1 /* 2 * linux/fs/jbd2/journal.c 3 * 4 * Written by Stephen C. Tweedie <sct@redhat.com>, 1998 5 * 6 * Copyright 1998 Red Hat corp --- All Rights Reserved 7 * 8 * This file is part of the Linux kernel and is made available under 9 * the terms of the GNU General Public License, version 2, or at your 10 * option, any later version, incorporated herein by reference. 11 * 12 * Generic filesystem journal-writing code; part of the ext2fs 13 * journaling system. 14 * 15 * This file manages journals: areas of disk reserved for logging 16 * transactional updates. This includes the kernel journaling thread 17 * which is responsible for scheduling updates to the log. 18 * 19 * We do not actually manage the physical storage of the journal in this 20 * file: that is left to a per-journal policy function, which allows us 21 * to store the journal within a filesystem-specified area for ext2 22 * journaling (ext2 can use a reserved inode for storing the log). 23 */ 24 25 #include <linux/module.h> 26 #include <linux/time.h> 27 #include <linux/fs.h> 28 #include <linux/jbd2.h> 29 #include <linux/errno.h> 30 #include <linux/slab.h> 31 #include <linux/init.h> 32 #include <linux/mm.h> 33 #include <linux/freezer.h> 34 #include <linux/pagemap.h> 35 #include <linux/kthread.h> 36 #include <linux/poison.h> 37 #include <linux/proc_fs.h> 38 #include <linux/seq_file.h> 39 #include <linux/math64.h> 40 #include <linux/hash.h> 41 #include <linux/log2.h> 42 #include <linux/vmalloc.h> 43 #include <linux/backing-dev.h> 44 #include <linux/bitops.h> 45 #include <linux/ratelimit.h> 46 47 #define CREATE_TRACE_POINTS 48 #include <trace/events/jbd2.h> 49 50 #include <asm/uaccess.h> 51 #include <asm/page.h> 52 53 #ifdef CONFIG_JBD2_DEBUG 54 ushort jbd2_journal_enable_debug __read_mostly; 55 EXPORT_SYMBOL(jbd2_journal_enable_debug); 56 57 module_param_named(jbd2_debug, jbd2_journal_enable_debug, ushort, 0644); 58 MODULE_PARM_DESC(jbd2_debug, "Debugging level for jbd2"); 59 #endif 60 61 EXPORT_SYMBOL(jbd2_journal_extend); 62 EXPORT_SYMBOL(jbd2_journal_stop); 63 EXPORT_SYMBOL(jbd2_journal_lock_updates); 64 EXPORT_SYMBOL(jbd2_journal_unlock_updates); 65 EXPORT_SYMBOL(jbd2_journal_get_write_access); 66 EXPORT_SYMBOL(jbd2_journal_get_create_access); 67 EXPORT_SYMBOL(jbd2_journal_get_undo_access); 68 EXPORT_SYMBOL(jbd2_journal_set_triggers); 69 EXPORT_SYMBOL(jbd2_journal_dirty_metadata); 70 EXPORT_SYMBOL(jbd2_journal_forget); 71 #if 0 72 EXPORT_SYMBOL(journal_sync_buffer); 73 #endif 74 EXPORT_SYMBOL(jbd2_journal_flush); 75 EXPORT_SYMBOL(jbd2_journal_revoke); 76 77 EXPORT_SYMBOL(jbd2_journal_init_dev); 78 EXPORT_SYMBOL(jbd2_journal_init_inode); 79 EXPORT_SYMBOL(jbd2_journal_check_used_features); 80 EXPORT_SYMBOL(jbd2_journal_check_available_features); 81 EXPORT_SYMBOL(jbd2_journal_set_features); 82 EXPORT_SYMBOL(jbd2_journal_load); 83 EXPORT_SYMBOL(jbd2_journal_destroy); 84 EXPORT_SYMBOL(jbd2_journal_abort); 85 EXPORT_SYMBOL(jbd2_journal_errno); 86 EXPORT_SYMBOL(jbd2_journal_ack_err); 87 EXPORT_SYMBOL(jbd2_journal_clear_err); 88 EXPORT_SYMBOL(jbd2_log_wait_commit); 89 EXPORT_SYMBOL(jbd2_log_start_commit); 90 EXPORT_SYMBOL(jbd2_journal_start_commit); 91 EXPORT_SYMBOL(jbd2_journal_force_commit_nested); 92 EXPORT_SYMBOL(jbd2_journal_wipe); 93 EXPORT_SYMBOL(jbd2_journal_blocks_per_page); 94 EXPORT_SYMBOL(jbd2_journal_invalidatepage); 95 EXPORT_SYMBOL(jbd2_journal_try_to_free_buffers); 96 EXPORT_SYMBOL(jbd2_journal_force_commit); 97 EXPORT_SYMBOL(jbd2_journal_file_inode); 98 EXPORT_SYMBOL(jbd2_journal_init_jbd_inode); 99 EXPORT_SYMBOL(jbd2_journal_release_jbd_inode); 100 EXPORT_SYMBOL(jbd2_journal_begin_ordered_truncate); 101 EXPORT_SYMBOL(jbd2_inode_cache); 102 103 static void __journal_abort_soft (journal_t *journal, int errno); 104 static int jbd2_journal_create_slab(size_t slab_size); 105 106 #ifdef CONFIG_JBD2_DEBUG 107 void __jbd2_debug(int level, const char *file, const char *func, 108 unsigned int line, const char *fmt, ...) 109 { 110 struct va_format vaf; 111 va_list args; 112 113 if (level > jbd2_journal_enable_debug) 114 return; 115 va_start(args, fmt); 116 vaf.fmt = fmt; 117 vaf.va = &args; 118 printk(KERN_DEBUG "%s: (%s, %u): %pV\n", file, func, line, &vaf); 119 va_end(args); 120 } 121 EXPORT_SYMBOL(__jbd2_debug); 122 #endif 123 124 /* Checksumming functions */ 125 static int jbd2_verify_csum_type(journal_t *j, journal_superblock_t *sb) 126 { 127 if (!jbd2_journal_has_csum_v2or3_feature(j)) 128 return 1; 129 130 return sb->s_checksum_type == JBD2_CRC32C_CHKSUM; 131 } 132 133 static __be32 jbd2_superblock_csum(journal_t *j, journal_superblock_t *sb) 134 { 135 __u32 csum; 136 __be32 old_csum; 137 138 old_csum = sb->s_checksum; 139 sb->s_checksum = 0; 140 csum = jbd2_chksum(j, ~0, (char *)sb, sizeof(journal_superblock_t)); 141 sb->s_checksum = old_csum; 142 143 return cpu_to_be32(csum); 144 } 145 146 static int jbd2_superblock_csum_verify(journal_t *j, journal_superblock_t *sb) 147 { 148 if (!jbd2_journal_has_csum_v2or3(j)) 149 return 1; 150 151 return sb->s_checksum == jbd2_superblock_csum(j, sb); 152 } 153 154 static void jbd2_superblock_csum_set(journal_t *j, journal_superblock_t *sb) 155 { 156 if (!jbd2_journal_has_csum_v2or3(j)) 157 return; 158 159 sb->s_checksum = jbd2_superblock_csum(j, sb); 160 } 161 162 /* 163 * Helper function used to manage commit timeouts 164 */ 165 166 static void commit_timeout(unsigned long __data) 167 { 168 struct task_struct * p = (struct task_struct *) __data; 169 170 wake_up_process(p); 171 } 172 173 /* 174 * kjournald2: The main thread function used to manage a logging device 175 * journal. 176 * 177 * This kernel thread is responsible for two things: 178 * 179 * 1) COMMIT: Every so often we need to commit the current state of the 180 * filesystem to disk. The journal thread is responsible for writing 181 * all of the metadata buffers to disk. 182 * 183 * 2) CHECKPOINT: We cannot reuse a used section of the log file until all 184 * of the data in that part of the log has been rewritten elsewhere on 185 * the disk. Flushing these old buffers to reclaim space in the log is 186 * known as checkpointing, and this thread is responsible for that job. 187 */ 188 189 static int kjournald2(void *arg) 190 { 191 journal_t *journal = arg; 192 transaction_t *transaction; 193 194 /* 195 * Set up an interval timer which can be used to trigger a commit wakeup 196 * after the commit interval expires 197 */ 198 setup_timer(&journal->j_commit_timer, commit_timeout, 199 (unsigned long)current); 200 201 set_freezable(); 202 203 /* Record that the journal thread is running */ 204 journal->j_task = current; 205 wake_up(&journal->j_wait_done_commit); 206 207 /* 208 * And now, wait forever for commit wakeup events. 209 */ 210 write_lock(&journal->j_state_lock); 211 212 loop: 213 if (journal->j_flags & JBD2_UNMOUNT) 214 goto end_loop; 215 216 jbd_debug(1, "commit_sequence=%d, commit_request=%d\n", 217 journal->j_commit_sequence, journal->j_commit_request); 218 219 if (journal->j_commit_sequence != journal->j_commit_request) { 220 jbd_debug(1, "OK, requests differ\n"); 221 write_unlock(&journal->j_state_lock); 222 del_timer_sync(&journal->j_commit_timer); 223 jbd2_journal_commit_transaction(journal); 224 write_lock(&journal->j_state_lock); 225 goto loop; 226 } 227 228 wake_up(&journal->j_wait_done_commit); 229 if (freezing(current)) { 230 /* 231 * The simpler the better. Flushing journal isn't a 232 * good idea, because that depends on threads that may 233 * be already stopped. 234 */ 235 jbd_debug(1, "Now suspending kjournald2\n"); 236 write_unlock(&journal->j_state_lock); 237 try_to_freeze(); 238 write_lock(&journal->j_state_lock); 239 } else { 240 /* 241 * We assume on resume that commits are already there, 242 * so we don't sleep 243 */ 244 DEFINE_WAIT(wait); 245 int should_sleep = 1; 246 247 prepare_to_wait(&journal->j_wait_commit, &wait, 248 TASK_INTERRUPTIBLE); 249 if (journal->j_commit_sequence != journal->j_commit_request) 250 should_sleep = 0; 251 transaction = journal->j_running_transaction; 252 if (transaction && time_after_eq(jiffies, 253 transaction->t_expires)) 254 should_sleep = 0; 255 if (journal->j_flags & JBD2_UNMOUNT) 256 should_sleep = 0; 257 if (should_sleep) { 258 write_unlock(&journal->j_state_lock); 259 schedule(); 260 write_lock(&journal->j_state_lock); 261 } 262 finish_wait(&journal->j_wait_commit, &wait); 263 } 264 265 jbd_debug(1, "kjournald2 wakes\n"); 266 267 /* 268 * Were we woken up by a commit wakeup event? 269 */ 270 transaction = journal->j_running_transaction; 271 if (transaction && time_after_eq(jiffies, transaction->t_expires)) { 272 journal->j_commit_request = transaction->t_tid; 273 jbd_debug(1, "woke because of timeout\n"); 274 } 275 goto loop; 276 277 end_loop: 278 write_unlock(&journal->j_state_lock); 279 del_timer_sync(&journal->j_commit_timer); 280 journal->j_task = NULL; 281 wake_up(&journal->j_wait_done_commit); 282 jbd_debug(1, "Journal thread exiting.\n"); 283 return 0; 284 } 285 286 static int jbd2_journal_start_thread(journal_t *journal) 287 { 288 struct task_struct *t; 289 290 t = kthread_run(kjournald2, journal, "jbd2/%s", 291 journal->j_devname); 292 if (IS_ERR(t)) 293 return PTR_ERR(t); 294 295 wait_event(journal->j_wait_done_commit, journal->j_task != NULL); 296 return 0; 297 } 298 299 static void journal_kill_thread(journal_t *journal) 300 { 301 write_lock(&journal->j_state_lock); 302 journal->j_flags |= JBD2_UNMOUNT; 303 304 while (journal->j_task) { 305 write_unlock(&journal->j_state_lock); 306 wake_up(&journal->j_wait_commit); 307 wait_event(journal->j_wait_done_commit, journal->j_task == NULL); 308 write_lock(&journal->j_state_lock); 309 } 310 write_unlock(&journal->j_state_lock); 311 } 312 313 /* 314 * jbd2_journal_write_metadata_buffer: write a metadata buffer to the journal. 315 * 316 * Writes a metadata buffer to a given disk block. The actual IO is not 317 * performed but a new buffer_head is constructed which labels the data 318 * to be written with the correct destination disk block. 319 * 320 * Any magic-number escaping which needs to be done will cause a 321 * copy-out here. If the buffer happens to start with the 322 * JBD2_MAGIC_NUMBER, then we can't write it to the log directly: the 323 * magic number is only written to the log for descripter blocks. In 324 * this case, we copy the data and replace the first word with 0, and we 325 * return a result code which indicates that this buffer needs to be 326 * marked as an escaped buffer in the corresponding log descriptor 327 * block. The missing word can then be restored when the block is read 328 * during recovery. 