Module Name:    src
Committed By:   reinoud
Date:           Wed Apr  6 13:35:50 UTC 2022

Added Files:
        src/sbin/fsck_udf: Makefile fsck_udf.8 main.c

Log Message:
Initial commit of the fsck_udf(8) utility that checks and repairs UDF
filesystems on optical media as well as on disc images, harddisc partitions
and wedges.


To generate a diff of this commit:
cvs rdiff -u -r0 -r1.1 src/sbin/fsck_udf/Makefile \
    src/sbin/fsck_udf/fsck_udf.8 src/sbin/fsck_udf/main.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.

Added files:

Index: src/sbin/fsck_udf/Makefile
diff -u /dev/null src/sbin/fsck_udf/Makefile:1.1
--- /dev/null	Wed Apr  6 13:35:50 2022
+++ src/sbin/fsck_udf/Makefile	Wed Apr  6 13:35:50 2022
@@ -0,0 +1,23 @@
+#	$NetBSD: Makefile,v 1.1 2022/04/06 13:35:50 reinoud Exp $
+
+.include <bsd.own.mk>
+
+PROG=	fsck_udf
+MAN=	fsck_udf.8
+SRCS=	main.c udf_core.c \
+	udf_osta.c fattr.c fsutil.c
+
+FSCK=	${NETBSDSRCDIR}/sbin/fsck
+NEWFS=	${NETBSDSRCDIR}/sbin/newfs_udf
+MOUNT=	${NETBSDSRCDIR}/sbin/mount
+KUDF=	${NETBSDSRCDIR}/sys/fs/udf
+CPPFLAGS+= -I${FSCK} -I${KUDF} -I${NEWFS} -I${NETBSDSRCDIR}/sys
+.PATH:	${FSCK} ${NEWFS} ${MOUNT} ${KUDF}
+
+DPADD+=${LIBUTIL}
+LDADD+=-lutil -lprop
+
+CWARNFLAGS.clang+=	-Wno-error=address-of-packed-member
+CWARNFLAGS.gcc+=	${GCC_NO_ADDR_OF_PACKED_MEMBER}
+
+.include <bsd.prog.mk>
Index: src/sbin/fsck_udf/fsck_udf.8
diff -u /dev/null src/sbin/fsck_udf/fsck_udf.8:1.1
--- /dev/null	Wed Apr  6 13:35:50 2022
+++ src/sbin/fsck_udf/fsck_udf.8	Wed Apr  6 13:35:50 2022
@@ -0,0 +1,115 @@
+.\"	$NetBSD: fsck_udf.8,v 1.1 2022/04/06 13:35:50 reinoud Exp $
+.\"
+.\" Copyright (C) 2022 Reinoud Zandijk
+.\" Based on fsck_msdos(8) by
+.\"     Copyright (C) 1995 Wolfgang Solfrank
+.\"     Copyright (c) 1995 Martin Husemann
+.\"
+.\" 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 AUTHORS ``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 AUTHORS 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.
+.\"
+.\"
+.Dd February 6, 2022
+.Dt FSCK_UDF 8
+.Os
+.Sh NAME
+.Nm fsck_udf
+.Nd Universal Disk Format filesystem consistency checker
+.Sh SYNOPSIS
+.Nm
+.Fl p
+.Op Fl fH
+.Ar filesystem ...
+.Nm
+.Op Fl sSynfH
+.Ar filesystem ...
+.Sh DESCRIPTION
+The
+.Nm
+utility verifies and repairs
+.Tn Universal Disk Format
+filesystems (more commonly known as
+.Tn UDF
+filesystems).
+.Pp
+The first form of
+.Nm
+preens the specified filesystems.
+It is normally started by
+.Xr fsck 8
+run from
+.Pa /etc/rc
+during automatic reboot, when an UDF filesystem is detected.
+When preening file systems,
+.Nm
+will fix common inconsistencies non-interactively.
+If more serious problems are found,
+.Nm
+does not try to fix them, indicates that it was not
+successful, and exits.
+.Pp
+The second form of
+.Nm
+checks the specified file systems and tries to repair all
+detected inconsistencies, requesting confirmation before
+making any changes.
+.Pp
+The options are as follows:
+.Bl -tag -width XXXoptions
+.It Fl f
+Force detailed checking even when file system is marked closed.
+.It Fl n
+Causes
+.Nm
+to assume no as the answer to all operator
+questions.
+.It Fl p
+Preen the specified filesystems.
+.It Fl y
+Causes
+.Nm
+to assume yes as the answer to all operator questions.
+.It Fl s Ar session
+Select session
+.Ar session
+to be checked on recordable media. This allows older sessions
+of the file system on recordable media to be recovered.
+.It Fl S
+Causes
+.Nm
+to scan for older VAT tables on recordable media. This allows older snapshots
+of the file system on recordable media to be recovered.
+.It Fl H
+Enables heuristic repair options repairing known corruptions in the wild
+caused by bugs.
+.El
+.Sh SEE ALSO
+.Xr fsck 8 ,
+.Xr fsck_ffs 8 ,
+.Xr mount_udf 8
+.Sh HISTORY
+A
+.Nm
+utility appeared in
+.Nx 10.0 .
+.Sh BUGS
+.Nm
+is still under construction. Not all possible reparations are implemented.
+
Index: src/sbin/fsck_udf/main.c
diff -u /dev/null src/sbin/fsck_udf/main.c:1.1
--- /dev/null	Wed Apr  6 13:35:50 2022
+++ src/sbin/fsck_udf/main.c	Wed Apr  6 13:35:50 2022
@@ -0,0 +1,4468 @@
+/*	$NetBSD: main.c,v 1.1 2022/04/06 13:35:50 reinoud Exp $	*/
+
+/*
+ * Copyright (c) 2022 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.
+ * 
+ */
+
+
+/*
+ * Note to reader:
+ *
+ * fsck_udf uses the common udf_core.c file with newfs and makefs. It does use
+ * some of the layout structure values but not all.
+ */
+
+
+#include <sys/cdefs.h>
+#ifndef lint
+__RCSID("$NetBSD: main.c,v 1.1 2022/04/06 13:35:50 reinoud Exp $");
+#endif /* not lint */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <dirent.h>
+#include <inttypes.h>
+#include <stdint.h>
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <util.h>
+#include <time.h>
+#include <tzfile.h>
+#include <math.h>
+#include <assert.h>
+#include <err.h>
+
+#if !HAVE_NBTOOL_CONFIG_H
+#define _EXPOSE_MMC
+#include <sys/cdio.h>
+#else
+#include "udf/cdio_mmc_structs.h"
+#endif
+
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/disklabel.h>
+#include <sys/dkio.h>
+#include <sys/param.h>
+#include <sys/queue.h>
+
+#include <fs/udf/ecma167-udf.h>
+#include <fs/udf/udf_mount.h>
+
+#include "fsutil.h"
+#include "exitvalues.h"
+#include "udf_core.h"
+
+/* Identifying myself */
+#define IMPL_NAME		"*NetBSD fsck_udf 10.0"
+#define APP_VERSION_MAIN	0
+#define APP_VERSION_SUB		5
+
+/* allocation walker actions */
+#define AD_LOAD_FILE		(1<<0)
+#define AD_SAVE_FILE		(1<<1)
+#define AD_CHECK_FIDS		(1<<2)
+#define AD_ADJUST_FIDS		(1<<3)
+#define AD_GATHER_STATS		(1<<4)
+#define AD_CHECK_USED		(1<<5)
+#define AD_MARK_AS_USED		(1<<6)
+#define AD_FIND_OVERLAP_PAIR	(1<<7)
+
+struct udf_fsck_file_stats {
+	uint64_t inf_len;
+	uint64_t obj_size;
+	uint64_t logblks_rec;
+};
+
+
+struct udf_fsck_fid_context {
+	uint64_t fid_offset;
+	uint64_t data_left;
+};
+
+
+/* basic node administration for passes */
+#define FSCK_NODE_FLAG_HARDLINK		(1<< 0)	/* hardlink, for accounting */
+#define FSCK_NODE_FLAG_DIRECTORY	(1<< 1)	/* is a normal directory */
+#define FSCK_NODE_FLAG_HAS_STREAM_DIR	(1<< 2)	/* has a stream directory */
+#define FSCK_NODE_FLAG_STREAM_ENTRY	(1<< 3)	/* is a stream file */
+#define FSCK_NODE_FLAG_STREAM_DIR	(1<< 4)	/* is a stream directory */
+#define FSCK_NODE_FLAG_OK(f)		(((f) >> 5) == 0)
+
+#define FSCK_NODE_FLAG_KEEP		(1<< 5)	/* don't discard */
+#define FSCK_NODE_FLAG_DIRTY		(1<< 6)	/* descriptor needs writeout */
+#define FSCK_NODE_FLAG_REPAIRDIR	(1<< 7)	/* repair bad FID entries */
+#define FSCK_NODE_FLAG_NEW_UNIQUE_ID	(1<< 8)	/* repair bad FID entries */
+#define FSCK_NODE_FLAG_COPY_PARENT_ID	(1<< 9)	/* repair bad FID entries */
+#define FSCK_NODE_FLAG_WIPE_STREAM_DIR	(1<<10)	/* wipe stream directory */
+#define FSCK_NODE_FLAG_NOTFOUND		(1<<11)	/* FID pointing to garbage */
+#define FSCK_NODE_FLAG_PAR_NOT_FOUND	(1<<12)	/* parent node not found! */
+#define FSCK_NODE_FLAG_OVERLAP		(1<<13) /* node has overlaps */
+
+#define FSCK_NODE_FLAG_STREAM (FSCK_NODE_FLAG_STREAM_ENTRY | FSCK_NODE_FLAG_STREAM_DIR)
+
+
+#define	HASH_HASHBITS	5
+#define	HASH_HASHSIZE	(1 << HASH_HASHBITS)
+#define	HASH_HASHMASK	(HASH_HASHSIZE - 1)
+
+/* fsck node for accounting checks */
+struct udf_fsck_node {
+	struct udf_fsck_node *parent;
+	char *fname;
+
+	struct long_ad	loc;
+	struct long_ad	streamdir_loc;
+	int		fsck_flags;
+
+	int		link_count;
+	int		found_link_count;
+	uint64_t	unique_id;
+
+	struct udf_fsck_file_stats declared;
+	struct udf_fsck_file_stats found;
+
+	uint8_t		*directory;		/* directory contents */
+
+	LIST_ENTRY(udf_fsck_node) next_hash;
+	TAILQ_ENTRY(udf_fsck_node) next;
+};
+TAILQ_HEAD(udf_fsck_node_list, udf_fsck_node) fs_nodes;
+LIST_HEAD(udf_fsck_node_hash_list, udf_fsck_node) fs_nodes_hash[HASH_HASHSIZE];
+
+
+/* fsck used space bitmap conflict list */
+#define FSCK_OVERLAP_MAIN_NODE	(1<<0)
+#define FSCK_OVERLAP_EXTALLOC	(1<<1)
+#define FSCK_OVERLAP_EXTENT	(1<<2)
+
+struct udf_fsck_overlap {
+	struct udf_fsck_node *node;
+	struct udf_fsck_node *node2;
+
+	struct long_ad	loc;
+	struct long_ad	loc2;
+
+	int		flags;
+	int		flags2;
+
+	TAILQ_ENTRY(udf_fsck_overlap) next;
+};
+TAILQ_HEAD(udf_fsck_overlap_list, udf_fsck_overlap) fsck_overlaps;
+
+
+/* backup of old read in free space bitmaps */
+struct space_bitmap_desc *recorded_part_unalloc_bits[UDF_PARTITIONS];
+uint32_t recorded_part_free[UDF_PARTITIONS];
+
+/* shadow VAT build */
+uint8_t *shadow_vat_contents;
+
+
+/* options */
+int alwaysno = 0;		/* assume "no" for all questions */
+int alwaysyes = 0;		/* assume "yes" for all questions */
+int search_older_vat = 0;	/* search for older VATs */
+int force = 0;			/* do check even if its marked clean */
+int preen = 0;			/* set when preening, doing automatic small repairs */
+int rdonly = 0;			/* open device/image read-only */
+int rdonly_flag = 0;		/* as passed on command line */
+int heuristics = 0;		/* use heuristics to fix esoteric corruptions */
+int target_session = 0;		/* offset to last session to check */
+
+
+/* actions to undertake */
+int undo_opening_session = 0;	/* trying to undo opening of last crippled session */
+int open_integrity = 0;		/* should be open the integrity ie close later */
+int vat_writeout = 0;		/* write out the VAT anyway */
+
+
+/* SIGINFO */
+static sig_atomic_t print_info = 0;		/* request for information on progress */
+
+
+/* prototypes */
+static void usage(void) __dead;
+static int checkfilesys(char *given_dev);
+static int ask(int def, const char *fmt, ...);
+static int ask_noauto(int def, const char *fmt, ...);
+
+static void udf_recursive_keep(struct udf_fsck_node *node);
+static char *udf_node_path(struct udf_fsck_node *node);
+static void udf_shadow_VAT_in_use(struct long_ad *loc);
+static int udf_quick_check_fids(struct udf_fsck_node *node, union dscrptr *dscr);
+
+
+/* --------------------------------------------------------------------- */
+
+/* from bin/ls */
+static void
+printtime(time_t ftime)
+{
+	struct timespec clock;
+        const char *longstring;
+	time_t now;
+        int i;
+
+	clock_gettime(CLOCK_REALTIME, &clock);
+	now = clock.tv_sec;
+
+        if ((longstring = ctime(&ftime)) == NULL) {
+                           /* 012345678901234567890123 */
+                longstring = "????????????????????????";
+        }
+        for (i = 4; i < 11; ++i)
+                (void)putchar(longstring[i]);
+
+#define SIXMONTHS       ((DAYSPERNYEAR / 2) * SECSPERDAY)
+        if (ftime + SIXMONTHS > now && ftime - SIXMONTHS < now)
+                for (i = 11; i < 16; ++i)
+                        (void)putchar(longstring[i]);
+        else {
+                (void)putchar(' ');
+                for (i = 20; i < 24; ++i)
+                        (void)putchar(longstring[i]);
+        }
+        (void)putchar(' ');
+}
+
+
+static void
+udf_print_timestamp(const char *prefix, struct timestamp *timestamp, const char *suffix)
+{
+	struct timespec timespec;
+
+	udf_timestamp_to_timespec(timestamp, &timespec);
+	printf("%s", prefix);
+	printtime(timespec.tv_sec);
+	printf("%s", suffix);
+}
+
+
+static int
+udf_compare_mtimes(struct timestamp *t1, struct timestamp *t2)
+{
+	struct timespec t1_tsp, t2_tsp;
+
+	udf_timestamp_to_timespec(t1, &t1_tsp);
+	udf_timestamp_to_timespec(t2, &t2_tsp);
+
+	if (t1_tsp.tv_sec  < t2_tsp.tv_sec)
+		return -1;
+	if (t1_tsp.tv_sec  > t2_tsp.tv_sec)
+		return  1;
+	if (t1_tsp.tv_nsec < t2_tsp.tv_nsec)
+		return -1;
+	if (t1_tsp.tv_nsec > t2_tsp.tv_nsec)
+		return  1;
+	return 0;
+}
+
+/* --------------------------------------------------------------------- */
+
+static int
+udf_calc_node_hash(struct long_ad *icb)
+{
+	uint32_t lb_num = udf_rw32(icb->loc.lb_num);
+	uint16_t vpart  = udf_rw16(icb->loc.part_num);
+
+	return ((uint64_t) (vpart + lb_num * 257)) & HASH_HASHMASK;
+}
+
+
+static struct udf_fsck_node *
+udf_node_lookup(struct long_ad *icb)
+{
+	struct udf_fsck_node *pos;
+	int entry = udf_calc_node_hash(icb);
+
+	pos = LIST_FIRST(&fs_nodes_hash[entry]);
+	while (pos) {
+		if (pos->loc.loc.part_num == icb->loc.part_num)
+			if (pos->loc.loc.lb_num == icb->loc.lb_num)
+				return pos;
+		pos = LIST_NEXT(pos, next_hash);
+	}
+	return NULL;
+}
+
+/* --------------------------------------------------------------------- */
+
+/* Note: only for VAT media since we don't allocate in bitmap */
+static void
+udf_wipe_and_reallocate(union dscrptr *dscrptr, int vpart_num, uint32_t *l_adp)
+{
+	struct file_entry    *fe  = &dscrptr->fe;
+	struct extfile_entry *efe = &dscrptr->efe;
+	struct desc_tag      *tag = &dscrptr->tag;
+	struct icb_tag       *icb;
+	struct long_ad        allocated;
+	struct long_ad       *long_adp  = NULL;
+	struct short_ad      *short_adp = NULL;
+	uint64_t inf_len;
+	uint32_t l_ea, l_ad;
+	uint8_t *bpos;
+	int bpos_start, ad_type, id;
+
+	assert(context.format_flags & FORMAT_VAT);
+
+	id = udf_rw16(tag->id);
+	assert(id == TAGID_FENTRY || id == TAGID_EXTFENTRY);
+	if (id == TAGID_FENTRY) {
+		icb         = &fe->icbtag;
+		inf_len     = udf_rw64(fe->inf_len);
+		l_ea        = udf_rw32(fe->l_ea);
+		bpos        = (uint8_t *) fe->data + l_ea;
+		bpos_start  = offsetof(struct file_entry, data) + l_ea;
+	} else {
+		icb         = &efe->icbtag;
+		inf_len     = udf_rw64(efe->inf_len);
+		l_ea        = udf_rw32(efe->l_ea);
+		bpos        = (uint8_t *) efe->data + l_ea;
+		bpos_start  = offsetof(struct extfile_entry, data) + l_ea;
+	}
+	/* inf_len should be correct for one slot */
+	assert(inf_len < UDF_EXT_MAXLEN);
+
+	ad_type = udf_rw16(icb->flags) & UDF_ICB_TAG_FLAGS_ALLOC_MASK;
+	if (ad_type == UDF_ICB_INTERN_ALLOC) {
+		/* no action needed */
+		return;
+	}
+
+	assert(vpart_num == context.data_part);
+	udf_data_alloc(udf_bytes_to_sectors(inf_len), &allocated);
+	memset(bpos, 0, context.sector_size - bpos_start);
+	/* create one short_ad or one long_ad */
+	if (ad_type == UDF_ICB_SHORT_ALLOC) {
+		short_adp = (struct short_ad *) bpos;
+		short_adp->len    = udf_rw64(inf_len);
+		short_adp->lb_num = allocated.loc.lb_num;
+		l_ad = sizeof(struct short_ad);
+	} else {
+		long_adp  = (struct long_ad  *) bpos;
+		memcpy(long_adp, &allocated, sizeof(struct long_ad));
+		long_adp->len = udf_rw64(inf_len);
+		l_ad = sizeof(struct long_ad);
+	}
+	if (id == TAGID_FENTRY)
+		fe->l_ad = udf_rw32(l_ad);
+	else
+		efe->l_ad = udf_rw32(l_ad);
+	;
+	*l_adp = l_ad;
+}
+
+
+static void
+udf_copy_fid_verbatim(struct fileid_desc *sfid, struct fileid_desc *dfid,
+		uint64_t dfpos, uint64_t drest)
+{
+	uint64_t endfid;
+	uint32_t minlen, lb_rest, fidsize;
+
+	if (udf_rw16(sfid->l_iu) == 0) {
+		memcpy(dfid, sfid, udf_fidsize(sfid));
+		return;
+	}
+
+	/* see if we can reduce its size */
+	minlen = udf_fidsize(sfid) - udf_rw16(sfid->l_iu);
+
+	/*
+	 * OK, tricky part: we need to pad so the next descriptor header won't
+	 * cross the sector boundary
+	 */
+	endfid = dfpos + minlen;
+	lb_rest = context.sector_size - (endfid % context.sector_size);
+
+	memcpy(dfid, sfid, UDF_FID_SIZE);
+	if (lb_rest < sizeof(struct desc_tag)) {
+		/* add at least 32 */
+		dfid->l_iu = udf_rw16(32);
+		udf_set_regid((struct regid *) dfid->data, context.impl_name);
+		udf_add_impl_regid((struct regid *) dfid->data);
+
+	}
+	memcpy( dfid->data + udf_rw16(dfid->l_iu),
+		sfid->data + udf_rw16(sfid->l_iu),
+		minlen - UDF_FID_SIZE);
+
+	fidsize = udf_fidsize(dfid);
+	dfid->tag.desc_crc_len = udf_rw16(fidsize - UDF_DESC_TAG_LENGTH);
+}
+
+
+static int
+udf_rebuild_fid_stream(struct udf_fsck_node *node, int64_t *rest_lenp)
+{
+	struct fileid_desc *sfid, *dfid;
+	uint64_t inf_len;
+	uint64_t sfpos, dfpos;
+	int64_t srest, drest;
+//	uint32_t sfid_len, dfid_len;
+	uint8_t *directory, *rebuild_dir;
+//	int namelen;
+	int error, streaming, was_streaming, warned, error_in_stream;
+
+	directory = node->directory;
+	inf_len   = node->found.inf_len;
+
+	rebuild_dir = calloc(1, inf_len);
+	assert(rebuild_dir);
+
+	sfpos  = 0;
+	srest  = inf_len;
+
+	dfpos  = 0;
+	drest  = inf_len;
+
+	error_in_stream = 0;
+	streaming = 1;
+	was_streaming = 1;
+	warned = 0;
+	while (srest > 0) {
+		if (was_streaming & !streaming) {
+			if (!warned) {
+				pwarn("%s : BROKEN directory\n",
+					udf_node_path(node));
+				udf_recursive_keep(node);
+				node->fsck_flags |= FSCK_NODE_FLAG_REPAIRDIR;
+			}
+			warned = 1;
+			pwarn("%s : <directory resync>\n",
+					udf_node_path(node));
+		}
+		was_streaming = streaming;
+
+		assert(drest >= UDF_FID_SIZE);
+		sfid = (struct fileid_desc *) (directory + sfpos);
+		dfid = (struct fileid_desc *) (rebuild_dir + dfpos);
+
+		/* check if we can read/salvage the next source fid */
+		if (udf_rw16(sfid->tag.id) != TAGID_FID) {
+			streaming = 0;
+			sfpos += 4;
+			srest -= 4;
+			error_in_stream = 1;
+			continue;
+		}
+		error = udf_check_tag(sfid);
+		if (error) {
+			/* unlikely to be recoverable */
+			streaming = 0;
+			sfpos += 4;
+			srest -= 4;
+			error_in_stream = 1;
+			continue;
+		}
+		error = udf_check_tag_payload(
+			(union dscrptr *) sfid,
+			context.sector_size);
+		if (!error) {
+			streaming = 1;
+			/* all OK, just copy verbatim, shrinking if possible */
+			udf_copy_fid_verbatim(sfid, dfid, dfpos, drest);
+
+			sfpos += udf_fidsize(sfid);
+			srest -= udf_fidsize(sfid);
+
+			dfpos += udf_fidsize(dfid);
+			drest -= udf_fidsize(dfid);
+
+			assert(udf_fidsize(sfid) == udf_fidsize(dfid));
+			continue;
+		}
+
+		/*
+		 * The hard part, we need to try to recover of what is
+		 * deductible of the bad source fid. The tag itself is OK, but
+		 * that doesn't say much; its contents can still be off.
