1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * linux/fs/jbd2/journal.c
4 *
5 * Written by Stephen C. Tweedie <sct@redhat.com>, 1998
6 *
7 * Copyright 1998 Red Hat corp --- All Rights Reserved
8 *
9 * Generic filesystem journal-writing code; part of the ext2fs
10 * journaling system.
11 *
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.
15 *
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).
20 */
21
22 #include <linux/module.h>
23 #include <linux/time.h>
24 #include <linux/fs.h>
25 #include <linux/jbd2.h>
26 #include <linux/errno.h>
27 #include <linux/slab.h>
28 #include <linux/init.h>
29 #include <linux/mm.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>
44
45 #define CREATE_TRACE_POINTS
46 #include <trace/events/jbd2.h>
47
48 #include <linux/uaccess.h>
49 #include <asm/page.h>
50
51 #ifdef CONFIG_JBD2_DEBUG
52 static ushort jbd2_journal_enable_debug __read_mostly;
53
54 module_param_named(jbd2_debug, jbd2_journal_enable_debug, ushort, 0644);
55 MODULE_PARM_DESC(jbd2_debug, "Debugging level for jbd2");
56 #endif
57
58 EXPORT_SYMBOL(jbd2_journal_extend);
59 EXPORT_SYMBOL(jbd2_journal_stop);
60 EXPORT_SYMBOL(jbd2_journal_lock_updates);
61 EXPORT_SYMBOL(jbd2_journal_unlock_updates);
62 EXPORT_SYMBOL(jbd2_journal_get_write_access);
63 EXPORT_SYMBOL(jbd2_journal_get_create_access);
64 EXPORT_SYMBOL(jbd2_journal_get_undo_access);
65 EXPORT_SYMBOL(jbd2_journal_set_triggers);
66 EXPORT_SYMBOL(jbd2_journal_dirty_metadata);
67 EXPORT_SYMBOL(jbd2_journal_forget);
68 EXPORT_SYMBOL(jbd2_journal_flush);
69 EXPORT_SYMBOL(jbd2_journal_revoke);
70
71 EXPORT_SYMBOL(jbd2_journal_init_dev);
72 EXPORT_SYMBOL(jbd2_journal_init_inode);
73 EXPORT_SYMBOL(jbd2_journal_check_used_features);
74 EXPORT_SYMBOL(jbd2_journal_check_available_features);
75 EXPORT_SYMBOL(jbd2_journal_set_features);
76 EXPORT_SYMBOL(jbd2_journal_load);
77 EXPORT_SYMBOL(jbd2_journal_destroy);
78 EXPORT_SYMBOL(jbd2_journal_abort);
79 EXPORT_SYMBOL(jbd2_journal_errno);
80 EXPORT_SYMBOL(jbd2_journal_ack_err);
81 EXPORT_SYMBOL(jbd2_journal_clear_err);
82 EXPORT_SYMBOL(jbd2_log_wait_commit);
83 EXPORT_SYMBOL(jbd2_journal_start_commit);
84 EXPORT_SYMBOL(jbd2_journal_force_commit_nested);
85 EXPORT_SYMBOL(jbd2_journal_wipe);
86 EXPORT_SYMBOL(jbd2_journal_blocks_per_page);
87 EXPORT_SYMBOL(jbd2_journal_invalidate_folio);
88 EXPORT_SYMBOL(jbd2_journal_try_to_free_buffers);
89 EXPORT_SYMBOL(jbd2_journal_force_commit);
90 EXPORT_SYMBOL(jbd2_journal_inode_ranged_write);
91 EXPORT_SYMBOL(jbd2_journal_inode_ranged_wait);
92 EXPORT_SYMBOL(jbd2_journal_finish_inode_data_buffers);
93 EXPORT_SYMBOL(jbd2_journal_init_jbd_inode);
94 EXPORT_SYMBOL(jbd2_journal_release_jbd_inode);
95 EXPORT_SYMBOL(jbd2_journal_begin_ordered_truncate);
96 EXPORT_SYMBOL(jbd2_inode_cache);
97
98 static int jbd2_journal_create_slab(size_t slab_size);
99
100 #ifdef CONFIG_JBD2_DEBUG
__jbd2_debug(int level,const char * file,const char * func,unsigned int line,const char * fmt,...)101 void __jbd2_debug(int level, const char *file, const char *func,
102 unsigned int line, const char *fmt, ...)
103 {
104 struct va_format vaf;
105 va_list args;
106
107 if (level > jbd2_journal_enable_debug)
108 return;
109 va_start(args, fmt);
110 vaf.fmt = fmt;
111 vaf.va = &args;
112 printk(KERN_DEBUG "%s: (%s, %u): %pV", file, func, line, &vaf);
113 va_end(args);
114 }
115 #endif
116
117 /* Checksumming functions */
jbd2_superblock_csum(journal_t * j,journal_superblock_t * sb)118 static __be32 jbd2_superblock_csum(journal_t *j, journal_superblock_t *sb)
119 {
120 __u32 csum;
121 __be32 old_csum;
122
123 old_csum = sb->s_checksum;
124 sb->s_checksum = 0;
125 csum = jbd2_chksum(j, ~0, (char *)sb, sizeof(journal_superblock_t));
126 sb->s_checksum = old_csum;
127
128 return cpu_to_be32(csum);
129 }
130
131 /*
132 * Helper function used to manage commit timeouts
133 */
134
commit_timeout(struct timer_list * t)135 static void commit_timeout(struct timer_list *t)
136 {
137 journal_t *journal = from_timer(journal, t, j_commit_timer);
138
139 wake_up_process(journal->j_task);
140 }
141
142 /*
143 * kjournald2: The main thread function used to manage a logging device
144 * journal.
145 *
146 * This kernel thread is responsible for two things:
147 *
148 * 1) COMMIT: Every so often we need to commit the current state of the
149 * filesystem to disk. The journal thread is responsible for writing
150 * all of the metadata buffers to disk. If a fast commit is ongoing
151 * journal thread waits until it's done and then continues from
152 * there on.
153 *
154 * 2) CHECKPOINT: We cannot reuse a used section of the log file until all
155 * of the data in that part of the log has been rewritten elsewhere on
156 * the disk. Flushing these old buffers to reclaim space in the log is
157 * known as checkpointing, and this thread is responsible for that job.
158 */
159
kjournald2(void * arg)160 static int kjournald2(void *arg)
161 {
162 journal_t *journal = arg;
163 transaction_t *transaction;
164
165 /*
166 * Set up an interval timer which can be used to trigger a commit wakeup
167 * after the commit interval expires
168 */
169 timer_setup(&journal->j_commit_timer, commit_timeout, 0);
170
171 set_freezable();
172
173 /* Record that the journal thread is running */
174 journal->j_task = current;
175 wake_up(&journal->j_wait_done_commit);
176
177 /*
178 * Make sure that no allocations from this kernel thread will ever
179 * recurse to the fs layer because we are responsible for the
180 * transaction commit and any fs involvement might get stuck waiting for
181 * the trasn. commit.
182 */
183 memalloc_nofs_save();
184
185 /*
186 * And now, wait forever for commit wakeup events.
187 */
188 write_lock(&journal->j_state_lock);
189
190 loop:
191 if (journal->j_flags & JBD2_UNMOUNT)
192 goto end_loop;
193
194 jbd2_debug(1, "commit_sequence=%u, commit_request=%u\n",
195 journal->j_commit_sequence, journal->j_commit_request);
196
197 if (journal->j_commit_sequence != journal->j_commit_request) {
198 jbd2_debug(1, "OK, requests differ\n");
199 write_unlock(&journal->j_state_lock);
200 del_timer_sync(&journal->j_commit_timer);
201 jbd2_journal_commit_transaction(journal);
202 write_lock(&journal->j_state_lock);
203 goto loop;
204 }
205
206 wake_up(&journal->j_wait_done_commit);
207 if (freezing(current)) {
208 /*
209 * The simpler the better. Flushing journal isn't a
210 * good idea, because that depends on threads that may
211 * be already stopped.
212 */
213 jbd2_debug(1, "Now suspending kjournald2\n");
214 write_unlock(&journal->j_state_lock);
215 try_to_freeze();
216 write_lock(&journal->j_state_lock);
217 } else {
218 /*
219 * We assume on resume that commits are already there,
220 * so we don't sleep
221 */
222 DEFINE_WAIT(wait);
223 int should_sleep = 1;
224
225 prepare_to_wait(&journal->j_wait_commit, &wait,
226 TASK_INTERRUPTIBLE);
227 if (journal->j_commit_sequence != journal->j_commit_request)
228 should_sleep = 0;
229 transaction = journal->j_running_transaction;
230 if (transaction && time_after_eq(jiffies,
231 transaction->t_expires))
232 should_sleep = 0;
233 if (journal->j_flags & JBD2_UNMOUNT)
234 should_sleep = 0;
235 if (should_sleep) {
236 write_unlock(&journal->j_state_lock);
237 schedule();
238 write_lock(&journal->j_state_lock);
239 }
240 finish_wait(&journal->j_wait_commit, &wait);
241 }
242
243 jbd2_debug(1, "kjournald2 wakes\n");
244
245 /*
246 * Were we woken up by a commit wakeup event?
247 */
248 transaction = journal->j_running_transaction;
249 if (transaction && time_after_eq(jiffies, transaction->t_expires)) {
250 journal->j_commit_request = transaction->t_tid;
251 jbd2_debug(1, "woke because of timeout\n");
252 }
253 goto loop;
254
255 end_loop:
256 del_timer_sync(&journal->j_commit_timer);
257 journal->j_task = NULL;
258 wake_up(&journal->j_wait_done_commit);
259 jbd2_debug(1, "Journal thread exiting.\n");
260 write_unlock(&journal->j_state_lock);
261 return 0;
262 }
263
jbd2_journal_start_thread(journal_t * journal)264 static int jbd2_journal_start_thread(journal_t *journal)
265 {
266 struct task_struct *t;
267
268 t = kthread_run(kjournald2, journal, "jbd2/%s",
269 journal->j_devname);
270 if (IS_ERR(t))
271 return PTR_ERR(t);
272
273 wait_event(journal->j_wait_done_commit, journal->j_task != NULL);
274 return 0;
275 }
276
journal_kill_thread(journal_t * journal)277 static void journal_kill_thread(journal_t *journal)
278 {
279 write_lock(&journal->j_state_lock);
280 journal->j_flags |= JBD2_UNMOUNT;
281
282 while (journal->j_task) {
283 write_unlock(&journal->j_state_lock);
284 wake_up(&journal->j_wait_commit);
285 wait_event(journal->j_wait_done_commit, journal->j_task == NULL);
286 write_lock(&journal->j_state_lock);
287 }
288 write_unlock(&journal->j_state_lock);
289 }
290
291 /*
292 * jbd2_journal_write_metadata_buffer: write a metadata buffer to the journal.
293 *
294 * Writes a metadata buffer to a given disk block. The actual IO is not
295 * performed but a new buffer_head is constructed which labels the data
296 * to be written with the correct destination disk block.
297 *
298 * Any magic-number escaping which needs to be done will cause a
299 * copy-out here. If the buffer happens to start with the
300 * JBD2_MAGIC_NUMBER, then we can't write it to the log directly: the
301 * magic number is only written to the log for descripter blocks. In
302 * this case, we copy the data and replace the first word with 0, and we
303 * return a result code which indicates that this buffer needs to be
304 * marked as an escaped buffer in the corresponding log descriptor
305 * block. The missing word can then be restored when the block is read
306 * during recovery.
307 *
308 * If the source buffer has already been modified by a new transaction
309 * since we took the last commit snapshot, we use the frozen copy of
310 * that data for IO. If we end up using the existing buffer_head's data
311 * for the write, then we have to make sure nobody modifies it while the
312 * IO is in progress. do_get_write_access() handles this.
313 *
314 * The function returns a pointer to the buffer_head to be used for IO.
315 *
316 *
317 * Return value:
318 * <0: Error
319 * >=0: Finished OK
320 *
321 * On success:
322 * Bit 0 set == escape performed on the data
323 * Bit 1 set == buffer copy-out performed (kfree the data after IO)
324 */
325
jbd2_journal_write_metadata_buffer(transaction_t * transaction,struct journal_head * jh_in,struct buffer_head ** bh_out,sector_t blocknr)326 int jbd2_journal_write_metadata_buffer(transaction_t *transaction,
327 struct journal_head *jh_in,
328 struct buffer_head **bh_out,
329 sector_t blocknr)
330 {
331 int need_copy_out = 0;
332 int done_copy_out = 0;
333 int do_escape = 0;
334 char *mapped_data;
335 struct buffer_head *new_bh;
336 struct folio *new_folio;
337 unsigned int new_offset;
338 struct buffer_head *bh_in = jh2bh(jh_in);
339 journal_t *journal = transaction->t_journal;
340
341 /*
342 * The buffer really shouldn't be locked: only the current committing
343 * transaction is allowed to write it, so nobody else is allowed
344 * to do any IO.
345 *
346 * akpm: except if we're journalling data, and write() output is
347 * also part of a shared mapping, and another thread has
348 * decided to launch a writepage() against this buffer.
349 */
350 J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in));
351
352 new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL);
353
354 /* keep subsequent assertions sane */
355 atomic_set(&new_bh->b_count, 1);
356
357 spin_lock(&jh_in->b_state_lock);
358 repeat:
359 /*
360 * If a new transaction has already done a buffer copy-out, then
361 * we use that version of the data for the commit.
362 */
363 if (jh_in->b_frozen_data) {
364 done_copy_out = 1;
365 new_folio = virt_to_folio(jh_in->b_frozen_data);
366 new_offset = offset_in_folio(new_folio, jh_in->b_frozen_data);
367 } else {
368 new_folio = jh2bh(jh_in)->b_folio;
369 new_offset = offset_in_folio(new_folio, jh2bh(jh_in)->b_data);
370 }
371
372 mapped_data = kmap_local_folio(new_folio, new_offset);
373 /*
374 * Fire data frozen trigger if data already wasn't frozen. Do this
375 * before checking for escaping, as the trigger may modify the magic
376 * offset. If a copy-out happens afterwards, it will have the correct
377 * data in the buffer.
378 */
379 if (!done_copy_out)
380 jbd2_buffer_frozen_trigger(jh_in, mapped_data,
381 jh_in->b_triggers);
382
383 /*
384 * Check for escaping
385 */
386 if (*((__be32 *)mapped_data) == cpu_to_be32(JBD2_MAGIC_NUMBER)) {
387 need_copy_out = 1;
388 do_escape = 1;
389 }
390 kunmap_local(mapped_data);
391
392 /*
393 * Do we need to do a data copy?
394 */
395 if (need_copy_out && !done_copy_out) {
396 char *tmp;
397
398 spin_unlock(&jh_in->b_state_lock);
399 tmp = jbd2_alloc(bh_in->b_size, GFP_NOFS);
400 if (!tmp) {
401 brelse(new_bh);
402 return -ENOMEM;
403 }
404 spin_lock(&jh_in->b_state_lock);
405 if (jh_in->b_frozen_data) {
406 jbd2_free(tmp, bh_in->b_size);
407 goto repeat;
408 }
409
410 jh_in->b_frozen_data = tmp;
411 memcpy_from_folio(tmp, new_folio, new_offset, bh_in->b_size);
412
413 new_folio = virt_to_folio(tmp);
414 new_offset = offset_in_folio(new_folio, tmp);
415 done_copy_out = 1;
416
417 /*
418 * This isn't strictly necessary, as we're using frozen
419 * data for the escaping, but it keeps consistency with
420 * b_frozen_data usage.
421 */
422 jh_in->b_frozen_triggers = jh_in->b_triggers;
423 }
424
425 /*
426 * Did we need to do an escaping? Now we've done all the
427 * copying, we can finally do so.
