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>
53 #include <asm/system.h>
55 EXPORT_SYMBOL(jbd2_journal_extend
);
56 EXPORT_SYMBOL(jbd2_journal_stop
);
57 EXPORT_SYMBOL(jbd2_journal_lock_updates
);
58 EXPORT_SYMBOL(jbd2_journal_unlock_updates
);
59 EXPORT_SYMBOL(jbd2_journal_get_write_access
);
60 EXPORT_SYMBOL(jbd2_journal_get_create_access
);
61 EXPORT_SYMBOL(jbd2_journal_get_undo_access
);
62 EXPORT_SYMBOL(jbd2_journal_set_triggers
);
63 EXPORT_SYMBOL(jbd2_journal_dirty_metadata
);
64 EXPORT_SYMBOL(jbd2_journal_release_buffer
);
65 EXPORT_SYMBOL(jbd2_journal_forget
);
67 EXPORT_SYMBOL(journal_sync_buffer
);
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_update_format
);
75 EXPORT_SYMBOL(jbd2_journal_check_used_features
);
76 EXPORT_SYMBOL(jbd2_journal_check_available_features
);
77 EXPORT_SYMBOL(jbd2_journal_set_features
);
78 EXPORT_SYMBOL(jbd2_journal_load
);
79 EXPORT_SYMBOL(jbd2_journal_destroy
);
80 EXPORT_SYMBOL(jbd2_journal_abort
);
81 EXPORT_SYMBOL(jbd2_journal_errno
);
82 EXPORT_SYMBOL(jbd2_journal_ack_err
);
83 EXPORT_SYMBOL(jbd2_journal_clear_err
);
84 EXPORT_SYMBOL(jbd2_log_wait_commit
);
85 EXPORT_SYMBOL(jbd2_log_start_commit
);
86 EXPORT_SYMBOL(jbd2_journal_start_commit
);
87 EXPORT_SYMBOL(jbd2_journal_force_commit_nested
);
88 EXPORT_SYMBOL(jbd2_journal_wipe
);
89 EXPORT_SYMBOL(jbd2_journal_blocks_per_page
);
90 EXPORT_SYMBOL(jbd2_journal_invalidatepage
);
91 EXPORT_SYMBOL(jbd2_journal_try_to_free_buffers
);
92 EXPORT_SYMBOL(jbd2_journal_force_commit
);
93 EXPORT_SYMBOL(jbd2_journal_file_inode
);
94 EXPORT_SYMBOL(jbd2_journal_init_jbd_inode
);
95 EXPORT_SYMBOL(jbd2_journal_release_jbd_inode
);
96 EXPORT_SYMBOL(jbd2_journal_begin_ordered_truncate
);
97 EXPORT_SYMBOL(jbd2_inode_cache
);
99 static int journal_convert_superblock_v1(journal_t
*, journal_superblock_t
*);
100 static void __journal_abort_soft (journal_t
*journal
, int errno
);
101 static int jbd2_journal_create_slab(size_t slab_size
);
104 * Helper function used to manage commit timeouts
107 static void commit_timeout(unsigned long __data
)
109 struct task_struct
* p
= (struct task_struct
*) __data
;
115 * kjournald2: The main thread function used to manage a logging device
118 * This kernel thread is responsible for two things:
120 * 1) COMMIT: Every so often we need to commit the current state of the
121 * filesystem to disk. The journal thread is responsible for writing
122 * all of the metadata buffers to disk.
124 * 2) CHECKPOINT: We cannot reuse a used section of the log file until all
125 * of the data in that part of the log has been rewritten elsewhere on
126 * the disk. Flushing these old buffers to reclaim space in the log is
127 * known as checkpointing, and this thread is responsible for that job.
130 static int kjournald2(void *arg
)
132 journal_t
*journal
= arg
;
133 transaction_t
*transaction
;
136 * Set up an interval timer which can be used to trigger a commit wakeup
137 * after the commit interval expires
139 setup_timer(&journal
->j_commit_timer
, commit_timeout
,
140 (unsigned long)current
);
144 /* Record that the journal thread is running */
145 journal
->j_task
= current
;
146 wake_up(&journal
->j_wait_done_commit
);
149 * And now, wait forever for commit wakeup events.
151 write_lock(&journal
->j_state_lock
);
154 if (journal
->j_flags
& JBD2_UNMOUNT
)
157 jbd_debug(1, "commit_sequence=%d, commit_request=%d\n",
158 journal
->j_commit_sequence
, journal
->j_commit_request
);
160 if (journal
->j_commit_sequence
!= journal
->j_commit_request
) {
161 jbd_debug(1, "OK, requests differ\n");
162 write_unlock(&journal
->j_state_lock
);
163 del_timer_sync(&journal
->j_commit_timer
);
164 jbd2_journal_commit_transaction(journal
);
165 write_lock(&journal
->j_state_lock
);
169 wake_up(&journal
->j_wait_done_commit
);
170 if (freezing(current
)) {
172 * The simpler the better. Flushing journal isn't a
173 * good idea, because that depends on threads that may
174 * be already stopped.
176 jbd_debug(1, "Now suspending kjournald2\n");
177 write_unlock(&journal
->j_state_lock
);
179 write_lock(&journal
->j_state_lock
);
182 * We assume on resume that commits are already there,
186 int should_sleep
= 1;
188 prepare_to_wait(&journal
->j_wait_commit
, &wait
,
190 if (journal
->j_commit_sequence
!= journal
->j_commit_request
)
192 transaction
= journal
->j_running_transaction
;
193 if (transaction
&& time_after_eq(jiffies
,
194 transaction
->t_expires
))
196 if (journal
->j_flags
& JBD2_UNMOUNT
)
199 write_unlock(&journal
->j_state_lock
);
201 write_lock(&journal
->j_state_lock
);
203 finish_wait(&journal
->j_wait_commit
, &wait
);
206 jbd_debug(1, "kjournald2 wakes\n");
209 * Were we woken up by a commit wakeup event?
211 transaction
= journal
->j_running_transaction
;
212 if (transaction
&& time_after_eq(jiffies
, transaction
->t_expires
)) {
213 journal
->j_commit_request
= transaction
->t_tid
;
214 jbd_debug(1, "woke because of timeout\n");
219 write_unlock(&journal
->j_state_lock
);
220 del_timer_sync(&journal
->j_commit_timer
);
221 journal
->j_task
= NULL
;
222 wake_up(&journal
->j_wait_done_commit
);
223 jbd_debug(1, "Journal thread exiting.\n");
227 static int jbd2_journal_start_thread(journal_t
*journal
)
229 struct task_struct
*t
;
231 t
= kthread_run(kjournald2
, journal
, "jbd2/%s",
236 wait_event(journal
->j_wait_done_commit
, journal
->j_task
!= NULL
);
240 static void journal_kill_thread(journal_t
*journal
)
242 write_lock(&journal
->j_state_lock
);
243 journal
->j_flags
|= JBD2_UNMOUNT
;
245 while (journal
->j_task
) {
246 wake_up(&journal
->j_wait_commit
);
247 write_unlock(&journal
->j_state_lock
);
248 wait_event(journal
->j_wait_done_commit
, journal
->j_task
== NULL
);
249 write_lock(&journal
->j_state_lock
);
251 write_unlock(&journal
->j_state_lock
);
255 * jbd2_journal_write_metadata_buffer: write a metadata buffer to the journal.
257 * Writes a metadata buffer to a given disk block. The actual IO is not
258 * performed but a new buffer_head is constructed which labels the data
259 * to be written with the correct destination disk block.
261 * Any magic-number escaping which needs to be done will cause a
262 * copy-out here. If the buffer happens to start with the
263 * JBD2_MAGIC_NUMBER, then we can't write it to the log directly: the
264 * magic number is only written to the log for descripter blocks. In
265 * this case, we copy the data and replace the first word with 0, and we
266 * return a result code which indicates that this buffer needs to be
267 * marked as an escaped buffer in the corresponding log descriptor
268 * block. The missing word can then be restored when the block is read
271 * If the source buffer has already been modified by a new transaction
272 * since we took the last commit snapshot, we use the frozen copy of
273 * that data for IO. If we end up using the existing buffer_head's data
274 * for the write, then we *have* to lock the buffer to prevent anyone
275 * else from using and possibly modifying it while the IO is in
278 * The function returns a pointer to the buffer_heads to be used for IO.
280 * We assume that the journal has already been locked in this function.
287 * Bit 0 set == escape performed on the data
288 * Bit 1 set == buffer copy-out performed (kfree the data after IO)
291 int jbd2_journal_write_metadata_buffer(transaction_t
*transaction
,
292 struct journal_head
*jh_in
,
293 struct journal_head
**jh_out
,
294 unsigned long long blocknr
)
296 int need_copy_out
= 0;
297 int done_copy_out
= 0;
300 struct buffer_head
*new_bh
;
301 struct journal_head
*new_jh
;
302 struct page
*new_page
;
303 unsigned int new_offset
;
304 struct buffer_head
*bh_in
= jh2bh(jh_in
);
305 journal_t
*journal
= transaction
->t_journal
;
308 * The buffer really shouldn't be locked: only the current committing
309 * transaction is allowed to write it, so nobody else is allowed
312 * akpm: except if we're journalling data, and write() output is
313 * also part of a shared mapping, and another thread has
314 * decided to launch a writepage() against this buffer.
316 J_ASSERT_BH(bh_in
, buffer_jbddirty(bh_in
));
319 new_bh
= alloc_buffer_head(GFP_NOFS
);
322 * Failure is not an option, but __GFP_NOFAIL is going
323 * away; so we retry ourselves here.
