1 // SPDX-License-Identifier: GPL-2.0+
3 * linux/fs/jbd2/journal.c
5 * Written by Stephen C. Tweedie <sct@redhat.com>, 1998
7 * Copyright 1998 Red Hat corp --- All Rights Reserved
9 * Generic filesystem journal-writing code; part of the ext2fs
12 * This file manages journals: areas of disk reserved for logging
13 * transactional updates. This includes the kernel journaling thread
14 * which is responsible for scheduling updates to the log.
16 * We do not actually manage the physical storage of the journal in this
17 * file: that is left to a per-journal policy function, which allows us
18 * to store the journal within a filesystem-specified area for ext2
19 * journaling (ext2 can use a reserved inode for storing the log).
22 #include <linux/module.h>
23 #include <linux/time.h>
25 #include <linux/jbd2.h>
26 #include <linux/errno.h>
27 #include <linux/slab.h>
28 #include <linux/init.h>
30 #include <linux/freezer.h>
31 #include <linux/pagemap.h>
32 #include <linux/kthread.h>
33 #include <linux/poison.h>
34 #include <linux/proc_fs.h>
35 #include <linux/seq_file.h>
36 #include <linux/math64.h>
37 #include <linux/hash.h>
38 #include <linux/log2.h>
39 #include <linux/vmalloc.h>
40 #include <linux/backing-dev.h>
41 #include <linux/bitops.h>
42 #include <linux/ratelimit.h>
43 #include <linux/sched/mm.h>
45 #define CREATE_TRACE_POINTS
46 #include <trace/events/jbd2.h>
48 #include <linux/uaccess.h>
51 #ifdef CONFIG_JBD2_DEBUG
52 ushort jbd2_journal_enable_debug __read_mostly
;
53 EXPORT_SYMBOL(jbd2_journal_enable_debug
);
55 module_param_named(jbd2_debug
, jbd2_journal_enable_debug
, ushort
, 0644);
56 MODULE_PARM_DESC(jbd2_debug
, "Debugging level for jbd2");
59 EXPORT_SYMBOL(jbd2_journal_extend
);
60 EXPORT_SYMBOL(jbd2_journal_stop
);
61 EXPORT_SYMBOL(jbd2_journal_lock_updates
);
62 EXPORT_SYMBOL(jbd2_journal_unlock_updates
);
63 EXPORT_SYMBOL(jbd2_journal_get_write_access
);
64 EXPORT_SYMBOL(jbd2_journal_get_create_access
);
65 EXPORT_SYMBOL(jbd2_journal_get_undo_access
);
66 EXPORT_SYMBOL(jbd2_journal_set_triggers
);
67 EXPORT_SYMBOL(jbd2_journal_dirty_metadata
);
68 EXPORT_SYMBOL(jbd2_journal_forget
);
69 EXPORT_SYMBOL(jbd2_journal_flush
);
70 EXPORT_SYMBOL(jbd2_journal_revoke
);
72 EXPORT_SYMBOL(jbd2_journal_init_dev
);
73 EXPORT_SYMBOL(jbd2_journal_init_inode
);
74 EXPORT_SYMBOL(jbd2_journal_check_used_features
);
75 EXPORT_SYMBOL(jbd2_journal_check_available_features
);
76 EXPORT_SYMBOL(jbd2_journal_set_features
);
77 EXPORT_SYMBOL(jbd2_journal_load
);
78 EXPORT_SYMBOL(jbd2_journal_destroy
);
79 EXPORT_SYMBOL(jbd2_journal_abort
);
80 EXPORT_SYMBOL(jbd2_journal_errno
);
81 EXPORT_SYMBOL(jbd2_journal_ack_err
);
82 EXPORT_SYMBOL(jbd2_journal_clear_err
);
83 EXPORT_SYMBOL(jbd2_log_wait_commit
);
84 EXPORT_SYMBOL(jbd2_log_start_commit
);
85 EXPORT_SYMBOL(jbd2_journal_start_commit
);
86 EXPORT_SYMBOL(jbd2_journal_force_commit_nested
);
87 EXPORT_SYMBOL(jbd2_journal_wipe
);
88 EXPORT_SYMBOL(jbd2_journal_blocks_per_page
);
89 EXPORT_SYMBOL(jbd2_journal_invalidatepage
);
90 EXPORT_SYMBOL(jbd2_journal_try_to_free_buffers
);
91 EXPORT_SYMBOL(jbd2_journal_force_commit
);
92 EXPORT_SYMBOL(jbd2_journal_inode_ranged_write
);
93 EXPORT_SYMBOL(jbd2_journal_inode_ranged_wait
);
94 EXPORT_SYMBOL(jbd2_journal_init_jbd_inode
);
95 EXPORT_SYMBOL(jbd2_journal_release_jbd_inode
);
96 EXPORT_SYMBOL(jbd2_journal_begin_ordered_truncate
);
97 EXPORT_SYMBOL(jbd2_inode_cache
);
99 static int jbd2_journal_create_slab(size_t slab_size
);
101 #ifdef CONFIG_JBD2_DEBUG
102 void __jbd2_debug(int level
, const char *file
, const char *func
,
103 unsigned int line
, const char *fmt
, ...)
105 struct va_format vaf
;
108 if (level
> jbd2_journal_enable_debug
)
113 printk(KERN_DEBUG
"%s: (%s, %u): %pV", file
, func
, line
, &vaf
);
116 EXPORT_SYMBOL(__jbd2_debug
);
119 /* Checksumming functions */
120 static int jbd2_verify_csum_type(journal_t
*j
, journal_superblock_t
*sb
)
122 if (!jbd2_journal_has_csum_v2or3_feature(j
))
125 return sb
->s_checksum_type
== JBD2_CRC32C_CHKSUM
;
128 static __be32
jbd2_superblock_csum(journal_t
*j
, journal_superblock_t
*sb
)
133 old_csum
= sb
->s_checksum
;
135 csum
= jbd2_chksum(j
, ~0, (char *)sb
, sizeof(journal_superblock_t
));
136 sb
->s_checksum
= old_csum
;
138 return cpu_to_be32(csum
);
142 * Helper function used to manage commit timeouts
145 static void commit_timeout(struct timer_list
*t
)
147 journal_t
*journal
= from_timer(journal
, t
, j_commit_timer
);
149 wake_up_process(journal
->j_task
);
153 * kjournald2: The main thread function used to manage a logging device
156 * This kernel thread is responsible for two things:
158 * 1) COMMIT: Every so often we need to commit the current state of the
159 * filesystem to disk. The journal thread is responsible for writing
160 * all of the metadata buffers to disk.
162 * 2) CHECKPOINT: We cannot reuse a used section of the log file until all
163 * of the data in that part of the log has been rewritten elsewhere on
164 * the disk. Flushing these old buffers to reclaim space in the log is
165 * known as checkpointing, and this thread is responsible for that job.
168 static int kjournald2(void *arg
)
170 journal_t
*journal
= arg
;
171 transaction_t
*transaction
;
174 * Set up an interval timer which can be used to trigger a commit wakeup
175 * after the commit interval expires
177 timer_setup(&journal
->j_commit_timer
, commit_timeout
, 0);
181 /* Record that the journal thread is running */
182 journal
->j_task
= current
;
183 wake_up(&journal
->j_wait_done_commit
);
186 * Make sure that no allocations from this kernel thread will ever
187 * recurse to the fs layer because we are responsible for the
188 * transaction commit and any fs involvement might get stuck waiting for
191 memalloc_nofs_save();
194 * And now, wait forever for commit wakeup events.
196 write_lock(&journal
->j_state_lock
);
199 if (journal
->j_flags
& JBD2_UNMOUNT
)
202 jbd_debug(1, "commit_sequence=%u, commit_request=%u\n",
203 journal
->j_commit_sequence
, journal
->j_commit_request
);
205 if (journal
->j_commit_sequence
!= journal
->j_commit_request
) {
206 jbd_debug(1, "OK, requests differ\n");
207 write_unlock(&journal
->j_state_lock
);
208 del_timer_sync(&journal
->j_commit_timer
);
209 jbd2_journal_commit_transaction(journal
);
210 write_lock(&journal
->j_state_lock
);
214 wake_up(&journal
->j_wait_done_commit
);
215 if (freezing(current
)) {
217 * The simpler the better. Flushing journal isn't a
218 * good idea, because that depends on threads that may
219 * be already stopped.
221 jbd_debug(1, "Now suspending kjournald2\n");
222 write_unlock(&journal
->j_state_lock
);
224 write_lock(&journal
->j_state_lock
);
227 * We assume on resume that commits are already there,
231 int should_sleep
= 1;
233 prepare_to_wait(&journal
->j_wait_commit
, &wait
,
235 if (journal
->j_commit_sequence
!= journal
->j_commit_request
)
237 transaction
= journal
->j_running_transaction
;
238 if (transaction
&& time_after_eq(jiffies
,
239 transaction
->t_expires
))
241 if (journal
->j_flags
& JBD2_UNMOUNT
)
244 write_unlock(&journal
->j_state_lock
);
246 write_lock(&journal
->j_state_lock
);
248 finish_wait(&journal
->j_wait_commit
, &wait
);
251 jbd_debug(1, "kjournald2 wakes\n");
254 * Were we woken up by a commit wakeup event?
256 transaction
= journal
->j_running_transaction
;
257 if (transaction
&& time_after_eq(jiffies
, transaction
->t_expires
)) {
258 journal
->j_commit_request
= transaction
->t_tid
;
259 jbd_debug(1, "woke because of timeout\n");
264 del_timer_sync(&journal
->j_commit_timer
);
265 journal
->j_task
= NULL
;
266 wake_up(&journal
->j_wait_done_commit
);
267 jbd_debug(1, "Journal thread exiting.\n");
268 write_unlock(&journal
->j_state_lock
);
272 static int jbd2_journal_start_thread(journal_t
*journal
)
274 struct task_struct
*t
;
276 t
= kthread_run(kjournald2
, journal
, "jbd2/%s",
281 wait_event(journal
->j_wait_done_commit
, journal
->j_task
!= NULL
);
285 static void journal_kill_thread(journal_t
*journal
)
287 write_lock(&journal
->j_state_lock
);
288 journal
->j_flags
|= JBD2_UNMOUNT
;
290 while (journal
->j_task
) {
291 write_unlock(&journal
->j_state_lock
);
292 wake_up(&journal
->j_wait_commit
);
293 wait_event(journal
->j_wait_done_commit
, journal
->j_task
== NULL
);
294 write_lock(&journal
->j_state_lock
);
296 write_unlock(&journal
->j_state_lock
);
300 * jbd2_journal_write_metadata_buffer: write a metadata buffer to the journal.
302 * Writes a metadata buffer to a given disk block. The actual IO is not
303 * performed but a new buffer_head is constructed which labels the data
304 * to be written with the correct destination disk block.
306 * Any magic-number escaping which needs to be done will cause a
307 * copy-out here. If the buffer happens to start with the
308 * JBD2_MAGIC_NUMBER, then we can't write it to the log directly: the
309 * magic number is only written to the log for descripter blocks. In
310 * this case, we copy the data and replace the first word with 0, and we
311 * return a result code which indicates that this buffer needs to be
312 * marked as an escaped buffer in the corresponding log descriptor
313 * block. The missing word can then be restored when the block is read
316 * If the source buffer has already been modified by a new transaction
317 * since we took the last commit snapshot, we use the frozen copy of
318 * that data for IO. If we end up using the existing buffer_head's data
319 * for the write, then we have to make sure nobody modifies it while the
320 * IO is in progress. do_get_write_access() handles this.
322 * The function returns a pointer to the buffer_head to be used for IO.