428 */
429 if (do_escape) {
430 mapped_data = kmap_local_folio(new_folio, new_offset);
431 *((unsigned int *)mapped_data) = 0;
432 kunmap_local(mapped_data);
433 }
434
435 folio_set_bh(new_bh, new_folio, new_offset);
436 new_bh->b_size = bh_in->b_size;
437 new_bh->b_bdev = journal->j_dev;
438 new_bh->b_blocknr = blocknr;
439 new_bh->b_private = bh_in;
440 set_buffer_mapped(new_bh);
441 set_buffer_dirty(new_bh);
442
443 *bh_out = new_bh;
444
445 /*
446 * The to-be-written buffer needs to get moved to the io queue,
447 * and the original buffer whose contents we are shadowing or
448 * copying is moved to the transaction's shadow queue.
449 */
450 JBUFFER_TRACE(jh_in, "file as BJ_Shadow");
451 spin_lock(&journal->j_list_lock);
452 __jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow);
453 spin_unlock(&journal->j_list_lock);
454 set_buffer_shadow(bh_in);
455 spin_unlock(&jh_in->b_state_lock);
456
457 return do_escape | (done_copy_out << 1);
458 }
459
460 /*
461 * Allocation code for the journal file. Manage the space left in the
462 * journal, so that we can begin checkpointing when appropriate.
463 */
464
465 /*
466 * Called with j_state_lock locked for writing.
467 * Returns true if a transaction commit was started.
468 */
__jbd2_log_start_commit(journal_t * journal,tid_t target)469 static int __jbd2_log_start_commit(journal_t *journal, tid_t target)
470 {
471 /* Return if the txn has already requested to be committed */
472 if (journal->j_commit_request == target)
473 return 0;
474
475 /*
476 * The only transaction we can possibly wait upon is the
477 * currently running transaction (if it exists). Otherwise,
478 * the target tid must be an old one.
479 */
480 if (journal->j_running_transaction &&
481 journal->j_running_transaction->t_tid == target) {
482 /*
483 * We want a new commit: OK, mark the request and wakeup the
484 * commit thread. We do _not_ do the commit ourselves.
485 */
486
487 journal->j_commit_request = target;
488 jbd2_debug(1, "JBD2: requesting commit %u/%u\n",
489 journal->j_commit_request,
490 journal->j_commit_sequence);
491 journal->j_running_transaction->t_requested = jiffies;
492 wake_up(&journal->j_wait_commit);
493 return 1;
494 } else if (!tid_geq(journal->j_commit_request, target))
495 /* This should never happen, but if it does, preserve
496 the evidence before kjournald goes into a loop and
497 increments j_commit_sequence beyond all recognition. */
498 WARN_ONCE(1, "JBD2: bad log_start_commit: %u %u %u %u\n",
499 journal->j_commit_request,
500 journal->j_commit_sequence,
501 target, journal->j_running_transaction ?
502 journal->j_running_transaction->t_tid : 0);
503 return 0;
504 }
505
jbd2_log_start_commit(journal_t * journal,tid_t tid)506 int jbd2_log_start_commit(journal_t *journal, tid_t tid)
507 {
508 int ret;
509
510 write_lock(&journal->j_state_lock);
511 ret = __jbd2_log_start_commit(journal, tid);
512 write_unlock(&journal->j_state_lock);
513 return ret;
514 }
515
516 /*
517 * Force and wait any uncommitted transactions. We can only force the running
518 * transaction if we don't have an active handle, otherwise, we will deadlock.
519 * Returns: <0 in case of error,
520 * 0 if nothing to commit,
521 * 1 if transaction was successfully committed.
522 */
__jbd2_journal_force_commit(journal_t * journal)523 static int __jbd2_journal_force_commit(journal_t *journal)
524 {
525 transaction_t *transaction = NULL;
526 tid_t tid;
527 int need_to_start = 0, ret = 0;
528
529 read_lock(&journal->j_state_lock);
530 if (journal->j_running_transaction && !current->journal_info) {
531 transaction = journal->j_running_transaction;
532 if (!tid_geq(journal->j_commit_request, transaction->t_tid))
533 need_to_start = 1;
534 } else if (journal->j_committing_transaction)
535 transaction = journal->j_committing_transaction;
536
537 if (!transaction) {
538 /* Nothing to commit */
539 read_unlock(&journal->j_state_lock);
540 return 0;
541 }
542 tid = transaction->t_tid;
543 read_unlock(&journal->j_state_lock);
544 if (need_to_start)
545 jbd2_log_start_commit(journal, tid);
546 ret = jbd2_log_wait_commit(journal, tid);
547 if (!ret)
548 ret = 1;
549
550 return ret;
551 }
552
553 /**
554 * jbd2_journal_force_commit_nested - Force and wait upon a commit if the
555 * calling process is not within transaction.
556 *
557 * @journal: journal to force
558 * Returns true if progress was made.
559 *
560 * This is used for forcing out undo-protected data which contains
561 * bitmaps, when the fs is running out of space.
562 */
jbd2_journal_force_commit_nested(journal_t * journal)563 int jbd2_journal_force_commit_nested(journal_t *journal)
564 {
565 int ret;
566
567 ret = __jbd2_journal_force_commit(journal);
568 return ret > 0;
569 }
570
571 /**
572 * jbd2_journal_force_commit() - force any uncommitted transactions
573 * @journal: journal to force
574 *
575 * Caller want unconditional commit. We can only force the running transaction
576 * if we don't have an active handle, otherwise, we will deadlock.
577 */
jbd2_journal_force_commit(journal_t * journal)578 int jbd2_journal_force_commit(journal_t *journal)
579 {
580 int ret;
581
582 J_ASSERT(!current->journal_info);
583 ret = __jbd2_journal_force_commit(journal);
584 if (ret > 0)
585 ret = 0;
586 return ret;
587 }
588
589 /*
590 * Start a commit of the current running transaction (if any). Returns true
591 * if a transaction is going to be committed (or is currently already
592 * committing), and fills its tid in at *ptid
593 */
jbd2_journal_start_commit(journal_t * journal,tid_t * ptid)594 int jbd2_journal_start_commit(journal_t *journal, tid_t *ptid)
595 {
596 int ret = 0;
597
598 write_lock(&journal->j_state_lock);
599 if (journal->j_running_transaction) {
600 tid_t tid = journal->j_running_transaction->t_tid;
601
602 __jbd2_log_start_commit(journal, tid);
603 /* There's a running transaction and we've just made sure
604 * it's commit has been scheduled. */
605 if (ptid)
606 *ptid = tid;
607 ret = 1;
608 } else if (journal->j_committing_transaction) {
609 /*
610 * If commit has been started, then we have to wait for
611 * completion of that transaction.
612 */
613 if (ptid)
614 *ptid = journal->j_committing_transaction->t_tid;
615 ret = 1;
616 }
617 write_unlock(&journal->j_state_lock);
618 return ret;
619 }
620
621 /*
622 * Return 1 if a given transaction has not yet sent barrier request
623 * connected with a transaction commit. If 0 is returned, transaction
624 * may or may not have sent the barrier. Used to avoid sending barrier
625 * twice in common cases.
626 */
jbd2_trans_will_send_data_barrier(journal_t * journal,tid_t tid)627 int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid)
628 {
629 int ret = 0;
630 transaction_t *commit_trans;
631
632 if (!(journal->j_flags & JBD2_BARRIER))
633 return 0;
634 read_lock(&journal->j_state_lock);
635 /* Transaction already committed? */
636 if (tid_geq(journal->j_commit_sequence, tid))
637 goto out;
638 commit_trans = journal->j_committing_transaction;
639 if (!commit_trans || commit_trans->t_tid != tid) {
640 ret = 1;
641 goto out;
642 }
643 /*
644 * Transaction is being committed and we already proceeded to
645 * submitting a flush to fs partition?
646 */
647 if (journal->j_fs_dev != journal->j_dev) {
648 if (!commit_trans->t_need_data_flush ||
649 commit_trans->t_state >= T_COMMIT_DFLUSH)
650 goto out;
651 } else {
652 if (commit_trans->t_state >= T_COMMIT_JFLUSH)
653 goto out;
654 }
655 ret = 1;
656 out:
657 read_unlock(&journal->j_state_lock);
658 return ret;
659 }
660 EXPORT_SYMBOL(jbd2_trans_will_send_data_barrier);
661
662 /*
663 * Wait for a specified commit to complete.
664 * The caller may not hold the journal lock.
665 */
jbd2_log_wait_commit(journal_t * journal,tid_t tid)666 int jbd2_log_wait_commit(journal_t *journal, tid_t tid)
667 {
668 int err = 0;
669
670 read_lock(&journal->j_state_lock);
671 #ifdef CONFIG_PROVE_LOCKING
672 /*
673 * Some callers make sure transaction is already committing and in that
674 * case we cannot block on open handles anymore. So don't warn in that
675 * case.
676 */
677 if (tid_gt(tid, journal->j_commit_sequence) &&
678 (!journal->j_committing_transaction ||
679 journal->j_committing_transaction->t_tid != tid)) {
680 read_unlock(&journal->j_state_lock);
681 jbd2_might_wait_for_commit(journal);
682 read_lock(&journal->j_state_lock);
683 }
684 #endif
685 #ifdef CONFIG_JBD2_DEBUG
686 if (!tid_geq(journal->j_commit_request, tid)) {
687 printk(KERN_ERR
688 "%s: error: j_commit_request=%u, tid=%u\n",
689 __func__, journal->j_commit_request, tid);
690 }
691 #endif
692 while (tid_gt(tid, journal->j_commit_sequence)) {
693 jbd2_debug(1, "JBD2: want %u, j_commit_sequence=%u\n",
694 tid, journal->j_commit_sequence);
695 read_unlock(&journal->j_state_lock);
696 wake_up(&journal->j_wait_commit);
697 wait_event(journal->j_wait_done_commit,
698 !tid_gt(tid, journal->j_commit_sequence));
699 read_lock(&journal->j_state_lock);
700 }
701 read_unlock(&journal->j_state_lock);
702
703 if (unlikely(is_journal_aborted(journal)))
704 err = -EIO;
705 return err;
706 }
707
708 /*
709 * Start a fast commit. If there's an ongoing fast or full commit wait for
710 * it to complete. Returns 0 if a new fast commit was started. Returns -EALREADY
711 * if a fast commit is not needed, either because there's an already a commit
712 * going on or this tid has already been committed. Returns -EINVAL if no jbd2
713 * commit has yet been performed.
714 */
jbd2_fc_begin_commit(journal_t * journal,tid_t tid)715 int jbd2_fc_begin_commit(journal_t *journal, tid_t tid)
716 {
717 if (unlikely(is_journal_aborted(journal)))
718 return -EIO;
719 /*
720 * Fast commits only allowed if at least one full commit has
721 * been processed.
722 */
723 if (!journal->j_stats.ts_tid)
724 return -EINVAL;
725
726 write_lock(&journal->j_state_lock);
727 if (tid <= journal->j_commit_sequence) {
728 write_unlock(&journal->j_state_lock);
729 return -EALREADY;
730 }
731
732 if (journal->j_flags & JBD2_FULL_COMMIT_ONGOING ||
733 (journal->j_flags & JBD2_FAST_COMMIT_ONGOING)) {
734 DEFINE_WAIT(wait);
735
736 prepare_to_wait(&journal->j_fc_wait, &wait,
737 TASK_UNINTERRUPTIBLE);
738 write_unlock(&journal->j_state_lock);
739 schedule();
740 finish_wait(&journal->j_fc_wait, &wait);
741 return -EALREADY;
742 }
743 journal->j_flags |= JBD2_FAST_COMMIT_ONGOING;
744 write_unlock(&journal->j_state_lock);
745 jbd2_journal_lock_updates(journal);
746
747 return 0;
748 }
749 EXPORT_SYMBOL(jbd2_fc_begin_commit);
750
751 /*
752 * Stop a fast commit. If fallback is set, this function starts commit of
753 * TID tid before any other fast commit can start.
754 */
__jbd2_fc_end_commit(journal_t * journal,tid_t tid,bool fallback)755 static int __jbd2_fc_end_commit(journal_t *journal, tid_t tid, bool fallback)
756 {
757 jbd2_journal_unlock_updates(journal);
758 if (journal->j_fc_cleanup_callback)
759 journal->j_fc_cleanup_callback(journal, 0, tid);
760 write_lock(&journal->j_state_lock);
761 journal->j_flags &= ~JBD2_FAST_COMMIT_ONGOING;
762 if (fallback)
763 journal->j_flags |= JBD2_FULL_COMMIT_ONGOING;
764 write_unlock(&journal->j_state_lock);
765 wake_up(&journal->j_fc_wait);
766 if (fallback)
767 return jbd2_complete_transaction(journal, tid);
768 return 0;
769 }
770
jbd2_fc_end_commit(journal_t * journal)771 int jbd2_fc_end_commit(journal_t *journal)
772 {
773 return __jbd2_fc_end_commit(journal, 0, false);
774 }
775 EXPORT_SYMBOL(jbd2_fc_end_commit);
776
jbd2_fc_end_commit_fallback(journal_t * journal)777 int jbd2_fc_end_commit_fallback(journal_t *journal)
778 {
779 tid_t tid;
780
781 read_lock(&journal->j_state_lock);
782 tid = journal->j_running_transaction ?
783 journal->j_running_transaction->t_tid : 0;
784 read_unlock(&journal->j_state_lock);
785 return __jbd2_fc_end_commit(journal, tid, true);
786 }
787 EXPORT_SYMBOL(jbd2_fc_end_commit_fallback);
788
789 /* Return 1 when transaction with given tid has already committed. */
jbd2_transaction_committed(journal_t * journal,tid_t tid)790 int jbd2_transaction_committed(journal_t *journal, tid_t tid)
791 {
792 int ret = 1;
793
794 read_lock(&journal->j_state_lock);
795 if (journal->j_running_transaction &&
796 journal->j_running_transaction->t_tid == tid)
797 ret = 0;
798 if (journal->j_committing_transaction &&
799 journal->j_committing_transaction->t_tid == tid)
800 ret = 0;
801 read_unlock(&journal->j_state_lock);
802 return ret;
803 }
804 EXPORT_SYMBOL(jbd2_transaction_committed);
805
806 /*
807 * When this function returns the transaction corresponding to tid
808 * will be completed. If the transaction has currently running, start
809 * committing that transaction before waiting for it to complete. If
810 * the transaction id is stale, it is by definition already completed,
811 * so just return SUCCESS.
812 */
jbd2_complete_transaction(journal_t * journal,tid_t tid)813 int jbd2_complete_transaction(journal_t *journal, tid_t tid)
814 {
815 int need_to_wait = 1;
816
817 read_lock(&journal->j_state_lock);
818 if (journal->j_running_transaction &&
819 journal->j_running_transaction->t_tid == tid) {
820 if (journal->j_commit_request != tid) {
821 /* transaction not yet started, so request it */
822 read_unlock(&journal->j_state_lock);
823 jbd2_log_start_commit(journal, tid);
824 goto wait_commit;
825 }
826 } else if (!(journal->j_committing_transaction &&
827 journal->j_committing_transaction->t_tid == tid))
828 need_to_wait = 0;
829 read_unlock(&journal->j_state_lock);
830 if (!need_to_wait)
831 return 0;
832 wait_commit:
833 return jbd2_log_wait_commit(journal, tid);
834 }
835 EXPORT_SYMBOL(jbd2_complete_transaction);
836
837 /*
838 * Log buffer allocation routines:
839 */
840
jbd2_journal_next_log_block(journal_t * journal,unsigned long long * retp)841 int jbd2_journal_next_log_block(journal_t *journal, unsigned long long *retp)
842 {
843 unsigned long blocknr;
844
845 write_lock(&journal->j_state_lock);
846 J_ASSERT(journal->j_free > 1);
847
848 blocknr = journal->j_head;
849 journal->j_head++;
850 journal->j_free--;
851 if (journal->j_head == journal->j_last)
852 journal->j_head = journal->j_first;
853 write_unlock(&journal->j_state_lock);
854 return jbd2_journal_bmap(journal, blocknr, retp);
855 }
856
857 /* Map one fast commit buffer for use by the file system */
jbd2_fc_get_buf(journal_t * journal,struct buffer_head ** bh_out)858 int jbd2_fc_get_buf(journal_t *journal, struct buffer_head **bh_out)
859 {
860 unsigned long long pblock;
861 unsigned long blocknr;
862 int ret = 0;
863 struct buffer_head *bh;
864 int fc_off;
865
866 *bh_out = NULL;
867
868 if (journal->j_fc_off + journal->j_fc_first < journal->j_fc_last) {
869 fc_off = journal->j_fc_off;
870 blocknr = journal->j_fc_first + fc_off;
871 journal->j_fc_off++;
872 } else {
873 ret = -EINVAL;
874 }
875
876 if (ret)
877 return ret;
878
879 ret = jbd2_journal_bmap(journal, blocknr, &pblock);
880 if (ret)
881 return ret;
882
883 bh = __getblk(journal->j_dev, pblock, journal->j_blocksize);
884 if (!bh)
885 return -ENOMEM;
886
887
888 journal->j_fc_wbuf[fc_off] = bh;
889
890 *bh_out = bh;
891
892 return 0;
893 }
894 EXPORT_SYMBOL(jbd2_fc_get_buf);
895
896 /*
897 * Wait on fast commit buffers that were allocated by jbd2_fc_get_buf
898 * for completion.
