Commit | Line | Data |
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1da177e4 | 1 | /* |
f30c2269 | 2 | * linux/fs/jbd/journal.c |
1da177e4 LT |
3 | * |
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> | |
28 | #include <linux/jbd.h> | |
29 | #include <linux/errno.h> | |
30 | #include <linux/slab.h> | |
1da177e4 LT |
31 | #include <linux/init.h> |
32 | #include <linux/mm.h> | |
7dfb7103 | 33 | #include <linux/freezer.h> |
1da177e4 | 34 | #include <linux/pagemap.h> |
8d8c8511 | 35 | #include <linux/kthread.h> |
c9cf5528 | 36 | #include <linux/poison.h> |
8d8c8511 | 37 | #include <linux/proc_fs.h> |
c2a9159c | 38 | #include <linux/debugfs.h> |
f81e3d45 | 39 | #include <linux/ratelimit.h> |
8d8c8511 | 40 | |
99cb1a31 LC |
41 | #define CREATE_TRACE_POINTS |
42 | #include <trace/events/jbd.h> | |
43 | ||
1da177e4 LT |
44 | #include <asm/uaccess.h> |
45 | #include <asm/page.h> | |
1da177e4 LT |
46 | |
47 | EXPORT_SYMBOL(journal_start); | |
48 | EXPORT_SYMBOL(journal_restart); | |
49 | EXPORT_SYMBOL(journal_extend); | |
50 | EXPORT_SYMBOL(journal_stop); | |
51 | EXPORT_SYMBOL(journal_lock_updates); | |
52 | EXPORT_SYMBOL(journal_unlock_updates); | |
53 | EXPORT_SYMBOL(journal_get_write_access); | |
54 | EXPORT_SYMBOL(journal_get_create_access); | |
55 | EXPORT_SYMBOL(journal_get_undo_access); | |
56 | EXPORT_SYMBOL(journal_dirty_data); | |
57 | EXPORT_SYMBOL(journal_dirty_metadata); | |
58 | EXPORT_SYMBOL(journal_release_buffer); | |
59 | EXPORT_SYMBOL(journal_forget); | |
60 | #if 0 | |
61 | EXPORT_SYMBOL(journal_sync_buffer); | |
62 | #endif | |
63 | EXPORT_SYMBOL(journal_flush); | |
64 | EXPORT_SYMBOL(journal_revoke); | |
65 | ||
66 | EXPORT_SYMBOL(journal_init_dev); | |
67 | EXPORT_SYMBOL(journal_init_inode); | |
68 | EXPORT_SYMBOL(journal_update_format); | |
69 | EXPORT_SYMBOL(journal_check_used_features); | |
70 | EXPORT_SYMBOL(journal_check_available_features); | |
71 | EXPORT_SYMBOL(journal_set_features); | |
72 | EXPORT_SYMBOL(journal_create); | |
73 | EXPORT_SYMBOL(journal_load); | |
74 | EXPORT_SYMBOL(journal_destroy); | |
1da177e4 LT |
75 | EXPORT_SYMBOL(journal_abort); |
76 | EXPORT_SYMBOL(journal_errno); | |
77 | EXPORT_SYMBOL(journal_ack_err); | |
78 | EXPORT_SYMBOL(journal_clear_err); | |
79 | EXPORT_SYMBOL(log_wait_commit); | |
ff5e4b51 | 80 | EXPORT_SYMBOL(log_start_commit); |
1da177e4 LT |
81 | EXPORT_SYMBOL(journal_start_commit); |
82 | EXPORT_SYMBOL(journal_force_commit_nested); | |
83 | EXPORT_SYMBOL(journal_wipe); | |
84 | EXPORT_SYMBOL(journal_blocks_per_page); | |
85 | EXPORT_SYMBOL(journal_invalidatepage); | |
86 | EXPORT_SYMBOL(journal_try_to_free_buffers); | |
87 | EXPORT_SYMBOL(journal_force_commit); | |
88 | ||
89 | static int journal_convert_superblock_v1(journal_t *, journal_superblock_t *); | |
022a4a7b | 90 | static void __journal_abort_soft (journal_t *journal, int errno); |
dff6825e | 91 | static const char *journal_dev_name(journal_t *journal, char *buffer); |
1da177e4 LT |
92 | |
93 | /* | |
94 | * Helper function used to manage commit timeouts | |
95 | */ | |
96 | ||
97 | static void commit_timeout(unsigned long __data) | |
98 | { | |
99 | struct task_struct * p = (struct task_struct *) __data; | |
100 | ||
101 | wake_up_process(p); | |
102 | } | |
103 | ||
1da177e4 LT |
104 | /* |
105 | * kjournald: The main thread function used to manage a logging device | |
106 | * journal. | |
107 | * | |
108 | * This kernel thread is responsible for two things: | |
109 | * | |
110 | * 1) COMMIT: Every so often we need to commit the current state of the | |
111 | * filesystem to disk. The journal thread is responsible for writing | |
112 | * all of the metadata buffers to disk. | |
113 | * | |
114 | * 2) CHECKPOINT: We cannot reuse a used section of the log file until all | |
115 | * of the data in that part of the log has been rewritten elsewhere on | |
116 | * the disk. Flushing these old buffers to reclaim space in the log is | |
117 | * known as checkpointing, and this thread is responsible for that job. | |
118 | */ | |
119 | ||
022a4a7b | 120 | static int kjournald(void *arg) |
1da177e4 | 121 | { |
e3df1898 | 122 | journal_t *journal = arg; |
1da177e4 | 123 | transaction_t *transaction; |
1da177e4 | 124 | |
e3df1898 AM |
125 | /* |
126 | * Set up an interval timer which can be used to trigger a commit wakeup | |
127 | * after the commit interval expires | |
128 | */ | |
129 | setup_timer(&journal->j_commit_timer, commit_timeout, | |
130 | (unsigned long)current); | |
1da177e4 | 131 | |
35c80422 NC |
132 | set_freezable(); |
133 | ||
1da177e4 LT |
134 | /* Record that the journal thread is running */ |
135 | journal->j_task = current; | |
136 | wake_up(&journal->j_wait_done_commit); | |
137 | ||
138 | printk(KERN_INFO "kjournald starting. Commit interval %ld seconds\n", | |
139 | journal->j_commit_interval / HZ); | |
140 | ||
141 | /* | |
142 | * And now, wait forever for commit wakeup events. | |
143 | */ | |
144 | spin_lock(&journal->j_state_lock); | |
145 | ||
146 | loop: | |
147 | if (journal->j_flags & JFS_UNMOUNT) | |
148 | goto end_loop; | |
149 | ||
150 | jbd_debug(1, "commit_sequence=%d, commit_request=%d\n", | |
151 | journal->j_commit_sequence, journal->j_commit_request); | |
152 | ||
153 | if (journal->j_commit_sequence != journal->j_commit_request) { | |
154 | jbd_debug(1, "OK, requests differ\n"); | |
155 | spin_unlock(&journal->j_state_lock); | |
e3df1898 | 156 | del_timer_sync(&journal->j_commit_timer); |
1da177e4 LT |
157 | journal_commit_transaction(journal); |
158 | spin_lock(&journal->j_state_lock); | |
159 | goto loop; | |
160 | } | |
161 | ||
162 | wake_up(&journal->j_wait_done_commit); | |
3e1d1d28 | 163 | if (freezing(current)) { |
1da177e4 LT |
164 | /* |
165 | * The simpler the better. Flushing journal isn't a | |
166 | * good idea, because that depends on threads that may | |
167 | * be already stopped. | |
168 | */ | |
169 | jbd_debug(1, "Now suspending kjournald\n"); | |
170 | spin_unlock(&journal->j_state_lock); | |
a0acae0e | 171 | try_to_freeze(); |
1da177e4 LT |
172 | spin_lock(&journal->j_state_lock); |
173 | } else { | |
174 | /* | |
175 | * We assume on resume that commits are already there, | |
176 | * so we don't sleep | |
177 | */ | |
178 | DEFINE_WAIT(wait); | |
179 | int should_sleep = 1; | |
180 | ||
181 | prepare_to_wait(&journal->j_wait_commit, &wait, | |
182 | TASK_INTERRUPTIBLE); | |
183 | if (journal->j_commit_sequence != journal->j_commit_request) | |
184 | should_sleep = 0; | |
185 | transaction = journal->j_running_transaction; | |
186 | if (transaction && time_after_eq(jiffies, | |
187 | transaction->t_expires)) | |
188 | should_sleep = 0; | |
cbf0d27a | 189 | if (journal->j_flags & JFS_UNMOUNT) |
e9ad5620 | 190 | should_sleep = 0; |
1da177e4 LT |
191 | if (should_sleep) { |
192 | spin_unlock(&journal->j_state_lock); | |
193 | schedule(); | |
194 | spin_lock(&journal->j_state_lock); | |
195 | } | |
196 | finish_wait(&journal->j_wait_commit, &wait); | |
197 | } | |
198 | ||
199 | jbd_debug(1, "kjournald wakes\n"); | |
200 | ||
201 | /* | |
202 | * Were we woken up by a commit wakeup event? | |
203 | */ | |
204 | transaction = journal->j_running_transaction; | |
205 | if (transaction && time_after_eq(jiffies, transaction->t_expires)) { | |
206 | journal->j_commit_request = transaction->t_tid; | |
207 | jbd_debug(1, "woke because of timeout\n"); | |
208 | } | |
209 | goto loop; | |
210 | ||
211 | end_loop: | |
212 | spin_unlock(&journal->j_state_lock); | |
e3df1898 | 213 | del_timer_sync(&journal->j_commit_timer); |
1da177e4 LT |
214 | journal->j_task = NULL; |
215 | wake_up(&journal->j_wait_done_commit); | |
216 | jbd_debug(1, "Journal thread exiting.\n"); | |
217 | return 0; | |
218 | } | |
219 | ||
97f06784 | 220 | static int journal_start_thread(journal_t *journal) |
1da177e4 | 221 | { |
97f06784 PE |
222 | struct task_struct *t; |
223 | ||
224 | t = kthread_run(kjournald, journal, "kjournald"); | |
225 | if (IS_ERR(t)) | |
226 | return PTR_ERR(t); | |
227 | ||
c80544dc | 228 | wait_event(journal->j_wait_done_commit, journal->j_task != NULL); |
97f06784 | 229 | return 0; |
1da177e4 LT |
230 | } |
231 | ||
232 | static void journal_kill_thread(journal_t *journal) | |
233 | { | |
234 | spin_lock(&journal->j_state_lock); | |
235 | journal->j_flags |= JFS_UNMOUNT; | |
236 | ||
237 | while (journal->j_task) { | |
238 | wake_up(&journal->j_wait_commit); | |
239 | spin_unlock(&journal->j_state_lock); | |
c80544dc SH |
240 | wait_event(journal->j_wait_done_commit, |
241 | journal->j_task == NULL); | |
1da177e4 LT |
242 | spin_lock(&journal->j_state_lock); |
243 | } | |
244 | spin_unlock(&journal->j_state_lock); | |
245 | } | |
246 | ||
247 | /* | |
248 | * journal_write_metadata_buffer: write a metadata buffer to the journal. | |
249 | * | |
250 | * Writes a metadata buffer to a given disk block. The actual IO is not | |
251 | * performed but a new buffer_head is constructed which labels the data | |
252 | * to be written with the correct destination disk block. | |
253 | * | |
254 | * Any magic-number escaping which needs to be done will cause a | |
255 | * copy-out here. If the buffer happens to start with the | |
256 | * JFS_MAGIC_NUMBER, then we can't write it to the log directly: the | |
257 | * magic number is only written to the log for descripter blocks. In | |
258 | * this case, we copy the data and replace the first word with 0, and we | |
259 | * return a result code which indicates that this buffer needs to be | |
260 | * marked as an escaped buffer in the corresponding log descriptor | |
261 | * block. The missing word can then be restored when the block is read | |
262 | * during recovery. | |
263 | * | |
264 | * If the source buffer has already been modified by a new transaction | |
265 | * since we took the last commit snapshot, we use the frozen copy of | |
266 | * that data for IO. If we end up using the existing buffer_head's data | |
267 | * for the write, then we *have* to lock the buffer to prevent anyone | |
268 | * else from using and possibly modifying it while the IO is in | |
269 | * progress. | |
270 | * | |
