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1 | /* | |
2 | * linux/fs/jbd2/checkpoint.c | |
3 | * | |
4 | * Written by Stephen C. Tweedie <sct@redhat.com>, 1999 | |
5 | * | |
6 | * Copyright 1999 Red Hat Software --- 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 | * Checkpoint routines for the generic filesystem journaling code. | |
13 | * Part of the ext2fs journaling system. | |
14 | * | |
15 | * Checkpointing is the process of ensuring that a section of the log is | |
16 | * committed fully to disk, so that that portion of the log can be | |
17 | * reused. | |
18 | */ | |
19 | ||
20 | #include <linux/time.h> | |
21 | #include <linux/fs.h> | |
22 | #include <linux/jbd2.h> | |
23 | #include <linux/errno.h> | |
24 | #include <linux/slab.h> | |
25 | #include <linux/blkdev.h> | |
26 | #include <trace/events/jbd2.h> | |
27 | ||
28 | /* | |
29 | * Unlink a buffer from a transaction checkpoint list. | |
30 | * | |
31 | * Called with j_list_lock held. | |
32 | */ | |
33 | static inline void __buffer_unlink_first(struct journal_head *jh) | |
34 | { | |
35 | transaction_t *transaction = jh->b_cp_transaction; | |
36 | ||
37 | jh->b_cpnext->b_cpprev = jh->b_cpprev; | |
38 | jh->b_cpprev->b_cpnext = jh->b_cpnext; | |
39 | if (transaction->t_checkpoint_list == jh) { | |
40 | transaction->t_checkpoint_list = jh->b_cpnext; | |
41 | if (transaction->t_checkpoint_list == jh) | |
42 | transaction->t_checkpoint_list = NULL; | |
43 | } | |
44 | } | |
45 | ||
46 | /* | |
47 | * Unlink a buffer from a transaction checkpoint(io) list. | |
48 | * | |
49 | * Called with j_list_lock held. | |
50 | */ | |
51 | static inline void __buffer_unlink(struct journal_head *jh) | |
52 | { | |
53 | transaction_t *transaction = jh->b_cp_transaction; | |
54 | ||
55 | __buffer_unlink_first(jh); | |
56 | if (transaction->t_checkpoint_io_list == jh) { | |
57 | transaction->t_checkpoint_io_list = jh->b_cpnext; | |
58 | if (transaction->t_checkpoint_io_list == jh) | |
59 | transaction->t_checkpoint_io_list = NULL; | |
60 | } | |
61 | } | |
62 | ||
63 | /* | |
64 | * Move a buffer from the checkpoint list to the checkpoint io list | |
65 | * | |
66 | * Called with j_list_lock held | |
67 | */ | |
68 | static inline void __buffer_relink_io(struct journal_head *jh) | |
69 | { | |
70 | transaction_t *transaction = jh->b_cp_transaction; | |
71 | ||
72 | __buffer_unlink_first(jh); | |
73 | ||
74 | if (!transaction->t_checkpoint_io_list) { | |
75 | jh->b_cpnext = jh->b_cpprev = jh; | |
76 | } else { | |
77 | jh->b_cpnext = transaction->t_checkpoint_io_list; | |
78 | jh->b_cpprev = transaction->t_checkpoint_io_list->b_cpprev; | |
79 | jh->b_cpprev->b_cpnext = jh; | |
80 | jh->b_cpnext->b_cpprev = jh; | |
81 | } | |
82 | transaction->t_checkpoint_io_list = jh; | |
83 | } | |
84 | ||
85 | /* | |
86 | * Try to release a checkpointed buffer from its transaction. | |
87 | * Returns 1 if we released it and 2 if we also released the | |
88 | * whole transaction. | |
89 | * | |
90 | * Requires j_list_lock | |
91 | */ | |
92 | static int __try_to_free_cp_buf(struct journal_head *jh) | |
93 | { | |
94 | int ret = 0; | |
95 | struct buffer_head *bh = jh2bh(jh); | |
96 | ||
97 | if (jh->b_transaction == NULL && !buffer_locked(bh) && | |
98 | !buffer_dirty(bh) && !buffer_write_io_error(bh)) { | |
99 | JBUFFER_TRACE(jh, "remove from checkpoint list"); | |
100 | ret = __jbd2_journal_remove_checkpoint(jh) + 1; | |
101 | } | |
102 | return ret; | |
103 | } | |
104 | ||
105 | /* | |
106 | * __jbd2_log_wait_for_space: wait until there is space in the journal. | |
