Adding upstream version 1.2.0.upstream/1.2.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1681 insertions, 0 deletions

diff --git a/fsck/fsck.c b/fsck/fsck.c
new file mode 100644
index 0000000..219d723
--- /dev/null
+++ b/fsck/fsck.c
@@ -0,0 +1,1681 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *   Copyright (C) 2019 Namjae Jeon <linkinjeon@kernel.org>
+ *   Copyright (C) 2020 Hyunchul Lee <hyc.lee@gmail.com>
+ */
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <getopt.h>
+#include <inttypes.h>
+#include <string.h>
+#include <errno.h>
+#include <locale.h>
+
+#include "exfat_ondisk.h"
+#include "libexfat.h"
+#include "repair.h"
+#include "exfat_fs.h"
+#include "exfat_dir.h"
+#include "fsck.h"
+
+struct fsck_user_input {
+	struct exfat_user_input		ei;
+	enum fsck_ui_options		options;
+};
+
+#define EXFAT_MAX_UPCASE_CHARS	0x10000
+
+#define FSCK_EXIT_NO_ERRORS		0x00
+#define FSCK_EXIT_CORRECTED		0x01
+#define FSCK_EXIT_NEED_REBOOT		0x02
+#define FSCK_EXIT_ERRORS_LEFT		0x04
+#define FSCK_EXIT_OPERATION_ERROR	0x08
+#define FSCK_EXIT_SYNTAX_ERROR		0x10
+#define FSCK_EXIT_USER_CANCEL		0x20
+#define FSCK_EXIT_LIBRARY_ERROR		0x80
+
+struct exfat_stat {
+	long		dir_count;
+	long		file_count;
+	long		error_count;
+	long		fixed_count;
+};
+
+struct exfat_fsck exfat_fsck;
+struct exfat_stat exfat_stat;
+struct path_resolve_ctx path_resolve_ctx;
+
+static struct option opts[] = {
+	{"repair",	no_argument,	NULL,	'r' },
+	{"repair-yes",	no_argument,	NULL,	'y' },
+	{"repair-no",	no_argument,	NULL,	'n' },
+	{"repair-auto",	no_argument,	NULL,	'p' },
+	{"rescue",	no_argument,	NULL,	's' },
+	{"version",	no_argument,	NULL,	'V' },
+	{"verbose",	no_argument,	NULL,	'v' },
+	{"help",	no_argument,	NULL,	'h' },
+	{"?",		no_argument,	NULL,	'?' },
+	{"ignore-bad-fs",	no_argument,	NULL,	'b' },
+	{NULL,		0,		NULL,	 0  }
+};
+
+static void usage(char *name)
+{
+	fprintf(stderr, "Usage: %s\n", name);
+	fprintf(stderr, "\t-r | --repair        Repair interactively\n");
+	fprintf(stderr, "\t-y | --repair-yes    Repair without ask\n");
+	fprintf(stderr, "\t-n | --repair-no     No repair\n");
+	fprintf(stderr, "\t-p | --repair-auto   Repair automatically\n");
+	fprintf(stderr, "\t-a                   Repair automatically\n");
+	fprintf(stderr, "\t-b | --ignore-bad-fs Try to recover even if exfat is not found\n");
+	fprintf(stderr, "\t-s | --rescue        Assign orphaned clusters to files\n");
+	fprintf(stderr, "\t-V | --version       Show version\n");
+	fprintf(stderr, "\t-v | --verbose       Print debug\n");
+	fprintf(stderr, "\t-h | --help          Show help\n");
+
+	exit(FSCK_EXIT_SYNTAX_ERROR);
+}
+
+#define fsck_err(parent, inode, fmt, ...)		\
+({							\
+		exfat_resolve_path_parent(&path_resolve_ctx,	\
+			parent, inode);			\
+		exfat_err("ERROR: %s: " fmt,		\
+			path_resolve_ctx.local_path,	\
+			##__VA_ARGS__);			\
+})
+
+#define repair_file_ask(iter, inode, code, fmt, ...)	\
+({							\
+		if (inode)						\
+			exfat_resolve_path_parent(&path_resolve_ctx,	\
+					    (iter)->parent, inode);	\
+		else							\
+			exfat_resolve_path(&path_resolve_ctx,		\
+				     (iter)->parent);			\
+		exfat_repair_ask(&exfat_fsck, code,			\
+				 "ERROR: %s: " fmt " at %#" PRIx64,	\
+				 path_resolve_ctx.local_path,		\
+				 ##__VA_ARGS__,				\
+				 exfat_de_iter_device_offset(iter));	\
+})
+
+static int check_clus_chain(struct exfat_de_iter *de_iter,
+			    struct exfat_inode *node)
+{
+	struct exfat *exfat = de_iter->exfat;
+	struct exfat_dentry *stream_de;
+	clus_t clus, prev, next;
+	uint64_t count, max_count;
+
+	clus = node->first_clus;
+	prev = EXFAT_EOF_CLUSTER;
+	count = 0;
+	max_count = DIV_ROUND_UP(node->size, exfat->clus_size);
+
+	if (node->size == 0 && node->first_clus == EXFAT_FREE_CLUSTER)
+		return 0;
+
+	/* the first cluster is wrong */
+	if ((node->size == 0 && node->first_clus != EXFAT_FREE_CLUSTER) ||
+	    (node->size > 0 && !exfat_heap_clus(exfat, node->first_clus))) {
+		if (repair_file_ask(de_iter, node,
+				    ER_FILE_FIRST_CLUS,
+				    "size %#" PRIx64 ", but the first cluster %#x",
+				    node->size, node->first_clus))
+			goto truncate_file;
+		else
+			return -EINVAL;
+	}
+
+	while (clus != EXFAT_EOF_CLUSTER) {
+		if (count >= max_count) {
+			if (node->is_contiguous)
+				break;
+			if (repair_file_ask(de_iter, node,
+					    ER_FILE_SMALLER_SIZE,
+					    "more clusters are allocated. truncate to %"
+					    PRIu64 " bytes",
+					    count * exfat->clus_size))
+				goto truncate_file;
+			else
+				return -EINVAL;
+		}
+
+		/*
+		 * This cluster is already allocated. it may be shared with
+		 * the other file, or there is a loop in cluster chain.
