Adding upstream version 2.38.1.upstream/2.38.1upstream

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

1 files changed, 3351 insertions, 0 deletions

diff --git a/libfdisk/src/gpt.c b/libfdisk/src/gpt.c
new file mode 100644
index 0000000..72370a1
--- /dev/null
+++ b/libfdisk/src/gpt.c
@@ -0,0 +1,3351 @@
+/*
+ * Copyright (C) 2007 Karel Zak <kzak@redhat.com>
+ * Copyright (C) 2012 Davidlohr Bueso <dave@gnu.org>
+ *
+ * GUID Partition Table (GPT) support. Based on UEFI Specs 2.3.1
+ * Chapter 5: GUID Partition Table (GPT) Disk Layout (Jun 27th, 2012).
+ * Some ideas and inspiration from GNU parted and gptfdisk.
+ */
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <inttypes.h>
+#include <stdint.h>
+#include <sys/stat.h>
+#include <sys/utsname.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+#include <ctype.h>
+#include <uuid.h>
+
+#include "fdiskP.h"
+
+#include "crc32.h"
+#include "blkdev.h"
+#include "bitops.h"
+#include "strutils.h"
+#include "all-io.h"
+#include "pt-mbr.h"
+#include "encode.h"
+
+/**
+ * SECTION: gpt
+ * @title: UEFI GPT
+ * @short_description: specific functionality
+ */
+
+#define GPT_HEADER_SIGNATURE 0x5452415020494645LL /* EFI PART */
+#define GPT_HEADER_REVISION_V1_02 0x00010200
+#define GPT_HEADER_REVISION_V1_00 0x00010000
+#define GPT_HEADER_REVISION_V0_99 0x00009900
+#define GPT_HEADER_MINSZ          92 /* bytes */
+
+#define GPT_PMBR_LBA        0
+#define GPT_MBR_PROTECTIVE  1
+#define GPT_MBR_HYBRID      2
+
+#define GPT_PRIMARY_PARTITION_TABLE_LBA 0x00000001ULL
+
+#define EFI_PMBR_OSTYPE     0xEE
+#define MSDOS_MBR_SIGNATURE 0xAA55
+#define GPT_PART_NAME_LEN   (72 / sizeof(uint16_t))
+#define GPT_NPARTITIONS     ((size_t) FDISK_GPT_NPARTITIONS_DEFAULT)
+
+/* Globally unique identifier */
+struct gpt_guid {
+	uint32_t   time_low;
+	uint16_t   time_mid;
+	uint16_t   time_hi_and_version;
+	uint8_t    clock_seq_hi;
+	uint8_t    clock_seq_low;
+	uint8_t    node[6];
+};
+
+
+/* only checking that the GUID is 0 is enough to verify an empty partition. */
+#define GPT_UNUSED_ENTRY_GUID						\
+	((struct gpt_guid) { 0x00000000, 0x0000, 0x0000, 0x00, 0x00,	\
+			     { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }})
+
+/* Linux native partition type */
+#define GPT_DEFAULT_ENTRY_TYPE "0FC63DAF-8483-4772-8E79-3D69D8477DE4"
+
+/*
+ * Attribute bits
+ */
+enum {
+	/* UEFI specific */
+	GPT_ATTRBIT_REQ      = 0,
+	GPT_ATTRBIT_NOBLOCK  = 1,
+	GPT_ATTRBIT_LEGACY   = 2,
+
+	/* GUID specific (range 48..64)*/
+	GPT_ATTRBIT_GUID_FIRST	= 48,
+	GPT_ATTRBIT_GUID_COUNT	= 16
+};
+
+#define GPT_ATTRSTR_REQ		"RequiredPartition"
+#define GPT_ATTRSTR_REQ_TYPO	"RequiredPartiton"
+#define GPT_ATTRSTR_NOBLOCK	"NoBlockIOProtocol"
+#define GPT_ATTRSTR_LEGACY	"LegacyBIOSBootable"
+
+/* The GPT Partition entry array contains an array of GPT entries. */
+struct gpt_entry {
+	struct gpt_guid     type; /* purpose and type of the partition */
+	struct gpt_guid     partition_guid;
+	uint64_t            lba_start;
+	uint64_t            lba_end;
+	uint64_t            attrs;
+	uint16_t            name[GPT_PART_NAME_LEN];
+}  __attribute__ ((packed));
+
+/* GPT header */
+struct gpt_header {
+	uint64_t            signature; /* header identification */
+	uint32_t            revision; /* header version */
+	uint32_t            size; /* in bytes */
+	uint32_t            crc32; /* header CRC checksum */
+	uint32_t            reserved1; /* must be 0 */
+	uint64_t            my_lba; /* LBA of block that contains this struct (LBA 1) */
+	uint64_t            alternative_lba; /* backup GPT header */
+	uint64_t            first_usable_lba; /* first usable logical block for partitions */
+	uint64_t            last_usable_lba; /* last usable logical block for partitions */
+	struct gpt_guid     disk_guid; /* unique disk identifier */
+	uint64_t            partition_entry_lba; /* LBA of start of partition entries array */
+	uint32_t            npartition_entries; /* total partition entries - normally 128 */
+	uint32_t            sizeof_partition_entry; /* bytes for each GUID pt */
+	uint32_t            partition_entry_array_crc32; /* partition CRC checksum */
+	uint8_t             reserved2[512 - 92]; /* must all be 0 */
+} __attribute__ ((packed));
+
+struct gpt_record {
+	uint8_t             boot_indicator; /* unused by EFI, set to 0x80 for bootable */
+	uint8_t             start_head; /* unused by EFI, pt start in CHS */
+	uint8_t             start_sector; /* unused by EFI, pt start in CHS */
+	uint8_t             start_track;
+	uint8_t             os_type; /* EFI and legacy non-EFI OS types */
+	uint8_t             end_head; /* unused by EFI, pt end in CHS */
+	uint8_t             end_sector; /* unused by EFI, pt end in CHS */
+	uint8_t             end_track; /* unused by EFI, pt end in CHS */
+	uint32_t            starting_lba; /* used by EFI - start addr of the on disk pt */
+	uint32_t            size_in_lba; /* used by EFI - size of pt in LBA */
+} __attribute__ ((packed));
+
+/* Protected MBR and legacy MBR share same structure */
+struct gpt_legacy_mbr {
+	uint8_t             boot_code[440];
+	uint32_t            unique_mbr_signature;
+	uint16_t            unknown;
+	struct gpt_record   partition_record[4];
+	uint16_t            signature;
+} __attribute__ ((packed));
+
+/*
+ * Here be dragons!
+ * See: http://en.wikipedia.org/wiki/GUID_Partition_Table#Partition_type_GUIDs
+ */
+#define DEF_GUID(_u, _n) \
+	{ \
+		.typestr = (_u), \
+		.name = (_n),    \
+	}
+
+static struct fdisk_parttype gpt_parttypes[] =
+{
+	#include "pt-gpt-partnames.h"
+};
+
+static const struct fdisk_shortcut gpt_parttype_cuts[] =
+{
+	{ .shortcut = "L", .alias = "linux", .data = "0FC63DAF-8483-4772-8E79-3D69D8477DE4" }, /* Linux */
+	{ .shortcut = "S", .alias = "swap",  .data = "0657FD6D-A4AB-43C4-84E5-0933C84B4F4F" }, /* Swap */
+	{ .shortcut = "H", .alias = "home",  .data = "933AC7E1-2EB4-4F13-B844-0E14E2AEF915" }, /* Home */
+	{ .shortcut = "U", .alias = "uefi",  .data = "C12A7328-F81F-11D2-BA4B-00A0C93EC93B" }, /* UEFI system */
+	{ .shortcut = "R", .alias = "raid",  .data = "A19D880F-05FC-4D3B-A006-743F0F84911E" }, /* Linux RAID */
+	{ .shortcut = "V", .alias = "lvm",   .data = "E6D6D379-F507-44C2-A23C-238F2A3DF928" }  /* LVM */
+};
+
+#define alignment_required(_x)  ((_x)->grain != (_x)->sector_size)
+
+/* gpt_entry macros */
+#define gpt_partition_start(_e)		le64_to_cpu((_e)->lba_start)
+#define gpt_partition_end(_e)		le64_to_cpu((_e)->lba_end)
+
+/*
+ * in-memory fdisk GPT stuff
+ */
+struct fdisk_gpt_label {
+	struct fdisk_label	head;		/* generic part */
+
+	/* gpt specific part */
+	struct gpt_header	*pheader;	/* primary header */
+	struct gpt_header	*bheader;	/* backup header */
+
+	unsigned char *ents;			/* entries (partitions) */
+
+	unsigned int no_relocate :1,		/* do not fix backup location */
+		     minimize :1;
+};
+
+static void gpt_deinit(struct fdisk_label *lb);
+
+static inline struct fdisk_gpt_label *self_label(struct fdisk_context *cxt)
+{
+	return (struct fdisk_gpt_label *) cxt->label;
+}
+
+/*
+ * Returns the partition length, or 0 if end is before beginning.
+ */
+static uint64_t gpt_partition_size(const struct gpt_entry *e)
+{
+	uint64_t start = gpt_partition_start(e);
+	uint64_t end = gpt_partition_end(e);
+
+	return start > end ? 0 : end - start + 1ULL;
+}
+
+/* prints UUID in the real byte order! */
+static void gpt_debug_uuid(const char *mesg, struct gpt_guid *guid)
+{
+	const unsigned char *uuid = (unsigned char *) guid;
+
+	fprintf(stderr, "%s: "
+		"%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x\n",
+		mesg,
+		uuid[0], uuid[1], uuid[2], uuid[3],
+		uuid[4], uuid[5],
+		uuid[6], uuid[7],
+		uuid[8], uuid[9],
+		uuid[10], uuid[11], uuid[12], uuid[13], uuid[14],uuid[15]);
+}
+
+/*
+ * UUID is traditionally 16 byte big-endian array, except Intel EFI
+ * specification where the UUID is a structure of little-endian fields.
+ */
+static void swap_efi_guid(struct gpt_guid *uid)
+{
+	uid->time_low = swab32(uid->time_low);
+	uid->time_mid = swab16(uid->time_mid);
+	uid->time_hi_and_version = swab16(uid->time_hi_and_version);
+}
+
+static int string_to_guid(const char *in, struct gpt_guid *guid)
+{
+	if (uuid_parse(in, (unsigned char *) guid)) {   /* BE */
+		DBG(GPT, ul_debug("failed to parse GUID: %s", in));
+		return -EINVAL;
+	}
+	swap_efi_guid(guid);				/* LE */
+	return 0;
+}
+
+static char *guid_to_string(const struct gpt_guid *guid, char *out)
+{
+	struct gpt_guid u = *guid;	/* LE */
+
+	swap_efi_guid(&u);		/* BE */
+	uuid_unparse_upper((unsigned char *) &u, out);
+
+	return out;
+}
+
+static struct fdisk_parttype *gpt_partition_parttype(
+		struct fdisk_context *cxt,
+		const struct gpt_entry *e)
+{
+	struct fdisk_parttype *t;
+	char str[UUID_STR_LEN];
+	struct gpt_guid guid = e->type;
+
+	guid_to_string(&guid, str);
+	t = fdisk_label_get_parttype_from_string(cxt->label, str);
+	return t ? : fdisk_new_unknown_parttype(0, str);
+}
+
+static void gpt_entry_set_type(struct gpt_entry *e, struct gpt_guid *uuid)
+{
+	e->type = *uuid;
+	DBG(GPT, gpt_debug_uuid("new type", uuid));
+}
+
+static int gpt_entry_set_name(struct gpt_entry *e, char *str)
+{
+	uint16_t name[GPT_PART_NAME_LEN] = { 0 };
+	size_t i, mblen = 0;
+	uint8_t *in = (uint8_t *) str;
+
+	for (i = 0; *in && i < GPT_PART_NAME_LEN; in++) {
+		if (!mblen) {
+			if (!(*in & 0x80)) {
+				name[i++] = *in;
+			} else if ((*in & 0xE0) == 0xC0) {
+				mblen = 1;
+				name[i] = (uint16_t)(*in & 0x1F) << (mblen *6);
+			} else if ((*in & 0xF0) == 0xE0) {
+				mblen = 2;
+				name[i] = (uint16_t)(*in & 0x0F) << (mblen *6);
+			} else {
+				/* broken UTF-8 or code point greater than U+FFFF */
+				return -EILSEQ;
+			}
+		} else {
+			/* incomplete UTF-8 sequence */
+			if ((*in & 0xC0) != 0x80)
+				return -EILSEQ;
+
+			name[i] |= (uint16_t)(*in & 0x3F) << (--mblen *6);
+			if (!mblen) {
+				/* check for code points reserved for surrogate pairs*/
+				if ((name[i] & 0xF800) == 0xD800)
+					return -EILSEQ;
+				i++;
+			}
+		}
+	}
+
+	for (i = 0; i < GPT_PART_NAME_LEN; i++)
+		e->name[i] = cpu_to_le16(name[i]);
+
+	return (int)((char *) in - str);
+}
+
+static int gpt_entry_set_uuid(struct gpt_entry *e, char *str)
+{
+	struct gpt_guid uuid;
+	int rc;
+
+	rc = string_to_guid(str, &uuid);
+	if (rc)
+		return rc;
+
+	e->partition_guid = uuid;
+	return 0;
+}
+
+static inline int gpt_entry_is_used(const struct gpt_entry *e)
+{
+	return memcmp(&e->type, &GPT_UNUSED_ENTRY_GUID,
+			sizeof(struct gpt_guid)) != 0;
+}
+
+
+static const char *gpt_get_header_revstr(struct gpt_header *header)
+{
+	if (!header)
+		goto unknown;
+
+	switch (le32_to_cpu(header->revision)) {
+	case GPT_HEADER_REVISION_V1_02:
+		return "1.2";
+	case GPT_HEADER_REVISION_V1_00:
+		return "1.0";
+	case GPT_HEADER_REVISION_V0_99:
+		return "0.99";
+	default:
+		goto unknown;
+	}
+
+unknown:
+	return "unknown";
+}
+
+static inline unsigned char *gpt_get_entry_ptr(struct fdisk_gpt_label *gpt, size_t i)
+{
+	return gpt->ents + le32_to_cpu(gpt->pheader->sizeof_partition_entry) * i;
+}
+
+static inline struct gpt_entry *gpt_get_entry(struct fdisk_gpt_label *gpt, size_t i)
+{
+	return (struct gpt_entry *) gpt_get_entry_ptr(gpt, i);
+}
+
+static inline struct gpt_entry *gpt_zeroize_entry(struct fdisk_gpt_label *gpt, size_t i)
+{
+	return (struct gpt_entry *) memset(gpt_get_entry_ptr(gpt, i),
+			0, le32_to_cpu(gpt->pheader->sizeof_partition_entry));
+}
+
+/* Use to access array of entries, for() loops, etc. But don't use when
+ * you directly do something with GPT header, then use uint32_t.
