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>
41 #include <asm/uaccess.h>
43 #include <asm/div64.h>
45 EXPORT_SYMBOL(jbd2_journal_start
);
46 EXPORT_SYMBOL(jbd2_journal_restart
);
47 EXPORT_SYMBOL(jbd2_journal_extend
);
48 EXPORT_SYMBOL(jbd2_journal_stop
);
49 EXPORT_SYMBOL(jbd2_journal_lock_updates
);
50 EXPORT_SYMBOL(jbd2_journal_unlock_updates
);
51 EXPORT_SYMBOL(jbd2_journal_get_write_access
);
52 EXPORT_SYMBOL(jbd2_journal_get_create_access
);
53 EXPORT_SYMBOL(jbd2_journal_get_undo_access
);
54 EXPORT_SYMBOL(jbd2_journal_dirty_metadata
);
55 EXPORT_SYMBOL(jbd2_journal_release_buffer
);
56 EXPORT_SYMBOL(jbd2_journal_forget
);
58 EXPORT_SYMBOL(journal_sync_buffer
);
60 EXPORT_SYMBOL(jbd2_journal_flush
);
61 EXPORT_SYMBOL(jbd2_journal_revoke
);
63 EXPORT_SYMBOL(jbd2_journal_init_dev
);
64 EXPORT_SYMBOL(jbd2_journal_init_inode
);
65 EXPORT_SYMBOL(jbd2_journal_update_format
);
66 EXPORT_SYMBOL(jbd2_journal_check_used_features
);
67 EXPORT_SYMBOL(jbd2_journal_check_available_features
);
68 EXPORT_SYMBOL(jbd2_journal_set_features
);
69 EXPORT_SYMBOL(jbd2_journal_load
);
70 EXPORT_SYMBOL(jbd2_journal_destroy
);
71 EXPORT_SYMBOL(jbd2_journal_abort
);
72 EXPORT_SYMBOL(jbd2_journal_errno
);
73 EXPORT_SYMBOL(jbd2_journal_ack_err
);
74 EXPORT_SYMBOL(jbd2_journal_clear_err
);
75 EXPORT_SYMBOL(jbd2_log_wait_commit
);
76 EXPORT_SYMBOL(jbd2_journal_start_commit
);
77 EXPORT_SYMBOL(jbd2_journal_force_commit_nested
);
78 EXPORT_SYMBOL(jbd2_journal_wipe
);
79 EXPORT_SYMBOL(jbd2_journal_blocks_per_page
);
80 EXPORT_SYMBOL(jbd2_journal_invalidatepage
);
81 EXPORT_SYMBOL(jbd2_journal_try_to_free_buffers
);
82 EXPORT_SYMBOL(jbd2_journal_force_commit
);
83 EXPORT_SYMBOL(jbd2_journal_file_inode
);
84 EXPORT_SYMBOL(jbd2_journal_init_jbd_inode
);
85 EXPORT_SYMBOL(jbd2_journal_release_jbd_inode
);
86 EXPORT_SYMBOL(jbd2_journal_begin_ordered_truncate
);
88 static int journal_convert_superblock_v1(journal_t
*, journal_superblock_t
*);
89 static void __journal_abort_soft (journal_t
*journal
, int errno
);
92 * Helper function used to manage commit timeouts
95 static void commit_timeout(unsigned long __data
)
97 struct task_struct
* p
= (struct task_struct
*) __data
;
103 * kjournald2: The main thread function used to manage a logging device
106 * This kernel thread is responsible for two things:
108 * 1) COMMIT: Every so often we need to commit the current state of the
109 * filesystem to disk. The journal thread is responsible for writing
110 * all of the metadata buffers to disk.
112 * 2) CHECKPOINT: We cannot reuse a used section of the log file until all
113 * of the data in that part of the log has been rewritten elsewhere on
114 * the disk. Flushing these old buffers to reclaim space in the log is
115 * known as checkpointing, and this thread is responsible for that job.
118 static int kjournald2(void *arg
)
120 journal_t
*journal
= arg
;
121 transaction_t
*transaction
;
124 * Set up an interval timer which can be used to trigger a commit wakeup
125 * after the commit interval expires
127 setup_timer(&journal
->j_commit_timer
, commit_timeout
,
128 (unsigned long)current
);
130 /* Record that the journal thread is running */
131 journal
->j_task
= current
;
132 wake_up(&journal
->j_wait_done_commit
);
134 printk(KERN_INFO
"kjournald2 starting: pid %d, dev %s, "
135 "commit interval %ld seconds\n", current
->pid
,
136 journal
->j_devname
, journal
->j_commit_interval
/ HZ
);
139 * And now, wait forever for commit wakeup events.
141 spin_lock(&journal
->j_state_lock
);
144 if (journal
->j_flags
& JBD2_UNMOUNT
)
147 jbd_debug(1, "commit_sequence=%d, commit_request=%d\n",
148 journal
->j_commit_sequence
, journal
->j_commit_request
);
150 if (journal
->j_commit_sequence
!= journal
->j_commit_request
) {
151 jbd_debug(1, "OK, requests differ\n");
152 spin_unlock(&journal
->j_state_lock
);
153 del_timer_sync(&journal
->j_commit_timer
);
154 jbd2_journal_commit_transaction(journal
);
155 spin_lock(&journal
->j_state_lock
);
159 wake_up(&journal
->j_wait_done_commit
);
160 if (freezing(current
)) {
162 * The simpler the better. Flushing journal isn't a
163 * good idea, because that depends on threads that may
164 * be already stopped.
166 jbd_debug(1, "Now suspending kjournald2\n");
167 spin_unlock(&journal
->j_state_lock
);
169 spin_lock(&journal
->j_state_lock
);
172 * We assume on resume that commits are already there,
176 int should_sleep
= 1;
178 prepare_to_wait(&journal
->j_wait_commit
, &wait
,
180 if (journal
->j_commit_sequence
!= journal
->j_commit_request
)
182 transaction
= journal
->j_running_transaction
;
183 if (transaction
&& time_after_eq(jiffies
,
184 transaction
->t_expires
))
186 if (journal
->j_flags
& JBD2_UNMOUNT
)
189 spin_unlock(&journal
->j_state_lock
);
191 spin_lock(&journal
->j_state_lock
);
193 finish_wait(&journal
->j_wait_commit
, &wait
);
196 jbd_debug(1, "kjournald2 wakes\n");
199 * Were we woken up by a commit wakeup event?
201 transaction
= journal
->j_running_transaction
;
202 if (transaction
&& time_after_eq(jiffies
, transaction
->t_expires
)) {
203 journal
->j_commit_request
= transaction
->t_tid
;
204 jbd_debug(1, "woke because of timeout\n");
209 spin_unlock(&journal
->j_state_lock
);
210 del_timer_sync(&journal
->j_commit_timer
);
211 journal
->j_task
= NULL
;
212 wake_up(&journal
->j_wait_done_commit
);
213 jbd_debug(1, "Journal thread exiting.\n");
217 static int jbd2_journal_start_thread(journal_t
*journal
)
219 struct task_struct
*t
;
221 t
= kthread_run(kjournald2
, journal
, "kjournald2");
225 wait_event(journal
->j_wait_done_commit
, journal
->j_task
!= NULL
);
229 static void journal_kill_thread(journal_t
*journal
)
231 spin_lock(&journal
->j_state_lock
);
232 journal
->j_flags
|= JBD2_UNMOUNT
;
234 while (journal
->j_task
) {
235 wake_up(&journal
->j_wait_commit
);
236 spin_unlock(&journal
->j_state_lock
);
237 wait_event(journal
->j_wait_done_commit
, journal
->j_task
== NULL
);
238 spin_lock(&journal
->j_state_lock
);
240 spin_unlock(&journal
->j_state_lock
);
244 * jbd2_journal_write_metadata_buffer: write a metadata buffer to the journal.
246 * Writes a metadata buffer to a given disk block. The actual IO is not
247 * performed but a new buffer_head is constructed which labels the data
248 * to be written with the correct destination disk block.
250 * Any magic-number escaping which needs to be done will cause a
251 * copy-out here. If the buffer happens to start with the
252 * JBD2_MAGIC_NUMBER, then we can't write it to the log directly: the
253 * magic number is only written to the log for descripter blocks. In
254 * this case, we copy the data and replace the first word with 0, and we
255 * return a result code which indicates that this buffer needs to be
256 * marked as an escaped buffer in the corresponding log descriptor
257 * block. The missing word can then be restored when the block is read
260 * If the source buffer has already been modified by a new transaction
261 * since we took the last commit snapshot, we use the frozen copy of
262 * that data for IO. If we end up using the existing buffer_head's data
263 * for the write, then we *have* to lock the buffer to prevent anyone
264 * else from using and possibly modifying it while the IO is in
267 * The function returns a pointer to the buffer_heads to be used for IO.
269 * We assume that the journal has already been locked in this function.
276 * Bit 0 set == escape performed on the data
277 * Bit 1 set == buffer copy-out performed (kfree the data after IO)
280 int jbd2_journal_write_metadata_buffer(transaction_t
*transaction
,
281 struct journal_head
*jh_in
,
282 struct journal_head
**jh_out
,
283 unsigned long long blocknr
)
285 int need_copy_out
= 0;
286 int done_copy_out
= 0;
289 struct buffer_head
*new_bh
;
290 struct journal_head
*new_jh
;
291 struct page
*new_page
;
292 unsigned int new_offset
;
293 struct buffer_head
*bh_in
= jh2bh(jh_in
);
296 * The buffer really shouldn't be locked: only the current committing
297 * transaction is allowed to write it, so nobody else is allowed
300 * akpm: except if we're journalling data, and write() output is
301 * also part of a shared mapping, and another thread has
302 * decided to launch a writepage() against this buffer.
