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 /*
  55  * helper function to release an inode
  56  */
  57 struct process_block_struct {
  58         e2fsck_t        ctx;
  59         char            *buf;
  60         struct problem_context *pctx;
  61         int             truncating;
  62         int             truncate_offset;
  63         blk_t           truncate_block;
  64         int             truncated_blocks;
  65         int             abort;
  66         errcode_t       errcode;
  67 };
  68
  69 static int release_inode_block(ext2_filsys fs,
  70                                blk_t    *block_nr,
  71                                int blockcnt,
  72                                void *priv_data)
  73 {
  74         struct process_block_struct *pb;
  75         e2fsck_t                ctx;
  76         struct problem_context  *pctx;
  77         blk_t                   blk = *block_nr;
  78         int                     retval = 0;
  79
  80         pb = (struct process_block_struct *) priv_data;
  81         ctx = pb->ctx;
  82         pctx = pb->pctx;
  83
  84         pctx->blk = blk;
  85         pctx->blkcount = blockcnt;
  86
  87         if (HOLE_BLKADDR(blk))
  88                 return 0;
  89
  90         if ((blk < fs->super->s_first_data_block) ||
  91             (blk >= fs->super->s_blocks_count)) {
  92                 fix_problem(ctx, PR_0_ORPHAN_ILLEGAL_BLOCK_NUM, pctx);
  93         return_abort:
  94                 pb->abort = 1;
  95                 return BLOCK_ABORT;
  96         }
  97
  98         if (!ext2fs_test_block_bitmap(fs->block_map, blk)) {
  99                 fix_problem(ctx, PR_0_ORPHAN_ALREADY_CLEARED_BLOCK, pctx);
 100                 goto return_abort;
 101         }
 102
 103         /*
 104          * If we are deleting an orphan, then we leave the fields alone.
 105          * If we are truncating an orphan, then update the inode fields
 106          * and clean up any partial block data.
 107          */
 108         if (pb->truncating) {
 109                 /*
 110                  * We only remove indirect blocks if they are
 111                  * completely empty.
 112                  */
 113                 if (blockcnt < 0) {
 114                         int     i, limit;
 115                         blk_t   *bp;
 116
 117                         pb->errcode = io_channel_read_blk(fs->io, blk, 1,
 118                                                         pb->buf);
 119                         if (pb->errcode)
 120                                 goto return_abort;
 121
 122                         limit = fs->blocksize >> 2;
 123                         for (i = 0, bp = (blk_t *) pb->buf;
 124                              i < limit;  i++, bp++)
 125                                 if (*bp)
 126                                         return 0;
 127                 }
 128                 /*
 129                  * We don't remove direct blocks until we've reached
 130                  * the truncation block.
 131                  */
 132                 if (blockcnt >= 0 && blockcnt < pb->truncate_block)
 133                         return 0;
 134                 /*
 135                  * If part of the last block needs truncating, we do
 136                  * it here.
 137                  */
 138                 if ((blockcnt == pb->truncate_block) && pb->truncate_offset) {
 139                         pb->errcode = io_channel_read_blk(fs->io, blk, 1,
 140                                                         pb->buf);
 141                         if (pb->errcode)
 142                                 goto return_abort;
 143                         memset(pb->buf + pb->truncate_offset, 0,
 144                                fs->blocksize - pb->truncate_offset);
 145                         pb->errcode = io_channel_write_blk(fs->io, blk, 1,
 146                                                          pb->buf);
 147                         if (pb->errcode)
 148                                 goto return_abort;
 149                 }
 150                 pb->truncated_blocks++;
 151                 *block_nr = 0;
 152                 retval |= BLOCK_CHANGED;
 153         }
 154
 155         ext2fs_unmark_block_bitmap(fs->block_map, blk);
 156         fs->group_desc[ext2fs_group_of_blk(fs, blk)].bg_free_blocks_count++;
 157         fs->super->s_free_blocks_count++;
 158
 159         return retval;
 160 }
 161
 162 /*
 163  * This function releases an inode.  Returns 1 if an inconsistency was
 164  * found.  If the inode has a link count, then it is being truncated and
 165  * not deleted.
