blob: fed85388ee86434509805091a933b34091c50596 [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>
Simon Holm Thøgersenc225aa52009-01-11 22:34:01 -050040#include <linux/math64.h>
Theodore Ts'o879c5e62009-06-17 11:47:48 -040041#include <linux/hash.h>
42
43#define CREATE_TRACE_POINTS
44#include <trace/events/jbd2.h>
Dave Kleikamp470decc2006-10-11 01:20:57 -070045
46#include <asm/uaccess.h>
47#include <asm/page.h>
48
Mingming Caof7f4bcc2006-10-11 01:20:59 -070049EXPORT_SYMBOL(jbd2_journal_start);
50EXPORT_SYMBOL(jbd2_journal_restart);
51EXPORT_SYMBOL(jbd2_journal_extend);
52EXPORT_SYMBOL(jbd2_journal_stop);
53EXPORT_SYMBOL(jbd2_journal_lock_updates);
54EXPORT_SYMBOL(jbd2_journal_unlock_updates);
55EXPORT_SYMBOL(jbd2_journal_get_write_access);
56EXPORT_SYMBOL(jbd2_journal_get_create_access);
57EXPORT_SYMBOL(jbd2_journal_get_undo_access);
Joel Beckere06c8222008-09-11 15:35:47 -070058EXPORT_SYMBOL(jbd2_journal_set_triggers);
Mingming Caof7f4bcc2006-10-11 01:20:59 -070059EXPORT_SYMBOL(jbd2_journal_dirty_metadata);
60EXPORT_SYMBOL(jbd2_journal_release_buffer);
61EXPORT_SYMBOL(jbd2_journal_forget);
Dave Kleikamp470decc2006-10-11 01:20:57 -070062#if 0
63EXPORT_SYMBOL(journal_sync_buffer);
64#endif
Mingming Caof7f4bcc2006-10-11 01:20:59 -070065EXPORT_SYMBOL(jbd2_journal_flush);
66EXPORT_SYMBOL(jbd2_journal_revoke);
Dave Kleikamp470decc2006-10-11 01:20:57 -070067
Mingming Caof7f4bcc2006-10-11 01:20:59 -070068EXPORT_SYMBOL(jbd2_journal_init_dev);
69EXPORT_SYMBOL(jbd2_journal_init_inode);
70EXPORT_SYMBOL(jbd2_journal_update_format);
71EXPORT_SYMBOL(jbd2_journal_check_used_features);
72EXPORT_SYMBOL(jbd2_journal_check_available_features);
73EXPORT_SYMBOL(jbd2_journal_set_features);
Mingming Caof7f4bcc2006-10-11 01:20:59 -070074EXPORT_SYMBOL(jbd2_journal_load);
75EXPORT_SYMBOL(jbd2_journal_destroy);
Mingming Caof7f4bcc2006-10-11 01:20:59 -070076EXPORT_SYMBOL(jbd2_journal_abort);
77EXPORT_SYMBOL(jbd2_journal_errno);
78EXPORT_SYMBOL(jbd2_journal_ack_err);
79EXPORT_SYMBOL(jbd2_journal_clear_err);
80EXPORT_SYMBOL(jbd2_log_wait_commit);
81EXPORT_SYMBOL(jbd2_journal_start_commit);
82EXPORT_SYMBOL(jbd2_journal_force_commit_nested);
83EXPORT_SYMBOL(jbd2_journal_wipe);
84EXPORT_SYMBOL(jbd2_journal_blocks_per_page);
85EXPORT_SYMBOL(jbd2_journal_invalidatepage);
86EXPORT_SYMBOL(jbd2_journal_try_to_free_buffers);
87EXPORT_SYMBOL(jbd2_journal_force_commit);
Jan Karac851ed52008-07-11 19:27:31 -040088EXPORT_SYMBOL(jbd2_journal_file_inode);
89EXPORT_SYMBOL(jbd2_journal_init_jbd_inode);
90EXPORT_SYMBOL(jbd2_journal_release_jbd_inode);
91EXPORT_SYMBOL(jbd2_journal_begin_ordered_truncate);
Dave Kleikamp470decc2006-10-11 01:20:57 -070092
93static int journal_convert_superblock_v1(journal_t *, journal_superblock_t *);
94static void __journal_abort_soft (journal_t *journal, int errno);
Dave Kleikamp470decc2006-10-11 01:20:57 -070095
96/*
97 * Helper function used to manage commit timeouts
98 */
99
100static void commit_timeout(unsigned long __data)
101{
102 struct task_struct * p = (struct task_struct *) __data;
103
104 wake_up_process(p);
105}
106
107/*
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700108 * kjournald2: The main thread function used to manage a logging device
Dave Kleikamp470decc2006-10-11 01:20:57 -0700109 * journal.
110 *
111 * This kernel thread is responsible for two things:
112 *
113 * 1) COMMIT: Every so often we need to commit the current state of the
114 * filesystem to disk. The journal thread is responsible for writing
115 * all of the metadata buffers to disk.
116 *
117 * 2) CHECKPOINT: We cannot reuse a used section of the log file until all
118 * of the data in that part of the log has been rewritten elsewhere on
119 * the disk. Flushing these old buffers to reclaim space in the log is
120 * known as checkpointing, and this thread is responsible for that job.
121 */
122
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700123static int kjournald2(void *arg)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700124{
125 journal_t *journal = arg;
126 transaction_t *transaction;
127
128 /*
129 * Set up an interval timer which can be used to trigger a commit wakeup
130 * after the commit interval expires
131 */
132 setup_timer(&journal->j_commit_timer, commit_timeout,
133 (unsigned long)current);
134
135 /* Record that the journal thread is running */
136 journal->j_task = current;
137 wake_up(&journal->j_wait_done_commit);
138
Dave Kleikamp470decc2006-10-11 01:20:57 -0700139 /*
140 * And now, wait forever for commit wakeup events.
141 */
142 spin_lock(&journal->j_state_lock);
143
144loop:
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700145 if (journal->j_flags & JBD2_UNMOUNT)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700146 goto end_loop;
147
148 jbd_debug(1, "commit_sequence=%d, commit_request=%d\n",
149 journal->j_commit_sequence, journal->j_commit_request);
150
151 if (journal->j_commit_sequence != journal->j_commit_request) {
152 jbd_debug(1, "OK, requests differ\n");
153 spin_unlock(&journal->j_state_lock);
154 del_timer_sync(&journal->j_commit_timer);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700155 jbd2_journal_commit_transaction(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700156 spin_lock(&journal->j_state_lock);
157 goto loop;
158 }
159
160 wake_up(&journal->j_wait_done_commit);
161 if (freezing(current)) {
162 /*
163 * The simpler the better. Flushing journal isn't a
164 * good idea, because that depends on threads that may
165 * be already stopped.
166 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700167 jbd_debug(1, "Now suspending kjournald2\n");
Dave Kleikamp470decc2006-10-11 01:20:57 -0700168 spin_unlock(&journal->j_state_lock);
169 refrigerator();
170 spin_lock(&journal->j_state_lock);
171 } else {
172 /*
173 * We assume on resume that commits are already there,
174 * so we don't sleep
175 */
176 DEFINE_WAIT(wait);
177 int should_sleep = 1;
178
179 prepare_to_wait(&journal->j_wait_commit, &wait,
180 TASK_INTERRUPTIBLE);
181 if (journal->j_commit_sequence != journal->j_commit_request)
182 should_sleep = 0;
183 transaction = journal->j_running_transaction;
184 if (transaction && time_after_eq(jiffies,
185 transaction->t_expires))
186 should_sleep = 0;
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700187 if (journal->j_flags & JBD2_UNMOUNT)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700188 should_sleep = 0;
189 if (should_sleep) {
190 spin_unlock(&journal->j_state_lock);
191 schedule();
192 spin_lock(&journal->j_state_lock);
193 }
194 finish_wait(&journal->j_wait_commit, &wait);
195 }
196
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700197 jbd_debug(1, "kjournald2 wakes\n");
Dave Kleikamp470decc2006-10-11 01:20:57 -0700198
199 /*
200 * Were we woken up by a commit wakeup event?
201 */
202 transaction = journal->j_running_transaction;
203 if (transaction && time_after_eq(jiffies, transaction->t_expires)) {
204 journal->j_commit_request = transaction->t_tid;
205 jbd_debug(1, "woke because of timeout\n");
206 }
207 goto loop;
208
209end_loop:
210 spin_unlock(&journal->j_state_lock);
211 del_timer_sync(&journal->j_commit_timer);
212 journal->j_task = NULL;
213 wake_up(&journal->j_wait_done_commit);
214 jbd_debug(1, "Journal thread exiting.\n");
215 return 0;
216}
217
Pavel Emelianov97f06782007-05-08 00:30:42 -0700218static int jbd2_journal_start_thread(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700219{
Pavel Emelianov97f06782007-05-08 00:30:42 -0700220 struct task_struct *t;
221
Theodore Ts'o90576c02009-09-29 15:51:30 -0400222 t = kthread_run(kjournald2, journal, "jbd2/%s",
223 journal->j_devname);
Pavel Emelianov97f06782007-05-08 00:30:42 -0700224 if (IS_ERR(t))
225 return PTR_ERR(t);
226
Al Viro1076d172008-03-29 03:07:18 +0000227 wait_event(journal->j_wait_done_commit, journal->j_task != NULL);
Pavel Emelianov97f06782007-05-08 00:30:42 -0700228 return 0;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700229}
230
231static void journal_kill_thread(journal_t *journal)
232{
233 spin_lock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700234 journal->j_flags |= JBD2_UNMOUNT;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700235
236 while (journal->j_task) {
237 wake_up(&journal->j_wait_commit);
238 spin_unlock(&journal->j_state_lock);
Al Viro1076d172008-03-29 03:07:18 +0000239 wait_event(journal->j_wait_done_commit, journal->j_task == NULL);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700240 spin_lock(&journal->j_state_lock);
241 }
242 spin_unlock(&journal->j_state_lock);
243}
244
245/*
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700246 * jbd2_journal_write_metadata_buffer: write a metadata buffer to the journal.
Dave Kleikamp470decc2006-10-11 01:20:57 -0700247 *
248 * Writes a metadata buffer to a given disk block. The actual IO is not
249 * performed but a new buffer_head is constructed which labels the data
250 * to be written with the correct destination disk block.
251 *
252 * Any magic-number escaping which needs to be done will cause a
253 * copy-out here. If the buffer happens to start with the
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700254 * JBD2_MAGIC_NUMBER, then we can't write it to the log directly: the
Dave Kleikamp470decc2006-10-11 01:20:57 -0700255 * magic number is only written to the log for descripter blocks. In
256 * this case, we copy the data and replace the first word with 0, and we
257 * return a result code which indicates that this buffer needs to be
258 * marked as an escaped buffer in the corresponding log descriptor
259 * block. The missing word can then be restored when the block is read
260 * during recovery.
261 *
262 * If the source buffer has already been modified by a new transaction
263 * since we took the last commit snapshot, we use the frozen copy of
264 * that data for IO. If we end up using the existing buffer_head's data
265 * for the write, then we *have* to lock the buffer to prevent anyone
266 * else from using and possibly modifying it while the IO is in
267 * progress.
268 *
269 * The function returns a pointer to the buffer_heads to be used for IO.
270 *
271 * We assume that the journal has already been locked in this function.
272 *
273 * Return value:
274 * <0: Error
275 * >=0: Finished OK
276 *
277 * On success:
278 * Bit 0 set == escape performed on the data
279 * Bit 1 set == buffer copy-out performed (kfree the data after IO)
280 */
281
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700282int jbd2_journal_write_metadata_buffer(transaction_t *transaction,
Dave Kleikamp470decc2006-10-11 01:20:57 -0700283 struct journal_head *jh_in,
284 struct journal_head **jh_out,
Mingming Cao18eba7a2006-10-11 01:21:13 -0700285 unsigned long long blocknr)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700286{
287 int need_copy_out = 0;
288 int done_copy_out = 0;
289 int do_escape = 0;
290 char *mapped_data;
291 struct buffer_head *new_bh;
292 struct journal_head *new_jh;
293 struct page *new_page;
294 unsigned int new_offset;
295 struct buffer_head *bh_in = jh2bh(jh_in);
Joel Beckere06c8222008-09-11 15:35:47 -0700296 struct jbd2_buffer_trigger_type *triggers;
dingdinghua96577c42009-07-13 17:55:35 -0400297 journal_t *journal = transaction->t_journal;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700298
299 /*
300 * The buffer really shouldn't be locked: only the current committing
301 * transaction is allowed to write it, so nobody else is allowed
302 * to do any IO.
