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  * helper function to release an inode
  43  */
  44 struct process_block_struct {
  45         e2fsck_t        ctx;
  46         char            *buf;
  47         struct problem_context *pctx;
  48         int             truncating;
  49         int             truncate_offset;
  50         e2_blkcnt_t     truncate_block;
  51         int             truncated_blocks;
  52         int             abort;
  53         errcode_t       errcode;
  54 };
  55
  56 static int release_inode_block(ext2_filsys fs,
  57                                blk_t    *block_nr,
  58                                e2_blkcnt_t blockcnt,
  59                                blk_t    ref_blk EXT2FS_ATTR((unused)),
  60                                int      ref_offset EXT2FS_ATTR((unused)),
  61                                void *priv_data)
  62 {
  63         struct process_block_struct *pb;
  64         e2fsck_t                ctx;
  65         struct problem_context  *pctx;
  66         blk_t                   blk = *block_nr;
  67         int                     retval = 0;
  68
  69         pb = (struct process_block_struct *) priv_data;
  70         ctx = pb->ctx;
  71         pctx = pb->pctx;
  72
  73         pctx->blk = blk;
  74         pctx->blkcount = blockcnt;
  75
  76         if (HOLE_BLKADDR(blk))
  77                 return 0;
  78
  79         if ((blk < fs->super->s_first_data_block) ||
  80             (blk >= ext2fs_blocks_count(fs->super))) {
  81                 fix_problem(ctx, PR_0_ORPHAN_ILLEGAL_BLOCK_NUM, pctx);
  82         return_abort:
  83                 pb->abort = 1;
  84                 return BLOCK_ABORT;
  85         }
  86
  87         if (!ext2fs_test_block_bitmap2(fs->block_map, blk)) {
  88                 fix_problem(ctx, PR_0_ORPHAN_ALREADY_CLEARED_BLOCK, pctx);
  89                 goto return_abort;
  90         }
  91
  92         /*
  93          * If we are deleting an orphan, then we leave the fields alone.
  94          * If we are truncating an orphan, then update the inode fields
  95          * and clean up any partial block data.
  96          */
  97         if (pb->truncating) {
  98                 /*
  99                  * We only remove indirect blocks if they are
 100                  * completely empty.
 101                  */
 102                 if (blockcnt < 0) {
 103                         int     i, limit;
 104                         blk_t   *bp;
 105
 106                         pb->errcode = io_channel_read_blk64(fs->io, blk, 1,
 107                                                         pb->buf);
 108                         if (pb->errcode)
 109                                 goto return_abort;
 110
 111                         limit = fs->blocksize >> 2;
 112                         for (i = 0, bp = (blk_t *) pb->buf;
 113                              i < limit;  i++, bp++)
 114                                 if (*bp)
 115                                         return 0;
 116                 }
 117                 /*
 118                  * We don't remove direct blocks until we've reached
 119                  * the truncation block.
 120                  */
 121                 if (blockcnt >= 0 && blockcnt < pb->truncate_block)
 122                         return 0;
 123                 /*
 124                  * If part of the last block needs truncating, we do
 125                  * it here.
 126                  */
 127                 if ((blockcnt == pb->truncate_block) && pb->truncate_offset) {
 128                         pb->errcode = io_channel_read_blk64(fs->io, blk, 1,
 129                                                         pb->buf);
 130                         if (pb->errcode)
 131                                 goto return_abort;
 132                         memset(pb->buf + pb->truncate_offset, 0,
 133                                fs->blocksize - pb->truncate_offset);
 134                         pb->errcode = io_channel_write_blk64(fs->io, blk, 1,
 135                                                          pb->buf);
 136                         if (pb->errcode)
 137                                 goto return_abort;
 138                 }
 139                 pb->truncated_blocks++;
 140                 *block_nr = 0;
 141                 retval |= BLOCK_CHANGED;
 142         }
 143
 144         ext2fs_block_alloc_stats2(fs, blk, -1);
 145         return retval;
 146 }
 147
 148 /*
 149  * This function releases an inode.  Returns 1 if an inconsistency was
 150  * found.  If the inode has a link count, then it is being truncated and
 151  * not deleted.
