2 * linux/fs/jbd2/journal.c
4 * Written by Stephen C. Tweedie <sct@redhat.com>, 1998
6 * Copyright 1998 Red Hat corp --- All Rights Reserved
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.
12 * Generic filesystem journal-writing code; part of the ext2fs
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.
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).
25 #include <linux/module.h>
26 #include <linux/time.h>
28 #include <linux/jbd2.h>
29 #include <linux/errno.h>
30 #include <linux/slab.h>
31 #include <linux/init.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/debugfs.h>
39 #include <linux/seq_file.h>
40 #include <linux/math64.h>
41 #include <linux/hash.h>
42 #include <linux/log2.h>
43 #include <linux/vmalloc.h>
44 #include <linux/backing-dev.h>
45 #include <linux/bitops.h>
46 #include <linux/ratelimit.h>
48 #define CREATE_TRACE_POINTS
49 #include <trace/events/jbd2.h>
51 #include <asm/uaccess.h>
54 EXPORT_SYMBOL(jbd2_journal_extend);
55 EXPORT_SYMBOL(jbd2_journal_stop);
56 EXPORT_SYMBOL(jbd2_journal_lock_updates);
57 EXPORT_SYMBOL(jbd2_journal_unlock_updates);
58 EXPORT_SYMBOL(jbd2_journal_get_write_access);
59 EXPORT_SYMBOL(jbd2_journal_get_create_access);
60 EXPORT_SYMBOL(jbd2_journal_get_undo_access);
61 EXPORT_SYMBOL(jbd2_journal_set_triggers);
62 EXPORT_SYMBOL(jbd2_journal_dirty_metadata);
63 EXPORT_SYMBOL(jbd2_journal_release_buffer);
64 EXPORT_SYMBOL(jbd2_journal_forget);
66 EXPORT_SYMBOL(journal_sync_buffer);
68 EXPORT_SYMBOL(jbd2_journal_flush);
69 EXPORT_SYMBOL(jbd2_journal_revoke);
71 EXPORT_SYMBOL(jbd2_journal_init_dev);
72 EXPORT_SYMBOL(jbd2_journal_init_inode);
73 EXPORT_SYMBOL(jbd2_journal_check_used_features);
74 EXPORT_SYMBOL(jbd2_journal_check_available_features);
75 EXPORT_SYMBOL(jbd2_journal_set_features);
76 EXPORT_SYMBOL(jbd2_journal_load);
77 EXPORT_SYMBOL(jbd2_journal_destroy);
78 EXPORT_SYMBOL(jbd2_journal_abort);
79 EXPORT_SYMBOL(jbd2_journal_errno);
80 EXPORT_SYMBOL(jbd2_journal_ack_err);
81 EXPORT_SYMBOL(jbd2_journal_clear_err);
82 EXPORT_SYMBOL(jbd2_log_wait_commit);
83 EXPORT_SYMBOL(jbd2_log_start_commit);
84 EXPORT_SYMBOL(jbd2_journal_start_commit);
85 EXPORT_SYMBOL(jbd2_journal_force_commit_nested);
86 EXPORT_SYMBOL(jbd2_journal_wipe);
87 EXPORT_SYMBOL(jbd2_journal_blocks_per_page);
88 EXPORT_SYMBOL(jbd2_journal_invalidatepage);
89 EXPORT_SYMBOL(jbd2_journal_try_to_free_buffers);
90 EXPORT_SYMBOL(jbd2_journal_force_commit);
91 EXPORT_SYMBOL(jbd2_journal_file_inode);
92 EXPORT_SYMBOL(jbd2_journal_init_jbd_inode);
93 EXPORT_SYMBOL(jbd2_journal_release_jbd_inode);
94 EXPORT_SYMBOL(jbd2_journal_begin_ordered_truncate);
95 EXPORT_SYMBOL(jbd2_inode_cache);
97 static void __journal_abort_soft (journal_t *journal, int errno);
98 static int jbd2_journal_create_slab(size_t slab_size);
101 * Helper function used to manage commit timeouts
104 static void commit_timeout(unsigned long __data)
106 struct task_struct * p = (struct task_struct *) __data;
112 * kjournald2: The main thread function used to manage a logging device
115 * This kernel thread is responsible for two things:
117 * 1) COMMIT: Every so often we need to commit the current state of the
118 * filesystem to disk. The journal thread is responsible for writing
119 * all of the metadata buffers to disk.
121 * 2) CHECKPOINT: We cannot reuse a used section of the log file until all
122 * of the data in that part of the log has been rewritten elsewhere on
123 * the disk. Flushing these old buffers to reclaim space in the log is
124 * known as checkpointing, and this thread is responsible for that job.
127 static int kjournald2(void *arg)
129 journal_t *journal = arg;
130 transaction_t *transaction;
133 * Set up an interval timer which can be used to trigger a commit wakeup
134 * after the commit interval expires
136 setup_timer(&journal->j_commit_timer, commit_timeout,
137 (unsigned long)current);
141 /* Record that the journal thread is running */
142 journal->j_task = current;
143 wake_up(&journal->j_wait_done_commit);
146 * And now, wait forever for commit wakeup events.
148 write_lock(&journal->j_state_lock);
151 if (journal->j_flags & JBD2_UNMOUNT)
154 jbd_debug(1, "commit_sequence=%d, commit_request=%d\n",
155 journal->j_commit_sequence, journal->j_commit_request);
157 if (journal->j_commit_sequence != journal->j_commit_request) {
158 jbd_debug(1, "OK, requests differ\n");
159 write_unlock(&journal->j_state_lock);
160 del_timer_sync(&journal->j_commit_timer);
161 jbd2_journal_commit_transaction(journal);
162 write_lock(&journal->j_state_lock);
166 wake_up(&journal->j_wait_done_commit);
167 if (freezing(current)) {
169 * The simpler the better. Flushing journal isn't a
170 * good idea, because that depends on threads that may
171 * be already stopped.
173 jbd_debug(1, "Now suspending kjournald2\n");
174 write_unlock(&journal->j_state_lock);
176 write_lock(&journal->j_state_lock);
179 * We assume on resume that commits are already there,
183 int should_sleep = 1;
185 prepare_to_wait(&journal->j_wait_commit, &wait,
187 if (journal->j_commit_sequence != journal->j_commit_request)
189 transaction = journal->j_running_transaction;
190 if (transaction && time_after_eq(jiffies,
191 transaction->t_expires))
193 if (journal->j_flags & JBD2_UNMOUNT)
196 write_unlock(&journal->j_state_lock);
198 write_lock(&journal->j_state_lock);
200 finish_wait(&journal->j_wait_commit, &wait);
203 jbd_debug(1, "kjournald2 wakes\n");
206 * Were we woken up by a commit wakeup event?
208 transaction = journal->j_running_transaction;
209 if (transaction && time_after_eq(jiffies, transaction->t_expires)) {
210 journal->j_commit_request = transaction->t_tid;
211 jbd_debug(1, "woke because of timeout\n");
216 write_unlock(&journal->j_state_lock);
217 del_timer_sync(&journal->j_commit_timer);
218 journal->j_task = NULL;
219 wake_up(&journal->j_wait_done_commit);
220 jbd_debug(1, "Journal thread exiting.\n");
224 static int jbd2_journal_start_thread(journal_t *journal)
226 struct task_struct *t;
228 t = kthread_run(kjournald2, journal, "jbd2/%s",
233 wait_event(journal->j_wait_done_commit, journal->j_task != NULL);
237 static void journal_kill_thread(journal_t *journal)
239 write_lock(&journal->j_state_lock);
240 journal->j_flags |= JBD2_UNMOUNT;
242 while (journal->j_task) {
243 wake_up(&journal->j_wait_commit);
244 write_unlock(&journal->j_state_lock);
245 wait_event(journal->j_wait_done_commit, journal->j_task == NULL);
246 write_lock(&journal->j_state_lock);
248 write_unlock(&journal->j_state_lock);
252 * jbd2_journal_write_metadata_buffer: write a metadata buffer to the journal.
254 * Writes a metadata buffer to a given disk block. The actual IO is not
255 * performed but a new buffer_head is constructed which labels the data
256 * to be written with the correct destination disk block.
258 * Any magic-number escaping which needs to be done will cause a
259 * copy-out here. If the buffer happens to start with the
260 * JBD2_MAGIC_NUMBER, then we can't write it to the log directly: the
261 * magic number is only written to the log for descripter blocks. In
262 * this case, we copy the data and replace the first word with 0, and we
263 * return a result code which indicates that this buffer needs to be
264 * marked as an escaped buffer in the corresponding log descriptor
265 * block. The missing word can then be restored when the block is read
268 * If the source buffer has already been modified by a new transaction
269 * since we took the last commit snapshot, we use the frozen copy of
270 * that data for IO. If we end up using the existing buffer_head's data
271 * for the write, then we *have* to lock the buffer to prevent anyone
272 * else from using and possibly modifying it while the IO is in
275 * The function returns a pointer to the buffer_heads to be used for IO.
277 * We assume that the journal has already been locked in this function.
284 * Bit 0 set == escape performed on the data
285 * Bit 1 set == buffer copy-out performed (kfree the data after IO)
288 int jbd2_journal_write_metadata_buffer(transaction_t *transaction,
289 struct journal_head *jh_in,
290 struct journal_head **jh_out,
291 unsigned long long blocknr)
293 int need_copy_out = 0;
294 int done_copy_out = 0;
297 struct buffer_head *new_bh;
298 struct journal_head *new_jh;
299 struct page *new_page;
300 unsigned int new_offset;
301 struct buffer_head *bh_in = jh2bh(jh_in);
302 journal_t *journal = transaction->t_journal;
305 * The buffer really shouldn't be locked: only the current committing
306 * transaction is allowed to write it, so nobody else is allowed
309 * akpm: except if we're journalling data, and write() output is
310 * also part of a shared mapping, and another thread has
311 * decided to launch a writepage() against this buffer.
