                if (error2)
                        printf( "udf_close_logvol: writeout of space tables "
                                "failed\n");

                if (error1 || error2)
                        return (error1 | error2);

                ump->lvclose &= ~UDF_WRITE_PART_BITMAPS;
        }

        /* write out metadata partition nodes if requested */
        if (ump->lvclose & UDF_WRITE_METAPART_NODES) {
                /* sync writeout metadata descriptor node */
                error1 = udf_writeout_node(ump->metadata_node, FSYNC_WAIT);
                if (error1)
                        printf( "udf_close_logvol: writeout of metadata partition "
                                "node failed\n");

                /* duplicate metadata partition descriptor if needed */
                udf_synchronise_metadatamirror_node(ump);

                /* sync writeout metadatamirror descriptor node */
                error2 = udf_writeout_node(ump->metadatamirror_node, FSYNC_WAIT);
                if (error2)
                        printf( "udf_close_logvol: writeout of metadata partition "
                                "mirror node failed\n");

                if (error1 || error2)
                        return (error1 | error2);

                ump->lvclose &= ~UDF_WRITE_METAPART_NODES;
        }

        /* mark it closed */
        ump->logvol_integrity->integrity_type = udf_rw32(UDF_INTEGRITY_CLOSED);

        /* do we need to write out the logical volume integrity? */
        if (ump->lvclose & UDF_WRITE_LVINT)
                error = udf_writeout_lvint(ump, ump->lvopen);
        if (error) {
                /* HELP now what? mark it open again for now */
                ump->logvol_integrity->integrity_type =
                        udf_rw32(UDF_INTEGRITY_OPEN);
                return error;
        }

        (void) udf_synchronise_caches(ump);

        return 0;
}

/* --------------------------------------------------------------------- */

/*
 * Genfs interfacing
 *
 * static const struct genfs_ops udf_genfsops = {
 *      .gop_size = genfs_size,
 *              size of transfers
 *      .gop_alloc = udf_gop_alloc,
 *              allocate len bytes at offset
 *      .gop_write = genfs_gop_write,
 *              putpages interface code
 *      .gop_markupdate = udf_gop_markupdate,
 *              set update/modify flags etc.
 * }
 */

/*
 * Genfs interface. These four functions are the only ones defined though not
 * documented... great....
 */

/*
 * Called for allocating an extent of the file either by VOP_WRITE() or by
 * genfs filling up gaps.
 */
static int
udf_gop_alloc(struct vnode *vp, off_t off,
    off_t len, int flags, kauth_cred_t cred)
{
        struct udf_node *udf_node = VTOI(vp);
        struct udf_mount *ump = udf_node->ump;
        uint64_t lb_start, lb_end;
        uint32_t lb_size, num_lb;
        int udf_c_type, vpart_num, can_fail;
        int error;

        DPRINTF(ALLOC, ("udf_gop_alloc called for offset %"PRIu64" for %"PRIu64" bytes, %s\n",
                off, len, flags? "SYNC":"NONE"));

        /*
         * request the pages of our vnode and see how many pages will need to
         * be allocated and reserve that space
         */
        lb_size  = udf_rw32(udf_node->ump->logical_vol->lb_size);
        lb_start = off / lb_size;
        lb_end   = (off + len + lb_size -1) / lb_size;
        num_lb   = lb_end - lb_start;

        udf_c_type = udf_get_c_type(udf_node);
        vpart_num  = udf_get_record_vpart(ump, udf_c_type);

        /* all requests can fail */
        can_fail   = true;

        /* fid's (directories) can't fail */
        if (udf_c_type == UDF_C_FIDS)
                can_fail   = false;

        /* system files can't fail */
        if (vp->v_vflag & VV_SYSTEM)
                can_fail = false;

        error = udf_reserve_space(ump, udf_node, udf_c_type,
                vpart_num, num_lb, can_fail);

        DPRINTF(ALLOC, ("\tlb_start %"PRIu64", lb_end %"PRIu64", num_lb %d\n",
                lb_start, lb_end, num_lb));

        return error;
}


/*
 * callback from genfs to update our flags
 */
static void
udf_gop_markupdate(struct vnode *vp, int flags)
{
        struct udf_node *udf_node = VTOI(vp);
        u_long mask = 0;

        if ((flags & GOP_UPDATE_ACCESSED) != 0) {
                mask = IN_ACCESS;
        }
        if ((flags & GOP_UPDATE_MODIFIED) != 0) {
                if (vp->v_type == VREG) {
                        mask |= IN_CHANGE | IN_UPDATE;
                } else {
                        mask |= IN_MODIFY;
                }
        }
        if (mask) {
                udf_node->i_flags |= mask;
        }
}


static const struct genfs_ops udf_genfsops = {
        .gop_size = genfs_size,
        .gop_alloc = udf_gop_alloc,
        .gop_write = genfs_gop_write_rwmap,
        .gop_markupdate = udf_gop_markupdate,
        .gop_putrange = genfs_gop_putrange,
};


/* --------------------------------------------------------------------- */

int
udf_write_terminator(struct udf_mount *ump, uint32_t sector)
{
        union dscrptr *dscr;
        int error;

        dscr = malloc(ump->discinfo.sector_size, M_TEMP, M_WAITOK|M_ZERO);
        udf_inittag(ump, &dscr->tag, TAGID_TERM, sector);

        /* CRC length for an anchor is 512 - tag length; defined in Ecma 167 */
        dscr->tag.desc_crc_len = udf_rw16(512-UDF_DESC_TAG_LENGTH);
        (void) udf_validate_tag_and_crc_sums(dscr);

        error = udf_write_phys_dscr_sync(ump, NULL, UDF_C_DSCR,
                        dscr, sector, sector);

        free(dscr, M_TEMP);

        return error;
}


/* --------------------------------------------------------------------- */

/* UDF<->unix converters */

/* --------------------------------------------------------------------- */

static mode_t
udf_perm_to_unix_mode(uint32_t perm)
{
        mode_t mode;

        mode  = ((perm & UDF_FENTRY_PERM_USER_MASK)      );
        mode |= ((perm & UDF_FENTRY_PERM_GRP_MASK  ) >> 2);
        mode |= ((perm & UDF_FENTRY_PERM_OWNER_MASK) >> 4);

        return mode;
}

/* --------------------------------------------------------------------- */

static uint32_t
unix_mode_to_udf_perm(mode_t mode)
{
        uint32_t perm;

        perm  = ((mode & S_IRWXO)     );
        perm |= ((mode & S_IRWXG) << 2);
        perm |= ((mode & S_IRWXU) << 4);
        perm |= ((mode & S_IWOTH) << 3);
        perm |= ((mode & S_IWGRP) << 5);
        perm |= ((mode & S_IWUSR) << 7);

        return perm;
}

/* --------------------------------------------------------------------- */

static uint32_t
udf_icb_to_unix_filetype(uint32_t icbftype)
{
        switch (icbftype) {
        case UDF_ICB_FILETYPE_DIRECTORY :
        case UDF_ICB_FILETYPE_STREAMDIR :
                return S_IFDIR;
        case UDF_ICB_FILETYPE_FIFO :
                return S_IFIFO;
        case UDF_ICB_FILETYPE_CHARDEVICE :
                return S_IFCHR;
        case UDF_ICB_FILETYPE_BLOCKDEVICE :
                return S_IFBLK;
        case UDF_ICB_FILETYPE_RANDOMACCESS :
        case UDF_ICB_FILETYPE_REALTIME :
                return S_IFREG;
        case UDF_ICB_FILETYPE_SYMLINK :
                return S_IFLNK;
        case UDF_ICB_FILETYPE_SOCKET :
                return S_IFSOCK;
        }
        /* no idea what this is */
        return 0;
}

/* --------------------------------------------------------------------- */

void
udf_to_unix_name(char *result, int result_len, char *id, int len,
        struct charspec *chsp)
{
        uint16_t   *raw_name, *unix_name;
        uint16_t   *inchp, ch;
        uint8_t    *outchp;
        const char *osta_id = "OSTA Compressed Unicode";
        int         ucode_chars, nice_uchars, is_osta_typ0, nout;

        raw_name = malloc(2048 * sizeof(uint16_t), M_UDFTEMP, M_WAITOK);
        unix_name = raw_name + 1024;                    /* split space in half */
        assert(sizeof(char) == sizeof(uint8_t));
        outchp = (uint8_t *) result;

        is_osta_typ0  = (chsp->type == 0);
        is_osta_typ0 &= (strcmp((char *) chsp->inf, osta_id) == 0);
        if (is_osta_typ0) {
                /* TODO clean up */
                *raw_name = *unix_name = 0;
                ucode_chars = udf_UncompressUnicode(len, (uint8_t *) id, raw_name);
                ucode_chars = MIN(ucode_chars, UnicodeLength((unicode_t *) raw_name));
                nice_uchars = UDFTransName(unix_name, raw_name, ucode_chars);
                /* output UTF8 */
                for (inchp = unix_name; nice_uchars>0; inchp++, nice_uchars--) {
                        ch = *inchp;
                        nout = wput_utf8(outchp, result_len, ch);
                        outchp += nout; result_len -= nout;
                        if (!ch) break;
                }
                *outchp++ = 0;
        } else {
                /* assume 8bit char length byte latin-1 */
                assert(*id == 8);
                assert(strlen((char *) (id+1)) <= NAME_MAX);
                strncpy((char *) result, (char *) (id+1), strlen((char *) (id+1)));
        }
        free(raw_name, M_UDFTEMP);
}

/* --------------------------------------------------------------------- */

void
unix_to_udf_name(char *result, uint8_t *result_len, char const *name, int name_len,
        struct charspec *chsp)
{
        uint16_t   *raw_name;
        uint16_t   *outchp;
        const char *inchp;
        const char *osta_id = "OSTA Compressed Unicode";
        int         udf_chars, is_osta_typ0, bits;
        size_t      cnt;

        /* allocate temporary unicode-16 buffer */
        raw_name = malloc(1024, M_UDFTEMP, M_WAITOK);

        /* convert utf8 to unicode-16 */
        *raw_name = 0;
        inchp  = name;
        outchp = raw_name;
        bits = 8;
        for (cnt = name_len, udf_chars = 0; cnt;) {
                *outchp = wget_utf8(&inchp, &cnt);
                if (*outchp > 0xff)
                        bits=16;
                outchp++;
                udf_chars++;
        }
        /* null terminate just in case */
        *outchp++ = 0;

        is_osta_typ0  = (chsp->type == 0);
        is_osta_typ0 &= (strcmp((char *) chsp->inf, osta_id) == 0);
        if (is_osta_typ0) {
                udf_chars = udf_CompressUnicode(udf_chars, bits,
                                (unicode_t *) raw_name,
                                (byte *) result);
        } else {
                printf("unix to udf name: no CHSP0 ?\n");
                /* XXX assume 8bit char length byte latin-1 */
                *result++ = 8; udf_chars = 1;
                strncpy(result, name + 1, name_len);
                udf_chars += name_len;
        }
        *result_len = udf_chars;
        free(raw_name, M_UDFTEMP);
}

/* --------------------------------------------------------------------- */

void
udf_timestamp_to_timespec(struct udf_mount *ump,
                          struct timestamp *timestamp,
                          struct timespec  *timespec)
{
        struct clock_ymdhms ymdhms;
        uint32_t usecs, secs, nsecs;
        uint16_t tz;

        /* fill in ymdhms structure from timestamp */
        memset(&ymdhms, 0, sizeof(ymdhms));
        ymdhms.dt_year = udf_rw16(timestamp->year);
        ymdhms.dt_mon  = timestamp->month;
        ymdhms.dt_day  = timestamp->day;
        ymdhms.dt_wday = 0; /* ? */
        ymdhms.dt_hour = timestamp->hour;
        ymdhms.dt_min  = timestamp->minute;
        ymdhms.dt_sec  = timestamp->second;

        secs = clock_ymdhms_to_secs(&ymdhms);
        usecs = timestamp->usec +
                100*timestamp->hund_usec + 10000*timestamp->centisec;
        nsecs = usecs * 1000;

        /*
         * Calculate the time zone.  The timezone is 12 bit signed 2's
         * compliment, so we gotta do some extra magic to handle it right.
         */
        tz  = udf_rw16(timestamp->type_tz);
        tz &= 0x0fff;                   /* only lower 12 bits are significant */
        if (tz & 0x0800)                /* sign extension */
                tz |= 0xf000;

        /* TODO check timezone conversion */
        /* check if we are specified a timezone to convert */
        if (udf_rw16(timestamp->type_tz) & 0x1000) {
                if ((int16_t) tz != -2047)
                        secs -= (int16_t) tz * 60;
        } else {
                secs -= ump->mount_args.gmtoff;
        }

        timespec->tv_sec  = secs;
        timespec->tv_nsec = nsecs;
}


void
udf_timespec_to_timestamp(struct timespec *timespec, struct timestamp *timestamp)
{
        struct clock_ymdhms ymdhms;
        uint32_t husec, usec, csec;