271 | * The function returns a pointer to the buffer_heads to be used for IO. | |
272 | * | |
273 | * We assume that the journal has already been locked in this function. | |
274 | * | |
275 | * Return value: | |
276 | * <0: Error | |
277 | * >=0: Finished OK | |
278 | * | |
279 | * On success: | |
280 | * Bit 0 set == escape performed on the data | |
281 | * Bit 1 set == buffer copy-out performed (kfree the data after IO) | |
282 | */ | |
283 | ||
284 | int journal_write_metadata_buffer(transaction_t *transaction, | |
285 | struct journal_head *jh_in, | |
286 | struct journal_head **jh_out, | |
9c28cbcc | 287 | unsigned int blocknr) |
1da177e4 LT |
288 | { |
289 | int need_copy_out = 0; | |
290 | int done_copy_out = 0; | |
291 | int do_escape = 0; | |
292 | char *mapped_data; | |
293 | struct buffer_head *new_bh; | |
294 | struct journal_head *new_jh; | |
295 | struct page *new_page; | |
296 | unsigned int new_offset; | |
297 | struct buffer_head *bh_in = jh2bh(jh_in); | |
f1015c44 | 298 | journal_t *journal = transaction->t_journal; |
1da177e4 LT |
299 | |
300 | /* | |
301 | * The buffer really shouldn't be locked: only the current committing | |
302 | * transaction is allowed to write it, so nobody else is allowed | |
303 | * to do any IO. | |
304 | * | |
305 | * akpm: except if we're journalling data, and write() output is | |
306 | * also part of a shared mapping, and another thread has | |
307 | * decided to launch a writepage() against this buffer. | |
308 | */ | |
309 | J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in)); | |
310 | ||
311 | new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL); | |
f1015c44 | 312 | /* keep subsequent assertions sane */ |
313 | new_bh->b_state = 0; | |
314 | init_buffer(new_bh, NULL, NULL); | |
315 | atomic_set(&new_bh->b_count, 1); | |
316 | new_jh = journal_add_journal_head(new_bh); /* This sleeps */ | |
1da177e4 LT |
317 | |
318 | /* | |
319 | * If a new transaction has already done a buffer copy-out, then | |
320 | * we use that version of the data for the commit. | |
321 | */ | |
322 | jbd_lock_bh_state(bh_in); | |
323 | repeat: | |
324 | if (jh_in->b_frozen_data) { | |
325 | done_copy_out = 1; | |
326 | new_page = virt_to_page(jh_in->b_frozen_data); | |
327 | new_offset = offset_in_page(jh_in->b_frozen_data); | |
328 | } else { | |
329 | new_page = jh2bh(jh_in)->b_page; | |
330 | new_offset = offset_in_page(jh2bh(jh_in)->b_data); | |
331 | } | |
332 | ||
8fb53c46 | 333 | mapped_data = kmap_atomic(new_page); |
1da177e4 LT |
334 | /* |
335 | * Check for escaping | |
336 | */ | |
337 | if (*((__be32 *)(mapped_data + new_offset)) == | |
338 | cpu_to_be32(JFS_MAGIC_NUMBER)) { | |
339 | need_copy_out = 1; | |
340 | do_escape = 1; | |
341 | } | |
8fb53c46 | 342 | kunmap_atomic(mapped_data); |
1da177e4 LT |
343 | |
344 | /* | |
345 | * Do we need to do a data copy? | |
346 | */ | |
347 | if (need_copy_out && !done_copy_out) { | |
348 | char *tmp; | |
349 | ||
350 | jbd_unlock_bh_state(bh_in); | |
c089d490 | 351 | tmp = jbd_alloc(bh_in->b_size, GFP_NOFS); |
1da177e4 LT |
352 | jbd_lock_bh_state(bh_in); |
353 | if (jh_in->b_frozen_data) { | |
c089d490 | 354 | jbd_free(tmp, bh_in->b_size); |
1da177e4 LT |
355 | goto repeat; |
356 | } | |
357 | ||
358 | jh_in->b_frozen_data = tmp; | |
8fb53c46 | 359 | mapped_data = kmap_atomic(new_page); |
1da177e4 | 360 | memcpy(tmp, mapped_data + new_offset, jh2bh(jh_in)->b_size); |
8fb53c46 | 361 | kunmap_atomic(mapped_data); |
1da177e4 LT |
362 | |
363 | new_page = virt_to_page(tmp); | |
364 | new_offset = offset_in_page(tmp); | |
365 | done_copy_out = 1; | |
366 | } | |
367 | ||
368 | /* | |
369 | * Did we need to do an escaping? Now we've done all the | |
370 | * copying, we can finally do so. | |
371 | */ | |
372 | if (do_escape) { | |
8fb53c46 | 373 | mapped_data = kmap_atomic(new_page); |
1da177e4 | 374 | *((unsigned int *)(mapped_data + new_offset)) = 0; |
8fb53c46 | 375 | kunmap_atomic(mapped_data); |
1da177e4 LT |
376 | } |
377 | ||
1da177e4 LT |
378 | set_bh_page(new_bh, new_page, new_offset); |
379 | new_jh->b_transaction = NULL; | |
380 | new_bh->b_size = jh2bh(jh_in)->b_size; | |
381 | new_bh->b_bdev = transaction->t_journal->j_dev; | |
382 | new_bh->b_blocknr = blocknr; | |
383 | set_buffer_mapped(new_bh); | |
384 | set_buffer_dirty(new_bh); | |
385 | ||
386 | *jh_out = new_jh; | |
387 | ||
388 | /* | |
389 | * The to-be-written buffer needs to get moved to the io queue, | |
390 | * and the original buffer whose contents we are shadowing or | |
391 | * copying is moved to the transaction's shadow queue. | |
392 | */ | |
393 | JBUFFER_TRACE(jh_in, "file as BJ_Shadow"); | |
f1015c44 | 394 | spin_lock(&journal->j_list_lock); |
395 | __journal_file_buffer(jh_in, transaction, BJ_Shadow); | |
396 | spin_unlock(&journal->j_list_lock); | |
397 | jbd_unlock_bh_state(bh_in); | |
398 | ||
1da177e4 LT |
399 | JBUFFER_TRACE(new_jh, "file as BJ_IO"); |
400 | journal_file_buffer(new_jh, transaction, BJ_IO); | |
401 | ||
402 | return do_escape | (done_copy_out << 1); | |
403 | } | |
404 | ||
405 | /* | |
406 | * Allocation code for the journal file. Manage the space left in the | |
407 | * journal, so that we can begin checkpointing when appropriate. | |
408 | */ | |
409 | ||
410 | /* | |
411 | * __log_space_left: Return the number of free blocks left in the journal. | |
412 | * | |
413 | * Called with the journal already locked. | |
414 | * | |
415 | * Called under j_state_lock | |
416 | */ | |
417 | ||
418 | int __log_space_left(journal_t *journal) | |
419 | { | |
420 | int left = journal->j_free; | |
421 | ||
422 | assert_spin_locked(&journal->j_state_lock); | |
423 | ||
424 | /* | |
425 | * Be pessimistic here about the number of those free blocks which | |
426 | * might be required for log descriptor control blocks. | |
427 | */ | |
428 | ||
429 | #define MIN_LOG_RESERVED_BLOCKS 32 /* Allow for rounding errors */ | |
430 | ||
431 | left -= MIN_LOG_RESERVED_BLOCKS; | |
432 | ||
433 | if (left <= 0) | |
434 | return 0; | |
435 | left -= (left >> 3); | |
436 | return left; | |
437 | } | |
438 | ||
439 | /* | |
8fe4cd0d | 440 | * Called under j_state_lock. Returns true if a transaction commit was started. |
1da177e4 LT |
441 | */ |
442 | int __log_start_commit(journal_t *journal, tid_t target) | |
443 | { | |
444 | /* | |
d9b01934 TT |
445 | * The only transaction we can possibly wait upon is the |
446 | * currently running transaction (if it exists). Otherwise, | |
447 | * the target tid must be an old one. | |
1da177e4 | 448 | */ |
7e2fb2d7 ES |
449 | if (journal->j_commit_request != target && |
450 | journal->j_running_transaction && | |
d9b01934 | 451 | journal->j_running_transaction->t_tid == target) { |
1da177e4 | 452 | /* |
bcf3d0bc | 453 | * We want a new commit: OK, mark the request and wakeup the |
1da177e4 LT |
454 | * commit thread. We do _not_ do the commit ourselves. |
455 | */ | |
456 | ||
457 | journal->j_commit_request = target; | |
458 | jbd_debug(1, "JBD: requesting commit %d/%d\n", | |
459 | journal->j_commit_request, | |
460 | journal->j_commit_sequence); | |
461 | wake_up(&journal->j_wait_commit); | |
462 | return 1; | |
d9b01934 TT |
463 | } else if (!tid_geq(journal->j_commit_request, target)) |
464 | /* This should never happen, but if it does, preserve | |
465 | the evidence before kjournald goes into a loop and | |
466 | increments j_commit_sequence beyond all recognition. */ | |
467 | WARN_ONCE(1, "jbd: bad log_start_commit: %u %u %u %u\n", | |
468 | journal->j_commit_request, journal->j_commit_sequence, | |
469 | target, journal->j_running_transaction ? | |
470 | journal->j_running_transaction->t_tid : 0); | |
1da177e4 LT |
471 | return 0; |
472 | } | |
473 | ||
474 | int log_start_commit(journal_t *journal, tid_t tid) | |
475 | { | |
476 | int ret; | |
477 | ||
478 | spin_lock(&journal->j_state_lock); | |
479 | ret = __log_start_commit(journal, tid); | |
480 | spin_unlock(&journal->j_state_lock); | |
481 | return ret; | |
482 | } | |
483 | ||
484 | /* | |
485 | * Force and wait upon a commit if the calling process is not within | |
486 | * transaction. This is used for forcing out undo-protected data which contains | |
487 | * bitmaps, when the fs is running out of space. | |
488 | * | |
489 | * We can only force the running transaction if we don't have an active handle; | |
490 | * otherwise, we will deadlock. | |
491 | * | |
492 | * Returns true if a transaction was started. | |
493 | */ | |
494 | int journal_force_commit_nested(journal_t *journal) | |
495 | { | |
496 | transaction_t *transaction = NULL; | |
497 | tid_t tid; | |
498 | ||
499 | spin_lock(&journal->j_state_lock); | |
500 | if (journal->j_running_transaction && !current->journal_info) { | |
501 | transaction = journal->j_running_transaction; | |
502 | __log_start_commit(journal, transaction->t_tid); | |
503 | } else if (journal->j_committing_transaction) | |
504 | transaction = journal->j_committing_transaction; | |
505 | ||
506 | if (!transaction) { | |
507 | spin_unlock(&journal->j_state_lock); | |
508 | return 0; /* Nothing to retry */ | |
509 | } | |
510 | ||
511 | tid = transaction->t_tid; | |
512 | spin_unlock(&journal->j_state_lock); | |
513 | log_wait_commit(journal, tid); | |
514 | return 1; | |
515 | } | |
516 | ||
517 | /* | |
518 | * Start a commit of the current running transaction (if any). Returns true | |
8fe4cd0d JK |
519 | * if a transaction is going to be committed (or is currently already |
520 | * committing), and fills its tid in at *ptid | |
1da177e4 LT |
521 | */ |
522 | int journal_start_commit(journal_t *journal, tid_t *ptid) | |
523 | { | |
524 | int ret = 0; | |
525 | ||
526 | spin_lock(&journal->j_state_lock); | |
527 | if (journal->j_running_transaction) { | |
528 | tid_t tid = journal->j_running_transaction->t_tid; | |
529 | ||
8fe4cd0d JK |
530 | __log_start_commit(journal, tid); |
531 | /* There's a running transaction and we've just made sure | |
532 | * it's commit has been scheduled. */ | |
533 | if (ptid) | |
1da177e4 | 534 | *ptid = tid; |
8fe4cd0d JK |
535 | ret = 1; |
