e2fsck/journal.c

   1 /*
   2  * journal.c --- code for handling the "ext3" journal
   3  *
   4  * Copyright (C) 2000 Andreas Dilger
   5  * Copyright (C) 2000 Theodore Ts'o
   6  *
   7  * Parts of the code are based on fs/jfs/journal.c by Stephen C. Tweedie
   8  * Copyright (C) 1999 Red Hat Software
   9  *
  10  * This file may be redistributed under the terms of the
  11  * GNU General Public License version 2 or at your discretion
  12  * any later version.
  13  */
  14
  15 #include "config.h"
  16 #ifdef HAVE_SYS_MOUNT_H
  17 #include <sys/param.h>
  18 #include <sys/mount.h>
  19 #define MNT_FL (MS_MGC_VAL | MS_RDONLY)
  20 #endif
  21 #ifdef HAVE_SYS_STAT_H
  22 #include <sys/stat.h>
  23 #endif
  24
  25 #define E2FSCK_INCLUDE_INLINE_FUNCS
  26 #include "jfs_user.h"
  27 #include "problem.h"
  28 #include "uuid/uuid.h"
  29
  30 #ifdef CONFIG_JBD_DEBUG         /* Enabled by configure --enable-jfs-debug */
  31 static int bh_count = 0;
  32 #endif
  33
  34 /*
  35  * Define USE_INODE_IO to use the inode_io.c / fileio.c codepaths.
  36  * This creates a larger static binary, and a smaller binary using
  37  * shared libraries.  It's also probably slightly less CPU-efficient,
  38  * which is why it's not on by default.  But, it's a good way of
  39  * testing the functions in inode_io.c and fileio.c.
  40  */
  41 #undef USE_INODE_IO
  42
  43 /* Checksumming functions */
  44 static int e2fsck_journal_verify_csum_type(journal_t *j,
  45                                            journal_superblock_t *jsb)
  46 {
  47         if (!journal_has_csum_v2or3(j))
  48                 return 1;
  49
  50         return jsb->s_checksum_type == JBD2_CRC32C_CHKSUM;
  51 }
  52
  53 static __u32 e2fsck_journal_sb_csum(journal_superblock_t *jsb)
  54 {
  55         __u32 crc, old_crc;
  56
  57         old_crc = jsb->s_checksum;
  58         jsb->s_checksum = 0;
  59         crc = ext2fs_crc32c_le(~0, (unsigned char *)jsb,
  60                                sizeof(journal_superblock_t));
  61         jsb->s_checksum = old_crc;
  62
  63         return crc;
  64 }
  65
  66 static int e2fsck_journal_sb_csum_verify(journal_t *j,
  67                                          journal_superblock_t *jsb)
  68 {
  69         __u32 provided, calculated;
  70
  71         if (!journal_has_csum_v2or3(j))
  72                 return 1;
  73
  74         provided = ext2fs_be32_to_cpu(jsb->s_checksum);
  75         calculated = e2fsck_journal_sb_csum(jsb);
  76
  77         return provided == calculated;
  78 }
  79
  80 static errcode_t e2fsck_journal_sb_csum_set(journal_t *j,
  81                                             journal_superblock_t *jsb)
  82 {
  83         __u32 crc;
  84
  85         if (!journal_has_csum_v2or3(j))
  86                 return 0;
  87
  88         crc = e2fsck_journal_sb_csum(jsb);
  89         jsb->s_checksum = ext2fs_cpu_to_be32(crc);
  90         return 0;
  91 }
  92
  93 /* Kernel compatibility functions for handling the journal.  These allow us
  94  * to use the recovery.c file virtually unchanged from the kernel, so we
  95  * don't have to do much to keep kernel and user recovery in sync.
  96  */
  97 int journal_bmap(journal_t *journal, blk64_t block, unsigned long long *phys)
  98 {
  99 #ifdef USE_INODE_IO
 100         *phys = block;
 101         return 0;
 102 #else
 103         struct inode    *inode = journal->j_inode;
 104         errcode_t       retval;
 105         blk64_t         pblk;
 106
 107         if (!inode) {
 108                 *phys = block;
 109                 return 0;
 110         }
 111
 112         retval= ext2fs_bmap2(inode->i_ctx->fs, inode->i_ino,
 113                              &inode->i_ext2, NULL, 0, block, 0, &pblk);
 114         *phys = pblk;
 115         return (int) retval;
 116 #endif
 117 }
 118
 119 struct buffer_head *getblk(kdev_t kdev, blk64_t blocknr, int blocksize)
 120 {
 121         struct buffer_head *bh;
 122         int bufsize = sizeof(*bh) + kdev->k_ctx->fs->blocksize -
 123                 sizeof(bh->b_data);
 124
 125         bh = e2fsck_allocate_memory(kdev->k_ctx, bufsize, "block buffer");
 126         if (!bh)
 127                 return NULL;
 128
 129 #ifdef CONFIG_JBD_DEBUG
 130         if (journal_enable_debug >= 3)
 131                 bh_count++;
 132 #endif
 133         jfs_debug(4, "getblk for block %llu (%d bytes)(total %d)\n",
 134                   (unsigned long long) blocknr, blocksize, bh_count);
 135
 136         bh->b_ctx = kdev->k_ctx;
 137         if (kdev->k_dev == K_DEV_FS)
 138                 bh->b_io = kdev->k_ctx->fs->io;
 139         else
 140                 bh->b_io = kdev->k_ctx->journal_io;
 141         bh->b_size = blocksize;
 142         bh->b_blocknr = blocknr;
 143
 144         return bh;
 145 }
 146
 147 int sync_blockdev(kdev_t kdev)
 148 {
 149         io_channel      io;
 150
 151         if (kdev->k_dev == K_DEV_FS)
 152                 io = kdev->k_ctx->fs->io;
 153         else
 154                 io = kdev->k_ctx->journal_io;
 155
 156         return io_channel_flush(io) ? EIO : 0;
 157 }
 158
 159 void ll_rw_block(int rw, int nr, struct buffer_head *bhp[])
 160 {
 161         errcode_t retval;
 162         struct buffer_head *bh;
 163
 164         for (; nr > 0; --nr) {
 165                 bh = *bhp++;
 166                 if (rw == READ && !bh->b_uptodate) {
 167                         jfs_debug(3, "reading block %llu/%p\n",
 168                                   bh->b_blocknr, (void *) bh);
 169                         retval = io_channel_read_blk64(bh->b_io,
 170                                                      bh->b_blocknr,
 171                                                      1, bh->b_data);
 172                         if (retval) {
 173                                 com_err(bh->b_ctx->device_name, retval,
 174                                         "while reading block %llu\n",
 175                                         bh->b_blocknr);
 176                                 bh->b_err = (int) retval;
 177                                 continue;
 178                         }
 179                         bh->b_uptodate = 1;
 180                 } else if (rw == WRITE && bh->b_dirty) {
 181                         jfs_debug(3, "writing block %llu/%p\n",
 182                                   bh->b_blocknr,
