blob: 926ebcbf8a7aea8a3ef7a8b455ca4a8e44a430d2 [file] [log] [blame]
Dave Kleikamp470decc2006-10-11 01:20:57 -07001/*
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002 * linux/fs/jbd2/journal.c
Dave Kleikamp470decc2006-10-11 01:20:57 -07003 *
4 * Written by Stephen C. Tweedie <sct@redhat.com>, 1998
5 *
6 * Copyright 1998 Red Hat corp --- All Rights Reserved
7 *
8 * This file is part of the Linux kernel and is made available under
9 * the terms of the GNU General Public License, version 2, or at your
10 * option, any later version, incorporated herein by reference.
11 *
12 * Generic filesystem journal-writing code; part of the ext2fs
13 * journaling system.
14 *
15 * This file manages journals: areas of disk reserved for logging
16 * transactional updates. This includes the kernel journaling thread
17 * which is responsible for scheduling updates to the log.
18 *
19 * We do not actually manage the physical storage of the journal in this
20 * file: that is left to a per-journal policy function, which allows us
21 * to store the journal within a filesystem-specified area for ext2
22 * journaling (ext2 can use a reserved inode for storing the log).
23 */
24
25#include <linux/module.h>
26#include <linux/time.h>
27#include <linux/fs.h>
Mingming Caof7f4bcc2006-10-11 01:20:59 -070028#include <linux/jbd2.h>
Dave Kleikamp470decc2006-10-11 01:20:57 -070029#include <linux/errno.h>
30#include <linux/slab.h>
31#include <linux/smp_lock.h>
32#include <linux/init.h>
33#include <linux/mm.h>
34#include <linux/suspend.h>
35#include <linux/pagemap.h>
36#include <linux/kthread.h>
37#include <linux/poison.h>
38#include <linux/proc_fs.h>
39
40#include <asm/uaccess.h>
41#include <asm/page.h>
42
Mingming Caof7f4bcc2006-10-11 01:20:59 -070043EXPORT_SYMBOL(jbd2_journal_start);
44EXPORT_SYMBOL(jbd2_journal_restart);
45EXPORT_SYMBOL(jbd2_journal_extend);
46EXPORT_SYMBOL(jbd2_journal_stop);
47EXPORT_SYMBOL(jbd2_journal_lock_updates);
48EXPORT_SYMBOL(jbd2_journal_unlock_updates);
49EXPORT_SYMBOL(jbd2_journal_get_write_access);
50EXPORT_SYMBOL(jbd2_journal_get_create_access);
51EXPORT_SYMBOL(jbd2_journal_get_undo_access);
52EXPORT_SYMBOL(jbd2_journal_dirty_data);
53EXPORT_SYMBOL(jbd2_journal_dirty_metadata);
54EXPORT_SYMBOL(jbd2_journal_release_buffer);
55EXPORT_SYMBOL(jbd2_journal_forget);
Dave Kleikamp470decc2006-10-11 01:20:57 -070056#if 0
57EXPORT_SYMBOL(journal_sync_buffer);
58#endif
Mingming Caof7f4bcc2006-10-11 01:20:59 -070059EXPORT_SYMBOL(jbd2_journal_flush);
60EXPORT_SYMBOL(jbd2_journal_revoke);
Dave Kleikamp470decc2006-10-11 01:20:57 -070061
Mingming Caof7f4bcc2006-10-11 01:20:59 -070062EXPORT_SYMBOL(jbd2_journal_init_dev);
63EXPORT_SYMBOL(jbd2_journal_init_inode);
64EXPORT_SYMBOL(jbd2_journal_update_format);
65EXPORT_SYMBOL(jbd2_journal_check_used_features);
66EXPORT_SYMBOL(jbd2_journal_check_available_features);
67EXPORT_SYMBOL(jbd2_journal_set_features);
68EXPORT_SYMBOL(jbd2_journal_create);
69EXPORT_SYMBOL(jbd2_journal_load);
70EXPORT_SYMBOL(jbd2_journal_destroy);
71EXPORT_SYMBOL(jbd2_journal_update_superblock);
72EXPORT_SYMBOL(jbd2_journal_abort);
73EXPORT_SYMBOL(jbd2_journal_errno);
74EXPORT_SYMBOL(jbd2_journal_ack_err);
75EXPORT_SYMBOL(jbd2_journal_clear_err);
76EXPORT_SYMBOL(jbd2_log_wait_commit);
77EXPORT_SYMBOL(jbd2_journal_start_commit);
78EXPORT_SYMBOL(jbd2_journal_force_commit_nested);
79EXPORT_SYMBOL(jbd2_journal_wipe);
80EXPORT_SYMBOL(jbd2_journal_blocks_per_page);
81EXPORT_SYMBOL(jbd2_journal_invalidatepage);
82EXPORT_SYMBOL(jbd2_journal_try_to_free_buffers);
83EXPORT_SYMBOL(jbd2_journal_force_commit);
Dave Kleikamp470decc2006-10-11 01:20:57 -070084
85static int journal_convert_superblock_v1(journal_t *, journal_superblock_t *);
86static void __journal_abort_soft (journal_t *journal, int errno);
Mingming Caof7f4bcc2006-10-11 01:20:59 -070087static int jbd2_journal_create_jbd_slab(size_t slab_size);
Dave Kleikamp470decc2006-10-11 01:20:57 -070088
89/*
90 * Helper function used to manage commit timeouts
91 */
92
93static void commit_timeout(unsigned long __data)
94{
95 struct task_struct * p = (struct task_struct *) __data;
96
97 wake_up_process(p);
98}
99
100/*
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700101 * kjournald2: The main thread function used to manage a logging device
Dave Kleikamp470decc2006-10-11 01:20:57 -0700102 * journal.
103 *
104 * This kernel thread is responsible for two things:
105 *
106 * 1) COMMIT: Every so often we need to commit the current state of the
107 * filesystem to disk. The journal thread is responsible for writing
108 * all of the metadata buffers to disk.
109 *
110 * 2) CHECKPOINT: We cannot reuse a used section of the log file until all
111 * of the data in that part of the log has been rewritten elsewhere on
112 * the disk. Flushing these old buffers to reclaim space in the log is
113 * known as checkpointing, and this thread is responsible for that job.
114 */
115
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700116static int kjournald2(void *arg)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700117{
118 journal_t *journal = arg;
119 transaction_t *transaction;
120
121 /*
122 * Set up an interval timer which can be used to trigger a commit wakeup
123 * after the commit interval expires
124 */
125 setup_timer(&journal->j_commit_timer, commit_timeout,
126 (unsigned long)current);
127
128 /* Record that the journal thread is running */
129 journal->j_task = current;
130 wake_up(&journal->j_wait_done_commit);
131
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700132 printk(KERN_INFO "kjournald2 starting. Commit interval %ld seconds\n",
Dave Kleikamp470decc2006-10-11 01:20:57 -0700133 journal->j_commit_interval / HZ);
134
135 /*
136 * And now, wait forever for commit wakeup events.
137 */
138 spin_lock(&journal->j_state_lock);
139
140loop:
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700141 if (journal->j_flags & JBD2_UNMOUNT)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700142 goto end_loop;
143
144 jbd_debug(1, "commit_sequence=%d, commit_request=%d\n",
145 journal->j_commit_sequence, journal->j_commit_request);
146
147 if (journal->j_commit_sequence != journal->j_commit_request) {
148 jbd_debug(1, "OK, requests differ\n");
149 spin_unlock(&journal->j_state_lock);
150 del_timer_sync(&journal->j_commit_timer);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700151 jbd2_journal_commit_transaction(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700152 spin_lock(&journal->j_state_lock);
153 goto loop;
154 }
155
156 wake_up(&journal->j_wait_done_commit);
157 if (freezing(current)) {
158 /*
159 * The simpler the better. Flushing journal isn't a
160 * good idea, because that depends on threads that may
161 * be already stopped.
162 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700163 jbd_debug(1, "Now suspending kjournald2\n");
Dave Kleikamp470decc2006-10-11 01:20:57 -0700164 spin_unlock(&journal->j_state_lock);
165 refrigerator();
166 spin_lock(&journal->j_state_lock);
167 } else {
168 /*
169 * We assume on resume that commits are already there,
170 * so we don't sleep
171 */
172 DEFINE_WAIT(wait);
173 int should_sleep = 1;
174
175 prepare_to_wait(&journal->j_wait_commit, &wait,
176 TASK_INTERRUPTIBLE);
177 if (journal->j_commit_sequence != journal->j_commit_request)
178 should_sleep = 0;
179 transaction = journal->j_running_transaction;
180 if (transaction && time_after_eq(jiffies,
181 transaction->t_expires))
182 should_sleep = 0;
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700183 if (journal->j_flags & JBD2_UNMOUNT)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700184 should_sleep = 0;
185 if (should_sleep) {
186 spin_unlock(&journal->j_state_lock);
187 schedule();
188 spin_lock(&journal->j_state_lock);
189 }
190 finish_wait(&journal->j_wait_commit, &wait);
191 }
192
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700193 jbd_debug(1, "kjournald2 wakes\n");
Dave Kleikamp470decc2006-10-11 01:20:57 -0700194
195 /*
196 * Were we woken up by a commit wakeup event?
197 */
198 transaction = journal->j_running_transaction;
199 if (transaction && time_after_eq(jiffies, transaction->t_expires)) {
200 journal->j_commit_request = transaction->t_tid;
201 jbd_debug(1, "woke because of timeout\n");
202 }
203 goto loop;
204
205end_loop:
206 spin_unlock(&journal->j_state_lock);
207 del_timer_sync(&journal->j_commit_timer);
208 journal->j_task = NULL;
209 wake_up(&journal->j_wait_done_commit);
210 jbd_debug(1, "Journal thread exiting.\n");
211 return 0;
212}
213
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700214static void jbd2_journal_start_thread(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700215{
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700216 kthread_run(kjournald2, journal, "kjournald2");
Dave Kleikamp470decc2006-10-11 01:20:57 -0700217 wait_event(journal->j_wait_done_commit, journal->j_task != 0);
218}
219
220static void journal_kill_thread(journal_t *journal)
221{
222 spin_lock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700223 journal->j_flags |= JBD2_UNMOUNT;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700224
225 while (journal->j_task) {
226 wake_up(&journal->j_wait_commit);
227 spin_unlock(&journal->j_state_lock);
228 wait_event(journal->j_wait_done_commit, journal->j_task == 0);
229 spin_lock(&journal->j_state_lock);
230 }
231 spin_unlock(&journal->j_state_lock);
232}
233
234/*
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700235 * jbd2_journal_write_metadata_buffer: write a metadata buffer to the journal.
