blob: 96ba846992e934f476511bbfd40152868f211d8b [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>
Dave Kleikamp470decc2006-10-11 01:20:57 -070031#include <linux/init.h>
32#include <linux/mm.h>
Nigel Cunningham7dfb7102006-12-06 20:34:23 -080033#include <linux/freezer.h>
Dave Kleikamp470decc2006-10-11 01:20:57 -070034#include <linux/pagemap.h>
35#include <linux/kthread.h>
36#include <linux/poison.h>
37#include <linux/proc_fs.h>
Jose R. Santos0f49d5d2007-07-18 08:50:18 -040038#include <linux/debugfs.h>
Johann Lombardi8e85fb32008-01-28 23:58:27 -050039#include <linux/seq_file.h>
Dave Kleikamp470decc2006-10-11 01:20:57 -070040
41#include <asm/uaccess.h>
42#include <asm/page.h>
43
Mingming Caof7f4bcc2006-10-11 01:20:59 -070044EXPORT_SYMBOL(jbd2_journal_start);
45EXPORT_SYMBOL(jbd2_journal_restart);
46EXPORT_SYMBOL(jbd2_journal_extend);
47EXPORT_SYMBOL(jbd2_journal_stop);
48EXPORT_SYMBOL(jbd2_journal_lock_updates);
49EXPORT_SYMBOL(jbd2_journal_unlock_updates);
50EXPORT_SYMBOL(jbd2_journal_get_write_access);
51EXPORT_SYMBOL(jbd2_journal_get_create_access);
52EXPORT_SYMBOL(jbd2_journal_get_undo_access);
53EXPORT_SYMBOL(jbd2_journal_dirty_data);
54EXPORT_SYMBOL(jbd2_journal_dirty_metadata);
55EXPORT_SYMBOL(jbd2_journal_release_buffer);
56EXPORT_SYMBOL(jbd2_journal_forget);
Dave Kleikamp470decc2006-10-11 01:20:57 -070057#if 0
58EXPORT_SYMBOL(journal_sync_buffer);
59#endif
Mingming Caof7f4bcc2006-10-11 01:20:59 -070060EXPORT_SYMBOL(jbd2_journal_flush);
61EXPORT_SYMBOL(jbd2_journal_revoke);
Dave Kleikamp470decc2006-10-11 01:20:57 -070062
Mingming Caof7f4bcc2006-10-11 01:20:59 -070063EXPORT_SYMBOL(jbd2_journal_init_dev);
64EXPORT_SYMBOL(jbd2_journal_init_inode);
65EXPORT_SYMBOL(jbd2_journal_update_format);
66EXPORT_SYMBOL(jbd2_journal_check_used_features);
67EXPORT_SYMBOL(jbd2_journal_check_available_features);
68EXPORT_SYMBOL(jbd2_journal_set_features);
69EXPORT_SYMBOL(jbd2_journal_create);
70EXPORT_SYMBOL(jbd2_journal_load);
71EXPORT_SYMBOL(jbd2_journal_destroy);
72EXPORT_SYMBOL(jbd2_journal_update_superblock);
73EXPORT_SYMBOL(jbd2_journal_abort);
74EXPORT_SYMBOL(jbd2_journal_errno);
75EXPORT_SYMBOL(jbd2_journal_ack_err);
76EXPORT_SYMBOL(jbd2_journal_clear_err);
77EXPORT_SYMBOL(jbd2_log_wait_commit);
78EXPORT_SYMBOL(jbd2_journal_start_commit);
79EXPORT_SYMBOL(jbd2_journal_force_commit_nested);
80EXPORT_SYMBOL(jbd2_journal_wipe);
81EXPORT_SYMBOL(jbd2_journal_blocks_per_page);
82EXPORT_SYMBOL(jbd2_journal_invalidatepage);
83EXPORT_SYMBOL(jbd2_journal_try_to_free_buffers);
84EXPORT_SYMBOL(jbd2_journal_force_commit);
Dave Kleikamp470decc2006-10-11 01:20:57 -070085
86static int journal_convert_superblock_v1(journal_t *, journal_superblock_t *);
87static void __journal_abort_soft (journal_t *journal, int errno);
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
Pavel Emelianov97f06782007-05-08 00:30:42 -0700214static int jbd2_journal_start_thread(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700215{
Pavel Emelianov97f06782007-05-08 00:30:42 -0700216 struct task_struct *t;
217
218 t = kthread_run(kjournald2, journal, "kjournald2");
219 if (IS_ERR(t))
220 return PTR_ERR(t);
221
Dave Kleikamp470decc2006-10-11 01:20:57 -0700222 wait_event(journal->j_wait_done_commit, journal->j_task != 0);
Pavel Emelianov97f06782007-05-08 00:30:42 -0700223 return 0;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700224}
225
226static void journal_kill_thread(journal_t *journal)
227{
228 spin_lock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700229 journal->j_flags |= JBD2_UNMOUNT;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700230
231 while (journal->j_task) {
232 wake_up(&journal->j_wait_commit);
233 spin_unlock(&journal->j_state_lock);
234 wait_event(journal->j_wait_done_commit, journal->j_task == 0);
235 spin_lock(&journal->j_state_lock);
236 }
237 spin_unlock(&journal->j_state_lock);
238}
239
240/*
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700241 * jbd2_journal_write_metadata_buffer: write a metadata buffer to the journal.
Dave Kleikamp470decc2006-10-11 01:20:57 -0700242 *
243 * Writes a metadata buffer to a given disk block. The actual IO is not
244 * performed but a new buffer_head is constructed which labels the data
245 * to be written with the correct destination disk block.
246 *
247 * Any magic-number escaping which needs to be done will cause a
248 * copy-out here. If the buffer happens to start with the
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700249 * JBD2_MAGIC_NUMBER, then we can't write it to the log directly: the
Dave Kleikamp470decc2006-10-11 01:20:57 -0700250 * magic number is only written to the log for descripter blocks. In
251 * this case, we copy the data and replace the first word with 0, and we
252 * return a result code which indicates that this buffer needs to be
253 * marked as an escaped buffer in the corresponding log descriptor
254 * block. The missing word can then be restored when the block is read
255 * during recovery.
256 *
257 * If the source buffer has already been modified by a new transaction
258 * since we took the last commit snapshot, we use the frozen copy of
259 * that data for IO. If we end up using the existing buffer_head's data
260 * for the write, then we *have* to lock the buffer to prevent anyone
261 * else from using and possibly modifying it while the IO is in
262 * progress.
263 *
264 * The function returns a pointer to the buffer_heads to be used for IO.
265 *
266 * We assume that the journal has already been locked in this function.
267 *
268 * Return value:
269 * <0: Error
270 * >=0: Finished OK
271 *
272 * On success:
273 * Bit 0 set == escape performed on the data
274 * Bit 1 set == buffer copy-out performed (kfree the data after IO)
275 */
276
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700277int jbd2_journal_write_metadata_buffer(transaction_t *transaction,
Dave Kleikamp470decc2006-10-11 01:20:57 -0700278 struct journal_head *jh_in,
279 struct journal_head **jh_out,
Mingming Cao18eba7a2006-10-11 01:21:13 -0700280 unsigned long long blocknr)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700281{
282 int need_copy_out = 0;
283 int done_copy_out = 0;
284 int do_escape = 0;
285 char *mapped_data;
286 struct buffer_head *new_bh;
287 struct journal_head *new_jh;
288 struct page *new_page;
289 unsigned int new_offset;
290 struct buffer_head *bh_in = jh2bh(jh_in);
291
292 /*
293 * The buffer really shouldn't be locked: only the current committing
294 * transaction is allowed to write it, so nobody else is allowed
295 * to do any IO.
296 *
297 * akpm: except if we're journalling data, and write() output is
298 * also part of a shared mapping, and another thread has
299 * decided to launch a writepage() against this buffer.
300 */
301 J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in));
302
303 new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL);
304
305 /*
306 * If a new transaction has already done a buffer copy-out, then
307 * we use that version of the data for the commit.
308 */
309 jbd_lock_bh_state(bh_in);
310repeat:
311 if (jh_in->b_frozen_data) {
312 done_copy_out = 1;
313 new_page = virt_to_page(jh_in->b_frozen_data);
314 new_offset = offset_in_page(jh_in->b_frozen_data);
315 } else {
316 new_page = jh2bh(jh_in)->b_page;
317 new_offset = offset_in_page(jh2bh(jh_in)->b_data);
318 }
319
320 mapped_data = kmap_atomic(new_page, KM_USER0);
321 /*
322 * Check for escaping
323 */
324 if (*((__be32 *)(mapped_data + new_offset)) ==
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700325 cpu_to_be32(JBD2_MAGIC_NUMBER)) {
Dave Kleikamp470decc2006-10-11 01:20:57 -0700326 need_copy_out = 1;
327 do_escape = 1;
328 }
329 kunmap_atomic(mapped_data, KM_USER0);
330
331 /*
332 * Do we need to do a data copy?
333 */
334 if (need_copy_out && !done_copy_out) {
335 char *tmp;
336
337 jbd_unlock_bh_state(bh_in);
Mingming Caoaf1e76d2007-10-16 18:38:25 -0400338 tmp = jbd2_alloc(bh_in->b_size, GFP_NOFS);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700339 jbd_lock_bh_state(bh_in);
340 if (jh_in->b_frozen_data) {
Mingming Caoaf1e76d2007-10-16 18:38:25 -0400341 jbd2_free(tmp, bh_in->b_size);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700342 goto repeat;
343 }
344
345 jh_in->b_frozen_data = tmp;
346 mapped_data = kmap_atomic(new_page, KM_USER0);
347 memcpy(tmp, mapped_data + new_offset, jh2bh(jh_in)->b_size);
348 kunmap_atomic(mapped_data, KM_USER0);
349
350 new_page = virt_to_page(tmp);
351 new_offset = offset_in_page(tmp);
352 done_copy_out = 1;
353 }
354
355 /*
356 * Did we need to do an escaping? Now we've done all the
357 * copying, we can finally do so.
358 */
359 if (do_escape) {
360 mapped_data = kmap_atomic(new_page, KM_USER0);
361 *((unsigned int *)(mapped_data + new_offset)) = 0;
362 kunmap_atomic(mapped_data, KM_USER0);
363 }
364
365 /* keep subsequent assertions sane */
366 new_bh->b_state = 0;
367 init_buffer(new_bh, NULL, NULL);
368 atomic_set(&new_bh->b_count, 1);
369 jbd_unlock_bh_state(bh_in);
370
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700371 new_jh = jbd2_journal_add_journal_head(new_bh); /* This sleeps */
Dave Kleikamp470decc2006-10-11 01:20:57 -0700372
373 set_bh_page(new_bh, new_page, new_offset);
374 new_jh->b_transaction = NULL;
375 new_bh->b_size = jh2bh(jh_in)->b_size;
376 new_bh->b_bdev = transaction->t_journal->j_dev;
377 new_bh->b_blocknr = blocknr;
378 set_buffer_mapped(new_bh);
379 set_buffer_dirty(new_bh);
380
381 *jh_out = new_jh;
382
383 /*
384 * The to-be-written buffer needs to get moved to the io queue,
385 * and the original buffer whose contents we are shadowing or
386 * copying is moved to the transaction's shadow queue.
