[RESUBMIT PATCH] msdos: add support for large disks
From: Daniel Taylor
Date: Tue Mar 02 2010 - 17:49:46 EST
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".
Signed-off-by: Daniel Taylor <daniel.taylor@xxxxxxx> diff --git
a/fs/partitions/msdos.c b/fs/partitions/msdos.c index 0028d2e..039bb61
100644
--- a/fs/partitions/msdos.c
+++ b/fs/partitions/msdos.c
@@ -32,13 +32,20 @@
#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 START_SECT(p) ({ __le32 __a = get_unaligned(&p->start_sect); \
- le32_to_cpu(__a); \
- })
+static inline sector_t nr_sects(struct partition *p) {
+ u32 number_of_sectors = le32_to_cpu(get_unaligned(&p->nr_sects));
+
+ return (sector_t)number_of_sectors;
+}
+
+static inline sector_t start_sect(struct partition *p) {
+ u32 start_sector = le32_to_cpu(get_unaligned(&p->start_sect));
+
+ return (sector_t)start_sector;
+}
static inline int is_extended_partition(struct partition *p) { @@ -104,13
+111,13 @@ 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 +152,14 @@ 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 +186,13 @@ 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 +204,7 @@ 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 +251,7 @@ 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 +270,7 @@ 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 +297,7 @@ 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 +307,7 @@
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 +317,7 @@
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 +331,7 @@
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 +355,8 @@ 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));
+ start_sect((struct partition *)p),
+ nr_sects((struct partition *)p));
p++;
}
put_dev_sector(sect);
@@ -363,7 +371,7 @@ 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 +398,7 @@ 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 +409,7 @@ 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 +423,7 @@ 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 +491,8 @@ 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 +521,7 @@ 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 +529,8 @@ 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;
--
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