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 char b[BDEVNAME_SIZE]; 47 48 label = read_part_sector(state, 0, §); 49 if (!label) 50 return -1; 51 p = &label->partitions[0]; 52 magic = label->magic_mushroom; 53 if(be32_to_cpu(magic) != SGI_LABEL_MAGIC) { 54 /*printk("Dev %s SGI disklabel: bad magic %08x\n", 55 bdevname(bdev, b), be32_to_cpu(magic));*/ 56 put_dev_sector(sect); 57 return 0; 58 } 59 ui = ((__be32 *) (label + 1)) - 1; 60 for(csum = 0; ui >= ((__be32 *) label);) { 61 cs = *ui--; 62 csum += be32_to_cpu(cs); 63 } 64 if(csum) { 65 printk(KERN_WARNING "Dev %s SGI disklabel: csum bad, label corrupted\n", 66 bdevname(state->bdev, b)); 67 put_dev_sector(sect); 68 return 0; 69 } 70 /* All SGI disk labels have 16 partitions, disks under Linux only 71 * have 15 minor's. Luckily there are always a few zero length 72 * partitions which we don't care about so we never overflow the 73 * current_minor. 74 */ 75 for(i = 0; i < 16; i++, p++) { 76 blocks = be32_to_cpu(p->num_blocks); 77 start = be32_to_cpu(p->first_block); 78 if (blocks) { 79 put_partition(state, slot, start, blocks); 80 if (be32_to_cpu(p->type) == LINUX_RAID_PARTITION) 81 state->parts[slot].flags = ADDPART_FLAG_RAID; 82 } 83 slot++; 84 } 85 strlcat(state->pp_buf, "\n", PAGE_SIZE); 86 put_dev_sector(sect); 87 return 1; 88 } 89