325 congestion_wait(BLK_RW_ASYNC
, HZ
/50);
329 /* keep subsequent assertions sane */
331 init_buffer(new_bh
, NULL
, NULL
);
332 atomic_set(&new_bh
->b_count
, 1);
333 new_jh
= jbd2_journal_add_journal_head(new_bh
); /* This sleeps */
336 * If a new transaction has already done a buffer copy-out, then
337 * we use that version of the data for the commit.
339 jbd_lock_bh_state(bh_in
);
341 if (jh_in
->b_frozen_data
) {
343 new_page
= virt_to_page(jh_in
->b_frozen_data
);
344 new_offset
= offset_in_page(jh_in
->b_frozen_data
);
346 new_page
= jh2bh(jh_in
)->b_page
;
347 new_offset
= offset_in_page(jh2bh(jh_in
)->b_data
);
350 mapped_data
= kmap_atomic(new_page
);
352 * Fire data frozen trigger if data already wasn't frozen. Do this
353 * before checking for escaping, as the trigger may modify the magic
354 * offset. If a copy-out happens afterwards, it will have the correct
355 * data in the buffer.
358 jbd2_buffer_frozen_trigger(jh_in
, mapped_data
+ new_offset
,
364 if (*((__be32
*)(mapped_data
+ new_offset
)) ==
365 cpu_to_be32(JBD2_MAGIC_NUMBER
)) {
369 kunmap_atomic(mapped_data
);
372 * Do we need to do a data copy?
374 if (need_copy_out
&& !done_copy_out
) {
377 jbd_unlock_bh_state(bh_in
);
378 tmp
= jbd2_alloc(bh_in
->b_size
, GFP_NOFS
);
380 jbd2_journal_put_journal_head(new_jh
);
383 jbd_lock_bh_state(bh_in
);
384 if (jh_in
->b_frozen_data
) {
385 jbd2_free(tmp
, bh_in
->b_size
);
389 jh_in
->b_frozen_data
= tmp
;
390 mapped_data
= kmap_atomic(new_page
);
391 memcpy(tmp
, mapped_data
+ new_offset
, jh2bh(jh_in
)->b_size
);
392 kunmap_atomic(mapped_data
);
394 new_page
= virt_to_page(tmp
);
395 new_offset
= offset_in_page(tmp
);
399 * This isn't strictly necessary, as we're using frozen
400 * data for the escaping, but it keeps consistency with
401 * b_frozen_data usage.
403 jh_in
->b_frozen_triggers
= jh_in
->b_triggers
;
407 * Did we need to do an escaping? Now we've done all the
408 * copying, we can finally do so.
411 mapped_data
= kmap_atomic(new_page
);
412 *((unsigned int *)(mapped_data
+ new_offset
)) = 0;
413 kunmap_atomic(mapped_data
);
416 set_bh_page(new_bh
, new_page
, new_offset
);
417 new_jh
->b_transaction
= NULL
;
418 new_bh
->b_size
= jh2bh(jh_in
)->b_size
;
419 new_bh
->b_bdev
= transaction
->t_journal
->j_dev
;
420 new_bh
->b_blocknr
= blocknr
;
421 set_buffer_mapped(new_bh
);
422 set_buffer_dirty(new_bh
);
427 * The to-be-written buffer needs to get moved to the io queue,
428 * and the original buffer whose contents we are shadowing or
429 * copying is moved to the transaction's shadow queue.
431 JBUFFER_TRACE(jh_in
, "file as BJ_Shadow");
432 spin_lock(&journal
->j_list_lock
);
433 __jbd2_journal_file_buffer(jh_in
, transaction
, BJ_Shadow
);
434 spin_unlock(&journal
->j_list_lock
);
435 jbd_unlock_bh_state(bh_in
);
437 JBUFFER_TRACE(new_jh
, "file as BJ_IO");
438 jbd2_journal_file_buffer(new_jh
, transaction
, BJ_IO
);
440 return do_escape
| (done_copy_out
<< 1);
444 * Allocation code for the journal file. Manage the space left in the
445 * journal, so that we can begin checkpointing when appropriate.
449 * __jbd2_log_space_left: Return the number of free blocks left in the journal.
451 * Called with the journal already locked.
453 * Called under j_state_lock
456 int __jbd2_log_space_left(journal_t
*journal
)
458 int left
= journal
->j_free
;
460 /* assert_spin_locked(&journal->j_state_lock); */
463 * Be pessimistic here about the number of those free blocks which
464 * might be required for log descriptor control blocks.
467 #define MIN_LOG_RESERVED_BLOCKS 32 /* Allow for rounding errors */
469 left
-= MIN_LOG_RESERVED_BLOCKS
;
478 * Called with j_state_lock locked for writing.
479 * Returns true if a transaction commit was started.
481 int __jbd2_log_start_commit(journal_t
*journal
, tid_t target
)
484 * The only transaction we can possibly wait upon is the
485 * currently running transaction (if it exists). Otherwise,
486 * the target tid must be an old one.
488 if (journal
->j_running_transaction
&&
489 journal
->j_running_transaction
->t_tid
== target
) {
491 * We want a new commit: OK, mark the request and wakeup the
492 * commit thread. We do _not_ do the commit ourselves.
495 journal
->j_commit_request
= target
;
496 jbd_debug(1, "JBD2: requesting commit %d/%d\n",
497 journal
->j_commit_request
,
498 journal
->j_commit_sequence
);
499 wake_up(&journal
->j_wait_commit
);
501 } else if (!tid_geq(journal
->j_commit_request
, target
))
502 /* This should never happen, but if it does, preserve
503 the evidence before kjournald goes into a loop and
504 increments j_commit_sequence beyond all recognition. */
505 WARN_ONCE(1, "JBD2: bad log_start_commit: %u %u %u %u\n",
506 journal
->j_commit_request
,
507 journal
->j_commit_sequence
,
508 target
, journal
->j_running_transaction
?
509 journal
->j_running_transaction
->t_tid
: 0);
513 int jbd2_log_start_commit(journal_t
*journal
, tid_t tid
)
517 write_lock(&journal
->j_state_lock
);
518 ret
= __jbd2_log_start_commit(journal
, tid
);
519 write_unlock(&journal
->j_state_lock
);
524 * Force and wait upon a commit if the calling process is not within
525 * transaction. This is used for forcing out undo-protected data which contains
526 * bitmaps, when the fs is running out of space.
528 * We can only force the running transaction if we don't have an active handle;
529 * otherwise, we will deadlock.
531 * Returns true if a transaction was started.
533 int jbd2_journal_force_commit_nested(journal_t
*journal
)
535 transaction_t
*transaction
= NULL
;
537 int need_to_start
= 0;
539 read_lock(&journal
->j_state_lock
);
540 if (journal
->j_running_transaction
&& !current
->journal_info
) {
541 transaction
= journal
->j_running_transaction
;
542 if (!tid_geq(journal
->j_commit_request
, transaction
->t_tid
))
544 } else if (journal
->j_committing_transaction
)
545 transaction
= journal
->j_committing_transaction
;
548 read_unlock(&journal
->j_state_lock
);
549 return 0; /* Nothing to retry */
552 tid
= transaction
->t_tid
;
553 read_unlock(&journal
->j_state_lock
);
555 jbd2_log_start_commit(journal
, tid
);
556 jbd2_log_wait_commit(journal
, tid
);
561 * Start a commit of the current running transaction (if any). Returns true
562 * if a transaction is going to be committed (or is currently already
563 * committing), and fills its tid in at *ptid
565 int jbd2_journal_start_commit(journal_t
*journal
, tid_t
*ptid
)
569 write_lock(&journal
->j_state_lock
);
570 if (journal
->j_running_transaction
) {
571 tid_t tid
= journal
->j_running_transaction
->t_tid
;
573 __jbd2_log_start_commit(journal
, tid
);
574 /* There's a running transaction and we've just made sure
575 * it's commit has been scheduled. */
579 } else if (journal
->j_committing_transaction
) {
581 * If ext3_write_super() recently started a commit, then we
582 * have to wait for completion of that transaction
585 *ptid
= journal
->j_committing_transaction
->t_tid
;
588 write_unlock(&journal
->j_state_lock
);
593 * Return 1 if a given transaction has not yet sent barrier request
594 * connected with a transaction commit. If 0 is returned, transaction
595 * may or may not have sent the barrier. Used to avoid sending barrier
596 * twice in common cases.
598 int jbd2_trans_will_send_data_barrier(journal_t
*journal
, tid_t tid
)
601 transaction_t
*commit_trans
;
603 if (!(journal
->j_flags
& JBD2_BARRIER
))
605 read_lock(&journal
->j_state_lock
);
606 /* Transaction already committed? */
607 if (tid_geq(journal
->j_commit_sequence
, tid
))
609 commit_trans
= journal
->j_committing_transaction
;
610 if (!commit_trans
|| commit_trans
->t_tid
!= tid
) {
615 * Transaction is being committed and we already proceeded to
616 * submitting a flush to fs partition?
618 if (journal
->j_fs_dev
!= journal
->j_dev
) {
619 if (!commit_trans
->t_need_data_flush
||
620 commit_trans
->t_state
>= T_COMMIT_DFLUSH
)
623 if (commit_trans
->t_state
>= T_COMMIT_JFLUSH
)
628 read_unlock(&journal
->j_state_lock
);
631 EXPORT_SYMBOL(jbd2_trans_will_send_data_barrier
);
634 * Wait for a specified commit to complete.
635 * The caller may not hold the journal lock.