        (void) clock_secs_to_ymdhms(timespec->tv_sec, &ymdhms);

        usec   = timespec->tv_nsec / 1000;
        husec  =  usec / 100;
        usec  -= husec * 100;                           /* only 0-99 in usec  */
        csec   = husec / 100;                           /* only 0-99 in csec  */
        husec -=  csec * 100;                           /* only 0-99 in husec */

        /* set method 1 for CUT/GMT */
        timestamp->type_tz      = udf_rw16((1<<12) + 0);
        timestamp->year         = udf_rw16(ymdhms.dt_year);
        timestamp->month        = ymdhms.dt_mon;
        timestamp->day          = ymdhms.dt_day;
        timestamp->hour         = ymdhms.dt_hour;
        timestamp->minute       = ymdhms.dt_min;
        timestamp->second       = ymdhms.dt_sec;
        timestamp->centisec     = csec;
        timestamp->hund_usec    = husec;
        timestamp->usec         = usec;
}

/* --------------------------------------------------------------------- */

/*
 * Attribute and filetypes converters with get/set pairs
 */

uint32_t
udf_getaccessmode(struct udf_node *udf_node)
{
        struct file_entry     *fe = udf_node->fe;
        struct extfile_entry *efe = udf_node->efe;
        uint32_t udf_perm, icbftype;
        uint32_t mode, ftype;
        uint16_t icbflags;

        UDF_LOCK_NODE(udf_node, 0);
        if (fe) {
                udf_perm = udf_rw32(fe->perm);
                icbftype = fe->icbtag.file_type;
                icbflags = udf_rw16(fe->icbtag.flags);
        } else {
                assert(udf_node->efe);
                udf_perm = udf_rw32(efe->perm);
                icbftype = efe->icbtag.file_type;
                icbflags = udf_rw16(efe->icbtag.flags);
        }

        mode  = udf_perm_to_unix_mode(udf_perm);
        ftype = udf_icb_to_unix_filetype(icbftype);

        /* set suid, sgid, sticky from flags in fe/efe */
        if (icbflags & UDF_ICB_TAG_FLAGS_SETUID)
                mode |= S_ISUID;
        if (icbflags & UDF_ICB_TAG_FLAGS_SETGID)
                mode |= S_ISGID;
        if (icbflags & UDF_ICB_TAG_FLAGS_STICKY)
                mode |= S_ISVTX;

        UDF_UNLOCK_NODE(udf_node, 0);

        return mode | ftype;
}


void
udf_setaccessmode(struct udf_node *udf_node, mode_t mode)
{
        struct file_entry    *fe  = udf_node->fe;
        struct extfile_entry *efe = udf_node->efe;
        uint32_t udf_perm;
        uint16_t icbflags;

        UDF_LOCK_NODE(udf_node, 0);
        udf_perm = unix_mode_to_udf_perm(mode & ALLPERMS);
        if (fe) {
                icbflags = udf_rw16(fe->icbtag.flags);
        } else {
                icbflags = udf_rw16(efe->icbtag.flags);
        }

        icbflags &= ~UDF_ICB_TAG_FLAGS_SETUID;
        icbflags &= ~UDF_ICB_TAG_FLAGS_SETGID;
        icbflags &= ~UDF_ICB_TAG_FLAGS_STICKY;
        if (mode & S_ISUID)
                icbflags |= UDF_ICB_TAG_FLAGS_SETUID;
        if (mode & S_ISGID)
                icbflags |= UDF_ICB_TAG_FLAGS_SETGID;
        if (mode & S_ISVTX)
                icbflags |= UDF_ICB_TAG_FLAGS_STICKY;

        if (fe) {
                fe->perm  = udf_rw32(udf_perm);
                fe->icbtag.flags  = udf_rw16(icbflags);
        } else {
                efe->perm = udf_rw32(udf_perm);
                efe->icbtag.flags = udf_rw16(icbflags);
        }

        UDF_UNLOCK_NODE(udf_node, 0);
}


void
udf_getownership(struct udf_node *udf_node, uid_t *uidp, gid_t *gidp)
{
        struct udf_mount     *ump = udf_node->ump;
        struct file_entry    *fe  = udf_node->fe;
        struct extfile_entry *efe = udf_node->efe;
        uid_t uid;
        gid_t gid;

        UDF_LOCK_NODE(udf_node, 0);
        if (fe) {
                uid = (uid_t)udf_rw32(fe->uid);
                gid = (gid_t)udf_rw32(fe->gid);
        } else {
                assert(udf_node->efe);
                uid = (uid_t)udf_rw32(efe->uid);
                gid = (gid_t)udf_rw32(efe->gid);
        }

        /* do the uid/gid translation game */
        if (uid == (uid_t) -1)
                uid = ump->mount_args.anon_uid;
        if (gid == (gid_t) -1)
                gid = ump->mount_args.anon_gid;

        *uidp = uid;
        *gidp = gid;

        UDF_UNLOCK_NODE(udf_node, 0);
}


void
udf_setownership(struct udf_node *udf_node, uid_t uid, gid_t gid)
{
        struct udf_mount     *ump = udf_node->ump;
        struct file_entry    *fe  = udf_node->fe;
        struct extfile_entry *efe = udf_node->efe;
        uid_t nobody_uid;
        gid_t nobody_gid;

        UDF_LOCK_NODE(udf_node, 0);

        /* do the uid/gid translation game */
        nobody_uid = ump->mount_args.nobody_uid;
        nobody_gid = ump->mount_args.nobody_gid;
        if (uid == nobody_uid)
                uid = (uid_t) -1;
        if (gid == nobody_gid)
                gid = (gid_t) -1;

        if (fe) {
                fe->uid  = udf_rw32((uint32_t) uid);
                fe->gid  = udf_rw32((uint32_t) gid);
        } else {
                efe->uid = udf_rw32((uint32_t) uid);
                efe->gid = udf_rw32((uint32_t) gid);
        }

        UDF_UNLOCK_NODE(udf_node, 0);
}


/* --------------------------------------------------------------------- */


int
udf_dirhash_fill(struct udf_node *dir_node)
{
        struct vnode *dvp = dir_node->vnode;
        struct dirhash *dirh;
        struct file_entry    *fe  = dir_node->fe;
        struct extfile_entry *efe = dir_node->efe;
        struct fileid_desc *fid;
        struct dirent *dirent;
        uint64_t file_size, pre_diroffset, diroffset;
        uint32_t lb_size;
        int error;

        /* make sure we have a dirhash to work on */
        dirh = dir_node->dir_hash;
        KASSERT(dirh);
        KASSERT(dirh->refcnt > 0);

        if (dirh->flags & DIRH_BROKEN)
                return EIO;
        if (dirh->flags & DIRH_COMPLETE)
                return 0;

        /* make sure we have a clean dirhash to add to */
        dirhash_purge_entries(dirh);

        /* get directory filesize */
        if (fe) {
                file_size = udf_rw64(fe->inf_len);
        } else {
                assert(efe);
                file_size = udf_rw64(efe->inf_len);
        }

        /* allocate temporary space for fid */
        lb_size = udf_rw32(dir_node->ump->logical_vol->lb_size);
        fid = malloc(lb_size, M_UDFTEMP, M_WAITOK);

        /* allocate temporary space for dirent */
        dirent = malloc(sizeof(struct dirent), M_UDFTEMP, M_WAITOK);

        error = 0;
        diroffset = 0;
        while (diroffset < file_size) {
                /* transfer a new fid/dirent */
                pre_diroffset = diroffset;
                error = udf_read_fid_stream(dvp, &diroffset, fid, dirent);
                if (error) {
                        /* TODO what to do? continue but not add? */
                        dirh->flags |= DIRH_BROKEN;
                        dirhash_purge_entries(dirh);
                        break;
                }

                if ((fid->file_char & UDF_FILE_CHAR_DEL)) {
                        /* register deleted extent for reuse */
                        dirhash_enter_freed(dirh, pre_diroffset,
                                udf_fidsize(fid));
                } else {
                        /* append to the dirhash */
                        dirhash_enter(dirh, dirent, pre_diroffset,
                                udf_fidsize(fid), 0);
                }
        }
        dirh->flags |= DIRH_COMPLETE;

        free(fid, M_UDFTEMP);
        free(dirent, M_UDFTEMP);

        return error;
}


/* --------------------------------------------------------------------- */

/*
 * Directory read and manipulation functions.
 *
 */

int
udf_lookup_name_in_dir(struct vnode *vp, const char *name, int namelen,
       struct long_ad *icb_loc, int *found)
{
        struct udf_node  *dir_node = VTOI(vp);
        struct dirhash       *dirh;
        struct dirhash_entry *dirh_ep;
        struct fileid_desc *fid;
        struct dirent *dirent, *s_dirent;
        struct charspec osta_charspec;
        uint64_t diroffset;
        uint32_t lb_size;
        int hit, error;

        /* set default return */
        *found = 0;

        /* get our dirhash and make sure its read in */
        dirhash_get(&dir_node->dir_hash);
        error = udf_dirhash_fill(dir_node);
        if (error) {
                dirhash_put(dir_node->dir_hash);
                return error;
        }
        dirh = dir_node->dir_hash;

        /* allocate temporary space for fid */
        lb_size  = udf_rw32(dir_node->ump->logical_vol->lb_size);
        fid      = malloc(lb_size, M_UDFTEMP, M_WAITOK);
        dirent   = malloc(sizeof(struct dirent), M_UDFTEMP, M_WAITOK);
        s_dirent = malloc(sizeof(struct dirent), M_UDFTEMP, M_WAITOK);

        DPRINTF(DIRHASH, ("dirhash_lookup looking for `%*.*s`\n",
                namelen, namelen, name));

        /* convert given unix name to canonical unix name */
        udf_osta_charset(&osta_charspec);
        unix_to_udf_name((char *) fid->data, &fid->l_fi,
                name, namelen, &osta_charspec);
        udf_to_unix_name(s_dirent->d_name, NAME_MAX,
                (char *) fid->data, fid->l_fi,
                &osta_charspec);
        s_dirent->d_namlen = strlen(s_dirent->d_name);

        /* search our dirhash hits */
        memset(icb_loc, 0, sizeof(*icb_loc));
        dirh_ep = NULL;
        for (;;) {
                hit = dirhash_lookup(dirh, s_dirent->d_name, s_dirent->d_namlen, &dirh_ep);
                /* if no hit, abort the search */
                if (!hit)
                        break;

                /* check this hit */
                diroffset = dirh_ep->offset;

                /* transfer a new fid/dirent */
                error = udf_read_fid_stream(vp, &diroffset, fid, dirent);
                if (error)
                        break;

                DPRINTF(DIRHASH, ("dirhash_lookup\tchecking `%*.*s`\n",
                        dirent->d_namlen, dirent->d_namlen, dirent->d_name));

                /* see if its our entry */
                if (strncmp(dirent->d_name, s_dirent->d_name, s_dirent->d_namlen) == 0) {
                        *found = 1;
                        *icb_loc = fid->icb;
                        break;
                }
        }
        free(fid, M_UDFTEMP);
        free(dirent, M_UDFTEMP);
        free(s_dirent, M_UDFTEMP);

        dirhash_put(dir_node->dir_hash);

        return error;
}

/* --------------------------------------------------------------------- */

static int
udf_create_new_fe(struct udf_mount *ump, struct file_entry *fe, int file_type,
        struct long_ad *node_icb, struct long_ad *parent_icb,
        uint64_t parent_unique_id)
{
        struct timespec now;
        struct icb_tag *icb;
        struct filetimes_extattr_entry *ft_extattr;
        uint64_t unique_id;
        uint32_t fidsize, lb_num;
        uint8_t *bpos;
        int crclen, attrlen;

        lb_num = udf_rw32(node_icb->loc.lb_num);
        udf_inittag(ump, &fe->tag, TAGID_FENTRY, lb_num);
        icb = &fe->icbtag;

        /*
         * Always use strategy type 4 unless on WORM which we don't support
         * (yet). Fill in defaults and set for internal allocation of data.
         */
        icb->strat_type      = udf_rw16(4);
        icb->max_num_entries = udf_rw16(1);
        icb->file_type       = file_type;       /* 8 bit */
        icb->flags           = udf_rw16(UDF_ICB_INTERN_ALLOC);

        fe->perm     = udf_rw32(0x7fff);        /* all is allowed   */
        fe->link_cnt = udf_rw16(0);             /* explicit setting */

        fe->ckpoint  = udf_rw32(1);             /* user supplied file version */

        vfs_timestamp(&now);
        udf_timespec_to_timestamp(&now, &fe->atime);
        udf_timespec_to_timestamp(&now, &fe->attrtime);
        udf_timespec_to_timestamp(&now, &fe->mtime);

        udf_set_regid(&fe->imp_id, IMPL_NAME);
        udf_add_impl_regid(ump, &fe->imp_id);

        unique_id = udf_advance_uniqueid(ump);
        fe->unique_id = udf_rw64(unique_id);
        fe->l_ea = udf_rw32(0);

