1 /* 2 * linux/fs/jbd2/checkpoint.c 3 * 4 * Written by Stephen C. Tweedie <sct@redhat.com>, 1999 5 * 6 * Copyright 1999 Red Hat Software --- All Rights Reserved 7 * 8 * This file is part of the Linux kernel and is made available under 9 * the terms of the GNU General Public License, version 2, or at your 10 * option, any later version, incorporated herein by reference. 11 * 12 * Checkpoint routines for the generic filesystem journaling code. 13 * Part of the ext2fs journaling system. 14 * 15 * Checkpointing is the process of ensuring that a section of the log is 16 * committed fully to disk, so that that portion of the log can be 17 * reused. 18 */ 19 20 #include <linux/time.h> 21 #include <linux/fs.h> 22 #include <linux/jbd2.h> 23 #include <linux/marker.h> 24 #include <linux/errno.h> 25 #include <linux/slab.h> 26 27 /* 28 * Unlink a buffer from a transaction checkpoint list. 29 * 30 * Called with j_list_lock held. 31 */ 32 static inline void __buffer_unlink_first(struct journal_head *jh) 33 { 34 transaction_t *transaction = jh->b_cp_transaction; 35 36 jh->b_cpnext->b_cpprev = jh->b_cpprev; 37 jh->b_cpprev->b_cpnext = jh->b_cpnext; 38 if (transaction->t_checkpoint_list == jh) { 39 transaction->t_checkpoint_list = jh->b_cpnext; 40 if (transaction->t_checkpoint_list == jh) 41 transaction->t_checkpoint_list = NULL; 42 } 43 } 44 45 /* 46 * Unlink a buffer from a transaction checkpoint(io) list. 47 * 48 * Called with j_list_lock held. 49 */ 50 static inline void __buffer_unlink(struct journal_head *jh) 51 { 52 transaction_t *transaction = jh->b_cp_transaction; 53 54 __buffer_unlink_first(jh); 55 if (transaction->t_checkpoint_io_list == jh) { 56 transaction->t_checkpoint_io_list = jh->b_cpnext; 57 if (transaction->t_checkpoint_io_list == jh) 58 transaction->t_checkpoint_io_list = NULL; 59 } 60 } 61 62 /* 63 * Move a buffer from the checkpoint list to the checkpoint io list 64 * 65 * Called with j_list_lock held 66 */ 67 static inline void __buffer_relink_io(struct journal_head *jh) 68 { 69 transaction_t *transaction = jh->b_cp_transaction; 70 71 __buffer_unlink_first(jh); 72 73 if (!transaction->t_checkpoint_io_list) { 74 jh->b_cpnext = jh->b_cpprev = jh; 75 } else { 76 jh->b_cpnext = transaction->t_checkpoint_io_list; 77 jh->b_cpprev = transaction->t_checkpoint_io_list->b_cpprev; 78 jh->b_cpprev->b_cpnext = jh; 79 jh->b_cpnext->b_cpprev = jh; 80 } 81 transaction->t_checkpoint_io_list = jh; 82 } 83 84 /* 85 * Try to release a checkpointed buffer from its transaction. 86 * Returns 1 if we released it and 2 if we also released the 87 * whole transaction. 88 * 89 * Requires j_list_lock 90 * Called under jbd_lock_bh_state(jh2bh(jh)), and drops it 91 */ 92 static int __try_to_free_cp_buf(struct journal_head *jh) 93 { 94 int ret = 0; 95 struct buffer_head *bh = jh2bh(jh); 96 97 if (jh->b_jlist == BJ_None && !buffer_locked(bh) && 98 !buffer_dirty(bh) && !buffer_write_io_error(bh)) { 99 JBUFFER_TRACE(jh, "remove from checkpoint list"); 100 ret = __jbd2_journal_remove_checkpoint(jh) + 1; 101 jbd_unlock_bh_state(bh); 102 jbd2_journal_remove_journal_head(bh); 103 BUFFER_TRACE(bh, "release"); 104 __brelse(bh); 105 } else { 106 jbd_unlock_bh_state(bh); 107 } 108 return ret; 109 } 110 111 /* 112 * __jbd2_log_wait_for_space: wait until there is space in the journal. 