899 */
jbd2_fc_wait_bufs(journal_t * journal,int num_blks)900 int jbd2_fc_wait_bufs(journal_t *journal, int num_blks)
901 {
902 struct buffer_head *bh;
903 int i, j_fc_off;
904
905 j_fc_off = journal->j_fc_off;
906
907 /*
908 * Wait in reverse order to minimize chances of us being woken up before
909 * all IOs have completed
910 */
911 for (i = j_fc_off - 1; i >= j_fc_off - num_blks; i--) {
912 bh = journal->j_fc_wbuf[i];
913 wait_on_buffer(bh);
914 /*
915 * Update j_fc_off so jbd2_fc_release_bufs can release remain
916 * buffer head.
917 */
918 if (unlikely(!buffer_uptodate(bh))) {
919 journal->j_fc_off = i + 1;
920 return -EIO;
921 }
922 put_bh(bh);
923 journal->j_fc_wbuf[i] = NULL;
924 }
925
926 return 0;
927 }
928 EXPORT_SYMBOL(jbd2_fc_wait_bufs);
929
jbd2_fc_release_bufs(journal_t * journal)930 int jbd2_fc_release_bufs(journal_t *journal)
931 {
932 struct buffer_head *bh;
933 int i, j_fc_off;
934
935 j_fc_off = journal->j_fc_off;
936
937 for (i = j_fc_off - 1; i >= 0; i--) {
938 bh = journal->j_fc_wbuf[i];
939 if (!bh)
940 break;
941 put_bh(bh);
942 journal->j_fc_wbuf[i] = NULL;
943 }
944
945 return 0;
946 }
947 EXPORT_SYMBOL(jbd2_fc_release_bufs);
948
949 /*
950 * Conversion of logical to physical block numbers for the journal
951 *
952 * On external journals the journal blocks are identity-mapped, so
953 * this is a no-op. If needed, we can use j_blk_offset - everything is
954 * ready.
955 */
jbd2_journal_bmap(journal_t * journal,unsigned long blocknr,unsigned long long * retp)956 int jbd2_journal_bmap(journal_t *journal, unsigned long blocknr,
957 unsigned long long *retp)
958 {
959 int err = 0;
960 unsigned long long ret;
961 sector_t block = blocknr;
962
963 if (journal->j_bmap) {
964 err = journal->j_bmap(journal, &block);
965 if (err == 0)
966 *retp = block;
967 } else if (journal->j_inode) {
968 ret = bmap(journal->j_inode, &block);
969
970 if (ret || !block) {
971 printk(KERN_ALERT "%s: journal block not found "
972 "at offset %lu on %s\n",
973 __func__, blocknr, journal->j_devname);
974 err = -EIO;
975 jbd2_journal_abort(journal, err);
976 } else {
977 *retp = block;
978 }
979
980 } else {
981 *retp = blocknr; /* +journal->j_blk_offset */
982 }
983 return err;
984 }
985
986 /*
987 * We play buffer_head aliasing tricks to write data/metadata blocks to
988 * the journal without copying their contents, but for journal
989 * descriptor blocks we do need to generate bona fide buffers.
990 *
991 * After the caller of jbd2_journal_get_descriptor_buffer() has finished modifying
992 * the buffer's contents they really should run flush_dcache_page(bh->b_page).
993 * But we don't bother doing that, so there will be coherency problems with
994 * mmaps of blockdevs which hold live JBD-controlled filesystems.
995 */
996 struct buffer_head *
jbd2_journal_get_descriptor_buffer(transaction_t * transaction,int type)997 jbd2_journal_get_descriptor_buffer(transaction_t *transaction, int type)
998 {
999 journal_t *journal = transaction->t_journal;
1000 struct buffer_head *bh;
1001 unsigned long long blocknr;
1002 journal_header_t *header;
1003 int err;
1004
1005 err = jbd2_journal_next_log_block(journal, &blocknr);
1006
1007 if (err)
1008 return NULL;
1009
1010 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
1011 if (!bh)
1012 return NULL;
1013 atomic_dec(&transaction->t_outstanding_credits);
1014 lock_buffer(bh);
1015 memset(bh->b_data, 0, journal->j_blocksize);
1016 header = (journal_header_t *)bh->b_data;
1017 header->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER);
1018 header->h_blocktype = cpu_to_be32(type);
1019 header->h_sequence = cpu_to_be32(transaction->t_tid);
1020 set_buffer_uptodate(bh);
1021 unlock_buffer(bh);
1022 BUFFER_TRACE(bh, "return this buffer");
1023 return bh;
1024 }
1025
jbd2_descriptor_block_csum_set(journal_t * j,struct buffer_head * bh)1026 void jbd2_descriptor_block_csum_set(journal_t *j, struct buffer_head *bh)
1027 {
1028 struct jbd2_journal_block_tail *tail;
1029 __u32 csum;
1030
1031 if (!jbd2_journal_has_csum_v2or3(j))
1032 return;
1033
1034 tail = (struct jbd2_journal_block_tail *)(bh->b_data + j->j_blocksize -
1035 sizeof(struct jbd2_journal_block_tail));
1036 tail->t_checksum = 0;
1037 csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize);
1038 tail->t_checksum = cpu_to_be32(csum);
1039 }
1040
1041 /*
1042 * Return tid of the oldest transaction in the journal and block in the journal
1043 * where the transaction starts.
1044 *
1045 * If the journal is now empty, return which will be the next transaction ID
1046 * we will write and where will that transaction start.
1047 *
1048 * The return value is 0 if journal tail cannot be pushed any further, 1 if
1049 * it can.
1050 */
jbd2_journal_get_log_tail(journal_t * journal,tid_t * tid,unsigned long * block)1051 int jbd2_journal_get_log_tail(journal_t *journal, tid_t *tid,
1052 unsigned long *block)
1053 {
1054 transaction_t *transaction;
1055 int ret;
1056
1057 read_lock(&journal->j_state_lock);
1058 spin_lock(&journal->j_list_lock);
1059 transaction = journal->j_checkpoint_transactions;
1060 if (transaction) {
1061 *tid = transaction->t_tid;
1062 *block = transaction->t_log_start;
1063 } else if ((transaction = journal->j_committing_transaction) != NULL) {
1064 *tid = transaction->t_tid;
1065 *block = transaction->t_log_start;
1066 } else if ((transaction = journal->j_running_transaction) != NULL) {
1067 *tid = transaction->t_tid;
1068 *block = journal->j_head;
1069 } else {
1070 *tid = journal->j_transaction_sequence;
1071 *block = journal->j_head;
1072 }
1073 ret = tid_gt(*tid, journal->j_tail_sequence);
1074 spin_unlock(&journal->j_list_lock);
1075 read_unlock(&journal->j_state_lock);
1076
1077 return ret;
1078 }
1079
1080 /*
1081 * Update information in journal structure and in on disk journal superblock
1082 * about log tail. This function does not check whether information passed in
1083 * really pushes log tail further. It's responsibility of the caller to make
1084 * sure provided log tail information is valid (e.g. by holding
1085 * j_checkpoint_mutex all the time between computing log tail and calling this
1086 * function as is the case with jbd2_cleanup_journal_tail()).
1087 *
1088 * Requires j_checkpoint_mutex
1089 */
__jbd2_update_log_tail(journal_t * journal,tid_t tid,unsigned long block)1090 int __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block)
1091 {
1092 unsigned long freed;
1093 int ret;
1094
1095 BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
1096
1097 /*
1098 * We cannot afford for write to remain in drive's caches since as
1099 * soon as we update j_tail, next transaction can start reusing journal
1100 * space and if we lose sb update during power failure we'd replay
1101 * old transaction with possibly newly overwritten data.
1102 */
1103 ret = jbd2_journal_update_sb_log_tail(journal, tid, block, REQ_FUA);
1104 if (ret)
1105 goto out;
1106
1107 write_lock(&journal->j_state_lock);
1108 freed = block - journal->j_tail;
1109 if (block < journal->j_tail)
1110 freed += journal->j_last - journal->j_first;
1111
1112 trace_jbd2_update_log_tail(journal, tid, block, freed);
1113 jbd2_debug(1,
1114 "Cleaning journal tail from %u to %u (offset %lu), "
1115 "freeing %lu\n",
1116 journal->j_tail_sequence, tid, block, freed);
1117
1118 journal->j_free += freed;
1119 journal->j_tail_sequence = tid;
1120 journal->j_tail = block;
1121 write_unlock(&journal->j_state_lock);
1122
1123 out:
1124 return ret;
1125 }
1126
1127 /*
1128 * This is a variation of __jbd2_update_log_tail which checks for validity of
1129 * provided log tail and locks j_checkpoint_mutex. So it is safe against races
1130 * with other threads updating log tail.
1131 */
jbd2_update_log_tail(journal_t * journal,tid_t tid,unsigned long block)1132 void jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block)
1133 {
1134 mutex_lock_io(&journal->j_checkpoint_mutex);
1135 if (tid_gt(tid, journal->j_tail_sequence))
1136 __jbd2_update_log_tail(journal, tid, block);
1137 mutex_unlock(&journal->j_checkpoint_mutex);
1138 }
1139
1140 struct jbd2_stats_proc_session {
1141 journal_t *journal;
1142 struct transaction_stats_s *stats;
1143 int start;
1144 int max;
1145 };
1146
jbd2_seq_info_start(struct seq_file * seq,loff_t * pos)1147 static void *jbd2_seq_info_start(struct seq_file *seq, loff_t *pos)
1148 {
1149 return *pos ? NULL : SEQ_START_TOKEN;
1150 }
1151
jbd2_seq_info_next(struct seq_file * seq,void * v,loff_t * pos)1152 static void *jbd2_seq_info_next(struct seq_file *seq, void *v, loff_t *pos)
1153 {
1154 (*pos)++;
1155 return NULL;
1156 }
1157
jbd2_seq_info_show(struct seq_file * seq,void * v)1158 static int jbd2_seq_info_show(struct seq_file *seq, void *v)
1159 {
1160 struct jbd2_stats_proc_session *s = seq->private;
1161
1162 if (v != SEQ_START_TOKEN)
1163 return 0;
1164 seq_printf(seq, "%lu transactions (%lu requested), "
1165 "each up to %u blocks\n",
1166 s->stats->ts_tid, s->stats->ts_requested,
1167 s->journal->j_max_transaction_buffers);
1168 if (s->stats->ts_tid == 0)
1169 return 0;
1170 seq_printf(seq, "average: \n %ums waiting for transaction\n",
1171 jiffies_to_msecs(s->stats->run.rs_wait / s->stats->ts_tid));
1172 seq_printf(seq, " %ums request delay\n",
1173 (s->stats->ts_requested == 0) ? 0 :
1174 jiffies_to_msecs(s->stats->run.rs_request_delay /
1175 s->stats->ts_requested));
1176 seq_printf(seq, " %ums running transaction\n",
1177 jiffies_to_msecs(s->stats->run.rs_running / s->stats->ts_tid));
1178 seq_printf(seq, " %ums transaction was being locked\n",
1179 jiffies_to_msecs(s->stats->run.rs_locked / s->stats->ts_tid));
1180 seq_printf(seq, " %ums flushing data (in ordered mode)\n",
1181 jiffies_to_msecs(s->stats->run.rs_flushing / s->stats->ts_tid));
1182 seq_printf(seq, " %ums logging transaction\n",
1183 jiffies_to_msecs(s->stats->run.rs_logging / s->stats->ts_tid));
1184 seq_printf(seq, " %lluus average transaction commit time\n",
1185 div_u64(s->journal->j_average_commit_time, 1000));
1186 seq_printf(seq, " %lu handles per transaction\n",
1187 s->stats->run.rs_handle_count / s->stats->ts_tid);
1188 seq_printf(seq, " %lu blocks per transaction\n",
1189 s->stats->run.rs_blocks / s->stats->ts_tid);
1190 seq_printf(seq, " %lu logged blocks per transaction\n",
1191 s->stats->run.rs_blocks_logged / s->stats->ts_tid);
1192 return 0;
1193 }
1194
jbd2_seq_info_stop(struct seq_file * seq,void * v)1195 static void jbd2_seq_info_stop(struct seq_file *seq, void *v)
1196 {
1197 }
1198
1199 static const struct seq_operations jbd2_seq_info_ops = {
1200 .start = jbd2_seq_info_start,
1201 .next = jbd2_seq_info_next,
1202 .stop = jbd2_seq_info_stop,
1203 .show = jbd2_seq_info_show,
1204 };
1205
jbd2_seq_info_open(struct inode * inode,struct file * file)1206 static int jbd2_seq_info_open(struct inode *inode, struct file *file)
1207 {
1208 journal_t *journal = pde_data(inode);
1209 struct jbd2_stats_proc_session *s;
1210 int rc, size;
1211
1212 s = kmalloc(sizeof(*s), GFP_KERNEL);
1213 if (s == NULL)
1214 return -ENOMEM;
1215 size = sizeof(struct transaction_stats_s);
1216 s->stats = kmalloc(size, GFP_KERNEL);
1217 if (s->stats == NULL) {
1218 kfree(s);
1219 return -ENOMEM;
1220 }
1221 spin_lock(&journal->j_history_lock);
1222 memcpy(s->stats, &journal->j_stats, size);
1223 s->journal = journal;
1224 spin_unlock(&journal->j_history_lock);
1225
1226 rc = seq_open(file, &jbd2_seq_info_ops);
1227 if (rc == 0) {
1228 struct seq_file *m = file->private_data;
1229 m->private = s;
1230 } else {
1231 kfree(s->stats);
1232 kfree(s);
1233 }
1234 return rc;
1235
1236 }
1237
jbd2_seq_info_release(struct inode * inode,struct file * file)1238 static int jbd2_seq_info_release(struct inode *inode, struct file *file)
1239 {
1240 struct seq_file *seq = file->private_data;
1241 struct jbd2_stats_proc_session *s = seq->private;
1242 kfree(s->stats);
1243 kfree(s);
1244 return seq_release(inode, file);
1245 }
1246
1247 static const struct proc_ops jbd2_info_proc_ops = {
1248 .proc_open = jbd2_seq_info_open,
1249 .proc_read = seq_read,
1250 .proc_lseek = seq_lseek,
1251 .proc_release = jbd2_seq_info_release,
1252 };
1253
1254 static struct proc_dir_entry *proc_jbd2_stats;
1255
jbd2_stats_proc_init(journal_t * journal)1256 static void jbd2_stats_proc_init(journal_t *journal)
1257 {
1258 journal->j_proc_entry = proc_mkdir(journal->j_devname, proc_jbd2_stats);
1259 if (journal->j_proc_entry) {
1260 proc_create_data("info", S_IRUGO, journal->j_proc_entry,
1261 &jbd2_info_proc_ops, journal);
1262 }
1263 }
1264
jbd2_stats_proc_exit(journal_t * journal)1265 static void jbd2_stats_proc_exit(journal_t *journal)
1266 {
1267 remove_proc_entry("info", journal->j_proc_entry);
1268 remove_proc_entry(journal->j_devname, proc_jbd2_stats);
1269 }
1270
1271 /* Minimum size of descriptor tag */
jbd2_min_tag_size(void)1272 static int jbd2_min_tag_size(void)
1273 {
1274 /*
1275 * Tag with 32-bit block numbers does not use last four bytes of the
1276 * structure
1277 */
1278 return sizeof(journal_block_tag_t) - 4;
1279 }
1280
1281 /**
1282 * jbd2_journal_shrink_scan()
1283 * @shrink: shrinker to work on
1284 * @sc: reclaim request to process
1285 *
1286 * Scan the checkpointed buffer on the checkpoint list and release the
1287 * journal_head.
