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         if ((ino < EXT2_FIRST_INODE(fs->super)) ||
 242             (ino > fs->super->s_inodes_count)) {
 243                 clear_problem_context(&pctx);
 244                 pctx.ino = ino;
 245                 fix_problem(ctx, PR_0_ORPHAN_ILLEGAL_HEAD_INODE, &pctx);
 246                 return 1;
 247         }
 248
 249         block_buf = (char *) e2fsck_allocate_memory(ctx, fs->blocksize * 4,
 250                                                     "block iterate buffer");
 251         e2fsck_read_bitmaps(ctx);
 252
 253         while (ino) {
 254                 e2fsck_read_inode(ctx, ino, &inode, "release_orphan_inodes");
 255                 clear_problem_context(&pctx);
 256                 pctx.ino = ino;
 257                 pctx.inode = &inode;
 258                 pctx.str = inode.i_links_count ? _("Truncating") :
 259                         _("Clearing");
 260
 261                 fix_problem(ctx, PR_0_ORPHAN_CLEAR_INODE, &pctx);
 262
 263                 next_ino = inode.i_dtime;
 264                 if (next_ino &&
 265                     ((next_ino < EXT2_FIRST_INODE(fs->super)) ||
 266                      (next_ino > fs->super->s_inodes_count))) {
 267                         pctx.ino = next_ino;
 268                         fix_problem(ctx, PR_0_ORPHAN_ILLEGAL_INODE, &pctx);
 269                         goto return_abort;
 270                 }
 271
 272                 if (release_inode_blocks(ctx, ino, &inode, block_buf, &pctx))
 273                         goto return_abort;
 274
 275                 if (!inode.i_links_count) {
 276                         ext2fs_unmark_inode_bitmap(fs->inode_map, ino);
 277                         ext2fs_mark_ib_dirty(fs);
 278                         group = ext2fs_group_of_ino(fs, ino);
 279                         fs->group_desc[group].bg_free_inodes_count++;
 280                         fs->super->s_free_inodes_count++;
 281                         if (LINUX_S_ISDIR(inode.i_mode))
 282                                 fs->group_desc[group].bg_used_dirs_count--;
 283
 284                         inode.i_dtime = time(0);
 285                 }
 286                 e2fsck_write_inode(ctx, ino, &inode, "delete_file");
 287                 ino = next_ino;
 288         }
 289         return 0;
 290 return_abort:
 291         ext2fs_free_mem((void **) &block_buf);
 292         return 1;
 293 }
 294
 295
 296 void check_super_block(e2fsck_t ctx)
 297 {
 298         ext2_filsys fs = ctx->fs;
 299         blk_t   first_block, last_block;
 300         struct ext2_super_block *sb = fs->super;
 301         blk_t   blocks_per_group = fs->super->s_blocks_per_group;
 302         int     inodes_per_block;
 303         dgrp_t  i;
 304         blk_t   should_be;
 305         struct problem_context  pctx;
 306
 307         inodes_per_block = (EXT2_BLOCK_SIZE(fs->super) /
 308                             EXT2_INODE_SIZE(fs->super));
 309
 310         ctx->invalid_inode_bitmap_flag = (int *) e2fsck_allocate_memory(ctx,
 311                  sizeof(int) * fs->group_desc_count, "invalid_inode_bitmap");
 312         ctx->invalid_block_bitmap_flag = (int *) e2fsck_allocate_memory(ctx,
 313                  sizeof(int) * fs->group_desc_count, "invalid_block_bitmap");
 314         ctx->invalid_inode_table_flag = (int *) e2fsck_allocate_memory(ctx,
 315                 sizeof(int) * fs->group_desc_count, "invalid_inode_table");
 316
 317         clear_problem_context(&pctx);
 318
 319         /*
 320          * Verify the super block constants...