303 *
304 * akpm: except if we're journalling data, and write() output is
305 * also part of a shared mapping, and another thread has
306 * decided to launch a writepage() against this buffer.
307 */
308 J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in));
309
310 new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL);
dingdinghua96577c42009-07-13 17:55:35 -0400311 /* keep subsequent assertions sane */
312 new_bh->b_state = 0;
313 init_buffer(new_bh, NULL, NULL);
314 atomic_set(&new_bh->b_count, 1);
315 new_jh = jbd2_journal_add_journal_head(new_bh); /* This sleeps */
Dave Kleikamp470decc2006-10-11 01:20:57 -0700316
317 /*
318 * If a new transaction has already done a buffer copy-out, then
319 * we use that version of the data for the commit.
320 */
321 jbd_lock_bh_state(bh_in);
322repeat:
323 if (jh_in->b_frozen_data) {
324 done_copy_out = 1;
325 new_page = virt_to_page(jh_in->b_frozen_data);
326 new_offset = offset_in_page(jh_in->b_frozen_data);
Joel Beckere06c8222008-09-11 15:35:47 -0700327 triggers = jh_in->b_frozen_triggers;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700328 } else {
329 new_page = jh2bh(jh_in)->b_page;
330 new_offset = offset_in_page(jh2bh(jh_in)->b_data);
Joel Beckere06c8222008-09-11 15:35:47 -0700331 triggers = jh_in->b_triggers;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700332 }
333
334 mapped_data = kmap_atomic(new_page, KM_USER0);
335 /*
Joel Beckere06c8222008-09-11 15:35:47 -0700336 * Fire any commit trigger. Do this before checking for escaping,
337 * as the trigger may modify the magic offset. If a copy-out
338 * happens afterwards, it will have the correct data in the buffer.
339 */
340 jbd2_buffer_commit_trigger(jh_in, mapped_data + new_offset,
341 triggers);
342
343 /*
Dave Kleikamp470decc2006-10-11 01:20:57 -0700344 * Check for escaping
345 */
346 if (*((__be32 *)(mapped_data + new_offset)) ==
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700347 cpu_to_be32(JBD2_MAGIC_NUMBER)) {
Dave Kleikamp470decc2006-10-11 01:20:57 -0700348 need_copy_out = 1;
349 do_escape = 1;
350 }
351 kunmap_atomic(mapped_data, KM_USER0);
352
353 /*
354 * Do we need to do a data copy?
355 */
356 if (need_copy_out && !done_copy_out) {
357 char *tmp;
358
359 jbd_unlock_bh_state(bh_in);
Mingming Caoaf1e76d2007-10-16 18:38:25 -0400360 tmp = jbd2_alloc(bh_in->b_size, GFP_NOFS);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700361 jbd_lock_bh_state(bh_in);
362 if (jh_in->b_frozen_data) {
Mingming Caoaf1e76d2007-10-16 18:38:25 -0400363 jbd2_free(tmp, bh_in->b_size);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700364 goto repeat;
365 }
366
367 jh_in->b_frozen_data = tmp;
368 mapped_data = kmap_atomic(new_page, KM_USER0);
369 memcpy(tmp, mapped_data + new_offset, jh2bh(jh_in)->b_size);
370 kunmap_atomic(mapped_data, KM_USER0);
371
372 new_page = virt_to_page(tmp);
373 new_offset = offset_in_page(tmp);
374 done_copy_out = 1;
Joel Beckere06c8222008-09-11 15:35:47 -0700375
376 /*
377 * This isn't strictly necessary, as we're using frozen
378 * data for the escaping, but it keeps consistency with
379 * b_frozen_data usage.
380 */
381 jh_in->b_frozen_triggers = jh_in->b_triggers;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700382 }
383
384 /*
385 * Did we need to do an escaping? Now we've done all the
386 * copying, we can finally do so.
387 */
388 if (do_escape) {
389 mapped_data = kmap_atomic(new_page, KM_USER0);
390 *((unsigned int *)(mapped_data + new_offset)) = 0;
391 kunmap_atomic(mapped_data, KM_USER0);
392 }
393
Dave Kleikamp470decc2006-10-11 01:20:57 -0700394 set_bh_page(new_bh, new_page, new_offset);
395 new_jh->b_transaction = NULL;
396 new_bh->b_size = jh2bh(jh_in)->b_size;
397 new_bh->b_bdev = transaction->t_journal->j_dev;
398 new_bh->b_blocknr = blocknr;
399 set_buffer_mapped(new_bh);
400 set_buffer_dirty(new_bh);
401
402 *jh_out = new_jh;
403
404 /*
405 * The to-be-written buffer needs to get moved to the io queue,
406 * and the original buffer whose contents we are shadowing or
407 * copying is moved to the transaction's shadow queue.
408 */
409 JBUFFER_TRACE(jh_in, "file as BJ_Shadow");
dingdinghua96577c42009-07-13 17:55:35 -0400410 spin_lock(&journal->j_list_lock);
411 __jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow);
412 spin_unlock(&journal->j_list_lock);
413 jbd_unlock_bh_state(bh_in);
414
Dave Kleikamp470decc2006-10-11 01:20:57 -0700415 JBUFFER_TRACE(new_jh, "file as BJ_IO");
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700416 jbd2_journal_file_buffer(new_jh, transaction, BJ_IO);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700417
418 return do_escape | (done_copy_out << 1);
419}
420
421/*
422 * Allocation code for the journal file. Manage the space left in the
423 * journal, so that we can begin checkpointing when appropriate.
424 */
425
426/*
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700427 * __jbd2_log_space_left: Return the number of free blocks left in the journal.
Dave Kleikamp470decc2006-10-11 01:20:57 -0700428 *
429 * Called with the journal already locked.
430 *
431 * Called under j_state_lock
432 */
433
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700434int __jbd2_log_space_left(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700435{
436 int left = journal->j_free;
437
438 assert_spin_locked(&journal->j_state_lock);
439
440 /*
441 * Be pessimistic here about the number of those free blocks which
442 * might be required for log descriptor control blocks.
443 */
444
445#define MIN_LOG_RESERVED_BLOCKS 32 /* Allow for rounding errors */
446
447 left -= MIN_LOG_RESERVED_BLOCKS;
448
449 if (left <= 0)
450 return 0;
451 left -= (left >> 3);
452 return left;
453}
454
455/*
Jan Karac88ccea2009-02-10 11:27:46 -0500456 * Called under j_state_lock. Returns true if a transaction commit was started.
Dave Kleikamp470decc2006-10-11 01:20:57 -0700457 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700458int __jbd2_log_start_commit(journal_t *journal, tid_t target)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700459{
460 /*
461 * Are we already doing a recent enough commit?
462 */
463 if (!tid_geq(journal->j_commit_request, target)) {
464 /*
465 * We want a new commit: OK, mark the request and wakup the
466 * commit thread. We do _not_ do the commit ourselves.
467 */
468
469 journal->j_commit_request = target;
470 jbd_debug(1, "JBD: requesting commit %d/%d\n",
471 journal->j_commit_request,
472 journal->j_commit_sequence);
473 wake_up(&journal->j_wait_commit);
474 return 1;
475 }
476 return 0;
477}
478
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700479int jbd2_log_start_commit(journal_t *journal, tid_t tid)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700480{
481 int ret;
482
483 spin_lock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700484 ret = __jbd2_log_start_commit(journal, tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700485 spin_unlock(&journal->j_state_lock);
486 return ret;
487}
488
489/*
490 * Force and wait upon a commit if the calling process is not within
491 * transaction. This is used for forcing out undo-protected data which contains
492 * bitmaps, when the fs is running out of space.
493 *
494 * We can only force the running transaction if we don't have an active handle;
495 * otherwise, we will deadlock.
496 *
497 * Returns true if a transaction was started.
498 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700499int jbd2_journal_force_commit_nested(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700500{
501 transaction_t *transaction = NULL;
502 tid_t tid;
503
504 spin_lock(&journal->j_state_lock);
505 if (journal->j_running_transaction && !current->journal_info) {
506 transaction = journal->j_running_transaction;
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700507 __jbd2_log_start_commit(journal, transaction->t_tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700508 } else if (journal->j_committing_transaction)
509 transaction = journal->j_committing_transaction;
510
511 if (!transaction) {
512 spin_unlock(&journal->j_state_lock);
513 return 0; /* Nothing to retry */
514 }
515
516 tid = transaction->t_tid;
517 spin_unlock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700518 jbd2_log_wait_commit(journal, tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700519 return 1;
520}
521
522/*
523 * Start a commit of the current running transaction (if any). Returns true
Jan Karac88ccea2009-02-10 11:27:46 -0500524 * if a transaction is going to be committed (or is currently already
525 * committing), and fills its tid in at *ptid
Dave Kleikamp470decc2006-10-11 01:20:57 -0700526 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700527int jbd2_journal_start_commit(journal_t *journal, tid_t *ptid)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700528{
529 int ret = 0;
530
531 spin_lock(&journal->j_state_lock);
532 if (journal->j_running_transaction) {
533 tid_t tid = journal->j_running_transaction->t_tid;
534
Jan Karac88ccea2009-02-10 11:27:46 -0500535 __jbd2_log_start_commit(journal, tid);
536 /* There's a running transaction and we've just made sure
537 * it's commit has been scheduled. */
538 if (ptid)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700539 *ptid = tid;
Jan Karac88ccea2009-02-10 11:27:46 -0500540 ret = 1;
541 } else if (journal->j_committing_transaction) {
Dave Kleikamp470decc2006-10-11 01:20:57 -0700542 /*
543 * If ext3_write_super() recently started a commit, then we
544 * have to wait for completion of that transaction
545 */
Jan Karac88ccea2009-02-10 11:27:46 -0500546 if (ptid)
547 *ptid = journal->j_committing_transaction->t_tid;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700548 ret = 1;
549 }
550 spin_unlock(&journal->j_state_lock);
551 return ret;
552}
553
554/*
555 * Wait for a specified commit to complete.
556 * The caller may not hold the journal lock.
557 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700558int jbd2_log_wait_commit(journal_t *journal, tid_t tid)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700559{
560 int err = 0;
561
Jose R. Santose23291b2007-07-18 08:57:06 -0400562#ifdef CONFIG_JBD2_DEBUG
Dave Kleikamp470decc2006-10-11 01:20:57 -0700563 spin_lock(&journal->j_state_lock);
564 if (!tid_geq(journal->j_commit_request, tid)) {
565 printk(KERN_EMERG
566 "%s: error: j_commit_request=%d, tid=%d\n",
Harvey Harrison329d2912008-04-17 10:38:59 -0400567 __func__, journal->j_commit_request, tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700568 }
569 spin_unlock(&journal->j_state_lock);
570#endif
571 spin_lock(&journal->j_state_lock);
572 while (tid_gt(tid, journal->j_commit_sequence)) {
573 jbd_debug(1, "JBD: want %d, j_commit_sequence=%d\n",
574 tid, journal->j_commit_sequence);
575 wake_up(&journal->j_wait_commit);
576 spin_unlock(&journal->j_state_lock);
577 wait_event(journal->j_wait_done_commit,
578 !tid_gt(tid, journal->j_commit_sequence));
579 spin_lock(&journal->j_state_lock);
580 }
581 spin_unlock(&journal->j_state_lock);
582
583 if (unlikely(is_journal_aborted(journal))) {
584 printk(KERN_EMERG "journal commit I/O error\n");
585 err = -EIO;
586 }
587 return err;
588}
589
590/*
591 * Log buffer allocation routines:
592 */
593
Mingming Cao18eba7a2006-10-11 01:21:13 -0700594int jbd2_journal_next_log_block(journal_t *journal, unsigned long long *retp)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700595{
596 unsigned long blocknr;
597
598 spin_lock(&journal->j_state_lock);
599 J_ASSERT(journal->j_free > 1);
600
601 blocknr = journal->j_head;
602 journal->j_head++;
603 journal->j_free--;
604 if (journal->j_head == journal->j_last)
605 journal->j_head = journal->j_first;
606 spin_unlock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700607 return jbd2_journal_bmap(journal, blocknr, retp);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700608}
609
610/*
611 * Conversion of logical to physical block numbers for the journal
612 *
613 * On external journals the journal blocks are identity-mapped, so
614 * this is a no-op. If needed, we can use j_blk_offset - everything is
615 * ready.
