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
);
98 static int journal_convert_superblock_v1(journal_t
*, journal_superblock_t
*);
99 static void __journal_abort_soft (journal_t
*journal
, int errno
);
100 static int jbd2_journal_create_slab(size_t slab_size
);
103 * Helper function used to manage commit timeouts
106 static void commit_timeout(unsigned long __data
)
108 struct task_struct
* p
= (struct task_struct
*) __data
;
114 * kjournald2: The main thread function used to manage a logging device
117 * This kernel thread is responsible for two things:
119 * 1) COMMIT: Every so often we need to commit the current state of the
120 * filesystem to disk. The journal thread is responsible for writing
121 * all of the metadata buffers to disk.
123 * 2) CHECKPOINT: We cannot reuse a used section of the log file until all
124 * of the data in that part of the log has been rewritten elsewhere on
125 * the disk. Flushing these old buffers to reclaim space in the log is
126 * known as checkpointing, and this thread is responsible for that job.
129 static int kjournald2(void *arg
)
131 journal_t
*journal
= arg
;
132 transaction_t
*transaction
;
135 * Set up an interval timer which can be used to trigger a commit wakeup
136 * after the commit interval expires
138 setup_timer(&journal
->j_commit_timer
, commit_timeout
,
139 (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
, KM_USER0
);
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
, KM_USER0
);
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
, KM_USER0
);
388 memcpy(tmp
, mapped_data
+ new_offset
, jh2bh(jh_in
)->b_size
);
389 kunmap_atomic(mapped_data
, KM_USER0
);
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
, KM_USER0
);
409 *((unsigned int *)(mapped_data
+ new_offset
)) = 0;
410 kunmap_atomic(mapped_data
, KM_USER0
);
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 under j_state_lock. Returns true if a transaction commit was started.
477 int __jbd2_log_start_commit(journal_t
*journal
, tid_t target
)
480 * Are we already doing a recent enough commit?
482 if (!tid_geq(journal
->j_commit_request
, target
)) {
484 * We want a new commit: OK, mark the request and wakeup the
485 * commit thread. We do _not_ do the commit ourselves.
488 journal
->j_commit_request
= target
;
489 jbd_debug(1, "JBD: requesting commit %d/%d\n",
490 journal
->j_commit_request
,
491 journal
->j_commit_sequence
);
492 wake_up(&journal
->j_wait_commit
);
498 int jbd2_log_start_commit(journal_t
*journal
, tid_t tid
)
502 write_lock(&journal
->j_state_lock
);
503 ret
= __jbd2_log_start_commit(journal
, tid
);
504 write_unlock(&journal
->j_state_lock
);
509 * Force and wait upon a commit if the calling process is not within
510 * transaction. This is used for forcing out undo-protected data which contains
511 * bitmaps, when the fs is running out of space.
513 * We can only force the running transaction if we don't have an active handle;
514 * otherwise, we will deadlock.
516 * Returns true if a transaction was started.
518 int jbd2_journal_force_commit_nested(journal_t
*journal
)
520 transaction_t
*transaction
= NULL
;
523 read_lock(&journal
->j_state_lock
);
524 if (journal
->j_running_transaction
&& !current
->journal_info
) {
525 transaction
= journal
->j_running_transaction
;
526 __jbd2_log_start_commit(journal
, transaction
->t_tid
);
527 } else if (journal
->j_committing_transaction
)
528 transaction
= journal
->j_committing_transaction
;
531 read_unlock(&journal
->j_state_lock
);
532 return 0; /* Nothing to retry */
535 tid
= transaction
->t_tid
;
536 read_unlock(&journal
->j_state_lock
);
537 jbd2_log_wait_commit(journal
, tid
);
542 * Start a commit of the current running transaction (if any). Returns true
543 * if a transaction is going to be committed (or is currently already
544 * committing), and fills its tid in at *ptid
546 int jbd2_journal_start_commit(journal_t
*journal
, tid_t
*ptid
)
550 write_lock(&journal
->j_state_lock
);
551 if (journal
->j_running_transaction
) {
552 tid_t tid
= journal
->j_running_transaction
->t_tid
;
554 __jbd2_log_start_commit(journal
, tid
);
555 /* There's a running transaction and we've just made sure
556 * it's commit has been scheduled. */
560 } else if (journal
->j_committing_transaction
) {
562 * If ext3_write_super() recently started a commit, then we
563 * have to wait for completion of that transaction
566 *ptid
= journal
->j_committing_transaction
->t_tid
;
569 write_unlock(&journal
->j_state_lock
);
574 * Wait for a specified commit to complete.
575 * The caller may not hold the journal lock.
577 int jbd2_log_wait_commit(journal_t
*journal
, tid_t tid
)
581 read_lock(&journal
->j_state_lock
);
582 #ifdef CONFIG_JBD2_DEBUG
583 if (!tid_geq(journal
->j_commit_request
, tid
)) {
585 "%s: error: j_commit_request=%d, tid=%d\n",
586 __func__
, journal
->j_commit_request
, tid
);
589 while (tid_gt(tid
, journal
->j_commit_sequence
)) {
590 jbd_debug(1, "JBD: want %d, j_commit_sequence=%d\n",
591 tid
, journal
->j_commit_sequence
);
592 wake_up(&journal
->j_wait_commit
);
593 read_unlock(&journal
->j_state_lock
);
594 wait_event(journal
->j_wait_done_commit
,
595 !tid_gt(tid
, journal
->j_commit_sequence
));
596 read_lock(&journal
->j_state_lock
);
598 read_unlock(&journal
->j_state_lock
);
600 if (unlikely(is_journal_aborted(journal
))) {
601 printk(KERN_EMERG
"journal commit I/O error\n");
608 * Log buffer allocation routines:
611 int jbd2_journal_next_log_block(journal_t
*journal
, unsigned long long *retp
)
613 unsigned long blocknr
;
615 write_lock(&journal
->j_state_lock
);
616 J_ASSERT(journal
->j_free
> 1);
618 blocknr
= journal
->j_head
;
621 if (journal
->j_head
== journal
->j_last
)
622 journal
->j_head
= journal
->j_first
;
623 write_unlock(&journal
->j_state_lock
);
624 return jbd2_journal_bmap(journal
, blocknr
, retp
);
628 * Conversion of logical to physical block numbers for the journal
630 * On external journals the journal blocks are identity-mapped, so
631 * this is a no-op. If needed, we can use j_blk_offset - everything is
634 int jbd2_journal_bmap(journal_t
*journal
, unsigned long blocknr
,
635 unsigned long long *retp
)
638 unsigned long long ret
;
640 if (journal
->j_inode
) {
641 ret
= bmap(journal
->j_inode
, blocknr
);
645 printk(KERN_ALERT
"%s: journal block not found "
646 "at offset %lu on %s\n",
647 __func__
, blocknr
, journal
->j_devname
);
649 __journal_abort_soft(journal
, err
);
652 *retp
= blocknr
; /* +journal->j_blk_offset */
658 * We play buffer_head aliasing tricks to write data/metadata blocks to
659 * the journal without copying their contents, but for journal
660 * descriptor blocks we do need to generate bona fide buffers.
662 * After the caller of jbd2_journal_get_descriptor_buffer() has finished modifying
663 * the buffer's contents they really should run flush_dcache_page(bh->b_page).
664 * But we don't bother doing that, so there will be coherency problems with
665 * mmaps of blockdevs which hold live JBD-controlled filesystems.
