Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
f30c2269 | 2 | * linux/fs/jbd/commit.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 | * 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> | |
18 | #include <linux/jbd.h> | |
19 | #include <linux/errno.h> | |
20 | #include <linux/slab.h> | |
21 | #include <linux/mm.h> | |
22 | #include <linux/pagemap.h> | |
512a0043 | 23 | #include <linux/bio.h> |
1da177e4 LT |
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 | |
fc80c442 | 40 | * not successfully freed, because they are attached to a committing transaction. |
1da177e4 LT |
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 | * | |
fc80c442 TO |
49 | * Called under journal->j_list_lock. The caller provided us with a ref |
50 | * against the buffer, and we drop that here. | |
1da177e4 LT |
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 */ | |
529ae9aa | 67 | if (!trylock_page(page)) |
1da177e4 LT |
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 | ||
fc80c442 TO |
81 | /* |
82 | * Decrement reference counter for data buffer. If it has been marked | |
83 | * 'BH_Freed', release it and the page to which it belongs if possible. | |
84 | */ | |
85 | static void release_data_buffer(struct buffer_head *bh) | |
86 | { | |
87 | if (buffer_freed(bh)) { | |
88 | clear_buffer_freed(bh); | |
89 | release_buffer_page(bh); | |
90 | } else | |
91 | put_bh(bh); | |
92 | } | |
93 | ||
1da177e4 LT |
94 | /* |
95 | * Try to acquire jbd_lock_bh_state() against the buffer, when j_list_lock is | |
96 | * held. For ranking reasons we must trylock. If we lose, schedule away and | |
97 | * return 0. j_list_lock is dropped in this case. | |
98 | */ | |
99 | static int inverted_lock(journal_t *journal, struct buffer_head *bh) | |
100 | { | |
101 | if (!jbd_trylock_bh_state(bh)) { | |
102 | spin_unlock(&journal->j_list_lock); | |
103 | schedule(); | |
104 | return 0; | |
105 | } | |
106 | return 1; | |
107 | } | |
108 | ||
109 | /* Done it all: now write the commit record. We should have | |
110 | * cleaned up our previous buffers by now, so if we are in abort | |
111 | * mode we can now just skip the rest of the journal write | |
112 | * entirely. | |
113 | * | |
114 | * Returns 1 if the journal needs to be aborted or 0 on success | |
115 | */ | |
116 | static int journal_write_commit_record(journal_t *journal, | |
117 | transaction_t *commit_transaction) | |
118 | { | |
119 | struct journal_head *descriptor; | |
120 | struct buffer_head *bh; | |
5315217e JK |
121 | journal_header_t *header; |
122 | int ret; | |
1da177e4 LT |
123 | int barrier_done = 0; |
124 | ||
125 | if (is_journal_aborted(journal)) | |
126 | return 0; | |
127 | ||
128 | descriptor = journal_get_descriptor_buffer(journal); | |
129 | if (!descriptor) | |
130 | return 1; | |
131 | ||
132 | bh = jh2bh(descriptor); | |
133 | ||
5315217e JK |
134 | header = (journal_header_t *)(bh->b_data); |
135 | header->h_magic = cpu_to_be32(JFS_MAGIC_NUMBER); | |
136 | header->h_blocktype = cpu_to_be32(JFS_COMMIT_BLOCK); | |
137 | header->h_sequence = cpu_to_be32(commit_transaction->t_tid); | |
1da177e4 LT |
138 | |
139 | JBUFFER_TRACE(descriptor, "write commit block"); | |
140 | set_buffer_dirty(bh); | |
141 | if (journal->j_flags & JFS_BARRIER) { | |
142 | set_buffer_ordered(bh); | |
143 | barrier_done = 1; | |
144 | } | |
145 | ret = sync_dirty_buffer(bh); | |
28ae094c NB |
146 | if (barrier_done) |
147 | clear_buffer_ordered(bh); | |
1da177e4 LT |
148 | /* is it possible for another commit to fail at roughly |
149 | * the same time as this one? If so, we don't want to | |
150 | * trust the barrier flag in the super, but instead want | |
151 | * to remember if we sent a barrier request | |
152 | */ | |
153 | if (ret == -EOPNOTSUPP && barrier_done) { | |
154 | char b[BDEVNAME_SIZE]; | |
155 | ||
156 | printk(KERN_WARNING | |
157 | "JBD: barrier-based sync failed on %s - " | |
158 | "disabling barriers\n", | |
159 | bdevname(journal->j_dev, b)); | |
160 | spin_lock(&journal->j_state_lock); | |
161 | journal->j_flags &= ~JFS_BARRIER; | |
162 | spin_unlock(&journal->j_state_lock); | |
163 | ||
164 | /* And try again, without the barrier */ | |
1da177e4 LT |
165 | set_buffer_uptodate(bh); |
166 | set_buffer_dirty(bh); | |
167 | ret = sync_dirty_buffer(bh); | |
168 | } | |
169 | put_bh(bh); /* One for getblk() */ | |
170 | journal_put_journal_head(descriptor); | |
171 | ||
172 | return (ret == -EIO); | |
173 | } | |
174 | ||
512a0043 TT |