 152  */
 153 static int release_inode_blocks(e2fsck_t ctx, ext2_ino_t ino,
 154                                 struct ext2_inode *inode, char *block_buf,
 155                                 struct problem_context *pctx)
 156 {
 157         struct process_block_struct     pb;
 158         ext2_filsys                     fs = ctx->fs;
 159         errcode_t                       retval;
 160         __u32                           count;
 161
 162         if (!ext2fs_inode_has_valid_blocks(inode))
 163                 return 0;
 164
 165         pb.buf = block_buf + 3 * ctx->fs->blocksize;
 166         pb.ctx = ctx;
 167         pb.abort = 0;
 168         pb.errcode = 0;
 169         pb.pctx = pctx;
 170         if (inode->i_links_count) {
 171                 pb.truncating = 1;
 172                 pb.truncate_block = (e2_blkcnt_t)
 173                         ((((long long)inode->i_size_high << 32) +
 174                           inode->i_size + fs->blocksize - 1) /
 175                          fs->blocksize);
 176                 pb.truncate_offset = inode->i_size % fs->blocksize;
 177         } else {
 178                 pb.truncating = 0;
 179                 pb.truncate_block = 0;
 180                 pb.truncate_offset = 0;
 181         }
 182         pb.truncated_blocks = 0;
 183         retval = ext2fs_block_iterate2(fs, ino, BLOCK_FLAG_DEPTH_TRAVERSE,
 184                                       block_buf, release_inode_block, &pb);
 185         if (retval) {
 186                 com_err("release_inode_blocks", retval,
 187                         _("while calling ext2fs_block_iterate for inode %d"),
 188                         ino);
 189                 return 1;
 190         }
 191         if (pb.abort)
 192                 return 1;
 193
 194         /* Refresh the inode since ext2fs_block_iterate may have changed it */
 195         e2fsck_read_inode(ctx, ino, inode, "release_inode_blocks");
 196
 197         if (pb.truncated_blocks)
 198                 ext2fs_iblk_sub_blocks(fs, inode, pb.truncated_blocks);
 199
 200         if (ext2fs_file_acl_block(inode)) {
 201                 retval = ext2fs_adjust_ea_refcount(fs, ext2fs_file_acl_block(inode),
 202                                                    block_buf, -1, &count);
 203                 if (retval == EXT2_ET_BAD_EA_BLOCK_NUM) {
 204                         retval = 0;
 205                         count = 1;
 206                 }
 207                 if (retval) {
 208                         com_err("release_inode_blocks", retval,
 209                 _("while calling ext2fs_adjust_ea_refcount for inode %d"),
 210                                 ino);
 211                         return 1;
 212                 }
 213                 if (count == 0)
 214                         ext2fs_block_alloc_stats2(fs,
 215                                                  ext2fs_file_acl_block(inode),
 216                                                  -1);
 217                 ext2fs_file_acl_block_set(inode, 0);
 218         }
 219         return 0;
 220 }
 221
 222 /*
 223  * This function releases all of the orphan inodes.  It returns 1 if
 224  * it hit some error, and 0 on success.
 225  */
 226 static int release_orphan_inodes(e2fsck_t ctx)
 227 {
 228         ext2_filsys fs = ctx->fs;
 229         ext2_ino_t      ino, next_ino;
 230         struct ext2_inode inode;
 231         struct problem_context pctx;
 232         char *block_buf;
 233
 234         if ((ino = fs->super->s_last_orphan) == 0)
 235                 return 0;
 236
 237         /*
 238          * Win or lose, we won't be using the head of the orphan inode
 239          * list again.
 240          */
 241         fs->super->s_last_orphan = 0;
 242         ext2fs_mark_super_dirty(fs);
 243
 244         /*
 245          * If the filesystem contains errors, don't run the orphan
 246          * list, since the orphan list can't be trusted; and we're
 247          * going to be running a full e2fsck run anyway...
 248          */
 249         if (fs->super->s_state & EXT2_ERROR_FS)
 250                 return 0;
 251
 252         if ((ino < EXT2_FIRST_INODE(fs->super)) ||
 253             (ino > fs->super->s_inodes_count)) {
 254                 clear_problem_context(&pctx);
 255                 pctx.ino = ino;
 256                 fix_problem(ctx, PR_0_ORPHAN_ILLEGAL_HEAD_INODE, &pctx);
 257                 return 1;
 258         }
 259
 260         block_buf = (char *) e2fsck_allocate_memory(ctx, fs->blocksize * 4,
 261                                                     "block iterate buffer");
 262         e2fsck_read_bitmaps(ctx);
 263
 264         while (ino) {
 265                 e2fsck_read_inode(ctx, ino, &inode, "release_orphan_inodes");
 266                 clear_problem_context(&pctx);
 267                 pctx.ino = ino;
 268                 pctx.inode = &inode;
 269                 pctx.str = inode.i_links_count ? _("Truncating") :
 270                         _("Clearing");
 271
 272                 fix_problem(ctx, PR_0_ORPHAN_CLEAR_INODE, &pctx);
 273
 274                 next_ino = inode.i_dtime;
 275                 if (next_ino &&
 276                     ((next_ino < EXT2_FIRST_INODE(fs->super)) ||
 277                      (next_ino > fs->super->s_inodes_count))) {
 278                         pctx.ino = next_ino;
 279                         fix_problem(ctx, PR_0_ORPHAN_ILLEGAL_INODE, &pctx);
 280                         goto return_abort;
 281                 }
 282
 283                 if (release_inode_blocks(ctx, ino, &inode, block_buf, &pctx))
 284                         goto return_abort;
 285
 286                 if (!inode.i_links_count) {
 287                         ext2fs_inode_alloc_stats2(fs, ino, -1,
 288                                                   LINUX_S_ISDIR(inode.i_mode));
 289                         inode.i_dtime = ctx->now;
 290                 } else {
 291                         inode.i_dtime = 0;
 292                 }
 293                 e2fsck_write_inode(ctx, ino, &inode, "delete_file");
 294                 ino = next_ino;
 295         }
 296         ext2fs_free_mem(&block_buf);
 297         return 0;
 298 return_abort:
 299         ext2fs_free_mem(&block_buf);
 300         return 1;
 301 }
 302
 303 /*
 304  * Check the resize inode to make sure it is sane.  We check both for
 305  * the case where on-line resizing is not enabled (in which case the
 306  * resize inode should be cleared) as well as the case where on-line
 307  * resizing is enabled.
 308  */
 309 void check_resize_inode(e2fsck_t ctx)
 310 {
 311         ext2_filsys fs = ctx->fs;
 312         struct ext2_inode inode;
 313         struct problem_context  pctx;
 314         int             i, gdt_off, ind_off;
 315         dgrp_t          j;
 316         blk_t           blk, pblk, expect;
 317         __u32           *dind_buf = 0, *ind_buf;
 318         errcode_t       retval;
 319
 320         clear_problem_context(&pctx);
 321
 322         /*
 323          * If the resize inode feature isn't set, then
 324          * s_reserved_gdt_blocks must be zero.