304 J_ASSERT_BH(bh_in
, buffer_jbddirty(bh_in
));
306 new_bh
= alloc_buffer_head(GFP_NOFS
|__GFP_NOFAIL
);
309 * If a new transaction has already done a buffer copy-out, then
310 * we use that version of the data for the commit.
312 jbd_lock_bh_state(bh_in
);
314 if (jh_in
->b_frozen_data
) {
316 new_page
= virt_to_page(jh_in
->b_frozen_data
);
317 new_offset
= offset_in_page(jh_in
->b_frozen_data
);
319 new_page
= jh2bh(jh_in
)->b_page
;
320 new_offset
= offset_in_page(jh2bh(jh_in
)->b_data
);
323 mapped_data
= kmap_atomic(new_page
, KM_USER0
);
327 if (*((__be32
*)(mapped_data
+ new_offset
)) ==
328 cpu_to_be32(JBD2_MAGIC_NUMBER
)) {
332 kunmap_atomic(mapped_data
, KM_USER0
);
335 * Do we need to do a data copy?
337 if (need_copy_out
&& !done_copy_out
) {
340 jbd_unlock_bh_state(bh_in
);
341 tmp
= jbd2_alloc(bh_in
->b_size
, GFP_NOFS
);
342 jbd_lock_bh_state(bh_in
);
343 if (jh_in
->b_frozen_data
) {
344 jbd2_free(tmp
, bh_in
->b_size
);
348 jh_in
->b_frozen_data
= tmp
;
349 mapped_data
= kmap_atomic(new_page
, KM_USER0
);
350 memcpy(tmp
, mapped_data
+ new_offset
, jh2bh(jh_in
)->b_size
);
351 kunmap_atomic(mapped_data
, KM_USER0
);
353 new_page
= virt_to_page(tmp
);
354 new_offset
= offset_in_page(tmp
);
359 * Did we need to do an escaping? Now we've done all the
360 * copying, we can finally do so.
363 mapped_data
= kmap_atomic(new_page
, KM_USER0
);
364 *((unsigned int *)(mapped_data
+ new_offset
)) = 0;
365 kunmap_atomic(mapped_data
, KM_USER0
);
368 /* keep subsequent assertions sane */
370 init_buffer(new_bh
, NULL
, NULL
);
371 atomic_set(&new_bh
->b_count
, 1);
372 jbd_unlock_bh_state(bh_in
);
374 new_jh
= jbd2_journal_add_journal_head(new_bh
); /* This sleeps */
376 set_bh_page(new_bh
, new_page
, new_offset
);
377 new_jh
->b_transaction
= NULL
;
378 new_bh
->b_size
= jh2bh(jh_in
)->b_size
;
379 new_bh
->b_bdev
= transaction
->t_journal
->j_dev
;
380 new_bh
->b_blocknr
= blocknr
;
381 set_buffer_mapped(new_bh
);
382 set_buffer_dirty(new_bh
);
387 * The to-be-written buffer needs to get moved to the io queue,
388 * and the original buffer whose contents we are shadowing or
389 * copying is moved to the transaction's shadow queue.
391 JBUFFER_TRACE(jh_in
, "file as BJ_Shadow");
392 jbd2_journal_file_buffer(jh_in
, transaction
, BJ_Shadow
);
393 JBUFFER_TRACE(new_jh
, "file as BJ_IO");
394 jbd2_journal_file_buffer(new_jh
, transaction
, BJ_IO
);
396 return do_escape
| (done_copy_out
<< 1);
400 * Allocation code for the journal file. Manage the space left in the
401 * journal, so that we can begin checkpointing when appropriate.
405 * __jbd2_log_space_left: Return the number of free blocks left in the journal.
407 * Called with the journal already locked.
409 * Called under j_state_lock
412 int __jbd2_log_space_left(journal_t
*journal
)
414 int left
= journal
->j_free
;
416 assert_spin_locked(&journal
->j_state_lock
);
419 * Be pessimistic here about the number of those free blocks which
420 * might be required for log descriptor control blocks.
423 #define MIN_LOG_RESERVED_BLOCKS 32 /* Allow for rounding errors */
425 left
-= MIN_LOG_RESERVED_BLOCKS
;
434 * Called under j_state_lock. Returns true if a transaction was started.
436 int __jbd2_log_start_commit(journal_t
*journal
, tid_t target
)
439 * Are we already doing a recent enough commit?
441 if (!tid_geq(journal
->j_commit_request
, target
)) {
443 * We want a new commit: OK, mark the request and wakup the
444 * commit thread. We do _not_ do the commit ourselves.
447 journal
->j_commit_request
= target
;
448 jbd_debug(1, "JBD: requesting commit %d/%d\n",
449 journal
->j_commit_request
,
450 journal
->j_commit_sequence
);
451 wake_up(&journal
->j_wait_commit
);
457 int jbd2_log_start_commit(journal_t
*journal
, tid_t tid
)
461 spin_lock(&journal
->j_state_lock
);
462 ret
= __jbd2_log_start_commit(journal
, tid
);
463 spin_unlock(&journal
->j_state_lock
);
468 * Force and wait upon a commit if the calling process is not within
469 * transaction. This is used for forcing out undo-protected data which contains
470 * bitmaps, when the fs is running out of space.
472 * We can only force the running transaction if we don't have an active handle;
473 * otherwise, we will deadlock.
475 * Returns true if a transaction was started.
477 int jbd2_journal_force_commit_nested(journal_t
*journal
)
479 transaction_t
*transaction
= NULL
;
482 spin_lock(&journal
->j_state_lock
);
483 if (journal
->j_running_transaction
&& !current
->journal_info
) {
484 transaction
= journal
->j_running_transaction
;
485 __jbd2_log_start_commit(journal
, transaction
->t_tid
);
486 } else if (journal
->j_committing_transaction
)
487 transaction
= journal
->j_committing_transaction
;
490 spin_unlock(&journal
->j_state_lock
);
491 return 0; /* Nothing to retry */
494 tid
= transaction
->t_tid
;
495 spin_unlock(&journal
->j_state_lock
);
496 jbd2_log_wait_commit(journal
, tid
);
501 * Start a commit of the current running transaction (if any). Returns true
502 * if a transaction was started, and fills its tid in at *ptid
504 int jbd2_journal_start_commit(journal_t
*journal
, tid_t
*ptid
)
508 spin_lock(&journal
->j_state_lock
);
509 if (journal
->j_running_transaction
) {
510 tid_t tid
= journal
->j_running_transaction
->t_tid
;
512 ret
= __jbd2_log_start_commit(journal
, tid
);
515 } else if (journal
->j_committing_transaction
&& ptid
) {
517 * If ext3_write_super() recently started a commit, then we
518 * have to wait for completion of that transaction
520 *ptid
= journal
->j_committing_transaction
->t_tid
;
523 spin_unlock(&journal
->j_state_lock
);
528 * Wait for a specified commit to complete.
529 * The caller may not hold the journal lock.
531 int jbd2_log_wait_commit(journal_t
*journal
, tid_t tid
)
535 #ifdef CONFIG_JBD2_DEBUG
536 spin_lock(&journal
->j_state_lock
);
537 if (!tid_geq(journal
->j_commit_request
, tid
)) {
539 "%s: error: j_commit_request=%d, tid=%d\n",
540 __func__
, journal
->j_commit_request
, tid
);
542 spin_unlock(&journal
->j_state_lock
);
544 spin_lock(&journal
->j_state_lock
);
545 while (tid_gt(tid
, journal
->j_commit_sequence
)) {
546 jbd_debug(1, "JBD: want %d, j_commit_sequence=%d\n",
547 tid
, journal
->j_commit_sequence
);
548 wake_up(&journal
->j_wait_commit
);
549 spin_unlock(&journal
->j_state_lock
);
550 wait_event(journal
->j_wait_done_commit
,
551 !tid_gt(tid
, journal
->j_commit_sequence
));
552 spin_lock(&journal
->j_state_lock
);
554 spin_unlock(&journal
->j_state_lock
);
556 if (unlikely(is_journal_aborted(journal
))) {
557 printk(KERN_EMERG
"journal commit I/O error\n");
564 * Log buffer allocation routines:
567 int jbd2_journal_next_log_block(journal_t
*journal
, unsigned long long *retp
)
569 unsigned long blocknr
;
571 spin_lock(&journal
->j_state_lock
);
572 J_ASSERT(journal
->j_free
> 1);
574 blocknr
= journal
->j_head
;
577 if (journal
->j_head
== journal
->j_last
)
578 journal
->j_head
= journal
->j_first
;
579 spin_unlock(&journal
->j_state_lock
);
580 return jbd2_journal_bmap(journal
, blocknr
, retp
);
584 * Conversion of logical to physical block numbers for the journal
586 * On external journals the journal blocks are identity-mapped, so
587 * this is a no-op. If needed, we can use j_blk_offset - everything is
590 int jbd2_journal_bmap(journal_t
*journal
, unsigned long blocknr
,
591 unsigned long long *retp
)
594 unsigned long long ret
;
596 if (journal
->j_inode
) {
597 ret
= bmap(journal
->j_inode
, blocknr
);
601 printk(KERN_ALERT
"%s: journal block not found "
602 "at offset %lu on %s\n",
603 __func__
, blocknr
, journal
->j_devname
);
605 __journal_abort_soft(journal
, err
);
608 *retp
= blocknr
; /* +journal->j_blk_offset */
614 * We play buffer_head aliasing tricks to write data/metadata blocks to
615 * the journal without copying their contents, but for journal
616 * descriptor blocks we do need to generate bona fide buffers.
