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f5166768 | 1 | // SPDX-License-Identifier: GPL-2.0+ |
470decc6 | 2 | /* |
58862699 | 3 | * linux/fs/jbd2/checkpoint.c |
470decc6 DK |
4 | * |
5 | * Written by Stephen C. Tweedie <sct@redhat.com>, 1999 | |
6 | * | |
7 | * Copyright 1999 Red Hat Software --- All Rights Reserved | |
8 | * | |
470decc6 DK |
9 | * Checkpoint routines for the generic filesystem journaling code. |
10 | * Part of the ext2fs journaling system. | |
11 | * | |
12 | * Checkpointing is the process of ensuring that a section of the log is | |
13 | * committed fully to disk, so that that portion of the log can be | |
14 | * reused. | |
15 | */ | |
16 | ||
17 | #include <linux/time.h> | |
18 | #include <linux/fs.h> | |
f7f4bccb | 19 | #include <linux/jbd2.h> |
470decc6 DK |
20 | #include <linux/errno.h> |
21 | #include <linux/slab.h> | |
cc3e1bea | 22 | #include <linux/blkdev.h> |
879c5e6b | 23 | #include <trace/events/jbd2.h> |
470decc6 DK |
24 | |
25 | /* | |
26 | * Unlink a buffer from a transaction checkpoint list. | |
27 | * | |
28 | * Called with j_list_lock held. | |
29 | */ | |
30 | static inline void __buffer_unlink_first(struct journal_head *jh) | |
31 | { | |
32 | transaction_t *transaction = jh->b_cp_transaction; | |
33 | ||
34 | jh->b_cpnext->b_cpprev = jh->b_cpprev; | |
35 | jh->b_cpprev->b_cpnext = jh->b_cpnext; | |
36 | if (transaction->t_checkpoint_list == jh) { | |
37 | transaction->t_checkpoint_list = jh->b_cpnext; | |
38 | if (transaction->t_checkpoint_list == jh) | |
39 | transaction->t_checkpoint_list = NULL; | |
40 | } | |
41 | } | |
42 | ||
43 | /* | |
44 | * Unlink a buffer from a transaction checkpoint(io) list. | |
45 | * | |
46 | * Called with j_list_lock held. | |
47 | */ | |
48 | static inline void __buffer_unlink(struct journal_head *jh) | |
49 | { | |
50 | transaction_t *transaction = jh->b_cp_transaction; | |
51 | ||
52 | __buffer_unlink_first(jh); | |
53 | if (transaction->t_checkpoint_io_list == jh) { | |
54 | transaction->t_checkpoint_io_list = jh->b_cpnext; | |
55 | if (transaction->t_checkpoint_io_list == jh) | |
56 | transaction->t_checkpoint_io_list = NULL; | |
57 | } | |
58 | } | |
59 | ||
60 | /* | |
61 | * Move a buffer from the checkpoint list to the checkpoint io list | |
62 | * | |
63 | * Called with j_list_lock held | |
64 | */ | |
65 | static inline void __buffer_relink_io(struct journal_head *jh) | |
66 | { | |
67 | transaction_t *transaction = jh->b_cp_transaction; | |
68 | ||
69 | __buffer_unlink_first(jh); | |
70 | ||
71 | if (!transaction->t_checkpoint_io_list) { | |
72 | jh->b_cpnext = jh->b_cpprev = jh; | |
73 | } else { | |
74 | jh->b_cpnext = transaction->t_checkpoint_io_list; | |
75 | jh->b_cpprev = transaction->t_checkpoint_io_list->b_cpprev; | |
76 | jh->b_cpprev->b_cpnext = jh; | |
77 | jh->b_cpnext->b_cpprev = jh; | |
78 | } | |
79 | transaction->t_checkpoint_io_list = jh; | |
80 | } | |
81 | ||
82 | /* | |
83 | * Try to release a checkpointed buffer from its transaction. | |
84 | * Returns 1 if we released it and 2 if we also released the | |
85 | * whole transaction. | |
86 | * | |
87 | * Requires j_list_lock | |
470decc6 DK |
88 | */ |
89 | static int __try_to_free_cp_buf(struct journal_head *jh) | |
90 | { | |
91 | int ret = 0; | |
92 | struct buffer_head *bh = jh2bh(jh); | |
93 | ||
932bb305 | 94 | if (jh->b_transaction == NULL && !buffer_locked(bh) && |
44519faf | 95 | !buffer_dirty(bh) && !buffer_write_io_error(bh)) { |