 321          */
 322         check_super_value(ctx, "inodes_count", sb->s_inodes_count,
 323                           MIN_CHECK, 1, 0);
 324         check_super_value(ctx, "blocks_count", sb->s_blocks_count,
 325                           MIN_CHECK, 1, 0);
 326         check_super_value(ctx, "first_data_block", sb->s_first_data_block,
 327                           MAX_CHECK, 0, sb->s_blocks_count);
 328         check_super_value(ctx, "log_frag_size", sb->s_log_frag_size,
 329                           MAX_CHECK, 0, 2);
 330         check_super_value(ctx, "log_block_size", sb->s_log_block_size,
 331                           MIN_CHECK | MAX_CHECK, sb->s_log_frag_size,
 332                           2);
 333         check_super_value(ctx, "frags_per_group", sb->s_frags_per_group,
 334                           MIN_CHECK | MAX_CHECK, sb->s_blocks_per_group,
 335                           8 * EXT2_BLOCK_SIZE(sb));
 336         check_super_value(ctx, "blocks_per_group", sb->s_blocks_per_group,
 337                           MIN_CHECK | MAX_CHECK, 8, 8 * EXT2_BLOCK_SIZE(sb));
 338         check_super_value(ctx, "inodes_per_group", sb->s_inodes_per_group,
 339                           MIN_CHECK | MAX_CHECK, inodes_per_block,
 340                           inodes_per_block * (blocks_per_group-4));
 341         check_super_value(ctx, "r_blocks_count", sb->s_r_blocks_count,
 342                           MAX_CHECK, 0, sb->s_blocks_count / 4);
 343
 344         if (!ctx->num_blocks) {
 345                 pctx.errcode = e2fsck_get_device_size(ctx);
 346                 if (pctx.errcode && pctx.errcode != EXT2_ET_UNIMPLEMENTED) {
 347                         fix_problem(ctx, PR_0_GETSIZE_ERROR, &pctx);
 348                         ctx->flags |= E2F_FLAG_ABORT;
 349                         return;
 350                 }
 351                 if ((pctx.errcode != EXT2_ET_UNIMPLEMENTED) &&
 352                     (ctx->num_blocks < sb->s_blocks_count)) {
 353                         pctx.blk = sb->s_blocks_count;
 354                         pctx.blk2 = ctx->num_blocks;
 355                         if (fix_problem(ctx, PR_0_FS_SIZE_WRONG, &pctx)) {
 356                                 ctx->flags |= E2F_FLAG_ABORT;
 357                                 return;
 358                         }
 359                 }
 360         }
 361
 362         if (sb->s_log_block_size != sb->s_log_frag_size) {
 363                 pctx.blk = EXT2_BLOCK_SIZE(sb);
 364                 pctx.blk2 = EXT2_FRAG_SIZE(sb);
 365                 fix_problem(ctx, PR_0_NO_FRAGMENTS, &pctx);
 366                 ctx->flags |= E2F_FLAG_ABORT;
 367                 return;
 368         }
 369
 370         should_be = sb->s_frags_per_group >>
 371                 (sb->s_log_block_size - sb->s_log_frag_size);
 372         if (sb->s_blocks_per_group != should_be) {
 373                 pctx.blk = sb->s_blocks_per_group;
 374                 pctx.blk2 = should_be;
 375                 fix_problem(ctx, PR_0_BLOCKS_PER_GROUP, &pctx);
 376                 ctx->flags |= E2F_FLAG_ABORT;
 377                 return;
 378         }
 379
 380         should_be = (sb->s_log_block_size == 0) ? 1 : 0;
 381         if (sb->s_first_data_block != should_be) {
 382                 pctx.blk = sb->s_first_data_block;
 383                 pctx.blk2 = should_be;
 384                 fix_problem(ctx, PR_0_FIRST_DATA_BLOCK, &pctx);
 385                 ctx->flags |= E2F_FLAG_ABORT;
 386                 return;
 387         }
 388
 389         should_be = sb->s_inodes_per_group * fs->group_desc_count;
 390         if (sb->s_inodes_count != should_be) {
 391                 pctx.ino = sb->s_inodes_count;
 392                 pctx.ino2 = should_be;
 393                 if (fix_problem(ctx, PR_0_INODE_COUNT_WRONG, &pctx)) {
 394                         sb->s_inodes_count = should_be;
 395                         ext2fs_mark_super_dirty(fs);
 396                 }
 397         }
 398
 399         /*
 400          * Verify the group descriptors....