107 | * | |
108 | * Called under j-state_lock *only*. It will be unlocked if we have to wait | |
109 | * for a checkpoint to free up some space in the log. | |
110 | */ | |
111 | void __jbd2_log_wait_for_space(journal_t *journal) | |
112 | { | |
113 | int nblocks, space_left; | |
114 | /* assert_spin_locked(&journal->j_state_lock); */ | |
115 | ||
116 | nblocks = jbd2_space_needed(journal); | |
117 | while (jbd2_log_space_left(journal) < nblocks) { | |
118 | write_unlock(&journal->j_state_lock); | |
119 | mutex_lock(&journal->j_checkpoint_mutex); | |
120 | ||
121 | /* | |
122 | * Test again, another process may have checkpointed while we | |
123 | * were waiting for the checkpoint lock. If there are no | |
124 | * transactions ready to be checkpointed, try to recover | |
125 | * journal space by calling cleanup_journal_tail(), and if | |
126 | * that doesn't work, by waiting for the currently committing | |
127 | * transaction to complete. If there is absolutely no way | |
128 | * to make progress, this is either a BUG or corrupted | |
129 | * filesystem, so abort the journal and leave a stack | |
130 | * trace for forensic evidence. | |
131 | */ | |
132 | write_lock(&journal->j_state_lock); | |
133 | if (journal->j_flags & JBD2_ABORT) { | |
134 | mutex_unlock(&journal->j_checkpoint_mutex); | |
135 | return; | |
136 | } | |
137 | spin_lock(&journal->j_list_lock); | |
138 | nblocks = jbd2_space_needed(journal); | |
139 | space_left = jbd2_log_space_left(journal); | |
140 | if (space_left < nblocks) { | |
141 | int chkpt = journal->j_checkpoint_transactions != NULL; | |
142 | tid_t tid = 0; | |
143 | ||
144 | if (journal->j_committing_transaction) | |
145 | tid = journal->j_committing_transaction->t_tid; | |
146 | spin_unlock(&journal->j_list_lock); | |
147 | write_unlock(&journal->j_state_lock); | |
148 | if (chkpt) { | |
149 | jbd2_log_do_checkpoint(journal); | |
150 | } else if (jbd2_cleanup_journal_tail(journal) == 0) { | |
151 | /* We were able to recover space; yay! */ | |
152 | ; | |
153 | } else if (tid) { | |
154 | /* | |
155 | * jbd2_journal_commit_transaction() may want | |
156 | * to take the checkpoint_mutex if JBD2_FLUSHED | |
157 | * is set. So we need to temporarily drop it. | |
158 | */ | |
159 | mutex_unlock(&journal->j_checkpoint_mutex); | |
160 | jbd2_log_wait_commit(journal, tid); | |
161 | write_lock(&journal->j_state_lock); | |
162 | continue; | |
163 | } else { | |
164 | printk(KERN_ERR "%s: needed %d blocks and " | |
165 | "only had %d space available\n", | |
166 | __func__, nblocks, space_left); | |
167 | printk(KERN_ERR "%s: no way to get more " | |
168 | "journal space in %s\n", __func__, | |
169 | journal->j_devname); | |
170 | WARN_ON(1); | |
171 | jbd2_journal_abort(journal, 0); | |
172 | } | |
173 | write_lock(&journal->j_state_lock); | |
174 | } else { | |
175 | spin_unlock(&journal->j_list_lock); | |
176 | } | |
177 | mutex_unlock(&journal->j_checkpoint_mutex); | |
178 | } | |
179 | } | |
180 | ||
181 | static void | |
182 | __flush_batch(journal_t *journal, int *batch_count) | |
183 | { | |
184 | int i; | |
185 | struct blk_plug plug; | |
186 | ||
187 | blk_start_plug(&plug); | |
188 | for (i = 0; i < *batch_count; i++) | |
189 | write_dirty_buffer(journal->j_chkpt_bhs[i], WRITE_SYNC); | |
190 | blk_finish_plug(&plug); | |
191 | ||
192 | for (i = 0; i < *batch_count; i++) { | |
193 | struct buffer_head *bh = journal->j_chkpt_bhs[i]; | |
194 | BUFFER_TRACE(bh, "brelse"); | |
195 | __brelse(bh); | |
196 | } | |
197 | *batch_count = 0; | |
