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
224 prepare_to_wait(&journal->j_wait_commit, &wait,
225 TASK_INTERRUPTIBLE);
226 transaction = journal->j_running_transaction;
227 if (transaction == NULL ||
228 time_before(jiffies, transaction->t_expires)) {
229 write_unlock(&journal->j_state_lock);
230 schedule();
231 write_lock(&journal->j_state_lock);
232 }
233 finish_wait(&journal->j_wait_commit, &wait);
234 }
235
236 jbd2_debug(1, "kjournald2 wakes\n");
237
238 /*
239 * Were we woken up by a commit wakeup event?
240 */
241 transaction = journal->j_running_transaction;
242 if (transaction && time_after_eq(jiffies, transaction->t_expires)) {
243 journal->j_commit_request = transaction->t_tid;
244 jbd2_debug(1, "woke because of timeout\n");
245 }
246 goto loop;
247
248 end_loop:
249 del_timer_sync(&journal->j_commit_timer);
250 journal->j_task = NULL;
251 wake_up(&journal->j_wait_done_commit);
252 jbd2_debug(1, "Journal thread exiting.\n");
253 write_unlock(&journal->j_state_lock);
254 return 0;
255 }
256
jbd2_journal_start_thread(journal_t * journal)257 static int jbd2_journal_start_thread(journal_t *journal)
258 {
259 struct task_struct *t;
260
261 t = kthread_run(kjournald2, journal, "jbd2/%s",
262 journal->j_devname);
263 if (IS_ERR(t))
264 return PTR_ERR(t);
265
266 wait_event(journal->j_wait_done_commit, journal->j_task != NULL);
267 return 0;
268 }
269
journal_kill_thread(journal_t * journal)270 static void journal_kill_thread(journal_t *journal)
271 {
272 write_lock(&journal->j_state_lock);
273 journal->j_flags |= JBD2_UNMOUNT;
274
275 while (journal->j_task) {
276 write_unlock(&journal->j_state_lock);
277 wake_up(&journal->j_wait_commit);
278 wait_event(journal->j_wait_done_commit, journal->j_task == NULL);
279 write_lock(&journal->j_state_lock);
280 }
281 write_unlock(&journal->j_state_lock);
282 }
283
jbd2_data_needs_escaping(char * data)284 static inline bool jbd2_data_needs_escaping(char *data)
285 {
286 return *((__be32 *)data) == cpu_to_be32(JBD2_MAGIC_NUMBER);
287 }
288
jbd2_data_do_escape(char * data)289 static inline void jbd2_data_do_escape(char *data)
290 {
291 *((unsigned int *)data) = 0;
292 }
293
294 /*
295 * jbd2_journal_write_metadata_buffer: write a metadata buffer to the journal.
296 *
297 * Writes a metadata buffer to a given disk block. The actual IO is not
298 * performed but a new buffer_head is constructed which labels the data
299 * to be written with the correct destination disk block.
300 *
301 * Any magic-number escaping which needs to be done will cause a
302 * copy-out here. If the buffer happens to start with the
303 * JBD2_MAGIC_NUMBER, then we can't write it to the log directly: the
304 * magic number is only written to the log for descripter blocks. In
305 * this case, we copy the data and replace the first word with 0, and we
306 * return a result code which indicates that this buffer needs to be
307 * marked as an escaped buffer in the corresponding log descriptor
308 * block. The missing word can then be restored when the block is read
309 * during recovery.
310 *
311 * If the source buffer has already been modified by a new transaction
312 * since we took the last commit snapshot, we use the frozen copy of
313 * that data for IO. If we end up using the existing buffer_head's data
314 * for the write, then we have to make sure nobody modifies it while the
315 * IO is in progress. do_get_write_access() handles this.
316 *
317 * The function returns a pointer to the buffer_head to be used for IO.
318 *
319 *
320 * Return value:
321 * <0: Error
322 * =0: Finished OK without escape
323 * =1: Finished OK with escape
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 do_escape = 0;
332 struct buffer_head *new_bh;
333 struct folio *new_folio;
334 unsigned int new_offset;
335 struct buffer_head *bh_in = jh2bh(jh_in);
336 journal_t *journal = transaction->t_journal;
337
338 /*
339 * The buffer really shouldn't be locked: only the current committing
340 * transaction is allowed to write it, so nobody else is allowed
341 * to do any IO.
342 *
343 * akpm: except if we're journalling data, and write() output is
344 * also part of a shared mapping, and another thread has
345 * decided to launch a writepage() against this buffer.
346 */
347 J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in));
348
349 new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL);
350
351 /* keep subsequent assertions sane */
352 atomic_set(&new_bh->b_count, 1);
353
354 spin_lock(&jh_in->b_state_lock);
355 /*
356 * If a new transaction has already done a buffer copy-out, then
357 * we use that version of the data for the commit.
358 */
359 if (jh_in->b_frozen_data) {
360 new_folio = virt_to_folio(jh_in->b_frozen_data);
361 new_offset = offset_in_folio(new_folio, jh_in->b_frozen_data);
362 do_escape = jbd2_data_needs_escaping(jh_in->b_frozen_data);
363 if (do_escape)
364 jbd2_data_do_escape(jh_in->b_frozen_data);
365 } else {
366 char *tmp;
367 char *mapped_data;
368
369 new_folio = bh_in->b_folio;
370 new_offset = offset_in_folio(new_folio, bh_in->b_data);
371 mapped_data = kmap_local_folio(new_folio, new_offset);
372 /*
373 * Fire data frozen trigger if data already wasn't frozen. Do
374 * this before checking for escaping, as the trigger may modify
375 * the magic offset. If a copy-out happens afterwards, it will
376 * have the correct data in the buffer.
377 */
378 jbd2_buffer_frozen_trigger(jh_in, mapped_data,
379 jh_in->b_triggers);
380 do_escape = jbd2_data_needs_escaping(mapped_data);
381 kunmap_local(mapped_data);
382 /*
383 * Do we need to do a data copy?
384 */
385 if (!do_escape)
386 goto escape_done;
387
388 spin_unlock(&jh_in->b_state_lock);
389 tmp = jbd2_alloc(bh_in->b_size, GFP_NOFS);
390 if (!tmp) {
391 brelse(new_bh);
392 free_buffer_head(new_bh);
393 return -ENOMEM;
394 }
395 spin_lock(&jh_in->b_state_lock);
396 if (jh_in->b_frozen_data) {
397 jbd2_free(tmp, bh_in->b_size);
398 goto copy_done;
399 }
400
401 jh_in->b_frozen_data = tmp;
402 memcpy_from_folio(tmp, new_folio, new_offset, bh_in->b_size);
403 /*
404 * This isn't strictly necessary, as we're using frozen
405 * data for the escaping, but it keeps consistency with
406 * b_frozen_data usage.
407 */
408 jh_in->b_frozen_triggers = jh_in->b_triggers;
409
410 copy_done:
411 new_folio = virt_to_folio(jh_in->b_frozen_data);
412 new_offset = offset_in_folio(new_folio, jh_in->b_frozen_data);
413 jbd2_data_do_escape(jh_in->b_frozen_data);
414 }
415
416 escape_done:
417 folio_set_bh(new_bh, new_folio, new_offset);
418 new_bh->b_size = bh_in->b_size;
419 new_bh->b_bdev = journal->j_dev;
420 new_bh->b_blocknr = blocknr;
421 new_bh->b_private = bh_in;
422 set_buffer_mapped(new_bh);
423 set_buffer_dirty(new_bh);
424
425 *bh_out = new_bh;
426
427 /*
428 * The to-be-written buffer needs to get moved to the io queue,
429 * and the original buffer whose contents we are shadowing or
430 * copying is moved to the transaction's shadow queue.
431 */
432 JBUFFER_TRACE(jh_in, "file as BJ_Shadow");
433 spin_lock(&journal->j_list_lock);
434 __jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow);
435 spin_unlock(&journal->j_list_lock);
436 set_buffer_shadow(bh_in);
437 spin_unlock(&jh_in->b_state_lock);
438
439 return do_escape;
440 }
441
442 /*
443 * Allocation code for the journal file. Manage the space left in the
444 * journal, so that we can begin checkpointing when appropriate.
445 */
446
447 /*
448 * Called with j_state_lock locked for writing.
449 * Returns true if a transaction commit was started.
450 */
__jbd2_log_start_commit(journal_t * journal,tid_t target)451 static int __jbd2_log_start_commit(journal_t *journal, tid_t target)
452 {
453 /* Return if the txn has already requested to be committed */
454 if (journal->j_commit_request == target)
455 return 0;
456
457 /*
458 * The only transaction we can possibly wait upon is the
459 * currently running transaction (if it exists). Otherwise,
460 * the target tid must be an old one.
461 */
462 if (journal->j_running_transaction &&
463 journal->j_running_transaction->t_tid == target) {
464 /*
465 * We want a new commit: OK, mark the request and wakeup the
466 * commit thread. We do _not_ do the commit ourselves.
467 */
468
469 journal->j_commit_request = target;
470 jbd2_debug(1, "JBD2: requesting commit %u/%u\n",
471 journal->j_commit_request,
472 journal->j_commit_sequence);
473 journal->j_running_transaction->t_requested = jiffies;
474 wake_up(&journal->j_wait_commit);
475 return 1;
476 } else if (!tid_geq(journal->j_commit_request, target))
477 /* This should never happen, but if it does, preserve
478 the evidence before kjournald goes into a loop and
479 increments j_commit_sequence beyond all recognition. */
480 WARN_ONCE(1, "JBD2: bad log_start_commit: %u %u %u %u\n",
481 journal->j_commit_request,
482 journal->j_commit_sequence,
483 target, journal->j_running_transaction ?
484 journal->j_running_transaction->t_tid : 0);
485 return 0;
486 }
487
jbd2_log_start_commit(journal_t * journal,tid_t tid)488 int jbd2_log_start_commit(journal_t *journal, tid_t tid)
489 {
490 int ret;
491
492 write_lock(&journal->j_state_lock);
493 ret = __jbd2_log_start_commit(journal, tid);
494 write_unlock(&journal->j_state_lock);
495 return ret;
496 }
497
498 /*
499 * Force and wait any uncommitted transactions. We can only force the running
500 * transaction if we don't have an active handle, otherwise, we will deadlock.
501 * Returns: <0 in case of error,
502 * 0 if nothing to commit,
503 * 1 if transaction was successfully committed.
504 */
__jbd2_journal_force_commit(journal_t * journal)505 static int __jbd2_journal_force_commit(journal_t *journal)
506 {
507 transaction_t *transaction = NULL;
508 tid_t tid;
509 int need_to_start = 0, ret = 0;
510
511 read_lock(&journal->j_state_lock);
512 if (journal->j_running_transaction && !current->journal_info) {
513 transaction = journal->j_running_transaction;
514 if (!tid_geq(journal->j_commit_request, transaction->t_tid))
515 need_to_start = 1;
516 } else if (journal->j_committing_transaction)
517 transaction = journal->j_committing_transaction;
518
519 if (!transaction) {
520 /* Nothing to commit */
521 read_unlock(&journal->j_state_lock);
522 return 0;
523 }
524 tid = transaction->t_tid;
525 read_unlock(&journal->j_state_lock);
526 if (need_to_start)
527 jbd2_log_start_commit(journal, tid);
528 ret = jbd2_log_wait_commit(journal, tid);
529 if (!ret)
530 ret = 1;
531
532 return ret;
533 }
534
535 /**
536 * jbd2_journal_force_commit_nested - Force and wait upon a commit if the
537 * calling process is not within transaction.
538 *
539 * @journal: journal to force
540 * Returns true if progress was made.
541 *
542 * This is used for forcing out undo-protected data which contains
543 * bitmaps, when the fs is running out of space.
544 */
jbd2_journal_force_commit_nested(journal_t * journal)545 int jbd2_journal_force_commit_nested(journal_t *journal)
546 {
547 int ret;
548
549 ret = __jbd2_journal_force_commit(journal);
550 return ret > 0;
551 }
552
553 /**
554 * jbd2_journal_force_commit() - force any uncommitted transactions
555 * @journal: journal to force
556 *
557 * Caller want unconditional commit. We can only force the running transaction
558 * if we don't have an active handle, otherwise, we will deadlock.
559 */
jbd2_journal_force_commit(journal_t * journal)560 int jbd2_journal_force_commit(journal_t *journal)
561 {
562 int ret;
563
564 J_ASSERT(!current->journal_info);
565 ret = __jbd2_journal_force_commit(journal);
566 if (ret > 0)
567 ret = 0;
568 return ret;
569 }
570
571 /*
572 * Start a commit of the current running transaction (if any). Returns true
573 * if a transaction is going to be committed (or is currently already
574 * committing), and fills its tid in at *ptid
575 */
jbd2_journal_start_commit(journal_t * journal,tid_t * ptid)576 int jbd2_journal_start_commit(journal_t *journal, tid_t *ptid)
577 {
578 int ret = 0;
579
580 write_lock(&journal->j_state_lock);
581 if (journal->j_running_transaction) {
582 tid_t tid = journal->j_running_transaction->t_tid;
583
584 __jbd2_log_start_commit(journal, tid);
585 /* There's a running transaction and we've just made sure
586 * it's commit has been scheduled. */
587 if (ptid)
588 *ptid = tid;
589 ret = 1;
590 } else if (journal->j_committing_transaction) {
591 /*
592 * If commit has been started, then we have to wait for
593 * completion of that transaction.
594 */
595 if (ptid)
596 *ptid = journal->j_committing_transaction->t_tid;
597 ret = 1;
598 }
599 write_unlock(&journal->j_state_lock);
600 return ret;
601 }
602
603 /*
604 * Return 1 if a given transaction has not yet sent barrier request
605 * connected with a transaction commit. If 0 is returned, transaction
606 * may or may not have sent the barrier. Used to avoid sending barrier
607 * twice in common cases.
608 */
jbd2_trans_will_send_data_barrier(journal_t * journal,tid_t tid)609 int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid)
610 {
611 int ret = 0;
612 transaction_t *commit_trans;
613
614 if (!(journal->j_flags & JBD2_BARRIER))
615 return 0;
616 read_lock(&journal->j_state_lock);
617 /* Transaction already committed? */
618 if (tid_geq(journal->j_commit_sequence, tid))
619 goto out;
620 commit_trans = journal->j_committing_transaction;
621 if (!commit_trans || commit_trans->t_tid != tid) {
622 ret = 1;
623 goto out;
624 }
625 /*
626 * Transaction is being committed and we already proceeded to
627 * submitting a flush to fs partition?
628 */
629 if (journal->j_fs_dev != journal->j_dev) {
630 if (!commit_trans->t_need_data_flush ||
631 commit_trans->t_state >= T_COMMIT_DFLUSH)
632 goto out;
633 } else {
634 if (commit_trans->t_state >= T_COMMIT_JFLUSH)
635 goto out;
636 }
637 ret = 1;
638 out:
639 read_unlock(&journal->j_state_lock);
640 return ret;
641 }
642 EXPORT_SYMBOL(jbd2_trans_will_send_data_barrier);
643
644 /*
645 * Wait for a specified commit to complete.
