Adding upstream version 3.6.upstream/3.6upstream

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

19 files changed, 5112 insertions, 0 deletions

diff --git a/libparted/fs/r/fat/bootsector.c b/libparted/fs/r/fat/bootsector.c
new file mode 100644
index 0000000..85ccc0f
--- /dev/null
+++ b/libparted/fs/r/fat/bootsector.c
@@ -0,0 +1,441 @@
+/*
+    libparted
+    Copyright (C) 1998-2000, 2002, 2004, 2007, 2009-2014, 2019-2023 Free
+    Software Foundation, Inc.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+#include "fat.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+
+/* Reads in the boot sector (superblock), and does a minimum of sanity
+ * checking.  The goals are:
+ *	- to detect fat file systems, even if they are damaged [i.e. not
+ * return an error / throw an exception]
+ *	- to fail detection if there's not enough information for
+ * fat_boot_sector_probe_type() to work (or possibly crash on a divide-by-zero)
+ */
+int
+fat_boot_sector_read (FatBootSector** bsp, const PedGeometry *geom)
+{
+	PED_ASSERT (bsp != NULL);
+	PED_ASSERT (geom != NULL);
+
+	if (!ped_geometry_read_alloc (geom, (void **)bsp, 0, 1))
+		return 0;
+	FatBootSector *bs = *bsp;
+	if (PED_LE16_TO_CPU (bs->boot_sign) != 0xAA55) {
+		ped_exception_throw (PED_EXCEPTION_ERROR, PED_EXCEPTION_CANCEL,
+			_("File system has an invalid signature for a FAT "
+			  "file system."));
+		return 0;
+	}
+
+	if (!bs->sector_size
+            || PED_LE16_TO_CPU (bs->sector_size) % PED_SECTOR_SIZE_DEFAULT) {
+		ped_exception_throw (PED_EXCEPTION_ERROR, PED_EXCEPTION_CANCEL,
+			_("File system has an invalid sector size for a FAT "
+			  "file system."));
+		return 0;
+	}
+
+	if (!bs->cluster_size) {
+		ped_exception_throw (PED_EXCEPTION_ERROR, PED_EXCEPTION_CANCEL,
+			_("File system has an invalid cluster size for a FAT "
+			  "file system."));
+		return 0;
+	}
+
+	if (!bs->reserved) {
+		ped_exception_throw (PED_EXCEPTION_ERROR, PED_EXCEPTION_CANCEL,
+			_("File system has an invalid number of reserved "
+			  "sectors for a FAT file system."));
+		return 0;
+	}
+
+	if (bs->fats < 1 || bs->fats > 4) {
+		ped_exception_throw (PED_EXCEPTION_ERROR, PED_EXCEPTION_CANCEL,
+			_("File system has an invalid number of FATs."));
+		return 0;
+	}
+
+	return 1;
+}
+
+/*
+    Don't trust the FAT12, FAT16 or FAT32 label string.
+ */
+FatType _GL_ATTRIBUTE_PURE
+fat_boot_sector_probe_type (const FatBootSector* bs, const PedGeometry* geom)
+{
+	PedSector	logical_sector_size;
+	PedSector	first_cluster_sector;
+	FatCluster	cluster_count;
+
+	if (!PED_LE16_TO_CPU (bs->dir_entries))
+		return FAT_TYPE_FAT32;
+
+	logical_sector_size = PED_LE16_TO_CPU (bs->sector_size) / 512;
+
+	first_cluster_sector
+		= PED_LE16_TO_CPU (bs->reserved) * logical_sector_size
+		  + 2 * PED_LE16_TO_CPU (bs->fat_length) * logical_sector_size
+		  + PED_LE16_TO_CPU (bs->dir_entries)
+			/ (512 / sizeof (FatDirEntry));
+	cluster_count = (geom->length - first_cluster_sector)
+			/ bs->cluster_size / logical_sector_size;
+	if (cluster_count > MAX_FAT12_CLUSTERS)
+		return FAT_TYPE_FAT16;
+	else
+		return FAT_TYPE_FAT12;
+}
+
+/* Analyses the boot sector, and sticks appropriate numbers in
+   fs->type_specific.
+
+   Note: you need to subtract (2 * cluster_sectors) off cluster offset,
+   because the first cluster is number 2.  (0 and 1 are not real clusters,
+   and referencing them is a bug)
+ */
+int
+fat_boot_sector_analyse (FatBootSector* bs, PedFileSystem* fs)
+{
+	FatSpecific*		fs_info = FAT_SPECIFIC (fs);
+	int			fat_entry_size;
+
+	PED_ASSERT (bs != NULL);
+
+	fs_info->logical_sector_size = PED_LE16_TO_CPU (bs->sector_size) / 512;
+
+	fs_info->sectors_per_track = PED_LE16_TO_CPU (bs->secs_track);
+	fs_info->heads = PED_LE16_TO_CPU (bs->heads);
+	if (fs_info->sectors_per_track < 1 || fs_info->sectors_per_track > 63
+	    || fs_info->heads < 1 || fs_info->heads > 255) {
+		PedCHSGeometry* bios_geom = &fs->geom->dev->bios_geom;
+		int cyl_count = 0;
+
+		if (fs_info->heads > 0 && fs_info->sectors_per_track > 0)
+			cyl_count = fs->geom->dev->length / fs_info->heads
+					/ fs_info->sectors_per_track;
+
+		switch (ped_exception_throw (
+			PED_EXCEPTION_ERROR,
+			PED_EXCEPTION_FIX + PED_EXCEPTION_IGNORE
+			+ PED_EXCEPTION_CANCEL,
+			_("The file system's CHS geometry is (%d, %d, %d), "
+			  "which is invalid.  The partition table's CHS "
+			  "geometry is (%d, %d, %d).  If you select Ignore, "
+			  "the file system's CHS geometry will be left "
+			  "unchanged.  If you select Fix, the file system's "
+			  "CHS geometry will be set to match the partition "
+			  "table's CHS geometry."),
+			 cyl_count, fs_info->heads, fs_info->sectors_per_track,
+			 bios_geom->cylinders, bios_geom->heads,
+			 bios_geom->sectors)) {
+
+		case PED_EXCEPTION_FIX:
+			fs_info->sectors_per_track = bios_geom->sectors;
+			fs_info->heads = bios_geom->heads;
+			bs->secs_track
+				= PED_CPU_TO_LE16 (fs_info->sectors_per_track);
+			bs->heads = PED_CPU_TO_LE16 (fs_info->heads);
+			if (!fat_boot_sector_write (bs, fs))
+				return 0;
+			break;
+
+		case PED_EXCEPTION_CANCEL:
+			return 0;
+
+		case PED_EXCEPTION_IGNORE:
+			break;
+
+                default:
+                        break;
+		}
+	}
+
+	if (bs->sectors)
+		fs_info->sector_count = PED_LE16_TO_CPU (bs->sectors)
+						* fs_info->logical_sector_size;
+	else
+		fs_info->sector_count = PED_LE32_TO_CPU (bs->sector_count)
+						* fs_info->logical_sector_size;
+
+	fs_info->fat_table_count = bs->fats;
+	fs_info->root_dir_entry_count = PED_LE16_TO_CPU (bs->dir_entries);
+	fs_info->fat_offset = PED_LE16_TO_CPU (bs->reserved)
+					* fs_info->logical_sector_size;
+	fs_info->cluster_sectors = bs->cluster_size
+				   * fs_info->logical_sector_size;
+	fs_info->cluster_size = fs_info->cluster_sectors * 512;
+
+	if (fs_info->logical_sector_size == 0) {
+		ped_exception_throw (PED_EXCEPTION_ERROR, PED_EXCEPTION_CANCEL,
+			_("FAT boot sector says logical sector size is 0.  "
+			  "This is weird. "));
+		return 0;
+	}
+	if (fs_info->fat_table_count == 0) {
+		ped_exception_throw (PED_EXCEPTION_ERROR, PED_EXCEPTION_CANCEL,
+			_("FAT boot sector says there are no FAT tables.  This "
+			  "is weird. "));
+		return 0;
+	}
+	if (fs_info->cluster_sectors == 0) {
+		ped_exception_throw (PED_EXCEPTION_ERROR, PED_EXCEPTION_CANCEL,
+			_("FAT boot sector says clusters are 0 sectors.  This "
+			  "is weird. "));
+		return 0;
+	}
+
+	fs_info->fat_type = fat_boot_sector_probe_type (bs, fs->geom);
+	if (fs_info->fat_type == FAT_TYPE_FAT12) {
+		ped_exception_throw (
+			PED_EXCEPTION_NO_FEATURE,
+			PED_EXCEPTION_CANCEL,
+			_("File system is FAT12, which is unsupported."));
+		return 0;
+	}
+	if (fs_info->fat_type == FAT_TYPE_FAT16) {
+		fs_info->fat_sectors = PED_LE16_TO_CPU (bs->fat_length)
+				       * fs_info->logical_sector_size;
+		fs_info->serial_number
+			= PED_LE32_TO_CPU (bs->u.fat16.serial_number);
+		fs_info->root_cluster = 0;
+		fs_info->root_dir_offset
+			= fs_info->fat_offset
+			  + fs_info->fat_sectors * fs_info->fat_table_count;
+		fs_info->root_dir_sector_count
+			= fs_info->root_dir_entry_count * sizeof (FatDirEntry)
+			  / (512 * fs_info->logical_sector_size);
+		fs_info->cluster_offset
+			= fs_info->root_dir_offset
+			  + fs_info->root_dir_sector_count;
+	}
+	if (fs_info->fat_type == FAT_TYPE_FAT32) {
+		fs_info->fat_sectors = PED_LE32_TO_CPU (bs->u.fat32.fat_length)
+					* fs_info->logical_sector_size;
+		fs_info->serial_number
+			= PED_LE32_TO_CPU (bs->u.fat32.serial_number);
+		fs_info->info_sector_offset
+		    = PED_LE16_TO_CPU (fs_info->boot_sector->u.fat32.info_sector)
+			  * fs_info->logical_sector_size;
+		fs_info->boot_sector_backup_offset
+		  = PED_LE16_TO_CPU (fs_info->boot_sector->u.fat32.backup_sector)
+			  * fs_info->logical_sector_size;
+		fs_info->root_cluster
+			= PED_LE32_TO_CPU (bs->u.fat32.root_dir_cluster);
+		fs_info->root_dir_offset = 0;
+		fs_info->root_dir_sector_count = 0;
+		fs_info->cluster_offset
+			= fs_info->fat_offset
+			  + fs_info->fat_sectors * fs_info->fat_table_count;
+	}
+
+	fs_info->cluster_count
+		= (fs_info->sector_count - fs_info->cluster_offset)
+		  / fs_info->cluster_sectors;
+
+	fat_entry_size = fat_table_entry_size (fs_info->fat_type);
+	if (fs_info->cluster_count + 2
+			> fs_info->fat_sectors * 512 / fat_entry_size)
+		fs_info->cluster_count
+			= fs_info->fat_sectors * 512 / fat_entry_size - 2;
+
+	fs_info->dir_entries_per_cluster
+		= fs_info->cluster_size / sizeof (FatDirEntry);
+	return 1;
+}
+
+#ifndef DISCOVER_ONLY
+int
+fat_boot_sector_set_boot_code (FatBootSector** bsp, const PedFileSystem* fs)
+{
+	PED_ASSERT (bsp != NULL);
+	*bsp = ped_malloc (fs->geom->dev->sector_size);
+	FatBootSector *bs = *bsp;
+	PED_ASSERT (bs != NULL);
+
+	memset (bs, 0, 512);
+	memcpy (bs->boot_jump, FAT_BOOT_JUMP, 3);
+	PED_ASSERT (sizeof(FAT_BOOT_CODE) < sizeof(bs->u.fat32.boot_code));
+	strcpy (bs->u.fat32.boot_code, FAT_BOOT_CODE);
+	return 1;
+}
+
+int
+fat_boot_sector_generate (FatBootSector** bsp, const PedFileSystem* fs)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+
+	PED_ASSERT (bsp != NULL);
+	FatBootSector *bs = *bsp;
+	PED_ASSERT (bs != NULL);
+
+	memcpy (bs->system_id, "MSWIN4.1", 8);
+	bs->sector_size = PED_CPU_TO_LE16 (fs_info->logical_sector_size * 512);
+	bs->cluster_size = fs_info->cluster_sectors
+				/ fs_info->logical_sector_size;
+	bs->reserved = PED_CPU_TO_LE16 (fs_info->fat_offset
+					/ fs_info->logical_sector_size);
+	bs->fats = fs_info->fat_table_count;
+
+	bs->dir_entries = (fs_info->fat_type == FAT_TYPE_FAT16)
+			  ? PED_CPU_TO_LE16 (fs_info->root_dir_entry_count)
+			  : 0;
+
+	if (fs_info->sector_count / fs_info->logical_sector_size > 0xffff
+		|| fs_info->fat_type == FAT_TYPE_FAT32) {
+		bs->sectors = 0;
+		bs->sector_count = PED_CPU_TO_LE32 (fs_info->sector_count
+						/ fs_info->logical_sector_size);
+	} else {
+		bs->sectors = PED_CPU_TO_LE16 (fs_info->sector_count
+					       / fs_info->logical_sector_size);
+		bs->sector_count = 0;
+	}
+
+	bs->media = 0xf8;
+
+	bs->secs_track = PED_CPU_TO_LE16 (fs_info->sectors_per_track);
+	bs->heads = PED_CPU_TO_LE16 (fs_info->heads);
+	bs->hidden = PED_CPU_TO_LE32 (fs->geom->start);
+
+	if (fs_info->fat_type == FAT_TYPE_FAT32) {
+		bs->fat_length = 0;
+		bs->u.fat32.fat_length = PED_CPU_TO_LE32 (fs_info->fat_sectors
+						/ fs_info->logical_sector_size);
+		bs->u.fat32.flags = 0;	/* FIXME: what the hell are these? */
+		bs->u.fat32.version = 0;  /* must be 0, for Win98 bootstrap */
+		bs->u.fat32.root_dir_cluster
+			= PED_CPU_TO_LE32 (fs_info->root_cluster);
+		bs->u.fat32.info_sector
+			= PED_CPU_TO_LE16 (fs_info->info_sector_offset
+					   / fs_info->logical_sector_size);
+		bs->u.fat32.backup_sector
+			= PED_CPU_TO_LE16 (fs_info->boot_sector_backup_offset
+					   / fs_info->logical_sector_size);
+
+		bs->u.fat32.drive_num = 0x80;	/* _ALWAYS_ 0x80.  silly DOS */
+
+		memset (bs->u.fat32.empty_1, 0, 12);
+
+		bs->u.fat32.ext_signature = 0x29;
+		bs->u.fat32.serial_number
+			= PED_CPU_TO_LE32 (fs_info->serial_number);
+		memcpy (bs->u.fat32.volume_name, "NO NAME    ", 11);
+		memcpy (bs->u.fat32.fat_name, "FAT32   ", 8);
+	} else {
+		bs->fat_length
+			= PED_CPU_TO_LE16 (fs_info->fat_sectors
+					   / fs_info->logical_sector_size);
+
+		bs->u.fat16.drive_num = 0x80;	/* _ALWAYS_ 0x80.  silly DOS */
+
+		bs->u.fat16.ext_signature = 0x29;
+		bs->u.fat16.serial_number
+			= PED_CPU_TO_LE32 (fs_info->serial_number);
+		memcpy (bs->u.fat16.volume_name, "NO NAME    ", 11);
+		memcpy (bs->u.fat16.fat_name, "FAT16   ", 8);
+	}
+
+	bs->boot_sign = PED_CPU_TO_LE16 (0xaa55);
+
+	return 1;
+}
+
+int
+fat_boot_sector_write (const FatBootSector* bs, PedFileSystem* fs)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+
+	PED_ASSERT (bs != NULL);
+
+	if (!ped_geometry_write (fs->geom, bs, 0, 1))
+		return 0;
+	if (fs_info->fat_type == FAT_TYPE_FAT32) {
+		if (!ped_geometry_write (fs->geom, bs,
+					 fs_info->boot_sector_backup_offset, 1))
+			return 0;
+	}
+	return ped_geometry_sync (fs->geom);
+}
+
+int
+fat_info_sector_read (FatInfoSector** isp, const PedFileSystem* fs)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+	int		status;
+
+	PED_ASSERT (isp != NULL);
+
+	if (!ped_geometry_read_alloc (fs->geom, (void **)isp, fs_info->info_sector_offset, 1))
+		return 0;
+	FatInfoSector *is = *isp;
+	if (PED_LE32_TO_CPU (is->signature_2) != FAT32_INFO_MAGIC2) {
+		status = ped_exception_throw (PED_EXCEPTION_WARNING,
+				PED_EXCEPTION_IGNORE_CANCEL,
+				_("The information sector has the wrong "
+				"signature (%x).  Select cancel for now, "
+				"and send in a bug report.  If you're "
+				"desperate, it's probably safe to ignore."),
+				PED_LE32_TO_CPU (is->signature_2));
+		if (status == PED_EXCEPTION_CANCEL) return 0;
+	}
+	return 1;
+}
+
+int
+fat_info_sector_generate (FatInfoSector** isp, const PedFileSystem* fs)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+
+	PED_ASSERT (isp != NULL);
+	*isp = ped_malloc (fs->geom->dev->sector_size);
+	FatInfoSector *is = *isp;
+
+	fat_table_count_stats (fs_info->fat);
+
+	memset (is, 0, 512);
+
+	is->signature_1 = PED_CPU_TO_LE32 (FAT32_INFO_MAGIC1);
+	is->signature_2 = PED_CPU_TO_LE32 (FAT32_INFO_MAGIC2);
+	is->free_clusters = PED_CPU_TO_LE32 (fs_info->fat->free_cluster_count);
+	is->next_cluster = PED_CPU_TO_LE32 (fs_info->fat->last_alloc);
+	is->signature_3 = PED_CPU_TO_LE16 (FAT32_INFO_MAGIC3);
+
+	return 1;
+}
+
+int
+fat_info_sector_write (const FatInfoSector* is, PedFileSystem *fs)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+
+	PED_ASSERT (is != NULL);
+
+	if (!ped_geometry_write (fs->geom, is, fs_info->info_sector_offset, 1))
+		return 0;
+	return ped_geometry_sync (fs->geom);
+}
+#endif /* !DISCOVER_ONLY */
diff --git a/libparted/fs/r/fat/bootsector.h b/libparted/fs/r/fat/bootsector.h
new file mode 100644
index 0000000..699d6cf
--- /dev/null
+++ b/libparted/fs/r/fat/bootsector.h
@@ -0,0 +1,130 @@
+/*
+    libparted
+    Copyright (C) 1998-2000, 2007, 2009-2014, 2019-2023 Free Software
+    Foundation, Inc.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef PED_FAT_BOOTSECTOR_H
+#define PED_FAT_BOOTSECTOR_H
+
+typedef struct _FatBootSector	FatBootSector;
+typedef struct _FatInfoSector	FatInfoSector;
+
+#include "fat.h"
+
+#define FAT32_INFO_MAGIC1	0x41615252
+#define FAT32_INFO_MAGIC2	0x61417272
+#define FAT32_INFO_MAGIC3	0xaa55
+
+/* stolen from mkdosfs, by Dave Hudson */
+
+#define FAT_BOOT_MESSAGE	\
+"This partition does not have an operating system loader installed on it.\n\r"\
+"Press a key to reboot..."
