1 /* 2 * linux/fs/jbd2/journal.c 3 * 4 * Written by Stephen C. Tweedie <sct@redhat.com>, 1998 5 * 6 * Copyright 1998 Red Hat corp --- 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 * Generic filesystem journal-writing code; part of the ext2fs 13 * journaling system. 14 * 15 * This file manages journals: areas of disk reserved for logging 16 * transactional updates. This includes the kernel journaling thread 17 * which is responsible for scheduling updates to the log. 18 * 19 * We do not actually manage the physical storage of the journal in this 20 * file: that is left to a per-journal policy function, which allows us 21 * to store the journal within a filesystem-specified area for ext2 22 * journaling (ext2 can use a reserved inode for storing the log). 23 */ 24 25 #include <linux/module.h> 26 #include <linux/time.h> 27 #include <linux/fs.h> 28 #include <linux/jbd2.h> 29 #include <linux/errno.h> 30 #include <linux/slab.h> 31 #include <linux/init.h> 32 #include <linux/mm.h> 33 #include <linux/freezer.h> 34 #include <linux/pagemap.h> 35 #include <linux/kthread.h> 36 #include <linux/poison.h> 37 #include <linux/proc_fs.h> 38 #include <linux/seq_file.h> 39 #include <linux/math64.h> 40 #include <linux/hash.h> 41 #include <linux/log2.h> 42 #include <linux/vmalloc.h> 43 #include <linux/backing-dev.h> 44 #include <linux/bitops.h> 45 #include <linux/ratelimit.h> 46 #include <linux/sched/mm.h> 47 48 #define CREATE_TRACE_POINTS 49 #include <trace/events/jbd2.h> 50 51 #include <linux/uaccess.h> 52 #include <asm/page.h> 53 54 #ifdef CONFIG_JBD2_DEBUG 55 ushort jbd2_journal_enable_debug __read_mostly; 56 EXPORT_SYMBOL(jbd2_journal_enable_debug); 57 58 module_param_named(jbd2_debug, jbd2_journal_enable_debug, ushort, 0644); 59 MODULE_PARM_DESC(jbd2_debug, "Debugging level for jbd2"); 60 #endif 61 62 EXPORT_SYMBOL(jbd2_journal_extend); 63 EXPORT_SYMBOL(jbd2_journal_stop); 64 EXPORT_SYMBOL(jbd2_journal_lock_updates); 65 EXPORT_SYMBOL(jbd2_journal_unlock_updates); 66 EXPORT_SYMBOL(jbd2_journal_get_write_access); 67 EXPORT_SYMBOL(jbd2_journal_get_create_access); 68 EXPORT_SYMBOL(jbd2_journal_get_undo_access); 69 EXPORT_SYMBOL(jbd2_journal_set_triggers); 70 EXPORT_SYMBOL(jbd2_journal_dirty_metadata); 71 EXPORT_SYMBOL(jbd2_journal_forget); 72 #if 0 73 EXPORT_SYMBOL(journal_sync_buffer); 74 #endif 75 EXPORT_SYMBOL(jbd2_journal_flush); 76 EXPORT_SYMBOL(jbd2_journal_revoke); 77 78 EXPORT_SYMBOL(jbd2_journal_init_dev); 79 EXPORT_SYMBOL(jbd2_journal_init_inode); 80 EXPORT_SYMBOL(jbd2_journal_check_used_features); 81 EXPORT_SYMBOL(jbd2_journal_check_available_features); 82 EXPORT_SYMBOL(jbd2_journal_set_features); 83 EXPORT_SYMBOL(jbd2_journal_load); 84 EXPORT_SYMBOL(jbd2_journal_destroy); 85 EXPORT_SYMBOL(jbd2_journal_abort); 86 EXPORT_SYMBOL(jbd2_journal_errno); 87 EXPORT_SYMBOL(jbd2_journal_ack_err); 88 EXPORT_SYMBOL(jbd2_journal_clear_err); 89 EXPORT_SYMBOL(jbd2_log_wait_commit); 90 EXPORT_SYMBOL(jbd2_log_start_commit); 91 EXPORT_SYMBOL(jbd2_journal_start_commit); 92 EXPORT_SYMBOL(jbd2_journal_force_commit_nested); 93 EXPORT_SYMBOL(jbd2_journal_wipe); 94 EXPORT_SYMBOL(jbd2_journal_blocks_per_page); 95 EXPORT_SYMBOL(jbd2_journal_invalidatepage); 96 EXPORT_SYMBOL(jbd2_journal_try_to_free_buffers); 97 EXPORT_SYMBOL(jbd2_journal_force_commit); 98 EXPORT_SYMBOL(jbd2_journal_inode_add_write); 99 EXPORT_SYMBOL(jbd2_journal_inode_add_wait); 100 EXPORT_SYMBOL(jbd2_journal_init_jbd_inode); 101 EXPORT_SYMBOL(jbd2_journal_release_jbd_inode); 102 EXPORT_SYMBOL(jbd2_journal_begin_ordered_truncate); 103 EXPORT_SYMBOL(jbd2_inode_cache); 104 105 static void __journal_abort_soft (journal_t *journal, int errno); 106 static int jbd2_journal_create_slab(size_t slab_size); 107 108 #ifdef CONFIG_JBD2_DEBUG 109 void __jbd2_debug(int level, const char *file, const char *func, 110 unsigned int line, const char *fmt, ...) 111 { 112 struct va_format vaf; 113 va_list args; 114 115 if (level > jbd2_journal_enable_debug) 116 return; 117 va_start(args, fmt); 118 vaf.fmt = fmt; 119 vaf.va = &args; 120 printk(KERN_DEBUG "%s: (%s, %u): %pV\n", file, func, line, &vaf); 121 va_end(args); 122 } 123 EXPORT_SYMBOL(__jbd2_debug); 124 #endif 125 126 /* Checksumming functions */ 127 static int jbd2_verify_csum_type(journal_t *j, journal_superblock_t *sb) 128 { 129 if (!jbd2_journal_has_csum_v2or3_feature(j)) 130 return 1; 131 132 return sb->s_checksum_type == JBD2_CRC32C_CHKSUM; 133 } 134 135 static __be32 jbd2_superblock_csum(journal_t *j, journal_superblock_t *sb) 136 { 137 __u32 csum; 138 __be32 old_csum; 139 140 old_csum = sb->s_checksum; 141 sb->s_checksum = 0; 142 csum = jbd2_chksum(j, ~0, (char *)sb, sizeof(journal_superblock_t)); 143 sb->s_checksum = old_csum; 144 145 return cpu_to_be32(csum); 146 } 147 148 static int jbd2_superblock_csum_verify(journal_t *j, journal_superblock_t *sb) 149 { 150 if (!jbd2_journal_has_csum_v2or3(j)) 151 return 1; 152 153 return sb->s_checksum == jbd2_superblock_csum(j, sb); 154 } 155 156 static void jbd2_superblock_csum_set(journal_t *j, journal_superblock_t *sb) 157 { 158 if (!jbd2_journal_has_csum_v2or3(j)) 159 return; 160 161 sb->s_checksum = jbd2_superblock_csum(j, sb); 162 } 163 164 /* 165 * Helper function used to manage commit timeouts 166 */ 167 168 static void commit_timeout(unsigned long __data) 169 { 170 struct task_struct * p = (struct task_struct *) __data; 171 172 wake_up_process(p); 173 } 174 175 /* 176 * kjournald2: The main thread function used to manage a logging device 177 * journal. 178 * 179 * This kernel thread is responsible for two things: 180 * 181 * 1) COMMIT: Every so often we need to commit the current state of the 182 * filesystem to disk. The journal thread is responsible for writing 183 * all of the metadata buffers to disk. 184 * 185 * 2) CHECKPOINT: We cannot reuse a used section of the log file until all 186 * of the data in that part of the log has been rewritten elsewhere on 187 * the disk. Flushing these old buffers to reclaim space in the log is 188 * known as checkpointing, and this thread is responsible for that job. 189 */ 190 191 static int kjournald2(void *arg) 192 { 193 journal_t *journal = arg; 194 transaction_t *transaction; 195 196 /* 197 * Set up an interval timer which can be used to trigger a commit wakeup 198 * after the commit interval expires 199 */ 200 setup_timer(&journal->j_commit_timer, commit_timeout, 201 (unsigned long)current); 202 203 set_freezable(); 204 205 /* Record that the journal thread is running */ 206 journal->j_task = current; 207 wake_up(&journal->j_wait_done_commit); 208 209 /* 210 * Make sure that no allocations from this kernel thread will ever 211 * recurse to the fs layer because we are responsible for the 212 * transaction commit and any fs involvement might get stuck waiting for 213 * the trasn. commit. 214 */ 215 memalloc_nofs_save(); 216 217 /* 218 * And now, wait forever for commit wakeup events. 219 */ 220 write_lock(&journal->j_state_lock); 221 222 loop: 223 if (journal->j_flags & JBD2_UNMOUNT) 224 goto end_loop; 225 226 jbd_debug(1, "commit_sequence=%d, commit_request=%d\n", 227 journal->j_commit_sequence, journal->j_commit_request); 228 229 if (journal->j_commit_sequence != journal->j_commit_request) { 230 jbd_debug(1, "OK, requests differ\n"); 231 write_unlock(&journal->j_state_lock); 232 del_timer_sync(&journal->j_commit_timer); 233 jbd2_journal_commit_transaction(journal); 234 write_lock(&journal->j_state_lock); 235 goto loop; 236 } 237 238 wake_up(&journal->j_wait_done_commit); 239 if (freezing(current)) { 240 /* 241 * The simpler the better. Flushing journal isn't a 242 * good idea, because that depends on threads that may 243 * be already stopped. 244 */ 245 jbd_debug(1, "Now suspending kjournald2\n"); 246 write_unlock(&journal->j_state_lock); 247 try_to_freeze(); 248 write_lock(&journal->j_state_lock); 249 } else { 250 /* 251 * We assume on resume that commits are already there, 252 * so we don't sleep 253 */ 254 DEFINE_WAIT(wait); 255 int should_sleep = 1; 256 257 prepare_to_wait(&journal->j_wait_commit, &wait, 258 TASK_INTERRUPTIBLE); 259 if (journal->j_commit_sequence != journal->j_commit_request) 260 should_sleep = 0; 261 transaction = journal->j_running_transaction; 262 if (transaction && time_after_eq(jiffies, 263 transaction->t_expires)) 264 should_sleep = 0; 265 if (journal->j_flags & JBD2_UNMOUNT) 266 should_sleep = 0; 267 if (should_sleep) { 268 write_unlock(&journal->j_state_lock); 269 schedule(); 270 write_lock(&journal->j_state_lock); 271 } 272 finish_wait(&journal->j_wait_commit, &wait); 273 } 274 275 jbd_debug(1, "kjournald2 wakes\n"); 276 277 /* 278 * Were we woken up by a commit wakeup event? 279 */ 280 transaction = journal->j_running_transaction; 281 if (transaction && time_after_eq(jiffies, transaction->t_expires)) { 282 journal->j_commit_request = transaction->t_tid; 283 jbd_debug(1, "woke because of timeout\n"); 284 } 285 goto loop; 286 287 end_loop: 288 del_timer_sync(&journal->j_commit_timer); 289 journal->j_task = NULL; 290 wake_up(&journal->j_wait_done_commit); 291 jbd_debug(1, "Journal thread exiting.\n"); 292 write_unlock(&journal->j_state_lock); 293 return 0; 294 } 295 296 static int jbd2_journal_start_thread(journal_t *journal) 297 { 298 struct task_struct *t; 299 300 t = kthread_run(kjournald2, journal, "jbd2/%s", 301 journal->j_devname); 302 if (IS_ERR(t)) 303 return PTR_ERR(t); 304 305 wait_event(journal->j_wait_done_commit, journal->j_task != NULL); 306 return 0; 307 } 308 309 static void journal_kill_thread(journal_t *journal) 310 { 311 write_lock(&journal->j_state_lock); 312 journal->j_flags |= JBD2_UNMOUNT; 313 314 while (journal->j_task) { 315 write_unlock(&journal->j_state_lock); 316 wake_up(&journal->j_wait_commit); 317 wait_event(journal->j_wait_done_commit, journal->j_task == NULL); 318 write_lock(&journal->j_state_lock); 319 } 320 write_unlock(&journal->j_state_lock); 321 } 322 323 /* 324 * jbd2_journal_write_metadata_buffer: write a metadata buffer to the journal. 325 * 326 * Writes a metadata buffer to a given disk block. The actual IO is not 327 * performed but a new buffer_head is constructed which labels the data 328 * to be written with the correct destination disk block. 329 * 330 * Any magic-number escaping which needs to be done will cause a 331 * copy-out here. If the buffer happens to start with the 332 * JBD2_MAGIC_NUMBER, then we can't write it to the log directly: the 333 * magic number is only written to the log for descripter blocks. In 334 * this case, we copy the data and replace the first word with 0, and we 335 * return a result code which indicates that this buffer needs to be 336 * marked as an escaped buffer in the corresponding log descriptor 337 * block. The missing word can then be restored when the block is read 338 * during recovery. 