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
10 #define SGI_LABEL_MAGIC 0x0be5a941
11
12 enum {
13 LINUX_RAID_PARTITION = 0xfd, /* autodetect RAID partition */
14 };
15
16 struct sgi_disklabel {
17 __be32 magic_mushroom; /* Big fat spliff... */
18 __be16 root_part_num; /* Root partition number */
19 __be16 swap_part_num; /* Swap partition number */
20 s8 boot_file[16]; /* Name of boot file for ARCS */
21 u8 _unused0[48]; /* Device parameter useless crapola.. */
22 struct sgi_volume {
23 s8 name[8]; /* Name of volume */
24 __be32 block_num; /* Logical block number */
25 __be32 num_bytes; /* How big, in bytes */
26 } volume[15];
27 struct sgi_partition {
28 __be32 num_blocks; /* Size in logical blocks */
29 __be32 first_block; /* First logical block */
30 __be32 type; /* Type of this partition */
31 } partitions[16];
32 __be32 csum; /* Disk label checksum */
33 __be32 _unused1; /* Padding */
34 };
35
36 int sgi_partition(struct parsed_partitions *state)
37 {
38 int i, csum;
39 __be32 magic;
40 int slot = 1;
41 unsigned int start, blocks;
42 __be32 *ui, cs;
43 Sector sect;
44 struct sgi_disklabel *label;
45 struct sgi_partition *p;
46
47 label = read_part_sector(state, 0, §);
48 if (!label)
49 return -1;
50 p = &label->partitions[0];
51 magic = label->magic_mushroom;
52 if(be32_to_cpu(magic) != SGI_LABEL_MAGIC) {
53 /*printk("Dev %s SGI disklabel: bad magic %08x\n",
54 state->disk->disk_name, be32_to_cpu(magic));*/
55 put_dev_sector(sect);
56 return 0;
57 }
58 ui = ((__be32 *) (label + 1)) - 1;
59 for(csum = 0; ui >= ((__be32 *) label);) {
60 cs = *ui--;
61 csum += be32_to_cpu(cs);
62 }
63 if(csum) {
64 printk(KERN_WARNING "Dev %s SGI disklabel: csum bad, label corrupted\n",
65 state->disk->disk_name);
66 put_dev_sector(sect);
67 return 0;
68 }
69 /* All SGI disk labels have 16 partitions, disks under Linux only
70 * have 15 minor's. Luckily there are always a few zero length
71 * partitions which we don't care about so we never overflow the
72 * current_minor.
73 */
74 for(i = 0; i < 16; i++, p++) {
75 blocks = be32_to_cpu(p->num_blocks);
76 start = be32_to_cpu(p->first_block);
77 if (blocks) {
78 put_partition(state, slot, start, blocks);
79 if (be32_to_cpu(p->type) == LINUX_RAID_PARTITION)
80 state->parts[slot].flags = ADDPART_FLAG_RAID;
81 }
82 slot++;
83 }
84 strlcat(state->pp_buf, "\n", PAGE_SIZE);
85 put_dev_sector(sect);
86 return 1;
87 }
88
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