debugfs/do_journal.c

   1 /*
   2  * do_journal.c --- Scribble onto the journal!
   3  *
   4  * Copyright (C) 2014 Oracle.  This file may be redistributed
   5  * under the terms of the GNU Public License.
   6  */
   7
   8 #include "config.h"
   9 #include <stdio.h>
  10 #ifdef HAVE_GETOPT_H
  11 #include <getopt.h>
  12 #else
  13 extern int optind;
  14 extern char *optarg;
  15 #endif
  16 #include <ctype.h>
  17 #include <unistd.h>
  18 #ifdef HAVE_SYS_TIME_H
  19 #include <sys/time.h>
  20 #endif
  21
  22 #include "debugfs.h"
  23 #include "ext2fs/kernel-jbd.h"
  24 #include "journal.h"
  25
  26 #undef DEBUG
  27
  28 #ifdef DEBUG
  29 # define dbg_printf(f, a...)  do {printf("JFS DEBUG: " f, ## a); \
  30         fflush(stdout); \
  31 } while (0)
  32 #else
  33 # define dbg_printf(f, a...)
  34 #endif
  35
  36 #define JOURNAL_CHECK_TRANS_MAGIC(x)    \
  37         do { \
  38                 if ((x)->magic != J_TRANS_MAGIC) \
  39                         return EXT2_ET_INVALID_ARGUMENT; \
  40         } while (0)
  41
  42 #define J_TRANS_MAGIC           0xD15EA5ED
  43 #define J_TRANS_OPEN            1
  44 #define J_TRANS_COMMITTED       2
  45 struct journal_transaction_s {
  46         unsigned int magic;
  47         ext2_filsys fs;
  48         journal_t *journal;
  49         blk64_t block;
  50         blk64_t start, end;
  51         tid_t tid;
  52         int flags;
  53 };
  54
  55 typedef struct journal_transaction_s journal_transaction_t;
  56
  57 static journal_t *current_journal = NULL;
  58
  59 static void journal_dump_trans(journal_transaction_t *trans EXT2FS_ATTR((unused)),
  60                                const char *tag EXT2FS_ATTR((unused)))
  61 {
  62         dbg_printf("TRANS %p(%s): tid=%d start=%llu block=%llu end=%llu "
  63                    "flags=0x%x\n", trans, tag, trans->tid, trans->start,
  64                    trans->block, trans->end, trans->flags);
  65 }
  66
  67 static errcode_t journal_commit_trans(journal_transaction_t *trans)
  68 {
  69         struct buffer_head *bh, *cbh = NULL;
  70         struct commit_header *commit;
  71 #ifdef HAVE_SYS_TIME_H
  72         struct timeval tv;
  73 #endif
  74         errcode_t err;
  75
  76         JOURNAL_CHECK_TRANS_MAGIC(trans);
  77
  78         if ((trans->flags & J_TRANS_COMMITTED) ||
  79             !(trans->flags & J_TRANS_OPEN))
  80                 return EXT2_ET_INVALID_ARGUMENT;
  81
  82         bh = getblk(trans->journal->j_dev, 0, trans->journal->j_blocksize);
  83         if (bh == NULL)
  84                 return ENOMEM;
  85
  86         /* write the descriptor block header */
  87         commit = (struct commit_header *)bh->b_data;
  88         commit->h_magic = ext2fs_cpu_to_be32(JFS_MAGIC_NUMBER);
  89         commit->h_blocktype = ext2fs_cpu_to_be32(JFS_COMMIT_BLOCK);
  90         commit->h_sequence = ext2fs_cpu_to_be32(trans->tid);
  91         if (jfs_has_feature_checksum(trans->journal)) {
  92                 __u32 csum_v1 = ~0;
  93                 blk64_t cblk;
  94
  95                 cbh = getblk(trans->journal->j_dev, 0,
  96                              trans->journal->j_blocksize);
  97                 if (cbh == NULL) {
  98                         err = ENOMEM;
  99                         goto error;
 100                 }
 101
 102                 for (cblk = trans->start; cblk < trans->block; cblk++) {
 103                         err = journal_bmap(trans->journal, cblk,
 104                                            &cbh->b_blocknr);
 105                         if (err)
 106                                 goto error;
 107                         mark_buffer_uptodate(cbh, 0);
 108                         ll_rw_block(READ, 1, &cbh);
 109                         err = cbh->b_err;
 110                         if (err)
 111                                 goto error;
 112                         csum_v1 = ext2fs_crc32_be(csum_v1,
 113                                         (unsigned char const *)cbh->b_data,
 114                                         cbh->b_size);
 115                 }
 116
 117                 commit->h_chksum_type = JFS_CRC32_CHKSUM;
 118                 commit->h_chksum_size = JFS_CRC32_CHKSUM_SIZE;
 119                 commit->h_chksum[0] = ext2fs_cpu_to_be32(csum_v1);
 120         } else {
 121                 commit->h_chksum_type = 0;
 122                 commit->h_chksum_size = 0;
 123                 commit->h_chksum[0] = 0;
 124         }
 125 #ifdef HAVE_SYS_TIME_H
 126         gettimeofday(&tv, NULL);
 127         commit->h_commit_sec = ext2fs_cpu_to_be32(tv.tv_sec);
 128         commit->h_commit_nsec = ext2fs_cpu_to_be32(tv.tv_usec * 1000);
 129 #else
 130         commit->h_commit_sec = 0;
 131         commit->h_commit_nsec = 0;
 132 #endif
 133
 134         /* Write block */