+		 */
+		if (exfat_bitmap_get(exfat->alloc_bitmap, clus)) {
+			if (repair_file_ask(de_iter, node,
+					    ER_FILE_DUPLICATED_CLUS,
+					    "cluster is already allocated for the other file. truncated to %"
+					    PRIu64 " bytes",
+					    count * exfat->clus_size))
+				goto truncate_file;
+			else
+				return -EINVAL;
+		}
+
+		if (!exfat_bitmap_get(exfat->disk_bitmap, clus)) {
+			if (!repair_file_ask(de_iter, node,
+					     ER_FILE_INVALID_CLUS,
+					     "cluster %#x is marked as free",
+					     clus))
+				return -EINVAL;
+		}
+
+		/* This cluster is allocated or not */
+		if (exfat_get_inode_next_clus(exfat, node, clus, &next))
+			goto truncate_file;
+		if (next == EXFAT_BAD_CLUSTER) {
+			if (repair_file_ask(de_iter, node,
+					    ER_FILE_INVALID_CLUS,
+					    "BAD cluster. truncate to %"
+					    PRIu64 " bytes",
+					    count * exfat->clus_size))
+				goto truncate_file;
+			else
+				return -EINVAL;
+		} else if (!node->is_contiguous) {
+			if (next != EXFAT_EOF_CLUSTER &&
+			    !exfat_heap_clus(exfat, next)) {
+				if (repair_file_ask(de_iter, node,
+						    ER_FILE_INVALID_CLUS,
+						    "broken cluster chain. truncate to %"
+						    PRIu64 " bytes",
+						    (count + 1) * exfat->clus_size)) {
+					count++;
+					prev = clus;
+					exfat_bitmap_set(exfat->alloc_bitmap,
+							 clus);
+					goto truncate_file;
+				} else {
+					return -EINVAL;
+				}
+			}
+		}
+
+		count++;
+		exfat_bitmap_set(exfat->alloc_bitmap, clus);
+		prev = clus;
+		clus = next;
+	}
+
+	if (count < max_count) {
+		if (repair_file_ask(de_iter, node, ER_FILE_LARGER_SIZE,
+				    "less clusters are allocated. truncates to %"
+				    PRIu64 " bytes",
+				    count * exfat->clus_size))
+			goto truncate_file;
+		else
+			return -EINVAL;
+	}
+
+	return 0;
+truncate_file:
+	node->size = count * exfat->clus_size;
+	if (!exfat_heap_clus(exfat, prev))
+		node->first_clus = EXFAT_FREE_CLUSTER;
+
+	exfat_de_iter_get_dirty(de_iter, 1, &stream_de);
+	if (count * exfat->clus_size <
+	    le64_to_cpu(stream_de->stream_valid_size))
+		stream_de->stream_valid_size = cpu_to_le64(
+							   count * exfat->clus_size);
+	if (!exfat_heap_clus(exfat, prev))
+		stream_de->stream_start_clu = EXFAT_FREE_CLUSTER;
+	stream_de->stream_size = cpu_to_le64(
+					     count * exfat->clus_size);
+
+	/* remaining clusters will be freed while FAT is compared with
+	 * alloc_bitmap.
+	 */
+	if (!node->is_contiguous && exfat_heap_clus(exfat, prev)) {
+		if (exfat_set_fat(exfat, prev, EXFAT_EOF_CLUSTER))
+			return -EIO;
+	}
+	return 1;
+}
+
+static int root_check_clus_chain(struct exfat *exfat,
+				 struct exfat_inode *node,
+				 clus_t *clus_count)
+{
+	clus_t clus, next, prev = EXFAT_EOF_CLUSTER;
+
+	if (!exfat_heap_clus(exfat, node->first_clus))
+		goto out_trunc;
+
+	clus = node->first_clus;
+	*clus_count = 0;
+
+	do {
+		if (exfat_bitmap_get(exfat->alloc_bitmap, clus)) {
+			if (exfat_repair_ask(&exfat_fsck,
+					     ER_FILE_DUPLICATED_CLUS,
+					     "ERROR: the cluster chain of root is cyclic"))
+				goto out_trunc;
+			return -EINVAL;
+		}
+
+		exfat_bitmap_set(exfat->alloc_bitmap, clus);
+
+		if (exfat_get_inode_next_clus(exfat, node, clus, &next)) {
+			exfat_err("ERROR: failed to read the fat entry of root");
+			goto out_trunc;
+		}
+
+		if (next != EXFAT_EOF_CLUSTER && !exfat_heap_clus(exfat, next)) {
+			if (exfat_repair_ask(&exfat_fsck,
+					     ER_FILE_INVALID_CLUS,
+					     "ERROR: the cluster chain of root is broken")) {
+				if (next != EXFAT_BAD_CLUSTER) {
+					prev = clus;
+					(*clus_count)++;
+				}
+				goto out_trunc;
+			}
+			return -EINVAL;
+		}
+
+		prev = clus;
+		clus = next;
+		(*clus_count)++;
+	} while (clus != EXFAT_EOF_CLUSTER);
+
+	return 0;
+out_trunc:
+	if (!exfat_heap_clus(exfat, prev)) {
+		exfat_err("ERROR: the start cluster of root is wrong\n");
+		return -EINVAL;
+	}
+	node->size = *clus_count * exfat->clus_size;
+	return exfat_set_fat(exfat, prev, EXFAT_EOF_CLUSTER);
+}
+
+static int boot_region_checksum(int dev_fd,
+				int bs_offset, unsigned int sect_size)
+{
+	void *sect;
+	unsigned int i;
+	uint32_t checksum;
+	int ret = 0;
+
+	sect = malloc(sect_size);
+	if (!sect)
+		return -ENOMEM;
+
+	checksum = 0;
+	for (i = 0; i < 11; i++) {
+		if (exfat_read(dev_fd, sect, sect_size,
+				bs_offset * sect_size + i * sect_size) !=
+				(ssize_t)sect_size) {
+			exfat_err("failed to read boot region\n");
+			ret = -EIO;
+			goto out;
+		}
+		boot_calc_checksum(sect, sect_size, i == 0, &checksum);
+	}
+
+	if (exfat_read(dev_fd, sect, sect_size,
+			bs_offset * sect_size + 11 * sect_size) !=
+			(ssize_t)sect_size) {
+		exfat_err("failed to read a boot checksum sector\n");
+		ret = -EIO;
+		goto out;
+	}
+
+	for (i = 0; i < sect_size/sizeof(checksum); i++) {
+		if (le32_to_cpu(((__le32 *)sect)[i]) != checksum) {
+			exfat_err("checksum of boot region is not correct. %#x, but expected %#x\n",
+				le32_to_cpu(((__le32 *)sect)[i]), checksum);
+			ret = -EINVAL;
+			goto out;
+		}
+	}
+out:
+	free(sect);
+	return ret;
+}
+
+static int exfat_mark_volume_dirty(struct exfat *exfat, bool dirty)
+{
+	uint16_t flags;
+
+	flags = le16_to_cpu(exfat->bs->bsx.vol_flags);
+	if (dirty)
+		flags |= 0x02;
+	else
+		flags &= ~0x02;
+
+	exfat->bs->bsx.vol_flags = cpu_to_le16(flags);
+	if (exfat_write(exfat->blk_dev->dev_fd, exfat->bs,
+			sizeof(struct pbr), 0) != (ssize_t)sizeof(struct pbr)) {
+		exfat_err("failed to set VolumeDirty\n");
+		return -EIO;
+	}
+
+	if (fsync(exfat->blk_dev->dev_fd) != 0) {
+		exfat_err("failed to set VolumeDirty\n");
+		return -EIO;
+	}
+	return 0;
+}
+