329 * 330 * If the source buffer has already been modified by a new transaction 331 * since we took the last commit snapshot, we use the frozen copy of 332 * that data for IO. If we end up using the existing buffer_head's data 333 * for the write, then we have to make sure nobody modifies it while the 334 * IO is in progress. do_get_write_access() handles this. 335 * 336 * The function returns a pointer to the buffer_head to be used for IO. 337 * 338 * 339 * Return value: 340 * <0: Error 341 * >=0: Finished OK 342 * 343 * On success: 344 * Bit 0 set == escape performed on the data 345 * Bit 1 set == buffer copy-out performed (kfree the data after IO) 346 */ 347 348 int jbd2_journal_write_metadata_buffer(transaction_t *transaction, 349 struct journal_head *jh_in, 350 struct buffer_head **bh_out, 351 sector_t blocknr) 352 { 353 int need_copy_out = 0; 354 int done_copy_out = 0; 355 int do_escape = 0; 356 char *mapped_data; 357 struct buffer_head *new_bh; 358 struct page *new_page; 359 unsigned int new_offset; 360 struct buffer_head *bh_in = jh2bh(jh_in); 361 journal_t *journal = transaction->t_journal; 362 363 /* 364 * The buffer really shouldn't be locked: only the current committing 365 * transaction is allowed to write it, so nobody else is allowed 366 * to do any IO. 367 * 368 * akpm: except if we're journalling data, and write() output is 369 * also part of a shared mapping, and another thread has 370 * decided to launch a writepage() against this buffer. 371 */ 372 J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in)); 373 374 new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL); 375 376 /* keep subsequent assertions sane */ 377 atomic_set(&new_bh->b_count, 1); 378 379 jbd_lock_bh_state(bh_in); 380 repeat: 381 /* 382 * If a new transaction has already done a buffer copy-out, then 383 * we use that version of the data for the commit. 384 */ 385 if (jh_in->b_frozen_data) { 386 done_copy_out = 1; 387 new_page = virt_to_page(jh_in->b_frozen_data); 388 new_offset = offset_in_page(jh_in->b_frozen_data); 389 } else { 390 new_page = jh2bh(jh_in)->b_page; 391 new_offset = offset_in_page(jh2bh(jh_in)->b_data); 392 } 393 394 mapped_data = kmap_atomic(new_page); 395 /* 396 * Fire data frozen trigger if data already wasn't frozen. Do this 397 * before checking for escaping, as the trigger may modify the magic 398 * offset. If a copy-out happens afterwards, it will have the correct 399 * data in the buffer. 400 */ 401 if (!done_copy_out) 402 jbd2_buffer_frozen_trigger(jh_in, mapped_data + new_offset, 403 jh_in->b_triggers); 404 405 /* 406 * Check for escaping 407 */ 408 if (*((__be32 *)(mapped_data + new_offset)) == 409 cpu_to_be32(JBD2_MAGIC_NUMBER)) { 410 need_copy_out = 1; 411 do_escape = 1; 412 } 413 kunmap_atomic(mapped_data); 414 415 /* 416 * Do we need to do a data copy? 417 */ 418 if (need_copy_out && !done_copy_out) { 419 char *tmp; 420 421 jbd_unlock_bh_state(bh_in); 422 tmp = jbd2_alloc(bh_in->b_size, GFP_NOFS); 423 if (!tmp) { 424 brelse(new_bh); 425 return -ENOMEM; 426 } 427 jbd_lock_bh_state(bh_in); 428 if (jh_in->b_frozen_data) { 429 jbd2_free(tmp, bh_in->b_size); 430 goto repeat; 431 } 432 433 jh_in->b_frozen_data = tmp; 434 mapped_data = kmap_atomic(new_page); 435 memcpy(tmp, mapped_data + new_offset, bh_in->b_size); 436 kunmap_atomic(mapped_data); 437 438 new_page = virt_to_page(tmp); 439 new_offset = offset_in_page(tmp); 440 done_copy_out = 1; 441 442 /* 443 * This isn't strictly necessary, as we're using frozen 444 * data for the escaping, but it keeps consistency with 445 * b_frozen_data usage. 446 */ 447 jh_in->b_frozen_triggers = jh_in->b_triggers; 448 } 449 450 /* 451 * Did we need to do an escaping? Now we've done all the 452 * copying, we can finally do so. 453 */ 454 if (do_escape) { 455 mapped_data = kmap_atomic(new_page); 456 *((unsigned int *)(mapped_data + new_offset)) = 0; 457 kunmap_atomic(mapped_data); 458 } 459 460 set_bh_page(new_bh, new_page, new_offset); 461 new_bh->b_size = bh_in->b_size; 462 new_bh->b_bdev = journal->j_dev; 463 new_bh->b_blocknr = blocknr; 464 new_bh->b_private = bh_in; 465 set_buffer_mapped(new_bh); 466 set_buffer_dirty(new_bh); 467 468 *bh_out = new_bh; 469 470 /* 471 * The to-be-written buffer needs to get moved to the io queue, 472 * and the original buffer whose contents we are shadowing or 473 * copying is moved to the transaction's shadow queue. 474 */ 475 JBUFFER_TRACE(jh_in, "file as BJ_Shadow"); 476 spin_lock(&journal->j_list_lock); 477 __jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow); 478 spin_unlock(&journal->j_list_lock); 479 set_buffer_shadow(bh_in); 480 jbd_unlock_bh_state(bh_in); 481 482 return do_escape | (done_copy_out << 1); 483 } 484 485 /* 486 * Allocation code for the journal file. Manage the space left in the 487 * journal, so that we can begin checkpointing when appropriate. 488 */ 489 490 /* 491 * Called with j_state_lock locked for writing. 492 * Returns true if a transaction commit was started. 493 */ 494 int __jbd2_log_start_commit(journal_t *journal, tid_t target) 495 { 496 /* Return if the txn has already requested to be committed */ 497 if (journal->j_commit_request == target) 498 return 0; 499 500 /* 501 * The only transaction we can possibly wait upon is the 502 * currently running transaction (if it exists). Otherwise, 503 * the target tid must be an old one. 504 */ 505 if (journal->j_running_transaction && 506 journal->j_running_transaction->t_tid == target) { 507 /* 508 * We want a new commit: OK, mark the request and wakeup the 509 * commit thread. We do _not_ do the commit ourselves. 510 */ 511 512 journal->j_commit_request = target; 513 jbd_debug(1, "JBD2: requesting commit %d/%d\n", 514 journal->j_commit_request, 515 journal->j_commit_sequence); 516 journal->j_running_transaction->t_requested = jiffies; 517 wake_up(&journal->j_wait_commit); 518 return 1; 519 } else if (!tid_geq(journal->j_commit_request, target)) 520 /* This should never happen, but if it does, preserve 521 the evidence before kjournald goes into a loop and 522 increments j_commit_sequence beyond all recognition. */ 523 WARN_ONCE(1, "JBD2: bad log_start_commit: %u %u %u %u\n", 524 journal->j_commit_request, 525 journal->j_commit_sequence, 526 target, journal->j_running_transaction ? 527 journal->j_running_transaction->t_tid : 0); 528 return 0; 529 } 530 531 int jbd2_log_start_commit(journal_t *journal, tid_t tid) 532 { 533 int ret; 534 535 write_lock(&journal->j_state_lock); 536 ret = __jbd2_log_start_commit(journal, tid); 537 write_unlock(&journal->j_state_lock); 538 return ret; 539 } 540 541 /* 542 * Force and wait any uncommitted transactions. We can only force the running 543 * transaction if we don't have an active handle, otherwise, we will deadlock. 544 * Returns: <0 in case of error, 545 * 0 if nothing to commit, 546 * 1 if transaction was successfully committed. 547 */ 548 static int __jbd2_journal_force_commit(journal_t *journal) 549 { 550 transaction_t *transaction = NULL; 551 tid_t tid; 552 int need_to_start = 0, ret = 0; 553 554 read_lock(&journal->j_state_lock); 555 if (journal->j_running_transaction && !current->journal_info) { 556 transaction = journal->j_running_transaction; 557 if (!tid_geq(journal->j_commit_request, transaction->t_tid)) 558 need_to_start = 1; 559 } else if (journal->j_committing_transaction) 560 transaction = journal->j_committing_transaction; 561 562 if (!transaction) { 563 /* Nothing to commit */ 564 read_unlock(&journal->j_state_lock); 565 return 0; 566 } 567 tid = transaction->t_tid; 568 read_unlock(&journal->j_state_lock); 569 if (need_to_start) 570 jbd2_log_start_commit(journal, tid); 571 ret = jbd2_log_wait_commit(journal, tid); 572 if (!ret) 573 ret = 1; 574 575 return ret; 576 } 577 578 /** 579 * Force and wait upon a commit if the calling process is not within 580 * transaction. This is used for forcing out undo-protected data which contains 581 * bitmaps, when the fs is running out of space. 582 * 583 * @journal: journal to force 584 * Returns true if progress was made. 585 */ 586 int jbd2_journal_force_commit_nested(journal_t *journal) 587 { 588 int ret; 589 590 ret = __jbd2_journal_force_commit(journal); 591 return ret > 0; 592 } 593 594 /** 595 * int journal_force_commit() - force any uncommitted transactions 596 * @journal: journal to force 597 * 598 * Caller want unconditional commit. We can only force the running transaction 599 * if we don't have an active handle, otherwise, we will deadlock. 600 */ 601 int jbd2_journal_force_commit(journal_t *journal) 602 { 603 int ret; 604 605 J_ASSERT(!current->journal_info); 606 ret = __jbd2_journal_force_commit(journal); 607 if (ret > 0) 608 ret = 0; 609 return ret; 610 } 611 612 /* 613 * Start a commit of the current running transaction (if any). Returns true 614 * if a transaction is going to be committed (or is currently already 615 * committing), and fills its tid in at *ptid 616 */ 617 int jbd2_journal_start_commit(journal_t *journal, tid_t *ptid) 618 { 619 int ret = 0; 620 621 write_lock(&journal->j_state_lock); 622 if (journal->j_running_transaction) { 623 tid_t tid = journal->j_running_transaction->t_tid; 624 625 __jbd2_log_start_commit(journal, tid); 626 /* There's a running transaction and we've just made sure 627 * it's commit has been scheduled. */ 628 if (ptid) 629 *ptid = tid; 630 ret = 1; 631 } else if (journal->j_committing_transaction) { 632 /* 633 * If commit has been started, then we have to wait for 634 * completion of that transaction. 635 */ 636 if (ptid) 637 *ptid = journal->j_committing_transaction->t_tid; 638 ret = 1; 639 } 640 write_unlock(&journal->j_state_lock); 641 return ret; 642 } 643 644 /* 645 * Return 1 if a given transaction has not yet sent barrier request 646 * connected with a transaction commit. If 0 is returned, transaction 647 * may or may not have sent the barrier. Used to avoid sending barrier 648 * twice in common cases. 649 */ 650 int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid) 651 { 652 int ret = 0; 653 transaction_t *commit_trans; 654 655 if (!(journal->j_flags & JBD2_BARRIER)) 656 return 0; 657 read_lock(&journal->j_state_lock); 658 /* Transaction already committed? */ 659 if (tid_geq(journal->j_commit_sequence, tid)) 660 goto out; 661 commit_trans = journal->j_committing_transaction; 662 if (!commit_trans || commit_trans->t_tid != tid) { 663 ret = 1; 664 goto out; 665 } 666 /* 667 * Transaction is being committed and we already proceeded to 668 * submitting a flush to fs partition? 669 */ 670 if (journal->j_fs_dev != journal->j_dev) { 671 if (!commit_trans->t_need_data_flush || 672 commit_trans->t_state >= T_COMMIT_DFLUSH) 673 goto out; 674 } else { 675 if (commit_trans->t_state >= T_COMMIT_JFLUSH) 676 goto out; 677 } 678 ret = 1; 679 out: 680 read_unlock(&journal->j_state_lock); 681 return ret; 682 } 683 EXPORT_SYMBOL(jbd2_trans_will_send_data_barrier); 684 685 /* 686 * Wait for a specified commit to complete. 