616 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700617int jbd2_journal_bmap(journal_t *journal, unsigned long blocknr,
Mingming Cao18eba7a2006-10-11 01:21:13 -0700618 unsigned long long *retp)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700619{
620 int err = 0;
Mingming Cao18eba7a2006-10-11 01:21:13 -0700621 unsigned long long ret;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700622
623 if (journal->j_inode) {
624 ret = bmap(journal->j_inode, blocknr);
625 if (ret)
626 *retp = ret;
627 else {
Dave Kleikamp470decc2006-10-11 01:20:57 -0700628 printk(KERN_ALERT "%s: journal block not found "
629 "at offset %lu on %s\n",
Theodore Ts'o05496762008-09-16 14:36:17 -0400630 __func__, blocknr, journal->j_devname);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700631 err = -EIO;
632 __journal_abort_soft(journal, err);
633 }
634 } else {
635 *retp = blocknr; /* +journal->j_blk_offset */
636 }
637 return err;
638}
639
640/*
641 * We play buffer_head aliasing tricks to write data/metadata blocks to
642 * the journal without copying their contents, but for journal
643 * descriptor blocks we do need to generate bona fide buffers.
644 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700645 * After the caller of jbd2_journal_get_descriptor_buffer() has finished modifying
Dave Kleikamp470decc2006-10-11 01:20:57 -0700646 * the buffer's contents they really should run flush_dcache_page(bh->b_page).
647 * But we don't bother doing that, so there will be coherency problems with
648 * mmaps of blockdevs which hold live JBD-controlled filesystems.
649 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700650struct journal_head *jbd2_journal_get_descriptor_buffer(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700651{
652 struct buffer_head *bh;
Mingming Cao18eba7a2006-10-11 01:21:13 -0700653 unsigned long long blocknr;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700654 int err;
655
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700656 err = jbd2_journal_next_log_block(journal, &blocknr);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700657
658 if (err)
659 return NULL;
660
661 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
Jan Kara4b905672009-01-06 14:53:35 -0500662 if (!bh)
663 return NULL;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700664 lock_buffer(bh);
665 memset(bh->b_data, 0, journal->j_blocksize);
666 set_buffer_uptodate(bh);
667 unlock_buffer(bh);
668 BUFFER_TRACE(bh, "return this buffer");
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700669 return jbd2_journal_add_journal_head(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700670}
671
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500672struct jbd2_stats_proc_session {
673 journal_t *journal;
674 struct transaction_stats_s *stats;
675 int start;
676 int max;
677};
678
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500679static void *jbd2_seq_info_start(struct seq_file *seq, loff_t *pos)
680{
681 return *pos ? NULL : SEQ_START_TOKEN;
682}
683
684static void *jbd2_seq_info_next(struct seq_file *seq, void *v, loff_t *pos)
685{
686 return NULL;
687}
688
689static int jbd2_seq_info_show(struct seq_file *seq, void *v)
690{
691 struct jbd2_stats_proc_session *s = seq->private;
692
693 if (v != SEQ_START_TOKEN)
694 return 0;
Theodore Ts'obf699322009-09-30 00:32:06 -0400695 seq_printf(seq, "%lu transaction, each up to %u blocks\n",
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500696 s->stats->ts_tid,
697 s->journal->j_max_transaction_buffers);
698 if (s->stats->ts_tid == 0)
699 return 0;
700 seq_printf(seq, "average: \n %ums waiting for transaction\n",
Theodore Ts'obf699322009-09-30 00:32:06 -0400701 jiffies_to_msecs(s->stats->run.rs_wait / s->stats->ts_tid));
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500702 seq_printf(seq, " %ums running transaction\n",
Theodore Ts'obf699322009-09-30 00:32:06 -0400703 jiffies_to_msecs(s->stats->run.rs_running / s->stats->ts_tid));
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500704 seq_printf(seq, " %ums transaction was being locked\n",
Theodore Ts'obf699322009-09-30 00:32:06 -0400705 jiffies_to_msecs(s->stats->run.rs_locked / s->stats->ts_tid));
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500706 seq_printf(seq, " %ums flushing data (in ordered mode)\n",
Theodore Ts'obf699322009-09-30 00:32:06 -0400707 jiffies_to_msecs(s->stats->run.rs_flushing / s->stats->ts_tid));
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500708 seq_printf(seq, " %ums logging transaction\n",
Theodore Ts'obf699322009-09-30 00:32:06 -0400709 jiffies_to_msecs(s->stats->run.rs_logging / s->stats->ts_tid));
Simon Holm Thøgersenc225aa52009-01-11 22:34:01 -0500710 seq_printf(seq, " %lluus average transaction commit time\n",
711 div_u64(s->journal->j_average_commit_time, 1000));
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500712 seq_printf(seq, " %lu handles per transaction\n",
Theodore Ts'obf699322009-09-30 00:32:06 -0400713 s->stats->run.rs_handle_count / s->stats->ts_tid);
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500714 seq_printf(seq, " %lu blocks per transaction\n",
Theodore Ts'obf699322009-09-30 00:32:06 -0400715 s->stats->run.rs_blocks / s->stats->ts_tid);
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500716 seq_printf(seq, " %lu logged blocks per transaction\n",
Theodore Ts'obf699322009-09-30 00:32:06 -0400717 s->stats->run.rs_blocks_logged / s->stats->ts_tid);
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500718 return 0;
719}
720
721static void jbd2_seq_info_stop(struct seq_file *seq, void *v)
722{
723}
724
James Morris88e9d342009-09-22 16:43:43 -0700725static const struct seq_operations jbd2_seq_info_ops = {
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500726 .start = jbd2_seq_info_start,
727 .next = jbd2_seq_info_next,
728 .stop = jbd2_seq_info_stop,
729 .show = jbd2_seq_info_show,
730};
731
732static int jbd2_seq_info_open(struct inode *inode, struct file *file)
733{
734 journal_t *journal = PDE(inode)->data;
735 struct jbd2_stats_proc_session *s;
736 int rc, size;
737
738 s = kmalloc(sizeof(*s), GFP_KERNEL);
739 if (s == NULL)
740 return -ENOMEM;
741 size = sizeof(struct transaction_stats_s);
742 s->stats = kmalloc(size, GFP_KERNEL);
743 if (s->stats == NULL) {
744 kfree(s);
745 return -ENOMEM;
746 }
747 spin_lock(&journal->j_history_lock);
748 memcpy(s->stats, &journal->j_stats, size);
749 s->journal = journal;
750 spin_unlock(&journal->j_history_lock);
751
752 rc = seq_open(file, &jbd2_seq_info_ops);
753 if (rc == 0) {
754 struct seq_file *m = file->private_data;
755 m->private = s;
756 } else {
757 kfree(s->stats);
758 kfree(s);
759 }
760 return rc;
761
762}
763
764static int jbd2_seq_info_release(struct inode *inode, struct file *file)
765{
766 struct seq_file *seq = file->private_data;
767 struct jbd2_stats_proc_session *s = seq->private;
768 kfree(s->stats);
769 kfree(s);
770 return seq_release(inode, file);
771}
772
Alexey Dobriyan828c0952009-10-01 15:43:56 -0700773static const struct file_operations jbd2_seq_info_fops = {
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500774 .owner = THIS_MODULE,
775 .open = jbd2_seq_info_open,
776 .read = seq_read,
777 .llseek = seq_lseek,
778 .release = jbd2_seq_info_release,
779};
780
781static struct proc_dir_entry *proc_jbd2_stats;
782
783static void jbd2_stats_proc_init(journal_t *journal)
784{
Theodore Ts'o05496762008-09-16 14:36:17 -0400785 journal->j_proc_entry = proc_mkdir(journal->j_devname, proc_jbd2_stats);
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500786 if (journal->j_proc_entry) {
Denis V. Lunev79da3662008-04-29 01:02:11 -0700787 proc_create_data("info", S_IRUGO, journal->j_proc_entry,
788 &jbd2_seq_info_fops, journal);
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500789 }
790}
791
792static void jbd2_stats_proc_exit(journal_t *journal)
793{
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500794 remove_proc_entry("info", journal->j_proc_entry);
Theodore Ts'o05496762008-09-16 14:36:17 -0400795 remove_proc_entry(journal->j_devname, proc_jbd2_stats);
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500796}
797
Dave Kleikamp470decc2006-10-11 01:20:57 -0700798/*
799 * Management for journal control blocks: functions to create and
800 * destroy journal_t structures, and to initialise and read existing
801 * journal blocks from disk. */
802
803/* First: create and setup a journal_t object in memory. We initialise
804 * very few fields yet: that has to wait until we have created the
805 * journal structures from from scratch, or loaded them from disk. */
806
807static journal_t * journal_init_common (void)
808{
809 journal_t *journal;
810 int err;
811
Mingming Caod802ffa2007-10-16 18:38:25 -0400812 journal = kzalloc(sizeof(*journal), GFP_KERNEL|__GFP_NOFAIL);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700813 if (!journal)
814 goto fail;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700815
816 init_waitqueue_head(&journal->j_wait_transaction_locked);
817 init_waitqueue_head(&journal->j_wait_logspace);
818 init_waitqueue_head(&journal->j_wait_done_commit);
819 init_waitqueue_head(&journal->j_wait_checkpoint);
820 init_waitqueue_head(&journal->j_wait_commit);
821 init_waitqueue_head(&journal->j_wait_updates);
822 mutex_init(&journal->j_barrier);
823 mutex_init(&journal->j_checkpoint_mutex);
824 spin_lock_init(&journal->j_revoke_lock);
825 spin_lock_init(&journal->j_list_lock);
826 spin_lock_init(&journal->j_state_lock);
827
Mingming Caocd02ff02007-10-16 18:38:25 -0400828 journal->j_commit_interval = (HZ * JBD2_DEFAULT_MAX_COMMIT_AGE);
Theodore Ts'o30773842009-01-03 20:27:38 -0500829 journal->j_min_batch_time = 0;
830 journal->j_max_batch_time = 15000; /* 15ms */
Dave Kleikamp470decc2006-10-11 01:20:57 -0700831
832 /* The journal is marked for error until we succeed with recovery! */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700833 journal->j_flags = JBD2_ABORT;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700834
835 /* Set up a default-sized revoke table for the new mount. */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700836 err = jbd2_journal_init_revoke(journal, JOURNAL_REVOKE_DEFAULT_HASH);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700837 if (err) {
838 kfree(journal);
839 goto fail;
840 }
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500841
Theodore Ts'obf699322009-09-30 00:32:06 -0400842 spin_lock_init(&journal->j_history_lock);
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500843
Dave Kleikamp470decc2006-10-11 01:20:57 -0700844 return journal;
845fail:
846 return NULL;
847}
848
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700849/* jbd2_journal_init_dev and jbd2_journal_init_inode:
Dave Kleikamp470decc2006-10-11 01:20:57 -0700850 *
851 * Create a journal structure assigned some fixed set of disk blocks to
852 * the journal. We don't actually touch those disk blocks yet, but we
853 * need to set up all of the mapping information to tell the journaling
854 * system where the journal blocks are.
855 *
856 */
857
858/**
Randy Dunlap5648ba52008-04-17 10:38:59 -0400859 * journal_t * jbd2_journal_init_dev() - creates and initialises a journal structure
Dave Kleikamp470decc2006-10-11 01:20:57 -0700860 * @bdev: Block device on which to create the journal
861 * @fs_dev: Device which hold journalled filesystem for this journal.
862 * @start: Block nr Start of journal.
863 * @len: Length of the journal in blocks.
864 * @blocksize: blocksize of journalling device
Randy Dunlap5648ba52008-04-17 10:38:59 -0400865 *
866 * Returns: a newly created journal_t *
Dave Kleikamp470decc2006-10-11 01:20:57 -0700867 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700868 * jbd2_journal_init_dev creates a journal which maps a fixed contiguous
Dave Kleikamp470decc2006-10-11 01:20:57 -0700869 * range of blocks on an arbitrary block device.
