Commit | Line | Data |
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470decc6 | 1 | /* |
58862699 | 2 | * linux/fs/jbd2/transaction.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 | * Generic filesystem transaction handling code; part of the ext2fs | |
13 | * journaling system. | |
14 | * | |
15 | * This file manages transactions (compound commits managed by the | |
16 | * journaling code) and handles (individual atomic operations by the | |
17 | * filesystem). | |
18 | */ | |
19 | ||
20 | #include <linux/time.h> | |
21 | #include <linux/fs.h> | |
f7f4bccb | 22 | #include <linux/jbd2.h> |
470decc6 DK |
23 | #include <linux/errno.h> |
24 | #include <linux/slab.h> | |
25 | #include <linux/timer.h> | |
470decc6 DK |
26 | #include <linux/mm.h> |
27 | #include <linux/highmem.h> | |
e07f7183 | 28 | #include <linux/hrtimer.h> |
47def826 TT |
29 | #include <linux/backing-dev.h> |
30 | #include <linux/module.h> | |
470decc6 | 31 | |
7ddae860 AB |
32 | static void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh); |
33 | ||
470decc6 | 34 | /* |
f7f4bccb | 35 | * jbd2_get_transaction: obtain a new transaction_t object. |
470decc6 DK |
36 | * |
37 | * Simply allocate and initialise a new transaction. Create it in | |
38 | * RUNNING state and add it to the current journal (which should not | |
39 | * have an existing running transaction: we only make a new transaction | |
40 | * once we have started to commit the old one). | |
41 | * | |
42 | * Preconditions: | |
43 | * The journal MUST be locked. We don't perform atomic mallocs on the | |
44 | * new transaction and we can't block without protecting against other | |
45 | * processes trying to touch the journal while it is in transition. | |
46 | * | |
470decc6 DK |
47 | */ |
48 | ||
49 | static transaction_t * | |
f7f4bccb | 50 | jbd2_get_transaction(journal_t *journal, transaction_t *transaction) |
470decc6 DK |
51 | { |
52 | transaction->t_journal = journal; | |
53 | transaction->t_state = T_RUNNING; | |
e07f7183 | 54 | transaction->t_start_time = ktime_get(); |
470decc6 DK |
55 | transaction->t_tid = journal->j_transaction_sequence++; |
56 | transaction->t_expires = jiffies + journal->j_commit_interval; | |
57 | spin_lock_init(&transaction->t_handle_lock); | |
a51dca9c TT |
58 | atomic_set(&transaction->t_updates, 0); |
59 | atomic_set(&transaction->t_outstanding_credits, 0); | |
8dd42046 | 60 | atomic_set(&transaction->t_handle_count, 0); |
c851ed54 | 61 | INIT_LIST_HEAD(&transaction->t_inode_list); |
3e624fc7 | 62 | INIT_LIST_HEAD(&transaction->t_private_list); |
470decc6 DK |
63 | |
64 | /* Set up the commit timer for the new transaction. */ | |
b1f485f2 | 65 | journal->j_commit_timer.expires = round_jiffies_up(transaction->t_expires); |
470decc6 DK |
66 | add_timer(&journal->j_commit_timer); |
67 | ||
68 | J_ASSERT(journal->j_running_transaction == NULL); | |
69 | journal->j_running_transaction = transaction; | |
8e85fb3f JL |
70 | transaction->t_max_wait = 0; |
71 | transaction->t_start = jiffies; | |
470decc6 DK |
72 | |
73 | return transaction; | |
74 | } | |
75 | ||
76 | /* | |
77 | * Handle management. | |
78 | * | |
79 | * A handle_t is an object which represents a single atomic update to a | |
80 | * filesystem, and which tracks all of the modifications which form part | |
81 | * of that one update. | |
82 | */ | |
83 | ||
84 | /* | |
85 | * start_this_handle: Given a handle, deal with any locking or stalling | |
86 | * needed to make sure that there is enough journal space for the handle | |
87 | * to begin. Attach the handle to a transaction and set up the | |
88 | * transaction's buffer credits. | |
89 | */ | |
90 | ||
47def826 TT |
91 | static int start_this_handle(journal_t *journal, handle_t *handle, |
92 | int gfp_mask) | |
470decc6 DK |
93 | { |
94 | transaction_t *transaction; | |
95 | int needed; | |
96 | int nblocks = handle->h_buffer_credits; | |
97 | transaction_t *new_transaction = NULL; | |
8e85fb3f | 98 | unsigned long ts = jiffies; |
470decc6 DK |
99 | |
100 | if (nblocks > journal->j_max_transaction_buffers) { | |
101 | printk(KERN_ERR "JBD: %s wants too many credits (%d > %d)\n", | |
102 | current->comm, nblocks, | |
103 | journal->j_max_transaction_buffers); | |
47def826 | 104 | return -ENOSPC; |
470decc6 DK |
105 | } |
106 | ||
107 | alloc_transaction: | |
108 | if (!journal->j_running_transaction) { | |
47def826 | 109 | new_transaction = kzalloc(sizeof(*new_transaction), gfp_mask); |
470decc6 | 110 | if (!new_transaction) { |
47def826 TT |
111 | /* |
112 | * If __GFP_FS is not present, then we may be | |
113 | * being called from inside the fs writeback | |
114 | * layer, so we MUST NOT fail. Since | |
115 | * __GFP_NOFAIL is going away, we will arrange | |
116 | * to retry the allocation ourselves. | |
117 | */ | |
118 | if ((gfp_mask & __GFP_FS) == 0) { | |
119 | congestion_wait(BLK_RW_ASYNC, HZ/50); | |
120 | goto alloc_transaction; | |
121 | } | |
122 | return -ENOMEM; | |
470decc6 | 123 | } |
470decc6 DK |
124 | } |
125 | ||
126 | jbd_debug(3, "New handle %p going live.\n", handle); | |
127 | ||
470decc6 DK |
128 | /* |
129 | * We need to hold j_state_lock until t_updates has been incremented, | |
130 | * for proper journal barrier handling | |
131 | */ | |
a931da6a TT |
132 | repeat: |
133 | read_lock(&journal->j_state_lock); | |
470decc6 | 134 | if (is_journal_aborted(journal) || |
f7f4bccb | 135 | (journal->j_errno != 0 && !(journal->j_flags & JBD2_ACK_ERR))) { |
a931da6a | 136 | read_unlock(&journal->j_state_lock); |
47def826 TT |
137 | kfree(new_transaction); |
138 | return -EROFS; | |
470decc6 DK |
139 | } |
140 | ||
141 | /* Wait on the journal's transaction barrier if necessary */ | |
142 | if (journal->j_barrier_count) { | |
a931da6a | 143 | read_unlock(&journal->j_state_lock); |
470decc6 DK |
144 | wait_event(journal->j_wait_transaction_locked, |
145 | journal->j_barrier_count == 0); | |
146 | goto repeat; | |
147 | } | |
148 | ||
149 | if (!journal->j_running_transaction) { | |
a931da6a TT |
150 | read_unlock(&journal->j_state_lock); |
151 | if (!new_transaction) | |
470decc6 | 152 | goto alloc_transaction; |
a931da6a TT |
153 | write_lock(&journal->j_state_lock); |
154 | if (!journal->j_running_transaction) { | |
155 | jbd2_get_transaction(journal, new_transaction); | |
156 | new_transaction = NULL; | |
470decc6 | 157 | } |
a931da6a TT |
158 | write_unlock(&journal->j_state_lock); |
159 | goto repeat; | |
470decc6 DK |
160 | } |
161 | ||
162 | transaction = journal->j_running_transaction; | |
163 | ||
164 | /* | |
165 | * If the current transaction is locked down for commit, wait for the | |
166 | * lock to be released. | |
167 | */ | |
168 | if (transaction->t_state == T_LOCKED) { | |
169 | DEFINE_WAIT(wait); | |
170 | ||
171 | prepare_to_wait(&journal->j_wait_transaction_locked, | |
172 | &wait, TASK_UNINTERRUPTIBLE); | |
a931da6a | 173 | read_unlock(&journal->j_state_lock); |
470decc6 DK |
174 | schedule(); |
175 | finish_wait(&journal->j_wait_transaction_locked, &wait); | |
176 | goto repeat; | |
177 | } | |
178 | ||
179 | /* | |
180 | * If there is not enough space left in the log to write all potential | |
181 | * buffers requested by this operation, we need to stall pending a log | |
182 | * checkpoint to free some more log space. | |
183 | */ | |
8dd42046 TT |
184 | needed = atomic_add_return(nblocks, |
185 | &transaction->t_outstanding_credits); | |
470decc6 DK |
186 | |
187 | if (needed > journal->j_max_transaction_buffers) { | |
188 | /* | |
189 | * If the current transaction is already too large, then start | |
190 | * to commit it: we can then go back and attach this handle to | |
191 | * a new transaction. | |
192 | */ | |
193 | DEFINE_WAIT(wait); | |
194 | ||
195 | jbd_debug(2, "Handle %p starting new commit...\n", handle); | |
8dd42046 | 196 | atomic_sub(nblocks, &transaction->t_outstanding_credits); |
470decc6 DK |
197 | prepare_to_wait(&journal->j_wait_transaction_locked, &wait, |
198 | TASK_UNINTERRUPTIBLE); | |
f7f4bccb | 199 | __jbd2_log_start_commit(journal, transaction->t_tid); |
a931da6a | 200 | read_unlock(&journal->j_state_lock); |
470decc6 DK |
201 | schedule(); |
202 | finish_wait(&journal->j_wait_transaction_locked, &wait); | |
203 | goto repeat; | |
204 | } | |
205 | ||
206 | /* | |
207 | * The commit code assumes that it can get enough log space | |
208 | * without forcing a checkpoint. This is *critical* for | |
209 | * correctness: a checkpoint of a buffer which is also | |
210 | * associated with a committing transaction creates a deadlock, | |
211 | * so commit simply cannot force through checkpoints. | |
212 | * | |
213 | * We must therefore ensure the necessary space in the journal | |
214 | * *before* starting to dirty potentially checkpointed buffers | |
215 | * in the new transaction. | |
216 | * | |
217 | * The worst part is, any transaction currently committing can | |
218 | * reduce the free space arbitrarily. Be careful to account for | |
219 | * those buffers when checkpointing. | |
220 | */ | |
221 | ||
222 | /* | |
223 | * @@@ AKPM: This seems rather over-defensive. We're giving commit | |
224 | * a _lot_ of headroom: 1/4 of the journal plus the size of | |
225 | * the committing transaction. Really, we only need to give it | |
226 | * committing_transaction->t_outstanding_credits plus "enough" for | |
227 | * the log control blocks. | |
228 | * Also, this test is inconsitent with the matching one in | |
f7f4bccb | 229 | * jbd2_journal_extend(). |
470decc6 | 230 | */ |
f7f4bccb | 231 | if (__jbd2_log_space_left(journal) < jbd_space_needed(journal)) { |
470decc6 | 232 | jbd_debug(2, "Handle %p waiting for checkpoint...\n", handle); |
8dd42046 | 233 | atomic_sub(nblocks, &transaction->t_outstanding_credits); |
a931da6a TT |
234 | read_unlock(&journal->j_state_lock); |
235 | write_lock(&journal->j_state_lock); | |
236 | if (__jbd2_log_space_left(journal) < jbd_space_needed(journal)) | |
237 | __jbd2_log_wait_for_space(journal); | |
238 | write_unlock(&journal->j_state_lock); | |
239 | goto repeat; | |
470decc6 DK |
240 | } |
241 | ||
242 | /* OK, account for the buffers that this operation expects to | |
8dd42046 TT |
243 | * use and add the handle to the running transaction. |
244 | * | |
245 | * In order for t_max_wait to be reliable, it must be | |
246 | * protected by a lock. But doing so will mean that | |
247 | * start_this_handle() can not be run in parallel on SMP | |
248 | * systems, which limits our scalability. So we only enable | |
249 | * it when debugging is enabled. We may want to use a | |
250 | * separate flag, eventually, so we can enable this | |
251 | * independently of debugging. | |
252 | */ | |
253 | #ifdef CONFIG_JBD2_DEBUG | |
254 | if (jbd2_journal_enable_debug && | |
255 | time_after(transaction->t_start, ts)) { | |
8e85fb3f | 256 | ts = jbd2_time_diff(ts, transaction->t_start); |
8dd42046 | 257 | spin_lock(&transaction->t_handle_lock); |
8e85fb3f JL |
258 | if (ts > transaction->t_max_wait) |
259 | transaction->t_max_wait = ts; | |
8dd42046 | 260 | spin_unlock(&transaction->t_handle_lock); |
8e85fb3f | 261 | } |
8dd42046 | 262 | #endif |
470decc6 | 263 | handle->h_transaction = transaction; |
a51dca9c | 264 | atomic_inc(&transaction->t_updates); |
8dd42046 | 265 | atomic_inc(&transaction->t_handle_count); |
470decc6 | 266 | jbd_debug(4, "Handle %p given %d credits (total %d, free %d)\n", |
a51dca9c TT |
267 | handle, nblocks, |
