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470decc6 | 1 | /* |
f7f4bccb | 2 | * linux/fs/jbd2/commit.c |
470decc6 DK |
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 | * Journal commit routines for the generic filesystem journaling code; | |
13 | * part of the ext2fs journaling system. | |
14 | */ | |
15 | ||
16 | #include <linux/time.h> | |
17 | #include <linux/fs.h> | |
f7f4bccb | 18 | #include <linux/jbd2.h> |
470decc6 DK |
19 | #include <linux/errno.h> |
20 | #include <linux/slab.h> | |
21 | #include <linux/mm.h> | |
22 | #include <linux/pagemap.h> | |
8e85fb3f | 23 | #include <linux/jiffies.h> |
470decc6 DK |
24 | |
25 | /* | |
26 | * Default IO end handler for temporary BJ_IO buffer_heads. | |
27 | */ | |
28 | static void journal_end_buffer_io_sync(struct buffer_head *bh, int uptodate) | |
29 | { | |
30 | BUFFER_TRACE(bh, ""); | |
31 | if (uptodate) | |
32 | set_buffer_uptodate(bh); | |
33 | else | |
34 | clear_buffer_uptodate(bh); | |
35 | unlock_buffer(bh); | |
36 | } | |
37 | ||
38 | /* | |
39 | * When an ext3-ordered file is truncated, it is possible that many pages are | |
40 | * not sucessfully freed, because they are attached to a committing transaction. | |
41 | * After the transaction commits, these pages are left on the LRU, with no | |
42 | * ->mapping, and with attached buffers. These pages are trivially reclaimable | |
43 | * by the VM, but their apparent absence upsets the VM accounting, and it makes | |
44 | * the numbers in /proc/meminfo look odd. | |
45 | * | |
46 | * So here, we have a buffer which has just come off the forget list. Look to | |
47 | * see if we can strip all buffers from the backing page. | |
48 | * | |
49 | * Called under lock_journal(), and possibly under journal_datalist_lock. The | |
50 | * caller provided us with a ref against the buffer, and we drop that here. | |
51 | */ | |
52 | static void release_buffer_page(struct buffer_head *bh) | |
53 | { | |
54 | struct page *page; | |
55 | ||
56 | if (buffer_dirty(bh)) | |
57 | goto nope; | |
58 | if (atomic_read(&bh->b_count) != 1) | |
59 | goto nope; | |
60 | page = bh->b_page; | |
61 | if (!page) | |
62 | goto nope; | |
63 | if (page->mapping) | |
64 | goto nope; | |
65 | ||
66 | /* OK, it's a truncated page */ | |
67 | if (TestSetPageLocked(page)) | |
68 | goto nope; | |
69 | ||
70 | page_cache_get(page); | |
71 | __brelse(bh); | |
72 | try_to_free_buffers(page); | |
73 | unlock_page(page); | |
74 | page_cache_release(page); | |
75 | return; | |
76 | ||
77 | nope: | |
78 | __brelse(bh); | |
79 | } | |
80 | ||
81 | /* | |
82 | * Try to acquire jbd_lock_bh_state() against the buffer, when j_list_lock is | |
83 | * held. For ranking reasons we must trylock. If we lose, schedule away and | |
84 | * return 0. j_list_lock is dropped in this case. | |
85 | */ | |
86 | static int inverted_lock(journal_t *journal, struct buffer_head *bh) | |
87 | { | |
88 | if (!jbd_trylock_bh_state(bh)) { | |
89 | spin_unlock(&journal->j_list_lock); | |
90 | schedule(); | |
91 | return 0; | |
92 | } | |
93 | return 1; | |
94 | } | |
95 | ||
96 | /* Done it all: now write the commit record. We should have | |
97 | * cleaned up our previous buffers by now, so if we are in abort | |
98 | * mode we can now just skip the rest of the journal write | |
99 | * entirely. | |
100 | * | |
101 | * Returns 1 if the journal needs to be aborted or 0 on success | |
102 | */ | |
103 | static int journal_write_commit_record(journal_t *journal, | |
104 | transaction_t *commit_transaction) | |
105 | { | |
106 | struct journal_head *descriptor; | |
107 | struct buffer_head *bh; | |
108 | int i, ret; | |
109 | int barrier_done = 0; | |
110 | ||
111 | if (is_journal_aborted(journal)) | |
112 | return 0; | |
113 | ||
f7f4bccb | 114 | descriptor = jbd2_journal_get_descriptor_buffer(journal); |
470decc6 DK |
115 | if (!descriptor) |
116 | return 1; | |
117 | ||
118 | bh = jh2bh(descriptor); | |
119 | ||
120 | /* AKPM: buglet - add `i' to tmp! */ | |
121 | for (i = 0; i < bh->b_size; i += 512) { | |
122 | journal_header_t *tmp = (journal_header_t*)bh->b_data; | |
f7f4bccb MC |
123 | tmp->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER); |
124 | tmp->h_blocktype = cpu_to_be32(JBD2_COMMIT_BLOCK); | |
470decc6 DK |
125 | tmp->h_sequence = cpu_to_be32(commit_transaction->t_tid); |
126 | } | |
127 | ||
128 | JBUFFER_TRACE(descriptor, "write commit block"); | |
129 | set_buffer_dirty(bh); | |
f7f4bccb | 130 | if (journal->j_flags & JBD2_BARRIER) { |
470decc6 DK |
131 | set_buffer_ordered(bh); |
132 | barrier_done = 1; | |
133 | } | |
134 | ret = sync_dirty_buffer(bh); | |
135 | /* is it possible for another commit to fail at roughly | |
136 | * the same time as this one? If so, we don't want to | |
137 | * trust the barrier flag in the super, but instead want | |
