arch/common/boot/grub2/disk/raid5_recover.c

   1 /* raid5_recover.c - module to recover from faulty RAID4/5 arrays.  */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2006,2007,2008  Free Software Foundation, Inc.
   5  *
   6  *  GRUB is free software: you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation, either version 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  GRUB is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <grub/dl.h>
  21 #include <grub/disk.h>
  22 #include <grub/mm.h>
  23 #include <grub/err.h>
  24 #include <grub/misc.h>
  25 #include <grub/raid.h>
  26
  27 static grub_err_t
  28 grub_raid5_recover (struct grub_raid_array *array, int disknr,
  29                     char *buf, grub_disk_addr_t sector, int size)
  30 {
  31   char *buf2;
  32   int i;
  33
  34   size <<= GRUB_DISK_SECTOR_BITS;
  35   buf2 = grub_malloc (size);
  36   if (!buf2)
  37     return grub_errno;
  38
  39   grub_memset (buf, 0, size);
  40
  41   for (i = 0; i < (int) array->total_devs; i++)
  42     {
  43       grub_err_t err;
  44
  45       if (i == disknr)
  46         continue;
  47
  48       err = grub_disk_read (array->device[i], sector, 0, size, buf2);
  49
  50       if (err)
  51         {
  52           grub_free (buf2);
  53           return err;
  54         }
  55
  56       grub_raid_block_xor (buf, buf2, size);
  57     }
  58
  59   grub_free (buf2);
  60
  61   return GRUB_ERR_NONE;
  62 }
  63
  64 GRUB_MOD_INIT(raid5rec)
  65 {
  66   grub_raid5_recover_func = grub_raid5_recover;
  67 }
  68
  69 GRUB_MOD_FINI(raid5rec)
  70 {
  71   grub_raid5_recover_func = 0;
  72 }