+static int read_boot_region(struct exfat_blk_dev *bd, struct pbr **pbr,
+			    int bs_offset, unsigned int sect_size,
+			    bool verbose)
+{
+	struct pbr *bs;
+	int ret = -EINVAL;
+
+	*pbr = NULL;
+	bs = (struct pbr *)malloc(sizeof(struct pbr));
+	if (!bs) {
+		exfat_err("failed to allocate memory\n");
+		return -ENOMEM;
+	}
+
+	if (exfat_read(bd->dev_fd, bs, sizeof(*bs),
+			bs_offset * sect_size) != (ssize_t)sizeof(*bs)) {
+		exfat_err("failed to read a boot sector\n");
+		ret = -EIO;
+		goto err;
+	}
+
+	if (memcmp(bs->bpb.oem_name, "EXFAT   ", 8) != 0) {
+		if (verbose)
+			exfat_err("failed to find exfat file system\n");
+		goto err;
+	}
+
+	ret = boot_region_checksum(bd->dev_fd, bs_offset, sect_size);
+	if (ret < 0)
+		goto err;
+
+	ret = -EINVAL;
+	if (EXFAT_SECTOR_SIZE(bs) < 512 || EXFAT_SECTOR_SIZE(bs) > 4 * KB) {
+		if (verbose)
+			exfat_err("too small or big sector size: %d\n",
+				  EXFAT_SECTOR_SIZE(bs));
+		goto err;
+	}
+
+	if (EXFAT_CLUSTER_SIZE(bs) > 32 * MB) {
+		if (verbose)
+			exfat_err("too big cluster size: %d\n",
+				  EXFAT_CLUSTER_SIZE(bs));
+		goto err;
+	}
+
+	if (bs->bsx.fs_version[1] != 1 || bs->bsx.fs_version[0] != 0) {
+		if (verbose)
+			exfat_err("unsupported exfat version: %d.%d\n",
+				  bs->bsx.fs_version[1], bs->bsx.fs_version[0]);
+		goto err;
+	}
+
+	if (bs->bsx.num_fats != 1) {
+		if (verbose)
+			exfat_err("unsupported FAT count: %d\n",
+				  bs->bsx.num_fats);
+		goto err;
+	}
+
+	if (le64_to_cpu(bs->bsx.vol_length) * EXFAT_SECTOR_SIZE(bs) >
+			bd->size) {
+		if (verbose)
+			exfat_err("too large sector count: %" PRIu64 ", expected: %llu\n",
+				  le64_to_cpu(bs->bsx.vol_length),
+				  bd->num_sectors);
+		goto err;
+	}
+
+	if (le32_to_cpu(bs->bsx.clu_count) * EXFAT_CLUSTER_SIZE(bs) >
+			bd->size) {
+		if (verbose)
+			exfat_err("too large cluster count: %u, expected: %u\n",
+				  le32_to_cpu(bs->bsx.clu_count),
+				  bd->num_clusters);
+		goto err;
+	}
+
+	*pbr = bs;
+	return 0;
+err:
+	free(bs);
+	return ret;
+}
+
+static int restore_boot_region(struct exfat_blk_dev *bd, unsigned int sect_size)
+{
+	int i;
+	char *sector;
+	int ret;
+
+	sector = malloc(sect_size);
+	if (!sector)
+		return -ENOMEM;
+
+	for (i = 0; i < 12; i++) {
+		if (exfat_read(bd->dev_fd, sector, sect_size,
+				BACKUP_BOOT_SEC_IDX * sect_size +
+				i * sect_size) !=
+				(ssize_t)sect_size) {
+			ret = -EIO;
+			goto free_sector;
+		}
+		if (i == 0)
+			((struct pbr *)sector)->bsx.perc_in_use = 0xff;
+
+		if (exfat_write(bd->dev_fd, sector, sect_size,
+				BOOT_SEC_IDX * sect_size +
+				i * sect_size) !=
+				(ssize_t)sect_size) {
+			ret = -EIO;
+			goto free_sector;
+		}
+	}
+
+	if (fsync(bd->dev_fd)) {
+		ret = -EIO;
+		goto free_sector;
+	}
+	ret = 0;
+
+free_sector:
+	free(sector);
+	return ret;
+}
+
+static int exfat_boot_region_check(struct exfat_blk_dev *blkdev,
+				   struct pbr **bs,
+				   bool ignore_bad_fs_name)
+{
+	struct pbr *boot_sect;
+	unsigned int sect_size;
+	int ret;
+
+	/* First, find out the exfat sector size */
+	boot_sect = malloc(sizeof(*boot_sect));
+	if (boot_sect == NULL)
+		return -ENOMEM;
+
+	if (exfat_read(blkdev->dev_fd, boot_sect,
+		       sizeof(*boot_sect), 0) != (ssize_t)sizeof(*boot_sect)) {
+		exfat_err("failed to read Main boot sector\n");
+		free(boot_sect);
+		return -EIO;
+	}
+
+	if (memcmp(boot_sect->bpb.oem_name, "EXFAT   ", 8) != 0 &&
+	    !ignore_bad_fs_name) {
+		exfat_err("Bad fs_name in boot sector, which does not describe a valid exfat filesystem\n");
+		free(boot_sect);
+		return -ENOTSUP;
+	}
+
+	sect_size = 1 << boot_sect->bsx.sect_size_bits;
+	free(boot_sect);
+
+	/* check boot regions */
+	ret = read_boot_region(blkdev, bs,
+			       BOOT_SEC_IDX, sect_size, true);
+	if (ret == -EINVAL &&
+	    exfat_repair_ask(&exfat_fsck, ER_BS_BOOT_REGION,
+			     "boot region is corrupted. try to restore the region from backup"
+				)) {
+		const unsigned int sector_sizes[] = {512, 4096, 1024, 2048};
+		unsigned int i;
+
+		if (sect_size >= 512 && sect_size <= EXFAT_MAX_SECTOR_SIZE) {
+			ret = read_boot_region(blkdev, bs,
+					       BACKUP_BOOT_SEC_IDX, sect_size,
+					       false);
+			if (!ret)
+				goto restore;
+		}
+
+		for (i = 0; i < sizeof(sector_sizes)/sizeof(sector_sizes[0]); i++) {
+			if (sector_sizes[i] == sect_size)
+				continue;
+
+			ret = read_boot_region(blkdev, bs,
+					       BACKUP_BOOT_SEC_IDX,
+					       sector_sizes[i], false);
+			if (!ret) {
+				sect_size = sector_sizes[i];
+				goto restore;
+			}
+		}
+		exfat_err("backup boot region is also corrupted\n");
+	}
+
+	return ret;
+restore:
+	ret = restore_boot_region(blkdev, sect_size);
+	if (ret) {
+		exfat_err("failed to restore boot region from backup\n");
+		free(*bs);
+		*bs = NULL;
+	}
+	return ret;
+}
+
+static uint16_t file_calc_checksum(struct exfat_de_iter *iter)
+{
+	uint16_t checksum;
+	struct exfat_dentry *file_de, *de;
+	int i;
+
+	checksum = 0;
+	exfat_de_iter_get(iter, 0, &file_de);
+
+	exfat_calc_dentry_checksum(file_de, &checksum, true);
+	for (i = 1; i <= file_de->file_num_ext; i++) {
+		exfat_de_iter_get(iter, i, &de);
+		exfat_calc_dentry_checksum(de, &checksum, false);
+	}
+	return checksum;
+}
+
+/*
+ * return 0 if there are no errors, or 1 if errors are fixed, or
+ * an error code
+ */
+static int check_inode(struct exfat_de_iter *iter, struct exfat_inode *node)
+{
+	struct exfat *exfat = iter->exfat;
+	struct exfat_dentry *dentry;
+	int ret = 0;
+	uint16_t checksum;
+	bool valid = true;
+
+	ret = check_clus_chain(iter, node);
+	if (ret < 0)
+		return ret;
+
+	if (node->size > le32_to_cpu(exfat->bs->bsx.clu_count) *
+				(uint64_t)exfat->clus_size) {
+		fsck_err(iter->parent, node,
