blob: 6ddc5531587c7c6598180f105e46645f13d74337 [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>
Dave Kleikamp470decc2006-10-11 01:20:57 -070039
40#include <asm/uaccess.h>
41#include <asm/page.h>
42
Mingming Caof7f4bcc2006-10-11 01:20:59 -070043EXPORT_SYMBOL(jbd2_journal_start);
44EXPORT_SYMBOL(jbd2_journal_restart);
45EXPORT_SYMBOL(jbd2_journal_extend);
46EXPORT_SYMBOL(jbd2_journal_stop);
47EXPORT_SYMBOL(jbd2_journal_lock_updates);
48EXPORT_SYMBOL(jbd2_journal_unlock_updates);
49EXPORT_SYMBOL(jbd2_journal_get_write_access);
50EXPORT_SYMBOL(jbd2_journal_get_create_access);
51EXPORT_SYMBOL(jbd2_journal_get_undo_access);
52EXPORT_SYMBOL(jbd2_journal_dirty_data);
53EXPORT_SYMBOL(jbd2_journal_dirty_metadata);
54EXPORT_SYMBOL(jbd2_journal_release_buffer);
55EXPORT_SYMBOL(jbd2_journal_forget);
Dave Kleikamp470decc2006-10-11 01:20:57 -070056#if 0
57EXPORT_SYMBOL(journal_sync_buffer);
58#endif
Mingming Caof7f4bcc2006-10-11 01:20:59 -070059EXPORT_SYMBOL(jbd2_journal_flush);
60EXPORT_SYMBOL(jbd2_journal_revoke);
Dave Kleikamp470decc2006-10-11 01:20:57 -070061
Mingming Caof7f4bcc2006-10-11 01:20:59 -070062EXPORT_SYMBOL(jbd2_journal_init_dev);
63EXPORT_SYMBOL(jbd2_journal_init_inode);
64EXPORT_SYMBOL(jbd2_journal_update_format);
65EXPORT_SYMBOL(jbd2_journal_check_used_features);
66EXPORT_SYMBOL(jbd2_journal_check_available_features);
67EXPORT_SYMBOL(jbd2_journal_set_features);
68EXPORT_SYMBOL(jbd2_journal_create);
69EXPORT_SYMBOL(jbd2_journal_load);
70EXPORT_SYMBOL(jbd2_journal_destroy);
71EXPORT_SYMBOL(jbd2_journal_update_superblock);
72EXPORT_SYMBOL(jbd2_journal_abort);
73EXPORT_SYMBOL(jbd2_journal_errno);
74EXPORT_SYMBOL(jbd2_journal_ack_err);
75EXPORT_SYMBOL(jbd2_journal_clear_err);
76EXPORT_SYMBOL(jbd2_log_wait_commit);
77EXPORT_SYMBOL(jbd2_journal_start_commit);
78EXPORT_SYMBOL(jbd2_journal_force_commit_nested);
79EXPORT_SYMBOL(jbd2_journal_wipe);
80EXPORT_SYMBOL(jbd2_journal_blocks_per_page);
81EXPORT_SYMBOL(jbd2_journal_invalidatepage);
82EXPORT_SYMBOL(jbd2_journal_try_to_free_buffers);
83EXPORT_SYMBOL(jbd2_journal_force_commit);
Dave Kleikamp470decc2006-10-11 01:20:57 -070084
85static int journal_convert_superblock_v1(journal_t *, journal_superblock_t *);
86static void __journal_abort_soft (journal_t *journal, int errno);
Dave Kleikamp470decc2006-10-11 01:20:57 -070087
88/*
89 * Helper function used to manage commit timeouts
90 */
91
92static void commit_timeout(unsigned long __data)
93{
94 struct task_struct * p = (struct task_struct *) __data;
95
96 wake_up_process(p);
97}
98
99/*
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700100 * kjournald2: The main thread function used to manage a logging device
Dave Kleikamp470decc2006-10-11 01:20:57 -0700101 * journal.
102 *
103 * This kernel thread is responsible for two things:
104 *
105 * 1) COMMIT: Every so often we need to commit the current state of the
106 * filesystem to disk. The journal thread is responsible for writing
107 * all of the metadata buffers to disk.
108 *
109 * 2) CHECKPOINT: We cannot reuse a used section of the log file until all
110 * of the data in that part of the log has been rewritten elsewhere on
111 * the disk. Flushing these old buffers to reclaim space in the log is
112 * known as checkpointing, and this thread is responsible for that job.
113 */
114
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700115static int kjournald2(void *arg)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700116{
117 journal_t *journal = arg;
118 transaction_t *transaction;
119
120 /*
121 * Set up an interval timer which can be used to trigger a commit wakeup
122 * after the commit interval expires
123 */
124 setup_timer(&journal->j_commit_timer, commit_timeout,
125 (unsigned long)current);
126
127 /* Record that the journal thread is running */
128 journal->j_task = current;
129 wake_up(&journal->j_wait_done_commit);
130
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700131 printk(KERN_INFO "kjournald2 starting. Commit interval %ld seconds\n",
Dave Kleikamp470decc2006-10-11 01:20:57 -0700132 journal->j_commit_interval / HZ);
133
134 /*
135 * And now, wait forever for commit wakeup events.
136 */
137 spin_lock(&journal->j_state_lock);
138
139loop:
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700140 if (journal->j_flags & JBD2_UNMOUNT)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700141 goto end_loop;
142
143 jbd_debug(1, "commit_sequence=%d, commit_request=%d\n",
144 journal->j_commit_sequence, journal->j_commit_request);
145
146 if (journal->j_commit_sequence != journal->j_commit_request) {
147 jbd_debug(1, "OK, requests differ\n");
148 spin_unlock(&journal->j_state_lock);
149 del_timer_sync(&journal->j_commit_timer);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700150 jbd2_journal_commit_transaction(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700151 spin_lock(&journal->j_state_lock);
152 goto loop;
153 }
154
155 wake_up(&journal->j_wait_done_commit);
156 if (freezing(current)) {
157 /*
158 * The simpler the better. Flushing journal isn't a
159 * good idea, because that depends on threads that may
160 * be already stopped.
161 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700162 jbd_debug(1, "Now suspending kjournald2\n");
Dave Kleikamp470decc2006-10-11 01:20:57 -0700163 spin_unlock(&journal->j_state_lock);
164 refrigerator();
165 spin_lock(&journal->j_state_lock);
166 } else {
167 /*
168 * We assume on resume that commits are already there,
169 * so we don't sleep
170 */
171 DEFINE_WAIT(wait);
172 int should_sleep = 1;
173
174 prepare_to_wait(&journal->j_wait_commit, &wait,
175 TASK_INTERRUPTIBLE);
176 if (journal->j_commit_sequence != journal->j_commit_request)
177 should_sleep = 0;
178 transaction = journal->j_running_transaction;
179 if (transaction && time_after_eq(jiffies,
180 transaction->t_expires))
181 should_sleep = 0;
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700182 if (journal->j_flags & JBD2_UNMOUNT)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700183 should_sleep = 0;
184 if (should_sleep) {
185 spin_unlock(&journal->j_state_lock);
186 schedule();
187 spin_lock(&journal->j_state_lock);
188 }
189 finish_wait(&journal->j_wait_commit, &wait);
190 }
191
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700192 jbd_debug(1, "kjournald2 wakes\n");
Dave Kleikamp470decc2006-10-11 01:20:57 -0700193
194 /*
195 * Were we woken up by a commit wakeup event?
196 */
197 transaction = journal->j_running_transaction;
198 if (transaction && time_after_eq(jiffies, transaction->t_expires)) {
199 journal->j_commit_request = transaction->t_tid;
200 jbd_debug(1, "woke because of timeout\n");
201 }
202 goto loop;
203
204end_loop:
205 spin_unlock(&journal->j_state_lock);
206 del_timer_sync(&journal->j_commit_timer);
207 journal->j_task = NULL;
208 wake_up(&journal->j_wait_done_commit);
209 jbd_debug(1, "Journal thread exiting.\n");
210 return 0;
211}
212
Pavel Emelianov97f06782007-05-08 00:30:42 -0700213static int jbd2_journal_start_thread(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700214{
Pavel Emelianov97f06782007-05-08 00:30:42 -0700215 struct task_struct *t;
216
217 t = kthread_run(kjournald2, journal, "kjournald2");
218 if (IS_ERR(t))
219 return PTR_ERR(t);
220
Dave Kleikamp470decc2006-10-11 01:20:57 -0700221 wait_event(journal->j_wait_done_commit, journal->j_task != 0);
Pavel Emelianov97f06782007-05-08 00:30:42 -0700222 return 0;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700223}
224
225static void journal_kill_thread(journal_t *journal)
226{
227 spin_lock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700228 journal->j_flags |= JBD2_UNMOUNT;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700229
230 while (journal->j_task) {
231 wake_up(&journal->j_wait_commit);
232 spin_unlock(&journal->j_state_lock);
233 wait_event(journal->j_wait_done_commit, journal->j_task == 0);
234 spin_lock(&journal->j_state_lock);
235 }
236 spin_unlock(&journal->j_state_lock);
237}
238
239/*
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700240 * jbd2_journal_write_metadata_buffer: write a metadata buffer to the journal.
Dave Kleikamp470decc2006-10-11 01:20:57 -0700241 *
242 * Writes a metadata buffer to a given disk block. The actual IO is not
243 * performed but a new buffer_head is constructed which labels the data
244 * to be written with the correct destination disk block.