1288 */
jbd2_journal_shrink_scan(struct shrinker * shrink,struct shrink_control * sc)1289 static unsigned long jbd2_journal_shrink_scan(struct shrinker *shrink,
1290 struct shrink_control *sc)
1291 {
1292 journal_t *journal = container_of(shrink, journal_t, j_shrinker);
1293 unsigned long nr_to_scan = sc->nr_to_scan;
1294 unsigned long nr_shrunk;
1295 unsigned long count;
1296
1297 count = percpu_counter_read_positive(&journal->j_checkpoint_jh_count);
1298 trace_jbd2_shrink_scan_enter(journal, sc->nr_to_scan, count);
1299
1300 nr_shrunk = jbd2_journal_shrink_checkpoint_list(journal, &nr_to_scan);
1301
1302 count = percpu_counter_read_positive(&journal->j_checkpoint_jh_count);
1303 trace_jbd2_shrink_scan_exit(journal, nr_to_scan, nr_shrunk, count);
1304
1305 return nr_shrunk;
1306 }
1307
1308 /**
1309 * jbd2_journal_shrink_count()
1310 * @shrink: shrinker to work on
1311 * @sc: reclaim request to process
1312 *
1313 * Count the number of checkpoint buffers on the checkpoint list.
1314 */
jbd2_journal_shrink_count(struct shrinker * shrink,struct shrink_control * sc)1315 static unsigned long jbd2_journal_shrink_count(struct shrinker *shrink,
1316 struct shrink_control *sc)
1317 {
1318 journal_t *journal = container_of(shrink, journal_t, j_shrinker);
1319 unsigned long count;
1320
1321 count = percpu_counter_read_positive(&journal->j_checkpoint_jh_count);
1322 trace_jbd2_shrink_count(journal, sc->nr_to_scan, count);
1323
1324 return count;
1325 }
1326
1327 /*
1328 * If the journal init or create aborts, we need to mark the journal
1329 * superblock as being NULL to prevent the journal destroy from writing
1330 * back a bogus superblock.
1331 */
journal_fail_superblock(journal_t * journal)1332 static void journal_fail_superblock(journal_t *journal)
1333 {
1334 struct buffer_head *bh = journal->j_sb_buffer;
1335 brelse(bh);
1336 journal->j_sb_buffer = NULL;
1337 }
1338
1339 /*
1340 * Check the superblock for a given journal, performing initial
1341 * validation of the format.
1342 */
journal_check_superblock(journal_t * journal)1343 static int journal_check_superblock(journal_t *journal)
1344 {
1345 journal_superblock_t *sb = journal->j_superblock;
1346 int num_fc_blks;
1347 int err = -EINVAL;
1348
1349 if (sb->s_header.h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER) ||
1350 sb->s_blocksize != cpu_to_be32(journal->j_blocksize)) {
1351 printk(KERN_WARNING "JBD2: no valid journal superblock found\n");
1352 return err;
1353 }
1354
1355 if (be32_to_cpu(sb->s_header.h_blocktype) != JBD2_SUPERBLOCK_V1 &&
1356 be32_to_cpu(sb->s_header.h_blocktype) != JBD2_SUPERBLOCK_V2) {
1357 printk(KERN_WARNING "JBD2: unrecognised superblock format ID\n");
1358 return err;
1359 }
1360
1361 if (be32_to_cpu(sb->s_maxlen) > journal->j_total_len) {
1362 printk(KERN_WARNING "JBD2: journal file too short\n");
1363 return err;
1364 }
1365
1366 if (be32_to_cpu(sb->s_first) == 0 ||
1367 be32_to_cpu(sb->s_first) >= journal->j_total_len) {
1368 printk(KERN_WARNING
1369 "JBD2: Invalid start block of journal: %u\n",
1370 be32_to_cpu(sb->s_first));
1371 return err;
1372 }
1373
1374 /*
1375 * If this is a V2 superblock, then we have to check the
1376 * features flags on it.
1377 */
1378 if (!jbd2_format_support_feature(journal))
1379 return 0;
1380
1381 if ((sb->s_feature_ro_compat &
1382 ~cpu_to_be32(JBD2_KNOWN_ROCOMPAT_FEATURES)) ||
1383 (sb->s_feature_incompat &
1384 ~cpu_to_be32(JBD2_KNOWN_INCOMPAT_FEATURES))) {
1385 printk(KERN_WARNING "JBD2: Unrecognised features on journal\n");
1386 return err;
1387 }
1388
1389 num_fc_blks = jbd2_has_feature_fast_commit(journal) ?
1390 jbd2_journal_get_num_fc_blks(sb) : 0;
1391 if (be32_to_cpu(sb->s_maxlen) < JBD2_MIN_JOURNAL_BLOCKS ||
1392 be32_to_cpu(sb->s_maxlen) - JBD2_MIN_JOURNAL_BLOCKS < num_fc_blks) {
1393 printk(KERN_ERR "JBD2: journal file too short %u,%d\n",
1394 be32_to_cpu(sb->s_maxlen), num_fc_blks);
1395 return err;
1396 }
1397
1398 if (jbd2_has_feature_csum2(journal) &&
1399 jbd2_has_feature_csum3(journal)) {
1400 /* Can't have checksum v2 and v3 at the same time! */
1401 printk(KERN_ERR "JBD2: Can't enable checksumming v2 and v3 "
1402 "at the same time!\n");
1403 return err;
1404 }
1405
1406 if (jbd2_journal_has_csum_v2or3_feature(journal) &&
1407 jbd2_has_feature_checksum(journal)) {
1408 /* Can't have checksum v1 and v2 on at the same time! */
1409 printk(KERN_ERR "JBD2: Can't enable checksumming v1 and v2/3 "
1410 "at the same time!\n");
1411 return err;
1412 }
1413
1414 /* Load the checksum driver */
1415 if (jbd2_journal_has_csum_v2or3_feature(journal)) {
1416 if (sb->s_checksum_type != JBD2_CRC32C_CHKSUM) {
1417 printk(KERN_ERR "JBD2: Unknown checksum type\n");
1418 return err;
1419 }
1420
1421 journal->j_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
1422 if (IS_ERR(journal->j_chksum_driver)) {
1423 printk(KERN_ERR "JBD2: Cannot load crc32c driver.\n");
1424 err = PTR_ERR(journal->j_chksum_driver);
1425 journal->j_chksum_driver = NULL;
1426 return err;
1427 }
1428 /* Check superblock checksum */
1429 if (sb->s_checksum != jbd2_superblock_csum(journal, sb)) {
1430 printk(KERN_ERR "JBD2: journal checksum error\n");
1431 err = -EFSBADCRC;
1432 return err;
1433 }
1434 }
1435
1436 return 0;
1437 }
1438
journal_revoke_records_per_block(journal_t * journal)1439 static int journal_revoke_records_per_block(journal_t *journal)
1440 {
1441 int record_size;
1442 int space = journal->j_blocksize - sizeof(jbd2_journal_revoke_header_t);
1443
1444 if (jbd2_has_feature_64bit(journal))
1445 record_size = 8;
1446 else
1447 record_size = 4;
1448
1449 if (jbd2_journal_has_csum_v2or3(journal))
1450 space -= sizeof(struct jbd2_journal_block_tail);
1451 return space / record_size;
1452 }
1453
1454 /*
1455 * Load the on-disk journal superblock and read the key fields into the
1456 * journal_t.
1457 */
journal_load_superblock(journal_t * journal)1458 static int journal_load_superblock(journal_t *journal)
1459 {
1460 int err;
1461 struct buffer_head *bh;
1462 journal_superblock_t *sb;
1463
1464 bh = getblk_unmovable(journal->j_dev, journal->j_blk_offset,
1465 journal->j_blocksize);
1466 if (bh)
1467 err = bh_read(bh, 0);
1468 if (!bh || err < 0) {
1469 pr_err("%s: Cannot read journal superblock\n", __func__);
1470 brelse(bh);
1471 return -EIO;
1472 }
1473
1474 journal->j_sb_buffer = bh;
1475 sb = (journal_superblock_t *)bh->b_data;
1476 journal->j_superblock = sb;
1477 err = journal_check_superblock(journal);
1478 if (err) {
1479 journal_fail_superblock(journal);
1480 return err;
1481 }
1482
1483 journal->j_tail_sequence = be32_to_cpu(sb->s_sequence);
1484 journal->j_tail = be32_to_cpu(sb->s_start);
1485 journal->j_first = be32_to_cpu(sb->s_first);
1486 journal->j_errno = be32_to_cpu(sb->s_errno);
1487 journal->j_last = be32_to_cpu(sb->s_maxlen);
1488
1489 if (be32_to_cpu(sb->s_maxlen) < journal->j_total_len)
1490 journal->j_total_len = be32_to_cpu(sb->s_maxlen);
1491 /* Precompute checksum seed for all metadata */
1492 if (jbd2_journal_has_csum_v2or3(journal))
1493 journal->j_csum_seed = jbd2_chksum(journal, ~0, sb->s_uuid,
1494 sizeof(sb->s_uuid));
1495 journal->j_revoke_records_per_block =
1496 journal_revoke_records_per_block(journal);
1497
1498 if (jbd2_has_feature_fast_commit(journal)) {
1499 journal->j_fc_last = be32_to_cpu(sb->s_maxlen);
1500 journal->j_last = journal->j_fc_last -
1501 jbd2_journal_get_num_fc_blks(sb);
1502 journal->j_fc_first = journal->j_last + 1;
1503 journal->j_fc_off = 0;
1504 }
1505
1506 return 0;
1507 }
1508
1509
1510 /*
1511 * Management for journal control blocks: functions to create and
1512 * destroy journal_t structures, and to initialise and read existing
1513 * journal blocks from disk. */
1514
1515 /* First: create and setup a journal_t object in memory. We initialise
1516 * very few fields yet: that has to wait until we have created the
1517 * journal structures from from scratch, or loaded them from disk. */
1518
journal_init_common(struct block_device * bdev,struct block_device * fs_dev,unsigned long long start,int len,int blocksize)1519 static journal_t *journal_init_common(struct block_device *bdev,
1520 struct block_device *fs_dev,
1521 unsigned long long start, int len, int blocksize)
1522 {
1523 static struct lock_class_key jbd2_trans_commit_key;
1524 journal_t *journal;
1525 int err;
1526 int n;
1527
1528 journal = kzalloc(sizeof(*journal), GFP_KERNEL);
1529 if (!journal)
1530 return ERR_PTR(-ENOMEM);
1531
1532 journal->j_blocksize = blocksize;
1533 journal->j_dev = bdev;
1534 journal->j_fs_dev = fs_dev;
1535 journal->j_blk_offset = start;
1536 journal->j_total_len = len;
1537
1538 err = journal_load_superblock(journal);
1539 if (err)
1540 goto err_cleanup;
1541
1542 init_waitqueue_head(&journal->j_wait_transaction_locked);
1543 init_waitqueue_head(&journal->j_wait_done_commit);
1544 init_waitqueue_head(&journal->j_wait_commit);
1545 init_waitqueue_head(&journal->j_wait_updates);
1546 init_waitqueue_head(&journal->j_wait_reserved);
1547 init_waitqueue_head(&journal->j_fc_wait);
1548 mutex_init(&journal->j_abort_mutex);
1549 mutex_init(&journal->j_barrier);
1550 mutex_init(&journal->j_checkpoint_mutex);
1551 spin_lock_init(&journal->j_revoke_lock);
1552 spin_lock_init(&journal->j_list_lock);
1553 spin_lock_init(&journal->j_history_lock);
1554 rwlock_init(&journal->j_state_lock);
1555
1556 journal->j_commit_interval = (HZ * JBD2_DEFAULT_MAX_COMMIT_AGE);
1557 journal->j_min_batch_time = 0;
1558 journal->j_max_batch_time = 15000; /* 15ms */
1559 atomic_set(&journal->j_reserved_credits, 0);
1560 lockdep_init_map(&journal->j_trans_commit_map, "jbd2_handle",
1561 &jbd2_trans_commit_key, 0);
1562
1563 /* The journal is marked for error until we succeed with recovery! */
1564 journal->j_flags = JBD2_ABORT;
1565
1566 /* Set up a default-sized revoke table for the new mount. */
1567 err = jbd2_journal_init_revoke(journal, JOURNAL_REVOKE_DEFAULT_HASH);
1568 if (err)
1569 goto err_cleanup;
1570
1571 /*
1572 * journal descriptor can store up to n blocks, we need enough
1573 * buffers to write out full descriptor block.
1574 */
1575 err = -ENOMEM;
1576 n = journal->j_blocksize / jbd2_min_tag_size();
1577 journal->j_wbufsize = n;
1578 journal->j_fc_wbuf = NULL;
1579 journal->j_wbuf = kmalloc_array(n, sizeof(struct buffer_head *),
1580 GFP_KERNEL);
1581 if (!journal->j_wbuf)
1582 goto err_cleanup;
1583
1584 err = percpu_counter_init(&journal->j_checkpoint_jh_count, 0,
1585 GFP_KERNEL);
1586 if (err)
1587 goto err_cleanup;
1588
1589 journal->j_shrink_transaction = NULL;
1590 journal->j_shrinker.scan_objects = jbd2_journal_shrink_scan;
1591 journal->j_shrinker.count_objects = jbd2_journal_shrink_count;
1592 journal->j_shrinker.seeks = DEFAULT_SEEKS;
1593 journal->j_shrinker.batch = journal->j_max_transaction_buffers;
1594 err = register_shrinker(&journal->j_shrinker, "jbd2-journal:(%u:%u)",
1595 MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev));
1596 if (err)
1597 goto err_cleanup;
1598
1599 return journal;
1600
1601 err_cleanup:
1602 percpu_counter_destroy(&journal->j_checkpoint_jh_count);
1603 if (journal->j_chksum_driver)
1604 crypto_free_shash(journal->j_chksum_driver);
1605 kfree(journal->j_wbuf);
1606 jbd2_journal_destroy_revoke(journal);
1607 journal_fail_superblock(journal);
1608 kfree(journal);
1609 return ERR_PTR(err);
1610 }
1611
1612 /* jbd2_journal_init_dev and jbd2_journal_init_inode:
1613 *
1614 * Create a journal structure assigned some fixed set of disk blocks to
1615 * the journal. We don't actually touch those disk blocks yet, but we
1616 * need to set up all of the mapping information to tell the journaling
1617 * system where the journal blocks are.
1618 *
1619 */
1620
1621 /**
1622 * journal_t * jbd2_journal_init_dev() - creates and initialises a journal structure
1623 * @bdev: Block device on which to create the journal
1624 * @fs_dev: Device which hold journalled filesystem for this journal.
1625 * @start: Block nr Start of journal.
1626 * @len: Length of the journal in blocks.