+			"size %" PRIu64 " is greater than cluster heap\n",
+			node->size);
+		valid = false;
+	}
+
+	if (node->size == 0 && node->is_contiguous) {
+		if (repair_file_ask(iter, node, ER_FILE_ZERO_NOFAT,
+				"empty, but has no Fat chain")) {
+			exfat_de_iter_get_dirty(iter, 1, &dentry);
+			dentry->stream_flags &= ~EXFAT_SF_CONTIGUOUS;
+			ret = 1;
+		} else
+			valid = false;
+	}
+
+	if ((node->attr & ATTR_SUBDIR) &&
+			node->size % exfat->clus_size != 0) {
+		fsck_err(iter->parent, node,
+			"directory size %" PRIu64 " is not divisible by %d\n",
+			node->size, exfat->clus_size);
+		valid = false;
+	}
+
+	checksum = file_calc_checksum(iter);
+	exfat_de_iter_get(iter, 0, &dentry);
+	if (checksum != le16_to_cpu(dentry->file_checksum)) {
+		exfat_de_iter_get_dirty(iter, 0, &dentry);
+		dentry->file_checksum = cpu_to_le16(checksum);
+		ret = 1;
+	}
+
+	return valid ? ret : -EINVAL;
+}
+
+static int check_name_dentry_set(struct exfat_de_iter *iter,
+				 struct exfat_inode *inode)
+{
+	struct exfat_dentry *stream_de;
+	size_t name_len;
+	__u16 hash;
+
+	exfat_de_iter_get(iter, 1, &stream_de);
+
+	name_len = exfat_utf16_len(inode->name, NAME_BUFFER_SIZE);
+	if (stream_de->stream_name_len != name_len) {
+		if (repair_file_ask(iter, NULL, ER_DE_NAME_LEN,
+				    "the name length of a file is wrong")) {
+			exfat_de_iter_get_dirty(iter, 1, &stream_de);
+			stream_de->stream_name_len = (__u8)name_len;
+		} else {
+			return -EINVAL;
+		}
+	}
+
+	hash = exfat_calc_name_hash(iter->exfat, inode->name, (int)name_len);
+	if (cpu_to_le16(hash) != stream_de->stream_name_hash) {
+		if (repair_file_ask(iter, NULL, ER_DE_NAME_HASH,
+				    "the name hash of a file is wrong")) {
+			exfat_de_iter_get_dirty(iter, 1, &stream_de);
+			stream_de->stream_name_hash = cpu_to_le16(hash);
+		} else {
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+
+static int check_bad_char(char w)
+{
+	return (w < 0x0020) || (w == '*') || (w == '?') || (w == '<') ||
+		(w == '>') || (w == '|') || (w == '"') || (w == ':') ||
+		(w == '/') || (w == '\\');
+}
+
+static char *get_rename_from_user(struct exfat_de_iter *iter)
+{
+	char *rename = malloc(ENTRY_NAME_MAX + 2);
+
+	if (!rename)
+		return NULL;
+
+retry:
+	/* +2 means LF(Line Feed) and NULL terminator */
+	memset(rename, 0x1, ENTRY_NAME_MAX + 2);
+	printf("New name: ");
+	if (fgets(rename, ENTRY_NAME_MAX + 2, stdin)) {
+		int i, len, err;
+		struct exfat_lookup_filter filter;
+
+		len = strlen(rename);
+		/* Remove LF in filename */
+		rename[len - 1] = '\0';
+		for (i = 0; i < len - 1; i++) {
+			if (check_bad_char(rename[i])) {
+				printf("filename contain invalid character(%c)\n", rename[i]);
+				goto retry;
+			}
+		}
+
+		exfat_de_iter_flush(iter);
+		err = exfat_lookup_file(iter->exfat, iter->parent, rename, &filter);
+		if (!err) {
+			printf("file(%s) already exists, retry to insert name\n", rename);
+			goto retry;
+		}
+	}
+
+	return rename;
+}
+
+static char *generate_rename(struct exfat_de_iter *iter)
+{
+	char *rename;
+
+	if (iter->dot_name_num > DOT_NAME_NUM_MAX)
+		return NULL;
+
+	rename = malloc(ENTRY_NAME_MAX + 1);
+	if (!rename)
+		return NULL;
+
+	while (1) {
+		struct exfat_lookup_filter filter;
+		int err;
+
+		snprintf(rename, ENTRY_NAME_MAX + 1, "FILE%07d.CHK",
+			 iter->dot_name_num++);
+		err = exfat_lookup_file(iter->exfat, iter->parent, rename,
+					&filter);
+		if (!err)
+			continue;
+		break;
+	}
+
+	return rename;
+}
+
+const __le16 MSDOS_DOT[ENTRY_NAME_MAX] = {cpu_to_le16(46), 0, };
+const __le16 MSDOS_DOTDOT[ENTRY_NAME_MAX] = {cpu_to_le16(46), cpu_to_le16(46), 0, };
+
+static int handle_dot_dotdot_filename(struct exfat_de_iter *iter,
+				      struct exfat_dentry *dentry,
+				      int strm_name_len)
+{
+	char *filename;
+	char error_msg[150];
+	int num;
+
+	if (!memcmp(dentry->name_unicode, MSDOS_DOT, strm_name_len * 2))
+		filename = ".";
+	else if (!memcmp(dentry->name_unicode, MSDOS_DOTDOT,
+			 strm_name_len * 2))
+		filename = "..";
+	else
+		return 0;
+
+	sprintf(error_msg, "ERROR: '%s' filename is not allowed.\n"
+			" [1] Insert the name you want to rename.\n"
+			" [2] Automatically renames filename.\n"
+			" [3] Bypass this check(No repair)\n", filename);
+ask_again:
+	num = exfat_repair_ask(&exfat_fsck, ER_DE_DOT_NAME,
+			       error_msg);
+	if (num) {
+		__le16 utf16_name[ENTRY_NAME_MAX];
+		char *rename = NULL;
+		__u16 hash;
+		struct exfat_dentry *stream_de;
+		int name_len, ret;
+
+		switch (num) {
+		case 1:
+			rename = get_rename_from_user(iter);
+			break;
+		case 2:
+			rename = generate_rename(iter);
+			break;
+		case 3:
+			break;
+		default:
+			exfat_info("select 1 or 2 number instead of %d\n", num);
+			goto ask_again;
+		}
+
+		if (!rename)
+			return -EINVAL;
+
+		exfat_info("%s filename is renamed to %s\n", filename, rename);
+
+		exfat_de_iter_get_dirty(iter, 2, &dentry);
+
+		memset(utf16_name, 0, sizeof(utf16_name));
+		ret = exfat_utf16_enc(rename, utf16_name, sizeof(utf16_name));
+		free(rename);
+		if (ret < 0)
+			return ret;
+
+		memcpy(dentry->name_unicode, utf16_name, ENTRY_NAME_MAX * 2);
+		name_len = exfat_utf16_len(utf16_name, ENTRY_NAME_MAX * 2);
+		hash = exfat_calc_name_hash(iter->exfat, utf16_name, (int)name_len);
+		exfat_de_iter_get_dirty(iter, 1, &stream_de);
+		stream_de->stream_name_len = (__u8)name_len;
+		stream_de->stream_name_hash = cpu_to_le16(hash);
+	}
+
+	return 0;
+}
+
+static int read_file_dentry_set(struct exfat_de_iter *iter,
+				struct exfat_inode **new_node, int *skip_dentries)
+{
+	struct exfat_dentry *file_de, *stream_de, *dentry;
+	struct exfat_inode *node = NULL;
+	int i, ret;