+		 */
+
+		/* TODO NOT IMPLEMENTED YET, skip this entry the blunt way */
+		streaming = 0;
+		sfpos += 4;
+		srest -= 4;
+		error_in_stream = 1;
+	}
+
+	/* if we could shrink/fix the node, mark it for repair */
+	if (error_in_stream) {
+		udf_recursive_keep(node);
+		node->fsck_flags |= FSCK_NODE_FLAG_REPAIRDIR;
+	}
+
+	if (sfpos != dfpos)
+		printf("%s: could save %ld bytes in directory\n", udf_node_path(node), sfpos - dfpos);
+
+	memset(directory, 0, inf_len);
+	memcpy(directory, rebuild_dir, dfpos);
+
+	free(rebuild_dir);
+
+	*rest_lenp = dfpos;
+	return error_in_stream;
+}
+
+
+static int
+udf_quick_check_fids_piece(uint8_t *piece, uint32_t piece_len,
+		struct udf_fsck_fid_context *fid_context,
+		uint32_t lb_num)
+{
+	int error;
+	struct fileid_desc *fid;
+	uint32_t location;
+	uint32_t offset, fidsize;
+
+	offset = fid_context->fid_offset % context.sector_size;
+	while (fid_context->data_left && (offset < piece_len)) {
+		fid = (struct fileid_desc *) (piece + offset);
+		if (udf_rw16(fid->tag.id) == TAGID_FID) {
+			error = udf_check_tag_payload(
+					(union dscrptr *) fid,
+					context.sector_size);
+			if (error)
+				return error;
+		} else {
+			return EINVAL;
+		}
+		assert(udf_rw16(fid->tag.id) == TAGID_FID);
+
+		location = lb_num + offset / context.sector_size;
+
+		if (udf_rw32(fid->tag.tag_loc) != location)
+			return EINVAL;
+
+		if (context.dscrver == 2) {
+			/* compression IDs should be preserved in UDF < 2.00 */
+			if (*(fid->data + udf_rw16(fid->l_iu)) > 16)
+				return EINVAL;
+		}
+
+		fidsize      = udf_fidsize(fid);
+		offset      += fidsize;
+		fid_context->fid_offset += fidsize;
+		fid_context->data_left  -= fidsize;
+	}
+
+	return 0;
+}
+
+
+static void
+udf_fids_fixup(uint8_t *piece, uint32_t piece_len,
+		struct udf_fsck_fid_context *fid_context,
+		uint32_t lb_num)
+{
+	struct fileid_desc *fid;
+	uint32_t location;
+	uint32_t offset, fidsize;
+
+	offset = fid_context->fid_offset % context.sector_size;
+	while (fid_context->data_left && (offset < piece_len)) {
+
+		fid = (struct fileid_desc *) (piece + offset);
+		assert(udf_rw16(fid->tag.id) == TAGID_FID);
+
+		location = lb_num + offset / context.sector_size;
+		fid->tag.tag_loc = udf_rw32(location);
+
+		udf_validate_tag_and_crc_sums((union dscrptr *) fid);
+
+		fidsize      = udf_fidsize(fid);
+		offset      += fidsize;
+		fid_context->fid_offset += fidsize;
+		fid_context->data_left  -= fidsize;
+	}
+}
+
+
+/* NOTE returns non 0 for overlap, not an error code */
+static int
+udf_check_if_allocated(struct udf_fsck_node *node, int flags,
+		uint32_t start_lb, int partnr, uint32_t piece_len)
+{
+	union dscrptr *dscr;
+	struct udf_fsck_overlap *new_overlap;
+	uint8_t *bpos;
+	uint32_t cnt, bit;
+	uint32_t blocks = udf_bytes_to_sectors(piece_len);
+	int overlap = 0;
+
+	/* account for space used on underlying partition */
+#ifdef DEBUG
+	printf("check allocated : node %p, flags %d, partnr %d, start_lb %d for %d blocks\n",
+		node, flags, partnr, start_lb, blocks);
+#endif
+
+	switch (context.vtop_tp[partnr]) {
+	case UDF_VTOP_TYPE_VIRT:
+		/* nothing */
+		break;
+	case UDF_VTOP_TYPE_PHYS:
+	case UDF_VTOP_TYPE_SPAREABLE:
+	case UDF_VTOP_TYPE_META:
+		if (context.part_unalloc_bits[context.vtop[partnr]] == NULL)
+			break;
+#ifdef DEBUG
+		printf("checking allocation of %d+%d for being used\n", start_lb, blocks);
+#endif
+		dscr = (union dscrptr *) (context.part_unalloc_bits[partnr]);
+		for (cnt = start_lb; cnt < start_lb + blocks; cnt++) {
+			 bpos  = &dscr->sbd.data[cnt / 8];
+			 bit   = cnt % 8;
+			 /* only account for bits marked free */
+			 if ((*bpos & (1 << bit)) == 0)
+				 overlap++;
+		}
+		if (overlap == 0)
+			break;
+
+		/* overlap */
+//		pwarn("%s allocation OVERLAP found, type %d\n",
+//				udf_node_path(node), flags);
+		udf_recursive_keep(node);
+		node->fsck_flags |= FSCK_NODE_FLAG_OVERLAP;
+
+		new_overlap = calloc(1, sizeof(struct udf_fsck_overlap));
+		assert(new_overlap);
+
+		new_overlap->node              = node;
+		new_overlap->node2             = NULL;
+		new_overlap->flags             = flags;
+		new_overlap->flags2            = 0;
+		new_overlap->loc.len           = udf_rw32(piece_len);
+		new_overlap->loc.loc.lb_num    = udf_rw32(start_lb);
+		new_overlap->loc.loc.part_num  = udf_rw16(partnr);
+
+		TAILQ_INSERT_TAIL(&fsck_overlaps, new_overlap, next);
+
+		return overlap;
+		break;
+	default:
+		errx(1, "internal error: bad mapping type %d in %s",
+			context.vtop_tp[partnr], __func__);
+	}
+	/* no overlap */
+	return 0;
+}
+
+
+/* NOTE returns non 0 for overlap, not an error code */
+static void
+udf_check_overlap_pair(struct udf_fsck_node *node, int flags,
+		uint32_t start_lb, int partnr, uint32_t piece_len)
+{
+	struct udf_fsck_overlap *overlap;
+	uint32_t ostart_lb, opiece_len, oblocks;
+	uint32_t blocks = udf_bytes_to_sectors(piece_len);
+	int opartnr;
+
+	/* account for space used on underlying partition */
+#ifdef DEBUG
+	printf("check overlap pair : node %p, flags %d, partnr %d, start_lb %d for %d blocks\n",
+		node, flags, partnr, start_lb, blocks);
+#endif
+
+	switch (context.vtop_tp[partnr]) {
+	case UDF_VTOP_TYPE_VIRT:
+		/* nothing */
+		break;
+	case UDF_VTOP_TYPE_PHYS:
+	case UDF_VTOP_TYPE_SPAREABLE:
+	case UDF_VTOP_TYPE_META:
+		if (context.part_unalloc_bits[context.vtop[partnr]] == NULL)
+			break;
+#ifdef DEBUG
+		printf("checking overlap of %d+%d for being used\n", start_lb, blocks);
+#endif
+		/* check all current overlaps with the piece we have here */
+		TAILQ_FOREACH(overlap, &fsck_overlaps, next) {
+			opiece_len = udf_rw32(overlap->loc.len);
+			ostart_lb  = udf_rw32(overlap->loc.loc.lb_num);
+			opartnr    = udf_rw16(overlap->loc.loc.part_num);
+			oblocks    = udf_bytes_to_sectors(opiece_len);
+
+			if (partnr != opartnr)
+				continue;
+			/* piece before overlap? */
+			if (start_lb + blocks < ostart_lb)
+				continue;
+			/* piece after overlap? */
+			if (start_lb > ostart_lb + oblocks)
+				continue;
+
+			/* overlap, mark conflict */
+			overlap->node2             = node;
+			overlap->flags2            = flags;
+			overlap->loc2.len          = udf_rw32(piece_len);
+			overlap->loc2.loc.lb_num   = udf_rw32(start_lb);
+			overlap->loc2.loc.part_num = udf_rw16(partnr);
+
+			udf_recursive_keep(node);
+			node->fsck_flags |= FSCK_NODE_FLAG_OVERLAP;
+		}
+		return;
+	default:
+		errx(1, "internal error: bad mapping type %d in %s",
+			context.vtop_tp[partnr], __func__);
+	}
+	/* no overlap */
+	return;
+}
+
+
+
+static int
+udf_process_ad(union dscrptr *dscrptr, int action, uint8_t **resultp,
+	int vpart_num, uint64_t fpos,
+	struct short_ad *short_adp, struct long_ad *long_adp, void *process_context)
+{
+	struct file_entry    *fe  = &dscrptr->fe;
+	struct extfile_entry *efe = &dscrptr->efe;
+	struct desc_tag      *tag = &dscrptr->tag;
+	struct icb_tag  *icb;
+	struct udf_fsck_file_stats *stats;
+	uint64_t inf_len;
+	uint32_t l_ea, piece_len, piece_alloc_len, piece_sectors, lb_num, flags;
+	uint32_t dscr_lb_num;
+	uint32_t i;
+	uint8_t *bpos, *piece;
+	int id, ad_type;
+	int error, piece_error, return_error;
+
+	assert(dscrptr);
+	stats = (struct udf_fsck_file_stats *) process_context;
+
+	id = udf_rw16(tag->id);
+	assert(id == TAGID_FENTRY || id == TAGID_EXTFENTRY);
+	if (id == TAGID_FENTRY) {
+		icb         = &fe->icbtag;
+		dscr_lb_num = udf_rw32(fe->tag.tag_loc);
+		inf_len     = udf_rw64(fe->inf_len);
+		l_ea        = udf_rw32(fe->l_ea);
+		bpos        = (uint8_t *) fe->data + l_ea;
+	} else {
+		icb         = &efe->icbtag;
+		dscr_lb_num = udf_rw32(efe->tag.tag_loc);
+		inf_len     = udf_rw64(efe->inf_len);
+		l_ea        = udf_rw32(efe->l_ea);
+		bpos        = (uint8_t *) efe->data + l_ea;
+	}
+
+	lb_num = 0;
+	piece_len = 0;
+
+	ad_type = udf_rw16(icb->flags) & UDF_ICB_TAG_FLAGS_ALLOC_MASK;
+	if (ad_type == UDF_ICB_INTERN_ALLOC) {
+		piece_len = inf_len;
+	}
+	if (short_adp) {
+		piece_len = udf_rw32(short_adp->len);
+		lb_num    = udf_rw32(short_adp->lb_num);
+	}
+	if (long_adp) {
+		piece_len = udf_rw32(long_adp->len);
+		lb_num    = udf_rw32(long_adp->loc.lb_num);
+		vpart_num = udf_rw16(long_adp->loc.part_num);
+	}
+	flags = UDF_EXT_FLAGS(piece_len);
+	piece_len = UDF_EXT_LEN(piece_len);
+	piece_alloc_len = UDF_ROUNDUP(piece_len, context.sector_size);
+	piece_sectors   = piece_alloc_len / context.sector_size;
+
+	return_error = 0;
+	if (action & AD_GATHER_STATS) {
+		if (ad_type == UDF_ICB_INTERN_ALLOC) {
+			stats->inf_len     = piece_len;
+			stats->obj_size    = piece_len;
+			stats->logblks_rec = 0;
+		}  else if (flags == UDF_EXT_ALLOCATED) {
+			stats->inf_len     += piece_len;
+			stats->obj_size    += piece_len;
+			stats->logblks_rec += piece_sectors;
+		} else if (flags == UDF_EXT_FREED) {
+			stats->inf_len     += piece_len;
+			stats->obj_size    += piece_len;
+			stats->logblks_rec += piece_sectors;
+		} else if (flags == UDF_EXT_FREE) {
+			stats->inf_len     += piece_len;
+			stats->obj_size    += piece_len;
+		}
+	}
+	if (action & AD_LOAD_FILE) {
+		uint32_t alloc_len;
+
+		piece = calloc(1, piece_alloc_len);
+		if (piece == NULL)
+			return errno;
+		if (ad_type == UDF_ICB_INTERN_ALLOC) {
+			memcpy(piece, bpos, piece_len);
+		} else if (flags == 0) {
+			/* not empty */
+			/* read sector by sector reading as much as possible */
+			for (i = 0; i < piece_sectors; i++) {
+				piece_error = udf_read_virt(
+					piece + i * context.sector_size,
+					lb_num + i, vpart_num, 1);
+				if (piece_error)
+					return_error = piece_error;
+			}
+		}
+
+		alloc_len = UDF_ROUNDUP(fpos + piece_len, context.sector_size);
+		error = reallocarr(resultp, 1, alloc_len);
+		if (error) {
+			/* fatal */
+			free(piece);
+			free(*resultp);
+			return errno;
+		}
+
+		memcpy(*resultp + fpos, piece, piece_alloc_len);
+		free(piece);
+	}
+	if (action & AD_ADJUST_FIDS) {
+		piece = *resultp + fpos;
+		if (ad_type == UDF_ICB_INTERN_ALLOC) {
+			udf_fids_fixup(piece, piece_len, process_context,
+				dscr_lb_num);
+		} else if (flags == 0) {
+			udf_fids_fixup(piece, piece_len, process_context,
+				lb_num);
+		}
+	}
+	if (action & AD_CHECK_FIDS) {
+		piece = *resultp + fpos;
+		if (ad_type == UDF_ICB_INTERN_ALLOC) {
+			error = udf_quick_check_fids_piece(piece, piece_len,
+				process_context, dscr_lb_num);
+		} else if (flags == 0) {
+			error = udf_quick_check_fids_piece(piece, piece_len,
+				process_context, lb_num);
+		}
+		if (error)
+			return error;
+	}
+	if (action & AD_SAVE_FILE) {
+		/*
+		 * Note: only used for directory contents.
+		 */
+		piece = *resultp + fpos;
+		if (ad_type == UDF_ICB_INTERN_ALLOC) {
+			memcpy(bpos, piece, piece_len);
+			/* nothing */
+		} else if (flags == 0) {
+			/* not empty */
+			error = udf_write_virt(
+				piece, lb_num, vpart_num,
+				piece_sectors);
+			if (error) {
+				pwarn("Got error writing piece\n");
+				return error;
+			}
+		} else {
+			/* allocated but not written piece, skip */
+		}
+	}
+	if (action & AD_CHECK_USED) {
+		if (ad_type == UDF_ICB_INTERN_ALLOC) {
+			/* nothing */
+		} else if (flags != UDF_EXT_FREE) {
+			struct udf_fsck_node *node = process_context;
+			(void) udf_check_if_allocated(
+				node,
+				FSCK_OVERLAP_EXTENT,
+				lb_num, vpart_num,
+				piece_len);
+		}
+	}
+	if (action & AD_FIND_OVERLAP_PAIR) {
+		if (ad_type == UDF_ICB_INTERN_ALLOC) {
+			/* nothing */
+		} else if (flags != UDF_EXT_FREE) {
+			struct udf_fsck_node *node = process_context;
+			udf_check_overlap_pair(
+				node,
+				FSCK_OVERLAP_EXTENT,
+				lb_num, vpart_num,
+				piece_len);
+		}
+	}
+	if (action & AD_MARK_AS_USED) {
+		if (ad_type == UDF_ICB_INTERN_ALLOC) {
+			/* nothing */
+		} else if (flags != UDF_EXT_FREE) {
+			udf_mark_allocated(lb_num, vpart_num,
+				udf_bytes_to_sectors(piece_len));
+		}
+	}
+
+	return return_error;
+}
+
+
+static int
+udf_process_file(union dscrptr *dscrptr, int vpart_num, uint8_t **resultp,
+	int action, void *process_context)
+{
+	struct file_entry    *fe  = &dscrptr->fe;
+	struct extfile_entry *efe = &dscrptr->efe;
+	struct desc_tag      *tag = &dscrptr->tag;
+	struct alloc_ext_entry *ext;
+	struct icb_tag  *icb;
+	struct long_ad  *long_adp  = NULL;
+	struct short_ad *short_adp = NULL;
+	union  dscrptr *extdscr = NULL;
+	uint64_t fpos;
+	uint32_t l_ad, l_ea, piece_len, lb_num, flags;
+	uint8_t *bpos;
+	int id, extid, ad_type, ad_len;
+	int error;
+
+	id = udf_rw16(tag->id);
+	assert(id == TAGID_FENTRY || id == TAGID_EXTFENTRY);
+
+	if (action & AD_CHECK_USED) {
+		struct udf_fsck_node *node = process_context;
+		(void) udf_check_if_allocated(
+			node,
+			FSCK_OVERLAP_MAIN_NODE,
+			udf_rw32(node->loc.loc.lb_num),
+			udf_rw16(node->loc.loc.part_num),
+			context.sector_size);
+		/* return error code? */
+	}
+
+	if (action & AD_FIND_OVERLAP_PAIR) {
+		struct udf_fsck_node *node = process_context;
+		udf_check_overlap_pair(
+			node,
+			FSCK_OVERLAP_MAIN_NODE,
+			udf_rw32(node->loc.loc.lb_num),
+			udf_rw16(node->loc.loc.part_num),
+			context.sector_size);
+		/* return error code? */
+	}
+
+	if (action & AD_MARK_AS_USED)
+		udf_mark_allocated(udf_rw32(tag->tag_loc), vpart_num, 1);
+
+	if (id == TAGID_FENTRY) {
+		icb         = &fe->icbtag;
+		l_ad   = udf_rw32(fe->l_ad);
+		l_ea   = udf_rw32(fe->l_ea);
+		bpos = (uint8_t *) fe->data + l_ea;
+	} else {
+		icb         = &efe->icbtag;
+		l_ad   = udf_rw32(efe->l_ad);
+		l_ea   = udf_rw32(efe->l_ea);
+		bpos = (uint8_t *) efe->data + l_ea;
+	}
+
+	ad_type = udf_rw16(icb->flags) & UDF_ICB_TAG_FLAGS_ALLOC_MASK;
+	if (ad_type == UDF_ICB_INTERN_ALLOC) {
+		error = udf_process_ad(dscrptr, action, resultp, -1, 0,
+				NULL, NULL, process_context);
+		return error;
+	}
+	if ((ad_type != UDF_ICB_SHORT_ALLOC) &&
+			(ad_type != UDF_ICB_LONG_ALLOC))
+		return EINVAL;
+
+	if (ad_type == UDF_ICB_SHORT_ALLOC)
+		short_adp = (struct short_ad *) bpos;
+	else
+		long_adp  = (struct long_ad  *) bpos;
+	;
+
+	if (action & AD_SAVE_FILE) {
+		/*
+		 * Special case for writeout file/directory on recordable
+		 * media. We write in one go so wipe and (re)allocate the
+		 * entire space.