Dave Kleikamp470decc2006-10-11 01:20:57 -0700236 *
237 * Writes a metadata buffer to a given disk block. The actual IO is not
238 * performed but a new buffer_head is constructed which labels the data
239 * to be written with the correct destination disk block.
240 *
241 * Any magic-number escaping which needs to be done will cause a
242 * copy-out here. If the buffer happens to start with the
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700243 * JBD2_MAGIC_NUMBER, then we can't write it to the log directly: the
Dave Kleikamp470decc2006-10-11 01:20:57 -0700244 * magic number is only written to the log for descripter blocks. In
245 * this case, we copy the data and replace the first word with 0, and we
246 * return a result code which indicates that this buffer needs to be
247 * marked as an escaped buffer in the corresponding log descriptor
248 * block. The missing word can then be restored when the block is read
249 * during recovery.
250 *
251 * If the source buffer has already been modified by a new transaction
252 * since we took the last commit snapshot, we use the frozen copy of
253 * that data for IO. If we end up using the existing buffer_head's data
254 * for the write, then we *have* to lock the buffer to prevent anyone
255 * else from using and possibly modifying it while the IO is in
256 * progress.
257 *
258 * The function returns a pointer to the buffer_heads to be used for IO.
259 *
260 * We assume that the journal has already been locked in this function.
261 *
262 * Return value:
263 * <0: Error
264 * >=0: Finished OK
265 *
266 * On success:
267 * Bit 0 set == escape performed on the data
268 * Bit 1 set == buffer copy-out performed (kfree the data after IO)
269 */
270
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700271int jbd2_journal_write_metadata_buffer(transaction_t *transaction,
Dave Kleikamp470decc2006-10-11 01:20:57 -0700272 struct journal_head *jh_in,
273 struct journal_head **jh_out,
274 unsigned long blocknr)
275{
276 int need_copy_out = 0;
277 int done_copy_out = 0;
278 int do_escape = 0;
279 char *mapped_data;
280 struct buffer_head *new_bh;
281 struct journal_head *new_jh;
282 struct page *new_page;
283 unsigned int new_offset;
284 struct buffer_head *bh_in = jh2bh(jh_in);
285
286 /*
287 * The buffer really shouldn't be locked: only the current committing
288 * transaction is allowed to write it, so nobody else is allowed
289 * to do any IO.
290 *
291 * akpm: except if we're journalling data, and write() output is
292 * also part of a shared mapping, and another thread has
293 * decided to launch a writepage() against this buffer.
294 */
295 J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in));
296
297 new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL);
298
299 /*
300 * If a new transaction has already done a buffer copy-out, then
301 * we use that version of the data for the commit.
302 */
303 jbd_lock_bh_state(bh_in);
304repeat:
305 if (jh_in->b_frozen_data) {
306 done_copy_out = 1;
307 new_page = virt_to_page(jh_in->b_frozen_data);
308 new_offset = offset_in_page(jh_in->b_frozen_data);
309 } else {
310 new_page = jh2bh(jh_in)->b_page;
311 new_offset = offset_in_page(jh2bh(jh_in)->b_data);
312 }
313
314 mapped_data = kmap_atomic(new_page, KM_USER0);
315 /*
316 * Check for escaping
317 */
318 if (*((__be32 *)(mapped_data + new_offset)) ==
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700319 cpu_to_be32(JBD2_MAGIC_NUMBER)) {
Dave Kleikamp470decc2006-10-11 01:20:57 -0700320 need_copy_out = 1;
321 do_escape = 1;
322 }
323 kunmap_atomic(mapped_data, KM_USER0);
324
325 /*
326 * Do we need to do a data copy?
327 */
328 if (need_copy_out && !done_copy_out) {
329 char *tmp;
330
331 jbd_unlock_bh_state(bh_in);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700332 tmp = jbd2_slab_alloc(bh_in->b_size, GFP_NOFS);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700333 jbd_lock_bh_state(bh_in);
334 if (jh_in->b_frozen_data) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700335 jbd2_slab_free(tmp, bh_in->b_size);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700336 goto repeat;
337 }
338
339 jh_in->b_frozen_data = tmp;
340 mapped_data = kmap_atomic(new_page, KM_USER0);
341 memcpy(tmp, mapped_data + new_offset, jh2bh(jh_in)->b_size);
342 kunmap_atomic(mapped_data, KM_USER0);
343
344 new_page = virt_to_page(tmp);
345 new_offset = offset_in_page(tmp);
346 done_copy_out = 1;
347 }
348
349 /*
350 * Did we need to do an escaping? Now we've done all the
351 * copying, we can finally do so.
352 */
353 if (do_escape) {
354 mapped_data = kmap_atomic(new_page, KM_USER0);
355 *((unsigned int *)(mapped_data + new_offset)) = 0;
356 kunmap_atomic(mapped_data, KM_USER0);
357 }
358
359 /* keep subsequent assertions sane */
360 new_bh->b_state = 0;
361 init_buffer(new_bh, NULL, NULL);
362 atomic_set(&new_bh->b_count, 1);
363 jbd_unlock_bh_state(bh_in);
364
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700365 new_jh = jbd2_journal_add_journal_head(new_bh); /* This sleeps */
Dave Kleikamp470decc2006-10-11 01:20:57 -0700366
367 set_bh_page(new_bh, new_page, new_offset);
368 new_jh->b_transaction = NULL;
369 new_bh->b_size = jh2bh(jh_in)->b_size;
370 new_bh->b_bdev = transaction->t_journal->j_dev;
371 new_bh->b_blocknr = blocknr;
372 set_buffer_mapped(new_bh);
373 set_buffer_dirty(new_bh);
374
375 *jh_out = new_jh;
376
377 /*
378 * The to-be-written buffer needs to get moved to the io queue,
379 * and the original buffer whose contents we are shadowing or
380 * copying is moved to the transaction's shadow queue.
381 */
382 JBUFFER_TRACE(jh_in, "file as BJ_Shadow");
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700383 jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700384 JBUFFER_TRACE(new_jh, "file as BJ_IO");
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700385 jbd2_journal_file_buffer(new_jh, transaction, BJ_IO);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700386
387 return do_escape | (done_copy_out << 1);
388}
389
390/*
391 * Allocation code for the journal file. Manage the space left in the
392 * journal, so that we can begin checkpointing when appropriate.
393 */
394
395/*
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700396 * __jbd2_log_space_left: Return the number of free blocks left in the journal.
Dave Kleikamp470decc2006-10-11 01:20:57 -0700397 *
398 * Called with the journal already locked.
399 *
400 * Called under j_state_lock
401 */
402
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700403int __jbd2_log_space_left(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700404{
405 int left = journal->j_free;
406
407 assert_spin_locked(&journal->j_state_lock);
408
409 /*
410 * Be pessimistic here about the number of those free blocks which
411 * might be required for log descriptor control blocks.
412 */
413
414#define MIN_LOG_RESERVED_BLOCKS 32 /* Allow for rounding errors */
415
416 left -= MIN_LOG_RESERVED_BLOCKS;
417
418 if (left <= 0)
419 return 0;
420 left -= (left >> 3);
421 return left;
422}
423
424/*
425 * Called under j_state_lock. Returns true if a transaction was started.
426 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700427int __jbd2_log_start_commit(journal_t *journal, tid_t target)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700428{
429 /*
430 * Are we already doing a recent enough commit?
431 */
432 if (!tid_geq(journal->j_commit_request, target)) {
433 /*
434 * We want a new commit: OK, mark the request and wakup the
435 * commit thread. We do _not_ do the commit ourselves.
436 */
437
438 journal->j_commit_request = target;
439 jbd_debug(1, "JBD: requesting commit %d/%d\n",
440 journal->j_commit_request,
441 journal->j_commit_sequence);
442 wake_up(&journal->j_wait_commit);
443 return 1;
444 }
445 return 0;
446}
447
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700448int jbd2_log_start_commit(journal_t *journal, tid_t tid)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700449{
450 int ret;
451
452 spin_lock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700453 ret = __jbd2_log_start_commit(journal, tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700454 spin_unlock(&journal->j_state_lock);
455 return ret;
456}
457
458/*
459 * Force and wait upon a commit if the calling process is not within
460 * transaction. This is used for forcing out undo-protected data which contains
461 * bitmaps, when the fs is running out of space.
462 *
463 * We can only force the running transaction if we don't have an active handle;
464 * otherwise, we will deadlock.
465 *
466 * Returns true if a transaction was started.
467 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700468int jbd2_journal_force_commit_nested(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700469{
470 transaction_t *transaction = NULL;
471 tid_t tid;
472
473 spin_lock(&journal->j_state_lock);
474 if (journal->j_running_transaction && !current->journal_info) {
475 transaction = journal->j_running_transaction;
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700476 __jbd2_log_start_commit(journal, transaction->t_tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700477 } else if (journal->j_committing_transaction)
478 transaction = journal->j_committing_transaction;
479
480 if (!transaction) {
481 spin_unlock(&journal->j_state_lock);
482 return 0; /* Nothing to retry */
483 }
484
485 tid = transaction->t_tid;
486 spin_unlock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700487 jbd2_log_wait_commit(journal, tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700488 return 1;
489}
490
491/*
492 * Start a commit of the current running transaction (if any). Returns true
493 * if a transaction was started, and fills its tid in at *ptid
494 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700495int jbd2_journal_start_commit(journal_t *journal, tid_t *ptid)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700496{
497 int ret = 0;
498
499 spin_lock(&journal->j_state_lock);
500 if (journal->j_running_transaction) {
501 tid_t tid = journal->j_running_transaction->t_tid;
502
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700503 ret = __jbd2_log_start_commit(journal, tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700504 if (ret && ptid)
505 *ptid = tid;
506 } else if (journal->j_committing_transaction && ptid) {
507 /*
508 * If ext3_write_super() recently started a commit, then we
509 * have to wait for completion of that transaction
510 */
511 *ptid = journal->j_committing_transaction->t_tid;
512 ret = 1;
513 }
514 spin_unlock(&journal->j_state_lock);
515 return ret;
516}
517
518/*
519 * Wait for a specified commit to complete.