+
+#define FAT_BOOT_JUMP	"\xeb\x58\x90"		/* jmp	+5a */
+
+#define FAT_BOOT_CODE	"\x0e"			/* push cs */		\
+			"\x1f"			/* pop ds */		\
+			"\xbe\x74\x7e"		/* mov si, offset message */ \
+					/* write_msg_loop: */		\
+			"\xac"			/* lodsb */		\
+			"\x22\xc0"		/* and al, al */	\
+			"\x74\x06"		/* jz done (+8) */	\
+			"\xb4\x0e"		/* mov ah, 0x0e */	\
+			"\xcd\x10"		/* int 0x10 */		\
+			"\xeb\xf5"		/* jmp write_msg_loop */ \
+					/* done: */			\
+			"\xb4\x00"		/* mov ah, 0x00 */	\
+			"\xcd\x16"		/* int 0x16 */		\
+			"\xb4\x00"		/* mov ah, 0x00 */	\
+			"\xcd\x19"		/* int 0x19 */		\
+			"\xeb\xfe"		/* jmp +0 - in case int 0x19 */ \
+						/* doesn't work */	\
+					/* message: */			\
+			FAT_BOOT_MESSAGE
+
+struct __attribute__ ((packed)) _FatBootSector {
+        uint8_t		boot_jump[3];	/* 00: Boot strap short or near jump */
+        uint8_t		system_id[8];	/* 03: system name */
+        uint16_t	sector_size;	/* 0b: bytes per logical sector */
+        uint8_t		cluster_size;	/* 0d: sectors/cluster */
+        uint16_t	reserved;	/* 0e: reserved sectors */
+        uint8_t		fats;		/* 10: number of FATs */
+        uint16_t	dir_entries;	/* 11: number of root directory entries */
+        uint16_t	sectors;	/* 13: if 0, total_sect supersedes */
+        uint8_t		media;		/* 15: media code */
+        uint16_t	fat_length;	/* 16: sectors/FAT for FAT12/16 */
+        uint16_t	secs_track;	/* 18: sectors per track */
+        uint16_t	heads;		/* 1a: number of heads */
+        uint32_t	hidden;		/* 1c: hidden sectors (partition start) */
+        uint32_t	sector_count;	/* 20: no. of sectors (if sectors == 0) */
+
+        union __attribute__ ((packed)) {
+                /* FAT16 fields */
+                struct __attribute__ ((packed)) {
+                        uint8_t		drive_num;	/* 24: */
+                        uint8_t		empty_1;	/* 25: */
+                        uint8_t		ext_signature;	/* 26: always 0x29 */
+                        uint32_t	serial_number;	/* 27: */
+                        uint8_t		volume_name [11];       /* 2b: */
+                        uint8_t		fat_name [8];	/* 36: */
+                        uint8_t		boot_code[448];	/* 3f: Boot code (or message) */
+                } fat16;
+                /* FAT32 fields */
+                struct __attribute__ ((packed)) {
+                        uint32_t	fat_length;	/* 24: size of FAT in sectors */
+                        uint16_t	flags;		/* 28: bit8: fat mirroring, low4: active fat */
+                        uint16_t	version;        /* 2a: minor * 256 + major */
+                        uint32_t	root_dir_cluster;	/* 2c: */
+                        uint16_t	info_sector;    /* 30: */
+                        uint16_t	backup_sector;	/* 32: */
+                        uint8_t		empty_1 [12];	/* 34: */
+                        uint16_t	drive_num;	/* 40: */
+                        uint8_t		ext_signature;	/* 42: always 0x29 */
+                        uint32_t	serial_number;	/* 43: */
+                        uint8_t		volume_name [11];	/* 47: */
+                        uint8_t		fat_name [8];	/* 52: */
+                        uint8_t		boot_code[420];	/* 5a: Boot code (or message) */
+                } fat32;
+        } u;
+
+	uint16_t	boot_sign;	/* 1fe: always 0xAA55 */
+};
+
+struct __attribute__ ((packed)) _FatInfoSector {
+        uint32_t	signature_1;	/* should be 0x41615252 */
+        uint8_t		unused [480];
+        uint32_t	signature_2;	/* should be 0x61417272 */
+        uint32_t	free_clusters;
+        uint32_t	next_cluster;	/* most recently allocated cluster */
+        uint8_t		unused2 [0xe];
+        uint16_t	signature_3;	/* should be 0xaa55 */
+};
+
+int fat_boot_sector_read (FatBootSector** bs, const PedGeometry* geom);
+FatType fat_boot_sector_probe_type (const FatBootSector* bs,
+				    const PedGeometry* geom);
+int fat_boot_sector_analyse (FatBootSector* bs, PedFileSystem* fs);
+int fat_boot_sector_set_boot_code (FatBootSector** bs, const PedFileSystem* fs);
+int fat_boot_sector_generate (FatBootSector** bs, const PedFileSystem* fs);
+int fat_boot_sector_write (const FatBootSector* bs, PedFileSystem* fs);
+
+int fat_info_sector_read (FatInfoSector** is, const PedFileSystem* fs);
+int fat_info_sector_generate (FatInfoSector** is, const PedFileSystem* fs);
+int fat_info_sector_write (const FatInfoSector* is, PedFileSystem* fs);
+
+#endif /* PED_FAT_BOOTSECTOR_H */
diff --git a/libparted/fs/r/fat/calc.c b/libparted/fs/r/fat/calc.c
new file mode 100644
index 0000000..4ba1030
--- /dev/null
+++ b/libparted/fs/r/fat/calc.c
@@ -0,0 +1,433 @@
+/*
+    libparted
+    Copyright (C) 1998-2000, 2002, 2007, 2009-2014, 2019-2023 Free Software
+    Foundation, Inc.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+#include "fat.h"
+
+#ifndef DISCOVER_ONLY
+
+/* returns the minimum size of clusters for a given file system type */
+PedSector _GL_ATTRIBUTE_CONST
+fat_min_cluster_size (FatType fat_type) {
+	switch (fat_type) {
+		case FAT_TYPE_FAT12: return 1;
+		case FAT_TYPE_FAT16: return 1024/512;
+		case FAT_TYPE_FAT32: return 4096/512;
+	}
+	return 0;
+}
+
+static PedSector _GL_ATTRIBUTE_CONST
+_smallest_power2_over (PedSector ceiling)
+{
+	PedSector	result = 1;
+
+	while (result < ceiling)
+		result *= 2;
+
+	return result;
+}
+
+/* returns the minimum size of clusters for a given file system type */
+PedSector _GL_ATTRIBUTE_CONST
+fat_recommend_min_cluster_size (FatType fat_type, PedSector size) {
+	switch (fat_type) {
+		case FAT_TYPE_FAT12: return 1;
+		case FAT_TYPE_FAT16: return fat_min_cluster_size(fat_type);
+		case FAT_TYPE_FAT32:
+			return PED_MAX(_smallest_power2_over(size
+						/ MAX_FAT32_CLUSTERS),
+				       fat_min_cluster_size (fat_type));
+	}
+	return 0;
+}
+
+/* returns the maxmimum size of clusters for a given file system type */
+PedSector _GL_ATTRIBUTE_CONST
+fat_max_cluster_size (FatType fat_type) {
+	switch (fat_type) {
+		case FAT_TYPE_FAT12: return 1;	/* dunno... who cares? */
+		case FAT_TYPE_FAT16: return 65536/512;
+		case FAT_TYPE_FAT32: return 65536/512;
+	}
+	return 0;
+}
+
+/* returns the minimum number of clusters for a given file system type */
+FatCluster _GL_ATTRIBUTE_CONST
+fat_min_cluster_count (FatType fat_type) {
+	switch (fat_type) {
+		case FAT_TYPE_FAT12:
+		case FAT_TYPE_FAT16:
+			return fat_max_cluster_count (fat_type) / 2;
+
+		case FAT_TYPE_FAT32: return 0xfff0;
+	}
+	return 0;
+}
+
+/* returns the maximum number of clusters for a given file system type */
+FatCluster _GL_ATTRIBUTE_CONST
+fat_max_cluster_count (FatType fat_type) {
+	switch (fat_type) {
+		case FAT_TYPE_FAT12: return 0xff0;
+		case FAT_TYPE_FAT16: return 0xfff0;
+		case FAT_TYPE_FAT32: return 0x0ffffff0;
+	}
+	return 0;
+}
+
+/* what is this supposed to be?  What drugs are M$ on?  (Can I have some? :-) */
+PedSector _GL_ATTRIBUTE_CONST
+fat_min_reserved_sector_count (FatType fat_type)
+{
+	return (fat_type == FAT_TYPE_FAT32) ? 32 : 1;
+}
+
+int
+fat_check_resize_geometry (const PedFileSystem* fs,
+			   const PedGeometry* geom,
+			   PedSector new_cluster_sectors,
+			   FatCluster new_cluster_count)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+	PedSector	free_space;
+	PedSector	min_free_space;
+	PedSector	total_space;
+	PedSector	new_total_space;
+	PedSector	dir_space;
+
+	PED_ASSERT (geom != NULL);
+
+	dir_space = fs_info->total_dir_clusters * fs_info->cluster_sectors;
+	free_space = fs_info->fat->free_cluster_count
+			* fs_info->cluster_sectors;
+	total_space = fs_info->fat->cluster_count * fs_info->cluster_sectors;
+	new_total_space = new_cluster_count * new_cluster_sectors;
+	min_free_space = total_space - new_total_space + dir_space;
+
+	PED_ASSERT (new_cluster_count
+		    <= fat_max_cluster_count (FAT_TYPE_FAT32));
+
+	if (free_space < min_free_space) {
+		char* needed = ped_unit_format (geom->dev, min_free_space);
+		char* have = ped_unit_format (geom->dev, free_space);
+		ped_exception_throw (
+			PED_EXCEPTION_ERROR,
+			PED_EXCEPTION_CANCEL,
+			_("You need %s of free disk space to shrink this "
+			  "partition to this size.  Currently, only %s is "
+			  "free."),
+			needed, have);
+		free (needed);
+		free (have);
+		return 0;
+	}
+
+	return 1;
+}
+
+
+/******************************************************************************/
+
+/* DO NOT EDIT THIS ALGORITHM!
+ * As far as I can tell, this is the same algorithm used by Microsoft to
+ * calculate the size of the file allocaion tables, and the number of clusters.
+ * I have not verified this by dissassembling Microsoft code - I came to this
+ * conclusion by empirical analysis (i.e. trial and error - this was HORRIBLE).
+ *
+ * If you think this code makes no sense, then you are right.  I will restrain
+ * the urge to inflict serious bodily harm on Microsoft people.
+ */
+
+static int
+entries_per_sector (FatType fat_type)
+{
+	switch (fat_type) {
+		case FAT_TYPE_FAT12:
+			return 512 * 3 / 2;
+		case FAT_TYPE_FAT16:
+			return 512 / 2;
+		case FAT_TYPE_FAT32:
+			return 512 / 4;
+	}
+	return 0;
+}
+
+static int
+calc_sizes (PedSector size, PedSector align, FatType fat_type,
+	    PedSector root_dir_sectors, PedSector cluster_sectors,
+	    FatCluster* out_cluster_count, PedSector* out_fat_size)
+{
+	PedSector	data_fat_space; /* space available to clusters + FAT */
+	PedSector	fat_space;	/* space taken by each FAT */
+	PedSector	cluster_space;	/* space taken by clusters */
+	FatCluster	cluster_count;
+	int		i;
+
+	PED_ASSERT (out_cluster_count != NULL);
+	PED_ASSERT (out_fat_size != NULL);
+
+	data_fat_space = size - fat_min_reserved_sector_count (fat_type)
+			 - align;
+	if (fat_type == FAT_TYPE_FAT16)
+		data_fat_space -= root_dir_sectors;
+
+	fat_space = 0;
+	for (i = 0; i < 2; i++) {
+		if (fat_type == FAT_TYPE_FAT32)
+			cluster_space = data_fat_space - fat_space;
+		else
+			cluster_space = data_fat_space - 2 * fat_space;
+
+		cluster_count = cluster_space / cluster_sectors;
+		fat_space = ped_div_round_up (cluster_count + 2,
+					      entries_per_sector (fat_type));
+	}
+
+	cluster_space = data_fat_space - 2 * fat_space;
+	cluster_count = cluster_space / cluster_sectors;
+
+	/* looks like this should be part of the loop condition?
+	 * Need to build the Big Table TM again to check
+	 */
+	if (fat_space < ped_div_round_up (cluster_count + 2,
+				          entries_per_sector (fat_type))) {
+		fat_space = ped_div_round_up (cluster_count + 2,
+					      entries_per_sector (fat_type));
+	}
+
+	if (cluster_count > fat_max_cluster_count (fat_type)
+	    || cluster_count < fat_min_cluster_count (fat_type))
+		return 0;
+
+	*out_cluster_count = cluster_count;
+	*out_fat_size = fat_space;
+
+	return 1;
+}
+
+/****************************************************************************/
+
+int
+fat_calc_sizes (PedSector size, PedSector align, FatType fat_type,
+		PedSector root_dir_sectors,
+		PedSector* out_cluster_sectors, FatCluster* out_cluster_count,
+		PedSector* out_fat_size)
+{
+	PedSector	cluster_sectors;
+
+	PED_ASSERT (out_cluster_sectors != NULL);
+	PED_ASSERT (out_cluster_count != NULL);
+	PED_ASSERT (out_fat_size != NULL);
+
+	for (cluster_sectors = fat_recommend_min_cluster_size (fat_type, size);
+	     cluster_sectors <= fat_max_cluster_size (fat_type);
+	     cluster_sectors *= 2) {
+		if (calc_sizes (size, align, fat_type, root_dir_sectors,
+				cluster_sectors,
+			        out_cluster_count, out_fat_size)) {
+			*out_cluster_sectors = cluster_sectors;
+			return 1;
+		}
+	}
+
+	for (cluster_sectors = fat_recommend_min_cluster_size (fat_type, size);
+	     cluster_sectors >= fat_min_cluster_size (fat_type);
+	     cluster_sectors /= 2) {
+		if (calc_sizes (size, align, fat_type, root_dir_sectors,
+				cluster_sectors,
+			        out_cluster_count, out_fat_size)) {
+			*out_cluster_sectors = cluster_sectors;
+			return 1;
+		}
+	}
+
+	/* only make the cluster size really small (<4k) if a bigger one is
+	 * isn't possible.  Windows never makes FS's like this, but it
+	 * seems to work...  (do more tests!)
+	 */
+	for (cluster_sectors = 4; cluster_sectors > 0; cluster_sectors /= 2) {
+		if (calc_sizes (size, align, fat_type, root_dir_sectors,
+				cluster_sectors,
+				out_cluster_count, out_fat_size)) {
+			*out_cluster_sectors = cluster_sectors;
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+/* Same as fat_calc_sizes, except it only attempts to match a particular
+ * cluster size.  This is useful, because the FAT resizer can only shrink the
+ * cluster size.
+ */
+int
+fat_calc_resize_sizes (
+	const PedGeometry* geom,
+	PedSector align,
+	FatType fat_type,
+	PedSector root_dir_sectors,
+	PedSector cluster_sectors,
+	PedSector* out_cluster_sectors,
+	FatCluster* out_cluster_count,
+	PedSector* out_fat_size)
+{
+	PED_ASSERT (geom != NULL);
+	PED_ASSERT (out_cluster_sectors != NULL);
+	PED_ASSERT (out_cluster_count != NULL);
+	PED_ASSERT (out_fat_size != NULL);
+
+/* libparted can only reduce the cluster size at this point */
+	for (*out_cluster_sectors = cluster_sectors;
+	     *out_cluster_sectors >= fat_min_cluster_size (fat_type);
+	     *out_cluster_sectors /= 2) {
+		if (calc_sizes (geom->length, align, fat_type, root_dir_sectors,
+				*out_cluster_sectors,
+				out_cluster_count, out_fat_size))
+			return 1;
+	}
+	return 0;
+}
+
+/*  Calculates the number of sectors needed to be added to cluster_offset,
+    to make the cluster on the new file system match up with the ones
+    on the old file system.
+	However, some space is reserved by fat_calc_resize_sizes() and
+    friends, to allow room for this space.  If too much of this space is left
+    over, everyone will complain, so we have to be greedy, and use it all up...
+ */
+PedSector _GL_ATTRIBUTE_PURE
+fat_calc_align_sectors (const PedFileSystem* new_fs,
+			const PedFileSystem* old_fs)
+{
+	FatSpecific*	old_fs_info = FAT_SPECIFIC (old_fs);
+	FatSpecific*	new_fs_info = FAT_SPECIFIC (new_fs);
+	PedSector	raw_old_meta_data_end;
+	PedSector	new_meta_data_size;
+	PedSector	min_new_meta_data_end;
+	PedSector	new_data_size;
+	PedSector	new_clusters_size;
+	PedSector	align;
+
+	new_meta_data_size
+		= fat_min_reserved_sector_count (new_fs_info->fat_type)
+		  + new_fs_info->fat_sectors * 2;
+
+	if (new_fs_info->fat_type == FAT_TYPE_FAT16)
+		new_meta_data_size += new_fs_info->root_dir_sector_count;
+
+	raw_old_meta_data_end = old_fs->geom->start
+				 + old_fs_info->cluster_offset;
+
+	min_new_meta_data_end = new_fs->geom->start + new_meta_data_size;
+
+	if (raw_old_meta_data_end > min_new_meta_data_end)
+		align = (raw_old_meta_data_end - min_new_meta_data_end)
+			% new_fs_info->cluster_sectors;
+	else
+		align = (new_fs_info->cluster_sectors
+		         - (   (min_new_meta_data_end - raw_old_meta_data_end)
+				% new_fs_info->cluster_sectors   ))
+			% new_fs_info->cluster_sectors;
+
+	new_data_size = new_fs->geom->length - new_meta_data_size;
+	new_clusters_size = new_fs_info->cluster_count
+				* new_fs_info->cluster_sectors;
+
+	while (new_clusters_size + align + new_fs_info->cluster_sectors
+			<= new_data_size)
+		align += new_fs_info->cluster_sectors;
+
+	return align;
+}
+
+int _GL_ATTRIBUTE_PURE
+fat_is_sector_in_clusters (const PedFileSystem* fs, PedSector sector)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+
+	return sector >= fs_info->cluster_offset
+	       && sector < fs_info->cluster_offset
+	      		   + fs_info->cluster_sectors * fs_info->cluster_count;
+}
+
+FatFragment _GL_ATTRIBUTE_PURE
+fat_cluster_to_frag (const PedFileSystem* fs, FatCluster cluster)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+
+	PED_ASSERT (cluster >= 2 && cluster < fs_info->cluster_count + 2);
+
+	return (cluster - 2) * fs_info->cluster_frags;
+}
+
+FatCluster _GL_ATTRIBUTE_PURE
+fat_frag_to_cluster (const PedFileSystem* fs, FatFragment frag)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+
+	PED_ASSERT (frag >= 0 && frag < fs_info->frag_count);
+
+	return frag / fs_info->cluster_frags + 2;
+}
+
+PedSector _GL_ATTRIBUTE_PURE
+fat_frag_to_sector (const PedFileSystem* fs, FatFragment frag)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+
+	PED_ASSERT (frag >= 0 && frag < fs_info->frag_count);
+
+	return frag * fs_info->frag_sectors + fs_info->cluster_offset;
+}
+
+FatFragment _GL_ATTRIBUTE_PURE
+fat_sector_to_frag (const PedFileSystem* fs, PedSector sector)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+
+	PED_ASSERT (sector >= fs_info->cluster_offset);
+
+	return (sector - fs_info->cluster_offset) / fs_info->frag_sectors;
+}
+
+PedSector _GL_ATTRIBUTE_PURE
+fat_cluster_to_sector (const PedFileSystem* fs, FatCluster cluster)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+
+	PED_ASSERT (cluster >= 2 && cluster < fs_info->cluster_count + 2);
+
+	return (cluster - 2) * fs_info->cluster_sectors
+		+ fs_info->cluster_offset;
+}
+
+FatCluster _GL_ATTRIBUTE_PURE
+fat_sector_to_cluster (const PedFileSystem* fs, PedSector sector)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+
+	PED_ASSERT (sector >= fs_info->cluster_offset);
+
+	return (sector - fs_info->cluster_offset) / fs_info->cluster_sectors
+		+ 2;
+}
+#endif /* !DISCOVER_ONLY */
diff --git a/libparted/fs/r/fat/calc.h b/libparted/fs/r/fat/calc.h
new file mode 100644
index 0000000..d4884c1
--- /dev/null
+++ b/libparted/fs/r/fat/calc.h
@@ -0,0 +1,77 @@
+/*
+    libparted
+    Copyright (C) 1998-2000, 2007, 2009-2014, 2019-2023 Free Software
+    Foundation, Inc.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef PED_FAT_CALC_H
+#define PED_FAT_CALC_H
+
+extern PedSector fat_min_cluster_size (FatType fat_type);
+extern PedSector fat_max_cluster_size (FatType fat_type);
+extern FatCluster fat_min_cluster_count (FatType fat_type);
+extern FatCluster fat_max_cluster_count (FatType fat_type);
+
+extern PedSector fat_min_reserved_sector_count (FatType fat_type);
+
+extern int fat_check_resize_geometry (const PedFileSystem* fs,
+	       			      const PedGeometry* geom,
+				      PedSector new_cluster_sectors,
+				      FatCluster new_cluster_count);
+
+extern int fat_calc_sizes (PedSector size,
+			   PedSector align,
+			   FatType fat_type,
+			   PedSector root_dir_sectors,
+			   PedSector* out_cluster_sectors,
+			   FatCluster* out_cluster_count,
+			   PedSector* out_fat_size);
+
+extern int fat_calc_resize_sizes (const PedGeometry* geom,
+				  PedSector align,
+				  FatType fat_type,
+				  PedSector root_dir_sectors,
+				  PedSector cluster_sectors,
+				  PedSector* out_cluster_sectors,
+				  FatCluster* out_cluster_count,
+				  PedSector* out_fat_size);
+
+extern PedSector
+fat_calc_align_sectors (const PedFileSystem* new_fs,
+			const PedFileSystem* old_fs);
+
+extern int
+fat_is_sector_in_clusters (const PedFileSystem* fs, PedSector sector);
+
+extern FatFragment
+fat_cluster_to_frag (const PedFileSystem* fs, FatCluster cluster);
+
+extern FatCluster
+fat_frag_to_cluster (const PedFileSystem* fs, FatFragment frag);
+
+extern PedSector
+fat_frag_to_sector (const PedFileSystem* fs, FatFragment frag);
+
+extern FatFragment
+fat_sector_to_frag (const PedFileSystem* fs, PedSector sector);
+
+extern PedSector
+fat_cluster_to_sector (const PedFileSystem* fs, FatCluster cluster);
+
+extern FatCluster
+fat_sector_to_cluster (const PedFileSystem* fs, PedSector sector);
+
+#endif /* PED_FAT_CALC_H */
diff --git a/libparted/fs/r/fat/clstdup.c b/libparted/fs/r/fat/clstdup.c
new file mode 100644
index 0000000..6a3054f
--- /dev/null
+++ b/libparted/fs/r/fat/clstdup.c
@@ -0,0 +1,423 @@
+/*
+    libparted
+    Copyright (C) 1998-2001, 2007, 2009-2014, 2019-2023 Free Software
+    Foundation, Inc.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+#include <string.h>
+
+#include "fat.h"
+
+#ifndef DISCOVER_ONLY
+
+static int
+needs_duplicating (const FatOpContext* ctx, FatFragment frag)
+{
+	FatSpecific*	old_fs_info = FAT_SPECIFIC (ctx->old_fs);
+	FatCluster	cluster = fat_frag_to_cluster (ctx->old_fs, frag);
+	FatClusterFlag	flag;
+
+	PED_ASSERT (cluster >= 2 && cluster < old_fs_info->cluster_count + 2);
+
+	flag = fat_get_fragment_flag (ctx->old_fs, frag);
+	switch (flag) {
+	case FAT_FLAG_FREE:
+		return 0;
+
+	case FAT_FLAG_DIRECTORY:
+		return 1;
+
+	case FAT_FLAG_FILE:
+		return fat_op_context_map_static_fragment (ctx, frag) == -1;
+
+	case FAT_FLAG_BAD:
+		return 0;
+	}
+
+	return 0;
+}
+
+static int
+search_next_fragment (FatOpContext* ctx)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (ctx->old_fs);
+
+	for (; ctx->buffer_offset < fs_info->frag_count; ctx->buffer_offset++) {
+		if (needs_duplicating (ctx, ctx->buffer_offset))
+			return 1;
+	}
+	return 0;	/* all done! */
+}
+
+static int
+read_marked_fragments (FatOpContext* ctx, FatFragment length)
+{
+	FatSpecific*		fs_info = FAT_SPECIFIC (ctx->old_fs);
+	int			status;
+	FatFragment		i;
+
+	ped_exception_fetch_all ();
+	status = fat_read_fragments (ctx->old_fs, fs_info->buffer,
+				     ctx->buffer_offset, length);
+	ped_exception_leave_all ();
+	if (status)
+		return 1;
+
+	ped_exception_catch ();
+
+/* something bad happened, so read fragments one by one.  (The error may
+   have occurred on an unused fragment: who cares) */
+	for (i = 0; i < length; i++) {
+		if (ctx->buffer_map [i]) {
+			if (!fat_read_fragment (ctx->old_fs,
+			      fs_info->buffer + i * fs_info->frag_size,
+			      ctx->buffer_offset + i))
+				return 0;
+		}
+	}
+
+	return 1;
+}
+
+static int
+fetch_fragments (FatOpContext* ctx)
+{
+	FatSpecific*	old_fs_info = FAT_SPECIFIC (ctx->old_fs);
+	FatFragment	fetch_length = 0;
+	FatFragment	frag;
+
+	for (frag = 0; frag < ctx->buffer_frags; frag++)
+		ctx->buffer_map [frag] = -1;
+
+	for (frag = 0;
+	     frag < ctx->buffer_frags
+		&& ctx->buffer_offset + frag < old_fs_info->frag_count;
+	     frag++) {
+		if (needs_duplicating (ctx, ctx->buffer_offset + frag)) {
+			ctx->buffer_map [frag] = 1;
+			fetch_length = frag + 1;
+		}
+	}
+
+	if (!read_marked_fragments (ctx, fetch_length))
+		return 0;
+
+	return 1;
+}
+
+/*****************************************************************************
+ * here starts the write code.  All assumes that ctx->buffer_map [first] and
+ * ctx->buffer_map [last] are occupied by fragments that need to be duplicated.