618 * After the caller of jbd2_journal_get_descriptor_buffer() has finished modifying
619 * the buffer's contents they really should run flush_dcache_page(bh->b_page).
620 * But we don't bother doing that, so there will be coherency problems with
621 * mmaps of blockdevs which hold live JBD-controlled filesystems.
623 struct journal_head
*jbd2_journal_get_descriptor_buffer(journal_t
*journal
)
625 struct buffer_head
*bh
;
626 unsigned long long blocknr
;
629 err
= jbd2_journal_next_log_block(journal
, &blocknr
);
634 bh
= __getblk(journal
->j_dev
, blocknr
, journal
->j_blocksize
);
638 memset(bh
->b_data
, 0, journal
->j_blocksize
);
639 set_buffer_uptodate(bh
);
641 BUFFER_TRACE(bh
, "return this buffer");
642 return jbd2_journal_add_journal_head(bh
);
645 struct jbd2_stats_proc_session
{
647 struct transaction_stats_s
*stats
;
652 static void *jbd2_history_skip_empty(struct jbd2_stats_proc_session
*s
,
653 struct transaction_stats_s
*ts
,
656 if (ts
== s
->stats
+ s
->max
)
658 if (!first
&& ts
== s
->stats
+ s
->start
)
660 while (ts
->ts_type
== 0) {
662 if (ts
== s
->stats
+ s
->max
)
664 if (ts
== s
->stats
+ s
->start
)
671 static void *jbd2_seq_history_start(struct seq_file
*seq
, loff_t
*pos
)
673 struct jbd2_stats_proc_session
*s
= seq
->private;
674 struct transaction_stats_s
*ts
;
678 return SEQ_START_TOKEN
;
679 ts
= jbd2_history_skip_empty(s
, s
->stats
+ s
->start
, 1);
684 ts
= jbd2_history_skip_empty(s
, ++ts
, 0);
692 static void *jbd2_seq_history_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
694 struct jbd2_stats_proc_session
*s
= seq
->private;
695 struct transaction_stats_s
*ts
= v
;
698 if (v
== SEQ_START_TOKEN
)
699 return jbd2_history_skip_empty(s
, s
->stats
+ s
->start
, 1);
701 return jbd2_history_skip_empty(s
, ++ts
, 0);
704 static int jbd2_seq_history_show(struct seq_file
*seq
, void *v
)
706 struct transaction_stats_s
*ts
= v
;
707 if (v
== SEQ_START_TOKEN
) {
708 seq_printf(seq
, "%-4s %-5s %-5s %-5s %-5s %-5s %-5s %-6s %-5s "
709 "%-5s %-5s %-5s %-5s %-5s\n", "R/C", "tid",
710 "wait", "run", "lock", "flush", "log", "hndls",
711 "block", "inlog", "ctime", "write", "drop",
715 if (ts
->ts_type
== JBD2_STATS_RUN
)
716 seq_printf(seq
, "%-4s %-5lu %-5u %-5u %-5u %-5u %-5u "
717 "%-6lu %-5lu %-5lu\n", "R", ts
->ts_tid
,
718 jiffies_to_msecs(ts
->u
.run
.rs_wait
),
719 jiffies_to_msecs(ts
->u
.run
.rs_running
),
720 jiffies_to_msecs(ts
->u
.run
.rs_locked
),
721 jiffies_to_msecs(ts
->u
.run
.rs_flushing
),
722 jiffies_to_msecs(ts
->u
.run
.rs_logging
),
723 ts
->u
.run
.rs_handle_count
,
725 ts
->u
.run
.rs_blocks_logged
);
726 else if (ts
->ts_type
== JBD2_STATS_CHECKPOINT
)
727 seq_printf(seq
, "%-4s %-5lu %48s %-5u %-5lu %-5lu %-5lu\n",
728 "C", ts
->ts_tid
, " ",
729 jiffies_to_msecs(ts
->u
.chp
.cs_chp_time
),
730 ts
->u
.chp
.cs_written
, ts
->u
.chp
.cs_dropped
,
731 ts
->u
.chp
.cs_forced_to_close
);
737 static void jbd2_seq_history_stop(struct seq_file
*seq
, void *v
)
741 static struct seq_operations jbd2_seq_history_ops
= {
742 .start
= jbd2_seq_history_start
,
743 .next
= jbd2_seq_history_next
,
744 .stop
= jbd2_seq_history_stop
,
745 .show
= jbd2_seq_history_show
,
748 static int jbd2_seq_history_open(struct inode
*inode
, struct file
*file
)
750 journal_t
*journal
= PDE(inode
)->data
;
751 struct jbd2_stats_proc_session
*s
;
754 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
757 size
= sizeof(struct transaction_stats_s
) * journal
->j_history_max
;
758 s
->stats
= kmalloc(size
, GFP_KERNEL
);
759 if (s
->stats
== NULL
) {
763 spin_lock(&journal
->j_history_lock
);
764 memcpy(s
->stats
, journal
->j_history
, size
);
765 s
->max
= journal
->j_history_max
;
766 s
->start
= journal
->j_history_cur
% s
->max
;
767 spin_unlock(&journal
->j_history_lock
);
769 rc
= seq_open(file
, &jbd2_seq_history_ops
);
771 struct seq_file
*m
= file
->private_data
;
781 static int jbd2_seq_history_release(struct inode
*inode
, struct file
*file
)
783 struct seq_file
*seq
= file
->private_data
;
784 struct jbd2_stats_proc_session
*s
= seq
->private;
788 return seq_release(inode
, file
);
791 static struct file_operations jbd2_seq_history_fops
= {
792 .owner
= THIS_MODULE
,
793 .open
= jbd2_seq_history_open
,
796 .release
= jbd2_seq_history_release
,
799 static void *jbd2_seq_info_start(struct seq_file
*seq
, loff_t
*pos
)
801 return *pos
? NULL
: SEQ_START_TOKEN
;
804 static void *jbd2_seq_info_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
809 static int jbd2_seq_info_show(struct seq_file
*seq
, void *v
)
811 struct jbd2_stats_proc_session
*s
= seq
->private;
813 if (v
!= SEQ_START_TOKEN
)
815 seq_printf(seq
, "%lu transaction, each upto %u blocks\n",
817 s
->journal
->j_max_transaction_buffers
);
818 if (s
->stats
->ts_tid
== 0)
820 seq_printf(seq
, "average: \n %ums waiting for transaction\n",
821 jiffies_to_msecs(s
->stats
->u
.run
.rs_wait
/ s
->stats
->ts_tid
));
822 seq_printf(seq
, " %ums running transaction\n",
823 jiffies_to_msecs(s
->stats
->u
.run
.rs_running
/ s
->stats
->ts_tid
));
824 seq_printf(seq
, " %ums transaction was being locked\n",
825 jiffies_to_msecs(s
->stats
->u
.run
.rs_locked
/ s
->stats
->ts_tid
));
826 seq_printf(seq
, " %ums flushing data (in ordered mode)\n",
827 jiffies_to_msecs(s
->stats
->u
.run
.rs_flushing
/ s
->stats
->ts_tid
));
828 seq_printf(seq
, " %ums logging transaction\n",
829 jiffies_to_msecs(s
->stats
->u
.run
.rs_logging
/ s
->stats
->ts_tid
));
830 seq_printf(seq
, " %luus average transaction commit time\n",
831 do_div(s
->journal
->j_average_commit_time
, 1000));
832 seq_printf(seq
, " %lu handles per transaction\n",
833 s
->stats
->u
.run
.rs_handle_count
/ s
->stats
->ts_tid
);
834 seq_printf(seq
, " %lu blocks per transaction\n",
835 s
->stats
->u
.run
.rs_blocks
/ s
->stats
->ts_tid
);
836 seq_printf(seq
, " %lu logged blocks per transaction\n",
837 s
->stats
->u
.run
.rs_blocks_logged
/ s
->stats
->ts_tid
);
841 static void jbd2_seq_info_stop(struct seq_file
*seq
, void *v
)
845 static struct seq_operations jbd2_seq_info_ops
= {
846 .start
= jbd2_seq_info_start
,
847 .next
= jbd2_seq_info_next
,
848 .stop
= jbd2_seq_info_stop
,
849 .show
= jbd2_seq_info_show
,
852 static int jbd2_seq_info_open(struct inode
*inode
, struct file
*file
)
854 journal_t
*journal
= PDE(inode
)->data
;
855 struct jbd2_stats_proc_session
*s
;
858 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
861 size
= sizeof(struct transaction_stats_s
);
862 s
->stats
= kmalloc(size
, GFP_KERNEL
);
863 if (s
->stats
== NULL
) {
867 spin_lock(&journal
->j_history_lock
);
868 memcpy(s
->stats
, &journal
->j_stats
, size
);
869 s
->journal
= journal
;
870 spin_unlock(&journal
->j_history_lock
);
872 rc
= seq_open(file
, &jbd2_seq_info_ops
);
874 struct seq_file
*m
= file
->private_data
;
884 static int jbd2_seq_info_release(struct inode
*inode
, struct file
*file
)
886 struct seq_file
*seq
= file
->private_data
;
887 struct jbd2_stats_proc_session
*s
= seq
->private;
890 return seq_release(inode
, file
);
893 static struct file_operations jbd2_seq_info_fops
= {
894 .owner
= THIS_MODULE
,
895 .open
= jbd2_seq_info_open
,
898 .release
= jbd2_seq_info_release
,
901 static struct proc_dir_entry
*proc_jbd2_stats
;
903 static void jbd2_stats_proc_init(journal_t
*journal
)
905 journal
->j_proc_entry
= proc_mkdir(journal
->j_devname
, proc_jbd2_stats
);
906 if (journal
->j_proc_entry
) {
907 proc_create_data("history", S_IRUGO
, journal
->j_proc_entry
,
908 &jbd2_seq_history_fops
, journal
);
909 proc_create_data("info", S_IRUGO
, journal
->j_proc_entry
,
910 &jbd2_seq_info_fops
, journal
);