520 * The caller may not hold the journal lock.
521 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700522int jbd2_log_wait_commit(journal_t *journal, tid_t tid)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700523{
524 int err = 0;
525
526#ifdef CONFIG_JBD_DEBUG
527 spin_lock(&journal->j_state_lock);
528 if (!tid_geq(journal->j_commit_request, tid)) {
529 printk(KERN_EMERG
530 "%s: error: j_commit_request=%d, tid=%d\n",
531 __FUNCTION__, journal->j_commit_request, tid);
532 }
533 spin_unlock(&journal->j_state_lock);
534#endif
535 spin_lock(&journal->j_state_lock);
536 while (tid_gt(tid, journal->j_commit_sequence)) {
537 jbd_debug(1, "JBD: want %d, j_commit_sequence=%d\n",
538 tid, journal->j_commit_sequence);
539 wake_up(&journal->j_wait_commit);
540 spin_unlock(&journal->j_state_lock);
541 wait_event(journal->j_wait_done_commit,
542 !tid_gt(tid, journal->j_commit_sequence));
543 spin_lock(&journal->j_state_lock);
544 }
545 spin_unlock(&journal->j_state_lock);
546
547 if (unlikely(is_journal_aborted(journal))) {
548 printk(KERN_EMERG "journal commit I/O error\n");
549 err = -EIO;
550 }
551 return err;
552}
553
554/*
555 * Log buffer allocation routines:
556 */
557
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700558int jbd2_journal_next_log_block(journal_t *journal, unsigned long *retp)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700559{
560 unsigned long blocknr;
561
562 spin_lock(&journal->j_state_lock);
563 J_ASSERT(journal->j_free > 1);
564
565 blocknr = journal->j_head;
566 journal->j_head++;
567 journal->j_free--;
568 if (journal->j_head == journal->j_last)
569 journal->j_head = journal->j_first;
570 spin_unlock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700571 return jbd2_journal_bmap(journal, blocknr, retp);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700572}
573
574/*
575 * Conversion of logical to physical block numbers for the journal
576 *
577 * On external journals the journal blocks are identity-mapped, so
578 * this is a no-op. If needed, we can use j_blk_offset - everything is
579 * ready.
580 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700581int jbd2_journal_bmap(journal_t *journal, unsigned long blocknr,
Dave Kleikamp470decc2006-10-11 01:20:57 -0700582 unsigned long *retp)
583{
584 int err = 0;
585 unsigned long ret;
586
587 if (journal->j_inode) {
588 ret = bmap(journal->j_inode, blocknr);
589 if (ret)
590 *retp = ret;
591 else {
592 char b[BDEVNAME_SIZE];
593
594 printk(KERN_ALERT "%s: journal block not found "
595 "at offset %lu on %s\n",
596 __FUNCTION__,
597 blocknr,
598 bdevname(journal->j_dev, b));
599 err = -EIO;
600 __journal_abort_soft(journal, err);
601 }
602 } else {
603 *retp = blocknr; /* +journal->j_blk_offset */
604 }
605 return err;
606}
607
608/*
609 * We play buffer_head aliasing tricks to write data/metadata blocks to
610 * the journal without copying their contents, but for journal
611 * descriptor blocks we do need to generate bona fide buffers.
612 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700613 * After the caller of jbd2_journal_get_descriptor_buffer() has finished modifying
Dave Kleikamp470decc2006-10-11 01:20:57 -0700614 * the buffer's contents they really should run flush_dcache_page(bh->b_page).
615 * But we don't bother doing that, so there will be coherency problems with
616 * mmaps of blockdevs which hold live JBD-controlled filesystems.
617 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700618struct journal_head *jbd2_journal_get_descriptor_buffer(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700619{
620 struct buffer_head *bh;
621 unsigned long blocknr;
622 int err;
623
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700624 err = jbd2_journal_next_log_block(journal, &blocknr);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700625
626 if (err)
627 return NULL;
628
629 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
630 lock_buffer(bh);
631 memset(bh->b_data, 0, journal->j_blocksize);
632 set_buffer_uptodate(bh);
633 unlock_buffer(bh);
634 BUFFER_TRACE(bh, "return this buffer");
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700635 return jbd2_journal_add_journal_head(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700636}
637
638/*
639 * Management for journal control blocks: functions to create and
640 * destroy journal_t structures, and to initialise and read existing
641 * journal blocks from disk. */
642
643/* First: create and setup a journal_t object in memory. We initialise
644 * very few fields yet: that has to wait until we have created the
645 * journal structures from from scratch, or loaded them from disk. */
646
647static journal_t * journal_init_common (void)
648{
649 journal_t *journal;
650 int err;
651
652 journal = jbd_kmalloc(sizeof(*journal), GFP_KERNEL);
653 if (!journal)
654 goto fail;
655 memset(journal, 0, sizeof(*journal));
656
657 init_waitqueue_head(&journal->j_wait_transaction_locked);
658 init_waitqueue_head(&journal->j_wait_logspace);
659 init_waitqueue_head(&journal->j_wait_done_commit);
660 init_waitqueue_head(&journal->j_wait_checkpoint);
661 init_waitqueue_head(&journal->j_wait_commit);
662 init_waitqueue_head(&journal->j_wait_updates);
663 mutex_init(&journal->j_barrier);
664 mutex_init(&journal->j_checkpoint_mutex);
665 spin_lock_init(&journal->j_revoke_lock);
666 spin_lock_init(&journal->j_list_lock);
667 spin_lock_init(&journal->j_state_lock);
668
669 journal->j_commit_interval = (HZ * JBD_DEFAULT_MAX_COMMIT_AGE);
670
671 /* The journal is marked for error until we succeed with recovery! */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700672 journal->j_flags = JBD2_ABORT;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700673
674 /* Set up a default-sized revoke table for the new mount. */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700675 err = jbd2_journal_init_revoke(journal, JOURNAL_REVOKE_DEFAULT_HASH);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700676 if (err) {
677 kfree(journal);
678 goto fail;
679 }
680 return journal;
681fail:
682 return NULL;
683}
684
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700685/* jbd2_journal_init_dev and jbd2_journal_init_inode:
Dave Kleikamp470decc2006-10-11 01:20:57 -0700686 *
687 * Create a journal structure assigned some fixed set of disk blocks to
688 * the journal. We don't actually touch those disk blocks yet, but we
689 * need to set up all of the mapping information to tell the journaling
690 * system where the journal blocks are.
691 *
692 */
693
694/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700695 * journal_t * jbd2_journal_init_dev() - creates an initialises a journal structure
Dave Kleikamp470decc2006-10-11 01:20:57 -0700696 * @bdev: Block device on which to create the journal
697 * @fs_dev: Device which hold journalled filesystem for this journal.
698 * @start: Block nr Start of journal.
699 * @len: Length of the journal in blocks.
700 * @blocksize: blocksize of journalling device
701 * @returns: a newly created journal_t *
702 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700703 * jbd2_journal_init_dev creates a journal which maps a fixed contiguous
Dave Kleikamp470decc2006-10-11 01:20:57 -0700704 * range of blocks on an arbitrary block device.
705 *
706 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700707journal_t * jbd2_journal_init_dev(struct block_device *bdev,
Dave Kleikamp470decc2006-10-11 01:20:57 -0700708 struct block_device *fs_dev,
709 int start, int len, int blocksize)
710{
711 journal_t *journal = journal_init_common();
712 struct buffer_head *bh;
713 int n;
714
715 if (!journal)
716 return NULL;
717
718 /* journal descriptor can store up to n blocks -bzzz */
719 journal->j_blocksize = blocksize;
720 n = journal->j_blocksize / sizeof(journal_block_tag_t);
721 journal->j_wbufsize = n;
722 journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
723 if (!journal->j_wbuf) {
724 printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n",
725 __FUNCTION__);
726 kfree(journal);
727 journal = NULL;
728 }
729 journal->j_dev = bdev;
730 journal->j_fs_dev = fs_dev;
731 journal->j_blk_offset = start;
732 journal->j_maxlen = len;
733
734 bh = __getblk(journal->j_dev, start, journal->j_blocksize);
735 J_ASSERT(bh != NULL);
736 journal->j_sb_buffer = bh;
737 journal->j_superblock = (journal_superblock_t *)bh->b_data;
738
739 return journal;
740}
741
742/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700743 * journal_t * jbd2_journal_init_inode () - creates a journal which maps to a inode.
Dave Kleikamp470decc2006-10-11 01:20:57 -0700744 * @inode: An inode to create the journal in
745 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700746 * jbd2_journal_init_inode creates a journal which maps an on-disk inode as
Dave Kleikamp470decc2006-10-11 01:20:57 -0700747 * the journal. The inode must exist already, must support bmap() and
748 * must have all data blocks preallocated.
