1 // SPDX-License-Identifier: GPL-2.0+
3 * linux/fs/jbd2/journal.c
5 * Written by Stephen C. Tweedie <sct@redhat.com>, 1998
7 * Copyright 1998 Red Hat corp --- All Rights Reserved
9 * Generic filesystem journal-writing code; part of the ext2fs
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.
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).
22 #include <linux/module.h>
23 #include <linux/time.h>
25 #include <linux/jbd2.h>
26 #include <linux/errno.h>
27 #include <linux/slab.h>
28 #include <linux/init.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>
45 #define CREATE_TRACE_POINTS
46 #include <trace/events/jbd2.h>
48 #include <linux/uaccess.h>
51 #ifdef CONFIG_JBD2_DEBUG
52 ushort jbd2_journal_enable_debug __read_mostly;
53 EXPORT_SYMBOL(jbd2_journal_enable_debug);
55 module_param_named(jbd2_debug, jbd2_journal_enable_debug, ushort, 0644);
56 MODULE_PARM_DESC(jbd2_debug, "Debugging level for jbd2");
59 EXPORT_SYMBOL(jbd2_journal_extend);
60 EXPORT_SYMBOL(jbd2_journal_stop);
61 EXPORT_SYMBOL(jbd2_journal_lock_updates);
62 EXPORT_SYMBOL(jbd2_journal_unlock_updates);
63 EXPORT_SYMBOL(jbd2_journal_get_write_access);
64 EXPORT_SYMBOL(jbd2_journal_get_create_access);
65 EXPORT_SYMBOL(jbd2_journal_get_undo_access);
66 EXPORT_SYMBOL(jbd2_journal_set_triggers);
67 EXPORT_SYMBOL(jbd2_journal_dirty_metadata);
68 EXPORT_SYMBOL(jbd2_journal_forget);
69 EXPORT_SYMBOL(jbd2_journal_flush);
70 EXPORT_SYMBOL(jbd2_journal_revoke);
72 EXPORT_SYMBOL(jbd2_journal_init_dev);
73 EXPORT_SYMBOL(jbd2_journal_init_inode);
74 EXPORT_SYMBOL(jbd2_journal_check_used_features);
75 EXPORT_SYMBOL(jbd2_journal_check_available_features);
76 EXPORT_SYMBOL(jbd2_journal_set_features);
77 EXPORT_SYMBOL(jbd2_journal_load);
78 EXPORT_SYMBOL(jbd2_journal_destroy);
79 EXPORT_SYMBOL(jbd2_journal_abort);
80 EXPORT_SYMBOL(jbd2_journal_errno);
81 EXPORT_SYMBOL(jbd2_journal_ack_err);
82 EXPORT_SYMBOL(jbd2_journal_clear_err);
83 EXPORT_SYMBOL(jbd2_log_wait_commit);
84 EXPORT_SYMBOL(jbd2_log_start_commit);
85 EXPORT_SYMBOL(jbd2_journal_start_commit);
86 EXPORT_SYMBOL(jbd2_journal_force_commit_nested);
87 EXPORT_SYMBOL(jbd2_journal_wipe);
88 EXPORT_SYMBOL(jbd2_journal_blocks_per_page);
89 EXPORT_SYMBOL(jbd2_journal_invalidatepage);
90 EXPORT_SYMBOL(jbd2_journal_try_to_free_buffers);
91 EXPORT_SYMBOL(jbd2_journal_force_commit);
92 EXPORT_SYMBOL(jbd2_journal_inode_ranged_write);
93 EXPORT_SYMBOL(jbd2_journal_inode_ranged_wait);
94 EXPORT_SYMBOL(jbd2_journal_submit_inode_data_buffers);
95 EXPORT_SYMBOL(jbd2_journal_finish_inode_data_buffers);
96 EXPORT_SYMBOL(jbd2_journal_init_jbd_inode);
97 EXPORT_SYMBOL(jbd2_journal_release_jbd_inode);
98 EXPORT_SYMBOL(jbd2_journal_begin_ordered_truncate);
99 EXPORT_SYMBOL(jbd2_inode_cache);
101 static int jbd2_journal_create_slab(size_t slab_size);
103 #ifdef CONFIG_JBD2_DEBUG
104 void __jbd2_debug(int level, const char *file, const char *func,
105 unsigned int line, const char *fmt, ...)
107 struct va_format vaf;
110 if (level > jbd2_journal_enable_debug)
115 printk(KERN_DEBUG "%s: (%s, %u): %pV", file, func, line, &vaf);
118 EXPORT_SYMBOL(__jbd2_debug);
121 /* Checksumming functions */
122 static int jbd2_verify_csum_type(journal_t *j, journal_superblock_t *sb)
124 if (!jbd2_journal_has_csum_v2or3_feature(j))
127 return sb->s_checksum_type == JBD2_CRC32C_CHKSUM;
130 static __be32 jbd2_superblock_csum(journal_t *j, journal_superblock_t *sb)
135 old_csum = sb->s_checksum;
137 csum = jbd2_chksum(j, ~0, (char *)sb, sizeof(journal_superblock_t));
138 sb->s_checksum = old_csum;
140 return cpu_to_be32(csum);
144 * Helper function used to manage commit timeouts
147 static void commit_timeout(struct timer_list *t)
149 journal_t *journal = from_timer(journal, t, j_commit_timer);
151 wake_up_process(journal->j_task);
155 * kjournald2: The main thread function used to manage a logging device
158 * This kernel thread is responsible for two things:
160 * 1) COMMIT: Every so often we need to commit the current state of the
161 * filesystem to disk. The journal thread is responsible for writing
162 * all of the metadata buffers to disk. If a fast commit is ongoing
163 * journal thread waits until it's done and then continues from
166 * 2) CHECKPOINT: We cannot reuse a used section of the log file until all
167 * of the data in that part of the log has been rewritten elsewhere on
168 * the disk. Flushing these old buffers to reclaim space in the log is
169 * known as checkpointing, and this thread is responsible for that job.
172 static int kjournald2(void *arg)
174 journal_t *journal = arg;
175 transaction_t *transaction;
178 * Set up an interval timer which can be used to trigger a commit wakeup
179 * after the commit interval expires
181 timer_setup(&journal->j_commit_timer, commit_timeout, 0);
185 /* Record that the journal thread is running */
186 journal->j_task = current;
187 wake_up(&journal->j_wait_done_commit);
190 * Make sure that no allocations from this kernel thread will ever
191 * recurse to the fs layer because we are responsible for the
192 * transaction commit and any fs involvement might get stuck waiting for
195 memalloc_nofs_save();
198 * And now, wait forever for commit wakeup events.
200 write_lock(&journal->j_state_lock);
203 if (journal->j_flags & JBD2_UNMOUNT)
206 jbd_debug(1, "commit_sequence=%u, commit_request=%u\n",
207 journal->j_commit_sequence, journal->j_commit_request);
209 if (journal->j_commit_sequence != journal->j_commit_request) {
210 jbd_debug(1, "OK, requests differ\n");
211 write_unlock(&journal->j_state_lock);
212 del_timer_sync(&journal->j_commit_timer);
213 jbd2_journal_commit_transaction(journal);
214 write_lock(&journal->j_state_lock);
218 wake_up(&journal->j_wait_done_commit);
219 if (freezing(current)) {
221 * The simpler the better. Flushing journal isn't a
222 * good idea, because that depends on threads that may
223 * be already stopped.
225 jbd_debug(1, "Now suspending kjournald2\n");
226 write_unlock(&journal->j_state_lock);
228 write_lock(&journal->j_state_lock);
231 * We assume on resume that commits are already there,
235 int should_sleep = 1;
237 prepare_to_wait(&journal->j_wait_commit, &wait,
239 if (journal->j_commit_sequence != journal->j_commit_request)
241 transaction = journal->j_running_transaction;
242 if (transaction && time_after_eq(jiffies,
243 transaction->t_expires))
245 if (journal->j_flags & JBD2_UNMOUNT)
248 write_unlock(&journal->j_state_lock);
250 write_lock(&journal->j_state_lock);
252 finish_wait(&journal->j_wait_commit, &wait);
255 jbd_debug(1, "kjournald2 wakes\n");
258 * Were we woken up by a commit wakeup event?
260 transaction = journal->j_running_transaction;
261 if (transaction && time_after_eq(jiffies, transaction->t_expires)) {
262 journal->j_commit_request = transaction->t_tid;
263 jbd_debug(1, "woke because of timeout\n");
268 del_timer_sync(&journal->j_commit_timer);
269 journal->j_task = NULL;
270 wake_up(&journal->j_wait_done_commit);
271 jbd_debug(1, "Journal thread exiting.\n");
272 write_unlock(&journal->j_state_lock);
276 static int jbd2_journal_start_thread(journal_t *journal)
278 struct task_struct *t;
280 t = kthread_run(kjournald2, journal, "jbd2/%s",
285 wait_event(journal->j_wait_done_commit, journal->j_task != NULL);
289 static void journal_kill_thread(journal_t *journal)
291 write_lock(&journal->j_state_lock);
292 journal->j_flags |= JBD2_UNMOUNT;
294 while (journal->j_task) {
295 write_unlock(&journal->j_state_lock);
296 wake_up(&journal->j_wait_commit);
297 wait_event(journal->j_wait_done_commit, journal->j_task == NULL);
298 write_lock(&journal->j_state_lock);
300 write_unlock(&journal->j_state_lock);
304 * jbd2_journal_write_metadata_buffer: write a metadata buffer to the journal.
306 * Writes a metadata buffer to a given disk block. The actual IO is not
307 * performed but a new buffer_head is constructed which labels the data
308 * to be written with the correct destination disk block.
310 * Any magic-number escaping which needs to be done will cause a
311 * copy-out here. If the buffer happens to start with the
312 * JBD2_MAGIC_NUMBER, then we can't write it to the log directly: the
313 * magic number is only written to the log for descripter blocks. In
314 * this case, we copy the data and replace the first word with 0, and we
315 * return a result code which indicates that this buffer needs to be
316 * marked as an escaped buffer in the corresponding log descriptor
317 * block. The missing word can then be restored when the block is read
320 * If the source buffer has already been modified by a new transaction
321 * since we took the last commit snapshot, we use the frozen copy of
322 * that data for IO. If we end up using the existing buffer_head's data
323 * for the write, then we have to make sure nobody modifies it while the
324 * IO is in progress. do_get_write_access() handles this.
326 * The function returns a pointer to the buffer_head to be used for IO.
334 * Bit 0 set == escape performed on the data
335 * Bit 1 set == buffer copy-out performed (kfree the data after IO)
338 int jbd2_journal_write_metadata_buffer(transaction_t *transaction,
339 struct journal_head *jh_in,
340 struct buffer_head **bh_out,
343 int need_copy_out = 0;
344 int done_copy_out = 0;
347 struct buffer_head *new_bh;
348 struct page *new_page;
349 unsigned int new_offset;
350 struct buffer_head *bh_in = jh2bh(jh_in);
351 journal_t *journal = transaction->t_journal;
354 * The buffer really shouldn't be locked: only the current committing
355 * transaction is allowed to write it, so nobody else is allowed
358 * akpm: except if we're journalling data, and write() output is
359 * also part of a shared mapping, and another thread has
360 * decided to launch a writepage() against this buffer.
362 J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in));
364 new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL);
366 /* keep subsequent assertions sane */
367 atomic_set(&new_bh->b_count, 1);
369 spin_lock(&jh_in->b_state_lock);
372 * If a new transaction has already done a buffer copy-out, then
373 * we use that version of the data for the commit.
