User: | Jiri Slaby |
Error type: | Double Lock |
Error type description: | Some lock is locked twice unintentionally in a sequence |
File location: | fs/jbd/checkpoint.c |
Line in file: | 416 |
Project: | Linux Kernel |
Project version: | 2.6.28 |
Tools: |
Stanse
(1.2)
Clang Static Analyzer (3.0) Smatch (1.59) |
Entered: | 2011-11-07 22:19:59 UTC |
1/* 2 * linux/fs/jbd/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/jbd.h> 23#include <linux/errno.h> 24#include <linux/slab.h> 25 26/* 27 * Unlink a buffer from a transaction checkpoint list. 28 * 29 * Called with j_list_lock held. 30 */ 31static inline void __buffer_unlink_first(struct journal_head *jh) 32{ 33 transaction_t *transaction = jh->b_cp_transaction; 34 35 jh->b_cpnext->b_cpprev = jh->b_cpprev; 36 jh->b_cpprev->b_cpnext = jh->b_cpnext; 37 if (transaction->t_checkpoint_list == jh) { 38 transaction->t_checkpoint_list = jh->b_cpnext; 39 if (transaction->t_checkpoint_list == jh) 40 transaction->t_checkpoint_list = NULL; 41 } 42} 43 44/* 45 * Unlink a buffer from a transaction checkpoint(io) list. 46 * 47 * Called with j_list_lock held. 48 */ 49static inline void __buffer_unlink(struct journal_head *jh) 50{ 51 transaction_t *transaction = jh->b_cp_transaction; 52 53 __buffer_unlink_first(jh); 54 if (transaction->t_checkpoint_io_list == jh) { 55 transaction->t_checkpoint_io_list = jh->b_cpnext; 56 if (transaction->t_checkpoint_io_list == jh) 57 transaction->t_checkpoint_io_list = NULL; 58 } 59} 60 61/* 62 * Move a buffer from the checkpoint list to the checkpoint io list 63 * 64 * Called with j_list_lock held 65 */ 66static inline void __buffer_relink_io(struct journal_head *jh) 67{ 68 transaction_t *transaction = jh->b_cp_transaction; 69 70 __buffer_unlink_first(jh); 71 72 if (!transaction->t_checkpoint_io_list) { 73 jh->b_cpnext = jh->b_cpprev = jh; 74 } else { 75 jh->b_cpnext = transaction->t_checkpoint_io_list; 76 jh->b_cpprev = transaction->t_checkpoint_io_list->b_cpprev; 77 jh->b_cpprev->b_cpnext = jh; 78 jh->b_cpnext->b_cpprev = jh; 79 } 80 transaction->t_checkpoint_io_list = jh; 81} 82 83/* 84 * Try to release a checkpointed buffer from its transaction. 85 * Returns 1 if we released it and 2 if we also released the 86 * whole transaction. 87 * 88 * Requires j_list_lock 89 * Called under jbd_lock_bh_state(jh2bh(jh)), and drops it 90 */ 91static int __try_to_free_cp_buf(struct journal_head *jh) 92{ 93 int ret = 0; 94 struct buffer_head *bh = jh2bh(jh); 95 96 if (jh->b_jlist == BJ_None && !buffer_locked(bh) && 97 !buffer_dirty(bh) && !buffer_write_io_error(bh)) { 98 JBUFFER_TRACE(jh, "remove from checkpoint list"); 99 ret = __journal_remove_checkpoint(jh) + 1; 100 jbd_unlock_bh_state(bh); 101 journal_remove_journal_head(bh); 102 BUFFER_TRACE(bh, "release"); 103 __brelse(bh); 104 } else { 105 jbd_unlock_bh_state(bh); 106 } 107 return ret; 108} 109 110/* 111 * __log_wait_for_space: wait until there is space in the journal. 112 * 113 * Called under j-state_lock *only*. It will be unlocked if we have to wait 114 * for a checkpoint to free up some space in the log. 115 */ 116void __log_wait_for_space(journal_t *journal) 117{ 118 int nblocks, space_left; 119 assert_spin_locked(&journal->j_state_lock); 120 121 nblocks = jbd_space_needed(journal); 122 while (__log_space_left(journal) < nblocks) { 123 if (journal->j_flags & JFS_ABORT) 124 return; 125 spin_unlock(&journal->j_state_lock); 126 mutex_lock(&journal->j_checkpoint_mutex); 127 128 /* 129 * Test again, another process may have checkpointed while we 130 * were waiting for the checkpoint lock. If there are no 131 * transactions ready to be checkpointed, try to recover 132 * journal space by calling cleanup_journal_tail(), and if 133 * that doesn't work, by waiting for the currently committing 134 * transaction to complete. If there is absolutely no way 135 * to make progress, this is either a BUG or corrupted 136 * filesystem, so abort the journal and leave a stack 137 * trace for forensic evidence. 