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1/*
2 * linux/fs/jbd/journal.c
3 *
4 * Written by Stephen C. Tweedie <sct@redhat.com>, 1998
5 *
6 * Copyright 1998 Red Hat corp --- All Rights Reserved
7 *
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.
11 *
12 * Generic filesystem journal-writing code; part of the ext2fs
13 * journaling system.
14 *
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.
18 *
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).
23 */
24
25#include <linux/module.h>
26#include <linux/time.h>
27#include <linux/fs.h>
28#include <linux/jbd.h>
29#include <linux/errno.h>
30#include <linux/slab.h>
31#include <linux/init.h>
32#include <linux/mm.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/ratelimit.h>
40
41#define CREATE_TRACE_POINTS
42#include <trace/events/jbd.h>
43
44#include <asm/uaccess.h>
45#include <asm/page.h>
46
47EXPORT_SYMBOL(journal_start);
48EXPORT_SYMBOL(journal_restart);
49EXPORT_SYMBOL(journal_extend);
50EXPORT_SYMBOL(journal_stop);
51EXPORT_SYMBOL(journal_lock_updates);
52EXPORT_SYMBOL(journal_unlock_updates);
53EXPORT_SYMBOL(journal_get_write_access);
54EXPORT_SYMBOL(journal_get_create_access);
55EXPORT_SYMBOL(journal_get_undo_access);
56EXPORT_SYMBOL(journal_dirty_data);
57EXPORT_SYMBOL(journal_dirty_metadata);
58EXPORT_SYMBOL(journal_release_buffer);
59EXPORT_SYMBOL(journal_forget);
60#if 0
61EXPORT_SYMBOL(journal_sync_buffer);
62#endif
63EXPORT_SYMBOL(journal_flush);
64EXPORT_SYMBOL(journal_revoke);
65
66EXPORT_SYMBOL(journal_init_dev);
67EXPORT_SYMBOL(journal_init_inode);
68EXPORT_SYMBOL(journal_update_format);
69EXPORT_SYMBOL(journal_check_used_features);
70EXPORT_SYMBOL(journal_check_available_features);
71EXPORT_SYMBOL(journal_set_features);
72EXPORT_SYMBOL(journal_create);
73EXPORT_SYMBOL(journal_load);
74EXPORT_SYMBOL(journal_destroy);
75EXPORT_SYMBOL(journal_abort);
76EXPORT_SYMBOL(journal_errno);
77EXPORT_SYMBOL(journal_ack_err);
78EXPORT_SYMBOL(journal_clear_err);
79EXPORT_SYMBOL(log_wait_commit);
80EXPORT_SYMBOL(log_start_commit);
81EXPORT_SYMBOL(journal_start_commit);
82EXPORT_SYMBOL(journal_force_commit_nested);
83EXPORT_SYMBOL(journal_wipe);
84EXPORT_SYMBOL(journal_blocks_per_page);
85EXPORT_SYMBOL(journal_invalidatepage);
86EXPORT_SYMBOL(journal_try_to_free_buffers);
87EXPORT_SYMBOL(journal_force_commit);
88
89static int journal_convert_superblock_v1(journal_t *, journal_superblock_t *);
90static void __journal_abort_soft (journal_t *journal, int errno);
91static const char *journal_dev_name(journal_t *journal, char *buffer);
92
93/*
94 * Helper function used to manage commit timeouts
95 */
96
97static void commit_timeout(unsigned long __data)
98{
99 struct task_struct * p = (struct task_struct *) __data;
100
101 wake_up_process(p);
102}
103
104/*
105 * kjournald: The main thread function used to manage a logging device
106 * journal.
107 *
108 * This kernel thread is responsible for two things:
109 *
110 * 1) COMMIT: Every so often we need to commit the current state of the
111 * filesystem to disk. The journal thread is responsible for writing
112 * all of the metadata buffers to disk.
113 *
114 * 2) CHECKPOINT: We cannot reuse a used section of the log file until all
115 * of the data in that part of the log has been rewritten elsewhere on
116 * the disk. Flushing these old buffers to reclaim space in the log is
117 * known as checkpointing, and this thread is responsible for that job.
118 */
119
120static int kjournald(void *arg)
121{
122 journal_t *journal = arg;
123 transaction_t *transaction;
124
125 /*
126 * Set up an interval timer which can be used to trigger a commit wakeup
127 * after the commit interval expires
128 */
129 setup_timer(&journal->j_commit_timer, commit_timeout,
130 (unsigned long)current);
131
132 set_freezable();
133
134 /* Record that the journal thread is running */
135 journal->j_task = current;
136 wake_up(&journal->j_wait_done_commit);
137
138 printk(KERN_INFO "kjournald starting. Commit interval %ld seconds\n",
139 journal->j_commit_interval / HZ);
140
141 /*
142 * And now, wait forever for commit wakeup events.
143 */
144 spin_lock(&journal->j_state_lock);
145
146loop:
147 if (journal->j_flags & JFS_UNMOUNT)
148 goto end_loop;
149
150 jbd_debug(1, "commit_sequence=%d, commit_request=%d\n",
151 journal->j_commit_sequence, journal->j_commit_request);
152
153 if (journal->j_commit_sequence != journal->j_commit_request) {
154 jbd_debug(1, "OK, requests differ\n");
155 spin_unlock(&journal->j_state_lock);
156 del_timer_sync(&journal->j_commit_timer);
157 journal_commit_transaction(journal);
158 spin_lock(&journal->j_state_lock);
159 goto loop;
160 }
161
162 wake_up(&journal->j_wait_done_commit);
163 if (freezing(current)) {
164 /*
165 * The simpler the better. Flushing journal isn't a
166 * good idea, because that depends on threads that may
167 * be already stopped.
168 */
169 jbd_debug(1, "Now suspending kjournald\n");
170 spin_unlock(&journal->j_state_lock);
171 try_to_freeze();
172 spin_lock(&journal->j_state_lock);
173 } else {
174 /*
175 * We assume on resume that commits are already there,
176 * so we don't sleep
177 */
178 DEFINE_WAIT(wait);
179 int should_sleep = 1;
180
181 prepare_to_wait(&journal->j_wait_commit, &wait,
182 TASK_INTERRUPTIBLE);
183 if (journal->j_commit_sequence != journal->j_commit_request)
184 should_sleep = 0;
185 transaction = journal->j_running_transaction;
186 if (transaction && time_after_eq(jiffies,
187 transaction->t_expires))
188 should_sleep = 0;
189 if (journal->j_flags & JFS_UNMOUNT)
190 should_sleep = 0;
191 if (should_sleep) {
192 spin_unlock(&journal->j_state_lock);
193 schedule();
194 spin_lock(&journal->j_state_lock);
195 }
196 finish_wait(&journal->j_wait_commit, &wait);
197 }
198
199 jbd_debug(1, "kjournald wakes\n");
200
201 /*
202 * Were we woken up by a commit wakeup event?
203 */
204 transaction = journal->j_running_transaction;
205 if (transaction && time_after_eq(jiffies, transaction->t_expires)) {
206 journal->j_commit_request = transaction->t_tid;
207 jbd_debug(1, "woke because of timeout\n");
208 }
209 goto loop;
210
211end_loop:
212 spin_unlock(&journal->j_state_lock);
213 del_timer_sync(&journal->j_commit_timer);
214 journal->j_task = NULL;
215 wake_up(&journal->j_wait_done_commit);
216 jbd_debug(1, "Journal thread exiting.\n");
217 return 0;
218}
219
220static int journal_start_thread(journal_t *journal)
221{
222 struct task_struct *t;
223
224 t = kthread_run(kjournald, journal, "kjournald");
225 if (IS_ERR(t))
226 return PTR_ERR(t);
227
228 wait_event(journal->j_wait_done_commit, journal->j_task != NULL);
229 return 0;
230}
231
232static void journal_kill_thread(journal_t *journal)
233{
234 spin_lock(&journal->j_state_lock);
235 journal->j_flags |= JFS_UNMOUNT;
236
237 while (journal->j_task) {
238 wake_up(&journal->j_wait_commit);
239 spin_unlock(&journal->j_state_lock);
240 wait_event(journal->j_wait_done_commit,
241 journal->j_task == NULL);
242 spin_lock(&journal->j_state_lock);
243 }
244 spin_unlock(&journal->j_state_lock);
245}
246
247/*
248 * journal_write_metadata_buffer: write a metadata buffer to the journal.
249 *
250 * Writes a metadata buffer to a given disk block. The actual IO is not
251 * performed but a new buffer_head is constructed which labels the data
252 * to be written with the correct destination disk block.
253 *
254 * Any magic-number escaping which needs to be done will cause a
255 * copy-out here. If the buffer happens to start with the
256 * JFS_MAGIC_NUMBER, then we can't write it to the log directly: the
257 * magic number is only written to the log for descripter blocks. In
258 * this case, we copy the data and replace the first word with 0, and we
259 * return a result code which indicates that this buffer needs to be
260 * marked as an escaped buffer in the corresponding log descriptor
261 * block. The missing word can then be restored when the block is read
262 * during recovery.
263 *
264 * If the source buffer has already been modified by a new transaction
265 * since we took the last commit snapshot, we use the frozen copy of
266 * that data for IO. If we end up using the existing buffer_head's data
267 * for the write, then we *have* to lock the buffer to prevent anyone
268 * else from using and possibly modifying it while the IO is in
269 * progress.