687 * The caller may not hold the journal lock. 688 */ 689 int jbd2_log_wait_commit(journal_t *journal, tid_t tid) 690 { 691 int err = 0; 692 693 read_lock(&journal->j_state_lock); 694 #ifdef CONFIG_JBD2_DEBUG 695 if (!tid_geq(journal->j_commit_request, tid)) { 696 printk(KERN_ERR 697 "%s: error: j_commit_request=%d, tid=%d\n", 698 __func__, journal->j_commit_request, tid); 699 } 700 #endif 701 while (tid_gt(tid, journal->j_commit_sequence)) { 702 jbd_debug(1, "JBD2: want %d, j_commit_sequence=%d\n", 703 tid, journal->j_commit_sequence); 704 read_unlock(&journal->j_state_lock); 705 wake_up(&journal->j_wait_commit); 706 wait_event(journal->j_wait_done_commit, 707 !tid_gt(tid, journal->j_commit_sequence)); 708 read_lock(&journal->j_state_lock); 709 } 710 read_unlock(&journal->j_state_lock); 711 712 if (unlikely(is_journal_aborted(journal))) 713 err = -EIO; 714 return err; 715 } 716 717 /* 718 * When this function returns the transaction corresponding to tid 719 * will be completed. If the transaction has currently running, start 720 * committing that transaction before waiting for it to complete. If 721 * the transaction id is stale, it is by definition already completed, 722 * so just return SUCCESS. 723 */ 724 int jbd2_complete_transaction(journal_t *journal, tid_t tid) 725 { 726 int need_to_wait = 1; 727 728 read_lock(&journal->j_state_lock); 729 if (journal->j_running_transaction && 730 journal->j_running_transaction->t_tid == tid) { 731 if (journal->j_commit_request != tid) { 732 /* transaction not yet started, so request it */ 733 read_unlock(&journal->j_state_lock); 734 jbd2_log_start_commit(journal, tid); 735 goto wait_commit; 736 } 737 } else if (!(journal->j_committing_transaction && 738 journal->j_committing_transaction->t_tid == tid)) 739 need_to_wait = 0; 740 read_unlock(&journal->j_state_lock); 741 if (!need_to_wait) 742 return 0; 743 wait_commit: 744 return jbd2_log_wait_commit(journal, tid); 745 } 746 EXPORT_SYMBOL(jbd2_complete_transaction); 747 748 /* 749 * Log buffer allocation routines: 750 */ 751 752 int jbd2_journal_next_log_block(journal_t *journal, unsigned long long *retp) 753 { 754 unsigned long blocknr; 755 756 write_lock(&journal->j_state_lock); 757 J_ASSERT(journal->j_free > 1); 758 759 blocknr = journal->j_head; 760 journal->j_head++; 761 journal->j_free--; 762 if (journal->j_head == journal->j_last) 763 journal->j_head = journal->j_first; 764 write_unlock(&journal->j_state_lock); 765 return jbd2_journal_bmap(journal, blocknr, retp); 766 } 767 768 /* 769 * Conversion of logical to physical block numbers for the journal 770 * 771 * On external journals the journal blocks are identity-mapped, so 772 * this is a no-op. If needed, we can use j_blk_offset - everything is 773 * ready. 774 */ 775 int jbd2_journal_bmap(journal_t *journal, unsigned long blocknr, 776 unsigned long long *retp) 777 { 778 int err = 0; 779 unsigned long long ret; 780 781 if (journal->j_inode) { 782 ret = bmap(journal->j_inode, blocknr); 783 if (ret) 784 *retp = ret; 785 else { 786 printk(KERN_ALERT "%s: journal block not found " 787 "at offset %lu on %s\n", 788 __func__, blocknr, journal->j_devname); 789 err = -EIO; 790 __journal_abort_soft(journal, err); 791 } 792 } else { 793 *retp = blocknr; /* +journal->j_blk_offset */ 794 } 795 return err; 796 } 797 798 /* 799 * We play buffer_head aliasing tricks to write data/metadata blocks to 800 * the journal without copying their contents, but for journal 801 * descriptor blocks we do need to generate bona fide buffers. 802 * 803 * After the caller of jbd2_journal_get_descriptor_buffer() has finished modifying 804 * the buffer's contents they really should run flush_dcache_page(bh->b_page). 805 * But we don't bother doing that, so there will be coherency problems with 806 * mmaps of blockdevs which hold live JBD-controlled filesystems. 807 */ 808 struct buffer_head * 809 jbd2_journal_get_descriptor_buffer(transaction_t *transaction, int type) 810 { 811 journal_t *journal = transaction->t_journal; 812 struct buffer_head *bh; 813 unsigned long long blocknr; 814 journal_header_t *header; 815 int err; 816 817 err = jbd2_journal_next_log_block(journal, &blocknr); 818 819 if (err) 820 return NULL; 821 822 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); 823 if (!bh) 824 return NULL; 825 lock_buffer(bh); 826 memset(bh->b_data, 0, journal->j_blocksize); 827 header = (journal_header_t *)bh->b_data; 828 header->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER); 829 header->h_blocktype = cpu_to_be32(type); 830 header->h_sequence = cpu_to_be32(transaction->t_tid); 831 set_buffer_uptodate(bh); 832 unlock_buffer(bh); 833 BUFFER_TRACE(bh, "return this buffer"); 834 return bh; 835 } 836 837 void jbd2_descriptor_block_csum_set(journal_t *j, struct buffer_head *bh) 838 { 839 struct jbd2_journal_block_tail *tail; 840 __u32 csum; 841 842 if (!jbd2_journal_has_csum_v2or3(j)) 843 return; 844 845 tail = (struct jbd2_journal_block_tail *)(bh->b_data + j->j_blocksize - 846 sizeof(struct jbd2_journal_block_tail)); 847 tail->t_checksum = 0; 848 csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize); 849 tail->t_checksum = cpu_to_be32(csum); 850 } 851 852 /* 853 * Return tid of the oldest transaction in the journal and block in the journal 854 * where the transaction starts. 855 * 856 * If the journal is now empty, return which will be the next transaction ID 857 * we will write and where will that transaction start. 858 * 859 * The return value is 0 if journal tail cannot be pushed any further, 1 if 860 * it can. 861 */ 862 int jbd2_journal_get_log_tail(journal_t *journal, tid_t *tid, 863 unsigned long *block) 864 { 865 transaction_t *transaction; 866 int ret; 867 868 read_lock(&journal->j_state_lock); 869 spin_lock(&journal->j_list_lock); 870 transaction = journal->j_checkpoint_transactions; 871 if (transaction) { 872 *tid = transaction->t_tid; 873 *block = transaction->t_log_start; 874 } else if ((transaction = journal->j_committing_transaction) != NULL) { 875 *tid = transaction->t_tid; 876 *block = transaction->t_log_start; 877 } else if ((transaction = journal->j_running_transaction) != NULL) { 878 *tid = transaction->t_tid; 879 *block = journal->j_head; 880 } else { 881 *tid = journal->j_transaction_sequence; 882 *block = journal->j_head; 883 } 884 ret = tid_gt(*tid, journal->j_tail_sequence); 885 spin_unlock(&journal->j_list_lock); 886 read_unlock(&journal->j_state_lock); 887 888 return ret; 889 } 890 891 /* 892 * Update information in journal structure and in on disk journal superblock 893 * about log tail. This function does not check whether information passed in 894 * really pushes log tail further. It's responsibility of the caller to make 895 * sure provided log tail information is valid (e.g. by holding 896 * j_checkpoint_mutex all the time between computing log tail and calling this 897 * function as is the case with jbd2_cleanup_journal_tail()). 898 * 899 * Requires j_checkpoint_mutex 900 */ 901 int __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block) 902 { 903 unsigned long freed; 904 int ret; 905 906 BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex)); 907 908 /* 909 * We cannot afford for write to remain in drive's caches since as 910 * soon as we update j_tail, next transaction can start reusing journal 911 * space and if we lose sb update during power failure we'd replay 912 * old transaction with possibly newly overwritten data. 913 */ 914 ret = jbd2_journal_update_sb_log_tail(journal, tid, block, WRITE_FUA); 915 if (ret) 916 goto out; 917 918 write_lock(&journal->j_state_lock); 919 freed = block - journal->j_tail; 920 if (block < journal->j_tail) 921 freed += journal->j_last - journal->j_first; 922 923 trace_jbd2_update_log_tail(journal, tid, block, freed); 924 jbd_debug(1, 925 "Cleaning journal tail from %d to %d (offset %lu), " 926 "freeing %lu\n", 927 journal->j_tail_sequence, tid, block, freed); 928 929 journal->j_free += freed; 930 journal->j_tail_sequence = tid; 931 journal->j_tail = block; 932 write_unlock(&journal->j_state_lock); 933 934 out: 935 return ret; 936 } 937 938 /* 939 * This is a variaon of __jbd2_update_log_tail which checks for validity of 940 * provided log tail and locks j_checkpoint_mutex. So it is safe against races 941 * with other threads updating log tail. 942 */ 943 void jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block) 944 { 945 mutex_lock(&journal->j_checkpoint_mutex); 946 if (tid_gt(tid, journal->j_tail_sequence)) 947 __jbd2_update_log_tail(journal, tid, block); 948 mutex_unlock(&journal->j_checkpoint_mutex); 949 } 950 951 struct jbd2_stats_proc_session { 952 journal_t *journal; 953 struct transaction_stats_s *stats; 954 int start; 955 int max; 956 }; 957 958 static void *jbd2_seq_info_start(struct seq_file *seq, loff_t *pos) 959 { 960 return *pos ? NULL : SEQ_START_TOKEN; 961 } 962 963 static void *jbd2_seq_info_next(struct seq_file *seq, void *v, loff_t *pos) 964 { 965 return NULL; 966 } 967 968 static int jbd2_seq_info_show(struct seq_file *seq, void *v) 969 { 970 struct jbd2_stats_proc_session *s = seq->private; 971 972 if (v != SEQ_START_TOKEN) 973 return 0; 974 seq_printf(seq, "%lu transactions (%lu requested), " 975 "each up to %u blocks\n", 976 s->stats->ts_tid, s->stats->ts_requested, 977 s->journal->j_max_transaction_buffers); 978 if (s->stats->ts_tid == 0) 979 return 0; 980 seq_printf(seq, "average: \n %ums waiting for transaction\n", 981 jiffies_to_msecs(s->stats->run.rs_wait / s->stats->ts_tid)); 982 seq_printf(seq, " %ums request delay\n", 983 (s->stats->ts_requested == 0) ? 