1627 * @blocksize: blocksize of journalling device
1628 *
1629 * Returns: a newly created journal_t *
1630 *
1631 * jbd2_journal_init_dev creates a journal which maps a fixed contiguous
1632 * range of blocks on an arbitrary block device.
1633 *
1634 */
jbd2_journal_init_dev(struct block_device * bdev,struct block_device * fs_dev,unsigned long long start,int len,int blocksize)1635 journal_t *jbd2_journal_init_dev(struct block_device *bdev,
1636 struct block_device *fs_dev,
1637 unsigned long long start, int len, int blocksize)
1638 {
1639 journal_t *journal;
1640
1641 journal = journal_init_common(bdev, fs_dev, start, len, blocksize);
1642 if (IS_ERR(journal))
1643 return ERR_CAST(journal);
1644
1645 snprintf(journal->j_devname, sizeof(journal->j_devname),
1646 "%pg", journal->j_dev);
1647 strreplace(journal->j_devname, '/', '!');
1648 jbd2_stats_proc_init(journal);
1649
1650 return journal;
1651 }
1652
1653 /**
1654 * journal_t * jbd2_journal_init_inode () - creates a journal which maps to a inode.
1655 * @inode: An inode to create the journal in
1656 *
1657 * jbd2_journal_init_inode creates a journal which maps an on-disk inode as
1658 * the journal. The inode must exist already, must support bmap() and
1659 * must have all data blocks preallocated.
1660 */
jbd2_journal_init_inode(struct inode * inode)1661 journal_t *jbd2_journal_init_inode(struct inode *inode)
1662 {
1663 journal_t *journal;
1664 sector_t blocknr;
1665 int err = 0;
1666
1667 blocknr = 0;
1668 err = bmap(inode, &blocknr);
1669 if (err || !blocknr) {
1670 pr_err("%s: Cannot locate journal superblock\n", __func__);
1671 return err ? ERR_PTR(err) : ERR_PTR(-EINVAL);
1672 }
1673
1674 jbd2_debug(1, "JBD2: inode %s/%ld, size %lld, bits %d, blksize %ld\n",
1675 inode->i_sb->s_id, inode->i_ino, (long long) inode->i_size,
1676 inode->i_sb->s_blocksize_bits, inode->i_sb->s_blocksize);
1677
1678 journal = journal_init_common(inode->i_sb->s_bdev, inode->i_sb->s_bdev,
1679 blocknr, inode->i_size >> inode->i_sb->s_blocksize_bits,
1680 inode->i_sb->s_blocksize);
1681 if (IS_ERR(journal))
1682 return ERR_CAST(journal);
1683
1684 journal->j_inode = inode;
1685 snprintf(journal->j_devname, sizeof(journal->j_devname),
1686 "%pg-%lu", journal->j_dev, journal->j_inode->i_ino);
1687 strreplace(journal->j_devname, '/', '!');
1688 jbd2_stats_proc_init(journal);
1689
1690 return journal;
1691 }
1692
1693 /*
1694 * Given a journal_t structure, initialise the various fields for
1695 * startup of a new journaling session. We use this both when creating
1696 * a journal, and after recovering an old journal to reset it for
1697 * subsequent use.
1698 */
1699
journal_reset(journal_t * journal)1700 static int journal_reset(journal_t *journal)
1701 {
1702 journal_superblock_t *sb = journal->j_superblock;
1703 unsigned long long first, last;
1704
1705 first = be32_to_cpu(sb->s_first);
1706 last = be32_to_cpu(sb->s_maxlen);
1707 if (first + JBD2_MIN_JOURNAL_BLOCKS > last + 1) {
1708 printk(KERN_ERR "JBD2: Journal too short (blocks %llu-%llu).\n",
1709 first, last);
1710 journal_fail_superblock(journal);
1711 return -EINVAL;
1712 }
1713
1714 journal->j_first = first;
1715 journal->j_last = last;
1716
1717 if (journal->j_head != 0 && journal->j_flags & JBD2_CYCLE_RECORD) {
1718 /*
1719 * Disable the cycled recording mode if the journal head block
1720 * number is not correct.
1721 */
1722 if (journal->j_head < first || journal->j_head >= last) {
1723 printk(KERN_WARNING "JBD2: Incorrect Journal head block %lu, "
1724 "disable journal_cycle_record\n",
1725 journal->j_head);
1726 journal->j_head = journal->j_first;
1727 }
1728 } else {
1729 journal->j_head = journal->j_first;
1730 }
1731 journal->j_tail = journal->j_head;
1732 journal->j_free = journal->j_last - journal->j_first;
1733
1734 journal->j_tail_sequence = journal->j_transaction_sequence;
1735 journal->j_commit_sequence = journal->j_transaction_sequence - 1;
1736 journal->j_commit_request = journal->j_commit_sequence;
1737
1738 journal->j_max_transaction_buffers = jbd2_journal_get_max_txn_bufs(journal);
1739
1740 /*
1741 * Now that journal recovery is done, turn fast commits off here. This
1742 * way, if fast commit was enabled before the crash but if now FS has
1743 * disabled it, we don't enable fast commits.
1744 */
1745 jbd2_clear_feature_fast_commit(journal);
1746
1747 /*
1748 * As a special case, if the on-disk copy is already marked as needing
1749 * no recovery (s_start == 0), then we can safely defer the superblock
1750 * update until the next commit by setting JBD2_FLUSHED. This avoids
1751 * attempting a write to a potential-readonly device.
1752 */
1753 if (sb->s_start == 0) {
1754 jbd2_debug(1, "JBD2: Skipping superblock update on recovered sb "
1755 "(start %ld, seq %u, errno %d)\n",
1756 journal->j_tail, journal->j_tail_sequence,
1757 journal->j_errno);
1758 journal->j_flags |= JBD2_FLUSHED;
1759 } else {
1760 /* Lock here to make assertions happy... */
1761 mutex_lock_io(&journal->j_checkpoint_mutex);
1762 /*
1763 * Update log tail information. We use REQ_FUA since new
1764 * transaction will start reusing journal space and so we
1765 * must make sure information about current log tail is on
1766 * disk before that.
1767 */
1768 jbd2_journal_update_sb_log_tail(journal,
1769 journal->j_tail_sequence,
1770 journal->j_tail, REQ_FUA);
1771 mutex_unlock(&journal->j_checkpoint_mutex);
1772 }
1773 return jbd2_journal_start_thread(journal);
1774 }
1775
1776 /*
1777 * This function expects that the caller will have locked the journal
1778 * buffer head, and will return with it unlocked
1779 */
jbd2_write_superblock(journal_t * journal,blk_opf_t write_flags)1780 static int jbd2_write_superblock(journal_t *journal, blk_opf_t write_flags)
1781 {
1782 struct buffer_head *bh = journal->j_sb_buffer;
1783 journal_superblock_t *sb = journal->j_superblock;
1784 int ret = 0;
1785
1786 /* Buffer got discarded which means block device got invalidated */
1787 if (!buffer_mapped(bh)) {
1788 unlock_buffer(bh);
1789 return -EIO;
1790 }
1791
1792 /*
1793 * Always set high priority flags to exempt from block layer's
1794 * QOS policies, e.g. writeback throttle.
1795 */
1796 write_flags |= JBD2_JOURNAL_REQ_FLAGS;
1797 if (!(journal->j_flags & JBD2_BARRIER))
1798 write_flags &= ~(REQ_FUA | REQ_PREFLUSH);
1799
1800 trace_jbd2_write_superblock(journal, write_flags);
1801
1802 if (buffer_write_io_error(bh)) {
1803 /*
1804 * Oh, dear. A previous attempt to write the journal
1805 * superblock failed. This could happen because the
1806 * USB device was yanked out. Or it could happen to
1807 * be a transient write error and maybe the block will
1808 * be remapped. Nothing we can do but to retry the
1809 * write and hope for the best.
1810 */
1811 printk(KERN_ERR "JBD2: previous I/O error detected "
1812 "for journal superblock update for %s.\n",
1813 journal->j_devname);
1814 clear_buffer_write_io_error(bh);
1815 set_buffer_uptodate(bh);
1816 }
1817 if (jbd2_journal_has_csum_v2or3(journal))
1818 sb->s_checksum = jbd2_superblock_csum(journal, sb);
1819 get_bh(bh);
1820 bh->b_end_io = end_buffer_write_sync;
1821 submit_bh(REQ_OP_WRITE | write_flags, bh);
1822 wait_on_buffer(bh);
1823 if (buffer_write_io_error(bh)) {
1824 clear_buffer_write_io_error(bh);
1825 set_buffer_uptodate(bh);
1826 ret = -EIO;
1827 }
1828 if (ret) {
1829 printk(KERN_ERR "JBD2: I/O error when updating journal superblock for %s.\n",
1830 journal->j_devname);
1831 if (!is_journal_aborted(journal))
1832 jbd2_journal_abort(journal, ret);
1833 }
1834
1835 return ret;
1836 }
1837
1838 /**
1839 * jbd2_journal_update_sb_log_tail() - Update log tail in journal sb on disk.
1840 * @journal: The journal to update.
1841 * @tail_tid: TID of the new transaction at the tail of the log
1842 * @tail_block: The first block of the transaction at the tail of the log
1843 * @write_flags: Flags for the journal sb write operation
1844 *
1845 * Update a journal's superblock information about log tail and write it to
1846 * disk, waiting for the IO to complete.
1847 */
jbd2_journal_update_sb_log_tail(journal_t * journal,tid_t tail_tid,unsigned long tail_block,blk_opf_t write_flags)1848 int jbd2_journal_update_sb_log_tail(journal_t *journal, tid_t tail_tid,
1849 unsigned long tail_block,
1850 blk_opf_t write_flags)
1851 {
1852 journal_superblock_t *sb = journal->j_superblock;
1853 int ret;
1854
1855 if (is_journal_aborted(journal))
1856 return -EIO;
1857 if (test_bit(JBD2_CHECKPOINT_IO_ERROR, &journal->j_atomic_flags)) {
1858 jbd2_journal_abort(journal, -EIO);
1859 return -EIO;
1860 }
1861
1862 BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
1863 jbd2_debug(1, "JBD2: updating superblock (start %lu, seq %u)\n",
1864 tail_block, tail_tid);
1865
1866 lock_buffer(journal->j_sb_buffer);
1867 sb->s_sequence = cpu_to_be32(tail_tid);
1868 sb->s_start = cpu_to_be32(tail_block);
1869
1870 ret = jbd2_write_superblock(journal, write_flags);
1871 if (ret)
1872 goto out;
1873
1874 /* Log is no longer empty */
1875 write_lock(&journal->j_state_lock);
1876 WARN_ON(!sb->s_sequence);
1877 journal->j_flags &= ~JBD2_FLUSHED;
1878 write_unlock(&journal->j_state_lock);
1879
1880 out:
1881 return ret;
1882 }
1883
1884 /**
1885 * jbd2_mark_journal_empty() - Mark on disk journal as empty.
1886 * @journal: The journal to update.
1887 * @write_flags: Flags for the journal sb write operation
1888 *
1889 * Update a journal's dynamic superblock fields to show that journal is empty.
1890 * Write updated superblock to disk waiting for IO to complete.
1891 */
jbd2_mark_journal_empty(journal_t * journal,blk_opf_t write_flags)1892 static void jbd2_mark_journal_empty(journal_t *journal, blk_opf_t write_flags)
1893 {
1894 journal_superblock_t *sb = journal->j_superblock;
1895 bool had_fast_commit = false;
1896
1897 BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
1898 lock_buffer(journal->j_sb_buffer);
1899 if (sb->s_start == 0) { /* Is it already empty? */
1900 unlock_buffer(journal->j_sb_buffer);
1901 return;
1902 }
1903
1904 jbd2_debug(1, "JBD2: Marking journal as empty (seq %u)\n",
1905 journal->j_tail_sequence);
1906
1907 sb->s_sequence = cpu_to_be32(journal->j_tail_sequence);
1908 sb->s_start = cpu_to_be32(0);
1909 sb->s_head = cpu_to_be32(journal->j_head);
1910 if (jbd2_has_feature_fast_commit(journal)) {
1911 /*
1912 * When journal is clean, no need to commit fast commit flag and
1913 * make file system incompatible with older kernels.
1914 */
1915 jbd2_clear_feature_fast_commit(journal);
1916 had_fast_commit = true;
1917 }
1918
1919 jbd2_write_superblock(journal, write_flags);
1920
1921 if (had_fast_commit)
1922 jbd2_set_feature_fast_commit(journal);
1923
1924 /* Log is no longer empty */
1925 write_lock(&journal->j_state_lock);
1926 journal->j_flags |= JBD2_FLUSHED;
1927 write_unlock(&journal->j_state_lock);
1928 }
1929
1930 /**
1931 * __jbd2_journal_erase() - Discard or zeroout journal blocks (excluding superblock)
1932 * @journal: The journal to erase.
1933 * @flags: A discard/zeroout request is sent for each physically contigous
1934 * region of the journal. Either JBD2_JOURNAL_FLUSH_DISCARD or
1935 * JBD2_JOURNAL_FLUSH_ZEROOUT must be set to determine which operation
1936 * to perform.
1937 *
1938 * Note: JBD2_JOURNAL_FLUSH_ZEROOUT attempts to use hardware offload. Zeroes
1939 * will be explicitly written if no hardware offload is available, see
1940 * blkdev_issue_zeroout for more details.
1941 */
__jbd2_journal_erase(journal_t * journal,unsigned int flags)1942 static int __jbd2_journal_erase(journal_t *journal, unsigned int flags)
1943 {
1944 int err = 0;
1945 unsigned long block, log_offset; /* logical */
1946 unsigned long long phys_block, block_start, block_stop; /* physical */
1947 loff_t byte_start, byte_stop, byte_count;
1948
1949 /* flags must be set to either discard or zeroout */
1950 if ((flags & ~JBD2_JOURNAL_FLUSH_VALID) || !flags ||
1951 ((flags & JBD2_JOURNAL_FLUSH_DISCARD) &&
1952 (flags & JBD2_JOURNAL_FLUSH_ZEROOUT)))
1953 return -EINVAL;
1954
1955 if ((flags & JBD2_JOURNAL_FLUSH_DISCARD) &&
1956 !bdev_max_discard_sectors(journal->j_dev))
1957 return -EOPNOTSUPP;
1958
1959 /*
1960 * lookup block mapping and issue discard/zeroout for each
1961 * contiguous region
1962 */
1963 log_offset = be32_to_cpu(journal->j_superblock->s_first);
1964 block_start = ~0ULL;
1965 for (block = log_offset; block < journal->j_total_len; block++) {
1966 err = jbd2_journal_bmap(journal, block, &phys_block);
1967 if (err) {
1968 pr_err("JBD2: bad block at offset %lu", block);
1969 return err;
1970 }
1971
1972 if (block_start == ~0ULL) {
1973 block_start = phys_block;
1974 block_stop = block_start - 1;
1975 }
1976
1977 /*
1978 * last block not contiguous with current block,
1979 * process last contiguous region and return to this block on
1980 * next loop
1981 */
1982 if (phys_block != block_stop + 1) {
1983 block--;
1984 } else {
1985 block_stop++;
1986 /*
1987 * if this isn't the last block of journal,
1988 * no need to process now because next block may also
1989 * be part of this contiguous region
1990 */
1991 if (block != journal->j_total_len - 1)
1992 continue;
1993 }
1994
1995 /*
1996 * end of contiguous region or this is last block of journal,
1997 * take care of the region
1998 */
1999 byte_start = block_start * journal->j_blocksize;
2000 byte_stop = block_stop * journal->j_blocksize;
2001 byte_count = (block_stop - block_start + 1) *
2002 journal->j_blocksize;
2003
2004 truncate_inode_pages_range(journal->j_dev->bd_inode->i_mapping,
2005 byte_start, byte_stop);
2006
2007 if (flags & JBD2_JOURNAL_FLUSH_DISCARD) {
2008 err = blkdev_issue_discard(journal->j_dev,
2009 byte_start >> SECTOR_SHIFT,
2010 byte_count >> SECTOR_SHIFT,
2011 GFP_NOFS);
2012 } else if (flags & JBD2_JOURNAL_FLUSH_ZEROOUT) {
2013 err = blkdev_issue_zeroout(journal->j_dev,
2014 byte_start >> SECTOR_SHIFT,
2015 byte_count >> SECTOR_SHIFT,
2016 GFP_NOFS, 0);
2017 }
2018
2019 if (unlikely(err != 0)) {
2020 pr_err("JBD2: (error %d) unable to wipe journal at physical blocks %llu - %llu",
2021 err, block_start, block_stop);
2022 return err;
2023 }
2024
2025 /* reset start and stop after processing a region */
2026 block_start = ~0ULL;
2027 }
2028
2029 return blkdev_issue_flush(journal->j_dev);
2030 }
2031
2032 /**
2033 * jbd2_journal_update_sb_errno() - Update error in the journal.
