1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * linux/fs/jbd2/journal.c 4 * 5 * Written by Stephen C. Tweedie <sct@redhat.com>, 1998 6 * 7 * Copyright 1998 Red Hat corp --- All Rights Reserved 8 * 9 * Generic filesystem journal-writing code; part of the ext2fs 10 * journaling system. 11 * 12 * This file manages journals: areas of disk reserved for logging 13 * transactional updates. This includes the kernel journaling thread 14 * which is responsible for scheduling updates to the log. 15 * 16 * We do not actually manage the physical storage of the journal in this 17 * file: that is left to a per-journal policy function, which allows us 18 * to store the journal within a filesystem-specified area for ext2 19 * journaling (ext2 can use a reserved inode for storing the log). 20 */ 21 22 #include <linux/module.h> 23 #include <linux/time.h> 24 #include <linux/fs.h> 25 #include <linux/jbd2.h> 26 #include <linux/errno.h> 27 #include <linux/slab.h> 28 #include <linux/init.h> 29 #include <linux/mm.h> 30 #include <linux/freezer.h> 31 #include <linux/pagemap.h> 32 #include <linux/kthread.h> 33 #include <linux/poison.h> 34 #include <linux/proc_fs.h> 35 #include <linux/seq_file.h> 36 #include <linux/math64.h> 37 #include <linux/hash.h> 38 #include <linux/log2.h> 39 #include <linux/vmalloc.h> 40 #include <linux/backing-dev.h> 41 #include <linux/bitops.h> 42 #include <linux/ratelimit.h> 43 #include <linux/sched/mm.h> 44 45 #define CREATE_TRACE_POINTS 46 #include <trace/events/jbd2.h> 47 48 #include <linux/uaccess.h> 49 #include <asm/page.h> 50 51 #ifdef CONFIG_JBD2_DEBUG 52 static ushort jbd2_journal_enable_debug __read_mostly; 53 54 module_param_named(jbd2_debug, jbd2_journal_enable_debug, ushort, 0644); 55 MODULE_PARM_DESC(jbd2_debug, "Debugging level for jbd2"); 56 #endif 57 58 EXPORT_SYMBOL(jbd2_journal_extend); 59 EXPORT_SYMBOL(jbd2_journal_stop); 60 EXPORT_SYMBOL(jbd2_journal_lock_updates); 61 EXPORT_SYMBOL(jbd2_journal_unlock_updates); 62 EXPORT_SYMBOL(jbd2_journal_get_write_access); 63 EXPORT_SYMBOL(jbd2_journal_get_create_access); 64 EXPORT_SYMBOL(jbd2_journal_get_undo_access); 65 EXPORT_SYMBOL(jbd2_journal_set_triggers); 66 EXPORT_SYMBOL(jbd2_journal_dirty_metadata); 67 EXPORT_SYMBOL(jbd2_journal_forget); 68 EXPORT_SYMBOL(jbd2_journal_flush); 69 EXPORT_SYMBOL(jbd2_journal_revoke); 70 71 EXPORT_SYMBOL(jbd2_journal_init_dev); 72 EXPORT_SYMBOL(jbd2_journal_init_inode); 73 EXPORT_SYMBOL(jbd2_journal_check_used_features); 74 EXPORT_SYMBOL(jbd2_journal_check_available_features); 75 EXPORT_SYMBOL(jbd2_journal_set_features); 76 EXPORT_SYMBOL(jbd2_journal_load); 77 EXPORT_SYMBOL(jbd2_journal_destroy); 78 EXPORT_SYMBOL(jbd2_journal_abort); 79 EXPORT_SYMBOL(jbd2_journal_errno); 80 EXPORT_SYMBOL(jbd2_journal_ack_err); 81 EXPORT_SYMBOL(jbd2_journal_clear_err); 82 EXPORT_SYMBOL(jbd2_log_wait_commit); 83 EXPORT_SYMBOL(jbd2_journal_start_commit); 84 EXPORT_SYMBOL(jbd2_journal_force_commit_nested); 85 EXPORT_SYMBOL(jbd2_journal_wipe); 86 EXPORT_SYMBOL(jbd2_journal_blocks_per_page); 87 EXPORT_SYMBOL(jbd2_journal_invalidate_folio); 88 EXPORT_SYMBOL(jbd2_journal_try_to_free_buffers); 89 EXPORT_SYMBOL(jbd2_journal_force_commit); 90 EXPORT_SYMBOL(jbd2_journal_inode_ranged_write); 91 EXPORT_SYMBOL(jbd2_journal_inode_ranged_wait); 92 EXPORT_SYMBOL(jbd2_journal_finish_inode_data_buffers); 93 EXPORT_SYMBOL(jbd2_journal_init_jbd_inode); 94 EXPORT_SYMBOL(jbd2_journal_release_jbd_inode); 95 EXPORT_SYMBOL(jbd2_journal_begin_ordered_truncate); 96 EXPORT_SYMBOL(jbd2_inode_cache); 97 98 static int jbd2_journal_create_slab(size_t slab_size); 99 100 #ifdef CONFIG_JBD2_DEBUG 101 void __jbd2_debug(int level, const char *file, const char *func, 102 unsigned int line, const char *fmt, ...) 103 { 104 struct va_format vaf; 105 va_list args; 106 107 if (level > jbd2_journal_enable_debug) 108 return; 109 va_start(args, fmt); 110 vaf.fmt = fmt; 111 vaf.va = &args; 112 printk(KERN_DEBUG "%s: (%s, %u): %pV", file, func, line, &vaf); 113 va_end(args); 114 } 115 #endif 116 117 /* Checksumming functions */ 118 static __be32 jbd2_superblock_csum(journal_t *j, journal_superblock_t *sb) 119 { 120 __u32 csum; 121 __be32 old_csum; 122 123 old_csum = sb->s_checksum; 124 sb->s_checksum = 0; 125 csum = jbd2_chksum(j, ~0, (char *)sb, sizeof(journal_superblock_t)); 126 sb->s_checksum = old_csum; 127 128 return cpu_to_be32(csum); 129 } 130 131 /* 132 * Helper function used to manage commit timeouts 133 */ 134 135 static void commit_timeout(struct timer_list *t) 136 { 137 journal_t *journal = from_timer(journal, t, j_commit_timer); 138 139 wake_up_process(journal->j_task); 140 } 141 142 /* 143 * kjournald2: The main thread function used to manage a logging device 144 * journal. 145 * 146 * This kernel thread is responsible for two things: 147 * 148 * 1) COMMIT: Every so often we need to commit the current state of the 149 * filesystem to disk. The journal thread is responsible for writing 150 * all of the metadata buffers to disk. If a fast commit is ongoing 151 * journal thread waits until it's done and then continues from 152 * there on. 153 * 154 * 2) CHECKPOINT: We cannot reuse a used section of the log file until all 155 * of the data in that part of the log has been rewritten elsewhere on 156 * the disk. Flushing these old buffers to reclaim space in the log is 157 * known as checkpointing, and this thread is responsible for that job. 158 */ 159 160 static int kjournald2(void *arg) 161 { 162 journal_t *journal = arg; 163 transaction_t *transaction; 164 165 /* 166 * Set up an interval timer which can be used to trigger a commit wakeup 167 * after the commit interval expires 168 */ 169 timer_setup(&journal->j_commit_timer, commit_timeout, 0); 170 171 set_freezable(); 172 173 /* Record that the journal thread is running */ 174 journal->j_task = current; 175 wake_up(&journal->j_wait_done_commit); 176 177 /* 178 * Make sure that no allocations from this kernel thread will ever 179 * recurse to the fs layer because we are responsible for the 180 * transaction commit and any fs involvement might get stuck waiting for 181 * the trasn. commit. 182 */ 183 memalloc_nofs_save(); 184 185 /* 186 * And now, wait forever for commit wakeup events. 187 */ 188 write_lock(&journal->j_state_lock); 189 190 loop: 191 if (journal->j_flags & JBD2_UNMOUNT) 192 goto end_loop; 193 194 jbd2_debug(1, "commit_sequence=%u, commit_request=%u\n", 195 journal->j_commit_sequence, journal->j_commit_request); 196 197 if (journal->j_commit_sequence != journal->j_commit_request) { 198 jbd2_debug(1, "OK, requests differ\n"); 199 write_unlock(&journal->j_state_lock); 200 del_timer_sync(&journal->j_commit_timer); 201 jbd2_journal_commit_transaction(journal); 202 write_lock(&journal->j_state_lock); 203 goto loop; 204 } 205 206 wake_up(&journal->j_wait_done_commit); 207 if (freezing(current)) { 208 /* 209 * The simpler the better. Flushing journal isn't a 210 * good idea, because that depends on threads that may 211 * be already stopped. 212 */ 213 jbd2_debug(1, "Now suspending kjournald2\n"); 214 write_unlock(&journal->j_state_lock); 215 try_to_freeze(); 216 write_lock(&journal->j_state_lock); 217 } else { 218 /* 219 * We assume on resume that commits are already there, 220 * so we don't sleep 221 */ 222 DEFINE_WAIT(wait); 223 int should_sleep = 1; 224 225 prepare_to_wait(&journal->j_wait_commit, &wait, 226 TASK_INTERRUPTIBLE); 227 if (journal->j_commit_sequence != journal->j_commit_request) 228 should_sleep = 0; 229 transaction = journal->j_running_transaction; 230 if (transaction && time_after_eq(jiffies, 231 transaction->t_expires)) 232 should_sleep = 0; 233 if (journal->j_flags & JBD2_UNMOUNT) 234 should_sleep = 0; 235 if (should_sleep) { 236 write_unlock(&journal->j_state_lock); 237 schedule(); 238 write_lock(&journal->j_state_lock); 239 } 240 finish_wait(&journal->j_wait_commit, &wait); 241 } 242 243 jbd2_debug(1, "kjournald2 wakes\n"); 244 245 /* 246 * Were we woken up by a commit wakeup event? 247 */ 248 transaction = journal->j_running_transaction; 249 if (transaction && time_after_eq(jiffies, transaction->t_expires)) { 250 journal->j_commit_request = transaction->t_tid; 251 jbd2_debug(1, "woke because of timeout\n"); 252 } 253 goto loop; 254 255 end_loop: 256 del_timer_sync(&journal->j_commit_timer); 257 journal->j_task = NULL; 258 wake_up(&journal->j_wait_done_commit); 259 jbd2_debug(1, "Journal thread exiting.\n"); 260 write_unlock(&journal->j_state_lock); 261 return 0; 262 } 263 264 static int jbd2_journal_start_thread(journal_t *journal) 265 { 266 struct task_struct *t; 267 268 t = kthread_run(kjournald2, journal, "jbd2/%s", 269 journal->j_devname); 270 if (IS_ERR(t)) 271 return PTR_ERR(t); 272 273 wait_event(journal->j_wait_done_commit, journal->j_task != NULL); 274 return 0; 275 } 276 277 static void journal_kill_thread(journal_t *journal) 278 { 279 write_lock(&journal->j_state_lock); 280 journal->j_flags |= JBD2_UNMOUNT; 281 282 while (journal->j_task) { 283 write_unlock(&journal->j_state_lock); 284 wake_up(&journal->j_wait_commit); 285 wait_event(journal->j_wait_done_commit, journal->j_task == NULL); 286 write_lock(&journal->j_state_lock); 287 } 288 write_unlock(&journal->j_state_lock); 289 } 290 291 /* 292 * jbd2_journal_write_metadata_buffer: write a metadata buffer to the journal. 293 * 294 * Writes a metadata buffer to a given disk block. The actual IO is not 295 * performed but a new buffer_head is constructed which labels the data 296 * to be written with the correct destination disk block. 297 * 298 * Any magic-number escaping which needs to be done will cause a 299 * copy-out here. If the buffer happens to start with the 300 * JBD2_MAGIC_NUMBER, then we can't write it to the log directly: the 301 * magic number is only written to the log for descripter blocks. In 302 * this case, we copy the data and replace the first word with 0, and we 303 * return a result code which indicates that this buffer needs to be 304 * marked as an escaped buffer in the corresponding log descriptor 305 * block. The missing word can then be restored when the block is read 306 * during recovery. 307 * 308 * If the source buffer has already been modified by a new transaction 309 * since we took the last commit snapshot, we use the frozen copy of 310 * that data for IO. If we end up using the existing buffer_head's data 311 * for the write, then we have to make sure nobody modifies it while the 312 * IO is in progress. do_get_write_access() handles this. 313 * 314 * The function returns a pointer to the buffer_head to be used for IO. 315 * 316 * 317 * Return value: 318 * <0: Error 319 * >=0: Finished OK 320 * 321 * On success: 322 * Bit 0 set == escape performed on the data 323 * Bit 1 set == buffer copy-out performed (kfree the data after IO) 324 */ 325 326 int jbd2_journal_write_metadata_buffer(transaction_t *transaction, 327 struct journal_head *jh_in, 328 struct buffer_head **bh_out, 329 sector_t blocknr) 330 { 331 int need_copy_out = 0; 332 int done_copy_out = 0; 333 int do_escape = 0; 334 char *mapped_data; 335 struct buffer_head *new_bh; 336 struct folio *new_folio; 337 unsigned int new_offset; 338 struct buffer_head *bh_in = jh2bh(jh_in); 339 journal_t *journal = transaction->t_journal; 340 341 /* 342 * The buffer really shouldn't be locked: only the current committing 343 * transaction is allowed to write it, so nobody else is allowed 344 * to do any IO. 345 * 346 * akpm: except if we're journalling data, and write() output is 347 * also part of a shared mapping, and another thread has 348 * decided to launch a writepage() against this buffer. 349 */ 350 J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in)); 351 352 new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL); 353 354 /* keep subsequent assertions sane */ 355 atomic_set(&new_bh->b_count, 1); 356 357 spin_lock(&jh_in->b_state_lock); 358 repeat: 359 /* 360 * If a new transaction has already done a buffer copy-out, then 361 * we use that version of the data for the commit. 362 */ 363 if (jh_in->b_frozen_data) { 364 done_copy_out = 1; 365 new_folio = virt_to_folio(jh_in->b_frozen_data); 366 new_offset = offset_in_folio(new_folio, jh_in->b_frozen_data); 367 } else { 368 new_folio = jh2bh(jh_in)->b_folio; 369 new_offset = offset_in_folio(new_folio, jh2bh(jh_in)->b_data); 370 } 371 372 mapped_data = kmap_local_folio(new_folio, new_offset); 373 /* 374 * Fire data frozen trigger if data already wasn't frozen. Do this 375 * before checking for escaping, as the trigger may modify the magic 376 * offset. If a copy-out happens afterwards, it will have the correct 377 * data in the buffer. 