0 : 984 jiffies_to_msecs(s->stats->run.rs_request_delay / 985 s->stats->ts_requested)); 986 seq_printf(seq, " %ums running transaction\n", 987 jiffies_to_msecs(s->stats->run.rs_running / s->stats->ts_tid)); 988 seq_printf(seq, " %ums transaction was being locked\n", 989 jiffies_to_msecs(s->stats->run.rs_locked / s->stats->ts_tid)); 990 seq_printf(seq, " %ums flushing data (in ordered mode)\n", 991 jiffies_to_msecs(s->stats->run.rs_flushing / s->stats->ts_tid)); 992 seq_printf(seq, " %ums logging transaction\n", 993 jiffies_to_msecs(s->stats->run.rs_logging / s->stats->ts_tid)); 994 seq_printf(seq, " %lluus average transaction commit time\n", 995 div_u64(s->journal->j_average_commit_time, 1000)); 996 seq_printf(seq, " %lu handles per transaction\n", 997 s->stats->run.rs_handle_count / s->stats->ts_tid); 998 seq_printf(seq, " %lu blocks per transaction\n", 999 s->stats->run.rs_blocks / s->stats->ts_tid); 1000 seq_printf(seq, " %lu logged blocks per transaction\n", 1001 s->stats->run.rs_blocks_logged / s->stats->ts_tid); 1002 return 0; 1003 } 1004 1005 static void jbd2_seq_info_stop(struct seq_file *seq, void *v) 1006 { 1007 } 1008 1009 static const struct seq_operations jbd2_seq_info_ops = { 1010 .start = jbd2_seq_info_start, 1011 .next = jbd2_seq_info_next, 1012 .stop = jbd2_seq_info_stop, 1013 .show = jbd2_seq_info_show, 1014 }; 1015 1016 static int jbd2_seq_info_open(struct inode *inode, struct file *file) 1017 { 1018 journal_t *journal = PDE_DATA(inode); 1019 struct jbd2_stats_proc_session *s; 1020 int rc, size; 1021 1022 s = kmalloc(sizeof(*s), GFP_KERNEL); 1023 if (s == NULL) 1024 return -ENOMEM; 1025 size = sizeof(struct transaction_stats_s); 1026 s->stats = kmalloc(size, GFP_KERNEL); 1027 if (s->stats == NULL) { 1028 kfree(s); 1029 return -ENOMEM; 1030 } 1031 spin_lock(&journal->j_history_lock); 1032 memcpy(s->stats, &journal->j_stats, size); 1033 s->journal = journal; 1034 spin_unlock(&journal->j_history_lock); 1035 1036 rc = seq_open(file, &jbd2_seq_info_ops); 1037 if (rc == 0) { 1038 struct seq_file *m = file->private_data; 1039 m->private = s; 1040 } else { 1041 kfree(s->stats); 1042 kfree(s); 1043 } 1044 return rc; 1045 1046 } 1047 1048 static int jbd2_seq_info_release(struct inode *inode, struct file *file) 1049 { 1050 struct seq_file *seq = file->private_data; 1051 struct jbd2_stats_proc_session *s = seq->private; 1052 kfree(s->stats); 1053 kfree(s); 1054 return seq_release(inode, file); 1055 } 1056 1057 static const struct file_operations jbd2_seq_info_fops = { 1058 .owner = THIS_MODULE, 1059 .open = jbd2_seq_info_open, 1060 .read = seq_read, 1061 .llseek = seq_lseek, 1062 .release = jbd2_seq_info_release, 1063 }; 1064 1065 static struct proc_dir_entry *proc_jbd2_stats; 1066 1067 static void jbd2_stats_proc_init(journal_t *journal) 1068 { 1069 journal->j_proc_entry = proc_mkdir(journal->j_devname, proc_jbd2_stats); 1070 if (journal->j_proc_entry) { 1071 proc_create_data("info", S_IRUGO, journal->j_proc_entry, 1072 &jbd2_seq_info_fops, journal); 1073 } 1074 } 1075 1076 static void jbd2_stats_proc_exit(journal_t *journal) 1077 { 1078 remove_proc_entry("info", journal->j_proc_entry); 1079 remove_proc_entry(journal->j_devname, proc_jbd2_stats); 1080 } 1081 1082 /* 1083 * Management for journal control blocks: functions to create and 1084 * destroy journal_t structures, and to initialise and read existing 1085 * journal blocks from disk. */ 1086 1087 /* First: create and setup a journal_t object in memory. We initialise 1088 * very few fields yet: that has to wait until we have created the 1089 * journal structures from from scratch, or loaded them from disk. */ 1090 1091 static journal_t * journal_init_common (void) 1092 { 1093 journal_t *journal; 1094 int err; 1095 1096 journal = kzalloc(sizeof(*journal), GFP_KERNEL); 1097 if (!journal) 1098 return NULL; 1099 1100 init_waitqueue_head(&journal->j_wait_transaction_locked); 1101 init_waitqueue_head(&journal->j_wait_done_commit); 1102 init_waitqueue_head(&journal->j_wait_commit); 1103 init_waitqueue_head(&journal->j_wait_updates); 1104 init_waitqueue_head(&journal->j_wait_reserved); 1105 mutex_init(&journal->j_barrier); 1106 mutex_init(&journal->j_checkpoint_mutex); 1107 spin_lock_init(&journal->j_revoke_lock); 1108 spin_lock_init(&journal->j_list_lock); 1109 rwlock_init(&journal->j_state_lock); 1110 1111 journal->j_commit_interval = (HZ * JBD2_DEFAULT_MAX_COMMIT_AGE); 1112 journal->j_min_batch_time = 0; 1113 journal->j_max_batch_time = 15000; /* 15ms */ 1114 atomic_set(&journal->j_reserved_credits, 0); 1115 1116 /* The journal is marked for error until we succeed with recovery! */ 1117 journal->j_flags = JBD2_ABORT; 1118 1119 /* Set up a default-sized revoke table for the new mount. */ 1120 err = jbd2_journal_init_revoke(journal, JOURNAL_REVOKE_DEFAULT_HASH); 1121 if (err) { 1122 kfree(journal); 1123 return NULL; 1124 } 1125 1126 spin_lock_init(&journal->j_history_lock); 1127 1128 return journal; 1129 } 1130 1131 /* jbd2_journal_init_dev and jbd2_journal_init_inode: 1132 * 1133 * Create a journal structure assigned some fixed set of disk blocks to 1134 * the journal. We don't actually touch those disk blocks yet, but we 1135 * need to set up all of the mapping information to tell the journaling 1136 * system where the journal blocks are. 1137 * 1138 */ 1139 1140 /** 1141 * journal_t * jbd2_journal_init_dev() - creates and initialises a journal structure 1142 * @bdev: Block device on which to create the journal 1143 * @fs_dev: Device which hold journalled filesystem for this journal. 1144 * @start: Block nr Start of journal. 1145 * @len: Length of the journal in blocks. 1146 * @blocksize: blocksize of journalling device 1147 * 1148 * Returns: a newly created journal_t * 1149 * 1150 * jbd2_journal_init_dev creates a journal which maps a fixed contiguous 1151 * range of blocks on an arbitrary block device. 1152 * 1153 */ 1154 journal_t * jbd2_journal_init_dev(struct block_device *bdev, 1155 struct block_device *fs_dev, 1156 unsigned long long start, int len, int blocksize) 1157 { 1158 journal_t *journal = journal_init_common(); 1159 struct buffer_head *bh; 1160 int n; 1161 1162 if (!journal) 1163 return NULL; 1164 1165 /* journal descriptor can store up to n blocks -bzzz */ 1166 journal->j_blocksize = blocksize; 1167 journal->j_dev = bdev; 1168 journal->j_fs_dev = fs_dev; 1169 journal->j_blk_offset = start; 1170 journal->j_maxlen = len; 1171 bdevname(journal->j_dev, journal->j_devname); 1172 strreplace(journal->j_devname, '/', '!'); 1173 jbd2_stats_proc_init(journal); 1174 n = journal->j_blocksize / sizeof(journal_block_tag_t); 1175 journal->j_wbufsize = n; 1176 journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL); 1177 if (!journal->j_wbuf) { 1178 printk(KERN_ERR "%s: Can't allocate bhs for commit thread\n", 1179 __func__); 1180 goto out_err; 1181 } 1182 1183 bh = __getblk(journal->j_dev, start, journal->j_blocksize); 1184 if (!bh) { 1185 printk(KERN_ERR 1186 "%s: Cannot get buffer for journal superblock\n", 1187 __func__); 1188 goto out_err; 1189 } 1190 journal->j_sb_buffer = bh; 1191 journal->j_superblock = (journal_superblock_t *)bh->b_data; 1192 1193 return journal; 1194 out_err: 1195 kfree(journal->j_wbuf); 1196 jbd2_stats_proc_exit(journal); 1197 kfree(journal); 1198 return NULL; 1199 } 1200 1201 /** 1202 * journal_t * jbd2_journal_init_inode () - creates a journal which maps to a inode. 1203 * @inode: An inode to create the journal in 1204 * 1205 * jbd2_journal_init_inode creates a journal which maps an on-disk inode as 1206 * the journal. The inode must exist already, must support bmap() and 1207 * must have all data blocks preallocated. 1208 */ 1209 journal_t * jbd2_journal_init_inode (struct inode *inode) 1210 { 1211 struct buffer_head *bh; 1212 journal_t *journal = journal_init_common(); 1213 char *p; 1214 int err; 1215 int n; 1216 unsigned long long blocknr; 1217 1218 if (!journal) 1219 return NULL; 1220 1221 journal->j_dev = journal->j_fs_dev = inode->i_sb->s_bdev; 1222 journal->j_inode = inode; 1223 bdevname(journal->j_dev, journal->j_devname); 1224 p = strreplace(journal->j_devname, '/', '!'); 1225 sprintf(p, "-%lu", journal->j_inode->i_ino); 1226 jbd_debug(1, 1227 "journal %p: inode %s/%ld, size %Ld, bits %d, blksize %ld\n", 1228 journal, inode->i_sb->s_id, inode->i_ino, 1229 (long long) inode->i_size, 1230 inode->i_sb->s_blocksize_bits, inode->i_sb->s_blocksize); 1231 1232 journal->j_maxlen = inode->i_size >> inode->i_sb->s_blocksize_bits; 1233 journal->j_blocksize = inode->i_sb->s_blocksize; 1234 jbd2_stats_proc_init(journal); 1235 1236 /* journal descriptor can store up to n blocks -bzzz */ 1237 n = journal->j_blocksize / sizeof(journal_block_tag_t); 1238 journal->j_wbufsize = n; 1239 journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL); 1240 if (!journal->j_wbuf) { 1241 printk(KERN_ERR "%s: Can't allocate bhs for commit thread\n", 1242 __func__); 1243 goto out_err; 1244 } 1245 1246 err = jbd2_journal_bmap(journal, 0, &blocknr); 1247 /* If that failed, give up */ 1248 if (err) { 1249 printk(KERN_ERR "%s: Cannot locate journal superblock\n", 1250 __func__); 1251 goto out_err; 1252 } 1253 1254 bh = getblk_unmovable(journal->j_dev, blocknr, journal->j_blocksize); 1255 if (!bh) { 1256 printk(KERN_ERR 1257 "%s: Cannot get buffer for journal superblock\n", 1258 __func__); 1259 goto out_err; 1260 } 1261 journal->j_sb_buffer = bh; 1262 journal->j_superblock = (journal_superblock_t *)bh->b_data; 1263 1264 return journal; 1265 out_err: 1266 kfree(journal->j_wbuf); 1267 jbd2_stats_proc_exit(journal); 1268 kfree(journal); 1269 return NULL; 1270 } 1271 1272 /* 1273 * If the journal init or create aborts, we need to mark the journal 1274 * superblock as being NULL to prevent the journal destroy from writing 1275 * back a bogus superblock. 1276 */ 1277 static void journal_fail_superblock (journal_t *journal) 1278 { 1279 struct buffer_head *bh = journal->j_sb_buffer; 1280 brelse(bh); 1281 journal->j_sb_buffer = NULL; 1282 } 1283 1284 /* 1285 * Given a journal_t structure, initialise the various fields for 1286 * startup of a new journaling session. We use this both when creating 1287 * a journal, and after recovering an old journal to reset it for 1288 * subsequent use. 1289 */ 1290 1291 static int journal_reset(journal_t *journal) 1292 { 1293 journal_superblock_t *sb = journal->j_superblock; 1294 unsigned long long first, last; 1295 1296 first = be32_to_cpu(sb->s_first); 1297 last = be32_to_cpu(sb->s_maxlen); 1298 if (first + JBD2_MIN_JOURNAL_BLOCKS > last + 1) { 1299 printk(KERN_ERR "JBD2: Journal too short (blocks %llu-%llu).\n", 1300 first, last); 1301 journal_fail_superblock(journal); 1302 return -EINVAL; 1303 } 1304 1305 journal->j_first = first; 1306 journal->j_last = last; 1307 1308 journal->j_head = first; 1309 journal->j_tail = first; 1310 journal->j_free = last - first; 1311 1312 journal->j_tail_sequence = journal->j_transaction_sequence; 1313 journal->j_commit_sequence = journal->j_transaction_sequence - 1; 1314 journal->j_commit_request = journal->j_commit_sequence; 1315 1316 journal->j_max_transaction_buffers = journal->j_maxlen / 4; 1317 1318 /* 1319 * As a special case, if the on-disk copy is already marked as needing 1320 * no recovery (s_start == 0), then we can safely defer the superblock 1321 * update until the next commit by setting JBD2_FLUSHED. This avoids 1322 * attempting a write to a potential-readonly device. 