blob: 2e24567c4a797ddf5c18c481bf53eef8bc01ad50 [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
Al Viro1076d172008-03-29 03:07:18 +0000222 wait_event(journal->j_wait_done_commit, journal->j_task != NULL);
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);
Al Viro1076d172008-03-29 03:07:18 +0000234 wait_event(journal->j_wait_done_commit, journal->j_task == NULL);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700235 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",
Harvey Harrison329d2912008-04-17 10:38:59 -0400537 __func__, journal->j_commit_request, tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700538 }
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",
Harvey Harrison329d2912008-04-17 10:38:59 -0400602 __func__,
Dave Kleikamp470decc2006-10-11 01:20:57 -0700603 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
Jean Delvaref36f21e2008-05-12 14:02:33 -0700904 bdevname(journal->j_dev, name);
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500905 journal->j_proc_entry = proc_mkdir(name, proc_jbd2_stats);
906 if (journal->j_proc_entry) {
Denis V. Lunev79da3662008-04-29 01:02:11 -0700907 proc_create_data("history", S_IRUGO, journal->j_proc_entry,
908 &jbd2_seq_history_fops, journal);
909 proc_create_data("info", S_IRUGO, journal->j_proc_entry,
910 &jbd2_seq_info_fops, journal);
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500911 }
912}
913
914static void jbd2_stats_proc_exit(journal_t *journal)
915{
916 char name[BDEVNAME_SIZE];
917
Jean Delvaref36f21e2008-05-12 14:02:33 -0700918 bdevname(journal->j_dev, name);
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500919 remove_proc_entry("info", journal->j_proc_entry);
920 remove_proc_entry("history", journal->j_proc_entry);
921 remove_proc_entry(name, proc_jbd2_stats);
922}
923
924static void journal_init_stats(journal_t *journal)
925{
926 int size;
927
928 if (!proc_jbd2_stats)
929 return;
930
931 journal->j_history_max = 100;
932 size = sizeof(struct transaction_stats_s) * journal->j_history_max;
933 journal->j_history = kzalloc(size, GFP_KERNEL);
934 if (!journal->j_history) {
935 journal->j_history_max = 0;
936 return;
937 }
938 spin_lock_init(&journal->j_history_lock);
939}
940
Dave Kleikamp470decc2006-10-11 01:20:57 -0700941/*
942 * Management for journal control blocks: functions to create and
943 * destroy journal_t structures, and to initialise and read existing
944 * journal blocks from disk. */
945
946/* First: create and setup a journal_t object in memory. We initialise
947 * very few fields yet: that has to wait until we have created the
948 * journal structures from from scratch, or loaded them from disk. */
949
950static journal_t * journal_init_common (void)
951{
952 journal_t *journal;
953 int err;
954
Mingming Caod802ffa2007-10-16 18:38:25 -0400955 journal = kzalloc(sizeof(*journal), GFP_KERNEL|__GFP_NOFAIL);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700956 if (!journal)
957 goto fail;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700958
959 init_waitqueue_head(&journal->j_wait_transaction_locked);
960 init_waitqueue_head(&journal->j_wait_logspace);
961 init_waitqueue_head(&journal->j_wait_done_commit);
962 init_waitqueue_head(&journal->j_wait_checkpoint);
963 init_waitqueue_head(&journal->j_wait_commit);
964 init_waitqueue_head(&journal->j_wait_updates);
965 mutex_init(&journal->j_barrier);
966 mutex_init(&journal->j_checkpoint_mutex);
967 spin_lock_init(&journal->j_revoke_lock);
968 spin_lock_init(&journal->j_list_lock);
969 spin_lock_init(&journal->j_state_lock);
970
Mingming Caocd02ff02007-10-16 18:38:25 -0400971 journal->j_commit_interval = (HZ * JBD2_DEFAULT_MAX_COMMIT_AGE);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700972
973 /* The journal is marked for error until we succeed with recovery! */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700974 journal->j_flags = JBD2_ABORT;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700975
976 /* Set up a default-sized revoke table for the new mount. */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700977 err = jbd2_journal_init_revoke(journal, JOURNAL_REVOKE_DEFAULT_HASH);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700978 if (err) {
979 kfree(journal);
980 goto fail;
981 }
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500982
983 journal_init_stats(journal);
984
Dave Kleikamp470decc2006-10-11 01:20:57 -0700985 return journal;
986fail:
987 return NULL;
988}
989
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700990/* jbd2_journal_init_dev and jbd2_journal_init_inode:
Dave Kleikamp470decc2006-10-11 01:20:57 -0700991 *
992 * Create a journal structure assigned some fixed set of disk blocks to
993 * the journal. We don't actually touch those disk blocks yet, but we
994 * need to set up all of the mapping information to tell the journaling
995 * system where the journal blocks are.
996 *
997 */
998
999/**
Randy Dunlap5648ba52008-04-17 10:38:59 -04001000 * journal_t * jbd2_journal_init_dev() - creates and initialises a journal structure
Dave Kleikamp470decc2006-10-11 01:20:57 -07001001 * @bdev: Block device on which to create the journal
1002 * @fs_dev: Device which hold journalled filesystem for this journal.
1003 * @start: Block nr Start of journal.
1004 * @len: Length of the journal in blocks.
1005 * @blocksize: blocksize of journalling device
Randy Dunlap5648ba52008-04-17 10:38:59 -04001006 *
1007 * Returns: a newly created journal_t *
Dave Kleikamp470decc2006-10-11 01:20:57 -07001008 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001009 * jbd2_journal_init_dev creates a journal which maps a fixed contiguous
Dave Kleikamp470decc2006-10-11 01:20:57 -07001010 * range of blocks on an arbitrary block device.
1011 *
1012 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001013journal_t * jbd2_journal_init_dev(struct block_device *bdev,
Dave Kleikamp470decc2006-10-11 01:20:57 -07001014 struct block_device *fs_dev,
Mingming Cao18eba7a2006-10-11 01:21:13 -07001015 unsigned long long start, int len, int blocksize)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001016{
1017 journal_t *journal = journal_init_common();
1018 struct buffer_head *bh;
1019 int n;
1020
1021 if (!journal)
1022 return NULL;
1023
1024 /* journal descriptor can store up to n blocks -bzzz */
1025 journal->j_blocksize = blocksize;
1026 n = journal->j_blocksize / sizeof(journal_block_tag_t);
1027 journal->j_wbufsize = n;
1028 journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
1029 if (!journal->j_wbuf) {
1030 printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n",
Harvey Harrison329d2912008-04-17 10:38:59 -04001031 __func__);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001032 kfree(journal);
1033 journal = NULL;
Dave Kleikamp5eb30792006-10-17 00:09:35 -07001034 goto out;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001035 }
1036 journal->j_dev = bdev;
1037 journal->j_fs_dev = fs_dev;
1038 journal->j_blk_offset = start;
1039 journal->j_maxlen = len;
Johann Lombardi8e85fb32008-01-28 23:58:27 -05001040 jbd2_stats_proc_init(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001041
1042 bh = __getblk(journal->j_dev, start, journal->j_blocksize);
1043 J_ASSERT(bh != NULL);
1044 journal->j_sb_buffer = bh;
1045 journal->j_superblock = (journal_superblock_t *)bh->b_data;
Dave Kleikamp5eb30792006-10-17 00:09:35 -07001046out:
Dave Kleikamp470decc2006-10-11 01:20:57 -07001047 return journal;
1048}
1049
1050/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001051 * journal_t * jbd2_journal_init_inode () - creates a journal which maps to a inode.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001052 * @inode: An inode to create the journal in
1053 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001054 * jbd2_journal_init_inode creates a journal which maps an on-disk inode as
Dave Kleikamp470decc2006-10-11 01:20:57 -07001055 * the journal. The inode must exist already, must support bmap() and
1056 * must have all data blocks preallocated.