470decc6 | 96 | JBUFFER_TRACE(jh, "remove from checkpoint list"); |
f7f4bccb | 97 | ret = __jbd2_journal_remove_checkpoint(jh) + 1; |
470decc6 DK |
98 | } |
99 | return ret; | |
100 | } | |
101 | ||
102 | /* | |
f7f4bccb | 103 | * __jbd2_log_wait_for_space: wait until there is space in the journal. |
470decc6 DK |
104 | * |
105 | * Called under j-state_lock *only*. It will be unlocked if we have to wait | |
106 | * for a checkpoint to free up some space in the log. | |
107 | */ | |
f7f4bccb | 108 | void __jbd2_log_wait_for_space(journal_t *journal) |
470decc6 | 109 | { |
8c3f25d8 | 110 | int nblocks, space_left; |
a931da6a | 111 | /* assert_spin_locked(&journal->j_state_lock); */ |
470decc6 | 112 | |
77444ac4 | 113 | nblocks = journal->j_max_transaction_buffers; |
76c39904 | 114 | while (jbd2_log_space_left(journal) < nblocks) { |
a931da6a | 115 | write_unlock(&journal->j_state_lock); |
53cf9784 | 116 | mutex_lock_io(&journal->j_checkpoint_mutex); |
470decc6 DK |
117 | |
118 | /* | |
119 | * Test again, another process may have checkpointed while we | |
23f8b79e | 120 | * were waiting for the checkpoint lock. If there are no |
8c3f25d8 TT |
121 | * transactions ready to be checkpointed, try to recover |
122 | * journal space by calling cleanup_journal_tail(), and if | |
123 | * that doesn't work, by waiting for the currently committing | |
124 | * transaction to complete. If there is absolutely no way | |
125 | * to make progress, this is either a BUG or corrupted | |
126 | * filesystem, so abort the journal and leave a stack | |
127 | * trace for forensic evidence. | |
470decc6 | 128 | */ |
a931da6a | 129 | write_lock(&journal->j_state_lock); |
1245799f DM |
130 | if (journal->j_flags & JBD2_ABORT) { |
131 | mutex_unlock(&journal->j_checkpoint_mutex); | |
132 | return; | |
133 | } | |
23f8b79e | 134 | spin_lock(&journal->j_list_lock); |
76c39904 | 135 | space_left = jbd2_log_space_left(journal); |
8c3f25d8 | 136 | if (space_left < nblocks) { |
23f8b79e | 137 | int chkpt = journal->j_checkpoint_transactions != NULL; |
8c3f25d8 | 138 | tid_t tid = 0; |
23f8b79e | 139 | |
8c3f25d8 TT |
140 | if (journal->j_committing_transaction) |
141 | tid = journal->j_committing_transaction->t_tid; | |
23f8b79e | 142 | spin_unlock(&journal->j_list_lock); |
a931da6a | 143 | write_unlock(&journal->j_state_lock); |
23f8b79e DG |
144 | if (chkpt) { |
145 | jbd2_log_do_checkpoint(journal); | |
8c3f25d8 TT |
146 | } else if (jbd2_cleanup_journal_tail(journal) == 0) { |
147 | /* We were able to recover space; yay! */ | |
148 | ; | |
149 | } else if (tid) { | |
0ef54180 PG |
150 | /* |
151 | * jbd2_journal_commit_transaction() may want | |
152 | * to take the checkpoint_mutex if JBD2_FLUSHED | |
153 | * is set. So we need to temporarily drop it. | |
154 | */ | |
155 | mutex_unlock(&journal->j_checkpoint_mutex); | |
8c3f25d8 | 156 | jbd2_log_wait_commit(journal, tid); |
0ef54180 PG |
157 | write_lock(&journal->j_state_lock); |
158 | continue; | |
23f8b79e | 159 | } else { |
8c3f25d8 TT |
160 | printk(KERN_ERR "%s: needed %d blocks and " |
161 | "only had %d space available\n", | |
162 | __func__, nblocks, space_left); | |
163 | printk(KERN_ERR "%s: no way to get more " | |
164 | "journal space in %s\n", __func__, | |
165 | journal->j_devname); | |
166 | WARN_ON(1); | |
51f57b01 | 167 | jbd2_journal_abort(journal, -EIO); |
23f8b79e | 168 | } |
a931da6a | 169 | write_lock(&journal->j_state_lock); |
23f8b79e DG |