113 * 114 * Called under j-state_lock *only*. It will be unlocked if we have to wait 115 * for a checkpoint to free up some space in the log. 116 */ 117 void __jbd2_log_wait_for_space(journal_t *journal) 118 { 119 int nblocks; 120 assert_spin_locked(&journal->j_state_lock); 121 122 nblocks = jbd_space_needed(journal); 123 while (__jbd2_log_space_left(journal) < nblocks) { 124 if (journal->j_flags & JBD2_ABORT) 125 return; 126 spin_unlock(&journal->j_state_lock); 127 mutex_lock(&journal->j_checkpoint_mutex); 128 129 /* 130 * Test again, another process may have checkpointed while we 131 * were waiting for the checkpoint lock. If there are no 132 * outstanding transactions there is nothing to checkpoint and 133 * we can't make progress. Abort the journal in this case. 134 */ 135 spin_lock(&journal->j_state_lock); 136 spin_lock(&journal->j_list_lock); 137 nblocks = jbd_space_needed(journal); 138 if (__jbd2_log_space_left(journal) < nblocks) { 139 int chkpt = journal->j_checkpoint_transactions != NULL; 140 141 spin_unlock(&journal->j_list_lock); 142 spin_unlock(&journal->j_state_lock); 143 if (chkpt) { 144 jbd2_log_do_checkpoint(journal); 145 } else { 146 printk(KERN_ERR "%s: no transactions\n", 147 __func__); 148 jbd2_journal_abort(journal, 0); 149 } 150 151 spin_lock(&journal->j_state_lock); 152 } else { 153 spin_unlock(&journal->j_list_lock); 154 } 155 mutex_unlock(&journal->j_checkpoint_mutex); 156 } 157 } 158 159 /* 160 * We were unable to perform jbd_trylock_bh_state() inside j_list_lock. 161 * The caller must restart a list walk. Wait for someone else to run 162 * jbd_unlock_bh_state(). 163 */ 164 static void jbd_sync_bh(journal_t *journal, struct buffer_head *bh) 165 __releases(journal->j_list_lock) 166 { 167 get_bh(bh); 168 spin_unlock(&journal->j_list_lock); 169 jbd_lock_bh_state(bh); 170 jbd_unlock_bh_state(bh); 171 put_bh(bh); 172 } 173 174 /* 175 * Clean up transaction's list of buffers submitted for io. 176 * We wait for any pending IO to complete and remove any clean 177 * buffers. Note that we take the buffers in the opposite ordering 178 * from the one in which they were submitted for IO. 179 * 180 * Return 0 on success, and return <0 if some buffers have failed 181 * to be written out. 182 * 183 * Called with j_list_lock held. 184 */ 185 static int __wait_cp_io(journal_t *journal, transaction_t *transaction) 186 { 187 struct journal_head *jh; 188 struct buffer_head *bh; 189 tid_t this_tid; 190 int released = 0; 191 int ret = 0; 192 193 this_tid = transaction->t_tid; 194 restart: 195 /* Did somebody clean up the transaction in the meanwhile? */ 196 if (journal->j_checkpoint_transactions != transaction || 197 transaction->t_tid != this_tid) 198 return ret; 199 while (!released && transaction->t_checkpoint_io_list) { 200 jh = transaction->t_checkpoint_io_list; 201 bh = jh2bh(jh); 202 if (!jbd_trylock_bh_state(bh)) { 203 jbd_sync_bh(journal, bh); 204 spin_lock(&journal->j_list_lock); 205 goto restart; 206 } 207 if (buffer_locked(bh)) { 208 atomic_inc(&bh->b_count); 209 spin_unlock(&journal->j_list_lock); 210 jbd_unlock_bh_state(bh); 211 wait_on_buffer(bh); 212 /* the journal_head may have gone by now */ 213 BUFFER_TRACE(bh, "brelse"); 214 __brelse(bh); 215 spin_lock(&journal->j_list_lock); 216 goto restart; 217 } 218 if (unlikely(buffer_write_io_error(bh))) 219 ret = -EIO; 220 221 /* 222 * Now in whatever state the buffer currently is, we know that 223 * it has been written out and so we can drop it from the list 224 */ 225 released = __jbd2_journal_remove_checkpoint(jh); 226 jbd_unlock_bh_state(bh); 227 jbd2_journal_remove_journal_head(bh); 228 __brelse(bh); 229 } 230 231 return ret; 232 } 233 234 #define NR_BATCH 64 235 236 static void 237 __flush_batch(journal_t *journal, struct buffer_head **bhs, int *batch_count) 238 { 239 int i; 240 241 ll_rw_block(SWRITE, *batch_count, bhs); 242 for (i = 0; i < *batch_count; i++) { 243 struct buffer_head *bh = bhs[i]; 244 clear_buffer_jwrite(bh); 245 BUFFER_TRACE(bh, "brelse"); 246 __brelse(bh); 247 } 248 *batch_count = 0; 249 } 250 251 /* 252 * Try to flush one buffer from the checkpoint list to disk. 253 * 254 * Return 1 if something happened which requires us to abort the current 255 * scan of the checkpoint list. Return <0 if the buffer has failed to 256 * be written out. 257 * 258 * Called with j_list_lock held and