+ */
+static inline size_t gpt_get_nentries(struct fdisk_gpt_label *gpt)
+{
+	return (size_t) le32_to_cpu(gpt->pheader->npartition_entries);
+}
+
+/* calculate size of entries array in bytes for specified number of entries */
+static inline int gpt_calculate_sizeof_entries(
+				struct gpt_header *hdr,
+				uint32_t nents,	size_t *sz)
+{
+	uint32_t esz = hdr ? le32_to_cpu(hdr->sizeof_partition_entry) :
+			     sizeof(struct gpt_entry);
+
+	if (nents == 0 || esz == 0 || SIZE_MAX/esz < nents) {
+		DBG(GPT, ul_debug("entries array size check failed"));
+		return -ERANGE;
+	}
+
+	*sz = (size_t) nents * esz;
+	return 0;
+}
+
+/* calculate size of entries array in sectors for specified number of entries */
+static inline int gpt_calculate_sectorsof_entries(
+				struct gpt_header *hdr,
+				uint32_t nents, uint64_t *sz,
+				struct fdisk_context *cxt)
+{
+	size_t esz = 0;
+	int rc = gpt_calculate_sizeof_entries(hdr, nents, &esz);	/* in bytes */
+
+	if (rc == 0)
+		*sz = (esz + cxt->sector_size - 1) / cxt->sector_size;
+	return rc;
+}
+
+/* calculate alternative (backup) entries array offset from primary header */
+static inline int gpt_calculate_alternative_entries_lba(
+				struct gpt_header *hdr,
+				uint32_t nents,
+				uint64_t *sz,
+				struct fdisk_context *cxt)
+{
+	uint64_t esects = 0;
+	int rc = gpt_calculate_sectorsof_entries(hdr, nents, &esects, cxt);
+
+	if (rc)
+		return rc;
+	if (cxt->total_sectors < 1ULL + esects)
+		return -ENOSPC;
+
+	*sz = cxt->total_sectors - 1ULL - esects;
+	return 0;
+}
+
+static inline int gpt_calculate_last_lba(
+				struct gpt_header *hdr,
+				uint32_t nents,
+				uint64_t *sz,
+				struct fdisk_context *cxt)
+{
+	uint64_t esects = 0;
+	int rc = gpt_calculate_sectorsof_entries(hdr, nents, &esects, cxt);
+
+	if (rc)
+		return rc;
+	if (cxt->total_sectors < 2ULL + esects)
+		return -ENOSPC;
+
+	*sz = cxt->total_sectors - 2ULL - esects;
+	return 0;
+}
+
+static inline int gpt_calculate_first_lba(
+				struct gpt_header *hdr,
+				uint32_t nents,
+				uint64_t *sz,
+				struct fdisk_context *cxt)
+{
+	uint64_t esects = 0;
+	int rc = gpt_calculate_sectorsof_entries(hdr, nents, &esects, cxt);
+
+	if (rc == 0)
+		*sz = esects + 2ULL;
+	return rc;
+}
+
+/* the current size of entries array in bytes */
+static inline int gpt_sizeof_entries(struct gpt_header *hdr, size_t *sz)
+{
+	return gpt_calculate_sizeof_entries(hdr, le32_to_cpu(hdr->npartition_entries), sz);
+}
+
+static char *gpt_get_header_id(struct gpt_header *header)
+{
+	char str[UUID_STR_LEN];
+	struct gpt_guid guid = header->disk_guid;
+
+	guid_to_string(&guid, str);
+
+	return strdup(str);
+}
+
+/*
+ * Builds a clean new valid protective MBR - will wipe out any existing data.
+ * Returns 0 on success, otherwise < 0 on error.
+ */
+static int gpt_mknew_pmbr(struct fdisk_context *cxt)
+{
+	struct gpt_legacy_mbr *pmbr = NULL;
+	int rc;
+
+	if (!cxt || !cxt->firstsector)
+		return -ENOSYS;
+
+	if (fdisk_has_protected_bootbits(cxt))
+		rc = fdisk_init_firstsector_buffer(cxt, 0, MBR_PT_BOOTBITS_SIZE);
+	else
+		rc = fdisk_init_firstsector_buffer(cxt, 0, 0);
+	if (rc)
+		return rc;
+
+	pmbr = (struct gpt_legacy_mbr *) cxt->firstsector;
+	memset(pmbr->partition_record, 0, sizeof(pmbr->partition_record));
+
+	pmbr->signature = cpu_to_le16(MSDOS_MBR_SIGNATURE);
+	pmbr->partition_record[0].os_type      = EFI_PMBR_OSTYPE;
+	pmbr->partition_record[0].start_sector = 2;
+	pmbr->partition_record[0].end_head     = 0xFF;
+	pmbr->partition_record[0].end_sector   = 0xFF;
+	pmbr->partition_record[0].end_track    = 0xFF;
+	pmbr->partition_record[0].starting_lba = cpu_to_le32(1);
+	pmbr->partition_record[0].size_in_lba  =
+		cpu_to_le32((uint32_t) min( cxt->total_sectors - 1ULL, 0xFFFFFFFFULL) );
+
+	return 0;
+}
+
+
+/* Move backup header to the end of the device */
+static int gpt_fix_alternative_lba(struct fdisk_context *cxt, struct fdisk_gpt_label *gpt)
+{
+	struct gpt_header *p, *b;
+	uint64_t x = 0, orig;
+	size_t nents;
+	int rc;
+
+	if (!cxt)
+		return -EINVAL;
+
+	p = gpt->pheader;	/* primary */
+	b = gpt->bheader;	/* backup */
+
+	nents = le32_to_cpu(p->npartition_entries);
+	orig = le64_to_cpu(p->alternative_lba);
+
+	/* reference from primary to backup */
+	p->alternative_lba = cpu_to_le64(cxt->total_sectors - 1ULL);
+
+	/* reference from backup to primary */
+	b->alternative_lba = p->my_lba;
+	b->my_lba = p->alternative_lba;
+
+	/* fix backup partitions array address */
+	rc = gpt_calculate_alternative_entries_lba(p, nents, &x, cxt);
+	if (rc)
+		goto failed;
+
+	b->partition_entry_lba = cpu_to_le64(x);
+
+	/* update last usable LBA */
+	rc = gpt_calculate_last_lba(p, nents, &x, cxt);
+	if (rc)
+		goto failed;
+
+	p->last_usable_lba  = cpu_to_le64(x);
+	b->last_usable_lba  = cpu_to_le64(x);
+
+	DBG(GPT, ul_debug("Alternative-LBA updated from %"PRIu64" to %"PRIu64,
+				orig, le64_to_cpu(p->alternative_lba)));
+	return 0;
+failed:
+	DBG(GPT, ul_debug("failed to fix alternative-LBA [rc=%d]", rc));
+	return rc;
+}
+
+static uint64_t gpt_calculate_minimal_size(struct fdisk_context *cxt, struct fdisk_gpt_label *gpt)
+{
+	size_t i;
+	uint64_t x = 0, total = 0;
+	struct gpt_header *hdr;
+
+	assert(cxt);
+	assert(gpt);
+	assert(gpt->pheader);
+	assert(gpt->ents);
+
+	hdr = gpt->pheader;
+
+	/* LBA behind the last partition */
+	for (i = 0; i < gpt_get_nentries(gpt); i++) {
+		struct gpt_entry *e = gpt_get_entry(gpt, i);
+
+		if (gpt_entry_is_used(e)) {
+			uint64_t end = gpt_partition_end(e);
+			if (end > x)
+				x = end;
+		}
+	}
+	total = x + 1;
+
+	/* the current last LBA usable for partitions */
+	gpt_calculate_last_lba(hdr, le32_to_cpu(hdr->npartition_entries), &x, cxt);
+
+	/* size of all stuff at the end of the device */
+	total += cxt->total_sectors - x;
+
+	DBG(GPT, ul_debug("minimal device is %"PRIu64, total));
+	return total;
+}
+
+static int gpt_possible_minimize(struct fdisk_context *cxt, struct fdisk_gpt_label *gpt)
+{
+	struct gpt_header *hdr = gpt->pheader;
+	uint64_t total = gpt_calculate_minimal_size(cxt, gpt);
+
+	return le64_to_cpu(hdr->alternative_lba) > (total - 1ULL);
+}
+
+/* move backup header behind the last partition */
+static int gpt_minimize_alternative_lba(struct fdisk_context *cxt, struct fdisk_gpt_label *gpt)
+{
+	uint64_t total = gpt_calculate_minimal_size(cxt, gpt);
+	uint64_t orig = cxt->total_sectors;
+	int rc;
+
+	/* Let's temporary change size of the device to recalculate backup header */
+	cxt->total_sectors = total;
+	rc = gpt_fix_alternative_lba(cxt, gpt);
+	if (rc)
+		return rc;
+
+	cxt->total_sectors = orig;
+	fdisk_label_set_changed(cxt->label, 1);
+	return 0;
+}
+
+/* some universal differences between the headers */
+static void gpt_mknew_header_common(struct fdisk_context *cxt,
+				    struct gpt_header *header, uint64_t lba)
+{
+	if (!cxt || !header)
+		return;
+
+	header->my_lba = cpu_to_le64(lba);
+
+	if (lba == GPT_PRIMARY_PARTITION_TABLE_LBA) {
+		/* primary */
+		header->alternative_lba = cpu_to_le64(cxt->total_sectors - 1ULL);
+		header->partition_entry_lba = cpu_to_le64(2ULL);
+
+	} else {
+		/* backup */
+		uint64_t x = 0;
+		gpt_calculate_alternative_entries_lba(header,
+				le32_to_cpu(header->npartition_entries), &x, cxt);
+
+		header->alternative_lba = cpu_to_le64(GPT_PRIMARY_PARTITION_TABLE_LBA);
+		header->partition_entry_lba = cpu_to_le64(x);
+	}
+}
+
+/*
+ * Builds a new GPT header (at sector lba) from a backup header2.
+ * If building a primary header, then backup is the secondary, and vice versa.
+ *
+ * Always pass a new (zeroized) header to build upon as we don't
+ * explicitly zero-set some values such as CRCs and reserved.
+ *
+ * Returns 0 on success, otherwise < 0 on error.
+ */
+static int gpt_mknew_header_from_bkp(struct fdisk_context *cxt,
+				     struct gpt_header *header,
+				     uint64_t lba,
+				     struct gpt_header *header2)
+{
+	if (!cxt || !header || !header2)
+		return -ENOSYS;
+
+	header->signature              = header2->signature;
+	header->revision               = header2->revision;
+	header->size                   = header2->size;
+	header->npartition_entries     = header2->npartition_entries;
+	header->sizeof_partition_entry = header2->sizeof_partition_entry;
+	header->first_usable_lba       = header2->first_usable_lba;
+	header->last_usable_lba        = header2->last_usable_lba;
+
+	memcpy(&header->disk_guid,
+	       &header2->disk_guid, sizeof(header2->disk_guid));
+	gpt_mknew_header_common(cxt, header, lba);
+
+	return 0;
+}
+
+static struct gpt_header *gpt_copy_header(struct fdisk_context *cxt,
+			   struct gpt_header *src)
+{
+	struct gpt_header *res;
+
+	if (!cxt || !src)
+		return NULL;
+
+	assert(cxt->sector_size >= sizeof(struct gpt_header));
+
+	res = calloc(1, cxt->sector_size);
+	if (!res) {
+		fdisk_warn(cxt, _("failed to allocate GPT header"));
+		return NULL;
+	}
+
+	res->my_lba                 = src->alternative_lba;
+	res->alternative_lba        = src->my_lba;
+
+	res->signature              = src->signature;
+	res->revision               = src->revision;
+	res->size                   = src->size;
+	res->npartition_entries     = src->npartition_entries;
+	res->sizeof_partition_entry = src->sizeof_partition_entry;
+	res->first_usable_lba       = src->first_usable_lba;
+	res->last_usable_lba        = src->last_usable_lba;
+
+	memcpy(&res->disk_guid, &src->disk_guid, sizeof(src->disk_guid));
+
+
+	if (res->my_lba == GPT_PRIMARY_PARTITION_TABLE_LBA)
+		res->partition_entry_lba = cpu_to_le64(2ULL);
+	else {
+		uint64_t esz = (uint64_t) le32_to_cpu(src->npartition_entries) * sizeof(struct gpt_entry);
+		uint64_t esects = (esz + cxt->sector_size - 1) / cxt->sector_size;
+
+		res->partition_entry_lba = cpu_to_le64(cxt->total_sectors - 1ULL - esects);
+	}
+
+	return res;
+}
+
+static int get_script_u64(struct fdisk_context *cxt, uint64_t *num, const char *name)
+{
+	const char *str;
+	int pwr = 0, rc = 0;
+
+	assert(cxt);
+
+	*num = 0;
+
+	if (!cxt->script)
+		return 1;
+
+	str = fdisk_script_get_header(cxt->script, name);
+	if (!str)
+		return 1;
+
+	rc = parse_size(str, (uintmax_t *) num, &pwr);
+	if (rc < 0)
+		return rc;
+	if (pwr)
+		*num /= cxt->sector_size;
+	return 0;
+}
+
+static int count_first_last_lba(struct fdisk_context *cxt,
+				 uint64_t *first, uint64_t *last,
+				 uint32_t *maxents)
+{
+	int rc = 0;
+	uint64_t flba = 0, llba = 0;
+	uint64_t nents = GPT_NPARTITIONS;
+
+	assert(cxt);
+	assert(first);
+	assert(last);
+
+	*first = *last = 0;
+
+	/* Get the table length from the script, if given */
+	if (cxt->script) {
+		rc = get_script_u64(cxt, &nents, "table-length");
+		if (rc == 1)
+			nents = GPT_NPARTITIONS;  /* undefined by script */
+		else if (rc < 0)
+			return rc;
+	}
+
+	/* The table length was not changed by the script, compute it. */
+	if (flba == 0) {
+		/* If the device is not large enough reduce this number of
+		 * partitions and try to recalculate it again, until we get
+		 * something useful or return error.
+		 */
+		for (; nents > 0; nents--) {
+			rc = gpt_calculate_last_lba(NULL, nents, &llba, cxt);
+			if (rc == 0)
+				rc = gpt_calculate_first_lba(NULL, nents, &flba, cxt);
+			if (llba < flba)
+				rc = -ENOSPC;
+			else if (rc == 0)
+				break;
+		}
+	}
+
+	if (rc)
+		return rc;
+	if (maxents)
+		*maxents = nents;
+
+	/* script default */
+	if (cxt->script) {
+		rc = get_script_u64(cxt, first, "first-lba");
+		if (rc < 0)
+			return rc;
+
+		DBG(GPT, ul_debug("FirstLBA: script=%"PRIu64", uefi=%"PRIu64", topology=%ju.",
+		                    *first, flba,  (uintmax_t)cxt->first_lba));
+
+		if (rc == 0 && (*first < flba || *first > llba)) {
+			fdisk_warnx(cxt, _("First LBA specified by script is out of range."));
+			return -ERANGE;
+		}
+
+		rc = get_script_u64(cxt, last, "last-lba");
+		if (rc < 0)
+			return rc;
+
+		DBG(GPT, ul_debug("LastLBA: script=%"PRIu64", uefi=%"PRIu64", topology=%ju.",
+		                    *last, llba,  (uintmax_t)cxt->last_lba));
+
+		if (rc == 0 && (*last > llba || *last < flba)) {
+			fdisk_warnx(cxt, _("Last LBA specified by script is out of range."));
+			return -ERANGE;
+		}
+	}
+
+	if (!*last)
+		*last = llba;
+
+	/* default by topology */
+	if (!*first)
+		*first = flba < cxt->first_lba &&
+			 cxt->first_lba < *last ? cxt->first_lba : flba;
+	return 0;
+}
+
+/*
+ * Builds a clean new GPT header (currently under revision 1.0).