536 | } else if (journal->j_committing_transaction) { | |
1da177e4 | 537 | /* |
12810ad7 AB |
538 | * If commit has been started, then we have to wait for |
539 | * completion of that transaction. | |
1da177e4 | 540 | */ |
8fe4cd0d JK |
541 | if (ptid) |
542 | *ptid = journal->j_committing_transaction->t_tid; | |
1da177e4 LT |
543 | ret = 1; |
544 | } | |
545 | spin_unlock(&journal->j_state_lock); | |
546 | return ret; | |
547 | } | |
548 | ||
549 | /* | |
550 | * Wait for a specified commit to complete. | |
551 | * The caller may not hold the journal lock. | |
552 | */ | |
553 | int log_wait_commit(journal_t *journal, tid_t tid) | |
554 | { | |
555 | int err = 0; | |
556 | ||
557 | #ifdef CONFIG_JBD_DEBUG | |
558 | spin_lock(&journal->j_state_lock); | |
559 | if (!tid_geq(journal->j_commit_request, tid)) { | |
560 | printk(KERN_EMERG | |
561 | "%s: error: j_commit_request=%d, tid=%d\n", | |
08fc99bf | 562 | __func__, journal->j_commit_request, tid); |
1da177e4 LT |
563 | } |
564 | spin_unlock(&journal->j_state_lock); | |
565 | #endif | |
566 | spin_lock(&journal->j_state_lock); | |
2db938be JK |
567 | if (!tid_geq(journal->j_commit_waited, tid)) |
568 | journal->j_commit_waited = tid; | |
1da177e4 LT |
569 | while (tid_gt(tid, journal->j_commit_sequence)) { |
570 | jbd_debug(1, "JBD: want %d, j_commit_sequence=%d\n", | |
571 | tid, journal->j_commit_sequence); | |
572 | wake_up(&journal->j_wait_commit); | |
573 | spin_unlock(&journal->j_state_lock); | |
574 | wait_event(journal->j_wait_done_commit, | |
575 | !tid_gt(tid, journal->j_commit_sequence)); | |
576 | spin_lock(&journal->j_state_lock); | |
577 | } | |
578 | spin_unlock(&journal->j_state_lock); | |
579 | ||
580 | if (unlikely(is_journal_aborted(journal))) { | |
581 | printk(KERN_EMERG "journal commit I/O error\n"); | |
582 | err = -EIO; | |
583 | } | |
584 | return err; | |
585 | } | |
586 | ||
03f4d804 JK |
587 | /* |
588 | * Return 1 if a given transaction has not yet sent barrier request | |
589 | * connected with a transaction commit. If 0 is returned, transaction | |
590 | * may or may not have sent the barrier. Used to avoid sending barrier | |
591 | * twice in common cases. | |
592 | */ | |
593 | int journal_trans_will_send_data_barrier(journal_t *journal, tid_t tid) | |
594 | { | |
595 | int ret = 0; | |
596 | transaction_t *commit_trans; | |
597 | ||
598 | if (!(journal->j_flags & JFS_BARRIER)) | |
599 | return 0; | |
600 | spin_lock(&journal->j_state_lock); | |
601 | /* Transaction already committed? */ | |
602 | if (tid_geq(journal->j_commit_sequence, tid)) | |
603 | goto out; | |
604 | /* | |
605 | * Transaction is being committed and we already proceeded to | |
606 | * writing commit record? | |
607 | */ | |
608 | commit_trans = journal->j_committing_transaction; | |
609 | if (commit_trans && commit_trans->t_tid == tid && | |
610 | commit_trans->t_state >= T_COMMIT_RECORD) | |
611 | goto out; | |
612 | ret = 1; | |
613 | out: | |
614 | spin_unlock(&journal->j_state_lock); | |
615 | return ret; | |
616 | } | |
52779708 | 617 | EXPORT_SYMBOL(journal_trans_will_send_data_barrier); |
03f4d804 | 618 | |
1da177e4 LT |
619 | /* |
620 | * Log buffer allocation routines: | |
621 | */ | |
622 | ||
9c28cbcc | 623 | int journal_next_log_block(journal_t *journal, unsigned int *retp) |
1da177e4 | 624 | { |
9c28cbcc | 625 | unsigned int blocknr; |
1da177e4 LT |
626 | |
627 | spin_lock(&journal->j_state_lock); | |
628 | J_ASSERT(journal->j_free > 1); | |
629 | ||
630 | blocknr = journal->j_head; | |
631 | journal->j_head++; | |
632 | journal->j_free--; | |
633 | if (journal->j_head == journal->j_last) | |
634 | journal->j_head = journal->j_first; | |
635 | spin_unlock(&journal->j_state_lock); | |
636 | return journal_bmap(journal, blocknr, retp); | |
637 | } | |
638 | ||
639 | /* | |
640 | * Conversion of logical to physical block numbers for the journal | |
641 | * | |
642 | * On external journals the journal blocks are identity-mapped, so | |
643 | * this is a no-op. If needed, we can use j_blk_offset - everything is | |
644 | * ready. | |
645 | */ | |
9c28cbcc JK |
646 | int journal_bmap(journal_t *journal, unsigned int blocknr, |
647 | unsigned int *retp) | |
1da177e4 LT |
648 | { |
649 | int err = 0; | |
9c28cbcc | 650 | unsigned int ret; |
1da177e4 LT |
651 | |
652 | if (journal->j_inode) { | |
653 | ret = bmap(journal->j_inode, blocknr); | |
654 | if (ret) | |
655 | *retp = ret; | |
656 | else { | |
657 | char b[BDEVNAME_SIZE]; | |
658 | ||
659 | printk(KERN_ALERT "%s: journal block not found " | |
9c28cbcc | 660 | "at offset %u on %s\n", |
08fc99bf | 661 | __func__, |
1da177e4 LT |
662 | blocknr, |
663 | bdevname(journal->j_dev, b)); | |
664 | err = -EIO; | |
665 | __journal_abort_soft(journal, err); | |
666 | } | |
667 | } else { | |
668 | *retp = blocknr; /* +journal->j_blk_offset */ | |
669 | } | |
670 | return err; | |
671 | } | |
672 | ||
673 | /* | |
674 | * We play buffer_head aliasing tricks to write data/metadata blocks to | |
675 | * the journal without copying their contents, but for journal | |
676 | * descriptor blocks we do need to generate bona fide buffers. | |
677 | * | |
678 | * After the caller of journal_get_descriptor_buffer() has finished modifying | |
679 | * the buffer's contents they really should run flush_dcache_page(bh->b_page). | |
680 | * But we don't bother doing that, so there will be coherency problems with | |
681 | * mmaps of blockdevs which hold live JBD-controlled filesystems. | |
682 | */ | |
683 | struct journal_head *journal_get_descriptor_buffer(journal_t *journal) | |
684 | { | |
685 | struct buffer_head *bh; | |
9c28cbcc | 686 | unsigned int blocknr; |
1da177e4 LT |
687 | int err; |
688 | ||
689 | err = journal_next_log_block(journal, &blocknr); | |
690 | ||
691 | if (err) | |
692 | return NULL; | |
693 | ||
694 | bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); | |
ecca9af0 JK |
695 | if (!bh) |
696 | return NULL; | |
1da177e4 LT |
697 | lock_buffer(bh); |
698 | memset(bh->b_data, 0, journal->j_blocksize); | |
699 | set_buffer_uptodate(bh); | |
700 | unlock_buffer(bh); | |
701 | BUFFER_TRACE(bh, "return this buffer"); | |
702 | return journal_add_journal_head(bh); | |
703 | } | |
704 | ||
705 | /* | |
706 | * Management for journal control blocks: functions to create and | |
707 | * destroy journal_t structures, and to initialise and read existing | |
708 | * journal blocks from disk. */ | |
709 | ||
710 | /* First: create and setup a journal_t object in memory. We initialise | |
711 | * very few fields yet: that has to wait until we have created the | |
712 | * journal structures from from scratch, or loaded them from disk. */ | |
713 | ||
714 | static journal_t * journal_init_common (void) | |
715 | { | |
716 | journal_t *journal; | |
717 | int err; | |
718 | ||
8c3478a5 | 719 | journal = kzalloc(sizeof(*journal), GFP_KERNEL); |
1da177e4 LT |
720 | if (!journal) |
721 | goto fail; | |
1da177e4 LT |
722 | |
723 | init_waitqueue_head(&journal->j_wait_transaction_locked); | |
724 | init_waitqueue_head(&journal->j_wait_logspace); | |
725 | init_waitqueue_head(&journal->j_wait_done_commit); | |
726 | init_waitqueue_head(&journal->j_wait_checkpoint); | |
727 | init_waitqueue_head(&journal->j_wait_commit); | |
728 | init_waitqueue_head(&journal->j_wait_updates); | |
2c68ee75 | 729 | mutex_init(&journal->j_checkpoint_mutex); |
1da177e4 LT |
730 | spin_lock_init(&journal->j_revoke_lock); |
731 | spin_lock_init(&journal->j_list_lock); | |
732 | spin_lock_init(&journal->j_state_lock); | |
733 | ||
734 | journal->j_commit_interval = (HZ * JBD_DEFAULT_MAX_COMMIT_AGE); | |
735 | ||
736 | /* The journal is marked for error until we succeed with recovery! */ | |
737 | journal->j_flags = JFS_ABORT; | |
738 | ||
739 | /* Set up a default-sized revoke table for the new mount. */ | |
740 | err = journal_init_revoke(journal, JOURNAL_REVOKE_DEFAULT_HASH); | |
741 | if (err) { | |
742 | kfree(journal); | |
743 | goto fail; | |
744 | } | |
745 | return journal; | |
746 | fail: | |
747 | return NULL; | |
748 | } | |
749 | ||
750 | /* journal_init_dev and journal_init_inode: | |
751 | * | |
752 | * Create a journal structure assigned some fixed set of disk blocks to | |
753 | * the journal. We don't actually touch those disk blocks yet, but we | |
754 | * need to set up all of the mapping information to tell the journaling | |
755 | * system where the journal blocks are. | |
756 | * | |
757 | */ | |
758 | ||
759 | /** | |
0cf01f66 | 760 | * journal_t * journal_init_dev() - creates and initialises a journal structure |
1da177e4 LT |
761 | * @bdev: Block device on which to create the journal |
762 | * @fs_dev: Device which hold journalled filesystem for this journal. | |
763 | * @start: Block nr Start of journal. | |
37ed3222 | 764 | * @len: Length of the journal in blocks. |
1da177e4 | 765 | * @blocksize: blocksize of journalling device |
0cf01f66 RD |
766 | * |
767 | * Returns: a newly created journal_t * | |
ae6ddcc5 | 768 | * |
1da177e4 LT |
769 | * journal_init_dev creates a journal which maps a fixed contiguous |
770 | * range of blocks on an arbitrary block device. | |
ae6ddcc5 | 771 | * |
1da177e4 LT |
772 | */ |
773 | journal_t * journal_init_dev(struct block_device *bdev, | |
774 | struct block_device *fs_dev, | |
775 | int start, int len, int blocksize) | |
776 | { | |
777 | journal_t *journal = journal_init_common(); | |
778 | struct buffer_head *bh; | |
779 | int n; | |
780 | ||
781 | if (!journal) | |
782 | return NULL; | |
783 | ||
1da177e4 | 784 | /* journal descriptor can store up to n blocks -bzzz */ |
d1807793 | 785 | journal->j_blocksize = blocksize; |
1da177e4 LT |
786 | n = journal->j_blocksize / sizeof(journal_block_tag_t); |
787 | journal->j_wbufsize = n; | |
788 | journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL); | |
789 | if (!journal->j_wbuf) { | |
25985edc | 790 | printk(KERN_ERR "%s: Can't allocate bhs for commit thread\n", |
08fc99bf | 791 | __func__); |
ecca9af0 | 792 | goto out_err; |
1da177e4 | 793 | } |
d1807793 ZM |
794 | journal->j_dev = bdev; |
795 | journal->j_fs_dev = fs_dev; | |
