libfdisk: move mbr code to the library

Signed-off-by: Karel Zak <kzak@redhat.com>

1 files changed, 1916 insertions, 0 deletions

diff --git a/libfdisk/src/dos.c b/libfdisk/src/dos.c
new file mode 100644
index 000000000..ef426cfa1
--- /dev/null
+++ b/libfdisk/src/dos.c
@@ -0,0 +1,1916 @@
+/*
+ *
+ * Copyright (C) 2007-2013 Karel Zak <kzak@redhat.com>
+ *                    2012 Davidlohr Bueso <dave@gnu.org>
+ *
+ * This is re-written version for libfdisk, the original was fdiskdoslabel.c
+ * from util-linux fdisk.
+ */
+#include "c.h"
+#include "nls.h"
+#include "randutils.h"
+#include "pt-mbr.h"
+
+#include "fdiskP.h"
+
+#include <ctype.h>
+
+#define MAXIMUM_PARTS	60
+#define ACTIVE_FLAG     0x80
+
+#define IS_EXTENDED(i) \
+	((i) == MBR_DOS_EXTENDED_PARTITION \
+	 || (i) == MBR_W95_EXTENDED_PARTITION \
+	 || (i) == MBR_LINUX_EXTENDED_PARTITION)
+
+/*
+ * per partition table entry data
+ *
+ * The four primary partitions have the same sectorbuffer
+ * and have NULL ex_entry.
+ *
+ * Each logical partition table entry has two pointers, one for the
+ * partition and one link to the next one.
+ */
+struct pte {
+	struct dos_partition *pt_entry;	/* on-disk MBR entry */
+	struct dos_partition *ex_entry;	/* on-disk EBR entry */
+	sector_t offset;	        /* disk sector number */
+	unsigned char *sectorbuffer;	/* disk sector contents */
+
+	unsigned int changed : 1,
+		     private_sectorbuffer : 1;
+};
+
+/*
+ * in-memory fdisk GPT stuff
+ */
+struct fdisk_dos_label {
+	struct fdisk_label	head;		/* generic part */
+
+	struct pte	ptes[MAXIMUM_PARTS];	/* partition */
+	sector_t	ext_offset;
+	size_t		ext_index;
+	unsigned int	compatible : 1,		/* is DOS compatible? */
+			non_pt_changed : 1;	/* MBR, but no PT changed */
+};
+
+/*
+ * Partition types
+ */
+static struct fdisk_parttype dos_parttypes[] = {
+	#include "pt-mbr-partnames.h"
+};
+
+#define set_hsc(h,s,c,sector) { \
+		s = sector % cxt->geom.sectors + 1;			\
+		sector /= cxt->geom.sectors;				\
+		h = sector % cxt->geom.heads;				\
+		sector /= cxt->geom.heads;				\
+		c = sector & 0xff;					\
+		s |= (sector >> 2) & 0xc0;				\
+	}
+
+
+#define sector(s)	((s) & 0x3f)
+#define cylinder(s, c)	((c) | (((s) & 0xc0) << 2))
+
+#define alignment_required(_x)	((_x)->grain != (_x)->sector_size)
+
+#define is_dos_compatible(_x) \
+		   (fdisk_is_disklabel(_x, DOS) && \
+                    fdisk_dos_is_compatible(fdisk_context_get_label(_x, NULL)))
+
+#define cround(c, n)	fdisk_scround(c, n)
+
+
+static inline struct fdisk_dos_label *self_label(struct fdisk_context *cxt)
+{
+	assert(cxt);
+	assert(cxt->label);
+	assert(fdisk_is_disklabel(cxt, DOS));
+
+	return (struct fdisk_dos_label *) cxt->label;
+}
+
+static inline struct pte *self_pte(struct fdisk_context *cxt, size_t i)
+{
+	struct fdisk_dos_label *l = self_label(cxt);
+
+	if (i >= ARRAY_SIZE(l->ptes))
+		return NULL;
+
+	return &l->ptes[i];
+}
+
+static inline struct dos_partition *self_partition(
+				struct fdisk_context *cxt,
+				size_t i)
+{
+	struct pte *pe = self_pte(cxt, i);
+	return pe ? pe->pt_entry : NULL;
+}
+
+struct dos_partition *fdisk_dos_get_partition(
+				struct fdisk_context *cxt,
+				size_t i)
+{
+	return self_partition(cxt, i);
+}
+
+static void partition_set_changed(
+				struct fdisk_context *cxt,
+				size_t i,
+				int changed)
+{
+	struct pte *pe = self_pte(cxt, i);
+
+	if (!pe)
+		return;
+
+	pe->changed = changed ? 1 : 0;
+	if (changed)
+		fdisk_label_set_changed(cxt->label, 1);
+}
+
+static sector_t get_abs_partition_start(struct pte *pe)
+{
+	return pe->offset + dos_partition_get_start(pe->pt_entry);
+}
+
+static int is_cleared_partition(struct dos_partition *p)
+{
+	return !(!p || p->boot_ind || p->bh || p->bs || p->bc ||
+		 p->sys_ind || p->eh || p->es || p->ec ||
+		 dos_partition_get_start(p) || dos_partition_get_size(p));
+}
+
+static int get_partition_unused_primary(struct fdisk_context *cxt)
+{
+	size_t orgmax = cxt->label->nparts_max;
+	size_t n;
+	int rc;
+
+	cxt->label->nparts_max = 4;
+	rc = fdisk_ask_partnum(cxt, &n, TRUE);
+	cxt->label->nparts_max = orgmax;
+
+	switch (rc) {
+	case 1:
+		fdisk_info(cxt, _("All primary partitions have been defined already"));
+		return -1;
+	case 0:
+		return n;
+	default:
+		return rc;
+	}
+}
+
+static int seek_sector(struct fdisk_context *cxt, sector_t secno)
+{
+	off_t offset = (off_t) secno * cxt->sector_size;
+
+	return lseek(cxt->dev_fd, offset, SEEK_SET) == (off_t) -1 ? -errno : 0;
+}
+
+static int read_sector(struct fdisk_context *cxt, sector_t secno,
+			unsigned char *buf)
+{
+	int rc = seek_sector(cxt, secno);
+
+	if (rc < 0)
+		return rc;
+
+	return read(cxt->dev_fd, buf, cxt->sector_size) !=
+			(ssize_t) cxt->sector_size ? -errno : 0;
+}
+
+/* Allocate a buffer and read a partition table sector */
+static int read_pte(struct fdisk_context *cxt, int pno, sector_t offset)
+{
+	unsigned char *buf;
+	struct pte *pe = self_pte(cxt, pno);
+
+	buf = calloc(1, cxt->sector_size);
+	if (!buf)
+		return -ENOMEM;
+
+	pe->offset = offset;
+	pe->sectorbuffer = buf;
+	pe->private_sectorbuffer = 1;
+
+	if (read_sector(cxt, offset, pe->sectorbuffer) != 0)
+		fdisk_warn(cxt, _("Failed to read extended partition table "
+				"(offset=%jd)"), (uintmax_t) offset);
+	pe->changed = 0;
+	pe->pt_entry = pe->ex_entry = NULL;
+	return 0;
+}
+
+
+static void clear_partition(struct dos_partition *p)
+{
+	if (!p)
+		return;
+	p->boot_ind = 0;
+	p->bh = 0;
+	p->bs = 0;
+	p->bc = 0;
+	p->sys_ind = 0;
+	p->eh = 0;
+	p->es = 0;
+	p->ec = 0;
+	dos_partition_set_start(p,0);
+	dos_partition_set_size(p,0);
+}
+
+static void dos_init(struct fdisk_context *cxt)
+{
+	struct fdisk_dos_label *l = self_label(cxt);
+	size_t i;
+
+	cxt->label->nparts_max = 4;	/* default, unlimited number of logical */
+
+	l->ext_index = 0;
+	l->ext_offset = 0;
+	l->non_pt_changed = 0;
+
+	memset(l->ptes, 0, sizeof(l->ptes));
+
+	for (i = 0; i < 4; i++) {
+		struct pte *pe = self_pte(cxt, i);
+
+		pe->pt_entry = mbr_get_partition(cxt->firstsector, i);
+		pe->ex_entry = NULL;
+		pe->offset = 0;
+		pe->sectorbuffer = cxt->firstsector;
+		pe->changed = 0;
+	}
+
+	if (fdisk_context_listonly(cxt))
+		return;
+	/*
+	 * Various warnings...