646 * The caller may not hold the journal lock.
647 */
jbd2_log_wait_commit(journal_t * journal,tid_t tid)648 int jbd2_log_wait_commit(journal_t *journal, tid_t tid)
649 {
650 int err = 0;
651
652 read_lock(&journal->j_state_lock);
653 #ifdef CONFIG_PROVE_LOCKING
654 /*
655 * Some callers make sure transaction is already committing and in that
656 * case we cannot block on open handles anymore. So don't warn in that
657 * case.
658 */
659 if (tid_gt(tid, journal->j_commit_sequence) &&
660 (!journal->j_committing_transaction ||
661 journal->j_committing_transaction->t_tid != tid)) {
662 read_unlock(&journal->j_state_lock);
663 jbd2_might_wait_for_commit(journal);
664 read_lock(&journal->j_state_lock);
665 }
666 #endif
667 #ifdef CONFIG_JBD2_DEBUG
668 if (!tid_geq(journal->j_commit_request, tid)) {
669 printk(KERN_ERR
670 "%s: error: j_commit_request=%u, tid=%u\n",
671 __func__, journal->j_commit_request, tid);
672 }
673 #endif
674 while (tid_gt(tid, journal->j_commit_sequence)) {
675 jbd2_debug(1, "JBD2: want %u, j_commit_sequence=%u\n",
676 tid, journal->j_commit_sequence);
677 read_unlock(&journal->j_state_lock);
678 wake_up(&journal->j_wait_commit);
679 wait_event(journal->j_wait_done_commit,
680 !tid_gt(tid, journal->j_commit_sequence));
681 read_lock(&journal->j_state_lock);
682 }
683 read_unlock(&journal->j_state_lock);
684
685 if (unlikely(is_journal_aborted(journal)))
686 err = -EIO;
687 return err;
688 }
689
690 /*
691 * Start a fast commit. If there's an ongoing fast or full commit wait for
692 * it to complete. Returns 0 if a new fast commit was started. Returns -EALREADY
693 * if a fast commit is not needed, either because there's an already a commit
694 * going on or this tid has already been committed. Returns -EINVAL if no jbd2
695 * commit has yet been performed.
696 */
jbd2_fc_begin_commit(journal_t * journal,tid_t tid)697 int jbd2_fc_begin_commit(journal_t *journal, tid_t tid)
698 {
699 if (unlikely(is_journal_aborted(journal)))
700 return -EIO;
701 /*
702 * Fast commits only allowed if at least one full commit has
703 * been processed.
704 */
705 if (!journal->j_stats.ts_tid)
706 return -EINVAL;
707
708 write_lock(&journal->j_state_lock);
709 if (tid_geq(journal->j_commit_sequence, tid)) {
710 write_unlock(&journal->j_state_lock);
711 return -EALREADY;
712 }
713
714 if (journal->j_flags & JBD2_FULL_COMMIT_ONGOING ||
715 (journal->j_flags & JBD2_FAST_COMMIT_ONGOING)) {
716 DEFINE_WAIT(wait);
717
718 prepare_to_wait(&journal->j_fc_wait, &wait,
719 TASK_UNINTERRUPTIBLE);
720 write_unlock(&journal->j_state_lock);
721 schedule();
722 finish_wait(&journal->j_fc_wait, &wait);
723 return -EALREADY;
724 }
725 journal->j_flags |= JBD2_FAST_COMMIT_ONGOING;
726 write_unlock(&journal->j_state_lock);
727 jbd2_journal_lock_updates(journal);
728
729 return 0;
730 }
731 EXPORT_SYMBOL(jbd2_fc_begin_commit);
732
733 /*
734 * Stop a fast commit. If fallback is set, this function starts commit of
735 * TID tid before any other fast commit can start.
736 */
__jbd2_fc_end_commit(journal_t * journal,tid_t tid,bool fallback)737 static int __jbd2_fc_end_commit(journal_t *journal, tid_t tid, bool fallback)
738 {
739 if (journal->j_fc_cleanup_callback)
740 journal->j_fc_cleanup_callback(journal, 0, tid);
741 jbd2_journal_unlock_updates(journal);
742 write_lock(&journal->j_state_lock);
743 journal->j_flags &= ~JBD2_FAST_COMMIT_ONGOING;
744 if (fallback)
745 journal->j_flags |= JBD2_FULL_COMMIT_ONGOING;
746 write_unlock(&journal->j_state_lock);
747 wake_up(&journal->j_fc_wait);
748 if (fallback)
749 return jbd2_complete_transaction(journal, tid);
750 return 0;
751 }
752
jbd2_fc_end_commit(journal_t * journal)753 int jbd2_fc_end_commit(journal_t *journal)
754 {
755 return __jbd2_fc_end_commit(journal, 0, false);
756 }
757 EXPORT_SYMBOL(jbd2_fc_end_commit);
758
jbd2_fc_end_commit_fallback(journal_t * journal)759 int jbd2_fc_end_commit_fallback(journal_t *journal)
760 {
761 tid_t tid;
762
763 read_lock(&journal->j_state_lock);
764 tid = journal->j_running_transaction ?
765 journal->j_running_transaction->t_tid : 0;
766 read_unlock(&journal->j_state_lock);
767 return __jbd2_fc_end_commit(journal, tid, true);
768 }
769 EXPORT_SYMBOL(jbd2_fc_end_commit_fallback);
770
771 /* Return 1 when transaction with given tid has already committed. */
jbd2_transaction_committed(journal_t * journal,tid_t tid)772 int jbd2_transaction_committed(journal_t *journal, tid_t tid)
773 {
774 return tid_geq(READ_ONCE(journal->j_commit_sequence), tid);
775 }
776 EXPORT_SYMBOL(jbd2_transaction_committed);
777
778 /*
779 * When this function returns the transaction corresponding to tid
780 * will be completed. If the transaction has currently running, start
781 * committing that transaction before waiting for it to complete. If
782 * the transaction id is stale, it is by definition already completed,
783 * so just return SUCCESS.
784 */
jbd2_complete_transaction(journal_t * journal,tid_t tid)785 int jbd2_complete_transaction(journal_t *journal, tid_t tid)
786 {
787 int need_to_wait = 1;
788
789 read_lock(&journal->j_state_lock);
790 if (journal->j_running_transaction &&
791 journal->j_running_transaction->t_tid == tid) {
792 if (journal->j_commit_request != tid) {
793 /* transaction not yet started, so request it */
794 read_unlock(&journal->j_state_lock);
795 jbd2_log_start_commit(journal, tid);
796 goto wait_commit;
797 }
798 } else if (!(journal->j_committing_transaction &&
799 journal->j_committing_transaction->t_tid == tid))
800 need_to_wait = 0;
801 read_unlock(&journal->j_state_lock);
802 if (!need_to_wait)
803 return 0;
804 wait_commit:
805 return jbd2_log_wait_commit(journal, tid);
806 }
807 EXPORT_SYMBOL(jbd2_complete_transaction);
808
809 /*
810 * Log buffer allocation routines:
811 */
812
jbd2_journal_next_log_block(journal_t * journal,unsigned long long * retp)813 int jbd2_journal_next_log_block(journal_t *journal, unsigned long long *retp)
814 {
815 unsigned long blocknr;
816
817 write_lock(&journal->j_state_lock);
818 J_ASSERT(journal->j_free > 1);
819
820 blocknr = journal->j_head;
821 journal->j_head++;
822 journal->j_free--;
823 if (journal->j_head == journal->j_last)
824 journal->j_head = journal->j_first;
825 write_unlock(&journal->j_state_lock);
826 return jbd2_journal_bmap(journal, blocknr, retp);
827 }
828
829 /* Map one fast commit buffer for use by the file system */
jbd2_fc_get_buf(journal_t * journal,struct buffer_head ** bh_out)830 int jbd2_fc_get_buf(journal_t *journal, struct buffer_head **bh_out)
831 {
832 unsigned long long pblock;
833 unsigned long blocknr;
834 int ret = 0;
835 struct buffer_head *bh;
836 int fc_off;
837
838 *bh_out = NULL;
839
840 if (journal->j_fc_off + journal->j_fc_first >= journal->j_fc_last)
841 return -EINVAL;
842
843 fc_off = journal->j_fc_off;
844 blocknr = journal->j_fc_first + fc_off;
845 journal->j_fc_off++;
846 ret = jbd2_journal_bmap(journal, blocknr, &pblock);
847 if (ret)
848 return ret;
849
850 bh = __getblk(journal->j_dev, pblock, journal->j_blocksize);
851 if (!bh)
852 return -ENOMEM;
853
854 journal->j_fc_wbuf[fc_off] = bh;
855
856 *bh_out = bh;
857
858 return 0;
859 }
860 EXPORT_SYMBOL(jbd2_fc_get_buf);
861
862 /*
863 * Wait on fast commit buffers that were allocated by jbd2_fc_get_buf
864 * for completion.
865 */
jbd2_fc_wait_bufs(journal_t * journal,int num_blks)866 int jbd2_fc_wait_bufs(journal_t *journal, int num_blks)
867 {
868 struct buffer_head *bh;
869 int i, j_fc_off;
870
871 j_fc_off = journal->j_fc_off;
872
873 /*
874 * Wait in reverse order to minimize chances of us being woken up before
875 * all IOs have completed
876 */
877 for (i = j_fc_off - 1; i >= j_fc_off - num_blks; i--) {
878 bh = journal->j_fc_wbuf[i];
879 wait_on_buffer(bh);
880 /*
881 * Update j_fc_off so jbd2_fc_release_bufs can release remain
882 * buffer head.
883 */
884 if (unlikely(!buffer_uptodate(bh))) {
885 journal->j_fc_off = i + 1;
886 return -EIO;
887 }
888 put_bh(bh);
889 journal->j_fc_wbuf[i] = NULL;
890 }
891
892 return 0;
893 }
894 EXPORT_SYMBOL(jbd2_fc_wait_bufs);
895
jbd2_fc_release_bufs(journal_t * journal)896 void jbd2_fc_release_bufs(journal_t *journal)
897 {
898 struct buffer_head *bh;
899 int i, j_fc_off;
900
901 j_fc_off = journal->j_fc_off;
902
903 for (i = j_fc_off - 1; i >= 0; i--) {
904 bh = journal->j_fc_wbuf[i];
905 if (!bh)
906 break;
907 put_bh(bh);
908 journal->j_fc_wbuf[i] = NULL;
909 }
910 }
911 EXPORT_SYMBOL(jbd2_fc_release_bufs);
912
913 /*
914 * Conversion of logical to physical block numbers for the journal
915 *
916 * On external journals the journal blocks are identity-mapped, so
917 * this is a no-op. If needed, we can use j_blk_offset - everything is
918 * ready.
919 */
jbd2_journal_bmap(journal_t * journal,unsigned long blocknr,unsigned long long * retp)920 int jbd2_journal_bmap(journal_t *journal, unsigned long blocknr,
921 unsigned long long *retp)
922 {
923 int err = 0;
924 unsigned long long ret;
925 sector_t block = blocknr;
926
927 if (journal->j_bmap) {
928 err = journal->j_bmap(journal, &block);
929 if (err == 0)
930 *retp = block;
931 } else if (journal->j_inode) {
932 ret = bmap(journal->j_inode, &block);
933
934 if (ret || !block) {
935 printk(KERN_ALERT "%s: journal block not found "
936 "at offset %lu on %s\n",
937 __func__, blocknr, journal->j_devname);
938 err = -EIO;
939 jbd2_journal_abort(journal, err);
940 } else {
941 *retp = block;
942 }
943
944 } else {
945 *retp = blocknr; /* +journal->j_blk_offset */
946 }
947 return err;
948 }
949
950 /*
951 * We play buffer_head aliasing tricks to write data/metadata blocks to
952 * the journal without copying their contents, but for journal
953 * descriptor blocks we do need to generate bona fide buffers.
954 *
955 * After the caller of jbd2_journal_get_descriptor_buffer() has finished modifying
956 * the buffer's contents they really should run flush_dcache_page(bh->b_page).
957 * But we don't bother doing that, so there will be coherency problems with
958 * mmaps of blockdevs which hold live JBD-controlled filesystems.
959 */
960 struct buffer_head *
jbd2_journal_get_descriptor_buffer(transaction_t * transaction,int type)961 jbd2_journal_get_descriptor_buffer(transaction_t *transaction, int type)
962 {
963 journal_t *journal = transaction->t_journal;
964 struct buffer_head *bh;
965 unsigned long long blocknr;
966 journal_header_t *header;
967 int err;
968
969 err = jbd2_journal_next_log_block(journal, &blocknr);
970
971 if (err)
972 return NULL;
973
974 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
975 if (!bh)
976 return NULL;
977 atomic_dec(&transaction->t_outstanding_credits);
978 lock_buffer(bh);
979 memset(bh->b_data, 0, journal->j_blocksize);
980 header = (journal_header_t *)bh->b_data;
981 header->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER);
982 header->h_blocktype = cpu_to_be32(type);
983 header->h_sequence = cpu_to_be32(transaction->t_tid);
984 set_buffer_uptodate(bh);
985 unlock_buffer(bh);
986 BUFFER_TRACE(bh, "return this buffer");
987 return bh;
988 }
989
jbd2_descriptor_block_csum_set(journal_t * j,struct buffer_head * bh)990 void jbd2_descriptor_block_csum_set(journal_t *j, struct buffer_head *bh)
991 {
992 struct jbd2_journal_block_tail *tail;
993 __u32 csum;
994
995 if (!jbd2_journal_has_csum_v2or3(j))
996 return;
997
998 tail = (struct jbd2_journal_block_tail *)(bh->b_data + j->j_blocksize -
999 sizeof(struct jbd2_journal_block_tail));
1000 tail->t_checksum = 0;
1001 csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize);
1002 tail->t_checksum = cpu_to_be32(csum);
1003 }
1004
1005 /*
1006 * Return tid of the oldest transaction in the journal and block in the journal
1007 * where the transaction starts.
1008 *
1009 * If the journal is now empty, return which will be the next transaction ID
1010 * we will write and where will that transaction start.
1011 *
1012 * The return value is 0 if journal tail cannot be pushed any further, 1 if
1013 * it can.