870 *
871 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700872journal_t * jbd2_journal_init_dev(struct block_device *bdev,
Dave Kleikamp470decc2006-10-11 01:20:57 -0700873 struct block_device *fs_dev,
Mingming Cao18eba7a2006-10-11 01:21:13 -0700874 unsigned long long start, int len, int blocksize)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700875{
876 journal_t *journal = journal_init_common();
877 struct buffer_head *bh;
Theodore Ts'o05496762008-09-16 14:36:17 -0400878 char *p;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700879 int n;
880
881 if (!journal)
882 return NULL;
883
884 /* journal descriptor can store up to n blocks -bzzz */
885 journal->j_blocksize = blocksize;
Jan Kara4b905672009-01-06 14:53:35 -0500886 jbd2_stats_proc_init(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700887 n = journal->j_blocksize / sizeof(journal_block_tag_t);
888 journal->j_wbufsize = n;
889 journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
890 if (!journal->j_wbuf) {
891 printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n",
Harvey Harrison329d2912008-04-17 10:38:59 -0400892 __func__);
Jan Kara4b905672009-01-06 14:53:35 -0500893 goto out_err;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700894 }
895 journal->j_dev = bdev;
896 journal->j_fs_dev = fs_dev;
897 journal->j_blk_offset = start;
898 journal->j_maxlen = len;
Theodore Ts'o05496762008-09-16 14:36:17 -0400899 bdevname(journal->j_dev, journal->j_devname);
900 p = journal->j_devname;
901 while ((p = strchr(p, '/')))
902 *p = '!';
Dave Kleikamp470decc2006-10-11 01:20:57 -0700903
904 bh = __getblk(journal->j_dev, start, journal->j_blocksize);
Jan Kara4b905672009-01-06 14:53:35 -0500905 if (!bh) {
906 printk(KERN_ERR
907 "%s: Cannot get buffer for journal superblock\n",
908 __func__);
909 goto out_err;
910 }
Dave Kleikamp470decc2006-10-11 01:20:57 -0700911 journal->j_sb_buffer = bh;
912 journal->j_superblock = (journal_superblock_t *)bh->b_data;
Jan Kara4b905672009-01-06 14:53:35 -0500913
Dave Kleikamp470decc2006-10-11 01:20:57 -0700914 return journal;
Jan Kara4b905672009-01-06 14:53:35 -0500915out_err:
Tao Ma7b02bec2009-11-10 17:13:22 +0800916 kfree(journal->j_wbuf);
Jan Kara4b905672009-01-06 14:53:35 -0500917 jbd2_stats_proc_exit(journal);
918 kfree(journal);
919 return NULL;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700920}
921
922/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700923 * journal_t * jbd2_journal_init_inode () - creates a journal which maps to a inode.
Dave Kleikamp470decc2006-10-11 01:20:57 -0700924 * @inode: An inode to create the journal in
925 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700926 * jbd2_journal_init_inode creates a journal which maps an on-disk inode as
Dave Kleikamp470decc2006-10-11 01:20:57 -0700927 * the journal. The inode must exist already, must support bmap() and
928 * must have all data blocks preallocated.
929 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700930journal_t * jbd2_journal_init_inode (struct inode *inode)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700931{
932 struct buffer_head *bh;
933 journal_t *journal = journal_init_common();
Theodore Ts'o05496762008-09-16 14:36:17 -0400934 char *p;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700935 int err;
936 int n;
Mingming Cao18eba7a2006-10-11 01:21:13 -0700937 unsigned long long blocknr;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700938
939 if (!journal)
940 return NULL;
941
942 journal->j_dev = journal->j_fs_dev = inode->i_sb->s_bdev;
943 journal->j_inode = inode;
Theodore Ts'o05496762008-09-16 14:36:17 -0400944 bdevname(journal->j_dev, journal->j_devname);
945 p = journal->j_devname;
946 while ((p = strchr(p, '/')))
947 *p = '!';
948 p = journal->j_devname + strlen(journal->j_devname);
Theodore Ts'o90576c02009-09-29 15:51:30 -0400949 sprintf(p, "-%lu", journal->j_inode->i_ino);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700950 jbd_debug(1,
951 "journal %p: inode %s/%ld, size %Ld, bits %d, blksize %ld\n",
952 journal, inode->i_sb->s_id, inode->i_ino,
953 (long long) inode->i_size,
954 inode->i_sb->s_blocksize_bits, inode->i_sb->s_blocksize);
955
956 journal->j_maxlen = inode->i_size >> inode->i_sb->s_blocksize_bits;
957 journal->j_blocksize = inode->i_sb->s_blocksize;
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500958 jbd2_stats_proc_init(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700959
960 /* journal descriptor can store up to n blocks -bzzz */
961 n = journal->j_blocksize / sizeof(journal_block_tag_t);
962 journal->j_wbufsize = n;
963 journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
964 if (!journal->j_wbuf) {
965 printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n",
Harvey Harrison329d2912008-04-17 10:38:59 -0400966 __func__);
Jan Kara4b905672009-01-06 14:53:35 -0500967 goto out_err;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700968 }
969
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700970 err = jbd2_journal_bmap(journal, 0, &blocknr);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700971 /* If that failed, give up */
972 if (err) {
973 printk(KERN_ERR "%s: Cannnot locate journal superblock\n",
Harvey Harrison329d2912008-04-17 10:38:59 -0400974 __func__);
Jan Kara4b905672009-01-06 14:53:35 -0500975 goto out_err;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700976 }
977
978 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
Jan Kara4b905672009-01-06 14:53:35 -0500979 if (!bh) {
980 printk(KERN_ERR
981 "%s: Cannot get buffer for journal superblock\n",
982 __func__);
983 goto out_err;
984 }
Dave Kleikamp470decc2006-10-11 01:20:57 -0700985 journal->j_sb_buffer = bh;
986 journal->j_superblock = (journal_superblock_t *)bh->b_data;
987
988 return journal;
Jan Kara4b905672009-01-06 14:53:35 -0500989out_err:
Tao Ma7b02bec2009-11-10 17:13:22 +0800990 kfree(journal->j_wbuf);
Jan Kara4b905672009-01-06 14:53:35 -0500991 jbd2_stats_proc_exit(journal);
992 kfree(journal);
993 return NULL;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700994}
995
996/*
997 * If the journal init or create aborts, we need to mark the journal
998 * superblock as being NULL to prevent the journal destroy from writing
999 * back a bogus superblock.
1000 */
1001static void journal_fail_superblock (journal_t *journal)
1002{
1003 struct buffer_head *bh = journal->j_sb_buffer;
1004 brelse(bh);
1005 journal->j_sb_buffer = NULL;
1006}
1007
1008/*
1009 * Given a journal_t structure, initialise the various fields for
1010 * startup of a new journaling session. We use this both when creating
1011 * a journal, and after recovering an old journal to reset it for
1012 * subsequent use.
1013 */
1014
1015static int journal_reset(journal_t *journal)
1016{
1017 journal_superblock_t *sb = journal->j_superblock;
Mingming Cao18eba7a2006-10-11 01:21:13 -07001018 unsigned long long first, last;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001019
1020 first = be32_to_cpu(sb->s_first);
1021 last = be32_to_cpu(sb->s_maxlen);
Jan Karaf6f50e22009-07-17 10:40:01 -04001022 if (first + JBD2_MIN_JOURNAL_BLOCKS > last + 1) {
1023 printk(KERN_ERR "JBD: Journal too short (blocks %llu-%llu).\n",
1024 first, last);
1025 journal_fail_superblock(journal);
1026 return -EINVAL;
1027 }
Dave Kleikamp470decc2006-10-11 01:20:57 -07001028
1029 journal->j_first = first;
1030 journal->j_last = last;
1031
1032 journal->j_head = first;
1033 journal->j_tail = first;
1034 journal->j_free = last - first;
1035
1036 journal->j_tail_sequence = journal->j_transaction_sequence;
1037 journal->j_commit_sequence = journal->j_transaction_sequence - 1;
1038 journal->j_commit_request = journal->j_commit_sequence;
1039
1040 journal->j_max_transaction_buffers = journal->j_maxlen / 4;
1041
1042 /* Add the dynamic fields and write it to disk. */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001043 jbd2_journal_update_superblock(journal, 1);
Pavel Emelianov97f06782007-05-08 00:30:42 -07001044 return jbd2_journal_start_thread(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001045}
1046
1047/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001048 * void jbd2_journal_update_superblock() - Update journal sb on disk.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001049 * @journal: The journal to update.
1050 * @wait: Set to '0' if you don't want to wait for IO completion.
1051 *
1052 * Update a journal's dynamic superblock fields and write it to disk,
1053 * optionally waiting for the IO to complete.
1054 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001055void jbd2_journal_update_superblock(journal_t *journal, int wait)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001056{
1057 journal_superblock_t *sb = journal->j_superblock;
1058 struct buffer_head *bh = journal->j_sb_buffer;
1059
1060 /*
1061 * As a special case, if the on-disk copy is already marked as needing
1062 * no recovery (s_start == 0) and there are no outstanding transactions
1063 * in the filesystem, then we can safely defer the superblock update
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001064 * until the next commit by setting JBD2_FLUSHED. This avoids
Dave Kleikamp470decc2006-10-11 01:20:57 -07001065 * attempting a write to a potential-readonly device.
1066 */
1067 if (sb->s_start == 0 && journal->j_tail_sequence ==
1068 journal->j_transaction_sequence) {
1069 jbd_debug(1,"JBD: Skipping superblock update on recovered sb "
1070 "(start %ld, seq %d, errno %d)\n",
1071 journal->j_tail, journal->j_tail_sequence,
1072 journal->j_errno);
1073 goto out;
1074 }
1075
Theodore Ts'o914258b2008-10-06 21:35:40 -04001076 if (buffer_write_io_error(bh)) {
1077 /*
1078 * Oh, dear. A previous attempt to write the journal
1079 * superblock failed. This could happen because the
1080 * USB device was yanked out. Or it could happen to
1081 * be a transient write error and maybe the block will
1082 * be remapped. Nothing we can do but to retry the
1083 * write and hope for the best.
1084 */
1085 printk(KERN_ERR "JBD2: previous I/O error detected "
1086 "for journal superblock update for %s.\n",
1087 journal->j_devname);
1088 clear_buffer_write_io_error(bh);
1089 set_buffer_uptodate(bh);
1090 }
1091
Dave Kleikamp470decc2006-10-11 01:20:57 -07001092 spin_lock(&journal->j_state_lock);
1093 jbd_debug(1,"JBD: updating superblock (start %ld, seq %d, errno %d)\n",
1094 journal->j_tail, journal->j_tail_sequence, journal->j_errno);
1095
1096 sb->s_sequence = cpu_to_be32(journal->j_tail_sequence);
1097 sb->s_start = cpu_to_be32(journal->j_tail);
1098 sb->s_errno = cpu_to_be32(journal->j_errno);
1099 spin_unlock(&journal->j_state_lock);
1100
1101 BUFFER_TRACE(bh, "marking dirty");
1102 mark_buffer_dirty(bh);
Theodore Ts'o914258b2008-10-06 21:35:40 -04001103 if (wait) {
Dave Kleikamp470decc2006-10-11 01:20:57 -07001104 sync_dirty_buffer(bh);
Theodore Ts'o914258b2008-10-06 21:35:40 -04001105 if (buffer_write_io_error(bh)) {
1106 printk(KERN_ERR "JBD2: I/O error detected "
1107 "when updating journal superblock for %s.\n",
1108 journal->j_devname);
1109 clear_buffer_write_io_error(bh);
1110 set_buffer_uptodate(bh);
1111 }
1112 } else
Dave Kleikamp470decc2006-10-11 01:20:57 -07001113 ll_rw_block(SWRITE, 1, &bh);
1114
1115out:
1116 /* If we have just flushed the log (by marking s_start==0), then
1117 * any future commit will have to be careful to update the
1118 * superblock again to re-record the true start of the log. */
1119
1120 spin_lock(&journal->j_state_lock);
1121 if (sb->s_start)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001122 journal->j_flags &= ~JBD2_FLUSHED;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001123 else
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001124 journal->j_flags |= JBD2_FLUSHED;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001125 spin_unlock(&journal->j_state_lock);
1126}
1127
1128/*
1129 * Read the superblock for a given journal, performing initial
1130 * validation of the format.