1323 */ 1324 if (sb->s_start == 0) { 1325 jbd_debug(1, "JBD2: Skipping superblock update on recovered sb " 1326 "(start %ld, seq %d, errno %d)\n", 1327 journal->j_tail, journal->j_tail_sequence, 1328 journal->j_errno); 1329 journal->j_flags |= JBD2_FLUSHED; 1330 } else { 1331 /* Lock here to make assertions happy... */ 1332 mutex_lock(&journal->j_checkpoint_mutex); 1333 /* 1334 * Update log tail information. We use WRITE_FUA since new 1335 * transaction will start reusing journal space and so we 1336 * must make sure information about current log tail is on 1337 * disk before that. 1338 */ 1339 jbd2_journal_update_sb_log_tail(journal, 1340 journal->j_tail_sequence, 1341 journal->j_tail, 1342 WRITE_FUA); 1343 mutex_unlock(&journal->j_checkpoint_mutex); 1344 } 1345 return jbd2_journal_start_thread(journal); 1346 } 1347 1348 static int jbd2_write_superblock(journal_t *journal, int write_op) 1349 { 1350 struct buffer_head *bh = journal->j_sb_buffer; 1351 journal_superblock_t *sb = journal->j_superblock; 1352 int ret; 1353 1354 trace_jbd2_write_superblock(journal, write_op); 1355 if (!(journal->j_flags & JBD2_BARRIER)) 1356 write_op &= ~(REQ_FUA | REQ_FLUSH); 1357 lock_buffer(bh); 1358 if (buffer_write_io_error(bh)) { 1359 /* 1360 * Oh, dear. A previous attempt to write the journal 1361 * superblock failed. This could happen because the 1362 * USB device was yanked out. Or it could happen to 1363 * be a transient write error and maybe the block will 1364 * be remapped. Nothing we can do but to retry the 1365 * write and hope for the best. 1366 */ 1367 printk(KERN_ERR "JBD2: previous I/O error detected " 1368 "for journal superblock update for %s.\n", 1369 journal->j_devname); 1370 clear_buffer_write_io_error(bh); 1371 set_buffer_uptodate(bh); 1372 } 1373 jbd2_superblock_csum_set(journal, sb); 1374 get_bh(bh); 1375 bh->b_end_io = end_buffer_write_sync; 1376 ret = submit_bh(write_op, bh); 1377 wait_on_buffer(bh); 1378 if (buffer_write_io_error(bh)) { 1379 clear_buffer_write_io_error(bh); 1380 set_buffer_uptodate(bh); 1381 ret = -EIO; 1382 } 1383 if (ret) { 1384 printk(KERN_ERR "JBD2: Error %d detected when updating " 1385 "journal superblock for %s.\n", ret, 1386 journal->j_devname); 1387 jbd2_journal_abort(journal, ret); 1388 } 1389 1390 return ret; 1391 } 1392 1393 /** 1394 * jbd2_journal_update_sb_log_tail() - Update log tail in journal sb on disk. 1395 * @journal: The journal to update. 1396 * @tail_tid: TID of the new transaction at the tail of the log 1397 * @tail_block: The first block of the transaction at the tail of the log 1398 * @write_op: With which operation should we write the journal sb 1399 * 1400 * Update a journal's superblock information about log tail and write it to 1401 * disk, waiting for the IO to complete. 1402 */ 1403 int jbd2_journal_update_sb_log_tail(journal_t *journal, tid_t tail_tid, 1404 unsigned long tail_block, int write_op) 1405 { 1406 journal_superblock_t *sb = journal->j_superblock; 1407 int ret; 1408 1409 BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex)); 1410 jbd_debug(1, "JBD2: updating superblock (start %lu, seq %u)\n", 1411 tail_block, tail_tid); 1412 1413 sb->s_sequence = cpu_to_be32(tail_tid); 1414 sb->s_start = cpu_to_be32(tail_block); 1415 1416 ret = jbd2_write_superblock(journal, write_op); 1417 if (ret) 1418 goto out; 1419 1420 /* Log is no longer empty */ 1421 write_lock(&journal->j_state_lock); 1422 WARN_ON(!sb->s_sequence); 1423 journal->j_flags &= ~JBD2_FLUSHED; 1424 write_unlock(&journal->j_state_lock); 1425 1426 out: 1427 return ret; 1428 } 1429 1430 /** 1431 * jbd2_mark_journal_empty() - Mark on disk journal as empty. 1432 * @journal: The journal to update. 1433 * @write_op: With which operation should we write the journal sb 1434 * 1435 * Update a journal's dynamic superblock fields to show that journal is empty. 1436 * Write updated superblock to disk waiting for IO to complete. 1437 */ 1438 static void jbd2_mark_journal_empty(journal_t *journal, int write_op) 1439 { 1440 journal_superblock_t *sb = journal->j_superblock; 1441 1442 BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex)); 1443 read_lock(&journal->j_state_lock); 1444 /* Is it already empty? */ 1445 if (sb->s_start == 0) { 1446 read_unlock(&journal->j_state_lock); 1447 return; 1448 } 1449 jbd_debug(1, "JBD2: Marking journal as empty (seq %d)\n", 1450 journal->j_tail_sequence); 1451 1452 sb->s_sequence = cpu_to_be32(journal->j_tail_sequence); 1453 sb->s_start = cpu_to_be32(0); 1454 read_unlock(&journal->j_state_lock); 1455 1456 jbd2_write_superblock(journal, write_op); 1457 1458 /* Log is no longer empty */ 1459 write_lock(&journal->j_state_lock); 1460 journal->j_flags |= JBD2_FLUSHED; 1461 write_unlock(&journal->j_state_lock); 1462 } 1463 1464 1465 /** 1466 * jbd2_journal_update_sb_errno() - Update error in the journal. 1467 * @journal: The journal to update. 1468 * 1469 * Update a journal's errno. Write updated superblock to disk waiting for IO 1470 * to complete. 1471 */ 1472 void jbd2_journal_update_sb_errno(journal_t *journal) 1473 { 1474 journal_superblock_t *sb = journal->j_superblock; 1475 1476 read_lock(&journal->j_state_lock); 1477 jbd_debug(1, "JBD2: updating superblock error (errno %d)\n", 1478 journal->j_errno); 1479 sb->s_errno = cpu_to_be32(journal->j_errno); 1480 read_unlock(&journal->j_state_lock); 1481 1482 jbd2_write_superblock(journal, WRITE_FUA); 1483 } 1484 EXPORT_SYMBOL(jbd2_journal_update_sb_errno); 1485 1486 /* 1487 * Read the superblock for a given journal, performing initial 1488 * validation of the format. 1489 */ 1490 static int journal_get_superblock(journal_t *journal) 1491 { 1492 struct buffer_head *bh; 1493 journal_superblock_t *sb; 1494 int err = -EIO; 1495 1496 bh = journal->j_sb_buffer; 1497 1498 J_ASSERT(bh != NULL); 1499 if (!buffer_uptodate(bh)) { 1500 ll_rw_block(READ, 1, &bh); 1501 wait_on_buffer(bh); 1502 if (!buffer_uptodate(bh)) { 1503 printk(KERN_ERR 1504 "JBD2: IO error reading journal superblock\n"); 1505 goto out; 1506 } 1507 } 1508 1509 if (buffer_verified(bh)) 1510 return 0; 1511 1512 sb = journal->j_superblock; 1513 1514 err = -EINVAL; 1515 1516 if (sb->s_header.h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER) || 1517 sb->s_blocksize != cpu_to_be32(journal->j_blocksize)) { 1518 printk(KERN_WARNING "JBD2: no valid journal superblock found\n"); 1519 goto out; 1520 } 1521 1522 switch(be32_to_cpu(sb->s_header.h_blocktype)) { 1523 case JBD2_SUPERBLOCK_V1: 1524 journal->j_format_version = 1; 1525 break; 1526 case JBD2_SUPERBLOCK_V2: 1527 journal->j_format_version = 2; 1528 break; 1529 default: 1530 printk(KERN_WARNING "JBD2: unrecognised superblock format ID\n"); 1531 goto out; 1532 } 1533 1534 if (be32_to_cpu(sb->s_maxlen) < journal->j_maxlen) 1535 journal->j_maxlen = be32_to_cpu(sb->s_maxlen); 1536 else if (be32_to_cpu(sb->s_maxlen) > journal->j_maxlen) { 1537 printk(KERN_WARNING "JBD2: journal file too short\n"); 1538 goto out; 1539 } 1540 1541 if (be32_to_cpu(sb->s_first) == 0 || 1542 be32_to_cpu(sb->s_first) >= journal->j_maxlen) { 1543 printk(KERN_WARNING 1544 "JBD2: Invalid start block of journal: %u\n", 1545 be32_to_cpu(sb->s_first)); 1546 goto out; 1547 } 1548 1549 if (jbd2_has_feature_csum2(journal) && 1550 jbd2_has_feature_csum3(journal)) { 1551 /* Can't have checksum v2 and v3 at the same time! */ 1552 printk(KERN_ERR "JBD2: Can't enable checksumming v2 and v3 " 1553 "at the same time!\n"); 1554 goto out; 1555 } 1556 1557 if (jbd2_journal_has_csum_v2or3_feature(journal) && 1558 jbd2_has_feature_checksum(journal)) { 1559 /* Can't have checksum v1 and v2 on at the same time! */ 1560 printk(KERN_ERR "JBD2: Can't enable checksumming v1 and v2/3 " 1561 "at the same time!\n"); 1562 goto out; 1563 } 1564 1565 if (!jbd2_verify_csum_type(journal, sb)) { 1566 printk(KERN_ERR "JBD2: Unknown checksum type\n"); 1567 goto out; 1568 } 1569 1570 /* Load the checksum driver */ 1571 if (jbd2_journal_has_csum_v2or3_feature(journal)) { 1572 journal->j_chksum_driver = crypto_alloc_shash("crc32c", 0, 0); 1573 if (IS_ERR(journal->j_chksum_driver)) { 1574 printk(KERN_ERR "JBD2: Cannot load crc32c driver.\n"); 1575 err = PTR_ERR(journal->j_chksum_driver); 1576 journal->j_chksum_driver = NULL; 1577 goto out; 1578 } 1579 } 1580 1581 /* Check superblock checksum */ 1582 if (!jbd2_superblock_csum_verify(journal, sb)) { 1583 printk(KERN_ERR "JBD2: journal checksum error\n"); 1584 err = -EFSBADCRC; 1585 goto out; 1586 } 1587 1588 /* Precompute checksum seed for all metadata */ 1589 if (jbd2_journal_has_csum_v2or3(journal)) 1590 journal->j_csum_seed = jbd2_chksum(journal, ~0, sb->s_uuid, 1591 sizeof(sb->s_uuid)); 1592 1593 set_buffer_verified(bh); 1594 1595 return 0; 1596 1597 out: 1598 journal_fail_superblock(journal); 1599 return err; 1600 } 1601 1602 /* 1603 * Load the on-disk journal superblock and read the key fields into the 1604 * journal_t. 1605 */ 1606 1607 static int load_superblock(journal_t *journal) 1608 { 1609 int err; 1610 journal_superblock_t *sb; 1611 1612 err = journal_get_superblock(journal); 1613 if (err) 1614 return err; 1615 1616 sb = journal->j_superblock; 1617 1618 journal->j_tail_sequence = be32_to_cpu(sb->s_sequence); 1619 journal->j_tail = be32_to_cpu(sb->s_start); 1620 journal->j_first = be32_to_cpu(sb->s_first); 1621 journal->j_last = be32_to_cpu(sb->s_maxlen); 1622 journal->j_errno = be32_to_cpu(sb->s_errno); 1623 1624 return 0; 1625 } 1626 1627 1628 /** 1629 * int jbd2_journal_load() - Read journal from disk. 1630 * @journal: Journal to act on. 1631 * 1632 * Given a journal_t structure which tells us which disk blocks contain 1633 * a journal, read the journal from disk to initialise the in-memory 1634 * structures. 1635 */ 1636 int jbd2_journal_load(journal_t *journal) 1637 { 1638 int err; 1639 journal_superblock_t *sb; 1640 1641 err = load_superblock(journal); 1642 if (err) 1643 return err; 1644 1645 sb = journal->j_superblock; 1646 /* If this is a V2 superblock, then we have to check the 1647 * features flags on it. */ 1648 1649 if (journal->j_format_version >= 2) { 1650 if ((sb->s_feature_ro_compat & 1651 ~cpu_to_be32(JBD2_KNOWN_ROCOMPAT_FEATURES)) || 1652 (sb->s_feature_incompat & 1653 ~cpu_to_be32(JBD2_KNOWN_INCOMPAT_FEATURES))) { 1654 printk(KERN_WARNING 1655 "JBD2: Unrecognised features on journal\n"); 1656 return -EINVAL; 1657 } 1658 } 1659 1660 /* 1661 * Create a slab for this blocksize 1662 */ 1663 err = jbd2_journal_create_slab(be32_to_cpu(sb->s_blocksize)); 1664 if (err) 1665 return err; 1666 1667 /* Let the recovery code check whether it needs to recover any 1668 * data from the journal. */ 1669 if (jbd2_journal_recover(journal)) 1670 goto recovery_error; 1671 1672 if (journal->j_failed_commit) { 1673 printk(KERN_ERR "JBD2: journal transaction %u on %s " 1674 "is corrupt.