175 | static void journal_do_submit_data(struct buffer_head **wbuf, int bufs, |
176 | int write_op) | |
3998b930 JK |
177 | { |
178 | int i; | |
179 | ||
180 | for (i = 0; i < bufs; i++) { | |
181 | wbuf[i]->b_end_io = end_buffer_write_sync; | |
182 | /* We use-up our safety reference in submit_bh() */ | |
512a0043 | 183 | submit_bh(write_op, wbuf[i]); |
3998b930 JK |
184 | } |
185 | } | |
186 | ||
187 | /* | |
188 | * Submit all the data buffers to disk | |
189 | */ | |
cbe5f466 | 190 | static int journal_submit_data_buffers(journal_t *journal, |
512a0043 TT |
191 | transaction_t *commit_transaction, |
192 | int write_op) | |
3998b930 JK |
193 | { |
194 | struct journal_head *jh; | |
195 | struct buffer_head *bh; | |
196 | int locked; | |
197 | int bufs = 0; | |
198 | struct buffer_head **wbuf = journal->j_wbuf; | |
cbe5f466 | 199 | int err = 0; |
3998b930 JK |
200 | |
201 | /* | |
202 | * Whenever we unlock the journal and sleep, things can get added | |
203 | * onto ->t_sync_datalist, so we have to keep looping back to | |
204 | * write_out_data until we *know* that the list is empty. | |
205 | * | |
206 | * Cleanup any flushed data buffers from the data list. Even in | |
207 | * abort mode, we want to flush this out as soon as possible. | |
208 | */ | |
209 | write_out_data: | |
210 | cond_resched(); | |
211 | spin_lock(&journal->j_list_lock); | |
212 | ||
213 | while (commit_transaction->t_sync_datalist) { | |
214 | jh = commit_transaction->t_sync_datalist; | |
215 | bh = jh2bh(jh); | |
216 | locked = 0; | |
217 | ||
218 | /* Get reference just to make sure buffer does not disappear | |
219 | * when we are forced to drop various locks */ | |
220 | get_bh(bh); | |
221 | /* If the buffer is dirty, we need to submit IO and hence | |
222 | * we need the buffer lock. We try to lock the buffer without | |
223 | * blocking. If we fail, we need to drop j_list_lock and do | |
224 | * blocking lock_buffer(). | |
225 | */ | |
226 | if (buffer_dirty(bh)) { | |
ca5de404 | 227 | if (!trylock_buffer(bh)) { |
3998b930 JK |
228 | BUFFER_TRACE(bh, "needs blocking lock"); |
229 | spin_unlock(&journal->j_list_lock); | |
230 | /* Write out all data to prevent deadlocks */ | |
512a0043 | 231 | journal_do_submit_data(wbuf, bufs, write_op); |
3998b930 JK |
232 | bufs = 0; |
233 | lock_buffer(bh); | |
234 | spin_lock(&journal->j_list_lock); | |
235 | } | |
236 | locked = 1; | |
237 | } | |
238 | /* We have to get bh_state lock. Again out of order, sigh. */ | |
239 | if (!inverted_lock(journal, bh)) { | |
240 | jbd_lock_bh_state(bh); | |
241 | spin_lock(&journal->j_list_lock); | |
242 | } | |
243 | /* Someone already cleaned up the buffer? */ | |
a61d90d7 | 244 | if (!buffer_jbd(bh) || bh2jh(bh) != jh |
3998b930 JK |
245 | || jh->b_transaction != commit_transaction |
246 | || jh->b_jlist != BJ_SyncData) { | |
247 | jbd_unlock_bh_state(bh); | |
248 | if (locked) | |
249 | unlock_buffer(bh); | |
250 | BUFFER_TRACE(bh, "already cleaned up"); | |
fc80c442 | 251 | release_data_buffer(bh); |
3998b930 JK |
252 | continue; |
253 | } | |
254 | if (locked && test_clear_buffer_dirty(bh)) { | |
255 | BUFFER_TRACE(bh, "needs writeout, adding to array"); | |
256 | wbuf[bufs++] = bh; | |
257 | __journal_file_buffer(jh, commit_transaction, | |
258 | BJ_Locked); | |
259 | jbd_unlock_bh_state(bh); | |
260 | if (bufs == journal->j_wbufsize) { | |
261 | spin_unlock(&journal->j_list_lock); | |
512a0043 | 262 | journal_do_submit_data(wbuf, bufs, write_op); |
3998b930 JK |
263 | bufs = 0; |
264 | goto write_out_data; | |
265 | } | |
6f5a9da1 HH |
266 | } else if (!locked && buffer_locked(bh)) { |
267 | __journal_file_buffer(jh, commit_transaction, | |
268 | BJ_Locked); | |
269 | jbd_unlock_bh_state(bh); | |
270 | put_bh(bh); | |
271 | } else { | |
3998b930 | 272 | BUFFER_TRACE(bh, "writeout complete: unfile"); |
cbe5f466 HK |
273 | if (unlikely(!buffer_uptodate(bh))) |
274 | err = -EIO; | |
3998b930 JK |
275 | __journal_unfile_buffer(jh); |
276 | jbd_unlock_bh_state(bh); | |
277 | if (locked) | |
278 | unlock_buffer(bh); | |
279 | journal_remove_journal_head(bh); | |
fc80c442 | 280 | /* One for our safety reference, other for |
3998b930 JK |
281 | * journal_remove_journal_head() */ |
282 | put_bh(bh); | |
fc80c442 | 283 | release_data_buffer(bh); |
3998b930 JK |
284 | } |
285 | ||
95c354fe | 286 | if (need_resched() || spin_needbreak(&journal->j_list_lock)) { |
3998b930 JK |
287 | spin_unlock(&journal->j_list_lock); |