313 J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in));
316 new_bh = alloc_buffer_head(GFP_NOFS);
319 * Failure is not an option, but __GFP_NOFAIL is going
320 * away; so we retry ourselves here.
322 congestion_wait(BLK_RW_ASYNC, HZ/50);
326 /* keep subsequent assertions sane */
328 init_buffer(new_bh, NULL, NULL);
329 atomic_set(&new_bh->b_count, 1);
330 new_jh = jbd2_journal_add_journal_head(new_bh); /* This sleeps */
333 * If a new transaction has already done a buffer copy-out, then
334 * we use that version of the data for the commit.
336 jbd_lock_bh_state(bh_in);
338 if (jh_in->b_frozen_data) {
340 new_page = virt_to_page(jh_in->b_frozen_data);
341 new_offset = offset_in_page(jh_in->b_frozen_data);
343 new_page = jh2bh(jh_in)->b_page;
344 new_offset = offset_in_page(jh2bh(jh_in)->b_data);
347 mapped_data = kmap_atomic(new_page);
349 * Fire data frozen trigger if data already wasn't frozen. Do this
350 * before checking for escaping, as the trigger may modify the magic
351 * offset. If a copy-out happens afterwards, it will have the correct
352 * data in the buffer.
355 jbd2_buffer_frozen_trigger(jh_in, mapped_data + new_offset,
361 if (*((__be32 *)(mapped_data + new_offset)) ==
362 cpu_to_be32(JBD2_MAGIC_NUMBER)) {
366 kunmap_atomic(mapped_data);
369 * Do we need to do a data copy?
371 if (need_copy_out && !done_copy_out) {
374 jbd_unlock_bh_state(bh_in);
375 tmp = jbd2_alloc(bh_in->b_size, GFP_NOFS);
377 jbd2_journal_put_journal_head(new_jh);
380 jbd_lock_bh_state(bh_in);
381 if (jh_in->b_frozen_data) {
382 jbd2_free(tmp, bh_in->b_size);
386 jh_in->b_frozen_data = tmp;
387 mapped_data = kmap_atomic(new_page);
388 memcpy(tmp, mapped_data + new_offset, jh2bh(jh_in)->b_size);
389 kunmap_atomic(mapped_data);
391 new_page = virt_to_page(tmp);
392 new_offset = offset_in_page(tmp);
396 * This isn't strictly necessary, as we're using frozen
397 * data for the escaping, but it keeps consistency with
398 * b_frozen_data usage.
400 jh_in->b_frozen_triggers = jh_in->b_triggers;
404 * Did we need to do an escaping? Now we've done all the
405 * copying, we can finally do so.
408 mapped_data = kmap_atomic(new_page);
409 *((unsigned int *)(mapped_data + new_offset)) = 0;
410 kunmap_atomic(mapped_data);
413 set_bh_page(new_bh, new_page, new_offset);
414 new_jh->b_transaction = NULL;
415 new_bh->b_size = jh2bh(jh_in)->b_size;
416 new_bh->b_bdev = transaction->t_journal->j_dev;
417 new_bh->b_blocknr = blocknr;
418 set_buffer_mapped(new_bh);
419 set_buffer_dirty(new_bh);
424 * The to-be-written buffer needs to get moved to the io queue,
425 * and the original buffer whose contents we are shadowing or
426 * copying is moved to the transaction's shadow queue.
428 JBUFFER_TRACE(jh_in, "file as BJ_Shadow");
429 spin_lock(&journal->j_list_lock);
430 __jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow);
431 spin_unlock(&journal->j_list_lock);
432 jbd_unlock_bh_state(bh_in);
434 JBUFFER_TRACE(new_jh, "file as BJ_IO");
435 jbd2_journal_file_buffer(new_jh, transaction, BJ_IO);
437 return do_escape | (done_copy_out << 1);
441 * Allocation code for the journal file. Manage the space left in the
442 * journal, so that we can begin checkpointing when appropriate.
446 * __jbd2_log_space_left: Return the number of free blocks left in the journal.
448 * Called with the journal already locked.
450 * Called under j_state_lock
453 int __jbd2_log_space_left(journal_t *journal)
455 int left = journal->j_free;
457 /* assert_spin_locked(&journal->j_state_lock); */
460 * Be pessimistic here about the number of those free blocks which
461 * might be required for log descriptor control blocks.
464 #define MIN_LOG_RESERVED_BLOCKS 32 /* Allow for rounding errors */
466 left -= MIN_LOG_RESERVED_BLOCKS;
475 * Called with j_state_lock locked for writing.
476 * Returns true if a transaction commit was started.
478 int __jbd2_log_start_commit(journal_t *journal, tid_t target)
481 * The only transaction we can possibly wait upon is the
482 * currently running transaction (if it exists). Otherwise,
483 * the target tid must be an old one.
485 if (journal->j_running_transaction &&
486 journal->j_running_transaction->t_tid == target) {
488 * We want a new commit: OK, mark the request and wakeup the
489 * commit thread. We do _not_ do the commit ourselves.
492 journal->j_commit_request = target;
493 jbd_debug(1, "JBD2: requesting commit %d/%d\n",
494 journal->j_commit_request,
495 journal->j_commit_sequence);
496 wake_up(&journal->j_wait_commit);
498 } else if (!tid_geq(journal->j_commit_request, target))
499 /* This should never happen, but if it does, preserve
500 the evidence before kjournald goes into a loop and
501 increments j_commit_sequence beyond all recognition. */
502 WARN_ONCE(1, "JBD2: bad log_start_commit: %u %u %u %u\n",
503 journal->j_commit_request,
504 journal->j_commit_sequence,
505 target, journal->j_running_transaction ?
506 journal->j_running_transaction->t_tid : 0);
510 int jbd2_log_start_commit(journal_t *journal, tid_t tid)
514 write_lock(&journal->j_state_lock);
515 ret = __jbd2_log_start_commit(journal, tid);
516 write_unlock(&journal->j_state_lock);
521 * Force and wait upon a commit if the calling process is not within
522 * transaction. This is used for forcing out undo-protected data which contains
523 * bitmaps, when the fs is running out of space.
525 * We can only force the running transaction if we don't have an active handle;
526 * otherwise, we will deadlock.
528 * Returns true if a transaction was started.
530 int jbd2_journal_force_commit_nested(journal_t *journal)
532 transaction_t *transaction = NULL;
534 int need_to_start = 0;
536 read_lock(&journal->j_state_lock);
537 if (journal->j_running_transaction && !current->journal_info) {
538 transaction = journal->j_running_transaction;
539 if (!tid_geq(journal->j_commit_request, transaction->t_tid))
541 } else if (journal->j_committing_transaction)
542 transaction = journal->j_committing_transaction;
545 read_unlock(&journal->j_state_lock);
546 return 0; /* Nothing to retry */
549 tid = transaction->t_tid;
550 read_unlock(&journal->j_state_lock);
552 jbd2_log_start_commit(journal, tid);
553 jbd2_log_wait_commit(journal, tid);
558 * Start a commit of the current running transaction (if any). Returns true
559 * if a transaction is going to be committed (or is currently already
560 * committing), and fills its tid in at *ptid
562 int jbd2_journal_start_commit(journal_t *journal, tid_t *ptid)
566 write_lock(&journal->j_state_lock);
567 if (journal->j_running_transaction) {
568 tid_t tid = journal->j_running_transaction->t_tid;
570 __jbd2_log_start_commit(journal, tid);
571 /* There's a running transaction and we've just made sure
572 * it's commit has been scheduled. */
576 } else if (journal->j_committing_transaction) {
578 * If ext3_write_super() recently started a commit, then we
579 * have to wait for completion of that transaction
582 *ptid = journal->j_committing_transaction->t_tid;
585 write_unlock(&journal->j_state_lock);
590 * Return 1 if a given transaction has not yet sent barrier request
591 * connected with a transaction commit. If 0 is returned, transaction
592 * may or may not have sent the barrier. Used to avoid sending barrier
593 * twice in common cases.
595 int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid)
598 transaction_t *commit_trans;
600 if (!(journal->j_flags & JBD2_BARRIER))
602 read_lock(&journal->j_state_lock);
603 /* Transaction already committed? */
604 if (tid_geq(journal->j_commit_sequence, tid))
606 commit_trans = journal->j_committing_transaction;
607 if (!commit_trans || commit_trans->t_tid != tid) {
612 * Transaction is being committed and we already proceeded to
613 * submitting a flush to fs partition?
615 if (journal->j_fs_dev != journal->j_dev) {
616 if (!commit_trans->t_need_data_flush ||
617 commit_trans->t_state >= T_COMMIT_DFLUSH)
620 if (commit_trans->t_state >= T_COMMIT_JFLUSH)
625 read_unlock(&journal->j_state_lock);
628 EXPORT_SYMBOL(jbd2_trans_will_send_data_barrier);
631 * Wait for a specified commit to complete.
632 * The caller may not hold the journal lock.