637 int jbd2_log_wait_commit(journal_t
*journal
, tid_t tid
)
641 read_lock(&journal
->j_state_lock
);
642 #ifdef CONFIG_JBD2_DEBUG
643 if (!tid_geq(journal
->j_commit_request
, tid
)) {
645 "%s: error: j_commit_request=%d, tid=%d\n",
646 __func__
, journal
->j_commit_request
, tid
);
649 while (tid_gt(tid
, journal
->j_commit_sequence
)) {
650 jbd_debug(1, "JBD2: want %d, j_commit_sequence=%d\n",
651 tid
, journal
->j_commit_sequence
);
652 wake_up(&journal
->j_wait_commit
);
653 read_unlock(&journal
->j_state_lock
);
654 wait_event(journal
->j_wait_done_commit
,
655 !tid_gt(tid
, journal
->j_commit_sequence
));
656 read_lock(&journal
->j_state_lock
);
658 read_unlock(&journal
->j_state_lock
);
660 if (unlikely(is_journal_aborted(journal
))) {
661 printk(KERN_EMERG
"journal commit I/O error\n");
668 * Log buffer allocation routines:
671 int jbd2_journal_next_log_block(journal_t
*journal
, unsigned long long *retp
)
673 unsigned long blocknr
;
675 write_lock(&journal
->j_state_lock
);
676 J_ASSERT(journal
->j_free
> 1);
678 blocknr
= journal
->j_head
;
681 if (journal
->j_head
== journal
->j_last
)
682 journal
->j_head
= journal
->j_first
;
683 write_unlock(&journal
->j_state_lock
);
684 return jbd2_journal_bmap(journal
, blocknr
, retp
);
688 * Conversion of logical to physical block numbers for the journal
690 * On external journals the journal blocks are identity-mapped, so
691 * this is a no-op. If needed, we can use j_blk_offset - everything is
694 int jbd2_journal_bmap(journal_t
*journal
, unsigned long blocknr
,
695 unsigned long long *retp
)
698 unsigned long long ret
;
700 if (journal
->j_inode
) {
701 ret
= bmap(journal
->j_inode
, blocknr
);
705 printk(KERN_ALERT
"%s: journal block not found "
706 "at offset %lu on %s\n",
707 __func__
, blocknr
, journal
->j_devname
);
709 __journal_abort_soft(journal
, err
);
712 *retp
= blocknr
; /* +journal->j_blk_offset */
718 * We play buffer_head aliasing tricks to write data/metadata blocks to
719 * the journal without copying their contents, but for journal
720 * descriptor blocks we do need to generate bona fide buffers.
722 * After the caller of jbd2_journal_get_descriptor_buffer() has finished modifying
723 * the buffer's contents they really should run flush_dcache_page(bh->b_page).
724 * But we don't bother doing that, so there will be coherency problems with
725 * mmaps of blockdevs which hold live JBD-controlled filesystems.
727 struct journal_head
*jbd2_journal_get_descriptor_buffer(journal_t
*journal
)
729 struct buffer_head
*bh
;
730 unsigned long long blocknr
;
733 err
= jbd2_journal_next_log_block(journal
, &blocknr
);
738 bh
= __getblk(journal
->j_dev
, blocknr
, journal
->j_blocksize
);
742 memset(bh
->b_data
, 0, journal
->j_blocksize
);
743 set_buffer_uptodate(bh
);
745 BUFFER_TRACE(bh
, "return this buffer");
746 return jbd2_journal_add_journal_head(bh
);
749 struct jbd2_stats_proc_session
{
751 struct transaction_stats_s
*stats
;
756 static void *jbd2_seq_info_start(struct seq_file
*seq
, loff_t
*pos
)
758 return *pos
? NULL
: SEQ_START_TOKEN
;
761 static void *jbd2_seq_info_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
766 static int jbd2_seq_info_show(struct seq_file
*seq
, void *v
)
768 struct jbd2_stats_proc_session
*s
= seq
->private;
770 if (v
!= SEQ_START_TOKEN
)
772 seq_printf(seq
, "%lu transaction, each up to %u blocks\n",
774 s
->journal
->j_max_transaction_buffers
);
775 if (s
->stats
->ts_tid
== 0)
777 seq_printf(seq
, "average: \n %ums waiting for transaction\n",
778 jiffies_to_msecs(s
->stats
->run
.rs_wait
/ s
->stats
->ts_tid
));
779 seq_printf(seq
, " %ums running transaction\n",
780 jiffies_to_msecs(s
->stats
->run
.rs_running
/ s
->stats
->ts_tid
));
781 seq_printf(seq
, " %ums transaction was being locked\n",
782 jiffies_to_msecs(s
->stats
->run
.rs_locked
/ s
->stats
->ts_tid
));
783 seq_printf(seq
, " %ums flushing data (in ordered mode)\n",
784 jiffies_to_msecs(s
->stats
->run
.rs_flushing
/ s
->stats
->ts_tid
));
785 seq_printf(seq
, " %ums logging transaction\n",
786 jiffies_to_msecs(s
->stats
->run
.rs_logging
/ s
->stats
->ts_tid
));
787 seq_printf(seq
, " %lluus average transaction commit time\n",
788 div_u64(s
->journal
->j_average_commit_time
, 1000));
789 seq_printf(seq
, " %lu handles per transaction\n",
790 s
->stats
->run
.rs_handle_count
/ s
->stats
->ts_tid
);
791 seq_printf(seq
, " %lu blocks per transaction\n",
792 s
->stats
->run
.rs_blocks
/ s
->stats
->ts_tid
);
793 seq_printf(seq
, " %lu logged blocks per transaction\n",
794 s
->stats
->run
.rs_blocks_logged
/ s
->stats
->ts_tid
);
798 static void jbd2_seq_info_stop(struct seq_file
*seq
, void *v
)
802 static const struct seq_operations jbd2_seq_info_ops
= {
803 .start
= jbd2_seq_info_start
,
804 .next
= jbd2_seq_info_next
,
805 .stop
= jbd2_seq_info_stop
,
806 .show
= jbd2_seq_info_show
,
809 static int jbd2_seq_info_open(struct inode
*inode
, struct file
*file
)
811 journal_t
*journal
= PDE(inode
)->data
;
812 struct jbd2_stats_proc_session
*s
;
815 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
818 size
= sizeof(struct transaction_stats_s
);
819 s
->stats
= kmalloc(size
, GFP_KERNEL
);
820 if (s
->stats
== NULL
) {
824 spin_lock(&journal
->j_history_lock
);
825 memcpy(s
->stats
, &journal
->j_stats
, size
);
826 s
->journal
= journal
;
827 spin_unlock(&journal
->j_history_lock
);
829 rc
= seq_open(file
, &jbd2_seq_info_ops
);
831 struct seq_file
*m
= file
->private_data
;
841 static int jbd2_seq_info_release(struct inode
*inode
, struct file
*file
)
843 struct seq_file
*seq
= file
->private_data
;
844 struct jbd2_stats_proc_session
*s
= seq
->private;
847 return seq_release(inode
, file
);
850 static const struct file_operations jbd2_seq_info_fops
= {
851 .owner
= THIS_MODULE
,
852 .open
= jbd2_seq_info_open
,
855 .release
= jbd2_seq_info_release
,
858 static struct proc_dir_entry
*proc_jbd2_stats
;
860 static void jbd2_stats_proc_init(journal_t
*journal
)
862 journal
->j_proc_entry
= proc_mkdir(journal
->j_devname
, proc_jbd2_stats
);
863 if (journal
->j_proc_entry
) {
864 proc_create_data("info", S_IRUGO
, journal
->j_proc_entry
,
865 &jbd2_seq_info_fops
, journal
);
869 static void jbd2_stats_proc_exit(journal_t
*journal
)
871 remove_proc_entry("info", journal
->j_proc_entry
);
872 remove_proc_entry(journal
->j_devname
, proc_jbd2_stats
);
876 * Management for journal control blocks: functions to create and
877 * destroy journal_t structures, and to initialise and read existing
878 * journal blocks from disk. */
880 /* First: create and setup a journal_t object in memory. We initialise
881 * very few fields yet: that has to wait until we have created the
882 * journal structures from from scratch, or loaded them from disk. */
884 static journal_t
* journal_init_common (void)
889 journal
= kzalloc(sizeof(*journal
), GFP_KERNEL
);
893 init_waitqueue_head(&journal
->j_wait_transaction_locked
);
894 init_waitqueue_head(&journal
->j_wait_logspace
);
895 init_waitqueue_head(&journal
->j_wait_done_commit
);
896 init_waitqueue_head(&journal
->j_wait_checkpoint
);
897 init_waitqueue_head(&journal
->j_wait_commit
);
898 init_waitqueue_head(&journal
->j_wait_updates
);
899 mutex_init(&journal
->j_barrier
);
900 mutex_init(&journal
->j_checkpoint_mutex
);
901 spin_lock_init(&journal
->j_revoke_lock
);
902 spin_lock_init(&journal
->j_list_lock
);
903 rwlock_init(&journal
->j_state_lock
);
905 journal
->j_commit_interval
= (HZ
* JBD2_DEFAULT_MAX_COMMIT_AGE
);
906 journal
->j_min_batch_time
= 0;
907 journal
->j_max_batch_time
= 15000; /* 15ms */
909 /* The journal is marked for error until we succeed with recovery! */
910 journal
->j_flags
= JBD2_ABORT
;
912 /* Set up a default-sized revoke table for the new mount. */
913 err
= jbd2_journal_init_revoke(journal
, JOURNAL_REVOKE_DEFAULT_HASH
);
919 spin_lock_init(&journal
->j_history_lock
);
924 /* jbd2_journal_init_dev and jbd2_journal_init_inode:
926 * Create a journal structure assigned some fixed set of disk blocks to
927 * the journal. We don't actually touch those disk blocks yet, but we
928 * need to set up all of the mapping information to tell the journaling
929 * system where the journal blocks are.