330 * Bit 0 set == escape performed on the data
331 * Bit 1 set == buffer copy-out performed (kfree the data after IO)
334 int jbd2_journal_write_metadata_buffer(transaction_t
*transaction
,
335 struct journal_head
*jh_in
,
336 struct buffer_head
**bh_out
,
339 int need_copy_out
= 0;
340 int done_copy_out
= 0;
343 struct buffer_head
*new_bh
;
344 struct page
*new_page
;
345 unsigned int new_offset
;
346 struct buffer_head
*bh_in
= jh2bh(jh_in
);
347 journal_t
*journal
= transaction
->t_journal
;
350 * The buffer really shouldn't be locked: only the current committing
351 * transaction is allowed to write it, so nobody else is allowed
354 * akpm: except if we're journalling data, and write() output is
355 * also part of a shared mapping, and another thread has
356 * decided to launch a writepage() against this buffer.
358 J_ASSERT_BH(bh_in
, buffer_jbddirty(bh_in
));
360 new_bh
= alloc_buffer_head(GFP_NOFS
|__GFP_NOFAIL
);
362 /* keep subsequent assertions sane */
363 atomic_set(&new_bh
->b_count
, 1);
365 spin_lock(&jh_in
->b_state_lock
);
368 * If a new transaction has already done a buffer copy-out, then
369 * we use that version of the data for the commit.
371 if (jh_in
->b_frozen_data
) {
373 new_page
= virt_to_page(jh_in
->b_frozen_data
);
374 new_offset
= offset_in_page(jh_in
->b_frozen_data
);
376 new_page
= jh2bh(jh_in
)->b_page
;
377 new_offset
= offset_in_page(jh2bh(jh_in
)->b_data
);
380 mapped_data
= kmap_atomic(new_page
);
382 * Fire data frozen trigger if data already wasn't frozen. Do this
383 * before checking for escaping, as the trigger may modify the magic
384 * offset. If a copy-out happens afterwards, it will have the correct
385 * data in the buffer.
388 jbd2_buffer_frozen_trigger(jh_in
, mapped_data
+ new_offset
,
394 if (*((__be32
*)(mapped_data
+ new_offset
)) ==
395 cpu_to_be32(JBD2_MAGIC_NUMBER
)) {
399 kunmap_atomic(mapped_data
);
402 * Do we need to do a data copy?
404 if (need_copy_out
&& !done_copy_out
) {
407 spin_unlock(&jh_in
->b_state_lock
);
408 tmp
= jbd2_alloc(bh_in
->b_size
, GFP_NOFS
);
413 spin_lock(&jh_in
->b_state_lock
);
414 if (jh_in
->b_frozen_data
) {
415 jbd2_free(tmp
, bh_in
->b_size
);
419 jh_in
->b_frozen_data
= tmp
;
420 mapped_data
= kmap_atomic(new_page
);
421 memcpy(tmp
, mapped_data
+ new_offset
, bh_in
->b_size
);
422 kunmap_atomic(mapped_data
);
424 new_page
= virt_to_page(tmp
);
425 new_offset
= offset_in_page(tmp
);
429 * This isn't strictly necessary, as we're using frozen
430 * data for the escaping, but it keeps consistency with
431 * b_frozen_data usage.
433 jh_in
->b_frozen_triggers
= jh_in
->b_triggers
;
437 * Did we need to do an escaping? Now we've done all the
438 * copying, we can finally do so.
441 mapped_data
= kmap_atomic(new_page
);
442 *((unsigned int *)(mapped_data
+ new_offset
)) = 0;
443 kunmap_atomic(mapped_data
);
446 set_bh_page(new_bh
, new_page
, new_offset
);
447 new_bh
->b_size
= bh_in
->b_size
;
448 new_bh
->b_bdev
= journal
->j_dev
;
449 new_bh
->b_blocknr
= blocknr
;
450 new_bh
->b_private
= bh_in
;
451 set_buffer_mapped(new_bh
);
452 set_buffer_dirty(new_bh
);
457 * The to-be-written buffer needs to get moved to the io queue,
458 * and the original buffer whose contents we are shadowing or
459 * copying is moved to the transaction's shadow queue.
461 JBUFFER_TRACE(jh_in
, "file as BJ_Shadow");
462 spin_lock(&journal
->j_list_lock
);
463 __jbd2_journal_file_buffer(jh_in
, transaction
, BJ_Shadow
);
464 spin_unlock(&journal
->j_list_lock
);
465 set_buffer_shadow(bh_in
);
466 spin_unlock(&jh_in
->b_state_lock
);
468 return do_escape
| (done_copy_out
<< 1);
472 * Allocation code for the journal file. Manage the space left in the
473 * journal, so that we can begin checkpointing when appropriate.
477 * Called with j_state_lock locked for writing.
478 * Returns true if a transaction commit was started.
480 int __jbd2_log_start_commit(journal_t
*journal
, tid_t target
)
482 /* Return if the txn has already requested to be committed */
483 if (journal
->j_commit_request
== target
)
487 * The only transaction we can possibly wait upon is the
488 * currently running transaction (if it exists). Otherwise,
489 * the target tid must be an old one.
491 if (journal
->j_running_transaction
&&
492 journal
->j_running_transaction
->t_tid
== target
) {
494 * We want a new commit: OK, mark the request and wakeup the
495 * commit thread. We do _not_ do the commit ourselves.
498 journal
->j_commit_request
= target
;
499 jbd_debug(1, "JBD2: requesting commit %u/%u\n",
500 journal
->j_commit_request
,
501 journal
->j_commit_sequence
);
502 journal
->j_running_transaction
->t_requested
= jiffies
;
503 wake_up(&journal
->j_wait_commit
);
505 } else if (!tid_geq(journal
->j_commit_request
, target
))
506 /* This should never happen, but if it does, preserve
507 the evidence before kjournald goes into a loop and
508 increments j_commit_sequence beyond all recognition. */
509 WARN_ONCE(1, "JBD2: bad log_start_commit: %u %u %u %u\n",
510 journal
->j_commit_request
,
511 journal
->j_commit_sequence
,
512 target
, journal
->j_running_transaction
?
513 journal
->j_running_transaction
->t_tid
: 0);
517 int jbd2_log_start_commit(journal_t
*journal
, tid_t tid
)
521 write_lock(&journal
->j_state_lock
);
522 ret
= __jbd2_log_start_commit(journal
, tid
);
523 write_unlock(&journal
->j_state_lock
);
528 * Force and wait any uncommitted transactions. We can only force the running
529 * transaction if we don't have an active handle, otherwise, we will deadlock.
530 * Returns: <0 in case of error,
531 * 0 if nothing to commit,
532 * 1 if transaction was successfully committed.
534 static int __jbd2_journal_force_commit(journal_t
*journal
)
536 transaction_t
*transaction
= NULL
;
538 int need_to_start
= 0, ret
= 0;
540 read_lock(&journal
->j_state_lock
);
541 if (journal
->j_running_transaction
&& !current
->journal_info
) {
542 transaction
= journal
->j_running_transaction
;
543 if (!tid_geq(journal
->j_commit_request
, transaction
->t_tid
))
545 } else if (journal
->j_committing_transaction
)
546 transaction
= journal
->j_committing_transaction
;
549 /* Nothing to commit */
550 read_unlock(&journal
->j_state_lock
);
553 tid
= transaction
->t_tid
;
554 read_unlock(&journal
->j_state_lock
);
556 jbd2_log_start_commit(journal
, tid
);
557 ret
= jbd2_log_wait_commit(journal
, tid
);
565 * Force and wait upon a commit if the calling process is not within
566 * transaction. This is used for forcing out undo-protected data which contains
567 * bitmaps, when the fs is running out of space.
569 * @journal: journal to force
570 * Returns true if progress was made.
572 int jbd2_journal_force_commit_nested(journal_t
*journal
)
576 ret
= __jbd2_journal_force_commit(journal
);
581 * int journal_force_commit() - force any uncommitted transactions
582 * @journal: journal to force
584 * Caller want unconditional commit. We can only force the running transaction
585 * if we don't have an active handle, otherwise, we will deadlock.
587 int jbd2_journal_force_commit(journal_t
*journal
)
591 J_ASSERT(!current
->journal_info
);
592 ret
= __jbd2_journal_force_commit(journal
);
599 * Start a commit of the current running transaction (if any). Returns true
600 * if a transaction is going to be committed (or is currently already
601 * committing), and fills its tid in at *ptid
603 int jbd2_journal_start_commit(journal_t
*journal
, tid_t
*ptid
)
607 write_lock(&journal
->j_state_lock
);
608 if (journal
->j_running_transaction
) {
609 tid_t tid
= journal
->j_running_transaction
->t_tid
;
611 __jbd2_log_start_commit(journal
, tid
);
612 /* There's a running transaction and we've just made sure
613 * it's commit has been scheduled. */
617 } else if (journal
->j_committing_transaction
) {
619 * If commit has been started, then we have to wait for
620 * completion of that transaction.
623 *ptid
= journal
->j_committing_transaction
->t_tid
;
626 write_unlock(&journal
->j_state_lock
);
631 * Return 1 if a given transaction has not yet sent barrier request
632 * connected with a transaction commit. If 0 is returned, transaction
633 * may or may not have sent the barrier. Used to avoid sending barrier
634 * twice in common cases.
636 int jbd2_trans_will_send_data_barrier(journal_t
*journal
, tid_t tid
)
639 transaction_t
*commit_trans
;
641 if (!(journal
->j_flags
& JBD2_BARRIER
))
643 read_lock(&journal
->j_state_lock
);
644 /* Transaction already committed? */
645 if (tid_geq(journal
->j_commit_sequence
, tid
))
647 commit_trans
= journal
->j_committing_transaction
;
648 if (!commit_trans
|| commit_trans
->t_tid
!= tid
) {
653 * Transaction is being committed and we already proceeded to
654 * submitting a flush to fs partition?
656 if (journal
->j_fs_dev
!= journal
->j_dev
) {
657 if (!commit_trans
->t_need_data_flush
||
658 commit_trans
->t_state
>= T_COMMIT_DFLUSH
)
661 if (commit_trans
->t_state
>= T_COMMIT_JFLUSH
)
666 read_unlock(&journal
->j_state_lock
);
669 EXPORT_SYMBOL(jbd2_trans_will_send_data_barrier
);
672 * Wait for a specified commit to complete.
673 * The caller may not hold the journal lock.
675 int jbd2_log_wait_commit(journal_t
*journal
, tid_t tid
)
679 read_lock(&journal
->j_state_lock
);
680 #ifdef CONFIG_PROVE_LOCKING
682 * Some callers make sure transaction is already committing and in that
683 * case we cannot block on open handles anymore. So don't warn in that
686 if (tid_gt(tid
, journal
->j_commit_sequence
) &&
687 (!journal
->j_committing_transaction
||
688 journal
->j_committing_transaction
->t_tid
!= tid
)) {
689 read_unlock(&journal
->j_state_lock
);
690 jbd2_might_wait_for_commit(journal
);
691 read_lock(&journal
->j_state_lock
);
694 #ifdef CONFIG_JBD2_DEBUG
695 if (!tid_geq(journal
->j_commit_request
, tid
)) {
697 "%s: error: j_commit_request=%u, tid=%u\n",
698 __func__
, journal
->j_commit_request
, tid
);
701 while (tid_gt(tid
, journal
->j_commit_sequence
)) {
702 jbd_debug(1, "JBD2: want %u, j_commit_sequence=%u\n",
703 tid
, journal
->j_commit_sequence
);
704 read_unlock(&journal
->j_state_lock
);
705 wake_up(&journal
->j_wait_commit
);
706 wait_event(journal
->j_wait_done_commit
,
707 !tid_gt(tid
, journal
->j_commit_sequence
));
708 read_lock(&journal
->j_state_lock
);
710 read_unlock(&journal
->j_state_lock
);
712 if (unlikely(is_journal_aborted(journal
)))
717 /* Return 1 when transaction with given tid has already committed. */
718 int jbd2_transaction_committed(journal_t
*journal
, tid_t tid
)
722 read_lock(&journal
->j_state_lock
);
723 if (journal
->j_running_transaction
&&
724 journal
->j_running_transaction
->t_tid
== tid
)
726 if (journal
->j_committing_transaction
&&
727 journal
->j_committing_transaction
->t_tid
== tid
)
729 read_unlock(&journal
->j_state_lock
);
732 EXPORT_SYMBOL(jbd2_transaction_committed
);
735 * When this function returns the transaction corresponding to tid
736 * will be completed. If the transaction has currently running, start
737 * committing that transaction before waiting for it to complete. If
738 * the transaction id is stale, it is by definition already completed,
739 * so just return SUCCESS.