634 int jbd2_log_wait_commit(journal_t *journal, tid_t tid)
638 read_lock(&journal->j_state_lock);
639 #ifdef CONFIG_JBD2_DEBUG
640 if (!tid_geq(journal->j_commit_request, tid)) {
642 "%s: error: j_commit_request=%d, tid=%d\n",
643 __func__, journal->j_commit_request, tid);
646 while (tid_gt(tid, journal->j_commit_sequence)) {
647 jbd_debug(1, "JBD2: want %d, j_commit_sequence=%d\n",
648 tid, journal->j_commit_sequence);
649 wake_up(&journal->j_wait_commit);
650 read_unlock(&journal->j_state_lock);
651 wait_event(journal->j_wait_done_commit,
652 !tid_gt(tid, journal->j_commit_sequence));
653 read_lock(&journal->j_state_lock);
655 read_unlock(&journal->j_state_lock);
657 if (unlikely(is_journal_aborted(journal))) {
658 printk(KERN_EMERG "journal commit I/O error\n");
665 * Log buffer allocation routines:
668 int jbd2_journal_next_log_block(journal_t *journal, unsigned long long *retp)
670 unsigned long blocknr;
672 write_lock(&journal->j_state_lock);
673 J_ASSERT(journal->j_free > 1);
675 blocknr = journal->j_head;
678 if (journal->j_head == journal->j_last)
679 journal->j_head = journal->j_first;
680 write_unlock(&journal->j_state_lock);
681 return jbd2_journal_bmap(journal, blocknr, retp);
685 * Conversion of logical to physical block numbers for the journal
687 * On external journals the journal blocks are identity-mapped, so
688 * this is a no-op. If needed, we can use j_blk_offset - everything is
691 int jbd2_journal_bmap(journal_t *journal, unsigned long blocknr,
692 unsigned long long *retp)
695 unsigned long long ret;
697 if (journal->j_inode) {
698 ret = bmap(journal->j_inode, blocknr);
702 printk(KERN_ALERT "%s: journal block not found "
703 "at offset %lu on %s\n",
704 __func__, blocknr, journal->j_devname);
706 __journal_abort_soft(journal, err);
709 *retp = blocknr; /* +journal->j_blk_offset */
715 * We play buffer_head aliasing tricks to write data/metadata blocks to
716 * the journal without copying their contents, but for journal
717 * descriptor blocks we do need to generate bona fide buffers.
719 * After the caller of jbd2_journal_get_descriptor_buffer() has finished modifying
720 * the buffer's contents they really should run flush_dcache_page(bh->b_page).
721 * But we don't bother doing that, so there will be coherency problems with
722 * mmaps of blockdevs which hold live JBD-controlled filesystems.
724 struct journal_head *jbd2_journal_get_descriptor_buffer(journal_t *journal)
726 struct buffer_head *bh;
727 unsigned long long blocknr;
730 err = jbd2_journal_next_log_block(journal, &blocknr);
735 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
739 memset(bh->b_data, 0, journal->j_blocksize);
740 set_buffer_uptodate(bh);
742 BUFFER_TRACE(bh, "return this buffer");
743 return jbd2_journal_add_journal_head(bh);
747 * Return tid of the oldest transaction in the journal and block in the journal
748 * where the transaction starts.
750 * If the journal is now empty, return which will be the next transaction ID
751 * we will write and where will that transaction start.
753 * The return value is 0 if journal tail cannot be pushed any further, 1 if
756 int jbd2_journal_get_log_tail(journal_t *journal, tid_t *tid,
757 unsigned long *block)
759 transaction_t *transaction;
762 read_lock(&journal->j_state_lock);
763 spin_lock(&journal->j_list_lock);
764 transaction = journal->j_checkpoint_transactions;
766 *tid = transaction->t_tid;
767 *block = transaction->t_log_start;
768 } else if ((transaction = journal->j_committing_transaction) != NULL) {
769 *tid = transaction->t_tid;
770 *block = transaction->t_log_start;
771 } else if ((transaction = journal->j_running_transaction) != NULL) {
772 *tid = transaction->t_tid;
773 *block = journal->j_head;
775 *tid = journal->j_transaction_sequence;
776 *block = journal->j_head;
778 ret = tid_gt(*tid, journal->j_tail_sequence);
779 spin_unlock(&journal->j_list_lock);
780 read_unlock(&journal->j_state_lock);
786 * Update information in journal structure and in on disk journal superblock
787 * about log tail. This function does not check whether information passed in
788 * really pushes log tail further. It's responsibility of the caller to make
789 * sure provided log tail information is valid (e.g. by holding
790 * j_checkpoint_mutex all the time between computing log tail and calling this
791 * function as is the case with jbd2_cleanup_journal_tail()).
793 * Requires j_checkpoint_mutex
795 void __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block)
799 BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
802 * We cannot afford for write to remain in drive's caches since as
803 * soon as we update j_tail, next transaction can start reusing journal
804 * space and if we lose sb update during power failure we'd replay
805 * old transaction with possibly newly overwritten data.
807 jbd2_journal_update_sb_log_tail(journal, tid, block, WRITE_FUA);
808 write_lock(&journal->j_state_lock);
809 freed = block - journal->j_tail;
810 if (block < journal->j_tail)
811 freed += journal->j_last - journal->j_first;
813 trace_jbd2_update_log_tail(journal, tid, block, freed);
815 "Cleaning journal tail from %d to %d (offset %lu), "
817 journal->j_tail_sequence, tid, block, freed);
819 journal->j_free += freed;
820 journal->j_tail_sequence = tid;
821 journal->j_tail = block;
822 write_unlock(&journal->j_state_lock);
826 * This is a variaon of __jbd2_update_log_tail which checks for validity of
827 * provided log tail and locks j_checkpoint_mutex. So it is safe against races
828 * with other threads updating log tail.
830 void jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block)
832 mutex_lock(&journal->j_checkpoint_mutex);
833 if (tid_gt(tid, journal->j_tail_sequence))
834 __jbd2_update_log_tail(journal, tid, block);
835 mutex_unlock(&journal->j_checkpoint_mutex);
838 struct jbd2_stats_proc_session {
840 struct transaction_stats_s *stats;
845 static void *jbd2_seq_info_start(struct seq_file *seq, loff_t *pos)
847 return *pos ? NULL : SEQ_START_TOKEN;
850 static void *jbd2_seq_info_next(struct seq_file *seq, void *v, loff_t *pos)
855 static int jbd2_seq_info_show(struct seq_file *seq, void *v)
857 struct jbd2_stats_proc_session *s = seq->private;
859 if (v != SEQ_START_TOKEN)
861 seq_printf(seq, "%lu transaction, each up to %u blocks\n",
863 s->journal->j_max_transaction_buffers);
864 if (s->stats->ts_tid == 0)
866 seq_printf(seq, "average: \n %ums waiting for transaction\n",
867 jiffies_to_msecs(s->stats->run.rs_wait / s->stats->ts_tid));
868 seq_printf(seq, " %ums running transaction\n",
869 jiffies_to_msecs(s->stats->run.rs_running / s->stats->ts_tid));
870 seq_printf(seq, " %ums transaction was being locked\n",
871 jiffies_to_msecs(s->stats->run.rs_locked / s->stats->ts_tid));
872 seq_printf(seq, " %ums flushing data (in ordered mode)\n",
873 jiffies_to_msecs(s->stats->run.rs_flushing / s->stats->ts_tid));
874 seq_printf(seq, " %ums logging transaction\n",
875 jiffies_to_msecs(s->stats->run.rs_logging / s->stats->ts_tid));
876 seq_printf(seq, " %lluus average transaction commit time\n",
877 div_u64(s->journal->j_average_commit_time, 1000));
878 seq_printf(seq, " %lu handles per transaction\n",
879 s->stats->run.rs_handle_count / s->stats->ts_tid);
880 seq_printf(seq, " %lu blocks per transaction\n",
881 s->stats->run.rs_blocks / s->stats->ts_tid);
882 seq_printf(seq, " %lu logged blocks per transaction\n",
883 s->stats->run.rs_blocks_logged / s->stats->ts_tid);
887 static void jbd2_seq_info_stop(struct seq_file *seq, void *v)
891 static const struct seq_operations jbd2_seq_info_ops = {
892 .start = jbd2_seq_info_start,
893 .next = jbd2_seq_info_next,
894 .stop = jbd2_seq_info_stop,
895 .show = jbd2_seq_info_show,
898 static int jbd2_seq_info_open(struct inode *inode, struct file *file)
900 journal_t *journal = PDE(inode)->data;
901 struct jbd2_stats_proc_session *s;
904 s = kmalloc(sizeof(*s), GFP_KERNEL);
907 size = sizeof(struct transaction_stats_s);
908 s->stats = kmalloc(size, GFP_KERNEL);
909 if (s->stats == NULL) {
913 spin_lock(&journal->j_history_lock);
914 memcpy(s->stats, &journal->j_stats, size);
915 s->journal = journal;
916 spin_unlock(&journal->j_history_lock);
918 rc = seq_open(file, &jbd2_seq_info_ops);
920 struct seq_file *m = file->private_data;
930 static int jbd2_seq_info_release(struct inode *inode, struct file *file)
932 struct seq_file *seq = file->private_data;
933 struct jbd2_stats_proc_session *s = seq->private;
936 return seq_release(inode, file);
939 static const struct file_operations jbd2_seq_info_fops = {
940 .owner = THIS_MODULE,
941 .open = jbd2_seq_info_open,
944 .release = jbd2_seq_info_release,
947 static struct proc_dir_entry *proc_jbd2_stats;
949 static void jbd2_stats_proc_init(journal_t *journal)
951 journal->j_proc_entry = proc_mkdir(journal->j_devname, proc_jbd2_stats);
952 if (journal->j_proc_entry) {
953 proc_create_data("info", S_IRUGO, journal->j_proc_entry,
954 &jbd2_seq_info_fops, journal);
958 static void jbd2_stats_proc_exit(journal_t *journal)
960 remove_proc_entry("info", journal->j_proc_entry);
961 remove_proc_entry(journal->j_devname, proc_jbd2_stats);
965 * Management for journal control blocks: functions to create and
966 * destroy journal_t structures, and to initialise and read existing
967 * journal blocks from disk. */
969 /* First: create and setup a journal_t object in memory. We initialise
970 * very few fields yet: that has to wait until we have created the
971 * journal structures from from scratch, or loaded them from disk. */
973 static journal_t * journal_init_common (void)
978 journal = kzalloc(sizeof(*journal), GFP_KERNEL);
982 init_waitqueue_head(&journal->j_wait_transaction_locked);
983 init_waitqueue_head(&journal->j_wait_logspace);
984 init_waitqueue_head(&journal->j_wait_done_commit);
985 init_waitqueue_head(&journal->j_wait_checkpoint);
986 init_waitqueue_head(&journal->j_wait_commit);
987 init_waitqueue_head(&journal->j_wait_updates);
988 mutex_init(&journal->j_barrier);
989 mutex_init(&journal->j_checkpoint_mutex);
990 spin_lock_init(&journal->j_revoke_lock);
991 spin_lock_init(&journal->j_list_lock);
992 rwlock_init(&journal->j_state_lock);
994 journal->j_commit_interval = (HZ * JBD2_DEFAULT_MAX_COMMIT_AGE);
995 journal->j_min_batch_time = 0;
996 journal->j_max_batch_time = 15000; /* 15ms */
998 /* The journal is marked for error until we succeed with recovery! */
999 journal->j_flags = JBD2_ABORT;
1001 /* Set up a default-sized revoke table for the new mount. */
1002 err = jbd2_journal_init_revoke(journal, JOURNAL_REVOKE_DEFAULT_HASH);
1008 spin_lock_init(&journal->j_history_lock);
1013 /* jbd2_journal_init_dev and jbd2_journal_init_inode:
1015 * Create a journal structure assigned some fixed set of disk blocks to
1016 * the journal. We don't actually touch those disk blocks yet, but we
1017 * need to set up all of the mapping information to tell the journaling
1018 * system where the journal blocks are.
