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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 | */ |
d9b01934 TT |
449 | if (journal->j_running_transaction && |
450 | journal->j_running_transaction->t_tid == target) { | |
1da177e4 | 451 | /* |
bcf3d0bc | 452 | * We want a new commit: OK, mark the request and wakeup the |
1da177e4 LT |
453 | * commit thread. We do _not_ do the commit ourselves. |
454 | */ | |
455 | ||
456 | journal->j_commit_request = target; | |
457 | jbd_debug(1, "JBD: requesting commit %d/%d\n", | |
458 | journal->j_commit_request, | |
459 | journal->j_commit_sequence); | |
460 | wake_up(&journal->j_wait_commit); | |
461 | return 1; | |
d9b01934 TT |
462 | } else if (!tid_geq(journal->j_commit_request, target)) |
463 | /* This should never happen, but if it does, preserve | |
464 | the evidence before kjournald goes into a loop and | |
465 | increments j_commit_sequence beyond all recognition. */ | |
466 | WARN_ONCE(1, "jbd: bad log_start_commit: %u %u %u %u\n", | |
467 | journal->j_commit_request, journal->j_commit_sequence, | |
468 | target, journal->j_running_transaction ? | |
469 | journal->j_running_transaction->t_tid : 0); | |
1da177e4 LT |
470 | return 0; |
471 | } | |
472 | ||
473 | int log_start_commit(journal_t *journal, tid_t tid) | |
474 | { | |
475 | int ret; | |
476 | ||
477 | spin_lock(&journal->j_state_lock); | |
478 | ret = __log_start_commit(journal, tid); | |
479 | spin_unlock(&journal->j_state_lock); | |
480 | return ret; | |
481 | } | |
482 | ||
483 | /* | |
484 | * Force and wait upon a commit if the calling process is not within | |
485 | * transaction. This is used for forcing out undo-protected data which contains | |
486 | * bitmaps, when the fs is running out of space. | |
487 | * | |
488 | * We can only force the running transaction if we don't have an active handle; | |
489 | * otherwise, we will deadlock. | |
490 | * | |
491 | * Returns true if a transaction was started. | |
492 | */ | |
493 | int journal_force_commit_nested(journal_t *journal) | |
494 | { | |
495 | transaction_t *transaction = NULL; | |
496 | tid_t tid; | |
497 | ||
498 | spin_lock(&journal->j_state_lock); | |
499 | if (journal->j_running_transaction && !current->journal_info) { | |
500 | transaction = journal->j_running_transaction; | |
501 | __log_start_commit(journal, transaction->t_tid); | |
502 | } else if (journal->j_committing_transaction) | |
503 | transaction = journal->j_committing_transaction; | |
504 | ||
505 | if (!transaction) { | |
506 | spin_unlock(&journal->j_state_lock); | |
507 | return 0; /* Nothing to retry */ | |
508 | } | |
509 | ||
510 | tid = transaction->t_tid; | |
511 | spin_unlock(&journal->j_state_lock); | |
512 | log_wait_commit(journal, tid); | |
513 | return 1; | |
514 | } | |
515 | ||
516 | /* | |
517 | * Start a commit of the current running transaction (if any). Returns true | |
8fe4cd0d JK |
518 | * if a transaction is going to be committed (or is currently already |
519 | * committing), and fills its tid in at *ptid | |
1da177e4 LT |
520 | */ |
521 | int journal_start_commit(journal_t *journal, tid_t *ptid) | |
522 | { | |
523 | int ret = 0; | |
524 | ||
525 | spin_lock(&journal->j_state_lock); | |
526 | if (journal->j_running_transaction) { | |
527 | tid_t tid = journal->j_running_transaction->t_tid; | |
528 | ||
8fe4cd0d JK |
529 | __log_start_commit(journal, tid); |
530 | /* There's a running transaction and we've just made sure | |
531 | * it's commit has been scheduled. */ | |
532 | if (ptid) | |
1da177e4 | 533 | *ptid = tid; |
8fe4cd0d JK |
534 | ret = 1; |
535 | } else if (journal->j_committing_transaction) { | |
1da177e4 LT |
536 | /* |
537 | * If ext3_write_super() recently started a commit, then we | |
538 | * have to wait for completion of that transaction | |
539 | */ | |
8fe4cd0d JK |
540 | if (ptid) |
541 | *ptid = journal->j_committing_transaction->t_tid; | |
1da177e4 LT |
542 | ret = 1; |
543 | } | |
544 | spin_unlock(&journal->j_state_lock); | |
545 | return ret; | |
546 | } | |
547 | ||
548 | /* | |
549 | * Wait for a specified commit to complete. | |
550 | * The caller may not hold the journal lock. | |
551 | */ | |
552 | int log_wait_commit(journal_t *journal, tid_t tid) | |
553 | { | |
554 | int err = 0; | |
555 | ||
556 | #ifdef CONFIG_JBD_DEBUG | |
557 | spin_lock(&journal->j_state_lock); | |
558 | if (!tid_geq(journal->j_commit_request, tid)) { | |
559 | printk(KERN_EMERG | |
560 | "%s: error: j_commit_request=%d, tid=%d\n", | |
08fc99bf | 561 | __func__, journal->j_commit_request, tid); |
1da177e4 LT |
562 | } |
563 | spin_unlock(&journal->j_state_lock); | |
564 | #endif | |
565 | spin_lock(&journal->j_state_lock); | |
566 | while (tid_gt(tid, journal->j_commit_sequence)) { | |
567 | jbd_debug(1, "JBD: want %d, j_commit_sequence=%d\n", | |
568 | tid, journal->j_commit_sequence); | |
569 | wake_up(&journal->j_wait_commit); | |
570 | spin_unlock(&journal->j_state_lock); | |
571 | wait_event(journal->j_wait_done_commit, | |
572 | !tid_gt(tid, journal->j_commit_sequence)); | |
573 | spin_lock(&journal->j_state_lock); | |
574 | } | |
575 | spin_unlock(&journal->j_state_lock); | |
576 | ||
577 | if (unlikely(is_journal_aborted(journal))) { | |
578 | printk(KERN_EMERG "journal commit I/O error\n"); | |
579 | err = -EIO; | |
580 | } | |
581 | return err; | |
582 | } | |
583 | ||
03f4d804 JK |
584 | /* |
585 | * Return 1 if a given transaction has not yet sent barrier request | |
586 | * connected with a transaction commit. If 0 is returned, transaction | |
587 | * may or may not have sent the barrier. Used to avoid sending barrier | |
588 | * twice in common cases. | |
589 | */ | |
590 | int journal_trans_will_send_data_barrier(journal_t *journal, tid_t tid) | |
591 | { | |
592 | int ret = 0; | |
593 | transaction_t *commit_trans; | |
594 | ||
595 | if (!(journal->j_flags & JFS_BARRIER)) | |
596 | return 0; | |
597 | spin_lock(&journal->j_state_lock); | |
598 | /* Transaction already committed? */ | |
599 | if (tid_geq(journal->j_commit_sequence, tid)) | |
600 | goto out; | |
601 | /* | |
602 | * Transaction is being committed and we already proceeded to | |
603 | * writing commit record? | |
604 | */ | |
605 | commit_trans = journal->j_committing_transaction; | |
606 | if (commit_trans && commit_trans->t_tid == tid && | |
607 | commit_trans->t_state >= T_COMMIT_RECORD) | |
608 | goto out; | |
609 | ret = 1; | |
610 | out: | |
611 | spin_unlock(&journal->j_state_lock); | |
612 | return ret; | |
613 | } | |
52779708 | 614 | EXPORT_SYMBOL(journal_trans_will_send_data_barrier); |
03f4d804 | 615 | |
1da177e4 LT |
616 | /* |
617 | * Log buffer allocation routines: | |
618 | */ | |
619 | ||
9c28cbcc | 620 | int journal_next_log_block(journal_t *journal, unsigned int *retp) |
1da177e4 | 621 | { |
9c28cbcc | 622 | unsigned int blocknr; |
1da177e4 LT |
623 | |
624 | spin_lock(&journal->j_state_lock); | |
625 | J_ASSERT(journal->j_free > 1); | |
626 | ||
627 | blocknr = journal->j_head; | |
628 | journal->j_head++; | |
629 | journal->j_free--; | |
630 | if (journal->j_head == journal->j_last) | |
631 | journal->j_head = journal->j_first; | |
632 | spin_unlock(&journal->j_state_lock); | |
633 | return journal_bmap(journal, blocknr, retp); | |
634 | } | |
635 | ||
636 | /* | |
637 | * Conversion of logical to physical block numbers for the journal | |
638 | * | |
639 | * On external journals the journal blocks are identity-mapped, so | |
640 | * this is a no-op. If needed, we can use j_blk_offset - everything is | |
641 | * ready. | |
642 | */ | |
9c28cbcc JK |
643 | int journal_bmap(journal_t *journal, unsigned int blocknr, |