667 struct journal_head
*jbd2_journal_get_descriptor_buffer(journal_t
*journal
)
669 struct buffer_head
*bh
;
670 unsigned long long blocknr
;
673 err
= jbd2_journal_next_log_block(journal
, &blocknr
);
678 bh
= __getblk(journal
->j_dev
, blocknr
, journal
->j_blocksize
);
682 memset(bh
->b_data
, 0, journal
->j_blocksize
);
683 set_buffer_uptodate(bh
);
685 BUFFER_TRACE(bh
, "return this buffer");
686 return jbd2_journal_add_journal_head(bh
);
689 struct jbd2_stats_proc_session
{
691 struct transaction_stats_s
*stats
;
696 static void *jbd2_seq_info_start(struct seq_file
*seq
, loff_t
*pos
)
698 return *pos
? NULL
: SEQ_START_TOKEN
;
701 static void *jbd2_seq_info_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
706 static int jbd2_seq_info_show(struct seq_file
*seq
, void *v
)
708 struct jbd2_stats_proc_session
*s
= seq
->private;
710 if (v
!= SEQ_START_TOKEN
)
712 seq_printf(seq
, "%lu transaction, each up to %u blocks\n",
714 s
->journal
->j_max_transaction_buffers
);
715 if (s
->stats
->ts_tid
== 0)
717 seq_printf(seq
, "average: \n %ums waiting for transaction\n",
718 jiffies_to_msecs(s
->stats
->run
.rs_wait
/ s
->stats
->ts_tid
));
719 seq_printf(seq
, " %ums running transaction\n",
720 jiffies_to_msecs(s
->stats
->run
.rs_running
/ s
->stats
->ts_tid
));
721 seq_printf(seq
, " %ums transaction was being locked\n",
722 jiffies_to_msecs(s
->stats
->run
.rs_locked
/ s
->stats
->ts_tid
));
723 seq_printf(seq
, " %ums flushing data (in ordered mode)\n",
724 jiffies_to_msecs(s
->stats
->run
.rs_flushing
/ s
->stats
->ts_tid
));
725 seq_printf(seq
, " %ums logging transaction\n",
726 jiffies_to_msecs(s
->stats
->run
.rs_logging
/ s
->stats
->ts_tid
));
727 seq_printf(seq
, " %lluus average transaction commit time\n",
728 div_u64(s
->journal
->j_average_commit_time
, 1000));
729 seq_printf(seq
, " %lu handles per transaction\n",
730 s
->stats
->run
.rs_handle_count
/ s
->stats
->ts_tid
);
731 seq_printf(seq
, " %lu blocks per transaction\n",
732 s
->stats
->run
.rs_blocks
/ s
->stats
->ts_tid
);
733 seq_printf(seq
, " %lu logged blocks per transaction\n",
734 s
->stats
->run
.rs_blocks_logged
/ s
->stats
->ts_tid
);
738 static void jbd2_seq_info_stop(struct seq_file
*seq
, void *v
)
742 static const struct seq_operations jbd2_seq_info_ops
= {
743 .start
= jbd2_seq_info_start
,
744 .next
= jbd2_seq_info_next
,
745 .stop
= jbd2_seq_info_stop
,
746 .show
= jbd2_seq_info_show
,
749 static int jbd2_seq_info_open(struct inode
*inode
, struct file
*file
)
751 journal_t
*journal
= PDE(inode
)->data
;
752 struct jbd2_stats_proc_session
*s
;
755 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
758 size
= sizeof(struct transaction_stats_s
);
759 s
->stats
= kmalloc(size
, GFP_KERNEL
);
760 if (s
->stats
== NULL
) {
764 spin_lock(&journal
->j_history_lock
);
765 memcpy(s
->stats
, &journal
->j_stats
, size
);
766 s
->journal
= journal
;
767 spin_unlock(&journal
->j_history_lock
);
769 rc
= seq_open(file
, &jbd2_seq_info_ops
);
771 struct seq_file
*m
= file
->private_data
;
781 static int jbd2_seq_info_release(struct inode
*inode
, struct file
*file
)
783 struct seq_file
*seq
= file
->private_data
;
784 struct jbd2_stats_proc_session
*s
= seq
->private;
787 return seq_release(inode
, file
);
790 static const struct file_operations jbd2_seq_info_fops
= {
791 .owner
= THIS_MODULE
,
792 .open
= jbd2_seq_info_open
,
795 .release
= jbd2_seq_info_release
,
798 static struct proc_dir_entry
*proc_jbd2_stats
;
800 static void jbd2_stats_proc_init(journal_t
*journal
)
802 journal
->j_proc_entry
= proc_mkdir(journal
->j_devname
, proc_jbd2_stats
);
803 if (journal
->j_proc_entry
) {
804 proc_create_data("info", S_IRUGO
, journal
->j_proc_entry
,
805 &jbd2_seq_info_fops
, journal
);
809 static void jbd2_stats_proc_exit(journal_t
*journal
)
811 remove_proc_entry("info", journal
->j_proc_entry
);
812 remove_proc_entry(journal
->j_devname
, proc_jbd2_stats
);
816 * Management for journal control blocks: functions to create and
817 * destroy journal_t structures, and to initialise and read existing
818 * journal blocks from disk. */
820 /* First: create and setup a journal_t object in memory. We initialise
821 * very few fields yet: that has to wait until we have created the
822 * journal structures from from scratch, or loaded them from disk. */
824 static journal_t
* journal_init_common (void)
829 journal
= kzalloc(sizeof(*journal
), GFP_KERNEL
);
833 init_waitqueue_head(&journal
->j_wait_transaction_locked
);
834 init_waitqueue_head(&journal
->j_wait_logspace
);
835 init_waitqueue_head(&journal
->j_wait_done_commit
);
836 init_waitqueue_head(&journal
->j_wait_checkpoint
);
837 init_waitqueue_head(&journal
->j_wait_commit
);
838 init_waitqueue_head(&journal
->j_wait_updates
);
839 mutex_init(&journal
->j_barrier
);
840 mutex_init(&journal
->j_checkpoint_mutex
);
841 spin_lock_init(&journal
->j_revoke_lock
);
842 spin_lock_init(&journal
->j_list_lock
);
843 rwlock_init(&journal
->j_state_lock
);
845 journal
->j_commit_interval
= (HZ
* JBD2_DEFAULT_MAX_COMMIT_AGE
);
846 journal
->j_min_batch_time
= 0;
847 journal
->j_max_batch_time
= 15000; /* 15ms */
849 /* The journal is marked for error until we succeed with recovery! */
850 journal
->j_flags
= JBD2_ABORT
;
852 /* Set up a default-sized revoke table for the new mount. */
853 err
= jbd2_journal_init_revoke(journal
, JOURNAL_REVOKE_DEFAULT_HASH
);
859 spin_lock_init(&journal
->j_history_lock
);
866 /* jbd2_journal_init_dev and jbd2_journal_init_inode:
868 * Create a journal structure assigned some fixed set of disk blocks to
869 * the journal. We don't actually touch those disk blocks yet, but we
870 * need to set up all of the mapping information to tell the journaling
871 * system where the journal blocks are.
876 * journal_t * jbd2_journal_init_dev() - creates and initialises a journal structure
877 * @bdev: Block device on which to create the journal
878 * @fs_dev: Device which hold journalled filesystem for this journal.
879 * @start: Block nr Start of journal.
880 * @len: Length of the journal in blocks.
881 * @blocksize: blocksize of journalling device
883 * Returns: a newly created journal_t *
885 * jbd2_journal_init_dev creates a journal which maps a fixed contiguous
886 * range of blocks on an arbitrary block device.
889 journal_t
* jbd2_journal_init_dev(struct block_device
*bdev
,
890 struct block_device
*fs_dev
,
891 unsigned long long start
, int len
, int blocksize
)
893 journal_t
*journal
= journal_init_common();
894 struct buffer_head
*bh
;
901 /* journal descriptor can store up to n blocks -bzzz */
902 journal
->j_blocksize
= blocksize
;
903 journal
->j_dev
= bdev
;
904 journal
->j_fs_dev
= fs_dev
;
905 journal
->j_blk_offset
= start
;
906 journal
->j_maxlen
= len
;
907 bdevname(journal
->j_dev
, journal
->j_devname
);
908 p
= journal
->j_devname
;
909 while ((p
= strchr(p
, '/')))
911 jbd2_stats_proc_init(journal
);
912 n
= journal
->j_blocksize
/ sizeof(journal_block_tag_t
);
913 journal
->j_wbufsize
= n
;
914 journal
->j_wbuf
= kmalloc(n
* sizeof(struct buffer_head
*), GFP_KERNEL
);
915 if (!journal
->j_wbuf
) {
916 printk(KERN_ERR
"%s: Cant allocate bhs for commit thread\n",
921 bh
= __getblk(journal
->j_dev
, start
, journal
->j_blocksize
);
924 "%s: Cannot get buffer for journal superblock\n",
928 journal
->j_sb_buffer
= bh
;
929 journal
->j_superblock
= (journal_superblock_t
*)bh
->b_data
;
933 kfree(journal
->j_wbuf
);
934 jbd2_stats_proc_exit(journal
);
940 * journal_t * jbd2_journal_init_inode () - creates a journal which maps to a inode.