2034 * @journal: The journal to update.
2035 *
2036 * Update a journal's errno. Write updated superblock to disk waiting for IO
2037 * to complete.
2038 */
jbd2_journal_update_sb_errno(journal_t * journal)2039 void jbd2_journal_update_sb_errno(journal_t *journal)
2040 {
2041 journal_superblock_t *sb = journal->j_superblock;
2042 int errcode;
2043
2044 lock_buffer(journal->j_sb_buffer);
2045 errcode = journal->j_errno;
2046 if (errcode == -ESHUTDOWN)
2047 errcode = 0;
2048 jbd2_debug(1, "JBD2: updating superblock error (errno %d)\n", errcode);
2049 sb->s_errno = cpu_to_be32(errcode);
2050
2051 jbd2_write_superblock(journal, REQ_FUA);
2052 }
2053 EXPORT_SYMBOL(jbd2_journal_update_sb_errno);
2054
2055 /**
2056 * jbd2_journal_load() - Read journal from disk.
2057 * @journal: Journal to act on.
2058 *
2059 * Given a journal_t structure which tells us which disk blocks contain
2060 * a journal, read the journal from disk to initialise the in-memory
2061 * structures.
2062 */
jbd2_journal_load(journal_t * journal)2063 int jbd2_journal_load(journal_t *journal)
2064 {
2065 int err;
2066 journal_superblock_t *sb = journal->j_superblock;
2067
2068 /*
2069 * Create a slab for this blocksize
2070 */
2071 err = jbd2_journal_create_slab(be32_to_cpu(sb->s_blocksize));
2072 if (err)
2073 return err;
2074
2075 /* Let the recovery code check whether it needs to recover any
2076 * data from the journal. */
2077 err = jbd2_journal_recover(journal);
2078 if (err) {
2079 pr_warn("JBD2: journal recovery failed\n");
2080 return err;
2081 }
2082
2083 if (journal->j_failed_commit) {
2084 printk(KERN_ERR "JBD2: journal transaction %u on %s "
2085 "is corrupt.\n", journal->j_failed_commit,
2086 journal->j_devname);
2087 return -EFSCORRUPTED;
2088 }
2089 /*
2090 * clear JBD2_ABORT flag initialized in journal_init_common
2091 * here to update log tail information with the newest seq.
2092 */
2093 journal->j_flags &= ~JBD2_ABORT;
2094
2095 /* OK, we've finished with the dynamic journal bits:
2096 * reinitialise the dynamic contents of the superblock in memory
2097 * and reset them on disk. */
2098 err = journal_reset(journal);
2099 if (err) {
2100 pr_warn("JBD2: journal reset failed\n");
2101 return err;
2102 }
2103
2104 journal->j_flags |= JBD2_LOADED;
2105 return 0;
2106 }
2107
2108 /**
2109 * jbd2_journal_destroy() - Release a journal_t structure.
2110 * @journal: Journal to act on.
2111 *
2112 * Release a journal_t structure once it is no longer in use by the
2113 * journaled object.
2114 * Return <0 if we couldn't clean up the journal.
2115 */
jbd2_journal_destroy(journal_t * journal)2116 int jbd2_journal_destroy(journal_t *journal)
2117 {
2118 int err = 0;
2119
2120 /* Wait for the commit thread to wake up and die. */
2121 journal_kill_thread(journal);
2122
2123 /* Force a final log commit */
2124 if (journal->j_running_transaction)
2125 jbd2_journal_commit_transaction(journal);
2126
2127 /* Force any old transactions to disk */
2128
2129 /* Totally anal locking here... */
2130 spin_lock(&journal->j_list_lock);
2131 while (journal->j_checkpoint_transactions != NULL) {
2132 spin_unlock(&journal->j_list_lock);
2133 mutex_lock_io(&journal->j_checkpoint_mutex);
2134 err = jbd2_log_do_checkpoint(journal);
2135 mutex_unlock(&journal->j_checkpoint_mutex);
2136 /*
2137 * If checkpointing failed, just free the buffers to avoid
2138 * looping forever
2139 */
2140 if (err) {
2141 jbd2_journal_destroy_checkpoint(journal);
2142 spin_lock(&journal->j_list_lock);
2143 break;
2144 }
2145 spin_lock(&journal->j_list_lock);
2146 }
2147
2148 J_ASSERT(journal->j_running_transaction == NULL);
2149 J_ASSERT(journal->j_committing_transaction == NULL);
2150 J_ASSERT(journal->j_checkpoint_transactions == NULL);
2151 spin_unlock(&journal->j_list_lock);
2152
2153 /*
2154 * OK, all checkpoint transactions have been checked, now check the
2155 * write out io error flag and abort the journal if some buffer failed
2156 * to write back to the original location, otherwise the filesystem
2157 * may become inconsistent.
2158 */
2159 if (!is_journal_aborted(journal) &&
2160 test_bit(JBD2_CHECKPOINT_IO_ERROR, &journal->j_atomic_flags))
2161 jbd2_journal_abort(journal, -EIO);
2162
2163 if (journal->j_sb_buffer) {
2164 if (!is_journal_aborted(journal)) {
2165 mutex_lock_io(&journal->j_checkpoint_mutex);
2166
2167 write_lock(&journal->j_state_lock);
2168 journal->j_tail_sequence =
2169 ++journal->j_transaction_sequence;
2170 write_unlock(&journal->j_state_lock);
2171
2172 jbd2_mark_journal_empty(journal, REQ_PREFLUSH | REQ_FUA);
2173 mutex_unlock(&journal->j_checkpoint_mutex);
2174 } else
2175 err = -EIO;
2176 brelse(journal->j_sb_buffer);
2177 }
2178
2179 if (journal->j_shrinker.flags & SHRINKER_REGISTERED) {
2180 percpu_counter_destroy(&journal->j_checkpoint_jh_count);
2181 unregister_shrinker(&journal->j_shrinker);
2182 }
2183 if (journal->j_proc_entry)
2184 jbd2_stats_proc_exit(journal);
2185 iput(journal->j_inode);
2186 if (journal->j_revoke)
2187 jbd2_journal_destroy_revoke(journal);
2188 if (journal->j_chksum_driver)
2189 crypto_free_shash(journal->j_chksum_driver);
2190 kfree(journal->j_fc_wbuf);
2191 kfree(journal->j_wbuf);
2192 kfree(journal);
2193
2194 return err;
2195 }
2196
2197
2198 /**
2199 * jbd2_journal_check_used_features() - Check if features specified are used.
2200 * @journal: Journal to check.
2201 * @compat: bitmask of compatible features
2202 * @ro: bitmask of features that force read-only mount
2203 * @incompat: bitmask of incompatible features
2204 *
2205 * Check whether the journal uses all of a given set of
2206 * features. Return true (non-zero) if it does.
2207 **/
2208
jbd2_journal_check_used_features(journal_t * journal,unsigned long compat,unsigned long ro,unsigned long incompat)2209 int jbd2_journal_check_used_features(journal_t *journal, unsigned long compat,
2210 unsigned long ro, unsigned long incompat)
2211 {
2212 journal_superblock_t *sb;
2213
2214 if (!compat && !ro && !incompat)
2215 return 1;
2216 if (!jbd2_format_support_feature(journal))
2217 return 0;
2218
2219 sb = journal->j_superblock;
2220
2221 if (((be32_to_cpu(sb->s_feature_compat) & compat) == compat) &&
2222 ((be32_to_cpu(sb->s_feature_ro_compat) & ro) == ro) &&
2223 ((be32_to_cpu(sb->s_feature_incompat) & incompat) == incompat))
2224 return 1;
2225
2226 return 0;
2227 }
2228
2229 /**
2230 * jbd2_journal_check_available_features() - Check feature set in journalling layer
2231 * @journal: Journal to check.
2232 * @compat: bitmask of compatible features
2233 * @ro: bitmask of features that force read-only mount
2234 * @incompat: bitmask of incompatible features
2235 *
2236 * Check whether the journaling code supports the use of
2237 * all of a given set of features on this journal. Return true
2238 * (non-zero) if it can. */
2239
jbd2_journal_check_available_features(journal_t * journal,unsigned long compat,unsigned long ro,unsigned long incompat)2240 int jbd2_journal_check_available_features(journal_t *journal, unsigned long compat,
2241 unsigned long ro, unsigned long incompat)
2242 {
2243 if (!compat && !ro && !incompat)
2244 return 1;
2245
2246 if (!jbd2_format_support_feature(journal))
2247 return 0;
2248
2249 if ((compat & JBD2_KNOWN_COMPAT_FEATURES) == compat &&
2250 (ro & JBD2_KNOWN_ROCOMPAT_FEATURES) == ro &&
2251 (incompat & JBD2_KNOWN_INCOMPAT_FEATURES) == incompat)
2252 return 1;
2253
2254 return 0;
2255 }
2256
2257 static int
jbd2_journal_initialize_fast_commit(journal_t * journal)2258 jbd2_journal_initialize_fast_commit(journal_t *journal)
2259 {
2260 journal_superblock_t *sb = journal->j_superblock;
2261 unsigned long long num_fc_blks;
2262
2263 num_fc_blks = jbd2_journal_get_num_fc_blks(sb);
2264 if (journal->j_last - num_fc_blks < JBD2_MIN_JOURNAL_BLOCKS)
2265 return -ENOSPC;
2266
2267 /* Are we called twice? */
2268 WARN_ON(journal->j_fc_wbuf != NULL);
2269 journal->j_fc_wbuf = kmalloc_array(num_fc_blks,
2270 sizeof(struct buffer_head *), GFP_KERNEL);
2271 if (!journal->j_fc_wbuf)
2272 return -ENOMEM;
2273
2274 journal->j_fc_wbufsize = num_fc_blks;
2275 journal->j_fc_last = journal->j_last;
2276 journal->j_last = journal->j_fc_last - num_fc_blks;
2277 journal->j_fc_first = journal->j_last + 1;
2278 journal->j_fc_off = 0;
2279 journal->j_free = journal->j_last - journal->j_first;
2280 journal->j_max_transaction_buffers =
2281 jbd2_journal_get_max_txn_bufs(journal);
2282
2283 return 0;
2284 }
2285
2286 /**
2287 * jbd2_journal_set_features() - Mark a given journal feature in the superblock
2288 * @journal: Journal to act on.
2289 * @compat: bitmask of compatible features
2290 * @ro: bitmask of features that force read-only mount
2291 * @incompat: bitmask of incompatible features
2292 *
2293 * Mark a given journal feature as present on the
2294 * superblock. Returns true if the requested features could be set.
2295 *
2296 */
2297
jbd2_journal_set_features(journal_t * journal,unsigned long compat,unsigned long ro,unsigned long incompat)2298 int jbd2_journal_set_features(journal_t *journal, unsigned long compat,
2299 unsigned long ro, unsigned long incompat)
2300 {
2301 #define INCOMPAT_FEATURE_ON(f) \
2302 ((incompat & (f)) && !(sb->s_feature_incompat & cpu_to_be32(f)))
2303 #define COMPAT_FEATURE_ON(f) \
2304 ((compat & (f)) && !(sb->s_feature_compat & cpu_to_be32(f)))
2305 journal_superblock_t *sb;
2306
2307 if (jbd2_journal_check_used_features(journal, compat, ro, incompat))
2308 return 1;
2309
2310 if (!jbd2_journal_check_available_features(journal, compat, ro, incompat))
2311 return 0;
2312
2313 /* If enabling v2 checksums, turn on v3 instead */
2314 if (incompat & JBD2_FEATURE_INCOMPAT_CSUM_V2) {
2315 incompat &= ~JBD2_FEATURE_INCOMPAT_CSUM_V2;
2316 incompat |= JBD2_FEATURE_INCOMPAT_CSUM_V3;
2317 }
2318
2319 /* Asking for checksumming v3 and v1? Only give them v3. */
2320 if (incompat & JBD2_FEATURE_INCOMPAT_CSUM_V3 &&
2321 compat & JBD2_FEATURE_COMPAT_CHECKSUM)
2322 compat &= ~JBD2_FEATURE_COMPAT_CHECKSUM;
2323
2324 jbd2_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n",
2325 compat, ro, incompat);
2326
2327 sb = journal->j_superblock;
2328
2329 if (incompat & JBD2_FEATURE_INCOMPAT_FAST_COMMIT) {
2330 if (jbd2_journal_initialize_fast_commit(journal)) {
2331 pr_err("JBD2: Cannot enable fast commits.\n");
2332 return 0;
2333 }
2334 }
2335
2336 /* Load the checksum driver if necessary */
2337 if ((journal->j_chksum_driver == NULL) &&
2338 INCOMPAT_FEATURE_ON(JBD2_FEATURE_INCOMPAT_CSUM_V3)) {
2339 journal->j_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
2340 if (IS_ERR(journal->j_chksum_driver)) {
2341 printk(KERN_ERR "JBD2: Cannot load crc32c driver.\n");
2342 journal->j_chksum_driver = NULL;
2343 return 0;
2344 }
2345 /* Precompute checksum seed for all metadata */
2346 journal->j_csum_seed = jbd2_chksum(journal, ~0, sb->s_uuid,
2347 sizeof(sb->s_uuid));
2348 }
2349
2350 lock_buffer(journal->j_sb_buffer);
2351
2352 /* If enabling v3 checksums, update superblock */
2353 if (INCOMPAT_FEATURE_ON(JBD2_FEATURE_INCOMPAT_CSUM_V3)) {
2354 sb->s_checksum_type = JBD2_CRC32C_CHKSUM;
2355 sb->s_feature_compat &=
2356 ~cpu_to_be32(JBD2_FEATURE_COMPAT_CHECKSUM);
2357 }
2358
2359 /* If enabling v1 checksums, downgrade superblock */
2360 if (COMPAT_FEATURE_ON(JBD2_FEATURE_COMPAT_CHECKSUM))
2361 sb->s_feature_incompat &=
2362 ~cpu_to_be32(JBD2_FEATURE_INCOMPAT_CSUM_V2 |
2363 JBD2_FEATURE_INCOMPAT_CSUM_V3);
2364
2365 sb->s_feature_compat |= cpu_to_be32(compat);
2366 sb->s_feature_ro_compat |= cpu_to_be32(ro);
2367 sb->s_feature_incompat |= cpu_to_be32(incompat);
2368 unlock_buffer(journal->j_sb_buffer);
2369 journal->j_revoke_records_per_block =
2370 journal_revoke_records_per_block(journal);
2371
2372 return 1;
2373 #undef COMPAT_FEATURE_ON
2374 #undef INCOMPAT_FEATURE_ON
2375 }
2376
2377 /*
2378 * jbd2_journal_clear_features() - Clear a given journal feature in the
2379 * superblock
2380 * @journal: Journal to act on.
2381 * @compat: bitmask of compatible features
2382 * @ro: bitmask of features that force read-only mount
2383 * @incompat: bitmask of incompatible features
2384 *
2385 * Clear a given journal feature as present on the
2386 * superblock.