drops it if 1 is returned 259 * Called under jbd_lock_bh_state(jh2bh(jh)), and drops it 260 */ 261 static int __process_buffer(journal_t *journal, struct journal_head *jh, 262 struct buffer_head **bhs, int *batch_count, 263 transaction_t *transaction) 264 { 265 struct buffer_head *bh = jh2bh(jh); 266 int ret = 0; 267 268 if (buffer_locked(bh)) { 269 atomic_inc(&bh->b_count); 270 spin_unlock(&journal->j_list_lock); 271 jbd_unlock_bh_state(bh); 272 wait_on_buffer(bh); 273 /* the journal_head may have gone by now */ 274 BUFFER_TRACE(bh, "brelse"); 275 __brelse(bh); 276 ret = 1; 277 } else if (jh->b_transaction != NULL) { 278 transaction_t *t = jh->b_transaction; 279 tid_t tid = t->t_tid; 280 281 transaction->t_chp_stats.cs_forced_to_close++; 282 spin_unlock(&journal->j_list_lock); 283 jbd_unlock_bh_state(bh); 284 jbd2_log_start_commit(journal, tid); 285 jbd2_log_wait_commit(journal, tid); 286 ret = 1; 287 } else if (!buffer_dirty(bh)) { 288 ret = 1; 289 if (unlikely(buffer_write_io_error(bh))) 290 ret = -EIO; 291 J_ASSERT_JH(jh, !buffer_jbddirty(bh)); 292 BUFFER_TRACE(bh, "remove from checkpoint"); 293 __jbd2_journal_remove_checkpoint(jh); 294 spin_unlock(&journal->j_list_lock); 295 jbd_unlock_bh_state(bh); 296 jbd2_journal_remove_journal_head(bh); 297 __brelse(bh); 298 } else { 299 /* 300 * Important: we are about to write the buffer, and 301 * possibly block, while still holding the journal lock. 302 * We cannot afford to let the transaction logic start 303 * messing around with this buffer before we write it to 304 * disk, as that would break recoverability. 305 */ 306 BUFFER_TRACE(bh, "queue"); 307 get_bh(bh); 308 J_ASSERT_BH(bh, !buffer_jwrite(bh)); 309 set_buffer_jwrite(bh); 310 bhs[*batch_count] = bh; 311 __buffer_relink_io(jh); 312 jbd_unlock_bh_state(bh); 313 transaction->t_chp_stats.cs_written++; 314 (*batch_count)++; 315 if (*batch_count == NR_BATCH) { 316 spin_unlock(&journal->j_list_lock); 317 __flush_batch(journal, bhs, batch_count); 318 ret = 1; 319 } 320 } 321 return ret; 322 } 323 324 /* 325 * Perform an actual checkpoint. We take the first transaction on the 326 * list of transactions to be checkpointed and send all its buffers 327 * to disk. We submit larger chunks of data at once. 328 * 329 * The journal should be locked before calling this function. 330 * Called with j_checkpoint_mutex held. 331 */ 332 int jbd2_log_do_checkpoint(journal_t *journal) 333 { 334 transaction_t *transaction; 335 tid_t this_tid; 336 int result; 337 338 jbd_debug(1, "Start checkpoint\n"); 339 340 /* 341 * First thing: if there are any transactions in the log which 342 * don't need checkpointing, just eliminate them from the 343 * journal straight away. 344 */ 345 result = jbd2_cleanup_journal_tail(journal); 346 trace_mark(jbd2_checkpoint, "dev %s need_checkpoint %d", 347 journal->j_devname, result); 348 jbd_debug(1, "cleanup_journal_tail returned %d\n", result); 349 if (result <= 0) 350 return result; 351 352 /* 353 * OK, we need to start writing disk blocks. Take one transaction 354 * and write it. 355 */ 356 result = 0; 357 spin_lock(&journal->j_list_lock); 358 if (!journal->j_checkpoint_transactions) 359 goto out; 360 transaction = journal->j_checkpoint_transactions; 361 if (transaction->t_chp_stats.cs_chp_time == 0) 362 transaction->t_chp_stats.cs_chp_time = jiffies; 363 this_tid = transaction->t_tid; 364 restart: 365 /* 366 * If someone cleaned up this transaction while we slept, we're 367 * done (maybe it's a new transaction, but it fell at the same 368 * address). 