blob: fb1ab9533b67277a557cd5f8ea9f7216b8284d4e [file] [log] [blame]
Dave Kleikamp470decc2006-10-11 01:20:57 -07001/*
Uwe Kleine-König58862692007-05-09 07:51:49 +02002 * linux/fs/jbd2/transaction.c
Dave Kleikamp470decc2006-10-11 01:20:57 -07003 *
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>
Mingming Caof7f4bcc2006-10-11 01:20:59 -070022#include <linux/jbd2.h>
Dave Kleikamp470decc2006-10-11 01:20:57 -070023#include <linux/errno.h>
24#include <linux/slab.h>
25#include <linux/timer.h>
Dave Kleikamp470decc2006-10-11 01:20:57 -070026#include <linux/mm.h>
27#include <linux/highmem.h>
Josef Bacike07f7182008-11-26 01:14:26 -050028#include <linux/hrtimer.h>
Theodore Ts'o47def822010-07-27 11:56:05 -040029#include <linux/backing-dev.h>
Randy Dunlap44705752011-10-27 04:05:13 -040030#include <linux/bug.h>
Theodore Ts'o47def822010-07-27 11:56:05 -040031#include <linux/module.h>
Dave Kleikamp470decc2006-10-11 01:20:57 -070032
Adrian Bunk7ddae862006-12-06 20:38:27 -080033static void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh);
Jan Karade1b7942011-06-13 15:38:22 -040034static void __jbd2_journal_unfile_buffer(struct journal_head *jh);
Adrian Bunk7ddae862006-12-06 20:38:27 -080035
Yongqiang Yang0c2022e2012-02-20 17:53:02 -050036static struct kmem_cache *transaction_cache;
37int __init jbd2_journal_init_transaction_cache(void)
38{
39 J_ASSERT(!transaction_cache);
40 transaction_cache = kmem_cache_create("jbd2_transaction_s",
41 sizeof(transaction_t),
42 0,
43 SLAB_HWCACHE_ALIGN|SLAB_TEMPORARY,
44 NULL);
45 if (transaction_cache)
46 return 0;
47 return -ENOMEM;
48}
49
50void jbd2_journal_destroy_transaction_cache(void)
51{
52 if (transaction_cache) {
53 kmem_cache_destroy(transaction_cache);
54 transaction_cache = NULL;
55 }
56}
57
58void jbd2_journal_free_transaction(transaction_t *transaction)
59{
60 if (unlikely(ZERO_OR_NULL_PTR(transaction)))
61 return;
62 kmem_cache_free(transaction_cache, transaction);
63}
64
Dave Kleikamp470decc2006-10-11 01:20:57 -070065/*
Mingming Caof7f4bcc2006-10-11 01:20:59 -070066 * jbd2_get_transaction: obtain a new transaction_t object.
Dave Kleikamp470decc2006-10-11 01:20:57 -070067 *
68 * Simply allocate and initialise a new transaction. Create it in
69 * RUNNING state and add it to the current journal (which should not
70 * have an existing running transaction: we only make a new transaction
71 * once we have started to commit the old one).
72 *
73 * Preconditions:
74 * The journal MUST be locked. We don't perform atomic mallocs on the
75 * new transaction and we can't block without protecting against other
76 * processes trying to touch the journal while it is in transition.
77 *
Dave Kleikamp470decc2006-10-11 01:20:57 -070078 */
79
80static transaction_t *
Mingming Caof7f4bcc2006-10-11 01:20:59 -070081jbd2_get_transaction(journal_t *journal, transaction_t *transaction)
Dave Kleikamp470decc2006-10-11 01:20:57 -070082{
83 transaction->t_journal = journal;
84 transaction->t_state = T_RUNNING;
Josef Bacike07f7182008-11-26 01:14:26 -050085 transaction->t_start_time = ktime_get();
Dave Kleikamp470decc2006-10-11 01:20:57 -070086 transaction->t_tid = journal->j_transaction_sequence++;
87 transaction->t_expires = jiffies + journal->j_commit_interval;
88 spin_lock_init(&transaction->t_handle_lock);
Theodore Ts'oa51dca92010-08-02 08:43:25 -040089 atomic_set(&transaction->t_updates, 0);
90 atomic_set(&transaction->t_outstanding_credits, 0);
Theodore Ts'o8dd42042010-08-03 21:38:29 -040091 atomic_set(&transaction->t_handle_count, 0);
Jan Karac851ed52008-07-11 19:27:31 -040092 INIT_LIST_HEAD(&transaction->t_inode_list);
Theodore Ts'o3e624fc2008-10-16 20:00:24 -040093 INIT_LIST_HEAD(&transaction->t_private_list);
Dave Kleikamp470decc2006-10-11 01:20:57 -070094
95 /* Set up the commit timer for the new transaction. */
Andreas Dilgerb1f485f2009-08-10 22:51:53 -040096 journal->j_commit_timer.expires = round_jiffies_up(transaction->t_expires);
Dave Kleikamp470decc2006-10-11 01:20:57 -070097 add_timer(&journal->j_commit_timer);
98
99 J_ASSERT(journal->j_running_transaction == NULL);
100 journal->j_running_transaction = transaction;
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500101 transaction->t_max_wait = 0;
102 transaction->t_start = jiffies;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700103
104 return transaction;
105}
106
107/*
108 * Handle management.
109 *
110 * A handle_t is an object which represents a single atomic update to a
111 * filesystem, and which tracks all of the modifications which form part
112 * of that one update.
113 */
114
115/*
Tao Ma28e35e42011-05-22 21:45:26 -0400116 * Update transaction's maximum wait time, if debugging is enabled.
Theodore Ts'o6d0bf002010-08-09 17:28:38 -0400117 *
118 * In order for t_max_wait to be reliable, it must be protected by a
119 * lock. But doing so will mean that start_this_handle() can not be
120 * run in parallel on SMP systems, which limits our scalability. So
121 * unless debugging is enabled, we no longer update t_max_wait, which
122 * means that maximum wait time reported by the jbd2_run_stats
123 * tracepoint will always be zero.
124 */
Tao Ma28e35e42011-05-22 21:45:26 -0400125static inline void update_t_max_wait(transaction_t *transaction,
126 unsigned long ts)
Theodore Ts'o6d0bf002010-08-09 17:28:38 -0400127{
128#ifdef CONFIG_JBD2_DEBUG
Theodore Ts'o6d0bf002010-08-09 17:28:38 -0400129 if (jbd2_journal_enable_debug &&
130 time_after(transaction->t_start, ts)) {
131 ts = jbd2_time_diff(ts, transaction->t_start);
132 spin_lock(&transaction->t_handle_lock);
133 if (ts > transaction->t_max_wait)
134 transaction->t_max_wait = ts;
135 spin_unlock(&transaction->t_handle_lock);
136 }
137#endif
138}
139
140/*
Dave Kleikamp470decc2006-10-11 01:20:57 -0700141 * start_this_handle: Given a handle, deal with any locking or stalling
142 * needed to make sure that there is enough journal space for the handle
143 * to begin. Attach the handle to a transaction and set up the
144 * transaction's buffer credits.
145 */
146
Theodore Ts'o47def822010-07-27 11:56:05 -0400147static int start_this_handle(journal_t *journal, handle_t *handle,
Dan Carpenterd2159fb2011-09-04 10:20:14 -0400148 gfp_t gfp_mask)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700149{
Theodore Ts'oe4471832011-02-12 08:18:24 -0500150 transaction_t *transaction, *new_transaction = NULL;
151 tid_t tid;
152 int needed, need_to_start;
153 int nblocks = handle->h_buffer_credits;
Tao Ma28e35e42011-05-22 21:45:26 -0400154 unsigned long ts = jiffies;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700155
156 if (nblocks > journal->j_max_transaction_buffers) {
Eryu Guanf2a44522011-11-01 19:09:18 -0400157 printk(KERN_ERR "JBD2: %s wants too many credits (%d > %d)\n",
Dave Kleikamp470decc2006-10-11 01:20:57 -0700158 current->comm, nblocks,
159 journal->j_max_transaction_buffers);
Theodore Ts'o47def822010-07-27 11:56:05 -0400160 return -ENOSPC;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700161 }
162
163alloc_transaction:
164 if (!journal->j_running_transaction) {
Wanlong Gaob2f4edb2012-06-01 00:10:32 -0400165 new_transaction = kmem_cache_zalloc(transaction_cache,
166 gfp_mask);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700167 if (!new_transaction) {
Theodore Ts'o47def822010-07-27 11:56:05 -0400168 /*
169 * If __GFP_FS is not present, then we may be
170 * being called from inside the fs writeback
171 * layer, so we MUST NOT fail. Since
172 * __GFP_NOFAIL is going away, we will arrange
173 * to retry the allocation ourselves.
174 */
175 if ((gfp_mask & __GFP_FS) == 0) {
176 congestion_wait(BLK_RW_ASYNC, HZ/50);
177 goto alloc_transaction;
178 }
179 return -ENOMEM;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700180 }
Dave Kleikamp470decc2006-10-11 01:20:57 -0700181 }
182
183 jbd_debug(3, "New handle %p going live.\n", handle);
184
Dave Kleikamp470decc2006-10-11 01:20:57 -0700185 /*
186 * We need to hold j_state_lock until t_updates has been incremented,
187 * for proper journal barrier handling
188 */
Theodore Ts'oa931da62010-08-03 21:35:12 -0400189repeat:
190 read_lock(&journal->j_state_lock);
Theodore Ts'o5c2178e2010-10-27 21:30:04 -0400191 BUG_ON(journal->j_flags & JBD2_UNMOUNT);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700192 if (is_journal_aborted(journal) ||
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700193 (journal->j_errno != 0 && !(journal->j_flags & JBD2_ACK_ERR))) {
Theodore Ts'oa931da62010-08-03 21:35:12 -0400194 read_unlock(&journal->j_state_lock);
Yongqiang Yang0c2022e2012-02-20 17:53:02 -0500195 jbd2_journal_free_transaction(new_transaction);
Theodore Ts'o47def822010-07-27 11:56:05 -0400196 return -EROFS;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700197 }
198
199 /* Wait on the journal's transaction barrier if necessary */
200 if (journal->j_barrier_count) {
Theodore Ts'oa931da62010-08-03 21:35:12 -0400201 read_unlock(&journal->j_state_lock);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700202 wait_event(journal->j_wait_transaction_locked,
203 journal->j_barrier_count == 0);
204 goto repeat;
205 }
206
207 if (!journal->j_running_transaction) {
Theodore Ts'oa931da62010-08-03 21:35:12 -0400208 read_unlock(&journal->j_state_lock);
209 if (!new_transaction)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700210 goto alloc_transaction;
Theodore Ts'oa931da62010-08-03 21:35:12 -0400211 write_lock(&journal->j_state_lock);
212 if (!journal->j_running_transaction) {
213 jbd2_get_transaction(journal, new_transaction);
214 new_transaction = NULL;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700215 }
Theodore Ts'oa931da62010-08-03 21:35:12 -0400216 write_unlock(&journal->j_state_lock);
217 goto repeat;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700218 }
219
220 transaction = journal->j_running_transaction;
221
222 /*
223 * If the current transaction is locked down for commit, wait for the
224 * lock to be released.
225 */
226 if (transaction->t_state == T_LOCKED) {
227 DEFINE_WAIT(wait);
228
229 prepare_to_wait(&journal->j_wait_transaction_locked,
230 &wait, TASK_UNINTERRUPTIBLE);
Theodore Ts'oa931da62010-08-03 21:35:12 -0400231 read_unlock(&journal->j_state_lock);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700232 schedule();
233 finish_wait(&journal->j_wait_transaction_locked, &wait);
234 goto repeat;
235 }
236
237 /*
238 * If there is not enough space left in the log to write all potential
239 * buffers requested by this operation, we need to stall pending a log
240 * checkpoint to free some more log space.
241 */
Theodore Ts'o8dd42042010-08-03 21:38:29 -0400242 needed = atomic_add_return(nblocks,
243 &transaction->t_outstanding_credits);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700244
245 if (needed > journal->j_max_transaction_buffers) {
246 /*
247 * If the current transaction is already too large, then start
248 * to commit it: we can then go back and attach this handle to
249 * a new transaction.
250 */
251 DEFINE_WAIT(wait);
252
253 jbd_debug(2, "Handle %p starting new commit...\n", handle);
Theodore Ts'o8dd42042010-08-03 21:38:29 -0400254 atomic_sub(nblocks, &transaction->t_outstanding_credits);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700255 prepare_to_wait(&journal->j_wait_transaction_locked, &wait,
256 TASK_UNINTERRUPTIBLE);
Theodore Ts'oe4471832011-02-12 08:18:24 -0500257 tid = transaction->t_tid;
258 need_to_start = !tid_geq(journal->j_commit_request, tid);
Theodore Ts'oa931da62010-08-03 21:35:12 -0400259 read_unlock(&journal->j_state_lock);
Theodore Ts'oe4471832011-02-12 08:18:24 -0500260 if (need_to_start)
261 jbd2_log_start_commit(journal, tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700262 schedule();
263 finish_wait(&journal->j_wait_transaction_locked, &wait);
264 goto repeat;
265 }
266
267 /*
268 * The commit code assumes that it can get enough log space
269 * without forcing a checkpoint. This is *critical* for
270 * correctness: a checkpoint of a buffer which is also
271 * associated with a committing transaction creates a deadlock,
272 * so commit simply cannot force through checkpoints.