+	bool need_delete = false;
+	uint16_t checksum;
+
+	ret = exfat_de_iter_get(iter, 0, &file_de);
+	if (ret || file_de->type != EXFAT_FILE) {
+		exfat_err("failed to get file dentry\n");
+		return -EINVAL;
+	}
+
+	checksum = file_calc_checksum(iter);
+	if (checksum != le16_to_cpu(file_de->file_checksum)) {
+		if (repair_file_ask(iter, NULL, ER_DE_CHECKSUM,
+				    "the checksum of a file is wrong"))
+			need_delete = true;
+		*skip_dentries = 1;
+		goto skip_dset;
+	}
+
+	if (file_de->file_num_ext < 2) {
+		if (repair_file_ask(iter, NULL, ER_DE_SECONDARY_COUNT,
+				    "a file has too few secondary count. %d",
+				    file_de->file_num_ext))
+			need_delete = true;
+		*skip_dentries = 1;
+		goto skip_dset;
+	}
+
+	ret = exfat_de_iter_get(iter, 1, &stream_de);
+	if (ret || stream_de->type != EXFAT_STREAM) {
+		if (repair_file_ask(iter, NULL, ER_DE_STREAM,
+				    "failed to get stream dentry"))
+			need_delete = true;
+		*skip_dentries = 2;
+		goto skip_dset;
+	}
+
+	*new_node = NULL;
+	node = exfat_alloc_inode(le16_to_cpu(file_de->file_attr));
+	if (!node)
+		return -ENOMEM;
+
+	for (i = 2; i <= file_de->file_num_ext; i++) {
+		ret = exfat_de_iter_get(iter, i, &dentry);
+		if (ret || dentry->type != EXFAT_NAME) {
+			if (i > 2 && repair_file_ask(iter, NULL, ER_DE_NAME,
+						     "failed to get name dentry")) {
+				exfat_de_iter_get_dirty(iter, 0, &file_de);
+				file_de->file_num_ext = i - 1;
+				break;
+			}
+			*skip_dentries = i + 1;
+			goto skip_dset;
+		}
+
+		memcpy(node->name +
+		       (i - 2) * ENTRY_NAME_MAX, dentry->name_unicode,
+		       sizeof(dentry->name_unicode));
+	}
+
+	ret = check_name_dentry_set(iter, node);
+	if (ret) {
+		*skip_dentries = file_de->file_num_ext + 1;
+		goto skip_dset;
+	}
+
+	if (file_de->file_num_ext == 2 && stream_de->stream_name_len <= 2) {
+		ret = handle_dot_dotdot_filename(iter, dentry,
+				stream_de->stream_name_len);
+		if (ret < 0) {
+			*skip_dentries = file_de->file_num_ext + 1;
+			goto skip_dset;
+		}
+	}
+
+	node->first_clus = le32_to_cpu(stream_de->stream_start_clu);
+	node->is_contiguous =
+		((stream_de->stream_flags & EXFAT_SF_CONTIGUOUS) != 0);
+	node->size = le64_to_cpu(stream_de->stream_size);
+
+	if (node->size < le64_to_cpu(stream_de->stream_valid_size)) {
+		*skip_dentries = file_de->file_num_ext + 1;
+		if (repair_file_ask(iter, node, ER_FILE_VALID_SIZE,
+				    "valid size %" PRIu64 " greater than size %" PRIu64,
+				    le64_to_cpu(stream_de->stream_valid_size),
+				    node->size)) {
+			exfat_de_iter_get_dirty(iter, 1, &stream_de);
+			stream_de->stream_valid_size =
+					stream_de->stream_size;
+		} else {
+			*skip_dentries = file_de->file_num_ext + 1;
+			goto skip_dset;
+		}
+	}
+
+	*skip_dentries = (file_de->file_num_ext + 1);
+	*new_node = node;
+	return 0;
+skip_dset:
+	if (need_delete) {
+		exfat_de_iter_get_dirty(iter, 0, &dentry);
+		dentry->type &= EXFAT_DELETE;
+	}
+	for (i = 1; i < *skip_dentries; i++) {
+		exfat_de_iter_get(iter, i, &dentry);
+		if (dentry->type == EXFAT_FILE)
+			break;
+		if (need_delete) {
+			exfat_de_iter_get_dirty(iter, i, &dentry);
+			dentry->type &= EXFAT_DELETE;
+		}
+	}
+	*skip_dentries = i;
+	*new_node = NULL;
+	exfat_free_inode(node);
+	return need_delete ? 1 : -EINVAL;
+}
+
+static int read_file(struct exfat_de_iter *de_iter,
+		struct exfat_inode **new_node, int *dentry_count)
+{
+	struct exfat_inode *node;
+	int ret;
+
+	*new_node = NULL;
+
+	ret = read_file_dentry_set(de_iter, &node, dentry_count);
+	if (ret)
+		return ret;
+
+	ret = check_inode(de_iter, node);
+	if (ret < 0) {
+		exfat_free_inode(node);
+		return -EINVAL;
+	}
+
+	if (node->attr & ATTR_SUBDIR)
+		exfat_stat.dir_count++;
+	else
+		exfat_stat.file_count++;
+	*new_node = node;
+	return ret;
+}
+
+static int read_bitmap(struct exfat *exfat)
+{
+	struct exfat_lookup_filter filter = {
+		.in.type	= EXFAT_BITMAP,
+		.in.filter	= NULL,
+		.in.param	= NULL,
+	};
+	struct exfat_dentry *dentry;
+	int retval;
+
+	retval = exfat_lookup_dentry_set(exfat, exfat->root, &filter);
+	if (retval)
+		return retval;
+
+	dentry = filter.out.dentry_set;
+	exfat_debug("start cluster %#x, size %#" PRIx64 "\n",
+			le32_to_cpu(dentry->bitmap_start_clu),
+			le64_to_cpu(dentry->bitmap_size));
+
+	if (le64_to_cpu(dentry->bitmap_size) <
+			DIV_ROUND_UP(exfat->clus_count, 8)) {
+		exfat_err("invalid size of allocation bitmap. 0x%" PRIx64 "\n",
+				le64_to_cpu(dentry->bitmap_size));
+		return -EINVAL;
+	}
+	if (!exfat_heap_clus(exfat, le32_to_cpu(dentry->bitmap_start_clu))) {
+		exfat_err("invalid start cluster of allocate bitmap. 0x%x\n",
+				le32_to_cpu(dentry->bitmap_start_clu));
+		return -EINVAL;
+	}
+
+	exfat->disk_bitmap_clus = le32_to_cpu(dentry->bitmap_start_clu);
+	exfat->disk_bitmap_size = DIV_ROUND_UP(exfat->clus_count, 8);
+
+	exfat_bitmap_set_range(exfat, exfat->alloc_bitmap,
+			       le64_to_cpu(dentry->bitmap_start_clu),
+			       DIV_ROUND_UP(exfat->disk_bitmap_size,
+					    exfat->clus_size));
+	free(filter.out.dentry_set);
+
+	if (exfat_read(exfat->blk_dev->dev_fd, exfat->disk_bitmap,
+			exfat->disk_bitmap_size,
+			exfat_c2o(exfat, exfat->disk_bitmap_clus)) !=
+			(ssize_t)exfat->disk_bitmap_size)
+		return -EIO;
+	return 0;
+}
+
+static int decompress_upcase_table(const __le16 *in_table, size_t in_len,
+				   __u16 *out_table, size_t out_len)
+{
+	size_t i, k;
+	uint16_t ch;
+
+	if (in_len > out_len)
+		return -E2BIG;
+
+	for (k = 0; k < out_len; k++)
+		out_table[k] = k;
+
+	for (i = 0, k = 0; i < in_len && k < out_len; i++) {
+		ch = le16_to_cpu(in_table[i]);
+
+		if (ch == 0xFFFF && i + 1 < in_len) {
+			uint16_t len = le16_to_cpu(in_table[++i]);