+ *****************************************************************************/
+
+/* finds the first fragment that is not going to get overwritten (that needs to
+   get read in) */
+static FatFragment _GL_ATTRIBUTE_PURE
+get_first_underlay (const FatOpContext* ctx, int first, int last)
+{
+	int		old;
+	FatFragment	new;
+
+	PED_ASSERT (first <= last);
+
+	new = ctx->buffer_map [first];
+	for (old = first + 1; old <= last; old++) {
+		if (ctx->buffer_map [old] == -1)
+			continue;
+		new++;
+		if (ctx->buffer_map [old] != new)
+			return new;
+	}
+	return -1;
+}
+
+/* finds the last fragment that is not going to get overwritten (that needs to
+   get read in) */
+static FatFragment _GL_ATTRIBUTE_PURE
+get_last_underlay (const FatOpContext* ctx, int first, int last)
+{
+	int		old;
+	FatFragment	new;
+
+	PED_ASSERT (first <= last);
+
+	new = ctx->buffer_map [last];
+	for (old = last - 1; old >= first; old--) {
+		if (ctx->buffer_map [old] == -1)
+			continue;
+		new--;
+		if (ctx->buffer_map [old] != new)
+			return new;
+	}
+	return -1;
+}
+
+/* "underlay" refers to the "static" fragments, that remain unchanged.
+ * when writing large chunks at a time, we don't want to clobber these,
+ * so we read them in, and write them back again.  MUCH quicker that way.
+ */
+static int
+quick_group_write_read_underlay (FatOpContext* ctx, int first, int last)
+{
+	FatSpecific*	new_fs_info = FAT_SPECIFIC (ctx->new_fs);
+	FatFragment	first_underlay;
+	FatFragment	last_underlay;
+	FatFragment	underlay_length;
+
+	PED_ASSERT (first <= last);
+
+	first_underlay = get_first_underlay (ctx, first, last);
+	if (first_underlay == -1)
+		return 1;
+	last_underlay = get_last_underlay (ctx, first, last);
+
+	PED_ASSERT (first_underlay <= last_underlay);
+
+	underlay_length = last_underlay - first_underlay + 1;
+	if (!fat_read_fragments (ctx->new_fs,
+				new_fs_info->buffer
+				   + (first_underlay - ctx->buffer_map [first])
+					* new_fs_info->frag_size,
+				first_underlay,
+				underlay_length))
+		return 0;
+	return 1;
+}
+
+/* quick_group_write() makes no attempt to recover from errors - just
+ * does things fast.  If there is an error, slow_group_write() is
+ * called.
+ *    Note: we do syncing writes, to make sure there isn't any
+ * error writing out.  It's rather difficult recovering from errors
+ * further on.
+ */
+static int
+quick_group_write (FatOpContext* ctx, int first, int last)
+{
+	FatSpecific*		old_fs_info = FAT_SPECIFIC (ctx->old_fs);
+	FatSpecific*		new_fs_info = FAT_SPECIFIC (ctx->new_fs);
+	int			active_length;
+	int			i;
+	int			offset;
+
+	PED_ASSERT (first <= last);
+
+	ped_exception_fetch_all ();
+	if (!quick_group_write_read_underlay (ctx, first, last))
+		goto error;
+
+	for (i = first; i <= last; i++) {
+		if (ctx->buffer_map [i] == -1)
+			continue;
+
+		offset = ctx->buffer_map [i] - ctx->buffer_map [first];
+		memcpy (new_fs_info->buffer + offset * new_fs_info->frag_size,
+			old_fs_info->buffer + i * new_fs_info->frag_size,
+			new_fs_info->frag_size);
+	}
+
+	active_length = ctx->buffer_map [last] - ctx->buffer_map [first] + 1;
+	if (!fat_write_sync_fragments (ctx->new_fs, new_fs_info->buffer,
+				       ctx->buffer_map [first], active_length))
+		goto error;
+
+	ped_exception_leave_all ();
+	return 1;
+
+error:
+	ped_exception_catch ();
+	ped_exception_leave_all ();
+	return 0;
+}
+
+/* Writes fragments out, one at a time, avoiding errors on redundant writes
+ * on damaged parts of the disk we already know about.  If there's an error
+ * on one of the required fragments, it gets marked as bad, and a replacement
+ * is found.
+ */
+static int
+slow_group_write (FatOpContext* ctx, int first, int last)
+{
+	FatSpecific*		old_fs_info = FAT_SPECIFIC (ctx->old_fs);
+	FatSpecific*		new_fs_info = FAT_SPECIFIC (ctx->new_fs);
+	int			i;
+
+	PED_ASSERT (first <= last);
+
+	for (i = first; i <= last; i++) {
+		if (ctx->buffer_map [i] == -1)
+			continue;
+
+		while (!fat_write_sync_fragment (ctx->new_fs,
+			      old_fs_info->buffer + i * old_fs_info->frag_size,
+			      ctx->buffer_map [i])) {
+			fat_table_set_bad (new_fs_info->fat,
+					   ctx->buffer_map [i]);
+			ctx->buffer_map [i] = fat_table_alloc_cluster
+						(new_fs_info->fat);
+			if (ctx->buffer_map [i] == 0)
+				return 0;
+		}
+	}
+	return 1;
+}
+
+static int
+update_remap (FatOpContext* ctx, int first, int last)
+{
+	int		i;
+
+	PED_ASSERT (first <= last);
+
+	for (i = first; i <= last; i++) {
+		if (ctx->buffer_map [i] == -1)
+			continue;
+		ctx->remap [ctx->buffer_offset + i] = ctx->buffer_map [i];
+	}
+
+	return 1;
+}
+
+static int
+group_write (FatOpContext* ctx, int first, int last)
+{
+	PED_ASSERT (first <= last);
+
+	if (!quick_group_write (ctx, first, last)) {
+		if (!slow_group_write (ctx, first, last))
+			return 0;
+	}
+	if (!update_remap (ctx, first, last))
+		return 0;
+	return 1;
+}
+
+/* assumes fragment size and new_fs's cluster size are equal */
+static int
+write_fragments (FatOpContext* ctx)
+{
+	FatSpecific*		old_fs_info = FAT_SPECIFIC (ctx->old_fs);
+	FatSpecific*		new_fs_info = FAT_SPECIFIC (ctx->new_fs);
+	int			group_start;
+	int			group_end = -1;	/* shut gcc up! */
+	FatFragment		mapped_length;
+	FatFragment		i;
+	FatCluster		new_cluster;
+
+	PED_ASSERT (ctx->buffer_offset < old_fs_info->frag_count);
+
+	group_start = -1;
+	for (i = 0; i < ctx->buffer_frags; i++) {
+		if (ctx->buffer_map [i] == -1)
+			continue;
+
+		ctx->frags_duped++;
+
+		new_cluster = fat_table_alloc_cluster (new_fs_info->fat);
+		if (!new_cluster)
+			return 0;
+		fat_table_set_eof (new_fs_info->fat, new_cluster);
+		ctx->buffer_map [i] = fat_cluster_to_frag (ctx->new_fs,
+							   new_cluster);
+
+		if (group_start == -1)
+			group_start = group_end = i;
+
+		PED_ASSERT (ctx->buffer_map [i]
+				>= ctx->buffer_map [group_start]);
+
+		mapped_length = ctx->buffer_map [i]
+				- ctx->buffer_map [group_start] + 1;
+		if (mapped_length <= ctx->buffer_frags) {
+			group_end = i;
+		} else {
+			/* ran out of room in the buffer, so write this group,
+			 * and start a new one...
+			 */
+			if (!group_write (ctx, group_start, group_end))
+				return 0;
+			group_start = group_end = i;
+		}
+	}
+
+	PED_ASSERT (group_start != -1);
+
+	if (!group_write (ctx, group_start, group_end))
+		return 0;
+	return 1;
+}
+
+/*  default all fragments to unmoved
+ */
+static void
+init_remap (FatOpContext* ctx)
+{
+	FatSpecific*		old_fs_info = FAT_SPECIFIC (ctx->old_fs);
+	FatFragment		i;
+
+	for (i = 0; i < old_fs_info->frag_count; i++)
+		ctx->remap[i] = fat_op_context_map_static_fragment (ctx, i);
+}
+
+static FatFragment
+count_frags_to_dup (FatOpContext* ctx)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (ctx->old_fs);
+	FatFragment	i;
+	FatFragment	total;
+
+	total = 0;
+
+	for (i = 0; i < fs_info->frag_count; i++) {
+		if (needs_duplicating (ctx, i))
+			total++;
+	}
+
+	return total;
+}
+
+/*  duplicates unreachable file clusters, and all directory clusters
+ */
+int
+fat_duplicate_clusters (FatOpContext* ctx, PedTimer* timer)
+{
+	FatFragment	total_frags_to_dup;
+
+	init_remap (ctx);
+	total_frags_to_dup = count_frags_to_dup (ctx);
+
+	ped_timer_reset (timer);
+	ped_timer_set_state_name (timer, "moving data");
+
+	ctx->buffer_offset = 0;
+	ctx->frags_duped = 0;
+	while (search_next_fragment (ctx)) {
+		ped_timer_update (
+			timer, 1.0 * ctx->frags_duped / total_frags_to_dup);
+
+		if (!fetch_fragments (ctx))
+			return 0;
+		if (!write_fragments (ctx))
+			return 0;
+		ctx->buffer_offset += ctx->buffer_frags;
+	}
+
+	ped_timer_update (timer, 1.0);
+	return 1;
+}
+
+#endif /* !DISCOVER_ONLY */
diff --git a/libparted/fs/r/fat/clstdup.h b/libparted/fs/r/fat/clstdup.h
new file mode 100644
index 0000000..23e51b4
--- /dev/null
+++ b/libparted/fs/r/fat/clstdup.h
@@ -0,0 +1,28 @@
+/*
+    libparted
+    Copyright (C) 1999, 2007, 2009-2014, 2019-2023 Free Software Foundation,
+    Inc.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef PED_FAT_CLSTDUP_H_INCLUDED
+#define PED_FAT_CLSTDUP_H_INCLUDED
+
+#include "context.h"
+
+/* the big important one :-) */
+extern int fat_duplicate_clusters (FatOpContext* ctx, PedTimer* timer);
+
+#endif /* PED_FAT_CLSTDUP_H_INCLUDED */
diff --git a/libparted/fs/r/fat/context.c b/libparted/fs/r/fat/context.c
new file mode 100644
index 0000000..c782323
--- /dev/null
+++ b/libparted/fs/r/fat/context.c
@@ -0,0 +1,261 @@
+/*
+    libparted
+    Copyright (C) 1998-2000, 2007, 2009-2014, 2019-2023 Free Software
+    Foundation, Inc.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+#include <string.h>
+
+#include "fat.h"
+
+#ifndef DISCOVER_ONLY
+
+/* Note: this deals with file system start and end sectors, even if the physical
+ * devices are different (eg for fat_copy())  Perhaps this is a hack, but it
+ * works ;-)
+ */
+static int
+calc_deltas (FatOpContext* ctx)
+{
+	PedFileSystem*	old_fs = ctx->old_fs;
+	PedFileSystem*	new_fs = ctx->new_fs;
+	FatSpecific*	old_fs_info = FAT_SPECIFIC (old_fs);
+	FatSpecific*	new_fs_info = FAT_SPECIFIC (new_fs);
+	PedSector	old_cluster_ofs;
+	PedSector	new_cluster_ofs;
+	PedSector	sector_delta;
+
+	old_cluster_ofs = old_fs->geom->start + old_fs_info->cluster_offset;
+	new_cluster_ofs = new_fs->geom->start + new_fs_info->cluster_offset;
+
+	if (new_cluster_ofs > old_cluster_ofs) {
+		ctx->start_move_dir = FAT_DIR_FORWARD;
+		sector_delta = new_cluster_ofs - old_cluster_ofs;
+	} else {
+		ctx->start_move_dir = FAT_DIR_BACKWARD;
+		sector_delta = old_cluster_ofs - new_cluster_ofs;
+	}
+
+	if (sector_delta % new_fs_info->cluster_sectors) {
+		ped_exception_throw (
+			PED_EXCEPTION_BUG, PED_EXCEPTION_CANCEL,
+			_("Cluster start delta = %d, which is not a multiple "
+			  "of the cluster size %d."),
+			(int) sector_delta,
+			(int) new_fs_info->cluster_sectors);
+		return 0;
+	}
+
+	ctx->start_move_delta = sector_delta / ctx->frag_sectors;
+
+#ifdef PED_VERBOSE
+	printf ("Start move delta is: %d %s.\n",
+		(int) ctx->start_move_delta,
+		(ctx->start_move_dir == FAT_DIR_FORWARD)?
+			"forwards" : "backwards");
+#endif
+
+	return 1;
+}
+
+FatOpContext*
+fat_op_context_new (PedFileSystem* new_fs, PedFileSystem* old_fs)
+{
+	FatSpecific*	old_fs_info = FAT_SPECIFIC (old_fs);
+	FatSpecific*	new_fs_info = FAT_SPECIFIC (new_fs);
+	FatOpContext*	ctx;
+
+	ctx = (FatOpContext*) ped_malloc (sizeof (FatOpContext));
+	if (!ctx)
+		goto error;
+
+	ctx->frag_sectors = PED_MIN (old_fs_info->cluster_sectors,
+				     new_fs_info->cluster_sectors);
+	if (!fat_set_frag_sectors (new_fs, ctx->frag_sectors))
+		goto error;
+	if (!fat_set_frag_sectors (old_fs, ctx->frag_sectors))
+		goto error;
+
+	ctx->buffer_frags = old_fs_info->buffer_sectors / ctx->frag_sectors;
+	ctx->buffer_map = (FatFragment*) ped_malloc (sizeof (FatFragment)
+						     * ctx->buffer_frags);
+	if (!ctx->buffer_map)
+		goto error_free_ctx;
+
+	ctx->remap = (FatFragment*) ped_malloc (sizeof (FatFragment)
+						   * old_fs_info->frag_count);
+	if (!ctx->remap)
+		goto error_free_buffer_map;
+
+	ctx->new_fs = new_fs;
+	ctx->old_fs = old_fs;
+	if (!calc_deltas (ctx))
+		goto error_free_buffer_map;
+
+	return ctx;
+
+error_free_buffer_map:
+	free (ctx->buffer_map);
+error_free_ctx:
+	free (ctx);
+error:
+	return NULL;
+}
+
+void
+fat_op_context_destroy (FatOpContext* ctx)
+{
+	free (ctx->buffer_map);
+	free (ctx->remap);
+	free (ctx);
+}
+
+FatFragment _GL_ATTRIBUTE_PURE
+fat_op_context_map_static_fragment (const FatOpContext* ctx, FatFragment frag)
+{
+	FatSpecific*	new_fs_info = FAT_SPECIFIC (ctx->new_fs);
+	FatFragment	result;
+
+	if (ctx->new_fs->geom->dev != ctx->old_fs->geom->dev)
+		return -1;
+
+	if (ctx->start_move_dir == FAT_DIR_FORWARD) {
+		if (frag < ctx->start_move_delta)
+			return -1;
+		result = frag - ctx->start_move_delta;
+	} else {
+		result = frag + ctx->start_move_delta;
+	}
+
+	if (result >= new_fs_info->frag_count)
+		return -1;
+
+	return result;
+}
+
+FatCluster
+fat_op_context_map_static_cluster (const FatOpContext* ctx, FatCluster clst)
+{
+	FatFragment	mapped_frag;
+
+	mapped_frag = fat_op_context_map_static_fragment (ctx,
+				fat_cluster_to_frag (ctx->old_fs, clst));
+	if (mapped_frag != -1)
+		return fat_frag_to_cluster (ctx->new_fs, mapped_frag);
+	else
+		return 0;
+}
+
+FatFragment _GL_ATTRIBUTE_PURE
+fat_op_context_map_fragment (const FatOpContext* ctx, FatFragment frag)
+{
+	return ctx->remap [frag];
+}
+
+FatCluster
+fat_op_context_map_cluster (const FatOpContext* ctx, FatCluster clst)
+{
+	FatFragment	mapped_frag;
+
+	mapped_frag = fat_op_context_map_fragment (ctx,
+				fat_cluster_to_frag (ctx->old_fs, clst));
+	if (mapped_frag != -1)
+		return fat_frag_to_cluster (ctx->new_fs, mapped_frag);
+	else
+		return 0;
+}
+
+/* This function sets the initial fat for the new resized file system.
+   This is in *NO WAY* a proper FAT table - all it does is:
+	a) mark bad clusters as bad.
+	b) mark used clusters (that is, clusters from the original FS that are
+	   reachable from the resized one).  Marks as EOF (i.e. used, end of
+	   file chain).
+	c) mark original file system metadata as EOF (i.e. used), to prevent
+	   it from being clobbered.  This will leave the original file system
+	   intact, until the partition table is modified, if the start of
+	   the partition is moved.
+
+   The FATs are rebuilt *properly* after cluster relocation.  This here is
+   only to mark clusters as used, so when cluster relocation occurs, clusters
+   aren't relocated on top of ones marked in a, b or c.
+*/
+int
+fat_op_context_create_initial_fat (FatOpContext* ctx)
+{
+	FatSpecific*	old_fs_info = FAT_SPECIFIC (ctx->old_fs);
+	FatSpecific*	new_fs_info = FAT_SPECIFIC (ctx->new_fs);
+	FatCluster	clst;
+	FatCluster	new_clst;
+	PedSector	sect;
+	PedSector	new_sect;
+	FatFragment	frag;
+	FatFragment	new_frag;
+	FatClusterFlag	frag_flag;
+
+	new_fs_info->fat = fat_table_new (
+		new_fs_info->fat_type,
+		new_fs_info->fat_sectors * 512
+			/ fat_table_entry_size (new_fs_info->fat_type));
+	if (!new_fs_info->fat)
+		return 0;
+
+	if (!fat_table_set_cluster_count (new_fs_info->fat,
+					  new_fs_info->cluster_count))
+		return 0;
+
+/* mark bad and used clusters */
+	for (frag = 0; frag < old_fs_info->frag_count; frag++) {
+		frag_flag = fat_get_fragment_flag (ctx->old_fs, frag);
+		if (frag_flag == FAT_FLAG_FREE)
+			continue;
+
+		new_frag = fat_op_context_map_static_fragment (ctx, frag);
+		if (new_frag == -1)
+			continue;
+
+		new_clst = fat_frag_to_cluster (ctx->new_fs, new_frag);
+		PED_ASSERT (new_clst != 0);
+
+		if (frag_flag == FAT_FLAG_BAD) {
+			if (!fat_table_set_bad (new_fs_info->fat, new_clst))
+				return 0;
+		} else {
+			if (!fat_table_set_eof (new_fs_info->fat, new_clst))
+				return 0;
+		}
+	}
+
+/* mark metadata regions that map to clusters on the new FS */
+	for (sect = 0; sect < old_fs_info->cluster_offset; sect++) {
+		new_sect = ped_geometry_map (ctx->new_fs->geom,
+					     ctx->old_fs->geom, sect);
+		if (new_sect == -1
+		    || !fat_is_sector_in_clusters (ctx->new_fs, new_sect))
+			continue;
+
+		clst = fat_sector_to_cluster (ctx->new_fs, new_sect);
+		PED_ASSERT (clst != 0);
+
+		if (!fat_table_set_eof (new_fs_info->fat, clst))
+			return 0;
+	}
+
+	return 1;
+}
+
+#endif /* !DISCOVER_ONLY */
diff --git a/libparted/fs/r/fat/context.h b/libparted/fs/r/fat/context.h
new file mode 100644
index 0000000..9a76a47
--- /dev/null
+++ b/libparted/fs/r/fat/context.h
@@ -0,0 +1,70 @@
+/*
+    libparted
+    Copyright (C) 1999-2000, 2007, 2009-2014, 2019-2023 Free Software
+    Foundation, Inc.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef PED_FAT_CONTEXT_H_INCLUDED
+#define PED_FAT_CONTEXT_H_INCLUDED
+
+#include "count.h"
+
+enum _FatDirection {
+	FAT_DIR_FORWARD,
+	FAT_DIR_BACKWARD
+};
+typedef enum _FatDirection FatDirection;
+
+struct _FatOpContext {
+	PedFileSystem*		old_fs;
+	PedFileSystem*		new_fs;
+
+	PedSector		frag_sectors;	/* should equal old_fs and
+						   new_fs's frag_sectors */
+
+	FatDirection		start_move_dir;
+	FatFragment		start_move_delta;
+
+	FatFragment		buffer_offset;
+	FatFragment		buffer_frags;
+	FatFragment*		buffer_map;
+
+	FatFragment		frags_duped;
+
+	FatFragment*		remap;
+
+	FatCluster		new_root_dir [32];
+};
+typedef struct _FatOpContext FatOpContext;
+
+extern FatOpContext* fat_op_context_new (PedFileSystem* new_fs,
+					 PedFileSystem* old_fs);
+
+extern void fat_op_context_destroy (FatOpContext* ctx);
+
+extern FatFragment fat_op_context_map_static_fragment (const FatOpContext* ctx,
+						       FatFragment frag);
+extern FatCluster fat_op_context_map_static_cluster (const FatOpContext* ctx,
+						     FatCluster clst);
+
+extern FatFragment fat_op_context_map_fragment (const FatOpContext* ctx,
+					        FatFragment frag);
+extern FatCluster fat_op_context_map_cluster (const FatOpContext* ctx,
+					      FatCluster clst);
+
+extern int fat_op_context_create_initial_fat (FatOpContext* ctx);
+
+#endif /* PED_FAT_CONTEXT_H_INCLUDED */
diff --git a/libparted/fs/r/fat/count.c b/libparted/fs/r/fat/count.c
new file mode 100644
index 0000000..e23404b
--- /dev/null
+++ b/libparted/fs/r/fat/count.c
@@ -0,0 +1,319 @@
+/*
+    libparted
+    Copyright (C) 1998-2000, 2007, 2009-2014, 2019-2023 Free Software
+    Foundation, Inc.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+#include "fat.h"
+#include "traverse.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifndef DISCOVER_ONLY
+
+/*
+    prints out the sequence of clusters for a given file chain, beginning
+    at start_cluster.