749 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700750journal_t * jbd2_journal_init_inode (struct inode *inode)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700751{
752 struct buffer_head *bh;
753 journal_t *journal = journal_init_common();
754 int err;
755 int n;
756 unsigned long blocknr;
757
758 if (!journal)
759 return NULL;
760
761 journal->j_dev = journal->j_fs_dev = inode->i_sb->s_bdev;
762 journal->j_inode = inode;
763 jbd_debug(1,
764 "journal %p: inode %s/%ld, size %Ld, bits %d, blksize %ld\n",
765 journal, inode->i_sb->s_id, inode->i_ino,
766 (long long) inode->i_size,
767 inode->i_sb->s_blocksize_bits, inode->i_sb->s_blocksize);
768
769 journal->j_maxlen = inode->i_size >> inode->i_sb->s_blocksize_bits;
770 journal->j_blocksize = inode->i_sb->s_blocksize;
771
772 /* journal descriptor can store up to n blocks -bzzz */
773 n = journal->j_blocksize / sizeof(journal_block_tag_t);
774 journal->j_wbufsize = n;
775 journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
776 if (!journal->j_wbuf) {
777 printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n",
778 __FUNCTION__);
779 kfree(journal);
780 return NULL;
781 }
782
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700783 err = jbd2_journal_bmap(journal, 0, &blocknr);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700784 /* If that failed, give up */
785 if (err) {
786 printk(KERN_ERR "%s: Cannnot locate journal superblock\n",
787 __FUNCTION__);
788 kfree(journal);
789 return NULL;
790 }
791
792 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
793 J_ASSERT(bh != NULL);
794 journal->j_sb_buffer = bh;
795 journal->j_superblock = (journal_superblock_t *)bh->b_data;
796
797 return journal;
798}
799
800/*
801 * If the journal init or create aborts, we need to mark the journal
802 * superblock as being NULL to prevent the journal destroy from writing
803 * back a bogus superblock.
804 */
805static void journal_fail_superblock (journal_t *journal)
806{
807 struct buffer_head *bh = journal->j_sb_buffer;
808 brelse(bh);
809 journal->j_sb_buffer = NULL;
810}
811
812/*
813 * Given a journal_t structure, initialise the various fields for
814 * startup of a new journaling session. We use this both when creating
815 * a journal, and after recovering an old journal to reset it for
816 * subsequent use.
817 */
818
819static int journal_reset(journal_t *journal)
820{
821 journal_superblock_t *sb = journal->j_superblock;
822 unsigned long first, last;
823
824 first = be32_to_cpu(sb->s_first);
825 last = be32_to_cpu(sb->s_maxlen);
826
827 journal->j_first = first;
828 journal->j_last = last;
829
830 journal->j_head = first;
831 journal->j_tail = first;
832 journal->j_free = last - first;
833
834 journal->j_tail_sequence = journal->j_transaction_sequence;
835 journal->j_commit_sequence = journal->j_transaction_sequence - 1;
836 journal->j_commit_request = journal->j_commit_sequence;
837
838 journal->j_max_transaction_buffers = journal->j_maxlen / 4;
839
840 /* Add the dynamic fields and write it to disk. */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700841 jbd2_journal_update_superblock(journal, 1);
842 jbd2_journal_start_thread(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700843 return 0;
844}
845
846/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700847 * int jbd2_journal_create() - Initialise the new journal file
Dave Kleikamp470decc2006-10-11 01:20:57 -0700848 * @journal: Journal to create. This structure must have been initialised
849 *
850 * Given a journal_t structure which tells us which disk blocks we can
851 * use, create a new journal superblock and initialise all of the
852 * journal fields from scratch.
853 **/
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700854int jbd2_journal_create(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700855{
856 unsigned long blocknr;
857 struct buffer_head *bh;
858 journal_superblock_t *sb;
859 int i, err;
860
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700861 if (journal->j_maxlen < JBD2_MIN_JOURNAL_BLOCKS) {
Dave Kleikamp470decc2006-10-11 01:20:57 -0700862 printk (KERN_ERR "Journal length (%d blocks) too short.\n",
863 journal->j_maxlen);
864 journal_fail_superblock(journal);
865 return -EINVAL;
866 }
867
868 if (journal->j_inode == NULL) {
869 /*
870 * We don't know what block to start at!
871 */
872 printk(KERN_EMERG
873 "%s: creation of journal on external device!\n",
874 __FUNCTION__);
875 BUG();
876 }
877
878 /* Zero out the entire journal on disk. We cannot afford to
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700879 have any blocks on disk beginning with JBD2_MAGIC_NUMBER. */
Dave Kleikamp470decc2006-10-11 01:20:57 -0700880 jbd_debug(1, "JBD: Zeroing out journal blocks...\n");
881 for (i = 0; i < journal->j_maxlen; i++) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700882 err = jbd2_journal_bmap(journal, i, &blocknr);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700883 if (err)
884 return err;
885 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
886 lock_buffer(bh);
887 memset (bh->b_data, 0, journal->j_blocksize);
888 BUFFER_TRACE(bh, "marking dirty");
889 mark_buffer_dirty(bh);
890 BUFFER_TRACE(bh, "marking uptodate");
891 set_buffer_uptodate(bh);
892 unlock_buffer(bh);
893 __brelse(bh);
894 }
895
896 sync_blockdev(journal->j_dev);
897 jbd_debug(1, "JBD: journal cleared.\n");
898
899 /* OK, fill in the initial static fields in the new superblock */
900 sb = journal->j_superblock;
901
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700902 sb->s_header.h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER);
903 sb->s_header.h_blocktype = cpu_to_be32(JBD2_SUPERBLOCK_V2);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700904
905 sb->s_blocksize = cpu_to_be32(journal->j_blocksize);
906 sb->s_maxlen = cpu_to_be32(journal->j_maxlen);
907 sb->s_first = cpu_to_be32(1);
908
909 journal->j_transaction_sequence = 1;
910
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700911 journal->j_flags &= ~JBD2_ABORT;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700912 journal->j_format_version = 2;
913
914 return journal_reset(journal);
915}
916
917/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700918 * void jbd2_journal_update_superblock() - Update journal sb on disk.
Dave Kleikamp470decc2006-10-11 01:20:57 -0700919 * @journal: The journal to update.
920 * @wait: Set to '0' if you don't want to wait for IO completion.
921 *
922 * Update a journal's dynamic superblock fields and write it to disk,
923 * optionally waiting for the IO to complete.
924 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700925void jbd2_journal_update_superblock(journal_t *journal, int wait)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700926{
927 journal_superblock_t *sb = journal->j_superblock;
928 struct buffer_head *bh = journal->j_sb_buffer;
929
930 /*
931 * As a special case, if the on-disk copy is already marked as needing
932 * no recovery (s_start == 0) and there are no outstanding transactions
933 * in the filesystem, then we can safely defer the superblock update
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700934 * until the next commit by setting JBD2_FLUSHED. This avoids
Dave Kleikamp470decc2006-10-11 01:20:57 -0700935 * attempting a write to a potential-readonly device.
936 */
937 if (sb->s_start == 0 && journal->j_tail_sequence ==
938 journal->j_transaction_sequence) {
939 jbd_debug(1,"JBD: Skipping superblock update on recovered sb "
940 "(start %ld, seq %d, errno %d)\n",
941 journal->j_tail, journal->j_tail_sequence,
942 journal->j_errno);
943 goto out;
944 }
945
946 spin_lock(&journal->j_state_lock);
947 jbd_debug(1,"JBD: updating superblock (start %ld, seq %d, errno %d)\n",
948 journal->j_tail, journal->j_tail_sequence, journal->j_errno);
949
950 sb->s_sequence = cpu_to_be32(journal->j_tail_sequence);
951 sb->s_start = cpu_to_be32(journal->j_tail);
952 sb->s_errno = cpu_to_be32(journal->j_errno);
953 spin_unlock(&journal->j_state_lock);
954
955 BUFFER_TRACE(bh, "marking dirty");
956 mark_buffer_dirty(bh);
957 if (wait)
958 sync_dirty_buffer(bh);
959 else
960 ll_rw_block(SWRITE, 1, &bh);
961
962out:
963 /* If we have just flushed the log (by marking s_start==0), then
964 * any future commit will have to be careful to update the
965 * superblock again to re-record the true start of the log. */
966
967 spin_lock(&journal->j_state_lock);
968 if (sb->s_start)
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700969 journal->j_flags &= ~JBD2_FLUSHED;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700970 else
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700971 journal->j_flags |= JBD2_FLUSHED;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700972 spin_unlock(&journal->j_state_lock);
973}
974
975/*
976 * Read the superblock for a given journal, performing initial
977 * validation of the format.
978 */
979
980static int journal_get_superblock(journal_t *journal)
981{
982 struct buffer_head *bh;
983 journal_superblock_t *sb;
984 int err = -EIO;
985
986 bh = journal->j_sb_buffer;
987
988 J_ASSERT(bh != NULL);
989 if (!buffer_uptodate(bh)) {
990 ll_rw_block(READ, 1, &bh);
991 wait_on_buffer(bh);
992 if (!buffer_uptodate(bh)) {
993 printk (KERN_ERR
994 "JBD: IO error reading journal superblock\n");
995 goto out;
996 }
997 }
998
999 sb = journal->j_superblock;
1000
1001 err = -EINVAL;
1002
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001003 if (sb->s_header.h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER) ||
Dave Kleikamp470decc2006-10-11 01:20:57 -07001004 sb->s_blocksize != cpu_to_be32(journal->j_blocksize)) {
1005 printk(KERN_WARNING "JBD: no valid journal superblock found\n");
1006 goto out;
1007 }
1008
1009 switch(be32_to_cpu(sb->s_header.h_blocktype)) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001010 case JBD2_SUPERBLOCK_V1:
Dave Kleikamp470decc2006-10-11 01:20:57 -07001011 journal->j_format_version = 1;
1012 break;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001013 case JBD2_SUPERBLOCK_V2:
Dave Kleikamp470decc2006-10-11 01:20:57 -07001014 journal->j_format_version = 2;
1015 break;
1016 default:
1017 printk(KERN_WARNING "JBD: unrecognised superblock format ID\n");
1018 goto out;
1019 }
1020
1021 if (be32_to_cpu(sb->s_maxlen) < journal->j_maxlen)
1022 journal->j_maxlen = be32_to_cpu(sb->s_maxlen);
1023 else if (be32_to_cpu(sb->s_maxlen) > journal->j_maxlen) {
1024 printk (KERN_WARNING "JBD: journal file too short\n");
1025 goto out;
1026 }
1027
1028 return 0;
1029
1030out:
1031 journal_fail_superblock(journal);
1032 return err;
1033}
1034
1035/*
1036 * Load the on-disk journal superblock and read the key fields into the
1037 * journal_t.