941 * @inode: An inode to create the journal in
943 * jbd2_journal_init_inode creates a journal which maps an on-disk inode as
944 * the journal. The inode must exist already, must support bmap() and
945 * must have all data blocks preallocated.
947 journal_t
* jbd2_journal_init_inode (struct inode
*inode
)
949 struct buffer_head
*bh
;
950 journal_t
*journal
= journal_init_common();
954 unsigned long long blocknr
;
959 journal
->j_dev
= journal
->j_fs_dev
= inode
->i_sb
->s_bdev
;
960 journal
->j_inode
= inode
;
961 bdevname(journal
->j_dev
, journal
->j_devname
);
962 p
= journal
->j_devname
;
963 while ((p
= strchr(p
, '/')))
965 p
= journal
->j_devname
+ strlen(journal
->j_devname
);
966 sprintf(p
, "-%lu", journal
->j_inode
->i_ino
);
968 "journal %p: inode %s/%ld, size %Ld, bits %d, blksize %ld\n",
969 journal
, inode
->i_sb
->s_id
, inode
->i_ino
,
970 (long long) inode
->i_size
,
971 inode
->i_sb
->s_blocksize_bits
, inode
->i_sb
->s_blocksize
);
973 journal
->j_maxlen
= inode
->i_size
>> inode
->i_sb
->s_blocksize_bits
;
974 journal
->j_blocksize
= inode
->i_sb
->s_blocksize
;
975 jbd2_stats_proc_init(journal
);
977 /* journal descriptor can store up to n blocks -bzzz */
978 n
= journal
->j_blocksize
/ sizeof(journal_block_tag_t
);
979 journal
->j_wbufsize
= n
;
980 journal
->j_wbuf
= kmalloc(n
* sizeof(struct buffer_head
*), GFP_KERNEL
);
981 if (!journal
->j_wbuf
) {
982 printk(KERN_ERR
"%s: Cant allocate bhs for commit thread\n",
987 err
= jbd2_journal_bmap(journal
, 0, &blocknr
);
988 /* If that failed, give up */
990 printk(KERN_ERR
"%s: Cannnot locate journal superblock\n",
995 bh
= __getblk(journal
->j_dev
, blocknr
, journal
->j_blocksize
);
998 "%s: Cannot get buffer for journal superblock\n",
1002 journal
->j_sb_buffer
= bh
;
1003 journal
->j_superblock
= (journal_superblock_t
*)bh
->b_data
;
1007 kfree(journal
->j_wbuf
);
1008 jbd2_stats_proc_exit(journal
);
1014 * If the journal init or create aborts, we need to mark the journal
1015 * superblock as being NULL to prevent the journal destroy from writing
1016 * back a bogus superblock.
1018 static void journal_fail_superblock (journal_t
*journal
)
1020 struct buffer_head
*bh
= journal
->j_sb_buffer
;
1022 journal
->j_sb_buffer
= NULL
;
1026 * Given a journal_t structure, initialise the various fields for
1027 * startup of a new journaling session. We use this both when creating
1028 * a journal, and after recovering an old journal to reset it for
1032 static int journal_reset(journal_t
*journal
)
1034 journal_superblock_t
*sb
= journal
->j_superblock
;
1035 unsigned long long first
, last
;
1037 first
= be32_to_cpu(sb
->s_first
);
1038 last
= be32_to_cpu(sb
->s_maxlen
);
1039 if (first
+ JBD2_MIN_JOURNAL_BLOCKS
> last
+ 1) {
1040 printk(KERN_ERR
"JBD: Journal too short (blocks %llu-%llu).\n",
1042 journal_fail_superblock(journal
);
1046 journal
->j_first
= first
;
1047 journal
->j_last
= last
;
1049 journal
->j_head
= first
;
1050 journal
->j_tail
= first
;
1051 journal
->j_free
= last
- first
;
1053 journal
->j_tail_sequence
= journal
->j_transaction_sequence
;
1054 journal
->j_commit_sequence
= journal
->j_transaction_sequence
- 1;
1055 journal
->j_commit_request
= journal
->j_commit_sequence
;
1057 journal
->j_max_transaction_buffers
= journal
->j_maxlen
/ 4;
1059 /* Add the dynamic fields and write it to disk. */
1060 jbd2_journal_update_superblock(journal
, 1);
1061 return jbd2_journal_start_thread(journal
);
1065 * void jbd2_journal_update_superblock() - Update journal sb on disk.
1066 * @journal: The journal to update.
1067 * @wait: Set to '0' if you don't want to wait for IO completion.
1069 * Update a journal's dynamic superblock fields and write it to disk,
1070 * optionally waiting for the IO to complete.
1072 void jbd2_journal_update_superblock(journal_t
*journal
, int wait
)
1074 journal_superblock_t
*sb
= journal
->j_superblock
;
1075 struct buffer_head
*bh
= journal
->j_sb_buffer
;
1078 * As a special case, if the on-disk copy is already marked as needing
1079 * no recovery (s_start == 0) and there are no outstanding transactions
1080 * in the filesystem, then we can safely defer the superblock update
1081 * until the next commit by setting JBD2_FLUSHED. This avoids
1082 * attempting a write to a potential-readonly device.
1084 if (sb
->s_start
== 0 && journal
->j_tail_sequence
==
1085 journal
->j_transaction_sequence
) {
1086 jbd_debug(1,"JBD: Skipping superblock update on recovered sb "
1087 "(start %ld, seq %d, errno %d)\n",
1088 journal
->j_tail
, journal
->j_tail_sequence
,
1093 if (buffer_write_io_error(bh
)) {
1095 * Oh, dear. A previous attempt to write the journal
1096 * superblock failed. This could happen because the
1097 * USB device was yanked out. Or it could happen to
1098 * be a transient write error and maybe the block will
1099 * be remapped. Nothing we can do but to retry the
1100 * write and hope for the best.
1102 printk(KERN_ERR
"JBD2: previous I/O error detected "
1103 "for journal superblock update for %s.\n",
1104 journal
->j_devname
);
1105 clear_buffer_write_io_error(bh
);
1106 set_buffer_uptodate(bh
);
1109 read_lock(&journal
->j_state_lock
);
1110 jbd_debug(1,"JBD: updating superblock (start %ld, seq %d, errno %d)\n",
1111 journal
->j_tail
, journal
->j_tail_sequence
, journal
->j_errno
);
1113 sb
->s_sequence
= cpu_to_be32(journal
->j_tail_sequence
);
1114 sb
->s_start
= cpu_to_be32(journal
->j_tail
);
1115 sb
->s_errno
= cpu_to_be32(journal
->j_errno
);
1116 read_unlock(&journal
->j_state_lock
);
1118 BUFFER_TRACE(bh
, "marking dirty");
1119 mark_buffer_dirty(bh
);
1121 sync_dirty_buffer(bh
);
1122 if (buffer_write_io_error(bh
)) {
1123 printk(KERN_ERR
"JBD2: I/O error detected "
1124 "when updating journal superblock for %s.\n",
1125 journal
->j_devname
);
1126 clear_buffer_write_io_error(bh
);
1127 set_buffer_uptodate(bh
);
1130 write_dirty_buffer(bh
, WRITE
);
1133 /* If we have just flushed the log (by marking s_start==0), then
1134 * any future commit will have to be careful to update the
1135 * superblock again to re-record the true start of the log. */
1137 write_lock(&journal
->j_state_lock
);
1139 journal
->j_flags
&= ~JBD2_FLUSHED
;
1141 journal
->j_flags
|= JBD2_FLUSHED
;
1142 write_unlock(&journal
->j_state_lock
);
1146 * Read the superblock for a given journal, performing initial
1147 * validation of the format.