1057 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001058journal_t * jbd2_journal_init_inode (struct inode *inode)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001059{
1060 struct buffer_head *bh;
1061 journal_t *journal = journal_init_common();
1062 int err;
1063 int n;
Mingming Cao18eba7a2006-10-11 01:21:13 -07001064 unsigned long long blocknr;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001065
1066 if (!journal)
1067 return NULL;
1068
1069 journal->j_dev = journal->j_fs_dev = inode->i_sb->s_bdev;
1070 journal->j_inode = inode;
1071 jbd_debug(1,
1072 "journal %p: inode %s/%ld, size %Ld, bits %d, blksize %ld\n",
1073 journal, inode->i_sb->s_id, inode->i_ino,
1074 (long long) inode->i_size,
1075 inode->i_sb->s_blocksize_bits, inode->i_sb->s_blocksize);
1076
1077 journal->j_maxlen = inode->i_size >> inode->i_sb->s_blocksize_bits;
1078 journal->j_blocksize = inode->i_sb->s_blocksize;
Johann Lombardi8e85fb32008-01-28 23:58:27 -05001079 jbd2_stats_proc_init(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001080
1081 /* journal descriptor can store up to n blocks -bzzz */
1082 n = journal->j_blocksize / sizeof(journal_block_tag_t);
1083 journal->j_wbufsize = n;
1084 journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
1085 if (!journal->j_wbuf) {
1086 printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n",
Harvey Harrison329d2912008-04-17 10:38:59 -04001087 __func__);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001088 kfree(journal);
1089 return NULL;
1090 }
1091
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001092 err = jbd2_journal_bmap(journal, 0, &blocknr);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001093 /* If that failed, give up */
1094 if (err) {
1095 printk(KERN_ERR "%s: Cannnot locate journal superblock\n",
Harvey Harrison329d2912008-04-17 10:38:59 -04001096 __func__);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001097 kfree(journal);
1098 return NULL;
1099 }
1100
1101 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
1102 J_ASSERT(bh != NULL);
1103 journal->j_sb_buffer = bh;
1104 journal->j_superblock = (journal_superblock_t *)bh->b_data;
1105
1106 return journal;
1107}
1108
1109/*
1110 * If the journal init or create aborts, we need to mark the journal
1111 * superblock as being NULL to prevent the journal destroy from writing
1112 * back a bogus superblock.
1113 */
1114static void journal_fail_superblock (journal_t *journal)
1115{
1116 struct buffer_head *bh = journal->j_sb_buffer;
1117 brelse(bh);
1118 journal->j_sb_buffer = NULL;
1119}
1120
1121/*
1122 * Given a journal_t structure, initialise the various fields for
1123 * startup of a new journaling session. We use this both when creating
1124 * a journal, and after recovering an old journal to reset it for
1125 * subsequent use.
1126 */
1127
1128static int journal_reset(journal_t *journal)
1129{
1130 journal_superblock_t *sb = journal->j_superblock;
Mingming Cao18eba7a2006-10-11 01:21:13 -07001131 unsigned long long first, last;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001132
1133 first = be32_to_cpu(sb->s_first);
1134 last = be32_to_cpu(sb->s_maxlen);
1135
1136 journal->j_first = first;
1137 journal->j_last = last;
1138
1139 journal->j_head = first;
1140 journal->j_tail = first;
1141 journal->j_free = last - first;
1142
1143 journal->j_tail_sequence = journal->j_transaction_sequence;
1144 journal->j_commit_sequence = journal->j_transaction_sequence - 1;
1145 journal->j_commit_request = journal->j_commit_sequence;
1146
1147 journal->j_max_transaction_buffers = journal->j_maxlen / 4;
1148
1149 /* Add the dynamic fields and write it to disk. */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001150 jbd2_journal_update_superblock(journal, 1);
Pavel Emelianov97f06782007-05-08 00:30:42 -07001151 return jbd2_journal_start_thread(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001152}
1153
1154/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001155 * int jbd2_journal_create() - Initialise the new journal file
Dave Kleikamp470decc2006-10-11 01:20:57 -07001156 * @journal: Journal to create. This structure must have been initialised
1157 *
1158 * Given a journal_t structure which tells us which disk blocks we can
1159 * use, create a new journal superblock and initialise all of the
1160 * journal fields from scratch.
1161 **/
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001162int jbd2_journal_create(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001163{
Mingming Cao18eba7a2006-10-11 01:21:13 -07001164 unsigned long long blocknr;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001165 struct buffer_head *bh;
1166 journal_superblock_t *sb;
1167 int i, err;
1168
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001169 if (journal->j_maxlen < JBD2_MIN_JOURNAL_BLOCKS) {
Dave Kleikamp470decc2006-10-11 01:20:57 -07001170 printk (KERN_ERR "Journal length (%d blocks) too short.\n",
1171 journal->j_maxlen);
1172 journal_fail_superblock(journal);
1173 return -EINVAL;
1174 }
1175
1176 if (journal->j_inode == NULL) {
1177 /*
1178 * We don't know what block to start at!
1179 */
1180 printk(KERN_EMERG
1181 "%s: creation of journal on external device!\n",
Harvey Harrison329d2912008-04-17 10:38:59 -04001182 __func__);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001183 BUG();
1184 }
1185
1186 /* Zero out the entire journal on disk. We cannot afford to
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001187 have any blocks on disk beginning with JBD2_MAGIC_NUMBER. */
Dave Kleikamp470decc2006-10-11 01:20:57 -07001188 jbd_debug(1, "JBD: Zeroing out journal blocks...\n");
1189 for (i = 0; i < journal->j_maxlen; i++) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001190 err = jbd2_journal_bmap(journal, i, &blocknr);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001191 if (err)
1192 return err;
1193 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
1194 lock_buffer(bh);
1195 memset (bh->b_data, 0, journal->j_blocksize);
1196 BUFFER_TRACE(bh, "marking dirty");
1197 mark_buffer_dirty(bh);
1198 BUFFER_TRACE(bh, "marking uptodate");
1199 set_buffer_uptodate(bh);
1200 unlock_buffer(bh);
1201 __brelse(bh);
1202 }
1203
1204 sync_blockdev(journal->j_dev);
1205 jbd_debug(1, "JBD: journal cleared.\n");
1206
1207 /* OK, fill in the initial static fields in the new superblock */
1208 sb = journal->j_superblock;
1209
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001210 sb->s_header.h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER);
1211 sb->s_header.h_blocktype = cpu_to_be32(JBD2_SUPERBLOCK_V2);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001212
1213 sb->s_blocksize = cpu_to_be32(journal->j_blocksize);
1214 sb->s_maxlen = cpu_to_be32(journal->j_maxlen);
1215 sb->s_first = cpu_to_be32(1);
1216
1217 journal->j_transaction_sequence = 1;
1218
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001219 journal->j_flags &= ~JBD2_ABORT;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001220 journal->j_format_version = 2;
1221
1222 return journal_reset(journal);
1223}
1224
1225/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001226 * void jbd2_journal_update_superblock() - Update journal sb on disk.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001227 * @journal: The journal to update.
1228 * @wait: Set to '0' if you don't want to wait for IO completion.
1229 *
1230 * Update a journal's dynamic superblock fields and write it to disk,
1231 * optionally waiting for the IO to complete.