796 | journal->j_blk_offset = start; | |
797 | journal->j_maxlen = len; | |
798 | ||
799 | bh = __getblk(journal->j_dev, start, journal->j_blocksize); | |
ecca9af0 JK |
800 | if (!bh) { |
801 | printk(KERN_ERR | |
802 | "%s: Cannot get buffer for journal superblock\n", | |
803 | __func__); | |
804 | goto out_err; | |
805 | } | |
d1807793 ZM |
806 | journal->j_sb_buffer = bh; |
807 | journal->j_superblock = (journal_superblock_t *)bh->b_data; | |
ecca9af0 | 808 | |
1da177e4 | 809 | return journal; |
ecca9af0 | 810 | out_err: |
7b02bec0 | 811 | kfree(journal->j_wbuf); |
ecca9af0 JK |
812 | kfree(journal); |
813 | return NULL; | |
1da177e4 | 814 | } |
ae6ddcc5 MC |
815 | |
816 | /** | |
1da177e4 LT |
817 | * journal_t * journal_init_inode () - creates a journal which maps to a inode. |
818 | * @inode: An inode to create the journal in | |
ae6ddcc5 | 819 | * |
1da177e4 LT |
820 | * journal_init_inode creates a journal which maps an on-disk inode as |
821 | * the journal. The inode must exist already, must support bmap() and | |
822 | * must have all data blocks preallocated. | |
823 | */ | |
824 | journal_t * journal_init_inode (struct inode *inode) | |
825 | { | |
826 | struct buffer_head *bh; | |
827 | journal_t *journal = journal_init_common(); | |
828 | int err; | |
829 | int n; | |
9c28cbcc | 830 | unsigned int blocknr; |
1da177e4 LT |
831 | |
832 | if (!journal) | |
833 | return NULL; | |
834 | ||
835 | journal->j_dev = journal->j_fs_dev = inode->i_sb->s_bdev; | |
836 | journal->j_inode = inode; | |
837 | jbd_debug(1, | |
838 | "journal %p: inode %s/%ld, size %Ld, bits %d, blksize %ld\n", | |
ae6ddcc5 | 839 | journal, inode->i_sb->s_id, inode->i_ino, |
1da177e4 LT |
840 | (long long) inode->i_size, |
841 | inode->i_sb->s_blocksize_bits, inode->i_sb->s_blocksize); | |
842 | ||
843 | journal->j_maxlen = inode->i_size >> inode->i_sb->s_blocksize_bits; | |
844 | journal->j_blocksize = inode->i_sb->s_blocksize; | |
845 | ||
846 | /* journal descriptor can store up to n blocks -bzzz */ | |
847 | n = journal->j_blocksize / sizeof(journal_block_tag_t); | |
848 | journal->j_wbufsize = n; | |
849 | journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL); | |
850 | if (!journal->j_wbuf) { | |
25985edc | 851 | printk(KERN_ERR "%s: Can't allocate bhs for commit thread\n", |
08fc99bf | 852 | __func__); |
ecca9af0 | 853 | goto out_err; |
1da177e4 LT |
854 | } |
855 | ||
856 | err = journal_bmap(journal, 0, &blocknr); | |
857 | /* If that failed, give up */ | |
858 | if (err) { | |
3c26bdb4 | 859 | printk(KERN_ERR "%s: Cannot locate journal superblock\n", |
08fc99bf | 860 | __func__); |
ecca9af0 | 861 | goto out_err; |
1da177e4 LT |
862 | } |
863 | ||
864 | bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); | |
ecca9af0 JK |
865 | if (!bh) { |
866 | printk(KERN_ERR | |
867 | "%s: Cannot get buffer for journal superblock\n", | |
868 | __func__); | |
869 | goto out_err; | |
870 | } | |
1da177e4 LT |
871 | journal->j_sb_buffer = bh; |
872 | journal->j_superblock = (journal_superblock_t *)bh->b_data; | |
873 | ||
874 | return journal; | |
ecca9af0 | 875 | out_err: |
7b02bec0 | 876 | kfree(journal->j_wbuf); |
ecca9af0 JK |
877 | kfree(journal); |
878 | return NULL; | |
1da177e4 LT |
879 | } |
880 | ||
ae6ddcc5 | 881 | /* |
1da177e4 LT |
882 | * If the journal init or create aborts, we need to mark the journal |
883 | * superblock as being NULL to prevent the journal destroy from writing | |
ae6ddcc5 | 884 | * back a bogus superblock. |
1da177e4 LT |
885 | */ |
886 | static void journal_fail_superblock (journal_t *journal) | |
887 | { | |
888 | struct buffer_head *bh = journal->j_sb_buffer; | |
889 | brelse(bh); | |
890 | journal->j_sb_buffer = NULL; | |
891 | } | |
892 | ||
893 | /* | |
894 | * Given a journal_t structure, initialise the various fields for | |
895 | * startup of a new journaling session. We use this both when creating | |
896 | * a journal, and after recovering an old journal to reset it for | |
897 | * subsequent use. | |
898 | */ | |
899 | ||
900 | static int journal_reset(journal_t *journal) | |
901 | { | |
902 | journal_superblock_t *sb = journal->j_superblock; | |
9c28cbcc | 903 | unsigned int first, last; |
1da177e4 LT |
904 | |
905 | first = be32_to_cpu(sb->s_first); | |
906 | last = be32_to_cpu(sb->s_maxlen); | |
7447a668 | 907 | if (first + JFS_MIN_JOURNAL_BLOCKS > last + 1) { |
9c28cbcc | 908 | printk(KERN_ERR "JBD: Journal too short (blocks %u-%u).\n", |
7447a668 JK |
909 | first, last); |
910 | journal_fail_superblock(journal); | |
911 | return -EINVAL; | |
912 | } | |
1da177e4 LT |
913 | |
914 | journal->j_first = first; | |
915 | journal->j_last = last; | |
916 | ||
917 | journal->j_head = first; | |
918 | journal->j_tail = first; | |
919 | journal->j_free = last - first; | |
920 | ||
921 | journal->j_tail_sequence = journal->j_transaction_sequence; | |
922 | journal->j_commit_sequence = journal->j_transaction_sequence - 1; | |
923 | journal->j_commit_request = journal->j_commit_sequence; | |
924 | ||
925 | journal->j_max_transaction_buffers = journal->j_maxlen / 4; | |
926 | ||
9754e39c JK |
927 | /* |
928 | * As a special case, if the on-disk copy is already marked as needing | |
929 | * no recovery (s_start == 0), then we can safely defer the superblock | |
930 | * update until the next commit by setting JFS_FLUSHED. This avoids | |
931 | * attempting a write to a potential-readonly device. | |
932 | */ | |
933 | if (sb->s_start == 0) { | |
934 | jbd_debug(1,"JBD: Skipping superblock update on recovered sb " | |
935 | "(start %u, seq %d, errno %d)\n", | |
936 | journal->j_tail, journal->j_tail_sequence, | |
937 | journal->j_errno); | |
938 | journal->j_flags |= JFS_FLUSHED; | |
939 | } else { | |
1ce8486d JK |
940 | /* Lock here to make assertions happy... */ |
941 | mutex_lock(&journal->j_checkpoint_mutex); | |
fd2cbd4d JK |
942 | /* |
943 | * Update log tail information. We use WRITE_FUA since new | |
944 | * transaction will start reusing journal space and so we | |
945 | * must make sure information about current log tail is on | |
946 | * disk before that. | |
947 | */ | |
948 | journal_update_sb_log_tail(journal, | |
949 | journal->j_tail_sequence, | |
950 | journal->j_tail, | |
951 | WRITE_FUA); | |
1ce8486d | 952 | mutex_unlock(&journal->j_checkpoint_mutex); |
9754e39c | 953 | } |
97f06784 | 954 | return journal_start_thread(journal); |
1da177e4 LT |
955 | } |
956 | ||
ae6ddcc5 | 957 | /** |
1da177e4 LT |
958 | * int journal_create() - Initialise the new journal file |
959 | * @journal: Journal to create. This structure must have been initialised | |
ae6ddcc5 | 960 | * |
1da177e4 LT |
961 | * Given a journal_t structure which tells us which disk blocks we can |
962 | * use, create a new journal superblock and initialise all of the | |
ae6ddcc5 | 963 | * journal fields from scratch. |
1da177e4 LT |
964 | **/ |
965 | int journal_create(journal_t *journal) | |
966 | { | |
9c28cbcc | 967 | unsigned int blocknr; |
1da177e4 LT |
968 | struct buffer_head *bh; |
969 | journal_superblock_t *sb; | |
970 | int i, err; | |
971 | ||
972 | if (journal->j_maxlen < JFS_MIN_JOURNAL_BLOCKS) { | |
973 | printk (KERN_ERR "Journal length (%d blocks) too short.\n", | |
974 | journal->j_maxlen); | |
975 | journal_fail_superblock(journal); | |
976 | return -EINVAL; | |
977 | } | |
978 | ||
979 | if (journal->j_inode == NULL) { | |
980 | /* | |
981 | * We don't know what block to start at! | |
982 | */ | |
983 | printk(KERN_EMERG | |
984 | "%s: creation of journal on external device!\n", | |
08fc99bf | 985 | __func__); |
1da177e4 LT |
986 | BUG(); |
987 | } | |
988 | ||
989 | /* Zero out the entire journal on disk. We cannot afford to | |
990 | have any blocks on disk beginning with JFS_MAGIC_NUMBER. */ | |
991 | jbd_debug(1, "JBD: Zeroing out journal blocks...\n"); | |
992 | for (i = 0; i < journal->j_maxlen; i++) { | |
993 | err = journal_bmap(journal, i, &blocknr); | |
994 | if (err) | |
995 | return err; | |
996 | bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); | |
2a0e3388 NK |
997 | if (unlikely(!bh)) |
998 | return -ENOMEM; | |
1da177e4 LT |
999 | lock_buffer(bh); |
1000 | memset (bh->b_data, 0, journal->j_blocksize); | |
1001 | BUFFER_TRACE(bh, "marking dirty"); | |
1002 | mark_buffer_dirty(bh); | |
1003 | BUFFER_TRACE(bh, "marking uptodate"); | |
1004 | set_buffer_uptodate(bh); | |
1005 | unlock_buffer(bh); | |
1006 | __brelse(bh); | |
1007 | } | |
1008 | ||
1009 | sync_blockdev(journal->j_dev); | |
1010 | jbd_debug(1, "JBD: journal cleared.\n"); | |
1011 | ||
1012 | /* OK, fill in the initial static fields in the new superblock */ | |
1013 | sb = journal->j_superblock; | |
1014 | ||
1015 | sb->s_header.h_magic = cpu_to_be32(JFS_MAGIC_NUMBER); | |
1016 | sb->s_header.h_blocktype = cpu_to_be32(JFS_SUPERBLOCK_V2); | |
1017 | ||
1018 | sb->s_blocksize = cpu_to_be32(journal->j_blocksize); | |
1019 | sb->s_maxlen = cpu_to_be32(journal->j_maxlen); | |
1020 | sb->s_first = cpu_to_be32(1); | |
1021 | ||
1022 | journal->j_transaction_sequence = 1; | |
1023 | ||
1024 | journal->j_flags &= ~JFS_ABORT; | |
1025 | journal->j_format_version = 2; | |
1026 | ||
1027 | return journal_reset(journal); | |
1028 | } | |
1029 | ||
fd2cbd4d | 1030 | static void journal_write_superblock(journal_t *journal, int write_op) |
1da177e4 | 1031 | { |
1da177e4 | 1032 | struct buffer_head *bh = journal->j_sb_buffer; |
fd2cbd4d | 1033 | int ret; |
1da177e4 | 1034 | |
fd2cbd4d JK |
1035 | trace_journal_write_superblock(journal, write_op); |
1036 | if (!(journal->j_flags & JFS_BARRIER)) | |
1037 | write_op &= ~(REQ_FUA | REQ_FLUSH); | |
1038 | lock_buffer(bh); | |
dff6825e DW |
1039 | if (buffer_write_io_error(bh)) { |
1040 | char b[BDEVNAME_SIZE]; | |
1041 | /* | |
1042 | * Oh, dear. A previous attempt to write the journal | |
1043 | * superblock failed. This could happen because the | |
1044 | * USB device was yanked out. Or it could happen to | |
1045 | * be a transient write error and maybe the block will | |
1046 | * be remapped. Nothing we can do but to retry the | |
1047 | * write and hope for the best. | |
1048 | */ | |