+		 */
+		if (context.format_flags & FORMAT_VAT)
+			udf_wipe_and_reallocate(dscrptr, vpart_num, &l_ad);
+	}
+
+	fpos = 0;
+	bpos = NULL;
+	error = 0;
+	while (l_ad) {
+		if (ad_type == UDF_ICB_SHORT_ALLOC) {
+			piece_len = udf_rw32(short_adp->len);
+			lb_num    = udf_rw32(short_adp->lb_num);
+			ad_len = sizeof(struct short_ad);
+		} else /* UDF_ICB_LONG_ALLOC  */ {
+			piece_len = udf_rw32(long_adp->len);
+			lb_num    = udf_rw32(long_adp->loc.lb_num);
+			vpart_num = udf_rw16(long_adp->loc.part_num);
+			ad_len = sizeof(struct long_ad);
+		}
+		flags = UDF_EXT_FLAGS(piece_len);
+		piece_len = UDF_EXT_LEN(piece_len);
+
+		switch (flags) {
+		default :
+			error = udf_process_ad(dscrptr, action, resultp,
+					vpart_num, fpos, short_adp, long_adp,
+					process_context);
+			break;
+		case UDF_EXT_REDIRECT  :
+			if (piece_len != context.sector_size) {
+				/* should this be an error? */
+				pwarn("Got extention redirect with wrong size %d\n",
+					piece_len);
+				error = EINVAL;
+				break;
+			}
+			free(extdscr);
+			error = udf_read_dscr_virt(lb_num, vpart_num, &extdscr);
+			if (error)
+				break;
+			/* empty block is terminator */
+			if (extdscr == NULL)
+				return 0;
+			ext = &extdscr->aee;
+			extid = udf_rw16(ext->tag.id);
+			if (extid != TAGID_ALLOCEXTENT) {
+				pwarn("Corruption in allocated extents chain\n");
+				/* corruption! */
+				free(extdscr);
+				errno = EINVAL;
+				break;
+			}
+
+			if (action & AD_CHECK_USED) {
+				(void) udf_check_if_allocated(
+					(struct udf_fsck_node *) process_context,
+					FSCK_OVERLAP_EXTALLOC,
+					lb_num,
+					vpart_num,
+					context.sector_size);
+				/* returning error code ? */
+			}
+
+			if (action & AD_FIND_OVERLAP_PAIR) {
+				struct udf_fsck_node *node = process_context;
+				udf_check_overlap_pair(
+					node,
+					FSCK_OVERLAP_EXTALLOC,
+					lb_num,
+					vpart_num,
+					context.sector_size);
+				/* return error code? */
+			}
+
+			if (action & AD_MARK_AS_USED)
+				udf_mark_allocated(
+					lb_num, vpart_num,
+					1);
+			/* TODO check for prev_entry? */
+			l_ad = ext->l_ad;
+			bpos = ext->data;
+			if (ad_type == UDF_ICB_SHORT_ALLOC)
+				short_adp = (struct short_ad *) bpos;
+			else
+				long_adp  = (struct long_ad  *) bpos;
+			;
+			continue;
+		}
+		if (error)
+			break;
+
+		if (long_adp)  long_adp++;
+		if (short_adp) short_adp++;
+		fpos += piece_len;
+		bpos += piece_len;
+		l_ad -= ad_len;
+	}
+
+	return error;
+}
+
+
+static int
+udf_readin_file(union dscrptr *dscrptr, int vpart_num, uint8_t **resultp,
+		struct udf_fsck_file_stats *statsp)
+{
+	struct udf_fsck_file_stats stats;
+	int error;
+
+	bzero(&stats, sizeof(stats));
+	*resultp = NULL;
+	error = udf_process_file(dscrptr, vpart_num, resultp,
+			AD_LOAD_FILE | AD_GATHER_STATS, (void *) &stats);
+	if (statsp)
+		*statsp = stats;
+	return error;
+}
+
+/* --------------------------------------------------------------------- */
+
+#define MAX_BSIZE		(0x10000)
+#define UDF_ISO_VRS_SIZE	(32*2048) /* 32 ISO `sectors' */
+
+static void
+udf_check_vrs9660(void)
+{
+	struct vrs_desc *vrs;
+	uint8_t buffer[MAX_BSIZE];
+	uint64_t rpos;
+	uint8_t *pos;
+	int max_sectors, sector, factor;
+	int ret, ok;
+
+	if (context.format_flags & FORMAT_TRACK512)
+		return;
+
+	/*
+	 * location of iso9660 VRS is defined as first sector AFTER 32kb,
+	 * minimum `sector size' 2048
+	 */
+	layout.iso9660_vrs = ((32*1024 + context.sector_size - 1) /
+			context.sector_size);
+	max_sectors = UDF_ISO_VRS_SIZE / 2048;
+	factor = (2048 + context.sector_size -1) / context.sector_size;
+
+	ok = 1;
+	rpos = (uint64_t) layout.iso9660_vrs * context.sector_size;
+	ret = pread(dev_fd, buffer, UDF_ISO_VRS_SIZE, rpos);
+	if (ret == -1) {
+		pwarn("Error reading in ISO9660 VRS\n");
+		ok = 0;
+	}
+	if (ok && ((uint32_t) ret != UDF_ISO_VRS_SIZE)) {
+		pwarn("Short read in ISO9660 VRS\n");
+		ok = 0;
+	}
+
+	if (ok) {
+		ok = 0;
+		for (sector = 0; sector < max_sectors; sector++) {
+			pos = buffer + sector * factor * context.sector_size;
+			vrs = (struct vrs_desc *) pos;
+			if (strncmp((const char *) vrs->identifier, VRS_BEA01, 5) == 0)
+				ok  = 1;
+			if (strncmp((const char *) vrs->identifier, VRS_NSR02, 5) == 0)
+				ok |= 2;
+			if (strncmp((const char *) vrs->identifier, VRS_NSR03, 5) == 0)
+				ok |= 2;
+			if (strncmp((const char *) vrs->identifier, VRS_TEA01, 5) == 0) {
+				ok |= 4;
+				break;
+			}
+		}
+		if (ok != 7)
+			ok = 0;
+	}
+	if (!ok) {
+		pwarn("Error in ISO 9660 volume recognition sequence\n");
+		if (context.format_flags & FORMAT_SEQUENTIAL) {
+			pwarn("ISO 9660 volume recognition sequence can't be repaired "
+			       "on SEQUENTIAL media\n");
+		} else if (ask(0, "fix ISO 9660 volume recognition sequence")) {
+			if (!rdonly)
+				udf_write_iso9660_vrs();
+		}
+	}
+}
+
+
+/*
+ * Read in disc and try to find basic properties like sector size, expected
+ * UDF versions etc.
+ */
+
+static int
+udf_find_anchor(int anum)
+{
+	uint8_t buffer[MAX_BSIZE];
+	struct anchor_vdp *avdp = (struct anchor_vdp *) buffer;
+	uint64_t rpos;
+	uint32_t location;
+	int sz_guess, ret;
+	int error;
+
+	location = layout.anchors[anum];
+
+	/*
+	 * Search ADVP by reading bigger and bigger sectors NOTE we can't use
+	 * udf_read_phys yet since the sector size is not known yet
+	 */
+	sz_guess = mmc_discinfo.sector_size;	/* assume media is bigger */
+	for (; sz_guess <= MAX_BSIZE; sz_guess += 512) {
+		rpos = (uint64_t) location * sz_guess;
+		ret = pread(dev_fd, buffer, sz_guess, rpos);
+		if (ret == -1) {
+			if (errno == ENODEV)
+				return errno;
+		} else if (ret != sz_guess) {
+			/* most likely EOF, ignore */
+		} else {
+			error = udf_check_tag_and_location(buffer, location);
+			if (!error) {
+				if (udf_rw16(avdp->tag.id) != TAGID_ANCHOR)
+					continue;
+				error = udf_check_tag_payload(buffer, sz_guess);
+				if (!error)
+					break;
+			}
+		}
+	}
+	if (sz_guess > MAX_BSIZE)
+		return -1;
+
+	/* special case for disc images */
+	if (mmc_discinfo.sector_size != (unsigned int) sz_guess) {
+		emul_sectorsize = sz_guess;
+		udf_update_discinfo();
+	}
+	context.sector_size = sz_guess;
+	context.dscrver = udf_rw16(avdp->tag.descriptor_ver);
+
+	context.anchors[anum] = calloc(1, context.sector_size);
+	memcpy(context.anchors[anum], avdp, context.sector_size);
+
+	context.min_udf = 0x102;
+	context.max_udf = 0x150;
+	if (context.dscrver > 2) {
+		context.min_udf = 0x200;
+		context.max_udf = 0x260;
+	}
+	return 0;
+}
+
+
+static int
+udf_get_anchors(void)
+{
+	struct mmc_trackinfo ti;
+	struct anchor_vdp *avdp;
+	int need_fixup, error;
+
+	memset(&layout, 0, sizeof(layout));
+	memset(&ti, 0, sizeof(ti));
+
+	/* search start */
+	for (int i = 1; i <= mmc_discinfo.num_tracks; i++) {
+		ti.tracknr = i;
+		error = udf_update_trackinfo(&ti);
+		assert(!error);
+		if (ti.sessionnr == target_session)
+			break;
+	}
+	/* support for track 512 */
+	if (ti.flags & MMC_TRACKINFO_BLANK) 
+		context.format_flags |= FORMAT_TRACK512;
+
+	assert(!error);
+	context.first_ti = ti;
+
+	/* search end */
+	for (int i = mmc_discinfo.num_tracks; i > 0; i--) {
+		ti.tracknr = i;
+		error = udf_update_trackinfo(&ti);
+		assert(!error);
+		if (ti.sessionnr == target_session)
+			break;
+	}
+	context.last_ti = ti;
+
+	layout.first_lba  = context.first_ti.track_start;
+	layout.last_lba   = mmc_discinfo.last_possible_lba;
+	layout.blockingnr = udf_get_blockingnr(&ti);
+
+	layout.anchors[0] = layout.first_lba + 256;
+	if (context.format_flags & FORMAT_TRACK512)
+		layout.anchors[0] = layout.first_lba + 512;
+	layout.anchors[1] = layout.last_lba - 256;
+	layout.anchors[2] = layout.last_lba;
+
+	need_fixup = 0;
+	error = udf_find_anchor(0);
+	if (error == ENODEV) {
+		pwarn("Drive empty?\n");
+		return errno;
+	}
+	if (error) {
+		need_fixup = 1;
+		if (!preen)
+			pwarn("Anchor ADVP0 can't be found! Searching others\n");
+		error = udf_find_anchor(2);
+		if (error) {
+			if (!preen)
+				pwarn("Anchor ADVP2 can't be found! Searching ADVP1\n");
+			/* this may be fidly, but search */
+			error = udf_find_anchor(1);
+			if (error) {
+				if (!preen)
+					pwarn("No valid anchors found!\n");
+				/* TODO scan media for VDS? */
+				return -1;
+			}
+		}
+	}
+
+	if (need_fixup) {
+		if (context.format_flags & FORMAT_SEQUENTIAL) {
+			pwarn("Missing primary anchor can't be resolved on "
+			      "SEQUENTIAL media\n");
+		} else if (ask(1, "Fixup missing anchors")) {
+			pwarn("TODO fixup missing anchors\n");
+			need_fixup = 0;
+		}
+		if (need_fixup)
+			return -1;
+	}
+	if (!preen)
+		printf("Filesystem sectorsize is %d bytes.\n\n",
+			context.sector_size);
+
+	/* update our last track info since our idea of sector size might have changed */
+	(void) udf_update_trackinfo(&context.last_ti);
+
+	/* sector size is now known */
+	wrtrack_skew = context.last_ti.next_writable % layout.blockingnr;
+
+	avdp = context.anchors[0];
+	/* extract info from current anchor */
+	layout.vds1      = udf_rw32(avdp->main_vds_ex.loc);
+	layout.vds1_size = udf_rw32(avdp->main_vds_ex.len) / context.sector_size;
+	layout.vds2      = udf_rw32(avdp->reserve_vds_ex.loc);
+	layout.vds2_size = udf_rw32(avdp->reserve_vds_ex.len) / context.sector_size;
+
+	return 0;
+}
+
+
+#define UDF_LVINT_HIST_CHUNK 32
+static void
+udf_retrieve_lvint(void) {
+	union dscrptr *dscr;
+	struct logvol_int_desc *lvint;
+	struct udf_lvintq *trace;
+	uint32_t lbnum, len, *pos;
+	uint8_t *wpos;
+	int num_partmappings;
+	int error, cnt, trace_len;
+	int sector_size = context.sector_size;
+
+	len     = udf_rw32(context.logical_vol->integrity_seq_loc.len);
+	lbnum   = udf_rw32(context.logical_vol->integrity_seq_loc.loc);
+	layout.lvis = lbnum;
+	layout.lvis_size = len / sector_size;
+
+	udf_create_lvintd(UDF_INTEGRITY_OPEN);
+
+	/* clean trace and history */
+	memset(context.lvint_trace, 0,
+	    UDF_LVDINT_SEGMENTS * sizeof(struct udf_lvintq));
+	context.lvint_history_wpos = 0;
+	context.lvint_history_len = UDF_LVINT_HIST_CHUNK;
+	context.lvint_history = calloc(UDF_LVINT_HIST_CHUNK, sector_size);
+
+	/* record the length on this segment */
+	context.lvint_history_ondisc_len = (len / sector_size);
+
+	trace_len    = 0;
+	trace        = context.lvint_trace;
+	trace->start = lbnum;
+	trace->end   = lbnum + len/sector_size;
+	trace->pos   = 0;
+	trace->wpos  = 0;
+
+	dscr  = NULL;
+	error = 0;
+	while (len) {
+		trace->pos  = lbnum - trace->start;
+		trace->wpos = trace->pos + 1;
+
+		free(dscr);
+		error = udf_read_dscr_phys(lbnum, &dscr);
+		/* bad descriptors mean corruption, terminate */
+		if (error)
+			break;
+
+		/* empty terminates */
+		if (dscr == NULL) {
+			trace->wpos = trace->pos;
+			break;
+		}
+
+		/* we got a valid descriptor */
+		if (udf_rw16(dscr->tag.id) == TAGID_TERM) {
+			trace->wpos = trace->pos;
+			break;
+		}
+		/* only logical volume integrity descriptors are valid */
+		if (udf_rw16(dscr->tag.id) != TAGID_LOGVOL_INTEGRITY) {
+			error = ENOENT;
+			break;
+		}
+		lvint = &dscr->lvid;
+
+		/* see if our history is long enough, with one spare */
+		if (context.lvint_history_wpos+2 >= context.lvint_history_len) {
+			int new_len = context.lvint_history_len +
+				UDF_LVINT_HIST_CHUNK;
+			if (reallocarr(&context.lvint_history,
+					new_len, sector_size))
+				err(FSCK_EXIT_CHECK_FAILED, "can't expand logvol history");
+			context.lvint_history_len = new_len;
+		}
+
+		/* are we linking to a new piece? */
+		if (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... */
+				pwarn("implementation limit: logical volume "
+					"integrity segment list full\n");
+				error = ENOMEM;
+				break;
+			}
+			trace++;
+			trace_len++;
+
+			trace->start = lbnum;
+			trace->end   = lbnum + len/sector_size;
+			trace->pos   = 0;
+			trace->wpos  = 0;
+
+			context.lvint_history_ondisc_len += (len / sector_size);
+		}
+
+		/* record this found lvint; it is one sector long */
+		wpos = context.lvint_history +
+			context.lvint_history_wpos * sector_size;
+		memcpy(wpos, dscr, sector_size);
+		memcpy(context.logvol_integrity, dscr, sector_size);
+		context.lvint_history_wpos++;
+
+		/* proceed sequential */
+		lbnum += 1;
+		len   -= sector_size;
+	}
+
+	/* clean up the mess, esp. when there is an error */
+	free(dscr);
+
+	if (error) {
+		if (!preen)
+			printf("Error in logical volume integrity sequence\n");
+		printf("Marking logical volume integrity OPEN\n");
+		udf_update_lvintd(UDF_INTEGRITY_OPEN);
+	}
+
+	if (udf_rw16(context.logvol_info->min_udf_readver) > context.min_udf)
+		context.min_udf   = udf_rw16(context.logvol_info->min_udf_readver);
+	if (udf_rw16(context.logvol_info->min_udf_writever) > context.min_udf)
+		context.min_udf   = udf_rw16(context.logvol_info->min_udf_writever);
+	if (udf_rw16(context.logvol_info->max_udf_writever) < context.max_udf)
+		context.max_udf   = udf_rw16(context.logvol_info->max_udf_writever);
+
+	context.unique_id = udf_rw64(context.logvol_integrity->lvint_next_unique_id);
+
+	/* fill in current size/free values */
+	pos = &context.logvol_integrity->tables[0];
+	num_partmappings = udf_rw32(context.logical_vol->n_pm);
+	for (cnt = 0; cnt < num_partmappings; cnt++) {
+		context.part_free[cnt] = udf_rw32(*pos);
+		pos++;
+	}
+	/* leave the partition sizes alone; no idea why they are stated here */
+	/* TODO sanity check the free space and partition sizes? */
+
+/* XXX FAULT INJECTION POINT XXX */
+//udf_update_lvintd(UDF_INTEGRITY_OPEN);
+
+	if (!preen) {
+		int ver;
+
+		printf("\n");
+		ver = udf_rw16(context.logvol_info->min_udf_readver);
+		printf("Minimum read  version v%x.%02x\n", ver/0x100, ver&0xff);
+		ver = udf_rw16(context.logvol_info->min_udf_writever);
+		printf("Minimum write version v%x.%02x\n", ver/0x100, ver&0xff);
+		ver = udf_rw16(context.logvol_info->max_udf_writever);
+		printf("Maximum write version v%x.%02x\n", ver/0x100, ver&0xff);
+
+		printf("\nLast logical volume integrity state is %s.\n",
+			udf_rw32(context.logvol_integrity->integrity_type) ?
