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         if (!ext2fs_inode_has_valid_blocks(inode))
 176                 return 0;
 177
 178         pb.buf = block_buf + 3 * ctx->fs->blocksize;
 179         pb.ctx = ctx;
 180         pb.abort = 0;
 181         pb.errcode = 0;
 182         pb.pctx = pctx;
 183         if (inode->i_links_count) {
 184                 pb.truncating = 1;
 185                 pb.truncate_block = (blk_t)
 186                         ((((long long)inode->i_size_high << 32) +
 187                           inode->i_size + fs->blocksize - 1) /
 188                          fs->blocksize);
 189                 pb.truncate_offset = inode->i_size % fs->blocksize;
 190         } else {
 191                 pb.truncating = 0;
 192                 pb.truncate_block = 0;
 193                 pb.truncate_offset = 0;
 194         }
 195         pb.truncated_blocks = 0;
 196         retval = ext2fs_block_iterate(fs, ino, BLOCK_FLAG_DEPTH_TRAVERSE,
 197                                       block_buf, release_inode_block, &pb);
 198         if (retval) {
 199                 com_err("release_inode_blocks", retval,
 200                         _("while calling ext2fs_block_iterate for inode %d"),
 201                         ino);
 202                 return 1;
 203         }
 204         if (pb.abort)
 205                 return 1;
 206
 207         /* Refresh the inode since ext2fs_block_iterate may have changed it */
 208         e2fsck_read_inode(ctx, ino, inode, "release_inode_blocks");
 209
 210         if (pb.truncated_blocks)
 211                 inode->i_blocks -= pb.truncated_blocks *
 212                         (fs->blocksize / 512);
 213
 214         ext2fs_mark_bb_dirty(fs);
 215         return 0;
 216 }
 217
 218 /*
 219  * This function releases all of the orphan inodes.  It returns 1 if
 220  * it hit some error, and 0 on success.
 221  */
 222 static int release_orphan_inodes(e2fsck_t ctx)
 223 {
 224         ext2_filsys fs = ctx->fs;
 225         int group;
 226         ext2_ino_t      ino, next_ino;
 227         struct ext2_inode inode;
 228         struct problem_context pctx;
 229         char *block_buf;
 230
 231         if ((ino = fs->super->s_last_orphan) == 0)
 232                 return 0;
 233
 234         /*
 235          * Win or lose, we won't be using the head of the orphan inode
 236          * list again.
 237          */
 238         fs->super->s_last_orphan = 0;
 239         ext2fs_mark_super_dirty(fs);
 240
 241         /*
 242          * If the filesystem contains errors, don't run the orphan
 243          * list, since the orphan list can't be trusted; and we're
 244          * going to be running a full e2fsck run anyway...
 245          */
 246         if (fs->super->s_state & EXT2_ERROR_FS)
 247                 return 0;
 248
 249         if ((ino < EXT2_FIRST_INODE(fs->super)) ||
 250             (ino > fs->super->s_inodes_count)) {
 251                 clear_problem_context(&pctx);
 252                 pctx.ino = ino;
 253                 fix_problem(ctx, PR_0_ORPHAN_ILLEGAL_HEAD_INODE, &pctx);
 254                 return 1;
 255         }
 256
 257         block_buf = (char *) e2fsck_allocate_memory(ctx, fs->blocksize * 4,
 258                                                     "block iterate buffer");
 259         e2fsck_read_bitmaps(ctx);
 260
 261         while (ino) {
 262                 e2fsck_read_inode(ctx, ino, &inode, "release_orphan_inodes");
 263                 clear_problem_context(&pctx);
 264                 pctx.ino = ino;
 265                 pctx.inode = &inode;