339 * 340 * If the source buffer has already been modified by a new transaction 341 * since we took the last commit snapshot, we use the frozen copy of 342 * that data for IO. If we end up using the existing buffer_head's data 343 * for the write, then we have to make sure nobody modifies it while the 344 * IO is in progress. do_get_write_access() handles this. 345 * 346 * The function returns a pointer to the buffer_head to be used for IO. 347 * 348 * 349 * Return value: 350 * <0: Error 351 * >=0: Finished OK 352 * 353 * On success: 354 * Bit 0 set == escape performed on the data 355 * Bit 1 set == buffer copy-out performed (kfree the data after IO) 356 */ 357 358 int jbd2_journal_write_metadata_buffer(transaction_t *transaction, 359 struct journal_head *jh_in, 360 struct buffer_head **bh_out, 361 sector_t blocknr) 362 { 363 int need_copy_out = 0; 364 int done_copy_out = 0; 365 int do_escape = 0; 366 char *mapped_data; 367 struct buffer_head *new_bh; 368 struct page *new_page; 369 unsigned int new_offset; 370 struct buffer_head *bh_in = jh2bh(jh_in); 371 journal_t *journal = transaction->t_journal; 372 373 /* 374 * The buffer really shouldn't be locked: only the current committing 375 * transaction is allowed to write it, so nobody else is allowed 376 * to do any IO. 377 * 378 * akpm: except if we're journalling data, and write() output is 379 * also part of a shared mapping, and another thread has 380 * decided to launch a writepage() against this buffer. 381 */ 382 J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in)); 383 384 new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL); 385 386 /* keep subsequent assertions sane */ 387 atomic_set(&new_bh->b_count, 1); 388 389 jbd_lock_bh_state(bh_in); 390 repeat: 391 /* 392 * If a new transaction has already done a buffer copy-out, then 393 * we use that version of the data for the commit. 394 */ 395 if (jh_in->b_frozen_data) { 396 done_copy_out = 1; 397 new_page = virt_to_page(jh_in->b_frozen_data); 398 new_offset = offset_in_page(jh_in->b_frozen_data); 399 } else { 400 new_page = jh2bh(jh_in)->b_page; 401 new_offset = offset_in_page(jh2bh(jh_in)->b_data); 402 } 403 404 mapped_data = kmap_atomic(new_page); 405 /* 406 * Fire data frozen trigger if data already wasn't frozen. Do this 407 * before checking for escaping, as the trigger may modify the magic 408 * offset. If a copy-out happens afterwards, it will have the correct 409 * data in the buffer. 410 */ 411 if (!done_copy_out) 412 jbd2_buffer_frozen_trigger(jh_in, mapped_data + new_offset, 413 jh_in->b_triggers); 414 415 /* 416 * Check for escaping 417 */ 418 if (*((__be32 *)(mapped_data + new_offset)) == 419 cpu_to_be32(JBD2_MAGIC_NUMBER)) { 420 need_copy_out = 1; 421 do_escape = 1; 422 } 423 kunmap_atomic(mapped_data); 424 425 /* 426 * Do we need to do a data copy? 427 */ 428 if (need_copy_out && !done_copy_out) { 429 char *tmp; 430 431 jbd_unlock_bh_state(bh_in); 432 tmp = jbd2_alloc(bh_in->b_size, GFP_NOFS); 433 if (!tmp) { 434 brelse(new_bh); 435 return -ENOMEM; 436 } 437 jbd_lock_bh_state(bh_in); 438 if (jh_in->b_frozen_data) { 439 jbd2_free(tmp, bh_in->b_size); 440 goto repeat; 441 } 442 443 jh_in->b_frozen_data = tmp; 444 mapped_data = kmap_atomic(new_page); 445 memcpy(tmp, mapped_data + new_offset, bh_in->b_size); 446 kunmap_atomic(mapped_data); 447 448 new_page = virt_to_page(tmp); 449 new_offset = offset_in_page(tmp); 450 done_copy_out = 1; 451 452 /* 453 * This isn't strictly necessary, as we're using frozen 454 * data for the escaping, but it keeps consistency with 455 * b_frozen_data usage. 456 */ 457 jh_in->b_frozen_triggers = jh_in->b_triggers; 458 } 459 460 /* 461 * Did we need to do an escaping? Now we've done all the 462 * copying, we can finally do so. 463 */ 464 if (do_escape) { 465 mapped_data = kmap_atomic(new_page); 466 *((unsigned int *)(mapped_data + new_offset)) = 0; 467 kunmap_atomic(mapped_data); 468 } 469 470 set_bh_page(new_bh, new_page, new_offset); 471 new_bh->b_size = bh_in->b_size; 472 new_bh->b_bdev = journal->j_dev; 473 new_bh->b_blocknr = blocknr; 474 new_bh->b_private = bh_in; 475 set_buffer_mapped(new_bh); 476 set_buffer_dirty(new_bh); 477 478 *bh_out = new_bh; 479 480 /* 481 * The to-be-written buffer needs to get moved to the io queue, 482 * and the original buffer whose contents we are shadowing or 483 * copying is moved to the transaction's shadow queue. 484 */ 485 JBUFFER_TRACE(jh_in, "file as BJ_Shadow"); 486 spin_lock(&journal->j_list_lock); 487 __jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow); 488 spin_unlock(&journal->j_list_lock); 489 set_buffer_shadow(bh_in); 490 jbd_unlock_bh_state(bh_in); 491 492 return do_escape | (done_copy_out << 1); 493 } 494 495 /* 496 * Allocation code for the journal file. Manage the space left in the 497 * journal, so that we can begin checkpointing when appropriate. 498 */ 499 500 /* 501 * Called with j_state_lock locked for writing. 502 * Returns true if a transaction commit was started. 503 */ 504 int __jbd2_log_start_commit(journal_t *journal, tid_t target) 505 { 506 /* Return if the txn has already requested to be committed */ 507 if (journal->j_commit_request == target) 508 return 0; 509 510 /* 511 * The only transaction we can possibly wait upon is the 512 * currently running transaction (if it exists). Otherwise, 513 * the target tid must be an old one. 514 */ 515 if (journal->j_running_transaction && 516 journal->j_running_transaction->t_tid == target) { 517 /* 518 * We want a new commit: OK, mark the request and wakeup the 519 * commit thread. We do _not_ do the commit ourselves. 520 */ 521 522 journal->j_commit_request = target; 523 jbd_debug(1, "JBD2: requesting commit %d/%d\n", 524 journal->j_commit_request, 525 journal->j_commit_sequence); 526 journal->j_running_transaction->t_requested = jiffies; 527 wake_up(&journal->j_wait_commit); 528 return 1; 529 } else if (!tid_geq(journal->j_commit_request, target)) 530 /* This should never happen, but if it does, preserve 531 the evidence before kjournald goes into a loop and 532 increments j_commit_sequence beyond all recognition. */ 533 WARN_ONCE(1, "JBD2: bad log_start_commit: %u %u %u %u\n", 534 journal->j_commit_request, 535 journal->j_commit_sequence, 536 target, journal->j_running_transaction ? 537 journal->j_running_transaction->t_tid : 0); 538 return 0; 539 } 540 541 int jbd2_log_start_commit(journal_t *journal, tid_t tid) 542 { 543 int ret; 544 545 write_lock(&journal->j_state_lock); 546 ret = __jbd2_log_start_commit(journal, tid); 547 write_unlock(&journal->j_state_lock); 548 return ret; 549 } 550 551 /* 552 * Force and wait any uncommitted transactions. We can only force the running 553 * transaction if we don't have an active handle, otherwise, we will deadlock. 554 * Returns: <0 in case of error, 555 * 0 if nothing to commit, 556 * 1 if transaction was successfully committed. 557 */ 558 static int __jbd2_journal_force_commit(journal_t *journal) 559 { 560 transaction_t *transaction = NULL; 561 tid_t tid; 562 int need_to_start = 0, ret = 0; 563 564 read_lock(&journal->j_state_lock); 565 if (journal->j_running_transaction && !current->journal_info) { 566 transaction = journal->j_running_transaction; 567 if (!tid_geq(journal->j_commit_request, transaction->t_tid)) 568 need_to_start = 1; 569 } else if (journal->j_committing_transaction) 570 transaction = journal->j_committing_transaction; 571 572 if (!transaction) { 573 /* Nothing to commit */ 574 read_unlock(&journal->j_state_lock); 575 return 0; 576 } 577 tid = transaction->t_tid; 578 read_unlock(&journal->j_state_lock); 579 if (need_to_start) 580 jbd2_log_start_commit(journal, tid); 581 ret = jbd2_log_wait_commit(journal, tid); 582 if (!ret) 583 ret = 1; 584 585 return ret; 586 } 587 588 /** 589 * Force and wait upon a commit if the calling process is not within 590 * transaction. This is used for forcing out undo-protected data which contains 591 * bitmaps, when the fs is running out of space. 592 * 593 * @journal: journal to force 594 * Returns true if progress was made. 595 */ 596 int jbd2_journal_force_commit_nested(journal_t *journal) 597 { 598 int ret; 599 600 ret = __jbd2_journal_force_commit(journal); 601 return ret > 0; 602 } 603 604 /** 605 * int journal_force_commit() - force any uncommitted transactions 606 * @journal: journal to force 607 * 608 * Caller want unconditional commit. We can only force the running transaction 609 * if we don't have an active handle, otherwise, we will deadlock. 610 */ 611 int jbd2_journal_force_commit(journal_t *journal) 612 { 613 int ret; 614 615 J_ASSERT(!current->journal_info); 616 ret = __jbd2_journal_force_commit(journal); 617 if (ret > 0) 618 ret = 0; 619 return ret; 620 } 621 622 /* 623 * Start a commit of the current running transaction (if any). Returns true 624 * if a transaction is going to be committed (or is currently already 625 * committing), and fills its tid in at *ptid 626 */ 627 int jbd2_journal_start_commit(journal_t *journal, tid_t *ptid) 628 { 629 int ret = 0; 630 631 write_lock(&journal->j_state_lock); 632 if (journal->j_running_transaction) { 633 tid_t tid = journal->j_running_transaction->t_tid; 634 635 __jbd2_log_start_commit(journal, tid); 636 /* There's a running transaction and we've just made sure 637 * it's commit has been scheduled. */ 638 if (ptid) 639 *ptid = tid; 640 ret = 1; 641 } else if (journal->j_committing_transaction) { 642 /* 643 * If commit has been started, then we have to wait for 644 * completion of that transaction. 645 */ 646 if (ptid) 647 *ptid = journal->j_committing_transaction->t_tid; 648 ret = 1; 649 } 650 write_unlock(&journal->j_state_lock); 651 return ret; 652 } 653 654 /* 655 * Return 1 if a given transaction has not yet sent barrier request 656 * connected with a transaction commit. If 0 is returned, transaction 657 * may or may not have sent the barrier. Used to avoid sending barrier 658 * twice in common cases. 659 */ 660 int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid) 661 { 662 int ret = 0; 663 transaction_t *commit_trans; 664 665 if (!(journal->j_flags & JBD2_BARRIER)) 666 return 0; 667 read_lock(&journal->j_state_lock); 668 /* Transaction already committed? */ 669 if (tid_geq(journal->j_commit_sequence, tid)) 670 goto out; 671 commit_trans = journal->j_committing_transaction; 672 if (!commit_trans || commit_trans->t_tid != tid) { 673 ret = 1; 674 goto out; 675 } 676 /* 677 * Transaction is being committed and we already proceeded to 678 * submitting a flush to fs partition? 