1131 */
1132
1133static int journal_get_superblock(journal_t *journal)
1134{
1135 struct buffer_head *bh;
1136 journal_superblock_t *sb;
1137 int err = -EIO;
1138
1139 bh = journal->j_sb_buffer;
1140
1141 J_ASSERT(bh != NULL);
1142 if (!buffer_uptodate(bh)) {
1143 ll_rw_block(READ, 1, &bh);
1144 wait_on_buffer(bh);
1145 if (!buffer_uptodate(bh)) {
1146 printk (KERN_ERR
1147 "JBD: IO error reading journal superblock\n");
1148 goto out;
1149 }
1150 }
1151
1152 sb = journal->j_superblock;
1153
1154 err = -EINVAL;
1155
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001156 if (sb->s_header.h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER) ||
Dave Kleikamp470decc2006-10-11 01:20:57 -07001157 sb->s_blocksize != cpu_to_be32(journal->j_blocksize)) {
1158 printk(KERN_WARNING "JBD: no valid journal superblock found\n");
1159 goto out;
1160 }
1161
1162 switch(be32_to_cpu(sb->s_header.h_blocktype)) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001163 case JBD2_SUPERBLOCK_V1:
Dave Kleikamp470decc2006-10-11 01:20:57 -07001164 journal->j_format_version = 1;
1165 break;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001166 case JBD2_SUPERBLOCK_V2:
Dave Kleikamp470decc2006-10-11 01:20:57 -07001167 journal->j_format_version = 2;
1168 break;
1169 default:
1170 printk(KERN_WARNING "JBD: unrecognised superblock format ID\n");
1171 goto out;
1172 }
1173
1174 if (be32_to_cpu(sb->s_maxlen) < journal->j_maxlen)
1175 journal->j_maxlen = be32_to_cpu(sb->s_maxlen);
1176 else if (be32_to_cpu(sb->s_maxlen) > journal->j_maxlen) {
1177 printk (KERN_WARNING "JBD: journal file too short\n");
1178 goto out;
1179 }
1180
1181 return 0;
1182
1183out:
1184 journal_fail_superblock(journal);
1185 return err;
1186}
1187
1188/*
1189 * Load the on-disk journal superblock and read the key fields into the
1190 * journal_t.
1191 */
1192
1193static int load_superblock(journal_t *journal)
1194{
1195 int err;
1196 journal_superblock_t *sb;
1197
1198 err = journal_get_superblock(journal);
1199 if (err)
1200 return err;
1201
1202 sb = journal->j_superblock;
1203
1204 journal->j_tail_sequence = be32_to_cpu(sb->s_sequence);
1205 journal->j_tail = be32_to_cpu(sb->s_start);
1206 journal->j_first = be32_to_cpu(sb->s_first);
1207 journal->j_last = be32_to_cpu(sb->s_maxlen);
1208 journal->j_errno = be32_to_cpu(sb->s_errno);
1209
1210 return 0;
1211}
1212
1213
1214/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001215 * int jbd2_journal_load() - Read journal from disk.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001216 * @journal: Journal to act on.
1217 *
1218 * Given a journal_t structure which tells us which disk blocks contain
1219 * a journal, read the journal from disk to initialise the in-memory
1220 * structures.
1221 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001222int jbd2_journal_load(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001223{
1224 int err;
1225 journal_superblock_t *sb;
1226
1227 err = load_superblock(journal);
1228 if (err)
1229 return err;
1230
1231 sb = journal->j_superblock;
1232 /* If this is a V2 superblock, then we have to check the
1233 * features flags on it. */
1234
1235 if (journal->j_format_version >= 2) {
1236 if ((sb->s_feature_ro_compat &
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001237 ~cpu_to_be32(JBD2_KNOWN_ROCOMPAT_FEATURES)) ||
Dave Kleikamp470decc2006-10-11 01:20:57 -07001238 (sb->s_feature_incompat &
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001239 ~cpu_to_be32(JBD2_KNOWN_INCOMPAT_FEATURES))) {
Dave Kleikamp470decc2006-10-11 01:20:57 -07001240 printk (KERN_WARNING
1241 "JBD: Unrecognised features on journal\n");
1242 return -EINVAL;
1243 }
1244 }
1245
Dave Kleikamp470decc2006-10-11 01:20:57 -07001246 /* Let the recovery code check whether it needs to recover any
1247 * data from the journal. */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001248 if (jbd2_journal_recover(journal))
Dave Kleikamp470decc2006-10-11 01:20:57 -07001249 goto recovery_error;
1250
1251 /* OK, we've finished with the dynamic journal bits:
1252 * reinitialise the dynamic contents of the superblock in memory
1253 * and reset them on disk. */
1254 if (journal_reset(journal))
1255 goto recovery_error;
1256
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001257 journal->j_flags &= ~JBD2_ABORT;
1258 journal->j_flags |= JBD2_LOADED;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001259 return 0;
1260
1261recovery_error:
1262 printk (KERN_WARNING "JBD: recovery failed\n");
1263 return -EIO;
1264}
1265
1266/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001267 * void jbd2_journal_destroy() - Release a journal_t structure.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001268 * @journal: Journal to act on.
1269 *
1270 * Release a journal_t structure once it is no longer in use by the
1271 * journaled object.
Hidehiro Kawai44519fa2008-10-10 20:29:13 -04001272 * Return <0 if we couldn't clean up the journal.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001273 */
Hidehiro Kawai44519fa2008-10-10 20:29:13 -04001274int jbd2_journal_destroy(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001275{
Hidehiro Kawai44519fa2008-10-10 20:29:13 -04001276 int err = 0;
1277
Dave Kleikamp470decc2006-10-11 01:20:57 -07001278 /* Wait for the commit thread to wake up and die. */
1279 journal_kill_thread(journal);
1280
1281 /* Force a final log commit */
1282 if (journal->j_running_transaction)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001283 jbd2_journal_commit_transaction(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001284
1285 /* Force any old transactions to disk */
1286
1287 /* Totally anal locking here... */
1288 spin_lock(&journal->j_list_lock);
1289 while (journal->j_checkpoint_transactions != NULL) {
1290 spin_unlock(&journal->j_list_lock);
Theodore Ts'o1a0d3782008-11-05 00:09:22 -05001291 mutex_lock(&journal->j_checkpoint_mutex);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001292 jbd2_log_do_checkpoint(journal);
Theodore Ts'o1a0d3782008-11-05 00:09:22 -05001293 mutex_unlock(&journal->j_checkpoint_mutex);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001294 spin_lock(&journal->j_list_lock);
1295 }
1296
1297 J_ASSERT(journal->j_running_transaction == NULL);
1298 J_ASSERT(journal->j_committing_transaction == NULL);
1299 J_ASSERT(journal->j_checkpoint_transactions == NULL);
1300 spin_unlock(&journal->j_list_lock);
1301
Dave Kleikamp470decc2006-10-11 01:20:57 -07001302 if (journal->j_sb_buffer) {
Hidehiro Kawai44519fa2008-10-10 20:29:13 -04001303 if (!is_journal_aborted(journal)) {
1304 /* We can now mark the journal as empty. */
1305 journal->j_tail = 0;
1306 journal->j_tail_sequence =
1307 ++journal->j_transaction_sequence;
1308 jbd2_journal_update_superblock(journal, 1);
1309 } else {
1310 err = -EIO;
1311 }
Dave Kleikamp470decc2006-10-11 01:20:57 -07001312 brelse(journal->j_sb_buffer);
1313 }
1314
Johann Lombardi8e85fb32008-01-28 23:58:27 -05001315 if (journal->j_proc_entry)
1316 jbd2_stats_proc_exit(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001317 if (journal->j_inode)
1318 iput(journal->j_inode);
1319 if (journal->j_revoke)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001320 jbd2_journal_destroy_revoke(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001321 kfree(journal->j_wbuf);
1322 kfree(journal);
Hidehiro Kawai44519fa2008-10-10 20:29:13 -04001323
1324 return err;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001325}
1326
1327
1328/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001329 *int jbd2_journal_check_used_features () - Check if features specified are used.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001330 * @journal: Journal to check.
1331 * @compat: bitmask of compatible features
1332 * @ro: bitmask of features that force read-only mount
1333 * @incompat: bitmask of incompatible features
1334 *
1335 * Check whether the journal uses all of a given set of
1336 * features. Return true (non-zero) if it does.
1337 **/
1338
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001339int jbd2_journal_check_used_features (journal_t *journal, unsigned long compat,
Dave Kleikamp470decc2006-10-11 01:20:57 -07001340 unsigned long ro, unsigned long incompat)
1341{
1342 journal_superblock_t *sb;
1343
1344 if (!compat && !ro && !incompat)
1345 return 1;
1346 if (journal->j_format_version == 1)
1347 return 0;
1348
1349 sb = journal->j_superblock;
1350
1351 if (((be32_to_cpu(sb->s_feature_compat) & compat) == compat) &&
1352 ((be32_to_cpu(sb->s_feature_ro_compat) & ro) == ro) &&
1353 ((be32_to_cpu(sb->s_feature_incompat) & incompat) == incompat))
1354 return 1;
1355
1356 return 0;
1357}
1358
1359/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001360 * int jbd2_journal_check_available_features() - Check feature set in journalling layer
Dave Kleikamp470decc2006-10-11 01:20:57 -07001361 * @journal: Journal to check.
1362 * @compat: bitmask of compatible features
1363 * @ro: bitmask of features that force read-only mount
1364 * @incompat: bitmask of incompatible features
1365 *
1366 * Check whether the journaling code supports the use of
1367 * all of a given set of features on this journal. Return true
1368 * (non-zero) if it can. */
1369
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001370int jbd2_journal_check_available_features (journal_t *journal, unsigned long compat,
Dave Kleikamp470decc2006-10-11 01:20:57 -07001371 unsigned long ro, unsigned long incompat)
1372{
1373 journal_superblock_t *sb;
1374
1375 if (!compat && !ro && !incompat)
1376 return 1;
1377
1378 sb = journal->j_superblock;
1379
1380 /* We can support any known requested features iff the
1381 * superblock is in version 2. Otherwise we fail to support any
1382 * extended sb features. */
1383
1384 if (journal->j_format_version != 2)
1385 return 0;
1386
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001387 if ((compat & JBD2_KNOWN_COMPAT_FEATURES) == compat &&
1388 (ro & JBD2_KNOWN_ROCOMPAT_FEATURES) == ro &&
1389 (incompat & JBD2_KNOWN_INCOMPAT_FEATURES) == incompat)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001390 return 1;
1391
1392 return 0;
1393}
1394
1395/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001396 * int jbd2_journal_set_features () - Mark a given journal feature in the superblock
Dave Kleikamp470decc2006-10-11 01:20:57 -07001397 * @journal: Journal to act on.
1398 * @compat: bitmask of compatible features
1399 * @ro: bitmask of features that force read-only mount
1400 * @incompat: bitmask of incompatible features
1401 *
1402 * Mark a given journal feature as present on the
1403 * superblock. Returns true if the requested features could be set.
1404 *
1405 */
1406
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001407int jbd2_journal_set_features (journal_t *journal, unsigned long compat,
Dave Kleikamp470decc2006-10-11 01:20:57 -07001408 unsigned long ro, unsigned long incompat)
1409{
1410 journal_superblock_t *sb;
1411
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001412 if (jbd2_journal_check_used_features(journal, compat, ro, incompat))
Dave Kleikamp470decc2006-10-11 01:20:57 -07001413 return 1;
1414
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001415 if (!jbd2_journal_check_available_features(journal, compat, ro, incompat))
Dave Kleikamp470decc2006-10-11 01:20:57 -07001416 return 0;
1417
1418 jbd_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n",
1419 compat, ro, incompat);
1420
1421 sb = journal->j_superblock;
1422
1423 sb->s_feature_compat |= cpu_to_be32(compat);
1424 sb->s_feature_ro_compat |= cpu_to_be32(ro);
1425 sb->s_feature_incompat |= cpu_to_be32(incompat);
1426
1427 return 1;
1428}
1429
Girish Shilamkar818d2762008-01-28 23:58:27 -05001430/*
1431 * jbd2_journal_clear_features () - Clear a given journal feature in the
1432 * superblock
1433 * @journal: Journal to act on.
1434 * @compat: bitmask of compatible features
1435 * @ro: bitmask of features that force read-only mount
1436 * @incompat: bitmask of incompatible features
1437 *
1438 * Clear a given journal feature as present on the
1439 * superblock.
