fs/partitions/ldm.c: fix oops caused by corrupted partition table
[linux-2.6.git] / fs / partitions / mac.c
1 /*
2  *  fs/partitions/mac.c
3  *
4  *  Code extracted from drivers/block/genhd.c
5  *  Copyright (C) 1991-1998  Linus Torvalds
6  *  Re-organised Feb 1998 Russell King
7  */
8
9 #include <linux/ctype.h>
10 #include "check.h"
11 #include "mac.h"
12
13 #ifdef CONFIG_PPC_PMAC
14 #include <asm/machdep.h>
15 extern void note_bootable_part(dev_t dev, int part, int goodness);
16 #endif
17
18 /*
19  * Code to understand MacOS partition tables.
20  */
21
22 static inline void mac_fix_string(char *stg, int len)
23 {
24         int i;
25
26         for (i = len - 1; i >= 0 && stg[i] == ' '; i--)
27                 stg[i] = 0;
28 }
29
30 int mac_partition(struct parsed_partitions *state)
31 {
32         Sector sect;
33         unsigned char *data;
34         int slot, blocks_in_map;
35         unsigned secsize;
36 #ifdef CONFIG_PPC_PMAC
37         int found_root = 0;
38         int found_root_goodness = 0;
39 #endif
40         struct mac_partition *part;
41         struct mac_driver_desc *md;
42
43         /* Get 0th block and look at the first partition map entry. */
44         md = read_part_sector(state, 0, &sect);
45         if (!md)
46                 return -1;
47         if (be16_to_cpu(md->signature) != MAC_DRIVER_MAGIC) {
48                 put_dev_sector(sect);
49                 return 0;
50         }
51         secsize = be16_to_cpu(md->block_size);
52         put_dev_sector(sect);
53         data = read_part_sector(state, secsize/512, &sect);
54         if (!data)
55                 return -1;
56         part = (struct mac_partition *) (data + secsize%512);
57         if (be16_to_cpu(part->signature) != MAC_PARTITION_MAGIC) {
58                 put_dev_sector(sect);
59                 return 0;               /* not a MacOS disk */
60         }
61         blocks_in_map = be32_to_cpu(part->map_count);
62         if (blocks_in_map < 0 || blocks_in_map >= DISK_MAX_PARTS) {
63                 put_dev_sector(sect);
64                 return 0;
65         }
66         strlcat(state->pp_buf, " [mac]", PAGE_SIZE);
67         for (slot = 1; slot <= blocks_in_map; ++slot) {
68                 int pos = slot * secsize;
69                 put_dev_sector(sect);
70                 data = read_part_sector(state, pos/512, &sect);
71                 if (!data)
72                         return -1;
73                 part = (struct mac_partition *) (data + pos%512);
74                 if (be16_to_cpu(part->signature) != MAC_PARTITION_MAGIC)
75                         break;
76                 put_partition(state, slot,
77                         be32_to_cpu(part->start_block) * (secsize/512),
78                         be32_to_cpu(part->block_count) * (secsize/512));
79
80                 if (!strnicmp(part->type, "Linux_RAID", 10))
81                         state->parts[slot].flags = ADDPART_FLAG_RAID;
82 #ifdef CONFIG_PPC_PMAC
83                 /*
84                  * If this is the first bootable partition, tell the
85                  * setup code, in case it wants to make this the root.
86                  */
87                 if (machine_is(powermac)) {
88                         int goodness = 0;
89
90                         mac_fix_string(part->processor, 16);
91                         mac_fix_string(part->name, 32);
92                         mac_fix_string(part->type, 32);                                 
93                     
94                         if ((be32_to_cpu(part->status) & MAC_STATUS_BOOTABLE)
95                             && strcasecmp(part->processor, "powerpc") == 0)
96                                 goodness++;
97
98                         if (strcasecmp(part->type, "Apple_UNIX_SVR2") == 0
99                             || (strnicmp(part->type, "Linux", 5) == 0
100                                 && strcasecmp(part->type, "Linux_swap") != 0)) {
101                                 int i, l;
102
103                                 goodness++;
104                                 l = strlen(part->name);
105                                 if (strcmp(part->name, "/") == 0)
106                                         goodness++;
107                                 for (i = 0; i <= l - 4; ++i) {
108                                         if (strnicmp(part->name + i, "root",
109                                                      4) == 0) {
110                                                 goodness += 2;
111                                                 break;
112                                         }
113                                 }
114                                 if (strnicmp(part->name, "swap", 4) == 0)
115                                         goodness--;
116                         }
117
118                         if (goodness > found_root_goodness) {
119                                 found_root = slot;
120                                 found_root_goodness = goodness;
121                         }
122                 }
123 #endif /* CONFIG_PPC_PMAC */
124         }
125 #ifdef CONFIG_PPC_PMAC
126         if (found_root_goodness)
127                 note_bootable_part(state->bdev->bd_dev, found_root,
128                                    found_root_goodness);
129 #endif
130
131         put_dev_sector(sect);
132         strlcat(state->pp_buf, "\n", PAGE_SIZE);
133         return 1;
134 }