679 */ 680 if (journal->j_fs_dev != journal->j_dev) { 681 if (!commit_trans->t_need_data_flush || 682 commit_trans->t_state >= T_COMMIT_DFLUSH) 683 goto out; 684 } else { 685 if (commit_trans->t_state >= T_COMMIT_JFLUSH) 686 goto out; 687 } 688 ret = 1; 689 out: 690 read_unlock(&journal->j_state_lock); 691 return ret; 692 } 693 EXPORT_SYMBOL(jbd2_trans_will_send_data_barrier); 694 695 /* 696 * Wait for a specified commit to complete. 697 * The caller may not hold the journal lock. 698 */ 699 int jbd2_log_wait_commit(journal_t *journal, tid_t tid) 700 { 701 int err = 0; 702 703 read_lock(&journal->j_state_lock); 704 #ifdef CONFIG_PROVE_LOCKING 705 /* 706 * Some callers make sure transaction is already committing and in that 707 * case we cannot block on open handles anymore. So don't warn in that 708 * case. 709 */ 710 if (tid_gt(tid, journal->j_commit_sequence) && 711 (!journal->j_committing_transaction || 712 journal->j_committing_transaction->t_tid != tid)) { 713 read_unlock(&journal->j_state_lock); 714 jbd2_might_wait_for_commit(journal); 715 read_lock(&journal->j_state_lock); 716 } 717 #endif 718 #ifdef CONFIG_JBD2_DEBUG 719 if (!tid_geq(journal->j_commit_request, tid)) { 720 printk(KERN_ERR 721 "%s: error: j_commit_request=%d, tid=%d\n", 722 __func__, journal->j_commit_request, tid); 723 } 724 #endif 725 while (tid_gt(tid, journal->j_commit_sequence)) { 726 jbd_debug(1, "JBD2: want %d, j_commit_sequence=%d\n", 727 tid, journal->j_commit_sequence); 728 read_unlock(&journal->j_state_lock); 729 wake_up(&journal->j_wait_commit); 730 wait_event(journal->j_wait_done_commit, 731 !tid_gt(tid, journal->j_commit_sequence)); 732 read_lock(&journal->j_state_lock); 733 } 734 read_unlock(&journal->j_state_lock); 735 736 if (unlikely(is_journal_aborted(journal))) 737 err = -EIO; 738 return err; 739 } 740 741 /* 742 * When this function returns the transaction corresponding to tid 743 * will be completed. If the transaction has currently running, start 744 * committing that transaction before waiting for it to complete. If 745 * the transaction id is stale, it is by definition already completed, 746 * so just return SUCCESS. 747 */ 748 int jbd2_complete_transaction(journal_t *journal, tid_t tid) 749 { 750 int need_to_wait = 1; 751 752 read_lock(&journal->j_state_lock); 753 if (journal->j_running_transaction && 754 journal->j_running_transaction->t_tid == tid) { 755 if (journal->j_commit_request != tid) { 756 /* transaction not yet started, so request it */ 757 read_unlock(&journal->j_state_lock); 758 jbd2_log_start_commit(journal, tid); 759 goto wait_commit; 760 } 761 } else if (!(journal->j_committing_transaction && 762 journal->j_committing_transaction->t_tid == tid)) 763 need_to_wait = 0; 764 read_unlock(&journal->j_state_lock); 765 if (!need_to_wait) 766 return 0; 767 wait_commit: 768 return jbd2_log_wait_commit(journal, tid); 769 } 770 EXPORT_SYMBOL(jbd2_complete_transaction); 771 772 /* 773 * Log buffer allocation routines: 774 */ 775 776 int jbd2_journal_next_log_block(journal_t *journal, unsigned long long *retp) 777 { 778 unsigned long blocknr; 779 780 write_lock(&journal->j_state_lock); 781 J_ASSERT(journal->j_free > 1); 782 783 blocknr = journal->j_head; 784 journal->j_head++; 785 journal->j_free--; 786 if (journal->j_head == journal->j_last) 787 journal->j_head = journal->j_first; 788 write_unlock(&journal->j_state_lock); 789 return jbd2_journal_bmap(journal, blocknr, retp); 790 } 791 792 /* 793 * Conversion of logical to physical block numbers for the journal 794 * 795 * On external journals the journal blocks are identity-mapped, so 796 * this is a no-op. If needed, we can use j_blk_offset - everything is 797 * ready. 798 */ 799 int jbd2_journal_bmap(journal_t *journal, unsigned long blocknr, 800 unsigned long long *retp) 801 { 802 int err = 0; 803 unsigned long long ret; 804 805 if (journal->j_inode) { 806 ret = bmap(journal->j_inode, blocknr); 807 if (ret) 808 *retp = ret; 809 else { 810 printk(KERN_ALERT "%s: journal block not found " 811 "at offset %lu on %s\n", 812 __func__, blocknr, journal->j_devname); 813 err = -EIO; 814 __journal_abort_soft(journal, err); 815 } 816 } else { 817 *retp = blocknr; /* +journal->j_blk_offset */ 818 } 819 return err; 820 } 821 822 /* 823 * We play buffer_head aliasing tricks to write data/metadata blocks to 824 * the journal without copying their contents, but for journal 825 * descriptor blocks we do need to generate bona fide buffers. 826 * 827 * After the caller of jbd2_journal_get_descriptor_buffer() has finished modifying 828 * the buffer's contents they really should run flush_dcache_page(bh->b_page). 829 * But we don't bother doing that, so there will be coherency problems with 830 * mmaps of blockdevs which hold live JBD-controlled filesystems. 831 */ 832 struct buffer_head * 833 jbd2_journal_get_descriptor_buffer(transaction_t *transaction, int type) 834 { 835 journal_t *journal = transaction->t_journal; 836 struct buffer_head *bh; 837 unsigned long long blocknr; 838 journal_header_t *header; 839 int err; 840 841 err = jbd2_journal_next_log_block(journal, &blocknr); 842 843 if (err) 844 return NULL; 845 846 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); 847 if (!bh) 848 return NULL; 849 lock_buffer(bh); 850 memset(bh->b_data, 0, journal->j_blocksize); 851 header = (journal_header_t *)bh->b_data; 852 header->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER); 853 header->h_blocktype = cpu_to_be32(type); 854 header->h_sequence = cpu_to_be32(transaction->t_tid); 855 set_buffer_uptodate(bh); 856 unlock_buffer(bh); 857 BUFFER_TRACE(bh, "return this buffer"); 858 return bh; 859 } 860 861 void jbd2_descriptor_block_csum_set(journal_t *j, struct buffer_head *bh) 862 { 863 struct jbd2_journal_block_tail *tail; 864 __u32 csum; 865 866 if (!jbd2_journal_has_csum_v2or3(j)) 867 return; 868 869 tail = (struct jbd2_journal_block_tail *)(bh->b_data + j->j_blocksize - 870 sizeof(struct jbd2_journal_block_tail)); 871 tail->t_checksum = 0; 872 csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize); 873 tail->t_checksum = cpu_to_be32(csum); 874 } 875 876 /* 877 * Return tid of the oldest transaction in the journal and block in the journal 878 * where the transaction starts. 879 * 880 * If the journal is now empty, return which will be the next transaction ID 881 * we will write and where will that transaction start. 882 * 883 * The return value is 0 if journal tail cannot be pushed any further, 1 if 884 * it can. 885 */ 886 int jbd2_journal_get_log_tail(journal_t *journal, tid_t *tid, 887 unsigned long *block) 888 { 889 transaction_t *transaction; 890 int ret; 891 892 read_lock(&journal->j_state_lock); 893 spin_lock(&journal->j_list_lock); 894 transaction = journal->j_checkpoint_transactions; 895 if (transaction) { 896 *tid = transaction->t_tid; 897 *block = transaction->t_log_start; 898 } else if ((transaction = journal->j_committing_transaction) != NULL) { 899 *tid = transaction->t_tid; 900 *block = transaction->t_log_start; 901 } else if ((transaction = journal->j_running_transaction) != NULL) { 902 *tid = transaction->t_tid; 903 *block = journal->j_head; 904 } else { 905 *tid = journal->j_transaction_sequence; 906 *block = journal->j_head; 907 } 908 ret = tid_gt(*tid, journal->j_tail_sequence); 909 spin_unlock(&journal->j_list_lock); 910 read_unlock(&journal->j_state_lock); 911 912 return ret; 913 } 914 915 /* 916 * Update information in journal structure and in on disk journal superblock 917 * about log tail. This function does not check whether information passed in 918 * really pushes log tail further. It's responsibility of the caller to make 919 * sure provided log tail information is valid (e.g. by holding 920 * j_checkpoint_mutex all the time between computing log tail and calling this 921 * function as is the case with jbd2_cleanup_journal_tail()). 922 * 923 * Requires j_checkpoint_mutex 924 */ 925 int __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block) 926 { 927 unsigned long freed; 928 int ret; 929 930 BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex)); 931 932 /* 933 * We cannot afford for write to remain in drive's caches since as 934 * soon as we update j_tail, next transaction can start reusing journal 935 * space and if we lose sb update during power failure we'd replay 936 * old transaction with possibly newly overwritten data. 937 */ 938 ret = jbd2_journal_update_sb_log_tail(journal, tid, block, 939 REQ_SYNC | REQ_FUA); 940 if (ret) 941 goto out; 942 943 write_lock(&journal->j_state_lock); 944 freed = block - journal->j_tail; 945 if (block < journal->j_tail) 946 freed += journal->j_last - journal->j_first; 947 948 trace_jbd2_update_log_tail(journal, tid, block, freed); 949 jbd_debug(1, 950 "Cleaning journal tail from %d to %d (offset %lu), " 951 "freeing %lu\n", 952 journal->j_tail_sequence, tid, block, freed); 953 954 journal->j_free += freed; 955 journal->j_tail_sequence = tid; 956 journal->j_tail = block; 957 write_unlock(&journal->j_state_lock); 958 959 out: 960 return ret; 961 } 962 963 /* 964 * This is a variaon of __jbd2_update_log_tail which checks for validity of 965 * provided log tail and locks j_checkpoint_mutex. So it is safe against races 966 * with other threads updating log tail. 967 */ 968 void jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block) 969 { 970 mutex_lock_io(&journal->j_checkpoint_mutex); 971 if (tid_gt(tid, journal->j_tail_sequence)) 972 __jbd2_update_log_tail(journal, tid, block); 973 mutex_unlock(&journal->j_checkpoint_mutex); 974 } 975 976 struct jbd2_stats_proc_session { 977 journal_t *journal; 978 struct transaction_stats_s *stats; 979 int start; 980 int max; 981 }; 982 983 static void *jbd2_seq_info_start(struct seq_file *seq, loff_t *pos) 984 { 985 return *pos ? NULL : SEQ_START_TOKEN; 986 } 987 988 static void *jbd2_seq_info_next(struct seq_file *seq, void *v, loff_t *pos) 989 { 990 return NULL; 991 } 992 993 static int jbd2_seq_info_show(struct seq_file *seq, void *v) 994 { 995 struct jbd2_stats_proc_session *s = seq->private; 996 997 if (v != SEQ_START_TOKEN) 998 return 0; 999 seq_printf(seq, "%lu transactions (%lu requested), " 1000 "each up to %u blocks\n", 1001 s->stats->ts_tid, s->stats->ts_requested, 1002 s->journal->j_max_transaction_buffers); 1003 if (s->stats->ts_tid == 0) 1004 return 0; 1005 seq_printf(seq, "average: \n %ums waiting for transaction\n", 1006 jiffies_to_msecs(s->stats->run.rs_wait / s->stats->ts_tid)); 1007 seq_printf(seq, " %ums request delay\n", 1008 (s->stats->ts_requested == 0) ? 