1440 */
1441void jbd2_journal_clear_features(journal_t *journal, unsigned long compat,
1442 unsigned long ro, unsigned long incompat)
1443{
1444 journal_superblock_t *sb;
1445
1446 jbd_debug(1, "Clear features 0x%lx/0x%lx/0x%lx\n",
1447 compat, ro, incompat);
1448
1449 sb = journal->j_superblock;
1450
1451 sb->s_feature_compat &= ~cpu_to_be32(compat);
1452 sb->s_feature_ro_compat &= ~cpu_to_be32(ro);
1453 sb->s_feature_incompat &= ~cpu_to_be32(incompat);
1454}
1455EXPORT_SYMBOL(jbd2_journal_clear_features);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001456
1457/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001458 * int jbd2_journal_update_format () - Update on-disk journal structure.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001459 * @journal: Journal to act on.
1460 *
1461 * Given an initialised but unloaded journal struct, poke about in the
1462 * on-disk structure to update it to the most recent supported version.
1463 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001464int jbd2_journal_update_format (journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001465{
1466 journal_superblock_t *sb;
1467 int err;
1468
1469 err = journal_get_superblock(journal);
1470 if (err)
1471 return err;
1472
1473 sb = journal->j_superblock;
1474
1475 switch (be32_to_cpu(sb->s_header.h_blocktype)) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001476 case JBD2_SUPERBLOCK_V2:
Dave Kleikamp470decc2006-10-11 01:20:57 -07001477 return 0;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001478 case JBD2_SUPERBLOCK_V1:
Dave Kleikamp470decc2006-10-11 01:20:57 -07001479 return journal_convert_superblock_v1(journal, sb);
1480 default:
1481 break;
1482 }
1483 return -EINVAL;
1484}
1485
1486static int journal_convert_superblock_v1(journal_t *journal,
1487 journal_superblock_t *sb)
1488{
1489 int offset, blocksize;
1490 struct buffer_head *bh;
1491
1492 printk(KERN_WARNING
1493 "JBD: Converting superblock from version 1 to 2.\n");
1494
1495 /* Pre-initialise new fields to zero */
1496 offset = ((char *) &(sb->s_feature_compat)) - ((char *) sb);
1497 blocksize = be32_to_cpu(sb->s_blocksize);
1498 memset(&sb->s_feature_compat, 0, blocksize-offset);
1499
1500 sb->s_nr_users = cpu_to_be32(1);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001501 sb->s_header.h_blocktype = cpu_to_be32(JBD2_SUPERBLOCK_V2);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001502 journal->j_format_version = 2;
1503
1504 bh = journal->j_sb_buffer;
1505 BUFFER_TRACE(bh, "marking dirty");
1506 mark_buffer_dirty(bh);
1507 sync_dirty_buffer(bh);
1508 return 0;
1509}
1510
1511
1512/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001513 * int jbd2_journal_flush () - Flush journal
Dave Kleikamp470decc2006-10-11 01:20:57 -07001514 * @journal: Journal to act on.
1515 *
1516 * Flush all data for a given journal to disk and empty the journal.
1517 * Filesystems can use this when remounting readonly to ensure that
1518 * recovery does not need to happen on remount.
1519 */
1520
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001521int jbd2_journal_flush(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001522{
1523 int err = 0;
1524 transaction_t *transaction = NULL;
1525 unsigned long old_tail;
1526
1527 spin_lock(&journal->j_state_lock);
1528
1529 /* Force everything buffered to the log... */
1530 if (journal->j_running_transaction) {
1531 transaction = journal->j_running_transaction;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001532 __jbd2_log_start_commit(journal, transaction->t_tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001533 } else if (journal->j_committing_transaction)
1534 transaction = journal->j_committing_transaction;
1535
1536 /* Wait for the log commit to complete... */
1537 if (transaction) {
1538 tid_t tid = transaction->t_tid;
1539
1540 spin_unlock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001541 jbd2_log_wait_commit(journal, tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001542 } else {
1543 spin_unlock(&journal->j_state_lock);
1544 }
1545
1546 /* ...and flush everything in the log out to disk. */
1547 spin_lock(&journal->j_list_lock);
1548 while (!err && journal->j_checkpoint_transactions != NULL) {
1549 spin_unlock(&journal->j_list_lock);
Hidehiro Kawai44519fa2008-10-10 20:29:13 -04001550 mutex_lock(&journal->j_checkpoint_mutex);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001551 err = jbd2_log_do_checkpoint(journal);
Hidehiro Kawai44519fa2008-10-10 20:29:13 -04001552 mutex_unlock(&journal->j_checkpoint_mutex);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001553 spin_lock(&journal->j_list_lock);
1554 }
1555 spin_unlock(&journal->j_list_lock);
Hidehiro Kawai44519fa2008-10-10 20:29:13 -04001556
1557 if (is_journal_aborted(journal))
1558 return -EIO;
1559
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001560 jbd2_cleanup_journal_tail(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001561
1562 /* Finally, mark the journal as really needing no recovery.
1563 * This sets s_start==0 in the underlying superblock, which is
1564 * the magic code for a fully-recovered superblock. Any future
1565 * commits of data to the journal will restore the current
1566 * s_start value. */
1567 spin_lock(&journal->j_state_lock);
1568 old_tail = journal->j_tail;
1569 journal->j_tail = 0;
1570 spin_unlock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001571 jbd2_journal_update_superblock(journal, 1);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001572 spin_lock(&journal->j_state_lock);
1573 journal->j_tail = old_tail;
1574
1575 J_ASSERT(!journal->j_running_transaction);
1576 J_ASSERT(!journal->j_committing_transaction);
1577 J_ASSERT(!journal->j_checkpoint_transactions);
1578 J_ASSERT(journal->j_head == journal->j_tail);
1579 J_ASSERT(journal->j_tail_sequence == journal->j_transaction_sequence);
1580 spin_unlock(&journal->j_state_lock);
Hidehiro Kawai44519fa2008-10-10 20:29:13 -04001581 return 0;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001582}
1583
1584/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001585 * int jbd2_journal_wipe() - Wipe journal contents
Dave Kleikamp470decc2006-10-11 01:20:57 -07001586 * @journal: Journal to act on.
1587 * @write: flag (see below)
1588 *
1589 * Wipe out all of the contents of a journal, safely. This will produce
1590 * a warning if the journal contains any valid recovery information.
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001591 * Must be called between journal_init_*() and jbd2_journal_load().
Dave Kleikamp470decc2006-10-11 01:20:57 -07001592 *
1593 * If 'write' is non-zero, then we wipe out the journal on disk; otherwise
1594 * we merely suppress recovery.
1595 */
1596
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001597int jbd2_journal_wipe(journal_t *journal, int write)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001598{
1599 journal_superblock_t *sb;
1600 int err = 0;
1601
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001602 J_ASSERT (!(journal->j_flags & JBD2_LOADED));
Dave Kleikamp470decc2006-10-11 01:20:57 -07001603
1604 err = load_superblock(journal);
1605 if (err)
1606 return err;
1607
1608 sb = journal->j_superblock;
1609
1610 if (!journal->j_tail)
1611 goto no_recovery;
1612
1613 printk (KERN_WARNING "JBD: %s recovery information on journal\n",
1614 write ? "Clearing" : "Ignoring");
1615
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001616 err = jbd2_journal_skip_recovery(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001617 if (write)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001618 jbd2_journal_update_superblock(journal, 1);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001619
1620 no_recovery:
1621 return err;
1622}
1623
1624/*
Dave Kleikamp470decc2006-10-11 01:20:57 -07001625 * Journal abort has very specific semantics, which we describe
1626 * for journal abort.
1627 *
Alberto Bertoglibfcd3552009-06-09 00:06:20 -04001628 * Two internal functions, which provide abort to the jbd layer
Dave Kleikamp470decc2006-10-11 01:20:57 -07001629 * itself are here.
1630 */
1631
1632/*
1633 * Quick version for internal journal use (doesn't lock the journal).
1634 * Aborts hard --- we mark the abort as occurred, but do _nothing_ else,
1635 * and don't attempt to make any other journal updates.
1636 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001637void __jbd2_journal_abort_hard(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001638{
1639 transaction_t *transaction;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001640
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001641 if (journal->j_flags & JBD2_ABORT)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001642 return;
1643
1644 printk(KERN_ERR "Aborting journal on device %s.\n",
Theodore Ts'o05496762008-09-16 14:36:17 -04001645 journal->j_devname);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001646
1647 spin_lock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001648 journal->j_flags |= JBD2_ABORT;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001649 transaction = journal->j_running_transaction;
1650 if (transaction)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001651 __jbd2_log_start_commit(journal, transaction->t_tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001652 spin_unlock(&journal->j_state_lock);
1653}
1654
1655/* Soft abort: record the abort error status in the journal superblock,
1656 * but don't do any other IO. */
1657static void __journal_abort_soft (journal_t *journal, int errno)
1658{
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001659 if (journal->j_flags & JBD2_ABORT)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001660 return;
1661
1662 if (!journal->j_errno)
1663 journal->j_errno = errno;
1664
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001665 __jbd2_journal_abort_hard(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001666
1667 if (errno)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001668 jbd2_journal_update_superblock(journal, 1);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001669}
1670
1671/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001672 * void jbd2_journal_abort () - Shutdown the journal immediately.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001673 * @journal: the journal to shutdown.
1674 * @errno: an error number to record in the journal indicating
1675 * the reason for the shutdown.
1676 *
1677 * Perform a complete, immediate shutdown of the ENTIRE
1678 * journal (not of a single transaction). This operation cannot be
1679 * undone without closing and reopening the journal.
1680 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001681 * The jbd2_journal_abort function is intended to support higher level error
Dave Kleikamp470decc2006-10-11 01:20:57 -07001682 * recovery mechanisms such as the ext2/ext3 remount-readonly error
1683 * mode.
1684 *
1685 * Journal abort has very specific semantics. Any existing dirty,
1686 * unjournaled buffers in the main filesystem will still be written to
1687 * disk by bdflush, but the journaling mechanism will be suspended
1688 * immediately and no further transaction commits will be honoured.
1689 *
1690 * Any dirty, journaled buffers will be written back to disk without
1691 * hitting the journal. Atomicity cannot be guaranteed on an aborted
1692 * filesystem, but we _do_ attempt to leave as much data as possible
1693 * behind for fsck to use for cleanup.
1694 *
1695 * Any attempt to get a new transaction handle on a journal which is in
1696 * ABORT state will just result in an -EROFS error return. A
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001697 * jbd2_journal_stop on an existing handle will return -EIO if we have
Dave Kleikamp470decc2006-10-11 01:20:57 -07001698 * entered abort state during the update.
1699 *
1700 * Recursive transactions are not disturbed by journal abort until the
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001701 * final jbd2_journal_stop, which will receive the -EIO error.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001702 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001703 * Finally, the jbd2_journal_abort call allows the caller to supply an errno
Dave Kleikamp470decc2006-10-11 01:20:57 -07001704 * which will be recorded (if possible) in the journal superblock. This
1705 * allows a client to record failure conditions in the middle of a
1706 * transaction without having to complete the transaction to record the
1707 * failure to disk. ext3_error, for example, now uses this
1708 * functionality.
1709 *
1710 * Errors which originate from within the journaling layer will NOT
1711 * supply an errno; a null errno implies that absolutely no further
1712 * writes are done to the journal (unless there are any already in
1713 * progress).
1714 *
1715 */
1716
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001717void jbd2_journal_abort(journal_t *journal, int errno)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001718{
1719 __journal_abort_soft(journal, errno);
1720}
1721
1722/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001723 * int jbd2_journal_errno () - returns the journal's error state.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001724 * @journal: journal to examine.
1725 *
Alberto Bertoglibfcd3552009-06-09 00:06:20 -04001726 * This is the errno number set with jbd2_journal_abort(), the last
Dave Kleikamp470decc2006-10-11 01:20:57 -07001727 * time the journal was mounted - if the journal was stopped
1728 * without calling abort this will be 0.
1729 *
1730 * If the journal has been aborted on this mount time -EROFS will
1731 * be returned.
