[linux-block.git] / block / partitions / msdos.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  fs/partitions/msdos.c
 *
 *  Code extracted from drivers/block/genhd.c
 *  Copyright (C) 1991-1998  Linus Torvalds
 *
 *  Thanks to Branko Lankester, lankeste@fwi.uva.nl, who found a bug
 *  in the early extended-partition checks and added DM partitions
 *
 *  Support for DiskManager v6.0x added by Mark Lord,
 *  with information provided by OnTrack.  This now works for linux fdisk
 *  and LILO, as well as loadlin and bootln.  Note that disks other than
 *  /dev/hda *must* have a "DOS" type 0x51 partition in the first slot (hda1).
 *
 *  More flexible handling of extended partitions - aeb, 950831
 *
 *  Check partition table on IDE disks for common CHS translations
 *
 *  Re-organised Feb 1998 Russell King
 */
#include <linux/msdos_fs.h>

#include "check.h"
#include "msdos.h"
#include "efi.h"
#include "aix.h"

/*
 * Many architectures don't like unaligned accesses, while
 * the nr_sects and start_sect partition table entries are
 * at a 2 (mod 4) address.
 */
#include <asm/unaligned.h>

#define SYS_IND(p)	get_unaligned(&p->sys_ind)

static inline sector_t nr_sects(struct partition *p)
{
	return (sector_t)get_unaligned_le32(&p->nr_sects);
}

static inline sector_t start_sect(struct partition *p)
{
	return (sector_t)get_unaligned_le32(&p->start_sect);
}

static inline int is_extended_partition(struct partition *p)
{
	return (SYS_IND(p) == DOS_EXTENDED_PARTITION ||
		SYS_IND(p) == WIN98_EXTENDED_PARTITION ||
		SYS_IND(p) == LINUX_EXTENDED_PARTITION);
}

#define MSDOS_LABEL_MAGIC1	0x55
#define MSDOS_LABEL_MAGIC2	0xAA

static inline int
msdos_magic_present(unsigned char *p)
{
	return (p[0] == MSDOS_LABEL_MAGIC1 && p[1] == MSDOS_LABEL_MAGIC2);
}

/* Value is EBCDIC 'IBMA' */
#define AIX_LABEL_MAGIC1	0xC9
#define AIX_LABEL_MAGIC2	0xC2
#define AIX_LABEL_MAGIC3	0xD4
#define AIX_LABEL_MAGIC4	0xC1
static int aix_magic_present(struct parsed_partitions *state, unsigned char *p)
{
	struct partition *pt = (struct partition *) (p + 0x1be);
	Sector sect;
	unsigned char *d;
	int slot, ret = 0;

	if (!(p[0] == AIX_LABEL_MAGIC1 &&
		p[1] == AIX_LABEL_MAGIC2 &&
		p[2] == AIX_LABEL_MAGIC3 &&
		p[3] == AIX_LABEL_MAGIC4))
		return 0;
	/* Assume the partition table is valid if Linux partitions exists */
	for (slot = 1; slot <= 4; slot++, pt++) {
		if (pt->sys_ind == LINUX_SWAP_PARTITION ||
			pt->sys_ind == LINUX_RAID_PARTITION ||
			pt->sys_ind == LINUX_DATA_PARTITION ||
			pt->sys_ind == LINUX_LVM_PARTITION ||
			is_extended_partition(pt))
			return 0;
	}
	d = read_part_sector(state, 7, &sect);
	if (d) {
		if (d[0] == '_' && d[1] == 'L' && d[2] == 'V' && d[3] == 'M')
			ret = 1;
		put_dev_sector(sect);
	}
	return ret;
}

static void set_info(struct parsed_partitions *state, int slot,
		     u32 disksig)
{
	struct partition_meta_info *info = &state->parts[slot].info;

	snprintf(info->uuid, sizeof(info->uuid), "%08x-%02x", disksig,
		 slot);
	info->volname[0] = 0;
	state->parts[slot].has_info = true;
}

/*
 * Create devices for each logical partition in an extended partition.
 * The logical partitions form a linked list, with each entry being
 * a partition table with two entries.  The first entry
 * is the real data partition (with a start relative to the partition
 * table start).  The second is a pointer to the next logical partition
 * (with a start relative to the entire extended partition).
 * We do not create a Linux partition for the partition tables, but
 * only for the actual data partitions.
 */

static void parse_extended(struct parsed_partitions *state,
			   sector_t first_sector, sector_t first_size,
			   u32 disksig)
{
	struct partition *p;
	Sector sect;
	unsigned char *data;
	sector_t this_sector, this_size;
	sector_t sector_size = bdev_logical_block_size(state->bdev) / 512;
	int loopct = 0;		/* number of links followed
				   without finding a data partition */
	int i;

	this_sector = first_sector;
	this_size = first_size;

	while (1) {
		if (++loopct > 100)
			return;
		if (state->next == state->limit)
			return;
		data = read_part_sector(state, this_sector, &sect);
		if (!data)
			return;

		if (!msdos_magic_present(data + 510))
			goto done;

		p = (struct partition *) (data + 0x1be);

		/*
		 * Usually, the first entry is the real data partition,
		 * the 2nd entry is the next extended partition, or empty,
		 * and the 3rd and 4th entries are unused.
		 * However, DRDOS sometimes has the extended partition as
		 * the first entry (when the data partition is empty),
		 * and OS/2 seems to use all four entries.
		 */

		/*
		 * First process the data partition(s)
		 */
		for (i = 0; i < 4; i++, p++) {
			sector_t offs, size, next;

			if (!nr_sects(p) || is_extended_partition(p))
				continue;