 135         jbd2_commit_block_csum_set(trans->journal, bh);
 136         err = journal_bmap(trans->journal, trans->block, &bh->b_blocknr);
 137         if (err)
 138                 goto error;
 139
 140         dbg_printf("Writing commit block at %llu:%llu\n", trans->block,
 141                    bh->b_blocknr);
 142         mark_buffer_dirty(bh);
 143         ll_rw_block(WRITE, 1, &bh);
 144         err = bh->b_err;
 145         if (err)
 146                 goto error;
 147         trans->flags |= J_TRANS_COMMITTED;
 148         trans->flags &= ~J_TRANS_OPEN;
 149         trans->block++;
 150
 151         ext2fs_set_feature_journal_needs_recovery(trans->fs->super);
 152         ext2fs_mark_super_dirty(trans->fs);
 153 error:
 154         if (cbh)
 155                 brelse(cbh);
 156         brelse(bh);
 157         return err;
 158 }
 159
 160 static errcode_t journal_add_revoke_to_trans(journal_transaction_t *trans,
 161                                              blk64_t *revoke_list,
 162                                              size_t revoke_len)
 163 {
 164         journal_revoke_header_t *jrb;
 165         void *buf;
 166         size_t i, offset;
 167         blk64_t curr_blk;
 168         unsigned int sz;
 169         unsigned csum_size = 0;
 170         struct buffer_head *bh;
 171         errcode_t err;
 172
 173         JOURNAL_CHECK_TRANS_MAGIC(trans);
 174
 175         if ((trans->flags & J_TRANS_COMMITTED) ||
 176             !(trans->flags & J_TRANS_OPEN))
 177                 return EXT2_ET_INVALID_ARGUMENT;
 178
 179         if (revoke_len == 0)
 180                 return 0;
 181
 182         /* Do we need to leave space at the end for a checksum? */
 183         if (journal_has_csum_v2or3(trans->journal))
 184                 csum_size = sizeof(struct journal_revoke_tail);
 185
 186         curr_blk = trans->block;
 187
 188         bh = getblk(trans->journal->j_dev, curr_blk,
 189                     trans->journal->j_blocksize);
 190         if (bh == NULL)
 191                 return ENOMEM;
 192         jrb = buf = bh->b_data;
 193         jrb->r_header.h_magic = ext2fs_cpu_to_be32(JFS_MAGIC_NUMBER);
 194         jrb->r_header.h_blocktype = ext2fs_cpu_to_be32(JFS_REVOKE_BLOCK);
 195         jrb->r_header.h_sequence = ext2fs_cpu_to_be32(trans->tid);
 196         offset = sizeof(*jrb);
 197
 198         if (jfs_has_feature_64bit(trans->journal))
 199                 sz = 8;
 200         else
 201                 sz = 4;
 202
 203         for (i = 0; i < revoke_len; i++) {
 204                 /* Block full, write to journal */
 205                 if (offset + sz > trans->journal->j_blocksize - csum_size) {
 206                         jrb->r_count = ext2fs_cpu_to_be32(offset);
 207                         jbd2_revoke_csum_set(trans->journal, bh);
 208
 209                         err = journal_bmap(trans->journal, curr_blk,
 210                                            &bh->b_blocknr);
 211                         if (err)
 212                                 goto error;
 213                         dbg_printf("Writing revoke block at %llu:%llu\n",
 214                                    curr_blk, bh->b_blocknr);
 215                         mark_buffer_dirty(bh);
 216                         ll_rw_block(WRITE, 1, &bh);
 217                         err = bh->b_err;
 218                         if (err)
 219                                 goto error;
 220
 221                         offset = sizeof(*jrb);
 222                         curr_blk++;
 223                 }
 224
 225                 if (revoke_list[i] >=
 226                     ext2fs_blocks_count(trans->journal->j_fs_dev->k_fs->super)) {
 227                         err = EXT2_ET_BAD_BLOCK_NUM;
 228                         goto error;
 229                 }
 230
 231                 if (jfs_has_feature_64bit(trans->journal))
 232                         *((__u64 *)(&((char *)buf)[offset])) =
 233                                 ext2fs_cpu_to_be64(revoke_list[i]);
 234                 else
 235                         *((__u32 *)(&((char *)buf)[offset])) =
 236                                 ext2fs_cpu_to_be32(revoke_list[i]);
 237                 offset += sz;
 238         }
 239
 240         if (offset > 0) {
 241                 jrb->r_count = ext2fs_cpu_to_be32(offset);
 242                 jbd2_revoke_csum_set(trans->journal, bh);
 243
 244                 err = journal_bmap(trans->journal, curr_blk, &bh->b_blocknr);
 245                 if (err)
 246                         goto error;
 247                 dbg_printf("Writing revoke block at %llu:%llu\n",
 248                            curr_blk, bh->b_blocknr);
 249                 mark_buffer_dirty(bh);
 250                 ll_rw_block(WRITE, 1, &bh);
 251                 err = bh->b_err;
 252                 if (err)
 253                         goto error;
