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> | |
1da177e4 LT |
20 | #include <linux/mm.h> |
21 | #include <linux/pagemap.h> | |
512a0043 | 22 | #include <linux/bio.h> |
1da177e4 LT |
23 | |
24 | /* | |
25 | * Default IO end handler for temporary BJ_IO buffer_heads. | |
26 | */ | |
27 | static void journal_end_buffer_io_sync(struct buffer_head *bh, int uptodate) | |
28 | { | |
29 | BUFFER_TRACE(bh, ""); | |
30 | if (uptodate) | |
31 | set_buffer_uptodate(bh); | |
32 | else | |
33 | clear_buffer_uptodate(bh); | |
34 | unlock_buffer(bh); | |
35 | } | |
36 | ||
37 | /* | |
38 | * When an ext3-ordered file is truncated, it is possible that many pages are | |
fc80c442 | 39 | * not successfully freed, because they are attached to a committing transaction. |
1da177e4 LT |
40 | * After the transaction commits, these pages are left on the LRU, with no |
41 | * ->mapping, and with attached buffers. These pages are trivially reclaimable | |
42 | * by the VM, but their apparent absence upsets the VM accounting, and it makes | |
43 | * the numbers in /proc/meminfo look odd. | |
44 | * | |
45 | * So here, we have a buffer which has just come off the forget list. Look to | |
46 | * see if we can strip all buffers from the backing page. | |
47 | * | |
fc80c442 TO |
48 | * Called under journal->j_list_lock. The caller provided us with a ref |
49 | * against the buffer, and we drop that here. | |
1da177e4 LT |
50 | */ |
51 | static void release_buffer_page(struct buffer_head *bh) | |
52 | { | |
53 | struct page *page; | |
54 | ||
55 | if (buffer_dirty(bh)) | |
56 | goto nope; | |
57 | if (atomic_read(&bh->b_count) != 1) | |
58 | goto nope; | |
59 | page = bh->b_page; | |
60 | if (!page) | |
61 | goto nope; | |
62 | if (page->mapping) | |
63 | goto nope; | |
64 | ||
65 | /* OK, it's a truncated page */ | |
529ae9aa | 66 | if (!trylock_page(page)) |
1da177e4 LT |
67 | goto nope; |
68 | ||
69 | page_cache_get(page); | |
70 | __brelse(bh); | |
71 | try_to_free_buffers(page); | |
72 | unlock_page(page); | |
73 | page_cache_release(page); | |
74 | return; | |
75 | ||
76 | nope: | |
77 | __brelse(bh); | |
78 | } | |
79 | ||
fc80c442 TO |
80 | /* |
81 | * Decrement reference counter for data buffer. If it has been marked | |
82 | * 'BH_Freed', release it and the page to which it belongs if possible. | |
83 | */ | |
84 | static void release_data_buffer(struct buffer_head *bh) | |
85 | { | |
86 | if (buffer_freed(bh)) { | |
87 | clear_buffer_freed(bh); | |
88 | release_buffer_page(bh); | |
89 | } else | |
90 | put_bh(bh); | |
91 | } | |
92 | ||
1da177e4 LT |
93 | /* |
94 | * Try to acquire jbd_lock_bh_state() against the buffer, when j_list_lock is | |
95 | * held. For ranking reasons we must trylock. If we lose, schedule away and | |
96 | * return 0. j_list_lock is dropped in this case. | |
97 | */ | |
98 | static int inverted_lock(journal_t *journal, struct buffer_head *bh) | |
99 | { | |
100 | if (!jbd_trylock_bh_state(bh)) { | |
101 | spin_unlock(&journal->j_list_lock); | |
102 | schedule(); | |
103 | return 0; | |
104 | } | |
105 | return 1; | |
106 | } | |
107 | ||
108 | /* Done it all: now write the commit record. We should have | |
109 | * cleaned up our previous buffers by now, so if we are in abort | |
110 | * mode we can now just skip the rest of the journal write | |
111 | * entirely. | |
112 | * | |
113 | * Returns 1 if the journal needs to be aborted or 0 on success | |
114 | */ | |
115 | static int journal_write_commit_record(journal_t *journal, | |
116 | transaction_t *commit_transaction) | |
117 | { | |
118 | struct journal_head *descriptor; | |
119 | struct buffer_head *bh; | |
5315217e JK |
120 | journal_header_t *header; |
121 | int ret; | |
1da177e4 LT |
122 | |
123 | if (is_journal_aborted(journal)) | |
124 | return 0; | |
125 | ||
126 | descriptor = journal_get_descriptor_buffer(journal); | |
127 | if (!descriptor) | |
128 | return 1; | |
129 | ||
130 | bh = jh2bh(descriptor); | |
131 | ||
5315217e JK |
132 | header = (journal_header_t *)(bh->b_data); |
133 | header->h_magic = cpu_to_be32(JFS_MAGIC_NUMBER); | |
134 | header->h_blocktype = cpu_to_be32(JFS_COMMIT_BLOCK); | |
135 | header->h_sequence = cpu_to_be32(commit_transaction->t_tid); | |
1da177e4 LT |
136 | |
137 | JBUFFER_TRACE(descriptor, "write commit block"); | |
138 | set_buffer_dirty(bh); | |
87e99511 | 139 | |
4524451e CH |
140 | if (journal->j_flags & JFS_BARRIER) |
141 | ret = __sync_dirty_buffer(bh, WRITE_SYNC | WRITE_FLUSH_FUA); | |
142 | else | |
1da177e4 | 143 | ret = sync_dirty_buffer(bh); |
87e99511 | 144 | |