0 : 1009 jiffies_to_msecs(s->stats->run.rs_request_delay / 1010 s->stats->ts_requested)); 1011 seq_printf(seq, " %ums running transaction\n", 1012 jiffies_to_msecs(s->stats->run.rs_running / s->stats->ts_tid)); 1013 seq_printf(seq, " %ums transaction was being locked\n", 1014 jiffies_to_msecs(s->stats->run.rs_locked / s->stats->ts_tid)); 1015 seq_printf(seq, " %ums flushing data (in ordered mode)\n", 1016 jiffies_to_msecs(s->stats->run.rs_flushing / s->stats->ts_tid)); 1017 seq_printf(seq, " %ums logging transaction\n", 1018 jiffies_to_msecs(s->stats->run.rs_logging / s->stats->ts_tid)); 1019 seq_printf(seq, " %lluus average transaction commit time\n", 1020 div_u64(s->journal->j_average_commit_time, 1000)); 1021 seq_printf(seq, " %lu handles per transaction\n", 1022 s->stats->run.rs_handle_count / s->stats->ts_tid); 1023 seq_printf(seq, " %lu blocks per transaction\n", 1024 s->stats->run.rs_blocks / s->stats->ts_tid); 1025 seq_printf(seq, " %lu logged blocks per transaction\n", 1026 s->stats->run.rs_blocks_logged / s->stats->ts_tid); 1027 return 0; 1028 } 1029 1030 static void jbd2_seq_info_stop(struct seq_file *seq, void *v) 1031 { 1032 } 1033 1034 static const struct seq_operations jbd2_seq_info_ops = { 1035 .start = jbd2_seq_info_start, 1036 .next = jbd2_seq_info_next, 1037 .stop = jbd2_seq_info_stop, 1038 .show = jbd2_seq_info_show, 1039 }; 1040 1041 static int jbd2_seq_info_open(struct inode *inode, struct file *file) 1042 { 1043 journal_t *journal = PDE_DATA(inode); 1044 struct jbd2_stats_proc_session *s; 1045 int rc, size; 1046 1047 s = kmalloc(sizeof(*s), GFP_KERNEL); 1048 if (s == NULL) 1049 return -ENOMEM; 1050 size = sizeof(struct transaction_stats_s); 1051 s->stats = kmalloc(size, GFP_KERNEL); 1052 if (s->stats == NULL) { 1053 kfree(s); 1054 return -ENOMEM; 1055 } 1056 spin_lock(&journal->j_history_lock); 1057 memcpy(s->stats, &journal->j_stats, size); 1058 s->journal = journal; 1059 spin_unlock(&journal->j_history_lock); 1060 1061 rc = seq_open(file, &jbd2_seq_info_ops); 1062 if (rc == 0) { 1063 struct seq_file *m = file->private_data; 1064 m->private = s; 1065 } else { 1066 kfree(s->stats); 1067 kfree(s); 1068 } 1069 return rc; 1070 1071 } 1072 1073 static int jbd2_seq_info_release(struct inode *inode, struct file *file) 1074 { 1075 struct seq_file *seq = file->private_data; 1076 struct jbd2_stats_proc_session *s = seq->private; 1077 kfree(s->stats); 1078 kfree(s); 1079 return seq_release(inode, file); 1080 } 1081 1082 static const struct file_operations jbd2_seq_info_fops = { 1083 .owner = THIS_MODULE, 1084 .open = jbd2_seq_info_open, 1085 .read = seq_read, 1086 .llseek = seq_lseek, 1087 .release = jbd2_seq_info_release, 1088 }; 1089 1090 static struct proc_dir_entry *proc_jbd2_stats; 1091 1092 static void jbd2_stats_proc_init(journal_t *journal) 1093 { 1094 journal->j_proc_entry = proc_mkdir(journal->j_devname, proc_jbd2_stats); 1095 if (journal->j_proc_entry) { 1096 proc_create_data("info", S_IRUGO, journal->j_proc_entry, 1097 &jbd2_seq_info_fops, journal); 1098 } 1099 } 1100 1101 static void jbd2_stats_proc_exit(journal_t *journal) 1102 { 1103 remove_proc_entry("info", journal->j_proc_entry); 1104 remove_proc_entry(journal->j_devname, proc_jbd2_stats); 1105 } 1106 1107 /* 1108 * Management for journal control blocks: functions to create and 1109 * destroy journal_t structures, and to initialise and read existing 1110 * journal blocks from disk. */ 1111 1112 /* First: create and setup a journal_t object in memory. We initialise 1113 * very few fields yet: that has to wait until we have created the 1114 * journal structures from from scratch, or loaded them from disk. */ 1115 1116 static journal_t *journal_init_common(struct block_device *bdev, 1117 struct block_device *fs_dev, 1118 unsigned long long start, int len, int blocksize) 1119 { 1120 static struct lock_class_key jbd2_trans_commit_key; 1121 journal_t *journal; 1122 int err; 1123 struct buffer_head *bh; 1124 int n; 1125 1126 journal = kzalloc(sizeof(*journal), GFP_KERNEL); 1127 if (!journal) 1128 return NULL; 1129 1130 init_waitqueue_head(&journal->j_wait_transaction_locked); 1131 init_waitqueue_head(&journal->j_wait_done_commit); 1132 init_waitqueue_head(&journal->j_wait_commit); 1133 init_waitqueue_head(&journal->j_wait_updates); 1134 init_waitqueue_head(&journal->j_wait_reserved); 1135 mutex_init(&journal->j_barrier); 1136 mutex_init(&journal->j_checkpoint_mutex); 1137 spin_lock_init(&journal->j_revoke_lock); 1138 spin_lock_init(&journal->j_list_lock); 1139 rwlock_init(&journal->j_state_lock); 1140 1141 journal->j_commit_interval = (HZ * JBD2_DEFAULT_MAX_COMMIT_AGE); 1142 journal->j_min_batch_time = 0; 1143 journal->j_max_batch_time = 15000; /* 15ms */ 1144 atomic_set(&journal->j_reserved_credits, 0); 1145 1146 /* The journal is marked for error until we succeed with recovery! */ 1147 journal->j_flags = JBD2_ABORT; 1148 1149 /* Set up a default-sized revoke table for the new mount. */ 1150 err = jbd2_journal_init_revoke(journal, JOURNAL_REVOKE_DEFAULT_HASH); 1151 if (err) 1152 goto err_cleanup; 1153 1154 spin_lock_init(&journal->j_history_lock); 1155 1156 lockdep_init_map(&journal->j_trans_commit_map, "jbd2_handle", 1157 &jbd2_trans_commit_key, 0); 1158 1159 /* journal descriptor can store up to n blocks -bzzz */ 1160 journal->j_blocksize = blocksize; 1161 journal->j_dev = bdev; 1162 journal->j_fs_dev = fs_dev; 1163 journal->j_blk_offset = start; 1164 journal->j_maxlen = len; 1165 n = journal->j_blocksize / sizeof(journal_block_tag_t); 1166 journal->j_wbufsize = n; 1167 journal->j_wbuf = kmalloc_array(n, sizeof(struct buffer_head *), 1168 GFP_KERNEL); 1169 if (!journal->j_wbuf) 1170 goto err_cleanup; 1171 1172 bh = getblk_unmovable(journal->j_dev, start, journal->j_blocksize); 1173 if (!bh) { 1174 pr_err("%s: Cannot get buffer for journal superblock\n", 1175 __func__); 1176 goto err_cleanup; 1177 } 1178 journal->j_sb_buffer = bh; 1179 journal->j_superblock = (journal_superblock_t *)bh->b_data; 1180 1181 return journal; 1182 1183 err_cleanup: 1184 kfree(journal->j_wbuf); 1185 jbd2_journal_destroy_revoke(journal); 1186 kfree(journal); 1187 return NULL; 1188 } 1189 1190 /* jbd2_journal_init_dev and jbd2_journal_init_inode: 1191 * 1192 * Create a journal structure assigned some fixed set of disk blocks to 1193 * the journal. We don't actually touch those disk blocks yet, but we 1194 * need to set up all of the mapping information to tell the journaling 1195 * system where the journal blocks are. 1196 * 1197 */ 1198 1199 /** 1200 * journal_t * jbd2_journal_init_dev() - creates and initialises a journal structure 1201 * @bdev: Block device on which to create the journal 1202 * @fs_dev: Device which hold journalled filesystem for this journal. 1203 * @start: Block nr Start of journal. 1204 * @len: Length of the journal in blocks. 1205 * @blocksize: blocksize of journalling device 1206 * 1207 * Returns: a newly created journal_t * 1208 * 1209 * jbd2_journal_init_dev creates a journal which maps a fixed contiguous 1210 * range of blocks on an arbitrary block device. 1211 * 1212 */ 1213 journal_t *jbd2_journal_init_dev(struct block_device *bdev, 1214 struct block_device *fs_dev, 1215 unsigned long long start, int len, int blocksize) 1216 { 1217 journal_t *journal; 1218 1219 journal = journal_init_common(bdev, fs_dev, start, len, blocksize); 1220 if (!journal) 1221 return NULL; 1222 1223 bdevname(journal->j_dev, journal->j_devname); 1224 strreplace(journal->j_devname, '/', '!'); 1225 jbd2_stats_proc_init(journal); 1226 1227 return journal; 1228 } 1229 1230 /** 1231 * journal_t * jbd2_journal_init_inode () - creates a journal which maps to a inode. 1232 * @inode: An inode to create the journal in 1233 * 1234 * jbd2_journal_init_inode creates a journal which maps an on-disk inode as 1235 * the journal. The inode must exist already, must support bmap() and 1236 * must have all data blocks preallocated. 1237 */ 1238 journal_t *jbd2_journal_init_inode(struct inode *inode) 1239 { 1240 journal_t *journal; 1241 char *p; 1242 unsigned long long blocknr; 1243 1244 blocknr = bmap(inode, 0); 1245 if (!blocknr) { 1246 pr_err("%s: Cannot locate journal superblock\n", 1247 __func__); 1248 return NULL; 1249 } 1250 1251 jbd_debug(1, "JBD2: inode %s/%ld, size %lld, bits %d, blksize %ld\n", 1252 inode->i_sb->s_id, inode->i_ino, (long long) inode->i_size, 1253 inode->i_sb->s_blocksize_bits, inode->i_sb->s_blocksize); 1254 1255 journal = journal_init_common(inode->i_sb->s_bdev, inode->i_sb->s_bdev, 1256 blocknr, inode->i_size >> inode->i_sb->s_blocksize_bits, 1257 inode->i_sb->s_blocksize); 1258 if (!journal) 1259 return NULL; 1260 1261 journal->j_inode = inode; 1262 bdevname(journal->j_dev, journal->j_devname); 1263 p = strreplace(journal->j_devname, '/', '!'); 1264 sprintf(p, "-%lu", journal->j_inode->i_ino); 1265 jbd2_stats_proc_init(journal); 1266 1267 return journal; 1268 } 1269 1270 /* 1271 * If the journal init or create aborts, we need to mark the journal 1272 * superblock as being NULL to prevent the journal destroy from writing 1273 * back a bogus superblock. 1274 */ 1275 static void journal_fail_superblock (journal_t *journal) 1276 { 1277 struct buffer_head *bh = journal->j_sb_buffer; 1278 brelse(bh); 1279 journal->j_sb_buffer = NULL; 1280 } 1281 1282 /* 1283 * Given a journal_t structure, initialise the various fields for 1284 * startup of a new journaling session. We use this both when creating 1285 * a journal, and after recovering an old journal to reset it for 1286 * subsequent use. 1287 */ 1288 1289 static int journal_reset(journal_t *journal) 1290 { 1291 journal_superblock_t *sb = journal->j_superblock; 1292 unsigned long long first, last; 1293 1294 first = be32_to_cpu(sb->s_first); 1295 last = be32_to_cpu(sb->s_maxlen); 1296 if (first + JBD2_MIN_JOURNAL_BLOCKS > last + 1) { 1297 printk(KERN_ERR "JBD2: Journal too short (blocks %llu-%llu).\n", 1298 first, last); 1299 journal_fail_superblock(journal); 1300 return -EINVAL; 1301 } 1302 1303 journal->j_first = first; 1304 journal->j_last = last; 1305 1306 journal->j_head = first; 1307 journal->j_tail = first; 1308 journal->j_free = last - first; 1309 1310 journal->j_tail_sequence = journal->j_transaction_sequence; 1311 journal->j_commit_sequence = journal->j_transaction_sequence - 1; 1312 journal->j_commit_request = journal->j_commit_sequence; 1313 1314 journal->j_max_transaction_buffers = journal->j_maxlen / 4; 1315 1316 /* 1317 * As a special case, if the on-disk copy is already marked as needing 1318 * no recovery (s_start == 0), then we can safely defer the superblock 1319 * update until the next commit by setting JBD2_FLUSHED. This avoids 1320 * attempting a write to a potential-readonly device. 