369 */ 370 if (journal->j_checkpoint_transactions == transaction && 371 transaction->t_tid == this_tid) { 372 int batch_count = 0; 373 struct buffer_head *bhs[NR_BATCH]; 374 struct journal_head *jh; 375 int retry = 0, err; 376 377 while (!retry && transaction->t_checkpoint_list) { 378 struct buffer_head *bh; 379 380 jh = transaction->t_checkpoint_list; 381 bh = jh2bh(jh); 382 if (!jbd_trylock_bh_state(bh)) { 383 jbd_sync_bh(journal, bh); 384 retry = 1; 385 break; 386 } 387 retry = __process_buffer(journal, jh, bhs, &batch_count, 388 transaction); 389 if (retry < 0 && !result) 390 result = retry; 391 if (!retry && (need_resched() || 392 spin_needbreak(&journal->j_list_lock))) { 393 spin_unlock(&journal->j_list_lock); 394 retry = 1; 395 break; 396 } 397 } 398 399 if (batch_count) { 400 if (!retry) { 401 spin_unlock(&journal->j_list_lock); 402 retry = 1; 403 } 404 __flush_batch(journal, bhs, &batch_count); 405 } 406 407 if (retry) { 408 spin_lock(&journal->j_list_lock); 409 goto restart; 410 } 411 /* 412 * Now we have cleaned up the first transaction's checkpoint 413 * list. Let's clean up the second one 414 */ 415 err = __wait_cp_io(journal, transaction); 416 if (!result) 417 result = err; 418 } 419 out: 420 spin_unlock(&journal->j_list_lock); 421 if (result < 0) 422 jbd2_journal_abort(journal, result); 423 else 424 result = jbd2_cleanup_journal_tail(journal); 425 426 return (result < 0) ? result : 0; 427 } 428 429 /* 430 * Check the list of checkpoint transactions for the journal to see if 431 * we have already got rid of any since the last update of the log tail 432 * in the journal superblock. If so, we can instantly roll the 433 * superblock forward to remove those transactions from the log. 434 * 435 * Return <0 on error, 0 on success, 1 if there was nothing to clean up. 436 * 437 * Called with the journal lock held. 438 * 439 * This is the only part of the journaling code which really needs to be 440 * aware of transaction aborts. Checkpointing involves writing to the 441 * main filesystem area rather than to the journal, so it can proceed 442 * even in abort state, but we must not update the super block if 443 * checkpointing may have failed. Otherwise, we would lose some metadata 444 * buffers which should be written-back to the filesystem. 445 */ 446 447 int jbd2_cleanup_journal_tail(journal_t *journal) 448 { 449 transaction_t * transaction; 450 tid_t first_tid; 451 unsigned long blocknr, freed; 452 453 if (is_journal_aborted(journal)) 454 return 1; 455 456 /* OK, work out the oldest transaction remaining in the log, and 457 * the log block it starts at. 458 * 459 * If the log is now empty, we need to work out which is the 460 * next transaction ID we will write, and where it will 461 * start. */ 462 463 spin_lock(&journal->j_state_lock); 464 spin_lock(&journal->j_list_lock); 465 transaction = journal->j_checkpoint_transactions; 466 if (transaction) { 467 first_tid = transaction->t_tid; 468 blocknr = transaction->t_log_start; 469 } else if ((transaction = journal->j_committing_transaction) != NULL) { 470 first_tid = transaction->t_tid; 471 blocknr = transaction->t_log_start; 472 } else if ((transaction = journal->j_running_transaction) != NULL) { 473 first_tid = transaction->t_tid; 474 blocknr = journal->j_head; 475 } else { 476 first_tid = journal->j_transaction_sequence; 477 blocknr = journal->j_head; 478 } 479 spin_unlock(&journal->j_list_lock); 480 J_ASSERT(blocknr != 0); 481 482 /* If the oldest pinned transaction is at the tail of the log 483 already then there's not much we can do right now. */ 484 if (journal->j_tail_sequence == first_tid) { 485 spin_unlock(&journal->j_state_lock); 486 return 1; 487 } 488 489 /* OK, update the superblock to recover the freed space. 490 * Physical blocks come first: have we wrapped beyond the end of 491 * the log? */ 492 freed = blocknr - journal->j_tail; 493 if (blocknr < journal->j_tail) 494 freed = freed + journal->j_last - journal->j_first; 495 496 jbd_debug(1, 497 "Cleaning journal tail from %d to %d (offset %lu), " 498 "freeing %lu\n", 499 journal->j_tail_sequence, first_tid, blocknr, freed); 500 501 journal->j_free += freed; 502 journal->j_tail_sequence = first_tid; 503 journal->j_tail = blocknr; 504 spin_unlock(&journal->j_state_lock); 505 if (!