 325          */
 326         if (!(fs->super->s_feature_compat &
 327               EXT2_FEATURE_COMPAT_RESIZE_INODE)) {
 328                 if (fs->super->s_reserved_gdt_blocks) {
 329                         pctx.num = fs->super->s_reserved_gdt_blocks;
 330                         if (fix_problem(ctx, PR_0_NONZERO_RESERVED_GDT_BLOCKS,
 331                                         &pctx)) {
 332                                 fs->super->s_reserved_gdt_blocks = 0;
 333                                 ext2fs_mark_super_dirty(fs);
 334                         }
 335                 }
 336         }
 337
 338         /* Read the resize inode */
 339         pctx.ino = EXT2_RESIZE_INO;
 340         retval = ext2fs_read_inode(fs, EXT2_RESIZE_INO, &inode);
 341         if (retval) {
 342                 if (fs->super->s_feature_compat &
 343                     EXT2_FEATURE_COMPAT_RESIZE_INODE)
 344                         ctx->flags |= E2F_FLAG_RESIZE_INODE;
 345                 return;
 346         }
 347
 348         /*
 349          * If the resize inode feature isn't set, check to make sure
 350          * the resize inode is cleared; then we're done.
 351          */
 352         if (!(fs->super->s_feature_compat &
 353               EXT2_FEATURE_COMPAT_RESIZE_INODE)) {
 354                 for (i=0; i < EXT2_N_BLOCKS; i++) {
 355                         if (inode.i_block[i])
 356                                 break;
 357                 }
 358                 if ((i < EXT2_N_BLOCKS) &&
 359                     fix_problem(ctx, PR_0_CLEAR_RESIZE_INODE, &pctx)) {
 360                         memset(&inode, 0, sizeof(inode));
 361                         e2fsck_write_inode(ctx, EXT2_RESIZE_INO, &inode,
 362                                            "clear_resize");
 363                 }
 364                 return;
 365         }
 366
 367         /*
 368          * The resize inode feature is enabled; check to make sure the
 369          * only block in use is the double indirect block
 370          */
 371         blk = inode.i_block[EXT2_DIND_BLOCK];
 372         for (i=0; i < EXT2_N_BLOCKS; i++) {
 373                 if (i != EXT2_DIND_BLOCK && inode.i_block[i])
 374                         break;
 375         }
 376         if ((i < EXT2_N_BLOCKS) || !blk || !inode.i_links_count ||
 377             !(inode.i_mode & LINUX_S_IFREG) ||
 378             (blk < fs->super->s_first_data_block ||
 379              blk >= ext2fs_blocks_count(fs->super))) {
 380         resize_inode_invalid:
 381                 if (fix_problem(ctx, PR_0_RESIZE_INODE_INVALID, &pctx)) {
 382                         memset(&inode, 0, sizeof(inode));
 383                         e2fsck_write_inode(ctx, EXT2_RESIZE_INO, &inode,
 384                                            "clear_resize");
 385                         ctx->flags |= E2F_FLAG_RESIZE_INODE;
 386                 }
 387                 if (!(ctx->options & E2F_OPT_READONLY)) {
 388                         fs->super->s_state &= ~EXT2_VALID_FS;
 389                         ext2fs_mark_super_dirty(fs);
 390                 }
 391                 goto cleanup;
 392         }
 393         dind_buf = (__u32 *) e2fsck_allocate_memory(ctx, fs->blocksize * 2,
 394                                                     "resize dind buffer");
 395         ind_buf = (__u32 *) ((char *) dind_buf + fs->blocksize);
 396
 397         retval = ext2fs_read_ind_block(fs, blk, dind_buf);
 398         if (retval)
 399                 goto resize_inode_invalid;
 400
 401         gdt_off = fs->desc_blocks;
 402         pblk = fs->super->s_first_data_block + 1 + fs->desc_blocks;
 403         for (i = 0; i < fs->super->s_reserved_gdt_blocks / 4;
 404              i++, gdt_off++, pblk++) {
 405                 gdt_off %= fs->blocksize/4;
 406                 if (dind_buf[gdt_off] != pblk)
 407                         goto resize_inode_invalid;
 408                 retval = ext2fs_read_ind_block(fs, pblk, ind_buf);
 409                 if (retval)
 410                         goto resize_inode_invalid;
 411                 ind_off = 0;
 412                 for (j = 1; j < fs->group_desc_count; j++) {
 413                         if (!ext2fs_bg_has_super(fs, j))
 414                                 continue;
 415                         expect = pblk + (j * fs->super->s_blocks_per_group);
 416                         if (ind_buf[ind_off] != expect)
 417                                 goto resize_inode_invalid;
 418                         ind_off++;
 419                 }
 420         }
 421
 422 cleanup:
 423         if (dind_buf)
 424                 ext2fs_free_mem(&dind_buf);
 425
 426  }
 427
 428 /*
 429  * This function checks the dirhash signed/unsigned hint if necessary.