1732 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001733int jbd2_journal_errno(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001734{
1735 int err;
1736
1737 spin_lock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001738 if (journal->j_flags & JBD2_ABORT)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001739 err = -EROFS;
1740 else
1741 err = journal->j_errno;
1742 spin_unlock(&journal->j_state_lock);
1743 return err;
1744}
1745
1746/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001747 * int jbd2_journal_clear_err () - clears the journal's error state
Dave Kleikamp470decc2006-10-11 01:20:57 -07001748 * @journal: journal to act on.
1749 *
Alberto Bertoglibfcd3552009-06-09 00:06:20 -04001750 * An error must be cleared or acked to take a FS out of readonly
Dave Kleikamp470decc2006-10-11 01:20:57 -07001751 * mode.
1752 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001753int jbd2_journal_clear_err(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001754{
1755 int err = 0;
1756
1757 spin_lock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001758 if (journal->j_flags & JBD2_ABORT)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001759 err = -EROFS;
1760 else
1761 journal->j_errno = 0;
1762 spin_unlock(&journal->j_state_lock);
1763 return err;
1764}
1765
1766/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001767 * void jbd2_journal_ack_err() - Ack journal err.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001768 * @journal: journal to act on.
1769 *
Alberto Bertoglibfcd3552009-06-09 00:06:20 -04001770 * An error must be cleared or acked to take a FS out of readonly
Dave Kleikamp470decc2006-10-11 01:20:57 -07001771 * mode.
1772 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001773void jbd2_journal_ack_err(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001774{
1775 spin_lock(&journal->j_state_lock);
1776 if (journal->j_errno)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001777 journal->j_flags |= JBD2_ACK_ERR;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001778 spin_unlock(&journal->j_state_lock);
1779}
1780
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001781int jbd2_journal_blocks_per_page(struct inode *inode)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001782{
1783 return 1 << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
1784}
1785
1786/*
Zach Brownb517bea2006-10-11 01:21:08 -07001787 * helper functions to deal with 32 or 64bit block numbers.
1788 */
1789size_t journal_tag_bytes(journal_t *journal)
1790{
1791 if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT))
Mingming Caocd02ff02007-10-16 18:38:25 -04001792 return JBD2_TAG_SIZE64;
Zach Brownb517bea2006-10-11 01:21:08 -07001793 else
Mingming Caocd02ff02007-10-16 18:38:25 -04001794 return JBD2_TAG_SIZE32;
Zach Brownb517bea2006-10-11 01:21:08 -07001795}
1796
1797/*
Dave Kleikamp470decc2006-10-11 01:20:57 -07001798 * Journal_head storage management
1799 */
Christoph Lametere18b8902006-12-06 20:33:20 -08001800static struct kmem_cache *jbd2_journal_head_cache;
Jose R. Santose23291b2007-07-18 08:57:06 -04001801#ifdef CONFIG_JBD2_DEBUG
Dave Kleikamp470decc2006-10-11 01:20:57 -07001802static atomic_t nr_journal_heads = ATOMIC_INIT(0);
1803#endif
1804
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001805static int journal_init_jbd2_journal_head_cache(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001806{
1807 int retval;
1808
Al Viro1076d172008-03-29 03:07:18 +00001809 J_ASSERT(jbd2_journal_head_cache == NULL);
Johann Lombardia920e942006-10-11 01:21:00 -07001810 jbd2_journal_head_cache = kmem_cache_create("jbd2_journal_head",
Dave Kleikamp470decc2006-10-11 01:20:57 -07001811 sizeof(struct journal_head),
1812 0, /* offset */
Mingming Cao77160952008-01-28 23:58:27 -05001813 SLAB_TEMPORARY, /* flags */
Paul Mundt20c2df82007-07-20 10:11:58 +09001814 NULL); /* ctor */
Dave Kleikamp470decc2006-10-11 01:20:57 -07001815 retval = 0;
Al Viro1076d172008-03-29 03:07:18 +00001816 if (!jbd2_journal_head_cache) {
Dave Kleikamp470decc2006-10-11 01:20:57 -07001817 retval = -ENOMEM;
1818 printk(KERN_EMERG "JBD: no memory for journal_head cache\n");
1819 }
1820 return retval;
1821}
1822
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001823static void jbd2_journal_destroy_jbd2_journal_head_cache(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001824{
Duane Griffin8a9362e2008-04-17 10:38:59 -04001825 if (jbd2_journal_head_cache) {
1826 kmem_cache_destroy(jbd2_journal_head_cache);
1827 jbd2_journal_head_cache = NULL;
1828 }
Dave Kleikamp470decc2006-10-11 01:20:57 -07001829}
1830
1831/*
1832 * journal_head splicing and dicing
1833 */
1834static struct journal_head *journal_alloc_journal_head(void)
1835{
1836 struct journal_head *ret;
1837 static unsigned long last_warning;
1838
Jose R. Santose23291b2007-07-18 08:57:06 -04001839#ifdef CONFIG_JBD2_DEBUG
Dave Kleikamp470decc2006-10-11 01:20:57 -07001840 atomic_inc(&nr_journal_heads);
1841#endif
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001842 ret = kmem_cache_alloc(jbd2_journal_head_cache, GFP_NOFS);
Al Viro1076d172008-03-29 03:07:18 +00001843 if (!ret) {
Dave Kleikamp470decc2006-10-11 01:20:57 -07001844 jbd_debug(1, "out of memory for journal_head\n");
1845 if (time_after(jiffies, last_warning + 5*HZ)) {
1846 printk(KERN_NOTICE "ENOMEM in %s, retrying.\n",
Harvey Harrison329d2912008-04-17 10:38:59 -04001847 __func__);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001848 last_warning = jiffies;
1849 }
Al Viro1076d172008-03-29 03:07:18 +00001850 while (!ret) {
Dave Kleikamp470decc2006-10-11 01:20:57 -07001851 yield();
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001852 ret = kmem_cache_alloc(jbd2_journal_head_cache, GFP_NOFS);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001853 }
1854 }
1855 return ret;
1856}
1857
1858static void journal_free_journal_head(struct journal_head *jh)
1859{
Jose R. Santose23291b2007-07-18 08:57:06 -04001860#ifdef CONFIG_JBD2_DEBUG
Dave Kleikamp470decc2006-10-11 01:20:57 -07001861 atomic_dec(&nr_journal_heads);
Mingming Caocd02ff02007-10-16 18:38:25 -04001862 memset(jh, JBD2_POISON_FREE, sizeof(*jh));
Dave Kleikamp470decc2006-10-11 01:20:57 -07001863#endif
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001864 kmem_cache_free(jbd2_journal_head_cache, jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001865}
1866
1867/*
1868 * A journal_head is attached to a buffer_head whenever JBD has an
1869 * interest in the buffer.
1870 *
1871 * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit
1872 * is set. This bit is tested in core kernel code where we need to take
1873 * JBD-specific actions. Testing the zeroness of ->b_private is not reliable
1874 * there.
1875 *
1876 * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one.
1877 *
1878 * When a buffer has its BH_JBD bit set it is immune from being released by
1879 * core kernel code, mainly via ->b_count.
1880 *
1881 * A journal_head may be detached from its buffer_head when the journal_head's
1882 * b_transaction, b_cp_transaction and b_next_transaction pointers are NULL.
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001883 * Various places in JBD call jbd2_journal_remove_journal_head() to indicate that the
Dave Kleikamp470decc2006-10-11 01:20:57 -07001884 * journal_head can be dropped if needed.
1885 *
1886 * Various places in the kernel want to attach a journal_head to a buffer_head
1887 * _before_ attaching the journal_head to a transaction. To protect the
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001888 * journal_head in this situation, jbd2_journal_add_journal_head elevates the
Dave Kleikamp470decc2006-10-11 01:20:57 -07001889 * journal_head's b_jcount refcount by one. The caller must call
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001890 * jbd2_journal_put_journal_head() to undo this.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001891 *
1892 * So the typical usage would be:
1893 *
1894 * (Attach a journal_head if needed. Increments b_jcount)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001895 * struct journal_head *jh = jbd2_journal_add_journal_head(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001896 * ...
1897 * jh->b_transaction = xxx;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001898 * jbd2_journal_put_journal_head(jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001899 *
1900 * Now, the journal_head's b_jcount is zero, but it is safe from being released
1901 * because it has a non-zero b_transaction.
1902 */
1903
1904/*
1905 * Give a buffer_head a journal_head.
1906 *
1907 * Doesn't need the journal lock.
1908 * May sleep.
1909 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001910struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001911{
1912 struct journal_head *jh;
1913 struct journal_head *new_jh = NULL;
1914
1915repeat:
1916 if (!buffer_jbd(bh)) {
1917 new_jh = journal_alloc_journal_head();
1918 memset(new_jh, 0, sizeof(*new_jh));
1919 }
1920
1921 jbd_lock_bh_journal_head(bh);
1922 if (buffer_jbd(bh)) {
1923 jh = bh2jh(bh);
1924 } else {
1925 J_ASSERT_BH(bh,
1926 (atomic_read(&bh->b_count) > 0) ||
1927 (bh->b_page && bh->b_page->mapping));
1928
1929 if (!new_jh) {
1930 jbd_unlock_bh_journal_head(bh);
1931 goto repeat;
1932 }
1933
1934 jh = new_jh;
1935 new_jh = NULL; /* We consumed it */
1936 set_buffer_jbd(bh);
1937 bh->b_private = jh;
1938 jh->b_bh = bh;
1939 get_bh(bh);
1940 BUFFER_TRACE(bh, "added journal_head");
1941 }
1942 jh->b_jcount++;
1943 jbd_unlock_bh_journal_head(bh);
1944 if (new_jh)
1945 journal_free_journal_head(new_jh);
1946 return bh->b_private;
1947}
1948
1949/*
1950 * Grab a ref against this buffer_head's journal_head. If it ended up not
1951 * having a journal_head, return NULL
1952 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001953struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001954{
1955 struct journal_head *jh = NULL;
1956
1957 jbd_lock_bh_journal_head(bh);
1958 if (buffer_jbd(bh)) {
1959 jh = bh2jh(bh);
1960 jh->b_jcount++;
1961 }
1962 jbd_unlock_bh_journal_head(bh);
1963 return jh;
1964}
1965
1966static void __journal_remove_journal_head(struct buffer_head *bh)
1967{
1968 struct journal_head *jh = bh2jh(bh);
1969
1970 J_ASSERT_JH(jh, jh->b_jcount >= 0);
1971
1972 get_bh(bh);
1973 if (jh->b_jcount == 0) {
1974 if (jh->b_transaction == NULL &&
1975 jh->b_next_transaction == NULL &&
1976 jh->b_cp_transaction == NULL) {
1977 J_ASSERT_JH(jh, jh->b_jlist == BJ_None);
1978 J_ASSERT_BH(bh, buffer_jbd(bh));
1979 J_ASSERT_BH(bh, jh2bh(jh) == bh);
1980 BUFFER_TRACE(bh, "remove journal_head");
1981 if (jh->b_frozen_data) {
1982 printk(KERN_WARNING "%s: freeing "
1983 "b_frozen_data\n",
Harvey Harrison329d2912008-04-17 10:38:59 -04001984 __func__);
Mingming Caoaf1e76d2007-10-16 18:38:25 -04001985 jbd2_free(jh->b_frozen_data, bh->b_size);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001986 }
1987 if (jh->b_committed_data) {
1988 printk(KERN_WARNING "%s: freeing "
1989 "b_committed_data\n",
Harvey Harrison329d2912008-04-17 10:38:59 -04001990 __func__);
Mingming Caoaf1e76d2007-10-16 18:38:25 -04001991 jbd2_free(jh->b_committed_data, bh->b_size);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001992 }
1993 bh->b_private = NULL;
1994 jh->b_bh = NULL; /* debug, really */
1995 clear_buffer_jbd(bh);
1996 __brelse(bh);
1997 journal_free_journal_head(jh);
1998 } else {
1999 BUFFER_TRACE(bh, "journal_head was locked");
2000 }
2001 }
2002}
2003
2004/*
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002005 * jbd2_journal_remove_journal_head(): if the buffer isn't attached to a transaction
Dave Kleikamp470decc2006-10-11 01:20:57 -07002006 * and has a zero b_jcount then remove and release its journal_head. If we did
2007 * see that the buffer is not used by any transaction we also "logically"
2008 * decrement ->b_count.
2009 *
2010 * We in fact take an additional increment on ->b_count as a convenience,
2011 * because the caller usually wants to do additional things with the bh
2012 * after calling here.