1321 */ 1322 if (sb->s_start == 0) { 1323 jbd_debug(1, "JBD2: Skipping superblock update on recovered sb " 1324 "(start %ld, seq %d, errno %d)\n", 1325 journal->j_tail, journal->j_tail_sequence, 1326 journal->j_errno); 1327 journal->j_flags |= JBD2_FLUSHED; 1328 } else { 1329 /* Lock here to make assertions happy... */ 1330 mutex_lock_io(&journal->j_checkpoint_mutex); 1331 /* 1332 * Update log tail information. We use REQ_FUA since new 1333 * transaction will start reusing journal space and so we 1334 * must make sure information about current log tail is on 1335 * disk before that. 1336 */ 1337 jbd2_journal_update_sb_log_tail(journal, 1338 journal->j_tail_sequence, 1339 journal->j_tail, 1340 REQ_SYNC | REQ_FUA); 1341 mutex_unlock(&journal->j_checkpoint_mutex); 1342 } 1343 return jbd2_journal_start_thread(journal); 1344 } 1345 1346 static int jbd2_write_superblock(journal_t *journal, int write_flags) 1347 { 1348 struct buffer_head *bh = journal->j_sb_buffer; 1349 journal_superblock_t *sb = journal->j_superblock; 1350 int ret; 1351 1352 trace_jbd2_write_superblock(journal, write_flags); 1353 if (!(journal->j_flags & JBD2_BARRIER)) 1354 write_flags &= ~(REQ_FUA | REQ_PREFLUSH); 1355 lock_buffer(bh); 1356 if (buffer_write_io_error(bh)) { 1357 /* 1358 * Oh, dear. A previous attempt to write the journal 1359 * superblock failed. This could happen because the 1360 * USB device was yanked out. Or it could happen to 1361 * be a transient write error and maybe the block will 1362 * be remapped. Nothing we can do but to retry the 1363 * write and hope for the best. 1364 */ 1365 printk(KERN_ERR "JBD2: previous I/O error detected " 1366 "for journal superblock update for %s.\n", 1367 journal->j_devname); 1368 clear_buffer_write_io_error(bh); 1369 set_buffer_uptodate(bh); 1370 } 1371 jbd2_superblock_csum_set(journal, sb); 1372 get_bh(bh); 1373 bh->b_end_io = end_buffer_write_sync; 1374 ret = submit_bh(REQ_OP_WRITE, write_flags, bh); 1375 wait_on_buffer(bh); 1376 if (buffer_write_io_error(bh)) { 1377 clear_buffer_write_io_error(bh); 1378 set_buffer_uptodate(bh); 1379 ret = -EIO; 1380 } 1381 if (ret) { 1382 printk(KERN_ERR "JBD2: Error %d detected when updating " 1383 "journal superblock for %s.\n", ret, 1384 journal->j_devname); 1385 jbd2_journal_abort(journal, ret); 1386 } 1387 1388 return ret; 1389 } 1390 1391 /** 1392 * jbd2_journal_update_sb_log_tail() - Update log tail in journal sb on disk. 1393 * @journal: The journal to update. 1394 * @tail_tid: TID of the new transaction at the tail of the log 1395 * @tail_block: The first block of the transaction at the tail of the log 1396 * @write_op: With which operation should we write the journal sb 1397 * 1398 * Update a journal's superblock information about log tail and write it to 1399 * disk, waiting for the IO to complete. 1400 */ 1401 int jbd2_journal_update_sb_log_tail(journal_t *journal, tid_t tail_tid, 1402 unsigned long tail_block, int write_op) 1403 { 1404 journal_superblock_t *sb = journal->j_superblock; 1405 int ret; 1406 1407 BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex)); 1408 jbd_debug(1, "JBD2: updating superblock (start %lu, seq %u)\n", 1409 tail_block, tail_tid); 1410 1411 sb->s_sequence = cpu_to_be32(tail_tid); 1412 sb->s_start = cpu_to_be32(tail_block); 1413 1414 ret = jbd2_write_superblock(journal, write_op); 1415 if (ret) 1416 goto out; 1417 1418 /* Log is no longer empty */ 1419 write_lock(&journal->j_state_lock); 1420 WARN_ON(!sb->s_sequence); 1421 journal->j_flags &= ~JBD2_FLUSHED; 1422 write_unlock(&journal->j_state_lock); 1423 1424 out: 1425 return ret; 1426 } 1427 1428 /** 1429 * jbd2_mark_journal_empty() - Mark on disk journal as empty. 1430 * @journal: The journal to update. 1431 * @write_op: With which operation should we write the journal sb 1432 * 1433 * Update a journal's dynamic superblock fields to show that journal is empty. 1434 * Write updated superblock to disk waiting for IO to complete. 1435 */ 1436 static void jbd2_mark_journal_empty(journal_t *journal, int write_op) 1437 { 1438 journal_superblock_t *sb = journal->j_superblock; 1439 1440 BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex)); 1441 read_lock(&journal->j_state_lock); 1442 /* Is it already empty? */ 1443 if (sb->s_start == 0) { 1444 read_unlock(&journal->j_state_lock); 1445 return; 1446 } 1447 jbd_debug(1, "JBD2: Marking journal as empty (seq %d)\n", 1448 journal->j_tail_sequence); 1449 1450 sb->s_sequence = cpu_to_be32(journal->j_tail_sequence); 1451 sb->s_start = cpu_to_be32(0); 1452 read_unlock(&journal->j_state_lock); 1453 1454 jbd2_write_superblock(journal, write_op); 1455 1456 /* Log is no longer empty */ 1457 write_lock(&journal->j_state_lock); 1458 journal->j_flags |= JBD2_FLUSHED; 1459 write_unlock(&journal->j_state_lock); 1460 } 1461 1462 1463 /** 1464 * jbd2_journal_update_sb_errno() - Update error in the journal. 1465 * @journal: The journal to update. 1466 * 1467 * Update a journal's errno. Write updated superblock to disk waiting for IO 1468 * to complete. 1469 */ 1470 void jbd2_journal_update_sb_errno(journal_t *journal) 1471 { 1472 journal_superblock_t *sb = journal->j_superblock; 1473 1474 read_lock(&journal->j_state_lock); 1475 jbd_debug(1, "JBD2: updating superblock error (errno %d)\n", 1476 journal->j_errno); 1477 sb->s_errno = cpu_to_be32(journal->j_errno); 1478 read_unlock(&journal->j_state_lock); 1479 1480 jbd2_write_superblock(journal, REQ_SYNC | REQ_FUA); 1481 } 1482 EXPORT_SYMBOL(jbd2_journal_update_sb_errno); 1483 1484 /* 1485 * Read the superblock for a given journal, performing initial 1486 * validation of the format. 1487 */ 1488 static int journal_get_superblock(journal_t *journal) 1489 { 1490 struct buffer_head *bh; 1491 journal_superblock_t *sb; 1492 int err = -EIO; 1493 1494 bh = journal->j_sb_buffer; 1495 1496 J_ASSERT(bh != NULL); 1497 if (!buffer_uptodate(bh)) { 1498 ll_rw_block(REQ_OP_READ, 0, 1, &bh); 1499 wait_on_buffer(bh); 1500 if (!buffer_uptodate(bh)) { 1501 printk(KERN_ERR 1502 "JBD2: IO error reading journal superblock\n"); 1503 goto out; 1504 } 1505 } 1506 1507 if (buffer_verified(bh)) 1508 return 0; 1509 1510 sb = journal->j_superblock; 1511 1512 err = -EINVAL; 1513 1514 if (sb->s_header.h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER) || 1515 sb->s_blocksize != cpu_to_be32(journal->j_blocksize)) { 1516 printk(KERN_WARNING "JBD2: no valid journal superblock found\n"); 1517 goto out; 1518 } 1519 1520 switch(be32_to_cpu(sb->s_header.h_blocktype)) { 1521 case JBD2_SUPERBLOCK_V1: 1522 journal->j_format_version = 1; 1523 break; 1524 case JBD2_SUPERBLOCK_V2: 1525 journal->j_format_version = 2; 1526 break; 1527 default: 1528 printk(KERN_WARNING "JBD2: unrecognised superblock format ID\n"); 1529 goto out; 1530 } 1531 1532 if (be32_to_cpu(sb->s_maxlen) < journal->j_maxlen) 1533 journal->j_maxlen = be32_to_cpu(sb->s_maxlen); 1534 else if (be32_to_cpu(sb->s_maxlen) > journal->j_maxlen) { 1535 printk(KERN_WARNING "JBD2: journal file too short\n"); 1536 goto out; 1537 } 1538 1539 if (be32_to_cpu(sb->s_first) == 0 || 1540 be32_to_cpu(sb->s_first) >= journal->j_maxlen) { 1541 printk(KERN_WARNING 1542 "JBD2: Invalid start block of journal: %u\n", 1543 be32_to_cpu(sb->s_first)); 1544 goto out; 1545 } 1546 1547 if (jbd2_has_feature_csum2(journal) && 1548 jbd2_has_feature_csum3(journal)) { 1549 /* Can't have checksum v2 and v3 at the same time! */ 1550 printk(KERN_ERR "JBD2: Can't enable checksumming v2 and v3 " 1551 "at the same time!\n"); 1552 goto out; 1553 } 1554 1555 if (jbd2_journal_has_csum_v2or3_feature(journal) && 1556 jbd2_has_feature_checksum(journal)) { 1557 /* Can't have checksum v1 and v2 on at the same time! */ 1558 printk(KERN_ERR "JBD2: Can't enable checksumming v1 and v2/3 " 1559 "at the same time!\n"); 1560 goto out; 1561 } 1562 1563 if (!jbd2_verify_csum_type(journal, sb)) { 1564 printk(KERN_ERR "JBD2: Unknown checksum type\n"); 1565 goto out; 1566 } 1567 1568 /* Load the checksum driver */ 1569 if (jbd2_journal_has_csum_v2or3_feature(journal)) { 1570 journal->j_chksum_driver = crypto_alloc_shash("crc32c", 0, 0); 1571 if (IS_ERR(journal->j_chksum_driver)) { 1572 printk(KERN_ERR "JBD2: Cannot load crc32c driver.\n"); 1573 err = PTR_ERR(journal->j_chksum_driver); 1574 journal->j_chksum_driver = NULL; 1575 goto out; 1576 } 1577 } 1578 1579 /* Check superblock checksum */ 1580 if (!jbd2_superblock_csum_verify(journal, sb)) { 1581 printk(KERN_ERR "JBD2: journal checksum error\n"); 1582 err = -EFSBADCRC; 1583 goto out; 1584 } 1585 1586 /* Precompute checksum seed for all metadata */ 1587 if (jbd2_journal_has_csum_v2or3(journal)) 1588 journal->j_csum_seed = jbd2_chksum(journal, ~0, sb->s_uuid, 1589 sizeof(sb->s_uuid)); 1590 1591 set_buffer_verified(bh); 1592 1593 return 0; 1594 1595 out: 1596 journal_fail_superblock(journal); 1597 return err; 1598 } 1599 1600 /* 1601 * Load the on-disk journal superblock and read the key fields into the 1602 * journal_t. 1603 */ 1604 1605 static int load_superblock(journal_t *journal) 1606 { 1607 int err; 1608 journal_superblock_t *sb; 1609 1610 err = journal_get_superblock(journal); 1611 if (err) 1612 return err; 1613 1614 sb = journal->j_superblock; 1615 1616 journal->j_tail_sequence = be32_to_cpu(sb->s_sequence); 1617 journal->j_tail = be32_to_cpu(sb->s_start); 1618 journal->j_first = be32_to_cpu(sb->s_first); 1619 journal->j_last = be32_to_cpu(sb->s_maxlen); 1620 journal->j_errno = be32_to_cpu(sb->s_errno); 1621 1622 return 0; 1623 } 1624 1625 1626 /** 1627 * int jbd2_journal_load() - Read journal from disk. 1628 * @journal: Journal to act on. 1629 * 1630 * Given a journal_t structure which tells us which disk blocks contain 1631 * a journal, read the journal from disk to initialise the in-memory 1632 * structures. 1633 */ 1634 int jbd2_journal_load(journal_t *journal) 1635 { 1636 int err; 1637 journal_superblock_t *sb; 1638 1639 err = load_superblock(journal); 1640 if (err) 1641 return err; 1642 1643 sb = journal->j_superblock; 1644 /* If this is a V2 superblock, then we have to check the 1645 * features flags on it. */ 1646 1647 if (journal->j_format_version >= 2) { 1648 if ((sb->s_feature_ro_compat & 1649 ~cpu_to_be32(JBD2_KNOWN_ROCOMPAT_FEATURES)) || 1650 (sb->s_feature_incompat & 1651 ~cpu_to_be32(JBD2_KNOWN_INCOMPAT_FEATURES))) { 1652 printk(KERN_WARNING 1653 "JBD2: Unrecognised features on journal\n"); 1654 return -EINVAL; 1655 } 1656 } 1657 1658 /* 1659 * Create a slab for this blocksize 1660 */ 1661 err = jbd2_journal_create_slab(be32_to_cpu(sb->s_blocksize)); 1662 if (err) 1663 return err; 1664 1665 /* Let the recovery code check whether it needs to recover any 1666 * data from the journal. */ 1667 if (jbd2_journal_recover(journal)) 1668 goto recovery_error; 1669 1670 if (journal->j_failed_commit) { 1671 printk(KERN_ERR "JBD2: journal transaction %u on %s " 1672 "is corrupt.