378 */ 379 if (!done_copy_out) 380 jbd2_buffer_frozen_trigger(jh_in, mapped_data, 381 jh_in->b_triggers); 382 383 /* 384 * Check for escaping 385 */ 386 if (*((__be32 *)mapped_data) == cpu_to_be32(JBD2_MAGIC_NUMBER)) { 387 need_copy_out = 1; 388 do_escape = 1; 389 } 390 kunmap_local(mapped_data); 391 392 /* 393 * Do we need to do a data copy? 394 */ 395 if (need_copy_out && !done_copy_out) { 396 char *tmp; 397 398 spin_unlock(&jh_in->b_state_lock); 399 tmp = jbd2_alloc(bh_in->b_size, GFP_NOFS); 400 if (!tmp) { 401 brelse(new_bh); 402 return -ENOMEM; 403 } 404 spin_lock(&jh_in->b_state_lock); 405 if (jh_in->b_frozen_data) { 406 jbd2_free(tmp, bh_in->b_size); 407 goto repeat; 408 } 409 410 jh_in->b_frozen_data = tmp; 411 memcpy_from_folio(tmp, new_folio, new_offset, bh_in->b_size); 412 413 new_folio = virt_to_folio(tmp); 414 new_offset = offset_in_folio(new_folio, tmp); 415 done_copy_out = 1; 416 417 /* 418 * This isn't strictly necessary, as we're using frozen 419 * data for the escaping, but it keeps consistency with 420 * b_frozen_data usage. 421 */ 422 jh_in->b_frozen_triggers = jh_in->b_triggers; 423 } 424 425 /* 426 * Did we need to do an escaping? Now we've done all the 427 * copying, we can finally do so. 428 */ 429 if (do_escape) { 430 mapped_data = kmap_local_folio(new_folio, new_offset); 431 *((unsigned int *)mapped_data) = 0; 432 kunmap_local(mapped_data); 433 } 434 435 folio_set_bh(new_bh, new_folio, new_offset); 436 new_bh->b_size = bh_in->b_size; 437 new_bh->b_bdev = journal->j_dev; 438 new_bh->b_blocknr = blocknr; 439 new_bh->b_private = bh_in; 440 set_buffer_mapped(new_bh); 441 set_buffer_dirty(new_bh); 442 443 *bh_out = new_bh; 444 445 /* 446 * The to-be-written buffer needs to get moved to the io queue, 447 * and the original buffer whose contents we are shadowing or 448 * copying is moved to the transaction's shadow queue. 449 */ 450 JBUFFER_TRACE(jh_in, "file as BJ_Shadow"); 451 spin_lock(&journal->j_list_lock); 452 __jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow); 453 spin_unlock(&journal->j_list_lock); 454 set_buffer_shadow(bh_in); 455 spin_unlock(&jh_in->b_state_lock); 456 457 return do_escape | (done_copy_out << 1); 458 } 459 460 /* 461 * Allocation code for the journal file. Manage the space left in the 462 * journal, so that we can begin checkpointing when appropriate. 463 */ 464 465 /* 466 * Called with j_state_lock locked for writing. 467 * Returns true if a transaction commit was started. 468 */ 469 static int __jbd2_log_start_commit(journal_t *journal, tid_t target) 470 { 471 /* Return if the txn has already requested to be committed */ 472 if (journal->j_commit_request == target) 473 return 0; 474 475 /* 476 * The only transaction we can possibly wait upon is the 477 * currently running transaction (if it exists). Otherwise, 478 * the target tid must be an old one. 479 */ 480 if (journal->j_running_transaction && 481 journal->j_running_transaction->t_tid == target) { 482 /* 483 * We want a new commit: OK, mark the request and wakeup the 484 * commit thread. We do _not_ do the commit ourselves. 485 */ 486 487 journal->j_commit_request = target; 488 jbd2_debug(1, "JBD2: requesting commit %u/%u\n", 489 journal->j_commit_request, 490 journal->j_commit_sequence); 491 journal->j_running_transaction->t_requested = jiffies; 492 wake_up(&journal->j_wait_commit); 493 return 1; 494 } else if (!tid_geq(journal->j_commit_request, target)) 495 /* This should never happen, but if it does, preserve 496 the evidence before kjournald goes into a loop and 497 increments j_commit_sequence beyond all recognition. */ 498 WARN_ONCE(1, "JBD2: bad log_start_commit: %u %u %u %u\n", 499 journal->j_commit_request, 500 journal->j_commit_sequence, 501 target, journal->j_running_transaction ? 502 journal->j_running_transaction->t_tid : 0); 503 return 0; 504 } 505 506 int jbd2_log_start_commit(journal_t *journal, tid_t tid) 507 { 508 int ret; 509 510 write_lock(&journal->j_state_lock); 511 ret = __jbd2_log_start_commit(journal, tid); 512 write_unlock(&journal->j_state_lock); 513 return ret; 514 } 515 516 /* 517 * Force and wait any uncommitted transactions. We can only force the running 518 * transaction if we don't have an active handle, otherwise, we will deadlock. 519 * Returns: <0 in case of error, 520 * 0 if nothing to commit, 521 * 1 if transaction was successfully committed. 522 */ 523 static int __jbd2_journal_force_commit(journal_t *journal) 524 { 525 transaction_t *transaction = NULL; 526 tid_t tid; 527 int need_to_start = 0, ret = 0; 528 529 read_lock(&journal->j_state_lock); 530 if (journal->j_running_transaction && !current->journal_info) { 531 transaction = journal->j_running_transaction; 532 if (!tid_geq(journal->j_commit_request, transaction->t_tid)) 533 need_to_start = 1; 534 } else if (journal->j_committing_transaction) 535 transaction = journal->j_committing_transaction; 536 537 if (!transaction) { 538 /* Nothing to commit */ 539 read_unlock(&journal->j_state_lock); 540 return 0; 541 } 542 tid = transaction->t_tid; 543 read_unlock(&journal->j_state_lock); 544 if (need_to_start) 545 jbd2_log_start_commit(journal, tid); 546 ret = jbd2_log_wait_commit(journal, tid); 547 if (!ret) 548 ret = 1; 549 550 return ret; 551 } 552 553 /** 554 * jbd2_journal_force_commit_nested - Force and wait upon a commit if the 555 * calling process is not within transaction. 556 * 557 * @journal: journal to force 558 * Returns true if progress was made. 559 * 560 * This is used for forcing out undo-protected data which contains 561 * bitmaps, when the fs is running out of space. 562 */ 563 int jbd2_journal_force_commit_nested(journal_t *journal) 564 { 565 int ret; 566 567 ret = __jbd2_journal_force_commit(journal); 568 return ret > 0; 569 } 570 571 /** 572 * jbd2_journal_force_commit() - force any uncommitted transactions 573 * @journal: journal to force 574 * 575 * Caller want unconditional commit. We can only force the running transaction 576 * if we don't have an active handle, otherwise, we will deadlock. 577 */ 578 int jbd2_journal_force_commit(journal_t *journal) 579 { 580 int ret; 581 582 J_ASSERT(!current->journal_info); 583 ret = __jbd2_journal_force_commit(journal); 584 if (ret > 0) 585 ret = 0; 586 return ret; 587 } 588 589 /* 590 * Start a commit of the current running transaction (if any). Returns true 591 * if a transaction is going to be committed (or is currently already 592 * committing), and fills its tid in at *ptid 593 */ 594 int jbd2_journal_start_commit(journal_t *journal, tid_t *ptid) 595 { 596 int ret = 0; 597 598 write_lock(&journal->j_state_lock); 599 if (journal->j_running_transaction) { 600 tid_t tid = journal->j_running_transaction->t_tid; 601 602 __jbd2_log_start_commit(journal, tid); 603 /* There's a running transaction and we've just made sure 604 * it's commit has been scheduled. */ 605 if (ptid) 606 *ptid = tid; 607 ret = 1; 608 } else if (journal->j_committing_transaction) { 609 /* 610 * If commit has been started, then we have to wait for 611 * completion of that transaction. 612 */ 613 if (ptid) 614 *ptid = journal->j_committing_transaction->t_tid; 615 ret = 1; 616 } 617 write_unlock(&journal->j_state_lock); 618 return ret; 619 } 620 621 /* 622 * Return 1 if a given transaction has not yet sent barrier request 623 * connected with a transaction commit. If 0 is returned, transaction 624 * may or may not have sent the barrier. Used to avoid sending barrier 625 * twice in common cases. 626 */ 627 int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid) 628 { 629 int ret = 0; 630 transaction_t *commit_trans; 631 632 if (!(journal->j_flags & JBD2_BARRIER)) 633 return 0; 634 read_lock(&journal->j_state_lock); 635 /* Transaction already committed? */ 636 if (tid_geq(journal->j_commit_sequence, tid)) 637 goto out; 638 commit_trans = journal->j_committing_transaction; 639 if (!commit_trans || commit_trans->t_tid != tid) { 640 ret = 1; 641 goto out; 642 } 643 /* 644 * Transaction is being committed and we already proceeded to 645 * submitting a flush to fs partition? 646 */ 647 if (journal->j_fs_dev != journal->j_dev) { 648 if (!commit_trans->t_need_data_flush || 649 commit_trans->t_state >= T_COMMIT_DFLUSH) 650 goto out; 651 } else { 652 if (commit_trans->t_state >= T_COMMIT_JFLUSH) 653 goto out; 654 } 655 ret = 1; 656 out: 657 read_unlock(&journal->j_state_lock); 658 return ret; 659 } 660 EXPORT_SYMBOL(jbd2_trans_will_send_data_barrier); 661 662 /* 663 * Wait for a specified commit to complete. 664 * The caller may not hold the journal lock. 665 */ 666 int jbd2_log_wait_commit(journal_t *journal, tid_t tid) 667 { 668 int err = 0; 669 670 read_lock(&journal->j_state_lock); 671 #ifdef CONFIG_PROVE_LOCKING 672 /* 673 * Some callers make sure transaction is already committing and in that 674 * case we cannot block on open handles anymore. So don't warn in that 675 * case. 676 */ 677 if (tid_gt(tid, journal->j_commit_sequence) && 678 (!journal->j_committing_transaction || 679 journal->j_committing_transaction->t_tid != tid)) { 680 read_unlock(&journal->j_state_lock); 681 jbd2_might_wait_for_commit(journal); 682 read_lock(&journal->j_state_lock); 683 } 684 #endif 685 #ifdef CONFIG_JBD2_DEBUG 686 if (!tid_geq(journal->j_commit_request, tid)) { 687 printk(KERN_ERR 688 "%s: error: j_commit_request=%u, tid=%u\n", 689 __func__, journal->j_commit_request, tid); 690 } 691 #endif 692 while (tid_gt(tid, journal->j_commit_sequence)) { 693 jbd2_debug(1, "JBD2: want %u, j_commit_sequence=%u\n", 694 tid, journal->j_commit_sequence); 695 read_unlock(&journal->j_state_lock); 696 wake_up(&journal->j_wait_commit); 697 wait_event(journal->j_wait_done_commit, 698 !tid_gt(tid, journal->j_commit_sequence)); 699 read_lock(&journal->j_state_lock); 700 } 701 read_unlock(&journal->j_state_lock); 702 703 if (unlikely(is_journal_aborted(journal))) 704 err = -EIO; 705 return err; 706 } 707 708 /* 709 * Start a fast commit. If there's an ongoing fast or full commit wait for 710 * it to complete. Returns 0 if a new fast commit was started. Returns -EALREADY 711 * if a fast commit is not needed, either because there's an already a commit 712 * going on or this tid has already been committed. Returns -EINVAL if no jbd2 713 * commit has yet been performed. 714 */ 715 int jbd2_fc_begin_commit(journal_t *journal, tid_t tid) 716 { 717 if (unlikely(is_journal_aborted(journal))) 718 return -EIO; 719 /* 720 * Fast commits only allowed if at least one full commit has 721 * been processed. 722 */ 723 if (!journal->j_stats.ts_tid) 724 return -EINVAL; 725 726 write_lock(&journal->j_state_lock); 727 if (tid <= journal->j_commit_sequence) { 728 write_unlock(&journal->j_state_lock); 729 return -EALREADY; 730 } 731 732 if (journal->j_flags & JBD2_FULL_COMMIT_ONGOING || 733 (journal->j_flags & JBD2_FAST_COMMIT_ONGOING)) { 734 DEFINE_WAIT(wait); 735 736 prepare_to_wait(&journal->j_fc_wait, &wait, 737 TASK_UNINTERRUPTIBLE); 738 write_unlock(&journal->j_state_lock); 739 schedule(); 740 finish_wait(&journal->j_fc_wait, &wait); 741 return -EALREADY; 742 } 743 journal->j_flags |= JBD2_FAST_COMMIT_ONGOING; 744 write_unlock(&journal->j_state_lock); 745 jbd2_journal_lock_updates(journal); 746 747 return 0; 748 } 749 EXPORT_SYMBOL(jbd2_fc_begin_commit); 750 751 /* 752 * Stop a fast commit. If fallback is set, this function starts commit of 753 * TID tid before any other fast commit can start. 754 */ 755 static int __jbd2_fc_end_commit(journal_t *journal, tid_t tid, bool fallback) 756 { 757 jbd2_journal_unlock_updates(journal); 758 if (journal->j_fc_cleanup_callback) 759 journal->j_fc_cleanup_callback(journal, 0, tid); 760 write_lock(&journal->j_state_lock); 761 journal->j_flags &= ~JBD2_FAST_COMMIT_ONGOING; 762 if (fallback) 763 journal->j_flags |= JBD2_FULL_COMMIT_ONGOING; 764 write_unlock(&journal->j_state_lock); 765 wake_up(&journal->j_fc_wait); 766 if (fallback) 767 return jbd2_complete_transaction(journal, tid); 768 return 0; 769 } 770 771 int jbd2_fc_end_commit(journal_t *journal) 772 { 773 return __jbd2_fc_end_commit(journal, 0, false); 774 } 775 EXPORT_SYMBOL(jbd2_fc_end_commit); 776 777 int jbd2_fc_end_commit_fallback(journal_t *journal) 778 { 779 tid_t tid; 780 781 read_lock(&journal->j_state_lock); 782 tid = journal->j_running_transaction ? 783 journal->j_running_transaction->t_tid : 0; 784 read_unlock(&journal->j_state_lock); 785 return __jbd2_fc_end_commit(journal, tid, true); 786 } 787 EXPORT_SYMBOL(jbd2_fc_end_commit_fallback); 788 789 /* Return 1 when transaction with given tid has already committed. */ 790 int jbd2_transaction_committed(journal_t *journal, tid_t tid) 791 { 792 int ret = 1; 793 794 read_lock(&journal->j_state_lock); 795 if (journal->j_running_transaction && 796 journal->j_running_transaction->t_tid == tid) 797 ret = 0; 798 if (journal->j_committing_transaction && 799 journal->j_committing_transaction->t_tid == tid) 800 ret = 0; 801 read_unlock(&journal->j_state_lock); 802 return ret; 803 } 804 EXPORT_SYMBOL(jbd2_transaction_committed); 805 806 /* 807 * When this function returns the transaction corresponding to tid 808 * will be completed. If the transaction has currently running, start 809 * committing that transaction before waiting for it to complete. If 810 * the transaction id is stale, it is by definition already completed, 811 * so just return SUCCESS. 