+			"CLOSED" : "OPEN");
+	}
+}
+
+
+static int
+udf_writeout_lvint(void)
+{
+	union dscrptr *terminator;
+	struct udf_lvintq *intq, *nintq;
+	struct logvol_int_desc *lvint;
+	uint32_t location;
+	int wpos, num_avail;
+	int sector_size = context.sector_size;
+	int integrity_type, error;
+	int next_present, end_slot, last_segment;
+
+	/* only write out when its open */
+	integrity_type = udf_rw32(context.logvol_integrity->integrity_type);
+	if (integrity_type == UDF_INTEGRITY_CLOSED)
+		return 0;
+
+	if (!preen)
+		printf("\n");
+	if (!ask(1, "Write out modifications"))
+		return 0;
+
+	udf_allow_writing();
+
+	/* close logical volume */
+	udf_update_lvintd(UDF_INTEGRITY_CLOSED);
+
+	/* do we need to lose some history? */
+	if ((context.lvint_history_ondisc_len - context.lvint_history_wpos) < 2) {
+		uint8_t *src, *dst;
+		uint32_t size;
+
+		dst = context.lvint_history;
+		src = dst + sector_size;
+		size = (context.lvint_history_wpos-2) * sector_size;
+		memmove(dst, src, size);
+		context.lvint_history_wpos -= 2;
+	}
+
+	/* write out complete trace just in case */
+	wpos = 0;
+	location = 0;
+	for (int i = 0; i < UDF_LVDINT_SEGMENTS; i++) {
+		intq = &context.lvint_trace[i];
+		nintq = &context.lvint_trace[i+1];
+
+		/* end of line? */
+		if (intq->start == intq->end)
+			break;
+		num_avail = intq->end - intq->start;
+		location  = intq->start;
+		for (int sector = 0; sector < num_avail; sector++) {
+			lvint = (struct logvol_int_desc *)
+				(context.lvint_history + wpos * sector_size);
+			memset(&lvint->next_extent, 0, sizeof(struct extent_ad));
+			next_present = (wpos != context.lvint_history_wpos);
+			end_slot     = (sector == num_avail -1);
+			last_segment = (i == UDF_LVDINT_SEGMENTS-1);
+			if (end_slot && next_present && !last_segment) {
+				/* link to next segment */
+				lvint->next_extent.len = udf_rw32(
+					sector_size * (nintq->end - nintq->start));
+				lvint->next_extent.loc = udf_rw32(nintq->start);
+			}
+			error = udf_write_dscr_phys((union dscrptr *) lvint, location, 1);
+			assert(!error);
+			wpos++;
+			location++;
+			if (wpos == context.lvint_history_wpos)
+				break;
+		}
+	}
+
+	/* at write pos, write out our integrity */
+	assert(location);
+	lvint = context.logvol_integrity;
+	error = udf_write_dscr_phys((union dscrptr *) lvint, location, 1);
+	assert(!error);
+	wpos++;
+	location++;
+
+	/* write out terminator */
+	terminator = calloc(1, context.sector_size);
+	assert(terminator);
+	udf_create_terminator(terminator, 0);
+
+	/* same or increasing serial number: ECMA 3/7.2.5, 4/7.2.5, UDF 2.3.1.1. */
+	terminator->tag.serial_num = lvint->tag.serial_num;
+
+	error = udf_write_dscr_phys(terminator, location, 1);
+	free(terminator);
+	assert(!error);
+	wpos++;
+	location++;
+
+	return 0;
+}
+
+
+static int
+udf_readin_partitions_free_space(void)
+{
+	union dscrptr *dscr;
+	struct part_desc *part;
+	struct part_hdr_desc *phd;
+	uint32_t bitmap_len, bitmap_lb;
+	int cnt, tagid, error;
+
+	/* XXX freed space bitmap ignored XXX */
+	error = 0;
+	for (cnt = 0; cnt < UDF_PARTITIONS; cnt++) {
+		part = context.partitions[cnt];
+		if (!part)
+			continue;
+
+		phd = &part->pd_part_hdr;
+		bitmap_len = udf_rw32(phd->unalloc_space_bitmap.len);
+		bitmap_lb  = udf_rw32(phd->unalloc_space_bitmap.lb_num);
+
+		if (bitmap_len == 0) {
+			error = 0;
+			continue;
+		}
+
+		if (!preen)
+			printf("Reading in free space map for partition %d\n", cnt);
+		error = udf_read_dscr_virt(bitmap_lb, cnt, &dscr);
+		if (error)
+			break;
+		if (!dscr) {
+			error = ENOENT;
+			break;
+		}
+		tagid = udf_rw16(dscr->tag.id);
+		if (tagid != TAGID_SPACE_BITMAP) {
+			pwarn("Unallocated space bitmap expected but got "
+			      "tag %d\n", tagid);
+			free(dscr);
+			error = ENOENT;
+			break;
+		}
+		if (udf_tagsize(dscr, context.sector_size) > bitmap_len) {
+			pwarn("Warning, size of read in bitmap %d is "
+			      "not equal to expected size %d\n",
+			      udf_tagsize(dscr, context.sector_size),
+			      bitmap_len);
+		}
+		context.part_unalloc_bits[cnt] = &dscr->sbd;
+	}
+
+	/* special case for metadata partitions */
+	for (cnt = 0; cnt < UDF_PMAPS; cnt++) {
+		if (context.vtop_tp[cnt] != UDF_VTOP_TYPE_META)
+			continue;
+		/* only if present */
+		if (layout.meta_bitmap == 0xffffffff)
+			continue;
+		if (!preen)
+			printf("Reading in free space map for partition %d\n", cnt);
+		error = udf_readin_file(
+				(union dscrptr *) context.meta_bitmap,
+				context.vtop[cnt],
+				(uint8_t **) &context.part_unalloc_bits[cnt],
+				NULL);
+		if (error) {
+			free(context.part_unalloc_bits[cnt]);
+			context.part_unalloc_bits[cnt] = NULL;
+			pwarn("implementation limit: metadata bitmap file read error, "
+			      "can't fix this up yet\n");
+			return error;
+		}
+	}
+	if (!preen)
+		printf("\n");
+
+	return error;
+}
+
+
+/* ------------------------- VAT support ------------------------- */
+
+/*
+ * 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(char *logvol_id)
+{
+	struct logvol_desc     *lvd = NULL;
+	struct fileset_desc    *fsd = NULL;
+	struct udf_lv_info     *lvi = NULL;
+
+	lvd = context.logical_vol;
+	fsd = context.fileset_desc;
+	if (context.implementation)
+		lvi = &context.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);
+}
+
+
+static struct timestamp *
+udf_file_mtime(union dscrptr *dscr)
+{
+	int tag_id = udf_rw16(dscr->tag.id);
+
+	assert((tag_id == TAGID_FENTRY) || (tag_id == TAGID_EXTFENTRY));
+	if (tag_id == TAGID_FENTRY)
+		return &dscr->fe.mtime;
+	else 
+		return &dscr->efe.mtime;
+	;
+}
+
+
+static void
+udf_print_vat_details(union dscrptr *dscr)
+{
+	printf("\n");
+	udf_print_timestamp("\tFound VAT timestamped at ",
+		udf_file_mtime(dscr), "\n");
+}
+
+
+static int
+udf_check_for_vat(union dscrptr *dscr)
+{
+	struct icb_tag   *icbtag;
+	uint32_t  vat_length;
+	int tag_id, filetype;
+
+	tag_id = udf_rw16(dscr->tag.id);
+
+	if ((tag_id != TAGID_FENTRY) && (tag_id != TAGID_EXTFENTRY))
+		return ENOENT;
+
+	if (tag_id == TAGID_FENTRY) {
+		vat_length = udf_rw64(dscr->fe.inf_len);
+		icbtag    = &dscr->fe.icbtag;
+	} else {
+		vat_length = udf_rw64(dscr->efe.inf_len);
+		icbtag = &dscr->efe.icbtag;
+	}
+	filetype = icbtag->file_type;
+	if ((filetype != 0) && (filetype != UDF_ICB_FILETYPE_VAT))
+		return ENOENT;
+
+	/* TODO sanity check vat length */
+	vat_length = vat_length;
+
+	return 0;
+}
+
+
+static int
+udf_extract_vat(union dscrptr *dscr, uint8_t **vat_contents)
+{
+	struct udf_fsck_file_stats	 stats;
+	struct icb_tag			*icbtag;
+	struct timestamp		*mtime;
+	struct udf_vat			*vat;
+	struct udf_oldvat_tail		*oldvat_tl;
+	struct udf_logvol_info		*lvinfo;
+	struct impl_extattr_entry	*implext;
+	struct vatlvext_extattr_entry	 lvext;
+	const char *extstr = "*UDF VAT LVExtension";
+	uint64_t vat_unique_id;
+	uint64_t vat_length;
+	uint32_t vat_entries, vat_offset;
+	uint32_t offset, a_l;
+	uint8_t *ea_start, *lvextpos;
+	char *regid_name;
+	int tag_id, filetype;
+	int error;
+
+	*vat_contents = NULL;
+	lvinfo = context.logvol_info;
+
+	/* read in VAT contents */
+	error = udf_readin_file(dscr, context.data_part, vat_contents, &stats);
+	if (error) {
+		error = ENOENT;
+		goto out;
+	}
+
+	/* tag_id already checked */
+	tag_id = udf_rw16(dscr->tag.id);
+	if (tag_id == TAGID_FENTRY) {
+		vat_length    = udf_rw64(dscr->fe.inf_len);
+		icbtag        = &dscr->fe.icbtag;
+		mtime         = &dscr->fe.mtime;
+		vat_unique_id = udf_rw64(dscr->fe.unique_id);
+		ea_start      = dscr->fe.data;
+	} else {
+		vat_length    = udf_rw64(dscr->efe.inf_len);
+		icbtag        = &dscr->efe.icbtag;
+		mtime         = &dscr->efe.mtime;
+		vat_unique_id = udf_rw64(dscr->efe.unique_id);
+		ea_start      = dscr->efe.data;	/* for completion */
+	}
+
+	if (vat_length > stats.inf_len) {
+		error = ENOENT;
+		goto out;
+	}
+
+	/* file type already checked */
+	filetype = icbtag->file_type;
+
+	/* extract info from our VAT data */
+	if (filetype == 0) {
+		/* VAT 1.50 format */
+		/* definition */
+		vat_offset = 0;
+		vat_entries = (vat_length-36)/4;
+		oldvat_tl = (struct udf_oldvat_tail *)
+			(*vat_contents + vat_entries * 4);
+		regid_name = (char *) oldvat_tl->id.id;
+		error = strncmp(regid_name, "*UDF Virtual Alloc Tbl", 22);
+		if (error) {
+			pwarn("Possible VAT 1.50 detected without tail\n");
+			if (ask_noauto(0, "Accept anyway")) {
+				vat_entries = vat_length/4;
+				vat_writeout = 1;
+				error = 0;
+				goto ok;
+			}
+			pwarn("VAT format 1.50 rejected\n");
+			error = ENOENT;
+			goto out;
+		}
+
+		/*
+		 * The following VAT extensions are optional and ignored but
+		 * demand a clean VAT write out for sanity.
+		 */
+		error = udf_extattr_search_intern(dscr, 2048, extstr, &offset, &a_l);
+		if (error) {
+			/* VAT LVExtension extended attribute missing */
+			vat_writeout = 1;
+			goto ok;
+		}
+
+		implext = (struct impl_extattr_entry *) (ea_start + offset);
+		error = udf_impl_extattr_check(implext);
+		if (error) {
+			/* VAT LVExtension checksum failed */
+			vat_writeout = 1;
+			goto ok;
+		}
+
+		/* paranoia */
+		if (a_l != sizeof(*implext) -2 + udf_rw32(implext->iu_l) + sizeof(lvext)) {
+			/* VAT LVExtension size doesn't compute */
+			vat_writeout = 1;
+			goto ok;
+		}
+
+		/*
+		 * 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 (!!)
+		 */
+		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_unique_id) {
+			lvinfo->num_files       = lvext.num_files;
+			lvinfo->num_directories = lvext.num_directories;
+			udf_update_logvolname(lvext.logvol_id);
+		} else {
+			/* VAT LVExtension out of date */
+			vat_writeout = 1;
+		}
+	} else {
+		/* VAT 2.xy format */
+		/* definition */
+		vat = (struct udf_vat *) (*vat_contents);
+		vat_offset  = udf_rw16(vat->header_len);
+		vat_entries = (vat_length - vat_offset)/4;
+
+		if (heuristics) {
+			if (vat->impl_use_len == 0) {
+				uint32_t start_val;
+				start_val = udf_rw32(*((uint32_t *) vat->data));
+				if (start_val == 0x694d2a00) {
+					/* "<0>*Mic"osoft Windows */
+					pwarn("Heuristics found corrupted MS Windows VAT\n");
+					if (ask(0, "Repair")) {
+						vat->impl_use_len = udf_rw16(32);
+						vat->header_len = udf_rw16(udf_rw16(vat->header_len) + 32);
+						vat_offset += 32;
+						vat_writeout = 1;
+					}
+				}
+			}
+		}
+		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(vat->logvol_id);
+	}
+
+/* XXX FAULT INJECTION POINT XXX */
+//vat_writeout = 1;
+
+ok:
+	/* extra sanity checking */
+	if (tag_id == TAGID_FENTRY) {
+		/* nothing checked as yet */
+	} else {
+		/*
+		 * The following VAT violations are ignored but demand a clean VAT
+		 * writeout for sanity
+		 */
+		if (!is_zero(&dscr->efe.streamdir_icb, sizeof(struct long_ad))) {
+			/* VAT specification violation:
+			 * 	VAT has no cleared streamdir reference */
+			vat_writeout = 1;
+		}
+		if (!is_zero(&dscr->efe.ex_attr_icb, sizeof(struct long_ad))) {
+			/* VAT specification violation:
+			 * 	VAT has no cleared extended attribute reference */
+			vat_writeout = 1;
+		}
+		if (dscr->efe.obj_size != dscr->efe.inf_len) {
+			/* VAT specification violation:
+			 * 	VAT has invalid object size */
+			vat_writeout = 1;
+		}
+	}
+
+	if (!vat_writeout) {
+		context.logvol_integrity->lvint_next_unique_id = udf_rw64(vat_unique_id);
+		context.logvol_integrity->integrity_type = udf_rw32(UDF_INTEGRITY_CLOSED);
+		context.logvol_integrity->time           = *mtime;
+	}
+
+	context.unique_id     = vat_unique_id;
+	context.vat_allocated = UDF_ROUNDUP(vat_length, context.sector_size);
+	context.vat_contents  = *vat_contents;
+	context.vat_start     = vat_offset;
+	context.vat_size      = vat_offset + vat_entries * 4;
+
+out:
+	if (error) {
+		free(*vat_contents);
+		*vat_contents = NULL;
+	}
+
+	return error;
+}
+
+
+#define VAT_BLK 256
+static int
+udf_search_vat(union udf_pmap *mapping, int log_part)
+{
+	union dscrptr *vat_candidate, *accepted_vat;
+	struct part_desc *pdesc;
+	struct mmc_trackinfo *ti, *ti_s;
+	uint32_t part_start;
+	uint32_t vat_loc, early_vat_loc, late_vat_loc, accepted_vat_loc;
+	uint32_t first_possible_vat_location, last_possible_vat_location;
+	uint8_t *vat_contents, *accepted_vat_contents;
+	int num_tracks, tracknr, found_a_VAT, valid_loc, error;
+
+	/*
+	 * 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.
+	 */
+
+	/* get complete list of all our valid ranges */
+	ti_s = calloc(mmc_discinfo.num_tracks, sizeof(struct mmc_trackinfo));
+	for (tracknr = 1; tracknr <= mmc_discinfo.num_tracks; tracknr++) {
+		ti = &ti_s[tracknr];
+		ti->tracknr = tracknr;
+		(void) udf_update_trackinfo(ti);
+	}
+
+	/* derive our very first track number our base partition covers */
+	pdesc = context.partitions[context.data_part];
+	part_start = udf_rw32(pdesc->start_loc);
+	for (int cnt = 0; cnt < UDF_PARTITIONS; cnt++) {
+		pdesc = context.partitions[cnt];
+		if (!pdesc)
+			continue;
+		part_start = MIN(part_start, udf_rw32(pdesc->start_loc));
+	}
+	num_tracks = mmc_discinfo.num_tracks;
+	for (tracknr = 1, ti = NULL; tracknr <= num_tracks; tracknr++) {
+		ti = &ti_s[tracknr];
+		if ((part_start >= ti->track_start) &&
+				(part_start <= ti->track_start + ti->track_size))
+			break;
+	}
+	context.first_ti_partition = *ti;
+
+	first_possible_vat_location = context.first_ti_partition.track_start;
+	last_possible_vat_location  = context.last_ti.track_start +
+			context.last_ti.track_size -
+			context.last_ti.free_blocks + 1;
+
+	/* initial guess is around 16 sectors back */
+	late_vat_loc = last_possible_vat_location;
+	early_vat_loc = MAX(late_vat_loc - 16, first_possible_vat_location);
+
+	if (!preen)
+		printf("Full VAT range search from %d to %d\n",
+			first_possible_vat_location,
+			last_possible_vat_location);
+
+	vat_writeout = 0;
+	accepted_vat = NULL;
+	accepted_vat_contents = NULL;
+	accepted_vat_loc = 0;
+	do {
+		vat_loc = early_vat_loc;
+		if (!preen) {
+			printf("\tChecking range %8d to %8d\n",
+					early_vat_loc, late_vat_loc);
+			fflush(stdout);
+		}
+		found_a_VAT = 0;
+		while (vat_loc <= late_vat_loc) {
+			if (print_info) {
+				pwarn("\nchecking for VAT in sector %8d\n", vat_loc);
+				print_info = 0;
+			}
+			/* check if its in readable range */
+			valid_loc = 0;
+			for (tracknr = 1; tracknr <= num_tracks; tracknr++) {
+				ti = &ti_s[tracknr];
+				if (!(ti->flags & MMC_TRACKINFO_BLANK) &&
+					((vat_loc >= ti->track_start) &&
+					    (vat_loc <= ti->track_start + ti->track_size))) {
+					valid_loc = 1;
+					break;
+				}
+			}
+			if (!valid_loc) {
+				vat_loc++;
+				continue;
+			}
+
+			error = udf_read_dscr_phys(vat_loc, &vat_candidate);
+			if (!vat_candidate)
+				error = ENOENT;
+			if (!error)
+				error = udf_check_for_vat(vat_candidate);
+			if (error) {
+				vat_loc++;	/* walk forward */
+				continue;
+			}
+
+			if (accepted_vat) {
+				/* check if newer vat time stamp is the same */
+				if (udf_compare_mtimes(
+						udf_file_mtime(vat_candidate),
+						udf_file_mtime(accepted_vat)
+						) == 0) {
+					free(vat_candidate);
+					vat_loc++;	/* walk forward */
+					continue;
+				}
+			}
+
+			/* check if its contents are OK */
+			error = udf_extract_vat(
+					vat_candidate, &vat_contents);
+			if (error) {
+				/* unlikely */
+				// pwarn("Unreadable or malformed VAT encountered\n");
+				free(vat_candidate);
+				vat_loc++;
+				continue;
+			}
+			/* accept new vat */
+			free(accepted_vat);
+			free(accepted_vat_contents);
+
+			accepted_vat = vat_candidate;
+			accepted_vat_contents = vat_contents;
+			accepted_vat_loc = vat_loc;
+			vat_candidate = NULL;
+			vat_contents  = NULL;
+
+			found_a_VAT = 1;
+
+			vat_loc++;	/* walk forward */
+		};
+
+		if (found_a_VAT && accepted_vat) {
+			/* VAT accepted */
+			if (!preen)
+				udf_print_vat_details(accepted_vat);
+			if (vat_writeout)
+				pwarn("\tVAT accepted but marked dirty\n");
+			if (!preen && !vat_writeout)
+				pwarn("\tLogical volume integrity state set to CLOSED\n");
+			if (!search_older_vat)
+				break;
+			if (!ask_noauto(0, "\tSearch older VAT"))
+				break;
+			late_vat_loc  = accepted_vat_loc - 1;
+		} else {
+			late_vat_loc = early_vat_loc - 1;
+		}
+		early_vat_loc = first_possible_vat_location;
+		if (late_vat_loc > VAT_BLK)
+			early_vat_loc = MAX(early_vat_loc, late_vat_loc - VAT_BLK);
+	} while (late_vat_loc > first_possible_vat_location);
+
+	if (!preen)
+		printf("\n");
+
+	undo_opening_session = 0;
+
+	if (!accepted_vat) {
+		if ((context.last_ti.sessionnr > 1) && 
+				ask_noauto(0, "Undo opening of last session")) {
+			undo_opening_session = 1;
+			pwarn("Undoing opening of last session not implemented!\n");
+			error = ENOENT;
+			goto error_out;
+		} else {
+			pwarn("No valid VAT found!\n");
+			error = ENOENT;
+			goto error_out;
+		}
+	}
+	if (last_possible_vat_location - accepted_vat_loc > 16) {
+		assert(accepted_vat);
+		pwarn("Selected VAT is not the latest or not at the end of "
+			"track.\n");
+			vat_writeout = 1;
+	}
+
+/* XXX FAULT INJECTION POINT XXX */
+//vat_writeout = 1;
+//udf_update_lvintd(UDF_INTEGRITY_OPEN);
+
+	return 0;
+
+error_out:
+	free(accepted_vat);
+	free(accepted_vat_contents);
+
+	return error;
+}
+
+/* ------------------------- sparables support ------------------------- */
+
+static int
+udf_read_spareables(union udf_pmap *mapping, int log_part)
+{
+	union dscrptr *dscr;
+	struct part_map_spare *pms = &mapping->pms;
+	uint32_t lb_num;
+	int spar, error;
+
+	for (spar = 0; spar < pms->n_st; spar++) {
+		lb_num = pms->st_loc[spar];
+		error = udf_read_dscr_phys(lb_num, &dscr);
+		if (error && !preen)
+			pwarn("Error reading spareable table %d\n", spar);
+		if (!error && dscr) {
+			if (udf_rw16(dscr->tag.id) == TAGID_SPARING_TABLE) {
+				free(context.sparing_table);
+				context.sparing_table = &dscr->spt;
+				dscr = NULL;
+				break;	/* we're done */
+			}
+		}
+		free(dscr);
+	}
+	if (context.sparing_table == NULL)
+		return ENOENT;
+	return 0;
+}
+
+/* ------------------------- metadata support ------------------------- */
+
+static bool
+udf_metadata_node_supported(void)
+{
+	struct extfile_entry   *efe;
+	struct short_ad        *short_ad;
+	uint32_t len;
+	uint32_t flags;
+	uint8_t *data_pos;
+	int dscr_size, l_ea, l_ad, icbflags, addr_type;
+
+	/* we have to look into the file's allocation descriptors */
+
+	efe = context.meta_file;
+	dscr_size = sizeof(struct extfile_entry) - 1;
+	l_ea = udf_rw32(efe->l_ea);
+	l_ad = udf_rw32(efe->l_ad);
+
+	icbflags = udf_rw16(efe->icbtag.flags);
+	addr_type = icbflags & UDF_ICB_TAG_FLAGS_ALLOC_MASK;
+	if (addr_type != UDF_ICB_SHORT_ALLOC) {
+		warnx("specification violation: metafile not using"
+			"short allocs");
+		return false;
+	}
+
+	data_pos = (uint8_t *) context.meta_file + dscr_size + l_ea;
+	short_ad = (struct short_ad *) data_pos;
+	while (l_ad > 0) {
+		len      = udf_rw32(short_ad->len);
+		flags    = UDF_EXT_FLAGS(len);
+		if (flags == UDF_EXT_REDIRECT) {
+			warnx("implementation limit: no support for "
+			      "extent redirections in metadata file");
+			return false;
+		}
+		short_ad++;
+		l_ad -= sizeof(struct short_ad);
+	}
+	/* we passed all of them */
+	return true;
+}
+
+
+static int
+udf_read_metadata_nodes(union udf_pmap *mapping, int log_part)
+{
+	union dscrptr *dscr1, *dscr2, *dscr3;
+	struct part_map_meta *pmm = &mapping->pmm;
+	uint16_t raw_phys_part, phys_part;
+	int tagid, file_type, error;
+
+	/*
+	 * BUGALERT: some rogue implementations use random physical
+	 * partition numbers to break other implementations so lookup
+	 * the number.