\n", journal->j_failed_commit, 1673 journal->j_devname); 1674 return -EFSCORRUPTED; 1675 } 1676 1677 /* OK, we've finished with the dynamic journal bits: 1678 * reinitialise the dynamic contents of the superblock in memory 1679 * and reset them on disk. */ 1680 if (journal_reset(journal)) 1681 goto recovery_error; 1682 1683 journal->j_flags &= ~JBD2_ABORT; 1684 journal->j_flags |= JBD2_LOADED; 1685 return 0; 1686 1687 recovery_error: 1688 printk(KERN_WARNING "JBD2: recovery failed\n"); 1689 return -EIO; 1690 } 1691 1692 /** 1693 * void jbd2_journal_destroy() - Release a journal_t structure. 1694 * @journal: Journal to act on. 1695 * 1696 * Release a journal_t structure once it is no longer in use by the 1697 * journaled object. 1698 * Return <0 if we couldn't clean up the journal. 1699 */ 1700 int jbd2_journal_destroy(journal_t *journal) 1701 { 1702 int err = 0; 1703 1704 /* Wait for the commit thread to wake up and die. */ 1705 journal_kill_thread(journal); 1706 1707 /* Force a final log commit */ 1708 if (journal->j_running_transaction) 1709 jbd2_journal_commit_transaction(journal); 1710 1711 /* Force any old transactions to disk */ 1712 1713 /* Totally anal locking here... */ 1714 spin_lock(&journal->j_list_lock); 1715 while (journal->j_checkpoint_transactions != NULL) { 1716 spin_unlock(&journal->j_list_lock); 1717 mutex_lock_io(&journal->j_checkpoint_mutex); 1718 err = jbd2_log_do_checkpoint(journal); 1719 mutex_unlock(&journal->j_checkpoint_mutex); 1720 /* 1721 * If checkpointing failed, just free the buffers to avoid 1722 * looping forever 1723 */ 1724 if (err) { 1725 jbd2_journal_destroy_checkpoint(journal); 1726 spin_lock(&journal->j_list_lock); 1727 break; 1728 } 1729 spin_lock(&journal->j_list_lock); 1730 } 1731 1732 J_ASSERT(journal->j_running_transaction == NULL); 1733 J_ASSERT(journal->j_committing_transaction == NULL); 1734 J_ASSERT(journal->j_checkpoint_transactions == NULL); 1735 spin_unlock(&journal->j_list_lock); 1736 1737 if (journal->j_sb_buffer) { 1738 if (!is_journal_aborted(journal)) { 1739 mutex_lock_io(&journal->j_checkpoint_mutex); 1740 1741 write_lock(&journal->j_state_lock); 1742 journal->j_tail_sequence = 1743 ++journal->j_transaction_sequence; 1744 write_unlock(&journal->j_state_lock); 1745 1746 jbd2_mark_journal_empty(journal, 1747 REQ_SYNC | REQ_PREFLUSH | REQ_FUA); 1748 mutex_unlock(&journal->j_checkpoint_mutex); 1749 } else 1750 err = -EIO; 1751 brelse(journal->j_sb_buffer); 1752 } 1753 1754 if (journal->j_proc_entry) 1755 jbd2_stats_proc_exit(journal); 1756 iput(journal->j_inode); 1757 if (journal->j_revoke) 1758 jbd2_journal_destroy_revoke(journal); 1759 if (journal->j_chksum_driver) 1760 crypto_free_shash(journal->j_chksum_driver); 1761 kfree(journal->j_wbuf); 1762 kfree(journal); 1763 1764 return err; 1765 } 1766 1767 1768 /** 1769 *int jbd2_journal_check_used_features () - Check if features specified are used. 1770 * @journal: Journal to check. 1771 * @compat: bitmask of compatible features 1772 * @ro: bitmask of features that force read-only mount 1773 * @incompat: bitmask of incompatible features 1774 * 1775 * Check whether the journal uses all of a given set of 1776 * features. Return true (non-zero) if it does. 1777 **/ 1778 1779 int jbd2_journal_check_used_features (journal_t *journal, unsigned long compat, 1780 unsigned long ro, unsigned long incompat) 1781 { 1782 journal_superblock_t *sb; 1783 1784 if (!compat && !ro && !incompat) 1785 return 1; 1786 /* Load journal superblock if it is not loaded yet. */ 1787 if (journal->j_format_version == 0 && 1788 journal_get_superblock(journal) != 0) 1789 return 0; 1790 if (journal->j_format_version == 1) 1791 return 0; 1792 1793 sb = journal->j_superblock; 1794 1795 if (((be32_to_cpu(sb->s_feature_compat) & compat) == compat) && 1796 ((be32_to_cpu(sb->s_feature_ro_compat) & ro) == ro) && 1797 ((be32_to_cpu(sb->s_feature_incompat) & incompat) == incompat)) 1798 return 1; 1799 1800 return 0; 1801 } 1802 1803 /** 1804 * int jbd2_journal_check_available_features() - Check feature set in journalling layer 1805 * @journal: Journal to check. 1806 * @compat: bitmask of compatible features 1807 * @ro: bitmask of features that force read-only mount 1808 * @incompat: bitmask of incompatible features 1809 * 1810 * Check whether the journaling code supports the use of 1811 * all of a given set of features on this journal. Return true 1812 * (non-zero) if it can. */ 1813 1814 int jbd2_journal_check_available_features (journal_t *journal, unsigned long compat, 1815 unsigned long ro, unsigned long incompat) 1816 { 1817 if (!compat && !ro && !incompat) 1818 return 1; 1819 1820 /* We can support any known requested features iff the 1821 * superblock is in version 2. Otherwise we fail to support any 1822 * extended sb features. */ 1823 1824 if (journal->j_format_version != 2) 1825 return 0; 1826 1827 if ((compat & JBD2_KNOWN_COMPAT_FEATURES) == compat && 1828 (ro & JBD2_KNOWN_ROCOMPAT_FEATURES) == ro && 1829 (incompat & JBD2_KNOWN_INCOMPAT_FEATURES) == incompat) 1830 return 1; 1831 1832 return 0; 1833 } 1834 1835 /** 1836 * int jbd2_journal_set_features () - Mark a given journal feature in the superblock 1837 * @journal: Journal to act on. 1838 * @compat: bitmask of compatible features 1839 * @ro: bitmask of features that force read-only mount 1840 * @incompat: bitmask of incompatible features 1841 * 1842 * Mark a given journal feature as present on the 1843 * superblock. Returns true if the requested features could be set. 1844 * 1845 */ 1846 1847 int jbd2_journal_set_features (journal_t *journal, unsigned long compat, 1848 unsigned long ro, unsigned long incompat) 1849 { 1850 #define INCOMPAT_FEATURE_ON(f) \ 1851 ((incompat & (f)) && !(sb->s_feature_incompat & cpu_to_be32(f))) 1852 #define COMPAT_FEATURE_ON(f) \ 1853 ((compat & (f)) && !(sb->s_feature_compat & cpu_to_be32(f))) 1854 journal_superblock_t *sb; 1855 1856 if (jbd2_journal_check_used_features(journal, compat, ro, incompat)) 1857 return 1; 1858 1859 if (!jbd2_journal_check_available_features(journal, compat, ro, incompat)) 1860 return 0; 1861 1862 /* If enabling v2 checksums, turn on v3 instead */ 1863 if (incompat & JBD2_FEATURE_INCOMPAT_CSUM_V2) { 1864 incompat &= ~JBD2_FEATURE_INCOMPAT_CSUM_V2; 1865 incompat |= JBD2_FEATURE_INCOMPAT_CSUM_V3; 1866 } 1867 1868 /* Asking for checksumming v3 and v1? Only give them v3. */ 1869 if (incompat & JBD2_FEATURE_INCOMPAT_CSUM_V3 && 1870 compat & JBD2_FEATURE_COMPAT_CHECKSUM) 1871 compat &= ~JBD2_FEATURE_COMPAT_CHECKSUM; 1872 1873 jbd_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n", 1874 compat, ro, incompat); 1875 1876 sb = journal->j_superblock; 1877 1878 /* If enabling v3 checksums, update superblock */ 1879 if (INCOMPAT_FEATURE_ON(JBD2_FEATURE_INCOMPAT_CSUM_V3)) { 1880 sb->s_checksum_type = JBD2_CRC32C_CHKSUM; 1881 sb->s_feature_compat &= 1882 ~cpu_to_be32(JBD2_FEATURE_COMPAT_CHECKSUM); 1883 1884 /* Load the checksum driver */ 1885 if (journal->j_chksum_driver == NULL) { 1886 journal->j_chksum_driver = crypto_alloc_shash("crc32c", 1887 0, 0); 1888 if (IS_ERR(journal->j_chksum_driver)) { 1889 printk(KERN_ERR "JBD2: Cannot load crc32c " 1890 "driver.\n"); 1891 journal->j_chksum_driver = NULL; 1892 return 0; 1893 } 1894 1895 /* Precompute checksum seed for all metadata */ 1896 journal->j_csum_seed = jbd2_chksum(journal, ~0, 1897 sb->s_uuid, 1898 sizeof(sb->s_uuid)); 1899 } 1900 } 1901 1902 /* If enabling v1 checksums, downgrade superblock */ 1903 if (COMPAT_FEATURE_ON(JBD2_FEATURE_COMPAT_CHECKSUM)) 1904 sb->s_feature_incompat &= 1905 ~cpu_to_be32(JBD2_FEATURE_INCOMPAT_CSUM_V2 | 1906 JBD2_FEATURE_INCOMPAT_CSUM_V3); 1907 1908 sb->s_feature_compat |= cpu_to_be32(compat); 1909 sb->s_feature_ro_compat |= cpu_to_be32(ro); 1910 sb->s_feature_incompat |= cpu_to_be32(incompat); 1911 1912 return 1; 1913 #undef COMPAT_FEATURE_ON 1914 #undef INCOMPAT_FEATURE_ON 1915 } 1916 1917 /* 1918 * jbd2_journal_clear_features () - Clear a given journal feature in the 1919 * superblock 1920 * @journal: Journal to act on. 1921 * @compat: bitmask of compatible features 1922 * @ro: bitmask of features that force read-only mount 1923 * @incompat: bitmask of incompatible features 1924 * 1925 * Clear a given journal feature as present on the 1926 * superblock. 1927 */ 1928 void jbd2_journal_clear_features(journal_t *journal, unsigned long compat, 1929 unsigned long ro, unsigned long incompat) 1930 { 1931 journal_superblock_t *sb; 1932 1933 jbd_debug(1, "Clear features 0x%lx/0x%lx/0x%lx\n", 1934 compat, ro, incompat); 1935 1936 sb = journal->j_superblock; 1937 1938 sb->s_feature_compat &= ~cpu_to_be32(compat); 1939 sb->s_feature_ro_compat &= ~cpu_to_be32(ro); 1940 sb->s_feature_incompat &= ~cpu_to_be32(incompat); 1941 } 1942 EXPORT_SYMBOL(jbd2_journal_clear_features); 1943 1944 /** 1945 * int jbd2_journal_flush () - Flush journal 1946 * @journal: Journal to act on. 1947 * 1948 * Flush all data for a given journal to disk and empty the journal. 1949 * Filesystems can use this when remounting readonly to ensure that 1950 * recovery does not need to happen on remount. 1951 */ 1952 1953 int jbd2_journal_flush(journal_t *journal) 1954 { 1955 int err = 0; 1956 transaction_t *transaction = NULL; 1957 1958 write_lock(&journal->j_state_lock); 1959 1960 /* Force everything buffered to the log... */ 1961 if (journal->j_running_transaction) { 1962 transaction = journal->j_running_transaction; 1963 __jbd2_log_start_commit(journal, transaction->t_tid); 1964 } else if (journal->j_committing_transaction) 1965 transaction = journal->j_committing_transaction; 1966 1967 /* Wait for the log commit to complete... */ 1968 if (transaction) { 1969 tid_t tid = transaction->t_tid; 1970 1971 write_unlock(&journal->j_state_lock); 1972 jbd2_log_wait_commit(journal, tid); 1973 } else { 1974 write_unlock(&journal->j_state_lock); 1975 } 1976 1977 /* ...and flush everything in the log out to disk. */ 1978 spin_lock(&journal->j_list_lock); 1979 while (!err && journal->j_checkpoint_transactions != NULL) { 1980 spin_unlock(&journal->j_list_lock); 1981 mutex_lock_io(&journal->j_checkpoint_mutex); 1982 err = jbd2_log_do_checkpoint(journal); 1983 mutex_unlock(&journal->j_checkpoint_mutex); 1984 spin_lock(&journal->j_list_lock); 1985 } 1986 spin_unlock(&journal->j_list_lock); 1987 1988 if (is_journal_aborted(journal)) 1989 return -EIO; 1990 1991 mutex_lock_io(&journal->j_checkpoint_mutex); 1992 if (!err) { 1993 err = jbd2_cleanup_journal_tail(journal); 1994 if (err < 0) { 1995 mutex_unlock(&journal->j_checkpoint_mutex); 1996 goto out; 1997 } 1998 err = 0; 1999 } 2000 2001 /* Finally, mark the journal as really needing no recovery. 