lwext4/ext4_journal.c

   1 /*
   2  * Copyright (c) 2015 Grzegorz Kostka (kostka.grzegorz@gmail.com)
   3  * Copyright (c) 2015 Kaho Ng (ngkaho1234@gmail.com)
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * - Redistributions of source code must retain the above copyright
  11  *   notice, this list of conditions and the following disclaimer.
  12  * - Redistributions in binary form must reproduce the above copyright
  13  *   notice, this list of conditions and the following disclaimer in the
  14  *   documentation and/or other materials provided with the distribution.
  15  * - The name of the author may not be used to endorse or promote products
  16  *   derived from this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  */
  29
  30 /** @addtogroup lwext4
  31  * @{
  32  */
  33 /**
  34  * @file  ext4_journal.c
  35  * @brief Journal handle functions
  36  */
  37
  38 #include "ext4_config.h"
  39 #include "ext4_types.h"
  40 #include "ext4_fs.h"
  41 #include "ext4_super.h"
  42 #include "ext4_journal.h"
  43 #include "ext4_errno.h"
  44 #include "ext4_blockdev.h"
  45 #include "ext4_crc32c.h"
  46 #include "ext4_debug.h"
  47 #include "tree.h"
  48
  49 #include <string.h>
  50 #include <stdlib.h>
  51
  52 /**@brief  Revoke entry during journal replay.*/
  53 struct revoke_entry {
  54         /**@brief  Block number not to be replayed.*/
  55         ext4_fsblk_t block;
  56
  57         /**@brief  For any transaction id smaller
  58          *         than trans_id, records of @block
  59          *         in those transactions should not
  60          *         be replayed.*/
  61         uint32_t trans_id;
  62
  63         /**@brief  Revoke tree node.*/
  64         RB_ENTRY(revoke_entry) revoke_node;
  65 };
  66
  67 /**@brief  Valid journal replay information.*/
  68 struct recover_info {
  69         /**@brief  Starting transaction id.*/
  70         uint32_t start_trans_id;
  71
  72         /**@brief  Ending transaction id.*/
  73         uint32_t last_trans_id;
  74
  75         /**@brief  Used as internal argument.*/
  76         uint32_t this_trans_id;
  77
  78         /**@brief  RB-Tree storing revoke entries.*/
  79         RB_HEAD(jbd_revoke, revoke_entry) revoke_root;
  80 };
  81
  82 /**@brief  Journal replay internal arguments.*/
  83 struct replay_arg {
  84         /**@brief  Journal replay information.*/
  85         struct recover_info *info;
  86
  87         /**@brief  Current block we are on.*/
  88         uint32_t *this_block;
  89
  90         /**@brief  Current trans_id we are on.*/
  91         uint32_t this_trans_id;
  92 };
  93
  94 static int
  95 jbd_revoke_entry_cmp(struct revoke_entry *a, struct revoke_entry *b)
  96 {
  97         if (a->block > b->block)
  98                 return 1;
  99         else if (a->block < b->block)
 100                 return -1;
 101         return 0;
 102 }
 103
 104 RB_GENERATE_INTERNAL(jbd_revoke, revoke_entry, revoke_node,
 105                      jbd_revoke_entry_cmp, static inline)
 106
 107 #define jbd_alloc_revoke_entry() calloc(1, sizeof(struct revoke_entry))
 108 #define jbd_free_revoke_entry(addr) free(addr)
 109
 110 /**@brief  Data block lookup helper.*/
 111 int jbd_inode_bmap(struct jbd_fs *jbd_fs,
 112                    ext4_lblk_t iblock,
 113                    ext4_fsblk_t *fblock);
 114
 115 /**@brief  Write jbd superblock to disk.
 116  * @param  jbd_fs jbd filesystem
 117  * @param  s jbd superblock
 118  * @return standard error code*/
 119 int jbd_sb_write(struct jbd_fs *jbd_fs, struct jbd_sb *s)
 120 {
 121         int rc;
 122         struct ext4_fs *fs = jbd_fs->inode_ref.fs;
 123         uint64_t offset;
 124         ext4_fsblk_t fblock;
 125         rc = jbd_inode_bmap(jbd_fs, 0, &fblock);
 126         if (rc != EOK)
 127                 return rc;
 128
 129         offset = fblock * ext4_sb_get_block_size(&fs->sb);
 130         return ext4_block_writebytes(fs->bdev, offset, s,
 131                                      EXT4_SUPERBLOCK_SIZE);
 132 }
 133
 134 /**@brief  Read jbd superblock from disk.
 135  * @param  jbd_fs jbd filesystem
 136  * @param  s jbd superblock
 137  * @return standard error code*/
 138 int jbd_sb_read(struct jbd_fs *jbd_fs, struct jbd_sb *s)
 139 {
 140         int rc;
 141         struct ext4_fs *fs = jbd_fs->inode_ref.fs;
 142         uint64_t offset;
 143         ext4_fsblk_t fblock;
 144         rc = jbd_inode_bmap(jbd_fs, 0, &fblock);
 145         if (rc != EOK)
 146                 return rc;
 147
 148         offset = fblock * ext4_sb_get_block_size(&fs->sb);
 149         return ext4_block_readbytes(fs->bdev, offset, s,
 150                                     EXT4_SUPERBLOCK_SIZE);
 151 }
 152
 153 /**@brief  Verify jbd superblock.
 154  * @param  sb jbd superblock
 155  * @return true if jbd superblock is valid */
 156 static bool jbd_verify_sb(struct jbd_sb *sb)
 157 {
 158         struct jbd_bhdr *header = &sb->header;
 159         if (jbd_get32(header, magic) != JBD_MAGIC_NUMBER)
 160                 return false;
 161
 162         if (jbd_get32(header, blocktype) != JBD_SUPERBLOCK &&
 163             jbd_get32(header, blocktype) != JBD_SUPERBLOCK_V2)
 164                 return false;
 165
 166         return true;
 167 }
 168
 169 /**@brief  Write back dirty jbd superblock to disk.
 170  * @param  jbd_fs jbd filesystem
 171  * @return standard error code*/
 172 static int jbd_write_sb(struct jbd_fs *jbd_fs)
 173 {
 174         int rc = EOK;
 175         if (jbd_fs->dirty) {
 176                 rc = jbd_sb_write(jbd_fs, &jbd_fs->sb);
 177                 if (rc != EOK)
 178                         return rc;
 179
 180                 jbd_fs->dirty = false;
 181         }
 182         return rc;
 183 }
 184
 185 /**@brief  Get reference to jbd filesystem.
 186  * @param  fs Filesystem to load journal of
 187  * @param  jbd_fs jbd filesystem
 188  * @return standard error code*/
 189 int jbd_get_fs(struct ext4_fs *fs,
 190                struct jbd_fs *jbd_fs)
 191 {
 192         int rc;
 193         uint32_t journal_ino;
 194
 195         memset(jbd_fs, 0, sizeof(struct jbd_fs));
 196         /* See if there is journal inode on this filesystem.*/
 197         /* FIXME: detection on existance ofbkejournal bdev is
 198          *        missing.*/
 199         journal_ino = ext4_get32(&fs->sb, journal_inode_number);
 200
 201         rc = ext4_fs_get_inode_ref(fs,
 202                                    journal_ino,
 203                                    &jbd_fs->inode_ref);
 204         if (rc != EOK) {
 205                 memset(jbd_fs, 0, sizeof(struct jbd_fs));
 206                 return rc;
 207         }
 208         rc = jbd_sb_read(jbd_fs, &jbd_fs->sb);
 209         if (rc != EOK) {
 210                 memset(jbd_fs, 0, sizeof(struct jbd_fs));
 211                 ext4_fs_put_inode_ref(&jbd_fs->inode_ref);
 212                 return rc;
 213         }
 214         if (!jbd_verify_sb(&jbd_fs->sb)) {
 215                 memset(jbd_fs, 0, sizeof(struct jbd_fs));
 216                 ext4_fs_put_inode_ref(&jbd_fs->inode_ref);
 217                 rc = EIO;
 218         }
 219
 220         return rc;
 221 }
 222
 223 /**@brief  Put reference of jbd filesystem.