198 | } | |
199 | ||
200 | /* | |
201 | * Perform an actual checkpoint. We take the first transaction on the | |
202 | * list of transactions to be checkpointed and send all its buffers | |
203 | * to disk. We submit larger chunks of data at once. | |
204 | * | |
205 | * The journal should be locked before calling this function. | |
206 | * Called with j_checkpoint_mutex held. | |
207 | */ | |
208 | int jbd2_log_do_checkpoint(journal_t *journal) | |
209 | { | |
210 | struct journal_head *jh; | |
211 | struct buffer_head *bh; | |
212 | transaction_t *transaction; | |
213 | tid_t this_tid; | |
214 | int result, batch_count = 0; | |
215 | ||
216 | jbd_debug(1, "Start checkpoint\n"); | |
217 | ||
218 | /* | |
219 | * First thing: if there are any transactions in the log which | |
220 | * don't need checkpointing, just eliminate them from the | |
221 | * journal straight away. | |
222 | */ | |
223 | result = jbd2_cleanup_journal_tail(journal); | |
224 | trace_jbd2_checkpoint(journal, result); | |
225 | jbd_debug(1, "cleanup_journal_tail returned %d\n", result); | |
226 | if (result <= 0) | |
227 | return result; | |
228 | ||
229 | /* | |
230 | * OK, we need to start writing disk blocks. Take one transaction | |
231 | * and write it. | |
232 | */ | |
233 | result = 0; | |
234 | spin_lock(&journal->j_list_lock); | |
235 | if (!journal->j_checkpoint_transactions) | |
236 | goto out; | |
237 | transaction = journal->j_checkpoint_transactions; | |
238 | if (transaction->t_chp_stats.cs_chp_time == 0) | |
239 | transaction->t_chp_stats.cs_chp_time = jiffies; | |
240 | this_tid = transaction->t_tid; | |
241 | restart: | |
242 | /* | |
243 | * If someone cleaned up this transaction while we slept, we're | |
244 | * done (maybe it's a new transaction, but it fell at the same | |
245 | * address). | |
246 | */ | |
247 | if (journal->j_checkpoint_transactions != transaction || | |
248 | transaction->t_tid != this_tid) | |
249 | goto out; | |
250 | ||
251 | /* checkpoint all of the transaction's buffers */ | |
252 | while (transaction->t_checkpoint_list) { | |
253 | jh = transaction->t_checkpoint_list; | |
254 | bh = jh2bh(jh); | |
255 | ||
256 | if (buffer_locked(bh)) { | |
257 | spin_unlock(&journal->j_list_lock); | |
258 | get_bh(bh); | |
259 | wait_on_buffer(bh); | |
260 | /* the journal_head may have gone by now */ | |
261 | BUFFER_TRACE(bh, "brelse"); | |
262 | __brelse(bh); | |
263 | goto retry; | |
264 | } | |
265 | if (jh->b_transaction != NULL) { | |
266 | transaction_t *t = jh->b_transaction; | |
267 | tid_t tid = t->t_tid; | |
268 | ||
269 | transaction->t_chp_stats.cs_forced_to_close++; | |
270 | spin_unlock(&journal->j_list_lock); | |
271 | if (unlikely(journal->j_flags & JBD2_UNMOUNT)) | |
272 | /* | |
273 | * The journal thread is dead; so | |
274 | * starting and waiting for a commit | |
275 | * to finish will cause us to wait for | |
276 | * a _very_ long time. | |
277 | */ | |
278 | printk(KERN_ERR | |
279 | "JBD2: %s: Waiting for Godot: block %llu\n", | |
280 | journal->j_devname, (unsigned long long) bh->b_blocknr); | |
281 | ||
282 | jbd2_log_start_commit(journal, tid); | |
283 | jbd2_log_wait_commit(journal, tid); | |
284 | goto retry; | |
285 | } | |
286 | if (!buffer_dirty(bh)) { | |
287 | if (unlikely(buffer_write_io_error(bh)) && !result) | |
288 | result = -EIO; | |
289 | BUFFER_TRACE(bh, "remove from checkpoint"); | |
290 | if (__jbd2_journal_remove_checkpoint(jh)) | |
291 | /* The transaction was released; we're done */ | |
292 | goto out; | |
293 | continue; | |