273 *
274 * We must therefore ensure the necessary space in the journal
275 * *before* starting to dirty potentially checkpointed buffers
276 * in the new transaction.
277 *
278 * The worst part is, any transaction currently committing can
279 * reduce the free space arbitrarily. Be careful to account for
280 * those buffers when checkpointing.
281 */
282
283 /*
284 * @@@ AKPM: This seems rather over-defensive. We're giving commit
285 * a _lot_ of headroom: 1/4 of the journal plus the size of
286 * the committing transaction. Really, we only need to give it
287 * committing_transaction->t_outstanding_credits plus "enough" for
288 * the log control blocks.
Uwe Kleine-Königa34f0b32010-12-10 14:55:42 +0100289 * Also, this test is inconsistent with the matching one in
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700290 * jbd2_journal_extend().
Dave Kleikamp470decc2006-10-11 01:20:57 -0700291 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700292 if (__jbd2_log_space_left(journal) < jbd_space_needed(journal)) {
Dave Kleikamp470decc2006-10-11 01:20:57 -0700293 jbd_debug(2, "Handle %p waiting for checkpoint...\n", handle);
Theodore Ts'o8dd42042010-08-03 21:38:29 -0400294 atomic_sub(nblocks, &transaction->t_outstanding_credits);
Theodore Ts'oa931da62010-08-03 21:35:12 -0400295 read_unlock(&journal->j_state_lock);
296 write_lock(&journal->j_state_lock);
297 if (__jbd2_log_space_left(journal) < jbd_space_needed(journal))
298 __jbd2_log_wait_for_space(journal);
299 write_unlock(&journal->j_state_lock);
300 goto repeat;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700301 }
302
303 /* OK, account for the buffers that this operation expects to
Theodore Ts'o8dd42042010-08-03 21:38:29 -0400304 * use and add the handle to the running transaction.
Theodore Ts'o8dd42042010-08-03 21:38:29 -0400305 */
Tao Ma28e35e42011-05-22 21:45:26 -0400306 update_t_max_wait(transaction, ts);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700307 handle->h_transaction = transaction;
Theodore Ts'oa51dca92010-08-02 08:43:25 -0400308 atomic_inc(&transaction->t_updates);
Theodore Ts'o8dd42042010-08-03 21:38:29 -0400309 atomic_inc(&transaction->t_handle_count);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700310 jbd_debug(4, "Handle %p given %d credits (total %d, free %d)\n",
Theodore Ts'oa51dca92010-08-02 08:43:25 -0400311 handle, nblocks,
312 atomic_read(&transaction->t_outstanding_credits),
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700313 __jbd2_log_space_left(journal));
Theodore Ts'oa931da62010-08-03 21:35:12 -0400314 read_unlock(&journal->j_state_lock);
Jan Kara9599b0e2009-08-17 21:23:17 -0400315
316 lock_map_acquire(&handle->h_lockdep_map);
Yongqiang Yang0c2022e2012-02-20 17:53:02 -0500317 jbd2_journal_free_transaction(new_transaction);
Theodore Ts'o47def822010-07-27 11:56:05 -0400318 return 0;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700319}
320
Mingming Cao7b751062008-01-28 23:58:27 -0500321static struct lock_class_key jbd2_handle_key;
322
Dave Kleikamp470decc2006-10-11 01:20:57 -0700323/* Allocate a new handle. This should probably be in a slab... */
324static handle_t *new_handle(int nblocks)
325{
Mingming Caoaf1e76d2007-10-16 18:38:25 -0400326 handle_t *handle = jbd2_alloc_handle(GFP_NOFS);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700327 if (!handle)
328 return NULL;
329 memset(handle, 0, sizeof(*handle));
330 handle->h_buffer_credits = nblocks;
331 handle->h_ref = 1;
332
Mingming Cao7b751062008-01-28 23:58:27 -0500333 lockdep_init_map(&handle->h_lockdep_map, "jbd2_handle",
334 &jbd2_handle_key, 0);
335
Dave Kleikamp470decc2006-10-11 01:20:57 -0700336 return handle;
337}
338
339/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700340 * handle_t *jbd2_journal_start() - Obtain a new handle.
Dave Kleikamp470decc2006-10-11 01:20:57 -0700341 * @journal: Journal to start transaction on.
342 * @nblocks: number of block buffer we might modify
343 *
344 * We make sure that the transaction can guarantee at least nblocks of
345 * modified buffers in the log. We block until the log can guarantee
346 * that much space.
347 *
348 * This function is visible to journal users (like ext3fs), so is not
349 * called with the journal already locked.
350 *
Eryu Guanc8675162011-05-24 17:09:58 -0400351 * Return a pointer to a newly allocated handle, or an ERR_PTR() value
352 * on failure.
Dave Kleikamp470decc2006-10-11 01:20:57 -0700353 */
Dan Carpenterd2159fb2011-09-04 10:20:14 -0400354handle_t *jbd2__journal_start(journal_t *journal, int nblocks, gfp_t gfp_mask)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700355{
356 handle_t *handle = journal_current_handle();
357 int err;
358
359 if (!journal)
360 return ERR_PTR(-EROFS);
361
362 if (handle) {
363 J_ASSERT(handle->h_transaction->t_journal == journal);
364 handle->h_ref++;
365 return handle;
366 }
367
368 handle = new_handle(nblocks);
369 if (!handle)
370 return ERR_PTR(-ENOMEM);
371
372 current->journal_info = handle;
373
Theodore Ts'o47def822010-07-27 11:56:05 -0400374 err = start_this_handle(journal, handle, gfp_mask);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700375 if (err < 0) {
Mingming Caoaf1e76d2007-10-16 18:38:25 -0400376 jbd2_free_handle(handle);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700377 current->journal_info = NULL;
378 handle = ERR_PTR(err);
379 }
380 return handle;
381}
Theodore Ts'o47def822010-07-27 11:56:05 -0400382EXPORT_SYMBOL(jbd2__journal_start);
383
384
385handle_t *jbd2_journal_start(journal_t *journal, int nblocks)
386{
387 return jbd2__journal_start(journal, nblocks, GFP_NOFS);
388}
389EXPORT_SYMBOL(jbd2_journal_start);
390
Dave Kleikamp470decc2006-10-11 01:20:57 -0700391
392/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700393 * int jbd2_journal_extend() - extend buffer credits.
Dave Kleikamp470decc2006-10-11 01:20:57 -0700394 * @handle: handle to 'extend'
395 * @nblocks: nr blocks to try to extend by.
396 *
397 * Some transactions, such as large extends and truncates, can be done
398 * atomically all at once or in several stages. The operation requests
399 * a credit for a number of buffer modications in advance, but can
400 * extend its credit if it needs more.
401 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700402 * jbd2_journal_extend tries to give the running handle more buffer credits.
Dave Kleikamp470decc2006-10-11 01:20:57 -0700403 * It does not guarantee that allocation - this is a best-effort only.
404 * The calling process MUST be able to deal cleanly with a failure to
405 * extend here.
406 *
407 * Return 0 on success, non-zero on failure.
408 *
409 * return code < 0 implies an error
410 * return code > 0 implies normal transaction-full status.
411 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700412int jbd2_journal_extend(handle_t *handle, int nblocks)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700413{
414 transaction_t *transaction = handle->h_transaction;
415 journal_t *journal = transaction->t_journal;
416 int result;
417 int wanted;
418
419 result = -EIO;
420 if (is_handle_aborted(handle))
421 goto out;
422
423 result = 1;
424
Theodore Ts'oa931da62010-08-03 21:35:12 -0400425 read_lock(&journal->j_state_lock);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700426
427 /* Don't extend a locked-down transaction! */
428 if (handle->h_transaction->t_state != T_RUNNING) {
429 jbd_debug(3, "denied handle %p %d blocks: "
430 "transaction not running\n", handle, nblocks);
431 goto error_out;
432 }
433
434 spin_lock(&transaction->t_handle_lock);
Theodore Ts'oa51dca92010-08-02 08:43:25 -0400435 wanted = atomic_read(&transaction->t_outstanding_credits) + nblocks;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700436
437 if (wanted > journal->j_max_transaction_buffers) {
438 jbd_debug(3, "denied handle %p %d blocks: "
439 "transaction too large\n", handle, nblocks);
440 goto unlock;
441 }
442
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700443 if (wanted > __jbd2_log_space_left(journal)) {
Dave Kleikamp470decc2006-10-11 01:20:57 -0700444 jbd_debug(3, "denied handle %p %d blocks: "
445 "insufficient log space\n", handle, nblocks);
446 goto unlock;
447 }
448
449 handle->h_buffer_credits += nblocks;
Theodore Ts'oa51dca92010-08-02 08:43:25 -0400450 atomic_add(nblocks, &transaction->t_outstanding_credits);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700451 result = 0;
452
453 jbd_debug(3, "extended handle %p by %d\n", handle, nblocks);
454unlock:
455 spin_unlock(&transaction->t_handle_lock);
456error_out:
Theodore Ts'oa931da62010-08-03 21:35:12 -0400457 read_unlock(&journal->j_state_lock);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700458out:
459 return result;
460}
461
462
463/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700464 * int jbd2_journal_restart() - restart a handle .
Dave Kleikamp470decc2006-10-11 01:20:57 -0700465 * @handle: handle to restart
466 * @nblocks: nr credits requested
467 *
468 * Restart a handle for a multi-transaction filesystem
469 * operation.
470 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700471 * If the jbd2_journal_extend() call above fails to grant new buffer credits
472 * to a running handle, a call to jbd2_journal_restart will commit the
Dave Kleikamp470decc2006-10-11 01:20:57 -0700473 * handle's transaction so far and reattach the handle to a new
474 * transaction capabable of guaranteeing the requested number of
475 * credits.
476 */
Dan Carpenterd2159fb2011-09-04 10:20:14 -0400477int jbd2__journal_restart(handle_t *handle, int nblocks, gfp_t gfp_mask)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700478{
479 transaction_t *transaction = handle->h_transaction;
480 journal_t *journal = transaction->t_journal;
Theodore Ts'oe4471832011-02-12 08:18:24 -0500481 tid_t tid;
482 int need_to_start, ret;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700483
484 /* If we've had an abort of any type, don't even think about
485 * actually doing the restart! */
486 if (is_handle_aborted(handle))
487 return 0;
488
489 /*
490 * First unlink the handle from its current transaction, and start the
491 * commit on that.
492 */
Theodore Ts'oa51dca92010-08-02 08:43:25 -0400493 J_ASSERT(atomic_read(&transaction->t_updates) > 0);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700494 J_ASSERT(journal_current_handle() == handle);
495
Theodore Ts'oa931da62010-08-03 21:35:12 -0400496 read_lock(&journal->j_state_lock);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700497 spin_lock(&transaction->t_handle_lock);
Theodore Ts'oa51dca92010-08-02 08:43:25 -0400498 atomic_sub(handle->h_buffer_credits,
499 &transaction->t_outstanding_credits);
500 if (atomic_dec_and_test(&transaction->t_updates))
Dave Kleikamp470decc2006-10-11 01:20:57 -0700501 wake_up(&journal->j_wait_updates);
502 spin_unlock(&transaction->t_handle_lock);
503
504 jbd_debug(2, "restarting handle %p\n", handle);
Theodore Ts'oe4471832011-02-12 08:18:24 -0500505 tid = transaction->t_tid;
506 need_to_start = !tid_geq(journal->j_commit_request, tid);
Theodore Ts'oa931da62010-08-03 21:35:12 -0400507 read_unlock(&journal->j_state_lock);
Theodore Ts'oe4471832011-02-12 08:18:24 -0500508 if (need_to_start)
509 jbd2_log_start_commit(journal, tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700510
Jan Kara9599b0e2009-08-17 21:23:17 -0400511 lock_map_release(&handle->h_lockdep_map);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700512 handle->h_buffer_credits = nblocks;
Theodore Ts'o47def822010-07-27 11:56:05 -0400513 ret = start_this_handle(journal, handle, gfp_mask);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700514 return ret;
515}
Theodore Ts'o47def822010-07-27 11:56:05 -0400516EXPORT_SYMBOL(jbd2__journal_restart);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700517
518
Theodore Ts'o47def822010-07-27 11:56:05 -0400519int jbd2_journal_restart(handle_t *handle, int nblocks)
520{
521 return jbd2__journal_restart(handle, nblocks, GFP_NOFS);
522}
523EXPORT_SYMBOL(jbd2_journal_restart);
524
Dave Kleikamp470decc2006-10-11 01:20:57 -0700525/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700526 * void jbd2_journal_lock_updates () - establish a transaction barrier.
Dave Kleikamp470decc2006-10-11 01:20:57 -0700527 * @journal: Journal to establish a barrier on.
528 *
529 * This locks out any further updates from being started, and blocks
530 * until all existing updates have completed, returning only once the
531 * journal is in a quiescent state with no updates running.
532 *
533 * The journal lock should not be held on entry.