644 | unsigned int *retp) | |
1da177e4 LT |
645 | { |
646 | int err = 0; | |
9c28cbcc | 647 | unsigned int ret; |
1da177e4 LT |
648 | |
649 | if (journal->j_inode) { | |
650 | ret = bmap(journal->j_inode, blocknr); | |
651 | if (ret) | |
652 | *retp = ret; | |
653 | else { | |
654 | char b[BDEVNAME_SIZE]; | |
655 | ||
656 | printk(KERN_ALERT "%s: journal block not found " | |
9c28cbcc | 657 | "at offset %u on %s\n", |
08fc99bf | 658 | __func__, |
1da177e4 LT |
659 | blocknr, |
660 | bdevname(journal->j_dev, b)); | |
661 | err = -EIO; | |
662 | __journal_abort_soft(journal, err); | |
663 | } | |
664 | } else { | |
665 | *retp = blocknr; /* +journal->j_blk_offset */ | |
666 | } | |
667 | return err; | |
668 | } | |
669 | ||
670 | /* | |
671 | * We play buffer_head aliasing tricks to write data/metadata blocks to | |
672 | * the journal without copying their contents, but for journal | |
673 | * descriptor blocks we do need to generate bona fide buffers. | |
674 | * | |
675 | * After the caller of journal_get_descriptor_buffer() has finished modifying | |
676 | * the buffer's contents they really should run flush_dcache_page(bh->b_page). | |
677 | * But we don't bother doing that, so there will be coherency problems with | |
678 | * mmaps of blockdevs which hold live JBD-controlled filesystems. | |
679 | */ | |
680 | struct journal_head *journal_get_descriptor_buffer(journal_t *journal) | |
681 | { | |
682 | struct buffer_head *bh; | |
9c28cbcc | 683 | unsigned int blocknr; |
1da177e4 LT |
684 | int err; |
685 | ||
686 | err = journal_next_log_block(journal, &blocknr); | |
687 | ||
688 | if (err) | |
689 | return NULL; | |
690 | ||
691 | bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); | |
ecca9af0 JK |
692 | if (!bh) |
693 | return NULL; | |
1da177e4 LT |
694 | lock_buffer(bh); |
695 | memset(bh->b_data, 0, journal->j_blocksize); | |
696 | set_buffer_uptodate(bh); | |
697 | unlock_buffer(bh); | |
698 | BUFFER_TRACE(bh, "return this buffer"); | |
699 | return journal_add_journal_head(bh); | |
700 | } | |
701 | ||
702 | /* | |
703 | * Management for journal control blocks: functions to create and | |
704 | * destroy journal_t structures, and to initialise and read existing | |
705 | * journal blocks from disk. */ | |
706 | ||
707 | /* First: create and setup a journal_t object in memory. We initialise | |
708 | * very few fields yet: that has to wait until we have created the | |
709 | * journal structures from from scratch, or loaded them from disk. */ | |
710 | ||
711 | static journal_t * journal_init_common (void) | |
712 | { | |
713 | journal_t *journal; | |
714 | int err; | |
715 | ||
8c3478a5 | 716 | journal = kzalloc(sizeof(*journal), GFP_KERNEL); |
1da177e4 LT |
717 | if (!journal) |
718 | goto fail; | |
1da177e4 LT |
719 | |
720 | init_waitqueue_head(&journal->j_wait_transaction_locked); | |
721 | init_waitqueue_head(&journal->j_wait_logspace); | |
722 | init_waitqueue_head(&journal->j_wait_done_commit); | |
723 | init_waitqueue_head(&journal->j_wait_checkpoint); | |
724 | init_waitqueue_head(&journal->j_wait_commit); | |
725 | init_waitqueue_head(&journal->j_wait_updates); | |
2c68ee75 | 726 | mutex_init(&journal->j_checkpoint_mutex); |
1da177e4 LT |
727 | spin_lock_init(&journal->j_revoke_lock); |
728 | spin_lock_init(&journal->j_list_lock); | |
729 | spin_lock_init(&journal->j_state_lock); | |
730 | ||
731 | journal->j_commit_interval = (HZ * JBD_DEFAULT_MAX_COMMIT_AGE); | |
732 | ||
733 | /* The journal is marked for error until we succeed with recovery! */ | |
734 | journal->j_flags = JFS_ABORT; | |
735 | ||
736 | /* Set up a default-sized revoke table for the new mount. */ | |
737 | err = journal_init_revoke(journal, JOURNAL_REVOKE_DEFAULT_HASH); | |
738 | if (err) { | |
739 | kfree(journal); | |
740 | goto fail; | |
741 | } | |
742 | return journal; | |
743 | fail: | |
744 | return NULL; | |
745 | } | |
746 | ||
747 | /* journal_init_dev and journal_init_inode: | |
748 | * | |
749 | * Create a journal structure assigned some fixed set of disk blocks to | |
750 | * the journal. We don't actually touch those disk blocks yet, but we | |
751 | * need to set up all of the mapping information to tell the journaling | |
752 | * system where the journal blocks are. | |
753 | * | |
754 | */ | |
755 | ||
756 | /** | |
0cf01f66 | 757 | * journal_t * journal_init_dev() - creates and initialises a journal structure |
1da177e4 LT |
758 | * @bdev: Block device on which to create the journal |
759 | * @fs_dev: Device which hold journalled filesystem for this journal. | |
760 | * @start: Block nr Start of journal. | |
37ed3222 | 761 | * @len: Length of the journal in blocks. |
1da177e4 | 762 | * @blocksize: blocksize of journalling device |
0cf01f66 RD |
763 | * |
764 | * Returns: a newly created journal_t * | |
ae6ddcc5 | 765 | * |
1da177e4 LT |
766 | * journal_init_dev creates a journal which maps a fixed contiguous |
767 | * range of blocks on an arbitrary block device. | |
ae6ddcc5 | 768 | * |
1da177e4 LT |
769 | */ |
770 | journal_t * journal_init_dev(struct block_device *bdev, | |
771 | struct block_device *fs_dev, | |
772 | int start, int len, int blocksize) | |
773 | { | |
774 | journal_t *journal = journal_init_common(); | |
775 | struct buffer_head *bh; | |
776 | int n; | |
777 | ||
778 | if (!journal) | |
779 | return NULL; | |
780 | ||
1da177e4 | 781 | /* journal descriptor can store up to n blocks -bzzz */ |
d1807793 | 782 | journal->j_blocksize = blocksize; |
1da177e4 LT |
783 | n = journal->j_blocksize / sizeof(journal_block_tag_t); |
784 | journal->j_wbufsize = n; | |
785 | journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL); | |
786 | if (!journal->j_wbuf) { | |
25985edc | 787 | printk(KERN_ERR "%s: Can't allocate bhs for commit thread\n", |
08fc99bf | 788 | __func__); |
ecca9af0 | 789 | goto out_err; |
1da177e4 | 790 | } |
d1807793 ZM |
791 | journal->j_dev = bdev; |
792 | journal->j_fs_dev = fs_dev; | |
793 | journal->j_blk_offset = start; | |
794 | journal->j_maxlen = len; | |
795 | ||
796 | bh = __getblk(journal->j_dev, start, journal->j_blocksize); | |
ecca9af0 JK |
797 | if (!bh) { |
798 | printk(KERN_ERR | |
799 | "%s: Cannot get buffer for journal superblock\n", | |
800 | __func__); | |
801 | goto out_err; | |
802 | } | |
d1807793 ZM |
803 | journal->j_sb_buffer = bh; |
804 | journal->j_superblock = (journal_superblock_t *)bh->b_data; | |
ecca9af0 | 805 | |
1da177e4 | 806 | return journal; |
ecca9af0 | 807 | out_err: |
7b02bec0 | 808 | kfree(journal->j_wbuf); |
ecca9af0 JK |
809 | kfree(journal); |
810 | return NULL; | |
1da177e4 | 811 | } |
ae6ddcc5 MC |
812 | |
813 | /** | |
1da177e4 LT |
814 | * journal_t * journal_init_inode () - creates a journal which maps to a inode. |
815 | * @inode: An inode to create the journal in | |
ae6ddcc5 | 816 | * |
1da177e4 LT |
817 | * journal_init_inode creates a journal which maps an on-disk inode as |
818 | * the journal. The inode must exist already, must support bmap() and | |
819 | * must have all data blocks preallocated. | |
820 | */ | |
821 | journal_t * journal_init_inode (struct inode *inode) | |
822 | { | |
823 | struct buffer_head *bh; | |
824 | journal_t *journal = journal_init_common(); | |
825 | int err; | |
826 | int n; | |
9c28cbcc | 827 | unsigned int blocknr; |
1da177e4 LT |
828 | |
829 | if (!journal) | |
830 | return NULL; | |
831 | ||
832 | journal->j_dev = journal->j_fs_dev = inode->i_sb->s_bdev; | |
833 | journal->j_inode = inode; | |
834 | jbd_debug(1, | |
835 | "journal %p: inode %s/%ld, size %Ld, bits %d, blksize %ld\n", | |
ae6ddcc5 | 836 | journal, inode->i_sb->s_id, inode->i_ino, |