288 | goto write_out_data; | |
289 | } | |
290 | } | |
291 | spin_unlock(&journal->j_list_lock); | |
512a0043 | 292 | journal_do_submit_data(wbuf, bufs, write_op); |
cbe5f466 HK |
293 | |
294 | return err; | |
3998b930 JK |
295 | } |
296 | ||
1da177e4 LT |
297 | /* |
298 | * journal_commit_transaction | |
299 | * | |
300 | * The primary function for committing a transaction to the log. This | |
301 | * function is called by the journal thread to begin a complete commit. | |
302 | */ | |
303 | void journal_commit_transaction(journal_t *journal) | |
304 | { | |
305 | transaction_t *commit_transaction; | |
306 | struct journal_head *jh, *new_jh, *descriptor; | |
307 | struct buffer_head **wbuf = journal->j_wbuf; | |
308 | int bufs; | |
309 | int flags; | |
310 | int err; | |
9c28cbcc | 311 | unsigned int blocknr; |
f420d4dc JB |
312 | ktime_t start_time; |
313 | u64 commit_time; | |
1da177e4 LT |
314 | char *tagp = NULL; |
315 | journal_header_t *header; | |
316 | journal_block_tag_t *tag = NULL; | |
317 | int space_left = 0; | |
318 | int first_tag = 0; | |
319 | int tag_flag; | |
320 | int i; | |
512a0043 | 321 | int write_op = WRITE; |
1da177e4 LT |
322 | |
323 | /* | |
324 | * First job: lock down the current transaction and wait for | |
325 | * all outstanding updates to complete. | |
326 | */ | |
327 | ||
328 | #ifdef COMMIT_STATS | |
329 | spin_lock(&journal->j_list_lock); | |
330 | summarise_journal_usage(journal); | |
331 | spin_unlock(&journal->j_list_lock); | |
332 | #endif | |
333 | ||
334 | /* Do we need to erase the effects of a prior journal_flush? */ | |
335 | if (journal->j_flags & JFS_FLUSHED) { | |
336 | jbd_debug(3, "super block updated\n"); | |
337 | journal_update_superblock(journal, 1); | |
338 | } else { | |
339 | jbd_debug(3, "superblock not updated\n"); | |
340 | } | |
341 | ||
342 | J_ASSERT(journal->j_running_transaction != NULL); | |
343 | J_ASSERT(journal->j_committing_transaction == NULL); | |
344 | ||
345 | commit_transaction = journal->j_running_transaction; | |
346 | J_ASSERT(commit_transaction->t_state == T_RUNNING); | |
347 | ||
348 | jbd_debug(1, "JBD: starting commit of transaction %d\n", | |
349 | commit_transaction->t_tid); | |
350 | ||
351 | spin_lock(&journal->j_state_lock); | |
352 | commit_transaction->t_state = T_LOCKED; | |
353 | ||
6c4bac6b JA |
354 | /* |
355 | * Use plugged writes here, since we want to submit several before | |
356 | * we unplug the device. We don't do explicit unplugging in here, | |
357 | * instead we rely on sync_buffer() doing the unplug for us. | |
358 | */ | |
512a0043 | 359 | if (commit_transaction->t_synchronous_commit) |
6c4bac6b | 360 | write_op = WRITE_SYNC_PLUG; |
1da177e4 LT |
361 | spin_lock(&commit_transaction->t_handle_lock); |
362 | while (commit_transaction->t_updates) { | |
363 | DEFINE_WAIT(wait); | |
364 | ||
365 | prepare_to_wait(&journal->j_wait_updates, &wait, | |
366 | TASK_UNINTERRUPTIBLE); | |
367 | if (commit_transaction->t_updates) { | |
368 | spin_unlock(&commit_transaction->t_handle_lock); | |
369 | spin_unlock(&journal->j_state_lock); | |
370 | schedule(); | |
371 | spin_lock(&journal->j_state_lock); | |
372 | spin_lock(&commit_transaction->t_handle_lock); | |
373 | } | |
374 | finish_wait(&journal->j_wait_updates, &wait); | |
375 | } | |
376 | spin_unlock(&commit_transaction->t_handle_lock); | |
377 | ||
378 | J_ASSERT (commit_transaction->t_outstanding_credits <= | |
379 | journal->j_max_transaction_buffers); | |
380 | ||
381 | /* | |
382 | * First thing we are allowed to do is to discard any remaining | |
383 | * BJ_Reserved buffers. Note, it is _not_ permissible to assume | |
384 | * that there are no such buffers: if a large filesystem | |
385 | * operation like a truncate needs to split itself over multiple | |
386 | * transactions, then it may try to do a journal_restart() while | |
387 | * there are still BJ_Reserved buffers outstanding. These must | |
388 | * be released cleanly from the current transaction. | |
389 | * | |
390 | * In this case, the filesystem must still reserve write access | |
391 | * again before modifying the buffer in the new transaction, but | |
392 | * we do not require it to remember exactly which old buffers it | |
393 | * has reserved. This is consistent with the existing behaviour | |
394 | * that multiple journal_get_write_access() calls to the same | |
395 | * buffer are perfectly permissable. | |
396 | */ | |
397 | while (commit_transaction->t_reserved_list) { | |