1da177e4 LT |
145 | put_bh(bh); /* One for getblk() */ |
146 | journal_put_journal_head(descriptor); | |
147 | ||
148 | return (ret == -EIO); | |
149 | } | |
150 | ||
512a0043 TT |
151 | static void journal_do_submit_data(struct buffer_head **wbuf, int bufs, |
152 | int write_op) | |
3998b930 JK |
153 | { |
154 | int i; | |
155 | ||
156 | for (i = 0; i < bufs; i++) { | |
157 | wbuf[i]->b_end_io = end_buffer_write_sync; | |
158 | /* We use-up our safety reference in submit_bh() */ | |
512a0043 | 159 | submit_bh(write_op, wbuf[i]); |
3998b930 JK |
160 | } |
161 | } | |
162 | ||
163 | /* | |
164 | * Submit all the data buffers to disk | |
165 | */ | |
cbe5f466 | 166 | static int journal_submit_data_buffers(journal_t *journal, |
512a0043 TT |
167 | transaction_t *commit_transaction, |
168 | int write_op) | |
3998b930 JK |
169 | { |
170 | struct journal_head *jh; | |
171 | struct buffer_head *bh; | |
172 | int locked; | |
173 | int bufs = 0; | |
174 | struct buffer_head **wbuf = journal->j_wbuf; | |
cbe5f466 | 175 | int err = 0; |
3998b930 JK |
176 | |
177 | /* | |
178 | * Whenever we unlock the journal and sleep, things can get added | |
179 | * onto ->t_sync_datalist, so we have to keep looping back to | |
180 | * write_out_data until we *know* that the list is empty. | |
181 | * | |
182 | * Cleanup any flushed data buffers from the data list. Even in | |
183 | * abort mode, we want to flush this out as soon as possible. | |
184 | */ | |
185 | write_out_data: | |
186 | cond_resched(); | |
187 | spin_lock(&journal->j_list_lock); | |
188 | ||
189 | while (commit_transaction->t_sync_datalist) { | |
190 | jh = commit_transaction->t_sync_datalist; | |
191 | bh = jh2bh(jh); | |
192 | locked = 0; | |
193 | ||
194 | /* Get reference just to make sure buffer does not disappear | |
195 | * when we are forced to drop various locks */ | |
196 | get_bh(bh); | |
197 | /* If the buffer is dirty, we need to submit IO and hence | |
198 | * we need the buffer lock. We try to lock the buffer without | |
199 | * blocking. If we fail, we need to drop j_list_lock and do | |
200 | * blocking lock_buffer(). | |
201 | */ | |
202 | if (buffer_dirty(bh)) { | |
ca5de404 | 203 | if (!trylock_buffer(bh)) { |
3998b930 JK |
204 | BUFFER_TRACE(bh, "needs blocking lock"); |
205 | spin_unlock(&journal->j_list_lock); | |
206 | /* Write out all data to prevent deadlocks */ | |
512a0043 | 207 | journal_do_submit_data(wbuf, bufs, write_op); |
3998b930 JK |
208 | bufs = 0; |
209 | lock_buffer(bh); | |
210 | spin_lock(&journal->j_list_lock); | |
211 | } | |
212 | locked = 1; | |
213 | } | |
214 | /* We have to get bh_state lock. Again out of order, sigh. */ | |
215 | if (!inverted_lock(journal, bh)) { | |
216 | jbd_lock_bh_state(bh); | |
217 | spin_lock(&journal->j_list_lock); | |
218 | } | |
219 | /* Someone already cleaned up the buffer? */ | |
a61d90d7 | 220 | if (!buffer_jbd(bh) || bh2jh(bh) != jh |
3998b930 JK |
221 | || jh->b_transaction != commit_transaction |
222 | || jh->b_jlist != BJ_SyncData) { | |
223 | jbd_unlock_bh_state(bh); | |
224 | if (locked) | |
225 | unlock_buffer(bh); | |
226 | BUFFER_TRACE(bh, "already cleaned up"); | |
fc80c442 | 227 | release_data_buffer(bh); |
3998b930 JK |
228 | continue; |
229 | } | |
230 | if (locked && test_clear_buffer_dirty(bh)) { | |
231 | BUFFER_TRACE(bh, "needs writeout, adding to array"); | |
232 | wbuf[bufs++] = bh; | |
233 | __journal_file_buffer(jh, commit_transaction, | |
234 | BJ_Locked); | |
235 | jbd_unlock_bh_state(bh); | |
236 | if (bufs == journal->j_wbufsize) { | |
237 | spin_unlock(&journal->j_list_lock); | |
512a0043 | 238 | journal_do_submit_data(wbuf, bufs, write_op); |
3998b930 JK |
239 | bufs = 0; |
240 | goto write_out_data; | |
241 | } | |
6f5a9da1 HH |
242 | } else if (!locked && buffer_locked(bh)) { |
243 | __journal_file_buffer(jh, commit_transaction, | |
244 | BJ_Locked); | |
245 | jbd_unlock_bh_state(bh); | |
246 | put_bh(bh); | |
247 | } else { | |
3998b930 | 248 | BUFFER_TRACE(bh, "writeout complete: unfile"); |
cbe5f466 HK |
249 | if (unlikely(!buffer_uptodate(bh))) |
250 | err = -EIO; | |
3998b930 JK |
251 | __journal_unfile_buffer(jh); |
252 | jbd_unlock_bh_state(bh); | |
253 | if (locked) | |
254 | unlock_buffer(bh); | |
255 | journal_remove_journal_head(bh); | |
fc80c442 | 256 | /* One for our safety reference, other for |
3998b930 JK |
257 | * journal_remove_journal_head() */ |
258 | put_bh(bh); | |
fc80c442 | 259 | release_data_buffer(bh); |
3998b930 JK |
260 | } |
261 | ||
95c354fe | 262 | if (need_resched() || spin_needbreak(&journal->j_list_lock)) { |