270 *
271 * The function returns a pointer to the buffer_heads to be used for IO.
272 *
273 * We assume that the journal has already been locked in this function.
274 *
275 * Return value:
276 * <0: Error
277 * >=0: Finished OK
278 *
279 * On success:
280 * Bit 0 set == escape performed on the data
281 * Bit 1 set == buffer copy-out performed (kfree the data after IO)
282 */
283
284int journal_write_metadata_buffer(transaction_t *transaction,
285 struct journal_head *jh_in,
286 struct journal_head **jh_out,
287 unsigned int blocknr)
288{
289 int need_copy_out = 0;
290 int done_copy_out = 0;
291 int do_escape = 0;
292 char *mapped_data;
293 struct buffer_head *new_bh;
294 struct journal_head *new_jh;
295 struct page *new_page;
296 unsigned int new_offset;
297 struct buffer_head *bh_in = jh2bh(jh_in);
298 journal_t *journal = transaction->t_journal;
299
300 /*
301 * The buffer really shouldn't be locked: only the current committing
302 * transaction is allowed to write it, so nobody else is allowed
303 * to do any IO.
304 *
305 * akpm: except if we're journalling data, and write() output is
306 * also part of a shared mapping, and another thread has
307 * decided to launch a writepage() against this buffer.
308 */
309 J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in));
310
311 new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL);
312 /* keep subsequent assertions sane */
313 new_bh->b_state = 0;
314 init_buffer(new_bh, NULL, NULL);
315 atomic_set(&new_bh->b_count, 1);
316 new_jh = journal_add_journal_head(new_bh); /* This sleeps */
317
318 /*
319 * If a new transaction has already done a buffer copy-out, then
320 * we use that version of the data for the commit.
321 */
322 jbd_lock_bh_state(bh_in);
323repeat:
324 if (jh_in->b_frozen_data) {
325 done_copy_out = 1;
326 new_page = virt_to_page(jh_in->b_frozen_data);
327 new_offset = offset_in_page(jh_in->b_frozen_data);
328 } else {
329 new_page = jh2bh(jh_in)->b_page;
330 new_offset = offset_in_page(jh2bh(jh_in)->b_data);
331 }
332
333 mapped_data = kmap_atomic(new_page);
334 /*
335 * Check for escaping
336 */
337 if (*((__be32 *)(mapped_data + new_offset)) ==
338 cpu_to_be32(JFS_MAGIC_NUMBER)) {
339 need_copy_out = 1;
340 do_escape = 1;
341 }
342 kunmap_atomic(mapped_data);
343
344 /*
345 * Do we need to do a data copy?
346 */
347 if (need_copy_out && !done_copy_out) {
348 char *tmp;
349
350 jbd_unlock_bh_state(bh_in);
351 tmp = jbd_alloc(bh_in->b_size, GFP_NOFS);
352 jbd_lock_bh_state(bh_in);
353 if (jh_in->b_frozen_data) {
354 jbd_free(tmp, bh_in->b_size);
355 goto repeat;
356 }
357
358 jh_in->b_frozen_data = tmp;
359 mapped_data = kmap_atomic(new_page);
360 memcpy(tmp, mapped_data + new_offset, jh2bh(jh_in)->b_size);
361 kunmap_atomic(mapped_data);
362
363 new_page = virt_to_page(tmp);
364 new_offset = offset_in_page(tmp);
365 done_copy_out = 1;
366 }
367
368 /*
369 * Did we need to do an escaping? Now we've done all the
370 * copying, we can finally do so.
371 */
372 if (do_escape) {
373 mapped_data = kmap_atomic(new_page);
374 *((unsigned int *)(mapped_data + new_offset)) = 0;
375 kunmap_atomic(mapped_data);
376 }
377
378 set_bh_page(new_bh, new_page, new_offset);
379 new_jh->b_transaction = NULL;
380 new_bh->b_size = jh2bh(jh_in)->b_size;
381 new_bh->b_bdev = transaction->t_journal->j_dev;
382 new_bh->b_blocknr = blocknr;
383 set_buffer_mapped(new_bh);
384 set_buffer_dirty(new_bh);
385
386 *jh_out = new_jh;
387
388 /*
389 * The to-be-written buffer needs to get moved to the io queue,
390 * and the original buffer whose contents we are shadowing or
391 * copying is moved to the transaction's shadow queue.
392 */
393 JBUFFER_TRACE(jh_in, "file as BJ_Shadow");
394 spin_lock(&journal->j_list_lock);
395 __journal_file_buffer(jh_in, transaction, BJ_Shadow);
396 spin_unlock(&journal->j_list_lock);
397 jbd_unlock_bh_state(bh_in);
398
399 JBUFFER_TRACE(new_jh, "file as BJ_IO");
400 journal_file_buffer(new_jh, transaction, BJ_IO);
401
402 return do_escape | (done_copy_out << 1);
403}
404
405/*
406 * Allocation code for the journal file. Manage the space left in the
407 * journal, so that we can begin checkpointing when appropriate.
408 */
409
410/*
411 * __log_space_left: Return the number of free blocks left in the journal.
412 *
413 * Called with the journal already locked.
414 *
415 * Called under j_state_lock
416 */
417
418int __log_space_left(journal_t *journal)
419{
420 int left = journal->j_free;
421
422 assert_spin_locked(&journal->j_state_lock);
423
424 /*
425 * Be pessimistic here about the number of those free blocks which
426 * might be required for log descriptor control blocks.
427 */
428
429#define MIN_LOG_RESERVED_BLOCKS 32 /* Allow for rounding errors */
430
431 left -= MIN_LOG_RESERVED_BLOCKS;
432
433 if (left <= 0)
434 return 0;
435 left -= (left >> 3);
436 return left;
437}
438
439/*
440 * Called under j_state_lock. Returns true if a transaction commit was started.
441 */
442int __log_start_commit(journal_t *journal, tid_t target)
443{
444 /*
445 * The only transaction we can possibly wait upon is the
446 * currently running transaction (if it exists). Otherwise,
447 * the target tid must be an old one.
448 */
449 if (journal->j_running_transaction &&
450 journal->j_running_transaction->t_tid == target) {
451 /*
452 * We want a new commit: OK, mark the request and wakeup the
453 * commit thread. We do _not_ do the commit ourselves.
454 */
455
456 journal->j_commit_request = target;
457 jbd_debug(1, "JBD: requesting commit %d/%d\n",
458 journal->j_commit_request,
459 journal->j_commit_sequence);
460 wake_up(&journal->j_wait_commit);
461 return 1;
462 } else if (!tid_geq(journal->j_commit_request, target))
463 /* This should never happen, but if it does, preserve
464 the evidence before kjournald goes into a loop and
465 increments j_commit_sequence beyond all recognition. */
466 WARN_ONCE(1, "jbd: bad log_start_commit: %u %u %u %u\n",
467 journal->j_commit_request, journal->j_commit_sequence,
468 target, journal->j_running_transaction ?
469 journal->j_running_transaction->t_tid : 0);
470 return 0;
471}
472
473int log_start_commit(journal_t *journal, tid_t tid)
474{
475 int ret;
476
477 spin_lock(&journal->j_state_lock);
478 ret = __log_start_commit(journal, tid);
479 spin_unlock(&journal->j_state_lock);
480 return ret;
481}
482
483/*
484 * Force and wait upon a commit if the calling process is not within
485 * transaction. This is used for forcing out undo-protected data which contains
486 * bitmaps, when the fs is running out of space.
487 *
488 * We can only force the running transaction if we don't have an active handle;
489 * otherwise, we will deadlock.
490 *
491 * Returns true if a transaction was started.
492 */
493int journal_force_commit_nested(journal_t *journal)
494{
495 transaction_t *transaction = NULL;
496 tid_t tid;
497
498 spin_lock(&journal->j_state_lock);
499 if (journal->j_running_transaction && !current->journal_info) {
500 transaction = journal->j_running_transaction;
501 __log_start_commit(journal, transaction->t_tid);
502 } else if (journal->j_committing_transaction)
503 transaction = journal->j_committing_transaction;
504
505 if (!transaction) {
506 spin_unlock(&journal->j_state_lock);
507 return 0; /* Nothing to retry */
508 }
509
510 tid = transaction->t_tid;
511 spin_unlock(&journal->j_state_lock);
512 log_wait_commit(journal, tid);
513 return 1;
514}
515
516/*
517 * Start a commit of the current running transaction (if any). Returns true
518 * if a transaction is going to be committed (or is currently already
519 * committing), and fills its tid in at *ptid
520 */
521int journal_start_commit(journal_t *journal, tid_t *ptid)
522{
523 int ret = 0;
524
525 spin_lock(&journal->j_state_lock);
526 if (journal->j_running_transaction) {
527 tid_t tid = journal->j_running_transaction->t_tid;
528
529 __log_start_commit(journal, tid);
530 /* There's a running transaction and we've just made sure
531 * it's commit has been scheduled. */
532 if (ptid)
533 *ptid = tid;
534 ret = 1;
535 } else if (journal->j_committing_transaction) {
536 /*
537 * If ext3_write_super() recently started a commit, then we
538 * have to wait for completion of that transaction
539 */
540 if (ptid)
541 *ptid = journal->j_committing_transaction->t_tid;
542 ret = 1;
543 }
544 spin_unlock(&journal->j_state_lock);
545 return ret;
546}
547
548/*
549 * Wait for a specified commit to complete.