 183                                   (void *) bh);
 184                         retval = io_channel_write_blk64(bh->b_io,
 185                                                       bh->b_blocknr,
 186                                                       1, bh->b_data);
 187                         if (retval) {
 188                                 com_err(bh->b_ctx->device_name, retval,
 189                                         "while writing block %llu\n",
 190                                         bh->b_blocknr);
 191                                 bh->b_err = (int) retval;
 192                                 continue;
 193                         }
 194                         bh->b_dirty = 0;
 195                         bh->b_uptodate = 1;
 196                 } else {
 197                         jfs_debug(3, "no-op %s for block %llu\n",
 198                                   rw == READ ? "read" : "write",
 199                                   bh->b_blocknr);
 200                 }
 201         }
 202 }
 203
 204 void mark_buffer_dirty(struct buffer_head *bh)
 205 {
 206         bh->b_dirty = 1;
 207 }
 208
 209 static void mark_buffer_clean(struct buffer_head * bh)
 210 {
 211         bh->b_dirty = 0;
 212 }
 213
 214 void brelse(struct buffer_head *bh)
 215 {
 216         if (bh->b_dirty)
 217                 ll_rw_block(WRITE, 1, &bh);
 218         jfs_debug(3, "freeing block %llu/%p (total %d)\n",
 219                   bh->b_blocknr, (void *) bh, --bh_count);
 220         ext2fs_free_mem(&bh);
 221 }
 222
 223 int buffer_uptodate(struct buffer_head *bh)
 224 {
 225         return bh->b_uptodate;
 226 }
 227
 228 void mark_buffer_uptodate(struct buffer_head *bh, int val)
 229 {
 230         bh->b_uptodate = val;
 231 }
 232
 233 void wait_on_buffer(struct buffer_head *bh)
 234 {
 235         if (!bh->b_uptodate)
 236                 ll_rw_block(READ, 1, &bh);
 237 }
 238
 239
 240 static void e2fsck_clear_recover(e2fsck_t ctx, int error)
 241 {
 242         ext2fs_clear_feature_journal_needs_recovery(ctx->fs->super);
 243
 244         /* if we had an error doing journal recovery, we need a full fsck */
 245         if (error)
 246                 ctx->fs->super->s_state &= ~EXT2_VALID_FS;
 247         ext2fs_mark_super_dirty(ctx->fs);
 248 }
 249
 250 /*
 251  * This is a helper function to check the validity of the journal.
 252  */
 253 struct process_block_struct {
 254         e2_blkcnt_t     last_block;
 255 };
 256
 257 static int process_journal_block(ext2_filsys fs,
 258                                  blk64_t        *block_nr,
 259                                  e2_blkcnt_t blockcnt,
 260                                  blk64_t ref_block EXT2FS_ATTR((unused)),
 261                                  int ref_offset EXT2FS_ATTR((unused)),
 262                                  void *priv_data)
 263 {
 264         struct process_block_struct *p;
 265         blk64_t blk = *block_nr;
 266
 267         p = (struct process_block_struct *) priv_data;
 268
 269         if (!blk || blk < fs->super->s_first_data_block ||
 270             blk >= ext2fs_blocks_count(fs->super))
 271                 return BLOCK_ABORT;
 272
 273         if (blockcnt >= 0)
 274                 p->last_block = blockcnt;
 275         return 0;
 276 }
 277
 278 static errcode_t e2fsck_get_journal(e2fsck_t ctx, journal_t **ret_journal)
 279 {
 280         struct process_block_struct pb;
 281         struct ext2_super_block *sb = ctx->fs->super;
 282         struct ext2_super_block jsuper;
 283         struct problem_context  pctx;
 284         struct buffer_head      *bh;
 285         struct inode            *j_inode = NULL;
 286         struct kdev_s           *dev_fs = NULL, *dev_journal;
 287         const char              *journal_name = 0;
 288         journal_t               *journal = NULL;
 289         errcode_t               retval = 0;
 290         io_manager              io_ptr = 0;
 291         unsigned long long      start = 0;
 292         int                     ext_journal = 0;
 293         int                     tried_backup_jnl = 0;
 294
 295         clear_problem_context(&pctx);
 296
 297         journal = e2fsck_allocate_memory(ctx, sizeof(journal_t), "journal");
 298         if (!journal) {
 299                 return EXT2_ET_NO_MEMORY;
 300         }
 301
 302         dev_fs = e2fsck_allocate_memory(ctx, 2*sizeof(struct kdev_s), "kdev");
 303         if (!dev_fs) {
 304                 retval = EXT2_ET_NO_MEMORY;
 305                 goto errout;
 306         }
 307         dev_journal = dev_fs+1;
 308
 309         dev_fs->k_ctx = dev_journal->k_ctx = ctx;
 310         dev_fs->k_dev = K_DEV_FS;
 311         dev_journal->k_dev = K_DEV_JOURNAL;
 312
 313         journal->j_dev = dev_journal;
 314         journal->j_fs_dev = dev_fs;
 315         journal->j_inode = NULL;
 316         journal->j_blocksize = ctx->fs->blocksize;
 317
 318         if (uuid_is_null(sb->s_journal_uuid)) {
 319                 if (!sb->s_journal_inum) {
 320                         retval = EXT2_ET_BAD_INODE_NUM;
 321                         goto errout;
 322                 }
 323                 j_inode = e2fsck_allocate_memory(ctx, sizeof(*j_inode),
 324                                                  "journal inode");
 325                 if (!j_inode) {
 326                         retval = EXT2_ET_NO_MEMORY;
 327                         goto errout;
 328                 }
 329
 330                 j_inode->i_ctx = ctx;
 331                 j_inode->i_ino = sb->s_journal_inum;
 332
 333                 if ((retval = ext2fs_read_inode(ctx->fs,
 334                                                 sb->s_journal_inum,
 335                                                 &j_inode->i_ext2))) {
 336                 try_backup_journal:
 337                         if (sb->s_jnl_backup_type != EXT3_JNL_BACKUP_BLOCKS ||
 338                             tried_backup_jnl)
 339                                 goto errout;
 340                         memset(&j_inode->i_ext2, 0, sizeof(struct ext2_inode));
 341                         memcpy(&j_inode->i_ext2.i_block[0], sb->s_jnl_blocks,
 342                                EXT2_N_BLOCKS*4);
 343                         j_inode->i_ext2.i_size_high = sb->s_jnl_blocks[15];