138 | * to remember if we sent a barrier request | |
139 | */ | |
140 | if (ret == -EOPNOTSUPP && barrier_done) { | |
141 | char b[BDEVNAME_SIZE]; | |
142 | ||
143 | printk(KERN_WARNING | |
144 | "JBD: barrier-based sync failed on %s - " | |
145 | "disabling barriers\n", | |
146 | bdevname(journal->j_dev, b)); | |
147 | spin_lock(&journal->j_state_lock); | |
f7f4bccb | 148 | journal->j_flags &= ~JBD2_BARRIER; |
470decc6 DK |
149 | spin_unlock(&journal->j_state_lock); |
150 | ||
151 | /* And try again, without the barrier */ | |
152 | clear_buffer_ordered(bh); | |
153 | set_buffer_uptodate(bh); | |
154 | set_buffer_dirty(bh); | |
155 | ret = sync_dirty_buffer(bh); | |
156 | } | |
157 | put_bh(bh); /* One for getblk() */ | |
f7f4bccb | 158 | jbd2_journal_put_journal_head(descriptor); |
470decc6 DK |
159 | |
160 | return (ret == -EIO); | |
161 | } | |
162 | ||
163 | static void journal_do_submit_data(struct buffer_head **wbuf, int bufs) | |
164 | { | |
165 | int i; | |
166 | ||
167 | for (i = 0; i < bufs; i++) { | |
168 | wbuf[i]->b_end_io = end_buffer_write_sync; | |
169 | /* We use-up our safety reference in submit_bh() */ | |
170 | submit_bh(WRITE, wbuf[i]); | |
171 | } | |
172 | } | |
173 | ||
174 | /* | |
175 | * Submit all the data buffers to disk | |
176 | */ | |
177 | static void journal_submit_data_buffers(journal_t *journal, | |
178 | transaction_t *commit_transaction) | |
179 | { | |
180 | struct journal_head *jh; | |
181 | struct buffer_head *bh; | |
182 | int locked; | |
183 | int bufs = 0; | |
184 | struct buffer_head **wbuf = journal->j_wbuf; | |
185 | ||
186 | /* | |
187 | * Whenever we unlock the journal and sleep, things can get added | |
188 | * onto ->t_sync_datalist, so we have to keep looping back to | |
189 | * write_out_data until we *know* that the list is empty. | |
190 | * | |
191 | * Cleanup any flushed data buffers from the data list. Even in | |
192 | * abort mode, we want to flush this out as soon as possible. | |
193 | */ | |
194 | write_out_data: | |
195 | cond_resched(); | |
196 | spin_lock(&journal->j_list_lock); | |
197 | ||
198 | while (commit_transaction->t_sync_datalist) { | |
199 | jh = commit_transaction->t_sync_datalist; | |
200 | bh = jh2bh(jh); | |
201 | locked = 0; | |
202 | ||
203 | /* Get reference just to make sure buffer does not disappear | |
204 | * when we are forced to drop various locks */ | |
205 | get_bh(bh); | |
206 | /* If the buffer is dirty, we need to submit IO and hence | |
207 | * we need the buffer lock. We try to lock the buffer without | |
208 | * blocking. If we fail, we need to drop j_list_lock and do | |
209 | * blocking lock_buffer(). | |
210 | */ | |
211 | if (buffer_dirty(bh)) { | |
212 | if (test_set_buffer_locked(bh)) { | |
213 | BUFFER_TRACE(bh, "needs blocking lock"); | |
214 | spin_unlock(&journal->j_list_lock); | |
215 | /* Write out all data to prevent deadlocks */ | |
216 | journal_do_submit_data(wbuf, bufs); | |
217 | bufs = 0; | |
218 | lock_buffer(bh); | |
219 | spin_lock(&journal->j_list_lock); | |
220 | } | |
221 | locked = 1; | |
222 | } | |
223 | /* We have to get bh_state lock. Again out of order, sigh. */ | |
224 | if (!inverted_lock(journal, bh)) { | |
225 | jbd_lock_bh_state(bh); | |
226 | spin_lock(&journal->j_list_lock); | |
227 | } | |
228 | /* Someone already cleaned up the buffer? */ | |
229 | if (!buffer_jbd(bh) | |
230 | || jh->b_transaction != commit_transaction | |
231 | || jh->b_jlist != BJ_SyncData) { | |
232 | jbd_unlock_bh_state(bh); | |
233 | if (locked) | |
234 | unlock_buffer(bh); | |
235 | BUFFER_TRACE(bh, "already cleaned up"); | |
236 | put_bh(bh); | |
237 | continue; | |
238 | } | |
239 | if (locked && test_clear_buffer_dirty(bh)) { | |
240 | BUFFER_TRACE(bh, "needs writeout, adding to array"); | |
241 | wbuf[bufs++] = bh; | |
f7f4bccb | 242 | __jbd2_journal_file_buffer(jh, commit_transaction, |
470decc6 DK |
243 | BJ_Locked); |
244 | jbd_unlock_bh_state(bh); | |
245 | if (bufs == journal->j_wbufsize) { | |
246 | spin_unlock(&journal->j_list_lock); | |
247 | journal_do_submit_data(wbuf, bufs); | |
248 | bufs = 0; | |
249 | goto write_out_data; | |
250 | } | |
12603925 HH |
251 | } else if (!locked && buffer_locked(bh)) { |
252 | __jbd2_journal_file_buffer(jh, commit_transaction, | |
253 | BJ_Locked); | |
254 | jbd_unlock_bh_state(bh); | |
255 | put_bh(bh); | |
256 | } else { | |
470decc6 | 257 | BUFFER_TRACE(bh, "writeout complete: unfile"); |
f7f4bccb | 258 | __jbd2_journal_unfile_buffer(jh); |
470decc6 DK |
259 | jbd_unlock_bh_state(bh); |
260 | if (locked) | |
261 | unlock_buffer(bh); | |
f7f4bccb | 262 | jbd2_journal_remove_journal_head(bh); |
470decc6 | 263 | /* Once for our safety reference, once for |
f7f4bccb | 264 | * jbd2_journal_remove_journal_head() */ |