812 */ 813 int jbd2_complete_transaction(journal_t *journal, tid_t tid) 814 { 815 int need_to_wait = 1; 816 817 read_lock(&journal->j_state_lock); 818 if (journal->j_running_transaction && 819 journal->j_running_transaction->t_tid == tid) { 820 if (journal->j_commit_request != tid) { 821 /* transaction not yet started, so request it */ 822 read_unlock(&journal->j_state_lock); 823 jbd2_log_start_commit(journal, tid); 824 goto wait_commit; 825 } 826 } else if (!(journal->j_committing_transaction && 827 journal->j_committing_transaction->t_tid == tid)) 828 need_to_wait = 0; 829 read_unlock(&journal->j_state_lock); 830 if (!need_to_wait) 831 return 0; 832 wait_commit: 833 return jbd2_log_wait_commit(journal, tid); 834 } 835 EXPORT_SYMBOL(jbd2_complete_transaction); 836 837 /* 838 * Log buffer allocation routines: 839 */ 840 841 int jbd2_journal_next_log_block(journal_t *journal, unsigned long long *retp) 842 { 843 unsigned long blocknr; 844 845 write_lock(&journal->j_state_lock); 846 J_ASSERT(journal->j_free > 1); 847 848 blocknr = journal->j_head; 849 journal->j_head++; 850 journal->j_free--; 851 if (journal->j_head == journal->j_last) 852 journal->j_head = journal->j_first; 853 write_unlock(&journal->j_state_lock); 854 return jbd2_journal_bmap(journal, blocknr, retp); 855 } 856 857 /* Map one fast commit buffer for use by the file system */ 858 int jbd2_fc_get_buf(journal_t *journal, struct buffer_head **bh_out) 859 { 860 unsigned long long pblock; 861 unsigned long blocknr; 862 int ret = 0; 863 struct buffer_head *bh; 864 int fc_off; 865 866 *bh_out = NULL; 867 868 if (journal->j_fc_off + journal->j_fc_first < journal->j_fc_last) { 869 fc_off = journal->j_fc_off; 870 blocknr = journal->j_fc_first + fc_off; 871 journal->j_fc_off++; 872 } else { 873 ret = -EINVAL; 874 } 875 876 if (ret) 877 return ret; 878 879 ret = jbd2_journal_bmap(journal, blocknr, &pblock); 880 if (ret) 881 return ret; 882 883 bh = __getblk(journal->j_dev, pblock, journal->j_blocksize); 884 if (!bh) 885 return -ENOMEM; 886 887 888 journal->j_fc_wbuf[fc_off] = bh; 889 890 *bh_out = bh; 891 892 return 0; 893 } 894 EXPORT_SYMBOL(jbd2_fc_get_buf); 895 896 /* 897 * Wait on fast commit buffers that were allocated by jbd2_fc_get_buf 898 * for completion. 899 */ 900 int jbd2_fc_wait_bufs(journal_t *journal, int num_blks) 901 { 902 struct buffer_head *bh; 903 int i, j_fc_off; 904 905 j_fc_off = journal->j_fc_off; 906 907 /* 908 * Wait in reverse order to minimize chances of us being woken up before 909 * all IOs have completed 910 */ 911 for (i = j_fc_off - 1; i >= j_fc_off - num_blks; i--) { 912 bh = journal->j_fc_wbuf[i]; 913 wait_on_buffer(bh); 914 /* 915 * Update j_fc_off so jbd2_fc_release_bufs can release remain 916 * buffer head. 917 */ 918 if (unlikely(!buffer_uptodate(bh))) { 919 journal->j_fc_off = i + 1; 920 return -EIO; 921 } 922 put_bh(bh); 923 journal->j_fc_wbuf[i] = NULL; 924 } 925 926 return 0; 927 } 928 EXPORT_SYMBOL(jbd2_fc_wait_bufs); 929 930 int jbd2_fc_release_bufs(journal_t *journal) 931 { 932 struct buffer_head *bh; 933 int i, j_fc_off; 934 935 j_fc_off = journal->j_fc_off; 936 937 for (i = j_fc_off - 1; i >= 0; i--) { 938 bh = journal->j_fc_wbuf[i]; 939 if (!bh) 940 break; 941 put_bh(bh); 942 journal->j_fc_wbuf[i] = NULL; 943 } 944 945 return 0; 946 } 947 EXPORT_SYMBOL(jbd2_fc_release_bufs); 948 949 /* 950 * Conversion of logical to physical block numbers for the journal 951 * 952 * On external journals the journal blocks are identity-mapped, so 953 * this is a no-op. If needed, we can use j_blk_offset - everything is 954 * ready. 955 */ 956 int jbd2_journal_bmap(journal_t *journal, unsigned long blocknr, 957 unsigned long long *retp) 958 { 959 int err = 0; 960 unsigned long long ret; 961 sector_t block = blocknr; 962 963 if (journal->j_bmap) { 964 err = journal->j_bmap(journal, &block); 965 if (err == 0) 966 *retp = block; 967 } else if (journal->j_inode) { 968 ret = bmap(journal->j_inode, &block); 969 970 if (ret || !block) { 971 printk(KERN_ALERT "%s: journal block not found " 972 "at offset %lu on %s\n", 973 __func__, blocknr, journal->j_devname); 974 err = -EIO; 975 jbd2_journal_abort(journal, err); 976 } else { 977 *retp = block; 978 } 979 980 } else { 981 *retp = blocknr; /* +journal->j_blk_offset */ 982 } 983 return err; 984 } 985 986 /* 987 * We play buffer_head aliasing tricks to write data/metadata blocks to 988 * the journal without copying their contents, but for journal 989 * descriptor blocks we do need to generate bona fide buffers. 990 * 991 * After the caller of jbd2_journal_get_descriptor_buffer() has finished modifying 992 * the buffer's contents they really should run flush_dcache_page(bh->b_page). 993 * But we don't bother doing that, so there will be coherency problems with 994 * mmaps of blockdevs which hold live JBD-controlled filesystems. 995 */ 996 struct buffer_head * 997 jbd2_journal_get_descriptor_buffer(transaction_t *transaction, int type) 998 { 999 journal_t *journal = transaction->t_journal; 1000 struct buffer_head *bh; 1001 unsigned long long blocknr; 1002 journal_header_t *header; 1003 int err; 1004 1005 err = jbd2_journal_next_log_block(journal, &blocknr); 1006 1007 if (err) 1008 return NULL; 1009 1010 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); 1011 if (!bh) 1012 return NULL; 1013 atomic_dec(&transaction->t_outstanding_credits); 1014 lock_buffer(bh); 1015 memset(bh->b_data, 0, journal->j_blocksize); 1016 header = (journal_header_t *)bh->b_data; 1017 header->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER); 1018 header->h_blocktype = cpu_to_be32(type); 1019 header->h_sequence = cpu_to_be32(transaction->t_tid); 1020 set_buffer_uptodate(bh); 1021 unlock_buffer(bh); 1022 BUFFER_TRACE(bh, "return this buffer"); 1023 return bh; 1024 } 1025 1026 void jbd2_descriptor_block_csum_set(journal_t *j, struct buffer_head *bh) 1027 { 1028 struct jbd2_journal_block_tail *tail; 1029 __u32 csum; 1030 1031 if (!jbd2_journal_has_csum_v2or3(j)) 1032 return; 1033 1034 tail = (struct jbd2_journal_block_tail *)(bh->b_data + j->j_blocksize - 1035 sizeof(struct jbd2_journal_block_tail)); 1036 tail->t_checksum = 0; 1037 csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize); 1038 tail->t_checksum = cpu_to_be32(csum); 1039 } 1040 1041 /* 1042 * Return tid of the oldest transaction in the journal and block in the journal 1043 * where the transaction starts. 1044 * 1045 * If the journal is now empty, return which will be the next transaction ID 1046 * we will write and where will that transaction start. 1047 * 1048 * The return value is 0 if journal tail cannot be pushed any further, 1 if 1049 * it can. 1050 */ 1051 int jbd2_journal_get_log_tail(journal_t *journal, tid_t *tid, 1052 unsigned long *block) 1053 { 1054 transaction_t *transaction; 1055 int ret; 1056 1057 read_lock(&journal->j_state_lock); 1058 spin_lock(&journal->j_list_lock); 1059 transaction = journal->j_checkpoint_transactions; 1060 if (transaction) { 1061 *tid = transaction->t_tid; 1062 *block = transaction->t_log_start; 1063 } else if ((transaction = journal->j_committing_transaction) != NULL) { 1064 *tid = transaction->t_tid; 1065 *block = transaction->t_log_start; 1066 } else if ((transaction = journal->j_running_transaction) != NULL) { 1067 *tid = transaction->t_tid; 1068 *block = journal->j_head; 1069 } else { 1070 *tid = journal->j_transaction_sequence; 1071 *block = journal->j_head; 1072 } 1073 ret = tid_gt(*tid, journal->j_tail_sequence); 1074 spin_unlock(&journal->j_list_lock); 1075 read_unlock(&journal->j_state_lock); 1076 1077 return ret; 1078 } 1079 1080 /* 1081 * Update information in journal structure and in on disk journal superblock 1082 * about log tail. This function does not check whether information passed in 1083 * really pushes log tail further. It's responsibility of the caller to make 1084 * sure provided log tail information is valid (e.g. by holding 1085 * j_checkpoint_mutex all the time between computing log tail and calling this 1086 * function as is the case with jbd2_cleanup_journal_tail()). 1087 * 1088 * Requires j_checkpoint_mutex 1089 */ 1090 int __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block) 1091 { 1092 unsigned long freed; 1093 int ret; 1094 1095 BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex)); 1096 1097 /* 1098 * We cannot afford for write to remain in drive's caches since as 1099 * soon as we update j_tail, next transaction can start reusing journal 1100 * space and if we lose sb update during power failure we'd replay 1101 * old transaction with possibly newly overwritten data. 1102 */ 1103 ret = jbd2_journal_update_sb_log_tail(journal, tid, block, REQ_FUA); 1104 if (ret) 1105 goto out; 1106 1107 write_lock(&journal->j_state_lock); 1108 freed = block - journal->j_tail; 1109 if (block < journal->j_tail) 1110 freed += journal->j_last - journal->j_first; 1111 1112 trace_jbd2_update_log_tail(journal, tid, block, freed); 1113 jbd2_debug(1, 1114 "Cleaning journal tail from %u to %u (offset %lu), " 1115 "freeing %lu\n", 1116 journal->j_tail_sequence, tid, block, freed); 1117 1118 journal->j_free += freed; 1119 journal->j_tail_sequence = tid; 1120 journal->j_tail = block; 1121 write_unlock(&journal->j_state_lock); 1122 1123 out: 1124 return ret; 1125 } 1126 1127 /* 1128 * This is a variation of __jbd2_update_log_tail which checks for validity of 1129 * provided log tail and locks j_checkpoint_mutex. So it is safe against races 1130 * with other threads updating log tail. 1131 */ 1132 void jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block) 1133 { 1134 mutex_lock_io(&journal->j_checkpoint_mutex); 1135 if (tid_gt(tid, journal->j_tail_sequence)) 1136 __jbd2_update_log_tail(journal, tid, block); 1137 mutex_unlock(&journal->j_checkpoint_mutex); 1138 } 1139 1140 struct jbd2_stats_proc_session { 1141 journal_t *journal; 1142 struct transaction_stats_s *stats; 1143 int start; 1144 int max; 1145 }; 1146 1147 static void *jbd2_seq_info_start(struct seq_file *seq, loff_t *pos) 1148 { 1149 return *pos ? NULL : SEQ_START_TOKEN; 1150 } 1151 1152 static void *jbd2_seq_info_next(struct seq_file *seq, void *v, loff_t *pos) 1153 { 1154 (*pos)++; 1155 return NULL; 1156 } 1157 1158 static int jbd2_seq_info_show(struct seq_file *seq, void *v) 1159 { 1160 struct jbd2_stats_proc_session *s = seq->private; 1161 1162 if (v != SEQ_START_TOKEN) 1163 return 0; 1164 seq_printf(seq, "%lu transactions (%lu requested), " 1165 "each up to %u blocks\n", 1166 s->stats->ts_tid, s->stats->ts_requested, 1167 s->journal->j_max_transaction_buffers); 1168 if (s->stats->ts_tid == 0) 1169 return 0; 1170 seq_printf(seq, "average: \n %ums waiting for transaction\n", 1171 jiffies_to_msecs(s->stats->run.rs_wait / s->stats->ts_tid)); 1172 seq_printf(seq, " %ums request delay\n", 1173 (s->stats->ts_requested == 0) ? 