1014 */
jbd2_journal_get_log_tail(journal_t * journal,tid_t * tid,unsigned long * block)1015 int jbd2_journal_get_log_tail(journal_t *journal, tid_t *tid,
1016 unsigned long *block)
1017 {
1018 transaction_t *transaction;
1019 int ret;
1020
1021 read_lock(&journal->j_state_lock);
1022 spin_lock(&journal->j_list_lock);
1023 transaction = journal->j_checkpoint_transactions;
1024 if (transaction) {
1025 *tid = transaction->t_tid;
1026 *block = transaction->t_log_start;
1027 } else if ((transaction = journal->j_committing_transaction) != NULL) {
1028 *tid = transaction->t_tid;
1029 *block = transaction->t_log_start;
1030 } else if ((transaction = journal->j_running_transaction) != NULL) {
1031 *tid = transaction->t_tid;
1032 *block = journal->j_head;
1033 } else {
1034 *tid = journal->j_transaction_sequence;
1035 *block = journal->j_head;
1036 }
1037 ret = tid_gt(*tid, journal->j_tail_sequence);
1038 spin_unlock(&journal->j_list_lock);
1039 read_unlock(&journal->j_state_lock);
1040
1041 return ret;
1042 }
1043
1044 /*
1045 * Update information in journal structure and in on disk journal superblock
1046 * about log tail. This function does not check whether information passed in
1047 * really pushes log tail further. It's responsibility of the caller to make
1048 * sure provided log tail information is valid (e.g. by holding
1049 * j_checkpoint_mutex all the time between computing log tail and calling this
1050 * function as is the case with jbd2_cleanup_journal_tail()).
1051 *
1052 * Requires j_checkpoint_mutex
1053 */
__jbd2_update_log_tail(journal_t * journal,tid_t tid,unsigned long block)1054 int __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block)
1055 {
1056 unsigned long freed;
1057 int ret;
1058
1059 BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
1060
1061 /*
1062 * We cannot afford for write to remain in drive's caches since as
1063 * soon as we update j_tail, next transaction can start reusing journal
1064 * space and if we lose sb update during power failure we'd replay
1065 * old transaction with possibly newly overwritten data.
1066 */
1067 ret = jbd2_journal_update_sb_log_tail(journal, tid, block, REQ_FUA);
1068 if (ret)
1069 goto out;
1070
1071 write_lock(&journal->j_state_lock);
1072 freed = block - journal->j_tail;
1073 if (block < journal->j_tail)
1074 freed += journal->j_last - journal->j_first;
1075
1076 trace_jbd2_update_log_tail(journal, tid, block, freed);
1077 jbd2_debug(1,
1078 "Cleaning journal tail from %u to %u (offset %lu), "
1079 "freeing %lu\n",
1080 journal->j_tail_sequence, tid, block, freed);
1081
1082 journal->j_free += freed;
1083 journal->j_tail_sequence = tid;
1084 journal->j_tail = block;
1085 write_unlock(&journal->j_state_lock);
1086
1087 out:
1088 return ret;
1089 }
1090
1091 /*
1092 * This is a variation of __jbd2_update_log_tail which checks for validity of
1093 * provided log tail and locks j_checkpoint_mutex. So it is safe against races
1094 * with other threads updating log tail.
1095 */
jbd2_update_log_tail(journal_t * journal,tid_t tid,unsigned long block)1096 void jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block)
1097 {
1098 mutex_lock_io(&journal->j_checkpoint_mutex);
1099 if (tid_gt(tid, journal->j_tail_sequence))
1100 __jbd2_update_log_tail(journal, tid, block);
1101 mutex_unlock(&journal->j_checkpoint_mutex);
1102 }
1103
1104 struct jbd2_stats_proc_session {
1105 journal_t *journal;
1106 struct transaction_stats_s *stats;
1107 int start;
1108 int max;
1109 };
1110
jbd2_seq_info_start(struct seq_file * seq,loff_t * pos)1111 static void *jbd2_seq_info_start(struct seq_file *seq, loff_t *pos)
1112 {
1113 return *pos ? NULL : SEQ_START_TOKEN;
1114 }
1115
jbd2_seq_info_next(struct seq_file * seq,void * v,loff_t * pos)1116 static void *jbd2_seq_info_next(struct seq_file *seq, void *v, loff_t *pos)
1117 {
1118 (*pos)++;
1119 return NULL;
1120 }
1121
jbd2_seq_info_show(struct seq_file * seq,void * v)1122 static int jbd2_seq_info_show(struct seq_file *seq, void *v)
1123 {
1124 struct jbd2_stats_proc_session *s = seq->private;
1125
1126 if (v != SEQ_START_TOKEN)
1127 return 0;
1128 seq_printf(seq, "%lu transactions (%lu requested), "
1129 "each up to %u blocks\n",
1130 s->stats->ts_tid, s->stats->ts_requested,
1131 s->journal->j_max_transaction_buffers);
1132 if (s->stats->ts_tid == 0)
1133 return 0;
1134 seq_printf(seq, "average: \n %ums waiting for transaction\n",
1135 jiffies_to_msecs(s->stats->run.rs_wait / s->stats->ts_tid));
1136 seq_printf(seq, " %ums request delay\n",
1137 (s->stats->ts_requested == 0) ? 0 :
1138 jiffies_to_msecs(s->stats->run.rs_request_delay /
1139 s->stats->ts_requested));
1140 seq_printf(seq, " %ums running transaction\n",
1141 jiffies_to_msecs(s->stats->run.rs_running / s->stats->ts_tid));
1142 seq_printf(seq, " %ums transaction was being locked\n",
1143 jiffies_to_msecs(s->stats->run.rs_locked / s->stats->ts_tid));
1144 seq_printf(seq, " %ums flushing data (in ordered mode)\n",
1145 jiffies_to_msecs(s->stats->run.rs_flushing / s->stats->ts_tid));
1146 seq_printf(seq, " %ums logging transaction\n",
1147 jiffies_to_msecs(s->stats->run.rs_logging / s->stats->ts_tid));
1148 seq_printf(seq, " %lluus average transaction commit time\n",
1149 div_u64(s->journal->j_average_commit_time, 1000));
1150 seq_printf(seq, " %lu handles per transaction\n",
1151 s->stats->run.rs_handle_count / s->stats->ts_tid);
1152 seq_printf(seq, " %lu blocks per transaction\n",
1153 s->stats->run.rs_blocks / s->stats->ts_tid);
1154 seq_printf(seq, " %lu logged blocks per transaction\n",
1155 s->stats->run.rs_blocks_logged / s->stats->ts_tid);
1156 return 0;
1157 }
1158
jbd2_seq_info_stop(struct seq_file * seq,void * v)1159 static void jbd2_seq_info_stop(struct seq_file *seq, void *v)
1160 {
1161 }
1162
1163 static const struct seq_operations jbd2_seq_info_ops = {
1164 .start = jbd2_seq_info_start,
1165 .next = jbd2_seq_info_next,
1166 .stop = jbd2_seq_info_stop,
1167 .show = jbd2_seq_info_show,
1168 };
1169
jbd2_seq_info_open(struct inode * inode,struct file * file)1170 static int jbd2_seq_info_open(struct inode *inode, struct file *file)
1171 {
1172 journal_t *journal = pde_data(inode);
1173 struct jbd2_stats_proc_session *s;
1174 int rc, size;
1175
1176 s = kmalloc(sizeof(*s), GFP_KERNEL);
1177 if (s == NULL)
1178 return -ENOMEM;
1179 size = sizeof(struct transaction_stats_s);
1180 s->stats = kmalloc(size, GFP_KERNEL);
1181 if (s->stats == NULL) {
1182 kfree(s);
1183 return -ENOMEM;
1184 }
1185 spin_lock(&journal->j_history_lock);
1186 memcpy(s->stats, &journal->j_stats, size);
1187 s->journal = journal;
1188 spin_unlock(&journal->j_history_lock);
1189
1190 rc = seq_open(file, &jbd2_seq_info_ops);
1191 if (rc == 0) {
1192 struct seq_file *m = file->private_data;
1193 m->private = s;
1194 } else {
1195 kfree(s->stats);
1196 kfree(s);
1197 }
1198 return rc;
1199
1200 }
1201
jbd2_seq_info_release(struct inode * inode,struct file * file)1202 static int jbd2_seq_info_release(struct inode *inode, struct file *file)
1203 {
1204 struct seq_file *seq = file->private_data;
1205 struct jbd2_stats_proc_session *s = seq->private;
1206 kfree(s->stats);
1207 kfree(s);
1208 return seq_release(inode, file);
1209 }
1210
1211 static const struct proc_ops jbd2_info_proc_ops = {
1212 .proc_open = jbd2_seq_info_open,
1213 .proc_read = seq_read,
1214 .proc_lseek = seq_lseek,
1215 .proc_release = jbd2_seq_info_release,
1216 };
1217
1218 static struct proc_dir_entry *proc_jbd2_stats;
1219
jbd2_stats_proc_init(journal_t * journal)1220 static void jbd2_stats_proc_init(journal_t *journal)
1221 {
1222 journal->j_proc_entry = proc_mkdir(journal->j_devname, proc_jbd2_stats);
1223 if (journal->j_proc_entry) {
1224 proc_create_data("info", S_IRUGO, journal->j_proc_entry,
1225 &jbd2_info_proc_ops, journal);
1226 }
1227 }
1228
jbd2_stats_proc_exit(journal_t * journal)1229 static void jbd2_stats_proc_exit(journal_t *journal)
1230 {
1231 remove_proc_entry("info", journal->j_proc_entry);
1232 remove_proc_entry(journal->j_devname, proc_jbd2_stats);
1233 }
1234
1235 /* Minimum size of descriptor tag */
jbd2_min_tag_size(void)1236 static int jbd2_min_tag_size(void)
1237 {
1238 /*
1239 * Tag with 32-bit block numbers does not use last four bytes of the
1240 * structure
1241 */
1242 return sizeof(journal_block_tag_t) - 4;
1243 }
1244
1245 /**
1246 * jbd2_journal_shrink_scan()
1247 * @shrink: shrinker to work on
1248 * @sc: reclaim request to process
1249 *
1250 * Scan the checkpointed buffer on the checkpoint list and release the
1251 * journal_head.
1252 */
jbd2_journal_shrink_scan(struct shrinker * shrink,struct shrink_control * sc)1253 static unsigned long jbd2_journal_shrink_scan(struct shrinker *shrink,
1254 struct shrink_control *sc)
1255 {
1256 journal_t *journal = shrink->private_data;
1257 unsigned long nr_to_scan = sc->nr_to_scan;
1258 unsigned long nr_shrunk;
1259 unsigned long count;
1260
1261 count = percpu_counter_read_positive(&journal->j_checkpoint_jh_count);
1262 trace_jbd2_shrink_scan_enter(journal, sc->nr_to_scan, count);
1263
1264 nr_shrunk = jbd2_journal_shrink_checkpoint_list(journal, &nr_to_scan);
1265
1266 count = percpu_counter_read_positive(&journal->j_checkpoint_jh_count);
1267 trace_jbd2_shrink_scan_exit(journal, nr_to_scan, nr_shrunk, count);
1268
1269 return nr_shrunk;
1270 }
1271
1272 /**
1273 * jbd2_journal_shrink_count()
1274 * @shrink: shrinker to work on
1275 * @sc: reclaim request to process
1276 *
1277 * Count the number of checkpoint buffers on the checkpoint list.
1278 */
jbd2_journal_shrink_count(struct shrinker * shrink,struct shrink_control * sc)1279 static unsigned long jbd2_journal_shrink_count(struct shrinker *shrink,
1280 struct shrink_control *sc)
1281 {
1282 journal_t *journal = shrink->private_data;
1283 unsigned long count;
1284
1285 count = percpu_counter_read_positive(&journal->j_checkpoint_jh_count);
1286 trace_jbd2_shrink_count(journal, sc->nr_to_scan, count);
1287
1288 return count;
1289 }
1290
1291 /*
1292 * If the journal init or create aborts, we need to mark the journal
1293 * superblock as being NULL to prevent the journal destroy from writing
1294 * back a bogus superblock.
1295 */
journal_fail_superblock(journal_t * journal)1296 static void journal_fail_superblock(journal_t *journal)
1297 {
1298 struct buffer_head *bh = journal->j_sb_buffer;
1299 brelse(bh);
1300 journal->j_sb_buffer = NULL;
1301 }
1302
1303 /*
1304 * Check the superblock for a given journal, performing initial
1305 * validation of the format.
1306 */
journal_check_superblock(journal_t * journal)1307 static int journal_check_superblock(journal_t *journal)
1308 {
1309 journal_superblock_t *sb = journal->j_superblock;
1310 int num_fc_blks;
1311 int err = -EINVAL;
1312
1313 if (sb->s_header.h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER) ||
1314 sb->s_blocksize != cpu_to_be32(journal->j_blocksize)) {
1315 printk(KERN_WARNING "JBD2: no valid journal superblock found\n");
1316 return err;
1317 }
1318
1319 if (be32_to_cpu(sb->s_header.h_blocktype) != JBD2_SUPERBLOCK_V1 &&
1320 be32_to_cpu(sb->s_header.h_blocktype) != JBD2_SUPERBLOCK_V2) {
1321 printk(KERN_WARNING "JBD2: unrecognised superblock format ID\n");
1322 return err;
1323 }
1324
1325 if (be32_to_cpu(sb->s_maxlen) > journal->j_total_len) {
1326 printk(KERN_WARNING "JBD2: journal file too short\n");
1327 return err;
1328 }
1329
1330 if (be32_to_cpu(sb->s_first) == 0 ||
1331 be32_to_cpu(sb->s_first) >= journal->j_total_len) {
1332 printk(KERN_WARNING
1333 "JBD2: Invalid start block of journal: %u\n",
1334 be32_to_cpu(sb->s_first));
1335 return err;
1336 }
1337
1338 /*
1339 * If this is a V2 superblock, then we have to check the
1340 * features flags on it.
1341 */
1342 if (!jbd2_format_support_feature(journal))
1343 return 0;
1344
1345 if ((sb->s_feature_ro_compat &
1346 ~cpu_to_be32(JBD2_KNOWN_ROCOMPAT_FEATURES)) ||
1347 (sb->s_feature_incompat &
1348 ~cpu_to_be32(JBD2_KNOWN_INCOMPAT_FEATURES))) {
1349 printk(KERN_WARNING "JBD2: Unrecognised features on journal\n");
1350 return err;
1351 }
1352
1353 num_fc_blks = jbd2_has_feature_fast_commit(journal) ?