1da177e4 LT |
837 | (long long) inode->i_size, |
838 | inode->i_sb->s_blocksize_bits, inode->i_sb->s_blocksize); | |
839 | ||
840 | journal->j_maxlen = inode->i_size >> inode->i_sb->s_blocksize_bits; | |
841 | journal->j_blocksize = inode->i_sb->s_blocksize; | |
842 | ||
843 | /* journal descriptor can store up to n blocks -bzzz */ | |
844 | n = journal->j_blocksize / sizeof(journal_block_tag_t); | |
845 | journal->j_wbufsize = n; | |
846 | journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL); | |
847 | if (!journal->j_wbuf) { | |
25985edc | 848 | printk(KERN_ERR "%s: Can't allocate bhs for commit thread\n", |
08fc99bf | 849 | __func__); |
ecca9af0 | 850 | goto out_err; |
1da177e4 LT |
851 | } |
852 | ||
853 | err = journal_bmap(journal, 0, &blocknr); | |
854 | /* If that failed, give up */ | |
855 | if (err) { | |
3c26bdb4 | 856 | printk(KERN_ERR "%s: Cannot locate journal superblock\n", |
08fc99bf | 857 | __func__); |
ecca9af0 | 858 | goto out_err; |
1da177e4 LT |
859 | } |
860 | ||
861 | bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); | |
ecca9af0 JK |
862 | if (!bh) { |
863 | printk(KERN_ERR | |
864 | "%s: Cannot get buffer for journal superblock\n", | |
865 | __func__); | |
866 | goto out_err; | |
867 | } | |
1da177e4 LT |
868 | journal->j_sb_buffer = bh; |
869 | journal->j_superblock = (journal_superblock_t *)bh->b_data; | |
870 | ||
871 | return journal; | |
ecca9af0 | 872 | out_err: |
7b02bec0 | 873 | kfree(journal->j_wbuf); |
ecca9af0 JK |
874 | kfree(journal); |
875 | return NULL; | |
1da177e4 LT |
876 | } |
877 | ||
ae6ddcc5 | 878 | /* |
1da177e4 LT |
879 | * If the journal init or create aborts, we need to mark the journal |
880 | * superblock as being NULL to prevent the journal destroy from writing | |
ae6ddcc5 | 881 | * back a bogus superblock. |
1da177e4 LT |
882 | */ |
883 | static void journal_fail_superblock (journal_t *journal) | |
884 | { | |
885 | struct buffer_head *bh = journal->j_sb_buffer; | |
886 | brelse(bh); | |
887 | journal->j_sb_buffer = NULL; | |
888 | } | |
889 | ||
890 | /* | |
891 | * Given a journal_t structure, initialise the various fields for | |
892 | * startup of a new journaling session. We use this both when creating | |
893 | * a journal, and after recovering an old journal to reset it for | |
894 | * subsequent use. | |
895 | */ | |
896 | ||
897 | static int journal_reset(journal_t *journal) | |
898 | { | |
899 | journal_superblock_t *sb = journal->j_superblock; | |
9c28cbcc | 900 | unsigned int first, last; |
1da177e4 LT |
901 | |
902 | first = be32_to_cpu(sb->s_first); | |
903 | last = be32_to_cpu(sb->s_maxlen); | |
7447a668 | 904 | if (first + JFS_MIN_JOURNAL_BLOCKS > last + 1) { |
9c28cbcc | 905 | printk(KERN_ERR "JBD: Journal too short (blocks %u-%u).\n", |
7447a668 JK |
906 | first, last); |
907 | journal_fail_superblock(journal); | |
908 | return -EINVAL; | |
909 | } | |
1da177e4 LT |
910 | |
911 | journal->j_first = first; | |
912 | journal->j_last = last; | |
913 | ||
914 | journal->j_head = first; | |
915 | journal->j_tail = first; | |
916 | journal->j_free = last - first; | |
917 | ||
918 | journal->j_tail_sequence = journal->j_transaction_sequence; | |
919 | journal->j_commit_sequence = journal->j_transaction_sequence - 1; | |
920 | journal->j_commit_request = journal->j_commit_sequence; | |
921 | ||
922 | journal->j_max_transaction_buffers = journal->j_maxlen / 4; | |
923 | ||
924 | /* Add the dynamic fields and write it to disk. */ | |
925 | journal_update_superblock(journal, 1); | |
97f06784 | 926 | return journal_start_thread(journal); |
1da177e4 LT |
927 | } |
928 | ||
ae6ddcc5 | 929 | /** |
1da177e4 LT |
930 | * int journal_create() - Initialise the new journal file |
931 | * @journal: Journal to create. This structure must have been initialised | |
ae6ddcc5 | 932 | * |
1da177e4 LT |
933 | * Given a journal_t structure which tells us which disk blocks we can |
934 | * use, create a new journal superblock and initialise all of the | |
ae6ddcc5 | 935 | * journal fields from scratch. |
1da177e4 LT |
936 | **/ |
937 | int journal_create(journal_t *journal) | |
938 | { | |
9c28cbcc | 939 | unsigned int blocknr; |
1da177e4 LT |
940 | struct buffer_head *bh; |
941 | journal_superblock_t *sb; | |
942 | int i, err; | |
943 | ||
944 | if (journal->j_maxlen < JFS_MIN_JOURNAL_BLOCKS) { | |
945 | printk (KERN_ERR "Journal length (%d blocks) too short.\n", | |
946 | journal->j_maxlen); | |
947 | journal_fail_superblock(journal); | |
948 | return -EINVAL; | |
949 | } | |
950 | ||
951 | if (journal->j_inode == NULL) { | |
952 | /* | |
953 | * We don't know what block to start at! | |
954 | */ | |
955 | printk(KERN_EMERG | |
956 | "%s: creation of journal on external device!\n", | |
08fc99bf | 957 | __func__); |
1da177e4 LT |
958 | BUG(); |
959 | } | |
960 | ||
961 | /* Zero out the entire journal on disk. We cannot afford to | |
962 | have any blocks on disk beginning with JFS_MAGIC_NUMBER. */ | |
963 | jbd_debug(1, "JBD: Zeroing out journal blocks...\n"); | |
964 | for (i = 0; i < journal->j_maxlen; i++) { | |
965 | err = journal_bmap(journal, i, &blocknr); | |
966 | if (err) | |
967 | return err; | |
968 | bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); | |
2a0e3388 NK |
969 | if (unlikely(!bh)) |
970 | return -ENOMEM; | |
1da177e4 LT |
971 | lock_buffer(bh); |
972 | memset (bh->b_data, 0, journal->j_blocksize); | |
973 | BUFFER_TRACE(bh, "marking dirty"); | |
974 | mark_buffer_dirty(bh); | |
975 | BUFFER_TRACE(bh, "marking uptodate"); | |
976 | set_buffer_uptodate(bh); | |
977 | unlock_buffer(bh); | |
978 | __brelse(bh); | |
979 | } | |
980 | ||
981 | sync_blockdev(journal->j_dev); | |
982 | jbd_debug(1, "JBD: journal cleared.\n"); | |
983 | ||
984 | /* OK, fill in the initial static fields in the new superblock */ | |
985 | sb = journal->j_superblock; | |
986 | ||
987 | sb->s_header.h_magic = cpu_to_be32(JFS_MAGIC_NUMBER); | |
988 | sb->s_header.h_blocktype = cpu_to_be32(JFS_SUPERBLOCK_V2); | |
989 | ||
990 | sb->s_blocksize = cpu_to_be32(journal->j_blocksize); | |
991 | sb->s_maxlen = cpu_to_be32(journal->j_maxlen); | |
992 | sb->s_first = cpu_to_be32(1); | |
993 | ||
994 | journal->j_transaction_sequence = 1; | |
995 | ||
996 | journal->j_flags &= ~JFS_ABORT; | |
997 | journal->j_format_version = 2; | |
998 | ||
999 | return journal_reset(journal); | |
1000 | } | |
1001 | ||
ae6ddcc5 | 1002 | /** |
1da177e4 LT |
1003 | * void journal_update_superblock() - Update journal sb on disk. |
1004 | * @journal: The journal to update. | |
1005 | * @wait: Set to '0' if you don't want to wait for IO completion. | |
1006 | * | |
1007 | * Update a journal's dynamic superblock fields and write it to disk, | |
1008 | * optionally waiting for the IO to complete. | |
1009 | */ | |
1010 | void journal_update_superblock(journal_t *journal, int wait) | |
1011 | { | |
1012 | journal_superblock_t *sb = journal->j_superblock; | |
1013 | struct buffer_head *bh = journal->j_sb_buffer; | |
1014 | ||
1015 | /* | |
1016 | * As a special case, if the on-disk copy is already marked as needing | |
1017 | * no recovery (s_start == 0) and there are no outstanding transactions | |
1018 | * in the filesystem, then we can safely defer the superblock update | |
1019 | * until the next commit by setting JFS_FLUSHED. This avoids | |
1020 | * attempting a write to a potential-readonly device. | |
1021 | */ | |
1022 | if (sb->s_start == 0 && journal->j_tail_sequence == | |
1023 | journal->j_transaction_sequence) { | |
1024 | jbd_debug(1,"JBD: Skipping superblock update on recovered sb " | |
9c28cbcc | 1025 | "(start %u, seq %d, errno %d)\n", |