+	 */
+	if (fdisk_missing_geometry(cxt))
+		fdisk_warnx(cxt, _("You can set geometry from the extra functions menu."));
+
+	if (is_dos_compatible(cxt)) {
+		fdisk_warnx(cxt, _("DOS-compatible mode is deprecated."));
+
+		if (cxt->sector_size != cxt->phy_sector_size)
+			fdisk_info(cxt, _(
+		"The device presents a logical sector size that is smaller than "
+		"the physical sector size. Aligning to a physical sector (or optimal "
+		"I/O) size boundary is recommended, or performance may be impacted."));
+	}
+
+	if (fdisk_context_use_cylinders(cxt))
+		fdisk_warnx(cxt, _("Cylinders as display units are deprecated."));
+
+	if (cxt->total_sectors > UINT_MAX) {
+		unsigned long long bytes = cxt->total_sectors * cxt->sector_size;
+		int giga = bytes / 1000000000;
+		int hectogiga = (giga + 50) / 100;
+
+		fdisk_warnx(cxt,
+		_("The size of this disk is %d.%d TB (%llu bytes). DOS "
+		  "partition table format can not be used on drives for "
+		  "volumes larger than (%llu bytes) for %ld-byte "
+		  "sectors. Use GUID partition table format (GPT)."),
+			hectogiga / 10, hectogiga % 10,
+			bytes,
+			(sector_t ) UINT_MAX * cxt->sector_size,
+			cxt->sector_size);
+	}
+}
+
+/* callback called by libfdisk */
+static void dos_deinit(struct fdisk_label *lb)
+{
+	size_t i;
+	struct fdisk_dos_label *l = (struct fdisk_dos_label *) lb;
+
+	for (i = 0; i < ARRAY_SIZE(l->ptes); i++) {
+		struct pte *pe = &l->ptes[i];
+
+		if (pe->private_sectorbuffer)
+			free(pe->sectorbuffer);
+		pe->sectorbuffer = NULL;
+	}
+
+	memset(l->ptes, 0, sizeof(l->ptes));
+}
+
+static int dos_delete_partition(struct fdisk_context *cxt, size_t partnum)
+{
+	struct fdisk_dos_label *l = self_label(cxt);
+	struct pte *pe = self_pte(cxt, partnum);
+	struct dos_partition *p;
+	struct dos_partition *q;
+
+	if (!pe)
+		return -EINVAL;
+
+	p = pe->pt_entry;
+	q = pe->ex_entry;
+
+	/* Note that for the fifth partition (partnum == 4) we don't actually
+	   decrement partitions. */
+	if (partnum < 4) {
+		if (IS_EXTENDED(p->sys_ind) && partnum == l->ext_index) {
+			cxt->label->nparts_max = 4;
+			l->ptes[l->ext_index].ex_entry = NULL;
+			l->ext_offset = 0;
+		}
+		partition_set_changed(cxt, partnum, 1);
+		clear_partition(p);
+	} else if (!q->sys_ind && partnum > 4) {
+		/* the last one in the chain - just delete */
+		--cxt->label->nparts_max;
+		--partnum;
+		clear_partition(l->ptes[partnum].ex_entry);
+		partition_set_changed(cxt, partnum, 1);
+	} else {
+		/* not the last one - further ones will be moved down */
+		if (partnum > 4) {
+			/* delete this link in the chain */
+			p = l->ptes[partnum - 1].ex_entry;
+			*p = *q;
+			dos_partition_set_start(p, dos_partition_get_start(q));
+			dos_partition_set_size(p, dos_partition_get_size(q));
+			partition_set_changed(cxt, partnum - 1, 1);
+		} else if (cxt->label->nparts_max > 5) {    /* 5 will be moved to 4 */
+			/* the first logical in a longer chain */
+			pe = &l->ptes[5];
+
+			if (pe->pt_entry) /* prevent SEGFAULT */
+				dos_partition_set_start(pe->pt_entry,
+					       get_abs_partition_start(pe) -
+					       l->ext_offset);
+			pe->offset = l->ext_offset;
+			partition_set_changed(cxt, 5, 1);
+		}
+
+		if (cxt->label->nparts_max > 5) {
+			cxt->label->nparts_max--;
+			while (partnum < cxt->label->nparts_max) {
+				l->ptes[partnum] = l->ptes[partnum + 1];
+				partnum++;
+			}
+		} else
+			/* the only logical: clear only */
+			clear_partition(l->ptes[partnum].pt_entry);
+	}
+
+	fdisk_label_set_changed(cxt->label, 1);
+	return 0;
+}
+
+static void read_extended(struct fdisk_context *cxt, int ext)
+{
+	size_t i;
+	struct pte *pex;
+	struct dos_partition *p, *q;
+	struct fdisk_dos_label *l = self_label(cxt);
+
+	l->ext_index = ext;
+	pex = self_pte(cxt, ext);
+	pex->ex_entry = pex->pt_entry;
+
+	p = pex->pt_entry;
+	if (!dos_partition_get_start(p)) {
+		fdisk_warnx(cxt, _("Bad offset in primary extended partition"));
+		return;
+	}
+
+	while (IS_EXTENDED (p->sys_ind)) {
+		struct pte *pe = self_pte(cxt, cxt->label->nparts_max);
+
+		if (cxt->label->nparts_max >= MAXIMUM_PARTS) {
+			/* This is not a Linux restriction, but
+			   this program uses arrays of size MAXIMUM_PARTS.
+			   Do not try to `improve' this test. */
+			struct pte *pre = self_pte(cxt,
+						cxt->label->nparts_max - 1);
+			fdisk_warnx(cxt,
+			_("Omitting partitions after #%zd. They will be deleted "
+			  "if you save this partition table."),
+				cxt->label->nparts_max);
+
+			clear_partition(pre->ex_entry);
+			partition_set_changed(cxt,
+					cxt->label->nparts_max - 1, 1);
+			return;
+		}
+
+		read_pte(cxt, cxt->label->nparts_max,
+			 l->ext_offset + dos_partition_get_start(p));
+
+		if (!l->ext_offset)
+			l->ext_offset = dos_partition_get_start(p);
+
+		q = p = mbr_get_partition(pe->sectorbuffer, 0);
+
+		for (i = 0; i < 4; i++, p++) if (dos_partition_get_size(p)) {
+			if (IS_EXTENDED (p->sys_ind)) {
+				if (pe->ex_entry)
+					fdisk_warnx(cxt, _(
+					"Extra link pointer in partition "
+					"table %zd"),
+						cxt->label->nparts_max + 1);
+				else
+					pe->ex_entry = p;
+			} else if (p->sys_ind) {
+				if (pe->pt_entry)
+					fdisk_warnx(cxt, _(
+					"Ignoring extra data in partition "
+					"table %zd"),
+						cxt->label->nparts_max + 1);
+				else
+					pe->pt_entry = p;
+			}
+		}
+
+		/* very strange code here... */
+		if (!pe->pt_entry) {
+			if (q != pe->ex_entry)
+				pe->pt_entry = q;
+			else
+				pe->pt_entry = q + 1;
+		}
+		if (!pe->ex_entry) {
+			if (q != pe->pt_entry)
+				pe->ex_entry = q;
+			else
+				pe->ex_entry = q + 1;
+		}
+
+		p = pe->ex_entry;
+		cxt->label->nparts_cur = ++cxt->label->nparts_max;
+	}
+
+	/* remove empty links */
+ remove:
+	q = self_partition(cxt, 4);
+	for (i = 4; i < cxt->label->nparts_max; i++) {
+		p = self_partition(cxt, i);
+
+		if (!dos_partition_get_size(p) &&
+		    (cxt->label->nparts_max > 5 || q->sys_ind)) {
+			fdisk_info(cxt, _("omitting empty partition (%zd)"), i+1);
+			dos_delete_partition(cxt, i);
+			goto remove; 	/* numbering changed */
+		}
+	}
+}
+
+static int dos_get_disklabel_id(struct fdisk_context *cxt, char **id)
+{
+	unsigned int num;
+
+	assert(cxt);
+	assert(id);
+	assert(cxt->label);
+	assert(fdisk_is_disklabel(cxt, DOS));
+
+	num = mbr_get_id(cxt->firstsector);
+	if (asprintf(id, "0x%08x", num) > 0)
+		return 0;
+
+	return -ENOMEM;
+}
+
+static int dos_create_disklabel(struct fdisk_context *cxt)
+{
+	unsigned int id;
+
+	assert(cxt);
+	assert(cxt->label);
+	assert(fdisk_is_disklabel(cxt, DOS));
+
+	/* random disk signature */
+	random_get_bytes(&id, sizeof(id));
+
+	fdisk_info(cxt, ("Building a new DOS disklabel with disk "
+			 "identifier 0x%08x."), id);
+
+	dos_init(cxt);
+	fdisk_zeroize_firstsector(cxt);
+	fdisk_label_set_changed(cxt->label, 1);
+
+	/* Generate an MBR ID for this disk */