0 : 1174 jiffies_to_msecs(s->stats->run.rs_request_delay / 1175 s->stats->ts_requested)); 1176 seq_printf(seq, " %ums running transaction\n", 1177 jiffies_to_msecs(s->stats->run.rs_running / s->stats->ts_tid)); 1178 seq_printf(seq, " %ums transaction was being locked\n", 1179 jiffies_to_msecs(s->stats->run.rs_locked / s->stats->ts_tid)); 1180 seq_printf(seq, " %ums flushing data (in ordered mode)\n", 1181 jiffies_to_msecs(s->stats->run.rs_flushing / s->stats->ts_tid)); 1182 seq_printf(seq, " %ums logging transaction\n", 1183 jiffies_to_msecs(s->stats->run.rs_logging / s->stats->ts_tid)); 1184 seq_printf(seq, " %lluus average transaction commit time\n", 1185 div_u64(s->journal->j_average_commit_time, 1000)); 1186 seq_printf(seq, " %lu handles per transaction\n", 1187 s->stats->run.rs_handle_count / s->stats->ts_tid); 1188 seq_printf(seq, " %lu blocks per transaction\n", 1189 s->stats->run.rs_blocks / s->stats->ts_tid); 1190 seq_printf(seq, " %lu logged blocks per transaction\n", 1191 s->stats->run.rs_blocks_logged / s->stats->ts_tid); 1192 return 0; 1193 } 1194 1195 static void jbd2_seq_info_stop(struct seq_file *seq, void *v) 1196 { 1197 } 1198 1199 static const struct seq_operations jbd2_seq_info_ops = { 1200 .start = jbd2_seq_info_start, 1201 .next = jbd2_seq_info_next, 1202 .stop = jbd2_seq_info_stop, 1203 .show = jbd2_seq_info_show, 1204 }; 1205 1206 static int jbd2_seq_info_open(struct inode *inode, struct file *file) 1207 { 1208 journal_t *journal = pde_data(inode); 1209 struct jbd2_stats_proc_session *s; 1210 int rc, size; 1211 1212 s = kmalloc(sizeof(*s), GFP_KERNEL); 1213 if (s == NULL) 1214 return -ENOMEM; 1215 size = sizeof(struct transaction_stats_s); 1216 s->stats = kmalloc(size, GFP_KERNEL); 1217 if (s->stats == NULL) { 1218 kfree(s); 1219 return -ENOMEM; 1220 } 1221 spin_lock(&journal->j_history_lock); 1222 memcpy(s->stats, &journal->j_stats, size); 1223 s->journal = journal; 1224 spin_unlock(&journal->j_history_lock); 1225 1226 rc = seq_open(file, &jbd2_seq_info_ops); 1227 if (rc == 0) { 1228 struct seq_file *m = file->private_data; 1229 m->private = s; 1230 } else { 1231 kfree(s->stats); 1232 kfree(s); 1233 } 1234 return rc; 1235 1236 } 1237 1238 static int jbd2_seq_info_release(struct inode *inode, struct file *file) 1239 { 1240 struct seq_file *seq = file->private_data; 1241 struct jbd2_stats_proc_session *s = seq->private; 1242 kfree(s->stats); 1243 kfree(s); 1244 return seq_release(inode, file); 1245 } 1246 1247 static const struct proc_ops jbd2_info_proc_ops = { 1248 .proc_open = jbd2_seq_info_open, 1249 .proc_read = seq_read, 1250 .proc_lseek = seq_lseek, 1251 .proc_release = jbd2_seq_info_release, 1252 }; 1253 1254 static struct proc_dir_entry *proc_jbd2_stats; 1255 1256 static void jbd2_stats_proc_init(journal_t *journal) 1257 { 1258 journal->j_proc_entry = proc_mkdir(journal->j_devname, proc_jbd2_stats); 1259 if (journal->j_proc_entry) { 1260 proc_create_data("info", S_IRUGO, journal->j_proc_entry, 1261 &jbd2_info_proc_ops, journal); 1262 } 1263 } 1264 1265 static void jbd2_stats_proc_exit(journal_t *journal) 1266 { 1267 remove_proc_entry("info", journal->j_proc_entry); 1268 remove_proc_entry(journal->j_devname, proc_jbd2_stats); 1269 } 1270 1271 /* Minimum size of descriptor tag */ 1272 static int jbd2_min_tag_size(void) 1273 { 1274 /* 1275 * Tag with 32-bit block numbers does not use last four bytes of the 1276 * structure 1277 */ 1278 return sizeof(journal_block_tag_t) - 4; 1279 } 1280 1281 /** 1282 * jbd2_journal_shrink_scan() 1283 * @shrink: shrinker to work on 1284 * @sc: reclaim request to process 1285 * 1286 * Scan the checkpointed buffer on the checkpoint list and release the 1287 * journal_head. 1288 */ 1289 static unsigned long jbd2_journal_shrink_scan(struct shrinker *shrink, 1290 struct shrink_control *sc) 1291 { 1292 journal_t *journal = shrink->private_data; 1293 unsigned long nr_to_scan = sc->nr_to_scan; 1294 unsigned long nr_shrunk; 1295 unsigned long count; 1296 1297 count = percpu_counter_read_positive(&journal->j_checkpoint_jh_count); 1298 trace_jbd2_shrink_scan_enter(journal, sc->nr_to_scan, count); 1299 1300 nr_shrunk = jbd2_journal_shrink_checkpoint_list(journal, &nr_to_scan); 1301 1302 count = percpu_counter_read_positive(&journal->j_checkpoint_jh_count); 1303 trace_jbd2_shrink_scan_exit(journal, nr_to_scan, nr_shrunk, count); 1304 1305 return nr_shrunk; 1306 } 1307 1308 /** 1309 * jbd2_journal_shrink_count() 1310 * @shrink: shrinker to work on 1311 * @sc: reclaim request to process 1312 * 1313 * Count the number of checkpoint buffers on the checkpoint list. 1314 */ 1315 static unsigned long jbd2_journal_shrink_count(struct shrinker *shrink, 1316 struct shrink_control *sc) 1317 { 1318 journal_t *journal = shrink->private_data; 1319 unsigned long count; 1320 1321 count = percpu_counter_read_positive(&journal->j_checkpoint_jh_count); 1322 trace_jbd2_shrink_count(journal, sc->nr_to_scan, count); 1323 1324 return count; 1325 } 1326 1327 /* 1328 * If the journal init or create aborts, we need to mark the journal 1329 * superblock as being NULL to prevent the journal destroy from writing 1330 * back a bogus superblock. 1331 */ 1332 static void journal_fail_superblock(journal_t *journal) 1333 { 1334 struct buffer_head *bh = journal->j_sb_buffer; 1335 brelse(bh); 1336 journal->j_sb_buffer = NULL; 1337 } 1338 1339 /* 1340 * Check the superblock for a given journal, performing initial 1341 * validation of the format. 1342 */ 1343 static int journal_check_superblock(journal_t *journal) 1344 { 1345 journal_superblock_t *sb = journal->j_superblock; 1346 int num_fc_blks; 1347 int err = -EINVAL; 1348 1349 if (sb->s_header.h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER) || 1350 sb->s_blocksize != cpu_to_be32(journal->j_blocksize)) { 1351 printk(KERN_WARNING "JBD2: no valid journal superblock found\n"); 1352 return err; 1353 } 1354 1355 if (be32_to_cpu(sb->s_header.h_blocktype) != JBD2_SUPERBLOCK_V1 && 1356 be32_to_cpu(sb->s_header.h_blocktype) != JBD2_SUPERBLOCK_V2) { 1357 printk(KERN_WARNING "JBD2: unrecognised superblock format ID\n"); 1358 return err; 1359 } 1360 1361 if (be32_to_cpu(sb->s_maxlen) > journal->j_total_len) { 1362 printk(KERN_WARNING "JBD2: journal file too short\n"); 1363 return err; 1364 } 1365 1366 if (be32_to_cpu(sb->s_first) == 0 || 1367 be32_to_cpu(sb->s_first) >= journal->j_total_len) { 1368 printk(KERN_WARNING 1369 "JBD2: Invalid start block of journal: %u\n", 1370 be32_to_cpu(sb->s_first)); 1371 return err; 1372 } 1373 1374 /* 1375 * If this is a V2 superblock, then we have to check the 1376 * features flags on it. 1377 */ 1378 if (!jbd2_format_support_feature(journal)) 1379 return 0; 1380 1381 if ((sb->s_feature_ro_compat & 1382 ~cpu_to_be32(JBD2_KNOWN_ROCOMPAT_FEATURES)) || 1383 (sb->s_feature_incompat & 1384 ~cpu_to_be32(JBD2_KNOWN_INCOMPAT_FEATURES))) { 1385 printk(KERN_WARNING "JBD2: Unrecognised features on journal\n"); 1386 return err; 1387 } 1388 1389 num_fc_blks = jbd2_has_feature_fast_commit(journal) ? 1390 jbd2_journal_get_num_fc_blks(sb) : 0; 1391 if (be32_to_cpu(sb->s_maxlen) < JBD2_MIN_JOURNAL_BLOCKS || 1392 be32_to_cpu(sb->s_maxlen) - JBD2_MIN_JOURNAL_BLOCKS < num_fc_blks) { 1393 printk(KERN_ERR "JBD2: journal file too short %u,%d\n", 1394 be32_to_cpu(sb->s_maxlen), num_fc_blks); 1395 return err; 1396 } 1397 1398 if (jbd2_has_feature_csum2(journal) && 1399 jbd2_has_feature_csum3(journal)) { 1400 /* Can't have checksum v2 and v3 at the same time! */ 1401 printk(KERN_ERR "JBD2: Can't enable checksumming v2 and v3 " 1402 "at the same time!\n"); 1403 return err; 1404 } 1405 1406 if (jbd2_journal_has_csum_v2or3_feature(journal) && 1407 jbd2_has_feature_checksum(journal)) { 1408 /* Can't have checksum v1 and v2 on at the same time! */ 1409 printk(KERN_ERR "JBD2: Can't enable checksumming v1 and v2/3 " 1410 "at the same time!\n"); 1411 return err; 1412 } 1413 1414 /* Load the checksum driver */ 1415 if (jbd2_journal_has_csum_v2or3_feature(journal)) { 1416 if (sb->s_checksum_type != JBD2_CRC32C_CHKSUM) { 1417 printk(KERN_ERR "JBD2: Unknown checksum type\n"); 1418 return err; 1419 } 1420 1421 journal->j_chksum_driver = crypto_alloc_shash("crc32c", 0, 0); 1422 if (IS_ERR(journal->j_chksum_driver)) { 1423 printk(KERN_ERR "JBD2: Cannot load crc32c driver.\n"); 1424 err = PTR_ERR(journal->j_chksum_driver); 1425 journal->j_chksum_driver = NULL; 1426 return err; 1427 } 1428 /* Check superblock checksum */ 1429 if (sb->s_checksum != jbd2_superblock_csum(journal, sb)) { 1430 printk(KERN_ERR "JBD2: journal checksum error\n"); 1431 err = -EFSBADCRC; 1432 return err; 1433 } 1434 } 1435 1436 return 0; 1437 } 1438 1439 static int journal_revoke_records_per_block(journal_t *journal) 1440 { 1441 int record_size; 1442 int space = journal->j_blocksize - sizeof(jbd2_journal_revoke_header_t); 1443 1444 if (jbd2_has_feature_64bit(journal)) 1445 record_size = 8; 1446 else 1447 record_size = 4; 1448 1449 if (jbd2_journal_has_csum_v2or3(journal)) 1450 space -= sizeof(struct jbd2_journal_block_tail); 1451 return space / record_size; 1452 } 1453 1454 /* 1455 * Load the on-disk journal superblock and read the key fields into the 1456 * journal_t. 1457 */ 1458 static int journal_load_superblock(journal_t *journal) 1459 { 1460 int err; 1461 struct buffer_head *bh; 1462 journal_superblock_t *sb; 1463 1464 bh = getblk_unmovable(journal->j_dev, journal->j_blk_offset, 1465 journal->j_blocksize); 1466 if (bh) 1467 err = bh_read(bh, 0); 1468 if (!bh || err < 0) { 1469 pr_err("%s: Cannot read journal superblock\n", __func__); 1470 brelse(bh); 1471 return -EIO; 1472 } 1473 1474 journal->j_sb_buffer = bh; 1475 sb = (journal_superblock_t *)bh->b_data; 1476 journal->j_superblock = sb; 1477 err = journal_check_superblock(journal); 1478 if (err) { 1479 journal_fail_superblock(journal); 1480 return err; 1481 } 1482 1483 journal->j_tail_sequence = be32_to_cpu(sb->s_sequence); 1484 journal->j_tail = be32_to_cpu(sb->s_start); 1485 journal->j_first = be32_to_cpu(sb->s_first); 1486 journal->j_errno = be32_to_cpu(sb->s_errno); 1487 journal->j_last = be32_to_cpu(sb->s_maxlen); 1488 1489 if (be32_to_cpu(sb->s_maxlen) < journal->j_total_len) 1490 journal->j_total_len = be32_to_cpu(sb->s_maxlen); 1491 /* Precompute checksum seed for all metadata */ 1492 if (jbd2_journal_has_csum_v2or3(journal)) 1493 journal->j_csum_seed = jbd2_chksum(journal, ~0, sb->s_uuid, 1494 sizeof(sb->s_uuid)); 1495 journal->j_revoke_records_per_block = 1496 journal_revoke_records_per_block(journal); 1497 1498 if (jbd2_has_feature_fast_commit(journal)) { 1499 journal->j_fc_last = be32_to_cpu(sb->s_maxlen); 1500 journal->j_last = journal->j_fc_last - 1501 jbd2_journal_get_num_fc_blks(sb); 1502 journal->j_fc_first = journal->j_last + 1; 1503 journal->j_fc_off = 0; 1504 } 1505 1506 return 0; 1507 } 1508 1509 1510 /* 1511 * Management for journal control blocks: functions to create and 1512 * destroy journal_t structures, and to initialise and read existing 1513 * journal blocks from disk. */ 1514 1515 /* First: create and setup a journal_t object in memory. We initialise 1516 * very few fields yet: that has to wait until we have created the 1517 * journal structures from from scratch, or loaded them from disk. */ 1518 1519 static journal_t *journal_init_common(struct block_device *bdev, 1520 struct block_device *fs_dev, 1521 unsigned long long start, int len, int blocksize) 1522 { 1523 static struct lock_class_key jbd2_trans_commit_key; 1524 journal_t *journal; 1525 int err; 1526 int n; 1527 1528 journal = kzalloc(sizeof(*journal), GFP_KERNEL); 1529 if (!journal) 1530 return ERR_PTR(-ENOMEM); 1531 1532 journal->j_blocksize = blocksize; 1533 journal->j_dev = bdev; 1534 journal->j_fs_dev = fs_dev; 1535 journal->j_blk_offset = start; 1536 journal->j_total_len = len; 1537 jbd2_init_fs_dev_write_error(journal); 1538 1539 err = journal_load_superblock(journal); 1540 if (err) 1541 goto err_cleanup; 1542 1543 init_waitqueue_head(&journal->j_wait_transaction_locked); 1544 init_waitqueue_head(&journal->j_wait_done_commit); 1545 init_waitqueue_head(&journal->j_wait_commit); 1546 init_waitqueue_head(&journal->j_wait_updates); 1547 init_waitqueue_head(&journal->j_wait_reserved); 1548 init_waitqueue_head(&journal->j_fc_wait); 1549 mutex_init(&journal->j_abort_mutex); 1550 mutex_init(&journal->j_barrier); 1551 mutex_init(&journal->j_checkpoint_mutex); 1552 spin_lock_init(&journal->j_revoke_lock); 1553 spin_lock_init(&journal->j_list_lock); 1554 spin_lock_init(&journal->j_history_lock); 1555 rwlock_init(&journal->j_state_lock); 1556 1557 journal->j_commit_interval = (HZ * JBD2_DEFAULT_MAX_COMMIT_AGE); 1558 journal->j_min_batch_time = 0; 1559 journal->j_max_batch_time = 15000; /* 15ms */ 1560 atomic_set(&journal->j_reserved_credits, 0); 1561 lockdep_init_map(&journal->j_trans_commit_map, "jbd2_handle", 1562 &jbd2_trans_commit_key, 0); 1563 1564 /* The journal is marked for error until we succeed with recovery! */ 1565 journal->j_flags = JBD2_ABORT; 1566 1567 /* Set up a default-sized revoke table for the new mount. */ 1568 err = jbd2_journal_init_revoke(journal, JOURNAL_REVOKE_DEFAULT_HASH); 1569 if (err) 1570 goto err_cleanup; 1571 1572 /* 1573 * journal descriptor can store up to n blocks, we need enough 1574 * buffers to write out full descriptor block. 