 430  */
 431 static void e2fsck_fix_dirhash_hint(e2fsck_t ctx)
 432 {
 433         struct ext2_super_block *sb = ctx->fs->super;
 434         struct problem_context pctx;
 435         char    c;
 436
 437         if ((ctx->options & E2F_OPT_READONLY) ||
 438             !(sb->s_feature_compat & EXT2_FEATURE_COMPAT_DIR_INDEX) ||
 439             (sb->s_flags & (EXT2_FLAGS_SIGNED_HASH|EXT2_FLAGS_UNSIGNED_HASH)))
 440                 return;
 441
 442         c = (char) 255;
 443
 444         clear_problem_context(&pctx);
 445         if (fix_problem(ctx, PR_0_DIRHASH_HINT, &pctx)) {
 446                 if (((int) c) == -1) {
 447                         sb->s_flags |= EXT2_FLAGS_SIGNED_HASH;
 448                 } else {
 449                         sb->s_flags |= EXT2_FLAGS_UNSIGNED_HASH;
 450                 }
 451                 ext2fs_mark_super_dirty(ctx->fs);
 452         }
 453 }
 454
 455
 456 void check_super_block(e2fsck_t ctx)
 457 {
 458         ext2_filsys fs = ctx->fs;
 459         blk_t   first_block, last_block;
 460         struct ext2_super_block *sb = fs->super;
 461         problem_t       problem;
 462         blk_t   blocks_per_group = fs->super->s_blocks_per_group;
 463         blk_t   bpg_max;
 464         int     inodes_per_block;
 465         int     ipg_max;
 466         int     inode_size;
 467         int     accept_time_fudge;
 468         dgrp_t  i;
 469         blk_t   should_be;
 470         struct problem_context  pctx;
 471         blk_t   free_blocks = 0;
 472         ino_t   free_inodes = 0;
 473         int     csum_flag, clear_test_fs_flag;
 474
 475         inodes_per_block = EXT2_INODES_PER_BLOCK(fs->super);
 476         ipg_max = inodes_per_block * (blocks_per_group - 4);
 477         if (ipg_max > EXT2_MAX_INODES_PER_GROUP(sb))
 478                 ipg_max = EXT2_MAX_INODES_PER_GROUP(sb);
 479         bpg_max = 8 * EXT2_BLOCK_SIZE(sb);
 480         if (bpg_max > EXT2_MAX_BLOCKS_PER_GROUP(sb))
 481                 bpg_max = EXT2_MAX_BLOCKS_PER_GROUP(sb);
 482
 483         ctx->invalid_inode_bitmap_flag = (int *) e2fsck_allocate_memory(ctx,
 484                  sizeof(int) * fs->group_desc_count, "invalid_inode_bitmap");
 485         ctx->invalid_block_bitmap_flag = (int *) e2fsck_allocate_memory(ctx,
 486                  sizeof(int) * fs->group_desc_count, "invalid_block_bitmap");
 487         ctx->invalid_inode_table_flag = (int *) e2fsck_allocate_memory(ctx,
 488                 sizeof(int) * fs->group_desc_count, "invalid_inode_table");
 489
 490         clear_problem_context(&pctx);
 491
 492         /*
 493          * Verify the super block constants...
 494          */
 495         check_super_value(ctx, "inodes_count", sb->s_inodes_count,
 496                           MIN_CHECK, 1, 0);
 497         check_super_value(ctx, "blocks_count", ext2fs_blocks_count(sb),
 498                           MIN_CHECK, 1, 0);
 499         check_super_value(ctx, "first_data_block", sb->s_first_data_block,
 500                           MAX_CHECK, 0, ext2fs_blocks_count(sb));
 501         check_super_value(ctx, "log_block_size", sb->s_log_block_size,
 502                           MIN_CHECK | MAX_CHECK, 0,
 503                           EXT2_MAX_BLOCK_LOG_SIZE - EXT2_MIN_BLOCK_LOG_SIZE);
 504         check_super_value(ctx, "log_frag_size", sb->s_log_frag_size,
 505                           MIN_CHECK | MAX_CHECK, 0, sb->s_log_block_size);
 506         check_super_value(ctx, "frags_per_group", sb->s_frags_per_group,
 507                           MIN_CHECK | MAX_CHECK, sb->s_blocks_per_group,
 508                           bpg_max);
 509         check_super_value(ctx, "blocks_per_group", sb->s_blocks_per_group,
 510                           MIN_CHECK | MAX_CHECK, 8, bpg_max);
 511         check_super_value(ctx, "inodes_per_group", sb->s_inodes_per_group,
 512                           MIN_CHECK | MAX_CHECK, inodes_per_block, ipg_max);
 513         check_super_value(ctx, "r_blocks_count", ext2fs_r_blocks_count(sb),
 514                           MAX_CHECK, 0, ext2fs_blocks_count(sb) / 2);
 515         check_super_value(ctx, "reserved_gdt_blocks",
 516                           sb->s_reserved_gdt_blocks, MAX_CHECK, 0,
 517                           fs->blocksize/4);
 518         if (sb->s_rev_level > EXT2_GOOD_OLD_REV)
 519                 check_super_value(ctx, "first_ino", sb->s_first_ino,
 520                                   MIN_CHECK | MAX_CHECK,
 521                                   EXT2_GOOD_OLD_FIRST_INO, sb->s_inodes_count);
 522         inode_size = EXT2_INODE_SIZE(sb);
 523         check_super_value(ctx, "inode_size",
 524                           inode_size, MIN_CHECK | MAX_CHECK,
 525                           EXT2_GOOD_OLD_INODE_SIZE, fs->blocksize);
 526         if (inode_size & (inode_size - 1)) {
 527                 pctx.num = inode_size;
 528                 pctx.str = "inode_size";
 529                 fix_problem(ctx, PR_0_MISC_CORRUPT_SUPER, &pctx);
 530                 ctx->flags |= E2F_FLAG_ABORT; /* never get here! */