550 * The caller may not hold the journal lock.
551 */
552int log_wait_commit(journal_t *journal, tid_t tid)
553{
554 int err = 0;
555
556#ifdef CONFIG_JBD_DEBUG
557 spin_lock(&journal->j_state_lock);
558 if (!tid_geq(journal->j_commit_request, tid)) {
559 printk(KERN_EMERG
560 "%s: error: j_commit_request=%d, tid=%d\n",
561 __func__, journal->j_commit_request, tid);
562 }
563 spin_unlock(&journal->j_state_lock);
564#endif
565 spin_lock(&journal->j_state_lock);
566 if (!tid_geq(journal->j_commit_waited, tid))
567 journal->j_commit_waited = tid;
568 while (tid_gt(tid, journal->j_commit_sequence)) {
569 jbd_debug(1, "JBD: want %d, j_commit_sequence=%d\n",
570 tid, journal->j_commit_sequence);
571 wake_up(&journal->j_wait_commit);
572 spin_unlock(&journal->j_state_lock);
573 wait_event(journal->j_wait_done_commit,
574 !tid_gt(tid, journal->j_commit_sequence));
575 spin_lock(&journal->j_state_lock);
576 }
577 spin_unlock(&journal->j_state_lock);
578
579 if (unlikely(is_journal_aborted(journal))) {
580 printk(KERN_EMERG "journal commit I/O error\n");
581 err = -EIO;
582 }
583 return err;
584}
585
586/*
587 * Return 1 if a given transaction has not yet sent barrier request
588 * connected with a transaction commit. If 0 is returned, transaction
589 * may or may not have sent the barrier. Used to avoid sending barrier
590 * twice in common cases.
591 */
592int journal_trans_will_send_data_barrier(journal_t *journal, tid_t tid)
593{
594 int ret = 0;
595 transaction_t *commit_trans;
596
597 if (!(journal->j_flags & JFS_BARRIER))
598 return 0;
599 spin_lock(&journal->j_state_lock);
600 /* Transaction already committed? */
601 if (tid_geq(journal->j_commit_sequence, tid))
602 goto out;
603 /*
604 * Transaction is being committed and we already proceeded to
605 * writing commit record?
606 */
607 commit_trans = journal->j_committing_transaction;
608 if (commit_trans && commit_trans->t_tid == tid &&
609 commit_trans->t_state >= T_COMMIT_RECORD)
610 goto out;
611 ret = 1;
612out:
613 spin_unlock(&journal->j_state_lock);
614 return ret;
615}
616EXPORT_SYMBOL(journal_trans_will_send_data_barrier);
617
618/*
619 * Log buffer allocation routines:
620 */
621
622int journal_next_log_block(journal_t *journal, unsigned int *retp)
623{
624 unsigned int blocknr;
625
626 spin_lock(&journal->j_state_lock);
627 J_ASSERT(journal->j_free > 1);
628
629 blocknr = journal->j_head;
630 journal->j_head++;
631 journal->j_free--;
632 if (journal->j_head == journal->j_last)
633 journal->j_head = journal->j_first;
634 spin_unlock(&journal->j_state_lock);
635 return journal_bmap(journal, blocknr, retp);
636}
637
638/*
639 * Conversion of logical to physical block numbers for the journal
640 *
641 * On external journals the journal blocks are identity-mapped, so
642 * this is a no-op. If needed, we can use j_blk_offset - everything is
643 * ready.
644 */
645int journal_bmap(journal_t *journal, unsigned int blocknr,
646 unsigned int *retp)
647{
648 int err = 0;
649 unsigned int ret;
650
651 if (journal->j_inode) {
652 ret = bmap(journal->j_inode, blocknr);
653 if (ret)
654 *retp = ret;
655 else {
656 char b[BDEVNAME_SIZE];
657
658 printk(KERN_ALERT "%s: journal block not found "
659 "at offset %u on %s\n",
660 __func__,
661 blocknr,
662 bdevname(journal->j_dev, b));
663 err = -EIO;
664 __journal_abort_soft(journal, err);
665 }
666 } else {
667 *retp = blocknr; /* +journal->j_blk_offset */
668 }
669 return err;
670}
671
672/*
673 * We play buffer_head aliasing tricks to write data/metadata blocks to
674 * the journal without copying their contents, but for journal
675 * descriptor blocks we do need to generate bona fide buffers.
676 *
677 * After the caller of journal_get_descriptor_buffer() has finished modifying
678 * the buffer's contents they really should run flush_dcache_page(bh->b_page).
679 * But we don't bother doing that, so there will be coherency problems with
680 * mmaps of blockdevs which hold live JBD-controlled filesystems.
681 */
682struct journal_head *journal_get_descriptor_buffer(journal_t *journal)
683{
684 struct buffer_head *bh;
685 unsigned int blocknr;
686 int err;
687
688 err = journal_next_log_block(journal, &blocknr);
689
690 if (err)
691 return NULL;
692
693 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
694 if (!bh)
695 return NULL;
696 lock_buffer(bh);
697 memset(bh->b_data, 0, journal->j_blocksize);
698 set_buffer_uptodate(bh);
699 unlock_buffer(bh);
700 BUFFER_TRACE(bh, "return this buffer");
701 return journal_add_journal_head(bh);
702}
703
704/*
705 * Management for journal control blocks: functions to create and
706 * destroy journal_t structures, and to initialise and read existing
707 * journal blocks from disk. */
708
709/* First: create and setup a journal_t object in memory. We initialise
710 * very few fields yet: that has to wait until we have created the
711 * journal structures from from scratch, or loaded them from disk. */
712
713static journal_t * journal_init_common (void)
714{
715 journal_t *journal;
716 int err;
717
718 journal = kzalloc(sizeof(*journal), GFP_KERNEL);
719 if (!journal)
720 goto fail;
721
722 init_waitqueue_head(&journal->j_wait_transaction_locked);
723 init_waitqueue_head(&journal->j_wait_logspace);
724 init_waitqueue_head(&journal->j_wait_done_commit);
725 init_waitqueue_head(&journal->j_wait_checkpoint);
726 init_waitqueue_head(&journal->j_wait_commit);
727 init_waitqueue_head(&journal->j_wait_updates);
728 mutex_init(&journal->j_checkpoint_mutex);
729 spin_lock_init(&journal->j_revoke_lock);
730 spin_lock_init(&journal->j_list_lock);
731 spin_lock_init(&journal->j_state_lock);
732
733 journal->j_commit_interval = (HZ * JBD_DEFAULT_MAX_COMMIT_AGE);
734
735 /* The journal is marked for error until we succeed with recovery! */
736 journal->j_flags = JFS_ABORT;
737
738 /* Set up a default-sized revoke table for the new mount. */
739 err = journal_init_revoke(journal, JOURNAL_REVOKE_DEFAULT_HASH);
740 if (err) {
741 kfree(journal);
742 goto fail;
743 }
744 return journal;
745fail:
746 return NULL;
747}
748
749/* journal_init_dev and journal_init_inode:
750 *
751 * Create a journal structure assigned some fixed set of disk blocks to
752 * the journal. We don't actually touch those disk blocks yet, but we
753 * need to set up all of the mapping information to tell the journaling
754 * system where the journal blocks are.
755 *
756 */
757
758/**
759 * journal_t * journal_init_dev() - creates and initialises a journal structure
760 * @bdev: Block device on which to create the journal
761 * @fs_dev: Device which hold journalled filesystem for this journal.
762 * @start: Block nr Start of journal.
763 * @len: Length of the journal in blocks.
764 * @blocksize: blocksize of journalling device
765 *
766 * Returns: a newly created journal_t *
767 *
768 * journal_init_dev creates a journal which maps a fixed contiguous
769 * range of blocks on an arbitrary block device.
770 *
771 */
772journal_t * journal_init_dev(struct block_device *bdev,
773 struct block_device *fs_dev,
774 int start, int len, int blocksize)
775{
776 journal_t *journal = journal_init_common();
777 struct buffer_head *bh;
778 int n;
779
780 if (!journal)
781 return NULL;
782
783 /* journal descriptor can store up to n blocks -bzzz */
784 journal->j_blocksize = blocksize;
785 n = journal->j_blocksize / sizeof(journal_block_tag_t);
786 journal->j_wbufsize = n;
787 journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
788 if (!journal->j_wbuf) {
789 printk(KERN_ERR "%s: Can't allocate bhs for commit thread\n",
790 __func__);
791 goto out_err;
792 }
793 journal->j_dev = bdev;
794 journal->j_fs_dev = fs_dev;
795 journal->j_blk_offset = start;
796 journal->j_maxlen = len;
797
798 bh = __getblk(journal->j_dev, start, journal->j_blocksize);
799 if (!bh) {
800 printk(KERN_ERR
801 "%s: Cannot get buffer for journal superblock\n",
802 __func__);
803 goto out_err;
804 }
805 journal->j_sb_buffer = bh;
806 journal->j_superblock = (journal_superblock_t *)bh->b_data;
807
808 return journal;
809out_err:
810 kfree(journal->j_wbuf);
811 kfree(journal);
812 return NULL;
813}
814
815/**
816 * journal_t * journal_init_inode () - creates a journal which maps to a inode.
