debugfs/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 "uuid/uuid.h"
  27 #include "journal.h"
  28
  29 #ifdef CONFIG_JBD_DEBUG         /* Enabled by configure --enable-jfs-debug */
  30 static int bh_count = 0;
  31 #endif
  32
  33 #if EXT2_FLAT_INCLUDES
  34 #include "blkid.h"
  35 #else
  36 #include "blkid/blkid.h"
  37 #endif
  38
  39 /*
  40  * Define USE_INODE_IO to use the inode_io.c / fileio.c codepaths.
  41  * This creates a larger static binary, and a smaller binary using
  42  * shared libraries.  It's also probably slightly less CPU-efficient,
  43  * which is why it's not on by default.  But, it's a good way of
  44  * testing the functions in inode_io.c and fileio.c.
  45  */
  46 #undef USE_INODE_IO
  47
  48 /* Checksumming functions */
  49 static int ext2fs_journal_verify_csum_type(journal_t *j,
  50                                            journal_superblock_t *jsb)
  51 {
  52         if (!journal_has_csum_v2or3(j))
  53                 return 1;
  54
  55         return jsb->s_checksum_type == JBD2_CRC32C_CHKSUM;
  56 }
  57
  58 static __u32 ext2fs_journal_sb_csum(journal_superblock_t *jsb)
  59 {
  60         __u32 crc, old_crc;
  61
  62         old_crc = jsb->s_checksum;
  63         jsb->s_checksum = 0;
  64         crc = ext2fs_crc32c_le(~0, (unsigned char *)jsb,
  65                                sizeof(journal_superblock_t));
  66         jsb->s_checksum = old_crc;
  67
  68         return crc;
  69 }
  70
  71 static int ext2fs_journal_sb_csum_verify(journal_t *j,
  72                                          journal_superblock_t *jsb)
  73 {
  74         __u32 provided, calculated;
  75
  76         if (!journal_has_csum_v2or3(j))
  77                 return 1;
  78
  79         provided = ext2fs_be32_to_cpu(jsb->s_checksum);
  80         calculated = ext2fs_journal_sb_csum(jsb);
  81
  82         return provided == calculated;
  83 }
  84
  85 static errcode_t ext2fs_journal_sb_csum_set(journal_t *j,
  86                                             journal_superblock_t *jsb)
  87 {
  88         __u32 crc;
  89
  90         if (!journal_has_csum_v2or3(j))
  91                 return 0;
  92
  93         crc = ext2fs_journal_sb_csum(jsb);
  94         jsb->s_checksum = ext2fs_cpu_to_be32(crc);
  95         return 0;
  96 }
  97
  98 /* Kernel compatibility functions for handling the journal.  These allow us
  99  * to use the recovery.c file virtually unchanged from the kernel, so we
 100  * don't have to do much to keep kernel and user recovery in sync.
 101  */
 102 int journal_bmap(journal_t *journal, blk64_t block, unsigned long long *phys)
 103 {
 104 #ifdef USE_INODE_IO
 105         *phys = block;
 106         return 0;
 107 #else
 108         struct inode    *inode = journal->j_inode;
 109         errcode_t       retval;
 110         blk64_t         pblk;
 111
 112         if (!inode) {
 113                 *phys = block;
 114                 return 0;
 115         }
 116
 117         retval = ext2fs_bmap2(inode->i_fs, inode->i_ino,
 118                               &inode->i_ext2, NULL, 0, block, 0, &pblk);
 119         *phys = pblk;
 120         return (int) retval;
 121 #endif
 122 }
 123
 124 struct buffer_head *getblk(kdev_t kdev, blk64_t blocknr, int blocksize)
 125 {
 126         struct buffer_head *bh;
 127         int bufsize = sizeof(*bh) + kdev->k_fs->blocksize -
 128                 sizeof(bh->b_data);
 129         errcode_t retval;
 130
 131         retval = ext2fs_get_memzero(bufsize, &bh);
 132         if (retval)
 133                 return NULL;
 134
 135 #ifdef CONFIG_JBD_DEBUG
 136         if (journal_enable_debug >= 3)
 137                 bh_count++;
 138 #endif
 139         jfs_debug(4, "getblk for block %llu (%d bytes)(total %d)\n",
 140                   (unsigned long long) blocknr, blocksize, bh_count);
 141
 142         bh->b_fs = kdev->k_fs;
 143         if (kdev->k_dev == K_DEV_FS)
 144                 bh->b_io = kdev->k_fs->io;
 145         else
 146                 bh->b_io = kdev->k_fs->journal_io;
