Commit 3fbf586c authored by Daniel Taylor's avatar Daniel Taylor Committed by Linus Torvalds
Browse files

fs/partitions/msdos: add support for large disks 



In order to use disks larger than 2TiB on Windows XP, it is necessary to
use 4096-byte logical sectors in an MBR.

Although the kernel storage and functions called from msdos.c used
"sector_t" internally, msdos.c still used u32 variables, which results in
the ability to handle XP-compatible large disks.

This patch changes the internal variables to "sector_t".

Daniel said: "In the near future, WD will be releasing products that need
this patch".

[hirofumi@mail.parknet.co.jp: tweaks and fix]
Signed-off-by: default avatarDaniel Taylor <daniel.taylor@wdc.com>
Signed-off-by: default avatarOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <stable@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b5c26f97

fs/partitions/msdos.c

+38 −34
Original line number Diff line number Diff line
@@ -31,14 +31,17 @@ 
 */

#include <asm/unaligned.h>



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

#define NR_SECTS(p)	({ __le32 __a =	get_unaligned(&p->nr_sects);	\

				le32_to_cpu(__a); \

			})

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



#define START_SECT(p)	({ __le32 __a =	get_unaligned(&p->start_sect);	\

				le32_to_cpu(__a); \

			})

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)

{
@@ -104,13 +107,13 @@ static int aix_magic_present(unsigned char *p, struct block_device *bdev) 


static void

parse_extended(struct parsed_partitions *state, struct block_device *bdev,

			u32 first_sector, u32 first_size)

			sector_t first_sector, sector_t first_size)

{

	struct partition *p;

	Sector sect;

	unsigned char *data;

	u32 this_sector, this_size;

	int sector_size = bdev_logical_block_size(bdev) / 512;

	sector_t this_sector, this_size;

	sector_t sector_size = bdev_logical_block_size(bdev) / 512;

	int loopct = 0;		/* number of links followed

				   without finding a data partition */

	int i;
@@ -145,14 +148,14 @@ parse_extended(struct parsed_partitions *state, struct block_device *bdev, 
		 * First process the data partition(s)

		 */

		for (i=0; i<4; i++, p++) {

			u32 offs, size, next;

			if (!NR_SECTS(p) || is_extended_partition(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;

			offs = start_sect(p)*sector_size;

			size = nr_sects(p)*sector_size;

			next = this_sector + offs;

			if (i >= 2) {

				if (offs + size > this_size)
@@ -179,13 +182,13 @@ parse_extended(struct parsed_partitions *state, struct block_device *bdev, 
		 */

		p -= 4;

		for (i=0; i<4; i++, p++)

			if (NR_SECTS(p) && is_extended_partition(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;

		this_sector = first_sector + start_sect(p) * sector_size;

		this_size = nr_sects(p) * sector_size;

		put_dev_sector(sect);

	}

done:
@@ -197,7 +200,7 @@ done: 


static void

parse_solaris_x86(struct parsed_partitions *state, struct block_device *bdev,

			u32 offset, u32 size, int origin)

			sector_t offset, sector_t size, int origin)

{

#ifdef CONFIG_SOLARIS_X86_PARTITION

	Sector sect;
@@ -244,7 +247,7 @@ parse_solaris_x86(struct parsed_partitions *state, struct block_device *bdev, 
 */

static void

parse_bsd(struct parsed_partitions *state, struct block_device *bdev,

		u32 offset, u32 size, int origin, char *flavour,

		sector_t offset, sector_t size, int origin, char *flavour,

		int max_partitions)

{

	Sector sect;
@@ -263,7 +266,7 @@ parse_bsd(struct parsed_partitions *state, struct block_device *bdev, 
	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++) {

		u32 bsd_start, bsd_size;

		sector_t bsd_start, bsd_size;



		if (state->next == state->limit)

			break;
@@ -290,7 +293,7 @@ parse_bsd(struct parsed_partitions *state, struct block_device *bdev, 


static void

parse_freebsd(struct parsed_partitions *state, struct block_device *bdev,

		u32 offset, u32 size, int origin)

		sector_t offset, sector_t size, int origin)

{

#ifdef CONFIG_BSD_DISKLABEL

	parse_bsd(state, bdev, offset, size, origin,
@@ -300,7 +303,7 @@ parse_freebsd(struct parsed_partitions *state, struct block_device *bdev, 


static void

parse_netbsd(struct parsed_partitions *state, struct block_device *bdev,

		u32 offset, u32 size, int origin)

		sector_t offset, sector_t size, int origin)