ae6ddcc5 | 1026 | journal->j_tail, journal->j_tail_sequence, |
1da177e4 LT |
1027 | journal->j_errno); |
1028 | goto out; | |
1029 | } | |
1030 | ||
dff6825e DW |
1031 | if (buffer_write_io_error(bh)) { |
1032 | char b[BDEVNAME_SIZE]; | |
1033 | /* | |
1034 | * Oh, dear. A previous attempt to write the journal | |
1035 | * superblock failed. This could happen because the | |
1036 | * USB device was yanked out. Or it could happen to | |
1037 | * be a transient write error and maybe the block will | |
1038 | * be remapped. Nothing we can do but to retry the | |
1039 | * write and hope for the best. | |
1040 | */ | |
1041 | printk(KERN_ERR "JBD: previous I/O error detected " | |
1042 | "for journal superblock update for %s.\n", | |
1043 | journal_dev_name(journal, b)); | |
1044 | clear_buffer_write_io_error(bh); | |
1045 | set_buffer_uptodate(bh); | |
1046 | } | |
1047 | ||
1da177e4 | 1048 | spin_lock(&journal->j_state_lock); |
9c28cbcc | 1049 | jbd_debug(1,"JBD: updating superblock (start %u, seq %d, errno %d)\n", |
1da177e4 LT |
1050 | journal->j_tail, journal->j_tail_sequence, journal->j_errno); |
1051 | ||
1052 | sb->s_sequence = cpu_to_be32(journal->j_tail_sequence); | |
1053 | sb->s_start = cpu_to_be32(journal->j_tail); | |
1054 | sb->s_errno = cpu_to_be32(journal->j_errno); | |
1055 | spin_unlock(&journal->j_state_lock); | |
1056 | ||
1057 | BUFFER_TRACE(bh, "marking dirty"); | |
1058 | mark_buffer_dirty(bh); | |
dff6825e | 1059 | if (wait) { |
1da177e4 | 1060 | sync_dirty_buffer(bh); |
dff6825e DW |
1061 | if (buffer_write_io_error(bh)) { |
1062 | char b[BDEVNAME_SIZE]; | |
1063 | printk(KERN_ERR "JBD: I/O error detected " | |
1064 | "when updating journal superblock for %s.\n", | |
1065 | journal_dev_name(journal, b)); | |
1066 | clear_buffer_write_io_error(bh); | |
1067 | set_buffer_uptodate(bh); | |
1068 | } | |
1069 | } else | |
9cb569d6 | 1070 | write_dirty_buffer(bh, WRITE); |
1da177e4 | 1071 | |
99cb1a31 | 1072 | trace_jbd_update_superblock_end(journal, wait); |
1da177e4 LT |
1073 | out: |
1074 | /* If we have just flushed the log (by marking s_start==0), then | |
1075 | * any future commit will have to be careful to update the | |
1076 | * superblock again to re-record the true start of the log. */ | |
1077 | ||
1078 | spin_lock(&journal->j_state_lock); | |
1079 | if (sb->s_start) | |
1080 | journal->j_flags &= ~JFS_FLUSHED; | |
1081 | else | |
1082 | journal->j_flags |= JFS_FLUSHED; | |
1083 | spin_unlock(&journal->j_state_lock); | |
1084 | } | |
1085 | ||
1086 | /* | |
1087 | * Read the superblock for a given journal, performing initial | |
1088 | * validation of the format. | |
1089 | */ | |
1090 | ||
1091 | static int journal_get_superblock(journal_t *journal) | |
1092 | { | |
1093 | struct buffer_head *bh; | |
1094 | journal_superblock_t *sb; | |
1095 | int err = -EIO; | |
1096 | ||
1097 | bh = journal->j_sb_buffer; | |
1098 | ||
1099 | J_ASSERT(bh != NULL); | |
1100 | if (!buffer_uptodate(bh)) { | |
1101 | ll_rw_block(READ, 1, &bh); | |
1102 | wait_on_buffer(bh); | |
1103 | if (!buffer_uptodate(bh)) { | |
1104 | printk (KERN_ERR | |
1105 | "JBD: IO error reading journal superblock\n"); | |
1106 | goto out; | |
1107 | } | |
1108 | } | |
1109 | ||
1110 | sb = journal->j_superblock; | |
1111 | ||
1112 | err = -EINVAL; | |
1113 | ||
1114 | if (sb->s_header.h_magic != cpu_to_be32(JFS_MAGIC_NUMBER) || | |
1115 | sb->s_blocksize != cpu_to_be32(journal->j_blocksize)) { | |
1116 | printk(KERN_WARNING "JBD: no valid journal superblock found\n"); | |
1117 | goto out; | |
1118 | } | |
1119 | ||
1120 | switch(be32_to_cpu(sb->s_header.h_blocktype)) { | |
1121 | case JFS_SUPERBLOCK_V1: | |
1122 | journal->j_format_version = 1; | |
1123 | break; | |
1124 | case JFS_SUPERBLOCK_V2: | |
1125 | journal->j_format_version = 2; | |
1126 | break; | |
1127 | default: | |
1128 | printk(KERN_WARNING "JBD: unrecognised superblock format ID\n"); | |
1129 | goto out; | |
1130 | } | |
1131 | ||
1132 | if (be32_to_cpu(sb->s_maxlen) < journal->j_maxlen) | |
1133 | journal->j_maxlen = be32_to_cpu(sb->s_maxlen); | |
1134 | else if (be32_to_cpu(sb->s_maxlen) > journal->j_maxlen) { | |
1135 | printk (KERN_WARNING "JBD: journal file too short\n"); | |
1136 | goto out; | |
1137 | } | |
1138 | ||
8762202d EG |
1139 | if (be32_to_cpu(sb->s_first) == 0 || |
1140 | be32_to_cpu(sb->s_first) >= journal->j_maxlen) { | |
1141 | printk(KERN_WARNING | |
1142 | "JBD: Invalid start block of journal: %u\n", | |
1143 | be32_to_cpu(sb->s_first)); | |
1144 | goto out; | |
1145 | } | |
1146 | ||
1da177e4 LT |
1147 | return 0; |
1148 | ||
1149 | out: | |
1150 | journal_fail_superblock(journal); | |
1151 | return err; | |
1152 | } | |
1153 | ||
1154 | /* | |
1155 | * Load the on-disk journal superblock and read the key fields into the | |
1156 | * journal_t. | |
1157 | */ | |
1158 | ||
1159 | static int load_superblock(journal_t *journal) | |
1160 | { | |
1161 | int err; | |
1162 | journal_superblock_t *sb; | |
1163 | ||
1164 | err = journal_get_superblock(journal); | |
1165 | if (err) | |
1166 | return err; | |
1167 | ||
1168 | sb = journal->j_superblock; | |
1169 | ||
1170 | journal->j_tail_sequence = be32_to_cpu(sb->s_sequence); | |
1171 | journal->j_tail = be32_to_cpu(sb->s_start); | |
1172 | journal->j_first = be32_to_cpu(sb->s_first); | |
1173 | journal->j_last = be32_to_cpu(sb->s_maxlen); | |
1174 | journal->j_errno = be32_to_cpu(sb->s_errno); | |
1175 | ||
1176 | return 0; | |
1177 | } | |
1178 | ||
1179 | ||
1180 | /** | |
1181 | * int journal_load() - Read journal from disk. | |
1182 | * @journal: Journal to act on. | |
ae6ddcc5 | 1183 | * |
1da177e4 LT |
1184 | * Given a journal_t structure which tells us which disk blocks contain |
1185 | * a journal, read the journal from disk to initialise the in-memory | |
1186 | * structures. | |
1187 | */ | |
1188 | int journal_load(journal_t *journal) | |
1189 | { | |
1190 | int err; | |
ea817398 | 1191 | journal_superblock_t *sb; |
1da177e4 LT |
1192 | |
1193 | err = load_superblock(journal); | |
1194 | if (err) | |
1195 | return err; | |
1196 | ||
ea817398 | 1197 | sb = journal->j_superblock; |
1da177e4 LT |
1198 | /* If this is a V2 superblock, then we have to check the |
1199 | * features flags on it. */ | |
1200 | ||
1201 | if (journal->j_format_version >= 2) { | |
1da177e4 LT |
1202 | if ((sb->s_feature_ro_compat & |
1203 | ~cpu_to_be32(JFS_KNOWN_ROCOMPAT_FEATURES)) || | |
1204 | (sb->s_feature_incompat & | |
1205 | ~cpu_to_be32(JFS_KNOWN_INCOMPAT_FEATURES))) { | |
1206 | printk (KERN_WARNING | |
1207 | "JBD: Unrecognised features on journal\n"); | |
1208 | return -EINVAL; | |
1209 | } | |
1210 | } | |
1211 | ||
1212 | /* Let the recovery code check whether it needs to recover any | |
1213 | * data from the journal. */ | |
1214 | if (journal_recover(journal)) | |
1215 | goto recovery_error; | |
1216 | ||
1217 | /* OK, we've finished with the dynamic journal bits: | |
1218 | * reinitialise the dynamic contents of the superblock in memory | |
1219 | * and reset them on disk. */ | |
1220 | if (journal_reset(journal)) | |
1221 | goto recovery_error; | |
1222 | ||
1223 | journal->j_flags &= ~JFS_ABORT; | |
1224 | journal->j_flags |= JFS_LOADED; | |
1225 | return 0; | |
1226 | ||
1227 | recovery_error: | |
1228 | printk (KERN_WARNING "JBD: recovery failed\n"); | |
1229 | return -EIO; | |
1230 | } | |
1231 | ||
1232 | /** | |
1233 | * void journal_destroy() - Release a journal_t structure. | |
1234 | * @journal: Journal to act on. | |
1235 | * | |
1236 | * Release a journal_t structure once it is no longer in use by the | |
1237 | * journaled object. | |