245 *
246 * Any magic-number escaping which needs to be done will cause a
247 * copy-out here. If the buffer happens to start with the
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700248 * JBD2_MAGIC_NUMBER, then we can't write it to the log directly: the
Dave Kleikamp470decc2006-10-11 01:20:57 -0700249 * magic number is only written to the log for descripter blocks. In
250 * this case, we copy the data and replace the first word with 0, and we
251 * return a result code which indicates that this buffer needs to be
252 * marked as an escaped buffer in the corresponding log descriptor
253 * block. The missing word can then be restored when the block is read
254 * during recovery.
255 *
256 * If the source buffer has already been modified by a new transaction
257 * since we took the last commit snapshot, we use the frozen copy of
258 * that data for IO. If we end up using the existing buffer_head's data
259 * for the write, then we *have* to lock the buffer to prevent anyone
260 * else from using and possibly modifying it while the IO is in
261 * progress.
262 *
263 * The function returns a pointer to the buffer_heads to be used for IO.
264 *
265 * We assume that the journal has already been locked in this function.
266 *
267 * Return value:
268 * <0: Error
269 * >=0: Finished OK
270 *
271 * On success:
272 * Bit 0 set == escape performed on the data
273 * Bit 1 set == buffer copy-out performed (kfree the data after IO)
274 */
275
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700276int jbd2_journal_write_metadata_buffer(transaction_t *transaction,
Dave Kleikamp470decc2006-10-11 01:20:57 -0700277 struct journal_head *jh_in,
278 struct journal_head **jh_out,
Mingming Cao18eba7a2006-10-11 01:21:13 -0700279 unsigned long long blocknr)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700280{
281 int need_copy_out = 0;
282 int done_copy_out = 0;
283 int do_escape = 0;
284 char *mapped_data;
285 struct buffer_head *new_bh;
286 struct journal_head *new_jh;
287 struct page *new_page;
288 unsigned int new_offset;
289 struct buffer_head *bh_in = jh2bh(jh_in);
290
291 /*
292 * The buffer really shouldn't be locked: only the current committing
293 * transaction is allowed to write it, so nobody else is allowed
294 * to do any IO.
295 *
296 * akpm: except if we're journalling data, and write() output is
297 * also part of a shared mapping, and another thread has
298 * decided to launch a writepage() against this buffer.
299 */
300 J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in));
301
302 new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL);
303
304 /*
305 * If a new transaction has already done a buffer copy-out, then
306 * we use that version of the data for the commit.
307 */
308 jbd_lock_bh_state(bh_in);
309repeat:
310 if (jh_in->b_frozen_data) {
311 done_copy_out = 1;
312 new_page = virt_to_page(jh_in->b_frozen_data);
313 new_offset = offset_in_page(jh_in->b_frozen_data);
314 } else {
315 new_page = jh2bh(jh_in)->b_page;
316 new_offset = offset_in_page(jh2bh(jh_in)->b_data);
317 }
318
319 mapped_data = kmap_atomic(new_page, KM_USER0);
320 /*
321 * Check for escaping
322 */
323 if (*((__be32 *)(mapped_data + new_offset)) ==
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700324 cpu_to_be32(JBD2_MAGIC_NUMBER)) {
Dave Kleikamp470decc2006-10-11 01:20:57 -0700325 need_copy_out = 1;
326 do_escape = 1;
327 }
328 kunmap_atomic(mapped_data, KM_USER0);
329
330 /*
331 * Do we need to do a data copy?
332 */
333 if (need_copy_out && !done_copy_out) {
334 char *tmp;
335
336 jbd_unlock_bh_state(bh_in);
Mingming Caoaf1e76d2007-10-16 18:38:25 -0400337 tmp = jbd2_alloc(bh_in->b_size, GFP_NOFS);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700338 jbd_lock_bh_state(bh_in);
339 if (jh_in->b_frozen_data) {
Mingming Caoaf1e76d2007-10-16 18:38:25 -0400340 jbd2_free(tmp, bh_in->b_size);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700341 goto repeat;
342 }
343
344 jh_in->b_frozen_data = tmp;
345 mapped_data = kmap_atomic(new_page, KM_USER0);
346 memcpy(tmp, mapped_data + new_offset, jh2bh(jh_in)->b_size);
347 kunmap_atomic(mapped_data, KM_USER0);
348
349 new_page = virt_to_page(tmp);
350 new_offset = offset_in_page(tmp);
351 done_copy_out = 1;
352 }
353
354 /*
355 * Did we need to do an escaping? Now we've done all the
356 * copying, we can finally do so.
357 */
358 if (do_escape) {
359 mapped_data = kmap_atomic(new_page, KM_USER0);
360 *((unsigned int *)(mapped_data + new_offset)) = 0;
361 kunmap_atomic(mapped_data, KM_USER0);
362 }
363
364 /* keep subsequent assertions sane */
365 new_bh->b_state = 0;
366 init_buffer(new_bh, NULL, NULL);
367 atomic_set(&new_bh->b_count, 1);
368 jbd_unlock_bh_state(bh_in);
369
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700370 new_jh = jbd2_journal_add_journal_head(new_bh); /* This sleeps */
Dave Kleikamp470decc2006-10-11 01:20:57 -0700371
372 set_bh_page(new_bh, new_page, new_offset);
373 new_jh->b_transaction = NULL;
374 new_bh->b_size = jh2bh(jh_in)->b_size;
375 new_bh->b_bdev = transaction->t_journal->j_dev;
376 new_bh->b_blocknr = blocknr;
377 set_buffer_mapped(new_bh);
378 set_buffer_dirty(new_bh);
379
380 *jh_out = new_jh;
381
382 /*
383 * The to-be-written buffer needs to get moved to the io queue,
384 * and the original buffer whose contents we are shadowing or
385 * copying is moved to the transaction's shadow queue.
386 */
387 JBUFFER_TRACE(jh_in, "file as BJ_Shadow");
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700388 jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700389 JBUFFER_TRACE(new_jh, "file as BJ_IO");
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700390 jbd2_journal_file_buffer(new_jh, transaction, BJ_IO);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700391
392 return do_escape | (done_copy_out << 1);
393}
394
395/*
396 * Allocation code for the journal file. Manage the space left in the
397 * journal, so that we can begin checkpointing when appropriate.
398 */
399
400/*
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700401 * __jbd2_log_space_left: Return the number of free blocks left in the journal.
Dave Kleikamp470decc2006-10-11 01:20:57 -0700402 *
403 * Called with the journal already locked.
404 *
405 * Called under j_state_lock
406 */
407
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700408int __jbd2_log_space_left(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700409{
410 int left = journal->j_free;
411
412 assert_spin_locked(&journal->j_state_lock);
413
414 /*
415 * Be pessimistic here about the number of those free blocks which
416 * might be required for log descriptor control blocks.
417 */
418
419#define MIN_LOG_RESERVED_BLOCKS 32 /* Allow for rounding errors */
420
421 left -= MIN_LOG_RESERVED_BLOCKS;
422
423 if (left <= 0)
424 return 0;
425 left -= (left >> 3);
426 return left;
427}
428
429/*
430 * Called under j_state_lock. Returns true if a transaction was started.
431 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700432int __jbd2_log_start_commit(journal_t *journal, tid_t target)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700433{
434 /*
435 * Are we already doing a recent enough commit?
436 */
437 if (!tid_geq(journal->j_commit_request, target)) {
438 /*
439 * We want a new commit: OK, mark the request and wakup the
440 * commit thread. We do _not_ do the commit ourselves.
441 */
442
443 journal->j_commit_request = target;
444 jbd_debug(1, "JBD: requesting commit %d/%d\n",
445 journal->j_commit_request,
446 journal->j_commit_sequence);
447 wake_up(&journal->j_wait_commit);
448 return 1;
449 }
450 return 0;
451}
452
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700453int jbd2_log_start_commit(journal_t *journal, tid_t tid)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700454{
455 int ret;
456
457 spin_lock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700458 ret = __jbd2_log_start_commit(journal, tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700459 spin_unlock(&journal->j_state_lock);
460 return ret;
461}
462
463/*
464 * Force and wait upon a commit if the calling process is not within
465 * transaction. This is used for forcing out undo-protected data which contains
466 * bitmaps, when the fs is running out of space.
467 *
468 * We can only force the running transaction if we don't have an active handle;
469 * otherwise, we will deadlock.
470 *
471 * Returns true if a transaction was started.
472 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700473int jbd2_journal_force_commit_nested(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700474{
475 transaction_t *transaction = NULL;
476 tid_t tid;
477
478 spin_lock(&journal->j_state_lock);
479 if (journal->j_running_transaction && !current->journal_info) {
480 transaction = journal->j_running_transaction;
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700481 __jbd2_log_start_commit(journal, transaction->t_tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700482 } else if (journal->j_committing_transaction)
483 transaction = journal->j_committing_transaction;
484
485 if (!transaction) {
486 spin_unlock(&journal->j_state_lock);
487 return 0; /* Nothing to retry */
488 }
489
490 tid = transaction->t_tid;
491 spin_unlock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700492 jbd2_log_wait_commit(journal, tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700493 return 1;
494}
495
496/*
497 * Start a commit of the current running transaction (if any). Returns true
498 * if a transaction was started, and fills its tid in at *ptid
499 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700500int jbd2_journal_start_commit(journal_t *journal, tid_t *ptid)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700501{
502 int ret = 0;
503
504 spin_lock(&journal->j_state_lock);
505 if (journal->j_running_transaction) {
506 tid_t tid = journal->j_running_transaction->t_tid;
507
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700508 ret = __jbd2_log_start_commit(journal, tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700509 if (ret && ptid)
510 *ptid = tid;
511 } else if (journal->j_committing_transaction && ptid) {
512 /*
513 * If ext3_write_super() recently started a commit, then we
514 * have to wait for completion of that transaction
515 */
516 *ptid = journal->j_committing_transaction->t_tid;
517 ret = 1;
518 }
519 spin_unlock(&journal->j_state_lock);
520 return ret;
521}
522
523/*
524 * Wait for a specified commit to complete.