741 int jbd2_complete_transaction(journal_t
*journal
, tid_t tid
)
743 int need_to_wait
= 1;
745 read_lock(&journal
->j_state_lock
);
746 if (journal
->j_running_transaction
&&
747 journal
->j_running_transaction
->t_tid
== tid
) {
748 if (journal
->j_commit_request
!= tid
) {
749 /* transaction not yet started, so request it */
750 read_unlock(&journal
->j_state_lock
);
751 jbd2_log_start_commit(journal
, tid
);
754 } else if (!(journal
->j_committing_transaction
&&
755 journal
->j_committing_transaction
->t_tid
== tid
))
757 read_unlock(&journal
->j_state_lock
);
761 return jbd2_log_wait_commit(journal
, tid
);
763 EXPORT_SYMBOL(jbd2_complete_transaction
);
766 * Log buffer allocation routines:
769 int jbd2_journal_next_log_block(journal_t
*journal
, unsigned long long *retp
)
771 unsigned long blocknr
;
773 write_lock(&journal
->j_state_lock
);
774 J_ASSERT(journal
->j_free
> 1);
776 blocknr
= journal
->j_head
;
779 if (journal
->j_head
== journal
->j_last
)
780 journal
->j_head
= journal
->j_first
;
781 write_unlock(&journal
->j_state_lock
);
782 return jbd2_journal_bmap(journal
, blocknr
, retp
);
786 * Conversion of logical to physical block numbers for the journal
788 * On external journals the journal blocks are identity-mapped, so
789 * this is a no-op. If needed, we can use j_blk_offset - everything is
792 int jbd2_journal_bmap(journal_t
*journal
, unsigned long blocknr
,
793 unsigned long long *retp
)
796 unsigned long long ret
;
798 if (journal
->j_inode
) {
799 ret
= bmap(journal
->j_inode
, blocknr
);
803 printk(KERN_ALERT
"%s: journal block not found "
804 "at offset %lu on %s\n",
805 __func__
, blocknr
, journal
->j_devname
);
807 jbd2_journal_abort(journal
, err
);
810 *retp
= blocknr
; /* +journal->j_blk_offset */
816 * We play buffer_head aliasing tricks to write data/metadata blocks to
817 * the journal without copying their contents, but for journal
818 * descriptor blocks we do need to generate bona fide buffers.
820 * After the caller of jbd2_journal_get_descriptor_buffer() has finished modifying
821 * the buffer's contents they really should run flush_dcache_page(bh->b_page).
822 * But we don't bother doing that, so there will be coherency problems with
823 * mmaps of blockdevs which hold live JBD-controlled filesystems.
826 jbd2_journal_get_descriptor_buffer(transaction_t
*transaction
, int type
)
828 journal_t
*journal
= transaction
->t_journal
;
829 struct buffer_head
*bh
;
830 unsigned long long blocknr
;
831 journal_header_t
*header
;
834 err
= jbd2_journal_next_log_block(journal
, &blocknr
);
839 bh
= __getblk(journal
->j_dev
, blocknr
, journal
->j_blocksize
);
842 atomic_dec(&transaction
->t_outstanding_credits
);
844 memset(bh
->b_data
, 0, journal
->j_blocksize
);
845 header
= (journal_header_t
*)bh
->b_data
;
846 header
->h_magic
= cpu_to_be32(JBD2_MAGIC_NUMBER
);
847 header
->h_blocktype
= cpu_to_be32(type
);
848 header
->h_sequence
= cpu_to_be32(transaction
->t_tid
);
849 set_buffer_uptodate(bh
);
851 BUFFER_TRACE(bh
, "return this buffer");
855 void jbd2_descriptor_block_csum_set(journal_t
*j
, struct buffer_head
*bh
)
857 struct jbd2_journal_block_tail
*tail
;
860 if (!jbd2_journal_has_csum_v2or3(j
))
863 tail
= (struct jbd2_journal_block_tail
*)(bh
->b_data
+ j
->j_blocksize
-
864 sizeof(struct jbd2_journal_block_tail
));
865 tail
->t_checksum
= 0;
866 csum
= jbd2_chksum(j
, j
->j_csum_seed
, bh
->b_data
, j
->j_blocksize
);
867 tail
->t_checksum
= cpu_to_be32(csum
);
871 * Return tid of the oldest transaction in the journal and block in the journal
872 * where the transaction starts.
874 * If the journal is now empty, return which will be the next transaction ID
875 * we will write and where will that transaction start.
877 * The return value is 0 if journal tail cannot be pushed any further, 1 if
880 int jbd2_journal_get_log_tail(journal_t
*journal
, tid_t
*tid
,
881 unsigned long *block
)
883 transaction_t
*transaction
;
886 read_lock(&journal
->j_state_lock
);
887 spin_lock(&journal
->j_list_lock
);
888 transaction
= journal
->j_checkpoint_transactions
;
890 *tid
= transaction
->t_tid
;
891 *block
= transaction
->t_log_start
;
892 } else if ((transaction
= journal
->j_committing_transaction
) != NULL
) {
893 *tid
= transaction
->t_tid
;
894 *block
= transaction
->t_log_start
;
895 } else if ((transaction
= journal
->j_running_transaction
) != NULL
) {
896 *tid
= transaction
->t_tid
;
897 *block
= journal
->j_head
;
899 *tid
= journal
->j_transaction_sequence
;
900 *block
= journal
->j_head
;
902 ret
= tid_gt(*tid
, journal
->j_tail_sequence
);
903 spin_unlock(&journal
->j_list_lock
);
904 read_unlock(&journal
->j_state_lock
);
910 * Update information in journal structure and in on disk journal superblock
911 * about log tail. This function does not check whether information passed in
912 * really pushes log tail further. It's responsibility of the caller to make
913 * sure provided log tail information is valid (e.g. by holding
914 * j_checkpoint_mutex all the time between computing log tail and calling this
915 * function as is the case with jbd2_cleanup_journal_tail()).
917 * Requires j_checkpoint_mutex
919 int __jbd2_update_log_tail(journal_t
*journal
, tid_t tid
, unsigned long block
)
924 BUG_ON(!mutex_is_locked(&journal
->j_checkpoint_mutex
));
927 * We cannot afford for write to remain in drive's caches since as
928 * soon as we update j_tail, next transaction can start reusing journal
929 * space and if we lose sb update during power failure we'd replay
930 * old transaction with possibly newly overwritten data.
932 ret
= jbd2_journal_update_sb_log_tail(journal
, tid
, block
,
937 write_lock(&journal
->j_state_lock
);
938 freed
= block
- journal
->j_tail
;
939 if (block
< journal
->j_tail
)
940 freed
+= journal
->j_last
- journal
->j_first
;
942 trace_jbd2_update_log_tail(journal
, tid
, block
, freed
);
944 "Cleaning journal tail from %u to %u (offset %lu), "
946 journal
->j_tail_sequence
, tid
, block
, freed
);
948 journal
->j_free
+= freed
;
949 journal
->j_tail_sequence
= tid
;
950 journal
->j_tail
= block
;
951 write_unlock(&journal
->j_state_lock
);
958 * This is a variation of __jbd2_update_log_tail which checks for validity of
959 * provided log tail and locks j_checkpoint_mutex. So it is safe against races
960 * with other threads updating log tail.
962 void jbd2_update_log_tail(journal_t
*journal
, tid_t tid
, unsigned long block
)
964 mutex_lock_io(&journal
->j_checkpoint_mutex
);
965 if (tid_gt(tid
, journal
->j_tail_sequence
))
966 __jbd2_update_log_tail(journal
, tid
, block
);
967 mutex_unlock(&journal
->j_checkpoint_mutex
);
970 struct jbd2_stats_proc_session
{
972 struct transaction_stats_s
*stats
;
977 static void *jbd2_seq_info_start(struct seq_file
*seq
, loff_t
*pos
)
979 return *pos
? NULL
: SEQ_START_TOKEN
;
982 static void *jbd2_seq_info_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
988 static int jbd2_seq_info_show(struct seq_file
*seq
, void *v
)
990 struct jbd2_stats_proc_session
*s
= seq
->private;
992 if (v
!= SEQ_START_TOKEN
)
994 seq_printf(seq
, "%lu transactions (%lu requested), "
995 "each up to %u blocks\n",
996 s
->stats
->ts_tid
, s
->stats
->ts_requested
,
997 s
->journal
->j_max_transaction_buffers
);
998 if (s
->stats
->ts_tid
== 0)
1000 seq_printf(seq
, "average: \n %ums waiting for transaction\n",
1001 jiffies_to_msecs(s
->stats
->run
.rs_wait
/ s
->stats
->ts_tid
));
1002 seq_printf(seq
, " %ums request delay\n",
1003 (s
->stats
->ts_requested
== 0) ? 0 :
1004 jiffies_to_msecs(s
->stats
->run
.rs_request_delay
/
1005 s
->stats
->ts_requested
));
1006 seq_printf(seq
, " %ums running transaction\n",
1007 jiffies_to_msecs(s
->stats
->run
.rs_running
/ s
->stats
->ts_tid
));
1008 seq_printf(seq
, " %ums transaction was being locked\n",
1009 jiffies_to_msecs(s
->stats
->run
.rs_locked
/ s
->stats
->ts_tid
));
1010 seq_printf(seq
, " %ums flushing data (in ordered mode)\n",
1011 jiffies_to_msecs(s
->stats
->run
.rs_flushing
/ s
->stats
->ts_tid
));
1012 seq_printf(seq
, " %ums logging transaction\n",
1013 jiffies_to_msecs(s
->stats
->run
.rs_logging
/ s
->stats
->ts_tid
));
1014 seq_printf(seq
, " %lluus average transaction commit time\n",
1015 div_u64(s
->journal
->j_average_commit_time
, 1000));
1016 seq_printf(seq
, " %lu handles per transaction\n",
1017 s
->stats
->run
.rs_handle_count
/ s
->stats
->ts_tid
);
1018 seq_printf(seq
, " %lu blocks per transaction\n",
1019 s
->stats
->run
.rs_blocks
/ s
->stats
->ts_tid
);
1020 seq_printf(seq
, " %lu logged blocks per transaction\n",
1021 s
->stats
->run
.rs_blocks_logged
/ s
->stats
->ts_tid
);
1025 static void jbd2_seq_info_stop(struct seq_file
*seq
, void *v
)
1029 static const struct seq_operations jbd2_seq_info_ops
= {
1030 .start
= jbd2_seq_info_start
,
1031 .next
= jbd2_seq_info_next
,
1032 .stop
= jbd2_seq_info_stop
,
1033 .show
= jbd2_seq_info_show
,
1036 static int jbd2_seq_info_open(struct inode
*inode
, struct file
*file
)
1038 journal_t
*journal
= PDE_DATA(inode
);
1039 struct jbd2_stats_proc_session
*s
;
1042 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
1045 size
= sizeof(struct transaction_stats_s
);
1046 s
->stats
= kmalloc(size
, GFP_KERNEL
);
1047 if (s
->stats
== NULL
) {
1051 spin_lock(&journal
->j_history_lock
);
1052 memcpy(s
->stats
, &journal
->j_stats
, size
);
1053 s
->journal
= journal
;
1054 spin_unlock(&journal
->j_history_lock
);
1056 rc
= seq_open(file
, &jbd2_seq_info_ops
);
1058 struct seq_file
*m
= file
->private_data
;