 266                 pctx.str = inode.i_links_count ? _("Truncating") :
 267                         _("Clearing");
 268
 269                 fix_problem(ctx, PR_0_ORPHAN_CLEAR_INODE, &pctx);
 270
 271                 next_ino = inode.i_dtime;
 272                 if (next_ino &&
 273                     ((next_ino < EXT2_FIRST_INODE(fs->super)) ||
 274                      (next_ino > fs->super->s_inodes_count))) {
 275                         pctx.ino = next_ino;
 276                         fix_problem(ctx, PR_0_ORPHAN_ILLEGAL_INODE, &pctx);
 277                         goto return_abort;
 278                 }
 279
 280                 if (release_inode_blocks(ctx, ino, &inode, block_buf, &pctx))
 281                         goto return_abort;
 282
 283                 if (!inode.i_links_count) {
 284                         ext2fs_unmark_inode_bitmap(fs->inode_map, ino);
 285                         ext2fs_mark_ib_dirty(fs);
 286                         group = ext2fs_group_of_ino(fs, ino);
 287                         fs->group_desc[group].bg_free_inodes_count++;
 288                         fs->super->s_free_inodes_count++;
 289                         if (LINUX_S_ISDIR(inode.i_mode))
 290                                 fs->group_desc[group].bg_used_dirs_count--;
 291
 292                         inode.i_dtime = time(0);
 293                 }
 294                 e2fsck_write_inode(ctx, ino, &inode, "delete_file");
 295                 ino = next_ino;
 296         }
 297         ext2fs_free_mem((void **) &block_buf);
 298         return 0;
 299 return_abort:
 300         ext2fs_free_mem((void **) &block_buf);
 301         return 1;
 302 }
 303
 304
 305 void check_super_block(e2fsck_t ctx)
 306 {
 307         ext2_filsys fs = ctx->fs;
 308         blk_t   first_block, last_block;
 309         struct ext2_super_block *sb = fs->super;
 310         blk_t   blocks_per_group = fs->super->s_blocks_per_group;
 311         blk_t   bpg_max;
 312         int     inodes_per_block;
 313         int     ipg_max;
 314         dgrp_t  i;
 315         blk_t   should_be;
 316         struct problem_context  pctx;
 317
 318         inodes_per_block = EXT2_INODES_PER_BLOCK(fs->super);
 319         ipg_max = inodes_per_block * (blocks_per_group - 4);
 320         if (ipg_max > EXT2_MAX_INODES_PER_GROUP(sb))
 321                 ipg_max = EXT2_MAX_INODES_PER_GROUP(sb);
 322         bpg_max = 8 * EXT2_BLOCK_SIZE(sb);
 323         if (bpg_max > EXT2_MAX_BLOCKS_PER_GROUP(sb))
 324                 bpg_max = EXT2_MAX_BLOCKS_PER_GROUP(sb);
 325
 326         ctx->invalid_inode_bitmap_flag = (int *) e2fsck_allocate_memory(ctx,
 327                  sizeof(int) * fs->group_desc_count, "invalid_inode_bitmap");
 328         ctx->invalid_block_bitmap_flag = (int *) e2fsck_allocate_memory(ctx,
 329                  sizeof(int) * fs->group_desc_count, "invalid_block_bitmap");
 330         ctx->invalid_inode_table_flag = (int *) e2fsck_allocate_memory(ctx,
 331                 sizeof(int) * fs->group_desc_count, "invalid_inode_table");
 332
 333         clear_problem_context(&pctx);
 334
 335         /*
 336          * Verify the super block constants...
 337          */
 338         check_super_value(ctx, "inodes_count", sb->s_inodes_count,
 339                           MIN_CHECK, 1, 0);
 340         check_super_value(ctx, "blocks_count", sb->s_blocks_count,
 341                           MIN_CHECK, 1, 0);
 342         check_super_value(ctx, "first_data_block", sb->s_first_data_block,
 343                           MAX_CHECK, 0, sb->s_blocks_count);