294 | } | |
295 | /* | |
296 | * Important: we are about to write the buffer, and | |
297 | * possibly block, while still holding the journal | |
298 | * lock. We cannot afford to let the transaction | |
299 | * logic start messing around with this buffer before | |
300 | * we write it to disk, as that would break | |
301 | * recoverability. | |
302 | */ | |
303 | BUFFER_TRACE(bh, "queue"); | |
304 | get_bh(bh); | |
305 | J_ASSERT_BH(bh, !buffer_jwrite(bh)); | |
306 | journal->j_chkpt_bhs[batch_count++] = bh; | |
307 | __buffer_relink_io(jh); | |
308 | transaction->t_chp_stats.cs_written++; | |
309 | if ((batch_count == JBD2_NR_BATCH) || | |
310 | need_resched() || | |
311 | spin_needbreak(&journal->j_list_lock)) | |
312 | goto unlock_and_flush; | |
313 | } | |
314 | ||
315 | if (batch_count) { | |
316 | unlock_and_flush: | |
317 | spin_unlock(&journal->j_list_lock); | |
318 | retry: | |
319 | if (batch_count) | |
320 | __flush_batch(journal, &batch_count); | |
321 | spin_lock(&journal->j_list_lock); | |
322 | goto restart; | |
323 | } | |
324 | ||
325 | /* | |
326 | * Now we issued all of the transaction's buffers, let's deal | |
327 | * with the buffers that are out for I/O. | |
328 | */ | |
329 | restart2: | |
330 | /* Did somebody clean up the transaction in the meanwhile? */ | |
331 | if (journal->j_checkpoint_transactions != transaction || | |
332 | transaction->t_tid != this_tid) | |
333 | goto out; | |
334 | ||
335 | while (transaction->t_checkpoint_io_list) { | |
336 | jh = transaction->t_checkpoint_io_list; | |
337 | bh = jh2bh(jh); | |
338 | if (buffer_locked(bh)) { | |
339 | spin_unlock(&journal->j_list_lock); | |
340 | get_bh(bh); | |
341 | wait_on_buffer(bh); | |
342 | /* the journal_head may have gone by now */ | |
343 | BUFFER_TRACE(bh, "brelse"); | |
344 | __brelse(bh); | |
345 | spin_lock(&journal->j_list_lock); | |
346 | goto restart2; | |
347 | } | |
348 | if (unlikely(buffer_write_io_error(bh)) && !result) | |
349 | result = -EIO; | |
350 | ||
351 | /* | |
352 | * Now in whatever state the buffer currently is, we | |
353 | * know that it has been written out and so we can | |
354 | * drop it from the list | |
355 | */ | |
356 | if (__jbd2_journal_remove_checkpoint(jh)) | |
357 | break; | |
358 | } | |
359 | out: | |
360 | spin_unlock(&journal->j_list_lock); | |
361 | if (result < 0) | |
362 | jbd2_journal_abort(journal, result); | |
363 | else | |
364 | result = jbd2_cleanup_journal_tail(journal); | |
365 | ||
366 | return (result < 0) ? result : 0; | |
367 | } | |
368 | ||
369 | /* | |
370 | * Check the list of checkpoint transactions for the journal to see if | |
371 | * we have already got rid of any since the last update of the log tail | |
372 | * in the journal superblock. If so, we can instantly roll the | |
373 | * superblock forward to remove those transactions from the log. | |
374 | * | |
375 | * Return <0 on error, 0 on success, 1 if there was nothing to clean up. | |
376 | * | |
377 | * Called with the journal lock held. | |
378 | * | |
379 | * This is the only part of the journaling code which really needs to be | |
380 | * aware of transaction aborts. Checkpointing involves writing to the | |
381 | * main filesystem area rather than to the journal, so it can proceed | |
382 | * even in abort state, but we must not update the super block if | |
383 | * checkpointing may have failed. Otherwise, we would lose some metadata | |
384 | * buffers which should be written-back to the filesystem. | |
385 | */ | |
386 | ||
387 | int jbd2_cleanup_journal_tail(journal_t *journal) | |