470decc6 DK |
265 | put_bh(bh); |
266 | put_bh(bh); | |
267 | } | |
268 | ||
269 | if (lock_need_resched(&journal->j_list_lock)) { | |
270 | spin_unlock(&journal->j_list_lock); | |
271 | goto write_out_data; | |
272 | } | |
273 | } | |
274 | spin_unlock(&journal->j_list_lock); | |
275 | journal_do_submit_data(wbuf, bufs); | |
276 | } | |
277 | ||
b517bea1 | 278 | static inline void write_tag_block(int tag_bytes, journal_block_tag_t *tag, |
18eba7aa | 279 | unsigned long long block) |
b517bea1 ZB |
280 | { |
281 | tag->t_blocknr = cpu_to_be32(block & (u32)~0); | |
cd02ff0b | 282 | if (tag_bytes > JBD2_TAG_SIZE32) |
b517bea1 ZB |
283 | tag->t_blocknr_high = cpu_to_be32((block >> 31) >> 1); |
284 | } | |
285 | ||
470decc6 | 286 | /* |
f7f4bccb | 287 | * jbd2_journal_commit_transaction |
470decc6 DK |
288 | * |
289 | * The primary function for committing a transaction to the log. This | |
290 | * function is called by the journal thread to begin a complete commit. | |
291 | */ | |
f7f4bccb | 292 | void jbd2_journal_commit_transaction(journal_t *journal) |
470decc6 | 293 | { |
8e85fb3f | 294 | struct transaction_stats_s stats; |
470decc6 DK |
295 | transaction_t *commit_transaction; |
296 | struct journal_head *jh, *new_jh, *descriptor; | |
297 | struct buffer_head **wbuf = journal->j_wbuf; | |
298 | int bufs; | |
299 | int flags; | |
300 | int err; | |
18eba7aa | 301 | unsigned long long blocknr; |
470decc6 DK |
302 | char *tagp = NULL; |
303 | journal_header_t *header; | |
304 | journal_block_tag_t *tag = NULL; | |
305 | int space_left = 0; | |
306 | int first_tag = 0; | |
307 | int tag_flag; | |
308 | int i; | |
b517bea1 | 309 | int tag_bytes = journal_tag_bytes(journal); |
470decc6 DK |
310 | |
311 | /* | |
312 | * First job: lock down the current transaction and wait for | |
313 | * all outstanding updates to complete. | |
314 | */ | |
315 | ||
316 | #ifdef COMMIT_STATS | |
317 | spin_lock(&journal->j_list_lock); | |
318 | summarise_journal_usage(journal); | |
319 | spin_unlock(&journal->j_list_lock); | |
320 | #endif | |
321 | ||
f7f4bccb MC |
322 | /* Do we need to erase the effects of a prior jbd2_journal_flush? */ |
323 | if (journal->j_flags & JBD2_FLUSHED) { | |
470decc6 | 324 | jbd_debug(3, "super block updated\n"); |
f7f4bccb | 325 | jbd2_journal_update_superblock(journal, 1); |
470decc6 DK |
326 | } else { |
327 | jbd_debug(3, "superblock not updated\n"); | |
328 | } | |
329 | ||
330 | J_ASSERT(journal->j_running_transaction != NULL); | |
331 | J_ASSERT(journal->j_committing_transaction == NULL); | |
332 | ||
333 | commit_transaction = journal->j_running_transaction; | |
334 | J_ASSERT(commit_transaction->t_state == T_RUNNING); | |
335 | ||
336 | jbd_debug(1, "JBD: starting commit of transaction %d\n", | |
337 | commit_transaction->t_tid); | |
338 | ||
339 | spin_lock(&journal->j_state_lock); | |
340 | commit_transaction->t_state = T_LOCKED; | |
341 | ||
8e85fb3f JL |
342 | stats.u.run.rs_wait = commit_transaction->t_max_wait; |
343 | stats.u.run.rs_locked = jiffies; | |
344 | stats.u.run.rs_running = jbd2_time_diff(commit_transaction->t_start, | |
345 | stats.u.run.rs_locked); | |
346 | ||
470decc6 DK |
347 | spin_lock(&commit_transaction->t_handle_lock); |
348 | while (commit_transaction->t_updates) { | |
349 | DEFINE_WAIT(wait); | |
350 | ||
351 | prepare_to_wait(&journal->j_wait_updates, &wait, | |
352 | TASK_UNINTERRUPTIBLE); | |
353 | if (commit_transaction->t_updates) { | |
354 | spin_unlock(&commit_transaction->t_handle_lock); | |
355 | spin_unlock(&journal->j_state_lock); | |
356 | schedule(); | |
357 | spin_lock(&journal->j_state_lock); | |
358 | spin_lock(&commit_transaction->t_handle_lock); | |
359 | } | |
360 | finish_wait(&journal->j_wait_updates, &wait); | |
361 | } | |
362 | spin_unlock(&commit_transaction->t_handle_lock); | |
363 | ||
364 | J_ASSERT (commit_transaction->t_outstanding_credits <= | |
365 | journal->j_max_transaction_buffers); | |
366 | ||
367 | /* | |
368 | * First thing we are allowed to do is to discard any remaining | |
369 | * BJ_Reserved buffers. Note, it is _not_ permissible to assume | |
370 | * that there are no such buffers: if a large filesystem | |
371 | * operation like a truncate needs to split itself over multiple | |
f7f4bccb | 372 | * transactions, then it may try to do a jbd2_journal_restart() while |
470decc6 DK |
373 | * there are still BJ_Reserved buffers outstanding. These must |
374 | * be released cleanly from the current transaction. | |
375 | * | |
376 | * In this case, the filesystem must still reserve write access | |
377 | * again before modifying the buffer in the new transaction, but | |
378 | * we do not require it to remember exactly which old buffers it | |
379 | * has reserved. This is consistent with the existing behaviour | |