398 | jh = commit_transaction->t_reserved_list; | |
399 | JBUFFER_TRACE(jh, "reserved, unused: refile"); | |
400 | /* | |
401 | * A journal_get_undo_access()+journal_release_buffer() may | |
402 | * leave undo-committed data. | |
403 | */ | |
404 | if (jh->b_committed_data) { | |
405 | struct buffer_head *bh = jh2bh(jh); | |
406 | ||
407 | jbd_lock_bh_state(bh); | |
c089d490 | 408 | jbd_free(jh->b_committed_data, bh->b_size); |
f99d49ad | 409 | jh->b_committed_data = NULL; |
1da177e4 LT |
410 | jbd_unlock_bh_state(bh); |
411 | } | |
412 | journal_refile_buffer(journal, jh); | |
413 | } | |
414 | ||
415 | /* | |
416 | * Now try to drop any written-back buffers from the journal's | |
417 | * checkpoint lists. We do this *before* commit because it potentially | |
418 | * frees some memory | |
419 | */ | |
420 | spin_lock(&journal->j_list_lock); | |
421 | __journal_clean_checkpoint_list(journal); | |
422 | spin_unlock(&journal->j_list_lock); | |
423 | ||
424 | jbd_debug (3, "JBD: commit phase 1\n"); | |
425 | ||
426 | /* | |
427 | * Switch to a new revoke table. | |
428 | */ | |
429 | journal_switch_revoke_table(journal); | |
430 | ||
431 | commit_transaction->t_state = T_FLUSH; | |
432 | journal->j_committing_transaction = commit_transaction; | |
433 | journal->j_running_transaction = NULL; | |
f420d4dc | 434 | start_time = ktime_get(); |
1da177e4 LT |
435 | commit_transaction->t_log_start = journal->j_head; |
436 | wake_up(&journal->j_wait_transaction_locked); | |
437 | spin_unlock(&journal->j_state_lock); | |
438 | ||
439 | jbd_debug (3, "JBD: commit phase 2\n"); | |
440 | ||
1da177e4 LT |
441 | /* |
442 | * Now start flushing things to disk, in the order they appear | |
443 | * on the transaction lists. Data blocks go first. | |
444 | */ | |
512a0043 TT |
445 | err = journal_submit_data_buffers(journal, commit_transaction, |
446 | write_op); | |
1da177e4 LT |
447 | |
448 | /* | |
449 | * Wait for all previously submitted IO to complete. | |
450 | */ | |
3998b930 | 451 | spin_lock(&journal->j_list_lock); |
1da177e4 LT |
452 | while (commit_transaction->t_locked_list) { |
453 | struct buffer_head *bh; | |
454 | ||
455 | jh = commit_transaction->t_locked_list->b_tprev; | |
456 | bh = jh2bh(jh); | |
457 | get_bh(bh); | |
458 | if (buffer_locked(bh)) { | |
459 | spin_unlock(&journal->j_list_lock); | |
460 | wait_on_buffer(bh); | |
1da177e4 LT |
461 | spin_lock(&journal->j_list_lock); |
462 | } | |
cbe5f466 | 463 | if (unlikely(!buffer_uptodate(bh))) { |
529ae9aa | 464 | if (!trylock_page(bh->b_page)) { |
cbe5f466 HK |
465 | spin_unlock(&journal->j_list_lock); |
466 | lock_page(bh->b_page); | |
467 | spin_lock(&journal->j_list_lock); | |
468 | } | |
469 | if (bh->b_page->mapping) | |
470 | set_bit(AS_EIO, &bh->b_page->mapping->flags); | |
471 | ||
472 | unlock_page(bh->b_page); | |
473 | SetPageError(bh->b_page); | |
474 | err = -EIO; | |
475 | } | |
1da177e4 LT |
476 | if (!inverted_lock(journal, bh)) { |
477 | put_bh(bh); | |
478 | spin_lock(&journal->j_list_lock); | |
479 | continue; | |
480 | } | |
a61d90d7 JK |
481 | if (buffer_jbd(bh) && bh2jh(bh) == jh && |
482 | jh->b_transaction == commit_transaction && | |
483 | jh->b_jlist == BJ_Locked) { | |
1da177e4 LT |
484 | __journal_unfile_buffer(jh); |
485 | jbd_unlock_bh_state(bh); | |
486 | journal_remove_journal_head(bh); | |
487 | put_bh(bh); | |
488 | } else { | |
489 | jbd_unlock_bh_state(bh); | |
490 | } | |
fc80c442 | 491 | release_data_buffer(bh); |
1da177e4 LT |
492 | cond_resched_lock(&journal->j_list_lock); |
493 | } | |
494 | spin_unlock(&journal->j_list_lock); | |
495 | ||
cbe5f466 HK |
496 | if (err) { |
497 | char b[BDEVNAME_SIZE]; | |
498 | ||
499 | printk(KERN_WARNING | |
500 | "JBD: Detected IO errors while flushing file data " | |
501 | "on %s\n", bdevname(journal->j_fs_dev, b)); | |
0e4fb5e2 HK |
502 | if (journal->j_flags & JFS_ABORT_ON_SYNCDATA_ERR) |
503 | journal_abort(journal, err); | |
cbe5f466 HK |
504 | err = 0; |
505 | } | |
1da177e4 | 506 | |
38d726d1 | 507 | journal_write_revoke_records(journal, commit_transaction, write_op); |
1da177e4 | 508 | |
1da177e4 LT |
509 | /* |
510 | * If we found any dirty or locked buffers, then we should have | |
511 | * looped back up to the write_out_data label. If there weren't | |
512 | * any then journal_clean_data_list should have wiped the list | |
513 | * clean by now, so check that it is in fact empty. | |
514 | */ | |
515 | J_ASSERT (commit_transaction->t_sync_datalist == NULL); | |