3998b930 JK |
263 | spin_unlock(&journal->j_list_lock); |
264 | goto write_out_data; | |
265 | } | |
266 | } | |
267 | spin_unlock(&journal->j_list_lock); | |
512a0043 | 268 | journal_do_submit_data(wbuf, bufs, write_op); |
cbe5f466 HK |
269 | |
270 | return err; | |
3998b930 JK |
271 | } |
272 | ||
1da177e4 LT |
273 | /* |
274 | * journal_commit_transaction | |
275 | * | |
276 | * The primary function for committing a transaction to the log. This | |
277 | * function is called by the journal thread to begin a complete commit. | |
278 | */ | |
279 | void journal_commit_transaction(journal_t *journal) | |
280 | { | |
281 | transaction_t *commit_transaction; | |
282 | struct journal_head *jh, *new_jh, *descriptor; | |
283 | struct buffer_head **wbuf = journal->j_wbuf; | |
284 | int bufs; | |
285 | int flags; | |
286 | int err; | |
9c28cbcc | 287 | unsigned int blocknr; |
f420d4dc JB |
288 | ktime_t start_time; |
289 | u64 commit_time; | |
1da177e4 LT |
290 | char *tagp = NULL; |
291 | journal_header_t *header; | |
292 | journal_block_tag_t *tag = NULL; | |
293 | int space_left = 0; | |
294 | int first_tag = 0; | |
295 | int tag_flag; | |
296 | int i; | |
749ef9f8 | 297 | int write_op = WRITE_SYNC; |
1da177e4 LT |
298 | |
299 | /* | |
300 | * First job: lock down the current transaction and wait for | |
301 | * all outstanding updates to complete. | |
302 | */ | |
303 | ||
304 | #ifdef COMMIT_STATS | |
305 | spin_lock(&journal->j_list_lock); | |
306 | summarise_journal_usage(journal); | |
307 | spin_unlock(&journal->j_list_lock); | |
308 | #endif | |
309 | ||
310 | /* Do we need to erase the effects of a prior journal_flush? */ | |
311 | if (journal->j_flags & JFS_FLUSHED) { | |
312 | jbd_debug(3, "super block updated\n"); | |
313 | journal_update_superblock(journal, 1); | |
314 | } else { | |
315 | jbd_debug(3, "superblock not updated\n"); | |
316 | } | |
317 | ||
318 | J_ASSERT(journal->j_running_transaction != NULL); | |
319 | J_ASSERT(journal->j_committing_transaction == NULL); | |
320 | ||
321 | commit_transaction = journal->j_running_transaction; | |
322 | J_ASSERT(commit_transaction->t_state == T_RUNNING); | |
323 | ||
324 | jbd_debug(1, "JBD: starting commit of transaction %d\n", | |
325 | commit_transaction->t_tid); | |
326 | ||
327 | spin_lock(&journal->j_state_lock); | |
328 | commit_transaction->t_state = T_LOCKED; | |
329 | ||
6c4bac6b JA |
330 | /* |
331 | * Use plugged writes here, since we want to submit several before | |
332 | * we unplug the device. We don't do explicit unplugging in here, | |
333 | * instead we rely on sync_buffer() doing the unplug for us. | |
334 | */ | |
512a0043 | 335 | if (commit_transaction->t_synchronous_commit) |
6c4bac6b | 336 | write_op = WRITE_SYNC_PLUG; |
1da177e4 LT |
337 | spin_lock(&commit_transaction->t_handle_lock); |
338 | while (commit_transaction->t_updates) { | |
339 | DEFINE_WAIT(wait); | |
340 | ||
341 | prepare_to_wait(&journal->j_wait_updates, &wait, | |
342 | TASK_UNINTERRUPTIBLE); | |
343 | if (commit_transaction->t_updates) { | |
344 | spin_unlock(&commit_transaction->t_handle_lock); | |
345 | spin_unlock(&journal->j_state_lock); | |
346 | schedule(); | |
347 | spin_lock(&journal->j_state_lock); | |
348 | spin_lock(&commit_transaction->t_handle_lock); | |
349 | } | |
350 | finish_wait(&journal->j_wait_updates, &wait); | |
351 | } | |
352 | spin_unlock(&commit_transaction->t_handle_lock); | |
353 | ||
354 | J_ASSERT (commit_transaction->t_outstanding_credits <= | |
355 | journal->j_max_transaction_buffers); | |
356 | ||
357 | /* | |
358 | * First thing we are allowed to do is to discard any remaining | |
359 | * BJ_Reserved buffers. Note, it is _not_ permissible to assume | |
360 | * that there are no such buffers: if a large filesystem | |
361 | * operation like a truncate needs to split itself over multiple | |
362 | * transactions, then it may try to do a journal_restart() while | |
363 | * there are still BJ_Reserved buffers outstanding. These must | |
364 | * be released cleanly from the current transaction. | |
365 | * | |
366 | * In this case, the filesystem must still reserve write access | |
367 | * again before modifying the buffer in the new transaction, but | |
368 | * we do not require it to remember exactly which old buffers it | |
369 | * has reserved. This is consistent with the existing behaviour | |
370 | * that multiple journal_get_write_access() calls to the same | |
371 | * buffer are perfectly permissable. | |
372 | */ | |
373 | while (commit_transaction->t_reserved_list) { | |