534 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700535void jbd2_journal_lock_updates(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700536{
537 DEFINE_WAIT(wait);
538
Theodore Ts'oa931da62010-08-03 21:35:12 -0400539 write_lock(&journal->j_state_lock);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700540 ++journal->j_barrier_count;
541
542 /* Wait until there are no running updates */
543 while (1) {
544 transaction_t *transaction = journal->j_running_transaction;
545
546 if (!transaction)
547 break;
548
549 spin_lock(&transaction->t_handle_lock);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700550 prepare_to_wait(&journal->j_wait_updates, &wait,
551 TASK_UNINTERRUPTIBLE);
Jan Kara9837d8e2012-01-04 22:03:11 -0500552 if (!atomic_read(&transaction->t_updates)) {
553 spin_unlock(&transaction->t_handle_lock);
554 finish_wait(&journal->j_wait_updates, &wait);
555 break;
556 }
Dave Kleikamp470decc2006-10-11 01:20:57 -0700557 spin_unlock(&transaction->t_handle_lock);
Theodore Ts'oa931da62010-08-03 21:35:12 -0400558 write_unlock(&journal->j_state_lock);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700559 schedule();
560 finish_wait(&journal->j_wait_updates, &wait);
Theodore Ts'oa931da62010-08-03 21:35:12 -0400561 write_lock(&journal->j_state_lock);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700562 }
Theodore Ts'oa931da62010-08-03 21:35:12 -0400563 write_unlock(&journal->j_state_lock);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700564
565 /*
566 * We have now established a barrier against other normal updates, but
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700567 * we also need to barrier against other jbd2_journal_lock_updates() calls
Dave Kleikamp470decc2006-10-11 01:20:57 -0700568 * to make sure that we serialise special journal-locked operations
569 * too.
570 */
571 mutex_lock(&journal->j_barrier);
572}
573
574/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700575 * void jbd2_journal_unlock_updates (journal_t* journal) - release barrier
Dave Kleikamp470decc2006-10-11 01:20:57 -0700576 * @journal: Journal to release the barrier on.
577 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700578 * Release a transaction barrier obtained with jbd2_journal_lock_updates().
Dave Kleikamp470decc2006-10-11 01:20:57 -0700579 *
580 * Should be called without the journal lock held.
581 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700582void jbd2_journal_unlock_updates (journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700583{
584 J_ASSERT(journal->j_barrier_count != 0);
585
586 mutex_unlock(&journal->j_barrier);
Theodore Ts'oa931da62010-08-03 21:35:12 -0400587 write_lock(&journal->j_state_lock);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700588 --journal->j_barrier_count;
Theodore Ts'oa931da62010-08-03 21:35:12 -0400589 write_unlock(&journal->j_state_lock);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700590 wake_up(&journal->j_wait_transaction_locked);
591}
592
Jan Karaf91d1d02009-07-13 16:16:20 -0400593static void warn_dirty_buffer(struct buffer_head *bh)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700594{
Jan Karaf91d1d02009-07-13 16:16:20 -0400595 char b[BDEVNAME_SIZE];
Dave Kleikamp470decc2006-10-11 01:20:57 -0700596
Jan Karaf91d1d02009-07-13 16:16:20 -0400597 printk(KERN_WARNING
Eryu Guanf2a44522011-11-01 19:09:18 -0400598 "JBD2: Spotted dirty metadata buffer (dev = %s, blocknr = %llu). "
Jan Karaf91d1d02009-07-13 16:16:20 -0400599 "There's a risk of filesystem corruption in case of system "
600 "crash.\n",
601 bdevname(bh->b_bdev, b), (unsigned long long)bh->b_blocknr);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700602}
603
604/*
605 * If the buffer is already part of the current transaction, then there
606 * is nothing we need to do. If it is already part of a prior
607 * transaction which we are still committing to disk, then we need to
608 * make sure that we do not overwrite the old copy: we do copy-out to
609 * preserve the copy going to disk. We also account the buffer against
610 * the handle's metadata buffer credits (unless the buffer is already
611 * part of the transaction, that is).
612 *
613 */
614static int
615do_get_write_access(handle_t *handle, struct journal_head *jh,
616 int force_copy)
617{
618 struct buffer_head *bh;
619 transaction_t *transaction;
620 journal_t *journal;
621 int error;
622 char *frozen_buffer = NULL;
623 int need_copy = 0;
624
625 if (is_handle_aborted(handle))
626 return -EROFS;
627
628 transaction = handle->h_transaction;
629 journal = transaction->t_journal;
630
Theodore Ts'ocfef2c62010-12-18 13:07:34 -0500631 jbd_debug(5, "journal_head %p, force_copy %d\n", jh, force_copy);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700632
633 JBUFFER_TRACE(jh, "entry");
634repeat:
635 bh = jh2bh(jh);
636
637 /* @@@ Need to check for errors here at some point. */
638
639 lock_buffer(bh);
640 jbd_lock_bh_state(bh);
641
642 /* We now hold the buffer lock so it is safe to query the buffer
643 * state. Is the buffer dirty?
644 *
645 * If so, there are two possibilities. The buffer may be
646 * non-journaled, and undergoing a quite legitimate writeback.
647 * Otherwise, it is journaled, and we don't expect dirty buffers
648 * in that state (the buffers should be marked JBD_Dirty
649 * instead.) So either the IO is being done under our own
650 * control and this is a bug, or it's a third party IO such as
651 * dump(8) (which may leave the buffer scheduled for read ---
652 * ie. locked but not dirty) or tune2fs (which may actually have
653 * the buffer dirtied, ugh.) */
654
655 if (buffer_dirty(bh)) {
656 /*
657 * First question: is this buffer already part of the current
658 * transaction or the existing committing transaction?
659 */
660 if (jh->b_transaction) {
661 J_ASSERT_JH(jh,
662 jh->b_transaction == transaction ||
663 jh->b_transaction ==
664 journal->j_committing_transaction);
665 if (jh->b_next_transaction)
666 J_ASSERT_JH(jh, jh->b_next_transaction ==
667 transaction);
Jan Karaf91d1d02009-07-13 16:16:20 -0400668 warn_dirty_buffer(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700669 }
670 /*
671 * In any case we need to clean the dirty flag and we must
672 * do it under the buffer lock to be sure we don't race
673 * with running write-out.
674 */
Jan Karaf91d1d02009-07-13 16:16:20 -0400675 JBUFFER_TRACE(jh, "Journalling dirty buffer");
676 clear_buffer_dirty(bh);
677 set_buffer_jbddirty(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700678 }
679
680 unlock_buffer(bh);
681
682 error = -EROFS;
683 if (is_handle_aborted(handle)) {
684 jbd_unlock_bh_state(bh);
685 goto out;
686 }
687 error = 0;
688
689 /*
690 * The buffer is already part of this transaction if b_transaction or
691 * b_next_transaction points to it
692 */
693 if (jh->b_transaction == transaction ||
694 jh->b_next_transaction == transaction)
695 goto done;
696
697 /*
Josef Bacik9fc7c632008-04-17 10:38:59 -0400698 * this is the first time this transaction is touching this buffer,
699 * reset the modified flag
700 */
701 jh->b_modified = 0;
702
703 /*
Dave Kleikamp470decc2006-10-11 01:20:57 -0700704 * If there is already a copy-out version of this buffer, then we don't
705 * need to make another one
706 */
707 if (jh->b_frozen_data) {
708 JBUFFER_TRACE(jh, "has frozen data");
709 J_ASSERT_JH(jh, jh->b_next_transaction == NULL);
710 jh->b_next_transaction = transaction;
711 goto done;
712 }
713
714 /* Is there data here we need to preserve? */
715
716 if (jh->b_transaction && jh->b_transaction != transaction) {
717 JBUFFER_TRACE(jh, "owned by older transaction");
718 J_ASSERT_JH(jh, jh->b_next_transaction == NULL);
719 J_ASSERT_JH(jh, jh->b_transaction ==
720 journal->j_committing_transaction);
721
722 /* There is one case we have to be very careful about.
723 * If the committing transaction is currently writing
724 * this buffer out to disk and has NOT made a copy-out,
725 * then we cannot modify the buffer contents at all
726 * right now. The essence of copy-out is that it is the
727 * extra copy, not the primary copy, which gets
728 * journaled. If the primary copy is already going to
729 * disk then we cannot do copy-out here. */
730
731 if (jh->b_jlist == BJ_Shadow) {
732 DEFINE_WAIT_BIT(wait, &bh->b_state, BH_Unshadow);
733 wait_queue_head_t *wqh;
734
735 wqh = bit_waitqueue(&bh->b_state, BH_Unshadow);
736
737 JBUFFER_TRACE(jh, "on shadow: sleep");
738 jbd_unlock_bh_state(bh);
739 /* commit wakes up all shadow buffers after IO */
740 for ( ; ; ) {
741 prepare_to_wait(wqh, &wait.wait,
742 TASK_UNINTERRUPTIBLE);
743 if (jh->b_jlist != BJ_Shadow)
744 break;
745 schedule();
746 }
747 finish_wait(wqh, &wait.wait);
748 goto repeat;
749 }
750
751 /* Only do the copy if the currently-owning transaction
752 * still needs it. If it is on the Forget list, the
753 * committing transaction is past that stage. The
754 * buffer had better remain locked during the kmalloc,
755 * but that should be true --- we hold the journal lock
756 * still and the buffer is already on the BUF_JOURNAL
757 * list so won't be flushed.
758 *
759 * Subtle point, though: if this is a get_undo_access,
760 * then we will be relying on the frozen_data to contain
761 * the new value of the committed_data record after the
762 * transaction, so we HAVE to force the frozen_data copy
763 * in that case. */
764
765 if (jh->b_jlist != BJ_Forget || force_copy) {
766 JBUFFER_TRACE(jh, "generate frozen data");
767 if (!frozen_buffer) {
768 JBUFFER_TRACE(jh, "allocate memory for buffer");
769 jbd_unlock_bh_state(bh);
770 frozen_buffer =
Mingming Caoaf1e76d2007-10-16 18:38:25 -0400771 jbd2_alloc(jh2bh(jh)->b_size,
Dave Kleikamp470decc2006-10-11 01:20:57 -0700772 GFP_NOFS);
773 if (!frozen_buffer) {
774 printk(KERN_EMERG
775 "%s: OOM for frozen_buffer\n",
Harvey Harrison329d2912008-04-17 10:38:59 -0400776 __func__);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700777 JBUFFER_TRACE(jh, "oom!");
778 error = -ENOMEM;
779 jbd_lock_bh_state(bh);
780 goto done;
781 }
782 goto repeat;
783 }
784 jh->b_frozen_data = frozen_buffer;
785 frozen_buffer = NULL;
786 need_copy = 1;
787 }
788 jh->b_next_transaction = transaction;
789 }
790
791
792 /*
793 * Finally, if the buffer is not journaled right now, we need to make
794 * sure it doesn't get written to disk before the caller actually
795 * commits the new data
796 */
797 if (!jh->b_transaction) {
798 JBUFFER_TRACE(jh, "no transaction");
799 J_ASSERT_JH(jh, !jh->b_next_transaction);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700800 JBUFFER_TRACE(jh, "file as BJ_Reserved");
801 spin_lock(&journal->j_list_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700802 __jbd2_journal_file_buffer(jh, transaction, BJ_Reserved);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700803 spin_unlock(&journal->j_list_lock);
804 }
805
806done:
807 if (need_copy) {
808 struct page *page;
809 int offset;
810 char *source;
811
812 J_EXPECT_JH(jh, buffer_uptodate(jh2bh(jh)),
813 "Possible IO failure.\n");
814 page = jh2bh(jh)->b_page;
Theodore Ts'oa1dd5332010-12-18 13:13:40 -0500815 offset = offset_in_page(jh2bh(jh)->b_data);
Cong Wang303a8f22011-11-25 23:14:31 +0800816 source = kmap_atomic(page);
Jan Kara13ceef02010-07-14 07:56:33 +0200817 /* Fire data frozen trigger just before we copy the data */
818 jbd2_buffer_frozen_trigger(jh, source + offset,
819 jh->b_triggers);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700820 memcpy(jh->b_frozen_data, source+offset, jh2bh(jh)->b_size);
Cong Wang303a8f22011-11-25 23:14:31 +0800821 kunmap_atomic(source);
Joel Beckere06c8222008-09-11 15:35:47 -0700822
823 /*
824 * Now that the frozen data is saved off, we need to store
825 * any matching triggers.
826 */
827 jh->b_frozen_triggers = jh->b_triggers;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700828 }
829 jbd_unlock_bh_state(bh);
830
831 /*
832 * If we are about to journal a buffer, then any revoke pending on it is
833 * no longer valid
834 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700835 jbd2_journal_cancel_revoke(handle, jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700836
837out:
838 if (unlikely(frozen_buffer)) /* It's usually NULL */
Mingming Caoaf1e76d2007-10-16 18:38:25 -0400839 jbd2_free(frozen_buffer, bh->b_size);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700840
841 JBUFFER_TRACE(jh, "exit");
842 return error;
843}
844
845/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700846 * int jbd2_journal_get_write_access() - notify intent to modify a buffer for metadata (not data) update.