268 | atomic_read(&transaction->t_outstanding_credits), | |
f7f4bccb | 269 | __jbd2_log_space_left(journal)); |
a931da6a | 270 | read_unlock(&journal->j_state_lock); |
9599b0e5 JK |
271 | |
272 | lock_map_acquire(&handle->h_lockdep_map); | |
47def826 TT |
273 | kfree(new_transaction); |
274 | return 0; | |
470decc6 DK |
275 | } |
276 | ||
7b751066 MC |
277 | static struct lock_class_key jbd2_handle_key; |
278 | ||
470decc6 DK |
279 | /* Allocate a new handle. This should probably be in a slab... */ |
280 | static handle_t *new_handle(int nblocks) | |
281 | { | |
af1e76d6 | 282 | handle_t *handle = jbd2_alloc_handle(GFP_NOFS); |
470decc6 DK |
283 | if (!handle) |
284 | return NULL; | |
285 | memset(handle, 0, sizeof(*handle)); | |
286 | handle->h_buffer_credits = nblocks; | |
287 | handle->h_ref = 1; | |
288 | ||
7b751066 MC |
289 | lockdep_init_map(&handle->h_lockdep_map, "jbd2_handle", |
290 | &jbd2_handle_key, 0); | |
291 | ||
470decc6 DK |
292 | return handle; |
293 | } | |
294 | ||
295 | /** | |
f7f4bccb | 296 | * handle_t *jbd2_journal_start() - Obtain a new handle. |
470decc6 DK |
297 | * @journal: Journal to start transaction on. |
298 | * @nblocks: number of block buffer we might modify | |
299 | * | |
300 | * We make sure that the transaction can guarantee at least nblocks of | |
301 | * modified buffers in the log. We block until the log can guarantee | |
302 | * that much space. | |
303 | * | |
304 | * This function is visible to journal users (like ext3fs), so is not | |
305 | * called with the journal already locked. | |
306 | * | |
307 | * Return a pointer to a newly allocated handle, or NULL on failure | |
308 | */ | |
47def826 | 309 | handle_t *jbd2__journal_start(journal_t *journal, int nblocks, int gfp_mask) |
470decc6 DK |
310 | { |
311 | handle_t *handle = journal_current_handle(); | |
312 | int err; | |
313 | ||
314 | if (!journal) | |
315 | return ERR_PTR(-EROFS); | |
316 | ||
317 | if (handle) { | |
318 | J_ASSERT(handle->h_transaction->t_journal == journal); | |
319 | handle->h_ref++; | |
320 | return handle; | |
321 | } | |
322 | ||
323 | handle = new_handle(nblocks); | |
324 | if (!handle) | |
325 | return ERR_PTR(-ENOMEM); | |
326 | ||
327 | current->journal_info = handle; | |
328 | ||
47def826 | 329 | err = start_this_handle(journal, handle, gfp_mask); |
470decc6 | 330 | if (err < 0) { |
af1e76d6 | 331 | jbd2_free_handle(handle); |
470decc6 DK |
332 | current->journal_info = NULL; |
333 | handle = ERR_PTR(err); | |
7b751066 | 334 | goto out; |
470decc6 | 335 | } |
7b751066 | 336 | out: |
470decc6 DK |
337 | return handle; |
338 | } | |
47def826 TT |
339 | EXPORT_SYMBOL(jbd2__journal_start); |
340 | ||
341 | ||
342 | handle_t *jbd2_journal_start(journal_t *journal, int nblocks) | |
343 | { | |
344 | return jbd2__journal_start(journal, nblocks, GFP_NOFS); | |
345 | } | |
346 | EXPORT_SYMBOL(jbd2_journal_start); | |
347 | ||
470decc6 DK |
348 | |
349 | /** | |
f7f4bccb | 350 | * int jbd2_journal_extend() - extend buffer credits. |
470decc6 DK |
351 | * @handle: handle to 'extend' |
352 | * @nblocks: nr blocks to try to extend by. | |
353 | * | |
354 | * Some transactions, such as large extends and truncates, can be done | |
355 | * atomically all at once or in several stages. The operation requests | |
356 | * a credit for a number of buffer modications in advance, but can | |
357 | * extend its credit if it needs more. | |
358 | * | |
f7f4bccb | 359 | * jbd2_journal_extend tries to give the running handle more buffer credits. |
470decc6 DK |
360 | * It does not guarantee that allocation - this is a best-effort only. |
361 | * The calling process MUST be able to deal cleanly with a failure to | |
362 | * extend here. | |
363 | * | |
364 | * Return 0 on success, non-zero on failure. | |
365 | * | |
366 | * return code < 0 implies an error | |
367 | * return code > 0 implies normal transaction-full status. | |
368 | */ | |
f7f4bccb | 369 | int jbd2_journal_extend(handle_t *handle, int nblocks) |
470decc6 DK |
370 | { |
371 | transaction_t *transaction = handle->h_transaction; | |
372 | journal_t *journal = transaction->t_journal; | |
373 | int result; | |
374 | int wanted; | |
375 | ||
376 | result = -EIO; | |
377 | if (is_handle_aborted(handle)) | |
378 | goto out; | |
379 | ||
380 | result = 1; | |
381 | ||
a931da6a | 382 | read_lock(&journal->j_state_lock); |
470decc6 DK |
383 | |
384 | /* Don't extend a locked-down transaction! */ | |
385 | if (handle->h_transaction->t_state != T_RUNNING) { | |
386 | jbd_debug(3, "denied handle %p %d blocks: " | |
387 | "transaction not running\n", handle, nblocks); | |
388 | goto error_out; | |
389 | } | |
390 | ||
391 | spin_lock(&transaction->t_handle_lock); | |
a51dca9c | 392 | wanted = atomic_read(&transaction->t_outstanding_credits) + nblocks; |
470decc6 DK |
393 | |
394 | if (wanted > journal->j_max_transaction_buffers) { | |
395 | jbd_debug(3, "denied handle %p %d blocks: " | |
396 | "transaction too large\n", handle, nblocks); | |
397 | goto unlock; | |
398 | } | |
399 | ||
f7f4bccb | 400 | if (wanted > __jbd2_log_space_left(journal)) { |
470decc6 DK |
401 | jbd_debug(3, "denied handle %p %d blocks: " |
402 | "insufficient log space\n", handle, nblocks); | |
403 | goto unlock; | |
404 | } | |
405 | ||
406 | handle->h_buffer_credits += nblocks; | |
a51dca9c | 407 | atomic_add(nblocks, &transaction->t_outstanding_credits); |
470decc6 DK |
408 | result = 0; |
409 | ||
410 | jbd_debug(3, "extended handle %p by %d\n", handle, nblocks); | |
411 | unlock: | |
412 | spin_unlock(&transaction->t_handle_lock); | |
413 | error_out: | |
a931da6a | 414 | read_unlock(&journal->j_state_lock); |
470decc6 DK |
415 | out: |
416 | return result; | |
417 | } | |
418 | ||
419 | ||
420 | /** | |
f7f4bccb | 421 | * int jbd2_journal_restart() - restart a handle . |
470decc6 DK |
422 | * @handle: handle to restart |
423 | * @nblocks: nr credits requested | |
424 | * | |
425 | * Restart a handle for a multi-transaction filesystem | |
426 | * operation. | |
427 | * | |
f7f4bccb MC |
428 | * If the jbd2_journal_extend() call above fails to grant new buffer credits |
429 | * to a running handle, a call to jbd2_journal_restart will commit the | |
470decc6 DK |
430 | * handle's transaction so far and reattach the handle to a new |
431 | * transaction capabable of guaranteeing the requested number of | |
432 | * credits. | |
433 | */ | |
47def826 | 434 | int jbd2__journal_restart(handle_t *handle, int nblocks, int gfp_mask) |
470decc6 DK |
435 | { |
436 | transaction_t *transaction = handle->h_transaction; | |
437 | journal_t *journal = transaction->t_journal; | |
438 | int ret; | |
439 | ||
440 | /* If we've had an abort of any type, don't even think about | |
441 | * actually doing the restart! */ | |
442 | if (is_handle_aborted(handle)) | |
443 | return 0; | |
444 | ||
445 | /* | |
446 | * First unlink the handle from its current transaction, and start the | |
447 | * commit on that. | |
448 | */ | |
a51dca9c | 449 | J_ASSERT(atomic_read(&transaction->t_updates) > 0); |
470decc6 DK |
450 | J_ASSERT(journal_current_handle() == handle); |
451 | ||
a931da6a | 452 | read_lock(&journal->j_state_lock); |
470decc6 | 453 | spin_lock(&transaction->t_handle_lock); |
a51dca9c TT |
454 | atomic_sub(handle->h_buffer_credits, |
455 | &transaction->t_outstanding_credits); | |
456 | if (atomic_dec_and_test(&transaction->t_updates)) | |
470decc6 DK |
457 | wake_up(&journal->j_wait_updates); |
458 | spin_unlock(&transaction->t_handle_lock); | |
459 | ||
460 | jbd_debug(2, "restarting handle %p\n", handle); | |
f7f4bccb | 461 | __jbd2_log_start_commit(journal, transaction->t_tid); |
a931da6a | 462 | read_unlock(&journal->j_state_lock); |
470decc6 | 463 | |
9599b0e5 | 464 | lock_map_release(&handle->h_lockdep_map); |
470decc6 | 465 | handle->h_buffer_credits = nblocks; |
47def826 | 466 | ret = start_this_handle(journal, handle, gfp_mask); |
470decc6 DK |
467 | return ret; |
468 | } | |
47def826 | 469 | EXPORT_SYMBOL(jbd2__journal_restart); |
470decc6 DK |
470 | |
471 | ||
47def826 TT |
472 | int jbd2_journal_restart(handle_t *handle, int nblocks) |
473 | { | |
474 | return jbd2__journal_restart(handle, nblocks, GFP_NOFS); | |
475 | } | |
476 | EXPORT_SYMBOL(jbd2_journal_restart); | |
477 | ||
470decc6 | 478 | /** |
f7f4bccb | 479 | * void jbd2_journal_lock_updates () - establish a transaction barrier. |
470decc6 DK |
480 | * @journal: Journal to establish a barrier on. |
481 | * | |
482 | * This locks out any further updates from being started, and blocks | |
483 | * until all existing updates have completed, returning only once the | |
484 | * journal is in a quiescent state with no updates running. | |
485 | * | |
486 | * The journal lock should not be held on entry. | |
487 | */ | |
f7f4bccb | 488 | void jbd2_journal_lock_updates(journal_t *journal) |
470decc6 DK |
489 | { |
490 | DEFINE_WAIT(wait); | |
491 | ||
a931da6a | 492 | write_lock(&journal->j_state_lock); |
470decc6 DK |
493 | ++journal->j_barrier_count; |
494 | ||
495 | /* Wait until there are no running updates */ | |
496 | while (1) { | |
497 | transaction_t *transaction = journal->j_running_transaction; | |
498 | ||
499 | if (!transaction) | |
500 | break; | |
501 | ||
502 | spin_lock(&transaction->t_handle_lock); | |
a51dca9c | 503 | if (!atomic_read(&transaction->t_updates)) { |
470decc6 DK |
504 | spin_unlock(&transaction->t_handle_lock); |
505 | break; | |
506 | } | |
507 | prepare_to_wait(&journal->j_wait_updates, &wait, | |
508 | TASK_UNINTERRUPTIBLE); | |
509 | spin_unlock(&transaction->t_handle_lock); | |
a931da6a | 510 | write_unlock(&journal->j_state_lock); |
470decc6 DK |
511 | schedule(); |
512 | finish_wait(&journal->j_wait_updates, &wait); | |
a931da6a | 513 | write_lock(&journal->j_state_lock); |
470decc6 | 514 | } |
a931da6a | 515 | write_unlock(&journal->j_state_lock); |
470decc6 DK |
516 | |
517 | /* | |
518 | * We have now established a barrier against other normal updates, but | |
f7f4bccb | 519 | * we also need to barrier against other jbd2_journal_lock_updates() calls |
470decc6 DK |
520 | * to make sure that we serialise special journal-locked operations |
521 | * too. | |
522 | */ | |
523 | mutex_lock(&journal->j_barrier); | |
524 | } | |
525 | ||
526 | /** | |
f7f4bccb | 527 | * void jbd2_journal_unlock_updates (journal_t* journal) - release barrier |
470decc6 DK |
528 | * @journal: Journal to release the barrier on. |
529 | * | |
f7f4bccb | 530 | * Release a transaction barrier obtained with jbd2_journal_lock_updates(). |
470decc6 DK |
531 | * |
532 | * Should be called without the journal lock held. | |
533 | */ | |
f7f4bccb | 534 | void jbd2_journal_unlock_updates (journal_t *journal) |
470decc6 DK |
535 | { |
536 | J_ASSERT(journal->j_barrier_count != 0); | |
537 | ||
538 | mutex_unlock(&journal->j_barrier); | |
a931da6a | 539 | write_lock(&journal->j_state_lock); |
470decc6 | 540 | --journal->j_barrier_count; |
a931da6a | 541 | write_unlock(&journal->j_state_lock); |
470decc6 DK |
542 | wake_up(&journal->j_wait_transaction_locked); |
543 | } | |
544 | ||
f91d1d04 | 545 | static void warn_dirty_buffer(struct buffer_head *bh) |
470decc6 | 546 | { |
f91d1d04 | 547 | char b[BDEVNAME_SIZE]; |
470decc6 | 548 | |
f91d1d04 JK |
549 | printk(KERN_WARNING |
550 | "JBD: Spotted dirty metadata buffer (dev = %s, blocknr = %llu). " | |
551 | "There's a risk of filesystem corruption in case of system " | |
552 | "crash.\n", | |