934 * journal_t * jbd2_journal_init_dev() - creates and initialises a journal structure
935 * @bdev: Block device on which to create the journal
936 * @fs_dev: Device which hold journalled filesystem for this journal.
937 * @start: Block nr Start of journal.
938 * @len: Length of the journal in blocks.
939 * @blocksize: blocksize of journalling device
941 * Returns: a newly created journal_t *
943 * jbd2_journal_init_dev creates a journal which maps a fixed contiguous
944 * range of blocks on an arbitrary block device.
947 journal_t
* jbd2_journal_init_dev(struct block_device
*bdev
,
948 struct block_device
*fs_dev
,
949 unsigned long long start
, int len
, int blocksize
)
951 journal_t
*journal
= journal_init_common();
952 struct buffer_head
*bh
;
959 /* journal descriptor can store up to n blocks -bzzz */
960 journal
->j_blocksize
= blocksize
;
961 journal
->j_dev
= bdev
;
962 journal
->j_fs_dev
= fs_dev
;
963 journal
->j_blk_offset
= start
;
964 journal
->j_maxlen
= len
;
965 bdevname(journal
->j_dev
, journal
->j_devname
);
966 p
= journal
->j_devname
;
967 while ((p
= strchr(p
, '/')))
969 jbd2_stats_proc_init(journal
);
970 n
= journal
->j_blocksize
/ sizeof(journal_block_tag_t
);
971 journal
->j_wbufsize
= n
;
972 journal
->j_wbuf
= kmalloc(n
* sizeof(struct buffer_head
*), GFP_KERNEL
);
973 if (!journal
->j_wbuf
) {
974 printk(KERN_ERR
"%s: Can't allocate bhs for commit thread\n",
979 bh
= __getblk(journal
->j_dev
, start
, journal
->j_blocksize
);
982 "%s: Cannot get buffer for journal superblock\n",
986 journal
->j_sb_buffer
= bh
;
987 journal
->j_superblock
= (journal_superblock_t
*)bh
->b_data
;
991 kfree(journal
->j_wbuf
);
992 jbd2_stats_proc_exit(journal
);
998 * journal_t * jbd2_journal_init_inode () - creates a journal which maps to a inode.
999 * @inode: An inode to create the journal in
1001 * jbd2_journal_init_inode creates a journal which maps an on-disk inode as
1002 * the journal. The inode must exist already, must support bmap() and
1003 * must have all data blocks preallocated.
1005 journal_t
* jbd2_journal_init_inode (struct inode
*inode
)
1007 struct buffer_head
*bh
;
1008 journal_t
*journal
= journal_init_common();
1012 unsigned long long blocknr
;
1017 journal
->j_dev
= journal
->j_fs_dev
= inode
->i_sb
->s_bdev
;
1018 journal
->j_inode
= inode
;
1019 bdevname(journal
->j_dev
, journal
->j_devname
);
1020 p
= journal
->j_devname
;
1021 while ((p
= strchr(p
, '/')))
1023 p
= journal
->j_devname
+ strlen(journal
->j_devname
);
1024 sprintf(p
, "-%lu", journal
->j_inode
->i_ino
);
1026 "journal %p: inode %s/%ld, size %Ld, bits %d, blksize %ld\n",
1027 journal
, inode
->i_sb
->s_id
, inode
->i_ino
,
1028 (long long) inode
->i_size
,
1029 inode
->i_sb
->s_blocksize_bits
, inode
->i_sb
->s_blocksize
);
1031 journal
->j_maxlen
= inode
->i_size
>> inode
->i_sb
->s_blocksize_bits
;
1032 journal
->j_blocksize
= inode
->i_sb
->s_blocksize
;
1033 jbd2_stats_proc_init(journal
);
1035 /* journal descriptor can store up to n blocks -bzzz */
1036 n
= journal
->j_blocksize
/ sizeof(journal_block_tag_t
);
1037 journal
->j_wbufsize
= n
;
1038 journal
->j_wbuf
= kmalloc(n
* sizeof(struct buffer_head
*), GFP_KERNEL
);
1039 if (!journal
->j_wbuf
) {
1040 printk(KERN_ERR
"%s: Can't allocate bhs for commit thread\n",
1045 err
= jbd2_journal_bmap(journal
, 0, &blocknr
);
1046 /* If that failed, give up */
1048 printk(KERN_ERR
"%s: Cannot locate journal superblock\n",
1053 bh
= __getblk(journal
->j_dev
, blocknr
, journal
->j_blocksize
);
1056 "%s: Cannot get buffer for journal superblock\n",
1060 journal
->j_sb_buffer
= bh
;
1061 journal
->j_superblock
= (journal_superblock_t
*)bh
->b_data
;
1065 kfree(journal
->j_wbuf
);
1066 jbd2_stats_proc_exit(journal
);
1072 * If the journal init or create aborts, we need to mark the journal
1073 * superblock as being NULL to prevent the journal destroy from writing
1074 * back a bogus superblock.
1076 static void journal_fail_superblock (journal_t
*journal
)
1078 struct buffer_head
*bh
= journal
->j_sb_buffer
;
1080 journal
->j_sb_buffer
= NULL
;
1084 * Given a journal_t structure, initialise the various fields for
1085 * startup of a new journaling session. We use this both when creating
1086 * a journal, and after recovering an old journal to reset it for
1090 static int journal_reset(journal_t
*journal
)
1092 journal_superblock_t
*sb
= journal
->j_superblock
;
1093 unsigned long long first
, last
;
1095 first
= be32_to_cpu(sb
->s_first
);
1096 last
= be32_to_cpu(sb
->s_maxlen
);
1097 if (first
+ JBD2_MIN_JOURNAL_BLOCKS
> last
+ 1) {
1098 printk(KERN_ERR
"JBD2: Journal too short (blocks %llu-%llu).\n",
1100 journal_fail_superblock(journal
);
1104 journal
->j_first
= first
;
1105 journal
->j_last
= last
;
1107 journal
->j_head
= first
;
1108 journal
->j_tail
= first
;
1109 journal
->j_free
= last
- first
;
1111 journal
->j_tail_sequence
= journal
->j_transaction_sequence
;
1112 journal
->j_commit_sequence
= journal
->j_transaction_sequence
- 1;
1113 journal
->j_commit_request
= journal
->j_commit_sequence
;
1115 journal
->j_max_transaction_buffers
= journal
->j_maxlen
/ 4;
1117 /* Add the dynamic fields and write it to disk. */
1118 jbd2_journal_update_superblock(journal
, 1);
1119 return jbd2_journal_start_thread(journal
);
1123 * void jbd2_journal_update_superblock() - Update journal sb on disk.
1124 * @journal: The journal to update.
1125 * @wait: Set to '0' if you don't want to wait for IO completion.
1127 * Update a journal's dynamic superblock fields and write it to disk,
1128 * optionally waiting for the IO to complete.
1130 void jbd2_journal_update_superblock(journal_t
*journal
, int wait
)
1132 journal_superblock_t
*sb
= journal
->j_superblock
;
1133 struct buffer_head
*bh
= journal
->j_sb_buffer
;
1136 * As a special case, if the on-disk copy is already marked as needing
1137 * no recovery (s_start == 0) and there are no outstanding transactions
1138 * in the filesystem, then we can safely defer the superblock update
1139 * until the next commit by setting JBD2_FLUSHED. This avoids
1140 * attempting a write to a potential-readonly device.
1142 if (sb
->s_start
== 0 && journal
->j_tail_sequence
==
1143 journal
->j_transaction_sequence
) {
1144 jbd_debug(1, "JBD2: Skipping superblock update on recovered sb "
1145 "(start %ld, seq %d, errno %d)\n",
1146 journal
->j_tail
, journal
->j_tail_sequence
,
1151 if (buffer_write_io_error(bh
)) {
1153 * Oh, dear. A previous attempt to write the journal
1154 * superblock failed. This could happen because the
1155 * USB device was yanked out. Or it could happen to
1156 * be a transient write error and maybe the block will
1157 * be remapped. Nothing we can do but to retry the
1158 * write and hope for the best.
1160 printk(KERN_ERR
"JBD2: previous I/O error detected "
1161 "for journal superblock update for %s.\n",
1162 journal
->j_devname
);
1163 clear_buffer_write_io_error(bh
);
1164 set_buffer_uptodate(bh
);
1167 read_lock(&journal
->j_state_lock
);
1168 jbd_debug(1, "JBD2: updating superblock (start %ld, seq %d, errno %d)\n",
1169 journal
->j_tail
, journal
->j_tail_sequence
, journal
->j_errno
);
1171 sb
->s_sequence
= cpu_to_be32(journal
->j_tail_sequence
);
1172 sb
->s_start
= cpu_to_be32(journal
->j_tail
);
1173 sb
->s_errno
= cpu_to_be32(journal
->j_errno
);
1174 read_unlock(&journal
->j_state_lock
);
1176 BUFFER_TRACE(bh
, "marking dirty");
1177 mark_buffer_dirty(bh
);
1179 sync_dirty_buffer(bh
);
1180 if (buffer_write_io_error(bh
)) {
1181 printk(KERN_ERR
"JBD2: I/O error detected "
1182 "when updating journal superblock for %s.\n",
1183 journal
->j_devname
);
1184 clear_buffer_write_io_error(bh
);
1185 set_buffer_uptodate(bh
);
1188 write_dirty_buffer(bh
, WRITE
);
1191 /* If we have just flushed the log (by marking s_start==0), then
1192 * any future commit will have to be careful to update the
1193 * superblock again to re-record the true start of the log. */
1195 write_lock(&journal
->j_state_lock
);
1197 journal
->j_flags
&= ~JBD2_FLUSHED
;
1199 journal
->j_flags
|= JBD2_FLUSHED
;
1200 write_unlock(&journal
->j_state_lock
);
1204 * Read the superblock for a given journal, performing initial
1205 * validation of the format.