 224  * @param  jbd_fs jbd filesystem
 225  * @return standard error code*/
 226 int jbd_put_fs(struct jbd_fs *jbd_fs)
 227 {
 228         int rc = EOK;
 229         rc = jbd_write_sb(jbd_fs);
 230
 231         ext4_fs_put_inode_ref(&jbd_fs->inode_ref);
 232         return rc;
 233 }
 234
 235 /**@brief  Data block lookup helper.
 236  * @param  jbd_fs jbd filesystem
 237  * @param  iblock block index
 238  * @param  fblock logical block address
 239  * @return standard error code*/
 240 int jbd_inode_bmap(struct jbd_fs *jbd_fs,
 241                    ext4_lblk_t iblock,
 242                    ext4_fsblk_t *fblock)
 243 {
 244         int rc = ext4_fs_get_inode_dblk_idx(
 245                         &jbd_fs->inode_ref,
 246                         iblock,
 247                         fblock,
 248                         false);
 249         return rc;
 250 }
 251
 252 /**@brief   jbd block get function (through cache).
 253  * @param   jbd_fs jbd filesystem
 254  * @param   block block descriptor
 255  * @param   fblock jbd logical block address
 256  * @return  standard error code*/
 257 int jbd_block_get(struct jbd_fs *jbd_fs,
 258                   struct ext4_block *block,
 259                   ext4_fsblk_t fblock)
 260 {
 261         /* TODO: journal device. */
 262         int rc;
 263         ext4_lblk_t iblock = (ext4_lblk_t)fblock;
 264
 265         /* Lookup the logical block address of
 266          * fblock.*/
 267         rc = jbd_inode_bmap(jbd_fs, iblock,
 268                             &fblock);
 269         if (rc != EOK)
 270                 return rc;
 271
 272         struct ext4_blockdev *bdev = jbd_fs->inode_ref.fs->bdev;
 273         rc = ext4_block_get(bdev, block, fblock);
 274
 275         /* If succeeded, mark buffer as BC_FLUSH to indicate
 276          * that data should be written to disk immediately.*/
 277         if (rc == EOK)
 278                 ext4_bcache_set_flag(block->buf, BC_FLUSH);
 279
 280         return rc;
 281 }
 282
 283 /**@brief   jbd block get function (through cache, don't read).
 284  * @param   jbd_fs jbd filesystem
 285  * @param   block block descriptor
 286  * @param   fblock jbd logical block address
 287  * @return  standard error code*/
 288 int jbd_block_get_noread(struct jbd_fs *jbd_fs,
 289                          struct ext4_block *block,
 290                          ext4_fsblk_t fblock)
 291 {
 292         /* TODO: journal device. */
 293         int rc;
 294         ext4_lblk_t iblock = (ext4_lblk_t)fblock;
 295         rc = jbd_inode_bmap(jbd_fs, iblock,
 296                             &fblock);
 297         if (rc != EOK)
 298                 return rc;
 299
 300         struct ext4_blockdev *bdev = jbd_fs->inode_ref.fs->bdev;
 301         rc = ext4_block_get_noread(bdev, block, fblock);
 302         if (rc == EOK)
 303                 ext4_bcache_set_flag(block->buf, BC_FLUSH);
 304
 305         return rc;
 306 }
 307
 308 /**@brief   jbd block set procedure (through cache).
 309  * @param   jbd_fs jbd filesystem
 310  * @param   block block descriptor
 311  * @return  standard error code*/
 312 int jbd_block_set(struct jbd_fs *jbd_fs,
 313                   struct ext4_block *block)
 314 {
 315         return ext4_block_set(jbd_fs->inode_ref.fs->bdev,
 316                               block);
 317 }
 318
 319 /**@brief  helper functions to calculate
 320  *         block tag size, not including UUID part.
 321  * @param  jbd_fs jbd filesystem
 322  * @return tag size in bytes*/
 323 int jbd_tag_bytes(struct jbd_fs *jbd_fs)
 324 {
 325         int size;
 326
 327         /* It is very easy to deal with the case which
 328          * JBD_FEATURE_INCOMPAT_CSUM_V3 is enabled.*/
 329         if (JBD_HAS_INCOMPAT_FEATURE(&jbd_fs->sb,
 330                                      JBD_FEATURE_INCOMPAT_CSUM_V3))
 331                 return sizeof(struct jbd_block_tag3);
 332
 333         size = sizeof(struct jbd_block_tag);
 334
 335         /* If JBD_FEATURE_INCOMPAT_CSUM_V2 is enabled,
 336          * add 2 bytes to size.*/
 337         if (JBD_HAS_INCOMPAT_FEATURE(&jbd_fs->sb,
 338                                      JBD_FEATURE_INCOMPAT_CSUM_V2))
 339                 size += sizeof(uint16_t);
 340
 341         if (JBD_HAS_INCOMPAT_FEATURE(&jbd_fs->sb,
 342                                      JBD_FEATURE_INCOMPAT_64BIT))
 343                 return size;
 344
 345         /* If block number is 4 bytes in size,
 346          * minus 4 bytes from size */
 347         return size - sizeof(uint32_t);
 348 }
 349
 350 /**@brief  Tag information. */
 351 struct tag_info {
 352         /**@brief  Tag size in bytes, including UUID part.*/
 353         int tag_bytes;
 354
 355         /**@brief  block number stored in this tag.*/
 356         ext4_fsblk_t block;
 357
 358         /**@brief  whether UUID part exists or not.*/
 359         bool uuid_exist;
 360
 361         /**@brief  UUID content if UUID part exists.*/
 362         uint8_t uuid[UUID_SIZE];
 363
 364         /**@brief  Is this the last tag? */
 365         bool last_tag;
 366 };
 367
 368 /**@brief  Extract information from a block tag.
 369  * @param  __tag pointer to the block tag
 370  * @param  tag_bytes block tag size of this jbd filesystem
 371  * @param  remaining size in buffer containing the block tag
 372  * @param  tag_info information of this tag.