374 | jh = commit_transaction->t_reserved_list; | |
375 | JBUFFER_TRACE(jh, "reserved, unused: refile"); | |
376 | /* | |
377 | * A journal_get_undo_access()+journal_release_buffer() may | |
378 | * leave undo-committed data. | |
379 | */ | |
380 | if (jh->b_committed_data) { | |
381 | struct buffer_head *bh = jh2bh(jh); | |
382 | ||
383 | jbd_lock_bh_state(bh); | |
c089d490 | 384 | jbd_free(jh->b_committed_data, bh->b_size); |
f99d49ad | 385 | jh->b_committed_data = NULL; |
1da177e4 LT |
386 | jbd_unlock_bh_state(bh); |
387 | } | |
388 | journal_refile_buffer(journal, jh); | |
389 | } | |
390 | ||
391 | /* | |
392 | * Now try to drop any written-back buffers from the journal's | |
393 | * checkpoint lists. We do this *before* commit because it potentially | |
394 | * frees some memory | |
395 | */ | |
396 | spin_lock(&journal->j_list_lock); | |
397 | __journal_clean_checkpoint_list(journal); | |
398 | spin_unlock(&journal->j_list_lock); | |
399 | ||
400 | jbd_debug (3, "JBD: commit phase 1\n"); | |
401 | ||
402 | /* | |
403 | * Switch to a new revoke table. | |
404 | */ | |
405 | journal_switch_revoke_table(journal); | |
406 | ||
407 | commit_transaction->t_state = T_FLUSH; | |
408 | journal->j_committing_transaction = commit_transaction; | |
409 | journal->j_running_transaction = NULL; | |
f420d4dc | 410 | start_time = ktime_get(); |
1da177e4 LT |
411 | commit_transaction->t_log_start = journal->j_head; |
412 | wake_up(&journal->j_wait_transaction_locked); | |
413 | spin_unlock(&journal->j_state_lock); | |
414 | ||
415 | jbd_debug (3, "JBD: commit phase 2\n"); | |
416 | ||
1da177e4 LT |
417 | /* |
418 | * Now start flushing things to disk, in the order they appear | |
419 | * on the transaction lists. Data blocks go first. | |
420 | */ | |
512a0043 TT |
421 | err = journal_submit_data_buffers(journal, commit_transaction, |
422 | write_op); | |
1da177e4 LT |
423 | |
424 | /* | |
425 | * Wait for all previously submitted IO to complete. | |
426 | */ | |
3998b930 | 427 | spin_lock(&journal->j_list_lock); |
1da177e4 LT |
428 | while (commit_transaction->t_locked_list) { |
429 | struct buffer_head *bh; | |
430 | ||
431 | jh = commit_transaction->t_locked_list->b_tprev; | |
432 | bh = jh2bh(jh); | |
433 | get_bh(bh); | |
434 | if (buffer_locked(bh)) { | |
435 | spin_unlock(&journal->j_list_lock); | |
436 | wait_on_buffer(bh); | |
1da177e4 LT |
437 | spin_lock(&journal->j_list_lock); |
438 | } | |
cbe5f466 | 439 | if (unlikely(!buffer_uptodate(bh))) { |
529ae9aa | 440 | if (!trylock_page(bh->b_page)) { |
cbe5f466 HK |
441 | spin_unlock(&journal->j_list_lock); |
442 | lock_page(bh->b_page); | |
443 | spin_lock(&journal->j_list_lock); | |
444 | } | |
445 | if (bh->b_page->mapping) | |
446 | set_bit(AS_EIO, &bh->b_page->mapping->flags); | |
447 | ||
448 | unlock_page(bh->b_page); | |
449 | SetPageError(bh->b_page); | |
450 | err = -EIO; | |
451 | } | |
1da177e4 LT |
452 | if (!inverted_lock(journal, bh)) { |
453 | put_bh(bh); | |
454 | spin_lock(&journal->j_list_lock); | |
455 | continue; | |
456 | } | |
a61d90d7 JK |
457 | if (buffer_jbd(bh) && bh2jh(bh) == jh && |
458 | jh->b_transaction == commit_transaction && | |
459 | jh->b_jlist == BJ_Locked) { | |
1da177e4 LT |
460 | __journal_unfile_buffer(jh); |
461 | jbd_unlock_bh_state(bh); | |
462 | journal_remove_journal_head(bh); | |
463 | put_bh(bh); | |
464 | } else { | |
465 | jbd_unlock_bh_state(bh); | |
466 | } | |
fc80c442 | 467 | release_data_buffer(bh); |
1da177e4 LT |
468 | cond_resched_lock(&journal->j_list_lock); |
469 | } | |
470 | spin_unlock(&journal->j_list_lock); | |
471 | ||
cbe5f466 HK |
472 | if (err) { |
473 | char b[BDEVNAME_SIZE]; | |
474 | ||
475 | printk(KERN_WARNING | |
476 | "JBD: Detected IO errors while flushing file data " | |
477 | "on %s\n", bdevname(journal->j_fs_dev, b)); | |
0e4fb5e2 HK |
478 | if (journal->j_flags & JFS_ABORT_ON_SYNCDATA_ERR) |
479 | journal_abort(journal, err); | |
cbe5f466 HK |
480 | err = 0; |
481 | } | |
1da177e4 | 482 | |
38d726d1 | 483 | journal_write_revoke_records(journal, commit_transaction, write_op); |
1da177e4 | 484 | |
1da177e4 LT |
485 | /* |
486 | * If we found any dirty or locked buffers, then we should have | |
487 | * looped back up to the write_out_data label. If there weren't | |
488 | * any then journal_clean_data_list should have wiped the list | |
489 | * clean by now, so check that it is in fact empty. | |
490 | */ | |
491 | J_ASSERT (commit_transaction->t_sync_datalist == NULL); | |
492 | ||
493 | jbd_debug (3, "JBD: commit phase 3\n"); | |
494 | ||
495 | /* | |