 147         bh->b_size = blocksize;
 148         bh->b_blocknr = blocknr;
 149
 150         return bh;
 151 }
 152
 153 int sync_blockdev(kdev_t kdev)
 154 {
 155         io_channel      io;
 156
 157         if (kdev->k_dev == K_DEV_FS)
 158                 io = kdev->k_fs->io;
 159         else
 160                 io = kdev->k_fs->journal_io;
 161
 162         return io_channel_flush(io) ? EIO : 0;
 163 }
 164
 165 void ll_rw_block(int rw, int nr, struct buffer_head *bhp[])
 166 {
 167         errcode_t retval;
 168         struct buffer_head *bh;
 169
 170         for (; nr > 0; --nr) {
 171                 bh = *bhp++;
 172                 if (rw == READ && !bh->b_uptodate) {
 173                         jfs_debug(3, "reading block %llu/%p\n",
 174                                   bh->b_blocknr, (void *) bh);
 175                         retval = io_channel_read_blk64(bh->b_io,
 176                                                      bh->b_blocknr,
 177                                                      1, bh->b_data);
 178                         if (retval) {
 179                                 com_err(bh->b_fs->device_name, retval,
 180                                         "while reading block %llu\n",
 181                                         bh->b_blocknr);
 182                                 bh->b_err = (int) retval;
 183                                 continue;
 184                         }
 185                         bh->b_uptodate = 1;
 186                 } else if (rw == WRITE && bh->b_dirty) {
 187                         jfs_debug(3, "writing block %llu/%p\n",
 188                                   bh->b_blocknr,
 189                                   (void *) bh);
 190                         retval = io_channel_write_blk64(bh->b_io,
 191                                                       bh->b_blocknr,
 192                                                       1, bh->b_data);
 193                         if (retval) {
 194                                 com_err(bh->b_fs->device_name, retval,
 195                                         "while writing block %llu\n",
 196                                         bh->b_blocknr);
 197                                 bh->b_err = (int) retval;
 198                                 continue;
 199                         }
 200                         bh->b_dirty = 0;
 201                         bh->b_uptodate = 1;
 202                 } else {
 203                         jfs_debug(3, "no-op %s for block %llu\n",
 204                                   rw == READ ? "read" : "write",
 205                                   bh->b_blocknr);
 206                 }
 207         }
 208 }
 209
 210 void mark_buffer_dirty(struct buffer_head *bh)
 211 {
 212         bh->b_dirty = 1;
 213 }
 214
 215 static void mark_buffer_clean(struct buffer_head *bh)
 216 {
 217         bh->b_dirty = 0;
 218 }
 219
 220 void brelse(struct buffer_head *bh)
 221 {
 222         if (bh->b_dirty)
 223                 ll_rw_block(WRITE, 1, &bh);
 224         jfs_debug(3, "freeing block %llu/%p (total %d)\n",
 225                   bh->b_blocknr, (void *) bh, --bh_count);
 226         ext2fs_free_mem(&bh);
 227 }
 228
 229 int buffer_uptodate(struct buffer_head *bh)
 230 {
 231         return bh->b_uptodate;
 232 }
 233
 234 void mark_buffer_uptodate(struct buffer_head *bh, int val)
 235 {
 236         bh->b_uptodate = val;
 237 }
 238
 239 void wait_on_buffer(struct buffer_head *bh)
 240 {
 241         if (!bh->b_uptodate)
 242                 ll_rw_block(READ, 1, &bh);
 243 }
 244
 245
 246 static void ext2fs_clear_recover(ext2_filsys fs, int error)
 247 {
 248         ext2fs_clear_feature_journal_needs_recovery(fs->super);
 249
 250         /* if we had an error doing journal recovery, we need a full fsck */
 251         if (error)
 252                 fs->super->s_state &= ~EXT2_VALID_FS;
 253         ext2fs_mark_super_dirty(fs);
 254 }
 255
 256 /*
 257  * This is a helper function to check the validity of the journal.