 531                 return;
 532         }
 533
 534         if ((ctx->flags & E2F_FLAG_GOT_DEVSIZE) &&
 535             (ctx->num_blocks < ext2fs_blocks_count(sb))) {
 536                 pctx.blk = ext2fs_blocks_count(sb);
 537                 pctx.blk2 = ctx->num_blocks;
 538                 if (fix_problem(ctx, PR_0_FS_SIZE_WRONG, &pctx)) {
 539                         ctx->flags |= E2F_FLAG_ABORT;
 540                         return;
 541                 }
 542         }
 543
 544         if (sb->s_log_block_size != (__u32) sb->s_log_frag_size) {
 545                 pctx.blk = EXT2_BLOCK_SIZE(sb);
 546                 pctx.blk2 = EXT2_FRAG_SIZE(sb);
 547                 fix_problem(ctx, PR_0_NO_FRAGMENTS, &pctx);
 548                 ctx->flags |= E2F_FLAG_ABORT;
 549                 return;
 550         }
 551
 552         should_be = sb->s_frags_per_group >>
 553                 (sb->s_log_block_size - sb->s_log_frag_size);
 554         if (sb->s_blocks_per_group != should_be) {
 555                 pctx.blk = sb->s_blocks_per_group;
 556                 pctx.blk2 = should_be;
 557                 fix_problem(ctx, PR_0_BLOCKS_PER_GROUP, &pctx);
 558                 ctx->flags |= E2F_FLAG_ABORT;
 559                 return;
 560         }
 561
 562         should_be = (sb->s_log_block_size == 0) ? 1 : 0;
 563         if (sb->s_first_data_block != should_be) {
 564                 pctx.blk = sb->s_first_data_block;
 565                 pctx.blk2 = should_be;
 566                 fix_problem(ctx, PR_0_FIRST_DATA_BLOCK, &pctx);
 567                 ctx->flags |= E2F_FLAG_ABORT;
 568                 return;
 569         }
 570
 571         should_be = sb->s_inodes_per_group * fs->group_desc_count;
 572         if (sb->s_inodes_count != should_be) {
 573                 pctx.ino = sb->s_inodes_count;
 574                 pctx.ino2 = should_be;
 575                 if (fix_problem(ctx, PR_0_INODE_COUNT_WRONG, &pctx)) {
 576                         sb->s_inodes_count = should_be;
 577                         ext2fs_mark_super_dirty(fs);
 578                 }
 579         }
 580
 581         /*
 582          * Verify the group descriptors....
 583          */
 584         first_block = sb->s_first_data_block;
 585         last_block = ext2fs_blocks_count(sb)-1;
 586
 587         csum_flag = EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 588                                                EXT4_FEATURE_RO_COMPAT_GDT_CSUM);
 589         for (i = 0; i < fs->group_desc_count; i++) {
 590                 pctx.group = i;
 591
 592                 if (!EXT2_HAS_INCOMPAT_FEATURE(fs->super,
 593                                                EXT4_FEATURE_INCOMPAT_FLEX_BG)) {
 594                         first_block = ext2fs_group_first_block2(fs, i);
 595                         last_block = ext2fs_group_last_block2(fs, i);
 596                 }
 597
 598                 if ((ext2fs_block_bitmap_loc(fs, i) < first_block) ||
 599                     (ext2fs_block_bitmap_loc(fs, i) > last_block)) {
 600                         pctx.blk = ext2fs_block_bitmap_loc(fs, i);
 601                         if (fix_problem(ctx, PR_0_BB_NOT_GROUP, &pctx))
 602                                 ext2fs_block_bitmap_loc_set(fs, i, 0);
 603                 }
 604                 if (ext2fs_block_bitmap_loc(fs, i) == 0) {
 605                         ctx->invalid_block_bitmap_flag[i]++;
 606                         ctx->invalid_bitmaps++;
 607                 }
 608                 if ((ext2fs_inode_bitmap_loc(fs, i) < first_block) ||
 609                     (ext2fs_inode_bitmap_loc(fs, i) > last_block)) {
 610                         pctx.blk = ext2fs_inode_bitmap_loc(fs, i);
 611                         if (fix_problem(ctx, PR_0_IB_NOT_GROUP, &pctx))
 612                                 ext2fs_inode_bitmap_loc_set(fs, i, 0);
 613                 }
 614                 if (ext2fs_inode_bitmap_loc(fs, i) == 0) {
 615                         ctx->invalid_inode_bitmap_flag[i]++;
 616                         ctx->invalid_bitmaps++;
 617                 }
 618                 if ((ext2fs_inode_table_loc(fs, i) < first_block) ||
 619                     ((ext2fs_inode_table_loc(fs, i) +
 620                       fs->inode_blocks_per_group - 1) > last_block)) {
 621                         pctx.blk = ext2fs_inode_table_loc(fs, i);
 622                         if (fix_problem(ctx, PR_0_ITABLE_NOT_GROUP, &pctx))
 623                                 ext2fs_inode_table_loc_set(fs, i, 0);
 624                 }
 625                 if (ext2fs_inode_table_loc(fs, i) == 0) {
 626                         ctx->invalid_inode_table_flag[i]++;
 627                         ctx->invalid_bitmaps++;
 628                 }
 629                 free_blocks += ext2fs_bg_free_blocks_count(fs, i);
 630                 free_inodes += ext2fs_bg_free_inodes_count(fs, i);
 631
 632                 if ((ext2fs_bg_free_blocks_count(fs, i) > sb->s_blocks_per_group) ||