817 * @inode: An inode to create the journal in
818 *
819 * journal_init_inode creates a journal which maps an on-disk inode as
820 * the journal. The inode must exist already, must support bmap() and
821 * must have all data blocks preallocated.
822 */
823journal_t * journal_init_inode (struct inode *inode)
824{
825 struct buffer_head *bh;
826 journal_t *journal = journal_init_common();
827 int err;
828 int n;
829 unsigned int blocknr;
830
831 if (!journal)
832 return NULL;
833
834 journal->j_dev = journal->j_fs_dev = inode->i_sb->s_bdev;
835 journal->j_inode = inode;
836 jbd_debug(1,
837 "journal %p: inode %s/%ld, size %Ld, bits %d, blksize %ld\n",
838 journal, inode->i_sb->s_id, inode->i_ino,
839 (long long) inode->i_size,
840 inode->i_sb->s_blocksize_bits, inode->i_sb->s_blocksize);
841
842 journal->j_maxlen = inode->i_size >> inode->i_sb->s_blocksize_bits;
843 journal->j_blocksize = inode->i_sb->s_blocksize;
844
845 /* journal descriptor can store up to n blocks -bzzz */
846 n = journal->j_blocksize / sizeof(journal_block_tag_t);
847 journal->j_wbufsize = n;
848 journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
849 if (!journal->j_wbuf) {
850 printk(KERN_ERR "%s: Can't allocate bhs for commit thread\n",
851 __func__);
852 goto out_err;
853 }
854
855 err = journal_bmap(journal, 0, &blocknr);
856 /* If that failed, give up */
857 if (err) {
858 printk(KERN_ERR "%s: Cannot locate journal superblock\n",
859 __func__);
860 goto out_err;
861 }
862
863 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
864 if (!bh) {
865 printk(KERN_ERR
866 "%s: Cannot get buffer for journal superblock\n",
867 __func__);
868 goto out_err;
869 }
870 journal->j_sb_buffer = bh;
871 journal->j_superblock = (journal_superblock_t *)bh->b_data;
872
873 return journal;
874out_err:
875 kfree(journal->j_wbuf);
876 kfree(journal);
877 return NULL;
878}
879
880/*
881 * If the journal init or create aborts, we need to mark the journal
882 * superblock as being NULL to prevent the journal destroy from writing
883 * back a bogus superblock.
884 */
885static void journal_fail_superblock (journal_t *journal)
886{
887 struct buffer_head *bh = journal->j_sb_buffer;
888 brelse(bh);
889 journal->j_sb_buffer = NULL;
890}
891
892/*
893 * Given a journal_t structure, initialise the various fields for
894 * startup of a new journaling session. We use this both when creating
895 * a journal, and after recovering an old journal to reset it for
896 * subsequent use.
897 */
898
899static int journal_reset(journal_t *journal)
900{
901 journal_superblock_t *sb = journal->j_superblock;
902 unsigned int first, last;
903
904 first = be32_to_cpu(sb->s_first);
905 last = be32_to_cpu(sb->s_maxlen);
906 if (first + JFS_MIN_JOURNAL_BLOCKS > last + 1) {
907 printk(KERN_ERR "JBD: Journal too short (blocks %u-%u).\n",
908 first, last);
909 journal_fail_superblock(journal);
910 return -EINVAL;
911 }
912
913 journal->j_first = first;
914 journal->j_last = last;
915
916 journal->j_head = first;
917 journal->j_tail = first;
918 journal->j_free = last - first;
919
920 journal->j_tail_sequence = journal->j_transaction_sequence;
921 journal->j_commit_sequence = journal->j_transaction_sequence - 1;
922 journal->j_commit_request = journal->j_commit_sequence;
923
924 journal->j_max_transaction_buffers = journal->j_maxlen / 4;
925
926 /*
927 * As a special case, if the on-disk copy is already marked as needing
928 * no recovery (s_start == 0), then we can safely defer the superblock
929 * update until the next commit by setting JFS_FLUSHED. This avoids
930 * attempting a write to a potential-readonly device.
931 */
932 if (sb->s_start == 0) {
933 jbd_debug(1,"JBD: Skipping superblock update on recovered sb "
934 "(start %u, seq %d, errno %d)\n",
935 journal->j_tail, journal->j_tail_sequence,
936 journal->j_errno);
937 journal->j_flags |= JFS_FLUSHED;
938 } else {
939 /* Lock here to make assertions happy... */
940 mutex_lock(&journal->j_checkpoint_mutex);
941 /*
942 * Update log tail information. We use WRITE_FUA since new
943 * transaction will start reusing journal space and so we
944 * must make sure information about current log tail is on
945 * disk before that.
946 */
947 journal_update_sb_log_tail(journal,
948 journal->j_tail_sequence,
949 journal->j_tail,
950 WRITE_FUA);
951 mutex_unlock(&journal->j_checkpoint_mutex);
952 }
953 return journal_start_thread(journal);
954}
955
956/**
957 * int journal_create() - Initialise the new journal file
958 * @journal: Journal to create. This structure must have been initialised
959 *
960 * Given a journal_t structure which tells us which disk blocks we can
961 * use, create a new journal superblock and initialise all of the
962 * journal fields from scratch.
963 **/
964int journal_create(journal_t *journal)
965{
966 unsigned int blocknr;
967 struct buffer_head *bh;
968 journal_superblock_t *sb;
969 int i, err;
970
971 if (journal->j_maxlen < JFS_MIN_JOURNAL_BLOCKS) {
972 printk (KERN_ERR "Journal length (%d blocks) too short.\n",
973 journal->j_maxlen);
974 journal_fail_superblock(journal);
975 return -EINVAL;
976 }
977
978 if (journal->j_inode == NULL) {
979 /*
980 * We don't know what block to start at!
981 */
982 printk(KERN_EMERG
983 "%s: creation of journal on external device!\n",
984 __func__);
985 BUG();
986 }
987
988 /* Zero out the entire journal on disk. We cannot afford to
989 have any blocks on disk beginning with JFS_MAGIC_NUMBER. */
990 jbd_debug(1, "JBD: Zeroing out journal blocks...\n");
991 for (i = 0; i < journal->j_maxlen; i++) {
992 err = journal_bmap(journal, i, &blocknr);
993 if (err)
994 return err;
995 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
996 if (unlikely(!bh))
997 return -ENOMEM;
998 lock_buffer(bh);
999 memset (bh->b_data, 0, journal->j_blocksize);
1000 BUFFER_TRACE(bh, "marking dirty");
1001 mark_buffer_dirty(bh);
1002 BUFFER_TRACE(bh, "marking uptodate");
1003 set_buffer_uptodate(bh);
1004 unlock_buffer(bh);
1005 __brelse(bh);
1006 }
1007
1008 sync_blockdev(journal->j_dev);
1009 jbd_debug(1, "JBD: journal cleared.\n");
1010
1011 /* OK, fill in the initial static fields in the new superblock */
1012 sb = journal->j_superblock;
1013
1014 sb->s_header.h_magic = cpu_to_be32(JFS_MAGIC_NUMBER);
1015 sb->s_header.h_blocktype = cpu_to_be32(JFS_SUPERBLOCK_V2);
1016
1017 sb->s_blocksize = cpu_to_be32(journal->j_blocksize);
1018 sb->s_maxlen = cpu_to_be32(journal->j_maxlen);
1019 sb->s_first = cpu_to_be32(1);
1020
1021 journal->j_transaction_sequence = 1;
1022
1023 journal->j_flags &= ~JFS_ABORT;
1024 journal->j_format_version = 2;
1025
1026 return journal_reset(journal);
1027}
1028
1029static void journal_write_superblock(journal_t *journal, int write_op)
1030{
1031 struct buffer_head *bh = journal->j_sb_buffer;
1032 int ret;
1033
1034 trace_journal_write_superblock(journal, write_op);
1035 if (!(journal->j_flags & JFS_BARRIER))
1036 write_op &= ~(REQ_FUA | REQ_FLUSH);
1037 lock_buffer(bh);
1038 if (buffer_write_io_error(bh)) {
1039 char b[BDEVNAME_SIZE];
1040 /*
1041 * Oh, dear. A previous attempt to write the journal
1042 * superblock failed. This could happen because the
1043 * USB device was yanked out. Or it could happen to
1044 * be a transient write error and maybe the block will
1045 * be remapped. Nothing we can do but to retry the
1046 * write and hope for the best.
1047 */
1048 printk(KERN_ERR "JBD: previous I/O error detected "
1049 "for journal superblock update for %s.\n",
1050 journal_dev_name(journal, b));
1051 clear_buffer_write_io_error(bh);
1052 set_buffer_uptodate(bh);
1053 }
1054
1055 get_bh(bh);
1056 bh->b_end_io = end_buffer_write_sync;
1057 ret = submit_bh(write_op, bh);
1058 wait_on_buffer(bh);
1059 if (buffer_write_io_error(bh)) {
1060 clear_buffer_write_io_error(bh);
1061 set_buffer_uptodate(bh);
1062 ret = -EIO;
1063 }
1064 if (ret) {
1065 char b[BDEVNAME_SIZE];
1066 printk(KERN_ERR "JBD: Error %d detected "
1067 "when updating journal superblock for %s.\n",
1068 ret, journal_dev_name(journal, b));
1069 }
1070}
1071
1072/**
1073 * journal_update_sb_log_tail() - Update log tail in journal sb on disk.