+
+			k += len;
+		} else {
+			out_table[k++] = ch;
+		}
+	}
+	return 0;
+}
+
+static int read_upcase_table(struct exfat *exfat)
+{
+	struct exfat_lookup_filter filter = {
+		.in.type	= EXFAT_UPCASE,
+		.in.filter	= NULL,
+		.in.param	= NULL,
+	};
+	struct exfat_dentry *dentry = NULL;
+	__le16 *upcase = NULL;
+	int retval;
+	ssize_t size;
+	__le32 checksum;
+
+	retval = exfat_lookup_dentry_set(exfat, exfat->root, &filter);
+	if (retval)
+		return retval;
+
+	dentry = filter.out.dentry_set;
+
+	if (!exfat_heap_clus(exfat, le32_to_cpu(dentry->upcase_start_clu))) {
+		exfat_err("invalid start cluster of upcase table. 0x%x\n",
+			le32_to_cpu(dentry->upcase_start_clu));
+		retval = -EINVAL;
+		goto out;
+	}
+
+	size = (ssize_t)le64_to_cpu(dentry->upcase_size);
+	if (size > (ssize_t)(EXFAT_MAX_UPCASE_CHARS * sizeof(__le16)) ||
+			size == 0 || size % sizeof(__le16)) {
+		exfat_err("invalid size of upcase table. 0x%" PRIx64 "\n",
+			le64_to_cpu(dentry->upcase_size));
+		retval = -EINVAL;
+		goto out;
+	}
+
+	upcase = (__le16 *)malloc(size);
+	if (!upcase) {
+		exfat_err("failed to allocate upcase table\n");
+		retval = -ENOMEM;
+		goto out;
+	}
+
+	if (exfat_read(exfat->blk_dev->dev_fd, upcase, size,
+			exfat_c2o(exfat,
+			le32_to_cpu(dentry->upcase_start_clu))) != size) {
+		exfat_err("failed to read upcase table\n");
+		retval = -EIO;
+		goto out;
+	}
+
+	checksum = 0;
+	boot_calc_checksum((unsigned char *)upcase, size, false, &checksum);
+	if (le32_to_cpu(dentry->upcase_checksum) != checksum) {
+		exfat_err("corrupted upcase table %#x (expected: %#x)\n",
+			checksum, le32_to_cpu(dentry->upcase_checksum));
+		retval = -EINVAL;
+		goto out;
+	}
+
+	exfat_bitmap_set_range(exfat, exfat->alloc_bitmap,
+			       le32_to_cpu(dentry->upcase_start_clu),
+			       DIV_ROUND_UP(le64_to_cpu(dentry->upcase_size),
+					    exfat->clus_size));
+
+	exfat->upcase_table = calloc(1,
+				     sizeof(uint16_t) * EXFAT_UPCASE_TABLE_CHARS);
+	if (!exfat->upcase_table) {
+		retval = -EIO;
+		goto out;
+	}
+
+	decompress_upcase_table(upcase, size / 2,
+				exfat->upcase_table, EXFAT_UPCASE_TABLE_CHARS);
+out:
+	if (dentry)
+		free(dentry);
+	if (upcase)
+		free(upcase);
+	return retval;
+}
+
+static int read_children(struct exfat_fsck *fsck, struct exfat_inode *dir)
+{
+	struct exfat *exfat = fsck->exfat;
+	struct exfat_inode *node = NULL;
+	struct exfat_dentry *dentry;
+	struct exfat_de_iter *de_iter;
+	int dentry_count;
+	int ret;
+
+	de_iter = &fsck->de_iter;
+	ret = exfat_de_iter_init(de_iter, exfat, dir, fsck->buffer_desc);
+	if (ret == EOF)
+		return 0;
+	else if (ret)
+		return ret;
+
+	while (1) {
+		ret = exfat_de_iter_get(de_iter, 0, &dentry);
+		if (ret == EOF) {
+			break;
+		} else if (ret) {
+			fsck_err(dir->parent, dir,
+				"failed to get a dentry. %d\n", ret);
+			goto err;
+		}
+
+		dentry_count = 1;
+
+		switch (dentry->type) {
+		case EXFAT_FILE:
+			ret = read_file(de_iter, &node, &dentry_count);
+			if (ret < 0) {
+				exfat_stat.error_count++;
+				break;
+			} else if (ret) {
+				exfat_stat.error_count++;
+				exfat_stat.fixed_count++;
+			}
+
+			if (node) {
+				if ((node->attr & ATTR_SUBDIR) && node->size) {
+					node->parent = dir;
+					list_add_tail(&node->sibling,
+						      &dir->children);
+					list_add_tail(&node->list,
+						      &exfat->dir_list);
+				} else {
+					exfat_free_inode(node);
+				}
+			}
+			break;
+		case EXFAT_LAST:
+			goto out;
+		case EXFAT_VOLUME:
+		case EXFAT_BITMAP:
+		case EXFAT_UPCASE:
+			if (dir == exfat->root)
+				break;
+			/* fallthrough */
+		default:
+			if (IS_EXFAT_DELETED(dentry->type))
+				break;
+			if (repair_file_ask(de_iter, NULL, ER_DE_UNKNOWN,
+					    "unknown entry type %#x at %07" PRIx64,
+					    dentry->type,
+					    exfat_de_iter_file_offset(de_iter))) {
+				struct exfat_dentry *dentry;
+
+				exfat_de_iter_get_dirty(de_iter, 0, &dentry);
+				dentry->type &= EXFAT_DELETE;
+			}
+			break;
+		}
+
+		exfat_de_iter_advance(de_iter, dentry_count);
+	}
+out:
+	exfat_de_iter_flush(de_iter);
+	return 0;
+err:
+	exfat_free_children(dir, false);
+	INIT_LIST_HEAD(&dir->children);
+	exfat_de_iter_flush(de_iter);
+	return ret;
+}
+
+/* write bitmap segments for clusters which are marked
+ * as free, but allocated to files.
+ */
+static int write_bitmap(struct exfat_fsck *fsck)
+{
+	struct exfat *exfat = fsck->exfat;
+	bitmap_t *disk_b, *alloc_b, *ohead_b;
+	off_t dev_offset;
+	unsigned int i, bitmap_bytes, byte_offset, write_bytes;
+
+	dev_offset = exfat_c2o(exfat, exfat->disk_bitmap_clus);
+	bitmap_bytes = EXFAT_BITMAP_SIZE(le32_to_cpu(exfat->bs->bsx.clu_count));
+
+	disk_b = (bitmap_t *)exfat->disk_bitmap;
+	alloc_b = (bitmap_t *)exfat->alloc_bitmap;
+	ohead_b = (bitmap_t *)exfat->ohead_bitmap;
+
+	for (i = 0; i < bitmap_bytes / sizeof(bitmap_t); i++)
+		ohead_b[i] = alloc_b[i] | disk_b[i];
+
+	i = 0;
+	while (i < bitmap_bytes / sizeof(bitmap_t)) {
+		if (ohead_b[i] == disk_b[i]) {
+			i++;
+			continue;
+		}
+
+		byte_offset = ((i * sizeof(bitmap_t)) / 512) * 512;
+		write_bytes = MIN(512, bitmap_bytes - byte_offset);
+
+		if (exfat_write(exfat->blk_dev->dev_fd,
+				(char *)ohead_b + byte_offset, write_bytes,
+				dev_offset + byte_offset) != (ssize_t)write_bytes)
+			return -EIO;
+
+		i = (byte_offset + write_bytes) / sizeof(bitmap_t);
+	}
+	return 0;
+
+}
+
+/*
+ * for each directory in @dir_list.
+ * 1. read all dentries and allocate exfat_nodes for files and directories.
+ *    and append directory exfat_nodes to the head of @dir_list
+ * 2. free all of file exfat_nodes.
+ * 3. if the directory does not have children, free its exfat_node.