914 static void jbd2_stats_proc_exit(journal_t
*journal
)
916 remove_proc_entry("info", journal
->j_proc_entry
);
917 remove_proc_entry("history", journal
->j_proc_entry
);
918 remove_proc_entry(journal
->j_devname
, proc_jbd2_stats
);
921 static void journal_init_stats(journal_t
*journal
)
925 if (!proc_jbd2_stats
)
928 journal
->j_history_max
= 100;
929 size
= sizeof(struct transaction_stats_s
) * journal
->j_history_max
;
930 journal
->j_history
= kzalloc(size
, GFP_KERNEL
);
931 if (!journal
->j_history
) {
932 journal
->j_history_max
= 0;
935 spin_lock_init(&journal
->j_history_lock
);
939 * Management for journal control blocks: functions to create and
940 * destroy journal_t structures, and to initialise and read existing
941 * journal blocks from disk. */
943 /* First: create and setup a journal_t object in memory. We initialise
944 * very few fields yet: that has to wait until we have created the
945 * journal structures from from scratch, or loaded them from disk. */
947 static journal_t
* journal_init_common (void)
952 journal
= kzalloc(sizeof(*journal
), GFP_KERNEL
|__GFP_NOFAIL
);
956 init_waitqueue_head(&journal
->j_wait_transaction_locked
);
957 init_waitqueue_head(&journal
->j_wait_logspace
);
958 init_waitqueue_head(&journal
->j_wait_done_commit
);
959 init_waitqueue_head(&journal
->j_wait_checkpoint
);
960 init_waitqueue_head(&journal
->j_wait_commit
);
961 init_waitqueue_head(&journal
->j_wait_updates
);
962 mutex_init(&journal
->j_barrier
);
963 mutex_init(&journal
->j_checkpoint_mutex
);
964 spin_lock_init(&journal
->j_revoke_lock
);
965 spin_lock_init(&journal
->j_list_lock
);
966 spin_lock_init(&journal
->j_state_lock
);
968 journal
->j_commit_interval
= (HZ
* JBD2_DEFAULT_MAX_COMMIT_AGE
);
969 journal
->j_min_batch_time
= 0;
970 journal
->j_max_batch_time
= 15000; /* 15ms */
972 /* The journal is marked for error until we succeed with recovery! */
973 journal
->j_flags
= JBD2_ABORT
;
975 /* Set up a default-sized revoke table for the new mount. */
976 err
= jbd2_journal_init_revoke(journal
, JOURNAL_REVOKE_DEFAULT_HASH
);
982 journal_init_stats(journal
);
989 /* jbd2_journal_init_dev and jbd2_journal_init_inode:
991 * Create a journal structure assigned some fixed set of disk blocks to
992 * the journal. We don't actually touch those disk blocks yet, but we
993 * need to set up all of the mapping information to tell the journaling
994 * system where the journal blocks are.
999 * journal_t * jbd2_journal_init_dev() - creates and initialises a journal structure
1000 * @bdev: Block device on which to create the journal
1001 * @fs_dev: Device which hold journalled filesystem for this journal.
1002 * @start: Block nr Start of journal.
1003 * @len: Length of the journal in blocks.
1004 * @blocksize: blocksize of journalling device
1006 * Returns: a newly created journal_t *
1008 * jbd2_journal_init_dev creates a journal which maps a fixed contiguous
1009 * range of blocks on an arbitrary block device.
1012 journal_t
* jbd2_journal_init_dev(struct block_device
*bdev
,
1013 struct block_device
*fs_dev
,
1014 unsigned long long start
, int len
, int blocksize
)
1016 journal_t
*journal
= journal_init_common();
1017 struct buffer_head
*bh
;
1024 /* journal descriptor can store up to n blocks -bzzz */
1025 journal
->j_blocksize
= blocksize
;
1026 jbd2_stats_proc_init(journal
);
1027 n
= journal
->j_blocksize
/ sizeof(journal_block_tag_t
);
1028 journal
->j_wbufsize
= n
;
1029 journal
->j_wbuf
= kmalloc(n
* sizeof(struct buffer_head
*), GFP_KERNEL
);
1030 if (!journal
->j_wbuf
) {
1031 printk(KERN_ERR
"%s: Cant allocate bhs for commit thread\n",
1035 journal
->j_dev
= bdev
;
1036 journal
->j_fs_dev
= fs_dev
;
1037 journal
->j_blk_offset
= start
;
1038 journal
->j_maxlen
= len
;
1039 bdevname(journal
->j_dev
, journal
->j_devname
);
1040 p
= journal
->j_devname
;
1041 while ((p
= strchr(p
, '/')))
1044 bh
= __getblk(journal
->j_dev
, start
, journal
->j_blocksize
);
1047 "%s: Cannot get buffer for journal superblock\n",
1051 journal
->j_sb_buffer
= bh
;
1052 journal
->j_superblock
= (journal_superblock_t
*)bh
->b_data
;
1056 jbd2_stats_proc_exit(journal
);
1062 * journal_t * jbd2_journal_init_inode () - creates a journal which maps to a inode.
1063 * @inode: An inode to create the journal in
1065 * jbd2_journal_init_inode creates a journal which maps an on-disk inode as
1066 * the journal. The inode must exist already, must support bmap() and
1067 * must have all data blocks preallocated.
1069 journal_t
* jbd2_journal_init_inode (struct inode
*inode
)
1071 struct buffer_head
*bh
;
1072 journal_t
*journal
= journal_init_common();
1076 unsigned long long blocknr
;
1081 journal
->j_dev
= journal
->j_fs_dev
= inode
->i_sb
->s_bdev
;
1082 journal
->j_inode
= inode
;
1083 bdevname(journal
->j_dev
, journal
->j_devname
);
1084 p
= journal
->j_devname
;
1085 while ((p
= strchr(p
, '/')))
1087 p
= journal
->j_devname
+ strlen(journal
->j_devname
);
1088 sprintf(p
, ":%lu", journal
->j_inode
->i_ino
);
1090 "journal %p: inode %s/%ld, size %Ld, bits %d, blksize %ld\n",
1091 journal
, inode
->i_sb
->s_id
, inode
->i_ino
,
1092 (long long) inode
->i_size
,
1093 inode
->i_sb
->s_blocksize_bits
, inode
->i_sb
->s_blocksize
);
1095 journal
->j_maxlen
= inode
->i_size
>> inode
->i_sb
->s_blocksize_bits
;
1096 journal
->j_blocksize
= inode
->i_sb
->s_blocksize
;
1097 jbd2_stats_proc_init(journal
);
1099 /* journal descriptor can store up to n blocks -bzzz */
1100 n
= journal
->j_blocksize
/ sizeof(journal_block_tag_t
);
1101 journal
->j_wbufsize
= n
;
1102 journal
->j_wbuf
= kmalloc(n
* sizeof(struct buffer_head
*), GFP_KERNEL
);
1103 if (!journal
->j_wbuf
) {
1104 printk(KERN_ERR
"%s: Cant allocate bhs for commit thread\n",
1109 err
= jbd2_journal_bmap(journal
, 0, &blocknr
);
1110 /* If that failed, give up */
1112 printk(KERN_ERR
"%s: Cannnot locate journal superblock\n",
1117 bh
= __getblk(journal
->j_dev
, blocknr
, journal
->j_blocksize
);
1120 "%s: Cannot get buffer for journal superblock\n",
1124 journal
->j_sb_buffer
= bh
;
1125 journal
->j_superblock
= (journal_superblock_t
*)bh
->b_data
;
1129 jbd2_stats_proc_exit(journal
);
1135 * If the journal init or create aborts, we need to mark the journal
1136 * superblock as being NULL to prevent the journal destroy from writing
1137 * back a bogus superblock.
1139 static void journal_fail_superblock (journal_t
*journal
)
1141 struct buffer_head
*bh
= journal
->j_sb_buffer
;
1143 journal
->j_sb_buffer
= NULL
;
1147 * Given a journal_t structure, initialise the various fields for
1148 * startup of a new journaling session. We use this both when creating
1149 * a journal, and after recovering an old journal to reset it for
1153 static int journal_reset(journal_t
*journal
)
1155 journal_superblock_t
*sb
= journal
->j_superblock
;
1156 unsigned long long first
, last
;
1158 first
= be32_to_cpu(sb
->s_first
);
1159 last
= be32_to_cpu(sb
->s_maxlen
);
1161 journal
->j_first
= first
;
1162 journal
->j_last
= last
;
1164 journal
->j_head
= first
;
1165 journal
->j_tail
= first
;
1166 journal
->j_free
= last
- first
;
1168 journal
->j_tail_sequence
= journal
->j_transaction_sequence
;
1169 journal
->j_commit_sequence
= journal
->j_transaction_sequence
- 1;
1170 journal
->j_commit_request
= journal
->j_commit_sequence
;
1172 journal
->j_max_transaction_buffers
= journal
->j_maxlen
/ 4;
1174 /* Add the dynamic fields and write it to disk. */
1175 jbd2_journal_update_superblock(journal
, 1);
1176 return jbd2_journal_start_thread(journal
);
1180 * void jbd2_journal_update_superblock() - Update journal sb on disk.