 166  */
 167 static int release_inode_blocks(e2fsck_t ctx, ext2_ino_t ino,
 168                                 struct ext2_inode *inode, char* block_buf,
 169                                 struct problem_context *pctx)
 170 {
 171         ext2_filsys                     fs = ctx->fs;
 172         errcode_t                       retval;
 173         struct process_block_struct     pb;
 174
 175         pb.buf = block_buf + 3 * ctx->fs->blocksize;
 176         pb.ctx = ctx;
 177         pb.abort = 0;
 178         pb.errcode = 0;
 179         pb.pctx = pctx;
 180         if (inode->i_links_count) {
 181                 pb.truncating = 1;
 182                 pb.truncate_block = (blk_t)
 183                         ((((long long)inode->i_size_high << 32) +
 184                           inode->i_size + fs->blocksize - 1) /
 185                          fs->blocksize);
 186                 pb.truncate_offset = inode->i_size % fs->blocksize;
 187         } else {
 188                 pb.truncating = 0;
 189                 pb.truncate_block = 0;
 190                 pb.truncate_offset = 0;
 191         }
 192         pb.truncated_blocks = 0;
 193         retval = ext2fs_block_iterate(fs, ino, BLOCK_FLAG_DEPTH_TRAVERSE,
 194                                       block_buf, release_inode_block, &pb);
 195         if (retval) {
 196                 com_err("release_inode_blocks", retval,
 197                         _("while calling ext2fs_block_iterate for inode %d"),
 198                         ino);
 199                 return 1;
 200         }
 201         if (pb.abort)
 202                 return 1;
 203
 204         /* Refresh the inode since ext2fs_block_iterate may have changed it */
 205         e2fsck_read_inode(ctx, ino, inode, "release_inode_blocks");
 206
 207         if (pb.truncated_blocks)
 208                 inode->i_blocks -= pb.truncated_blocks *
 209                         (fs->blocksize / 512);
 210
 211         ext2fs_mark_bb_dirty(fs);
 212         return 0;
 213 }
 214
 215 /*
 216  * This function releases all of the orphan inodes.  It returns 1 if
 217  * it hit some error, and 0 on success.
 218  */
 219 static int release_orphan_inodes(e2fsck_t ctx)
 220 {
 221         ext2_filsys fs = ctx->fs;
 222         int group;
 223         ext2_ino_t      ino, next_ino;
 224         struct ext2_inode inode;
 225         struct problem_context pctx;
 226         char *block_buf;
 227
 228         if ((ino = fs->super->s_last_orphan) == 0)
 229                 return 0;
 230
 231         /*
 232          * Win or lose, we won't be using the head of the orphan inode
 233          * list again.
 234          */
 235         fs->super->s_last_orphan = 0;
 236         ext2fs_mark_super_dirty(fs);
 237
 238         if ((ino < EXT2_FIRST_INODE(fs->super)) ||
 239             (ino > fs->super->s_inodes_count)) {
 240                 clear_problem_context(&pctx);
 241                 pctx.ino = ino;
 242                 fix_problem(ctx, PR_0_ORPHAN_ILLEGAL_HEAD_INODE, &pctx);
 243                 return 1;
 244         }
 245
 246         block_buf = (char *) e2fsck_allocate_memory(ctx, fs->blocksize * 4,
 247                                                     "block iterate buffer");
 248         e2fsck_read_bitmaps(ctx);
 249
 250         while (ino) {
 251                 e2fsck_read_inode(ctx, ino, &inode, "release_orphan_inodes");
 252                 clear_problem_context(&pctx);