375 if (jh_in->b_frozen_data) {
377 new_page = virt_to_page(jh_in->b_frozen_data);
378 new_offset = offset_in_page(jh_in->b_frozen_data);
380 new_page = jh2bh(jh_in)->b_page;
381 new_offset = offset_in_page(jh2bh(jh_in)->b_data);
384 mapped_data = kmap_atomic(new_page);
386 * Fire data frozen trigger if data already wasn't frozen. Do this
387 * before checking for escaping, as the trigger may modify the magic
388 * offset. If a copy-out happens afterwards, it will have the correct
389 * data in the buffer.
392 jbd2_buffer_frozen_trigger(jh_in, mapped_data + new_offset,
398 if (*((__be32 *)(mapped_data + new_offset)) ==
399 cpu_to_be32(JBD2_MAGIC_NUMBER)) {
403 kunmap_atomic(mapped_data);
406 * Do we need to do a data copy?
408 if (need_copy_out && !done_copy_out) {
411 spin_unlock(&jh_in->b_state_lock);
412 tmp = jbd2_alloc(bh_in->b_size, GFP_NOFS);
417 spin_lock(&jh_in->b_state_lock);
418 if (jh_in->b_frozen_data) {
419 jbd2_free(tmp, bh_in->b_size);
423 jh_in->b_frozen_data = tmp;
424 mapped_data = kmap_atomic(new_page);
425 memcpy(tmp, mapped_data + new_offset, bh_in->b_size);
426 kunmap_atomic(mapped_data);
428 new_page = virt_to_page(tmp);
429 new_offset = offset_in_page(tmp);
433 * This isn't strictly necessary, as we're using frozen
434 * data for the escaping, but it keeps consistency with
435 * b_frozen_data usage.
437 jh_in->b_frozen_triggers = jh_in->b_triggers;
441 * Did we need to do an escaping? Now we've done all the
442 * copying, we can finally do so.
445 mapped_data = kmap_atomic(new_page);
446 *((unsigned int *)(mapped_data + new_offset)) = 0;
447 kunmap_atomic(mapped_data);
450 set_bh_page(new_bh, new_page, new_offset);
451 new_bh->b_size = bh_in->b_size;
452 new_bh->b_bdev = journal->j_dev;
453 new_bh->b_blocknr = blocknr;
454 new_bh->b_private = bh_in;
455 set_buffer_mapped(new_bh);
456 set_buffer_dirty(new_bh);
461 * The to-be-written buffer needs to get moved to the io queue,
462 * and the original buffer whose contents we are shadowing or
463 * copying is moved to the transaction's shadow queue.
465 JBUFFER_TRACE(jh_in, "file as BJ_Shadow");
466 spin_lock(&journal->j_list_lock);
467 __jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow);
468 spin_unlock(&journal->j_list_lock);
469 set_buffer_shadow(bh_in);
470 spin_unlock(&jh_in->b_state_lock);
472 return do_escape | (done_copy_out << 1);
476 * Allocation code for the journal file. Manage the space left in the
477 * journal, so that we can begin checkpointing when appropriate.
481 * Called with j_state_lock locked for writing.
482 * Returns true if a transaction commit was started.
484 int __jbd2_log_start_commit(journal_t *journal, tid_t target)
486 /* Return if the txn has already requested to be committed */
487 if (journal->j_commit_request == target)
491 * The only transaction we can possibly wait upon is the
492 * currently running transaction (if it exists). Otherwise,
493 * the target tid must be an old one.
495 if (journal->j_running_transaction &&
496 journal->j_running_transaction->t_tid == target) {
498 * We want a new commit: OK, mark the request and wakeup the
499 * commit thread. We do _not_ do the commit ourselves.
502 journal->j_commit_request = target;
503 jbd_debug(1, "JBD2: requesting commit %u/%u\n",
504 journal->j_commit_request,
505 journal->j_commit_sequence);
506 journal->j_running_transaction->t_requested = jiffies;
507 wake_up(&journal->j_wait_commit);
509 } else if (!tid_geq(journal->j_commit_request, target))
510 /* This should never happen, but if it does, preserve
511 the evidence before kjournald goes into a loop and
512 increments j_commit_sequence beyond all recognition. */
513 WARN_ONCE(1, "JBD2: bad log_start_commit: %u %u %u %u\n",
514 journal->j_commit_request,
515 journal->j_commit_sequence,
516 target, journal->j_running_transaction ?
517 journal->j_running_transaction->t_tid : 0);
521 int jbd2_log_start_commit(journal_t *journal, tid_t tid)
525 write_lock(&journal->j_state_lock);
526 ret = __jbd2_log_start_commit(journal, tid);
527 write_unlock(&journal->j_state_lock);
532 * Force and wait any uncommitted transactions. We can only force the running
533 * transaction if we don't have an active handle, otherwise, we will deadlock.
534 * Returns: <0 in case of error,
535 * 0 if nothing to commit,
536 * 1 if transaction was successfully committed.
538 static int __jbd2_journal_force_commit(journal_t *journal)
540 transaction_t *transaction = NULL;
542 int need_to_start = 0, ret = 0;
544 read_lock(&journal->j_state_lock);
545 if (journal->j_running_transaction && !current->journal_info) {
546 transaction = journal->j_running_transaction;
547 if (!tid_geq(journal->j_commit_request, transaction->t_tid))
549 } else if (journal->j_committing_transaction)
550 transaction = journal->j_committing_transaction;
553 /* Nothing to commit */
554 read_unlock(&journal->j_state_lock);
557 tid = transaction->t_tid;
558 read_unlock(&journal->j_state_lock);
560 jbd2_log_start_commit(journal, tid);
561 ret = jbd2_log_wait_commit(journal, tid);
569 * jbd2_journal_force_commit_nested - Force and wait upon a commit if the
570 * calling process is not within transaction.
572 * @journal: journal to force
573 * Returns true if progress was made.
575 * This is used for forcing out undo-protected data which contains
576 * bitmaps, when the fs is running out of space.
578 int jbd2_journal_force_commit_nested(journal_t *journal)
582 ret = __jbd2_journal_force_commit(journal);
587 * jbd2_journal_force_commit() - force any uncommitted transactions
588 * @journal: journal to force
590 * Caller want unconditional commit. We can only force the running transaction
591 * if we don't have an active handle, otherwise, we will deadlock.
593 int jbd2_journal_force_commit(journal_t *journal)
597 J_ASSERT(!current->journal_info);
598 ret = __jbd2_journal_force_commit(journal);
605 * Start a commit of the current running transaction (if any). Returns true
606 * if a transaction is going to be committed (or is currently already
607 * committing), and fills its tid in at *ptid
609 int jbd2_journal_start_commit(journal_t *journal, tid_t *ptid)
613 write_lock(&journal->j_state_lock);
614 if (journal->j_running_transaction) {
615 tid_t tid = journal->j_running_transaction->t_tid;
617 __jbd2_log_start_commit(journal, tid);
618 /* There's a running transaction and we've just made sure
619 * it's commit has been scheduled. */
623 } else if (journal->j_committing_transaction) {
625 * If commit has been started, then we have to wait for
626 * completion of that transaction.
629 *ptid = journal->j_committing_transaction->t_tid;
632 write_unlock(&journal->j_state_lock);
637 * Return 1 if a given transaction has not yet sent barrier request
638 * connected with a transaction commit. If 0 is returned, transaction
639 * may or may not have sent the barrier. Used to avoid sending barrier
640 * twice in common cases.
642 int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid)
645 transaction_t *commit_trans;
647 if (!(journal->j_flags & JBD2_BARRIER))
649 read_lock(&journal->j_state_lock);
650 /* Transaction already committed? */
651 if (tid_geq(journal->j_commit_sequence, tid))
653 commit_trans = journal->j_committing_transaction;
654 if (!commit_trans || commit_trans->t_tid != tid) {
659 * Transaction is being committed and we already proceeded to
660 * submitting a flush to fs partition?
662 if (journal->j_fs_dev != journal->j_dev) {
663 if (!commit_trans->t_need_data_flush ||
664 commit_trans->t_state >= T_COMMIT_DFLUSH)
667 if (commit_trans->t_state >= T_COMMIT_JFLUSH)
672 read_unlock(&journal->j_state_lock);
675 EXPORT_SYMBOL(jbd2_trans_will_send_data_barrier);
678 * Wait for a specified commit to complete.
679 * The caller may not hold the journal lock.
681 int jbd2_log_wait_commit(journal_t *journal, tid_t tid)
685 read_lock(&journal->j_state_lock);
686 #ifdef CONFIG_PROVE_LOCKING
688 * Some callers make sure transaction is already committing and in that
689 * case we cannot block on open handles anymore. So don't warn in that
692 if (tid_gt(tid, journal->j_commit_sequence) &&
693 (!journal->j_committing_transaction ||
694 journal->j_committing_transaction->t_tid != tid)) {
695 read_unlock(&journal->j_state_lock);
696 jbd2_might_wait_for_commit(journal);
697 read_lock(&journal->j_state_lock);
700 #ifdef CONFIG_JBD2_DEBUG
701 if (!tid_geq(journal->j_commit_request, tid)) {
703 "%s: error: j_commit_request=%u, tid=%u\n",
704 __func__, journal->j_commit_request, tid);
707 while (tid_gt(tid, journal->j_commit_sequence)) {
708 jbd_debug(1, "JBD2: want %u, j_commit_sequence=%u\n",
709 tid, journal->j_commit_sequence);
710 read_unlock(&journal->j_state_lock);
711 wake_up(&journal->j_wait_commit);
712 wait_event(journal->j_wait_done_commit,
713 !tid_gt(tid, journal->j_commit_sequence));
714 read_lock(&journal->j_state_lock);
716 read_unlock(&journal->j_state_lock);
718 if (unlikely(is_journal_aborted(journal)))
724 * Start a fast commit. If there's an ongoing fast or full commit wait for
725 * it to complete. Returns 0 if a new fast commit was started. Returns -EALREADY
726 * if a fast commit is not needed, either because there's an already a commit
727 * going on or this tid has already been committed. Returns -EINVAL if no jbd2
728 * commit has yet been performed.
730 int jbd2_fc_begin_commit(journal_t *journal, tid_t tid)
732 if (unlikely(is_journal_aborted(journal)))
735 * Fast commits only allowed if at least one full commit has
738 if (!journal->j_stats.ts_tid)
741 write_lock(&journal->j_state_lock);
742 if (tid <= journal->j_commit_sequence) {
743 write_unlock(&journal->j_state_lock);
747 if (journal->j_flags & JBD2_FULL_COMMIT_ONGOING ||
748 (journal->j_flags & JBD2_FAST_COMMIT_ONGOING)) {
751 prepare_to_wait(&journal->j_fc_wait, &wait,
752 TASK_UNINTERRUPTIBLE);
753 write_unlock(&journal->j_state_lock);
755 finish_wait(&journal->j_fc_wait, &wait);
758 journal->j_flags |= JBD2_FAST_COMMIT_ONGOING;
759 write_unlock(&journal->j_state_lock);
763 EXPORT_SYMBOL(jbd2_fc_begin_commit);
766 * Stop a fast commit. If fallback is set, this function starts commit of
767 * TID tid before any other fast commit can start.
769 static int __jbd2_fc_end_commit(journal_t *journal, tid_t tid, bool fallback)
771 if (journal->j_fc_cleanup_callback)
772 journal->j_fc_cleanup_callback(journal, 0);
773 write_lock(&journal->j_state_lock);
774 journal->j_flags &= ~JBD2_FAST_COMMIT_ONGOING;
776 journal->j_flags |= JBD2_FULL_COMMIT_ONGOING;
777 write_unlock(&journal->j_state_lock);
778 wake_up(&journal->j_fc_wait);
780 return jbd2_complete_transaction(journal, tid);
784 int jbd2_fc_end_commit(journal_t *journal)
786 return __jbd2_fc_end_commit(journal, 0, false);
788 EXPORT_SYMBOL(jbd2_fc_end_commit);
790 int jbd2_fc_end_commit_fallback(journal_t *journal)
794 read_lock(&journal->j_state_lock);
795 tid = journal->j_running_transaction ?