+	 */
+
+	raw_phys_part = udf_rw16(pmm->part_num);
+	phys_part = udf_find_raw_phys(raw_phys_part);
+
+	error = udf_read_dscr_virt(layout.meta_file, phys_part, &dscr1);
+	if (!error) {
+		tagid = udf_rw16(dscr1->tag.id);
+		file_type = dscr1->efe.icbtag.file_type;
+		if ((tagid != TAGID_EXTFENTRY) ||
+				(file_type != UDF_ICB_FILETYPE_META_MAIN))
+			error = ENOENT;
+	}
+	if (error) {
+		pwarn("Bad primary metadata file descriptor\n");
+		free(dscr1);
+		dscr1 = NULL;
+	}
+
+	error = udf_read_dscr_virt(layout.meta_mirror, phys_part, &dscr2);
+	if (!error) {
+		tagid = udf_rw16(dscr2->tag.id);
+		file_type = dscr2->efe.icbtag.file_type;
+		if ((tagid != TAGID_EXTFENTRY) ||
+				(file_type != UDF_ICB_FILETYPE_META_MIRROR))
+			error = ENOENT;
+	}
+	if (error) {
+		pwarn("Bad mirror metadata file descriptor\n");
+		free(dscr2);
+		dscr2 = NULL;
+	}
+
+	if ((dscr1 == NULL) && (dscr2 == NULL)) {
+		pwarn("No valid metadata file descriptors found!\n");
+		return -1;
+	}
+
+	error = 0;
+	if ((dscr1 == NULL) && dscr2) {
+		dscr1 = malloc(context.sector_size);
+		memcpy(dscr1, dscr2, context.sector_size);
+		dscr1->efe.icbtag.file_type = UDF_ICB_FILETYPE_META_MAIN;
+		if (ask(1, "Fix up bad primary metadata file descriptor")) {
+			error = udf_write_dscr_virt(dscr1,
+					layout.meta_file, phys_part, 1);
+		}
+	}
+	if (dscr1 && (dscr2 == NULL)) {
+		dscr2 = malloc(context.sector_size);
+		memcpy(dscr2, dscr1, context.sector_size);
+		dscr2->efe.icbtag.file_type = UDF_ICB_FILETYPE_META_MIRROR;
+		if (ask(1, "Fix up bad mirror metadata file descriptor")) {
+			error = udf_write_dscr_virt(dscr2,
+					layout.meta_mirror, phys_part, 1);
+		}
+	}
+	if (error)
+		pwarn("Copying metadata file descriptor failed, "
+		      "trying to continue\n");
+
+	context.meta_file   = &dscr1->efe;
+	context.meta_mirror = &dscr2->efe;
+
+	dscr3 = NULL;
+	if (layout.meta_bitmap != 0xffffffff) {
+		error = udf_read_dscr_virt(layout.meta_bitmap, phys_part, &dscr3);
+		if (!error) {
+			tagid = udf_rw16(dscr3->tag.id);
+			file_type = dscr3->efe.icbtag.file_type;
+			if ((tagid != TAGID_EXTFENTRY) ||
+					(file_type != UDF_ICB_FILETYPE_META_BITMAP))
+				error = ENOENT;
+		}
+		if (error) {
+			pwarn("Bad metadata bitmap file descriptor\n");
+			free(dscr3);
+			dscr3 = NULL;
+		}
+
+		if (dscr3 == NULL) {
+			pwarn("implementation limit: can't repair missing or "
+			      "damaged metadata bitmap descriptor\n");
+			return -1;
+		}
+
+		context.meta_bitmap = &dscr3->efe;
+	}
+
+	/* TODO early check if meta_file has allocation extent redirections */
+	if (!udf_metadata_node_supported())
+		return EINVAL;
+
+	return 0;
+}
+
+/* ------------------------- VDS readin ------------------------- */
+
+/* checks if the VDS information is correct and complete */
+static int
+udf_process_vds(void) {
+	union dscrptr *dscr;
+	union udf_pmap *mapping;
+	struct part_desc *pdesc;
+	struct long_ad fsd_loc;
+	uint8_t *pmap_pos;
+	char *domain_name, *map_name;
+	const char *check_name;	
+	int pmap_stype, pmap_size;
+	int pmap_type, log_part, phys_part, raw_phys_part; //, maps_on;
+	int n_pm, n_phys, n_virt, n_spar, n_meta;
+	int len, error;
+
+	/* we need at least an anchor (trivial, but for safety) */
+	if (context.anchors[0] == NULL) {
+		pwarn("sanity check: no anchors?\n");
+		return EINVAL;
+	}
+
+	/* we need at least one primary and one logical volume descriptor */
+	if ((context.primary_vol == NULL) || (context.logical_vol) == NULL) {
+		pwarn("sanity check: missing primary or missing logical volume\n");
+		return EINVAL;
+	}
+
+	/* we need at least one partition descriptor */
+	if (context.partitions[0] == NULL) {
+		pwarn("sanity check: missing partition descriptor\n");
+		return EINVAL;
+	}
+
+	/* check logical volume sector size versus device sector size */
+	if (udf_rw32(context.logical_vol->lb_size) != context.sector_size) {
+		pwarn("sanity check: lb_size != sector size\n");
+		return EINVAL;
+	}
+
+	/* check domain name, should never fail */
+	domain_name = (char *) context.logical_vol->domain_id.id;
+	if (strncmp(domain_name, "*OSTA UDF Compliant", 20)) {
+		pwarn("sanity check: disc not OSTA UDF Compliant, aborting\n");
+		return EINVAL;
+	}
+
+	/* retrieve logical volume integrity sequence */
+	udf_retrieve_lvint();
+
+	/* check if we support this disc, ie less or equal to 0x250 */
+	if (udf_rw16(context.logvol_info->min_udf_writever) > 0x250) {
+		pwarn("implementation limit: minimum write version UDF 2.60 "
+		      "and on are not supported\n");
+		return EINVAL;
+	}
+
+	/*
+	 * check logvol mappings: effective virt->log partmap translation
+	 * check and recording of the mapping results. Saves expensive
+	 * strncmp() in tight places.
+	 */
+	n_pm = udf_rw32(context.logical_vol->n_pm);   /* num partmaps         */
+	pmap_pos =  context.logical_vol->maps;
+
+	if (n_pm > UDF_PMAPS) {
+		pwarn("implementation limit: too many logvol mappings\n");
+		return EINVAL;
+	}
+
+	/* count types and set partition numbers */
+	context.data_part = context.metadata_part = context.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++;
+			context.data_part     = log_part;
+			context.metadata_part = log_part;
+			context.fids_part     = log_part;
+			break;
+		case 2: /* virtual/sparable/meta mapping */
+			map_name  = (char *) 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++;
+				context.metadata_part = log_part;
+				context.format_flags |= FORMAT_VAT;
+				break;
+			}
+			check_name = "*UDF Sparable Partition";
+			if (strncmp(map_name, check_name, len) == 0) {
+				pmap_type = UDF_VTOP_TYPE_SPAREABLE;
+				n_spar++;
+				layout.spareable_blockingnr = udf_rw16(mapping->pms.packet_len);
+
+				context.data_part     = log_part;
+				context.metadata_part = log_part;
+				context.fids_part     = log_part;
+				context.format_flags |= FORMAT_SPAREABLE;
+				break;
+			}
+			check_name = "*UDF Metadata Partition";
+			if (strncmp(map_name, check_name, len) == 0) {
+				pmap_type = UDF_VTOP_TYPE_META;
+				n_meta++;
+				layout.meta_file	= udf_rw32(mapping->pmm.meta_file_lbn);
+				layout.meta_mirror	= udf_rw32(mapping->pmm.meta_mirror_file_lbn);
+				layout.meta_bitmap	= udf_rw32(mapping->pmm.meta_bitmap_file_lbn);
+				layout.meta_blockingnr	= udf_rw32(mapping->pmm.alloc_unit_size);
+				layout.meta_alignment	= udf_rw16(mapping->pmm.alignment_unit_size);
+				/* XXX metadata_flags in mapping->pmm.flags? XXX */
+
+				context.metadata_part = log_part;
+				context.fids_part     = log_part;
+				context.format_flags |= FORMAT_META;
+				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(raw_phys_part);
+
+		if (phys_part == UDF_PARTITIONS) {
+			pwarn("implementation limit: too many partitions\n");
+			return EINVAL;
+		}
+		if (pmap_type == UDF_VTOP_TYPE_UNKNOWN) {
+			pwarn("implementation limit: encountered unknown "
+				"logvol mapping `%s`!\n", map_name);
+			return EINVAL;
+		}
+
+		context.vtop   [log_part] = phys_part;
+		context.vtop_tp[log_part] = pmap_type;
+
+		pmap_pos += pmap_size;
+	}
+	/* not winning the beauty contest */
+	context.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)) {
+		pwarn("Sanity check: format error, more than one "
+		      "virtual, sparable or meta mapping\n");
+		return EINVAL;
+	}
+
+	if (n_virt) {
+		if ((n_phys == 0) || n_spar || n_meta) {
+			pwarn("Sanity check: format error, no backing for "
+			      "virtual partition\n");
+			return EINVAL;
+		}
+	}
+	if (n_spar + n_phys == 0) {
+		pwarn("Sanity check: can't combine a sparable and a "
+		      "physical partition\n");
+		return EINVAL;
+	}
+
+	/* print format type as derived */
+	if (!preen) {
+		char bits[255];
+		snprintb(bits, sizeof(bits), FORMAT_FLAGBITS, context.format_flags);
+		printf("Format flags %s\n\n", bits);
+	}
+
+	/* read supporting tables */
+	pmap_pos =  context.logical_vol->maps;
+	for (log_part = 0; log_part < n_pm; log_part++) {
+		mapping = (union udf_pmap *) pmap_pos;
+		pmap_size  = pmap_pos[1];
+		switch (context.vtop_tp[log_part]) {
+		case UDF_VTOP_TYPE_PHYS :
+			/* nothing */
+			break;
+		case UDF_VTOP_TYPE_VIRT :
+			/* search and load VAT */
+			error = udf_search_vat(mapping, log_part);
+			if (error) {
+				pwarn("Couldn't find virtual allocation table\n");
+				return ENOENT;
+			}
+			break;
+		case UDF_VTOP_TYPE_SPAREABLE :
+			/* load one of the sparable tables */
+			error = udf_read_spareables(mapping, log_part);
+			if (error) {
+				pwarn("Couldn't load sparable blocks tables\n");
+				return ENOENT;
+			}
+			break;
+		case UDF_VTOP_TYPE_META :
+			/* load the associated file descriptors */
+			error = udf_read_metadata_nodes(mapping, log_part);
+			if (error) {
+				pwarn("Couldn't read in the metadata descriptors\n");
+				return ENOENT;
+			}
+
+			/*
+			 * We have to extract the partition size from the meta
+			 * data file length
+			 */
+			context.part_size[log_part] =
+				udf_rw32(context.meta_file->inf_len) / context.sector_size;
+			break;
+		default:
+			break;
+		}
+		pmap_pos += pmap_size;
+	}
+
+	/*
+	 * Free/unallocated space bitmap readin delayed; the FS might be
+	 * closed already; no need to read in copious amount of data only to
+	 * not use it later.