 253                 pctx.ino = ino;
 254                 pctx.inode = &inode;
 255                 pctx.str = inode.i_links_count ? "Truncating" : "Clearing";
 256
 257                 fix_problem(ctx, PR_0_ORPHAN_CLEAR_INODE, &pctx);
 258
 259                 next_ino = inode.i_dtime;
 260                 if (next_ino &&
 261                     ((next_ino < EXT2_FIRST_INODE(fs->super)) ||
 262                      (next_ino > fs->super->s_inodes_count))) {
 263                         pctx.ino = next_ino;
 264                         fix_problem(ctx, PR_0_ORPHAN_ILLEGAL_INODE, &pctx);
 265                         goto return_abort;
 266                 }
 267
 268                 if (release_inode_blocks(ctx, ino, &inode, block_buf, &pctx))
 269                         goto return_abort;
 270
 271                 if (!inode.i_links_count) {
 272                         ext2fs_unmark_inode_bitmap(fs->inode_map, ino);
 273                         ext2fs_mark_ib_dirty(fs);
 274                         group = ext2fs_group_of_ino(fs, ino);
 275                         fs->group_desc[group].bg_free_inodes_count++;
 276                         fs->super->s_free_inodes_count++;
 277                         if (LINUX_S_ISDIR(inode.i_mode))
 278                                 fs->group_desc[group].bg_used_dirs_count--;
 279
 280                         inode.i_dtime = time(0);
 281                 }
 282                 e2fsck_write_inode(ctx, ino, &inode, "delete_file");
 283                 ino = next_ino;
 284         }
 285         return 0;
 286 return_abort:
 287         ext2fs_free_mem((void **) &block_buf);
 288         return 1;
 289 }
 290
 291
 292 void check_super_block(e2fsck_t ctx)
 293 {
 294         ext2_filsys fs = ctx->fs;
 295         blk_t   first_block, last_block;
 296         struct ext2_super_block *sb = fs->super;
 297         blk_t   blocks_per_group = fs->super->s_blocks_per_group;
 298         int     inodes_per_block;
 299         dgrp_t  i;
 300         blk_t   should_be;
 301         struct problem_context  pctx;
 302
 303         inodes_per_block = (EXT2_INODE_SIZE(fs->super) +
 304                             EXT2_BLOCK_SIZE(fs->super) - 1) /
 305                                     EXT2_BLOCK_SIZE(fs->super);
 306
 307         ctx->invalid_inode_bitmap_flag = (int *) e2fsck_allocate_memory(ctx,
 308                  sizeof(int) * fs->group_desc_count, "invalid_inode_bitmap");
 309         ctx->invalid_block_bitmap_flag = (int *) e2fsck_allocate_memory(ctx,
 310                  sizeof(int) * fs->group_desc_count, "invalid_block_bitmap");
 311         ctx->invalid_inode_table_flag = (int *) e2fsck_allocate_memory(ctx,
 312                 sizeof(int) * fs->group_desc_count, "invalid_inode_table");
 313
 314         clear_problem_context(&pctx);
 315
 316         /*
 317          * Verify the super block constants...
 318          */
 319         check_super_value(ctx, "inodes_count", sb->s_inodes_count,
 320                           MIN_CHECK, 1, 0);
 321         check_super_value(ctx, "blocks_count", sb->s_blocks_count,
 322                           MIN_CHECK, 1, 0);
 323         check_super_value(ctx, "first_data_block", sb->s_first_data_block,
 324                           MAX_CHECK, 0, sb->s_blocks_count);
 325         check_super_value(ctx, "log_frag_size", sb->s_log_frag_size,
 326                           MAX_CHECK, 0, 2);