			/* Check the 3rd and 4th entries -
			   these sometimes contain random garbage */
			offs = start_sect(p)*sector_size;
			size = nr_sects(p)*sector_size;
			next = this_sector + offs;
			if (i >= 2) {
				if (offs + size > this_size)
					continue;
				if (next < first_sector)
					continue;
				if (next + size > first_sector + first_size)
					continue;
			}

			put_partition(state, state->next, next, size);
			set_info(state, state->next, disksig);
			if (SYS_IND(p) == LINUX_RAID_PARTITION)
				state->parts[state->next].flags = ADDPART_FLAG_RAID;
			loopct = 0;
			if (++state->next == state->limit)
				goto done;
		}
		/*
		 * Next, process the (first) extended partition, if present.
		 * (So far, there seems to be no reason to make
		 *  parse_extended()  recursive and allow a tree
		 *  of extended partitions.)
		 * It should be a link to the next logical partition.
		 */
		p -= 4;
		for (i = 0; i < 4; i++, p++)
			if (nr_sects(p) && is_extended_partition(p))
				break;
		if (i == 4)
			goto done;	 /* nothing left to do */

		this_sector = first_sector + start_sect(p) * sector_size;
		this_size = nr_sects(p) * sector_size;
		put_dev_sector(sect);
	}
done:
	put_dev_sector(sect);
}

/* james@bpgc.com: Solaris has a nasty indicator: 0x82 which also
   indicates linux swap.  Be careful before believing this is Solaris. */

static void parse_solaris_x86(struct parsed_partitions *state,
			      sector_t offset, sector_t size, int origin)
{
#ifdef CONFIG_SOLARIS_X86_PARTITION
	Sector sect;
	struct solaris_x86_vtoc *v;
	int i;
	short max_nparts;

	v = read_part_sector(state, offset + 1, &sect);
	if (!v)
		return;
	if (le32_to_cpu(v->v_sanity) != SOLARIS_X86_VTOC_SANE) {
		put_dev_sector(sect);
		return;
	}
	{
		char tmp[1 + BDEVNAME_SIZE + 10 + 11 + 1];

		snprintf(tmp, sizeof(tmp), " %s%d: <solaris:", state->name, origin);
		strlcat(state->pp_buf, tmp, PAGE_SIZE);
	}
	if (le32_to_cpu(v->v_version) != 1) {
		char tmp[64];

		snprintf(tmp, sizeof(tmp), "  cannot handle version %d vtoc>\n",
			 le32_to_cpu(v->v_version));
		strlcat(state->pp_buf, tmp, PAGE_SIZE);
		put_dev_sector(sect);
		return;
	}
	/* Ensure we can handle previous case of VTOC with 8 entries gracefully */
	max_nparts = le16_to_cpu(v->v_nparts) > 8 ? SOLARIS_X86_NUMSLICE : 8;
	for (i = 0; i < max_nparts && state->next < state->limit; i++) {
		struct solaris_x86_slice *s = &v->v_slice[i];
		char tmp[3 + 10 + 1 + 1];

		if (s->s_size == 0)
			continue;
		snprintf(tmp, sizeof(tmp), " [s%d]", i);
		strlcat(state->pp_buf, tmp, PAGE_SIZE);
		/* solaris partitions are relative to current MS-DOS
		 * one; must add the offset of the current partition */
		put_partition(state, state->next++,
				 le32_to_cpu(s->s_start)+offset,
				 le32_to_cpu(s->s_size));
	}
	put_dev_sector(sect);
	strlcat(state->pp_buf, " >\n", PAGE_SIZE);
#endif
}

#if defined(CONFIG_BSD_DISKLABEL)
/*
 * Create devices for BSD partitions listed in a disklabel, under a
 * dos-like partition. See parse_extended() for more information.
 */
static void parse_bsd(struct parsed_partitions *state,
		      sector_t offset, sector_t size, int origin, char *flavour,
		      int max_partitions)
{
	Sector sect;
	struct bsd_disklabel *l;
	struct bsd_partition *p;
	char tmp[64];

	l = read_part_sector(state, offset + 1, &sect);
	if (!l)
		return;
	if (le32_to_cpu(l->d_magic) != BSD_DISKMAGIC) {
		put_dev_sector(sect);
		return;
	}

	snprintf(tmp, sizeof(tmp), " %s%d: <%s:", state->name, origin, flavour);
	strlcat(state->pp_buf, tmp, PAGE_SIZE);

	if (le16_to_cpu(l->d_npartitions) < max_partitions)
		max_partitions = le16_to_cpu(l->d_npartitions);
	for (p = l->d_partitions; p - l->d_partitions < max_partitions; p++) {
		sector_t bsd_start, bsd_size;

		if (state->next == state->limit)
			break;
		if (p->p_fstype == BSD_FS_UNUSED)
			continue;
		bsd_start = le32_to_cpu(p->p_offset);
		bsd_size = le32_to_cpu(p->p_size);
		if (memcmp(flavour, "bsd\0", 4) == 0)
			bsd_start += offset;
		if (offset == bsd_start && size == bsd_size)
			/* full parent partition, we have it already */
			continue;
		if (offset > bsd_start || offset+size < bsd_start+bsd_size) {
			strlcat(state->pp_buf, "bad subpartition - ignored\n", PAGE_SIZE);
			continue;
		}
		put_partition(state, state->next++, bsd_start, bsd_size);
	}
	put_dev_sector(sect);
	if (le16_to_cpu(l->d_npartitions) > max_partitions) {
		snprintf(tmp, sizeof(tmp), " (ignored %d more)",
			 le16_to_cpu(l->d_npartitions) - max_partitions);
		strlcat(state->pp_buf, tmp, PAGE_SIZE);
	}
	strlcat(state->pp_buf, " >\n", PAGE_SIZE);
}
#endif

static void parse_freebsd(struct parsed_partitions *state,
			  sector_t offset, sector_t size, int origin)
{
#ifdef CONFIG_BSD_DISKLABEL
	parse_bsd(state, offset, size, origin, "bsd", BSD_MAXPARTITIONS);
#endif
}

static void parse_netbsd(struct parsed_partitions *state,
			 sector_t offset, sector_t size, int origin)
{
#ifdef CONFIG_BSD_DISKLABEL
	parse_bsd(state, offset, size, origin, "netbsd", BSD_MAXPARTITIONS);
#endif
}

static void parse_openbsd(struct parsed_partitions *state,
			  sector_t offset, sector_t size, int origin)
{
#ifdef CONFIG_BSD_DISKLABEL
	parse_bsd(state, offset, size, origin, "openbsd",
		  OPENBSD_MAXPARTITIONS);
#endif
}