 254                 curr_blk++;
 255         }
 256
 257 error:
 258         trans->block = curr_blk;
 259         brelse(bh);
 260         return err;
 261 }
 262
 263 static errcode_t journal_add_blocks_to_trans(journal_transaction_t *trans,
 264                                       blk64_t *block_list, size_t block_len,
 265                                       FILE *fp)
 266 {
 267         blk64_t curr_blk, jdb_blk;
 268         size_t i, j;
 269         int csum_size = 0;
 270         journal_header_t *jdb;
 271         journal_block_tag_t *jdbt;
 272         int tag_bytes;
 273         void *buf = NULL, *jdb_buf = NULL;
 274         struct buffer_head *bh = NULL, *data_bh;
 275         errcode_t err;
 276
 277         JOURNAL_CHECK_TRANS_MAGIC(trans);
 278
 279         if ((trans->flags & J_TRANS_COMMITTED) ||
 280             !(trans->flags & J_TRANS_OPEN))
 281                 return EXT2_ET_INVALID_ARGUMENT;
 282
 283         if (block_len == 0)
 284                 return 0;
 285
 286         /* Do we need to leave space at the end for a checksum? */
 287         if (journal_has_csum_v2or3(trans->journal))
 288                 csum_size = sizeof(struct journal_block_tail);
 289
 290         curr_blk = jdb_blk = trans->block;
 291
 292         data_bh = getblk(trans->journal->j_dev, curr_blk,
 293                          trans->journal->j_blocksize);
 294         if (data_bh == NULL)
 295                 return ENOMEM;
 296         buf = data_bh->b_data;
 297
 298         /* write the descriptor block header */
 299         bh = getblk(trans->journal->j_dev, curr_blk,
 300                     trans->journal->j_blocksize);
 301         if (bh == NULL) {
 302                 err = ENOMEM;
 303                 goto error;
 304         }
 305         jdb = jdb_buf = bh->b_data;
 306         jdb->h_magic = ext2fs_cpu_to_be32(JFS_MAGIC_NUMBER);
 307         jdb->h_blocktype = ext2fs_cpu_to_be32(JFS_DESCRIPTOR_BLOCK);
 308         jdb->h_sequence = ext2fs_cpu_to_be32(trans->tid);
 309         jdbt = (journal_block_tag_t *)(jdb + 1);
 310
 311         curr_blk++;
 312         for (i = 0; i < block_len; i++) {
 313                 j = fread(data_bh->b_data, trans->journal->j_blocksize, 1, fp);
 314                 if (j != 1) {
 315                         err = errno;
 316                         goto error;
 317                 }
 318
 319                 tag_bytes = journal_tag_bytes(trans->journal);
 320
 321                 /* No space left in descriptor block, write it out */
 322                 if ((char *)jdbt + tag_bytes >
 323                     (char *)jdb_buf + trans->journal->j_blocksize - csum_size) {
 324                         jbd2_descr_block_csum_set(trans->journal, bh);
 325                         err = journal_bmap(trans->journal, jdb_blk,
 326                                            &bh->b_blocknr);
 327                         if (err)
 328                                 goto error;
 329                         dbg_printf("Writing descriptor block at %llu:%llu\n",
 330                                    jdb_blk, bh->b_blocknr);
 331                         mark_buffer_dirty(bh);
 332                         ll_rw_block(WRITE, 1, &bh);
 333                         err = bh->b_err;
 334                         if (err)
 335                                 goto error;
 336
 337                         jdbt = (journal_block_tag_t *)(jdb + 1);
 338                         jdb_blk = curr_blk;
 339                         curr_blk++;
 340                 }
 341
 342                 if (block_list[i] >=
 343                     ext2fs_blocks_count(trans->journal->j_fs_dev->k_fs->super)) {
 344                         err = EXT2_ET_BAD_BLOCK_NUM;
 345                         goto error;
 346                 }
 347
 348                 /* Fill out the block tag */
 349                 jdbt->t_blocknr = ext2fs_cpu_to_be32(block_list[i] & 0xFFFFFFFF);
 350                 jdbt->t_flags = 0;
 351                 if (jdbt != (journal_block_tag_t *)(jdb + 1))
 352                         jdbt->t_flags |= ext2fs_cpu_to_be16(JFS_FLAG_SAME_UUID);
 353                 else {
 354                         memcpy(jdbt + tag_bytes,
 355                                trans->journal->j_superblock->s_uuid,
 356                                sizeof(trans->journal->j_superblock->s_uuid));
 357                         tag_bytes += 16;
 358                 }
 359                 if (i == block_len - 1)
 360                         jdbt->t_flags |= ext2fs_cpu_to_be16(JFS_FLAG_LAST_TAG);
 361                 if (*((__u32 *)buf) == ext2fs_cpu_to_be32(JFS_MAGIC_NUMBER)) {
 362                         *((__u32 *)buf) = 0;
 363                         jdbt->t_flags |= ext2fs_cpu_to_be16(JFS_FLAG_ESCAPE);
 364                 }
 365                 if (jfs_has_feature_64bit(trans->journal))