+ */
+static int exfat_filesystem_check(struct exfat_fsck *fsck)
+{
+	struct exfat *exfat = fsck->exfat;
+	struct exfat_inode *dir;
+	int ret = 0, dir_errors;
+
+	if (!exfat->root) {
+		exfat_err("root is NULL\n");
+		return -ENOENT;
+	}
+
+	list_add(&exfat->root->list, &exfat->dir_list);
+
+	while (!list_empty(&exfat->dir_list)) {
+		dir = list_entry(exfat->dir_list.next,
+				 struct exfat_inode, list);
+
+		if (!(dir->attr & ATTR_SUBDIR)) {
+			fsck_err(dir->parent, dir,
+				"failed to travel directories. "
+				"the node is not directory\n");
+			ret = -EINVAL;
+			goto out;
+		}
+
+		dir_errors = read_children(fsck, dir);
+		if (dir_errors) {
+			exfat_resolve_path(&path_resolve_ctx, dir);
+			exfat_debug("failed to check dentries: %s\n",
+					path_resolve_ctx.local_path);
+			ret = dir_errors;
+		}
+
+		list_del(&dir->list);
+		exfat_free_file_children(dir);
+		exfat_free_ancestors(dir);
+	}
+out:
+	exfat_free_dir_list(exfat);
+	return ret;
+}
+
+static int exfat_root_dir_check(struct exfat *exfat)
+{
+	struct exfat_inode *root;
+	clus_t clus_count = 0;
+	int err;
+
+	root = exfat_alloc_inode(ATTR_SUBDIR);
+	if (!root)
+		return -ENOMEM;
+
+	exfat->root = root;
+	root->first_clus = le32_to_cpu(exfat->bs->bsx.root_cluster);
+	if (root_check_clus_chain(exfat, root, &clus_count)) {
+		exfat_err("failed to follow the cluster chain of root\n");
+		exfat_free_inode(root);
+		exfat->root = NULL;
+		return -EINVAL;
+	}
+	root->size = clus_count * exfat->clus_size;
+
+	exfat_stat.dir_count++;
+	exfat_debug("root directory: start cluster[0x%x] size[0x%" PRIx64 "]\n",
+		root->first_clus, root->size);
+
+	err = exfat_read_volume_label(exfat);
+	if (err && err != EOF)
+		exfat_err("failed to read volume label\n");
+	err = 0;
+
+	err = read_bitmap(exfat);
+	if (err) {
+		exfat_err("failed to read bitmap\n");
+		return -EINVAL;
+	}
+
+	err = read_upcase_table(exfat);
+	if (err) {
+		exfat_err("failed to read upcase table\n");
+		return -EINVAL;
+	}
+
+	root->dev_offset = 0;
+	err = exfat_build_file_dentry_set(exfat, " ", ATTR_SUBDIR,
+					  &root->dentry_set, &root->dentry_count);
+	if (err) {
+		exfat_free_inode(root);
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+static int read_lostfound(struct exfat *exfat, struct exfat_inode **lostfound)
+{
+	struct exfat_lookup_filter filter;
+	struct exfat_inode *inode;
+	int err;
+
+	err = exfat_lookup_file(exfat, exfat->root, "LOST+FOUND", &filter);
+	if (err)
+		return err;
+
+	inode = exfat_alloc_inode(ATTR_SUBDIR);
+	if (!inode) {
+		free(filter.out.dentry_set);
+		return -ENOMEM;
+	}
+
+	inode->dentry_set = filter.out.dentry_set;
+	inode->dentry_count = filter.out.dentry_count;
+	inode->dev_offset = filter.out.dev_offset;
+
+	inode->first_clus =
+		le32_to_cpu(filter.out.dentry_set[1].dentry.stream.start_clu);
+	inode->size =
+		le64_to_cpu(filter.out.dentry_set[1].dentry.stream.size);
+
+	*lostfound = inode;
+	return 0;
+}
+
+/* Create temporary files under LOST+FOUND and assign orphan
+ * chains of clusters to these files.
+ */
+static int rescue_orphan_clusters(struct exfat_fsck *fsck)
+{
+	struct exfat *exfat = fsck->exfat;
+	struct exfat_inode *lostfound;
+	bitmap_t *disk_b, *alloc_b, *ohead_b;
+	struct exfat_dentry *dset;
+	clus_t clu_count, clu, s_clu, e_clu;
+	int err, dcount;
+	unsigned int i;
+	char name[] = "FILE0000000.CHK";
+	struct exfat_dentry_loc loc;
+	struct exfat_lookup_filter lf = {
+		.in.type = EXFAT_INVAL,
+		.in.filter = NULL,
+	};
+
+	err = read_lostfound(exfat, &lostfound);
+	if (err) {
+		exfat_err("failed to find LOST+FOUND\n");
+		return err;
+	}
+
+	/* get the last empty region of LOST+FOUND */
+	err = exfat_lookup_dentry_set(exfat, lostfound, &lf);
+	if (err && err != EOF) {
+		exfat_err("failed to find the last empty slot in LOST+FOUND\n");
+		goto out;
+	}
+
+	loc.parent = lostfound;
+	loc.file_offset = lf.out.file_offset;
+	loc.dev_offset = lf.out.dev_offset;
+
+	/* build a template dentry set */
+	err = exfat_build_file_dentry_set(exfat, name, 0, &dset, &dcount);
+	if (err) {
+		exfat_err("failed to create a temporary file in LOST+FOUNDn");
+		goto out;
+	}
+	dset[1].dentry.stream.flags |= EXFAT_SF_CONTIGUOUS;
+
+	clu_count = le32_to_cpu(exfat->bs->bsx.clu_count);
+
+	/* find clusters which are not marked as free, but not allocated to
+	 * any files.
+	 */
+	disk_b = (bitmap_t *)exfat->disk_bitmap;
+	alloc_b = (bitmap_t *)exfat->alloc_bitmap;
+	ohead_b = (bitmap_t *)exfat->ohead_bitmap;
+	for (i = 0; i < EXFAT_BITMAP_SIZE(clu_count) / sizeof(bitmap_t); i++)
+		ohead_b[i] = disk_b[i] & ~alloc_b[i];
+
+	/* create temporary files and allocate contiguous orphan clusters
+	 * to each file.