 258  */
 259 struct process_block_struct {
 260         e2_blkcnt_t     last_block;
 261 };
 262
 263 static int process_journal_block(ext2_filsys fs,
 264                                  blk64_t        *block_nr,
 265                                  e2_blkcnt_t blockcnt,
 266                                  blk64_t ref_block EXT2FS_ATTR((unused)),
 267                                  int ref_offset EXT2FS_ATTR((unused)),
 268                                  void *priv_data)
 269 {
 270         struct process_block_struct *p;
 271         blk64_t blk = *block_nr;
 272
 273         p = (struct process_block_struct *) priv_data;
 274
 275         if (!blk || blk < fs->super->s_first_data_block ||
 276             blk >= ext2fs_blocks_count(fs->super))
 277                 return BLOCK_ABORT;
 278
 279         if (blockcnt >= 0)
 280                 p->last_block = blockcnt;
 281         return 0;
 282 }
 283
 284 static errcode_t ext2fs_get_journal(ext2_filsys fs, journal_t **ret_journal)
 285 {
 286         struct process_block_struct pb;
 287         struct ext2_super_block *sb = fs->super;
 288         struct ext2_super_block jsuper;
 289         struct buffer_head      *bh;
 290         struct inode            *j_inode = NULL;
 291         struct kdev_s           *dev_fs = NULL, *dev_journal;
 292         const char              *journal_name = 0;
 293         journal_t               *journal = NULL;
 294         errcode_t               retval = 0;
 295         io_manager              io_ptr = 0;
 296         unsigned long long      start = 0;
 297         int                     ext_journal = 0;
 298         int                     tried_backup_jnl = 0;
 299
 300         retval = ext2fs_get_memzero(sizeof(journal_t), &journal);
 301         if (retval)
 302                 return retval;
 303
 304         retval = ext2fs_get_memzero(2 * sizeof(struct kdev_s), &dev_fs);
 305         if (retval)
 306                 goto errout;
 307         dev_journal = dev_fs+1;
 308
 309         dev_fs->k_fs = dev_journal->k_fs = fs;
 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 = 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                 retval = ext2fs_get_memzero(sizeof(*j_inode), &j_inode);
 324                 if (retval)
 325                         goto errout;
 326
 327                 j_inode->i_fs = fs;
 328                 j_inode->i_ino = sb->s_journal_inum;
 329
 330                 retval = ext2fs_read_inode(fs, sb->s_journal_inum,
 331                                            &j_inode->i_ext2);
 332                 if (retval) {
 333 try_backup_journal:
 334                         if (sb->s_jnl_backup_type != EXT3_JNL_BACKUP_BLOCKS ||
 335                             tried_backup_jnl)
 336                                 goto errout;
 337                         memset(&j_inode->i_ext2, 0, sizeof(struct ext2_inode));
 338                         memcpy(&j_inode->i_ext2.i_block[0], sb->s_jnl_blocks,
 339                                EXT2_N_BLOCKS*4);
 340                         j_inode->i_ext2.i_size_high = sb->s_jnl_blocks[15];
 341                         j_inode->i_ext2.i_size = sb->s_jnl_blocks[16];
 342                         j_inode->i_ext2.i_links_count = 1;
 343                         j_inode->i_ext2.i_mode = LINUX_S_IFREG | 0600;
 344                         tried_backup_jnl++;
 345                 }
 346                 if (!j_inode->i_ext2.i_links_count ||
 347                     !LINUX_S_ISREG(j_inode->i_ext2.i_mode)) {
 348                         retval = EXT2_ET_NO_JOURNAL;
 349                         goto try_backup_journal;
 350                 }
 351                 if (EXT2_I_SIZE(&j_inode->i_ext2) / journal->j_blocksize <
 352                     JFS_MIN_JOURNAL_BLOCKS) {
 353                         retval = EXT2_ET_JOURNAL_TOO_SMALL;
 354                         goto try_backup_journal;
 355                 }
 356                 pb.last_block = -1;
 357                 retval = ext2fs_block_iterate3(fs, j_inode->i_ino,
 358                                                BLOCK_FLAG_HOLE, 0,
 359                                                process_journal_block, &pb);
 360                 if ((pb.last_block + 1) * fs->blocksize <
 361                     (int) EXT2_I_SIZE(&j_inode->i_ext2)) {
 362                         retval = EXT2_ET_JOURNAL_TOO_SMALL;
 363                         goto try_backup_journal;