1354 jbd2_journal_get_num_fc_blks(sb) : 0;
1355 if (be32_to_cpu(sb->s_maxlen) < JBD2_MIN_JOURNAL_BLOCKS ||
1356 be32_to_cpu(sb->s_maxlen) - JBD2_MIN_JOURNAL_BLOCKS < num_fc_blks) {
1357 printk(KERN_ERR "JBD2: journal file too short %u,%d\n",
1358 be32_to_cpu(sb->s_maxlen), num_fc_blks);
1359 return err;
1360 }
1361
1362 if (jbd2_has_feature_csum2(journal) &&
1363 jbd2_has_feature_csum3(journal)) {
1364 /* Can't have checksum v2 and v3 at the same time! */
1365 printk(KERN_ERR "JBD2: Can't enable checksumming v2 and v3 "
1366 "at the same time!\n");
1367 return err;
1368 }
1369
1370 if (jbd2_journal_has_csum_v2or3_feature(journal) &&
1371 jbd2_has_feature_checksum(journal)) {
1372 /* Can't have checksum v1 and v2 on at the same time! */
1373 printk(KERN_ERR "JBD2: Can't enable checksumming v1 and v2/3 "
1374 "at the same time!\n");
1375 return err;
1376 }
1377
1378 /* Load the checksum driver */
1379 if (jbd2_journal_has_csum_v2or3_feature(journal)) {
1380 if (sb->s_checksum_type != JBD2_CRC32C_CHKSUM) {
1381 printk(KERN_ERR "JBD2: Unknown checksum type\n");
1382 return err;
1383 }
1384
1385 journal->j_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
1386 if (IS_ERR(journal->j_chksum_driver)) {
1387 printk(KERN_ERR "JBD2: Cannot load crc32c driver.\n");
1388 err = PTR_ERR(journal->j_chksum_driver);
1389 journal->j_chksum_driver = NULL;
1390 return err;
1391 }
1392 /* Check superblock checksum */
1393 if (sb->s_checksum != jbd2_superblock_csum(journal, sb)) {
1394 printk(KERN_ERR "JBD2: journal checksum error\n");
1395 err = -EFSBADCRC;
1396 return err;
1397 }
1398 }
1399
1400 return 0;
1401 }
1402
journal_revoke_records_per_block(journal_t * journal)1403 static int journal_revoke_records_per_block(journal_t *journal)
1404 {
1405 int record_size;
1406 int space = journal->j_blocksize - sizeof(jbd2_journal_revoke_header_t);
1407
1408 if (jbd2_has_feature_64bit(journal))
1409 record_size = 8;
1410 else
1411 record_size = 4;
1412
1413 if (jbd2_journal_has_csum_v2or3(journal))
1414 space -= sizeof(struct jbd2_journal_block_tail);
1415 return space / record_size;
1416 }
1417
jbd2_journal_get_max_txn_bufs(journal_t * journal)1418 static int jbd2_journal_get_max_txn_bufs(journal_t *journal)
1419 {
1420 return (journal->j_total_len - journal->j_fc_wbufsize) / 3;
1421 }
1422
1423 /*
1424 * Base amount of descriptor blocks we reserve for each transaction.
1425 */
jbd2_descriptor_blocks_per_trans(journal_t * journal)1426 static int jbd2_descriptor_blocks_per_trans(journal_t *journal)
1427 {
1428 int tag_space = journal->j_blocksize - sizeof(journal_header_t);
1429 int tags_per_block;
1430
1431 /* Subtract UUID */
1432 tag_space -= 16;
1433 if (jbd2_journal_has_csum_v2or3(journal))
1434 tag_space -= sizeof(struct jbd2_journal_block_tail);
1435 /* Commit code leaves a slack space of 16 bytes at the end of block */
1436 tags_per_block = (tag_space - 16) / journal_tag_bytes(journal);
1437 /*
1438 * Revoke descriptors are accounted separately so we need to reserve
1439 * space for commit block and normal transaction descriptor blocks.
1440 */
1441 return 1 + DIV_ROUND_UP(jbd2_journal_get_max_txn_bufs(journal),
1442 tags_per_block);
1443 }
1444
1445 /*
1446 * Initialize number of blocks each transaction reserves for its bookkeeping
1447 * and maximum number of blocks a transaction can use. This needs to be called
1448 * after the journal size and the fastcommit area size are initialized.
1449 */
jbd2_journal_init_transaction_limits(journal_t * journal)1450 static void jbd2_journal_init_transaction_limits(journal_t *journal)
1451 {
1452 journal->j_revoke_records_per_block =
1453 journal_revoke_records_per_block(journal);
1454 journal->j_transaction_overhead_buffers =
1455 jbd2_descriptor_blocks_per_trans(journal);
1456 journal->j_max_transaction_buffers =
1457 jbd2_journal_get_max_txn_bufs(journal);
1458 }
1459
1460 /*
1461 * Load the on-disk journal superblock and read the key fields into the
1462 * journal_t.
1463 */
journal_load_superblock(journal_t * journal)1464 static int journal_load_superblock(journal_t *journal)
1465 {
1466 int err;
1467 struct buffer_head *bh;
1468 journal_superblock_t *sb;
1469
1470 bh = getblk_unmovable(journal->j_dev, journal->j_blk_offset,
1471 journal->j_blocksize);
1472 if (bh)
1473 err = bh_read(bh, 0);
1474 if (!bh || err < 0) {
1475 pr_err("%s: Cannot read journal superblock\n", __func__);
1476 brelse(bh);
1477 return -EIO;
1478 }
1479
1480 journal->j_sb_buffer = bh;
1481 sb = (journal_superblock_t *)bh->b_data;
1482 journal->j_superblock = sb;
1483 err = journal_check_superblock(journal);
1484 if (err) {
1485 journal_fail_superblock(journal);
1486 return err;
1487 }
1488
1489 journal->j_tail_sequence = be32_to_cpu(sb->s_sequence);
1490 journal->j_tail = be32_to_cpu(sb->s_start);
1491 journal->j_first = be32_to_cpu(sb->s_first);
1492 journal->j_errno = be32_to_cpu(sb->s_errno);
1493 journal->j_last = be32_to_cpu(sb->s_maxlen);
1494
1495 if (be32_to_cpu(sb->s_maxlen) < journal->j_total_len)
1496 journal->j_total_len = be32_to_cpu(sb->s_maxlen);
1497 /* Precompute checksum seed for all metadata */
1498 if (jbd2_journal_has_csum_v2or3(journal))
1499 journal->j_csum_seed = jbd2_chksum(journal, ~0, sb->s_uuid,
1500 sizeof(sb->s_uuid));
1501 /* After journal features are set, we can compute transaction limits */
1502 jbd2_journal_init_transaction_limits(journal);
1503
1504 if (jbd2_has_feature_fast_commit(journal)) {
1505 journal->j_fc_last = be32_to_cpu(sb->s_maxlen);
1506 journal->j_last = journal->j_fc_last -
1507 jbd2_journal_get_num_fc_blks(sb);
1508 journal->j_fc_first = journal->j_last + 1;
1509 journal->j_fc_off = 0;
1510 }
1511
1512 return 0;
1513 }
1514
1515
1516 /*
1517 * Management for journal control blocks: functions to create and
1518 * destroy journal_t structures, and to initialise and read existing
1519 * journal blocks from disk. */
1520
1521 /* First: create and setup a journal_t object in memory. We initialise
1522 * very few fields yet: that has to wait until we have created the
1523 * journal structures from from scratch, or loaded them from disk. */
1524
journal_init_common(struct block_device * bdev,struct block_device * fs_dev,unsigned long long start,int len,int blocksize)1525 static journal_t *journal_init_common(struct block_device *bdev,
1526 struct block_device *fs_dev,
1527 unsigned long long start, int len, int blocksize)
1528 {
1529 static struct lock_class_key jbd2_trans_commit_key;
1530 journal_t *journal;
1531 int err;
1532 int n;
1533
1534 journal = kzalloc(sizeof(*journal), GFP_KERNEL);
1535 if (!journal)
1536 return ERR_PTR(-ENOMEM);
1537
1538 journal->j_blocksize = blocksize;
1539 journal->j_dev = bdev;
1540 journal->j_fs_dev = fs_dev;
1541 journal->j_blk_offset = start;
1542 journal->j_total_len = len;
1543 jbd2_init_fs_dev_write_error(journal);
1544
1545 err = journal_load_superblock(journal);
1546 if (err)
1547 goto err_cleanup;
1548
1549 init_waitqueue_head(&journal->j_wait_transaction_locked);
1550 init_waitqueue_head(&journal->j_wait_done_commit);
1551 init_waitqueue_head(&journal->j_wait_commit);
1552 init_waitqueue_head(&journal->j_wait_updates);
1553 init_waitqueue_head(&journal->j_wait_reserved);
1554 init_waitqueue_head(&journal->j_fc_wait);
1555 mutex_init(&journal->j_abort_mutex);
1556 mutex_init(&journal->j_barrier);
1557 mutex_init(&journal->j_checkpoint_mutex);
1558 spin_lock_init(&journal->j_revoke_lock);
1559 spin_lock_init(&journal->j_list_lock);
1560 spin_lock_init(&journal->j_history_lock);
1561 rwlock_init(&journal->j_state_lock);
1562
1563 journal->j_commit_interval = (HZ * JBD2_DEFAULT_MAX_COMMIT_AGE);
1564 journal->j_min_batch_time = 0;
1565 journal->j_max_batch_time = 15000; /* 15ms */
1566 atomic_set(&journal->j_reserved_credits, 0);
1567 lockdep_init_map(&journal->j_trans_commit_map, "jbd2_handle",
1568 &jbd2_trans_commit_key, 0);
1569
1570 /* The journal is marked for error until we succeed with recovery! */
1571 journal->j_flags = JBD2_ABORT;
1572
1573 /* Set up a default-sized revoke table for the new mount. */
1574 err = jbd2_journal_init_revoke(journal, JOURNAL_REVOKE_DEFAULT_HASH);
1575 if (err)
1576 goto err_cleanup;
1577
1578 /*
1579 * journal descriptor can store up to n blocks, we need enough
1580 * buffers to write out full descriptor block.
1581 */
1582 err = -ENOMEM;
1583 n = journal->j_blocksize / jbd2_min_tag_size();
1584 journal->j_wbufsize = n;
1585 journal->j_fc_wbuf = NULL;
1586 journal->j_wbuf = kmalloc_array(n, sizeof(struct buffer_head *),
1587 GFP_KERNEL);
1588 if (!journal->j_wbuf)
1589 goto err_cleanup;
1590
1591 err = percpu_counter_init(&journal->j_checkpoint_jh_count, 0,
1592 GFP_KERNEL);
1593 if (err)
1594 goto err_cleanup;
1595
1596 journal->j_shrink_transaction = NULL;
1597
1598 journal->j_shrinker = shrinker_alloc(0, "jbd2-journal:(%u:%u)",
1599 MAJOR(bdev->bd_dev),
1600 MINOR(bdev->bd_dev));
1601 if (!journal->j_shrinker) {
1602 err = -ENOMEM;
1603 goto err_cleanup;
1604 }
1605
1606 journal->j_shrinker->scan_objects = jbd2_journal_shrink_scan;
1607 journal->j_shrinker->count_objects = jbd2_journal_shrink_count;
1608 journal->j_shrinker->private_data = journal;
1609
1610 shrinker_register(journal->j_shrinker);
1611
1612 return journal;
1613
1614 err_cleanup:
1615 percpu_counter_destroy(&journal->j_checkpoint_jh_count);
1616 if (journal->j_chksum_driver)
1617 crypto_free_shash(journal->j_chksum_driver);
1618 kfree(journal->j_wbuf);
1619 jbd2_journal_destroy_revoke(journal);
1620 journal_fail_superblock(journal);
1621 kfree(journal);
1622 return ERR_PTR(err);
1623 }
1624
1625 /* jbd2_journal_init_dev and jbd2_journal_init_inode:
1626 *
1627 * Create a journal structure assigned some fixed set of disk blocks to
1628 * the journal. We don't actually touch those disk blocks yet, but we
1629 * need to set up all of the mapping information to tell the journaling
1630 * system where the journal blocks are.
1631 *
1632 */
1633
1634 /**
1635 * journal_t * jbd2_journal_init_dev() - creates and initialises a journal structure
1636 * @bdev: Block device on which to create the journal
1637 * @fs_dev: Device which hold journalled filesystem for this journal.
1638 * @start: Block nr Start of journal.
1639 * @len: Length of the journal in blocks.
1640 * @blocksize: blocksize of journalling device
1641 *
1642 * Returns: a newly created journal_t *
1643 *
1644 * jbd2_journal_init_dev creates a journal which maps a fixed contiguous
1645 * range of blocks on an arbitrary block device.
1646 *
1647 */
jbd2_journal_init_dev(struct block_device * bdev,struct block_device * fs_dev,unsigned long long start,int len,int blocksize)1648 journal_t *jbd2_journal_init_dev(struct block_device *bdev,
1649 struct block_device *fs_dev,
1650 unsigned long long start, int len, int blocksize)
1651 {
1652 journal_t *journal;
1653
1654 journal = journal_init_common(bdev, fs_dev, start, len, blocksize);
1655 if (IS_ERR(journal))
1656 return ERR_CAST(journal);
1657
1658 snprintf(journal->j_devname, sizeof(journal->j_devname),
1659 "%pg", journal->j_dev);
1660 strreplace(journal->j_devname, '/', '!');
1661 jbd2_stats_proc_init(journal);
1662
1663 return journal;
1664 }
1665
1666 /**
1667 * journal_t * jbd2_journal_init_inode () - creates a journal which maps to a inode.
1668 * @inode: An inode to create the journal in
1669 *
1670 * jbd2_journal_init_inode creates a journal which maps an on-disk inode as
1671 * the journal. The inode must exist already, must support bmap() and
1672 * must have all data blocks preallocated.
1673 */
jbd2_journal_init_inode(struct inode * inode)1674 journal_t *jbd2_journal_init_inode(struct inode *inode)
1675 {
1676 journal_t *journal;
1677 sector_t blocknr;
1678 int err = 0;
1679
1680 blocknr = 0;
1681 err = bmap(inode, &blocknr);
1682 if (err || !blocknr) {
1683 pr_err("%s: Cannot locate journal superblock\n", __func__);
1684 return err ? ERR_PTR(err) : ERR_PTR(-EINVAL);
1685 }
1686
1687 jbd2_debug(1, "JBD2: inode %s/%ld, size %lld, bits %d, blksize %ld\n",
1688 inode->i_sb->s_id, inode->i_ino, (long long) inode->i_size,
1689 inode->i_sb->s_blocksize_bits, inode->i_sb->s_blocksize);
1690
1691 journal = journal_init_common(inode->i_sb->s_bdev, inode->i_sb->s_bdev,
1692 blocknr, inode->i_size >> inode->i_sb->s_blocksize_bits,
1693 inode->i_sb->s_blocksize);
1694 if (IS_ERR(journal))
1695 return ERR_CAST(journal);
1696
1697 journal->j_inode = inode;
1698 snprintf(journal->j_devname, sizeof(journal->j_devname),
1699 "%pg-%lu", journal->j_dev, journal->j_inode->i_ino);
1700 strreplace(journal->j_devname, '/', '!');
1701 jbd2_stats_proc_init(journal);
1702
1703 return journal;
1704 }
1705
1706 /*
1707 * Given a journal_t structure, initialise the various fields for
1708 * startup of a new journaling session. We use this both when creating
1709 * a journal, and after recovering an old journal to reset it for
1710 * subsequent use.
1711 */
1712
journal_reset(journal_t * journal)1713 static int journal_reset(journal_t *journal)
1714 {
1715 journal_superblock_t *sb = journal->j_superblock;
1716 unsigned long long first, last;
1717
1718 first = be32_to_cpu(sb->s_first);
1719 last = be32_to_cpu(sb->s_maxlen);
1720 if (first + JBD2_MIN_JOURNAL_BLOCKS > last + 1) {
1721 printk(KERN_ERR "JBD2: Journal too short (blocks %llu-%llu).\n",
1722 first, last);
1723 journal_fail_superblock(journal);
1724 return -EINVAL;
1725 }
1726
1727 journal->j_first = first;
1728 journal->j_last = last;
1729
1730 if (journal->j_head != 0 && journal->j_flags & JBD2_CYCLE_RECORD) {
1731 /*
1732 * Disable the cycled recording mode if the journal head block
1733 * number is not correct.