Dave Kleikamp470decc2006-10-11 01:20:57 -0700847 * @handle: transaction to add buffer modifications to
848 * @bh: bh to be used for metadata writes
Dave Kleikamp470decc2006-10-11 01:20:57 -0700849 *
850 * Returns an error code or 0 on success.
851 *
852 * In full data journalling mode the buffer may be of type BJ_AsyncData,
853 * because we're write()ing a buffer which is also part of a shared mapping.
854 */
855
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700856int jbd2_journal_get_write_access(handle_t *handle, struct buffer_head *bh)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700857{
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700858 struct journal_head *jh = jbd2_journal_add_journal_head(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700859 int rc;
860
861 /* We do not want to get caught playing with fields which the
862 * log thread also manipulates. Make sure that the buffer
863 * completes any outstanding IO before proceeding. */
864 rc = do_get_write_access(handle, jh, 0);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700865 jbd2_journal_put_journal_head(jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700866 return rc;
867}
868
869
870/*
871 * When the user wants to journal a newly created buffer_head
872 * (ie. getblk() returned a new buffer and we are going to populate it
873 * manually rather than reading off disk), then we need to keep the
874 * buffer_head locked until it has been completely filled with new
875 * data. In this case, we should be able to make the assertion that
876 * the bh is not already part of an existing transaction.
877 *
878 * The buffer should already be locked by the caller by this point.
879 * There is no lock ranking violation: it was a newly created,
880 * unlocked buffer beforehand. */
881
882/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700883 * int jbd2_journal_get_create_access () - notify intent to use newly created bh
Dave Kleikamp470decc2006-10-11 01:20:57 -0700884 * @handle: transaction to new buffer to
885 * @bh: new buffer.
886 *
887 * Call this if you create a new bh.
888 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700889int jbd2_journal_get_create_access(handle_t *handle, struct buffer_head *bh)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700890{
891 transaction_t *transaction = handle->h_transaction;
892 journal_t *journal = transaction->t_journal;
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700893 struct journal_head *jh = jbd2_journal_add_journal_head(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700894 int err;
895
896 jbd_debug(5, "journal_head %p\n", jh);
897 err = -EROFS;
898 if (is_handle_aborted(handle))
899 goto out;
900 err = 0;
901
902 JBUFFER_TRACE(jh, "entry");
903 /*
904 * The buffer may already belong to this transaction due to pre-zeroing
905 * in the filesystem's new_block code. It may also be on the previous,
906 * committing transaction's lists, but it HAS to be in Forget state in
907 * that case: the transaction must have deleted the buffer for it to be
908 * reused here.
909 */
910 jbd_lock_bh_state(bh);
911 spin_lock(&journal->j_list_lock);
912 J_ASSERT_JH(jh, (jh->b_transaction == transaction ||
913 jh->b_transaction == NULL ||
914 (jh->b_transaction == journal->j_committing_transaction &&
915 jh->b_jlist == BJ_Forget)));
916
917 J_ASSERT_JH(jh, jh->b_next_transaction == NULL);
918 J_ASSERT_JH(jh, buffer_locked(jh2bh(jh)));
919
920 if (jh->b_transaction == NULL) {
Jan Karaf91d1d02009-07-13 16:16:20 -0400921 /*
922 * Previous jbd2_journal_forget() could have left the buffer
923 * with jbddirty bit set because it was being committed. When
924 * the commit finished, we've filed the buffer for
925 * checkpointing and marked it dirty. Now we are reallocating
926 * the buffer so the transaction freeing it must have
927 * committed and so it's safe to clear the dirty bit.
928 */
929 clear_buffer_dirty(jh2bh(jh));
Josef Bacik9fc7c632008-04-17 10:38:59 -0400930 /* first access by this transaction */
931 jh->b_modified = 0;
932
Dave Kleikamp470decc2006-10-11 01:20:57 -0700933 JBUFFER_TRACE(jh, "file as BJ_Reserved");
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700934 __jbd2_journal_file_buffer(jh, transaction, BJ_Reserved);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700935 } else if (jh->b_transaction == journal->j_committing_transaction) {
Josef Bacik9fc7c632008-04-17 10:38:59 -0400936 /* first access by this transaction */
937 jh->b_modified = 0;
938
Dave Kleikamp470decc2006-10-11 01:20:57 -0700939 JBUFFER_TRACE(jh, "set next transaction");
940 jh->b_next_transaction = transaction;
941 }
942 spin_unlock(&journal->j_list_lock);
943 jbd_unlock_bh_state(bh);
944
945 /*
946 * akpm: I added this. ext3_alloc_branch can pick up new indirect
947 * blocks which contain freed but then revoked metadata. We need
948 * to cancel the revoke in case we end up freeing it yet again
949 * and the reallocating as data - this would cause a second revoke,
950 * which hits an assertion error.
951 */
952 JBUFFER_TRACE(jh, "cancelling revoke");
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700953 jbd2_journal_cancel_revoke(handle, jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700954out:
Ding Dinghua3991b402011-05-25 17:43:48 -0400955 jbd2_journal_put_journal_head(jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700956 return err;
957}
958
959/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700960 * int jbd2_journal_get_undo_access() - Notify intent to modify metadata with
Dave Kleikamp470decc2006-10-11 01:20:57 -0700961 * non-rewindable consequences
962 * @handle: transaction
963 * @bh: buffer to undo
Dave Kleikamp470decc2006-10-11 01:20:57 -0700964 *
965 * Sometimes there is a need to distinguish between metadata which has
966 * been committed to disk and that which has not. The ext3fs code uses
967 * this for freeing and allocating space, we have to make sure that we
968 * do not reuse freed space until the deallocation has been committed,
969 * since if we overwrote that space we would make the delete
970 * un-rewindable in case of a crash.
971 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700972 * To deal with that, jbd2_journal_get_undo_access requests write access to a
Dave Kleikamp470decc2006-10-11 01:20:57 -0700973 * buffer for parts of non-rewindable operations such as delete
974 * operations on the bitmaps. The journaling code must keep a copy of
975 * the buffer's contents prior to the undo_access call until such time
976 * as we know that the buffer has definitely been committed to disk.
977 *
978 * We never need to know which transaction the committed data is part
979 * of, buffers touched here are guaranteed to be dirtied later and so
980 * will be committed to a new transaction in due course, at which point
981 * we can discard the old committed data pointer.
982 *
983 * Returns error number or 0 on success.
984 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700985int jbd2_journal_get_undo_access(handle_t *handle, struct buffer_head *bh)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700986{
987 int err;
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700988 struct journal_head *jh = jbd2_journal_add_journal_head(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700989 char *committed_data = NULL;
990
991 JBUFFER_TRACE(jh, "entry");
992
993 /*
994 * Do this first --- it can drop the journal lock, so we want to
995 * make sure that obtaining the committed_data is done
996 * atomically wrt. completion of any outstanding commits.
997 */
998 err = do_get_write_access(handle, jh, 1);
999 if (err)
1000 goto out;
1001
1002repeat:
1003 if (!jh->b_committed_data) {
Mingming Caoaf1e76d2007-10-16 18:38:25 -04001004 committed_data = jbd2_alloc(jh2bh(jh)->b_size, GFP_NOFS);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001005 if (!committed_data) {
1006 printk(KERN_EMERG "%s: No memory for committed data\n",
Harvey Harrison329d2912008-04-17 10:38:59 -04001007 __func__);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001008 err = -ENOMEM;
1009 goto out;
1010 }
1011 }
1012
1013 jbd_lock_bh_state(bh);
1014 if (!jh->b_committed_data) {
1015 /* Copy out the current buffer contents into the
1016 * preserved, committed copy. */
1017 JBUFFER_TRACE(jh, "generate b_committed data");
1018 if (!committed_data) {
1019 jbd_unlock_bh_state(bh);
1020 goto repeat;
1021 }
1022
1023 jh->b_committed_data = committed_data;
1024 committed_data = NULL;
1025 memcpy(jh->b_committed_data, bh->b_data, bh->b_size);
1026 }
1027 jbd_unlock_bh_state(bh);
1028out:
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001029 jbd2_journal_put_journal_head(jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001030 if (unlikely(committed_data))
Mingming Caoaf1e76d2007-10-16 18:38:25 -04001031 jbd2_free(committed_data, bh->b_size);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001032 return err;
1033}
1034
1035/**
Joel Beckere06c8222008-09-11 15:35:47 -07001036 * void jbd2_journal_set_triggers() - Add triggers for commit writeout
1037 * @bh: buffer to trigger on
1038 * @type: struct jbd2_buffer_trigger_type containing the trigger(s).
1039 *
1040 * Set any triggers on this journal_head. This is always safe, because
1041 * triggers for a committing buffer will be saved off, and triggers for
1042 * a running transaction will match the buffer in that transaction.
1043 *
1044 * Call with NULL to clear the triggers.
1045 */
1046void jbd2_journal_set_triggers(struct buffer_head *bh,
1047 struct jbd2_buffer_trigger_type *type)
1048{
1049 struct journal_head *jh = bh2jh(bh);
1050
1051 jh->b_triggers = type;
1052}
1053
Jan Kara13ceef02010-07-14 07:56:33 +02001054void jbd2_buffer_frozen_trigger(struct journal_head *jh, void *mapped_data,
Joel Beckere06c8222008-09-11 15:35:47 -07001055 struct jbd2_buffer_trigger_type *triggers)
1056{
1057 struct buffer_head *bh = jh2bh(jh);
1058
Jan Kara13ceef02010-07-14 07:56:33 +02001059 if (!triggers || !triggers->t_frozen)
Joel Beckere06c8222008-09-11 15:35:47 -07001060 return;
1061
Jan Kara13ceef02010-07-14 07:56:33 +02001062 triggers->t_frozen(triggers, bh, mapped_data, bh->b_size);
Joel Beckere06c8222008-09-11 15:35:47 -07001063}
1064
1065void jbd2_buffer_abort_trigger(struct journal_head *jh,
1066 struct jbd2_buffer_trigger_type *triggers)
1067{
1068 if (!triggers || !triggers->t_abort)
1069 return;
1070
1071 triggers->t_abort(triggers, jh2bh(jh));
1072}
1073
1074
1075
1076/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001077 * int jbd2_journal_dirty_metadata() - mark a buffer as containing dirty metadata
Dave Kleikamp470decc2006-10-11 01:20:57 -07001078 * @handle: transaction to add buffer to.
1079 * @bh: buffer to mark
1080 *
1081 * mark dirty metadata which needs to be journaled as part of the current
1082 * transaction.
1083 *
Theodore Ts'o9ea7a0d2011-09-04 10:18:14 -04001084 * The buffer must have previously had jbd2_journal_get_write_access()
1085 * called so that it has a valid journal_head attached to the buffer
1086 * head.
1087 *
Dave Kleikamp470decc2006-10-11 01:20:57 -07001088 * The buffer is placed on the transaction's metadata list and is marked
1089 * as belonging to the transaction.
1090 *
1091 * Returns error number or 0 on success.
1092 *
1093 * Special care needs to be taken if the buffer already belongs to the
1094 * current committing transaction (in which case we should have frozen
1095 * data present for that commit). In that case, we don't relink the
1096 * buffer: that only gets done when the old transaction finally
1097 * completes its commit.
1098 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001099int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001100{
1101 transaction_t *transaction = handle->h_transaction;
1102 journal_t *journal = transaction->t_journal;
1103 struct journal_head *jh = bh2jh(bh);
Theodore Ts'o9ea7a0d2011-09-04 10:18:14 -04001104 int ret = 0;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001105
1106 jbd_debug(5, "journal_head %p\n", jh);
1107 JBUFFER_TRACE(jh, "entry");
1108 if (is_handle_aborted(handle))
1109 goto out;
Theodore Ts'o9ea7a0d2011-09-04 10:18:14 -04001110 if (!buffer_jbd(bh)) {
1111 ret = -EUCLEAN;
1112 goto out;
1113 }
Dave Kleikamp470decc2006-10-11 01:20:57 -07001114
1115 jbd_lock_bh_state(bh);
1116
1117 if (jh->b_modified == 0) {
1118 /*
1119 * This buffer's got modified and becoming part
1120 * of the transaction. This needs to be done
1121 * once a transaction -bzzz
1122 */
1123 jh->b_modified = 1;
1124 J_ASSERT_JH(jh, handle->h_buffer_credits > 0);
1125 handle->h_buffer_credits--;
1126 }
1127
1128 /*
1129 * fastpath, to avoid expensive locking. If this buffer is already
1130 * on the running transaction's metadata list there is nothing to do.
1131 * Nobody can take it off again because there is a handle open.
1132 * I _think_ we're OK here with SMP barriers - a mistaken decision will
1133 * result in this test being false, so we go in and take the locks.
1134 */
1135 if (jh->b_transaction == transaction && jh->b_jlist == BJ_Metadata) {
1136 JBUFFER_TRACE(jh, "fastpath");
Theodore Ts'o9ea7a0d2011-09-04 10:18:14 -04001137 if (unlikely(jh->b_transaction !=
1138 journal->j_running_transaction)) {
1139 printk(KERN_EMERG "JBD: %s: "
1140 "jh->b_transaction (%llu, %p, %u) != "
1141 "journal->j_running_transaction (%p, %u)",
1142 journal->j_devname,
1143 (unsigned long long) bh->b_blocknr,
1144 jh->b_transaction,
1145 jh->b_transaction ? jh->b_transaction->t_tid : 0,
1146 journal->j_running_transaction,
1147 journal->j_running_transaction ?