/*
 * Create devices for Unixware partitions listed in a disklabel, under a
 * dos-like partition. See parse_extended() for more information.
 */
static void parse_unixware(struct parsed_partitions *state,
			   sector_t offset, sector_t size, int origin)
{
#ifdef CONFIG_UNIXWARE_DISKLABEL
	Sector sect;
	struct unixware_disklabel *l;
	struct unixware_slice *p;

	l = read_part_sector(state, offset + 29, &sect);
	if (!l)
		return;
	if (le32_to_cpu(l->d_magic) != UNIXWARE_DISKMAGIC ||
	    le32_to_cpu(l->vtoc.v_magic) != UNIXWARE_DISKMAGIC2) {
		put_dev_sector(sect);
		return;
	}
	{
		char tmp[1 + BDEVNAME_SIZE + 10 + 12 + 1];

		snprintf(tmp, sizeof(tmp), " %s%d: <unixware:", state->name, origin);
		strlcat(state->pp_buf, tmp, PAGE_SIZE);
	}
	p = &l->vtoc.v_slice[1];
	/* I omit the 0th slice as it is the same as whole disk. */
	while (p - &l->vtoc.v_slice[0] < UNIXWARE_NUMSLICE) {
		if (state->next == state->limit)
			break;

		if (p->s_label != UNIXWARE_FS_UNUSED)
			put_partition(state, state->next++,
				      le32_to_cpu(p->start_sect),
				      le32_to_cpu(p->nr_sects));
		p++;
	}
	put_dev_sector(sect);
	strlcat(state->pp_buf, " >\n", PAGE_SIZE);
#endif
}

/*
 * Minix 2.0.0/2.0.2 subpartition support.
 * Anand Krishnamurthy <anandk@wiproge.med.ge.com>
 * Rajeev V. Pillai    <rajeevvp@yahoo.com>
 */
static void parse_minix(struct parsed_partitions *state,
			sector_t offset, sector_t size, int origin)
{
#ifdef CONFIG_MINIX_SUBPARTITION
	Sector sect;
	unsigned char *data;
	struct partition *p;
	int i;

	data = read_part_sector(state, offset, &sect);
	if (!data)
		return;

	p = (struct partition *)(data + 0x1be);

	/* The first sector of a Minix partition can have either
	 * a secondary MBR describing its subpartitions, or
	 * the normal boot sector. */
	if (msdos_magic_present(data + 510) &&
	    SYS_IND(p) == MINIX_PARTITION) { /* subpartition table present */
		char tmp[1 + BDEVNAME_SIZE + 10 + 9 + 1];

		snprintf(tmp, sizeof(tmp), " %s%d: <minix:", state->name, origin);
		strlcat(state->pp_buf, tmp, PAGE_SIZE);
		for (i = 0; i < MINIX_NR_SUBPARTITIONS; i++, p++) {
			if (state->next == state->limit)
				break;
			/* add each partition in use */
			if (SYS_IND(p) == MINIX_PARTITION)
				put_partition(state, state->next++,
					      start_sect(p), nr_sects(p));
		}
		strlcat(state->pp_buf, " >\n", PAGE_SIZE);
	}
	put_dev_sector(sect);
#endif /* CONFIG_MINIX_SUBPARTITION */
}

static struct {
	unsigned char id;
	void (*parse)(struct parsed_partitions *, sector_t, sector_t, int);
} subtypes[] = {
	{FREEBSD_PARTITION, parse_freebsd},
	{NETBSD_PARTITION, parse_netbsd},
	{OPENBSD_PARTITION, parse_openbsd},
	{MINIX_PARTITION, parse_minix},
	{UNIXWARE_PARTITION, parse_unixware},
	{SOLARIS_X86_PARTITION, parse_solaris_x86},
	{NEW_SOLARIS_X86_PARTITION, parse_solaris_x86},
	{0, NULL},
};

int msdos_partition(struct parsed_partitions *state)
{
	sector_t sector_size = bdev_logical_block_size(state->bdev) / 512;
	Sector sect;
	unsigned char *data;
	struct partition *p;
	struct fat_boot_sector *fb;
	int slot;
	u32 disksig;

	data = read_part_sector(state, 0, &sect);
	if (!data)
		return -1;

	/*
	 * Note order! (some AIX disks, e.g. unbootable kind,
	 * have no MSDOS 55aa)
	 */
	if (aix_magic_present(state, data)) {
		put_dev_sector(sect);
#ifdef CONFIG_AIX_PARTITION
		return aix_partition(state);
#else
		strlcat(state->pp_buf, " [AIX]", PAGE_SIZE);
		return 0;
#endif
	}

	if (!msdos_magic_present(data + 510)) {
		put_dev_sector(sect);
		return 0;
	}

	/*
	 * Now that the 55aa signature is present, this is probably
	 * either the boot sector of a FAT filesystem or a DOS-type
	 * partition table. Reject this in case the boot indicator
	 * is not 0 or 0x80.
	 */
	p = (struct partition *) (data + 0x1be);
	for (slot = 1; slot <= 4; slot++, p++) {
		if (p->boot_ind != 0 && p->boot_ind != 0x80) {
			/*
			 * Even without a valid boot inidicator value
			 * its still possible this is valid FAT filesystem
			 * without a partition table.
			 */
			fb = (struct fat_boot_sector *) data;
			if (slot == 1 && fb->reserved && fb->fats
				&& fat_valid_media(fb->media)) {
				strlcat(state->pp_buf, "\n", PAGE_SIZE);
				put_dev_sector(sect);
				return 1;
			} else {
				put_dev_sector(sect);
				return 0;
			}
		}
	}