1232 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001233void jbd2_journal_update_superblock(journal_t *journal, int wait)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001234{
1235 journal_superblock_t *sb = journal->j_superblock;
1236 struct buffer_head *bh = journal->j_sb_buffer;
1237
1238 /*
1239 * As a special case, if the on-disk copy is already marked as needing
1240 * no recovery (s_start == 0) and there are no outstanding transactions
1241 * in the filesystem, then we can safely defer the superblock update
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001242 * until the next commit by setting JBD2_FLUSHED. This avoids
Dave Kleikamp470decc2006-10-11 01:20:57 -07001243 * attempting a write to a potential-readonly device.
1244 */
1245 if (sb->s_start == 0 && journal->j_tail_sequence ==
1246 journal->j_transaction_sequence) {
1247 jbd_debug(1,"JBD: Skipping superblock update on recovered sb "
1248 "(start %ld, seq %d, errno %d)\n",
1249 journal->j_tail, journal->j_tail_sequence,
1250 journal->j_errno);
1251 goto out;
1252 }
1253
1254 spin_lock(&journal->j_state_lock);
1255 jbd_debug(1,"JBD: updating superblock (start %ld, seq %d, errno %d)\n",
1256 journal->j_tail, journal->j_tail_sequence, journal->j_errno);
1257
1258 sb->s_sequence = cpu_to_be32(journal->j_tail_sequence);
1259 sb->s_start = cpu_to_be32(journal->j_tail);
1260 sb->s_errno = cpu_to_be32(journal->j_errno);
1261 spin_unlock(&journal->j_state_lock);
1262
1263 BUFFER_TRACE(bh, "marking dirty");
1264 mark_buffer_dirty(bh);
1265 if (wait)
1266 sync_dirty_buffer(bh);
1267 else
1268 ll_rw_block(SWRITE, 1, &bh);
1269
1270out:
1271 /* If we have just flushed the log (by marking s_start==0), then
1272 * any future commit will have to be careful to update the
1273 * superblock again to re-record the true start of the log. */
1274
1275 spin_lock(&journal->j_state_lock);
1276 if (sb->s_start)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001277 journal->j_flags &= ~JBD2_FLUSHED;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001278 else
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001279 journal->j_flags |= JBD2_FLUSHED;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001280 spin_unlock(&journal->j_state_lock);
1281}
1282
1283/*
1284 * Read the superblock for a given journal, performing initial
1285 * validation of the format.
1286 */
1287
1288static int journal_get_superblock(journal_t *journal)
1289{
1290 struct buffer_head *bh;
1291 journal_superblock_t *sb;
1292 int err = -EIO;
1293
1294 bh = journal->j_sb_buffer;
1295
1296 J_ASSERT(bh != NULL);
1297 if (!buffer_uptodate(bh)) {
1298 ll_rw_block(READ, 1, &bh);
1299 wait_on_buffer(bh);
1300 if (!buffer_uptodate(bh)) {
1301 printk (KERN_ERR
1302 "JBD: IO error reading journal superblock\n");
1303 goto out;
1304 }
1305 }
1306
1307 sb = journal->j_superblock;
1308
1309 err = -EINVAL;
1310
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001311 if (sb->s_header.h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER) ||
Dave Kleikamp470decc2006-10-11 01:20:57 -07001312 sb->s_blocksize != cpu_to_be32(journal->j_blocksize)) {
1313 printk(KERN_WARNING "JBD: no valid journal superblock found\n");
1314 goto out;
1315 }
1316
1317 switch(be32_to_cpu(sb->s_header.h_blocktype)) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001318 case JBD2_SUPERBLOCK_V1:
Dave Kleikamp470decc2006-10-11 01:20:57 -07001319 journal->j_format_version = 1;
1320 break;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001321 case JBD2_SUPERBLOCK_V2:
Dave Kleikamp470decc2006-10-11 01:20:57 -07001322 journal->j_format_version = 2;
1323 break;
1324 default:
1325 printk(KERN_WARNING "JBD: unrecognised superblock format ID\n");
1326 goto out;
1327 }
1328
1329 if (be32_to_cpu(sb->s_maxlen) < journal->j_maxlen)
1330 journal->j_maxlen = be32_to_cpu(sb->s_maxlen);
1331 else if (be32_to_cpu(sb->s_maxlen) > journal->j_maxlen) {
1332 printk (KERN_WARNING "JBD: journal file too short\n");
1333 goto out;
1334 }
1335
1336 return 0;
1337
1338out:
1339 journal_fail_superblock(journal);
1340 return err;
1341}
1342
1343/*
1344 * Load the on-disk journal superblock and read the key fields into the
1345 * journal_t.
1346 */
1347
1348static int load_superblock(journal_t *journal)
1349{
1350 int err;
1351 journal_superblock_t *sb;
1352
1353 err = journal_get_superblock(journal);
1354 if (err)
1355 return err;
1356
1357 sb = journal->j_superblock;
1358
1359 journal->j_tail_sequence = be32_to_cpu(sb->s_sequence);
1360 journal->j_tail = be32_to_cpu(sb->s_start);
1361 journal->j_first = be32_to_cpu(sb->s_first);
1362 journal->j_last = be32_to_cpu(sb->s_maxlen);
1363 journal->j_errno = be32_to_cpu(sb->s_errno);
1364
1365 return 0;
1366}
1367
1368
1369/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001370 * int jbd2_journal_load() - Read journal from disk.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001371 * @journal: Journal to act on.
1372 *
1373 * Given a journal_t structure which tells us which disk blocks contain
1374 * a journal, read the journal from disk to initialise the in-memory
1375 * structures.
1376 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001377int jbd2_journal_load(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001378{
1379 int err;
1380 journal_superblock_t *sb;
1381
1382 err = load_superblock(journal);
1383 if (err)
1384 return err;
1385
1386 sb = journal->j_superblock;
1387 /* If this is a V2 superblock, then we have to check the
1388 * features flags on it. */
1389
1390 if (journal->j_format_version >= 2) {
1391 if ((sb->s_feature_ro_compat &
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001392 ~cpu_to_be32(JBD2_KNOWN_ROCOMPAT_FEATURES)) ||
Dave Kleikamp470decc2006-10-11 01:20:57 -07001393 (sb->s_feature_incompat &
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001394 ~cpu_to_be32(JBD2_KNOWN_INCOMPAT_FEATURES))) {
Dave Kleikamp470decc2006-10-11 01:20:57 -07001395 printk (KERN_WARNING
1396 "JBD: Unrecognised features on journal\n");
1397 return -EINVAL;
1398 }
1399 }
1400
Dave Kleikamp470decc2006-10-11 01:20:57 -07001401 /* Let the recovery code check whether it needs to recover any
1402 * data from the journal. */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001403 if (jbd2_journal_recover(journal))
Dave Kleikamp470decc2006-10-11 01:20:57 -07001404 goto recovery_error;
1405
1406 /* OK, we've finished with the dynamic journal bits:
1407 * reinitialise the dynamic contents of the superblock in memory
1408 * and reset them on disk. */
1409 if (journal_reset(journal))
1410 goto recovery_error;
1411
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001412 journal->j_flags &= ~JBD2_ABORT;
1413 journal->j_flags |= JBD2_LOADED;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001414 return 0;
1415
1416recovery_error:
1417 printk (KERN_WARNING "JBD: recovery failed\n");
1418 return -EIO;
1419}
1420
1421/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001422 * void jbd2_journal_destroy() - Release a journal_t structure.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001423 * @journal: Journal to act on.
1424 *
1425 * Release a journal_t structure once it is no longer in use by the
1426 * journaled object.