170 | } else { |
171 | spin_unlock(&journal->j_list_lock); | |
470decc6 DK |
172 | } |
173 | mutex_unlock(&journal->j_checkpoint_mutex); | |
174 | } | |
175 | } | |
176 | ||
470decc6 | 177 | static void |
1a0d3786 | 178 | __flush_batch(journal_t *journal, int *batch_count) |
470decc6 DK |
179 | { |
180 | int i; | |
d3ad8434 | 181 | struct blk_plug plug; |
470decc6 | 182 | |
d3ad8434 | 183 | blk_start_plug(&plug); |
9cb569d6 | 184 | for (i = 0; i < *batch_count; i++) |
70fd7614 | 185 | write_dirty_buffer(journal->j_chkpt_bhs[i], REQ_SYNC); |
d3ad8434 | 186 | blk_finish_plug(&plug); |
9cb569d6 | 187 | |
470decc6 | 188 | for (i = 0; i < *batch_count; i++) { |
1a0d3786 | 189 | struct buffer_head *bh = journal->j_chkpt_bhs[i]; |
470decc6 DK |
190 | BUFFER_TRACE(bh, "brelse"); |
191 | __brelse(bh); | |
192 | } | |
193 | *batch_count = 0; | |
194 | } | |
195 | ||
470decc6 DK |
196 | /* |
197 | * Perform an actual checkpoint. We take the first transaction on the | |
198 | * list of transactions to be checkpointed and send all its buffers | |
199 | * to disk. We submit larger chunks of data at once. | |
200 | * | |
201 | * The journal should be locked before calling this function. | |
44519faf | 202 | * Called with j_checkpoint_mutex held. |
470decc6 | 203 | */ |
f7f4bccb | 204 | int jbd2_log_do_checkpoint(journal_t *journal) |
470decc6 | 205 | { |
be1158cc TT |
206 | struct journal_head *jh; |
207 | struct buffer_head *bh; | |
208 | transaction_t *transaction; | |
209 | tid_t this_tid; | |
dc6e8d66 | 210 | int result, batch_count = 0; |
470decc6 DK |
211 | |
212 | jbd_debug(1, "Start checkpoint\n"); | |
213 | ||
214 | /* | |
215 | * First thing: if there are any transactions in the log which | |
216 | * don't need checkpointing, just eliminate them from the | |
217 | * journal straight away. | |
218 | */ | |
f7f4bccb | 219 | result = jbd2_cleanup_journal_tail(journal); |
879c5e6b | 220 | trace_jbd2_checkpoint(journal, result); |
470decc6 DK |
221 | jbd_debug(1, "cleanup_journal_tail returned %d\n", result); |
222 | if (result <= 0) | |
223 | return result; | |
224 | ||
225 | /* | |
226 | * OK, we need to start writing disk blocks. Take one transaction | |
227 | * and write it. | |
228 | */ | |
44519faf | 229 | result = 0; |
470decc6 DK |
230 | spin_lock(&journal->j_list_lock); |
231 | if (!journal->j_checkpoint_transactions) | |
232 | goto out; | |
233 | transaction = journal->j_checkpoint_transactions; | |
8e85fb3f JL |
234 | if (transaction->t_chp_stats.cs_chp_time == 0) |
235 | transaction->t_chp_stats.cs_chp_time = jiffies; | |
470decc6 DK |
236 | this_tid = transaction->t_tid; |
237 | restart: | |
238 | /* | |
239 | * If someone cleaned up this transaction while we slept, we're | |
240 | * done (maybe it's a new transaction, but it fell at the same | |
241 | * address). | |
242 | */ | |
be1158cc TT |
243 | if (journal->j_checkpoint_transactions != transaction || |
244 | transaction->t_tid != this_tid) | |
245 | goto out; | |
470decc6 | 246 | |
be1158cc TT |
247 | /* checkpoint all of the transaction's buffers */ |
248 | while (transaction->t_checkpoint_list) { | |
249 | jh = transaction->t_checkpoint_list; | |
250 | bh = jh2bh(jh); | |
251 | ||
252 | if (buffer_locked(bh)) { | |
be1158cc | 253 | get_bh(bh); |
ccd3c437 | 254 | spin_unlock(&journal->j_list_lock); |
be1158cc TT |
255 | wait_on_buffer(bh); |
256 | /* the journal_head may have gone by now */ | |
257 | BUFFER_TRACE(bh, "brelse"); | |