 364                 }
 365                 if (tried_backup_jnl && (fs->flags & EXT2_FLAG_RW)) {
 366                         retval = ext2fs_write_inode(fs, sb->s_journal_inum,
 367                                                     &j_inode->i_ext2);
 368                         if (retval)
 369                                 goto errout;
 370                 }
 371
 372                 journal->j_maxlen = EXT2_I_SIZE(&j_inode->i_ext2) /
 373                         journal->j_blocksize;
 374
 375 #ifdef USE_INODE_IO
 376                 retval = ext2fs_inode_io_intern2(fs, sb->s_journal_inum,
 377                                                  &j_inode->i_ext2,
 378                                                  &journal_name);
 379                 if (retval)
 380                         goto errout;
 381
 382                 io_ptr = inode_io_manager;
 383 #else
 384                 journal->j_inode = j_inode;
 385                 fs->journal_io = fs->io;
 386                 retval = (errcode_t)journal_bmap(journal, 0, &start);
 387                 if (retval)
 388                         goto errout;
 389 #endif
 390         } else {
 391                 ext_journal = 1;
 392                 if (!fs->journal_name) {
 393                         char uuid[37];
 394                         blkid_cache blkid;
 395
 396                         blkid_get_cache(&blkid, NULL);
 397                         uuid_unparse(sb->s_journal_uuid, uuid);
 398                         fs->journal_name = blkid_get_devname(blkid,
 399                                                               "UUID", uuid);
 400                         if (!fs->journal_name)
 401                                 fs->journal_name = blkid_devno_to_devname(sb->s_journal_dev);
 402                         blkid_put_cache(blkid);
 403                 }
 404                 journal_name = fs->journal_name;
 405
 406                 if (!journal_name) {
 407                         retval = EXT2_ET_LOAD_EXT_JOURNAL;
 408                         goto errout;
 409                 }
 410
 411                 jfs_debug(1, "Using journal file %s\n", journal_name);
 412                 io_ptr = unix_io_manager;
 413         }
 414
 415 #if 0
 416         test_io_backing_manager = io_ptr;
 417         io_ptr = test_io_manager;
 418 #endif
 419 #ifndef USE_INODE_IO
 420         if (ext_journal)
 421 #endif
 422         {
 423                 retval = io_ptr->open(journal_name, fs->flags & EXT2_FLAG_RW,
 424                                       &fs->journal_io);
 425         }
 426         if (retval)
 427                 goto errout;
 428
 429         io_channel_set_blksize(fs->journal_io, fs->blocksize);
 430
 431         if (ext_journal) {
 432                 blk64_t maxlen;
 433
 434                 start = ext2fs_journal_sb_start(fs->blocksize) - 1;
 435                 bh = getblk(dev_journal, start, fs->blocksize);
 436                 if (!bh) {
 437                         retval = EXT2_ET_NO_MEMORY;
 438                         goto errout;
 439                 }
 440                 ll_rw_block(READ, 1, &bh);
 441                 retval = bh->b_err;
 442                 if (retval) {
 443                         brelse(bh);
 444                         goto errout;
 445                 }
 446                 memcpy(&jsuper, start ? bh->b_data :
 447                                 bh->b_data + SUPERBLOCK_OFFSET,
 448                        sizeof(jsuper));
 449 #ifdef WORDS_BIGENDIAN
 450                 if (jsuper.s_magic == ext2fs_swab16(EXT2_SUPER_MAGIC))
 451                         ext2fs_swap_super(&jsuper);
 452 #endif
 453                 if (jsuper.s_magic != EXT2_SUPER_MAGIC ||
 454                     !ext2fs_has_feature_journal_dev(&jsuper)) {
 455                         retval = EXT2_ET_LOAD_EXT_JOURNAL;
 456                         brelse(bh);
 457                         goto errout;
 458                 }
 459                 /* Make sure the journal UUID is correct */
 460                 if (memcmp(jsuper.s_uuid, fs->super->s_journal_uuid,
 461                            sizeof(jsuper.s_uuid))) {
 462                         retval = EXT2_ET_LOAD_EXT_JOURNAL;
 463                         brelse(bh);
 464                         goto errout;
 465                 }
 466
 467                 /* Check the superblock checksum */
 468                 if (ext2fs_has_feature_metadata_csum(&jsuper)) {