+	 *
+	 * For now, extract partition sizes in our context
+	 */
+	for (int cnt = 0; cnt < UDF_PARTITIONS; cnt++) {
+		pdesc = context.partitions[cnt];
+		if (!pdesc)
+			continue;
+
+		context.part_size[cnt] = udf_rw32(pdesc->part_len);
+		context.part_unalloc_bits[cnt] = NULL;
+	}
+
+	/* read file set descriptor */
+	fsd_loc = context.logical_vol->lv_fsd_loc;
+	error = udf_read_dscr_virt(
+			udf_rw32(fsd_loc.loc.lb_num),
+			udf_rw16(fsd_loc.loc.part_num), &dscr);
+	if (error) {
+		pwarn("Couldn't read in file set descriptor\n");
+		pwarn("implementation limit: can't fix this\n");
+		return ENOENT;
+	}
+	if (udf_rw16(dscr->tag.id) != TAGID_FSD) {
+		pwarn("Expected fsd at (p %d, lb %d)\n",
+				udf_rw16(fsd_loc.loc.part_num),
+				udf_rw32(fsd_loc.loc.lb_num));
+		pwarn("File set descriptor not pointing to a file set!\n");
+		return ENOENT;
+	}
+	context.fileset_desc = &dscr->fsd;
+
+	/* signal its OK for now */
+	return 0;
+}
+
+
+#define UDF_UPDATE_DSCR(name, dscr) \
+	if (name) {\
+		free (name); \
+		updated = 1; \
+	} \
+	name = calloc(1, dscr_size); \
+	memcpy(name, dscr, dscr_size);
+
+static void
+udf_process_vds_descriptor(union dscrptr *dscr, int dscr_size) {
+	struct pri_vol_desc *pri;
+	struct logvol_desc *lvd;
+	uint16_t raw_phys_part, phys_part;
+	int updated = 0;
+
+	switch (udf_rw16(dscr->tag.id)) {
+	case TAGID_PRI_VOL :		/* primary partition */
+		UDF_UPDATE_DSCR(context.primary_vol, dscr);
+		pri = context.primary_vol;
+
+		context.primary_name = malloc(32);
+		context.volset_name  = malloc(128);
+
+		udf_to_unix_name(context.volset_name, 32, pri->volset_id, 32,
+			&pri->desc_charset);
+		udf_to_unix_name(context.primary_name, 128, pri->vol_id, 128,
+			&pri->desc_charset);
+
+		if (!preen && !updated) {
+			pwarn("Volume set       `%s`\n", context.volset_name);
+			pwarn("Primary volume   `%s`\n", context.primary_name);
+		}
+		break;
+	case TAGID_LOGVOL :		/* logical volume    */
+		UDF_UPDATE_DSCR(context.logical_vol, dscr);
+		/* could check lvd->domain_id */
+		lvd = context.logical_vol;
+		context.logvol_name = malloc(128);
+
+		udf_to_unix_name(context.logvol_name, 128, lvd->logvol_id, 128,
+			&lvd->desc_charset);
+
+		if (!preen && !updated)
+			pwarn("Logical volume   `%s`\n", context.logvol_name);
+		break;
+	case TAGID_UNALLOC_SPACE :	/* unallocated space */
+		UDF_UPDATE_DSCR(context.unallocated, dscr);
+		break;
+	case TAGID_IMP_VOL :		/* implementation    */
+		UDF_UPDATE_DSCR(context.implementation, dscr);
+		break;
+	case TAGID_PARTITION :		/* partition(s)	     */
+		/* not much use if its not allocated */
+		if ((udf_rw16(dscr->pd.flags) & UDF_PART_FLAG_ALLOCATED) == 0) {
+			pwarn("Ignoring unallocated partition\n");
+			break;
+		}
+		raw_phys_part = udf_rw16(dscr->pd.part_num);
+		phys_part = udf_find_raw_phys(raw_phys_part);
+
+		if (phys_part >= UDF_PARTITIONS) {
+			pwarn("Too many physical partitions, ignoring\n");
+			break;
+		}
+		UDF_UPDATE_DSCR(context.partitions[phys_part], dscr);
+		break;
+	case TAGID_TERM :		/* terminator        */
+		break;
+	case TAGID_VOL :		/* volume space ext  */
+		pwarn("Ignoring VDS extender\n");
+		break;
+	default :
+		pwarn("Unknown VDS type %d found, ignored\n",
+			udf_rw16(dscr->tag.id));
+	}
+}
+
+
+static void
+udf_read_vds_extent(union dscrptr *dscr, int vds_size) {
+	uint8_t *pos;
+	int sector_size = context.sector_size;
+	int dscr_size;
+
+	pos = (uint8_t *) dscr;
+	while (vds_size) {
+		/* process the descriptor */
+		dscr = (union dscrptr *) pos;
+
+		/* empty block terminates */
+		if (is_zero(dscr, sector_size))
+			return;
+
+		/* terminator terminates */
+		if (udf_rw16(dscr->tag.id) == TAGID_TERM)
+			return;
+
+		if (udf_check_tag(dscr))
+			pwarn("Bad descriptor sum in vds, ignoring\n");
+
+		dscr_size = udf_tagsize(dscr, sector_size);
+		if (udf_check_tag_payload(dscr, dscr_size))
+			pwarn("Bad descriptor CRC in vds, ignoring\n");
+
+		udf_process_vds_descriptor(dscr, dscr_size);
+
+		pos      += dscr_size;
+		vds_size -= dscr_size;
+	}
+}
+
+
+static int
+udf_copy_VDS_area(void *destbuf, void *srcbuf)
+{
+	pwarn("TODO implement VDS copy area, signalling success\n");
+	return 0;
+}
+
+
+/* XXX why two buffers and not just read descritor by descriptor XXX */
+static int
+udf_check_VDS_areas(void) {
+	union dscrptr *vds1_buf, *vds2_buf;
+	int vds1_size, vds2_size;
+	int error, error1, error2;
+
+	vds1_size = layout.vds1_size * context.sector_size;
+	vds2_size = layout.vds2_size * context.sector_size;
+	vds1_buf = calloc(1, vds1_size);
+	vds2_buf = calloc(1, vds2_size);
+	assert(vds1_buf); assert(vds2_buf);
+
+	error1 = udf_read_phys(vds1_buf, layout.vds1, layout.vds1_size);
+	error2 = udf_read_phys(vds2_buf, layout.vds2, layout.vds2_size);
+
+	if (error1 && error2) {
+		pwarn("Can't read both volume descriptor areas!\n");
+		return -1;
+	}
+
+	if (!error1) {
+		/* retrieve data from VDS 1 */
+		udf_read_vds_extent(vds1_buf, vds1_size);
+		context.vds_buf  = vds1_buf;
+		context.vds_size = vds1_size;
+		free(vds2_buf);
+	}
+	if (!error2) {
+		/* retrieve data from VDS 2 */
+		udf_read_vds_extent(vds2_buf, vds2_size);
+		context.vds_buf  = vds2_buf;
+		context.vds_size = vds2_size;
+		free(vds1_buf);
+	}
+	/* check if all is correct and complete */
+	error = udf_process_vds();
+	if (error)
+		return error;
+
+	/* TODO check if both area's are logically the same */
+	error = 0;
+	if (!error1 && error2) {
+		/* first OK, second faulty */
+		pwarn("Backup volume descriptor missing or damaged\n");
+		if (context.format_flags & FORMAT_SEQUENTIAL) {
+			pwarn("Can't fixup backup volume descriptor on "
+			      "SEQUENTIAL media\n");
+		} else if (ask(1, "Fixup backup volume descriptor")) {
+			error = udf_copy_VDS_area(vds2_buf, vds1_buf);
+			pwarn("\n");
+		}
+	}
+	if (error1 && !error2) {
+		/* second OK, first faulty */
+		pwarn("Primary volume descriptor missing or damaged\n");
+		if (context.format_flags & FORMAT_SEQUENTIAL) {
+			pwarn("Can't fix up primary volume descriptor on "
+			      "SEQUENTIAL media\n");
+		} else if (ask(1, "Fix up primary volume descriptor")) {
+			error = udf_copy_VDS_area(vds1_buf, vds2_buf);
+		}
+	}
+	if (error)
+		pwarn("copying VDS areas failed!\n");
+	if (!preen)
+		printf("\n");
+
+	return error;
+}
+
+/* --------------------------------------------------------------------- */
+
+static int
+udf_prepare_writing(void)
+{
+	union dscrptr *zero_dscr, *dscr;
+	struct mmc_trackinfo ti;
+	uint32_t first_lba, loc;
+	int sector_size = context.sector_size;
+	int error;
+
+	error = udf_prepare_disc();
+	if (error) {
+		pwarn("*** Preparing disc for writing failed!\n");
+		return error;
+	}
+
+	/* if we are not on sequential media, we're done */
+	if ((mmc_discinfo.mmc_cur & MMC_CAP_SEQUENTIAL) == 0)
+		return 0;
+	assert(context.format_flags & FORMAT_VAT);
+
+	/* if the disc is full, we drop back to read only */
+	if (mmc_discinfo.disc_state == MMC_STATE_FULL)
+		rdonly = 1;
+	if (rdonly)
+		return 0;
+
+	/* check if we need to open the last track */
+	ti.tracknr = mmc_discinfo.last_track_last_session;
+	error = udf_update_trackinfo(&ti);
+	if (error)
+		return error;
+	if (!(ti.flags & MMC_TRACKINFO_BLANK) && 
+	     (ti.flags & MMC_TRACKINFO_NWA_VALID)) {
+		/*
+		 * Not closed; translate next_writable to a position relative to our
+		 * backing partition
+		 */
+		context.alloc_pos[context.data_part] = ti.next_writable -
+			udf_rw32(context.partitions[context.data_part]->start_loc);
+		wrtrack_skew = ti.next_writable % layout.blockingnr;
+		return 0;
+	}
+	assert(ti.flags & MMC_TRACKINFO_NWA_VALID);
+
+	/* just in case */
+	udf_suspend_writing();
+
+	/* 'add' a new track */
+	udf_update_discinfo();
+	memset(&context.last_ti, 0, sizeof(struct mmc_trackinfo));
+	context.last_ti.tracknr = mmc_discinfo.first_track_last_session;
+	(void) udf_update_trackinfo(&context.last_ti);
+
+	assert(mmc_discinfo.last_session_state == MMC_STATE_EMPTY);
+	first_lba = context.last_ti.track_start;
+	wrtrack_skew = context.last_ti.track_start % layout.blockingnr;
+
+	/*
+	 * location of iso9660 vrs is defined as first sector AFTER 32kb,
+	 * minimum `sector size' 2048
+	 */
+	layout.iso9660_vrs = ((32*1024 + sector_size - 1) / sector_size)
+		+ first_lba;
+
+	/* anchor starts at specified offset in sectors */
+	layout.anchors[0] = first_lba + 256;
+
+	/* ready for appending, write preamble, we are using overwrite here! */
+	if ((zero_dscr = calloc(1, context.sector_size)) == NULL)
+		return ENOMEM;
+	loc = first_lba;
+	for (; loc < first_lba + 256; loc++) {
+		if ((error = udf_write_sector(zero_dscr, loc))) {
+			free(zero_dscr);
+			return error;
+		}
+	}
+	free(zero_dscr);
+
+	/* write new ISO9660 volume recognition sequence */
+	if ((error = udf_write_iso9660_vrs())) {
+		pwarn("internal error: can't write iso966 VRS in new session!\n");
+		rdonly = 1;
+		return error;
+	}
+
+	/* write out our old anchor, VDS spaces will be reused */
+	assert(context.anchors[0]);
+	dscr = (union dscrptr *) context.anchors[0];
+	loc  = layout.anchors[0];
+	if ((error = udf_write_dscr_phys(dscr, loc, 1))) {
+		pwarn("internal error: can't write anchor in new session!\n");
+		rdonly = 1;
+		return error;
+	}
+
+	context.alloc_pos[context.data_part] = first_lba + 257 -
+		udf_rw32(context.partitions[context.data_part]->start_loc);
+
+	return 0;
+}
+
+
+static int
+udf_close_volume_vat(void)
+{
+	int integrity_type;
+
+	/* only write out when its open */
+	integrity_type = udf_rw32(context.logvol_integrity->integrity_type);
+	if (integrity_type == UDF_INTEGRITY_CLOSED)
+		return 0;
+
+	if (!preen)
+		printf("\n");
+	if (!ask(1, "Write out modifications"))
+		return 0;
+
+	/* writeout our VAT contents */
+	udf_allow_writing();
+	return udf_writeout_VAT();
+}
+
+
+static int
+udf_close_volume(void)
+{
+	struct part_desc       *part;
+	struct part_hdr_desc   *phd;
+	struct logvol_int_desc *lvid;
+	struct udf_logvol_info *lvinfo;
+	struct logvol_desc     *logvol;
+	uint32_t bitmap_len, bitmap_lb, bitmap_numlb;
+	int i, equal, error;
+
+	lvid = context.logvol_integrity;
+	logvol = context.logical_vol;
+	lvinfo = context.logvol_info;
+	assert(lvid);
+	assert(logvol);
+	assert(lvinfo);
+
+	/* check our highest unique id */
+	if (context.unique_id > udf_rw64(lvid->lvint_next_unique_id)) {
+		pwarn("Last unique id updated from %ld to %ld : FIXED\n",
+				udf_rw64(lvid->lvint_next_unique_id),
+				context.unique_id);
+		open_integrity = 1;
+	}
+
+	/* check file/directory counts */
+	if (context.num_files != udf_rw32(lvinfo->num_files)) {
+		pwarn("Number of files corrected from %d to %d : FIXED\n",
+				udf_rw32(lvinfo->num_files),
+				context.num_files);
+		open_integrity = 1;
+	}
+	if (context.num_directories != udf_rw32(lvinfo->num_directories)) {
+		pwarn("Number of directories corrected from %d to %d : FIXED\n",
+				udf_rw32(lvinfo->num_directories),
+				context.num_directories);
+		open_integrity = 1;
+	}
+
+	if (vat_writeout)
+		open_integrity = 1;
+
+	if (open_integrity)
+		udf_update_lvintd(UDF_INTEGRITY_OPEN);
+
+	if (context.format_flags & FORMAT_VAT)
+		return udf_close_volume_vat();
+
+	/* adjust free space accounting! */
+	for (i = 0; i < UDF_PARTITIONS; i++) {
+		part = context.partitions[i];
+		if (!part)
+			continue;
+		phd = &part->pd_part_hdr;
+		bitmap_len = udf_rw32(phd->unalloc_space_bitmap.len);
+		bitmap_lb  = udf_rw32(phd->unalloc_space_bitmap.lb_num);
+
+		if (bitmap_len == 0) {
+			error = 0;
+			continue;
+		}
+
+		equal = memcmp( recorded_part_unalloc_bits[i],
+				context.part_unalloc_bits[i],
+				bitmap_len) == 0;
+
+		if (!equal || (context.part_free[i] != recorded_part_free[i])) {
+			if (!equal)
+				pwarn("Calculated bitmap for partition %d not equal "
+				      "to recorded one : FIXED\n", i);
+			pwarn("Free space on partition %d corrected "
+			      "from %d to %d blocks : FIXED\n", i,
+			      recorded_part_free[i],
+			      context.part_free[i]);
+
+			/* write out updated free space map */
+			pwarn("Updating unallocated bitmap for partition\n");
+			if (!preen)
+				printf("Writing free space map "
+				       "for partition %d\n", i);
+			error = 0;
+			if (context.vtop_tp[i] == UDF_VTOP_TYPE_META) {
+				if (context.meta_bitmap) {
+					assert(i == context.metadata_part);
+					error = udf_process_file(
+						(union dscrptr *) context.meta_bitmap,
+						context.data_part,
+						(uint8_t **) &(context.part_unalloc_bits[i]),
+						AD_SAVE_FILE, NULL);
+				}
+			} else {
+				bitmap_numlb = udf_bytes_to_sectors(bitmap_len);
+				error = udf_write_dscr_virt(
+					(union dscrptr *) context.part_unalloc_bits[i],
+					bitmap_lb,
+					i,
+					bitmap_numlb);
+			}
+			if (error)
+				pwarn("Updating unallocated bitmap failed, "
+				      "continuing\n");
+			udf_update_lvintd(UDF_INTEGRITY_OPEN);
+		}
+	}
+
+	/* write out the logical volume integrity sequence */
+	error = udf_writeout_lvint();
+
+	return error;
+}
+
+/* --------------------------------------------------------------------- */
+
+/*
+ * Main part of file system checking.
+ *
+ * Walk the entire directory tree and check all link counts and rebuild the
+ * free space map (if present) on the go.
+ */
+
+static struct udf_fsck_node *
+udf_new_fsck_node(struct udf_fsck_node *parent, struct long_ad *loc, char *fname)
+{
+	struct udf_fsck_node *this;
+	this = calloc(1, sizeof(struct udf_fsck_node));
+	if (!this)
+		return NULL;
+
+	this->parent = parent;
+	this->fname = strdup(fname);
+	this->loc = *loc;
+	this->fsck_flags = 0;
+
+	this->link_count = 0;
+	this->found_link_count = 0;
+
+	return this;
+}
+
+
+static void
+udf_node_path_piece(char *pathname, struct udf_fsck_node *node)
+{
+	if (node->parent) {
+		udf_node_path_piece(pathname, node->parent);
+		if (node->fsck_flags & FSCK_NODE_FLAG_STREAM_DIR)
+			strcat(pathname, "");
+		else
+			strcat(pathname, "/");
+	}
+	strcat(pathname, node->fname);
+}
+
+
+static char *
+udf_node_path(struct udf_fsck_node *node)
+{
+	static char pathname[MAXPATHLEN + 10];
+
+	strcpy(pathname, "`");
+	if (node->parent)
+		udf_node_path_piece(pathname, node);
+	else
+		strcat(pathname, "/");
+	strcat(pathname, "'");
+
+	return pathname;
+}
+
+
+static void
+udf_recursive_keep(struct udf_fsck_node *node)
+{
+	while (node->parent) {
+		node = node->parent;
+		node->fsck_flags |= FSCK_NODE_FLAG_KEEP;
+	}
+}
+
+
+static int
+udf_quick_check_fids(struct udf_fsck_node *node, union dscrptr *dscr)
+{
+	struct udf_fsck_fid_context fid_context;
+	int error;
+
+	fid_context.fid_offset = 0;
+	fid_context.data_left = node->found.inf_len;
+	error = udf_process_file(dscr, context.fids_part,
+			&node->directory,
+			AD_CHECK_FIDS,
+			&fid_context);
+
+	return error;
+}
+
+
+/* read descriptor at node's location */
+static int
+udf_read_node_dscr(struct udf_fsck_node *node, union dscrptr **dscrptr)
+{
+	*dscrptr = NULL;
+	return udf_read_dscr_virt(
+			udf_rw32(node->loc.loc.lb_num),
+			udf_rw16(node->loc.loc.part_num),
+			dscrptr);
+}
+
+
+static int
+udf_extract_node_info(struct udf_fsck_node *node, union dscrptr *dscr,
+		int be_quiet)
+{
+	struct icb_tag       *icb = NULL;
+	struct file_entry    *fe  = NULL;
+	struct extfile_entry *efe = NULL;
+	int ad_type, error;
+
+	if (udf_rw16(dscr->tag.id) == TAGID_FENTRY) {
+		fe = (struct file_entry *) dscr;
+		icb = &fe->icbtag;
+		node->declared.inf_len     = udf_rw64(fe->inf_len);
+		node->declared.obj_size    = udf_rw64(fe->inf_len);
+		node->declared.logblks_rec = udf_rw64(fe->logblks_rec);
+		node->link_count           = udf_rw16(fe->link_cnt);
+		node->unique_id            = udf_rw64(fe->unique_id);
+
+/* XXX FAULT INJECTION POINT XXX */
+//if (fe->unique_id == 33) { return ENOENT;}
+
+	}
+	if (udf_rw16(dscr->tag.id) == TAGID_EXTFENTRY) {
+		efe = (struct extfile_entry *) dscr;
+		icb = &efe->icbtag;
+		node->declared.inf_len     = udf_rw64(efe->inf_len);
+		node->declared.obj_size    = udf_rw64(efe->obj_size);
+		node->declared.logblks_rec = udf_rw64(efe->logblks_rec);
+		node->link_count           = udf_rw16(efe->link_cnt);
+		node->unique_id            = udf_rw64(efe->unique_id);
+		node->streamdir_loc = efe->streamdir_icb;
+		if (node->streamdir_loc.len)
+			node->fsck_flags |= FSCK_NODE_FLAG_HAS_STREAM_DIR;
+
+/* XXX FAULT INJECTION POINT XXX */
+//if (efe->unique_id == 0x891) { return ENOENT;}
+
+	}
+
+	if (!fe && !efe) {
+//printf("NOT REFERENCING AN FE/EFE!\n");
+		return ENOENT;
+	}
+
+	if (node->unique_id >= context.unique_id)
+		context.unique_id = node->unique_id+1;
+
+	ad_type = udf_rw16(icb->flags) & UDF_ICB_TAG_FLAGS_ALLOC_MASK;
+	if ((ad_type != UDF_ICB_INTERN_ALLOC) &&
+			(ad_type != UDF_ICB_SHORT_ALLOC) &&
+			(ad_type != UDF_ICB_LONG_ALLOC)) {
+		pwarn("%s : unknown allocation type\n",