1208 static int journal_get_superblock(journal_t
*journal
)
1210 struct buffer_head
*bh
;
1211 journal_superblock_t
*sb
;
1214 bh
= journal
->j_sb_buffer
;
1216 J_ASSERT(bh
!= NULL
);
1217 if (!buffer_uptodate(bh
)) {
1218 ll_rw_block(READ
, 1, &bh
);
1220 if (!buffer_uptodate(bh
)) {
1222 "JBD2: IO error reading journal superblock\n");
1227 sb
= journal
->j_superblock
;
1231 if (sb
->s_header
.h_magic
!= cpu_to_be32(JBD2_MAGIC_NUMBER
) ||
1232 sb
->s_blocksize
!= cpu_to_be32(journal
->j_blocksize
)) {
1233 printk(KERN_WARNING
"JBD2: no valid journal superblock found\n");
1237 switch(be32_to_cpu(sb
->s_header
.h_blocktype
)) {
1238 case JBD2_SUPERBLOCK_V1
:
1239 journal
->j_format_version
= 1;
1241 case JBD2_SUPERBLOCK_V2
:
1242 journal
->j_format_version
= 2;
1245 printk(KERN_WARNING
"JBD2: unrecognised superblock format ID\n");
1249 if (be32_to_cpu(sb
->s_maxlen
) < journal
->j_maxlen
)
1250 journal
->j_maxlen
= be32_to_cpu(sb
->s_maxlen
);
1251 else if (be32_to_cpu(sb
->s_maxlen
) > journal
->j_maxlen
) {
1252 printk(KERN_WARNING
"JBD2: journal file too short\n");
1256 if (be32_to_cpu(sb
->s_first
) == 0 ||
1257 be32_to_cpu(sb
->s_first
) >= journal
->j_maxlen
) {
1259 "JBD2: Invalid start block of journal: %u\n",
1260 be32_to_cpu(sb
->s_first
));
1267 journal_fail_superblock(journal
);
1272 * Load the on-disk journal superblock and read the key fields into the
1276 static int load_superblock(journal_t
*journal
)
1279 journal_superblock_t
*sb
;
1281 err
= journal_get_superblock(journal
);
1285 sb
= journal
->j_superblock
;
1287 journal
->j_tail_sequence
= be32_to_cpu(sb
->s_sequence
);
1288 journal
->j_tail
= be32_to_cpu(sb
->s_start
);
1289 journal
->j_first
= be32_to_cpu(sb
->s_first
);
1290 journal
->j_last
= be32_to_cpu(sb
->s_maxlen
);
1291 journal
->j_errno
= be32_to_cpu(sb
->s_errno
);
1298 * int jbd2_journal_load() - Read journal from disk.
1299 * @journal: Journal to act on.
1301 * Given a journal_t structure which tells us which disk blocks contain
1302 * a journal, read the journal from disk to initialise the in-memory
1305 int jbd2_journal_load(journal_t
*journal
)
1308 journal_superblock_t
*sb
;
1310 err
= load_superblock(journal
);
1314 sb
= journal
->j_superblock
;
1315 /* If this is a V2 superblock, then we have to check the
1316 * features flags on it. */
1318 if (journal
->j_format_version
>= 2) {
1319 if ((sb
->s_feature_ro_compat
&
1320 ~cpu_to_be32(JBD2_KNOWN_ROCOMPAT_FEATURES
)) ||
1321 (sb
->s_feature_incompat
&
1322 ~cpu_to_be32(JBD2_KNOWN_INCOMPAT_FEATURES
))) {
1324 "JBD2: Unrecognised features on journal\n");
1330 * Create a slab for this blocksize
1332 err
= jbd2_journal_create_slab(be32_to_cpu(sb
->s_blocksize
));
1336 /* Let the recovery code check whether it needs to recover any
1337 * data from the journal. */
1338 if (jbd2_journal_recover(journal
))
1339 goto recovery_error
;
1341 if (journal
->j_failed_commit
) {
1342 printk(KERN_ERR
"JBD2: journal transaction %u on %s "
1343 "is corrupt.\n", journal
->j_failed_commit
,
1344 journal
->j_devname
);
1348 /* OK, we've finished with the dynamic journal bits:
1349 * reinitialise the dynamic contents of the superblock in memory
1350 * and reset them on disk. */
1351 if (journal_reset(journal
))
1352 goto recovery_error
;
1354 journal
->j_flags
&= ~JBD2_ABORT
;
1355 journal
->j_flags
|= JBD2_LOADED
;
1359 printk(KERN_WARNING
"JBD2: recovery failed\n");
1364 * void jbd2_journal_destroy() - Release a journal_t structure.
1365 * @journal: Journal to act on.
1367 * Release a journal_t structure once it is no longer in use by the
1369 * Return <0 if we couldn't clean up the journal.
1371 int jbd2_journal_destroy(journal_t
*journal
)
1375 /* Wait for the commit thread to wake up and die. */
1376 journal_kill_thread(journal
);
1378 /* Force a final log commit */
1379 if (journal
->j_running_transaction
)
1380 jbd2_journal_commit_transaction(journal
);
1382 /* Force any old transactions to disk */
1384 /* Totally anal locking here... */
1385 spin_lock(&journal
->j_list_lock
);
1386 while (journal
->j_checkpoint_transactions
!= NULL
) {
1387 spin_unlock(&journal
->j_list_lock
);
1388 mutex_lock(&journal
->j_checkpoint_mutex
);
1389 jbd2_log_do_checkpoint(journal
);
1390 mutex_unlock(&journal
->j_checkpoint_mutex
);
1391 spin_lock(&journal
->j_list_lock
);
1394 J_ASSERT(journal
->j_running_transaction
== NULL
);
1395 J_ASSERT(journal
->j_committing_transaction
== NULL
);
1396 J_ASSERT(journal
->j_checkpoint_transactions
== NULL
);
1397 spin_unlock(&journal
->j_list_lock
);
1399 if (journal
->j_sb_buffer
) {
1400 if (!is_journal_aborted(journal
)) {
1401 /* We can now mark the journal as empty. */
1402 journal
->j_tail
= 0;
1403 journal
->j_tail_sequence
=
1404 ++journal
->j_transaction_sequence
;
1405 jbd2_journal_update_superblock(journal
, 1);
1409 brelse(journal
->j_sb_buffer
);
1412 if (journal
->j_proc_entry
)
1413 jbd2_stats_proc_exit(journal
);
1414 if (journal
->j_inode
)
1415 iput(journal
->j_inode
);
1416 if (journal
->j_revoke
)
1417 jbd2_journal_destroy_revoke(journal
);
1418 kfree(journal
->j_wbuf
);
1426 *int jbd2_journal_check_used_features () - Check if features specified are used.
1427 * @journal: Journal to check.
1428 * @compat: bitmask of compatible features
1429 * @ro: bitmask of features that force read-only mount
1430 * @incompat: bitmask of incompatible features
1432 * Check whether the journal uses all of a given set of
1433 * features. Return true (non-zero) if it does.
1436 int jbd2_journal_check_used_features (journal_t
*journal
, unsigned long compat
,
1437 unsigned long ro
, unsigned long incompat
)
1439 journal_superblock_t
*sb
;
1441 if (!compat
&& !ro
&& !incompat
)
1443 /* Load journal superblock if it is not loaded yet. */
1444 if (journal
->j_format_version
== 0 &&
1445 journal_get_superblock(journal
) != 0)
1447 if (journal
->j_format_version
== 1)
1450 sb
= journal
->j_superblock
;
1452 if (((be32_to_cpu(sb
->s_feature_compat
) & compat
) == compat
) &&
1453 ((be32_to_cpu(sb
->s_feature_ro_compat
) & ro
) == ro
) &&
1454 ((be32_to_cpu(sb
->s_feature_incompat
) & incompat
) == incompat
))
1461 * int jbd2_journal_check_available_features() - Check feature set in journalling layer
1462 * @journal: Journal to check.
1463 * @compat: bitmask of compatible features
1464 * @ro: bitmask of features that force read-only mount
1465 * @incompat: bitmask of incompatible features
1467 * Check whether the journaling code supports the use of
1468 * all of a given set of features on this journal. Return true
1469 * (non-zero) if it can. */
1471 int jbd2_journal_check_available_features (journal_t
*journal
, unsigned long compat
,
1472 unsigned long ro
, unsigned long incompat
)
1474 if (!compat
&& !ro
&& !incompat
)
1477 /* We can support any known requested features iff the
1478 * superblock is in version 2. Otherwise we fail to support any
1479 * extended sb features. */
1481 if (journal
->j_format_version
!= 2)
1484 if ((compat
& JBD2_KNOWN_COMPAT_FEATURES
) == compat
&&
1485 (ro
& JBD2_KNOWN_ROCOMPAT_FEATURES
) == ro
&&
1486 (incompat
& JBD2_KNOWN_INCOMPAT_FEATURES
) == incompat
)
1493 * int jbd2_journal_set_features () - Mark a given journal feature in the superblock
1494 * @journal: Journal to act on.
1495 * @compat: bitmask of compatible features
1496 * @ro: bitmask of features that force read-only mount
1497 * @incompat: bitmask of incompatible features
1499 * Mark a given journal feature as present on the
1500 * superblock. Returns true if the requested features could be set.