1049 | printk(KERN_ERR "JBD: previous I/O error detected " | |
1050 | "for journal superblock update for %s.\n", | |
1051 | journal_dev_name(journal, b)); | |
1052 | clear_buffer_write_io_error(bh); | |
1053 | set_buffer_uptodate(bh); | |
1054 | } | |
1055 | ||
fd2cbd4d JK |
1056 | get_bh(bh); |
1057 | bh->b_end_io = end_buffer_write_sync; | |
1058 | ret = submit_bh(write_op, bh); | |
1059 | wait_on_buffer(bh); | |
9754e39c | 1060 | if (buffer_write_io_error(bh)) { |
9754e39c JK |
1061 | clear_buffer_write_io_error(bh); |
1062 | set_buffer_uptodate(bh); | |
fd2cbd4d JK |
1063 | ret = -EIO; |
1064 | } | |
1065 | if (ret) { | |
1066 | char b[BDEVNAME_SIZE]; | |
1067 | printk(KERN_ERR "JBD: Error %d detected " | |
1068 | "when updating journal superblock for %s.\n", | |
1069 | ret, journal_dev_name(journal, b)); | |
9754e39c JK |
1070 | } |
1071 | } | |
1072 | ||
1073 | /** | |
1074 | * journal_update_sb_log_tail() - Update log tail in journal sb on disk. | |
1075 | * @journal: The journal to update. | |
fd2cbd4d JK |
1076 | * @tail_tid: TID of the new transaction at the tail of the log |
1077 | * @tail_block: The first block of the transaction at the tail of the log | |
1078 | * @write_op: With which operation should we write the journal sb | |
9754e39c JK |
1079 | * |
1080 | * Update a journal's superblock information about log tail and write it to | |
1081 | * disk, waiting for the IO to complete. | |
1082 | */ | |
fd2cbd4d JK |
1083 | void journal_update_sb_log_tail(journal_t *journal, tid_t tail_tid, |
1084 | unsigned int tail_block, int write_op) | |
9754e39c JK |
1085 | { |
1086 | journal_superblock_t *sb = journal->j_superblock; | |
1087 | ||
1ce8486d | 1088 | BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex)); |
fd2cbd4d JK |
1089 | jbd_debug(1,"JBD: updating superblock (start %u, seq %u)\n", |
1090 | tail_block, tail_tid); | |
1da177e4 | 1091 | |
fd2cbd4d JK |
1092 | sb->s_sequence = cpu_to_be32(tail_tid); |
1093 | sb->s_start = cpu_to_be32(tail_block); | |
1da177e4 | 1094 | |
fd2cbd4d | 1095 | journal_write_superblock(journal, write_op); |
1da177e4 | 1096 | |
9754e39c JK |
1097 | /* Log is no longer empty */ |
1098 | spin_lock(&journal->j_state_lock); | |
1099 | WARN_ON(!sb->s_sequence); | |
1100 | journal->j_flags &= ~JFS_FLUSHED; | |
1101 | spin_unlock(&journal->j_state_lock); | |
1102 | } | |
1103 | ||
1104 | /** | |
1105 | * mark_journal_empty() - Mark on disk journal as empty. | |
1106 | * @journal: The journal to update. | |
1107 | * | |
1108 | * Update a journal's dynamic superblock fields to show that journal is empty. | |
1109 | * Write updated superblock to disk waiting for IO to complete. | |
1110 | */ | |
1111 | static void mark_journal_empty(journal_t *journal) | |
1112 | { | |
1113 | journal_superblock_t *sb = journal->j_superblock; | |
1da177e4 | 1114 | |
1ce8486d | 1115 | BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex)); |
1da177e4 | 1116 | spin_lock(&journal->j_state_lock); |
2e84f264 JK |
1117 | /* Is it already empty? */ |
1118 | if (sb->s_start == 0) { | |
1119 | spin_unlock(&journal->j_state_lock); | |
1120 | return; | |
1121 | } | |
9754e39c JK |
1122 | jbd_debug(1, "JBD: Marking journal as empty (seq %d)\n", |
1123 | journal->j_tail_sequence); | |
1124 | ||
1125 | sb->s_sequence = cpu_to_be32(journal->j_tail_sequence); | |
1126 | sb->s_start = cpu_to_be32(0); | |
1127 | spin_unlock(&journal->j_state_lock); | |
1128 | ||
fd2cbd4d | 1129 | journal_write_superblock(journal, WRITE_FUA); |
9754e39c JK |
1130 | |
1131 | spin_lock(&journal->j_state_lock); | |
1132 | /* Log is empty */ | |
1133 | journal->j_flags |= JFS_FLUSHED; | |
1da177e4 LT |
1134 | spin_unlock(&journal->j_state_lock); |
1135 | } | |
1136 | ||
9754e39c JK |
1137 | /** |
1138 | * journal_update_sb_errno() - Update error in the journal. | |
1139 | * @journal: The journal to update. | |
1140 | * | |
1141 | * Update a journal's errno. Write updated superblock to disk waiting for IO | |
1142 | * to complete. | |
1143 | */ | |
1144 | static void journal_update_sb_errno(journal_t *journal) | |
1145 | { | |
1146 | journal_superblock_t *sb = journal->j_superblock; | |
1147 | ||
1148 | spin_lock(&journal->j_state_lock); | |
1149 | jbd_debug(1, "JBD: updating superblock error (errno %d)\n", | |
1150 | journal->j_errno); | |
1151 | sb->s_errno = cpu_to_be32(journal->j_errno); | |
1152 | spin_unlock(&journal->j_state_lock); | |
1153 | ||
fd2cbd4d | 1154 | journal_write_superblock(journal, WRITE_SYNC); |
9754e39c JK |
1155 | } |
1156 | ||
1da177e4 LT |
1157 | /* |
1158 | * Read the superblock for a given journal, performing initial | |
1159 | * validation of the format. | |
1160 | */ | |
1161 | ||
1162 | static int journal_get_superblock(journal_t *journal) | |
1163 | { | |
1164 | struct buffer_head *bh; | |
1165 | journal_superblock_t *sb; | |
1166 | int err = -EIO; | |
1167 | ||
1168 | bh = journal->j_sb_buffer; | |
1169 | ||
1170 | J_ASSERT(bh != NULL); | |
1171 | if (!buffer_uptodate(bh)) { | |
1172 | ll_rw_block(READ, 1, &bh); | |
1173 | wait_on_buffer(bh); | |
1174 | if (!buffer_uptodate(bh)) { | |
1175 | printk (KERN_ERR | |
1176 | "JBD: IO error reading journal superblock\n"); | |
1177 | goto out; | |
1178 | } | |
1179 | } | |
1180 | ||
1181 | sb = journal->j_superblock; | |
1182 | ||
1183 | err = -EINVAL; | |
1184 | ||
1185 | if (sb->s_header.h_magic != cpu_to_be32(JFS_MAGIC_NUMBER) || | |
1186 | sb->s_blocksize != cpu_to_be32(journal->j_blocksize)) { | |
1187 | printk(KERN_WARNING "JBD: no valid journal superblock found\n"); | |
1188 | goto out; | |
1189 | } | |
1190 | ||
1191 | switch(be32_to_cpu(sb->s_header.h_blocktype)) { | |
1192 | case JFS_SUPERBLOCK_V1: | |
1193 | journal->j_format_version = 1; | |
1194 | break; | |
1195 | case JFS_SUPERBLOCK_V2: | |
1196 | journal->j_format_version = 2; | |
1197 | break; | |
1198 | default: | |
1199 | printk(KERN_WARNING "JBD: unrecognised superblock format ID\n"); | |
1200 | goto out; | |
1201 | } | |
1202 | ||
1203 | if (be32_to_cpu(sb->s_maxlen) < journal->j_maxlen) | |
1204 | journal->j_maxlen = be32_to_cpu(sb->s_maxlen); | |
1205 | else if (be32_to_cpu(sb->s_maxlen) > journal->j_maxlen) { | |
1206 | printk (KERN_WARNING "JBD: journal file too short\n"); | |
1207 | goto out; | |
1208 | } | |
1209 | ||
8762202d EG |
1210 | if (be32_to_cpu(sb->s_first) == 0 || |
1211 | be32_to_cpu(sb->s_first) >= journal->j_maxlen) { | |
1212 | printk(KERN_WARNING | |
1213 | "JBD: Invalid start block of journal: %u\n", | |
1214 | be32_to_cpu(sb->s_first)); | |
1215 | goto out; | |
1216 | } | |
1217 | ||
1da177e4 LT |
1218 | return 0; |
1219 | ||
1220 | out: | |
1221 | journal_fail_superblock(journal); | |
1222 | return err; | |
1223 | } | |
1224 | ||
1225 | /* | |
1226 | * Load the on-disk journal superblock and read the key fields into the | |
1227 | * journal_t. | |
1228 | */ | |
1229 | ||
1230 | static int load_superblock(journal_t *journal) | |
1231 | { | |
1232 | int err; | |
1233 | journal_superblock_t *sb; | |
1234 | ||
1235 | err = journal_get_superblock(journal); | |
1236 | if (err) | |
1237 | return err; | |
1238 | ||
1239 | sb = journal->j_superblock; | |
1240 | ||
1241 | journal->j_tail_sequence = be32_to_cpu(sb->s_sequence); | |
1242 | journal->j_tail = be32_to_cpu(sb->s_start); | |
1243 | journal->j_first = be32_to_cpu(sb->s_first); | |
1244 | journal->j_last = be32_to_cpu(sb->s_maxlen); | |
1245 | journal->j_errno = be32_to_cpu(sb->s_errno); | |
1246 | ||
1247 | return 0; | |
1248 | } | |
1249 | ||
1250 | ||
1251 | /** | |
1252 | * int journal_load() - Read journal from disk. | |
1253 | * @journal: Journal to act on. | |
ae6ddcc5 | 1254 | * |
1da177e4 LT |
1255 | * Given a journal_t structure which tells us which disk blocks contain |
1256 | * a journal, read the journal from disk to initialise the in-memory | |
1257 | * structures. | |
1258 | */ | |
1259 | int journal_load(journal_t *journal) | |
1260 | { | |
1261 | int err; | |
ea817398 | 1262 | journal_superblock_t *sb; |
1da177e4 LT |
1263 | |
1264 | err = load_superblock(journal); | |
1265 | if (err) | |
1266 | return err; | |
1267 | ||
ea817398 | 1268 | sb = journal->j_superblock; |
1da177e4 LT |
1269 | /* If this is a V2 superblock, then we have to check the |
1270 | * features flags on it. */ | |
1271 | ||
1272 | if (journal->j_format_version >= 2) { | |
1da177e4 LT |
1273 | if ((sb->s_feature_ro_compat & |
1274 | ~cpu_to_be32(JFS_KNOWN_ROCOMPAT_FEATURES)) || | |
1275 | (sb->s_feature_incompat & | |
1276 | ~cpu_to_be32(JFS_KNOWN_INCOMPAT_FEATURES))) { | |
1277 | printk (KERN_WARNING | |
1278 | "JBD: Unrecognised features on journal\n"); | |
1279 | return -EINVAL; | |
1280 | } | |
1281 | } | |
1282 | ||
1283 | /* Let the recovery code check whether it needs to recover any | |
1284 | * data from the journal. */ | |
1285 | if (journal_recover(journal)) | |
1286 | goto recovery_error; | |
1287 | ||
1288 | /* OK, we've finished with the dynamic journal bits: | |
1289 | * reinitialise the dynamic contents of the superblock in memory | |
1290 | * and reset them on disk. */ | |
1291 | if (journal_reset(journal)) | |
1292 | goto recovery_error; | |
1293 | ||
1294 | journal->j_flags &= ~JFS_ABORT; | |
1295 | journal->j_flags |= JFS_LOADED; | |
1296 | return 0; | |
1297 | ||
1298 | recovery_error: | |
1299 | printk (KERN_WARNING "JBD: recovery failed\n"); | |
1300 | return -EIO; | |
1301 | } | |
1302 | ||
1303 | /** | |
1304 | * void journal_destroy() - Release a journal_t structure. | |
1305 | * @journal: Journal to act on. | |
1306 | * | |
1307 | * Release a journal_t structure once it is no longer in use by the | |
1308 | * journaled object. | |
4afe9785 | 1309 | * Return <0 if we couldn't clean up the journal. |
1da177e4 | 1310 | */ |
4afe9785 | 1311 | int journal_destroy(journal_t *journal) |
1da177e4 | 1312 | { |
4afe9785 HK |
1313 | int err = 0; |
1314 | ||
03f4d804 | 1315 | |
1da177e4 LT |
1316 | /* Wait for the commit thread to wake up and die. */ |
1317 | journal_kill_thread(journal); | |
1318 | ||
1319 | /* Force a final log commit */ | |
1320 | if (journal->j_running_transaction) | |
1321 | journal_commit_transaction(journal); | |