1068 static int jbd2_seq_info_release(struct inode
*inode
, struct file
*file
)
1070 struct seq_file
*seq
= file
->private_data
;
1071 struct jbd2_stats_proc_session
*s
= seq
->private;
1074 return seq_release(inode
, file
);
1077 static const struct proc_ops jbd2_info_proc_ops
= {
1078 .proc_open
= jbd2_seq_info_open
,
1079 .proc_read
= seq_read
,
1080 .proc_lseek
= seq_lseek
,
1081 .proc_release
= jbd2_seq_info_release
,
1084 static struct proc_dir_entry
*proc_jbd2_stats
;
1086 static void jbd2_stats_proc_init(journal_t
*journal
)
1088 journal
->j_proc_entry
= proc_mkdir(journal
->j_devname
, proc_jbd2_stats
);
1089 if (journal
->j_proc_entry
) {
1090 proc_create_data("info", S_IRUGO
, journal
->j_proc_entry
,
1091 &jbd2_info_proc_ops
, journal
);
1095 static void jbd2_stats_proc_exit(journal_t
*journal
)
1097 remove_proc_entry("info", journal
->j_proc_entry
);
1098 remove_proc_entry(journal
->j_devname
, proc_jbd2_stats
);
1101 /* Minimum size of descriptor tag */
1102 static int jbd2_min_tag_size(void)
1105 * Tag with 32-bit block numbers does not use last four bytes of the
1108 return sizeof(journal_block_tag_t
) - 4;
1112 * Management for journal control blocks: functions to create and
1113 * destroy journal_t structures, and to initialise and read existing
1114 * journal blocks from disk. */
1116 /* First: create and setup a journal_t object in memory. We initialise
1117 * very few fields yet: that has to wait until we have created the
1118 * journal structures from from scratch, or loaded them from disk. */
1120 static journal_t
*journal_init_common(struct block_device
*bdev
,
1121 struct block_device
*fs_dev
,
1122 unsigned long long start
, int len
, int blocksize
)
1124 static struct lock_class_key jbd2_trans_commit_key
;
1127 struct buffer_head
*bh
;
1130 journal
= kzalloc(sizeof(*journal
), GFP_KERNEL
);
1134 init_waitqueue_head(&journal
->j_wait_transaction_locked
);
1135 init_waitqueue_head(&journal
->j_wait_done_commit
);
1136 init_waitqueue_head(&journal
->j_wait_commit
);
1137 init_waitqueue_head(&journal
->j_wait_updates
);
1138 init_waitqueue_head(&journal
->j_wait_reserved
);
1139 mutex_init(&journal
->j_barrier
);
1140 mutex_init(&journal
->j_checkpoint_mutex
);
1141 spin_lock_init(&journal
->j_revoke_lock
);
1142 spin_lock_init(&journal
->j_list_lock
);
1143 rwlock_init(&journal
->j_state_lock
);
1145 journal
->j_commit_interval
= (HZ
* JBD2_DEFAULT_MAX_COMMIT_AGE
);
1146 journal
->j_min_batch_time
= 0;
1147 journal
->j_max_batch_time
= 15000; /* 15ms */
1148 atomic_set(&journal
->j_reserved_credits
, 0);
1150 /* The journal is marked for error until we succeed with recovery! */
1151 journal
->j_flags
= JBD2_ABORT
;
1153 /* Set up a default-sized revoke table for the new mount. */
1154 err
= jbd2_journal_init_revoke(journal
, JOURNAL_REVOKE_DEFAULT_HASH
);
1158 spin_lock_init(&journal
->j_history_lock
);
1160 lockdep_init_map(&journal
->j_trans_commit_map
, "jbd2_handle",
1161 &jbd2_trans_commit_key
, 0);
1163 /* journal descriptor can store up to n blocks -bzzz */
1164 journal
->j_blocksize
= blocksize
;
1165 journal
->j_dev
= bdev
;
1166 journal
->j_fs_dev
= fs_dev
;
1167 journal
->j_blk_offset
= start
;
1168 journal
->j_maxlen
= len
;
1169 /* We need enough buffers to write out full descriptor block. */
1170 n
= journal
->j_blocksize
/ jbd2_min_tag_size();
1171 journal
->j_wbufsize
= n
;
1172 journal
->j_wbuf
= kmalloc_array(n
, sizeof(struct buffer_head
*),
1174 if (!journal
->j_wbuf
)
1177 bh
= getblk_unmovable(journal
->j_dev
, start
, journal
->j_blocksize
);
1179 pr_err("%s: Cannot get buffer for journal superblock\n",
1183 journal
->j_sb_buffer
= bh
;
1184 journal
->j_superblock
= (journal_superblock_t
*)bh
->b_data
;
1189 kfree(journal
->j_wbuf
);
1190 jbd2_journal_destroy_revoke(journal
);
1195 /* jbd2_journal_init_dev and jbd2_journal_init_inode:
1197 * Create a journal structure assigned some fixed set of disk blocks to
1198 * the journal. We don't actually touch those disk blocks yet, but we
1199 * need to set up all of the mapping information to tell the journaling
1200 * system where the journal blocks are.
1205 * journal_t * jbd2_journal_init_dev() - creates and initialises a journal structure
1206 * @bdev: Block device on which to create the journal
1207 * @fs_dev: Device which hold journalled filesystem for this journal.
1208 * @start: Block nr Start of journal.
1209 * @len: Length of the journal in blocks.
1210 * @blocksize: blocksize of journalling device
1212 * Returns: a newly created journal_t *
1214 * jbd2_journal_init_dev creates a journal which maps a fixed contiguous
1215 * range of blocks on an arbitrary block device.
1218 journal_t
*jbd2_journal_init_dev(struct block_device
*bdev
,
1219 struct block_device
*fs_dev
,
1220 unsigned long long start
, int len
, int blocksize
)
1224 journal
= journal_init_common(bdev
, fs_dev
, start
, len
, blocksize
);
1228 bdevname(journal
->j_dev
, journal
->j_devname
);
1229 strreplace(journal
->j_devname
, '/', '!');
1230 jbd2_stats_proc_init(journal
);
1236 * journal_t * jbd2_journal_init_inode () - creates a journal which maps to a inode.
1237 * @inode: An inode to create the journal in
1239 * jbd2_journal_init_inode creates a journal which maps an on-disk inode as
1240 * the journal. The inode must exist already, must support bmap() and
1241 * must have all data blocks preallocated.
1243 journal_t
*jbd2_journal_init_inode(struct inode
*inode
)
1247 unsigned long long blocknr
;
1249 blocknr
= bmap(inode
, 0);
1251 pr_err("%s: Cannot locate journal superblock\n",
1256 jbd_debug(1, "JBD2: inode %s/%ld, size %lld, bits %d, blksize %ld\n",
1257 inode
->i_sb
->s_id
, inode
->i_ino
, (long long) inode
->i_size
,
1258 inode
->i_sb
->s_blocksize_bits
, inode
->i_sb
->s_blocksize
);
1260 journal
= journal_init_common(inode
->i_sb
->s_bdev
, inode
->i_sb
->s_bdev
,
1261 blocknr
, inode
->i_size
>> inode
->i_sb
->s_blocksize_bits
,
1262 inode
->i_sb
->s_blocksize
);
1266 journal
->j_inode
= inode
;
1267 bdevname(journal
->j_dev
, journal
->j_devname
);
1268 p
= strreplace(journal
->j_devname
, '/', '!');
1269 sprintf(p
, "-%lu", journal
->j_inode
->i_ino
);
1270 jbd2_stats_proc_init(journal
);
1276 * If the journal init or create aborts, we need to mark the journal
1277 * superblock as being NULL to prevent the journal destroy from writing
1278 * back a bogus superblock.
1280 static void journal_fail_superblock (journal_t
*journal
)
1282 struct buffer_head
*bh
= journal
->j_sb_buffer
;
1284 journal
->j_sb_buffer
= NULL
;
1288 * Given a journal_t structure, initialise the various fields for
1289 * startup of a new journaling session. We use this both when creating
1290 * a journal, and after recovering an old journal to reset it for
1294 static int journal_reset(journal_t
*journal
)
1296 journal_superblock_t
*sb
= journal
->j_superblock
;
1297 unsigned long long first
, last
;
1299 first
= be32_to_cpu(sb
->s_first
);
1300 last
= be32_to_cpu(sb
->s_maxlen
);
1301 if (first
+ JBD2_MIN_JOURNAL_BLOCKS
> last
+ 1) {
1302 printk(KERN_ERR
"JBD2: Journal too short (blocks %llu-%llu).\n",
1304 journal_fail_superblock(journal
);
1308 journal
->j_first
= first
;
1309 journal
->j_last
= last
;
1311 journal
->j_head
= first
;
1312 journal
->j_tail
= first
;
1313 journal
->j_free
= last
- first
;
1315 journal
->j_tail_sequence
= journal
->j_transaction_sequence
;
1316 journal
->j_commit_sequence
= journal
->j_transaction_sequence
- 1;
1317 journal
->j_commit_request
= journal
->j_commit_sequence
;
1319 journal
->j_max_transaction_buffers
= journal
->j_maxlen
/ 4;
1322 * As a special case, if the on-disk copy is already marked as needing
1323 * no recovery (s_start == 0), then we can safely defer the superblock
1324 * update until the next commit by setting JBD2_FLUSHED. This avoids
1325 * attempting a write to a potential-readonly device.
1327 if (sb
->s_start
== 0) {
1328 jbd_debug(1, "JBD2: Skipping superblock update on recovered sb "
1329 "(start %ld, seq %u, errno %d)\n",
1330 journal
->j_tail
, journal
->j_tail_sequence
,
1332 journal
->j_flags
|= JBD2_FLUSHED
;
1334 /* Lock here to make assertions happy... */
1335 mutex_lock_io(&journal
->j_checkpoint_mutex
);
1337 * Update log tail information. We use REQ_FUA since new
1338 * transaction will start reusing journal space and so we
1339 * must make sure information about current log tail is on
1342 jbd2_journal_update_sb_log_tail(journal
,
1343 journal
->j_tail_sequence
,
1345 REQ_SYNC
| REQ_FUA
);
1346 mutex_unlock(&journal
->j_checkpoint_mutex
);
1348 return jbd2_journal_start_thread(journal
);
1352 * This function expects that the caller will have locked the journal
1353 * buffer head, and will return with it unlocked
1355 static int jbd2_write_superblock(journal_t
*journal
, int write_flags
)
1357 struct buffer_head
*bh
= journal
->j_sb_buffer
;
1358 journal_superblock_t
*sb
= journal
->j_superblock
;
1361 /* Buffer got discarded which means block device got invalidated */
1362 if (!buffer_mapped(bh
))
1365 trace_jbd2_write_superblock(journal
, write_flags
);
1366 if (!(journal
->j_flags
& JBD2_BARRIER
))
1367 write_flags
&= ~(REQ_FUA
| REQ_PREFLUSH
);
1368 if (buffer_write_io_error(bh
)) {
1370 * Oh, dear. A previous attempt to write the journal
1371 * superblock failed. This could happen because the
1372 * USB device was yanked out. Or it could happen to
1373 * be a transient write error and maybe the block will
1374 * be remapped. Nothing we can do but to retry the
1375 * write and hope for the best.