+*/
+#ifdef PED_VERBOSE
+static void
+print_chain (PedFileSystem* fs, FatCluster start)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+	FatCluster	clst;
+	int		this_row;
+
+	this_row = 0;
+	for (clst = start; !fat_table_is_eof (fs_info->fat, clst);
+	     clst = fat_table_get (fs_info->fat, clst)) {
+		printf ("  %d", (int) clst);
+		if (++this_row == 7) {
+                        putchar ('\n');
+			this_row = 0;
+		}
+	}
+	putchar ('\n');
+}
+#endif /* PED_VERBOSE */
+
+static PedSector
+remainder_round_up (PedSector a, PedSector b)
+{
+	PedSector	result;
+
+	result = a % b;
+	if (!result)
+		result = b;
+	return result;
+}
+
+/*
+    traverse the FAT for a file/directory, marking each entry's flag
+    to "flag".
+*/
+static int
+flag_traverse_fat (PedFileSystem* fs, const char* chain_name, FatCluster start,
+		   FatClusterFlag flag, PedSector size)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+	FatCluster	clst;
+	FatCluster	prev_clst;
+	int		last_cluster_usage;
+	FatCluster	chain_length = 0;
+
+	if (fat_table_is_eof (fs_info->fat, start)) {
+		if (ped_exception_throw (
+			PED_EXCEPTION_ERROR,
+			PED_EXCEPTION_IGNORE_CANCEL,
+			_("Bad directory entry for %s: first cluster is the "
+			  "end of file marker."),
+			chain_name)
+				!= PED_EXCEPTION_IGNORE)
+			return 0;
+	}
+
+	for (prev_clst = clst = start; !fat_table_is_eof (fs_info->fat, clst);
+	     prev_clst = clst, clst = fat_table_get (fs_info->fat, clst)) {
+		chain_length++;
+		if (!clst) {
+			ped_exception_throw (PED_EXCEPTION_FATAL,
+				PED_EXCEPTION_CANCEL,
+				_("Bad FAT: unterminated chain for %s.  You "
+				  "should run dosfsck or scandisk."),
+				chain_name);
+			return 0;
+		}
+
+		if (clst >= fs_info->fat->cluster_count + 2) {
+			ped_exception_throw (PED_EXCEPTION_FATAL,
+				PED_EXCEPTION_CANCEL,
+				_("Bad FAT: cluster %d outside file system "
+				  "in chain for %s.  You should run dosfsck "
+				  "or scandisk."),
+				(int) clst, chain_name);
+			return 0;
+		}
+
+		if (fs_info->cluster_info [clst].flag != FAT_FLAG_FREE ) {
+			ped_exception_throw (PED_EXCEPTION_FATAL,
+				PED_EXCEPTION_CANCEL,
+				_("Bad FAT: cluster %d is cross-linked for "
+				  "%s.  You should run dosfsck or scandisk."),
+				(int) clst, chain_name);
+			return 0;
+		}
+
+		if (flag == FAT_FLAG_DIRECTORY)
+			fs_info->total_dir_clusters++;
+
+		fs_info->cluster_info [clst].flag = flag;
+		fs_info->cluster_info [clst].units_used = 0;	/* 0 == 64 */
+	}
+
+	if (size
+	    && chain_length
+	    		!= ped_div_round_up (size, fs_info->cluster_sectors)) {
+		if (ped_exception_throw (
+			PED_EXCEPTION_ERROR,
+			PED_EXCEPTION_IGNORE_CANCEL,
+			_("%s is %dk, but it has %d clusters (%dk)."),
+			chain_name,
+			(int) size / 2,
+			(int) chain_length,
+			(int) chain_length * fs_info->cluster_sectors / 2)
+				!= PED_EXCEPTION_IGNORE)
+			return 0;
+	}
+
+	last_cluster_usage
+		= ped_div_round_up (64 * remainder_round_up (size,
+						fs_info->cluster_sectors),
+				fs_info->cluster_sectors);
+
+	fs_info->cluster_info [prev_clst].units_used = last_cluster_usage;
+
+	return 1;
+}
+
+/*
+    recursively traverses a directory, flagging all clusters in the process.
+    It frees the traverse_info structure before returning.
+*/
+static int
+flag_traverse_dir (FatTraverseInfo* trav_info) {
+	PedFileSystem*		fs = trav_info->fs;
+	FatDirEntry*		this_entry;
+	FatTraverseInfo*	subdir_trav_info;
+	char			file_name [4096];
+	char*			file_name_start;
+	FatCluster		first_cluster;
+	PedSector		size;
+
+	PED_ASSERT (trav_info != NULL);
+
+	strcpy (file_name, trav_info->dir_name);
+	file_name_start = file_name + strlen (file_name);
+
+	while ( (this_entry = fat_traverse_next_dir_entry (trav_info)) ) {
+		if (fat_dir_entry_is_null_term (this_entry))
+			break;
+		if (!fat_dir_entry_has_first_cluster (this_entry, fs))
+			continue;
+		if (this_entry->name [0] == '.')
+			continue;	/* skip . and .. entries */
+
+		fat_dir_entry_get_name (this_entry, file_name_start);
+		first_cluster = fat_dir_entry_get_first_cluster(this_entry, fs);
+		size = ped_div_round_up (fat_dir_entry_get_length (this_entry),
+					 512);
+
+#ifdef PED_VERBOSE
+		printf ("%s: ", file_name);
+		print_chain (fs, first_cluster);
+#endif
+
+		if (fat_dir_entry_is_directory (this_entry)) {
+			if (!flag_traverse_fat (fs, file_name, first_cluster,
+						FAT_FLAG_DIRECTORY, size))
+				return 0;
+
+			subdir_trav_info = fat_traverse_directory (trav_info,
+								   this_entry);
+			if (!subdir_trav_info)
+				return 0;
+			if (!flag_traverse_dir (subdir_trav_info))
+				return 0;
+		} else if (fat_dir_entry_is_file (this_entry)) {
+			if (!flag_traverse_fat (fs, file_name, first_cluster,
+						FAT_FLAG_FILE, size))
+				return 0;
+		}
+	}
+
+	fat_traverse_complete (trav_info);
+	return 1;
+}
+
+static void
+_mark_bad_clusters (PedFileSystem* fs)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+	FatCluster	cluster;
+
+	for (cluster = 2; cluster < fs_info->cluster_count + 2; cluster++) {
+		if (fat_table_is_bad (fs_info->fat, cluster))
+			fs_info->cluster_info [cluster].flag = FAT_FLAG_BAD;
+	}
+}
+
+/*
+    fills in cluster_info.  Each FAT entry (= cluster) is flagged as either
+    FAT_FLAG_FREE, FAT_FLAG_FILE or FAT_FLAG_DIRECTORY.
+
+    Also, the fraction of each cluster (x/64) is recorded
+*/
+int
+fat_collect_cluster_info (PedFileSystem* fs) {
+	FatSpecific*		fs_info = FAT_SPECIFIC (fs);
+	FatTraverseInfo*	trav_info;
+
+	/* set all clusters to unused as a default */
+	memset (fs_info->cluster_info, 0, fs_info->fat->cluster_count + 2);
+	fs_info->total_dir_clusters = 0;
+
+	if (fs_info->fat_type == FAT_TYPE_FAT32) {
+		trav_info = fat_traverse_begin (fs, fs_info->root_cluster,
+						"\\");
+		if (!flag_traverse_dir (trav_info))
+			return 0;
+		if (!flag_traverse_fat (fs, "\\", fs_info->root_cluster,
+                                        FAT_FLAG_DIRECTORY, 0))
+			return 0;
+	} else {
+		trav_info = fat_traverse_begin (fs, FAT_ROOT, "\\");
+		if (!flag_traverse_dir (trav_info))
+			return 0;
+	}
+
+	_mark_bad_clusters (fs);
+	return 1;
+}
+
+FatClusterFlag _GL_ATTRIBUTE_PURE
+fat_get_cluster_flag (PedFileSystem* fs, FatCluster cluster)
+{
+	FatSpecific*		fs_info = FAT_SPECIFIC (fs);
+
+	return fs_info->cluster_info [cluster].flag;
+}
+
+PedSector _GL_ATTRIBUTE_PURE
+fat_get_cluster_usage (PedFileSystem* fs, FatCluster cluster)
+{
+	FatSpecific*		fs_info = FAT_SPECIFIC (fs);
+	int			fraction;
+
+	if (fs_info->cluster_info [cluster].flag == FAT_FLAG_FREE)
+		return 0;
+
+	fraction = fs_info->cluster_info [cluster].units_used;
+	if (fraction == 0)
+		fraction = 64;
+
+	return fraction * fs_info->cluster_sectors / 64;
+}
+
+FatClusterFlag
+fat_get_fragment_flag (PedFileSystem* fs, FatFragment frag)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+	FatCluster	cluster = fat_frag_to_cluster (fs, frag);
+	FatFragment	offset = frag % fs_info->cluster_frags;
+	FatFragment	last_frag_used;
+	FatClusterFlag	flag;
+
+	PED_ASSERT (cluster >= 2 && cluster < fs_info->cluster_count + 2);
+
+	flag = fat_get_cluster_flag (fs, cluster);
+	if (flag != FAT_FLAG_FILE && flag != FAT_FLAG_DIRECTORY)
+		return flag;
+	last_frag_used = (fat_get_cluster_usage (fs, cluster) - 1)
+				/ fs_info->frag_sectors;
+	if (offset > last_frag_used)
+		return FAT_FLAG_FREE;
+	else
+		return flag;
+}
+
+int
+fat_is_fragment_active (PedFileSystem* fs, FatFragment frag)
+{
+	switch (fat_get_fragment_flag (fs, frag)) {
+		case FAT_FLAG_FREE:
+		case FAT_FLAG_BAD:
+			return 0;
+
+		case FAT_FLAG_FILE:
+		case FAT_FLAG_DIRECTORY:
+			return 1;
+	}
+	return 0;
+}
+
+#endif /* !DISCOVER_ONLY */
diff --git a/libparted/fs/r/fat/count.h b/libparted/fs/r/fat/count.h
new file mode 100644
index 0000000..bb7d6af
--- /dev/null
+++ b/libparted/fs/r/fat/count.h
@@ -0,0 +1,46 @@
+/*
+    libparted
+    Copyright (C) 1999-2000, 2007-2014, 2019-2023 Free Software Foundation,
+    Inc.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef COUNT_H_INCLUDED
+#define COUNT_H_INCLUDED
+
+typedef enum _FatClusterFlag FatClusterFlag;
+typedef struct _FatClusterInfo FatClusterInfo;
+
+enum _FatClusterFlag {
+	FAT_FLAG_FREE=0,
+	FAT_FLAG_FILE=1,
+	FAT_FLAG_DIRECTORY=2,
+	FAT_FLAG_BAD=3
+};
+
+struct __attribute__ ((packed)) _FatClusterInfo {
+	unsigned int    units_used:6;   /* 1 unit = cluster_size / 64 */
+	FatClusterFlag  flag:2;
+};
+
+extern int fat_collect_cluster_info (PedFileSystem *fs);
+extern FatClusterFlag fat_get_cluster_flag (PedFileSystem* fs,
+					    FatCluster cluster);
+extern PedSector fat_get_cluster_usage (PedFileSystem* fs, FatCluster cluster);
+extern FatClusterFlag fat_get_fragment_flag (PedFileSystem* fs,
+					     FatFragment frag);
+extern int fat_is_fragment_active (PedFileSystem* fs, FatFragment frag);
+
+#endif /* COUNT_H_INCLUDED */
diff --git a/libparted/fs/r/fat/fat.c b/libparted/fs/r/fat/fat.c
new file mode 100644
index 0000000..6583b5b
--- /dev/null
+++ b/libparted/fs/r/fat/fat.c
@@ -0,0 +1,652 @@
+/*
+    libparted
+    Copyright (C) 1998-2001, 2007-2014, 2019-2023 Free Software Foundation,
+    Inc.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+#include <string.h>
+
+#include "fat.h"
+#include "calc.h"
+#include "../../../labels/misc.h"
+
+PedFileSystem*
+fat_alloc (const PedGeometry* geom)
+{
+	PedFileSystem*		fs;
+
+	fs = (PedFileSystem*) ped_malloc (sizeof (PedFileSystem));
+	if (!fs)
+		goto error;
+
+	fs->type_specific = (FatSpecific*) ped_malloc (sizeof (FatSpecific));
+	if (!fs->type_specific)
+		goto error_free_fs;
+	FatSpecific* fs_info = (FatSpecific*) fs->type_specific;
+	fs_info->boot_sector = NULL;
+	fs_info->info_sector = NULL;
+	fs->geom = ped_geometry_duplicate (geom);
+	if (!fs->geom)
+		goto error_free_type_specific;
+
+	fs->checked = 0;
+	return fs;
+
+error_free_type_specific:
+	free (fs->type_specific);
+error_free_fs:
+	free (fs);
+error:
+	return NULL;
+}
+
+/* Requires the boot sector to be analysed */
+int
+fat_alloc_buffers (PedFileSystem* fs)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+
+	fs_info->buffer_sectors = BUFFER_SIZE;
+        fs_info->buffer = ped_malloc (fs_info->buffer_sectors * 512);
+        if (!fs_info->buffer)
+		goto error;
+
+	fs_info->cluster_info = ped_malloc (fs_info->cluster_count + 2);
+	if (!fs_info->cluster_info)
+		goto error_free_buffer;
+
+	return 1;
+
+error_free_buffer:
+	free (fs_info->buffer);
+error:
+	return 0;
+};
+
+void
+fat_free_buffers (PedFileSystem* fs)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+
+	free (fs_info->cluster_info);
+	free (fs_info->buffer);
+}
+
+void
+fat_free (PedFileSystem* fs)
+{
+	FatSpecific* fs_info = (FatSpecific*) fs->type_specific;
+	free (fs_info->boot_sector);
+	ped_geometry_destroy (fs->geom);
+	free (fs->type_specific);
+	free (fs);
+}
+
+int
+fat_set_frag_sectors (PedFileSystem* fs, PedSector frag_sectors)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+
+	PED_ASSERT (fs_info->cluster_sectors % frag_sectors == 0
+			&& frag_sectors <= fs_info->cluster_sectors);
+
+	fs_info->frag_size = frag_sectors * 512;
+	fs_info->frag_sectors = frag_sectors;
+	fs_info->buffer_frags = fs_info->buffer_sectors / frag_sectors;
+	fs_info->cluster_frags = fs_info->cluster_sectors / frag_sectors;
+	fs_info->frag_count = fs_info->cluster_count * fs_info->cluster_frags;
+
+	return 1;
+}
+
+#ifndef DISCOVER_ONLY
+int
+fat_clobber (PedGeometry* geom)
+{
+	FatBootSector *boot_sector;
+	int ok;
+
+	if (!fat_boot_sector_read (&boot_sector, geom))
+		return 1;
+
+	boot_sector->system_id[0] = 0;
+	boot_sector->boot_sign = 0;
+	if (boot_sector->u.fat16.fat_name[0] == 'F')
+		boot_sector->u.fat16.fat_name[0] = 0;
+	if (boot_sector->u.fat32.fat_name[0] == 'F')
+		boot_sector->u.fat32.fat_name[0] = 0;
+
+        ok = ped_geometry_write (geom, boot_sector, 0, 1);
+	free (boot_sector);
+	return ok;
+}
+
+static int
+_init_fats (PedFileSystem* fs)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+	FatCluster	table_size;
+
+	table_size = fs_info->fat_sectors * 512
+		     / fat_table_entry_size (fs_info->fat_type);
+	fs_info->fat = fat_table_new (fs_info->fat_type, table_size);
+	if (!fs_info->fat)
+		goto error;
+
+	if (!fat_table_read (fs_info->fat, fs, 0))
+		goto error_free_fat;
+
+	return 1;
+
+error_free_fat:
+	fat_table_destroy (fs_info->fat);
+error:
+	return 0;
+}
+
+PedFileSystem*
+fat_open (PedGeometry* geom)
+{
+	PedFileSystem*		fs;
+	FatSpecific*		fs_info;
+
+	fs = fat_alloc (geom);
+	if (!fs)
+		goto error;
+	fs_info = (FatSpecific*) fs->type_specific;
+
+	if (!fat_boot_sector_read (&fs_info->boot_sector, geom))
+		goto error_free_fs;
+	if (!fat_boot_sector_analyse (fs_info->boot_sector, fs))
+		goto error_free_fs;
+	fs->type = (fs_info->fat_type == FAT_TYPE_FAT16)
+				? &fat16_type
+				: &fat32_type;
+	if (fs_info->fat_type == FAT_TYPE_FAT32) {
+		if (!fat_info_sector_read (&fs_info->info_sector, fs))
+			goto error_free_fs;
+	}
+
+	if (!_init_fats (fs))
+		goto error_free_fs;
+	if (!fat_alloc_buffers (fs))
+		goto error_free_fat_table;
+	if (!fat_collect_cluster_info (fs))
+		goto error_free_buffers;
+
+	return fs;
+
+error_free_buffers:
+	fat_free_buffers (fs);
+error_free_fat_table:
+	fat_table_destroy (fs_info->fat);
+error_free_fs:
+	fat_free (fs);
+error:
+	return NULL;
+}
+
+static int
+fat_root_dir_clear (PedFileSystem* fs)
+{
+	FatSpecific*		fs_info = FAT_SPECIFIC (fs);
+	memset (fs_info->buffer, 0, 512 * fs_info->root_dir_sector_count);
+	return ped_geometry_write (fs->geom, fs_info->buffer,
+				   fs_info->root_dir_offset,
+				   fs_info->root_dir_sector_count);
+}
+
+PedFileSystem*
+fat_create (PedGeometry* geom, FatType fat_type, PedTimer* timer)
+{
+	PedFileSystem*		fs;
+	FatSpecific*		fs_info;
+	FatCluster		table_size;
+
+	fs = fat_alloc (geom);
+	if (!fs)
+		goto error;
+	fs_info = (FatSpecific*) fs->type_specific;
+
+	fs_info->logical_sector_size = 1;
+	fs_info->sectors_per_track = geom->dev->bios_geom.sectors;
+	fs_info->heads = geom->dev->bios_geom.heads;
+	fs_info->sector_count = fs->geom->length;
+	fs_info->fat_table_count = 2;
+/* some initial values, to be changed later */
+	fs_info->root_dir_sector_count = FAT_ROOT_DIR_ENTRY_COUNT
+					  / (512 / sizeof (FatDirEntry));
+	fs_info->root_dir_entry_count = FAT_ROOT_DIR_ENTRY_COUNT;
+
+	fs_info->fat_type = fat_type;
+	if (!fat_calc_sizes (fs->geom->length, 0,
+			fs_info->fat_type,
+			fs_info->root_dir_sector_count,
+			&fs_info->cluster_sectors,
+			&fs_info->cluster_count,
+			&fs_info->fat_sectors)) {
+		ped_exception_throw (PED_EXCEPTION_ERROR,
+			PED_EXCEPTION_CANCEL,
+			_("Partition too big/small for a %s file system."),
+			(fat_type == FAT_TYPE_FAT16)
+		       		? fat16_type.name
+				: fat32_type.name);
+		goto error_free_fs;
+	}
+
+	fs_info->cluster_size = fs_info->cluster_sectors * 512;
+
+	fs_info->fat_offset = fat_min_reserved_sector_count (fs_info->fat_type);
+	fs_info->dir_entries_per_cluster
+		= fs_info->cluster_size / sizeof (FatDirEntry);
+
+	if (fs_info->fat_type == FAT_TYPE_FAT16) {
+		/* FAT16 */
+		fs->type = &fat16_type;
+
+		if (fs_info->cluster_count
+			> fat_max_cluster_count (fs_info->fat_type)) {
+			fs_info->cluster_count
+				= fat_max_cluster_count (fs_info->fat_type);
+		}
+
+		fs_info->root_dir_sector_count
+			= FAT_ROOT_DIR_ENTRY_COUNT
+				/ (512 / sizeof (FatDirEntry));
+		fs_info->root_dir_entry_count = FAT_ROOT_DIR_ENTRY_COUNT;
+                fs_info->root_dir_offset
+			= fs_info->fat_offset
+			+ fs_info->fat_sectors * fs_info->fat_table_count;
+		fs_info->cluster_offset
+			= fs_info->root_dir_offset
+			  + fs_info->root_dir_sector_count;
+	} else {
+		/* FAT32 */
+		fs->type = &fat32_type;
+
+		fs_info->info_sector_offset = 1;
+		fs_info->boot_sector_backup_offset = 6;
+
+		fs_info->root_dir_sector_count = 0;
+		fs_info->root_dir_entry_count = 0;
+		fs_info->root_dir_offset = 0;
+
+		fs_info->cluster_offset
+			= fs_info->fat_offset
+			  + fs_info->fat_sectors * fs_info->fat_table_count;
+	}
+
+	table_size = fs_info->fat_sectors * 512
+		     / fat_table_entry_size (fs_info->fat_type);
+	fs_info->fat = fat_table_new (fs_info->fat_type, table_size);
+	if (!fs_info->fat)
+		goto error_free_fs;
+	fat_table_set_cluster_count (fs_info->fat, fs_info->cluster_count);
+	if (!fat_alloc_buffers (fs))
+		goto error_free_fat_table;
+
+	if (fs_info->fat_type == FAT_TYPE_FAT32) {
+		fs_info->root_cluster
+			= fat_table_alloc_cluster (fs_info->fat);
+		fat_table_set_eof (fs_info->fat, fs_info->root_cluster);
+		memset (fs_info->buffer, 0, fs_info->cluster_size);
+		if (!fat_write_cluster (fs, fs_info->buffer,
+					fs_info->root_cluster))
+			goto error_free_buffers;
+	}
+
+	fs_info->serial_number = generate_random_uint32 ();
+
+	if (!fat_boot_sector_set_boot_code (&fs_info->boot_sector, fs))
+		goto error_free_buffers;
+	if (!fat_boot_sector_generate (&fs_info->boot_sector, fs))
+		goto error_free_buffers;
+	if (!fat_boot_sector_write (fs_info->boot_sector, fs))
+		goto error_free_buffers;
+	if (fs_info->fat_type == FAT_TYPE_FAT32) {
+		if (!fat_info_sector_generate (&fs_info->info_sector, fs))
+			goto error_free_buffers;
+		if (!fat_info_sector_write (fs_info->info_sector, fs))
+			goto error_free_buffers;
+	}
+
+	if (!fat_table_write_all (fs_info->fat, fs))
+		goto error_free_buffers;
+
+	if (fs_info->fat_type == FAT_TYPE_FAT16) {
+		if (!fat_root_dir_clear (fs))
+			goto error_free_buffers;
+	}
+
+	return fs;
+
+error_free_buffers:
+	fat_free_buffers (fs);
+error_free_fat_table:
+	fat_table_destroy (fs_info->fat);
+error_free_fs:
+	fat_free (fs);
+error:
+	return NULL;
+}
+
+PedFileSystem*
+fat_create_fat16 (PedGeometry* geom, PedTimer* timer)
+{
+	return fat_create (geom, FAT_TYPE_FAT16, timer);
+}
+
+PedFileSystem*
+fat_create_fat32 (PedGeometry* geom, PedTimer* timer)
+{
+	return fat_create (geom, FAT_TYPE_FAT32, timer);
+}
+
+int
+fat_close (PedFileSystem* fs)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+
+	fat_free_buffers (fs);
+	fat_table_destroy (fs_info->fat);
+	fat_free (fs);
+	return 1;
+}
+
+/* Hack: just resize the file system outside of its boundaries! */
+PedFileSystem*
+fat_copy (const PedFileSystem* fs, PedGeometry* geom, PedTimer* timer)
+{
+	PedFileSystem*		new_fs;
+
+	new_fs = ped_file_system_open (fs->geom);
+	if (!new_fs)
+		goto error;
+	if (!ped_file_system_resize (new_fs, geom, timer))
+		goto error_close_new_fs;
+	return new_fs;
+
+error_close_new_fs:
+	ped_file_system_close (new_fs);
+error:
+	return 0;
+}
+
+static int
+_compare_fats (PedFileSystem* fs)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+	FatTable*	table_copy;
+	FatCluster	table_size;
+	int		i;
+
+	table_size = fs_info->fat_sectors * 512
+		     / fat_table_entry_size (fs_info->fat_type);
+
+	table_copy = fat_table_new (fs_info->fat_type, table_size);
+	if (!table_copy)
+		goto error;
+
+	for (i = 1; i < fs_info->fat_table_count; i++) {
+		if (!fat_table_read (table_copy, fs, i))
+			goto error_free_table_copy;
+		if (!fat_table_compare (fs_info->fat, table_copy)) {
+			if (ped_exception_throw (PED_EXCEPTION_ERROR,
+				PED_EXCEPTION_IGNORE_CANCEL,
+				_("The FATs don't match.  If you don't know "
+				  "what this means, then select cancel, run "
+				  "scandisk on the file system, and then come "
+				  "back."))