#ifdef CONFIG_EFI_PARTITION
	p = (struct partition *) (data + 0x1be);
	for (slot = 1 ; slot <= 4 ; slot++, p++) {
		/* If this is an EFI GPT disk, msdos should ignore it. */
		if (SYS_IND(p) == EFI_PMBR_OSTYPE_EFI_GPT) {
			put_dev_sector(sect);
			return 0;
		}
	}
#endif
	p = (struct partition *) (data + 0x1be);

	disksig = le32_to_cpup((__le32 *)(data + 0x1b8));

	/*
	 * Look for partitions in two passes:
	 * First find the primary and DOS-type extended partitions.
	 * On the second pass look inside *BSD, Unixware and Solaris partitions.
	 */

	state->next = 5;
	for (slot = 1 ; slot <= 4 ; slot++, p++) {
		sector_t start = start_sect(p)*sector_size;
		sector_t size = nr_sects(p)*sector_size;

		if (!size)
			continue;
		if (is_extended_partition(p)) {
			/*
			 * prevent someone doing mkfs or mkswap on an
			 * extended partition, but leave room for LILO
			 * FIXME: this uses one logical sector for > 512b
			 * sector, although it may not be enough/proper.
			 */
			sector_t n = 2;

			n = min(size, max(sector_size, n));
			put_partition(state, slot, start, n);

			strlcat(state->pp_buf, " <", PAGE_SIZE);
			parse_extended(state, start, size, disksig);
			strlcat(state->pp_buf, " >", PAGE_SIZE);
			continue;
		}
		put_partition(state, slot, start, size);
		set_info(state, slot, disksig);
		if (SYS_IND(p) == LINUX_RAID_PARTITION)
			state->parts[slot].flags = ADDPART_FLAG_RAID;
		if (SYS_IND(p) == DM6_PARTITION)
			strlcat(state->pp_buf, "[DM]", PAGE_SIZE);
		if (SYS_IND(p) == EZD_PARTITION)
			strlcat(state->pp_buf, "[EZD]", PAGE_SIZE);
	}

	strlcat(state->pp_buf, "\n", PAGE_SIZE);

	/* second pass - output for each on a separate line */
	p = (struct partition *) (0x1be + data);
	for (slot = 1 ; slot <= 4 ; slot++, p++) {
		unsigned char id = SYS_IND(p);
		int n;

		if (!nr_sects(p))
			continue;

		for (n = 0; subtypes[n].parse && id != subtypes[n].id; n++)
			;