+	mbr_set_id(cxt->firstsector, id);
+
+	/* Put MBR signature */
+	mbr_set_magic(cxt->firstsector);
+	return 0;
+}
+
+static int dos_set_disklabel_id(struct fdisk_context *cxt)
+{
+	char *end = NULL, *str = NULL;
+	unsigned int id, old;
+	struct fdisk_dos_label *l;
+	int rc;
+
+	assert(cxt);
+	assert(cxt->label);
+	assert(fdisk_is_disklabel(cxt, DOS));
+
+	l = self_label(cxt);
+	old = mbr_get_id(cxt->firstsector);
+	rc = fdisk_ask_string(cxt,
+			_("Enter of the new disk identifier"), &str);
+	if (rc)
+		return rc;
+
+	errno = 0;
+	id = strtoul(str, &end, 0);
+	if (errno || str == end || (end && *end)) {
+		fdisk_warnx(cxt, _("Incorrect value."));
+		return -EINVAL;
+	}
+
+	fdisk_info(cxt, _("Changing disk identifier from 0x%08x to 0x%08x."),
+			old, id);
+
+	mbr_set_id(cxt->firstsector, id);
+	l->non_pt_changed = 1;
+	fdisk_label_set_changed(cxt->label, 1);
+	return 0;
+}
+
+static void get_partition_table_geometry(struct fdisk_context *cxt,
+			unsigned int *ph, unsigned int *ps)
+{
+	unsigned char *bufp = cxt->firstsector;
+	struct dos_partition *p;
+	int i, h, s, hh, ss;
+	int first = 1;
+	int bad = 0;
+
+	hh = ss = 0;
+	for (i=0; i<4; i++) {
+		p = mbr_get_partition(bufp, i);
+		if (p->sys_ind != 0) {
+			h = p->eh + 1;
+			s = (p->es & 077);
+			if (first) {
+				hh = h;
+				ss = s;
+				first = 0;
+			} else if (hh != h || ss != s)
+				bad = 1;
+		}
+	}
+
+	if (!first && !bad) {
+		*ph = hh;
+		*ps = ss;
+	}
+
+	DBG(LABEL, dbgprint("DOS PT geometry: heads=%u, sectors=%u", *ph, *ps));
+}
+
+static int dos_reset_alignment(struct fdisk_context *cxt)
+{
+	assert(cxt);
+	assert(cxt->label);
+	assert(fdisk_is_disklabel(cxt, DOS));
+
+	/* overwrite necessary stuff by DOS deprecated stuff */
+	if (is_dos_compatible(cxt)) {
+		if (cxt->geom.sectors)
+			cxt->first_lba = cxt->geom.sectors;	/* usually 63 */
+
+		cxt->grain = cxt->sector_size;			/* usually 512 */
+	}
+
+	return 0;
+}
+
+/* TODO: move to include/pt-dos.h and share with libblkid */
+#define AIX_MAGIC_STRING	"\xC9\xC2\xD4\xC1"
+#define AIX_MAGIC_STRLEN	(sizeof(AIX_MAGIC_STRING) - 1)
+
+static int dos_probe_label(struct fdisk_context *cxt)
+{
+	size_t i;
+	unsigned int h = 0, s = 0;
+
+	assert(cxt);
+	assert(cxt->label);
+	assert(fdisk_is_disklabel(cxt, DOS));
+
+	/* ignore disks with AIX magic number */
+	if (memcmp(cxt->firstsector, AIX_MAGIC_STRING, AIX_MAGIC_STRLEN) == 0)
+		return 0;
+
+	if (!mbr_is_valid_magic(cxt->firstsector))
+		return 0;
+
+	dos_init(cxt);
+
+	get_partition_table_geometry(cxt, &h, &s);
+	if (h && s) {
+		cxt->geom.heads = h;
+	        cxt->geom.sectors = s;
+	}
+
+	for (i = 0; i < 4; i++) {
+		struct pte *pe = self_pte(cxt, i);
+
+		if (!is_cleared_partition(pe->pt_entry))
+			cxt->label->nparts_cur++;
+
+		if (IS_EXTENDED (pe->pt_entry->sys_ind)) {
+			if (cxt->label->nparts_max != 4)
+				fdisk_warnx(cxt, _(
+				"Ignoring extra extended partition %zd"),
+					i + 1);
+			else
+				read_extended(cxt, i);
+		}
+	}
+
+	for (i = 3; i < cxt->label->nparts_max; i++) {
+		struct pte *pe = self_pte(cxt, i);
+
+		if (!mbr_is_valid_magic(pe->sectorbuffer)) {
+			fdisk_info(cxt, _(
+			"Invalid flag 0x%02x%02x of partition table %zd will "
+			"be corrected by w(rite)"),
+				pe->sectorbuffer[510],
+				pe->sectorbuffer[511],
+				i + 1);
+			partition_set_changed(cxt, 1, 1);
+		}
+	}
+
+	return 1;
+}
+
+/*
+ * Avoid warning about DOS partitions when no DOS partition was changed.
+ * Here a heuristic "is probably dos partition".
+ * We might also do the opposite and warn in all cases except
+ * for "is probably nondos partition".
+ */
+static int is_dos_partition(int t)
+{
+	return (t == 1 || t == 4 || t == 6 ||
+		t == 0x0b || t == 0x0c || t == 0x0e ||
+		t == 0x11 || t == 0x12 || t == 0x14 || t == 0x16 ||
+		t == 0x1b || t == 0x1c || t == 0x1e || t == 0x24 ||
+		t == 0xc1 || t == 0xc4 || t == 0xc6);
+}
+
+static void set_partition(struct fdisk_context *cxt,
+			  int i, int doext, sector_t start,
+			  sector_t stop, int sysid)
+{
+	struct pte *pe = self_pte(cxt, i);
+	struct dos_partition *p;
+	sector_t offset;
+
+	if (doext) {
+		struct fdisk_dos_label *l = self_label(cxt);
+		p = pe->ex_entry;
+		offset = l->ext_offset;
+	} else {
+		p = pe->pt_entry;
+		offset = pe->offset;
+	}
+	p->boot_ind = 0;
+	p->sys_ind = sysid;
+	dos_partition_set_start(p, start - offset);
+	dos_partition_set_size(p, stop - start + 1);
+
+	if (!doext) {
+		struct fdisk_parttype *t = fdisk_get_parttype_from_code(cxt, sysid);
+		fdisk_info_new_partition(cxt, i + 1, start, stop, t);
+	}
+	if (is_dos_compatible(cxt) && (start/(cxt->geom.sectors*cxt->geom.heads) > 1023))
+		start = cxt->geom.heads*cxt->geom.sectors*1024 - 1;
+	set_hsc(p->bh, p->bs, p->bc, start);
+	if (is_dos_compatible(cxt) && (stop/(cxt->geom.sectors*cxt->geom.heads) > 1023))
+		stop = cxt->geom.heads*cxt->geom.sectors*1024 - 1;
+	set_hsc(p->eh, p->es, p->ec, stop);
+	partition_set_changed(cxt, i, 1);
+}
+
+static sector_t get_unused_start(struct fdisk_context *cxt,
+				 int part_n, sector_t start,
+				 sector_t first[], sector_t last[])
+{
+	size_t i;
+
+	for (i = 0; i < cxt->label->nparts_max; i++) {
+		sector_t lastplusoff;
+		struct pte *pe = self_pte(cxt, i);
+
+		if (start == pe->offset)
+			start += cxt->first_lba;
+		lastplusoff = last[i] + ((part_n < 4) ? 0 : cxt->first_lba);
+		if (start >= first[i] && start <= lastplusoff)
+			start = lastplusoff + 1;
+	}
+
+	return start;
+}
+
+static void fill_bounds(struct fdisk_context *cxt,
+			sector_t *first, sector_t *last)
+{
+	size_t i;
+	struct pte *pe = self_pte(cxt, 0);
+	struct dos_partition *p;
+
+	for (i = 0; i < cxt->label->nparts_max; pe++,i++) {
+		p = pe->pt_entry;
+		if (!p->sys_ind || IS_EXTENDED (p->sys_ind)) {
+			first[i] = 0xffffffff;
+			last[i] = 0;
+		} else {
+			first[i] = get_abs_partition_start(pe);
+			last[i] = first[i] + dos_partition_get_size(p) - 1;
+		}
+	}
+}
+
+static int add_partition(struct fdisk_context *cxt, int n, struct fdisk_parttype *t)
+{
+	int sys, read = 0, rc;
+	size_t i;
+	struct fdisk_dos_label *l = self_label(cxt);
+	struct dos_partition *p = self_partition(cxt, n);
+	struct dos_partition *q = self_partition(cxt, l->ext_index);
+
+	sector_t start, stop = 0, limit, temp,
+		first[cxt->label->nparts_max],
+		last[cxt->label->nparts_max];
+
+	sys = t ? t->type : MBR_LINUX_DATA_PARTITION;
+
+	if (p && p->sys_ind) {
+		fdisk_warnx(cxt, _("Partition %d is already defined.  Delete "
+			 "it before re-adding it."), n + 1);
+		return -EINVAL;
+	}
+	fill_bounds(cxt, first, last);
+	if (n < 4) {
+		start = cxt->first_lba;
+		if (fdisk_context_use_cylinders(cxt) || !cxt->total_sectors)
+			limit = cxt->geom.heads * cxt->geom.sectors * cxt->geom.cylinders - 1;
+		else
+			limit = cxt->total_sectors - 1;
+
+		if (limit > UINT_MAX)
+			limit = UINT_MAX;
+