 366                         jdbt->t_blocknr_high = ext2fs_cpu_to_be32(block_list[i] >> 32);
 367                 jbd2_block_tag_csum_set(trans->journal, jdbt, data_bh,
 368                                         trans->tid);
 369
 370                 /* Write the data block */
 371                 err = journal_bmap(trans->journal, curr_blk,
 372                                    &data_bh->b_blocknr);
 373                 if (err)
 374                         goto error;
 375                 dbg_printf("Writing data block %llu at %llu:%llu tag %d\n",
 376                            block_list[i], curr_blk, data_bh->b_blocknr,
 377                            tag_bytes);
 378                 mark_buffer_dirty(data_bh);
 379                 ll_rw_block(WRITE, 1, &data_bh);
 380                 err = data_bh->b_err;
 381                 if (err)
 382                         goto error;
 383
 384                 curr_blk++;
 385                 jdbt = (journal_block_tag_t *)(((char *)jdbt) + tag_bytes);
 386         }
 387
 388         /* Write out the last descriptor block */
 389         if (jdbt != (journal_block_tag_t *)(jdb + 1)) {
 390                 jbd2_descr_block_csum_set(trans->journal, bh);
 391                 err = journal_bmap(trans->journal, jdb_blk, &bh->b_blocknr);
 392                 if (err)
 393                         goto error;
 394                 dbg_printf("Writing descriptor block at %llu:%llu\n",
 395                            jdb_blk, bh->b_blocknr);
 396                 mark_buffer_dirty(bh);
 397                 ll_rw_block(WRITE, 1, &bh);
 398                 err = bh->b_err;
 399                 if (err)
 400                         goto error;
 401         }
 402
 403 error:
 404         trans->block = curr_blk;
 405         if (bh)
 406                 brelse(bh);
 407         brelse(data_bh);
 408         return err;
 409 }
 410
 411 static blk64_t journal_guess_blocks(journal_t *journal, blk64_t data_blocks,
 412                                     blk64_t revoke_blocks)
 413 {
 414         blk64_t ret = 1;
 415         unsigned int bs, sz;
 416
 417         /* Estimate # of revoke blocks */
 418         bs = journal->j_blocksize;
 419         if (journal_has_csum_v2or3(journal))
 420                 bs -= sizeof(struct journal_revoke_tail);
 421         sz = jfs_has_feature_64bit(journal) ? sizeof(__u64) : sizeof(__u32);
 422         ret += revoke_blocks * sz / bs;
 423
 424         /* Estimate # of data blocks */
 425         bs = journal->j_blocksize - 16;
 426         if (journal_has_csum_v2or3(journal))
 427                 bs -= sizeof(struct journal_block_tail);
 428         sz = journal_tag_bytes(journal);
 429         ret += data_blocks * sz / bs;
 430
 431         ret += data_blocks;
 432
 433         return ret;
 434 }
 435
 436 static errcode_t journal_open_trans(journal_t *journal,
 437                                     journal_transaction_t *trans,
 438                                     blk64_t blocks)
 439 {
 440         trans->fs = journal->j_fs_dev->k_fs;
 441         trans->journal = journal;
 442         trans->flags = J_TRANS_OPEN;
 443
 444         if (journal->j_tail == 0) {
 445                 /* Clean journal, start at the tail */
 446                 trans->tid = journal->j_tail_sequence;
 447                 trans->start = journal->j_first;
 448         } else {
 449                 /* Put new transaction at the head of the list */
 450                 trans->tid = journal->j_transaction_sequence;
 451                 trans->start = journal->j_head;
 452         }
 453
 454         trans->block = trans->start;
 455         if (trans->start + blocks > journal->j_last)
 456                 return ENOSPC;
 457         trans->end = trans->block + blocks;
 458         journal_dump_trans(trans, "new transaction");
 459
 460         trans->magic = J_TRANS_MAGIC;
 461         return 0;
 462 }
 463
 464 static errcode_t journal_close_trans(journal_transaction_t *trans)
 465 {
 466         journal_t *journal;
 467
 468         JOURNAL_CHECK_TRANS_MAGIC(trans);
 469
 470         if (!(trans->flags & J_TRANS_COMMITTED))
 471                 return 0;
 472
 473         journal = trans->journal;
 474         if (journal->j_tail == 0) {
 475                 /* Update the tail */
 476                 journal->j_tail_sequence = trans->tid;
 477                 journal->j_tail = trans->start;
 478                 journal->j_superblock->s_start = ext2fs_cpu_to_be32(trans->start);
 479         }
 480
 481         /* Update the head */
 482         journal->j_head = trans->end + 1;
 483         journal->j_transaction_sequence = trans->tid + 1;
 484
 485         trans->magic = 0;
 486
 487         /* Mark ourselves as needing recovery */
 488         if (!ext2fs_has_feature_journal_needs_recovery(trans->fs->super)) {