1023 * journal_t * jbd2_journal_init_dev() - creates and initialises a journal structure
1024 * @bdev: Block device on which to create the journal
1025 * @fs_dev: Device which hold journalled filesystem for this journal.
1026 * @start: Block nr Start of journal.
1027 * @len: Length of the journal in blocks.
1028 * @blocksize: blocksize of journalling device
1030 * Returns: a newly created journal_t *
1032 * jbd2_journal_init_dev creates a journal which maps a fixed contiguous
1033 * range of blocks on an arbitrary block device.
1036 journal_t * jbd2_journal_init_dev(struct block_device *bdev,
1037 struct block_device *fs_dev,
1038 unsigned long long start, int len, int blocksize)
1040 journal_t *journal = journal_init_common();
1041 struct buffer_head *bh;
1048 /* journal descriptor can store up to n blocks -bzzz */
1049 journal->j_blocksize = blocksize;
1050 journal->j_dev = bdev;
1051 journal->j_fs_dev = fs_dev;
1052 journal->j_blk_offset = start;
1053 journal->j_maxlen = len;
1054 bdevname(journal->j_dev, journal->j_devname);
1055 p = journal->j_devname;
1056 while ((p = strchr(p, '/')))
1058 jbd2_stats_proc_init(journal);
1059 n = journal->j_blocksize / sizeof(journal_block_tag_t);
1060 journal->j_wbufsize = n;
1061 journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
1062 if (!journal->j_wbuf) {
1063 printk(KERN_ERR "%s: Can't allocate bhs for commit thread\n",
1068 bh = __getblk(journal->j_dev, start, journal->j_blocksize);
1071 "%s: Cannot get buffer for journal superblock\n",
1075 journal->j_sb_buffer = bh;
1076 journal->j_superblock = (journal_superblock_t *)bh->b_data;
1080 kfree(journal->j_wbuf);
1081 jbd2_stats_proc_exit(journal);
1087 * journal_t * jbd2_journal_init_inode () - creates a journal which maps to a inode.
1088 * @inode: An inode to create the journal in
1090 * jbd2_journal_init_inode creates a journal which maps an on-disk inode as
1091 * the journal. The inode must exist already, must support bmap() and
1092 * must have all data blocks preallocated.
1094 journal_t * jbd2_journal_init_inode (struct inode *inode)
1096 struct buffer_head *bh;
1097 journal_t *journal = journal_init_common();
1101 unsigned long long blocknr;
1106 journal->j_dev = journal->j_fs_dev = inode->i_sb->s_bdev;
1107 journal->j_inode = inode;
1108 bdevname(journal->j_dev, journal->j_devname);
1109 p = journal->j_devname;
1110 while ((p = strchr(p, '/')))
1112 p = journal->j_devname + strlen(journal->j_devname);
1113 sprintf(p, "-%lu", journal->j_inode->i_ino);
1115 "journal %p: inode %s/%ld, size %Ld, bits %d, blksize %ld\n",
1116 journal, inode->i_sb->s_id, inode->i_ino,
1117 (long long) inode->i_size,
1118 inode->i_sb->s_blocksize_bits, inode->i_sb->s_blocksize);
1120 journal->j_maxlen = inode->i_size >> inode->i_sb->s_blocksize_bits;
1121 journal->j_blocksize = inode->i_sb->s_blocksize;
1122 jbd2_stats_proc_init(journal);
1124 /* journal descriptor can store up to n blocks -bzzz */
1125 n = journal->j_blocksize / sizeof(journal_block_tag_t);
1126 journal->j_wbufsize = n;
1127 journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
1128 if (!journal->j_wbuf) {
1129 printk(KERN_ERR "%s: Can't allocate bhs for commit thread\n",
1134 err = jbd2_journal_bmap(journal, 0, &blocknr);
1135 /* If that failed, give up */
1137 printk(KERN_ERR "%s: Cannot locate journal superblock\n",
1142 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
1145 "%s: Cannot get buffer for journal superblock\n",
1149 journal->j_sb_buffer = bh;
1150 journal->j_superblock = (journal_superblock_t *)bh->b_data;
1154 kfree(journal->j_wbuf);
1155 jbd2_stats_proc_exit(journal);
1161 * If the journal init or create aborts, we need to mark the journal
1162 * superblock as being NULL to prevent the journal destroy from writing
1163 * back a bogus superblock.
1165 static void journal_fail_superblock (journal_t *journal)
1167 struct buffer_head *bh = journal->j_sb_buffer;
1169 journal->j_sb_buffer = NULL;
1173 * Given a journal_t structure, initialise the various fields for
1174 * startup of a new journaling session. We use this both when creating
1175 * a journal, and after recovering an old journal to reset it for
1179 static int journal_reset(journal_t *journal)
1181 journal_superblock_t *sb = journal->j_superblock;
1182 unsigned long long first, last;
1184 first = be32_to_cpu(sb->s_first);
1185 last = be32_to_cpu(sb->s_maxlen);
1186 if (first + JBD2_MIN_JOURNAL_BLOCKS > last + 1) {
1187 printk(KERN_ERR "JBD2: Journal too short (blocks %llu-%llu).\n",
1189 journal_fail_superblock(journal);
1193 journal->j_first = first;
1194 journal->j_last = last;
1196 journal->j_head = first;
1197 journal->j_tail = first;
1198 journal->j_free = last - first;
1200 journal->j_tail_sequence = journal->j_transaction_sequence;
1201 journal->j_commit_sequence = journal->j_transaction_sequence - 1;
1202 journal->j_commit_request = journal->j_commit_sequence;
1204 journal->j_max_transaction_buffers = journal->j_maxlen / 4;
1207 * As a special case, if the on-disk copy is already marked as needing
1208 * no recovery (s_start == 0), then we can safely defer the superblock
1209 * update until the next commit by setting JBD2_FLUSHED. This avoids
1210 * attempting a write to a potential-readonly device.
1212 if (sb->s_start == 0) {
1213 jbd_debug(1, "JBD2: Skipping superblock update on recovered sb "
1214 "(start %ld, seq %d, errno %d)\n",
1215 journal->j_tail, journal->j_tail_sequence,
1217 journal->j_flags |= JBD2_FLUSHED;
1219 /* Lock here to make assertions happy... */
1220 mutex_lock(&journal->j_checkpoint_mutex);
1222 * Update log tail information. We use WRITE_FUA since new
1223 * transaction will start reusing journal space and so we
1224 * must make sure information about current log tail is on
1227 jbd2_journal_update_sb_log_tail(journal,
1228 journal->j_tail_sequence,
1231 mutex_unlock(&journal->j_checkpoint_mutex);
1233 return jbd2_journal_start_thread(journal);
1236 static void jbd2_write_superblock(journal_t *journal, int write_op)
1238 struct buffer_head *bh = journal->j_sb_buffer;
1241 trace_jbd2_write_superblock(journal, write_op);
1242 if (!(journal->j_flags & JBD2_BARRIER))
1243 write_op &= ~(REQ_FUA | REQ_FLUSH);
1245 if (buffer_write_io_error(bh)) {
1247 * Oh, dear. A previous attempt to write the journal
1248 * superblock failed. This could happen because the
1249 * USB device was yanked out. Or it could happen to
1250 * be a transient write error and maybe the block will
1251 * be remapped. Nothing we can do but to retry the
1252 * write and hope for the best.