388 | { | |
389 | tid_t first_tid; | |
390 | unsigned long blocknr; | |
391 | ||
392 | if (is_journal_aborted(journal)) | |
393 | return -EIO; | |
394 | ||
395 | if (!jbd2_journal_get_log_tail(journal, &first_tid, &blocknr)) | |
396 | return 1; | |
397 | J_ASSERT(blocknr != 0); | |
398 | ||
399 | /* | |
400 | * We need to make sure that any blocks that were recently written out | |
401 | * --- perhaps by jbd2_log_do_checkpoint() --- are flushed out before | |
402 | * we drop the transactions from the journal. It's unlikely this will | |
403 | * be necessary, especially with an appropriately sized journal, but we | |
404 | * need this to guarantee correctness. Fortunately | |
405 | * jbd2_cleanup_journal_tail() doesn't get called all that often. | |
406 | */ | |
407 | if (journal->j_flags & JBD2_BARRIER) | |
408 | blkdev_issue_flush(journal->j_fs_dev, GFP_NOFS, NULL); | |
409 | ||
410 | return __jbd2_update_log_tail(journal, first_tid, blocknr); | |
411 | } | |
412 | ||
413 | ||
414 | /* Checkpoint list management */ | |
415 | ||
416 | /* | |
417 | * journal_clean_one_cp_list | |
418 | * | |
419 | * Find all the written-back checkpoint buffers in the given list and | |
420 | * release them. If 'destroy' is set, clean all buffers unconditionally. | |
421 | * | |
422 | * Called with j_list_lock held. | |
423 | * Returns 1 if we freed the transaction, 0 otherwise. | |
424 | */ | |
425 | static int journal_clean_one_cp_list(struct journal_head *jh, bool destroy) | |
426 | { | |
427 | struct journal_head *last_jh; | |
428 | struct journal_head *next_jh = jh; | |
429 | int ret; | |
430 | ||
431 | if (!jh) | |
432 | return 0; | |
433 | ||
434 | last_jh = jh->b_cpprev; | |
435 | do { | |
436 | jh = next_jh; | |
437 | next_jh = jh->b_cpnext; | |
438 | if (!destroy) | |
439 | ret = __try_to_free_cp_buf(jh); | |
440 | else | |
441 | ret = __jbd2_journal_remove_checkpoint(jh) + 1; | |
442 | if (!ret) | |
443 | return 0; | |
444 | if (ret == 2) | |
445 | return 1; | |
446 | /* | |
447 | * This function only frees up some memory | |
448 | * if possible so we dont have an obligation | |
449 | * to finish processing. Bail out if preemption | |
450 | * requested: | |
451 | */ | |
452 | if (need_resched()) | |
453 | return 0; | |
454 | } while (jh != last_jh); | |
455 | ||
456 | return 0; | |
457 | } | |
458 | ||
459 | /* | |
460 | * journal_clean_checkpoint_list | |
461 | * | |
462 | * Find all the written-back checkpoint buffers in the journal and release them. | |
463 | * If 'destroy' is set, release all buffers unconditionally. | |
464 | * | |
465 | * Called with j_list_lock held. | |
466 | */ | |
467 | void __jbd2_journal_clean_checkpoint_list(journal_t *journal, bool destroy) | |
468 | { | |
469 | transaction_t *transaction, *last_transaction, *next_transaction; | |
470 | int ret; | |
471 | ||
472 | transaction = journal->j_checkpoint_transactions; | |
473 | if (!transaction) | |
474 | return; | |
475 | ||
476 | last_transaction = transaction->t_cpprev; | |
477 | next_transaction = transaction; | |
478 | do { | |
479 | transaction = next_transaction; | |
480 | next_transaction = transaction->t_cpnext; | |
481 | ret = journal_clean_one_cp_list(transaction->t_checkpoint_list, | |
482 | destroy); | |
483 | /* | |
484 | * This function only frees up some memory if possible so we | |
485 | * dont have an obligation to finish processing. Bail out if | |
486 | * preemption requested: | |
487 | */ | |
488 | if (need_resched()) | |
489 | return; | |
490 | if (ret) | |
491 | continue; | |