 344                         j_inode->i_ext2.i_size = sb->s_jnl_blocks[16];
 345                         j_inode->i_ext2.i_links_count = 1;
 346                         j_inode->i_ext2.i_mode = LINUX_S_IFREG | 0600;
 347                         e2fsck_use_inode_shortcuts(ctx, 1);
 348                         ctx->stashed_ino = j_inode->i_ino;
 349                         ctx->stashed_inode = &j_inode->i_ext2;
 350                         tried_backup_jnl++;
 351                 }
 352                 if (!j_inode->i_ext2.i_links_count ||
 353                     !LINUX_S_ISREG(j_inode->i_ext2.i_mode)) {
 354                         retval = EXT2_ET_NO_JOURNAL;
 355                         goto try_backup_journal;
 356                 }
 357                 if (EXT2_I_SIZE(&j_inode->i_ext2) / journal->j_blocksize <
 358                     JFS_MIN_JOURNAL_BLOCKS) {
 359                         retval = EXT2_ET_JOURNAL_TOO_SMALL;
 360                         goto try_backup_journal;
 361                 }
 362                 pb.last_block = -1;
 363                 retval = ext2fs_block_iterate3(ctx->fs, j_inode->i_ino,
 364                                                BLOCK_FLAG_HOLE, 0,
 365                                                process_journal_block, &pb);
 366                 if ((pb.last_block + 1) * ctx->fs->blocksize <
 367                     (int) EXT2_I_SIZE(&j_inode->i_ext2)) {
 368                         retval = EXT2_ET_JOURNAL_TOO_SMALL;
 369                         goto try_backup_journal;
 370                 }
 371                 if (tried_backup_jnl && !(ctx->options & E2F_OPT_READONLY)) {
 372                         retval = ext2fs_write_inode(ctx->fs, sb->s_journal_inum,
 373                                                     &j_inode->i_ext2);
 374                         if (retval)
 375                                 goto errout;
 376                 }
 377
 378                 journal->j_maxlen = EXT2_I_SIZE(&j_inode->i_ext2) /
 379                         journal->j_blocksize;
 380
 381 #ifdef USE_INODE_IO
 382                 retval = ext2fs_inode_io_intern2(ctx->fs, sb->s_journal_inum,
 383                                                  &j_inode->i_ext2,
 384                                                  &journal_name);
 385                 if (retval)
 386                         goto errout;
 387
 388                 io_ptr = inode_io_manager;
 389 #else
 390                 journal->j_inode = j_inode;
 391                 ctx->journal_io = ctx->fs->io;
 392                 if ((retval = (errcode_t) journal_bmap(journal, 0, &start)) != 0)
 393                         goto errout;
 394 #endif
 395         } else {
 396                 ext_journal = 1;
 397                 if (!ctx->journal_name) {
 398                         char uuid[37];
 399
 400                         uuid_unparse(sb->s_journal_uuid, uuid);
 401                         ctx->journal_name = blkid_get_devname(ctx->blkid,
 402                                                               "UUID", uuid);
 403                         if (!ctx->journal_name)
 404                                 ctx->journal_name = blkid_devno_to_devname(sb->s_journal_dev);
 405                 }
 406                 journal_name = ctx->journal_name;
 407
 408                 if (!journal_name) {
 409                         fix_problem(ctx, PR_0_CANT_FIND_JOURNAL, &pctx);
 410                         retval = EXT2_ET_LOAD_EXT_JOURNAL;
 411                         goto errout;
 412                 }
 413
 414                 jfs_debug(1, "Using journal file %s\n", journal_name);
 415                 io_ptr = unix_io_manager;
 416         }
 417
 418 #if 0
 419         test_io_backing_manager = io_ptr;
 420         io_ptr = test_io_manager;
 421 #endif
 422 #ifndef USE_INODE_IO
 423         if (ext_journal)
 424 #endif
 425         {
 426                 int flags = IO_FLAG_RW;
 427                 if (!(ctx->mount_flags & EXT2_MF_ISROOT &&
 428                       ctx->mount_flags & EXT2_MF_READONLY))
 429                         flags |= IO_FLAG_EXCLUSIVE;
 430                 if ((ctx->mount_flags & EXT2_MF_READONLY) &&
 431                     (ctx->options & E2F_OPT_FORCE))
 432                         flags &= ~IO_FLAG_EXCLUSIVE;
 433
 434
 435                 retval = io_ptr->open(journal_name, flags,
 436                                       &ctx->journal_io);
 437         }
 438         if (retval)
 439                 goto errout;
 440
 441         io_channel_set_blksize(ctx->journal_io, ctx->fs->blocksize);
 442
 443         if (ext_journal) {
 444                 blk64_t maxlen;
 445
 446                 start = ext2fs_journal_sb_start(ctx->fs->blocksize) - 1;
 447                 bh = getblk(dev_journal, start, ctx->fs->blocksize);
 448                 if (!bh) {
 449                         retval = EXT2_ET_NO_MEMORY;
 450                         goto errout;
 451                 }
 452                 ll_rw_block(READ, 1, &bh);
 453                 if ((retval = bh->b_err) != 0) {
 454                         brelse(bh);
 455                         goto errout;
 456                 }
 457                 memcpy(&jsuper, start ? bh->b_data :  bh->b_data + SUPERBLOCK_OFFSET,
 458                        sizeof(jsuper));
 459 #ifdef WORDS_BIGENDIAN
 460                 if (jsuper.s_magic == ext2fs_swab16(EXT2_SUPER_MAGIC))
 461                         ext2fs_swap_super(&jsuper);
 462 #endif
 463                 if (jsuper.s_magic != EXT2_SUPER_MAGIC ||
 464                     !ext2fs_has_feature_journal_dev(&jsuper)) {
 465                         fix_problem(ctx, PR_0_EXT_JOURNAL_BAD_SUPER, &pctx);
 466                         retval = EXT2_ET_LOAD_EXT_JOURNAL;
 467                         brelse(bh);
 468                         goto errout;
 469                 }
 470                 /* Make sure the journal UUID is correct */
 471                 if (memcmp(jsuper.s_uuid, ctx->fs->super->s_journal_uuid,
 472                            sizeof(jsuper.s_uuid))) {
 473                         fix_problem(ctx, PR_0_JOURNAL_BAD_UUID, &pctx);
 474                         retval = EXT2_ET_LOAD_EXT_JOURNAL;
 475                         brelse(bh);
 476                         goto errout;
 477                 }
 478