1254 printk(KERN_ERR "JBD2: previous I/O error detected "
1255 "for journal superblock update for %s.\n",
1256 journal->j_devname);
1257 clear_buffer_write_io_error(bh);
1258 set_buffer_uptodate(bh);
1261 bh->b_end_io = end_buffer_write_sync;
1262 ret = submit_bh(write_op, bh);
1264 if (buffer_write_io_error(bh)) {
1265 clear_buffer_write_io_error(bh);
1266 set_buffer_uptodate(bh);
1270 printk(KERN_ERR "JBD2: Error %d detected when updating "
1271 "journal superblock for %s.\n", ret,
1272 journal->j_devname);
1277 * jbd2_journal_update_sb_log_tail() - Update log tail in journal sb on disk.
1278 * @journal: The journal to update.
1279 * @tail_tid: TID of the new transaction at the tail of the log
1280 * @tail_block: The first block of the transaction at the tail of the log
1281 * @write_op: With which operation should we write the journal sb
1283 * Update a journal's superblock information about log tail and write it to
1284 * disk, waiting for the IO to complete.
1286 void jbd2_journal_update_sb_log_tail(journal_t *journal, tid_t tail_tid,
1287 unsigned long tail_block, int write_op)
1289 journal_superblock_t *sb = journal->j_superblock;
1291 BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
1292 jbd_debug(1, "JBD2: updating superblock (start %lu, seq %u)\n",
1293 tail_block, tail_tid);
1295 sb->s_sequence = cpu_to_be32(tail_tid);
1296 sb->s_start = cpu_to_be32(tail_block);
1298 jbd2_write_superblock(journal, write_op);
1300 /* Log is no longer empty */
1301 write_lock(&journal->j_state_lock);
1302 WARN_ON(!sb->s_sequence);
1303 journal->j_flags &= ~JBD2_FLUSHED;
1304 write_unlock(&journal->j_state_lock);
1308 * jbd2_mark_journal_empty() - Mark on disk journal as empty.
1309 * @journal: The journal to update.
1311 * Update a journal's dynamic superblock fields to show that journal is empty.
1312 * Write updated superblock to disk waiting for IO to complete.
1314 static void jbd2_mark_journal_empty(journal_t *journal)
1316 journal_superblock_t *sb = journal->j_superblock;
1318 BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
1319 read_lock(&journal->j_state_lock);
1320 jbd_debug(1, "JBD2: Marking journal as empty (seq %d)\n",
1321 journal->j_tail_sequence);
1323 sb->s_sequence = cpu_to_be32(journal->j_tail_sequence);
1324 sb->s_start = cpu_to_be32(0);
1325 read_unlock(&journal->j_state_lock);
1327 jbd2_write_superblock(journal, WRITE_FUA);
1329 /* Log is no longer empty */
1330 write_lock(&journal->j_state_lock);
1331 journal->j_flags |= JBD2_FLUSHED;
1332 write_unlock(&journal->j_state_lock);
1337 * jbd2_journal_update_sb_errno() - Update error in the journal.
1338 * @journal: The journal to update.
1340 * Update a journal's errno. Write updated superblock to disk waiting for IO
1343 static void jbd2_journal_update_sb_errno(journal_t *journal)
1345 journal_superblock_t *sb = journal->j_superblock;
1347 read_lock(&journal->j_state_lock);
1348 jbd_debug(1, "JBD2: updating superblock error (errno %d)\n",
1350 sb->s_errno = cpu_to_be32(journal->j_errno);
1351 read_unlock(&journal->j_state_lock);
1353 jbd2_write_superblock(journal, WRITE_SYNC);
1357 * Read the superblock for a given journal, performing initial
1358 * validation of the format.
1360 static int journal_get_superblock(journal_t *journal)
1362 struct buffer_head *bh;
1363 journal_superblock_t *sb;
1366 bh = journal->j_sb_buffer;
1368 J_ASSERT(bh != NULL);
1369 if (!buffer_uptodate(bh)) {
1370 ll_rw_block(READ, 1, &bh);
1372 if (!buffer_uptodate(bh)) {
1374 "JBD2: IO error reading journal superblock\n");
1379 sb = journal->j_superblock;
1383 if (sb->s_header.h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER) ||
1384 sb->s_blocksize != cpu_to_be32(journal->j_blocksize)) {
1385 printk(KERN_WARNING "JBD2: no valid journal superblock found\n");
1389 switch(be32_to_cpu(sb->s_header.h_blocktype)) {
1390 case JBD2_SUPERBLOCK_V1:
1391 journal->j_format_version = 1;
1393 case JBD2_SUPERBLOCK_V2:
1394 journal->j_format_version = 2;
1397 printk(KERN_WARNING "JBD2: unrecognised superblock format ID\n");
1401 if (be32_to_cpu(sb->s_maxlen) < journal->j_maxlen)
1402 journal->j_maxlen = be32_to_cpu(sb->s_maxlen);
1403 else if (be32_to_cpu(sb->s_maxlen) > journal->j_maxlen) {
1404 printk(KERN_WARNING "JBD2: journal file too short\n");
1408 if (be32_to_cpu(sb->s_first) == 0 ||
1409 be32_to_cpu(sb->s_first) >= journal->j_maxlen) {
1411 "JBD2: Invalid start block of journal: %u\n",
1412 be32_to_cpu(sb->s_first));
1419 journal_fail_superblock(journal);
1424 * Load the on-disk journal superblock and read the key fields into the
1428 static int load_superblock(journal_t *journal)
1431 journal_superblock_t *sb;
1433 err = journal_get_superblock(journal);
1437 sb = journal->j_superblock;
1439 journal->j_tail_sequence = be32_to_cpu(sb->s_sequence);
1440 journal->j_tail = be32_to_cpu(sb->s_start);
1441 journal->j_first = be32_to_cpu(sb->s_first);
1442 journal->j_last = be32_to_cpu(sb->s_maxlen);
1443 journal->j_errno = be32_to_cpu(sb->s_errno);
1450 * int jbd2_journal_load() - Read journal from disk.
1451 * @journal: Journal to act on.
1453 * Given a journal_t structure which tells us which disk blocks contain
1454 * a journal, read the journal from disk to initialise the in-memory
1457 int jbd2_journal_load(journal_t *journal)
1460 journal_superblock_t *sb;
1462 err = load_superblock(journal);
1466 sb = journal->j_superblock;
1467 /* If this is a V2 superblock, then we have to check the
1468 * features flags on it. */
1470 if (journal->j_format_version >= 2) {
1471 if ((sb->s_feature_ro_compat &
1472 ~cpu_to_be32(JBD2_KNOWN_ROCOMPAT_FEATURES)) ||
1473 (sb->s_feature_incompat &
1474 ~cpu_to_be32(JBD2_KNOWN_INCOMPAT_FEATURES))) {
1476 "JBD2: Unrecognised features on journal\n");
1482 * Create a slab for this blocksize
1484 err = jbd2_journal_create_slab(be32_to_cpu(sb->s_blocksize));
1488 /* Let the recovery code check whether it needs to recover any
1489 * data from the journal. */
1490 if (jbd2_journal_recover(journal))
1491 goto recovery_error;
1493 if (journal->j_failed_commit) {
1494 printk(KERN_ERR "JBD2: journal transaction %u on %s "
1495 "is corrupt.\n", journal->j_failed_commit,
1496 journal->j_devname);
1500 /* OK, we've finished with the dynamic journal bits:
1501 * reinitialise the dynamic contents of the superblock in memory
1502 * and reset them on disk. */
1503 if (journal_reset(journal))
1504 goto recovery_error;
1506 journal->j_flags &= ~JBD2_ABORT;
1507 journal->j_flags |= JBD2_LOADED;
1511 printk(KERN_WARNING "JBD2: recovery failed\n");
1516 * void jbd2_journal_destroy() - Release a journal_t structure.
1517 * @journal: Journal to act on.
1519 * Release a journal_t structure once it is no longer in use by the
1521 * Return <0 if we couldn't clean up the journal.
1523 int jbd2_journal_destroy(journal_t *journal)
1527 /* Wait for the commit thread to wake up and die. */
1528 journal_kill_thread(journal);
1530 /* Force a final log commit */
1531 if (journal->j_running_transaction)
1532 jbd2_journal_commit_transaction(journal);
1534 /* Force any old transactions to disk */
1536 /* Totally anal locking here... */
1537 spin_lock(&journal->j_list_lock);
1538 while (journal->j_checkpoint_transactions != NULL) {
1539 spin_unlock(&journal->j_list_lock);
1540 mutex_lock(&journal->j_checkpoint_mutex);
1541 jbd2_log_do_checkpoint(journal);
1542 mutex_unlock(&journal->j_checkpoint_mutex);
1543 spin_lock(&journal->j_list_lock);
1546 J_ASSERT(journal->j_running_transaction == NULL);
1547 J_ASSERT(journal->j_committing_transaction == NULL);
1548 J_ASSERT(journal->j_checkpoint_transactions == NULL);
1549 spin_unlock(&journal->j_list_lock);
1551 if (journal->j_sb_buffer) {
1552 if (!is_journal_aborted(journal)) {
1553 mutex_lock(&journal->j_checkpoint_mutex);
1554 jbd2_mark_journal_empty(journal);
1555 mutex_unlock(&journal->j_checkpoint_mutex);
1558 brelse(journal->j_sb_buffer);
1561 if (journal->j_proc_entry)
1562 jbd2_stats_proc_exit(journal);
1563 if (journal->j_inode)
1564 iput(journal->j_inode);
1565 if (journal->j_revoke)
1566 jbd2_journal_destroy_revoke(journal);
1567 kfree(journal->j_wbuf);
1575 *int jbd2_journal_check_used_features () - Check if features specified are used.