2387 */
jbd2_journal_clear_features(journal_t * journal,unsigned long compat,unsigned long ro,unsigned long incompat)2388 void jbd2_journal_clear_features(journal_t *journal, unsigned long compat,
2389 unsigned long ro, unsigned long incompat)
2390 {
2391 journal_superblock_t *sb;
2392
2393 jbd2_debug(1, "Clear features 0x%lx/0x%lx/0x%lx\n",
2394 compat, ro, incompat);
2395
2396 sb = journal->j_superblock;
2397
2398 sb->s_feature_compat &= ~cpu_to_be32(compat);
2399 sb->s_feature_ro_compat &= ~cpu_to_be32(ro);
2400 sb->s_feature_incompat &= ~cpu_to_be32(incompat);
2401 journal->j_revoke_records_per_block =
2402 journal_revoke_records_per_block(journal);
2403 }
2404 EXPORT_SYMBOL(jbd2_journal_clear_features);
2405
2406 /**
2407 * jbd2_journal_flush() - Flush journal
2408 * @journal: Journal to act on.
2409 * @flags: optional operation on the journal blocks after the flush (see below)
2410 *
2411 * Flush all data for a given journal to disk and empty the journal.
2412 * Filesystems can use this when remounting readonly to ensure that
2413 * recovery does not need to happen on remount. Optionally, a discard or zeroout
2414 * can be issued on the journal blocks after flushing.
2415 *
2416 * flags:
2417 * JBD2_JOURNAL_FLUSH_DISCARD: issues discards for the journal blocks
2418 * JBD2_JOURNAL_FLUSH_ZEROOUT: issues zeroouts for the journal blocks
2419 */
jbd2_journal_flush(journal_t * journal,unsigned int flags)2420 int jbd2_journal_flush(journal_t *journal, unsigned int flags)
2421 {
2422 int err = 0;
2423 transaction_t *transaction = NULL;
2424
2425 write_lock(&journal->j_state_lock);
2426
2427 /* Force everything buffered to the log... */
2428 if (journal->j_running_transaction) {
2429 transaction = journal->j_running_transaction;
2430 __jbd2_log_start_commit(journal, transaction->t_tid);
2431 } else if (journal->j_committing_transaction)
2432 transaction = journal->j_committing_transaction;
2433
2434 /* Wait for the log commit to complete... */
2435 if (transaction) {
2436 tid_t tid = transaction->t_tid;
2437
2438 write_unlock(&journal->j_state_lock);
2439 jbd2_log_wait_commit(journal, tid);
2440 } else {
2441 write_unlock(&journal->j_state_lock);
2442 }
2443
2444 /* ...and flush everything in the log out to disk. */
2445 spin_lock(&journal->j_list_lock);
2446 while (!err && journal->j_checkpoint_transactions != NULL) {
2447 spin_unlock(&journal->j_list_lock);
2448 mutex_lock_io(&journal->j_checkpoint_mutex);
2449 err = jbd2_log_do_checkpoint(journal);
2450 mutex_unlock(&journal->j_checkpoint_mutex);
2451 spin_lock(&journal->j_list_lock);
2452 }
2453 spin_unlock(&journal->j_list_lock);
2454
2455 if (is_journal_aborted(journal))
2456 return -EIO;
2457
2458 mutex_lock_io(&journal->j_checkpoint_mutex);
2459 if (!err) {
2460 err = jbd2_cleanup_journal_tail(journal);
2461 if (err < 0) {
2462 mutex_unlock(&journal->j_checkpoint_mutex);
2463 goto out;
2464 }
2465 err = 0;
2466 }
2467
2468 /* Finally, mark the journal as really needing no recovery.
2469 * This sets s_start==0 in the underlying superblock, which is
2470 * the magic code for a fully-recovered superblock. Any future
2471 * commits of data to the journal will restore the current
2472 * s_start value. */
2473 jbd2_mark_journal_empty(journal, REQ_FUA);
2474
2475 if (flags)
2476 err = __jbd2_journal_erase(journal, flags);
2477
2478 mutex_unlock(&journal->j_checkpoint_mutex);
2479 write_lock(&journal->j_state_lock);
2480 J_ASSERT(!journal->j_running_transaction);
2481 J_ASSERT(!journal->j_committing_transaction);
2482 J_ASSERT(!journal->j_checkpoint_transactions);
2483 J_ASSERT(journal->j_head == journal->j_tail);
2484 J_ASSERT(journal->j_tail_sequence == journal->j_transaction_sequence);
2485 write_unlock(&journal->j_state_lock);
2486 out:
2487 return err;
2488 }
2489
2490 /**
2491 * jbd2_journal_wipe() - Wipe journal contents
2492 * @journal: Journal to act on.
2493 * @write: flag (see below)
2494 *
2495 * Wipe out all of the contents of a journal, safely. This will produce
2496 * a warning if the journal contains any valid recovery information.
2497 * Must be called between journal_init_*() and jbd2_journal_load().
2498 *
2499 * If 'write' is non-zero, then we wipe out the journal on disk; otherwise
2500 * we merely suppress recovery.
2501 */
2502
jbd2_journal_wipe(journal_t * journal,int write)2503 int jbd2_journal_wipe(journal_t *journal, int write)
2504 {
2505 int err;
2506
2507 J_ASSERT (!(journal->j_flags & JBD2_LOADED));
2508
2509 if (!journal->j_tail)
2510 return 0;
2511
2512 printk(KERN_WARNING "JBD2: %s recovery information on journal\n",
2513 write ? "Clearing" : "Ignoring");
2514
2515 err = jbd2_journal_skip_recovery(journal);
2516 if (write) {
2517 /* Lock to make assertions happy... */
2518 mutex_lock_io(&journal->j_checkpoint_mutex);
2519 jbd2_mark_journal_empty(journal, REQ_FUA);
2520 mutex_unlock(&journal->j_checkpoint_mutex);
2521 }
2522
2523 return err;
2524 }
2525
2526 /**
2527 * jbd2_journal_abort () - Shutdown the journal immediately.
2528 * @journal: the journal to shutdown.
2529 * @errno: an error number to record in the journal indicating
2530 * the reason for the shutdown.
2531 *
2532 * Perform a complete, immediate shutdown of the ENTIRE
2533 * journal (not of a single transaction). This operation cannot be
2534 * undone without closing and reopening the journal.
2535 *
2536 * The jbd2_journal_abort function is intended to support higher level error
2537 * recovery mechanisms such as the ext2/ext3 remount-readonly error
2538 * mode.
2539 *
2540 * Journal abort has very specific semantics. Any existing dirty,
2541 * unjournaled buffers in the main filesystem will still be written to
2542 * disk by bdflush, but the journaling mechanism will be suspended
2543 * immediately and no further transaction commits will be honoured.
2544 *
2545 * Any dirty, journaled buffers will be written back to disk without
2546 * hitting the journal. Atomicity cannot be guaranteed on an aborted
2547 * filesystem, but we _do_ attempt to leave as much data as possible
2548 * behind for fsck to use for cleanup.
2549 *
2550 * Any attempt to get a new transaction handle on a journal which is in
2551 * ABORT state will just result in an -EROFS error return. A
2552 * jbd2_journal_stop on an existing handle will return -EIO if we have
2553 * entered abort state during the update.
2554 *
2555 * Recursive transactions are not disturbed by journal abort until the
2556 * final jbd2_journal_stop, which will receive the -EIO error.
2557 *
2558 * Finally, the jbd2_journal_abort call allows the caller to supply an errno
2559 * which will be recorded (if possible) in the journal superblock. This
2560 * allows a client to record failure conditions in the middle of a
2561 * transaction without having to complete the transaction to record the
2562 * failure to disk. ext3_error, for example, now uses this
2563 * functionality.
2564 *
2565 */
2566
jbd2_journal_abort(journal_t * journal,int errno)2567 void jbd2_journal_abort(journal_t *journal, int errno)
2568 {
2569 transaction_t *transaction;
2570
2571 /*
2572 * Lock the aborting procedure until everything is done, this avoid
2573 * races between filesystem's error handling flow (e.g. ext4_abort()),
2574 * ensure panic after the error info is written into journal's
2575 * superblock.
2576 */
2577 mutex_lock(&journal->j_abort_mutex);
2578 /*
2579 * ESHUTDOWN always takes precedence because a file system check
2580 * caused by any other journal abort error is not required after
2581 * a shutdown triggered.
2582 */
2583 write_lock(&journal->j_state_lock);
2584 if (journal->j_flags & JBD2_ABORT) {
2585 int old_errno = journal->j_errno;
2586
2587 write_unlock(&journal->j_state_lock);
2588 if (old_errno != -ESHUTDOWN && errno == -ESHUTDOWN) {
2589 journal->j_errno = errno;
2590 jbd2_journal_update_sb_errno(journal);
2591 }
2592 mutex_unlock(&journal->j_abort_mutex);
2593 return;
2594 }
2595
2596 /*
2597 * Mark the abort as occurred and start current running transaction
2598 * to release all journaled buffer.
2599 */
2600 pr_err("Aborting journal on device %s.\n", journal->j_devname);
2601
2602 journal->j_flags |= JBD2_ABORT;
2603 journal->j_errno = errno;
2604 transaction = journal->j_running_transaction;
2605 if (transaction)
2606 __jbd2_log_start_commit(journal, transaction->t_tid);
2607 write_unlock(&journal->j_state_lock);
2608
2609 /*
2610 * Record errno to the journal super block, so that fsck and jbd2
2611 * layer could realise that a filesystem check is needed.
2612 */
2613 jbd2_journal_update_sb_errno(journal);
2614 mutex_unlock(&journal->j_abort_mutex);
2615 }
2616
2617 /**
2618 * jbd2_journal_errno() - returns the journal's error state.
2619 * @journal: journal to examine.
2620 *
2621 * This is the errno number set with jbd2_journal_abort(), the last
2622 * time the journal was mounted - if the journal was stopped
2623 * without calling abort this will be 0.
2624 *
2625 * If the journal has been aborted on this mount time -EROFS will
2626 * be returned.
2627 */
jbd2_journal_errno(journal_t * journal)2628 int jbd2_journal_errno(journal_t *journal)
2629 {
2630 int err;
2631
2632 read_lock(&journal->j_state_lock);
2633 if (journal->j_flags & JBD2_ABORT)
2634 err = -EROFS;
2635 else
2636 err = journal->j_errno;
2637 read_unlock(&journal->j_state_lock);
2638 return err;
2639 }
2640
2641 /**
2642 * jbd2_journal_clear_err() - clears the journal's error state
2643 * @journal: journal to act on.
2644 *
2645 * An error must be cleared or acked to take a FS out of readonly
2646 * mode.
2647 */
jbd2_journal_clear_err(journal_t * journal)2648 int jbd2_journal_clear_err(journal_t *journal)
2649 {
2650 int err = 0;
2651
2652 write_lock(&journal->j_state_lock);
2653 if (journal->j_flags & JBD2_ABORT)
2654 err = -EROFS;
2655 else
2656 journal->j_errno = 0;
2657 write_unlock(&journal->j_state_lock);
2658 return err;
2659 }
2660
2661 /**
2662 * jbd2_journal_ack_err() - Ack journal err.
2663 * @journal: journal to act on.
2664 *
2665 * An error must be cleared or acked to take a FS out of readonly
2666 * mode.
2667 */
jbd2_journal_ack_err(journal_t * journal)2668 void jbd2_journal_ack_err(journal_t *journal)
2669 {
2670 write_lock(&journal->j_state_lock);
2671 if (journal->j_errno)
2672 journal->j_flags |= JBD2_ACK_ERR;
2673 write_unlock(&journal->j_state_lock);
2674 }
2675
jbd2_journal_blocks_per_page(struct inode * inode)2676 int jbd2_journal_blocks_per_page(struct inode *inode)
2677 {
2678 return 1 << (PAGE_SHIFT - inode->i_sb->s_blocksize_bits);
2679 }
2680
2681 /*
2682 * helper functions to deal with 32 or 64bit block numbers.
2683 */
journal_tag_bytes(journal_t * journal)2684 size_t journal_tag_bytes(journal_t *journal)
2685 {
2686 size_t sz;
2687
2688 if (jbd2_has_feature_csum3(journal))
2689 return sizeof(journal_block_tag3_t);
2690
2691 sz = sizeof(journal_block_tag_t);
2692
2693 if (jbd2_has_feature_csum2(journal))
2694 sz += sizeof(__u16);
2695
2696 if (jbd2_has_feature_64bit(journal))
2697 return sz;
2698 else
2699 return sz - sizeof(__u32);
2700 }
2701
2702 /*
2703 * JBD memory management
2704 *
2705 * These functions are used to allocate block-sized chunks of memory
2706 * used for making copies of buffer_head data. Very often it will be
2707 * page-sized chunks of data, but sometimes it will be in
2708 * sub-page-size chunks. (For example, 16k pages on Power systems
2709 * with a 4k block file system.) For blocks smaller than a page, we
2710 * use a SLAB allocator. There are slab caches for each block size,
2711 * which are allocated at mount time, if necessary, and we only free
2712 * (all of) the slab caches when/if the jbd2 module is unloaded. For
2713 * this reason we don't need to a mutex to protect access to
2714 * jbd2_slab[] allocating or releasing memory; only in
2715 * jbd2_journal_create_slab().