516 | ||
517 | jbd_debug (3, "JBD: commit phase 3\n"); | |
518 | ||
519 | /* | |
520 | * Way to go: we have now written out all of the data for a | |
521 | * transaction! Now comes the tricky part: we need to write out | |
522 | * metadata. Loop over the transaction's entire buffer list: | |
523 | */ | |
772279c5 | 524 | spin_lock(&journal->j_state_lock); |
1da177e4 | 525 | commit_transaction->t_state = T_COMMIT; |
772279c5 | 526 | spin_unlock(&journal->j_state_lock); |
1da177e4 | 527 | |
5b9a499d JB |
528 | J_ASSERT(commit_transaction->t_nr_buffers <= |
529 | commit_transaction->t_outstanding_credits); | |
530 | ||
1da177e4 LT |
531 | descriptor = NULL; |
532 | bufs = 0; | |
533 | while (commit_transaction->t_buffers) { | |
534 | ||
535 | /* Find the next buffer to be journaled... */ | |
536 | ||
537 | jh = commit_transaction->t_buffers; | |
538 | ||
539 | /* If we're in abort mode, we just un-journal the buffer and | |
885e353c | 540 | release it. */ |
1da177e4 LT |
541 | |
542 | if (is_journal_aborted(journal)) { | |
885e353c | 543 | clear_buffer_jbddirty(jh2bh(jh)); |
1da177e4 LT |
544 | JBUFFER_TRACE(jh, "journal is aborting: refile"); |
545 | journal_refile_buffer(journal, jh); | |
546 | /* If that was the last one, we need to clean up | |
547 | * any descriptor buffers which may have been | |
548 | * already allocated, even if we are now | |
549 | * aborting. */ | |
550 | if (!commit_transaction->t_buffers) | |
551 | goto start_journal_io; | |
552 | continue; | |
553 | } | |
554 | ||
555 | /* Make sure we have a descriptor block in which to | |
556 | record the metadata buffer. */ | |
557 | ||
558 | if (!descriptor) { | |
559 | struct buffer_head *bh; | |
560 | ||
561 | J_ASSERT (bufs == 0); | |
562 | ||
563 | jbd_debug(4, "JBD: get descriptor\n"); | |
564 | ||
565 | descriptor = journal_get_descriptor_buffer(journal); | |
566 | if (!descriptor) { | |
7a266e75 | 567 | journal_abort(journal, -EIO); |
1da177e4 LT |
568 | continue; |
569 | } | |
570 | ||
571 | bh = jh2bh(descriptor); | |
572 | jbd_debug(4, "JBD: got buffer %llu (%p)\n", | |
573 | (unsigned long long)bh->b_blocknr, bh->b_data); | |
574 | header = (journal_header_t *)&bh->b_data[0]; | |
575 | header->h_magic = cpu_to_be32(JFS_MAGIC_NUMBER); | |
576 | header->h_blocktype = cpu_to_be32(JFS_DESCRIPTOR_BLOCK); | |
577 | header->h_sequence = cpu_to_be32(commit_transaction->t_tid); | |
578 | ||
579 | tagp = &bh->b_data[sizeof(journal_header_t)]; | |
580 | space_left = bh->b_size - sizeof(journal_header_t); | |
581 | first_tag = 1; | |
582 | set_buffer_jwrite(bh); | |
583 | set_buffer_dirty(bh); | |
584 | wbuf[bufs++] = bh; | |
585 | ||
586 | /* Record it so that we can wait for IO | |
587 | completion later */ | |
588 | BUFFER_TRACE(bh, "ph3: file as descriptor"); | |
589 | journal_file_buffer(descriptor, commit_transaction, | |
590 | BJ_LogCtl); | |
591 | } | |
592 | ||
593 | /* Where is the buffer to be written? */ | |
594 | ||
595 | err = journal_next_log_block(journal, &blocknr); | |
596 | /* If the block mapping failed, just abandon the buffer | |
597 | and repeat this loop: we'll fall into the | |
598 | refile-on-abort condition above. */ | |
599 | if (err) { | |
7a266e75 | 600 | journal_abort(journal, err); |
1da177e4 LT |
601 | continue; |
602 | } | |
603 | ||
604 | /* | |
605 | * start_this_handle() uses t_outstanding_credits to determine | |
606 | * the free space in the log, but this counter is changed | |
607 | * by journal_next_log_block() also. | |
608 | */ | |
609 | commit_transaction->t_outstanding_credits--; | |
610 | ||
611 | /* Bump b_count to prevent truncate from stumbling over | |
612 | the shadowed buffer! @@@ This can go if we ever get | |
613 | rid of the BJ_IO/BJ_Shadow pairing of buffers. */ | |
614 | atomic_inc(&jh2bh(jh)->b_count); | |
615 | ||
616 | /* Make a temporary IO buffer with which to write it out | |
617 | (this will requeue both the metadata buffer and the | |
618 | temporary IO buffer). new_bh goes on BJ_IO*/ | |
619 | ||
620 | set_bit(BH_JWrite, &jh2bh(jh)->b_state); | |
621 | /* | |
622 | * akpm: journal_write_metadata_buffer() sets | |
623 | * new_bh->b_transaction to commit_transaction. | |
624 | * We need to clean this up before we release new_bh | |
625 | * (which is of type BJ_IO) | |
626 | */ | |
627 | JBUFFER_TRACE(jh, "ph3: write metadata"); | |
628 | flags = journal_write_metadata_buffer(commit_transaction, | |
629 | jh, &new_jh, blocknr); | |
630 | set_bit(BH_JWrite, &jh2bh(new_jh)->b_state); | |