 479                 /* Check the superblock checksum */
 480                 if (ext2fs_has_feature_metadata_csum(&jsuper)) {
 481                         struct struct_ext2_filsys fsx;
 482                         struct ext2_super_block superx;
 483                         void *p;
 484
 485                         p = start ? bh->b_data : bh->b_data + SUPERBLOCK_OFFSET;
 486                         memcpy(&fsx, ctx->fs, sizeof(fsx));
 487                         memcpy(&superx, ctx->fs->super, sizeof(superx));
 488                         fsx.super = &superx;
 489                         ext2fs_set_feature_metadata_csum(fsx.super);
 490                         if (!ext2fs_superblock_csum_verify(&fsx, p) &&
 491                             fix_problem(ctx, PR_0_EXT_JOURNAL_SUPER_CSUM_INVALID,
 492                                         &pctx)) {
 493                                 ext2fs_superblock_csum_set(&fsx, p);
 494                                 mark_buffer_dirty(bh);
 495                         }
 496                 }
 497                 brelse(bh);
 498
 499                 maxlen = ext2fs_blocks_count(&jsuper);
 500                 journal->j_maxlen = (maxlen < 1ULL << 32) ? maxlen : (1ULL << 32) - 1;
 501                 start++;
 502         }
 503
 504         if (!(bh = getblk(dev_journal, start, journal->j_blocksize))) {
 505                 retval = EXT2_ET_NO_MEMORY;
 506                 goto errout;
 507         }
 508
 509         journal->j_sb_buffer = bh;
 510         journal->j_superblock = (journal_superblock_t *)bh->b_data;
 511
 512 #ifdef USE_INODE_IO
 513         if (j_inode)
 514                 ext2fs_free_mem(&j_inode);
 515 #endif
 516
 517         *ret_journal = journal;
 518         e2fsck_use_inode_shortcuts(ctx, 0);
 519         return 0;
 520
 521 errout:
 522         e2fsck_use_inode_shortcuts(ctx, 0);
 523         if (dev_fs)
 524                 ext2fs_free_mem(&dev_fs);
 525         if (j_inode)
 526                 ext2fs_free_mem(&j_inode);
 527         if (journal)
 528                 ext2fs_free_mem(&journal);
 529         return retval;
 530 }
 531
 532 static errcode_t e2fsck_journal_fix_bad_inode(e2fsck_t ctx,
 533                                               struct problem_context *pctx)
 534 {
 535         struct ext2_super_block *sb = ctx->fs->super;
 536         int recover = ext2fs_has_feature_journal_needs_recovery(ctx->fs->super);
 537         int has_journal = ext2fs_has_feature_journal(ctx->fs->super);
 538
 539         if (has_journal || sb->s_journal_inum) {
 540                 /* The journal inode is bogus, remove and force full fsck */
 541                 pctx->ino = sb->s_journal_inum;
 542                 if (fix_problem(ctx, PR_0_JOURNAL_BAD_INODE, pctx)) {
 543                         if (has_journal && sb->s_journal_inum)
 544                                 printf("*** journal has been deleted ***\n\n");
 545                         ext2fs_clear_feature_journal(sb);
 546                         sb->s_journal_inum = 0;
 547                         memset(sb->s_jnl_blocks, 0, sizeof(sb->s_jnl_blocks));
 548                         ctx->flags |= E2F_FLAG_JOURNAL_INODE;
 549                         ctx->fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
 550                         e2fsck_clear_recover(ctx, 1);
 551                         return 0;
 552                 }
 553                 return EXT2_ET_CORRUPT_JOURNAL_SB;
 554         } else if (recover) {
 555                 if (fix_problem(ctx, PR_0_JOURNAL_RECOVER_SET, pctx)) {
 556                         e2fsck_clear_recover(ctx, 1);
 557                         return 0;
 558                 }
 559                 return EXT2_ET_UNSUPP_FEATURE;
 560         }
 561         return 0;
 562 }
 563
 564 #define V1_SB_SIZE      0x0024
 565 static void clear_v2_journal_fields(journal_t *journal)
 566 {
 567         e2fsck_t ctx = journal->j_dev->k_ctx;
 568         struct problem_context pctx;
 569
 570         clear_problem_context(&pctx);
 571
 572         if (!fix_problem(ctx, PR_0_CLEAR_V2_JOURNAL, &pctx))
 573                 return;
 574
 575         ctx->flags |= E2F_FLAG_PROBLEMS_FIXED;
 576         memset(((char *) journal->j_superblock) + V1_SB_SIZE, 0,
 577                ctx->fs->blocksize-V1_SB_SIZE);
 578         mark_buffer_dirty(journal->j_sb_buffer);
 579 }
 580
 581
 582 static errcode_t e2fsck_journal_load(journal_t *journal)
 583 {
 584         e2fsck_t ctx = journal->j_dev->k_ctx;
 585         journal_superblock_t *jsb;
 586         struct buffer_head *jbh = journal->j_sb_buffer;
 587         struct problem_context pctx;
 588
 589         clear_problem_context(&pctx);
 590
 591         ll_rw_block(READ, 1, &jbh);
 592         if (jbh->b_err) {
 593                 com_err(ctx->device_name, jbh->b_err, "%s",
 594                         _("reading journal superblock\n"));
 595                 return jbh->b_err;
 596         }
 597
 598         jsb = journal->j_superblock;
 599         /* If we don't even have JFS_MAGIC, we probably have a wrong inode */
 600         if (jsb->s_header.h_magic != htonl(JFS_MAGIC_NUMBER))
 601                 return e2fsck_journal_fix_bad_inode(ctx, &pctx);
 602
 603         switch (ntohl(jsb->s_header.h_blocktype)) {
 604         case JFS_SUPERBLOCK_V1:
 605                 journal->j_format_version = 1;
 606                 if (jsb->s_feature_compat ||
 607                     jsb->s_feature_incompat ||
 608                     jsb->s_feature_ro_compat ||
 609                     jsb->s_nr_users)
 610                         clear_v2_journal_fields(journal);
 611                 break;
 612
 613         case JFS_SUPERBLOCK_V2:
 614                 journal->j_format_version = 2;
 615                 if (ntohl(jsb->s_nr_users) > 1 &&
 616                     uuid_is_null(ctx->fs->super->s_journal_uuid))
 617                         clear_v2_journal_fields(journal);
 618                 if (ntohl(jsb->s_nr_users) > 1) {
 619                         fix_problem(ctx, PR_0_JOURNAL_UNSUPP_MULTIFS, &pctx);
 620                         return EXT2_ET_JOURNAL_UNSUPP_VERSION;
 621                 }
 622                 break;
 623
 624         /*
 625          * These should never appear in a journal super block, so if
 626          * they do, the journal is badly corrupted.
