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         dgrp_t  i;
  61         blk_t   should_be;
  62         struct problem_context  pctx;
  63
  64         ctx->invalid_inode_bitmap_flag = (int *) e2fsck_allocate_memory(ctx,
  65                  sizeof(int) * fs->group_desc_count, "invalid_inode_bitmap");
  66         ctx->invalid_block_bitmap_flag = (int *) e2fsck_allocate_memory(ctx,
  67                  sizeof(int) * fs->group_desc_count, "invalid_block_bitmap");
  68         ctx->invalid_inode_table_flag = (int *) e2fsck_allocate_memory(ctx,
  69                 sizeof(int) * fs->group_desc_count, "invalid_inode_table");
  70
  71         clear_problem_context(&pctx);
  72
  73         /*
  74          * Verify the super block constants...
  75          */
  76         check_super_value(ctx, "inodes_count", s->s_inodes_count,
  77                           MIN_CHECK, 1, 0);
  78         check_super_value(ctx, "blocks_count", s->s_blocks_count,
  79                           MIN_CHECK, 1, 0);
  80         check_super_value(ctx, "first_data_block", s->s_first_data_block,
  81                           MAX_CHECK, 0, s->s_blocks_count);
  82         check_super_value(ctx, "log_frag_size", s->s_log_frag_size,
  83                           MAX_CHECK, 0, 2);
  84         check_super_value(ctx, "log_block_size", s->s_log_block_size,
  85                           MIN_CHECK | MAX_CHECK, s->s_log_frag_size,
  86                           2);
  87         check_super_value(ctx, "frags_per_group", s->s_frags_per_group,
  88                           MIN_CHECK | MAX_CHECK, 1, 8 * EXT2_BLOCK_SIZE(s));
  89         check_super_value(ctx, "blocks_per_group", s->s_blocks_per_group,
  90                           MIN_CHECK | MAX_CHECK, 1, 8 * EXT2_BLOCK_SIZE(s));
  91         check_super_value(ctx, "inodes_per_group", s->s_inodes_per_group,
  92                           MIN_CHECK, 1, 0);
  93         check_super_value(ctx, "r_blocks_count", s->s_r_blocks_count,
  94                           MAX_CHECK, 0, s->s_blocks_count);
  95
  96         if (!ctx->num_blocks) {
  97                 pctx.errcode = e2fsck_get_device_size(ctx);
  98                 if (pctx.errcode && pctx.errcode != EXT2_ET_UNIMPLEMENTED) {
  99                         fix_problem(ctx, PR_0_GETSIZE_ERROR, &pctx);
 100                         ctx->flags |= E2F_FLAG_ABORT;
 101                         return;
 102                 }
 103                 if ((pctx.errcode != EXT2_ET_UNIMPLEMENTED) &&
 104                     (ctx->num_blocks < s->s_blocks_count)) {
 105                         pctx.blk = s->s_blocks_count;
 106                         pctx.blk2 = ctx->num_blocks;
 107                         if (fix_problem(ctx, PR_0_FS_SIZE_WRONG, &pctx)) {
 108                                 ctx->flags |= E2F_FLAG_ABORT;
 109                                 return;
 110                         }
 111                 }
 112         }
 113
 114         if (s->s_log_block_size != s->s_log_frag_size) {
 115                 pctx.blk = EXT2_BLOCK_SIZE(s);
 116                 pctx.blk2 = EXT2_FRAG_SIZE(s);
 117                 fix_problem(ctx, PR_0_NO_FRAGMENTS, &pctx);
 118                 ctx->flags |= E2F_FLAG_ABORT;
 119                 return;
 120         }
 121
 122         should_be = s->s_frags_per_group >>
 123                 (s->s_log_block_size - s->s_log_frag_size);
 124         if (s->s_blocks_per_group != should_be) {
 125                 pctx.blk = s->s_blocks_per_group;
 126                 pctx.blk2 = should_be;
 127                 fix_problem(ctx, PR_0_BLOCKS_PER_GROUP, &pctx);
 128                 ctx->flags |= E2F_FLAG_ABORT;
 129                 return;
 130         }
 131
 132         should_be = (s->s_log_block_size == 0) ? 1 : 0;
 133         if (s->s_first_data_block != should_be) {
 134                 pctx.blk = s->s_first_data_block;
 135                 pctx.blk2 = should_be;
 136                 fix_problem(ctx, PR_0_FIRST_DATA_BLOCK, &pctx);
 137                 ctx->flags |= E2F_FLAG_ABORT;
 138                 return;
 139         }
 140
 141         /*
 142          * Verify the group descriptors....