796 journal->j_running_transaction->t_tid : 0;
797 read_unlock(&journal->j_state_lock);
798 return __jbd2_fc_end_commit(journal, tid, true);
800 EXPORT_SYMBOL(jbd2_fc_end_commit_fallback);
802 /* Return 1 when transaction with given tid has already committed. */
803 int jbd2_transaction_committed(journal_t *journal, tid_t tid)
807 read_lock(&journal->j_state_lock);
808 if (journal->j_running_transaction &&
809 journal->j_running_transaction->t_tid == tid)
811 if (journal->j_committing_transaction &&
812 journal->j_committing_transaction->t_tid == tid)
814 read_unlock(&journal->j_state_lock);
817 EXPORT_SYMBOL(jbd2_transaction_committed);
820 * When this function returns the transaction corresponding to tid
821 * will be completed. If the transaction has currently running, start
822 * committing that transaction before waiting for it to complete. If
823 * the transaction id is stale, it is by definition already completed,
824 * so just return SUCCESS.
826 int jbd2_complete_transaction(journal_t *journal, tid_t tid)
828 int need_to_wait = 1;
830 read_lock(&journal->j_state_lock);
831 if (journal->j_running_transaction &&
832 journal->j_running_transaction->t_tid == tid) {
833 if (journal->j_commit_request != tid) {
834 /* transaction not yet started, so request it */
835 read_unlock(&journal->j_state_lock);
836 jbd2_log_start_commit(journal, tid);
839 } else if (!(journal->j_committing_transaction &&
840 journal->j_committing_transaction->t_tid == tid))
842 read_unlock(&journal->j_state_lock);
846 return jbd2_log_wait_commit(journal, tid);
848 EXPORT_SYMBOL(jbd2_complete_transaction);
851 * Log buffer allocation routines:
854 int jbd2_journal_next_log_block(journal_t *journal, unsigned long long *retp)
856 unsigned long blocknr;
858 write_lock(&journal->j_state_lock);
859 J_ASSERT(journal->j_free > 1);
861 blocknr = journal->j_head;
864 if (journal->j_head == journal->j_last)
865 journal->j_head = journal->j_first;
866 write_unlock(&journal->j_state_lock);
867 return jbd2_journal_bmap(journal, blocknr, retp);
870 /* Map one fast commit buffer for use by the file system */
871 int jbd2_fc_get_buf(journal_t *journal, struct buffer_head **bh_out)
873 unsigned long long pblock;
874 unsigned long blocknr;
876 struct buffer_head *bh;
881 if (journal->j_fc_off + journal->j_fc_first < journal->j_fc_last) {
882 fc_off = journal->j_fc_off;
883 blocknr = journal->j_fc_first + fc_off;
892 ret = jbd2_journal_bmap(journal, blocknr, &pblock);
896 bh = __getblk(journal->j_dev, pblock, journal->j_blocksize);
901 journal->j_fc_wbuf[fc_off] = bh;
907 EXPORT_SYMBOL(jbd2_fc_get_buf);
910 * Wait on fast commit buffers that were allocated by jbd2_fc_get_buf
913 int jbd2_fc_wait_bufs(journal_t *journal, int num_blks)
915 struct buffer_head *bh;
918 j_fc_off = journal->j_fc_off;
921 * Wait in reverse order to minimize chances of us being woken up before
922 * all IOs have completed
924 for (i = j_fc_off - 1; i >= j_fc_off - num_blks; i--) {
925 bh = journal->j_fc_wbuf[i];
928 * Update j_fc_off so jbd2_fc_release_bufs can release remain
931 if (unlikely(!buffer_uptodate(bh))) {
932 journal->j_fc_off = i + 1;
936 journal->j_fc_wbuf[i] = NULL;
941 EXPORT_SYMBOL(jbd2_fc_wait_bufs);
944 * Wait on fast commit buffers that were allocated by jbd2_fc_get_buf
947 int jbd2_fc_release_bufs(journal_t *journal)
949 struct buffer_head *bh;
952 j_fc_off = journal->j_fc_off;
955 * Wait in reverse order to minimize chances of us being woken up before
956 * all IOs have completed
958 for (i = j_fc_off - 1; i >= 0; i--) {
959 bh = journal->j_fc_wbuf[i];
963 journal->j_fc_wbuf[i] = NULL;
968 EXPORT_SYMBOL(jbd2_fc_release_bufs);
971 * Conversion of logical to physical block numbers for the journal
973 * On external journals the journal blocks are identity-mapped, so
974 * this is a no-op. If needed, we can use j_blk_offset - everything is
977 int jbd2_journal_bmap(journal_t *journal, unsigned long blocknr,
978 unsigned long long *retp)
981 unsigned long long ret;
984 if (journal->j_inode) {
986 ret = bmap(journal->j_inode, &block);
989 printk(KERN_ALERT "%s: journal block not found "
990 "at offset %lu on %s\n",
991 __func__, blocknr, journal->j_devname);
993 jbd2_journal_abort(journal, err);
999 *retp = blocknr; /* +journal->j_blk_offset */
1005 * We play buffer_head aliasing tricks to write data/metadata blocks to
1006 * the journal without copying their contents, but for journal
1007 * descriptor blocks we do need to generate bona fide buffers.
1009 * After the caller of jbd2_journal_get_descriptor_buffer() has finished modifying
1010 * the buffer's contents they really should run flush_dcache_page(bh->b_page).
1011 * But we don't bother doing that, so there will be coherency problems with
1012 * mmaps of blockdevs which hold live JBD-controlled filesystems.
1014 struct buffer_head *
1015 jbd2_journal_get_descriptor_buffer(transaction_t *transaction, int type)
1017 journal_t *journal = transaction->t_journal;
1018 struct buffer_head *bh;
1019 unsigned long long blocknr;
1020 journal_header_t *header;
1023 err = jbd2_journal_next_log_block(journal, &blocknr);
1028 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
1031 atomic_dec(&transaction->t_outstanding_credits);
1033 memset(bh->b_data, 0, journal->j_blocksize);
1034 header = (journal_header_t *)bh->b_data;
1035 header->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER);
1036 header->h_blocktype = cpu_to_be32(type);
1037 header->h_sequence = cpu_to_be32(transaction->t_tid);
1038 set_buffer_uptodate(bh);
1040 BUFFER_TRACE(bh, "return this buffer");
1044 void jbd2_descriptor_block_csum_set(journal_t *j, struct buffer_head *bh)
1046 struct jbd2_journal_block_tail *tail;
1049 if (!jbd2_journal_has_csum_v2or3(j))
1052 tail = (struct jbd2_journal_block_tail *)(bh->b_data + j->j_blocksize -
1053 sizeof(struct jbd2_journal_block_tail));
1054 tail->t_checksum = 0;
1055 csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize);
1056 tail->t_checksum = cpu_to_be32(csum);
1060 * Return tid of the oldest transaction in the journal and block in the journal
1061 * where the transaction starts.
1063 * If the journal is now empty, return which will be the next transaction ID
1064 * we will write and where will that transaction start.
1066 * The return value is 0 if journal tail cannot be pushed any further, 1 if
1069 int jbd2_journal_get_log_tail(journal_t *journal, tid_t *tid,
1070 unsigned long *block)
1072 transaction_t *transaction;
1075 read_lock(&journal->j_state_lock);
1076 spin_lock(&journal->j_list_lock);
1077 transaction = journal->j_checkpoint_transactions;
1079 *tid = transaction->t_tid;
1080 *block = transaction->t_log_start;
1081 } else if ((transaction = journal->j_committing_transaction) != NULL) {
1082 *tid = transaction->t_tid;
1083 *block = transaction->t_log_start;
1084 } else if ((transaction = journal->j_running_transaction) != NULL) {
1085 *tid = transaction->t_tid;
1086 *block = journal->j_head;
1088 *tid = journal->j_transaction_sequence;
1089 *block = journal->j_head;
1091 ret = tid_gt(*tid, journal->j_tail_sequence);
1092 spin_unlock(&journal->j_list_lock);
1093 read_unlock(&journal->j_state_lock);
1099 * Update information in journal structure and in on disk journal superblock
1100 * about log tail. This function does not check whether information passed in
1101 * really pushes log tail further. It's responsibility of the caller to make
1102 * sure provided log tail information is valid (e.g. by holding
1103 * j_checkpoint_mutex all the time between computing log tail and calling this
1104 * function as is the case with jbd2_cleanup_journal_tail()).
1106 * Requires j_checkpoint_mutex
1108 int __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block)
1110 unsigned long freed;
1113 BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
1116 * We cannot afford for write to remain in drive's caches since as
1117 * soon as we update j_tail, next transaction can start reusing journal
1118 * space and if we lose sb update during power failure we'd replay
1119 * old transaction with possibly newly overwritten data.
1121 ret = jbd2_journal_update_sb_log_tail(journal, tid, block,
1122 REQ_SYNC | REQ_FUA);
1126 write_lock(&journal->j_state_lock);
1127 freed = block - journal->j_tail;
1128 if (block < journal->j_tail)
1129 freed += journal->j_last - journal->j_first;
1131 trace_jbd2_update_log_tail(journal, tid, block, freed);
1133 "Cleaning journal tail from %u to %u (offset %lu), "
1135 journal->j_tail_sequence, tid, block, freed);
1137 journal->j_free += freed;
1138 journal->j_tail_sequence = tid;
1139 journal->j_tail = block;
1140 write_unlock(&journal->j_state_lock);
1147 * This is a variation of __jbd2_update_log_tail which checks for validity of
1148 * provided log tail and locks j_checkpoint_mutex. So it is safe against races
1149 * with other threads updating log tail.