1575 */ 1576 err = -ENOMEM; 1577 n = journal->j_blocksize / jbd2_min_tag_size(); 1578 journal->j_wbufsize = n; 1579 journal->j_fc_wbuf = NULL; 1580 journal->j_wbuf = kmalloc_array(n, sizeof(struct buffer_head *), 1581 GFP_KERNEL); 1582 if (!journal->j_wbuf) 1583 goto err_cleanup; 1584 1585 err = percpu_counter_init(&journal->j_checkpoint_jh_count, 0, 1586 GFP_KERNEL); 1587 if (err) 1588 goto err_cleanup; 1589 1590 journal->j_shrink_transaction = NULL; 1591 1592 journal->j_shrinker = shrinker_alloc(0, "jbd2-journal:(%u:%u)", 1593 MAJOR(bdev->bd_dev), 1594 MINOR(bdev->bd_dev)); 1595 if (!journal->j_shrinker) { 1596 err = -ENOMEM; 1597 goto err_cleanup; 1598 } 1599 1600 journal->j_shrinker->scan_objects = jbd2_journal_shrink_scan; 1601 journal->j_shrinker->count_objects = jbd2_journal_shrink_count; 1602 journal->j_shrinker->batch = journal->j_max_transaction_buffers; 1603 journal->j_shrinker->private_data = journal; 1604 1605 shrinker_register(journal->j_shrinker); 1606 1607 return journal; 1608 1609 err_cleanup: 1610 percpu_counter_destroy(&journal->j_checkpoint_jh_count); 1611 if (journal->j_chksum_driver) 1612 crypto_free_shash(journal->j_chksum_driver); 1613 kfree(journal->j_wbuf); 1614 jbd2_journal_destroy_revoke(journal); 1615 journal_fail_superblock(journal); 1616 kfree(journal); 1617 return ERR_PTR(err); 1618 } 1619 1620 /* jbd2_journal_init_dev and jbd2_journal_init_inode: 1621 * 1622 * Create a journal structure assigned some fixed set of disk blocks to 1623 * the journal. We don't actually touch those disk blocks yet, but we 1624 * need to set up all of the mapping information to tell the journaling 1625 * system where the journal blocks are. 1626 * 1627 */ 1628 1629 /** 1630 * journal_t * jbd2_journal_init_dev() - creates and initialises a journal structure 1631 * @bdev: Block device on which to create the journal 1632 * @fs_dev: Device which hold journalled filesystem for this journal. 1633 * @start: Block nr Start of journal. 1634 * @len: Length of the journal in blocks. 1635 * @blocksize: blocksize of journalling device 1636 * 1637 * Returns: a newly created journal_t * 1638 * 1639 * jbd2_journal_init_dev creates a journal which maps a fixed contiguous 1640 * range of blocks on an arbitrary block device. 1641 * 1642 */ 1643 journal_t *jbd2_journal_init_dev(struct block_device *bdev, 1644 struct block_device *fs_dev, 1645 unsigned long long start, int len, int blocksize) 1646 { 1647 journal_t *journal; 1648 1649 journal = journal_init_common(bdev, fs_dev, start, len, blocksize); 1650 if (IS_ERR(journal)) 1651 return ERR_CAST(journal); 1652 1653 snprintf(journal->j_devname, sizeof(journal->j_devname), 1654 "%pg", journal->j_dev); 1655 strreplace(journal->j_devname, '/', '!'); 1656 jbd2_stats_proc_init(journal); 1657 1658 return journal; 1659 } 1660 1661 /** 1662 * journal_t * jbd2_journal_init_inode () - creates a journal which maps to a inode. 1663 * @inode: An inode to create the journal in 1664 * 1665 * jbd2_journal_init_inode creates a journal which maps an on-disk inode as 1666 * the journal. The inode must exist already, must support bmap() and 1667 * must have all data blocks preallocated. 1668 */ 1669 journal_t *jbd2_journal_init_inode(struct inode *inode) 1670 { 1671 journal_t *journal; 1672 sector_t blocknr; 1673 int err = 0; 1674 1675 blocknr = 0; 1676 err = bmap(inode, &blocknr); 1677 if (err || !blocknr) { 1678 pr_err("%s: Cannot locate journal superblock\n", __func__); 1679 return err ? ERR_PTR(err) : ERR_PTR(-EINVAL); 1680 } 1681 1682 jbd2_debug(1, "JBD2: inode %s/%ld, size %lld, bits %d, blksize %ld\n", 1683 inode->i_sb->s_id, inode->i_ino, (long long) inode->i_size, 1684 inode->i_sb->s_blocksize_bits, inode->i_sb->s_blocksize); 1685 1686 journal = journal_init_common(inode->i_sb->s_bdev, inode->i_sb->s_bdev, 1687 blocknr, inode->i_size >> inode->i_sb->s_blocksize_bits, 1688 inode->i_sb->s_blocksize); 1689 if (IS_ERR(journal)) 1690 return ERR_CAST(journal); 1691 1692 journal->j_inode = inode; 1693 snprintf(journal->j_devname, sizeof(journal->j_devname), 1694 "%pg-%lu", journal->j_dev, journal->j_inode->i_ino); 1695 strreplace(journal->j_devname, '/', '!'); 1696 jbd2_stats_proc_init(journal); 1697 1698 return journal; 1699 } 1700 1701 /* 1702 * Given a journal_t structure, initialise the various fields for 1703 * startup of a new journaling session. We use this both when creating 1704 * a journal, and after recovering an old journal to reset it for 1705 * subsequent use. 1706 */ 1707 1708 static int journal_reset(journal_t *journal) 1709 { 1710 journal_superblock_t *sb = journal->j_superblock; 1711 unsigned long long first, last; 1712 1713 first = be32_to_cpu(sb->s_first); 1714 last = be32_to_cpu(sb->s_maxlen); 1715 if (first + JBD2_MIN_JOURNAL_BLOCKS > last + 1) { 1716 printk(KERN_ERR "JBD2: Journal too short (blocks %llu-%llu).\n", 1717 first, last); 1718 journal_fail_superblock(journal); 1719 return -EINVAL; 1720 } 1721 1722 journal->j_first = first; 1723 journal->j_last = last; 1724 1725 if (journal->j_head != 0 && journal->j_flags & JBD2_CYCLE_RECORD) { 1726 /* 1727 * Disable the cycled recording mode if the journal head block 1728 * number is not correct. 1729 */ 1730 if (journal->j_head < first || journal->j_head >= last) { 1731 printk(KERN_WARNING "JBD2: Incorrect Journal head block %lu, " 1732 "disable journal_cycle_record\n", 1733 journal->j_head); 1734 journal->j_head = journal->j_first; 1735 } 1736 } else { 1737 journal->j_head = journal->j_first; 1738 } 1739 journal->j_tail = journal->j_head; 1740 journal->j_free = journal->j_last - journal->j_first; 1741 1742 journal->j_tail_sequence = journal->j_transaction_sequence; 1743 journal->j_commit_sequence = journal->j_transaction_sequence - 1; 1744 journal->j_commit_request = journal->j_commit_sequence; 1745 1746 journal->j_max_transaction_buffers = jbd2_journal_get_max_txn_bufs(journal); 1747 1748 /* 1749 * Now that journal recovery is done, turn fast commits off here. This 1750 * way, if fast commit was enabled before the crash but if now FS has 1751 * disabled it, we don't enable fast commits. 1752 */ 1753 jbd2_clear_feature_fast_commit(journal); 1754 1755 /* 1756 * As a special case, if the on-disk copy is already marked as needing 1757 * no recovery (s_start == 0), then we can safely defer the superblock 1758 * update until the next commit by setting JBD2_FLUSHED. This avoids 1759 * attempting a write to a potential-readonly device. 1760 */ 1761 if (sb->s_start == 0) { 1762 jbd2_debug(1, "JBD2: Skipping superblock update on recovered sb " 1763 "(start %ld, seq %u, errno %d)\n", 1764 journal->j_tail, journal->j_tail_sequence, 1765 journal->j_errno); 1766 journal->j_flags |= JBD2_FLUSHED; 1767 } else { 1768 /* Lock here to make assertions happy... */ 1769 mutex_lock_io(&journal->j_checkpoint_mutex); 1770 /* 1771 * Update log tail information. We use REQ_FUA since new 1772 * transaction will start reusing journal space and so we 1773 * must make sure information about current log tail is on 1774 * disk before that. 1775 */ 1776 jbd2_journal_update_sb_log_tail(journal, 1777 journal->j_tail_sequence, 1778 journal->j_tail, REQ_FUA); 1779 mutex_unlock(&journal->j_checkpoint_mutex); 1780 } 1781 return jbd2_journal_start_thread(journal); 1782 } 1783 1784 /* 1785 * This function expects that the caller will have locked the journal 1786 * buffer head, and will return with it unlocked 1787 */ 1788 static int jbd2_write_superblock(journal_t *journal, blk_opf_t write_flags) 1789 { 1790 struct buffer_head *bh = journal->j_sb_buffer; 1791 journal_superblock_t *sb = journal->j_superblock; 1792 int ret = 0; 1793 1794 /* Buffer got discarded which means block device got invalidated */ 1795 if (!buffer_mapped(bh)) { 1796 unlock_buffer(bh); 1797 return -EIO; 1798 } 1799 1800 /* 1801 * Always set high priority flags to exempt from block layer's 1802 * QOS policies, e.g. writeback throttle. 1803 */ 1804 write_flags |= JBD2_JOURNAL_REQ_FLAGS; 1805 if (!(journal->j_flags & JBD2_BARRIER)) 1806 write_flags &= ~(REQ_FUA | REQ_PREFLUSH); 1807 1808 trace_jbd2_write_superblock(journal, write_flags); 1809 1810 if (buffer_write_io_error(bh)) { 1811 /* 1812 * Oh, dear. A previous attempt to write the journal 1813 * superblock failed. This could happen because the 1814 * USB device was yanked out. Or it could happen to 1815 * be a transient write error and maybe the block will 1816 * be remapped. Nothing we can do but to retry the 1817 * write and hope for the best. 1818 */ 1819 printk(KERN_ERR "JBD2: previous I/O error detected " 1820 "for journal superblock update for %s.\n", 1821 journal->j_devname); 1822 clear_buffer_write_io_error(bh); 1823 set_buffer_uptodate(bh); 1824 } 1825 if (jbd2_journal_has_csum_v2or3(journal)) 1826 sb->s_checksum = jbd2_superblock_csum(journal, sb); 1827 get_bh(bh); 1828 bh->b_end_io = end_buffer_write_sync; 1829 submit_bh(REQ_OP_WRITE | write_flags, bh); 1830 wait_on_buffer(bh); 1831 if (buffer_write_io_error(bh)) { 1832 clear_buffer_write_io_error(bh); 1833 set_buffer_uptodate(bh); 1834 ret = -EIO; 1835 } 1836 if (ret) { 1837 printk(KERN_ERR "JBD2: I/O error when updating journal superblock for %s.\n", 1838 journal->j_devname); 1839 if (!is_journal_aborted(journal)) 1840 jbd2_journal_abort(journal, ret); 1841 } 1842 1843 return ret; 1844 } 1845 1846 /** 1847 * jbd2_journal_update_sb_log_tail() - Update log tail in journal sb on disk. 1848 * @journal: The journal to update. 1849 * @tail_tid: TID of the new transaction at the tail of the log 1850 * @tail_block: The first block of the transaction at the tail of the log 1851 * @write_flags: Flags for the journal sb write operation 1852 * 1853 * Update a journal's superblock information about log tail and write it to 1854 * disk, waiting for the IO to complete. 1855 */ 1856 int jbd2_journal_update_sb_log_tail(journal_t *journal, tid_t tail_tid, 1857 unsigned long tail_block, 1858 blk_opf_t write_flags) 1859 { 1860 journal_superblock_t *sb = journal->j_superblock; 1861 int ret; 1862 1863 if (is_journal_aborted(journal)) 1864 return -EIO; 1865 if (jbd2_check_fs_dev_write_error(journal)) { 1866 jbd2_journal_abort(journal, -EIO); 1867 return -EIO; 1868 } 1869 1870 BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex)); 1871 jbd2_debug(1, "JBD2: updating superblock (start %lu, seq %u)\n", 1872 tail_block, tail_tid); 1873 1874 lock_buffer(journal->j_sb_buffer); 1875 sb->s_sequence = cpu_to_be32(tail_tid); 1876 sb->s_start = cpu_to_be32(tail_block); 1877 1878 ret = jbd2_write_superblock(journal, write_flags); 1879 if (ret) 1880 goto out; 1881 1882 /* Log is no longer empty */ 1883 write_lock(&journal->j_state_lock); 1884 WARN_ON(!sb->s_sequence); 1885 journal->j_flags &= ~JBD2_FLUSHED; 1886 write_unlock(&journal->j_state_lock); 1887 1888 out: 1889 return ret; 1890 } 1891 1892 /** 1893 * jbd2_mark_journal_empty() - Mark on disk journal as empty. 1894 * @journal: The journal to update. 1895 * @write_flags: Flags for the journal sb write operation 1896 * 1897 * Update a journal's dynamic superblock fields to show that journal is empty. 1898 * Write updated superblock to disk waiting for IO to complete. 1899 */ 1900 static void jbd2_mark_journal_empty(journal_t *journal, blk_opf_t write_flags) 1901 { 1902 journal_superblock_t *sb = journal->j_superblock; 1903 bool had_fast_commit = false; 1904 1905 BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex)); 1906 lock_buffer(journal->j_sb_buffer); 1907 if (sb->s_start == 0) { /* Is it already empty? */ 1908 unlock_buffer(journal->j_sb_buffer); 1909 return; 1910 } 1911 1912 jbd2_debug(1, "JBD2: Marking journal as empty (seq %u)\n", 1913 journal->j_tail_sequence); 1914 1915 sb->s_sequence = cpu_to_be32(journal->j_tail_sequence); 1916 sb->s_start = cpu_to_be32(0); 1917 sb->s_head = cpu_to_be32(journal->j_head); 1918 if (jbd2_has_feature_fast_commit(journal)) { 1919 /* 1920 * When journal is clean, no need to commit fast commit flag and 1921 * make file system incompatible with older kernels. 1922 */ 1923 jbd2_clear_feature_fast_commit(journal); 1924 had_fast_commit = true; 1925 } 1926 1927 jbd2_write_superblock(journal, write_flags); 1928 1929 if (had_fast_commit) 1930 jbd2_set_feature_fast_commit(journal); 1931 1932 /* Log is no longer empty */ 1933 write_lock(&journal->j_state_lock); 1934 journal->j_flags |= JBD2_FLUSHED; 1935 write_unlock(&journal->j_state_lock); 1936 } 1937 1938 /** 1939 * __jbd2_journal_erase() - Discard or zeroout journal blocks (excluding superblock) 1940 * @journal: The journal to erase. 1941 * @flags: A discard/zeroout request is sent for each physically contigous 1942 * region of the journal. Either JBD2_JOURNAL_FLUSH_DISCARD or 1943 * JBD2_JOURNAL_FLUSH_ZEROOUT must be set to determine which operation 1944 * to perform. 1945 * 1946 * Note: JBD2_JOURNAL_FLUSH_ZEROOUT attempts to use hardware offload. Zeroes 1947 * will be explicitly written if no hardware offload is available, see 1948 * blkdev_issue_zeroout for more details. 