1377 printk(KERN_ERR
"JBD2: previous I/O error detected "
1378 "for journal superblock update for %s.\n",
1379 journal
->j_devname
);
1380 clear_buffer_write_io_error(bh
);
1381 set_buffer_uptodate(bh
);
1383 if (jbd2_journal_has_csum_v2or3(journal
))
1384 sb
->s_checksum
= jbd2_superblock_csum(journal
, sb
);
1386 bh
->b_end_io
= end_buffer_write_sync
;
1387 ret
= submit_bh(REQ_OP_WRITE
, write_flags
, bh
);
1389 if (buffer_write_io_error(bh
)) {
1390 clear_buffer_write_io_error(bh
);
1391 set_buffer_uptodate(bh
);
1395 printk(KERN_ERR
"JBD2: Error %d detected when updating "
1396 "journal superblock for %s.\n", ret
,
1397 journal
->j_devname
);
1398 jbd2_journal_abort(journal
, ret
);
1405 * jbd2_journal_update_sb_log_tail() - Update log tail in journal sb on disk.
1406 * @journal: The journal to update.
1407 * @tail_tid: TID of the new transaction at the tail of the log
1408 * @tail_block: The first block of the transaction at the tail of the log
1409 * @write_op: With which operation should we write the journal sb
1411 * Update a journal's superblock information about log tail and write it to
1412 * disk, waiting for the IO to complete.
1414 int jbd2_journal_update_sb_log_tail(journal_t
*journal
, tid_t tail_tid
,
1415 unsigned long tail_block
, int write_op
)
1417 journal_superblock_t
*sb
= journal
->j_superblock
;
1420 if (is_journal_aborted(journal
))
1423 BUG_ON(!mutex_is_locked(&journal
->j_checkpoint_mutex
));
1424 jbd_debug(1, "JBD2: updating superblock (start %lu, seq %u)\n",
1425 tail_block
, tail_tid
);
1427 lock_buffer(journal
->j_sb_buffer
);
1428 sb
->s_sequence
= cpu_to_be32(tail_tid
);
1429 sb
->s_start
= cpu_to_be32(tail_block
);
1431 ret
= jbd2_write_superblock(journal
, write_op
);
1435 /* Log is no longer empty */
1436 write_lock(&journal
->j_state_lock
);
1437 WARN_ON(!sb
->s_sequence
);
1438 journal
->j_flags
&= ~JBD2_FLUSHED
;
1439 write_unlock(&journal
->j_state_lock
);
1446 * jbd2_mark_journal_empty() - Mark on disk journal as empty.
1447 * @journal: The journal to update.
1448 * @write_op: With which operation should we write the journal sb
1450 * Update a journal's dynamic superblock fields to show that journal is empty.
1451 * Write updated superblock to disk waiting for IO to complete.
1453 static void jbd2_mark_journal_empty(journal_t
*journal
, int write_op
)
1455 journal_superblock_t
*sb
= journal
->j_superblock
;
1457 BUG_ON(!mutex_is_locked(&journal
->j_checkpoint_mutex
));
1458 lock_buffer(journal
->j_sb_buffer
);
1459 if (sb
->s_start
== 0) { /* Is it already empty? */
1460 unlock_buffer(journal
->j_sb_buffer
);
1464 jbd_debug(1, "JBD2: Marking journal as empty (seq %u)\n",
1465 journal
->j_tail_sequence
);
1467 sb
->s_sequence
= cpu_to_be32(journal
->j_tail_sequence
);
1468 sb
->s_start
= cpu_to_be32(0);
1470 jbd2_write_superblock(journal
, write_op
);
1472 /* Log is no longer empty */
1473 write_lock(&journal
->j_state_lock
);
1474 journal
->j_flags
|= JBD2_FLUSHED
;
1475 write_unlock(&journal
->j_state_lock
);
1480 * jbd2_journal_update_sb_errno() - Update error in the journal.
1481 * @journal: The journal to update.
1483 * Update a journal's errno. Write updated superblock to disk waiting for IO
1486 void jbd2_journal_update_sb_errno(journal_t
*journal
)
1488 journal_superblock_t
*sb
= journal
->j_superblock
;
1491 lock_buffer(journal
->j_sb_buffer
);
1492 errcode
= journal
->j_errno
;
1493 if (errcode
== -ESHUTDOWN
)
1495 jbd_debug(1, "JBD2: updating superblock error (errno %d)\n", errcode
);
1496 sb
->s_errno
= cpu_to_be32(errcode
);
1498 jbd2_write_superblock(journal
, REQ_SYNC
| REQ_FUA
);
1500 EXPORT_SYMBOL(jbd2_journal_update_sb_errno
);
1502 static int journal_revoke_records_per_block(journal_t
*journal
)
1505 int space
= journal
->j_blocksize
- sizeof(jbd2_journal_revoke_header_t
);
1507 if (jbd2_has_feature_64bit(journal
))
1512 if (jbd2_journal_has_csum_v2or3(journal
))
1513 space
-= sizeof(struct jbd2_journal_block_tail
);
1514 return space
/ record_size
;
1518 * Read the superblock for a given journal, performing initial
1519 * validation of the format.
1521 static int journal_get_superblock(journal_t
*journal
)
1523 struct buffer_head
*bh
;
1524 journal_superblock_t
*sb
;
1527 bh
= journal
->j_sb_buffer
;
1529 J_ASSERT(bh
!= NULL
);
1530 if (!buffer_uptodate(bh
)) {
1531 ll_rw_block(REQ_OP_READ
, 0, 1, &bh
);
1533 if (!buffer_uptodate(bh
)) {
1535 "JBD2: IO error reading journal superblock\n");
1540 if (buffer_verified(bh
))
1543 sb
= journal
->j_superblock
;
1547 if (sb
->s_header
.h_magic
!= cpu_to_be32(JBD2_MAGIC_NUMBER
) ||
1548 sb
->s_blocksize
!= cpu_to_be32(journal
->j_blocksize
)) {
1549 printk(KERN_WARNING
"JBD2: no valid journal superblock found\n");
1553 switch(be32_to_cpu(sb
->s_header
.h_blocktype
)) {
1554 case JBD2_SUPERBLOCK_V1
:
1555 journal
->j_format_version
= 1;
1557 case JBD2_SUPERBLOCK_V2
:
1558 journal
->j_format_version
= 2;
1561 printk(KERN_WARNING
"JBD2: unrecognised superblock format ID\n");
1565 if (be32_to_cpu(sb
->s_maxlen
) < journal
->j_maxlen
)
1566 journal
->j_maxlen
= be32_to_cpu(sb
->s_maxlen
);
1567 else if (be32_to_cpu(sb
->s_maxlen
) > journal
->j_maxlen
) {
1568 printk(KERN_WARNING
"JBD2: journal file too short\n");
1572 if (be32_to_cpu(sb
->s_first
) == 0 ||
1573 be32_to_cpu(sb
->s_first
) >= journal
->j_maxlen
) {
1575 "JBD2: Invalid start block of journal: %u\n",
1576 be32_to_cpu(sb
->s_first
));
1580 if (jbd2_has_feature_csum2(journal
) &&
1581 jbd2_has_feature_csum3(journal
)) {
1582 /* Can't have checksum v2 and v3 at the same time! */
1583 printk(KERN_ERR
"JBD2: Can't enable checksumming v2 and v3 "
1584 "at the same time!\n");
1588 if (jbd2_journal_has_csum_v2or3_feature(journal
) &&
1589 jbd2_has_feature_checksum(journal
)) {
1590 /* Can't have checksum v1 and v2 on at the same time! */
1591 printk(KERN_ERR
"JBD2: Can't enable checksumming v1 and v2/3 "
1592 "at the same time!\n");
1596 if (!jbd2_verify_csum_type(journal
, sb
)) {
1597 printk(KERN_ERR
"JBD2: Unknown checksum type\n");
1601 /* Load the checksum driver */
1602 if (jbd2_journal_has_csum_v2or3_feature(journal
)) {
1603 journal
->j_chksum_driver
= crypto_alloc_shash("crc32c", 0, 0);
1604 if (IS_ERR(journal
->j_chksum_driver
)) {
1605 printk(KERN_ERR
"JBD2: Cannot load crc32c driver.\n");
1606 err
= PTR_ERR(journal
->j_chksum_driver
);
1607 journal
->j_chksum_driver
= NULL
;
1612 if (jbd2_journal_has_csum_v2or3(journal
)) {
1613 /* Check superblock checksum */
1614 if (sb
->s_checksum
!= jbd2_superblock_csum(journal
, sb
)) {
1615 printk(KERN_ERR
"JBD2: journal checksum error\n");
1620 /* Precompute checksum seed for all metadata */
1621 journal
->j_csum_seed
= jbd2_chksum(journal
, ~0, sb
->s_uuid
,
1622 sizeof(sb
->s_uuid
));
1625 journal
->j_revoke_records_per_block
=
1626 journal_revoke_records_per_block(journal
);
1627 set_buffer_verified(bh
);
1632 journal_fail_superblock(journal
);
1637 * Load the on-disk journal superblock and read the key fields into the
1641 static int load_superblock(journal_t
*journal
)
1644 journal_superblock_t
*sb
;
1646 err
= journal_get_superblock(journal
);
1650 sb
= journal
->j_superblock
;
1652 journal
->j_tail_sequence
= be32_to_cpu(sb
->s_sequence
);
1653 journal
->j_tail
= be32_to_cpu(sb
->s_start
);
1654 journal
->j_first
= be32_to_cpu(sb
->s_first
);
1655 journal
->j_last
= be32_to_cpu(sb
->s_maxlen
);
1656 journal
->j_errno
= be32_to_cpu(sb
->s_errno
);
1663 * int jbd2_journal_load() - Read journal from disk.
1664 * @journal: Journal to act on.
1666 * Given a journal_t structure which tells us which disk blocks contain
1667 * a journal, read the journal from disk to initialise the in-memory
1670 int jbd2_journal_load(journal_t
*journal
)
1673 journal_superblock_t
*sb
;
1675 err
= load_superblock(journal
);
1679 sb
= journal
->j_superblock
;
1680 /* If this is a V2 superblock, then we have to check the
1681 * features flags on it. */
1683 if (journal
->j_format_version
>= 2) {
1684 if ((sb
->s_feature_ro_compat
&
1685 ~cpu_to_be32(JBD2_KNOWN_ROCOMPAT_FEATURES
)) ||
1686 (sb
->s_feature_incompat
&
1687 ~cpu_to_be32(JBD2_KNOWN_INCOMPAT_FEATURES
))) {
1689 "JBD2: Unrecognised features on journal\n");
1695 * Create a slab for this blocksize
1697 err
= jbd2_journal_create_slab(be32_to_cpu(sb
->s_blocksize
));
1701 /* Let the recovery code check whether it needs to recover any
1702 * data from the journal. */
1703 if (jbd2_journal_recover(journal
))
1704 goto recovery_error
;
1706 if (journal
->j_failed_commit
) {
1707 printk(KERN_ERR
"JBD2: journal transaction %u on %s "
1708 "is corrupt.\n", journal
->j_failed_commit
,
1709 journal
->j_devname
);
1710 return -EFSCORRUPTED
;
1713 * clear JBD2_ABORT flag initialized in journal_init_common
1714 * here to update log tail information with the newest seq.
1716 journal
->j_flags
&= ~JBD2_ABORT
;
1718 /* OK, we've finished with the dynamic journal bits:
1719 * reinitialise the dynamic contents of the superblock in memory
1720 * and reset them on disk. */
1721 if (journal_reset(journal
))
1722 goto recovery_error
;
1724 journal
->j_flags
|= JBD2_LOADED
;
1728 printk(KERN_WARNING
"JBD2: recovery failed\n");
1733 * void jbd2_journal_destroy() - Release a journal_t structure.