1151 void jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block)
1153 mutex_lock_io(&journal->j_checkpoint_mutex);
1154 if (tid_gt(tid, journal->j_tail_sequence))
1155 __jbd2_update_log_tail(journal, tid, block);
1156 mutex_unlock(&journal->j_checkpoint_mutex);
1159 struct jbd2_stats_proc_session {
1161 struct transaction_stats_s *stats;
1166 static void *jbd2_seq_info_start(struct seq_file *seq, loff_t *pos)
1168 return *pos ? NULL : SEQ_START_TOKEN;
1171 static void *jbd2_seq_info_next(struct seq_file *seq, void *v, loff_t *pos)
1177 static int jbd2_seq_info_show(struct seq_file *seq, void *v)
1179 struct jbd2_stats_proc_session *s = seq->private;
1181 if (v != SEQ_START_TOKEN)
1183 seq_printf(seq, "%lu transactions (%lu requested), "
1184 "each up to %u blocks\n",
1185 s->stats->ts_tid, s->stats->ts_requested,
1186 s->journal->j_max_transaction_buffers);
1187 if (s->stats->ts_tid == 0)
1189 seq_printf(seq, "average: \n %ums waiting for transaction\n",
1190 jiffies_to_msecs(s->stats->run.rs_wait / s->stats->ts_tid));
1191 seq_printf(seq, " %ums request delay\n",
1192 (s->stats->ts_requested == 0) ? 0 :
1193 jiffies_to_msecs(s->stats->run.rs_request_delay /
1194 s->stats->ts_requested));
1195 seq_printf(seq, " %ums running transaction\n",
1196 jiffies_to_msecs(s->stats->run.rs_running / s->stats->ts_tid));
1197 seq_printf(seq, " %ums transaction was being locked\n",
1198 jiffies_to_msecs(s->stats->run.rs_locked / s->stats->ts_tid));
1199 seq_printf(seq, " %ums flushing data (in ordered mode)\n",
1200 jiffies_to_msecs(s->stats->run.rs_flushing / s->stats->ts_tid));
1201 seq_printf(seq, " %ums logging transaction\n",
1202 jiffies_to_msecs(s->stats->run.rs_logging / s->stats->ts_tid));
1203 seq_printf(seq, " %lluus average transaction commit time\n",
1204 div_u64(s->journal->j_average_commit_time, 1000));
1205 seq_printf(seq, " %lu handles per transaction\n",
1206 s->stats->run.rs_handle_count / s->stats->ts_tid);
1207 seq_printf(seq, " %lu blocks per transaction\n",
1208 s->stats->run.rs_blocks / s->stats->ts_tid);
1209 seq_printf(seq, " %lu logged blocks per transaction\n",
1210 s->stats->run.rs_blocks_logged / s->stats->ts_tid);
1214 static void jbd2_seq_info_stop(struct seq_file *seq, void *v)
1218 static const struct seq_operations jbd2_seq_info_ops = {
1219 .start = jbd2_seq_info_start,
1220 .next = jbd2_seq_info_next,
1221 .stop = jbd2_seq_info_stop,
1222 .show = jbd2_seq_info_show,
1225 static int jbd2_seq_info_open(struct inode *inode, struct file *file)
1227 journal_t *journal = PDE_DATA(inode);
1228 struct jbd2_stats_proc_session *s;
1231 s = kmalloc(sizeof(*s), GFP_KERNEL);
1234 size = sizeof(struct transaction_stats_s);
1235 s->stats = kmalloc(size, GFP_KERNEL);
1236 if (s->stats == NULL) {
1240 spin_lock(&journal->j_history_lock);
1241 memcpy(s->stats, &journal->j_stats, size);
1242 s->journal = journal;
1243 spin_unlock(&journal->j_history_lock);
1245 rc = seq_open(file, &jbd2_seq_info_ops);
1247 struct seq_file *m = file->private_data;
1257 static int jbd2_seq_info_release(struct inode *inode, struct file *file)
1259 struct seq_file *seq = file->private_data;
1260 struct jbd2_stats_proc_session *s = seq->private;
1263 return seq_release(inode, file);
1266 static const struct proc_ops jbd2_info_proc_ops = {
1267 .proc_open = jbd2_seq_info_open,
1268 .proc_read = seq_read,
1269 .proc_lseek = seq_lseek,
1270 .proc_release = jbd2_seq_info_release,
1273 static struct proc_dir_entry *proc_jbd2_stats;
1275 static void jbd2_stats_proc_init(journal_t *journal)
1277 journal->j_proc_entry = proc_mkdir(journal->j_devname, proc_jbd2_stats);
1278 if (journal->j_proc_entry) {
1279 proc_create_data("info", S_IRUGO, journal->j_proc_entry,
1280 &jbd2_info_proc_ops, journal);
1284 static void jbd2_stats_proc_exit(journal_t *journal)
1286 remove_proc_entry("info", journal->j_proc_entry);
1287 remove_proc_entry(journal->j_devname, proc_jbd2_stats);
1290 /* Minimum size of descriptor tag */
1291 static int jbd2_min_tag_size(void)
1294 * Tag with 32-bit block numbers does not use last four bytes of the
1297 return sizeof(journal_block_tag_t) - 4;
1301 * Management for journal control blocks: functions to create and
1302 * destroy journal_t structures, and to initialise and read existing
1303 * journal blocks from disk. */
1305 /* First: create and setup a journal_t object in memory. We initialise
1306 * very few fields yet: that has to wait until we have created the
1307 * journal structures from from scratch, or loaded them from disk. */
1309 static journal_t *journal_init_common(struct block_device *bdev,
1310 struct block_device *fs_dev,
1311 unsigned long long start, int len, int blocksize)
1313 static struct lock_class_key jbd2_trans_commit_key;
1316 struct buffer_head *bh;
1319 journal = kzalloc(sizeof(*journal), GFP_KERNEL);
1323 init_waitqueue_head(&journal->j_wait_transaction_locked);
1324 init_waitqueue_head(&journal->j_wait_done_commit);
1325 init_waitqueue_head(&journal->j_wait_commit);
1326 init_waitqueue_head(&journal->j_wait_updates);
1327 init_waitqueue_head(&journal->j_wait_reserved);
1328 init_waitqueue_head(&journal->j_fc_wait);
1329 mutex_init(&journal->j_abort_mutex);
1330 mutex_init(&journal->j_barrier);
1331 mutex_init(&journal->j_checkpoint_mutex);
1332 spin_lock_init(&journal->j_revoke_lock);
1333 spin_lock_init(&journal->j_list_lock);
1334 rwlock_init(&journal->j_state_lock);
1336 journal->j_commit_interval = (HZ * JBD2_DEFAULT_MAX_COMMIT_AGE);
1337 journal->j_min_batch_time = 0;
1338 journal->j_max_batch_time = 15000; /* 15ms */
1339 atomic_set(&journal->j_reserved_credits, 0);
1341 /* The journal is marked for error until we succeed with recovery! */
1342 journal->j_flags = JBD2_ABORT;
1344 /* Set up a default-sized revoke table for the new mount. */
1345 err = jbd2_journal_init_revoke(journal, JOURNAL_REVOKE_DEFAULT_HASH);
1349 spin_lock_init(&journal->j_history_lock);
1351 lockdep_init_map(&journal->j_trans_commit_map, "jbd2_handle",
1352 &jbd2_trans_commit_key, 0);
1354 /* journal descriptor can store up to n blocks -bzzz */
1355 journal->j_blocksize = blocksize;
1356 journal->j_dev = bdev;
1357 journal->j_fs_dev = fs_dev;
1358 journal->j_blk_offset = start;
1359 journal->j_total_len = len;
1360 /* We need enough buffers to write out full descriptor block. */
1361 n = journal->j_blocksize / jbd2_min_tag_size();
1362 journal->j_wbufsize = n;
1363 journal->j_fc_wbuf = NULL;
1364 journal->j_wbuf = kmalloc_array(n, sizeof(struct buffer_head *),
1366 if (!journal->j_wbuf)
1369 bh = getblk_unmovable(journal->j_dev, start, journal->j_blocksize);
1371 pr_err("%s: Cannot get buffer for journal superblock\n",
1375 journal->j_sb_buffer = bh;
1376 journal->j_superblock = (journal_superblock_t *)bh->b_data;
1381 kfree(journal->j_wbuf);
1382 jbd2_journal_destroy_revoke(journal);
1387 /* jbd2_journal_init_dev and jbd2_journal_init_inode:
1389 * Create a journal structure assigned some fixed set of disk blocks to
1390 * the journal. We don't actually touch those disk blocks yet, but we
1391 * need to set up all of the mapping information to tell the journaling
1392 * system where the journal blocks are.
1397 * journal_t * jbd2_journal_init_dev() - creates and initialises a journal structure
1398 * @bdev: Block device on which to create the journal
1399 * @fs_dev: Device which hold journalled filesystem for this journal.
1400 * @start: Block nr Start of journal.
1401 * @len: Length of the journal in blocks.
1402 * @blocksize: blocksize of journalling device
1404 * Returns: a newly created journal_t *
1406 * jbd2_journal_init_dev creates a journal which maps a fixed contiguous
1407 * range of blocks on an arbitrary block device.
1410 journal_t *jbd2_journal_init_dev(struct block_device *bdev,
1411 struct block_device *fs_dev,
1412 unsigned long long start, int len, int blocksize)
1416 journal = journal_init_common(bdev, fs_dev, start, len, blocksize);
1420 bdevname(journal->j_dev, journal->j_devname);
1421 strreplace(journal->j_devname, '/', '!');
1422 jbd2_stats_proc_init(journal);
1428 * journal_t * jbd2_journal_init_inode () - creates a journal which maps to a inode.
1429 * @inode: An inode to create the journal in
1431 * jbd2_journal_init_inode creates a journal which maps an on-disk inode as
1432 * the journal. The inode must exist already, must support bmap() and
1433 * must have all data blocks preallocated.
1435 journal_t *jbd2_journal_init_inode(struct inode *inode)
1443 err = bmap(inode, &blocknr);
1445 if (err || !blocknr) {
1446 pr_err("%s: Cannot locate journal superblock\n",
1451 jbd_debug(1, "JBD2: inode %s/%ld, size %lld, bits %d, blksize %ld\n",
1452 inode->i_sb->s_id, inode->i_ino, (long long) inode->i_size,
1453 inode->i_sb->s_blocksize_bits, inode->i_sb->s_blocksize);
1455 journal = journal_init_common(inode->i_sb->s_bdev, inode->i_sb->s_bdev,
1456 blocknr, inode->i_size >> inode->i_sb->s_blocksize_bits,
1457 inode->i_sb->s_blocksize);
1461 journal->j_inode = inode;
1462 bdevname(journal->j_dev, journal->j_devname);
1463 p = strreplace(journal->j_devname, '/', '!');
1464 sprintf(p, "-%lu", journal->j_inode->i_ino);
1465 jbd2_stats_proc_init(journal);
1471 * If the journal init or create aborts, we need to mark the journal
1472 * superblock as being NULL to prevent the journal destroy from writing
1473 * back a bogus superblock.
1475 static void journal_fail_superblock(journal_t *journal)
1477 struct buffer_head *bh = journal->j_sb_buffer;
1479 journal->j_sb_buffer = NULL;
1483 * Given a journal_t structure, initialise the various fields for
1484 * startup of a new journaling session. We use this both when creating
1485 * a journal, and after recovering an old journal to reset it for
1489 static int journal_reset(journal_t *journal)
1491 journal_superblock_t *sb = journal->j_superblock;
1492 unsigned long long first, last;
1494 first = be32_to_cpu(sb->s_first);
1495 last = be32_to_cpu(sb->s_maxlen);
1496 if (first + JBD2_MIN_JOURNAL_BLOCKS > last + 1) {
1497 printk(KERN_ERR "JBD2: Journal too short (blocks %llu-%llu).\n",
1499 journal_fail_superblock(journal);
1503 journal->j_first = first;
1504 journal->j_last = last;
1506 journal->j_head = journal->j_first;
1507 journal->j_tail = journal->j_first;
1508 journal->j_free = journal->j_last - journal->j_first;
1510 journal->j_tail_sequence = journal->j_transaction_sequence;
1511 journal->j_commit_sequence = journal->j_transaction_sequence - 1;
1512 journal->j_commit_request = journal->j_commit_sequence;
1514 journal->j_max_transaction_buffers = jbd2_journal_get_max_txn_bufs(journal);
1517 * Now that journal recovery is done, turn fast commits off here. This
1518 * way, if fast commit was enabled before the crash but if now FS has
1519 * disabled it, we don't enable fast commits.
1521 jbd2_clear_feature_fast_commit(journal);
1524 * As a special case, if the on-disk copy is already marked as needing
1525 * no recovery (s_start == 0), then we can safely defer the superblock
1526 * update until the next commit by setting JBD2_FLUSHED. This avoids
1527 * attempting a write to a potential-readonly device.
1529 if (sb->s_start == 0) {
1530 jbd_debug(1, "JBD2: Skipping superblock update on recovered sb "
1531 "(start %ld, seq %u, errno %d)\n",
1532 journal->j_tail, journal->j_tail_sequence,
1534 journal->j_flags |= JBD2_FLUSHED;
1536 /* Lock here to make assertions happy... */
1537 mutex_lock_io(&journal->j_checkpoint_mutex);
1539 * Update log tail information. We use REQ_FUA since new
1540 * transaction will start reusing journal space and so we
1541 * must make sure information about current log tail is on
1544 jbd2_journal_update_sb_log_tail(journal,
1545 journal->j_tail_sequence,
1547 REQ_SYNC | REQ_FUA);
1548 mutex_unlock(&journal->j_checkpoint_mutex);
1550 return jbd2_journal_start_thread(journal);
1554 * This function expects that the caller will have locked the journal
1555 * buffer head, and will return with it unlocked
1557 static int jbd2_write_superblock(journal_t *journal, int write_flags)
1559 struct buffer_head *bh = journal->j_sb_buffer;
1560 journal_superblock_t *sb = journal->j_superblock;
1563 /* Buffer got discarded which means block device got invalidated */
1564 if (!buffer_mapped(bh)) {
1569 trace_jbd2_write_superblock(journal, write_flags);
1570 if (!(journal->j_flags & JBD2_BARRIER))
1571 write_flags &= ~(REQ_FUA | REQ_PREFLUSH);
1572 if (buffer_write_io_error(bh)) {
1574 * Oh, dear. A previous attempt to write the journal
1575 * superblock failed. This could happen because the
1576 * USB device was yanked out. Or it could happen to
1577 * be a transient write error and maybe the block will
1578 * be remapped. Nothing we can do but to retry the
1579 * write and hope for the best.
