e2fsck/super.c

   1 /*
   2  * e2fsck.c - superblock checks
   3  *
   4  * Copyright (C) 1993, 1994, 1995, 1996, 1997 Theodore Ts'o.
   5  *
   6  * %Begin-Header%
   7  * This file may be redistributed under the terms of the GNU Public
   8  * License.
   9  * %End-Header%
  10  */
  11
  12 #ifdef HAVE_ERRNO_H
  13 #include <errno.h>
  14 #endif
  15
  16 #ifndef EXT2_SKIP_UUID
  17 #include "uuid/uuid.h"
  18 #endif
  19 #include "e2fsck.h"
  20 #include "problem.h"
  21
  22 #define MIN_CHECK 1
  23 #define MAX_CHECK 2
  24
  25 static void check_super_value(e2fsck_t ctx, const char *descr,
  26                               unsigned long value, int flags,
  27                               unsigned long min_val, unsigned long max_val)
  28 {
  29         struct          problem_context pctx;
  30
  31         if (((flags & MIN_CHECK) && (value < min_val)) ||
  32             ((flags & MAX_CHECK) && (value > max_val))) {
  33                 clear_problem_context(&pctx);
  34                 pctx.num = value;
  35                 pctx.str = descr;
  36                 fix_problem(ctx, PR_0_MISC_CORRUPT_SUPER, &pctx);
  37                 ctx->flags |= E2F_FLAG_ABORT; /* never get here! */
  38         }
  39 }
  40
  41 /*
  42  * This routine may get stubbed out in special compilations of the
  43  * e2fsck code..
  44  */
  45 #ifndef EXT2_SPECIAL_DEVICE_SIZE
  46 errcode_t e2fsck_get_device_size(e2fsck_t ctx)
  47 {
  48         return (ext2fs_get_device_size(ctx->filesystem_name,
  49                                        EXT2_BLOCK_SIZE(ctx->fs->super),
  50                                        &ctx->num_blocks));
  51 }
  52 #endif
  53
  54 void check_super_block(e2fsck_t ctx)
  55 {
  56         ext2_filsys fs = ctx->fs;
  57         blk_t   first_block, last_block;
  58         struct ext2fs_sb *s = (struct ext2fs_sb *) fs->super;
  59         blk_t   blocks_per_group = fs->super->s_blocks_per_group;
  60         int     inodes_per_block;
  61         dgrp_t  i;
  62         blk_t   should_be;
  63         struct problem_context  pctx;
  64
  65         inodes_per_block = (EXT2_INODE_SIZE(fs->super) +
  66                             EXT2_BLOCK_SIZE(fs->super) - 1) /
  67                                     EXT2_BLOCK_SIZE(fs->super);
  68
  69         ctx->invalid_inode_bitmap_flag = (int *) e2fsck_allocate_memory(ctx,
  70                  sizeof(int) * fs->group_desc_count, "invalid_inode_bitmap");
  71         ctx->invalid_block_bitmap_flag = (int *) e2fsck_allocate_memory(ctx,
  72                  sizeof(int) * fs->group_desc_count, "invalid_block_bitmap");
  73         ctx->invalid_inode_table_flag = (int *) e2fsck_allocate_memory(ctx,
  74                 sizeof(int) * fs->group_desc_count, "invalid_inode_table");
  75
  76         clear_problem_context(&pctx);
  77
  78         /*
  79          * Verify the super block constants...
  80          */
  81         check_super_value(ctx, "inodes_count", s->s_inodes_count,
  82                           MIN_CHECK, 1, 0);
  83         check_super_value(ctx, "blocks_count", s->s_blocks_count,
  84                           MIN_CHECK, 1, 0);
  85         check_super_value(ctx, "first_data_block", s->s_first_data_block,
  86                           MAX_CHECK, 0, s->s_blocks_count);
  87         check_super_value(ctx, "log_frag_size", s->s_log_frag_size,
  88                           MAX_CHECK, 0, 2);
  89         check_super_value(ctx, "log_block_size", s->s_log_block_size,
  90                           MIN_CHECK | MAX_CHECK, s->s_log_frag_size,
  91                           2);
  92         check_super_value(ctx, "frags_per_group", s->s_frags_per_group,
  93                           MIN_CHECK | MAX_CHECK, 1, 8 * EXT2_BLOCK_SIZE(s));
  94         check_super_value(ctx, "blocks_per_group", s->s_blocks_per_group,
  95                           MIN_CHECK | MAX_CHECK, 1, 8 * EXT2_BLOCK_SIZE(s));
  96         check_super_value(ctx, "inodes_per_group", s->s_inodes_per_group,
  97                           MIN_CHECK | MAX_CHECK, 1,
  98                           inodes_per_block * blocks_per_group);
  99         check_super_value(ctx, "r_blocks_count", s->s_r_blocks_count,
 100                           MAX_CHECK, 0, s->s_blocks_count);
 101
 102         if (!ctx->num_blocks) {
 103                 pctx.errcode = e2fsck_get_device_size(ctx);
 104                 if (pctx.errcode && pctx.errcode != EXT2_ET_UNIMPLEMENTED) {
 105                         fix_problem(ctx, PR_0_GETSIZE_ERROR, &pctx);
 106                         ctx->flags |= E2F_FLAG_ABORT;
 107                         return;
 108                 }
 109                 if ((pctx.errcode != EXT2_ET_UNIMPLEMENTED) &&
 110                     (ctx->num_blocks < s->s_blocks_count)) {
 111                         pctx.blk = s->s_blocks_count;
 112                         pctx.blk2 = ctx->num_blocks;
 113                         if (fix_problem(ctx, PR_0_FS_SIZE_WRONG, &pctx)) {