 633                     (ext2fs_bg_free_inodes_count(fs, i) > sb->s_inodes_per_group) ||
 634                     (ext2fs_bg_used_dirs_count(fs, i) > sb->s_inodes_per_group))
 635                         ext2fs_unmark_valid(fs);
 636
 637                 should_be = 0;
 638                 if (!ext2fs_group_desc_csum_verify(fs, i)) {
 639                         if (fix_problem(ctx, PR_0_GDT_CSUM, &pctx)) {
 640                                 ext2fs_bg_flags_clear(fs, i, EXT2_BG_BLOCK_UNINIT);
 641                                 ext2fs_bg_flags_clear(fs, i, EXT2_BG_INODE_UNINIT);
 642                                 ext2fs_bg_itable_unused_set(fs, i, 0);
 643                                 should_be = 1;
 644                         }
 645                         ext2fs_unmark_valid(fs);
 646                 }
 647
 648                 if (!csum_flag &&
 649                     (ext2fs_bg_flags_test(fs, i, EXT2_BG_BLOCK_UNINIT) ||
 650                      ext2fs_bg_flags_test(fs, i, EXT2_BG_INODE_UNINIT) ||
 651                      ext2fs_bg_itable_unused(fs, i) != 0)) {
 652                         if (fix_problem(ctx, PR_0_GDT_UNINIT, &pctx)) {
 653                                 ext2fs_bg_flags_clear(fs, i, EXT2_BG_BLOCK_UNINIT);
 654                                 ext2fs_bg_flags_clear(fs, i, EXT2_BG_INODE_UNINIT);
 655                                 ext2fs_bg_itable_unused_set(fs, i, 0);
 656                                 should_be = 1;
 657                         }
 658                         ext2fs_unmark_valid(fs);
 659                 }
 660
 661                 if (i == fs->group_desc_count - 1 &&
 662                     ext2fs_bg_flags_test(fs, i, EXT2_BG_BLOCK_UNINIT)) {
 663                         if (fix_problem(ctx, PR_0_BB_UNINIT_LAST, &pctx)) {
 664                                 ext2fs_bg_flags_clear(fs, i, EXT2_BG_BLOCK_UNINIT);
 665                                 should_be = 1;
 666                         }
 667                         ext2fs_unmark_valid(fs);
 668                 }
 669
 670                 if (ext2fs_bg_flags_test(fs, i, EXT2_BG_BLOCK_UNINIT) &&
 671                     !ext2fs_bg_flags_test(fs, i, EXT2_BG_INODE_UNINIT)) {
 672                         if (fix_problem(ctx, PR_0_BB_UNINIT_IB_INIT, &pctx)) {
 673                                 ext2fs_bg_flags_clear(fs, i, EXT2_BG_BLOCK_UNINIT);
 674                                 should_be = 1;
 675                         }
 676                         ext2fs_unmark_valid(fs);
 677                 }
 678
 679                 if (csum_flag &&
 680                     (ext2fs_bg_itable_unused(fs, i) > ext2fs_bg_free_inodes_count(fs, i) ||
 681                      ext2fs_bg_itable_unused(fs, i) > sb->s_inodes_per_group)) {
 682                         pctx.blk = ext2fs_bg_itable_unused(fs, i);
 683                         if (fix_problem(ctx, PR_0_GDT_ITABLE_UNUSED, &pctx)) {
 684                                 ext2fs_bg_itable_unused_set(fs, i, 0);
 685                                 should_be = 1;
 686                         }
 687                         ext2fs_unmark_valid(fs);
 688                 }
 689
 690                 if (should_be)
 691                         ext2fs_group_desc_csum_set(fs, i);
 692                 /* If the user aborts e2fsck by typing ^C, stop right away */
 693                 if (ctx->flags & E2F_FLAG_SIGNAL_MASK)
 694                         return;
 695         }
 696
 697         /*
 698          * Update the global counts from the block group counts.  This
 699          * is needed for an experimental patch which eliminates
 700          * locking the entire filesystem when allocating blocks or
 701          * inodes; if the filesystem is not unmounted cleanly, the
 702          * global counts may not be accurate.
 703          */
 704         if ((free_blocks != ext2fs_free_blocks_count(sb)) ||
 705             (free_inodes != sb->s_free_inodes_count)) {
 706                 if (ctx->options & E2F_OPT_READONLY)
 707                         ext2fs_unmark_valid(fs);
 708                 else {
 709                         ext2fs_free_blocks_count_set(sb, free_blocks);
 710                         sb->s_free_inodes_count = free_inodes;
 711                         ext2fs_mark_super_dirty(fs);
 712                 }
 713         }
 714
 715         if ((ext2fs_free_blocks_count(sb) > ext2fs_blocks_count(sb)) ||
 716             (sb->s_free_inodes_count > sb->s_inodes_count))
 717                 ext2fs_unmark_valid(fs);
 718
 719
 720         /*
 721          * If we have invalid bitmaps, set the error state of the
 722          * filesystem.
 723          */
 724         if (ctx->invalid_bitmaps && !(ctx->options & E2F_OPT_READONLY)) {
 725                 sb->s_state &= ~EXT2_VALID_FS;
 726                 ext2fs_mark_super_dirty(fs);
 727         }
 728
 729         clear_problem_context(&pctx);
 730
 731 #ifndef EXT2_SKIP_UUID
 732         /*
 733          * If the UUID field isn't assigned, assign it.