1038 */
1039
1040static int load_superblock(journal_t *journal)
1041{
1042 int err;
1043 journal_superblock_t *sb;
1044
1045 err = journal_get_superblock(journal);
1046 if (err)
1047 return err;
1048
1049 sb = journal->j_superblock;
1050
1051 journal->j_tail_sequence = be32_to_cpu(sb->s_sequence);
1052 journal->j_tail = be32_to_cpu(sb->s_start);
1053 journal->j_first = be32_to_cpu(sb->s_first);
1054 journal->j_last = be32_to_cpu(sb->s_maxlen);
1055 journal->j_errno = be32_to_cpu(sb->s_errno);
1056
1057 return 0;
1058}
1059
1060
1061/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001062 * int jbd2_journal_load() - Read journal from disk.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001063 * @journal: Journal to act on.
1064 *
1065 * Given a journal_t structure which tells us which disk blocks contain
1066 * a journal, read the journal from disk to initialise the in-memory
1067 * structures.
1068 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001069int jbd2_journal_load(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001070{
1071 int err;
1072 journal_superblock_t *sb;
1073
1074 err = load_superblock(journal);
1075 if (err)
1076 return err;
1077
1078 sb = journal->j_superblock;
1079 /* If this is a V2 superblock, then we have to check the
1080 * features flags on it. */
1081
1082 if (journal->j_format_version >= 2) {
1083 if ((sb->s_feature_ro_compat &
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001084 ~cpu_to_be32(JBD2_KNOWN_ROCOMPAT_FEATURES)) ||
Dave Kleikamp470decc2006-10-11 01:20:57 -07001085 (sb->s_feature_incompat &
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001086 ~cpu_to_be32(JBD2_KNOWN_INCOMPAT_FEATURES))) {
Dave Kleikamp470decc2006-10-11 01:20:57 -07001087 printk (KERN_WARNING
1088 "JBD: Unrecognised features on journal\n");
1089 return -EINVAL;
1090 }
1091 }
1092
1093 /*
1094 * Create a slab for this blocksize
1095 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001096 err = jbd2_journal_create_jbd_slab(be32_to_cpu(sb->s_blocksize));
Dave Kleikamp470decc2006-10-11 01:20:57 -07001097 if (err)
1098 return err;
1099
1100 /* Let the recovery code check whether it needs to recover any
1101 * data from the journal. */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001102 if (jbd2_journal_recover(journal))
Dave Kleikamp470decc2006-10-11 01:20:57 -07001103 goto recovery_error;
1104
1105 /* OK, we've finished with the dynamic journal bits:
1106 * reinitialise the dynamic contents of the superblock in memory
1107 * and reset them on disk. */
1108 if (journal_reset(journal))
1109 goto recovery_error;
1110
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001111 journal->j_flags &= ~JBD2_ABORT;
1112 journal->j_flags |= JBD2_LOADED;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001113 return 0;
1114
1115recovery_error:
1116 printk (KERN_WARNING "JBD: recovery failed\n");
1117 return -EIO;
1118}
1119
1120/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001121 * void jbd2_journal_destroy() - Release a journal_t structure.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001122 * @journal: Journal to act on.
1123 *
1124 * Release a journal_t structure once it is no longer in use by the
1125 * journaled object.
1126 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001127void jbd2_journal_destroy(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001128{
1129 /* Wait for the commit thread to wake up and die. */
1130 journal_kill_thread(journal);
1131
1132 /* Force a final log commit */
1133 if (journal->j_running_transaction)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001134 jbd2_journal_commit_transaction(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001135
1136 /* Force any old transactions to disk */
1137
1138 /* Totally anal locking here... */
1139 spin_lock(&journal->j_list_lock);
1140 while (journal->j_checkpoint_transactions != NULL) {
1141 spin_unlock(&journal->j_list_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001142 jbd2_log_do_checkpoint(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001143 spin_lock(&journal->j_list_lock);
1144 }
1145
1146 J_ASSERT(journal->j_running_transaction == NULL);
1147 J_ASSERT(journal->j_committing_transaction == NULL);
1148 J_ASSERT(journal->j_checkpoint_transactions == NULL);
1149 spin_unlock(&journal->j_list_lock);
1150
1151 /* We can now mark the journal as empty. */
1152 journal->j_tail = 0;
1153 journal->j_tail_sequence = ++journal->j_transaction_sequence;
1154 if (journal->j_sb_buffer) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001155 jbd2_journal_update_superblock(journal, 1);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001156 brelse(journal->j_sb_buffer);
1157 }
1158
1159 if (journal->j_inode)
1160 iput(journal->j_inode);
1161 if (journal->j_revoke)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001162 jbd2_journal_destroy_revoke(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001163 kfree(journal->j_wbuf);
1164 kfree(journal);
1165}
1166
1167
1168/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001169 *int jbd2_journal_check_used_features () - Check if features specified are used.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001170 * @journal: Journal to check.
1171 * @compat: bitmask of compatible features
1172 * @ro: bitmask of features that force read-only mount
1173 * @incompat: bitmask of incompatible features
1174 *
1175 * Check whether the journal uses all of a given set of
1176 * features. Return true (non-zero) if it does.
1177 **/
1178
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001179int jbd2_journal_check_used_features (journal_t *journal, unsigned long compat,
Dave Kleikamp470decc2006-10-11 01:20:57 -07001180 unsigned long ro, unsigned long incompat)
1181{
1182 journal_superblock_t *sb;
1183
1184 if (!compat && !ro && !incompat)
1185 return 1;
1186 if (journal->j_format_version == 1)
1187 return 0;
1188
1189 sb = journal->j_superblock;
1190
1191 if (((be32_to_cpu(sb->s_feature_compat) & compat) == compat) &&
1192 ((be32_to_cpu(sb->s_feature_ro_compat) & ro) == ro) &&
1193 ((be32_to_cpu(sb->s_feature_incompat) & incompat) == incompat))
1194 return 1;
1195
1196 return 0;
1197}
1198
1199/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001200 * int jbd2_journal_check_available_features() - Check feature set in journalling layer
Dave Kleikamp470decc2006-10-11 01:20:57 -07001201 * @journal: Journal to check.
1202 * @compat: bitmask of compatible features
1203 * @ro: bitmask of features that force read-only mount
1204 * @incompat: bitmask of incompatible features
1205 *
1206 * Check whether the journaling code supports the use of
1207 * all of a given set of features on this journal. Return true
1208 * (non-zero) if it can. */
1209
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001210int jbd2_journal_check_available_features (journal_t *journal, unsigned long compat,
Dave Kleikamp470decc2006-10-11 01:20:57 -07001211 unsigned long ro, unsigned long incompat)
1212{
1213 journal_superblock_t *sb;
1214
1215 if (!compat && !ro && !incompat)
1216 return 1;
1217
1218 sb = journal->j_superblock;
1219
1220 /* We can support any known requested features iff the
1221 * superblock is in version 2. Otherwise we fail to support any
1222 * extended sb features. */
1223
1224 if (journal->j_format_version != 2)
1225 return 0;
1226
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001227 if ((compat & JBD2_KNOWN_COMPAT_FEATURES) == compat &&
1228 (ro & JBD2_KNOWN_ROCOMPAT_FEATURES) == ro &&
1229 (incompat & JBD2_KNOWN_INCOMPAT_FEATURES) == incompat)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001230 return 1;
1231
1232 return 0;
1233}
1234
1235/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001236 * int jbd2_journal_set_features () - Mark a given journal feature in the superblock
Dave Kleikamp470decc2006-10-11 01:20:57 -07001237 * @journal: Journal to act on.
1238 * @compat: bitmask of compatible features
1239 * @ro: bitmask of features that force read-only mount
1240 * @incompat: bitmask of incompatible features
1241 *
1242 * Mark a given journal feature as present on the
1243 * superblock. Returns true if the requested features could be set.
1244 *
1245 */
1246
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001247int jbd2_journal_set_features (journal_t *journal, unsigned long compat,
Dave Kleikamp470decc2006-10-11 01:20:57 -07001248 unsigned long ro, unsigned long incompat)
1249{
1250 journal_superblock_t *sb;
1251
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001252 if (jbd2_journal_check_used_features(journal, compat, ro, incompat))
Dave Kleikamp470decc2006-10-11 01:20:57 -07001253 return 1;
1254
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001255 if (!jbd2_journal_check_available_features(journal, compat, ro, incompat))
Dave Kleikamp470decc2006-10-11 01:20:57 -07001256 return 0;
1257
1258 jbd_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n",
1259 compat, ro, incompat);
1260
1261 sb = journal->j_superblock;
1262
1263 sb->s_feature_compat |= cpu_to_be32(compat);
1264 sb->s_feature_ro_compat |= cpu_to_be32(ro);
1265 sb->s_feature_incompat |= cpu_to_be32(incompat);
1266
1267 return 1;
1268}
1269
1270
1271/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001272 * int jbd2_journal_update_format () - Update on-disk journal structure.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001273 * @journal: Journal to act on.
1274 *
1275 * Given an initialised but unloaded journal struct, poke about in the
1276 * on-disk structure to update it to the most recent supported version.