1074 * @journal: The journal to update.
1075 * @tail_tid: TID of the new transaction at the tail of the log
1076 * @tail_block: The first block of the transaction at the tail of the log
1077 * @write_op: With which operation should we write the journal sb
1078 *
1079 * Update a journal's superblock information about log tail and write it to
1080 * disk, waiting for the IO to complete.
1081 */
1082void journal_update_sb_log_tail(journal_t *journal, tid_t tail_tid,
1083 unsigned int tail_block, int write_op)
1084{
1085 journal_superblock_t *sb = journal->j_superblock;
1086
1087 BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
1088 jbd_debug(1,"JBD: updating superblock (start %u, seq %u)\n",
1089 tail_block, tail_tid);
1090
1091 sb->s_sequence = cpu_to_be32(tail_tid);
1092 sb->s_start = cpu_to_be32(tail_block);
1093
1094 journal_write_superblock(journal, write_op);
1095
1096 /* Log is no longer empty */
1097 spin_lock(&journal->j_state_lock);
1098 WARN_ON(!sb->s_sequence);
1099 journal->j_flags &= ~JFS_FLUSHED;
1100 spin_unlock(&journal->j_state_lock);
1101}
1102
1103/**
1104 * mark_journal_empty() - Mark on disk journal as empty.
1105 * @journal: The journal to update.
1106 *
1107 * Update a journal's dynamic superblock fields to show that journal is empty.
1108 * Write updated superblock to disk waiting for IO to complete.
1109 */
1110static void mark_journal_empty(journal_t *journal)
1111{
1112 journal_superblock_t *sb = journal->j_superblock;
1113
1114 BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
1115 spin_lock(&journal->j_state_lock);
1116 /* Is it already empty? */
1117 if (sb->s_start == 0) {
1118 spin_unlock(&journal->j_state_lock);
1119 return;
1120 }
1121 jbd_debug(1, "JBD: Marking journal as empty (seq %d)\n",
1122 journal->j_tail_sequence);
1123
1124 sb->s_sequence = cpu_to_be32(journal->j_tail_sequence);
1125 sb->s_start = cpu_to_be32(0);
1126 spin_unlock(&journal->j_state_lock);
1127
1128 journal_write_superblock(journal, WRITE_FUA);
1129
1130 spin_lock(&journal->j_state_lock);
1131 /* Log is empty */
1132 journal->j_flags |= JFS_FLUSHED;
1133 spin_unlock(&journal->j_state_lock);
1134}
1135
1136/**
1137 * journal_update_sb_errno() - Update error in the journal.
1138 * @journal: The journal to update.
1139 *
1140 * Update a journal's errno. Write updated superblock to disk waiting for IO
1141 * to complete.
1142 */
1143static void journal_update_sb_errno(journal_t *journal)
1144{
1145 journal_superblock_t *sb = journal->j_superblock;
1146
1147 spin_lock(&journal->j_state_lock);
1148 jbd_debug(1, "JBD: updating superblock error (errno %d)\n",
1149 journal->j_errno);
1150 sb->s_errno = cpu_to_be32(journal->j_errno);
1151 spin_unlock(&journal->j_state_lock);
1152
1153 journal_write_superblock(journal, WRITE_SYNC);
1154}
1155
1156/*
1157 * Read the superblock for a given journal, performing initial
1158 * validation of the format.
1159 */
1160
1161static int journal_get_superblock(journal_t *journal)
1162{
1163 struct buffer_head *bh;
1164 journal_superblock_t *sb;
1165 int err = -EIO;
1166
1167 bh = journal->j_sb_buffer;
1168
1169 J_ASSERT(bh != NULL);
1170 if (!buffer_uptodate(bh)) {
1171 ll_rw_block(READ, 1, &bh);
1172 wait_on_buffer(bh);
1173 if (!buffer_uptodate(bh)) {
1174 printk (KERN_ERR
1175 "JBD: IO error reading journal superblock\n");
1176 goto out;
1177 }
1178 }
1179
1180 sb = journal->j_superblock;
1181
1182 err = -EINVAL;
1183
1184 if (sb->s_header.h_magic != cpu_to_be32(JFS_MAGIC_NUMBER) ||
1185 sb->s_blocksize != cpu_to_be32(journal->j_blocksize)) {
1186 printk(KERN_WARNING "JBD: no valid journal superblock found\n");
1187 goto out;
1188 }
1189
1190 switch(be32_to_cpu(sb->s_header.h_blocktype)) {
1191 case JFS_SUPERBLOCK_V1:
1192 journal->j_format_version = 1;
1193 break;
1194 case JFS_SUPERBLOCK_V2:
1195 journal->j_format_version = 2;
1196 break;
1197 default:
1198 printk(KERN_WARNING "JBD: unrecognised superblock format ID\n");
1199 goto out;
1200 }
1201
1202 if (be32_to_cpu(sb->s_maxlen) < journal->j_maxlen)
1203 journal->j_maxlen = be32_to_cpu(sb->s_maxlen);
1204 else if (be32_to_cpu(sb->s_maxlen) > journal->j_maxlen) {
1205 printk (KERN_WARNING "JBD: journal file too short\n");
1206 goto out;
1207 }
1208
1209 if (be32_to_cpu(sb->s_first) == 0 ||
1210 be32_to_cpu(sb->s_first) >= journal->j_maxlen) {
1211 printk(KERN_WARNING
1212 "JBD: Invalid start block of journal: %u\n",
1213 be32_to_cpu(sb->s_first));
1214 goto out;
1215 }
1216
1217 return 0;
1218
1219out:
1220 journal_fail_superblock(journal);
1221 return err;
1222}
1223
1224/*
1225 * Load the on-disk journal superblock and read the key fields into the
1226 * journal_t.
1227 */
1228
1229static int load_superblock(journal_t *journal)
1230{
1231 int err;
1232 journal_superblock_t *sb;
1233
1234 err = journal_get_superblock(journal);
1235 if (err)
1236 return err;
1237
1238 sb = journal->j_superblock;
1239
1240 journal->j_tail_sequence = be32_to_cpu(sb->s_sequence);
1241 journal->j_tail = be32_to_cpu(sb->s_start);
1242 journal->j_first = be32_to_cpu(sb->s_first);
1243 journal->j_last = be32_to_cpu(sb->s_maxlen);
1244 journal->j_errno = be32_to_cpu(sb->s_errno);
1245
1246 return 0;
1247}
1248
1249
1250/**
1251 * int journal_load() - Read journal from disk.
1252 * @journal: Journal to act on.
1253 *
1254 * Given a journal_t structure which tells us which disk blocks contain
1255 * a journal, read the journal from disk to initialise the in-memory
1256 * structures.
1257 */
1258int journal_load(journal_t *journal)
1259{
1260 int err;
1261 journal_superblock_t *sb;
1262
1263 err = load_superblock(journal);
1264 if (err)
1265 return err;
1266
1267 sb = journal->j_superblock;
1268 /* If this is a V2 superblock, then we have to check the
1269 * features flags on it. */
1270
1271 if (journal->j_format_version >= 2) {
1272 if ((sb->s_feature_ro_compat &
1273 ~cpu_to_be32(JFS_KNOWN_ROCOMPAT_FEATURES)) ||
1274 (sb->s_feature_incompat &
1275 ~cpu_to_be32(JFS_KNOWN_INCOMPAT_FEATURES))) {
1276 printk (KERN_WARNING
1277 "JBD: Unrecognised features on journal\n");
1278 return -EINVAL;
1279 }
1280 }
1281
1282 /* Let the recovery code check whether it needs to recover any
1283 * data from the journal. */
1284 if (journal_recover(journal))
1285 goto recovery_error;
1286
1287 /* OK, we've finished with the dynamic journal bits:
1288 * reinitialise the dynamic contents of the superblock in memory
1289 * and reset them on disk. */
1290 if (journal_reset(journal))
1291 goto recovery_error;
1292
1293 journal->j_flags &= ~JFS_ABORT;
1294 journal->j_flags |= JFS_LOADED;
1295 return 0;
1296
1297recovery_error:
1298 printk (KERN_WARNING "JBD: recovery failed\n");
1299 return -EIO;
1300}
1301
1302/**
1303 * void journal_destroy() - Release a journal_t structure.
1304 * @journal: Journal to act on.
1305 *
1306 * Release a journal_t structure once it is no longer in use by the
1307 * journaled object.
1308 * Return <0 if we couldn't clean up the journal.