 469                         struct struct_ext2_filsys fsx;
 470                         struct ext2_super_block superx;
 471                         void *p;
 472
 473                         p = start ? bh->b_data : bh->b_data + SUPERBLOCK_OFFSET;
 474                         memcpy(&fsx, fs, sizeof(fsx));
 475                         memcpy(&superx, fs->super, sizeof(superx));
 476                         fsx.super = &superx;
 477                         ext2fs_set_feature_metadata_csum(fsx.super);
 478                         if (!ext2fs_superblock_csum_verify(&fsx, p)) {
 479                                 retval = EXT2_ET_LOAD_EXT_JOURNAL;
 480                                 brelse(bh);
 481                                 goto errout;
 482                         }
 483                 }
 484                 brelse(bh);
 485
 486                 maxlen = ext2fs_blocks_count(&jsuper);
 487                 journal->j_maxlen = (maxlen < 1ULL << 32) ? maxlen :
 488                                     (1ULL << 32) - 1;
 489                 start++;
 490         }
 491
 492         bh = getblk(dev_journal, start, journal->j_blocksize);
 493         if (!bh) {
 494                 retval = EXT2_ET_NO_MEMORY;
 495                 goto errout;
 496         }
 497
 498         journal->j_sb_buffer = bh;
 499         journal->j_superblock = (journal_superblock_t *)bh->b_data;
 500
 501 #ifdef USE_INODE_IO
 502         if (j_inode)
 503                 ext2fs_free_mem(&j_inode);
 504 #endif
 505
 506         *ret_journal = journal;
 507         return 0;
 508
 509 errout:
 510         if (dev_fs)
 511                 ext2fs_free_mem(&dev_fs);
 512         if (j_inode)
 513                 ext2fs_free_mem(&j_inode);
 514         if (journal)
 515                 ext2fs_free_mem(&journal);
 516         return retval;
 517 }
 518
 519 static errcode_t ext2fs_journal_fix_bad_inode(ext2_filsys fs)
 520 {
 521         struct ext2_super_block *sb = fs->super;
 522         int recover = ext2fs_has_feature_journal_needs_recovery(fs->super);
 523         int has_journal = ext2fs_has_feature_journal(fs->super);
 524
 525         if (has_journal || sb->s_journal_inum) {
 526                 /* The journal inode is bogus, remove and force full fsck */
 527                 return EXT2_ET_BAD_INODE_NUM;
 528         } else if (recover) {
 529                 return EXT2_ET_UNSUPP_FEATURE;
 530         }
 531         return 0;
 532 }
 533
 534 #define V1_SB_SIZE      0x0024
 535 static void clear_v2_journal_fields(journal_t *journal)
 536 {
 537         ext2_filsys fs = journal->j_dev->k_fs;
 538
 539         memset(((char *) journal->j_superblock) + V1_SB_SIZE, 0,
 540                fs->blocksize-V1_SB_SIZE);
 541         mark_buffer_dirty(journal->j_sb_buffer);
 542 }
 543
 544
 545 static errcode_t ext2fs_journal_load(journal_t *journal)
 546 {
 547         ext2_filsys fs = journal->j_dev->k_fs;
 548         journal_superblock_t *jsb;
 549         struct buffer_head *jbh = journal->j_sb_buffer;
 550
 551         ll_rw_block(READ, 1, &jbh);
 552         if (jbh->b_err)
 553                 return jbh->b_err;
 554
 555         jsb = journal->j_superblock;
 556         /* If we don't even have JFS_MAGIC, we probably have a wrong inode */
 557         if (jsb->s_header.h_magic != htonl(JFS_MAGIC_NUMBER))
 558                 return ext2fs_journal_fix_bad_inode(fs);
 559
 560         switch (ntohl(jsb->s_header.h_blocktype)) {
 561         case JFS_SUPERBLOCK_V1:
 562                 journal->j_format_version = 1;
 563                 if (jsb->s_feature_compat ||
 564                     jsb->s_feature_incompat ||
 565                     jsb->s_feature_ro_compat ||
 566                     jsb->s_nr_users)
 567                         clear_v2_journal_fields(journal);
 568                 break;
 569
 570         case JFS_SUPERBLOCK_V2:
 571                 journal->j_format_version = 2;
 572                 if (ntohl(jsb->s_nr_users) > 1 &&
 573                     uuid_is_null(fs->super->s_journal_uuid))
 574                         clear_v2_journal_fields(journal);
 575                 if (ntohl(jsb->s_nr_users) > 1)
 576                         return EXT2_ET_JOURNAL_UNSUPP_VERSION;
 577                 break;
 578
 579         /*
 580          * These should never appear in a journal super block, so if
 581          * they do, the journal is badly corrupted.