1734 * @journal: Journal to act on.
1736 * Release a journal_t structure once it is no longer in use by the
1738 * Return <0 if we couldn't clean up the journal.
1740 int jbd2_journal_destroy(journal_t
*journal
)
1744 /* Wait for the commit thread to wake up and die. */
1745 journal_kill_thread(journal
);
1747 /* Force a final log commit */
1748 if (journal
->j_running_transaction
)
1749 jbd2_journal_commit_transaction(journal
);
1751 /* Force any old transactions to disk */
1753 /* Totally anal locking here... */
1754 spin_lock(&journal
->j_list_lock
);
1755 while (journal
->j_checkpoint_transactions
!= NULL
) {
1756 spin_unlock(&journal
->j_list_lock
);
1757 mutex_lock_io(&journal
->j_checkpoint_mutex
);
1758 err
= jbd2_log_do_checkpoint(journal
);
1759 mutex_unlock(&journal
->j_checkpoint_mutex
);
1761 * If checkpointing failed, just free the buffers to avoid
1765 jbd2_journal_destroy_checkpoint(journal
);
1766 spin_lock(&journal
->j_list_lock
);
1769 spin_lock(&journal
->j_list_lock
);
1772 J_ASSERT(journal
->j_running_transaction
== NULL
);
1773 J_ASSERT(journal
->j_committing_transaction
== NULL
);
1774 J_ASSERT(journal
->j_checkpoint_transactions
== NULL
);
1775 spin_unlock(&journal
->j_list_lock
);
1777 if (journal
->j_sb_buffer
) {
1778 if (!is_journal_aborted(journal
)) {
1779 mutex_lock_io(&journal
->j_checkpoint_mutex
);
1781 write_lock(&journal
->j_state_lock
);
1782 journal
->j_tail_sequence
=
1783 ++journal
->j_transaction_sequence
;
1784 write_unlock(&journal
->j_state_lock
);
1786 jbd2_mark_journal_empty(journal
,
1787 REQ_SYNC
| REQ_PREFLUSH
| REQ_FUA
);
1788 mutex_unlock(&journal
->j_checkpoint_mutex
);
1791 brelse(journal
->j_sb_buffer
);
1794 if (journal
->j_proc_entry
)
1795 jbd2_stats_proc_exit(journal
);
1796 iput(journal
->j_inode
);
1797 if (journal
->j_revoke
)
1798 jbd2_journal_destroy_revoke(journal
);
1799 if (journal
->j_chksum_driver
)
1800 crypto_free_shash(journal
->j_chksum_driver
);
1801 kfree(journal
->j_wbuf
);
1809 *int jbd2_journal_check_used_features () - Check if features specified are used.
1810 * @journal: Journal to check.
1811 * @compat: bitmask of compatible features
1812 * @ro: bitmask of features that force read-only mount
1813 * @incompat: bitmask of incompatible features
1815 * Check whether the journal uses all of a given set of
1816 * features. Return true (non-zero) if it does.
1819 int jbd2_journal_check_used_features (journal_t
*journal
, unsigned long compat
,
1820 unsigned long ro
, unsigned long incompat
)
1822 journal_superblock_t
*sb
;
1824 if (!compat
&& !ro
&& !incompat
)
1826 /* Load journal superblock if it is not loaded yet. */
1827 if (journal
->j_format_version
== 0 &&
1828 journal_get_superblock(journal
) != 0)
1830 if (journal
->j_format_version
== 1)
1833 sb
= journal
->j_superblock
;
1835 if (((be32_to_cpu(sb
->s_feature_compat
) & compat
) == compat
) &&
1836 ((be32_to_cpu(sb
->s_feature_ro_compat
) & ro
) == ro
) &&
1837 ((be32_to_cpu(sb
->s_feature_incompat
) & incompat
) == incompat
))
1844 * int jbd2_journal_check_available_features() - Check feature set in journalling layer
1845 * @journal: Journal to check.
1846 * @compat: bitmask of compatible features
1847 * @ro: bitmask of features that force read-only mount
1848 * @incompat: bitmask of incompatible features
1850 * Check whether the journaling code supports the use of
1851 * all of a given set of features on this journal. Return true
1852 * (non-zero) if it can. */
1854 int jbd2_journal_check_available_features (journal_t
*journal
, unsigned long compat
,
1855 unsigned long ro
, unsigned long incompat
)
1857 if (!compat
&& !ro
&& !incompat
)
1860 /* We can support any known requested features iff the
1861 * superblock is in version 2. Otherwise we fail to support any
1862 * extended sb features. */
1864 if (journal
->j_format_version
!= 2)
1867 if ((compat
& JBD2_KNOWN_COMPAT_FEATURES
) == compat
&&
1868 (ro
& JBD2_KNOWN_ROCOMPAT_FEATURES
) == ro
&&
1869 (incompat
& JBD2_KNOWN_INCOMPAT_FEATURES
) == incompat
)
1876 * int jbd2_journal_set_features () - Mark a given journal feature in the superblock
1877 * @journal: Journal to act on.
1878 * @compat: bitmask of compatible features
1879 * @ro: bitmask of features that force read-only mount
1880 * @incompat: bitmask of incompatible features
1882 * Mark a given journal feature as present on the
1883 * superblock. Returns true if the requested features could be set.
1887 int jbd2_journal_set_features (journal_t
*journal
, unsigned long compat
,
1888 unsigned long ro
, unsigned long incompat
)
1890 #define INCOMPAT_FEATURE_ON(f) \
1891 ((incompat & (f)) && !(sb->s_feature_incompat & cpu_to_be32(f)))
1892 #define COMPAT_FEATURE_ON(f) \
1893 ((compat & (f)) && !(sb->s_feature_compat & cpu_to_be32(f)))
1894 journal_superblock_t
*sb
;
1896 if (jbd2_journal_check_used_features(journal
, compat
, ro
, incompat
))
1899 if (!jbd2_journal_check_available_features(journal
, compat
, ro
, incompat
))
1902 /* If enabling v2 checksums, turn on v3 instead */
1903 if (incompat
& JBD2_FEATURE_INCOMPAT_CSUM_V2
) {
1904 incompat
&= ~JBD2_FEATURE_INCOMPAT_CSUM_V2
;
1905 incompat
|= JBD2_FEATURE_INCOMPAT_CSUM_V3
;
1908 /* Asking for checksumming v3 and v1? Only give them v3. */
1909 if (incompat
& JBD2_FEATURE_INCOMPAT_CSUM_V3
&&
1910 compat
& JBD2_FEATURE_COMPAT_CHECKSUM
)
1911 compat
&= ~JBD2_FEATURE_COMPAT_CHECKSUM
;
1913 jbd_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n",
1914 compat
, ro
, incompat
);
1916 sb
= journal
->j_superblock
;
1918 /* Load the checksum driver if necessary */
1919 if ((journal
->j_chksum_driver
== NULL
) &&
1920 INCOMPAT_FEATURE_ON(JBD2_FEATURE_INCOMPAT_CSUM_V3
)) {
1921 journal
->j_chksum_driver
= crypto_alloc_shash("crc32c", 0, 0);
1922 if (IS_ERR(journal
->j_chksum_driver
)) {
1923 printk(KERN_ERR
"JBD2: Cannot load crc32c driver.\n");
1924 journal
->j_chksum_driver
= NULL
;
1927 /* Precompute checksum seed for all metadata */
1928 journal
->j_csum_seed
= jbd2_chksum(journal
, ~0, sb
->s_uuid
,
1929 sizeof(sb
->s_uuid
));
1932 lock_buffer(journal
->j_sb_buffer
);
1934 /* If enabling v3 checksums, update superblock */
1935 if (INCOMPAT_FEATURE_ON(JBD2_FEATURE_INCOMPAT_CSUM_V3
)) {
1936 sb
->s_checksum_type
= JBD2_CRC32C_CHKSUM
;
1937 sb
->s_feature_compat
&=
1938 ~cpu_to_be32(JBD2_FEATURE_COMPAT_CHECKSUM
);
1941 /* If enabling v1 checksums, downgrade superblock */
1942 if (COMPAT_FEATURE_ON(JBD2_FEATURE_COMPAT_CHECKSUM
))
1943 sb
->s_feature_incompat
&=
1944 ~cpu_to_be32(JBD2_FEATURE_INCOMPAT_CSUM_V2
|
1945 JBD2_FEATURE_INCOMPAT_CSUM_V3
);
1947 sb
->s_feature_compat
|= cpu_to_be32(compat
);
1948 sb
->s_feature_ro_compat
|= cpu_to_be32(ro
);
1949 sb
->s_feature_incompat
|= cpu_to_be32(incompat
);
1950 unlock_buffer(journal
->j_sb_buffer
);
1951 journal
->j_revoke_records_per_block
=
1952 journal_revoke_records_per_block(journal
);
1955 #undef COMPAT_FEATURE_ON
1956 #undef INCOMPAT_FEATURE_ON
1960 * jbd2_journal_clear_features () - Clear a given journal feature in the
1962 * @journal: Journal to act on.
1963 * @compat: bitmask of compatible features
1964 * @ro: bitmask of features that force read-only mount
1965 * @incompat: bitmask of incompatible features
1967 * Clear a given journal feature as present on the
1970 void jbd2_journal_clear_features(journal_t
*journal
, unsigned long compat
,
1971 unsigned long ro
, unsigned long incompat
)
1973 journal_superblock_t
*sb
;
1975 jbd_debug(1, "Clear features 0x%lx/0x%lx/0x%lx\n",
1976 compat
, ro
, incompat
);
1978 sb
= journal
->j_superblock
;
1980 sb
->s_feature_compat
&= ~cpu_to_be32(compat
);
1981 sb
->s_feature_ro_compat
&= ~cpu_to_be32(ro
);
1982 sb
->s_feature_incompat
&= ~cpu_to_be32(incompat
);
1983 journal
->j_revoke_records_per_block
=
1984 journal_revoke_records_per_block(journal
);
1986 EXPORT_SYMBOL(jbd2_journal_clear_features
);
1989 * int jbd2_journal_flush () - Flush journal
1990 * @journal: Journal to act on.
1992 * Flush all data for a given journal to disk and empty the journal.
1993 * Filesystems can use this when remounting readonly to ensure that
1994 * recovery does not need to happen on remount.
1997 int jbd2_journal_flush(journal_t
*journal
)
2000 transaction_t
*transaction
= NULL
;
2002 write_lock(&journal
->j_state_lock
);
2004 /* Force everything buffered to the log... */
2005 if (journal
->j_running_transaction
) {
2006 transaction
= journal
->j_running_transaction
;
2007 __jbd2_log_start_commit(journal
, transaction
->t_tid
);
2008 } else if (journal
->j_committing_transaction
)
2009 transaction
= journal
->j_committing_transaction
;
2011 /* Wait for the log commit to complete... */
2013 tid_t tid
= transaction
->t_tid
;
2015 write_unlock(&journal
->j_state_lock
);
2016 jbd2_log_wait_commit(journal
, tid
);
2018 write_unlock(&journal
->j_state_lock
);
2021 /* ...and flush everything in the log out to disk. */
2022 spin_lock(&journal
->j_list_lock
);
2023 while (!err
&& journal
->j_checkpoint_transactions
!= NULL
) {
2024 spin_unlock(&journal
->j_list_lock
);
2025 mutex_lock_io(&journal
->j_checkpoint_mutex
);
2026 err
= jbd2_log_do_checkpoint(journal
);
2027 mutex_unlock(&journal
->j_checkpoint_mutex
);
2028 spin_lock(&journal
->j_list_lock
);
2030 spin_unlock(&journal
->j_list_lock
);
2032 if (is_journal_aborted(journal
))
2035 mutex_lock_io(&journal
->j_checkpoint_mutex
);
2037 err
= jbd2_cleanup_journal_tail(journal
);
2039 mutex_unlock(&journal
->j_checkpoint_mutex
);
2045 /* Finally, mark the journal as really needing no recovery.