 327         check_super_value(ctx, "log_block_size", sb->s_log_block_size,
 328                           MIN_CHECK | MAX_CHECK, sb->s_log_frag_size,
 329                           2);
 330         check_super_value(ctx, "frags_per_group", sb->s_frags_per_group,
 331                           MIN_CHECK | MAX_CHECK, 1, 8 * EXT2_BLOCK_SIZE(sb));
 332         check_super_value(ctx, "blocks_per_group", sb->s_blocks_per_group,
 333                           MIN_CHECK | MAX_CHECK, 1, 8 * EXT2_BLOCK_SIZE(sb));
 334         check_super_value(ctx, "inodes_per_group", sb->s_inodes_per_group,
 335                           MIN_CHECK | MAX_CHECK, 1,
 336                           inodes_per_block * blocks_per_group);
 337         check_super_value(ctx, "r_blocks_count", sb->s_r_blocks_count,
 338                           MAX_CHECK, 0, sb->s_blocks_count);
 339
 340         if (!ctx->num_blocks) {
 341                 pctx.errcode = e2fsck_get_device_size(ctx);
 342                 if (pctx.errcode && pctx.errcode != EXT2_ET_UNIMPLEMENTED) {
 343                         fix_problem(ctx, PR_0_GETSIZE_ERROR, &pctx);
 344                         ctx->flags |= E2F_FLAG_ABORT;
 345                         return;
 346                 }
 347                 if ((pctx.errcode != EXT2_ET_UNIMPLEMENTED) &&
 348                     (ctx->num_blocks < sb->s_blocks_count)) {
 349                         pctx.blk = sb->s_blocks_count;
 350                         pctx.blk2 = ctx->num_blocks;
 351                         if (fix_problem(ctx, PR_0_FS_SIZE_WRONG, &pctx)) {
 352                                 ctx->flags |= E2F_FLAG_ABORT;
 353                                 return;
 354                         }
 355                 }
 356         }
 357
 358         if (sb->s_log_block_size != sb->s_log_frag_size) {
 359                 pctx.blk = EXT2_BLOCK_SIZE(sb);
 360                 pctx.blk2 = EXT2_FRAG_SIZE(sb);
 361                 fix_problem(ctx, PR_0_NO_FRAGMENTS, &pctx);
 362                 ctx->flags |= E2F_FLAG_ABORT;
 363                 return;
 364         }
 365
 366         should_be = sb->s_frags_per_group >>
 367                 (sb->s_log_block_size - sb->s_log_frag_size);
 368         if (sb->s_blocks_per_group != should_be) {
 369                 pctx.blk = sb->s_blocks_per_group;
 370                 pctx.blk2 = should_be;
 371                 fix_problem(ctx, PR_0_BLOCKS_PER_GROUP, &pctx);
 372                 ctx->flags |= E2F_FLAG_ABORT;
 373                 return;
 374         }
 375
 376         should_be = (sb->s_log_block_size == 0) ? 1 : 0;
 377         if (sb->s_first_data_block != should_be) {
 378                 pctx.blk = sb->s_first_data_block;
 379                 pctx.blk2 = should_be;
 380                 fix_problem(ctx, PR_0_FIRST_DATA_BLOCK, &pctx);
 381                 ctx->flags |= E2F_FLAG_ABORT;
 382                 return;
 383         }
 384
 385         should_be = sb->s_inodes_per_group * fs->group_desc_count;
 386         if (sb->s_inodes_count != should_be) {
 387                 pctx.ino = sb->s_inodes_count;
 388                 pctx.ino2 = should_be;
 389                 if (fix_problem(ctx, PR_0_INODE_COUNT_WRONG, &pctx)) {
 390                         sb->s_inodes_count = should_be;
 391                         ext2fs_mark_super_dirty(fs);
 392                 }
 393         }
 394
 395         /*
 396          * Verify the group descriptors....