1949 */ 1950 static int __jbd2_journal_erase(journal_t *journal, unsigned int flags) 1951 { 1952 int err = 0; 1953 unsigned long block, log_offset; /* logical */ 1954 unsigned long long phys_block, block_start, block_stop; /* physical */ 1955 loff_t byte_start, byte_stop, byte_count; 1956 1957 /* flags must be set to either discard or zeroout */ 1958 if ((flags & ~JBD2_JOURNAL_FLUSH_VALID) || !flags || 1959 ((flags & JBD2_JOURNAL_FLUSH_DISCARD) && 1960 (flags & JBD2_JOURNAL_FLUSH_ZEROOUT))) 1961 return -EINVAL; 1962 1963 if ((flags & JBD2_JOURNAL_FLUSH_DISCARD) && 1964 !bdev_max_discard_sectors(journal->j_dev)) 1965 return -EOPNOTSUPP; 1966 1967 /* 1968 * lookup block mapping and issue discard/zeroout for each 1969 * contiguous region 1970 */ 1971 log_offset = be32_to_cpu(journal->j_superblock->s_first); 1972 block_start = ~0ULL; 1973 for (block = log_offset; block < journal->j_total_len; block++) { 1974 err = jbd2_journal_bmap(journal, block, &phys_block); 1975 if (err) { 1976 pr_err("JBD2: bad block at offset %lu", block); 1977 return err; 1978 } 1979 1980 if (block_start == ~0ULL) { 1981 block_start = phys_block; 1982 block_stop = block_start - 1; 1983 } 1984 1985 /* 1986 * last block not contiguous with current block, 1987 * process last contiguous region and return to this block on 1988 * next loop 1989 */ 1990 if (phys_block != block_stop + 1) { 1991 block--; 1992 } else { 1993 block_stop++; 1994 /* 1995 * if this isn't the last block of journal, 1996 * no need to process now because next block may also 1997 * be part of this contiguous region 1998 */ 1999 if (block != journal->j_total_len - 1) 2000 continue; 2001 } 2002 2003 /* 2004 * end of contiguous region or this is last block of journal, 2005 * take care of the region 2006 */ 2007 byte_start = block_start * journal->j_blocksize; 2008 byte_stop = block_stop * journal->j_blocksize; 2009 byte_count = (block_stop - block_start + 1) * 2010 journal->j_blocksize; 2011 2012 truncate_inode_pages_range(journal->j_dev->bd_inode->i_mapping, 2013 byte_start, byte_stop); 2014 2015 if (flags & JBD2_JOURNAL_FLUSH_DISCARD) { 2016 err = blkdev_issue_discard(journal->j_dev, 2017 byte_start >> SECTOR_SHIFT, 2018 byte_count >> SECTOR_SHIFT, 2019 GFP_NOFS); 2020 } else if (flags & JBD2_JOURNAL_FLUSH_ZEROOUT) { 2021 err = blkdev_issue_zeroout(journal->j_dev, 2022 byte_start >> SECTOR_SHIFT, 2023 byte_count >> SECTOR_SHIFT, 2024 GFP_NOFS, 0); 2025 } 2026 2027 if (unlikely(err != 0)) { 2028 pr_err("JBD2: (error %d) unable to wipe journal at physical blocks %llu - %llu", 2029 err, block_start, block_stop); 2030 return err; 2031 } 2032 2033 /* reset start and stop after processing a region */ 2034 block_start = ~0ULL; 2035 } 2036 2037 return blkdev_issue_flush(journal->j_dev); 2038 } 2039 2040 /** 2041 * jbd2_journal_update_sb_errno() - Update error in the journal. 2042 * @journal: The journal to update. 2043 * 2044 * Update a journal's errno. Write updated superblock to disk waiting for IO 2045 * to complete. 2046 */ 2047 void jbd2_journal_update_sb_errno(journal_t *journal) 2048 { 2049 journal_superblock_t *sb = journal->j_superblock; 2050 int errcode; 2051 2052 lock_buffer(journal->j_sb_buffer); 2053 errcode = journal->j_errno; 2054 if (errcode == -ESHUTDOWN) 2055 errcode = 0; 2056 jbd2_debug(1, "JBD2: updating superblock error (errno %d)\n", errcode); 2057 sb->s_errno = cpu_to_be32(errcode); 2058 2059 jbd2_write_superblock(journal, REQ_FUA); 2060 } 2061 EXPORT_SYMBOL(jbd2_journal_update_sb_errno); 2062 2063 /** 2064 * jbd2_journal_load() - Read journal from disk. 2065 * @journal: Journal to act on. 2066 * 2067 * Given a journal_t structure which tells us which disk blocks contain 2068 * a journal, read the journal from disk to initialise the in-memory 2069 * structures. 2070 */ 2071 int jbd2_journal_load(journal_t *journal) 2072 { 2073 int err; 2074 journal_superblock_t *sb = journal->j_superblock; 2075 2076 /* 2077 * Create a slab for this blocksize 2078 */ 2079 err = jbd2_journal_create_slab(be32_to_cpu(sb->s_blocksize)); 2080 if (err) 2081 return err; 2082 2083 /* Let the recovery code check whether it needs to recover any 2084 * data from the journal. */ 2085 err = jbd2_journal_recover(journal); 2086 if (err) { 2087 pr_warn("JBD2: journal recovery failed\n"); 2088 return err; 2089 } 2090 2091 if (journal->j_failed_commit) { 2092 printk(KERN_ERR "JBD2: journal transaction %u on %s " 2093 "is corrupt.\n", journal->j_failed_commit, 2094 journal->j_devname); 2095 return -EFSCORRUPTED; 2096 } 2097 /* 2098 * clear JBD2_ABORT flag initialized in journal_init_common 2099 * here to update log tail information with the newest seq. 2100 */ 2101 journal->j_flags &= ~JBD2_ABORT; 2102 2103 /* OK, we've finished with the dynamic journal bits: 2104 * reinitialise the dynamic contents of the superblock in memory 2105 * and reset them on disk. */ 2106 err = journal_reset(journal); 2107 if (err) { 2108 pr_warn("JBD2: journal reset failed\n"); 2109 return err; 2110 } 2111 2112 journal->j_flags |= JBD2_LOADED; 2113 return 0; 2114 } 2115 2116 /** 2117 * jbd2_journal_destroy() - Release a journal_t structure. 2118 * @journal: Journal to act on. 2119 * 2120 * Release a journal_t structure once it is no longer in use by the 2121 * journaled object. 2122 * Return <0 if we couldn't clean up the journal. 2123 */ 2124 int jbd2_journal_destroy(journal_t *journal) 2125 { 2126 int err = 0; 2127 2128 /* Wait for the commit thread to wake up and die. */ 2129 journal_kill_thread(journal); 2130 2131 /* Force a final log commit */ 2132 if (journal->j_running_transaction) 2133 jbd2_journal_commit_transaction(journal); 2134 2135 /* Force any old transactions to disk */ 2136 2137 /* Totally anal locking here... */ 2138 spin_lock(&journal->j_list_lock); 2139 while (journal->j_checkpoint_transactions != NULL) { 2140 spin_unlock(&journal->j_list_lock); 2141 mutex_lock_io(&journal->j_checkpoint_mutex); 2142 err = jbd2_log_do_checkpoint(journal); 2143 mutex_unlock(&journal->j_checkpoint_mutex); 2144 /* 2145 * If checkpointing failed, just free the buffers to avoid 2146 * looping forever 2147 */ 2148 if (err) { 2149 jbd2_journal_destroy_checkpoint(journal); 2150 spin_lock(&journal->j_list_lock); 2151 break; 2152 } 2153 spin_lock(&journal->j_list_lock); 2154 } 2155 2156 J_ASSERT(journal->j_running_transaction == NULL); 2157 J_ASSERT(journal->j_committing_transaction == NULL); 2158 J_ASSERT(journal->j_checkpoint_transactions == NULL); 2159 spin_unlock(&journal->j_list_lock); 2160 2161 /* 2162 * OK, all checkpoint transactions have been checked, now check the 2163 * writeback errseq of fs dev and abort the journal if some buffer 2164 * failed to write back to the original location, otherwise the 2165 * filesystem may become inconsistent. 2166 */ 2167 if (!is_journal_aborted(journal) && 2168 jbd2_check_fs_dev_write_error(journal)) 2169 jbd2_journal_abort(journal, -EIO); 2170 2171 if (journal->j_sb_buffer) { 2172 if (!is_journal_aborted(journal)) { 2173 mutex_lock_io(&journal->j_checkpoint_mutex); 2174 2175 write_lock(&journal->j_state_lock); 2176 journal->j_tail_sequence = 2177 ++journal->j_transaction_sequence; 2178 write_unlock(&journal->j_state_lock); 2179 2180 jbd2_mark_journal_empty(journal, REQ_PREFLUSH | REQ_FUA); 2181 mutex_unlock(&journal->j_checkpoint_mutex); 2182 } else 2183 err = -EIO; 2184 brelse(journal->j_sb_buffer); 2185 } 2186 2187 if (journal->j_shrinker) { 2188 percpu_counter_destroy(&journal->j_checkpoint_jh_count); 2189 shrinker_free(journal->j_shrinker); 2190 } 2191 if (journal->j_proc_entry) 2192 jbd2_stats_proc_exit(journal); 2193 iput(journal->j_inode); 2194 if (journal->j_revoke) 2195 jbd2_journal_destroy_revoke(journal); 2196 if (journal->j_chksum_driver) 2197 crypto_free_shash(journal->j_chksum_driver); 2198 kfree(journal->j_fc_wbuf); 2199 kfree(journal->j_wbuf); 2200 kfree(journal); 2201 2202 return err; 2203 } 2204 2205 2206 /** 2207 * jbd2_journal_check_used_features() - Check if features specified are used. 2208 * @journal: Journal to check. 2209 * @compat: bitmask of compatible features 2210 * @ro: bitmask of features that force read-only mount 2211 * @incompat: bitmask of incompatible features 2212 * 2213 * Check whether the journal uses all of a given set of 2214 * features. Return true (non-zero) if it does. 2215 **/ 2216 2217 int jbd2_journal_check_used_features(journal_t *journal, unsigned long compat, 2218 unsigned long ro, unsigned long incompat) 2219 { 2220 journal_superblock_t *sb; 2221 2222 if (!compat && !ro && !incompat) 2223 return 1; 2224 if (!jbd2_format_support_feature(journal)) 2225 return 0; 2226 2227 sb = journal->j_superblock; 2228 2229 if (((be32_to_cpu(sb->s_feature_compat) & compat) == compat) && 2230 ((be32_to_cpu(sb->s_feature_ro_compat) & ro) == ro) && 2231 ((be32_to_cpu(sb->s_feature_incompat) & incompat) == incompat)) 2232 return 1; 2233 2234 return 0; 2235 } 2236 2237 /** 2238 * jbd2_journal_check_available_features() - Check feature set in journalling layer 2239 * @journal: Journal to check. 2240 * @compat: bitmask of compatible features 2241 * @ro: bitmask of features that force read-only mount 2242 * @incompat: bitmask of incompatible features 2243 * 2244 * Check whether the journaling code supports the use of 2245 * all of a given set of features on this journal. Return true 2246 * (non-zero) if it can. */ 2247 2248 int jbd2_journal_check_available_features(journal_t *journal, unsigned long compat, 2249 unsigned long ro, unsigned long incompat) 2250 { 2251 if (!compat && !ro && !incompat) 2252 return 1; 2253 2254 if (!jbd2_format_support_feature(journal)) 2255 return 0; 2256 2257 if ((compat & JBD2_KNOWN_COMPAT_FEATURES) == compat && 2258 (ro & JBD2_KNOWN_ROCOMPAT_FEATURES) == ro && 2259 (incompat & JBD2_KNOWN_INCOMPAT_FEATURES) == incompat) 2260 return 1; 2261 2262 return 0; 2263 } 2264 2265 static int 2266 jbd2_journal_initialize_fast_commit(journal_t *journal) 2267 { 2268 journal_superblock_t *sb = journal->j_superblock; 2269 unsigned long long num_fc_blks; 2270 2271 num_fc_blks = jbd2_journal_get_num_fc_blks(sb); 2272 if (journal->j_last - num_fc_blks < JBD2_MIN_JOURNAL_BLOCKS) 2273 return -ENOSPC; 2274 2275 /* Are we called twice? */ 2276 WARN_ON(journal->j_fc_wbuf != NULL); 2277 journal->j_fc_wbuf = kmalloc_array(num_fc_blks, 2278 sizeof(struct buffer_head *), GFP_KERNEL); 2279 if (!journal->j_fc_wbuf) 2280 return -ENOMEM; 2281 2282 journal->j_fc_wbufsize = num_fc_blks; 2283 journal->j_fc_last = journal->j_last; 2284 journal->j_last = journal->j_fc_last - num_fc_blks; 2285 journal->j_fc_first = journal->j_last + 1; 2286 journal->j_fc_off = 0; 2287 journal->j_free = journal->j_last - journal->j_first; 2288 journal->j_max_transaction_buffers = 2289 jbd2_journal_get_max_txn_bufs(journal); 2290 2291 return 0; 2292 } 2293 2294 /** 2295 * jbd2_journal_set_features() - Mark a given journal feature in the superblock 2296 * @journal: Journal to act on. 2297 * @compat: bitmask of compatible features 2298 * @ro: bitmask of features that force read-only mount 2299 * @incompat: bitmask of incompatible features 2300 * 2301 * Mark a given journal feature as present on the 2302 * superblock. Returns true if the requested features could be set. 2303 * 2304 */ 2305 2306 int jbd2_journal_set_features(journal_t *journal, unsigned long compat, 2307 unsigned long ro, unsigned long incompat) 2308 { 2309 #define INCOMPAT_FEATURE_ON(f) \ 2310 ((incompat & (f)) && !(sb->s_feature_incompat & cpu_to_be32(f))) 2311 #define COMPAT_FEATURE_ON(f) \ 2312 ((compat & (f)) && !(sb->s_feature_compat & cpu_to_be32(f))) 2313 journal_superblock_t *sb; 2314 2315 if (jbd2_journal_check_used_features(journal, compat, ro, incompat)) 2316 return 1; 2317 2318 if (!jbd2_journal_check_available_features(journal, compat, ro, incompat)) 2319 return 0; 2320 2321 /* If enabling v2 checksums, turn on v3 instead */ 2322 if (incompat & JBD2_FEATURE_INCOMPAT_CSUM_V2) { 2323 incompat &= ~JBD2_FEATURE_INCOMPAT_CSUM_V2; 2324 incompat |= JBD2_FEATURE_INCOMPAT_CSUM_V3; 2325 } 2326 2327 /* Asking for checksumming v3 and v1? Only give them v3. */ 2328 if (incompat & JBD2_FEATURE_INCOMPAT_CSUM_V3 && 2329 compat & JBD2_FEATURE_COMPAT_CHECKSUM) 2330 compat &= ~JBD2_FEATURE_COMPAT_CHECKSUM; 2331 2332 jbd2_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n", 2333 compat, ro, incompat); 2334 2335 sb = journal->j_superblock; 2336 2337 if (incompat & JBD2_FEATURE_INCOMPAT_FAST_COMMIT) { 2338 if (jbd2_journal_initialize_fast_commit(journal)) { 2339 pr_err("JBD2: Cannot enable fast commits.\n"); 2340 return 0; 2341 } 2342 } 2343 2344 /* Load the checksum driver if necessary */ 2345 if ((journal->j_chksum_driver == NULL) && 2346 INCOMPAT_FEATURE_ON(JBD2_FEATURE_INCOMPAT_CSUM_V3)) { 2347 journal->j_chksum_driver = crypto_alloc_shash("crc32c", 0, 0); 2348 if (IS_ERR(journal->j_chksum_driver)) { 2349 printk(KERN_ERR "JBD2: Cannot load crc32c driver.