492 | /* | |
493 | * It is essential that we are as careful as in the case of | |
494 | * t_checkpoint_list with removing the buffer from the list as | |
495 | * we can possibly see not yet submitted buffers on io_list | |
496 | */ | |
497 | ret = journal_clean_one_cp_list(transaction-> | |
498 | t_checkpoint_io_list, destroy); | |
499 | if (need_resched()) | |
500 | return; | |
501 | /* | |
502 | * Stop scanning if we couldn't free the transaction. This | |
503 | * avoids pointless scanning of transactions which still | |
504 | * weren't checkpointed. | |
505 | */ | |
506 | if (!ret) | |
507 | return; | |
508 | } while (transaction != last_transaction); | |
509 | } | |
510 | ||
511 | /* | |
512 | * Remove buffers from all checkpoint lists as journal is aborted and we just | |
513 | * need to free memory | |
514 | */ | |
515 | void jbd2_journal_destroy_checkpoint(journal_t *journal) | |
516 | { | |
517 | /* | |
518 | * We loop because __jbd2_journal_clean_checkpoint_list() may abort | |
519 | * early due to a need of rescheduling. | |
520 | */ | |
521 | while (1) { | |
522 | spin_lock(&journal->j_list_lock); | |
523 | if (!journal->j_checkpoint_transactions) { | |
524 | spin_unlock(&journal->j_list_lock); | |
525 | break; | |
526 | } | |
527 | __jbd2_journal_clean_checkpoint_list(journal, true); | |
528 | spin_unlock(&journal->j_list_lock); | |
529 | cond_resched(); | |
530 | } | |
531 | } | |
532 | ||
533 | /* | |
534 | * journal_remove_checkpoint: called after a buffer has been committed | |
535 | * to disk (either by being write-back flushed to disk, or being | |
536 | * committed to the log). | |
537 | * | |
538 | * We cannot safely clean a transaction out of the log until all of the | |
539 | * buffer updates committed in that transaction have safely been stored | |
540 | * elsewhere on disk. To achieve this, all of the buffers in a | |
541 | * transaction need to be maintained on the transaction's checkpoint | |
542 | * lists until they have been rewritten, at which point this function is | |
543 | * called to remove the buffer from the existing transaction's | |
544 | * checkpoint lists. | |
545 | * | |
546 | * The function returns 1 if it frees the transaction, 0 otherwise. | |
547 | * The function can free jh and bh. | |
548 | * | |
549 | * This function is called with j_list_lock held. | |
550 | */ | |
551 | int __jbd2_journal_remove_checkpoint(struct journal_head *jh) | |
552 | { | |
553 | struct transaction_chp_stats_s *stats; | |
554 | transaction_t *transaction; | |
555 | journal_t *journal; | |
556 | int ret = 0; | |
557 | ||
558 | JBUFFER_TRACE(jh, "entry"); | |
559 | ||
560 | if ((transaction = jh->b_cp_transaction) == NULL) { | |
561 | JBUFFER_TRACE(jh, "not on transaction"); | |
562 | goto out; | |
563 | } | |
564 | journal = transaction->t_journal; | |
565 | ||
566 | JBUFFER_TRACE(jh, "removing from transaction"); | |
567 | __buffer_unlink(jh); | |
568 | jh->b_cp_transaction = NULL; | |
569 | jbd2_journal_put_journal_head(jh); | |
570 | ||
571 | if (transaction->t_checkpoint_list != NULL || | |
572 | transaction->t_checkpoint_io_list != NULL) | |
573 | goto out; | |
574 | ||
575 | /* | |
576 | * There is one special case to worry about: if we have just pulled the | |
577 | * buffer off a running or committing transaction's checkpoing list, | |
578 | * then even if the checkpoint list is empty, the transaction obviously | |
579 | * cannot be dropped! | |
580 | * | |
581 | * The locking here around t_state is a bit sleazy. | |
582 | * See the comment at the end of jbd2_journal_commit_transaction(). | |