 397          */
 398         first_block =  fs->super->s_first_data_block;
 399         last_block = first_block + blocks_per_group;
 400
 401         for (i = 0; i < fs->group_desc_count; i++) {
 402                 pctx.group = i;
 403
 404                 if (i == fs->group_desc_count - 1)
 405                         last_block = fs->super->s_blocks_count;
 406                 if ((fs->group_desc[i].bg_block_bitmap < first_block) ||
 407                     (fs->group_desc[i].bg_block_bitmap >= last_block)) {
 408                         pctx.blk = fs->group_desc[i].bg_block_bitmap;
 409                         if (fix_problem(ctx, PR_0_BB_NOT_GROUP, &pctx)) {
 410                                 fs->group_desc[i].bg_block_bitmap = 0;
 411                                 ctx->invalid_block_bitmap_flag[i]++;
 412                                 ctx->invalid_bitmaps++;
 413                         }
 414                 }
 415                 if ((fs->group_desc[i].bg_inode_bitmap < first_block) ||
 416                     (fs->group_desc[i].bg_inode_bitmap >= last_block)) {
 417                         pctx.blk = fs->group_desc[i].bg_inode_bitmap;
 418                         if (fix_problem(ctx, PR_0_IB_NOT_GROUP, &pctx)) {
 419                                 fs->group_desc[i].bg_inode_bitmap = 0;
 420                                 ctx->invalid_inode_bitmap_flag[i]++;
 421                                 ctx->invalid_bitmaps++;
 422                         }
 423                 }
 424                 if ((fs->group_desc[i].bg_inode_table < first_block) ||
 425                     ((fs->group_desc[i].bg_inode_table +
 426                       fs->inode_blocks_per_group - 1) >= last_block)) {
 427                         pctx.blk = fs->group_desc[i].bg_inode_table;
 428                         if (fix_problem(ctx, PR_0_ITABLE_NOT_GROUP, &pctx)) {
 429                                 fs->group_desc[i].bg_inode_table = 0;
 430                                 ctx->invalid_inode_table_flag[i]++;
 431                                 ctx->invalid_bitmaps++;
 432                         }
 433                 }
 434                 first_block += fs->super->s_blocks_per_group;
 435                 last_block += fs->super->s_blocks_per_group;
 436         }
 437         /*
 438          * If we have invalid bitmaps, set the error state of the
 439          * filesystem.
 440          */
 441         if (ctx->invalid_bitmaps && !(ctx->options & E2F_OPT_READONLY)) {
 442                 fs->super->s_state &= ~EXT2_VALID_FS;
 443                 ext2fs_mark_super_dirty(fs);
 444         }
 445
 446         clear_problem_context(&pctx);
 447
 448 #ifndef EXT2_SKIP_UUID
 449         /*
 450          * If the UUID field isn't assigned, assign it.
 451          */
 452         if (!(ctx->options & E2F_OPT_READONLY) && uuid_is_null(sb->s_uuid)) {
 453                 if (fix_problem(ctx, PR_0_ADD_UUID, &pctx)) {
 454                         uuid_generate(sb->s_uuid);
 455                         ext2fs_mark_super_dirty(fs);
 456                 }
 457         }
 458 #endif
 459
 460         /*
 461          * For the Hurd, check to see if the filetype option is set,
 462          * since it doesn't support it.
 463          */
 464         if (!(ctx->options & E2F_OPT_READONLY) &&
 465             fs->super->s_creator_os == EXT2_OS_HURD &&
 466             (fs->super->s_feature_incompat &
 467              EXT2_FEATURE_INCOMPAT_FILETYPE)) {
 468                 if (fix_problem(ctx, PR_0_HURD_CLEAR_FILETYPE, &pctx)) {
 469                         fs->super->s_feature_incompat &=
 470                                 ~EXT2_FEATURE_INCOMPAT_FILETYPE;
 471                         ext2fs_mark_super_dirty(fs);
 472
 473                 }
 474         }
 475
 476         /*
 477          * If we have any of the compatibility flags set, we need to have a
 478          * revision 1 filesystem.  Most kernels will not check the flags on
 479          * a rev 0 filesystem and we may have corruption issues because of
 480          * the incompatible changes to the filesystem.
 481          */
 482         if (!(ctx->options & E2F_OPT_READONLY) &&
 483             fs->super->s_rev_level == EXT2_GOOD_OLD_REV &&
 484             (fs->super->s_feature_compat ||
 485              fs->super->s_feature_ro_compat ||
 486              fs->super->s_feature_incompat) &&
 487             fix_problem(ctx, PR_0_FS_REV_LEVEL, &pctx)) {
 488                 ext2fs_update_dynamic_rev(fs);
 489                 ext2fs_mark_super_dirty(fs);
 490         }
 491
 492         /*
 493          * Clean up any orphan inodes, if present.
 494          */
 495         if (!(ctx->options & E2F_OPT_READONLY) && release_orphan_inodes(ctx)) {
 496                 fs->super->s_state &= ~EXT2_VALID_FS;
 497                 ext2fs_mark_super_dirty(fs);
 498         }
 499
 500         return;
 501 }
 502
 503