\n"); 2350 journal->j_chksum_driver = NULL; 2351 return 0; 2352 } 2353 /* Precompute checksum seed for all metadata */ 2354 journal->j_csum_seed = jbd2_chksum(journal, ~0, sb->s_uuid, 2355 sizeof(sb->s_uuid)); 2356 } 2357 2358 lock_buffer(journal->j_sb_buffer); 2359 2360 /* If enabling v3 checksums, update superblock */ 2361 if (INCOMPAT_FEATURE_ON(JBD2_FEATURE_INCOMPAT_CSUM_V3)) { 2362 sb->s_checksum_type = JBD2_CRC32C_CHKSUM; 2363 sb->s_feature_compat &= 2364 ~cpu_to_be32(JBD2_FEATURE_COMPAT_CHECKSUM); 2365 } 2366 2367 /* If enabling v1 checksums, downgrade superblock */ 2368 if (COMPAT_FEATURE_ON(JBD2_FEATURE_COMPAT_CHECKSUM)) 2369 sb->s_feature_incompat &= 2370 ~cpu_to_be32(JBD2_FEATURE_INCOMPAT_CSUM_V2 | 2371 JBD2_FEATURE_INCOMPAT_CSUM_V3); 2372 2373 sb->s_feature_compat |= cpu_to_be32(compat); 2374 sb->s_feature_ro_compat |= cpu_to_be32(ro); 2375 sb->s_feature_incompat |= cpu_to_be32(incompat); 2376 unlock_buffer(journal->j_sb_buffer); 2377 journal->j_revoke_records_per_block = 2378 journal_revoke_records_per_block(journal); 2379 2380 return 1; 2381 #undef COMPAT_FEATURE_ON 2382 #undef INCOMPAT_FEATURE_ON 2383 } 2384 2385 /* 2386 * jbd2_journal_clear_features() - Clear a given journal feature in the 2387 * superblock 2388 * @journal: Journal to act on. 2389 * @compat: bitmask of compatible features 2390 * @ro: bitmask of features that force read-only mount 2391 * @incompat: bitmask of incompatible features 2392 * 2393 * Clear a given journal feature as present on the 2394 * superblock. 2395 */ 2396 void jbd2_journal_clear_features(journal_t *journal, unsigned long compat, 2397 unsigned long ro, unsigned long incompat) 2398 { 2399 journal_superblock_t *sb; 2400 2401 jbd2_debug(1, "Clear features 0x%lx/0x%lx/0x%lx\n", 2402 compat, ro, incompat); 2403 2404 sb = journal->j_superblock; 2405 2406 sb->s_feature_compat &= ~cpu_to_be32(compat); 2407 sb->s_feature_ro_compat &= ~cpu_to_be32(ro); 2408 sb->s_feature_incompat &= ~cpu_to_be32(incompat); 2409 journal->j_revoke_records_per_block = 2410 journal_revoke_records_per_block(journal); 2411 } 2412 EXPORT_SYMBOL(jbd2_journal_clear_features); 2413 2414 /** 2415 * jbd2_journal_flush() - Flush journal 2416 * @journal: Journal to act on. 2417 * @flags: optional operation on the journal blocks after the flush (see below) 2418 * 2419 * Flush all data for a given journal to disk and empty the journal. 2420 * Filesystems can use this when remounting readonly to ensure that 2421 * recovery does not need to happen on remount. Optionally, a discard or zeroout 2422 * can be issued on the journal blocks after flushing. 2423 * 2424 * flags: 2425 * JBD2_JOURNAL_FLUSH_DISCARD: issues discards for the journal blocks 2426 * JBD2_JOURNAL_FLUSH_ZEROOUT: issues zeroouts for the journal blocks 2427 */ 2428 int jbd2_journal_flush(journal_t *journal, unsigned int flags) 2429 { 2430 int err = 0; 2431 transaction_t *transaction = NULL; 2432 2433 write_lock(&journal->j_state_lock); 2434 2435 /* Force everything buffered to the log... */ 2436 if (journal->j_running_transaction) { 2437 transaction = journal->j_running_transaction; 2438 __jbd2_log_start_commit(journal, transaction->t_tid); 2439 } else if (journal->j_committing_transaction) 2440 transaction = journal->j_committing_transaction; 2441 2442 /* Wait for the log commit to complete... */ 2443 if (transaction) { 2444 tid_t tid = transaction->t_tid; 2445 2446 write_unlock(&journal->j_state_lock); 2447 jbd2_log_wait_commit(journal, tid); 2448 } else { 2449 write_unlock(&journal->j_state_lock); 2450 } 2451 2452 /* ...and flush everything in the log out to disk. */ 2453 spin_lock(&journal->j_list_lock); 2454 while (!err && journal->j_checkpoint_transactions != NULL) { 2455 spin_unlock(&journal->j_list_lock); 2456 mutex_lock_io(&journal->j_checkpoint_mutex); 2457 err = jbd2_log_do_checkpoint(journal); 2458 mutex_unlock(&journal->j_checkpoint_mutex); 2459 spin_lock(&journal->j_list_lock); 2460 } 2461 spin_unlock(&journal->j_list_lock); 2462 2463 if (is_journal_aborted(journal)) 2464 return -EIO; 2465 2466 mutex_lock_io(&journal->j_checkpoint_mutex); 2467 if (!err) { 2468 err = jbd2_cleanup_journal_tail(journal); 2469 if (err < 0) { 2470 mutex_unlock(&journal->j_checkpoint_mutex); 2471 goto out; 2472 } 2473 err = 0; 2474 } 2475 2476 /* Finally, mark the journal as really needing no recovery. 2477 * This sets s_start==0 in the underlying superblock, which is 2478 * the magic code for a fully-recovered superblock. Any future 2479 * commits of data to the journal will restore the current 2480 * s_start value. */ 2481 jbd2_mark_journal_empty(journal, REQ_FUA); 2482 2483 if (flags) 2484 err = __jbd2_journal_erase(journal, flags); 2485 2486 mutex_unlock(&journal->j_checkpoint_mutex); 2487 write_lock(&journal->j_state_lock); 2488 J_ASSERT(!journal->j_running_transaction); 2489 J_ASSERT(!journal->j_committing_transaction); 2490 J_ASSERT(!journal->j_checkpoint_transactions); 2491 J_ASSERT(journal->j_head == journal->j_tail); 2492 J_ASSERT(journal->j_tail_sequence == journal->j_transaction_sequence); 2493 write_unlock(&journal->j_state_lock); 2494 out: 2495 return err; 2496 } 2497 2498 /** 2499 * jbd2_journal_wipe() - Wipe journal contents 2500 * @journal: Journal to act on. 2501 * @write: flag (see below) 2502 * 2503 * Wipe out all of the contents of a journal, safely. This will produce 2504 * a warning if the journal contains any valid recovery information. 2505 * Must be called between journal_init_*() and jbd2_journal_load(). 2506 * 2507 * If 'write' is non-zero, then we wipe out the journal on disk; otherwise 2508 * we merely suppress recovery. 2509 */ 2510 2511 int jbd2_journal_wipe(journal_t *journal, int write) 2512 { 2513 int err; 2514 2515 J_ASSERT (!(journal->j_flags & JBD2_LOADED)); 2516 2517 if (!journal->j_tail) 2518 return 0; 2519 2520 printk(KERN_WARNING "JBD2: %s recovery information on journal\n", 2521 write ? "Clearing" : "Ignoring"); 2522 2523 err = jbd2_journal_skip_recovery(journal); 2524 if (write) { 2525 /* Lock to make assertions happy... */ 2526 mutex_lock_io(&journal->j_checkpoint_mutex); 2527 jbd2_mark_journal_empty(journal, REQ_FUA); 2528 mutex_unlock(&journal->j_checkpoint_mutex); 2529 } 2530 2531 return err; 2532 } 2533 2534 /** 2535 * jbd2_journal_abort () - Shutdown the journal immediately. 2536 * @journal: the journal to shutdown. 2537 * @errno: an error number to record in the journal indicating 2538 * the reason for the shutdown. 2539 * 2540 * Perform a complete, immediate shutdown of the ENTIRE 2541 * journal (not of a single transaction). This operation cannot be 2542 * undone without closing and reopening the journal. 2543 * 2544 * The jbd2_journal_abort function is intended to support higher level error 2545 * recovery mechanisms such as the ext2/ext3 remount-readonly error 2546 * mode. 2547 * 2548 * Journal abort has very specific semantics. Any existing dirty, 2549 * unjournaled buffers in the main filesystem will still be written to 2550 * disk by bdflush, but the journaling mechanism will be suspended 2551 * immediately and no further transaction commits will be honoured. 2552 * 2553 * Any dirty, journaled buffers will be written back to disk without 2554 * hitting the journal. Atomicity cannot be guaranteed on an aborted 2555 * filesystem, but we _do_ attempt to leave as much data as possible 2556 * behind for fsck to use for cleanup. 2557 * 2558 * Any attempt to get a new transaction handle on a journal which is in 2559 * ABORT state will just result in an -EROFS error return. A 2560 * jbd2_journal_stop on an existing handle will return -EIO if we have 2561 * entered abort state during the update. 2562 * 2563 * Recursive transactions are not disturbed by journal abort until the 2564 * final jbd2_journal_stop, which will receive the -EIO error. 2565 * 2566 * Finally, the jbd2_journal_abort call allows the caller to supply an errno 2567 * which will be recorded (if possible) in the journal superblock. This 2568 * allows a client to record failure conditions in the middle of a 2569 * transaction without having to complete the transaction to record the 2570 * failure to disk. ext3_error, for example, now uses this 2571 * functionality. 2572 * 2573 */ 2574 2575 void jbd2_journal_abort(journal_t *journal, int errno) 2576 { 2577 transaction_t *transaction; 2578 2579 /* 2580 * Lock the aborting procedure until everything is done, this avoid 2581 * races between filesystem's error handling flow (e.g. ext4_abort()), 2582 * ensure panic after the error info is written into journal's 2583 * superblock. 2584 */ 2585 mutex_lock(&journal->j_abort_mutex); 2586 /* 2587 * ESHUTDOWN always takes precedence because a file system check 2588 * caused by any other journal abort error is not required after 2589 * a shutdown triggered. 2590 */ 2591 write_lock(&journal->j_state_lock); 2592 if (journal->j_flags & JBD2_ABORT) { 2593 int old_errno = journal->j_errno; 2594 2595 write_unlock(&journal->j_state_lock); 2596 if (old_errno != -ESHUTDOWN && errno == -ESHUTDOWN) { 2597 journal->j_errno = errno; 2598 jbd2_journal_update_sb_errno(journal); 2599 } 2600 mutex_unlock(&journal->j_abort_mutex); 2601 return; 2602 } 2603 2604 /* 2605 * Mark the abort as occurred and start current running transaction 2606 * to release all journaled buffer. 2607 */ 2608 pr_err("Aborting journal on device %s.\n", journal->j_devname); 2609 2610 journal->j_flags |= JBD2_ABORT; 2611 journal->j_errno = errno; 2612 transaction = journal->j_running_transaction; 2613 if (transaction) 2614 __jbd2_log_start_commit(journal, transaction->t_tid); 2615 write_unlock(&journal->j_state_lock); 2616 2617 /* 2618 * Record errno to the journal super block, so that fsck and jbd2 2619 * layer could realise that a filesystem check is needed. 2620 */ 2621 jbd2_journal_update_sb_errno(journal); 2622 mutex_unlock(&journal->j_abort_mutex); 2623 } 2624 2625 /** 2626 * jbd2_journal_errno() - returns the journal's error state. 2627 * @journal: journal to examine. 2628 * 2629 * This is the errno number set with jbd2_journal_abort(), the last 2630 * time the journal was mounted - if the journal was stopped 2631 * without calling abort this will be 0. 2632 * 2633 * If the journal has been aborted on this mount time -EROFS will 2634 * be returned. 2635 */ 2636 int jbd2_journal_errno(journal_t *journal) 2637 { 2638 int err; 2639 2640 read_lock(&journal->j_state_lock); 2641 if (journal->j_flags & JBD2_ABORT) 2642 err = -EROFS; 2643 else 2644 err = journal->j_errno; 2645 read_unlock(&journal->j_state_lock); 2646 return err; 2647 } 2648 2649 /** 2650 * jbd2_journal_clear_err() - clears the journal's error state 2651 * @journal: journal to act on. 2652 * 2653 * An error must be cleared or acked to take a FS out of readonly 2654 * mode. 2655 */ 2656 int jbd2_journal_clear_err(journal_t *journal) 2657 { 2658 int err = 0; 2659 2660 write_lock(&journal->j_state_lock); 2661 if (journal->j_flags & JBD2_ABORT) 2662 err = -EROFS; 2663 else 2664 journal->j_errno = 0; 2665 write_unlock(&journal->j_state_lock); 2666 return err; 2667 } 2668 2669 /** 2670 * jbd2_journal_ack_err() - Ack journal err. 2671 * @journal: journal to act on. 2672 * 2673 * An error must be cleared or acked to take a FS out of readonly 2674 * mode. 2675 */ 2676 void jbd2_journal_ack_err(journal_t *journal) 2677 { 2678 write_lock(&journal->j_state_lock); 2679 if (journal->j_errno) 2680 journal->j_flags |= JBD2_ACK_ERR; 2681 write_unlock(&journal->j_state_lock); 2682 } 2683 2684 int jbd2_journal_blocks_per_page(struct inode *inode) 2685 { 2686 return 1 << (PAGE_SHIFT - inode->i_sb->s_blocksize_bits); 2687 } 2688 2689 /* 2690 * helper functions to deal with 32 or 64bit block numbers. 2691 */ 2692 size_t journal_tag_bytes(journal_t *journal) 2693 { 2694 size_t sz; 2695 2696 if (jbd2_has_feature_csum3(journal)) 2697 return sizeof(journal_block_tag3_t); 2698 2699 sz = sizeof(journal_block_tag_t); 2700 2701 if (jbd2_has_feature_csum2(journal)) 2702 sz += sizeof(__u16); 2703 2704 if (jbd2_has_feature_64bit(journal)) 2705 return sz; 2706 else 2707 return sz - sizeof(__u32); 2708 } 2709 2710 /* 2711 * JBD memory management 2712 * 2713 * These functions are used to allocate block-sized chunks of memory 2714 * used for making copies of buffer_head data. Very often it will be 2715 * page-sized chunks of data, but sometimes it will be in 2716 * sub-page-size chunks. (For example, 16k pages on Power systems 2717 * with a 4k block file system.) For blocks smaller than a page, we 2718 * use a SLAB allocator. There are slab caches for each block size, 2719 * which are allocated at mount time, if necessary, and we only free 2720 * (all of) the slab caches when/if the jbd2 module is unloaded. For 2721 * this reason we don't need to a mutex to protect access to 2722 * jbd2_slab[] allocating or releasing memory; only in 2723 * jbd2_journal_create_slab(). 