631 | wbuf[bufs++] = jh2bh(new_jh); | |
632 | ||
633 | /* Record the new block's tag in the current descriptor | |
634 | buffer */ | |
635 | ||
636 | tag_flag = 0; | |
637 | if (flags & 1) | |
638 | tag_flag |= JFS_FLAG_ESCAPE; | |
639 | if (!first_tag) | |
640 | tag_flag |= JFS_FLAG_SAME_UUID; | |
641 | ||
642 | tag = (journal_block_tag_t *) tagp; | |
643 | tag->t_blocknr = cpu_to_be32(jh2bh(jh)->b_blocknr); | |
644 | tag->t_flags = cpu_to_be32(tag_flag); | |
645 | tagp += sizeof(journal_block_tag_t); | |
646 | space_left -= sizeof(journal_block_tag_t); | |
647 | ||
648 | if (first_tag) { | |
649 | memcpy (tagp, journal->j_uuid, 16); | |
650 | tagp += 16; | |
651 | space_left -= 16; | |
652 | first_tag = 0; | |
653 | } | |
654 | ||
655 | /* If there's no more to do, or if the descriptor is full, | |
656 | let the IO rip! */ | |
657 | ||
658 | if (bufs == journal->j_wbufsize || | |
659 | commit_transaction->t_buffers == NULL || | |
660 | space_left < sizeof(journal_block_tag_t) + 16) { | |
661 | ||
662 | jbd_debug(4, "JBD: Submit %d IOs\n", bufs); | |
663 | ||
664 | /* Write an end-of-descriptor marker before | |
665 | submitting the IOs. "tag" still points to | |
666 | the last tag we set up. */ | |
667 | ||
668 | tag->t_flags |= cpu_to_be32(JFS_FLAG_LAST_TAG); | |
669 | ||
670 | start_journal_io: | |
671 | for (i = 0; i < bufs; i++) { | |
672 | struct buffer_head *bh = wbuf[i]; | |
673 | lock_buffer(bh); | |
674 | clear_buffer_dirty(bh); | |
675 | set_buffer_uptodate(bh); | |
676 | bh->b_end_io = journal_end_buffer_io_sync; | |
512a0043 | 677 | submit_bh(write_op, bh); |
1da177e4 LT |
678 | } |
679 | cond_resched(); | |
680 | ||
681 | /* Force a new descriptor to be generated next | |
682 | time round the loop. */ | |
683 | descriptor = NULL; | |
684 | bufs = 0; | |
685 | } | |
686 | } | |
687 | ||
688 | /* Lo and behold: we have just managed to send a transaction to | |
689 | the log. Before we can commit it, wait for the IO so far to | |
690 | complete. Control buffers being written are on the | |
691 | transaction's t_log_list queue, and metadata buffers are on | |
692 | the t_iobuf_list queue. | |
693 | ||
694 | Wait for the buffers in reverse order. That way we are | |
695 | less likely to be woken up until all IOs have completed, and | |
696 | so we incur less scheduling load. | |
697 | */ | |
698 | ||
699 | jbd_debug(3, "JBD: commit phase 4\n"); | |
700 | ||
701 | /* | |
702 | * akpm: these are BJ_IO, and j_list_lock is not needed. | |
703 | * See __journal_try_to_free_buffer. | |
704 | */ | |
705 | wait_for_iobuf: | |
706 | while (commit_transaction->t_iobuf_list != NULL) { | |
707 | struct buffer_head *bh; | |
708 | ||
709 | jh = commit_transaction->t_iobuf_list->b_tprev; | |
710 | bh = jh2bh(jh); | |
711 | if (buffer_locked(bh)) { | |
712 | wait_on_buffer(bh); | |
713 | goto wait_for_iobuf; | |
714 | } | |
715 | if (cond_resched()) | |
716 | goto wait_for_iobuf; | |
717 | ||
718 | if (unlikely(!buffer_uptodate(bh))) | |
719 | err = -EIO; | |
720 | ||
721 | clear_buffer_jwrite(bh); | |
722 | ||
723 | JBUFFER_TRACE(jh, "ph4: unfile after journal write"); | |
724 | journal_unfile_buffer(journal, jh); | |
725 | ||
726 | /* | |
727 | * ->t_iobuf_list should contain only dummy buffer_heads | |
728 | * which were created by journal_write_metadata_buffer(). | |
729 | */ | |
730 | BUFFER_TRACE(bh, "dumping temporary bh"); | |
731 | journal_put_journal_head(jh); | |
732 | __brelse(bh); | |
733 | J_ASSERT_BH(bh, atomic_read(&bh->b_count) == 0); | |
734 | free_buffer_head(bh); | |
735 | ||
736 | /* We also have to unlock and free the corresponding | |
737 | shadowed buffer */ | |
738 | jh = commit_transaction->t_shadow_list->b_tprev; | |
739 | bh = jh2bh(jh); | |
740 | clear_bit(BH_JWrite, &bh->b_state); | |
741 | J_ASSERT_BH(bh, buffer_jbddirty(bh)); | |
742 | ||
743 | /* The metadata is now released for reuse, but we need | |
744 | to remember it against this transaction so that when | |
745 | we finally commit, we can do any checkpointing | |
746 | required. */ | |
747 | JBUFFER_TRACE(jh, "file as BJ_Forget"); | |
748 | journal_file_buffer(jh, commit_transaction, BJ_Forget); | |
749 | /* Wake up any transactions which were waiting for this | |
750 | IO to complete */ | |
751 | wake_up_bit(&bh->b_state, BH_Unshadow); | |
752 | JBUFFER_TRACE(jh, "brelse shadowed buffer"); | |
753 | __brelse(bh); | |
754 | } | |
755 | ||
756 | J_ASSERT (commit_transaction->t_shadow_list == NULL); | |
