1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * fs/partitions/sgi.c
4 *
5 * Code extracted from drivers/block/genhd.c
6 */
7
8 #include "check.h"
9 #include "sgi.h"
10
11 struct sgi_disklabel {
12 __be32 magic_mushroom; /* Big fat spliff... */
13 __be16 root_part_num; /* Root partition number */
14 __be16 swap_part_num; /* Swap partition number */
15 s8 boot_file[16]; /* Name of boot file for ARCS */
16 u8 _unused0[48]; /* Device parameter useless crapola.. */
17 struct sgi_volume {
18 s8 name[8]; /* Name of volume */
19 __be32 block_num; /* Logical block number */
20 __be32 num_bytes; /* How big, in bytes */
21 } volume[15];
22 struct sgi_partition {
23 __be32 num_blocks; /* Size in logical blocks */
24 __be32 first_block; /* First logical block */
25 __be32 type; /* Type of this partition */
26 } partitions[16];
27 __be32 csum; /* Disk label checksum */
28 __be32 _unused1; /* Padding */
29 };
30
31 int sgi_partition(struct parsed_partitions *state)
32 {
33 int i, csum;
34 __be32 magic;
35 int slot = 1;
36 unsigned int start, blocks;
37 __be32 *ui, cs;
38 Sector sect;
39 struct sgi_disklabel *label;
40 struct sgi_partition *p;
41 char b[BDEVNAME_SIZE];
42
43 label = read_part_sector(state, 0, §);
44 if (!label)
45 return -1;
46 p = &label->partitions[0];
47 magic = label->magic_mushroom;
48 if(be32_to_cpu(magic) != SGI_LABEL_MAGIC) {
49 /*printk("Dev %s SGI disklabel: bad magic %08x\n",
50 bdevname(bdev, b), be32_to_cpu(magic));*/
51 put_dev_sector(sect);
52 return 0;
53 }
54 ui = ((__be32 *) (label + 1)) - 1;
55 for(csum = 0; ui >= ((__be32 *) label);) {
56 cs = *ui--;
57 csum += be32_to_cpu(cs);
58 }
59 if(csum) {
60 printk(KERN_WARNING "Dev %s SGI disklabel: csum bad, label corrupted\n",
61 bdevname(state->bdev, b));
62 put_dev_sector(sect);
63 return 0;
64 }
65 /* All SGI disk labels have 16 partitions, disks under Linux only
66 * have 15 minor's. Luckily there are always a few zero length
67 * partitions which we don't care about so we never overflow the
68 * current_minor.
69 */
70 for(i = 0; i < 16; i++, p++) {
71 blocks = be32_to_cpu(p->num_blocks);
72 start = be32_to_cpu(p->first_block);
73 if (blocks) {
74 put_partition(state, slot, start, blocks);
75 if (be32_to_cpu(p->type) == LINUX_RAID_PARTITION)
76 state->parts[slot].flags = ADDPART_FLAG_RAID;
77 }
78 slot++;
79 }
80 strlcat(state->pp_buf, "\n", PAGE_SIZE);
81 put_dev_sector(sect);
82 return 1;
83 }