2724 */ 2725 #define JBD2_MAX_SLABS 8 2726 static struct kmem_cache *jbd2_slab[JBD2_MAX_SLABS]; 2727 2728 static const char *jbd2_slab_names[JBD2_MAX_SLABS] = { 2729 "jbd2_1k", "jbd2_2k", "jbd2_4k", "jbd2_8k", 2730 "jbd2_16k", "jbd2_32k", "jbd2_64k", "jbd2_128k" 2731 }; 2732 2733 2734 static void jbd2_journal_destroy_slabs(void) 2735 { 2736 int i; 2737 2738 for (i = 0; i < JBD2_MAX_SLABS; i++) { 2739 kmem_cache_destroy(jbd2_slab[i]); 2740 jbd2_slab[i] = NULL; 2741 } 2742 } 2743 2744 static int jbd2_journal_create_slab(size_t size) 2745 { 2746 static DEFINE_MUTEX(jbd2_slab_create_mutex); 2747 int i = order_base_2(size) - 10; 2748 size_t slab_size; 2749 2750 if (size == PAGE_SIZE) 2751 return 0; 2752 2753 if (i >= JBD2_MAX_SLABS) 2754 return -EINVAL; 2755 2756 if (unlikely(i < 0)) 2757 i = 0; 2758 mutex_lock(&jbd2_slab_create_mutex); 2759 if (jbd2_slab[i]) { 2760 mutex_unlock(&jbd2_slab_create_mutex); 2761 return 0; /* Already created */ 2762 } 2763 2764 slab_size = 1 << (i+10); 2765 jbd2_slab[i] = kmem_cache_create(jbd2_slab_names[i], slab_size, 2766 slab_size, 0, NULL); 2767 mutex_unlock(&jbd2_slab_create_mutex); 2768 if (!jbd2_slab[i]) { 2769 printk(KERN_EMERG "JBD2: no memory for jbd2_slab cache\n"); 2770 return -ENOMEM; 2771 } 2772 return 0; 2773 } 2774 2775 static struct kmem_cache *get_slab(size_t size) 2776 { 2777 int i = order_base_2(size) - 10; 2778 2779 BUG_ON(i >= JBD2_MAX_SLABS); 2780 if (unlikely(i < 0)) 2781 i = 0; 2782 BUG_ON(jbd2_slab[i] == NULL); 2783 return jbd2_slab[i]; 2784 } 2785 2786 void *jbd2_alloc(size_t size, gfp_t flags) 2787 { 2788 void *ptr; 2789 2790 BUG_ON(size & (size-1)); /* Must be a power of 2 */ 2791 2792 if (size < PAGE_SIZE) 2793 ptr = kmem_cache_alloc(get_slab(size), flags); 2794 else 2795 ptr = (void *)__get_free_pages(flags, get_order(size)); 2796 2797 /* Check alignment; SLUB has gotten this wrong in the past, 2798 * and this can lead to user data corruption! */ 2799 BUG_ON(((unsigned long) ptr) & (size-1)); 2800 2801 return ptr; 2802 } 2803 2804 void jbd2_free(void *ptr, size_t size) 2805 { 2806 if (size < PAGE_SIZE) 2807 kmem_cache_free(get_slab(size), ptr); 2808 else 2809 free_pages((unsigned long)ptr, get_order(size)); 2810 }; 2811 2812 /* 2813 * Journal_head storage management 2814 */ 2815 static struct kmem_cache *jbd2_journal_head_cache; 2816 #ifdef CONFIG_JBD2_DEBUG 2817 static atomic_t nr_journal_heads = ATOMIC_INIT(0); 2818 #endif 2819 2820 static int __init jbd2_journal_init_journal_head_cache(void) 2821 { 2822 J_ASSERT(!jbd2_journal_head_cache); 2823 jbd2_journal_head_cache = kmem_cache_create("jbd2_journal_head", 2824 sizeof(struct journal_head), 2825 0, /* offset */ 2826 SLAB_TEMPORARY | SLAB_TYPESAFE_BY_RCU, 2827 NULL); /* ctor */ 2828 if (!jbd2_journal_head_cache) { 2829 printk(KERN_EMERG "JBD2: no memory for journal_head cache\n"); 2830 return -ENOMEM; 2831 } 2832 return 0; 2833 } 2834 2835 static void jbd2_journal_destroy_journal_head_cache(void) 2836 { 2837 kmem_cache_destroy(jbd2_journal_head_cache); 2838 jbd2_journal_head_cache = NULL; 2839 } 2840 2841 /* 2842 * journal_head splicing and dicing 2843 */ 2844 static struct journal_head *journal_alloc_journal_head(void) 2845 { 2846 struct journal_head *ret; 2847 2848 #ifdef CONFIG_JBD2_DEBUG 2849 atomic_inc(&nr_journal_heads); 2850 #endif 2851 ret = kmem_cache_zalloc(jbd2_journal_head_cache, GFP_NOFS); 2852 if (!ret) { 2853 jbd2_debug(1, "out of memory for journal_head\n"); 2854 pr_notice_ratelimited("ENOMEM in %s, retrying.\n", __func__); 2855 ret = kmem_cache_zalloc(jbd2_journal_head_cache, 2856 GFP_NOFS | __GFP_NOFAIL); 2857 } 2858 if (ret) 2859 spin_lock_init(&ret->b_state_lock); 2860 return ret; 2861 } 2862 2863 static void journal_free_journal_head(struct journal_head *jh) 2864 { 2865 #ifdef CONFIG_JBD2_DEBUG 2866 atomic_dec(&nr_journal_heads); 2867 memset(jh, JBD2_POISON_FREE, sizeof(*jh)); 2868 #endif 2869 kmem_cache_free(jbd2_journal_head_cache, jh); 2870 } 2871 2872 /* 2873 * A journal_head is attached to a buffer_head whenever JBD has an 2874 * interest in the buffer. 2875 * 2876 * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit 2877 * is set. This bit is tested in core kernel code where we need to take 2878 * JBD-specific actions. Testing the zeroness of ->b_private is not reliable 2879 * there. 2880 * 2881 * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one. 2882 * 2883 * When a buffer has its BH_JBD bit set it is immune from being released by 2884 * core kernel code, mainly via ->b_count. 2885 * 2886 * A journal_head is detached from its buffer_head when the journal_head's 2887 * b_jcount reaches zero. Running transaction (b_transaction) and checkpoint 2888 * transaction (b_cp_transaction) hold their references to b_jcount. 2889 * 2890 * Various places in the kernel want to attach a journal_head to a buffer_head 2891 * _before_ attaching the journal_head to a transaction. To protect the 2892 * journal_head in this situation, jbd2_journal_add_journal_head elevates the 2893 * journal_head's b_jcount refcount by one. The caller must call 2894 * jbd2_journal_put_journal_head() to undo this. 2895 * 2896 * So the typical usage would be: 2897 * 2898 * (Attach a journal_head if needed. Increments b_jcount) 2899 * struct journal_head *jh = jbd2_journal_add_journal_head(bh); 2900 * ... 2901 * (Get another reference for transaction) 2902 * jbd2_journal_grab_journal_head(bh); 2903 * jh->b_transaction = xxx; 2904 * (Put original reference) 2905 * jbd2_journal_put_journal_head(jh); 2906 */ 2907 2908 /* 2909 * Give a buffer_head a journal_head. 2910 * 2911 * May sleep. 2912 */ 2913 struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh) 2914 { 2915 struct journal_head *jh; 2916 struct journal_head *new_jh = NULL; 2917 2918 repeat: 2919 if (!buffer_jbd(bh)) 2920 new_jh = journal_alloc_journal_head(); 2921 2922 jbd_lock_bh_journal_head(bh); 2923 if (buffer_jbd(bh)) { 2924 jh = bh2jh(bh); 2925 } else { 2926 J_ASSERT_BH(bh, 2927 (atomic_read(&bh->b_count) > 0) || 2928 (bh->b_folio && bh->b_folio->mapping)); 2929 2930 if (!new_jh) { 2931 jbd_unlock_bh_journal_head(bh); 2932 goto repeat; 2933 } 2934 2935 jh = new_jh; 2936 new_jh = NULL; /* We consumed it */ 2937 set_buffer_jbd(bh); 2938 bh->b_private = jh; 2939 jh->b_bh = bh; 2940 get_bh(bh); 2941 BUFFER_TRACE(bh, "added journal_head"); 2942 } 2943 jh->b_jcount++; 2944 jbd_unlock_bh_journal_head(bh); 2945 if (new_jh) 2946 journal_free_journal_head(new_jh); 2947 return bh->b_private; 2948 } 2949 2950 /* 2951 * Grab a ref against this buffer_head's journal_head. If it ended up not 2952 * having a journal_head, return NULL 2953 */ 2954 struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh) 2955 { 2956 struct journal_head *jh = NULL; 2957 2958 jbd_lock_bh_journal_head(bh); 2959 if (buffer_jbd(bh)) { 2960 jh = bh2jh(bh); 2961 jh->b_jcount++; 2962 } 2963 jbd_unlock_bh_journal_head(bh); 2964 return jh; 2965 } 2966 EXPORT_SYMBOL(jbd2_journal_grab_journal_head); 2967 2968 static void __journal_remove_journal_head(struct buffer_head *bh) 2969 { 2970 struct journal_head *jh = bh2jh(bh); 2971 2972 J_ASSERT_JH(jh, jh->b_transaction == NULL); 2973 J_ASSERT_JH(jh, jh->b_next_transaction == NULL); 2974 J_ASSERT_JH(jh, jh->b_cp_transaction == NULL); 2975 J_ASSERT_JH(jh, jh->b_jlist == BJ_None); 2976 J_ASSERT_BH(bh, buffer_jbd(bh)); 2977 J_ASSERT_BH(bh, jh2bh(jh) == bh); 2978 BUFFER_TRACE(bh, "remove journal_head"); 2979 2980 /* Unlink before dropping the lock */ 2981 bh->b_private = NULL; 2982 jh->b_bh = NULL; /* debug, really */ 2983 clear_buffer_jbd(bh); 2984 } 2985 2986 static void journal_release_journal_head(struct journal_head *jh, size_t b_size) 2987 { 2988 if (jh->b_frozen_data) { 2989 printk(KERN_WARNING "%s: freeing b_frozen_data\n", __func__); 2990 jbd2_free(jh->b_frozen_data, b_size); 2991 } 2992 if (jh->b_committed_data) { 2993 printk(KERN_WARNING "%s: freeing b_committed_data\n", __func__); 2994 jbd2_free(jh->b_committed_data, b_size); 2995 } 2996 journal_free_journal_head(jh); 2997 } 2998 2999 /* 3000 * Drop a reference on the passed journal_head. If it fell to zero then 3001 * release the journal_head from the buffer_head. 3002 */ 3003 void jbd2_journal_put_journal_head(struct journal_head *jh) 3004 { 3005 struct buffer_head *bh = jh2bh(jh); 3006 3007 jbd_lock_bh_journal_head(bh); 3008 J_ASSERT_JH(jh, jh->b_jcount > 0); 3009 --jh->b_jcount; 3010 if (!jh->b_jcount) { 3011 __journal_remove_journal_head(bh); 3012 jbd_unlock_bh_journal_head(bh); 3013 journal_release_journal_head(jh, bh->b_size); 3014 __brelse(bh); 3015 } else { 3016 jbd_unlock_bh_journal_head(bh); 3017 } 3018 } 3019 EXPORT_SYMBOL(jbd2_journal_put_journal_head); 3020 3021 /* 3022 * Initialize jbd inode head 3023 */ 3024 void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode) 3025 { 3026 jinode->i_transaction = NULL; 3027 jinode->i_next_transaction = NULL; 3028 jinode->i_vfs_inode = inode; 3029 jinode->i_flags = 0; 3030 jinode->i_dirty_start = 0; 3031 jinode->i_dirty_end = 0; 3032 INIT_LIST_HEAD(&jinode->i_list); 3033 } 3034 3035 /* 3036 * Function to be called before we start removing inode from memory (i.e., 3037 * clear_inode() is a fine place to be called from). It removes inode from 3038 * transaction's lists. 3039 */ 3040 void jbd2_journal_release_jbd_inode(journal_t *journal, 3041 struct jbd2_inode *jinode) 3042 { 3043 if (!journal) 3044 return; 3045 restart: 3046 spin_lock(&journal->j_list_lock); 3047 /* Is commit writing out inode - we have to wait */ 3048 if (jinode->i_flags & JI_COMMIT_RUNNING) { 3049 wait_queue_head_t *wq; 3050 DEFINE_WAIT_BIT(wait, &jinode->i_flags, __JI_COMMIT_RUNNING); 3051 wq = bit_waitqueue(&jinode->i_flags, __JI_COMMIT_RUNNING); 3052 prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE); 3053 spin_unlock(&journal->j_list_lock); 3054 schedule(); 3055 finish_wait(wq, &wait.wq_entry); 3056 goto restart; 3057 } 3058 3059 if (jinode->i_transaction) { 3060 list_del(&jinode->i_list); 3061 jinode->i_transaction = NULL; 3062 } 3063 spin_unlock(&journal->j_list_lock); 3064 } 3065 3066 3067 #ifdef CONFIG_PROC_FS 3068 3069 #define JBD2_STATS_PROC_NAME "fs/jbd2" 3070 3071 static void __init jbd2_create_jbd_stats_proc_entry(void) 3072 { 3073 proc_jbd2_stats = proc_mkdir(JBD2_STATS_PROC_NAME, NULL); 3074 } 3075 3076 static void __exit jbd2_remove_jbd_stats_proc_entry(void) 3077 { 3078 if (proc_jbd2_stats) 3079 remove_proc_entry(JBD2_STATS_PROC_NAME, NULL); 3080 } 3081 3082 #else 3083 3084 #define jbd2_create_jbd_stats_proc_entry() do {} while (0) 3085 #define jbd2_remove_jbd_stats_proc_entry() do {} while (0) 3086 3087 #endif 3088 3089 struct kmem_cache *jbd2_handle_cache, *jbd2_inode_cache; 3090 3091 static int __init jbd2_journal_init_inode_cache(void) 3092 { 3093 J_ASSERT(!jbd2_inode_cache); 3094 jbd2_inode_cache = KMEM_CACHE(jbd2_inode, 0); 3095 if (!jbd2_inode_cache) { 3096 pr_emerg("JBD2: failed to create inode cache\n"); 3097 return -ENOMEM; 3098 } 3099 return 0; 3100 } 3101 3102 static int __init jbd2_journal_init_handle_cache(void) 3103 { 3104 J_ASSERT(!jbd2_handle_cache); 3105 jbd2_handle_cache = KMEM_CACHE(jbd2_journal_handle, SLAB_TEMPORARY); 3106 if (!jbd2_handle_cache) { 3107 printk(KERN_EMERG "JBD2: failed to create handle cache\n"); 3108 return -ENOMEM; 3109 } 3110 return 0; 3111 } 3112 3113 static void jbd2_journal_destroy_inode_cache(void) 3114 { 3115 kmem_cache_destroy(jbd2_inode_cache); 3116 jbd2_inode_cache = NULL; 3117 } 3118 3119 static void jbd2_journal_destroy_handle_cache(void) 3120 { 3121 kmem_cache_destroy(jbd2_handle_cache); 3122 jbd2_handle_cache = NULL; 3123 } 3124 3125 /* 3126 * Module startup and shutdown 3127 */ 3128 3129 static int __init journal_init_caches(void) 3130 { 3131 int ret; 3132 3133 ret = jbd2_journal_init_revoke_record_cache(); 3134 if (ret == 0) 3135 ret = jbd2_journal_init_revoke_table_cache(); 3136 if (ret == 0) 3137 ret = jbd2_journal_init_journal_head_cache(); 3138 if (ret == 0) 3139 ret = jbd2_journal_init_handle_cache(); 3140 if (ret == 0) 3141 ret = jbd2_journal_init_inode_cache(); 3142 if (ret == 0) 3143 ret = jbd2_journal_init_transaction_cache(); 3144 return ret; 3145 } 3146 3147 static void jbd2_journal_destroy_caches(void) 3148 { 3149 jbd2_journal_destroy_revoke_record_cache(); 3150 jbd2_journal_destroy_revoke_table_cache(); 3151 jbd2_journal_destroy_journal_head_cache(); 3152 jbd2_journal_destroy_handle_cache(); 3153 jbd2_journal_destroy_inode_cache(); 3154 jbd2_journal_destroy_transaction_cache(); 3155 jbd2_journal_destroy_slabs(); 3156 } 3157 3158 static int __init journal_init(void) 3159 { 3160 int ret; 3161 3162 BUILD_BUG_ON(sizeof(struct journal_superblock_s) != 1024); 3163 3164 ret = journal_init_caches(); 3165 if (ret == 0) { 3166 jbd2_create_jbd_stats_proc_entry(); 3167 } else { 3168 jbd2_journal_destroy_caches(); 3169 } 3170 return ret; 3171 } 3172 3173 static void __exit journal_exit(void) 3174 { 3175 #ifdef CONFIG_JBD2_DEBUG 3176 int n = atomic_read(&nr_journal_heads); 3177 if (n) 3178 printk(KERN_ERR "JBD2: leaked %d journal_heads!\n", n); 3179 #endif 3180 jbd2_remove_jbd_stats_proc_entry(); 3181 jbd2_journal_destroy_caches(); 3182 } 3183 3184 MODULE_LICENSE("GPL"); 3185 module_init(journal_init); 3186 module_exit(journal_exit); 3187 3188