1181 * @journal: The journal to update.
1182 * @wait: Set to '0' if you don't want to wait for IO completion.
1184 * Update a journal's dynamic superblock fields and write it to disk,
1185 * optionally waiting for the IO to complete.
1187 void jbd2_journal_update_superblock(journal_t
*journal
, int wait
)
1189 journal_superblock_t
*sb
= journal
->j_superblock
;
1190 struct buffer_head
*bh
= journal
->j_sb_buffer
;
1193 * As a special case, if the on-disk copy is already marked as needing
1194 * no recovery (s_start == 0) and there are no outstanding transactions
1195 * in the filesystem, then we can safely defer the superblock update
1196 * until the next commit by setting JBD2_FLUSHED. This avoids
1197 * attempting a write to a potential-readonly device.
1199 if (sb
->s_start
== 0 && journal
->j_tail_sequence
==
1200 journal
->j_transaction_sequence
) {
1201 jbd_debug(1,"JBD: Skipping superblock update on recovered sb "
1202 "(start %ld, seq %d, errno %d)\n",
1203 journal
->j_tail
, journal
->j_tail_sequence
,
1208 if (buffer_write_io_error(bh
)) {
1210 * Oh, dear. A previous attempt to write the journal
1211 * superblock failed. This could happen because the
1212 * USB device was yanked out. Or it could happen to
1213 * be a transient write error and maybe the block will
1214 * be remapped. Nothing we can do but to retry the
1215 * write and hope for the best.
1217 printk(KERN_ERR
"JBD2: previous I/O error detected "
1218 "for journal superblock update for %s.\n",
1219 journal
->j_devname
);
1220 clear_buffer_write_io_error(bh
);
1221 set_buffer_uptodate(bh
);
1224 spin_lock(&journal
->j_state_lock
);
1225 jbd_debug(1,"JBD: updating superblock (start %ld, seq %d, errno %d)\n",
1226 journal
->j_tail
, journal
->j_tail_sequence
, journal
->j_errno
);
1228 sb
->s_sequence
= cpu_to_be32(journal
->j_tail_sequence
);
1229 sb
->s_start
= cpu_to_be32(journal
->j_tail
);
1230 sb
->s_errno
= cpu_to_be32(journal
->j_errno
);
1231 spin_unlock(&journal
->j_state_lock
);
1233 BUFFER_TRACE(bh
, "marking dirty");
1234 mark_buffer_dirty(bh
);
1236 sync_dirty_buffer(bh
);
1237 if (buffer_write_io_error(bh
)) {
1238 printk(KERN_ERR
"JBD2: I/O error detected "
1239 "when updating journal superblock for %s.\n",
1240 journal
->j_devname
);
1241 clear_buffer_write_io_error(bh
);
1242 set_buffer_uptodate(bh
);
1245 ll_rw_block(SWRITE
, 1, &bh
);
1248 /* If we have just flushed the log (by marking s_start==0), then
1249 * any future commit will have to be careful to update the
1250 * superblock again to re-record the true start of the log. */
1252 spin_lock(&journal
->j_state_lock
);
1254 journal
->j_flags
&= ~JBD2_FLUSHED
;
1256 journal
->j_flags
|= JBD2_FLUSHED
;
1257 spin_unlock(&journal
->j_state_lock
);
1261 * Read the superblock for a given journal, performing initial
1262 * validation of the format.
1265 static int journal_get_superblock(journal_t
*journal
)
1267 struct buffer_head
*bh
;
1268 journal_superblock_t
*sb
;
1271 bh
= journal
->j_sb_buffer
;
1273 J_ASSERT(bh
!= NULL
);
1274 if (!buffer_uptodate(bh
)) {
1275 ll_rw_block(READ
, 1, &bh
);
1277 if (!buffer_uptodate(bh
)) {
1279 "JBD: IO error reading journal superblock\n");
1284 sb
= journal
->j_superblock
;
1288 if (sb
->s_header
.h_magic
!= cpu_to_be32(JBD2_MAGIC_NUMBER
) ||
1289 sb
->s_blocksize
!= cpu_to_be32(journal
->j_blocksize
)) {
1290 printk(KERN_WARNING
"JBD: no valid journal superblock found\n");
1294 switch(be32_to_cpu(sb
->s_header
.h_blocktype
)) {
1295 case JBD2_SUPERBLOCK_V1
:
1296 journal
->j_format_version
= 1;
1298 case JBD2_SUPERBLOCK_V2
:
1299 journal
->j_format_version
= 2;
1302 printk(KERN_WARNING
"JBD: unrecognised superblock format ID\n");
1306 if (be32_to_cpu(sb
->s_maxlen
) < journal
->j_maxlen
)
1307 journal
->j_maxlen
= be32_to_cpu(sb
->s_maxlen
);
1308 else if (be32_to_cpu(sb
->s_maxlen
) > journal
->j_maxlen
) {
1309 printk (KERN_WARNING
"JBD: journal file too short\n");
1316 journal_fail_superblock(journal
);
1321 * Load the on-disk journal superblock and read the key fields into the
1325 static int load_superblock(journal_t
*journal
)
1328 journal_superblock_t
*sb
;
1330 err
= journal_get_superblock(journal
);
1334 sb
= journal
->j_superblock
;
1336 journal
->j_tail_sequence
= be32_to_cpu(sb
->s_sequence
);
1337 journal
->j_tail
= be32_to_cpu(sb
->s_start
);
1338 journal
->j_first
= be32_to_cpu(sb
->s_first
);
1339 journal
->j_last
= be32_to_cpu(sb
->s_maxlen
);
1340 journal
->j_errno
= be32_to_cpu(sb
->s_errno
);
1347 * int jbd2_journal_load() - Read journal from disk.
1348 * @journal: Journal to act on.
1350 * Given a journal_t structure which tells us which disk blocks contain
1351 * a journal, read the journal from disk to initialise the in-memory
1354 int jbd2_journal_load(journal_t
*journal
)
1357 journal_superblock_t
*sb
;
1359 err
= load_superblock(journal
);
1363 sb
= journal
->j_superblock
;
1364 /* If this is a V2 superblock, then we have to check the
1365 * features flags on it. */
1367 if (journal
->j_format_version
>= 2) {
1368 if ((sb
->s_feature_ro_compat
&
1369 ~cpu_to_be32(JBD2_KNOWN_ROCOMPAT_FEATURES
)) ||
1370 (sb
->s_feature_incompat
&
1371 ~cpu_to_be32(JBD2_KNOWN_INCOMPAT_FEATURES
))) {
1372 printk (KERN_WARNING
1373 "JBD: Unrecognised features on journal\n");
1378 /* Let the recovery code check whether it needs to recover any
1379 * data from the journal. */
1380 if (jbd2_journal_recover(journal
))
1381 goto recovery_error
;
1383 /* OK, we've finished with the dynamic journal bits:
1384 * reinitialise the dynamic contents of the superblock in memory
1385 * and reset them on disk. */
1386 if (journal_reset(journal
))
1387 goto recovery_error
;
1389 journal
->j_flags
&= ~JBD2_ABORT
;
1390 journal
->j_flags
|= JBD2_LOADED
;
1394 printk (KERN_WARNING
"JBD: recovery failed\n");
1399 * void jbd2_journal_destroy() - Release a journal_t structure.
1400 * @journal: Journal to act on.
1402 * Release a journal_t structure once it is no longer in use by the
1404 * Return <0 if we couldn't clean up the journal.
1406 int jbd2_journal_destroy(journal_t
*journal
)
1410 /* Wait for the commit thread to wake up and die. */
1411 journal_kill_thread(journal
);
1413 /* Force a final log commit */
1414 if (journal
->j_running_transaction
)
1415 jbd2_journal_commit_transaction(journal
);
1417 /* Force any old transactions to disk */
1419 /* Totally anal locking here... */
1420 spin_lock(&journal
->j_list_lock
);
1421 while (journal
->j_checkpoint_transactions
!= NULL
) {
1422 spin_unlock(&journal
->j_list_lock
);
1423 mutex_lock(&journal
->j_checkpoint_mutex
);
1424 jbd2_log_do_checkpoint(journal
);
1425 mutex_unlock(&journal
->j_checkpoint_mutex
);
1426 spin_lock(&journal
->j_list_lock
);
1429 J_ASSERT(journal
->j_running_transaction
== NULL
);
1430 J_ASSERT(journal
->j_committing_transaction
== NULL
);
1431 J_ASSERT(journal
->j_checkpoint_transactions
== NULL
);
1432 spin_unlock(&journal
->j_list_lock
);
1434 if (journal
->j_sb_buffer
) {
1435 if (!is_journal_aborted(journal
)) {
1436 /* We can now mark the journal as empty. */
1437 journal
->j_tail
= 0;
1438 journal
->j_tail_sequence
=
1439 ++journal
->j_transaction_sequence
;
1440 jbd2_journal_update_superblock(journal
, 1);
1444 brelse(journal
->j_sb_buffer
);
1447 if (journal
->j_proc_entry
)
1448 jbd2_stats_proc_exit(journal
);
1449 if (journal
->j_inode
)
1450 iput(journal
->j_inode
);
1451 if (journal
->j_revoke
)
1452 jbd2_journal_destroy_revoke(journal
);
1453 kfree(journal
->j_wbuf
);
1461 *int jbd2_journal_check_used_features () - Check if features specified are used.