1427 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001428void jbd2_journal_destroy(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001429{
1430 /* Wait for the commit thread to wake up and die. */
1431 journal_kill_thread(journal);
1432
1433 /* Force a final log commit */
1434 if (journal->j_running_transaction)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001435 jbd2_journal_commit_transaction(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001436
1437 /* Force any old transactions to disk */
1438
1439 /* Totally anal locking here... */
1440 spin_lock(&journal->j_list_lock);
1441 while (journal->j_checkpoint_transactions != NULL) {
1442 spin_unlock(&journal->j_list_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001443 jbd2_log_do_checkpoint(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001444 spin_lock(&journal->j_list_lock);
1445 }
1446
1447 J_ASSERT(journal->j_running_transaction == NULL);
1448 J_ASSERT(journal->j_committing_transaction == NULL);
1449 J_ASSERT(journal->j_checkpoint_transactions == NULL);
1450 spin_unlock(&journal->j_list_lock);
1451
1452 /* We can now mark the journal as empty. */
1453 journal->j_tail = 0;
1454 journal->j_tail_sequence = ++journal->j_transaction_sequence;
1455 if (journal->j_sb_buffer) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001456 jbd2_journal_update_superblock(journal, 1);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001457 brelse(journal->j_sb_buffer);
1458 }
1459
Johann Lombardi8e85fb32008-01-28 23:58:27 -05001460 if (journal->j_proc_entry)
1461 jbd2_stats_proc_exit(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001462 if (journal->j_inode)
1463 iput(journal->j_inode);
1464 if (journal->j_revoke)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001465 jbd2_journal_destroy_revoke(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001466 kfree(journal->j_wbuf);
1467 kfree(journal);
1468}
1469
1470
1471/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001472 *int jbd2_journal_check_used_features () - Check if features specified are used.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001473 * @journal: Journal to check.
1474 * @compat: bitmask of compatible features
1475 * @ro: bitmask of features that force read-only mount
1476 * @incompat: bitmask of incompatible features
1477 *
1478 * Check whether the journal uses all of a given set of
1479 * features. Return true (non-zero) if it does.
1480 **/
1481
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001482int jbd2_journal_check_used_features (journal_t *journal, unsigned long compat,
Dave Kleikamp470decc2006-10-11 01:20:57 -07001483 unsigned long ro, unsigned long incompat)
1484{
1485 journal_superblock_t *sb;
1486
1487 if (!compat && !ro && !incompat)
1488 return 1;
1489 if (journal->j_format_version == 1)
1490 return 0;
1491
1492 sb = journal->j_superblock;
1493
1494 if (((be32_to_cpu(sb->s_feature_compat) & compat) == compat) &&
1495 ((be32_to_cpu(sb->s_feature_ro_compat) & ro) == ro) &&
1496 ((be32_to_cpu(sb->s_feature_incompat) & incompat) == incompat))
1497 return 1;
1498
1499 return 0;
1500}
1501
1502/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001503 * int jbd2_journal_check_available_features() - Check feature set in journalling layer
Dave Kleikamp470decc2006-10-11 01:20:57 -07001504 * @journal: Journal to check.
1505 * @compat: bitmask of compatible features
1506 * @ro: bitmask of features that force read-only mount
1507 * @incompat: bitmask of incompatible features
1508 *
1509 * Check whether the journaling code supports the use of
1510 * all of a given set of features on this journal. Return true
1511 * (non-zero) if it can. */
1512
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001513int jbd2_journal_check_available_features (journal_t *journal, unsigned long compat,
Dave Kleikamp470decc2006-10-11 01:20:57 -07001514 unsigned long ro, unsigned long incompat)
1515{
1516 journal_superblock_t *sb;
1517
1518 if (!compat && !ro && !incompat)
1519 return 1;
1520
1521 sb = journal->j_superblock;
1522
1523 /* We can support any known requested features iff the
1524 * superblock is in version 2. Otherwise we fail to support any
1525 * extended sb features. */
1526
1527 if (journal->j_format_version != 2)
1528 return 0;
1529
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001530 if ((compat & JBD2_KNOWN_COMPAT_FEATURES) == compat &&
1531 (ro & JBD2_KNOWN_ROCOMPAT_FEATURES) == ro &&
1532 (incompat & JBD2_KNOWN_INCOMPAT_FEATURES) == incompat)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001533 return 1;
1534
1535 return 0;
1536}
1537
1538/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001539 * int jbd2_journal_set_features () - Mark a given journal feature in the superblock
Dave Kleikamp470decc2006-10-11 01:20:57 -07001540 * @journal: Journal to act on.
1541 * @compat: bitmask of compatible features
1542 * @ro: bitmask of features that force read-only mount
1543 * @incompat: bitmask of incompatible features
1544 *
1545 * Mark a given journal feature as present on the
1546 * superblock. Returns true if the requested features could be set.
1547 *
1548 */
1549
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001550int jbd2_journal_set_features (journal_t *journal, unsigned long compat,
Dave Kleikamp470decc2006-10-11 01:20:57 -07001551 unsigned long ro, unsigned long incompat)
1552{
1553 journal_superblock_t *sb;
1554
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001555 if (jbd2_journal_check_used_features(journal, compat, ro, incompat))
Dave Kleikamp470decc2006-10-11 01:20:57 -07001556 return 1;
1557
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001558 if (!jbd2_journal_check_available_features(journal, compat, ro, incompat))
Dave Kleikamp470decc2006-10-11 01:20:57 -07001559 return 0;
1560
1561 jbd_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n",
1562 compat, ro, incompat);
1563
1564 sb = journal->j_superblock;
1565
1566 sb->s_feature_compat |= cpu_to_be32(compat);
1567 sb->s_feature_ro_compat |= cpu_to_be32(ro);
1568 sb->s_feature_incompat |= cpu_to_be32(incompat);
1569
1570 return 1;
1571}
1572
Girish Shilamkar818d2762008-01-28 23:58:27 -05001573/*
1574 * jbd2_journal_clear_features () - Clear a given journal feature in the
1575 * superblock
1576 * @journal: Journal to act on.
1577 * @compat: bitmask of compatible features
1578 * @ro: bitmask of features that force read-only mount
1579 * @incompat: bitmask of incompatible features
1580 *
1581 * Clear a given journal feature as present on the
1582 * superblock.
1583 */
1584void jbd2_journal_clear_features(journal_t *journal, unsigned long compat,
1585 unsigned long ro, unsigned long incompat)
1586{
1587 journal_superblock_t *sb;
1588
1589 jbd_debug(1, "Clear features 0x%lx/0x%lx/0x%lx\n",
1590 compat, ro, incompat);
1591
1592 sb = journal->j_superblock;
1593
1594 sb->s_feature_compat &= ~cpu_to_be32(compat);
1595 sb->s_feature_ro_compat &= ~cpu_to_be32(ro);
1596 sb->s_feature_incompat &= ~cpu_to_be32(incompat);
1597}
1598EXPORT_SYMBOL(jbd2_journal_clear_features);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001599
1600/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001601 * int jbd2_journal_update_format () - Update on-disk journal structure.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001602 * @journal: Journal to act on.
1603 *
1604 * Given an initialised but unloaded journal struct, poke about in the
1605 * on-disk structure to update it to the most recent supported version.