        /* create extended attribute to record our creation time */
        attrlen = UDF_FILETIMES_ATTR_SIZE(1);
        ft_extattr = malloc(attrlen, M_UDFTEMP, M_WAITOK);
        memset(ft_extattr, 0, attrlen);
        ft_extattr->hdr.type = udf_rw32(UDF_FILETIMES_ATTR_NO);
        ft_extattr->hdr.subtype = 1;    /* [4/48.10.5] */
        ft_extattr->hdr.a_l = udf_rw32(UDF_FILETIMES_ATTR_SIZE(1));
        ft_extattr->d_l     = udf_rw32(UDF_TIMESTAMP_SIZE); /* one item */
        ft_extattr->existence = UDF_FILETIMES_FILE_CREATION;
        udf_timespec_to_timestamp(&now, &ft_extattr->times[0]);

        udf_extattr_insert_internal(ump, (union dscrptr *) fe,
                (struct extattr_entry *) ft_extattr);
        free(ft_extattr, M_UDFTEMP);

        /* if its a directory, create '..' */
        bpos = (uint8_t *) fe->data + udf_rw32(fe->l_ea);
        fidsize = 0;
        if (file_type == UDF_ICB_FILETYPE_DIRECTORY) {
                fidsize = udf_create_parentfid(ump,
                        (struct fileid_desc *) bpos, parent_icb,
                        parent_unique_id);
        }

        /* record fidlength information */
        fe->inf_len = udf_rw64(fidsize);
        fe->l_ad    = udf_rw32(fidsize);
        fe->logblks_rec = udf_rw64(0);          /* intern */

        crclen  = sizeof(struct file_entry) - 1 - UDF_DESC_TAG_LENGTH;
        crclen += udf_rw32(fe->l_ea) + fidsize;
        fe->tag.desc_crc_len = udf_rw16(crclen);

        (void) udf_validate_tag_and_crc_sums((union dscrptr *) fe);

        return fidsize;
}

/* --------------------------------------------------------------------- */

static int
udf_create_new_efe(struct udf_mount *ump, struct extfile_entry *efe,
        int file_type, struct long_ad *node_icb, struct long_ad *parent_icb,
        uint64_t parent_unique_id)
{
        struct timespec now;
        struct icb_tag *icb;
        uint64_t unique_id;
        uint32_t fidsize, lb_num;
        uint8_t *bpos;
        int crclen;

        lb_num = udf_rw32(node_icb->loc.lb_num);
        udf_inittag(ump, &efe->tag, TAGID_EXTFENTRY, lb_num);
        icb = &efe->icbtag;

        /*
         * Always use strategy type 4 unless on WORM which we don't support
         * (yet). Fill in defaults and set for internal allocation of data.
         */
        icb->strat_type      = udf_rw16(4);
        icb->max_num_entries = udf_rw16(1);
        icb->file_type       = file_type;       /* 8 bit */
        icb->flags           = udf_rw16(UDF_ICB_INTERN_ALLOC);

        efe->perm     = udf_rw32(0x7fff);       /* all is allowed   */
        efe->link_cnt = udf_rw16(0);            /* explicit setting */

        efe->ckpoint  = udf_rw32(1);            /* user supplied file version */

        vfs_timestamp(&now);
        udf_timespec_to_timestamp(&now, &efe->ctime);
        udf_timespec_to_timestamp(&now, &efe->atime);
        udf_timespec_to_timestamp(&now, &efe->attrtime);
        udf_timespec_to_timestamp(&now, &efe->mtime);

        udf_set_regid(&efe->imp_id, IMPL_NAME);
        udf_add_impl_regid(ump, &efe->imp_id);

        unique_id = udf_advance_uniqueid(ump);
        efe->unique_id = udf_rw64(unique_id);
        efe->l_ea = udf_rw32(0);

        /* if its a directory, create '..' */
        bpos = (uint8_t *) efe->data + udf_rw32(efe->l_ea);
        fidsize = 0;
        if (file_type == UDF_ICB_FILETYPE_DIRECTORY) {
                fidsize = udf_create_parentfid(ump,
                        (struct fileid_desc *) bpos, parent_icb,
                        parent_unique_id);
        }

        /* record fidlength information */
        efe->obj_size = udf_rw64(fidsize);
        efe->inf_len  = udf_rw64(fidsize);
        efe->l_ad     = udf_rw32(fidsize);
        efe->logblks_rec = udf_rw64(0);         /* intern */

        crclen  = sizeof(struct extfile_entry) - 1 - UDF_DESC_TAG_LENGTH;
        crclen += udf_rw32(efe->l_ea) + fidsize;
        efe->tag.desc_crc_len = udf_rw16(crclen);

        (void) udf_validate_tag_and_crc_sums((union dscrptr *) efe);

        return fidsize;
}

/* --------------------------------------------------------------------- */

int
udf_dir_detach(struct udf_mount *ump, struct udf_node *dir_node,
        struct udf_node *udf_node, struct componentname *cnp)
{
        struct vnode *dvp = dir_node->vnode;
        struct dirhash       *dirh;
        struct dirhash_entry *dirh_ep;
        struct file_entry    *fe  = dir_node->fe;
        struct fileid_desc *fid;
        struct dirent *dirent, *s_dirent;
        struct charspec osta_charspec;
        uint64_t diroffset;
        uint32_t lb_size, fidsize;
        int found, error;
        int hit, refcnt;

        /* get our dirhash and make sure its read in */
        dirhash_get(&dir_node->dir_hash);
        error = udf_dirhash_fill(dir_node);
        if (error) {
                dirhash_put(dir_node->dir_hash);
                return error;
        }
        dirh = dir_node->dir_hash;

        /* get directory filesize */
        if (!fe) {
                assert(dir_node->efe);
        }

        /* allocate temporary space for fid and dirents */
        lb_size  = udf_rw32(dir_node->ump->logical_vol->lb_size);
        fid      = malloc(lb_size, M_UDFTEMP, M_WAITOK);
        dirent   = malloc(sizeof(struct dirent), M_UDFTEMP, M_WAITOK);
        s_dirent = malloc(sizeof(struct dirent), M_UDFTEMP, M_WAITOK);

        /* convert given unix name to canonical unix name */
        udf_osta_charset(&osta_charspec);
        unix_to_udf_name((char *) fid->data, &fid->l_fi,
                cnp->cn_nameptr, cnp->cn_namelen, &osta_charspec);
        udf_to_unix_name(s_dirent->d_name, NAME_MAX,
                (char *) fid->data, fid->l_fi,
                &osta_charspec);
        s_dirent->d_namlen = strlen(s_dirent->d_name);

        /* search our dirhash hits */
        found = 0;
        dirh_ep = NULL;
        for (;;) {
                hit = dirhash_lookup(dirh, s_dirent->d_name, s_dirent->d_namlen, &dirh_ep);
                /* if no hit, abort the search */
                if (!hit)
                        break;

                /* check this hit */
                diroffset = dirh_ep->offset;

                /* transfer a new fid/dirent */
                error = udf_read_fid_stream(dvp, &diroffset, fid, dirent);
                if (error)
                        break;

                /* see if its our entry */
                KASSERT(dirent->d_namlen == s_dirent->d_namlen);
                if (strncmp(dirent->d_name, s_dirent->d_name, s_dirent->d_namlen) == 0) {
                        found = 1;
                        break;
                }
        }

        if (!found)
                error = ENOENT;
        if (error)
                goto error_out;

        /* mark deleted */
        fid->file_char |= UDF_FILE_CHAR_DEL;
#ifdef UDF_COMPLETE_DELETE
        memset(&fid->icb, 0, sizeof(fid->icb));
#endif
        (void) udf_validate_tag_and_crc_sums((union dscrptr *) fid);

        /* get size of fid and compensate for the read_fid_stream advance */
        fidsize = udf_fidsize(fid);
        diroffset -= fidsize;

        /* write out */
        error = vn_rdwr(UIO_WRITE, dir_node->vnode,
                        fid, fidsize, diroffset,
                        UIO_SYSSPACE, IO_ALTSEMANTICS | IO_NODELOCKED,
                        FSCRED, NULL, NULL);
        if (error)
                goto error_out;

        /* get reference count of attached node */
        if (udf_node->fe) {
                refcnt = udf_rw16(udf_node->fe->link_cnt);
        } else {
                KASSERT(udf_node->efe);
                refcnt = udf_rw16(udf_node->efe->link_cnt);
        }
#ifdef UDF_COMPLETE_DELETE
        /* subtract reference counter in attached node */
        refcnt -= 1;
        if (udf_node->fe) {
                udf_node->fe->link_cnt = udf_rw16(refcnt);
        } else {
                udf_node->efe->link_cnt = udf_rw16(refcnt);
        }

        /* prevent writeout when refcnt == 0 */
        if (refcnt == 0)
                udf_node->i_flags |= IN_DELETED;

        if (fid->file_char & UDF_FILE_CHAR_DIR) {
                int drefcnt;

                /* subtract reference counter in directory node */
                /* note subtract 2 (?) for its was also backreferenced */
                if (dir_node->fe) {
                        drefcnt  = udf_rw16(dir_node->fe->link_cnt);
                        drefcnt -= 1;
                        dir_node->fe->link_cnt = udf_rw16(drefcnt);
                } else {
                        KASSERT(dir_node->efe);
                        drefcnt  = udf_rw16(dir_node->efe->link_cnt);
                        drefcnt -= 1;
                        dir_node->efe->link_cnt = udf_rw16(drefcnt);
                }
        }

        udf_node->i_flags |= IN_MODIFIED;
        dir_node->i_flags |= IN_MODIFIED;
#endif
        /* if it is/was a hardlink adjust the file count */
        if (refcnt > 0)
                udf_adjust_filecount(udf_node, -1);

        /* remove from the dirhash */
        dirhash_remove(dirh, dirent, diroffset,
                udf_fidsize(fid));

error_out:
        free(fid, M_UDFTEMP);
        free(dirent, M_UDFTEMP);
        free(s_dirent, M_UDFTEMP);

        dirhash_put(dir_node->dir_hash);

        return error;
}

/* --------------------------------------------------------------------- */

int
udf_dir_update_rootentry(struct udf_mount *ump, struct udf_node *dir_node,
        struct udf_node *new_parent_node)
{
        struct vnode *dvp = dir_node->vnode;
        struct dirhash       *dirh;
        struct dirhash_entry *dirh_ep;
        struct file_entry    *fe;
        struct extfile_entry *efe;
        struct fileid_desc *fid;
        struct dirent *dirent;
        uint64_t diroffset;
        uint64_t new_parent_unique_id;
        uint32_t lb_size, fidsize;
        int found, error;
        char const *name  = "..";
        int namelen = 2;
        int hit;

        /* get our dirhash and make sure its read in */
        dirhash_get(&dir_node->dir_hash);
        error = udf_dirhash_fill(dir_node);
        if (error) {
                dirhash_put(dir_node->dir_hash);
                return error;
        }
        dirh = dir_node->dir_hash;

        /* get new parent's unique ID */
        fe  = new_parent_node->fe;
        efe = new_parent_node->efe;
        if (fe) {
                new_parent_unique_id = udf_rw64(fe->unique_id);
        } else {
                assert(efe);
                new_parent_unique_id = udf_rw64(efe->unique_id);
        }

        /* get directory filesize */
        fe  = dir_node->fe;
        efe = dir_node->efe;
        if (!fe) {
                assert(efe);
        }

        /* allocate temporary space for fid */
        lb_size = udf_rw32(dir_node->ump->logical_vol->lb_size);
        fid     = malloc(lb_size, M_UDFTEMP, M_WAITOK);
        dirent  = malloc(sizeof(struct dirent), M_UDFTEMP, M_WAITOK);

        /*
         * NOTE the standard does not dictate the FID entry '..' should be
         * first, though in practice it will most likely be.
         */

        /* search our dirhash hits */
        found = 0;
        dirh_ep = NULL;
        for (;;) {
                hit = dirhash_lookup(dirh, name, namelen, &dirh_ep);
                /* if no hit, abort the search */
                if (!hit)
                        break;

                /* check this hit */
                diroffset = dirh_ep->offset;

                /* transfer a new fid/dirent */
                error = udf_read_fid_stream(dvp, &diroffset, fid, dirent);
                if (error)
                        break;

