block/partitions/check.c

   1 /*
   2  *  fs/partitions/check.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  *  We now have independent partition support from the
   9  *  block drivers, which allows all the partition code to
  10  *  be grouped in one location, and it to be mostly self
  11  *  contained.
  12  *
  13  *  Added needed MAJORS for new pairs, {hdi,hdj}, {hdk,hdl}
  14  */
  15
  16 #include <linux/slab.h>
  17 #include <linux/vmalloc.h>
  18 #include <linux/ctype.h>
  19 #include <linux/genhd.h>
  20
  21 #include "check.h"
  22
  23 #include "acorn.h"
  24 #include "amiga.h"
  25 #include "atari.h"
  26 #include "ldm.h"
  27 #include "mac.h"
  28 #include "msdos.h"
  29 #include "osf.h"
  30 #include "sgi.h"
  31 #include "sun.h"
  32 #include "ibm.h"
  33 #include "ultrix.h"
  34 #include "efi.h"
  35 #include "karma.h"
  36 #include "sysv68.h"
  37 #include "cmdline.h"
  38
  39 int warn_no_part = 1; /*This is ugly: should make genhd removable media aware*/
  40
  41 static int (*check_part[])(struct parsed_partitions *) = {
  42         /*
  43          * Probe partition formats with tables at disk address 0
  44          * that also have an ADFS boot block at 0xdc0.
  45          */
  46 #ifdef CONFIG_ACORN_PARTITION_ICS
  47         adfspart_check_ICS,
  48 #endif
  49 #ifdef CONFIG_ACORN_PARTITION_POWERTEC
  50         adfspart_check_POWERTEC,
  51 #endif
  52 #ifdef CONFIG_ACORN_PARTITION_EESOX
  53         adfspart_check_EESOX,
  54 #endif
  55
  56         /*
  57          * Now move on to formats that only have partition info at
  58          * disk address 0xdc0.  Since these may also have stale
  59          * PC/BIOS partition tables, they need to come before
  60          * the msdos entry.
  61          */
  62 #ifdef CONFIG_ACORN_PARTITION_CUMANA
  63         adfspart_check_CUMANA,
  64 #endif
  65 #ifdef CONFIG_ACORN_PARTITION_ADFS
  66         adfspart_check_ADFS,
  67 #endif
  68
  69 #ifdef CONFIG_CMDLINE_PARTITION
  70         cmdline_partition,
  71 #endif
  72 #ifdef CONFIG_EFI_PARTITION
  73         efi_partition,          /* this must come before msdos */
  74 #endif
  75 #ifdef CONFIG_SGI_PARTITION
  76         sgi_partition,
  77 #endif
  78 #ifdef CONFIG_LDM_PARTITION
  79         ldm_partition,          /* this must come before msdos */
  80 #endif
  81 #ifdef CONFIG_MSDOS_PARTITION
  82         msdos_partition,
  83 #endif
  84 #ifdef CONFIG_OSF_PARTITION
  85         osf_partition,
  86 #endif
  87 #ifdef CONFIG_SUN_PARTITION
  88         sun_partition,
  89 #endif
  90 #ifdef CONFIG_AMIGA_PARTITION
  91         amiga_partition,
  92 #endif
  93 #ifdef CONFIG_ATARI_PARTITION
  94         atari_partition,
  95 #endif
  96 #ifdef CONFIG_MAC_PARTITION
  97         mac_partition,
  98 #endif
  99 #ifdef CONFIG_ULTRIX_PARTITION
 100         ultrix_partition,
 101 #endif
 102 #ifdef CONFIG_IBM_PARTITION
 103         ibm_partition,
 104 #endif
 105 #ifdef CONFIG_KARMA_PARTITION
 106         karma_partition,
 107 #endif
 108 #ifdef CONFIG_SYSV68_PARTITION
 109         sysv68_partition,
 110 #endif
 111         NULL
 112 };
 113
 114 static struct parsed_partitions *allocate_partitions(struct gendisk *hd)
 115 {
 116         struct parsed_partitions *state;
 117         int nr;
 118
 119         state = kzalloc(sizeof(*state), GFP_KERNEL);
 120         if (!state)
 121                 return NULL;
 122
 123         nr = disk_max_parts(hd);
 124         state->parts = vzalloc(nr * sizeof(state->parts[0]));
 125         if (!state->parts) {
 126                 kfree(state);
 127                 return NULL;
 128         }
 129
 130         state->limit = nr;
 131
 132         return state;
 133 }
 134
 135 void free_partitions(struct parsed_partitions *state)
 136 {
 137         vfree(state->parts);
 138         kfree(state);
 139 }
 140
 141 struct parsed_partitions *
 142 check_partition(struct gendisk *hd, struct block_device *bdev)
 143 {
 144         struct parsed_partitions *state;
 145         int i, res, err;
 146
 147         state = allocate_partitions(hd);
 148         if (!state)
 149                 return NULL;
 150         state->pp_buf = (char *)__get_free_page(GFP_KERNEL);
 151         if (!state->pp_buf) {
 152                 free_partitions(state);
 153                 return NULL;
 154         }
 155         state->pp_buf[0] = '\0';
 156
 157         state->bdev = bdev;
 158         disk_name(hd, 0, state->name);
 159         snprintf(state->pp_buf, PAGE_SIZE, " %s:", state->name);
 160         if (isdigit(state->name[strlen(state->name)-1]))
 161                 sprintf(state->name, "p");
 162
 163         i = res = err = 0;
 164         while (!res && check_part[i]) {
 165                 memset(state->parts, 0, state->limit * sizeof(state->parts[0]));
 166                 res = check_part[i++](state);
 167                 if (res < 0) {
 168                         /* We have hit an I/O error which we don't report now.
 169                         * But record it, and let the others do their job.
 170                         */
 171                         err = res;
 172                         res = 0;
 173                 }
 174
 175         }
 176         if (res > 0) {
 177                 printk(KERN_INFO "%s", state->pp_buf);
 178
 179                 free_page((unsigned long)state->pp_buf);
 180                 return state;
 181         }
 182         if (state->access_beyond_eod)
 183                 err = -ENOSPC;
 184         if (err)
 185         /* The partition is unrecognized. So report I/O errors if there were any */
 186                 res = err;
 187         if (res) {
 188                 if (warn_no_part)
 189                         strlcat(state->pp_buf,
 190                                 " unable to read partition table\n", PAGE_SIZE);
 191                 printk(KERN_INFO "%s", state->pp_buf);
 192         }
 193
 194         free_page((unsigned long)state->pp_buf);
 195         free_partitions(state);
 196         return ERR_PTR(res);
 197 }