387 */
388 JBUFFER_TRACE(jh_in, "file as BJ_Shadow");
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700389 jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700390 JBUFFER_TRACE(new_jh, "file as BJ_IO");
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700391 jbd2_journal_file_buffer(new_jh, transaction, BJ_IO);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700392
393 return do_escape | (done_copy_out << 1);
394}
395
396/*
397 * Allocation code for the journal file. Manage the space left in the
398 * journal, so that we can begin checkpointing when appropriate.
399 */
400
401/*
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700402 * __jbd2_log_space_left: Return the number of free blocks left in the journal.
Dave Kleikamp470decc2006-10-11 01:20:57 -0700403 *
404 * Called with the journal already locked.
405 *
406 * Called under j_state_lock
407 */
408
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700409int __jbd2_log_space_left(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700410{
411 int left = journal->j_free;
412
413 assert_spin_locked(&journal->j_state_lock);
414
415 /*
416 * Be pessimistic here about the number of those free blocks which
417 * might be required for log descriptor control blocks.
418 */
419
420#define MIN_LOG_RESERVED_BLOCKS 32 /* Allow for rounding errors */
421
422 left -= MIN_LOG_RESERVED_BLOCKS;
423
424 if (left <= 0)
425 return 0;
426 left -= (left >> 3);
427 return left;
428}
429
430/*
431 * Called under j_state_lock. Returns true if a transaction was started.
432 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700433int __jbd2_log_start_commit(journal_t *journal, tid_t target)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700434{
435 /*
436 * Are we already doing a recent enough commit?
437 */
438 if (!tid_geq(journal->j_commit_request, target)) {
439 /*
440 * We want a new commit: OK, mark the request and wakup the
441 * commit thread. We do _not_ do the commit ourselves.
442 */
443
444 journal->j_commit_request = target;
445 jbd_debug(1, "JBD: requesting commit %d/%d\n",
446 journal->j_commit_request,
447 journal->j_commit_sequence);
448 wake_up(&journal->j_wait_commit);
449 return 1;
450 }
451 return 0;
452}
453
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700454int jbd2_log_start_commit(journal_t *journal, tid_t tid)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700455{
456 int ret;
457
458 spin_lock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700459 ret = __jbd2_log_start_commit(journal, tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700460 spin_unlock(&journal->j_state_lock);
461 return ret;
462}
463
464/*
465 * Force and wait upon a commit if the calling process is not within
466 * transaction. This is used for forcing out undo-protected data which contains
467 * bitmaps, when the fs is running out of space.
468 *
469 * We can only force the running transaction if we don't have an active handle;
470 * otherwise, we will deadlock.
471 *
472 * Returns true if a transaction was started.
473 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700474int jbd2_journal_force_commit_nested(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700475{
476 transaction_t *transaction = NULL;
477 tid_t tid;
478
479 spin_lock(&journal->j_state_lock);
480 if (journal->j_running_transaction && !current->journal_info) {
481 transaction = journal->j_running_transaction;
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700482 __jbd2_log_start_commit(journal, transaction->t_tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700483 } else if (journal->j_committing_transaction)
484 transaction = journal->j_committing_transaction;
485
486 if (!transaction) {
487 spin_unlock(&journal->j_state_lock);
488 return 0; /* Nothing to retry */
489 }
490
491 tid = transaction->t_tid;
492 spin_unlock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700493 jbd2_log_wait_commit(journal, tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700494 return 1;
495}
496
497/*
498 * Start a commit of the current running transaction (if any). Returns true
499 * if a transaction was started, and fills its tid in at *ptid
500 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700501int jbd2_journal_start_commit(journal_t *journal, tid_t *ptid)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700502{
503 int ret = 0;
504
505 spin_lock(&journal->j_state_lock);
506 if (journal->j_running_transaction) {
507 tid_t tid = journal->j_running_transaction->t_tid;
508
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700509 ret = __jbd2_log_start_commit(journal, tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700510 if (ret && ptid)
511 *ptid = tid;
512 } else if (journal->j_committing_transaction && ptid) {
513 /*
514 * If ext3_write_super() recently started a commit, then we
515 * have to wait for completion of that transaction
516 */
517 *ptid = journal->j_committing_transaction->t_tid;
518 ret = 1;
519 }
520 spin_unlock(&journal->j_state_lock);
521 return ret;
522}
523
524/*
525 * Wait for a specified commit to complete.
526 * The caller may not hold the journal lock.
527 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700528int jbd2_log_wait_commit(journal_t *journal, tid_t tid)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700529{
530 int err = 0;
531
Jose R. Santose23291b2007-07-18 08:57:06 -0400532#ifdef CONFIG_JBD2_DEBUG
Dave Kleikamp470decc2006-10-11 01:20:57 -0700533 spin_lock(&journal->j_state_lock);
534 if (!tid_geq(journal->j_commit_request, tid)) {
535 printk(KERN_EMERG
536 "%s: error: j_commit_request=%d, tid=%d\n",
537 __FUNCTION__, journal->j_commit_request, tid);
538 }
539 spin_unlock(&journal->j_state_lock);
540#endif
541 spin_lock(&journal->j_state_lock);
542 while (tid_gt(tid, journal->j_commit_sequence)) {
543 jbd_debug(1, "JBD: want %d, j_commit_sequence=%d\n",
544 tid, journal->j_commit_sequence);
545 wake_up(&journal->j_wait_commit);
546 spin_unlock(&journal->j_state_lock);
547 wait_event(journal->j_wait_done_commit,
548 !tid_gt(tid, journal->j_commit_sequence));
549 spin_lock(&journal->j_state_lock);
550 }
551 spin_unlock(&journal->j_state_lock);
552
553 if (unlikely(is_journal_aborted(journal))) {
554 printk(KERN_EMERG "journal commit I/O error\n");
555 err = -EIO;
556 }
557 return err;
558}
559
560/*
561 * Log buffer allocation routines:
562 */
563
Mingming Cao18eba7a2006-10-11 01:21:13 -0700564int jbd2_journal_next_log_block(journal_t *journal, unsigned long long *retp)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700565{
566 unsigned long blocknr;
567
568 spin_lock(&journal->j_state_lock);
569 J_ASSERT(journal->j_free > 1);
570
571 blocknr = journal->j_head;
572 journal->j_head++;
573 journal->j_free--;
574 if (journal->j_head == journal->j_last)
575 journal->j_head = journal->j_first;
576 spin_unlock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700577 return jbd2_journal_bmap(journal, blocknr, retp);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700578}
579
580/*
581 * Conversion of logical to physical block numbers for the journal
582 *
583 * On external journals the journal blocks are identity-mapped, so
584 * this is a no-op. If needed, we can use j_blk_offset - everything is
585 * ready.
586 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700587int jbd2_journal_bmap(journal_t *journal, unsigned long blocknr,
Mingming Cao18eba7a2006-10-11 01:21:13 -0700588 unsigned long long *retp)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700589{
590 int err = 0;
Mingming Cao18eba7a2006-10-11 01:21:13 -0700591 unsigned long long ret;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700592
593 if (journal->j_inode) {
594 ret = bmap(journal->j_inode, blocknr);
595 if (ret)
596 *retp = ret;
597 else {
598 char b[BDEVNAME_SIZE];
599
600 printk(KERN_ALERT "%s: journal block not found "
601 "at offset %lu on %s\n",
602 __FUNCTION__,
603 blocknr,
604 bdevname(journal->j_dev, b));
605 err = -EIO;
606 __journal_abort_soft(journal, err);
607 }
608 } else {
609 *retp = blocknr; /* +journal->j_blk_offset */
610 }
611 return err;
612}
613
614/*
615 * We play buffer_head aliasing tricks to write data/metadata blocks to
616 * the journal without copying their contents, but for journal
617 * descriptor blocks we do need to generate bona fide buffers.
618 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700619 * After the caller of jbd2_journal_get_descriptor_buffer() has finished modifying
Dave Kleikamp470decc2006-10-11 01:20:57 -0700620 * the buffer's contents they really should run flush_dcache_page(bh->b_page).
621 * But we don't bother doing that, so there will be coherency problems with
622 * mmaps of blockdevs which hold live JBD-controlled filesystems.