1150 static int journal_get_superblock(journal_t
*journal
)
1152 struct buffer_head
*bh
;
1153 journal_superblock_t
*sb
;
1156 bh
= journal
->j_sb_buffer
;
1158 J_ASSERT(bh
!= NULL
);
1159 if (!buffer_uptodate(bh
)) {
1160 ll_rw_block(READ
, 1, &bh
);
1162 if (!buffer_uptodate(bh
)) {
1164 "JBD: IO error reading journal superblock\n");
1169 sb
= journal
->j_superblock
;
1173 if (sb
->s_header
.h_magic
!= cpu_to_be32(JBD2_MAGIC_NUMBER
) ||
1174 sb
->s_blocksize
!= cpu_to_be32(journal
->j_blocksize
)) {
1175 printk(KERN_WARNING
"JBD: no valid journal superblock found\n");
1179 switch(be32_to_cpu(sb
->s_header
.h_blocktype
)) {
1180 case JBD2_SUPERBLOCK_V1
:
1181 journal
->j_format_version
= 1;
1183 case JBD2_SUPERBLOCK_V2
:
1184 journal
->j_format_version
= 2;
1187 printk(KERN_WARNING
"JBD: unrecognised superblock format ID\n");
1191 if (be32_to_cpu(sb
->s_maxlen
) < journal
->j_maxlen
)
1192 journal
->j_maxlen
= be32_to_cpu(sb
->s_maxlen
);
1193 else if (be32_to_cpu(sb
->s_maxlen
) > journal
->j_maxlen
) {
1194 printk (KERN_WARNING
"JBD: journal file too short\n");
1201 journal_fail_superblock(journal
);
1206 * Load the on-disk journal superblock and read the key fields into the
1210 static int load_superblock(journal_t
*journal
)
1213 journal_superblock_t
*sb
;
1215 err
= journal_get_superblock(journal
);
1219 sb
= journal
->j_superblock
;
1221 journal
->j_tail_sequence
= be32_to_cpu(sb
->s_sequence
);
1222 journal
->j_tail
= be32_to_cpu(sb
->s_start
);
1223 journal
->j_first
= be32_to_cpu(sb
->s_first
);
1224 journal
->j_last
= be32_to_cpu(sb
->s_maxlen
);
1225 journal
->j_errno
= be32_to_cpu(sb
->s_errno
);
1232 * int jbd2_journal_load() - Read journal from disk.
1233 * @journal: Journal to act on.
1235 * Given a journal_t structure which tells us which disk blocks contain
1236 * a journal, read the journal from disk to initialise the in-memory
1239 int jbd2_journal_load(journal_t
*journal
)
1242 journal_superblock_t
*sb
;
1244 err
= load_superblock(journal
);
1248 sb
= journal
->j_superblock
;
1249 /* If this is a V2 superblock, then we have to check the
1250 * features flags on it. */
1252 if (journal
->j_format_version
>= 2) {
1253 if ((sb
->s_feature_ro_compat
&
1254 ~cpu_to_be32(JBD2_KNOWN_ROCOMPAT_FEATURES
)) ||
1255 (sb
->s_feature_incompat
&
1256 ~cpu_to_be32(JBD2_KNOWN_INCOMPAT_FEATURES
))) {
1257 printk (KERN_WARNING
1258 "JBD: Unrecognised features on journal\n");
1264 * Create a slab for this blocksize
1266 err
= jbd2_journal_create_slab(be32_to_cpu(sb
->s_blocksize
));
1270 /* Let the recovery code check whether it needs to recover any
1271 * data from the journal. */
1272 if (jbd2_journal_recover(journal
))
1273 goto recovery_error
;
1275 if (journal
->j_failed_commit
) {
1276 printk(KERN_ERR
"JBD2: journal transaction %u on %s "
1277 "is corrupt.\n", journal
->j_failed_commit
,
1278 journal
->j_devname
);
1282 /* OK, we've finished with the dynamic journal bits:
1283 * reinitialise the dynamic contents of the superblock in memory
1284 * and reset them on disk. */
1285 if (journal_reset(journal
))
1286 goto recovery_error
;
1288 journal
->j_flags
&= ~JBD2_ABORT
;
1289 journal
->j_flags
|= JBD2_LOADED
;
1293 printk (KERN_WARNING
"JBD: recovery failed\n");
1298 * void jbd2_journal_destroy() - Release a journal_t structure.
1299 * @journal: Journal to act on.
1301 * Release a journal_t structure once it is no longer in use by the
1303 * Return <0 if we couldn't clean up the journal.
1305 int jbd2_journal_destroy(journal_t
*journal
)
1309 /* Wait for the commit thread to wake up and die. */
1310 journal_kill_thread(journal
);
1312 /* Force a final log commit */
1313 if (journal
->j_running_transaction
)
1314 jbd2_journal_commit_transaction(journal
);
1316 /* Force any old transactions to disk */
1318 /* Totally anal locking here... */
1319 spin_lock(&journal
->j_list_lock
);
1320 while (journal
->j_checkpoint_transactions
!= NULL
) {
1321 spin_unlock(&journal
->j_list_lock
);
1322 mutex_lock(&journal
->j_checkpoint_mutex
);
1323 jbd2_log_do_checkpoint(journal
);
1324 mutex_unlock(&journal
->j_checkpoint_mutex
);
1325 spin_lock(&journal
->j_list_lock
);
1328 J_ASSERT(journal
->j_running_transaction
== NULL
);
1329 J_ASSERT(journal
->j_committing_transaction
== NULL
);
1330 J_ASSERT(journal
->j_checkpoint_transactions
== NULL
);
1331 spin_unlock(&journal
->j_list_lock
);
1333 if (journal
->j_sb_buffer
) {
1334 if (!is_journal_aborted(journal
)) {
1335 /* We can now mark the journal as empty. */
1336 journal
->j_tail
= 0;
1337 journal
->j_tail_sequence
=
1338 ++journal
->j_transaction_sequence
;
1339 jbd2_journal_update_superblock(journal
, 1);
1343 brelse(journal
->j_sb_buffer
);
1346 if (journal
->j_proc_entry
)
1347 jbd2_stats_proc_exit(journal
);
1348 if (journal
->j_inode
)
1349 iput(journal
->j_inode
);
1350 if (journal
->j_revoke
)
1351 jbd2_journal_destroy_revoke(journal
);
1352 kfree(journal
->j_wbuf
);
1360 *int jbd2_journal_check_used_features () - Check if features specified are used.
1361 * @journal: Journal to check.
1362 * @compat: bitmask of compatible features
1363 * @ro: bitmask of features that force read-only mount
1364 * @incompat: bitmask of incompatible features
1366 * Check whether the journal uses all of a given set of
1367 * features. Return true (non-zero) if it does.
1370 int jbd2_journal_check_used_features (journal_t
*journal
, unsigned long compat
,
1371 unsigned long ro
, unsigned long incompat
)
1373 journal_superblock_t
*sb
;
1375 if (!compat
&& !ro
&& !incompat
)
1377 /* Load journal superblock if it is not loaded yet. */
1378 if (journal
->j_format_version
== 0 &&
1379 journal_get_superblock(journal
) != 0)
1381 if (journal
->j_format_version
== 1)
1384 sb
= journal
->j_superblock
;
1386 if (((be32_to_cpu(sb
->s_feature_compat
) & compat
) == compat
) &&
1387 ((be32_to_cpu(sb
->s_feature_ro_compat
) & ro
) == ro
) &&
1388 ((be32_to_cpu(sb
->s_feature_incompat
) & incompat
) == incompat
))
1395 * int jbd2_journal_check_available_features() - Check feature set in journalling layer
1396 * @journal: Journal to check.
1397 * @compat: bitmask of compatible features
1398 * @ro: bitmask of features that force read-only mount
1399 * @incompat: bitmask of incompatible features
1401 * Check whether the journaling code supports the use of
1402 * all of a given set of features on this journal. Return true
1403 * (non-zero) if it can. */
1405 int jbd2_journal_check_available_features (journal_t
*journal
, unsigned long compat
,
1406 unsigned long ro
, unsigned long incompat
)
1408 if (!compat
&& !ro
&& !incompat
)
1411 /* We can support any known requested features iff the
1412 * superblock is in version 2. Otherwise we fail to support any
1413 * extended sb features. */
1415 if (journal
->j_format_version
!= 2)
1418 if ((compat
& JBD2_KNOWN_COMPAT_FEATURES
) == compat
&&
1419 (ro
& JBD2_KNOWN_ROCOMPAT_FEATURES
) == ro
&&
1420 (incompat
& JBD2_KNOWN_INCOMPAT_FEATURES
) == incompat
)
1427 * int jbd2_journal_set_features () - Mark a given journal feature in the superblock
1428 * @journal: Journal to act on.
