[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;
	}
	printk(" %s%d: <solaris:", state->name, origin);
	if (le32_to_cpu(v->v_version) != 1) {
		printk("  cannot handle version %d vtoc>\n",
			le32_to_cpu(v->v_version));
		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];
		if (s->s_size == 0)
			continue;
		printk(" [s%d]", i);
		/* 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);
	printk(" >\n");
#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;

	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;
	}
	printk(" %s%d: <%s:", state->name, origin, flavour);

	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) {
			printk("bad subpartition - ignored\n");
			continue;
		}
		put_partition(state, state->next++, bsd_start, bsd_size);
	}
	put_dev_sector(sect);
	if (le16_to_cpu(l->d_npartitions) > max_partitions)
		printk(" (ignored %d more)",
		       le16_to_cpu(l->d_npartitions) - max_partitions);
	printk(" >\n");
}
#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;
	}
	printk(" %s%d: <unixware:", state->name, origin);
	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);
	printk(" >\n");
#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 */

		printk(" %s%d: <minix:", state->name, origin);
		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));
		}
		printk(" >\n");
	}
	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);
		printk( " [AIX]");
		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)) {
				printk("\n");
				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);

			printk(" <");
			parse_extended(state, start, size);
			printk(" >");
			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)
			printk("[DM]");
		if (SYS_IND(p) == EZD_PARTITION)
			printk("[EZD]");
	}

	printk("\n");