4afe9785 | 1238 | * Return <0 if we couldn't clean up the journal. |
1da177e4 | 1239 | */ |
4afe9785 | 1240 | int journal_destroy(journal_t *journal) |
1da177e4 | 1241 | { |
4afe9785 HK |
1242 | int err = 0; |
1243 | ||
03f4d804 | 1244 | |
1da177e4 LT |
1245 | /* Wait for the commit thread to wake up and die. */ |
1246 | journal_kill_thread(journal); | |
1247 | ||
1248 | /* Force a final log commit */ | |
1249 | if (journal->j_running_transaction) | |
1250 | journal_commit_transaction(journal); | |
1251 | ||
1252 | /* Force any old transactions to disk */ | |
1253 | ||
1254 | /* Totally anal locking here... */ | |
1255 | spin_lock(&journal->j_list_lock); | |
1256 | while (journal->j_checkpoint_transactions != NULL) { | |
1257 | spin_unlock(&journal->j_list_lock); | |
1258 | log_do_checkpoint(journal); | |
1259 | spin_lock(&journal->j_list_lock); | |
1260 | } | |
1261 | ||
1262 | J_ASSERT(journal->j_running_transaction == NULL); | |
1263 | J_ASSERT(journal->j_committing_transaction == NULL); | |
1264 | J_ASSERT(journal->j_checkpoint_transactions == NULL); | |
1265 | spin_unlock(&journal->j_list_lock); | |
1266 | ||
1da177e4 | 1267 | if (journal->j_sb_buffer) { |
4afe9785 HK |
1268 | if (!is_journal_aborted(journal)) { |
1269 | /* We can now mark the journal as empty. */ | |
1270 | journal->j_tail = 0; | |
1271 | journal->j_tail_sequence = | |
1272 | ++journal->j_transaction_sequence; | |
1273 | journal_update_superblock(journal, 1); | |
1274 | } else { | |
1275 | err = -EIO; | |
1276 | } | |
1da177e4 LT |
1277 | brelse(journal->j_sb_buffer); |
1278 | } | |
1279 | ||
1280 | if (journal->j_inode) | |
1281 | iput(journal->j_inode); | |
1282 | if (journal->j_revoke) | |
1283 | journal_destroy_revoke(journal); | |
1284 | kfree(journal->j_wbuf); | |
1285 | kfree(journal); | |
4afe9785 HK |
1286 | |
1287 | return err; | |
1da177e4 LT |
1288 | } |
1289 | ||
1290 | ||
1291 | /** | |
1292 | *int journal_check_used_features () - Check if features specified are used. | |
1293 | * @journal: Journal to check. | |
1294 | * @compat: bitmask of compatible features | |
1295 | * @ro: bitmask of features that force read-only mount | |
1296 | * @incompat: bitmask of incompatible features | |
ae6ddcc5 | 1297 | * |
1da177e4 | 1298 | * Check whether the journal uses all of a given set of |
ae6ddcc5 | 1299 | * features. Return true (non-zero) if it does. |
1da177e4 LT |
1300 | **/ |
1301 | ||
1302 | int journal_check_used_features (journal_t *journal, unsigned long compat, | |
1303 | unsigned long ro, unsigned long incompat) | |
1304 | { | |
1305 | journal_superblock_t *sb; | |
1306 | ||
1307 | if (!compat && !ro && !incompat) | |
1308 | return 1; | |
1309 | if (journal->j_format_version == 1) | |
1310 | return 0; | |
1311 | ||
1312 | sb = journal->j_superblock; | |
1313 | ||
1314 | if (((be32_to_cpu(sb->s_feature_compat) & compat) == compat) && | |
1315 | ((be32_to_cpu(sb->s_feature_ro_compat) & ro) == ro) && | |
1316 | ((be32_to_cpu(sb->s_feature_incompat) & incompat) == incompat)) | |
1317 | return 1; | |
1318 | ||
1319 | return 0; | |
1320 | } | |
1321 | ||
1322 | /** | |
1323 | * int journal_check_available_features() - Check feature set in journalling layer | |
1324 | * @journal: Journal to check. | |
1325 | * @compat: bitmask of compatible features | |
1326 | * @ro: bitmask of features that force read-only mount | |
1327 | * @incompat: bitmask of incompatible features | |
ae6ddcc5 | 1328 | * |
1da177e4 LT |
1329 | * Check whether the journaling code supports the use of |
1330 | * all of a given set of features on this journal. Return true | |
1331 | * (non-zero) if it can. */ | |
1332 | ||
1333 | int journal_check_available_features (journal_t *journal, unsigned long compat, | |
1334 | unsigned long ro, unsigned long incompat) | |
1335 | { | |
1da177e4 LT |
1336 | if (!compat && !ro && !incompat) |
1337 | return 1; | |
1338 | ||
1da177e4 LT |
1339 | /* We can support any known requested features iff the |
1340 | * superblock is in version 2. Otherwise we fail to support any | |
1341 | * extended sb features. */ | |
1342 | ||
1343 | if (journal->j_format_version != 2) | |
1344 | return 0; | |
1345 | ||
1346 | if ((compat & JFS_KNOWN_COMPAT_FEATURES) == compat && | |
1347 | (ro & JFS_KNOWN_ROCOMPAT_FEATURES) == ro && | |
1348 | (incompat & JFS_KNOWN_INCOMPAT_FEATURES) == incompat) | |
1349 | return 1; | |
1350 | ||
1351 | return 0; | |
1352 | } | |
1353 | ||
1354 | /** | |
1355 | * int journal_set_features () - Mark a given journal feature in the superblock | |
1356 | * @journal: Journal to act on. | |
1357 | * @compat: bitmask of compatible features | |
1358 | * @ro: bitmask of features that force read-only mount | |
1359 | * @incompat: bitmask of incompatible features | |
1360 | * | |
1361 | * Mark a given journal feature as present on the | |
ae6ddcc5 | 1362 | * superblock. Returns true if the requested features could be set. |
1da177e4 LT |
1363 | * |
1364 | */ | |
1365 | ||
1366 | int journal_set_features (journal_t *journal, unsigned long compat, | |
1367 | unsigned long ro, unsigned long incompat) | |
1368 | { | |
1369 | journal_superblock_t *sb; | |
1370 | ||
1371 | if (journal_check_used_features(journal, compat, ro, incompat)) | |
1372 | return 1; | |
1373 | ||
1374 | if (!journal_check_available_features(journal, compat, ro, incompat)) | |
1375 | return 0; | |
1376 | ||
1377 | jbd_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n", | |
1378 | compat, ro, incompat); | |
1379 | ||
1380 | sb = journal->j_superblock; | |
1381 | ||
1382 | sb->s_feature_compat |= cpu_to_be32(compat); | |
1383 | sb->s_feature_ro_compat |= cpu_to_be32(ro); | |
1384 | sb->s_feature_incompat |= cpu_to_be32(incompat); | |
1385 | ||
1386 | return 1; | |
1387 | } | |
1388 | ||
1389 | ||
1390 | /** | |
1391 | * int journal_update_format () - Update on-disk journal structure. | |
1392 | * @journal: Journal to act on. | |
1393 | * | |
1394 | * Given an initialised but unloaded journal struct, poke about in the | |
1395 | * on-disk structure to update it to the most recent supported version. | |
1396 | */ | |
1397 | int journal_update_format (journal_t *journal) | |
1398 | { | |
1399 | journal_superblock_t *sb; | |
1400 | int err; | |
1401 | ||
1402 | err = journal_get_superblock(journal); | |
1403 | if (err) | |
1404 | return err; | |
1405 | ||
1406 | sb = journal->j_superblock; | |
1407 | ||
1408 | switch (be32_to_cpu(sb->s_header.h_blocktype)) { | |
1409 | case JFS_SUPERBLOCK_V2: | |
1410 | return 0; | |
1411 | case JFS_SUPERBLOCK_V1: | |
1412 | return journal_convert_superblock_v1(journal, sb); | |
1413 | default: | |
1414 | break; | |
1415 | } | |
1416 | return -EINVAL; | |
1417 | } | |
1418 | ||
1419 | static int journal_convert_superblock_v1(journal_t *journal, | |
1420 | journal_superblock_t *sb) | |
1421 | { | |
1422 | int offset, blocksize; | |
1423 | struct buffer_head *bh; | |
1424 | ||
1425 | printk(KERN_WARNING | |
1426 | "JBD: Converting superblock from version 1 to 2.\n"); | |
1427 | ||
1428 | /* Pre-initialise new fields to zero */ | |
1429 | offset = ((char *) &(sb->s_feature_compat)) - ((char *) sb); | |
1430 | blocksize = be32_to_cpu(sb->s_blocksize); | |
1431 | memset(&sb->s_feature_compat, 0, blocksize-offset); | |
1432 | ||
1433 | sb->s_nr_users = cpu_to_be32(1); | |
1434 | sb->s_header.h_blocktype = cpu_to_be32(JFS_SUPERBLOCK_V2); | |
1435 | journal->j_format_version = 2; | |
1436 | ||
1437 | bh = journal->j_sb_buffer; | |
1438 | BUFFER_TRACE(bh, "marking dirty"); | |
1439 | mark_buffer_dirty(bh); | |
1440 | sync_dirty_buffer(bh); | |
1441 | return 0; | |
1442 | } | |
1443 | ||
1444 | ||
1445 | /** | |