 373  * @return  EOK when succeed, otherwise return EINVAL.*/
 374 static int
 375 jbd_extract_block_tag(struct jbd_fs *jbd_fs,
 376                       void *__tag,
 377                       int tag_bytes,
 378                       int32_t remain_buf_size,
 379                       struct tag_info *tag_info)
 380 {
 381         char *uuid_start;
 382         tag_info->tag_bytes = tag_bytes;
 383         tag_info->uuid_exist = false;
 384         tag_info->last_tag = false;
 385
 386         /* See whether it is possible to hold a valid block tag.*/
 387         if (remain_buf_size - tag_bytes < 0)
 388                 return EINVAL;
 389
 390         if (JBD_HAS_INCOMPAT_FEATURE(&jbd_fs->sb,
 391                                      JBD_FEATURE_INCOMPAT_CSUM_V3)) {
 392                 struct jbd_block_tag3 *tag = __tag;
 393                 tag_info->block = jbd_get32(tag, blocknr);
 394                 if (JBD_HAS_INCOMPAT_FEATURE(&jbd_fs->sb,
 395                                              JBD_FEATURE_INCOMPAT_64BIT))
 396                          tag_info->block |=
 397                                  (uint64_t)jbd_get32(tag, blocknr_high) << 32;
 398
 399                 if (jbd_get32(tag, flags) & JBD_FLAG_ESCAPE)
 400                         tag_info->block = 0;
 401
 402                 if (!(jbd_get32(tag, flags) & JBD_FLAG_SAME_UUID)) {
 403                         /* See whether it is possible to hold UUID part.*/
 404                         if (remain_buf_size - tag_bytes < UUID_SIZE)
 405                                 return EINVAL;
 406
 407                         uuid_start = (char *)tag + tag_bytes;
 408                         tag_info->uuid_exist = true;
 409                         tag_info->tag_bytes += UUID_SIZE;
 410                         memcpy(tag_info->uuid, uuid_start, UUID_SIZE);
 411                 }
 412
 413                 if (jbd_get32(tag, flags) & JBD_FLAG_LAST_TAG)
 414                         tag_info->last_tag = true;
 415
 416         } else {
 417                 struct jbd_block_tag *tag = __tag;
 418                 tag_info->block = jbd_get32(tag, blocknr);
 419                 if (JBD_HAS_INCOMPAT_FEATURE(&jbd_fs->sb,
 420                                              JBD_FEATURE_INCOMPAT_64BIT))
 421                          tag_info->block |=
 422                                  (uint64_t)jbd_get32(tag, blocknr_high) << 32;
 423
 424                 if (jbd_get16(tag, flags) & JBD_FLAG_ESCAPE)
 425                         tag_info->block = 0;
 426
 427                 if (!(jbd_get16(tag, flags) & JBD_FLAG_SAME_UUID)) {
 428                         /* See whether it is possible to hold UUID part.*/
 429                         if (remain_buf_size - tag_bytes < UUID_SIZE)
 430                                 return EINVAL;
 431
 432                         uuid_start = (char *)tag + tag_bytes;
 433                         tag_info->uuid_exist = true;
 434                         tag_info->tag_bytes += UUID_SIZE;
 435                         memcpy(tag_info->uuid, uuid_start, UUID_SIZE);
 436                 }
 437
 438                 if (jbd_get16(tag, flags) & JBD_FLAG_LAST_TAG)
 439                         tag_info->last_tag = true;
 440
 441         }
 442         return EOK;
 443 }
 444
 445 /**@brief  Write information to a block tag.
 446  * @param  __tag pointer to the block tag
 447  * @param  remaining size in buffer containing the block tag
 448  * @param  tag_info information of this tag.
 449  * @return  EOK when succeed, otherwise return EINVAL.*/
 450 static int
 451 jbd_write_block_tag(struct jbd_fs *jbd_fs,
 452                     void *__tag,
 453                     int32_t remain_buf_size,
 454                     struct tag_info *tag_info)
 455 {
 456         char *uuid_start;
 457         int tag_bytes = jbd_tag_bytes(jbd_fs);
 458
 459         tag_info->tag_bytes = tag_bytes;
 460
 461         /* See whether it is possible to hold a valid block tag.*/
 462         if (remain_buf_size - tag_bytes < 0)
 463                 return EINVAL;
 464
 465         if (JBD_HAS_INCOMPAT_FEATURE(&jbd_fs->sb,
 466                                      JBD_FEATURE_INCOMPAT_CSUM_V3)) {
 467                 struct jbd_block_tag3 *tag = __tag;
 468                 jbd_set32(tag, blocknr, tag_info->block);
 469                 if (JBD_HAS_INCOMPAT_FEATURE(&jbd_fs->sb,
 470                                              JBD_FEATURE_INCOMPAT_64BIT))
 471                         jbd_set32(tag, blocknr_high, tag_info->block >> 32);
 472
 473                 if (tag_info->uuid_exist) {
 474                         /* See whether it is possible to hold UUID part.*/
 475                         if (remain_buf_size - tag_bytes < UUID_SIZE)
 476                                 return EINVAL;
 477
 478                         uuid_start = (char *)tag + tag_bytes;
 479                         tag_info->tag_bytes += UUID_SIZE;
 480                         memcpy(uuid_start, tag_info->uuid, UUID_SIZE);
 481                 } else
 482                         jbd_set32(tag, flags,
 483                                   jbd_get32(tag, flags) | JBD_FLAG_SAME_UUID);
 484
 485                 if (tag_info->last_tag)
 486                         jbd_set32(tag, flags,
 487                                   jbd_get32(tag, flags) | JBD_FLAG_LAST_TAG);
 488
 489         } else {
 490                 struct jbd_block_tag *tag = __tag;
 491                 jbd_set32(tag, blocknr, tag_info->block);
 492                 if (JBD_HAS_INCOMPAT_FEATURE(&jbd_fs->sb,
 493                                              JBD_FEATURE_INCOMPAT_64BIT))
 494                         jbd_set32(tag, blocknr_high, tag_info->block >> 32);
 495
 496                 if (tag_info->uuid_exist) {
 497                         /* See whether it is possible to hold UUID part.*/
 498                         if (remain_buf_size - tag_bytes < UUID_SIZE)
 499                                 return EINVAL;
 500
 501                         uuid_start = (char *)tag + tag_bytes;
 502                         tag_info->tag_bytes += UUID_SIZE;
 503                         memcpy(uuid_start, tag_info->uuid, UUID_SIZE);
 504                 } else
 505                         jbd_set16(tag, flags,
 506                                   jbd_get16(tag, flags) | JBD_FLAG_SAME_UUID);
 507
 508                 if (tag_info->last_tag)
 509                         jbd_set16(tag, flags,
 510                                   jbd_get16(tag, flags) | JBD_FLAG_LAST_TAG);
 511
 512         }
 513         return EOK;
 514 }
 515
 516 /**@brief  Iterate all block tags in a block.
 517  * @param  jbd_fs jbd filesystem
 518  * @param  __tag_start pointer to the block
 519  * @param  tag_tbl_size size of the block
 520  * @param  func callback routine to indicate that
 521  *         a block tag is found
 522  * @param  arg additional argument to be passed to func */
 523 static void
 524 jbd_iterate_block_table(struct jbd_fs *jbd_fs,
 525                         void *__tag_start,
 526                         int32_t tag_tbl_size,
 527                         void (*func)(struct jbd_fs * jbd_fs,
 528                                         ext4_fsblk_t block,
 529                                         uint8_t *uuid,
 530                                         void *arg),
 531                         void *arg)
 532 {
 533         char *tag_start, *tag_ptr;
 534         int tag_bytes = jbd_tag_bytes(jbd_fs);
 535         tag_start = __tag_start;
 536         tag_ptr = tag_start;
 537
 538         /* Cut off the size of block tail storing checksum. */
 539         if (JBD_HAS_INCOMPAT_FEATURE(&jbd_fs->sb,
 540                                      JBD_FEATURE_INCOMPAT_CSUM_V2) ||
 541             JBD_HAS_INCOMPAT_FEATURE(&jbd_fs->sb,
 542                                      JBD_FEATURE_INCOMPAT_CSUM_V3))
 543                 tag_tbl_size -= sizeof(struct jbd_block_tail);
 544
 545         while (tag_tbl_size) {
 546                 struct tag_info tag_info;
 547                 int rc = jbd_extract_block_tag(jbd_fs,
 548                                       tag_ptr,
 549                                       tag_bytes,
 550                                       tag_tbl_size,
 551                                       &tag_info);
 552                 if (rc != EOK)
 553                         break;
 554
 555                 if (func)
 556                         func(jbd_fs, tag_info.block, tag_info.uuid, arg);
 557
 558                 /* Stop the iteration when we reach the last tag. */
 559                 if (tag_info.last_tag)
 560                         break;
 561
 562                 tag_ptr += tag_info.tag_bytes;
 563                 tag_tbl_size -= tag_info.tag_bytes;
 564         }
 565 }
 566
 567 static void jbd_display_block_tags(struct jbd_fs *jbd_fs,
 568                                    ext4_fsblk_t block,
 569                                    uint8_t *uuid,
 570                                    void *arg)
 571 {
 572         uint32_t *iblock = arg;
 573         ext4_dbg(DEBUG_JBD, "Block in block_tag: %" PRIu64 "\n", block);
 574         (*iblock)++;
 575         (void)jbd_fs;
 576         (void)uuid;
 577         return;
 578 }
 579
 580 static struct revoke_entry *
 581 jbd_revoke_entry_lookup(struct recover_info *info, ext4_fsblk_t block)
 582 {
 583         struct revoke_entry tmp = {
 584                 .block = block
 585         };
 586
 587         return RB_FIND(jbd_revoke, &info->revoke_root, &tmp);
 588 }
 589
 590 /**@brief  Replay a block in a transaction.