2046 * This sets s_start==0 in the underlying superblock, which is
2047 * the magic code for a fully-recovered superblock. Any future
2048 * commits of data to the journal will restore the current
2050 jbd2_mark_journal_empty(journal
, REQ_SYNC
| REQ_FUA
);
2051 mutex_unlock(&journal
->j_checkpoint_mutex
);
2052 write_lock(&journal
->j_state_lock
);
2053 J_ASSERT(!journal
->j_running_transaction
);
2054 J_ASSERT(!journal
->j_committing_transaction
);
2055 J_ASSERT(!journal
->j_checkpoint_transactions
);
2056 J_ASSERT(journal
->j_head
== journal
->j_tail
);
2057 J_ASSERT(journal
->j_tail_sequence
== journal
->j_transaction_sequence
);
2058 write_unlock(&journal
->j_state_lock
);
2064 * int jbd2_journal_wipe() - Wipe journal contents
2065 * @journal: Journal to act on.
2066 * @write: flag (see below)
2068 * Wipe out all of the contents of a journal, safely. This will produce
2069 * a warning if the journal contains any valid recovery information.
2070 * Must be called between journal_init_*() and jbd2_journal_load().
2072 * If 'write' is non-zero, then we wipe out the journal on disk; otherwise
2073 * we merely suppress recovery.
2076 int jbd2_journal_wipe(journal_t
*journal
, int write
)
2080 J_ASSERT (!(journal
->j_flags
& JBD2_LOADED
));
2082 err
= load_superblock(journal
);
2086 if (!journal
->j_tail
)
2089 printk(KERN_WARNING
"JBD2: %s recovery information on journal\n",
2090 write
? "Clearing" : "Ignoring");
2092 err
= jbd2_journal_skip_recovery(journal
);
2094 /* Lock to make assertions happy... */
2095 mutex_lock_io(&journal
->j_checkpoint_mutex
);
2096 jbd2_mark_journal_empty(journal
, REQ_SYNC
| REQ_FUA
);
2097 mutex_unlock(&journal
->j_checkpoint_mutex
);
2105 * void jbd2_journal_abort () - Shutdown the journal immediately.
2106 * @journal: the journal to shutdown.
2107 * @errno: an error number to record in the journal indicating
2108 * the reason for the shutdown.
2110 * Perform a complete, immediate shutdown of the ENTIRE
2111 * journal (not of a single transaction). This operation cannot be
2112 * undone without closing and reopening the journal.
2114 * The jbd2_journal_abort function is intended to support higher level error
2115 * recovery mechanisms such as the ext2/ext3 remount-readonly error
2118 * Journal abort has very specific semantics. Any existing dirty,
2119 * unjournaled buffers in the main filesystem will still be written to
2120 * disk by bdflush, but the journaling mechanism will be suspended
2121 * immediately and no further transaction commits will be honoured.
2123 * Any dirty, journaled buffers will be written back to disk without
2124 * hitting the journal. Atomicity cannot be guaranteed on an aborted
2125 * filesystem, but we _do_ attempt to leave as much data as possible
2126 * behind for fsck to use for cleanup.
2128 * Any attempt to get a new transaction handle on a journal which is in
2129 * ABORT state will just result in an -EROFS error return. A
2130 * jbd2_journal_stop on an existing handle will return -EIO if we have
2131 * entered abort state during the update.
2133 * Recursive transactions are not disturbed by journal abort until the
2134 * final jbd2_journal_stop, which will receive the -EIO error.
2136 * Finally, the jbd2_journal_abort call allows the caller to supply an errno
2137 * which will be recorded (if possible) in the journal superblock. This
2138 * allows a client to record failure conditions in the middle of a
2139 * transaction without having to complete the transaction to record the
2140 * failure to disk. ext3_error, for example, now uses this
2145 void jbd2_journal_abort(journal_t
*journal
, int errno
)
2147 transaction_t
*transaction
;
2150 * ESHUTDOWN always takes precedence because a file system check
2151 * caused by any other journal abort error is not required after
2152 * a shutdown triggered.
2154 write_lock(&journal
->j_state_lock
);
2155 if (journal
->j_flags
& JBD2_ABORT
) {
2156 int old_errno
= journal
->j_errno
;
2158 write_unlock(&journal
->j_state_lock
);
2159 if (old_errno
!= -ESHUTDOWN
&& errno
== -ESHUTDOWN
) {
2160 journal
->j_errno
= errno
;
2161 jbd2_journal_update_sb_errno(journal
);
2167 * Mark the abort as occurred and start current running transaction
2168 * to release all journaled buffer.
2170 pr_err("Aborting journal on device %s.\n", journal
->j_devname
);
2172 journal
->j_flags
|= JBD2_ABORT
;
2173 journal
->j_errno
= errno
;
2174 transaction
= journal
->j_running_transaction
;
2176 __jbd2_log_start_commit(journal
, transaction
->t_tid
);
2177 write_unlock(&journal
->j_state_lock
);
2180 * Record errno to the journal super block, so that fsck and jbd2
2181 * layer could realise that a filesystem check is needed.
2183 jbd2_journal_update_sb_errno(journal
);
2185 write_lock(&journal
->j_state_lock
);
2186 journal
->j_flags
|= JBD2_REC_ERR
;
2187 write_unlock(&journal
->j_state_lock
);
2191 * int jbd2_journal_errno () - returns the journal's error state.
2192 * @journal: journal to examine.
2194 * This is the errno number set with jbd2_journal_abort(), the last
2195 * time the journal was mounted - if the journal was stopped
2196 * without calling abort this will be 0.
2198 * If the journal has been aborted on this mount time -EROFS will
2201 int jbd2_journal_errno(journal_t
*journal
)
2205 read_lock(&journal
->j_state_lock
);
2206 if (journal
->j_flags
& JBD2_ABORT
)
2209 err
= journal
->j_errno
;
2210 read_unlock(&journal
->j_state_lock
);
2215 * int jbd2_journal_clear_err () - clears the journal's error state
2216 * @journal: journal to act on.
2218 * An error must be cleared or acked to take a FS out of readonly
2221 int jbd2_journal_clear_err(journal_t
*journal
)
2225 write_lock(&journal
->j_state_lock
);
2226 if (journal
->j_flags
& JBD2_ABORT
)
2229 journal
->j_errno
= 0;
2230 write_unlock(&journal
->j_state_lock
);
2235 * void jbd2_journal_ack_err() - Ack journal err.
2236 * @journal: journal to act on.
2238 * An error must be cleared or acked to take a FS out of readonly
2241 void jbd2_journal_ack_err(journal_t
*journal
)
2243 write_lock(&journal
->j_state_lock
);
2244 if (journal
->j_errno
)
2245 journal
->j_flags
|= JBD2_ACK_ERR
;
2246 write_unlock(&journal
->j_state_lock
);
2249 int jbd2_journal_blocks_per_page(struct inode
*inode
)
2251 return 1 << (PAGE_SHIFT
- inode
->i_sb
->s_blocksize_bits
);
2255 * helper functions to deal with 32 or 64bit block numbers.
2257 size_t journal_tag_bytes(journal_t
*journal
)
2261 if (jbd2_has_feature_csum3(journal
))
2262 return sizeof(journal_block_tag3_t
);
2264 sz
= sizeof(journal_block_tag_t
);
2266 if (jbd2_has_feature_csum2(journal
))
2267 sz
+= sizeof(__u16
);
2269 if (jbd2_has_feature_64bit(journal
))
2272 return sz
- sizeof(__u32
);
2276 * JBD memory management
2278 * These functions are used to allocate block-sized chunks of memory
2279 * used for making copies of buffer_head data. Very often it will be
2280 * page-sized chunks of data, but sometimes it will be in
2281 * sub-page-size chunks. (For example, 16k pages on Power systems
2282 * with a 4k block file system.) For blocks smaller than a page, we
2283 * use a SLAB allocator. There are slab caches for each block size,
2284 * which are allocated at mount time, if necessary, and we only free
2285 * (all of) the slab caches when/if the jbd2 module is unloaded. For
2286 * this reason we don't need to a mutex to protect access to
2287 * jbd2_slab[] allocating or releasing memory; only in
2288 * jbd2_journal_create_slab().
2290 #define JBD2_MAX_SLABS 8
2291 static struct kmem_cache
*jbd2_slab
[JBD2_MAX_SLABS
];
2293 static const char *jbd2_slab_names
[JBD2_MAX_SLABS
] = {
2294 "jbd2_1k", "jbd2_2k", "jbd2_4k", "jbd2_8k",
2295 "jbd2_16k", "jbd2_32k", "jbd2_64k", "jbd2_128k"
2299 static void jbd2_journal_destroy_slabs(void)
2303 for (i
= 0; i
< JBD2_MAX_SLABS
; i
++) {
2304 kmem_cache_destroy(jbd2_slab
[i
]);
2305 jbd2_slab
[i
] = NULL
;
2309 static int jbd2_journal_create_slab(size_t size
)
2311 static DEFINE_MUTEX(jbd2_slab_create_mutex
);
2312 int i
= order_base_2(size
) - 10;
2315 if (size
== PAGE_SIZE
)
2318 if (i
>= JBD2_MAX_SLABS
)
2321 if (unlikely(i
< 0))
2323 mutex_lock(&jbd2_slab_create_mutex
);
2325 mutex_unlock(&jbd2_slab_create_mutex
);
2326 return 0; /* Already created */
2329 slab_size
= 1 << (i
+10);
2330 jbd2_slab
[i
] = kmem_cache_create(jbd2_slab_names
[i
], slab_size
,
2331 slab_size
, 0, NULL
);
2332 mutex_unlock(&jbd2_slab_create_mutex
);
2333 if (!jbd2_slab
[i
]) {
2334 printk(KERN_EMERG
"JBD2: no memory for jbd2_slab cache\n");
2340 static struct kmem_cache
*get_slab(size_t size
)
2342 int i
= order_base_2(size
) - 10;
2344 BUG_ON(i
>= JBD2_MAX_SLABS
);
2345 if (unlikely(i
< 0))
2347 BUG_ON(jbd2_slab
[i
] == NULL
);
2348 return jbd2_slab
[i
];
2351 void *jbd2_alloc(size_t size
, gfp_t flags
)
2355 BUG_ON(size
& (size
-1)); /* Must be a power of 2 */
2357 if (size
< PAGE_SIZE
)
2358 ptr
= kmem_cache_alloc(get_slab(size
), flags
);
2360 ptr
= (void *)__get_free_pages(flags
, get_order(size
));
2362 /* Check alignment; SLUB has gotten this wrong in the past,
2363 * and this can lead to user data corruption! */
2364 BUG_ON(((unsigned long) ptr
) & (size
-1));
2369 void jbd2_free(void *ptr
, size_t size
)
2371 if (size
< PAGE_SIZE
)
2372 kmem_cache_free(get_slab(size
), ptr
);
2374 free_pages((unsigned long)ptr
, get_order(size
));
2378 * Journal_head storage management
2380 static struct kmem_cache
*jbd2_journal_head_cache
;
2381 #ifdef CONFIG_JBD2_DEBUG
2382 static atomic_t nr_journal_heads
= ATOMIC_INIT(0);
2385 static int __init
jbd2_journal_init_journal_head_cache(void)
2387 J_ASSERT(!jbd2_journal_head_cache
);
2388 jbd2_journal_head_cache
= kmem_cache_create("jbd2_journal_head",
2389 sizeof(struct journal_head
),
2391 SLAB_TEMPORARY
| SLAB_TYPESAFE_BY_RCU
,
2393 if (!jbd2_journal_head_cache
) {
2394 printk(KERN_EMERG
"JBD2: no memory for journal_head cache\n");
2400 static void jbd2_journal_destroy_journal_head_cache(void)
2402 kmem_cache_destroy(jbd2_journal_head_cache
);
2403 jbd2_journal_head_cache
= NULL
;
2407 * journal_head splicing and dicing
2409 static struct journal_head
*journal_alloc_journal_head(void)
2411 struct journal_head
*ret
;
2413 #ifdef CONFIG_JBD2_DEBUG
2414 atomic_inc(&nr_journal_heads
);
2416 ret
= kmem_cache_zalloc(jbd2_journal_head_cache
, GFP_NOFS
);
2418 jbd_debug(1, "out of memory for journal_head\n");
2419 pr_notice_ratelimited("ENOMEM in %s, retrying.\n", __func__
);
2420 ret
= kmem_cache_zalloc(jbd2_journal_head_cache
,
2421 GFP_NOFS
| __GFP_NOFAIL
);
2424 spin_lock_init(&ret
->b_state_lock
);
2428 static void journal_free_journal_head(struct journal_head
*jh
)
2430 #ifdef CONFIG_JBD2_DEBUG
2431 atomic_dec(&nr_journal_heads
);
2432 memset(jh
, JBD2_POISON_FREE
, sizeof(*jh
));
2434 kmem_cache_free(jbd2_journal_head_cache
, jh
);
2438 * A journal_head is attached to a buffer_head whenever JBD has an
2439 * interest in the buffer.