525 * The caller may not hold the journal lock.
526 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700527int jbd2_log_wait_commit(journal_t *journal, tid_t tid)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700528{
529 int err = 0;
530
Jose R. Santose23291b2007-07-18 08:57:06 -0400531#ifdef CONFIG_JBD2_DEBUG
Dave Kleikamp470decc2006-10-11 01:20:57 -0700532 spin_lock(&journal->j_state_lock);
533 if (!tid_geq(journal->j_commit_request, tid)) {
534 printk(KERN_EMERG
535 "%s: error: j_commit_request=%d, tid=%d\n",
536 __FUNCTION__, journal->j_commit_request, tid);
537 }
538 spin_unlock(&journal->j_state_lock);
539#endif
540 spin_lock(&journal->j_state_lock);
541 while (tid_gt(tid, journal->j_commit_sequence)) {
542 jbd_debug(1, "JBD: want %d, j_commit_sequence=%d\n",
543 tid, journal->j_commit_sequence);
544 wake_up(&journal->j_wait_commit);
545 spin_unlock(&journal->j_state_lock);
546 wait_event(journal->j_wait_done_commit,
547 !tid_gt(tid, journal->j_commit_sequence));
548 spin_lock(&journal->j_state_lock);
549 }
550 spin_unlock(&journal->j_state_lock);
551
552 if (unlikely(is_journal_aborted(journal))) {
553 printk(KERN_EMERG "journal commit I/O error\n");
554 err = -EIO;
555 }
556 return err;
557}
558
559/*
560 * Log buffer allocation routines:
561 */
562
Mingming Cao18eba7a2006-10-11 01:21:13 -0700563int jbd2_journal_next_log_block(journal_t *journal, unsigned long long *retp)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700564{
565 unsigned long blocknr;
566
567 spin_lock(&journal->j_state_lock);
568 J_ASSERT(journal->j_free > 1);
569
570 blocknr = journal->j_head;
571 journal->j_head++;
572 journal->j_free--;
573 if (journal->j_head == journal->j_last)
574 journal->j_head = journal->j_first;
575 spin_unlock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700576 return jbd2_journal_bmap(journal, blocknr, retp);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700577}
578
579/*
580 * Conversion of logical to physical block numbers for the journal
581 *
582 * On external journals the journal blocks are identity-mapped, so
583 * this is a no-op. If needed, we can use j_blk_offset - everything is
584 * ready.
585 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700586int jbd2_journal_bmap(journal_t *journal, unsigned long blocknr,
Mingming Cao18eba7a2006-10-11 01:21:13 -0700587 unsigned long long *retp)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700588{
589 int err = 0;
Mingming Cao18eba7a2006-10-11 01:21:13 -0700590 unsigned long long ret;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700591
592 if (journal->j_inode) {
593 ret = bmap(journal->j_inode, blocknr);
594 if (ret)
595 *retp = ret;
596 else {
597 char b[BDEVNAME_SIZE];
598
599 printk(KERN_ALERT "%s: journal block not found "
600 "at offset %lu on %s\n",
601 __FUNCTION__,
602 blocknr,
603 bdevname(journal->j_dev, b));
604 err = -EIO;
605 __journal_abort_soft(journal, err);
606 }
607 } else {
608 *retp = blocknr; /* +journal->j_blk_offset */
609 }
610 return err;
611}
612
613/*
614 * We play buffer_head aliasing tricks to write data/metadata blocks to
615 * the journal without copying their contents, but for journal
616 * descriptor blocks we do need to generate bona fide buffers.
617 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700618 * After the caller of jbd2_journal_get_descriptor_buffer() has finished modifying
Dave Kleikamp470decc2006-10-11 01:20:57 -0700619 * the buffer's contents they really should run flush_dcache_page(bh->b_page).
620 * But we don't bother doing that, so there will be coherency problems with
621 * mmaps of blockdevs which hold live JBD-controlled filesystems.
622 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700623struct journal_head *jbd2_journal_get_descriptor_buffer(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700624{
625 struct buffer_head *bh;
Mingming Cao18eba7a2006-10-11 01:21:13 -0700626 unsigned long long blocknr;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700627 int err;
628
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700629 err = jbd2_journal_next_log_block(journal, &blocknr);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700630
631 if (err)
632 return NULL;
633
634 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
635 lock_buffer(bh);
636 memset(bh->b_data, 0, journal->j_blocksize);
637 set_buffer_uptodate(bh);
638 unlock_buffer(bh);
639 BUFFER_TRACE(bh, "return this buffer");
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700640 return jbd2_journal_add_journal_head(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700641}
642
643/*
644 * Management for journal control blocks: functions to create and
645 * destroy journal_t structures, and to initialise and read existing
646 * journal blocks from disk. */
647
648/* First: create and setup a journal_t object in memory. We initialise
649 * very few fields yet: that has to wait until we have created the
650 * journal structures from from scratch, or loaded them from disk. */
651
652static journal_t * journal_init_common (void)
653{
654 journal_t *journal;
655 int err;
656
Mingming Caod802ffa2007-10-16 18:38:25 -0400657 journal = kzalloc(sizeof(*journal), GFP_KERNEL|__GFP_NOFAIL);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700658 if (!journal)
659 goto fail;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700660
661 init_waitqueue_head(&journal->j_wait_transaction_locked);
662 init_waitqueue_head(&journal->j_wait_logspace);
663 init_waitqueue_head(&journal->j_wait_done_commit);
664 init_waitqueue_head(&journal->j_wait_checkpoint);
665 init_waitqueue_head(&journal->j_wait_commit);
666 init_waitqueue_head(&journal->j_wait_updates);
667 mutex_init(&journal->j_barrier);
668 mutex_init(&journal->j_checkpoint_mutex);
669 spin_lock_init(&journal->j_revoke_lock);
670 spin_lock_init(&journal->j_list_lock);
671 spin_lock_init(&journal->j_state_lock);
672
Mingming Caocd02ff02007-10-16 18:38:25 -0400673 journal->j_commit_interval = (HZ * JBD2_DEFAULT_MAX_COMMIT_AGE);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700674
675 /* The journal is marked for error until we succeed with recovery! */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700676 journal->j_flags = JBD2_ABORT;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700677
678 /* Set up a default-sized revoke table for the new mount. */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700679 err = jbd2_journal_init_revoke(journal, JOURNAL_REVOKE_DEFAULT_HASH);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700680 if (err) {
681 kfree(journal);
682 goto fail;
683 }
684 return journal;
685fail:
686 return NULL;
687}
688
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700689/* jbd2_journal_init_dev and jbd2_journal_init_inode:
Dave Kleikamp470decc2006-10-11 01:20:57 -0700690 *
691 * Create a journal structure assigned some fixed set of disk blocks to
692 * the journal. We don't actually touch those disk blocks yet, but we
693 * need to set up all of the mapping information to tell the journaling
694 * system where the journal blocks are.
695 *
696 */
697
698/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700699 * journal_t * jbd2_journal_init_dev() - creates an initialises a journal structure
Dave Kleikamp470decc2006-10-11 01:20:57 -0700700 * @bdev: Block device on which to create the journal
701 * @fs_dev: Device which hold journalled filesystem for this journal.
702 * @start: Block nr Start of journal.
703 * @len: Length of the journal in blocks.
704 * @blocksize: blocksize of journalling device
705 * @returns: a newly created journal_t *
706 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700707 * jbd2_journal_init_dev creates a journal which maps a fixed contiguous
Dave Kleikamp470decc2006-10-11 01:20:57 -0700708 * range of blocks on an arbitrary block device.
709 *
710 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700711journal_t * jbd2_journal_init_dev(struct block_device *bdev,
Dave Kleikamp470decc2006-10-11 01:20:57 -0700712 struct block_device *fs_dev,
Mingming Cao18eba7a2006-10-11 01:21:13 -0700713 unsigned long long start, int len, int blocksize)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700714{
715 journal_t *journal = journal_init_common();
716 struct buffer_head *bh;
717 int n;
718
719 if (!journal)
720 return NULL;
721
722 /* journal descriptor can store up to n blocks -bzzz */
723 journal->j_blocksize = blocksize;
724 n = journal->j_blocksize / sizeof(journal_block_tag_t);
725 journal->j_wbufsize = n;
726 journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
727 if (!journal->j_wbuf) {
728 printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n",
729 __FUNCTION__);
730 kfree(journal);
731 journal = NULL;
Dave Kleikamp5eb30792006-10-17 00:09:35 -0700732 goto out;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700733 }
734 journal->j_dev = bdev;
735 journal->j_fs_dev = fs_dev;
736 journal->j_blk_offset = start;
737 journal->j_maxlen = len;
738
739 bh = __getblk(journal->j_dev, start, journal->j_blocksize);
740 J_ASSERT(bh != NULL);
741 journal->j_sb_buffer = bh;
742 journal->j_superblock = (journal_superblock_t *)bh->b_data;
Dave Kleikamp5eb30792006-10-17 00:09:35 -0700743out:
Dave Kleikamp470decc2006-10-11 01:20:57 -0700744 return journal;
745}
746
747/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700748 * journal_t * jbd2_journal_init_inode () - creates a journal which maps to a inode.
Dave Kleikamp470decc2006-10-11 01:20:57 -0700749 * @inode: An inode to create the journal in
750 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700751 * jbd2_journal_init_inode creates a journal which maps an on-disk inode as
Dave Kleikamp470decc2006-10-11 01:20:57 -0700752 * the journal. The inode must exist already, must support bmap() and
753 * must have all data blocks preallocated.