623 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700624struct journal_head *jbd2_journal_get_descriptor_buffer(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700625{
626 struct buffer_head *bh;
Mingming Cao18eba7a2006-10-11 01:21:13 -0700627 unsigned long long blocknr;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700628 int err;
629
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700630 err = jbd2_journal_next_log_block(journal, &blocknr);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700631
632 if (err)
633 return NULL;
634
635 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
636 lock_buffer(bh);
637 memset(bh->b_data, 0, journal->j_blocksize);
638 set_buffer_uptodate(bh);
639 unlock_buffer(bh);
640 BUFFER_TRACE(bh, "return this buffer");
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700641 return jbd2_journal_add_journal_head(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700642}
643
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500644struct jbd2_stats_proc_session {
645 journal_t *journal;
646 struct transaction_stats_s *stats;
647 int start;
648 int max;
649};
650
651static void *jbd2_history_skip_empty(struct jbd2_stats_proc_session *s,
652 struct transaction_stats_s *ts,
653 int first)
654{
655 if (ts == s->stats + s->max)
656 ts = s->stats;
657 if (!first && ts == s->stats + s->start)
658 return NULL;
659 while (ts->ts_type == 0) {
660 ts++;
661 if (ts == s->stats + s->max)
662 ts = s->stats;
663 if (ts == s->stats + s->start)
664 return NULL;
665 }
666 return ts;
667
668}
669
670static void *jbd2_seq_history_start(struct seq_file *seq, loff_t *pos)
671{
672 struct jbd2_stats_proc_session *s = seq->private;
673 struct transaction_stats_s *ts;
674 int l = *pos;
675
676 if (l == 0)
677 return SEQ_START_TOKEN;
678 ts = jbd2_history_skip_empty(s, s->stats + s->start, 1);
679 if (!ts)
680 return NULL;
681 l--;
682 while (l) {
683 ts = jbd2_history_skip_empty(s, ++ts, 0);
684 if (!ts)
685 break;
686 l--;
687 }
688 return ts;
689}
690
691static void *jbd2_seq_history_next(struct seq_file *seq, void *v, loff_t *pos)
692{
693 struct jbd2_stats_proc_session *s = seq->private;
694 struct transaction_stats_s *ts = v;
695
696 ++*pos;
697 if (v == SEQ_START_TOKEN)
698 return jbd2_history_skip_empty(s, s->stats + s->start, 1);
699 else
700 return jbd2_history_skip_empty(s, ++ts, 0);
701}
702
703static int jbd2_seq_history_show(struct seq_file *seq, void *v)
704{
705 struct transaction_stats_s *ts = v;
706 if (v == SEQ_START_TOKEN) {
707 seq_printf(seq, "%-4s %-5s %-5s %-5s %-5s %-5s %-5s %-6s %-5s "
708 "%-5s %-5s %-5s %-5s %-5s\n", "R/C", "tid",
709 "wait", "run", "lock", "flush", "log", "hndls",
710 "block", "inlog", "ctime", "write", "drop",
711 "close");
712 return 0;
713 }
714 if (ts->ts_type == JBD2_STATS_RUN)
715 seq_printf(seq, "%-4s %-5lu %-5u %-5u %-5u %-5u %-5u "
716 "%-6lu %-5lu %-5lu\n", "R", ts->ts_tid,
717 jiffies_to_msecs(ts->u.run.rs_wait),
718 jiffies_to_msecs(ts->u.run.rs_running),
719 jiffies_to_msecs(ts->u.run.rs_locked),
720 jiffies_to_msecs(ts->u.run.rs_flushing),
721 jiffies_to_msecs(ts->u.run.rs_logging),
722 ts->u.run.rs_handle_count,
723 ts->u.run.rs_blocks,
724 ts->u.run.rs_blocks_logged);
725 else if (ts->ts_type == JBD2_STATS_CHECKPOINT)
726 seq_printf(seq, "%-4s %-5lu %48s %-5u %-5lu %-5lu %-5lu\n",
727 "C", ts->ts_tid, " ",
728 jiffies_to_msecs(ts->u.chp.cs_chp_time),
729 ts->u.chp.cs_written, ts->u.chp.cs_dropped,
730 ts->u.chp.cs_forced_to_close);
731 else
732 J_ASSERT(0);
733 return 0;
734}
735
736static void jbd2_seq_history_stop(struct seq_file *seq, void *v)
737{
738}
739
740static struct seq_operations jbd2_seq_history_ops = {
741 .start = jbd2_seq_history_start,
742 .next = jbd2_seq_history_next,
743 .stop = jbd2_seq_history_stop,
744 .show = jbd2_seq_history_show,
745};
746
747static int jbd2_seq_history_open(struct inode *inode, struct file *file)
748{
749 journal_t *journal = PDE(inode)->data;
750 struct jbd2_stats_proc_session *s;
751 int rc, size;
752
753 s = kmalloc(sizeof(*s), GFP_KERNEL);
754 if (s == NULL)
755 return -ENOMEM;
756 size = sizeof(struct transaction_stats_s) * journal->j_history_max;
757 s->stats = kmalloc(size, GFP_KERNEL);
758 if (s->stats == NULL) {
759 kfree(s);
760 return -ENOMEM;
761 }
762 spin_lock(&journal->j_history_lock);
763 memcpy(s->stats, journal->j_history, size);
764 s->max = journal->j_history_max;
765 s->start = journal->j_history_cur % s->max;
766 spin_unlock(&journal->j_history_lock);
767
768 rc = seq_open(file, &jbd2_seq_history_ops);
769 if (rc == 0) {
770 struct seq_file *m = file->private_data;
771 m->private = s;
772 } else {
773 kfree(s->stats);
774 kfree(s);
775 }
776 return rc;
777
778}
779
780static int jbd2_seq_history_release(struct inode *inode, struct file *file)
781{
782 struct seq_file *seq = file->private_data;
783 struct jbd2_stats_proc_session *s = seq->private;
784
785 kfree(s->stats);
786 kfree(s);
787 return seq_release(inode, file);
788}
789
790static struct file_operations jbd2_seq_history_fops = {
791 .owner = THIS_MODULE,
792 .open = jbd2_seq_history_open,
793 .read = seq_read,
794 .llseek = seq_lseek,
795 .release = jbd2_seq_history_release,
796};
797
798static void *jbd2_seq_info_start(struct seq_file *seq, loff_t *pos)
799{
800 return *pos ? NULL : SEQ_START_TOKEN;
801}
802
803static void *jbd2_seq_info_next(struct seq_file *seq, void *v, loff_t *pos)
804{
805 return NULL;
806}
807
808static int jbd2_seq_info_show(struct seq_file *seq, void *v)
809{
810 struct jbd2_stats_proc_session *s = seq->private;
811
812 if (v != SEQ_START_TOKEN)
813 return 0;
814 seq_printf(seq, "%lu transaction, each upto %u blocks\n",
815 s->stats->ts_tid,
816 s->journal->j_max_transaction_buffers);
817 if (s->stats->ts_tid == 0)
818 return 0;
819 seq_printf(seq, "average: \n %ums waiting for transaction\n",
820 jiffies_to_msecs(s->stats->u.run.rs_wait / s->stats->ts_tid));
821 seq_printf(seq, " %ums running transaction\n",
822 jiffies_to_msecs(s->stats->u.run.rs_running / s->stats->ts_tid));
823 seq_printf(seq, " %ums transaction was being locked\n",
824 jiffies_to_msecs(s->stats->u.run.rs_locked / s->stats->ts_tid));
825 seq_printf(seq, " %ums flushing data (in ordered mode)\n",
826 jiffies_to_msecs(s->stats->u.run.rs_flushing / s->stats->ts_tid));
827 seq_printf(seq, " %ums logging transaction\n",
828 jiffies_to_msecs(s->stats->u.run.rs_logging / s->stats->ts_tid));
829 seq_printf(seq, " %lu handles per transaction\n",
830 s->stats->u.run.rs_handle_count / s->stats->ts_tid);
831 seq_printf(seq, " %lu blocks per transaction\n",
832 s->stats->u.run.rs_blocks / s->stats->ts_tid);
833 seq_printf(seq, " %lu logged blocks per transaction\n",
834 s->stats->u.run.rs_blocks_logged / s->stats->ts_tid);
835 return 0;
836}
837
838static void jbd2_seq_info_stop(struct seq_file *seq, void *v)
839{
840}
841
842static struct seq_operations jbd2_seq_info_ops = {
843 .start = jbd2_seq_info_start,
844 .next = jbd2_seq_info_next,
845 .stop = jbd2_seq_info_stop,
846 .show = jbd2_seq_info_show,
847};
848
849static int jbd2_seq_info_open(struct inode *inode, struct file *file)
850{
851 journal_t *journal = PDE(inode)->data;
852 struct jbd2_stats_proc_session *s;
853 int rc, size;
854
855 s = kmalloc(sizeof(*s), GFP_KERNEL);
856 if (s == NULL)
857 return -ENOMEM;
858 size = sizeof(struct transaction_stats_s);
859 s->stats = kmalloc(size, GFP_KERNEL);
860 if (s->stats == NULL) {
861 kfree(s);
862 return -ENOMEM;
863 }
864 spin_lock(&journal->j_history_lock);
865 memcpy(s->stats, &journal->j_stats, size);
866 s->journal = journal;
867 spin_unlock(&journal->j_history_lock);
868
869 rc = seq_open(file, &jbd2_seq_info_ops);
870 if (rc == 0) {
871 struct seq_file *m = file->private_data;
872 m->private = s;
873 } else {
874 kfree(s->stats);
875 kfree(s);
876 }
877 return rc;
878
879}
880
881static int jbd2_seq_info_release(struct inode *inode, struct file *file)
882{
883 struct seq_file *seq = file->private_data;
884 struct jbd2_stats_proc_session *s = seq->private;
885 kfree(s->stats);
886 kfree(s);
887 return seq_release(inode, file);
888}
889
890static struct file_operations jbd2_seq_info_fops = {
891 .owner = THIS_MODULE,
892 .open = jbd2_seq_info_open,
893 .read = seq_read,
894 .llseek = seq_lseek,
895 .release = jbd2_seq_info_release,
896};
897
898static struct proc_dir_entry *proc_jbd2_stats;
899
900static void jbd2_stats_proc_init(journal_t *journal)
901{
902 char name[BDEVNAME_SIZE];
903
904 snprintf(name, sizeof(name) - 1, "%s", bdevname(journal->j_dev, name));
905 journal->j_proc_entry = proc_mkdir(name, proc_jbd2_stats);
906 if (journal->j_proc_entry) {
907 struct proc_dir_entry *p;
908 p = create_proc_entry("history", S_IRUGO,
909 journal->j_proc_entry);
910 if (p) {
911 p->proc_fops = &jbd2_seq_history_fops;
912 p->data = journal;
913 p = create_proc_entry("info", S_IRUGO,
914 journal->j_proc_entry);
915 if (p) {
916 p->proc_fops = &jbd2_seq_info_fops;
917 p->data = journal;
918 }
919 }
920 }
921}
922
923static void jbd2_stats_proc_exit(journal_t *journal)
924{
925 char name[BDEVNAME_SIZE];
926
927 snprintf(name, sizeof(name) - 1, "%s", bdevname(journal->j_dev, name));
928 remove_proc_entry("info", journal->j_proc_entry);
929 remove_proc_entry("history", journal->j_proc_entry);
930 remove_proc_entry(name, proc_jbd2_stats);
931}
932
933static void journal_init_stats(journal_t *journal)
934{
935 int size;
936
937 if (!proc_jbd2_stats)
938 return;
939
940 journal->j_history_max = 100;
941 size = sizeof(struct transaction_stats_s) * journal->j_history_max;
942 journal->j_history = kzalloc(size, GFP_KERNEL);
943 if (!journal->j_history) {
944 journal->j_history_max = 0;
945 return;
946 }
947 spin_lock_init(&journal->j_history_lock);
948}
949
Dave Kleikamp470decc2006-10-11 01:20:57 -0700950/*
951 * Management for journal control blocks: functions to create and
952 * destroy journal_t structures, and to initialise and read existing
953 * journal blocks from disk. */
954
955/* First: create and setup a journal_t object in memory. We initialise
956 * very few fields yet: that has to wait until we have created the
957 * journal structures from from scratch, or loaded them from disk. */
958
959static journal_t * journal_init_common (void)
960{
961 journal_t *journal;
962 int err;
963
Mingming Caod802ffa2007-10-16 18:38:25 -0400964 journal = kzalloc(sizeof(*journal), GFP_KERNEL|__GFP_NOFAIL);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700965 if (!journal)
966 goto fail;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700967
968 init_waitqueue_head(&journal->j_wait_transaction_locked);
969 init_waitqueue_head(&journal->j_wait_logspace);
970 init_waitqueue_head(&journal->j_wait_done_commit);
971 init_waitqueue_head(&journal->j_wait_checkpoint);
972 init_waitqueue_head(&journal->j_wait_commit);
973 init_waitqueue_head(&journal->j_wait_updates);
974 mutex_init(&journal->j_barrier);
975 mutex_init(&journal->j_checkpoint_mutex);
976 spin_lock_init(&journal->j_revoke_lock);
977 spin_lock_init(&journal->j_list_lock);
978 spin_lock_init(&journal->j_state_lock);
979
Mingming Caocd02ff02007-10-16 18:38:25 -0400980 journal->j_commit_interval = (HZ * JBD2_DEFAULT_MAX_COMMIT_AGE);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700981
982 /* The journal is marked for error until we succeed with recovery! */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700983 journal->j_flags = JBD2_ABORT;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700984
985 /* Set up a default-sized revoke table for the new mount. */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700986 err = jbd2_journal_init_revoke(journal, JOURNAL_REVOKE_DEFAULT_HASH);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700987 if (err) {
988 kfree(journal);
989 goto fail;
990 }
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500991
992 journal_init_stats(journal);
993
Dave Kleikamp470decc2006-10-11 01:20:57 -0700994 return journal;
995fail:
996 return NULL;
997}
998
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700999/* jbd2_journal_init_dev and jbd2_journal_init_inode:
Dave Kleikamp470decc2006-10-11 01:20:57 -07001000 *
1001 * Create a journal structure assigned some fixed set of disk blocks to
1002 * the journal. We don't actually touch those disk blocks yet, but we
1003 * need to set up all of the mapping information to tell the journaling
1004 * system where the journal blocks are.