553 | bdevname(bh->b_bdev, b), (unsigned long long)bh->b_blocknr); | |
470decc6 DK |
554 | } |
555 | ||
556 | /* | |
557 | * If the buffer is already part of the current transaction, then there | |
558 | * is nothing we need to do. If it is already part of a prior | |
559 | * transaction which we are still committing to disk, then we need to | |
560 | * make sure that we do not overwrite the old copy: we do copy-out to | |
561 | * preserve the copy going to disk. We also account the buffer against | |
562 | * the handle's metadata buffer credits (unless the buffer is already | |
563 | * part of the transaction, that is). | |
564 | * | |
565 | */ | |
566 | static int | |
567 | do_get_write_access(handle_t *handle, struct journal_head *jh, | |
568 | int force_copy) | |
569 | { | |
570 | struct buffer_head *bh; | |
571 | transaction_t *transaction; | |
572 | journal_t *journal; | |
573 | int error; | |
574 | char *frozen_buffer = NULL; | |
575 | int need_copy = 0; | |
576 | ||
577 | if (is_handle_aborted(handle)) | |
578 | return -EROFS; | |
579 | ||
580 | transaction = handle->h_transaction; | |
581 | journal = transaction->t_journal; | |
582 | ||
583 | jbd_debug(5, "buffer_head %p, force_copy %d\n", jh, force_copy); | |
584 | ||
585 | JBUFFER_TRACE(jh, "entry"); | |
586 | repeat: | |
587 | bh = jh2bh(jh); | |
588 | ||
589 | /* @@@ Need to check for errors here at some point. */ | |
590 | ||
591 | lock_buffer(bh); | |
592 | jbd_lock_bh_state(bh); | |
593 | ||
594 | /* We now hold the buffer lock so it is safe to query the buffer | |
595 | * state. Is the buffer dirty? | |
596 | * | |
597 | * If so, there are two possibilities. The buffer may be | |
598 | * non-journaled, and undergoing a quite legitimate writeback. | |
599 | * Otherwise, it is journaled, and we don't expect dirty buffers | |
600 | * in that state (the buffers should be marked JBD_Dirty | |
601 | * instead.) So either the IO is being done under our own | |
602 | * control and this is a bug, or it's a third party IO such as | |
603 | * dump(8) (which may leave the buffer scheduled for read --- | |
604 | * ie. locked but not dirty) or tune2fs (which may actually have | |
605 | * the buffer dirtied, ugh.) */ | |
606 | ||
607 | if (buffer_dirty(bh)) { | |
608 | /* | |
609 | * First question: is this buffer already part of the current | |
610 | * transaction or the existing committing transaction? | |
611 | */ | |
612 | if (jh->b_transaction) { | |
613 | J_ASSERT_JH(jh, | |
614 | jh->b_transaction == transaction || | |
615 | jh->b_transaction == | |
616 | journal->j_committing_transaction); | |
617 | if (jh->b_next_transaction) | |
618 | J_ASSERT_JH(jh, jh->b_next_transaction == | |
619 | transaction); | |
f91d1d04 | 620 | warn_dirty_buffer(bh); |
470decc6 DK |
621 | } |
622 | /* | |
623 | * In any case we need to clean the dirty flag and we must | |
624 | * do it under the buffer lock to be sure we don't race | |
625 | * with running write-out. | |
626 | */ | |
f91d1d04 JK |
627 | JBUFFER_TRACE(jh, "Journalling dirty buffer"); |
628 | clear_buffer_dirty(bh); | |
629 | set_buffer_jbddirty(bh); | |
470decc6 DK |
630 | } |
631 | ||
632 | unlock_buffer(bh); | |
633 | ||
634 | error = -EROFS; | |
635 | if (is_handle_aborted(handle)) { | |
636 | jbd_unlock_bh_state(bh); | |
637 | goto out; | |
638 | } | |
639 | error = 0; | |
640 | ||
641 | /* | |
642 | * The buffer is already part of this transaction if b_transaction or | |
643 | * b_next_transaction points to it | |
644 | */ | |
645 | if (jh->b_transaction == transaction || | |
646 | jh->b_next_transaction == transaction) | |
647 | goto done; | |
648 | ||
9fc7c63a JB |
649 | /* |
650 | * this is the first time this transaction is touching this buffer, | |
651 | * reset the modified flag | |
652 | */ | |
653 | jh->b_modified = 0; | |
654 | ||
470decc6 DK |
655 | /* |
656 | * If there is already a copy-out version of this buffer, then we don't | |
657 | * need to make another one | |
658 | */ | |
659 | if (jh->b_frozen_data) { | |
660 | JBUFFER_TRACE(jh, "has frozen data"); | |
661 | J_ASSERT_JH(jh, jh->b_next_transaction == NULL); | |
662 | jh->b_next_transaction = transaction; | |
663 | goto done; | |
664 | } | |
665 | ||
666 | /* Is there data here we need to preserve? */ | |
667 | ||
668 | if (jh->b_transaction && jh->b_transaction != transaction) { | |
669 | JBUFFER_TRACE(jh, "owned by older transaction"); | |
670 | J_ASSERT_JH(jh, jh->b_next_transaction == NULL); | |
671 | J_ASSERT_JH(jh, jh->b_transaction == | |
672 | journal->j_committing_transaction); | |
673 | ||
674 | /* There is one case we have to be very careful about. | |
675 | * If the committing transaction is currently writing | |
676 | * this buffer out to disk and has NOT made a copy-out, | |
677 | * then we cannot modify the buffer contents at all | |
678 | * right now. The essence of copy-out is that it is the | |
679 | * extra copy, not the primary copy, which gets | |
680 | * journaled. If the primary copy is already going to | |
681 | * disk then we cannot do copy-out here. */ | |
682 | ||
683 | if (jh->b_jlist == BJ_Shadow) { | |
684 | DEFINE_WAIT_BIT(wait, &bh->b_state, BH_Unshadow); | |
685 | wait_queue_head_t *wqh; | |
686 | ||
687 | wqh = bit_waitqueue(&bh->b_state, BH_Unshadow); | |
688 | ||
689 | JBUFFER_TRACE(jh, "on shadow: sleep"); | |
690 | jbd_unlock_bh_state(bh); | |
691 | /* commit wakes up all shadow buffers after IO */ | |
692 | for ( ; ; ) { | |
693 | prepare_to_wait(wqh, &wait.wait, | |
694 | TASK_UNINTERRUPTIBLE); | |
695 | if (jh->b_jlist != BJ_Shadow) | |
696 | break; | |
697 | schedule(); | |
698 | } | |
699 | finish_wait(wqh, &wait.wait); | |
700 | goto repeat; | |
701 | } | |
702 | ||
703 | /* Only do the copy if the currently-owning transaction | |
704 | * still needs it. If it is on the Forget list, the | |
705 | * committing transaction is past that stage. The | |
706 | * buffer had better remain locked during the kmalloc, | |
707 | * but that should be true --- we hold the journal lock | |
708 | * still and the buffer is already on the BUF_JOURNAL | |
709 | * list so won't be flushed. | |
710 | * | |
711 | * Subtle point, though: if this is a get_undo_access, | |
712 | * then we will be relying on the frozen_data to contain | |
713 | * the new value of the committed_data record after the | |
714 | * transaction, so we HAVE to force the frozen_data copy | |
715 | * in that case. */ | |
716 | ||
717 | if (jh->b_jlist != BJ_Forget || force_copy) { | |
718 | JBUFFER_TRACE(jh, "generate frozen data"); | |
719 | if (!frozen_buffer) { | |
720 | JBUFFER_TRACE(jh, "allocate memory for buffer"); | |
721 | jbd_unlock_bh_state(bh); | |
722 | frozen_buffer = | |
af1e76d6 | 723 | jbd2_alloc(jh2bh(jh)->b_size, |
470decc6 DK |
724 | GFP_NOFS); |
725 | if (!frozen_buffer) { | |
726 | printk(KERN_EMERG | |
727 | "%s: OOM for frozen_buffer\n", | |
329d291f | 728 | __func__); |
470decc6 DK |
729 | JBUFFER_TRACE(jh, "oom!"); |
730 | error = -ENOMEM; | |
731 | jbd_lock_bh_state(bh); | |
732 | goto done; | |
733 | } | |
734 | goto repeat; | |
735 | } | |
736 | jh->b_frozen_data = frozen_buffer; | |
737 | frozen_buffer = NULL; | |
738 | need_copy = 1; | |
739 | } | |
740 | jh->b_next_transaction = transaction; | |
741 | } | |
742 | ||
743 | ||
744 | /* | |
745 | * Finally, if the buffer is not journaled right now, we need to make | |
746 | * sure it doesn't get written to disk before the caller actually | |
747 | * commits the new data | |
748 | */ | |
749 | if (!jh->b_transaction) { | |
750 | JBUFFER_TRACE(jh, "no transaction"); | |
751 | J_ASSERT_JH(jh, !jh->b_next_transaction); | |
752 | jh->b_transaction = transaction; | |
753 | JBUFFER_TRACE(jh, "file as BJ_Reserved"); | |
754 | spin_lock(&journal->j_list_lock); | |
f7f4bccb | 755 | __jbd2_journal_file_buffer(jh, transaction, BJ_Reserved); |
470decc6 DK |
756 | spin_unlock(&journal->j_list_lock); |
757 | } | |
758 | ||
759 | done: | |
760 | if (need_copy) { | |
761 | struct page *page; | |
762 | int offset; | |
763 | char *source; | |
764 | ||
765 | J_EXPECT_JH(jh, buffer_uptodate(jh2bh(jh)), | |
766 | "Possible IO failure.\n"); | |
767 | page = jh2bh(jh)->b_page; | |
768 | offset = ((unsigned long) jh2bh(jh)->b_data) & ~PAGE_MASK; | |
769 | source = kmap_atomic(page, KM_USER0); | |
13ceef09 JK |
770 | /* Fire data frozen trigger just before we copy the data */ |
771 | jbd2_buffer_frozen_trigger(jh, source + offset, | |
772 | jh->b_triggers); | |
470decc6 DK |
773 | memcpy(jh->b_frozen_data, source+offset, jh2bh(jh)->b_size); |
774 | kunmap_atomic(source, KM_USER0); | |
e06c8227 JB |
775 | |
776 | /* | |
777 | * Now that the frozen data is saved off, we need to store | |
778 | * any matching triggers. | |
779 | */ | |
780 | jh->b_frozen_triggers = jh->b_triggers; | |
470decc6 DK |
781 | } |
782 | jbd_unlock_bh_state(bh); | |
783 | ||
784 | /* | |
785 | * If we are about to journal a buffer, then any revoke pending on it is | |
786 | * no longer valid | |
787 | */ | |
f7f4bccb | 788 | jbd2_journal_cancel_revoke(handle, jh); |
470decc6 DK |
789 | |
790 | out: | |
791 | if (unlikely(frozen_buffer)) /* It's usually NULL */ | |
af1e76d6 | 792 | jbd2_free(frozen_buffer, bh->b_size); |
470decc6 DK |
793 | |
794 | JBUFFER_TRACE(jh, "exit"); | |
795 | return error; | |
796 | } | |
797 | ||
798 | /** | |
f7f4bccb | 799 | * int jbd2_journal_get_write_access() - notify intent to modify a buffer for metadata (not data) update. |
470decc6 DK |
800 | * @handle: transaction to add buffer modifications to |
801 | * @bh: bh to be used for metadata writes | |
802 | * @credits: variable that will receive credits for the buffer | |
803 | * | |
804 | * Returns an error code or 0 on success. | |
805 | * | |
806 | * In full data journalling mode the buffer may be of type BJ_AsyncData, | |
807 | * because we're write()ing a buffer which is also part of a shared mapping. | |
808 | */ | |
809 | ||
f7f4bccb | 810 | int jbd2_journal_get_write_access(handle_t *handle, struct buffer_head *bh) |
470decc6 | 811 | { |
f7f4bccb | 812 | struct journal_head *jh = jbd2_journal_add_journal_head(bh); |
470decc6 DK |
813 | int rc; |
814 | ||
815 | /* We do not want to get caught playing with fields which the | |
816 | * log thread also manipulates. Make sure that the buffer | |
817 | * completes any outstanding IO before proceeding. */ | |
818 | rc = do_get_write_access(handle, jh, 0); | |
f7f4bccb | 819 | jbd2_journal_put_journal_head(jh); |
470decc6 DK |
820 | return rc; |
821 | } | |
822 | ||
823 | ||
824 | /* | |
825 | * When the user wants to journal a newly created buffer_head | |
826 | * (ie. getblk() returned a new buffer and we are going to populate it | |
827 | * manually rather than reading off disk), then we need to keep the | |
828 | * buffer_head locked until it has been completely filled with new | |
829 | * data. In this case, we should be able to make the assertion that | |
830 | * the bh is not already part of an existing transaction. | |
831 | * | |
832 | * The buffer should already be locked by the caller by this point. | |
833 | * There is no lock ranking violation: it was a newly created, | |
834 | * unlocked buffer beforehand. */ | |
835 | ||
836 | /** | |
f7f4bccb | 837 | * int jbd2_journal_get_create_access () - notify intent to use newly created bh |
470decc6 DK |
838 | * @handle: transaction to new buffer to |
839 | * @bh: new buffer. | |
840 | * | |
841 | * Call this if you create a new bh. | |
842 | */ | |