2716 */
2717 #define JBD2_MAX_SLABS 8
2718 static struct kmem_cache *jbd2_slab[JBD2_MAX_SLABS];
2719
2720 static const char *jbd2_slab_names[JBD2_MAX_SLABS] = {
2721 "jbd2_1k", "jbd2_2k", "jbd2_4k", "jbd2_8k",
2722 "jbd2_16k", "jbd2_32k", "jbd2_64k", "jbd2_128k"
2723 };
2724
2725
jbd2_journal_destroy_slabs(void)2726 static void jbd2_journal_destroy_slabs(void)
2727 {
2728 int i;
2729
2730 for (i = 0; i < JBD2_MAX_SLABS; i++) {
2731 kmem_cache_destroy(jbd2_slab[i]);
2732 jbd2_slab[i] = NULL;
2733 }
2734 }
2735
jbd2_journal_create_slab(size_t size)2736 static int jbd2_journal_create_slab(size_t size)
2737 {
2738 static DEFINE_MUTEX(jbd2_slab_create_mutex);
2739 int i = order_base_2(size) - 10;
2740 size_t slab_size;
2741
2742 if (size == PAGE_SIZE)
2743 return 0;
2744
2745 if (i >= JBD2_MAX_SLABS)
2746 return -EINVAL;
2747
2748 if (unlikely(i < 0))
2749 i = 0;
2750 mutex_lock(&jbd2_slab_create_mutex);
2751 if (jbd2_slab[i]) {
2752 mutex_unlock(&jbd2_slab_create_mutex);
2753 return 0; /* Already created */
2754 }
2755
2756 slab_size = 1 << (i+10);
2757 jbd2_slab[i] = kmem_cache_create(jbd2_slab_names[i], slab_size,
2758 slab_size, 0, NULL);
2759 mutex_unlock(&jbd2_slab_create_mutex);
2760 if (!jbd2_slab[i]) {
2761 printk(KERN_EMERG "JBD2: no memory for jbd2_slab cache\n");
2762 return -ENOMEM;
2763 }
2764 return 0;
2765 }
2766
get_slab(size_t size)2767 static struct kmem_cache *get_slab(size_t size)
2768 {
2769 int i = order_base_2(size) - 10;
2770
2771 BUG_ON(i >= JBD2_MAX_SLABS);
2772 if (unlikely(i < 0))
2773 i = 0;
2774 BUG_ON(jbd2_slab[i] == NULL);
2775 return jbd2_slab[i];
2776 }
2777
jbd2_alloc(size_t size,gfp_t flags)2778 void *jbd2_alloc(size_t size, gfp_t flags)
2779 {
2780 void *ptr;
2781
2782 BUG_ON(size & (size-1)); /* Must be a power of 2 */
2783
2784 if (size < PAGE_SIZE)
2785 ptr = kmem_cache_alloc(get_slab(size), flags);
2786 else
2787 ptr = (void *)__get_free_pages(flags, get_order(size));
2788
2789 /* Check alignment; SLUB has gotten this wrong in the past,
2790 * and this can lead to user data corruption! */
2791 BUG_ON(((unsigned long) ptr) & (size-1));
2792
2793 return ptr;
2794 }
2795
jbd2_free(void * ptr,size_t size)2796 void jbd2_free(void *ptr, size_t size)
2797 {
2798 if (size < PAGE_SIZE)
2799 kmem_cache_free(get_slab(size), ptr);
2800 else
2801 free_pages((unsigned long)ptr, get_order(size));
2802 };
2803
2804 /*
2805 * Journal_head storage management
2806 */
2807 static struct kmem_cache *jbd2_journal_head_cache;
2808 #ifdef CONFIG_JBD2_DEBUG
2809 static atomic_t nr_journal_heads = ATOMIC_INIT(0);
2810 #endif
2811
jbd2_journal_init_journal_head_cache(void)2812 static int __init jbd2_journal_init_journal_head_cache(void)
2813 {
2814 J_ASSERT(!jbd2_journal_head_cache);
2815 jbd2_journal_head_cache = kmem_cache_create("jbd2_journal_head",
2816 sizeof(struct journal_head),
2817 0, /* offset */
2818 SLAB_TEMPORARY | SLAB_TYPESAFE_BY_RCU,
2819 NULL); /* ctor */
2820 if (!jbd2_journal_head_cache) {
2821 printk(KERN_EMERG "JBD2: no memory for journal_head cache\n");
2822 return -ENOMEM;
2823 }
2824 return 0;
2825 }
2826
jbd2_journal_destroy_journal_head_cache(void)2827 static void jbd2_journal_destroy_journal_head_cache(void)
2828 {
2829 kmem_cache_destroy(jbd2_journal_head_cache);
2830 jbd2_journal_head_cache = NULL;
2831 }
2832
2833 /*
2834 * journal_head splicing and dicing
2835 */
journal_alloc_journal_head(void)2836 static struct journal_head *journal_alloc_journal_head(void)
2837 {
2838 struct journal_head *ret;
2839
2840 #ifdef CONFIG_JBD2_DEBUG
2841 atomic_inc(&nr_journal_heads);
2842 #endif
2843 ret = kmem_cache_zalloc(jbd2_journal_head_cache, GFP_NOFS);
2844 if (!ret) {
2845 jbd2_debug(1, "out of memory for journal_head\n");
2846 pr_notice_ratelimited("ENOMEM in %s, retrying.\n", __func__);
2847 ret = kmem_cache_zalloc(jbd2_journal_head_cache,
2848 GFP_NOFS | __GFP_NOFAIL);
2849 }
2850 if (ret)
2851 spin_lock_init(&ret->b_state_lock);
2852 return ret;
2853 }
2854
journal_free_journal_head(struct journal_head * jh)2855 static void journal_free_journal_head(struct journal_head *jh)
2856 {
2857 #ifdef CONFIG_JBD2_DEBUG
2858 atomic_dec(&nr_journal_heads);
2859 memset(jh, JBD2_POISON_FREE, sizeof(*jh));
2860 #endif
2861 kmem_cache_free(jbd2_journal_head_cache, jh);
2862 }
2863
2864 /*
2865 * A journal_head is attached to a buffer_head whenever JBD has an
2866 * interest in the buffer.
2867 *
2868 * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit
2869 * is set. This bit is tested in core kernel code where we need to take
2870 * JBD-specific actions. Testing the zeroness of ->b_private is not reliable
2871 * there.
2872 *
2873 * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one.
2874 *
2875 * When a buffer has its BH_JBD bit set it is immune from being released by
2876 * core kernel code, mainly via ->b_count.
2877 *
2878 * A journal_head is detached from its buffer_head when the journal_head's
2879 * b_jcount reaches zero. Running transaction (b_transaction) and checkpoint
2880 * transaction (b_cp_transaction) hold their references to b_jcount.
2881 *
2882 * Various places in the kernel want to attach a journal_head to a buffer_head
2883 * _before_ attaching the journal_head to a transaction. To protect the
2884 * journal_head in this situation, jbd2_journal_add_journal_head elevates the
2885 * journal_head's b_jcount refcount by one. The caller must call
2886 * jbd2_journal_put_journal_head() to undo this.
2887 *
2888 * So the typical usage would be:
2889 *
2890 * (Attach a journal_head if needed. Increments b_jcount)
2891 * struct journal_head *jh = jbd2_journal_add_journal_head(bh);
2892 * ...
2893 * (Get another reference for transaction)
2894 * jbd2_journal_grab_journal_head(bh);
2895 * jh->b_transaction = xxx;
2896 * (Put original reference)
2897 * jbd2_journal_put_journal_head(jh);
2898 */
2899
2900 /*
2901 * Give a buffer_head a journal_head.
2902 *
2903 * May sleep.
2904 */
jbd2_journal_add_journal_head(struct buffer_head * bh)2905 struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh)
2906 {
2907 struct journal_head *jh;
2908 struct journal_head *new_jh = NULL;
2909
2910 repeat:
2911 if (!buffer_jbd(bh))
2912 new_jh = journal_alloc_journal_head();
2913
2914 jbd_lock_bh_journal_head(bh);
2915 if (buffer_jbd(bh)) {
2916 jh = bh2jh(bh);
2917 } else {
2918 J_ASSERT_BH(bh,
2919 (atomic_read(&bh->b_count) > 0) ||
2920 (bh->b_folio && bh->b_folio->mapping));
2921
2922 if (!new_jh) {
2923 jbd_unlock_bh_journal_head(bh);
2924 goto repeat;
2925 }
2926
2927 jh = new_jh;
2928 new_jh = NULL; /* We consumed it */
2929 set_buffer_jbd(bh);
2930 bh->b_private = jh;
2931 jh->b_bh = bh;
2932 get_bh(bh);
2933 BUFFER_TRACE(bh, "added journal_head");
2934 }
2935 jh->b_jcount++;
2936 jbd_unlock_bh_journal_head(bh);
2937 if (new_jh)
2938 journal_free_journal_head(new_jh);
2939 return bh->b_private;
2940 }
2941
2942 /*
2943 * Grab a ref against this buffer_head's journal_head. If it ended up not
2944 * having a journal_head, return NULL
2945 */
jbd2_journal_grab_journal_head(struct buffer_head * bh)2946 struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh)
2947 {
2948 struct journal_head *jh = NULL;
2949
2950 jbd_lock_bh_journal_head(bh);
2951 if (buffer_jbd(bh)) {
2952 jh = bh2jh(bh);
2953 jh->b_jcount++;
2954 }
2955 jbd_unlock_bh_journal_head(bh);
2956 return jh;
2957 }
2958 EXPORT_SYMBOL(jbd2_journal_grab_journal_head);
2959
__journal_remove_journal_head(struct buffer_head * bh)2960 static void __journal_remove_journal_head(struct buffer_head *bh)
2961 {
2962 struct journal_head *jh = bh2jh(bh);
2963
2964 J_ASSERT_JH(jh, jh->b_transaction == NULL);
2965 J_ASSERT_JH(jh, jh->b_next_transaction == NULL);
2966 J_ASSERT_JH(jh, jh->b_cp_transaction == NULL);
2967 J_ASSERT_JH(jh, jh->b_jlist == BJ_None);
2968 J_ASSERT_BH(bh, buffer_jbd(bh));
2969 J_ASSERT_BH(bh, jh2bh(jh) == bh);
2970 BUFFER_TRACE(bh, "remove journal_head");
2971
2972 /* Unlink before dropping the lock */
2973 bh->b_private = NULL;
2974 jh->b_bh = NULL; /* debug, really */
2975 clear_buffer_jbd(bh);
2976 }
2977
journal_release_journal_head(struct journal_head * jh,size_t b_size)2978 static void journal_release_journal_head(struct journal_head *jh, size_t b_size)
2979 {
2980 if (jh->b_frozen_data) {
2981 printk(KERN_WARNING "%s: freeing b_frozen_data\n", __func__);
2982 jbd2_free(jh->b_frozen_data, b_size);
2983 }
2984 if (jh->b_committed_data) {
2985 printk(KERN_WARNING "%s: freeing b_committed_data\n", __func__);
2986 jbd2_free(jh->b_committed_data, b_size);
2987 }
2988 journal_free_journal_head(jh);
2989 }
2990
2991 /*
2992 * Drop a reference on the passed journal_head. If it fell to zero then
2993 * release the journal_head from the buffer_head.
2994 */
jbd2_journal_put_journal_head(struct journal_head * jh)2995 void jbd2_journal_put_journal_head(struct journal_head *jh)
2996 {
2997 struct buffer_head *bh = jh2bh(jh);
2998
2999 jbd_lock_bh_journal_head(bh);
3000 J_ASSERT_JH(jh, jh->b_jcount > 0);
3001 --jh->b_jcount;
3002 if (!jh->b_jcount) {
3003 __journal_remove_journal_head(bh);
3004 jbd_unlock_bh_journal_head(bh);
3005 journal_release_journal_head(jh, bh->b_size);
3006 __brelse(bh);
3007 } else {
3008 jbd_unlock_bh_journal_head(bh);
3009 }
3010 }
3011 EXPORT_SYMBOL(jbd2_journal_put_journal_head);
3012
3013 /*
3014 * Initialize jbd inode head
3015 */
jbd2_journal_init_jbd_inode(struct jbd2_inode * jinode,struct inode * inode)3016 void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode)
3017 {
3018 jinode->i_transaction = NULL;
3019 jinode->i_next_transaction = NULL;
3020 jinode->i_vfs_inode = inode;
3021 jinode->i_flags = 0;
3022 jinode->i_dirty_start = 0;
3023 jinode->i_dirty_end = 0;
3024 INIT_LIST_HEAD(&jinode->i_list);
3025 }
3026
3027 /*
3028 * Function to be called before we start removing inode from memory (i.e.,
3029 * clear_inode() is a fine place to be called from). It removes inode from
3030 * transaction's lists.
3031 */
jbd2_journal_release_jbd_inode(journal_t * journal,struct jbd2_inode * jinode)3032 void jbd2_journal_release_jbd_inode(journal_t *journal,
3033 struct jbd2_inode *jinode)
3034 {
3035 if (!journal)
3036 return;
3037 restart:
3038 spin_lock(&journal->j_list_lock);
3039 /* Is commit writing out inode - we have to wait */
3040 if (jinode->i_flags & JI_COMMIT_RUNNING) {
3041 wait_queue_head_t *wq;
3042 DEFINE_WAIT_BIT(wait, &jinode->i_flags, __JI_COMMIT_RUNNING);
3043 wq = bit_waitqueue(&jinode->i_flags, __JI_COMMIT_RUNNING);
3044 prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE);
3045 spin_unlock(&journal->j_list_lock);
3046 schedule();
3047 finish_wait(wq, &wait.wq_entry);
3048 goto restart;
3049 }
3050
3051 if (jinode->i_transaction) {
3052 list_del(&jinode->i_list);
3053 jinode->i_transaction = NULL;
3054 }
3055 spin_unlock(&journal->j_list_lock);
3056 }
3057
3058
3059 #ifdef CONFIG_PROC_FS
3060
3061 #define JBD2_STATS_PROC_NAME "fs/jbd2"
3062
jbd2_create_jbd_stats_proc_entry(void)3063 static void __init jbd2_create_jbd_stats_proc_entry(void)
3064 {
3065 proc_jbd2_stats = proc_mkdir(JBD2_STATS_PROC_NAME, NULL);
3066 }
3067
jbd2_remove_jbd_stats_proc_entry(void)3068 static void __exit jbd2_remove_jbd_stats_proc_entry(void)
3069 {
3070 if (proc_jbd2_stats)
3071 remove_proc_entry(JBD2_STATS_PROC_NAME, NULL);
3072 }
3073
3074 #else
3075
3076 #define jbd2_create_jbd_stats_proc_entry() do {} while (0)
3077 #define jbd2_remove_jbd_stats_proc_entry() do {} while (0)
3078
3079 #endif
3080
3081 struct kmem_cache *jbd2_handle_cache, *jbd2_inode_cache;
3082
jbd2_journal_init_inode_cache(void)3083 static int __init jbd2_journal_init_inode_cache(void)
3084 {
3085 J_ASSERT(!jbd2_inode_cache);
3086 jbd2_inode_cache = KMEM_CACHE(jbd2_inode, 0);
3087 if (!jbd2_inode_cache) {
3088 pr_emerg("JBD2: failed to create inode cache\n");
3089 return -ENOMEM;
3090 }
3091 return 0;
3092 }
3093
jbd2_journal_init_handle_cache(void)3094 static int __init jbd2_journal_init_handle_cache(void)
3095 {
3096 J_ASSERT(!jbd2_handle_cache);
3097 jbd2_handle_cache = KMEM_CACHE(jbd2_journal_handle, SLAB_TEMPORARY);
3098 if (!jbd2_handle_cache) {
3099 printk(KERN_EMERG "JBD2: failed to create handle cache\n");
3100 return -ENOMEM;
3101 }
3102 return 0;
3103 }
3104
jbd2_journal_destroy_inode_cache(void)3105 static void jbd2_journal_destroy_inode_cache(void)
3106 {
3107 kmem_cache_destroy(jbd2_inode_cache);
3108 jbd2_inode_cache = NULL;
3109 }
3110
jbd2_journal_destroy_handle_cache(void)3111 static void jbd2_journal_destroy_handle_cache(void)
3112 {
3113 kmem_cache_destroy(jbd2_handle_cache);
3114 jbd2_handle_cache = NULL;
3115 }
3116
3117 /*
3118 * Module startup and shutdown
3119 */
3120
journal_init_caches(void)3121 static int __init journal_init_caches(void)
3122 {
3123 int ret;
3124
3125 ret = jbd2_journal_init_revoke_record_cache();
3126 if (ret == 0)
3127 ret = jbd2_journal_init_revoke_table_cache();
3128 if (ret == 0)
3129 ret = jbd2_journal_init_journal_head_cache();
3130 if (ret == 0)
3131 ret = jbd2_journal_init_handle_cache();
3132 if (ret == 0)
3133 ret = jbd2_journal_init_inode_cache();
3134 if (ret == 0)
3135 ret = jbd2_journal_init_transaction_cache();
3136 return ret;
3137 }
3138
jbd2_journal_destroy_caches(void)3139 static void jbd2_journal_destroy_caches(void)
3140 {
3141 jbd2_journal_destroy_revoke_record_cache();
3142 jbd2_journal_destroy_revoke_table_cache();
3143 jbd2_journal_destroy_journal_head_cache();
3144 jbd2_journal_destroy_handle_cache();
3145 jbd2_journal_destroy_inode_cache();
3146 jbd2_journal_destroy_transaction_cache();
3147 jbd2_journal_destroy_slabs();
3148 }
3149
journal_init(void)3150 static int __init journal_init(void)
3151 {
3152 int ret;
3153
3154 BUILD_BUG_ON(sizeof(struct journal_superblock_s) != 1024);
3155
3156 ret = journal_init_caches();
3157 if (ret == 0) {
3158 jbd2_create_jbd_stats_proc_entry();
3159 } else {
3160 jbd2_journal_destroy_caches();
3161 }
3162 return ret;
3163 }
3164
journal_exit(void)3165 static void __exit journal_exit(void)
3166 {
3167 #ifdef CONFIG_JBD2_DEBUG
3168 int n = atomic_read(&nr_journal_heads);
3169 if (n)
3170 printk(KERN_ERR "JBD2: leaked %d journal_heads!\n", n);
3171 #endif
3172 jbd2_remove_jbd_stats_proc_entry();
3173 jbd2_journal_destroy_caches();
3174 }
3175
3176 MODULE_LICENSE("GPL");
3177 module_init(journal_init);
3178 module_exit(journal_exit);
3179
3180