1005 *
1006 */
1007
1008/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001009 * journal_t * jbd2_journal_init_dev() - creates an initialises a journal structure
Dave Kleikamp470decc2006-10-11 01:20:57 -07001010 * @bdev: Block device on which to create the journal
1011 * @fs_dev: Device which hold journalled filesystem for this journal.
1012 * @start: Block nr Start of journal.
1013 * @len: Length of the journal in blocks.
1014 * @blocksize: blocksize of journalling device
1015 * @returns: a newly created journal_t *
1016 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001017 * jbd2_journal_init_dev creates a journal which maps a fixed contiguous
Dave Kleikamp470decc2006-10-11 01:20:57 -07001018 * range of blocks on an arbitrary block device.
1019 *
1020 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001021journal_t * jbd2_journal_init_dev(struct block_device *bdev,
Dave Kleikamp470decc2006-10-11 01:20:57 -07001022 struct block_device *fs_dev,
Mingming Cao18eba7a2006-10-11 01:21:13 -07001023 unsigned long long start, int len, int blocksize)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001024{
1025 journal_t *journal = journal_init_common();
1026 struct buffer_head *bh;
1027 int n;
1028
1029 if (!journal)
1030 return NULL;
1031
1032 /* journal descriptor can store up to n blocks -bzzz */
1033 journal->j_blocksize = blocksize;
1034 n = journal->j_blocksize / sizeof(journal_block_tag_t);
1035 journal->j_wbufsize = n;
1036 journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
1037 if (!journal->j_wbuf) {
1038 printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n",
1039 __FUNCTION__);
1040 kfree(journal);
1041 journal = NULL;
Dave Kleikamp5eb30792006-10-17 00:09:35 -07001042 goto out;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001043 }
1044 journal->j_dev = bdev;
1045 journal->j_fs_dev = fs_dev;
1046 journal->j_blk_offset = start;
1047 journal->j_maxlen = len;
Johann Lombardi8e85fb32008-01-28 23:58:27 -05001048 jbd2_stats_proc_init(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001049
1050 bh = __getblk(journal->j_dev, start, journal->j_blocksize);
1051 J_ASSERT(bh != NULL);
1052 journal->j_sb_buffer = bh;
1053 journal->j_superblock = (journal_superblock_t *)bh->b_data;
Dave Kleikamp5eb30792006-10-17 00:09:35 -07001054out:
Dave Kleikamp470decc2006-10-11 01:20:57 -07001055 return journal;
1056}
1057
1058/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001059 * journal_t * jbd2_journal_init_inode () - creates a journal which maps to a inode.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001060 * @inode: An inode to create the journal in
1061 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001062 * jbd2_journal_init_inode creates a journal which maps an on-disk inode as
Dave Kleikamp470decc2006-10-11 01:20:57 -07001063 * the journal. The inode must exist already, must support bmap() and
1064 * must have all data blocks preallocated.
1065 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001066journal_t * jbd2_journal_init_inode (struct inode *inode)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001067{
1068 struct buffer_head *bh;
1069 journal_t *journal = journal_init_common();
1070 int err;
1071 int n;
Mingming Cao18eba7a2006-10-11 01:21:13 -07001072 unsigned long long blocknr;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001073
1074 if (!journal)
1075 return NULL;
1076
1077 journal->j_dev = journal->j_fs_dev = inode->i_sb->s_bdev;
1078 journal->j_inode = inode;
1079 jbd_debug(1,
1080 "journal %p: inode %s/%ld, size %Ld, bits %d, blksize %ld\n",
1081 journal, inode->i_sb->s_id, inode->i_ino,
1082 (long long) inode->i_size,
1083 inode->i_sb->s_blocksize_bits, inode->i_sb->s_blocksize);
1084
1085 journal->j_maxlen = inode->i_size >> inode->i_sb->s_blocksize_bits;
1086 journal->j_blocksize = inode->i_sb->s_blocksize;
Johann Lombardi8e85fb32008-01-28 23:58:27 -05001087 jbd2_stats_proc_init(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001088
1089 /* journal descriptor can store up to n blocks -bzzz */
1090 n = journal->j_blocksize / sizeof(journal_block_tag_t);
1091 journal->j_wbufsize = n;
1092 journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
1093 if (!journal->j_wbuf) {
1094 printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n",
1095 __FUNCTION__);
1096 kfree(journal);
1097 return NULL;
1098 }
1099
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001100 err = jbd2_journal_bmap(journal, 0, &blocknr);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001101 /* If that failed, give up */
1102 if (err) {
1103 printk(KERN_ERR "%s: Cannnot locate journal superblock\n",
1104 __FUNCTION__);
1105 kfree(journal);
1106 return NULL;
1107 }
1108
1109 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
1110 J_ASSERT(bh != NULL);
1111 journal->j_sb_buffer = bh;
1112 journal->j_superblock = (journal_superblock_t *)bh->b_data;
1113
1114 return journal;
1115}
1116
1117/*
1118 * If the journal init or create aborts, we need to mark the journal
1119 * superblock as being NULL to prevent the journal destroy from writing
1120 * back a bogus superblock.
1121 */
1122static void journal_fail_superblock (journal_t *journal)
1123{
1124 struct buffer_head *bh = journal->j_sb_buffer;
1125 brelse(bh);
1126 journal->j_sb_buffer = NULL;
1127}
1128
1129/*
1130 * Given a journal_t structure, initialise the various fields for
1131 * startup of a new journaling session. We use this both when creating
1132 * a journal, and after recovering an old journal to reset it for
1133 * subsequent use.
1134 */
1135
1136static int journal_reset(journal_t *journal)
1137{
1138 journal_superblock_t *sb = journal->j_superblock;
Mingming Cao18eba7a2006-10-11 01:21:13 -07001139 unsigned long long first, last;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001140
1141 first = be32_to_cpu(sb->s_first);
1142 last = be32_to_cpu(sb->s_maxlen);
1143
1144 journal->j_first = first;
1145 journal->j_last = last;
1146
1147 journal->j_head = first;
1148 journal->j_tail = first;
1149 journal->j_free = last - first;
1150
1151 journal->j_tail_sequence = journal->j_transaction_sequence;
1152 journal->j_commit_sequence = journal->j_transaction_sequence - 1;
1153 journal->j_commit_request = journal->j_commit_sequence;
1154
1155 journal->j_max_transaction_buffers = journal->j_maxlen / 4;
1156
1157 /* Add the dynamic fields and write it to disk. */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001158 jbd2_journal_update_superblock(journal, 1);
Pavel Emelianov97f06782007-05-08 00:30:42 -07001159 return jbd2_journal_start_thread(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001160}
1161
1162/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001163 * int jbd2_journal_create() - Initialise the new journal file
Dave Kleikamp470decc2006-10-11 01:20:57 -07001164 * @journal: Journal to create. This structure must have been initialised
1165 *
1166 * Given a journal_t structure which tells us which disk blocks we can
1167 * use, create a new journal superblock and initialise all of the
1168 * journal fields from scratch.
1169 **/
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001170int jbd2_journal_create(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001171{
Mingming Cao18eba7a2006-10-11 01:21:13 -07001172 unsigned long long blocknr;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001173 struct buffer_head *bh;
1174 journal_superblock_t *sb;
1175 int i, err;
1176
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001177 if (journal->j_maxlen < JBD2_MIN_JOURNAL_BLOCKS) {
Dave Kleikamp470decc2006-10-11 01:20:57 -07001178 printk (KERN_ERR "Journal length (%d blocks) too short.\n",
1179 journal->j_maxlen);
1180 journal_fail_superblock(journal);
1181 return -EINVAL;
1182 }
1183
1184 if (journal->j_inode == NULL) {
1185 /*
1186 * We don't know what block to start at!
1187 */
1188 printk(KERN_EMERG
1189 "%s: creation of journal on external device!\n",
1190 __FUNCTION__);
1191 BUG();
1192 }
1193
1194 /* Zero out the entire journal on disk. We cannot afford to
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001195 have any blocks on disk beginning with JBD2_MAGIC_NUMBER. */
Dave Kleikamp470decc2006-10-11 01:20:57 -07001196 jbd_debug(1, "JBD: Zeroing out journal blocks...\n");
1197 for (i = 0; i < journal->j_maxlen; i++) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001198 err = jbd2_journal_bmap(journal, i, &blocknr);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001199 if (err)
1200 return err;
1201 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
1202 lock_buffer(bh);
1203 memset (bh->b_data, 0, journal->j_blocksize);
1204 BUFFER_TRACE(bh, "marking dirty");
1205 mark_buffer_dirty(bh);
1206 BUFFER_TRACE(bh, "marking uptodate");
1207 set_buffer_uptodate(bh);
1208 unlock_buffer(bh);
1209 __brelse(bh);
1210 }
1211
1212 sync_blockdev(journal->j_dev);
1213 jbd_debug(1, "JBD: journal cleared.\n");
1214
1215 /* OK, fill in the initial static fields in the new superblock */
1216 sb = journal->j_superblock;
1217
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001218 sb->s_header.h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER);
1219 sb->s_header.h_blocktype = cpu_to_be32(JBD2_SUPERBLOCK_V2);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001220
1221 sb->s_blocksize = cpu_to_be32(journal->j_blocksize);
1222 sb->s_maxlen = cpu_to_be32(journal->j_maxlen);
1223 sb->s_first = cpu_to_be32(1);
1224
1225 journal->j_transaction_sequence = 1;
1226
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001227 journal->j_flags &= ~JBD2_ABORT;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001228 journal->j_format_version = 2;
1229
1230 return journal_reset(journal);
1231}
1232
1233/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001234 * void jbd2_journal_update_superblock() - Update journal sb on disk.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001235 * @journal: The journal to update.
1236 * @wait: Set to '0' if you don't want to wait for IO completion.
1237 *
1238 * Update a journal's dynamic superblock fields and write it to disk,
1239 * optionally waiting for the IO to complete.
1240 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001241void jbd2_journal_update_superblock(journal_t *journal, int wait)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001242{
1243 journal_superblock_t *sb = journal->j_superblock;
1244 struct buffer_head *bh = journal->j_sb_buffer;
1245
1246 /*
1247 * As a special case, if the on-disk copy is already marked as needing
1248 * no recovery (s_start == 0) and there are no outstanding transactions
1249 * in the filesystem, then we can safely defer the superblock update
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001250 * until the next commit by setting JBD2_FLUSHED. This avoids
Dave Kleikamp470decc2006-10-11 01:20:57 -07001251 * attempting a write to a potential-readonly device.