496 | * Way to go: we have now written out all of the data for a | |
497 | * transaction! Now comes the tricky part: we need to write out | |
498 | * metadata. Loop over the transaction's entire buffer list: | |
499 | */ | |
772279c5 | 500 | spin_lock(&journal->j_state_lock); |
1da177e4 | 501 | commit_transaction->t_state = T_COMMIT; |
772279c5 | 502 | spin_unlock(&journal->j_state_lock); |
1da177e4 | 503 | |
5b9a499d JB |
504 | J_ASSERT(commit_transaction->t_nr_buffers <= |
505 | commit_transaction->t_outstanding_credits); | |
506 | ||
1da177e4 LT |
507 | descriptor = NULL; |
508 | bufs = 0; | |
509 | while (commit_transaction->t_buffers) { | |
510 | ||
511 | /* Find the next buffer to be journaled... */ | |
512 | ||
513 | jh = commit_transaction->t_buffers; | |
514 | ||
515 | /* If we're in abort mode, we just un-journal the buffer and | |
885e353c | 516 | release it. */ |
1da177e4 LT |
517 | |
518 | if (is_journal_aborted(journal)) { | |
885e353c | 519 | clear_buffer_jbddirty(jh2bh(jh)); |
1da177e4 LT |
520 | JBUFFER_TRACE(jh, "journal is aborting: refile"); |
521 | journal_refile_buffer(journal, jh); | |
522 | /* If that was the last one, we need to clean up | |
523 | * any descriptor buffers which may have been | |
524 | * already allocated, even if we are now | |
525 | * aborting. */ | |
526 | if (!commit_transaction->t_buffers) | |
527 | goto start_journal_io; | |
528 | continue; | |
529 | } | |
530 | ||
531 | /* Make sure we have a descriptor block in which to | |
532 | record the metadata buffer. */ | |
533 | ||
534 | if (!descriptor) { | |
535 | struct buffer_head *bh; | |
536 | ||
537 | J_ASSERT (bufs == 0); | |
538 | ||
539 | jbd_debug(4, "JBD: get descriptor\n"); | |
540 | ||
541 | descriptor = journal_get_descriptor_buffer(journal); | |
542 | if (!descriptor) { | |
7a266e75 | 543 | journal_abort(journal, -EIO); |
1da177e4 LT |
544 | continue; |
545 | } | |
546 | ||
547 | bh = jh2bh(descriptor); | |
548 | jbd_debug(4, "JBD: got buffer %llu (%p)\n", | |
549 | (unsigned long long)bh->b_blocknr, bh->b_data); | |
550 | header = (journal_header_t *)&bh->b_data[0]; | |
551 | header->h_magic = cpu_to_be32(JFS_MAGIC_NUMBER); | |
552 | header->h_blocktype = cpu_to_be32(JFS_DESCRIPTOR_BLOCK); | |
553 | header->h_sequence = cpu_to_be32(commit_transaction->t_tid); | |
554 | ||
555 | tagp = &bh->b_data[sizeof(journal_header_t)]; | |
556 | space_left = bh->b_size - sizeof(journal_header_t); | |
557 | first_tag = 1; | |
558 | set_buffer_jwrite(bh); | |
559 | set_buffer_dirty(bh); | |
560 | wbuf[bufs++] = bh; | |
561 | ||
562 | /* Record it so that we can wait for IO | |
563 | completion later */ | |
564 | BUFFER_TRACE(bh, "ph3: file as descriptor"); | |
565 | journal_file_buffer(descriptor, commit_transaction, | |
566 | BJ_LogCtl); | |
567 | } | |
568 | ||
569 | /* Where is the buffer to be written? */ | |
570 | ||
571 | err = journal_next_log_block(journal, &blocknr); | |
572 | /* If the block mapping failed, just abandon the buffer | |
573 | and repeat this loop: we'll fall into the | |
574 | refile-on-abort condition above. */ | |
575 | if (err) { | |
7a266e75 | 576 | journal_abort(journal, err); |
1da177e4 LT |
577 | continue; |
578 | } | |
579 | ||
580 | /* | |
581 | * start_this_handle() uses t_outstanding_credits to determine | |
582 | * the free space in the log, but this counter is changed | |
583 | * by journal_next_log_block() also. | |
584 | */ | |
585 | commit_transaction->t_outstanding_credits--; | |
586 | ||
587 | /* Bump b_count to prevent truncate from stumbling over | |
588 | the shadowed buffer! @@@ This can go if we ever get | |
589 | rid of the BJ_IO/BJ_Shadow pairing of buffers. */ | |
e4d5e3a4 | 590 | get_bh(jh2bh(jh)); |
1da177e4 LT |
591 | |
592 | /* Make a temporary IO buffer with which to write it out | |
593 | (this will requeue both the metadata buffer and the | |
594 | temporary IO buffer). new_bh goes on BJ_IO*/ | |
595 | ||
a910eefa | 596 | set_buffer_jwrite(jh2bh(jh)); |
1da177e4 LT |
597 | /* |
598 | * akpm: journal_write_metadata_buffer() sets | |
599 | * new_bh->b_transaction to commit_transaction. | |
600 | * We need to clean this up before we release new_bh | |
601 | * (which is of type BJ_IO) | |
602 | */ | |
603 | JBUFFER_TRACE(jh, "ph3: write metadata"); | |
604 | flags = journal_write_metadata_buffer(commit_transaction, | |
605 | jh, &new_jh, blocknr); | |
a910eefa | 606 | set_buffer_jwrite(jh2bh(new_jh)); |
1da177e4 LT |
607 | wbuf[bufs++] = jh2bh(new_jh); |
608 | ||
609 | /* Record the new block's tag in the current descriptor | |
610 | buffer */ | |