\n", journal->j_failed_commit, 1675 journal->j_devname); 1676 return -EFSCORRUPTED; 1677 } 1678 1679 /* OK, we've finished with the dynamic journal bits: 1680 * reinitialise the dynamic contents of the superblock in memory 1681 * and reset them on disk. */ 1682 if (journal_reset(journal)) 1683 goto recovery_error; 1684 1685 journal->j_flags &= ~JBD2_ABORT; 1686 journal->j_flags |= JBD2_LOADED; 1687 return 0; 1688 1689 recovery_error: 1690 printk(KERN_WARNING "JBD2: recovery failed\n"); 1691 return -EIO; 1692 } 1693 1694 /** 1695 * void jbd2_journal_destroy() - Release a journal_t structure. 1696 * @journal: Journal to act on. 1697 * 1698 * Release a journal_t structure once it is no longer in use by the 1699 * journaled object. 1700 * Return <0 if we couldn't clean up the journal. 1701 */ 1702 int jbd2_journal_destroy(journal_t *journal) 1703 { 1704 int err = 0; 1705 1706 /* Wait for the commit thread to wake up and die. */ 1707 journal_kill_thread(journal); 1708 1709 /* Force a final log commit */ 1710 if (journal->j_running_transaction) 1711 jbd2_journal_commit_transaction(journal); 1712 1713 /* Force any old transactions to disk */ 1714 1715 /* Totally anal locking here... */ 1716 spin_lock(&journal->j_list_lock); 1717 while (journal->j_checkpoint_transactions != NULL) { 1718 spin_unlock(&journal->j_list_lock); 1719 mutex_lock(&journal->j_checkpoint_mutex); 1720 err = jbd2_log_do_checkpoint(journal); 1721 mutex_unlock(&journal->j_checkpoint_mutex); 1722 /* 1723 * If checkpointing failed, just free the buffers to avoid 1724 * looping forever 1725 */ 1726 if (err) { 1727 jbd2_journal_destroy_checkpoint(journal); 1728 spin_lock(&journal->j_list_lock); 1729 break; 1730 } 1731 spin_lock(&journal->j_list_lock); 1732 } 1733 1734 J_ASSERT(journal->j_running_transaction == NULL); 1735 J_ASSERT(journal->j_committing_transaction == NULL); 1736 J_ASSERT(journal->j_checkpoint_transactions == NULL); 1737 spin_unlock(&journal->j_list_lock); 1738 1739 if (journal->j_sb_buffer) { 1740 if (!is_journal_aborted(journal)) { 1741 mutex_lock(&journal->j_checkpoint_mutex); 1742 1743 write_lock(&journal->j_state_lock); 1744 journal->j_tail_sequence = 1745 ++journal->j_transaction_sequence; 1746 write_unlock(&journal->j_state_lock); 1747 1748 jbd2_mark_journal_empty(journal, WRITE_FLUSH_FUA); 1749 mutex_unlock(&journal->j_checkpoint_mutex); 1750 } else 1751 err = -EIO; 1752 brelse(journal->j_sb_buffer); 1753 } 1754 1755 if (journal->j_proc_entry) 1756 jbd2_stats_proc_exit(journal); 1757 iput(journal->j_inode); 1758 if (journal->j_revoke) 1759 jbd2_journal_destroy_revoke(journal); 1760 if (journal->j_chksum_driver) 1761 crypto_free_shash(journal->j_chksum_driver); 1762 kfree(journal->j_wbuf); 1763 kfree(journal); 1764 1765 return err; 1766 } 1767 1768 1769 /** 1770 *int jbd2_journal_check_used_features () - Check if features specified are used. 1771 * @journal: Journal to check. 1772 * @compat: bitmask of compatible features 1773 * @ro: bitmask of features that force read-only mount 1774 * @incompat: bitmask of incompatible features 1775 * 1776 * Check whether the journal uses all of a given set of 1777 * features. Return true (non-zero) if it does. 1778 **/ 1779 1780 int jbd2_journal_check_used_features (journal_t *journal, unsigned long compat, 1781 unsigned long ro, unsigned long incompat) 1782 { 1783 journal_superblock_t *sb; 1784 1785 if (!compat && !ro && !incompat) 1786 return 1; 1787 /* Load journal superblock if it is not loaded yet. */ 1788 if (journal->j_format_version == 0 && 1789 journal_get_superblock(journal) != 0) 1790 return 0; 1791 if (journal->j_format_version == 1) 1792 return 0; 1793 1794 sb = journal->j_superblock; 1795 1796 if (((be32_to_cpu(sb->s_feature_compat) & compat) == compat) && 1797 ((be32_to_cpu(sb->s_feature_ro_compat) & ro) == ro) && 1798 ((be32_to_cpu(sb->s_feature_incompat) & incompat) == incompat)) 1799 return 1; 1800 1801 return 0; 1802 } 1803 1804 /** 1805 * int jbd2_journal_check_available_features() - Check feature set in journalling layer 1806 * @journal: Journal to check. 1807 * @compat: bitmask of compatible features 1808 * @ro: bitmask of features that force read-only mount 1809 * @incompat: bitmask of incompatible features 1810 * 1811 * Check whether the journaling code supports the use of 1812 * all of a given set of features on this journal. Return true 1813 * (non-zero) if it can. */ 1814 1815 int jbd2_journal_check_available_features (journal_t *journal, unsigned long compat, 1816 unsigned long ro, unsigned long incompat) 1817 { 1818 if (!compat && !ro && !incompat) 1819 return 1; 1820 1821 /* We can support any known requested features iff the 1822 * superblock is in version 2. Otherwise we fail to support any 1823 * extended sb features. */ 1824 1825 if (journal->j_format_version != 2) 1826 return 0; 1827 1828 if ((compat & JBD2_KNOWN_COMPAT_FEATURES) == compat && 1829 (ro & JBD2_KNOWN_ROCOMPAT_FEATURES) == ro && 1830 (incompat & JBD2_KNOWN_INCOMPAT_FEATURES) == incompat) 1831 return 1; 1832 1833 return 0; 1834 } 1835 1836 /** 1837 * int jbd2_journal_set_features () - Mark a given journal feature in the superblock 1838 * @journal: Journal to act on. 1839 * @compat: bitmask of compatible features 1840 * @ro: bitmask of features that force read-only mount 1841 * @incompat: bitmask of incompatible features 1842 * 1843 * Mark a given journal feature as present on the 1844 * superblock. Returns true if the requested features could be set. 1845 * 1846 */ 1847 1848 int jbd2_journal_set_features (journal_t *journal, unsigned long compat, 1849 unsigned long ro, unsigned long incompat) 1850 { 1851 #define INCOMPAT_FEATURE_ON(f) \ 1852 ((incompat & (f)) && !(sb->s_feature_incompat & cpu_to_be32(f))) 1853 #define COMPAT_FEATURE_ON(f) \ 1854 ((compat & (f)) && !(sb->s_feature_compat & cpu_to_be32(f))) 1855 journal_superblock_t *sb; 1856 1857 if (jbd2_journal_check_used_features(journal, compat, ro, incompat)) 1858 return 1; 1859 1860 if (!jbd2_journal_check_available_features(journal, compat, ro, incompat)) 1861 return 0; 1862 1863 /* If enabling v2 checksums, turn on v3 instead */ 1864 if (incompat & JBD2_FEATURE_INCOMPAT_CSUM_V2) { 1865 incompat &= ~JBD2_FEATURE_INCOMPAT_CSUM_V2; 1866 incompat |= JBD2_FEATURE_INCOMPAT_CSUM_V3; 1867 } 1868 1869 /* Asking for checksumming v3 and v1? Only give them v3. */ 1870 if (incompat & JBD2_FEATURE_INCOMPAT_CSUM_V3 && 1871 compat & JBD2_FEATURE_COMPAT_CHECKSUM) 1872 compat &= ~JBD2_FEATURE_COMPAT_CHECKSUM; 1873 1874 jbd_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n", 1875 compat, ro, incompat); 1876 1877 sb = journal->j_superblock; 1878 1879 /* If enabling v3 checksums, update superblock */ 1880 if (INCOMPAT_FEATURE_ON(JBD2_FEATURE_INCOMPAT_CSUM_V3)) { 1881 sb->s_checksum_type = JBD2_CRC32C_CHKSUM; 1882 sb->s_feature_compat &= 1883 ~cpu_to_be32(JBD2_FEATURE_COMPAT_CHECKSUM); 1884 1885 /* Load the checksum driver */ 1886 if (journal->j_chksum_driver == NULL) { 1887 journal->j_chksum_driver = crypto_alloc_shash("crc32c", 1888 0, 0); 1889 if (IS_ERR(journal->j_chksum_driver)) { 1890 printk(KERN_ERR "JBD2: Cannot load crc32c " 1891 "driver.\n"); 1892 journal->j_chksum_driver = NULL; 1893 return 0; 1894 } 1895 1896 /* Precompute checksum seed for all metadata */ 1897 journal->j_csum_seed = jbd2_chksum(journal, ~0, 1898 sb->s_uuid, 1899 sizeof(sb->s_uuid)); 1900 } 1901 } 1902 1903 /* If enabling v1 checksums, downgrade superblock */ 1904 if (COMPAT_FEATURE_ON(JBD2_FEATURE_COMPAT_CHECKSUM)) 1905 sb->s_feature_incompat &= 1906 ~cpu_to_be32(JBD2_FEATURE_INCOMPAT_CSUM_V2 | 1907 JBD2_FEATURE_INCOMPAT_CSUM_V3); 1908 1909 sb->s_feature_compat |= cpu_to_be32(compat); 1910 sb->s_feature_ro_compat |= cpu_to_be32(ro); 1911 sb->s_feature_incompat |= cpu_to_be32(incompat); 1912 1913 return 1; 1914 #undef COMPAT_FEATURE_ON 1915 #undef INCOMPAT_FEATURE_ON 1916 } 1917 1918 /* 1919 * jbd2_journal_clear_features () - Clear a given journal feature in the 1920 * superblock 1921 * @journal: Journal to act on. 1922 * @compat: bitmask of compatible features 1923 * @ro: bitmask of features that force read-only mount 1924 * @incompat: bitmask of incompatible features 1925 * 1926 * Clear a given journal feature as present on the 1927 * superblock. 1928 */ 1929 void jbd2_journal_clear_features(journal_t *journal, unsigned long compat, 1930 unsigned long ro, unsigned long incompat) 1931 { 1932 journal_superblock_t *sb; 1933 1934 jbd_debug(1, "Clear features 0x%lx/0x%lx/0x%lx\n", 1935 compat, ro, incompat); 1936 1937 sb = journal->j_superblock; 1938 1939 sb->s_feature_compat &= ~cpu_to_be32(compat); 1940 sb->s_feature_ro_compat &= ~cpu_to_be32(ro); 1941 sb->s_feature_incompat &= ~cpu_to_be32(incompat); 1942 } 1943 EXPORT_SYMBOL(jbd2_journal_clear_features); 1944 1945 /** 1946 * int jbd2_journal_flush () - Flush journal 1947 * @journal: Journal to act on. 1948 * 1949 * Flush all data for a given journal to disk and empty the journal. 1950 * Filesystems can use this when remounting readonly to ensure that 1951 * recovery does not need to happen on remount. 1952 */ 1953 1954 int jbd2_journal_flush(journal_t *journal) 1955 { 1956 int err = 0; 1957 transaction_t *transaction = NULL; 1958 1959 write_lock(&journal->j_state_lock); 1960 1961 /* Force everything buffered to the log... */ 1962 if (journal->j_running_transaction) { 1963 transaction = journal->j_running_transaction; 1964 __jbd2_log_start_commit(journal, transaction->t_tid); 1965 } else if (journal->j_committing_transaction) 1966 transaction = journal->j_committing_transaction; 1967 1968 /* Wait for the log commit to complete... */ 1969 if (transaction) { 1970 tid_t tid = transaction->t_tid; 1971 1972 write_unlock(&journal->j_state_lock); 1973 jbd2_log_wait_commit(journal, tid); 1974 } else { 1975 write_unlock(&journal->j_state_lock); 1976 } 1977 1978 /* ...and flush everything in the log out to disk. */ 1979 spin_lock(&journal->j_list_lock); 1980 while (!err && journal->j_checkpoint_transactions != NULL) { 1981 spin_unlock(&journal->j_list_lock); 1982 mutex_lock(&journal->j_checkpoint_mutex); 1983 err = jbd2_log_do_checkpoint(journal); 1984 mutex_unlock(&journal->j_checkpoint_mutex); 1985 spin_lock(&journal->j_list_lock); 1986 } 1987 spin_unlock(&journal->j_list_lock); 1988 1989 if (is_journal_aborted(journal)) 1990 return -EIO; 1991 1992 mutex_lock(&journal->j_checkpoint_mutex); 1993 if (!err) { 1994 err = jbd2_cleanup_journal_tail(journal); 1995 if (err < 0) { 1996 mutex_unlock(&journal->j_checkpoint_mutex); 1997 goto out; 1998 } 1999 err = 0; 2000 } 2001 2002 /* Finally, mark the journal as really needing no recovery. 