f7f4bccb | 380 | * that multiple jbd2_journal_get_write_access() calls to the same |
470decc6 DK |
381 | * buffer are perfectly permissable. |
382 | */ | |
383 | while (commit_transaction->t_reserved_list) { | |
384 | jh = commit_transaction->t_reserved_list; | |
385 | JBUFFER_TRACE(jh, "reserved, unused: refile"); | |
386 | /* | |
f7f4bccb | 387 | * A jbd2_journal_get_undo_access()+jbd2_journal_release_buffer() may |
470decc6 DK |
388 | * leave undo-committed data. |
389 | */ | |
390 | if (jh->b_committed_data) { | |
391 | struct buffer_head *bh = jh2bh(jh); | |
392 | ||
393 | jbd_lock_bh_state(bh); | |
af1e76d6 | 394 | jbd2_free(jh->b_committed_data, bh->b_size); |
470decc6 DK |
395 | jh->b_committed_data = NULL; |
396 | jbd_unlock_bh_state(bh); | |
397 | } | |
f7f4bccb | 398 | jbd2_journal_refile_buffer(journal, jh); |
470decc6 DK |
399 | } |
400 | ||
401 | /* | |
402 | * Now try to drop any written-back buffers from the journal's | |
403 | * checkpoint lists. We do this *before* commit because it potentially | |
404 | * frees some memory | |
405 | */ | |
406 | spin_lock(&journal->j_list_lock); | |
f7f4bccb | 407 | __jbd2_journal_clean_checkpoint_list(journal); |
470decc6 DK |
408 | spin_unlock(&journal->j_list_lock); |
409 | ||
410 | jbd_debug (3, "JBD: commit phase 1\n"); | |
411 | ||
412 | /* | |
413 | * Switch to a new revoke table. | |
414 | */ | |
f7f4bccb | 415 | jbd2_journal_switch_revoke_table(journal); |
470decc6 | 416 | |
8e85fb3f JL |
417 | stats.u.run.rs_flushing = jiffies; |
418 | stats.u.run.rs_locked = jbd2_time_diff(stats.u.run.rs_locked, | |
419 | stats.u.run.rs_flushing); | |
420 | ||
470decc6 DK |
421 | commit_transaction->t_state = T_FLUSH; |
422 | journal->j_committing_transaction = commit_transaction; | |
423 | journal->j_running_transaction = NULL; | |
424 | commit_transaction->t_log_start = journal->j_head; | |
425 | wake_up(&journal->j_wait_transaction_locked); | |
426 | spin_unlock(&journal->j_state_lock); | |
427 | ||
428 | jbd_debug (3, "JBD: commit phase 2\n"); | |
429 | ||
430 | /* | |
431 | * First, drop modified flag: all accesses to the buffers | |
432 | * will be tracked for a new trasaction only -bzzz | |
433 | */ | |
434 | spin_lock(&journal->j_list_lock); | |
435 | if (commit_transaction->t_buffers) { | |
436 | new_jh = jh = commit_transaction->t_buffers->b_tnext; | |
437 | do { | |
438 | J_ASSERT_JH(new_jh, new_jh->b_modified == 1 || | |
439 | new_jh->b_modified == 0); | |
440 | new_jh->b_modified = 0; | |
441 | new_jh = new_jh->b_tnext; | |
442 | } while (new_jh != jh); | |
443 | } | |
444 | spin_unlock(&journal->j_list_lock); | |
445 | ||
446 | /* | |
447 | * Now start flushing things to disk, in the order they appear | |
448 | * on the transaction lists. Data blocks go first. | |
449 | */ | |
450 | err = 0; | |
451 | journal_submit_data_buffers(journal, commit_transaction); | |
452 | ||
453 | /* | |
454 | * Wait for all previously submitted IO to complete. | |
455 | */ | |
456 | spin_lock(&journal->j_list_lock); | |
457 | while (commit_transaction->t_locked_list) { | |
458 | struct buffer_head *bh; | |
459 | ||
460 | jh = commit_transaction->t_locked_list->b_tprev; | |
461 | bh = jh2bh(jh); | |
462 | get_bh(bh); | |
463 | if (buffer_locked(bh)) { | |
464 | spin_unlock(&journal->j_list_lock); | |
465 | wait_on_buffer(bh); | |
466 | if (unlikely(!buffer_uptodate(bh))) | |
467 | err = -EIO; | |
468 | spin_lock(&journal->j_list_lock); | |
469 | } | |
470 | if (!inverted_lock(journal, bh)) { | |
471 | put_bh(bh); | |
472 | spin_lock(&journal->j_list_lock); | |
473 | continue; | |
474 | } | |
475 | if (buffer_jbd(bh) && jh->b_jlist == BJ_Locked) { | |
f7f4bccb | 476 | __jbd2_journal_unfile_buffer(jh); |
470decc6 | 477 | jbd_unlock_bh_state(bh); |
f7f4bccb | 478 | jbd2_journal_remove_journal_head(bh); |
470decc6 DK |
479 | put_bh(bh); |
480 | } else { | |
481 | jbd_unlock_bh_state(bh); | |
482 | } | |
483 | put_bh(bh); | |
484 | cond_resched_lock(&journal->j_list_lock); | |
485 | } | |
486 | spin_unlock(&journal->j_list_lock); | |
487 | ||
488 | if (err) | |
a7fa2baf | 489 | jbd2_journal_abort(journal, err); |
470decc6 | 490 | |
f7f4bccb | 491 | jbd2_journal_write_revoke_records(journal, commit_transaction); |
470decc6 DK |
492 | |
493 | jbd_debug(3, "JBD: commit phase 2\n"); | |
494 | ||
495 | /* | |
496 | * If we found any dirty or locked buffers, then we should have | |
497 | * looped back up to the write_out_data label. If there weren't | |
498 | * any then journal_clean_data_list should have wiped the list | |
499 | * clean by now, so check that it is in fact empty. | |
500 | */ | |
501 | J_ASSERT (commit_transaction->t_sync_datalist == NULL); | |
502 | ||
503 | jbd_debug (3, "JBD: commit phase 3\n"); | |
504 | ||
505 | /* | |