754 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700755journal_t * jbd2_journal_init_inode (struct inode *inode)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700756{
757 struct buffer_head *bh;
758 journal_t *journal = journal_init_common();
759 int err;
760 int n;
Mingming Cao18eba7a2006-10-11 01:21:13 -0700761 unsigned long long blocknr;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700762
763 if (!journal)
764 return NULL;
765
766 journal->j_dev = journal->j_fs_dev = inode->i_sb->s_bdev;
767 journal->j_inode = inode;
768 jbd_debug(1,
769 "journal %p: inode %s/%ld, size %Ld, bits %d, blksize %ld\n",
770 journal, inode->i_sb->s_id, inode->i_ino,
771 (long long) inode->i_size,
772 inode->i_sb->s_blocksize_bits, inode->i_sb->s_blocksize);
773
774 journal->j_maxlen = inode->i_size >> inode->i_sb->s_blocksize_bits;
775 journal->j_blocksize = inode->i_sb->s_blocksize;
776
777 /* journal descriptor can store up to n blocks -bzzz */
778 n = journal->j_blocksize / sizeof(journal_block_tag_t);
779 journal->j_wbufsize = n;
780 journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
781 if (!journal->j_wbuf) {
782 printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n",
783 __FUNCTION__);
784 kfree(journal);
785 return NULL;
786 }
787
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700788 err = jbd2_journal_bmap(journal, 0, &blocknr);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700789 /* If that failed, give up */
790 if (err) {
791 printk(KERN_ERR "%s: Cannnot locate journal superblock\n",
792 __FUNCTION__);
793 kfree(journal);
794 return NULL;
795 }
796
797 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
798 J_ASSERT(bh != NULL);
799 journal->j_sb_buffer = bh;
800 journal->j_superblock = (journal_superblock_t *)bh->b_data;
801
802 return journal;
803}
804
805/*
806 * If the journal init or create aborts, we need to mark the journal
807 * superblock as being NULL to prevent the journal destroy from writing
808 * back a bogus superblock.
809 */
810static void journal_fail_superblock (journal_t *journal)
811{
812 struct buffer_head *bh = journal->j_sb_buffer;
813 brelse(bh);
814 journal->j_sb_buffer = NULL;
815}
816
817/*
818 * Given a journal_t structure, initialise the various fields for
819 * startup of a new journaling session. We use this both when creating
820 * a journal, and after recovering an old journal to reset it for
821 * subsequent use.
822 */
823
824static int journal_reset(journal_t *journal)
825{
826 journal_superblock_t *sb = journal->j_superblock;
Mingming Cao18eba7a2006-10-11 01:21:13 -0700827 unsigned long long first, last;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700828
829 first = be32_to_cpu(sb->s_first);
830 last = be32_to_cpu(sb->s_maxlen);
831
832 journal->j_first = first;
833 journal->j_last = last;
834
835 journal->j_head = first;
836 journal->j_tail = first;
837 journal->j_free = last - first;
838
839 journal->j_tail_sequence = journal->j_transaction_sequence;
840 journal->j_commit_sequence = journal->j_transaction_sequence - 1;
841 journal->j_commit_request = journal->j_commit_sequence;
842
843 journal->j_max_transaction_buffers = journal->j_maxlen / 4;
844
845 /* Add the dynamic fields and write it to disk. */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700846 jbd2_journal_update_superblock(journal, 1);
Pavel Emelianov97f06782007-05-08 00:30:42 -0700847 return jbd2_journal_start_thread(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700848}
849
850/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700851 * int jbd2_journal_create() - Initialise the new journal file
Dave Kleikamp470decc2006-10-11 01:20:57 -0700852 * @journal: Journal to create. This structure must have been initialised
853 *
854 * Given a journal_t structure which tells us which disk blocks we can
855 * use, create a new journal superblock and initialise all of the
856 * journal fields from scratch.
857 **/
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700858int jbd2_journal_create(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700859{
Mingming Cao18eba7a2006-10-11 01:21:13 -0700860 unsigned long long blocknr;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700861 struct buffer_head *bh;
862 journal_superblock_t *sb;
863 int i, err;
864
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700865 if (journal->j_maxlen < JBD2_MIN_JOURNAL_BLOCKS) {
Dave Kleikamp470decc2006-10-11 01:20:57 -0700866 printk (KERN_ERR "Journal length (%d blocks) too short.\n",
867 journal->j_maxlen);
868 journal_fail_superblock(journal);
869 return -EINVAL;
870 }
871
872 if (journal->j_inode == NULL) {
873 /*
874 * We don't know what block to start at!
875 */
876 printk(KERN_EMERG
877 "%s: creation of journal on external device!\n",
878 __FUNCTION__);
879 BUG();
880 }
881
882 /* Zero out the entire journal on disk. We cannot afford to
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700883 have any blocks on disk beginning with JBD2_MAGIC_NUMBER. */
Dave Kleikamp470decc2006-10-11 01:20:57 -0700884 jbd_debug(1, "JBD: Zeroing out journal blocks...\n");
885 for (i = 0; i < journal->j_maxlen; i++) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700886 err = jbd2_journal_bmap(journal, i, &blocknr);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700887 if (err)
888 return err;
889 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
890 lock_buffer(bh);
891 memset (bh->b_data, 0, journal->j_blocksize);
892 BUFFER_TRACE(bh, "marking dirty");
893 mark_buffer_dirty(bh);
894 BUFFER_TRACE(bh, "marking uptodate");
895 set_buffer_uptodate(bh);
896 unlock_buffer(bh);
897 __brelse(bh);
898 }
899
900 sync_blockdev(journal->j_dev);
901 jbd_debug(1, "JBD: journal cleared.\n");
902
903 /* OK, fill in the initial static fields in the new superblock */
904 sb = journal->j_superblock;
905
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700906 sb->s_header.h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER);
907 sb->s_header.h_blocktype = cpu_to_be32(JBD2_SUPERBLOCK_V2);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700908
909 sb->s_blocksize = cpu_to_be32(journal->j_blocksize);
910 sb->s_maxlen = cpu_to_be32(journal->j_maxlen);
911 sb->s_first = cpu_to_be32(1);
912
913 journal->j_transaction_sequence = 1;
914
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700915 journal->j_flags &= ~JBD2_ABORT;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700916 journal->j_format_version = 2;
917
918 return journal_reset(journal);
919}
920
921/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700922 * void jbd2_journal_update_superblock() - Update journal sb on disk.
Dave Kleikamp470decc2006-10-11 01:20:57 -0700923 * @journal: The journal to update.
924 * @wait: Set to '0' if you don't want to wait for IO completion.
925 *
926 * Update a journal's dynamic superblock fields and write it to disk,
927 * optionally waiting for the IO to complete.
928 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700929void jbd2_journal_update_superblock(journal_t *journal, int wait)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700930{
931 journal_superblock_t *sb = journal->j_superblock;
932 struct buffer_head *bh = journal->j_sb_buffer;
933
934 /*
935 * As a special case, if the on-disk copy is already marked as needing
936 * no recovery (s_start == 0) and there are no outstanding transactions
937 * in the filesystem, then we can safely defer the superblock update
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700938 * until the next commit by setting JBD2_FLUSHED. This avoids
Dave Kleikamp470decc2006-10-11 01:20:57 -0700939 * attempting a write to a potential-readonly device.
940 */
941 if (sb->s_start == 0 && journal->j_tail_sequence ==
942 journal->j_transaction_sequence) {
943 jbd_debug(1,"JBD: Skipping superblock update on recovered sb "
944 "(start %ld, seq %d, errno %d)\n",
945 journal->j_tail, journal->j_tail_sequence,
946 journal->j_errno);
947 goto out;
948 }
949
950 spin_lock(&journal->j_state_lock);
951 jbd_debug(1,"JBD: updating superblock (start %ld, seq %d, errno %d)\n",
952 journal->j_tail, journal->j_tail_sequence, journal->j_errno);
953
954 sb->s_sequence = cpu_to_be32(journal->j_tail_sequence);
955 sb->s_start = cpu_to_be32(journal->j_tail);
956 sb->s_errno = cpu_to_be32(journal->j_errno);
957 spin_unlock(&journal->j_state_lock);
958
959 BUFFER_TRACE(bh, "marking dirty");
960 mark_buffer_dirty(bh);
961 if (wait)
962 sync_dirty_buffer(bh);
963 else
964 ll_rw_block(SWRITE, 1, &bh);
965
966out:
967 /* If we have just flushed the log (by marking s_start==0), then
968 * any future commit will have to be careful to update the
969 * superblock again to re-record the true start of the log. */
970
971 spin_lock(&journal->j_state_lock);
972 if (sb->s_start)
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700973 journal->j_flags &= ~JBD2_FLUSHED;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700974 else
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700975 journal->j_flags |= JBD2_FLUSHED;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700976 spin_unlock(&journal->j_state_lock);
977}
978
979/*
980 * Read the superblock for a given journal, performing initial
981 * validation of the format.