138 */ 139 spin_lock(&journal->j_state_lock); 140 spin_lock(&journal->j_list_lock); 141 nblocks = jbd_space_needed(journal); 142 space_left = __log_space_left(journal); 143 if (space_left < nblocks) { 144 int chkpt = journal->j_checkpoint_transactions != NULL; 145 tid_t tid = 0; 146 147 if (journal->j_committing_transaction) 148 tid = journal->j_committing_transaction->t_tid; 149 spin_unlock(&journal->j_list_lock); 150 spin_unlock(&journal->j_state_lock); 151 if (chkpt) { 152 log_do_checkpoint(journal); 153 } else if (cleanup_journal_tail(journal) == 0) { 154 /* We were able to recover space; yay! */ 155 ; 156 } else if (tid) { 157 log_wait_commit(journal, tid); 158 } else { 159 printk(KERN_ERR "%s: needed %d blocks and " 160 "only had %d space available\n", 161 __func__, nblocks, space_left); 162 printk(KERN_ERR "%s: no way to get more " 163 "journal space\n", __func__); 164 WARN_ON(1); 165 journal_abort(journal, 0); 166 } 167 spin_lock(&journal->j_state_lock); 168 } else { 169 spin_unlock(&journal->j_list_lock); 170 } 171 mutex_unlock(&journal->j_checkpoint_mutex); 172 } 173} 174 175/* 176 * We were unable to perform jbd_trylock_bh_state() inside j_list_lock. 177 * The caller must restart a list walk. Wait for someone else to run 178 * jbd_unlock_bh_state(). 179 */ 180static void jbd_sync_bh(journal_t *journal, struct buffer_head *bh) 181 __releases(journal->j_list_lock) 182{ 183 get_bh(bh); 184 spin_unlock(&journal->j_list_lock); 185 jbd_lock_bh_state(bh); 186 jbd_unlock_bh_state(bh); 187 put_bh(bh); 188} 189 190/* 191 * Clean up transaction's list of buffers submitted for io. 192 * We wait for any pending IO to complete and remove any clean 193 * buffers. Note that we take the buffers in the opposite ordering 194 * from the one in which they were submitted for IO. 195 * 196 * Return 0 on success, and return <0 if some buffers have failed 197 * to be written out. 198 * 199 * Called with j_list_lock held. 200 */ 201static int __wait_cp_io(journal_t *journal, transaction_t *transaction) 202{ 203 struct journal_head *jh; 204 struct buffer_head *bh; 205 tid_t this_tid; 206 int released = 0; 207 int ret = 0; 208 209 this_tid = transaction->t_tid; 210restart: 211 /* Did somebody clean up the transaction in the meanwhile? */ 212 if (journal->j_checkpoint_transactions != transaction || 213 transaction->t_tid != this_tid) 214 return ret; 215 while (!released && transaction->t_checkpoint_io_list) { 216 jh = transaction->t_checkpoint_io_list; 217 bh = jh2bh(jh); 218 if (!jbd_trylock_bh_state(bh)) { 219 jbd_sync_bh(journal, bh); 220 spin_lock(&journal->j_list_lock); 221 goto restart; 222 } 223 if (buffer_locked(bh)) { 224 atomic_inc(&bh->b_count); 225 spin_unlock(&journal->j_list_lock); 226 jbd_unlock_bh_state(bh); 227 wait_on_buffer(bh); 228 /* the journal_head may have gone by now */ 229 BUFFER_TRACE(bh, "brelse"); 230 __brelse(bh); 231 spin_lock(&journal->j_list_lock); 232 goto restart; 233 } 234 if (unlikely(buffer_write_io_error(bh))) 235 ret = -EIO; 236 237 /* 238 * Now in whatever state the buffer currently is, we know that 239 * it has been written out and so we can drop it from the list 240 */ 241 released = __journal_remove_checkpoint(jh); 242 jbd_unlock_bh_state(bh); 243 journal_remove_journal_head(bh); 244 __brelse(bh); 245 } 246 247 return ret; 248} 249 250#define NR_BATCH 64 251 252static void 253__flush_batch(journal_t *journal, struct buffer_head **bhs, int *batch_count) 254{ 255 int i; 256 257 ll_rw_block(SWRITE, *batch_count, bhs); 258 for (i = 0; i < *batch_count; i++) { 259 struct buffer_head *bh = bhs[i]; 260 clear_buffer_jwrite(bh); 261 BUFFER_TRACE(bh, "brelse"); 