1148 journal->j_running_transaction->t_tid : 0);
1149 ret = -EINVAL;
1150 }
Dave Kleikamp470decc2006-10-11 01:20:57 -07001151 goto out_unlock_bh;
1152 }
1153
1154 set_buffer_jbddirty(bh);
1155
1156 /*
1157 * Metadata already on the current transaction list doesn't
1158 * need to be filed. Metadata on another transaction's list must
1159 * be committing, and will be refiled once the commit completes:
1160 * leave it alone for now.
1161 */
1162 if (jh->b_transaction != transaction) {
1163 JBUFFER_TRACE(jh, "already on other transaction");
Theodore Ts'o9ea7a0d2011-09-04 10:18:14 -04001164 if (unlikely(jh->b_transaction !=
1165 journal->j_committing_transaction)) {
1166 printk(KERN_EMERG "JBD: %s: "
1167 "jh->b_transaction (%llu, %p, %u) != "
1168 "journal->j_committing_transaction (%p, %u)",
1169 journal->j_devname,
1170 (unsigned long long) bh->b_blocknr,
1171 jh->b_transaction,
1172 jh->b_transaction ? jh->b_transaction->t_tid : 0,
1173 journal->j_committing_transaction,
1174 journal->j_committing_transaction ?
1175 journal->j_committing_transaction->t_tid : 0);
1176 ret = -EINVAL;
1177 }
1178 if (unlikely(jh->b_next_transaction != transaction)) {
1179 printk(KERN_EMERG "JBD: %s: "
1180 "jh->b_next_transaction (%llu, %p, %u) != "
1181 "transaction (%p, %u)",
1182 journal->j_devname,
1183 (unsigned long long) bh->b_blocknr,
1184 jh->b_next_transaction,
1185 jh->b_next_transaction ?
1186 jh->b_next_transaction->t_tid : 0,
1187 transaction, transaction->t_tid);
1188 ret = -EINVAL;
1189 }
Dave Kleikamp470decc2006-10-11 01:20:57 -07001190 /* And this case is illegal: we can't reuse another
1191 * transaction's data buffer, ever. */
1192 goto out_unlock_bh;
1193 }
1194
1195 /* That test should have eliminated the following case: */
Mingming Cao40191912008-01-28 23:58:27 -05001196 J_ASSERT_JH(jh, jh->b_frozen_data == NULL);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001197
1198 JBUFFER_TRACE(jh, "file as BJ_Metadata");
1199 spin_lock(&journal->j_list_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001200 __jbd2_journal_file_buffer(jh, handle->h_transaction, BJ_Metadata);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001201 spin_unlock(&journal->j_list_lock);
1202out_unlock_bh:
1203 jbd_unlock_bh_state(bh);
1204out:
1205 JBUFFER_TRACE(jh, "exit");
Randy Dunlap44705752011-10-27 04:05:13 -04001206 WARN_ON(ret); /* All errors are bugs, so dump the stack */
Theodore Ts'o9ea7a0d2011-09-04 10:18:14 -04001207 return ret;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001208}
1209
1210/*
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001211 * jbd2_journal_release_buffer: undo a get_write_access without any buffer
Dave Kleikamp470decc2006-10-11 01:20:57 -07001212 * updates, if the update decided in the end that it didn't need access.
1213 *
1214 */
1215void
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001216jbd2_journal_release_buffer(handle_t *handle, struct buffer_head *bh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001217{
1218 BUFFER_TRACE(bh, "entry");
1219}
1220
1221/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001222 * void jbd2_journal_forget() - bforget() for potentially-journaled buffers.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001223 * @handle: transaction handle
1224 * @bh: bh to 'forget'
1225 *
1226 * We can only do the bforget if there are no commits pending against the
1227 * buffer. If the buffer is dirty in the current running transaction we
1228 * can safely unlink it.
1229 *
1230 * bh may not be a journalled buffer at all - it may be a non-JBD
1231 * buffer which came off the hashtable. Check for this.
1232 *
1233 * Decrements bh->b_count by one.
1234 *
1235 * Allow this call even if the handle has aborted --- it may be part of
1236 * the caller's cleanup after an abort.
1237 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001238int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001239{
1240 transaction_t *transaction = handle->h_transaction;
1241 journal_t *journal = transaction->t_journal;
1242 struct journal_head *jh;
1243 int drop_reserve = 0;
1244 int err = 0;
Josef Bacik1dfc3222008-04-17 10:38:59 -04001245 int was_modified = 0;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001246
1247 BUFFER_TRACE(bh, "entry");
1248
1249 jbd_lock_bh_state(bh);
1250 spin_lock(&journal->j_list_lock);
1251
1252 if (!buffer_jbd(bh))
1253 goto not_jbd;
1254 jh = bh2jh(bh);
1255
1256 /* Critical error: attempting to delete a bitmap buffer, maybe?
1257 * Don't do any jbd operations, and return an error. */
1258 if (!J_EXPECT_JH(jh, !jh->b_committed_data,
1259 "inconsistent data on disk")) {
1260 err = -EIO;
1261 goto not_jbd;
1262 }
1263
Josef Bacik1dfc3222008-04-17 10:38:59 -04001264 /* keep track of wether or not this transaction modified us */
1265 was_modified = jh->b_modified;
1266
Dave Kleikamp470decc2006-10-11 01:20:57 -07001267 /*
1268 * The buffer's going from the transaction, we must drop
1269 * all references -bzzz
1270 */
1271 jh->b_modified = 0;
1272
1273 if (jh->b_transaction == handle->h_transaction) {
1274 J_ASSERT_JH(jh, !jh->b_frozen_data);
1275
1276 /* If we are forgetting a buffer which is already part
1277 * of this transaction, then we can just drop it from
1278 * the transaction immediately. */
1279 clear_buffer_dirty(bh);
1280 clear_buffer_jbddirty(bh);
1281
1282 JBUFFER_TRACE(jh, "belongs to current transaction: unfile");
1283
Josef Bacik1dfc3222008-04-17 10:38:59 -04001284 /*
1285 * we only want to drop a reference if this transaction
1286 * modified the buffer
1287 */
1288 if (was_modified)
1289 drop_reserve = 1;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001290
1291 /*
1292 * We are no longer going to journal this buffer.
1293 * However, the commit of this transaction is still
1294 * important to the buffer: the delete that we are now
1295 * processing might obsolete an old log entry, so by
1296 * committing, we can satisfy the buffer's checkpoint.
1297 *
1298 * So, if we have a checkpoint on the buffer, we should
1299 * now refile the buffer on our BJ_Forget list so that
1300 * we know to remove the checkpoint after we commit.
1301 */
1302
1303 if (jh->b_cp_transaction) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001304 __jbd2_journal_temp_unlink_buffer(jh);
1305 __jbd2_journal_file_buffer(jh, transaction, BJ_Forget);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001306 } else {
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001307 __jbd2_journal_unfile_buffer(jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001308 if (!buffer_jbd(bh)) {
1309 spin_unlock(&journal->j_list_lock);
1310 jbd_unlock_bh_state(bh);
1311 __bforget(bh);
1312 goto drop;
1313 }
1314 }
1315 } else if (jh->b_transaction) {
1316 J_ASSERT_JH(jh, (jh->b_transaction ==
1317 journal->j_committing_transaction));
1318 /* However, if the buffer is still owned by a prior
1319 * (committing) transaction, we can't drop it yet... */
1320 JBUFFER_TRACE(jh, "belongs to older transaction");
1321 /* ... but we CAN drop it from the new transaction if we
1322 * have also modified it since the original commit. */
1323
1324 if (jh->b_next_transaction) {
1325 J_ASSERT(jh->b_next_transaction == transaction);
1326 jh->b_next_transaction = NULL;
Josef Bacik1dfc3222008-04-17 10:38:59 -04001327
1328 /*
1329 * only drop a reference if this transaction modified
1330 * the buffer
1331 */
1332 if (was_modified)
1333 drop_reserve = 1;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001334 }
1335 }
1336
1337not_jbd:
1338 spin_unlock(&journal->j_list_lock);
1339 jbd_unlock_bh_state(bh);
1340 __brelse(bh);
1341drop:
1342 if (drop_reserve) {
1343 /* no need to reserve log space for this block -bzzz */
1344 handle->h_buffer_credits++;
1345 }
1346 return err;
1347}
1348
1349/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001350 * int jbd2_journal_stop() - complete a transaction
Dave Kleikamp470decc2006-10-11 01:20:57 -07001351 * @handle: tranaction to complete.
1352 *
1353 * All done for a particular handle.
1354 *
1355 * There is not much action needed here. We just return any remaining
1356 * buffer credits to the transaction and remove the handle. The only
1357 * complication is that we need to start a commit operation if the
1358 * filesystem is marked for synchronous update.
1359 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001360 * jbd2_journal_stop itself will not usually return an error, but it may
Dave Kleikamp470decc2006-10-11 01:20:57 -07001361 * do so in unusual circumstances. In particular, expect it to
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001362 * return -EIO if a jbd2_journal_abort has been executed since the
Dave Kleikamp470decc2006-10-11 01:20:57 -07001363 * transaction began.
1364 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001365int jbd2_journal_stop(handle_t *handle)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001366{
1367 transaction_t *transaction = handle->h_transaction;
1368 journal_t *journal = transaction->t_journal;
Theodore Ts'oa51dca92010-08-02 08:43:25 -04001369 int err, wait_for_commit = 0;
1370 tid_t tid;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001371 pid_t pid;
1372
Dave Kleikamp470decc2006-10-11 01:20:57 -07001373 J_ASSERT(journal_current_handle() == handle);
1374
1375 if (is_handle_aborted(handle))
1376 err = -EIO;
OGAWA Hirofumi3e2a5322006-10-19 23:29:11 -07001377 else {
Theodore Ts'oa51dca92010-08-02 08:43:25 -04001378 J_ASSERT(atomic_read(&transaction->t_updates) > 0);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001379 err = 0;
OGAWA Hirofumi3e2a5322006-10-19 23:29:11 -07001380 }
Dave Kleikamp470decc2006-10-11 01:20:57 -07001381
1382 if (--handle->h_ref > 0) {
1383 jbd_debug(4, "h_ref %d -> %d\n", handle->h_ref + 1,
1384 handle->h_ref);
1385 return err;
1386 }
1387
1388 jbd_debug(4, "Handle %p going down\n", handle);
1389
1390 /*
1391 * Implement synchronous transaction batching. If the handle
1392 * was synchronous, don't force a commit immediately. Let's
Josef Bacike07f7182008-11-26 01:14:26 -05001393 * yield and let another thread piggyback onto this
1394 * transaction. Keep doing that while new threads continue to
1395 * arrive. It doesn't cost much - we're about to run a commit
1396 * and sleep on IO anyway. Speeds up many-threaded, many-dir
1397 * operations by 30x or more...
Dave Kleikamp470decc2006-10-11 01:20:57 -07001398 *
Josef Bacike07f7182008-11-26 01:14:26 -05001399 * We try and optimize the sleep time against what the
1400 * underlying disk can do, instead of having a static sleep
1401 * time. This is useful for the case where our storage is so
1402 * fast that it is more optimal to go ahead and force a flush
1403 * and wait for the transaction to be committed than it is to
1404 * wait for an arbitrary amount of time for new writers to
1405 * join the transaction. We achieve this by measuring how
1406 * long it takes to commit a transaction, and compare it with
1407 * how long this transaction has been running, and if run time
1408 * < commit time then we sleep for the delta and commit. This
1409 * greatly helps super fast disks that would see slowdowns as
1410 * more threads started doing fsyncs.
1411 *
1412 * But don't do this if this process was the most recent one
1413 * to perform a synchronous write. We do this to detect the
1414 * case where a single process is doing a stream of sync
1415 * writes. No point in waiting for joiners in that case.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001416 */
1417 pid = current->pid;
1418 if (handle->h_sync && journal->j_last_sync_writer != pid) {
Josef Bacike07f7182008-11-26 01:14:26 -05001419 u64 commit_time, trans_time;
1420
Dave Kleikamp470decc2006-10-11 01:20:57 -07001421 journal->j_last_sync_writer = pid;
Josef Bacike07f7182008-11-26 01:14:26 -05001422
Theodore Ts'oa931da62010-08-03 21:35:12 -04001423 read_lock(&journal->j_state_lock);
Josef Bacike07f7182008-11-26 01:14:26 -05001424 commit_time = journal->j_average_commit_time;
Theodore Ts'oa931da62010-08-03 21:35:12 -04001425 read_unlock(&journal->j_state_lock);
Josef Bacike07f7182008-11-26 01:14:26 -05001426
1427 trans_time = ktime_to_ns(ktime_sub(ktime_get(),
1428 transaction->t_start_time));
1429
Theodore Ts'o30773842009-01-03 20:27:38 -05001430 commit_time = max_t(u64, commit_time,
1431 1000*journal->j_min_batch_time);
Josef Bacike07f7182008-11-26 01:14:26 -05001432 commit_time = min_t(u64, commit_time,
Theodore Ts'o30773842009-01-03 20:27:38 -05001433 1000*journal->j_max_batch_time);
Josef Bacike07f7182008-11-26 01:14:26 -05001434
1435 if (trans_time < commit_time) {
1436 ktime_t expires = ktime_add_ns(ktime_get(),
1437 commit_time);
1438 set_current_state(TASK_UNINTERRUPTIBLE);
1439 schedule_hrtimeout(&expires, HRTIMER_MODE_ABS);
1440 }
Dave Kleikamp470decc2006-10-11 01:20:57 -07001441 }
1442
Theodore Ts'o70585482009-03-25 23:35:46 -04001443 if (handle->h_sync)
1444 transaction->t_synchronous_commit = 1;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001445 current->journal_info = NULL;
Theodore Ts'oa51dca92010-08-02 08:43:25 -04001446 atomic_sub(handle->h_buffer_credits,
1447 &transaction->t_outstanding_credits);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001448
1449 /*
1450 * If the handle is marked SYNC, we need to set another commit
1451 * going! We also want to force a commit if the current
1452 * transaction is occupying too much of the log, or if the
1453 * transaction is too old now.