1429 * @compat: bitmask of compatible features
1430 * @ro: bitmask of features that force read-only mount
1431 * @incompat: bitmask of incompatible features
1433 * Mark a given journal feature as present on the
1434 * superblock. Returns true if the requested features could be set.
1438 int jbd2_journal_set_features (journal_t
*journal
, unsigned long compat
,
1439 unsigned long ro
, unsigned long incompat
)
1441 journal_superblock_t
*sb
;
1443 if (jbd2_journal_check_used_features(journal
, compat
, ro
, incompat
))
1446 if (!jbd2_journal_check_available_features(journal
, compat
, ro
, incompat
))
1449 jbd_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n",
1450 compat
, ro
, incompat
);
1452 sb
= journal
->j_superblock
;
1454 sb
->s_feature_compat
|= cpu_to_be32(compat
);
1455 sb
->s_feature_ro_compat
|= cpu_to_be32(ro
);
1456 sb
->s_feature_incompat
|= cpu_to_be32(incompat
);
1462 * jbd2_journal_clear_features () - Clear a given journal feature in the
1464 * @journal: Journal to act on.
1465 * @compat: bitmask of compatible features
1466 * @ro: bitmask of features that force read-only mount
1467 * @incompat: bitmask of incompatible features
1469 * Clear a given journal feature as present on the
1472 void jbd2_journal_clear_features(journal_t
*journal
, unsigned long compat
,
1473 unsigned long ro
, unsigned long incompat
)
1475 journal_superblock_t
*sb
;
1477 jbd_debug(1, "Clear features 0x%lx/0x%lx/0x%lx\n",
1478 compat
, ro
, incompat
);
1480 sb
= journal
->j_superblock
;
1482 sb
->s_feature_compat
&= ~cpu_to_be32(compat
);
1483 sb
->s_feature_ro_compat
&= ~cpu_to_be32(ro
);
1484 sb
->s_feature_incompat
&= ~cpu_to_be32(incompat
);
1486 EXPORT_SYMBOL(jbd2_journal_clear_features
);
1489 * int jbd2_journal_update_format () - Update on-disk journal structure.
1490 * @journal: Journal to act on.
1492 * Given an initialised but unloaded journal struct, poke about in the
1493 * on-disk structure to update it to the most recent supported version.
1495 int jbd2_journal_update_format (journal_t
*journal
)
1497 journal_superblock_t
*sb
;
1500 err
= journal_get_superblock(journal
);
1504 sb
= journal
->j_superblock
;
1506 switch (be32_to_cpu(sb
->s_header
.h_blocktype
)) {
1507 case JBD2_SUPERBLOCK_V2
:
1509 case JBD2_SUPERBLOCK_V1
:
1510 return journal_convert_superblock_v1(journal
, sb
);
1517 static int journal_convert_superblock_v1(journal_t
*journal
,
1518 journal_superblock_t
*sb
)
1520 int offset
, blocksize
;
1521 struct buffer_head
*bh
;
1524 "JBD: Converting superblock from version 1 to 2.\n");
1526 /* Pre-initialise new fields to zero */
1527 offset
= ((char *) &(sb
->s_feature_compat
)) - ((char *) sb
);
1528 blocksize
= be32_to_cpu(sb
->s_blocksize
);
1529 memset(&sb
->s_feature_compat
, 0, blocksize
-offset
);
1531 sb
->s_nr_users
= cpu_to_be32(1);
1532 sb
->s_header
.h_blocktype
= cpu_to_be32(JBD2_SUPERBLOCK_V2
);
1533 journal
->j_format_version
= 2;
1535 bh
= journal
->j_sb_buffer
;
1536 BUFFER_TRACE(bh
, "marking dirty");
1537 mark_buffer_dirty(bh
);
1538 sync_dirty_buffer(bh
);
1544 * int jbd2_journal_flush () - Flush journal
1545 * @journal: Journal to act on.
1547 * Flush all data for a given journal to disk and empty the journal.
1548 * Filesystems can use this when remounting readonly to ensure that
1549 * recovery does not need to happen on remount.
1552 int jbd2_journal_flush(journal_t
*journal
)
1555 transaction_t
*transaction
= NULL
;
1556 unsigned long old_tail
;
1558 write_lock(&journal
->j_state_lock
);
1560 /* Force everything buffered to the log... */
1561 if (journal
->j_running_transaction
) {
1562 transaction
= journal
->j_running_transaction
;
1563 __jbd2_log_start_commit(journal
, transaction
->t_tid
);
1564 } else if (journal
->j_committing_transaction
)
1565 transaction
= journal
->j_committing_transaction
;
1567 /* Wait for the log commit to complete... */
1569 tid_t tid
= transaction
->t_tid
;
1571 write_unlock(&journal
->j_state_lock
);
1572 jbd2_log_wait_commit(journal
, tid
);
1574 write_unlock(&journal
->j_state_lock
);
1577 /* ...and flush everything in the log out to disk. */
1578 spin_lock(&journal
->j_list_lock
);
1579 while (!err
&& journal
->j_checkpoint_transactions
!= NULL
) {
1580 spin_unlock(&journal
->j_list_lock
);
1581 mutex_lock(&journal
->j_checkpoint_mutex
);
1582 err
= jbd2_log_do_checkpoint(journal
);
1583 mutex_unlock(&journal
->j_checkpoint_mutex
);
1584 spin_lock(&journal
->j_list_lock
);
1586 spin_unlock(&journal
->j_list_lock
);
1588 if (is_journal_aborted(journal
))
1591 jbd2_cleanup_journal_tail(journal
);
1593 /* Finally, mark the journal as really needing no recovery.
1594 * This sets s_start==0 in the underlying superblock, which is
1595 * the magic code for a fully-recovered superblock. Any future
1596 * commits of data to the journal will restore the current
1598 write_lock(&journal
->j_state_lock
);
1599 old_tail
= journal
->j_tail
;
1600 journal
->j_tail
= 0;
1601 write_unlock(&journal
->j_state_lock
);
1602 jbd2_journal_update_superblock(journal
, 1);
1603 write_lock(&journal
->j_state_lock
);
1604 journal
->j_tail
= old_tail
;
1606 J_ASSERT(!journal
->j_running_transaction
);
1607 J_ASSERT(!journal
->j_committing_transaction
);
1608 J_ASSERT(!journal
->j_checkpoint_transactions
);
1609 J_ASSERT(journal
->j_head
== journal
->j_tail
);
1610 J_ASSERT(journal
->j_tail_sequence
== journal
->j_transaction_sequence
);
1611 write_unlock(&journal
->j_state_lock
);
1616 * int jbd2_journal_wipe() - Wipe journal contents
1617 * @journal: Journal to act on.
1618 * @write: flag (see below)
1620 * Wipe out all of the contents of a journal, safely. This will produce
1621 * a warning if the journal contains any valid recovery information.
1622 * Must be called between journal_init_*() and jbd2_journal_load().
1624 * If 'write' is non-zero, then we wipe out the journal on disk; otherwise
1625 * we merely suppress recovery.
1628 int jbd2_journal_wipe(journal_t
*journal
, int write
)
1632 J_ASSERT (!(journal
->j_flags
& JBD2_LOADED
));
1634 err
= load_superblock(journal
);
1638 if (!journal
->j_tail
)
1641 printk (KERN_WARNING
"JBD: %s recovery information on journal\n",
1642 write
? "Clearing" : "Ignoring");
1644 err
= jbd2_journal_skip_recovery(journal
);
1646 jbd2_journal_update_superblock(journal
, 1);
1653 * Journal abort has very specific semantics, which we describe
1654 * for journal abort.
1656 * Two internal functions, which provide abort to the jbd layer
1661 * Quick version for internal journal use (doesn't lock the journal).