 344         check_super_value(ctx, "log_block_size", sb->s_log_block_size,
 345                           MIN_CHECK | MAX_CHECK, 0,
 346                           EXT2_MAX_BLOCK_LOG_SIZE - EXT2_MIN_BLOCK_LOG_SIZE);
 347         check_super_value(ctx, "log_frag_size", sb->s_log_frag_size,
 348                           MIN_CHECK | MAX_CHECK, 0, sb->s_log_block_size);
 349         check_super_value(ctx, "frags_per_group", sb->s_frags_per_group,
 350                           MIN_CHECK | MAX_CHECK, sb->s_blocks_per_group,
 351                           bpg_max);
 352         check_super_value(ctx, "blocks_per_group", sb->s_blocks_per_group,
 353                           MIN_CHECK | MAX_CHECK, 8, bpg_max);
 354         check_super_value(ctx, "inodes_per_group", sb->s_inodes_per_group,
 355                           MIN_CHECK | MAX_CHECK, inodes_per_block, ipg_max);
 356         check_super_value(ctx, "r_blocks_count", sb->s_r_blocks_count,
 357                           MAX_CHECK, 0, sb->s_blocks_count / 4);
 358
 359         if (!ctx->num_blocks) {
 360                 pctx.errcode = e2fsck_get_device_size(ctx);
 361                 if (pctx.errcode && pctx.errcode != EXT2_ET_UNIMPLEMENTED) {
 362                         fix_problem(ctx, PR_0_GETSIZE_ERROR, &pctx);
 363                         ctx->flags |= E2F_FLAG_ABORT;
 364                         return;
 365                 }
 366                 if ((pctx.errcode != EXT2_ET_UNIMPLEMENTED) &&
 367                     (ctx->num_blocks < sb->s_blocks_count)) {
 368                         pctx.blk = sb->s_blocks_count;
 369                         pctx.blk2 = ctx->num_blocks;
 370                         if (fix_problem(ctx, PR_0_FS_SIZE_WRONG, &pctx)) {
 371                                 ctx->flags |= E2F_FLAG_ABORT;
 372                                 return;
 373                         }
 374                 }
 375         }
 376
 377         if (sb->s_log_block_size != sb->s_log_frag_size) {
 378                 pctx.blk = EXT2_BLOCK_SIZE(sb);
 379                 pctx.blk2 = EXT2_FRAG_SIZE(sb);
 380                 fix_problem(ctx, PR_0_NO_FRAGMENTS, &pctx);
 381                 ctx->flags |= E2F_FLAG_ABORT;
 382                 return;
 383         }
 384
 385         should_be = sb->s_frags_per_group >>
 386                 (sb->s_log_block_size - sb->s_log_frag_size);
 387         if (sb->s_blocks_per_group != should_be) {
 388                 pctx.blk = sb->s_blocks_per_group;
 389                 pctx.blk2 = should_be;
 390                 fix_problem(ctx, PR_0_BLOCKS_PER_GROUP, &pctx);
 391                 ctx->flags |= E2F_FLAG_ABORT;
 392                 return;
 393         }
 394
 395         should_be = (sb->s_log_block_size == 0) ? 1 : 0;
 396         if (sb->s_first_data_block != should_be) {
 397                 pctx.blk = sb->s_first_data_block;
 398                 pctx.blk2 = should_be;
 399                 fix_problem(ctx, PR_0_FIRST_DATA_BLOCK, &pctx);
 400                 ctx->flags |= E2F_FLAG_ABORT;
 401                 return;
 402         }
 403
 404         should_be = sb->s_inodes_per_group * fs->group_desc_count;
 405         if (sb->s_inodes_count != should_be) {
 406                 pctx.ino = sb->s_inodes_count;
 407                 pctx.ino2 = should_be;
 408                 if (fix_problem(ctx, PR_0_INODE_COUNT_WRONG, &pctx)) {
 409                         sb->s_inodes_count = should_be;
 410                         ext2fs_mark_super_dirty(fs);
 411                 }
 412         }
 413
 414         /*
 415          * Verify the group descriptors....