(journal->j_flags & JBD2_ABORT)) 506 jbd2_journal_update_superblock(journal, 1); 507 return 0; 508 } 509 510 511 /* Checkpoint list management */ 512 513 /* 514 * journal_clean_one_cp_list 515 * 516 * Find all the written-back checkpoint buffers in the given list and release them. 517 * 518 * Called with the journal locked. 519 * Called with j_list_lock held. 520 * Returns number of bufers reaped (for debug) 521 */ 522 523 static int journal_clean_one_cp_list(struct journal_head *jh, int *released) 524 { 525 struct journal_head *last_jh; 526 struct journal_head *next_jh = jh; 527 int ret, freed = 0; 528 529 *released = 0; 530 if (!jh) 531 return 0; 532 533 last_jh = jh->b_cpprev; 534 do { 535 jh = next_jh; 536 next_jh = jh->b_cpnext; 537 /* Use trylock because of the ranking */ 538 if (jbd_trylock_bh_state(jh2bh(jh))) { 539 ret = __try_to_free_cp_buf(jh); 540 if (ret) { 541 freed++; 542 if (ret == 2) { 543 *released = 1; 544 return freed; 545 } 546 } 547 } 548 /* 549 * This function only frees up some memory 550 * if possible so we dont have an obligation 551 * to finish processing. Bail out if preemption 552 * requested: 553 */ 554 if (need_resched()) 555 return freed; 556 } while (jh != last_jh); 557 558 return freed; 559 } 560 561 /* 562 * journal_clean_checkpoint_list 563 * 564 * Find all the written-back checkpoint buffers in the journal and release them. 565 * 566 * Called with the journal locked. 567 * Called with j_list_lock held. 568 * Returns number of buffers reaped (for debug) 569 */ 570 571 int __jbd2_journal_clean_checkpoint_list(journal_t *journal) 572 { 573 transaction_t *transaction, *last_transaction, *next_transaction; 574 int ret = 0; 575 int released; 576 577 transaction = journal->j_checkpoint_transactions; 578 if (!transaction) 579 goto out; 580 581 last_transaction = transaction->t_cpprev; 582 next_transaction = transaction; 583 do { 584 transaction = next_transaction; 585 next_transaction = transaction->t_cpnext; 586 ret += journal_clean_one_cp_list(transaction-> 587 t_checkpoint_list, &released); 588 /* 589 * This function only frees up some memory if possible so we 590 * dont have an obligation to finish processing. Bail out if 591 * preemption requested: 592 */ 593 if (need_resched()) 594 goto out; 595 if (released) 596 continue; 597 /* 598 * It is essential that we are as careful as in the case of 599 * t_checkpoint_list with removing the buffer from the list as 600 * we can possibly see not yet submitted buffers on io_list 601 */ 602 ret += journal_clean_one_cp_list(transaction-> 603 t_checkpoint_io_list, &released); 604 if (need_resched()) 605 goto out; 606 } while (transaction != last_transaction); 607 out: 608 return ret; 609 } 610 611 /* 612 * journal_remove_checkpoint: called after a buffer has been committed 613 * to disk (either by being write-back flushed to disk, or being 614 * committed to the log). 615 * 616 * We cannot safely clean a transaction out of the log until all of the 617 * buffer updates committed in that transaction have safely been stored 618 * elsewhere on disk. To achieve this, all of the buffers in a 619 * transaction need to be maintained on the transaction's checkpoint 620 * lists until they have been rewritten, at which point this function is 621 * called to remove the buffer from the existing transaction's 622 * checkpoint lists. 623 * 624 * The function returns 1 if it frees the transaction, 0 otherwise. 625 * 626 * This function is called with the journal locked. 