 591  * @param  jbd_fs jbd filesystem
 592  * @param  block  block address to be replayed.*/
 593 static void jbd_replay_block_tags(struct jbd_fs *jbd_fs,
 594                                   ext4_fsblk_t block,
 595                                   uint8_t *uuid __unused,
 596                                   void *__arg)
 597 {
 598         int r;
 599         struct replay_arg *arg = __arg;
 600         struct recover_info *info = arg->info;
 601         uint32_t *this_block = arg->this_block;
 602         struct revoke_entry *revoke_entry;
 603         struct ext4_block journal_block, ext4_block;
 604         struct ext4_fs *fs = jbd_fs->inode_ref.fs;
 605
 606         (*this_block)++;
 607
 608         /* We replay this block only if the current transaction id
 609          * is equal or greater than that in revoke entry.*/
 610         revoke_entry = jbd_revoke_entry_lookup(info, block);
 611         if (revoke_entry &&
 612             arg->this_trans_id < revoke_entry->trans_id)
 613                 return;
 614
 615         ext4_dbg(DEBUG_JBD,
 616                  "Replaying block in block_tag: %" PRIu64 "\n",
 617                  block);
 618
 619         r = jbd_block_get(jbd_fs, &journal_block, *this_block);
 620         if (r != EOK)
 621                 return;
 622
 623         /* We need special treatment for ext4 superblock. */
 624         if (block) {
 625                 r = ext4_block_get_noread(fs->bdev, &ext4_block, block);
 626                 if (r != EOK) {
 627                         jbd_block_set(jbd_fs, &journal_block);
 628                         return;
 629                 }
 630
 631                 memcpy(ext4_block.data,
 632                         journal_block.data,
 633                         jbd_get32(&jbd_fs->sb, blocksize));
 634
 635                 ext4_bcache_set_dirty(ext4_block.buf);
 636                 ext4_block_set(fs->bdev, &ext4_block);
 637         } else {
 638                 uint16_t mount_count, state;
 639                 mount_count = ext4_get16(&fs->sb, mount_count);
 640                 state = ext4_get16(&fs->sb, state);
 641
 642                 memcpy(&fs->sb,
 643                         journal_block.data + EXT4_SUPERBLOCK_OFFSET,
 644                         EXT4_SUPERBLOCK_SIZE);
 645
 646                 /* Mark system as mounted */
 647                 ext4_set16(&fs->sb, state, state);
 648                 r = ext4_sb_write(fs->bdev, &fs->sb);
 649                 if (r != EOK)
 650                         return;
 651
 652                 /*Update mount count*/
 653                 ext4_set16(&fs->sb, mount_count, mount_count);
 654         }
 655
 656         jbd_block_set(jbd_fs, &journal_block);
 657
 658         return;
 659 }
 660
 661 /**@brief  Add block address to revoke tree, along with
 662  *         its transaction id.
 663  * @param  info  journal replay info
 664  * @param  block  block address to be replayed.*/
 665 static void jbd_add_revoke_block_tags(struct recover_info *info,
 666                                       ext4_fsblk_t block)
 667 {
 668         struct revoke_entry *revoke_entry;
 669
 670         ext4_dbg(DEBUG_JBD, "Add block %" PRIu64 " to revoke tree\n", block);
 671         /* If the revoke entry with respect to the block address
 672          * exists already, update its transaction id.*/
 673         revoke_entry = jbd_revoke_entry_lookup(info, block);
 674         if (revoke_entry) {
 675                 revoke_entry->trans_id = info->this_trans_id;
 676                 return;
 677         }
 678
 679         revoke_entry = jbd_alloc_revoke_entry();
 680         ext4_assert(revoke_entry);
 681         revoke_entry->block = block;
 682         revoke_entry->trans_id = info->this_trans_id;
 683         RB_INSERT(jbd_revoke, &info->revoke_root, revoke_entry);
 684
 685         return;
 686 }
 687
 688 static void jbd_destroy_revoke_tree(struct recover_info *info)
 689 {
 690         while (!RB_EMPTY(&info->revoke_root)) {
 691                 struct revoke_entry *revoke_entry =
 692                         RB_MIN(jbd_revoke, &info->revoke_root);
 693                 ext4_assert(revoke_entry);
 694                 RB_REMOVE(jbd_revoke, &info->revoke_root, revoke_entry);
 695                 jbd_free_revoke_entry(revoke_entry);
 696         }
 697 }
 698
 699 /* Make sure we wrap around the log correctly! */
 700 #define wrap(sb, var)                                           \
 701 do {                                                                    \
 702         if (var >= jbd_get32((sb), maxlen))                                     \
 703                 var -= (jbd_get32((sb), maxlen) - jbd_get32((sb), first));      \
 704 } while (0)
 705
 706 #define ACTION_SCAN 0
 707 #define ACTION_REVOKE 1
 708 #define ACTION_RECOVER 2
 709
 710 /**@brief  Add entries in a revoke block to revoke tree.