1576 * @journal: Journal to check.
1577 * @compat: bitmask of compatible features
1578 * @ro: bitmask of features that force read-only mount
1579 * @incompat: bitmask of incompatible features
1581 * Check whether the journal uses all of a given set of
1582 * features. Return true (non-zero) if it does.
1585 int jbd2_journal_check_used_features (journal_t *journal, unsigned long compat,
1586 unsigned long ro, unsigned long incompat)
1588 journal_superblock_t *sb;
1590 if (!compat && !ro && !incompat)
1592 /* Load journal superblock if it is not loaded yet. */
1593 if (journal->j_format_version == 0 &&
1594 journal_get_superblock(journal) != 0)
1596 if (journal->j_format_version == 1)
1599 sb = journal->j_superblock;
1601 if (((be32_to_cpu(sb->s_feature_compat) & compat) == compat) &&
1602 ((be32_to_cpu(sb->s_feature_ro_compat) & ro) == ro) &&
1603 ((be32_to_cpu(sb->s_feature_incompat) & incompat) == incompat))
1610 * int jbd2_journal_check_available_features() - Check feature set in journalling layer
1611 * @journal: Journal to check.
1612 * @compat: bitmask of compatible features
1613 * @ro: bitmask of features that force read-only mount
1614 * @incompat: bitmask of incompatible features
1616 * Check whether the journaling code supports the use of
1617 * all of a given set of features on this journal. Return true
1618 * (non-zero) if it can. */
1620 int jbd2_journal_check_available_features (journal_t *journal, unsigned long compat,
1621 unsigned long ro, unsigned long incompat)
1623 if (!compat && !ro && !incompat)
1626 /* We can support any known requested features iff the
1627 * superblock is in version 2. Otherwise we fail to support any
1628 * extended sb features. */
1630 if (journal->j_format_version != 2)
1633 if ((compat & JBD2_KNOWN_COMPAT_FEATURES) == compat &&
1634 (ro & JBD2_KNOWN_ROCOMPAT_FEATURES) == ro &&
1635 (incompat & JBD2_KNOWN_INCOMPAT_FEATURES) == incompat)
1642 * int jbd2_journal_set_features () - Mark a given journal feature in the superblock
1643 * @journal: Journal to act on.
1644 * @compat: bitmask of compatible features
1645 * @ro: bitmask of features that force read-only mount
1646 * @incompat: bitmask of incompatible features
1648 * Mark a given journal feature as present on the
1649 * superblock. Returns true if the requested features could be set.
1653 int jbd2_journal_set_features (journal_t *journal, unsigned long compat,
1654 unsigned long ro, unsigned long incompat)
1656 journal_superblock_t *sb;
1658 if (jbd2_journal_check_used_features(journal, compat, ro, incompat))
1661 if (!jbd2_journal_check_available_features(journal, compat, ro, incompat))
1664 jbd_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n",
1665 compat, ro, incompat);
1667 sb = journal->j_superblock;
1669 sb->s_feature_compat |= cpu_to_be32(compat);
1670 sb->s_feature_ro_compat |= cpu_to_be32(ro);
1671 sb->s_feature_incompat |= cpu_to_be32(incompat);
1677 * jbd2_journal_clear_features () - Clear a given journal feature in the
1679 * @journal: Journal to act on.
1680 * @compat: bitmask of compatible features
1681 * @ro: bitmask of features that force read-only mount
1682 * @incompat: bitmask of incompatible features
1684 * Clear a given journal feature as present on the
1687 void jbd2_journal_clear_features(journal_t *journal, unsigned long compat,
1688 unsigned long ro, unsigned long incompat)
1690 journal_superblock_t *sb;
1692 jbd_debug(1, "Clear features 0x%lx/0x%lx/0x%lx\n",
1693 compat, ro, incompat);
1695 sb = journal->j_superblock;
1697 sb->s_feature_compat &= ~cpu_to_be32(compat);
1698 sb->s_feature_ro_compat &= ~cpu_to_be32(ro);
1699 sb->s_feature_incompat &= ~cpu_to_be32(incompat);
1701 EXPORT_SYMBOL(jbd2_journal_clear_features);
1704 * int jbd2_journal_flush () - Flush journal
1705 * @journal: Journal to act on.
1707 * Flush all data for a given journal to disk and empty the journal.
1708 * Filesystems can use this when remounting readonly to ensure that
1709 * recovery does not need to happen on remount.
1712 int jbd2_journal_flush(journal_t *journal)
1715 transaction_t *transaction = NULL;
1717 write_lock(&journal->j_state_lock);
1719 /* Force everything buffered to the log... */
1720 if (journal->j_running_transaction) {
1721 transaction = journal->j_running_transaction;
1722 __jbd2_log_start_commit(journal, transaction->t_tid);
1723 } else if (journal->j_committing_transaction)
1724 transaction = journal->j_committing_transaction;
1726 /* Wait for the log commit to complete... */
1728 tid_t tid = transaction->t_tid;
1730 write_unlock(&journal->j_state_lock);
1731 jbd2_log_wait_commit(journal, tid);
1733 write_unlock(&journal->j_state_lock);
1736 /* ...and flush everything in the log out to disk. */
1737 spin_lock(&journal->j_list_lock);
1738 while (!err && journal->j_checkpoint_transactions != NULL) {
1739 spin_unlock(&journal->j_list_lock);
1740 mutex_lock(&journal->j_checkpoint_mutex);
1741 err = jbd2_log_do_checkpoint(journal);
1742 mutex_unlock(&journal->j_checkpoint_mutex);
1743 spin_lock(&journal->j_list_lock);
1745 spin_unlock(&journal->j_list_lock);
1747 if (is_journal_aborted(journal))
1750 mutex_lock(&journal->j_checkpoint_mutex);
1751 jbd2_cleanup_journal_tail(journal);
1753 /* Finally, mark the journal as really needing no recovery.
1754 * This sets s_start==0 in the underlying superblock, which is
1755 * the magic code for a fully-recovered superblock. Any future
1756 * commits of data to the journal will restore the current
1758 jbd2_mark_journal_empty(journal);
1759 mutex_unlock(&journal->j_checkpoint_mutex);
1760 write_lock(&journal->j_state_lock);
1761 J_ASSERT(!journal->j_running_transaction);
1762 J_ASSERT(!journal->j_committing_transaction);
1763 J_ASSERT(!journal->j_checkpoint_transactions);
1764 J_ASSERT(journal->j_head == journal->j_tail);
1765 J_ASSERT(journal->j_tail_sequence == journal->j_transaction_sequence);
1766 write_unlock(&journal->j_state_lock);
1771 * int jbd2_journal_wipe() - Wipe journal contents
1772 * @journal: Journal to act on.
1773 * @write: flag (see below)
1775 * Wipe out all of the contents of a journal, safely. This will produce
1776 * a warning if the journal contains any valid recovery information.
1777 * Must be called between journal_init_*() and jbd2_journal_load().
1779 * If 'write' is non-zero, then we wipe out the journal on disk; otherwise
1780 * we merely suppress recovery.
1783 int jbd2_journal_wipe(journal_t *journal, int write)
1787 J_ASSERT (!(journal->j_flags & JBD2_LOADED));
1789 err = load_superblock(journal);
1793 if (!journal->j_tail)
1796 printk(KERN_WARNING "JBD2: %s recovery information on journal\n",
1797 write ? "Clearing" : "Ignoring");
1799 err = jbd2_journal_skip_recovery(journal);
1801 /* Lock to make assertions happy... */
1802 mutex_lock(&journal->j_checkpoint_mutex);
1803 jbd2_mark_journal_empty(journal);
1804 mutex_unlock(&journal->j_checkpoint_mutex);
1812 * Journal abort has very specific semantics, which we describe
1813 * for journal abort.
1815 * Two internal functions, which provide abort to the jbd layer
1820 * Quick version for internal journal use (doesn't lock the journal).
1821 * Aborts hard --- we mark the abort as occurred, but do _nothing_ else,
1822 * and don't attempt to make any other journal updates.
1824 void __jbd2_journal_abort_hard(journal_t *journal)
1826 transaction_t *transaction;
1828 if (journal->j_flags & JBD2_ABORT)
1831 printk(KERN_ERR "Aborting journal on device %s.\n",
1832 journal->j_devname);
1834 write_lock(&journal->j_state_lock);
1835 journal->j_flags |= JBD2_ABORT;
1836 transaction = journal->j_running_transaction;
1838 __jbd2_log_start_commit(journal, transaction->t_tid);
1839 write_unlock(&journal->j_state_lock);
1842 /* Soft abort: record the abort error status in the journal superblock,
1843 * but don't do any other IO. */
1844 static void __journal_abort_soft (journal_t *journal, int errno)
1846 if (journal->j_flags & JBD2_ABORT)
1849 if (!journal->j_errno)
1850 journal->j_errno = errno;
1852 __jbd2_journal_abort_hard(journal);
1855 jbd2_journal_update_sb_errno(journal);
1859 * void jbd2_journal_abort () - Shutdown the journal immediately.
1860 * @journal: the journal to shutdown.
1861 * @errno: an error number to record in the journal indicating
1862 * the reason for the shutdown.