2441 * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit
2442 * is set. This bit is tested in core kernel code where we need to take
2443 * JBD-specific actions. Testing the zeroness of ->b_private is not reliable
2446 * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one.
2448 * When a buffer has its BH_JBD bit set it is immune from being released by
2449 * core kernel code, mainly via ->b_count.
2451 * A journal_head is detached from its buffer_head when the journal_head's
2452 * b_jcount reaches zero. Running transaction (b_transaction) and checkpoint
2453 * transaction (b_cp_transaction) hold their references to b_jcount.
2455 * Various places in the kernel want to attach a journal_head to a buffer_head
2456 * _before_ attaching the journal_head to a transaction. To protect the
2457 * journal_head in this situation, jbd2_journal_add_journal_head elevates the
2458 * journal_head's b_jcount refcount by one. The caller must call
2459 * jbd2_journal_put_journal_head() to undo this.
2461 * So the typical usage would be:
2463 * (Attach a journal_head if needed. Increments b_jcount)
2464 * struct journal_head *jh = jbd2_journal_add_journal_head(bh);
2466 * (Get another reference for transaction)
2467 * jbd2_journal_grab_journal_head(bh);
2468 * jh->b_transaction = xxx;
2469 * (Put original reference)
2470 * jbd2_journal_put_journal_head(jh);
2474 * Give a buffer_head a journal_head.
2478 struct journal_head
*jbd2_journal_add_journal_head(struct buffer_head
*bh
)
2480 struct journal_head
*jh
;
2481 struct journal_head
*new_jh
= NULL
;
2484 if (!buffer_jbd(bh
))
2485 new_jh
= journal_alloc_journal_head();
2487 jbd_lock_bh_journal_head(bh
);
2488 if (buffer_jbd(bh
)) {
2492 (atomic_read(&bh
->b_count
) > 0) ||
2493 (bh
->b_page
&& bh
->b_page
->mapping
));
2496 jbd_unlock_bh_journal_head(bh
);
2501 new_jh
= NULL
; /* We consumed it */
2506 BUFFER_TRACE(bh
, "added journal_head");
2509 jbd_unlock_bh_journal_head(bh
);
2511 journal_free_journal_head(new_jh
);
2512 return bh
->b_private
;
2516 * Grab a ref against this buffer_head's journal_head. If it ended up not
2517 * having a journal_head, return NULL
2519 struct journal_head
*jbd2_journal_grab_journal_head(struct buffer_head
*bh
)
2521 struct journal_head
*jh
= NULL
;
2523 jbd_lock_bh_journal_head(bh
);
2524 if (buffer_jbd(bh
)) {
2528 jbd_unlock_bh_journal_head(bh
);
2532 static void __journal_remove_journal_head(struct buffer_head
*bh
)
2534 struct journal_head
*jh
= bh2jh(bh
);
2536 J_ASSERT_JH(jh
, jh
->b_transaction
== NULL
);
2537 J_ASSERT_JH(jh
, jh
->b_next_transaction
== NULL
);
2538 J_ASSERT_JH(jh
, jh
->b_cp_transaction
== NULL
);
2539 J_ASSERT_JH(jh
, jh
->b_jlist
== BJ_None
);
2540 J_ASSERT_BH(bh
, buffer_jbd(bh
));
2541 J_ASSERT_BH(bh
, jh2bh(jh
) == bh
);
2542 BUFFER_TRACE(bh
, "remove journal_head");
2544 /* Unlink before dropping the lock */
2545 bh
->b_private
= NULL
;
2546 jh
->b_bh
= NULL
; /* debug, really */
2547 clear_buffer_jbd(bh
);
2550 static void journal_release_journal_head(struct journal_head
*jh
, size_t b_size
)
2552 if (jh
->b_frozen_data
) {
2553 printk(KERN_WARNING
"%s: freeing b_frozen_data\n", __func__
);
2554 jbd2_free(jh
->b_frozen_data
, b_size
);
2556 if (jh
->b_committed_data
) {
2557 printk(KERN_WARNING
"%s: freeing b_committed_data\n", __func__
);
2558 jbd2_free(jh
->b_committed_data
, b_size
);
2560 journal_free_journal_head(jh
);
2564 * Drop a reference on the passed journal_head. If it fell to zero then
2565 * release the journal_head from the buffer_head.
2567 void jbd2_journal_put_journal_head(struct journal_head
*jh
)
2569 struct buffer_head
*bh
= jh2bh(jh
);
2571 jbd_lock_bh_journal_head(bh
);
2572 J_ASSERT_JH(jh
, jh
->b_jcount
> 0);
2574 if (!jh
->b_jcount
) {
2575 __journal_remove_journal_head(bh
);
2576 jbd_unlock_bh_journal_head(bh
);
2577 journal_release_journal_head(jh
, bh
->b_size
);
2580 jbd_unlock_bh_journal_head(bh
);
2585 * Initialize jbd inode head
2587 void jbd2_journal_init_jbd_inode(struct jbd2_inode
*jinode
, struct inode
*inode
)
2589 jinode
->i_transaction
= NULL
;
2590 jinode
->i_next_transaction
= NULL
;
2591 jinode
->i_vfs_inode
= inode
;
2592 jinode
->i_flags
= 0;
2593 jinode
->i_dirty_start
= 0;
2594 jinode
->i_dirty_end
= 0;
2595 INIT_LIST_HEAD(&jinode
->i_list
);
2599 * Function to be called before we start removing inode from memory (i.e.,
2600 * clear_inode() is a fine place to be called from). It removes inode from
2601 * transaction's lists.
2603 void jbd2_journal_release_jbd_inode(journal_t
*journal
,
2604 struct jbd2_inode
*jinode
)
2609 spin_lock(&journal
->j_list_lock
);
2610 /* Is commit writing out inode - we have to wait */
2611 if (jinode
->i_flags
& JI_COMMIT_RUNNING
) {
2612 wait_queue_head_t
*wq
;
2613 DEFINE_WAIT_BIT(wait
, &jinode
->i_flags
, __JI_COMMIT_RUNNING
);
2614 wq
= bit_waitqueue(&jinode
->i_flags
, __JI_COMMIT_RUNNING
);
2615 prepare_to_wait(wq
, &wait
.wq_entry
, TASK_UNINTERRUPTIBLE
);
2616 spin_unlock(&journal
->j_list_lock
);
2618 finish_wait(wq
, &wait
.wq_entry
);
2622 if (jinode
->i_transaction
) {
2623 list_del(&jinode
->i_list
);
2624 jinode
->i_transaction
= NULL
;
2626 spin_unlock(&journal
->j_list_lock
);
2630 #ifdef CONFIG_PROC_FS
2632 #define JBD2_STATS_PROC_NAME "fs/jbd2"
2634 static void __init
jbd2_create_jbd_stats_proc_entry(void)
2636 proc_jbd2_stats
= proc_mkdir(JBD2_STATS_PROC_NAME
, NULL
);
2639 static void __exit
jbd2_remove_jbd_stats_proc_entry(void)
2641 if (proc_jbd2_stats
)
2642 remove_proc_entry(JBD2_STATS_PROC_NAME
, NULL
);
2647 #define jbd2_create_jbd_stats_proc_entry() do {} while (0)
2648 #define jbd2_remove_jbd_stats_proc_entry() do {} while (0)
2652 struct kmem_cache
*jbd2_handle_cache
, *jbd2_inode_cache
;
2654 static int __init
jbd2_journal_init_inode_cache(void)
2656 J_ASSERT(!jbd2_inode_cache
);
2657 jbd2_inode_cache
= KMEM_CACHE(jbd2_inode
, 0);
2658 if (!jbd2_inode_cache
) {
2659 pr_emerg("JBD2: failed to create inode cache\n");
2665 static int __init
jbd2_journal_init_handle_cache(void)
2667 J_ASSERT(!jbd2_handle_cache
);
2668 jbd2_handle_cache
= KMEM_CACHE(jbd2_journal_handle
, SLAB_TEMPORARY
);
2669 if (!jbd2_handle_cache
) {
2670 printk(KERN_EMERG
"JBD2: failed to create handle cache\n");
2676 static void jbd2_journal_destroy_inode_cache(void)
2678 kmem_cache_destroy(jbd2_inode_cache
);
2679 jbd2_inode_cache
= NULL
;
2682 static void jbd2_journal_destroy_handle_cache(void)
2684 kmem_cache_destroy(jbd2_handle_cache
);
2685 jbd2_handle_cache
= NULL
;
2689 * Module startup and shutdown
2692 static int __init
journal_init_caches(void)
2696 ret
= jbd2_journal_init_revoke_record_cache();
2698 ret
= jbd2_journal_init_revoke_table_cache();
2700 ret
= jbd2_journal_init_journal_head_cache();
2702 ret
= jbd2_journal_init_handle_cache();
2704 ret
= jbd2_journal_init_inode_cache();
2706 ret
= jbd2_journal_init_transaction_cache();
2710 static void jbd2_journal_destroy_caches(void)
2712 jbd2_journal_destroy_revoke_record_cache();
2713 jbd2_journal_destroy_revoke_table_cache();
2714 jbd2_journal_destroy_journal_head_cache();
2715 jbd2_journal_destroy_handle_cache();
2716 jbd2_journal_destroy_inode_cache();
2717 jbd2_journal_destroy_transaction_cache();
2718 jbd2_journal_destroy_slabs();
2721 static int __init
journal_init(void)
2725 BUILD_BUG_ON(sizeof(struct journal_superblock_s
) != 1024);
2727 ret
= journal_init_caches();
2729 jbd2_create_jbd_stats_proc_entry();
2731 jbd2_journal_destroy_caches();
2736 static void __exit
journal_exit(void)
2738 #ifdef CONFIG_JBD2_DEBUG
2739 int n
= atomic_read(&nr_journal_heads
);
2741 printk(KERN_ERR
"JBD2: leaked %d journal_heads!\n", n
);
2743 jbd2_remove_jbd_stats_proc_entry();
2744 jbd2_journal_destroy_caches();
2747 MODULE_LICENSE("GPL");
2748 module_init(journal_init
);
2749 module_exit(journal_exit
);