 711  * @param  jbd_fs jbd filesystem
 712  * @param  header revoke block header
 713  * @param  recover_info  journal replay info*/
 714 static void jbd_build_revoke_tree(struct jbd_fs *jbd_fs,
 715                                   struct jbd_bhdr *header,
 716                                   struct recover_info *info)
 717 {
 718         char *blocks_entry;
 719         struct jbd_revoke_header *revoke_hdr =
 720                 (struct jbd_revoke_header *)header;
 721         uint32_t i, nr_entries, record_len = 4;
 722
 723         /* If we are working on a 64bit jbd filesystem, */
 724         if (JBD_HAS_INCOMPAT_FEATURE(&jbd_fs->sb,
 725                                      JBD_FEATURE_INCOMPAT_64BIT))
 726                 record_len = 8;
 727
 728         nr_entries = (jbd_get32(revoke_hdr, count) -
 729                         sizeof(struct jbd_revoke_header)) /
 730                         record_len;
 731
 732         blocks_entry = (char *)(revoke_hdr + 1);
 733
 734         for (i = 0;i < nr_entries;i++) {
 735                 if (record_len == 8) {
 736                         uint64_t *blocks =
 737                                 (uint64_t *)blocks_entry;
 738                         jbd_add_revoke_block_tags(info, to_be64(*blocks));
 739                 } else {
 740                         uint32_t *blocks =
 741                                 (uint32_t *)blocks_entry;
 742                         jbd_add_revoke_block_tags(info, to_be32(*blocks));
 743                 }
 744                 blocks_entry += record_len;
 745         }
 746 }
 747
 748 static void jbd_debug_descriptor_block(struct jbd_fs *jbd_fs,
 749                                        struct jbd_bhdr *header,
 750                                        uint32_t *iblock)
 751 {
 752         jbd_iterate_block_table(jbd_fs,
 753                                 header + 1,
 754                                 jbd_get32(&jbd_fs->sb, blocksize) -
 755                                         sizeof(struct jbd_bhdr),
 756                                 jbd_display_block_tags,
 757                                 iblock);
 758 }
 759
 760 static void jbd_replay_descriptor_block(struct jbd_fs *jbd_fs,
 761                                         struct jbd_bhdr *header,
 762                                         struct replay_arg *arg)
 763 {
 764         jbd_iterate_block_table(jbd_fs,
 765                                 header + 1,
 766                                 jbd_get32(&jbd_fs->sb, blocksize) -
 767                                         sizeof(struct jbd_bhdr),
 768                                 jbd_replay_block_tags,
 769                                 arg);
 770 }
 771
 772 /**@brief  The core routine of journal replay.
 773  * @param  jbd_fs jbd filesystem
 774  * @param  recover_info  journal replay info
 775  * @param  action action needed to be taken
 776  * @return standard error code*/
 777 int jbd_iterate_log(struct jbd_fs *jbd_fs,
 778                     struct recover_info *info,
 779                     int action)
 780 {
 781         int r = EOK;
 782         bool log_end = false;
 783         struct jbd_sb *sb = &jbd_fs->sb;
 784         uint32_t start_trans_id, this_trans_id;
 785         uint32_t start_block, this_block;
 786
 787         /* We start iterating valid blocks in the whole journal.*/
 788         start_trans_id = this_trans_id = jbd_get32(sb, sequence);
 789         start_block = this_block = jbd_get32(sb, start);
 790
 791         ext4_dbg(DEBUG_JBD, "Start of journal at trans id: %" PRIu32 "\n",
 792                             start_trans_id);
 793
 794         while (!log_end) {
 795                 struct ext4_block block;
 796                 struct jbd_bhdr *header;
 797                 /* If we are not scanning for the last
 798                  * valid transaction in the journal,
 799                  * we will stop when we reach the end of
 800                  * the journal.*/
 801                 if (action != ACTION_SCAN)
 802                         if (this_trans_id > info->last_trans_id) {
 803                                 log_end = true;
 804                                 continue;
 805                         }
 806
 807                 r = jbd_block_get(jbd_fs, &block, this_block);
 808                 if (r != EOK)
 809                         break;
 810
 811                 header = (struct jbd_bhdr *)block.data;
 812                 /* This block does not have a valid magic number,
 813                  * so we have reached the end of the journal.*/
 814                 if (jbd_get32(header, magic) != JBD_MAGIC_NUMBER) {
 815                         jbd_block_set(jbd_fs, &block);
 816                         log_end = true;
 817                         continue;
 818                 }
 819
 820                 /* If the transaction id we found is not expected,
 821                  * we may have reached the end of the journal.
 822                  *
 823                  * If we are not scanning the journal, something
 824                  * bad might have taken place. :-( */
 825                 if (jbd_get32(header, sequence) != this_trans_id) {
 826                         if (action != ACTION_SCAN)
 827                                 r = EIO;
 828
 829                         jbd_block_set(jbd_fs, &block);
 830                         log_end = true;
 831                         continue;
 832                 }
 833
 834                 switch (jbd_get32(header, blocktype)) {
 835                 case JBD_DESCRIPTOR_BLOCK:
 836                         ext4_dbg(DEBUG_JBD, "Descriptor block: %" PRIu32", "
 837                                             "trans_id: %" PRIu32"\n",
 838                                             this_block, this_trans_id);
 839                         if (action == ACTION_RECOVER) {
 840                                 struct replay_arg replay_arg;
 841                                 replay_arg.info = info;
 842                                 replay_arg.this_block = &this_block;
 843                                 replay_arg.this_trans_id = this_trans_id;
 844
 845                                 jbd_replay_descriptor_block(jbd_fs,
 846                                                 header, &replay_arg);
 847                         } else
 848                                 jbd_debug_descriptor_block(jbd_fs,
 849                                                 header, &this_block);
 850
 851                         break;
 852                 case JBD_COMMIT_BLOCK:
 853                         ext4_dbg(DEBUG_JBD, "Commit block: %" PRIu32", "
 854                                             "trans_id: %" PRIu32"\n",
 855                                             this_block, this_trans_id);
 856                         /* This is the end of a transaction,
 857                          * we may now proceed to the next transaction.
 858                          */
 859                         this_trans_id++;
 860                         break;
 861                 case JBD_REVOKE_BLOCK:
 862                         ext4_dbg(DEBUG_JBD, "Revoke block: %" PRIu32", "
 863                                             "trans_id: %" PRIu32"\n",
 864                                             this_block, this_trans_id);
 865                         if (action == ACTION_REVOKE) {
 866                                 info->this_trans_id = this_trans_id;
 867                                 jbd_build_revoke_tree(jbd_fs,
 868                                                 header, info);
 869                         }
 870                         break;
 871                 default:
 872                         log_end = true;
 873                         break;
 874                 }
 875                 jbd_block_set(jbd_fs, &block);
 876                 this_block++;
 877                 wrap(sb, this_block);
 878                 if (this_block == start_block)
 879                         log_end = true;
 880
 881         }
 882         ext4_dbg(DEBUG_JBD, "End of journal.\n");
 883         if (r == EOK && action == ACTION_SCAN) {
 884                 /* We have finished scanning the journal. */
 885                 info->start_trans_id = start_trans_id;
 886                 if (this_trans_id > start_trans_id)
 887                         info->last_trans_id = this_trans_id - 1;
 888                 else
 889                         info->last_trans_id = this_trans_id;
 890         }
 891
 892         return r;
 893 }
 894
 895 /**@brief  Replay journal.
 896  * @param  jbd_fs jbd filesystem
 897  * @return standard error code*/
 898 int jbd_recover(struct jbd_fs *jbd_fs)
 899 {
 900         int r;
 901         struct recover_info info;
 902         struct jbd_sb *sb = &jbd_fs->sb;
 903         if (!sb->start)
 904                 return EOK;
 905
 906         RB_INIT(&info.revoke_root);
 907
 908         r = jbd_iterate_log(jbd_fs, &info, ACTION_SCAN);
 909         if (r != EOK)
 910                 return r;
 911
 912         r = jbd_iterate_log(jbd_fs, &info, ACTION_REVOKE);
 913         if (r != EOK)
 914                 return r;
 915
 916         r = jbd_iterate_log(jbd_fs, &info, ACTION_RECOVER);
 917         if (r == EOK) {
 918                 /* If we successfully replay the journal,
 919                  * clear EXT4_FINCOM_RECOVER flag on the
 920                  * ext4 superblock, and set the start of
 921                  * journal to 0.*/
 922                 uint32_t features_incompatible =
 923                         ext4_get32(&jbd_fs->inode_ref.fs->sb,
 924                                    features_incompatible);
 925                 jbd_set32(&jbd_fs->sb, start, 0);
 926                 features_incompatible &= ~EXT4_FINCOM_RECOVER;
 927                 ext4_set32(&jbd_fs->inode_ref.fs->sb,
 928                            features_incompatible,
 929                            features_incompatible);
 930                 jbd_fs->dirty = true;
 931                 r = ext4_sb_write(jbd_fs->inode_ref.fs->bdev,
 932                                   &jbd_fs->inode_ref.fs->sb);
 933         }
 934         jbd_destroy_revoke_tree(&info);
 935         return r;
 936 }
 937
 938 void jbd_journal_write_sb(struct jbd_journal *journal)
 939 {
 940         struct jbd_fs *jbd_fs = journal->jbd_fs;
 941         jbd_set32(&jbd_fs->sb, start, journal->start);
 942         jbd_set32(&jbd_fs->sb, sequence, journal->trans_id);
 943         jbd_fs->dirty = true;
 944 }
 945
 946 /**@brief  Start accessing the journal.