1581 printk(KERN_ERR "JBD2: previous I/O error detected "
1582 "for journal superblock update for %s.\n",
1583 journal->j_devname);
1584 clear_buffer_write_io_error(bh);
1585 set_buffer_uptodate(bh);
1587 if (jbd2_journal_has_csum_v2or3(journal))
1588 sb->s_checksum = jbd2_superblock_csum(journal, sb);
1590 bh->b_end_io = end_buffer_write_sync;
1591 ret = submit_bh(REQ_OP_WRITE, write_flags, bh);
1593 if (buffer_write_io_error(bh)) {
1594 clear_buffer_write_io_error(bh);
1595 set_buffer_uptodate(bh);
1599 printk(KERN_ERR "JBD2: Error %d detected when updating "
1600 "journal superblock for %s.\n", ret,
1601 journal->j_devname);
1602 if (!is_journal_aborted(journal))
1603 jbd2_journal_abort(journal, ret);
1610 * jbd2_journal_update_sb_log_tail() - Update log tail in journal sb on disk.
1611 * @journal: The journal to update.
1612 * @tail_tid: TID of the new transaction at the tail of the log
1613 * @tail_block: The first block of the transaction at the tail of the log
1614 * @write_op: With which operation should we write the journal sb
1616 * Update a journal's superblock information about log tail and write it to
1617 * disk, waiting for the IO to complete.
1619 int jbd2_journal_update_sb_log_tail(journal_t *journal, tid_t tail_tid,
1620 unsigned long tail_block, int write_op)
1622 journal_superblock_t *sb = journal->j_superblock;
1625 if (is_journal_aborted(journal))
1628 BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
1629 jbd_debug(1, "JBD2: updating superblock (start %lu, seq %u)\n",
1630 tail_block, tail_tid);
1632 lock_buffer(journal->j_sb_buffer);
1633 sb->s_sequence = cpu_to_be32(tail_tid);
1634 sb->s_start = cpu_to_be32(tail_block);
1636 ret = jbd2_write_superblock(journal, write_op);
1640 /* Log is no longer empty */
1641 write_lock(&journal->j_state_lock);
1642 WARN_ON(!sb->s_sequence);
1643 journal->j_flags &= ~JBD2_FLUSHED;
1644 write_unlock(&journal->j_state_lock);
1651 * jbd2_mark_journal_empty() - Mark on disk journal as empty.
1652 * @journal: The journal to update.
1653 * @write_op: With which operation should we write the journal sb
1655 * Update a journal's dynamic superblock fields to show that journal is empty.
1656 * Write updated superblock to disk waiting for IO to complete.
1658 static void jbd2_mark_journal_empty(journal_t *journal, int write_op)
1660 journal_superblock_t *sb = journal->j_superblock;
1661 bool had_fast_commit = false;
1663 BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
1664 lock_buffer(journal->j_sb_buffer);
1665 if (sb->s_start == 0) { /* Is it already empty? */
1666 unlock_buffer(journal->j_sb_buffer);
1670 jbd_debug(1, "JBD2: Marking journal as empty (seq %u)\n",
1671 journal->j_tail_sequence);
1673 sb->s_sequence = cpu_to_be32(journal->j_tail_sequence);
1674 sb->s_start = cpu_to_be32(0);
1675 if (jbd2_has_feature_fast_commit(journal)) {
1677 * When journal is clean, no need to commit fast commit flag and
1678 * make file system incompatible with older kernels.
1680 jbd2_clear_feature_fast_commit(journal);
1681 had_fast_commit = true;
1684 jbd2_write_superblock(journal, write_op);
1686 if (had_fast_commit)
1687 jbd2_set_feature_fast_commit(journal);
1689 /* Log is no longer empty */
1690 write_lock(&journal->j_state_lock);
1691 journal->j_flags |= JBD2_FLUSHED;
1692 write_unlock(&journal->j_state_lock);
1697 * jbd2_journal_update_sb_errno() - Update error in the journal.
1698 * @journal: The journal to update.
1700 * Update a journal's errno. Write updated superblock to disk waiting for IO
1703 void jbd2_journal_update_sb_errno(journal_t *journal)
1705 journal_superblock_t *sb = journal->j_superblock;
1708 lock_buffer(journal->j_sb_buffer);
1709 errcode = journal->j_errno;
1710 if (errcode == -ESHUTDOWN)
1712 jbd_debug(1, "JBD2: updating superblock error (errno %d)\n", errcode);
1713 sb->s_errno = cpu_to_be32(errcode);
1715 jbd2_write_superblock(journal, REQ_SYNC | REQ_FUA);
1717 EXPORT_SYMBOL(jbd2_journal_update_sb_errno);
1719 static int journal_revoke_records_per_block(journal_t *journal)
1722 int space = journal->j_blocksize - sizeof(jbd2_journal_revoke_header_t);
1724 if (jbd2_has_feature_64bit(journal))
1729 if (jbd2_journal_has_csum_v2or3(journal))
1730 space -= sizeof(struct jbd2_journal_block_tail);
1731 return space / record_size;
1735 * Read the superblock for a given journal, performing initial
1736 * validation of the format.
1738 static int journal_get_superblock(journal_t *journal)
1740 struct buffer_head *bh;
1741 journal_superblock_t *sb;
1744 bh = journal->j_sb_buffer;
1746 J_ASSERT(bh != NULL);
1747 if (!buffer_uptodate(bh)) {
1748 ll_rw_block(REQ_OP_READ, 0, 1, &bh);
1750 if (!buffer_uptodate(bh)) {
1752 "JBD2: IO error reading journal superblock\n");
1757 if (buffer_verified(bh))
1760 sb = journal->j_superblock;
1764 if (sb->s_header.h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER) ||
1765 sb->s_blocksize != cpu_to_be32(journal->j_blocksize)) {
1766 printk(KERN_WARNING "JBD2: no valid journal superblock found\n");
1770 switch(be32_to_cpu(sb->s_header.h_blocktype)) {
1771 case JBD2_SUPERBLOCK_V1:
1772 journal->j_format_version = 1;
1774 case JBD2_SUPERBLOCK_V2:
1775 journal->j_format_version = 2;
1778 printk(KERN_WARNING "JBD2: unrecognised superblock format ID\n");
1782 if (be32_to_cpu(sb->s_maxlen) < journal->j_total_len)
1783 journal->j_total_len = be32_to_cpu(sb->s_maxlen);
1784 else if (be32_to_cpu(sb->s_maxlen) > journal->j_total_len) {
1785 printk(KERN_WARNING "JBD2: journal file too short\n");
1789 if (be32_to_cpu(sb->s_first) == 0 ||
1790 be32_to_cpu(sb->s_first) >= journal->j_total_len) {
1792 "JBD2: Invalid start block of journal: %u\n",
1793 be32_to_cpu(sb->s_first));
1797 if (jbd2_has_feature_csum2(journal) &&
1798 jbd2_has_feature_csum3(journal)) {
1799 /* Can't have checksum v2 and v3 at the same time! */
1800 printk(KERN_ERR "JBD2: Can't enable checksumming v2 and v3 "
1801 "at the same time!\n");
1805 if (jbd2_journal_has_csum_v2or3_feature(journal) &&
1806 jbd2_has_feature_checksum(journal)) {
1807 /* Can't have checksum v1 and v2 on at the same time! */
1808 printk(KERN_ERR "JBD2: Can't enable checksumming v1 and v2/3 "
1809 "at the same time!\n");
1813 if (!jbd2_verify_csum_type(journal, sb)) {
1814 printk(KERN_ERR "JBD2: Unknown checksum type\n");
1818 /* Load the checksum driver */
1819 if (jbd2_journal_has_csum_v2or3_feature(journal)) {
1820 journal->j_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
1821 if (IS_ERR(journal->j_chksum_driver)) {
1822 printk(KERN_ERR "JBD2: Cannot load crc32c driver.\n");
1823 err = PTR_ERR(journal->j_chksum_driver);
1824 journal->j_chksum_driver = NULL;
1829 if (jbd2_journal_has_csum_v2or3(journal)) {
1830 /* Check superblock checksum */
1831 if (sb->s_checksum != jbd2_superblock_csum(journal, sb)) {
1832 printk(KERN_ERR "JBD2: journal checksum error\n");
1837 /* Precompute checksum seed for all metadata */
1838 journal->j_csum_seed = jbd2_chksum(journal, ~0, sb->s_uuid,
1839 sizeof(sb->s_uuid));
1842 journal->j_revoke_records_per_block =
1843 journal_revoke_records_per_block(journal);
1844 set_buffer_verified(bh);
1849 journal_fail_superblock(journal);
1854 * Load the on-disk journal superblock and read the key fields into the
1858 static int load_superblock(journal_t *journal)
1861 journal_superblock_t *sb;
1864 err = journal_get_superblock(journal);
1868 sb = journal->j_superblock;
1870 journal->j_tail_sequence = be32_to_cpu(sb->s_sequence);
1871 journal->j_tail = be32_to_cpu(sb->s_start);
1872 journal->j_first = be32_to_cpu(sb->s_first);
1873 journal->j_errno = be32_to_cpu(sb->s_errno);
1874 journal->j_last = be32_to_cpu(sb->s_maxlen);
1876 if (jbd2_has_feature_fast_commit(journal)) {
1877 journal->j_fc_last = be32_to_cpu(sb->s_maxlen);
1878 num_fc_blocks = be32_to_cpu(sb->s_num_fc_blks);
1880 num_fc_blocks = JBD2_MIN_FC_BLOCKS;
1881 if (journal->j_last - num_fc_blocks >= JBD2_MIN_JOURNAL_BLOCKS)
1882 journal->j_last = journal->j_fc_last - num_fc_blocks;
1883 journal->j_fc_first = journal->j_last + 1;
1884 journal->j_fc_off = 0;
1892 * jbd2_journal_load() - Read journal from disk.
1893 * @journal: Journal to act on.
1895 * Given a journal_t structure which tells us which disk blocks contain
1896 * a journal, read the journal from disk to initialise the in-memory
1899 int jbd2_journal_load(journal_t *journal)
1902 journal_superblock_t *sb;
1904 err = load_superblock(journal);
1908 sb = journal->j_superblock;
1909 /* If this is a V2 superblock, then we have to check the
1910 * features flags on it. */
1912 if (journal->j_format_version >= 2) {
1913 if ((sb->s_feature_ro_compat &
1914 ~cpu_to_be32(JBD2_KNOWN_ROCOMPAT_FEATURES)) ||
1915 (sb->s_feature_incompat &
1916 ~cpu_to_be32(JBD2_KNOWN_INCOMPAT_FEATURES))) {
1918 "JBD2: Unrecognised features on journal\n");
1924 * Create a slab for this blocksize
1926 err = jbd2_journal_create_slab(be32_to_cpu(sb->s_blocksize));
1930 /* Let the recovery code check whether it needs to recover any
1931 * data from the journal. */
1932 if (jbd2_journal_recover(journal))
1933 goto recovery_error;
1935 if (journal->j_failed_commit) {
1936 printk(KERN_ERR "JBD2: journal transaction %u on %s "
1937 "is corrupt.\n", journal->j_failed_commit,
1938 journal->j_devname);
1939 return -EFSCORRUPTED;
1942 * clear JBD2_ABORT flag initialized in journal_init_common
1943 * here to update log tail information with the newest seq.