611 | ||
612 | tag_flag = 0; | |
613 | if (flags & 1) | |
614 | tag_flag |= JFS_FLAG_ESCAPE; | |
615 | if (!first_tag) | |
616 | tag_flag |= JFS_FLAG_SAME_UUID; | |
617 | ||
618 | tag = (journal_block_tag_t *) tagp; | |
619 | tag->t_blocknr = cpu_to_be32(jh2bh(jh)->b_blocknr); | |
620 | tag->t_flags = cpu_to_be32(tag_flag); | |
621 | tagp += sizeof(journal_block_tag_t); | |
622 | space_left -= sizeof(journal_block_tag_t); | |
623 | ||
624 | if (first_tag) { | |
625 | memcpy (tagp, journal->j_uuid, 16); | |
626 | tagp += 16; | |
627 | space_left -= 16; | |
628 | first_tag = 0; | |
629 | } | |
630 | ||
631 | /* If there's no more to do, or if the descriptor is full, | |
632 | let the IO rip! */ | |
633 | ||
634 | if (bufs == journal->j_wbufsize || | |
635 | commit_transaction->t_buffers == NULL || | |
636 | space_left < sizeof(journal_block_tag_t) + 16) { | |
637 | ||
638 | jbd_debug(4, "JBD: Submit %d IOs\n", bufs); | |
639 | ||
640 | /* Write an end-of-descriptor marker before | |
641 | submitting the IOs. "tag" still points to | |
642 | the last tag we set up. */ | |
643 | ||
644 | tag->t_flags |= cpu_to_be32(JFS_FLAG_LAST_TAG); | |
645 | ||
646 | start_journal_io: | |
647 | for (i = 0; i < bufs; i++) { | |
648 | struct buffer_head *bh = wbuf[i]; | |
649 | lock_buffer(bh); | |
650 | clear_buffer_dirty(bh); | |
651 | set_buffer_uptodate(bh); | |
652 | bh->b_end_io = journal_end_buffer_io_sync; | |
512a0043 | 653 | submit_bh(write_op, bh); |
1da177e4 LT |
654 | } |
655 | cond_resched(); | |
656 | ||
657 | /* Force a new descriptor to be generated next | |
658 | time round the loop. */ | |
659 | descriptor = NULL; | |
660 | bufs = 0; | |
661 | } | |
662 | } | |
663 | ||
664 | /* Lo and behold: we have just managed to send a transaction to | |
665 | the log. Before we can commit it, wait for the IO so far to | |
666 | complete. Control buffers being written are on the | |
667 | transaction's t_log_list queue, and metadata buffers are on | |
668 | the t_iobuf_list queue. | |
669 | ||
670 | Wait for the buffers in reverse order. That way we are | |
671 | less likely to be woken up until all IOs have completed, and | |
672 | so we incur less scheduling load. | |
673 | */ | |
674 | ||
675 | jbd_debug(3, "JBD: commit phase 4\n"); | |
676 | ||
677 | /* | |
678 | * akpm: these are BJ_IO, and j_list_lock is not needed. | |
679 | * See __journal_try_to_free_buffer. | |
680 | */ | |
681 | wait_for_iobuf: | |
682 | while (commit_transaction->t_iobuf_list != NULL) { | |
683 | struct buffer_head *bh; | |
684 | ||
685 | jh = commit_transaction->t_iobuf_list->b_tprev; | |
686 | bh = jh2bh(jh); | |
687 | if (buffer_locked(bh)) { | |
688 | wait_on_buffer(bh); | |
689 | goto wait_for_iobuf; | |
690 | } | |
691 | if (cond_resched()) | |
692 | goto wait_for_iobuf; | |
693 | ||
694 | if (unlikely(!buffer_uptodate(bh))) | |
695 | err = -EIO; | |
696 | ||
697 | clear_buffer_jwrite(bh); | |
698 | ||
699 | JBUFFER_TRACE(jh, "ph4: unfile after journal write"); | |
700 | journal_unfile_buffer(journal, jh); | |
701 | ||
702 | /* | |
703 | * ->t_iobuf_list should contain only dummy buffer_heads | |
704 | * which were created by journal_write_metadata_buffer(). | |
705 | */ | |
706 | BUFFER_TRACE(bh, "dumping temporary bh"); | |
707 | journal_put_journal_head(jh); | |
708 | __brelse(bh); | |
709 | J_ASSERT_BH(bh, atomic_read(&bh->b_count) == 0); | |
710 | free_buffer_head(bh); | |
711 | ||
712 | /* We also have to unlock and free the corresponding | |
713 | shadowed buffer */ | |
714 | jh = commit_transaction->t_shadow_list->b_tprev; | |
715 | bh = jh2bh(jh); | |
a910eefa | 716 | clear_buffer_jwrite(bh); |
1da177e4 LT |
717 | J_ASSERT_BH(bh, buffer_jbddirty(bh)); |
718 | ||
719 | /* The metadata is now released for reuse, but we need | |
720 | to remember it against this transaction so that when | |
721 | we finally commit, we can do any checkpointing | |
722 | required. */ | |
723 | JBUFFER_TRACE(jh, "file as BJ_Forget"); | |
724 | journal_file_buffer(jh, commit_transaction, BJ_Forget); | |
725 | /* Wake up any transactions which were waiting for this | |
726 | IO to complete */ | |
727 | wake_up_bit(&bh->b_state, BH_Unshadow); | |
728 | JBUFFER_TRACE(jh, "brelse shadowed buffer"); | |
729 | __brelse(bh); | |
730 | } | |
731 | ||
732 | J_ASSERT (commit_transaction->t_shadow_list == NULL); | |
733 | ||
734 | jbd_debug(3, "JBD: commit phase 5\n"); | |
735 | ||
736 | /* Here we wait for the revoke record and descriptor record buffers */ | |
737 | wait_for_ctlbuf: | |
738 | while (commit_transaction->t_log_list != NULL) { | |