 947  * @param  jbd_fs jbd filesystem
 948  * @param  journal current journal session
 949  * @return standard error code*/
 950 int jbd_journal_start(struct jbd_fs *jbd_fs,
 951                       struct jbd_journal *journal)
 952 {
 953         int r;
 954         uint32_t features_incompatible =
 955                         ext4_get32(&jbd_fs->inode_ref.fs->sb,
 956                                    features_incompatible);
 957         features_incompatible |= EXT4_FINCOM_RECOVER;
 958         ext4_set32(&jbd_fs->inode_ref.fs->sb,
 959                         features_incompatible,
 960                         features_incompatible);
 961         r = ext4_sb_write(jbd_fs->inode_ref.fs->bdev,
 962                         &jbd_fs->inode_ref.fs->sb);
 963         if (r != EOK)
 964                 return r;
 965
 966         journal->first = jbd_get32(&jbd_fs->sb, first);
 967         journal->start = journal->first;
 968         journal->last = journal->first;
 969         journal->trans_id = 1;
 970         journal->alloc_trans_id = 1;
 971
 972         journal->block_size = jbd_get32(&jbd_fs->sb, blocksize);
 973
 974         TAILQ_INIT(&journal->trans_queue);
 975         TAILQ_INIT(&journal->cp_queue);
 976         journal->jbd_fs = jbd_fs;
 977         jbd_journal_write_sb(journal);
 978         return jbd_write_sb(jbd_fs);
 979 }
 980
 981 /**@brief  Stop accessing the journal.
 982  * @param  journal current journal session
 983  * @return standard error code*/
 984 int jbd_journal_stop(struct jbd_journal *journal)
 985 {
 986         int r;
 987         struct jbd_fs *jbd_fs = journal->jbd_fs;
 988         uint32_t features_incompatible;
 989
 990         /* Commit all the transactions to the journal.*/
 991         jbd_journal_commit_all(journal);
 992         /* Make sure that journalled content have reached
 993          * the disk.*/
 994         ext4_block_cache_flush(jbd_fs->inode_ref.fs->bdev);
 995
 996         features_incompatible =
 997                 ext4_get32(&jbd_fs->inode_ref.fs->sb,
 998                            features_incompatible);
 999         features_incompatible &= ~EXT4_FINCOM_RECOVER;
1000         ext4_set32(&jbd_fs->inode_ref.fs->sb,
1001                         features_incompatible,
1002                         features_incompatible);
1003         r = ext4_sb_write(jbd_fs->inode_ref.fs->bdev,
1004                         &jbd_fs->inode_ref.fs->sb);
1005         if (r != EOK)
1006                 return r;
1007
1008         journal->start = 0;
1009         journal->trans_id = 0;
1010         jbd_journal_write_sb(journal);
1011         return jbd_write_sb(journal->jbd_fs);
1012 }
1013
1014 /**@brief  Allocate a block in the journal.
1015  * @param  journal current journal session
1016  * @param  trans transaction
1017  * @return allocated block address*/
1018 static uint32_t jbd_journal_alloc_block(struct jbd_journal *journal,
1019                                         struct jbd_trans *trans)
1020 {
1021         uint32_t start_block;
1022
1023         start_block = journal->last++;
1024         trans->alloc_blocks++;
1025         wrap(&journal->jbd_fs->sb, journal->last);
1026
1027         /* If there is no space left, flush all journalled
1028          * blocks to disk first.*/
1029         if (journal->last == journal->start)
1030                 ext4_block_cache_flush(journal->jbd_fs->inode_ref.fs->bdev);
1031
1032         return start_block;
1033 }
1034
1035 /**@brief  Allocate a new transaction
1036  * @param  journal current journal session
1037  * @return transaction allocated*/
1038 struct jbd_trans *
1039 jbd_journal_new_trans(struct jbd_journal *journal)
1040 {
1041         struct jbd_trans *trans = calloc(1, sizeof(struct jbd_trans));
1042         if (!trans)
1043                 return NULL;
1044
1045         /* We will assign a trans_id to this transaction,
1046          * once it has been committed.*/
1047         trans->journal = journal;
1048         trans->error = EOK;
1049         return trans;
1050 }
1051
1052 static void jbd_trans_end_write(struct ext4_bcache *bc __unused,
1053                           struct ext4_buf *buf __unused,
1054                           int res,
1055                           void *arg);
1056
1057 /**@brief  Add block to a transaction
1058  * @param  trans transaction
1059  * @param  block block descriptor
1060  * @return standard error code*/
1061 int jbd_trans_add_block(struct jbd_trans *trans,
1062                         struct ext4_block *block)
1063 {
1064         struct jbd_buf *buf;
1065         /* We do not need to add those unmodified buffer to
1066          * a transaction. */
1067         if (!ext4_bcache_test_flag(block->buf, BC_DIRTY))
1068                 return EOK;
1069
1070         buf = calloc(1, sizeof(struct jbd_buf));
1071         if (!buf)
1072                 return ENOMEM;
1073
1074         buf->trans = trans;
1075         buf->block = *block;
1076         ext4_bcache_inc_ref(block->buf);
1077
1078         /* If the content reach the disk, notify us
1079          * so that we may do a checkpoint. */
1080         block->buf->end_write = jbd_trans_end_write;
1081         block->buf->end_write_arg = trans;
1082
1083         trans->data_cnt++;
1084         LIST_INSERT_HEAD(&trans->buf_list, buf, buf_node);
1085         return EOK;
1086 }
1087
1088 /**@brief  Add block to be revoked to a transaction
1089  * @param  trans transaction
1090  * @param  lba logical block address
1091  * @return standard error code*/
1092 int jbd_trans_revoke_block(struct jbd_trans *trans,
1093                            ext4_fsblk_t lba)
1094 {
1095         struct jbd_revoke_rec *rec =
1096                 calloc(1, sizeof(struct jbd_revoke_rec));
1097         if (!rec)
1098                 return ENOMEM;
1099
1100         rec->lba = lba;
1101         LIST_INSERT_HEAD(&trans->revoke_list, rec, revoke_node);
1102         return EOK;
1103 }
1104
1105 /**@brief  Free a transaction
1106  * @param  journal current journal session
1107  * @param  trans transaction
1108  * @param  abort discard all the modifications on the block?