1606 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001607int jbd2_journal_update_format (journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001608{
1609 journal_superblock_t *sb;
1610 int err;
1611
1612 err = journal_get_superblock(journal);
1613 if (err)
1614 return err;
1615
1616 sb = journal->j_superblock;
1617
1618 switch (be32_to_cpu(sb->s_header.h_blocktype)) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001619 case JBD2_SUPERBLOCK_V2:
Dave Kleikamp470decc2006-10-11 01:20:57 -07001620 return 0;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001621 case JBD2_SUPERBLOCK_V1:
Dave Kleikamp470decc2006-10-11 01:20:57 -07001622 return journal_convert_superblock_v1(journal, sb);
1623 default:
1624 break;
1625 }
1626 return -EINVAL;
1627}
1628
1629static int journal_convert_superblock_v1(journal_t *journal,
1630 journal_superblock_t *sb)
1631{
1632 int offset, blocksize;
1633 struct buffer_head *bh;
1634
1635 printk(KERN_WARNING
1636 "JBD: Converting superblock from version 1 to 2.\n");
1637
1638 /* Pre-initialise new fields to zero */
1639 offset = ((char *) &(sb->s_feature_compat)) - ((char *) sb);
1640 blocksize = be32_to_cpu(sb->s_blocksize);
1641 memset(&sb->s_feature_compat, 0, blocksize-offset);
1642
1643 sb->s_nr_users = cpu_to_be32(1);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001644 sb->s_header.h_blocktype = cpu_to_be32(JBD2_SUPERBLOCK_V2);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001645 journal->j_format_version = 2;
1646
1647 bh = journal->j_sb_buffer;
1648 BUFFER_TRACE(bh, "marking dirty");
1649 mark_buffer_dirty(bh);
1650 sync_dirty_buffer(bh);
1651 return 0;
1652}
1653
1654
1655/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001656 * int jbd2_journal_flush () - Flush journal
Dave Kleikamp470decc2006-10-11 01:20:57 -07001657 * @journal: Journal to act on.
1658 *
1659 * Flush all data for a given journal to disk and empty the journal.
1660 * Filesystems can use this when remounting readonly to ensure that
1661 * recovery does not need to happen on remount.
1662 */
1663
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001664int jbd2_journal_flush(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001665{
1666 int err = 0;
1667 transaction_t *transaction = NULL;
1668 unsigned long old_tail;
1669
1670 spin_lock(&journal->j_state_lock);
1671
1672 /* Force everything buffered to the log... */
1673 if (journal->j_running_transaction) {
1674 transaction = journal->j_running_transaction;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001675 __jbd2_log_start_commit(journal, transaction->t_tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001676 } else if (journal->j_committing_transaction)
1677 transaction = journal->j_committing_transaction;
1678
1679 /* Wait for the log commit to complete... */
1680 if (transaction) {
1681 tid_t tid = transaction->t_tid;
1682
1683 spin_unlock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001684 jbd2_log_wait_commit(journal, tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001685 } else {
1686 spin_unlock(&journal->j_state_lock);
1687 }
1688
1689 /* ...and flush everything in the log out to disk. */
1690 spin_lock(&journal->j_list_lock);
1691 while (!err && journal->j_checkpoint_transactions != NULL) {
1692 spin_unlock(&journal->j_list_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001693 err = jbd2_log_do_checkpoint(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001694 spin_lock(&journal->j_list_lock);
1695 }
1696 spin_unlock(&journal->j_list_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001697 jbd2_cleanup_journal_tail(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001698
1699 /* Finally, mark the journal as really needing no recovery.
1700 * This sets s_start==0 in the underlying superblock, which is
1701 * the magic code for a fully-recovered superblock. Any future
1702 * commits of data to the journal will restore the current
1703 * s_start value. */
1704 spin_lock(&journal->j_state_lock);
1705 old_tail = journal->j_tail;
1706 journal->j_tail = 0;
1707 spin_unlock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001708 jbd2_journal_update_superblock(journal, 1);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001709 spin_lock(&journal->j_state_lock);
1710 journal->j_tail = old_tail;
1711
1712 J_ASSERT(!journal->j_running_transaction);
1713 J_ASSERT(!journal->j_committing_transaction);
1714 J_ASSERT(!journal->j_checkpoint_transactions);
1715 J_ASSERT(journal->j_head == journal->j_tail);
1716 J_ASSERT(journal->j_tail_sequence == journal->j_transaction_sequence);
1717 spin_unlock(&journal->j_state_lock);
1718 return err;
1719}
1720
1721/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001722 * int jbd2_journal_wipe() - Wipe journal contents
Dave Kleikamp470decc2006-10-11 01:20:57 -07001723 * @journal: Journal to act on.
1724 * @write: flag (see below)
1725 *
1726 * Wipe out all of the contents of a journal, safely. This will produce
1727 * a warning if the journal contains any valid recovery information.
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001728 * Must be called between journal_init_*() and jbd2_journal_load().
Dave Kleikamp470decc2006-10-11 01:20:57 -07001729 *
1730 * If 'write' is non-zero, then we wipe out the journal on disk; otherwise
1731 * we merely suppress recovery.
1732 */
1733
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001734int jbd2_journal_wipe(journal_t *journal, int write)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001735{
1736 journal_superblock_t *sb;
1737 int err = 0;
1738
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001739 J_ASSERT (!(journal->j_flags & JBD2_LOADED));
Dave Kleikamp470decc2006-10-11 01:20:57 -07001740
1741 err = load_superblock(journal);
1742 if (err)
1743 return err;
1744
1745 sb = journal->j_superblock;
1746
1747 if (!journal->j_tail)
1748 goto no_recovery;
1749
1750 printk (KERN_WARNING "JBD: %s recovery information on journal\n",
1751 write ? "Clearing" : "Ignoring");
1752
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001753 err = jbd2_journal_skip_recovery(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001754 if (write)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001755 jbd2_journal_update_superblock(journal, 1);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001756
1757 no_recovery:
1758 return err;
1759}
1760
1761/*
1762 * journal_dev_name: format a character string to describe on what
1763 * device this journal is present.
1764 */
1765
1766static const char *journal_dev_name(journal_t *journal, char *buffer)
1767{
1768 struct block_device *bdev;
1769
1770 if (journal->j_inode)
1771 bdev = journal->j_inode->i_sb->s_bdev;
1772 else
1773 bdev = journal->j_dev;
1774
1775 return bdevname(bdev, buffer);
1776}
1777
1778/*
1779 * Journal abort has very specific semantics, which we describe
1780 * for journal abort.
1781 *
1782 * Two internal function, which provide abort to te jbd layer
1783 * itself are here.
1784 */
1785
1786/*
1787 * Quick version for internal journal use (doesn't lock the journal).
1788 * Aborts hard --- we mark the abort as occurred, but do _nothing_ else,
1789 * and don't attempt to make any other journal updates.
1790 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001791void __jbd2_journal_abort_hard(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001792{
1793 transaction_t *transaction;
1794 char b[BDEVNAME_SIZE];
1795
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001796 if (journal->j_flags & JBD2_ABORT)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001797 return;
1798
1799 printk(KERN_ERR "Aborting journal on device %s.\n",
1800 journal_dev_name(journal, b));
1801
1802 spin_lock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001803 journal->j_flags |= JBD2_ABORT;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001804 transaction = journal->j_running_transaction;
1805 if (transaction)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001806 __jbd2_log_start_commit(journal, transaction->t_tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001807 spin_unlock(&journal->j_state_lock);
1808}
1809
1810/* Soft abort: record the abort error status in the journal superblock,
1811 * but don't do any other IO. */
1812static void __journal_abort_soft (journal_t *journal, int errno)
1813{
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001814 if (journal->j_flags & JBD2_ABORT)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001815 return;
1816
1817 if (!journal->j_errno)
1818 journal->j_errno = errno;
1819
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001820 __jbd2_journal_abort_hard(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001821
1822 if (errno)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001823 jbd2_journal_update_superblock(journal, 1);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001824}
1825
1826/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001827 * void jbd2_journal_abort () - Shutdown the journal immediately.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001828 * @journal: the journal to shutdown.