 734          */
 735         if (!(ctx->options & E2F_OPT_READONLY) && uuid_is_null(sb->s_uuid)) {
 736                 if (fix_problem(ctx, PR_0_ADD_UUID, &pctx)) {
 737                         uuid_generate(sb->s_uuid);
 738                         ext2fs_mark_super_dirty(fs);
 739                         fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
 740                 }
 741         }
 742 #endif
 743
 744         /*
 745          * Check to see if we should disable the test_fs flag
 746          */
 747         profile_get_boolean(ctx->profile, "options",
 748                             "clear_test_fs_flag", 0, 1,
 749                             &clear_test_fs_flag);
 750         if (!(ctx->options & E2F_OPT_READONLY) &&
 751             clear_test_fs_flag &&
 752             (fs->super->s_flags & EXT2_FLAGS_TEST_FILESYS) &&
 753             (fs_proc_check("ext4") || check_for_modules("ext4"))) {
 754                 if (fix_problem(ctx, PR_0_CLEAR_TESTFS_FLAG, &pctx)) {
 755                         fs->super->s_flags &= ~EXT2_FLAGS_TEST_FILESYS;
 756                         ext2fs_mark_super_dirty(fs);
 757                         fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
 758                 }
 759         }
 760
 761         /*
 762          * For the Hurd, check to see if the filetype option is set,
 763          * since it doesn't support it.
 764          */
 765         if (!(ctx->options & E2F_OPT_READONLY) &&
 766             fs->super->s_creator_os == EXT2_OS_HURD &&
 767             (fs->super->s_feature_incompat &
 768              EXT2_FEATURE_INCOMPAT_FILETYPE)) {
 769                 if (fix_problem(ctx, PR_0_HURD_CLEAR_FILETYPE, &pctx)) {
 770                         fs->super->s_feature_incompat &=
 771                                 ~EXT2_FEATURE_INCOMPAT_FILETYPE;
 772                         ext2fs_mark_super_dirty(fs);
 773                         fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
 774                 }
 775         }
 776
 777         /*
 778          * If we have any of the compatibility flags set, we need to have a
 779          * revision 1 filesystem.  Most kernels will not check the flags on
 780          * a rev 0 filesystem and we may have corruption issues because of
 781          * the incompatible changes to the filesystem.
 782          */
 783         if (!(ctx->options & E2F_OPT_READONLY) &&
 784             fs->super->s_rev_level == EXT2_GOOD_OLD_REV &&
 785             (fs->super->s_feature_compat ||
 786              fs->super->s_feature_ro_compat ||
 787              fs->super->s_feature_incompat) &&
 788             fix_problem(ctx, PR_0_FS_REV_LEVEL, &pctx)) {
 789                 ext2fs_update_dynamic_rev(fs);
 790                 ext2fs_mark_super_dirty(fs);
 791                 fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
 792         }
 793
 794         /*
 795          * Clean up any orphan inodes, if present.
 796          */
 797         if (!(ctx->options & E2F_OPT_READONLY) && release_orphan_inodes(ctx)) {
 798                 fs->super->s_state &= ~EXT2_VALID_FS;
 799                 ext2fs_mark_super_dirty(fs);
 800         }
 801
 802         /*
 803          * Unfortunately, due to Windows' unfortunate design decision
 804          * to configure the hardware clock to tick localtime, instead
 805          * of the more proper and less error-prone UTC time, many
 806          * users end up in the situation where the system clock is
 807          * incorrectly set at the time when e2fsck is run.
 808          *
 809          * Historically this was usually due to some distributions
 810          * having buggy init scripts and/or installers that didn't
 811          * correctly detect this case and take appropriate
 812          * countermeasures.  However, it's still possible, despite the
 813          * best efforts of init script and installer authors to not be
 814          * able to detect this misconfiguration, usually due to a
 815          * buggy or misconfigured virtualization manager or the
 816          * installer not having access to a network time server during
 817          * the installation process.  So by default, we allow the
 818          * superblock times to be fudged by up to 24 hours.  This can
 819          * be disabled by setting options.accept_time_fudge to the
 820          * boolean value of false in e2fsck.conf.  We also support
 821          * options.buggy_init_scripts for backwards compatibility.
 822          */
 823         profile_get_boolean(ctx->profile, "options", "accept_time_fudge",
 824                             0, 1, &accept_time_fudge);
 825         profile_get_boolean(ctx->profile, "options", "buggy_init_scripts",
 826                             0, accept_time_fudge, &accept_time_fudge);
 827         ctx->time_fudge = accept_time_fudge ? 86400 : 0;
 828
 829         /*
 830          * Check to see if the superblock last mount time or last
 831          * write time is in the future.
 832          */
 833         if (fs->super->s_mtime > (__u32) ctx->now) {
 834                 pctx.num = fs->super->s_mtime;
 835                 problem = PR_0_FUTURE_SB_LAST_MOUNT;
 836                 if (fs->super->s_mtime <= (__u32) ctx->now + ctx->time_fudge)
 837                         problem = PR_0_FUTURE_SB_LAST_MOUNT_FUDGED;
 838                 if (fix_problem(ctx, problem, &pctx)) {
 839                         fs->super->s_mtime = ctx->now;
 840                         ext2fs_mark_super_dirty(fs);
 841                 }
 842         }
 843         if (fs->super->s_wtime > (__u32) ctx->now) {
 844                 pctx.num = fs->super->s_wtime;
 845                 problem = PR_0_FUTURE_SB_LAST_WRITE;
 846                 if (fs->super->s_wtime <= (__u32) ctx->now + ctx->time_fudge)
 847                         problem = PR_0_FUTURE_SB_LAST_WRITE_FUDGED;
 848                 if (fix_problem(ctx, problem, &pctx)) {
 849                         fs->super->s_wtime = ctx->now;
 850                         ext2fs_mark_super_dirty(fs);
 851                 }
 852         }
 853
 854         /*
 855          * Move the ext3 journal file, if necessary.