 416          */
 417         first_block =  fs->super->s_first_data_block;
 418         last_block = first_block + blocks_per_group;
 419
 420         for (i = 0; i < fs->group_desc_count; i++) {
 421                 pctx.group = i;
 422
 423                 if (i == fs->group_desc_count - 1)
 424                         last_block = fs->super->s_blocks_count;
 425                 if ((fs->group_desc[i].bg_block_bitmap < first_block) ||
 426                     (fs->group_desc[i].bg_block_bitmap >= last_block)) {
 427                         pctx.blk = fs->group_desc[i].bg_block_bitmap;
 428                         if (fix_problem(ctx, PR_0_BB_NOT_GROUP, &pctx))
 429                                 fs->group_desc[i].bg_block_bitmap = 0;
 430                 }
 431                 if (fs->group_desc[i].bg_block_bitmap == 0) {
 432                         ctx->invalid_block_bitmap_flag[i]++;
 433                         ctx->invalid_bitmaps++;
 434                 }
 435                 if ((fs->group_desc[i].bg_inode_bitmap < first_block) ||
 436                     (fs->group_desc[i].bg_inode_bitmap >= last_block)) {
 437                         pctx.blk = fs->group_desc[i].bg_inode_bitmap;
 438                         if (fix_problem(ctx, PR_0_IB_NOT_GROUP, &pctx))
 439                                 fs->group_desc[i].bg_inode_bitmap = 0;
 440                 }
 441                 if (fs->group_desc[i].bg_inode_bitmap == 0) {
 442                         ctx->invalid_inode_bitmap_flag[i]++;
 443                         ctx->invalid_bitmaps++;
 444                 }
 445                 if ((fs->group_desc[i].bg_inode_table < first_block) ||
 446                     ((fs->group_desc[i].bg_inode_table +
 447                       fs->inode_blocks_per_group - 1) >= last_block)) {
 448                         pctx.blk = fs->group_desc[i].bg_inode_table;
 449                         if (fix_problem(ctx, PR_0_ITABLE_NOT_GROUP, &pctx))
 450                                 fs->group_desc[i].bg_inode_table = 0;
 451                 }
 452                 if (fs->group_desc[i].bg_inode_table == 0) {
 453                         ctx->invalid_inode_table_flag[i]++;
 454                         ctx->invalid_bitmaps++;
 455                 }
 456                 first_block += fs->super->s_blocks_per_group;
 457                 last_block += fs->super->s_blocks_per_group;
 458         }
 459         /*
 460          * If we have invalid bitmaps, set the error state of the
 461          * filesystem.
 462          */
 463         if (ctx->invalid_bitmaps && !(ctx->options & E2F_OPT_READONLY)) {
 464                 fs->super->s_state &= ~EXT2_VALID_FS;
 465                 ext2fs_mark_super_dirty(fs);
 466         }
 467
 468         clear_problem_context(&pctx);
 469
 470 #ifndef EXT2_SKIP_UUID
 471         /*
 472          * If the UUID field isn't assigned, assign it.
 473          */
 474         if (!(ctx->options & E2F_OPT_READONLY) && uuid_is_null(sb->s_uuid)) {
 475                 if (fix_problem(ctx, PR_0_ADD_UUID, &pctx)) {
 476                         uuid_generate(sb->s_uuid);
 477                         ext2fs_mark_super_dirty(fs);
 478                 }
 479         }
 480 #endif
 481
 482         /*
 483          * For the Hurd, check to see if the filetype option is set,
 484          * since it doesn't support it.
 485          */
 486         if (!(ctx->options & E2F_OPT_READONLY) &&
 487             fs->super->s_creator_os == EXT2_OS_HURD &&
 488             (fs->super->s_feature_incompat &
 489              EXT2_FEATURE_INCOMPAT_FILETYPE)) {
 490                 if (fix_problem(ctx, PR_0_HURD_CLEAR_FILETYPE, &pctx)) {
 491                         fs->super->s_feature_incompat &=
 492                                 ~EXT2_FEATURE_INCOMPAT_FILETYPE;
 493                         ext2fs_mark_super_dirty(fs);
 494
 495                 }
 496         }
 497
 498         /*
 499          * If we have any of the compatibility flags set, we need to have a
 500          * revision 1 filesystem.  Most kernels will not check the flags on
 501          * a rev 0 filesystem and we may have corruption issues because of
 502          * the incompatible changes to the filesystem.
 503          */
 504         if (!(ctx->options & E2F_OPT_READONLY) &&
 505             fs->super->s_rev_level == EXT2_GOOD_OLD_REV &&
 506             (fs->super->s_feature_compat ||
 507              fs->super->s_feature_ro_compat ||
 508              fs->super->s_feature_incompat) &&
 509             fix_problem(ctx, PR_0_FS_REV_LEVEL, &pctx)) {
 510                 ext2fs_update_dynamic_rev(fs);
 511                 ext2fs_mark_super_dirty(fs);
 512         }
 513
 514         /*
 515          * Clean up any orphan inodes, if present.
 516          */
 517         if (!(ctx->options & E2F_OPT_READONLY) && release_orphan_inodes(ctx)) {
 518                 fs->super->s_state &= ~EXT2_VALID_FS;
 519                 ext2fs_mark_super_dirty(fs);
 520         }
 521
 522         /*
 523          * Move the ext3 journal file, if necessary.
 524          */
 525         e2fsck_move_ext3_journal(ctx);
 526         return;
 527 }
 528
 529