 114                                 ctx->flags |= E2F_FLAG_ABORT;
 115                                 return;
 116                         }
 117                 }
 118         }
 119
 120         if (s->s_log_block_size != s->s_log_frag_size) {
 121                 pctx.blk = EXT2_BLOCK_SIZE(s);
 122                 pctx.blk2 = EXT2_FRAG_SIZE(s);
 123                 fix_problem(ctx, PR_0_NO_FRAGMENTS, &pctx);
 124                 ctx->flags |= E2F_FLAG_ABORT;
 125                 return;
 126         }
 127
 128         should_be = s->s_frags_per_group >>
 129                 (s->s_log_block_size - s->s_log_frag_size);
 130         if (s->s_blocks_per_group != should_be) {
 131                 pctx.blk = s->s_blocks_per_group;
 132                 pctx.blk2 = should_be;
 133                 fix_problem(ctx, PR_0_BLOCKS_PER_GROUP, &pctx);
 134                 ctx->flags |= E2F_FLAG_ABORT;
 135                 return;
 136         }
 137
 138         should_be = (s->s_log_block_size == 0) ? 1 : 0;
 139         if (s->s_first_data_block != should_be) {
 140                 pctx.blk = s->s_first_data_block;
 141                 pctx.blk2 = should_be;
 142                 fix_problem(ctx, PR_0_FIRST_DATA_BLOCK, &pctx);
 143                 ctx->flags |= E2F_FLAG_ABORT;
 144                 return;
 145         }
 146
 147         should_be = s->s_inodes_per_group * fs->group_desc_count;
 148         if (s->s_inodes_count != should_be) {
 149                 pctx.ino = s->s_inodes_count;
 150                 pctx.ino2 = should_be;
 151                 if (fix_problem(ctx, PR_0_INODE_COUNT_WRONG, &pctx)) {
 152                         s->s_inodes_count = should_be;
 153                         ext2fs_mark_super_dirty(fs);
 154                 }
 155         }
 156
 157         /*
 158          * Verify the group descriptors....
 159          */
 160         first_block =  fs->super->s_first_data_block;
 161         last_block = first_block + blocks_per_group;
 162
 163         for (i = 0; i < fs->group_desc_count; i++) {
 164                 pctx.group = i;
 165
 166                 if (i == fs->group_desc_count - 1)
 167                         last_block = fs->super->s_blocks_count;
 168                 if ((fs->group_desc[i].bg_block_bitmap < first_block) ||
 169                     (fs->group_desc[i].bg_block_bitmap >= last_block)) {
 170                         pctx.blk = fs->group_desc[i].bg_block_bitmap;
 171                         if (fix_problem(ctx, PR_0_BB_NOT_GROUP, &pctx)) {
 172                                 fs->group_desc[i].bg_block_bitmap = 0;
 173                                 ctx->invalid_block_bitmap_flag[i]++;
 174                                 ctx->invalid_bitmaps++;
 175                         }
 176                 }
 177                 if ((fs->group_desc[i].bg_inode_bitmap < first_block) ||
 178                     (fs->group_desc[i].bg_inode_bitmap >= last_block)) {
 179                         pctx.blk = fs->group_desc[i].bg_inode_bitmap;
 180                         if (fix_problem(ctx, PR_0_IB_NOT_GROUP, &pctx)) {
 181                                 fs->group_desc[i].bg_inode_bitmap = 0;
 182                                 ctx->invalid_inode_bitmap_flag[i]++;
 183                                 ctx->invalid_bitmaps++;
 184                         }
 185                 }
 186                 if ((fs->group_desc[i].bg_inode_table < first_block) ||
 187                     ((fs->group_desc[i].bg_inode_table +
 188                       fs->inode_blocks_per_group - 1) >= last_block)) {
 189                         pctx.blk = fs->group_desc[i].bg_inode_table;
 190                         if (fix_problem(ctx, PR_0_ITABLE_NOT_GROUP, &pctx)) {
 191                                 fs->group_desc[i].bg_inode_table = 0;
 192                                 ctx->invalid_inode_table_flag[i]++;
 193                                 ctx->invalid_bitmaps++;
 194                         }
 195                 }
 196                 first_block += fs->super->s_blocks_per_group;
 197                 last_block += fs->super->s_blocks_per_group;
 198         }
 199         /*
 200          * If we have invalid bitmaps, set the error state of the
 201          * filesystem.
 202          */
 203         if (ctx->invalid_bitmaps && !(ctx->options & E2F_OPT_READONLY)) {
 204                 fs->super->s_state &= ~EXT2_VALID_FS;
 205                 ext2fs_mark_super_dirty(fs);
 206         }
 207
 208 #ifndef EXT2_SKIP_UUID
 209         /*
 210          * If the UUID field isn't assigned, assign it.
 211          */
 212         if (!(ctx->options & E2F_OPT_READONLY) && uuid_is_null(s->s_uuid)) {
 213                 clear_problem_context(&pctx);
 214                 if (fix_problem(ctx, PR_0_ADD_UUID, &pctx)) {
 215                         uuid_generate(s->s_uuid);
 216                         ext2fs_mark_super_dirty(fs);
 217                 }
 218         }
 219 #endif
 220         return;
 221 }
 222