 856          */
 857         e2fsck_move_ext3_journal(ctx);
 858
 859         /*
 860          * Fix journal hint, if necessary
 861          */
 862         e2fsck_fix_ext3_journal_hint(ctx);
 863
 864         /*
 865          * Add dirhash hint if necessary
 866          */
 867         e2fsck_fix_dirhash_hint(ctx);
 868
 869         return;
 870 }
 871
 872 /*
 873  * Check to see if we should backup the master sb to the backup super
 874  * blocks.  Returns non-zero if the sb should be backed up.
 875  */
 876
 877 /*
 878  * A few flags are set on the fly by the kernel, but only in the
 879  * primary superblock.  This is actually a bad thing, and we should
 880  * try to discourage it in the future.  In particular, for the newer
 881  * ext4 files, especially EXT4_FEATURE_RO_COMPAT_DIR_NLINK and
 882  * EXT3_FEATURE_INCOMPAT_EXTENTS.  So some of these may go away in the
 883  * future.  EXT3_FEATURE_INCOMPAT_RECOVER may also get set when
 884  * copying the primary superblock during online resize.
 885  *
 886  * The kernel will set EXT2_FEATURE_COMPAT_EXT_ATTR, but
 887  * unfortunately, we shouldn't ignore it since if it's not set in the
 888  * backup, the extended attributes in the filesystem will be stripped
 889  * away.
 890  */
 891 #define FEATURE_RO_COMPAT_IGNORE        (EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
 892                                          EXT4_FEATURE_RO_COMPAT_DIR_NLINK)
 893 #define FEATURE_INCOMPAT_IGNORE         (EXT3_FEATURE_INCOMPAT_EXTENTS| \
 894                                          EXT3_FEATURE_INCOMPAT_RECOVER)
 895
 896 int check_backup_super_block(e2fsck_t ctx)
 897 {
 898         ext2_filsys     fs = ctx->fs;
 899         errcode_t       retval;
 900         dgrp_t          g;
 901         blk_t           sb;
 902         int             ret = 0;
 903         char            buf[SUPERBLOCK_SIZE];
 904         struct ext2_super_block *backup_sb;
 905
 906         /*
 907          * If we are already writing out the backup blocks, then we
 908          * don't need to test.  Also, if the filesystem is invalid, or
 909          * the check was aborted or cancelled, we also don't want to
 910          * do the backup.  If the filesystem was opened read-only then
 911          * we can't do the backup.
 912          */
 913         if (((fs->flags & EXT2_FLAG_MASTER_SB_ONLY) == 0) ||
 914             !ext2fs_test_valid(fs) ||
 915             (fs->super->s_state & EXT2_ERROR_FS) ||
 916             (ctx->flags & (E2F_FLAG_ABORT | E2F_FLAG_CANCEL)) ||
 917             (ctx->options & E2F_OPT_READONLY))
 918                 return 0;
 919
 920         for (g = 1; g < fs->group_desc_count; g++) {
 921                 if (!ext2fs_bg_has_super(fs, g))
 922                         continue;
 923
 924                 sb = fs->super->s_first_data_block +
 925                         (g * fs->super->s_blocks_per_group);
 926
 927                 retval = io_channel_read_blk(fs->io, sb, -SUPERBLOCK_SIZE,
 928                                              buf);
 929                 if (retval)
 930                         continue;
 931                 backup_sb = (struct ext2_super_block *) buf;
 932 #ifdef WORDS_BIGENDIAN
 933                 ext2fs_swap_super(backup_sb);
 934 #endif
 935                 if ((backup_sb->s_magic != EXT2_SUPER_MAGIC) ||
 936                     (backup_sb->s_rev_level > EXT2_LIB_CURRENT_REV) ||
 937                     ((backup_sb->s_log_block_size + EXT2_MIN_BLOCK_LOG_SIZE) >
 938                      EXT2_MAX_BLOCK_LOG_SIZE) ||
 939                     (EXT2_INODE_SIZE(backup_sb) < EXT2_GOOD_OLD_INODE_SIZE))
 940                         continue;
 941
 942 #define SUPER_INCOMPAT_DIFFERENT(x)     \
 943         ((fs->super->x & ~FEATURE_INCOMPAT_IGNORE) !=   \
 944          (backup_sb->x & ~FEATURE_INCOMPAT_IGNORE))
 945 #define SUPER_RO_COMPAT_DIFFERENT(x)    \
 946         ((fs->super->x & ~FEATURE_RO_COMPAT_IGNORE) !=  \
 947          (backup_sb->x & ~FEATURE_RO_COMPAT_IGNORE))
 948 #define SUPER_DIFFERENT(x)              \
 949         (fs->super->x != backup_sb->x)
 950
 951                 if (SUPER_DIFFERENT(s_feature_compat) ||
 952                     SUPER_INCOMPAT_DIFFERENT(s_feature_incompat) ||
 953                     SUPER_RO_COMPAT_DIFFERENT(s_feature_ro_compat) ||
 954                     SUPER_DIFFERENT(s_blocks_count) ||
 955                     SUPER_DIFFERENT(s_inodes_count) ||
 956                     memcmp(fs->super->s_uuid, backup_sb->s_uuid,
 957                            sizeof(fs->super->s_uuid)))
 958                         ret = 1;
 959                 break;
 960         }
 961         return ret;
 962 }