f7f4bccb | 843 | int jbd2_journal_get_create_access(handle_t *handle, struct buffer_head *bh) |
470decc6 DK |
844 | { |
845 | transaction_t *transaction = handle->h_transaction; | |
846 | journal_t *journal = transaction->t_journal; | |
f7f4bccb | 847 | struct journal_head *jh = jbd2_journal_add_journal_head(bh); |
470decc6 DK |
848 | int err; |
849 | ||
850 | jbd_debug(5, "journal_head %p\n", jh); | |
851 | err = -EROFS; | |
852 | if (is_handle_aborted(handle)) | |
853 | goto out; | |
854 | err = 0; | |
855 | ||
856 | JBUFFER_TRACE(jh, "entry"); | |
857 | /* | |
858 | * The buffer may already belong to this transaction due to pre-zeroing | |
859 | * in the filesystem's new_block code. It may also be on the previous, | |
860 | * committing transaction's lists, but it HAS to be in Forget state in | |
861 | * that case: the transaction must have deleted the buffer for it to be | |
862 | * reused here. | |
863 | */ | |
864 | jbd_lock_bh_state(bh); | |
865 | spin_lock(&journal->j_list_lock); | |
866 | J_ASSERT_JH(jh, (jh->b_transaction == transaction || | |
867 | jh->b_transaction == NULL || | |
868 | (jh->b_transaction == journal->j_committing_transaction && | |
869 | jh->b_jlist == BJ_Forget))); | |
870 | ||
871 | J_ASSERT_JH(jh, jh->b_next_transaction == NULL); | |
872 | J_ASSERT_JH(jh, buffer_locked(jh2bh(jh))); | |
873 | ||
874 | if (jh->b_transaction == NULL) { | |
f91d1d04 JK |
875 | /* |
876 | * Previous jbd2_journal_forget() could have left the buffer | |
877 | * with jbddirty bit set because it was being committed. When | |
878 | * the commit finished, we've filed the buffer for | |
879 | * checkpointing and marked it dirty. Now we are reallocating | |
880 | * the buffer so the transaction freeing it must have | |
881 | * committed and so it's safe to clear the dirty bit. | |
882 | */ | |
883 | clear_buffer_dirty(jh2bh(jh)); | |
470decc6 | 884 | jh->b_transaction = transaction; |
9fc7c63a JB |
885 | |
886 | /* first access by this transaction */ | |
887 | jh->b_modified = 0; | |
888 | ||
470decc6 | 889 | JBUFFER_TRACE(jh, "file as BJ_Reserved"); |
f7f4bccb | 890 | __jbd2_journal_file_buffer(jh, transaction, BJ_Reserved); |
470decc6 | 891 | } else if (jh->b_transaction == journal->j_committing_transaction) { |
9fc7c63a JB |
892 | /* first access by this transaction */ |
893 | jh->b_modified = 0; | |
894 | ||
470decc6 DK |
895 | JBUFFER_TRACE(jh, "set next transaction"); |
896 | jh->b_next_transaction = transaction; | |
897 | } | |
898 | spin_unlock(&journal->j_list_lock); | |
899 | jbd_unlock_bh_state(bh); | |
900 | ||
901 | /* | |
902 | * akpm: I added this. ext3_alloc_branch can pick up new indirect | |
903 | * blocks which contain freed but then revoked metadata. We need | |
904 | * to cancel the revoke in case we end up freeing it yet again | |
905 | * and the reallocating as data - this would cause a second revoke, | |
906 | * which hits an assertion error. | |
907 | */ | |
908 | JBUFFER_TRACE(jh, "cancelling revoke"); | |
f7f4bccb MC |
909 | jbd2_journal_cancel_revoke(handle, jh); |
910 | jbd2_journal_put_journal_head(jh); | |
470decc6 DK |
911 | out: |
912 | return err; | |
913 | } | |
914 | ||
915 | /** | |
f7f4bccb | 916 | * int jbd2_journal_get_undo_access() - Notify intent to modify metadata with |
470decc6 DK |
917 | * non-rewindable consequences |
918 | * @handle: transaction | |
919 | * @bh: buffer to undo | |
920 | * @credits: store the number of taken credits here (if not NULL) | |
921 | * | |
922 | * Sometimes there is a need to distinguish between metadata which has | |
923 | * been committed to disk and that which has not. The ext3fs code uses | |
924 | * this for freeing and allocating space, we have to make sure that we | |
925 | * do not reuse freed space until the deallocation has been committed, | |
926 | * since if we overwrote that space we would make the delete | |
927 | * un-rewindable in case of a crash. | |
928 | * | |
f7f4bccb | 929 | * To deal with that, jbd2_journal_get_undo_access requests write access to a |
470decc6 DK |
930 | * buffer for parts of non-rewindable operations such as delete |
931 | * operations on the bitmaps. The journaling code must keep a copy of | |
932 | * the buffer's contents prior to the undo_access call until such time | |
933 | * as we know that the buffer has definitely been committed to disk. | |
934 | * | |
935 | * We never need to know which transaction the committed data is part | |
936 | * of, buffers touched here are guaranteed to be dirtied later and so | |
937 | * will be committed to a new transaction in due course, at which point | |
938 | * we can discard the old committed data pointer. | |
939 | * | |
940 | * Returns error number or 0 on success. | |
941 | */ | |
f7f4bccb | 942 | int jbd2_journal_get_undo_access(handle_t *handle, struct buffer_head *bh) |
470decc6 DK |
943 | { |
944 | int err; | |
f7f4bccb | 945 | struct journal_head *jh = jbd2_journal_add_journal_head(bh); |
470decc6 DK |
946 | char *committed_data = NULL; |
947 | ||
948 | JBUFFER_TRACE(jh, "entry"); | |
949 | ||
950 | /* | |
951 | * Do this first --- it can drop the journal lock, so we want to | |
952 | * make sure that obtaining the committed_data is done | |
953 | * atomically wrt. completion of any outstanding commits. | |
954 | */ | |
955 | err = do_get_write_access(handle, jh, 1); | |
956 | if (err) | |
957 | goto out; | |
958 | ||
959 | repeat: | |
960 | if (!jh->b_committed_data) { | |
af1e76d6 | 961 | committed_data = jbd2_alloc(jh2bh(jh)->b_size, GFP_NOFS); |
470decc6 DK |
962 | if (!committed_data) { |
963 | printk(KERN_EMERG "%s: No memory for committed data\n", | |
329d291f | 964 | __func__); |
470decc6 DK |
965 | err = -ENOMEM; |
966 | goto out; | |
967 | } | |
968 | } | |
969 | ||
970 | jbd_lock_bh_state(bh); | |
971 | if (!jh->b_committed_data) { | |
972 | /* Copy out the current buffer contents into the | |
973 | * preserved, committed copy. */ | |
974 | JBUFFER_TRACE(jh, "generate b_committed data"); | |
975 | if (!committed_data) { | |
976 | jbd_unlock_bh_state(bh); | |
977 | goto repeat; | |
978 | } | |
979 | ||
980 | jh->b_committed_data = committed_data; | |
981 | committed_data = NULL; | |
982 | memcpy(jh->b_committed_data, bh->b_data, bh->b_size); | |
983 | } | |
984 | jbd_unlock_bh_state(bh); | |
985 | out: | |
f7f4bccb | 986 | jbd2_journal_put_journal_head(jh); |
470decc6 | 987 | if (unlikely(committed_data)) |
af1e76d6 | 988 | jbd2_free(committed_data, bh->b_size); |
470decc6 DK |
989 | return err; |
990 | } | |
991 | ||
e06c8227 JB |
992 | /** |
993 | * void jbd2_journal_set_triggers() - Add triggers for commit writeout | |
994 | * @bh: buffer to trigger on | |
995 | * @type: struct jbd2_buffer_trigger_type containing the trigger(s). | |
996 | * | |
997 | * Set any triggers on this journal_head. This is always safe, because | |
998 | * triggers for a committing buffer will be saved off, and triggers for | |
999 | * a running transaction will match the buffer in that transaction. | |
1000 | * | |
1001 | * Call with NULL to clear the triggers. | |
1002 | */ | |
1003 | void jbd2_journal_set_triggers(struct buffer_head *bh, | |
1004 | struct jbd2_buffer_trigger_type *type) | |
1005 | { | |
1006 | struct journal_head *jh = bh2jh(bh); | |
1007 | ||
1008 | jh->b_triggers = type; | |
1009 | } | |
1010 | ||
13ceef09 | 1011 | void jbd2_buffer_frozen_trigger(struct journal_head *jh, void *mapped_data, |
e06c8227 JB |
1012 | struct jbd2_buffer_trigger_type *triggers) |
1013 | { | |
1014 | struct buffer_head *bh = jh2bh(jh); | |
1015 | ||
13ceef09 | 1016 | if (!triggers || !triggers->t_frozen) |
e06c8227 JB |
1017 | return; |
1018 | ||
13ceef09 | 1019 | triggers->t_frozen(triggers, bh, mapped_data, bh->b_size); |
e06c8227 JB |
1020 | } |
1021 | ||
1022 | void jbd2_buffer_abort_trigger(struct journal_head *jh, | |
1023 | struct jbd2_buffer_trigger_type *triggers) | |
1024 | { | |
1025 | if (!triggers || !triggers->t_abort) | |
1026 | return; | |
1027 | ||
1028 | triggers->t_abort(triggers, jh2bh(jh)); | |
1029 | } | |
1030 | ||
1031 | ||
1032 | ||
470decc6 | 1033 | /** |
f7f4bccb | 1034 | * int jbd2_journal_dirty_metadata() - mark a buffer as containing dirty metadata |
470decc6 DK |
1035 | * @handle: transaction to add buffer to. |
1036 | * @bh: buffer to mark | |
1037 | * | |
1038 | * mark dirty metadata which needs to be journaled as part of the current | |
1039 | * transaction. | |
1040 | * | |
1041 | * The buffer is placed on the transaction's metadata list and is marked | |
1042 | * as belonging to the transaction. | |
1043 | * | |
1044 | * Returns error number or 0 on success. | |
1045 | * | |
1046 | * Special care needs to be taken if the buffer already belongs to the | |
1047 | * current committing transaction (in which case we should have frozen | |
1048 | * data present for that commit). In that case, we don't relink the | |
1049 | * buffer: that only gets done when the old transaction finally | |
1050 | * completes its commit. | |
1051 | */ | |
f7f4bccb | 1052 | int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh) |
470decc6 DK |
1053 | { |
1054 | transaction_t *transaction = handle->h_transaction; | |
1055 | journal_t *journal = transaction->t_journal; | |
1056 | struct journal_head *jh = bh2jh(bh); | |
1057 | ||
1058 | jbd_debug(5, "journal_head %p\n", jh); | |
1059 | JBUFFER_TRACE(jh, "entry"); | |
1060 | if (is_handle_aborted(handle)) | |
1061 | goto out; | |
1062 | ||
1063 | jbd_lock_bh_state(bh); | |
1064 | ||
1065 | if (jh->b_modified == 0) { | |
1066 | /* | |
1067 | * This buffer's got modified and becoming part | |
1068 | * of the transaction. This needs to be done | |
1069 | * once a transaction -bzzz | |
1070 | */ | |
1071 | jh->b_modified = 1; | |
1072 | J_ASSERT_JH(jh, handle->h_buffer_credits > 0); | |
1073 | handle->h_buffer_credits--; | |
1074 | } | |
1075 | ||
1076 | /* | |
1077 | * fastpath, to avoid expensive locking. If this buffer is already | |
1078 | * on the running transaction's metadata list there is nothing to do. | |
1079 | * Nobody can take it off again because there is a handle open. | |
1080 | * I _think_ we're OK here with SMP barriers - a mistaken decision will | |
1081 | * result in this test being false, so we go in and take the locks. | |
1082 | */ | |
1083 | if (jh->b_transaction == transaction && jh->b_jlist == BJ_Metadata) { | |
1084 | JBUFFER_TRACE(jh, "fastpath"); | |
1085 | J_ASSERT_JH(jh, jh->b_transaction == | |
1086 | journal->j_running_transaction); | |
1087 | goto out_unlock_bh; | |
1088 | } | |
1089 | ||
1090 | set_buffer_jbddirty(bh); | |
1091 | ||
1092 | /* | |
1093 | * Metadata already on the current transaction list doesn't | |
1094 | * need to be filed. Metadata on another transaction's list must | |
1095 | * be committing, and will be refiled once the commit completes: | |
1096 | * leave it alone for now. | |
1097 | */ | |
1098 | if (jh->b_transaction != transaction) { | |
1099 | JBUFFER_TRACE(jh, "already on other transaction"); | |
1100 | J_ASSERT_JH(jh, jh->b_transaction == | |
1101 | journal->j_committing_transaction); | |
1102 | J_ASSERT_JH(jh, jh->b_next_transaction == transaction); | |
1103 | /* And this case is illegal: we can't reuse another | |
1104 | * transaction's data buffer, ever. */ | |
1105 | goto out_unlock_bh; | |
1106 | } | |
1107 | ||
1108 | /* That test should have eliminated the following case: */ | |
4019191b | 1109 | J_ASSERT_JH(jh, jh->b_frozen_data == NULL); |
470decc6 DK |
1110 | |