+				udf_node_path(node));
+		return EINVAL;
+	}
+
+	bzero(&node->found, sizeof(node->found));
+	error = udf_process_file(dscr, udf_rw16(node->loc.loc.part_num), NULL,
+			AD_GATHER_STATS, (void *) &node->found);
+
+	switch (icb->file_type) {
+	case UDF_ICB_FILETYPE_RANDOMACCESS :
+	case UDF_ICB_FILETYPE_BLOCKDEVICE :
+	case UDF_ICB_FILETYPE_CHARDEVICE :
+	case UDF_ICB_FILETYPE_FIFO :
+	case UDF_ICB_FILETYPE_SOCKET :
+	case UDF_ICB_FILETYPE_SYMLINK :
+	case UDF_ICB_FILETYPE_REALTIME :
+		break;
+	default:
+		/* unknown or unsupported file type, TODO clearing? */
+		free(dscr);
+		pwarn("%s : specification violation, unknown file type %d\n",
+			udf_node_path(node), icb->file_type);
+		return ENOENT;
+	case UDF_ICB_FILETYPE_STREAMDIR :
+	case UDF_ICB_FILETYPE_DIRECTORY :
+		/* read in the directory contents */
+		error = udf_readin_file(dscr, udf_rw16(node->loc.loc.part_num),
+				&node->directory, NULL);
+
+/* XXX FAULT INJECTION POINT XXX */
+//if (dscr->efe.unique_id == 109) node->directory[125] = 0xff;
+//if (dscr->efe.unique_id == 310) memset(node->directory+1024, 0, 300);
+
+		if (error && !be_quiet) {
+			pwarn("%s : directory has read errors\n",
+				udf_node_path(node));
+			if (ask(0, "Directory could be fixed or cleared. "
+				   "Wipe defective directory")) {
+				return ENOENT;
+			}
+			udf_recursive_keep(node);
+			node->fsck_flags |= FSCK_NODE_FLAG_REPAIRDIR;
+		}
+		node->fsck_flags |= FSCK_NODE_FLAG_DIRECTORY;
+		error = udf_quick_check_fids(node, dscr);
+		if (error) {
+			if (!(node->fsck_flags & FSCK_NODE_FLAG_REPAIRDIR))
+				pwarn("%s : directory file entries need repair\n",
+					udf_node_path(node));
+			udf_recursive_keep(node);
+			node->fsck_flags |= FSCK_NODE_FLAG_REPAIRDIR;
+		}
+	}
+
+/* XXX FAULT INJECTION POINT XXX */
+//if (fe->unique_id == 0) node->link_count++;
+//if (efe->unique_id == 0) node->link_count++;
+//if (efe->unique_id == 772) { node->declared.inf_len += 205; node->declared.obj_size -= 0; }
+
+	return 0;
+}
+
+
+static void
+udf_fixup_lengths_pass1(struct udf_fsck_node *node, union dscrptr *dscr)
+{
+	int64_t diff;
+
+	/* file length check */
+	diff = node->found.inf_len - node->declared.inf_len;
+	if (diff) {
+		pwarn("%s : recorded information length incorrect: "
+			"%lu instead of declared %lu\n",
+			udf_node_path(node),
+			node->found.inf_len, node->declared.inf_len);
+			node->declared.inf_len = node->found.inf_len;
+		udf_recursive_keep(node);
+		node->fsck_flags |= FSCK_NODE_FLAG_DIRTY;
+	}
+
+	/* recorded logical blocks count check */
+	diff = node->found.logblks_rec - node->declared.logblks_rec;
+	if (diff) {
+		pwarn("%s : logical blocks recorded incorrect: "
+		      "%lu instead of declared %lu, fixing\n",
+			udf_node_path(node),
+			node->found.logblks_rec, node->declared.logblks_rec);
+		node->declared.logblks_rec = node->found.logblks_rec;
+		udf_recursive_keep(node);
+		node->fsck_flags |= FSCK_NODE_FLAG_DIRTY;
+	}
+
+	/* tally object sizes for streamdirs */
+	node->found.obj_size = node->found.inf_len;
+	if (node->fsck_flags & FSCK_NODE_FLAG_STREAM_ENTRY) {
+		assert(node->parent);		/* streamdir itself */
+		if (node->parent->parent)
+			node->parent->parent->found.obj_size +=
+				node->found.inf_len;
+	}
+
+	/* check descriptor CRC length */
+	if (udf_rw16(dscr->tag.desc_crc_len) !=
+			udf_tagsize(dscr, 1) - sizeof(struct desc_tag)) {
+		pwarn("%s : node file descriptor CRC length mismatch; "
+			"%d declared, %ld expected\n",
+			udf_node_path(node), udf_rw16(dscr->tag.desc_crc_len),
+			udf_tagsize(dscr, 1) - sizeof(struct desc_tag));
+		udf_recursive_keep(node);
+		node->fsck_flags |= FSCK_NODE_FLAG_DIRTY;
+	}
+}
+
+
+static void
+udf_node_pass1_add_entry(struct udf_fsck_node *node,
+		struct fileid_desc *fid, struct dirent *dirent)
+{
+	struct udf_fsck_node *leaf_node;
+	int entry;
+
+	/* skip deleted FID entries */
+	if (fid->file_char & UDF_FILE_CHAR_DEL)
+		return;
+
+	if (udf_rw32(fid->icb.loc.lb_num) == 0) {
+		pwarn("%s : FileID entry `%s` has invalid location\n",
+				udf_node_path(node), dirent->d_name);
+		udf_recursive_keep(node);
+		if (node->parent)
+			node->parent->fsck_flags |= FSCK_NODE_FLAG_REPAIRDIR;
+		return;
+	}
+
+	/* increase parent link count */
+	if (fid->file_char & UDF_FILE_CHAR_PAR) {
+		if (node->parent)
+			node->parent->found_link_count++;
+		return;
+	}
+
+	/* lookup if we already know this node */
+	leaf_node = udf_node_lookup(&fid->icb);
+	if (leaf_node) {
+		/* got a hard link! */
+		leaf_node->found_link_count++;
+		return;
+	}
+
+	/* create new node */
+	leaf_node = udf_new_fsck_node(
+			node, &fid->icb, dirent->d_name);
+	if (node->fsck_flags & FSCK_NODE_FLAG_STREAM_DIR)
+		leaf_node->fsck_flags |= FSCK_NODE_FLAG_STREAM_ENTRY;
+
+	TAILQ_INSERT_TAIL(&fs_nodes, leaf_node, next);
+	entry = udf_calc_node_hash(&fid->icb);
+	LIST_INSERT_HEAD(&fs_nodes_hash[entry], leaf_node, next_hash);
+}
+
+
+static void
+udf_node_pass1_add_streamdir_entry(struct udf_fsck_node *node)
+{
+	struct udf_fsck_node *leaf_node;
+	int entry;
+
+	/* check for recursion */
+	if (node->fsck_flags & FSCK_NODE_FLAG_STREAM) {
+		/* recursive streams are not allowed by spec */
+		pwarn("%s : specification violation, recursive stream dir\n",
+			udf_node_path(node));
+		udf_recursive_keep(node);
+		node->fsck_flags |= FSCK_NODE_FLAG_WIPE_STREAM_DIR;
+		return;
+	}
+
+	/* lookup if we already know this node */
+	leaf_node = udf_node_lookup(&node->streamdir_loc);
+	if (leaf_node) {
+		pwarn("%s : specification violation, hardlinked streamdir\n",
+			udf_node_path(leaf_node));
+		udf_recursive_keep(node);
+		node->fsck_flags |= FSCK_NODE_FLAG_WIPE_STREAM_DIR;
+		return;
+	}
+
+	/* create new node */
+	leaf_node = udf_new_fsck_node(
+			node, &node->streamdir_loc, strdup(""));
+	leaf_node->fsck_flags |= FSCK_NODE_FLAG_STREAM_DIR;
+
+	/* streamdirs have link count 0 : ECMA 4/14.9.6 */
+	leaf_node->found_link_count--;
+
+	/* insert in to lists */
+	TAILQ_INSERT_TAIL(&fs_nodes, leaf_node, next);
+	entry = udf_calc_node_hash(&node->streamdir_loc);
+	LIST_INSERT_HEAD(&fs_nodes_hash[entry], leaf_node, next_hash);
+}
+
+
+static int
+udf_process_node_pass1(struct udf_fsck_node *node, union dscrptr *dscr)
+{
+	struct fileid_desc *fid;
+	struct dirent dirent;
+	struct charspec osta_charspec;
+	int64_t fpos, new_length, rest_len;
+	uint32_t fid_len;
+	uint8_t *bpos;
+	int isdir;
+	int error;
+
+	isdir = node->fsck_flags & FSCK_NODE_FLAG_DIRECTORY;
+
+	/* keep link count */
+	node->found_link_count++;
+
+	if (isdir) {
+		assert(node->directory);
+		udf_rebuild_fid_stream(node, &new_length);
+		node->found.inf_len = new_length;
+		rest_len = new_length;
+	}
+
+	udf_fixup_lengths_pass1(node, dscr);
+
+	/* check UniqueID */
+	if (node->parent) {
+		if (node->fsck_flags & FSCK_NODE_FLAG_STREAM) {
+
+/* XXX FAULT INJECTION POINT XXX */
+//node->unique_id = 0xdeadbeefcafe;
+
+			if (node->unique_id != node->parent->unique_id) {
+				pwarn("%s : stream file/dir UniqueID mismatch "
+				      "with parent\n",
+						udf_node_path(node));
+				/* do the work here prematurely for our siblings */
+				udf_recursive_keep(node);
+				node->unique_id = node->parent->unique_id;
+				node->fsck_flags |= FSCK_NODE_FLAG_COPY_PARENT_ID |
+					FSCK_NODE_FLAG_DIRTY;
+				assert(node->parent);
+				node->parent->fsck_flags |= FSCK_NODE_FLAG_REPAIRDIR;
+			}
+		} else if (node->unique_id < 16) {
+			pwarn("%s : file has bad UniqueID\n",
+					udf_node_path(node));
+			udf_recursive_keep(node);
+			node->fsck_flags |= FSCK_NODE_FLAG_NEW_UNIQUE_ID;
+			assert(node->parent);
+			node->parent->fsck_flags |= FSCK_NODE_FLAG_REPAIRDIR;
+		}
+	} else {
+		/* rootdir */
+		if (node->unique_id != 0) {
+			pwarn("%s : has bad UniqueID, has to be zero\n",
+					udf_node_path(node));
+			udf_recursive_keep(node);
+			node->fsck_flags |= FSCK_NODE_FLAG_REPAIRDIR;
+		}
+	}
+
+	/* add streamdir if present */
+	if (node->fsck_flags & FSCK_NODE_FLAG_HAS_STREAM_DIR)
+		udf_node_pass1_add_streamdir_entry(node);
+
+	/* add all children */
+	if (isdir) {
+		node->fsck_flags |= FSCK_NODE_FLAG_PAR_NOT_FOUND;
+		rest_len = node->found.inf_len;
+
+		/* walk trough all our FIDs in the directory stream */
+		bpos = node->directory;
+		fpos = 0;
+		while (rest_len > 0) {
+			fid = (struct fileid_desc *) bpos;
+			fid_len = udf_fidsize(fid);
+
+			/* get printable name */
+			memset(&dirent, 0, sizeof(dirent));
+			udf_osta_charset(&osta_charspec);
+			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);
+
+			/* '..' has no name, so provide one */
+			if (fid->file_char & UDF_FILE_CHAR_PAR) {
+				strcpy(dirent.d_name, "..");
+				node->fsck_flags &= ~FSCK_NODE_FLAG_PAR_NOT_FOUND;
+			}
+
+			udf_node_pass1_add_entry(node, fid, &dirent);
+
+			fpos += fid_len;
+			bpos += fid_len;
+			rest_len -= fid_len;
+		}
+	}
+
+	error = udf_process_file(dscr, udf_rw16(node->loc.loc.part_num), NULL,
+			AD_CHECK_USED, node);
+	if (error) {
+		pwarn("%s : internal error: checking for being allocated shouldn't fail\n",
+			udf_node_path(node));
+		return EINVAL;
+	}
+	/* file/directory is OK and referenced as its size won't change */
+	error = udf_process_file(dscr, udf_rw16(node->loc.loc.part_num), NULL,
+			AD_MARK_AS_USED, NULL);
+	if (error) {
+		pwarn("%s : internal error: marking allocated shouldn't fail\n",
+			udf_node_path(node));
+		return EINVAL;
+	}
+	return 0;
+}
+
+
+static void
+udf_node_pass3_repairdir(struct udf_fsck_node *node, union dscrptr *dscr)
+{
+	struct fileid_desc *fid, *last_empty_fid;
+	struct udf_fsck_node *file_node;
+	struct udf_fsck_fid_context fid_context;
+	struct dirent dirent;
+	struct charspec osta_charspec;
+	int64_t fpos, rest_len;
+	uint32_t fid_len;
+	uint8_t *bpos;
+	int parent_missing;
+	int error;
+
+	pwarn("%s : fixing up directory\n", udf_node_path(node));
+	assert(node->fsck_flags & FSCK_NODE_FLAG_DIRECTORY);
+
+	rest_len = node->found.inf_len;
+
+	udf_osta_charset(&osta_charspec);
+	bpos = node->directory;
+	fpos = 0;
+	parent_missing = (node->fsck_flags & FSCK_NODE_FLAG_PAR_NOT_FOUND)? 1:0;
+
+	last_empty_fid = NULL;
+	while (rest_len > 0) {
+		fid = (struct fileid_desc *) bpos;
+		fid_len = udf_fidsize(fid);
+
+		/* get printable name */
+		memset(&dirent, 0, sizeof(dirent));
+		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);
+
+		/* '..' has no name, so provide one */
+		if (fid->file_char & UDF_FILE_CHAR_PAR) {
+			strcpy(dirent.d_name, "..");
+		}
+
+		/* only look up when not deleted */
+		file_node = NULL;
+		if ((fid->file_char & UDF_FILE_CHAR_DEL) == 0)
+			file_node = udf_node_lookup(&fid->icb);
+
+		/* if found */
+		if (file_node) {
+			/* delete files which couldn't be found */
+			if (file_node && (file_node->fsck_flags & FSCK_NODE_FLAG_NOTFOUND)) {
+				fid->file_char |= UDF_FILE_CHAR_DEL;
+				memset(&fid->icb, 0, sizeof(struct long_ad));
+			}
+
+			/* fix up FID UniqueID errors */
+			if (fid->icb.longad_uniqueid != file_node->unique_id)
+				fid->icb.longad_uniqueid = udf_rw64(file_node->unique_id);
+		} else {
+			/* just mark it deleted if not found */
+			fid->file_char |= UDF_FILE_CHAR_DEL;
+		}
+
+		if (fid->file_char & UDF_FILE_CHAR_DEL) {
+			memset(&fid->icb, 0 , sizeof(struct long_ad));
+			if (context.dscrver == 2) {
+				uint8_t *cpos;
+				/* compression IDs are preserved */
+				cpos = (fid->data + udf_rw16(fid->l_iu));
+				if (*cpos == 254)
+					*cpos = 8;
+				if (*cpos == 255)
+					*cpos = 16;
+			}
+		}
+
+		fpos += fid_len;
+		bpos += fid_len;
+		rest_len -= fid_len;
+		assert(rest_len >= 0);
+	}
+	if (parent_missing) {
+		/* this should be valid or we're in LALA land */
+		assert(last_empty_fid);
+		pwarn("%s : implementation limit, can't fix up missing parent node yet!\n",
+			udf_node_path(node));
+	}
+
+	node->fsck_flags |= FSCK_NODE_FLAG_DIRTY;
+
+	fid_context.fid_offset = 0;
+	fid_context.data_left = node->found.inf_len;
+	error = udf_process_file(dscr, context.fids_part,
+			&node->directory,
+			AD_ADJUST_FIDS | AD_SAVE_FILE,
+			&fid_context);
+	if (error)
+		pwarn("Failed to write out directory!\n");
+}
+
+
+static void
+udf_node_pass3_writeout_update(struct udf_fsck_node *node, union dscrptr *dscr)
+{
+	struct file_entry    *fe  = NULL;
+	struct extfile_entry *efe = NULL;
+	int error;
+
+	vat_writeout = 1;
+	if (udf_rw16(dscr->tag.id) == TAGID_FENTRY) {
+		fe = (struct file_entry *) dscr;
+		fe->inf_len      = udf_rw64(node->declared.inf_len);
+		fe->logblks_rec  = udf_rw64(node->declared.logblks_rec);
+		fe->link_cnt     = udf_rw16(node->link_count);
+		fe->unique_id    = udf_rw64(node->unique_id);
+	}
+	if (udf_rw16(dscr->tag.id) == TAGID_EXTFENTRY) {
+		efe = (struct extfile_entry *) dscr;
+		efe->inf_len     = udf_rw64(node->declared.inf_len);
+		efe->obj_size    = udf_rw64(node->declared.obj_size);
+		efe->logblks_rec = udf_rw64(node->declared.logblks_rec);
+		efe->link_cnt    = udf_rw16(node->link_count);
+		efe->unique_id   = udf_rw64(node->unique_id);
+		/* streamdir directly cleared in dscr */
+	}
+
+	/* fixup CRC length (if needed) */
+	dscr->tag.desc_crc_len = udf_tagsize(dscr, 1) - sizeof(struct desc_tag);
+
+	pwarn("%s : updating node\n", udf_node_path(node));
+	error = udf_write_dscr_virt(dscr, udf_rw32(node->loc.loc.lb_num),
+			udf_rw16(node->loc.loc.part_num), 1);
+	udf_shadow_VAT_in_use(&node->loc);
+	if (error)
+		pwarn("%s failed\n", __func__);
+}
+
+
+static void
+udf_create_new_space_bitmaps_and_reset_freespace(void)
+{
+	struct space_bitmap_desc *sbd, *new_sbd;
+	struct part_desc *part;
+	struct part_hdr_desc *phd;
+	uint32_t bitmap_len, bitmap_lb, bitmap_numlb;
+	uint32_t cnt;
+	int i, p, dscr_size;
+	int error;
+
+	/* copy recorded freespace info and clear counters */
+	for (i = 0; i < UDF_PARTITIONS; i++) {
+		recorded_part_free[i] = context.part_free[i];
+		context.part_free[i]  = context.part_size[i];
+	}
+
+	/* clone existing bitmaps */
+	for (i = 0; i < UDF_PARTITIONS; i++) {
+		sbd = context.part_unalloc_bits[i];
+		recorded_part_unalloc_bits[i] = sbd;
+		if (sbd == NULL)
+			continue;
+		dscr_size = udf_tagsize((union dscrptr *) sbd,
+				context.sector_size);
+		new_sbd = calloc(1, dscr_size);
+		memcpy(new_sbd, sbd, sizeof(struct space_bitmap_desc)-1);
+
+		/* fill space with 0xff to indicate free */
+		for (cnt = 0; cnt < udf_rw32(sbd->num_bytes); cnt++)
+			new_sbd->data[cnt] = 0xff;
+
+		context.part_unalloc_bits[i] = new_sbd;
+	}
+
+	/* allocate the space bitmaps themselves (normally one) */
+	for (i = 0; i < UDF_PARTITIONS; i++) {
+		part = context.partitions[i];
+		if (!part)
+			continue;
+
+		phd = &part->pd_part_hdr;
+		bitmap_len = udf_rw32(phd->unalloc_space_bitmap.len);
+		bitmap_lb  = udf_rw32(phd->unalloc_space_bitmap.lb_num);
+		if (bitmap_len == 0)
+			continue;
+
+		bitmap_numlb = udf_bytes_to_sectors(bitmap_len);
+		sbd = context.part_unalloc_bits[i];
+		assert(sbd);
+
+		udf_mark_allocated(bitmap_lb, context.vtop[i], bitmap_numlb);
+	}
+
+	/* special case for metadata partition */
+	if (context.format_flags & FORMAT_META) {
+		i = context.metadata_part;
+		p = context.vtop[i];
+		assert(context.vtop_tp[i] == UDF_VTOP_TYPE_META);
+		error = udf_process_file((union dscrptr *) context.meta_file,
+			p, NULL, AD_MARK_AS_USED, NULL);
+		error = udf_process_file((union dscrptr *) context.meta_mirror,
+			p, NULL, AD_MARK_AS_USED, NULL);
+		if (context.meta_bitmap) {
+			error = udf_process_file(
+				(union dscrptr *) context.meta_bitmap,
+				p, NULL, AD_MARK_AS_USED, NULL);
+			assert(error == 0);
+		}
+	}
+
+	/* mark fsd allocation ! */
+	udf_mark_allocated(udf_rw32(context.fileset_desc->tag.tag_loc),
+		context.metadata_part, 1);
+}
+
+
+static void
+udf_shadow_VAT_in_use(struct long_ad *loc)
+{
+	uint32_t i;
+	uint8_t *vat_pos, *shadow_vat_pos;
+
+	if (context.vtop_tp[context.metadata_part] != UDF_VTOP_TYPE_VIRT)
+		return;
+
+	i = udf_rw32(loc->loc.lb_num);
+	vat_pos = context.vat_contents + context.vat_start + i*4;
+	shadow_vat_pos = shadow_vat_contents + context.vat_start + i*4;
+	/* keeping endian */
+	*(uint32_t *) shadow_vat_pos = *(uint32_t *) vat_pos;
+}
+
+
+static void
+udf_create_shadow_VAT(void)
+{
+	struct long_ad fsd_loc;
+	uint32_t  vat_entries, i;
+	uint8_t *vat_pos;
+
+	if (context.vtop_tp[context.metadata_part] != UDF_VTOP_TYPE_VIRT)
+		return;
+
+	shadow_vat_contents = calloc(1, context.vat_allocated);
+	assert(shadow_vat_contents);
+	memcpy(shadow_vat_contents, context.vat_contents, context.vat_size);
+
+	vat_entries = (context.vat_size - context.vat_start)/4;
+	for (i = 0; i < vat_entries; i++) {
+		vat_pos = shadow_vat_contents + context.vat_start + i*4;
+		*(uint32_t *) vat_pos = udf_rw32(0xffffffff);
+	}
+
+	/*
+	 * Record our FSD in this shadow VAT since its the only one outside
+	 * the nodes.