                /* see if its our entry */
                KASSERT(dirent->d_namlen == namelen);
                if (strncmp(dirent->d_name, name, namelen) == 0) {
                        found = 1;
                        break;
                }
        }

        if (!found)
                error = ENOENT;
        if (error)
                goto error_out;

        /* update our ICB to the new parent, hit of lower 32 bits of uniqueid */
        fid->icb = new_parent_node->write_loc;
        fid->icb.longad_uniqueid = udf_rw32(new_parent_unique_id);

        (void) udf_validate_tag_and_crc_sums((union dscrptr *) fid);

        /* get size of fid and compensate for the read_fid_stream advance */
        fidsize = udf_fidsize(fid);
        diroffset -= fidsize;

        /* write out */
        error = vn_rdwr(UIO_WRITE, dir_node->vnode,
                        fid, fidsize, diroffset,
                        UIO_SYSSPACE, IO_ALTSEMANTICS | IO_NODELOCKED,
                        FSCRED, NULL, NULL);

        /* nothing to be done in the dirhash */

error_out:
        free(fid, M_UDFTEMP);
        free(dirent, M_UDFTEMP);

        dirhash_put(dir_node->dir_hash);

        return error;
}

/* --------------------------------------------------------------------- */

/*
 * We are not allowed to split the fid tag itself over an logical block so
 * check the space remaining in the logical block.
 *
 * We try to select the smallest candidate for recycling or when none is
 * found, append a new one at the end of the directory.
 */

int
udf_dir_attach(struct udf_mount *ump, struct udf_node *dir_node,
        struct udf_node *udf_node, struct vattr *vap, struct componentname *cnp)
{
        struct vnode *dvp = dir_node->vnode;
        struct dirhash       *dirh;
        struct dirhash_entry *dirh_ep;
        struct fileid_desc   *fid;
        struct icb_tag       *icbtag;
        struct charspec osta_charspec;
        struct dirent   dirent;
        uint64_t unique_id, dir_size;
        uint64_t fid_pos, end_fid_pos, chosen_fid_pos;
        uint32_t chosen_size, chosen_size_diff;
        int lb_size, lb_rest, fidsize, this_fidsize, size_diff;
        int file_char, refcnt, icbflags, addr_type, hit, error;

        /* get our dirhash and make sure its read in */
        dirhash_get(&dir_node->dir_hash);
        error = udf_dirhash_fill(dir_node);
        if (error) {
                dirhash_put(dir_node->dir_hash);
                return error;
        }
        dirh = dir_node->dir_hash;

        /* get info */
        lb_size = udf_rw32(ump->logical_vol->lb_size);
        udf_osta_charset(&osta_charspec);

        if (dir_node->fe) {
                dir_size = udf_rw64(dir_node->fe->inf_len);
                icbtag   = &dir_node->fe->icbtag;
        } else {
                dir_size = udf_rw64(dir_node->efe->inf_len);
                icbtag   = &dir_node->efe->icbtag;
        }

        icbflags   = udf_rw16(icbtag->flags);
        addr_type  = icbflags & UDF_ICB_TAG_FLAGS_ALLOC_MASK;

        if (udf_node->fe) {
                unique_id = udf_rw64(udf_node->fe->unique_id);
                refcnt    = udf_rw16(udf_node->fe->link_cnt);
        } else {
                unique_id = udf_rw64(udf_node->efe->unique_id);
                refcnt    = udf_rw16(udf_node->efe->link_cnt);
        }

        if (refcnt > 0) {
                unique_id = udf_advance_uniqueid(ump);
                udf_adjust_filecount(udf_node, 1);
        }

        /* determine file characteristics */
        file_char = 0;  /* visible non deleted file and not stream metadata */
        if (vap->va_type == VDIR)
                file_char = UDF_FILE_CHAR_DIR;

        /* malloc scrap buffer */
        fid = malloc(lb_size, M_TEMP, M_WAITOK|M_ZERO);

        /* calculate _minimum_ fid size */
        unix_to_udf_name((char *) fid->data, &fid->l_fi,
                cnp->cn_nameptr, cnp->cn_namelen, &osta_charspec);
        fidsize = UDF_FID_SIZE + fid->l_fi;
        fidsize = (fidsize + 3) & ~3;           /* multiple of 4 */

        /* find position that will fit the FID */
        chosen_fid_pos   = dir_size;
        chosen_size      = 0;
        chosen_size_diff = UINT_MAX;

        /* shut up gcc */
        dirent.d_namlen = 0;

        /* search our dirhash hits */
        error = 0;
        dirh_ep = NULL;
        for (;;) {
                hit = dirhash_lookup_freed(dirh, fidsize, &dirh_ep);
                /* if no hit, abort the search */
                if (!hit)
                        break;

                /* check this hit for size */
                this_fidsize = dirh_ep->entry_size;

                /* check this hit */
                fid_pos     = dirh_ep->offset;
                end_fid_pos = fid_pos + this_fidsize;
                size_diff   = this_fidsize - fidsize;
                lb_rest = lb_size - (end_fid_pos % lb_size);

#ifndef UDF_COMPLETE_DELETE
                /* transfer a new fid/dirent */
                error = udf_read_fid_stream(vp, &fid_pos, fid, dirent);
                if (error)
                        goto error_out;

                /* only reuse entries that are wiped */
                /* check if the len + loc are marked zero */
                if (udf_rw32(fid->icb.len) != 0)
                        continue;
                if (udf_rw32(fid->icb.loc.lb_num) != 0)
                        continue;
                if (udf_rw16(fid->icb.loc.part_num) != 0)
                        continue;
#endif  /* UDF_COMPLETE_DELETE */

                /* select if not splitting the tag and its smaller */
                if ((size_diff >= 0)  &&
                        (size_diff < chosen_size_diff) &&
                        (lb_rest >= sizeof(struct desc_tag)))
                {
                        /* UDF 2.3.4.2+3 specifies rules for iu size */
                        if ((size_diff == 0) || (size_diff >= 32)) {
                                chosen_fid_pos   = fid_pos;
                                chosen_size      = this_fidsize;
                                chosen_size_diff = size_diff;
                        }
                }
        }


        /* extend directory if no other candidate found */
        if (chosen_size == 0) {
                chosen_fid_pos   = dir_size;
                chosen_size      = fidsize;
                chosen_size_diff = 0;

                /* special case UDF 2.00+ 2.3.4.4, no splitting up fid tag */
                if (addr_type == UDF_ICB_INTERN_ALLOC) {
                        /* pre-grow directory to see if we're to switch */
                        udf_grow_node(dir_node, dir_size + chosen_size);

                        icbflags   = udf_rw16(icbtag->flags);
                        addr_type  = icbflags & UDF_ICB_TAG_FLAGS_ALLOC_MASK;
                }

                /* make sure the next fid desc_tag won't be split */
                if (addr_type != UDF_ICB_INTERN_ALLOC) {
                        end_fid_pos = chosen_fid_pos + chosen_size;
                        lb_rest = lb_size - (end_fid_pos % lb_size);

                        /* pad with implementation use regid if needed */
                        if (lb_rest < sizeof(struct desc_tag))
                                chosen_size += 32;
                }
        }
        chosen_size_diff = chosen_size - fidsize;

        /* populate the FID */
        memset(fid, 0, lb_size);
        udf_inittag(ump, &fid->tag, TAGID_FID, 0);
        fid->file_version_num    = udf_rw16(1); /* UDF 2.3.4.1 */
        fid->file_char           = file_char;
        fid->icb                 = udf_node->loc;
        fid->icb.longad_uniqueid = udf_rw32((uint32_t) unique_id);
        fid->l_iu                = udf_rw16(0);

        if (chosen_size > fidsize) {
                /* insert implementation-use regid to space it correctly */
                fid->l_iu = udf_rw16(chosen_size_diff);

                /* set implementation use */
                udf_set_regid((struct regid *) fid->data, IMPL_NAME);
                udf_add_impl_regid(ump, (struct regid *) fid->data);
        }

        /* fill in name */
        unix_to_udf_name((char *) fid->data + udf_rw16(fid->l_iu),
                &fid->l_fi, cnp->cn_nameptr, cnp->cn_namelen, &osta_charspec);

        fid->tag.desc_crc_len = udf_rw16(chosen_size - UDF_DESC_TAG_LENGTH);
        (void) udf_validate_tag_and_crc_sums((union dscrptr *) fid);

        /* writeout FID/update parent directory */
        error = vn_rdwr(UIO_WRITE, dvp,
                        fid, chosen_size, chosen_fid_pos,
                        UIO_SYSSPACE, IO_ALTSEMANTICS | IO_NODELOCKED,
                        FSCRED, NULL, NULL);

        if (error)
                goto error_out;

        /* add reference counter in attached node */
        if (udf_node->fe) {
                refcnt = udf_rw16(udf_node->fe->link_cnt);
                udf_node->fe->link_cnt = udf_rw16(refcnt+1);
        } else {
                KASSERT(udf_node->efe);
                refcnt = udf_rw16(udf_node->efe->link_cnt);
                udf_node->efe->link_cnt = udf_rw16(refcnt+1);
        }

        /* mark not deleted if it was... just in case, but do warn */
        if (udf_node->i_flags & IN_DELETED) {
                printf("udf: warning, marking a file undeleted\n");
                udf_node->i_flags &= ~IN_DELETED;
        }

        if (file_char & UDF_FILE_CHAR_DIR) {
                /* add reference counter in directory node for '..' */
                if (dir_node->fe) {
                        refcnt = udf_rw16(dir_node->fe->link_cnt);
                        refcnt++;
                        dir_node->fe->link_cnt = udf_rw16(refcnt);
                } else {
                        KASSERT(dir_node->efe);
                        refcnt = udf_rw16(dir_node->efe->link_cnt);
                        refcnt++;
                        dir_node->efe->link_cnt = udf_rw16(refcnt);
                }
        }

        /* append to the dirhash */
        /* NOTE do not use dirent anymore or it won't match later! */
        udf_to_unix_name(dirent.d_name, NAME_MAX,
                (char *) fid->data + udf_rw16(fid->l_iu), fid->l_fi, &osta_charspec);
        dirent.d_namlen = strlen(dirent.d_name);
        dirhash_enter(dirh, &dirent, chosen_fid_pos,
                udf_fidsize(fid), 1);

        /* note updates */
        udf_node->i_flags |= IN_CHANGE | IN_MODIFY; /* | IN_CREATE? */
        /* VN_KNOTE(udf_node,  ...) */
        udf_update(udf_node->vnode, NULL, NULL, NULL, 0);

error_out:
        free(fid, M_TEMP);

        dirhash_put(dir_node->dir_hash);

        return error;
}

/* --------------------------------------------------------------------- */

/*
 * Each node can have an attached streamdir node though not recursively. These
 * are otherwise known as named substreams/named extended attributes that have
 * no size limitations.
 *
 * `Normal' extended attributes are indicated with a number and are recorded
 * in either the fe/efe descriptor itself for small descriptors or recorded in
 * the attached extended attribute file. Since these spaces can get
 * fragmented, care ought to be taken.
 *
 * Since the size of the space reserved for allocation descriptors is limited,
 * there is a mechanim provided for extending this space; this is done by a
 * special extent to allow shrinking of the allocations without breaking the
 * linkage to the allocation extent descriptor.
 */

int
udf_loadvnode(struct mount *mp, struct vnode *vp,
     const void *key, size_t key_len, const void **new_key)
{
        union dscrptr   *dscr;
        struct udf_mount *ump;
        struct udf_node *udf_node;
        struct long_ad node_icb_loc, icb_loc, next_icb_loc, last_fe_icb_loc;
        uint64_t file_size;
        uint32_t lb_size, sector, dummy;
        int udf_file_type, dscr_type, strat, strat4096, needs_indirect;
        int slot, eof, error;
        int num_indir_followed = 0;

        DPRINTF(NODE, ("udf_loadvnode called\n"));
        udf_node = NULL;
        ump = VFSTOUDF(mp);

        KASSERT(key_len == sizeof(node_icb_loc.loc));
        memset(&node_icb_loc, 0, sizeof(node_icb_loc));
        node_icb_loc.len = ump->logical_vol->lb_size;
        memcpy(&node_icb_loc.loc, key, key_len);

        /* garbage check: translate udf_node_icb_loc to sectornr */
        error = udf_translate_vtop(ump, &node_icb_loc, &sector, &dummy);
        if (error) {
                DPRINTF(NODE, ("\tcan't translate icb address!\n"));
                /* no use, this will fail anyway */
                return EINVAL;
        }

        /* build udf_node (do initialise!) */
        udf_node = pool_get(&udf_node_pool, PR_WAITOK);
        memset(udf_node, 0, sizeof(struct udf_node));

        vp->v_tag = VT_UDF;
        vp->v_op = udf_vnodeop_p;
        vp->v_data = udf_node;