1945 journal->j_flags &= ~JBD2_ABORT;
1947 /* OK, we've finished with the dynamic journal bits:
1948 * reinitialise the dynamic contents of the superblock in memory
1949 * and reset them on disk. */
1950 if (journal_reset(journal))
1951 goto recovery_error;
1953 journal->j_flags |= JBD2_LOADED;
1957 printk(KERN_WARNING "JBD2: recovery failed\n");
1962 * jbd2_journal_destroy() - Release a journal_t structure.
1963 * @journal: Journal to act on.
1965 * Release a journal_t structure once it is no longer in use by the
1967 * Return <0 if we couldn't clean up the journal.
1969 int jbd2_journal_destroy(journal_t *journal)
1973 /* Wait for the commit thread to wake up and die. */
1974 journal_kill_thread(journal);
1976 /* Force a final log commit */
1977 if (journal->j_running_transaction)
1978 jbd2_journal_commit_transaction(journal);
1980 /* Force any old transactions to disk */
1982 /* Totally anal locking here... */
1983 spin_lock(&journal->j_list_lock);
1984 while (journal->j_checkpoint_transactions != NULL) {
1985 spin_unlock(&journal->j_list_lock);
1986 mutex_lock_io(&journal->j_checkpoint_mutex);
1987 err = jbd2_log_do_checkpoint(journal);
1988 mutex_unlock(&journal->j_checkpoint_mutex);
1990 * If checkpointing failed, just free the buffers to avoid
1994 jbd2_journal_destroy_checkpoint(journal);
1995 spin_lock(&journal->j_list_lock);
1998 spin_lock(&journal->j_list_lock);
2001 J_ASSERT(journal->j_running_transaction == NULL);
2002 J_ASSERT(journal->j_committing_transaction == NULL);
2003 J_ASSERT(journal->j_checkpoint_transactions == NULL);
2004 spin_unlock(&journal->j_list_lock);
2006 if (journal->j_sb_buffer) {
2007 if (!is_journal_aborted(journal)) {
2008 mutex_lock_io(&journal->j_checkpoint_mutex);
2010 write_lock(&journal->j_state_lock);
2011 journal->j_tail_sequence =
2012 ++journal->j_transaction_sequence;
2013 write_unlock(&journal->j_state_lock);
2015 jbd2_mark_journal_empty(journal,
2016 REQ_SYNC | REQ_PREFLUSH | REQ_FUA);
2017 mutex_unlock(&journal->j_checkpoint_mutex);
2020 brelse(journal->j_sb_buffer);
2023 if (journal->j_proc_entry)
2024 jbd2_stats_proc_exit(journal);
2025 iput(journal->j_inode);
2026 if (journal->j_revoke)
2027 jbd2_journal_destroy_revoke(journal);
2028 if (journal->j_chksum_driver)
2029 crypto_free_shash(journal->j_chksum_driver);
2030 kfree(journal->j_fc_wbuf);
2031 kfree(journal->j_wbuf);
2039 * jbd2_journal_check_used_features() - Check if features specified are used.
2040 * @journal: Journal to check.
2041 * @compat: bitmask of compatible features
2042 * @ro: bitmask of features that force read-only mount
2043 * @incompat: bitmask of incompatible features
2045 * Check whether the journal uses all of a given set of
2046 * features. Return true (non-zero) if it does.
2049 int jbd2_journal_check_used_features(journal_t *journal, unsigned long compat,
2050 unsigned long ro, unsigned long incompat)
2052 journal_superblock_t *sb;
2054 if (!compat && !ro && !incompat)
2056 /* Load journal superblock if it is not loaded yet. */
2057 if (journal->j_format_version == 0 &&
2058 journal_get_superblock(journal) != 0)
2060 if (journal->j_format_version == 1)
2063 sb = journal->j_superblock;
2065 if (((be32_to_cpu(sb->s_feature_compat) & compat) == compat) &&
2066 ((be32_to_cpu(sb->s_feature_ro_compat) & ro) == ro) &&
2067 ((be32_to_cpu(sb->s_feature_incompat) & incompat) == incompat))
2074 * jbd2_journal_check_available_features() - Check feature set in journalling layer
2075 * @journal: Journal to check.
2076 * @compat: bitmask of compatible features
2077 * @ro: bitmask of features that force read-only mount
2078 * @incompat: bitmask of incompatible features
2080 * Check whether the journaling code supports the use of
2081 * all of a given set of features on this journal. Return true
2082 * (non-zero) if it can. */
2084 int jbd2_journal_check_available_features(journal_t *journal, unsigned long compat,
2085 unsigned long ro, unsigned long incompat)
2087 if (!compat && !ro && !incompat)
2090 /* We can support any known requested features iff the
2091 * superblock is in version 2. Otherwise we fail to support any
2092 * extended sb features. */
2094 if (journal->j_format_version != 2)
2097 if ((compat & JBD2_KNOWN_COMPAT_FEATURES) == compat &&
2098 (ro & JBD2_KNOWN_ROCOMPAT_FEATURES) == ro &&
2099 (incompat & JBD2_KNOWN_INCOMPAT_FEATURES) == incompat)
2106 jbd2_journal_initialize_fast_commit(journal_t *journal)
2108 journal_superblock_t *sb = journal->j_superblock;
2109 unsigned long long num_fc_blks;
2111 num_fc_blks = be32_to_cpu(sb->s_num_fc_blks);
2112 if (num_fc_blks == 0)
2113 num_fc_blks = JBD2_MIN_FC_BLOCKS;
2114 if (journal->j_last - num_fc_blks < JBD2_MIN_JOURNAL_BLOCKS)
2117 /* Are we called twice? */
2118 WARN_ON(journal->j_fc_wbuf != NULL);
2119 journal->j_fc_wbuf = kmalloc_array(num_fc_blks,
2120 sizeof(struct buffer_head *), GFP_KERNEL);
2121 if (!journal->j_fc_wbuf)
2124 journal->j_fc_wbufsize = num_fc_blks;
2125 journal->j_fc_last = journal->j_last;
2126 journal->j_last = journal->j_fc_last - num_fc_blks;
2127 journal->j_fc_first = journal->j_last + 1;
2128 journal->j_fc_off = 0;
2129 journal->j_free = journal->j_last - journal->j_first;
2130 journal->j_max_transaction_buffers =
2131 jbd2_journal_get_max_txn_bufs(journal);
2137 * jbd2_journal_set_features() - Mark a given journal feature in the superblock
2138 * @journal: Journal to act on.
2139 * @compat: bitmask of compatible features
2140 * @ro: bitmask of features that force read-only mount
2141 * @incompat: bitmask of incompatible features
2143 * Mark a given journal feature as present on the
2144 * superblock. Returns true if the requested features could be set.
2148 int jbd2_journal_set_features(journal_t *journal, unsigned long compat,
2149 unsigned long ro, unsigned long incompat)
2151 #define INCOMPAT_FEATURE_ON(f) \
2152 ((incompat & (f)) && !(sb->s_feature_incompat & cpu_to_be32(f)))
2153 #define COMPAT_FEATURE_ON(f) \
2154 ((compat & (f)) && !(sb->s_feature_compat & cpu_to_be32(f)))
2155 journal_superblock_t *sb;
2157 if (jbd2_journal_check_used_features(journal, compat, ro, incompat))
2160 if (!jbd2_journal_check_available_features(journal, compat, ro, incompat))
2163 /* If enabling v2 checksums, turn on v3 instead */
2164 if (incompat & JBD2_FEATURE_INCOMPAT_CSUM_V2) {
2165 incompat &= ~JBD2_FEATURE_INCOMPAT_CSUM_V2;
2166 incompat |= JBD2_FEATURE_INCOMPAT_CSUM_V3;
2169 /* Asking for checksumming v3 and v1? Only give them v3. */
2170 if (incompat & JBD2_FEATURE_INCOMPAT_CSUM_V3 &&
2171 compat & JBD2_FEATURE_COMPAT_CHECKSUM)
2172 compat &= ~JBD2_FEATURE_COMPAT_CHECKSUM;
2174 jbd_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n",
2175 compat, ro, incompat);
2177 sb = journal->j_superblock;
2179 if (incompat & JBD2_FEATURE_INCOMPAT_FAST_COMMIT) {
2180 if (jbd2_journal_initialize_fast_commit(journal)) {
2181 pr_err("JBD2: Cannot enable fast commits.\n");
2186 /* Load the checksum driver if necessary */
2187 if ((journal->j_chksum_driver == NULL) &&
2188 INCOMPAT_FEATURE_ON(JBD2_FEATURE_INCOMPAT_CSUM_V3)) {
2189 journal->j_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
2190 if (IS_ERR(journal->j_chksum_driver)) {
2191 printk(KERN_ERR "JBD2: Cannot load crc32c driver.\n");
2192 journal->j_chksum_driver = NULL;
2195 /* Precompute checksum seed for all metadata */
2196 journal->j_csum_seed = jbd2_chksum(journal, ~0, sb->s_uuid,
2197 sizeof(sb->s_uuid));
2200 lock_buffer(journal->j_sb_buffer);
2202 /* If enabling v3 checksums, update superblock */
2203 if (INCOMPAT_FEATURE_ON(JBD2_FEATURE_INCOMPAT_CSUM_V3)) {
2204 sb->s_checksum_type = JBD2_CRC32C_CHKSUM;
2205 sb->s_feature_compat &=
2206 ~cpu_to_be32(JBD2_FEATURE_COMPAT_CHECKSUM);
2209 /* If enabling v1 checksums, downgrade superblock */
2210 if (COMPAT_FEATURE_ON(JBD2_FEATURE_COMPAT_CHECKSUM))
2211 sb->s_feature_incompat &=
2212 ~cpu_to_be32(JBD2_FEATURE_INCOMPAT_CSUM_V2 |
2213 JBD2_FEATURE_INCOMPAT_CSUM_V3);
2215 sb->s_feature_compat |= cpu_to_be32(compat);
2216 sb->s_feature_ro_compat |= cpu_to_be32(ro);
2217 sb->s_feature_incompat |= cpu_to_be32(incompat);
2218 unlock_buffer(journal->j_sb_buffer);
2219 journal->j_revoke_records_per_block =
2220 journal_revoke_records_per_block(journal);
2223 #undef COMPAT_FEATURE_ON
2224 #undef INCOMPAT_FEATURE_ON
2228 * jbd2_journal_clear_features() - Clear a given journal feature in the
2230 * @journal: Journal to act on.
2231 * @compat: bitmask of compatible features
2232 * @ro: bitmask of features that force read-only mount
2233 * @incompat: bitmask of incompatible features
2235 * Clear a given journal feature as present on the
2238 void jbd2_journal_clear_features(journal_t *journal, unsigned long compat,
2239 unsigned long ro, unsigned long incompat)
2241 journal_superblock_t *sb;
2243 jbd_debug(1, "Clear features 0x%lx/0x%lx/0x%lx\n",
2244 compat, ro, incompat);
2246 sb = journal->j_superblock;
2248 sb->s_feature_compat &= ~cpu_to_be32(compat);
2249 sb->s_feature_ro_compat &= ~cpu_to_be32(ro);
2250 sb->s_feature_incompat &= ~cpu_to_be32(incompat);
2251 journal->j_revoke_records_per_block =
2252 journal_revoke_records_per_block(journal);
2254 EXPORT_SYMBOL(jbd2_journal_clear_features);
2257 * jbd2_journal_flush() - Flush journal
2258 * @journal: Journal to act on.
2260 * Flush all data for a given journal to disk and empty the journal.