982 */
983
984static int journal_get_superblock(journal_t *journal)
985{
986 struct buffer_head *bh;
987 journal_superblock_t *sb;
988 int err = -EIO;
989
990 bh = journal->j_sb_buffer;
991
992 J_ASSERT(bh != NULL);
993 if (!buffer_uptodate(bh)) {
994 ll_rw_block(READ, 1, &bh);
995 wait_on_buffer(bh);
996 if (!buffer_uptodate(bh)) {
997 printk (KERN_ERR
998 "JBD: IO error reading journal superblock\n");
999 goto out;
1000 }
1001 }
1002
1003 sb = journal->j_superblock;
1004
1005 err = -EINVAL;
1006
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001007 if (sb->s_header.h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER) ||
Dave Kleikamp470decc2006-10-11 01:20:57 -07001008 sb->s_blocksize != cpu_to_be32(journal->j_blocksize)) {
1009 printk(KERN_WARNING "JBD: no valid journal superblock found\n");
1010 goto out;
1011 }
1012
1013 switch(be32_to_cpu(sb->s_header.h_blocktype)) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001014 case JBD2_SUPERBLOCK_V1:
Dave Kleikamp470decc2006-10-11 01:20:57 -07001015 journal->j_format_version = 1;
1016 break;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001017 case JBD2_SUPERBLOCK_V2:
Dave Kleikamp470decc2006-10-11 01:20:57 -07001018 journal->j_format_version = 2;
1019 break;
1020 default:
1021 printk(KERN_WARNING "JBD: unrecognised superblock format ID\n");
1022 goto out;
1023 }
1024
1025 if (be32_to_cpu(sb->s_maxlen) < journal->j_maxlen)
1026 journal->j_maxlen = be32_to_cpu(sb->s_maxlen);
1027 else if (be32_to_cpu(sb->s_maxlen) > journal->j_maxlen) {
1028 printk (KERN_WARNING "JBD: journal file too short\n");
1029 goto out;
1030 }
1031
1032 return 0;
1033
1034out:
1035 journal_fail_superblock(journal);
1036 return err;
1037}
1038
1039/*
1040 * Load the on-disk journal superblock and read the key fields into the
1041 * journal_t.
1042 */
1043
1044static int load_superblock(journal_t *journal)
1045{
1046 int err;
1047 journal_superblock_t *sb;
1048
1049 err = journal_get_superblock(journal);
1050 if (err)
1051 return err;
1052
1053 sb = journal->j_superblock;
1054
1055 journal->j_tail_sequence = be32_to_cpu(sb->s_sequence);
1056 journal->j_tail = be32_to_cpu(sb->s_start);
1057 journal->j_first = be32_to_cpu(sb->s_first);
1058 journal->j_last = be32_to_cpu(sb->s_maxlen);
1059 journal->j_errno = be32_to_cpu(sb->s_errno);
1060
1061 return 0;
1062}
1063
1064
1065/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001066 * int jbd2_journal_load() - Read journal from disk.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001067 * @journal: Journal to act on.
1068 *
1069 * Given a journal_t structure which tells us which disk blocks contain
1070 * a journal, read the journal from disk to initialise the in-memory
1071 * structures.
1072 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001073int jbd2_journal_load(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001074{
1075 int err;
1076 journal_superblock_t *sb;
1077
1078 err = load_superblock(journal);
1079 if (err)
1080 return err;
1081
1082 sb = journal->j_superblock;
1083 /* If this is a V2 superblock, then we have to check the
1084 * features flags on it. */
1085
1086 if (journal->j_format_version >= 2) {
1087 if ((sb->s_feature_ro_compat &
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001088 ~cpu_to_be32(JBD2_KNOWN_ROCOMPAT_FEATURES)) ||
Dave Kleikamp470decc2006-10-11 01:20:57 -07001089 (sb->s_feature_incompat &
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001090 ~cpu_to_be32(JBD2_KNOWN_INCOMPAT_FEATURES))) {
Dave Kleikamp470decc2006-10-11 01:20:57 -07001091 printk (KERN_WARNING
1092 "JBD: Unrecognised features on journal\n");
1093 return -EINVAL;
1094 }
1095 }
1096
Dave Kleikamp470decc2006-10-11 01:20:57 -07001097 /* Let the recovery code check whether it needs to recover any
1098 * data from the journal. */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001099 if (jbd2_journal_recover(journal))
Dave Kleikamp470decc2006-10-11 01:20:57 -07001100 goto recovery_error;
1101
1102 /* OK, we've finished with the dynamic journal bits:
1103 * reinitialise the dynamic contents of the superblock in memory
1104 * and reset them on disk. */
1105 if (journal_reset(journal))
1106 goto recovery_error;
1107
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001108 journal->j_flags &= ~JBD2_ABORT;
1109 journal->j_flags |= JBD2_LOADED;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001110 return 0;
1111
1112recovery_error:
1113 printk (KERN_WARNING "JBD: recovery failed\n");
1114 return -EIO;
1115}
1116
1117/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001118 * void jbd2_journal_destroy() - Release a journal_t structure.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001119 * @journal: Journal to act on.
1120 *
1121 * Release a journal_t structure once it is no longer in use by the
1122 * journaled object.
1123 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001124void jbd2_journal_destroy(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001125{
1126 /* Wait for the commit thread to wake up and die. */
1127 journal_kill_thread(journal);
1128
1129 /* Force a final log commit */
1130 if (journal->j_running_transaction)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001131 jbd2_journal_commit_transaction(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001132
1133 /* Force any old transactions to disk */
1134
1135 /* Totally anal locking here... */
1136 spin_lock(&journal->j_list_lock);
1137 while (journal->j_checkpoint_transactions != NULL) {
1138 spin_unlock(&journal->j_list_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001139 jbd2_log_do_checkpoint(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001140 spin_lock(&journal->j_list_lock);
1141 }
1142
1143 J_ASSERT(journal->j_running_transaction == NULL);
1144 J_ASSERT(journal->j_committing_transaction == NULL);
1145 J_ASSERT(journal->j_checkpoint_transactions == NULL);
1146 spin_unlock(&journal->j_list_lock);
1147
1148 /* We can now mark the journal as empty. */
1149 journal->j_tail = 0;
1150 journal->j_tail_sequence = ++journal->j_transaction_sequence;
1151 if (journal->j_sb_buffer) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001152 jbd2_journal_update_superblock(journal, 1);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001153 brelse(journal->j_sb_buffer);
1154 }
1155
1156 if (journal->j_inode)
1157 iput(journal->j_inode);
1158 if (journal->j_revoke)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001159 jbd2_journal_destroy_revoke(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001160 kfree(journal->j_wbuf);
1161 kfree(journal);
1162}
1163
1164
1165/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001166 *int jbd2_journal_check_used_features () - Check if features specified are used.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001167 * @journal: Journal to check.
1168 * @compat: bitmask of compatible features
1169 * @ro: bitmask of features that force read-only mount
1170 * @incompat: bitmask of incompatible features
1171 *
1172 * Check whether the journal uses all of a given set of
1173 * features. Return true (non-zero) if it does.
1174 **/
1175
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001176int jbd2_journal_check_used_features (journal_t *journal, unsigned long compat,
Dave Kleikamp470decc2006-10-11 01:20:57 -07001177 unsigned long ro, unsigned long incompat)
1178{
1179 journal_superblock_t *sb;
1180
1181 if (!compat && !ro && !incompat)
1182 return 1;
1183 if (journal->j_format_version == 1)
1184 return 0;
1185
1186 sb = journal->j_superblock;
1187
1188 if (((be32_to_cpu(sb->s_feature_compat) & compat) == compat) &&
1189 ((be32_to_cpu(sb->s_feature_ro_compat) & ro) == ro) &&
1190 ((be32_to_cpu(sb->s_feature_incompat) & incompat) == incompat))
1191 return 1;
1192
1193 return 0;
1194}
1195
1196/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001197 * int jbd2_journal_check_available_features() - Check feature set in journalling layer
Dave Kleikamp470decc2006-10-11 01:20:57 -07001198 * @journal: Journal to check.
1199 * @compat: bitmask of compatible features
1200 * @ro: bitmask of features that force read-only mount
1201 * @incompat: bitmask of incompatible features
1202 *
1203 * Check whether the journaling code supports the use of
1204 * all of a given set of features on this journal. Return true
1205 * (non-zero) if it can. */
1206
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001207int jbd2_journal_check_available_features (journal_t *journal, unsigned long compat,
Dave Kleikamp470decc2006-10-11 01:20:57 -07001208 unsigned long ro, unsigned long incompat)
1209{
1210 journal_superblock_t *sb;
1211
1212 if (!compat && !ro && !incompat)
1213 return 1;
1214
1215 sb = journal->j_superblock;
1216
1217 /* We can support any known requested features iff the
1218 * superblock is in version 2. Otherwise we fail to support any
1219 * extended sb features. */
1220
1221 if (journal->j_format_version != 2)
1222 return 0;
1223
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001224 if ((compat & JBD2_KNOWN_COMPAT_FEATURES) == compat &&
1225 (ro & JBD2_KNOWN_ROCOMPAT_FEATURES) == ro &&
1226 (incompat & JBD2_KNOWN_INCOMPAT_FEATURES) == incompat)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001227 return 1;
1228
1229 return 0;
1230}
1231
1232/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001233 * int jbd2_journal_set_features () - Mark a given journal feature in the superblock
Dave Kleikamp470decc2006-10-11 01:20:57 -07001234 * @journal: Journal to act on.
1235 * @compat: bitmask of compatible features
1236 * @ro: bitmask of features that force read-only mount
1237 * @incompat: bitmask of incompatible features
1238 *
1239 * Mark a given journal feature as present on the
1240 * superblock. Returns true if the requested features could be set.
1241 *
1242 */
1243
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001244int jbd2_journal_set_features (journal_t *journal, unsigned long compat,
Dave Kleikamp470decc2006-10-11 01:20:57 -07001245 unsigned long ro, unsigned long incompat)
1246{
1247 journal_superblock_t *sb;
1248
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001249 if (jbd2_journal_check_used_features(journal, compat, ro, incompat))
Dave Kleikamp470decc2006-10-11 01:20:57 -07001250 return 1;
1251
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001252 if (!jbd2_journal_check_available_features(journal, compat, ro, incompat))
Dave Kleikamp470decc2006-10-11 01:20:57 -07001253 return 0;
1254
1255 jbd_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n",
1256 compat, ro, incompat);
1257
1258 sb = journal->j_superblock;
1259
1260 sb->s_feature_compat |= cpu_to_be32(compat);
1261 sb->s_feature_ro_compat |= cpu_to_be32(ro);
1262 sb->s_feature_incompat |= cpu_to_be32(incompat);
1263
1264 return 1;
1265}
1266
1267
1268/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001269 * int jbd2_journal_update_format () - Update on-disk journal structure.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001270 * @journal: Journal to act on.