	/* 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	}
	216	printk(" %s%d: <solaris:", state->name, origin);
	217	if (le32_to_cpu(v->v_version) != 1) {
	218	printk(" cannot handle version %d vtoc>\n",
	219	le32_to_cpu(v->v_version));
	220	put_dev_sector(sect);
	221	return;
	222	}
b84d8796 MF	223	/* Ensure we can handle previous case of VTOC with 8 entries gracefully */
	224	max_nparts = le16_to_cpu (v->v_nparts) > 8 ? SOLARIS_X86_NUMSLICE : 8;
	225	for (i=0; i<max_nparts && state->next<state->limit; i++) {
1da177e4 LT	226	struct solaris_x86_slice *s = &v->v_slice[i];
	227	if (s->s_size == 0)
	228	continue;
	229	printk(" [s%d]", i);
	230	/* solaris partitions are relative to current MS-DOS
	231	* one; must add the offset of the current partition */
	232	put_partition(state, state->next++,
	233	le32_to_cpu(s->s_start)+offset,
	234	le32_to_cpu(s->s_size));
	235	}
	236	put_dev_sector(sect);
	237	printk(" >\n");
	238	#endif
	239	}
	240
486fd404	241	#if defined(CONFIG_BSD_DISKLABEL)
1da177e4 LT	242	/*
	243	* Create devices for BSD partitions listed in a disklabel, under a
	244	* dos-like partition. See parse_extended() for more information.
	245	*/
1493bf21 TH	246	static void parse_bsd(struct parsed_partitions *state,
	247	sector_t offset, sector_t size, int origin, char *flavour,
	248	int max_partitions)
1da177e4 LT	249	{
	250	Sector sect;
	251	struct bsd_disklabel *l;
	252	struct bsd_partition *p;
	253
1493bf21	254	l = read_part_sector(state, offset + 1, &sect);
1da177e4 LT	255	if (!l)
	256	return;
	257	if (le32_to_cpu(l->d_magic) != BSD_DISKMAGIC) {
	258	put_dev_sector(sect);
	259	return;
	260	}
	261	printk(" %s%d: <%s:", state->name, origin, flavour);
	262
	263	if (le16_to_cpu(l->d_npartitions) < max_partitions)
	264	max_partitions = le16_to_cpu(l->d_npartitions);
	265	for (p = l->d_partitions; p - l->d_partitions < max_partitions; p++) {
3fbf586c	266	sector_t bsd_start, bsd_size;
1da177e4 LT	267
	268	if (state->next == state->limit)
	269	break;
	270	if (p->p_fstype == BSD_FS_UNUSED)
	271	continue;
	272	bsd_start = le32_to_cpu(p->p_offset);
	273	bsd_size = le32_to_cpu(p->p_size);
	274	if (offset == bsd_start && size == bsd_size)
	275	/* full parent partition, we have it already */
	276	continue;
	277	if (offset > bsd_start \|\| offset+size < bsd_start+bsd_size) {
	278	printk("bad subpartition - ignored\n");
	279	continue;
	280	}
	281	put_partition(state, state->next++, bsd_start, bsd_size);
	282	}
	283	put_dev_sector(sect);
	284	if (le16_to_cpu(l->d_npartitions) > max_partitions)
	285	printk(" (ignored %d more)",
	286	le16_to_cpu(l->d_npartitions) - max_partitions);
	287	printk(" >\n");
	288	}
	289	#endif
	290
1493bf21 TH	291	static void parse_freebsd(struct parsed_partitions *state,
1493bf21 TH	292	sector_t offset, sector_t size, int origin)
1da177e4 LT	293	{
1da177e4 LT	294	#ifdef CONFIG_BSD_DISKLABEL
1493bf21	295	parse_bsd(state, offset, size, origin, "bsd", BSD_MAXPARTITIONS);
1da177e4 LT	296	#endif
	297	}
	298
1493bf21 TH	299	static void parse_netbsd(struct parsed_partitions *state,
1493bf21 TH	300	sector_t offset, sector_t size, int origin)
1da177e4 LT	301	{
1da177e4 LT	302	#ifdef CONFIG_BSD_DISKLABEL
1493bf21	303	parse_bsd(state, offset, size, origin, "netbsd", BSD_MAXPARTITIONS);
1da177e4 LT	304	#endif
	305	}
	306
1493bf21 TH	307	static void parse_openbsd(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 TH	311	parse_bsd(state, offset, size, origin, "openbsd",
1493bf21 TH	312	OPENBSD_MAXPARTITIONS);
1da177e4 LT	313	#endif
	314	}
	315
	316	/*
	317	* Create devices for Unixware partitions listed in a disklabel, under a
	318	* dos-like partition. See parse_extended() for more information.
	319	*/
1493bf21 TH	320	static void parse_unixware(struct parsed_partitions *state,
1493bf21 TH	321	sector_t offset, sector_t size, int origin)
1da177e4 LT	322	{
	323	#ifdef CONFIG_UNIXWARE_DISKLABEL
	324	Sector sect;
	325	struct unixware_disklabel *l;
	326	struct unixware_slice *p;
	327
1493bf21	328	l = read_part_sector(state, offset + 29, &sect);
1da177e4 LT	329	if (!l)
	330	return;
	331	if (le32_to_cpu(l->d_magic) != UNIXWARE_DISKMAGIC \|\|
	332	le32_to_cpu(l->vtoc.v_magic) != UNIXWARE_DISKMAGIC2) {
	333	put_dev_sector(sect);
	334	return;
	335	}
	336	printk(" %s%d: <unixware:", state->name, origin);
	337	p = &l->vtoc.v_slice[1];
	338	/* I omit the 0th slice as it is the same as whole disk. */
	339	while (p - &l->vtoc.v_slice[0] < UNIXWARE_NUMSLICE) {
	340	if (state->next == state->limit)
	341	break;
	342
	343	if (p->s_label != UNIXWARE_FS_UNUSED)
	344	put_partition(state, state->next++,
3fbf586c DT	345	le32_to_cpu(p->start_sect),
3fbf586c DT	346	le32_to_cpu(p->nr_sects));
1da177e4 LT	347	p++;
	348	}
	349	put_dev_sector(sect);
	350	printk(" >\n");
	351	#endif
	352	}
	353
	354	/*
	355	* Minix 2.0.0/2.0.2 subpartition support.
	356	* Anand Krishnamurthy <anandk@wiproge.med.ge.com>
	357	* Rajeev V. Pillai <rajeevvp@yahoo.com>
	358	*/
1493bf21 TH	359	static void parse_minix(struct parsed_partitions *state,
1493bf21 TH	360	sector_t offset, sector_t size, int origin)
1da177e4 LT	361	{
	362	#ifdef CONFIG_MINIX_SUBPARTITION
	363	Sector sect;