1309 */
1310int journal_destroy(journal_t *journal)
1311{
1312 int err = 0;
1313
1314
1315 /* Wait for the commit thread to wake up and die. */
1316 journal_kill_thread(journal);
1317
1318 /* Force a final log commit */
1319 if (journal->j_running_transaction)
1320 journal_commit_transaction(journal);
1321
1322 /* Force any old transactions to disk */
1323
1324 /* We cannot race with anybody but must keep assertions happy */
1325 mutex_lock(&journal->j_checkpoint_mutex);
1326 /* Totally anal locking here... */
1327 spin_lock(&journal->j_list_lock);
1328 while (journal->j_checkpoint_transactions != NULL) {
1329 spin_unlock(&journal->j_list_lock);
1330 log_do_checkpoint(journal);
1331 spin_lock(&journal->j_list_lock);
1332 }
1333
1334 J_ASSERT(journal->j_running_transaction == NULL);
1335 J_ASSERT(journal->j_committing_transaction == NULL);
1336 J_ASSERT(journal->j_checkpoint_transactions == NULL);
1337 spin_unlock(&journal->j_list_lock);
1338
1339 if (journal->j_sb_buffer) {
1340 if (!is_journal_aborted(journal)) {
1341 journal->j_tail_sequence =
1342 ++journal->j_transaction_sequence;
1343 mark_journal_empty(journal);
1344 } else
1345 err = -EIO;
1346 brelse(journal->j_sb_buffer);
1347 }
1348 mutex_unlock(&journal->j_checkpoint_mutex);
1349
1350 if (journal->j_inode)
1351 iput(journal->j_inode);
1352 if (journal->j_revoke)
1353 journal_destroy_revoke(journal);
1354 kfree(journal->j_wbuf);
1355 kfree(journal);
1356
1357 return err;
1358}
1359
1360
1361/**
1362 *int journal_check_used_features () - Check if features specified are used.
1363 * @journal: Journal to check.
1364 * @compat: bitmask of compatible features
1365 * @ro: bitmask of features that force read-only mount
1366 * @incompat: bitmask of incompatible features
1367 *
1368 * Check whether the journal uses all of a given set of
1369 * features. Return true (non-zero) if it does.
1370 **/
1371
1372int journal_check_used_features (journal_t *journal, unsigned long compat,
1373 unsigned long ro, unsigned long incompat)
1374{
1375 journal_superblock_t *sb;
1376
1377 if (!compat && !ro && !incompat)
1378 return 1;
1379 if (journal->j_format_version == 1)
1380 return 0;
1381
1382 sb = journal->j_superblock;
1383
1384 if (((be32_to_cpu(sb->s_feature_compat) & compat) == compat) &&
1385 ((be32_to_cpu(sb->s_feature_ro_compat) & ro) == ro) &&
1386 ((be32_to_cpu(sb->s_feature_incompat) & incompat) == incompat))
1387 return 1;
1388
1389 return 0;
1390}
1391
1392/**
1393 * int journal_check_available_features() - Check feature set in journalling layer
1394 * @journal: Journal to check.
1395 * @compat: bitmask of compatible features
1396 * @ro: bitmask of features that force read-only mount
1397 * @incompat: bitmask of incompatible features
1398 *
1399 * Check whether the journaling code supports the use of
1400 * all of a given set of features on this journal. Return true
1401 * (non-zero) if it can. */
1402
1403int journal_check_available_features (journal_t *journal, unsigned long compat,
1404 unsigned long ro, unsigned long incompat)
1405{
1406 if (!compat && !ro && !incompat)
1407 return 1;
1408
1409 /* We can support any known requested features iff the
1410 * superblock is in version 2. Otherwise we fail to support any
1411 * extended sb features. */
1412
1413 if (journal->j_format_version != 2)
1414 return 0;
1415
1416 if ((compat & JFS_KNOWN_COMPAT_FEATURES) == compat &&
1417 (ro & JFS_KNOWN_ROCOMPAT_FEATURES) == ro &&
1418 (incompat & JFS_KNOWN_INCOMPAT_FEATURES) == incompat)
1419 return 1;
1420
1421 return 0;
1422}
1423
1424/**
1425 * int journal_set_features () - Mark a given journal feature in the superblock
1426 * @journal: Journal to act on.
1427 * @compat: bitmask of compatible features
1428 * @ro: bitmask of features that force read-only mount
1429 * @incompat: bitmask of incompatible features
1430 *
1431 * Mark a given journal feature as present on the
1432 * superblock. Returns true if the requested features could be set.
1433 *
1434 */
1435
1436int journal_set_features (journal_t *journal, unsigned long compat,
1437 unsigned long ro, unsigned long incompat)
1438{
1439 journal_superblock_t *sb;
1440
1441 if (journal_check_used_features(journal, compat, ro, incompat))
1442 return 1;
1443
1444 if (!journal_check_available_features(journal, compat, ro, incompat))
1445 return 0;
1446
1447 jbd_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n",
1448 compat, ro, incompat);
1449
1450 sb = journal->j_superblock;
1451
1452 sb->s_feature_compat |= cpu_to_be32(compat);
1453 sb->s_feature_ro_compat |= cpu_to_be32(ro);
1454 sb->s_feature_incompat |= cpu_to_be32(incompat);
1455
1456 return 1;
1457}
1458
1459
1460/**
1461 * int journal_update_format () - Update on-disk journal structure.
1462 * @journal: Journal to act on.
1463 *
1464 * Given an initialised but unloaded journal struct, poke about in the
1465 * on-disk structure to update it to the most recent supported version.
1466 */
1467int journal_update_format (journal_t *journal)
1468{
1469 journal_superblock_t *sb;
1470 int err;
1471
1472 err = journal_get_superblock(journal);
1473 if (err)
1474 return err;
1475
1476 sb = journal->j_superblock;
1477
1478 switch (be32_to_cpu(sb->s_header.h_blocktype)) {
1479 case JFS_SUPERBLOCK_V2:
1480 return 0;
1481 case JFS_SUPERBLOCK_V1:
1482 return journal_convert_superblock_v1(journal, sb);
1483 default:
1484 break;
1485 }
1486 return -EINVAL;
1487}
1488
1489static int journal_convert_superblock_v1(journal_t *journal,
1490 journal_superblock_t *sb)
1491{
1492 int offset, blocksize;
1493 struct buffer_head *bh;
1494
1495 printk(KERN_WARNING
1496 "JBD: Converting superblock from version 1 to 2.\n");
1497
1498 /* Pre-initialise new fields to zero */
1499 offset = ((char *) &(sb->s_feature_compat)) - ((char *) sb);
1500 blocksize = be32_to_cpu(sb->s_blocksize);
1501 memset(&sb->s_feature_compat, 0, blocksize-offset);
1502
1503 sb->s_nr_users = cpu_to_be32(1);
1504 sb->s_header.h_blocktype = cpu_to_be32(JFS_SUPERBLOCK_V2);
1505 journal->j_format_version = 2;
1506
1507 bh = journal->j_sb_buffer;
1508 BUFFER_TRACE(bh, "marking dirty");
1509 mark_buffer_dirty(bh);
1510 sync_dirty_buffer(bh);
1511 return 0;
1512}
1513
1514
1515/**
1516 * int journal_flush () - Flush journal
1517 * @journal: Journal to act on.
1518 *
1519 * Flush all data for a given journal to disk and empty the journal.
1520 * Filesystems can use this when remounting readonly to ensure that
1521 * recovery does not need to happen on remount.
1522 */
1523
1524int journal_flush(journal_t *journal)
1525{
1526 int err = 0;
1527 transaction_t *transaction = NULL;
1528
1529 spin_lock(&journal->j_state_lock);
1530
1531 /* Force everything buffered to the log... */
1532 if (journal->j_running_transaction) {
1533 transaction = journal->j_running_transaction;
1534 __log_start_commit(journal, transaction->t_tid);
1535 } else if (journal->j_committing_transaction)
1536 transaction = journal->j_committing_transaction;
1537
1538 /* Wait for the log commit to complete... */
1539 if (transaction) {
1540 tid_t tid = transaction->t_tid;
1541
1542 spin_unlock(&journal->j_state_lock);
1543 log_wait_commit(journal, tid);
1544 } else {
1545 spin_unlock(&journal->j_state_lock);
1546 }
1547
1548 /* ...and flush everything in the log out to disk. */
1549 spin_lock(&journal->j_list_lock);
1550 while (!err && journal->j_checkpoint_transactions != NULL) {
1551 spin_unlock(&journal->j_list_lock);
1552 mutex_lock(&journal->j_checkpoint_mutex);
1553 err = log_do_checkpoint(journal);
1554 mutex_unlock(&journal->j_checkpoint_mutex);
1555 spin_lock(&journal->j_list_lock);
1556 }
1557 spin_unlock(&journal->j_list_lock);
1558
1559 if (is_journal_aborted(journal))
1560 return -EIO;
1561
1562 mutex_lock(&journal->j_checkpoint_mutex);
1563 cleanup_journal_tail(journal);
1564
1565 /* Finally, mark the journal as really needing no recovery.
1566 * This sets s_start==0 in the underlying superblock, which is
1567 * the magic code for a fully-recovered superblock. Any future
1568 * commits of data to the journal will restore the current
1569 * s_start value. */
1570 mark_journal_empty(journal);
1571 mutex_unlock(&journal->j_checkpoint_mutex);
1572 spin_lock(&journal->j_state_lock);
1573 J_ASSERT(!journal->j_running_transaction);
1574 J_ASSERT(!journal->j_committing_transaction);
1575 J_ASSERT(!journal->j_checkpoint_transactions);
1576 J_ASSERT(journal->j_head == journal->j_tail);
1577 J_ASSERT(journal->j_tail_sequence == journal->j_transaction_sequence);
1578 spin_unlock(&journal->j_state_lock);
1579 return 0;
1580}
1581
1582/**
1583 * int journal_wipe() - Wipe journal contents
1584 * @journal: Journal to act on.