 143          */
 144         first_block =  fs->super->s_first_data_block;
 145         last_block = first_block + blocks_per_group;
 146
 147         for (i = 0; i < fs->group_desc_count; i++) {
 148                 pctx.group = i;
 149
 150                 if (i == fs->group_desc_count - 1)
 151                         last_block = fs->super->s_blocks_count;
 152                 if ((fs->group_desc[i].bg_block_bitmap < first_block) ||
 153                     (fs->group_desc[i].bg_block_bitmap >= last_block)) {
 154                         pctx.blk = fs->group_desc[i].bg_block_bitmap;
 155                         if (fix_problem(ctx, PR_0_BB_NOT_GROUP, &pctx)) {
 156                                 fs->group_desc[i].bg_block_bitmap = 0;
 157                                 ctx->invalid_block_bitmap_flag[i]++;
 158                                 ctx->invalid_bitmaps++;
 159                         }
 160                 }
 161                 if ((fs->group_desc[i].bg_inode_bitmap < first_block) ||
 162                     (fs->group_desc[i].bg_inode_bitmap >= last_block)) {
 163                         pctx.blk = fs->group_desc[i].bg_inode_bitmap;
 164                         if (fix_problem(ctx, PR_0_IB_NOT_GROUP, &pctx)) {
 165                                 fs->group_desc[i].bg_inode_bitmap = 0;
 166                                 ctx->invalid_inode_bitmap_flag[i]++;
 167                                 ctx->invalid_bitmaps++;
 168                         }
 169                 }
 170                 if ((fs->group_desc[i].bg_inode_table < first_block) ||
 171                     ((fs->group_desc[i].bg_inode_table +
 172                       fs->inode_blocks_per_group - 1) >= last_block)) {
 173                         pctx.blk = fs->group_desc[i].bg_inode_table;
 174                         if (fix_problem(ctx, PR_0_ITABLE_NOT_GROUP, &pctx)) {
 175                                 fs->group_desc[i].bg_inode_table = 0;
 176                                 ctx->invalid_inode_table_flag[i]++;
 177                                 ctx->invalid_bitmaps++;
 178                         }
 179                 }
 180                 first_block += fs->super->s_blocks_per_group;
 181                 last_block += fs->super->s_blocks_per_group;
 182         }
 183         /*
 184          * If we have invalid bitmaps, set the error state of the
 185          * filesystem.
 186          */
 187         if (ctx->invalid_bitmaps && !(ctx->options & E2F_OPT_READONLY)) {
 188                 fs->super->s_state &= ~EXT2_VALID_FS;
 189                 ext2fs_mark_super_dirty(fs);
 190         }
 191
 192 #ifndef EXT2_SKIP_UUID
 193         /*
 194          * If the UUID field isn't assigned, assign it.
 195          */
 196         if (!(ctx->options & E2F_OPT_READONLY) && uuid_is_null(s->s_uuid)) {
 197                 clear_problem_context(&pctx);
 198                 if (fix_problem(ctx, PR_0_ADD_UUID, &pctx)) {
 199                         uuid_generate(s->s_uuid);
 200                         ext2fs_mark_super_dirty(fs);
 201                 }
 202         }
 203 #endif
 204         return;
 205 }
 206