1252 */
1253 if (sb->s_start == 0 && journal->j_tail_sequence ==
1254 journal->j_transaction_sequence) {
1255 jbd_debug(1,"JBD: Skipping superblock update on recovered sb "
1256 "(start %ld, seq %d, errno %d)\n",
1257 journal->j_tail, journal->j_tail_sequence,
1258 journal->j_errno);
1259 goto out;
1260 }
1261
1262 spin_lock(&journal->j_state_lock);
1263 jbd_debug(1,"JBD: updating superblock (start %ld, seq %d, errno %d)\n",
1264 journal->j_tail, journal->j_tail_sequence, journal->j_errno);
1265
1266 sb->s_sequence = cpu_to_be32(journal->j_tail_sequence);
1267 sb->s_start = cpu_to_be32(journal->j_tail);
1268 sb->s_errno = cpu_to_be32(journal->j_errno);
1269 spin_unlock(&journal->j_state_lock);
1270
1271 BUFFER_TRACE(bh, "marking dirty");
1272 mark_buffer_dirty(bh);
1273 if (wait)
1274 sync_dirty_buffer(bh);
1275 else
1276 ll_rw_block(SWRITE, 1, &bh);
1277
1278out:
1279 /* If we have just flushed the log (by marking s_start==0), then
1280 * any future commit will have to be careful to update the
1281 * superblock again to re-record the true start of the log. */
1282
1283 spin_lock(&journal->j_state_lock);
1284 if (sb->s_start)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001285 journal->j_flags &= ~JBD2_FLUSHED;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001286 else
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001287 journal->j_flags |= JBD2_FLUSHED;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001288 spin_unlock(&journal->j_state_lock);
1289}
1290
1291/*
1292 * Read the superblock for a given journal, performing initial
1293 * validation of the format.
1294 */
1295
1296static int journal_get_superblock(journal_t *journal)
1297{
1298 struct buffer_head *bh;
1299 journal_superblock_t *sb;
1300 int err = -EIO;
1301
1302 bh = journal->j_sb_buffer;
1303
1304 J_ASSERT(bh != NULL);
1305 if (!buffer_uptodate(bh)) {
1306 ll_rw_block(READ, 1, &bh);
1307 wait_on_buffer(bh);
1308 if (!buffer_uptodate(bh)) {
1309 printk (KERN_ERR
1310 "JBD: IO error reading journal superblock\n");
1311 goto out;
1312 }
1313 }
1314
1315 sb = journal->j_superblock;
1316
1317 err = -EINVAL;
1318
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001319 if (sb->s_header.h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER) ||
Dave Kleikamp470decc2006-10-11 01:20:57 -07001320 sb->s_blocksize != cpu_to_be32(journal->j_blocksize)) {
1321 printk(KERN_WARNING "JBD: no valid journal superblock found\n");
1322 goto out;
1323 }
1324
1325 switch(be32_to_cpu(sb->s_header.h_blocktype)) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001326 case JBD2_SUPERBLOCK_V1:
Dave Kleikamp470decc2006-10-11 01:20:57 -07001327 journal->j_format_version = 1;
1328 break;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001329 case JBD2_SUPERBLOCK_V2:
Dave Kleikamp470decc2006-10-11 01:20:57 -07001330 journal->j_format_version = 2;
1331 break;
1332 default:
1333 printk(KERN_WARNING "JBD: unrecognised superblock format ID\n");
1334 goto out;
1335 }
1336
1337 if (be32_to_cpu(sb->s_maxlen) < journal->j_maxlen)
1338 journal->j_maxlen = be32_to_cpu(sb->s_maxlen);
1339 else if (be32_to_cpu(sb->s_maxlen) > journal->j_maxlen) {
1340 printk (KERN_WARNING "JBD: journal file too short\n");
1341 goto out;
1342 }
1343
1344 return 0;
1345
1346out:
1347 journal_fail_superblock(journal);
1348 return err;
1349}
1350
1351/*
1352 * Load the on-disk journal superblock and read the key fields into the
1353 * journal_t.
1354 */
1355
1356static int load_superblock(journal_t *journal)
1357{
1358 int err;
1359 journal_superblock_t *sb;
1360
1361 err = journal_get_superblock(journal);
1362 if (err)
1363 return err;
1364
1365 sb = journal->j_superblock;
1366
1367 journal->j_tail_sequence = be32_to_cpu(sb->s_sequence);
1368 journal->j_tail = be32_to_cpu(sb->s_start);
1369 journal->j_first = be32_to_cpu(sb->s_first);
1370 journal->j_last = be32_to_cpu(sb->s_maxlen);
1371 journal->j_errno = be32_to_cpu(sb->s_errno);
1372
1373 return 0;
1374}
1375
1376
1377/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001378 * int jbd2_journal_load() - Read journal from disk.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001379 * @journal: Journal to act on.
1380 *
1381 * Given a journal_t structure which tells us which disk blocks contain
1382 * a journal, read the journal from disk to initialise the in-memory
1383 * structures.
1384 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001385int jbd2_journal_load(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001386{
1387 int err;
1388 journal_superblock_t *sb;
1389
1390 err = load_superblock(journal);
1391 if (err)
1392 return err;
1393
1394 sb = journal->j_superblock;
1395 /* If this is a V2 superblock, then we have to check the
1396 * features flags on it. */
1397
1398 if (journal->j_format_version >= 2) {
1399 if ((sb->s_feature_ro_compat &
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001400 ~cpu_to_be32(JBD2_KNOWN_ROCOMPAT_FEATURES)) ||
Dave Kleikamp470decc2006-10-11 01:20:57 -07001401 (sb->s_feature_incompat &
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001402 ~cpu_to_be32(JBD2_KNOWN_INCOMPAT_FEATURES))) {
Dave Kleikamp470decc2006-10-11 01:20:57 -07001403 printk (KERN_WARNING
1404 "JBD: Unrecognised features on journal\n");
1405 return -EINVAL;
1406 }
1407 }
1408
Dave Kleikamp470decc2006-10-11 01:20:57 -07001409 /* Let the recovery code check whether it needs to recover any
1410 * data from the journal. */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001411 if (jbd2_journal_recover(journal))
Dave Kleikamp470decc2006-10-11 01:20:57 -07001412 goto recovery_error;
1413
1414 /* OK, we've finished with the dynamic journal bits:
1415 * reinitialise the dynamic contents of the superblock in memory
1416 * and reset them on disk. */
1417 if (journal_reset(journal))
1418 goto recovery_error;
1419
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001420 journal->j_flags &= ~JBD2_ABORT;
1421 journal->j_flags |= JBD2_LOADED;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001422 return 0;
1423
1424recovery_error:
1425 printk (KERN_WARNING "JBD: recovery failed\n");
1426 return -EIO;
1427}
1428
1429/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001430 * void jbd2_journal_destroy() - Release a journal_t structure.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001431 * @journal: Journal to act on.
1432 *
1433 * Release a journal_t structure once it is no longer in use by the
1434 * journaled object.
1435 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001436void jbd2_journal_destroy(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001437{
1438 /* Wait for the commit thread to wake up and die. */
1439 journal_kill_thread(journal);
1440
1441 /* Force a final log commit */
1442 if (journal->j_running_transaction)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001443 jbd2_journal_commit_transaction(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001444
1445 /* Force any old transactions to disk */
1446
1447 /* Totally anal locking here... */
1448 spin_lock(&journal->j_list_lock);
1449 while (journal->j_checkpoint_transactions != NULL) {
1450 spin_unlock(&journal->j_list_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001451 jbd2_log_do_checkpoint(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001452 spin_lock(&journal->j_list_lock);
1453 }
1454
1455 J_ASSERT(journal->j_running_transaction == NULL);
1456 J_ASSERT(journal->j_committing_transaction == NULL);
1457 J_ASSERT(journal->j_checkpoint_transactions == NULL);
1458 spin_unlock(&journal->j_list_lock);
1459
1460 /* We can now mark the journal as empty. */
1461 journal->j_tail = 0;
1462 journal->j_tail_sequence = ++journal->j_transaction_sequence;
1463 if (journal->j_sb_buffer) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001464 jbd2_journal_update_superblock(journal, 1);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001465 brelse(journal->j_sb_buffer);
1466 }
1467
Johann Lombardi8e85fb32008-01-28 23:58:27 -05001468 if (journal->j_proc_entry)
1469 jbd2_stats_proc_exit(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001470 if (journal->j_inode)
1471 iput(journal->j_inode);
1472 if (journal->j_revoke)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001473 jbd2_journal_destroy_revoke(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001474 kfree(journal->j_wbuf);
1475 kfree(journal);
1476}
1477
1478
1479/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001480 *int jbd2_journal_check_used_features () - Check if features specified are used.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001481 * @journal: Journal to check.
1482 * @compat: bitmask of compatible features
1483 * @ro: bitmask of features that force read-only mount
1484 * @incompat: bitmask of incompatible features
1485 *
1486 * Check whether the journal uses all of a given set of
1487 * features. Return true (non-zero) if it does.
1488 **/
1489
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001490int jbd2_journal_check_used_features (journal_t *journal, unsigned long compat,
Dave Kleikamp470decc2006-10-11 01:20:57 -07001491 unsigned long ro, unsigned long incompat)
1492{
1493 journal_superblock_t *sb;
1494
1495 if (!compat && !ro && !incompat)
1496 return 1;
1497 if (journal->j_format_version == 1)
1498 return 0;
1499
1500 sb = journal->j_superblock;
1501
1502 if (((be32_to_cpu(sb->s_feature_compat) & compat) == compat) &&
1503 ((be32_to_cpu(sb->s_feature_ro_compat) & ro) == ro) &&
1504 ((be32_to_cpu(sb->s_feature_incompat) & incompat) == incompat))
1505 return 1;
1506
1507 return 0;
1508}
1509
1510/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001511 * int jbd2_journal_check_available_features() - Check feature set in journalling layer
Dave Kleikamp470decc2006-10-11 01:20:57 -07001512 * @journal: Journal to check.
1513 * @compat: bitmask of compatible features
1514 * @ro: bitmask of features that force read-only mount
1515 * @incompat: bitmask of incompatible features
1516 *
1517 * Check whether the journaling code supports the use of
1518 * all of a given set of features on this journal. Return true
1519 * (non-zero) if it can. */
1520
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001521int jbd2_journal_check_available_features (journal_t *journal, unsigned long compat,
Dave Kleikamp470decc2006-10-11 01:20:57 -07001522 unsigned long ro, unsigned long incompat)
1523{
1524 journal_superblock_t *sb;
1525
1526 if (!compat && !ro && !incompat)
1527 return 1;
1528
1529 sb = journal->j_superblock;
1530
1531 /* We can support any known requested features iff the
1532 * superblock is in version 2. Otherwise we fail to support any
1533 * extended sb features. */
1534
1535 if (journal->j_format_version != 2)
1536 return 0;
1537
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001538 if ((compat & JBD2_KNOWN_COMPAT_FEATURES) == compat &&
1539 (ro & JBD2_KNOWN_ROCOMPAT_FEATURES) == ro &&
1540 (incompat & JBD2_KNOWN_INCOMPAT_FEATURES) == incompat)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001541 return 1;
1542
1543 return 0;
1544}
1545
1546/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001547 * int jbd2_journal_set_features () - Mark a given journal feature in the superblock
Dave Kleikamp470decc2006-10-11 01:20:57 -07001548 * @journal: Journal to act on.