1829 * @errno: an error number to record in the journal indicating
1830 * the reason for the shutdown.
1831 *
1832 * Perform a complete, immediate shutdown of the ENTIRE
1833 * journal (not of a single transaction). This operation cannot be
1834 * undone without closing and reopening the journal.
1835 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001836 * The jbd2_journal_abort function is intended to support higher level error
Dave Kleikamp470decc2006-10-11 01:20:57 -07001837 * recovery mechanisms such as the ext2/ext3 remount-readonly error
1838 * mode.
1839 *
1840 * Journal abort has very specific semantics. Any existing dirty,
1841 * unjournaled buffers in the main filesystem will still be written to
1842 * disk by bdflush, but the journaling mechanism will be suspended
1843 * immediately and no further transaction commits will be honoured.
1844 *
1845 * Any dirty, journaled buffers will be written back to disk without
1846 * hitting the journal. Atomicity cannot be guaranteed on an aborted
1847 * filesystem, but we _do_ attempt to leave as much data as possible
1848 * behind for fsck to use for cleanup.
1849 *
1850 * Any attempt to get a new transaction handle on a journal which is in
1851 * ABORT state will just result in an -EROFS error return. A
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001852 * jbd2_journal_stop on an existing handle will return -EIO if we have
Dave Kleikamp470decc2006-10-11 01:20:57 -07001853 * entered abort state during the update.
1854 *
1855 * Recursive transactions are not disturbed by journal abort until the
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001856 * final jbd2_journal_stop, which will receive the -EIO error.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001857 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001858 * Finally, the jbd2_journal_abort call allows the caller to supply an errno
Dave Kleikamp470decc2006-10-11 01:20:57 -07001859 * which will be recorded (if possible) in the journal superblock. This
1860 * allows a client to record failure conditions in the middle of a
1861 * transaction without having to complete the transaction to record the
1862 * failure to disk. ext3_error, for example, now uses this
1863 * functionality.
1864 *
1865 * Errors which originate from within the journaling layer will NOT
1866 * supply an errno; a null errno implies that absolutely no further
1867 * writes are done to the journal (unless there are any already in
1868 * progress).
1869 *
1870 */
1871
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001872void jbd2_journal_abort(journal_t *journal, int errno)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001873{
1874 __journal_abort_soft(journal, errno);
1875}
1876
1877/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001878 * int jbd2_journal_errno () - returns the journal's error state.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001879 * @journal: journal to examine.
1880 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001881 * This is the errno numbet set with jbd2_journal_abort(), the last
Dave Kleikamp470decc2006-10-11 01:20:57 -07001882 * time the journal was mounted - if the journal was stopped
1883 * without calling abort this will be 0.
1884 *
1885 * If the journal has been aborted on this mount time -EROFS will
1886 * be returned.
1887 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001888int jbd2_journal_errno(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001889{
1890 int err;
1891
1892 spin_lock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001893 if (journal->j_flags & JBD2_ABORT)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001894 err = -EROFS;
1895 else
1896 err = journal->j_errno;
1897 spin_unlock(&journal->j_state_lock);
1898 return err;
1899}
1900
1901/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001902 * int jbd2_journal_clear_err () - clears the journal's error state
Dave Kleikamp470decc2006-10-11 01:20:57 -07001903 * @journal: journal to act on.
1904 *
1905 * An error must be cleared or Acked to take a FS out of readonly
1906 * mode.
1907 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001908int jbd2_journal_clear_err(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001909{
1910 int err = 0;
1911
1912 spin_lock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001913 if (journal->j_flags & JBD2_ABORT)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001914 err = -EROFS;
1915 else
1916 journal->j_errno = 0;
1917 spin_unlock(&journal->j_state_lock);
1918 return err;
1919}
1920
1921/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001922 * void jbd2_journal_ack_err() - Ack journal err.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001923 * @journal: journal to act on.
1924 *
1925 * An error must be cleared or Acked to take a FS out of readonly
1926 * mode.
1927 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001928void jbd2_journal_ack_err(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001929{
1930 spin_lock(&journal->j_state_lock);
1931 if (journal->j_errno)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001932 journal->j_flags |= JBD2_ACK_ERR;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001933 spin_unlock(&journal->j_state_lock);
1934}
1935
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001936int jbd2_journal_blocks_per_page(struct inode *inode)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001937{
1938 return 1 << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
1939}
1940
1941/*
Zach Brownb517bea2006-10-11 01:21:08 -07001942 * helper functions to deal with 32 or 64bit block numbers.
1943 */
1944size_t journal_tag_bytes(journal_t *journal)
1945{
1946 if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT))
Mingming Caocd02ff02007-10-16 18:38:25 -04001947 return JBD2_TAG_SIZE64;
Zach Brownb517bea2006-10-11 01:21:08 -07001948 else
Mingming Caocd02ff02007-10-16 18:38:25 -04001949 return JBD2_TAG_SIZE32;
Zach Brownb517bea2006-10-11 01:21:08 -07001950}
1951
1952/*
Dave Kleikamp470decc2006-10-11 01:20:57 -07001953 * Journal_head storage management
1954 */
Christoph Lametere18b8902006-12-06 20:33:20 -08001955static struct kmem_cache *jbd2_journal_head_cache;
Jose R. Santose23291b2007-07-18 08:57:06 -04001956#ifdef CONFIG_JBD2_DEBUG
Dave Kleikamp470decc2006-10-11 01:20:57 -07001957static atomic_t nr_journal_heads = ATOMIC_INIT(0);
1958#endif
1959
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001960static int journal_init_jbd2_journal_head_cache(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001961{
1962 int retval;
1963
Al Viro1076d172008-03-29 03:07:18 +00001964 J_ASSERT(jbd2_journal_head_cache == NULL);
Johann Lombardia920e942006-10-11 01:21:00 -07001965 jbd2_journal_head_cache = kmem_cache_create("jbd2_journal_head",
Dave Kleikamp470decc2006-10-11 01:20:57 -07001966 sizeof(struct journal_head),
1967 0, /* offset */
Mingming Cao77160952008-01-28 23:58:27 -05001968 SLAB_TEMPORARY, /* flags */
Paul Mundt20c2df82007-07-20 10:11:58 +09001969 NULL); /* ctor */
Dave Kleikamp470decc2006-10-11 01:20:57 -07001970 retval = 0;
Al Viro1076d172008-03-29 03:07:18 +00001971 if (!jbd2_journal_head_cache) {
Dave Kleikamp470decc2006-10-11 01:20:57 -07001972 retval = -ENOMEM;
1973 printk(KERN_EMERG "JBD: no memory for journal_head cache\n");
1974 }
1975 return retval;
1976}
1977
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001978static void jbd2_journal_destroy_jbd2_journal_head_cache(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001979{
Duane Griffin8a9362e2008-04-17 10:38:59 -04001980 if (jbd2_journal_head_cache) {
1981 kmem_cache_destroy(jbd2_journal_head_cache);
1982 jbd2_journal_head_cache = NULL;
1983 }
Dave Kleikamp470decc2006-10-11 01:20:57 -07001984}
1985
1986/*
1987 * journal_head splicing and dicing
1988 */
1989static struct journal_head *journal_alloc_journal_head(void)
1990{
1991 struct journal_head *ret;
1992 static unsigned long last_warning;
1993
Jose R. Santose23291b2007-07-18 08:57:06 -04001994#ifdef CONFIG_JBD2_DEBUG
Dave Kleikamp470decc2006-10-11 01:20:57 -07001995 atomic_inc(&nr_journal_heads);
1996#endif
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001997 ret = kmem_cache_alloc(jbd2_journal_head_cache, GFP_NOFS);
Al Viro1076d172008-03-29 03:07:18 +00001998 if (!ret) {
Dave Kleikamp470decc2006-10-11 01:20:57 -07001999 jbd_debug(1, "out of memory for journal_head\n");
2000 if (time_after(jiffies, last_warning + 5*HZ)) {
2001 printk(KERN_NOTICE "ENOMEM in %s, retrying.\n",
Harvey Harrison329d2912008-04-17 10:38:59 -04002002 __func__);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002003 last_warning = jiffies;
2004 }
Al Viro1076d172008-03-29 03:07:18 +00002005 while (!ret) {
Dave Kleikamp470decc2006-10-11 01:20:57 -07002006 yield();
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002007 ret = kmem_cache_alloc(jbd2_journal_head_cache, GFP_NOFS);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002008 }
2009 }
2010 return ret;
2011}
2012
2013static void journal_free_journal_head(struct journal_head *jh)
2014{
Jose R. Santose23291b2007-07-18 08:57:06 -04002015#ifdef CONFIG_JBD2_DEBUG
Dave Kleikamp470decc2006-10-11 01:20:57 -07002016 atomic_dec(&nr_journal_heads);
Mingming Caocd02ff02007-10-16 18:38:25 -04002017 memset(jh, JBD2_POISON_FREE, sizeof(*jh));
Dave Kleikamp470decc2006-10-11 01:20:57 -07002018#endif
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002019 kmem_cache_free(jbd2_journal_head_cache, jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002020}
2021
2022/*
2023 * A journal_head is attached to a buffer_head whenever JBD has an
2024 * interest in the buffer.