	364	unsigned char *data;
	365	struct partition *p;
	366	int i;
	367
1493bf21	368	data = read_part_sector(state, offset, &sect);
1da177e4 LT	369	if (!data)
	370	return;
	371
	372	p = (struct partition *)(data + 0x1be);
	373
	374	/* The first sector of a Minix partition can have either
	375	* a secondary MBR describing its subpartitions, or
	376	* the normal boot sector. */
	377	if (msdos_magic_present (data + 510) &&
	378	SYS_IND(p) == MINIX_PARTITION) { /* subpartition table present */
	379
	380	printk(" %s%d: <minix:", state->name, origin);
	381	for (i = 0; i < MINIX_NR_SUBPARTITIONS; i++, p++) {
	382	if (state->next == state->limit)
	383	break;
	384	/* add each partition in use */
	385	if (SYS_IND(p) == MINIX_PARTITION)
	386	put_partition(state, state->next++,
3fbf586c	387	start_sect(p), nr_sects(p));
1da177e4 LT	388	}
	389	printk(" >\n");
	390	}
	391	put_dev_sector(sect);
	392	#endif /* CONFIG_MINIX_SUBPARTITION */
	393	}
	394
	395	static struct {
	396	unsigned char id;
1493bf21	397	void (parse)(struct parsed_partitions , sector_t, sector_t, int);
1da177e4 LT	398	} subtypes[] = {
	399	{FREEBSD_PARTITION, parse_freebsd},
	400	{NETBSD_PARTITION, parse_netbsd},
	401	{OPENBSD_PARTITION, parse_openbsd},
	402	{MINIX_PARTITION, parse_minix},
	403	{UNIXWARE_PARTITION, parse_unixware},
	404	{SOLARIS_X86_PARTITION, parse_solaris_x86},
	405	{NEW_SOLARIS_X86_PARTITION, parse_solaris_x86},
	406	{0, NULL},
	407	};
	408
1493bf21	409	int msdos_partition(struct parsed_partitions *state)
1da177e4	410	{
1493bf21	411	sector_t sector_size = bdev_logical_block_size(state->bdev) / 512;
1da177e4 LT	412	Sector sect;
	413	unsigned char *data;
	414	struct partition *p;
0607fd02	415	struct fat_boot_sector *fb;
1da177e4 LT	416	int slot;
1da177e4 LT	417
1493bf21	418	data = read_part_sector(state, 0, &sect);
1da177e4 LT	419	if (!data)
	420	return -1;
	421	if (!msdos_magic_present(data + 510)) {
	422	put_dev_sector(sect);
	423	return 0;
	424	}
	425
1493bf21	426	if (aix_magic_present(state, data)) {
e1dfa92d OH	427	put_dev_sector(sect);
	428	printk( " [AIX]");
	429	return 0;
	430	}
	431
1da177e4 LT	432	/*
	433	* Now that the 55aa signature is present, this is probably
	434	* either the boot sector of a FAT filesystem or a DOS-type
	435	* partition table. Reject this in case the boot indicator
	436	* is not 0 or 0x80.
	437	*/
	438	p = (struct partition *) (data + 0x1be);
	439	for (slot = 1; slot <= 4; slot++, p++) {
	440	if (p->boot_ind != 0 && p->boot_ind != 0x80) {
0607fd02 FS	441	/*
	442	* Even without a valid boot inidicator value
	443	* its still possible this is valid FAT filesystem
	444	* without a partition table.
	445	*/
	446	fb = (struct fat_boot_sector *) data;
	447	if (slot == 1 && fb->reserved && fb->fats
	448	&& fat_valid_media(fb->media)) {
	449	printk("\n");
	450	put_dev_sector(sect);
	451	return 1;
	452	} else {
	453	put_dev_sector(sect);
	454	return 0;
	455	}
1da177e4 LT	456	}
	457	}
	458
	459	#ifdef CONFIG_EFI_PARTITION
	460	p = (struct partition *) (data + 0x1be);
	461	for (slot = 1 ; slot <= 4 ; slot++, p++) {
	462	/* If this is an EFI GPT disk, msdos should ignore it. */
	463	if (SYS_IND(p) == EFI_PMBR_OSTYPE_EFI_GPT) {
	464	put_dev_sector(sect);
	465	return 0;
	466	}
	467	}
	468	#endif
	469	p = (struct partition *) (data + 0x1be);
	470
	471	/*
	472	* Look for partitions in two passes:
	473	* First find the primary and DOS-type extended partitions.
	474	* On the second pass look inside *BSD, Unixware and Solaris partitions.
	475	*/
	476
	477	state->next = 5;
	478	for (slot = 1 ; slot <= 4 ; slot++, p++) {
3fbf586c DT	479	sector_t start = start_sect(p)*sector_size;
3fbf586c DT	480	sector_t size = nr_sects(p)*sector_size;
1da177e4 LT	481	if (!size)
	482	continue;
	483	if (is_extended_partition(p)) {
8e0cc811 OH	484	/*
	485	* prevent someone doing mkfs or mkswap on an
	486	* extended partition, but leave room for LILO
	487	* FIXME: this uses one logical sector for > 512b
	488	* sector, although it may not be enough/proper.
	489	*/
	490	sector_t n = 2;
	491	n = min(size, max(sector_size, n));
	492	put_partition(state, slot, start, n);
	493
1da177e4	494	printk(" <");
1493bf21	495	parse_extended(state, start, size);
1da177e4 LT	496	printk(" >");
	497	continue;
	498	}
	499	put_partition(state, slot, start, size);
	500	if (SYS_IND(p) == LINUX_RAID_PARTITION)
cc910624	501	state->parts[slot].flags = ADDPART_FLAG_RAID;
1da177e4 LT	502	if (SYS_IND(p) == DM6_PARTITION)
	503	printk("[DM]");
	504	if (SYS_IND(p) == EZD_PARTITION)
	505	printk("[EZD]");
	506	}
	507
	508	printk("\n");
	509
	510	/* second pass - output for each on a separate line */
	511	p = (struct partition *) (0x1be + data);
	512	for (slot = 1 ; slot <= 4 ; slot++, p++) {
	513	unsigned char id = SYS_IND(p);
	514	int n;
	515
3fbf586c	516	if (!nr_sects(p))
1da177e4 LT	517	continue;
	518
	519	for (n = 0; subtypes[n].parse && id != subtypes[n].id; n++)
	520	;
	521
	522	if (!subtypes[n].parse)
	523	continue;
1493bf21 TH	524	subtypes[n].parse(state, start_sect(p) * sector_size,
1493bf21 TH	525	nr_sects(p) * sector_size, slot);
1da177e4 LT	526	}
	527	put_dev_sector(sect);
	528	return 1;
	529	}