 489                 ext2fs_set_feature_journal_needs_recovery(trans->fs->super);
 490                 ext2fs_mark_super_dirty(trans->fs);
 491         }
 492
 493         return 0;
 494 }
 495
 496 #define JOURNAL_WRITE_NO_COMMIT         1
 497 static errcode_t journal_write(journal_t *journal,
 498                                int flags, blk64_t *block_list,
 499                                size_t block_len, blk64_t *revoke_list,
 500                                size_t revoke_len, FILE *fp)
 501 {
 502         blk64_t blocks;
 503         journal_transaction_t trans;
 504         errcode_t err;
 505
 506         if (revoke_len > 0) {
 507                 jfs_set_feature_revoke(journal);
 508                 mark_buffer_dirty(journal->j_sb_buffer);
 509         }
 510
 511         blocks = journal_guess_blocks(journal, block_len, revoke_len);
 512         err = journal_open_trans(journal, &trans, blocks);
 513         if (err)
 514                 goto error;
 515
 516         err = journal_add_blocks_to_trans(&trans, block_list, block_len, fp);
 517         if (err)
 518                 goto error;
 519
 520         err = journal_add_revoke_to_trans(&trans, revoke_list, revoke_len);
 521         if (err)
 522                 goto error;
 523
 524         if (!(flags & JOURNAL_WRITE_NO_COMMIT)) {
 525                 err = journal_commit_trans(&trans);
 526                 if (err)
 527                         goto error;
 528         }
 529
 530         err = journal_close_trans(&trans);
 531         if (err)
 532                 goto error;
 533 error:
 534         return err;
 535 }
 536
 537 void do_journal_write(int argc, char *argv[], int sci_idx EXT2FS_ATTR((unused)),
 538                       void *infop EXT2FS_ATTR((unused)))
 539 {
 540         blk64_t *blist = NULL, *rlist = NULL;
 541         size_t bn = 0, rn = 0;
 542         FILE *fp = NULL;
 543         int opt;
 544         int flags = 0;
 545         errcode_t err;
 546
 547         if (current_journal == NULL) {
 548                 printf("Journal not open.\n");
 549                 return;
 550         }
 551
 552         reset_getopt();
 553         while ((opt = getopt(argc, argv, "b:r:c")) != -1) {
 554                 switch (opt) {
 555                 case 'b':
 556                         err = read_list(optarg, &blist, &bn);
 557                         if (err)
 558                                 com_err(argv[0], err,
 559                                         "while reading block list");
 560                         break;
 561                 case 'r':
 562                         err = read_list(optarg, &rlist, &rn);
 563                         if (err)
 564                                 com_err(argv[0], err,
 565                                         "while reading revoke list");
 566                         break;
 567                 case 'c':
 568                         flags |= JOURNAL_WRITE_NO_COMMIT;
 569                         break;
 570                 default:
 571                         printf("%s [-b blocks] [-r revoke] [-c] file\n",
 572                                argv[0]);
 573                         printf("-b: Write these blocks into transaction.\n");
 574                         printf("-c: Do not commit transaction.\n");
 575                         printf("-r: Revoke these blocks from transaction.\n");
 576
 577                         goto out;
 578                 }
 579         }
 580
 581         if (bn > 0 && optind != argc - 1) {
 582                 printf("Need a file to read blocks from.\n");
 583                 return;
 584         }
 585
 586         if (bn > 0) {
 587                 fp = fopen(argv[optind], "r");
 588                 if (fp == NULL) {
 589                         com_err(argv[0], errno,
 590                                 "while opening journal data file");
 591                         goto out;
 592                 }
 593         }
 594
 595         err = journal_write(current_journal, flags, blist, bn,
 596                             rlist, rn, fp);
 597         if (err)
 598                 com_err("journal_write", err, "while writing journal");
 599
 600         if (fp)
 601                 fclose(fp);
 602 out:
 603         if (blist)
 604                 free(blist);
 605         if (rlist)
 606                 free(rlist);
 607 }
 608
 609 /* Make sure we wrap around the log correctly! */
 610 #define wrap(journal, var)                                              \
 611 do {                                                                    \
 612         if (var >= (journal)->j_last)                                   \
 613                 var -= ((journal)->j_last - (journal)->j_first);        \
 614 } while (0)
 615
 616 /*
 617  * Count the number of in-use tags in a journal descriptor block.