1585 * @write: flag (see below)
1586 *
1587 * Wipe out all of the contents of a journal, safely. This will produce
1588 * a warning if the journal contains any valid recovery information.
1589 * Must be called between journal_init_*() and journal_load().
1590 *
1591 * If 'write' is non-zero, then we wipe out the journal on disk; otherwise
1592 * we merely suppress recovery.
1593 */
1594
1595int journal_wipe(journal_t *journal, int write)
1596{
1597 int err = 0;
1598
1599 J_ASSERT (!(journal->j_flags & JFS_LOADED));
1600
1601 err = load_superblock(journal);
1602 if (err)
1603 return err;
1604
1605 if (!journal->j_tail)
1606 goto no_recovery;
1607
1608 printk (KERN_WARNING "JBD: %s recovery information on journal\n",
1609 write ? "Clearing" : "Ignoring");
1610
1611 err = journal_skip_recovery(journal);
1612 if (write) {
1613 /* Lock to make assertions happy... */
1614 mutex_lock(&journal->j_checkpoint_mutex);
1615 mark_journal_empty(journal);
1616 mutex_unlock(&journal->j_checkpoint_mutex);
1617 }
1618
1619 no_recovery:
1620 return err;
1621}
1622
1623/*
1624 * journal_dev_name: format a character string to describe on what
1625 * device this journal is present.
1626 */
1627
1628static const char *journal_dev_name(journal_t *journal, char *buffer)
1629{
1630 struct block_device *bdev;
1631
1632 if (journal->j_inode)
1633 bdev = journal->j_inode->i_sb->s_bdev;
1634 else
1635 bdev = journal->j_dev;
1636
1637 return bdevname(bdev, buffer);
1638}
1639
1640/*
1641 * Journal abort has very specific semantics, which we describe
1642 * for journal abort.
1643 *
1644 * Two internal function, which provide abort to te jbd layer
1645 * itself are here.
1646 */
1647
1648/*
1649 * Quick version for internal journal use (doesn't lock the journal).
1650 * Aborts hard --- we mark the abort as occurred, but do _nothing_ else,
1651 * and don't attempt to make any other journal updates.
1652 */
1653static void __journal_abort_hard(journal_t *journal)
1654{
1655 transaction_t *transaction;
1656 char b[BDEVNAME_SIZE];
1657
1658 if (journal->j_flags & JFS_ABORT)
1659 return;
1660
1661 printk(KERN_ERR "Aborting journal on device %s.\n",
1662 journal_dev_name(journal, b));
1663
1664 spin_lock(&journal->j_state_lock);
1665 journal->j_flags |= JFS_ABORT;
1666 transaction = journal->j_running_transaction;
1667 if (transaction)
1668 __log_start_commit(journal, transaction->t_tid);
1669 spin_unlock(&journal->j_state_lock);
1670}
1671
1672/* Soft abort: record the abort error status in the journal superblock,
1673 * but don't do any other IO. */
1674static void __journal_abort_soft (journal_t *journal, int errno)
1675{
1676 if (journal->j_flags & JFS_ABORT)
1677 return;
1678
1679 if (!journal->j_errno)
1680 journal->j_errno = errno;
1681
1682 __journal_abort_hard(journal);
1683
1684 if (errno)
1685 journal_update_sb_errno(journal);
1686}
1687
1688/**
1689 * void journal_abort () - Shutdown the journal immediately.
1690 * @journal: the journal to shutdown.
1691 * @errno: an error number to record in the journal indicating
1692 * the reason for the shutdown.
1693 *
1694 * Perform a complete, immediate shutdown of the ENTIRE
1695 * journal (not of a single transaction). This operation cannot be
1696 * undone without closing and reopening the journal.
1697 *
1698 * The journal_abort function is intended to support higher level error
1699 * recovery mechanisms such as the ext2/ext3 remount-readonly error
1700 * mode.
1701 *
1702 * Journal abort has very specific semantics. Any existing dirty,
1703 * unjournaled buffers in the main filesystem will still be written to
1704 * disk by bdflush, but the journaling mechanism will be suspended
1705 * immediately and no further transaction commits will be honoured.
1706 *
1707 * Any dirty, journaled buffers will be written back to disk without
1708 * hitting the journal. Atomicity cannot be guaranteed on an aborted
1709 * filesystem, but we _do_ attempt to leave as much data as possible
1710 * behind for fsck to use for cleanup.
1711 *
1712 * Any attempt to get a new transaction handle on a journal which is in
1713 * ABORT state will just result in an -EROFS error return. A
1714 * journal_stop on an existing handle will return -EIO if we have
1715 * entered abort state during the update.
1716 *
1717 * Recursive transactions are not disturbed by journal abort until the
1718 * final journal_stop, which will receive the -EIO error.
1719 *
1720 * Finally, the journal_abort call allows the caller to supply an errno
1721 * which will be recorded (if possible) in the journal superblock. This
1722 * allows a client to record failure conditions in the middle of a
1723 * transaction without having to complete the transaction to record the
1724 * failure to disk. ext3_error, for example, now uses this
1725 * functionality.
1726 *
1727 * Errors which originate from within the journaling layer will NOT
1728 * supply an errno; a null errno implies that absolutely no further
1729 * writes are done to the journal (unless there are any already in
1730 * progress).
1731 *
1732 */
1733
1734void journal_abort(journal_t *journal, int errno)
1735{
1736 __journal_abort_soft(journal, errno);
1737}
1738
1739/**
1740 * int journal_errno () - returns the journal's error state.
1741 * @journal: journal to examine.
1742 *
1743 * This is the errno numbet set with journal_abort(), the last
1744 * time the journal was mounted - if the journal was stopped
1745 * without calling abort this will be 0.
1746 *
1747 * If the journal has been aborted on this mount time -EROFS will
1748 * be returned.
1749 */
1750int journal_errno(journal_t *journal)
1751{
1752 int err;
1753
1754 spin_lock(&journal->j_state_lock);
1755 if (journal->j_flags & JFS_ABORT)
1756 err = -EROFS;
1757 else
1758 err = journal->j_errno;
1759 spin_unlock(&journal->j_state_lock);
1760 return err;
1761}
1762
1763/**
1764 * int journal_clear_err () - clears the journal's error state
1765 * @journal: journal to act on.
1766 *
1767 * An error must be cleared or Acked to take a FS out of readonly
1768 * mode.
1769 */
1770int journal_clear_err(journal_t *journal)
1771{
1772 int err = 0;
1773
1774 spin_lock(&journal->j_state_lock);
1775 if (journal->j_flags & JFS_ABORT)
1776 err = -EROFS;
1777 else
1778 journal->j_errno = 0;
1779 spin_unlock(&journal->j_state_lock);
1780 return err;
1781}
1782
1783/**
1784 * void journal_ack_err() - Ack journal err.
1785 * @journal: journal to act on.
1786 *
1787 * An error must be cleared or Acked to take a FS out of readonly
1788 * mode.
1789 */
1790void journal_ack_err(journal_t *journal)
1791{
1792 spin_lock(&journal->j_state_lock);
1793 if (journal->j_errno)
1794 journal->j_flags |= JFS_ACK_ERR;
1795 spin_unlock(&journal->j_state_lock);
1796}
1797
1798int journal_blocks_per_page(struct inode *inode)
1799{
1800 return 1 << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
1801}
1802
1803/*
1804 * Journal_head storage management
1805 */
1806static struct kmem_cache *journal_head_cache;
1807#ifdef CONFIG_JBD_DEBUG
1808static atomic_t nr_journal_heads = ATOMIC_INIT(0);
1809#endif
1810
1811static int journal_init_journal_head_cache(void)
1812{
1813 int retval;
1814
1815 J_ASSERT(journal_head_cache == NULL);
1816 journal_head_cache = kmem_cache_create("journal_head",
1817 sizeof(struct journal_head),
1818 0, /* offset */
1819 SLAB_TEMPORARY, /* flags */
1820 NULL); /* ctor */
1821 retval = 0;
1822 if (!journal_head_cache) {
1823 retval = -ENOMEM;
1824 printk(KERN_EMERG "JBD: no memory for journal_head cache\n");
1825 }
1826 return retval;
1827}
1828
1829static void journal_destroy_journal_head_cache(void)
1830{
1831 if (journal_head_cache) {
1832 kmem_cache_destroy(journal_head_cache);
1833 journal_head_cache = NULL;
1834 }
1835}
1836
1837/*
1838 * journal_head splicing and dicing
1839 */
1840static struct journal_head *journal_alloc_journal_head(void)
1841{
1842 struct journal_head *ret;
1843
1844#ifdef CONFIG_JBD_DEBUG
1845 atomic_inc(&nr_journal_heads);
1846#endif
1847 ret = kmem_cache_alloc(journal_head_cache, GFP_NOFS);
1848 if (ret == NULL) {
1849 jbd_debug(1, "out of memory for journal_head\n");
1850 printk_ratelimited(KERN_NOTICE "ENOMEM in %s, retrying.\n",
1851 __func__);
1852
1853 while (ret == NULL) {
1854 yield();
1855 ret = kmem_cache_alloc(journal_head_cache, GFP_NOFS);
1856 }
1857 }
1858 return ret;
1859}
1860
1861static void journal_free_journal_head(struct journal_head *jh)
1862{
1863#ifdef CONFIG_JBD_DEBUG
1864 atomic_dec(&nr_journal_heads);
1865 memset(jh, JBD_POISON_FREE, sizeof(*jh));
1866#endif
1867 kmem_cache_free(journal_head_cache, jh);
1868}
1869
1870/*
1871 * A journal_head is attached to a buffer_head whenever JBD has an
1872 * interest in the buffer.