 627          */
 628         case JFS_DESCRIPTOR_BLOCK:
 629         case JFS_COMMIT_BLOCK:
 630         case JFS_REVOKE_BLOCK:
 631                 return EXT2_ET_CORRUPT_JOURNAL_SB;
 632
 633         /* If we don't understand the superblock major type, but there
 634          * is a magic number, then it is likely to be a new format we
 635          * just don't understand, so leave it alone. */
 636         default:
 637                 return EXT2_ET_JOURNAL_UNSUPP_VERSION;
 638         }
 639
 640         if (JFS_HAS_INCOMPAT_FEATURE(journal, ~JFS_KNOWN_INCOMPAT_FEATURES))
 641                 return EXT2_ET_UNSUPP_FEATURE;
 642
 643         if (JFS_HAS_RO_COMPAT_FEATURE(journal, ~JFS_KNOWN_ROCOMPAT_FEATURES))
 644                 return EXT2_ET_RO_UNSUPP_FEATURE;
 645
 646         /* Checksum v1-3 are mutually exclusive features. */
 647         if (jfs_has_feature_csum2(journal) && jfs_has_feature_csum3(journal))
 648                 return EXT2_ET_CORRUPT_JOURNAL_SB;
 649
 650         if (journal_has_csum_v2or3(journal) &&
 651             jfs_has_feature_checksum(journal))
 652                 return EXT2_ET_CORRUPT_JOURNAL_SB;
 653
 654         if (!e2fsck_journal_verify_csum_type(journal, jsb) ||
 655             !e2fsck_journal_sb_csum_verify(journal, jsb))
 656                 return EXT2_ET_CORRUPT_JOURNAL_SB;
 657
 658         if (journal_has_csum_v2or3(journal))
 659                 journal->j_csum_seed = jbd2_chksum(journal, ~0, jsb->s_uuid,
 660                                                    sizeof(jsb->s_uuid));
 661
 662         /* We have now checked whether we know enough about the journal
 663          * format to be able to proceed safely, so any other checks that
 664          * fail we should attempt to recover from. */
 665         if (jsb->s_blocksize != htonl(journal->j_blocksize)) {
 666                 com_err(ctx->program_name, EXT2_ET_CORRUPT_JOURNAL_SB,
 667                         _("%s: no valid journal superblock found\n"),
 668                         ctx->device_name);
 669                 return EXT2_ET_CORRUPT_JOURNAL_SB;
 670         }
 671
 672         if (ntohl(jsb->s_maxlen) < journal->j_maxlen)
 673                 journal->j_maxlen = ntohl(jsb->s_maxlen);
 674         else if (ntohl(jsb->s_maxlen) > journal->j_maxlen) {
 675                 com_err(ctx->program_name, EXT2_ET_CORRUPT_JOURNAL_SB,
 676                         _("%s: journal too short\n"),
 677                         ctx->device_name);
 678                 return EXT2_ET_CORRUPT_JOURNAL_SB;
 679         }
 680
 681         journal->j_tail_sequence = ntohl(jsb->s_sequence);
 682         journal->j_transaction_sequence = journal->j_tail_sequence;
 683         journal->j_tail = ntohl(jsb->s_start);
 684         journal->j_first = ntohl(jsb->s_first);
 685         journal->j_last = ntohl(jsb->s_maxlen);
 686
 687         return 0;
 688 }
 689
 690 static void e2fsck_journal_reset_super(e2fsck_t ctx, journal_superblock_t *jsb,
 691                                        journal_t *journal)
 692 {
 693         char *p;
 694         union {
 695                 uuid_t uuid;
 696                 __u32 val[4];
 697         } u;
 698         __u32 new_seq = 0;
 699         int i;
 700
 701         /* Leave a valid existing V1 superblock signature alone.
 702          * Anything unrecognisable we overwrite with a new V2
 703          * signature. */
 704
 705         if (jsb->s_header.h_magic != htonl(JFS_MAGIC_NUMBER) ||
 706             jsb->s_header.h_blocktype != htonl(JFS_SUPERBLOCK_V1)) {
 707                 jsb->s_header.h_magic = htonl(JFS_MAGIC_NUMBER);
 708                 jsb->s_header.h_blocktype = htonl(JFS_SUPERBLOCK_V2);
 709         }
 710
 711         /* Zero out everything else beyond the superblock header */
 712
 713         p = ((char *) jsb) + sizeof(journal_header_t);
 714         memset (p, 0, ctx->fs->blocksize-sizeof(journal_header_t));
 715
 716         jsb->s_blocksize = htonl(ctx->fs->blocksize);
 717         jsb->s_maxlen = htonl(journal->j_maxlen);
 718         jsb->s_first = htonl(1);
 719
 720         /* Initialize the journal sequence number so that there is "no"
 721          * chance we will find old "valid" transactions in the journal.
 722          * This avoids the need to zero the whole journal (slow to do,
 723          * and risky when we are just recovering the filesystem).