1277 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001278int jbd2_journal_update_format (journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001279{
1280 journal_superblock_t *sb;
1281 int err;
1282
1283 err = journal_get_superblock(journal);
1284 if (err)
1285 return err;
1286
1287 sb = journal->j_superblock;
1288
1289 switch (be32_to_cpu(sb->s_header.h_blocktype)) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001290 case JBD2_SUPERBLOCK_V2:
Dave Kleikamp470decc2006-10-11 01:20:57 -07001291 return 0;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001292 case JBD2_SUPERBLOCK_V1:
Dave Kleikamp470decc2006-10-11 01:20:57 -07001293 return journal_convert_superblock_v1(journal, sb);
1294 default:
1295 break;
1296 }
1297 return -EINVAL;
1298}
1299
1300static int journal_convert_superblock_v1(journal_t *journal,
1301 journal_superblock_t *sb)
1302{
1303 int offset, blocksize;
1304 struct buffer_head *bh;
1305
1306 printk(KERN_WARNING
1307 "JBD: Converting superblock from version 1 to 2.\n");
1308
1309 /* Pre-initialise new fields to zero */
1310 offset = ((char *) &(sb->s_feature_compat)) - ((char *) sb);
1311 blocksize = be32_to_cpu(sb->s_blocksize);
1312 memset(&sb->s_feature_compat, 0, blocksize-offset);
1313
1314 sb->s_nr_users = cpu_to_be32(1);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001315 sb->s_header.h_blocktype = cpu_to_be32(JBD2_SUPERBLOCK_V2);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001316 journal->j_format_version = 2;
1317
1318 bh = journal->j_sb_buffer;
1319 BUFFER_TRACE(bh, "marking dirty");
1320 mark_buffer_dirty(bh);
1321 sync_dirty_buffer(bh);
1322 return 0;
1323}
1324
1325
1326/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001327 * int jbd2_journal_flush () - Flush journal
Dave Kleikamp470decc2006-10-11 01:20:57 -07001328 * @journal: Journal to act on.
1329 *
1330 * Flush all data for a given journal to disk and empty the journal.
1331 * Filesystems can use this when remounting readonly to ensure that
1332 * recovery does not need to happen on remount.
1333 */
1334
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001335int jbd2_journal_flush(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001336{
1337 int err = 0;
1338 transaction_t *transaction = NULL;
1339 unsigned long old_tail;
1340
1341 spin_lock(&journal->j_state_lock);
1342
1343 /* Force everything buffered to the log... */
1344 if (journal->j_running_transaction) {
1345 transaction = journal->j_running_transaction;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001346 __jbd2_log_start_commit(journal, transaction->t_tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001347 } else if (journal->j_committing_transaction)
1348 transaction = journal->j_committing_transaction;
1349
1350 /* Wait for the log commit to complete... */
1351 if (transaction) {
1352 tid_t tid = transaction->t_tid;
1353
1354 spin_unlock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001355 jbd2_log_wait_commit(journal, tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001356 } else {
1357 spin_unlock(&journal->j_state_lock);
1358 }
1359
1360 /* ...and flush everything in the log out to disk. */
1361 spin_lock(&journal->j_list_lock);
1362 while (!err && journal->j_checkpoint_transactions != NULL) {
1363 spin_unlock(&journal->j_list_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001364 err = jbd2_log_do_checkpoint(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001365 spin_lock(&journal->j_list_lock);
1366 }
1367 spin_unlock(&journal->j_list_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001368 jbd2_cleanup_journal_tail(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001369
1370 /* Finally, mark the journal as really needing no recovery.
1371 * This sets s_start==0 in the underlying superblock, which is
1372 * the magic code for a fully-recovered superblock. Any future
1373 * commits of data to the journal will restore the current
1374 * s_start value. */
1375 spin_lock(&journal->j_state_lock);
1376 old_tail = journal->j_tail;
1377 journal->j_tail = 0;
1378 spin_unlock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001379 jbd2_journal_update_superblock(journal, 1);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001380 spin_lock(&journal->j_state_lock);
1381 journal->j_tail = old_tail;
1382
1383 J_ASSERT(!journal->j_running_transaction);
1384 J_ASSERT(!journal->j_committing_transaction);
1385 J_ASSERT(!journal->j_checkpoint_transactions);
1386 J_ASSERT(journal->j_head == journal->j_tail);
1387 J_ASSERT(journal->j_tail_sequence == journal->j_transaction_sequence);
1388 spin_unlock(&journal->j_state_lock);
1389 return err;
1390}
1391
1392/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001393 * int jbd2_journal_wipe() - Wipe journal contents
Dave Kleikamp470decc2006-10-11 01:20:57 -07001394 * @journal: Journal to act on.
1395 * @write: flag (see below)
1396 *
1397 * Wipe out all of the contents of a journal, safely. This will produce
1398 * a warning if the journal contains any valid recovery information.
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001399 * Must be called between journal_init_*() and jbd2_journal_load().
Dave Kleikamp470decc2006-10-11 01:20:57 -07001400 *
1401 * If 'write' is non-zero, then we wipe out the journal on disk; otherwise
1402 * we merely suppress recovery.
1403 */
1404
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001405int jbd2_journal_wipe(journal_t *journal, int write)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001406{
1407 journal_superblock_t *sb;
1408 int err = 0;
1409
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001410 J_ASSERT (!(journal->j_flags & JBD2_LOADED));
Dave Kleikamp470decc2006-10-11 01:20:57 -07001411
1412 err = load_superblock(journal);
1413 if (err)
1414 return err;
1415
1416 sb = journal->j_superblock;
1417
1418 if (!journal->j_tail)
1419 goto no_recovery;
1420
1421 printk (KERN_WARNING "JBD: %s recovery information on journal\n",
1422 write ? "Clearing" : "Ignoring");
1423
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001424 err = jbd2_journal_skip_recovery(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001425 if (write)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001426 jbd2_journal_update_superblock(journal, 1);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001427
1428 no_recovery:
1429 return err;
1430}
1431
1432/*
1433 * journal_dev_name: format a character string to describe on what
1434 * device this journal is present.
1435 */
1436
1437static const char *journal_dev_name(journal_t *journal, char *buffer)
1438{
1439 struct block_device *bdev;
1440
1441 if (journal->j_inode)
1442 bdev = journal->j_inode->i_sb->s_bdev;
1443 else
1444 bdev = journal->j_dev;
1445
1446 return bdevname(bdev, buffer);
1447}
1448
1449/*
1450 * Journal abort has very specific semantics, which we describe
1451 * for journal abort.
1452 *
1453 * Two internal function, which provide abort to te jbd layer
1454 * itself are here.
1455 */
1456
1457/*
1458 * Quick version for internal journal use (doesn't lock the journal).
1459 * Aborts hard --- we mark the abort as occurred, but do _nothing_ else,
1460 * and don't attempt to make any other journal updates.
1461 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001462void __jbd2_journal_abort_hard(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001463{
1464 transaction_t *transaction;
1465 char b[BDEVNAME_SIZE];
1466
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001467 if (journal->j_flags & JBD2_ABORT)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001468 return;
1469
1470 printk(KERN_ERR "Aborting journal on device %s.\n",
1471 journal_dev_name(journal, b));
1472
1473 spin_lock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001474 journal->j_flags |= JBD2_ABORT;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001475 transaction = journal->j_running_transaction;
1476 if (transaction)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001477 __jbd2_log_start_commit(journal, transaction->t_tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001478 spin_unlock(&journal->j_state_lock);
1479}
1480
1481/* Soft abort: record the abort error status in the journal superblock,
1482 * but don't do any other IO. */
1483static void __journal_abort_soft (journal_t *journal, int errno)
1484{
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001485 if (journal->j_flags & JBD2_ABORT)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001486 return;
1487
1488 if (!journal->j_errno)
1489 journal->j_errno = errno;
1490
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001491 __jbd2_journal_abort_hard(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001492
1493 if (errno)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001494 jbd2_journal_update_superblock(journal, 1);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001495}
1496
1497/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001498 * void jbd2_journal_abort () - Shutdown the journal immediately.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001499 * @journal: the journal to shutdown.
1500 * @errno: an error number to record in the journal indicating
1501 * the reason for the shutdown.
1502 *
1503 * Perform a complete, immediate shutdown of the ENTIRE
1504 * journal (not of a single transaction). This operation cannot be
1505 * undone without closing and reopening the journal.
1506 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001507 * The jbd2_journal_abort function is intended to support higher level error
Dave Kleikamp470decc2006-10-11 01:20:57 -07001508 * recovery mechanisms such as the ext2/ext3 remount-readonly error
1509 * mode.
1510 *
1511 * Journal abort has very specific semantics. Any existing dirty,
1512 * unjournaled buffers in the main filesystem will still be written to
1513 * disk by bdflush, but the journaling mechanism will be suspended
1514 * immediately and no further transaction commits will be honoured.
1515 *
1516 * Any dirty, journaled buffers will be written back to disk without
1517 * hitting the journal. Atomicity cannot be guaranteed on an aborted
1518 * filesystem, but we _do_ attempt to leave as much data as possible
1519 * behind for fsck to use for cleanup.
1520 *
1521 * Any attempt to get a new transaction handle on a journal which is in
1522 * ABORT state will just result in an -EROFS error return. A
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001523 * jbd2_journal_stop on an existing handle will return -EIO if we have
Dave Kleikamp470decc2006-10-11 01:20:57 -07001524 * entered abort state during the update.
1525 *
1526 * Recursive transactions are not disturbed by journal abort until the
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001527 * final jbd2_journal_stop, which will receive the -EIO error.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001528 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001529 * Finally, the jbd2_journal_abort call allows the caller to supply an errno
Dave Kleikamp470decc2006-10-11 01:20:57 -07001530 * which will be recorded (if possible) in the journal superblock. This
1531 * allows a client to record failure conditions in the middle of a
1532 * transaction without having to complete the transaction to record the
1533 * failure to disk. ext3_error, for example, now uses this
1534 * functionality.
1535 *
1536 * Errors which originate from within the journaling layer will NOT
1537 * supply an errno; a null errno implies that absolutely no further
1538 * writes are done to the journal (unless there are any already in
1539 * progress).
1540 *
1541 */
1542
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001543void jbd2_journal_abort(journal_t *journal, int errno)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001544{
1545 __journal_abort_soft(journal, errno);
1546}
1547
1548/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001549 * int jbd2_journal_errno () - returns the journal's error state.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001550 * @journal: journal to examine.
1551 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001552 * This is the errno numbet set with jbd2_journal_abort(), the last
Dave Kleikamp470decc2006-10-11 01:20:57 -07001553 * time the journal was mounted - if the journal was stopped
1554 * without calling abort this will be 0.
1555 *
1556 * If the journal has been aborted on this mount time -EROFS will
1557 * be returned.