+	 */
+	for (clu = EXFAT_FIRST_CLUSTER; clu < clu_count + EXFAT_FIRST_CLUSTER &&
+	     exfat_bitmap_find_one(exfat, exfat->ohead_bitmap, clu, &s_clu) == 0;) {
+		if (exfat_bitmap_find_zero(exfat, exfat->ohead_bitmap, s_clu, &e_clu))
+			e_clu = clu_count + EXFAT_FIRST_CLUSTER;
+		clu = e_clu;
+
+		snprintf(name, sizeof(name), "FILE%07d.CHK",
+			 (unsigned int)(loc.file_offset >> 5));
+		err = exfat_update_file_dentry_set(exfat, dset, dcount,
+						   name, s_clu, e_clu - s_clu);
+		if (err)
+			continue;
+		err = exfat_add_dentry_set(exfat, &loc, dset, dcount, true);
+		if (err)
+			continue;
+	}
+
+	free(dset);
+	err = 0;
+out:
+	exfat_free_inode(lostfound);
+	return err;
+}
+
+static char *bytes_to_human_readable(size_t bytes)
+{
+	static const char * const units[] = {"B", "KB", "MB", "GB", "TB", "PB"};
+	static char buf[15*4];
+	unsigned int i, shift, quoti, remain;
+	i = sizeof(units) / sizeof(units[0]) - 1;
+
+	while (i && (bytes >> i * 10) == 0)
+		i--;
+
+	shift = i * 10;
+	quoti = (unsigned int)(bytes / (1ULL << shift));
+	remain = 0;
+	if (shift > 0) {
+		remain = (unsigned int)
+			((bytes & ((1ULL << shift) - 1)) >> (shift - 10));
+		remain = (remain * 100) / 1024;
+	}
+
+	snprintf(buf, sizeof(buf), "%u.%02u %s", quoti, remain, units[i]);
+	return buf;
+}
+
+static void exfat_show_info(struct exfat_fsck *fsck, const char *dev_name)
+{
+	struct exfat *exfat = fsck->exfat;
+	bool clean;
+
+	exfat_info("sector size:  %s\n",
+		bytes_to_human_readable(1 << exfat->bs->bsx.sect_size_bits));
+	exfat_info("cluster size: %s\n",
+		bytes_to_human_readable(exfat->clus_size));
+	exfat_info("volume size:  %s\n",
+		bytes_to_human_readable(exfat->blk_dev->size));
+
+	clean = exfat_stat.error_count == 0 ||
+		exfat_stat.error_count == exfat_stat.fixed_count;
+	printf("%s: %s. directories %ld, files %ld\n", dev_name,
+			clean ? "clean" : "corrupted",
+			exfat_stat.dir_count, exfat_stat.file_count);
+	if (exfat_stat.error_count)
+		printf("%s: files corrupted %ld, files fixed %ld\n", dev_name,
+			exfat_stat.error_count - exfat_stat.fixed_count,
+			exfat_stat.fixed_count);
+}
+
+int main(int argc, char * const argv[])
+{
+	struct fsck_user_input ui;
+	struct exfat_blk_dev bd;
+	struct pbr *bs = NULL;
+	int c, ret, exit_code;
+	bool version_only = false;
+
+	memset(&ui, 0, sizeof(ui));
+	memset(&bd, 0, sizeof(bd));
+
+	print_level = EXFAT_ERROR;
+
+	if (!setlocale(LC_CTYPE, ""))
+		exfat_err("failed to init locale/codeset\n");
+
+	opterr = 0;
+	while ((c = getopt_long(argc, argv, "arynpbsVvh", opts, NULL)) != EOF) {
+		switch (c) {
+		case 'n':
+			if (ui.options & FSCK_OPTS_REPAIR_ALL)
+				usage(argv[0]);
+			ui.options |= FSCK_OPTS_REPAIR_NO;
+			break;
+		case 'r':
+			if (ui.options & FSCK_OPTS_REPAIR_ALL)
+				usage(argv[0]);
+			ui.options |= FSCK_OPTS_REPAIR_ASK;
+			break;
+		case 'y':
+			if (ui.options & FSCK_OPTS_REPAIR_ALL)
+				usage(argv[0]);
+			ui.options |= FSCK_OPTS_REPAIR_YES;
+			break;
+		case 'a':
+		case 'p':
+			if (ui.options & FSCK_OPTS_REPAIR_ALL)
+				usage(argv[0]);
+			ui.options |= FSCK_OPTS_REPAIR_AUTO;
+			break;
+		case 'b':
+			ui.options |= FSCK_OPTS_IGNORE_BAD_FS_NAME;
+			break;
+		case 's':
+			ui.options |= FSCK_OPTS_RESCUE_CLUS;
+			break;
+		case 'V':
+			version_only = true;
+			break;
+		case 'v':
+			if (print_level < EXFAT_DEBUG)
+				print_level++;
+			break;
+		case '?':
+		case 'h':
+		default:
+			usage(argv[0]);
+		}
+	}
+
+	show_version();
+	if (optind != argc - 1)
+		usage(argv[0]);
+
+	if (version_only)
+		exit(FSCK_EXIT_SYNTAX_ERROR);
+	if (ui.options & FSCK_OPTS_REPAIR_WRITE)
+		ui.ei.writeable = true;
+	else {
+		if (ui.options & (FSCK_OPTS_IGNORE_BAD_FS_NAME |
+				  FSCK_OPTS_RESCUE_CLUS))
+			usage(argv[0]);
+		ui.options |= FSCK_OPTS_REPAIR_NO;
+		ui.ei.writeable = false;
+	}
+
+	exfat_fsck.options = ui.options;
+
+	snprintf(ui.ei.dev_name, sizeof(ui.ei.dev_name), "%s", argv[optind]);
+	ret = exfat_get_blk_dev_info(&ui.ei, &bd);
+	if (ret < 0) {
+		exfat_err("failed to open %s. %d\n", ui.ei.dev_name, ret);
+		return FSCK_EXIT_OPERATION_ERROR;
+	}
+
+	ret = exfat_boot_region_check(&bd, &bs,
+				      ui.options & FSCK_OPTS_IGNORE_BAD_FS_NAME ?
+				      true : false);
+	if (ret)
+		goto err;
+
+	exfat_fsck.exfat = exfat_alloc_exfat(&bd, bs);
+	if (!exfat_fsck.exfat) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	exfat_fsck.buffer_desc = exfat_alloc_buffer(2,
+						    exfat_fsck.exfat->clus_size,
+						    exfat_fsck.exfat->sect_size);
+	if (!exfat_fsck.buffer_desc) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	if ((exfat_fsck.options & FSCK_OPTS_REPAIR_WRITE) &&
+	    exfat_mark_volume_dirty(exfat_fsck.exfat, true)) {
+		ret = -EIO;
+		goto err;
+	}
+
+	exfat_debug("verifying root directory...\n");
+	ret = exfat_root_dir_check(exfat_fsck.exfat);
+	if (ret) {
+		exfat_err("failed to verify root directory.\n");
+		goto out;
+	}
+
+	if (exfat_fsck.options & FSCK_OPTS_RESCUE_CLUS) {
+		ret = exfat_create_file(exfat_fsck.exfat,
+					exfat_fsck.exfat->root,
+					"LOST+FOUND",
+					ATTR_SUBDIR);
+		if (ret) {
+			exfat_err("failed to create lost+found directory\n");
+			goto out;
+		}
+
+		if (fsync(exfat_fsck.exfat->blk_dev->dev_fd) != 0) {
+			ret = -EIO;
+			exfat_err("failed to sync()\n");
+			goto out;
+		}
+	}
+
+	exfat_debug("verifying directory entries...\n");
+	ret = exfat_filesystem_check(&exfat_fsck);
+	if (ret)
+		goto out;
+
+	if (exfat_fsck.options & FSCK_OPTS_RESCUE_CLUS) {
+		rescue_orphan_clusters(&exfat_fsck);
+		exfat_fsck.dirty = true;
+		exfat_fsck.dirty_fat = true;
+	}
+
+	if (exfat_fsck.options & FSCK_OPTS_REPAIR_WRITE) {
+		ret = write_bitmap(&exfat_fsck);
+		if (ret) {
+			exfat_err("failed to write bitmap\n");
+			goto out;
+		}
+	}
+
+	if (ui.ei.writeable && fsync(bd.dev_fd)) {
+		exfat_err("failed to sync\n");
+		ret = -EIO;
+		goto out;
+	}
+	if (exfat_fsck.options & FSCK_OPTS_REPAIR_WRITE)
+		exfat_mark_volume_dirty(exfat_fsck.exfat, false);
+
+out:
+	exfat_show_info(&exfat_fsck, ui.ei.dev_name);
+err:
+	if (ret && ret != -EINVAL)
+		exit_code = FSCK_EXIT_OPERATION_ERROR;
+	else if (ret == -EINVAL ||
+		 exfat_stat.error_count != exfat_stat.fixed_count)
+		exit_code = FSCK_EXIT_ERRORS_LEFT;
+	else if (exfat_fsck.dirty)
+		exit_code = FSCK_EXIT_CORRECTED;
+	else
+		exit_code = FSCK_EXIT_NO_ERRORS;
+
+	if (exfat_fsck.buffer_desc)
+		exfat_free_buffer(exfat_fsck.buffer_desc, 2);
+	if (exfat_fsck.exfat)
+		exfat_free_exfat(exfat_fsck.exfat);
+	close(bd.dev_fd);
+	return exit_code;
+}