1662 * Aborts hard --- we mark the abort as occurred, but do _nothing_ else,
1663 * and don't attempt to make any other journal updates.
1665 void __jbd2_journal_abort_hard(journal_t
*journal
)
1667 transaction_t
*transaction
;
1669 if (journal
->j_flags
& JBD2_ABORT
)
1672 printk(KERN_ERR
"Aborting journal on device %s.\n",
1673 journal
->j_devname
);
1675 write_lock(&journal
->j_state_lock
);
1676 journal
->j_flags
|= JBD2_ABORT
;
1677 transaction
= journal
->j_running_transaction
;
1679 __jbd2_log_start_commit(journal
, transaction
->t_tid
);
1680 write_unlock(&journal
->j_state_lock
);
1683 /* Soft abort: record the abort error status in the journal superblock,
1684 * but don't do any other IO. */
1685 static void __journal_abort_soft (journal_t
*journal
, int errno
)
1687 if (journal
->j_flags
& JBD2_ABORT
)
1690 if (!journal
->j_errno
)
1691 journal
->j_errno
= errno
;
1693 __jbd2_journal_abort_hard(journal
);
1696 jbd2_journal_update_superblock(journal
, 1);
1700 * void jbd2_journal_abort () - Shutdown the journal immediately.
1701 * @journal: the journal to shutdown.
1702 * @errno: an error number to record in the journal indicating
1703 * the reason for the shutdown.
1705 * Perform a complete, immediate shutdown of the ENTIRE
1706 * journal (not of a single transaction). This operation cannot be
1707 * undone without closing and reopening the journal.
1709 * The jbd2_journal_abort function is intended to support higher level error
1710 * recovery mechanisms such as the ext2/ext3 remount-readonly error
1713 * Journal abort has very specific semantics. Any existing dirty,
1714 * unjournaled buffers in the main filesystem will still be written to
1715 * disk by bdflush, but the journaling mechanism will be suspended
1716 * immediately and no further transaction commits will be honoured.
1718 * Any dirty, journaled buffers will be written back to disk without
1719 * hitting the journal. Atomicity cannot be guaranteed on an aborted
1720 * filesystem, but we _do_ attempt to leave as much data as possible
1721 * behind for fsck to use for cleanup.
1723 * Any attempt to get a new transaction handle on a journal which is in
1724 * ABORT state will just result in an -EROFS error return. A
1725 * jbd2_journal_stop on an existing handle will return -EIO if we have
1726 * entered abort state during the update.
1728 * Recursive transactions are not disturbed by journal abort until the
1729 * final jbd2_journal_stop, which will receive the -EIO error.
1731 * Finally, the jbd2_journal_abort call allows the caller to supply an errno
1732 * which will be recorded (if possible) in the journal superblock. This
1733 * allows a client to record failure conditions in the middle of a
1734 * transaction without having to complete the transaction to record the
1735 * failure to disk. ext3_error, for example, now uses this
1738 * Errors which originate from within the journaling layer will NOT
1739 * supply an errno; a null errno implies that absolutely no further
1740 * writes are done to the journal (unless there are any already in
1745 void jbd2_journal_abort(journal_t
*journal
, int errno
)
1747 __journal_abort_soft(journal
, errno
);
1751 * int jbd2_journal_errno () - returns the journal's error state.
1752 * @journal: journal to examine.
1754 * This is the errno number set with jbd2_journal_abort(), the last
1755 * time the journal was mounted - if the journal was stopped
1756 * without calling abort this will be 0.
1758 * If the journal has been aborted on this mount time -EROFS will
1761 int jbd2_journal_errno(journal_t
*journal
)
1765 read_lock(&journal
->j_state_lock
);
1766 if (journal
->j_flags
& JBD2_ABORT
)
1769 err
= journal
->j_errno
;
1770 read_unlock(&journal
->j_state_lock
);
1775 * int jbd2_journal_clear_err () - clears the journal's error state
1776 * @journal: journal to act on.
1778 * An error must be cleared or acked to take a FS out of readonly
1781 int jbd2_journal_clear_err(journal_t
*journal
)
1785 write_lock(&journal
->j_state_lock
);
1786 if (journal
->j_flags
& JBD2_ABORT
)
1789 journal
->j_errno
= 0;
1790 write_unlock(&journal
->j_state_lock
);
1795 * void jbd2_journal_ack_err() - Ack journal err.
1796 * @journal: journal to act on.
1798 * An error must be cleared or acked to take a FS out of readonly
1801 void jbd2_journal_ack_err(journal_t
*journal
)
1803 write_lock(&journal
->j_state_lock
);
1804 if (journal
->j_errno
)
1805 journal
->j_flags
|= JBD2_ACK_ERR
;
1806 write_unlock(&journal
->j_state_lock
);
1809 int jbd2_journal_blocks_per_page(struct inode
*inode
)
1811 return 1 << (PAGE_CACHE_SHIFT
- inode
->i_sb
->s_blocksize_bits
);
1815 * helper functions to deal with 32 or 64bit block numbers.
1817 size_t journal_tag_bytes(journal_t
*journal
)
1819 if (JBD2_HAS_INCOMPAT_FEATURE(journal
, JBD2_FEATURE_INCOMPAT_64BIT
))
1820 return JBD2_TAG_SIZE64
;
1822 return JBD2_TAG_SIZE32
;
1826 * JBD memory management
1828 * These functions are used to allocate block-sized chunks of memory
1829 * used for making copies of buffer_head data. Very often it will be
1830 * page-sized chunks of data, but sometimes it will be in
1831 * sub-page-size chunks. (For example, 16k pages on Power systems
1832 * with a 4k block file system.) For blocks smaller than a page, we
1833 * use a SLAB allocator. There are slab caches for each block size,
1834 * which are allocated at mount time, if necessary, and we only free
1835 * (all of) the slab caches when/if the jbd2 module is unloaded. For
1836 * this reason we don't need to a mutex to protect access to
1837 * jbd2_slab[] allocating or releasing memory; only in
1838 * jbd2_journal_create_slab().