 724          */
 725         uuid_generate(u.uuid);
 726         for (i = 0; i < 4; i ++)
 727                 new_seq ^= u.val[i];
 728         jsb->s_sequence = htonl(new_seq);
 729         e2fsck_journal_sb_csum_set(journal, jsb);
 730
 731         mark_buffer_dirty(journal->j_sb_buffer);
 732         ll_rw_block(WRITE, 1, &journal->j_sb_buffer);
 733 }
 734
 735 static errcode_t e2fsck_journal_fix_corrupt_super(e2fsck_t ctx,
 736                                                   journal_t *journal,
 737                                                   struct problem_context *pctx)
 738 {
 739         struct ext2_super_block *sb = ctx->fs->super;
 740         int recover = ext2fs_has_feature_journal_needs_recovery(ctx->fs->super);
 741
 742         if (ext2fs_has_feature_journal(sb)) {
 743                 if (fix_problem(ctx, PR_0_JOURNAL_BAD_SUPER, pctx)) {
 744                         e2fsck_journal_reset_super(ctx, journal->j_superblock,
 745                                                    journal);
 746                         journal->j_transaction_sequence = 1;
 747                         e2fsck_clear_recover(ctx, recover);
 748                         return 0;
 749                 }
 750                 return EXT2_ET_CORRUPT_JOURNAL_SB;
 751         } else if (e2fsck_journal_fix_bad_inode(ctx, pctx))
 752                 return EXT2_ET_CORRUPT_JOURNAL_SB;
 753
 754         return 0;
 755 }
 756
 757 static void e2fsck_journal_release(e2fsck_t ctx, journal_t *journal,
 758                                    int reset, int drop)
 759 {
 760         journal_superblock_t *jsb;
 761
 762         if (drop)
 763                 mark_buffer_clean(journal->j_sb_buffer);
 764         else if (!(ctx->options & E2F_OPT_READONLY)) {
 765                 jsb = journal->j_superblock;
 766                 jsb->s_sequence = htonl(journal->j_tail_sequence);
 767                 if (reset)
 768                         jsb->s_start = 0; /* this marks the journal as empty */
 769                 e2fsck_journal_sb_csum_set(journal, jsb);
 770                 mark_buffer_dirty(journal->j_sb_buffer);
 771         }
 772         brelse(journal->j_sb_buffer);
 773
 774         if (ctx->journal_io) {
 775                 if (ctx->fs && ctx->fs->io != ctx->journal_io)
 776                         io_channel_close(ctx->journal_io);
 777                 ctx->journal_io = 0;
 778         }
 779
 780 #ifndef USE_INODE_IO
 781         if (journal->j_inode)
 782                 ext2fs_free_mem(&journal->j_inode);
 783 #endif
 784         if (journal->j_fs_dev)
 785                 ext2fs_free_mem(&journal->j_fs_dev);
 786         ext2fs_free_mem(&journal);
 787 }
 788
 789 /*
 790  * This function makes sure that the superblock fields regarding the
 791  * journal are consistent.
 792  */
 793 errcode_t e2fsck_check_ext3_journal(e2fsck_t ctx)
 794 {
 795         struct ext2_super_block *sb = ctx->fs->super;
 796         journal_t *journal;
 797         int recover = ext2fs_has_feature_journal_needs_recovery(ctx->fs->super);
 798         struct problem_context pctx;
 799         problem_t problem;
 800         int reset = 0, force_fsck = 0;
 801         errcode_t retval;
 802
 803         /* If we don't have any journal features, don't do anything more */
 804         if (!ext2fs_has_feature_journal(sb) &&
 805             !recover && sb->s_journal_inum == 0 && sb->s_journal_dev == 0 &&
 806             uuid_is_null(sb->s_journal_uuid))
 807                 return 0;
 808
 809         clear_problem_context(&pctx);
 810         pctx.num = sb->s_journal_inum;
 811
 812         retval = e2fsck_get_journal(ctx, &journal);
 813         if (retval) {
 814                 if ((retval == EXT2_ET_BAD_INODE_NUM) ||
 815                     (retval == EXT2_ET_BAD_BLOCK_NUM) ||
 816                     (retval == EXT2_ET_JOURNAL_TOO_SMALL) ||
 817                     (retval == EXT2_ET_NO_JOURNAL))
 818                         return e2fsck_journal_fix_bad_inode(ctx, &pctx);
 819                 return retval;
 820         }
 821
 822         retval = e2fsck_journal_load(journal);
 823         if (retval) {
 824                 if ((retval == EXT2_ET_CORRUPT_JOURNAL_SB) ||
 825                     ((retval == EXT2_ET_UNSUPP_FEATURE) &&
 826                     (!fix_problem(ctx, PR_0_JOURNAL_UNSUPP_INCOMPAT,
 827                                   &pctx))) ||
 828                     ((retval == EXT2_ET_RO_UNSUPP_FEATURE) &&
 829                     (!fix_problem(ctx, PR_0_JOURNAL_UNSUPP_ROCOMPAT,
 830                                   &pctx))) ||
 831                     ((retval == EXT2_ET_JOURNAL_UNSUPP_VERSION) &&
 832                     (!fix_problem(ctx, PR_0_JOURNAL_UNSUPP_VERSION, &pctx))))
 833                         retval = e2fsck_journal_fix_corrupt_super(ctx, journal,
 834                                                                   &pctx);
 835                 e2fsck_journal_release(ctx, journal, 0, 1);
 836                 return retval;
 837         }
 838
 839         /*
 840          * We want to make the flags consistent here.  We will not leave with
 841          * needs_recovery set but has_journal clear.  We can't get in a loop
 842          * with -y, -n, or -p, only if a user isn't making up their mind.
 843          */
 844 no_has_journal:
 845         if (!ext2fs_has_feature_journal(sb)) {
 846                 recover = ext2fs_has_feature_journal_needs_recovery(sb);
 847                 if (fix_problem(ctx, PR_0_JOURNAL_HAS_JOURNAL, &pctx)) {
 848                         if (recover &&
 849                             !fix_problem(ctx, PR_0_JOURNAL_RECOVER_SET, &pctx))
 850                                 goto no_has_journal;
 851                         /*
 852                          * Need a full fsck if we are releasing a
 853                          * journal stored on a reserved inode.