 618  */
 619
 620 static int count_tags(journal_t *journal, char *buf)
 621 {
 622         char                    *tagp;
 623         journal_block_tag_t     *tag;
 624         int                     nr = 0, size = journal->j_blocksize;
 625         int                     tag_bytes = journal_tag_bytes(journal);
 626
 627         if (journal_has_csum_v2or3(journal))
 628                 size -= sizeof(struct journal_block_tail);
 629
 630         tagp = buf + sizeof(journal_header_t);
 631
 632         while ((tagp - buf + tag_bytes) <= size) {
 633                 tag = (journal_block_tag_t *) tagp;
 634
 635                 nr++;
 636                 tagp += tag_bytes;
 637                 if (!(tag->t_flags & ext2fs_cpu_to_be16(JFS_FLAG_SAME_UUID)))
 638                         tagp += 16;
 639
 640                 if (tag->t_flags & ext2fs_cpu_to_be16(JFS_FLAG_LAST_TAG))
 641                         break;
 642         }
 643
 644         return nr;
 645 }
 646
 647 static errcode_t journal_find_head(journal_t *journal)
 648 {
 649         unsigned int            next_commit_ID;
 650         blk64_t                 next_log_block, head_block;
 651         int                     err;
 652         journal_superblock_t    *sb;
 653         journal_header_t        *tmp;
 654         struct buffer_head      *bh;
 655         unsigned int            sequence;
 656         int                     blocktype;
 657
 658         /*
 659          * First thing is to establish what we expect to find in the log
 660          * (in terms of transaction IDs), and where (in terms of log
 661          * block offsets): query the superblock.
 662          */
 663
 664         sb = journal->j_superblock;
 665         next_commit_ID = ext2fs_be32_to_cpu(sb->s_sequence);
 666         next_log_block = ext2fs_be32_to_cpu(sb->s_start);
 667         head_block = next_log_block;
 668
 669         if (next_log_block == 0)
 670                 return 0;
 671
 672         bh = getblk(journal->j_dev, 0, journal->j_blocksize);
 673         if (bh == NULL)
 674                 return ENOMEM;
 675
 676         /*
 677          * Now we walk through the log, transaction by transaction,
 678          * making sure that each transaction has a commit block in the
 679          * expected place.  Each complete transaction gets replayed back
 680          * into the main filesystem.
 681          */
 682         while (1) {
 683                 dbg_printf("Scanning for sequence ID %u at %lu/%lu\n",
 684                           next_commit_ID, (unsigned long)next_log_block,
 685                           journal->j_last);
 686
 687                 /* Skip over each chunk of the transaction looking
 688                  * either the next descriptor block or the final commit
 689                  * record. */
 690                 err = journal_bmap(journal, next_log_block, &bh->b_blocknr);
 691                 if (err)
 692                         goto err;
 693                 mark_buffer_uptodate(bh, 0);
 694                 ll_rw_block(READ, 1, &bh);
 695                 err = bh->b_err;
 696                 if (err)
 697                         goto err;
 698
 699                 next_log_block++;
 700                 wrap(journal, next_log_block);
 701
 702                 /* What kind of buffer is it?