1109  * @return standard error code*/
1110 void jbd_journal_free_trans(struct jbd_journal *journal,
1111                             struct jbd_trans *trans,
1112                             bool abort)
1113 {
1114         struct jbd_buf *jbd_buf, *tmp;
1115         struct jbd_revoke_rec *rec, *tmp2;
1116         struct ext4_fs *fs = journal->jbd_fs->inode_ref.fs;
1117         LIST_FOREACH_SAFE(jbd_buf, &trans->buf_list, buf_node,
1118                           tmp) {
1119                 if (abort) {
1120                         ext4_bcache_clear_dirty(jbd_buf->block.buf);
1121                         ext4_block_set(fs->bdev, &jbd_buf->block);
1122                 }
1123
1124                 LIST_REMOVE(jbd_buf, buf_node);
1125                 free(jbd_buf);
1126         }
1127         LIST_FOREACH_SAFE(rec, &trans->revoke_list, revoke_node,
1128                           tmp2) {
1129                 LIST_REMOVE(rec, revoke_node);
1130                 free(rec);
1131         }
1132
1133         free(trans);
1134 }
1135
1136 /**@brief  Write commit block for a transaction
1137  * @param  trans transaction
1138  * @return standard error code*/
1139 static int jbd_trans_write_commit_block(struct jbd_trans *trans)
1140 {
1141         int rc;
1142         struct jbd_commit_header *header;
1143         uint32_t commit_iblock = 0;
1144         struct ext4_block commit_block;
1145         struct jbd_journal *journal = trans->journal;
1146
1147         commit_iblock = jbd_journal_alloc_block(journal, trans);
1148         rc = jbd_block_get_noread(journal->jbd_fs,
1149                         &commit_block, commit_iblock);
1150         if (rc != EOK)
1151                 return rc;
1152
1153         header = (struct jbd_commit_header *)commit_block.data;
1154         jbd_set32(&header->header, magic, JBD_MAGIC_NUMBER);
1155         jbd_set32(&header->header, blocktype, JBD_COMMIT_BLOCK);
1156         jbd_set32(&header->header, sequence, trans->trans_id);
1157
1158         ext4_bcache_set_dirty(commit_block.buf);
1159         rc = jbd_block_set(journal->jbd_fs, &commit_block);
1160         if (rc != EOK)
1161                 return rc;
1162
1163         return EOK;
1164 }
1165
1166 /**@brief  Write descriptor block for a transaction
1167  * @param  journal current journal session
1168  * @param  trans transaction
1169  * @return standard error code*/
1170 static int jbd_journal_prepare(struct jbd_journal *journal,
1171                                struct jbd_trans *trans)
1172 {
1173         int rc = EOK, i = 0;
1174         int32_t tag_tbl_size;
1175         uint32_t desc_iblock = 0;
1176         uint32_t data_iblock = 0;
1177         char *tag_start = NULL, *tag_ptr = NULL;
1178         struct jbd_buf *jbd_buf;
1179         struct ext4_block desc_block, data_block;
1180
1181         LIST_FOREACH(jbd_buf, &trans->buf_list, buf_node) {
1182                 struct tag_info tag_info;
1183                 bool uuid_exist = false;
1184 again:
1185                 if (!desc_iblock) {
1186                         struct jbd_bhdr *bhdr;
1187                         desc_iblock = jbd_journal_alloc_block(journal, trans);
1188                         rc = jbd_block_get_noread(journal->jbd_fs,
1189                                            &desc_block, desc_iblock);
1190                         if (rc != EOK)
1191                                 break;
1192
1193                         ext4_bcache_set_dirty(desc_block.buf);
1194
1195                         bhdr = (struct jbd_bhdr *)desc_block.data;
1196                         jbd_set32(bhdr, magic, JBD_MAGIC_NUMBER);
1197                         jbd_set32(bhdr, blocktype, JBD_DESCRIPTOR_BLOCK);
1198                         jbd_set32(bhdr, sequence, trans->trans_id);
1199
1200                         tag_start = (char *)(bhdr + 1);
1201                         tag_ptr = tag_start;
1202                         uuid_exist = true;
1203                         tag_tbl_size = journal->block_size -
1204                                 sizeof(struct jbd_bhdr);
1205
1206                         if (!trans->start_iblock)
1207                                 trans->start_iblock = desc_iblock;
1208
1209                 }
1210                 tag_info.block = jbd_buf->block.lb_id;
1211                 tag_info.uuid_exist = uuid_exist;
1212                 if (i == trans->data_cnt - 1)
1213                         tag_info.last_tag = true;
1214
1215                 if (uuid_exist)
1216                         memcpy(tag_info.uuid, journal->jbd_fs->sb.uuid,
1217                                         UUID_SIZE);
1218
1219                 rc = jbd_write_block_tag(journal->jbd_fs,
1220                                 tag_ptr,
1221                                 tag_tbl_size,
1222                                 &tag_info);
1223                 if (rc != EOK) {
1224                         jbd_block_set(journal->jbd_fs, &desc_block);
1225                         desc_iblock = 0;
1226                         goto again;
1227                 }
1228
1229                 data_iblock = jbd_journal_alloc_block(journal, trans);
1230                 rc = jbd_block_get_noread(journal->jbd_fs,
1231                                 &data_block, data_iblock);
1232                 if (rc != EOK)
1233                         break;
1234
1235                 ext4_bcache_set_dirty(data_block.buf);
1236
1237                 memcpy(data_block.data, jbd_buf->block.data,
1238                         journal->block_size);
1239
1240                 rc = jbd_block_set(journal->jbd_fs, &data_block);
1241                 if (rc != EOK)
1242                         break;
1243
1244                 tag_ptr += tag_info.tag_bytes;
1245                 tag_tbl_size -= tag_info.tag_bytes;
1246
1247                 i++;
1248         }
1249         if (rc == EOK && desc_iblock)
1250                 jbd_block_set(journal->jbd_fs, &desc_block);
1251
1252         return rc;
1253 }
1254
1255 /**@brief  Write revoke block for a transaction
1256  * @param  journal current journal session
1257  * @param  trans transaction
1258  * @return standard error code*/
1259 static int
1260 jbd_journal_prepare_revoke(struct jbd_journal *journal,
1261                            struct jbd_trans *trans)
1262 {
1263         int rc = EOK, i = 0;
1264         int32_t tag_tbl_size;
1265         uint32_t desc_iblock = 0;
1266         char *blocks_entry = NULL;
1267         struct jbd_revoke_rec *rec, *tmp;
1268         struct ext4_block desc_block;
1269         struct jbd_revoke_header *header = NULL;
1270         int32_t record_len = 4;
1271
1272         if (JBD_HAS_INCOMPAT_FEATURE(&journal->jbd_fs->sb,
1273                                      JBD_FEATURE_INCOMPAT_64BIT))
1274                 record_len = 8;
1275
1276         LIST_FOREACH_SAFE(rec, &trans->revoke_list, revoke_node,
1277                           tmp) {
1278 again:
1279                 if (!desc_iblock) {
1280                         struct jbd_bhdr *bhdr;
1281                         desc_iblock = jbd_journal_alloc_block(journal, trans);
1282                         rc = jbd_block_get_noread(journal->jbd_fs,
1283                                            &desc_block, desc_iblock);
1284                         if (rc != EOK) {
1285                                 break;
1286                         }
1287
1288                         ext4_bcache_set_dirty(desc_block.buf);
1289
1290                         bhdr = (struct jbd_bhdr *)desc_block.data;
1291                         jbd_set32(bhdr, magic, JBD_MAGIC_NUMBER);
1292                         jbd_set32(bhdr, blocktype, JBD_REVOKE_BLOCK);
1293                         jbd_set32(bhdr, sequence, trans->trans_id);
1294
1295                         header = (struct jbd_revoke_header *)bhdr;
1296                         blocks_entry = (char *)(header + 1);
1297                         tag_tbl_size = journal->block_size -
1298                                 sizeof(struct jbd_revoke_header);
1299
1300                         if (!trans->start_iblock)
1301                                 trans->start_iblock = desc_iblock;
1302
1303                 }
1304
1305                 if (tag_tbl_size < record_len) {
1306                         jbd_set32(header, count,
1307                                   journal->block_size - tag_tbl_size);
1308                         jbd_block_set(journal->jbd_fs, &desc_block);
1309                         desc_iblock = 0;
1310                         header = NULL;
1311                         goto again;
1312                 }
1313                 if (record_len == 8) {
1314                         uint64_t *blocks =
1315                                 (uint64_t *)blocks_entry;
1316                         *blocks = to_be64(rec->lba);
1317                 } else {
1318                         uint32_t *blocks =
1319                                 (uint32_t *)blocks_entry;
1320                         *blocks = to_be32(rec->lba);
1321                 }
1322                 blocks_entry += record_len;
1323                 tag_tbl_size -= record_len;
1324
1325                 i++;
1326         }
1327         if (rc == EOK && desc_iblock) {
1328                 if (header != NULL)
1329                         jbd_set32(header, count,
1330                                   journal->block_size - tag_tbl_size);
1331
1332                 jbd_block_set(journal->jbd_fs, &desc_block);
1333         }
1334
1335         return rc;
1336 }
1337
1338 /**@brief  Submit the transaction to transaction queue.