262 __brelse(bh); 263 } 264 *batch_count = 0; 265} 266 267/* 268 * Try to flush one buffer from the checkpoint list to disk. 269 * 270 * Return 1 if something happened which requires us to abort the current 271 * scan of the checkpoint list. Return <0 if the buffer has failed to 272 * be written out. 273 * 274 * Called with j_list_lock held and drops it if 1 is returned 275 * Called under jbd_lock_bh_state(jh2bh(jh)), and drops it 276 */ 277static int __process_buffer(journal_t *journal, struct journal_head *jh, 278 struct buffer_head **bhs, int *batch_count) 279{ 280 struct buffer_head *bh = jh2bh(jh); 281 int ret = 0; 282 283 if (buffer_locked(bh)) { 284 atomic_inc(&bh->b_count); 285 spin_unlock(&journal->j_list_lock); 286 jbd_unlock_bh_state(bh); 287 wait_on_buffer(bh); 288 /* the journal_head may have gone by now */ 289 BUFFER_TRACE(bh, "brelse"); 290 __brelse(bh); 291 ret = 1; 292 } else if (jh->b_transaction != NULL) { 293 transaction_t *t = jh->b_transaction; 294 tid_t tid = t->t_tid; 295 296 spin_unlock(&journal->j_list_lock); 297 jbd_unlock_bh_state(bh); 298 log_start_commit(journal, tid); 299 log_wait_commit(journal, tid); 300 ret = 1; 301 } else if (!buffer_dirty(bh)) { 302 ret = 1; 303 if (unlikely(buffer_write_io_error(bh))) 304 ret = -EIO; 305 J_ASSERT_JH(jh, !buffer_jbddirty(bh)); 306 BUFFER_TRACE(bh, "remove from checkpoint"); 307 __journal_remove_checkpoint(jh); 308 spin_unlock(&journal->j_list_lock); 309 jbd_unlock_bh_state(bh); 310 journal_remove_journal_head(bh); 311 __brelse(bh); 312 } else { 313 /* 314 * Important: we are about to write the buffer, and 315 * possibly block, while still holding the journal lock. 316 * We cannot afford to let the transaction logic start 317 * messing around with this buffer before we write it to 318 * disk, as that would break recoverability. 319 */ 320 BUFFER_TRACE(bh, "queue"); 321 get_bh(bh); 322 J_ASSERT_BH(bh, !buffer_jwrite(bh)); 323 set_buffer_jwrite(bh); 324 bhs[*batch_count] = bh; 325 __buffer_relink_io(jh); 326 jbd_unlock_bh_state(bh); 327 (*batch_count)++; 328 if (*batch_count == NR_BATCH) { 329 spin_unlock(&journal->j_list_lock); 330 __flush_batch(journal, bhs, batch_count); 331 ret = 1; 332 } 333 } 334 return ret; 335} 336 337/* 338 * Perform an actual checkpoint. We take the first transaction on the 339 * list of transactions to be checkpointed and send all its buffers 340 * to disk. We submit larger chunks of data at once. 341 * 342 * The journal should be locked before calling this function. 343 * Called with j_checkpoint_mutex held. 344 */ 345int log_do_checkpoint(journal_t *journal) 346{ 347 transaction_t *transaction; 348 tid_t this_tid; 349 int result; 350 351 jbd_debug(1, "Start checkpoint\n"); 352 353 /* 354 * First thing: if there are any transactions in the log which 355 * don't need checkpointing, just eliminate them from the 356 * journal straight away. 357 */ 358 result = cleanup_journal_tail(journal); 359 jbd_debug(1, "cleanup_journal_tail returned %d\n", result); 360 if (result <= 0) 361 return result; 362 363 /* 364 * OK, we need to start writing disk blocks. Take one transaction 365 * and write it. 366 */ 367 result = 0; 368 spin_lock(&journal->j_list_lock); 369 if (!journal->j_checkpoint_transactions) 370 goto out; 371 transaction = journal->j_checkpoint_transactions; 372 this_tid = transaction->t_tid; 373restart: 374 /* 375 * If someone cleaned up this transaction while we slept, we're 376 * done (maybe it's a new transaction, but it fell at the same 377 * address). 