1446 | * int journal_flush () - Flush journal | |
1447 | * @journal: Journal to act on. | |
ae6ddcc5 | 1448 | * |
1da177e4 LT |
1449 | * Flush all data for a given journal to disk and empty the journal. |
1450 | * Filesystems can use this when remounting readonly to ensure that | |
1451 | * recovery does not need to happen on remount. | |
1452 | */ | |
1453 | ||
1454 | int journal_flush(journal_t *journal) | |
1455 | { | |
1456 | int err = 0; | |
1457 | transaction_t *transaction = NULL; | |
9c28cbcc | 1458 | unsigned int old_tail; |
1da177e4 LT |
1459 | |
1460 | spin_lock(&journal->j_state_lock); | |
1461 | ||
1462 | /* Force everything buffered to the log... */ | |
1463 | if (journal->j_running_transaction) { | |
1464 | transaction = journal->j_running_transaction; | |
1465 | __log_start_commit(journal, transaction->t_tid); | |
1466 | } else if (journal->j_committing_transaction) | |
1467 | transaction = journal->j_committing_transaction; | |
1468 | ||
1469 | /* Wait for the log commit to complete... */ | |
1470 | if (transaction) { | |
1471 | tid_t tid = transaction->t_tid; | |
1472 | ||
1473 | spin_unlock(&journal->j_state_lock); | |
1474 | log_wait_commit(journal, tid); | |
1475 | } else { | |
1476 | spin_unlock(&journal->j_state_lock); | |
1477 | } | |
1478 | ||
1479 | /* ...and flush everything in the log out to disk. */ | |
1480 | spin_lock(&journal->j_list_lock); | |
1481 | while (!err && journal->j_checkpoint_transactions != NULL) { | |
1482 | spin_unlock(&journal->j_list_lock); | |
4afe9785 | 1483 | mutex_lock(&journal->j_checkpoint_mutex); |
1da177e4 | 1484 | err = log_do_checkpoint(journal); |
4afe9785 | 1485 | mutex_unlock(&journal->j_checkpoint_mutex); |
1da177e4 LT |
1486 | spin_lock(&journal->j_list_lock); |
1487 | } | |
1488 | spin_unlock(&journal->j_list_lock); | |
4afe9785 HK |
1489 | |
1490 | if (is_journal_aborted(journal)) | |
1491 | return -EIO; | |
1492 | ||
1da177e4 LT |
1493 | cleanup_journal_tail(journal); |
1494 | ||
1495 | /* Finally, mark the journal as really needing no recovery. | |
1496 | * This sets s_start==0 in the underlying superblock, which is | |
1497 | * the magic code for a fully-recovered superblock. Any future | |
1498 | * commits of data to the journal will restore the current | |
1499 | * s_start value. */ | |
1500 | spin_lock(&journal->j_state_lock); | |
1501 | old_tail = journal->j_tail; | |
1502 | journal->j_tail = 0; | |
1503 | spin_unlock(&journal->j_state_lock); | |
1504 | journal_update_superblock(journal, 1); | |
1505 | spin_lock(&journal->j_state_lock); | |
1506 | journal->j_tail = old_tail; | |
1507 | ||
1508 | J_ASSERT(!journal->j_running_transaction); | |
1509 | J_ASSERT(!journal->j_committing_transaction); | |
1510 | J_ASSERT(!journal->j_checkpoint_transactions); | |
1511 | J_ASSERT(journal->j_head == journal->j_tail); | |
1512 | J_ASSERT(journal->j_tail_sequence == journal->j_transaction_sequence); | |
1513 | spin_unlock(&journal->j_state_lock); | |
4afe9785 | 1514 | return 0; |
1da177e4 LT |
1515 | } |
1516 | ||
1517 | /** | |
1518 | * int journal_wipe() - Wipe journal contents | |
1519 | * @journal: Journal to act on. | |
1520 | * @write: flag (see below) | |
ae6ddcc5 | 1521 | * |
1da177e4 LT |
1522 | * Wipe out all of the contents of a journal, safely. This will produce |
1523 | * a warning if the journal contains any valid recovery information. | |
1524 | * Must be called between journal_init_*() and journal_load(). | |
1525 | * | |
1526 | * If 'write' is non-zero, then we wipe out the journal on disk; otherwise | |
1527 | * we merely suppress recovery. | |
1528 | */ | |
1529 | ||
1530 | int journal_wipe(journal_t *journal, int write) | |
1531 | { | |
1da177e4 LT |
1532 | int err = 0; |
1533 | ||
1534 | J_ASSERT (!(journal->j_flags & JFS_LOADED)); | |
1535 | ||
1536 | err = load_superblock(journal); | |
1537 | if (err) | |
1538 | return err; | |
1539 | ||
1da177e4 LT |
1540 | if (!journal->j_tail) |
1541 | goto no_recovery; | |
1542 | ||
1543 | printk (KERN_WARNING "JBD: %s recovery information on journal\n", | |
1544 | write ? "Clearing" : "Ignoring"); | |
1545 | ||
1546 | err = journal_skip_recovery(journal); | |
1547 | if (write) | |
1548 | journal_update_superblock(journal, 1); | |
1549 | ||
1550 | no_recovery: | |
1551 | return err; | |
1552 | } | |
1553 | ||
1554 | /* | |
1555 | * journal_dev_name: format a character string to describe on what | |
1556 | * device this journal is present. | |
1557 | */ | |
1558 | ||
022a4a7b | 1559 | static const char *journal_dev_name(journal_t *journal, char *buffer) |
1da177e4 LT |
1560 | { |
1561 | struct block_device *bdev; | |
1562 | ||
1563 | if (journal->j_inode) | |
1564 | bdev = journal->j_inode->i_sb->s_bdev; | |
1565 | else | |
1566 | bdev = journal->j_dev; | |
1567 | ||
1568 | return bdevname(bdev, buffer); | |
1569 | } | |
1570 | ||
1571 | /* | |
1572 | * Journal abort has very specific semantics, which we describe | |
ae6ddcc5 | 1573 | * for journal abort. |
1da177e4 LT |
1574 | * |
1575 | * Two internal function, which provide abort to te jbd layer | |
1576 | * itself are here. | |
1577 | */ | |
1578 | ||
1579 | /* | |
1580 | * Quick version for internal journal use (doesn't lock the journal). | |
1581 | * Aborts hard --- we mark the abort as occurred, but do _nothing_ else, | |
1582 | * and don't attempt to make any other journal updates. | |
1583 | */ | |
53308383 | 1584 | static void __journal_abort_hard(journal_t *journal) |
1da177e4 LT |
1585 | { |
1586 | transaction_t *transaction; | |
1587 | char b[BDEVNAME_SIZE]; | |
1588 | ||
1589 | if (journal->j_flags & JFS_ABORT) | |
1590 | return; | |
1591 | ||
1592 | printk(KERN_ERR "Aborting journal on device %s.\n", | |
1593 | journal_dev_name(journal, b)); | |
1594 | ||
1595 | spin_lock(&journal->j_state_lock); | |
1596 | journal->j_flags |= JFS_ABORT; | |
1597 | transaction = journal->j_running_transaction; | |
1598 | if (transaction) | |
1599 | __log_start_commit(journal, transaction->t_tid); | |
1600 | spin_unlock(&journal->j_state_lock); | |
1601 | } | |
1602 | ||
1603 | /* Soft abort: record the abort error status in the journal superblock, | |
1604 | * but don't do any other IO. */ | |
022a4a7b | 1605 | static void __journal_abort_soft (journal_t *journal, int errno) |
1da177e4 LT |
1606 | { |
1607 | if (journal->j_flags & JFS_ABORT) | |
1608 | return; | |
1609 | ||
1610 | if (!journal->j_errno) | |
1611 | journal->j_errno = errno; | |
1612 | ||
1613 | __journal_abort_hard(journal); | |
1614 | ||
1615 | if (errno) | |
1616 | journal_update_superblock(journal, 1); | |
1617 | } | |
1618 | ||
1619 | /** | |
1620 | * void journal_abort () - Shutdown the journal immediately. | |
1621 | * @journal: the journal to shutdown. | |
1622 | * @errno: an error number to record in the journal indicating | |
1623 | * the reason for the shutdown. | |
1624 | * | |
1625 | * Perform a complete, immediate shutdown of the ENTIRE | |
1626 | * journal (not of a single transaction). This operation cannot be | |
1627 | * undone without closing and reopening the journal. | |
ae6ddcc5 | 1628 | * |
1da177e4 LT |
1629 | * The journal_abort function is intended to support higher level error |
1630 | * recovery mechanisms such as the ext2/ext3 remount-readonly error | |
1631 | * mode. | |
1632 | * | |
1633 | * Journal abort has very specific semantics. Any existing dirty, | |
1634 | * unjournaled buffers in the main filesystem will still be written to | |
1635 | * disk by bdflush, but the journaling mechanism will be suspended | |
1636 | * immediately and no further transaction commits will be honoured. | |
1637 | * | |