1864 * Perform a complete, immediate shutdown of the ENTIRE
1865 * journal (not of a single transaction). This operation cannot be
1866 * undone without closing and reopening the journal.
1868 * The jbd2_journal_abort function is intended to support higher level error
1869 * recovery mechanisms such as the ext2/ext3 remount-readonly error
1872 * Journal abort has very specific semantics. Any existing dirty,
1873 * unjournaled buffers in the main filesystem will still be written to
1874 * disk by bdflush, but the journaling mechanism will be suspended
1875 * immediately and no further transaction commits will be honoured.
1877 * Any dirty, journaled buffers will be written back to disk without
1878 * hitting the journal. Atomicity cannot be guaranteed on an aborted
1879 * filesystem, but we _do_ attempt to leave as much data as possible
1880 * behind for fsck to use for cleanup.
1882 * Any attempt to get a new transaction handle on a journal which is in
1883 * ABORT state will just result in an -EROFS error return. A
1884 * jbd2_journal_stop on an existing handle will return -EIO if we have
1885 * entered abort state during the update.
1887 * Recursive transactions are not disturbed by journal abort until the
1888 * final jbd2_journal_stop, which will receive the -EIO error.
1890 * Finally, the jbd2_journal_abort call allows the caller to supply an errno
1891 * which will be recorded (if possible) in the journal superblock. This
1892 * allows a client to record failure conditions in the middle of a
1893 * transaction without having to complete the transaction to record the
1894 * failure to disk. ext3_error, for example, now uses this
1897 * Errors which originate from within the journaling layer will NOT
1898 * supply an errno; a null errno implies that absolutely no further
1899 * writes are done to the journal (unless there are any already in
1904 void jbd2_journal_abort(journal_t *journal, int errno)
1906 __journal_abort_soft(journal, errno);
1910 * int jbd2_journal_errno () - returns the journal's error state.
1911 * @journal: journal to examine.
1913 * This is the errno number set with jbd2_journal_abort(), the last
1914 * time the journal was mounted - if the journal was stopped
1915 * without calling abort this will be 0.
1917 * If the journal has been aborted on this mount time -EROFS will
1920 int jbd2_journal_errno(journal_t *journal)
1924 read_lock(&journal->j_state_lock);
1925 if (journal->j_flags & JBD2_ABORT)
1928 err = journal->j_errno;
1929 read_unlock(&journal->j_state_lock);
1934 * int jbd2_journal_clear_err () - clears the journal's error state
1935 * @journal: journal to act on.
1937 * An error must be cleared or acked to take a FS out of readonly
1940 int jbd2_journal_clear_err(journal_t *journal)
1944 write_lock(&journal->j_state_lock);
1945 if (journal->j_flags & JBD2_ABORT)
1948 journal->j_errno = 0;
1949 write_unlock(&journal->j_state_lock);
1954 * void jbd2_journal_ack_err() - Ack journal err.
1955 * @journal: journal to act on.
1957 * An error must be cleared or acked to take a FS out of readonly
1960 void jbd2_journal_ack_err(journal_t *journal)
1962 write_lock(&journal->j_state_lock);
1963 if (journal->j_errno)
1964 journal->j_flags |= JBD2_ACK_ERR;
1965 write_unlock(&journal->j_state_lock);
1968 int jbd2_journal_blocks_per_page(struct inode *inode)
1970 return 1 << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
1974 * helper functions to deal with 32 or 64bit block numbers.
1976 size_t journal_tag_bytes(journal_t *journal)
1978 if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT))
1979 return JBD2_TAG_SIZE64;
1981 return JBD2_TAG_SIZE32;
1985 * JBD memory management
1987 * These functions are used to allocate block-sized chunks of memory
1988 * used for making copies of buffer_head data. Very often it will be
1989 * page-sized chunks of data, but sometimes it will be in
1990 * sub-page-size chunks. (For example, 16k pages on Power systems
1991 * with a 4k block file system.) For blocks smaller than a page, we
1992 * use a SLAB allocator. There are slab caches for each block size,
1993 * which are allocated at mount time, if necessary, and we only free
1994 * (all of) the slab caches when/if the jbd2 module is unloaded. For
1995 * this reason we don't need to a mutex to protect access to
1996 * jbd2_slab[] allocating or releasing memory; only in
1997 * jbd2_journal_create_slab().
1999 #define JBD2_MAX_SLABS 8
2000 static struct kmem_cache *jbd2_slab[JBD2_MAX_SLABS];
2002 static const char *jbd2_slab_names[JBD2_MAX_SLABS] = {
2003 "jbd2_1k", "jbd2_2k", "jbd2_4k", "jbd2_8k",
2004 "jbd2_16k", "jbd2_32k", "jbd2_64k", "jbd2_128k"
2008 static void jbd2_journal_destroy_slabs(void)
2012 for (i = 0; i < JBD2_MAX_SLABS; i++) {
2014 kmem_cache_destroy(jbd2_slab[i]);
2015 jbd2_slab[i] = NULL;
2019 static int jbd2_journal_create_slab(size_t size)
2021 static DEFINE_MUTEX(jbd2_slab_create_mutex);
2022 int i = order_base_2(size) - 10;
2025 if (size == PAGE_SIZE)
2028 if (i >= JBD2_MAX_SLABS)
2031 if (unlikely(i < 0))
2033 mutex_lock(&jbd2_slab_create_mutex);
2035 mutex_unlock(&jbd2_slab_create_mutex);
2036 return 0; /* Already created */
2039 slab_size = 1 << (i+10);
2040 jbd2_slab[i] = kmem_cache_create(jbd2_slab_names[i], slab_size,
2041 slab_size, 0, NULL);
2042 mutex_unlock(&jbd2_slab_create_mutex);
2043 if (!jbd2_slab[i]) {
2044 printk(KERN_EMERG "JBD2: no memory for jbd2_slab cache\n");
2050 static struct kmem_cache *get_slab(size_t size)
2052 int i = order_base_2(size) - 10;
2054 BUG_ON(i >= JBD2_MAX_SLABS);
2055 if (unlikely(i < 0))
2057 BUG_ON(jbd2_slab[i] == NULL);
2058 return jbd2_slab[i];
2061 void *jbd2_alloc(size_t size, gfp_t flags)
2065 BUG_ON(size & (size-1)); /* Must be a power of 2 */
2067 flags |= __GFP_REPEAT;
2068 if (size == PAGE_SIZE)
2069 ptr = (void *)__get_free_pages(flags, 0);
2070 else if (size > PAGE_SIZE) {
2071 int order = get_order(size);
2074 ptr = (void *)__get_free_pages(flags, order);
2076 ptr = vmalloc(size);
2078 ptr = kmem_cache_alloc(get_slab(size), flags);
2080 /* Check alignment; SLUB has gotten this wrong in the past,
2081 * and this can lead to user data corruption! */
2082 BUG_ON(((unsigned long) ptr) & (size-1));
2087 void jbd2_free(void *ptr, size_t size)
2089 if (size == PAGE_SIZE) {
2090 free_pages((unsigned long)ptr, 0);
2093 if (size > PAGE_SIZE) {
2094 int order = get_order(size);
2097 free_pages((unsigned long)ptr, order);
2102 kmem_cache_free(get_slab(size), ptr);
2106 * Journal_head storage management
2108 static struct kmem_cache *jbd2_journal_head_cache;
2109 #ifdef CONFIG_JBD2_DEBUG
2110 static atomic_t nr_journal_heads = ATOMIC_INIT(0);
2113 static int jbd2_journal_init_journal_head_cache(void)
2117 J_ASSERT(jbd2_journal_head_cache == NULL);
2118 jbd2_journal_head_cache = kmem_cache_create("jbd2_journal_head",
2119 sizeof(struct journal_head),
2121 SLAB_TEMPORARY, /* flags */
2124 if (!jbd2_journal_head_cache) {
2126 printk(KERN_EMERG "JBD2: no memory for journal_head cache\n");
2131 static void jbd2_journal_destroy_journal_head_cache(void)
2133 if (jbd2_journal_head_cache) {
2134 kmem_cache_destroy(jbd2_journal_head_cache);
2135 jbd2_journal_head_cache = NULL;
2140 * journal_head splicing and dicing
2142 static struct journal_head *journal_alloc_journal_head(void)
2144 struct journal_head *ret;
2146 #ifdef CONFIG_JBD2_DEBUG
2147 atomic_inc(&nr_journal_heads);
2149 ret = kmem_cache_alloc(jbd2_journal_head_cache, GFP_NOFS);
2151 jbd_debug(1, "out of memory for journal_head\n");
2152 pr_notice_ratelimited("ENOMEM in %s, retrying.\n", __func__);
2155 ret = kmem_cache_alloc(jbd2_journal_head_cache, GFP_NOFS);
2161 static void journal_free_journal_head(struct journal_head *jh)
2163 #ifdef CONFIG_JBD2_DEBUG
2164 atomic_dec(&nr_journal_heads);
2165 memset(jh, JBD2_POISON_FREE, sizeof(*jh));
2167 kmem_cache_free(jbd2_journal_head_cache, jh);
2171 * A journal_head is attached to a buffer_head whenever JBD has an
2172 * interest in the buffer.
2174 * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit
2175 * is set. This bit is tested in core kernel code where we need to take
2176 * JBD-specific actions. Testing the zeroness of ->b_private is not reliable
2179 * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one.
2181 * When a buffer has its BH_JBD bit set it is immune from being released by
2182 * core kernel code, mainly via ->b_count.