+			    != PED_EXCEPTION_IGNORE)
+				goto error_free_table_copy;
+		}
+	}
+
+	fat_table_destroy (table_copy);
+	return 1;
+
+error_free_table_copy:
+	fat_table_destroy (table_copy);
+error:
+	return 0;
+}
+
+int
+fat_check (PedFileSystem* fs, PedTimer* timer)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+	PedSector	cluster_sectors;
+	FatCluster	cluster_count;
+	PedSector	fat_sectors;
+	PedSector	align_sectors;
+	FatCluster	info_free_clusters;
+
+	align_sectors = fs_info->fat_offset
+			- fat_min_reserved_sector_count (fs_info->fat_type);
+
+	if (!fat_calc_sizes (fs->geom->length,
+			     align_sectors,
+			     fs_info->fat_type,
+			     fs_info->root_dir_sector_count,
+			     &cluster_sectors,
+			     &cluster_count,
+			     &fat_sectors)) {
+		if (ped_exception_throw (PED_EXCEPTION_BUG,
+			PED_EXCEPTION_IGNORE_CANCEL,
+			_("There are no possible configurations for this FAT "
+			  "type."))
+				!= PED_EXCEPTION_IGNORE)
+			goto error;
+	}
+
+	if (fs_info->fat_type == FAT_TYPE_FAT16) {
+		if (cluster_sectors != fs_info->cluster_sectors
+		    || cluster_count != fs_info->cluster_count
+		    || fat_sectors != fs_info->fat_sectors) {
+			if (ped_exception_throw (PED_EXCEPTION_WARNING,
+				PED_EXCEPTION_IGNORE_CANCEL,
+				_("File system doesn't have expected sizes for "
+				  "Windows to like it.  "
+				  "Cluster size is %dk (%dk expected); "
+				  "number of clusters is %d (%d expected); "
+				  "size of FATs is %d sectors (%d expected)."),
+				(int) fs_info->cluster_sectors / 2,
+					(int) cluster_sectors / 2,
+				(int) fs_info->cluster_count,
+					(int) cluster_count,
+				(int) fs_info->fat_sectors,
+					(int) fat_sectors)
+					!= PED_EXCEPTION_IGNORE)
+				goto error;
+		}
+	}
+
+	if (fs_info->fat_type == FAT_TYPE_FAT32) {
+		info_free_clusters
+			= PED_LE32_TO_CPU (fs_info->info_sector->free_clusters);
+		if (info_free_clusters != (FatCluster) -1
+		    && info_free_clusters != fs_info->fat->free_cluster_count) {
+			if (ped_exception_throw (PED_EXCEPTION_WARNING,
+				PED_EXCEPTION_IGNORE_CANCEL,
+				_("File system is reporting the free space as "
+				  "%d clusters, not %d clusters."),
+				info_free_clusters,
+				fs_info->fat->free_cluster_count)
+					!= PED_EXCEPTION_IGNORE)
+				goto error;
+		}
+	}
+
+	if (!_compare_fats (fs))
+		goto error;
+
+	fs->checked = 1;
+	return 1;	/* existence of fs implies consistency ;-) */
+
+error:
+	return 0;
+}
+
+/* Calculates how much space there will be in clusters in:
+ * 	old_fs intersect the-new-fs
+ */
+static PedSector
+_calc_resize_data_size (
+	const PedFileSystem* old_fs,
+	PedSector new_cluster_sectors,
+	FatCluster new_cluster_count,
+	PedSector new_fat_size)
+{
+	FatSpecific*	old_fs_info = FAT_SPECIFIC (old_fs);
+	PedSector	fat_size_delta;
+
+	fat_size_delta = old_fs_info->fat_sectors - new_fat_size;
+	return new_cluster_sectors * new_cluster_count - fat_size_delta * 2;
+}
+
+static int
+_test_resize_size (const PedFileSystem* fs,
+		   PedSector length, PedSector min_data_size)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+	PedGeometry	geom;
+        PedSector	_cluster_sectors;
+	FatCluster	_cluster_count;
+	PedSector	_fat_size;
+
+	ped_geometry_init (&geom, fs->geom->dev, fs->geom->start, length);
+
+	if (fat_calc_resize_sizes (
+				&geom,
+				fs_info->cluster_sectors,
+				FAT_TYPE_FAT16,
+				fs_info->root_dir_sector_count,
+				fs_info->cluster_sectors,
+				&_cluster_sectors,
+				&_cluster_count,
+				&_fat_size)
+	    && _calc_resize_data_size (fs, _cluster_sectors, _cluster_count,
+		    		       _fat_size)
+	    		>= min_data_size)
+		return 1;
+
+	if (fat_calc_resize_sizes (
+				&geom,
+				fs_info->cluster_sectors,
+				FAT_TYPE_FAT32,
+				0,
+				fs_info->cluster_sectors,
+				&_cluster_sectors,
+				&_cluster_count,
+				&_fat_size)
+	    && _calc_resize_data_size (fs, _cluster_sectors, _cluster_count,
+		    		       _fat_size)
+	    		>= min_data_size)
+		return 1;
+
+	return 0;
+}
+
+/* does a binary search (!) for the mininum size.  Too hard to compute directly
+ * (see calc_sizes() for why!)
+ */
+static PedSector
+_get_min_resize_size (const PedFileSystem* fs, PedSector min_data_size)
+{
+	PedSector	min_length = 0;
+	PedSector	max_length = fs->geom->length;
+	PedSector	length;
+
+	while (min_length < max_length - 1) {
+		length = (min_length + max_length) / 2;
+		if (_test_resize_size (fs, length, min_data_size))
+			max_length = length;
+		else
+			min_length = length;
+	}
+
+/* adds a bit of leeway (64 sectors), for resolving extra issues, like root
+ * directory allocation, that aren't covered here.
+ */
+	return max_length + 64;
+}
+
+PedConstraint*
+fat_get_copy_constraint (const PedFileSystem* fs, const PedDevice* dev)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+	PedGeometry	full_dev;
+	PedSector	min_cluster_count;
+	FatCluster	used_clusters;
+	PedSector	min_data_size;
+
+	if (!ped_geometry_init (&full_dev, dev, 0, dev->length - 1))
+		return NULL;
+
+	used_clusters = fs_info->fat->cluster_count
+			- fs_info->fat->free_cluster_count;
+	min_cluster_count = used_clusters + fs_info->total_dir_clusters;
+	min_data_size = min_cluster_count * fs_info->cluster_sectors;
+
+	return ped_constraint_new (ped_alignment_any, ped_alignment_any,
+				   &full_dev, &full_dev,
+				   _get_min_resize_size (fs, min_data_size),
+				   dev->length);
+}
+
+PedConstraint*
+fat_get_resize_constraint (const PedFileSystem* fs)
+{
+	return fat_get_copy_constraint (fs, fs->geom->dev);
+}
+
+PedConstraint*
+fat_get_create_constraint_fat16 (const PedDevice* dev)
+{
+	PedGeometry	full_dev;
+	PedSector	min_size;
+	PedSector	max_size;
+
+	if (!ped_geometry_init (&full_dev, dev, 0, dev->length - 1))
+		return NULL;
+
+	min_size = 65794;
+	max_size = 2097153;
+
+	return ped_constraint_new (
+			ped_alignment_any, ped_alignment_any,
+			&full_dev, &full_dev,
+			min_size, max_size);
+}
+
+PedConstraint*
+fat_get_create_constraint_fat32 (const PedDevice* dev)
+{
+	PedGeometry	full_dev;
+	PedSector	min_size;
+
+	if (!ped_geometry_init (&full_dev, dev, 0, dev->length - 1))
+		return NULL;
+
+	min_size = 525224;
+
+	return ped_constraint_new (
+			ped_alignment_any, ped_alignment_any,
+			&full_dev, &full_dev,
+			min_size, dev->length);
+}
+#endif /* !DISCOVER_ONLY */
diff --git a/libparted/fs/r/fat/fat.h b/libparted/fs/r/fat/fat.h
new file mode 100644
index 0000000..54f0669
--- /dev/null
+++ b/libparted/fs/r/fat/fat.h
@@ -0,0 +1,159 @@
+/*
+    libparted
+    Copyright (C) 1998-2001, 2007, 2009-2014, 2019-2023 Free Software
+    Foundation, Inc.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef FAT_H_INCLUDED
+#define FAT_H_INCLUDED
+
+#include <parted/parted.h>
+#include <parted/endian.h>
+#include <parted/debug.h>
+
+#if ENABLE_NLS
+#  include <libintl.h>
+#  define _(String) dgettext (PACKAGE, String)
+#else
+#  define _(String) (String)
+#endif /* ENABLE_NLS */
+
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#define BUFFER_SIZE  1024	/* buffer size in sectors (512 bytes) */
+
+typedef uint32_t		FatCluster;
+typedef int32_t			FatFragment;
+
+enum _FatType {
+	FAT_TYPE_FAT12,
+	FAT_TYPE_FAT16,
+	FAT_TYPE_FAT32
+};
+typedef enum _FatType		FatType;
+
+typedef struct _FatSpecific	FatSpecific;
+typedef struct _FatDirEntry	FatDirEntry;
+
+/* FIXME: YUCKY */
+#include "table.h"
+#include "bootsector.h"
+#include "context.h"
+#include "fatio.h"
+#include "traverse.h"
+#include "calc.h"
+#include "count.h"
+#include "clstdup.h"
+
+struct __attribute__ ((packed)) _FatDirEntry {
+	char		name[8];
+	uint8_t		extension[3];
+	uint8_t		attributes;
+	uint8_t		is_upper_case_name;
+	uint8_t		creation_time_low;      /* milliseconds */
+	uint16_t	creation_time_high;
+	uint16_t	creation_date;
+	uint16_t	access_date;
+	uint16_t	first_cluster_high;     /* for FAT32 */
+	uint16_t	time;
+	uint16_t	date;
+	uint16_t	first_cluster;
+	uint32_t	length;
+};
+
+struct _FatSpecific {
+	FatBootSector	*boot_sector;    /* structure of boot sector */
+	FatInfoSector	*info_sector;    /* fat32-only information sector */
+
+	int		logical_sector_size;	/* illogical sector size :-) */
+	PedSector	sector_count;
+
+	int		sectors_per_track;	/* BIOS CHS stuff (S) */
+	int		heads;			/* BIOS CHS stuff (H) */
+
+	int		cluster_size;
+	PedSector	cluster_sectors;
+	FatCluster	cluster_count;
+	int		dir_entries_per_cluster;
+
+	FatType		fat_type;
+	int		fat_table_count;
+	PedSector	fat_sectors;
+
+	uint32_t	serial_number;
+
+	PedSector	info_sector_offset;     /* FAT32 only */
+	PedSector	fat_offset;
+	PedSector	root_dir_offset;	/* non-FAT32 */
+	PedSector	cluster_offset;
+	PedSector	boot_sector_backup_offset;
+
+	FatCluster	root_cluster;           /* FAT32 only */
+	int		root_dir_entry_count;   /* non-FAT32 */
+	PedSector	root_dir_sector_count;  /* non-FAT32 */
+	FatCluster	total_dir_clusters;
+
+	FatTable*	fat;
+	FatClusterInfo*	cluster_info;
+
+	PedSector	buffer_sectors;
+	char*		buffer;
+
+	int		frag_size;
+	PedSector	frag_sectors;
+	FatFragment	frag_count;
+	FatFragment	buffer_frags;
+	FatFragment	cluster_frags;
+};
+
+#define FAT_SPECIFIC(fs)	((FatSpecific*) fs->type_specific)
+
+#define FAT_ROOT		0
+
+#define DELETED_FLAG		0xe5
+
+#define READONLY_ATTR		0x01
+#define HIDDEN_ATTR		0x02
+#define SYSTEM_ATTR		0x04
+#define VOLUME_LABEL_ATTR	0x08
+#define VFAT_ATTR		0x0f
+#define DIRECTORY_ATTR		0x10
+#define ARCH_ATTR		0x20
+
+#define MAX_FAT12_CLUSTERS	4086
+#define MAX_FAT16_CLUSTERS	65526
+#define MAX_FAT32_CLUSTERS	2000000
+
+#define FAT_ROOT_DIR_ENTRY_COUNT	512
+
+extern PedFileSystemType fat16_type;
+extern PedFileSystemType fat32_type;
+
+extern void fat_print (const PedFileSystem* fs);
+
+extern PedFileSystem* fat_alloc (const PedGeometry* geom);
+extern void fat_free (PedFileSystem* fs);
+extern int fat_alloc_buffers (PedFileSystem* fs);
+extern void fat_free_buffers (PedFileSystem* fs);
+
+extern int fat_resize (PedFileSystem* fs, PedGeometry* geom, PedTimer* timer);
+
+extern int fat_set_frag_sectors (PedFileSystem* fs, PedSector frag_sectors);
+
+#endif /* FAT_H_INCLUDED */
diff --git a/libparted/fs/r/fat/fatio.c b/libparted/fs/r/fat/fatio.c
new file mode 100644
index 0000000..3a947ff
--- /dev/null
+++ b/libparted/fs/r/fat/fatio.c
@@ -0,0 +1,150 @@
+/*
+    libparted
+    Copyright (C) 1998-2000, 2007, 2009-2014, 2019-2023 Free Software
+    Foundation, Inc.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+#include "fat.h"
+#include "fatio.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <ctype.h>
+
+#ifndef DISCOVER_ONLY
+
+int
+fat_read_fragments (PedFileSystem* fs, char* buf, FatFragment frag,
+		    FatFragment count)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+	PedSector	sector = fat_frag_to_sector (fs, frag);
+	PedSector	sector_count = count * fs_info->frag_sectors;
+
+	PED_ASSERT (frag >= 0 && frag < fs_info->frag_count);
+
+	return ped_geometry_read (fs->geom, buf, sector, sector_count);
+}
+
+int
+fat_read_fragment (PedFileSystem* fs, char* buf, FatFragment frag)
+{
+	return fat_read_fragments (fs, buf, frag, 1);
+}
+
+int
+fat_write_fragments (PedFileSystem* fs, char* buf, FatFragment frag,
+		     FatFragment count)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+	PedSector	sector = fat_frag_to_sector (fs, frag);
+	PedSector	sector_count = count * fs_info->frag_sectors;
+
+	PED_ASSERT (frag >= 0 && frag < fs_info->frag_count);
+
+	return ped_geometry_write (fs->geom, buf, sector, sector_count);
+}
+
+int
+fat_write_fragment (PedFileSystem* fs, char* buf, FatFragment frag)
+{
+	return fat_write_fragments (fs, buf, frag, 1);
+}
+
+int
+fat_write_sync_fragments (PedFileSystem* fs, char* buf, FatFragment frag,
+			  FatFragment count)
+{
+	if (!fat_write_fragments (fs, buf, frag, count))
+		return 0;
+	if (!ped_geometry_sync (fs->geom))
+		return 0;
+	return 1;
+}
+
+int
+fat_write_sync_fragment (PedFileSystem* fs, char* buf, FatFragment frag)
+{
+	return fat_write_sync_fragments (fs, buf, frag, 1);
+}
+
+int
+fat_read_clusters (PedFileSystem* fs, char *buf, FatCluster cluster,
+		   FatCluster count)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+	PedSector	sector = fat_cluster_to_sector (fs, cluster);
+	PedSector	sector_count = count * fs_info->cluster_sectors;
+
+	PED_ASSERT (cluster >= 2
+	    	    && cluster + count - 1 < fs_info->cluster_count + 2);
+
+	return ped_geometry_read (fs->geom, buf, sector, sector_count);
+}
+
+int
+fat_read_cluster (PedFileSystem* fs, char *buf, FatCluster cluster)
+{
+	return fat_read_clusters (fs, buf, cluster, 1);
+}
+
+int
+fat_write_clusters (PedFileSystem* fs, char *buf, FatCluster cluster,
+		    FatCluster count)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+	PedSector	sector = fat_cluster_to_sector (fs, cluster);
+	PedSector	sector_count = count * fs_info->cluster_sectors;
+
+	PED_ASSERT (cluster >= 2
+	    	    && cluster + count - 1 < fs_info->cluster_count + 2);
+
+	return ped_geometry_write (fs->geom, buf, sector, sector_count);
+}
+
+int
+fat_write_cluster (PedFileSystem* fs, char *buf, FatCluster cluster)
+{
+	return fat_write_clusters (fs, buf, cluster, 1);
+}
+
+int
+fat_write_sync_clusters (PedFileSystem* fs, char *buf, FatCluster cluster,
+			 FatCluster count)
+{
+	if (!fat_write_clusters (fs, buf, cluster, count))
+		return 0;
+	if (!ped_geometry_sync (fs->geom))
+		return 0;
+	return 1;
+}
+
+int
+fat_write_sync_cluster (PedFileSystem* fs, char *buf, FatCluster cluster)
+{
+	if (!fat_write_cluster (fs, buf, cluster))
+		return 0;
+	if (!ped_geometry_sync (fs->geom))
+		return 0;
+	return 1;
+}
+
+#endif /* !DISCOVER_ONLY */
diff --git a/libparted/fs/r/fat/fatio.h b/libparted/fs/r/fat/fatio.h
new file mode 100644
index 0000000..53ebed7
--- /dev/null
+++ b/libparted/fs/r/fat/fatio.h
@@ -0,0 +1,49 @@
+/*
+    libparted
+    Copyright (C) 1998-2000, 2007, 2009-2014, 2019-2023 Free Software
+    Foundation, Inc.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef FATIO_H_INCLUDED
+#define FATIO_H_INCLUDED
+
+#include "fat.h"
+
+extern int fat_read_fragments (PedFileSystem* fs, char* buf, FatFragment frag,
+			       FatFragment count);
+extern int fat_write_fragments (PedFileSystem* fs, char* buf, FatFragment frag,
+			        FatFragment count);
+extern int fat_write_sync_fragments (PedFileSystem* fs, char* buf,
+				     FatFragment frag, FatFragment count);
+
+extern int fat_read_fragment (PedFileSystem* fs, char* buf, FatFragment frag);
+extern int fat_write_fragment (PedFileSystem* fs, char* buf, FatFragment frag);
+extern int fat_write_sync_fragment (PedFileSystem* fs, char* buf,
+				    FatFragment frag);
+
+extern int fat_read_clusters (PedFileSystem* fs, char* buf, FatCluster cluster,
+			      FatCluster count);
+extern int fat_write_clusters (PedFileSystem* fs, char* buf, FatCluster cluster,
+			       FatCluster count);
+extern int fat_write_sync_clusters (PedFileSystem* fs, char* buf,
+				    FatCluster cluster, FatCluster count);
+
+extern int fat_read_cluster (PedFileSystem* fs, char *buf, FatCluster cluster);
+extern int fat_write_cluster (PedFileSystem* fs, char *buf, FatCluster cluster);
+extern int fat_write_sync_cluster (PedFileSystem* fs, char *buf,
+				   FatCluster cluster);
+
+#endif /* FATIO_H_INCLUDED */
diff --git a/libparted/fs/r/fat/resize.c b/libparted/fs/r/fat/resize.c
new file mode 100644
index 0000000..78dede4
--- /dev/null
+++ b/libparted/fs/r/fat/resize.c
@@ -0,0 +1,876 @@
+/*
+    libparted
+    Copyright (C) 1998-2000, 2007-2014, 2019-2023 Free Software Foundation,
+    Inc.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+#include "fat.h"
+#include "traverse.h"
+#include "count.h"
+#include "fatio.h"
+#include "calc.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <ctype.h>
+#include <stdarg.h>
+#include <string.h>
+
+#ifndef DISCOVER_ONLY
+
+/* Recursively builds (i.e. makes consistent) the duplicated directory tree
+ * (leaving the original directory tree in tact)
+ */
+static int
+fat_construct_directory (FatOpContext* ctx, FatTraverseInfo* trav_info)
+{
+	FatTraverseInfo*	sub_dir_info;
+	FatDirEntry*		dir_entry;
+	FatCluster		old_first_cluster;
+
+	while ( (dir_entry = fat_traverse_next_dir_entry (trav_info)) ) {
+		if (fat_dir_entry_is_null_term (dir_entry))
+			break;
+		if (!fat_dir_entry_has_first_cluster (dir_entry, ctx->old_fs))
+			continue;
+
+		fat_traverse_mark_dirty (trav_info);
+
+		old_first_cluster = fat_dir_entry_get_first_cluster (dir_entry,
+						ctx->old_fs);
+		fat_dir_entry_set_first_cluster (dir_entry, ctx->new_fs,
+			fat_op_context_map_cluster (ctx, old_first_cluster));
+
+		if (fat_dir_entry_is_directory (dir_entry)
+				&& dir_entry->name [0] != '.') {
+			sub_dir_info
+				= fat_traverse_directory (trav_info, dir_entry);
+			if (!sub_dir_info)
+				return 0;
+			if (!fat_construct_directory (ctx, sub_dir_info))
+				return 0;
+		}
+	}
+	/* remove "stale" entries at the end */
+	while ((dir_entry = fat_traverse_next_dir_entry (trav_info))) {
+		memset (dir_entry, 0, sizeof (FatDirEntry));
+		fat_traverse_mark_dirty (trav_info);
+	}
+	fat_traverse_complete (trav_info);
+	return 1;
+}
+
+static int
+duplicate_legacy_root_dir (FatOpContext* ctx)
+{
+	FatSpecific*		old_fs_info = FAT_SPECIFIC (ctx->old_fs);
+	FatSpecific*		new_fs_info = FAT_SPECIFIC (ctx->new_fs);
+
+	PED_ASSERT (old_fs_info->root_dir_sector_count
+			== new_fs_info->root_dir_sector_count);
+
+	if (!ped_geometry_read (ctx->old_fs->geom, old_fs_info->buffer,
+				old_fs_info->root_dir_offset,
+				old_fs_info->root_dir_sector_count))
+		return 0;
+
+	if (!ped_geometry_write (ctx->new_fs->geom, old_fs_info->buffer,
+				 new_fs_info->root_dir_offset,
+				 new_fs_info->root_dir_sector_count))
+		return 0;
+
+	return 1;
+}
+
+/*
+    Constructs the new directory tree for legacy (FAT16) file systems.