2002 * This sets s_start==0 in the underlying superblock, which is 2003 * the magic code for a fully-recovered superblock. Any future 2004 * commits of data to the journal will restore the current 2005 * s_start value. */ 2006 jbd2_mark_journal_empty(journal, REQ_SYNC | REQ_FUA); 2007 mutex_unlock(&journal->j_checkpoint_mutex); 2008 write_lock(&journal->j_state_lock); 2009 J_ASSERT(!journal->j_running_transaction); 2010 J_ASSERT(!journal->j_committing_transaction); 2011 J_ASSERT(!journal->j_checkpoint_transactions); 2012 J_ASSERT(journal->j_head == journal->j_tail); 2013 J_ASSERT(journal->j_tail_sequence == journal->j_transaction_sequence); 2014 write_unlock(&journal->j_state_lock); 2015 out: 2016 return err; 2017 } 2018 2019 /** 2020 * int jbd2_journal_wipe() - Wipe journal contents 2021 * @journal: Journal to act on. 2022 * @write: flag (see below) 2023 * 2024 * Wipe out all of the contents of a journal, safely. This will produce 2025 * a warning if the journal contains any valid recovery information. 2026 * Must be called between journal_init_*() and jbd2_journal_load(). 2027 * 2028 * If 'write' is non-zero, then we wipe out the journal on disk; otherwise 2029 * we merely suppress recovery. 2030 */ 2031 2032 int jbd2_journal_wipe(journal_t *journal, int write) 2033 { 2034 int err = 0; 2035 2036 J_ASSERT (!(journal->j_flags & JBD2_LOADED)); 2037 2038 err = load_superblock(journal); 2039 if (err) 2040 return err; 2041 2042 if (!journal->j_tail) 2043 goto no_recovery; 2044 2045 printk(KERN_WARNING "JBD2: %s recovery information on journal\n", 2046 write ? "Clearing" : "Ignoring"); 2047 2048 err = jbd2_journal_skip_recovery(journal); 2049 if (write) { 2050 /* Lock to make assertions happy... */ 2051 mutex_lock(&journal->j_checkpoint_mutex); 2052 jbd2_mark_journal_empty(journal, REQ_SYNC | REQ_FUA); 2053 mutex_unlock(&journal->j_checkpoint_mutex); 2054 } 2055 2056 no_recovery: 2057 return err; 2058 } 2059 2060 /* 2061 * Journal abort has very specific semantics, which we describe 2062 * for journal abort. 2063 * 2064 * Two internal functions, which provide abort to the jbd layer 2065 * itself are here. 2066 */ 2067 2068 /* 2069 * Quick version for internal journal use (doesn't lock the journal). 2070 * Aborts hard --- we mark the abort as occurred, but do _nothing_ else, 2071 * and don't attempt to make any other journal updates. 2072 */ 2073 void __jbd2_journal_abort_hard(journal_t *journal) 2074 { 2075 transaction_t *transaction; 2076 2077 if (journal->j_flags & JBD2_ABORT) 2078 return; 2079 2080 printk(KERN_ERR "Aborting journal on device %s.\n", 2081 journal->j_devname); 2082 2083 write_lock(&journal->j_state_lock); 2084 journal->j_flags |= JBD2_ABORT; 2085 transaction = journal->j_running_transaction; 2086 if (transaction) 2087 __jbd2_log_start_commit(journal, transaction->t_tid); 2088 write_unlock(&journal->j_state_lock); 2089 } 2090 2091 /* Soft abort: record the abort error status in the journal superblock, 2092 * but don't do any other IO. */ 2093 static void __journal_abort_soft (journal_t *journal, int errno) 2094 { 2095 if (journal->j_flags & JBD2_ABORT) 2096 return; 2097 2098 if (!journal->j_errno) 2099 journal->j_errno = errno; 2100 2101 __jbd2_journal_abort_hard(journal); 2102 2103 if (errno) { 2104 jbd2_journal_update_sb_errno(journal); 2105 write_lock(&journal->j_state_lock); 2106 journal->j_flags |= JBD2_REC_ERR; 2107 write_unlock(&journal->j_state_lock); 2108 } 2109 } 2110 2111 /** 2112 * void jbd2_journal_abort () - Shutdown the journal immediately. 2113 * @journal: the journal to shutdown. 2114 * @errno: an error number to record in the journal indicating 2115 * the reason for the shutdown. 2116 * 2117 * Perform a complete, immediate shutdown of the ENTIRE 2118 * journal (not of a single transaction). This operation cannot be 2119 * undone without closing and reopening the journal. 2120 * 2121 * The jbd2_journal_abort function is intended to support higher level error 2122 * recovery mechanisms such as the ext2/ext3 remount-readonly error 2123 * mode. 2124 * 2125 * Journal abort has very specific semantics. Any existing dirty, 2126 * unjournaled buffers in the main filesystem will still be written to 2127 * disk by bdflush, but the journaling mechanism will be suspended 2128 * immediately and no further transaction commits will be honoured. 2129 * 2130 * Any dirty, journaled buffers will be written back to disk without 2131 * hitting the journal. Atomicity cannot be guaranteed on an aborted 2132 * filesystem, but we _do_ attempt to leave as much data as possible 2133 * behind for fsck to use for cleanup. 2134 * 2135 * Any attempt to get a new transaction handle on a journal which is in 2136 * ABORT state will just result in an -EROFS error return. A 2137 * jbd2_journal_stop on an existing handle will return -EIO if we have 2138 * entered abort state during the update. 2139 * 2140 * Recursive transactions are not disturbed by journal abort until the 2141 * final jbd2_journal_stop, which will receive the -EIO error. 2142 * 2143 * Finally, the jbd2_journal_abort call allows the caller to supply an errno 2144 * which will be recorded (if possible) in the journal superblock. This 2145 * allows a client to record failure conditions in the middle of a 2146 * transaction without having to complete the transaction to record the 2147 * failure to disk. ext3_error, for example, now uses this 2148 * functionality. 2149 * 2150 * Errors which originate from within the journaling layer will NOT 2151 * supply an errno; a null errno implies that absolutely no further 2152 * writes are done to the journal (unless there are any already in 2153 * progress). 2154 * 2155 */ 2156 2157 void jbd2_journal_abort(journal_t *journal, int errno) 2158 { 2159 __journal_abort_soft(journal, errno); 2160 } 2161 2162 /** 2163 * int jbd2_journal_errno () - returns the journal's error state. 2164 * @journal: journal to examine. 2165 * 2166 * This is the errno number set with jbd2_journal_abort(), the last 2167 * time the journal was mounted - if the journal was stopped 2168 * without calling abort this will be 0. 2169 * 2170 * If the journal has been aborted on this mount time -EROFS will 2171 * be returned. 2172 */ 2173 int jbd2_journal_errno(journal_t *journal) 2174 { 2175 int err; 2176 2177 read_lock(&journal->j_state_lock); 2178 if (journal->j_flags & JBD2_ABORT) 2179 err = -EROFS; 2180 else 2181 err = journal->j_errno; 2182 read_unlock(&journal->j_state_lock); 2183 return err; 2184 } 2185 2186 /** 2187 * int jbd2_journal_clear_err () - clears the journal's error state 2188 * @journal: journal to act on. 2189 * 2190 * An error must be cleared or acked to take a FS out of readonly 2191 * mode. 2192 */ 2193 int jbd2_journal_clear_err(journal_t *journal) 2194 { 2195 int err = 0; 2196 2197 write_lock(&journal->j_state_lock); 2198 if (journal->j_flags & JBD2_ABORT) 2199 err = -EROFS; 2200 else 2201 journal->j_errno = 0; 2202 write_unlock(&journal->j_state_lock); 2203 return err; 2204 } 2205 2206 /** 2207 * void jbd2_journal_ack_err() - Ack journal err. 2208 * @journal: journal to act on. 2209 * 2210 * An error must be cleared or acked to take a FS out of readonly 2211 * mode. 2212 */ 2213 void jbd2_journal_ack_err(journal_t *journal) 2214 { 2215 write_lock(&journal->j_state_lock); 2216 if (journal->j_errno) 2217 journal->j_flags |= JBD2_ACK_ERR; 2218 write_unlock(&journal->j_state_lock); 2219 } 2220 2221 int jbd2_journal_blocks_per_page(struct inode *inode) 2222 { 2223 return 1 << (PAGE_SHIFT - inode->i_sb->s_blocksize_bits); 2224 } 2225 2226 /* 2227 * helper functions to deal with 32 or 64bit block numbers. 2228 */ 2229 size_t journal_tag_bytes(journal_t *journal) 2230 { 2231 size_t sz; 2232 2233 if (jbd2_has_feature_csum3(journal)) 2234 return sizeof(journal_block_tag3_t); 2235 2236 sz = sizeof(journal_block_tag_t); 2237 2238 if (jbd2_has_feature_csum2(journal)) 2239 sz += sizeof(__u16); 2240 2241 if (jbd2_has_feature_64bit(journal)) 2242 return sz; 2243 else 2244 return sz - sizeof(__u32); 2245 } 2246 2247 /* 2248 * JBD memory management 2249 * 2250 * These functions are used to allocate block-sized chunks of memory 2251 * used for making copies of buffer_head data. Very often it will be 2252 * page-sized chunks of data, but sometimes it will be in 2253 * sub-page-size chunks. (For example, 16k pages on Power systems 2254 * with a 4k block file system.) For blocks smaller than a page, we 2255 * use a SLAB allocator. There are slab caches for each block size, 2256 * which are allocated at mount time, if necessary, and we only free 2257 * (all of) the slab caches when/if the jbd2 module is unloaded. For 2258 * this reason we don't need to a mutex to protect access to 2259 * jbd2_slab[] allocating or releasing memory; only in 2260 * jbd2_journal_create_slab(). 2261 */ 2262 #define JBD2_MAX_SLABS 8 2263 static struct kmem_cache *jbd2_slab[JBD2_MAX_SLABS]; 2264 2265 static const char *jbd2_slab_names[JBD2_MAX_SLABS] = { 2266 "jbd2_1k", "jbd2_2k", "jbd2_4k", "jbd2_8k", 2267 "jbd2_16k", "jbd2_32k", "jbd2_64k", "jbd2_128k" 2268 }; 2269 2270 2271 static void jbd2_journal_destroy_slabs(void) 2272 { 2273 int i; 2274 2275 for (i = 0; i < JBD2_MAX_SLABS; i++) { 2276 if (jbd2_slab[i]) 2277 kmem_cache_destroy(jbd2_slab[i]); 2278 jbd2_slab[i] = NULL; 2279 } 2280 } 2281 2282 static int jbd2_journal_create_slab(size_t size) 2283 { 2284 static DEFINE_MUTEX(jbd2_slab_create_mutex); 2285 int i = order_base_2(size) - 10; 2286 size_t slab_size; 2287 2288 if (size == PAGE_SIZE) 2289 return 0; 2290 2291 if (i >= JBD2_MAX_SLABS) 2292 return -EINVAL; 2293 2294 if (unlikely(i < 0)) 2295 i = 0; 2296 mutex_lock(&jbd2_slab_create_mutex); 2297 if (jbd2_slab[i]) { 2298 mutex_unlock(&jbd2_slab_create_mutex); 2299 return 0; /* Already created */ 2300 } 2301 2302 slab_size = 1 << (i+10); 2303 jbd2_slab[i] = kmem_cache_create(jbd2_slab_names[i], slab_size, 2304 slab_size, 0, NULL); 2305 mutex_unlock(&jbd2_slab_create_mutex); 2306 if (!jbd2_slab[i]) { 2307 printk(KERN_EMERG "JBD2: no memory for jbd2_slab cache\n"); 2308 return -ENOMEM; 2309 } 2310 return 0; 2311 } 2312 2313 static struct kmem_cache *get_slab(size_t size) 2314 { 2315 int i = order_base_2(size) - 10; 2316 2317 BUG_ON(i >= JBD2_MAX_SLABS); 2318 if (unlikely(i < 0)) 2319 i = 0; 2320 BUG_ON(jbd2_slab[i] == NULL); 2321 return jbd2_slab[i]; 2322 } 2323 2324 void *jbd2_alloc(size_t size, gfp_t flags) 2325 { 2326 void *ptr; 2327 2328 BUG_ON(size & (size-1)); /* Must be a power of 2 */ 2329 2330 if (size < PAGE_SIZE) 2331 ptr = kmem_cache_alloc(get_slab(size), flags); 2332 else 2333 ptr = (void *)__get_free_pages(flags, get_order(size)); 2334 2335 /* Check alignment; SLUB has