258 | __brelse(bh); | |
259 | goto retry; | |
470decc6 | 260 | } |
be1158cc TT |
261 | if (jh->b_transaction != NULL) { |
262 | transaction_t *t = jh->b_transaction; | |
263 | tid_t tid = t->t_tid; | |
470decc6 | 264 | |
be1158cc TT |
265 | transaction->t_chp_stats.cs_forced_to_close++; |
266 | spin_unlock(&journal->j_list_lock); | |
267 | if (unlikely(journal->j_flags & JBD2_UNMOUNT)) | |
268 | /* | |
269 | * The journal thread is dead; so | |
270 | * starting and waiting for a commit | |
271 | * to finish will cause us to wait for | |
272 | * a _very_ long time. | |
273 | */ | |
274 | printk(KERN_ERR | |
275 | "JBD2: %s: Waiting for Godot: block %llu\n", | |
276 | journal->j_devname, (unsigned long long) bh->b_blocknr); | |
277 | ||
53cf9784 XW |
278 | if (batch_count) |
279 | __flush_batch(journal, &batch_count); | |
be1158cc | 280 | jbd2_log_start_commit(journal, tid); |
53cf9784 XW |
281 | /* |
282 | * jbd2_journal_commit_transaction() may want | |
283 | * to take the checkpoint_mutex if JBD2_FLUSHED | |
284 | * is set, jbd2_update_log_tail() called by | |
285 | * jbd2_journal_commit_transaction() may also take | |
286 | * checkpoint_mutex. So we need to temporarily | |
287 | * drop it. | |
288 | */ | |
289 | mutex_unlock(&journal->j_checkpoint_mutex); | |
be1158cc | 290 | jbd2_log_wait_commit(journal, tid); |
53cf9784 XW |
291 | mutex_lock_io(&journal->j_checkpoint_mutex); |
292 | spin_lock(&journal->j_list_lock); | |
293 | goto restart; | |
be1158cc TT |
294 | } |
295 | if (!buffer_dirty(bh)) { | |
296 | if (unlikely(buffer_write_io_error(bh)) && !result) | |
297 | result = -EIO; | |
be1158cc | 298 | BUFFER_TRACE(bh, "remove from checkpoint"); |
0e5ecf0a JK |
299 | if (__jbd2_journal_remove_checkpoint(jh)) |
300 | /* The transaction was released; we're done */ | |
301 | goto out; | |
302 | continue; | |
470decc6 DK |
303 | } |
304 | /* | |
be1158cc TT |
305 | * Important: we are about to write the buffer, and |
306 | * possibly block, while still holding the journal | |
307 | * lock. We cannot afford to let the transaction | |
308 | * logic start messing around with this buffer before | |
309 | * we write it to disk, as that would break | |
310 | * recoverability. | |
470decc6 | 311 | */ |
be1158cc TT |
312 | BUFFER_TRACE(bh, "queue"); |
313 | get_bh(bh); | |
314 | J_ASSERT_BH(bh, !buffer_jwrite(bh)); | |
315 | journal->j_chkpt_bhs[batch_count++] = bh; | |
316 | __buffer_relink_io(jh); | |
317 | transaction->t_chp_stats.cs_written++; | |
318 | if ((batch_count == JBD2_NR_BATCH) || | |
319 | need_resched() || | |
320 | spin_needbreak(&journal->j_list_lock)) | |
321 | goto unlock_and_flush; | |
470decc6 | 322 | } |
be1158cc TT |
323 | |
324 | if (batch_count) { | |
325 | unlock_and_flush: | |
326 | spin_unlock(&journal->j_list_lock); | |
327 | retry: | |
328 | if (batch_count) | |
329 | __flush_batch(journal, &batch_count); | |
330 | spin_lock(&journal->j_list_lock); | |
331 | goto restart; | |
332 | } | |
333 | ||
334 | /* | |
335 | * Now we issued all of the transaction's buffers, let's deal | |
336 | * with the buffers that are out for I/O. | |
337 | */ | |
88fe1acb TT |
338 | restart2: |
339 | /* Did somebody clean up the transaction in the meanwhile? */ | |
340 | if (journal->j_checkpoint_transactions != transaction || | |
341 | transaction->t_tid != this_tid) | |
342 | goto out; | |
343 | ||
dc6e8d66 | 344 | while (transaction->t_checkpoint_io_list) { |
88fe1acb TT |
345 | jh = transaction->t_checkpoint_io_list; |