+*/
+static int
+fat_construct_legacy_root (FatOpContext* ctx)
+{
+	FatTraverseInfo*	trav_info;
+
+	if (!duplicate_legacy_root_dir (ctx))
+		return 0;
+	trav_info = fat_traverse_begin (ctx->new_fs, FAT_ROOT, "\\");
+	return fat_construct_directory (ctx, trav_info);
+}
+
+/*
+    Constructs the new directory tree for new (FAT32) file systems.
+*/
+static int
+fat_construct_root (FatOpContext* ctx)
+{
+	FatSpecific*		new_fs_info = FAT_SPECIFIC (ctx->new_fs);
+	FatTraverseInfo*	trav_info;
+
+	trav_info = fat_traverse_begin (ctx->new_fs, new_fs_info->root_cluster,
+					"\\");
+	fat_construct_directory (ctx, trav_info);
+	return 1;
+}
+
+/* Converts the root directory between FAT16 and FAT32.  NOTE: this code
+ * can also do no conversion.  I'm leaving fat_construct_directory(), because
+ * it's really pretty :-)  It also leaves a higher chance of deleted file
+ * recovery, because it doesn't remove redundant entries.  (We do this here,
+ * because brain-damaged FAT16 has an arbitary limit on root directory entries,
+ * so we save room)
+ */
+static int
+fat_convert_directory (FatOpContext* ctx, FatTraverseInfo* old_trav,
+		       FatTraverseInfo* new_trav)
+{
+	FatTraverseInfo*	sub_old_dir_trav;
+	FatTraverseInfo*	sub_new_dir_trav;
+	FatDirEntry*		new_dir_entry;
+	FatDirEntry*		old_dir_entry;
+	FatCluster		old_first_cluster;
+
+	while ( (old_dir_entry = fat_traverse_next_dir_entry (old_trav)) ) {
+		if (fat_dir_entry_is_null_term (old_dir_entry))
+			break;
+		if (!fat_dir_entry_is_active (old_dir_entry))
+			continue;
+
+		new_dir_entry = fat_traverse_next_dir_entry (new_trav);
+		if (!new_dir_entry) {
+			return ped_exception_throw (PED_EXCEPTION_ERROR,
+				PED_EXCEPTION_IGNORE_CANCEL,
+				_("There's not enough room in the root "
+				  "directory for all of the files.  Either "
+				  "cancel, or ignore to lose the files."))
+					== PED_EXCEPTION_IGNORE;
+		}
+
+		*new_dir_entry = *old_dir_entry;
+		fat_traverse_mark_dirty (new_trav);
+
+		if (!fat_dir_entry_has_first_cluster (old_dir_entry,
+						      ctx->old_fs))
+			continue;
+
+		old_first_cluster = fat_dir_entry_get_first_cluster (
+						old_dir_entry, ctx->old_fs);
+		fat_dir_entry_set_first_cluster (new_dir_entry, ctx->new_fs,
+			fat_op_context_map_cluster (ctx, old_first_cluster));
+
+		if (fat_dir_entry_is_directory (old_dir_entry)
+				&& old_dir_entry->name [0] != '.') {
+			sub_old_dir_trav
+			    = fat_traverse_directory (old_trav, old_dir_entry);
+			if (!sub_old_dir_trav) return 0;
+			sub_new_dir_trav
+			    = fat_traverse_directory (new_trav, new_dir_entry);
+			if (!sub_new_dir_trav) {
+				fat_traverse_complete (sub_old_dir_trav);
+				return 0;
+			}
+
+			if (!fat_convert_directory (ctx, sub_old_dir_trav,
+						    sub_new_dir_trav))
+				return 0;
+		}
+	}
+
+	/* remove "stale" entries at the end, just in case there is some
+	 * overlap
+	 */
+	while ((new_dir_entry = fat_traverse_next_dir_entry (new_trav))) {
+		memset (new_dir_entry, 0, sizeof (FatDirEntry));
+		fat_traverse_mark_dirty (new_trav);
+	}
+
+	fat_traverse_complete (old_trav);
+	fat_traverse_complete (new_trav);
+	return 1;
+}
+
+static void
+clear_cluster (PedFileSystem* fs, FatCluster cluster)
+{
+	FatSpecific*		fs_info = FAT_SPECIFIC (fs);
+
+	memset (fs_info->buffer, 0, fs_info->cluster_size);
+	fat_write_cluster (fs, fs_info->buffer, cluster);
+}
+
+/* This MUST be called BEFORE the fat_construct_new_fat(), because cluster
+ * allocation depend on the old FAT.  The reason is, old clusters may
+ * still be needed during the resize, (particularly clusters in the directory
+ * tree) even if they will be discarded later.
+ */
+static int
+alloc_root_dir (FatOpContext* ctx)
+{
+	FatSpecific*		old_fs_info = FAT_SPECIFIC (ctx->old_fs);
+	FatSpecific*		new_fs_info = FAT_SPECIFIC (ctx->new_fs);
+	FatCluster		i;
+	FatCluster		cluster;
+	FatCluster		cluster_count;
+
+	PED_ASSERT (new_fs_info->fat_type == FAT_TYPE_FAT32);
+
+	cluster_count = ped_div_round_up (
+			   PED_MAX (16, old_fs_info->root_dir_sector_count),
+			   new_fs_info->cluster_sectors);
+
+	for (i = 0; i < cluster_count; i++) {
+		cluster = fat_table_alloc_check_cluster (new_fs_info->fat,
+							 ctx->new_fs);
+		if (!cluster)
+			return 0;
+		ctx->new_root_dir [i] = cluster;
+		clear_cluster (ctx->new_fs, cluster);
+	}
+	ctx->new_root_dir [i] = 0;
+	new_fs_info->root_cluster = ctx->new_root_dir [0];
+	return 1;
+}
+
+/* when converting FAT32 -> FAT16
+ * fat_duplicate clusters() duplicated the root directory unnecessarily.
+ * Let's free it.
+ *
+ * This must be called AFTER fat_construct_new_fat().  (otherwise, our
+ * changes just get overwritten)
+ */
+static int
+free_root_dir (FatOpContext* ctx)
+{
+	FatSpecific*		old_fs_info = FAT_SPECIFIC (ctx->old_fs);
+	FatSpecific*		new_fs_info = FAT_SPECIFIC (ctx->new_fs);
+	FatCluster		old_cluster;
+	FatFragment		i;
+
+	PED_ASSERT (old_fs_info->fat_type == FAT_TYPE_FAT32);
+	PED_ASSERT (new_fs_info->fat_type == FAT_TYPE_FAT16);
+
+	for (old_cluster = old_fs_info->root_cluster;
+	     !fat_table_is_eof (old_fs_info->fat, old_cluster);
+	     old_cluster = fat_table_get (old_fs_info->fat, old_cluster)) {
+		FatFragment old_frag;
+		old_frag = fat_cluster_to_frag (ctx->old_fs, old_cluster);
+		for (i = 0; i < new_fs_info->cluster_frags; i++) {
+			FatFragment new_frag;
+			FatCluster new_clst;
+			new_frag = fat_op_context_map_fragment (ctx,
+								old_frag + i);
+			new_clst = fat_frag_to_cluster (ctx->old_fs, new_frag);
+			if (!fat_table_set_avail (new_fs_info->fat, new_clst))
+				return 0;
+		}
+	}
+
+	return 1;
+}
+
+static int
+fat_clear_root_dir (PedFileSystem* fs)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+	int		i;
+
+	PED_ASSERT (fs_info->fat_type == FAT_TYPE_FAT16);
+	PED_ASSERT (fs_info->root_dir_sector_count);
+
+	memset (fs_info->buffer, 0, 512);
+
+	for (i = 0; i < fs_info->root_dir_sector_count; i++) {
+		if (!ped_geometry_write (fs->geom, fs_info->buffer,
+					 fs_info->root_dir_offset + i, 1)) {
+			if (ped_exception_throw (PED_EXCEPTION_ERROR,
+				PED_EXCEPTION_IGNORE_CANCEL,
+				_("Error writing to the root directory."))
+					== PED_EXCEPTION_CANCEL)
+				return 0;
+		}
+	}
+	return 1;
+}
+
+static int
+fat_construct_converted_tree (FatOpContext* ctx)
+{
+	FatSpecific*		old_fs_info = FAT_SPECIFIC (ctx->old_fs);
+	FatSpecific*		new_fs_info = FAT_SPECIFIC (ctx->new_fs);
+	FatTraverseInfo*	old_trav_info;
+	FatTraverseInfo*	new_trav_info;
+
+	if (new_fs_info->fat_type == FAT_TYPE_FAT32) {
+		new_trav_info = fat_traverse_begin (ctx->new_fs,
+					    new_fs_info->root_cluster, "\\");
+		if (!new_trav_info) return 0;
+		old_trav_info = fat_traverse_begin (ctx->old_fs, FAT_ROOT,
+						    "\\");
+	} else {
+		fat_clear_root_dir (ctx->new_fs);
+		new_trav_info = fat_traverse_begin (ctx->new_fs, FAT_ROOT,
+						    "\\");
+		if (!new_trav_info) return 0;
+		old_trav_info = fat_traverse_begin (ctx->old_fs,
+					    old_fs_info->root_cluster, "\\");
+	}
+	if (!old_trav_info) {
+		fat_traverse_complete (new_trav_info);
+		return 0;
+	}
+	if (!fat_convert_directory (ctx, old_trav_info, new_trav_info))
+		return 0;
+	return 1;
+}
+
+/*
+    Constructs the new directory tree to match the new file locations.
+*/
+static int
+fat_construct_dir_tree (FatOpContext* ctx)
+{
+	FatSpecific*		new_fs_info = FAT_SPECIFIC (ctx->new_fs);
+	FatSpecific*		old_fs_info = FAT_SPECIFIC (ctx->old_fs);
+
+	if (new_fs_info->fat_type == old_fs_info->fat_type) {
+		switch (old_fs_info->fat_type) {
+                        case FAT_TYPE_FAT12:
+                        PED_ASSERT (0);
+                        break;
+
+			case FAT_TYPE_FAT16:
+			return fat_construct_legacy_root (ctx);
+
+			case FAT_TYPE_FAT32:
+			return fat_construct_root (ctx);
+		}
+	} else {
+		return fat_construct_converted_tree (ctx);
+	}
+
+	return 0;
+}
+
+static FatFragment
+_get_next_old_frag (FatOpContext* ctx, FatFragment frag)
+{
+	FatSpecific*	old_fs_info = FAT_SPECIFIC (ctx->old_fs);
+	FatCluster	cluster;
+	FatCluster	next_cluster;
+
+	if ((frag + 1) % old_fs_info->cluster_frags != 0) {
+		if (fat_is_fragment_active (ctx->old_fs, frag + 1))
+			return frag + 1;
+		else
+			return -1;
+	} else {
+		cluster = fat_frag_to_cluster (ctx->old_fs, frag);
+		next_cluster = fat_table_get (old_fs_info->fat, cluster);
+
+		if (fat_table_is_eof (old_fs_info->fat, next_cluster))
+			return -1;
+		else
+			return fat_cluster_to_frag (ctx->old_fs, next_cluster);
+	}
+}
+
+/*
+    Constructs the new fat for the resized file system.
+*/
+static int
+fat_construct_new_fat (FatOpContext* ctx)
+{
+	FatSpecific*	old_fs_info = FAT_SPECIFIC (ctx->old_fs);
+	FatSpecific*	new_fs_info = FAT_SPECIFIC (ctx->new_fs);
+	FatFragment	old_frag;
+	FatCluster	new_cluster;
+	FatFragment	new_frag;
+	FatFragment	old_next_frag;
+	FatFragment	new_next_frag;
+	FatCluster	new_next_cluster;
+	FatClusterFlag	flag;
+	int		i;
+
+	fat_table_clear (new_fs_info->fat);
+	if (!fat_table_set_cluster_count (new_fs_info->fat,
+					  new_fs_info->cluster_count))
+		return 0;
+
+	for (old_frag = 0; old_frag < old_fs_info->frag_count; old_frag++) {
+		flag = fat_get_fragment_flag (ctx->old_fs, old_frag);
+		if (flag == FAT_FLAG_FREE)
+			continue;
+		if (flag == FAT_FLAG_BAD) {
+			new_frag = fat_op_context_map_static_fragment (
+						ctx, old_frag);
+			if (new_frag == -1)
+				continue;
+			new_cluster = fat_frag_to_cluster (ctx->new_fs,
+							   new_frag);
+			fat_table_set_bad (new_fs_info->fat, new_cluster);
+			continue;
+		}
+
+		new_frag = fat_op_context_map_fragment (ctx, old_frag);
+		new_cluster = fat_frag_to_cluster (ctx->new_fs, new_frag);
+
+		old_next_frag = _get_next_old_frag (ctx, old_frag);
+		if (old_next_frag == -1) {
+			fat_table_set_eof (new_fs_info->fat, new_cluster);
+			continue;
+		}
+
+		new_next_frag = fat_op_context_map_fragment (ctx,
+							     old_next_frag);
+		PED_ASSERT (new_next_frag != -1);
+
+		new_next_cluster = fat_frag_to_cluster (ctx->new_fs,
+							new_next_frag);
+		PED_ASSERT (new_next_cluster != new_cluster);
+
+		fat_table_set (new_fs_info->fat, new_cluster, new_next_cluster);
+	}
+
+	if (old_fs_info->fat_type == FAT_TYPE_FAT32
+	    && new_fs_info->fat_type == FAT_TYPE_FAT32) {
+		new_fs_info->root_cluster
+			= fat_op_context_map_cluster (ctx,
+					old_fs_info->root_cluster);
+	}
+
+	if (old_fs_info->fat_type == FAT_TYPE_FAT16
+	    && new_fs_info->fat_type == FAT_TYPE_FAT32) {
+		for (i=0; ctx->new_root_dir[i+1]; i++) {
+			fat_table_set (new_fs_info->fat,
+				       ctx->new_root_dir[i],
+				       ctx->new_root_dir[i+1]);
+		}
+		fat_table_set_eof (new_fs_info->fat, ctx->new_root_dir[i]);
+	}
+
+	return 1;
+}
+
+static int
+ask_type (PedFileSystem* fs, int fat16_ok, int fat32_ok, FatType* out_fat_type)
+{
+	FatSpecific*		fs_info = FAT_SPECIFIC (fs);
+	PedExceptionOption	status;
+	const char*		fat16_msg;
+	const char*		fat32_msg;
+
+	if (fs_info->fat_type == FAT_TYPE_FAT16)
+		fat16_msg = _("If you leave your file system as FAT16, "
+			      "then you will have no problems.");
+	else
+		fat16_msg = _("If you convert to FAT16, and MS Windows "
+			      "is installed on this partition, then "
+			      "you must re-install the MS Windows boot "
+			      "loader.  If you want to do this, you "
+			      "should consult the Parted manual (or "
+			      "your distribution's manual).");
+
+	if (fs_info->fat_type == FAT_TYPE_FAT32)
+		fat32_msg = _("If you leave your file system as FAT32, "
+			      "then you will not introduce any new "
+			      "problems.");
+	else
+		fat32_msg = _("If you convert to FAT32, and MS Windows "
+			      "is installed on this partition, then "
+			      "you must re-install the MS Windows boot "
+			      "loader.  If you want to do this, you "
+			      "should consult the Parted manual (or "
+			      "your distribution's manual).  Also, "
+			      "converting to FAT32 will make the file "
+			      "system unreadable by MS DOS, MS Windows "
+			      "95a, and MS Windows NT.");
+
+	if (fat16_ok && fat32_ok) {
+		status = ped_exception_throw (
+			 PED_EXCEPTION_INFORMATION,
+			 PED_EXCEPTION_YES_NO_CANCEL,
+			 _("%s  %s  %s"),
+			 _("Would you like to use FAT32?"),
+			 fat16_msg,
+			 fat32_msg);
+
+		switch (status) {
+		case PED_EXCEPTION_YES:
+			*out_fat_type = FAT_TYPE_FAT32;
+			return 1;
+
+		case PED_EXCEPTION_NO:
+			*out_fat_type = FAT_TYPE_FAT16;
+			return 1;
+
+		case PED_EXCEPTION_UNHANDLED:
+			*out_fat_type = fs_info->fat_type;
+			return 1;
+
+		case PED_EXCEPTION_CANCEL:
+			return 0;
+
+                default:
+                        PED_ASSERT (0);
+                        break;
+		}
+	}
+
+	if (fat16_ok) {
+		if (fs_info->fat_type != FAT_TYPE_FAT16) {
+			status = ped_exception_throw (
+				PED_EXCEPTION_WARNING,
+				PED_EXCEPTION_OK_CANCEL,
+				_("%s  %s"),
+				_("The file system can only be resized to this "
+				  "size by converting to FAT16."),
+				fat16_msg);
+			if (status == PED_EXCEPTION_CANCEL)
+				return 0;
+		}
+		*out_fat_type = FAT_TYPE_FAT16;
+		return 1;
+	}
+
+	if (fat32_ok) {
+		if (fs_info->fat_type != FAT_TYPE_FAT32) {
+			status = ped_exception_throw (
+				PED_EXCEPTION_WARNING,
+				PED_EXCEPTION_OK_CANCEL,
+				_("%s  %s"),
+				_("The file system can only be resized to this "
+				  "size by converting to FAT32."),
+				fat32_msg);
+			if (status == PED_EXCEPTION_CANCEL)
+				return 0;
+		}
+		*out_fat_type = FAT_TYPE_FAT32;
+		return 1;
+	}
+
+	ped_exception_throw (
+		PED_EXCEPTION_NO_FEATURE,
+		PED_EXCEPTION_CANCEL,
+		_("GNU Parted cannot resize this partition to this size.  "
+		  "We're working on it!"));
+
+	return 0;
+}
+
+/*  For resize operations: determine if the file system must be FAT16 or FAT32,
+ *  or either.  If the new file system must be FAT32, then query for
+ *  confirmation.  If either file system can be used, query for which one.