+		if (l->ext_offset) {
+			first[l->ext_index] = l->ext_offset;
+			last[l->ext_index] = dos_partition_get_start(q) +
+				dos_partition_get_size(q) - 1;
+		}
+	} else {
+		start = l->ext_offset + cxt->first_lba;
+		limit = dos_partition_get_start(q)
+			+ dos_partition_get_size(q) - 1;
+	}
+	if (fdisk_context_use_cylinders(cxt))
+		for (i = 0; i < cxt->label->nparts_max; i++)
+			first[i] = (cround(cxt, first[i]) - 1)
+				* fdisk_context_get_units_per_sector(cxt);
+
+	/*
+	 * Ask for first sector
+	 */
+	do {
+		sector_t dflt, aligned;
+
+		temp = start;
+		dflt = start = get_unused_start(cxt, n, start, first, last);
+
+		/* the default sector should be aligned and unused */
+		do {
+			aligned = fdisk_align_lba_in_range(cxt, dflt, dflt, limit);
+			dflt = get_unused_start(cxt, n, aligned, first, last);
+		} while (dflt != aligned && dflt > aligned && dflt < limit);
+
+		if (dflt >= limit)
+			dflt = start;
+		if (start > limit)
+			break;
+		if (start >= temp + fdisk_context_get_units_per_sector(cxt)
+		    && read) {
+			fdisk_info(cxt, _("Sector %llu is already allocated"),
+					temp);
+			temp = start;
+			read = 0;
+		}
+
+		if (!read && start == temp) {
+			sector_t j = start;
+			struct fdisk_ask *ask = fdisk_new_ask();
+
+			if (fdisk_context_use_cylinders(cxt))
+				fdisk_ask_set_query(ask, _("First cylinder"));
+			else
+				fdisk_ask_set_query(ask, _("First sector"));
+
+			fdisk_ask_set_type(ask, FDISK_ASKTYPE_NUMBER);
+			fdisk_ask_number_set_low(ask, cround(cxt, j));
+			fdisk_ask_number_set_default(ask, cround(cxt, dflt));
+			fdisk_ask_number_set_high(ask, cround(cxt, limit));
+
+			rc = fdisk_do_ask(cxt, ask);
+			if (!rc)
+				start = fdisk_ask_number_get_result(ask);
+			fdisk_free_ask(ask);
+			if (rc)
+				return rc;
+
+			if (fdisk_context_use_cylinders(cxt)) {
+				start = (start - 1)
+					* fdisk_context_get_units_per_sector(cxt);
+				if (start < j)
+					start = j;
+			}
+			read = 1;
+		}
+	} while (start != temp || !read);
+
+	if (n > 4) {			/* NOT for fifth partition */
+		struct pte *pe = self_pte(cxt, n);
+
+		pe->offset = start - cxt->first_lba;
+		if (pe->offset == l->ext_offset) { /* must be corrected */
+			pe->offset++;
+			if (cxt->first_lba == 1)
+				start++;
+		}
+	}
+
+	for (i = 0; i < cxt->label->nparts_max; i++) {
+		struct pte *pe = self_pte(cxt, i);
+
+		if (start < pe->offset && limit >= pe->offset)
+			limit = pe->offset - 1;
+		if (start < first[i] && limit >= first[i])
+			limit = first[i] - 1;
+	}
+	if (start > limit) {
+		fdisk_info(cxt, _("No free sectors available"));
+		if (n > 4)
+			cxt->label->nparts_max--;
+		return -ENOSPC;
+	}
+	if (cround(cxt, start) == cround(cxt, limit)) {
+		stop = limit;
+	} else {
+		/*
+		 * Ask for last sector
+		 */
+		struct fdisk_ask *ask = fdisk_new_ask();
+
+		fdisk_ask_set_type(ask, FDISK_ASKTYPE_OFFSET);
+
+		if (fdisk_context_use_cylinders(cxt)) {
+			fdisk_ask_set_query(ask, _("Last cylinder, +cylinders or +size{K,M,G,T,P}"));
+			fdisk_ask_number_set_unit(ask,
+				     cxt->sector_size *
+				     fdisk_context_get_units_per_sector(cxt));
+		} else {
+			fdisk_ask_set_query(ask, _("Last sector, +sectors or +size{K,M,G,T,P}"));
+			fdisk_ask_number_set_unit(ask,cxt->sector_size);
+		}
+
+		fdisk_ask_number_set_low(ask, cround(cxt, start));
+		fdisk_ask_number_set_default(ask, cround(cxt, limit));
+		fdisk_ask_number_set_high(ask, cround(cxt, limit));
+		fdisk_ask_number_set_base(ask, cround(cxt, start));	/* base for relative input */
+
+		rc = fdisk_do_ask(cxt, ask);
+		if (rc) {
+			fdisk_free_ask(ask);
+			return rc;
+		}
+
+		stop = fdisk_ask_number_get_result(ask);
+
+		if (fdisk_ask_number_is_relative(ask)
+		    && alignment_required(cxt)) {
+			/* the last sector has not been exactly requested (but
+			 * defined by +size{K,M,G} convention), so be smart and
+			 * align the end of the partition. The next partition
+			 * will start at phy.block boundary.
+			 */
+			stop = fdisk_align_lba_in_range(cxt, stop, start, limit) - 1;
+			if (stop > limit)
+				stop = limit;
+		}
+		fdisk_free_ask(ask);
+	}
+
+	set_partition(cxt, n, 0, start, stop, sys);
+	if (n > 4) {
+		struct pte *pe = self_pte(cxt, n);
+		set_partition(cxt, n - 1, 1, pe->offset, stop,
+				MBR_DOS_EXTENDED_PARTITION);
+	}
+
+	if (IS_EXTENDED(sys)) {
+		struct pte *pe4 = self_pte(cxt, 4);
+		struct pte *pen = self_pte(cxt, n);
+
+		l->ext_index = n;
+		pen->ex_entry = p;
+		pe4->offset = l->ext_offset = start;
+		pe4->sectorbuffer = calloc(1, cxt->sector_size);
+		if (!pe4->sectorbuffer)
+			return -ENOMEM;
+		pe4->private_sectorbuffer = 1;
+		pe4->pt_entry = mbr_get_partition(pe4->sectorbuffer, 0);
+		pe4->ex_entry = pe4->pt_entry + 1;
+
+		partition_set_changed(cxt, 4, 1);
+		cxt->label->nparts_max = 5;
+	}
+
+	fdisk_label_set_changed(cxt->label, 1);
+	return 0;
+}
+
+static int add_logical(struct fdisk_context *cxt)
+{
+	struct dos_partition *p4 = self_partition(cxt, 4);
+
+	assert(cxt);
+	assert(cxt->label);
+
+	if (cxt->label->nparts_max > 5 || p4->sys_ind) {
+		struct pte *pe = self_pte(cxt, cxt->label->nparts_max);
+
+		pe->sectorbuffer = calloc(1, cxt->sector_size);
+		if (!pe->sectorbuffer)
+			return -ENOMEM;
+		pe->private_sectorbuffer = 1;
+		pe->pt_entry = mbr_get_partition(pe->sectorbuffer, 0);
+		pe->ex_entry = pe->pt_entry + 1;
+		pe->offset = 0;
+
+		partition_set_changed(cxt, cxt->label->nparts_max, 1);
+		cxt->label->nparts_max++;
+	}
+	fdisk_info(cxt, _("Adding logical partition %zd"),
+			cxt->label->nparts_max);
+	return add_partition(cxt, cxt->label->nparts_max - 1, NULL);
+}
+
+static void check(struct fdisk_context *cxt, size_t n,
+	   unsigned int h, unsigned int s, unsigned int c,
+	   unsigned int start)
+{
+	unsigned int total, real_s, real_c;
+
+	real_s = sector(s) - 1;
+	real_c = cylinder(s, c);
+	total = (real_c * cxt->geom.sectors + real_s) * cxt->geom.heads + h;
+
+	if (!total)
+		fdisk_warnx(cxt, _("Partition %zd: contains sector 0"), n);
+	if (h >= cxt->geom.heads)
+		fdisk_warnx(cxt, _("Partition %zd: head %d greater than "
+				   "maximum %d"), n, h + 1, cxt->geom.heads);
+	if (real_s >= cxt->geom.sectors)
+		fdisk_warnx(cxt, _("Partition %zd: sector %d greater than "
+				   "maximum %llu"), n, s, cxt->geom.sectors);
+	if (real_c >= cxt->geom.cylinders)
+		fdisk_warnx(cxt, _("Partition %zd: cylinder %d greater than "
+				   "maximum %llu"),
+				n, real_c + 1,
+				cxt->geom.cylinders);
+
+	if (cxt->geom.cylinders <= 1024 && start != total)
+		fdisk_warnx(cxt, _("Partition %zd: previous sectors %d "
+				   "disagrees with total %d"), n, start, total);
+}
+
+/* check_consistency() and long2chs() added Sat Mar 6 12:28:16 1993,
+ * faith@cs.unc.edu, based on code fragments from pfdisk by Gordon W. Ross,
+ * Jan.  1990 (version 1.2.1 by Gordon W. Ross Aug. 1990; Modified by S.
