sun.c
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上传日期:2013-04-10
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文件大小:3k
- /*
- * fs/partitions/sun.c
- *
- * Code extracted from drivers/block/genhd.c
- *
- * Copyright (C) 1991-1998 Linus Torvalds
- * Re-organised Feb 1998 Russell King
- */
- #include <linux/config.h>
- #include <linux/fs.h>
- #include <linux/genhd.h>
- #include <linux/kernel.h>
- #include <linux/major.h>
- #include <linux/string.h>
- #include <linux/blk.h>
- #include <asm/system.h>
- #include "check.h"
- #include "sun.h"
- #ifdef CONFIG_BLK_DEV_MD
- extern void md_autodetect_dev(kdev_t dev);
- #endif
- int sun_partition(struct gendisk *hd, struct block_device *bdev, unsigned long first_sector, int first_part_minor)
- {
- int i, csum;
- unsigned short *ush;
- Sector sect;
- kdev_t dev = to_kdev_t(bdev->bd_dev);
- 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. */
- unsigned short rspeed; /* Disk rotational speed */
- unsigned short pcylcount; /* Physical cylinder count */
- unsigned short sparecyl; /* extra sects per cylinder */
- unsigned char spare2[4]; /* More magic... */
- unsigned short ilfact; /* Interleave factor */
- unsigned short ncyl; /* Data cylinder count */
- unsigned short nacyl; /* Alt. cylinder count */
- unsigned short ntrks; /* Tracks per cylinder */
- unsigned short nsect; /* Sectors per track */
- unsigned char spare3[4]; /* Even more magic... */
- struct sun_partition {
- __u32 start_cylinder;
- __u32 num_sectors;
- } partitions[8];
- unsigned short magic; /* Magic number */
- unsigned short csum; /* Label xor'd checksum */
- } * label;
- struct sun_partition *p;
- unsigned long spc;
- label = (struct sun_disklabel *)read_dev_sector(bdev, 0, §);
- 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 %04xn",
- bdevname(dev), be16_to_cpu(label->magic)); */
- put_dev_sector(sect);
- return 0;
- }
- /* Look at the checksum */
- ush = ((unsigned short *) (label+1)) - 1;
- for (csum = 0; ush >= ((unsigned short *) label);)
- csum ^= *ush--;
- if (csum) {
- printk("Dev %s Sun disklabel: Csum bad, label corruptedn",
- bdevname(dev));
- 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;
- int num_sectors;
- st_sector = first_sector + be32_to_cpu(p->start_cylinder) * spc;
- num_sectors = be32_to_cpu(p->num_sectors);
- if (num_sectors) {
- add_gd_partition(hd, first_part_minor,
- st_sector, num_sectors);
- #ifdef CONFIG_BLK_DEV_MD
- if (label->infos[i].id == LINUX_RAID_PARTITION)
- md_autodetect_dev(MKDEV(hd->major,
- first_part_minor));
- #endif
- }
- first_part_minor++;
- }
- printk("n");
- put_dev_sector(sect);
- return 1;
- }