+ */
+static int
+get_fat_type (PedFileSystem* fs, const PedGeometry* new_geom,
+	      FatType* out_fat_type)
+{
+	FatSpecific*		fs_info = FAT_SPECIFIC (fs);
+	PedSector		fat16_cluster_sectors;
+	PedSector		fat32_cluster_sectors;
+	FatCluster		dummy_cluster_count;
+	PedSector		dummy_fat_sectors;
+	int			fat16_ok;
+	int			fat32_ok;
+
+	fat16_ok = fat_calc_resize_sizes (
+				    new_geom,
+				    fs_info->cluster_sectors,
+				    FAT_TYPE_FAT16,
+				    fs_info->root_dir_sector_count,
+				    fs_info->cluster_sectors,
+				    &fat16_cluster_sectors,
+				    &dummy_cluster_count,
+				    &dummy_fat_sectors);
+
+	fat32_ok = fat_calc_resize_sizes (
+				    new_geom,
+				    fs_info->cluster_sectors,
+				    FAT_TYPE_FAT32,
+				    fs_info->root_dir_sector_count,
+				    fs_info->cluster_sectors,
+				    &fat32_cluster_sectors,
+				    &dummy_cluster_count,
+				    &dummy_fat_sectors);
+
+	return ask_type (fs, fat16_ok, fat32_ok, out_fat_type);
+}
+
+/*  Creates the PedFileSystem struct for the new resized file system, and
+    sticks it in a FatOpContext.  At the end of the process, the original
+    (ctx->old_fs) is destroyed, and replaced with the new one (ctx->new_fs).
+ */
+static FatOpContext*
+create_resize_context (PedFileSystem* fs, const PedGeometry* new_geom)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+	FatSpecific*	new_fs_info;
+	PedFileSystem*	new_fs;
+	PedSector	new_cluster_sectors;
+	FatCluster	new_cluster_count;
+	PedSector	new_fat_sectors;
+	FatType		new_fat_type;
+	PedSector	root_dir_sector_count;
+	FatOpContext*	context;
+
+	/* hypothetical number of root dir sectors, if we end up using
+	 * FAT16
+	 */
+	if (fs_info->root_dir_sector_count)
+		root_dir_sector_count = fs_info->root_dir_sector_count;
+	else
+		root_dir_sector_count = FAT_ROOT_DIR_ENTRY_COUNT
+						* sizeof (FatDirEntry) / 512;
+
+	if (!get_fat_type (fs, new_geom, &new_fat_type))
+		return 0;
+
+	fat_calc_resize_sizes (new_geom, fs_info->cluster_sectors, new_fat_type,
+		root_dir_sector_count, fs_info->cluster_sectors,
+		&new_cluster_sectors, &new_cluster_count, &new_fat_sectors);
+
+	if (!fat_check_resize_geometry (fs, new_geom, new_cluster_sectors,
+				        new_cluster_count))
+		goto error;
+
+	new_fs = fat_alloc (new_geom);
+	if (!new_fs)
+		goto error;
+
+	new_fs_info = FAT_SPECIFIC (new_fs);
+	if (!new_fs_info)
+		goto error_free_new_fs;
+
+/* preserve boot code, etc. */
+	new_fs_info->boot_sector = ped_malloc (new_geom->dev->sector_size);
+	memcpy (new_fs_info->boot_sector, fs_info->boot_sector,
+		new_geom->dev->sector_size);
+	new_fs_info->info_sector = NULL;
+	if (fs_info->fat_type == FAT_TYPE_FAT32)
+	{
+		PED_ASSERT (fs_info->info_sector != NULL);
+		new_fs_info->info_sector =
+			ped_malloc (new_geom->dev->sector_size);
+		memcpy (new_fs_info->info_sector, fs_info->info_sector,
+			new_geom->dev->sector_size);
+	}
+
+	new_fs_info->logical_sector_size = fs_info->logical_sector_size;
+	new_fs_info->sector_count = new_geom->length;
+
+	new_fs_info->sectors_per_track = fs_info->sectors_per_track;
+	new_fs_info->heads = fs_info->heads;
+
+	new_fs_info->cluster_size = new_cluster_sectors * 512;
+	new_fs_info->cluster_sectors = new_cluster_sectors;
+	new_fs_info->cluster_count = new_cluster_count;
+	new_fs_info->dir_entries_per_cluster = fs_info->dir_entries_per_cluster;
+
+	new_fs_info->fat_type = new_fat_type;
+	new_fs_info->fat_table_count = 2;
+	new_fs_info->fat_sectors = new_fat_sectors;
+
+	/* what about copying? */
+	new_fs_info->serial_number = fs_info->serial_number;
+
+	if (new_fs_info->fat_type == FAT_TYPE_FAT32) {
+		new_fs_info->info_sector_offset	= 1;
+		new_fs_info->boot_sector_backup_offset = 6;
+
+		new_fs_info->root_dir_offset = 0;
+		new_fs_info->root_dir_entry_count = 0;
+		new_fs_info->root_dir_sector_count = 0;
+
+		/* we add calc_align_sectors to push the cluster_offset
+		   forward, to keep the clusters aligned between the new
+		   and old file systems
+		 */
+		new_fs_info->fat_offset
+			= fat_min_reserved_sector_count (FAT_TYPE_FAT32)
+			  + fat_calc_align_sectors (new_fs, fs);
+
+		new_fs_info->cluster_offset
+			= new_fs_info->fat_offset
+			  + 2 * new_fs_info->fat_sectors;
+	} else {
+		new_fs_info->root_dir_sector_count = root_dir_sector_count;
+		new_fs_info->root_dir_entry_count
+			= root_dir_sector_count * 512 / sizeof (FatDirEntry);
+
+		new_fs_info->fat_offset
+			= fat_min_reserved_sector_count (FAT_TYPE_FAT16)
+			  + fat_calc_align_sectors (new_fs, fs);
+
+		new_fs_info->root_dir_offset = new_fs_info->fat_offset
+					       + 2 * new_fs_info->fat_sectors;
+
+		new_fs_info->cluster_offset = new_fs_info->root_dir_offset
+					  + new_fs_info->root_dir_sector_count;
+	}
+
+	new_fs_info->total_dir_clusters = fs_info->total_dir_clusters;
+
+	context = fat_op_context_new (new_fs, fs);
+	if (!context)
+		goto error_free_new_fs_info;
+
+	if (!fat_op_context_create_initial_fat (context))
+		goto error_free_context;
+
+	if (!fat_alloc_buffers (new_fs))
+		goto error_free_fat;
+
+	return context;
+
+error_free_fat:
+	fat_table_destroy (new_fs_info->fat);
+error_free_context:
+	free (context);
+error_free_new_fs_info:
+	free (new_fs_info);
+error_free_new_fs:
+	free (new_fs);
+error:
+	return NULL;
+}
+
+static int
+resize_context_assimilate (FatOpContext* ctx)
+{
+	FatSpecific*	old_fs_info = FAT_SPECIFIC (ctx->old_fs);
+	FatSpecific*	new_fs_info = FAT_SPECIFIC (ctx->new_fs);
+
+	fat_free_buffers (ctx->old_fs);
+	fat_table_destroy (old_fs_info->fat);
+	free (old_fs_info);
+	ped_geometry_destroy (ctx->old_fs->geom);
+
+	ctx->old_fs->type_specific = ctx->new_fs->type_specific;
+	ctx->old_fs->geom = ctx->new_fs->geom;
+	ctx->old_fs->type = (new_fs_info->fat_type == FAT_TYPE_FAT16)
+				? &fat16_type
+			       	: &fat32_type;
+
+	free (ctx->new_fs);
+
+	fat_op_context_destroy (ctx);
+
+	return 1;
+}
+
+static int
+resize_context_abort (FatOpContext* ctx)
+{
+	FatSpecific*	new_fs_info = FAT_SPECIFIC (ctx->new_fs);
+
+	fat_free_buffers (ctx->new_fs);
+	fat_table_destroy (new_fs_info->fat);
+	free (new_fs_info);
+	ped_geometry_destroy (ctx->new_fs->geom);
+	free (ctx->new_fs);
+
+	fat_op_context_destroy (ctx);
+
+	return 1;
+}
+
+/* copies the "hidden" sectors, between the boot sector and the FAT.  Required,
+ * for the Windows 98 FAT32 boot loader
+ */
+int
+_copy_hidden_sectors (FatOpContext* ctx)
+{
+	FatSpecific*    old_fs_info = FAT_SPECIFIC (ctx->old_fs);
+	FatSpecific*    new_fs_info = FAT_SPECIFIC (ctx->new_fs);
+	PedSector       first = 1;
+	PedSector       last;
+	PedSector       count;
+
+	/* nothing to copy for FAT16 */
+	if (old_fs_info->fat_type == FAT_TYPE_FAT16
+			|| new_fs_info->fat_type == FAT_TYPE_FAT16)
+		return 1;
+
+	last = PED_MIN (old_fs_info->fat_offset, new_fs_info->fat_offset) - 1;
+	count = last - first + 1;
+
+	PED_ASSERT (count < BUFFER_SIZE);
+
+	if (!ped_geometry_read (ctx->old_fs->geom, old_fs_info->buffer,
+				first, count))
+		return 0;
+	if (!ped_geometry_write (ctx->new_fs->geom, old_fs_info->buffer,
+				 first, count))
+		return 0;
+	return 1;
+}
+
+int
+fat_resize (PedFileSystem* fs, PedGeometry* geom, PedTimer* timer)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+	FatSpecific*	new_fs_info;
+	FatOpContext*	ctx;
+	PedFileSystem*	new_fs;
+
+	ctx = create_resize_context (fs, geom);
+	if (!ctx)
+		goto error;
+	new_fs = ctx->new_fs;
+	new_fs_info = FAT_SPECIFIC (new_fs);
+
+	if (!fat_duplicate_clusters (ctx, timer))
+		goto error_abort_ctx;
+	if (fs_info->fat_type == FAT_TYPE_FAT16
+			&& new_fs_info->fat_type == FAT_TYPE_FAT32) {
+		if (!alloc_root_dir (ctx))
+			goto error_abort_ctx;
+	}
+	if (!fat_construct_new_fat (ctx))
+		goto error_abort_ctx;
+	if (fs_info->fat_type == FAT_TYPE_FAT32
+			&& new_fs_info->fat_type == FAT_TYPE_FAT16) {
+		if (!free_root_dir (ctx))
+			goto error_abort_ctx;
+	}
+	if (!fat_construct_dir_tree (ctx))
+		goto error_abort_ctx;
+	if (!fat_table_write_all (new_fs_info->fat, new_fs))
+		goto error_abort_ctx;
+
+	_copy_hidden_sectors (ctx);
+	fat_boot_sector_generate (&new_fs_info->boot_sector, new_fs);
+	fat_boot_sector_write (new_fs_info->boot_sector, new_fs);
+	if (new_fs_info->fat_type == FAT_TYPE_FAT32) {
+		fat_info_sector_generate (&new_fs_info->info_sector, new_fs);
+		fat_info_sector_write (new_fs_info->info_sector, new_fs);
+	}
+
+	if (!resize_context_assimilate (ctx))
+		goto error;
+
+	return 1;
+
+error_abort_ctx:
+	resize_context_abort (ctx);
+error:
+	return 0;
+}
+
+#endif /* !DISCOVER_ONLY */
diff --git a/libparted/fs/r/fat/table.c b/libparted/fs/r/fat/table.c
new file mode 100644
index 0000000..ec0907f
--- /dev/null
+++ b/libparted/fs/r/fat/table.c
@@ -0,0 +1,481 @@
+/*
+    libparted
+    Copyright (C) 1998-2000, 2007-2014, 2019-2023 Free Software Foundation,
+    Inc.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+#include <parted/endian.h>
+#include "fat.h"
+
+#ifndef DISCOVER_ONLY
+
+FatTable*
+fat_table_new (FatType fat_type, FatCluster size)
+{
+	FatTable*	ft;
+	int		entry_size = fat_table_entry_size (fat_type);
+
+	ft = (FatTable*) ped_malloc (sizeof (FatTable));
+	if (!ft) return NULL;
+
+	ft->cluster_count = ft->free_cluster_count = size - 2;
+
+/* ensure there's some free room on the end, to finish off the sector */
+	ft->size = ped_div_round_up (size * entry_size, 512) * 512 / entry_size;
+	ft->fat_type = fat_type;
+	ft->raw_size = ft->size * entry_size;
+
+	ft->table = ped_malloc (ft->raw_size);
+	if (!ft->table) {
+		free (ft);
+		return NULL;
+	}
+
+	fat_table_clear (ft);
+	return ft;
+}
+
+void
+fat_table_destroy (FatTable* ft)
+{
+	free (ft->table);
+	free (ft);
+}
+
+FatTable*
+fat_table_duplicate (const FatTable* ft)
+{
+	FatTable*	dup_ft;
+
+	dup_ft = fat_table_new (ft->fat_type, ft->size);
+	if (!dup_ft) return NULL;
+
+	dup_ft->cluster_count	= ft->cluster_count;
+	dup_ft->free_cluster_count	= ft->free_cluster_count;
+	dup_ft->bad_cluster_count	= ft->bad_cluster_count;
+	dup_ft->last_alloc		= ft->last_alloc;
+
+	memcpy (dup_ft->table, ft->table, ft->raw_size);
+
+	return dup_ft;
+}
+
+void
+fat_table_clear (FatTable* ft)
+{
+	memset (ft->table, 0, ft->raw_size);
+
+	fat_table_set (ft, 0, 0x0ffffff8);
+	fat_table_set (ft, 1, 0x0fffffff);
+
+	ft->free_cluster_count = ft->cluster_count;
+	ft->bad_cluster_count = 0;
+	ft->last_alloc = 1;
+}
+
+int
+fat_table_set_cluster_count (FatTable* ft, FatCluster new_cluster_count)
+{
+	PED_ASSERT (new_cluster_count + 2 <= ft->size);
+
+	ft->cluster_count = new_cluster_count;
+	return fat_table_count_stats (ft);
+}
+
+int
+fat_table_count_stats (FatTable* ft)
+{
+	FatCluster	i;
+
+	PED_ASSERT (ft->cluster_count + 2 <= ft->size);
+
+	ft->free_cluster_count = 0;
+	ft->bad_cluster_count = 0;
+
+	for (i=2; i < ft->cluster_count + 2; i++) {
+		if (fat_table_is_available (ft, i))
+			ft->free_cluster_count++;
+		if (fat_table_is_bad (ft, i))
+			ft->bad_cluster_count++;
+	}
+	return 1;
+}
+
+int
+fat_table_read (FatTable* ft, const PedFileSystem* fs, int table_num)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+
+	PED_ASSERT (ft->raw_size >= fs_info->fat_sectors * 512);
+
+	memset (ft->table, 0, ft->raw_size);
+
+        if (!ped_geometry_read (fs->geom, (void *) ft->table,
+				fs_info->fat_offset
+					+ table_num * fs_info->fat_sectors,
+				fs_info->fat_sectors))
+		return 0;
+
+        if ( *((unsigned char*) ft->table) != fs_info->boot_sector->media) {
+		if (ped_exception_throw (
+			PED_EXCEPTION_ERROR,
+			PED_EXCEPTION_IGNORE_CANCEL,
+			_("FAT %d media %x doesn't match the boot sector's "
+			  "media %x.  You should probably run scandisk."),
+			(int) table_num + 1,
+			(int) *((unsigned char*) ft->table),
+			(int) fs_info->boot_sector->media)
+				!= PED_EXCEPTION_IGNORE)
+			return 0;
+        }
+
+	ft->cluster_count = fs_info->cluster_count;
+
+	fat_table_count_stats (ft);
+
+	return 1;
+}
+
+int
+fat_table_write (const FatTable* ft, PedFileSystem* fs, int table_num)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+
+	PED_ASSERT (ft->raw_size >= fs_info->fat_sectors * 512);
+
+        if (!ped_geometry_write (fs->geom, (void *) ft->table,
+				 fs_info->fat_offset
+					+ table_num * fs_info->fat_sectors,
+				 fs_info->fat_sectors))
+		return 0;
+	if (!ped_geometry_sync (fs->geom))
+		return 0;
+
+	return 1;
+}
+
+int
+fat_table_write_all (const FatTable* ft, PedFileSystem* fs)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+	int		i;
+
+	for (i = 0; i < fs_info->fat_table_count; i++) {
+		if (!fat_table_write (ft, fs, i))
+			return 0;
+	}
+
+	return 1;
+}
+
+int
+fat_table_compare (const FatTable* a, const FatTable* b)
+{
+	FatCluster	i;
+
+	if (a->cluster_count != b->cluster_count)
+		return 0;
+
+	for (i = 0; i < a->cluster_count + 2; i++) {
+		if (fat_table_get (a, i) != fat_table_get (b, i))
+			return 0;
+	}
+
+	return 1;
+}
+
+static int
+_test_code_available (const FatTable* ft, FatCluster code)
+{
+	return code == 0;
+}
+
+static int
+_test_code_bad (const FatTable* ft, FatCluster code)
+{
+	switch (ft->fat_type) {
+                case FAT_TYPE_FAT12:
+                if (code == 0xff7) return 1;
+                break;
+
+		case FAT_TYPE_FAT16:
+		if (code == 0xfff7) return 1;
+		break;
+
+		case FAT_TYPE_FAT32:
+		if (code == 0x0ffffff7) return 1;
+		break;
+	}
+	return 0;
+}
+
+static int
+_test_code_eof (const FatTable* ft, FatCluster code)
+{
+	switch (ft->fat_type) {
+                case FAT_TYPE_FAT12:
+                if (code >= 0xff7) return 1;
+                break;
+
+		case FAT_TYPE_FAT16:
+		if (code >= 0xfff7) return 1;
+		break;
+
+		case FAT_TYPE_FAT32:
+		if (code >= 0x0ffffff7) return 1;
+		break;
+	}
+	return 0;
+}
+
+void
+_update_stats (FatTable* ft, FatCluster cluster, FatCluster value)
+{
+	if (_test_code_available (ft, value)
+	    && !fat_table_is_available (ft, cluster)) {
+		ft->free_cluster_count++;
+		if (fat_table_is_bad (ft, cluster))
+			ft->bad_cluster_count--;
+	}
+
+	if (!_test_code_available (ft, value)
+	    && fat_table_is_available (ft, cluster)) {
+		ft->free_cluster_count--;
+		if (_test_code_bad (ft, cluster))
+			ft->bad_cluster_count--;
+	}
+}
+
+int
+fat_table_set (FatTable* ft, FatCluster cluster, FatCluster value)
+{
+	if (cluster >= ft->cluster_count + 2) {
+		ped_exception_throw (PED_EXCEPTION_BUG,
+				     PED_EXCEPTION_CANCEL,
+				     _("fat_table_set: cluster %ld outside "
+				       "file system"),
+				     (long) cluster);
+		return 0;
+	}
+
+	_update_stats (ft, cluster, value);
+
+	switch (ft->fat_type) {
+                case FAT_TYPE_FAT12:
+                PED_ASSERT (0);
+                break;
+
+		case FAT_TYPE_FAT16:
+		((unsigned short *) ft->table) [cluster]
+			= PED_CPU_TO_LE16 (value);
+		break;
+
+		case FAT_TYPE_FAT32:
+		((unsigned int *) ft->table) [cluster]
+			= PED_CPU_TO_LE32 (value);
+		break;
+	}
+	return 1;
+}
+
+FatCluster
+fat_table_get (const FatTable* ft, FatCluster cluster)
+{
+	if (cluster >= ft->cluster_count + 2) {
+		ped_exception_throw (PED_EXCEPTION_BUG,
+				     PED_EXCEPTION_CANCEL,
+				     _("fat_table_get: cluster %ld outside "
+				       "file system"),
+				     (long) cluster);
+		exit (EXIT_FAILURE);	/* FIXME */
+	}
+
+	switch (ft->fat_type) {
+                case FAT_TYPE_FAT12:
+                PED_ASSERT (0);
+                break;
+
+		case FAT_TYPE_FAT16:
+		return PED_LE16_TO_CPU
+			(((unsigned short *) ft->table) [cluster]);
+
+		case FAT_TYPE_FAT32:
+		return PED_LE32_TO_CPU
+			(((unsigned int *) ft->table) [cluster]);
+	}
+
+	return 0;
+}
+
+FatCluster
+fat_table_alloc_cluster (FatTable* ft)
+{
+	FatCluster	i;
+	FatCluster	cluster;
+
+/* hack: assumes the first two FAT entries are marked as used (which they
+ * always should be)
+ */
+	for (i=1; i < ft->cluster_count + 1; i++) {
+		cluster = (i + ft->last_alloc) % ft->cluster_count;
+		if (fat_table_is_available (ft, cluster)) {
+			ft->last_alloc = cluster;
+			return cluster;
+		}
+	}
+
+	ped_exception_throw (PED_EXCEPTION_ERROR,
+			     PED_EXCEPTION_CANCEL,
+			     _("fat_table_alloc_cluster: no free clusters"));
+	return 0;
+}
+
+FatCluster
+fat_table_alloc_check_cluster (FatTable* ft, PedFileSystem* fs)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+	FatCluster	result;
+
+	while (1) {
+		result = fat_table_alloc_cluster (ft);
+		if (!result)
+			return 0;
+		if (fat_read_cluster (fs, fs_info->buffer, result))
+			return result;
+		fat_table_set_bad (ft, result);
+	}
+}
+
+/*
+    returns true if <cluster> is marked as bad
+*/
+int
+fat_table_is_bad (const FatTable* ft, FatCluster cluster)
+{
+	return _test_code_bad (ft, fat_table_get (ft, cluster));
+}
+
+/*
+    returns true if <cluster> represents an EOF marker
+*/
+int _GL_ATTRIBUTE_PURE
+fat_table_is_eof (const FatTable* ft, FatCluster cluster)
+{
+	return _test_code_eof (ft, cluster);
+}
+
+/*
+    returns true if <cluster> is available.