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 journal uses all of a given set of
1468 * features. Return true (non-zero) if it does.
1471 int jbd2_journal_check_used_features (journal_t
*journal
, unsigned long compat
,
1472 unsigned long ro
, unsigned long incompat
)
1474 journal_superblock_t
*sb
;
1476 if (!compat
&& !ro
&& !incompat
)
1478 if (journal
->j_format_version
== 1)
1481 sb
= journal
->j_superblock
;
1483 if (((be32_to_cpu(sb
->s_feature_compat
) & compat
) == compat
) &&
1484 ((be32_to_cpu(sb
->s_feature_ro_compat
) & ro
) == ro
) &&
1485 ((be32_to_cpu(sb
->s_feature_incompat
) & incompat
) == incompat
))
1492 * int jbd2_journal_check_available_features() - Check feature set in journalling layer
1493 * @journal: Journal to check.
1494 * @compat: bitmask of compatible features
1495 * @ro: bitmask of features that force read-only mount
1496 * @incompat: bitmask of incompatible features
1498 * Check whether the journaling code supports the use of
1499 * all of a given set of features on this journal. Return true
1500 * (non-zero) if it can. */
1502 int jbd2_journal_check_available_features (journal_t
*journal
, unsigned long compat
,
1503 unsigned long ro
, unsigned long incompat
)
1505 journal_superblock_t
*sb
;
1507 if (!compat
&& !ro
&& !incompat
)
1510 sb
= journal
->j_superblock
;
1512 /* We can support any known requested features iff the
1513 * superblock is in version 2. Otherwise we fail to support any
1514 * extended sb features. */
1516 if (journal
->j_format_version
!= 2)
1519 if ((compat
& JBD2_KNOWN_COMPAT_FEATURES
) == compat
&&
1520 (ro
& JBD2_KNOWN_ROCOMPAT_FEATURES
) == ro
&&
1521 (incompat
& JBD2_KNOWN_INCOMPAT_FEATURES
) == incompat
)
1528 * int jbd2_journal_set_features () - Mark a given journal feature in the superblock
1529 * @journal: Journal to act on.
1530 * @compat: bitmask of compatible features
1531 * @ro: bitmask of features that force read-only mount
1532 * @incompat: bitmask of incompatible features
1534 * Mark a given journal feature as present on the
1535 * superblock. Returns true if the requested features could be set.
1539 int jbd2_journal_set_features (journal_t
*journal
, unsigned long compat
,
1540 unsigned long ro
, unsigned long incompat
)
1542 journal_superblock_t
*sb
;
1544 if (jbd2_journal_check_used_features(journal
, compat
, ro
, incompat
))
1547 if (!jbd2_journal_check_available_features(journal
, compat
, ro
, incompat
))
1550 jbd_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n",
1551 compat
, ro
, incompat
);
1553 sb
= journal
->j_superblock
;
1555 sb
->s_feature_compat
|= cpu_to_be32(compat
);
1556 sb
->s_feature_ro_compat
|= cpu_to_be32(ro
);
1557 sb
->s_feature_incompat
|= cpu_to_be32(incompat
);
1563 * jbd2_journal_clear_features () - Clear a given journal feature in the
1565 * @journal: Journal to act on.
1566 * @compat: bitmask of compatible features
1567 * @ro: bitmask of features that force read-only mount
1568 * @incompat: bitmask of incompatible features
1570 * Clear a given journal feature as present on the
1573 void jbd2_journal_clear_features(journal_t
*journal
, unsigned long compat
,
1574 unsigned long ro
, unsigned long incompat
)
1576 journal_superblock_t
*sb
;
1578 jbd_debug(1, "Clear features 0x%lx/0x%lx/0x%lx\n",
1579 compat
, ro
, incompat
);
1581 sb
= journal
->j_superblock
;
1583 sb
->s_feature_compat
&= ~cpu_to_be32(compat
);
1584 sb
->s_feature_ro_compat
&= ~cpu_to_be32(ro
);
1585 sb
->s_feature_incompat
&= ~cpu_to_be32(incompat
);
1587 EXPORT_SYMBOL(jbd2_journal_clear_features
);
1590 * int jbd2_journal_update_format () - Update on-disk journal structure.
1591 * @journal: Journal to act on.
1593 * Given an initialised but unloaded journal struct, poke about in the
1594 * on-disk structure to update it to the most recent supported version.
1596 int jbd2_journal_update_format (journal_t
*journal
)
1598 journal_superblock_t
*sb
;
1601 err
= journal_get_superblock(journal
);
1605 sb
= journal
->j_superblock
;
1607 switch (be32_to_cpu(sb
->s_header
.h_blocktype
)) {
1608 case JBD2_SUPERBLOCK_V2
:
1610 case JBD2_SUPERBLOCK_V1
:
1611 return journal_convert_superblock_v1(journal
, sb
);
1618 static int journal_convert_superblock_v1(journal_t
*journal
,
1619 journal_superblock_t
*sb
)
1621 int offset
, blocksize
;
1622 struct buffer_head
*bh
;
1625 "JBD: Converting superblock from version 1 to 2.\n");
1627 /* Pre-initialise new fields to zero */
1628 offset
= ((char *) &(sb
->s_feature_compat
)) - ((char *) sb
);
1629 blocksize
= be32_to_cpu(sb
->s_blocksize
);
1630 memset(&sb
->s_feature_compat
, 0, blocksize
-offset
);
1632 sb
->s_nr_users
= cpu_to_be32(1);
1633 sb
->s_header
.h_blocktype
= cpu_to_be32(JBD2_SUPERBLOCK_V2
);
1634 journal
->j_format_version
= 2;
1636 bh
= journal
->j_sb_buffer
;
1637 BUFFER_TRACE(bh
, "marking dirty");
1638 mark_buffer_dirty(bh
);
1639 sync_dirty_buffer(bh
);
1645 * int jbd2_journal_flush () - Flush journal
1646 * @journal: Journal to act on.
1648 * Flush all data for a given journal to disk and empty the journal.
1649 * Filesystems can use this when remounting readonly to ensure that
1650 * recovery does not need to happen on remount.
1653 int jbd2_journal_flush(journal_t
*journal
)
1656 transaction_t
*transaction
= NULL
;
1657 unsigned long old_tail
;
1659 spin_lock(&journal
->j_state_lock
);
1661 /* Force everything buffered to the log... */
1662 if (journal
->j_running_transaction
) {
1663 transaction
= journal
->j_running_transaction
;
1664 __jbd2_log_start_commit(journal
, transaction
->t_tid
);
1665 } else if (journal
->j_committing_transaction
)
1666 transaction
= journal
->j_committing_transaction
;
1668 /* Wait for the log commit to complete... */
1670 tid_t tid
= transaction
->t_tid
;
1672 spin_unlock(&journal
->j_state_lock
);
1673 jbd2_log_wait_commit(journal
, tid
);
1675 spin_unlock(&journal
->j_state_lock
);
1678 /* ...and flush everything in the log out to disk. */
1679 spin_lock(&journal
->j_list_lock
);
1680 while (!err
&& journal
->j_checkpoint_transactions
!= NULL
) {
1681 spin_unlock(&journal
->j_list_lock
);
1682 mutex_lock(&journal
->j_checkpoint_mutex
);
1683 err
= jbd2_log_do_checkpoint(journal
);
1684 mutex_unlock(&journal
->j_checkpoint_mutex
);
1685 spin_lock(&journal
->j_list_lock
);
1687 spin_unlock(&journal
->j_list_lock
);
1689 if (is_journal_aborted(journal
))
1692 jbd2_cleanup_journal_tail(journal
);
1694 /* Finally, mark the journal as really needing no recovery.
1695 * This sets s_start==0 in the underlying superblock, which is
1696 * the magic code for a fully-recovered superblock. Any future
1697 * commits of data to the journal will restore the current
1699 spin_lock(&journal
->j_state_lock
);
1700 old_tail
= journal
->j_tail
;
1701 journal
->j_tail
= 0;
1702 spin_unlock(&journal
->j_state_lock
);
1703 jbd2_journal_update_superblock(journal
, 1);
1704 spin_lock(&journal
->j_state_lock
);
1705 journal
->j_tail
= old_tail
;
1707 J_ASSERT(!journal
->j_running_transaction
);
1708 J_ASSERT(!journal
->j_committing_transaction
);
1709 J_ASSERT(!journal
->j_checkpoint_transactions
);
1710 J_ASSERT(journal
->j_head
== journal
->j_tail
);
1711 J_ASSERT(journal
->j_tail_sequence
== journal
->j_transaction_sequence
);
1712 spin_unlock(&journal
->j_state_lock
);
1717 * int jbd2_journal_wipe() - Wipe journal contents
1718 * @journal: Journal to act on.
1719 * @write: flag (see below)
1721 * Wipe out all of the contents of a journal, safely. This will produce
1722 * a warning if the journal contains any valid recovery information.
1723 * Must be called between journal_init_*() and jbd2_journal_load().
1725 * If 'write' is non-zero, then we wipe out the journal on disk; otherwise
1726 * we merely suppress recovery.
1729 int jbd2_journal_wipe(journal_t
*journal
, int write
)
1731 journal_superblock_t
*sb
;
1734 J_ASSERT (!(journal
->j_flags
& JBD2_LOADED
));
1736 err
= load_superblock(journal
);
1740 sb
= journal
->j_superblock
;
1742 if (!journal
->j_tail
)
1745 printk (KERN_WARNING
"JBD: %s recovery information on journal\n",
1746 write
? "Clearing" : "Ignoring");
1748 err
= jbd2_journal_skip_recovery(journal
);
1750 jbd2_journal_update_superblock(journal
, 1);
1757 * Journal abort has very specific semantics, which we describe
1758 * for journal abort.