 703                  *
 704                  * If it is a descriptor block, check that it has the
 705                  * expected sequence number.  Otherwise, we're all done
 706                  * here. */
 707
 708                 tmp = (journal_header_t *)bh->b_data;
 709
 710                 if (tmp->h_magic != ext2fs_cpu_to_be32(JFS_MAGIC_NUMBER)) {
 711                         dbg_printf("JBD2: wrong magic 0x%x\n", tmp->h_magic);
 712                         goto err;
 713                 }
 714
 715                 blocktype = ext2fs_be32_to_cpu(tmp->h_blocktype);
 716                 sequence = ext2fs_be32_to_cpu(tmp->h_sequence);
 717                 dbg_printf("Found magic %d, sequence %d\n",
 718                           blocktype, sequence);
 719
 720                 if (sequence != next_commit_ID) {
 721                         dbg_printf("JBD2: Wrong sequence %d (wanted %d)\n",
 722                                    sequence, next_commit_ID);
 723                         goto err;
 724                 }
 725
 726                 /* OK, we have a valid descriptor block which matches
 727                  * all of the sequence number checks.  What are we going
 728                  * to do with it?  That depends on the pass... */
 729
 730                 switch (blocktype) {
 731                 case JFS_DESCRIPTOR_BLOCK:
 732                         next_log_block += count_tags(journal, bh->b_data);
 733                         wrap(journal, next_log_block);
 734                         continue;
 735
 736                 case JFS_COMMIT_BLOCK:
 737                         head_block = next_log_block;
 738                         next_commit_ID++;
 739                         continue;
 740
 741                 case JFS_REVOKE_BLOCK:
 742                         continue;
 743
 744                 default:
 745                         dbg_printf("Unrecognised magic %d, end of scan.\n",
 746                                   blocktype);
 747                         err = -EINVAL;
 748                         goto err;
 749                 }
 750         }
 751
 752 err:
 753         if (err == 0) {
 754                 dbg_printf("head seq=%d blk=%llu\n", next_commit_ID,
 755                            head_block);
 756                 journal->j_transaction_sequence = next_commit_ID;
 757                 journal->j_head = head_block;
 758         }
 759         brelse(bh);
 760         return err;
 761 }
 762
 763 static void update_journal_csum(journal_t *journal, int ver)
 764 {
 765         journal_superblock_t *jsb;
 766
 767         if (journal->j_format_version < 2)
 768                 return;
 769
 770         if (journal->j_tail != 0 ||
 771             ext2fs_has_feature_journal_needs_recovery(
 772                                         journal->j_fs_dev->k_fs->super)) {
 773                 printf("Journal needs recovery, will not add csums.\n");
 774                 return;
 775         }
 776
 777         /* metadata_csum implies journal csum v3 */
 778         jsb = journal->j_superblock;
 779         if (ext2fs_has_feature_metadata_csum(journal->j_fs_dev->k_fs->super)) {
 780                 printf("Setting csum v%d\n", ver);
 781                 switch (ver) {
 782                 case 2:
 783                         jfs_clear_feature_csum3(journal);
 784                         jfs_set_feature_csum2(journal);
 785                         jfs_clear_feature_checksum(journal);
 786                         break;
 787                 case 3:
 788                         jfs_set_feature_csum3(journal);
 789                         jfs_clear_feature_csum2(journal);
 790                         jfs_clear_feature_checksum(journal);
 791                         break;
 792                 default:
 793                         printf("Unknown checksum v%d\n", ver);
 794                         break;
 795                 }
 796                 journal->j_superblock->s_checksum_type = JBD2_CRC32C_CHKSUM;
 797                 journal->j_csum_seed = jbd2_chksum(journal, ~0, jsb->s_uuid,
 798                                                    sizeof(jsb->s_uuid));
 799         } else {
 800                 jfs_clear_feature_csum3(journal);
 801                 jfs_clear_feature_csum2(journal);
 802                 jfs_set_feature_checksum(journal);
 803         }
 804 }
 805
 806 static void update_uuid(journal_t *journal)
 807 {
 808         size_t z;
 809         ext2_filsys fs;
 810
 811         if (journal->j_format_version < 2)
 812                 return;
 813
 814         for (z = 0; z < sizeof(journal->j_superblock->s_uuid); z++)
 815                 if (journal->j_superblock->s_uuid[z])
 816                         break;
 817         if (z == 0)
 818                 return;
 819
 820         fs = journal->j_fs_dev->k_fs;
 821         if (!ext2fs_has_feature_64bit(fs->super))
 822                 return;
 823
 824         if (jfs_has_feature_64bit(journal) &&
 825             ext2fs_has_feature_64bit(fs->super))
 826                 return;
 827
 828         if (journal->j_tail != 0 ||
 829             ext2fs_has_feature_journal_needs_recovery(fs->super)) {
 830                 printf("Journal needs recovery, will not set 64bit.\n");
 831                 return;