+ *
+ * Always pass a new (zeroized) header to build upon as we don't
+ * explicitly zero-set some values such as CRCs and reserved.
+ *
+ * Returns 0 on success, otherwise < 0 on error.
+ */
+static int gpt_mknew_header(struct fdisk_context *cxt,
+			    struct gpt_header *header, uint64_t lba)
+{
+	uint64_t first, last;
+	uint32_t nents = 0;
+	int has_id = 0, rc;
+
+	if (!cxt || !header)
+		return -ENOSYS;
+
+	header->signature = cpu_to_le64(GPT_HEADER_SIGNATURE);
+	header->revision  = cpu_to_le32(GPT_HEADER_REVISION_V1_00);
+
+	/* According to EFI standard it's valid to count all the first
+	 * sector into header size, but some tools may have a problem
+	 * to accept it, so use the header without the zeroed area.
+	 * This does not have any impact to CRC, etc.   --kzak Jan-2015
+	 */
+	header->size = cpu_to_le32(sizeof(struct gpt_header)
+				- sizeof(header->reserved2));
+
+	/* Set {First,Last}LBA and number of the partitions
+	 * (default is GPT_NPARTITIONS) */
+	rc = count_first_last_lba(cxt, &first, &last, &nents);
+	if (rc)
+		return rc;
+
+	header->npartition_entries     = cpu_to_le32(nents);
+	header->sizeof_partition_entry = cpu_to_le32(sizeof(struct gpt_entry));
+
+	header->first_usable_lba = cpu_to_le64(first);
+	header->last_usable_lba  = cpu_to_le64(last);
+
+	gpt_mknew_header_common(cxt, header, lba);
+
+	if (cxt->script) {
+		const char *id = fdisk_script_get_header(cxt->script, "label-id");
+		struct gpt_guid guid = header->disk_guid;
+		if (id && string_to_guid(id, &guid) == 0)
+			has_id = 1;
+		header->disk_guid = guid;
+	}
+
+	if (!has_id) {
+		struct gpt_guid guid;
+
+		uuid_generate_random((unsigned char *) &header->disk_guid);
+		guid = header->disk_guid;
+		swap_efi_guid(&guid);
+	}
+	return 0;
+}
+
+/*
+ * Checks if there is a valid protective MBR partition table.
+ * Returns 0 if it is invalid or failure. Otherwise, return
+ * GPT_MBR_PROTECTIVE or GPT_MBR_HYBRID, depending on the detection.
+ */
+static int valid_pmbr(struct fdisk_context *cxt)
+{
+	int i, part = 0, ret = 0; /* invalid by default */
+	struct gpt_legacy_mbr *pmbr = NULL;
+
+	if (!cxt->firstsector)
+		goto done;
+
+	pmbr = (struct gpt_legacy_mbr *) cxt->firstsector;
+
+	if (le16_to_cpu(pmbr->signature) != MSDOS_MBR_SIGNATURE)
+		goto done;
+
+	/* seems like a valid MBR was found, check DOS primary partitions */
+	for (i = 0; i < 4; i++) {
+		if (pmbr->partition_record[i].os_type == EFI_PMBR_OSTYPE) {
+			/*
+			 * Ok, we at least know that there's a protective MBR,
+			 * now check if there are other partition types for
+			 * hybrid MBR.
+			 */
+			part = i;
+			ret = GPT_MBR_PROTECTIVE;
+			break;
+		}
+	}
+
+	if (ret != GPT_MBR_PROTECTIVE)
+		goto done;
+
+
+	for (i = 0 ; i < 4; i++) {
+		if ((pmbr->partition_record[i].os_type != EFI_PMBR_OSTYPE) &&
+		    (pmbr->partition_record[i].os_type != 0x00)) {
+			ret = GPT_MBR_HYBRID;
+			goto done;
+		}
+	}
+
+	/* LBA of the GPT partition header */
+	if (pmbr->partition_record[part].starting_lba !=
+	    cpu_to_le32(GPT_PRIMARY_PARTITION_TABLE_LBA))
+		goto done;
+
+	/*
+	 * Protective MBRs take up the lesser of the whole disk
+	 * or 2 TiB (32bit LBA), ignoring the rest of the disk.
+	 * Some partitioning programs, nonetheless, choose to set
+	 * the size to the maximum 32-bit limitation, disregarding
+	 * the disk size.
+	 *
+	 * Hybrid MBRs do not necessarily comply with this.
+	 *
+	 * Consider a bad value here to be a warning to support dd-ing
+	 * an image from a smaller disk to a bigger disk.
+	 */
+	if (ret == GPT_MBR_PROTECTIVE) {
+		uint64_t sz_lba = (uint64_t) le32_to_cpu(pmbr->partition_record[part].size_in_lba);
+		if (sz_lba != cxt->total_sectors - 1ULL && sz_lba != 0xFFFFFFFFULL) {
+
+			fdisk_warnx(cxt, _("GPT PMBR size mismatch (%"PRIu64" != %"PRIu64") "
+					   "will be corrected by write."),
+					sz_lba, cxt->total_sectors - (uint64_t) 1);
+
+			/* Note that gpt_write_pmbr() overwrites PMBR, but we want to keep it valid already
+			 * in memory too to disable warnings when valid_pmbr() called next time */
+			pmbr->partition_record[part].size_in_lba  =
+				cpu_to_le32((uint32_t) min( cxt->total_sectors - 1ULL, 0xFFFFFFFFULL) );
+			fdisk_label_set_changed(cxt->label, 1);
+		}
+	}
+done:
+	DBG(GPT, ul_debug("PMBR type: %s",
+			ret == GPT_MBR_PROTECTIVE ? "protective" :
+			ret == GPT_MBR_HYBRID     ? "hybrid"     : "???" ));
+	return ret;
+}
+
+static uint64_t last_lba(struct fdisk_context *cxt)
+{
+	struct stat s;
+	uint64_t sectors = 0;
+
+	memset(&s, 0, sizeof(s));
+	if (fstat(cxt->dev_fd, &s) == -1) {
+		fdisk_warn(cxt, _("gpt: stat() failed"));
+		return 0;
+	}
+
+	if (S_ISBLK(s.st_mode))
+		sectors = cxt->total_sectors - 1ULL;
+	else if (S_ISREG(s.st_mode))
+		sectors = ((uint64_t) s.st_size /
+			   (uint64_t) cxt->sector_size) - 1ULL;
+	else
+		fdisk_warnx(cxt, _("gpt: cannot handle files with mode %o"), s.st_mode);
+
+	DBG(GPT, ul_debug("last LBA: %"PRIu64"", sectors));
+	return sectors;
+}
+
+static ssize_t read_lba(struct fdisk_context *cxt, uint64_t lba,
+			void *buffer, const size_t bytes)
+{
+	off_t offset = lba * cxt->sector_size;
+
+	if (lseek(cxt->dev_fd, offset, SEEK_SET) == (off_t) -1)
+		return -1;
+	return (size_t)read(cxt->dev_fd, buffer, bytes) != bytes;
+}
+
+
+/* Returns the GPT entry array */
+static unsigned char *gpt_read_entries(struct fdisk_context *cxt,
+					 struct gpt_header *header)
+{
+	size_t sz = 0;
+	ssize_t ssz;
+
+	unsigned char *ret = NULL;
+	off_t offset;
+
+	assert(cxt);
+	assert(header);
+
+	if (gpt_sizeof_entries(header, &sz))
+		return NULL;
+
+	if (sz > (size_t) SSIZE_MAX) {
+		DBG(GPT, ul_debug("entries array too large to read()"));
+		return NULL;
+	}
+
+	ret = calloc(1, sz);
+	if (!ret)
+		return NULL;
+
+	offset = (off_t) le64_to_cpu(header->partition_entry_lba) *
+		       cxt->sector_size;
+
+	if (offset != lseek(cxt->dev_fd, offset, SEEK_SET))
+		goto fail;
+
+	ssz = read(cxt->dev_fd, ret, sz);
+	if (ssz < 0 || (size_t) ssz != sz)
+		goto fail;
+
+	return ret;
+
+fail:
+	free(ret);
+	return NULL;
+}
+
+static inline uint32_t count_crc32(const unsigned char *buf, size_t len,
+				   size_t ex_off, size_t ex_len)
+{
+	return (ul_crc32_exclude_offset(~0L, buf, len, ex_off, ex_len) ^ ~0L);
+}
+
+static inline uint32_t gpt_header_count_crc32(struct gpt_header *header)
+{
+        return count_crc32((unsigned char *) header,		/* buffer */
+			le32_to_cpu(header->size),		/* size of buffer */
+			offsetof(struct gpt_header, crc32),	/* exclude */
+			sizeof(header->crc32));			/* size of excluded area */
+}
+
+static inline uint32_t gpt_entryarr_count_crc32(struct gpt_header *header, unsigned char *ents)
+{
+	size_t arysz = 0;
+
+	if (gpt_sizeof_entries(header, &arysz))
+		return 0;
+
+	return count_crc32(ents, arysz, 0, 0);
+}
+
+
+/*
+ * Recompute header and partition array 32bit CRC checksums.
+ * This function does not fail - if there's corruption, then it
+ * will be reported when checksumming it again (ie: probing or verify).
+ */
+static void gpt_recompute_crc(struct gpt_header *header, unsigned char *ents)
+{
+	if (!header)
+		return;
+
+	header->partition_entry_array_crc32 =
+			cpu_to_le32( gpt_entryarr_count_crc32(header, ents) );
+
+	header->crc32 = cpu_to_le32( gpt_header_count_crc32(header) );
+}
+
+/*
+ * Compute the 32bit CRC checksum of the partition table header.
+ * Returns 1 if it is valid, otherwise 0.
+ */
+static int gpt_check_header_crc(struct gpt_header *header, unsigned char *ents)
+{
+	uint32_t orgcrc = le32_to_cpu(header->crc32),
+		 crc = gpt_header_count_crc32(header);
+
+	if (crc == orgcrc)
+		return 1;
+
+	/*
+	 * If we have checksum mismatch it may be due to stale data, like a
+	 * partition being added or deleted. Recompute the CRC again and make
+	 * sure this is not the case.
+	 */
+	if (ents) {
+		gpt_recompute_crc(header, ents);
+		return gpt_header_count_crc32(header) == orgcrc;
+	}
+
+	return 0;
+}
+
+/*
+ * It initializes the partition entry array.
+ * Returns 1 if the checksum is valid, otherwise 0.
+ */
+static int gpt_check_entryarr_crc(struct gpt_header *header, unsigned char *ents)
+{
+	if (!header || !ents)
+		return 0;
+
+	return gpt_entryarr_count_crc32(header, ents) ==
+			le32_to_cpu(header->partition_entry_array_crc32);
+}
+
+static int gpt_check_lba_sanity(struct fdisk_context *cxt, struct gpt_header *header)
+{
+	int ret = 0;
+	uint64_t lu, fu, lastlba = last_lba(cxt);
+
+	fu = le64_to_cpu(header->first_usable_lba);
+	lu = le64_to_cpu(header->last_usable_lba);
+
+	/* check if first and last usable LBA make sense */
+	if (lu < fu) {
+		DBG(GPT, ul_debug("error: header last LBA is before first LBA"));
+		goto done;
+	}
+
+	/* check if first and last usable LBAs with the disk's last LBA */
+	if (fu > lastlba || lu > lastlba) {
+		DBG(GPT, ul_debug("error: header LBAs are after the disk's last LBA (%ju..%ju)",
+					(uintmax_t) fu, (uintmax_t) lu));
+		goto done;
+	}
+
+	/* the header has to be outside usable range */
+	if (fu < GPT_PRIMARY_PARTITION_TABLE_LBA &&
+	    GPT_PRIMARY_PARTITION_TABLE_LBA < lu) {
+		DBG(GPT, ul_debug("error: header outside of usable range"));
+		goto done;
+	}
+
+	ret = 1; /* sane */
+done:
+	return ret;
+}
+
+/* Check if there is a valid header signature */
+static int gpt_check_signature(struct gpt_header *header)
+{
+	return header->signature == cpu_to_le64(GPT_HEADER_SIGNATURE);
+}
+
+/*
+ * Return the specified GPT Header, or NULL upon failure/invalid.
+ * Note that all tests must pass to ensure a valid header,
+ * we do not rely on only testing the signature for a valid probe.