1322 | ||
1323 | /* Force any old transactions to disk */ | |
1324 | ||
1ce8486d JK |
1325 | /* We cannot race with anybody but must keep assertions happy */ |
1326 | mutex_lock(&journal->j_checkpoint_mutex); | |
1da177e4 LT |
1327 | /* Totally anal locking here... */ |
1328 | spin_lock(&journal->j_list_lock); | |
1329 | while (journal->j_checkpoint_transactions != NULL) { | |
1330 | spin_unlock(&journal->j_list_lock); | |
1331 | log_do_checkpoint(journal); | |
1332 | spin_lock(&journal->j_list_lock); | |
1333 | } | |
1334 | ||
1335 | J_ASSERT(journal->j_running_transaction == NULL); | |
1336 | J_ASSERT(journal->j_committing_transaction == NULL); | |
1337 | J_ASSERT(journal->j_checkpoint_transactions == NULL); | |
1338 | spin_unlock(&journal->j_list_lock); | |
1339 | ||
1da177e4 | 1340 | if (journal->j_sb_buffer) { |
4afe9785 | 1341 | if (!is_journal_aborted(journal)) { |
4afe9785 HK |
1342 | journal->j_tail_sequence = |
1343 | ++journal->j_transaction_sequence; | |
9754e39c JK |
1344 | mark_journal_empty(journal); |
1345 | } else | |
4afe9785 | 1346 | err = -EIO; |
1da177e4 LT |
1347 | brelse(journal->j_sb_buffer); |
1348 | } | |
1ce8486d | 1349 | mutex_unlock(&journal->j_checkpoint_mutex); |
1da177e4 LT |
1350 | |
1351 | if (journal->j_inode) | |
1352 | iput(journal->j_inode); | |
1353 | if (journal->j_revoke) | |
1354 | journal_destroy_revoke(journal); | |
1355 | kfree(journal->j_wbuf); | |
1356 | kfree(journal); | |
4afe9785 HK |
1357 | |
1358 | return err; | |
1da177e4 LT |
1359 | } |
1360 | ||
1361 | ||
1362 | /** | |
1363 | *int journal_check_used_features () - Check if features specified are used. | |
1364 | * @journal: Journal to check. | |
1365 | * @compat: bitmask of compatible features | |
1366 | * @ro: bitmask of features that force read-only mount | |
1367 | * @incompat: bitmask of incompatible features | |
ae6ddcc5 | 1368 | * |
1da177e4 | 1369 | * Check whether the journal uses all of a given set of |
ae6ddcc5 | 1370 | * features. Return true (non-zero) if it does. |
1da177e4 LT |
1371 | **/ |
1372 | ||
1373 | int journal_check_used_features (journal_t *journal, unsigned long compat, | |
1374 | unsigned long ro, unsigned long incompat) | |
1375 | { | |
1376 | journal_superblock_t *sb; | |
1377 | ||
1378 | if (!compat && !ro && !incompat) | |
1379 | return 1; | |
1380 | if (journal->j_format_version == 1) | |
1381 | return 0; | |
1382 | ||
1383 | sb = journal->j_superblock; | |
1384 | ||
1385 | if (((be32_to_cpu(sb->s_feature_compat) & compat) == compat) && | |
1386 | ((be32_to_cpu(sb->s_feature_ro_compat) & ro) == ro) && | |
1387 | ((be32_to_cpu(sb->s_feature_incompat) & incompat) == incompat)) | |
1388 | return 1; | |
1389 | ||
1390 | return 0; | |
1391 | } | |
1392 | ||
1393 | /** | |
1394 | * int journal_check_available_features() - Check feature set in journalling layer | |
1395 | * @journal: Journal to check. | |
1396 | * @compat: bitmask of compatible features | |
1397 | * @ro: bitmask of features that force read-only mount | |
1398 | * @incompat: bitmask of incompatible features | |
ae6ddcc5 | 1399 | * |
1da177e4 LT |
1400 | * Check whether the journaling code supports the use of |
1401 | * all of a given set of features on this journal. Return true | |
1402 | * (non-zero) if it can. */ | |
1403 | ||
1404 | int journal_check_available_features (journal_t *journal, unsigned long compat, | |
1405 | unsigned long ro, unsigned long incompat) | |
1406 | { | |
1da177e4 LT |
1407 | if (!compat && !ro && !incompat) |
1408 | return 1; | |
1409 | ||
1da177e4 LT |
1410 | /* We can support any known requested features iff the |
1411 | * superblock is in version 2. Otherwise we fail to support any | |
1412 | * extended sb features. */ | |
1413 | ||
1414 | if (journal->j_format_version != 2) | |
1415 | return 0; | |
1416 | ||
1417 | if ((compat & JFS_KNOWN_COMPAT_FEATURES) == compat && | |
1418 | (ro & JFS_KNOWN_ROCOMPAT_FEATURES) == ro && | |
1419 | (incompat & JFS_KNOWN_INCOMPAT_FEATURES) == incompat) | |
1420 | return 1; | |
1421 | ||
1422 | return 0; | |
1423 | } | |
1424 | ||
1425 | /** | |
1426 | * int journal_set_features () - Mark a given journal feature in the superblock | |
1427 | * @journal: Journal to act on. | |
1428 | * @compat: bitmask of compatible features | |
1429 | * @ro: bitmask of features that force read-only mount | |
1430 | * @incompat: bitmask of incompatible features | |
1431 | * | |
1432 | * Mark a given journal feature as present on the | |
ae6ddcc5 | 1433 | * superblock. Returns true if the requested features could be set. |
1da177e4 LT |
1434 | * |
1435 | */ | |
1436 | ||
1437 | int journal_set_features (journal_t *journal, unsigned long compat, | |
1438 | unsigned long ro, unsigned long incompat) | |
1439 | { | |
1440 | journal_superblock_t *sb; | |
1441 | ||
1442 | if (journal_check_used_features(journal, compat, ro, incompat)) | |
1443 | return 1; | |
1444 | ||
1445 | if (!journal_check_available_features(journal, compat, ro, incompat)) | |
1446 | return 0; | |
1447 | ||
1448 | jbd_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n", | |
1449 | compat, ro, incompat); | |
1450 | ||
1451 | sb = journal->j_superblock; | |
1452 | ||
1453 | sb->s_feature_compat |= cpu_to_be32(compat); | |
1454 | sb->s_feature_ro_compat |= cpu_to_be32(ro); | |
1455 | sb->s_feature_incompat |= cpu_to_be32(incompat); | |
1456 | ||
1457 | return 1; | |
1458 | } | |
1459 | ||
1460 | ||
1461 | /** | |
1462 | * int journal_update_format () - Update on-disk journal structure. | |
1463 | * @journal: Journal to act on. | |
1464 | * | |
1465 | * Given an initialised but unloaded journal struct, poke about in the | |
1466 | * on-disk structure to update it to the most recent supported version. | |
1467 | */ | |
1468 | int journal_update_format (journal_t *journal) | |
1469 | { | |
1470 | journal_superblock_t *sb; | |
1471 | int err; | |
1472 | ||
1473 | err = journal_get_superblock(journal); | |
1474 | if (err) | |
1475 | return err; | |
1476 | ||
1477 | sb = journal->j_superblock; | |
1478 | ||
1479 | switch (be32_to_cpu(sb->s_header.h_blocktype)) { | |
1480 | case JFS_SUPERBLOCK_V2: | |
1481 | return 0; | |
1482 | case JFS_SUPERBLOCK_V1: | |
1483 | return journal_convert_superblock_v1(journal, sb); | |
1484 | default: | |
1485 | break; | |
1486 | } | |
1487 | return -EINVAL; | |
1488 | } | |
1489 | ||
1490 | static int journal_convert_superblock_v1(journal_t *journal, | |
1491 | journal_superblock_t *sb) | |
1492 | { | |
1493 | int offset, blocksize; | |
1494 | struct buffer_head *bh; | |
1495 | ||
1496 | printk(KERN_WARNING | |
1497 | "JBD: Converting superblock from version 1 to 2.\n"); | |
1498 | ||
1499 | /* Pre-initialise new fields to zero */ | |
1500 | offset = ((char *) &(sb->s_feature_compat)) - ((char *) sb); | |
1501 | blocksize = be32_to_cpu(sb->s_blocksize); | |
1502 | memset(&sb->s_feature_compat, 0, blocksize-offset); | |
1503 | ||
1504 | sb->s_nr_users = cpu_to_be32(1); | |
1505 | sb->s_header.h_blocktype = cpu_to_be32(JFS_SUPERBLOCK_V2); | |
1506 | journal->j_format_version = 2; | |
1507 | ||
1508 | bh = journal->j_sb_buffer; | |
1509 | BUFFER_TRACE(bh, "marking dirty"); | |
1510 | mark_buffer_dirty(bh); | |
1511 | sync_dirty_buffer(bh); | |
1512 | return 0; | |
1513 | } | |
1514 | ||
1515 | ||
1516 | /** | |
1517 | * int journal_flush () - Flush journal | |
1518 | * @journal: Journal to act on. | |
ae6ddcc5 | 1519 | * |
1da177e4 LT |
1520 | * Flush all data for a given journal to disk and empty the journal. |
1521 | * Filesystems can use this when remounting readonly to ensure that | |
1522 | * recovery does not need to happen on remount. | |
1523 | */ | |
1524 | ||
1525 | int journal_flush(journal_t *journal) | |
1526 | { | |
1527 | int err = 0; | |
1528 | transaction_t *transaction = NULL; | |
1da177e4 LT |
1529 | |
1530 | spin_lock(&journal->j_state_lock); | |
1531 | ||
1532 | /* Force everything buffered to the log... */ | |
1533 | if (journal->j_running_transaction) { | |
1534 | transaction = journal->j_running_transaction; | |
1535 | __log_start_commit(journal, transaction->t_tid); | |
1536 | } else if (journal->j_committing_transaction) | |
1537 | transaction = journal->j_committing_transaction; | |
1538 | ||
1539 | /* Wait for the log commit to complete... */ | |
1540 | if (transaction) { | |
1541 | tid_t tid = transaction->t_tid; | |
1542 | ||
1543 | spin_unlock(&journal->j_state_lock); | |
1544 | log_wait_commit(journal, tid); | |
1545 | } else { | |
1546 | spin_unlock(&journal->j_state_lock); | |
1547 | } | |
1548 | ||
1549 | /* ...and flush everything in the log out to disk. */ | |
1550 | spin_lock(&journal->j_list_lock); | |
1551 | while (!err && journal->j_checkpoint_transactions != NULL) { | |
1552 | spin_unlock(&journal->j_list_lock); | |
4afe9785 | 1553 | mutex_lock(&journal->j_checkpoint_mutex); |
1da177e4 | 1554 | err = log_do_checkpoint(journal); |
4afe9785 | 1555 | mutex_unlock(&journal->j_checkpoint_mutex); |
1da177e4 LT |
1556 | spin_lock(&journal->j_list_lock); |
1557 | } | |
1558 | spin_unlock(&journal->j_list_lock); | |
4afe9785 HK |
1559 | |
1560 | if (is_journal_aborted(journal)) | |
1561 | return -EIO; | |
1562 | ||
1ce8486d | 1563 | mutex_lock(&journal->j_checkpoint_mutex); |
1da177e4 LT |
1564 | cleanup_journal_tail(journal); |
1565 | ||
1566 | /* Finally, mark the journal as really needing no recovery. | |
1567 | * This sets s_start==0 in the underlying superblock, which is | |
1568 | * the magic code for a fully-recovered superblock. Any future | |
1569 | * commits of data to the journal will restore the current | |
1570 | * s_start value. */ | |
9754e39c | 1571 | mark_journal_empty(journal); |
1ce8486d | 1572 | mutex_unlock(&journal->j_checkpoint_mutex); |
1da177e4 | 1573 | spin_lock(&journal->j_state_lock); |
1da177e4 LT |
1574 | J_ASSERT(!journal->j_running_transaction); |
1575 | J_ASSERT(!journal->j_committing_transaction); | |
1576 | J_ASSERT(!journal->j_checkpoint_transactions); | |
1577 | J_ASSERT(journal->j_head == journal->j_tail); | |
1578 | J_ASSERT(journal->j_tail_sequence == journal->j_transaction_sequence); | |