2261 * Filesystems can use this when remounting readonly to ensure that
2262 * recovery does not need to happen on remount.
2265 int jbd2_journal_flush(journal_t *journal)
2268 transaction_t *transaction = NULL;
2270 write_lock(&journal->j_state_lock);
2272 /* Force everything buffered to the log... */
2273 if (journal->j_running_transaction) {
2274 transaction = journal->j_running_transaction;
2275 __jbd2_log_start_commit(journal, transaction->t_tid);
2276 } else if (journal->j_committing_transaction)
2277 transaction = journal->j_committing_transaction;
2279 /* Wait for the log commit to complete... */
2281 tid_t tid = transaction->t_tid;
2283 write_unlock(&journal->j_state_lock);
2284 jbd2_log_wait_commit(journal, tid);
2286 write_unlock(&journal->j_state_lock);
2289 /* ...and flush everything in the log out to disk. */
2290 spin_lock(&journal->j_list_lock);
2291 while (!err && journal->j_checkpoint_transactions != NULL) {
2292 spin_unlock(&journal->j_list_lock);
2293 mutex_lock_io(&journal->j_checkpoint_mutex);
2294 err = jbd2_log_do_checkpoint(journal);
2295 mutex_unlock(&journal->j_checkpoint_mutex);
2296 spin_lock(&journal->j_list_lock);
2298 spin_unlock(&journal->j_list_lock);
2300 if (is_journal_aborted(journal))
2303 mutex_lock_io(&journal->j_checkpoint_mutex);
2305 err = jbd2_cleanup_journal_tail(journal);
2307 mutex_unlock(&journal->j_checkpoint_mutex);
2313 /* Finally, mark the journal as really needing no recovery.
2314 * This sets s_start==0 in the underlying superblock, which is
2315 * the magic code for a fully-recovered superblock. Any future
2316 * commits of data to the journal will restore the current
2318 jbd2_mark_journal_empty(journal, REQ_SYNC | REQ_FUA);
2319 mutex_unlock(&journal->j_checkpoint_mutex);
2320 write_lock(&journal->j_state_lock);
2321 J_ASSERT(!journal->j_running_transaction);
2322 J_ASSERT(!journal->j_committing_transaction);
2323 J_ASSERT(!journal->j_checkpoint_transactions);
2324 J_ASSERT(journal->j_head == journal->j_tail);
2325 J_ASSERT(journal->j_tail_sequence == journal->j_transaction_sequence);
2326 write_unlock(&journal->j_state_lock);
2332 * jbd2_journal_wipe() - Wipe journal contents
2333 * @journal: Journal to act on.
2334 * @write: flag (see below)
2336 * Wipe out all of the contents of a journal, safely. This will produce
2337 * a warning if the journal contains any valid recovery information.
2338 * Must be called between journal_init_*() and jbd2_journal_load().
2340 * If 'write' is non-zero, then we wipe out the journal on disk; otherwise
2341 * we merely suppress recovery.
2344 int jbd2_journal_wipe(journal_t *journal, int write)
2348 J_ASSERT (!(journal->j_flags & JBD2_LOADED));
2350 err = load_superblock(journal);
2354 if (!journal->j_tail)
2357 printk(KERN_WARNING "JBD2: %s recovery information on journal\n",
2358 write ? "Clearing" : "Ignoring");
2360 err = jbd2_journal_skip_recovery(journal);
2362 /* Lock to make assertions happy... */
2363 mutex_lock_io(&journal->j_checkpoint_mutex);
2364 jbd2_mark_journal_empty(journal, REQ_SYNC | REQ_FUA);
2365 mutex_unlock(&journal->j_checkpoint_mutex);
2373 * jbd2_journal_abort () - Shutdown the journal immediately.
2374 * @journal: the journal to shutdown.
2375 * @errno: an error number to record in the journal indicating
2376 * the reason for the shutdown.
2378 * Perform a complete, immediate shutdown of the ENTIRE
2379 * journal (not of a single transaction). This operation cannot be
2380 * undone without closing and reopening the journal.
2382 * The jbd2_journal_abort function is intended to support higher level error
2383 * recovery mechanisms such as the ext2/ext3 remount-readonly error
2386 * Journal abort has very specific semantics. Any existing dirty,
2387 * unjournaled buffers in the main filesystem will still be written to
2388 * disk by bdflush, but the journaling mechanism will be suspended
2389 * immediately and no further transaction commits will be honoured.
2391 * Any dirty, journaled buffers will be written back to disk without
2392 * hitting the journal. Atomicity cannot be guaranteed on an aborted
2393 * filesystem, but we _do_ attempt to leave as much data as possible
2394 * behind for fsck to use for cleanup.
2396 * Any attempt to get a new transaction handle on a journal which is in
2397 * ABORT state will just result in an -EROFS error return. A
2398 * jbd2_journal_stop on an existing handle will return -EIO if we have
2399 * entered abort state during the update.
2401 * Recursive transactions are not disturbed by journal abort until the
2402 * final jbd2_journal_stop, which will receive the -EIO error.
2404 * Finally, the jbd2_journal_abort call allows the caller to supply an errno
2405 * which will be recorded (if possible) in the journal superblock. This
2406 * allows a client to record failure conditions in the middle of a
2407 * transaction without having to complete the transaction to record the
2408 * failure to disk. ext3_error, for example, now uses this
2413 void jbd2_journal_abort(journal_t *journal, int errno)
2415 transaction_t *transaction;
2418 * Lock the aborting procedure until everything is done, this avoid
2419 * races between filesystem's error handling flow (e.g. ext4_abort()),
2420 * ensure panic after the error info is written into journal's
2423 mutex_lock(&journal->j_abort_mutex);
2425 * ESHUTDOWN always takes precedence because a file system check
2426 * caused by any other journal abort error is not required after
2427 * a shutdown triggered.
2429 write_lock(&journal->j_state_lock);
2430 if (journal->j_flags & JBD2_ABORT) {
2431 int old_errno = journal->j_errno;
2433 write_unlock(&journal->j_state_lock);
2434 if (old_errno != -ESHUTDOWN && errno == -ESHUTDOWN) {
2435 journal->j_errno = errno;
2436 jbd2_journal_update_sb_errno(journal);
2438 mutex_unlock(&journal->j_abort_mutex);
2443 * Mark the abort as occurred and start current running transaction
2444 * to release all journaled buffer.
2446 pr_err("Aborting journal on device %s.\n", journal->j_devname);
2448 journal->j_flags |= JBD2_ABORT;
2449 journal->j_errno = errno;
2450 transaction = journal->j_running_transaction;
2452 __jbd2_log_start_commit(journal, transaction->t_tid);
2453 write_unlock(&journal->j_state_lock);
2456 * Record errno to the journal super block, so that fsck and jbd2
2457 * layer could realise that a filesystem check is needed.
2459 jbd2_journal_update_sb_errno(journal);
2460 mutex_unlock(&journal->j_abort_mutex);
2464 * jbd2_journal_errno() - returns the journal's error state.
2465 * @journal: journal to examine.
2467 * This is the errno number set with jbd2_journal_abort(), the last
2468 * time the journal was mounted - if the journal was stopped
2469 * without calling abort this will be 0.
2471 * If the journal has been aborted on this mount time -EROFS will
2474 int jbd2_journal_errno(journal_t *journal)
2478 read_lock(&journal->j_state_lock);
2479 if (journal->j_flags & JBD2_ABORT)
2482 err = journal->j_errno;
2483 read_unlock(&journal->j_state_lock);
2488 * jbd2_journal_clear_err() - clears the journal's error state
2489 * @journal: journal to act on.
2491 * An error must be cleared or acked to take a FS out of readonly
2494 int jbd2_journal_clear_err(journal_t *journal)
2498 write_lock(&journal->j_state_lock);
2499 if (journal->j_flags & JBD2_ABORT)
2502 journal->j_errno = 0;
2503 write_unlock(&journal->j_state_lock);
2508 * jbd2_journal_ack_err() - Ack journal err.
2509 * @journal: journal to act on.
2511 * An error must be cleared or acked to take a FS out of readonly
2514 void jbd2_journal_ack_err(journal_t *journal)
2516 write_lock(&journal->j_state_lock);
2517 if (journal->j_errno)
2518 journal->j_flags |= JBD2_ACK_ERR;
2519 write_unlock(&journal->j_state_lock);
2522 int jbd2_journal_blocks_per_page(struct inode *inode)
2524 return 1 << (PAGE_SHIFT - inode->i_sb->s_blocksize_bits);
2528 * helper functions to deal with 32 or 64bit block numbers.
2530 size_t journal_tag_bytes(journal_t *journal)
2534 if (jbd2_has_feature_csum3(journal))
2535 return sizeof(journal_block_tag3_t);
2537 sz = sizeof(journal_block_tag_t);
2539 if (jbd2_has_feature_csum2(journal))
2540 sz += sizeof(__u16);
2542 if (jbd2_has_feature_64bit(journal))
2545 return sz - sizeof(__u32);
2549 * JBD memory management
2551 * These functions are used to allocate block-sized chunks of memory
2552 * used for making copies of buffer_head data. Very often it will be
2553 * page-sized chunks of data, but sometimes it will be in
2554 * sub-page-size chunks. (For example, 16k pages on Power systems
2555 * with a 4k block file system.) For blocks smaller than a page, we
2556 * use a SLAB allocator. There are slab caches for each block size,
2557 * which are allocated at mount time, if necessary, and we only free
2558 * (all of) the slab caches when/if the jbd2 module is unloaded. For
2559 * this reason we don't need to a mutex to protect access to
2560 * jbd2_slab[] allocating or releasing memory; only in
2561 * jbd2_journal_create_slab().