1339  * @param  journal current journal session
1340  * @param  trans transaction*/
1341 void
1342 jbd_journal_submit_trans(struct jbd_journal *journal,
1343                          struct jbd_trans *trans)
1344 {
1345         TAILQ_INSERT_TAIL(&journal->trans_queue,
1346                           trans,
1347                           trans_node);
1348 }
1349
1350 /**@brief  Put references of block descriptors in a transaction.
1351  * @param  journal current journal session
1352  * @param  trans transaction*/
1353 void jbd_journal_cp_trans(struct jbd_journal *journal, struct jbd_trans *trans)
1354 {
1355         struct jbd_buf *jbd_buf, *tmp;
1356         struct ext4_fs *fs = journal->jbd_fs->inode_ref.fs;
1357         LIST_FOREACH_SAFE(jbd_buf, &trans->buf_list, buf_node,
1358                         tmp) {
1359                 struct ext4_block block = jbd_buf->block;
1360                 ext4_block_set(fs->bdev, &block);
1361         }
1362 }
1363
1364 /**@brief  Update the start block of the journal when
1365  *         all the contents in a transaction reach the disk.*/
1366 static void jbd_trans_end_write(struct ext4_bcache *bc __unused,
1367                           struct ext4_buf *buf __unused,
1368                           int res,
1369                           void *arg)
1370 {
1371         struct jbd_trans *trans = arg;
1372         struct jbd_journal *journal = trans->journal;
1373         bool first_in_queue =
1374                 trans == TAILQ_FIRST(&journal->cp_queue);
1375         if (res != EOK)
1376                 trans->error = res;
1377
1378         trans->written_cnt++;
1379         if (trans->written_cnt == trans->data_cnt) {
1380                 TAILQ_REMOVE(&journal->cp_queue, trans, trans_node);
1381
1382                 if (first_in_queue) {
1383                         journal->start = trans->start_iblock +
1384                                 trans->alloc_blocks;
1385                         wrap(&journal->jbd_fs->sb, journal->start);
1386                         journal->trans_id = trans->trans_id + 1;
1387                 }
1388                 jbd_journal_free_trans(journal, trans, false);
1389
1390                 if (first_in_queue) {
1391                         while ((trans = TAILQ_FIRST(&journal->cp_queue))) {
1392                                 if (!trans->data_cnt) {
1393                                         TAILQ_REMOVE(&journal->cp_queue,
1394                                                      trans,
1395                                                      trans_node);
1396                                         journal->start = trans->start_iblock +
1397                                                 trans->alloc_blocks;
1398                                         wrap(&journal->jbd_fs->sb, journal->start);
1399                                         journal->trans_id = trans->trans_id + 1;
1400                                         jbd_journal_free_trans(journal,
1401                                                                trans, false);
1402                                 } else {
1403                                         journal->start = trans->start_iblock;
1404                                         wrap(&journal->jbd_fs->sb, journal->start);
1405                                         journal->trans_id = trans->trans_id;
1406                                         break;
1407                                 }
1408                         }
1409                         jbd_journal_write_sb(journal);
1410                         jbd_write_sb(journal->jbd_fs);
1411                 }
1412         }
1413 }
1414
1415 /**@brief  Commit a transaction to the journal immediately.
1416  * @param  journal current journal session
1417  * @param  trans transaction
1418  * @return standard error code*/
1419 int jbd_journal_commit_trans(struct jbd_journal *journal,
1420                              struct jbd_trans *trans)
1421 {
1422         int rc = EOK;
1423         uint32_t last = journal->last;
1424
1425         trans->trans_id = journal->alloc_trans_id;
1426         rc = jbd_journal_prepare(journal, trans);
1427         if (rc != EOK)
1428                 goto Finish;
1429
1430         rc = jbd_journal_prepare_revoke(journal, trans);
1431         if (rc != EOK)
1432                 goto Finish;
1433
1434         rc = jbd_trans_write_commit_block(trans);
1435         if (rc != EOK)
1436                 goto Finish;
1437
1438         journal->alloc_trans_id++;
1439         if (TAILQ_EMPTY(&journal->cp_queue)) {
1440                 if (trans->data_cnt) {
1441                         journal->start = trans->start_iblock;
1442                         wrap(&journal->jbd_fs->sb, journal->start);
1443                         journal->trans_id = trans->trans_id;
1444                         jbd_journal_write_sb(journal);
1445                         jbd_write_sb(journal->jbd_fs);
1446                         TAILQ_INSERT_TAIL(&journal->cp_queue, trans,
1447                                         trans_node);
1448                         jbd_journal_cp_trans(journal, trans);
1449                 } else {
1450                         journal->start = trans->start_iblock +
1451                                 trans->alloc_blocks;
1452                         wrap(&journal->jbd_fs->sb, journal->start);
1453                         journal->trans_id = trans->trans_id + 1;
1454                         jbd_journal_write_sb(journal);
1455                         jbd_journal_free_trans(journal, trans, false);
1456                 }
1457         } else {
1458                 TAILQ_INSERT_TAIL(&journal->cp_queue, trans,
1459                                 trans_node);
1460                 if (trans->data_cnt)
1461                         jbd_journal_cp_trans(journal, trans);
1462
1463         }
1464 Finish:
1465         if (rc != EOK) {
1466                 journal->last = last;
1467                 jbd_journal_free_trans(journal, trans, true);
1468         }
1469         return rc;
1470 }
1471
1472 /**@brief  Commit one transaction on transaction queue
1473  *         to the journal.
1474  * @param  journal current journal session.*/
1475 void jbd_journal_commit_one(struct jbd_journal *journal)
1476 {
1477         struct jbd_trans *trans;
1478
1479         if ((trans = TAILQ_FIRST(&journal->trans_queue))) {
1480                 TAILQ_REMOVE(&journal->trans_queue, trans, trans_node);
1481                 jbd_journal_commit_trans(journal, trans);
1482         }
1483 }
1484
1485 /**@brief  Commit all the transactions on transaction queue
1486  *         to the journal.
1487  * @param  journal current journal session.*/
1488 void jbd_journal_commit_all(struct jbd_journal *journal)
1489 {
1490         while (!TAILQ_EMPTY(&journal->trans_queue)) {
1491                 jbd_journal_commit_one(journal);
1492         }
1493 }
1494
1495 /**
1496  * @}
1497  */