1579 | spin_unlock(&journal->j_state_lock); | |
4afe9785 | 1580 | return 0; |
1da177e4 LT |
1581 | } |
1582 | ||
1583 | /** | |
1584 | * int journal_wipe() - Wipe journal contents | |
1585 | * @journal: Journal to act on. | |
1586 | * @write: flag (see below) | |
ae6ddcc5 | 1587 | * |
1da177e4 LT |
1588 | * Wipe out all of the contents of a journal, safely. This will produce |
1589 | * a warning if the journal contains any valid recovery information. | |
1590 | * Must be called between journal_init_*() and journal_load(). | |
1591 | * | |
1592 | * If 'write' is non-zero, then we wipe out the journal on disk; otherwise | |
1593 | * we merely suppress recovery. | |
1594 | */ | |
1595 | ||
1596 | int journal_wipe(journal_t *journal, int write) | |
1597 | { | |
1da177e4 LT |
1598 | int err = 0; |
1599 | ||
1600 | J_ASSERT (!(journal->j_flags & JFS_LOADED)); | |
1601 | ||
1602 | err = load_superblock(journal); | |
1603 | if (err) | |
1604 | return err; | |
1605 | ||
1da177e4 LT |
1606 | if (!journal->j_tail) |
1607 | goto no_recovery; | |
1608 | ||
1609 | printk (KERN_WARNING "JBD: %s recovery information on journal\n", | |
1610 | write ? "Clearing" : "Ignoring"); | |
1611 | ||
1612 | err = journal_skip_recovery(journal); | |
1ce8486d JK |
1613 | if (write) { |
1614 | /* Lock to make assertions happy... */ | |
1615 | mutex_lock(&journal->j_checkpoint_mutex); | |
9754e39c | 1616 | mark_journal_empty(journal); |
1ce8486d JK |
1617 | mutex_unlock(&journal->j_checkpoint_mutex); |
1618 | } | |
1da177e4 LT |
1619 | |
1620 | no_recovery: | |
1621 | return err; | |
1622 | } | |
1623 | ||
1624 | /* | |
1625 | * journal_dev_name: format a character string to describe on what | |
1626 | * device this journal is present. | |
1627 | */ | |
1628 | ||
022a4a7b | 1629 | static const char *journal_dev_name(journal_t *journal, char *buffer) |
1da177e4 LT |
1630 | { |
1631 | struct block_device *bdev; | |
1632 | ||
1633 | if (journal->j_inode) | |
1634 | bdev = journal->j_inode->i_sb->s_bdev; | |
1635 | else | |
1636 | bdev = journal->j_dev; | |
1637 | ||
1638 | return bdevname(bdev, buffer); | |
1639 | } | |
1640 | ||
1641 | /* | |
1642 | * Journal abort has very specific semantics, which we describe | |
ae6ddcc5 | 1643 | * for journal abort. |
1da177e4 LT |
1644 | * |
1645 | * Two internal function, which provide abort to te jbd layer | |
1646 | * itself are here. | |
1647 | */ | |
1648 | ||
1649 | /* | |
1650 | * Quick version for internal journal use (doesn't lock the journal). | |
1651 | * Aborts hard --- we mark the abort as occurred, but do _nothing_ else, | |
1652 | * and don't attempt to make any other journal updates. | |
1653 | */ | |
53308383 | 1654 | static void __journal_abort_hard(journal_t *journal) |
1da177e4 LT |
1655 | { |
1656 | transaction_t *transaction; | |
1657 | char b[BDEVNAME_SIZE]; | |
1658 | ||
1659 | if (journal->j_flags & JFS_ABORT) | |
1660 | return; | |
1661 | ||
1662 | printk(KERN_ERR "Aborting journal on device %s.\n", | |
1663 | journal_dev_name(journal, b)); | |
1664 | ||
1665 | spin_lock(&journal->j_state_lock); | |
1666 | journal->j_flags |= JFS_ABORT; | |
1667 | transaction = journal->j_running_transaction; | |
1668 | if (transaction) | |
1669 | __log_start_commit(journal, transaction->t_tid); | |
1670 | spin_unlock(&journal->j_state_lock); | |
1671 | } | |
1672 | ||
1673 | /* Soft abort: record the abort error status in the journal superblock, | |
1674 | * but don't do any other IO. */ | |
022a4a7b | 1675 | static void __journal_abort_soft (journal_t *journal, int errno) |
1da177e4 LT |
1676 | { |
1677 | if (journal->j_flags & JFS_ABORT) | |
1678 | return; | |
1679 | ||
1680 | if (!journal->j_errno) | |
1681 | journal->j_errno = errno; | |
1682 | ||
1683 | __journal_abort_hard(journal); | |
1684 | ||
1685 | if (errno) | |
9754e39c | 1686 | journal_update_sb_errno(journal); |
1da177e4 LT |
1687 | } |
1688 | ||
1689 | /** | |
1690 | * void journal_abort () - Shutdown the journal immediately. | |
1691 | * @journal: the journal to shutdown. | |
1692 | * @errno: an error number to record in the journal indicating | |
1693 | * the reason for the shutdown. | |
1694 | * | |
1695 | * Perform a complete, immediate shutdown of the ENTIRE | |
1696 | * journal (not of a single transaction). This operation cannot be | |
1697 | * undone without closing and reopening the journal. | |
ae6ddcc5 | 1698 | * |
1da177e4 LT |
1699 | * The journal_abort function is intended to support higher level error |
1700 | * recovery mechanisms such as the ext2/ext3 remount-readonly error | |
1701 | * mode. | |
1702 | * | |
1703 | * Journal abort has very specific semantics. Any existing dirty, | |
1704 | * unjournaled buffers in the main filesystem will still be written to | |
1705 | * disk by bdflush, but the journaling mechanism will be suspended | |
1706 | * immediately and no further transaction commits will be honoured. | |
1707 | * | |
1708 | * Any dirty, journaled buffers will be written back to disk without | |
1709 | * hitting the journal. Atomicity cannot be guaranteed on an aborted | |
1710 | * filesystem, but we _do_ attempt to leave as much data as possible | |
1711 | * behind for fsck to use for cleanup. | |
1712 | * | |
1713 | * Any attempt to get a new transaction handle on a journal which is in | |
1714 | * ABORT state will just result in an -EROFS error return. A | |
1715 | * journal_stop on an existing handle will return -EIO if we have | |
1716 | * entered abort state during the update. | |
1717 | * | |
1718 | * Recursive transactions are not disturbed by journal abort until the | |
1719 | * final journal_stop, which will receive the -EIO error. | |
1720 | * | |
1721 | * Finally, the journal_abort call allows the caller to supply an errno | |
1722 | * which will be recorded (if possible) in the journal superblock. This | |
1723 | * allows a client to record failure conditions in the middle of a | |
1724 | * transaction without having to complete the transaction to record the | |
1725 | * failure to disk. ext3_error, for example, now uses this | |
1726 | * functionality. | |
1727 | * | |
1728 | * Errors which originate from within the journaling layer will NOT | |
1729 | * supply an errno; a null errno implies that absolutely no further | |
1730 | * writes are done to the journal (unless there are any already in | |
1731 | * progress). | |
ae6ddcc5 | 1732 | * |
1da177e4 LT |
1733 | */ |
1734 | ||
1735 | void journal_abort(journal_t *journal, int errno) | |
1736 | { | |
1737 | __journal_abort_soft(journal, errno); | |
1738 | } | |
1739 | ||
ae6ddcc5 | 1740 | /** |
1da177e4 LT |
1741 | * int journal_errno () - returns the journal's error state. |
1742 | * @journal: journal to examine. | |
1743 | * | |
1744 | * This is the errno numbet set with journal_abort(), the last | |
1745 | * time the journal was mounted - if the journal was stopped | |
1746 | * without calling abort this will be 0. | |
1747 | * | |
1748 | * If the journal has been aborted on this mount time -EROFS will | |
1749 | * be returned. | |
1750 | */ | |
1751 | int journal_errno(journal_t *journal) | |
1752 | { | |
1753 | int err; | |
1754 | ||
1755 | spin_lock(&journal->j_state_lock); | |
1756 | if (journal->j_flags & JFS_ABORT) | |
1757 | err = -EROFS; | |
1758 | else | |
1759 | err = journal->j_errno; | |
1760 | spin_unlock(&journal->j_state_lock); | |
1761 | return err; | |
1762 | } | |
1763 | ||
ae6ddcc5 | 1764 | /** |
1da177e4 LT |
1765 | * int journal_clear_err () - clears the journal's error state |
1766 | * @journal: journal to act on. | |
1767 | * | |
1768 | * An error must be cleared or Acked to take a FS out of readonly | |
1769 | * mode. | |
1770 | */ | |
1771 | int journal_clear_err(journal_t *journal) | |
1772 | { | |
1773 | int err = 0; | |
1774 | ||
1775 | spin_lock(&journal->j_state_lock); | |
1776 | if (journal->j_flags & JFS_ABORT) | |
1777 | err = -EROFS; | |
1778 | else | |
1779 | journal->j_errno = 0; | |
1780 | spin_unlock(&journal->j_state_lock); | |
1781 | return err; | |
1782 | } | |
1783 | ||
ae6ddcc5 | 1784 | /** |
1da177e4 LT |
1785 | * void journal_ack_err() - Ack journal err. |
1786 | * @journal: journal to act on. | |
1787 | * | |
1788 | * An error must be cleared or Acked to take a FS out of readonly | |
1789 | * mode. | |
1790 | */ | |
1791 | void journal_ack_err(journal_t *journal) | |
1792 | { | |
1793 | spin_lock(&journal->j_state_lock); | |
1794 | if (journal->j_errno) | |
1795 | journal->j_flags |= JFS_ACK_ERR; | |
1796 | spin_unlock(&journal->j_state_lock); | |
1797 | } | |
1798 | ||
1799 | int journal_blocks_per_page(struct inode *inode) | |
1800 | { | |
1801 | return 1 << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits); | |
1802 | } | |
1803 | ||
1da177e4 LT |
1804 | /* |
1805 | * Journal_head storage management | |
1806 | */ | |
e18b890b | 1807 | static struct kmem_cache *journal_head_cache; |
1da177e4 LT |
1808 | #ifdef CONFIG_JBD_DEBUG |
1809 | static atomic_t nr_journal_heads = ATOMIC_INIT(0); | |
1810 | #endif | |
1811 | ||
1812 | static int journal_init_journal_head_cache(void) | |
1813 | { | |
1814 | int retval; | |
1815 | ||
1076d17a | 1816 | J_ASSERT(journal_head_cache == NULL); |
1da177e4 LT |
1817 | journal_head_cache = kmem_cache_create("journal_head", |
1818 | sizeof(struct journal_head), | |
1819 | 0, /* offset */ | |
e12ba74d | 1820 | SLAB_TEMPORARY, /* flags */ |
20c2df83 | 1821 | NULL); /* ctor */ |
1da177e4 | 1822 | retval = 0; |
1076d17a | 1823 | if (!journal_head_cache) { |
1da177e4 LT |
1824 | retval = -ENOMEM; |
1825 | printk(KERN_EMERG "JBD: no memory for journal_head cache\n"); | |
1826 | } | |
1827 | return retval; | |
1828 | } | |
1829 | ||
1830 | static void journal_destroy_journal_head_cache(void) | |
1831 | { | |
3850f7a5 DG |
1832 | if (journal_head_cache) { |
1833 | kmem_cache_destroy(journal_head_cache); | |
1834 | journal_head_cache = NULL; | |
1835 | } | |
1da177e4 LT |
1836 | } |
1837 | ||
1838 | /* | |
1839 | * journal_head splicing and dicing | |
1840 | */ | |
1841 | static struct journal_head *journal_alloc_journal_head(void) | |
1842 | { | |
1843 | struct journal_head *ret; | |