1734 */
1735 if (journal->j_head < first || journal->j_head >= last) {
1736 printk(KERN_WARNING "JBD2: Incorrect Journal head block %lu, "
1737 "disable journal_cycle_record\n",
1738 journal->j_head);
1739 journal->j_head = journal->j_first;
1740 }
1741 } else {
1742 journal->j_head = journal->j_first;
1743 }
1744 journal->j_tail = journal->j_head;
1745 journal->j_free = journal->j_last - journal->j_first;
1746
1747 journal->j_tail_sequence = journal->j_transaction_sequence;
1748 journal->j_commit_sequence = journal->j_transaction_sequence - 1;
1749 journal->j_commit_request = journal->j_commit_sequence;
1750
1751 /*
1752 * Now that journal recovery is done, turn fast commits off here. This
1753 * way, if fast commit was enabled before the crash but if now FS has
1754 * disabled it, we don't enable fast commits.
1755 */
1756 jbd2_clear_feature_fast_commit(journal);
1757
1758 /*
1759 * As a special case, if the on-disk copy is already marked as needing
1760 * no recovery (s_start == 0), then we can safely defer the superblock
1761 * update until the next commit by setting JBD2_FLUSHED. This avoids
1762 * attempting a write to a potential-readonly device.
1763 */
1764 if (sb->s_start == 0) {
1765 jbd2_debug(1, "JBD2: Skipping superblock update on recovered sb "
1766 "(start %ld, seq %u, errno %d)\n",
1767 journal->j_tail, journal->j_tail_sequence,
1768 journal->j_errno);
1769 journal->j_flags |= JBD2_FLUSHED;
1770 } else {
1771 /* Lock here to make assertions happy... */
1772 mutex_lock_io(&journal->j_checkpoint_mutex);
1773 /*
1774 * Update log tail information. We use REQ_FUA since new
1775 * transaction will start reusing journal space and so we
1776 * must make sure information about current log tail is on
1777 * disk before that.
1778 */
1779 jbd2_journal_update_sb_log_tail(journal,
1780 journal->j_tail_sequence,
1781 journal->j_tail, REQ_FUA);
1782 mutex_unlock(&journal->j_checkpoint_mutex);
1783 }
1784 return jbd2_journal_start_thread(journal);
1785 }
1786
1787 /*
1788 * This function expects that the caller will have locked the journal
1789 * buffer head, and will return with it unlocked
1790 */
jbd2_write_superblock(journal_t * journal,blk_opf_t write_flags)1791 static int jbd2_write_superblock(journal_t *journal, blk_opf_t write_flags)
1792 {
1793 struct buffer_head *bh = journal->j_sb_buffer;
1794 journal_superblock_t *sb = journal->j_superblock;
1795 int ret = 0;
1796
1797 /* Buffer got discarded which means block device got invalidated */
1798 if (!buffer_mapped(bh)) {
1799 unlock_buffer(bh);
1800 return -EIO;
1801 }
1802
1803 /*
1804 * Always set high priority flags to exempt from block layer's
1805 * QOS policies, e.g. writeback throttle.
1806 */
1807 write_flags |= JBD2_JOURNAL_REQ_FLAGS;
1808 if (!(journal->j_flags & JBD2_BARRIER))
1809 write_flags &= ~(REQ_FUA | REQ_PREFLUSH);
1810
1811 trace_jbd2_write_superblock(journal, write_flags);
1812
1813 if (buffer_write_io_error(bh)) {
1814 /*
1815 * Oh, dear. A previous attempt to write the journal
1816 * superblock failed. This could happen because the
1817 * USB device was yanked out. Or it could happen to
1818 * be a transient write error and maybe the block will
1819 * be remapped. Nothing we can do but to retry the
1820 * write and hope for the best.
1821 */
1822 printk(KERN_ERR "JBD2: previous I/O error detected "
1823 "for journal superblock update for %s.\n",
1824 journal->j_devname);
1825 clear_buffer_write_io_error(bh);
1826 set_buffer_uptodate(bh);
1827 }
1828 if (jbd2_journal_has_csum_v2or3(journal))
1829 sb->s_checksum = jbd2_superblock_csum(journal, sb);
1830 get_bh(bh);
1831 bh->b_end_io = end_buffer_write_sync;
1832 submit_bh(REQ_OP_WRITE | write_flags, bh);
1833 wait_on_buffer(bh);
1834 if (buffer_write_io_error(bh)) {
1835 clear_buffer_write_io_error(bh);
1836 set_buffer_uptodate(bh);
1837 ret = -EIO;
1838 }
1839 if (ret) {
1840 printk(KERN_ERR "JBD2: I/O error when updating journal superblock for %s.\n",
1841 journal->j_devname);
1842 if (!is_journal_aborted(journal))
1843 jbd2_journal_abort(journal, ret);
1844 }
1845
1846 return ret;
1847 }
1848
1849 /**
1850 * jbd2_journal_update_sb_log_tail() - Update log tail in journal sb on disk.
1851 * @journal: The journal to update.
1852 * @tail_tid: TID of the new transaction at the tail of the log
1853 * @tail_block: The first block of the transaction at the tail of the log
1854 * @write_flags: Flags for the journal sb write operation
1855 *
1856 * Update a journal's superblock information about log tail and write it to
1857 * disk, waiting for the IO to complete.
1858 */
jbd2_journal_update_sb_log_tail(journal_t * journal,tid_t tail_tid,unsigned long tail_block,blk_opf_t write_flags)1859 int jbd2_journal_update_sb_log_tail(journal_t *journal, tid_t tail_tid,
1860 unsigned long tail_block,
1861 blk_opf_t write_flags)
1862 {
1863 journal_superblock_t *sb = journal->j_superblock;
1864 int ret;
1865
1866 if (is_journal_aborted(journal))
1867 return -EIO;
1868 if (jbd2_check_fs_dev_write_error(journal)) {
1869 jbd2_journal_abort(journal, -EIO);
1870 return -EIO;
1871 }
1872
1873 BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
1874 jbd2_debug(1, "JBD2: updating superblock (start %lu, seq %u)\n",
1875 tail_block, tail_tid);
1876
1877 lock_buffer(journal->j_sb_buffer);
1878 sb->s_sequence = cpu_to_be32(tail_tid);
1879 sb->s_start = cpu_to_be32(tail_block);
1880
1881 ret = jbd2_write_superblock(journal, write_flags);
1882 if (ret)
1883 goto out;
1884
1885 /* Log is no longer empty */
1886 write_lock(&journal->j_state_lock);
1887 WARN_ON(!sb->s_sequence);
1888 journal->j_flags &= ~JBD2_FLUSHED;
1889 write_unlock(&journal->j_state_lock);
1890
1891 out:
1892 return ret;
1893 }
1894
1895 /**
1896 * jbd2_mark_journal_empty() - Mark on disk journal as empty.
1897 * @journal: The journal to update.
1898 * @write_flags: Flags for the journal sb write operation
1899 *
1900 * Update a journal's dynamic superblock fields to show that journal is empty.
1901 * Write updated superblock to disk waiting for IO to complete.
1902 */
jbd2_mark_journal_empty(journal_t * journal,blk_opf_t write_flags)1903 static void jbd2_mark_journal_empty(journal_t *journal, blk_opf_t write_flags)
1904 {
1905 journal_superblock_t *sb = journal->j_superblock;
1906 bool had_fast_commit = false;
1907
1908 BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
1909 lock_buffer(journal->j_sb_buffer);
1910 if (sb->s_start == 0) { /* Is it already empty? */
1911 unlock_buffer(journal->j_sb_buffer);
1912 return;
1913 }
1914
1915 jbd2_debug(1, "JBD2: Marking journal as empty (seq %u)\n",
1916 journal->j_tail_sequence);
1917
1918 sb->s_sequence = cpu_to_be32(journal->j_tail_sequence);
1919 sb->s_start = cpu_to_be32(0);
1920 sb->s_head = cpu_to_be32(journal->j_head);
1921 if (jbd2_has_feature_fast_commit(journal)) {
1922 /*
1923 * When journal is clean, no need to commit fast commit flag and
1924 * make file system incompatible with older kernels.
1925 */
1926 jbd2_clear_feature_fast_commit(journal);
1927 had_fast_commit = true;
1928 }
1929
1930 jbd2_write_superblock(journal, write_flags);
1931
1932 if (had_fast_commit)
1933 jbd2_set_feature_fast_commit(journal);
1934
1935 /* Log is empty */
1936 write_lock(&journal->j_state_lock);
1937 journal->j_flags |= JBD2_FLUSHED;
1938 write_unlock(&journal->j_state_lock);
1939 }
1940
1941 /**
1942 * __jbd2_journal_erase() - Discard or zeroout journal blocks (excluding superblock)
1943 * @journal: The journal to erase.
1944 * @flags: A discard/zeroout request is sent for each physically contigous
1945 * region of the journal. Either JBD2_JOURNAL_FLUSH_DISCARD or
1946 * JBD2_JOURNAL_FLUSH_ZEROOUT must be set to determine which operation
1947 * to perform.
1948 *
1949 * Note: JBD2_JOURNAL_FLUSH_ZEROOUT attempts to use hardware offload. Zeroes
1950 * will be explicitly written if no hardware offload is available, see
1951 * blkdev_issue_zeroout for more details.
1952 */
__jbd2_journal_erase(journal_t * journal,unsigned int flags)1953 static int __jbd2_journal_erase(journal_t *journal, unsigned int flags)
1954 {
1955 int err = 0;
1956 unsigned long block, log_offset; /* logical */
1957 unsigned long long phys_block, block_start, block_stop; /* physical */
1958 loff_t byte_start, byte_stop, byte_count;
1959
1960 /* flags must be set to either discard or zeroout */
1961 if ((flags & ~JBD2_JOURNAL_FLUSH_VALID) || !flags ||
1962 ((flags & JBD2_JOURNAL_FLUSH_DISCARD) &&
1963 (flags & JBD2_JOURNAL_FLUSH_ZEROOUT)))
1964 return -EINVAL;
1965
1966 if ((flags & JBD2_JOURNAL_FLUSH_DISCARD) &&
1967 !bdev_max_discard_sectors(journal->j_dev))
1968 return -EOPNOTSUPP;
1969
1970 /*
1971 * lookup block mapping and issue discard/zeroout for each
1972 * contiguous region
1973 */
1974 log_offset = be32_to_cpu(journal->j_superblock->s_first);
1975 block_start = ~0ULL;
1976 for (block = log_offset; block < journal->j_total_len; block++) {
1977 err = jbd2_journal_bmap(journal, block, &phys_block);
1978 if (err) {
1979 pr_err("JBD2: bad block at offset %lu", block);
1980 return err;
1981 }
1982
1983 if (block_start == ~0ULL) {
1984 block_start = phys_block;
1985 block_stop = block_start - 1;
1986 }
1987
1988 /*
1989 * last block not contiguous with current block,
1990 * process last contiguous region and return to this block on
1991 * next loop
1992 */
1993 if (phys_block != block_stop + 1) {
1994 block--;
1995 } else {
1996 block_stop++;
1997 /*
1998 * if this isn't the last block of journal,
1999 * no need to process now because next block may also
2000 * be part of this contiguous region
2001 */
2002 if (block != journal->j_total_len - 1)
2003 continue;
2004 }
2005
2006 /*
2007 * end of contiguous region or this is last block of journal,
2008 * take care of the region
2009 */
2010 byte_start = block_start * journal->j_blocksize;
2011 byte_stop = block_stop * journal->j_blocksize;
2012 byte_count = (block_stop - block_start + 1) *
2013 journal->j_blocksize;
2014
2015 truncate_inode_pages_range(journal->j_dev->bd_mapping,
2016 byte_start, byte_stop);
2017
2018 if (flags & JBD2_JOURNAL_FLUSH_DISCARD) {
2019 err = blkdev_issue_discard(journal->j_dev,
2020 byte_start >> SECTOR_SHIFT,
2021 byte_count >> SECTOR_SHIFT,
2022 GFP_NOFS);
2023 } else if (flags & JBD2_JOURNAL_FLUSH_ZEROOUT) {
2024 err = blkdev_issue_zeroout(journal->j_dev,
2025 byte_start >> SECTOR_SHIFT,
2026 byte_count >> SECTOR_SHIFT,
2027 GFP_NOFS, 0);
2028 }
2029
2030 if (unlikely(err != 0)) {
2031 pr_err("JBD2: (error %d) unable to wipe journal at physical blocks %llu - %llu",
2032 err, block_start, block_stop);
2033 return err;
2034 }
2035
2036 /* reset start and stop after processing a region */
2037 block_start = ~0ULL;
2038 }
2039
2040 return blkdev_issue_flush(journal->j_dev);
2041 }
2042
2043 /**
2044 * jbd2_journal_update_sb_errno() - Update error in the journal.
2045 * @journal: The journal to update.
2046 *
2047 * Update a journal's errno. Write updated superblock to disk waiting for IO
2048 * to complete.
2049 */
jbd2_journal_update_sb_errno(journal_t * journal)2050 void jbd2_journal_update_sb_errno(journal_t *journal)
2051 {
2052 journal_superblock_t *sb = journal->j_superblock;
2053 int errcode;
2054
2055 lock_buffer(journal->j_sb_buffer);
2056 errcode = journal->j_errno;
2057 if (errcode == -ESHUTDOWN)
2058 errcode = 0;
2059 jbd2_debug(1, "JBD2: updating superblock error (errno %d)\n", errcode);
2060 sb->s_errno = cpu_to_be32(errcode);
2061
2062 jbd2_write_superblock(journal, REQ_FUA);
2063 }
2064 EXPORT_SYMBOL(jbd2_journal_update_sb_errno);
2065
2066 /**
2067 * jbd2_journal_load() - Read journal from disk.
2068 * @journal: Journal to act on.
2069 *
2070 * Given a journal_t structure which tells us which disk blocks contain
2071 * a journal, read the journal from disk to initialise the in-memory
2072 * structures.
2073 */
jbd2_journal_load(journal_t * journal)2074 int jbd2_journal_load(journal_t *journal)
2075 {
2076 int err;
2077 journal_superblock_t *sb = journal->j_superblock;
2078
2079 /*
2080 * Create a slab for this blocksize
2081 */
2082 err = jbd2_journal_create_slab(be32_to_cpu(sb->s_blocksize));
2083 if (err)
2084 return err;
2085
2086 /* Let the recovery code check whether it needs to recover any
2087 * data from the journal. */
2088 err = jbd2_journal_recover(journal);
2089 if (err) {
2090 pr_warn("JBD2: journal recovery failed\n");
2091 return err;
2092 }
2093
2094 if (journal->j_failed_commit) {
2095 printk(KERN_ERR "JBD2: journal transaction %u on %s "
2096 "is corrupt.\n", journal->j_failed_commit,
2097 journal->j_devname);
2098 return -EFSCORRUPTED;
2099 }
2100 /*
2101 * clear JBD2_ABORT flag initialized in journal_init_common
2102 * here to update log tail information with the newest seq.