2184 * A journal_head is detached from its buffer_head when the journal_head's
2185 * b_jcount reaches zero. Running transaction (b_transaction) and checkpoint
2186 * transaction (b_cp_transaction) hold their references to b_jcount.
2188 * Various places in the kernel want to attach a journal_head to a buffer_head
2189 * _before_ attaching the journal_head to a transaction. To protect the
2190 * journal_head in this situation, jbd2_journal_add_journal_head elevates the
2191 * journal_head's b_jcount refcount by one. The caller must call
2192 * jbd2_journal_put_journal_head() to undo this.
2194 * So the typical usage would be:
2196 * (Attach a journal_head if needed. Increments b_jcount)
2197 * struct journal_head *jh = jbd2_journal_add_journal_head(bh);
2199 * (Get another reference for transaction)
2200 * jbd2_journal_grab_journal_head(bh);
2201 * jh->b_transaction = xxx;
2202 * (Put original reference)
2203 * jbd2_journal_put_journal_head(jh);
2207 * Give a buffer_head a journal_head.
2211 struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh)
2213 struct journal_head *jh;
2214 struct journal_head *new_jh = NULL;
2217 if (!buffer_jbd(bh)) {
2218 new_jh = journal_alloc_journal_head();
2219 memset(new_jh, 0, sizeof(*new_jh));
2222 jbd_lock_bh_journal_head(bh);
2223 if (buffer_jbd(bh)) {
2227 (atomic_read(&bh->b_count) > 0) ||
2228 (bh->b_page && bh->b_page->mapping));
2231 jbd_unlock_bh_journal_head(bh);
2236 new_jh = NULL; /* We consumed it */
2241 BUFFER_TRACE(bh, "added journal_head");
2244 jbd_unlock_bh_journal_head(bh);
2246 journal_free_journal_head(new_jh);
2247 return bh->b_private;
2251 * Grab a ref against this buffer_head's journal_head. If it ended up not
2252 * having a journal_head, return NULL
2254 struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh)
2256 struct journal_head *jh = NULL;
2258 jbd_lock_bh_journal_head(bh);
2259 if (buffer_jbd(bh)) {
2263 jbd_unlock_bh_journal_head(bh);
2267 static void __journal_remove_journal_head(struct buffer_head *bh)
2269 struct journal_head *jh = bh2jh(bh);
2271 J_ASSERT_JH(jh, jh->b_jcount >= 0);
2272 J_ASSERT_JH(jh, jh->b_transaction == NULL);
2273 J_ASSERT_JH(jh, jh->b_next_transaction == NULL);
2274 J_ASSERT_JH(jh, jh->b_cp_transaction == NULL);
2275 J_ASSERT_JH(jh, jh->b_jlist == BJ_None);
2276 J_ASSERT_BH(bh, buffer_jbd(bh));
2277 J_ASSERT_BH(bh, jh2bh(jh) == bh);
2278 BUFFER_TRACE(bh, "remove journal_head");
2279 if (jh->b_frozen_data) {
2280 printk(KERN_WARNING "%s: freeing b_frozen_data\n", __func__);
2281 jbd2_free(jh->b_frozen_data, bh->b_size);
2283 if (jh->b_committed_data) {
2284 printk(KERN_WARNING "%s: freeing b_committed_data\n", __func__);
2285 jbd2_free(jh->b_committed_data, bh->b_size);
2287 bh->b_private = NULL;
2288 jh->b_bh = NULL; /* debug, really */
2289 clear_buffer_jbd(bh);
2290 journal_free_journal_head(jh);
2294 * Drop a reference on the passed journal_head. If it fell to zero then
2295 * release the journal_head from the buffer_head.
2297 void jbd2_journal_put_journal_head(struct journal_head *jh)
2299 struct buffer_head *bh = jh2bh(jh);
2301 jbd_lock_bh_journal_head(bh);
2302 J_ASSERT_JH(jh, jh->b_jcount > 0);
2304 if (!jh->b_jcount) {
2305 __journal_remove_journal_head(bh);
2306 jbd_unlock_bh_journal_head(bh);
2309 jbd_unlock_bh_journal_head(bh);
2313 * Initialize jbd inode head
2315 void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode)
2317 jinode->i_transaction = NULL;
2318 jinode->i_next_transaction = NULL;
2319 jinode->i_vfs_inode = inode;
2320 jinode->i_flags = 0;
2321 INIT_LIST_HEAD(&jinode->i_list);
2325 * Function to be called before we start removing inode from memory (i.e.,
2326 * clear_inode() is a fine place to be called from). It removes inode from
2327 * transaction's lists.
2329 void jbd2_journal_release_jbd_inode(journal_t *journal,
2330 struct jbd2_inode *jinode)
2335 spin_lock(&journal->j_list_lock);
2336 /* Is commit writing out inode - we have to wait */
2337 if (test_bit(__JI_COMMIT_RUNNING, &jinode->i_flags)) {
2338 wait_queue_head_t *wq;
2339 DEFINE_WAIT_BIT(wait, &jinode->i_flags, __JI_COMMIT_RUNNING);
2340 wq = bit_waitqueue(&jinode->i_flags, __JI_COMMIT_RUNNING);
2341 prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE);
2342 spin_unlock(&journal->j_list_lock);
2344 finish_wait(wq, &wait.wait);
2348 if (jinode->i_transaction) {
2349 list_del(&jinode->i_list);
2350 jinode->i_transaction = NULL;
2352 spin_unlock(&journal->j_list_lock);
2358 #ifdef CONFIG_JBD2_DEBUG
2359 u8 jbd2_journal_enable_debug __read_mostly;
2360 EXPORT_SYMBOL(jbd2_journal_enable_debug);
2362 #define JBD2_DEBUG_NAME "jbd2-debug"
2364 static struct dentry *jbd2_debugfs_dir;
2365 static struct dentry *jbd2_debug;
2367 static void __init jbd2_create_debugfs_entry(void)
2369 jbd2_debugfs_dir = debugfs_create_dir("jbd2", NULL);
2370 if (jbd2_debugfs_dir)
2371 jbd2_debug = debugfs_create_u8(JBD2_DEBUG_NAME,
2374 &jbd2_journal_enable_debug);
2377 static void __exit jbd2_remove_debugfs_entry(void)
2379 debugfs_remove(jbd2_debug);
2380 debugfs_remove(jbd2_debugfs_dir);
2385 static void __init jbd2_create_debugfs_entry(void)
2389 static void __exit jbd2_remove_debugfs_entry(void)
2395 #ifdef CONFIG_PROC_FS
2397 #define JBD2_STATS_PROC_NAME "fs/jbd2"
2399 static void __init jbd2_create_jbd_stats_proc_entry(void)
2401 proc_jbd2_stats = proc_mkdir(JBD2_STATS_PROC_NAME, NULL);
2404 static void __exit jbd2_remove_jbd_stats_proc_entry(void)
2406 if (proc_jbd2_stats)
2407 remove_proc_entry(JBD2_STATS_PROC_NAME, NULL);
2412 #define jbd2_create_jbd_stats_proc_entry() do {} while (0)
2413 #define jbd2_remove_jbd_stats_proc_entry() do {} while (0)
2417 struct kmem_cache *jbd2_handle_cache, *jbd2_inode_cache;
2419 static int __init jbd2_journal_init_handle_cache(void)
2421 jbd2_handle_cache = KMEM_CACHE(jbd2_journal_handle, SLAB_TEMPORARY);
2422 if (jbd2_handle_cache == NULL) {
2423 printk(KERN_EMERG "JBD2: failed to create handle cache\n");
2426 jbd2_inode_cache = KMEM_CACHE(jbd2_inode, 0);
2427 if (jbd2_inode_cache == NULL) {
2428 printk(KERN_EMERG "JBD2: failed to create inode cache\n");
2429 kmem_cache_destroy(jbd2_handle_cache);
2435 static void jbd2_journal_destroy_handle_cache(void)
2437 if (jbd2_handle_cache)
2438 kmem_cache_destroy(jbd2_handle_cache);
2439 if (jbd2_inode_cache)
2440 kmem_cache_destroy(jbd2_inode_cache);
2445 * Module startup and shutdown
2448 static int __init journal_init_caches(void)
2452 ret = jbd2_journal_init_revoke_caches();
2454 ret = jbd2_journal_init_journal_head_cache();
2456 ret = jbd2_journal_init_handle_cache();
2458 ret = jbd2_journal_init_transaction_cache();
2462 static void jbd2_journal_destroy_caches(void)
2464 jbd2_journal_destroy_revoke_caches();
2465 jbd2_journal_destroy_journal_head_cache();
2466 jbd2_journal_destroy_handle_cache();
2467 jbd2_journal_destroy_transaction_cache();
2468 jbd2_journal_destroy_slabs();
2471 static int __init journal_init(void)
2475 BUILD_BUG_ON(sizeof(struct journal_superblock_s) != 1024);
2477 ret = journal_init_caches();
2479 jbd2_create_debugfs_entry();
2480 jbd2_create_jbd_stats_proc_entry();
2482 jbd2_journal_destroy_caches();
2487 static void __exit journal_exit(void)
2489 #ifdef CONFIG_JBD2_DEBUG
2490 int n = atomic_read(&nr_journal_heads);
2492 printk(KERN_EMERG "JBD2: leaked %d journal_heads!\n", n);
2494 jbd2_remove_debugfs_entry();
2495 jbd2_remove_jbd_stats_proc_entry();
2496 jbd2_journal_destroy_caches();
2499 MODULE_LICENSE("GPL");
2500 module_init(journal_init);
2501 module_exit(journal_exit);