+*/
+int
+fat_table_is_available (const FatTable* ft, FatCluster cluster)
+{
+	return _test_code_available (ft, fat_table_get (ft, cluster));
+}
+
+/*
+    returns true if <cluster> is empty.  Note that this includes bad clusters.
+*/
+int
+fat_table_is_empty (const FatTable* ft, FatCluster cluster)
+{
+	return fat_table_is_available (ft, cluster)
+		|| fat_table_is_bad (ft, cluster);
+}
+
+/*
+    returns true if <cluster> is being used for something constructive.
+*/
+int
+fat_table_is_active (const FatTable* ft, FatCluster cluster)
+{
+	return !fat_table_is_bad (ft, cluster)
+		&& !fat_table_is_available (ft, cluster);
+}
+
+/*
+    marks <cluster> as the last cluster in the chain
+*/
+int
+fat_table_set_eof (FatTable* ft, FatCluster cluster)
+{
+
+	switch (ft->fat_type) {
+                case FAT_TYPE_FAT12:
+                PED_ASSERT (0);
+                break;
+
+		case FAT_TYPE_FAT16:
+		return fat_table_set (ft, cluster, 0xfff8);
+
+		case FAT_TYPE_FAT32:
+		return fat_table_set (ft, cluster, 0x0fffffff);
+	}
+
+	return 0;
+}
+
+/*
+	Marks a clusters as unusable, due to physical disk damage.
+*/
+int
+fat_table_set_bad (FatTable* ft, FatCluster cluster)
+{
+	if (!fat_table_is_bad (ft, cluster))
+		ft->bad_cluster_count++;
+
+	switch (ft->fat_type) {
+                case FAT_TYPE_FAT12:
+		return fat_table_set (ft, cluster, 0xff7);
+
+		case FAT_TYPE_FAT16:
+		return fat_table_set (ft, cluster, 0xfff7);
+
+		case FAT_TYPE_FAT32:
+		return fat_table_set (ft, cluster, 0x0ffffff7);
+	}
+
+	return 0;
+}
+
+/*
+    marks <cluster> as unused/free/available
+*/
+int
+fat_table_set_avail (FatTable* ft, FatCluster cluster)
+{
+	return fat_table_set (ft, cluster, 0);
+}
+
+#endif /* !DISCOVER_ONLY */
+
+int _GL_ATTRIBUTE_CONST
+fat_table_entry_size (FatType fat_type)
+{
+	switch (fat_type) {
+		case FAT_TYPE_FAT12:
+		return 2;		/* FIXME: how? */
+
+		case FAT_TYPE_FAT16:
+		return 2;
+
+		case FAT_TYPE_FAT32:
+		return 4;
+	}
+
+	return 0;
+}
diff --git a/libparted/fs/r/fat/table.h b/libparted/fs/r/fat/table.h
new file mode 100644
index 0000000..a70241b
--- /dev/null
+++ b/libparted/fs/r/fat/table.h
@@ -0,0 +1,74 @@
+/*
+    libparted
+    Copyright (C) 1998-2000, 2007, 2009-2014, 2019-2023 Free Software
+    Foundation, Inc.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef PED_FAT_TABLE_H_INCLUDED
+#define PED_FAT_TABLE_H_INCLUDED
+
+typedef struct _FatTable	FatTable;
+
+#include "fat.h"
+
+struct _FatTable {
+	void*		table;
+	FatCluster	size;
+	int		raw_size;
+
+	FatType		fat_type;
+	FatCluster	cluster_count;
+	FatCluster	free_cluster_count;
+	FatCluster	bad_cluster_count;
+
+	FatCluster	last_alloc;
+};
+
+extern FatTable* fat_table_new (FatType fat_type, FatCluster size);
+extern FatTable* fat_table_duplicate (const FatTable* ft);
+extern void fat_table_destroy (FatTable* ft);
+extern void fat_table_clear (FatTable* ft);
+extern int fat_table_set_cluster_count (FatTable* ft,
+					FatCluster new_cluster_count);
+
+extern int fat_table_read (FatTable* ft, const PedFileSystem* fs,
+			   int table_num);
+extern int fat_table_write (const FatTable* ft, PedFileSystem* fs,
+			    int table_num);
+extern int fat_table_write_all (const FatTable* ft, PedFileSystem* fs);
+extern int fat_table_compare (const FatTable* a, const FatTable* b);
+extern int fat_table_count_stats (FatTable* ft);
+
+extern FatCluster fat_table_get (const FatTable* ft, FatCluster cluster);
+extern int fat_table_set (FatTable* ft, FatCluster cluster, FatCluster value);
+
+extern FatCluster fat_table_alloc_cluster (FatTable* ft);
+extern FatCluster fat_table_alloc_check_cluster (FatTable* ft,
+						 PedFileSystem* fs);
+
+extern int fat_table_is_bad (const FatTable* ft, FatCluster cluster);
+extern int fat_table_is_eof (const FatTable* ft, FatCluster cluster);
+extern int fat_table_is_empty (const FatTable* ft, FatCluster cluster);
+extern int fat_table_is_available (const FatTable* ft, FatCluster cluster);
+extern int fat_table_is_active (const FatTable* ft, FatCluster cluster);
+
+extern int fat_table_set_eof (FatTable* ft, FatCluster cluster);
+extern int fat_table_set_avail (FatTable* ft, FatCluster cluster);
+extern int fat_table_set_bad (FatTable* ft, FatCluster cluster);
+
+extern int fat_table_entry_size (FatType fat_type);
+
+#endif /* PED_FAT_TABLE_H_INCLUDED */
diff --git a/libparted/fs/r/fat/traverse.c b/libparted/fs/r/fat/traverse.c
new file mode 100644
index 0000000..42eeff9
--- /dev/null
+++ b/libparted/fs/r/fat/traverse.c
@@ -0,0 +1,368 @@
+/*
+    libparted
+    Copyright (C) 1998-2000, 2005, 2007-2014, 2019-2023 Free Software
+    Foundation, Inc.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+#include "fat.h"
+#include "traverse.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifndef DISCOVER_ONLY
+
+#define NO_CLUSTER -1
+
+static char tmp_buffer [4096];
+
+int _GL_ATTRIBUTE_PURE
+fat_traverse_entries_per_buffer (FatTraverseInfo* trav_info)
+{
+	return trav_info->buffer_size / sizeof (FatDirEntry);
+}
+
+/* returns 1 if there are no more directory entries in the directory being
+ * traversed, 0 otherwise.
+ */
+static int
+is_last_buffer (FatTraverseInfo* trav_info) {
+	FatSpecific*	fs_info = FAT_SPECIFIC (trav_info->fs);
+
+	if (trav_info->is_legacy_root_dir)
+		return 1;
+	else
+		return fat_table_is_eof (fs_info->fat, trav_info->next_buffer);
+}
+
+static int
+write_root_dir (FatTraverseInfo* trav_info)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (trav_info->fs);
+
+	if (!ped_geometry_write (trav_info->fs->geom, trav_info->dir_entries,
+				 fs_info->root_dir_offset,
+				 fs_info->root_dir_sector_count))
+		return 0;
+	if (!ped_geometry_sync (trav_info->fs->geom))
+		return 0;
+	trav_info->dirty = 0;
+	return 1;
+}
+
+static int
+write_dir_cluster (FatTraverseInfo* trav_info)
+{
+	if (!fat_write_sync_cluster (trav_info->fs,
+				     (void*) trav_info->dir_entries,
+				     trav_info->this_buffer))
+		return 0;
+	trav_info->dirty = 0;
+	return 1;
+}
+
+static int
+write_dir_buffer (FatTraverseInfo* trav_info)
+{
+	if (trav_info->is_legacy_root_dir)
+		return write_root_dir (trav_info);
+	else
+		return write_dir_cluster (trav_info);
+}
+
+static int
+read_next_dir_buffer (FatTraverseInfo* trav_info)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (trav_info->fs);
+
+	PED_ASSERT (!trav_info->is_legacy_root_dir);
+
+	trav_info->this_buffer = trav_info->next_buffer;
+
+	if (trav_info->this_buffer < 2
+	    || trav_info->this_buffer >= fs_info->cluster_count + 2) {
+		ped_exception_throw (
+			PED_EXCEPTION_ERROR,
+			PED_EXCEPTION_CANCEL,
+			"Cluster %ld in directory %s is outside file system!",
+			(long) trav_info->this_buffer,
+			trav_info->dir_name);
+		return 0;
+	}
+
+	trav_info->next_buffer
+		= fat_table_get (fs_info->fat, trav_info->this_buffer);
+
+	return fat_read_cluster (trav_info->fs, (void *) trav_info->dir_entries,
+				 trav_info->this_buffer);
+}
+
+/* FIXME: put into fat_dir_entry_* operations */
+void
+fat_traverse_mark_dirty (FatTraverseInfo* trav_info)
+{
+	trav_info->dirty = 1;
+}
+
+FatTraverseInfo*
+fat_traverse_begin (PedFileSystem* fs, FatCluster start_cluster,
+		    const char* dir_name)
+{
+	FatSpecific*		fs_info = FAT_SPECIFIC (fs);
+	FatTraverseInfo*	trav_info;
+
+	trav_info = (FatTraverseInfo*) ped_malloc (sizeof (FatTraverseInfo));
+	if (!trav_info)
+		goto error;
+
+	trav_info->dir_name = strdup (dir_name);
+	if (!trav_info->dir_name)
+		goto error_free_trav_info;
+
+	trav_info->fs = fs;
+	trav_info->is_legacy_root_dir
+		= (fs_info->fat_type == FAT_TYPE_FAT16) && (start_cluster == 0);
+	trav_info->dirty = 0;
+	trav_info->eof = 0;
+	trav_info->current_entry = -1;
+
+	if (trav_info->is_legacy_root_dir) {
+		trav_info->buffer_size = 512 * fs_info->root_dir_sector_count;
+	} else {
+		trav_info->next_buffer = start_cluster;
+		trav_info->buffer_size = fs_info->cluster_size;
+	}
+
+	trav_info->dir_entries
+		= (FatDirEntry*) ped_malloc (trav_info->buffer_size);
+	if (!trav_info->dir_entries)
+		goto error_free_dir_name;
+
+	if (trav_info->is_legacy_root_dir) {
+		if (!ped_geometry_read (fs->geom, trav_info->dir_entries,
+					fs_info->root_dir_offset,
+					fs_info->root_dir_sector_count))
+			goto error_free_dir_entries;
+	} else {
+		if (!read_next_dir_buffer (trav_info))
+			goto error_free_dir_entries;
+	}
+
+	return trav_info;
+
+error_free_dir_entries:
+	free (trav_info->dir_entries);
+error_free_dir_name:
+	free (trav_info->dir_name);
+error_free_trav_info:
+	free (trav_info);
+error:
+	return NULL;
+}
+
+int
+fat_traverse_complete (FatTraverseInfo* trav_info)
+{
+	if (trav_info->dirty) {
+		if (!write_dir_buffer (trav_info))
+			return 0;
+	}
+	free (trav_info->dir_entries);
+	free (trav_info->dir_name);
+	free (trav_info);
+	return 1;
+}
+
+FatTraverseInfo*
+fat_traverse_directory (FatTraverseInfo *trav_info, FatDirEntry* parent)
+{
+	strcpy (tmp_buffer, trav_info->dir_name);
+	fat_dir_entry_get_name (parent,
+				tmp_buffer + strlen (trav_info->dir_name));
+	strcat (tmp_buffer, "\\");
+
+	return fat_traverse_begin (trav_info->fs,
+			fat_dir_entry_get_first_cluster (parent, trav_info->fs),
+			tmp_buffer);
+}
+
+FatDirEntry*
+fat_traverse_next_dir_entry (FatTraverseInfo *trav_info)
+{
+	if (trav_info->eof)
+		return NULL;
+
+	trav_info->current_entry++;
+	if (trav_info->current_entry
+			>= fat_traverse_entries_per_buffer (trav_info)) {
+		if (trav_info->dirty) {
+			if (!write_dir_buffer (trav_info))
+				return NULL;
+		}
+
+		trav_info->current_entry = 0;
+		if (is_last_buffer (trav_info)) {
+			trav_info->eof = 1;
+			return NULL;
+		}
+		if (!read_next_dir_buffer (trav_info))
+			return NULL;
+	}
+	return trav_info->dir_entries + trav_info->current_entry;
+}
+
+FatCluster _GL_ATTRIBUTE_PURE
+fat_dir_entry_get_first_cluster (FatDirEntry* dir_entry, PedFileSystem *fs)
+{
+	FatSpecific*		fs_info = FAT_SPECIFIC (fs);
+
+	switch (fs_info->fat_type) {
+	case FAT_TYPE_FAT12:
+	case FAT_TYPE_FAT16:
+		return PED_LE16_TO_CPU (dir_entry->first_cluster);
+
+        case FAT_TYPE_FAT32:
+		return PED_LE16_TO_CPU (dir_entry->first_cluster_high)
+				* 65536L
+			  + PED_LE16_TO_CPU (dir_entry->first_cluster);
+	}
+
+	return 0;
+}
+
+void
+fat_dir_entry_set_first_cluster (FatDirEntry* dir_entry, PedFileSystem* fs,
+				 FatCluster cluster)
+{
+	FatSpecific*		fs_info = FAT_SPECIFIC (fs);
+
+	switch (fs_info->fat_type) {
+                case FAT_TYPE_FAT12:
+                PED_ASSERT (0);
+                break;
+
+		case FAT_TYPE_FAT16:
+		dir_entry->first_cluster = PED_CPU_TO_LE16 (cluster);
+		break;
+
+		case FAT_TYPE_FAT32:
+		dir_entry->first_cluster
+			= PED_CPU_TO_LE16 (cluster & 0xffff);
+		dir_entry->first_cluster_high
+			= PED_CPU_TO_LE16 (cluster / 0x10000);
+		break;
+	}
+}
+
+uint32_t _GL_ATTRIBUTE_PURE
+fat_dir_entry_get_length (FatDirEntry* dir_entry)
+{
+	return PED_LE32_TO_CPU (dir_entry->length);
+}
+
+int
+fat_dir_entry_is_null_term (const FatDirEntry* dir_entry)
+{
+	FatDirEntry	null_entry;
+
+	memset (&null_entry, 0, sizeof (null_entry));
+	return memcmp (&null_entry, dir_entry, sizeof (null_entry)) == 0;
+}
+
+int _GL_ATTRIBUTE_PURE
+fat_dir_entry_is_active (FatDirEntry* dir_entry)
+{
+	if ((unsigned char) dir_entry->name[0] == DELETED_FLAG) return 0;
+	if ((unsigned char) dir_entry->name[0] == 0) return 0;
+	if ((unsigned char) dir_entry->name[0] == 0xF6) return 0;
+	return 1;
+}
+
+int _GL_ATTRIBUTE_PURE
+fat_dir_entry_is_file (FatDirEntry* dir_entry) {
+	if (dir_entry->attributes == VFAT_ATTR) return 0;
+	if (dir_entry->attributes & VOLUME_LABEL_ATTR) return 0;
+	if (!fat_dir_entry_is_active (dir_entry)) return 0;
+	if ((dir_entry->attributes & DIRECTORY_ATTR) == DIRECTORY_ATTR) return 0;
+	return 1;
+}
+
+int _GL_ATTRIBUTE_PURE
+fat_dir_entry_is_system_file (FatDirEntry* dir_entry)
+{
+	if (!fat_dir_entry_is_file (dir_entry)) return 0;
+	return (dir_entry->attributes & SYSTEM_ATTR)
+		|| (dir_entry->attributes & HIDDEN_ATTR);
+}
+
+int _GL_ATTRIBUTE_PURE
+fat_dir_entry_is_directory (FatDirEntry* dir_entry)
+{
+	if (dir_entry->attributes == VFAT_ATTR) return 0;
+	if (dir_entry->attributes & VOLUME_LABEL_ATTR) return 0;
+	if (!fat_dir_entry_is_active (dir_entry)) return 0;
+	return (dir_entry->attributes & DIRECTORY_ATTR) == DIRECTORY_ATTR;
+}
+
+int
+fat_dir_entry_has_first_cluster (FatDirEntry* dir_entry, PedFileSystem* fs)
+{
+	FatSpecific*	fs_info = FAT_SPECIFIC (fs);
+	FatCluster	first_cluster;
+
+	if (!fat_dir_entry_is_file (dir_entry)
+		&& !fat_dir_entry_is_directory (dir_entry))
+		return 0;
+
+	first_cluster = fat_dir_entry_get_first_cluster (dir_entry, fs);
+	if (first_cluster == 0
+		|| fat_table_is_eof (fs_info->fat, first_cluster))
+		return 0;
+
+	return 1;
+}
+
+/*
+    decrypts silly DOS names to FILENAME.EXT
+*/
+void
+fat_dir_entry_get_name (const FatDirEntry *dir_entry, char *result) {
+	size_t i;
+	const char *src;
+	const char *ext;
+
+	src = dir_entry->name;
+
+	for (i=0; i < sizeof dir_entry->name; i++) {
+		if (src[i] == ' ' || src[i] == 0) break;
+		*result++ = src[i];
+	}
+
+	ext = (const char *) dir_entry->extension;
+	if (ext[0] != ' ' && ext[0] != 0) {
+		*result++ = '.';
+		for (i=0; i < sizeof dir_entry->extension; i++) {
+			if (ext[i] == ' ' || ext[i] == 0) break;
+			*result++ = ext[i];
+		}
+	}
+
+	*result = 0;
+}
+
+#endif /* !DISCOVER_ONLY */
diff --git a/libparted/fs/r/fat/traverse.h b/libparted/fs/r/fat/traverse.h
new file mode 100644
index 0000000..02318ba
--- /dev/null
+++ b/libparted/fs/r/fat/traverse.h
@@ -0,0 +1,75 @@
+/*
+    libparted
+    Copyright (C) 1998-2000, 2007-2014, 2019-2023 Free Software Foundation,
+    Inc.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef TRAVERSE_H_INCLUDED
+#define TRAVERSE_H_INCLUDED
+
+#include "fatio.h"
+
+typedef struct _FatTraverseInfo		FatTraverseInfo;
+
+struct _FatTraverseInfo {
+	PedFileSystem*		fs;
+	char*			dir_name;
+
+	int			is_legacy_root_dir;
+	int			dirty;
+	int			eof;
+
+	FatDirEntry*		dir_entries;
+	int			current_entry;
+	FatCluster		this_buffer, next_buffer;
+	int			buffer_size;
+};
+
+extern int fat_traverse_entries_per_buffer (FatTraverseInfo* trav_info);
+
+/* starts traversal at an arbitary cluster.  if start_cluster==0, then uses
+   root directory */
+extern FatTraverseInfo* fat_traverse_begin (PedFileSystem* fs,
+					    FatCluster start_cluster,
+					    const char* dir_name);
+
+extern int fat_traverse_complete (FatTraverseInfo* trav_info);
+
+extern FatTraverseInfo* fat_traverse_directory (FatTraverseInfo* trav_info,
+						FatDirEntry* parent);
+
+extern void fat_traverse_mark_dirty (FatTraverseInfo* trav_info);
+
+extern FatDirEntry* fat_traverse_next_dir_entry (FatTraverseInfo* trav_info);
+
+extern FatCluster fat_dir_entry_get_first_cluster (FatDirEntry* dir_entry,
+						   PedFileSystem* fs);
+
+extern void fat_dir_entry_set_first_cluster (FatDirEntry* dir_entry,
+					PedFileSystem* fs, FatCluster cluster);
+
+extern uint32_t fat_dir_entry_get_length (FatDirEntry* dir_entry);
+
+extern int fat_dir_entry_is_null_term (const FatDirEntry* dir_entry);
+extern int fat_dir_entry_is_file (FatDirEntry* dir_entry);
+extern int fat_dir_entry_is_system_file (FatDirEntry* dir_entry);
+extern int fat_dir_entry_is_directory (FatDirEntry* dir_entry);
+extern void fat_dir_entry_get_name (const FatDirEntry* dir_entry, char* result);
+extern int fat_dir_entry_is_active (FatDirEntry* dir_entry);
+extern int fat_dir_entry_has_first_cluster (FatDirEntry* dir_entry,
+					    PedFileSystem* fs);
+
+#endif /* TRAVERSE_H_INCLUDED */