2103 */
2104 journal->j_flags &= ~JBD2_ABORT;
2105
2106 /* OK, we've finished with the dynamic journal bits:
2107 * reinitialise the dynamic contents of the superblock in memory
2108 * and reset them on disk. */
2109 err = journal_reset(journal);
2110 if (err) {
2111 pr_warn("JBD2: journal reset failed\n");
2112 return err;
2113 }
2114
2115 journal->j_flags |= JBD2_LOADED;
2116 return 0;
2117 }
2118
2119 /**
2120 * jbd2_journal_destroy() - Release a journal_t structure.
2121 * @journal: Journal to act on.
2122 *
2123 * Release a journal_t structure once it is no longer in use by the
2124 * journaled object.
2125 * Return <0 if we couldn't clean up the journal.
2126 */
jbd2_journal_destroy(journal_t * journal)2127 int jbd2_journal_destroy(journal_t *journal)
2128 {
2129 int err = 0;
2130
2131 /* Wait for the commit thread to wake up and die. */
2132 journal_kill_thread(journal);
2133
2134 /* Force a final log commit */
2135 if (journal->j_running_transaction)
2136 jbd2_journal_commit_transaction(journal);
2137
2138 /* Force any old transactions to disk */
2139
2140 /* Totally anal locking here... */
2141 spin_lock(&journal->j_list_lock);
2142 while (journal->j_checkpoint_transactions != NULL) {
2143 spin_unlock(&journal->j_list_lock);
2144 mutex_lock_io(&journal->j_checkpoint_mutex);
2145 err = jbd2_log_do_checkpoint(journal);
2146 mutex_unlock(&journal->j_checkpoint_mutex);
2147 /*
2148 * If checkpointing failed, just free the buffers to avoid
2149 * looping forever
2150 */
2151 if (err) {
2152 jbd2_journal_destroy_checkpoint(journal);
2153 spin_lock(&journal->j_list_lock);
2154 break;
2155 }
2156 spin_lock(&journal->j_list_lock);
2157 }
2158
2159 J_ASSERT(journal->j_running_transaction == NULL);
2160 J_ASSERT(journal->j_committing_transaction == NULL);
2161 J_ASSERT(journal->j_checkpoint_transactions == NULL);
2162 spin_unlock(&journal->j_list_lock);
2163
2164 /*
2165 * OK, all checkpoint transactions have been checked, now check the
2166 * writeback errseq of fs dev and abort the journal if some buffer
2167 * failed to write back to the original location, otherwise the
2168 * filesystem may become inconsistent.
2169 */
2170 if (!is_journal_aborted(journal) &&
2171 jbd2_check_fs_dev_write_error(journal))
2172 jbd2_journal_abort(journal, -EIO);
2173
2174 if (journal->j_sb_buffer) {
2175 if (!is_journal_aborted(journal)) {
2176 mutex_lock_io(&journal->j_checkpoint_mutex);
2177
2178 write_lock(&journal->j_state_lock);
2179 journal->j_tail_sequence =
2180 ++journal->j_transaction_sequence;
2181 write_unlock(&journal->j_state_lock);
2182
2183 jbd2_mark_journal_empty(journal, REQ_PREFLUSH | REQ_FUA);
2184 mutex_unlock(&journal->j_checkpoint_mutex);
2185 } else
2186 err = -EIO;
2187 brelse(journal->j_sb_buffer);
2188 }
2189
2190 if (journal->j_shrinker) {
2191 percpu_counter_destroy(&journal->j_checkpoint_jh_count);
2192 shrinker_free(journal->j_shrinker);
2193 }
2194 if (journal->j_proc_entry)
2195 jbd2_stats_proc_exit(journal);
2196 iput(journal->j_inode);
2197 if (journal->j_revoke)
2198 jbd2_journal_destroy_revoke(journal);
2199 if (journal->j_chksum_driver)
2200 crypto_free_shash(journal->j_chksum_driver);
2201 kfree(journal->j_fc_wbuf);
2202 kfree(journal->j_wbuf);
2203 kfree(journal);
2204
2205 return err;
2206 }
2207
2208
2209 /**
2210 * jbd2_journal_check_used_features() - Check if features specified are used.
2211 * @journal: Journal to check.
2212 * @compat: bitmask of compatible features
2213 * @ro: bitmask of features that force read-only mount
2214 * @incompat: bitmask of incompatible features
2215 *
2216 * Check whether the journal uses all of a given set of
2217 * features. Return true (non-zero) if it does.
2218 **/
2219
jbd2_journal_check_used_features(journal_t * journal,unsigned long compat,unsigned long ro,unsigned long incompat)2220 int jbd2_journal_check_used_features(journal_t *journal, unsigned long compat,
2221 unsigned long ro, unsigned long incompat)
2222 {
2223 journal_superblock_t *sb;
2224
2225 if (!compat && !ro && !incompat)
2226 return 1;
2227 if (!jbd2_format_support_feature(journal))
2228 return 0;
2229
2230 sb = journal->j_superblock;
2231
2232 if (((be32_to_cpu(sb->s_feature_compat) & compat) == compat) &&
2233 ((be32_to_cpu(sb->s_feature_ro_compat) & ro) == ro) &&
2234 ((be32_to_cpu(sb->s_feature_incompat) & incompat) == incompat))
2235 return 1;
2236
2237 return 0;
2238 }
2239
2240 /**
2241 * jbd2_journal_check_available_features() - Check feature set in journalling layer
2242 * @journal: Journal to check.
2243 * @compat: bitmask of compatible features
2244 * @ro: bitmask of features that force read-only mount
2245 * @incompat: bitmask of incompatible features
2246 *
2247 * Check whether the journaling code supports the use of
2248 * all of a given set of features on this journal. Return true
2249 * (non-zero) if it can. */
2250
jbd2_journal_check_available_features(journal_t * journal,unsigned long compat,unsigned long ro,unsigned long incompat)2251 int jbd2_journal_check_available_features(journal_t *journal, unsigned long compat,
2252 unsigned long ro, unsigned long incompat)
2253 {
2254 if (!compat && !ro && !incompat)
2255 return 1;
2256
2257 if (!jbd2_format_support_feature(journal))
2258 return 0;
2259
2260 if ((compat & JBD2_KNOWN_COMPAT_FEATURES) == compat &&
2261 (ro & JBD2_KNOWN_ROCOMPAT_FEATURES) == ro &&
2262 (incompat & JBD2_KNOWN_INCOMPAT_FEATURES) == incompat)
2263 return 1;
2264
2265 return 0;
2266 }
2267
2268 static int
jbd2_journal_initialize_fast_commit(journal_t * journal)2269 jbd2_journal_initialize_fast_commit(journal_t *journal)
2270 {
2271 journal_superblock_t *sb = journal->j_superblock;
2272 unsigned long long num_fc_blks;
2273
2274 num_fc_blks = jbd2_journal_get_num_fc_blks(sb);
2275 if (journal->j_last - num_fc_blks < JBD2_MIN_JOURNAL_BLOCKS)
2276 return -ENOSPC;
2277
2278 /* Are we called twice? */
2279 WARN_ON(journal->j_fc_wbuf != NULL);
2280 journal->j_fc_wbuf = kmalloc_array(num_fc_blks,
2281 sizeof(struct buffer_head *), GFP_KERNEL);
2282 if (!journal->j_fc_wbuf)
2283 return -ENOMEM;
2284
2285 journal->j_fc_wbufsize = num_fc_blks;
2286 journal->j_fc_last = journal->j_last;
2287 journal->j_last = journal->j_fc_last - num_fc_blks;
2288 journal->j_fc_first = journal->j_last + 1;
2289 journal->j_fc_off = 0;
2290 journal->j_free = journal->j_last - journal->j_first;
2291
2292 return 0;
2293 }
2294
2295 /**
2296 * jbd2_journal_set_features() - Mark a given journal feature in the superblock
2297 * @journal: Journal to act on.
2298 * @compat: bitmask of compatible features
2299 * @ro: bitmask of features that force read-only mount
2300 * @incompat: bitmask of incompatible features
2301 *
2302 * Mark a given journal feature as present on the
2303 * superblock. Returns true if the requested features could be set.
2304 *
2305 */
2306
jbd2_journal_set_features(journal_t * journal,unsigned long compat,unsigned long ro,unsigned long incompat)2307 int jbd2_journal_set_features(journal_t *journal, unsigned long compat,
2308 unsigned long ro, unsigned long incompat)
2309 {
2310 #define INCOMPAT_FEATURE_ON(f) \
2311 ((incompat & (f)) && !(sb->s_feature_incompat & cpu_to_be32(f)))
2312 #define COMPAT_FEATURE_ON(f) \
2313 ((compat & (f)) && !(sb->s_feature_compat & cpu_to_be32(f)))
2314 journal_superblock_t *sb;
2315
2316 if (jbd2_journal_check_used_features(journal, compat, ro, incompat))
2317 return 1;
2318
2319 if (!jbd2_journal_check_available_features(journal, compat, ro, incompat))
2320 return 0;
2321
2322 /* If enabling v2 checksums, turn on v3 instead */
2323 if (incompat & JBD2_FEATURE_INCOMPAT_CSUM_V2) {
2324 incompat &= ~JBD2_FEATURE_INCOMPAT_CSUM_V2;
2325 incompat |= JBD2_FEATURE_INCOMPAT_CSUM_V3;
2326 }
2327
2328 /* Asking for checksumming v3 and v1? Only give them v3. */
2329 if (incompat & JBD2_FEATURE_INCOMPAT_CSUM_V3 &&
2330 compat & JBD2_FEATURE_COMPAT_CHECKSUM)
2331 compat &= ~JBD2_FEATURE_COMPAT_CHECKSUM;
2332
2333 jbd2_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n",
2334 compat, ro, incompat);
2335
2336 sb = journal->j_superblock;
2337
2338 if (incompat & JBD2_FEATURE_INCOMPAT_FAST_COMMIT) {
2339 if (jbd2_journal_initialize_fast_commit(journal)) {
2340 pr_err("JBD2: Cannot enable fast commits.\n");
2341 return 0;
2342 }
2343 }
2344
2345 /* Load the checksum driver if necessary */
2346 if ((journal->j_chksum_driver == NULL) &&
2347 INCOMPAT_FEATURE_ON(JBD2_FEATURE_INCOMPAT_CSUM_V3)) {
2348 journal->j_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
2349 if (IS_ERR(journal->j_chksum_driver)) {
2350 printk(KERN_ERR "JBD2: Cannot load crc32c driver.\n");
2351 journal->j_chksum_driver = NULL;
2352 return 0;
2353 }
2354 /* Precompute checksum seed for all metadata */
2355 journal->j_csum_seed = jbd2_chksum(journal, ~0, sb->s_uuid,
2356 sizeof(sb->s_uuid));
2357 }
2358
2359 lock_buffer(journal->j_sb_buffer);
2360
2361 /* If enabling v3 checksums, update superblock */
2362 if (INCOMPAT_FEATURE_ON(JBD2_FEATURE_INCOMPAT_CSUM_V3)) {
2363 sb->s_checksum_type = JBD2_CRC32C_CHKSUM;
2364 sb->s_feature_compat &=
2365 ~cpu_to_be32(JBD2_FEATURE_COMPAT_CHECKSUM);
2366 }
2367
2368 /* If enabling v1 checksums, downgrade superblock */
2369 if (COMPAT_FEATURE_ON(JBD2_FEATURE_COMPAT_CHECKSUM))
2370 sb->s_feature_incompat &=
2371 ~cpu_to_be32(JBD2_FEATURE_INCOMPAT_CSUM_V2 |
2372 JBD2_FEATURE_INCOMPAT_CSUM_V3);
2373
2374 sb->s_feature_compat |= cpu_to_be32(compat);
2375 sb->s_feature_ro_compat |= cpu_to_be32(ro);
2376 sb->s_feature_incompat |= cpu_to_be32(incompat);
2377 unlock_buffer(journal->j_sb_buffer);
2378 jbd2_journal_init_transaction_limits(journal);
2379
2380 return 1;
2381 #undef COMPAT_FEATURE_ON
2382 #undef INCOMPAT_FEATURE_ON
2383 }
2384
2385 /*
2386 * jbd2_journal_clear_features() - Clear a given journal feature in the
2387 * superblock
2388 * @journal: Journal to act on.
2389 * @compat: bitmask of compatible features
2390 * @ro: bitmask of features that force read-only mount
2391 * @incompat: bitmask of incompatible features
2392 *
2393 * Clear a given journal feature as present on the
2394 * superblock.
2395 */
jbd2_journal_clear_features(journal_t * journal,unsigned long compat,unsigned long ro,unsigned long incompat)2396 void jbd2_journal_clear_features(journal_t *journal, unsigned long compat,
2397 unsigned long ro, unsigned long incompat)
2398 {
2399 journal_superblock_t *sb;
2400
2401 jbd2_debug(1, "Clear features 0x%lx/0x%lx/0x%lx\n",
2402 compat, ro, incompat);
2403
2404 sb = journal->j_superblock;
2405
2406 sb->s_feature_compat &= ~cpu_to_be32(compat);
2407 sb->s_feature_ro_compat &= ~cpu_to_be32(ro);
2408 sb->s_feature_incompat &= ~cpu_to_be32(incompat);
2409 jbd2_journal_init_transaction_limits(journal);
2410 }
2411 EXPORT_SYMBOL(jbd2_journal_clear_features);
2412
2413 /**
2414 * jbd2_journal_flush() - Flush journal
2415 * @journal: Journal to act on.
2416 * @flags: optional operation on the journal blocks after the flush (see below)
2417 *
2418 * Flush all data for a given journal to disk and empty the journal.
2419 * Filesystems can use this when remounting readonly to ensure that
2420 * recovery does not need to happen on remount. Optionally, a discard or zeroout
2421 * can be issued on the journal blocks after flushing.