gotten this wrong in the past, 2336 * and this can lead to user data corruption! */ 2337 BUG_ON(((unsigned long) ptr) & (size-1)); 2338 2339 return ptr; 2340 } 2341 2342 void jbd2_free(void *ptr, size_t size) 2343 { 2344 if (size < PAGE_SIZE) 2345 kmem_cache_free(get_slab(size), ptr); 2346 else 2347 free_pages((unsigned long)ptr, get_order(size)); 2348 }; 2349 2350 /* 2351 * Journal_head storage management 2352 */ 2353 static struct kmem_cache *jbd2_journal_head_cache; 2354 #ifdef CONFIG_JBD2_DEBUG 2355 static atomic_t nr_journal_heads = ATOMIC_INIT(0); 2356 #endif 2357 2358 static int jbd2_journal_init_journal_head_cache(void) 2359 { 2360 int retval; 2361 2362 J_ASSERT(jbd2_journal_head_cache == NULL); 2363 jbd2_journal_head_cache = kmem_cache_create("jbd2_journal_head", 2364 sizeof(struct journal_head), 2365 0, /* offset */ 2366 SLAB_TEMPORARY | SLAB_TYPESAFE_BY_RCU, 2367 NULL); /* ctor */ 2368 retval = 0; 2369 if (!jbd2_journal_head_cache) { 2370 retval = -ENOMEM; 2371 printk(KERN_EMERG "JBD2: no memory for journal_head cache\n"); 2372 } 2373 return retval; 2374 } 2375 2376 static void jbd2_journal_destroy_journal_head_cache(void) 2377 { 2378 if (jbd2_journal_head_cache) { 2379 kmem_cache_destroy(jbd2_journal_head_cache); 2380 jbd2_journal_head_cache = NULL; 2381 } 2382 } 2383 2384 /* 2385 * journal_head splicing and dicing 2386 */ 2387 static struct journal_head *journal_alloc_journal_head(void) 2388 { 2389 struct journal_head *ret; 2390 2391 #ifdef CONFIG_JBD2_DEBUG 2392 atomic_inc(&nr_journal_heads); 2393 #endif 2394 ret = kmem_cache_zalloc(jbd2_journal_head_cache, GFP_NOFS); 2395 if (!ret) { 2396 jbd_debug(1, "out of memory for journal_head\n"); 2397 pr_notice_ratelimited("ENOMEM in %s, retrying.\n", __func__); 2398 ret = kmem_cache_zalloc(jbd2_journal_head_cache, 2399 GFP_NOFS | __GFP_NOFAIL); 2400 } 2401 return ret; 2402 } 2403 2404 static void journal_free_journal_head(struct journal_head *jh) 2405 { 2406 #ifdef CONFIG_JBD2_DEBUG 2407 atomic_dec(&nr_journal_heads); 2408 memset(jh, JBD2_POISON_FREE, sizeof(*jh)); 2409 #endif 2410 kmem_cache_free(jbd2_journal_head_cache, jh); 2411 } 2412 2413 /* 2414 * A journal_head is attached to a buffer_head whenever JBD has an 2415 * interest in the buffer. 2416 * 2417 * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit 2418 * is set. This bit is tested in core kernel code where we need to take 2419 * JBD-specific actions. Testing the zeroness of ->b_private is not reliable 2420 * there. 2421 * 2422 * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one. 2423 * 2424 * When a buffer has its BH_JBD bit set it is immune from being released by 2425 * core kernel code, mainly via ->b_count. 2426 * 2427 * A journal_head is detached from its buffer_head when the journal_head's 2428 * b_jcount reaches zero. Running transaction (b_transaction) and checkpoint 2429 * transaction (b_cp_transaction) hold their references to b_jcount. 2430 * 2431 * Various places in the kernel want to attach a journal_head to a buffer_head 2432 * _before_ attaching the journal_head to a transaction. To protect the 2433 * journal_head in this situation, jbd2_journal_add_journal_head elevates the 2434 * journal_head's b_jcount refcount by one. The caller must call 2435 * jbd2_journal_put_journal_head() to undo this. 2436 * 2437 * So the typical usage would be: 2438 * 2439 * (Attach a journal_head if needed. Increments b_jcount) 2440 * struct journal_head *jh = jbd2_journal_add_journal_head(bh); 2441 * ... 2442 * (Get another reference for transaction) 2443 * jbd2_journal_grab_journal_head(bh); 2444 * jh->b_transaction = xxx; 2445 * (Put original reference) 2446 * jbd2_journal_put_journal_head(jh); 2447 */ 2448 2449 /* 2450 * Give a buffer_head a journal_head. 2451 * 2452 * May sleep. 2453 */ 2454 struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh) 2455 { 2456 struct journal_head *jh; 2457 struct journal_head *new_jh = NULL; 2458 2459 repeat: 2460 if (!buffer_jbd(bh)) 2461 new_jh = journal_alloc_journal_head(); 2462 2463 jbd_lock_bh_journal_head(bh); 2464 if (buffer_jbd(bh)) { 2465 jh = bh2jh(bh); 2466 } else { 2467 J_ASSERT_BH(bh, 2468 (atomic_read(&bh->b_count) > 0) || 2469 (bh->b_page && bh->b_page->mapping)); 2470 2471 if (!new_jh) { 2472 jbd_unlock_bh_journal_head(bh); 2473 goto repeat; 2474 } 2475 2476 jh = new_jh; 2477 new_jh = NULL; /* We consumed it */ 2478 set_buffer_jbd(bh); 2479 bh->b_private = jh; 2480 jh->b_bh = bh; 2481 get_bh(bh); 2482 BUFFER_TRACE(bh, "added journal_head"); 2483 } 2484 jh->b_jcount++; 2485 jbd_unlock_bh_journal_head(bh); 2486 if (new_jh) 2487 journal_free_journal_head(new_jh); 2488 return bh->b_private; 2489 } 2490 2491 /* 2492 * Grab a ref against this buffer_head's journal_head. If it ended up not 2493 * having a journal_head, return NULL 2494 */ 2495 struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh) 2496 { 2497 struct journal_head *jh = NULL; 2498 2499 jbd_lock_bh_journal_head(bh); 2500 if (buffer_jbd(bh)) { 2501 jh = bh2jh(bh); 2502 jh->b_jcount++; 2503 } 2504 jbd_unlock_bh_journal_head(bh); 2505 return jh; 2506 } 2507 2508 static void __journal_remove_journal_head(struct buffer_head *bh) 2509 { 2510 struct journal_head *jh = bh2jh(bh); 2511 2512 J_ASSERT_JH(jh, jh->b_jcount >= 0); 2513 J_ASSERT_JH(jh, jh->b_transaction == NULL); 2514 J_ASSERT_JH(jh, jh->b_next_transaction == NULL); 2515 J_ASSERT_JH(jh, jh->b_cp_transaction == NULL); 2516 J_ASSERT_JH(jh, jh->b_jlist == BJ_None); 2517 J_ASSERT_BH(bh, buffer_jbd(bh)); 2518 J_ASSERT_BH(bh, jh2bh(jh) == bh); 2519 BUFFER_TRACE(bh, "remove journal_head"); 2520 if (jh->b_frozen_data) { 2521 printk(KERN_WARNING "%s: freeing b_frozen_data\n", __func__); 2522 jbd2_free(jh->b_frozen_data, bh->b_size); 2523 } 2524 if (jh->b_committed_data) { 2525 printk(KERN_WARNING "%s: freeing b_committed_data\n", __func__); 2526 jbd2_free(jh->b_committed_data, bh->b_size); 2527 } 2528 bh->b_private = NULL; 2529 jh->b_bh = NULL; /* debug, really */ 2530 clear_buffer_jbd(bh); 2531 journal_free_journal_head(jh); 2532 } 2533 2534 /* 2535 * Drop a reference on the passed journal_head. If it fell to zero then 2536 * release the journal_head from the buffer_head. 2537 */ 2538 void jbd2_journal_put_journal_head(struct journal_head *jh) 2539 { 2540 struct buffer_head *bh = jh2bh(jh); 2541 2542 jbd_lock_bh_journal_head(bh); 2543 J_ASSERT_JH(jh, jh->b_jcount > 0); 2544 --jh->b_jcount; 2545 if (!jh->b_jcount) { 2546 __journal_remove_journal_head(bh); 2547 jbd_unlock_bh_journal_head(bh); 2548 __brelse(bh); 2549 } else 2550 jbd_unlock_bh_journal_head(bh); 2551 } 2552 2553 /* 2554 * Initialize jbd inode head 2555 */ 2556 void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode) 2557 { 2558 jinode->i_transaction = NULL; 2559 jinode->i_next_transaction = NULL; 2560 jinode->i_vfs_inode = inode; 2561 jinode->i_flags = 0; 2562 INIT_LIST_HEAD(&jinode->i_list); 2563 } 2564 2565 /* 2566 * Function to be called before we start removing inode from memory (i.e., 2567 * clear_inode() is a fine place to be called from). It removes inode from 2568 * transaction's lists. 2569 */ 2570 void jbd2_journal_release_jbd_inode(journal_t *journal, 2571 struct jbd2_inode *jinode) 2572 { 2573 if (!journal) 2574 return; 2575 restart: 2576 spin_lock(&journal->j_list_lock); 2577 /* Is commit writing out inode - we have to wait */ 2578 if (jinode->i_flags & JI_COMMIT_RUNNING) { 2579 wait_queue_head_t *wq; 2580 DEFINE_WAIT_BIT(wait, &jinode->i_flags, __JI_COMMIT_RUNNING); 2581 wq = bit_waitqueue(&jinode->i_flags, __JI_COMMIT_RUNNING); 2582 prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE); 2583 spin_unlock(&journal->j_list_lock); 2584 schedule(); 2585 finish_wait(wq, &wait.wq_entry); 2586 goto restart; 2587 } 2588 2589 if (jinode->i_transaction) { 2590 list_del(&jinode->i_list); 2591 jinode->i_transaction = NULL; 2592 } 2593 spin_unlock(&journal->j_list_lock); 2594 } 2595 2596 2597 #ifdef CONFIG_PROC_FS 2598 2599 #define JBD2_STATS_PROC_NAME "fs/jbd2" 2600 2601 static void __init jbd2_create_jbd_stats_proc_entry(void) 2602 { 2603 proc_jbd2_stats = proc_mkdir(JBD2_STATS_PROC_NAME, NULL); 2604 } 2605 2606 static void __exit jbd2_remove_jbd_stats_proc_entry(void) 2607 { 2608 if (proc_jbd2_stats) 2609 remove_proc_entry(JBD2_STATS_PROC_NAME, NULL); 2610 } 2611 2612 #else 2613 2614 #define jbd2_create_jbd_stats_proc_entry() do {} while (0) 2615 #define jbd2_remove_jbd_stats_proc_entry() do {} while (0) 2616 2617 #endif 2618 2619 struct kmem_cache *jbd2_handle_cache, *jbd2_inode_cache; 2620 2621 static int __init jbd2_journal_init_handle_cache(void) 2622 { 2623 jbd2_handle_cache = KMEM_CACHE(jbd2_journal_handle, SLAB_TEMPORARY); 2624 if (jbd2_handle_cache == NULL) { 2625 printk(KERN_EMERG "JBD2: failed to create handle cache\n"); 2626 return -ENOMEM; 2627 } 2628 jbd2_inode_cache = KMEM_CACHE(jbd2_inode, 0); 2629 if (jbd2_inode_cache == NULL) { 2630 printk(KERN_EMERG "JBD2: failed to create inode cache\n"); 2631 kmem_cache_destroy(jbd2_handle_cache); 2632 return -ENOMEM; 2633 } 2634 return 0; 2635 } 2636 2637 static void jbd2_journal_destroy_handle_cache(void) 2638 { 2639 if (jbd2_handle_cache) 2640 kmem_cache_destroy(jbd2_handle_cache); 2641 if (jbd2_inode_cache) 2642 kmem_cache_destroy(jbd2_inode_cache); 2643 2644 } 2645 2646 /* 2647 * Module startup and shutdown 2648 */ 2649 2650 static int __init journal_init_caches(void) 2651 { 2652 int ret; 2653 2654 ret = jbd2_journal_init_revoke_caches(); 2655 if (ret == 0) 2656 ret = jbd2_journal_init_journal_head_cache(); 2657 if (ret == 0) 2658 ret = jbd2_journal_init_handle_cache(); 2659 if (ret == 0) 2660 ret = jbd2_journal_init_transaction_cache(); 2661 return ret; 2662 } 2663 2664 static void jbd2_journal_destroy_caches(void) 2665 { 2666 jbd2_journal_destroy_revoke_caches(); 2667 jbd2_journal_destroy_journal_head_cache(); 2668 jbd2_journal_destroy_handle_cache(); 2669 jbd2_journal_destroy_transaction_cache(); 2670 jbd2_journal_destroy_slabs(); 2671 } 2672 2673 static int __init journal_init(void) 2674 { 2675 int ret; 2676 2677 BUILD_BUG_ON(sizeof(struct journal_superblock_s) != 1024); 2678 2679 ret = journal_init_caches(); 2680 if (ret == 0) { 2681 jbd2_create_jbd_stats_proc_entry(); 2682 } else { 2683 jbd2_journal_destroy_caches(); 2684 } 2685 return ret; 2686 } 2687 2688 static void __exit journal_exit(void) 2689 { 2690 #ifdef CONFIG_JBD2_DEBUG 2691 int n = atomic_read(&nr_journal_heads); 2692 if (n) 2693 printk(KERN_ERR "JBD2: leaked %d journal_heads!\n", n); 2694 #endif 2695 jbd2_remove_jbd_stats_proc_entry(); 2696 jbd2_journal_destroy_caches(); 2697 } 2698 2699 MODULE_LICENSE("GPL"); 2700 module_init(journal_init); 2701 module_exit(journal_exit); 2702 2703