+ */
+static struct gpt_header *gpt_read_header(struct fdisk_context *cxt,
+					  uint64_t lba,
+					  unsigned char **_ents)
+{
+	struct gpt_header *header = NULL;
+	unsigned char *ents = NULL;
+	uint32_t hsz;
+
+	if (!cxt)
+		return NULL;
+
+	/* always allocate all sector, the area after GPT header
+	 * has to be fill by zeros */
+	assert(cxt->sector_size >= sizeof(struct gpt_header));
+
+	header = calloc(1, cxt->sector_size);
+	if (!header)
+		return NULL;
+
+	/* read and verify header */
+	if (read_lba(cxt, lba, header, cxt->sector_size) != 0)
+		goto invalid;
+
+	if (!gpt_check_signature(header))
+		goto invalid;
+
+	/* make sure header size is between 92 and sector size bytes */
+	hsz = le32_to_cpu(header->size);
+	if (hsz < GPT_HEADER_MINSZ || hsz > cxt->sector_size)
+		goto invalid;
+
+	if (!gpt_check_header_crc(header, NULL))
+		goto invalid;
+
+	/* read and verify entries */
+	ents = gpt_read_entries(cxt, header);
+	if (!ents)
+		goto invalid;
+
+	if (!gpt_check_entryarr_crc(header, ents))
+		goto invalid;
+
+	if (!gpt_check_lba_sanity(cxt, header))
+		goto invalid;
+
+	/* valid header must be at MyLBA */
+	if (le64_to_cpu(header->my_lba) != lba)
+		goto invalid;
+
+	if (_ents)
+		*_ents = ents;
+	else
+		free(ents);
+
+	DBG(GPT, ul_debug("found valid header on LBA %"PRIu64"", lba));
+	return header;
+invalid:
+	free(header);
+	free(ents);
+
+	DBG(GPT, ul_debug("read header on LBA %"PRIu64" failed", lba));
+	return NULL;
+}
+
+
+static int gpt_locate_disklabel(struct fdisk_context *cxt, int n,
+		const char **name, uint64_t *offset, size_t *size)
+{
+	struct fdisk_gpt_label *gpt;
+
+	assert(cxt);
+
+	*name = NULL;
+	*offset = 0;
+	*size = 0;
+
+	switch (n) {
+	case 0:
+		*name = "PMBR";
+		*offset = 0;
+		*size = 512;
+		break;
+	case 1:
+		*name = _("GPT Header");
+		*offset = (uint64_t) GPT_PRIMARY_PARTITION_TABLE_LBA * cxt->sector_size;
+		*size = sizeof(struct gpt_header);
+		break;
+	case 2:
+		*name = _("GPT Entries");
+		gpt = self_label(cxt);
+		*offset = (uint64_t) le64_to_cpu(gpt->pheader->partition_entry_lba) *
+				     cxt->sector_size;
+		return gpt_sizeof_entries(gpt->pheader, size);
+	case 3:
+		*name = _("GPT Backup Entries");
+		gpt = self_label(cxt);
+		*offset = (uint64_t) le64_to_cpu(gpt->bheader->partition_entry_lba) *
+				     cxt->sector_size;
+		return gpt_sizeof_entries(gpt->bheader, size);
+	case 4:
+		*name = _("GPT Backup Header");
+		gpt = self_label(cxt);
+		*offset = (uint64_t) le64_to_cpu(gpt->pheader->alternative_lba) * cxt->sector_size;
+		*size = sizeof(struct gpt_header);
+		break;
+	default:
+		return 1;			/* no more chunks */
+	}
+
+	return 0;
+}
+
+static int gpt_get_disklabel_item(struct fdisk_context *cxt, struct fdisk_labelitem *item)
+{
+	struct gpt_header *h;
+	int rc = 0;
+	uint64_t x = 0;
+
+	assert(cxt);
+	assert(cxt->label);
+	assert(fdisk_is_label(cxt, GPT));
+
+	h = self_label(cxt)->pheader;
+
+	switch (item->id) {
+	case GPT_LABELITEM_ID:
+		item->name = _("Disk identifier");
+		item->type = 's';
+		item->data.str = gpt_get_header_id(h);
+		if (!item->data.str)
+			rc = -ENOMEM;
+		break;
+	case GPT_LABELITEM_FIRSTLBA:
+		item->name = _("First usable LBA");
+		item->type = 'j';
+		item->data.num64 = le64_to_cpu(h->first_usable_lba);
+		break;
+	case GPT_LABELITEM_LASTLBA:
+		item->name = _("Last usable LBA");
+		item->type = 'j';
+		item->data.num64 = le64_to_cpu(h->last_usable_lba);
+		break;
+	case GPT_LABELITEM_ALTLBA:
+		/* TRANSLATORS: The LBA (Logical Block Address) of the backup GPT header. */
+		item->name = _("Alternative LBA");
+		item->type = 'j';
+		item->data.num64 = le64_to_cpu(h->alternative_lba);
+		break;
+	case GPT_LABELITEM_ENTRIESLBA:
+		/* TRANSLATORS: The start of the array of partition entries. */
+		item->name = _("Partition entries starting LBA");
+		item->type = 'j';
+		item->data.num64 = le64_to_cpu(h->partition_entry_lba);
+		break;
+	case GPT_LABELITEM_ENTRIESLASTLBA:
+		/* TRANSLATORS: The end of the array of partition entries. */
+		item->name = _("Partition entries ending LBA");
+		item->type = 'j';
+		gpt_calculate_sectorsof_entries(h,
+				le32_to_cpu(h->npartition_entries), &x, cxt);
+		item->data.num64 = le64_to_cpu(h->partition_entry_lba) + x - 1;
+		break;
+	case GPT_LABELITEM_ENTRIESALLOC:
+		item->name = _("Allocated partition entries");
+		item->type = 'j';
+		item->data.num64 = le32_to_cpu(h->npartition_entries);
+		break;
+	default:
+		if (item->id < __FDISK_NLABELITEMS)
+			rc = 1;	/* unsupported generic item */
+		else
+			rc = 2;	/* out of range */
+		break;
+	}
+
+	return rc;
+}
+
+/*
+ * Returns the number of partitions that are in use.
+ */
+static size_t partitions_in_use(struct fdisk_gpt_label *gpt)
+{
+	size_t i, used = 0;
+
+	assert(gpt);
+	assert(gpt->pheader);
+	assert(gpt->ents);
+
+	for (i = 0; i < gpt_get_nentries(gpt); i++) {
+		struct gpt_entry *e = gpt_get_entry(gpt, i);
+
+		if (gpt_entry_is_used(e))
+			used++;
+	}
+	return used;
+}
+
+
+/*
+ * Check if a partition is too big for the disk (sectors).
+ * Returns the faulting partition number, otherwise 0.
+ */
+static uint32_t check_too_big_partitions(struct fdisk_gpt_label *gpt, uint64_t sectors)
+{
+	size_t i;
+
+	assert(gpt);
+	assert(gpt->pheader);
+	assert(gpt->ents);
+
+	for (i = 0; i < gpt_get_nentries(gpt); i++) {
+		struct gpt_entry *e = gpt_get_entry(gpt, i);
+
+		if (!gpt_entry_is_used(e))
+			continue;
+		if (gpt_partition_end(e) >= sectors)
+			return i + 1;
+	}
+
+	return 0;
+}
+
+/*
+ * Check if a partition ends before it begins
+ * Returns the faulting partition number, otherwise 0.
+ */
+static uint32_t check_start_after_end_partitions(struct fdisk_gpt_label *gpt)
+{
+	size_t i;
+
+	assert(gpt);
+	assert(gpt->pheader);
+	assert(gpt->ents);
+
+	for (i = 0; i < gpt_get_nentries(gpt); i++) {
+		struct gpt_entry *e = gpt_get_entry(gpt, i);
+
+		if (!gpt_entry_is_used(e))
+			continue;
+		if (gpt_partition_start(e) > gpt_partition_end(e))
+			return i + 1;
+	}
+
+	return 0;
+}
+
+/*
+ * Check if partition e1 overlaps with partition e2.
+ */
+static inline int partition_overlap(struct gpt_entry *e1, struct gpt_entry *e2)
+{
+	uint64_t start1 = gpt_partition_start(e1);
+	uint64_t end1   = gpt_partition_end(e1);
+	uint64_t start2 = gpt_partition_start(e2);
+	uint64_t end2   = gpt_partition_end(e2);
+
+	return (start1 && start2 && (start1 <= end2) != (end1 < start2));
+}
+
+/*
+ * Find any partitions that overlap.
+ */
+static uint32_t check_overlap_partitions(struct fdisk_gpt_label *gpt)
+{
+	size_t i, j;
+
+	assert(gpt);
+	assert(gpt->pheader);
+	assert(gpt->ents);
+
+	for (i = 0; i < gpt_get_nentries(gpt); i++)
+		for (j = 0; j < i; j++) {
+			struct gpt_entry *ei = gpt_get_entry(gpt, i);
+			struct gpt_entry *ej = gpt_get_entry(gpt, j);
+
+			if (!gpt_entry_is_used(ei) || !gpt_entry_is_used(ej))
+				continue;
+			if (partition_overlap(ei, ej)) {
+				DBG(GPT, ul_debug("partitions overlap detected [%zu vs. %zu]", i, j));
+				return i + 1;
+			}
+		}
+
+	return 0;
+}
+
+/*
+ * Find the first available block after the starting point; returns 0 if
+ * there are no available blocks left, or error. From gdisk.
+ */
+static uint64_t find_first_available(struct fdisk_gpt_label *gpt, uint64_t start)
+{
+	int first_moved = 0;
+	uint64_t first;
+	uint64_t fu, lu;
+
+	assert(gpt);
+	assert(gpt->pheader);
+	assert(gpt->ents);
+
+	fu = le64_to_cpu(gpt->pheader->first_usable_lba);
+	lu = le64_to_cpu(gpt->pheader->last_usable_lba);
+
+	/*
+	 * Begin from the specified starting point or from the first usable
+	 * LBA, whichever is greater...
+	 */
+	first = start < fu ? fu : start;
+
+	/*
+	 * Now search through all partitions; if first is within an
+	 * existing partition, move it to the next sector after that
+	 * partition and repeat. If first was moved, set firstMoved
+	 * flag; repeat until firstMoved is not set, so as to catch
+	 * cases where partitions are out of sequential order....
+	 */
+	do {
+		size_t i;
+
+		first_moved = 0;
+		for (i = 0; i < gpt_get_nentries(gpt); i++) {
+			struct gpt_entry *e = gpt_get_entry(gpt, i);
+
+			if (!gpt_entry_is_used(e))
+				continue;
+			if (first < gpt_partition_start(e))
+				continue;
+			if (first <= gpt_partition_end(e)) {
+				first = gpt_partition_end(e) + 1;
+				first_moved = 1;
+			}
+		}
+	} while (first_moved == 1);
+
+	if (first > lu)
+		first = 0;
+
+	return first;
+}
+
+
+/* Returns last available sector in the free space pointed to by start. From gdisk. */
+static uint64_t find_last_free(struct fdisk_gpt_label *gpt, uint64_t start)
+{
+	size_t i;
+	uint64_t nearest_start;
+
+	assert(gpt);
+	assert(gpt->pheader);
+	assert(gpt->ents);
+
+	nearest_start = le64_to_cpu(gpt->pheader->last_usable_lba);
+
+	for (i = 0; i < gpt_get_nentries(gpt); i++) {
+		struct gpt_entry *e = gpt_get_entry(gpt, i);
+		uint64_t ps = gpt_partition_start(e);
+
+		if (nearest_start > ps && ps > start)
+			nearest_start = ps - 1ULL;
+	}
+
+	return nearest_start;
+}
+
+/* Returns the last free sector on the disk. From gdisk. */
+static uint64_t find_last_free_sector(struct fdisk_gpt_label *gpt)
+{
+	int last_moved;
+	uint64_t last = 0;
+
+	assert(gpt);
+	assert(gpt->pheader);
+	assert(gpt->ents);
+
+	/* start by assuming the last usable LBA is available */
+	last = le64_to_cpu(gpt->pheader->last_usable_lba);
+	do {
+		size_t i;
+
+		last_moved = 0;
+		for (i = 0; i < gpt_get_nentries(gpt); i++) {
+			struct gpt_entry *e = gpt_get_entry(gpt, i);
+
+			if (last >= gpt_partition_start(e) &&
+			    last <= gpt_partition_end(e)) {
+				last = gpt_partition_start(e) - 1ULL;
+				last_moved = 1;
+			}
+		}
+	} while (last_moved == 1);
+
+	return last;
+}
+
+/*
+ * Finds the first available sector in the largest block of unallocated
+ * space on the disk. Returns 0 if there are no available blocks left.
+ * From gdisk.
+ */
+static uint64_t find_first_in_largest(struct fdisk_gpt_label *gpt)
+{
+	uint64_t start = 0, first_sect, last_sect;
+	uint64_t segment_size, selected_size = 0, selected_segment = 0;
+
+	assert(gpt);
+	assert(gpt->pheader);
+	assert(gpt->ents);
+
+	do {
+		first_sect = find_first_available(gpt, start);
+		if (first_sect != 0) {
+			last_sect = find_last_free(gpt, first_sect);
+			segment_size = last_sect - first_sect + 1ULL;
+
+			if (segment_size > selected_size) {
+				selected_size = segment_size;
+				selected_segment = first_sect;
+			}
+			start = last_sect + 1ULL;
+		}
+	} while (first_sect != 0);
+
+	return selected_segment;
+}
+
+/*
+ * Find the total number of free sectors, the number of segments in which
+ * they reside, and the size of the largest of those segments. From gdisk.