1111 | JBUFFER_TRACE(jh, "file as BJ_Metadata"); | |
1112 | spin_lock(&journal->j_list_lock); | |
f7f4bccb | 1113 | __jbd2_journal_file_buffer(jh, handle->h_transaction, BJ_Metadata); |
470decc6 DK |
1114 | spin_unlock(&journal->j_list_lock); |
1115 | out_unlock_bh: | |
1116 | jbd_unlock_bh_state(bh); | |
1117 | out: | |
1118 | JBUFFER_TRACE(jh, "exit"); | |
1119 | return 0; | |
1120 | } | |
1121 | ||
1122 | /* | |
f7f4bccb | 1123 | * jbd2_journal_release_buffer: undo a get_write_access without any buffer |
470decc6 DK |
1124 | * updates, if the update decided in the end that it didn't need access. |
1125 | * | |
1126 | */ | |
1127 | void | |
f7f4bccb | 1128 | jbd2_journal_release_buffer(handle_t *handle, struct buffer_head *bh) |
470decc6 DK |
1129 | { |
1130 | BUFFER_TRACE(bh, "entry"); | |
1131 | } | |
1132 | ||
1133 | /** | |
f7f4bccb | 1134 | * void jbd2_journal_forget() - bforget() for potentially-journaled buffers. |
470decc6 DK |
1135 | * @handle: transaction handle |
1136 | * @bh: bh to 'forget' | |
1137 | * | |
1138 | * We can only do the bforget if there are no commits pending against the | |
1139 | * buffer. If the buffer is dirty in the current running transaction we | |
1140 | * can safely unlink it. | |
1141 | * | |
1142 | * bh may not be a journalled buffer at all - it may be a non-JBD | |
1143 | * buffer which came off the hashtable. Check for this. | |
1144 | * | |
1145 | * Decrements bh->b_count by one. | |
1146 | * | |
1147 | * Allow this call even if the handle has aborted --- it may be part of | |
1148 | * the caller's cleanup after an abort. | |
1149 | */ | |
f7f4bccb | 1150 | int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh) |
470decc6 DK |
1151 | { |
1152 | transaction_t *transaction = handle->h_transaction; | |
1153 | journal_t *journal = transaction->t_journal; | |
1154 | struct journal_head *jh; | |
1155 | int drop_reserve = 0; | |
1156 | int err = 0; | |
1dfc3220 | 1157 | int was_modified = 0; |
470decc6 DK |
1158 | |
1159 | BUFFER_TRACE(bh, "entry"); | |
1160 | ||
1161 | jbd_lock_bh_state(bh); | |
1162 | spin_lock(&journal->j_list_lock); | |
1163 | ||
1164 | if (!buffer_jbd(bh)) | |
1165 | goto not_jbd; | |
1166 | jh = bh2jh(bh); | |
1167 | ||
1168 | /* Critical error: attempting to delete a bitmap buffer, maybe? | |
1169 | * Don't do any jbd operations, and return an error. */ | |
1170 | if (!J_EXPECT_JH(jh, !jh->b_committed_data, | |
1171 | "inconsistent data on disk")) { | |
1172 | err = -EIO; | |
1173 | goto not_jbd; | |
1174 | } | |
1175 | ||
1dfc3220 JB |
1176 | /* keep track of wether or not this transaction modified us */ |
1177 | was_modified = jh->b_modified; | |
1178 | ||
470decc6 DK |
1179 | /* |
1180 | * The buffer's going from the transaction, we must drop | |
1181 | * all references -bzzz | |
1182 | */ | |
1183 | jh->b_modified = 0; | |
1184 | ||
1185 | if (jh->b_transaction == handle->h_transaction) { | |
1186 | J_ASSERT_JH(jh, !jh->b_frozen_data); | |
1187 | ||
1188 | /* If we are forgetting a buffer which is already part | |
1189 | * of this transaction, then we can just drop it from | |
1190 | * the transaction immediately. */ | |
1191 | clear_buffer_dirty(bh); | |
1192 | clear_buffer_jbddirty(bh); | |
1193 | ||
1194 | JBUFFER_TRACE(jh, "belongs to current transaction: unfile"); | |
1195 | ||
1dfc3220 JB |
1196 | /* |
1197 | * we only want to drop a reference if this transaction | |
1198 | * modified the buffer | |
1199 | */ | |
1200 | if (was_modified) | |
1201 | drop_reserve = 1; | |
470decc6 DK |
1202 | |
1203 | /* | |
1204 | * We are no longer going to journal this buffer. | |
1205 | * However, the commit of this transaction is still | |
1206 | * important to the buffer: the delete that we are now | |
1207 | * processing might obsolete an old log entry, so by | |
1208 | * committing, we can satisfy the buffer's checkpoint. | |
1209 | * | |
1210 | * So, if we have a checkpoint on the buffer, we should | |
1211 | * now refile the buffer on our BJ_Forget list so that | |
1212 | * we know to remove the checkpoint after we commit. | |
1213 | */ | |
1214 | ||
1215 | if (jh->b_cp_transaction) { | |
f7f4bccb MC |
1216 | __jbd2_journal_temp_unlink_buffer(jh); |
1217 | __jbd2_journal_file_buffer(jh, transaction, BJ_Forget); | |
470decc6 | 1218 | } else { |
f7f4bccb MC |
1219 | __jbd2_journal_unfile_buffer(jh); |
1220 | jbd2_journal_remove_journal_head(bh); | |
470decc6 DK |
1221 | __brelse(bh); |
1222 | if (!buffer_jbd(bh)) { | |
1223 | spin_unlock(&journal->j_list_lock); | |
1224 | jbd_unlock_bh_state(bh); | |
1225 | __bforget(bh); | |
1226 | goto drop; | |
1227 | } | |
1228 | } | |
1229 | } else if (jh->b_transaction) { | |
1230 | J_ASSERT_JH(jh, (jh->b_transaction == | |
1231 | journal->j_committing_transaction)); | |
1232 | /* However, if the buffer is still owned by a prior | |
1233 | * (committing) transaction, we can't drop it yet... */ | |
1234 | JBUFFER_TRACE(jh, "belongs to older transaction"); | |
1235 | /* ... but we CAN drop it from the new transaction if we | |
1236 | * have also modified it since the original commit. */ | |
1237 | ||
1238 | if (jh->b_next_transaction) { | |
1239 | J_ASSERT(jh->b_next_transaction == transaction); | |
1240 | jh->b_next_transaction = NULL; | |
1dfc3220 JB |
1241 | |
1242 | /* | |
1243 | * only drop a reference if this transaction modified | |
1244 | * the buffer | |
1245 | */ | |
1246 | if (was_modified) | |
1247 | drop_reserve = 1; | |
470decc6 DK |
1248 | } |
1249 | } | |
1250 | ||
1251 | not_jbd: | |
1252 | spin_unlock(&journal->j_list_lock); | |
1253 | jbd_unlock_bh_state(bh); | |
1254 | __brelse(bh); | |
1255 | drop: | |
1256 | if (drop_reserve) { | |
1257 | /* no need to reserve log space for this block -bzzz */ | |
1258 | handle->h_buffer_credits++; | |
1259 | } | |
1260 | return err; | |
1261 | } | |
1262 | ||
1263 | /** | |
f7f4bccb | 1264 | * int jbd2_journal_stop() - complete a transaction |
470decc6 DK |
1265 | * @handle: tranaction to complete. |
1266 | * | |
1267 | * All done for a particular handle. | |
1268 | * | |
1269 | * There is not much action needed here. We just return any remaining | |
1270 | * buffer credits to the transaction and remove the handle. The only | |
1271 | * complication is that we need to start a commit operation if the | |
1272 | * filesystem is marked for synchronous update. | |
1273 | * | |
f7f4bccb | 1274 | * jbd2_journal_stop itself will not usually return an error, but it may |
470decc6 | 1275 | * do so in unusual circumstances. In particular, expect it to |
f7f4bccb | 1276 | * return -EIO if a jbd2_journal_abort has been executed since the |
470decc6 DK |
1277 | * transaction began. |
1278 | */ | |
f7f4bccb | 1279 | int jbd2_journal_stop(handle_t *handle) |
470decc6 DK |
1280 | { |
1281 | transaction_t *transaction = handle->h_transaction; | |
1282 | journal_t *journal = transaction->t_journal; | |
a51dca9c TT |
1283 | int err, wait_for_commit = 0; |
1284 | tid_t tid; | |
470decc6 DK |
1285 | pid_t pid; |
1286 | ||
470decc6 DK |
1287 | J_ASSERT(journal_current_handle() == handle); |
1288 | ||
1289 | if (is_handle_aborted(handle)) | |
1290 | err = -EIO; | |
3e2a532b | 1291 | else { |
a51dca9c | 1292 | J_ASSERT(atomic_read(&transaction->t_updates) > 0); |
470decc6 | 1293 | err = 0; |
3e2a532b | 1294 | } |
470decc6 DK |
1295 | |
1296 | if (--handle->h_ref > 0) { | |
1297 | jbd_debug(4, "h_ref %d -> %d\n", handle->h_ref + 1, | |
1298 | handle->h_ref); | |
1299 | return err; | |
1300 | } | |
1301 | ||
1302 | jbd_debug(4, "Handle %p going down\n", handle); | |
1303 | ||
1304 | /* | |
1305 | * Implement synchronous transaction batching. If the handle | |
1306 | * was synchronous, don't force a commit immediately. Let's | |
e07f7183 JB |
1307 | * yield and let another thread piggyback onto this |
1308 | * transaction. Keep doing that while new threads continue to | |
1309 | * arrive. It doesn't cost much - we're about to run a commit | |
1310 | * and sleep on IO anyway. Speeds up many-threaded, many-dir | |
1311 | * operations by 30x or more... | |
1312 | * | |
1313 | * We try and optimize the sleep time against what the | |
1314 | * underlying disk can do, instead of having a static sleep | |
1315 | * time. This is useful for the case where our storage is so | |
1316 | * fast that it is more optimal to go ahead and force a flush | |
1317 | * and wait for the transaction to be committed than it is to | |
1318 | * wait for an arbitrary amount of time for new writers to | |
1319 | * join the transaction. We achieve this by measuring how | |
1320 | * long it takes to commit a transaction, and compare it with | |
1321 | * how long this transaction has been running, and if run time | |
1322 | * < commit time then we sleep for the delta and commit. This | |
1323 | * greatly helps super fast disks that would see slowdowns as | |
1324 | * more threads started doing fsyncs. | |
470decc6 | 1325 | * |
e07f7183 JB |
1326 | * But don't do this if this process was the most recent one |
1327 | * to perform a synchronous write. We do this to detect the | |
1328 | * case where a single process is doing a stream of sync | |
1329 | * writes. No point in waiting for joiners in that case. | |
470decc6 DK |
1330 | */ |
1331 | pid = current->pid; | |
1332 | if (handle->h_sync && journal->j_last_sync_writer != pid) { | |
e07f7183 JB |
1333 | u64 commit_time, trans_time; |
1334 | ||
470decc6 | 1335 | journal->j_last_sync_writer = pid; |
e07f7183 | 1336 | |
a931da6a | 1337 | read_lock(&journal->j_state_lock); |
e07f7183 | 1338 | commit_time = journal->j_average_commit_time; |
a931da6a | 1339 | read_unlock(&journal->j_state_lock); |
e07f7183 JB |
1340 | |
1341 | trans_time = ktime_to_ns(ktime_sub(ktime_get(), | |
1342 | transaction->t_start_time)); | |
1343 | ||
30773840 TT |
1344 | commit_time = max_t(u64, commit_time, |
1345 | 1000*journal->j_min_batch_time); | |
e07f7183 | 1346 | commit_time = min_t(u64, commit_time, |
30773840 | 1347 | 1000*journal->j_max_batch_time); |
e07f7183 JB |
1348 | |
1349 | if (trans_time < commit_time) { | |
1350 | ktime_t expires = ktime_add_ns(ktime_get(), | |
1351 | commit_time); | |
1352 | set_current_state(TASK_UNINTERRUPTIBLE); | |
1353 | schedule_hrtimeout(&expires, HRTIMER_MODE_ABS); | |
1354 | } | |
470decc6 DK |
1355 | } |
1356 | ||
7058548c TT |
1357 | if (handle->h_sync) |
1358 | transaction->t_synchronous_commit = 1; | |
470decc6 | 1359 | current->journal_info = NULL; |
a51dca9c TT |
1360 | atomic_sub(handle->h_buffer_credits, |
1361 | &transaction->t_outstanding_credits); | |
470decc6 DK |
1362 | |
1363 | /* | |
1364 | * If the handle is marked SYNC, we need to set another commit | |
1365 | * going! We also want to force a commit if the current | |
1366 | * transaction is occupying too much of the log, or if the | |
1367 | * transaction is too old now. | |
1368 | */ | |
1369 | if (handle->h_sync || | |
a51dca9c TT |
1370 | (atomic_read(&transaction->t_outstanding_credits) > |
1371 | journal->j_max_transaction_buffers) || | |
1372 | time_after_eq(jiffies, transaction->t_expires)) { | |
470decc6 DK |
1373 | /* Do this even for aborted journals: an abort still |
1374 | * completes the commit thread, it just doesn't write | |
1375 | * anything to disk. */ | |
470decc6 | 1376 | |
470decc6 DK |
1377 | jbd_debug(2, "transaction too old, requesting commit for " |
1378 | "handle %p\n", handle); | |
1379 | /* This is non-blocking */ | |
c35a56a0 | 1380 | jbd2_log_start_commit(journal, transaction->t_tid); |