2025 *
2026 * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit
2027 * is set. This bit is tested in core kernel code where we need to take
2028 * JBD-specific actions. Testing the zeroness of ->b_private is not reliable
2029 * there.
2030 *
2031 * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one.
2032 *
2033 * When a buffer has its BH_JBD bit set it is immune from being released by
2034 * core kernel code, mainly via ->b_count.
2035 *
2036 * A journal_head may be detached from its buffer_head when the journal_head's
2037 * b_transaction, b_cp_transaction and b_next_transaction pointers are NULL.
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002038 * Various places in JBD call jbd2_journal_remove_journal_head() to indicate that the
Dave Kleikamp470decc2006-10-11 01:20:57 -07002039 * journal_head can be dropped if needed.
2040 *
2041 * Various places in the kernel want to attach a journal_head to a buffer_head
2042 * _before_ attaching the journal_head to a transaction. To protect the
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002043 * journal_head in this situation, jbd2_journal_add_journal_head elevates the
Dave Kleikamp470decc2006-10-11 01:20:57 -07002044 * journal_head's b_jcount refcount by one. The caller must call
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002045 * jbd2_journal_put_journal_head() to undo this.
Dave Kleikamp470decc2006-10-11 01:20:57 -07002046 *
2047 * So the typical usage would be:
2048 *
2049 * (Attach a journal_head if needed. Increments b_jcount)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002050 * struct journal_head *jh = jbd2_journal_add_journal_head(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002051 * ...
2052 * jh->b_transaction = xxx;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002053 * jbd2_journal_put_journal_head(jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002054 *
2055 * Now, the journal_head's b_jcount is zero, but it is safe from being released
2056 * because it has a non-zero b_transaction.
2057 */
2058
2059/*
2060 * Give a buffer_head a journal_head.
2061 *
2062 * Doesn't need the journal lock.
2063 * May sleep.
2064 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002065struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07002066{
2067 struct journal_head *jh;
2068 struct journal_head *new_jh = NULL;
2069
2070repeat:
2071 if (!buffer_jbd(bh)) {
2072 new_jh = journal_alloc_journal_head();
2073 memset(new_jh, 0, sizeof(*new_jh));
2074 }
2075
2076 jbd_lock_bh_journal_head(bh);
2077 if (buffer_jbd(bh)) {
2078 jh = bh2jh(bh);
2079 } else {
2080 J_ASSERT_BH(bh,
2081 (atomic_read(&bh->b_count) > 0) ||
2082 (bh->b_page && bh->b_page->mapping));
2083
2084 if (!new_jh) {
2085 jbd_unlock_bh_journal_head(bh);
2086 goto repeat;
2087 }
2088
2089 jh = new_jh;
2090 new_jh = NULL; /* We consumed it */
2091 set_buffer_jbd(bh);
2092 bh->b_private = jh;
2093 jh->b_bh = bh;
2094 get_bh(bh);
2095 BUFFER_TRACE(bh, "added journal_head");
2096 }
2097 jh->b_jcount++;
2098 jbd_unlock_bh_journal_head(bh);
2099 if (new_jh)
2100 journal_free_journal_head(new_jh);
2101 return bh->b_private;
2102}
2103
2104/*
2105 * Grab a ref against this buffer_head's journal_head. If it ended up not
2106 * having a journal_head, return NULL
2107 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002108struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07002109{
2110 struct journal_head *jh = NULL;
2111
2112 jbd_lock_bh_journal_head(bh);
2113 if (buffer_jbd(bh)) {
2114 jh = bh2jh(bh);
2115 jh->b_jcount++;
2116 }
2117 jbd_unlock_bh_journal_head(bh);
2118 return jh;
2119}
2120
2121static void __journal_remove_journal_head(struct buffer_head *bh)
2122{
2123 struct journal_head *jh = bh2jh(bh);
2124
2125 J_ASSERT_JH(jh, jh->b_jcount >= 0);
2126
2127 get_bh(bh);
2128 if (jh->b_jcount == 0) {
2129 if (jh->b_transaction == NULL &&
2130 jh->b_next_transaction == NULL &&
2131 jh->b_cp_transaction == NULL) {
2132 J_ASSERT_JH(jh, jh->b_jlist == BJ_None);
2133 J_ASSERT_BH(bh, buffer_jbd(bh));
2134 J_ASSERT_BH(bh, jh2bh(jh) == bh);
2135 BUFFER_TRACE(bh, "remove journal_head");
2136 if (jh->b_frozen_data) {
2137 printk(KERN_WARNING "%s: freeing "
2138 "b_frozen_data\n",
Harvey Harrison329d2912008-04-17 10:38:59 -04002139 __func__);
Mingming Caoaf1e76d2007-10-16 18:38:25 -04002140 jbd2_free(jh->b_frozen_data, bh->b_size);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002141 }
2142 if (jh->b_committed_data) {
2143 printk(KERN_WARNING "%s: freeing "
2144 "b_committed_data\n",
Harvey Harrison329d2912008-04-17 10:38:59 -04002145 __func__);
Mingming Caoaf1e76d2007-10-16 18:38:25 -04002146 jbd2_free(jh->b_committed_data, bh->b_size);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002147 }
2148 bh->b_private = NULL;
2149 jh->b_bh = NULL; /* debug, really */
2150 clear_buffer_jbd(bh);
2151 __brelse(bh);
2152 journal_free_journal_head(jh);
2153 } else {
2154 BUFFER_TRACE(bh, "journal_head was locked");
2155 }
2156 }
2157}
2158
2159/*
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002160 * jbd2_journal_remove_journal_head(): if the buffer isn't attached to a transaction
Dave Kleikamp470decc2006-10-11 01:20:57 -07002161 * and has a zero b_jcount then remove and release its journal_head. If we did
2162 * see that the buffer is not used by any transaction we also "logically"
2163 * decrement ->b_count.