506 | * Way to go: we have now written out all of the data for a | |
507 | * transaction! Now comes the tricky part: we need to write out | |
508 | * metadata. Loop over the transaction's entire buffer list: | |
509 | */ | |
510 | commit_transaction->t_state = T_COMMIT; | |
511 | ||
8e85fb3f JL |
512 | stats.u.run.rs_logging = jiffies; |
513 | stats.u.run.rs_flushing = jbd2_time_diff(stats.u.run.rs_flushing, | |
514 | stats.u.run.rs_logging); | |
515 | stats.u.run.rs_blocks = commit_transaction->t_outstanding_credits; | |
516 | stats.u.run.rs_blocks_logged = 0; | |
517 | ||
470decc6 DK |
518 | descriptor = NULL; |
519 | bufs = 0; | |
520 | while (commit_transaction->t_buffers) { | |
521 | ||
522 | /* Find the next buffer to be journaled... */ | |
523 | ||
524 | jh = commit_transaction->t_buffers; | |
525 | ||
526 | /* If we're in abort mode, we just un-journal the buffer and | |
527 | release it for background writing. */ | |
528 | ||
529 | if (is_journal_aborted(journal)) { | |
530 | JBUFFER_TRACE(jh, "journal is aborting: refile"); | |
f7f4bccb | 531 | jbd2_journal_refile_buffer(journal, jh); |
470decc6 DK |
532 | /* If that was the last one, we need to clean up |
533 | * any descriptor buffers which may have been | |
534 | * already allocated, even if we are now | |
535 | * aborting. */ | |
536 | if (!commit_transaction->t_buffers) | |
537 | goto start_journal_io; | |
538 | continue; | |
539 | } | |
540 | ||
541 | /* Make sure we have a descriptor block in which to | |
542 | record the metadata buffer. */ | |
543 | ||
544 | if (!descriptor) { | |
545 | struct buffer_head *bh; | |
546 | ||
547 | J_ASSERT (bufs == 0); | |
548 | ||
549 | jbd_debug(4, "JBD: get descriptor\n"); | |
550 | ||
f7f4bccb | 551 | descriptor = jbd2_journal_get_descriptor_buffer(journal); |
470decc6 | 552 | if (!descriptor) { |
a7fa2baf | 553 | jbd2_journal_abort(journal, -EIO); |
470decc6 DK |
554 | continue; |
555 | } | |
556 | ||
557 | bh = jh2bh(descriptor); | |
558 | jbd_debug(4, "JBD: got buffer %llu (%p)\n", | |
559 | (unsigned long long)bh->b_blocknr, bh->b_data); | |
560 | header = (journal_header_t *)&bh->b_data[0]; | |
f7f4bccb MC |
561 | header->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER); |
562 | header->h_blocktype = cpu_to_be32(JBD2_DESCRIPTOR_BLOCK); | |
470decc6 DK |
563 | header->h_sequence = cpu_to_be32(commit_transaction->t_tid); |
564 | ||
565 | tagp = &bh->b_data[sizeof(journal_header_t)]; | |
566 | space_left = bh->b_size - sizeof(journal_header_t); | |
567 | first_tag = 1; | |
568 | set_buffer_jwrite(bh); | |
569 | set_buffer_dirty(bh); | |
570 | wbuf[bufs++] = bh; | |
571 | ||
572 | /* Record it so that we can wait for IO | |
573 | completion later */ | |
574 | BUFFER_TRACE(bh, "ph3: file as descriptor"); | |
f7f4bccb | 575 | jbd2_journal_file_buffer(descriptor, commit_transaction, |
470decc6 DK |
576 | BJ_LogCtl); |
577 | } | |
578 | ||
579 | /* Where is the buffer to be written? */ | |
580 | ||
f7f4bccb | 581 | err = jbd2_journal_next_log_block(journal, &blocknr); |
470decc6 DK |
582 | /* If the block mapping failed, just abandon the buffer |
583 | and repeat this loop: we'll fall into the | |
584 | refile-on-abort condition above. */ | |
585 | if (err) { | |
a7fa2baf | 586 | jbd2_journal_abort(journal, err); |
470decc6 DK |
587 | continue; |
588 | } | |
589 | ||
590 | /* | |
591 | * start_this_handle() uses t_outstanding_credits to determine | |
592 | * the free space in the log, but this counter is changed | |
f7f4bccb | 593 | * by jbd2_journal_next_log_block() also. |
470decc6 DK |
594 | */ |
595 | commit_transaction->t_outstanding_credits--; | |
596 | ||
597 | /* Bump b_count to prevent truncate from stumbling over | |
598 | the shadowed buffer! @@@ This can go if we ever get | |
599 | rid of the BJ_IO/BJ_Shadow pairing of buffers. */ | |
600 | atomic_inc(&jh2bh(jh)->b_count); | |
601 | ||
602 | /* Make a temporary IO buffer with which to write it out | |
603 | (this will requeue both the metadata buffer and the | |
604 | temporary IO buffer). new_bh goes on BJ_IO*/ | |
605 | ||
606 | set_bit(BH_JWrite, &jh2bh(jh)->b_state); | |
607 | /* | |
f7f4bccb | 608 | * akpm: jbd2_journal_write_metadata_buffer() sets |
470decc6 DK |
609 | * new_bh->b_transaction to commit_transaction. |
610 | * We need to clean this up before we release new_bh | |
611 | * (which is of type BJ_IO) | |
612 | */ | |
613 | JBUFFER_TRACE(jh, "ph3: write metadata"); | |
f7f4bccb | 614 | flags = jbd2_journal_write_metadata_buffer(commit_transaction, |
470decc6 DK |
615 | jh, &new_jh, blocknr); |
616 | set_bit(BH_JWrite, &jh2bh(new_jh)->b_state); | |
617 | wbuf[bufs++] = jh2bh(new_jh); | |
618 | ||
619 | /* Record the new block's tag in the current descriptor | |
620 | buffer */ | |
621 | ||
622 | tag_flag = 0; | |