378 */ 379 if (journal->j_checkpoint_transactions == transaction && 380 transaction->t_tid == this_tid) { 381 int batch_count = 0; 382 struct buffer_head *bhs[NR_BATCH]; 383 struct journal_head *jh; 384 int retry = 0, err; 385 386 while (!retry && transaction->t_checkpoint_list) { 387 struct buffer_head *bh; 388 389 jh = transaction->t_checkpoint_list; 390 bh = jh2bh(jh); 391 if (!jbd_trylock_bh_state(bh)) { 392 jbd_sync_bh(journal, bh); 393 retry = 1; 394 break; 395 } 396 retry = __process_buffer(journal, jh, bhs,&batch_count); 397 if (retry < 0 && !result) 398 result = retry; 399 if (!retry && (need_resched() || 400 spin_needbreak(&journal->j_list_lock))) { 401 spin_unlock(&journal->j_list_lock); 402 retry = 1; 403 break; 404 } 405 } 406 407 if (batch_count) { 408 if (!retry) { 409 spin_unlock(&journal->j_list_lock); 410 retry = 1; 411 } 412 __flush_batch(journal, bhs, &batch_count); 413 } 414 415 if (retry) { 416 spin_lock(&journal->j_list_lock); 417 goto restart; 418 } 419 /* 420 * Now we have cleaned up the first transaction's checkpoint 421 * list. Let's clean up the second one 422 */ 423 err = __wait_cp_io(journal, transaction); 424 if (!result) 425 result = err; 426 } 427out: 428 spin_unlock(&journal->j_list_lock); 429 if (result < 0) 430 journal_abort(journal, result); 431 else 432 result = cleanup_journal_tail(journal); 433 434 return (result < 0) ? result : 0; 435} 436 437/* 438 * Check the list of checkpoint transactions for the journal to see if 439 * we have already got rid of any since the last update of the log tail 440 * in the journal superblock. If so, we can instantly roll the 441 * superblock forward to remove those transactions from the log. 442 * 443 * Return <0 on error, 0 on success, 1 if there was nothing to clean up. 444 * 445 * Called with the journal lock held. 446 * 447 * This is the only part of the journaling code which really needs to be 448 * aware of transaction aborts. Checkpointing involves writing to the 449 * main filesystem area rather than to the journal, so it can proceed 450 * even in abort state, but we must not update the super block if 451 * checkpointing may have failed. Otherwise, we would lose some metadata 452 * buffers which should be written-back to the filesystem. 453 */ 454 455int cleanup_journal_tail(journal_t *journal) 456{ 457 transaction_t * transaction; 458 tid_t first_tid; 459 unsigned long blocknr, freed; 460 461 if (is_journal_aborted(journal)) 462 return 1; 463 464 /* OK, work out the oldest transaction remaining in the log, and 465 * the log block it starts at. 466 * 467 * If the log is now empty, we need to work out which is the 468 * next transaction ID we will write, and where it will 469 * start. */ 470 471 spin_lock(&journal->j_state_lock); 472 spin_lock(&journal->j_list_lock); 473 transaction = journal->j_checkpoint_transactions; 474 if (transaction) { 475 first_tid = transaction->t_tid; 476 blocknr = transaction->t_log_start; 477 } else if ((transaction = journal->j_committing_transaction) != NULL) { 478 first_tid = transaction->t_tid; 479 blocknr = transaction->t_log_start; 480 } else if ((transaction = journal->j_running_transaction) != NULL) { 481 first_tid = transaction->t_tid; 482 blocknr = journal->j_head; 483 } else { 484 first_tid = journal->j_transaction_sequence; 485 blocknr = journal->j_head; 486 } 487 spin_unlock(&journal->j_list_lock); 488 J_ASSERT(blocknr != 0); 489 490 /* If the oldest pinned transaction is at the tail of the log 491 already then there's not much we can do right now. */ 492 if (journal->j_tail_sequence == first_tid) { 493 spin_unlock(&journal->j_state_lock); 494 return 1; 495 } 496 497 /* OK, update the superblock to recover the freed space. 498 * Physical blocks come first: have we wrapped beyond the end of 499 * the log? */ 500 freed = blocknr - journal->j_tail; 501 if (blocknr < journal->j_tail) 502 freed = freed + journal->j_last - journal->j_first; 503 504 jbd_debug(1, 505 "Cleaning journal tail from %d to %d (offset %lu), " 506 "freeing %lu\n", 507 journal->j_tail_sequence, first_tid, blocknr, freed); 508 509 journal->j_free += freed; 510 journal->j_tail_sequence = first_tid; 511 journal->j_tail = blocknr; 512 spin_unlock(&journal->j_state_lock); 513 if (!