2164 *
2165 * We in fact take an additional increment on ->b_count as a convenience,
2166 * because the caller usually wants to do additional things with the bh
2167 * after calling here.
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002168 * The caller of jbd2_journal_remove_journal_head() *must* run __brelse(bh) at some
Dave Kleikamp470decc2006-10-11 01:20:57 -07002169 * time. Once the caller has run __brelse(), the buffer is eligible for
2170 * reaping by try_to_free_buffers().
2171 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002172void jbd2_journal_remove_journal_head(struct buffer_head *bh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07002173{
2174 jbd_lock_bh_journal_head(bh);
2175 __journal_remove_journal_head(bh);
2176 jbd_unlock_bh_journal_head(bh);
2177}
2178
2179/*
2180 * Drop a reference on the passed journal_head. If it fell to zero then try to
2181 * release the journal_head from the buffer_head.
2182 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002183void jbd2_journal_put_journal_head(struct journal_head *jh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07002184{
2185 struct buffer_head *bh = jh2bh(jh);
2186
2187 jbd_lock_bh_journal_head(bh);
2188 J_ASSERT_JH(jh, jh->b_jcount > 0);
2189 --jh->b_jcount;
2190 if (!jh->b_jcount && !jh->b_transaction) {
2191 __journal_remove_journal_head(bh);
2192 __brelse(bh);
2193 }
2194 jbd_unlock_bh_journal_head(bh);
2195}
2196
2197/*
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002198 * debugfs tunables
Dave Kleikamp470decc2006-10-11 01:20:57 -07002199 */
Jose R. Santos6f38c742007-10-16 18:38:25 -04002200#ifdef CONFIG_JBD2_DEBUG
2201u8 jbd2_journal_enable_debug __read_mostly;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002202EXPORT_SYMBOL(jbd2_journal_enable_debug);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002203
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002204#define JBD2_DEBUG_NAME "jbd2-debug"
Dave Kleikamp470decc2006-10-11 01:20:57 -07002205
Jose R. Santos6f38c742007-10-16 18:38:25 -04002206static struct dentry *jbd2_debugfs_dir;
2207static struct dentry *jbd2_debug;
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002208
2209static void __init jbd2_create_debugfs_entry(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07002210{
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002211 jbd2_debugfs_dir = debugfs_create_dir("jbd2", NULL);
2212 if (jbd2_debugfs_dir)
2213 jbd2_debug = debugfs_create_u8(JBD2_DEBUG_NAME, S_IRUGO,
2214 jbd2_debugfs_dir,
2215 &jbd2_journal_enable_debug);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002216}
2217
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002218static void __exit jbd2_remove_debugfs_entry(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07002219{
Jose R. Santos6f38c742007-10-16 18:38:25 -04002220 debugfs_remove(jbd2_debug);
2221 debugfs_remove(jbd2_debugfs_dir);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002222}
2223
2224#else
2225
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002226static void __init jbd2_create_debugfs_entry(void)
2227{
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002228}
2229
2230static void __exit jbd2_remove_debugfs_entry(void)
2231{
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002232}
Dave Kleikamp470decc2006-10-11 01:20:57 -07002233
2234#endif
2235
Johann Lombardi8e85fb32008-01-28 23:58:27 -05002236#ifdef CONFIG_PROC_FS
2237
2238#define JBD2_STATS_PROC_NAME "fs/jbd2"
2239
2240static void __init jbd2_create_jbd_stats_proc_entry(void)
2241{
2242 proc_jbd2_stats = proc_mkdir(JBD2_STATS_PROC_NAME, NULL);
2243}
2244
2245static void __exit jbd2_remove_jbd_stats_proc_entry(void)
2246{
2247 if (proc_jbd2_stats)
2248 remove_proc_entry(JBD2_STATS_PROC_NAME, NULL);
2249}
2250
2251#else
2252
2253#define jbd2_create_jbd_stats_proc_entry() do {} while (0)
2254#define jbd2_remove_jbd_stats_proc_entry() do {} while (0)
2255
2256#endif
2257
Christoph Lametere18b8902006-12-06 20:33:20 -08002258struct kmem_cache *jbd2_handle_cache;
Dave Kleikamp470decc2006-10-11 01:20:57 -07002259
2260static int __init journal_init_handle_cache(void)
2261{
Johann Lombardia920e942006-10-11 01:21:00 -07002262 jbd2_handle_cache = kmem_cache_create("jbd2_journal_handle",
Dave Kleikamp470decc2006-10-11 01:20:57 -07002263 sizeof(handle_t),
2264 0, /* offset */
Mingming Cao77160952008-01-28 23:58:27 -05002265 SLAB_TEMPORARY, /* flags */
Paul Mundt20c2df82007-07-20 10:11:58 +09002266 NULL); /* ctor */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002267 if (jbd2_handle_cache == NULL) {
Dave Kleikamp470decc2006-10-11 01:20:57 -07002268 printk(KERN_EMERG "JBD: failed to create handle cache\n");
2269 return -ENOMEM;
2270 }
2271 return 0;
2272}
2273
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002274static void jbd2_journal_destroy_handle_cache(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07002275{
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002276 if (jbd2_handle_cache)
2277 kmem_cache_destroy(jbd2_handle_cache);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002278}
2279
2280/*
2281 * Module startup and shutdown
2282 */
2283
2284static int __init journal_init_caches(void)
2285{
2286 int ret;
2287
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002288 ret = jbd2_journal_init_revoke_caches();
Dave Kleikamp470decc2006-10-11 01:20:57 -07002289 if (ret == 0)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002290 ret = journal_init_jbd2_journal_head_cache();
Dave Kleikamp470decc2006-10-11 01:20:57 -07002291 if (ret == 0)
2292 ret = journal_init_handle_cache();
2293 return ret;
2294}
2295
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002296static void jbd2_journal_destroy_caches(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07002297{
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002298 jbd2_journal_destroy_revoke_caches();
2299 jbd2_journal_destroy_jbd2_journal_head_cache();
2300 jbd2_journal_destroy_handle_cache();
Dave Kleikamp470decc2006-10-11 01:20:57 -07002301}
2302
2303static int __init journal_init(void)
2304{
2305 int ret;
2306
2307 BUILD_BUG_ON(sizeof(struct journal_superblock_s) != 1024);
2308
2309 ret = journal_init_caches();
Duane Griffin620de4e2008-04-29 22:02:47 -04002310 if (ret == 0) {
2311 jbd2_create_debugfs_entry();
2312 jbd2_create_jbd_stats_proc_entry();
2313 } else {
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002314 jbd2_journal_destroy_caches();
Duane Griffin620de4e2008-04-29 22:02:47 -04002315 }
Dave Kleikamp470decc2006-10-11 01:20:57 -07002316 return ret;
2317}
2318
2319static void __exit journal_exit(void)
2320{
Jose R. Santose23291b2007-07-18 08:57:06 -04002321#ifdef CONFIG_JBD2_DEBUG
Dave Kleikamp470decc2006-10-11 01:20:57 -07002322 int n = atomic_read(&nr_journal_heads);
2323 if (n)
2324 printk(KERN_EMERG "JBD: leaked %d journal_heads!\n", n);
2325#endif
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002326 jbd2_remove_debugfs_entry();
Johann Lombardi8e85fb32008-01-28 23:58:27 -05002327 jbd2_remove_jbd_stats_proc_entry();
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002328 jbd2_journal_destroy_caches();
Dave Kleikamp470decc2006-10-11 01:20:57 -07002329}
2330
2331MODULE_LICENSE("GPL");
2332module_init(journal_init);
2333module_exit(journal_exit);
2334