346 | bh = jh2bh(jh); | |
88fe1acb | 347 | if (buffer_locked(bh)) { |
dc6e8d66 | 348 | get_bh(bh); |
ccd3c437 | 349 | spin_unlock(&journal->j_list_lock); |
88fe1acb TT |
350 | wait_on_buffer(bh); |
351 | /* the journal_head may have gone by now */ | |
352 | BUFFER_TRACE(bh, "brelse"); | |
353 | __brelse(bh); | |
354 | spin_lock(&journal->j_list_lock); | |
355 | goto restart2; | |
356 | } | |
357 | if (unlikely(buffer_write_io_error(bh)) && !result) | |
358 | result = -EIO; | |
359 | ||
360 | /* | |
361 | * Now in whatever state the buffer currently is, we | |
362 | * know that it has been written out and so we can | |
363 | * drop it from the list | |
364 | */ | |
dc6e8d66 TT |
365 | if (__jbd2_journal_remove_checkpoint(jh)) |
366 | break; | |
88fe1acb | 367 | } |
470decc6 DK |
368 | out: |
369 | spin_unlock(&journal->j_list_lock); | |
470decc6 | 370 | if (result < 0) |
44519faf HK |
371 | jbd2_journal_abort(journal, result); |
372 | else | |
373 | result = jbd2_cleanup_journal_tail(journal); | |
374 | ||
375 | return (result < 0) ? result : 0; | |
470decc6 DK |
376 | } |
377 | ||
378 | /* | |
379 | * Check the list of checkpoint transactions for the journal to see if | |
380 | * we have already got rid of any since the last update of the log tail | |
381 | * in the journal superblock. If so, we can instantly roll the | |
382 | * superblock forward to remove those transactions from the log. | |
383 | * | |
384 | * Return <0 on error, 0 on success, 1 if there was nothing to clean up. | |
385 | * | |
386 | * Called with the journal lock held. | |
387 | * | |
388 | * This is the only part of the journaling code which really needs to be | |
389 | * aware of transaction aborts. Checkpointing involves writing to the | |
390 | * main filesystem area rather than to the journal, so it can proceed | |
44519faf HK |
391 | * even in abort state, but we must not update the super block if |
392 | * checkpointing may have failed. Otherwise, we would lose some metadata | |
393 | * buffers which should be written-back to the filesystem. | |
470decc6 DK |
394 | */ |
395 | ||
f7f4bccb | 396 | int jbd2_cleanup_journal_tail(journal_t *journal) |
470decc6 | 397 | { |
470decc6 | 398 | tid_t first_tid; |
79feb521 | 399 | unsigned long blocknr; |
470decc6 | 400 | |
44519faf | 401 | if (is_journal_aborted(journal)) |
6f6a6fda | 402 | return -EIO; |
44519faf | 403 | |
79feb521 | 404 | if (!jbd2_journal_get_log_tail(journal, &first_tid, &blocknr)) |
470decc6 | 405 | return 1; |
79feb521 | 406 | J_ASSERT(blocknr != 0); |
cc3e1bea TT |
407 | |
408 | /* | |
79feb521 JK |
409 | * We need to make sure that any blocks that were recently written out |
410 | * --- perhaps by jbd2_log_do_checkpoint() --- are flushed out before | |
411 | * we drop the transactions from the journal. It's unlikely this will | |
412 | * be necessary, especially with an appropriately sized journal, but we | |
413 | * need this to guarantee correctness. Fortunately | |
414 | * jbd2_cleanup_journal_tail() doesn't get called all that often. | |
cc3e1bea | 415 | */ |
79feb521 | 416 | if (journal->j_flags & JBD2_BARRIER) |
b4f1afcd | 417 | blkdev_issue_flush(journal->j_fs_dev, GFP_NOFS, NULL); |
79feb521 | 418 | |
6f6a6fda | 419 | return __jbd2_update_log_tail(journal, first_tid, blocknr); |
470decc6 DK |
420 | } |
421 | ||
422 | ||
423 | /* Checkpoint list management */ | |
424 | ||
425 | /* | |
426 | * journal_clean_one_cp_list | |