+ * Lubkin Oct.  1991). */
+
+static void
+long2chs(struct fdisk_context *cxt, unsigned long ls,
+	 unsigned int *c, unsigned int *h, unsigned int *s) {
+	int spc = cxt->geom.heads * cxt->geom.sectors;
+
+	*c = ls / spc;
+	ls = ls % spc;
+	*h = ls / cxt->geom.sectors;
+	*s = ls % cxt->geom.sectors + 1;	/* sectors count from 1 */
+}
+
+static void check_consistency(struct fdisk_context *cxt, struct dos_partition *p,
+			      size_t partition)
+{
+	unsigned int pbc, pbh, pbs;	/* physical beginning c, h, s */
+	unsigned int pec, peh, pes;	/* physical ending c, h, s */
+	unsigned int lbc, lbh, lbs;	/* logical beginning c, h, s */
+	unsigned int lec, leh, les;	/* logical ending c, h, s */
+
+	if (!is_dos_compatible(cxt))
+		return;
+
+	if (!cxt->geom.heads || !cxt->geom.sectors || (partition >= 4))
+		return;		/* do not check extended partitions */
+
+/* physical beginning c, h, s */
+	pbc = (p->bc & 0xff) | ((p->bs << 2) & 0x300);
+	pbh = p->bh;
+	pbs = p->bs & 0x3f;
+
+/* physical ending c, h, s */
+	pec = (p->ec & 0xff) | ((p->es << 2) & 0x300);
+	peh = p->eh;
+	pes = p->es & 0x3f;
+
+/* compute logical beginning (c, h, s) */
+	long2chs(cxt, dos_partition_get_start(p), &lbc, &lbh, &lbs);
+
+/* compute logical ending (c, h, s) */
+	long2chs(cxt, dos_partition_get_start(p) + dos_partition_get_size(p) - 1, &lec, &leh, &les);
+
+/* Same physical / logical beginning? */
+	if (cxt->geom.cylinders <= 1024
+	    && (pbc != lbc || pbh != lbh || pbs != lbs)) {
+		fdisk_warnx(cxt, _("Partition %zd: different physical/logical "
+			"beginnings (non-Linux?): "
+			"phys=(%d, %d, %d), logical=(%d, %d, %d)"),
+			partition + 1,
+			pbc, pbh, pbs,
+			lbc, lbh, lbs);
+	}
+
+/* Same physical / logical ending? */
+	if (cxt->geom.cylinders <= 1024
+	    && (pec != lec || peh != leh || pes != les)) {
+		fdisk_warnx(cxt, _("Partition %zd: different physical/logical "
+			"endings: phys=(%d, %d, %d), logical=(%d, %d, %d)"),
+			partition + 1,
+			pec, peh, pes,
+			lec, leh, les);
+	}
+
+/* Ending on cylinder boundary? */
+	if (peh != (cxt->geom.heads - 1) || pes != cxt->geom.sectors) {
+		fdisk_warnx(cxt, _("Partition %zd: does not end on "
+				   "cylinder boundary."),
+			partition + 1);
+	}
+}
+
+static int dos_verify_disklabel(struct fdisk_context *cxt)
+{
+	size_t i, j;
+	sector_t total = 1, n_sectors = cxt->total_sectors;
+	unsigned long long first[cxt->label->nparts_max],
+			   last[cxt->label->nparts_max];
+	struct dos_partition *p;
+	struct fdisk_dos_label *l = self_label(cxt);
+
+	assert(fdisk_is_disklabel(cxt, DOS));
+
+	fill_bounds(cxt, first, last);
+	for (i = 0; i < cxt->label->nparts_max; i++) {
+		struct pte *pe = self_pte(cxt, i);
+
+		p = self_partition(cxt, i);
+		if (p->sys_ind && !IS_EXTENDED(p->sys_ind)) {
+			check_consistency(cxt, p, i);
+			fdisk_warn_alignment(cxt, get_abs_partition_start(pe), i);
+			if (get_abs_partition_start(pe) < first[i])
+				fdisk_warnx(cxt, _(
+					"Partition %zd: bad start-of-data."),
+					 i + 1);
+
+			check(cxt, i + 1, p->eh, p->es, p->ec, last[i]);
+			total += last[i] + 1 - first[i];
+
+			for (j = 0; j < i; j++) {
+				if ((first[i] >= first[j] && first[i] <= last[j])
+				    || ((last[i] <= last[j] && last[i] >= first[j]))) {
+
+					fdisk_warnx(cxt, _("Partition %zd: "
+						"overlaps partition %zd."),
+						j + 1, i + 1);
+
+					total += first[i] >= first[j] ?
+						first[i] : first[j];
+					total -= last[i] <= last[j] ?
+						last[i] : last[j];
+				}
+			}
+		}
+	}
+
+	if (l->ext_offset) {
+		p = self_partition(cxt, l->ext_index);
+
+		sector_t e_last = dos_partition_get_start(p)
+				  + dos_partition_get_size(p) - 1;
+
+		for (i = 4; i < cxt->label->nparts_max; i++) {
+			total++;
+			p = self_partition(cxt, i);
+
+			if (!p->sys_ind) {
+				if (i != 4 || i + 1 < cxt->label->nparts_max)
+					fdisk_warnx(cxt,
+						_("Partition %zd: empty"),
+						i + 1);
+			} else if (first[i] < l->ext_offset
+				   || last[i] > e_last) {
+
+				fdisk_warnx(cxt, _("Logical partition %zd: "
+					"not entirely in partition %zd"),
+					i + 1, l->ext_index + 1);
+			}
+		}
+	}
+
+	if (total > n_sectors)
+		fdisk_warnx(cxt, _("Total allocated sectors %llu greater "
+			"than the maximum %llu."), total, n_sectors);
+	else if (total < n_sectors)
+		fdisk_warnx(cxt, _("Remaining %lld unallocated %ld-byte "
+			"sectors"), n_sectors - total, cxt->sector_size);
+
+	return 0;
+}
+
+/*
+ * Ask the user for new partition type information (logical, extended).
+ * This function calls the actual partition adding logic - add_partition.
+ *
+ * API callback.