        /* initialise crosslinks, note location of fe/efe for hashing */
        udf_node->ump    =  ump;
        udf_node->vnode  =  vp;
        udf_node->loc    =  node_icb_loc;
        udf_node->lockf  =  0;
        mutex_init(&udf_node->node_mutex, MUTEX_DEFAULT, IPL_NONE);
        cv_init(&udf_node->node_lock, "udf_nlk");
        genfs_node_init(vp, &udf_genfsops);     /* initialise genfs */
        udf_node->outstanding_bufs = 0;
        udf_node->outstanding_nodedscr = 0;
        udf_node->uncommitted_lbs = 0;

        /* check if we're fetching the root */
        if (ump->fileset_desc)
                if (memcmp(&udf_node->loc, &ump->fileset_desc->rootdir_icb,
                    sizeof(struct long_ad)) == 0)
                        vp->v_vflag |= VV_ROOT;

        icb_loc = node_icb_loc;
        needs_indirect = 0;
        strat4096 = 0;
        udf_file_type = UDF_ICB_FILETYPE_UNKNOWN;
        file_size = 0;
        lb_size = udf_rw32(ump->logical_vol->lb_size);

        DPRINTF(NODE, ("\tstart reading descriptors\n"));
        do {
                /* try to read in fe/efe */
                error = udf_read_logvol_dscr(ump, &icb_loc, &dscr);

                /* blank sector marks end of sequence, check this */
                if ((dscr == NULL) &&  (!strat4096))
                        error = ENOENT;

                /* break if read error or blank sector */
                if (error || (dscr == NULL))
                        break;

                /* process descriptor based on the descriptor type */
                dscr_type = udf_rw16(dscr->tag.id);
                DPRINTF(NODE, ("\tread descriptor %d\n", dscr_type));

                /* if dealing with an indirect entry, follow the link */
                if (dscr_type == TAGID_INDIRECTENTRY) {
                        needs_indirect = 0;
                        next_icb_loc = dscr->inde.indirect_icb;
                        udf_free_logvol_dscr(ump, &icb_loc, dscr);
                        icb_loc = next_icb_loc;
                        if (++num_indir_followed > UDF_MAX_INDIRS_FOLLOW) {
                                error = EMLINK;
                                break;
                        }
                        continue;
                }

                /* only file entries and extended file entries allowed here */
                if ((dscr_type != TAGID_FENTRY) &&
                    (dscr_type != TAGID_EXTFENTRY)) {
                        udf_free_logvol_dscr(ump, &icb_loc, dscr);
                        error = ENOENT;
                        break;
                }

                KASSERT(udf_tagsize(dscr, lb_size) == lb_size);

                /* choose this one */
                last_fe_icb_loc = icb_loc;

                /* record and process/update (ext)fentry */
                if (dscr_type == TAGID_FENTRY) {
                        if (udf_node->fe)
                                udf_free_logvol_dscr(ump, &last_fe_icb_loc,
                                        udf_node->fe);
                        udf_node->fe  = &dscr->fe;
                        strat = udf_rw16(udf_node->fe->icbtag.strat_type);
                        udf_file_type = udf_node->fe->icbtag.file_type;
                        file_size = udf_rw64(udf_node->fe->inf_len);
                } else {
                        if (udf_node->efe)
                                udf_free_logvol_dscr(ump, &last_fe_icb_loc,
                                        udf_node->efe);
                        udf_node->efe = &dscr->efe;
                        strat = udf_rw16(udf_node->efe->icbtag.strat_type);
                        udf_file_type = udf_node->efe->icbtag.file_type;
                        file_size = udf_rw64(udf_node->efe->inf_len);
                }

                /* check recording strategy (structure) */

                /*
                 * Strategy 4096 is a daisy linked chain terminating with an
                 * unrecorded sector or a TERM descriptor. The next
                 * descriptor is to be found in the sector that follows the
                 * current sector.
                 */
                if (strat == 4096) {
                        strat4096 = 1;
                        needs_indirect = 1;

                        icb_loc.loc.lb_num = udf_rw32(icb_loc.loc.lb_num) + 1;
                }

                /*
                 * Strategy 4 is the normal strategy and terminates, but if
                 * we're in strategy 4096, we can't have strategy 4 mixed in
                 */

                if (strat == 4) {
                        if (strat4096) {
                                error = EINVAL;
                                break;
                        }
                        break;          /* done */
                }
        } while (!error);

        /* first round of cleanup code */
        if (error) {
                DPRINTF(NODE, ("\tnode fe/efe failed!\n"));
                /* recycle udf_node */
                udf_dispose_node(udf_node);

                return EINVAL;          /* error code ok? */
        }
        DPRINTF(NODE, ("\tnode fe/efe read in fine\n"));

        /* assert no references to dscr anymore beyond this point */
        assert((udf_node->fe) || (udf_node->efe));
        dscr = NULL;

        /*
         * Remember where to record an updated version of the descriptor. If
         * there is a sequence of indirect entries, icb_loc will have been
         * updated. It's the write discipline to allocate new space and to make
         * sure the chain is maintained.
         *
         * `needs_indirect' flags if the next location is to be filled with
         * an indirect entry.
         */
        udf_node->write_loc = icb_loc;
        udf_node->needs_indirect = needs_indirect;

        /*
         * Go through all allocations extents of this descriptor and when
         * encountering a redirect read in the allocation extension. These are
         * daisy-chained.
         */
        UDF_LOCK_NODE(udf_node, 0);
        udf_node->num_extensions = 0;

        error   = 0;
        slot    = 0;
        for (;;) {
                udf_get_adslot(udf_node, slot, &icb_loc, &eof);
                DPRINTF(ADWLK, ("slot %d, eof = %d, flags = %d, len = %d, "
                        "lb_num = %d, part = %d\n", slot, eof,
                        UDF_EXT_FLAGS(udf_rw32(icb_loc.len)),
                        UDF_EXT_LEN(udf_rw32(icb_loc.len)),
                        udf_rw32(icb_loc.loc.lb_num),
                        udf_rw16(icb_loc.loc.part_num)));
                if (eof)
                        break;
                slot++;

                if (UDF_EXT_FLAGS(udf_rw32(icb_loc.len)) != UDF_EXT_REDIRECT)
                        continue;

                DPRINTF(NODE, ("\tgot redirect extent\n"));
                if (udf_node->num_extensions >= UDF_MAX_ALLOC_EXTENTS) {
                        DPRINTF(ALLOC, ("udf_get_node: implementation limit, "
                                        "too many allocation extensions on "
                                        "udf_node\n"));
                        error = EINVAL;
                        break;
                }

                /* length can only be *one* lb : UDF 2.50/2.3.7.1 */
                if (UDF_EXT_LEN(udf_rw32(icb_loc.len)) != lb_size) {
                        DPRINTF(ALLOC, ("udf_get_node: bad allocation "
                                        "extension size in udf_node\n"));
                        error = EINVAL;
                        break;
                }

                DPRINTF(NODE, ("read allocation extent at lb_num %d\n",
                        UDF_EXT_LEN(udf_rw32(icb_loc.loc.lb_num))));
                /* load in allocation extent */
                error = udf_read_logvol_dscr(ump, &icb_loc, &dscr);
                if (error || (dscr == NULL))
                        break;

                /* process read-in descriptor */
                dscr_type = udf_rw16(dscr->tag.id);

                if (dscr_type != TAGID_ALLOCEXTENT) {
                        udf_free_logvol_dscr(ump, &icb_loc, dscr);
                        error = ENOENT;
                        break;
                }

                DPRINTF(NODE, ("\trecording redirect extent\n"));
                udf_node->ext[udf_node->num_extensions] = &dscr->aee;
                udf_node->ext_loc[udf_node->num_extensions] = icb_loc;

                udf_node->num_extensions++;

        } /* while */
        UDF_UNLOCK_NODE(udf_node, 0);

        /* second round of cleanup code */
        if (error) {
                /* recycle udf_node */
                udf_dispose_node(udf_node);

                return EINVAL;          /* error code ok? */
        }

        DPRINTF(NODE, ("\tnode read in fine\n"));

        /*
         * Translate UDF filetypes into vnode types.
         *
         * Systemfiles like the meta main and mirror files are not treated as
         * normal files, so we type them as having no type. UDF dictates that
         * they are not allowed to be visible.
         */

        switch (udf_file_type) {
        case UDF_ICB_FILETYPE_DIRECTORY :
        case UDF_ICB_FILETYPE_STREAMDIR :
                vp->v_type = VDIR;
                break;
        case UDF_ICB_FILETYPE_BLOCKDEVICE :
                vp->v_type = VBLK;
                break;
        case UDF_ICB_FILETYPE_CHARDEVICE :
                vp->v_type = VCHR;
                break;
        case UDF_ICB_FILETYPE_SOCKET :
                vp->v_type = VSOCK;
                break;
        case UDF_ICB_FILETYPE_FIFO :
                vp->v_type = VFIFO;
                break;
        case UDF_ICB_FILETYPE_SYMLINK :
                vp->v_type = VLNK;
                break;
        case UDF_ICB_FILETYPE_VAT :
        case UDF_ICB_FILETYPE_META_MAIN :
        case UDF_ICB_FILETYPE_META_MIRROR :
                vp->v_type = VNON;
                break;
        case UDF_ICB_FILETYPE_RANDOMACCESS :
        case UDF_ICB_FILETYPE_REALTIME :
                vp->v_type = VREG;
                break;
        default:
                /* YIKES, something else */
                vp->v_type = VNON;
        }

        /* TODO specfs, fifofs etc etc. vnops setting */

        /* don't forget to set vnode's v_size */
        uvm_vnp_setsize(vp, file_size);

        /* TODO ext attr and streamdir udf_nodes */

        *new_key = &udf_node->loc.loc;

        return 0;
}

int
udf_get_node(struct udf_mount *ump, struct long_ad *node_icb_loc,
             struct udf_node **udf_noderes, int lktype)
{
        int error;
        struct vnode *vp;

        *udf_noderes = NULL;

        error = vcache_get(ump->vfs_mountp, &node_icb_loc->loc,
            sizeof(node_icb_loc->loc), &vp);
        if (error)
                return error;
        error = vn_lock(vp, lktype);
        if (error) {
                vrele(vp);
                return error;
        }
        *udf_noderes = VTOI(vp);
        return 0;
}

/* --------------------------------------------------------------------- */

int
udf_writeout_node(struct udf_node *udf_node, int waitfor)
{
        union dscrptr *dscr;
        struct long_ad *loc;
        int extnr, error;

        DPRINTF(NODE, ("udf_writeout_node called\n"));

        KASSERT(udf_node->outstanding_bufs == 0);
        KASSERT(udf_node->outstanding_nodedscr == 0);

        KASSERT(LIST_EMPTY(&udf_node->vnode->v_dirtyblkhd));

        if (udf_node->i_flags & IN_DELETED) {
                DPRINTF(NODE, ("\tnode deleted; not writing out\n"));
                udf_cleanup_reservation(udf_node);
                return 0;
        }

        /* lock node; unlocked in callback */
        UDF_LOCK_NODE(udf_node, 0);

        /* remove pending reservations, we're written out */
        udf_cleanup_reservation(udf_node);

        /* at least one descriptor writeout */
        udf_node->outstanding_nodedscr = 1;

        /* we're going to write out the descriptor so clear the flags */
        udf_node->i_flags &= ~(IN_MODIFIED | IN_ACCESSED);

        /* if we were rebuild, write out the allocation extents */
        if (udf_node->i_flags & IN_NODE_REBUILD) {
                /* mark outstanding node descriptors and issue them */
                udf_node->outstanding_nodedscr += udf_node->num_extensions;
                for (extnr = 0; extnr < udf_node->num_extensions; extnr++) {
                        loc = &udf_node->ext_loc[extnr];
                        dscr = (union dscrptr *) udf_node->ext[extnr];
                        error = udf_write_logvol_dscr(udf_node, dscr, loc, 0);
                        if (error)
                                return error;
                }
                /* mark allocation extents written out */
                udf_node->i_flags &= ~(IN_NODE_REBUILD);
        }

        if (udf_node->fe) {
                KASSERT(udf_node->efe == NULL);
                dscr = (union dscrptr *) udf_node->fe;
        } else {
                KASSERT(udf_node->efe);
                KASSERT(udf_node->fe == NULL);
                dscr = (union dscrptr *) udf_node->efe;
        }
        KASSERT(dscr);

        loc = &udf_node->write_loc;
        error = udf_write_logvol_dscr(udf_node, dscr, loc, waitfor);

        return error;
}

/* --------------------------------------------------------------------- */

int
udf_dispose_node(struct udf_node *udf_node)
{
        struct vnode *vp;
        int extnr;