757 | ||
758 | jbd_debug(3, "JBD: commit phase 5\n"); | |
759 | ||
760 | /* Here we wait for the revoke record and descriptor record buffers */ | |
761 | wait_for_ctlbuf: | |
762 | while (commit_transaction->t_log_list != NULL) { | |
763 | struct buffer_head *bh; | |
764 | ||
765 | jh = commit_transaction->t_log_list->b_tprev; | |
766 | bh = jh2bh(jh); | |
767 | if (buffer_locked(bh)) { | |
768 | wait_on_buffer(bh); | |
769 | goto wait_for_ctlbuf; | |
770 | } | |
771 | if (cond_resched()) | |
772 | goto wait_for_ctlbuf; | |
773 | ||
774 | if (unlikely(!buffer_uptodate(bh))) | |
775 | err = -EIO; | |
776 | ||
777 | BUFFER_TRACE(bh, "ph5: control buffer writeout done: unfile"); | |
778 | clear_buffer_jwrite(bh); | |
779 | journal_unfile_buffer(journal, jh); | |
780 | journal_put_journal_head(jh); | |
781 | __brelse(bh); /* One for getblk */ | |
782 | /* AKPM: bforget here */ | |
783 | } | |
784 | ||
d1645e52 HK |
785 | if (err) |
786 | journal_abort(journal, err); | |
787 | ||
1da177e4 LT |
788 | jbd_debug(3, "JBD: commit phase 6\n"); |
789 | ||
790 | if (journal_write_commit_record(journal, commit_transaction)) | |
791 | err = -EIO; | |
792 | ||
793 | if (err) | |
7a266e75 | 794 | journal_abort(journal, err); |
1da177e4 LT |
795 | |
796 | /* End of a transaction! Finally, we can do checkpoint | |
797 | processing: any buffers committed as a result of this | |
798 | transaction can be removed from any checkpoint list it was on | |
799 | before. */ | |
800 | ||
801 | jbd_debug(3, "JBD: commit phase 7\n"); | |
802 | ||
803 | J_ASSERT(commit_transaction->t_sync_datalist == NULL); | |
804 | J_ASSERT(commit_transaction->t_buffers == NULL); | |
805 | J_ASSERT(commit_transaction->t_checkpoint_list == NULL); | |
806 | J_ASSERT(commit_transaction->t_iobuf_list == NULL); | |
807 | J_ASSERT(commit_transaction->t_shadow_list == NULL); | |
808 | J_ASSERT(commit_transaction->t_log_list == NULL); | |
809 | ||
810 | restart_loop: | |
e6c9f5c1 JK |
811 | /* |
812 | * As there are other places (journal_unmap_buffer()) adding buffers | |
813 | * to this list we have to be careful and hold the j_list_lock. | |
814 | */ | |
815 | spin_lock(&journal->j_list_lock); | |
1da177e4 LT |
816 | while (commit_transaction->t_forget) { |
817 | transaction_t *cp_transaction; | |
818 | struct buffer_head *bh; | |
819 | ||
820 | jh = commit_transaction->t_forget; | |
e6c9f5c1 | 821 | spin_unlock(&journal->j_list_lock); |
1da177e4 LT |
822 | bh = jh2bh(jh); |
823 | jbd_lock_bh_state(bh); | |
824 | J_ASSERT_JH(jh, jh->b_transaction == commit_transaction || | |
825 | jh->b_transaction == journal->j_running_transaction); | |
826 | ||
827 | /* | |
828 | * If there is undo-protected committed data against | |
829 | * this buffer, then we can remove it now. If it is a | |
830 | * buffer needing such protection, the old frozen_data | |
831 | * field now points to a committed version of the | |
832 | * buffer, so rotate that field to the new committed | |
833 | * data. | |
834 | * | |
835 | * Otherwise, we can just throw away the frozen data now. | |
836 | */ | |
837 | if (jh->b_committed_data) { | |
c089d490 | 838 | jbd_free(jh->b_committed_data, bh->b_size); |
1da177e4 LT |
839 | jh->b_committed_data = NULL; |
840 | if (jh->b_frozen_data) { | |
841 | jh->b_committed_data = jh->b_frozen_data; | |
842 | jh->b_frozen_data = NULL; | |
843 | } | |
844 | } else if (jh->b_frozen_data) { | |
c089d490 | 845 | jbd_free(jh->b_frozen_data, bh->b_size); |
1da177e4 LT |
846 | jh->b_frozen_data = NULL; |
847 | } | |
848 | ||
849 | spin_lock(&journal->j_list_lock); | |
850 | cp_transaction = jh->b_cp_transaction; | |
851 | if (cp_transaction) { | |
852 | JBUFFER_TRACE(jh, "remove from old cp transaction"); | |
853 | __journal_remove_checkpoint(jh); | |
854 | } | |
855 | ||
856 | /* Only re-checkpoint the buffer_head if it is marked | |
857 | * dirty. If the buffer was added to the BJ_Forget list | |
858 | * by journal_forget, it may no longer be dirty and | |
859 | * there's no point in keeping a checkpoint record for | |
860 | * it. */ | |
861 | ||
862 | /* A buffer which has been freed while still being | |
863 | * journaled by a previous transaction may end up still | |
864 | * being dirty here, but we want to avoid writing back | |
865 | * that buffer in the future now that the last use has | |
866 | * been committed. That's not only a performance gain, | |
867 | * it also stops aliasing problems if the buffer is left | |