+ */
+static uint64_t get_free_sectors(struct fdisk_context *cxt,
+				 struct fdisk_gpt_label *gpt,
+				 uint32_t *nsegments,
+				 uint64_t *largest_segment)
+{
+	uint32_t num = 0;
+	uint64_t first_sect, last_sect;
+	uint64_t largest_seg = 0, segment_sz;
+	uint64_t totfound = 0, start = 0; /* starting point for each search */
+
+	if (!cxt->total_sectors)
+		goto done;
+
+	assert(gpt);
+	assert(gpt->pheader);
+	assert(gpt->ents);
+
+	do {
+		first_sect = find_first_available(gpt, start);
+		if (first_sect) {
+			last_sect = find_last_free(gpt, first_sect);
+			segment_sz = last_sect - first_sect + 1;
+
+			if (segment_sz > largest_seg)
+				largest_seg = segment_sz;
+			totfound += segment_sz;
+			num++;
+			start = last_sect + 1ULL;
+		}
+	} while (first_sect);
+
+done:
+	if (nsegments)
+		*nsegments = num;
+	if (largest_segment)
+		*largest_segment = largest_seg;
+
+	return totfound;
+}
+
+static int gpt_probe_label(struct fdisk_context *cxt)
+{
+	int mbr_type;
+	struct fdisk_gpt_label *gpt;
+
+	assert(cxt);
+	assert(cxt->label);
+	assert(fdisk_is_label(cxt, GPT));
+
+	gpt = self_label(cxt);
+
+	/* TODO: it would be nice to support scenario when GPT headers are OK,
+	 *       but PMBR is corrupt */
+	mbr_type = valid_pmbr(cxt);
+	if (!mbr_type)
+		goto failed;
+
+	/* primary header */
+	gpt->pheader = gpt_read_header(cxt, GPT_PRIMARY_PARTITION_TABLE_LBA,
+				       &gpt->ents);
+
+	if (gpt->pheader)
+		/* primary OK, try backup from alternative LBA */
+		gpt->bheader = gpt_read_header(cxt,
+					le64_to_cpu(gpt->pheader->alternative_lba),
+					NULL);
+	else
+		/* primary corrupted -- try last LBA */
+		gpt->bheader = gpt_read_header(cxt, last_lba(cxt), &gpt->ents);
+
+	if (!gpt->pheader && !gpt->bheader)
+		goto failed;
+
+	/* primary OK, backup corrupted -- recovery */
+	if (gpt->pheader && !gpt->bheader) {
+		fdisk_warnx(cxt, _("The backup GPT table is corrupt, but the "
+				  "primary appears OK, so that will be used."));
+		gpt->bheader = gpt_copy_header(cxt, gpt->pheader);
+		if (!gpt->bheader)
+			goto failed;
+		gpt_recompute_crc(gpt->bheader, gpt->ents);
+		fdisk_label_set_changed(cxt->label, 1);
+
+	/* primary corrupted, backup OK -- recovery */
+	} else if (!gpt->pheader && gpt->bheader) {
+		fdisk_warnx(cxt, _("The primary GPT table is corrupt, but the "
+				  "backup appears OK, so that will be used."));
+		gpt->pheader = gpt_copy_header(cxt, gpt->bheader);
+		if (!gpt->pheader)
+			goto failed;
+		gpt_recompute_crc(gpt->pheader, gpt->ents);
+		fdisk_label_set_changed(cxt->label, 1);
+	}
+
+	/* The headers make be correct, but Backup do not have to be on the end
+	 * of the device (due to device resize, etc.). Let's fix this issue. */
+	if (gpt->minimize == 0 &&
+	    (le64_to_cpu(gpt->pheader->alternative_lba) > cxt->total_sectors ||
+	     le64_to_cpu(gpt->pheader->alternative_lba) < cxt->total_sectors - 1ULL)) {
+
+		if (gpt->no_relocate || fdisk_is_readonly(cxt))
+			fdisk_warnx(cxt, _("The backup GPT table is not on the end of the device."));
+
+		else {
+			fdisk_warnx(cxt, _("The backup GPT table is not on the end of the device. "
+					   "This problem will be corrected by write."));
+
+			if (gpt_fix_alternative_lba(cxt, gpt) != 0)
+				fdisk_warnx(cxt, _("Failed to recalculate backup GPT table location"));
+			gpt_recompute_crc(gpt->bheader, gpt->ents);
+			gpt_recompute_crc(gpt->pheader, gpt->ents);
+			fdisk_label_set_changed(cxt->label, 1);
+		}
+	}
+
+	if (gpt->minimize && gpt_possible_minimize(cxt, gpt))
+		fdisk_label_set_changed(cxt->label, 1);
+
+	cxt->label->nparts_max = gpt_get_nentries(gpt);
+	cxt->label->nparts_cur = partitions_in_use(gpt);
+	return 1;
+failed:
+	DBG(GPT, ul_debug("probe failed"));
+	gpt_deinit(cxt->label);
+	return 0;
+}
+
+static char *encode_to_utf8(unsigned char *src, size_t count)
+{
+	unsigned char *dest;
+	size_t len = (count * 3 / 2) + 1;
+
+	dest = calloc(1, len);
+	if (!dest)
+		return NULL;
+
+	ul_encode_to_utf8(UL_ENCODE_UTF16LE, dest, len, src, count);
+	return (char *) dest;
+}
+
+static int gpt_entry_attrs_to_string(struct gpt_entry *e, char **res)
+{
+	unsigned int n, count = 0;
+	size_t l;
+	char *bits, *p;
+	uint64_t attrs;
+
+	assert(e);
+	assert(res);
+
+	*res = NULL;
+	attrs = e->attrs;
+	if (!attrs)
+		return 0;	/* no attributes at all */
+
+	bits = (char *) &attrs;
+
+	/* Note that sizeof() is correct here, we need separators between
+	 * the strings so also count \0 is correct */
+	*res = calloc(1, sizeof(GPT_ATTRSTR_NOBLOCK) +
+			 sizeof(GPT_ATTRSTR_REQ) +
+			 sizeof(GPT_ATTRSTR_LEGACY) +
+			 sizeof("GUID:") + (GPT_ATTRBIT_GUID_COUNT * 3));
+	if (!*res)
+		return -errno;
+
+	p = *res;
+	if (isset(bits, GPT_ATTRBIT_REQ)) {
+		memcpy(p, GPT_ATTRSTR_REQ, (l = sizeof(GPT_ATTRSTR_REQ)));
+		p += l - 1;
+	}
+	if (isset(bits, GPT_ATTRBIT_NOBLOCK)) {
+		if (p != *res)
+			*p++ = ' ';
+		memcpy(p, GPT_ATTRSTR_NOBLOCK, (l = sizeof(GPT_ATTRSTR_NOBLOCK)));
+		p += l - 1;
+	}
+	if (isset(bits, GPT_ATTRBIT_LEGACY)) {
+		if (p != *res)
+			*p++ = ' ';
+		memcpy(p, GPT_ATTRSTR_LEGACY, (l = sizeof(GPT_ATTRSTR_LEGACY)));
+		p += l - 1;
+	}
+
+	for (n = GPT_ATTRBIT_GUID_FIRST;
+	     n < GPT_ATTRBIT_GUID_FIRST + GPT_ATTRBIT_GUID_COUNT; n++) {
+
+		if (!isset(bits, n))
+			continue;
+		if (!count) {
+			if (p != *res)
+				*p++ = ' ';
+			p += sprintf(p, "GUID:%u", n);
+		} else
+			p += sprintf(p, ",%u", n);
+		count++;
+	}
+
+	return 0;
+}
+
+static int gpt_entry_attrs_from_string(
+			struct fdisk_context *cxt,
+			struct gpt_entry *e,
+			const char *str)
+{
+	const char *p = str;
+	uint64_t attrs = 0;
+	char *bits;
+
+	assert(e);
+	assert(p);
+
+	DBG(GPT, ul_debug("parsing string attributes '%s'", p));
+
+	bits = (char *) &attrs;
+
+	while (p && *p) {
+		int bit = -1;
+
+		while (isblank(*p)) p++;
+		if (!*p)
+			break;
+
+		DBG(GPT, ul_debug(" item '%s'", p));
+
+		if (strncmp(p, GPT_ATTRSTR_REQ,
+					sizeof(GPT_ATTRSTR_REQ) - 1) == 0) {
+			bit = GPT_ATTRBIT_REQ;
+			p += sizeof(GPT_ATTRSTR_REQ) - 1;
+		} else if (strncmp(p, GPT_ATTRSTR_REQ_TYPO,
+					sizeof(GPT_ATTRSTR_REQ_TYPO) - 1) == 0) {
+			bit = GPT_ATTRBIT_REQ;
+			p += sizeof(GPT_ATTRSTR_REQ_TYPO) - 1;
+		} else if (strncmp(p, GPT_ATTRSTR_LEGACY,
+					sizeof(GPT_ATTRSTR_LEGACY) - 1) == 0) {
+			bit = GPT_ATTRBIT_LEGACY;
+			p += sizeof(GPT_ATTRSTR_LEGACY) - 1;
+		} else if (strncmp(p, GPT_ATTRSTR_NOBLOCK,
+					sizeof(GPT_ATTRSTR_NOBLOCK) - 1) == 0) {
+			bit = GPT_ATTRBIT_NOBLOCK;
+			p += sizeof(GPT_ATTRSTR_NOBLOCK) - 1;
+
+		/* GUID:<bit> as well as <bit> */
+		} else if (isdigit((unsigned char) *p)
+			   || (strncmp(p, "GUID:", 5) == 0
+			       && isdigit((unsigned char) *(p + 5)))) {
+			char *end = NULL;
+
+			if (*p == 'G')
+				p += 5;
+
+			errno = 0;
+			bit = strtol(p, &end, 0);
+			if (errno || !end || end == str
+			    || bit < GPT_ATTRBIT_GUID_FIRST
+			    || bit >= GPT_ATTRBIT_GUID_FIRST + GPT_ATTRBIT_GUID_COUNT)
+				bit = -1;
+			else
+				p = end;
+		}
+
+		if (bit < 0) {
+			fdisk_warnx(cxt, _("unsupported GPT attribute bit '%s'"), p);
+			return -EINVAL;
+		}
+
+		if (*p && *p != ',' && !isblank(*p)) {
+			fdisk_warnx(cxt, _("failed to parse GPT attribute string '%s'"), str);
+			return -EINVAL;
+		}
+
+		setbit(bits, bit);
+
+		while (isblank(*p)) p++;
+		if (*p == ',')
+			p++;
+	}
+
+	e->attrs = attrs;
+	return 0;
+}
+
+static int gpt_get_partition(struct fdisk_context *cxt, size_t n,
+			     struct fdisk_partition *pa)
+{
+	struct fdisk_gpt_label *gpt;
+	struct gpt_entry *e;
+	char u_str[UUID_STR_LEN];
+	int rc = 0;
+	struct gpt_guid guid;
+
+	assert(cxt);
+	assert(cxt->label);
+	assert(fdisk_is_label(cxt, GPT));
+
+	gpt = self_label(cxt);
+
+	if (n >= gpt_get_nentries(gpt))
+		return -EINVAL;
+
+	gpt = self_label(cxt);
+	e = gpt_get_entry(gpt, n);
+
+	pa->used = gpt_entry_is_used(e) || gpt_partition_start(e);
+	if (!pa->used)
+		return 0;
+
+	pa->start = gpt_partition_start(e);
+	pa->size = gpt_partition_size(e);
+	pa->type = gpt_partition_parttype(cxt, e);
+
+	guid = e->partition_guid;
+	if (guid_to_string(&guid, u_str)) {
+		pa->uuid = strdup(u_str);
+		if (!pa->uuid) {
+			rc = -errno;
+			goto done;
+		}
+	} else
+		pa->uuid = NULL;
+
+	rc = gpt_entry_attrs_to_string(e, &pa->attrs);
+	if (rc)
+		goto done;
+
+	pa->name = encode_to_utf8((unsigned char *)e->name, sizeof(e->name));
+	return 0;
+done:
+	fdisk_reset_partition(pa);
+	return rc;
+}
+
+
+static int gpt_set_partition(struct fdisk_context *cxt, size_t n,
+			     struct fdisk_partition *pa)
+{
+	struct fdisk_gpt_label *gpt;
+	struct gpt_entry *e;
+	int rc = 0;
+	uint64_t start, end;
+
+	assert(cxt);
+	assert(cxt->label);
+	assert(fdisk_is_label(cxt, GPT));
+
+	gpt = self_label(cxt);
+
+	if (n >= gpt_get_nentries(gpt))
+		return -EINVAL;
+
+	FDISK_INIT_UNDEF(start);
+	FDISK_INIT_UNDEF(end);
+
+	gpt = self_label(cxt);
+	e = gpt_get_entry(gpt, n);
+
+	if (pa->uuid) {
+		char new_u[UUID_STR_LEN], old_u[UUID_STR_LEN];
+		struct gpt_guid guid;
+
+		guid = e->partition_guid;
+		guid_to_string(&guid, old_u);
+		rc = gpt_entry_set_uuid(e, pa->uuid);
+		if (rc)
+			return rc;
+		guid = e->partition_guid;
+		guid_to_string(&guid, new_u);
+		fdisk_info(cxt, _("Partition UUID changed from %s to %s."),
+			old_u, new_u);
+	}
+
+	if (pa->name) {
+		int len;
+		char *old = encode_to_utf8((unsigned char *)e->name, sizeof(e->name));
+		len = gpt_entry_set_name(e, pa->name);
+		if (len < 0)
+			fdisk_warn(cxt, _("Failed to translate partition name, name not changed."));
+		else
+			fdisk_info(cxt, _("Partition name changed from '%s' to '%.*s'."),
+				old, len, pa->name);
+		free(old);
+	}
+
+	if (pa->type && pa->type->typestr) {
+		struct gpt_guid typeid;
+
+		rc = string_to_guid(pa->type->typestr, &typeid);
+		if (rc)
+			return rc;
+		gpt_entry_set_type(e, &typeid);
+	}
+	if (pa->attrs) {
+		rc = gpt_entry_attrs_from_string(cxt, e, pa->attrs);
+		if (rc)
+			return rc;
+	}
+
+	if (fdisk_partition_has_start(pa))
+		start = pa->start;
+	if (fdisk_partition_has_size(pa) || fdisk_partition_has_start(pa)) {
+		uint64_t xstart = fdisk_partition_has_start(pa) ? pa->start : gpt_partition_start(e);
+		uint64_t xsize  = fdisk_partition_has_size(pa)  ? pa->size  : gpt_partition_size(e);
+		end = xstart + xsize - 1ULL;
+	}
+
+	if (!FDISK_IS_UNDEF(start)) {
+		if (start < le64_to_cpu(gpt->pheader->first_usable_lba)) {
+			fdisk_warnx(cxt, _("The start of the partition understeps FirstUsableLBA."));
+			return -EINVAL;
+		}
+		e->lba_start = cpu_to_le64(start);
+	}
+	if (!FDISK_IS_UNDEF(end)) {
+		if (end > le64_to_cpu(gpt->pheader->last_usable_lba)) {
+			fdisk_warnx(cxt, _("The end of the partition oversteps LastUsableLBA."));
+			return -EINVAL;
+		}
+		e->lba_end = cpu_to_le64(end);
+	}
+	gpt_recompute_crc(gpt->pheader, gpt->ents);
+	gpt_recompute_crc(gpt->bheader, gpt->ents);
+
+	fdisk_label_set_changed(cxt->label, 1);
+	return rc;
+}
+
+static int gpt_write(struct fdisk_context *cxt, off_t offset, void *buf, size_t count)
+{
+	if (offset != lseek(cxt->dev_fd, offset, SEEK_SET))
+		return -errno;
+
+	if (write_all(cxt->dev_fd, buf, count))
+		return -errno;
+
+	fsync(cxt->dev_fd);
+
+	DBG(GPT, ul_debug("  write OK [offset=%zu, size=%zu]",
+				(size_t) offset, count));
+	return 0;
+}
+
+/*
+ * Write partitions.
+ * Returns 0 on success, or corresponding error otherwise.
+ */
+static int gpt_write_partitions(struct fdisk_context *cxt,
+				struct gpt_header *header, unsigned char *ents)
+{
+	size_t esz = 0;
+	int rc;
+
+	rc = gpt_sizeof_entries(header, &esz);
+	if (rc)
+		return rc;
+
+	return gpt_write(cxt,
+			(off_t) le64_to_cpu(header->partition_entry_lba) * cxt->sector_size,
+			ents, esz);
+}
+
+/*
+ * Write a GPT header to a specified LBA.
+ *
+ * We read all sector, so we have to write all sector back
+ * to the device -- never ever rely on sizeof(struct gpt_header)!
+ *
+ * Returns 0 on success, or corresponding error otherwise.
+ */
+static int gpt_write_header(struct fdisk_context *cxt,
+			    struct gpt_header *header, uint64_t lba)
+{
+	return gpt_write(cxt, lba * cxt->sector_size, header, cxt->sector_size);
+}
+
+/*
+ * Write the protective MBR.
+ * Returns 0 on success, or corresponding error otherwise.
+ */
+static int gpt_write_pmbr(struct fdisk_context *cxt)
+{
+	struct gpt_legacy_mbr *pmbr;
+
+	assert(cxt);
+	assert(cxt->firstsector);
+
+	DBG(GPT, ul_debug("(over)writing PMBR"));
+	pmbr = (struct gpt_legacy_mbr *) cxt->firstsector;
+
+	/* zero out the legacy partitions */
+	memset(pmbr->partition_record, 0, sizeof(pmbr->partition_record));
+
+	pmbr->signature = cpu_to_le16(MSDOS_MBR_SIGNATURE);
+	pmbr->partition_record[0].os_type      = EFI_PMBR_OSTYPE;
+	pmbr->partition_record[0].start_sector = 2;
+	pmbr->partition_record[0].end_head     = 0xFF;
+	pmbr->partition_record[0].end_sector   = 0xFF;
+	pmbr->partition_record[0].end_track    = 0xFF;
+	pmbr->partition_record[0].starting_lba = cpu_to_le32(1);
+
+	/*
+	 * Set size_in_lba to the size of the disk minus one. If the size of the disk
+	 * is too large to be represented by a 32bit LBA (2Tb), set it to 0xFFFFFFFF.
+	 */
+	if (cxt->total_sectors - 1ULL > 0xFFFFFFFFULL)
+		pmbr->partition_record[0].size_in_lba = cpu_to_le32(0xFFFFFFFF);
+	else
+		pmbr->partition_record[0].size_in_lba =
+			cpu_to_le32((uint32_t) (cxt->total_sectors - 1ULL));
+
+	/* pMBR covers the first sector (LBA) of the disk */
+	return gpt_write(cxt, GPT_PMBR_LBA * cxt->sector_size,
+			 pmbr, cxt->sector_size);
+}
+
+/*
+ * Writes in-memory GPT and pMBR data to disk.
+ * Returns 0 if successful write, otherwise, a corresponding error.