		if (!subtypes[n].parse)
			continue;
		subtypes[n].parse(state, start_sect(p) * sector_size,
				  nr_sects(p) * sector_size, slot);
	}
	put_dev_sector(sect);
	return 1;
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2	/*
	3	* fs/partitions/msdos.c
	4	*
	5	* Code extracted from drivers/block/genhd.c
	6	* Copyright (C) 1991-1998 Linus Torvalds
	7	*
	8	* Thanks to Branko Lankester, lankeste@fwi.uva.nl, who found a bug
	9	* in the early extended-partition checks and added DM partitions
	10	*
	11	* Support for DiskManager v6.0x added by Mark Lord,
	12	* with information provided by OnTrack. This now works for linux fdisk
	13	* and LILO, as well as loadlin and bootln. Note that disks other than
	14	* /dev/hda must have a "DOS" type 0x51 partition in the first slot (hda1).
	15	*
	16	* More flexible handling of extended partitions - aeb, 950831
	17	*
	18	* Check partition table on IDE disks for common CHS translations
	19	*
	20	* Re-organised Feb 1998 Russell King
	21	*/
0607fd02	22	#include <linux/msdos_fs.h>
1da177e4 LT	23
	24	#include "check.h"
	25	#include "msdos.h"
	26	#include "efi.h"
f8f06603	27	#include "aix.h"
1da177e4 LT	28
	29	/*
	30	* Many architectures don't like unaligned accesses, while
	31	* the nr_sects and start_sect partition table entries are
	32	* at a 2 (mod 4) address.
	33	*/
	34	#include <asm/unaligned.h>
	35
3fbf586c	36	#define SYS_IND(p) get_unaligned(&p->sys_ind)
1da177e4	37
3fbf586c DT	38	static inline sector_t nr_sects(struct partition *p)
	39	{
	40	return (sector_t)get_unaligned_le32(&p->nr_sects);
	41	}
	42
	43	static inline sector_t start_sect(struct partition *p)
	44	{
	45	return (sector_t)get_unaligned_le32(&p->start_sect);
	46	}
1da177e4 LT	47
	48	static inline int is_extended_partition(struct partition *p)
	49	{
	50	return (SYS_IND(p) == DOS_EXTENDED_PARTITION \|\|
	51	SYS_IND(p) == WIN98_EXTENDED_PARTITION \|\|
	52	SYS_IND(p) == LINUX_EXTENDED_PARTITION);
	53	}
	54
	55	#define MSDOS_LABEL_MAGIC1 0x55
	56	#define MSDOS_LABEL_MAGIC2 0xAA
	57
	58	static inline int
	59	msdos_magic_present(unsigned char *p)
	60	{
	61	return (p[0] == MSDOS_LABEL_MAGIC1 && p[1] == MSDOS_LABEL_MAGIC2);
	62	}
	63
e1dfa92d OH	64	/* Value is EBCDIC 'IBMA' */
	65	#define AIX_LABEL_MAGIC1 0xC9
	66	#define AIX_LABEL_MAGIC2 0xC2
	67	#define AIX_LABEL_MAGIC3 0xD4
	68	#define AIX_LABEL_MAGIC4 0xC1
1493bf21	69	static int aix_magic_present(struct parsed_partitions state, unsigned char p)
e1dfa92d	70	{
4419d1ac	71	struct partition pt = (struct partition ) (p + 0x1be);
e1dfa92d OH	72	Sector sect;
e1dfa92d OH	73	unsigned char *d;
4419d1ac	74	int slot, ret = 0;
e1dfa92d	75
a470e18f OH	76	if (!(p[0] == AIX_LABEL_MAGIC1 &&
	77	p[1] == AIX_LABEL_MAGIC2 &&
	78	p[2] == AIX_LABEL_MAGIC3 &&
	79	p[3] == AIX_LABEL_MAGIC4))
e1dfa92d	80	return 0;
4419d1ac OH	81	/* Assume the partition table is valid if Linux partitions exists */
	82	for (slot = 1; slot <= 4; slot++, pt++) {
	83	if (pt->sys_ind == LINUX_SWAP_PARTITION \|\|
	84	pt->sys_ind == LINUX_RAID_PARTITION \|\|
	85	pt->sys_ind == LINUX_DATA_PARTITION \|\|
	86	pt->sys_ind == LINUX_LVM_PARTITION \|\|
	87	is_extended_partition(pt))
	88	return 0;
	89	}
1493bf21	90	d = read_part_sector(state, 7, &sect);
e1dfa92d OH	91	if (d) {
	92	if (d[0] == '_' && d[1] == 'L' && d[2] == 'V' && d[3] == 'M')
	93	ret = 1;
	94	put_dev_sector(sect);
1d04f3c6	95	}
e1dfa92d OH	96	return ret;
	97	}
	98
d33b98fc SW	99	static void set_info(struct parsed_partitions *state, int slot,
	100	u32 disksig)
	101	{
	102	struct partition_meta_info *info = &state->parts[slot].info;
	103
	104	snprintf(info->uuid, sizeof(info->uuid), "%08x-%02x", disksig,
	105	slot);
	106	info->volname[0] = 0;
	107	state->parts[slot].has_info = true;
	108	}
	109
1da177e4 LT	110	/*
	111	* Create devices for each logical partition in an extended partition.
	112	* The logical partitions form a linked list, with each entry being
	113	* a partition table with two entries. The first entry
	114	* is the real data partition (with a start relative to the partition
	115	* table start). The second is a pointer to the next logical partition
	116	* (with a start relative to the entire extended partition).
	117	* We do not create a Linux partition for the partition tables, but
	118	* only for the actual data partitions.
	119	*/
	120
1493bf21	121	static void parse_extended(struct parsed_partitions *state,
d33b98fc SW	122	sector_t first_sector, sector_t first_size,
d33b98fc SW	123	u32 disksig)
1da177e4 LT	124	{
	125	struct partition *p;
	126	Sector sect;
	127	unsigned char *data;
3fbf586c	128	sector_t this_sector, this_size;
1493bf21	129	sector_t sector_size = bdev_logical_block_size(state->bdev) / 512;
1da177e4 LT	130	int loopct = 0; /* number of links followed
	131	without finding a data partition */
	132	int i;
	133
	134	this_sector = first_sector;
	135	this_size = first_size;
	136
	137	while (1) {
	138	if (++loopct > 100)
	139	return;
	140	if (state->next == state->limit)
	141	return;
1493bf21	142	data = read_part_sector(state, this_sector, &sect);
1da177e4 LT	143	if (!data)
	144	return;
	145
	146	if (!msdos_magic_present(data + 510))