2563 #define JBD2_MAX_SLABS 8
2564 static struct kmem_cache *jbd2_slab[JBD2_MAX_SLABS];
2566 static const char *jbd2_slab_names[JBD2_MAX_SLABS] = {
2567 "jbd2_1k", "jbd2_2k", "jbd2_4k", "jbd2_8k",
2568 "jbd2_16k", "jbd2_32k", "jbd2_64k", "jbd2_128k"
2572 static void jbd2_journal_destroy_slabs(void)
2576 for (i = 0; i < JBD2_MAX_SLABS; i++) {
2577 kmem_cache_destroy(jbd2_slab[i]);
2578 jbd2_slab[i] = NULL;
2582 static int jbd2_journal_create_slab(size_t size)
2584 static DEFINE_MUTEX(jbd2_slab_create_mutex);
2585 int i = order_base_2(size) - 10;
2588 if (size == PAGE_SIZE)
2591 if (i >= JBD2_MAX_SLABS)
2594 if (unlikely(i < 0))
2596 mutex_lock(&jbd2_slab_create_mutex);
2598 mutex_unlock(&jbd2_slab_create_mutex);
2599 return 0; /* Already created */
2602 slab_size = 1 << (i+10);
2603 jbd2_slab[i] = kmem_cache_create(jbd2_slab_names[i], slab_size,
2604 slab_size, 0, NULL);
2605 mutex_unlock(&jbd2_slab_create_mutex);
2606 if (!jbd2_slab[i]) {
2607 printk(KERN_EMERG "JBD2: no memory for jbd2_slab cache\n");
2613 static struct kmem_cache *get_slab(size_t size)
2615 int i = order_base_2(size) - 10;
2617 BUG_ON(i >= JBD2_MAX_SLABS);
2618 if (unlikely(i < 0))
2620 BUG_ON(jbd2_slab[i] == NULL);
2621 return jbd2_slab[i];
2624 void *jbd2_alloc(size_t size, gfp_t flags)
2628 BUG_ON(size & (size-1)); /* Must be a power of 2 */
2630 if (size < PAGE_SIZE)
2631 ptr = kmem_cache_alloc(get_slab(size), flags);
2633 ptr = (void *)__get_free_pages(flags, get_order(size));
2635 /* Check alignment; SLUB has gotten this wrong in the past,
2636 * and this can lead to user data corruption! */
2637 BUG_ON(((unsigned long) ptr) & (size-1));
2642 void jbd2_free(void *ptr, size_t size)
2644 if (size < PAGE_SIZE)
2645 kmem_cache_free(get_slab(size), ptr);
2647 free_pages((unsigned long)ptr, get_order(size));
2651 * Journal_head storage management
2653 static struct kmem_cache *jbd2_journal_head_cache;
2654 #ifdef CONFIG_JBD2_DEBUG
2655 static atomic_t nr_journal_heads = ATOMIC_INIT(0);
2658 static int __init jbd2_journal_init_journal_head_cache(void)
2660 J_ASSERT(!jbd2_journal_head_cache);
2661 jbd2_journal_head_cache = kmem_cache_create("jbd2_journal_head",
2662 sizeof(struct journal_head),
2664 SLAB_TEMPORARY | SLAB_TYPESAFE_BY_RCU,
2666 if (!jbd2_journal_head_cache) {
2667 printk(KERN_EMERG "JBD2: no memory for journal_head cache\n");
2673 static void jbd2_journal_destroy_journal_head_cache(void)
2675 kmem_cache_destroy(jbd2_journal_head_cache);
2676 jbd2_journal_head_cache = NULL;
2680 * journal_head splicing and dicing
2682 static struct journal_head *journal_alloc_journal_head(void)
2684 struct journal_head *ret;
2686 #ifdef CONFIG_JBD2_DEBUG
2687 atomic_inc(&nr_journal_heads);
2689 ret = kmem_cache_zalloc(jbd2_journal_head_cache, GFP_NOFS);
2691 jbd_debug(1, "out of memory for journal_head\n");
2692 pr_notice_ratelimited("ENOMEM in %s, retrying.\n", __func__);
2693 ret = kmem_cache_zalloc(jbd2_journal_head_cache,
2694 GFP_NOFS | __GFP_NOFAIL);
2697 spin_lock_init(&ret->b_state_lock);
2701 static void journal_free_journal_head(struct journal_head *jh)
2703 #ifdef CONFIG_JBD2_DEBUG
2704 atomic_dec(&nr_journal_heads);
2705 memset(jh, JBD2_POISON_FREE, sizeof(*jh));
2707 kmem_cache_free(jbd2_journal_head_cache, jh);
2711 * A journal_head is attached to a buffer_head whenever JBD has an
2712 * interest in the buffer.
2714 * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit
2715 * is set. This bit is tested in core kernel code where we need to take
2716 * JBD-specific actions. Testing the zeroness of ->b_private is not reliable
2719 * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one.
2721 * When a buffer has its BH_JBD bit set it is immune from being released by
2722 * core kernel code, mainly via ->b_count.
2724 * A journal_head is detached from its buffer_head when the journal_head's
2725 * b_jcount reaches zero. Running transaction (b_transaction) and checkpoint
2726 * transaction (b_cp_transaction) hold their references to b_jcount.
2728 * Various places in the kernel want to attach a journal_head to a buffer_head
2729 * _before_ attaching the journal_head to a transaction. To protect the
2730 * journal_head in this situation, jbd2_journal_add_journal_head elevates the
2731 * journal_head's b_jcount refcount by one. The caller must call
2732 * jbd2_journal_put_journal_head() to undo this.
2734 * So the typical usage would be:
2736 * (Attach a journal_head if needed. Increments b_jcount)
2737 * struct journal_head *jh = jbd2_journal_add_journal_head(bh);
2739 * (Get another reference for transaction)
2740 * jbd2_journal_grab_journal_head(bh);
2741 * jh->b_transaction = xxx;
2742 * (Put original reference)
2743 * jbd2_journal_put_journal_head(jh);
2747 * Give a buffer_head a journal_head.
2751 struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh)
2753 struct journal_head *jh;
2754 struct journal_head *new_jh = NULL;
2757 if (!buffer_jbd(bh))
2758 new_jh = journal_alloc_journal_head();
2760 jbd_lock_bh_journal_head(bh);
2761 if (buffer_jbd(bh)) {
2765 (atomic_read(&bh->b_count) > 0) ||
2766 (bh->b_page && bh->b_page->mapping));
2769 jbd_unlock_bh_journal_head(bh);
2774 new_jh = NULL; /* We consumed it */
2779 BUFFER_TRACE(bh, "added journal_head");
2782 jbd_unlock_bh_journal_head(bh);
2784 journal_free_journal_head(new_jh);
2785 return bh->b_private;
2789 * Grab a ref against this buffer_head's journal_head. If it ended up not
2790 * having a journal_head, return NULL
2792 struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh)
2794 struct journal_head *jh = NULL;
2796 jbd_lock_bh_journal_head(bh);
2797 if (buffer_jbd(bh)) {
2801 jbd_unlock_bh_journal_head(bh);
2804 EXPORT_SYMBOL(jbd2_journal_grab_journal_head);
2806 static void __journal_remove_journal_head(struct buffer_head *bh)
2808 struct journal_head *jh = bh2jh(bh);
2810 J_ASSERT_JH(jh, jh->b_transaction == NULL);
2811 J_ASSERT_JH(jh, jh->b_next_transaction == NULL);
2812 J_ASSERT_JH(jh, jh->b_cp_transaction == NULL);
2813 J_ASSERT_JH(jh, jh->b_jlist == BJ_None);
2814 J_ASSERT_BH(bh, buffer_jbd(bh));
2815 J_ASSERT_BH(bh, jh2bh(jh) == bh);
2816 BUFFER_TRACE(bh, "remove journal_head");
2818 /* Unlink before dropping the lock */
2819 bh->b_private = NULL;
2820 jh->b_bh = NULL; /* debug, really */
2821 clear_buffer_jbd(bh);
2824 static void journal_release_journal_head(struct journal_head *jh, size_t b_size)
2826 if (jh->b_frozen_data) {
2827 printk(KERN_WARNING "%s: freeing b_frozen_data\n", __func__);
2828 jbd2_free(jh->b_frozen_data, b_size);
2830 if (jh->b_committed_data) {
2831 printk(KERN_WARNING "%s: freeing b_committed_data\n", __func__);
2832 jbd2_free(jh->b_committed_data, b_size);
2834 journal_free_journal_head(jh);
2838 * Drop a reference on the passed journal_head. If it fell to zero then
2839 * release the journal_head from the buffer_head.
2841 void jbd2_journal_put_journal_head(struct journal_head *jh)
2843 struct buffer_head *bh = jh2bh(jh);
2845 jbd_lock_bh_journal_head(bh);
2846 J_ASSERT_JH(jh, jh->b_jcount > 0);
2848 if (!jh->b_jcount) {
2849 __journal_remove_journal_head(bh);
2850 jbd_unlock_bh_journal_head(bh);
2851 journal_release_journal_head(jh, bh->b_size);
2854 jbd_unlock_bh_journal_head(bh);
2857 EXPORT_SYMBOL(jbd2_journal_put_journal_head);
2860 * Initialize jbd inode head
2862 void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode)
2864 jinode->i_transaction = NULL;
2865 jinode->i_next_transaction = NULL;
2866 jinode->i_vfs_inode = inode;
2867 jinode->i_flags = 0;
2868 jinode->i_dirty_start = 0;
2869 jinode->i_dirty_end = 0;
2870 INIT_LIST_HEAD(&jinode->i_list);
2874 * Function to be called before we start removing inode from memory (i.e.,
2875 * clear_inode() is a fine place to be called from). It removes inode from
2876 * transaction's lists.
2878 void jbd2_journal_release_jbd_inode(journal_t *journal,
2879 struct jbd2_inode *jinode)
2884 spin_lock(&journal->j_list_lock);
2885 /* Is commit writing out inode - we have to wait */
2886 if (jinode->i_flags & JI_COMMIT_RUNNING) {
2887 wait_queue_head_t *wq;
2888 DEFINE_WAIT_BIT(wait, &jinode->i_flags, __JI_COMMIT_RUNNING);
2889 wq = bit_waitqueue(&jinode->i_flags, __JI_COMMIT_RUNNING);
2890 prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE);
2891 spin_unlock(&journal->j_list_lock);
2893 finish_wait(wq, &wait.wq_entry);
2897 if (jinode->i_transaction) {
2898 list_del(&jinode->i_list);
2899 jinode->i_transaction = NULL;
2901 spin_unlock(&journal->j_list_lock);
2905 #ifdef CONFIG_PROC_FS
2907 #define JBD2_STATS_PROC_NAME "fs/jbd2"
2909 static void __init jbd2_create_jbd_stats_proc_entry(void)
2911 proc_jbd2_stats = proc_mkdir(JBD2_STATS_PROC_NAME, NULL);
2914 static void __exit jbd2_remove_jbd_stats_proc_entry(void)
2916 if (proc_jbd2_stats)
2917 remove_proc_entry(JBD2_STATS_PROC_NAME, NULL);
2922 #define jbd2_create_jbd_stats_proc_entry() do {} while (0)
2923 #define jbd2_remove_jbd_stats_proc_entry() do {} while (0)
2927 struct kmem_cache *jbd2_handle_cache, *jbd2_inode_cache;
2929 static int __init jbd2_journal_init_inode_cache(void)
2931 J_ASSERT(!jbd2_inode_cache);
2932 jbd2_inode_cache = KMEM_CACHE(jbd2_inode, 0);
2933 if (!jbd2_inode_cache) {
2934 pr_emerg("JBD2: failed to create inode cache\n");
2940 static int __init jbd2_journal_init_handle_cache(void)
2942 J_ASSERT(!jbd2_handle_cache);
2943 jbd2_handle_cache = KMEM_CACHE(jbd2_journal_handle, SLAB_TEMPORARY);
2944 if (!jbd2_handle_cache) {
2945 printk(KERN_EMERG "JBD2: failed to create handle cache\n");
2951 static void jbd2_journal_destroy_inode_cache(void)
2953 kmem_cache_destroy(jbd2_inode_cache);
2954 jbd2_inode_cache = NULL;
2957 static void jbd2_journal_destroy_handle_cache(void)
2959 kmem_cache_destroy(jbd2_handle_cache);
2960 jbd2_handle_cache = NULL;
2964 * Module startup and shutdown
2967 static int __init journal_init_caches(void)
2971 ret = jbd2_journal_init_revoke_record_cache();
2973 ret = jbd2_journal_init_revoke_table_cache();
2975 ret = jbd2_journal_init_journal_head_cache();
2977 ret = jbd2_journal_init_handle_cache();
2979 ret = jbd2_journal_init_inode_cache();
2981 ret = jbd2_journal_init_transaction_cache();
2985 static void jbd2_journal_destroy_caches(void)
2987 jbd2_journal_destroy_revoke_record_cache();
2988 jbd2_journal_destroy_revoke_table_cache();
2989 jbd2_journal_destroy_journal_head_cache();
2990 jbd2_journal_destroy_handle_cache();
2991 jbd2_journal_destroy_inode_cache();
2992 jbd2_journal_destroy_transaction_cache();
2993 jbd2_journal_destroy_slabs();
2996 static int __init journal_init(void)
3000 BUILD_BUG_ON(sizeof(struct journal_superblock_s) != 1024);
3002 ret = journal_init_caches();
3004 jbd2_create_jbd_stats_proc_entry();
3006 jbd2_journal_destroy_caches();
3011 static void __exit journal_exit(void)
3013 #ifdef CONFIG_JBD2_DEBUG
3014 int n = atomic_read(&nr_journal_heads);
3016 printk(KERN_ERR "JBD2: leaked %d journal_heads!\n", n);
3018 jbd2_remove_jbd_stats_proc_entry();
3019 jbd2_journal_destroy_caches();
3022 MODULE_LICENSE("GPL");
3023 module_init(journal_init);
3024 module_exit(journal_exit);