1da177e4 LT |
1844 | |
1845 | #ifdef CONFIG_JBD_DEBUG | |
1846 | atomic_inc(&nr_journal_heads); | |
1847 | #endif | |
1848 | ret = kmem_cache_alloc(journal_head_cache, GFP_NOFS); | |
c80544dc | 1849 | if (ret == NULL) { |
1da177e4 | 1850 | jbd_debug(1, "out of memory for journal_head\n"); |
f81e3d45 NK |
1851 | printk_ratelimited(KERN_NOTICE "ENOMEM in %s, retrying.\n", |
1852 | __func__); | |
1853 | ||
c80544dc | 1854 | while (ret == NULL) { |
1da177e4 LT |
1855 | yield(); |
1856 | ret = kmem_cache_alloc(journal_head_cache, GFP_NOFS); | |
1857 | } | |
1858 | } | |
1859 | return ret; | |
1860 | } | |
1861 | ||
1862 | static void journal_free_journal_head(struct journal_head *jh) | |
1863 | { | |
1864 | #ifdef CONFIG_JBD_DEBUG | |
1865 | atomic_dec(&nr_journal_heads); | |
c9cf5528 | 1866 | memset(jh, JBD_POISON_FREE, sizeof(*jh)); |
1da177e4 LT |
1867 | #endif |
1868 | kmem_cache_free(journal_head_cache, jh); | |
1869 | } | |
1870 | ||
1871 | /* | |
1872 | * A journal_head is attached to a buffer_head whenever JBD has an | |
1873 | * interest in the buffer. | |
1874 | * | |
1875 | * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit | |
1876 | * is set. This bit is tested in core kernel code where we need to take | |
1877 | * JBD-specific actions. Testing the zeroness of ->b_private is not reliable | |
1878 | * there. | |
1879 | * | |
1880 | * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one. | |
1881 | * | |
1882 | * When a buffer has its BH_JBD bit set it is immune from being released by | |
1883 | * core kernel code, mainly via ->b_count. | |
1884 | * | |
bb189247 JK |
1885 | * A journal_head is detached from its buffer_head when the journal_head's |
1886 | * b_jcount reaches zero. Running transaction (b_transaction) and checkpoint | |
1887 | * transaction (b_cp_transaction) hold their references to b_jcount. | |
1da177e4 LT |
1888 | * |
1889 | * Various places in the kernel want to attach a journal_head to a buffer_head | |
1890 | * _before_ attaching the journal_head to a transaction. To protect the | |
1891 | * journal_head in this situation, journal_add_journal_head elevates the | |
1892 | * journal_head's b_jcount refcount by one. The caller must call | |
1893 | * journal_put_journal_head() to undo this. | |
1894 | * | |
1895 | * So the typical usage would be: | |
1896 | * | |
1897 | * (Attach a journal_head if needed. Increments b_jcount) | |
1898 | * struct journal_head *jh = journal_add_journal_head(bh); | |
1899 | * ... | |
bb189247 JK |
1900 | * (Get another reference for transaction) |
1901 | * journal_grab_journal_head(bh); | |
1902 | * jh->b_transaction = xxx; | |
1903 | * (Put original reference) | |
1904 | * journal_put_journal_head(jh); | |
1da177e4 LT |
1905 | */ |
1906 | ||
1907 | /* | |
1908 | * Give a buffer_head a journal_head. | |
1909 | * | |
1da177e4 LT |
1910 | * May sleep. |
1911 | */ | |
1912 | struct journal_head *journal_add_journal_head(struct buffer_head *bh) | |
1913 | { | |
1914 | struct journal_head *jh; | |
1915 | struct journal_head *new_jh = NULL; | |
1916 | ||
1917 | repeat: | |
1918 | if (!buffer_jbd(bh)) { | |
1919 | new_jh = journal_alloc_journal_head(); | |
1920 | memset(new_jh, 0, sizeof(*new_jh)); | |
1921 | } | |
1922 | ||
1923 | jbd_lock_bh_journal_head(bh); | |
1924 | if (buffer_jbd(bh)) { | |
1925 | jh = bh2jh(bh); | |
1926 | } else { | |
1927 | J_ASSERT_BH(bh, | |
1928 | (atomic_read(&bh->b_count) > 0) || | |
1929 | (bh->b_page && bh->b_page->mapping)); | |
1930 | ||
1931 | if (!new_jh) { | |
1932 | jbd_unlock_bh_journal_head(bh); | |
1933 | goto repeat; | |
1934 | } | |
1935 | ||
1936 | jh = new_jh; | |
1937 | new_jh = NULL; /* We consumed it */ | |
1938 | set_buffer_jbd(bh); | |
1939 | bh->b_private = jh; | |
1940 | jh->b_bh = bh; | |
1941 | get_bh(bh); | |
1942 | BUFFER_TRACE(bh, "added journal_head"); | |
1943 | } | |
1944 | jh->b_jcount++; | |
1945 | jbd_unlock_bh_journal_head(bh); | |
1946 | if (new_jh) | |
1947 | journal_free_journal_head(new_jh); | |
1948 | return bh->b_private; | |
1949 | } | |
1950 | ||
1951 | /* | |
1952 | * Grab a ref against this buffer_head's journal_head. If it ended up not | |
1953 | * having a journal_head, return NULL | |
1954 | */ | |
1955 | struct journal_head *journal_grab_journal_head(struct buffer_head *bh) | |
1956 | { | |
1957 | struct journal_head *jh = NULL; | |
1958 | ||
1959 | jbd_lock_bh_journal_head(bh); | |
1960 | if (buffer_jbd(bh)) { | |
1961 | jh = bh2jh(bh); | |
1962 | jh->b_jcount++; | |
1963 | } | |
1964 | jbd_unlock_bh_journal_head(bh); | |
1965 | return jh; | |
1966 | } | |
1967 | ||
1968 | static void __journal_remove_journal_head(struct buffer_head *bh) | |
1969 | { | |
1970 | struct journal_head *jh = bh2jh(bh); | |
1971 | ||
1972 | J_ASSERT_JH(jh, jh->b_jcount >= 0); | |
bb189247 JK |
1973 | J_ASSERT_JH(jh, jh->b_transaction == NULL); |
1974 | J_ASSERT_JH(jh, jh->b_next_transaction == NULL); | |
1975 | J_ASSERT_JH(jh, jh->b_cp_transaction == NULL); | |
1976 | J_ASSERT_JH(jh, jh->b_jlist == BJ_None); | |
1977 | J_ASSERT_BH(bh, buffer_jbd(bh)); | |
1978 | J_ASSERT_BH(bh, jh2bh(jh) == bh); | |
1979 | BUFFER_TRACE(bh, "remove journal_head"); | |
1980 | if (jh->b_frozen_data) { | |
1981 | printk(KERN_WARNING "%s: freeing b_frozen_data\n", __func__); | |
1982 | jbd_free(jh->b_frozen_data, bh->b_size); | |
1da177e4 | 1983 | } |
bb189247 JK |
1984 | if (jh->b_committed_data) { |
1985 | printk(KERN_WARNING "%s: freeing b_committed_data\n", __func__); | |
1986 | jbd_free(jh->b_committed_data, bh->b_size); | |
1987 | } | |
1988 | bh->b_private = NULL; | |
1989 | jh->b_bh = NULL; /* debug, really */ | |
1990 | clear_buffer_jbd(bh); | |
1991 | journal_free_journal_head(jh); | |
1da177e4 LT |
1992 | } |
1993 | ||
1994 | /* | |
bb189247 | 1995 | * Drop a reference on the passed journal_head. If it fell to zero then |
1da177e4 LT |
1996 | * release the journal_head from the buffer_head. |
1997 | */ | |
1998 | void journal_put_journal_head(struct journal_head *jh) | |
1999 | { | |
2000 | struct buffer_head *bh = jh2bh(jh); | |
2001 | ||
2002 | jbd_lock_bh_journal_head(bh); | |
2003 | J_ASSERT_JH(jh, jh->b_jcount > 0); | |
2004 | --jh->b_jcount; | |
bb189247 | 2005 | if (!jh->b_jcount) { |
1da177e4 | 2006 | __journal_remove_journal_head(bh); |
bb189247 | 2007 | jbd_unlock_bh_journal_head(bh); |
1da177e4 | 2008 | __brelse(bh); |
bb189247 JK |
2009 | } else |
2010 | jbd_unlock_bh_journal_head(bh); | |
1da177e4 LT |
2011 | } |
2012 | ||
2013 | /* | |
c2a9159c | 2014 | * debugfs tunables |
1da177e4 | 2015 | */ |
c2a9159c | 2016 | #ifdef CONFIG_JBD_DEBUG |
1da177e4 | 2017 | |
c2a9159c JS |
2018 | u8 journal_enable_debug __read_mostly; |
2019 | EXPORT_SYMBOL(journal_enable_debug); | |
1da177e4 | 2020 | |
c2a9159c JS |
2021 | static struct dentry *jbd_debugfs_dir; |
2022 | static struct dentry *jbd_debug; | |
1da177e4 | 2023 | |
c2a9159c | 2024 | static void __init jbd_create_debugfs_entry(void) |
1da177e4 | 2025 | { |
c2a9159c JS |
2026 | jbd_debugfs_dir = debugfs_create_dir("jbd", NULL); |
2027 | if (jbd_debugfs_dir) | |
765f8361 | 2028 | jbd_debug = debugfs_create_u8("jbd-debug", S_IRUGO | S_IWUSR, |
c2a9159c JS |
2029 | jbd_debugfs_dir, |
2030 | &journal_enable_debug); | |
1da177e4 LT |
2031 | } |
2032 | ||
c2a9159c | 2033 | static void __exit jbd_remove_debugfs_entry(void) |
1da177e4 | 2034 | { |
c2a9159c JS |
2035 | debugfs_remove(jbd_debug); |
2036 | debugfs_remove(jbd_debugfs_dir); | |
1da177e4 LT |
2037 | } |
2038 | ||
c2a9159c | 2039 | #else |
1da177e4 | 2040 | |
c2a9159c | 2041 | static inline void jbd_create_debugfs_entry(void) |
1da177e4 | 2042 | { |
1da177e4 LT |
2043 | } |
2044 | ||
c2a9159c | 2045 | static inline void jbd_remove_debugfs_entry(void) |
1da177e4 | 2046 | { |
1da177e4 LT |
2047 | } |
2048 | ||
1da177e4 LT |
2049 | #endif |
2050 | ||
e18b890b | 2051 | struct kmem_cache *jbd_handle_cache; |
1da177e4 LT |
2052 | |
2053 | static int __init journal_init_handle_cache(void) | |
2054 | { | |
2055 | jbd_handle_cache = kmem_cache_create("journal_handle", | |
2056 | sizeof(handle_t), | |
2057 | 0, /* offset */ | |
e12ba74d | 2058 | SLAB_TEMPORARY, /* flags */ |
20c2df83 | 2059 | NULL); /* ctor */ |
1da177e4 LT |
2060 | if (jbd_handle_cache == NULL) { |
2061 | printk(KERN_EMERG "JBD: failed to create handle cache\n"); | |
2062 | return -ENOMEM; | |
2063 | } | |
2064 | return 0; | |
2065 | } | |
2066 | ||
2067 | static void journal_destroy_handle_cache(void) | |
2068 | { | |
2069 | if (jbd_handle_cache) | |
2070 | kmem_cache_destroy(jbd_handle_cache); | |
2071 | } | |
2072 | ||
2073 | /* | |
2074 | * Module startup and shutdown | |
2075 | */ | |
2076 | ||
2077 | static int __init journal_init_caches(void) | |
2078 | { | |
2079 | int ret; | |
2080 | ||
2081 | ret = journal_init_revoke_caches(); | |
2082 | if (ret == 0) | |
2083 | ret = journal_init_journal_head_cache(); | |
2084 | if (ret == 0) | |
2085 | ret = journal_init_handle_cache(); | |
2086 | return ret; | |
2087 | } | |
2088 | ||
2089 | static void journal_destroy_caches(void) | |
2090 | { | |
2091 | journal_destroy_revoke_caches(); | |
2092 | journal_destroy_journal_head_cache(); | |
2093 | journal_destroy_handle_cache(); | |
2094 | } | |
2095 | ||
2096 | static int __init journal_init(void) | |
2097 | { | |
2098 | int ret; | |
2099 | ||
2aed3484 | 2100 | BUILD_BUG_ON(sizeof(struct journal_superblock_s) != 1024); |
022a4a7b | 2101 | |
1da177e4 LT |
2102 | ret = journal_init_caches(); |
2103 | if (ret != 0) | |
2104 | journal_destroy_caches(); | |
c2a9159c | 2105 | jbd_create_debugfs_entry(); |
1da177e4 LT |
2106 | return ret; |
2107 | } | |
2108 | ||
2109 | static void __exit journal_exit(void) | |
2110 | { | |
2111 | #ifdef CONFIG_JBD_DEBUG | |
2112 | int n = atomic_read(&nr_journal_heads); | |
2113 | if (n) | |
2114 | printk(KERN_EMERG "JBD: leaked %d journal_heads!\n", n); | |
2115 | #endif | |
c2a9159c | 2116 | jbd_remove_debugfs_entry(); |
1da177e4 LT |
2117 | journal_destroy_caches(); |
2118 | } | |
2119 | ||
2120 | MODULE_LICENSE("GPL"); | |
2121 | module_init(journal_init); | |
2122 | module_exit(journal_exit); | |
2123 |