427 | * | |
de1b7941 | 428 | * Find all the written-back checkpoint buffers in the given list and |
841df7df | 429 | * release them. If 'destroy' is set, clean all buffers unconditionally. |
470decc6 | 430 | * |
470decc6 | 431 | * Called with j_list_lock held. |
50849db3 | 432 | * Returns 1 if we freed the transaction, 0 otherwise. |
470decc6 | 433 | */ |
841df7df | 434 | static int journal_clean_one_cp_list(struct journal_head *jh, bool destroy) |
470decc6 DK |
435 | { |
436 | struct journal_head *last_jh; | |
437 | struct journal_head *next_jh = jh; | |
50849db3 | 438 | int ret; |
470decc6 | 439 | |
470decc6 DK |
440 | if (!jh) |
441 | return 0; | |
442 | ||
443 | last_jh = jh->b_cpprev; | |
444 | do { | |
445 | jh = next_jh; | |
446 | next_jh = jh->b_cpnext; | |
841df7df JK |
447 | if (!destroy) |
448 | ret = __try_to_free_cp_buf(jh); | |
449 | else | |
450 | ret = __jbd2_journal_remove_checkpoint(jh) + 1; | |
cc97f1a7 | 451 | if (!ret) |
33d14975 | 452 | return 0; |
50849db3 JK |
453 | if (ret == 2) |
454 | return 1; | |
470decc6 DK |
455 | /* |
456 | * This function only frees up some memory | |
457 | * if possible so we dont have an obligation | |
458 | * to finish processing. Bail out if preemption | |
459 | * requested: | |
460 | */ | |
461 | if (need_resched()) | |
33d14975 | 462 | return 0; |
470decc6 DK |
463 | } while (jh != last_jh); |
464 | ||
33d14975 | 465 | return 0; |
470decc6 DK |
466 | } |
467 | ||
468 | /* | |
469 | * journal_clean_checkpoint_list | |
470 | * | |
471 | * Find all the written-back checkpoint buffers in the journal and release them. | |
841df7df | 472 | * If 'destroy' is set, release all buffers unconditionally. |
470decc6 | 473 | * |
470decc6 | 474 | * Called with j_list_lock held. |
470decc6 | 475 | */ |
841df7df | 476 | void __jbd2_journal_clean_checkpoint_list(journal_t *journal, bool destroy) |
470decc6 DK |
477 | { |
478 | transaction_t *transaction, *last_transaction, *next_transaction; | |
cc97f1a7 | 479 | int ret; |
470decc6 DK |
480 | |
481 | transaction = journal->j_checkpoint_transactions; | |
482 | if (!transaction) | |
50849db3 | 483 | return; |
470decc6 DK |
484 | |
485 | last_transaction = transaction->t_cpprev; | |
486 | next_transaction = transaction; | |
487 | do { | |
488 | transaction = next_transaction; | |
489 | next_transaction = transaction->t_cpnext; | |
841df7df JK |
490 | ret = journal_clean_one_cp_list(transaction->t_checkpoint_list, |
491 | destroy); | |
470decc6 DK |
492 | /* |
493 | * This function only frees up some memory if possible so we | |
494 | * dont have an obligation to finish processing. Bail out if | |
495 | * preemption requested: | |
496 | */ | |
50849db3 JK |
497 | if (need_resched()) |
498 | return; | |
499 | if (ret) | |
470decc6 DK |
500 | continue; |
501 | /* | |
502 | * It is essential that we are as careful as in the case of | |
503 | * t_checkpoint_list with removing the buffer from the list as | |
504 | * we can possibly see not yet submitted buffers on io_list | |
505 | */ | |
50849db3 | 506 | ret = journal_clean_one_cp_list(transaction-> |
841df7df | 507 | t_checkpoint_io_list, destroy); |
50849db3 JK |
508 | if (need_resched()) |
509 | return; | |
510 | /* | |
511 | * Stop scanning if we couldn't free the transaction. This | |
512 | * avoids pointless scanning of transactions which still | |
513 | * weren't checkpointed. | |
514 | */ | |
515 | if (!ret) | |
516 | return; | |
470decc6 | 517 | } while (transaction != last_transaction); |