(journal->j_flags & JFS_ABORT)) 514 journal_update_superblock(journal, 1); 515 return 0; 516} 517 518 519/* Checkpoint list management */ 520 521/* 522 * journal_clean_one_cp_list 523 * 524 * Find all the written-back checkpoint buffers in the given list and release them. 525 * 526 * Called with the journal locked. 527 * Called with j_list_lock held. 528 * Returns number of bufers reaped (for debug) 529 */ 530 531static int journal_clean_one_cp_list(struct journal_head *jh, int *released) 532{ 533 struct journal_head *last_jh; 534 struct journal_head *next_jh = jh; 535 int ret, freed = 0; 536 537 *released = 0; 538 if (!jh) 539 return 0; 540 541 last_jh = jh->b_cpprev; 542 do { 543 jh = next_jh; 544 next_jh = jh->b_cpnext; 545 /* Use trylock because of the ranking */ 546 if (jbd_trylock_bh_state(jh2bh(jh))) { 547 ret = __try_to_free_cp_buf(jh); 548 if (ret) { 549 freed++; 550 if (ret == 2) { 551 *released = 1; 552 return freed; 553 } 554 } 555 } 556 /* 557 * This function only frees up some memory 558 * if possible so we dont have an obligation 559 * to finish processing. Bail out if preemption 560 * requested: 561 */ 562 if (need_resched()) 563 return freed; 564 } while (jh != last_jh); 565 566 return freed; 567} 568 569/* 570 * journal_clean_checkpoint_list 571 * 572 * Find all the written-back checkpoint buffers in the journal and release them. 573 * 574 * Called with the journal locked. 575 * Called with j_list_lock held. 576 * Returns number of buffers reaped (for debug) 577 */ 578 579int __journal_clean_checkpoint_list(journal_t *journal) 580{ 581 transaction_t *transaction, *last_transaction, *next_transaction; 582 int ret = 0; 583 int released; 584 585 transaction = journal->j_checkpoint_transactions; 586 if (!transaction) 587 goto out; 588 589 last_transaction = transaction->t_cpprev; 590 next_transaction = transaction; 591 do { 592 transaction = next_transaction; 593 next_transaction = transaction->t_cpnext; 594 ret += journal_clean_one_cp_list(transaction-> 595 t_checkpoint_list, &released); 596 /* 597 * This function only frees up some memory if possible so we 598 * dont have an obligation to finish processing. Bail out if 599 * preemption requested: 600 */ 601 if (need_resched()) 602 goto out; 603 if (released) 604 continue; 605 /* 606 * It is essential that we are as careful as in the case of 607 * t_checkpoint_list with removing the buffer from the list as 608 * we can possibly see not yet submitted buffers on io_list 609 */ 610 ret += journal_clean_one_cp_list(transaction-> 611 t_checkpoint_io_list, &released); 612 if (need_resched()) 613 goto out; 614 } while (transaction != last_transaction); 615out: 616 return ret; 617} 618 619/* 620 * journal_remove_checkpoint: called after a buffer has been committed 621 * to disk (either by being write-back flushed to disk, or being 622 * committed to the log). 623 * 624 * We cannot safely clean a transaction out of the log until all of the 625 * buffer updates committed in that transaction have safely been stored 626 * elsewhere on disk. To achieve this, all of the buffers in a 627 * transaction need to be maintained on the transaction's checkpoint 628 * lists until they have been rewritten, at which point this function is 629 * called to remove the buffer from the existing transaction's 630 * checkpoint lists. 631 * 632 * The function returns 1 if it frees the transaction, 0 otherwise. 633 * 634 * This function is called with the journal locked. 