1549 * @compat: bitmask of compatible features
1550 * @ro: bitmask of features that force read-only mount
1551 * @incompat: bitmask of incompatible features
1552 *
1553 * Mark a given journal feature as present on the
1554 * superblock. Returns true if the requested features could be set.
1555 *
1556 */
1557
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001558int jbd2_journal_set_features (journal_t *journal, unsigned long compat,
Dave Kleikamp470decc2006-10-11 01:20:57 -07001559 unsigned long ro, unsigned long incompat)
1560{
1561 journal_superblock_t *sb;
1562
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001563 if (jbd2_journal_check_used_features(journal, compat, ro, incompat))
Dave Kleikamp470decc2006-10-11 01:20:57 -07001564 return 1;
1565
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001566 if (!jbd2_journal_check_available_features(journal, compat, ro, incompat))
Dave Kleikamp470decc2006-10-11 01:20:57 -07001567 return 0;
1568
1569 jbd_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n",
1570 compat, ro, incompat);
1571
1572 sb = journal->j_superblock;
1573
1574 sb->s_feature_compat |= cpu_to_be32(compat);
1575 sb->s_feature_ro_compat |= cpu_to_be32(ro);
1576 sb->s_feature_incompat |= cpu_to_be32(incompat);
1577
1578 return 1;
1579}
1580
Girish Shilamkar818d2762008-01-28 23:58:27 -05001581/*
1582 * jbd2_journal_clear_features () - Clear a given journal feature in the
1583 * superblock
1584 * @journal: Journal to act on.
1585 * @compat: bitmask of compatible features
1586 * @ro: bitmask of features that force read-only mount
1587 * @incompat: bitmask of incompatible features
1588 *
1589 * Clear a given journal feature as present on the
1590 * superblock.
1591 */
1592void jbd2_journal_clear_features(journal_t *journal, unsigned long compat,
1593 unsigned long ro, unsigned long incompat)
1594{
1595 journal_superblock_t *sb;
1596
1597 jbd_debug(1, "Clear features 0x%lx/0x%lx/0x%lx\n",
1598 compat, ro, incompat);
1599
1600 sb = journal->j_superblock;
1601
1602 sb->s_feature_compat &= ~cpu_to_be32(compat);
1603 sb->s_feature_ro_compat &= ~cpu_to_be32(ro);
1604 sb->s_feature_incompat &= ~cpu_to_be32(incompat);
1605}
1606EXPORT_SYMBOL(jbd2_journal_clear_features);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001607
1608/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001609 * int jbd2_journal_update_format () - Update on-disk journal structure.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001610 * @journal: Journal to act on.
1611 *
1612 * Given an initialised but unloaded journal struct, poke about in the
1613 * on-disk structure to update it to the most recent supported version.
1614 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001615int jbd2_journal_update_format (journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001616{
1617 journal_superblock_t *sb;
1618 int err;
1619
1620 err = journal_get_superblock(journal);
1621 if (err)
1622 return err;
1623
1624 sb = journal->j_superblock;
1625
1626 switch (be32_to_cpu(sb->s_header.h_blocktype)) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001627 case JBD2_SUPERBLOCK_V2:
Dave Kleikamp470decc2006-10-11 01:20:57 -07001628 return 0;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001629 case JBD2_SUPERBLOCK_V1:
Dave Kleikamp470decc2006-10-11 01:20:57 -07001630 return journal_convert_superblock_v1(journal, sb);
1631 default:
1632 break;
1633 }
1634 return -EINVAL;
1635}
1636
1637static int journal_convert_superblock_v1(journal_t *journal,
1638 journal_superblock_t *sb)
1639{
1640 int offset, blocksize;
1641 struct buffer_head *bh;
1642
1643 printk(KERN_WARNING
1644 "JBD: Converting superblock from version 1 to 2.\n");
1645
1646 /* Pre-initialise new fields to zero */
1647 offset = ((char *) &(sb->s_feature_compat)) - ((char *) sb);
1648 blocksize = be32_to_cpu(sb->s_blocksize);
1649 memset(&sb->s_feature_compat, 0, blocksize-offset);
1650
1651 sb->s_nr_users = cpu_to_be32(1);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001652 sb->s_header.h_blocktype = cpu_to_be32(JBD2_SUPERBLOCK_V2);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001653 journal->j_format_version = 2;
1654
1655 bh = journal->j_sb_buffer;
1656 BUFFER_TRACE(bh, "marking dirty");
1657 mark_buffer_dirty(bh);
1658 sync_dirty_buffer(bh);
1659 return 0;
1660}
1661
1662
1663/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001664 * int jbd2_journal_flush () - Flush journal
Dave Kleikamp470decc2006-10-11 01:20:57 -07001665 * @journal: Journal to act on.
1666 *
1667 * Flush all data for a given journal to disk and empty the journal.
1668 * Filesystems can use this when remounting readonly to ensure that
1669 * recovery does not need to happen on remount.
1670 */
1671
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001672int jbd2_journal_flush(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001673{
1674 int err = 0;
1675 transaction_t *transaction = NULL;
1676 unsigned long old_tail;
1677
1678 spin_lock(&journal->j_state_lock);
1679
1680 /* Force everything buffered to the log... */
1681 if (journal->j_running_transaction) {
1682 transaction = journal->j_running_transaction;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001683 __jbd2_log_start_commit(journal, transaction->t_tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001684 } else if (journal->j_committing_transaction)
1685 transaction = journal->j_committing_transaction;
1686
1687 /* Wait for the log commit to complete... */
1688 if (transaction) {
1689 tid_t tid = transaction->t_tid;
1690
1691 spin_unlock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001692 jbd2_log_wait_commit(journal, tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001693 } else {
1694 spin_unlock(&journal->j_state_lock);
1695 }
1696
1697 /* ...and flush everything in the log out to disk. */
1698 spin_lock(&journal->j_list_lock);
1699 while (!err && journal->j_checkpoint_transactions != NULL) {
1700 spin_unlock(&journal->j_list_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001701 err = jbd2_log_do_checkpoint(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001702 spin_lock(&journal->j_list_lock);
1703 }
1704 spin_unlock(&journal->j_list_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001705 jbd2_cleanup_journal_tail(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001706
1707 /* Finally, mark the journal as really needing no recovery.
1708 * This sets s_start==0 in the underlying superblock, which is
1709 * the magic code for a fully-recovered superblock. Any future
1710 * commits of data to the journal will restore the current
1711 * s_start value. */
1712 spin_lock(&journal->j_state_lock);
1713 old_tail = journal->j_tail;
1714 journal->j_tail = 0;
1715 spin_unlock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001716 jbd2_journal_update_superblock(journal, 1);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001717 spin_lock(&journal->j_state_lock);
1718 journal->j_tail = old_tail;
1719
1720 J_ASSERT(!journal->j_running_transaction);
1721 J_ASSERT(!journal->j_committing_transaction);
1722 J_ASSERT(!journal->j_checkpoint_transactions);
1723 J_ASSERT(journal->j_head == journal->j_tail);
1724 J_ASSERT(journal->j_tail_sequence == journal->j_transaction_sequence);
1725 spin_unlock(&journal->j_state_lock);
1726 return err;
1727}
1728
1729/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001730 * int jbd2_journal_wipe() - Wipe journal contents
Dave Kleikamp470decc2006-10-11 01:20:57 -07001731 * @journal: Journal to act on.
1732 * @write: flag (see below)
1733 *
1734 * Wipe out all of the contents of a journal, safely. This will produce
1735 * a warning if the journal contains any valid recovery information.
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001736 * Must be called between journal_init_*() and jbd2_journal_load().
Dave Kleikamp470decc2006-10-11 01:20:57 -07001737 *
1738 * If 'write' is non-zero, then we wipe out the journal on disk; otherwise
1739 * we merely suppress recovery.
1740 */
1741
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001742int jbd2_journal_wipe(journal_t *journal, int write)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001743{
1744 journal_superblock_t *sb;
1745 int err = 0;
1746
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001747 J_ASSERT (!(journal->j_flags & JBD2_LOADED));
Dave Kleikamp470decc2006-10-11 01:20:57 -07001748
1749 err = load_superblock(journal);
1750 if (err)
1751 return err;
1752
1753 sb = journal->j_superblock;
1754
1755 if (!journal->j_tail)
1756 goto no_recovery;
1757
1758 printk (KERN_WARNING "JBD: %s recovery information on journal\n",
1759 write ? "Clearing" : "Ignoring");
1760
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001761 err = jbd2_journal_skip_recovery(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001762 if (write)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001763 jbd2_journal_update_superblock(journal, 1);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001764
1765 no_recovery:
1766 return err;
1767}
1768
1769/*
1770 * journal_dev_name: format a character string to describe on what
1771 * device this journal is present.
1772 */
1773
1774static const char *journal_dev_name(journal_t *journal, char *buffer)
1775{
1776 struct block_device *bdev;
1777
1778 if (journal->j_inode)
1779 bdev = journal->j_inode->i_sb->s_bdev;
1780 else
1781 bdev = journal->j_dev;
1782
1783 return bdevname(bdev, buffer);
1784}
1785
1786/*
1787 * Journal abort has very specific semantics, which we describe
1788 * for journal abort.
1789 *
1790 * Two internal function, which provide abort to te jbd layer
1791 * itself are here.
1792 */
1793
1794/*
1795 * Quick version for internal journal use (doesn't lock the journal).
1796 * Aborts hard --- we mark the abort as occurred, but do _nothing_ else,
1797 * and don't attempt to make any other journal updates.
1798 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001799void __jbd2_journal_abort_hard(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001800{
1801 transaction_t *transaction;
1802 char b[BDEVNAME_SIZE];
1803
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001804 if (journal->j_flags & JBD2_ABORT)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001805 return;
1806
1807 printk(KERN_ERR "Aborting journal on device %s.\n",
1808 journal_dev_name(journal, b));
1809
1810 spin_lock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001811 journal->j_flags |= JBD2_ABORT;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001812 transaction = journal->j_running_transaction;
1813 if (transaction)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001814 __jbd2_log_start_commit(journal, transaction->t_tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001815 spin_unlock(&journal->j_state_lock);
1816}
1817
1818/* Soft abort: record the abort error status in the journal superblock,
1819 * but don't do any other IO. */
1820static void __journal_abort_soft (journal_t *journal, int errno)
1821{
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001822 if (journal->j_flags & JBD2_ABORT)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001823 return;
1824
1825 if (!journal->j_errno)
1826 journal->j_errno = errno;
1827
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001828 __jbd2_journal_abort_hard(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001829
1830 if (errno)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001831 jbd2_journal_update_superblock(journal, 1);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001832}
1833
1834/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001835 * void jbd2_journal_abort () - Shutdown the journal immediately.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001836 * @journal: the journal to shutdown.