627 * This function is called with j_list_lock held. 628 * This function is called with jbd_lock_bh_state(jh2bh(jh)) 629 */ 630 631 int __jbd2_journal_remove_checkpoint(struct journal_head *jh) 632 { 633 transaction_t *transaction; 634 journal_t *journal; 635 int ret = 0; 636 637 JBUFFER_TRACE(jh, "entry"); 638 639 if ((transaction = jh->b_cp_transaction) == NULL) { 640 JBUFFER_TRACE(jh, "not on transaction"); 641 goto out; 642 } 643 journal = transaction->t_journal; 644 645 __buffer_unlink(jh); 646 jh->b_cp_transaction = NULL; 647 648 if (transaction->t_checkpoint_list != NULL || 649 transaction->t_checkpoint_io_list != NULL) 650 goto out; 651 JBUFFER_TRACE(jh, "transaction has no more buffers"); 652 653 /* 654 * There is one special case to worry about: if we have just pulled the 655 * buffer off a running or committing transaction's checkpoing list, 656 * then even if the checkpoint list is empty, the transaction obviously 657 * cannot be dropped! 658 * 659 * The locking here around t_state is a bit sleazy. 660 * See the comment at the end of jbd2_journal_commit_transaction(). 661 */ 662 if (transaction->t_state != T_FINISHED) { 663 JBUFFER_TRACE(jh, "belongs to running/committing transaction"); 664 goto out; 665 } 666 667 /* OK, that was the last buffer for the transaction: we can now 668 safely remove this transaction from the log */ 669 670 __jbd2_journal_drop_transaction(journal, transaction); 671 672 /* Just in case anybody was waiting for more transactions to be 673 checkpointed... */ 674 wake_up(&journal->j_wait_logspace); 675 ret = 1; 676 out: 677 JBUFFER_TRACE(jh, "exit"); 678 return ret; 679 } 680 681 /* 682 * journal_insert_checkpoint: put a committed buffer onto a checkpoint 683 * list so that we know when it is safe to clean the transaction out of 684 * the log. 685 * 686 * Called with the journal locked. 687 * Called with j_list_lock held. 688 */ 689 void __jbd2_journal_insert_checkpoint(struct journal_head *jh, 690 transaction_t *transaction) 691 { 692 JBUFFER_TRACE(jh, "entry"); 693 J_ASSERT_JH(jh, buffer_dirty(jh2bh(jh)) || buffer_jbddirty(jh2bh(jh))); 694 J_ASSERT_JH(jh, jh->b_cp_transaction == NULL); 695 696 jh->b_cp_transaction = transaction; 697 698 if (!transaction->t_checkpoint_list) { 699 jh->b_cpnext = jh->b_cpprev = jh; 700 } else { 701 jh->b_cpnext = transaction->t_checkpoint_list; 702 jh->b_cpprev = transaction->t_checkpoint_list->b_cpprev; 703 jh->b_cpprev->b_cpnext = jh; 704 jh->b_cpnext->b_cpprev = jh; 705 } 706 transaction->t_checkpoint_list = jh; 707 } 708 709 /* 710 * We've finished with this transaction structure: adios... 711 * 712 * The transaction must have no links except for the checkpoint by this 713 * point. 714 * 715 * Called with the journal locked. 716 * Called with j_list_lock held. 717 */ 718 719 void __jbd2_journal_drop_transaction(journal_t *journal, transaction_t *transaction) 720 { 721 assert_spin_locked(&journal->j_list_lock); 722 if (transaction->t_cpnext) { 723 transaction->t_cpnext->t_cpprev = transaction->t_cpprev; 724 transaction->t_cpprev->t_cpnext = transaction->t_cpnext; 725 if (journal->j_checkpoint_transactions == transaction) 726 journal->j_checkpoint_transactions = 727 transaction->t_cpnext; 728 if (journal->j_checkpoint_transactions == transaction) 729 journal->j_checkpoint_transactions = NULL; 730 } 731 732 J_ASSERT(transaction->t_state == T_FINISHED); 733 J_ASSERT(transaction->t_buffers == NULL); 734 J_ASSERT(transaction->t_forget == NULL); 735 J_ASSERT(transaction->t_iobuf_list == NULL); 736 J_ASSERT(transaction->t_shadow_list == NULL); 737 J_ASSERT(transaction->t_log_list == NULL); 738 J_ASSERT(transaction->t_checkpoint_list == NULL); 739 J_ASSERT(transaction->t_checkpoint_io_list == NULL); 740 J_ASSERT(transaction->t_updates == 0); 741 J_ASSERT(journal->j_committing_transaction != transaction); 742 J_ASSERT(journal->j_running_transaction != transaction); 743 744 jbd_debug(1, "Dropping transaction %d, all done\n", transaction->t_tid); 745 kfree(transaction); 746 } 747