2003 * This sets s_start==0 in the underlying superblock, which is 2004 * the magic code for a fully-recovered superblock. Any future 2005 * commits of data to the journal will restore the current 2006 * s_start value. */ 2007 jbd2_mark_journal_empty(journal, WRITE_FUA); 2008 mutex_unlock(&journal->j_checkpoint_mutex); 2009 write_lock(&journal->j_state_lock); 2010 J_ASSERT(!journal->j_running_transaction); 2011 J_ASSERT(!journal->j_committing_transaction); 2012 J_ASSERT(!journal->j_checkpoint_transactions); 2013 J_ASSERT(journal->j_head == journal->j_tail); 2014 J_ASSERT(journal->j_tail_sequence == journal->j_transaction_sequence); 2015 write_unlock(&journal->j_state_lock); 2016 out: 2017 return err; 2018 } 2019 2020 /** 2021 * int jbd2_journal_wipe() - Wipe journal contents 2022 * @journal: Journal to act on. 2023 * @write: flag (see below) 2024 * 2025 * Wipe out all of the contents of a journal, safely. This will produce 2026 * a warning if the journal contains any valid recovery information. 2027 * Must be called between journal_init_*() and jbd2_journal_load(). 2028 * 2029 * If 'write' is non-zero, then we wipe out the journal on disk; otherwise 2030 * we merely suppress recovery. 2031 */ 2032 2033 int jbd2_journal_wipe(journal_t *journal, int write) 2034 { 2035 int err = 0; 2036 2037 J_ASSERT (!(journal->j_flags & JBD2_LOADED)); 2038 2039 err = load_superblock(journal); 2040 if (err) 2041 return err; 2042 2043 if (!journal->j_tail) 2044 goto no_recovery; 2045 2046 printk(KERN_WARNING "JBD2: %s recovery information on journal\n", 2047 write ? "Clearing" : "Ignoring"); 2048 2049 err = jbd2_journal_skip_recovery(journal); 2050 if (write) { 2051 /* Lock to make assertions happy... */ 2052 mutex_lock(&journal->j_checkpoint_mutex); 2053 jbd2_mark_journal_empty(journal, WRITE_FUA); 2054 mutex_unlock(&journal->j_checkpoint_mutex); 2055 } 2056 2057 no_recovery: 2058 return err; 2059 } 2060 2061 /* 2062 * Journal abort has very specific semantics, which we describe 2063 * for journal abort. 2064 * 2065 * Two internal functions, which provide abort to the jbd layer 2066 * itself are here. 2067 */ 2068 2069 /* 2070 * Quick version for internal journal use (doesn't lock the journal). 2071 * Aborts hard --- we mark the abort as occurred, but do _nothing_ else, 2072 * and don't attempt to make any other journal updates. 2073 */ 2074 void __jbd2_journal_abort_hard(journal_t *journal) 2075 { 2076 transaction_t *transaction; 2077 2078 if (journal->j_flags & JBD2_ABORT) 2079 return; 2080 2081 printk(KERN_ERR "Aborting journal on device %s.\n", 2082 journal->j_devname); 2083 2084 write_lock(&journal->j_state_lock); 2085 journal->j_flags |= JBD2_ABORT; 2086 transaction = journal->j_running_transaction; 2087 if (transaction) 2088 __jbd2_log_start_commit(journal, transaction->t_tid); 2089 write_unlock(&journal->j_state_lock); 2090 } 2091 2092 /* Soft abort: record the abort error status in the journal superblock, 2093 * but don't do any other IO. */ 2094 static void __journal_abort_soft (journal_t *journal, int errno) 2095 { 2096 if (journal->j_flags & JBD2_ABORT) 2097 return; 2098 2099 if (!journal->j_errno) 2100 journal->j_errno = errno; 2101 2102 __jbd2_journal_abort_hard(journal); 2103 2104 if (errno) { 2105 jbd2_journal_update_sb_errno(journal); 2106 write_lock(&journal->j_state_lock); 2107 journal->j_flags |= JBD2_REC_ERR; 2108 write_unlock(&journal->j_state_lock); 2109 } 2110 } 2111 2112 /** 2113 * void jbd2_journal_abort () - Shutdown the journal immediately. 2114 * @journal: the journal to shutdown. 2115 * @errno: an error number to record in the journal indicating 2116 * the reason for the shutdown. 2117 * 2118 * Perform a complete, immediate shutdown of the ENTIRE 2119 * journal (not of a single transaction). This operation cannot be 2120 * undone without closing and reopening the journal. 2121 * 2122 * The jbd2_journal_abort function is intended to support higher level error 2123 * recovery mechanisms such as the ext2/ext3 remount-readonly error 2124 * mode. 2125 * 2126 * Journal abort has very specific semantics. Any existing dirty, 2127 * unjournaled buffers in the main filesystem will still be written to 2128 * disk by bdflush, but the journaling mechanism will be suspended 2129 * immediately and no further transaction commits will be honoured. 2130 * 2131 * Any dirty, journaled buffers will be written back to disk without 2132 * hitting the journal. Atomicity cannot be guaranteed on an aborted 2133 * filesystem, but we _do_ attempt to leave as much data as possible 2134 * behind for fsck to use for cleanup. 2135 * 2136 * Any attempt to get a new transaction handle on a journal which is in 2137 * ABORT state will just result in an -EROFS error return. A 2138 * jbd2_journal_stop on an existing handle will return -EIO if we have 2139 * entered abort state during the update. 2140 * 2141 * Recursive transactions are not disturbed by journal abort until the 2142 * final jbd2_journal_stop, which will receive the -EIO error. 2143 * 2144 * Finally, the jbd2_journal_abort call allows the caller to supply an errno 2145 * which will be recorded (if possible) in the journal superblock. This 2146 * allows a client to record failure conditions in the middle of a 2147 * transaction without having to complete the transaction to record the 2148 * failure to disk. ext3_error, for example, now uses this 2149 * functionality. 2150 * 2151 * Errors which originate from within the journaling layer will NOT 2152 * supply an errno; a null errno implies that absolutely no further 2153 * writes are done to the journal (unless there are any already in 2154 * progress). 2155 * 2156 */ 2157 2158 void jbd2_journal_abort(journal_t *journal, int errno) 2159 { 2160 __journal_abort_soft(journal, errno); 2161 } 2162 2163 /** 2164 * int jbd2_journal_errno () - returns the journal's error state. 2165 * @journal: journal to examine. 2166 * 2167 * This is the errno number set with jbd2_journal_abort(), the last 2168 * time the journal was mounted - if the journal was stopped 2169 * without calling abort this will be 0. 2170 * 2171 * If the journal has been aborted on this mount time -EROFS will 2172 * be returned. 2173 */ 2174 int jbd2_journal_errno(journal_t *journal) 2175 { 2176 int err; 2177 2178 read_lock(&journal->j_state_lock); 2179 if (journal->j_flags & JBD2_ABORT) 2180 err = -EROFS; 2181 else 2182 err = journal->j_errno; 2183 read_unlock(&journal->j_state_lock); 2184 return err; 2185 } 2186 2187 /** 2188 * int jbd2_journal_clear_err () - clears the journal's error state 2189 * @journal: journal to act on. 2190 * 2191 * An error must be cleared or acked to take a FS out of readonly 2192 * mode. 2193 */ 2194 int jbd2_journal_clear_err(journal_t *journal) 2195 { 2196 int err = 0; 2197 2198 write_lock(&journal->j_state_lock); 2199 if (journal->j_flags & JBD2_ABORT) 2200 err = -EROFS; 2201 else 2202 journal->j_errno = 0; 2203 write_unlock(&journal->j_state_lock); 2204 return err; 2205 } 2206 2207 /** 2208 * void jbd2_journal_ack_err() - Ack journal err. 2209 * @journal: journal to act on. 2210 * 2211 * An error must be cleared or acked to take a FS out of readonly 2212 * mode. 2213 */ 2214 void jbd2_journal_ack_err(journal_t *journal) 2215 { 2216 write_lock(&journal->j_state_lock); 2217 if (journal->j_errno) 2218 journal->j_flags |= JBD2_ACK_ERR; 2219 write_unlock(&journal->j_state_lock); 2220 } 2221 2222 int jbd2_journal_blocks_per_page(struct inode *inode) 2223 { 2224 return 1 << (PAGE_SHIFT - inode->i_sb->s_blocksize_bits); 2225 } 2226 2227 /* 2228 * helper functions to deal with 32 or 64bit block numbers. 2229 */ 2230 size_t journal_tag_bytes(journal_t *journal) 2231 { 2232 size_t sz; 2233 2234 if (jbd2_has_feature_csum3(journal)) 2235 return sizeof(journal_block_tag3_t); 2236 2237 sz = sizeof(journal_block_tag_t); 2238 2239 if (jbd2_has_feature_csum2(journal)) 2240 sz += sizeof(__u16); 2241 2242 if (jbd2_has_feature_64bit(journal)) 2243 return sz; 2244 else 2245 return sz - sizeof(__u32); 2246 } 2247 2248 /* 2249 * JBD memory management 2250 * 2251 * These functions are used to allocate block-sized chunks of memory 2252 * used for making copies of buffer_head data. Very often it will be 2253 * page-sized chunks of data, but sometimes it will be in 2254 * sub-page-size chunks. (For example, 16k pages on Power systems 2255 * with a 4k block file system.) For blocks smaller than a page, we 2256 * use a SLAB allocator. There are slab caches for each block size, 2257 * which are allocated at mount time, if necessary, and we only free 2258 * (all of) the slab caches when/if the jbd2 module is unloaded. For 2259 * this reason we don't need to a mutex to protect access to 2260 * jbd2_slab[] allocating or releasing memory; only in 2261 * jbd2_journal_create_slab(). 2262 */ 2263 #define JBD2_MAX_SLABS 8 2264 static struct kmem_cache *jbd2_slab[JBD2_MAX_SLABS]; 2265 2266 static const char *jbd2_slab_names[JBD2_MAX_SLABS] = { 2267 "jbd2_1k", "jbd2_2k", "jbd2_4k", "jbd2_8k", 2268 "jbd2_16k", "jbd2_32k", "jbd2_64k", "jbd2_128k" 2269 }; 2270 2271 2272 static void jbd2_journal_destroy_slabs(void) 2273 { 2274 int i; 2275 2276 for (i = 0; i < JBD2_MAX_SLABS; i++) { 2277 if (jbd2_slab[i]) 2278 kmem_cache_destroy(jbd2_slab[i]); 2279 jbd2_slab[i] = NULL; 2280 } 2281 } 2282 2283 static int jbd2_journal_create_slab(size_t size) 2284 { 2285 static DEFINE_MUTEX(jbd2_slab_create_mutex); 2286 int i = order_base_2(size) - 10; 2287 size_t slab_size; 2288 2289 if (size == PAGE_SIZE) 2290 return 0; 2291 2292 if (i >= JBD2_MAX_SLABS) 2293 return -EINVAL; 2294 2295 if (unlikely(i < 0)) 2296 i = 0; 2297 mutex_lock(&jbd2_slab_create_mutex); 2298 if (jbd2_slab[i]) { 2299 mutex_unlock(&jbd2_slab_create_mutex); 2300 return 0; /* Already created */ 2301 } 2302 2303 slab_size = 1 << (i+10); 2304 jbd2_slab[i] = kmem_cache_create(jbd2_slab_names[i], slab_size, 2305 slab_size, 0, NULL); 2306 mutex_unlock(&jbd2_slab_create_mutex); 2307 if (!jbd2_slab[i]) { 2308 printk(KERN_EMERG "JBD2: no memory for jbd2_slab cache\n"); 2309 return -ENOMEM; 2310 } 2311 return 0; 2312 } 2313 2314 static struct kmem_cache *get_slab(size_t size) 2315 { 2316 int i = order_base_2(size) - 10; 2317 2318 BUG_ON(i >= JBD2_MAX_SLABS); 2319 if (unlikely(i < 0)) 2320 i = 0; 2321 BUG_ON(jbd2_slab[i] == NULL); 2322 return jbd2_slab[i]; 2323 } 2324 2325 void *jbd2_alloc(size_t size, gfp_t flags) 2326 { 2327 void *ptr; 2328 2329 BUG_ON(size & (size-1)); /* Must be a power of 2 */ 2330 2331 flags |= __GFP_REPEAT; 2332 if (size == PAGE_SIZE) 2333 ptr = (void *)__get_free_pages(flags, 0); 2334 else if (size > PAGE_SIZE) { 2335 int order = get_order(size); 2336 2337 if (order < 3) 2338 ptr = (void *)__get_free_pages(flags, order); 2339 else 2340 ptr = vmalloc(size); 2341 } else 2342 ptr = kmem_cache_alloc(get_slab(size), flags); 2343 2344 /* Check alignment; SLUB has gotten this wrong in the past, 2345 * and this can lead to user data corruption! */ 2346 BUG_ON(((unsigned long) ptr) & (size-1)); 2347 