+ * Any indication of error will abort the operation.
+ */
+static int gpt_write_disklabel(struct fdisk_context *cxt)
+{
+	struct fdisk_gpt_label *gpt;
+	int mbr_type;
+
+	assert(cxt);
+	assert(cxt->label);
+	assert(fdisk_is_label(cxt, GPT));
+
+	DBG(GPT, ul_debug("writing..."));
+
+	gpt = self_label(cxt);
+	mbr_type = valid_pmbr(cxt);
+
+	/* check that disk is big enough to handle the backup header */
+	if (le64_to_cpu(gpt->pheader->alternative_lba) > cxt->total_sectors)
+		goto err0;
+
+	/* check that the backup header is properly placed */
+	if (le64_to_cpu(gpt->pheader->alternative_lba) < cxt->total_sectors - 1ULL)
+		goto err0;
+
+	if (check_overlap_partitions(gpt))
+		goto err0;
+
+	if (gpt->minimize)
+		gpt_minimize_alternative_lba(cxt, gpt);
+
+	/* recompute CRCs for both headers */
+	gpt_recompute_crc(gpt->pheader, gpt->ents);
+	gpt_recompute_crc(gpt->bheader, gpt->ents);
+
+	/*
+	 * UEFI requires writing in this specific order:
+	 *   1) backup partition tables
+	 *   2) backup GPT header
+	 *   3) primary partition tables
+	 *   4) primary GPT header
+	 *   5) protective MBR
+	 *
+	 * If any write fails, we abort the rest.
+	 */
+	if (gpt_write_partitions(cxt, gpt->bheader, gpt->ents) != 0)
+		goto err1;
+	if (gpt_write_header(cxt, gpt->bheader,
+			     le64_to_cpu(gpt->pheader->alternative_lba)) != 0)
+		goto err1;
+	if (gpt_write_partitions(cxt, gpt->pheader, gpt->ents) != 0)
+		goto err1;
+	if (gpt_write_header(cxt, gpt->pheader, GPT_PRIMARY_PARTITION_TABLE_LBA) != 0)
+		goto err1;
+
+	if (mbr_type == GPT_MBR_HYBRID)
+		fdisk_warnx(cxt, _("The device contains hybrid MBR -- writing GPT only."));
+	else if (gpt_write_pmbr(cxt) != 0)
+		goto err1;
+
+	DBG(GPT, ul_debug("...write success"));
+	return 0;
+err0:
+	DBG(GPT, ul_debug("...write failed: incorrect input"));
+	errno = EINVAL;
+	return -EINVAL;
+err1:
+	DBG(GPT, ul_debug("...write failed: %m"));
+	return -errno;
+}
+
+/*
+ * Verify data integrity and report any found problems for:
+ *   - primary and backup header validations
+ *   - partition validations
+ */
+static int gpt_verify_disklabel(struct fdisk_context *cxt)
+{
+	int nerror = 0;
+	unsigned int ptnum;
+	struct fdisk_gpt_label *gpt;
+
+	assert(cxt);
+	assert(cxt->label);
+	assert(fdisk_is_label(cxt, GPT));
+
+	gpt = self_label(cxt);
+	if (!gpt)
+		return -EINVAL;
+
+	if (!gpt->bheader) {
+		nerror++;
+		fdisk_warnx(cxt, _("Disk does not contain a valid backup header."));
+	}
+
+	if (!gpt_check_header_crc(gpt->pheader, gpt->ents)) {
+		nerror++;
+		fdisk_warnx(cxt, _("Invalid primary header CRC checksum."));
+	}
+	if (gpt->bheader && !gpt_check_header_crc(gpt->bheader, gpt->ents)) {
+		nerror++;
+		fdisk_warnx(cxt, _("Invalid backup header CRC checksum."));
+	}
+
+	if (!gpt_check_entryarr_crc(gpt->pheader, gpt->ents)) {
+		nerror++;
+		fdisk_warnx(cxt, _("Invalid partition entry checksum."));
+	}
+
+	if (!gpt_check_lba_sanity(cxt, gpt->pheader)) {
+		nerror++;
+		fdisk_warnx(cxt, _("Invalid primary header LBA sanity checks."));
+	}
+	if (gpt->bheader && !gpt_check_lba_sanity(cxt, gpt->bheader)) {
+		nerror++;
+		fdisk_warnx(cxt, _("Invalid backup header LBA sanity checks."));
+	}
+
+	if (le64_to_cpu(gpt->pheader->my_lba) != GPT_PRIMARY_PARTITION_TABLE_LBA) {
+		nerror++;
+		fdisk_warnx(cxt, _("MyLBA mismatch with real position at primary header."));
+	}
+	if (gpt->bheader && le64_to_cpu(gpt->bheader->my_lba) != last_lba(cxt)) {
+		nerror++;
+		fdisk_warnx(cxt, _("MyLBA mismatch with real position at backup header."));
+
+	}
+	if (le64_to_cpu(gpt->pheader->alternative_lba) >= cxt->total_sectors) {
+		nerror++;
+		fdisk_warnx(cxt, _("Disk is too small to hold all data."));
+	}
+
+	/*
+	 * if the GPT is the primary table, check the alternateLBA
+	 * to see if it is a valid GPT
+	 */
+	if (gpt->bheader && (le64_to_cpu(gpt->pheader->my_lba) !=
+			     le64_to_cpu(gpt->bheader->alternative_lba))) {
+		nerror++;
+		fdisk_warnx(cxt, _("Primary and backup header mismatch."));
+	}
+
+	ptnum = check_overlap_partitions(gpt);
+	if (ptnum) {
+		nerror++;
+		fdisk_warnx(cxt, _("Partition %u overlaps with partition %u."),
+				ptnum, ptnum+1);
+	}
+
+	ptnum = check_too_big_partitions(gpt, cxt->total_sectors);
+	if (ptnum) {
+		nerror++;
+		fdisk_warnx(cxt, _("Partition %u is too big for the disk."),
+				ptnum);
+	}
+
+	ptnum = check_start_after_end_partitions(gpt);
+	if (ptnum) {
+		nerror++;
+		fdisk_warnx(cxt, _("Partition %u ends before it starts."),
+				ptnum);
+	}
+
+	if (!nerror) { /* yay :-) */
+		uint32_t nsegments = 0;
+		uint64_t free_sectors = 0, largest_segment = 0;
+		char *strsz = NULL;
+
+		fdisk_info(cxt, _("No errors detected."));
+		fdisk_info(cxt, _("Header version: %s"), gpt_get_header_revstr(gpt->pheader));
+		fdisk_info(cxt, _("Using %zu out of %zu partitions."),
+		       partitions_in_use(gpt),
+		       gpt_get_nentries(gpt));
+
+		free_sectors = get_free_sectors(cxt, gpt, &nsegments, &largest_segment);
+		if (largest_segment)
+			strsz = size_to_human_string(SIZE_SUFFIX_SPACE | SIZE_SUFFIX_3LETTER,
+					largest_segment * cxt->sector_size);
+
+		fdisk_info(cxt,
+			   P_("A total of %ju free sectors is available in %u segment.",
+			      "A total of %ju free sectors is available in %u segments "
+			      "(the largest is %s).", nsegments),
+			   free_sectors, nsegments, strsz ? : "0 B");
+		free(strsz);
+
+	} else
+		fdisk_warnx(cxt,
+			P_("%d error detected.", "%d errors detected.", nerror),
+			nerror);
+
+	return nerror;
+}
+
+/* Delete a single GPT partition, specified by partnum. */
+static int gpt_delete_partition(struct fdisk_context *cxt,
+				size_t partnum)
+{
+	struct fdisk_gpt_label *gpt;
+
+	assert(cxt);
+	assert(cxt->label);
+	assert(fdisk_is_label(cxt, GPT));
+
+	gpt = self_label(cxt);
+
+	if (partnum >= cxt->label->nparts_max)
+		return -EINVAL;
+
+	if (!gpt_entry_is_used(gpt_get_entry(gpt, partnum)))
+		return -EINVAL;
+
+	/* hasta la vista, baby! */
+	gpt_zeroize_entry(gpt, partnum);
+
+	gpt_recompute_crc(gpt->pheader, gpt->ents);
+	gpt_recompute_crc(gpt->bheader, gpt->ents);
+	cxt->label->nparts_cur--;
+	fdisk_label_set_changed(cxt->label, 1);
+
+	return 0;
+}
+
+
+/* Performs logical checks to add a new partition entry */
+static int gpt_add_partition(
+		struct fdisk_context *cxt,
+		struct fdisk_partition *pa,
+		size_t *partno)
+{
+	uint64_t user_f, user_l;	/* user input ranges for first and last sectors */
+	uint64_t disk_f, disk_l;	/* first and last available sector ranges on device*/
+	uint64_t dflt_f, dflt_l, max_l;	/* largest segment (default) */
+	struct gpt_guid typeid;
+	struct fdisk_gpt_label *gpt;
+	struct gpt_header *pheader;
+	struct gpt_entry *e;
+	struct fdisk_ask *ask = NULL;
+	size_t partnum;
+	int rc;
+
+	assert(cxt);
+	assert(cxt->label);
+	assert(fdisk_is_label(cxt, GPT));
+
+	gpt = self_label(cxt);
+
+	assert(gpt);
+	assert(gpt->pheader);
+	assert(gpt->ents);
+
+	pheader = gpt->pheader;
+
+	rc = fdisk_partition_next_partno(pa, cxt, &partnum);
+	if (rc) {
+		DBG(GPT, ul_debug("failed to get next partno"));
+		return rc;
+	}
+
+	assert(partnum < gpt_get_nentries(gpt));
+
+	if (gpt_entry_is_used(gpt_get_entry(gpt, partnum))) {
+		fdisk_warnx(cxt, _("Partition %zu is already defined.  "
+			           "Delete it before re-adding it."), partnum +1);
+		return -ERANGE;
+	}
+	if (gpt_get_nentries(gpt) == partitions_in_use(gpt)) {
+		fdisk_warnx(cxt, _("All partitions are already in use."));
+		return -ENOSPC;
+	}
+	if (!get_free_sectors(cxt, gpt, NULL, NULL)) {
+		fdisk_warnx(cxt, _("No free sectors available."));
+		return -ENOSPC;
+	}
+
+	rc = string_to_guid(pa && pa->type && pa->type->typestr ?
+				pa->type->typestr:
+				GPT_DEFAULT_ENTRY_TYPE, &typeid);
+	if (rc)
+		return rc;
+
+	disk_f = find_first_available(gpt, le64_to_cpu(pheader->first_usable_lba));
+	e = gpt_get_entry(gpt, 0);
+
+	/* if first sector no explicitly defined then ignore small gaps before
+	 * the first partition */
+	if ((!pa || !fdisk_partition_has_start(pa))
+	    && gpt_entry_is_used(e)
+	    && disk_f < gpt_partition_start(e)) {
+
+		do {
+			uint64_t x;
+			DBG(GPT, ul_debug("testing first sector %"PRIu64"", disk_f));
+			disk_f = find_first_available(gpt, disk_f);
+			if (!disk_f)
+				break;
+			x = find_last_free(gpt, disk_f);
+			if (x - disk_f >= cxt->grain / cxt->sector_size)
+				break;
+			DBG(GPT, ul_debug("first sector %"PRIu64" addresses to small space, continue...", disk_f));
+			disk_f = x + 1ULL;
+		} while(1);
+
+		if (disk_f == 0)
+			disk_f = find_first_available(gpt, le64_to_cpu(pheader->first_usable_lba));
+	}
+
+	e = NULL;
+	disk_l = find_last_free_sector(gpt);
+
+	/* the default is the largest free space */
+	dflt_f = find_first_in_largest(gpt);
+	dflt_l = find_last_free(gpt, dflt_f);
+
+	/* don't offer too small free space by default, this is possible to
+	 * bypass by sfdisk script */
+	if ((!pa || !fdisk_partition_has_start(pa))
+	    && dflt_l - dflt_f + 1 < cxt->grain / cxt->sector_size) {
+		fdisk_warnx(cxt, _("No enough free sectors available."));
+		return -ENOSPC;
+	}
+
+	/* align the default in range <dflt_f,dflt_l>*/
+	dflt_f = fdisk_align_lba_in_range(cxt, dflt_f, dflt_f, dflt_l);
+
+	/* first sector */
+	if (pa && pa->start_follow_default) {
+		user_f = dflt_f;
+
+	} else if (pa && fdisk_partition_has_start(pa)) {
+		DBG(GPT, ul_debug("first sector defined: %ju",  (uintmax_t)pa->start));
+		if (pa->start != find_first_available(gpt, pa->start)) {
+			fdisk_warnx(cxt, _("Sector %ju already used."),  (uintmax_t)pa->start);
+			return -ERANGE;
+		}
+		user_f = pa->start;
+	} else {
+		/*  ask by dialog */
+		for (;;) {
+			if (!ask)
+				ask = fdisk_new_ask();
+			else
+				fdisk_reset_ask(ask);
+			if (!ask)
+				return -ENOMEM;
+
+			/* First sector */
+			fdisk_ask_set_query(ask, _("First sector"));
+			fdisk_ask_set_type(ask, FDISK_ASKTYPE_NUMBER);
+			fdisk_ask_number_set_low(ask,     disk_f);	/* minimal */
+			fdisk_ask_number_set_default(ask, dflt_f);	/* default */
+			fdisk_ask_number_set_high(ask,    disk_l);	/* maximal */
+
+			rc = fdisk_do_ask(cxt, ask);
+			if (rc)
+				goto done;
+
+			user_f = fdisk_ask_number_get_result(ask);
+			if (user_f != find_first_available(gpt, user_f)) {
+				fdisk_warnx(cxt, _("Sector %ju already used."), user_f);
+				continue;
+			}
+			break;
+		}
+	}
+
+
+	/* Last sector */
+	dflt_l = max_l = find_last_free(gpt, user_f);
+
+	/* Make sure the last partition has aligned size by default because
+	 * range specified by LastUsableLBA may be unaligned on disks where
+	 * logical sector != physical (512/4K) because backup header size is
+	 * calculated from logical sectors. */
+	if (max_l == le64_to_cpu(gpt->pheader->last_usable_lba))
+		dflt_l = fdisk_align_lba_in_range(cxt, max_l, user_f, max_l) - 1;
+
+	if (pa && pa->end_follow_default) {
+		user_l = dflt_l;
+
+	} else if (pa && fdisk_partition_has_size(pa)) {
+		user_l = user_f + pa->size - 1;
+		DBG(GPT, ul_debug("size defined: %ju, end: %"PRIu64
+				  "(last possible: %"PRIu64", optimal: %"PRIu64")",
+				(uintmax_t)pa->size, user_l, max_l, dflt_l));
+
+		if (user_l != dflt_l
+		    && !pa->size_explicit
+		    && alignment_required(cxt)
+		    && user_l - user_f > (cxt->grain / fdisk_get_sector_size(cxt))) {
+
+			user_l = fdisk_align_lba_in_range(cxt, user_l, user_f, dflt_l);
+			if (user_l > user_f)
+				user_l -= 1ULL;
+		}
+	} else {
+		for (;;) {
+			if (!ask)
+				ask = fdisk_new_ask();
+			else
+				fdisk_reset_ask(ask);
+			if (!ask)
+				return -ENOMEM;
+
+			fdisk_ask_set_query(ask, _("Last sector, +/-sectors or +/-size{K,M,G,T,P}"));
+			fdisk_ask_set_type(ask, FDISK_ASKTYPE_OFFSET);
+			fdisk_ask_number_set_low(ask,     user_f);	/* minimal */
+			fdisk_ask_number_set_default(ask, dflt_l);	/* default */
+			fdisk_ask_number_set_high(ask,    max_l);	/* maximal */
+			fdisk_ask_number_set_base(ask,    user_f);	/* base for relative input */
+			fdisk_ask_number_set_unit(ask,    cxt->sector_size);
+			fdisk_ask_number_set_wrap_negative(ask, 1);	/* wrap negative around high */
+
+			rc = fdisk_do_ask(cxt, ask);
+			if (rc)
+				goto done;
+
+			user_l = fdisk_ask_number_get_result(ask);
+			if (fdisk_ask_number_is_relative(ask)) {
+				user_l = fdisk_align_lba_in_range(cxt, user_l, user_f, dflt_l);
+				if (user_l > user_f)
+					user_l -= 1ULL;
+			}
+
+			if (user_l >= user_f && user_l <= disk_l)
+				break;
+
+			fdisk_warnx(cxt, _("Value out of range."));
+		}
+	}
+
+
+	if (user_f > user_l || partnum >= cxt->label->nparts_max) {
+		fdisk_warnx(cxt, _("Could not create partition %zu"), partnum + 1);
+		rc = -EINVAL;
+		goto done;
+	}
+
+	/* Be paranoid and check against on-disk setting rather than against libfdisk cxt */
+	if (user_l > le64_to_cpu(pheader->last_usable_lba)) {
+		fdisk_warnx(cxt, _("The last usable GPT sector is %ju, but %ju is requested."),
+				le64_to_cpu(pheader->last_usable_lba), user_l);
+		rc = -EINVAL;
+		goto done;
+	}
+
+	if (user_f < le64_to_cpu(pheader->first_usable_lba)) {
+		fdisk_warnx(cxt, _("The first usable GPT sector is %ju, but %ju is requested."),
+				le64_to_cpu(pheader->first_usable_lba), user_f);
+		rc = -EINVAL;
+		goto done;
+	}
+
+	assert(!FDISK_IS_UNDEF(user_l));
+	assert(!FDISK_IS_UNDEF(user_f));
+	assert(partnum < gpt_get_nentries(gpt));
+
+	e = gpt_get_entry(gpt, partnum);
+	e->lba_end = cpu_to_le64(user_l);
+	e->lba_start = cpu_to_le64(user_f);
+
+	gpt_entry_set_type(e, &typeid);
+
+	if (pa && pa->uuid) {
+		/* Sometimes it's necessary to create a copy of the PT and
+		 * reuse already defined UUID
+		 */
+		rc = gpt_entry_set_uuid(e, pa->uuid);
+		if (rc)
+			goto done;
+	} else {
+		/* Any time a new partition entry is created a new GUID must be
+		 * generated for that partition, and every partition is guaranteed
+		 * to have a unique GUID.