1638 | * Any dirty, journaled buffers will be written back to disk without | |
1639 | * hitting the journal. Atomicity cannot be guaranteed on an aborted | |
1640 | * filesystem, but we _do_ attempt to leave as much data as possible | |
1641 | * behind for fsck to use for cleanup. | |
1642 | * | |
1643 | * Any attempt to get a new transaction handle on a journal which is in | |
1644 | * ABORT state will just result in an -EROFS error return. A | |
1645 | * journal_stop on an existing handle will return -EIO if we have | |
1646 | * entered abort state during the update. | |
1647 | * | |
1648 | * Recursive transactions are not disturbed by journal abort until the | |
1649 | * final journal_stop, which will receive the -EIO error. | |
1650 | * | |
1651 | * Finally, the journal_abort call allows the caller to supply an errno | |
1652 | * which will be recorded (if possible) in the journal superblock. This | |
1653 | * allows a client to record failure conditions in the middle of a | |
1654 | * transaction without having to complete the transaction to record the | |
1655 | * failure to disk. ext3_error, for example, now uses this | |
1656 | * functionality. | |
1657 | * | |
1658 | * Errors which originate from within the journaling layer will NOT | |
1659 | * supply an errno; a null errno implies that absolutely no further | |
1660 | * writes are done to the journal (unless there are any already in | |
1661 | * progress). | |
ae6ddcc5 | 1662 | * |
1da177e4 LT |
1663 | */ |
1664 | ||
1665 | void journal_abort(journal_t *journal, int errno) | |
1666 | { | |
1667 | __journal_abort_soft(journal, errno); | |
1668 | } | |
1669 | ||
ae6ddcc5 | 1670 | /** |
1da177e4 LT |
1671 | * int journal_errno () - returns the journal's error state. |
1672 | * @journal: journal to examine. | |
1673 | * | |
1674 | * This is the errno numbet set with journal_abort(), the last | |
1675 | * time the journal was mounted - if the journal was stopped | |
1676 | * without calling abort this will be 0. | |
1677 | * | |
1678 | * If the journal has been aborted on this mount time -EROFS will | |
1679 | * be returned. | |
1680 | */ | |
1681 | int journal_errno(journal_t *journal) | |
1682 | { | |
1683 | int err; | |
1684 | ||
1685 | spin_lock(&journal->j_state_lock); | |
1686 | if (journal->j_flags & JFS_ABORT) | |
1687 | err = -EROFS; | |
1688 | else | |
1689 | err = journal->j_errno; | |
1690 | spin_unlock(&journal->j_state_lock); | |
1691 | return err; | |
1692 | } | |
1693 | ||
ae6ddcc5 | 1694 | /** |
1da177e4 LT |
1695 | * int journal_clear_err () - clears the journal's error state |
1696 | * @journal: journal to act on. | |
1697 | * | |
1698 | * An error must be cleared or Acked to take a FS out of readonly | |
1699 | * mode. | |
1700 | */ | |
1701 | int journal_clear_err(journal_t *journal) | |
1702 | { | |
1703 | int err = 0; | |
1704 | ||
1705 | spin_lock(&journal->j_state_lock); | |
1706 | if (journal->j_flags & JFS_ABORT) | |
1707 | err = -EROFS; | |
1708 | else | |
1709 | journal->j_errno = 0; | |
1710 | spin_unlock(&journal->j_state_lock); | |
1711 | return err; | |
1712 | } | |
1713 | ||
ae6ddcc5 | 1714 | /** |
1da177e4 LT |
1715 | * void journal_ack_err() - Ack journal err. |
1716 | * @journal: journal to act on. | |
1717 | * | |
1718 | * An error must be cleared or Acked to take a FS out of readonly | |
1719 | * mode. | |
1720 | */ | |
1721 | void journal_ack_err(journal_t *journal) | |
1722 | { | |
1723 | spin_lock(&journal->j_state_lock); | |
1724 | if (journal->j_errno) | |
1725 | journal->j_flags |= JFS_ACK_ERR; | |
1726 | spin_unlock(&journal->j_state_lock); | |
1727 | } | |
1728 | ||
1729 | int journal_blocks_per_page(struct inode *inode) | |
1730 | { | |
1731 | return 1 << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits); | |
1732 | } | |
1733 | ||
1da177e4 LT |
1734 | /* |
1735 | * Journal_head storage management | |
1736 | */ | |
e18b890b | 1737 | static struct kmem_cache *journal_head_cache; |
1da177e4 LT |
1738 | #ifdef CONFIG_JBD_DEBUG |
1739 | static atomic_t nr_journal_heads = ATOMIC_INIT(0); | |
1740 | #endif | |
1741 | ||
1742 | static int journal_init_journal_head_cache(void) | |
1743 | { | |
1744 | int retval; | |
1745 | ||
1076d17a | 1746 | J_ASSERT(journal_head_cache == NULL); |
1da177e4 LT |
1747 | journal_head_cache = kmem_cache_create("journal_head", |
1748 | sizeof(struct journal_head), | |
1749 | 0, /* offset */ | |
e12ba74d | 1750 | SLAB_TEMPORARY, /* flags */ |
20c2df83 | 1751 | NULL); /* ctor */ |
1da177e4 | 1752 | retval = 0; |
1076d17a | 1753 | if (!journal_head_cache) { |
1da177e4 LT |
1754 | retval = -ENOMEM; |
1755 | printk(KERN_EMERG "JBD: no memory for journal_head cache\n"); | |
1756 | } | |
1757 | return retval; | |
1758 | } | |
1759 | ||
1760 | static void journal_destroy_journal_head_cache(void) | |
1761 | { | |
3850f7a5 DG |
1762 | if (journal_head_cache) { |
1763 | kmem_cache_destroy(journal_head_cache); | |
1764 | journal_head_cache = NULL; | |
1765 | } | |
1da177e4 LT |
1766 | } |
1767 | ||
1768 | /* | |
1769 | * journal_head splicing and dicing | |
1770 | */ | |
1771 | static struct journal_head *journal_alloc_journal_head(void) | |
1772 | { | |
1773 | struct journal_head *ret; | |
1da177e4 LT |
1774 | |
1775 | #ifdef CONFIG_JBD_DEBUG | |
1776 | atomic_inc(&nr_journal_heads); | |
1777 | #endif | |
1778 | ret = kmem_cache_alloc(journal_head_cache, GFP_NOFS); | |
c80544dc | 1779 | if (ret == NULL) { |
1da177e4 | 1780 | jbd_debug(1, "out of memory for journal_head\n"); |
f81e3d45 NK |
1781 | printk_ratelimited(KERN_NOTICE "ENOMEM in %s, retrying.\n", |
1782 | __func__); | |
1783 | ||
c80544dc | 1784 | while (ret == NULL) { |
1da177e4 LT |
1785 | yield(); |
1786 | ret = kmem_cache_alloc(journal_head_cache, GFP_NOFS); | |
1787 | } | |
1788 | } | |
1789 | return ret; | |
1790 | } | |
1791 | ||
1792 | static void journal_free_journal_head(struct journal_head *jh) | |
1793 | { | |
1794 | #ifdef CONFIG_JBD_DEBUG | |
1795 | atomic_dec(&nr_journal_heads); | |
c9cf5528 | 1796 | memset(jh, JBD_POISON_FREE, sizeof(*jh)); |
1da177e4 LT |
1797 | #endif |
1798 | kmem_cache_free(journal_head_cache, jh); | |
1799 | } | |
1800 | ||
1801 | /* | |
1802 | * A journal_head is attached to a buffer_head whenever JBD has an | |
1803 | * interest in the buffer. | |
1804 | * | |
1805 | * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit | |
1806 | * is set. This bit is tested in core kernel code where we need to take | |
1807 | * JBD-specific actions. Testing the zeroness of ->b_private is not reliable | |
1808 | * there. | |
1809 | * | |
1810 | * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one. | |
1811 | * | |
1812 | * When a buffer has its BH_JBD bit set it is immune from being released by | |
1813 | * core kernel code, mainly via ->b_count. | |
1814 | * | |
bb189247 JK |
1815 | * A journal_head is detached from its buffer_head when the journal_head's |
1816 | * b_jcount reaches zero. Running transaction (b_transaction) and checkpoint | |
1817 | * transaction (b_cp_transaction) hold their references to b_jcount. | |
1da177e4 LT |
1818 | * |
1819 | * Various places in the kernel want to attach a journal_head to a buffer_head | |
1820 | * _before_ attaching the journal_head to a transaction. To protect the | |
1821 | * journal_head in this situation, journal_add_journal_head elevates the | |
1822 | * journal_head's b_jcount refcount by one. The caller must call | |
1823 | * journal_put_journal_head() to undo this. | |
1824 | * | |
1825 | * So the typical usage would be: | |
1826 | * | |
1827 | * (Attach a journal_head if needed. Increments b_jcount) | |
1828 | * struct journal_head *jh = journal_add_journal_head(bh); | |