 582          */
 583         case JFS_DESCRIPTOR_BLOCK:
 584         case JFS_COMMIT_BLOCK:
 585         case JFS_REVOKE_BLOCK:
 586                 return EXT2_ET_CORRUPT_JOURNAL_SB;
 587
 588         /* If we don't understand the superblock major type, but there
 589          * is a magic number, then it is likely to be a new format we
 590          * just don't understand, so leave it alone. */
 591         default:
 592                 return EXT2_ET_JOURNAL_UNSUPP_VERSION;
 593         }
 594
 595         if (JFS_HAS_INCOMPAT_FEATURE(journal, ~JFS_KNOWN_INCOMPAT_FEATURES))
 596                 return EXT2_ET_UNSUPP_FEATURE;
 597
 598         if (JFS_HAS_RO_COMPAT_FEATURE(journal, ~JFS_KNOWN_ROCOMPAT_FEATURES))
 599                 return EXT2_ET_RO_UNSUPP_FEATURE;
 600
 601         /* Checksum v1-3 are mutually exclusive features. */
 602         if (jfs_has_feature_csum2(journal) && jfs_has_feature_csum3(journal))
 603                 return EXT2_ET_CORRUPT_JOURNAL_SB;
 604
 605         if (journal_has_csum_v2or3(journal) &&
 606             jfs_has_feature_checksum(journal))
 607                 return EXT2_ET_CORRUPT_JOURNAL_SB;
 608
 609         if (!ext2fs_journal_verify_csum_type(journal, jsb) ||
 610             !ext2fs_journal_sb_csum_verify(journal, jsb))
 611                 return EXT2_ET_CORRUPT_JOURNAL_SB;
 612
 613         if (journal_has_csum_v2or3(journal))
 614                 journal->j_csum_seed = jbd2_chksum(journal, ~0, jsb->s_uuid,
 615                                                    sizeof(jsb->s_uuid));
 616
 617         /* We have now checked whether we know enough about the journal
 618          * format to be able to proceed safely, so any other checks that
 619          * fail we should attempt to recover from. */
 620         if (jsb->s_blocksize != htonl(journal->j_blocksize))
 621                 return EXT2_ET_CORRUPT_JOURNAL_SB;
 622
 623         if (ntohl(jsb->s_maxlen) < journal->j_maxlen)
 624                 journal->j_maxlen = ntohl(jsb->s_maxlen);
 625         else if (ntohl(jsb->s_maxlen) > journal->j_maxlen)
 626                 return EXT2_ET_CORRUPT_JOURNAL_SB;
 627
 628         journal->j_tail_sequence = ntohl(jsb->s_sequence);
 629         journal->j_transaction_sequence = journal->j_tail_sequence;
 630         journal->j_tail = ntohl(jsb->s_start);
 631         journal->j_first = ntohl(jsb->s_first);
 632         journal->j_last = ntohl(jsb->s_maxlen);
 633
 634         return 0;
 635 }
 636
 637 static void ext2fs_journal_release(ext2_filsys fs, journal_t *journal,
 638                                    int reset, int drop)
 639 {
 640         journal_superblock_t *jsb;
 641
 642         if (drop)
 643                 mark_buffer_clean(journal->j_sb_buffer);
 644         else if (fs->flags & EXT2_FLAG_RW) {
 645                 jsb = journal->j_superblock;
 646                 jsb->s_sequence = htonl(journal->j_tail_sequence);
 647                 if (reset)
 648                         jsb->s_start = 0; /* this marks the journal as empty */
 649                 ext2fs_journal_sb_csum_set(journal, jsb);
 650                 mark_buffer_dirty(journal->j_sb_buffer);
 651         }
 652         brelse(journal->j_sb_buffer);
 653
 654         if (fs && fs->journal_io) {
 655                 if (fs->io != fs->journal_io)
 656                         io_channel_close(fs->journal_io);
 657                 fs->journal_io = NULL;
 658                 free(fs->journal_name);
 659                 fs->journal_name = NULL;
 660         }
 661
 662 #ifndef USE_INODE_IO
 663         if (journal->j_inode)
 664                 ext2fs_free_mem(&journal->j_inode);
 665 #endif
 666         if (journal->j_fs_dev)
 667                 ext2fs_free_mem(&journal->j_fs_dev);
 668         ext2fs_free_mem(&journal);
 669 }
 670
 671 /*
 672  * This function makes sure that the superblock fields regarding the
 673  * journal are consistent.
 674  */
 675 static errcode_t ext2fs_check_ext3_journal(ext2_filsys fs)
 676 {
 677         struct ext2_super_block *sb = fs->super;
 678         journal_t *journal;
 679         int recover = ext2fs_has_feature_journal_needs_recovery(fs->super);
 680         errcode_t retval;
 681
 682         /* If we don't have any journal features, don't do anything more */
 683         if (!ext2fs_has_feature_journal(sb) &&
 684             !recover && sb->s_journal_inum == 0 && sb->s_journal_dev == 0 &&
 685             uuid_is_null(sb->s_journal_uuid))
 686                 return 0;
 687
 688         retval = ext2fs_get_journal(fs, &journal);
 689         if (retval)
 690                 return retval;
 691
 692         retval = ext2fs_journal_load(journal);
 693         if (retval)
 694                 goto err;
 695
 696         /*
 697          * We want to make the flags consistent here.  We will not leave with
 698          * needs_recovery set but has_journal clear.  We can't get in a loop
 699          * with -y, -n, or -p, only if a user isn't making up their mind.
