fs/block_dev.c: fix performance regression in O_DIRECT|O_SYNC writes to block devices
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / partitions / ultrix.c
blobec852c11dce48fd1e564e0e9085ca8c0ad04bb02
1 /*
2 * fs/partitions/ultrix.c
4 * Code extracted from drivers/block/genhd.c
6 * Re-organised Jul 1999 Russell King
7 */
9 #include "check.h"
10 #include "ultrix.h"
12 int ultrix_partition(struct parsed_partitions *state, struct block_device *bdev)
14 int i;
15 Sector sect;
16 unsigned char *data;
17 struct ultrix_disklabel {
18 s32 pt_magic; /* magic no. indicating part. info exits */
19 s32 pt_valid; /* set by driver if pt is current */
20 struct pt_info {
21 s32 pi_nblocks; /* no. of sectors */
22 u32 pi_blkoff; /* block offset for start */
23 } pt_part[8];
24 } *label;
26 #define PT_MAGIC 0x032957 /* Partition magic number */
27 #define PT_VALID 1 /* Indicates if struct is valid */
29 data = read_dev_sector(bdev, (16384 - sizeof(*label))/512, &sect);
30 if (!data)
31 return -1;
33 label = (struct ultrix_disklabel *)(data + 512 - sizeof(*label));
35 if (label->pt_magic == PT_MAGIC && label->pt_valid == PT_VALID) {
36 for (i=0; i<8; i++)
37 if (label->pt_part[i].pi_nblocks)
38 put_partition(state, i+1,
39 label->pt_part[i].pi_blkoff,
40 label->pt_part[i].pi_nblocks);
41 put_dev_sector(sect);
42 printk ("\n");
43 return 1;
44 } else {
45 put_dev_sector(sect);
46 return 0;