739 | struct buffer_head *bh; | |
740 | ||
741 | jh = commit_transaction->t_log_list->b_tprev; | |
742 | bh = jh2bh(jh); | |
743 | if (buffer_locked(bh)) { | |
744 | wait_on_buffer(bh); | |
745 | goto wait_for_ctlbuf; | |
746 | } | |
747 | if (cond_resched()) | |
748 | goto wait_for_ctlbuf; | |
749 | ||
750 | if (unlikely(!buffer_uptodate(bh))) | |
751 | err = -EIO; | |
752 | ||
753 | BUFFER_TRACE(bh, "ph5: control buffer writeout done: unfile"); | |
754 | clear_buffer_jwrite(bh); | |
755 | journal_unfile_buffer(journal, jh); | |
756 | journal_put_journal_head(jh); | |
757 | __brelse(bh); /* One for getblk */ | |
758 | /* AKPM: bforget here */ | |
759 | } | |
760 | ||
d1645e52 HK |
761 | if (err) |
762 | journal_abort(journal, err); | |
763 | ||
1da177e4 LT |
764 | jbd_debug(3, "JBD: commit phase 6\n"); |
765 | ||
03f4d804 JK |
766 | /* All metadata is written, now write commit record and do cleanup */ |
767 | spin_lock(&journal->j_state_lock); | |
768 | J_ASSERT(commit_transaction->t_state == T_COMMIT); | |
769 | commit_transaction->t_state = T_COMMIT_RECORD; | |
770 | spin_unlock(&journal->j_state_lock); | |
771 | ||
1da177e4 LT |
772 | if (journal_write_commit_record(journal, commit_transaction)) |
773 | err = -EIO; | |
774 | ||
775 | if (err) | |
7a266e75 | 776 | journal_abort(journal, err); |
1da177e4 LT |
777 | |
778 | /* End of a transaction! Finally, we can do checkpoint | |
779 | processing: any buffers committed as a result of this | |
780 | transaction can be removed from any checkpoint list it was on | |
781 | before. */ | |
782 | ||
783 | jbd_debug(3, "JBD: commit phase 7\n"); | |
784 | ||
785 | J_ASSERT(commit_transaction->t_sync_datalist == NULL); | |
786 | J_ASSERT(commit_transaction->t_buffers == NULL); | |
787 | J_ASSERT(commit_transaction->t_checkpoint_list == NULL); | |
788 | J_ASSERT(commit_transaction->t_iobuf_list == NULL); | |
789 | J_ASSERT(commit_transaction->t_shadow_list == NULL); | |
790 | J_ASSERT(commit_transaction->t_log_list == NULL); | |
791 | ||
792 | restart_loop: | |
e6c9f5c1 JK |
793 | /* |
794 | * As there are other places (journal_unmap_buffer()) adding buffers | |
795 | * to this list we have to be careful and hold the j_list_lock. | |
796 | */ | |
797 | spin_lock(&journal->j_list_lock); | |
1da177e4 LT |
798 | while (commit_transaction->t_forget) { |
799 | transaction_t *cp_transaction; | |
800 | struct buffer_head *bh; | |
801 | ||
802 | jh = commit_transaction->t_forget; | |
e6c9f5c1 | 803 | spin_unlock(&journal->j_list_lock); |
1da177e4 LT |
804 | bh = jh2bh(jh); |
805 | jbd_lock_bh_state(bh); | |
806 | J_ASSERT_JH(jh, jh->b_transaction == commit_transaction || | |
807 | jh->b_transaction == journal->j_running_transaction); | |
808 | ||
809 | /* | |
810 | * If there is undo-protected committed data against | |
811 | * this buffer, then we can remove it now. If it is a | |
812 | * buffer needing such protection, the old frozen_data | |
813 | * field now points to a committed version of the | |
814 | * buffer, so rotate that field to the new committed | |
815 | * data. | |
816 | * | |
817 | * Otherwise, we can just throw away the frozen data now. | |
818 | */ | |
819 | if (jh->b_committed_data) { | |
c089d490 | 820 | jbd_free(jh->b_committed_data, bh->b_size); |
1da177e4 LT |
821 | jh->b_committed_data = NULL; |
822 | if (jh->b_frozen_data) { | |
823 | jh->b_committed_data = jh->b_frozen_data; | |
824 | jh->b_frozen_data = NULL; | |
825 | } | |
826 | } else if (jh->b_frozen_data) { | |
c089d490 | 827 | jbd_free(jh->b_frozen_data, bh->b_size); |
1da177e4 LT |
828 | jh->b_frozen_data = NULL; |
829 | } | |
830 | ||
831 | spin_lock(&journal->j_list_lock); | |
832 | cp_transaction = jh->b_cp_transaction; | |
833 | if (cp_transaction) { | |
834 | JBUFFER_TRACE(jh, "remove from old cp transaction"); | |
835 | __journal_remove_checkpoint(jh); | |
836 | } | |
837 | ||
838 | /* Only re-checkpoint the buffer_head if it is marked | |
839 | * dirty. If the buffer was added to the BJ_Forget list | |
840 | * by journal_forget, it may no longer be dirty and | |
841 | * there's no point in keeping a checkpoint record for | |
842 | * it. */ | |
843 | ||
844 | /* A buffer which has been freed while still being | |
845 | * journaled by a previous transaction may end up still | |
846 | * being dirty here, but we want to avoid writing back | |
86963918 JK |
847 | * that buffer in the future after the "add to orphan" |
848 | * operation been committed, That's not only a performance | |
849 | * gain, it also stops aliasing problems if the buffer is | |