1837 * @errno: an error number to record in the journal indicating
1838 * the reason for the shutdown.
1839 *
1840 * Perform a complete, immediate shutdown of the ENTIRE
1841 * journal (not of a single transaction). This operation cannot be
1842 * undone without closing and reopening the journal.
1843 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001844 * The jbd2_journal_abort function is intended to support higher level error
Dave Kleikamp470decc2006-10-11 01:20:57 -07001845 * recovery mechanisms such as the ext2/ext3 remount-readonly error
1846 * mode.
1847 *
1848 * Journal abort has very specific semantics. Any existing dirty,
1849 * unjournaled buffers in the main filesystem will still be written to
1850 * disk by bdflush, but the journaling mechanism will be suspended
1851 * immediately and no further transaction commits will be honoured.
1852 *
1853 * Any dirty, journaled buffers will be written back to disk without
1854 * hitting the journal. Atomicity cannot be guaranteed on an aborted
1855 * filesystem, but we _do_ attempt to leave as much data as possible
1856 * behind for fsck to use for cleanup.
1857 *
1858 * Any attempt to get a new transaction handle on a journal which is in
1859 * ABORT state will just result in an -EROFS error return. A
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001860 * jbd2_journal_stop on an existing handle will return -EIO if we have
Dave Kleikamp470decc2006-10-11 01:20:57 -07001861 * entered abort state during the update.
1862 *
1863 * Recursive transactions are not disturbed by journal abort until the
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001864 * final jbd2_journal_stop, which will receive the -EIO error.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001865 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001866 * Finally, the jbd2_journal_abort call allows the caller to supply an errno
Dave Kleikamp470decc2006-10-11 01:20:57 -07001867 * which will be recorded (if possible) in the journal superblock. This
1868 * allows a client to record failure conditions in the middle of a
1869 * transaction without having to complete the transaction to record the
1870 * failure to disk. ext3_error, for example, now uses this
1871 * functionality.
1872 *
1873 * Errors which originate from within the journaling layer will NOT
1874 * supply an errno; a null errno implies that absolutely no further
1875 * writes are done to the journal (unless there are any already in
1876 * progress).
1877 *
1878 */
1879
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001880void jbd2_journal_abort(journal_t *journal, int errno)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001881{
1882 __journal_abort_soft(journal, errno);
1883}
1884
1885/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001886 * int jbd2_journal_errno () - returns the journal's error state.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001887 * @journal: journal to examine.
1888 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001889 * This is the errno numbet set with jbd2_journal_abort(), the last
Dave Kleikamp470decc2006-10-11 01:20:57 -07001890 * time the journal was mounted - if the journal was stopped
1891 * without calling abort this will be 0.
1892 *
1893 * If the journal has been aborted on this mount time -EROFS will
1894 * be returned.
1895 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001896int jbd2_journal_errno(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001897{
1898 int err;
1899
1900 spin_lock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001901 if (journal->j_flags & JBD2_ABORT)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001902 err = -EROFS;
1903 else
1904 err = journal->j_errno;
1905 spin_unlock(&journal->j_state_lock);
1906 return err;
1907}
1908
1909/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001910 * int jbd2_journal_clear_err () - clears the journal's error state
Dave Kleikamp470decc2006-10-11 01:20:57 -07001911 * @journal: journal to act on.
1912 *
1913 * An error must be cleared or Acked to take a FS out of readonly
1914 * mode.
1915 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001916int jbd2_journal_clear_err(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001917{
1918 int err = 0;
1919
1920 spin_lock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001921 if (journal->j_flags & JBD2_ABORT)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001922 err = -EROFS;
1923 else
1924 journal->j_errno = 0;
1925 spin_unlock(&journal->j_state_lock);
1926 return err;
1927}
1928
1929/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001930 * void jbd2_journal_ack_err() - Ack journal err.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001931 * @journal: journal to act on.
1932 *
1933 * An error must be cleared or Acked to take a FS out of readonly
1934 * mode.
1935 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001936void jbd2_journal_ack_err(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001937{
1938 spin_lock(&journal->j_state_lock);
1939 if (journal->j_errno)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001940 journal->j_flags |= JBD2_ACK_ERR;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001941 spin_unlock(&journal->j_state_lock);
1942}
1943
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001944int jbd2_journal_blocks_per_page(struct inode *inode)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001945{
1946 return 1 << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
1947}
1948
1949/*
Zach Brownb517bea2006-10-11 01:21:08 -07001950 * helper functions to deal with 32 or 64bit block numbers.
1951 */
1952size_t journal_tag_bytes(journal_t *journal)
1953{
1954 if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT))
Mingming Caocd02ff02007-10-16 18:38:25 -04001955 return JBD2_TAG_SIZE64;
Zach Brownb517bea2006-10-11 01:21:08 -07001956 else
Mingming Caocd02ff02007-10-16 18:38:25 -04001957 return JBD2_TAG_SIZE32;
Zach Brownb517bea2006-10-11 01:21:08 -07001958}
1959
1960/*
Dave Kleikamp470decc2006-10-11 01:20:57 -07001961 * Journal_head storage management
1962 */
Christoph Lametere18b8902006-12-06 20:33:20 -08001963static struct kmem_cache *jbd2_journal_head_cache;
Jose R. Santose23291b2007-07-18 08:57:06 -04001964#ifdef CONFIG_JBD2_DEBUG
Dave Kleikamp470decc2006-10-11 01:20:57 -07001965static atomic_t nr_journal_heads = ATOMIC_INIT(0);
1966#endif
1967
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001968static int journal_init_jbd2_journal_head_cache(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001969{
1970 int retval;
1971
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001972 J_ASSERT(jbd2_journal_head_cache == 0);
Johann Lombardia920e942006-10-11 01:21:00 -07001973 jbd2_journal_head_cache = kmem_cache_create("jbd2_journal_head",
Dave Kleikamp470decc2006-10-11 01:20:57 -07001974 sizeof(struct journal_head),
1975 0, /* offset */
Mingming Cao77160952008-01-28 23:58:27 -05001976 SLAB_TEMPORARY, /* flags */
Paul Mundt20c2df82007-07-20 10:11:58 +09001977 NULL); /* ctor */
Dave Kleikamp470decc2006-10-11 01:20:57 -07001978 retval = 0;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001979 if (jbd2_journal_head_cache == 0) {
Dave Kleikamp470decc2006-10-11 01:20:57 -07001980 retval = -ENOMEM;
1981 printk(KERN_EMERG "JBD: no memory for journal_head cache\n");
1982 }
1983 return retval;
1984}
1985
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001986static void jbd2_journal_destroy_jbd2_journal_head_cache(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001987{
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001988 J_ASSERT(jbd2_journal_head_cache != NULL);
1989 kmem_cache_destroy(jbd2_journal_head_cache);
1990 jbd2_journal_head_cache = NULL;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001991}
1992
1993/*
1994 * journal_head splicing and dicing
1995 */
1996static struct journal_head *journal_alloc_journal_head(void)
1997{
1998 struct journal_head *ret;
1999 static unsigned long last_warning;
2000
Jose R. Santose23291b2007-07-18 08:57:06 -04002001#ifdef CONFIG_JBD2_DEBUG
Dave Kleikamp470decc2006-10-11 01:20:57 -07002002 atomic_inc(&nr_journal_heads);
2003#endif
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002004 ret = kmem_cache_alloc(jbd2_journal_head_cache, GFP_NOFS);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002005 if (ret == 0) {
2006 jbd_debug(1, "out of memory for journal_head\n");
2007 if (time_after(jiffies, last_warning + 5*HZ)) {
2008 printk(KERN_NOTICE "ENOMEM in %s, retrying.\n",
2009 __FUNCTION__);
2010 last_warning = jiffies;
2011 }
2012 while (ret == 0) {
2013 yield();
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002014 ret = kmem_cache_alloc(jbd2_journal_head_cache, GFP_NOFS);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002015 }
2016 }
2017 return ret;
2018}
2019
2020static void journal_free_journal_head(struct journal_head *jh)
2021{
Jose R. Santose23291b2007-07-18 08:57:06 -04002022#ifdef CONFIG_JBD2_DEBUG
Dave Kleikamp470decc2006-10-11 01:20:57 -07002023 atomic_dec(&nr_journal_heads);
Mingming Caocd02ff02007-10-16 18:38:25 -04002024 memset(jh, JBD2_POISON_FREE, sizeof(*jh));
Dave Kleikamp470decc2006-10-11 01:20:57 -07002025#endif
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002026 kmem_cache_free(jbd2_journal_head_cache, jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002027}
2028
2029/*
2030 * A journal_head is attached to a buffer_head whenever JBD has an
2031 * interest in the buffer.
2032 *
2033 * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit
2034 * is set. This bit is tested in core kernel code where we need to take
2035 * JBD-specific actions. Testing the zeroness of ->b_private is not reliable
2036 * there.
2037 *
2038 * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one.
2039 *
2040 * When a buffer has its BH_JBD bit set it is immune from being released by
2041 * core kernel code, mainly via ->b_count.
2042 *
2043 * A journal_head may be detached from its buffer_head when the journal_head's
2044 * b_transaction, b_cp_transaction and b_next_transaction pointers are NULL.
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002045 * Various places in JBD call jbd2_journal_remove_journal_head() to indicate that the
Dave Kleikamp470decc2006-10-11 01:20:57 -07002046 * journal_head can be dropped if needed.
2047 *
2048 * Various places in the kernel want to attach a journal_head to a buffer_head
2049 * _before_ attaching the journal_head to a transaction. To protect the
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002050 * journal_head in this situation, jbd2_journal_add_journal_head elevates the
Dave Kleikamp470decc2006-10-11 01:20:57 -07002051 * journal_head's b_jcount refcount by one. The caller must call
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002052 * jbd2_journal_put_journal_head() to undo this.
Dave Kleikamp470decc2006-10-11 01:20:57 -07002053 *
2054 * So the typical usage would be:
2055 *
2056 * (Attach a journal_head if needed. Increments b_jcount)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002057 * struct journal_head *jh = jbd2_journal_add_journal_head(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002058 * ...
2059 * jh->b_transaction = xxx;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002060 * jbd2_journal_put_journal_head(jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002061 *
2062 * Now, the journal_head's b_jcount is zero, but it is safe from being released
2063 * because it has a non-zero b_transaction.
2064 */
2065
2066/*
2067 * Give a buffer_head a journal_head.
2068 *
2069 * Doesn't need the journal lock.
2070 * May sleep.