1840 #define JBD2_MAX_SLABS 8
1841 static struct kmem_cache
*jbd2_slab
[JBD2_MAX_SLABS
];
1843 static const char *jbd2_slab_names
[JBD2_MAX_SLABS
] = {
1844 "jbd2_1k", "jbd2_2k", "jbd2_4k", "jbd2_8k",
1845 "jbd2_16k", "jbd2_32k", "jbd2_64k", "jbd2_128k"
1849 static void jbd2_journal_destroy_slabs(void)
1853 for (i
= 0; i
< JBD2_MAX_SLABS
; i
++) {
1855 kmem_cache_destroy(jbd2_slab
[i
]);
1856 jbd2_slab
[i
] = NULL
;
1860 static int jbd2_journal_create_slab(size_t size
)
1862 static DEFINE_MUTEX(jbd2_slab_create_mutex
);
1863 int i
= order_base_2(size
) - 10;
1866 if (size
== PAGE_SIZE
)
1869 if (i
>= JBD2_MAX_SLABS
)
1872 if (unlikely(i
< 0))
1874 mutex_lock(&jbd2_slab_create_mutex
);
1876 mutex_unlock(&jbd2_slab_create_mutex
);
1877 return 0; /* Already created */
1880 slab_size
= 1 << (i
+10);
1881 jbd2_slab
[i
] = kmem_cache_create(jbd2_slab_names
[i
], slab_size
,
1882 slab_size
, 0, NULL
);
1883 mutex_unlock(&jbd2_slab_create_mutex
);
1884 if (!jbd2_slab
[i
]) {
1885 printk(KERN_EMERG
"JBD2: no memory for jbd2_slab cache\n");
1891 static struct kmem_cache
*get_slab(size_t size
)
1893 int i
= order_base_2(size
) - 10;
1895 BUG_ON(i
>= JBD2_MAX_SLABS
);
1896 if (unlikely(i
< 0))
1898 BUG_ON(jbd2_slab
[i
] == NULL
);
1899 return jbd2_slab
[i
];
1902 void *jbd2_alloc(size_t size
, gfp_t flags
)
1906 BUG_ON(size
& (size
-1)); /* Must be a power of 2 */
1908 flags
|= __GFP_REPEAT
;
1909 if (size
== PAGE_SIZE
)
1910 ptr
= (void *)__get_free_pages(flags
, 0);
1911 else if (size
> PAGE_SIZE
) {
1912 int order
= get_order(size
);
1915 ptr
= (void *)__get_free_pages(flags
, order
);
1917 ptr
= vmalloc(size
);
1919 ptr
= kmem_cache_alloc(get_slab(size
), flags
);
1921 /* Check alignment; SLUB has gotten this wrong in the past,
1922 * and this can lead to user data corruption! */
1923 BUG_ON(((unsigned long) ptr
) & (size
-1));
1928 void jbd2_free(void *ptr
, size_t size
)
1930 if (size
== PAGE_SIZE
) {
1931 free_pages((unsigned long)ptr
, 0);
1934 if (size
> PAGE_SIZE
) {
1935 int order
= get_order(size
);
1938 free_pages((unsigned long)ptr
, order
);
1943 kmem_cache_free(get_slab(size
), ptr
);
1947 * Journal_head storage management
1949 static struct kmem_cache
*jbd2_journal_head_cache
;
1950 #ifdef CONFIG_JBD2_DEBUG
1951 static atomic_t nr_journal_heads
= ATOMIC_INIT(0);
1954 static int journal_init_jbd2_journal_head_cache(void)
1958 J_ASSERT(jbd2_journal_head_cache
== NULL
);
1959 jbd2_journal_head_cache
= kmem_cache_create("jbd2_journal_head",
1960 sizeof(struct journal_head
),
1962 SLAB_TEMPORARY
, /* flags */
1965 if (!jbd2_journal_head_cache
) {
1967 printk(KERN_EMERG
"JBD: no memory for journal_head cache\n");
1972 static void jbd2_journal_destroy_jbd2_journal_head_cache(void)
1974 if (jbd2_journal_head_cache
) {
1975 kmem_cache_destroy(jbd2_journal_head_cache
);
1976 jbd2_journal_head_cache
= NULL
;
1981 * journal_head splicing and dicing
1983 static struct journal_head
*journal_alloc_journal_head(void)
1985 struct journal_head
*ret
;
1987 #ifdef CONFIG_JBD2_DEBUG
1988 atomic_inc(&nr_journal_heads
);
1990 ret
= kmem_cache_alloc(jbd2_journal_head_cache
, GFP_NOFS
);
1992 jbd_debug(1, "out of memory for journal_head\n");
1993 pr_notice_ratelimited("ENOMEM in %s, retrying.\n", __func__
);
1996 ret
= kmem_cache_alloc(jbd2_journal_head_cache
, GFP_NOFS
);
2002 static void journal_free_journal_head(struct journal_head
*jh
)
2004 #ifdef CONFIG_JBD2_DEBUG
2005 atomic_dec(&nr_journal_heads
);
2006 memset(jh
, JBD2_POISON_FREE
, sizeof(*jh
));
2008 kmem_cache_free(jbd2_journal_head_cache
, jh
);
2012 * A journal_head is attached to a buffer_head whenever JBD has an
2013 * interest in the buffer.
2015 * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit
2016 * is set. This bit is tested in core kernel code where we need to take
2017 * JBD-specific actions. Testing the zeroness of ->b_private is not reliable
2020 * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one.
2022 * When a buffer has its BH_JBD bit set it is immune from being released by
2023 * core kernel code, mainly via ->b_count.
2025 * A journal_head may be detached from its buffer_head when the journal_head's
2026 * b_transaction, b_cp_transaction and b_next_transaction pointers are NULL.
2027 * Various places in JBD call jbd2_journal_remove_journal_head() to indicate that the
2028 * journal_head can be dropped if needed.
2030 * Various places in the kernel want to attach a journal_head to a buffer_head
2031 * _before_ attaching the journal_head to a transaction. To protect the
2032 * journal_head in this situation, jbd2_journal_add_journal_head elevates the
2033 * journal_head's b_jcount refcount by one. The caller must call
2034 * jbd2_journal_put_journal_head() to undo this.
2036 * So the typical usage would be:
2038 * (Attach a journal_head if needed. Increments b_jcount)
2039 * struct journal_head *jh = jbd2_journal_add_journal_head(bh);
2041 * jh->b_transaction = xxx;
2042 * jbd2_journal_put_journal_head(jh);
2044 * Now, the journal_head's b_jcount is zero, but it is safe from being released
2045 * because it has a non-zero b_transaction.
2049 * Give a buffer_head a journal_head.
2051 * Doesn't need the journal lock.
2054 struct journal_head
*jbd2_journal_add_journal_head(struct buffer_head
*bh
)
2056 struct journal_head
*jh
;
2057 struct journal_head
*new_jh
= NULL
;
2060 if (!buffer_jbd(bh
)) {
2061 new_jh
= journal_alloc_journal_head();
2062 memset(new_jh
, 0, sizeof(*new_jh
));
2065 jbd_lock_bh_journal_head(bh
);
2066 if (buffer_jbd(bh
)) {
2070 (atomic_read(&bh
->b_count
) > 0) ||
2071 (bh
->b_page
&& bh
->b_page
->mapping
));
2074 jbd_unlock_bh_journal_head(bh
);
2079 new_jh
= NULL
; /* We consumed it */
2084 BUFFER_TRACE(bh
, "added journal_head");
2087 jbd_unlock_bh_journal_head(bh
);
2089 journal_free_journal_head(new_jh
);
2090 return bh
->b_private
;
2094 * Grab a ref against this buffer_head's journal_head. If it ended up not
2095 * having a journal_head, return NULL
2097 struct journal_head
*jbd2_journal_grab_journal_head(struct buffer_head
*bh
)
2099 struct journal_head
*jh
= NULL
;
2101 jbd_lock_bh_journal_head(bh
);
2102 if (buffer_jbd(bh
)) {
2106 jbd_unlock_bh_journal_head(bh
);
2110 static void __journal_remove_journal_head(struct buffer_head
*bh
)
2112 struct journal_head
*jh
= bh2jh(bh
);
2114 J_ASSERT_JH(jh
, jh
->b_jcount
>= 0);
2117 if (jh
->b_jcount
== 0) {
2118 if (jh
->b_transaction
== NULL
&&
2119 jh
->b_next_transaction
== NULL
&&
2120 jh
->b_cp_transaction
== NULL
) {
2121 J_ASSERT_JH(jh
, jh
->b_jlist
== BJ_None
);
2122 J_ASSERT_BH(bh
, buffer_jbd(bh
));
2123 J_ASSERT_BH(bh
, jh2bh(jh
) == bh
);
2124 BUFFER_TRACE(bh
, "remove journal_head");
2125 if (jh
->b_frozen_data
) {
2126 printk(KERN_WARNING
"%s: freeing "
2129 jbd2_free(jh
->b_frozen_data
, bh
->b_size
);
2131 if (jh
->b_committed_data
) {
2132 printk(KERN_WARNING
"%s: freeing "
2133 "b_committed_data\n",
2135 jbd2_free(jh
->b_committed_data
, bh
->b_size
);
2137 bh
->b_private
= NULL
;
2138 jh
->b_bh
= NULL
; /* debug, really */
2139 clear_buffer_jbd(bh
);
2141 journal_free_journal_head(jh
);
2143 BUFFER_TRACE(bh
, "journal_head was locked");
2149 * jbd2_journal_remove_journal_head(): if the buffer isn't attached to a transaction
2150 * and has a zero b_jcount then remove and release its journal_head. If we did
2151 * see that the buffer is not used by any transaction we also "logically"
2152 * decrement ->b_count.
2154 * We in fact take an additional increment on ->b_count as a convenience,
2155 * because the caller usually wants to do additional things with the bh
2156 * after calling here.
2157 * The caller of jbd2_journal_remove_journal_head() *must* run __brelse(bh) at some
2158 * time. Once the caller has run __brelse(), the buffer is eligible for
2159 * reaping by try_to_free_buffers().