1504 int jbd2_journal_set_features (journal_t
*journal
, unsigned long compat
,
1505 unsigned long ro
, unsigned long incompat
)
1507 journal_superblock_t
*sb
;
1509 if (jbd2_journal_check_used_features(journal
, compat
, ro
, incompat
))
1512 if (!jbd2_journal_check_available_features(journal
, compat
, ro
, incompat
))
1515 jbd_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n",
1516 compat
, ro
, incompat
);
1518 sb
= journal
->j_superblock
;
1520 sb
->s_feature_compat
|= cpu_to_be32(compat
);
1521 sb
->s_feature_ro_compat
|= cpu_to_be32(ro
);
1522 sb
->s_feature_incompat
|= cpu_to_be32(incompat
);
1528 * jbd2_journal_clear_features () - Clear a given journal feature in the
1530 * @journal: Journal to act on.
1531 * @compat: bitmask of compatible features
1532 * @ro: bitmask of features that force read-only mount
1533 * @incompat: bitmask of incompatible features
1535 * Clear a given journal feature as present on the
1538 void jbd2_journal_clear_features(journal_t
*journal
, unsigned long compat
,
1539 unsigned long ro
, unsigned long incompat
)
1541 journal_superblock_t
*sb
;
1543 jbd_debug(1, "Clear features 0x%lx/0x%lx/0x%lx\n",
1544 compat
, ro
, incompat
);
1546 sb
= journal
->j_superblock
;
1548 sb
->s_feature_compat
&= ~cpu_to_be32(compat
);
1549 sb
->s_feature_ro_compat
&= ~cpu_to_be32(ro
);
1550 sb
->s_feature_incompat
&= ~cpu_to_be32(incompat
);
1552 EXPORT_SYMBOL(jbd2_journal_clear_features
);
1555 * int jbd2_journal_update_format () - Update on-disk journal structure.
1556 * @journal: Journal to act on.
1558 * Given an initialised but unloaded journal struct, poke about in the
1559 * on-disk structure to update it to the most recent supported version.
1561 int jbd2_journal_update_format (journal_t
*journal
)
1563 journal_superblock_t
*sb
;
1566 err
= journal_get_superblock(journal
);
1570 sb
= journal
->j_superblock
;
1572 switch (be32_to_cpu(sb
->s_header
.h_blocktype
)) {
1573 case JBD2_SUPERBLOCK_V2
:
1575 case JBD2_SUPERBLOCK_V1
:
1576 return journal_convert_superblock_v1(journal
, sb
);
1583 static int journal_convert_superblock_v1(journal_t
*journal
,
1584 journal_superblock_t
*sb
)
1586 int offset
, blocksize
;
1587 struct buffer_head
*bh
;
1590 "JBD2: Converting superblock from version 1 to 2.\n");
1592 /* Pre-initialise new fields to zero */
1593 offset
= ((char *) &(sb
->s_feature_compat
)) - ((char *) sb
);
1594 blocksize
= be32_to_cpu(sb
->s_blocksize
);
1595 memset(&sb
->s_feature_compat
, 0, blocksize
-offset
);
1597 sb
->s_nr_users
= cpu_to_be32(1);
1598 sb
->s_header
.h_blocktype
= cpu_to_be32(JBD2_SUPERBLOCK_V2
);
1599 journal
->j_format_version
= 2;
1601 bh
= journal
->j_sb_buffer
;
1602 BUFFER_TRACE(bh
, "marking dirty");
1603 mark_buffer_dirty(bh
);
1604 sync_dirty_buffer(bh
);
1610 * int jbd2_journal_flush () - Flush journal
1611 * @journal: Journal to act on.
1613 * Flush all data for a given journal to disk and empty the journal.
1614 * Filesystems can use this when remounting readonly to ensure that
1615 * recovery does not need to happen on remount.
1618 int jbd2_journal_flush(journal_t
*journal
)
1621 transaction_t
*transaction
= NULL
;
1622 unsigned long old_tail
;
1624 write_lock(&journal
->j_state_lock
);
1626 /* Force everything buffered to the log... */
1627 if (journal
->j_running_transaction
) {
1628 transaction
= journal
->j_running_transaction
;
1629 __jbd2_log_start_commit(journal
, transaction
->t_tid
);
1630 } else if (journal
->j_committing_transaction
)
1631 transaction
= journal
->j_committing_transaction
;
1633 /* Wait for the log commit to complete... */
1635 tid_t tid
= transaction
->t_tid
;
1637 write_unlock(&journal
->j_state_lock
);
1638 jbd2_log_wait_commit(journal
, tid
);
1640 write_unlock(&journal
->j_state_lock
);
1643 /* ...and flush everything in the log out to disk. */
1644 spin_lock(&journal
->j_list_lock
);
1645 while (!err
&& journal
->j_checkpoint_transactions
!= NULL
) {
1646 spin_unlock(&journal
->j_list_lock
);
1647 mutex_lock(&journal
->j_checkpoint_mutex
);
1648 err
= jbd2_log_do_checkpoint(journal
);
1649 mutex_unlock(&journal
->j_checkpoint_mutex
);
1650 spin_lock(&journal
->j_list_lock
);
1652 spin_unlock(&journal
->j_list_lock
);
1654 if (is_journal_aborted(journal
))
1657 jbd2_cleanup_journal_tail(journal
);
1659 /* Finally, mark the journal as really needing no recovery.
1660 * This sets s_start==0 in the underlying superblock, which is
1661 * the magic code for a fully-recovered superblock. Any future
1662 * commits of data to the journal will restore the current
1664 write_lock(&journal
->j_state_lock
);
1665 old_tail
= journal
->j_tail
;
1666 journal
->j_tail
= 0;
1667 write_unlock(&journal
->j_state_lock
);
1668 jbd2_journal_update_superblock(journal
, 1);
1669 write_lock(&journal
->j_state_lock
);
1670 journal
->j_tail
= old_tail
;
1672 J_ASSERT(!journal
->j_running_transaction
);
1673 J_ASSERT(!journal
->j_committing_transaction
);
1674 J_ASSERT(!journal
->j_checkpoint_transactions
);
1675 J_ASSERT(journal
->j_head
== journal
->j_tail
);
1676 J_ASSERT(journal
->j_tail_sequence
== journal
->j_transaction_sequence
);
1677 write_unlock(&journal
->j_state_lock
);
1682 * int jbd2_journal_wipe() - Wipe journal contents
1683 * @journal: Journal to act on.
1684 * @write: flag (see below)
1686 * Wipe out all of the contents of a journal, safely. This will produce
1687 * a warning if the journal contains any valid recovery information.
1688 * Must be called between journal_init_*() and jbd2_journal_load().
1690 * If 'write' is non-zero, then we wipe out the journal on disk; otherwise
1691 * we merely suppress recovery.
1694 int jbd2_journal_wipe(journal_t
*journal
, int write
)
1698 J_ASSERT (!(journal
->j_flags
& JBD2_LOADED
));
1700 err
= load_superblock(journal
);
1704 if (!journal
->j_tail
)
1707 printk(KERN_WARNING
"JBD2: %s recovery information on journal\n",
1708 write
? "Clearing" : "Ignoring");
1710 err
= jbd2_journal_skip_recovery(journal
);
1712 jbd2_journal_update_superblock(journal
, 1);
1719 * Journal abort has very specific semantics, which we describe
1720 * for journal abort.
1722 * Two internal functions, which provide abort to the jbd layer
1727 * Quick version for internal journal use (doesn't lock the journal).
1728 * Aborts hard --- we mark the abort as occurred, but do _nothing_ else,
1729 * and don't attempt to make any other journal updates.
1731 void __jbd2_journal_abort_hard(journal_t
*journal
)
1733 transaction_t
*transaction
;
1735 if (journal
->j_flags
& JBD2_ABORT
)
1738 printk(KERN_ERR
"Aborting journal on device %s.\n",
1739 journal
->j_devname
);
1741 write_lock(&journal
->j_state_lock
);
1742 journal
->j_flags
|= JBD2_ABORT
;
1743 transaction
= journal
->j_running_transaction
;
1745 __jbd2_log_start_commit(journal
, transaction
->t_tid
);
1746 write_unlock(&journal
->j_state_lock
);
1749 /* Soft abort: record the abort error status in the journal superblock,
1750 * but don't do any other IO. */
1751 static void __journal_abort_soft (journal_t
*journal
, int errno
)
1753 if (journal
->j_flags
& JBD2_ABORT
)
1756 if (!journal
->j_errno
)
1757 journal
->j_errno
= errno
;
1759 __jbd2_journal_abort_hard(journal
);
1762 jbd2_journal_update_superblock(journal
, 1);
1766 * void jbd2_journal_abort () - Shutdown the journal immediately.
1767 * @journal: the journal to shutdown.
1768 * @errno: an error number to record in the journal indicating
1769 * the reason for the shutdown.
1771 * Perform a complete, immediate shutdown of the ENTIRE
1772 * journal (not of a single transaction). This operation cannot be
1773 * undone without closing and reopening the journal.
1775 * The jbd2_journal_abort function is intended to support higher level error
1776 * recovery mechanisms such as the ext2/ext3 remount-readonly error
1779 * Journal abort has very specific semantics. Any existing dirty,
1780 * unjournaled buffers in the main filesystem will still be written to
1781 * disk by bdflush, but the journaling mechanism will be suspended
1782 * immediately and no further transaction commits will be honoured.
1784 * Any dirty, journaled buffers will be written back to disk without
1785 * hitting the journal. Atomicity cannot be guaranteed on an aborted
1786 * filesystem, but we _do_ attempt to leave as much data as possible
1787 * behind for fsck to use for cleanup.
1789 * Any attempt to get a new transaction handle on a journal which is in
1790 * ABORT state will just result in an -EROFS error return. A
1791 * jbd2_journal_stop on an existing handle will return -EIO if we have
1792 * entered abort state during the update.