623 | if (flags & 1) | |
f7f4bccb | 624 | tag_flag |= JBD2_FLAG_ESCAPE; |
470decc6 | 625 | if (!first_tag) |
f7f4bccb | 626 | tag_flag |= JBD2_FLAG_SAME_UUID; |
470decc6 DK |
627 | |
628 | tag = (journal_block_tag_t *) tagp; | |
b517bea1 | 629 | write_tag_block(tag_bytes, tag, jh2bh(jh)->b_blocknr); |
470decc6 | 630 | tag->t_flags = cpu_to_be32(tag_flag); |
b517bea1 ZB |
631 | tagp += tag_bytes; |
632 | space_left -= tag_bytes; | |
470decc6 DK |
633 | |
634 | if (first_tag) { | |
635 | memcpy (tagp, journal->j_uuid, 16); | |
636 | tagp += 16; | |
637 | space_left -= 16; | |
638 | first_tag = 0; | |
639 | } | |
640 | ||
641 | /* If there's no more to do, or if the descriptor is full, | |
642 | let the IO rip! */ | |
643 | ||
644 | if (bufs == journal->j_wbufsize || | |
645 | commit_transaction->t_buffers == NULL || | |
b517bea1 | 646 | space_left < tag_bytes + 16) { |
470decc6 DK |
647 | |
648 | jbd_debug(4, "JBD: Submit %d IOs\n", bufs); | |
649 | ||
650 | /* Write an end-of-descriptor marker before | |
651 | submitting the IOs. "tag" still points to | |
652 | the last tag we set up. */ | |
653 | ||
f7f4bccb | 654 | tag->t_flags |= cpu_to_be32(JBD2_FLAG_LAST_TAG); |
470decc6 DK |
655 | |
656 | start_journal_io: | |
657 | for (i = 0; i < bufs; i++) { | |
658 | struct buffer_head *bh = wbuf[i]; | |
659 | lock_buffer(bh); | |
660 | clear_buffer_dirty(bh); | |
661 | set_buffer_uptodate(bh); | |
662 | bh->b_end_io = journal_end_buffer_io_sync; | |
663 | submit_bh(WRITE, bh); | |
664 | } | |
665 | cond_resched(); | |
8e85fb3f | 666 | stats.u.run.rs_blocks_logged += bufs; |
470decc6 DK |
667 | |
668 | /* Force a new descriptor to be generated next | |
669 | time round the loop. */ | |
670 | descriptor = NULL; | |
671 | bufs = 0; | |
672 | } | |
673 | } | |
674 | ||
675 | /* Lo and behold: we have just managed to send a transaction to | |
676 | the log. Before we can commit it, wait for the IO so far to | |
677 | complete. Control buffers being written are on the | |
678 | transaction's t_log_list queue, and metadata buffers are on | |
679 | the t_iobuf_list queue. | |
680 | ||
681 | Wait for the buffers in reverse order. That way we are | |
682 | less likely to be woken up until all IOs have completed, and | |
683 | so we incur less scheduling load. | |
684 | */ | |
685 | ||
686 | jbd_debug(3, "JBD: commit phase 4\n"); | |
687 | ||
688 | /* | |
689 | * akpm: these are BJ_IO, and j_list_lock is not needed. | |
690 | * See __journal_try_to_free_buffer. | |
691 | */ | |
692 | wait_for_iobuf: | |
693 | while (commit_transaction->t_iobuf_list != NULL) { | |
694 | struct buffer_head *bh; | |
695 | ||
696 | jh = commit_transaction->t_iobuf_list->b_tprev; | |
697 | bh = jh2bh(jh); | |
698 | if (buffer_locked(bh)) { | |
699 | wait_on_buffer(bh); | |
700 | goto wait_for_iobuf; | |
701 | } | |
702 | if (cond_resched()) | |
703 | goto wait_for_iobuf; | |
704 | ||
705 | if (unlikely(!buffer_uptodate(bh))) | |
706 | err = -EIO; | |
707 | ||
708 | clear_buffer_jwrite(bh); | |
709 | ||
710 | JBUFFER_TRACE(jh, "ph4: unfile after journal write"); | |
f7f4bccb | 711 | jbd2_journal_unfile_buffer(journal, jh); |
470decc6 DK |
712 | |
713 | /* | |
714 | * ->t_iobuf_list should contain only dummy buffer_heads | |
f7f4bccb | 715 | * which were created by jbd2_journal_write_metadata_buffer(). |
470decc6 DK |
716 | */ |
717 | BUFFER_TRACE(bh, "dumping temporary bh"); | |
f7f4bccb | 718 | jbd2_journal_put_journal_head(jh); |
470decc6 DK |
719 | __brelse(bh); |
720 | J_ASSERT_BH(bh, atomic_read(&bh->b_count) == 0); | |
721 | free_buffer_head(bh); | |
722 | ||
723 | /* We also have to unlock and free the corresponding | |
724 | shadowed buffer */ | |
725 | jh = commit_transaction->t_shadow_list->b_tprev; | |
726 | bh = jh2bh(jh); | |
727 | clear_bit(BH_JWrite, &bh->b_state); | |
728 | J_ASSERT_BH(bh, buffer_jbddirty(bh)); | |
729 | ||
730 | /* The metadata is now released for reuse, but we need | |
731 | to remember it against this transaction so that when | |
732 | we finally commit, we can do any checkpointing | |
733 | required. */ | |
734 | JBUFFER_TRACE(jh, "file as BJ_Forget"); | |
f7f4bccb | 735 | jbd2_journal_file_buffer(jh, commit_transaction, BJ_Forget); |
470decc6 DK |
736 | /* Wake up any transactions which were waiting for this |
737 | IO to complete */ | |
738 | wake_up_bit(&bh->b_state, BH_Unshadow); | |
739 | JBUFFER_TRACE(jh, "brelse shadowed buffer"); | |
740 | __brelse(bh); | |
741 | } | |
742 | ||
743 | J_ASSERT (commit_transaction->t_shadow_list == NULL); | |
744 | ||
745 | jbd_debug(3, "JBD: commit phase 5\n"); | |
746 | ||
747 | /* Here we wait for the revoke record and descriptor record buffers */ | |
748 | wait_for_ctlbuf: | |
749 | while (commit_transaction->t_log_list != NULL) { | |