+ */
+static int dos_add_partition(
+			struct fdisk_context *cxt,
+			size_t partnum __attribute__ ((__unused__)),
+			struct fdisk_parttype *t)
+{
+	size_t i, free_primary = 0;
+	int rc = 0;
+	struct fdisk_dos_label *l = self_label(cxt);
+
+	assert(cxt);
+	assert(cxt->label);
+	assert(fdisk_is_disklabel(cxt, DOS));
+
+	for (i = 0; i < 4; i++) {
+		struct dos_partition *p = self_partition(cxt, i);
+		free_primary += !p->sys_ind;
+	}
+
+	if (!free_primary && cxt->label->nparts_max >= MAXIMUM_PARTS) {
+		fdisk_info(cxt, _("The maximum number of partitions has "
+				  "been created."));
+		return -EINVAL;
+	}
+	rc = 1;
+
+	if (!free_primary) {
+		if (l->ext_offset) {
+			fdisk_info(cxt, _("All primary partitions are in use."));
+			rc = add_logical(cxt);
+		} else
+			fdisk_info(cxt, _("If you want to create more than "
+				"four partitions, you must replace a"
+				"primary partition with an extended "
+				"partition first."));
+
+	} else if (cxt->label->nparts_max >= MAXIMUM_PARTS) {
+		int j;
+
+		fdisk_info(cxt, _("All logical partitions are in use. "
+				  "Adding a primary partition."));
+		j = get_partition_unused_primary(cxt);
+		if (j >= 0)
+			rc = add_partition(cxt, j, t);
+	} else {
+		char *buf;
+		char c, prompt[BUFSIZ];
+		int dflt;
+
+		dflt = (free_primary == 1 && !l->ext_offset) ? 'e' : 'p';
+
+		snprintf(prompt, sizeof(prompt),
+			 _("Partition type:\n"
+			   "   p   primary (%zd primary, %d extended, %zd free)\n"
+			   "%s\n"
+			   "Select (default %c)"),
+			 4 - (l->ext_offset ? 1 : 0) - free_primary,
+			 l->ext_offset ? 1 : 0, free_primary,
+			 l->ext_offset ? _("   l   logical (numbered from 5)") : _("   e   extended"),
+			 dflt);
+
+		rc = fdisk_ask_string(cxt, prompt, &buf);
+		if (rc)
+			return rc;
+		if (!buf[0]) {
+			c = dflt;
+			fdisk_info(cxt, _("Using default response %c"), c);
+		} else
+			c = tolower(buf[0]);
+		free(buf);
+
+		if (c == 'p') {
+			int j = get_partition_unused_primary(cxt);
+			if (j >= 0)
+				rc = add_partition(cxt, j, t);
+			goto done;
+		} else if (c == 'l' && l->ext_offset) {
+			rc = add_logical(cxt);
+			goto done;
+		} else if (c == 'e' && !l->ext_offset) {
+			int j = get_partition_unused_primary(cxt);
+			if (j >= 0) {
+				t = fdisk_get_parttype_from_code(cxt,
+						MBR_DOS_EXTENDED_PARTITION);
+				rc = add_partition(cxt, j, t);
+			}
+			goto done;
+		} else
+			fdisk_warnx(cxt, _("Invalid partition type `%c'"), c);
+	}
+done:
+	if (rc == 0)
+		cxt->label->nparts_cur++;
+	return rc;
+}
+
+static int write_sector(struct fdisk_context *cxt, sector_t secno,
+			       unsigned char *buf)
+{
+	int rc;
+
+	rc = seek_sector(cxt, secno);
+	if (rc != 0) {
+		fdisk_warn(cxt, _("Write sector %jd failed: seek failed"),
+				(uintmax_t) secno);
+		return rc;
+	}
+	if (write(cxt->dev_fd, buf, cxt->sector_size) != (ssize_t) cxt->sector_size)
+		return -errno;
+	return 0;
+}
+
+static int dos_write_disklabel(struct fdisk_context *cxt)
+{
+	struct fdisk_dos_label *l = self_label(cxt);
+	size_t i;
+	int rc = 0, mbr_changed = 0;
+
+	assert(cxt);
+	assert(cxt->label);
+	assert(fdisk_is_disklabel(cxt, DOS));
+
+	mbr_changed = l->non_pt_changed;
+
+	/* MBR (primary partitions) */
+	if (!mbr_changed) {
+		for (i = 0; i < 4; i++) {
+			struct pte *pe = self_pte(cxt, i);
+			if (pe->changed)
+				mbr_changed = 1;
+		}
+	}
+	if (mbr_changed) {
+		mbr_set_magic(cxt->firstsector);
+		rc = write_sector(cxt, 0, cxt->firstsector);
+		if (rc)
+			goto done;
+	}
+
+	/* EBR (logical partitions) */
+	for (i = 4; i < cxt->label->nparts_max; i++) {
+		struct pte *pe = self_pte(cxt, i);
+
+		if (pe->changed) {
+			mbr_set_magic(pe->sectorbuffer);
+			rc = write_sector(cxt, pe->offset, pe->sectorbuffer);
+			if (rc)
+				goto done;
+		}
+	}
+
+done:
+	return rc;
+}
+
+static struct fdisk_parttype *dos_get_parttype(
+		struct fdisk_context *cxt,
+		size_t partnum)
+{
+	struct fdisk_parttype *t;
+	struct dos_partition *p;
+
+	assert(cxt);
+	assert(cxt->label);
+	assert(fdisk_is_disklabel(cxt, DOS));
+
+	if (partnum >= cxt->label->nparts_max)
+		return NULL;
+
+	p = self_partition(cxt, partnum);
+	t = fdisk_get_parttype_from_code(cxt, p->sys_ind);
+	if (!t)
+		t = fdisk_new_unknown_parttype(p->sys_ind, NULL);
+	return t;
+}
+
+static int dos_set_parttype(
+		struct fdisk_context *cxt,
+		size_t partnum,
+		struct fdisk_parttype *t)
+{
+	struct dos_partition *p;
+
+	assert(cxt);
+	assert(cxt->label);
+	assert(fdisk_is_disklabel(cxt, DOS));
+
+	if (partnum >= cxt->label->nparts_max || !t || t->type > UINT8_MAX)
+		return -EINVAL;
+
+	p = self_partition(cxt, partnum);
+	if (t->type == p->sys_ind)
+		return 0;
+
+	if (IS_EXTENDED(p->sys_ind) || IS_EXTENDED(t->type)) {
+		fdisk_warnx(cxt, _("You cannot change a partition into an "
+			"extended one or vice versa. Delete it first."));
+		return -EINVAL;
+	}
+
+	if (is_dos_partition(t->type) || is_dos_partition(p->sys_ind))
+	    fdisk_info(cxt, _("If you have created or modified any DOS 6.x "
+		"partitions, please see the fdisk documantation for additional "
+		"information."));
+
+	p->sys_ind = t->type;
+
+	partition_set_changed(cxt, partnum, 1);
+	return 0;
+}
+
+/*
+ * Check whether partition entries are ordered by their starting positions.
+ * Return 0 if OK. Return i if partition i should have been earlier.
+ * Two separate checks: primary and logical partitions.
+ */
+static int wrong_p_order(struct fdisk_context *cxt, size_t *prev)
+{
+	size_t last_p_start_pos = 0, p_start_pos;
+	size_t i, last_i = 0;
+
+	for (i = 0 ; i < cxt->label->nparts_max; i++) {
+
+		struct pte *pe = self_pte(cxt, i);
+		struct dos_partition *p = pe->pt_entry;
+
+		if (i == 4) {
+			last_i = 4;
+			last_p_start_pos = 0;
+		}
+		if (p->sys_ind) {
+			p_start_pos = get_abs_partition_start(pe);
+
+			if (last_p_start_pos > p_start_pos) {
+				if (prev)
+					*prev = last_i;
+				return i;
+			}
+
+			last_p_start_pos = p_start_pos;
+			last_i = i;
+		}
+	}
+	return 0;
+}
+
+static int is_garbage_table(struct fdisk_context *cxt)
+{
+	size_t i;
+
+	for (i = 0; i < 4; i++) {
+		struct dos_partition *p = self_partition(cxt, i);
+
+		if (p->boot_ind != 0 && p->boot_ind != 0x80)
+			return 1;
+	}
+	return 0;
+}
+
+/*
+ * List all PT fields.
+ *
+ * This is useful for PT debugging (or for 70's Hippies
+ * who are on permanent LSD trip).