1794 * Recursive transactions are not disturbed by journal abort until the
1795 * final jbd2_journal_stop, which will receive the -EIO error.
1797 * Finally, the jbd2_journal_abort call allows the caller to supply an errno
1798 * which will be recorded (if possible) in the journal superblock. This
1799 * allows a client to record failure conditions in the middle of a
1800 * transaction without having to complete the transaction to record the
1801 * failure to disk. ext3_error, for example, now uses this
1804 * Errors which originate from within the journaling layer will NOT
1805 * supply an errno; a null errno implies that absolutely no further
1806 * writes are done to the journal (unless there are any already in
1811 void jbd2_journal_abort(journal_t
*journal
, int errno
)
1813 __journal_abort_soft(journal
, errno
);
1817 * int jbd2_journal_errno () - returns the journal's error state.
1818 * @journal: journal to examine.
1820 * This is the errno number set with jbd2_journal_abort(), the last
1821 * time the journal was mounted - if the journal was stopped
1822 * without calling abort this will be 0.
1824 * If the journal has been aborted on this mount time -EROFS will
1827 int jbd2_journal_errno(journal_t
*journal
)
1831 read_lock(&journal
->j_state_lock
);
1832 if (journal
->j_flags
& JBD2_ABORT
)
1835 err
= journal
->j_errno
;
1836 read_unlock(&journal
->j_state_lock
);
1841 * int jbd2_journal_clear_err () - clears the journal's error state
1842 * @journal: journal to act on.
1844 * An error must be cleared or acked to take a FS out of readonly
1847 int jbd2_journal_clear_err(journal_t
*journal
)
1851 write_lock(&journal
->j_state_lock
);
1852 if (journal
->j_flags
& JBD2_ABORT
)
1855 journal
->j_errno
= 0;
1856 write_unlock(&journal
->j_state_lock
);
1861 * void jbd2_journal_ack_err() - Ack journal err.
1862 * @journal: journal to act on.
1864 * An error must be cleared or acked to take a FS out of readonly
1867 void jbd2_journal_ack_err(journal_t
*journal
)
1869 write_lock(&journal
->j_state_lock
);
1870 if (journal
->j_errno
)
1871 journal
->j_flags
|= JBD2_ACK_ERR
;
1872 write_unlock(&journal
->j_state_lock
);
1875 int jbd2_journal_blocks_per_page(struct inode
*inode
)
1877 return 1 << (PAGE_CACHE_SHIFT
- inode
->i_sb
->s_blocksize_bits
);
1881 * helper functions to deal with 32 or 64bit block numbers.
1883 size_t journal_tag_bytes(journal_t
*journal
)
1885 if (JBD2_HAS_INCOMPAT_FEATURE(journal
, JBD2_FEATURE_INCOMPAT_64BIT
))
1886 return JBD2_TAG_SIZE64
;
1888 return JBD2_TAG_SIZE32
;
1892 * JBD memory management
1894 * These functions are used to allocate block-sized chunks of memory
1895 * used for making copies of buffer_head data. Very often it will be
1896 * page-sized chunks of data, but sometimes it will be in
1897 * sub-page-size chunks. (For example, 16k pages on Power systems
1898 * with a 4k block file system.) For blocks smaller than a page, we
1899 * use a SLAB allocator. There are slab caches for each block size,
1900 * which are allocated at mount time, if necessary, and we only free
1901 * (all of) the slab caches when/if the jbd2 module is unloaded. For
1902 * this reason we don't need to a mutex to protect access to
1903 * jbd2_slab[] allocating or releasing memory; only in
1904 * jbd2_journal_create_slab().
1906 #define JBD2_MAX_SLABS 8
1907 static struct kmem_cache
*jbd2_slab
[JBD2_MAX_SLABS
];
1909 static const char *jbd2_slab_names
[JBD2_MAX_SLABS
] = {
1910 "jbd2_1k", "jbd2_2k", "jbd2_4k", "jbd2_8k",
1911 "jbd2_16k", "jbd2_32k", "jbd2_64k", "jbd2_128k"
1915 static void jbd2_journal_destroy_slabs(void)
1919 for (i
= 0; i
< JBD2_MAX_SLABS
; i
++) {
1921 kmem_cache_destroy(jbd2_slab
[i
]);
1922 jbd2_slab
[i
] = NULL
;
1926 static int jbd2_journal_create_slab(size_t size
)
1928 static DEFINE_MUTEX(jbd2_slab_create_mutex
);
1929 int i
= order_base_2(size
) - 10;
1932 if (size
== PAGE_SIZE
)
1935 if (i
>= JBD2_MAX_SLABS
)
1938 if (unlikely(i
< 0))
1940 mutex_lock(&jbd2_slab_create_mutex
);
1942 mutex_unlock(&jbd2_slab_create_mutex
);
1943 return 0; /* Already created */
1946 slab_size
= 1 << (i
+10);
1947 jbd2_slab
[i
] = kmem_cache_create(jbd2_slab_names
[i
], slab_size
,
1948 slab_size
, 0, NULL
);
1949 mutex_unlock(&jbd2_slab_create_mutex
);
1950 if (!jbd2_slab
[i
]) {
1951 printk(KERN_EMERG
"JBD2: no memory for jbd2_slab cache\n");
1957 static struct kmem_cache
*get_slab(size_t size
)
1959 int i
= order_base_2(size
) - 10;
1961 BUG_ON(i
>= JBD2_MAX_SLABS
);
1962 if (unlikely(i
< 0))
1964 BUG_ON(jbd2_slab
[i
] == NULL
);
1965 return jbd2_slab
[i
];
1968 void *jbd2_alloc(size_t size
, gfp_t flags
)
1972 BUG_ON(size
& (size
-1)); /* Must be a power of 2 */
1974 flags
|= __GFP_REPEAT
;
1975 if (size
== PAGE_SIZE
)
1976 ptr
= (void *)__get_free_pages(flags
, 0);
1977 else if (size
> PAGE_SIZE
) {
1978 int order
= get_order(size
);
1981 ptr
= (void *)__get_free_pages(flags
, order
);
1983 ptr
= vmalloc(size
);
1985 ptr
= kmem_cache_alloc(get_slab(size
), flags
);
1987 /* Check alignment; SLUB has gotten this wrong in the past,
1988 * and this can lead to user data corruption! */
1989 BUG_ON(((unsigned long) ptr
) & (size
-1));
1994 void jbd2_free(void *ptr
, size_t size
)
1996 if (size
== PAGE_SIZE
) {
1997 free_pages((unsigned long)ptr
, 0);
2000 if (size
> PAGE_SIZE
) {
2001 int order
= get_order(size
);
2004 free_pages((unsigned long)ptr
, order
);
2009 kmem_cache_free(get_slab(size
), ptr
);
2013 * Journal_head storage management
2015 static struct kmem_cache
*jbd2_journal_head_cache
;
2016 #ifdef CONFIG_JBD2_DEBUG
2017 static atomic_t nr_journal_heads
= ATOMIC_INIT(0);
2020 static int journal_init_jbd2_journal_head_cache(void)
2024 J_ASSERT(jbd2_journal_head_cache
== NULL
);
2025 jbd2_journal_head_cache
= kmem_cache_create("jbd2_journal_head",
2026 sizeof(struct journal_head
),
2028 SLAB_TEMPORARY
, /* flags */
2031 if (!jbd2_journal_head_cache
) {
2033 printk(KERN_EMERG
"JBD2: no memory for journal_head cache\n");
2038 static void jbd2_journal_destroy_jbd2_journal_head_cache(void)
2040 if (jbd2_journal_head_cache
) {
2041 kmem_cache_destroy(jbd2_journal_head_cache
);
2042 jbd2_journal_head_cache
= NULL
;
2047 * journal_head splicing and dicing
2049 static struct journal_head
*journal_alloc_journal_head(void)
2051 struct journal_head
*ret
;
2053 #ifdef CONFIG_JBD2_DEBUG
2054 atomic_inc(&nr_journal_heads
);
2056 ret
= kmem_cache_alloc(jbd2_journal_head_cache
, GFP_NOFS
);
2058 jbd_debug(1, "out of memory for journal_head\n");
2059 pr_notice_ratelimited("ENOMEM in %s, retrying.\n", __func__
);
2062 ret
= kmem_cache_alloc(jbd2_journal_head_cache
, GFP_NOFS
);
2068 static void journal_free_journal_head(struct journal_head
*jh
)
2070 #ifdef CONFIG_JBD2_DEBUG
2071 atomic_dec(&nr_journal_heads
);
2072 memset(jh
, JBD2_POISON_FREE
, sizeof(*jh
));
2074 kmem_cache_free(jbd2_journal_head_cache
, jh
);
2078 * A journal_head is attached to a buffer_head whenever JBD has an
2079 * interest in the buffer.
2081 * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit
2082 * is set. This bit is tested in core kernel code where we need to take
2083 * JBD-specific actions. Testing the zeroness of ->b_private is not reliable
2086 * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one.
2088 * When a buffer has its BH_JBD bit set it is immune from being released by
2089 * core kernel code, mainly via ->b_count.
2091 * A journal_head is detached from its buffer_head when the journal_head's
2092 * b_jcount reaches zero. Running transaction (b_transaction) and checkpoint
2093 * transaction (b_cp_transaction) hold their references to b_jcount.
2095 * Various places in the kernel want to attach a journal_head to a buffer_head
2096 * _before_ attaching the journal_head to a transaction. To protect the
2097 * journal_head in this situation, jbd2_journal_add_journal_head elevates the
2098 * journal_head's b_jcount refcount by one. The caller must call
2099 * jbd2_journal_put_journal_head() to undo this.