 854                          */
 855                         force_fsck = recover ||
 856                                 (sb->s_journal_inum < EXT2_FIRST_INODE(sb));
 857                         /* Clear all of the journal fields */
 858                         sb->s_journal_inum = 0;
 859                         sb->s_journal_dev = 0;
 860                         memset(sb->s_journal_uuid, 0,
 861                                sizeof(sb->s_journal_uuid));
 862                         e2fsck_clear_recover(ctx, force_fsck);
 863                 } else if (!(ctx->options & E2F_OPT_READONLY)) {
 864                         ext2fs_set_feature_journal(sb);
 865                         ctx->fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
 866                         ext2fs_mark_super_dirty(ctx->fs);
 867                 }
 868         }
 869
 870         if (ext2fs_has_feature_journal(sb) &&
 871             !ext2fs_has_feature_journal_needs_recovery(sb) &&
 872             journal->j_superblock->s_start != 0) {
 873                 /* Print status information */
 874                 fix_problem(ctx, PR_0_JOURNAL_RECOVERY_CLEAR, &pctx);
 875                 if (ctx->superblock)
 876                         problem = PR_0_JOURNAL_RUN_DEFAULT;
 877                 else
 878                         problem = PR_0_JOURNAL_RUN;
 879                 if (fix_problem(ctx, problem, &pctx)) {
 880                         ctx->options |= E2F_OPT_FORCE;
 881                         ext2fs_set_feature_journal_needs_recovery(sb);
 882                         ext2fs_mark_super_dirty(ctx->fs);
 883                 } else if (fix_problem(ctx,
 884                                        PR_0_JOURNAL_RESET_JOURNAL, &pctx)) {
 885                         reset = 1;
 886                         sb->s_state &= ~EXT2_VALID_FS;
 887                         ext2fs_mark_super_dirty(ctx->fs);
 888                 }
 889                 /*
 890                  * If the user answers no to the above question, we
 891                  * ignore the fact that journal apparently has data;
 892                  * accidentally replaying over valid data would be far
 893                  * worse than skipping a questionable recovery.
 894                  *
 895                  * XXX should we abort with a fatal error here?  What
 896                  * will the ext3 kernel code do if a filesystem with
 897                  * !NEEDS_RECOVERY but with a non-zero
 898                  * journal->j_superblock->s_start is mounted?
 899                  */
 900         }
 901
 902         /*
 903          * If we don't need to do replay the journal, check to see if
 904          * the journal's errno is set; if so, we need to mark the file
 905          * system as being corrupt and clear the journal's s_errno.
 906          */
 907         if (!ext2fs_has_feature_journal_needs_recovery(sb) &&
 908             journal->j_superblock->s_errno) {
 909                 ctx->fs->super->s_state |= EXT2_ERROR_FS;
 910                 ext2fs_mark_super_dirty(ctx->fs);
 911                 journal->j_superblock->s_errno = 0;
 912                 e2fsck_journal_sb_csum_set(journal, journal->j_superblock);
 913                 mark_buffer_dirty(journal->j_sb_buffer);
 914         }
 915
 916         e2fsck_journal_release(ctx, journal, reset, 0);
 917         return retval;
 918 }
 919
 920 static errcode_t recover_ext3_journal(e2fsck_t ctx)
 921 {
 922         struct problem_context  pctx;
 923         journal_t *journal;
 924         errcode_t retval;
 925
 926         clear_problem_context(&pctx);
 927
 928         journal_init_revoke_caches();
 929         retval = e2fsck_get_journal(ctx, &journal);
 930         if (retval)
 931                 return retval;
 932
 933         retval = e2fsck_journal_load(journal);
 934         if (retval)
 935                 goto errout;
 936
 937         retval = journal_init_revoke(journal, 1024);
 938         if (retval)
 939                 goto errout;
 940
 941         retval = -journal_recover(journal);
 942         if (retval)
 943                 goto errout;
 944
 945         if (journal->j_failed_commit) {
 946                 pctx.ino = journal->j_failed_commit;
 947                 fix_problem(ctx, PR_0_JNL_TXN_CORRUPT, &pctx);
 948                 journal->j_superblock->s_errno = -EINVAL;
 949                 mark_buffer_dirty(journal->j_sb_buffer);
 950         }
 951
 952         journal->j_tail_sequence = journal->j_transaction_sequence;
 953
 954 errout:
 955         journal_destroy_revoke(journal);
 956         journal_destroy_revoke_caches();
 957         e2fsck_journal_release(ctx, journal, 1, 0);
 958         return retval;
 959 }
 960
 961 errcode_t e2fsck_run_ext3_journal(e2fsck_t ctx)
 962 {
 963         io_manager io_ptr = ctx->fs->io->manager;
 964         int blocksize = ctx->fs->blocksize;
 965         errcode_t       retval, recover_retval;
 966         io_stats        stats = 0;
 967         unsigned long long kbytes_written = 0;
 968
 969         printf(_("%s: recovering journal\n"), ctx->device_name);
 970         if (ctx->options & E2F_OPT_READONLY) {
 971                 printf(_("%s: won't do journal recovery while read-only\n"),
 972                        ctx->device_name);
 973                 return EXT2_ET_FILE_RO;
 974         }
 975
 976         if (ctx->fs->flags & EXT2_FLAG_DIRTY)
 977                 ext2fs_flush(ctx->fs);  /* Force out any modifications */
 978
 979         recover_retval = recover_ext3_journal(ctx);
 980
 981         /*
 982          * Reload the filesystem context to get up-to-date data from disk
 983          * because journal recovery will change the filesystem under us.
 984          */
 985         if (ctx->fs->super->s_kbytes_written &&
 986             ctx->fs->io->manager->get_stats)
 987                 ctx->fs->io->manager->get_stats(ctx->fs->io, &stats);
 988         if (stats && stats->bytes_written)
 989                 kbytes_written = stats->bytes_written >> 10;
 990
 991         ext2fs_mmp_stop(ctx->fs);
 992         ext2fs_free(ctx->fs);
 993         retval = ext2fs_open(ctx->filesystem_name, ctx->openfs_flags,
 994                              ctx->superblock, blocksize, io_ptr,
 995                              &ctx->fs);
 996         if (retval) {
 997                 com_err(ctx->program_name, retval,
 998                         _("while trying to re-open %s"),
 999                         ctx->device_name);
1000                 fatal_error(ctx, 0);
1001         }
1002         ctx->fs->priv_data = ctx;
1003         ctx->fs->now = ctx->now;
1004         ctx->fs->flags |= EXT2_FLAG_MASTER_SB_ONLY;
1005         ctx->fs->super->s_kbytes_written += kbytes_written;
1006
1007         /* Set the superblock flags */
1008         e2fsck_clear_recover(ctx, recover_retval != 0);
1009
1010         /*
1011          * Do one last sanity check, and propagate journal->s_errno to
1012          * the EXT2_ERROR_FS flag in the fs superblock if needed.
1013          */
1014         retval = e2fsck_check_ext3_journal(ctx);
1015         return retval ? retval : recover_retval;
1016 }
1017
1018 /*
1019  * This function will move the journal inode from a visible file in
1020  * the filesystem directory hierarchy to the reserved inode if necessary.