1873 *
1874 * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit
1875 * is set. This bit is tested in core kernel code where we need to take
1876 * JBD-specific actions. Testing the zeroness of ->b_private is not reliable
1877 * there.
1878 *
1879 * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one.
1880 *
1881 * When a buffer has its BH_JBD bit set it is immune from being released by
1882 * core kernel code, mainly via ->b_count.
1883 *
1884 * A journal_head is detached from its buffer_head when the journal_head's
1885 * b_jcount reaches zero. Running transaction (b_transaction) and checkpoint
1886 * transaction (b_cp_transaction) hold their references to b_jcount.
1887 *
1888 * Various places in the kernel want to attach a journal_head to a buffer_head
1889 * _before_ attaching the journal_head to a transaction. To protect the
1890 * journal_head in this situation, journal_add_journal_head elevates the
1891 * journal_head's b_jcount refcount by one. The caller must call
1892 * journal_put_journal_head() to undo this.
1893 *
1894 * So the typical usage would be:
1895 *
1896 * (Attach a journal_head if needed. Increments b_jcount)
1897 * struct journal_head *jh = journal_add_journal_head(bh);
1898 * ...
1899 * (Get another reference for transaction)
1900 * journal_grab_journal_head(bh);
1901 * jh->b_transaction = xxx;
1902 * (Put original reference)
1903 * journal_put_journal_head(jh);
1904 */
1905
1906/*
1907 * Give a buffer_head a journal_head.
1908 *
1909 * May sleep.
1910 */
1911struct journal_head *journal_add_journal_head(struct buffer_head *bh)
1912{
1913 struct journal_head *jh;
1914 struct journal_head *new_jh = NULL;
1915
1916repeat:
1917 if (!buffer_jbd(bh)) {
1918 new_jh = journal_alloc_journal_head();
1919 memset(new_jh, 0, sizeof(*new_jh));
1920 }
1921
1922 jbd_lock_bh_journal_head(bh);
1923 if (buffer_jbd(bh)) {
1924 jh = bh2jh(bh);
1925 } else {
1926 J_ASSERT_BH(bh,
1927 (atomic_read(&bh->b_count) > 0) ||
1928 (bh->b_page && bh->b_page->mapping));
1929
1930 if (!new_jh) {
1931 jbd_unlock_bh_journal_head(bh);
1932 goto repeat;
1933 }
1934
1935 jh = new_jh;
1936 new_jh = NULL; /* We consumed it */
1937 set_buffer_jbd(bh);
1938 bh->b_private = jh;
1939 jh->b_bh = bh;
1940 get_bh(bh);
1941 BUFFER_TRACE(bh, "added journal_head");
1942 }
1943 jh->b_jcount++;
1944 jbd_unlock_bh_journal_head(bh);
1945 if (new_jh)
1946 journal_free_journal_head(new_jh);
1947 return bh->b_private;
1948}
1949
1950/*
1951 * Grab a ref against this buffer_head's journal_head. If it ended up not
1952 * having a journal_head, return NULL
1953 */
1954struct journal_head *journal_grab_journal_head(struct buffer_head *bh)
1955{
1956 struct journal_head *jh = NULL;
1957
1958 jbd_lock_bh_journal_head(bh);
1959 if (buffer_jbd(bh)) {
1960 jh = bh2jh(bh);
1961 jh->b_jcount++;
1962 }
1963 jbd_unlock_bh_journal_head(bh);
1964 return jh;
1965}
1966
1967static void __journal_remove_journal_head(struct buffer_head *bh)
1968{
1969 struct journal_head *jh = bh2jh(bh);
1970
1971 J_ASSERT_JH(jh, jh->b_jcount >= 0);
1972 J_ASSERT_JH(jh, jh->b_transaction == NULL);
1973 J_ASSERT_JH(jh, jh->b_next_transaction == NULL);
1974 J_ASSERT_JH(jh, jh->b_cp_transaction == NULL);
1975 J_ASSERT_JH(jh, jh->b_jlist == BJ_None);
1976 J_ASSERT_BH(bh, buffer_jbd(bh));
1977 J_ASSERT_BH(bh, jh2bh(jh) == bh);
1978 BUFFER_TRACE(bh, "remove journal_head");
1979 if (jh->b_frozen_data) {
1980 printk(KERN_WARNING "%s: freeing b_frozen_data\n", __func__);
1981 jbd_free(jh->b_frozen_data, bh->b_size);
1982 }
1983 if (jh->b_committed_data) {
1984 printk(KERN_WARNING "%s: freeing b_committed_data\n", __func__);
1985 jbd_free(jh->b_committed_data, bh->b_size);
1986 }
1987 bh->b_private = NULL;
1988 jh->b_bh = NULL; /* debug, really */
1989 clear_buffer_jbd(bh);
1990 journal_free_journal_head(jh);
1991}
1992
1993/*
1994 * Drop a reference on the passed journal_head. If it fell to zero then
1995 * release the journal_head from the buffer_head.
1996 */
1997void journal_put_journal_head(struct journal_head *jh)
1998{
1999 struct buffer_head *bh = jh2bh(jh);
2000
2001 jbd_lock_bh_journal_head(bh);
2002 J_ASSERT_JH(jh, jh->b_jcount > 0);
2003 --jh->b_jcount;
2004 if (!jh->b_jcount) {
2005 __journal_remove_journal_head(bh);
2006 jbd_unlock_bh_journal_head(bh);
2007 __brelse(bh);
2008 } else
2009 jbd_unlock_bh_journal_head(bh);
2010}
2011
2012/*
2013 * debugfs tunables
2014 */
2015#ifdef CONFIG_JBD_DEBUG
2016
2017u8 journal_enable_debug __read_mostly;
2018EXPORT_SYMBOL(journal_enable_debug);
2019
2020static struct dentry *jbd_debugfs_dir;
2021static struct dentry *jbd_debug;
2022
2023static void __init jbd_create_debugfs_entry(void)
2024{
2025 jbd_debugfs_dir = debugfs_create_dir("jbd", NULL);
2026 if (jbd_debugfs_dir)
2027 jbd_debug = debugfs_create_u8("jbd-debug", S_IRUGO | S_IWUSR,
2028 jbd_debugfs_dir,
2029 &journal_enable_debug);
2030}
2031
2032static void __exit jbd_remove_debugfs_entry(void)
2033{
2034 debugfs_remove(jbd_debug);
2035 debugfs_remove(jbd_debugfs_dir);
2036}
2037
2038#else
2039
2040static inline void jbd_create_debugfs_entry(void)
2041{
2042}
2043
2044static inline void jbd_remove_debugfs_entry(void)
2045{
2046}
2047
2048#endif
2049
2050struct kmem_cache *jbd_handle_cache;
2051
2052static int __init journal_init_handle_cache(void)
2053{
2054 jbd_handle_cache = kmem_cache_create("journal_handle",
2055 sizeof(handle_t),
2056 0, /* offset */
2057 SLAB_TEMPORARY, /* flags */
2058 NULL); /* ctor */
2059 if (jbd_handle_cache == NULL) {
2060 printk(KERN_EMERG "JBD: failed to create handle cache\n");
2061 return -ENOMEM;
2062 }
2063 return 0;
2064}
2065
2066static void journal_destroy_handle_cache(void)
2067{
2068 if (jbd_handle_cache)
2069 kmem_cache_destroy(jbd_handle_cache);
2070}
2071
2072/*
2073 * Module startup and shutdown
2074 */
2075
2076static int __init journal_init_caches(void)
2077{
2078 int ret;
2079
2080 ret = journal_init_revoke_caches();
2081 if (ret == 0)
2082 ret = journal_init_journal_head_cache();
2083 if (ret == 0)
2084 ret = journal_init_handle_cache();
2085 return ret;
2086}
2087
2088static void journal_destroy_caches(void)
2089{
2090 journal_destroy_revoke_caches();
2091 journal_destroy_journal_head_cache();
2092 journal_destroy_handle_cache();
2093}
2094
2095static int __init journal_init(void)
2096{
2097 int ret;
2098
2099 BUILD_BUG_ON(sizeof(struct journal_superblock_s) != 1024);
2100
2101 ret = journal_init_caches();
2102 if (ret != 0)
2103 journal_destroy_caches();
2104 jbd_create_debugfs_entry();
2105 return ret;
2106}
2107
2108static void __exit journal_exit(void)
2109{
2110#ifdef CONFIG_JBD_DEBUG
2111 int n = atomic_read(&nr_journal_heads);
2112 if (n)
2113 printk(KERN_EMERG "JBD: leaked %d journal_heads!\n", n);
2114#endif
2115 jbd_remove_debugfs_entry();
2116 journal_destroy_caches();
2117}
2118
2119MODULE_LICENSE("GPL");
2120module_init(journal_init);
2121module_exit(journal_exit);
2122