2161 void jbd2_journal_remove_journal_head(struct buffer_head
*bh
)
2163 jbd_lock_bh_journal_head(bh
);
2164 __journal_remove_journal_head(bh
);
2165 jbd_unlock_bh_journal_head(bh
);
2169 * Drop a reference on the passed journal_head. If it fell to zero then try to
2170 * release the journal_head from the buffer_head.
2172 void jbd2_journal_put_journal_head(struct journal_head
*jh
)
2174 struct buffer_head
*bh
= jh2bh(jh
);
2176 jbd_lock_bh_journal_head(bh
);
2177 J_ASSERT_JH(jh
, jh
->b_jcount
> 0);
2179 if (!jh
->b_jcount
&& !jh
->b_transaction
) {
2180 __journal_remove_journal_head(bh
);
2183 jbd_unlock_bh_journal_head(bh
);
2187 * Initialize jbd inode head
2189 void jbd2_journal_init_jbd_inode(struct jbd2_inode
*jinode
, struct inode
*inode
)
2191 jinode
->i_transaction
= NULL
;
2192 jinode
->i_next_transaction
= NULL
;
2193 jinode
->i_vfs_inode
= inode
;
2194 jinode
->i_flags
= 0;
2195 INIT_LIST_HEAD(&jinode
->i_list
);
2199 * Function to be called before we start removing inode from memory (i.e.,
2200 * clear_inode() is a fine place to be called from). It removes inode from
2201 * transaction's lists.
2203 void jbd2_journal_release_jbd_inode(journal_t
*journal
,
2204 struct jbd2_inode
*jinode
)
2209 spin_lock(&journal
->j_list_lock
);
2210 /* Is commit writing out inode - we have to wait */
2211 if (test_bit(__JI_COMMIT_RUNNING
, &jinode
->i_flags
)) {
2212 wait_queue_head_t
*wq
;
2213 DEFINE_WAIT_BIT(wait
, &jinode
->i_flags
, __JI_COMMIT_RUNNING
);
2214 wq
= bit_waitqueue(&jinode
->i_flags
, __JI_COMMIT_RUNNING
);
2215 prepare_to_wait(wq
, &wait
.wait
, TASK_UNINTERRUPTIBLE
);
2216 spin_unlock(&journal
->j_list_lock
);
2218 finish_wait(wq
, &wait
.wait
);
2222 if (jinode
->i_transaction
) {
2223 list_del(&jinode
->i_list
);
2224 jinode
->i_transaction
= NULL
;
2226 spin_unlock(&journal
->j_list_lock
);
2232 #ifdef CONFIG_JBD2_DEBUG
2233 u8 jbd2_journal_enable_debug __read_mostly
;
2234 EXPORT_SYMBOL(jbd2_journal_enable_debug
);
2236 #define JBD2_DEBUG_NAME "jbd2-debug"
2238 static struct dentry
*jbd2_debugfs_dir
;
2239 static struct dentry
*jbd2_debug
;
2241 static void __init
jbd2_create_debugfs_entry(void)
2243 jbd2_debugfs_dir
= debugfs_create_dir("jbd2", NULL
);
2244 if (jbd2_debugfs_dir
)
2245 jbd2_debug
= debugfs_create_u8(JBD2_DEBUG_NAME
,
2248 &jbd2_journal_enable_debug
);
2251 static void __exit
jbd2_remove_debugfs_entry(void)
2253 debugfs_remove(jbd2_debug
);
2254 debugfs_remove(jbd2_debugfs_dir
);
2259 static void __init
jbd2_create_debugfs_entry(void)
2263 static void __exit
jbd2_remove_debugfs_entry(void)
2269 #ifdef CONFIG_PROC_FS
2271 #define JBD2_STATS_PROC_NAME "fs/jbd2"
2273 static void __init
jbd2_create_jbd_stats_proc_entry(void)
2275 proc_jbd2_stats
= proc_mkdir(JBD2_STATS_PROC_NAME
, NULL
);
2278 static void __exit
jbd2_remove_jbd_stats_proc_entry(void)
2280 if (proc_jbd2_stats
)
2281 remove_proc_entry(JBD2_STATS_PROC_NAME
, NULL
);
2286 #define jbd2_create_jbd_stats_proc_entry() do {} while (0)
2287 #define jbd2_remove_jbd_stats_proc_entry() do {} while (0)
2291 struct kmem_cache
*jbd2_handle_cache
;
2293 static int __init
journal_init_handle_cache(void)
2295 jbd2_handle_cache
= kmem_cache_create("jbd2_journal_handle",
2298 SLAB_TEMPORARY
, /* flags */
2300 if (jbd2_handle_cache
== NULL
) {
2301 printk(KERN_EMERG
"JBD: failed to create handle cache\n");
2307 static void jbd2_journal_destroy_handle_cache(void)
2309 if (jbd2_handle_cache
)
2310 kmem_cache_destroy(jbd2_handle_cache
);
2314 * Module startup and shutdown
2317 static int __init
journal_init_caches(void)
2321 ret
= jbd2_journal_init_revoke_caches();
2323 ret
= journal_init_jbd2_journal_head_cache();
2325 ret
= journal_init_handle_cache();
2329 static void jbd2_journal_destroy_caches(void)
2331 jbd2_journal_destroy_revoke_caches();
2332 jbd2_journal_destroy_jbd2_journal_head_cache();
2333 jbd2_journal_destroy_handle_cache();
2334 jbd2_journal_destroy_slabs();
2337 static int __init
journal_init(void)
2341 BUILD_BUG_ON(sizeof(struct journal_superblock_s
) != 1024);
2343 ret
= journal_init_caches();
2345 jbd2_create_debugfs_entry();
2346 jbd2_create_jbd_stats_proc_entry();
2348 jbd2_journal_destroy_caches();
2353 static void __exit
journal_exit(void)
2355 #ifdef CONFIG_JBD2_DEBUG
2356 int n
= atomic_read(&nr_journal_heads
);
2358 printk(KERN_EMERG
"JBD: leaked %d journal_heads!\n", n
);
2360 jbd2_remove_debugfs_entry();
2361 jbd2_remove_jbd_stats_proc_entry();
2362 jbd2_journal_destroy_caches();
2366 * jbd2_dev_to_name is a utility function used by the jbd2 and ext4
2367 * tracing infrastructure to map a dev_t to a device name.
2369 * The caller should use rcu_read_lock() in order to make sure the
2370 * device name stays valid until its done with it. We use
2371 * rcu_read_lock() as well to make sure we're safe in case the caller
2372 * gets sloppy, and because rcu_read_lock() is cheap and can be safely
2375 struct devname_cache
{
2376 struct rcu_head rcu
;
2378 char devname
[BDEVNAME_SIZE
];
2380 #define CACHE_SIZE_BITS 6
2381 static struct devname_cache
*devcache
[1 << CACHE_SIZE_BITS
];
2382 static DEFINE_SPINLOCK(devname_cache_lock
);
2384 static void free_devcache(struct rcu_head
*rcu
)
2389 const char *jbd2_dev_to_name(dev_t device
)
2391 int i
= hash_32(device
, CACHE_SIZE_BITS
);
2393 struct block_device
*bd
;
2394 static struct devname_cache
*new_dev
;
2397 if (devcache
[i
] && devcache
[i
]->device
== device
) {
2398 ret
= devcache
[i
]->devname
;
2404 new_dev
= kmalloc(sizeof(struct devname_cache
), GFP_KERNEL
);
2406 return "NODEV-ALLOCFAILURE"; /* Something non-NULL */
2407 spin_lock(&devname_cache_lock
);
2409 if (devcache
[i
]->device
== device
) {
2411 ret
= devcache
[i
]->devname
;
2412 spin_unlock(&devname_cache_lock
);
2415 call_rcu(&devcache
[i
]->rcu
, free_devcache
);
2417 devcache
[i
] = new_dev
;
2418 devcache
[i
]->device
= device
;
2421 bdevname(bd
, devcache
[i
]->devname
);
2424 __bdevname(device
, devcache
[i
]->devname
);
2425 ret
= devcache
[i
]->devname
;
2426 spin_unlock(&devname_cache_lock
);
2429 EXPORT_SYMBOL(jbd2_dev_to_name
);
2431 MODULE_LICENSE("GPL");
2432 module_init(journal_init
);
2433 module_exit(journal_exit
);