 700          */
 701         if (!ext2fs_has_feature_journal(sb)) {
 702                 retval = EXT2_ET_JOURNAL_FLAGS_WRONG;
 703                 goto err;
 704         }
 705
 706         if (ext2fs_has_feature_journal(sb) &&
 707             !ext2fs_has_feature_journal_needs_recovery(sb) &&
 708             journal->j_superblock->s_start != 0) {
 709                 retval = EXT2_ET_JOURNAL_FLAGS_WRONG;
 710                 goto err;
 711         }
 712
 713         /*
 714          * If we don't need to do replay the journal, check to see if
 715          * the journal's errno is set; if so, we need to mark the file
 716          * system as being corrupt and clear the journal's s_errno.
 717          */
 718         if (!ext2fs_has_feature_journal_needs_recovery(sb) &&
 719             journal->j_superblock->s_errno) {
 720                 fs->super->s_state |= EXT2_ERROR_FS;
 721                 ext2fs_mark_super_dirty(fs);
 722                 journal->j_superblock->s_errno = 0;
 723                 ext2fs_journal_sb_csum_set(journal, journal->j_superblock);
 724                 mark_buffer_dirty(journal->j_sb_buffer);
 725         }
 726
 727 err:
 728         ext2fs_journal_release(fs, journal, 0, retval ? 1 : 0);
 729         return retval;
 730 }
 731
 732 static errcode_t recover_ext3_journal(ext2_filsys fs)
 733 {
 734         journal_t *journal;
 735         errcode_t retval;
 736
 737         journal_init_revoke_caches();
 738         retval = ext2fs_get_journal(fs, &journal);
 739         if (retval)
 740                 return retval;
 741
 742         retval = ext2fs_journal_load(journal);
 743         if (retval)
 744                 goto errout;
 745
 746         retval = journal_init_revoke(journal, 1024);
 747         if (retval)
 748                 goto errout;
 749
 750         retval = -journal_recover(journal);
 751         if (retval)
 752                 goto errout;
 753
 754         if (journal->j_failed_commit) {
 755                 journal->j_superblock->s_errno = -EINVAL;
 756                 mark_buffer_dirty(journal->j_sb_buffer);
 757         }
 758
 759 errout:
 760         journal_destroy_revoke(journal);
 761         journal_destroy_revoke_caches();
 762         ext2fs_journal_release(fs, journal, 1, 0);
 763         return retval;
 764 }
 765
 766 errcode_t ext2fs_run_ext3_journal(ext2_filsys *fsp)
 767 {
 768         ext2_filsys fs = *fsp;
 769         io_manager io_ptr = fs->io->manager;
 770         errcode_t       retval, recover_retval;
 771         io_stats        stats = 0;
 772         unsigned long long kbytes_written = 0;
 773         char *fsname;
 774         int fsflags;
 775         int fsblocksize;
 776
 777         if (!(fs->flags & EXT2_FLAG_RW))
 778                 return EXT2_ET_FILE_RO;
 779
 780         if (fs->flags & EXT2_FLAG_DIRTY)
 781                 ext2fs_flush(fs);       /* Force out any modifications */
 782
 783         recover_retval = recover_ext3_journal(fs);
 784
 785         /*
 786          * Reload the filesystem context to get up-to-date data from disk
 787          * because journal recovery will change the filesystem under us.
 788          */
 789         if (fs->super->s_kbytes_written &&
 790             fs->io->manager->get_stats)
 791                 fs->io->manager->get_stats(fs->io, &stats);
 792         if (stats && stats->bytes_written)
 793                 kbytes_written = stats->bytes_written >> 10;
 794
 795         ext2fs_mmp_stop(fs);
 796         fsname = strdup(fs->device_name);
 797         fsflags = fs->flags;
 798         fsblocksize = fs->blocksize;
 799         ext2fs_free(fs);
 800         retval = ext2fs_open(fsname, fsflags,
 801                              0, fsblocksize, io_ptr,
 802                              fsp);
 803         free(fsname);
 804         if (retval)
 805                 return retval;
 806
 807         fs = *fsp;
 808         fs->flags |= EXT2_FLAG_MASTER_SB_ONLY;
 809         fs->super->s_kbytes_written += kbytes_written;
 810
 811         /* Set the superblock flags */
 812         ext2fs_clear_recover(fs, recover_retval != 0);
 813
 814         /*
 815          * Do one last sanity check, and propagate journal->s_errno to
 816          * the EXT2_ERROR_FS flag in the fs superblock if needed.