+ */
+static int dos_fulllist_disklabel(struct fdisk_context *cxt, int ext)
+{
+	int rc;
+	size_t i;
+	struct tt *tb = NULL;
+
+	assert(cxt);
+	assert(cxt->label);
+	assert(fdisk_is_disklabel(cxt, DOS));
+
+	tb = tt_new_table(TT_FL_FREEDATA);
+	if (!tb)
+		return -ENOMEM;
+
+	tt_define_column(tb, _("Nr"), 2, TT_FL_RIGHT);
+	tt_define_column(tb, _("AF"), 2, TT_FL_RIGHT);
+
+	tt_define_column(tb, _("Hd"),  4, TT_FL_RIGHT);
+	tt_define_column(tb, _("Sec"), 4, TT_FL_RIGHT);
+	tt_define_column(tb, _("Cyl"), 5, TT_FL_RIGHT);
+
+	tt_define_column(tb, _("Hd"),  4, TT_FL_RIGHT);
+	tt_define_column(tb, _("Sec"), 4, TT_FL_RIGHT);
+	tt_define_column(tb, _("Cyl"), 5, TT_FL_RIGHT);
+
+	tt_define_column(tb, _("Start"), 9, TT_FL_RIGHT);
+	tt_define_column(tb, _("Size"),  9, TT_FL_RIGHT);
+	tt_define_column(tb, _("Id"),    2, TT_FL_RIGHT);
+
+	for (i = 0 ; i < cxt->label->nparts_max; i++) {
+		struct pte *pe = self_pte(cxt, i);
+		struct dos_partition *p;
+		struct tt_line *ln;
+		char *str;
+
+		p = ext ? pe->ex_entry : pe->pt_entry;
+		if (!p)
+			continue;
+		ln = tt_add_line(tb, NULL);
+		if (!ln)
+			continue;
+
+		if (asprintf(&str, "%zd",  i + 1) > 0)
+			tt_line_set_data(ln, 0, str);		/* Nr */
+		if (asprintf(&str, "%02x", p->boot_ind) > 0)
+			tt_line_set_data(ln, 1, str);		/* AF */
+
+		if (asprintf(&str, "%d", p->bh) > 0)
+			tt_line_set_data(ln, 2, str);		/* Hd */
+		if (asprintf(&str, "%d", sector(p->bs)) > 0)
+			tt_line_set_data(ln, 3, str);		/* Sec */
+		if (asprintf(&str, "%d", cylinder(p->bs, p->bc)) > 0)
+			tt_line_set_data(ln, 4, str);		/* Cyl */
+
+		if (asprintf(&str, "%d", p->eh) > 0)
+			tt_line_set_data(ln, 5, str);		/* Hd */
+		if (asprintf(&str, "%d", sector(p->es)) > 0)
+			tt_line_set_data(ln, 6, str);		/* Sec */
+		if (asprintf(&str, "%d", cylinder(p->es, p->ec)) > 0)
+			tt_line_set_data(ln, 7, str);		/* Cyl */
+
+		if (asprintf(&str, "%lu",
+			(unsigned long) dos_partition_get_start(p)) > 0)
+			tt_line_set_data(ln, 8, str);		/* Start */
+		if (asprintf(&str, "%lu",
+			(unsigned long) dos_partition_get_size(p)) > 0)
+			tt_line_set_data(ln, 9, str);		/* End */
+
+		if (asprintf(&str, "%02x", p->sys_ind) > 0)
+			tt_line_set_data(ln, 10, str);		/* Id */
+
+		if (p->sys_ind) {
+			check_consistency(cxt, p, i);
+			fdisk_warn_alignment(cxt,
+					get_abs_partition_start(pe), i);
+		}
+	}
+
+	rc = fdisk_print_table(cxt, tb);
+	tt_free_table(tb);
+
+	return rc;
+}
+
+int fdisk_dos_list_extended(struct fdisk_context *cxt)
+{
+	return dos_fulllist_disklabel(cxt, 1);
+}
+
+static int dos_list_disklabel(struct fdisk_context *cxt)
+{
+	int rc = 0, trunc = TT_FL_TRUNC;
+	size_t i;
+	struct tt *tb = NULL;
+
+	assert(cxt);
+	assert(cxt->label);
+	assert(fdisk_is_disklabel(cxt, DOS));
+
+	if (is_garbage_table(cxt)) {
+		fdisk_warnx(cxt, _(
+			"This doesn't look like a partition table "
+			"Probably you selected the wrong device."));
+	}
+
+	if (fdisk_context_display_details(cxt))
+		return dos_fulllist_disklabel(cxt, 0);
+
+	tb = tt_new_table(TT_FL_FREEDATA);
+	if (!tb)
+		return -ENOMEM;
+
+	/* don't trunc anything in expert mode */
+	if (fdisk_context_display_details(cxt))
+		trunc = 0;
+
+	tt_define_column(tb, _("Device"), 0.1, 0);
+	tt_define_column(tb, _("Boot"),     1, 0);
+	tt_define_column(tb, _("Start"),    9, TT_FL_RIGHT);
+	tt_define_column(tb, _("End"),      9, TT_FL_RIGHT);
+	/* TRANSLATORS: keep one blank space behind 'Blocks' */
+	tt_define_column(tb, _("Blocks "),  5, TT_FL_RIGHT);
+	tt_define_column(tb, _("Id"),       2, TT_FL_RIGHT);
+	tt_define_column(tb, _("System"), 0.1, trunc);
+
+	for (i = 0; i < cxt->label->nparts_max; i++) {
+		struct pte *pe = self_pte(cxt, i);
+		struct dos_partition *p = pe->pt_entry;
+		unsigned int psects, pblocks, podd = 0;;
+		struct fdisk_parttype *type;
+		struct tt_line *ln;
+		char *str;
+
+		if (!p || is_cleared_partition(p))
+			continue;
+		ln = tt_add_line(tb, NULL);
+		if (!ln)
+			continue;
+
+		pblocks = psects = dos_partition_get_size(p);
+		type = fdisk_get_parttype_from_code(cxt, p->sys_ind);
+
+		if (cxt->sector_size < 1024) {
+			pblocks /= (1024 / cxt->sector_size);
+			podd = psects % (1024 / cxt->sector_size);
+		}
+		if (cxt->sector_size > 1024)
+			pblocks *= (cxt->sector_size / 1024);
+
+		str = fdisk_partname(cxt->dev_path, i + 1);
+		if (str)
+			tt_line_set_data(ln, 0, str);		/* device */
+
+		str = strdup(p->boot_ind ?
+			     p->boot_ind == ACTIVE_FLAG ? "*" : "?" : " ");
+		if (str)
+			tt_line_set_data(ln, 1,	str);		/* boot flag */
+
+		if (asprintf(&str, "%lu", (unsigned long) cround(cxt,
+					get_abs_partition_start(pe))) > 0)
+			tt_line_set_data(ln, 2, str);		/* start */
+
+		if (asprintf(&str, "%lu", (unsigned long) cround(cxt,
+				get_abs_partition_start(pe)
+				+ psects - (psects ? 1 : 0))) > 0)
+			tt_line_set_data(ln, 3, str);		/* end */
+
+		if (asprintf(&str, "%lu%c", (unsigned long) pblocks,
+				podd ? '+' : ' ') > 0)
+			tt_line_set_data(ln, 4, str);		/* blocks<flag> */
+
+		if (asprintf(&str, "%x",  p->sys_ind) > 0)
+			tt_line_set_data(ln, 5, str);		/* id */
+
+		str = strdup(type ? type->name : _("Unknown"));
+		if (str)
+			tt_line_set_data(ln, 6, str);
+
+		check_consistency(cxt, p, i);
+		fdisk_warn_alignment(cxt, get_abs_partition_start(pe), i);
+		fdisk_free_parttype(type);
+	}
+
+	rc = fdisk_print_table(cxt, tb);
+	tt_free_table(tb);
+
+	/* Is partition table in disk order? It need not be, but... */
+	/* partition table entries are not checked for correct order if this
+	   is a sgi, sun labeled disk... */
+	if (wrong_p_order(cxt, NULL))
+		fdisk_info(cxt, _("Partition table entries are not in "
+				  "disk order."));
+
+	return rc;
+}
+
+
+/*
+ * Fix the chain of logicals.
+ * ext_offset is unchanged, the set of sectors used is unchanged
+ * The chain is sorted so that sectors increase, and so that
+ * starting sectors increase.
+ *
+ * After this it may still be that cfdisk doesn't like the table.
+ * (This is because cfdisk considers expanded parts, from link to
+ * end of partition, and these may still overlap.)
+ * Now
+ *   sfdisk /dev/hda > ohda; sfdisk /dev/hda < ohda
+ * may help.