+		 */
+		struct gpt_guid guid;
+
+		uuid_generate_random((unsigned char *) &e->partition_guid);
+		guid = e->partition_guid;
+		swap_efi_guid(&guid);
+	}
+
+	if (pa && pa->name && *pa->name)
+		gpt_entry_set_name(e, pa->name);
+	if (pa && pa->attrs)
+		gpt_entry_attrs_from_string(cxt, e, pa->attrs);
+
+	DBG(GPT, ul_debug("new partition: partno=%zu, start=%"PRIu64", end=%"PRIu64", size=%"PRIu64"",
+				partnum,
+				gpt_partition_start(e),
+				gpt_partition_end(e),
+				gpt_partition_size(e)));
+
+	gpt_recompute_crc(gpt->pheader, gpt->ents);
+	gpt_recompute_crc(gpt->bheader, gpt->ents);
+
+	/* report result */
+	{
+		struct fdisk_parttype *t;
+
+		cxt->label->nparts_cur++;
+		fdisk_label_set_changed(cxt->label, 1);
+
+		t = gpt_partition_parttype(cxt, e);
+		fdisk_info_new_partition(cxt, partnum + 1, user_f, user_l, t);
+		fdisk_unref_parttype(t);
+	}
+
+	rc = 0;
+	if (partno)
+		*partno = partnum;
+done:
+	fdisk_unref_ask(ask);
+	return rc;
+}
+
+/*
+ * Create a new GPT disklabel - destroys any previous data.
+ */
+static int gpt_create_disklabel(struct fdisk_context *cxt)
+{
+	int rc = 0;
+	size_t esz = 0;
+	char str[UUID_STR_LEN];
+	struct fdisk_gpt_label *gpt;
+	struct gpt_guid guid;
+
+	assert(cxt);
+	assert(cxt->label);
+	assert(fdisk_is_label(cxt, GPT));
+
+	gpt = self_label(cxt);
+
+	/* label private stuff has to be empty, see gpt_deinit() */
+	assert(gpt->pheader == NULL);
+	assert(gpt->bheader == NULL);
+
+	/*
+	 * When no header, entries or pmbr is set, we're probably
+	 * dealing with a new, empty disk - so always allocate memory
+	 * to deal with the data structures whatever the case is.
+	 */
+	rc = gpt_mknew_pmbr(cxt);
+	if (rc < 0)
+		goto done;
+
+	assert(cxt->sector_size >= sizeof(struct gpt_header));
+
+	/* primary */
+	gpt->pheader = calloc(1, cxt->sector_size);
+	if (!gpt->pheader) {
+		rc = -ENOMEM;
+		goto done;
+	}
+	rc = gpt_mknew_header(cxt, gpt->pheader, GPT_PRIMARY_PARTITION_TABLE_LBA);
+	if (rc < 0)
+		goto done;
+
+	/* backup ("copy" primary) */
+	gpt->bheader = calloc(1, cxt->sector_size);
+	if (!gpt->bheader) {
+		rc = -ENOMEM;
+		goto done;
+	}
+	rc = gpt_mknew_header_from_bkp(cxt, gpt->bheader,
+			last_lba(cxt), gpt->pheader);
+	if (rc < 0)
+		goto done;
+
+	rc = gpt_sizeof_entries(gpt->pheader, &esz);
+	if (rc)
+		goto done;
+	gpt->ents = calloc(1, esz);
+	if (!gpt->ents) {
+		rc = -ENOMEM;
+		goto done;
+	}
+	gpt_recompute_crc(gpt->pheader, gpt->ents);
+	gpt_recompute_crc(gpt->bheader, gpt->ents);
+
+	cxt->label->nparts_max = gpt_get_nentries(gpt);
+	cxt->label->nparts_cur = 0;
+
+	guid = gpt->pheader->disk_guid;
+	guid_to_string(&guid, str);
+	fdisk_label_set_changed(cxt->label, 1);
+	fdisk_info(cxt, _("Created a new GPT disklabel (GUID: %s)."), str);
+
+	if (gpt_get_nentries(gpt) < GPT_NPARTITIONS)
+		fdisk_info(cxt, _("The maximal number of partitions is %zu (default is %zu)."),
+				gpt_get_nentries(gpt), GPT_NPARTITIONS);
+done:
+	return rc;
+}
+
+static int gpt_set_disklabel_id(struct fdisk_context *cxt, const char *str)
+{
+	struct fdisk_gpt_label *gpt;
+	struct gpt_guid uuid;
+	char *old, *new;
+	int rc;
+
+	assert(cxt);
+	assert(cxt->label);
+	assert(fdisk_is_label(cxt, GPT));
+
+	gpt = self_label(cxt);
+	if (!str) {
+		char *buf = NULL;
+
+		if (fdisk_ask_string(cxt,
+				_("Enter new disk UUID (in 8-4-4-4-12 format)"), &buf))
+			return -EINVAL;
+		rc = string_to_guid(buf, &uuid);
+		free(buf);
+	} else
+		rc = string_to_guid(str, &uuid);
+
+	if (rc) {
+		fdisk_warnx(cxt, _("Failed to parse your UUID."));
+		return rc;
+	}
+
+	old = gpt_get_header_id(gpt->pheader);
+
+	gpt->pheader->disk_guid = uuid;
+	gpt->bheader->disk_guid = uuid;
+
+	gpt_recompute_crc(gpt->pheader, gpt->ents);
+	gpt_recompute_crc(gpt->bheader, gpt->ents);
+
+	new = gpt_get_header_id(gpt->pheader);
+
+	fdisk_info(cxt, _("Disk identifier changed from %s to %s."), old, new);
+
+	free(old);
+	free(new);
+	fdisk_label_set_changed(cxt->label, 1);
+	return 0;
+}
+
+static int gpt_check_table_overlap(struct fdisk_context *cxt,
+				   uint64_t first_usable,
+				   uint64_t last_usable)
+{
+	struct fdisk_gpt_label *gpt = self_label(cxt);
+	size_t i;
+	int rc = 0;
+
+	/* First check if there's enough room for the table. last_lba may have wrapped */
+	if (first_usable > cxt->total_sectors || /* far too little space */
+	    last_usable > cxt->total_sectors || /* wrapped */
+	    first_usable > last_usable) { /* too little space */
+		fdisk_warnx(cxt, _("Not enough space for new partition table!"));
+		return -ENOSPC;
+	}
+
+	/* check that all partitions fit in the remaining space */
+	for (i = 0; i < gpt_get_nentries(gpt); i++) {
+		struct gpt_entry *e = gpt_get_entry(gpt, i);
+
+		if (!gpt_entry_is_used(e))
+		        continue;
+		if (gpt_partition_start(e) < first_usable) {
+			fdisk_warnx(cxt, _("Partition #%zu out of range (minimal start is %"PRIu64" sectors)"),
+		                    i + 1, first_usable);
+			rc = -EINVAL;
+		}
+		if (gpt_partition_end(e) > last_usable) {
+			fdisk_warnx(cxt, _("Partition #%zu out of range (maximal end is %"PRIu64" sectors)"),
+		                    i + 1, last_usable - (uint64_t) 1);
+			rc = -EINVAL;
+		}
+	}
+	return rc;
+}
+
+/**
+ * fdisk_gpt_set_npartitions:
+ * @cxt: context
+ * @nents: number of wanted entries
+ *
+ * Elarge GPT entries array if possible. The function check if an existing
+ * partition does not overlap the entries array area. If yes, then it report
+ * warning and returns -EINVAL.
+ *
+ * Returns: 0 on success, < 0 on error.
+ * Since: 2.29
+ */
+int fdisk_gpt_set_npartitions(struct fdisk_context *cxt, uint32_t nents)
+{
+	struct fdisk_gpt_label *gpt;
+	size_t new_size = 0;
+	uint32_t old_nents;
+	uint64_t first_usable = 0ULL, last_usable = 0ULL;
+	int rc;
+
+	assert(cxt);
+	assert(cxt->label);
+
+	if (!fdisk_is_label(cxt, GPT))
+		return -EINVAL;
+
+	gpt = self_label(cxt);
+
+	old_nents = le32_to_cpu(gpt->pheader->npartition_entries);
+	if (old_nents == nents)
+		return 0;	/* do nothing, say nothing */
+
+	/* calculate the size (bytes) of the entries array */
+	rc = gpt_calculate_sizeof_entries(gpt->pheader, nents, &new_size);
+	if (rc) {
+		uint32_t entry_size = le32_to_cpu(gpt->pheader->sizeof_partition_entry);
+
+		if (entry_size == 0)
+			fdisk_warnx(cxt, _("The partition entry size is zero."));
+		else
+			fdisk_warnx(cxt, _("The number of the partition has to be smaller than %zu."),
+				(size_t) UINT32_MAX / entry_size);
+		return rc;
+	}
+
+	rc = gpt_calculate_first_lba(gpt->pheader, nents, &first_usable, cxt);
+	if (rc == 0)
+		rc = gpt_calculate_last_lba(gpt->pheader, nents, &last_usable, cxt);
+	if (rc)
+		return rc;
+
+	/* if expanding the table, first check that everything fits,
+	 * then allocate more memory and zero. */
+	if (nents > old_nents) {
+		unsigned char *ents;
+		size_t old_size = 0;
+
+		rc = gpt_calculate_sizeof_entries(gpt->pheader, old_nents, &old_size);
+		if (rc == 0)
+			rc = gpt_check_table_overlap(cxt, first_usable, last_usable);
+		if (rc)
+			return rc;
+		ents = realloc(gpt->ents, new_size);
+		if (!ents) {
+			fdisk_warnx(cxt, _("Cannot allocate memory!"));
+			return -ENOMEM;
+		}
+		memset(ents + old_size, 0, new_size - old_size);
+		gpt->ents = ents;
+	}
+
+	/* everything's ok, apply the new size */
+	gpt->pheader->npartition_entries = cpu_to_le32(nents);
+	gpt->bheader->npartition_entries = cpu_to_le32(nents);
+
+	/* usable LBA addresses will have changed */
+	fdisk_set_first_lba(cxt, first_usable);
+	fdisk_set_last_lba(cxt, last_usable);
+	gpt->pheader->first_usable_lba = cpu_to_le64(first_usable);
+	gpt->bheader->first_usable_lba = cpu_to_le64(first_usable);
+	gpt->pheader->last_usable_lba = cpu_to_le64(last_usable);
+	gpt->bheader->last_usable_lba = cpu_to_le64(last_usable);
+
+	/* The backup header must be recalculated */
+	gpt_mknew_header_common(cxt, gpt->bheader, le64_to_cpu(gpt->pheader->alternative_lba));
+
+	/* CRCs will have changed */
+	gpt_recompute_crc(gpt->pheader, gpt->ents);
+	gpt_recompute_crc(gpt->bheader, gpt->ents);
+
+	/* update library info */
+	cxt->label->nparts_max = gpt_get_nentries(gpt);
+
+	fdisk_info(cxt, _("Partition table length changed from %"PRIu32" to %"PRIu32"."),
+			old_nents, nents);
+
+	fdisk_label_set_changed(cxt->label, 1);
+	return 0;
+}
+
+static int gpt_part_is_used(struct fdisk_context *cxt, size_t i)
+{
+	struct fdisk_gpt_label *gpt;
+	struct gpt_entry *e;
+
+	assert(cxt);
+	assert(cxt->label);
+	assert(fdisk_is_label(cxt, GPT));
+
+	gpt = self_label(cxt);
+
+	if (i >= gpt_get_nentries(gpt))
+		return 0;
+
+	e = gpt_get_entry(gpt, i);
+
+	return gpt_entry_is_used(e) || gpt_partition_start(e);
+}
+
+/**
+ * fdisk_gpt_is_hybrid:
+ * @cxt: context
+ *
+ * The regular GPT contains PMBR (dummy protective MBR) where the protective
+ * MBR does not address any partitions.
+ *
+ * Hybrid GPT contains regular MBR where this partition table addresses the
+ * same partitions as GPT. It's recommended to not use hybrid GPT due to MBR
+ * limits.