+	 */
+	memset(&fsd_loc, 0, sizeof(struct long_ad));
+	fsd_loc.loc.lb_num = context.fileset_desc->tag.tag_loc;
+	udf_shadow_VAT_in_use(&fsd_loc);
+}
+
+
+static void
+udf_check_shadow_VAT(void)
+{
+	uint32_t vat_entries, i;
+	uint8_t *vat_pos, *shadow_vat_pos;
+	int difference = 0;
+
+	if (context.vtop_tp[context.metadata_part] != UDF_VTOP_TYPE_VIRT)
+		return;
+
+	vat_entries = (context.vat_size - context.vat_start)/4;
+	for (i = 0; i < vat_entries; i++) {
+		vat_pos = context.vat_contents + context.vat_start + i*4;
+		shadow_vat_pos = shadow_vat_contents + context.vat_start + i*4;
+		if (*(uint32_t *) vat_pos != *(uint32_t *) shadow_vat_pos) {
+			difference++;
+		}
+	}
+	memcpy(context.vat_contents, shadow_vat_contents, context.vat_size);
+	if (difference) {
+		if (!preen)
+			printf("\t\t");
+		pwarn("%d unused VAT entries cleaned\n", difference);
+		vat_writeout = 1;
+	}
+}
+
+
+static int
+udf_check_directory_tree(void)
+{
+	union dscrptr *dscr;
+	struct udf_fsck_node *root_node, *sys_stream_node;
+	struct udf_fsck_node *cur_node, *next_node;
+	struct long_ad root_icb, sys_stream_icb;
+	bool dont_repair;
+	int entry, error;
+
+	assert(TAILQ_EMPTY(&fs_nodes));
+
+	/* (re)init queues and hash lists */
+	TAILQ_INIT(&fs_nodes);
+	TAILQ_INIT(&fsck_overlaps);
+	for (int i = 0; i < HASH_HASHSIZE; i++)
+		LIST_INIT(&fs_nodes_hash[i]);
+
+	/* create a new empty copy of the space bitmaps */
+	udf_create_new_space_bitmaps_and_reset_freespace();
+	udf_create_shadow_VAT();
+
+	/* start from the root */
+	root_icb       = context.fileset_desc->rootdir_icb;
+	sys_stream_icb = context.fileset_desc->streamdir_icb;
+
+	root_node = udf_new_fsck_node(NULL, &root_icb, strdup(""));
+	assert(root_node);
+	TAILQ_INSERT_TAIL(&fs_nodes, root_node, next);
+	entry = udf_calc_node_hash(&root_node->loc);
+	LIST_INSERT_HEAD(&fs_nodes_hash[entry], root_node, next_hash);
+
+	sys_stream_node = NULL;
+	if (sys_stream_icb.len) {
+		sys_stream_node = udf_new_fsck_node(NULL, &sys_stream_icb, strdup("#"));
+		assert(sys_stream_node);
+		sys_stream_node->fsck_flags |= FSCK_NODE_FLAG_STREAM_DIR;
+
+		TAILQ_INSERT_TAIL(&fs_nodes, sys_stream_node, next);
+		entry = udf_calc_node_hash(&sys_stream_node->loc);
+		LIST_INSERT_HEAD(&fs_nodes_hash[entry], sys_stream_node, next_hash);
+	}
+
+	/* pass 1 */
+	if (!preen)
+		printf("\tPass 1, reading in directory trees\n");
+
+	context.unique_id = MAX(0x10, context.unique_id);
+	TAILQ_FOREACH(cur_node, &fs_nodes, next) {
+		/* read in node */
+		error = udf_read_node_dscr(cur_node, &dscr);
+		if (!error)
+			error = udf_extract_node_info(cur_node, dscr, 0);
+		if (error) {
+			pwarn("%s : invalid reference or bad descriptor, DELETING\n",
+				udf_node_path(cur_node));
+			udf_recursive_keep(cur_node);
+			cur_node->fsck_flags |= FSCK_NODE_FLAG_NOTFOUND;
+			if (cur_node->parent) {
+				if (cur_node->fsck_flags & FSCK_NODE_FLAG_STREAM_DIR)
+					cur_node->parent->fsck_flags |=
+						FSCK_NODE_FLAG_WIPE_STREAM_DIR;
+				else
+					cur_node->parent->fsck_flags |=
+						FSCK_NODE_FLAG_REPAIRDIR;
+				;
+			}
+			free(dscr);
+			continue;
+		}
+
+		if (print_info) {
+			pwarn("Processing %s\n", udf_node_path(cur_node));
+			print_info = 0;
+		}
+
+		/* directory found in stream directory? */
+		if (cur_node->parent &&
+			(cur_node->parent->fsck_flags & FSCK_NODE_FLAG_STREAM_DIR) &&
+			(cur_node->fsck_flags & FSCK_NODE_FLAG_DIRECTORY))
+		{
+			pwarn("%s : specification violation, directory in stream directory\n",
+				udf_node_path(cur_node));
+			if (ask(0, "Clear directory")) {
+				udf_recursive_keep(cur_node);
+				cur_node->fsck_flags |= FSCK_NODE_FLAG_NOTFOUND;
+				cur_node->parent->fsck_flags |=
+					FSCK_NODE_FLAG_REPAIRDIR;
+				continue;
+			}
+		}
+		error = udf_process_node_pass1(cur_node, dscr);
+		free(dscr);
+
+		if (error)
+			return error;
+	}
+
+	/* pass 1b, if there is overlap, find matching pairs */
+	dont_repair = false;
+	if (!TAILQ_EMPTY(&fsck_overlaps)) {
+		struct udf_fsck_overlap *overlap;
+
+		dont_repair = true;
+		pwarn("*** Overlaps detected! rescanning tree for matching pairs ***\n");
+		TAILQ_FOREACH(cur_node, &fs_nodes, next) {
+			if (cur_node->fsck_flags & FSCK_NODE_FLAG_NOTFOUND)
+				continue;
+
+			error = udf_read_node_dscr(cur_node, &dscr);
+			/* should not fail differently */
+
+			if (print_info) {
+				pwarn("Processing %s\n", udf_node_path(cur_node));
+				print_info = 0;
+			}
+
+			error = udf_process_file(
+					dscr,
+					udf_rw16(cur_node->loc.loc.part_num),
+					NULL,
+					AD_FIND_OVERLAP_PAIR,
+					(void *) cur_node);
+			/* shouldn't fail */
+
+			free(dscr);
+		}
+		TAILQ_FOREACH(overlap, &fsck_overlaps, next) {
+			pwarn("%s :overlaps with %s\n",
+				udf_node_path(overlap->node),
+				udf_node_path(overlap->node2));
+		}
+		if (!preen)
+			printf("\n");
+		pwarn("*** The following files/directories need to be copied/evacuated:\n");
+		TAILQ_FOREACH(cur_node, &fs_nodes, next) {
+			if (cur_node->fsck_flags & FSCK_NODE_FLAG_OVERLAP) {
+				pwarn("%s : found OVERLAP, evacuate\n",
+					udf_node_path(cur_node));
+			}
+		}
+	}
+	if (dont_repair) {
+		if (!preen)
+			printf("\n");
+		pwarn("*** Skipping further repair, only updating free space map if needed\n");
+		pwarn("*** After deep copying and/or evacuation of these files/directories,\n");
+		pwarn("*** remove files/directories and re-run fsck_udf\n");
+		error = udf_prepare_writing();
+		if (error)
+			return error;
+
+		udf_update_lvintd(UDF_INTEGRITY_OPEN);
+		return 0;
+	}
+
+	/* pass 2a, checking link counts, object sizes and count files/dirs */
+	if (!preen)
+		printf("\n\tPass 2, checking link counts, object sizes, stats and cleaning up\n");
+
+	TAILQ_FOREACH_SAFE(cur_node, &fs_nodes, next, next_node) {
+		/* not sane to process files/directories that are not found */
+		if (cur_node->fsck_flags & FSCK_NODE_FLAG_NOTFOUND)
+			continue;
+
+		/* shadow VAT */
+		udf_shadow_VAT_in_use(&cur_node->loc);
+
+		/* link counts */
+		if (cur_node->found_link_count != cur_node->link_count) {
+			pwarn("%s : link count incorrect; "
+			      "%u instead of declared %u : FIXED\n",
+				udf_node_path(cur_node),
+				cur_node->found_link_count, cur_node->link_count);
+			cur_node->link_count = cur_node->found_link_count;
+			udf_recursive_keep(cur_node);
+			cur_node->fsck_flags |= FSCK_NODE_FLAG_DIRTY;
+		}
+
+		/* object sizes */
+		if (cur_node->declared.obj_size != cur_node->found.obj_size) {
+			pwarn("%s : recorded object size incorrect; "
+			      "%lu instead of declared %lu\n",
+				udf_node_path(cur_node),
+				cur_node->found.obj_size, cur_node->declared.obj_size);
+			cur_node->declared.obj_size = cur_node->found.obj_size;
+			udf_recursive_keep(cur_node);
+			cur_node->fsck_flags |= FSCK_NODE_FLAG_DIRTY;
+		}
+
+		/* XXX TODO XXX times */
+		/* XXX TODO XXX extended attributes location for UDF < 1.50 */
+
+		/* validity of UniqueID check */
+		if (cur_node->parent) {
+			if (cur_node->fsck_flags & FSCK_NODE_FLAG_NEW_UNIQUE_ID) {
+				pwarn("%s : assigning new UniqueID\n",
+					udf_node_path(cur_node));
+				cur_node->unique_id = udf_rw64(context.unique_id);
+				udf_advance_uniqueid();
+				udf_recursive_keep(cur_node);
+				cur_node->fsck_flags |= FSCK_NODE_FLAG_DIRTY;
+				if (cur_node->fsck_flags & FSCK_NODE_FLAG_DIRECTORY)
+					cur_node->fsck_flags |= FSCK_NODE_FLAG_REPAIRDIR;
+				cur_node->parent->fsck_flags |= FSCK_NODE_FLAG_REPAIRDIR;
+			}
+			if (cur_node->fsck_flags & FSCK_NODE_FLAG_COPY_PARENT_ID) {
+				/* work already done but make note to operator */
+				pwarn("%s : fixing stream UniqueID to match parent\n",
+					udf_node_path(cur_node));
+			}
+		} else {
+			if (cur_node->unique_id != 0) {
+				pwarn("%s : bad UniqueID, zeroing\n",
+						udf_node_path(cur_node));
+				cur_node->unique_id = 0;
+				cur_node->fsck_flags |=
+					FSCK_NODE_FLAG_DIRTY | FSCK_NODE_FLAG_REPAIRDIR;
+			}
+		}
+
+		/* keep nodes in a repairing dir */
+		if (cur_node->parent)
+			if (cur_node->parent->fsck_flags & FSCK_NODE_FLAG_REPAIRDIR)
+				cur_node->fsck_flags |= FSCK_NODE_FLAG_KEEP;
+
+		/* stream directories and files in it are not included */
+		if (!(cur_node->fsck_flags & FSCK_NODE_FLAG_STREAM)) {
+			/* files / directories counting */
+			int link_count = cur_node->found_link_count;
+
+			/* stream directories don't count as link ECMA 4/14.9.6 */
+			if (cur_node->fsck_flags & FSCK_NODE_FLAG_HAS_STREAM_DIR)
+				link_count--;
+
+			if (cur_node->fsck_flags & FSCK_NODE_FLAG_DIRECTORY)
+				context.num_directories++;
+			else 
+				context.num_files += link_count;
+			;
+		}
+	}
+
+	/* pass 2b, cleaning */
+	open_integrity = 0;
+	TAILQ_FOREACH_SAFE(cur_node, &fs_nodes, next, next_node) {
+		/* can we remove the node? (to save memory) */
+		if (FSCK_NODE_FLAG_OK(cur_node->fsck_flags)) {
+			TAILQ_REMOVE(&fs_nodes, cur_node, next);
+			LIST_REMOVE(cur_node, next_hash);
+			free(cur_node->directory);
+			bzero(cur_node, sizeof(struct udf_fsck_node));
+			free(cur_node);
+		} else {
+			/* else keep erroring node */
+			open_integrity = 1;
+		}
+	}
+
+	if (!preen)
+		printf("\n\tPreparing disc for writing\n");
+	error = udf_prepare_writing();
+	if (error)
+		return error;
+
+	if (open_integrity)
+		udf_update_lvintd(UDF_INTEGRITY_OPEN);
+
+	/* pass 3 */
+	if (!preen)
+		printf("\n\tPass 3, fix errors\n");
+
+	TAILQ_FOREACH_SAFE(cur_node, &fs_nodes, next, next_node) {
+		/* not sane to process files/directories that are not found */
+		if (cur_node->fsck_flags & FSCK_NODE_FLAG_NOTFOUND)
+			continue;
+
+		/* only interested in bad nodes */
+		if (FSCK_NODE_FLAG_OK(cur_node->fsck_flags))
+			continue;
+
+		error = udf_read_node_dscr(cur_node, &dscr);
+		/* should not fail differently */
+
+		/* repair directories */
+		if (cur_node->fsck_flags & FSCK_NODE_FLAG_REPAIRDIR)
+			udf_node_pass3_repairdir(cur_node, dscr);
+
+		/* remove invalid stream directories */
+		if (cur_node->fsck_flags & FSCK_NODE_FLAG_WIPE_STREAM_DIR) {
+			assert(udf_rw16(dscr->tag.id) == TAGID_EXTFENTRY);
+			bzero(&dscr->efe.streamdir_icb, sizeof(struct long_ad));
+			cur_node->fsck_flags |= FSCK_NODE_FLAG_DIRTY;
+		}
+
+		if (cur_node->fsck_flags & FSCK_NODE_FLAG_DIRTY)
+			udf_node_pass3_writeout_update(cur_node, dscr);
+		free(dscr);
+	}
+	udf_check_shadow_VAT();
+
+	return 0;
+}
+
+
+static void
+udf_cleanup_after_check(void)
+{
+	struct udf_fsck_node *cur_node, *next_node;
+
+	/* XXX yes, there are some small memory leaks here */
+
+	/* clean old node info from previous checks */
+	TAILQ_FOREACH_SAFE(cur_node, &fs_nodes, next, next_node) {
+		TAILQ_REMOVE(&fs_nodes, cur_node, next);
+		LIST_REMOVE(cur_node, next_hash);
+		free(cur_node->directory);
+		free(cur_node);
+	}
+
+	/* free partition related info */
+	for (int i = 0; i < UDF_PARTITIONS; i++) {
+		free(context.partitions[i]);
+		free(context.part_unalloc_bits[i]);
+		free(context.part_freed_bits[i]);
+	}
+
+	/* only free potentional big blobs */
+	free(context.vat_contents);
+	free(context.lvint_history);
+
+	free(shadow_vat_contents);
+	shadow_vat_contents = NULL;
+}
+
+
+static int
+checkfilesys(char *given_dev)
+{
+	struct mmc_trackinfo ti;
+	int open_flags;
+	int error;
+
+	udf_init_create_context();
+	context.app_name         = "*NetBSD UDF";
+	context.app_version_main = APP_VERSION_MAIN;
+	context.app_version_sub  = APP_VERSION_SUB;
+	context.impl_name        = IMPL_NAME;
+
+	emul_mmc_profile  =  -1;	/* invalid->no emulation	*/
+	emul_packetsize   =   1;	/* reasonable default		*/
+	emul_sectorsize   = 512;	/* minimum allowed sector size	*/
+	emul_size	  =   0;	/* empty			*/
+
+	if (!preen)
+		pwarn("** Checking UDF file system on %s\n", given_dev);
+
+	/* reset sticky flags */
+	rdonly = rdonly_flag;
+	undo_opening_session = 0;	/* trying to undo opening of last crippled session */
+	vat_writeout = 0;		/* to write out the VAT anyway */
+
+	/* open disc device or emulated file */
+	open_flags = rdonly ? O_RDONLY : O_RDWR;
+	if (udf_opendisc(given_dev, open_flags)) {
+		udf_closedisc();
+		warnx("can't open %s", given_dev);
+		return FSCK_EXIT_CHECK_FAILED;
+	}
+
+	if (!preen)
+		pwarn("** Phase 1 - discovering format from disc\n\n");
+
+	/* check if it is an empty disc or no disc in present */
+	ti.tracknr = mmc_discinfo.first_track;
+	error = udf_update_trackinfo(&ti);
+	if (error || (ti.flags & MMC_TRACKINFO_BLANK)) {
+		/* no use erroring out */
+		pwarn("Empty disc\n");
+		return FSCK_EXIT_OK;
+	}
+
+	context.format_flags = 0;
+	if (mmc_discinfo.mmc_cur & MMC_CAP_SEQUENTIAL)
+		context.format_flags |= FORMAT_SEQUENTIAL;
+
+	if ((context.format_flags & FORMAT_SEQUENTIAL) &&
+		    ((mmc_discinfo.disc_state == MMC_STATE_CLOSED) ||
+		     (mmc_discinfo.disc_state == MMC_STATE_FULL))) {
+		pwarn("Disc is closed or full, can't modify disc\n");
+		rdonly = 1;
+	}
+
+	if (target_session) {
+		context.create_new_session = 1;
+		if (target_session < 0)
+			target_session += mmc_discinfo.num_sessions;
+	} else {
+		target_session = mmc_discinfo.num_sessions;
+		if (mmc_discinfo.last_session_state == MMC_STATE_EMPTY)
+			target_session--;
+	}
+
+	error = udf_get_anchors();
+	if (error) {
+		udf_closedisc();
+		pwarn("Failed to retrieve anchors; can't check file system\n");
+		return FSCK_EXIT_CHECK_FAILED;
+	}
+
+	udf_check_vrs9660();
+
+	/* get both VRS areas */
+	error = udf_check_VDS_areas();
+	if (error) {
+		udf_closedisc();
+		pwarn("Failure reading volume descriptors, disc might be toast\n");
+		return FSCK_EXIT_CHECK_FAILED;
+	}
+
+	if (udf_rw32(context.logvol_integrity->integrity_type) ==
+		UDF_INTEGRITY_CLOSED) {
+		if (!force) {
+			pwarn("** File system is clean; not checking\n");
+			return FSCK_EXIT_OK;
+		}
+		pwarn("** File system is already clean\n");
+		if (!preen)
+			pwarn("\n");
+	} else {
+		pwarn("** File system not closed properly\n");
+		if (!preen)
+			printf("\n");
+	}
+
+	/*
+	 * Only now read in free/unallocated space bitmap. If it reads in fine
+	 * it doesn't mean its contents is valid though. Sets partition
+	 * lengths too.
+	 */
+	error = udf_readin_partitions_free_space();
+	if (error) {
+		pwarn("Error during free space bitmap reading\n");
+		udf_update_lvintd(UDF_INTEGRITY_OPEN);
+	}
+
+	if (!preen)
+		pwarn("** Phase 2 - walking directory tree\n");
+
+	udf_suspend_writing();
+	error = udf_check_directory_tree();
+	if (error) {
+		if ((!rdonly) && ask(0, "Write out modifications made until now"))
+			udf_allow_writing();
+		else
+			pwarn("** Aborting repair, not modifying disc\n");
+		udf_closedisc();
+		return FSCK_EXIT_CHECK_FAILED;
+	}
+
+	if (!preen)
+		pwarn("\n** Phase 3 - closing volume if needed\n\n");
+
+/* XXX FAULT INJECTION POINT XXX */
+//udf_update_lvintd(UDF_INTEGRITY_OPEN);
+
+	if (error && rdonly) {
+		pwarn("** Aborting repair, nothing written, disc marked read-only\n");
+	} else {
+		error = udf_close_volume();
+	}
+
+	udf_closedisc();
+
+	if (error)
+		return FSCK_EXIT_CHECK_FAILED;
+	return FSCK_EXIT_OK;
+}
+
+
+static void
+usage(void)
+{
+    	(void)fprintf(stderr, "Usage: %s [-psSynfH] filesystem ... \n",
+	    getprogname());
+	exit(FSCK_EXIT_USAGE);
+}
+
+
+static void
+got_siginfo(int signo)
+{
+	print_info = 1;
+}
+
+
+int
+main(int argc, char **argv)
+{
+	int ret = FSCK_EXIT_OK, erg;
+	int ch;
+
+	while ((ch = getopt(argc, argv, "ps:SynfH")) != -1) {
+		switch (ch) {
+		case 'H':
+			heuristics = 1;
+			break;
+		case 'f':
+			force = 1;
+			break;
+		case 'n':
+			rdonly_flag = alwaysno = 1;
+			alwaysyes = preen = 0;
+			break;
+		case 'y':
+			alwaysyes = 1;
+			alwaysno = preen = 0;
+			break;
+		case 'p':
+			/* small automatic repairs */
+			preen = 1;
+			alwaysyes = alwaysno = 0;
+			break;
+		case 's':
+			/* session number or relative session */
+			target_session = atoi(optarg);
+			break;
+		case 'S':		/* Search for older VATs */
+			search_older_vat = 1;
+			break;
+
+		default:
+			usage();
+			break;
+		}
+	}
+	argc -= optind;
+	argv += optind;
+
+	if (!argc)
+		usage();
+
+	/* TODO SIGINT and SIGQUIT catchers */
+#if 0
+	if (signal(SIGINT, SIG_IGN) != SIG_IGN)
+		(void) signal(SIGINT, catch);
+	if (preen)
+		(void) signal(SIGQUIT, catch);
+#endif
+
+	signal(SIGINFO, got_siginfo);
+
+	while (--argc >= 0) {
+		setcdevname(*argv, preen);
+		erg = checkfilesys(*argv++);
+		if (erg > ret)
+			ret = erg;
+		if (!preen)
+			printf("\n");
+		udf_cleanup_after_check();
+	}
+
+	return ret;
+}
+
+
+/*VARARGS*/
+static int
+ask(int def, const char *fmt, ...)
+{
+	va_list ap;
+
+	char prompt[256];
+	int c;
+
+	va_start(ap, fmt);
+	vsnprintf(prompt, sizeof(prompt), fmt, ap);
+	va_end(ap);
+	if (alwaysyes || rdonly) {
+		pwarn("%s? %s\n", prompt, rdonly ? "no" : "yes");
+		return !rdonly;
+	}
+	if (preen) {
+		pwarn("%s? %s : (default)\n", prompt, def ? "yes" : "no");
+		return def;
+	}
+
+	do {
+		pwarn("%s? [yn] ", prompt);
+		fflush(stdout);
+		c = getchar();
+		while (c != '\n' && getchar() != '\n')
+			if (feof(stdin))
+				return 0;
+	} while (c != 'y' && c != 'Y' && c != 'n' && c != 'N');
+	return c == 'y' || c == 'Y';
+}
+
+
+/*VARARGS*/
+static int
+ask_noauto(int def, const char *fmt, ...)
+{
+	va_list ap;
+
+	char prompt[256];
+	int c;
+
+	va_start(ap, fmt);
+	vsnprintf(prompt, sizeof(prompt), fmt, ap);
+	va_end(ap);
+#if 0
+	if (preen) {
+		pwarn("%s? %s : (default)\n", prompt, def ? "yes" : "no");
+		return def;
+	}
+#endif
+
+	do {
+		pwarn("%s? [yn] ", prompt);
+		fflush(stdout);
+		c = getchar();
+		while (c != '\n' && getchar() != '\n')
+			if (feof(stdin))
+				return 0;
+	} while (c != 'y' && c != 'Y' && c != 'n' && c != 'N');
+	return c == 'y' || c == 'Y';
+}

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