1454 */
1455 if (handle->h_sync ||
Theodore Ts'oa51dca92010-08-02 08:43:25 -04001456 (atomic_read(&transaction->t_outstanding_credits) >
1457 journal->j_max_transaction_buffers) ||
1458 time_after_eq(jiffies, transaction->t_expires)) {
Dave Kleikamp470decc2006-10-11 01:20:57 -07001459 /* Do this even for aborted journals: an abort still
1460 * completes the commit thread, it just doesn't write
1461 * anything to disk. */
Dave Kleikamp470decc2006-10-11 01:20:57 -07001462
Dave Kleikamp470decc2006-10-11 01:20:57 -07001463 jbd_debug(2, "transaction too old, requesting commit for "
1464 "handle %p\n", handle);
1465 /* This is non-blocking */
Theodore Ts'oc35a56a2010-05-16 05:00:00 -04001466 jbd2_log_start_commit(journal, transaction->t_tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001467
1468 /*
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001469 * Special case: JBD2_SYNC synchronous updates require us
Dave Kleikamp470decc2006-10-11 01:20:57 -07001470 * to wait for the commit to complete.
1471 */
1472 if (handle->h_sync && !(current->flags & PF_MEMALLOC))
Theodore Ts'oa51dca92010-08-02 08:43:25 -04001473 wait_for_commit = 1;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001474 }
1475
Theodore Ts'oa51dca92010-08-02 08:43:25 -04001476 /*
1477 * Once we drop t_updates, if it goes to zero the transaction
Lucas De Marchi25985ed2011-03-30 22:57:33 -03001478 * could start committing on us and eventually disappear. So
Theodore Ts'oa51dca92010-08-02 08:43:25 -04001479 * once we do this, we must not dereference transaction
1480 * pointer again.
1481 */
1482 tid = transaction->t_tid;
1483 if (atomic_dec_and_test(&transaction->t_updates)) {
1484 wake_up(&journal->j_wait_updates);
1485 if (journal->j_barrier_count)
1486 wake_up(&journal->j_wait_transaction_locked);
1487 }
1488
1489 if (wait_for_commit)
1490 err = jbd2_log_wait_commit(journal, tid);
1491
Ingo Molnar3295f0e2008-08-11 10:30:30 +02001492 lock_map_release(&handle->h_lockdep_map);
Mingming Cao7b751062008-01-28 23:58:27 -05001493
Mingming Caoaf1e76d2007-10-16 18:38:25 -04001494 jbd2_free_handle(handle);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001495 return err;
1496}
1497
Randy Dunlap5648ba52008-04-17 10:38:59 -04001498/**
1499 * int jbd2_journal_force_commit() - force any uncommitted transactions
Dave Kleikamp470decc2006-10-11 01:20:57 -07001500 * @journal: journal to force
1501 *
1502 * For synchronous operations: force any uncommitted transactions
1503 * to disk. May seem kludgy, but it reuses all the handle batching
1504 * code in a very simple manner.
1505 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001506int jbd2_journal_force_commit(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001507{
1508 handle_t *handle;
1509 int ret;
1510
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001511 handle = jbd2_journal_start(journal, 1);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001512 if (IS_ERR(handle)) {
1513 ret = PTR_ERR(handle);
1514 } else {
1515 handle->h_sync = 1;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001516 ret = jbd2_journal_stop(handle);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001517 }
1518 return ret;
1519}
1520
1521/*
1522 *
1523 * List management code snippets: various functions for manipulating the
1524 * transaction buffer lists.
1525 *
1526 */
1527
1528/*
1529 * Append a buffer to a transaction list, given the transaction's list head
1530 * pointer.
1531 *
1532 * j_list_lock is held.
1533 *
1534 * jbd_lock_bh_state(jh2bh(jh)) is held.
1535 */
1536
1537static inline void
1538__blist_add_buffer(struct journal_head **list, struct journal_head *jh)
1539{
1540 if (!*list) {
1541 jh->b_tnext = jh->b_tprev = jh;
1542 *list = jh;
1543 } else {
1544 /* Insert at the tail of the list to preserve order */
1545 struct journal_head *first = *list, *last = first->b_tprev;
1546 jh->b_tprev = last;
1547 jh->b_tnext = first;
1548 last->b_tnext = first->b_tprev = jh;
1549 }
1550}
1551
1552/*
1553 * Remove a buffer from a transaction list, given the transaction's list
1554 * head pointer.
1555 *
1556 * Called with j_list_lock held, and the journal may not be locked.
1557 *
1558 * jbd_lock_bh_state(jh2bh(jh)) is held.
1559 */
1560
1561static inline void
1562__blist_del_buffer(struct journal_head **list, struct journal_head *jh)
1563{
1564 if (*list == jh) {
1565 *list = jh->b_tnext;
1566 if (*list == jh)
1567 *list = NULL;
1568 }
1569 jh->b_tprev->b_tnext = jh->b_tnext;
1570 jh->b_tnext->b_tprev = jh->b_tprev;
1571}
1572
1573/*
1574 * Remove a buffer from the appropriate transaction list.
1575 *
1576 * Note that this function can *change* the value of
Jan Kara87c89c22008-07-11 19:27:31 -04001577 * bh->b_transaction->t_buffers, t_forget, t_iobuf_list, t_shadow_list,
1578 * t_log_list or t_reserved_list. If the caller is holding onto a copy of one
1579 * of these pointers, it could go bad. Generally the caller needs to re-read
1580 * the pointer from the transaction_t.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001581 *
Jan Kara5bebccf2012-03-13 22:25:06 -04001582 * Called under j_list_lock.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001583 */
Jan Kara5bebccf2012-03-13 22:25:06 -04001584static void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001585{
1586 struct journal_head **list = NULL;
1587 transaction_t *transaction;
1588 struct buffer_head *bh = jh2bh(jh);
1589
1590 J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh));
1591 transaction = jh->b_transaction;
1592 if (transaction)
1593 assert_spin_locked(&transaction->t_journal->j_list_lock);
1594
1595 J_ASSERT_JH(jh, jh->b_jlist < BJ_Types);
1596 if (jh->b_jlist != BJ_None)
Mingming Cao40191912008-01-28 23:58:27 -05001597 J_ASSERT_JH(jh, transaction != NULL);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001598
1599 switch (jh->b_jlist) {
1600 case BJ_None:
1601 return;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001602 case BJ_Metadata:
1603 transaction->t_nr_buffers--;
1604 J_ASSERT_JH(jh, transaction->t_nr_buffers >= 0);
1605 list = &transaction->t_buffers;
1606 break;
1607 case BJ_Forget:
1608 list = &transaction->t_forget;
1609 break;
1610 case BJ_IO:
1611 list = &transaction->t_iobuf_list;
1612 break;
1613 case BJ_Shadow:
1614 list = &transaction->t_shadow_list;
1615 break;
1616 case BJ_LogCtl:
1617 list = &transaction->t_log_list;
1618 break;
1619 case BJ_Reserved:
1620 list = &transaction->t_reserved_list;
1621 break;
Dave Kleikamp470decc2006-10-11 01:20:57 -07001622 }
1623
1624 __blist_del_buffer(list, jh);
1625 jh->b_jlist = BJ_None;
1626 if (test_clear_buffer_jbddirty(bh))
1627 mark_buffer_dirty(bh); /* Expose it to the VM */
1628}
1629
Jan Karade1b7942011-06-13 15:38:22 -04001630/*
1631 * Remove buffer from all transactions.
1632 *
1633 * Called with bh_state lock and j_list_lock
1634 *
1635 * jh and bh may be already freed when this function returns.
1636 */
1637static void __jbd2_journal_unfile_buffer(struct journal_head *jh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001638{
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001639 __jbd2_journal_temp_unlink_buffer(jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001640 jh->b_transaction = NULL;
Jan Karade1b7942011-06-13 15:38:22 -04001641 jbd2_journal_put_journal_head(jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001642}
1643
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001644void jbd2_journal_unfile_buffer(journal_t *journal, struct journal_head *jh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001645{
Jan Karade1b7942011-06-13 15:38:22 -04001646 struct buffer_head *bh = jh2bh(jh);
1647
1648 /* Get reference so that buffer cannot be freed before we unlock it */
1649 get_bh(bh);
1650 jbd_lock_bh_state(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001651 spin_lock(&journal->j_list_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001652 __jbd2_journal_unfile_buffer(jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001653 spin_unlock(&journal->j_list_lock);
Jan Karade1b7942011-06-13 15:38:22 -04001654 jbd_unlock_bh_state(bh);
1655 __brelse(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001656}
1657
1658/*
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001659 * Called from jbd2_journal_try_to_free_buffers().
Dave Kleikamp470decc2006-10-11 01:20:57 -07001660 *
1661 * Called under jbd_lock_bh_state(bh)
1662 */
1663static void
1664__journal_try_to_free_buffer(journal_t *journal, struct buffer_head *bh)
1665{
1666 struct journal_head *jh;
1667
1668 jh = bh2jh(bh);
1669
1670 if (buffer_locked(bh) || buffer_dirty(bh))
1671 goto out;
1672
Mingming Cao40191912008-01-28 23:58:27 -05001673 if (jh->b_next_transaction != NULL)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001674 goto out;
1675
1676 spin_lock(&journal->j_list_lock);
Jan Kara87c89c22008-07-11 19:27:31 -04001677 if (jh->b_cp_transaction != NULL && jh->b_transaction == NULL) {
Dave Kleikamp470decc2006-10-11 01:20:57 -07001678 /* written-back checkpointed metadata buffer */
Jan Karac254c9e2012-03-13 22:27:44 -04001679 JBUFFER_TRACE(jh, "remove from checkpoint list");
1680 __jbd2_journal_remove_checkpoint(jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001681 }
1682 spin_unlock(&journal->j_list_lock);
1683out:
1684 return;
1685}
1686
Dave Kleikamp470decc2006-10-11 01:20:57 -07001687/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001688 * int jbd2_journal_try_to_free_buffers() - try to free page buffers.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001689 * @journal: journal for operation
1690 * @page: to try and free
Mingming Cao530576b2008-07-13 21:06:39 -04001691 * @gfp_mask: we use the mask to detect how hard should we try to release
1692 * buffers. If __GFP_WAIT and __GFP_FS is set, we wait for commit code to
1693 * release the buffers.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001694 *
1695 *
1696 * For all the buffers on this page,
1697 * if they are fully written out ordered data, move them onto BUF_CLEAN
1698 * so try_to_free_buffers() can reap them.
1699 *
1700 * This function returns non-zero if we wish try_to_free_buffers()
1701 * to be called. We do this if the page is releasable by try_to_free_buffers().
1702 * We also do it if the page has locked or dirty buffers and the caller wants
1703 * us to perform sync or async writeout.
1704 *
1705 * This complicates JBD locking somewhat. We aren't protected by the
1706 * BKL here. We wish to remove the buffer from its committing or
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001707 * running transaction's ->t_datalist via __jbd2_journal_unfile_buffer.
Dave Kleikamp470decc2006-10-11 01:20:57 -07001708 *
1709 * This may *change* the value of transaction_t->t_datalist, so anyone
1710 * who looks at t_datalist needs to lock against this function.
1711 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001712 * Even worse, someone may be doing a jbd2_journal_dirty_data on this
1713 * buffer. So we need to lock against that. jbd2_journal_dirty_data()
Dave Kleikamp470decc2006-10-11 01:20:57 -07001714 * will come out of the lock with the buffer dirty, which makes it
1715 * ineligible for release here.
1716 *
1717 * Who else is affected by this? hmm... Really the only contender
1718 * is do_get_write_access() - it could be looking at the buffer while
1719 * journal_try_to_free_buffer() is changing its state. But that
1720 * cannot happen because we never reallocate freed data as metadata
1721 * while the data is part of a transaction. Yes?