1271 *
1272 * Given an initialised but unloaded journal struct, poke about in the
1273 * on-disk structure to update it to the most recent supported version.
1274 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001275int jbd2_journal_update_format (journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001276{
1277 journal_superblock_t *sb;
1278 int err;
1279
1280 err = journal_get_superblock(journal);
1281 if (err)
1282 return err;
1283
1284 sb = journal->j_superblock;
1285
1286 switch (be32_to_cpu(sb->s_header.h_blocktype)) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001287 case JBD2_SUPERBLOCK_V2:
Dave Kleikamp470decc2006-10-11 01:20:57 -07001288 return 0;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001289 case JBD2_SUPERBLOCK_V1:
Dave Kleikamp470decc2006-10-11 01:20:57 -07001290 return journal_convert_superblock_v1(journal, sb);
1291 default:
1292 break;
1293 }
1294 return -EINVAL;
1295}
1296
1297static int journal_convert_superblock_v1(journal_t *journal,
1298 journal_superblock_t *sb)
1299{
1300 int offset, blocksize;
1301 struct buffer_head *bh;
1302
1303 printk(KERN_WARNING
1304 "JBD: Converting superblock from version 1 to 2.\n");
1305
1306 /* Pre-initialise new fields to zero */
1307 offset = ((char *) &(sb->s_feature_compat)) - ((char *) sb);
1308 blocksize = be32_to_cpu(sb->s_blocksize);
1309 memset(&sb->s_feature_compat, 0, blocksize-offset);
1310
1311 sb->s_nr_users = cpu_to_be32(1);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001312 sb->s_header.h_blocktype = cpu_to_be32(JBD2_SUPERBLOCK_V2);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001313 journal->j_format_version = 2;
1314
1315 bh = journal->j_sb_buffer;
1316 BUFFER_TRACE(bh, "marking dirty");
1317 mark_buffer_dirty(bh);
1318 sync_dirty_buffer(bh);
1319 return 0;
1320}
1321
1322
1323/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001324 * int jbd2_journal_flush () - Flush journal
Dave Kleikamp470decc2006-10-11 01:20:57 -07001325 * @journal: Journal to act on.
1326 *
1327 * Flush all data for a given journal to disk and empty the journal.
1328 * Filesystems can use this when remounting readonly to ensure that
1329 * recovery does not need to happen on remount.
1330 */
1331
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001332int jbd2_journal_flush(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001333{
1334 int err = 0;
1335 transaction_t *transaction = NULL;
1336 unsigned long old_tail;
1337
1338 spin_lock(&journal->j_state_lock);
1339
1340 /* Force everything buffered to the log... */
1341 if (journal->j_running_transaction) {
1342 transaction = journal->j_running_transaction;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001343 __jbd2_log_start_commit(journal, transaction->t_tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001344 } else if (journal->j_committing_transaction)
1345 transaction = journal->j_committing_transaction;
1346
1347 /* Wait for the log commit to complete... */
1348 if (transaction) {
1349 tid_t tid = transaction->t_tid;
1350
1351 spin_unlock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001352 jbd2_log_wait_commit(journal, tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001353 } else {
1354 spin_unlock(&journal->j_state_lock);
1355 }
1356
1357 /* ...and flush everything in the log out to disk. */
1358 spin_lock(&journal->j_list_lock);
1359 while (!err && journal->j_checkpoint_transactions != NULL) {
1360 spin_unlock(&journal->j_list_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001361 err = jbd2_log_do_checkpoint(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001362 spin_lock(&journal->j_list_lock);
1363 }
1364 spin_unlock(&journal->j_list_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001365 jbd2_cleanup_journal_tail(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001366
1367 /* Finally, mark the journal as really needing no recovery.
1368 * This sets s_start==0 in the underlying superblock, which is
1369 * the magic code for a fully-recovered superblock. Any future
1370 * commits of data to the journal will restore the current
1371 * s_start value. */
1372 spin_lock(&journal->j_state_lock);
1373 old_tail = journal->j_tail;
1374 journal->j_tail = 0;
1375 spin_unlock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001376 jbd2_journal_update_superblock(journal, 1);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001377 spin_lock(&journal->j_state_lock);
1378 journal->j_tail = old_tail;
1379
1380 J_ASSERT(!journal->j_running_transaction);
1381 J_ASSERT(!journal->j_committing_transaction);
1382 J_ASSERT(!journal->j_checkpoint_transactions);
1383 J_ASSERT(journal->j_head == journal->j_tail);
1384 J_ASSERT(journal->j_tail_sequence == journal->j_transaction_sequence);
1385 spin_unlock(&journal->j_state_lock);
1386 return err;
1387}
1388
1389/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001390 * int jbd2_journal_wipe() - Wipe journal contents
Dave Kleikamp470decc2006-10-11 01:20:57 -07001391 * @journal: Journal to act on.
1392 * @write: flag (see below)
1393 *
1394 * Wipe out all of the contents of a journal, safely. This will produce
1395 * a warning if the journal contains any valid recovery information.
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001396 * Must be called between journal_init_*() and jbd2_journal_load().
Dave Kleikamp470decc2006-10-11 01:20:57 -07001397 *
1398 * If 'write' is non-zero, then we wipe out the journal on disk; otherwise
1399 * we merely suppress recovery.
1400 */
1401
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001402int jbd2_journal_wipe(journal_t *journal, int write)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001403{
1404 journal_superblock_t *sb;
1405 int err = 0;
1406
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001407 J_ASSERT (!(journal->j_flags & JBD2_LOADED));
Dave Kleikamp470decc2006-10-11 01:20:57 -07001408
1409 err = load_superblock(journal);
1410 if (err)
1411 return err;
1412
1413 sb = journal->j_superblock;
1414
1415 if (!journal->j_tail)
1416 goto no_recovery;
1417
1418 printk (KERN_WARNING "JBD: %s recovery information on journal\n",
1419 write ? "Clearing" : "Ignoring");
1420
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001421 err = jbd2_journal_skip_recovery(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001422 if (write)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001423 jbd2_journal_update_superblock(journal, 1);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001424
1425 no_recovery:
1426 return err;
1427}
1428
1429/*
1430 * journal_dev_name: format a character string to describe on what
1431 * device this journal is present.
1432 */
1433
1434static const char *journal_dev_name(journal_t *journal, char *buffer)
1435{
1436 struct block_device *bdev;
1437
1438 if (journal->j_inode)
1439 bdev = journal->j_inode->i_sb->s_bdev;
1440 else
1441 bdev = journal->j_dev;
1442
1443 return bdevname(bdev, buffer);
1444}
1445
1446/*
1447 * Journal abort has very specific semantics, which we describe
1448 * for journal abort.
1449 *
1450 * Two internal function, which provide abort to te jbd layer
1451 * itself are here.
1452 */
1453
1454/*
1455 * Quick version for internal journal use (doesn't lock the journal).
1456 * Aborts hard --- we mark the abort as occurred, but do _nothing_ else,
1457 * and don't attempt to make any other journal updates.
1458 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001459void __jbd2_journal_abort_hard(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001460{
1461 transaction_t *transaction;
1462 char b[BDEVNAME_SIZE];
1463
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001464 if (journal->j_flags & JBD2_ABORT)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001465 return;
1466
1467 printk(KERN_ERR "Aborting journal on device %s.\n",
1468 journal_dev_name(journal, b));
1469
1470 spin_lock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001471 journal->j_flags |= JBD2_ABORT;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001472 transaction = journal->j_running_transaction;
1473 if (transaction)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001474 __jbd2_log_start_commit(journal, transaction->t_tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001475 spin_unlock(&journal->j_state_lock);
1476}
1477
1478/* Soft abort: record the abort error status in the journal superblock,
1479 * but don't do any other IO. */
1480static void __journal_abort_soft (journal_t *journal, int errno)
1481{
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001482 if (journal->j_flags & JBD2_ABORT)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001483 return;
1484
1485 if (!journal->j_errno)
1486 journal->j_errno = errno;
1487
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001488 __jbd2_journal_abort_hard(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001489
1490 if (errno)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001491 jbd2_journal_update_superblock(journal, 1);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001492}
1493
1494/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001495 * void jbd2_journal_abort () - Shutdown the journal immediately.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001496 * @journal: the journal to shutdown.
1497 * @errno: an error number to record in the journal indicating
1498 * the reason for the shutdown.
1499 *
1500 * Perform a complete, immediate shutdown of the ENTIRE
1501 * journal (not of a single transaction). This operation cannot be
1502 * undone without closing and reopening the journal.
1503 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001504 * The jbd2_journal_abort function is intended to support higher level error
Dave Kleikamp470decc2006-10-11 01:20:57 -07001505 * recovery mechanisms such as the ext2/ext3 remount-readonly error
1506 * mode.
1507 *
1508 * Journal abort has very specific semantics. Any existing dirty,
1509 * unjournaled buffers in the main filesystem will still be written to
1510 * disk by bdflush, but the journaling mechanism will be suspended
1511 * immediately and no further transaction commits will be honoured.
1512 *
1513 * Any dirty, journaled buffers will be written back to disk without
1514 * hitting the journal. Atomicity cannot be guaranteed on an aborted
1515 * filesystem, but we _do_ attempt to leave as much data as possible
1516 * behind for fsck to use for cleanup.