 401          */
 402         first_block =  fs->super->s_first_data_block;
 403         last_block = first_block + blocks_per_group;
 404
 405         for (i = 0; i < fs->group_desc_count; i++) {
 406                 pctx.group = i;
 407
 408                 if (i == fs->group_desc_count - 1)
 409                         last_block = fs->super->s_blocks_count;
 410                 if ((fs->group_desc[i].bg_block_bitmap < first_block) ||
 411                     (fs->group_desc[i].bg_block_bitmap >= last_block)) {
 412                         pctx.blk = fs->group_desc[i].bg_block_bitmap;
 413                         if (fix_problem(ctx, PR_0_BB_NOT_GROUP, &pctx)) {
 414                                 fs->group_desc[i].bg_block_bitmap = 0;
 415                                 ctx->invalid_block_bitmap_flag[i]++;
 416                                 ctx->invalid_bitmaps++;
 417                         }
 418                 }
 419                 if ((fs->group_desc[i].bg_inode_bitmap < first_block) ||
 420                     (fs->group_desc[i].bg_inode_bitmap >= last_block)) {
 421                         pctx.blk = fs->group_desc[i].bg_inode_bitmap;
 422                         if (fix_problem(ctx, PR_0_IB_NOT_GROUP, &pctx)) {
 423                                 fs->group_desc[i].bg_inode_bitmap = 0;
 424                                 ctx->invalid_inode_bitmap_flag[i]++;
 425                                 ctx->invalid_bitmaps++;
 426                         }
 427                 }
 428                 if ((fs->group_desc[i].bg_inode_table < first_block) ||
 429                     ((fs->group_desc[i].bg_inode_table +
 430                       fs->inode_blocks_per_group - 1) >= last_block)) {
 431                         pctx.blk = fs->group_desc[i].bg_inode_table;
 432                         if (fix_problem(ctx, PR_0_ITABLE_NOT_GROUP, &pctx)) {
 433                                 fs->group_desc[i].bg_inode_table = 0;
 434                                 ctx->invalid_inode_table_flag[i]++;
 435                                 ctx->invalid_bitmaps++;
 436                         }
 437                 }
 438                 first_block += fs->super->s_blocks_per_group;
 439                 last_block += fs->super->s_blocks_per_group;
 440         }
 441         /*
 442          * If we have invalid bitmaps, set the error state of the
 443          * filesystem.
 444          */
 445         if (ctx->invalid_bitmaps && !(ctx->options & E2F_OPT_READONLY)) {
 446                 fs->super->s_state &= ~EXT2_VALID_FS;
 447                 ext2fs_mark_super_dirty(fs);
 448         }
 449
 450         clear_problem_context(&pctx);
 451
 452 #ifndef EXT2_SKIP_UUID
 453         /*
 454          * If the UUID field isn't assigned, assign it.
 455          */
 456         if (!(ctx->options & E2F_OPT_READONLY) && uuid_is_null(sb->s_uuid)) {
 457                 if (fix_problem(ctx, PR_0_ADD_UUID, &pctx)) {
 458                         uuid_generate(sb->s_uuid);
 459                         ext2fs_mark_super_dirty(fs);
 460                 }
 461         }
 462 #endif
 463
 464         /*
 465          * For the Hurd, check to see if the filetype option is set,
 466          * since it doesn't support it.
 467          */
 468         if (!(ctx->options & E2F_OPT_READONLY) &&
 469             fs->super->s_creator_os == EXT2_OS_HURD &&
 470             (fs->super->s_feature_incompat &
 471              EXT2_FEATURE_INCOMPAT_FILETYPE)) {
 472                 if (fix_problem(ctx, PR_0_HURD_CLEAR_FILETYPE, &pctx)) {
 473                         fs->super->s_feature_incompat &=
 474                                 ~EXT2_FEATURE_INCOMPAT_FILETYPE;
 475                         ext2fs_mark_super_dirty(fs);
 476
 477                 }
 478         }
 479
 480         /*
 481          * If we have any of the compatibility flags set, we need to have a
 482          * revision 1 filesystem.  Most kernels will not check the flags on
 483          * a rev 0 filesystem and we may have corruption issues because of
 484          * the incompatible changes to the filesystem.
 485          */
 486         if (!(ctx->options & E2F_OPT_READONLY) &&
 487             fs->super->s_rev_level == EXT2_GOOD_OLD_REV &&
 488             (fs->super->s_feature_compat ||
 489              fs->super->s_feature_ro_compat ||
 490              fs->super->s_feature_incompat) &&
 491             fix_problem(ctx, PR_0_FS_REV_LEVEL, &pctx)) {
 492                 ext2fs_update_dynamic_rev(fs);
 493                 ext2fs_mark_super_dirty(fs);
 494         }
 495
 496         /*
 497          * Clean up any orphan inodes, if present.
 498          */
 499         if (!(ctx->options & E2F_OPT_READONLY) && release_orphan_inodes(ctx)) {
 500                 fs->super->s_state &= ~EXT2_VALID_FS;
 501                 ext2fs_mark_super_dirty(fs);
 502         }
 503
 504         return;
 505 }
 506
 507