635 * This function is called with j_list_lock held. 636 * This function is called with jbd_lock_bh_state(jh2bh(jh)) 637 */ 638 639int __journal_remove_checkpoint(struct journal_head *jh) 640{ 641 transaction_t *transaction; 642 journal_t *journal; 643 int ret = 0; 644 645 JBUFFER_TRACE(jh, "entry"); 646 647 if ((transaction = jh->b_cp_transaction) == NULL) { 648 JBUFFER_TRACE(jh, "not on transaction"); 649 goto out; 650 } 651 journal = transaction->t_journal; 652 653 __buffer_unlink(jh); 654 jh->b_cp_transaction = NULL; 655 656 if (transaction->t_checkpoint_list != NULL || 657 transaction->t_checkpoint_io_list != NULL) 658 goto out; 659 JBUFFER_TRACE(jh, "transaction has no more buffers"); 660 661 /* 662 * There is one special case to worry about: if we have just pulled the 663 * buffer off a running or committing transaction's checkpoing list, 664 * then even if the checkpoint list is empty, the transaction obviously 665 * cannot be dropped! 666 * 667 * The locking here around t_state is a bit sleazy. 668 * See the comment at the end of journal_commit_transaction(). 669 */ 670 if (transaction->t_state != T_FINISHED) { 671 JBUFFER_TRACE(jh, "belongs to running/committing transaction"); 672 goto out; 673 } 674 675 /* OK, that was the last buffer for the transaction: we can now 676 safely remove this transaction from the log */ 677 678 __journal_drop_transaction(journal, transaction); 679 680 /* Just in case anybody was waiting for more transactions to be 681 checkpointed... */ 682 wake_up(&journal->j_wait_logspace); 683 ret = 1; 684out: 685 JBUFFER_TRACE(jh, "exit"); 686 return ret; 687} 688 689/* 690 * journal_insert_checkpoint: put a committed buffer onto a checkpoint 691 * list so that we know when it is safe to clean the transaction out of 692 * the log. 693 * 694 * Called with the journal locked. 695 * Called with j_list_lock held. 696 */ 697void __journal_insert_checkpoint(struct journal_head *jh, 698 transaction_t *transaction) 699{ 700 JBUFFER_TRACE(jh, "entry"); 701 J_ASSERT_JH(jh, buffer_dirty(jh2bh(jh)) || buffer_jbddirty(jh2bh(jh))); 702 J_ASSERT_JH(jh, jh->b_cp_transaction == NULL); 703 704 jh->b_cp_transaction = transaction; 705 706 if (!transaction->t_checkpoint_list) { 707 jh->b_cpnext = jh->b_cpprev = jh; 708 } else { 709 jh->b_cpnext = transaction->t_checkpoint_list; 710 jh->b_cpprev = transaction->t_checkpoint_list->b_cpprev; 711 jh->b_cpprev->b_cpnext = jh; 712 jh->b_cpnext->b_cpprev = jh; 713 } 714 transaction->t_checkpoint_list = jh; 715} 716 717/* 718 * We've finished with this transaction structure: adios... 719 * 720 * The transaction must have no links except for the checkpoint by this 721 * point. 722 * 723 * Called with the journal locked. 724 * Called with j_list_lock held. 725 */ 726 727void __journal_drop_transaction(journal_t *journal, transaction_t *transaction) 728{ 729 assert_spin_locked(&journal->j_list_lock); 730 if (transaction->t_cpnext) { 731 transaction->t_cpnext->t_cpprev = transaction->t_cpprev; 732 transaction->t_cpprev->t_cpnext = transaction->t_cpnext; 733 if (journal->j_checkpoint_transactions == transaction) 734 journal->j_checkpoint_transactions = 735 transaction->t_cpnext; 736 if (journal->j_checkpoint_transactions == transaction) 737 journal->j_checkpoint_transactions = NULL; 738 } 739 740 J_ASSERT(transaction->t_state == T_FINISHED); 741 J_ASSERT(transaction->t_buffers == NULL); 742 J_ASSERT(transaction->t_sync_datalist == NULL); 743 J_ASSERT(transaction->t_forget == NULL); 744 J_ASSERT(transaction->t_iobuf_list == NULL); 745 J_ASSERT(transaction->t_shadow_list == NULL); 746 J_ASSERT(transaction->t_log_list == NULL); 747 J_ASSERT(transaction->t_checkpoint_list == NULL); 748 J_ASSERT(transaction->t_checkpoint_io_list == NULL); 749 J_ASSERT(transaction->t_updates == 0); 750 J_ASSERT(journal->j_committing_transaction != transaction); 751 J_ASSERT(journal->j_running_transaction != transaction); 752 753 jbd_debug(1, "Dropping transaction %d, all done\n", transaction->t_tid); 754 kfree(transaction); 755}