1517 *
1518 * Any attempt to get a new transaction handle on a journal which is in
1519 * ABORT state will just result in an -EROFS error return. A
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001520 * jbd2_journal_stop on an existing handle will return -EIO if we have
Dave Kleikamp470decc2006-10-11 01:20:57 -07001521 * entered abort state during the update.
1522 *
1523 * Recursive transactions are not disturbed by journal abort until the
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001524 * final jbd2_journal_stop, which will receive the -EIO error.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001525 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001526 * Finally, the jbd2_journal_abort call allows the caller to supply an errno
Dave Kleikamp470decc2006-10-11 01:20:57 -07001527 * which will be recorded (if possible) in the journal superblock. This
1528 * allows a client to record failure conditions in the middle of a
1529 * transaction without having to complete the transaction to record the
1530 * failure to disk. ext3_error, for example, now uses this
1531 * functionality.
1532 *
1533 * Errors which originate from within the journaling layer will NOT
1534 * supply an errno; a null errno implies that absolutely no further
1535 * writes are done to the journal (unless there are any already in
1536 * progress).
1537 *
1538 */
1539
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001540void jbd2_journal_abort(journal_t *journal, int errno)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001541{
1542 __journal_abort_soft(journal, errno);
1543}
1544
1545/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001546 * int jbd2_journal_errno () - returns the journal's error state.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001547 * @journal: journal to examine.
1548 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001549 * This is the errno numbet set with jbd2_journal_abort(), the last
Dave Kleikamp470decc2006-10-11 01:20:57 -07001550 * time the journal was mounted - if the journal was stopped
1551 * without calling abort this will be 0.
1552 *
1553 * If the journal has been aborted on this mount time -EROFS will
1554 * be returned.
1555 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001556int jbd2_journal_errno(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001557{
1558 int err;
1559
1560 spin_lock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001561 if (journal->j_flags & JBD2_ABORT)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001562 err = -EROFS;
1563 else
1564 err = journal->j_errno;
1565 spin_unlock(&journal->j_state_lock);
1566 return err;
1567}
1568
1569/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001570 * int jbd2_journal_clear_err () - clears the journal's error state
Dave Kleikamp470decc2006-10-11 01:20:57 -07001571 * @journal: journal to act on.
1572 *
1573 * An error must be cleared or Acked to take a FS out of readonly
1574 * mode.
1575 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001576int jbd2_journal_clear_err(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001577{
1578 int err = 0;
1579
1580 spin_lock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001581 if (journal->j_flags & JBD2_ABORT)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001582 err = -EROFS;
1583 else
1584 journal->j_errno = 0;
1585 spin_unlock(&journal->j_state_lock);
1586 return err;
1587}
1588
1589/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001590 * void jbd2_journal_ack_err() - Ack journal err.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001591 * @journal: journal to act on.
1592 *
1593 * An error must be cleared or Acked to take a FS out of readonly
1594 * mode.
1595 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001596void jbd2_journal_ack_err(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001597{
1598 spin_lock(&journal->j_state_lock);
1599 if (journal->j_errno)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001600 journal->j_flags |= JBD2_ACK_ERR;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001601 spin_unlock(&journal->j_state_lock);
1602}
1603
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001604int jbd2_journal_blocks_per_page(struct inode *inode)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001605{
1606 return 1 << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
1607}
1608
1609/*
Zach Brownb517bea2006-10-11 01:21:08 -07001610 * helper functions to deal with 32 or 64bit block numbers.
1611 */
1612size_t journal_tag_bytes(journal_t *journal)
1613{
1614 if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT))
Mingming Caocd02ff02007-10-16 18:38:25 -04001615 return JBD2_TAG_SIZE64;
Zach Brownb517bea2006-10-11 01:21:08 -07001616 else
Mingming Caocd02ff02007-10-16 18:38:25 -04001617 return JBD2_TAG_SIZE32;
Zach Brownb517bea2006-10-11 01:21:08 -07001618}
1619
1620/*
Dave Kleikamp470decc2006-10-11 01:20:57 -07001621 * Journal_head storage management
1622 */
Christoph Lametere18b8902006-12-06 20:33:20 -08001623static struct kmem_cache *jbd2_journal_head_cache;
Jose R. Santose23291b2007-07-18 08:57:06 -04001624#ifdef CONFIG_JBD2_DEBUG
Dave Kleikamp470decc2006-10-11 01:20:57 -07001625static atomic_t nr_journal_heads = ATOMIC_INIT(0);
1626#endif
1627
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001628static int journal_init_jbd2_journal_head_cache(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001629{
1630 int retval;
1631
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001632 J_ASSERT(jbd2_journal_head_cache == 0);
Johann Lombardia920e942006-10-11 01:21:00 -07001633 jbd2_journal_head_cache = kmem_cache_create("jbd2_journal_head",
Dave Kleikamp470decc2006-10-11 01:20:57 -07001634 sizeof(struct journal_head),
1635 0, /* offset */
1636 0, /* flags */
Paul Mundt20c2df82007-07-20 10:11:58 +09001637 NULL); /* ctor */
Dave Kleikamp470decc2006-10-11 01:20:57 -07001638 retval = 0;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001639 if (jbd2_journal_head_cache == 0) {
Dave Kleikamp470decc2006-10-11 01:20:57 -07001640 retval = -ENOMEM;
1641 printk(KERN_EMERG "JBD: no memory for journal_head cache\n");
1642 }
1643 return retval;
1644}
1645
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001646static void jbd2_journal_destroy_jbd2_journal_head_cache(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001647{
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001648 J_ASSERT(jbd2_journal_head_cache != NULL);
1649 kmem_cache_destroy(jbd2_journal_head_cache);
1650 jbd2_journal_head_cache = NULL;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001651}
1652
1653/*
1654 * journal_head splicing and dicing
1655 */
1656static struct journal_head *journal_alloc_journal_head(void)
1657{
1658 struct journal_head *ret;
1659 static unsigned long last_warning;
1660
Jose R. Santose23291b2007-07-18 08:57:06 -04001661#ifdef CONFIG_JBD2_DEBUG
Dave Kleikamp470decc2006-10-11 01:20:57 -07001662 atomic_inc(&nr_journal_heads);
1663#endif
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001664 ret = kmem_cache_alloc(jbd2_journal_head_cache, GFP_NOFS);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001665 if (ret == 0) {
1666 jbd_debug(1, "out of memory for journal_head\n");
1667 if (time_after(jiffies, last_warning + 5*HZ)) {
1668 printk(KERN_NOTICE "ENOMEM in %s, retrying.\n",
1669 __FUNCTION__);
1670 last_warning = jiffies;
1671 }
1672 while (ret == 0) {
1673 yield();
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001674 ret = kmem_cache_alloc(jbd2_journal_head_cache, GFP_NOFS);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001675 }
1676 }
1677 return ret;
1678}
1679
1680static void journal_free_journal_head(struct journal_head *jh)
1681{
Jose R. Santose23291b2007-07-18 08:57:06 -04001682#ifdef CONFIG_JBD2_DEBUG
Dave Kleikamp470decc2006-10-11 01:20:57 -07001683 atomic_dec(&nr_journal_heads);
Mingming Caocd02ff02007-10-16 18:38:25 -04001684 memset(jh, JBD2_POISON_FREE, sizeof(*jh));
Dave Kleikamp470decc2006-10-11 01:20:57 -07001685#endif
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001686 kmem_cache_free(jbd2_journal_head_cache, jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001687}
1688
1689/*
1690 * A journal_head is attached to a buffer_head whenever JBD has an
1691 * interest in the buffer.
1692 *
1693 * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit
1694 * is set. This bit is tested in core kernel code where we need to take
1695 * JBD-specific actions. Testing the zeroness of ->b_private is not reliable
1696 * there.
1697 *
1698 * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one.
1699 *
1700 * When a buffer has its BH_JBD bit set it is immune from being released by
1701 * core kernel code, mainly via ->b_count.
1702 *
1703 * A journal_head may be detached from its buffer_head when the journal_head's
1704 * b_transaction, b_cp_transaction and b_next_transaction pointers are NULL.
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001705 * Various places in JBD call jbd2_journal_remove_journal_head() to indicate that the
Dave Kleikamp470decc2006-10-11 01:20:57 -07001706 * journal_head can be dropped if needed.
1707 *
1708 * Various places in the kernel want to attach a journal_head to a buffer_head
1709 * _before_ attaching the journal_head to a transaction. To protect the
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001710 * journal_head in this situation, jbd2_journal_add_journal_head elevates the
Dave Kleikamp470decc2006-10-11 01:20:57 -07001711 * journal_head's b_jcount refcount by one. The caller must call
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001712 * jbd2_journal_put_journal_head() to undo this.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001713 *
1714 * So the typical usage would be:
1715 *
1716 * (Attach a journal_head if needed. Increments b_jcount)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001717 * struct journal_head *jh = jbd2_journal_add_journal_head(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001718 * ...
1719 * jh->b_transaction = xxx;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001720 * jbd2_journal_put_journal_head(jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001721 *
1722 * Now, the journal_head's b_jcount is zero, but it is safe from being released
1723 * because it has a non-zero b_transaction.
1724 */
1725
1726/*
1727 * Give a buffer_head a journal_head.
1728 *
1729 * Doesn't need the journal lock.
1730 * May sleep.