1d04f3c6	147	goto done;
1da177e4 LT	148
	149	p = (struct partition *) (data + 0x1be);
	150
	151	/*
	152	* Usually, the first entry is the real data partition,
	153	* the 2nd entry is the next extended partition, or empty,
	154	* and the 3rd and 4th entries are unused.
	155	* However, DRDOS sometimes has the extended partition as
	156	* the first entry (when the data partition is empty),
	157	* and OS/2 seems to use all four entries.
	158	*/
	159
1d04f3c6	160	/*
1da177e4 LT	161	* First process the data partition(s)
1da177e4 LT	162	*/
dce14c23	163	for (i = 0; i < 4; i++, p++) {
3fbf586c	164	sector_t offs, size, next;
dce14c23	165
3fbf586c	166	if (!nr_sects(p) \|\| is_extended_partition(p))
1da177e4 LT	167	continue;
	168
	169	/* Check the 3rd and 4th entries -
	170	these sometimes contain random garbage */
3fbf586c DT	171	offs = start_sect(p)*sector_size;
3fbf586c DT	172	size = nr_sects(p)*sector_size;
1da177e4 LT	173	next = this_sector + offs;
	174	if (i >= 2) {
	175	if (offs + size > this_size)
	176	continue;
	177	if (next < first_sector)
	178	continue;
	179	if (next + size > first_sector + first_size)
	180	continue;
	181	}
	182
	183	put_partition(state, state->next, next, size);
d33b98fc	184	set_info(state, state->next, disksig);
1da177e4	185	if (SYS_IND(p) == LINUX_RAID_PARTITION)
d18d7682	186	state->parts[state->next].flags = ADDPART_FLAG_RAID;
1da177e4 LT	187	loopct = 0;
	188	if (++state->next == state->limit)
	189	goto done;
	190	}
	191	/*
	192	* Next, process the (first) extended partition, if present.
	193	* (So far, there seems to be no reason to make
	194	* parse_extended() recursive and allow a tree
	195	* of extended partitions.)
	196	* It should be a link to the next logical partition.
	197	*/
	198	p -= 4;
dce14c23	199	for (i = 0; i < 4; i++, p++)
3fbf586c	200	if (nr_sects(p) && is_extended_partition(p))
1da177e4 LT	201	break;
	202	if (i == 4)
	203	goto done; /* nothing left to do */
	204
3fbf586c DT	205	this_sector = first_sector + start_sect(p) * sector_size;
3fbf586c DT	206	this_size = nr_sects(p) * sector_size;
1da177e4 LT	207	put_dev_sector(sect);
	208	}
	209	done:
	210	put_dev_sector(sect);
	211	}
	212
	213	/* james@bpgc.com: Solaris has a nasty indicator: 0x82 which also
	214	indicates linux swap. Be careful before believing this is Solaris. */
	215
1493bf21 TH	216	static void parse_solaris_x86(struct parsed_partitions *state,
1493bf21 TH	217	sector_t offset, sector_t size, int origin)
1da177e4 LT	218	{
	219	#ifdef CONFIG_SOLARIS_X86_PARTITION
	220	Sector sect;
	221	struct solaris_x86_vtoc *v;
	222	int i;
b84d8796	223	short max_nparts;
1da177e4	224
1493bf21	225	v = read_part_sector(state, offset + 1, &sect);
1da177e4 LT	226	if (!v)
	227	return;
	228	if (le32_to_cpu(v->v_sanity) != SOLARIS_X86_VTOC_SANE) {
	229	put_dev_sector(sect);
	230	return;
	231	}
9c867fbe AD	232	{
	233	char tmp[1 + BDEVNAME_SIZE + 10 + 11 + 1];
	234
	235	snprintf(tmp, sizeof(tmp), " %s%d: <solaris:", state->name, origin);
	236	strlcat(state->pp_buf, tmp, PAGE_SIZE);
	237	}
1da177e4	238	if (le32_to_cpu(v->v_version) != 1) {
9c867fbe AD	239	char tmp[64];
	240
	241	snprintf(tmp, sizeof(tmp), " cannot handle version %d vtoc>\n",
	242	le32_to_cpu(v->v_version));
	243	strlcat(state->pp_buf, tmp, PAGE_SIZE);
1da177e4 LT	244	put_dev_sector(sect);
	245	return;
	246	}
b84d8796	247	/* Ensure we can handle previous case of VTOC with 8 entries gracefully */
dce14c23 FF	248	max_nparts = le16_to_cpu(v->v_nparts) > 8 ? SOLARIS_X86_NUMSLICE : 8;
dce14c23 FF	249	for (i = 0; i < max_nparts && state->next < state->limit; i++) {
1da177e4	250	struct solaris_x86_slice *s = &v->v_slice[i];
9c867fbe AD	251	char tmp[3 + 10 + 1 + 1];
9c867fbe AD	252
1da177e4 LT	253	if (s->s_size == 0)
1da177e4 LT	254	continue;
9c867fbe AD	255	snprintf(tmp, sizeof(tmp), " [s%d]", i);
9c867fbe AD	256	strlcat(state->pp_buf, tmp, PAGE_SIZE);
1da177e4 LT	257	/* solaris partitions are relative to current MS-DOS
	258	* one; must add the offset of the current partition */
	259	put_partition(state, state->next++,
	260	le32_to_cpu(s->s_start)+offset,
	261	le32_to_cpu(s->s_size));
	262	}
	263	put_dev_sector(sect);
9c867fbe	264	strlcat(state->pp_buf, " >\n", PAGE_SIZE);
1da177e4 LT	265	#endif
	266	}
	267
486fd404	268	#if defined(CONFIG_BSD_DISKLABEL)
1d04f3c6	269	/*
1da177e4 LT	270	* Create devices for BSD partitions listed in a disklabel, under a
	271	* dos-like partition. See parse_extended() for more information.
	272	*/
1493bf21 TH	273	static void parse_bsd(struct parsed_partitions *state,
	274	sector_t offset, sector_t size, int origin, char *flavour,
	275	int max_partitions)
1da177e4 LT	276	{
	277	Sector sect;
	278	struct bsd_disklabel *l;
	279	struct bsd_partition *p;
9c867fbe	280	char tmp[64];
1da177e4	281
1493bf21	282	l = read_part_sector(state, offset + 1, &sect);
1da177e4 LT	283	if (!l)
	284	return;
	285	if (le32_to_cpu(l->d_magic) != BSD_DISKMAGIC) {
	286	put_dev_sector(sect);
	287	return;
	288	}
9c867fbe AD	289
	290	snprintf(tmp, sizeof(tmp), " %s%d: <%s:", state->name, origin, flavour);
	291	strlcat(state->pp_buf, tmp, PAGE_SIZE);