2071 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002072struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07002073{
2074 struct journal_head *jh;
2075 struct journal_head *new_jh = NULL;
2076
2077repeat:
2078 if (!buffer_jbd(bh)) {
2079 new_jh = journal_alloc_journal_head();
2080 memset(new_jh, 0, sizeof(*new_jh));
2081 }
2082
2083 jbd_lock_bh_journal_head(bh);
2084 if (buffer_jbd(bh)) {
2085 jh = bh2jh(bh);
2086 } else {
2087 J_ASSERT_BH(bh,
2088 (atomic_read(&bh->b_count) > 0) ||
2089 (bh->b_page && bh->b_page->mapping));
2090
2091 if (!new_jh) {
2092 jbd_unlock_bh_journal_head(bh);
2093 goto repeat;
2094 }
2095
2096 jh = new_jh;
2097 new_jh = NULL; /* We consumed it */
2098 set_buffer_jbd(bh);
2099 bh->b_private = jh;
2100 jh->b_bh = bh;
2101 get_bh(bh);
2102 BUFFER_TRACE(bh, "added journal_head");
2103 }
2104 jh->b_jcount++;
2105 jbd_unlock_bh_journal_head(bh);
2106 if (new_jh)
2107 journal_free_journal_head(new_jh);
2108 return bh->b_private;
2109}
2110
2111/*
2112 * Grab a ref against this buffer_head's journal_head. If it ended up not
2113 * having a journal_head, return NULL
2114 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002115struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07002116{
2117 struct journal_head *jh = NULL;
2118
2119 jbd_lock_bh_journal_head(bh);
2120 if (buffer_jbd(bh)) {
2121 jh = bh2jh(bh);
2122 jh->b_jcount++;
2123 }
2124 jbd_unlock_bh_journal_head(bh);
2125 return jh;
2126}
2127
2128static void __journal_remove_journal_head(struct buffer_head *bh)
2129{
2130 struct journal_head *jh = bh2jh(bh);
2131
2132 J_ASSERT_JH(jh, jh->b_jcount >= 0);
2133
2134 get_bh(bh);
2135 if (jh->b_jcount == 0) {
2136 if (jh->b_transaction == NULL &&
2137 jh->b_next_transaction == NULL &&
2138 jh->b_cp_transaction == NULL) {
2139 J_ASSERT_JH(jh, jh->b_jlist == BJ_None);
2140 J_ASSERT_BH(bh, buffer_jbd(bh));
2141 J_ASSERT_BH(bh, jh2bh(jh) == bh);
2142 BUFFER_TRACE(bh, "remove journal_head");
2143 if (jh->b_frozen_data) {
2144 printk(KERN_WARNING "%s: freeing "
2145 "b_frozen_data\n",
2146 __FUNCTION__);
Mingming Caoaf1e76d2007-10-16 18:38:25 -04002147 jbd2_free(jh->b_frozen_data, bh->b_size);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002148 }
2149 if (jh->b_committed_data) {
2150 printk(KERN_WARNING "%s: freeing "
2151 "b_committed_data\n",
2152 __FUNCTION__);
Mingming Caoaf1e76d2007-10-16 18:38:25 -04002153 jbd2_free(jh->b_committed_data, bh->b_size);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002154 }
2155 bh->b_private = NULL;
2156 jh->b_bh = NULL; /* debug, really */
2157 clear_buffer_jbd(bh);
2158 __brelse(bh);
2159 journal_free_journal_head(jh);
2160 } else {
2161 BUFFER_TRACE(bh, "journal_head was locked");
2162 }
2163 }
2164}
2165
2166/*
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002167 * jbd2_journal_remove_journal_head(): if the buffer isn't attached to a transaction
Dave Kleikamp470decc2006-10-11 01:20:57 -07002168 * and has a zero b_jcount then remove and release its journal_head. If we did
2169 * see that the buffer is not used by any transaction we also "logically"
2170 * decrement ->b_count.
2171 *
2172 * We in fact take an additional increment on ->b_count as a convenience,
2173 * because the caller usually wants to do additional things with the bh
2174 * after calling here.
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002175 * The caller of jbd2_journal_remove_journal_head() *must* run __brelse(bh) at some
Dave Kleikamp470decc2006-10-11 01:20:57 -07002176 * time. Once the caller has run __brelse(), the buffer is eligible for
2177 * reaping by try_to_free_buffers().
2178 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002179void jbd2_journal_remove_journal_head(struct buffer_head *bh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07002180{
2181 jbd_lock_bh_journal_head(bh);
2182 __journal_remove_journal_head(bh);
2183 jbd_unlock_bh_journal_head(bh);
2184}
2185
2186/*
2187 * Drop a reference on the passed journal_head. If it fell to zero then try to
2188 * release the journal_head from the buffer_head.
2189 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002190void jbd2_journal_put_journal_head(struct journal_head *jh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07002191{
2192 struct buffer_head *bh = jh2bh(jh);
2193
2194 jbd_lock_bh_journal_head(bh);
2195 J_ASSERT_JH(jh, jh->b_jcount > 0);
2196 --jh->b_jcount;
2197 if (!jh->b_jcount && !jh->b_transaction) {
2198 __journal_remove_journal_head(bh);
2199 __brelse(bh);
2200 }
2201 jbd_unlock_bh_journal_head(bh);
2202}
2203
2204/*
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002205 * debugfs tunables
Dave Kleikamp470decc2006-10-11 01:20:57 -07002206 */
Jose R. Santos6f38c742007-10-16 18:38:25 -04002207#ifdef CONFIG_JBD2_DEBUG
2208u8 jbd2_journal_enable_debug __read_mostly;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002209EXPORT_SYMBOL(jbd2_journal_enable_debug);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002210
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002211#define JBD2_DEBUG_NAME "jbd2-debug"
Dave Kleikamp470decc2006-10-11 01:20:57 -07002212
Jose R. Santos6f38c742007-10-16 18:38:25 -04002213static struct dentry *jbd2_debugfs_dir;
2214static struct dentry *jbd2_debug;
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002215
2216static void __init jbd2_create_debugfs_entry(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07002217{
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002218 jbd2_debugfs_dir = debugfs_create_dir("jbd2", NULL);
2219 if (jbd2_debugfs_dir)
2220 jbd2_debug = debugfs_create_u8(JBD2_DEBUG_NAME, S_IRUGO,
2221 jbd2_debugfs_dir,
2222 &jbd2_journal_enable_debug);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002223}
2224
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002225static void __exit jbd2_remove_debugfs_entry(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07002226{
Jose R. Santos6f38c742007-10-16 18:38:25 -04002227 debugfs_remove(jbd2_debug);
2228 debugfs_remove(jbd2_debugfs_dir);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002229}
2230
2231#else
2232
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002233static void __init jbd2_create_debugfs_entry(void)
2234{
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002235}
2236
2237static void __exit jbd2_remove_debugfs_entry(void)
2238{
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002239}
Dave Kleikamp470decc2006-10-11 01:20:57 -07002240
2241#endif
2242
Johann Lombardi8e85fb32008-01-28 23:58:27 -05002243#ifdef CONFIG_PROC_FS
2244
2245#define JBD2_STATS_PROC_NAME "fs/jbd2"
2246
2247static void __init jbd2_create_jbd_stats_proc_entry(void)
2248{
2249 proc_jbd2_stats = proc_mkdir(JBD2_STATS_PROC_NAME, NULL);
2250}
2251
2252static void __exit jbd2_remove_jbd_stats_proc_entry(void)
2253{
2254 if (proc_jbd2_stats)
2255 remove_proc_entry(JBD2_STATS_PROC_NAME, NULL);
2256}
2257
2258#else
2259
2260#define jbd2_create_jbd_stats_proc_entry() do {} while (0)
2261#define jbd2_remove_jbd_stats_proc_entry() do {} while (0)
2262
2263#endif
2264
Christoph Lametere18b8902006-12-06 20:33:20 -08002265struct kmem_cache *jbd2_handle_cache;
Dave Kleikamp470decc2006-10-11 01:20:57 -07002266
2267static int __init journal_init_handle_cache(void)
2268{
Johann Lombardia920e942006-10-11 01:21:00 -07002269 jbd2_handle_cache = kmem_cache_create("jbd2_journal_handle",
Dave Kleikamp470decc2006-10-11 01:20:57 -07002270 sizeof(handle_t),
2271 0, /* offset */
Mingming Cao77160952008-01-28 23:58:27 -05002272 SLAB_TEMPORARY, /* flags */
Paul Mundt20c2df82007-07-20 10:11:58 +09002273 NULL); /* ctor */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002274 if (jbd2_handle_cache == NULL) {
Dave Kleikamp470decc2006-10-11 01:20:57 -07002275 printk(KERN_EMERG "JBD: failed to create handle cache\n");
2276 return -ENOMEM;
2277 }
2278 return 0;
2279}
2280
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002281static void jbd2_journal_destroy_handle_cache(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07002282{
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002283 if (jbd2_handle_cache)
2284 kmem_cache_destroy(jbd2_handle_cache);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002285}
2286
2287/*
2288 * Module startup and shutdown
2289 */
2290
2291static int __init journal_init_caches(void)
2292{
2293 int ret;
2294
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002295 ret = jbd2_journal_init_revoke_caches();
Dave Kleikamp470decc2006-10-11 01:20:57 -07002296 if (ret == 0)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002297 ret = journal_init_jbd2_journal_head_cache();
Dave Kleikamp470decc2006-10-11 01:20:57 -07002298 if (ret == 0)
2299 ret = journal_init_handle_cache();
2300 return ret;
2301}
2302
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002303static void jbd2_journal_destroy_caches(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07002304{
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002305 jbd2_journal_destroy_revoke_caches();
2306 jbd2_journal_destroy_jbd2_journal_head_cache();
2307 jbd2_journal_destroy_handle_cache();
Dave Kleikamp470decc2006-10-11 01:20:57 -07002308}
2309
2310static int __init journal_init(void)
2311{
2312 int ret;
2313
2314 BUILD_BUG_ON(sizeof(struct journal_superblock_s) != 1024);
2315
2316 ret = journal_init_caches();
2317 if (ret != 0)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002318 jbd2_journal_destroy_caches();
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002319 jbd2_create_debugfs_entry();
Johann Lombardi8e85fb32008-01-28 23:58:27 -05002320 jbd2_create_jbd_stats_proc_entry();
Dave Kleikamp470decc2006-10-11 01:20:57 -07002321 return ret;
2322}
2323
2324static void __exit journal_exit(void)
2325{
Jose R. Santose23291b2007-07-18 08:57:06 -04002326#ifdef CONFIG_JBD2_DEBUG
Dave Kleikamp470decc2006-10-11 01:20:57 -07002327 int n = atomic_read(&nr_journal_heads);
2328 if (n)
2329 printk(KERN_EMERG "JBD: leaked %d journal_heads!\n", n);
2330#endif
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002331 jbd2_remove_debugfs_entry();
Johann Lombardi8e85fb32008-01-28 23:58:27 -05002332 jbd2_remove_jbd_stats_proc_entry();
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002333 jbd2_journal_destroy_caches();
Dave Kleikamp470decc2006-10-11 01:20:57 -07002334}
2335
2336MODULE_LICENSE("GPL");
2337module_init(journal_init);
2338module_exit(journal_exit);
2339