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linux/fs/partitions/sun.c
Fabio Massimo Di Nitto d18d7682c1 [PARTITION]: Add whole_disk attribute.
Some partitioning systems create special partitions that
span the entire disk.  One example are Sun partitions, and
this whole-disk partition exists to tell the firmware the
extent of the entire device so it can load the boot block
and do other things.

Such partitions should not be treated as normal partitions,
because all the other partitions overlap this whole-disk one.
So we'd see multiple instances of the same UUID etc. which
we do not want.  udev and friends can thus search for this
'whole_disk' attribute and use it to decide to ignore the
partition.

Signed-off-by: Fabio Massimo Di Nitto <fabbione@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-10 23:50:00 -08:00

95 lines
2.6 KiB
C

/*
* fs/partitions/sun.c
*
* Code extracted from drivers/block/genhd.c
*
* Copyright (C) 1991-1998 Linus Torvalds
* Re-organised Feb 1998 Russell King
*/
#include "check.h"
#include "sun.h"
int sun_partition(struct parsed_partitions *state, struct block_device *bdev)
{
int i;
__be16 csum;
int slot = 1;
__be16 *ush;
Sector sect;
struct sun_disklabel {
unsigned char info[128]; /* Informative text string */
unsigned char spare0[14];
struct sun_info {
unsigned char spare1;
unsigned char id;
unsigned char spare2;
unsigned char flags;
} infos[8];
unsigned char spare[246]; /* Boot information etc. */
__be16 rspeed; /* Disk rotational speed */
__be16 pcylcount; /* Physical cylinder count */
__be16 sparecyl; /* extra sects per cylinder */
unsigned char spare2[4]; /* More magic... */
__be16 ilfact; /* Interleave factor */
__be16 ncyl; /* Data cylinder count */
__be16 nacyl; /* Alt. cylinder count */
__be16 ntrks; /* Tracks per cylinder */
__be16 nsect; /* Sectors per track */
unsigned char spare3[4]; /* Even more magic... */
struct sun_partition {
__be32 start_cylinder;
__be32 num_sectors;
} partitions[8];
__be16 magic; /* Magic number */
__be16 csum; /* Label xor'd checksum */
} * label;
struct sun_partition *p;
unsigned long spc;
char b[BDEVNAME_SIZE];
label = (struct sun_disklabel *)read_dev_sector(bdev, 0, &sect);
if (!label)
return -1;
p = label->partitions;
if (be16_to_cpu(label->magic) != SUN_LABEL_MAGIC) {
/* printk(KERN_INFO "Dev %s Sun disklabel: bad magic %04x\n",
bdevname(bdev, b), be16_to_cpu(label->magic)); */
put_dev_sector(sect);
return 0;
}
/* Look at the checksum */
ush = ((__be16 *) (label+1)) - 1;
for (csum = 0; ush >= ((__be16 *) label);)
csum ^= *ush--;
if (csum) {
printk("Dev %s Sun disklabel: Csum bad, label corrupted\n",
bdevname(bdev, b));
put_dev_sector(sect);
return 0;
}
/* All Sun disks have 8 partition entries */
spc = be16_to_cpu(label->ntrks) * be16_to_cpu(label->nsect);
for (i = 0; i < 8; i++, p++) {
unsigned long st_sector;
unsigned int num_sectors;
st_sector = be32_to_cpu(p->start_cylinder) * spc;
num_sectors = be32_to_cpu(p->num_sectors);
if (num_sectors) {
put_partition(state, slot, st_sector, num_sectors);
state->parts[slot].flags = 0;
if (label->infos[i].id == LINUX_RAID_PARTITION)
state->parts[slot].flags |= ADDPART_FLAG_RAID;
if (label->infos[i].id == SUN_WHOLE_DISK)
state->parts[slot].flags |= ADDPART_FLAG_WHOLEDISK;
}
slot++;
}
printk("\n");
put_dev_sector(sect);
return 1;
}