1da177e4 LT	292
	293	if (le16_to_cpu(l->d_npartitions) < max_partitions)
	294	max_partitions = le16_to_cpu(l->d_npartitions);
	295	for (p = l->d_partitions; p - l->d_partitions < max_partitions; p++) {
3fbf586c	296	sector_t bsd_start, bsd_size;
1da177e4 LT	297
	298	if (state->next == state->limit)
	299	break;
1d04f3c6	300	if (p->p_fstype == BSD_FS_UNUSED)
1da177e4 LT	301	continue;
	302	bsd_start = le32_to_cpu(p->p_offset);
	303	bsd_size = le32_to_cpu(p->p_size);
22322035 R	304	if (memcmp(flavour, "bsd\0", 4) == 0)
22322035 R	305	bsd_start += offset;
1da177e4 LT	306	if (offset == bsd_start && size == bsd_size)
	307	/* full parent partition, we have it already */
	308	continue;
	309	if (offset > bsd_start \|\| offset+size < bsd_start+bsd_size) {
9c867fbe	310	strlcat(state->pp_buf, "bad subpartition - ignored\n", PAGE_SIZE);
1da177e4 LT	311	continue;
	312	}
	313	put_partition(state, state->next++, bsd_start, bsd_size);
	314	}
	315	put_dev_sector(sect);
9c867fbe AD	316	if (le16_to_cpu(l->d_npartitions) > max_partitions) {
	317	snprintf(tmp, sizeof(tmp), " (ignored %d more)",
	318	le16_to_cpu(l->d_npartitions) - max_partitions);
	319	strlcat(state->pp_buf, tmp, PAGE_SIZE);
	320	}
	321	strlcat(state->pp_buf, " >\n", PAGE_SIZE);
1da177e4 LT	322	}
	323	#endif
	324
1493bf21 TH	325	static void parse_freebsd(struct parsed_partitions *state,
1493bf21 TH	326	sector_t offset, sector_t size, int origin)
1da177e4 LT	327	{
1da177e4 LT	328	#ifdef CONFIG_BSD_DISKLABEL
1493bf21	329	parse_bsd(state, offset, size, origin, "bsd", BSD_MAXPARTITIONS);
1da177e4 LT	330	#endif
	331	}
	332
1493bf21 TH	333	static void parse_netbsd(struct parsed_partitions *state,
1493bf21 TH	334	sector_t offset, sector_t size, int origin)
1da177e4 LT	335	{
1da177e4 LT	336	#ifdef CONFIG_BSD_DISKLABEL
1493bf21	337	parse_bsd(state, offset, size, origin, "netbsd", BSD_MAXPARTITIONS);
1da177e4 LT	338	#endif
	339	}
	340
1493bf21 TH	341	static void parse_openbsd(struct parsed_partitions *state,
1493bf21 TH	342	sector_t offset, sector_t size, int origin)
1da177e4 LT	343	{
1da177e4 LT	344	#ifdef CONFIG_BSD_DISKLABEL
1493bf21 TH	345	parse_bsd(state, offset, size, origin, "openbsd",
1493bf21 TH	346	OPENBSD_MAXPARTITIONS);
1da177e4 LT	347	#endif
	348	}
	349
	350	/*
	351	* Create devices for Unixware partitions listed in a disklabel, under a
	352	* dos-like partition. See parse_extended() for more information.
	353	*/
1493bf21 TH	354	static void parse_unixware(struct parsed_partitions *state,
1493bf21 TH	355	sector_t offset, sector_t size, int origin)
1da177e4 LT	356	{
	357	#ifdef CONFIG_UNIXWARE_DISKLABEL
	358	Sector sect;
	359	struct unixware_disklabel *l;
	360	struct unixware_slice *p;
	361
1493bf21	362	l = read_part_sector(state, offset + 29, &sect);
1da177e4 LT	363	if (!l)
	364	return;
	365	if (le32_to_cpu(l->d_magic) != UNIXWARE_DISKMAGIC \|\|
	366	le32_to_cpu(l->vtoc.v_magic) != UNIXWARE_DISKMAGIC2) {
	367	put_dev_sector(sect);
	368	return;
	369	}
9c867fbe AD	370	{
	371	char tmp[1 + BDEVNAME_SIZE + 10 + 12 + 1];
	372
	373	snprintf(tmp, sizeof(tmp), " %s%d: <unixware:", state->name, origin);
	374	strlcat(state->pp_buf, tmp, PAGE_SIZE);
	375	}
1da177e4 LT	376	p = &l->vtoc.v_slice[1];
	377	/* I omit the 0th slice as it is the same as whole disk. */
	378	while (p - &l->vtoc.v_slice[0] < UNIXWARE_NUMSLICE) {
	379	if (state->next == state->limit)
	380	break;
	381
	382	if (p->s_label != UNIXWARE_FS_UNUSED)
	383	put_partition(state, state->next++,
3fbf586c DT	384	le32_to_cpu(p->start_sect),
3fbf586c DT	385	le32_to_cpu(p->nr_sects));
1da177e4 LT	386	p++;
	387	}
	388	put_dev_sector(sect);
9c867fbe	389	strlcat(state->pp_buf, " >\n", PAGE_SIZE);
1da177e4 LT	390	#endif
	391	}
	392
	393	/*
	394	* Minix 2.0.0/2.0.2 subpartition support.
	395	* Anand Krishnamurthy <anandk@wiproge.med.ge.com>
	396	* Rajeev V. Pillai <rajeevvp@yahoo.com>
	397	*/
1493bf21 TH	398	static void parse_minix(struct parsed_partitions *state,
1493bf21 TH	399	sector_t offset, sector_t size, int origin)
1da177e4 LT	400	{
	401	#ifdef CONFIG_MINIX_SUBPARTITION
	402	Sector sect;
	403	unsigned char *data;
	404	struct partition *p;
	405	int i;
	406
1493bf21	407	data = read_part_sector(state, offset, &sect);
1da177e4 LT	408	if (!data)
	409	return;
	410
	411	p = (struct partition *)(data + 0x1be);
	412
	413	/* The first sector of a Minix partition can have either
	414	* a secondary MBR describing its subpartitions, or
	415	* the normal boot sector. */
dce14c23	416	if (msdos_magic_present(data + 510) &&
1da177e4	417	SYS_IND(p) == MINIX_PARTITION) { /* subpartition table present */
9c867fbe	418	char tmp[1 + BDEVNAME_SIZE + 10 + 9 + 1];
1da177e4	419
9c867fbe AD	420	snprintf(tmp, sizeof(tmp), " %s%d: <minix:", state->name, origin);
9c867fbe AD	421	strlcat(state->pp_buf, tmp, PAGE_SIZE);
1da177e4 LT	422	for (i = 0; i < MINIX_NR_SUBPARTITIONS; i++, p++) {
	423	if (state->next == state->limit)
	424	break;
	425	/* add each partition in use */
	426	if (SYS_IND(p) == MINIX_PARTITION)
	427	put_partition(state, state->next++,
3fbf586c	428	start_sect(p), nr_sects(p));
1da177e4	429	}
9c867fbe	430	strlcat(state->pp_buf, " >\n", PAGE_SIZE);