1829 | * ... | |
bb189247 JK |
1830 | * (Get another reference for transaction) |
1831 | * journal_grab_journal_head(bh); | |
1832 | * jh->b_transaction = xxx; | |
1833 | * (Put original reference) | |
1834 | * journal_put_journal_head(jh); | |
1da177e4 LT |
1835 | */ |
1836 | ||
1837 | /* | |
1838 | * Give a buffer_head a journal_head. | |
1839 | * | |
1da177e4 LT |
1840 | * May sleep. |
1841 | */ | |
1842 | struct journal_head *journal_add_journal_head(struct buffer_head *bh) | |
1843 | { | |
1844 | struct journal_head *jh; | |
1845 | struct journal_head *new_jh = NULL; | |
1846 | ||
1847 | repeat: | |
1848 | if (!buffer_jbd(bh)) { | |
1849 | new_jh = journal_alloc_journal_head(); | |
1850 | memset(new_jh, 0, sizeof(*new_jh)); | |
1851 | } | |
1852 | ||
1853 | jbd_lock_bh_journal_head(bh); | |
1854 | if (buffer_jbd(bh)) { | |
1855 | jh = bh2jh(bh); | |
1856 | } else { | |
1857 | J_ASSERT_BH(bh, | |
1858 | (atomic_read(&bh->b_count) > 0) || | |
1859 | (bh->b_page && bh->b_page->mapping)); | |
1860 | ||
1861 | if (!new_jh) { | |
1862 | jbd_unlock_bh_journal_head(bh); | |
1863 | goto repeat; | |
1864 | } | |
1865 | ||
1866 | jh = new_jh; | |
1867 | new_jh = NULL; /* We consumed it */ | |
1868 | set_buffer_jbd(bh); | |
1869 | bh->b_private = jh; | |
1870 | jh->b_bh = bh; | |
1871 | get_bh(bh); | |
1872 | BUFFER_TRACE(bh, "added journal_head"); | |
1873 | } | |
1874 | jh->b_jcount++; | |
1875 | jbd_unlock_bh_journal_head(bh); | |
1876 | if (new_jh) | |
1877 | journal_free_journal_head(new_jh); | |
1878 | return bh->b_private; | |
1879 | } | |
1880 | ||
1881 | /* | |
1882 | * Grab a ref against this buffer_head's journal_head. If it ended up not | |
1883 | * having a journal_head, return NULL | |
1884 | */ | |
1885 | struct journal_head *journal_grab_journal_head(struct buffer_head *bh) | |
1886 | { | |
1887 | struct journal_head *jh = NULL; | |
1888 | ||
1889 | jbd_lock_bh_journal_head(bh); | |
1890 | if (buffer_jbd(bh)) { | |
1891 | jh = bh2jh(bh); | |
1892 | jh->b_jcount++; | |
1893 | } | |
1894 | jbd_unlock_bh_journal_head(bh); | |
1895 | return jh; | |
1896 | } | |
1897 | ||
1898 | static void __journal_remove_journal_head(struct buffer_head *bh) | |
1899 | { | |
1900 | struct journal_head *jh = bh2jh(bh); | |
1901 | ||
1902 | J_ASSERT_JH(jh, jh->b_jcount >= 0); | |
bb189247 JK |
1903 | J_ASSERT_JH(jh, jh->b_transaction == NULL); |
1904 | J_ASSERT_JH(jh, jh->b_next_transaction == NULL); | |
1905 | J_ASSERT_JH(jh, jh->b_cp_transaction == NULL); | |
1906 | J_ASSERT_JH(jh, jh->b_jlist == BJ_None); | |
1907 | J_ASSERT_BH(bh, buffer_jbd(bh)); | |
1908 | J_ASSERT_BH(bh, jh2bh(jh) == bh); | |
1909 | BUFFER_TRACE(bh, "remove journal_head"); | |
1910 | if (jh->b_frozen_data) { | |
1911 | printk(KERN_WARNING "%s: freeing b_frozen_data\n", __func__); | |
1912 | jbd_free(jh->b_frozen_data, bh->b_size); | |
1da177e4 | 1913 | } |
bb189247 JK |
1914 | if (jh->b_committed_data) { |
1915 | printk(KERN_WARNING "%s: freeing b_committed_data\n", __func__); | |
1916 | jbd_free(jh->b_committed_data, bh->b_size); | |
1917 | } | |
1918 | bh->b_private = NULL; | |
1919 | jh->b_bh = NULL; /* debug, really */ | |
1920 | clear_buffer_jbd(bh); | |
1921 | journal_free_journal_head(jh); | |
1da177e4 LT |
1922 | } |
1923 | ||
1924 | /* | |
bb189247 | 1925 | * Drop a reference on the passed journal_head. If it fell to zero then |
1da177e4 LT |
1926 | * release the journal_head from the buffer_head. |
1927 | */ | |
1928 | void journal_put_journal_head(struct journal_head *jh) | |
1929 | { | |
1930 | struct buffer_head *bh = jh2bh(jh); | |
1931 | ||
1932 | jbd_lock_bh_journal_head(bh); | |
1933 | J_ASSERT_JH(jh, jh->b_jcount > 0); | |
1934 | --jh->b_jcount; | |
bb189247 | 1935 | if (!jh->b_jcount) { |
1da177e4 | 1936 | __journal_remove_journal_head(bh); |
bb189247 | 1937 | jbd_unlock_bh_journal_head(bh); |
1da177e4 | 1938 | __brelse(bh); |
bb189247 JK |
1939 | } else |
1940 | jbd_unlock_bh_journal_head(bh); | |
1da177e4 LT |
1941 | } |
1942 | ||
1943 | /* | |
c2a9159c | 1944 | * debugfs tunables |
1da177e4 | 1945 | */ |
c2a9159c | 1946 | #ifdef CONFIG_JBD_DEBUG |
1da177e4 | 1947 | |
c2a9159c JS |
1948 | u8 journal_enable_debug __read_mostly; |
1949 | EXPORT_SYMBOL(journal_enable_debug); | |
1da177e4 | 1950 | |
c2a9159c JS |
1951 | static struct dentry *jbd_debugfs_dir; |
1952 | static struct dentry *jbd_debug; | |
1da177e4 | 1953 | |
c2a9159c | 1954 | static void __init jbd_create_debugfs_entry(void) |
1da177e4 | 1955 | { |
c2a9159c JS |
1956 | jbd_debugfs_dir = debugfs_create_dir("jbd", NULL); |
1957 | if (jbd_debugfs_dir) | |
765f8361 | 1958 | jbd_debug = debugfs_create_u8("jbd-debug", S_IRUGO | S_IWUSR, |
c2a9159c JS |
1959 | jbd_debugfs_dir, |
1960 | &journal_enable_debug); | |
1da177e4 LT |
1961 | } |
1962 | ||
c2a9159c | 1963 | static void __exit jbd_remove_debugfs_entry(void) |
1da177e4 | 1964 | { |
c2a9159c JS |
1965 | debugfs_remove(jbd_debug); |
1966 | debugfs_remove(jbd_debugfs_dir); | |
1da177e4 LT |
1967 | } |
1968 | ||
c2a9159c | 1969 | #else |
1da177e4 | 1970 | |
c2a9159c | 1971 | static inline void jbd_create_debugfs_entry(void) |
1da177e4 | 1972 | { |
1da177e4 LT |
1973 | } |
1974 | ||
c2a9159c | 1975 | static inline void jbd_remove_debugfs_entry(void) |
1da177e4 | 1976 | { |
1da177e4 LT |
1977 | } |
1978 | ||
1da177e4 LT |
1979 | #endif |
1980 | ||
e18b890b | 1981 | struct kmem_cache *jbd_handle_cache; |
1da177e4 LT |
1982 | |
1983 | static int __init journal_init_handle_cache(void) | |
1984 | { | |
1985 | jbd_handle_cache = kmem_cache_create("journal_handle", | |
1986 | sizeof(handle_t), | |
1987 | 0, /* offset */ | |
e12ba74d | 1988 | SLAB_TEMPORARY, /* flags */ |
20c2df83 | 1989 | NULL); /* ctor */ |
1da177e4 LT |
1990 | if (jbd_handle_cache == NULL) { |
1991 | printk(KERN_EMERG "JBD: failed to create handle cache\n"); | |
1992 | return -ENOMEM; | |
1993 | } | |
1994 | return 0; | |
1995 | } | |
1996 | ||
1997 | static void journal_destroy_handle_cache(void) | |
1998 | { | |
1999 | if (jbd_handle_cache) | |
2000 | kmem_cache_destroy(jbd_handle_cache); | |
2001 | } | |
2002 | ||
2003 | /* | |
2004 | * Module startup and shutdown | |
2005 | */ | |
2006 | ||
2007 | static int __init journal_init_caches(void) | |
2008 | { | |
2009 | int ret; | |
2010 | ||
2011 | ret = journal_init_revoke_caches(); | |
2012 | if (ret == 0) | |
2013 | ret = journal_init_journal_head_cache(); | |
2014 | if (ret == 0) | |
2015 | ret = journal_init_handle_cache(); | |
2016 | return ret; | |
2017 | } | |
2018 | ||
2019 | static void journal_destroy_caches(void) | |
2020 | { | |
2021 | journal_destroy_revoke_caches(); | |
2022 | journal_destroy_journal_head_cache(); | |
2023 | journal_destroy_handle_cache(); | |
2024 | } | |
2025 | ||
2026 | static int __init journal_init(void) | |
2027 | { | |
2028 | int ret; | |
2029 | ||
2aed3484 | 2030 | BUILD_BUG_ON(sizeof(struct journal_superblock_s) != 1024); |
022a4a7b | 2031 | |
1da177e4 LT |
2032 | ret = journal_init_caches(); |
2033 | if (ret != 0) | |
2034 | journal_destroy_caches(); | |
c2a9159c | 2035 | jbd_create_debugfs_entry(); |
1da177e4 LT |
2036 | return ret; |
2037 | } | |
2038 | ||
2039 | static void __exit journal_exit(void) | |
2040 | { | |
2041 | #ifdef CONFIG_JBD_DEBUG | |
2042 | int n = atomic_read(&nr_journal_heads); | |
2043 | if (n) | |
2044 | printk(KERN_EMERG "JBD: leaked %d journal_heads!\n", n); | |
2045 | #endif | |
c2a9159c | 2046 | jbd_remove_debugfs_entry(); |
1da177e4 LT |
2047 | journal_destroy_caches(); |
2048 | } | |
2049 | ||
2050 | MODULE_LICENSE("GPL"); | |
2051 | module_init(journal_init); | |
2052 | module_exit(journal_exit); | |
2053 |