1731 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001732struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001733{
1734 struct journal_head *jh;
1735 struct journal_head *new_jh = NULL;
1736
1737repeat:
1738 if (!buffer_jbd(bh)) {
1739 new_jh = journal_alloc_journal_head();
1740 memset(new_jh, 0, sizeof(*new_jh));
1741 }
1742
1743 jbd_lock_bh_journal_head(bh);
1744 if (buffer_jbd(bh)) {
1745 jh = bh2jh(bh);
1746 } else {
1747 J_ASSERT_BH(bh,
1748 (atomic_read(&bh->b_count) > 0) ||
1749 (bh->b_page && bh->b_page->mapping));
1750
1751 if (!new_jh) {
1752 jbd_unlock_bh_journal_head(bh);
1753 goto repeat;
1754 }
1755
1756 jh = new_jh;
1757 new_jh = NULL; /* We consumed it */
1758 set_buffer_jbd(bh);
1759 bh->b_private = jh;
1760 jh->b_bh = bh;
1761 get_bh(bh);
1762 BUFFER_TRACE(bh, "added journal_head");
1763 }
1764 jh->b_jcount++;
1765 jbd_unlock_bh_journal_head(bh);
1766 if (new_jh)
1767 journal_free_journal_head(new_jh);
1768 return bh->b_private;
1769}
1770
1771/*
1772 * Grab a ref against this buffer_head's journal_head. If it ended up not
1773 * having a journal_head, return NULL
1774 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001775struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001776{
1777 struct journal_head *jh = NULL;
1778
1779 jbd_lock_bh_journal_head(bh);
1780 if (buffer_jbd(bh)) {
1781 jh = bh2jh(bh);
1782 jh->b_jcount++;
1783 }
1784 jbd_unlock_bh_journal_head(bh);
1785 return jh;
1786}
1787
1788static void __journal_remove_journal_head(struct buffer_head *bh)
1789{
1790 struct journal_head *jh = bh2jh(bh);
1791
1792 J_ASSERT_JH(jh, jh->b_jcount >= 0);
1793
1794 get_bh(bh);
1795 if (jh->b_jcount == 0) {
1796 if (jh->b_transaction == NULL &&
1797 jh->b_next_transaction == NULL &&
1798 jh->b_cp_transaction == NULL) {
1799 J_ASSERT_JH(jh, jh->b_jlist == BJ_None);
1800 J_ASSERT_BH(bh, buffer_jbd(bh));
1801 J_ASSERT_BH(bh, jh2bh(jh) == bh);
1802 BUFFER_TRACE(bh, "remove journal_head");
1803 if (jh->b_frozen_data) {
1804 printk(KERN_WARNING "%s: freeing "
1805 "b_frozen_data\n",
1806 __FUNCTION__);
Mingming Caoaf1e76d2007-10-16 18:38:25 -04001807 jbd2_free(jh->b_frozen_data, bh->b_size);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001808 }
1809 if (jh->b_committed_data) {
1810 printk(KERN_WARNING "%s: freeing "
1811 "b_committed_data\n",
1812 __FUNCTION__);
Mingming Caoaf1e76d2007-10-16 18:38:25 -04001813 jbd2_free(jh->b_committed_data, bh->b_size);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001814 }
1815 bh->b_private = NULL;
1816 jh->b_bh = NULL; /* debug, really */
1817 clear_buffer_jbd(bh);
1818 __brelse(bh);
1819 journal_free_journal_head(jh);
1820 } else {
1821 BUFFER_TRACE(bh, "journal_head was locked");
1822 }
1823 }
1824}
1825
1826/*
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001827 * jbd2_journal_remove_journal_head(): if the buffer isn't attached to a transaction
Dave Kleikamp470decc2006-10-11 01:20:57 -07001828 * and has a zero b_jcount then remove and release its journal_head. If we did
1829 * see that the buffer is not used by any transaction we also "logically"
1830 * decrement ->b_count.
1831 *
1832 * We in fact take an additional increment on ->b_count as a convenience,
1833 * because the caller usually wants to do additional things with the bh
1834 * after calling here.
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001835 * The caller of jbd2_journal_remove_journal_head() *must* run __brelse(bh) at some
Dave Kleikamp470decc2006-10-11 01:20:57 -07001836 * time. Once the caller has run __brelse(), the buffer is eligible for
1837 * reaping by try_to_free_buffers().
1838 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001839void jbd2_journal_remove_journal_head(struct buffer_head *bh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001840{
1841 jbd_lock_bh_journal_head(bh);
1842 __journal_remove_journal_head(bh);
1843 jbd_unlock_bh_journal_head(bh);
1844}
1845
1846/*
1847 * Drop a reference on the passed journal_head. If it fell to zero then try to
1848 * release the journal_head from the buffer_head.
1849 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001850void jbd2_journal_put_journal_head(struct journal_head *jh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001851{
1852 struct buffer_head *bh = jh2bh(jh);
1853
1854 jbd_lock_bh_journal_head(bh);
1855 J_ASSERT_JH(jh, jh->b_jcount > 0);
1856 --jh->b_jcount;
1857 if (!jh->b_jcount && !jh->b_transaction) {
1858 __journal_remove_journal_head(bh);
1859 __brelse(bh);
1860 }
1861 jbd_unlock_bh_journal_head(bh);
1862}
1863
1864/*
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04001865 * debugfs tunables
Dave Kleikamp470decc2006-10-11 01:20:57 -07001866 */
Jose R. Santos6f38c742007-10-16 18:38:25 -04001867#ifdef CONFIG_JBD2_DEBUG
1868u8 jbd2_journal_enable_debug __read_mostly;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001869EXPORT_SYMBOL(jbd2_journal_enable_debug);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001870
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04001871#define JBD2_DEBUG_NAME "jbd2-debug"
Dave Kleikamp470decc2006-10-11 01:20:57 -07001872
Jose R. Santos6f38c742007-10-16 18:38:25 -04001873static struct dentry *jbd2_debugfs_dir;
1874static struct dentry *jbd2_debug;
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04001875
1876static void __init jbd2_create_debugfs_entry(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001877{
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04001878 jbd2_debugfs_dir = debugfs_create_dir("jbd2", NULL);
1879 if (jbd2_debugfs_dir)
1880 jbd2_debug = debugfs_create_u8(JBD2_DEBUG_NAME, S_IRUGO,
1881 jbd2_debugfs_dir,
1882 &jbd2_journal_enable_debug);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001883}
1884
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04001885static void __exit jbd2_remove_debugfs_entry(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001886{
Jose R. Santos6f38c742007-10-16 18:38:25 -04001887 debugfs_remove(jbd2_debug);
1888 debugfs_remove(jbd2_debugfs_dir);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001889}
1890
1891#else
1892
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04001893static void __init jbd2_create_debugfs_entry(void)
1894{
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04001895}
1896
1897static void __exit jbd2_remove_debugfs_entry(void)
1898{
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04001899}
Dave Kleikamp470decc2006-10-11 01:20:57 -07001900
1901#endif
1902
Christoph Lametere18b8902006-12-06 20:33:20 -08001903struct kmem_cache *jbd2_handle_cache;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001904
1905static int __init journal_init_handle_cache(void)
1906{
Johann Lombardia920e942006-10-11 01:21:00 -07001907 jbd2_handle_cache = kmem_cache_create("jbd2_journal_handle",
Dave Kleikamp470decc2006-10-11 01:20:57 -07001908 sizeof(handle_t),
1909 0, /* offset */
1910 0, /* flags */
Paul Mundt20c2df82007-07-20 10:11:58 +09001911 NULL); /* ctor */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001912 if (jbd2_handle_cache == NULL) {
Dave Kleikamp470decc2006-10-11 01:20:57 -07001913 printk(KERN_EMERG "JBD: failed to create handle cache\n");
1914 return -ENOMEM;
1915 }
1916 return 0;
1917}
1918
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001919static void jbd2_journal_destroy_handle_cache(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001920{
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001921 if (jbd2_handle_cache)
1922 kmem_cache_destroy(jbd2_handle_cache);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001923}
1924
1925/*
1926 * Module startup and shutdown
1927 */
1928
1929static int __init journal_init_caches(void)
1930{
1931 int ret;
1932
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001933 ret = jbd2_journal_init_revoke_caches();
Dave Kleikamp470decc2006-10-11 01:20:57 -07001934 if (ret == 0)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001935 ret = journal_init_jbd2_journal_head_cache();
Dave Kleikamp470decc2006-10-11 01:20:57 -07001936 if (ret == 0)
1937 ret = journal_init_handle_cache();
1938 return ret;
1939}
1940
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001941static void jbd2_journal_destroy_caches(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001942{
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001943 jbd2_journal_destroy_revoke_caches();
1944 jbd2_journal_destroy_jbd2_journal_head_cache();
1945 jbd2_journal_destroy_handle_cache();
Dave Kleikamp470decc2006-10-11 01:20:57 -07001946}
1947
1948static int __init journal_init(void)
1949{
1950 int ret;
1951
1952 BUILD_BUG_ON(sizeof(struct journal_superblock_s) != 1024);
1953
1954 ret = journal_init_caches();
1955 if (ret != 0)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001956 jbd2_journal_destroy_caches();
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04001957 jbd2_create_debugfs_entry();
Dave Kleikamp470decc2006-10-11 01:20:57 -07001958 return ret;
1959}
1960
1961static void __exit journal_exit(void)
1962{
Jose R. Santose23291b2007-07-18 08:57:06 -04001963#ifdef CONFIG_JBD2_DEBUG
Dave Kleikamp470decc2006-10-11 01:20:57 -07001964 int n = atomic_read(&nr_journal_heads);
1965 if (n)
1966 printk(KERN_EMERG "JBD: leaked %d journal_heads!\n", n);
1967#endif
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04001968 jbd2_remove_debugfs_entry();
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001969 jbd2_journal_destroy_caches();
Dave Kleikamp470decc2006-10-11 01:20:57 -07001970}
1971
1972MODULE_LICENSE("GPL");
1973module_init(journal_init);
1974module_exit(journal_exit);
1975