470decc6 DK |
1381 | |
1382 | /* | |
f7f4bccb | 1383 | * Special case: JBD2_SYNC synchronous updates require us |
470decc6 DK |
1384 | * to wait for the commit to complete. |
1385 | */ | |
1386 | if (handle->h_sync && !(current->flags & PF_MEMALLOC)) | |
a51dca9c | 1387 | wait_for_commit = 1; |
470decc6 DK |
1388 | } |
1389 | ||
a51dca9c TT |
1390 | /* |
1391 | * Once we drop t_updates, if it goes to zero the transaction | |
1392 | * could start commiting on us and eventually disappear. So | |
1393 | * once we do this, we must not dereference transaction | |
1394 | * pointer again. | |
1395 | */ | |
1396 | tid = transaction->t_tid; | |
1397 | if (atomic_dec_and_test(&transaction->t_updates)) { | |
1398 | wake_up(&journal->j_wait_updates); | |
1399 | if (journal->j_barrier_count) | |
1400 | wake_up(&journal->j_wait_transaction_locked); | |
1401 | } | |
1402 | ||
1403 | if (wait_for_commit) | |
1404 | err = jbd2_log_wait_commit(journal, tid); | |
1405 | ||
3295f0ef | 1406 | lock_map_release(&handle->h_lockdep_map); |
7b751066 | 1407 | |
af1e76d6 | 1408 | jbd2_free_handle(handle); |
470decc6 DK |
1409 | return err; |
1410 | } | |
1411 | ||
5648ba5b RD |
1412 | /** |
1413 | * int jbd2_journal_force_commit() - force any uncommitted transactions | |
470decc6 DK |
1414 | * @journal: journal to force |
1415 | * | |
1416 | * For synchronous operations: force any uncommitted transactions | |
1417 | * to disk. May seem kludgy, but it reuses all the handle batching | |
1418 | * code in a very simple manner. | |
1419 | */ | |
f7f4bccb | 1420 | int jbd2_journal_force_commit(journal_t *journal) |
470decc6 DK |
1421 | { |
1422 | handle_t *handle; | |
1423 | int ret; | |
1424 | ||
f7f4bccb | 1425 | handle = jbd2_journal_start(journal, 1); |
470decc6 DK |
1426 | if (IS_ERR(handle)) { |
1427 | ret = PTR_ERR(handle); | |
1428 | } else { | |
1429 | handle->h_sync = 1; | |
f7f4bccb | 1430 | ret = jbd2_journal_stop(handle); |
470decc6 DK |
1431 | } |
1432 | return ret; | |
1433 | } | |
1434 | ||
1435 | /* | |
1436 | * | |
1437 | * List management code snippets: various functions for manipulating the | |
1438 | * transaction buffer lists. | |
1439 | * | |
1440 | */ | |
1441 | ||
1442 | /* | |
1443 | * Append a buffer to a transaction list, given the transaction's list head | |
1444 | * pointer. | |
1445 | * | |
1446 | * j_list_lock is held. | |
1447 | * | |
1448 | * jbd_lock_bh_state(jh2bh(jh)) is held. | |
1449 | */ | |
1450 | ||
1451 | static inline void | |
1452 | __blist_add_buffer(struct journal_head **list, struct journal_head *jh) | |
1453 | { | |
1454 | if (!*list) { | |
1455 | jh->b_tnext = jh->b_tprev = jh; | |
1456 | *list = jh; | |
1457 | } else { | |
1458 | /* Insert at the tail of the list to preserve order */ | |
1459 | struct journal_head *first = *list, *last = first->b_tprev; | |
1460 | jh->b_tprev = last; | |
1461 | jh->b_tnext = first; | |
1462 | last->b_tnext = first->b_tprev = jh; | |
1463 | } | |
1464 | } | |
1465 | ||
1466 | /* | |
1467 | * Remove a buffer from a transaction list, given the transaction's list | |
1468 | * head pointer. | |
1469 | * | |
1470 | * Called with j_list_lock held, and the journal may not be locked. | |
1471 | * | |
1472 | * jbd_lock_bh_state(jh2bh(jh)) is held. | |
1473 | */ | |
1474 | ||
1475 | static inline void | |
1476 | __blist_del_buffer(struct journal_head **list, struct journal_head *jh) | |
1477 | { | |
1478 | if (*list == jh) { | |
1479 | *list = jh->b_tnext; | |
1480 | if (*list == jh) | |
1481 | *list = NULL; | |
1482 | } | |
1483 | jh->b_tprev->b_tnext = jh->b_tnext; | |
1484 | jh->b_tnext->b_tprev = jh->b_tprev; | |
1485 | } | |
1486 | ||
1487 | /* | |
1488 | * Remove a buffer from the appropriate transaction list. | |
1489 | * | |
1490 | * Note that this function can *change* the value of | |
87c89c23 JK |
1491 | * bh->b_transaction->t_buffers, t_forget, t_iobuf_list, t_shadow_list, |
1492 | * t_log_list or t_reserved_list. If the caller is holding onto a copy of one | |
1493 | * of these pointers, it could go bad. Generally the caller needs to re-read | |
1494 | * the pointer from the transaction_t. | |
470decc6 DK |
1495 | * |
1496 | * Called under j_list_lock. The journal may not be locked. | |
1497 | */ | |
f7f4bccb | 1498 | void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh) |
470decc6 DK |
1499 | { |
1500 | struct journal_head **list = NULL; | |
1501 | transaction_t *transaction; | |
1502 | struct buffer_head *bh = jh2bh(jh); | |
1503 | ||
1504 | J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh)); | |
1505 | transaction = jh->b_transaction; | |
1506 | if (transaction) | |
1507 | assert_spin_locked(&transaction->t_journal->j_list_lock); | |
1508 | ||
1509 | J_ASSERT_JH(jh, jh->b_jlist < BJ_Types); | |
1510 | if (jh->b_jlist != BJ_None) | |
4019191b | 1511 | J_ASSERT_JH(jh, transaction != NULL); |
470decc6 DK |
1512 | |
1513 | switch (jh->b_jlist) { | |
1514 | case BJ_None: | |
1515 | return; | |
470decc6 DK |
1516 | case BJ_Metadata: |
1517 | transaction->t_nr_buffers--; | |
1518 | J_ASSERT_JH(jh, transaction->t_nr_buffers >= 0); | |
1519 | list = &transaction->t_buffers; | |
1520 | break; | |
1521 | case BJ_Forget: | |
1522 | list = &transaction->t_forget; | |
1523 | break; | |
1524 | case BJ_IO: | |
1525 | list = &transaction->t_iobuf_list; | |
1526 | break; | |
1527 | case BJ_Shadow: | |
1528 | list = &transaction->t_shadow_list; | |
1529 | break; | |
1530 | case BJ_LogCtl: | |
1531 | list = &transaction->t_log_list; | |
1532 | break; | |
1533 | case BJ_Reserved: | |
1534 | list = &transaction->t_reserved_list; | |
1535 | break; | |
470decc6 DK |
1536 | } |
1537 | ||
1538 | __blist_del_buffer(list, jh); | |
1539 | jh->b_jlist = BJ_None; | |
1540 | if (test_clear_buffer_jbddirty(bh)) | |
1541 | mark_buffer_dirty(bh); /* Expose it to the VM */ | |
1542 | } | |
1543 | ||
f7f4bccb | 1544 | void __jbd2_journal_unfile_buffer(struct journal_head *jh) |
470decc6 | 1545 | { |
f7f4bccb | 1546 | __jbd2_journal_temp_unlink_buffer(jh); |
470decc6 DK |
1547 | jh->b_transaction = NULL; |
1548 | } | |
1549 | ||
f7f4bccb | 1550 | void jbd2_journal_unfile_buffer(journal_t *journal, struct journal_head *jh) |
470decc6 DK |
1551 | { |
1552 | jbd_lock_bh_state(jh2bh(jh)); | |
1553 | spin_lock(&journal->j_list_lock); | |
f7f4bccb | 1554 | __jbd2_journal_unfile_buffer(jh); |
470decc6 DK |
1555 | spin_unlock(&journal->j_list_lock); |
1556 | jbd_unlock_bh_state(jh2bh(jh)); | |
1557 | } | |
1558 | ||
1559 | /* | |
f7f4bccb | 1560 | * Called from jbd2_journal_try_to_free_buffers(). |
470decc6 DK |
1561 | * |
1562 | * Called under jbd_lock_bh_state(bh) | |
1563 | */ | |
1564 | static void | |
1565 | __journal_try_to_free_buffer(journal_t *journal, struct buffer_head *bh) | |
1566 | { | |
1567 | struct journal_head *jh; | |
1568 | ||
1569 | jh = bh2jh(bh); | |
1570 | ||
1571 | if (buffer_locked(bh) || buffer_dirty(bh)) | |
1572 | goto out; | |
1573 | ||
4019191b | 1574 | if (jh->b_next_transaction != NULL) |
470decc6 DK |
1575 | goto out; |
1576 | ||
1577 | spin_lock(&journal->j_list_lock); | |
87c89c23 | 1578 | if (jh->b_cp_transaction != NULL && jh->b_transaction == NULL) { |
470decc6 DK |
1579 | /* written-back checkpointed metadata buffer */ |
1580 | if (jh->b_jlist == BJ_None) { | |
1581 | JBUFFER_TRACE(jh, "remove from checkpoint list"); | |
f7f4bccb MC |
1582 | __jbd2_journal_remove_checkpoint(jh); |
1583 | jbd2_journal_remove_journal_head(bh); | |
470decc6 DK |
1584 | __brelse(bh); |
1585 | } | |
1586 | } | |
1587 | spin_unlock(&journal->j_list_lock); | |
1588 | out: | |
1589 | return; | |
1590 | } | |
1591 | ||
470decc6 | 1592 | /** |
f7f4bccb | 1593 | * int jbd2_journal_try_to_free_buffers() - try to free page buffers. |
470decc6 DK |
1594 | * @journal: journal for operation |
1595 | * @page: to try and free | |
530576bb MC |
1596 | * @gfp_mask: we use the mask to detect how hard should we try to release |
1597 | * buffers. If __GFP_WAIT and __GFP_FS is set, we wait for commit code to | |
1598 | * release the buffers. | |
470decc6 DK |
1599 | * |
1600 | * | |
1601 | * For all the buffers on this page, | |
1602 | * if they are fully written out ordered data, move them onto BUF_CLEAN | |
1603 | * so try_to_free_buffers() can reap them. | |
1604 | * | |
1605 | * This function returns non-zero if we wish try_to_free_buffers() | |
1606 | * to be called. We do this if the page is releasable by try_to_free_buffers(). | |
1607 | * We also do it if the page has locked or dirty buffers and the caller wants | |
1608 | * us to perform sync or async writeout. | |
1609 | * | |
1610 | * This complicates JBD locking somewhat. We aren't protected by the | |
1611 | * BKL here. We wish to remove the buffer from its committing or | |
f7f4bccb | 1612 | * running transaction's ->t_datalist via __jbd2_journal_unfile_buffer. |
470decc6 DK |
1613 | * |
1614 | * This may *change* the value of transaction_t->t_datalist, so anyone | |
1615 | * who looks at t_datalist needs to lock against this function. | |
1616 | * | |
f7f4bccb MC |
1617 | * Even worse, someone may be doing a jbd2_journal_dirty_data on this |
1618 | * buffer. So we need to lock against that. jbd2_journal_dirty_data() | |
470decc6 DK |
1619 | * will come out of the lock with the buffer dirty, which makes it |
1620 | * ineligible for release here. | |
1621 | * | |
1622 | * Who else is affected by this? hmm... Really the only contender | |
1623 | * is do_get_write_access() - it could be looking at the buffer while | |
1624 | * journal_try_to_free_buffer() is changing its state. But that | |
1625 | * cannot happen because we never reallocate freed data as metadata | |
1626 | * while the data is part of a transaction. Yes? | |
530576bb MC |
1627 | * |
1628 | * Return 0 on failure, 1 on success | |
470decc6 | 1629 | */ |
f7f4bccb | 1630 | int jbd2_journal_try_to_free_buffers(journal_t *journal, |
530576bb | 1631 | struct page *page, gfp_t gfp_mask) |
470decc6 DK |
1632 | { |
1633 | struct buffer_head *head; | |
1634 | struct buffer_head *bh; | |
1635 | int ret = 0; | |
1636 | ||
1637 | J_ASSERT(PageLocked(page)); | |
1638 | ||
1639 | head = page_buffers(page); | |
1640 | bh = head; | |
1641 | do { | |
1642 | struct journal_head *jh; | |
1643 | ||
1644 | /* | |
1645 | * We take our own ref against the journal_head here to avoid | |
1646 | * having to add tons of locking around each instance of | |
530576bb MC |
1647 | * jbd2_journal_remove_journal_head() and |
1648 | * jbd2_journal_put_journal_head(). | |
470decc6 | 1649 | */ |
f7f4bccb | 1650 | jh = jbd2_journal_grab_journal_head(bh); |
470decc6 DK |
1651 | if (!jh) |
1652 | continue; | |
1653 | ||
1654 | jbd_lock_bh_state(bh); | |
1655 | __journal_try_to_free_buffer(journal, bh); | |
f7f4bccb | 1656 | jbd2_journal_put_journal_head(jh); |
470decc6 DK |
1657 | jbd_unlock_bh_state(bh); |
1658 | if (buffer_jbd(bh)) | |
1659 | goto busy; | |
1660 | } while ((bh = bh->b_this_page) != head); | |
530576bb | 1661 | |
470decc6 | 1662 | ret = try_to_free_buffers(page); |
530576bb | 1663 | |
470decc6 DK |
1664 | busy: |
1665 | return ret; | |
1666 | } | |
1667 | ||
1668 | /* | |
1669 | * This buffer is no longer needed. If it is on an older transaction's | |
1670 | * checkpoint list we need to record it on this transaction's forget list | |
1671 | * to pin this buffer (and hence its checkpointing transaction) down until | |
1672 | * this transaction commits. If the buffer isn't on a checkpoint list, we | |