850 | * left behind for writeback and gets reallocated for another | |
1da177e4 | 851 | * use in a different page. */ |
86963918 | 852 | if (buffer_freed(bh) && !jh->b_next_transaction) { |
1da177e4 LT |
853 | clear_buffer_freed(bh); |
854 | clear_buffer_jbddirty(bh); | |
855 | } | |
856 | ||
857 | if (buffer_jbddirty(bh)) { | |
858 | JBUFFER_TRACE(jh, "add to new checkpointing trans"); | |
859 | __journal_insert_checkpoint(jh, commit_transaction); | |
885e353c HK |
860 | if (is_journal_aborted(journal)) |
861 | clear_buffer_jbddirty(bh); | |
1da177e4 LT |
862 | JBUFFER_TRACE(jh, "refile for checkpoint writeback"); |
863 | __journal_refile_buffer(jh); | |
864 | jbd_unlock_bh_state(bh); | |
865 | } else { | |
866 | J_ASSERT_BH(bh, !buffer_dirty(bh)); | |
9ada7340 JK |
867 | /* The buffer on BJ_Forget list and not jbddirty means |
868 | * it has been freed by this transaction and hence it | |
869 | * could not have been reallocated until this | |
870 | * transaction has committed. *BUT* it could be | |
871 | * reallocated once we have written all the data to | |
872 | * disk and before we process the buffer on BJ_Forget | |
873 | * list. */ | |
874 | JBUFFER_TRACE(jh, "refile or unfile freed buffer"); | |
875 | __journal_refile_buffer(jh); | |
876 | if (!jh->b_transaction) { | |
877 | jbd_unlock_bh_state(bh); | |
878 | /* needs a brelse */ | |
879 | journal_remove_journal_head(bh); | |
880 | release_buffer_page(bh); | |
881 | } else | |
882 | jbd_unlock_bh_state(bh); | |
1da177e4 | 883 | } |
e6c9f5c1 JK |
884 | cond_resched_lock(&journal->j_list_lock); |
885 | } | |
886 | spin_unlock(&journal->j_list_lock); | |
887 | /* | |
d4beaf4a JK |
888 | * This is a bit sleazy. We use j_list_lock to protect transition |
889 | * of a transaction into T_FINISHED state and calling | |
890 | * __journal_drop_transaction(). Otherwise we could race with | |
891 | * other checkpointing code processing the transaction... | |
e6c9f5c1 JK |
892 | */ |
893 | spin_lock(&journal->j_state_lock); | |
894 | spin_lock(&journal->j_list_lock); | |
895 | /* | |
896 | * Now recheck if some buffers did not get attached to the transaction | |
897 | * while the lock was dropped... | |
898 | */ | |
899 | if (commit_transaction->t_forget) { | |
1da177e4 | 900 | spin_unlock(&journal->j_list_lock); |
e6c9f5c1 JK |
901 | spin_unlock(&journal->j_state_lock); |
902 | goto restart_loop; | |
1da177e4 LT |
903 | } |
904 | ||
905 | /* Done with this transaction! */ | |
906 | ||
907 | jbd_debug(3, "JBD: commit phase 8\n"); | |
908 | ||
03f4d804 | 909 | J_ASSERT(commit_transaction->t_state == T_COMMIT_RECORD); |
1da177e4 | 910 | |
1da177e4 LT |
911 | commit_transaction->t_state = T_FINISHED; |
912 | J_ASSERT(commit_transaction == journal->j_committing_transaction); | |
913 | journal->j_commit_sequence = commit_transaction->t_tid; | |
914 | journal->j_committing_transaction = NULL; | |
f420d4dc JB |
915 | commit_time = ktime_to_ns(ktime_sub(ktime_get(), start_time)); |
916 | ||
917 | /* | |
918 | * weight the commit time higher than the average time so we don't | |
919 | * react too strongly to vast changes in commit time | |
920 | */ | |
921 | if (likely(journal->j_average_commit_time)) | |
922 | journal->j_average_commit_time = (commit_time*3 + | |
923 | journal->j_average_commit_time) / 4; | |
924 | else | |
925 | journal->j_average_commit_time = commit_time; | |
926 | ||
1da177e4 LT |
927 | spin_unlock(&journal->j_state_lock); |
928 | ||
fe28e42b JK |
929 | if (commit_transaction->t_checkpoint_list == NULL && |
930 | commit_transaction->t_checkpoint_io_list == NULL) { | |
1da177e4 LT |
931 | __journal_drop_transaction(journal, commit_transaction); |
932 | } else { | |
933 | if (journal->j_checkpoint_transactions == NULL) { | |
934 | journal->j_checkpoint_transactions = commit_transaction; | |
935 | commit_transaction->t_cpnext = commit_transaction; | |
936 | commit_transaction->t_cpprev = commit_transaction; | |
937 | } else { | |
938 | commit_transaction->t_cpnext = | |
939 | journal->j_checkpoint_transactions; | |
940 | commit_transaction->t_cpprev = | |
941 | commit_transaction->t_cpnext->t_cpprev; | |
942 | commit_transaction->t_cpnext->t_cpprev = | |
943 | commit_transaction; | |
944 | commit_transaction->t_cpprev->t_cpnext = | |
945 | commit_transaction; | |
946 | } | |
947 | } | |
948 | spin_unlock(&journal->j_list_lock); | |
949 | ||
950 | jbd_debug(1, "JBD: commit %d complete, head %d\n", | |
951 | journal->j_commit_sequence, journal->j_tail_sequence); | |
952 | ||
953 | wake_up(&journal->j_wait_done_commit); | |
954 | } |