750 | struct buffer_head *bh; | |
751 | ||
752 | jh = commit_transaction->t_log_list->b_tprev; | |
753 | bh = jh2bh(jh); | |
754 | if (buffer_locked(bh)) { | |
755 | wait_on_buffer(bh); | |
756 | goto wait_for_ctlbuf; | |
757 | } | |
758 | if (cond_resched()) | |
759 | goto wait_for_ctlbuf; | |
760 | ||
761 | if (unlikely(!buffer_uptodate(bh))) | |
762 | err = -EIO; | |
763 | ||
764 | BUFFER_TRACE(bh, "ph5: control buffer writeout done: unfile"); | |
765 | clear_buffer_jwrite(bh); | |
f7f4bccb MC |
766 | jbd2_journal_unfile_buffer(journal, jh); |
767 | jbd2_journal_put_journal_head(jh); | |
470decc6 DK |
768 | __brelse(bh); /* One for getblk */ |
769 | /* AKPM: bforget here */ | |
770 | } | |
771 | ||
772 | jbd_debug(3, "JBD: commit phase 6\n"); | |
773 | ||
774 | if (journal_write_commit_record(journal, commit_transaction)) | |
775 | err = -EIO; | |
776 | ||
777 | if (err) | |
a7fa2baf | 778 | jbd2_journal_abort(journal, err); |
470decc6 DK |
779 | |
780 | /* End of a transaction! Finally, we can do checkpoint | |
781 | processing: any buffers committed as a result of this | |
782 | transaction can be removed from any checkpoint list it was on | |
783 | before. */ | |
784 | ||
785 | jbd_debug(3, "JBD: commit phase 7\n"); | |
786 | ||
787 | J_ASSERT(commit_transaction->t_sync_datalist == NULL); | |
788 | J_ASSERT(commit_transaction->t_buffers == NULL); | |
789 | J_ASSERT(commit_transaction->t_checkpoint_list == NULL); | |
790 | J_ASSERT(commit_transaction->t_iobuf_list == NULL); | |
791 | J_ASSERT(commit_transaction->t_shadow_list == NULL); | |
792 | J_ASSERT(commit_transaction->t_log_list == NULL); | |
793 | ||
794 | restart_loop: | |
795 | /* | |
796 | * As there are other places (journal_unmap_buffer()) adding buffers | |
797 | * to this list we have to be careful and hold the j_list_lock. | |
798 | */ | |
799 | spin_lock(&journal->j_list_lock); | |
800 | while (commit_transaction->t_forget) { | |
801 | transaction_t *cp_transaction; | |
802 | struct buffer_head *bh; | |
803 | ||
804 | jh = commit_transaction->t_forget; | |
805 | spin_unlock(&journal->j_list_lock); | |
806 | bh = jh2bh(jh); | |
807 | jbd_lock_bh_state(bh); | |
808 | J_ASSERT_JH(jh, jh->b_transaction == commit_transaction || | |
809 | jh->b_transaction == journal->j_running_transaction); | |
810 | ||
811 | /* | |
812 | * If there is undo-protected committed data against | |
813 | * this buffer, then we can remove it now. If it is a | |
814 | * buffer needing such protection, the old frozen_data | |
815 | * field now points to a committed version of the | |
816 | * buffer, so rotate that field to the new committed | |
817 | * data. | |
818 | * | |
819 | * Otherwise, we can just throw away the frozen data now. | |
820 | */ | |
821 | if (jh->b_committed_data) { | |
af1e76d6 | 822 | jbd2_free(jh->b_committed_data, bh->b_size); |
470decc6 DK |
823 | jh->b_committed_data = NULL; |
824 | if (jh->b_frozen_data) { | |
825 | jh->b_committed_data = jh->b_frozen_data; | |
826 | jh->b_frozen_data = NULL; | |
827 | } | |
828 | } else if (jh->b_frozen_data) { | |
af1e76d6 | 829 | jbd2_free(jh->b_frozen_data, bh->b_size); |
470decc6 DK |
830 | jh->b_frozen_data = NULL; |
831 | } | |
832 | ||
833 | spin_lock(&journal->j_list_lock); | |
834 | cp_transaction = jh->b_cp_transaction; | |
835 | if (cp_transaction) { | |
836 | JBUFFER_TRACE(jh, "remove from old cp transaction"); | |
8e85fb3f | 837 | cp_transaction->t_chp_stats.cs_dropped++; |
f7f4bccb | 838 | __jbd2_journal_remove_checkpoint(jh); |
470decc6 DK |
839 | } |
840 | ||
841 | /* Only re-checkpoint the buffer_head if it is marked | |
842 | * dirty. If the buffer was added to the BJ_Forget list | |
f7f4bccb | 843 | * by jbd2_journal_forget, it may no longer be dirty and |
470decc6 DK |
844 | * there's no point in keeping a checkpoint record for |
845 | * it. */ | |
846 | ||
847 | /* A buffer which has been freed while still being | |
848 | * journaled by a previous transaction may end up still | |
849 | * being dirty here, but we want to avoid writing back | |
850 | * that buffer in the future now that the last use has | |
851 | * been committed. That's not only a performance gain, | |
852 | * it also stops aliasing problems if the buffer is left | |
853 | * behind for writeback and gets reallocated for another | |
854 | * use in a different page. */ | |
855 | if (buffer_freed(bh)) { | |
856 | clear_buffer_freed(bh); | |
857 | clear_buffer_jbddirty(bh); | |
858 | } | |
859 | ||
860 | if (buffer_jbddirty(bh)) { | |
861 | JBUFFER_TRACE(jh, "add to new checkpointing trans"); | |
f7f4bccb | 862 | __jbd2_journal_insert_checkpoint(jh, commit_transaction); |
470decc6 | 863 | JBUFFER_TRACE(jh, "refile for checkpoint writeback"); |
f7f4bccb | 864 | __jbd2_journal_refile_buffer(jh); |
470decc6 DK |