 832         }
 833
 834         memcpy(journal->j_superblock->s_uuid, fs->super->s_uuid,
 835                sizeof(fs->super->s_uuid));
 836 }
 837
 838 static void update_64bit_flag(journal_t *journal)
 839 {
 840         if (journal->j_format_version < 2)
 841                 return;
 842
 843         if (!ext2fs_has_feature_64bit(journal->j_fs_dev->k_fs->super))
 844                 return;
 845
 846         if (jfs_has_feature_64bit(journal) &&
 847             ext2fs_has_feature_64bit(journal->j_fs_dev->k_fs->super))
 848                 return;
 849
 850         if (journal->j_tail != 0 ||
 851             ext2fs_has_feature_journal_needs_recovery(
 852                                 journal->j_fs_dev->k_fs->super)) {
 853                 printf("Journal needs recovery, will not set 64bit.\n");
 854                 return;
 855         }
 856
 857         jfs_set_feature_64bit(journal);
 858 }
 859
 860 void do_journal_open(int argc, char *argv[], int sci_idx EXT2FS_ATTR((unused)),
 861                      void *infop EXT2FS_ATTR((unused)))
 862 {
 863         int opt, enable_csum = 0, csum_ver = 3;
 864         journal_t *journal;
 865         errcode_t err;
 866
 867         if (check_fs_open(argv[0]))
 868                 return;
 869         if (check_fs_read_write(argv[0]))
 870                 return;
 871         if (check_fs_bitmaps(argv[0]))
 872                 return;
 873         if (current_journal) {
 874                 printf("Journal is already open.\n");
 875                 return;
 876         }
 877         if (!ext2fs_has_feature_journal(current_fs->super)) {
 878                 printf("Journalling is not enabled on this filesystem.\n");
 879                 return;
 880         }
 881
 882         reset_getopt();
 883         while ((opt = getopt(argc, argv, "cv:f:")) != -1) {
 884                 switch (opt) {
 885                 case 'c':
 886                         enable_csum = 1;
 887                         break;
 888                 case 'f':
 889                         if (current_fs->journal_name)
 890                                 free(current_fs->journal_name);
 891                         current_fs->journal_name = strdup(optarg);
 892                         break;
 893                 case 'v':
 894                         csum_ver = atoi(optarg);
 895                         if (csum_ver != 2 && csum_ver != 3) {
 896                                 printf("Unknown journal csum v%d\n", csum_ver);
 897                                 csum_ver = 3;
 898                         }
 899                         break;
 900                 default:
 901                         printf("%s: [-c] [-v ver] [-f ext_jnl]\n", argv[0]);
 902                         printf("-c: Enable journal checksumming.\n");
 903                         printf("-v: Use this version checksum format.\n");
 904                         printf("-f: Load this external journal.\n");
 905                 }
 906         }
 907
 908         err = ext2fs_open_journal(current_fs, &current_journal);
 909         if (err) {
 910                 com_err(argv[0], err, "while opening journal");
 911                 return;
 912         }
 913         journal = current_journal;
 914
 915         dbg_printf("JOURNAL: seq=%d tailseq=%d start=%lu first=%lu "
 916                    "maxlen=%lu\n", journal->j_tail_sequence,
 917                    journal->j_transaction_sequence, journal->j_tail,
 918                    journal->j_first, journal->j_last);
 919
 920         update_uuid(journal);
 921         update_64bit_flag(journal);
 922         if (enable_csum)
 923                 update_journal_csum(journal, csum_ver);
 924
 925         err = journal_find_head(journal);
 926         if (err)
 927                 com_err(argv[0], err, "while examining journal");
 928 }
 929
 930 void do_journal_close(int argc EXT2FS_ATTR((unused)),
 931                       char *argv[] EXT2FS_ATTR((unused)),
 932                       int sci_idx EXT2FS_ATTR((unused)),
 933                       void *infop EXT2FS_ATTR((unused)))
 934 {
 935         if (current_journal == NULL) {
 936                 printf("Journal not open.\n");
 937                 return;
 938         }
 939
 940         ext2fs_close_journal(current_fs, &current_journal);
 941 }
 942
 943 void do_journal_run(int argc EXT2FS_ATTR((unused)), char *argv[],
 944                     int sci_idx EXT2FS_ATTR((unused)),
 945                     void *infop EXT2FS_ATTR((unused)))
 946 {
 947         errcode_t err;
 948
 949         if (check_fs_open(argv[0]))
 950                 return;
 951         if (check_fs_read_write(argv[0]))
 952                 return;
 953         if (check_fs_bitmaps(argv[0]))
 954                 return;
 955         if (current_journal) {
 956                 printf("Please close the journal before recovering it.\n");
 957                 return;
 958         }
 959
 960         err = ext2fs_run_ext3_journal(&current_fs);
 961         if (err)
 962                 com_err("journal_run", err, "while recovering journal");
 963         else {
 964                 ext2fs_clear_feature_journal_needs_recovery(current_fs->super);
 965                 ext2fs_mark_super_dirty(current_fs);
 966         }
 967 }