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002013 * The caller of jbd2_journal_remove_journal_head() *must* run __brelse(bh) at some
Dave Kleikamp470decc2006-10-11 01:20:57 -07002014 * time. Once the caller has run __brelse(), the buffer is eligible for
2015 * reaping by try_to_free_buffers().
2016 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002017void jbd2_journal_remove_journal_head(struct buffer_head *bh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07002018{
2019 jbd_lock_bh_journal_head(bh);
2020 __journal_remove_journal_head(bh);
2021 jbd_unlock_bh_journal_head(bh);
2022}
2023
2024/*
2025 * Drop a reference on the passed journal_head. If it fell to zero then try to
2026 * release the journal_head from the buffer_head.
2027 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002028void jbd2_journal_put_journal_head(struct journal_head *jh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07002029{
2030 struct buffer_head *bh = jh2bh(jh);
2031
2032 jbd_lock_bh_journal_head(bh);
2033 J_ASSERT_JH(jh, jh->b_jcount > 0);
2034 --jh->b_jcount;
2035 if (!jh->b_jcount && !jh->b_transaction) {
2036 __journal_remove_journal_head(bh);
2037 __brelse(bh);
2038 }
2039 jbd_unlock_bh_journal_head(bh);
2040}
2041
2042/*
Jan Karac851ed52008-07-11 19:27:31 -04002043 * Initialize jbd inode head
2044 */
2045void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode)
2046{
2047 jinode->i_transaction = NULL;
2048 jinode->i_next_transaction = NULL;
2049 jinode->i_vfs_inode = inode;
2050 jinode->i_flags = 0;
2051 INIT_LIST_HEAD(&jinode->i_list);
2052}
2053
2054/*
2055 * Function to be called before we start removing inode from memory (i.e.,
2056 * clear_inode() is a fine place to be called from). It removes inode from
2057 * transaction's lists.
2058 */
2059void jbd2_journal_release_jbd_inode(journal_t *journal,
2060 struct jbd2_inode *jinode)
2061{
2062 int writeout = 0;
2063
2064 if (!journal)
2065 return;
2066restart:
2067 spin_lock(&journal->j_list_lock);
2068 /* Is commit writing out inode - we have to wait */
2069 if (jinode->i_flags & JI_COMMIT_RUNNING) {
2070 wait_queue_head_t *wq;
2071 DEFINE_WAIT_BIT(wait, &jinode->i_flags, __JI_COMMIT_RUNNING);
2072 wq = bit_waitqueue(&jinode->i_flags, __JI_COMMIT_RUNNING);
2073 prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE);
2074 spin_unlock(&journal->j_list_lock);
2075 schedule();
2076 finish_wait(wq, &wait.wait);
2077 goto restart;
2078 }
2079
2080 /* Do we need to wait for data writeback? */
2081 if (journal->j_committing_transaction == jinode->i_transaction)
2082 writeout = 1;
2083 if (jinode->i_transaction) {
2084 list_del(&jinode->i_list);
2085 jinode->i_transaction = NULL;
2086 }
2087 spin_unlock(&journal->j_list_lock);
2088}
2089
2090/*
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002091 * debugfs tunables
Dave Kleikamp470decc2006-10-11 01:20:57 -07002092 */
Jose R. Santos6f38c742007-10-16 18:38:25 -04002093#ifdef CONFIG_JBD2_DEBUG
2094u8 jbd2_journal_enable_debug __read_mostly;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002095EXPORT_SYMBOL(jbd2_journal_enable_debug);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002096
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002097#define JBD2_DEBUG_NAME "jbd2-debug"
Dave Kleikamp470decc2006-10-11 01:20:57 -07002098
Jose R. Santos6f38c742007-10-16 18:38:25 -04002099static struct dentry *jbd2_debugfs_dir;
2100static struct dentry *jbd2_debug;
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002101
2102static void __init jbd2_create_debugfs_entry(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07002103{
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002104 jbd2_debugfs_dir = debugfs_create_dir("jbd2", NULL);
2105 if (jbd2_debugfs_dir)
2106 jbd2_debug = debugfs_create_u8(JBD2_DEBUG_NAME, S_IRUGO,
2107 jbd2_debugfs_dir,
2108 &jbd2_journal_enable_debug);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002109}
2110
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002111static void __exit jbd2_remove_debugfs_entry(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07002112{
Jose R. Santos6f38c742007-10-16 18:38:25 -04002113 debugfs_remove(jbd2_debug);
2114 debugfs_remove(jbd2_debugfs_dir);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002115}
2116
2117#else
2118
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002119static void __init jbd2_create_debugfs_entry(void)
2120{
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002121}
2122
2123static void __exit jbd2_remove_debugfs_entry(void)
2124{
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002125}
Dave Kleikamp470decc2006-10-11 01:20:57 -07002126
2127#endif
2128
Johann Lombardi8e85fb32008-01-28 23:58:27 -05002129#ifdef CONFIG_PROC_FS
2130
2131#define JBD2_STATS_PROC_NAME "fs/jbd2"
2132
2133static void __init jbd2_create_jbd_stats_proc_entry(void)
2134{
2135 proc_jbd2_stats = proc_mkdir(JBD2_STATS_PROC_NAME, NULL);
2136}
2137
2138static void __exit jbd2_remove_jbd_stats_proc_entry(void)
2139{
2140 if (proc_jbd2_stats)
2141 remove_proc_entry(JBD2_STATS_PROC_NAME, NULL);
2142}
2143
2144#else
2145
2146#define jbd2_create_jbd_stats_proc_entry() do {} while (0)
2147#define jbd2_remove_jbd_stats_proc_entry() do {} while (0)
2148
2149#endif
2150
Christoph Lametere18b8902006-12-06 20:33:20 -08002151struct kmem_cache *jbd2_handle_cache;
Dave Kleikamp470decc2006-10-11 01:20:57 -07002152
2153static int __init journal_init_handle_cache(void)
2154{
Johann Lombardia920e942006-10-11 01:21:00 -07002155 jbd2_handle_cache = kmem_cache_create("jbd2_journal_handle",
Dave Kleikamp470decc2006-10-11 01:20:57 -07002156 sizeof(handle_t),
2157 0, /* offset */
Mingming Cao77160952008-01-28 23:58:27 -05002158 SLAB_TEMPORARY, /* flags */
Paul Mundt20c2df82007-07-20 10:11:58 +09002159 NULL); /* ctor */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002160 if (jbd2_handle_cache == NULL) {
Dave Kleikamp470decc2006-10-11 01:20:57 -07002161 printk(KERN_EMERG "JBD: failed to create handle cache\n");
2162 return -ENOMEM;
2163 }
2164 return 0;
2165}
2166
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002167static void jbd2_journal_destroy_handle_cache(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07002168{
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002169 if (jbd2_handle_cache)
2170 kmem_cache_destroy(jbd2_handle_cache);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002171}
2172
2173/*
2174 * Module startup and shutdown
2175 */
2176
2177static int __init journal_init_caches(void)
2178{
2179 int ret;
2180
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002181 ret = jbd2_journal_init_revoke_caches();
Dave Kleikamp470decc2006-10-11 01:20:57 -07002182 if (ret == 0)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002183 ret = journal_init_jbd2_journal_head_cache();
Dave Kleikamp470decc2006-10-11 01:20:57 -07002184 if (ret == 0)
2185 ret = journal_init_handle_cache();
2186 return ret;
2187}
2188
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002189static void jbd2_journal_destroy_caches(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -07002190{
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002191 jbd2_journal_destroy_revoke_caches();
2192 jbd2_journal_destroy_jbd2_journal_head_cache();
2193 jbd2_journal_destroy_handle_cache();
Dave Kleikamp470decc2006-10-11 01:20:57 -07002194}
2195
2196static int __init journal_init(void)
2197{
2198 int ret;
2199
2200 BUILD_BUG_ON(sizeof(struct journal_superblock_s) != 1024);
2201
2202 ret = journal_init_caches();
Duane Griffin620de4e2008-04-29 22:02:47 -04002203 if (ret == 0) {
2204 jbd2_create_debugfs_entry();
2205 jbd2_create_jbd_stats_proc_entry();
2206 } else {
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002207 jbd2_journal_destroy_caches();
Duane Griffin620de4e2008-04-29 22:02:47 -04002208 }
Dave Kleikamp470decc2006-10-11 01:20:57 -07002209 return ret;
2210}
2211
2212static void __exit journal_exit(void)
2213{
Jose R. Santose23291b2007-07-18 08:57:06 -04002214#ifdef CONFIG_JBD2_DEBUG
Dave Kleikamp470decc2006-10-11 01:20:57 -07002215 int n = atomic_read(&nr_journal_heads);
2216 if (n)
2217 printk(KERN_EMERG "JBD: leaked %d journal_heads!\n", n);
2218#endif
Jose R. Santos0f49d5d2007-07-18 08:50:18 -04002219 jbd2_remove_debugfs_entry();
Johann Lombardi8e85fb32008-01-28 23:58:27 -05002220 jbd2_remove_jbd_stats_proc_entry();
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002221 jbd2_journal_destroy_caches();
Dave Kleikamp470decc2006-10-11 01:20:57 -07002222}
2223
Theodore Ts'o879c5e62009-06-17 11:47:48 -04002224/*
2225 * jbd2_dev_to_name is a utility function used by the jbd2 and ext4
2226 * tracing infrastructure to map a dev_t to a device name.
2227 *
2228 * The caller should use rcu_read_lock() in order to make sure the
2229 * device name stays valid until its done with it. We use
2230 * rcu_read_lock() as well to make sure we're safe in case the caller
2231 * gets sloppy, and because rcu_read_lock() is cheap and can be safely
2232 * nested.
2233 */
2234struct devname_cache {
2235 struct rcu_head rcu;
2236 dev_t device;
2237 char devname[BDEVNAME_SIZE];
2238};
2239#define CACHE_SIZE_BITS 6
2240static struct devname_cache *devcache[1 << CACHE_SIZE_BITS];
2241static DEFINE_SPINLOCK(devname_cache_lock);
2242
2243static void free_devcache(struct rcu_head *rcu)
2244{
2245 kfree(rcu);
2246}
2247
2248const char *jbd2_dev_to_name(dev_t device)
2249{
2250 int i = hash_32(device, CACHE_SIZE_BITS);
2251 char *ret;
2252 struct block_device *bd;
Theodore Ts'ob5744802009-06-20 23:34:44 -04002253 static struct devname_cache *new_dev;
Theodore Ts'o879c5e62009-06-17 11:47:48 -04002254
2255 rcu_read_lock();
2256 if (devcache[i] && devcache[i]->device == device) {
2257 ret = devcache[i]->devname;
2258 rcu_read_unlock();
2259 return ret;
2260 }
2261 rcu_read_unlock();
2262
Theodore Ts'ob5744802009-06-20 23:34:44 -04002263 new_dev = kmalloc(sizeof(struct devname_cache), GFP_KERNEL);
2264 if (!new_dev)
2265 return "NODEV-ALLOCFAILURE"; /* Something non-NULL */
Theodore Ts'o879c5e62009-06-17 11:47:48 -04002266 spin_lock(&devname_cache_lock);
2267 if (devcache[i]) {
2268 if (devcache[i]->device == device) {
Theodore Ts'ob5744802009-06-20 23:34:44 -04002269 kfree(new_dev);
Theodore Ts'o879c5e62009-06-17 11:47:48 -04002270 ret = devcache[i]->devname;
2271 spin_unlock(&devname_cache_lock);
2272 return ret;
2273 }
2274 call_rcu(&devcache[i]->rcu, free_devcache);
2275 }
Theodore Ts'ob5744802009-06-20 23:34:44 -04002276 devcache[i] = new_dev;
Theodore Ts'o879c5e62009-06-17 11:47:48 -04002277 devcache[i]->device = device;
2278 bd = bdget(device);
2279 if (bd) {
2280 bdevname(bd, devcache[i]->devname);
2281 bdput(bd);
2282 } else
2283 __bdevname(device, devcache[i]->devname);
2284 ret = devcache[i]->devname;
2285 spin_unlock(&devname_cache_lock);
2286 return ret;
2287}
2288EXPORT_SYMBOL(jbd2_dev_to_name);
2289
Dave Kleikamp470decc2006-10-11 01:20:57 -07002290MODULE_LICENSE("GPL");
2291module_init(journal_init);
2292module_exit(journal_exit);
2293