1760 * Two internal function, which provide abort to te jbd layer
1765 * Quick version for internal journal use (doesn't lock the journal).
1766 * Aborts hard --- we mark the abort as occurred, but do _nothing_ else,
1767 * and don't attempt to make any other journal updates.
1769 void __jbd2_journal_abort_hard(journal_t
*journal
)
1771 transaction_t
*transaction
;
1773 if (journal
->j_flags
& JBD2_ABORT
)
1776 printk(KERN_ERR
"Aborting journal on device %s.\n",
1777 journal
->j_devname
);
1779 spin_lock(&journal
->j_state_lock
);
1780 journal
->j_flags
|= JBD2_ABORT
;
1781 transaction
= journal
->j_running_transaction
;
1783 __jbd2_log_start_commit(journal
, transaction
->t_tid
);
1784 spin_unlock(&journal
->j_state_lock
);
1787 /* Soft abort: record the abort error status in the journal superblock,
1788 * but don't do any other IO. */
1789 static void __journal_abort_soft (journal_t
*journal
, int errno
)
1791 if (journal
->j_flags
& JBD2_ABORT
)
1794 if (!journal
->j_errno
)
1795 journal
->j_errno
= errno
;
1797 __jbd2_journal_abort_hard(journal
);
1800 jbd2_journal_update_superblock(journal
, 1);
1804 * void jbd2_journal_abort () - Shutdown the journal immediately.
1805 * @journal: the journal to shutdown.
1806 * @errno: an error number to record in the journal indicating
1807 * the reason for the shutdown.
1809 * Perform a complete, immediate shutdown of the ENTIRE
1810 * journal (not of a single transaction). This operation cannot be
1811 * undone without closing and reopening the journal.
1813 * The jbd2_journal_abort function is intended to support higher level error
1814 * recovery mechanisms such as the ext2/ext3 remount-readonly error
1817 * Journal abort has very specific semantics. Any existing dirty,
1818 * unjournaled buffers in the main filesystem will still be written to
1819 * disk by bdflush, but the journaling mechanism will be suspended
1820 * immediately and no further transaction commits will be honoured.
1822 * Any dirty, journaled buffers will be written back to disk without
1823 * hitting the journal. Atomicity cannot be guaranteed on an aborted
1824 * filesystem, but we _do_ attempt to leave as much data as possible
1825 * behind for fsck to use for cleanup.
1827 * Any attempt to get a new transaction handle on a journal which is in
1828 * ABORT state will just result in an -EROFS error return. A
1829 * jbd2_journal_stop on an existing handle will return -EIO if we have
1830 * entered abort state during the update.
1832 * Recursive transactions are not disturbed by journal abort until the
1833 * final jbd2_journal_stop, which will receive the -EIO error.
1835 * Finally, the jbd2_journal_abort call allows the caller to supply an errno
1836 * which will be recorded (if possible) in the journal superblock. This
1837 * allows a client to record failure conditions in the middle of a
1838 * transaction without having to complete the transaction to record the
1839 * failure to disk. ext3_error, for example, now uses this
1842 * Errors which originate from within the journaling layer will NOT
1843 * supply an errno; a null errno implies that absolutely no further
1844 * writes are done to the journal (unless there are any already in
1849 void jbd2_journal_abort(journal_t
*journal
, int errno
)
1851 __journal_abort_soft(journal
, errno
);
1855 * int jbd2_journal_errno () - returns the journal's error state.
1856 * @journal: journal to examine.
1858 * This is the errno numbet set with jbd2_journal_abort(), the last
1859 * time the journal was mounted - if the journal was stopped
1860 * without calling abort this will be 0.
1862 * If the journal has been aborted on this mount time -EROFS will
1865 int jbd2_journal_errno(journal_t
*journal
)
1869 spin_lock(&journal
->j_state_lock
);
1870 if (journal
->j_flags
& JBD2_ABORT
)
1873 err
= journal
->j_errno
;
1874 spin_unlock(&journal
->j_state_lock
);
1879 * int jbd2_journal_clear_err () - clears the journal's error state
1880 * @journal: journal to act on.
1882 * An error must be cleared or Acked to take a FS out of readonly
1885 int jbd2_journal_clear_err(journal_t
*journal
)
1889 spin_lock(&journal
->j_state_lock
);
1890 if (journal
->j_flags
& JBD2_ABORT
)
1893 journal
->j_errno
= 0;
1894 spin_unlock(&journal
->j_state_lock
);
1899 * void jbd2_journal_ack_err() - Ack journal err.
1900 * @journal: journal to act on.
1902 * An error must be cleared or Acked to take a FS out of readonly
1905 void jbd2_journal_ack_err(journal_t
*journal
)
1907 spin_lock(&journal
->j_state_lock
);
1908 if (journal
->j_errno
)
1909 journal
->j_flags
|= JBD2_ACK_ERR
;
1910 spin_unlock(&journal
->j_state_lock
);
1913 int jbd2_journal_blocks_per_page(struct inode
*inode
)
1915 return 1 << (PAGE_CACHE_SHIFT
- inode
->i_sb
->s_blocksize_bits
);
1919 * helper functions to deal with 32 or 64bit block numbers.
1921 size_t journal_tag_bytes(journal_t
*journal
)
1923 if (JBD2_HAS_INCOMPAT_FEATURE(journal
, JBD2_FEATURE_INCOMPAT_64BIT
))
1924 return JBD2_TAG_SIZE64
;
1926 return JBD2_TAG_SIZE32
;
1930 * Journal_head storage management
1932 static struct kmem_cache
*jbd2_journal_head_cache
;
1933 #ifdef CONFIG_JBD2_DEBUG
1934 static atomic_t nr_journal_heads
= ATOMIC_INIT(0);
1937 static int journal_init_jbd2_journal_head_cache(void)
1941 J_ASSERT(jbd2_journal_head_cache
== NULL
);
1942 jbd2_journal_head_cache
= kmem_cache_create("jbd2_journal_head",
1943 sizeof(struct journal_head
),
1945 SLAB_TEMPORARY
, /* flags */
1948 if (!jbd2_journal_head_cache
) {
1950 printk(KERN_EMERG
"JBD: no memory for journal_head cache\n");
1955 static void jbd2_journal_destroy_jbd2_journal_head_cache(void)
1957 if (jbd2_journal_head_cache
) {
1958 kmem_cache_destroy(jbd2_journal_head_cache
);
1959 jbd2_journal_head_cache
= NULL
;
1964 * journal_head splicing and dicing
1966 static struct journal_head
*journal_alloc_journal_head(void)
1968 struct journal_head
*ret
;
1969 static unsigned long last_warning
;
1971 #ifdef CONFIG_JBD2_DEBUG
1972 atomic_inc(&nr_journal_heads
);
1974 ret
= kmem_cache_alloc(jbd2_journal_head_cache
, GFP_NOFS
);
1976 jbd_debug(1, "out of memory for journal_head\n");
1977 if (time_after(jiffies
, last_warning
+ 5*HZ
)) {
1978 printk(KERN_NOTICE
"ENOMEM in %s, retrying.\n",
1980 last_warning
= jiffies
;
1984 ret
= kmem_cache_alloc(jbd2_journal_head_cache
, GFP_NOFS
);
1990 static void journal_free_journal_head(struct journal_head
*jh
)
1992 #ifdef CONFIG_JBD2_DEBUG
1993 atomic_dec(&nr_journal_heads
);
1994 memset(jh
, JBD2_POISON_FREE
, sizeof(*jh
));
1996 kmem_cache_free(jbd2_journal_head_cache
, jh
);
2000 * A journal_head is attached to a buffer_head whenever JBD has an
2001 * interest in the buffer.
2003 * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit
2004 * is set. This bit is tested in core kernel code where we need to take
2005 * JBD-specific actions. Testing the zeroness of ->b_private is not reliable
2008 * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one.
2010 * When a buffer has its BH_JBD bit set it is immune from being released by
2011 * core kernel code, mainly via ->b_count.
2013 * A journal_head may be detached from its buffer_head when the journal_head's
2014 * b_transaction, b_cp_transaction and b_next_transaction pointers are NULL.
2015 * Various places in JBD call jbd2_journal_remove_journal_head() to indicate that the
2016 * journal_head can be dropped if needed.
2018 * Various places in the kernel want to attach a journal_head to a buffer_head
2019 * _before_ attaching the journal_head to a transaction. To protect the
2020 * journal_head in this situation, jbd2_journal_add_journal_head elevates the
2021 * journal_head's b_jcount refcount by one. The caller must call
2022 * jbd2_journal_put_journal_head() to undo this.
2024 * So the typical usage would be:
2026 * (Attach a journal_head if needed. Increments b_jcount)
2027 * struct journal_head *jh = jbd2_journal_add_journal_head(bh);
2029 * jh->b_transaction = xxx;
2030 * jbd2_journal_put_journal_head(jh);
2032 * Now, the journal_head's b_jcount is zero, but it is safe from being released
2033 * because it has a non-zero b_transaction.
2037 * Give a buffer_head a journal_head.
2039 * Doesn't need the journal lock.