868 | * behind for writeback and gets reallocated for another | |
869 | * use in a different page. */ | |
870 | if (buffer_freed(bh)) { | |
871 | clear_buffer_freed(bh); | |
872 | clear_buffer_jbddirty(bh); | |
873 | } | |
874 | ||
875 | if (buffer_jbddirty(bh)) { | |
876 | JBUFFER_TRACE(jh, "add to new checkpointing trans"); | |
877 | __journal_insert_checkpoint(jh, commit_transaction); | |
885e353c HK |
878 | if (is_journal_aborted(journal)) |
879 | clear_buffer_jbddirty(bh); | |
1da177e4 LT |
880 | JBUFFER_TRACE(jh, "refile for checkpoint writeback"); |
881 | __journal_refile_buffer(jh); | |
882 | jbd_unlock_bh_state(bh); | |
883 | } else { | |
884 | J_ASSERT_BH(bh, !buffer_dirty(bh)); | |
9ada7340 JK |
885 | /* The buffer on BJ_Forget list and not jbddirty means |
886 | * it has been freed by this transaction and hence it | |
887 | * could not have been reallocated until this | |
888 | * transaction has committed. *BUT* it could be | |
889 | * reallocated once we have written all the data to | |
890 | * disk and before we process the buffer on BJ_Forget | |
891 | * list. */ | |
892 | JBUFFER_TRACE(jh, "refile or unfile freed buffer"); | |
893 | __journal_refile_buffer(jh); | |
894 | if (!jh->b_transaction) { | |
895 | jbd_unlock_bh_state(bh); | |
896 | /* needs a brelse */ | |
897 | journal_remove_journal_head(bh); | |
898 | release_buffer_page(bh); | |
899 | } else | |
900 | jbd_unlock_bh_state(bh); | |
1da177e4 | 901 | } |
e6c9f5c1 JK |
902 | cond_resched_lock(&journal->j_list_lock); |
903 | } | |
904 | spin_unlock(&journal->j_list_lock); | |
905 | /* | |
d4beaf4a JK |
906 | * This is a bit sleazy. We use j_list_lock to protect transition |
907 | * of a transaction into T_FINISHED state and calling | |
908 | * __journal_drop_transaction(). Otherwise we could race with | |
909 | * other checkpointing code processing the transaction... | |
e6c9f5c1 JK |
910 | */ |
911 | spin_lock(&journal->j_state_lock); | |
912 | spin_lock(&journal->j_list_lock); | |
913 | /* | |
914 | * Now recheck if some buffers did not get attached to the transaction | |
915 | * while the lock was dropped... | |
916 | */ | |
917 | if (commit_transaction->t_forget) { | |
1da177e4 | 918 | spin_unlock(&journal->j_list_lock); |
e6c9f5c1 JK |
919 | spin_unlock(&journal->j_state_lock); |
920 | goto restart_loop; | |
1da177e4 LT |
921 | } |
922 | ||
923 | /* Done with this transaction! */ | |
924 | ||
925 | jbd_debug(3, "JBD: commit phase 8\n"); | |
926 | ||
927 | J_ASSERT(commit_transaction->t_state == T_COMMIT); | |
928 | ||
1da177e4 LT |
929 | commit_transaction->t_state = T_FINISHED; |
930 | J_ASSERT(commit_transaction == journal->j_committing_transaction); | |
931 | journal->j_commit_sequence = commit_transaction->t_tid; | |
932 | journal->j_committing_transaction = NULL; | |
f420d4dc JB |
933 | commit_time = ktime_to_ns(ktime_sub(ktime_get(), start_time)); |
934 | ||
935 | /* | |
936 | * weight the commit time higher than the average time so we don't | |
937 | * react too strongly to vast changes in commit time | |
938 | */ | |
939 | if (likely(journal->j_average_commit_time)) | |
940 | journal->j_average_commit_time = (commit_time*3 + | |
941 | journal->j_average_commit_time) / 4; | |
942 | else | |
943 | journal->j_average_commit_time = commit_time; | |
944 | ||
1da177e4 LT |
945 | spin_unlock(&journal->j_state_lock); |
946 | ||
fe28e42b JK |
947 | if (commit_transaction->t_checkpoint_list == NULL && |
948 | commit_transaction->t_checkpoint_io_list == NULL) { | |
1da177e4 LT |
949 | __journal_drop_transaction(journal, commit_transaction); |
950 | } else { | |
951 | if (journal->j_checkpoint_transactions == NULL) { | |
952 | journal->j_checkpoint_transactions = commit_transaction; | |
953 | commit_transaction->t_cpnext = commit_transaction; | |
954 | commit_transaction->t_cpprev = commit_transaction; | |
955 | } else { | |
956 | commit_transaction->t_cpnext = | |
957 | journal->j_checkpoint_transactions; | |
958 | commit_transaction->t_cpprev = | |
959 | commit_transaction->t_cpnext->t_cpprev; | |
960 | commit_transaction->t_cpnext->t_cpprev = | |
961 | commit_transaction; | |
962 | commit_transaction->t_cpprev->t_cpnext = | |
963 | commit_transaction; | |
964 | } | |
965 | } | |
966 | spin_unlock(&journal->j_list_lock); | |
967 | ||
968 | jbd_debug(1, "JBD: commit %d complete, head %d\n", | |
969 | journal->j_commit_sequence, journal->j_tail_sequence); | |
970 | ||
971 | wake_up(&journal->j_wait_done_commit); | |
972 | } |