1673 | * release it. | |
1674 | * Returns non-zero if JBD no longer has an interest in the buffer. | |
1675 | * | |
1676 | * Called under j_list_lock. | |
1677 | * | |
1678 | * Called under jbd_lock_bh_state(bh). | |
1679 | */ | |
1680 | static int __dispose_buffer(struct journal_head *jh, transaction_t *transaction) | |
1681 | { | |
1682 | int may_free = 1; | |
1683 | struct buffer_head *bh = jh2bh(jh); | |
1684 | ||
f7f4bccb | 1685 | __jbd2_journal_unfile_buffer(jh); |
470decc6 DK |
1686 | |
1687 | if (jh->b_cp_transaction) { | |
1688 | JBUFFER_TRACE(jh, "on running+cp transaction"); | |
f91d1d04 JK |
1689 | /* |
1690 | * We don't want to write the buffer anymore, clear the | |
1691 | * bit so that we don't confuse checks in | |
1692 | * __journal_file_buffer | |
1693 | */ | |
1694 | clear_buffer_dirty(bh); | |
f7f4bccb | 1695 | __jbd2_journal_file_buffer(jh, transaction, BJ_Forget); |
470decc6 DK |
1696 | may_free = 0; |
1697 | } else { | |
1698 | JBUFFER_TRACE(jh, "on running transaction"); | |
f7f4bccb | 1699 | jbd2_journal_remove_journal_head(bh); |
470decc6 DK |
1700 | __brelse(bh); |
1701 | } | |
1702 | return may_free; | |
1703 | } | |
1704 | ||
1705 | /* | |
f7f4bccb | 1706 | * jbd2_journal_invalidatepage |
470decc6 DK |
1707 | * |
1708 | * This code is tricky. It has a number of cases to deal with. | |
1709 | * | |
1710 | * There are two invariants which this code relies on: | |
1711 | * | |
1712 | * i_size must be updated on disk before we start calling invalidatepage on the | |
1713 | * data. | |
1714 | * | |
1715 | * This is done in ext3 by defining an ext3_setattr method which | |
1716 | * updates i_size before truncate gets going. By maintaining this | |
1717 | * invariant, we can be sure that it is safe to throw away any buffers | |
1718 | * attached to the current transaction: once the transaction commits, | |
1719 | * we know that the data will not be needed. | |
1720 | * | |
1721 | * Note however that we can *not* throw away data belonging to the | |
1722 | * previous, committing transaction! | |
1723 | * | |
1724 | * Any disk blocks which *are* part of the previous, committing | |
1725 | * transaction (and which therefore cannot be discarded immediately) are | |
1726 | * not going to be reused in the new running transaction | |
1727 | * | |
1728 | * The bitmap committed_data images guarantee this: any block which is | |
1729 | * allocated in one transaction and removed in the next will be marked | |
1730 | * as in-use in the committed_data bitmap, so cannot be reused until | |
1731 | * the next transaction to delete the block commits. This means that | |
1732 | * leaving committing buffers dirty is quite safe: the disk blocks | |
1733 | * cannot be reallocated to a different file and so buffer aliasing is | |
1734 | * not possible. | |
1735 | * | |
1736 | * | |
1737 | * The above applies mainly to ordered data mode. In writeback mode we | |
1738 | * don't make guarantees about the order in which data hits disk --- in | |
1739 | * particular we don't guarantee that new dirty data is flushed before | |
1740 | * transaction commit --- so it is always safe just to discard data | |
1741 | * immediately in that mode. --sct | |
1742 | */ | |
1743 | ||
1744 | /* | |
1745 | * The journal_unmap_buffer helper function returns zero if the buffer | |
1746 | * concerned remains pinned as an anonymous buffer belonging to an older | |
1747 | * transaction. | |
1748 | * | |
1749 | * We're outside-transaction here. Either or both of j_running_transaction | |
1750 | * and j_committing_transaction may be NULL. | |
1751 | */ | |
1752 | static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh) | |
1753 | { | |
1754 | transaction_t *transaction; | |
1755 | struct journal_head *jh; | |
1756 | int may_free = 1; | |
1757 | int ret; | |
1758 | ||
1759 | BUFFER_TRACE(bh, "entry"); | |
1760 | ||
1761 | /* | |
1762 | * It is safe to proceed here without the j_list_lock because the | |
1763 | * buffers cannot be stolen by try_to_free_buffers as long as we are | |
1764 | * holding the page lock. --sct | |
1765 | */ | |
1766 | ||
1767 | if (!buffer_jbd(bh)) | |
1768 | goto zap_buffer_unlocked; | |
1769 | ||
87c89c23 | 1770 | /* OK, we have data buffer in journaled mode */ |
a931da6a | 1771 | write_lock(&journal->j_state_lock); |
470decc6 DK |
1772 | jbd_lock_bh_state(bh); |
1773 | spin_lock(&journal->j_list_lock); | |
1774 | ||
f7f4bccb | 1775 | jh = jbd2_journal_grab_journal_head(bh); |
470decc6 DK |
1776 | if (!jh) |
1777 | goto zap_buffer_no_jh; | |
1778 | ||
ba869023 | 1779 | /* |
1780 | * We cannot remove the buffer from checkpoint lists until the | |
1781 | * transaction adding inode to orphan list (let's call it T) | |
1782 | * is committed. Otherwise if the transaction changing the | |
1783 | * buffer would be cleaned from the journal before T is | |
1784 | * committed, a crash will cause that the correct contents of | |
1785 | * the buffer will be lost. On the other hand we have to | |
1786 | * clear the buffer dirty bit at latest at the moment when the | |
1787 | * transaction marking the buffer as freed in the filesystem | |
1788 | * structures is committed because from that moment on the | |
1789 | * buffer can be reallocated and used by a different page. | |
1790 | * Since the block hasn't been freed yet but the inode has | |
1791 | * already been added to orphan list, it is safe for us to add | |
1792 | * the buffer to BJ_Forget list of the newest transaction. | |
1793 | */ | |
470decc6 DK |
1794 | transaction = jh->b_transaction; |
1795 | if (transaction == NULL) { | |
1796 | /* First case: not on any transaction. If it | |
1797 | * has no checkpoint link, then we can zap it: | |
1798 | * it's a writeback-mode buffer so we don't care | |
1799 | * if it hits disk safely. */ | |
1800 | if (!jh->b_cp_transaction) { | |
1801 | JBUFFER_TRACE(jh, "not on any transaction: zap"); | |
1802 | goto zap_buffer; | |
1803 | } | |
1804 | ||
1805 | if (!buffer_dirty(bh)) { | |
1806 | /* bdflush has written it. We can drop it now */ | |
1807 | goto zap_buffer; | |
1808 | } | |
1809 | ||
1810 | /* OK, it must be in the journal but still not | |
1811 | * written fully to disk: it's metadata or | |
1812 | * journaled data... */ | |
1813 | ||
1814 | if (journal->j_running_transaction) { | |
1815 | /* ... and once the current transaction has | |
1816 | * committed, the buffer won't be needed any | |
1817 | * longer. */ | |
1818 | JBUFFER_TRACE(jh, "checkpointed: add to BJ_Forget"); | |
1819 | ret = __dispose_buffer(jh, | |
1820 | journal->j_running_transaction); | |
f7f4bccb | 1821 | jbd2_journal_put_journal_head(jh); |
470decc6 DK |
1822 | spin_unlock(&journal->j_list_lock); |
1823 | jbd_unlock_bh_state(bh); | |
a931da6a | 1824 | write_unlock(&journal->j_state_lock); |
470decc6 DK |
1825 | return ret; |
1826 | } else { | |
1827 | /* There is no currently-running transaction. So the | |
1828 | * orphan record which we wrote for this file must have | |
1829 | * passed into commit. We must attach this buffer to | |
1830 | * the committing transaction, if it exists. */ | |
1831 | if (journal->j_committing_transaction) { | |
1832 | JBUFFER_TRACE(jh, "give to committing trans"); | |
1833 | ret = __dispose_buffer(jh, | |
1834 | journal->j_committing_transaction); | |
f7f4bccb | 1835 | jbd2_journal_put_journal_head(jh); |
470decc6 DK |
1836 | spin_unlock(&journal->j_list_lock); |
1837 | jbd_unlock_bh_state(bh); | |
a931da6a | 1838 | write_unlock(&journal->j_state_lock); |
470decc6 DK |
1839 | return ret; |
1840 | } else { | |
1841 | /* The orphan record's transaction has | |
1842 | * committed. We can cleanse this buffer */ | |
1843 | clear_buffer_jbddirty(bh); | |
1844 | goto zap_buffer; | |
1845 | } | |
1846 | } | |
1847 | } else if (transaction == journal->j_committing_transaction) { | |
9b57988d | 1848 | JBUFFER_TRACE(jh, "on committing transaction"); |
470decc6 | 1849 | /* |
ba869023 | 1850 | * The buffer is committing, we simply cannot touch |
1851 | * it. So we just set j_next_transaction to the | |
1852 | * running transaction (if there is one) and mark | |
1853 | * buffer as freed so that commit code knows it should | |
1854 | * clear dirty bits when it is done with the buffer. | |
1855 | */ | |
470decc6 | 1856 | set_buffer_freed(bh); |
ba869023 | 1857 | if (journal->j_running_transaction && buffer_jbddirty(bh)) |
1858 | jh->b_next_transaction = journal->j_running_transaction; | |
f7f4bccb | 1859 | jbd2_journal_put_journal_head(jh); |
470decc6 DK |
1860 | spin_unlock(&journal->j_list_lock); |
1861 | jbd_unlock_bh_state(bh); | |
a931da6a | 1862 | write_unlock(&journal->j_state_lock); |
470decc6 DK |
1863 | return 0; |
1864 | } else { | |
1865 | /* Good, the buffer belongs to the running transaction. | |
1866 | * We are writing our own transaction's data, not any | |
1867 | * previous one's, so it is safe to throw it away | |
1868 | * (remember that we expect the filesystem to have set | |
1869 | * i_size already for this truncate so recovery will not | |
1870 | * expose the disk blocks we are discarding here.) */ | |
1871 | J_ASSERT_JH(jh, transaction == journal->j_running_transaction); | |
9b57988d | 1872 | JBUFFER_TRACE(jh, "on running transaction"); |
470decc6 DK |
1873 | may_free = __dispose_buffer(jh, transaction); |
1874 | } | |
1875 | ||
1876 | zap_buffer: | |
f7f4bccb | 1877 | jbd2_journal_put_journal_head(jh); |
470decc6 DK |
1878 | zap_buffer_no_jh: |
1879 | spin_unlock(&journal->j_list_lock); | |
1880 | jbd_unlock_bh_state(bh); | |
a931da6a | 1881 | write_unlock(&journal->j_state_lock); |
470decc6 DK |
1882 | zap_buffer_unlocked: |
1883 | clear_buffer_dirty(bh); | |
1884 | J_ASSERT_BH(bh, !buffer_jbddirty(bh)); | |
1885 | clear_buffer_mapped(bh); | |
1886 | clear_buffer_req(bh); | |
1887 | clear_buffer_new(bh); | |
1888 | bh->b_bdev = NULL; | |
1889 | return may_free; | |
1890 | } | |
1891 | ||
1892 | /** | |
f7f4bccb | 1893 | * void jbd2_journal_invalidatepage() |
470decc6 DK |
1894 | * @journal: journal to use for flush... |
1895 | * @page: page to flush | |
1896 | * @offset: length of page to invalidate. | |
1897 | * | |
1898 | * Reap page buffers containing data after offset in page. | |
1899 | * | |
1900 | */ | |
f7f4bccb | 1901 | void jbd2_journal_invalidatepage(journal_t *journal, |
470decc6 DK |
1902 | struct page *page, |
1903 | unsigned long offset) | |
1904 | { | |
1905 | struct buffer_head *head, *bh, *next; | |
1906 | unsigned int curr_off = 0; | |
1907 | int may_free = 1; | |
1908 | ||
1909 | if (!PageLocked(page)) | |
1910 | BUG(); | |
1911 | if (!page_has_buffers(page)) | |
1912 | return; | |
1913 | ||
1914 | /* We will potentially be playing with lists other than just the | |
1915 | * data lists (especially for journaled data mode), so be | |
1916 | * cautious in our locking. */ | |
1917 | ||
1918 | head = bh = page_buffers(page); | |
1919 | do { | |
1920 | unsigned int next_off = curr_off + bh->b_size; | |
1921 | next = bh->b_this_page; | |
1922 | ||
1923 | if (offset <= curr_off) { | |
1924 | /* This block is wholly outside the truncation point */ | |
1925 | lock_buffer(bh); | |
1926 | may_free &= journal_unmap_buffer(journal, bh); | |
1927 | unlock_buffer(bh); | |
1928 | } | |
1929 | curr_off = next_off; | |
1930 | bh = next; | |
1931 | ||
1932 | } while (bh != head); | |
1933 | ||
1934 | if (!offset) { | |
1935 | if (may_free && try_to_free_buffers(page)) | |
1936 | J_ASSERT(!page_has_buffers(page)); | |