865 | jbd_unlock_bh_state(bh); |
866 | } else { | |
867 | J_ASSERT_BH(bh, !buffer_dirty(bh)); | |
868 | /* The buffer on BJ_Forget list and not jbddirty means | |
869 | * it has been freed by this transaction and hence it | |
870 | * could not have been reallocated until this | |
871 | * transaction has committed. *BUT* it could be | |
872 | * reallocated once we have written all the data to | |
873 | * disk and before we process the buffer on BJ_Forget | |
874 | * list. */ | |
875 | JBUFFER_TRACE(jh, "refile or unfile freed buffer"); | |
f7f4bccb | 876 | __jbd2_journal_refile_buffer(jh); |
470decc6 DK |
877 | if (!jh->b_transaction) { |
878 | jbd_unlock_bh_state(bh); | |
879 | /* needs a brelse */ | |
f7f4bccb | 880 | jbd2_journal_remove_journal_head(bh); |
470decc6 DK |
881 | release_buffer_page(bh); |
882 | } else | |
883 | jbd_unlock_bh_state(bh); | |
884 | } | |
885 | cond_resched_lock(&journal->j_list_lock); | |
886 | } | |
887 | spin_unlock(&journal->j_list_lock); | |
888 | /* | |
f5a7a6b0 JK |
889 | * This is a bit sleazy. We use j_list_lock to protect transition |
890 | * of a transaction into T_FINISHED state and calling | |
891 | * __jbd2_journal_drop_transaction(). Otherwise we could race with | |
892 | * other checkpointing code processing the transaction... | |
470decc6 DK |
893 | */ |
894 | spin_lock(&journal->j_state_lock); | |
895 | spin_lock(&journal->j_list_lock); | |
896 | /* | |
897 | * Now recheck if some buffers did not get attached to the transaction | |
898 | * while the lock was dropped... | |
899 | */ | |
900 | if (commit_transaction->t_forget) { | |
901 | spin_unlock(&journal->j_list_lock); | |
902 | spin_unlock(&journal->j_state_lock); | |
903 | goto restart_loop; | |
904 | } | |
905 | ||
906 | /* Done with this transaction! */ | |
907 | ||
908 | jbd_debug(3, "JBD: commit phase 8\n"); | |
909 | ||
910 | J_ASSERT(commit_transaction->t_state == T_COMMIT); | |
911 | ||
8e85fb3f JL |
912 | commit_transaction->t_start = jiffies; |
913 | stats.u.run.rs_logging = jbd2_time_diff(stats.u.run.rs_logging, | |
914 | commit_transaction->t_start); | |
915 | ||
916 | /* | |
917 | * File the transaction for history | |
918 | */ | |
919 | stats.ts_type = JBD2_STATS_RUN; | |
920 | stats.ts_tid = commit_transaction->t_tid; | |
921 | stats.u.run.rs_handle_count = commit_transaction->t_handle_count; | |
922 | spin_lock(&journal->j_history_lock); | |
923 | memcpy(journal->j_history + journal->j_history_cur, &stats, | |
924 | sizeof(stats)); | |
925 | if (++journal->j_history_cur == journal->j_history_max) | |
926 | journal->j_history_cur = 0; | |
927 | ||
928 | /* | |
929 | * Calculate overall stats | |
930 | */ | |
931 | journal->j_stats.ts_tid++; | |
932 | journal->j_stats.u.run.rs_wait += stats.u.run.rs_wait; | |
933 | journal->j_stats.u.run.rs_running += stats.u.run.rs_running; | |
934 | journal->j_stats.u.run.rs_locked += stats.u.run.rs_locked; | |
935 | journal->j_stats.u.run.rs_flushing += stats.u.run.rs_flushing; | |
936 | journal->j_stats.u.run.rs_logging += stats.u.run.rs_logging; | |
937 | journal->j_stats.u.run.rs_handle_count += stats.u.run.rs_handle_count; | |
938 | journal->j_stats.u.run.rs_blocks += stats.u.run.rs_blocks; | |
939 | journal->j_stats.u.run.rs_blocks_logged += stats.u.run.rs_blocks_logged; | |
940 | spin_unlock(&journal->j_history_lock); | |
941 | ||
470decc6 DK |
942 | commit_transaction->t_state = T_FINISHED; |
943 | J_ASSERT(commit_transaction == journal->j_committing_transaction); | |
944 | journal->j_commit_sequence = commit_transaction->t_tid; | |
945 | journal->j_committing_transaction = NULL; | |
946 | spin_unlock(&journal->j_state_lock); | |
947 | ||
f89b7795 JK |
948 | if (commit_transaction->t_checkpoint_list == NULL && |
949 | commit_transaction->t_checkpoint_io_list == NULL) { | |
f7f4bccb | 950 | __jbd2_journal_drop_transaction(journal, commit_transaction); |
470decc6 DK |
951 | } else { |
952 | if (journal->j_checkpoint_transactions == NULL) { | |
953 | journal->j_checkpoint_transactions = commit_transaction; | |
954 | commit_transaction->t_cpnext = commit_transaction; | |
955 | commit_transaction->t_cpprev = commit_transaction; | |
956 | } else { | |
957 | commit_transaction->t_cpnext = | |
958 | journal->j_checkpoint_transactions; | |
959 | commit_transaction->t_cpprev = | |
960 | commit_transaction->t_cpnext->t_cpprev; | |
961 | commit_transaction->t_cpnext->t_cpprev = | |
962 | commit_transaction; | |
963 | commit_transaction->t_cpprev->t_cpnext = | |
964 | commit_transaction; | |
965 | } | |
966 | } | |
967 | spin_unlock(&journal->j_list_lock); | |
968 | ||
969 | jbd_debug(1, "JBD: commit %d complete, head %d\n", | |
970 | journal->j_commit_sequence, journal->j_tail_sequence); | |
971 | ||
972 | wake_up(&journal->j_wait_done_commit); | |
973 | } |