470decc6 DK |
518 | } |
519 | ||
841df7df JK |
520 | /* |
521 | * Remove buffers from all checkpoint lists as journal is aborted and we just | |
522 | * need to free memory | |
523 | */ | |
524 | void jbd2_journal_destroy_checkpoint(journal_t *journal) | |
525 | { | |
526 | /* | |
527 | * We loop because __jbd2_journal_clean_checkpoint_list() may abort | |
528 | * early due to a need of rescheduling. | |
529 | */ | |
530 | while (1) { | |
531 | spin_lock(&journal->j_list_lock); | |
532 | if (!journal->j_checkpoint_transactions) { | |
533 | spin_unlock(&journal->j_list_lock); | |
534 | break; | |
535 | } | |
536 | __jbd2_journal_clean_checkpoint_list(journal, true); | |
537 | spin_unlock(&journal->j_list_lock); | |
538 | cond_resched(); | |
539 | } | |
540 | } | |
541 | ||
470decc6 DK |
542 | /* |
543 | * journal_remove_checkpoint: called after a buffer has been committed | |
544 | * to disk (either by being write-back flushed to disk, or being | |
545 | * committed to the log). | |
546 | * | |
547 | * We cannot safely clean a transaction out of the log until all of the | |
548 | * buffer updates committed in that transaction have safely been stored | |
549 | * elsewhere on disk. To achieve this, all of the buffers in a | |
550 | * transaction need to be maintained on the transaction's checkpoint | |
551 | * lists until they have been rewritten, at which point this function is | |
552 | * called to remove the buffer from the existing transaction's | |
553 | * checkpoint lists. | |
554 | * | |
555 | * The function returns 1 if it frees the transaction, 0 otherwise. | |
de1b7941 | 556 | * The function can free jh and bh. |
470decc6 | 557 | * |
470decc6 | 558 | * This function is called with j_list_lock held. |
470decc6 | 559 | */ |
f7f4bccb | 560 | int __jbd2_journal_remove_checkpoint(struct journal_head *jh) |
470decc6 | 561 | { |
bf699327 | 562 | struct transaction_chp_stats_s *stats; |
470decc6 DK |
563 | transaction_t *transaction; |
564 | journal_t *journal; | |
565 | int ret = 0; | |
566 | ||
567 | JBUFFER_TRACE(jh, "entry"); | |
568 | ||
569 | if ((transaction = jh->b_cp_transaction) == NULL) { | |
570 | JBUFFER_TRACE(jh, "not on transaction"); | |
571 | goto out; | |
572 | } | |
573 | journal = transaction->t_journal; | |
574 | ||
de1b7941 | 575 | JBUFFER_TRACE(jh, "removing from transaction"); |
470decc6 DK |
576 | __buffer_unlink(jh); |
577 | jh->b_cp_transaction = NULL; | |
de1b7941 | 578 | jbd2_journal_put_journal_head(jh); |
470decc6 DK |
579 | |
580 | if (transaction->t_checkpoint_list != NULL || | |
581 | transaction->t_checkpoint_io_list != NULL) | |
582 | goto out; | |
470decc6 DK |
583 | |
584 | /* | |
585 | * There is one special case to worry about: if we have just pulled the | |
f5a7a6b0 JK |
586 | * buffer off a running or committing transaction's checkpoing list, |
587 | * then even if the checkpoint list is empty, the transaction obviously | |
588 | * cannot be dropped! | |
470decc6 | 589 | * |
f5a7a6b0 | 590 | * The locking here around t_state is a bit sleazy. |
f7f4bccb | 591 | * See the comment at the end of jbd2_journal_commit_transaction(). |
470decc6 | 592 | */ |
de1b7941 | 593 | if (transaction->t_state != T_FINISHED) |
470decc6 | 594 | goto out; |
470decc6 DK |
595 | |
596 | /* OK, that was the last buffer for the transaction: we can now | |
597 | safely remove this transaction from the log */ | |
bf699327 TT |
598 | stats = &transaction->t_chp_stats; |