 817          */
 818         retval = ext2fs_check_ext3_journal(fs);
 819         return retval ? retval : recover_retval;
 820 }
 821
 822 errcode_t ext2fs_open_journal(ext2_filsys fs, journal_t **j)
 823 {
 824         journal_t *journal;
 825         errcode_t retval;
 826
 827         journal_init_revoke_caches();
 828         retval = ext2fs_get_journal(fs, &journal);
 829         if (retval)
 830                 return retval;
 831
 832         retval = ext2fs_journal_load(journal);
 833         if (retval)
 834                 goto errout;
 835
 836         retval = journal_init_revoke(journal, 1024);
 837         if (retval)
 838                 goto errout;
 839
 840         if (journal->j_failed_commit) {
 841                 journal->j_superblock->s_errno = -EINVAL;
 842                 mark_buffer_dirty(journal->j_sb_buffer);
 843         }
 844
 845         *j = journal;
 846         return 0;
 847
 848 errout:
 849         journal_destroy_revoke(journal);
 850         journal_destroy_revoke_caches();
 851         ext2fs_journal_release(fs, journal, 1, 0);
 852         return retval;
 853 }
 854
 855 errcode_t ext2fs_close_journal(ext2_filsys fs, journal_t **j)
 856 {
 857         journal_t *journal = *j;
 858
 859         journal_destroy_revoke(journal);
 860         journal_destroy_revoke_caches();
 861         ext2fs_journal_release(fs, journal, 0, 0);
 862         *j = NULL;
 863
 864         return 0;
 865 }
 866
 867 void jbd2_commit_block_csum_set(journal_t *j, struct buffer_head *bh)
 868 {
 869         struct commit_header *h;
 870         __u32 csum;
 871
 872         if (!journal_has_csum_v2or3(j))
 873                 return;
 874
 875         h = (struct commit_header *)(bh->b_data);
 876         h->h_chksum_type = 0;
 877         h->h_chksum_size = 0;
 878         h->h_chksum[0] = 0;
 879         csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize);
 880         h->h_chksum[0] = ext2fs_cpu_to_be32(csum);
 881 }
 882
 883 void jbd2_revoke_csum_set(journal_t *j, struct buffer_head *bh)
 884 {
 885         struct journal_revoke_tail *tail;
 886         __u32 csum;
 887
 888         if (!journal_has_csum_v2or3(j))
 889                 return;
 890
 891         tail = (struct journal_revoke_tail *)(bh->b_data + j->j_blocksize -
 892                         sizeof(struct journal_revoke_tail));
 893         tail->r_checksum = 0;
 894         csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize);
 895         tail->r_checksum = ext2fs_cpu_to_be32(csum);
 896 }
 897
 898 void jbd2_descr_block_csum_set(journal_t *j, struct buffer_head *bh)
 899 {
 900         struct journal_block_tail *tail;
 901         __u32 csum;
 902
 903         if (!journal_has_csum_v2or3(j))
 904                 return;
 905
 906         tail = (struct journal_block_tail *)(bh->b_data + j->j_blocksize -
 907                         sizeof(struct journal_block_tail));
 908         tail->t_checksum = 0;
 909         csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize);
 910         tail->t_checksum = ext2fs_cpu_to_be32(csum);
 911 }
 912
 913 void jbd2_block_tag_csum_set(journal_t *j, journal_block_tag_t *tag,
 914                              struct buffer_head *bh, __u32 sequence)
 915 {
 916         journal_block_tag3_t *tag3 = (journal_block_tag3_t *)tag;
 917         __u32 csum32;
 918         __be32 seq;
 919
 920         if (!journal_has_csum_v2or3(j))
 921                 return;
 922
 923         seq = ext2fs_cpu_to_be32(sequence);
 924         csum32 = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&seq, sizeof(seq));
 925         csum32 = jbd2_chksum(j, csum32, bh->b_data, bh->b_size);
 926
 927         if (jfs_has_feature_csum3(j))
 928                 tag3->t_checksum = ext2fs_cpu_to_be32(csum32);
 929         else
 930                 tag->t_checksum = ext2fs_cpu_to_be16(csum32);
 931 }
 932