583 | */ | |
584 | if (transaction->t_state != T_FINISHED) | |
585 | goto out; | |
586 | ||
587 | /* OK, that was the last buffer for the transaction: we can now | |
588 | safely remove this transaction from the log */ | |
589 | stats = &transaction->t_chp_stats; | |
590 | if (stats->cs_chp_time) | |
591 | stats->cs_chp_time = jbd2_time_diff(stats->cs_chp_time, | |
592 | jiffies); | |
593 | trace_jbd2_checkpoint_stats(journal->j_fs_dev->bd_dev, | |
594 | transaction->t_tid, stats); | |
595 | ||
596 | __jbd2_journal_drop_transaction(journal, transaction); | |
597 | jbd2_journal_free_transaction(transaction); | |
598 | ret = 1; | |
599 | out: | |
600 | return ret; | |
601 | } | |
602 | ||
603 | /* | |
604 | * journal_insert_checkpoint: put a committed buffer onto a checkpoint | |
605 | * list so that we know when it is safe to clean the transaction out of | |
606 | * the log. | |
607 | * | |
608 | * Called with the journal locked. | |
609 | * Called with j_list_lock held. | |
610 | */ | |
611 | void __jbd2_journal_insert_checkpoint(struct journal_head *jh, | |
612 | transaction_t *transaction) | |
613 | { | |
614 | JBUFFER_TRACE(jh, "entry"); | |
615 | J_ASSERT_JH(jh, buffer_dirty(jh2bh(jh)) || buffer_jbddirty(jh2bh(jh))); | |
616 | J_ASSERT_JH(jh, jh->b_cp_transaction == NULL); | |
617 | ||
618 | /* Get reference for checkpointing transaction */ | |
619 | jbd2_journal_grab_journal_head(jh2bh(jh)); | |
620 | jh->b_cp_transaction = transaction; | |
621 | ||
622 | if (!transaction->t_checkpoint_list) { | |
623 | jh->b_cpnext = jh->b_cpprev = jh; | |
624 | } else { | |
625 | jh->b_cpnext = transaction->t_checkpoint_list; | |
626 | jh->b_cpprev = transaction->t_checkpoint_list->b_cpprev; | |
627 | jh->b_cpprev->b_cpnext = jh; | |
628 | jh->b_cpnext->b_cpprev = jh; | |
629 | } | |
630 | transaction->t_checkpoint_list = jh; | |
631 | } | |
632 | ||
633 | /* | |
634 | * We've finished with this transaction structure: adios... | |
635 | * | |
636 | * The transaction must have no links except for the checkpoint by this | |
637 | * point. | |
638 | * | |
639 | * Called with the journal locked. | |
640 | * Called with j_list_lock held. | |
641 | */ | |
642 | ||
643 | void __jbd2_journal_drop_transaction(journal_t *journal, transaction_t *transaction) | |
644 | { | |
645 | assert_spin_locked(&journal->j_list_lock); | |
646 | if (transaction->t_cpnext) { | |
647 | transaction->t_cpnext->t_cpprev = transaction->t_cpprev; | |
648 | transaction->t_cpprev->t_cpnext = transaction->t_cpnext; | |
649 | if (journal->j_checkpoint_transactions == transaction) | |
650 | journal->j_checkpoint_transactions = | |
651 | transaction->t_cpnext; | |
652 | if (journal->j_checkpoint_transactions == transaction) | |
653 | journal->j_checkpoint_transactions = NULL; | |
654 | } | |
655 | ||
656 | J_ASSERT(transaction->t_state == T_FINISHED); | |
657 | J_ASSERT(transaction->t_buffers == NULL); | |
658 | J_ASSERT(transaction->t_forget == NULL); | |
659 | J_ASSERT(transaction->t_shadow_list == NULL); | |
660 | J_ASSERT(transaction->t_checkpoint_list == NULL); | |
661 | J_ASSERT(transaction->t_checkpoint_io_list == NULL); | |
662 | J_ASSERT(atomic_read(&transaction->t_updates) == 0); | |
663 | J_ASSERT(journal->j_committing_transaction != transaction); | |
664 | J_ASSERT(journal->j_running_transaction != transaction); | |
665 | ||
666 | trace_jbd2_drop_transaction(journal, transaction); | |
667 | ||
668 | jbd_debug(1, "Dropping transaction %d, all done\n", transaction->t_tid); | |
669 | } |