Mingming Cao530576b2008-07-13 21:06:39 -04001722 *
1723 * Return 0 on failure, 1 on success
Dave Kleikamp470decc2006-10-11 01:20:57 -07001724 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001725int jbd2_journal_try_to_free_buffers(journal_t *journal,
Mingming Cao530576b2008-07-13 21:06:39 -04001726 struct page *page, gfp_t gfp_mask)
Dave Kleikamp470decc2006-10-11 01:20:57 -07001727{
1728 struct buffer_head *head;
1729 struct buffer_head *bh;
1730 int ret = 0;
1731
1732 J_ASSERT(PageLocked(page));
1733
1734 head = page_buffers(page);
1735 bh = head;
1736 do {
1737 struct journal_head *jh;
1738
1739 /*
1740 * We take our own ref against the journal_head here to avoid
1741 * having to add tons of locking around each instance of
Mingming Cao530576b2008-07-13 21:06:39 -04001742 * jbd2_journal_put_journal_head().
Dave Kleikamp470decc2006-10-11 01:20:57 -07001743 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001744 jh = jbd2_journal_grab_journal_head(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001745 if (!jh)
1746 continue;
1747
1748 jbd_lock_bh_state(bh);
1749 __journal_try_to_free_buffer(journal, bh);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001750 jbd2_journal_put_journal_head(jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001751 jbd_unlock_bh_state(bh);
1752 if (buffer_jbd(bh))
1753 goto busy;
1754 } while ((bh = bh->b_this_page) != head);
Mingming Cao530576b2008-07-13 21:06:39 -04001755
Dave Kleikamp470decc2006-10-11 01:20:57 -07001756 ret = try_to_free_buffers(page);
Mingming Cao530576b2008-07-13 21:06:39 -04001757
Dave Kleikamp470decc2006-10-11 01:20:57 -07001758busy:
1759 return ret;
1760}
1761
1762/*
1763 * This buffer is no longer needed. If it is on an older transaction's
1764 * checkpoint list we need to record it on this transaction's forget list
1765 * to pin this buffer (and hence its checkpointing transaction) down until
1766 * this transaction commits. If the buffer isn't on a checkpoint list, we
1767 * release it.
1768 * Returns non-zero if JBD no longer has an interest in the buffer.
1769 *
1770 * Called under j_list_lock.
1771 *
1772 * Called under jbd_lock_bh_state(bh).
1773 */
1774static int __dispose_buffer(struct journal_head *jh, transaction_t *transaction)
1775{
1776 int may_free = 1;
1777 struct buffer_head *bh = jh2bh(jh);
1778
Dave Kleikamp470decc2006-10-11 01:20:57 -07001779 if (jh->b_cp_transaction) {
1780 JBUFFER_TRACE(jh, "on running+cp transaction");
Jan Karade1b7942011-06-13 15:38:22 -04001781 __jbd2_journal_temp_unlink_buffer(jh);
Jan Karaf91d1d02009-07-13 16:16:20 -04001782 /*
1783 * We don't want to write the buffer anymore, clear the
1784 * bit so that we don't confuse checks in
1785 * __journal_file_buffer
1786 */
1787 clear_buffer_dirty(bh);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001788 __jbd2_journal_file_buffer(jh, transaction, BJ_Forget);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001789 may_free = 0;
1790 } else {
1791 JBUFFER_TRACE(jh, "on running transaction");
Jan Karade1b7942011-06-13 15:38:22 -04001792 __jbd2_journal_unfile_buffer(jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001793 }
1794 return may_free;
1795}
1796
1797/*
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001798 * jbd2_journal_invalidatepage
Dave Kleikamp470decc2006-10-11 01:20:57 -07001799 *
1800 * This code is tricky. It has a number of cases to deal with.
1801 *
1802 * There are two invariants which this code relies on:
1803 *
1804 * i_size must be updated on disk before we start calling invalidatepage on the
1805 * data.
1806 *
1807 * This is done in ext3 by defining an ext3_setattr method which
1808 * updates i_size before truncate gets going. By maintaining this
1809 * invariant, we can be sure that it is safe to throw away any buffers
1810 * attached to the current transaction: once the transaction commits,
1811 * we know that the data will not be needed.
1812 *
1813 * Note however that we can *not* throw away data belonging to the
1814 * previous, committing transaction!
1815 *
1816 * Any disk blocks which *are* part of the previous, committing
1817 * transaction (and which therefore cannot be discarded immediately) are
1818 * not going to be reused in the new running transaction
1819 *
1820 * The bitmap committed_data images guarantee this: any block which is
1821 * allocated in one transaction and removed in the next will be marked
1822 * as in-use in the committed_data bitmap, so cannot be reused until
1823 * the next transaction to delete the block commits. This means that
1824 * leaving committing buffers dirty is quite safe: the disk blocks
1825 * cannot be reallocated to a different file and so buffer aliasing is
1826 * not possible.
1827 *
1828 *
1829 * The above applies mainly to ordered data mode. In writeback mode we
1830 * don't make guarantees about the order in which data hits disk --- in
1831 * particular we don't guarantee that new dirty data is flushed before
1832 * transaction commit --- so it is always safe just to discard data
1833 * immediately in that mode. --sct
1834 */
1835
1836/*
1837 * The journal_unmap_buffer helper function returns zero if the buffer
1838 * concerned remains pinned as an anonymous buffer belonging to an older
1839 * transaction.
1840 *
1841 * We're outside-transaction here. Either or both of j_running_transaction
1842 * and j_committing_transaction may be NULL.
1843 */
1844static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh)
1845{
1846 transaction_t *transaction;
1847 struct journal_head *jh;
1848 int may_free = 1;
1849 int ret;
1850
1851 BUFFER_TRACE(bh, "entry");
1852
1853 /*
1854 * It is safe to proceed here without the j_list_lock because the
1855 * buffers cannot be stolen by try_to_free_buffers as long as we are
1856 * holding the page lock. --sct
1857 */
1858
1859 if (!buffer_jbd(bh))
1860 goto zap_buffer_unlocked;
1861
Jan Kara87c89c22008-07-11 19:27:31 -04001862 /* OK, we have data buffer in journaled mode */
Theodore Ts'oa931da62010-08-03 21:35:12 -04001863 write_lock(&journal->j_state_lock);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001864 jbd_lock_bh_state(bh);
1865 spin_lock(&journal->j_list_lock);
1866
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001867 jh = jbd2_journal_grab_journal_head(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001868 if (!jh)
1869 goto zap_buffer_no_jh;
1870
dingdinghuaba869022010-02-15 16:35:42 -05001871 /*
1872 * We cannot remove the buffer from checkpoint lists until the
1873 * transaction adding inode to orphan list (let's call it T)
1874 * is committed. Otherwise if the transaction changing the
1875 * buffer would be cleaned from the journal before T is
1876 * committed, a crash will cause that the correct contents of
1877 * the buffer will be lost. On the other hand we have to
1878 * clear the buffer dirty bit at latest at the moment when the
1879 * transaction marking the buffer as freed in the filesystem
1880 * structures is committed because from that moment on the
1881 * buffer can be reallocated and used by a different page.
1882 * Since the block hasn't been freed yet but the inode has
1883 * already been added to orphan list, it is safe for us to add
1884 * the buffer to BJ_Forget list of the newest transaction.
1885 */
Dave Kleikamp470decc2006-10-11 01:20:57 -07001886 transaction = jh->b_transaction;
1887 if (transaction == NULL) {
1888 /* First case: not on any transaction. If it
1889 * has no checkpoint link, then we can zap it:
1890 * it's a writeback-mode buffer so we don't care
1891 * if it hits disk safely. */
1892 if (!jh->b_cp_transaction) {
1893 JBUFFER_TRACE(jh, "not on any transaction: zap");
1894 goto zap_buffer;
1895 }
1896
1897 if (!buffer_dirty(bh)) {
1898 /* bdflush has written it. We can drop it now */
1899 goto zap_buffer;
1900 }
1901
1902 /* OK, it must be in the journal but still not
1903 * written fully to disk: it's metadata or
1904 * journaled data... */
1905
1906 if (journal->j_running_transaction) {
1907 /* ... and once the current transaction has
1908 * committed, the buffer won't be needed any
1909 * longer. */
1910 JBUFFER_TRACE(jh, "checkpointed: add to BJ_Forget");
1911 ret = __dispose_buffer(jh,
1912 journal->j_running_transaction);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001913 jbd2_journal_put_journal_head(jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001914 spin_unlock(&journal->j_list_lock);
1915 jbd_unlock_bh_state(bh);
Theodore Ts'oa931da62010-08-03 21:35:12 -04001916 write_unlock(&journal->j_state_lock);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001917 return ret;
1918 } else {
1919 /* There is no currently-running transaction. So the
1920 * orphan record which we wrote for this file must have
1921 * passed into commit. We must attach this buffer to
1922 * the committing transaction, if it exists. */
1923 if (journal->j_committing_transaction) {
1924 JBUFFER_TRACE(jh, "give to committing trans");
1925 ret = __dispose_buffer(jh,
1926 journal->j_committing_transaction);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001927 jbd2_journal_put_journal_head(jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001928 spin_unlock(&journal->j_list_lock);
1929 jbd_unlock_bh_state(bh);
Theodore Ts'oa931da62010-08-03 21:35:12 -04001930 write_unlock(&journal->j_state_lock);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001931 return ret;
1932 } else {
1933 /* The orphan record's transaction has
1934 * committed. We can cleanse this buffer */
1935 clear_buffer_jbddirty(bh);
1936 goto zap_buffer;
1937 }
1938 }
1939 } else if (transaction == journal->j_committing_transaction) {
Eric Sandeen9b579882006-10-28 10:38:28 -07001940 JBUFFER_TRACE(jh, "on committing transaction");
Dave Kleikamp470decc2006-10-11 01:20:57 -07001941 /*
dingdinghuaba869022010-02-15 16:35:42 -05001942 * The buffer is committing, we simply cannot touch
1943 * it. So we just set j_next_transaction to the
1944 * running transaction (if there is one) and mark
1945 * buffer as freed so that commit code knows it should
1946 * clear dirty bits when it is done with the buffer.
1947 */
Dave Kleikamp470decc2006-10-11 01:20:57 -07001948 set_buffer_freed(bh);
dingdinghuaba869022010-02-15 16:35:42 -05001949 if (journal->j_running_transaction && buffer_jbddirty(bh))
1950 jh->b_next_transaction = journal->j_running_transaction;
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001951 jbd2_journal_put_journal_head(jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001952 spin_unlock(&journal->j_list_lock);
1953 jbd_unlock_bh_state(bh);
Theodore Ts'oa931da62010-08-03 21:35:12 -04001954 write_unlock(&journal->j_state_lock);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001955 return 0;
1956 } else {
1957 /* Good, the buffer belongs to the running transaction.
1958 * We are writing our own transaction's data, not any
1959 * previous one's, so it is safe to throw it away
1960 * (remember that we expect the filesystem to have set
1961 * i_size already for this truncate so recovery will not
1962 * expose the disk blocks we are discarding here.) */
1963 J_ASSERT_JH(jh, transaction == journal->j_running_transaction);
Eric Sandeen9b579882006-10-28 10:38:28 -07001964 JBUFFER_TRACE(jh, "on running transaction");
Dave Kleikamp470decc2006-10-11 01:20:57 -07001965 may_free = __dispose_buffer(jh, transaction);
1966 }
1967
1968zap_buffer:
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001969 jbd2_journal_put_journal_head(jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001970zap_buffer_no_jh:
1971 spin_unlock(&journal->j_list_lock);
1972 jbd_unlock_bh_state(bh);
Theodore Ts'oa931da62010-08-03 21:35:12 -04001973 write_unlock(&journal->j_state_lock);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001974zap_buffer_unlocked:
1975 clear_buffer_dirty(bh);
1976 J_ASSERT_BH(bh, !buffer_jbddirty(bh));
1977 clear_buffer_mapped(bh);
1978 clear_buffer_req(bh);
1979 clear_buffer_new(bh);
Eric Sandeen15291162012-02-20 17:53:01 -05001980 clear_buffer_delay(bh);
1981 clear_buffer_unwritten(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07001982 bh->b_bdev = NULL;
1983 return may_free;
1984}
1985
1986/**
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001987 * void jbd2_journal_invalidatepage()
Dave Kleikamp470decc2006-10-11 01:20:57 -07001988 * @journal: journal to use for flush...
1989 * @page: page to flush
1990 * @offset: length of page to invalidate.
1991 *
1992 * Reap page buffers containing data after offset in page.
1993 *
1994 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07001995void jbd2_journal_invalidatepage(journal_t *journal,
Dave Kleikamp470decc2006-10-11 01:20:57 -07001996 struct page *page,
1997 unsigned long offset)
1998{
1999 struct buffer_head *head, *bh, *next;
2000 unsigned int curr_off = 0;
2001 int may_free = 1;
2002
2003 if (!PageLocked(page))
2004 BUG();
2005 if (!page_has_buffers(page))
2006 return;
2007
2008 /* We will potentially be playing with lists other than just the
2009 * data lists (especially for journaled data mode), so be
2010 * cautious in our locking. */
2011
2012 head = bh = page_buffers(page);
2013 do {
2014 unsigned int next_off = curr_off + bh->b_size;
2015 next = bh->b_this_page;
2016
2017 if (offset <= curr_off) {
2018 /* This block is wholly outside the truncation point */
2019 lock_buffer(bh);
2020 may_free &= journal_unmap_buffer(journal, bh);
2021 unlock_buffer(bh);
2022 }
2023 curr_off = next_off;
2024 bh = next;
2025
2026 } while (bh != head);
2027
2028 if (!offset) {
2029 if (may_free && try_to_free_buffers(page))
2030 J_ASSERT(!page_has_buffers(page));
2031 }
2032}
2033
2034/*
2035 * File a buffer on the given transaction list.