2422 *
2423 * flags:
2424 * JBD2_JOURNAL_FLUSH_DISCARD: issues discards for the journal blocks
2425 * JBD2_JOURNAL_FLUSH_ZEROOUT: issues zeroouts for the journal blocks
2426 */
jbd2_journal_flush(journal_t * journal,unsigned int flags)2427 int jbd2_journal_flush(journal_t *journal, unsigned int flags)
2428 {
2429 int err = 0;
2430 transaction_t *transaction = NULL;
2431
2432 write_lock(&journal->j_state_lock);
2433
2434 /* Force everything buffered to the log... */
2435 if (journal->j_running_transaction) {
2436 transaction = journal->j_running_transaction;
2437 __jbd2_log_start_commit(journal, transaction->t_tid);
2438 } else if (journal->j_committing_transaction)
2439 transaction = journal->j_committing_transaction;
2440
2441 /* Wait for the log commit to complete... */
2442 if (transaction) {
2443 tid_t tid = transaction->t_tid;
2444
2445 write_unlock(&journal->j_state_lock);
2446 jbd2_log_wait_commit(journal, tid);
2447 } else {
2448 write_unlock(&journal->j_state_lock);
2449 }
2450
2451 /* ...and flush everything in the log out to disk. */
2452 spin_lock(&journal->j_list_lock);
2453 while (!err && journal->j_checkpoint_transactions != NULL) {
2454 spin_unlock(&journal->j_list_lock);
2455 mutex_lock_io(&journal->j_checkpoint_mutex);
2456 err = jbd2_log_do_checkpoint(journal);
2457 mutex_unlock(&journal->j_checkpoint_mutex);
2458 spin_lock(&journal->j_list_lock);
2459 }
2460 spin_unlock(&journal->j_list_lock);
2461
2462 if (is_journal_aborted(journal))
2463 return -EIO;
2464
2465 mutex_lock_io(&journal->j_checkpoint_mutex);
2466 if (!err) {
2467 err = jbd2_cleanup_journal_tail(journal);
2468 if (err < 0) {
2469 mutex_unlock(&journal->j_checkpoint_mutex);
2470 goto out;
2471 }
2472 err = 0;
2473 }
2474
2475 /* Finally, mark the journal as really needing no recovery.
2476 * This sets s_start==0 in the underlying superblock, which is
2477 * the magic code for a fully-recovered superblock. Any future
2478 * commits of data to the journal will restore the current
2479 * s_start value. */
2480 jbd2_mark_journal_empty(journal, REQ_FUA);
2481
2482 if (flags)
2483 err = __jbd2_journal_erase(journal, flags);
2484
2485 mutex_unlock(&journal->j_checkpoint_mutex);
2486 write_lock(&journal->j_state_lock);
2487 J_ASSERT(!journal->j_running_transaction);
2488 J_ASSERT(!journal->j_committing_transaction);
2489 J_ASSERT(!journal->j_checkpoint_transactions);
2490 J_ASSERT(journal->j_head == journal->j_tail);
2491 J_ASSERT(journal->j_tail_sequence == journal->j_transaction_sequence);
2492 write_unlock(&journal->j_state_lock);
2493 out:
2494 return err;
2495 }
2496
2497 /**
2498 * jbd2_journal_wipe() - Wipe journal contents
2499 * @journal: Journal to act on.
2500 * @write: flag (see below)
2501 *
2502 * Wipe out all of the contents of a journal, safely. This will produce
2503 * a warning if the journal contains any valid recovery information.
2504 * Must be called between journal_init_*() and jbd2_journal_load().
2505 *
2506 * If 'write' is non-zero, then we wipe out the journal on disk; otherwise
2507 * we merely suppress recovery.
2508 */
2509
jbd2_journal_wipe(journal_t * journal,int write)2510 int jbd2_journal_wipe(journal_t *journal, int write)
2511 {
2512 int err;
2513
2514 J_ASSERT (!(journal->j_flags & JBD2_LOADED));
2515
2516 if (!journal->j_tail)
2517 return 0;
2518
2519 printk(KERN_WARNING "JBD2: %s recovery information on journal\n",
2520 write ? "Clearing" : "Ignoring");
2521
2522 err = jbd2_journal_skip_recovery(journal);
2523 if (write) {
2524 /* Lock to make assertions happy... */
2525 mutex_lock_io(&journal->j_checkpoint_mutex);
2526 jbd2_mark_journal_empty(journal, REQ_FUA);
2527 mutex_unlock(&journal->j_checkpoint_mutex);
2528 }
2529
2530 return err;
2531 }
2532
2533 /**
2534 * jbd2_journal_abort () - Shutdown the journal immediately.
2535 * @journal: the journal to shutdown.
2536 * @errno: an error number to record in the journal indicating
2537 * the reason for the shutdown.
2538 *
2539 * Perform a complete, immediate shutdown of the ENTIRE
2540 * journal (not of a single transaction). This operation cannot be
2541 * undone without closing and reopening the journal.
2542 *
2543 * The jbd2_journal_abort function is intended to support higher level error
2544 * recovery mechanisms such as the ext2/ext3 remount-readonly error
2545 * mode.
2546 *
2547 * Journal abort has very specific semantics. Any existing dirty,
2548 * unjournaled buffers in the main filesystem will still be written to
2549 * disk by bdflush, but the journaling mechanism will be suspended
2550 * immediately and no further transaction commits will be honoured.
2551 *
2552 * Any dirty, journaled buffers will be written back to disk without
2553 * hitting the journal. Atomicity cannot be guaranteed on an aborted
2554 * filesystem, but we _do_ attempt to leave as much data as possible
2555 * behind for fsck to use for cleanup.
2556 *
2557 * Any attempt to get a new transaction handle on a journal which is in
2558 * ABORT state will just result in an -EROFS error return. A
2559 * jbd2_journal_stop on an existing handle will return -EIO if we have
2560 * entered abort state during the update.
2561 *
2562 * Recursive transactions are not disturbed by journal abort until the
2563 * final jbd2_journal_stop, which will receive the -EIO error.
2564 *
2565 * Finally, the jbd2_journal_abort call allows the caller to supply an errno
2566 * which will be recorded (if possible) in the journal superblock. This
2567 * allows a client to record failure conditions in the middle of a
2568 * transaction without having to complete the transaction to record the
2569 * failure to disk. ext3_error, for example, now uses this
2570 * functionality.
2571 *
2572 */
2573
jbd2_journal_abort(journal_t * journal,int errno)2574 void jbd2_journal_abort(journal_t *journal, int errno)
2575 {
2576 transaction_t *transaction;
2577
2578 /*
2579 * Lock the aborting procedure until everything is done, this avoid
2580 * races between filesystem's error handling flow (e.g. ext4_abort()),
2581 * ensure panic after the error info is written into journal's
2582 * superblock.
2583 */
2584 mutex_lock(&journal->j_abort_mutex);
2585 /*
2586 * ESHUTDOWN always takes precedence because a file system check
2587 * caused by any other journal abort error is not required after
2588 * a shutdown triggered.
2589 */
2590 write_lock(&journal->j_state_lock);
2591 if (journal->j_flags & JBD2_ABORT) {
2592 int old_errno = journal->j_errno;
2593
2594 write_unlock(&journal->j_state_lock);
2595 if (old_errno != -ESHUTDOWN && errno == -ESHUTDOWN) {
2596 journal->j_errno = errno;
2597 jbd2_journal_update_sb_errno(journal);
2598 }
2599 mutex_unlock(&journal->j_abort_mutex);
2600 return;
2601 }
2602
2603 /*
2604 * Mark the abort as occurred and start current running transaction
2605 * to release all journaled buffer.
2606 */
2607 pr_err("Aborting journal on device %s.\n", journal->j_devname);
2608
2609 journal->j_flags |= JBD2_ABORT;
2610 journal->j_errno = errno;
2611 transaction = journal->j_running_transaction;
2612 if (transaction)
2613 __jbd2_log_start_commit(journal, transaction->t_tid);
2614 write_unlock(&journal->j_state_lock);
2615
2616 /*
2617 * Record errno to the journal super block, so that fsck and jbd2
2618 * layer could realise that a filesystem check is needed.
2619 */
2620 jbd2_journal_update_sb_errno(journal);
2621 mutex_unlock(&journal->j_abort_mutex);
2622 }
2623
2624 /**
2625 * jbd2_journal_errno() - returns the journal's error state.
2626 * @journal: journal to examine.
2627 *
2628 * This is the errno number set with jbd2_journal_abort(), the last
2629 * time the journal was mounted - if the journal was stopped
2630 * without calling abort this will be 0.
2631 *
2632 * If the journal has been aborted on this mount time -EROFS will
2633 * be returned.
2634 */
jbd2_journal_errno(journal_t * journal)2635 int jbd2_journal_errno(journal_t *journal)
2636 {
2637 int err;
2638
2639 read_lock(&journal->j_state_lock);
2640 if (journal->j_flags & JBD2_ABORT)
2641 err = -EROFS;
2642 else
2643 err = journal->j_errno;
2644 read_unlock(&journal->j_state_lock);
2645 return err;
2646 }
2647
2648 /**
2649 * jbd2_journal_clear_err() - clears the journal's error state
2650 * @journal: journal to act on.
2651 *
2652 * An error must be cleared or acked to take a FS out of readonly
2653 * mode.
2654 */
jbd2_journal_clear_err(journal_t * journal)2655 int jbd2_journal_clear_err(journal_t *journal)
2656 {
2657 int err = 0;
2658
2659 write_lock(&journal->j_state_lock);
2660 if (journal->j_flags & JBD2_ABORT)
2661 err = -EROFS;
2662 else
2663 journal->j_errno = 0;
2664 write_unlock(&journal->j_state_lock);
2665 return err;
2666 }
2667
2668 /**
2669 * jbd2_journal_ack_err() - Ack journal err.
2670 * @journal: journal to act on.
2671 *
2672 * An error must be cleared or acked to take a FS out of readonly
2673 * mode.
2674 */
jbd2_journal_ack_err(journal_t * journal)2675 void jbd2_journal_ack_err(journal_t *journal)
2676 {
2677 write_lock(&journal->j_state_lock);
2678 if (journal->j_errno)
2679 journal->j_flags |= JBD2_ACK_ERR;
2680 write_unlock(&journal->j_state_lock);
2681 }
2682
jbd2_journal_blocks_per_page(struct inode * inode)2683 int jbd2_journal_blocks_per_page(struct inode *inode)
2684 {
2685 return 1 << (PAGE_SHIFT - inode->i_sb->s_blocksize_bits);
2686 }
2687
2688 /*
2689 * helper functions to deal with 32 or 64bit block numbers.
2690 */
journal_tag_bytes(journal_t * journal)2691 size_t journal_tag_bytes(journal_t *journal)
2692 {
2693 size_t sz;
2694
2695 if (jbd2_has_feature_csum3(journal))
2696 return sizeof(journal_block_tag3_t);
2697
2698 sz = sizeof(journal_block_tag_t);
2699
2700 if (jbd2_has_feature_csum2(journal))
2701 sz += sizeof(__u16);
2702
2703 if (jbd2_has_feature_64bit(journal))
2704 return sz;
2705 else
2706 return sz - sizeof(__u32);
2707 }
2708
2709 /*
2710 * JBD memory management
2711 *
2712 * These functions are used to allocate block-sized chunks of memory
2713 * used for making copies of buffer_head data. Very often it will be
2714 * page-sized chunks of data, but sometimes it will be in
2715 * sub-page-size chunks. (For example, 16k pages on Power systems
2716 * with a 4k block file system.) For blocks smaller than a page, we
2717 * use a SLAB allocator. There are slab caches for each block size,
2718 * which are allocated at mount time, if necessary, and we only free
2719 * (all of) the slab caches when/if the jbd2 module is unloaded. For
2720 * this reason we don't need to a mutex to protect access to
2721 * jbd2_slab[] allocating or releasing memory; only in
2722 * jbd2_journal_create_slab().
2723 */
2724 #define JBD2_MAX_SLABS 8
2725 static struct kmem_cache *jbd2_slab[JBD2_MAX_SLABS];
2726
2727 static const char *jbd2_slab_names[JBD2_MAX_SLABS] = {
2728 "jbd2_1k", "jbd2_2k", "jbd2_4k", "jbd2_8k",
2729 "jbd2_16k", "jbd2_32k", "jbd2_64k", "jbd2_128k"
2730 };
2731
2732
jbd2_journal_destroy_slabs(void)2733 static void jbd2_journal_destroy_slabs(void)
2734 {
2735 int i;
2736
2737 for (i = 0; i < JBD2_MAX_SLABS; i++) {
2738 kmem_cache_destroy(jbd2_slab[i]);
2739 jbd2_slab[i] = NULL;
2740 }
2741 }
2742
jbd2_journal_create_slab(size_t size)2743 static int jbd2_journal_create_slab(size_t size)
2744 {
2745 static DEFINE_MUTEX(jbd2_slab_create_mutex);
2746 int i = order_base_2(size) - 10;
2747 size_t slab_size;
2748
2749 if (size == PAGE_SIZE)
2750 return 0;
2751
2752 if (i >= JBD2_MAX_SLABS)
2753 return -EINVAL;
2754
2755 if (unlikely(i < 0))
2756 i = 0;
2757 mutex_lock(&jbd2_slab_create_mutex);
2758 if (jbd2_slab[i]) {
2759 mutex_unlock(&jbd2_slab_create_mutex);
2760 return 0; /* Already created */
2761 }
2762
2763 slab_size = 1 << (i+10);
2764 jbd2_slab[i] = kmem_cache_create(jbd2_slab_names[i], slab_size,
2765 slab_size, 0, NULL);
2766 mutex_unlock(&jbd2_slab_create_mutex);
2767 if (!jbd2_slab[i]) {
2768 printk(KERN_EMERG "JBD2: no memory for jbd2_slab cache\n");
2769 return -ENOMEM;
2770 }
2771 return 0;
2772 }
2773
get_slab(size_t size)2774 static struct kmem_cache *get_slab(size_t size)
2775 {
2776 int i = order_base_2(size) - 10;
2777
2778 BUG_ON(i >= JBD2_MAX_SLABS);
2779 if (unlikely(i < 0))
2780 i = 0;
2781 BUG_ON(jbd2_slab[i] == NULL);
2782 return jbd2_slab[i];
2783 }
2784
jbd2_alloc(size_t size,gfp_t flags)2785 void *jbd2_alloc(size_t size, gfp_t flags)
2786 {
2787 void *ptr;
2788
2789 BUG_ON(size & (size-1)); /* Must be a power of 2 */
2790
2791 if (size < PAGE_SIZE)
2792 ptr = kmem_cache_alloc(get_slab(size), flags);
2793 else
2794 ptr = (void *)__get_free_pages(flags, get_order(size));
2795
2796 /* Check alignment; SLUB has gotten this wrong in the past,
2797 * and this can lead to user data corruption! */
2798 BUG_ON(((unsigned long) ptr) & (size-1));
2799
2800 return ptr;
2801 }
2802
jbd2_free(void * ptr,size_t size)2803 void jbd2_free(void *ptr, size_t size)
2804 {
2805 if (size < PAGE_SIZE)
2806 kmem_cache_free(get_slab(size), ptr);
2807 else
2808 free_pages((unsigned long)ptr, get_order(size));
2809 };
2810
2811 /*
2812 * Journal_head storage management
2813 */
2814 static struct kmem_cache *jbd2_journal_head_cache;
2815 #ifdef CONFIG_JBD2_DEBUG
2816 static atomic_t nr_journal_heads = ATOMIC_INIT(0);
2817 #endif
2818
jbd2_journal_init_journal_head_cache(void)2819 static int __init jbd2_journal_init_journal_head_cache(void)
2820 {
2821 J_ASSERT(!jbd2_journal_head_cache);
2822 jbd2_journal_head_cache = kmem_cache_create("jbd2_journal_head",
2823 sizeof(struct journal_head),
2824 0, /* offset */
2825 SLAB_TEMPORARY | SLAB_TYPESAFE_BY_RCU,
2826 NULL); /* ctor */
2827 if (!jbd2_journal_head_cache) {
2828 printk(KERN_EMERG "JBD2: no memory for journal_head cache\n");
2829 return -ENOMEM;
2830 }
2831 return 0;
2832 }
2833
jbd2_journal_destroy_journal_head_cache(void)2834 static void jbd2_journal_destroy_journal_head_cache(void)
2835 {
2836 kmem_cache_destroy(jbd2_journal_head_cache);
2837 jbd2_journal_head_cache = NULL;
2838 }
2839
2840 /*
2841 * journal_head splicing and dicing
2842 */
journal_alloc_journal_head(void)2843 static struct journal_head *journal_alloc_journal_head(void)
2844 {
2845 struct journal_head *ret;
2846
2847 #ifdef CONFIG_JBD2_DEBUG
2848 atomic_inc(&nr_journal_heads);
2849 #endif
2850 ret = kmem_cache_zalloc(jbd2_journal_head_cache, GFP_NOFS);
2851 if (!ret) {
2852 jbd2_debug(1, "out of memory for journal_head\n");
2853 pr_notice_ratelimited("ENOMEM in %s, retrying.\n", __func__);
2854 ret = kmem_cache_zalloc(jbd2_journal_head_cache,
2855 GFP_NOFS | __GFP_NOFAIL);
2856 }
2857 spin_lock_init(&ret->b_state_lock);
2858 return ret;
2859 }
2860
journal_free_journal_head(struct journal_head * jh)2861 static void journal_free_journal_head(struct journal_head *jh)
2862 {
2863 #ifdef CONFIG_JBD2_DEBUG
2864 atomic_dec(&nr_journal_heads);
2865 memset(jh, JBD2_POISON_FREE, sizeof(*jh));
2866 #endif
2867 kmem_cache_free(jbd2_journal_head_cache, jh);
2868 }
2869
2870 /*
2871 * A journal_head is attached to a buffer_head whenever JBD has an
2872 * interest in the buffer.