        DPRINTF(NODE, ("udf_dispose_node called on node %p\n", udf_node));
        if (!udf_node) {
                DPRINTF(NODE, ("UDF: Dispose node on node NULL, ignoring\n"));
                return 0;
        }

        vp  = udf_node->vnode;
#ifdef DIAGNOSTIC
        if (vp->v_numoutput)
                panic("disposing UDF node with pending I/O's, udf_node = %p, "
                                "v_numoutput = %d", udf_node, vp->v_numoutput);
#endif

        udf_cleanup_reservation(udf_node);

        /* TODO extended attributes and streamdir */

        /* remove dirhash if present */
        dirhash_purge(&udf_node->dir_hash);

        /* destroy our lock */
        mutex_destroy(&udf_node->node_mutex);
        cv_destroy(&udf_node->node_lock);

        /* dissociate our udf_node from the vnode */
        genfs_node_destroy(udf_node->vnode);
        mutex_enter(vp->v_interlock);
        vp->v_data = NULL;
        mutex_exit(vp->v_interlock);

        /* free associated memory and the node itself */
        for (extnr = 0; extnr < udf_node->num_extensions; extnr++) {
                udf_free_logvol_dscr(udf_node->ump, &udf_node->ext_loc[extnr],
                        udf_node->ext[extnr]);
                udf_node->ext[extnr] = (void *) 0xdeadcccc;
        }

        if (udf_node->fe)
                udf_free_logvol_dscr(udf_node->ump, &udf_node->loc,
                        udf_node->fe);
        if (udf_node->efe)
                udf_free_logvol_dscr(udf_node->ump, &udf_node->loc,
                        udf_node->efe);

        udf_node->fe  = (void *) 0xdeadaaaa;
        udf_node->efe = (void *) 0xdeadbbbb;
        udf_node->ump = (void *) 0xdeadbeef;
        pool_put(&udf_node_pool, udf_node);

        return 0;
}



/*
 * create a new node using the specified dvp, vap and cnp.
 * This allows special files to be created. Use with care.
 */

int
udf_newvnode(struct mount *mp, struct vnode *dvp, struct vnode *vp,
    struct vattr *vap, kauth_cred_t cred, void *extra,
    size_t *key_len, const void **new_key)
{
        union dscrptr *dscr;
        struct udf_node *dir_node = VTOI(dvp);
        struct udf_node *udf_node;
        struct udf_mount *ump = dir_node->ump;
        struct long_ad node_icb_loc;
        uint64_t parent_unique_id;
        uint64_t lmapping;
        uint32_t lb_size, lb_num;
        uint16_t vpart_num;
        uid_t uid;
        gid_t gid, parent_gid;
        int (**vnodeops)(void *);
        int udf_file_type, fid_size, error;

        vnodeops = udf_vnodeop_p;
        udf_file_type = UDF_ICB_FILETYPE_RANDOMACCESS;

        switch (vap->va_type) {
        case VREG :
                udf_file_type = UDF_ICB_FILETYPE_RANDOMACCESS;
                break;
        case VDIR :
                udf_file_type = UDF_ICB_FILETYPE_DIRECTORY;
                break;
        case VLNK :
                udf_file_type = UDF_ICB_FILETYPE_SYMLINK;
                break;
        case VBLK :
                udf_file_type = UDF_ICB_FILETYPE_BLOCKDEVICE;
                /* specfs */
                return ENOTSUP;
                break;
        case VCHR :
                udf_file_type = UDF_ICB_FILETYPE_CHARDEVICE;
                /* specfs */
                return ENOTSUP;
                break;
        case VFIFO :
                udf_file_type = UDF_ICB_FILETYPE_FIFO;
                /* fifofs */
                return ENOTSUP;
                break;
        case VSOCK :
                udf_file_type = UDF_ICB_FILETYPE_SOCKET;
                return ENOTSUP;
                break;
        case VNON :
        case VBAD :
        default :
                /* nothing; can we even create these? */
                return EINVAL;
        }

        lb_size = udf_rw32(ump->logical_vol->lb_size);

        /* reserve space for one logical block */
        vpart_num = ump->node_part;
        error = udf_reserve_space(ump, NULL, UDF_C_NODE,
                vpart_num, 1, /* can_fail */ true);
        if (error)
                return error;

        /* allocate node */
        error = udf_allocate_space(ump, NULL, UDF_C_NODE,
                        vpart_num, 1, &lmapping);
        if (error) {
                udf_do_unreserve_space(ump, NULL, vpart_num, 1);
                return error;
        }

        lb_num = lmapping;

        /* initialise pointer to location */
        memset(&node_icb_loc, 0, sizeof(struct long_ad));
        node_icb_loc.len = udf_rw32(lb_size);
        node_icb_loc.loc.lb_num   = udf_rw32(lb_num);
        node_icb_loc.loc.part_num = udf_rw16(vpart_num);

        /* build udf_node (do initialise!) */
        udf_node = pool_get(&udf_node_pool, PR_WAITOK);
        memset(udf_node, 0, sizeof(struct udf_node));

        /* initialise crosslinks, note location of fe/efe for hashing */
        /* bugalert: synchronise with udf_get_node() */
        udf_node->ump       = ump;
        udf_node->vnode     = vp;
        vp->v_data          = udf_node;
        udf_node->loc       = node_icb_loc;
        udf_node->write_loc = node_icb_loc;
        udf_node->lockf     = 0;
        mutex_init(&udf_node->node_mutex, MUTEX_DEFAULT, IPL_NONE);
        cv_init(&udf_node->node_lock, "udf_nlk");
        udf_node->outstanding_bufs = 0;
        udf_node->outstanding_nodedscr = 0;
        udf_node->uncommitted_lbs = 0;

        vp->v_tag = VT_UDF;
        vp->v_op = vnodeops;

        /* initialise genfs */
        genfs_node_init(vp, &udf_genfsops);

        /* get parent's unique ID for referring '..' if its a directory */
        if (dir_node->fe) {
                parent_unique_id = udf_rw64(dir_node->fe->unique_id);
                parent_gid       = (gid_t) udf_rw32(dir_node->fe->gid);
        } else {
                parent_unique_id = udf_rw64(dir_node->efe->unique_id);
                parent_gid       = (gid_t) udf_rw32(dir_node->efe->gid);
        }

        /* get descriptor */
        udf_create_logvol_dscr(ump, udf_node, &node_icb_loc, &dscr);

        /* choose a fe or an efe for it */
        if (udf_rw16(ump->logical_vol->tag.descriptor_ver) == 2) {
                udf_node->fe = &dscr->fe;
                fid_size = udf_create_new_fe(ump, udf_node->fe,
                        udf_file_type, &udf_node->loc,
                        &dir_node->loc, parent_unique_id);
                /* TODO add extended attribute for creation time */
        } else {
                udf_node->efe = &dscr->efe;
                fid_size = udf_create_new_efe(ump, udf_node->efe,
                        udf_file_type, &udf_node->loc,
                        &dir_node->loc, parent_unique_id);
        }
        KASSERT(dscr->tag.tag_loc == udf_node->loc.loc.lb_num);

        /* update vnode's size and type */
        vp->v_type = vap->va_type;
        uvm_vnp_setsize(vp, fid_size);

        /* set access mode */
        udf_setaccessmode(udf_node, vap->va_mode);

        /* set ownership */
        uid = kauth_cred_geteuid(cred);
        gid = parent_gid;
        udf_setownership(udf_node, uid, gid);

        *key_len = sizeof(udf_node->loc.loc);
        *new_key = &udf_node->loc.loc;

        return 0;
}


int
udf_create_node(struct vnode *dvp, struct vnode **vpp, struct vattr *vap,
        struct componentname *cnp)
{
        struct udf_node *udf_node, *dir_node = VTOI(dvp);
        struct udf_mount *ump = dir_node->ump;
        int error;

        error = vcache_new(dvp->v_mount, dvp, vap, cnp->cn_cred, NULL, vpp);
        if (error)
                return error;

        udf_node = VTOI(*vpp);
        error = udf_dir_attach(ump, dir_node, udf_node, vap, cnp);
        if (error) {
                struct long_ad *node_icb_loc = &udf_node->loc;
                uint32_t lb_num = udf_rw32(node_icb_loc->loc.lb_num);
                uint16_t vpart_num = udf_rw16(node_icb_loc->loc.part_num);

                /* free disc allocation for node */
                udf_free_allocated_space(ump, lb_num, vpart_num, 1);

                /* recycle udf_node */
                udf_dispose_node(udf_node);
                vrele(*vpp);

                *vpp = NULL;
                return error;
        }

        /* adjust file count */
        udf_adjust_filecount(udf_node, 1);

        cache_enter(dvp, *vpp, cnp->cn_nameptr, cnp->cn_namelen, cnp->cn_flags);
        return 0;
}

/* --------------------------------------------------------------------- */

static void
udf_free_descriptor_space(struct udf_node *udf_node, struct long_ad *loc, void *mem)
{
        struct udf_mount *ump = udf_node->ump;
        uint32_t lb_size, lb_num, len, num_lb;
        uint16_t vpart_num;

        /* is there really one? */
        if (mem == NULL)
                return;

        /* got a descriptor here */
        len       = UDF_EXT_LEN(udf_rw32(loc->len));
        lb_num    = udf_rw32(loc->loc.lb_num);
        vpart_num = udf_rw16(loc->loc.part_num);

        lb_size = udf_rw32(ump->logical_vol->lb_size);
        num_lb = (len + lb_size -1) / lb_size;

        udf_free_allocated_space(ump, lb_num, vpart_num, num_lb);
}

void
udf_delete_node(struct udf_node *udf_node)
{
        void *dscr;
        struct long_ad *loc;
        int extnr, lvint, dummy;

        if (udf_node->i_flags & IN_NO_DELETE)
                return;

        /* paranoia check on integrity; should be open!; we could panic */
        lvint = udf_rw32(udf_node->ump->logvol_integrity->integrity_type);
        if (lvint == UDF_INTEGRITY_CLOSED)
                printf("\tIntegrity was CLOSED!\n");

        /* whatever the node type, change its size to zero */
        (void) udf_resize_node(udf_node, 0, &dummy);

        /* force it to be `clean'; no use writing it out */
        udf_node->i_flags &= ~(IN_MODIFIED | IN_ACCESSED | IN_ACCESS |
                IN_CHANGE | IN_UPDATE | IN_MODIFY);

        /* adjust file count */
        udf_adjust_filecount(udf_node, -1);

        /*
         * Free its allocated descriptors; memory will be released when
         * vop_reclaim() is called.
         */
        loc = &udf_node->loc;

        dscr = udf_node->fe;
        udf_free_descriptor_space(udf_node, loc, dscr);
        dscr = udf_node->efe;
        udf_free_descriptor_space(udf_node, loc, dscr);

        for (extnr = 0; extnr < UDF_MAX_ALLOC_EXTENTS; extnr++) {
                dscr =  udf_node->ext[extnr];
                loc  = &udf_node->ext_loc[extnr];
                udf_free_descriptor_space(udf_node, loc, dscr);
        }
}

/* --------------------------------------------------------------------- */

/* set new filesize; node but be LOCKED on entry and is locked on exit */
int
udf_resize_node(struct udf_node *udf_node, uint64_t new_size, int *extended)
{
        struct file_entry    *fe  = udf_node->fe;
        struct extfile_entry *efe = udf_node->efe;
        uint64_t file_size;
        int error;

        if (fe) {
                file_size  = udf_rw64(fe->inf_len);
        } else {
                assert(udf_node->efe);
                file_size  = udf_rw64(efe->inf_len);
        }

        DPRINTF(ATTR, ("\tchanging file length from %"PRIu64" to %"PRIu64"\n",
                        file_size, new_size));

        /* if not changing, we're done */
        if (file_size == new_size)
                return 0;

        *extended = (new_size > file_size);
        if (*extended) {
                error = udf_grow_node(udf_node, new_size);
        } else {
                error = udf_shrink_node(udf_node, new_size);
        }

        return error;
}


/* --------------------------------------------------------------------- */

void
udf_itimes(struct udf_node *udf_node, struct timespec *acc,
        struct timespec *mod, struct timespec *birth)
{
        struct timespec now;
        struct file_entry    *fe;
        struct extfile_entry *efe;
        struct filetimes_extattr_entry *ft_extattr;
        struct timestamp *atime, *mtime, *attrtime, *ctime;
        struct timestamp  fe_ctime;
        struct timespec   cur_birth;
        uint32_t offset, a_l;
        uint8_t *filedata;
        int error;

        /* protect against rogue values */
        if (!udf_node)
                return;

        fe  = udf_node->fe;
        efe = udf_node->efe;

        if (!(udf_node->i_flags & (IN_ACCESS|IN_CHANGE|IN_UPDATE|IN_MODIFY)))
                return;

        /* get descriptor information */
        if (fe) {
                atime    = &fe->atime;
                mtime    = &fe->mtime;
                attrtime = &fe->attrtime;
                filedata = fe->data;