2042 struct journal_head
*jbd2_journal_add_journal_head(struct buffer_head
*bh
)
2044 struct journal_head
*jh
;
2045 struct journal_head
*new_jh
= NULL
;
2048 if (!buffer_jbd(bh
)) {
2049 new_jh
= journal_alloc_journal_head();
2050 memset(new_jh
, 0, sizeof(*new_jh
));
2053 jbd_lock_bh_journal_head(bh
);
2054 if (buffer_jbd(bh
)) {
2058 (atomic_read(&bh
->b_count
) > 0) ||
2059 (bh
->b_page
&& bh
->b_page
->mapping
));
2062 jbd_unlock_bh_journal_head(bh
);
2067 new_jh
= NULL
; /* We consumed it */
2072 BUFFER_TRACE(bh
, "added journal_head");
2075 jbd_unlock_bh_journal_head(bh
);
2077 journal_free_journal_head(new_jh
);
2078 return bh
->b_private
;
2082 * Grab a ref against this buffer_head's journal_head. If it ended up not
2083 * having a journal_head, return NULL
2085 struct journal_head
*jbd2_journal_grab_journal_head(struct buffer_head
*bh
)
2087 struct journal_head
*jh
= NULL
;
2089 jbd_lock_bh_journal_head(bh
);
2090 if (buffer_jbd(bh
)) {
2094 jbd_unlock_bh_journal_head(bh
);
2098 static void __journal_remove_journal_head(struct buffer_head
*bh
)
2100 struct journal_head
*jh
= bh2jh(bh
);
2102 J_ASSERT_JH(jh
, jh
->b_jcount
>= 0);
2105 if (jh
->b_jcount
== 0) {
2106 if (jh
->b_transaction
== NULL
&&
2107 jh
->b_next_transaction
== NULL
&&
2108 jh
->b_cp_transaction
== NULL
) {
2109 J_ASSERT_JH(jh
, jh
->b_jlist
== BJ_None
);
2110 J_ASSERT_BH(bh
, buffer_jbd(bh
));
2111 J_ASSERT_BH(bh
, jh2bh(jh
) == bh
);
2112 BUFFER_TRACE(bh
, "remove journal_head");
2113 if (jh
->b_frozen_data
) {
2114 printk(KERN_WARNING
"%s: freeing "
2117 jbd2_free(jh
->b_frozen_data
, bh
->b_size
);
2119 if (jh
->b_committed_data
) {
2120 printk(KERN_WARNING
"%s: freeing "
2121 "b_committed_data\n",
2123 jbd2_free(jh
->b_committed_data
, bh
->b_size
);
2125 bh
->b_private
= NULL
;
2126 jh
->b_bh
= NULL
; /* debug, really */
2127 clear_buffer_jbd(bh
);
2129 journal_free_journal_head(jh
);
2131 BUFFER_TRACE(bh
, "journal_head was locked");
2137 * jbd2_journal_remove_journal_head(): if the buffer isn't attached to a transaction
2138 * and has a zero b_jcount then remove and release its journal_head. If we did
2139 * see that the buffer is not used by any transaction we also "logically"
2140 * decrement ->b_count.
2142 * We in fact take an additional increment on ->b_count as a convenience,
2143 * because the caller usually wants to do additional things with the bh
2144 * after calling here.
2145 * The caller of jbd2_journal_remove_journal_head() *must* run __brelse(bh) at some
2146 * time. Once the caller has run __brelse(), the buffer is eligible for
2147 * reaping by try_to_free_buffers().
2149 void jbd2_journal_remove_journal_head(struct buffer_head
*bh
)
2151 jbd_lock_bh_journal_head(bh
);
2152 __journal_remove_journal_head(bh
);
2153 jbd_unlock_bh_journal_head(bh
);
2157 * Drop a reference on the passed journal_head. If it fell to zero then try to
2158 * release the journal_head from the buffer_head.
2160 void jbd2_journal_put_journal_head(struct journal_head
*jh
)
2162 struct buffer_head
*bh
= jh2bh(jh
);
2164 jbd_lock_bh_journal_head(bh
);
2165 J_ASSERT_JH(jh
, jh
->b_jcount
> 0);
2167 if (!jh
->b_jcount
&& !jh
->b_transaction
) {
2168 __journal_remove_journal_head(bh
);
2171 jbd_unlock_bh_journal_head(bh
);
2175 * Initialize jbd inode head
2177 void jbd2_journal_init_jbd_inode(struct jbd2_inode
*jinode
, struct inode
*inode
)
2179 jinode
->i_transaction
= NULL
;
2180 jinode
->i_next_transaction
= NULL
;
2181 jinode
->i_vfs_inode
= inode
;
2182 jinode
->i_flags
= 0;
2183 INIT_LIST_HEAD(&jinode
->i_list
);
2187 * Function to be called before we start removing inode from memory (i.e.,
2188 * clear_inode() is a fine place to be called from). It removes inode from
2189 * transaction's lists.
2191 void jbd2_journal_release_jbd_inode(journal_t
*journal
,
2192 struct jbd2_inode
*jinode
)
2199 spin_lock(&journal
->j_list_lock
);
2200 /* Is commit writing out inode - we have to wait */
2201 if (jinode
->i_flags
& JI_COMMIT_RUNNING
) {
2202 wait_queue_head_t
*wq
;
2203 DEFINE_WAIT_BIT(wait
, &jinode
->i_flags
, __JI_COMMIT_RUNNING
);
2204 wq
= bit_waitqueue(&jinode
->i_flags
, __JI_COMMIT_RUNNING
);
2205 prepare_to_wait(wq
, &wait
.wait
, TASK_UNINTERRUPTIBLE
);
2206 spin_unlock(&journal
->j_list_lock
);
2208 finish_wait(wq
, &wait
.wait
);
2212 /* Do we need to wait for data writeback? */
2213 if (journal
->j_committing_transaction
== jinode
->i_transaction
)
2215 if (jinode
->i_transaction
) {
2216 list_del(&jinode
->i_list
);
2217 jinode
->i_transaction
= NULL
;
2219 spin_unlock(&journal
->j_list_lock
);
2225 #ifdef CONFIG_JBD2_DEBUG
2226 u8 jbd2_journal_enable_debug __read_mostly
;
2227 EXPORT_SYMBOL(jbd2_journal_enable_debug
);
2229 #define JBD2_DEBUG_NAME "jbd2-debug"
2231 static struct dentry
*jbd2_debugfs_dir
;
2232 static struct dentry
*jbd2_debug
;
2234 static void __init
jbd2_create_debugfs_entry(void)
2236 jbd2_debugfs_dir
= debugfs_create_dir("jbd2", NULL
);
2237 if (jbd2_debugfs_dir
)
2238 jbd2_debug
= debugfs_create_u8(JBD2_DEBUG_NAME
, S_IRUGO
,
2240 &jbd2_journal_enable_debug
);
2243 static void __exit
jbd2_remove_debugfs_entry(void)
2245 debugfs_remove(jbd2_debug
);
2246 debugfs_remove(jbd2_debugfs_dir
);
2251 static void __init
jbd2_create_debugfs_entry(void)
2255 static void __exit
jbd2_remove_debugfs_entry(void)
2261 #ifdef CONFIG_PROC_FS
2263 #define JBD2_STATS_PROC_NAME "fs/jbd2"
2265 static void __init
jbd2_create_jbd_stats_proc_entry(void)
2267 proc_jbd2_stats
= proc_mkdir(JBD2_STATS_PROC_NAME
, NULL
);
2270 static void __exit
jbd2_remove_jbd_stats_proc_entry(void)
2272 if (proc_jbd2_stats
)
2273 remove_proc_entry(JBD2_STATS_PROC_NAME
, NULL
);
2278 #define jbd2_create_jbd_stats_proc_entry() do {} while (0)
2279 #define jbd2_remove_jbd_stats_proc_entry() do {} while (0)
2283 struct kmem_cache
*jbd2_handle_cache
;
2285 static int __init
journal_init_handle_cache(void)
2287 jbd2_handle_cache
= kmem_cache_create("jbd2_journal_handle",
2290 SLAB_TEMPORARY
, /* flags */
2292 if (jbd2_handle_cache
== NULL
) {
2293 printk(KERN_EMERG
"JBD: failed to create handle cache\n");
2299 static void jbd2_journal_destroy_handle_cache(void)
2301 if (jbd2_handle_cache
)
2302 kmem_cache_destroy(jbd2_handle_cache
);
2306 * Module startup and shutdown
2309 static int __init
journal_init_caches(void)
2313 ret
= jbd2_journal_init_revoke_caches();
2315 ret
= journal_init_jbd2_journal_head_cache();
2317 ret
= journal_init_handle_cache();
2321 static void jbd2_journal_destroy_caches(void)
2323 jbd2_journal_destroy_revoke_caches();
2324 jbd2_journal_destroy_jbd2_journal_head_cache();
2325 jbd2_journal_destroy_handle_cache();
2328 static int __init
journal_init(void)
2332 BUILD_BUG_ON(sizeof(struct journal_superblock_s
) != 1024);
2334 ret
= journal_init_caches();
2336 jbd2_create_debugfs_entry();
2337 jbd2_create_jbd_stats_proc_entry();
2339 jbd2_journal_destroy_caches();
2344 static void __exit
journal_exit(void)
2346 #ifdef CONFIG_JBD2_DEBUG
2347 int n
= atomic_read(&nr_journal_heads
);
2349 printk(KERN_EMERG
"JBD: leaked %d journal_heads!\n", n
);
2351 jbd2_remove_debugfs_entry();
2352 jbd2_remove_jbd_stats_proc_entry();
2353 jbd2_journal_destroy_caches();
2356 MODULE_LICENSE("GPL");
2357 module_init(journal_init
);
2358 module_exit(journal_exit
);