2873 *
2874 * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit
2875 * is set. This bit is tested in core kernel code where we need to take
2876 * JBD-specific actions. Testing the zeroness of ->b_private is not reliable
2877 * there.
2878 *
2879 * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one.
2880 *
2881 * When a buffer has its BH_JBD bit set it is immune from being released by
2882 * core kernel code, mainly via ->b_count.
2883 *
2884 * A journal_head is detached from its buffer_head when the journal_head's
2885 * b_jcount reaches zero. Running transaction (b_transaction) and checkpoint
2886 * transaction (b_cp_transaction) hold their references to b_jcount.
2887 *
2888 * Various places in the kernel want to attach a journal_head to a buffer_head
2889 * _before_ attaching the journal_head to a transaction. To protect the
2890 * journal_head in this situation, jbd2_journal_add_journal_head elevates the
2891 * journal_head's b_jcount refcount by one. The caller must call
2892 * jbd2_journal_put_journal_head() to undo this.
2893 *
2894 * So the typical usage would be:
2895 *
2896 * (Attach a journal_head if needed. Increments b_jcount)
2897 * struct journal_head *jh = jbd2_journal_add_journal_head(bh);
2898 * ...
2899 * (Get another reference for transaction)
2900 * jbd2_journal_grab_journal_head(bh);
2901 * jh->b_transaction = xxx;
2902 * (Put original reference)
2903 * jbd2_journal_put_journal_head(jh);
2904 */
2905
2906 /*
2907 * Give a buffer_head a journal_head.
2908 *
2909 * May sleep.
2910 */
jbd2_journal_add_journal_head(struct buffer_head * bh)2911 struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh)
2912 {
2913 struct journal_head *jh;
2914 struct journal_head *new_jh = NULL;
2915
2916 repeat:
2917 if (!buffer_jbd(bh))
2918 new_jh = journal_alloc_journal_head();
2919
2920 jbd_lock_bh_journal_head(bh);
2921 if (buffer_jbd(bh)) {
2922 jh = bh2jh(bh);
2923 } else {
2924 J_ASSERT_BH(bh,
2925 (atomic_read(&bh->b_count) > 0) ||
2926 (bh->b_folio && bh->b_folio->mapping));
2927
2928 if (!new_jh) {
2929 jbd_unlock_bh_journal_head(bh);
2930 goto repeat;
2931 }
2932
2933 jh = new_jh;
2934 new_jh = NULL; /* We consumed it */
2935 set_buffer_jbd(bh);
2936 bh->b_private = jh;
2937 jh->b_bh = bh;
2938 get_bh(bh);
2939 BUFFER_TRACE(bh, "added journal_head");
2940 }
2941 jh->b_jcount++;
2942 jbd_unlock_bh_journal_head(bh);
2943 if (new_jh)
2944 journal_free_journal_head(new_jh);
2945 return bh->b_private;
2946 }
2947
2948 /*
2949 * Grab a ref against this buffer_head's journal_head. If it ended up not
2950 * having a journal_head, return NULL
2951 */
jbd2_journal_grab_journal_head(struct buffer_head * bh)2952 struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh)
2953 {
2954 struct journal_head *jh = NULL;
2955
2956 jbd_lock_bh_journal_head(bh);
2957 if (buffer_jbd(bh)) {
2958 jh = bh2jh(bh);
2959 jh->b_jcount++;
2960 }
2961 jbd_unlock_bh_journal_head(bh);
2962 return jh;
2963 }
2964 EXPORT_SYMBOL(jbd2_journal_grab_journal_head);
2965
__journal_remove_journal_head(struct buffer_head * bh)2966 static void __journal_remove_journal_head(struct buffer_head *bh)
2967 {
2968 struct journal_head *jh = bh2jh(bh);
2969
2970 J_ASSERT_JH(jh, jh->b_transaction == NULL);
2971 J_ASSERT_JH(jh, jh->b_next_transaction == NULL);
2972 J_ASSERT_JH(jh, jh->b_cp_transaction == NULL);
2973 J_ASSERT_JH(jh, jh->b_jlist == BJ_None);
2974 J_ASSERT_BH(bh, buffer_jbd(bh));
2975 J_ASSERT_BH(bh, jh2bh(jh) == bh);
2976 BUFFER_TRACE(bh, "remove journal_head");
2977
2978 /* Unlink before dropping the lock */
2979 bh->b_private = NULL;
2980 jh->b_bh = NULL; /* debug, really */
2981 clear_buffer_jbd(bh);
2982 }
2983
journal_release_journal_head(struct journal_head * jh,size_t b_size)2984 static void journal_release_journal_head(struct journal_head *jh, size_t b_size)
2985 {
2986 if (jh->b_frozen_data) {
2987 printk(KERN_WARNING "%s: freeing b_frozen_data\n", __func__);
2988 jbd2_free(jh->b_frozen_data, b_size);
2989 }
2990 if (jh->b_committed_data) {
2991 printk(KERN_WARNING "%s: freeing b_committed_data\n", __func__);
2992 jbd2_free(jh->b_committed_data, b_size);
2993 }
2994 journal_free_journal_head(jh);
2995 }
2996
2997 /*
2998 * Drop a reference on the passed journal_head. If it fell to zero then
2999 * release the journal_head from the buffer_head.
3000 */
jbd2_journal_put_journal_head(struct journal_head * jh)3001 void jbd2_journal_put_journal_head(struct journal_head *jh)
3002 {
3003 struct buffer_head *bh = jh2bh(jh);
3004
3005 jbd_lock_bh_journal_head(bh);
3006 J_ASSERT_JH(jh, jh->b_jcount > 0);
3007 --jh->b_jcount;
3008 if (!jh->b_jcount) {
3009 __journal_remove_journal_head(bh);
3010 jbd_unlock_bh_journal_head(bh);
3011 journal_release_journal_head(jh, bh->b_size);
3012 __brelse(bh);
3013 } else {
3014 jbd_unlock_bh_journal_head(bh);
3015 }
3016 }
3017 EXPORT_SYMBOL(jbd2_journal_put_journal_head);
3018
3019 /*
3020 * Initialize jbd inode head
3021 */
jbd2_journal_init_jbd_inode(struct jbd2_inode * jinode,struct inode * inode)3022 void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode)
3023 {
3024 jinode->i_transaction = NULL;
3025 jinode->i_next_transaction = NULL;
3026 jinode->i_vfs_inode = inode;
3027 jinode->i_flags = 0;
3028 jinode->i_dirty_start = 0;
3029 jinode->i_dirty_end = 0;
3030 INIT_LIST_HEAD(&jinode->i_list);
3031 }
3032
3033 /*
3034 * Function to be called before we start removing inode from memory (i.e.,
3035 * clear_inode() is a fine place to be called from). It removes inode from
3036 * transaction's lists.
3037 */
jbd2_journal_release_jbd_inode(journal_t * journal,struct jbd2_inode * jinode)3038 void jbd2_journal_release_jbd_inode(journal_t *journal,
3039 struct jbd2_inode *jinode)
3040 {
3041 if (!journal)
3042 return;
3043 restart:
3044 spin_lock(&journal->j_list_lock);
3045 /* Is commit writing out inode - we have to wait */
3046 if (jinode->i_flags & JI_COMMIT_RUNNING) {
3047 wait_queue_head_t *wq;
3048 DEFINE_WAIT_BIT(wait, &jinode->i_flags, __JI_COMMIT_RUNNING);
3049 wq = bit_waitqueue(&jinode->i_flags, __JI_COMMIT_RUNNING);
3050 prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE);
3051 spin_unlock(&journal->j_list_lock);
3052 schedule();
3053 finish_wait(wq, &wait.wq_entry);
3054 goto restart;
3055 }
3056
3057 if (jinode->i_transaction) {
3058 list_del(&jinode->i_list);
3059 jinode->i_transaction = NULL;
3060 }
3061 spin_unlock(&journal->j_list_lock);
3062 }
3063
3064
3065 #ifdef CONFIG_PROC_FS
3066
3067 #define JBD2_STATS_PROC_NAME "fs/jbd2"
3068
jbd2_create_jbd_stats_proc_entry(void)3069 static void __init jbd2_create_jbd_stats_proc_entry(void)
3070 {
3071 proc_jbd2_stats = proc_mkdir(JBD2_STATS_PROC_NAME, NULL);
3072 }
3073
jbd2_remove_jbd_stats_proc_entry(void)3074 static void __exit jbd2_remove_jbd_stats_proc_entry(void)
3075 {
3076 if (proc_jbd2_stats)
3077 remove_proc_entry(JBD2_STATS_PROC_NAME, NULL);
3078 }
3079
3080 #else
3081
3082 #define jbd2_create_jbd_stats_proc_entry() do {} while (0)
3083 #define jbd2_remove_jbd_stats_proc_entry() do {} while (0)
3084
3085 #endif
3086
3087 struct kmem_cache *jbd2_handle_cache, *jbd2_inode_cache;
3088
jbd2_journal_init_inode_cache(void)3089 static int __init jbd2_journal_init_inode_cache(void)
3090 {
3091 J_ASSERT(!jbd2_inode_cache);
3092 jbd2_inode_cache = KMEM_CACHE(jbd2_inode, 0);
3093 if (!jbd2_inode_cache) {
3094 pr_emerg("JBD2: failed to create inode cache\n");
3095 return -ENOMEM;
3096 }
3097 return 0;
3098 }
3099
jbd2_journal_init_handle_cache(void)3100 static int __init jbd2_journal_init_handle_cache(void)
3101 {
3102 J_ASSERT(!jbd2_handle_cache);
3103 jbd2_handle_cache = KMEM_CACHE(jbd2_journal_handle, SLAB_TEMPORARY);
3104 if (!jbd2_handle_cache) {
3105 printk(KERN_EMERG "JBD2: failed to create handle cache\n");
3106 return -ENOMEM;
3107 }
3108 return 0;
3109 }
3110
jbd2_journal_destroy_inode_cache(void)3111 static void jbd2_journal_destroy_inode_cache(void)
3112 {
3113 kmem_cache_destroy(jbd2_inode_cache);
3114 jbd2_inode_cache = NULL;
3115 }
3116
jbd2_journal_destroy_handle_cache(void)3117 static void jbd2_journal_destroy_handle_cache(void)
3118 {
3119 kmem_cache_destroy(jbd2_handle_cache);
3120 jbd2_handle_cache = NULL;
3121 }
3122
3123 /*
3124 * Module startup and shutdown
3125 */
3126
journal_init_caches(void)3127 static int __init journal_init_caches(void)
3128 {
3129 int ret;
3130
3131 ret = jbd2_journal_init_revoke_record_cache();
3132 if (ret == 0)
3133 ret = jbd2_journal_init_revoke_table_cache();
3134 if (ret == 0)
3135 ret = jbd2_journal_init_journal_head_cache();
3136 if (ret == 0)
3137 ret = jbd2_journal_init_handle_cache();
3138 if (ret == 0)
3139 ret = jbd2_journal_init_inode_cache();
3140 if (ret == 0)
3141 ret = jbd2_journal_init_transaction_cache();
3142 return ret;
3143 }
3144
jbd2_journal_destroy_caches(void)3145 static void jbd2_journal_destroy_caches(void)
3146 {
3147 jbd2_journal_destroy_revoke_record_cache();
3148 jbd2_journal_destroy_revoke_table_cache();
3149 jbd2_journal_destroy_journal_head_cache();
3150 jbd2_journal_destroy_handle_cache();
3151 jbd2_journal_destroy_inode_cache();
3152 jbd2_journal_destroy_transaction_cache();
3153 jbd2_journal_destroy_slabs();
3154 }
3155
journal_init(void)3156 static int __init journal_init(void)
3157 {
3158 int ret;
3159
3160 BUILD_BUG_ON(sizeof(struct journal_superblock_s) != 1024);
3161
3162 ret = journal_init_caches();
3163 if (ret == 0) {
3164 jbd2_create_jbd_stats_proc_entry();
3165 } else {
3166 jbd2_journal_destroy_caches();
3167 }
3168 return ret;
3169 }
3170
journal_exit(void)3171 static void __exit journal_exit(void)
3172 {
3173 #ifdef CONFIG_JBD2_DEBUG
3174 int n = atomic_read(&nr_journal_heads);
3175 if (n)
3176 printk(KERN_ERR "JBD2: leaked %d journal_heads!\n", n);
3177 #endif
3178 jbd2_remove_jbd_stats_proc_entry();
3179 jbd2_journal_destroy_caches();
3180 }
3181
3182 MODULE_DESCRIPTION("Generic filesystem journal-writing module");
3183 MODULE_LICENSE("GPL");
3184 module_init(journal_init);
3185 module_exit(journal_exit);
3186
3187