[net-next-2.6.git] / fs / partitions / msdos.c

/*
 *  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"

/*
 * 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;
}

/*
 * 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)
{
	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);
			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 (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;

	data = read_part_sector(state, 0, &sect);
	if (!data)
		return -1;
	if (!msdos_magic_present(data + 510)) {
		put_dev_sector(sect);
		return 0;
	}

	if (aix_magic_present(state, data)) {
		put_dev_sector(sect);
		strlcat(state->pp_buf, " [AIX]", PAGE_SIZE);
		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);

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