2036 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002037void __jbd2_journal_file_buffer(struct journal_head *jh,
Dave Kleikamp470decc2006-10-11 01:20:57 -07002038 transaction_t *transaction, int jlist)
2039{
2040 struct journal_head **list = NULL;
2041 int was_dirty = 0;
2042 struct buffer_head *bh = jh2bh(jh);
2043
2044 J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh));
2045 assert_spin_locked(&transaction->t_journal->j_list_lock);
2046
2047 J_ASSERT_JH(jh, jh->b_jlist < BJ_Types);
2048 J_ASSERT_JH(jh, jh->b_transaction == transaction ||
Mingming Cao40191912008-01-28 23:58:27 -05002049 jh->b_transaction == NULL);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002050
2051 if (jh->b_transaction && jh->b_jlist == jlist)
2052 return;
2053
Dave Kleikamp470decc2006-10-11 01:20:57 -07002054 if (jlist == BJ_Metadata || jlist == BJ_Reserved ||
2055 jlist == BJ_Shadow || jlist == BJ_Forget) {
Jan Karaf91d1d02009-07-13 16:16:20 -04002056 /*
2057 * For metadata buffers, we track dirty bit in buffer_jbddirty
2058 * instead of buffer_dirty. We should not see a dirty bit set
2059 * here because we clear it in do_get_write_access but e.g.
2060 * tune2fs can modify the sb and set the dirty bit at any time
2061 * so we try to gracefully handle that.
2062 */
2063 if (buffer_dirty(bh))
2064 warn_dirty_buffer(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002065 if (test_clear_buffer_dirty(bh) ||
2066 test_clear_buffer_jbddirty(bh))
2067 was_dirty = 1;
2068 }
2069
2070 if (jh->b_transaction)
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002071 __jbd2_journal_temp_unlink_buffer(jh);
Jan Karade1b7942011-06-13 15:38:22 -04002072 else
2073 jbd2_journal_grab_journal_head(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002074 jh->b_transaction = transaction;
2075
2076 switch (jlist) {
2077 case BJ_None:
2078 J_ASSERT_JH(jh, !jh->b_committed_data);
2079 J_ASSERT_JH(jh, !jh->b_frozen_data);
2080 return;
Dave Kleikamp470decc2006-10-11 01:20:57 -07002081 case BJ_Metadata:
2082 transaction->t_nr_buffers++;
2083 list = &transaction->t_buffers;
2084 break;
2085 case BJ_Forget:
2086 list = &transaction->t_forget;
2087 break;
2088 case BJ_IO:
2089 list = &transaction->t_iobuf_list;
2090 break;
2091 case BJ_Shadow:
2092 list = &transaction->t_shadow_list;
2093 break;
2094 case BJ_LogCtl:
2095 list = &transaction->t_log_list;
2096 break;
2097 case BJ_Reserved:
2098 list = &transaction->t_reserved_list;
2099 break;
Dave Kleikamp470decc2006-10-11 01:20:57 -07002100 }
2101
2102 __blist_add_buffer(list, jh);
2103 jh->b_jlist = jlist;
2104
2105 if (was_dirty)
2106 set_buffer_jbddirty(bh);
2107}
2108
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002109void jbd2_journal_file_buffer(struct journal_head *jh,
Dave Kleikamp470decc2006-10-11 01:20:57 -07002110 transaction_t *transaction, int jlist)
2111{
2112 jbd_lock_bh_state(jh2bh(jh));
2113 spin_lock(&transaction->t_journal->j_list_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002114 __jbd2_journal_file_buffer(jh, transaction, jlist);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002115 spin_unlock(&transaction->t_journal->j_list_lock);
2116 jbd_unlock_bh_state(jh2bh(jh));
2117}
2118
2119/*
2120 * Remove a buffer from its current buffer list in preparation for
2121 * dropping it from its current transaction entirely. If the buffer has
2122 * already started to be used by a subsequent transaction, refile the
2123 * buffer on that transaction's metadata list.
2124 *
Jan Karade1b7942011-06-13 15:38:22 -04002125 * Called under j_list_lock
Dave Kleikamp470decc2006-10-11 01:20:57 -07002126 * Called under jbd_lock_bh_state(jh2bh(jh))
Jan Karade1b7942011-06-13 15:38:22 -04002127 *
2128 * jh and bh may be already free when this function returns
Dave Kleikamp470decc2006-10-11 01:20:57 -07002129 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002130void __jbd2_journal_refile_buffer(struct journal_head *jh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07002131{
dingdinghuaba869022010-02-15 16:35:42 -05002132 int was_dirty, jlist;
Dave Kleikamp470decc2006-10-11 01:20:57 -07002133 struct buffer_head *bh = jh2bh(jh);
2134
2135 J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh));
2136 if (jh->b_transaction)
2137 assert_spin_locked(&jh->b_transaction->t_journal->j_list_lock);
2138
2139 /* If the buffer is now unused, just drop it. */
2140 if (jh->b_next_transaction == NULL) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002141 __jbd2_journal_unfile_buffer(jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002142 return;
2143 }
2144
2145 /*
2146 * It has been modified by a later transaction: add it to the new
2147 * transaction's metadata list.
2148 */
2149
2150 was_dirty = test_clear_buffer_jbddirty(bh);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002151 __jbd2_journal_temp_unlink_buffer(jh);
Jan Karade1b7942011-06-13 15:38:22 -04002152 /*
2153 * We set b_transaction here because b_next_transaction will inherit
2154 * our jh reference and thus __jbd2_journal_file_buffer() must not
2155 * take a new one.
2156 */
Dave Kleikamp470decc2006-10-11 01:20:57 -07002157 jh->b_transaction = jh->b_next_transaction;
2158 jh->b_next_transaction = NULL;
dingdinghuaba869022010-02-15 16:35:42 -05002159 if (buffer_freed(bh))
2160 jlist = BJ_Forget;
2161 else if (jh->b_modified)
2162 jlist = BJ_Metadata;
2163 else
2164 jlist = BJ_Reserved;
2165 __jbd2_journal_file_buffer(jh, jh->b_transaction, jlist);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002166 J_ASSERT_JH(jh, jh->b_transaction->t_state == T_RUNNING);
2167
2168 if (was_dirty)
2169 set_buffer_jbddirty(bh);
2170}
2171
2172/*
Jan Karade1b7942011-06-13 15:38:22 -04002173 * __jbd2_journal_refile_buffer() with necessary locking added. We take our
2174 * bh reference so that we can safely unlock bh.
Dave Kleikamp470decc2006-10-11 01:20:57 -07002175 *
Jan Karade1b7942011-06-13 15:38:22 -04002176 * The jh and bh may be freed by this call.
Dave Kleikamp470decc2006-10-11 01:20:57 -07002177 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002178void jbd2_journal_refile_buffer(journal_t *journal, struct journal_head *jh)
Dave Kleikamp470decc2006-10-11 01:20:57 -07002179{
2180 struct buffer_head *bh = jh2bh(jh);
2181
Jan Karade1b7942011-06-13 15:38:22 -04002182 /* Get reference so that buffer cannot be freed before we unlock it */
2183 get_bh(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002184 jbd_lock_bh_state(bh);
2185 spin_lock(&journal->j_list_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -07002186 __jbd2_journal_refile_buffer(jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002187 jbd_unlock_bh_state(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -07002188 spin_unlock(&journal->j_list_lock);
2189 __brelse(bh);
2190}
Jan Karac851ed52008-07-11 19:27:31 -04002191
2192/*
2193 * File inode in the inode list of the handle's transaction
2194 */
2195int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *jinode)
2196{
2197 transaction_t *transaction = handle->h_transaction;
2198 journal_t *journal = transaction->t_journal;
2199
2200 if (is_handle_aborted(handle))
2201 return -EIO;
2202
2203 jbd_debug(4, "Adding inode %lu, tid:%d\n", jinode->i_vfs_inode->i_ino,
2204 transaction->t_tid);
2205
2206 /*
2207 * First check whether inode isn't already on the transaction's
2208 * lists without taking the lock. Note that this check is safe
2209 * without the lock as we cannot race with somebody removing inode
2210 * from the transaction. The reason is that we remove inode from the
2211 * transaction only in journal_release_jbd_inode() and when we commit
2212 * the transaction. We are guarded from the first case by holding
2213 * a reference to the inode. We are safe against the second case
2214 * because if jinode->i_transaction == transaction, commit code
2215 * cannot touch the transaction because we hold reference to it,
2216 * and if jinode->i_next_transaction == transaction, commit code
2217 * will only file the inode where we want it.
2218 */
2219 if (jinode->i_transaction == transaction ||
2220 jinode->i_next_transaction == transaction)
2221 return 0;
2222
2223 spin_lock(&journal->j_list_lock);
2224
2225 if (jinode->i_transaction == transaction ||
2226 jinode->i_next_transaction == transaction)
2227 goto done;
2228
Jan Kara81be12c2011-05-24 11:52:40 -04002229 /*
2230 * We only ever set this variable to 1 so the test is safe. Since
2231 * t_need_data_flush is likely to be set, we do the test to save some
2232 * cacheline bouncing
2233 */
2234 if (!transaction->t_need_data_flush)
2235 transaction->t_need_data_flush = 1;
Jan Karac851ed52008-07-11 19:27:31 -04002236 /* On some different transaction's list - should be
2237 * the committing one */
2238 if (jinode->i_transaction) {
2239 J_ASSERT(jinode->i_next_transaction == NULL);
2240 J_ASSERT(jinode->i_transaction ==
2241 journal->j_committing_transaction);
2242 jinode->i_next_transaction = transaction;
2243 goto done;
2244 }
2245 /* Not on any transaction list... */
2246 J_ASSERT(!jinode->i_next_transaction);
2247 jinode->i_transaction = transaction;
2248 list_add(&jinode->i_list, &transaction->t_inode_list);
2249done:
2250 spin_unlock(&journal->j_list_lock);
2251
2252 return 0;
2253}
2254
2255/*
Jan Kara7f5aa212009-02-10 11:15:34 -05002256 * File truncate and transaction commit interact with each other in a
2257 * non-trivial way. If a transaction writing data block A is
2258 * committing, we cannot discard the data by truncate until we have
2259 * written them. Otherwise if we crashed after the transaction with
2260 * write has committed but before the transaction with truncate has
2261 * committed, we could see stale data in block A. This function is a
2262 * helper to solve this problem. It starts writeout of the truncated
2263 * part in case it is in the committing transaction.
2264 *
2265 * Filesystem code must call this function when inode is journaled in
2266 * ordered mode before truncation happens and after the inode has been
2267 * placed on orphan list with the new inode size. The second condition
2268 * avoids the race that someone writes new data and we start
2269 * committing the transaction after this function has been called but
2270 * before a transaction for truncate is started (and furthermore it
2271 * allows us to optimize the case where the addition to orphan list
2272 * happens in the same transaction as write --- we don't have to write
2273 * any data in such case).
Jan Karac851ed52008-07-11 19:27:31 -04002274 */
Jan Kara7f5aa212009-02-10 11:15:34 -05002275int jbd2_journal_begin_ordered_truncate(journal_t *journal,
2276 struct jbd2_inode *jinode,
Jan Karac851ed52008-07-11 19:27:31 -04002277 loff_t new_size)
2278{
Jan Kara7f5aa212009-02-10 11:15:34 -05002279 transaction_t *inode_trans, *commit_trans;
Jan Karac851ed52008-07-11 19:27:31 -04002280 int ret = 0;
2281
Jan Kara7f5aa212009-02-10 11:15:34 -05002282 /* This is a quick check to avoid locking if not necessary */
2283 if (!jinode->i_transaction)
Jan Karac851ed52008-07-11 19:27:31 -04002284 goto out;
Jan Kara7f5aa212009-02-10 11:15:34 -05002285 /* Locks are here just to force reading of recent values, it is
2286 * enough that the transaction was not committing before we started
2287 * a transaction adding the inode to orphan list */
Theodore Ts'oa931da62010-08-03 21:35:12 -04002288 read_lock(&journal->j_state_lock);
Jan Karac851ed52008-07-11 19:27:31 -04002289 commit_trans = journal->j_committing_transaction;
Theodore Ts'oa931da62010-08-03 21:35:12 -04002290 read_unlock(&journal->j_state_lock);
Jan Kara7f5aa212009-02-10 11:15:34 -05002291 spin_lock(&journal->j_list_lock);
2292 inode_trans = jinode->i_transaction;
2293 spin_unlock(&journal->j_list_lock);
2294 if (inode_trans == commit_trans) {
2295 ret = filemap_fdatawrite_range(jinode->i_vfs_inode->i_mapping,
Jan Karac851ed52008-07-11 19:27:31 -04002296 new_size, LLONG_MAX);
2297 if (ret)
2298 jbd2_journal_abort(journal, ret);
2299 }
2300out:
2301 return ret;
2302}