                /* initial save dummy setting */
                ctime    = &fe_ctime;

                /* check our extended attribute if present */
                error = udf_extattr_search_intern(udf_node,
                        UDF_FILETIMES_ATTR_NO, "", &offset, &a_l);
                if (!error) {
                        ft_extattr = (struct filetimes_extattr_entry *)
                                (filedata + offset);
                        if (ft_extattr->existence & UDF_FILETIMES_FILE_CREATION)
                                ctime = &ft_extattr->times[0];
                }
                /* TODO create the extended attribute if not found ? */
        } else {
                assert(udf_node->efe);
                atime    = &efe->atime;
                mtime    = &efe->mtime;
                attrtime = &efe->attrtime;
                ctime    = &efe->ctime;
        }

        vfs_timestamp(&now);

        /* set access time */
        if (udf_node->i_flags & IN_ACCESS) {
                if (acc == NULL)
                        acc = &now;
                udf_timespec_to_timestamp(acc, atime);
        }

        /* set modification time */
        if (udf_node->i_flags & (IN_UPDATE | IN_MODIFY)) {
                if (mod == NULL)
                        mod = &now;
                udf_timespec_to_timestamp(mod, mtime);

                /* ensure birthtime is older than set modification! */
                udf_timestamp_to_timespec(udf_node->ump, ctime, &cur_birth);
                if ((cur_birth.tv_sec > mod->tv_sec) ||
                          ((cur_birth.tv_sec == mod->tv_sec) &&
                             (cur_birth.tv_nsec > mod->tv_nsec))) {
                        udf_timespec_to_timestamp(mod, ctime);
                }
        }

        /* update birthtime if specified */
        /* XXX we assume here that given birthtime is older than mod */
        if (birth && (birth->tv_sec != VNOVAL)) {
                udf_timespec_to_timestamp(birth, ctime);
        }

        /* set change time */
        if (udf_node->i_flags & (IN_CHANGE | IN_MODIFY))
                udf_timespec_to_timestamp(&now, attrtime);

        /* notify updates to the node itself */
        if (udf_node->i_flags & (IN_ACCESS | IN_MODIFY))
                udf_node->i_flags |= IN_ACCESSED;
        if (udf_node->i_flags & (IN_UPDATE | IN_CHANGE))
                udf_node->i_flags |= IN_MODIFIED;

        /* clear modification flags */
        udf_node->i_flags &= ~(IN_ACCESS | IN_CHANGE | IN_UPDATE | IN_MODIFY);
}

/* --------------------------------------------------------------------- */

int
udf_update(struct vnode *vp, struct timespec *acc,
        struct timespec *mod, struct timespec *birth, int updflags)
{
        union dscrptr *dscrptr;
        struct udf_node  *udf_node = VTOI(vp);
        struct udf_mount *ump = udf_node->ump;
        struct regid     *impl_id;
        int mnt_async = (vp->v_mount->mnt_flag & MNT_ASYNC);
        int waitfor, flags;

#ifdef DEBUG
        char bits[128];
        DPRINTF(CALL, ("udf_update(node, %p, %p, %p, %d)\n", acc, mod, birth,
                updflags));
        snprintb(bits, sizeof(bits), IN_FLAGBITS, udf_node->i_flags);
        DPRINTF(CALL, ("\tnode flags %s\n", bits));
        DPRINTF(CALL, ("\t\tmnt_async = %d\n", mnt_async));
#endif

        /* set our times */
        udf_itimes(udf_node, acc, mod, birth);

        /* set our implementation id */
        if (udf_node->fe) {
                dscrptr = (union dscrptr *) udf_node->fe;
                impl_id = &udf_node->fe->imp_id;
        } else {
                dscrptr = (union dscrptr *) udf_node->efe;
                impl_id = &udf_node->efe->imp_id;
        }

        /* set our ID */
        udf_set_regid(impl_id, IMPL_NAME);
        udf_add_impl_regid(ump, impl_id);

        /* update our crc! on RMW we are not allowed to change a thing */
        udf_validate_tag_and_crc_sums(dscrptr);

        /* if called when mounted readonly, never write back */
        if (vp->v_mount->mnt_flag & MNT_RDONLY)
                return 0;

        /* check if the node is dirty 'enough'*/
        if (updflags & UPDATE_CLOSE) {
                flags = udf_node->i_flags & (IN_MODIFIED | IN_ACCESSED);
        } else {
                flags = udf_node->i_flags & IN_MODIFIED;
        }
        if (flags == 0)
                return 0;

        /* determine if we need to write sync or async */
        waitfor = 0;
        if ((flags & IN_MODIFIED) && (mnt_async == 0)) {
                /* sync mounted */
                waitfor = updflags & UPDATE_WAIT;
                if (updflags & UPDATE_DIROP)
                        waitfor |= UPDATE_WAIT;
        }
        if (waitfor)
                return VOP_FSYNC(vp, FSCRED, FSYNC_WAIT, 0,0);

        return 0;
}


/* --------------------------------------------------------------------- */


/*
 * Read one fid and process it into a dirent and advance to the next (*fid)
 * has to be allocated a logical block in size, (*dirent) struct dirent length
 */

int
udf_read_fid_stream(struct vnode *vp, uint64_t *offset,
                struct fileid_desc *fid, struct dirent *dirent)
{
        struct udf_node  *dir_node = VTOI(vp);
        struct udf_mount *ump = dir_node->ump;
        struct file_entry    *fe  = dir_node->fe;
        struct extfile_entry *efe = dir_node->efe;
        uint32_t      fid_size, lb_size;
        uint64_t      file_size;
        char         *fid_name;
        int           enough, error;

        assert(fid);
        assert(dirent);
        assert(dir_node);
        assert(offset);
        assert(*offset != 1);

        DPRINTF(FIDS, ("read_fid_stream called at offset %"PRIu64"\n", *offset));
        /* check if we're past the end of the directory */
        if (fe) {
                file_size = udf_rw64(fe->inf_len);
        } else {
                assert(dir_node->efe);
                file_size = udf_rw64(efe->inf_len);
        }
        if (*offset >= file_size)
                return EINVAL;

        /* get maximum length of FID descriptor */
        lb_size = udf_rw32(ump->logical_vol->lb_size);

        /* initialise return values */
        fid_size = 0;
        memset(dirent, 0, sizeof(struct dirent));
        memset(fid, 0, lb_size);

        enough  = (file_size - (*offset) >= UDF_FID_SIZE);
        if (!enough) {
                /* short dir ... */
                return EIO;
        }

        error = vn_rdwr(UIO_READ, vp,
                        fid, MIN(file_size - (*offset), lb_size), *offset,
                        UIO_SYSSPACE, IO_ALTSEMANTICS | IO_NODELOCKED, FSCRED,
                        NULL, NULL);
        if (error)
                return error;

        DPRINTF(FIDS, ("\tfid piece read in fine\n"));
        /*
         * Check if we got a whole descriptor.
         * TODO Try to `resync' directory stream when something is very wrong.
         */

        /* check if our FID header is OK */
        error = udf_check_tag(fid);
        if (error) {
                goto brokendir;
        }
        DPRINTF(FIDS, ("\ttag check ok\n"));

        if (udf_rw16(fid->tag.id) != TAGID_FID) {
                error = EIO;
                goto brokendir;
        }
        DPRINTF(FIDS, ("\ttag checked ok: got TAGID_FID\n"));

        /* check for length */
        fid_size = udf_fidsize(fid);
        enough = (file_size - (*offset) >= fid_size);
        if (!enough) {
                error = EIO;
                goto brokendir;
        }
        DPRINTF(FIDS, ("\tthe complete fid is read in\n"));

        /* check FID contents */
        error = udf_check_tag_payload((union dscrptr *) fid, lb_size);
brokendir:
        if (error) {
                /* note that is sometimes a bit quick to report */
                printf("UDF: BROKEN DIRECTORY ENTRY\n");
                /* RESYNC? */
                /* TODO: use udf_resync_fid_stream */
                return EIO;
        }
        DPRINTF(FIDS, ("\tpayload checked ok\n"));

        /* we got a whole and valid descriptor! */
        DPRINTF(FIDS, ("\tinterpret FID\n"));

        /* create resulting dirent structure */
        fid_name = (char *) fid->data + udf_rw16(fid->l_iu);
        udf_to_unix_name(dirent->d_name, NAME_MAX,
                fid_name, fid->l_fi, &ump->logical_vol->desc_charset);

        /* '..' has no name, so provide one */
        if (fid->file_char & UDF_FILE_CHAR_PAR)
                strcpy(dirent->d_name, "..");

        dirent->d_fileno = udf_get_node_id(&fid->icb);  /* inode hash XXX */
        dirent->d_namlen = strlen(dirent->d_name);
        dirent->d_reclen = _DIRENT_SIZE(dirent);

        /*
         * Note that its not worth trying to go for the filetypes now... its
         * too expensive too
         */
        dirent->d_type = DT_UNKNOWN;

        /* initial guess for filetype we can make */
        if (fid->file_char & UDF_FILE_CHAR_DIR)
                dirent->d_type = DT_DIR;

        /* advance */
        *offset += fid_size;

        return error;
}


/* --------------------------------------------------------------------- */

static void
udf_sync_pass(struct udf_mount *ump, kauth_cred_t cred, int pass, int *ndirty)
{
        struct udf_node *udf_node, *n_udf_node;
        struct vnode *vp;
        int vdirty, error;

        KASSERT(mutex_owned(&ump->sync_lock));

        DPRINTF(SYNC, ("sync_pass %d\n", pass));
        udf_node = RB_TREE_MIN(&ump->udf_node_tree);
        for (;udf_node; udf_node = n_udf_node) {
                DPRINTF(SYNC, ("."));

                vp = udf_node->vnode;

                n_udf_node = rb_tree_iterate(&ump->udf_node_tree,
                    udf_node, RB_DIR_RIGHT);

                error = vn_lock(vp, LK_EXCLUSIVE | LK_NOWAIT);
                if (error) {
                        KASSERT(error == EBUSY);
                        *ndirty += 1;
                        continue;
                }

                switch (pass) {
                case 1:
                        VOP_FSYNC(vp, cred, 0 | FSYNC_DATAONLY,0,0);
                        break;
                case 2:
                        vdirty = vp->v_numoutput;
                        if (vp->v_tag == VT_UDF)
                                vdirty += udf_node->outstanding_bufs +
                                        udf_node->outstanding_nodedscr;
                        if (vdirty == 0)
                                VOP_FSYNC(vp, cred, 0,0,0);
                        *ndirty += vdirty;
                        break;
                case 3:
                        vdirty = vp->v_numoutput;
                        if (vp->v_tag == VT_UDF)
                                vdirty += udf_node->outstanding_bufs +
                                        udf_node->outstanding_nodedscr;
                        *ndirty += vdirty;
                        break;
                }

                VOP_UNLOCK(vp);
        }
        DPRINTF(SYNC, ("END sync_pass %d\n", pass));
}


static bool
udf_sync_selector(void *cl, struct vnode *vp)
{
        struct udf_node *udf_node;

        KASSERT(mutex_owned(vp->v_interlock));

        udf_node = VTOI(vp);

        if (vp->v_vflag & VV_SYSTEM)
                return false;
        if (vp->v_type == VNON)
                return false;
        if (udf_node == NULL)
                return false;
        if ((udf_node->i_flags & (IN_ACCESSED | IN_UPDATE | IN_MODIFIED)) == 0)
                return false;
        if (LIST_EMPTY(&vp->v_dirtyblkhd) && (vp->v_iflag & VI_ONWORKLST) == 0)
                return false;

        return true;
}

void
udf_do_sync(struct udf_mount *ump, kauth_cred_t cred, int waitfor)
{
        struct vnode_iterator *marker;
        struct vnode *vp;
        struct udf_node *udf_node, *udf_next_node;
        int dummy, ndirty;

        if (waitfor == MNT_LAZY)
                return;

        mutex_enter(&ump->sync_lock);

        /* Fill the rbtree with nodes to sync. */
        vfs_vnode_iterator_init(ump->vfs_mountp, &marker);
        while ((vp = vfs_vnode_iterator_next(marker,
            udf_sync_selector, NULL)) != NULL) {
                udf_node = VTOI(vp);
                udf_node->i_flags |= IN_SYNCED;
                rb_tree_insert_node(&ump->udf_node_tree, udf_node);
        }
        vfs_vnode_iterator_destroy(marker);

        dummy = 0;
        DPRINTF(CALL, ("issue VOP_FSYNC(DATA only) on all nodes\n"));
        DPRINTF(SYNC, ("issue VOP_FSYNC(DATA only) on all nodes\n"));
        udf_sync_pass(ump, cred, 1, &dummy);