1da177e4 LT	431	}
	432	put_dev_sector(sect);
	433	#endif /* CONFIG_MINIX_SUBPARTITION */
	434	}
	435
	436	static struct {
	437	unsigned char id;
1493bf21	438	void (parse)(struct parsed_partitions , sector_t, sector_t, int);
1da177e4 LT	439	} subtypes[] = {
	440	{FREEBSD_PARTITION, parse_freebsd},
	441	{NETBSD_PARTITION, parse_netbsd},
	442	{OPENBSD_PARTITION, parse_openbsd},
	443	{MINIX_PARTITION, parse_minix},
	444	{UNIXWARE_PARTITION, parse_unixware},
	445	{SOLARIS_X86_PARTITION, parse_solaris_x86},
	446	{NEW_SOLARIS_X86_PARTITION, parse_solaris_x86},
	447	{0, NULL},
	448	};
1d04f3c6	449
1493bf21	450	int msdos_partition(struct parsed_partitions *state)
1da177e4	451	{
1493bf21	452	sector_t sector_size = bdev_logical_block_size(state->bdev) / 512;
1da177e4 LT	453	Sector sect;
	454	unsigned char *data;
	455	struct partition *p;
0607fd02	456	struct fat_boot_sector *fb;
1da177e4	457	int slot;
d33b98fc	458	u32 disksig;
1da177e4	459
1493bf21	460	data = read_part_sector(state, 0, &sect);
1da177e4 LT	461	if (!data)
1da177e4 LT	462	return -1;
86ee8ba6 PDM	463
	464	/*
	465	* Note order! (some AIX disks, e.g. unbootable kind,
	466	* have no MSDOS 55aa)
	467	*/
	468	if (aix_magic_present(state, data)) {
1da177e4	469	put_dev_sector(sect);
f8f06603 PDM	470	#ifdef CONFIG_AIX_PARTITION
	471	return aix_partition(state);
	472	#else
86ee8ba6	473	strlcat(state->pp_buf, " [AIX]", PAGE_SIZE);
1da177e4	474	return 0;
f8f06603	475	#endif
1da177e4 LT	476	}
1da177e4 LT	477
86ee8ba6	478	if (!msdos_magic_present(data + 510)) {
e1dfa92d	479	put_dev_sector(sect);
e1dfa92d OH	480	return 0;
	481	}
	482
1da177e4 LT	483	/*
	484	* Now that the 55aa signature is present, this is probably
	485	* either the boot sector of a FAT filesystem or a DOS-type
	486	* partition table. Reject this in case the boot indicator
	487	* is not 0 or 0x80.
	488	*/
	489	p = (struct partition *) (data + 0x1be);
	490	for (slot = 1; slot <= 4; slot++, p++) {
	491	if (p->boot_ind != 0 && p->boot_ind != 0x80) {
0607fd02 FS	492	/*
	493	* Even without a valid boot inidicator value
	494	* its still possible this is valid FAT filesystem
	495	* without a partition table.
	496	*/
	497	fb = (struct fat_boot_sector *) data;
	498	if (slot == 1 && fb->reserved && fb->fats
	499	&& fat_valid_media(fb->media)) {
9c867fbe	500	strlcat(state->pp_buf, "\n", PAGE_SIZE);
0607fd02 FS	501	put_dev_sector(sect);
	502	return 1;
	503	} else {
	504	put_dev_sector(sect);
	505	return 0;
	506	}
1da177e4 LT	507	}
	508	}
	509
	510	#ifdef CONFIG_EFI_PARTITION
	511	p = (struct partition *) (data + 0x1be);
	512	for (slot = 1 ; slot <= 4 ; slot++, p++) {
	513	/* If this is an EFI GPT disk, msdos should ignore it. */
	514	if (SYS_IND(p) == EFI_PMBR_OSTYPE_EFI_GPT) {
	515	put_dev_sector(sect);
	516	return 0;
	517	}
	518	}
	519	#endif
	520	p = (struct partition *) (data + 0x1be);
	521
d33b98fc SW	522	disksig = le32_to_cpup((__le32 *)(data + 0x1b8));
d33b98fc SW	523
1da177e4 LT	524	/*
	525	* Look for partitions in two passes:
	526	* First find the primary and DOS-type extended partitions.
	527	* On the second pass look inside *BSD, Unixware and Solaris partitions.
	528	*/
	529
	530	state->next = 5;
	531	for (slot = 1 ; slot <= 4 ; slot++, p++) {
3fbf586c DT	532	sector_t start = start_sect(p)*sector_size;
3fbf586c DT	533	sector_t size = nr_sects(p)*sector_size;
dce14c23	534
1da177e4 LT	535	if (!size)
	536	continue;
	537	if (is_extended_partition(p)) {
8e0cc811 OH	538	/*
	539	* prevent someone doing mkfs or mkswap on an
	540	* extended partition, but leave room for LILO
	541	* FIXME: this uses one logical sector for > 512b
	542	* sector, although it may not be enough/proper.
	543	*/
	544	sector_t n = 2;
dce14c23	545
8e0cc811 OH	546	n = min(size, max(sector_size, n));
	547	put_partition(state, slot, start, n);
	548
9c867fbe	549	strlcat(state->pp_buf, " <", PAGE_SIZE);
d33b98fc	550	parse_extended(state, start, size, disksig);
9c867fbe	551	strlcat(state->pp_buf, " >", PAGE_SIZE);
1da177e4 LT	552	continue;
	553	}
	554	put_partition(state, slot, start, size);
d33b98fc	555	set_info(state, slot, disksig);
1da177e4	556	if (SYS_IND(p) == LINUX_RAID_PARTITION)
cc910624	557	state->parts[slot].flags = ADDPART_FLAG_RAID;
1da177e4	558	if (SYS_IND(p) == DM6_PARTITION)
9c867fbe	559	strlcat(state->pp_buf, "[DM]", PAGE_SIZE);
1da177e4	560	if (SYS_IND(p) == EZD_PARTITION)
9c867fbe	561	strlcat(state->pp_buf, "[EZD]", PAGE_SIZE);
1da177e4 LT	562	}
1da177e4 LT	563
9c867fbe	564	strlcat(state->pp_buf, "\n", PAGE_SIZE);
1da177e4 LT	565
	566	/* second pass - output for each on a separate line */
	567	p = (struct partition *) (0x1be + data);
	568	for (slot = 1 ; slot <= 4 ; slot++, p++) {
	569	unsigned char id = SYS_IND(p);
	570	int n;
	571
3fbf586c	572	if (!nr_sects(p))
1da177e4 LT	573	continue;
	574
	575	for (n = 0; subtypes[n].parse && id != subtypes[n].id; n++)
	576	;
	577
	578	if (!subtypes[n].parse)
	579	continue;
1493bf21 TH	580	subtypes[n].parse(state, start_sect(p) * sector_size,
1493bf21 TH	581	nr_sects(p) * sector_size, slot);
1da177e4 LT	582	}
	583	put_dev_sector(sect);
	584	return 1;
	585	}