1937 | } | |
1938 | } | |
1939 | ||
1940 | /* | |
1941 | * File a buffer on the given transaction list. | |
1942 | */ | |
f7f4bccb | 1943 | void __jbd2_journal_file_buffer(struct journal_head *jh, |
470decc6 DK |
1944 | transaction_t *transaction, int jlist) |
1945 | { | |
1946 | struct journal_head **list = NULL; | |
1947 | int was_dirty = 0; | |
1948 | struct buffer_head *bh = jh2bh(jh); | |
1949 | ||
1950 | J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh)); | |
1951 | assert_spin_locked(&transaction->t_journal->j_list_lock); | |
1952 | ||
1953 | J_ASSERT_JH(jh, jh->b_jlist < BJ_Types); | |
1954 | J_ASSERT_JH(jh, jh->b_transaction == transaction || | |
4019191b | 1955 | jh->b_transaction == NULL); |
470decc6 DK |
1956 | |
1957 | if (jh->b_transaction && jh->b_jlist == jlist) | |
1958 | return; | |
1959 | ||
470decc6 DK |
1960 | if (jlist == BJ_Metadata || jlist == BJ_Reserved || |
1961 | jlist == BJ_Shadow || jlist == BJ_Forget) { | |
f91d1d04 JK |
1962 | /* |
1963 | * For metadata buffers, we track dirty bit in buffer_jbddirty | |
1964 | * instead of buffer_dirty. We should not see a dirty bit set | |
1965 | * here because we clear it in do_get_write_access but e.g. | |
1966 | * tune2fs can modify the sb and set the dirty bit at any time | |
1967 | * so we try to gracefully handle that. | |
1968 | */ | |
1969 | if (buffer_dirty(bh)) | |
1970 | warn_dirty_buffer(bh); | |
470decc6 DK |
1971 | if (test_clear_buffer_dirty(bh) || |
1972 | test_clear_buffer_jbddirty(bh)) | |
1973 | was_dirty = 1; | |
1974 | } | |
1975 | ||
1976 | if (jh->b_transaction) | |
f7f4bccb | 1977 | __jbd2_journal_temp_unlink_buffer(jh); |
470decc6 DK |
1978 | jh->b_transaction = transaction; |
1979 | ||
1980 | switch (jlist) { | |
1981 | case BJ_None: | |
1982 | J_ASSERT_JH(jh, !jh->b_committed_data); | |
1983 | J_ASSERT_JH(jh, !jh->b_frozen_data); | |
1984 | return; | |
470decc6 DK |
1985 | case BJ_Metadata: |
1986 | transaction->t_nr_buffers++; | |
1987 | list = &transaction->t_buffers; | |
1988 | break; | |
1989 | case BJ_Forget: | |
1990 | list = &transaction->t_forget; | |
1991 | break; | |
1992 | case BJ_IO: | |
1993 | list = &transaction->t_iobuf_list; | |
1994 | break; | |
1995 | case BJ_Shadow: | |
1996 | list = &transaction->t_shadow_list; | |
1997 | break; | |
1998 | case BJ_LogCtl: | |
1999 | list = &transaction->t_log_list; | |
2000 | break; | |
2001 | case BJ_Reserved: | |
2002 | list = &transaction->t_reserved_list; | |
2003 | break; | |
470decc6 DK |
2004 | } |
2005 | ||
2006 | __blist_add_buffer(list, jh); | |
2007 | jh->b_jlist = jlist; | |
2008 | ||
2009 | if (was_dirty) | |
2010 | set_buffer_jbddirty(bh); | |
2011 | } | |
2012 | ||
f7f4bccb | 2013 | void jbd2_journal_file_buffer(struct journal_head *jh, |
470decc6 DK |
2014 | transaction_t *transaction, int jlist) |
2015 | { | |
2016 | jbd_lock_bh_state(jh2bh(jh)); | |
2017 | spin_lock(&transaction->t_journal->j_list_lock); | |
f7f4bccb | 2018 | __jbd2_journal_file_buffer(jh, transaction, jlist); |
470decc6 DK |
2019 | spin_unlock(&transaction->t_journal->j_list_lock); |
2020 | jbd_unlock_bh_state(jh2bh(jh)); | |
2021 | } | |
2022 | ||
2023 | /* | |
2024 | * Remove a buffer from its current buffer list in preparation for | |
2025 | * dropping it from its current transaction entirely. If the buffer has | |
2026 | * already started to be used by a subsequent transaction, refile the | |
2027 | * buffer on that transaction's metadata list. | |
2028 | * | |
2029 | * Called under journal->j_list_lock | |
2030 | * | |
2031 | * Called under jbd_lock_bh_state(jh2bh(jh)) | |
2032 | */ | |
f7f4bccb | 2033 | void __jbd2_journal_refile_buffer(struct journal_head *jh) |
470decc6 | 2034 | { |
ba869023 | 2035 | int was_dirty, jlist; |
470decc6 DK |
2036 | struct buffer_head *bh = jh2bh(jh); |
2037 | ||
2038 | J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh)); | |
2039 | if (jh->b_transaction) | |
2040 | assert_spin_locked(&jh->b_transaction->t_journal->j_list_lock); | |
2041 | ||
2042 | /* If the buffer is now unused, just drop it. */ | |
2043 | if (jh->b_next_transaction == NULL) { | |
f7f4bccb | 2044 | __jbd2_journal_unfile_buffer(jh); |
470decc6 DK |
2045 | return; |
2046 | } | |
2047 | ||
2048 | /* | |
2049 | * It has been modified by a later transaction: add it to the new | |
2050 | * transaction's metadata list. | |
2051 | */ | |
2052 | ||
2053 | was_dirty = test_clear_buffer_jbddirty(bh); | |
f7f4bccb | 2054 | __jbd2_journal_temp_unlink_buffer(jh); |
470decc6 DK |
2055 | jh->b_transaction = jh->b_next_transaction; |
2056 | jh->b_next_transaction = NULL; | |
ba869023 | 2057 | if (buffer_freed(bh)) |
2058 | jlist = BJ_Forget; | |
2059 | else if (jh->b_modified) | |
2060 | jlist = BJ_Metadata; | |
2061 | else | |
2062 | jlist = BJ_Reserved; | |
2063 | __jbd2_journal_file_buffer(jh, jh->b_transaction, jlist); | |
470decc6 DK |
2064 | J_ASSERT_JH(jh, jh->b_transaction->t_state == T_RUNNING); |
2065 | ||
2066 | if (was_dirty) | |
2067 | set_buffer_jbddirty(bh); | |
2068 | } | |
2069 | ||
2070 | /* | |
2071 | * For the unlocked version of this call, also make sure that any | |
2072 | * hanging journal_head is cleaned up if necessary. | |
2073 | * | |
f7f4bccb | 2074 | * __jbd2_journal_refile_buffer is usually called as part of a single locked |
470decc6 DK |
2075 | * operation on a buffer_head, in which the caller is probably going to |
2076 | * be hooking the journal_head onto other lists. In that case it is up | |
2077 | * to the caller to remove the journal_head if necessary. For the | |
f7f4bccb | 2078 | * unlocked jbd2_journal_refile_buffer call, the caller isn't going to be |
470decc6 DK |
2079 | * doing anything else to the buffer so we need to do the cleanup |
2080 | * ourselves to avoid a jh leak. | |
2081 | * | |
2082 | * *** The journal_head may be freed by this call! *** | |
2083 | */ | |
f7f4bccb | 2084 | void jbd2_journal_refile_buffer(journal_t *journal, struct journal_head *jh) |
470decc6 DK |
2085 | { |
2086 | struct buffer_head *bh = jh2bh(jh); | |
2087 | ||
2088 | jbd_lock_bh_state(bh); | |
2089 | spin_lock(&journal->j_list_lock); | |
2090 | ||
f7f4bccb | 2091 | __jbd2_journal_refile_buffer(jh); |
470decc6 | 2092 | jbd_unlock_bh_state(bh); |
f7f4bccb | 2093 | jbd2_journal_remove_journal_head(bh); |
470decc6 DK |
2094 | |
2095 | spin_unlock(&journal->j_list_lock); | |
2096 | __brelse(bh); | |
2097 | } | |
c851ed54 JK |
2098 | |
2099 | /* | |
2100 | * File inode in the inode list of the handle's transaction | |
2101 | */ | |
2102 | int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *jinode) | |
2103 | { | |
2104 | transaction_t *transaction = handle->h_transaction; | |
2105 | journal_t *journal = transaction->t_journal; | |
2106 | ||
2107 | if (is_handle_aborted(handle)) | |
2108 | return -EIO; | |
2109 | ||
2110 | jbd_debug(4, "Adding inode %lu, tid:%d\n", jinode->i_vfs_inode->i_ino, | |
2111 | transaction->t_tid); | |
2112 | ||
2113 | /* | |
2114 | * First check whether inode isn't already on the transaction's | |
2115 | * lists without taking the lock. Note that this check is safe | |
2116 | * without the lock as we cannot race with somebody removing inode | |
2117 | * from the transaction. The reason is that we remove inode from the | |
2118 | * transaction only in journal_release_jbd_inode() and when we commit | |
2119 | * the transaction. We are guarded from the first case by holding | |
2120 | * a reference to the inode. We are safe against the second case | |
2121 | * because if jinode->i_transaction == transaction, commit code | |
2122 | * cannot touch the transaction because we hold reference to it, | |
2123 | * and if jinode->i_next_transaction == transaction, commit code | |
2124 | * will only file the inode where we want it. | |
2125 | */ | |
2126 | if (jinode->i_transaction == transaction || | |
2127 | jinode->i_next_transaction == transaction) | |
2128 | return 0; | |
2129 | ||
2130 | spin_lock(&journal->j_list_lock); | |
2131 | ||
2132 | if (jinode->i_transaction == transaction || | |
2133 | jinode->i_next_transaction == transaction) | |
2134 | goto done; | |
2135 | ||
2136 | /* On some different transaction's list - should be | |
2137 | * the committing one */ | |
2138 | if (jinode->i_transaction) { | |
2139 | J_ASSERT(jinode->i_next_transaction == NULL); | |
2140 | J_ASSERT(jinode->i_transaction == | |
2141 | journal->j_committing_transaction); | |
2142 | jinode->i_next_transaction = transaction; | |
2143 | goto done; | |
2144 | } | |
2145 | /* Not on any transaction list... */ | |
2146 | J_ASSERT(!jinode->i_next_transaction); | |
2147 | jinode->i_transaction = transaction; | |
2148 | list_add(&jinode->i_list, &transaction->t_inode_list); | |
2149 | done: | |
2150 | spin_unlock(&journal->j_list_lock); | |
2151 | ||
2152 | return 0; | |
2153 | } | |
2154 | ||
2155 | /* | |
7f5aa215 JK |
2156 | * File truncate and transaction commit interact with each other in a |
2157 | * non-trivial way. If a transaction writing data block A is | |
2158 | * committing, we cannot discard the data by truncate until we have | |
2159 | * written them. Otherwise if we crashed after the transaction with | |
2160 | * write has committed but before the transaction with truncate has | |
2161 | * committed, we could see stale data in block A. This function is a | |
2162 | * helper to solve this problem. It starts writeout of the truncated | |
2163 | * part in case it is in the committing transaction. | |
2164 | * | |
2165 | * Filesystem code must call this function when inode is journaled in | |
2166 | * ordered mode before truncation happens and after the inode has been | |
2167 | * placed on orphan list with the new inode size. The second condition | |
2168 | * avoids the race that someone writes new data and we start | |
2169 | * committing the transaction after this function has been called but | |
2170 | * before a transaction for truncate is started (and furthermore it | |
2171 | * allows us to optimize the case where the addition to orphan list | |
2172 | * happens in the same transaction as write --- we don't have to write | |
2173 | * any data in such case). | |
c851ed54 | 2174 | */ |
7f5aa215 JK |
2175 | int jbd2_journal_begin_ordered_truncate(journal_t *journal, |
2176 | struct jbd2_inode *jinode, | |
c851ed54 JK |
2177 | loff_t new_size) |
2178 | { | |
7f5aa215 | 2179 | transaction_t *inode_trans, *commit_trans; |
c851ed54 JK |
2180 | int ret = 0; |
2181 | ||
7f5aa215 JK |
2182 | /* This is a quick check to avoid locking if not necessary */ |
2183 | if (!jinode->i_transaction) | |
c851ed54 | 2184 | goto out; |
7f5aa215 JK |
2185 | /* Locks are here just to force reading of recent values, it is |
2186 | * enough that the transaction was not committing before we started | |
2187 | * a transaction adding the inode to orphan list */ | |
a931da6a | 2188 | read_lock(&journal->j_state_lock); |
c851ed54 | 2189 | commit_trans = journal->j_committing_transaction; |
a931da6a | 2190 | read_unlock(&journal->j_state_lock); |
7f5aa215 JK |
2191 | spin_lock(&journal->j_list_lock); |
2192 | inode_trans = jinode->i_transaction; | |
2193 | spin_unlock(&journal->j_list_lock); | |
2194 | if (inode_trans == commit_trans) { | |
2195 | ret = filemap_fdatawrite_range(jinode->i_vfs_inode->i_mapping, | |
c851ed54 JK |
2196 | new_size, LLONG_MAX); |
2197 | if (ret) | |
2198 | jbd2_journal_abort(journal, ret); | |
2199 | } | |
2200 | out: | |
2201 | return ret; | |
2202 | } |