1558 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001559int jbd2_journal_errno(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001560{
1561 int err;
1562
1563 spin_lock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001564 if (journal->j_flags & JBD2_ABORT)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001565 err = -EROFS;
1566 else
1567 err = journal->j_errno;
1568 spin_unlock(&journal->j_state_lock);
1569 return err;
1570}
1571
1572/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001573 * int jbd2_journal_clear_err () - clears the journal's error state
Dave Kleikamp470decc2006-10-11 01:20:57 -07001574 * @journal: journal to act on.
1575 *
1576 * An error must be cleared or Acked to take a FS out of readonly
1577 * mode.
1578 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001579int jbd2_journal_clear_err(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001580{
1581 int err = 0;
1582
1583 spin_lock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001584 if (journal->j_flags & JBD2_ABORT)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001585 err = -EROFS;
1586 else
1587 journal->j_errno = 0;
1588 spin_unlock(&journal->j_state_lock);
1589 return err;
1590}
1591
1592/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001593 * void jbd2_journal_ack_err() - Ack journal err.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001594 * @journal: journal to act on.
1595 *
1596 * An error must be cleared or Acked to take a FS out of readonly
1597 * mode.
1598 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001599void jbd2_journal_ack_err(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001600{
1601 spin_lock(&journal->j_state_lock);
1602 if (journal->j_errno)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001603 journal->j_flags |= JBD2_ACK_ERR;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001604 spin_unlock(&journal->j_state_lock);
1605}
1606
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001607int jbd2_journal_blocks_per_page(struct inode *inode)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001608{
1609 return 1 << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
1610}
1611
1612/*
Zach Brownb517bea2006-10-11 01:21:08 -07001613 * helper functions to deal with 32 or 64bit block numbers.
1614 */
1615size_t journal_tag_bytes(journal_t *journal)
1616{
1617 if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT))
1618 return JBD_TAG_SIZE64;
1619 else
1620 return JBD_TAG_SIZE32;
1621}
1622
1623/*
Dave Kleikamp470decc2006-10-11 01:20:57 -07001624 * Simple support for retrying memory allocations. Introduced to help to
1625 * debug different VM deadlock avoidance strategies.
1626 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001627void * __jbd2_kmalloc (const char *where, size_t size, gfp_t flags, int retry)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001628{
1629 return kmalloc(size, flags | (retry ? __GFP_NOFAIL : 0));
1630}
1631
1632/*
1633 * jbd slab management: create 1k, 2k, 4k, 8k slabs as needed
1634 * and allocate frozen and commit buffers from these slabs.
1635 *
1636 * Reason for doing this is to avoid, SLAB_DEBUG - since it could
1637 * cause bh to cross page boundary.
1638 */
1639
1640#define JBD_MAX_SLABS 5
1641#define JBD_SLAB_INDEX(size) (size >> 11)
1642
1643static kmem_cache_t *jbd_slab[JBD_MAX_SLABS];
1644static const char *jbd_slab_names[JBD_MAX_SLABS] = {
Johann Lombardia920e942006-10-11 01:21:00 -07001645 "jbd2_1k", "jbd2_2k", "jbd2_4k", NULL, "jbd2_8k"
Dave Kleikamp470decc2006-10-11 01:20:57 -07001646};
1647
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001648static void jbd2_journal_destroy_jbd_slabs(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001649{
1650 int i;
1651
1652 for (i = 0; i < JBD_MAX_SLABS; i++) {
1653 if (jbd_slab[i])
1654 kmem_cache_destroy(jbd_slab[i]);
1655 jbd_slab[i] = NULL;
1656 }
1657}
1658
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001659static int jbd2_journal_create_jbd_slab(size_t slab_size)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001660{
1661 int i = JBD_SLAB_INDEX(slab_size);
1662
1663 BUG_ON(i >= JBD_MAX_SLABS);
1664
1665 /*
1666 * Check if we already have a slab created for this size
1667 */
1668 if (jbd_slab[i])
1669 return 0;
1670
1671 /*
1672 * Create a slab and force alignment to be same as slabsize -
1673 * this will make sure that allocations won't cross the page
1674 * boundary.
1675 */
1676 jbd_slab[i] = kmem_cache_create(jbd_slab_names[i],
1677 slab_size, slab_size, 0, NULL, NULL);
1678 if (!jbd_slab[i]) {
1679 printk(KERN_EMERG "JBD: no memory for jbd_slab cache\n");
1680 return -ENOMEM;
1681 }
1682 return 0;
1683}
1684
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001685void * jbd2_slab_alloc(size_t size, gfp_t flags)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001686{
1687 int idx;
1688
1689 idx = JBD_SLAB_INDEX(size);
1690 BUG_ON(jbd_slab[idx] == NULL);
1691 return kmem_cache_alloc(jbd_slab[idx], flags | __GFP_NOFAIL);
1692}
1693
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001694void jbd2_slab_free(void *ptr, size_t size)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001695{
1696 int idx;
1697
1698 idx = JBD_SLAB_INDEX(size);
1699 BUG_ON(jbd_slab[idx] == NULL);
1700 kmem_cache_free(jbd_slab[idx], ptr);
1701}
1702
1703/*
1704 * Journal_head storage management
1705 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001706static kmem_cache_t *jbd2_journal_head_cache;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001707#ifdef CONFIG_JBD_DEBUG
1708static atomic_t nr_journal_heads = ATOMIC_INIT(0);
1709#endif
1710
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001711static int journal_init_jbd2_journal_head_cache(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001712{
1713 int retval;
1714
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001715 J_ASSERT(jbd2_journal_head_cache == 0);
Johann Lombardia920e942006-10-11 01:21:00 -07001716 jbd2_journal_head_cache = kmem_cache_create("jbd2_journal_head",
Dave Kleikamp470decc2006-10-11 01:20:57 -07001717 sizeof(struct journal_head),
1718 0, /* offset */
1719 0, /* flags */
1720 NULL, /* ctor */
1721 NULL); /* dtor */
1722 retval = 0;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001723 if (jbd2_journal_head_cache == 0) {
Dave Kleikamp470decc2006-10-11 01:20:57 -07001724 retval = -ENOMEM;
1725 printk(KERN_EMERG "JBD: no memory for journal_head cache\n");
1726 }
1727 return retval;
1728}
1729
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001730static void jbd2_journal_destroy_jbd2_journal_head_cache(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001731{
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001732 J_ASSERT(jbd2_journal_head_cache != NULL);
1733 kmem_cache_destroy(jbd2_journal_head_cache);
1734 jbd2_journal_head_cache = NULL;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001735}
1736
1737/*
1738 * journal_head splicing and dicing
1739 */
1740static struct journal_head *journal_alloc_journal_head(void)
1741{
1742 struct journal_head *ret;
1743 static unsigned long last_warning;
1744
1745#ifdef CONFIG_JBD_DEBUG
1746 atomic_inc(&nr_journal_heads);
1747#endif
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001748 ret = kmem_cache_alloc(jbd2_journal_head_cache, GFP_NOFS);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001749 if (ret == 0) {
1750 jbd_debug(1, "out of memory for journal_head\n");
1751 if (time_after(jiffies, last_warning + 5*HZ)) {
1752 printk(KERN_NOTICE "ENOMEM in %s, retrying.\n",
1753 __FUNCTION__);
1754 last_warning = jiffies;
1755 }
1756 while (ret == 0) {
1757 yield();
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001758 ret = kmem_cache_alloc(jbd2_journal_head_cache, GFP_NOFS);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001759 }
1760 }
1761 return ret;
1762}
1763
1764static void journal_free_journal_head(struct journal_head *jh)
1765{
1766#ifdef CONFIG_JBD_DEBUG
1767 atomic_dec(&nr_journal_heads);
1768 memset(jh, JBD_POISON_FREE, sizeof(*jh));
1769#endif
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001770 kmem_cache_free(jbd2_journal_head_cache, jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001771}
1772
1773/*
1774 * A journal_head is attached to a buffer_head whenever JBD has an
1775 * interest in the buffer.
1776 *
1777 * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit
1778 * is set. This bit is tested in core kernel code where we need to take
1779 * JBD-specific actions. Testing the zeroness of ->b_private is not reliable
1780 * there.
1781 *
1782 * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one.
1783 *
1784 * When a buffer has its BH_JBD bit set it is immune from being released by
1785 * core kernel code, mainly via ->b_count.
1786 *
1787 * A journal_head may be detached from its buffer_head when the journal_head's
1788 * b_transaction, b_cp_transaction and b_next_transaction pointers are NULL.
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001789 * Various places in JBD call jbd2_journal_remove_journal_head() to indicate that the
Dave Kleikamp470decc2006-10-11 01:20:57 -07001790 * journal_head can be dropped if needed.
1791 *
1792 * Various places in the kernel want to attach a journal_head to a buffer_head
1793 * _before_ attaching the journal_head to a transaction. To protect the
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001794 * journal_head in this situation, jbd2_journal_add_journal_head elevates the
Dave Kleikamp470decc2006-10-11 01:20:57 -07001795 * journal_head's b_jcount refcount by one. The caller must call
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001796 * jbd2_journal_put_journal_head() to undo this.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001797 *
1798 * So the typical usage would be:
1799 *
1800 * (Attach a journal_head if needed. Increments b_jcount)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001801 * struct journal_head *jh = jbd2_journal_add_journal_head(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001802 * ...
1803 * jh->b_transaction = xxx;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001804 * jbd2_journal_put_journal_head(jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001805 *
1806 * Now, the journal_head's b_jcount is zero, but it is safe from being released
1807 * because it has a non-zero b_transaction.
1808 */
1809
1810/*
1811 * Give a buffer_head a journal_head.
1812 *
1813 * Doesn't need the journal lock.
1814 * May sleep.