        DPRINTF(CALL, ("issue VOP_FSYNC(COMPLETE) on all finished nodes\n"));
        DPRINTF(SYNC, ("issue VOP_FSYNC(COMPLETE) on all finished nodes\n"));
        udf_sync_pass(ump, cred, 2, &dummy);

        if (waitfor == MNT_WAIT) {
recount:
                ndirty = ump->devvp->v_numoutput;
                DPRINTF(SYNC, ("counting pending blocks: on devvp %d\n",
                        ndirty));
                udf_sync_pass(ump, cred, 3, &ndirty);
                DPRINTF(SYNC, ("counted num dirty pending blocks %d\n",
                        ndirty));

                if (ndirty) {
                        /* 1/4 second wait */
                        kpause("udfsync2", false, hz/4, NULL);
                        goto recount;
                }
        }

        /* Clean the rbtree. */
        for (udf_node = RB_TREE_MIN(&ump->udf_node_tree);
            udf_node; udf_node = udf_next_node) {
                udf_next_node = rb_tree_iterate(&ump->udf_node_tree,
                    udf_node, RB_DIR_RIGHT);
                rb_tree_remove_node(&ump->udf_node_tree, udf_node);
                udf_node->i_flags &= ~IN_SYNCED;
                vrele(udf_node->vnode);
        }

        mutex_exit(&ump->sync_lock);
}

/* --------------------------------------------------------------------- */

/*
 * Read and write file extent in/from the buffer.
 *
 * The splitup of the extent into separate request-buffers is to minimise
 * copying around as much as possible.
 *
 * block based file reading and writing
 */

static int
udf_read_internal(struct udf_node *node, uint8_t *blob)
{
        struct udf_mount *ump;
        struct file_entry     *fe = node->fe;
        struct extfile_entry *efe = node->efe;
        uint64_t inflen;
        uint32_t sector_size;
        uint8_t  *srcpos;
        int icbflags, addr_type;

        /* get extent and do some paranoia checks */
        ump = node->ump;
        sector_size = ump->discinfo.sector_size;

        /*
         * XXX there should be real bounds-checking logic here,
         * in case ->l_ea or ->inf_len contains nonsense.
         */

        if (fe) {
                inflen   = udf_rw64(fe->inf_len);
                srcpos   = &fe->data[0] + udf_rw32(fe->l_ea);
                icbflags = udf_rw16(fe->icbtag.flags);
        } else {
                assert(node->efe);
                inflen   = udf_rw64(efe->inf_len);
                srcpos   = &efe->data[0] + udf_rw32(efe->l_ea);
                icbflags = udf_rw16(efe->icbtag.flags);
        }
        addr_type = icbflags & UDF_ICB_TAG_FLAGS_ALLOC_MASK;

        assert(addr_type == UDF_ICB_INTERN_ALLOC);
        __USE(addr_type);
        assert(inflen < sector_size);

        /* copy out info */
        memcpy(blob, srcpos, inflen);
        memset(&blob[inflen], 0, sector_size - inflen);

        return 0;
}


static int
udf_write_internal(struct udf_node *node, uint8_t *blob)
{
        struct udf_mount *ump;
        struct file_entry     *fe = node->fe;
        struct extfile_entry *efe = node->efe;
        uint64_t inflen;
        uint32_t sector_size;
        uint8_t  *pos;
        int icbflags, addr_type;

        /* get extent and do some paranoia checks */
        ump = node->ump;
        sector_size = ump->discinfo.sector_size;

        if (fe) {
                inflen   = udf_rw64(fe->inf_len);
                pos      = &fe->data[0] + udf_rw32(fe->l_ea);
                icbflags = udf_rw16(fe->icbtag.flags);
        } else {
                assert(node->efe);
                inflen   = udf_rw64(efe->inf_len);
                pos      = &efe->data[0] + udf_rw32(efe->l_ea);
                icbflags = udf_rw16(efe->icbtag.flags);
        }
        addr_type = icbflags & UDF_ICB_TAG_FLAGS_ALLOC_MASK;

        assert(addr_type == UDF_ICB_INTERN_ALLOC);
        __USE(addr_type);
        assert(inflen < sector_size);
        __USE(sector_size);

        /* copy in blob */
        /* memset(pos, 0, inflen); */
        memcpy(pos, blob, inflen);

        return 0;
}


void
udf_read_filebuf(struct udf_node *udf_node, struct buf *buf)
{
        struct buf *nestbuf;
        struct udf_mount *ump = udf_node->ump;
        uint64_t   *mapping;
        uint64_t    run_start;
        uint32_t    sector_size;
        uint32_t    buf_offset, sector, rbuflen, rblk;
        uint32_t    from, lblkno;
        uint32_t    sectors;
        uint8_t    *buf_pos;
        int error, run_length, what;

        sector_size = udf_node->ump->discinfo.sector_size;

        from    = buf->b_blkno;
        sectors = buf->b_bcount / sector_size;

        what = udf_get_c_type(udf_node);

        /* assure we have enough translation slots */
        KASSERT(buf->b_bcount / sector_size <= UDF_MAX_MAPPINGS);
        KASSERT(MAXPHYS / sector_size <= UDF_MAX_MAPPINGS);

        if (sectors > UDF_MAX_MAPPINGS) {
                printf("udf_read_filebuf: implementation limit on bufsize\n");
                buf->b_error  = EIO;
                biodone(buf);
                return;
        }

        mapping = malloc(sizeof(*mapping) * UDF_MAX_MAPPINGS, M_TEMP, M_WAITOK);

        error = 0;
        DPRINTF(READ, ("\ttranslate %d-%d\n", from, sectors));
        error = udf_translate_file_extent(udf_node, from, sectors, mapping);
        if (error) {
                buf->b_error  = error;
                biodone(buf);
                goto out;
        }
        DPRINTF(READ, ("\ttranslate extent went OK\n"));

        /* pre-check if its an internal */
        if (*mapping == UDF_TRANS_INTERN) {
                error = udf_read_internal(udf_node, (uint8_t *) buf->b_data);
                if (error)
                        buf->b_error  = error;
                biodone(buf);
                goto out;
        }
        DPRINTF(READ, ("\tnot intern\n"));

#ifdef DEBUG
        if (udf_verbose & UDF_DEBUG_TRANSLATE) {
                printf("Returned translation table:\n");
                for (sector = 0; sector < sectors; sector++) {
                        printf("%d : %"PRIu64"\n", sector, mapping[sector]);
                }
        }
#endif

        /* request read-in of data from disc scheduler */
        buf->b_resid = buf->b_bcount;
        for (sector = 0; sector < sectors; sector++) {
                buf_offset = sector * sector_size;
                buf_pos    = (uint8_t *) buf->b_data + buf_offset;
                DPRINTF(READ, ("\tprocessing rel sector %d\n", sector));

                /* check if its zero or unmapped to stop reading */
                switch (mapping[sector]) {
                case UDF_TRANS_UNMAPPED:
                case UDF_TRANS_ZERO:
                        /* copy zero sector TODO runlength like below */
                        memset(buf_pos, 0, sector_size);
                        DPRINTF(READ, ("\treturning zero sector\n"));
                        nestiobuf_done(buf, sector_size, 0);
                        break;
                default :
                        DPRINTF(READ, ("\tread sector "
                            "%"PRIu64"\n", mapping[sector]));

                        lblkno = from + sector;
                        run_start  = mapping[sector];
                        run_length = 1;
                        while (sector < sectors-1) {
                                if (mapping[sector+1] != mapping[sector]+1)
                                        break;
                                run_length++;
                                sector++;
                        }

                        /*
                         * nest an iobuf and mark it for async reading. Since
                         * we're using nested buffers, they can't be cached by
                         * design.
                         */
                        rbuflen = run_length * sector_size;
                        rblk    = run_start  * (sector_size/DEV_BSIZE);

                        nestbuf = getiobuf(NULL, true);
                        nestiobuf_setup(buf, nestbuf, buf_offset, rbuflen);
                        /* nestbuf is B_ASYNC */

                        /* identify this nestbuf */
                        nestbuf->b_lblkno   = lblkno;
                        assert(nestbuf->b_vp == udf_node->vnode);

                        /* CD schedules on raw blkno */
                        nestbuf->b_blkno      = rblk;
                        nestbuf->b_proc       = NULL;
                        nestbuf->b_rawblkno   = rblk;
                        nestbuf->b_udf_c_type = what;

                        udf_discstrat_queuebuf(ump, nestbuf);
                }
        }
out:
        /* if we're synchronously reading, wait for the completion */
        if ((buf->b_flags & B_ASYNC) == 0)
                biowait(buf);

        DPRINTF(READ, ("\tend of read_filebuf\n"));
        free(mapping, M_TEMP);
        return;
}


void
udf_write_filebuf(struct udf_node *udf_node, struct buf *buf)
{
        struct buf *nestbuf;
        struct udf_mount *ump = udf_node->ump;
        uint64_t   *mapping;
        uint64_t    run_start;
        uint32_t    lb_size;
        uint32_t    buf_offset, lb_num, rbuflen, rblk;
        uint32_t    from, lblkno;
        uint32_t    num_lb;
        int error, run_length, what, s;

        lb_size = udf_rw32(udf_node->ump->logical_vol->lb_size);

        from   = buf->b_blkno;
        num_lb = buf->b_bcount / lb_size;

        what = udf_get_c_type(udf_node);

        /* assure we have enough translation slots */
        KASSERT(buf->b_bcount / lb_size <= UDF_MAX_MAPPINGS);
        KASSERT(MAXPHYS / lb_size <= UDF_MAX_MAPPINGS);

        if (num_lb > UDF_MAX_MAPPINGS) {
                printf("udf_write_filebuf: implementation limit on bufsize\n");
                buf->b_error  = EIO;
                biodone(buf);
                return;
        }

        mapping = malloc(sizeof(*mapping) * UDF_MAX_MAPPINGS, M_TEMP, M_WAITOK);

        error = 0;
        DPRINTF(WRITE, ("\ttranslate %d-%d\n", from, num_lb));
        error = udf_translate_file_extent(udf_node, from, num_lb, mapping);
        if (error) {
                buf->b_error  = error;
                biodone(buf);
                goto out;
        }
        DPRINTF(WRITE, ("\ttranslate extent went OK\n"));

        /* if its internally mapped, we can write it in the descriptor itself */
        if (*mapping == UDF_TRANS_INTERN) {
                /* TODO paranoia check if we ARE going to have enough space */
                error = udf_write_internal(udf_node, (uint8_t *) buf->b_data);
                if (error)
                        buf->b_error  = error;
                biodone(buf);
                goto out;
        }
        DPRINTF(WRITE, ("\tnot intern\n"));

        /* request write out of data to disc scheduler */
        buf->b_resid = buf->b_bcount;
        for (lb_num = 0; lb_num < num_lb; lb_num++) {
                buf_offset = lb_num * lb_size;
                DPRINTF(WRITE, ("\tprocessing rel lb_num %d\n", lb_num));

                /*
                 * Mappings are not that important here. Just before we write
                 * the lb_num we late-allocate them when needed and update the
                 * mapping in the udf_node.
                 */

                /* XXX why not ignore the mapping altogether ? */
                DPRINTF(WRITE, ("\twrite lb_num "
                    "%"PRIu64, mapping[lb_num]));

                lblkno = from + lb_num;
                run_start  = mapping[lb_num];
                run_length = 1;
                while (lb_num < num_lb-1) {
                        if (mapping[lb_num+1] != mapping[lb_num]+1)
                                if (mapping[lb_num+1] != mapping[lb_num])
                                        break;
                        run_length++;
                        lb_num++;
                }
                DPRINTF(WRITE, ("+ %d\n", run_length));

                /* nest an iobuf on the master buffer for the extent */
                rbuflen = run_length * lb_size;
                rblk = run_start * (lb_size/DEV_BSIZE);

                nestbuf = getiobuf(NULL, true);
                nestiobuf_setup(buf, nestbuf, buf_offset, rbuflen);
                /* nestbuf is B_ASYNC */

                /* identify this nestbuf */
                nestbuf->b_lblkno   = lblkno;
                KASSERT(nestbuf->b_vp == udf_node->vnode);

                /* CD schedules on raw blkno */
                nestbuf->b_blkno      = rblk;
                nestbuf->b_proc       = NULL;
                nestbuf->b_rawblkno   = rblk;
                nestbuf->b_udf_c_type = what;

                /* increment our outstanding bufs counter */
                s = splbio();
                        udf_node->outstanding_bufs++;
                splx(s);

                udf_discstrat_queuebuf(ump, nestbuf);
        }
out:
        /* if we're synchronously writing, wait for the completion */
        if ((buf->b_flags & B_ASYNC) == 0)
                biowait(buf);

        DPRINTF(WRITE, ("\tend of write_filebuf\n"));
        free(mapping, M_TEMP);
        return;
}

/* --------------------------------------------------------------------- */