2348 return ptr; 2349 } 2350 2351 void jbd2_free(void *ptr, size_t size) 2352 { 2353 if (size == PAGE_SIZE) { 2354 free_pages((unsigned long)ptr, 0); 2355 return; 2356 } 2357 if (size > PAGE_SIZE) { 2358 int order = get_order(size); 2359 2360 if (order < 3) 2361 free_pages((unsigned long)ptr, order); 2362 else 2363 vfree(ptr); 2364 return; 2365 } 2366 kmem_cache_free(get_slab(size), ptr); 2367 }; 2368 2369 /* 2370 * Journal_head storage management 2371 */ 2372 static struct kmem_cache *jbd2_journal_head_cache; 2373 #ifdef CONFIG_JBD2_DEBUG 2374 static atomic_t nr_journal_heads = ATOMIC_INIT(0); 2375 #endif 2376 2377 static int jbd2_journal_init_journal_head_cache(void) 2378 { 2379 int retval; 2380 2381 J_ASSERT(jbd2_journal_head_cache == NULL); 2382 jbd2_journal_head_cache = kmem_cache_create("jbd2_journal_head", 2383 sizeof(struct journal_head), 2384 0, /* offset */ 2385 SLAB_TEMPORARY | SLAB_DESTROY_BY_RCU, 2386 NULL); /* ctor */ 2387 retval = 0; 2388 if (!jbd2_journal_head_cache) { 2389 retval = -ENOMEM; 2390 printk(KERN_EMERG "JBD2: no memory for journal_head cache\n"); 2391 } 2392 return retval; 2393 } 2394 2395 static void jbd2_journal_destroy_journal_head_cache(void) 2396 { 2397 if (jbd2_journal_head_cache) { 2398 kmem_cache_destroy(jbd2_journal_head_cache); 2399 jbd2_journal_head_cache = NULL; 2400 } 2401 } 2402 2403 /* 2404 * journal_head splicing and dicing 2405 */ 2406 static struct journal_head *journal_alloc_journal_head(void) 2407 { 2408 struct journal_head *ret; 2409 2410 #ifdef CONFIG_JBD2_DEBUG 2411 atomic_inc(&nr_journal_heads); 2412 #endif 2413 ret = kmem_cache_zalloc(jbd2_journal_head_cache, GFP_NOFS); 2414 if (!ret) { 2415 jbd_debug(1, "out of memory for journal_head\n"); 2416 pr_notice_ratelimited("ENOMEM in %s, retrying.\n", __func__); 2417 ret = kmem_cache_zalloc(jbd2_journal_head_cache, 2418 GFP_NOFS | __GFP_NOFAIL); 2419 } 2420 return ret; 2421 } 2422 2423 static void journal_free_journal_head(struct journal_head *jh) 2424 { 2425 #ifdef CONFIG_JBD2_DEBUG 2426 atomic_dec(&nr_journal_heads); 2427 memset(jh, JBD2_POISON_FREE, sizeof(*jh)); 2428 #endif 2429 kmem_cache_free(jbd2_journal_head_cache, jh); 2430 } 2431 2432 /* 2433 * A journal_head is attached to a buffer_head whenever JBD has an 2434 * interest in the buffer. 2435 * 2436 * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit 2437 * is set. This bit is tested in core kernel code where we need to take 2438 * JBD-specific actions. Testing the zeroness of ->b_private is not reliable 2439 * there. 2440 * 2441 * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one. 2442 * 2443 * When a buffer has its BH_JBD bit set it is immune from being released by 2444 * core kernel code, mainly via ->b_count. 2445 * 2446 * A journal_head is detached from its buffer_head when the journal_head's 2447 * b_jcount reaches zero. Running transaction (b_transaction) and checkpoint 2448 * transaction (b_cp_transaction) hold their references to b_jcount. 2449 * 2450 * Various places in the kernel want to attach a journal_head to a buffer_head 2451 * _before_ attaching the journal_head to a transaction. To protect the 2452 * journal_head in this situation, jbd2_journal_add_journal_head elevates the 2453 * journal_head's b_jcount refcount by one. The caller must call 2454 * jbd2_journal_put_journal_head() to undo this. 2455 * 2456 * So the typical usage would be: 2457 * 2458 * (Attach a journal_head if needed. Increments b_jcount) 2459 * struct journal_head *jh = jbd2_journal_add_journal_head(bh); 2460 * ... 2461 * (Get another reference for transaction) 2462 * jbd2_journal_grab_journal_head(bh); 2463 * jh->b_transaction = xxx; 2464 * (Put original reference) 2465 * jbd2_journal_put_journal_head(jh); 2466 */ 2467 2468 /* 2469 * Give a buffer_head a journal_head. 2470 * 2471 * May sleep. 2472 */ 2473 struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh) 2474 { 2475 struct journal_head *jh; 2476 struct journal_head *new_jh = NULL; 2477 2478 repeat: 2479 if (!buffer_jbd(bh)) 2480 new_jh = journal_alloc_journal_head(); 2481 2482 jbd_lock_bh_journal_head(bh); 2483 if (buffer_jbd(bh)) { 2484 jh = bh2jh(bh); 2485 } else { 2486 J_ASSERT_BH(bh, 2487 (atomic_read(&bh->b_count) > 0) || 2488 (bh->b_page && bh->b_page->mapping)); 2489 2490 if (!new_jh) { 2491 jbd_unlock_bh_journal_head(bh); 2492 goto repeat; 2493 } 2494 2495 jh = new_jh; 2496 new_jh = NULL; /* We consumed it */ 2497 set_buffer_jbd(bh); 2498 bh->b_private = jh; 2499 jh->b_bh = bh; 2500 get_bh(bh); 2501 BUFFER_TRACE(bh, "added journal_head"); 2502 } 2503 jh->b_jcount++; 2504 jbd_unlock_bh_journal_head(bh); 2505 if (new_jh) 2506 journal_free_journal_head(new_jh); 2507 return bh->b_private; 2508 } 2509 2510 /* 2511 * Grab a ref against this buffer_head's journal_head. If it ended up not 2512 * having a journal_head, return NULL 2513 */ 2514 struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh) 2515 { 2516 struct journal_head *jh = NULL; 2517 2518 jbd_lock_bh_journal_head(bh); 2519 if (buffer_jbd(bh)) { 2520 jh = bh2jh(bh); 2521 jh->b_jcount++; 2522 } 2523 jbd_unlock_bh_journal_head(bh); 2524 return jh; 2525 } 2526 2527 static void __journal_remove_journal_head(struct buffer_head *bh) 2528 { 2529 struct journal_head *jh = bh2jh(bh); 2530 2531 J_ASSERT_JH(jh, jh->b_jcount >= 0); 2532 J_ASSERT_JH(jh, jh->b_transaction == NULL); 2533 J_ASSERT_JH(jh, jh->b_next_transaction == NULL); 2534 J_ASSERT_JH(jh, jh->b_cp_transaction == NULL); 2535 J_ASSERT_JH(jh, jh->b_jlist == BJ_None); 2536 J_ASSERT_BH(bh, buffer_jbd(bh)); 2537 J_ASSERT_BH(bh, jh2bh(jh) == bh); 2538 BUFFER_TRACE(bh, "remove journal_head"); 2539 if (jh->b_frozen_data) { 2540 printk(KERN_WARNING "%s: freeing b_frozen_data\n", __func__); 2541 jbd2_free(jh->b_frozen_data, bh->b_size); 2542 } 2543 if (jh->b_committed_data) { 2544 printk(KERN_WARNING "%s: freeing b_committed_data\n", __func__); 2545 jbd2_free(jh->b_committed_data, bh->b_size); 2546 } 2547 bh->b_private = NULL; 2548 jh->b_bh = NULL; /* debug, really */ 2549 clear_buffer_jbd(bh); 2550 journal_free_journal_head(jh); 2551 } 2552 2553 /* 2554 * Drop a reference on the passed journal_head. If it fell to zero then 2555 * release the journal_head from the buffer_head. 2556 */ 2557 void jbd2_journal_put_journal_head(struct journal_head *jh) 2558 { 2559 struct buffer_head *bh = jh2bh(jh); 2560 2561 jbd_lock_bh_journal_head(bh); 2562 J_ASSERT_JH(jh, jh->b_jcount > 0); 2563 --jh->b_jcount; 2564 if (!jh->b_jcount) { 2565 __journal_remove_journal_head(bh); 2566 jbd_unlock_bh_journal_head(bh); 2567 __brelse(bh); 2568 } else 2569 jbd_unlock_bh_journal_head(bh); 2570 } 2571 2572 /* 2573 * Initialize jbd inode head 2574 */ 2575 void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode) 2576 { 2577 jinode->i_transaction = NULL; 2578 jinode->i_next_transaction = NULL; 2579 jinode->i_vfs_inode = inode; 2580 jinode->i_flags = 0; 2581 INIT_LIST_HEAD(&jinode->i_list); 2582 } 2583 2584 /* 2585 * Function to be called before we start removing inode from memory (i.e., 2586 * clear_inode() is a fine place to be called from). It removes inode from 2587 * transaction's lists. 2588 */ 2589 void jbd2_journal_release_jbd_inode(journal_t *journal, 2590 struct jbd2_inode *jinode) 2591 { 2592 if (!journal) 2593 return; 2594 restart: 2595 spin_lock(&journal->j_list_lock); 2596 /* Is commit writing out inode - we have to wait */ 2597 if (jinode->i_flags & JI_COMMIT_RUNNING) { 2598 wait_queue_head_t *wq; 2599 DEFINE_WAIT_BIT(wait, &jinode->i_flags, __JI_COMMIT_RUNNING); 2600 wq = bit_waitqueue(&jinode->i_flags, __JI_COMMIT_RUNNING); 2601 prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE); 2602 spin_unlock(&journal->j_list_lock); 2603 schedule(); 2604 finish_wait(wq, &wait.wait); 2605 goto restart; 2606 } 2607 2608 if (jinode->i_transaction) { 2609 list_del(&jinode->i_list); 2610 jinode->i_transaction = NULL; 2611 } 2612 spin_unlock(&journal->j_list_lock); 2613 } 2614 2615 2616 #ifdef CONFIG_PROC_FS 2617 2618 #define JBD2_STATS_PROC_NAME "fs/jbd2" 2619 2620 static void __init jbd2_create_jbd_stats_proc_entry(void) 2621 { 2622 proc_jbd2_stats = proc_mkdir(JBD2_STATS_PROC_NAME, NULL); 2623 } 2624 2625 static void __exit jbd2_remove_jbd_stats_proc_entry(void) 2626 { 2627 if (proc_jbd2_stats) 2628 remove_proc_entry(JBD2_STATS_PROC_NAME, NULL); 2629 } 2630 2631 #else 2632 2633 #define jbd2_create_jbd_stats_proc_entry() do {} while (0) 2634 #define jbd2_remove_jbd_stats_proc_entry() do {} while (0) 2635 2636 #endif 2637 2638 struct kmem_cache *jbd2_handle_cache, *jbd2_inode_cache; 2639 2640 static int __init jbd2_journal_init_handle_cache(void) 2641 { 2642 jbd2_handle_cache = KMEM_CACHE(jbd2_journal_handle, SLAB_TEMPORARY); 2643 if (jbd2_handle_cache == NULL) { 2644 printk(KERN_EMERG "JBD2: failed to create handle cache\n"); 2645 return -ENOMEM; 2646 } 2647 jbd2_inode_cache = KMEM_CACHE(jbd2_inode, 0); 2648 if (jbd2_inode_cache == NULL) { 2649 printk(KERN_EMERG "JBD2: failed to create inode cache\n"); 2650 kmem_cache_destroy(jbd2_handle_cache); 2651 return -ENOMEM; 2652 } 2653 return 0; 2654 } 2655 2656 static void jbd2_journal_destroy_handle_cache(void) 2657 { 2658 if (jbd2_handle_cache) 2659 kmem_cache_destroy(jbd2_handle_cache); 2660 if (jbd2_inode_cache) 2661 kmem_cache_destroy(jbd2_inode_cache); 2662 2663 } 2664 2665 /* 2666 * Module startup and shutdown 2667 */ 2668 2669 static int __init journal_init_caches(void) 2670 { 2671 int ret; 2672 2673 ret = jbd2_journal_init_revoke_caches(); 2674 if (ret == 0) 2675 ret = jbd2_journal_init_journal_head_cache(); 2676 if (ret == 0) 2677 ret = jbd2_journal_init_handle_cache(); 2678 if (ret == 0) 2679 ret = jbd2_journal_init_transaction_cache(); 2680 return ret; 2681 } 2682 2683 static void jbd2_journal_destroy_caches(void) 2684 { 2685 jbd2_journal_destroy_revoke_caches(); 2686 jbd2_journal_destroy_journal_head_cache(); 2687 jbd2_journal_destroy_handle_cache(); 2688 jbd2_journal_destroy_transaction_cache(); 2689 jbd2_journal_destroy_slabs(); 2690 } 2691 2692 static int __init journal_init(void) 2693 { 2694 int ret; 2695 2696 BUILD_BUG_ON(sizeof(struct journal_superblock_s) != 1024); 2697 2698 ret = journal_init_caches(); 2699 if (ret == 0) { 2700 jbd2_create_jbd_stats_proc_entry(); 2701 } else { 2702 jbd2_journal_destroy_caches(); 2703 } 2704 return ret; 2705 } 2706 2707 static void __exit journal_exit(void) 2708 { 2709 #ifdef CONFIG_JBD2_DEBUG 2710 int n = atomic_read(&nr_journal_heads); 2711 if (n) 2712 printk(KERN_ERR "JBD2: leaked %d journal_heads!\n", n); 2713 #endif 2714 jbd2_remove_jbd_stats_proc_entry(); 2715 jbd2_journal_destroy_caches(); 2716 } 2717 2718 MODULE_LICENSE("GPL"); 2719 module_init(journal_init); 2720 module_exit(journal_exit); 2721 2722