+ */
+static void fix_chain_of_logicals(struct fdisk_context *cxt)
+{
+	struct fdisk_dos_label *l = self_label(cxt);
+	size_t j, oj, ojj, sj, sjj;
+	struct dos_partition *pj,*pjj,tmp;
+
+	/* Stage 1: sort sectors but leave sector of part 4 */
+	/* (Its sector is the global ext_offset.) */
+ stage1:
+	for (j = 5; j < cxt->label->nparts_max - 1; j++) {
+		oj = l->ptes[j].offset;
+		ojj = l->ptes[j + 1].offset;
+		if (oj > ojj) {
+			l->ptes[j].offset = ojj;
+			l->ptes[j + 1].offset = oj;
+			pj = l->ptes[j].pt_entry;
+			dos_partition_set_start(pj, dos_partition_get_start(pj)+oj-ojj);
+			pjj = l->ptes[j + 1].pt_entry;
+			dos_partition_set_start(pjj, dos_partition_get_start(pjj)+ojj-oj);
+			dos_partition_set_start(l->ptes[j - 1].ex_entry,
+				       ojj - l->ext_offset);
+			dos_partition_set_start(l->ptes[j].ex_entry,
+				       oj - l->ext_offset);
+			goto stage1;
+		}
+	}
+
+	/* Stage 2: sort starting sectors */
+ stage2:
+	for (j = 4; j < cxt->label->nparts_max - 1; j++) {
+		pj = l->ptes[j].pt_entry;
+		pjj = l->ptes[j + 1].pt_entry;
+		sj = dos_partition_get_start(pj);
+		sjj = dos_partition_get_start(pjj);
+		oj = l->ptes[j].offset;
+		ojj = l->ptes[j+1].offset;
+		if (oj+sj > ojj+sjj) {
+			tmp = *pj;
+			*pj = *pjj;
+			*pjj = tmp;
+			dos_partition_set_start(pj, ojj+sjj-oj);
+			dos_partition_set_start(pjj, oj+sj-ojj);
+			goto stage2;
+		}
+	}
+
+	/* Probably something was changed */
+	for (j = 4; j < cxt->label->nparts_max; j++)
+		l->ptes[j].changed = 1;
+}
+
+int fdisk_dos_fix_order(struct fdisk_context *cxt)
+{
+	struct pte *pei, *pek;
+	size_t i,k;
+
+	if (!wrong_p_order(cxt, NULL)) {
+		fdisk_info(cxt, _("Nothing to do. Ordering is correct already."));
+		return 0;
+	}
+
+	while ((i = wrong_p_order(cxt, &k)) != 0 && i < 4) {
+		/* partition i should have come earlier, move it */
+		/* We have to move data in the MBR */
+		struct dos_partition *pi, *pk, *pe, pbuf;
+		pei = self_pte(cxt, i);
+		pek = self_pte(cxt, k);
+
+		pe = pei->ex_entry;
+		pei->ex_entry = pek->ex_entry;
+		pek->ex_entry = pe;
+
+		pi = pei->pt_entry;
+		pk = pek->pt_entry;
+
+		memmove(&pbuf, pi, sizeof(struct dos_partition));
+		memmove(pi, pk, sizeof(struct dos_partition));
+		memmove(pk, &pbuf, sizeof(struct dos_partition));
+
+		partition_set_changed(cxt, i, 1);
+		partition_set_changed(cxt, k, 1);
+	}
+
+	if (i)
+		fix_chain_of_logicals(cxt);
+
+	fdisk_info(cxt, _("Done."));
+	return 0;
+}
+
+int fdisk_dos_move_begin(struct fdisk_context *cxt, int i)
+{
+	struct pte *pe;
+	struct dos_partition *p;
+	unsigned int new, free_start, curr_start, last;
+	uintmax_t res = 0;
+	size_t x;
+	int rc;
+
+	assert(cxt);
+	assert(fdisk_is_disklabel(cxt, DOS));
+
+	pe = self_pte(cxt, i);
+	p = pe->pt_entry;
+
+	if (!p->sys_ind || !dos_partition_get_size(p) || IS_EXTENDED (p->sys_ind)) {
+		fdisk_warn(cxt, _("Partition %d: no data area."), i + 1);
+		return 0;
+	}
+
+	/* the default start is at the second sector of the disk or at the
+	 * second sector of the extended partition
+	 */
+	free_start = pe->offset ? pe->offset + 1 : 1;
+
+	curr_start = get_abs_partition_start(pe);
+
+	/* look for a free space before the current start of the partition */
+	for (x = 0; x < cxt->label->nparts_max; x++) {
+		unsigned int end;
+		struct pte *prev_pe = self_pte(cxt, x);
+		struct dos_partition *prev_p = prev_pe->pt_entry;
+
+		if (!prev_p)
+			continue;
+		end = get_abs_partition_start(prev_pe)
+		      + dos_partition_get_size(prev_p);
+
+		if (!is_cleared_partition(prev_p) &&
+		    end > free_start && end <= curr_start)
+			free_start = end;
+	}
+
+	last = get_abs_partition_start(pe) + dos_partition_get_size(p) - 1;
+
+	rc = fdisk_ask_number(cxt, free_start, curr_start, last,
+			_("New beginning of data"), &res);
+	if (rc)
+		return rc;
+
+	new = res - pe->offset;
+
+	if (new != dos_partition_get_size(p)) {
+		unsigned int sects = dos_partition_get_size(p)
+				+ dos_partition_get_start(p) - new;
+
+		dos_partition_set_size(p, sects);
+		dos_partition_set_start(p, new);
+
+		partition_set_changed(cxt, i, 1);
+	}
+
+	return rc;
+}
+
+static int dos_get_partition_status(
+		struct fdisk_context *cxt,
+		size_t i,
+		int *status)
+{
+	struct dos_partition *p;
+
+	assert(cxt);
+	assert(cxt->label);
+	assert(fdisk_is_disklabel(cxt, DOS));
+
+	if (!status || i >= cxt->label->nparts_max)
+		return -EINVAL;
+
+	p = self_partition(cxt, i);
+
+	if (p && !is_cleared_partition(p))
+		*status = FDISK_PARTSTAT_USED;
+	else
+		*status = FDISK_PARTSTAT_NONE;
+
+	return 0;
+}
+
+static int dos_toggle_partition_flag(
+		struct fdisk_context *cxt,
+		size_t i,
+		unsigned long flag)
+{
+	struct dos_partition *p;
+
+	assert(cxt);
+	assert(cxt->label);
+	assert(fdisk_is_disklabel(cxt, DOS));
+
+	if (i >= cxt->label->nparts_max)
+		return -EINVAL;
+
+	p = self_partition(cxt, i);
+
+	switch (flag) {
+	case DOS_FLAG_ACTIVE:
+		if (IS_EXTENDED(p->sys_ind) && !p->boot_ind)
+			fdisk_warnx(cxt, _("Partition %d: is an extended "
+					"partition."), i + 1);
+
+		p->boot_ind = (p->boot_ind ? 0 : ACTIVE_FLAG);
+		partition_set_changed(cxt, i, 1);
+		break;
+	default:
+		return 1;
+	}
+
+	return 0;
+}
+
+static const struct fdisk_label_operations dos_operations =
+{
+	.probe		= dos_probe_label,
+	.write		= dos_write_disklabel,
+	.verify		= dos_verify_disklabel,
+	.create		= dos_create_disklabel,
+	.list		= dos_list_disklabel,
+	.get_id		= dos_get_disklabel_id,
+	.set_id		= dos_set_disklabel_id,
+
+	.part_add	= dos_add_partition,
+	.part_delete	= dos_delete_partition,
+	.part_get_type	= dos_get_parttype,
+	.part_set_type	= dos_set_parttype,
+
+	.part_toggle_flag = dos_toggle_partition_flag,
+	.part_get_status = dos_get_partition_status,
+
+	.reset_alignment = dos_reset_alignment,
+
+	.deinit		= dos_deinit,
+};
+
+/*
+ * allocates DOS in-memory stuff
+ */
+struct fdisk_label *fdisk_new_dos_label(struct fdisk_context *cxt)
+{
+	struct fdisk_label *lb;
+	struct fdisk_dos_label *dos;
+
+	assert(cxt);
+
+	dos = calloc(1, sizeof(*dos));
+	if (!dos)
+		return NULL;
+
+	/* initialize generic part of the driver */
+	lb = (struct fdisk_label *) dos;
+	lb->name = "dos";
+	lb->id = FDISK_DISKLABEL_DOS;
+	lb->op = &dos_operations;
+	lb->parttypes = dos_parttypes;
+	lb->nparttypes = ARRAY_SIZE(dos_parttypes);
+
+	lb->flags |= FDISK_LABEL_FL_ADDPART_NOPARTNO;
+
+	return lb;
+}
+
+/*
+ * Public label specific functions
+ */
+
+int fdisk_dos_enable_compatible(struct fdisk_label *lb, int enable)
+{
+	struct fdisk_dos_label *dos = (struct fdisk_dos_label *) lb;
+
+	if (!lb)
+		return -EINVAL;
+
+	dos->compatible = enable;
+	if (enable)
+		lb->flags |= FDISK_LABEL_FL_REQUIRE_GEOMETRY;
+	return 0;
+}
+
+int fdisk_dos_is_compatible(struct fdisk_label *lb)
+{
+	return ((struct fdisk_dos_label *) lb)->compatible;
+}