2101 * So the typical usage would be:
2103 * (Attach a journal_head if needed. Increments b_jcount)
2104 * struct journal_head *jh = jbd2_journal_add_journal_head(bh);
2106 * (Get another reference for transaction)
2107 * jbd2_journal_grab_journal_head(bh);
2108 * jh->b_transaction = xxx;
2109 * (Put original reference)
2110 * jbd2_journal_put_journal_head(jh);
2114 * Give a buffer_head a journal_head.
2118 struct journal_head
*jbd2_journal_add_journal_head(struct buffer_head
*bh
)
2120 struct journal_head
*jh
;
2121 struct journal_head
*new_jh
= NULL
;
2124 if (!buffer_jbd(bh
)) {
2125 new_jh
= journal_alloc_journal_head();
2126 memset(new_jh
, 0, sizeof(*new_jh
));
2129 jbd_lock_bh_journal_head(bh
);
2130 if (buffer_jbd(bh
)) {
2134 (atomic_read(&bh
->b_count
) > 0) ||
2135 (bh
->b_page
&& bh
->b_page
->mapping
));
2138 jbd_unlock_bh_journal_head(bh
);
2143 new_jh
= NULL
; /* We consumed it */
2148 BUFFER_TRACE(bh
, "added journal_head");
2151 jbd_unlock_bh_journal_head(bh
);
2153 journal_free_journal_head(new_jh
);
2154 return bh
->b_private
;
2158 * Grab a ref against this buffer_head's journal_head. If it ended up not
2159 * having a journal_head, return NULL
2161 struct journal_head
*jbd2_journal_grab_journal_head(struct buffer_head
*bh
)
2163 struct journal_head
*jh
= NULL
;
2165 jbd_lock_bh_journal_head(bh
);
2166 if (buffer_jbd(bh
)) {
2170 jbd_unlock_bh_journal_head(bh
);
2174 static void __journal_remove_journal_head(struct buffer_head
*bh
)
2176 struct journal_head
*jh
= bh2jh(bh
);
2178 J_ASSERT_JH(jh
, jh
->b_jcount
>= 0);
2179 J_ASSERT_JH(jh
, jh
->b_transaction
== NULL
);
2180 J_ASSERT_JH(jh
, jh
->b_next_transaction
== NULL
);
2181 J_ASSERT_JH(jh
, jh
->b_cp_transaction
== NULL
);
2182 J_ASSERT_JH(jh
, jh
->b_jlist
== BJ_None
);
2183 J_ASSERT_BH(bh
, buffer_jbd(bh
));
2184 J_ASSERT_BH(bh
, jh2bh(jh
) == bh
);
2185 BUFFER_TRACE(bh
, "remove journal_head");
2186 if (jh
->b_frozen_data
) {
2187 printk(KERN_WARNING
"%s: freeing b_frozen_data\n", __func__
);
2188 jbd2_free(jh
->b_frozen_data
, bh
->b_size
);
2190 if (jh
->b_committed_data
) {
2191 printk(KERN_WARNING
"%s: freeing b_committed_data\n", __func__
);
2192 jbd2_free(jh
->b_committed_data
, bh
->b_size
);
2194 bh
->b_private
= NULL
;
2195 jh
->b_bh
= NULL
; /* debug, really */
2196 clear_buffer_jbd(bh
);
2197 journal_free_journal_head(jh
);
2201 * Drop a reference on the passed journal_head. If it fell to zero then
2202 * release the journal_head from the buffer_head.
2204 void jbd2_journal_put_journal_head(struct journal_head
*jh
)
2206 struct buffer_head
*bh
= jh2bh(jh
);
2208 jbd_lock_bh_journal_head(bh
);
2209 J_ASSERT_JH(jh
, jh
->b_jcount
> 0);
2211 if (!jh
->b_jcount
) {
2212 __journal_remove_journal_head(bh
);
2213 jbd_unlock_bh_journal_head(bh
);
2216 jbd_unlock_bh_journal_head(bh
);
2220 * Initialize jbd inode head
2222 void jbd2_journal_init_jbd_inode(struct jbd2_inode
*jinode
, struct inode
*inode
)
2224 jinode
->i_transaction
= NULL
;
2225 jinode
->i_next_transaction
= NULL
;
2226 jinode
->i_vfs_inode
= inode
;
2227 jinode
->i_flags
= 0;
2228 INIT_LIST_HEAD(&jinode
->i_list
);
2232 * Function to be called before we start removing inode from memory (i.e.,
2233 * clear_inode() is a fine place to be called from). It removes inode from
2234 * transaction's lists.
2236 void jbd2_journal_release_jbd_inode(journal_t
*journal
,
2237 struct jbd2_inode
*jinode
)
2242 spin_lock(&journal
->j_list_lock
);
2243 /* Is commit writing out inode - we have to wait */
2244 if (test_bit(__JI_COMMIT_RUNNING
, &jinode
->i_flags
)) {
2245 wait_queue_head_t
*wq
;
2246 DEFINE_WAIT_BIT(wait
, &jinode
->i_flags
, __JI_COMMIT_RUNNING
);
2247 wq
= bit_waitqueue(&jinode
->i_flags
, __JI_COMMIT_RUNNING
);
2248 prepare_to_wait(wq
, &wait
.wait
, TASK_UNINTERRUPTIBLE
);
2249 spin_unlock(&journal
->j_list_lock
);
2251 finish_wait(wq
, &wait
.wait
);
2255 if (jinode
->i_transaction
) {
2256 list_del(&jinode
->i_list
);
2257 jinode
->i_transaction
= NULL
;
2259 spin_unlock(&journal
->j_list_lock
);
2265 #ifdef CONFIG_JBD2_DEBUG
2266 u8 jbd2_journal_enable_debug __read_mostly
;
2267 EXPORT_SYMBOL(jbd2_journal_enable_debug
);
2269 #define JBD2_DEBUG_NAME "jbd2-debug"
2271 static struct dentry
*jbd2_debugfs_dir
;
2272 static struct dentry
*jbd2_debug
;
2274 static void __init
jbd2_create_debugfs_entry(void)
2276 jbd2_debugfs_dir
= debugfs_create_dir("jbd2", NULL
);
2277 if (jbd2_debugfs_dir
)
2278 jbd2_debug
= debugfs_create_u8(JBD2_DEBUG_NAME
,
2281 &jbd2_journal_enable_debug
);
2284 static void __exit
jbd2_remove_debugfs_entry(void)
2286 debugfs_remove(jbd2_debug
);
2287 debugfs_remove(jbd2_debugfs_dir
);
2292 static void __init
jbd2_create_debugfs_entry(void)
2296 static void __exit
jbd2_remove_debugfs_entry(void)
2302 #ifdef CONFIG_PROC_FS
2304 #define JBD2_STATS_PROC_NAME "fs/jbd2"
2306 static void __init
jbd2_create_jbd_stats_proc_entry(void)
2308 proc_jbd2_stats
= proc_mkdir(JBD2_STATS_PROC_NAME
, NULL
);
2311 static void __exit
jbd2_remove_jbd_stats_proc_entry(void)
2313 if (proc_jbd2_stats
)
2314 remove_proc_entry(JBD2_STATS_PROC_NAME
, NULL
);
2319 #define jbd2_create_jbd_stats_proc_entry() do {} while (0)
2320 #define jbd2_remove_jbd_stats_proc_entry() do {} while (0)
2324 struct kmem_cache
*jbd2_handle_cache
, *jbd2_inode_cache
;
2326 static int __init
journal_init_handle_cache(void)
2328 jbd2_handle_cache
= KMEM_CACHE(jbd2_journal_handle
, SLAB_TEMPORARY
);
2329 if (jbd2_handle_cache
== NULL
) {
2330 printk(KERN_EMERG
"JBD2: failed to create handle cache\n");
2333 jbd2_inode_cache
= KMEM_CACHE(jbd2_inode
, 0);
2334 if (jbd2_inode_cache
== NULL
) {
2335 printk(KERN_EMERG
"JBD2: failed to create inode cache\n");
2336 kmem_cache_destroy(jbd2_handle_cache
);
2342 static void jbd2_journal_destroy_handle_cache(void)
2344 if (jbd2_handle_cache
)
2345 kmem_cache_destroy(jbd2_handle_cache
);
2346 if (jbd2_inode_cache
)
2347 kmem_cache_destroy(jbd2_inode_cache
);
2352 * Module startup and shutdown
2355 static int __init
journal_init_caches(void)
2359 ret
= jbd2_journal_init_revoke_caches();
2361 ret
= journal_init_jbd2_journal_head_cache();
2363 ret
= journal_init_handle_cache();
2367 static void jbd2_journal_destroy_caches(void)
2369 jbd2_journal_destroy_revoke_caches();
2370 jbd2_journal_destroy_jbd2_journal_head_cache();
2371 jbd2_journal_destroy_handle_cache();
2372 jbd2_journal_destroy_slabs();
2375 static int __init
journal_init(void)
2379 BUILD_BUG_ON(sizeof(struct journal_superblock_s
) != 1024);
2381 ret
= journal_init_caches();
2383 jbd2_create_debugfs_entry();
2384 jbd2_create_jbd_stats_proc_entry();
2386 jbd2_journal_destroy_caches();
2391 static void __exit
journal_exit(void)
2393 #ifdef CONFIG_JBD2_DEBUG
2394 int n
= atomic_read(&nr_journal_heads
);
2396 printk(KERN_EMERG
"JBD2: leaked %d journal_heads!\n", n
);
2398 jbd2_remove_debugfs_entry();
2399 jbd2_remove_jbd_stats_proc_entry();
2400 jbd2_journal_destroy_caches();
2403 MODULE_LICENSE("GPL");
2404 module_init(journal_init
);
2405 module_exit(journal_exit
);