{

#ifdef CONFIG_BSD_DISKLABEL

	parse_bsd(state, bdev, offset, size, origin,
@@ -310,7 +313,7 @@ parse_netbsd(struct parsed_partitions *state, struct block_device *bdev, 


static void

parse_openbsd(struct parsed_partitions *state, struct block_device *bdev,

		u32 offset, u32 size, int origin)

		sector_t offset, sector_t size, int origin)

{

#ifdef CONFIG_BSD_DISKLABEL

	parse_bsd(state, bdev, offset, size, origin,
@@ -324,7 +327,7 @@ parse_openbsd(struct parsed_partitions *state, struct block_device *bdev, 
 */

static void

parse_unixware(struct parsed_partitions *state, struct block_device *bdev,

		u32 offset, u32 size, int origin)

		sector_t offset, sector_t size, int origin)

{

#ifdef CONFIG_UNIXWARE_DISKLABEL

	Sector sect;
@@ -348,7 +351,8 @@ parse_unixware(struct parsed_partitions *state, struct block_device *bdev, 


		if (p->s_label != UNIXWARE_FS_UNUSED)

			put_partition(state, state->next++,

						START_SECT(p), NR_SECTS(p));

				      le32_to_cpu(p->start_sect),

				      le32_to_cpu(p->nr_sects));

		p++;

	}

	put_dev_sector(sect);
@@ -363,7 +367,7 @@ parse_unixware(struct parsed_partitions *state, struct block_device *bdev, 
 */

static void

parse_minix(struct parsed_partitions *state, struct block_device *bdev,

		u32 offset, u32 size, int origin)

		sector_t offset, sector_t size, int origin)

{

#ifdef CONFIG_MINIX_SUBPARTITION

	Sector sect;
@@ -390,7 +394,7 @@ parse_minix(struct parsed_partitions *state, struct block_device *bdev, 
			/* add each partition in use */

			if (SYS_IND(p) == MINIX_PARTITION)

				put_partition(state, state->next++,

					      START_SECT(p), NR_SECTS(p));

					      start_sect(p), nr_sects(p));

		}

		printk(" >\n");

	}
@@ -401,7 +405,7 @@ parse_minix(struct parsed_partitions *state, struct block_device *bdev, 
static struct {

	unsigned char id;

	void (*parse)(struct parsed_partitions *, struct block_device *,

			u32, u32, int);

			sector_t, sector_t, int);

} subtypes[] = {

	{FREEBSD_PARTITION, parse_freebsd},

	{NETBSD_PARTITION, parse_netbsd},
@@ -415,7 +419,7 @@ static struct { 
 

int msdos_partition(struct parsed_partitions *state, struct block_device *bdev)

{

	int sector_size = bdev_logical_block_size(bdev) / 512;

	sector_t sector_size = bdev_logical_block_size(bdev) / 512;

	Sector sect;

	unsigned char *data;

	struct partition *p;
@@ -483,8 +487,8 @@ int msdos_partition(struct parsed_partitions *state, struct block_device *bdev) 


	state->next = 5;

	for (slot = 1 ; slot <= 4 ; slot++, p++) {

		u32 start = START_SECT(p)*sector_size;

		u32 size = NR_SECTS(p)*sector_size;

		sector_t start = start_sect(p)*sector_size;

		sector_t size = nr_sects(p)*sector_size;

		if (!size)

			continue;

		if (is_extended_partition(p)) {
@@ -513,7 +517,7 @@ int msdos_partition(struct parsed_partitions *state, struct block_device *bdev) 
		unsigned char id = SYS_IND(p);

		int n;



		if (!NR_SECTS(p))

		if (!nr_sects(p))

			continue;



		for (n = 0; subtypes[n].parse && id != subtypes[n].id; n++)
@@ -521,8 +525,8 @@ int msdos_partition(struct parsed_partitions *state, struct block_device *bdev) 


		if (!subtypes[n].parse)

			continue;

		subtypes[n].parse(state, bdev, START_SECT(p)*sector_size,

						NR_SECTS(p)*sector_size, slot);

		subtypes[n].parse(state, bdev, start_sect(p)*sector_size,

						nr_sects(p)*sector_size, slot);

	}

	put_dev_sector(sect);

	return 1;

CRA Git | Maintained and supported by SUSTech CRA and CCSE