+ *
+ * The libfdisk does not provide functionality to sync GPT and MBR, you have to
+ * directly access and modify (P)MBR (see fdisk_new_nested_context()).
+ *
+ * Returns: 1 if partition table detected as hybrid otherwise return 0
+ */
+int fdisk_gpt_is_hybrid(struct fdisk_context *cxt)
+{
+	assert(cxt);
+	return valid_pmbr(cxt) == GPT_MBR_HYBRID;
+}
+
+/**
+ * fdisk_gpt_get_partition_attrs:
+ * @cxt: context
+ * @partnum: partition number
+ * @attrs: GPT partition attributes
+ *
+ * Sets @attrs for the given partition
+ *
+ * Returns: 0 on success, <0 on error.
+ */
+int fdisk_gpt_get_partition_attrs(
+		struct fdisk_context *cxt,
+		size_t partnum,
+		uint64_t *attrs)
+{
+	struct fdisk_gpt_label *gpt;
+
+	assert(cxt);
+	assert(cxt->label);
+
+	if (!fdisk_is_label(cxt, GPT))
+		return -EINVAL;
+
+	gpt = self_label(cxt);
+
+	if (partnum >= gpt_get_nentries(gpt))
+		return -EINVAL;
+
+	*attrs = le64_to_cpu(gpt_get_entry(gpt, partnum)->attrs);
+	return 0;
+}
+
+/**
+ * fdisk_gpt_set_partition_attrs:
+ * @cxt: context
+ * @partnum: partition number
+ * @attrs: GPT partition attributes
+ *
+ * Sets the GPT partition attributes field to @attrs.
+ *
+ * Returns: 0 on success, <0 on error.
+ */
+int fdisk_gpt_set_partition_attrs(
+		struct fdisk_context *cxt,
+		size_t partnum,
+		uint64_t attrs)
+{
+	struct fdisk_gpt_label *gpt;
+
+	assert(cxt);
+	assert(cxt->label);
+
+	if (!fdisk_is_label(cxt, GPT))
+		return -EINVAL;
+
+	DBG(GPT, ul_debug("entry attributes change requested partno=%zu", partnum));
+	gpt = self_label(cxt);
+
+	if (partnum >= gpt_get_nentries(gpt))
+		return -EINVAL;
+
+	gpt_get_entry(gpt, partnum)->attrs = cpu_to_le64(attrs);
+	fdisk_info(cxt, _("The attributes on partition %zu changed to 0x%016" PRIx64 "."),
+			partnum + 1, attrs);
+
+	gpt_recompute_crc(gpt->pheader, gpt->ents);
+	gpt_recompute_crc(gpt->bheader, gpt->ents);
+	fdisk_label_set_changed(cxt->label, 1);
+	return 0;
+}
+
+static int gpt_toggle_partition_flag(
+		struct fdisk_context *cxt,
+		size_t i,
+		unsigned long flag)
+{
+	struct fdisk_gpt_label *gpt;
+	struct gpt_entry *e;
+	uint64_t attrs;
+	uintmax_t tmp;
+	char *bits;
+	const char *name = NULL;
+	int bit = -1, rc;
+
+	assert(cxt);
+	assert(cxt->label);
+	assert(fdisk_is_label(cxt, GPT));
+
+	DBG(GPT, ul_debug("entry attribute change requested partno=%zu", i));
+	gpt = self_label(cxt);
+
+	if (i >= gpt_get_nentries(gpt))
+		return -EINVAL;
+
+	e = gpt_get_entry(gpt, i);
+	attrs = e->attrs;
+	bits = (char *) &attrs;
+
+	switch (flag) {
+	case GPT_FLAG_REQUIRED:
+		bit = GPT_ATTRBIT_REQ;
+		name = GPT_ATTRSTR_REQ;
+		break;
+	case GPT_FLAG_NOBLOCK:
+		bit = GPT_ATTRBIT_NOBLOCK;
+		name = GPT_ATTRSTR_NOBLOCK;
+		break;
+	case GPT_FLAG_LEGACYBOOT:
+		bit = GPT_ATTRBIT_LEGACY;
+		name = GPT_ATTRSTR_LEGACY;
+		break;
+	case GPT_FLAG_GUIDSPECIFIC:
+		rc = fdisk_ask_number(cxt, 48, 48, 63, _("Enter GUID specific bit"), &tmp);
+		if (rc)
+			return rc;
+		bit = tmp;
+		break;
+	default:
+		/* already specified PT_FLAG_GUIDSPECIFIC bit */
+		if (flag >= 48 && flag <= 63) {
+			bit = flag;
+			flag = GPT_FLAG_GUIDSPECIFIC;
+		}
+		break;
+	}
+
+	if (bit < 0) {
+		fdisk_warnx(cxt, _("failed to toggle unsupported bit %lu"), flag);
+		return -EINVAL;
+	}
+
+	if (!isset(bits, bit))
+		setbit(bits, bit);
+	else
+		clrbit(bits, bit);
+
+	e->attrs = attrs;
+
+	if (flag == GPT_FLAG_GUIDSPECIFIC)
+		fdisk_info(cxt, isset(bits, bit) ?
+			_("The GUID specific bit %d on partition %zu is enabled now.") :
+			_("The GUID specific bit %d on partition %zu is disabled now."),
+			bit, i + 1);
+	else
+		fdisk_info(cxt, isset(bits, bit) ?
+			_("The %s flag on partition %zu is enabled now.") :
+			_("The %s flag on partition %zu is disabled now."),
+			name, i + 1);
+
+	gpt_recompute_crc(gpt->pheader, gpt->ents);
+	gpt_recompute_crc(gpt->bheader, gpt->ents);
+	fdisk_label_set_changed(cxt->label, 1);
+	return 0;
+}
+
+static int gpt_entry_cmp_start(const void *a, const void *b)
+{
+	const struct gpt_entry  *ae = (const struct gpt_entry *) a,
+				*be = (const struct gpt_entry *) b;
+	int au = gpt_entry_is_used(ae),
+	    bu = gpt_entry_is_used(be);
+
+	if (!au && !bu)
+		return 0;
+	if (!au)
+		return 1;
+	if (!bu)
+		return -1;
+
+	return cmp_numbers(gpt_partition_start(ae), gpt_partition_start(be));
+}
+
+/* sort partition by start sector */
+static int gpt_reorder(struct fdisk_context *cxt)
+{
+	struct fdisk_gpt_label *gpt;
+	size_t i, nparts, mess;
+
+	assert(cxt);
+	assert(cxt->label);
+	assert(fdisk_is_label(cxt, GPT));
+
+	gpt = self_label(cxt);
+	nparts = gpt_get_nentries(gpt);
+
+	for (i = 0, mess = 0; mess == 0 && i + 1 < nparts; i++)
+		mess = gpt_entry_cmp_start(
+				(const void *) gpt_get_entry(gpt, i),
+				(const void *) gpt_get_entry(gpt, i + 1)) > 0;
+
+	if (!mess)
+		return 1;
+
+	qsort(gpt->ents, nparts, sizeof(struct gpt_entry),
+			gpt_entry_cmp_start);
+
+	gpt_recompute_crc(gpt->pheader, gpt->ents);
+	gpt_recompute_crc(gpt->bheader, gpt->ents);
+	fdisk_label_set_changed(cxt->label, 1);
+
+	return 0;
+}
+
+static int gpt_reset_alignment(struct fdisk_context *cxt)
+{
+	struct fdisk_gpt_label *gpt;
+	struct gpt_header *h;
+
+	assert(cxt);
+	assert(cxt->label);
+	assert(fdisk_is_label(cxt, GPT));
+
+	gpt = self_label(cxt);
+	h = gpt ? gpt->pheader : NULL;
+
+	if (h) {
+		/* always follow existing table */
+		cxt->first_lba = le64_to_cpu(h->first_usable_lba);
+		cxt->last_lba  = le64_to_cpu(h->last_usable_lba);
+	} else {
+		/* estimate ranges for GPT */
+		uint64_t first, last;
+
+		count_first_last_lba(cxt, &first, &last, NULL);
+		if (cxt->first_lba < first)
+			cxt->first_lba = first;
+		if (cxt->last_lba > last)
+			cxt->last_lba = last;
+	}
+
+	return 0;
+}
+/*
+ * Deinitialize fdisk-specific variables
+ */
+static void gpt_deinit(struct fdisk_label *lb)
+{
+	struct fdisk_gpt_label *gpt = (struct fdisk_gpt_label *) lb;
+
+	if (!gpt)
+		return;
+
+	free(gpt->ents);
+	free(gpt->pheader);
+	free(gpt->bheader);
+
+	gpt->ents = NULL;
+	gpt->pheader = NULL;
+	gpt->bheader = NULL;
+}
+
+static const struct fdisk_label_operations gpt_operations =
+{
+	.probe		= gpt_probe_label,
+	.write		= gpt_write_disklabel,
+	.verify		= gpt_verify_disklabel,
+	.create		= gpt_create_disklabel,
+	.locate		= gpt_locate_disklabel,
+	.get_item	= gpt_get_disklabel_item,
+	.set_id		= gpt_set_disklabel_id,
+
+	.get_part	= gpt_get_partition,
+	.set_part	= gpt_set_partition,
+	.add_part	= gpt_add_partition,
+	.del_part	= gpt_delete_partition,
+	.reorder	= gpt_reorder,
+
+	.part_is_used	= gpt_part_is_used,
+	.part_toggle_flag = gpt_toggle_partition_flag,
+
+	.deinit		= gpt_deinit,
+
+	.reset_alignment = gpt_reset_alignment
+};
+
+static const struct fdisk_field gpt_fields[] =
+{
+	/* basic */
+	{ FDISK_FIELD_DEVICE,	N_("Device"),	 10,	0 },
+	{ FDISK_FIELD_START,	N_("Start"),	  5,	FDISK_FIELDFL_NUMBER },
+	{ FDISK_FIELD_END,	N_("End"),	  5,	FDISK_FIELDFL_NUMBER },
+	{ FDISK_FIELD_SECTORS,	N_("Sectors"),	  5,	FDISK_FIELDFL_NUMBER },
+	{ FDISK_FIELD_SIZE,	N_("Size"),	  5,	FDISK_FIELDFL_NUMBER | FDISK_FIELDFL_EYECANDY },
+	{ FDISK_FIELD_TYPE,	N_("Type"),	0.1,	FDISK_FIELDFL_EYECANDY },
+	/* expert */
+	{ FDISK_FIELD_TYPEID,	N_("Type-UUID"), 36,	FDISK_FIELDFL_DETAIL },
+	{ FDISK_FIELD_UUID,	N_("UUID"),	 36,	FDISK_FIELDFL_DETAIL },
+	{ FDISK_FIELD_NAME,	N_("Name"),	0.2,	FDISK_FIELDFL_DETAIL },
+	{ FDISK_FIELD_ATTR,	N_("Attrs"),	  0,	FDISK_FIELDFL_DETAIL }
+};
+
+/*
+ * allocates GPT in-memory stuff
+ */
+struct fdisk_label *fdisk_new_gpt_label(struct fdisk_context *cxt __attribute__ ((__unused__)))
+{
+	struct fdisk_label *lb;
+	struct fdisk_gpt_label *gpt;
+
+	gpt = calloc(1, sizeof(*gpt));
+	if (!gpt)
+		return NULL;
+
+	/* initialize generic part of the driver */
+	lb = (struct fdisk_label *) gpt;
+	lb->name = "gpt";
+	lb->id = FDISK_DISKLABEL_GPT;
+	lb->op = &gpt_operations;
+
+	lb->parttypes = gpt_parttypes;
+	lb->nparttypes = ARRAY_SIZE(gpt_parttypes);
+	lb->parttype_cuts = gpt_parttype_cuts;
+	lb->nparttype_cuts = ARRAY_SIZE(gpt_parttype_cuts);
+
+	lb->fields = gpt_fields;
+	lb->nfields = ARRAY_SIZE(gpt_fields);
+
+	/* return calloc() result to keep static anaylizers happy */
+	return (struct fdisk_label *) gpt;
+}
+
+/**
+ * fdisk_gpt_disable_relocation
+ * @lb: label
+ * @disable: 0 or 1
+ *
+ * Disable automatic backup header relocation to the end of the device. The
+ * header position is recalculated during libfdisk probing stage by
+ * fdisk_assign_device() and later written by fdisk_write_disklabel(), so you
+ * need to call it before fdisk_assign_device().
+ *
+ * Since: 2.36
+ */
+void fdisk_gpt_disable_relocation(struct fdisk_label *lb, int disable)
+{
+	struct fdisk_gpt_label *gpt = (struct fdisk_gpt_label *) lb;
+
+	assert(gpt);
+	gpt->no_relocate = disable ? 1 : 0;
+}
+
+/**
+ * fdisk_gpt_enable_minimize
+ * @lb: label
+ * @enable: 0 or 1
+ *
+ * Force libfdisk to write backup header to behind last partition. The
+ * header position is recalculated on fdisk_write_disklabel().
+ *
+ * Since: 2.36
+ */
+void fdisk_gpt_enable_minimize(struct fdisk_label *lb, int enable)
+{
+	struct fdisk_gpt_label *gpt = (struct fdisk_gpt_label *) lb;
+
+	assert(gpt);
+	gpt->minimize = enable ? 1 : 0;
+}
+
+#ifdef TEST_PROGRAM
+static int test_getattr(struct fdisk_test *ts, int argc, char *argv[])
+{
+	const char *disk = argv[1];
+	size_t part = strtoul(argv[2], NULL, 0) - 1;
+	struct fdisk_context *cxt;
+	uint64_t atters = 0;
+
+	cxt = fdisk_new_context();
+	fdisk_assign_device(cxt, disk, 1);
+
+	if (!fdisk_is_label(cxt, GPT))
+		return EXIT_FAILURE;
+
+	if (fdisk_gpt_get_partition_attrs(cxt, part, &atters))
+		return EXIT_FAILURE;
+
+	printf("%s: 0x%016" PRIx64 "\n", argv[2], atters);
+
+	fdisk_unref_context(cxt);
+	return 0;
+}
+
+static int test_setattr(struct fdisk_test *ts, int argc, char *argv[])
+{
+	const char *disk = argv[1];
+	size_t part = strtoul(argv[2], NULL, 0) - 1;
+	uint64_t atters = strtoull(argv[3], NULL, 0);
+	struct fdisk_context *cxt;
+
+	cxt = fdisk_new_context();
+	fdisk_assign_device(cxt, disk, 0);
+
+	if (!fdisk_is_label(cxt, GPT))
+		return EXIT_FAILURE;
+
+	if (fdisk_gpt_set_partition_attrs(cxt, part, atters))
+		return EXIT_FAILURE;
+
+	if (fdisk_write_disklabel(cxt))
+		return EXIT_FAILURE;
+
+	fdisk_unref_context(cxt);
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	struct fdisk_test tss[] = {
+		{ "--getattr",  test_getattr,  "<disk> <partition>             print attributes" },
+		{ "--setattr",  test_setattr,  "<disk> <partition> <value>     set attributes" },
+		{ NULL }
+	};
+
+	return fdisk_run_test(tss, argc, argv);
+}
+
+#endif