599 | if (stats->cs_chp_time) | |
600 | stats->cs_chp_time = jbd2_time_diff(stats->cs_chp_time, | |
601 | jiffies); | |
602 | trace_jbd2_checkpoint_stats(journal->j_fs_dev->bd_dev, | |
603 | transaction->t_tid, stats); | |
470decc6 | 604 | |
f7f4bccb | 605 | __jbd2_journal_drop_transaction(journal, transaction); |
0c2022ec | 606 | jbd2_journal_free_transaction(transaction); |
470decc6 DK |
607 | ret = 1; |
608 | out: | |
470decc6 DK |
609 | return ret; |
610 | } | |
611 | ||
612 | /* | |
613 | * journal_insert_checkpoint: put a committed buffer onto a checkpoint | |
614 | * list so that we know when it is safe to clean the transaction out of | |
615 | * the log. | |
616 | * | |
617 | * Called with the journal locked. | |
618 | * Called with j_list_lock held. | |
619 | */ | |
f7f4bccb | 620 | void __jbd2_journal_insert_checkpoint(struct journal_head *jh, |
470decc6 DK |
621 | transaction_t *transaction) |
622 | { | |
623 | JBUFFER_TRACE(jh, "entry"); | |
624 | J_ASSERT_JH(jh, buffer_dirty(jh2bh(jh)) || buffer_jbddirty(jh2bh(jh))); | |
625 | J_ASSERT_JH(jh, jh->b_cp_transaction == NULL); | |
626 | ||
de1b7941 JK |
627 | /* Get reference for checkpointing transaction */ |
628 | jbd2_journal_grab_journal_head(jh2bh(jh)); | |
470decc6 DK |
629 | jh->b_cp_transaction = transaction; |
630 | ||
631 | if (!transaction->t_checkpoint_list) { | |
632 | jh->b_cpnext = jh->b_cpprev = jh; | |
633 | } else { | |
634 | jh->b_cpnext = transaction->t_checkpoint_list; | |
635 | jh->b_cpprev = transaction->t_checkpoint_list->b_cpprev; | |
636 | jh->b_cpprev->b_cpnext = jh; | |
637 | jh->b_cpnext->b_cpprev = jh; | |
638 | } | |
639 | transaction->t_checkpoint_list = jh; | |
640 | } | |
641 | ||
642 | /* | |
643 | * We've finished with this transaction structure: adios... | |
644 | * | |
645 | * The transaction must have no links except for the checkpoint by this | |
646 | * point. | |
647 | * | |
648 | * Called with the journal locked. | |
649 | * Called with j_list_lock held. | |
650 | */ | |
651 | ||
f7f4bccb | 652 | void __jbd2_journal_drop_transaction(journal_t *journal, transaction_t *transaction) |
470decc6 DK |
653 | { |
654 | assert_spin_locked(&journal->j_list_lock); | |
655 | if (transaction->t_cpnext) { | |
656 | transaction->t_cpnext->t_cpprev = transaction->t_cpprev; | |
657 | transaction->t_cpprev->t_cpnext = transaction->t_cpnext; | |
658 | if (journal->j_checkpoint_transactions == transaction) | |
659 | journal->j_checkpoint_transactions = | |
660 | transaction->t_cpnext; | |
661 | if (journal->j_checkpoint_transactions == transaction) | |
662 | journal->j_checkpoint_transactions = NULL; | |
663 | } | |
664 | ||
665 | J_ASSERT(transaction->t_state == T_FINISHED); | |
666 | J_ASSERT(transaction->t_buffers == NULL); | |
470decc6 | 667 | J_ASSERT(transaction->t_forget == NULL); |
470decc6 | 668 | J_ASSERT(transaction->t_shadow_list == NULL); |
470decc6 DK |
669 | J_ASSERT(transaction->t_checkpoint_list == NULL); |
670 | J_ASSERT(transaction->t_checkpoint_io_list == NULL); | |
a51dca9c | 671 | J_ASSERT(atomic_read(&transaction->t_updates) == 0); |
470decc6 DK |
672 | J_ASSERT(journal->j_committing_transaction != transaction); |
673 | J_ASSERT(journal->j_running_transaction != transaction); | |
674 | ||
2201c590 SA |
675 | trace_jbd2_drop_transaction(journal, transaction); |
676 | ||
470decc6 | 677 | jbd_debug(1, "Dropping transaction %d, all done\n", transaction->t_tid); |
470decc6 | 678 | } |