1021  */
1022 static const char * const journal_names[] = {
1023         ".journal", "journal", ".journal.dat", "journal.dat", 0 };
1024
1025 void e2fsck_move_ext3_journal(e2fsck_t ctx)
1026 {
1027         struct ext2_super_block *sb = ctx->fs->super;
1028         struct problem_context  pctx;
1029         struct ext2_inode       inode;
1030         ext2_filsys             fs = ctx->fs;
1031         ext2_ino_t              ino;
1032         errcode_t               retval;
1033         const char * const *    cpp;
1034         dgrp_t                  group;
1035         int                     mount_flags;
1036
1037         clear_problem_context(&pctx);
1038
1039         /*
1040          * If the filesystem is opened read-only, or there is no
1041          * journal, then do nothing.
1042          */
1043         if ((ctx->options & E2F_OPT_READONLY) ||
1044             (sb->s_journal_inum == 0) ||
1045             !ext2fs_has_feature_journal(sb))
1046                 return;
1047
1048         /*
1049          * Read in the journal inode
1050          */
1051         if (ext2fs_read_inode(fs, sb->s_journal_inum, &inode) != 0)
1052                 return;
1053
1054         /*
1055          * If it's necessary to backup the journal inode, do so.
1056          */
1057         if ((sb->s_jnl_backup_type == 0) ||
1058             ((sb->s_jnl_backup_type == EXT3_JNL_BACKUP_BLOCKS) &&
1059              memcmp(inode.i_block, sb->s_jnl_blocks, EXT2_N_BLOCKS*4))) {
1060                 if (fix_problem(ctx, PR_0_BACKUP_JNL, &pctx)) {
1061                         memcpy(sb->s_jnl_blocks, inode.i_block,
1062                                EXT2_N_BLOCKS*4);
1063                         sb->s_jnl_blocks[15] = inode.i_size_high;
1064                         sb->s_jnl_blocks[16] = inode.i_size;
1065                         sb->s_jnl_backup_type = EXT3_JNL_BACKUP_BLOCKS;
1066                         ext2fs_mark_super_dirty(fs);
1067                         fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
1068                 }
1069         }
1070
1071         /*
1072          * If the journal is already the hidden inode, then do nothing
1073          */
1074         if (sb->s_journal_inum == EXT2_JOURNAL_INO)
1075                 return;
1076
1077         /*
1078          * The journal inode had better have only one link and not be readable.
1079          */
1080         if (inode.i_links_count != 1)
1081                 return;
1082
1083         /*
1084          * If the filesystem is mounted, or we can't tell whether
1085          * or not it's mounted, do nothing.
1086          */
1087         retval = ext2fs_check_if_mounted(ctx->filesystem_name, &mount_flags);
1088         if (retval || (mount_flags & EXT2_MF_MOUNTED))
1089                 return;
1090
1091         /*
1092          * If we can't find the name of the journal inode, then do
1093          * nothing.
1094          */
1095         for (cpp = journal_names; *cpp; cpp++) {
1096                 retval = ext2fs_lookup(fs, EXT2_ROOT_INO, *cpp,
1097                                        strlen(*cpp), 0, &ino);
1098                 if ((retval == 0) && (ino == sb->s_journal_inum))
1099                         break;
1100         }
1101         if (*cpp == 0)
1102                 return;
1103
1104         /* We need the inode bitmap to be loaded */
1105         retval = ext2fs_read_bitmaps(fs);
1106         if (retval)
1107                 return;
1108
1109         pctx.str = *cpp;
1110         if (!fix_problem(ctx, PR_0_MOVE_JOURNAL, &pctx))
1111                 return;
1112
1113         /*
1114          * OK, we've done all the checks, let's actually move the
1115          * journal inode.  Errors at this point mean we need to force
1116          * an ext2 filesystem check.
1117          */
1118         if ((retval = ext2fs_unlink(fs, EXT2_ROOT_INO, *cpp, ino, 0)) != 0)
1119                 goto err_out;
1120         if ((retval = ext2fs_write_inode(fs, EXT2_JOURNAL_INO, &inode)) != 0)
1121                 goto err_out;
1122         sb->s_journal_inum = EXT2_JOURNAL_INO;
1123         ext2fs_mark_super_dirty(fs);
1124         fs->flags &= ~EXT2_FLAG_MASTER_SB_ONLY;
1125         inode.i_links_count = 0;
1126         inode.i_dtime = ctx->now;
1127         if ((retval = ext2fs_write_inode(fs, ino, &inode)) != 0)
1128                 goto err_out;
1129
1130         group = ext2fs_group_of_ino(fs, ino);
1131         ext2fs_unmark_inode_bitmap2(fs->inode_map, ino);
1132         ext2fs_mark_ib_dirty(fs);
1133         ext2fs_bg_free_inodes_count_set(fs, group, ext2fs_bg_free_inodes_count(fs, group) + 1);
1134         ext2fs_group_desc_csum_set(fs, group);
1135         fs->super->s_free_inodes_count++;
1136         return;
1137
1138 err_out:
1139         pctx.errcode = retval;
1140         fix_problem(ctx, PR_0_ERR_MOVE_JOURNAL, &pctx);
1141         fs->super->s_state &= ~EXT2_VALID_FS;
1142         ext2fs_mark_super_dirty(fs);
1143         return;
1144 }
1145
1146 /*
1147  * This function makes sure the superblock hint for the external
1148  * journal is correct.
1149  */
1150 int e2fsck_fix_ext3_journal_hint(e2fsck_t ctx)
1151 {
1152         struct ext2_super_block *sb = ctx->fs->super;
1153         struct problem_context pctx;
1154         char uuid[37], *journal_name;
1155         struct stat st;
1156
1157         if (!ext2fs_has_feature_journal(sb) ||
1158             uuid_is_null(sb->s_journal_uuid))
1159                 return 0;
1160
1161         uuid_unparse(sb->s_journal_uuid, uuid);
1162         journal_name = blkid_get_devname(ctx->blkid, "UUID", uuid);
1163         if (!journal_name)
1164                 return 0;
1165
1166         if (stat(journal_name, &st) < 0) {
1167                 free(journal_name);
1168                 return 0;
1169         }
1170
1171         if (st.st_rdev != sb->s_journal_dev) {
1172                 clear_problem_context(&pctx);
1173                 pctx.num = st.st_rdev;
1174                 if (fix_problem(ctx, PR_0_EXTERNAL_JOURNAL_HINT, &pctx)) {
1175                         sb->s_journal_dev = st.st_rdev;
1176                         ext2fs_mark_super_dirty(ctx->fs);
1177                 }
1178         }
1179
1180         free(journal_name);
1181         return 0;
1182 }