1815 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001816struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001817{
1818 struct journal_head *jh;
1819 struct journal_head *new_jh = NULL;
1820
1821repeat:
1822 if (!buffer_jbd(bh)) {
1823 new_jh = journal_alloc_journal_head();
1824 memset(new_jh, 0, sizeof(*new_jh));
1825 }
1826
1827 jbd_lock_bh_journal_head(bh);
1828 if (buffer_jbd(bh)) {
1829 jh = bh2jh(bh);
1830 } else {
1831 J_ASSERT_BH(bh,
1832 (atomic_read(&bh->b_count) > 0) ||
1833 (bh->b_page && bh->b_page->mapping));
1834
1835 if (!new_jh) {
1836 jbd_unlock_bh_journal_head(bh);
1837 goto repeat;
1838 }
1839
1840 jh = new_jh;
1841 new_jh = NULL; /* We consumed it */
1842 set_buffer_jbd(bh);
1843 bh->b_private = jh;
1844 jh->b_bh = bh;
1845 get_bh(bh);
1846 BUFFER_TRACE(bh, "added journal_head");
1847 }
1848 jh->b_jcount++;
1849 jbd_unlock_bh_journal_head(bh);
1850 if (new_jh)
1851 journal_free_journal_head(new_jh);
1852 return bh->b_private;
1853}
1854
1855/*
1856 * Grab a ref against this buffer_head's journal_head. If it ended up not
1857 * having a journal_head, return NULL
1858 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001859struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001860{
1861 struct journal_head *jh = NULL;
1862
1863 jbd_lock_bh_journal_head(bh);
1864 if (buffer_jbd(bh)) {
1865 jh = bh2jh(bh);
1866 jh->b_jcount++;
1867 }
1868 jbd_unlock_bh_journal_head(bh);
1869 return jh;
1870}
1871
1872static void __journal_remove_journal_head(struct buffer_head *bh)
1873{
1874 struct journal_head *jh = bh2jh(bh);
1875
1876 J_ASSERT_JH(jh, jh->b_jcount >= 0);
1877
1878 get_bh(bh);
1879 if (jh->b_jcount == 0) {
1880 if (jh->b_transaction == NULL &&
1881 jh->b_next_transaction == NULL &&
1882 jh->b_cp_transaction == NULL) {
1883 J_ASSERT_JH(jh, jh->b_jlist == BJ_None);
1884 J_ASSERT_BH(bh, buffer_jbd(bh));
1885 J_ASSERT_BH(bh, jh2bh(jh) == bh);
1886 BUFFER_TRACE(bh, "remove journal_head");
1887 if (jh->b_frozen_data) {
1888 printk(KERN_WARNING "%s: freeing "
1889 "b_frozen_data\n",
1890 __FUNCTION__);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001891 jbd2_slab_free(jh->b_frozen_data, bh->b_size);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001892 }
1893 if (jh->b_committed_data) {
1894 printk(KERN_WARNING "%s: freeing "
1895 "b_committed_data\n",
1896 __FUNCTION__);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001897 jbd2_slab_free(jh->b_committed_data, bh->b_size);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001898 }
1899 bh->b_private = NULL;
1900 jh->b_bh = NULL; /* debug, really */
1901 clear_buffer_jbd(bh);
1902 __brelse(bh);
1903 journal_free_journal_head(jh);
1904 } else {
1905 BUFFER_TRACE(bh, "journal_head was locked");
1906 }
1907 }
1908}
1909
1910/*
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001911 * jbd2_journal_remove_journal_head(): if the buffer isn't attached to a transaction
Dave Kleikamp470decc2006-10-11 01:20:57 -07001912 * and has a zero b_jcount then remove and release its journal_head. If we did
1913 * see that the buffer is not used by any transaction we also "logically"
1914 * decrement ->b_count.
1915 *
1916 * We in fact take an additional increment on ->b_count as a convenience,
1917 * because the caller usually wants to do additional things with the bh
1918 * after calling here.
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001919 * The caller of jbd2_journal_remove_journal_head() *must* run __brelse(bh) at some
Dave Kleikamp470decc2006-10-11 01:20:57 -07001920 * time. Once the caller has run __brelse(), the buffer is eligible for
1921 * reaping by try_to_free_buffers().
1922 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001923void jbd2_journal_remove_journal_head(struct buffer_head *bh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001924{
1925 jbd_lock_bh_journal_head(bh);
1926 __journal_remove_journal_head(bh);
1927 jbd_unlock_bh_journal_head(bh);
1928}
1929
1930/*
1931 * Drop a reference on the passed journal_head. If it fell to zero then try to
1932 * release the journal_head from the buffer_head.
1933 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001934void jbd2_journal_put_journal_head(struct journal_head *jh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001935{
1936 struct buffer_head *bh = jh2bh(jh);
1937
1938 jbd_lock_bh_journal_head(bh);
1939 J_ASSERT_JH(jh, jh->b_jcount > 0);
1940 --jh->b_jcount;
1941 if (!jh->b_jcount && !jh->b_transaction) {
1942 __journal_remove_journal_head(bh);
1943 __brelse(bh);
1944 }
1945 jbd_unlock_bh_journal_head(bh);
1946}
1947
1948/*
1949 * /proc tunables
1950 */
1951#if defined(CONFIG_JBD_DEBUG)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001952int jbd2_journal_enable_debug;
1953EXPORT_SYMBOL(jbd2_journal_enable_debug);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001954#endif
1955
1956#if defined(CONFIG_JBD_DEBUG) && defined(CONFIG_PROC_FS)
1957
1958static struct proc_dir_entry *proc_jbd_debug;
1959
1960static int read_jbd_debug(char *page, char **start, off_t off,
1961 int count, int *eof, void *data)
1962{
1963 int ret;
1964
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001965 ret = sprintf(page + off, "%d\n", jbd2_journal_enable_debug);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001966 *eof = 1;
1967 return ret;
1968}
1969
1970static int write_jbd_debug(struct file *file, const char __user *buffer,
1971 unsigned long count, void *data)
1972{
1973 char buf[32];
1974
1975 if (count > ARRAY_SIZE(buf) - 1)
1976 count = ARRAY_SIZE(buf) - 1;
1977 if (copy_from_user(buf, buffer, count))
1978 return -EFAULT;
1979 buf[ARRAY_SIZE(buf) - 1] = '\0';
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001980 jbd2_journal_enable_debug = simple_strtoul(buf, NULL, 10);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001981 return count;
1982}
1983
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001984#define JBD_PROC_NAME "sys/fs/jbd2-debug"
Dave Kleikamp470decc2006-10-11 01:20:57 -07001985
1986static void __init create_jbd_proc_entry(void)
1987{
1988 proc_jbd_debug = create_proc_entry(JBD_PROC_NAME, 0644, NULL);
1989 if (proc_jbd_debug) {
1990 /* Why is this so hard? */
1991 proc_jbd_debug->read_proc = read_jbd_debug;
1992 proc_jbd_debug->write_proc = write_jbd_debug;
1993 }
1994}
1995
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001996static void __exit jbd2_remove_jbd_proc_entry(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001997{
1998 if (proc_jbd_debug)
1999 remove_proc_entry(JBD_PROC_NAME, NULL);
2000}
2001
2002#else
2003
2004#define create_jbd_proc_entry() do {} while (0)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002005#define jbd2_remove_jbd_proc_entry() do {} while (0)
Dave Kleikamp470decc2006-10-11 01:20:57 -07002006
2007#endif
2008
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002009kmem_cache_t *jbd2_handle_cache;
Dave Kleikamp470decc2006-10-11 01:20:57 -07002010
2011static int __init journal_init_handle_cache(void)
2012{
Johann Lombardia920e942006-10-11 01:21:00 -07002013 jbd2_handle_cache = kmem_cache_create("jbd2_journal_handle",
Dave Kleikamp470decc2006-10-11 01:20:57 -07002014 sizeof(handle_t),
2015 0, /* offset */
2016 0, /* flags */
2017 NULL, /* ctor */
2018 NULL); /* dtor */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002019 if (jbd2_handle_cache == NULL) {
Dave Kleikamp470decc2006-10-11 01:20:57 -07002020 printk(KERN_EMERG "JBD: failed to create handle cache\n");
2021 return -ENOMEM;
2022 }
2023 return 0;
2024}
2025
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002026static void jbd2_journal_destroy_handle_cache(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07002027{
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002028 if (jbd2_handle_cache)
2029 kmem_cache_destroy(jbd2_handle_cache);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002030}
2031
2032/*
2033 * Module startup and shutdown
2034 */
2035
2036static int __init journal_init_caches(void)
2037{
2038 int ret;
2039
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002040 ret = jbd2_journal_init_revoke_caches();
Dave Kleikamp470decc2006-10-11 01:20:57 -07002041 if (ret == 0)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002042 ret = journal_init_jbd2_journal_head_cache();
Dave Kleikamp470decc2006-10-11 01:20:57 -07002043 if (ret == 0)
2044 ret = journal_init_handle_cache();
2045 return ret;
2046}
2047
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002048static void jbd2_journal_destroy_caches(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07002049{
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002050 jbd2_journal_destroy_revoke_caches();
2051 jbd2_journal_destroy_jbd2_journal_head_cache();
2052 jbd2_journal_destroy_handle_cache();
2053 jbd2_journal_destroy_jbd_slabs();
Dave Kleikamp470decc2006-10-11 01:20:57 -07002054}
2055
2056static int __init journal_init(void)
2057{
2058 int ret;
2059
2060 BUILD_BUG_ON(sizeof(struct journal_superblock_s) != 1024);
2061
2062 ret = journal_init_caches();
2063 if (ret != 0)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002064 jbd2_journal_destroy_caches();
Dave Kleikamp470decc2006-10-11 01:20:57 -07002065 create_jbd_proc_entry();
2066 return ret;
2067}
2068
2069static void __exit journal_exit(void)
2070{
2071#ifdef CONFIG_JBD_DEBUG
2072 int n = atomic_read(&nr_journal_heads);
2073 if (n)
2074 printk(KERN_EMERG "JBD: leaked %d journal_heads!\n", n);
2075#endif
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002076 jbd2_remove_jbd_proc_entry();
2077 jbd2_journal_destroy_caches();
Dave Kleikamp470decc2006-10-11 01:20:57 -07002078}
2079
2080MODULE_LICENSE("GPL");
2081module_init(journal_init);
2082module_exit(journal_exit);
2083