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Commit | Line | Data |
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470decc6 | 1 | /* |
58862699 | 2 | * linux/fs/jbd2/transaction.c |
470decc6 DK |
3 | * |
4 | * Written by Stephen C. Tweedie <sct@redhat.com>, 1998 | |
5 | * | |
6 | * Copyright 1998 Red Hat corp --- All Rights Reserved | |
7 | * | |
8 | * This file is part of the Linux kernel and is made available under | |
9 | * the terms of the GNU General Public License, version 2, or at your | |
10 | * option, any later version, incorporated herein by reference. | |
11 | * | |
12 | * Generic filesystem transaction handling code; part of the ext2fs | |
13 | * journaling system. | |
14 | * | |
15 | * This file manages transactions (compound commits managed by the | |
16 | * journaling code) and handles (individual atomic operations by the | |
17 | * filesystem). | |
18 | */ | |
19 | ||
20 | #include <linux/time.h> | |
21 | #include <linux/fs.h> | |
f7f4bccb | 22 | #include <linux/jbd2.h> |
470decc6 DK |
23 | #include <linux/errno.h> |
24 | #include <linux/slab.h> | |
25 | #include <linux/timer.h> | |
470decc6 DK |
26 | #include <linux/mm.h> |
27 | #include <linux/highmem.h> | |
e07f7183 | 28 | #include <linux/hrtimer.h> |
47def826 | 29 | #include <linux/backing-dev.h> |
44705754 | 30 | #include <linux/bug.h> |
47def826 | 31 | #include <linux/module.h> |
470decc6 | 32 | |
343d9c28 TT |
33 | #include <trace/events/jbd2.h> |
34 | ||
7ddae860 | 35 | static void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh); |
de1b7941 | 36 | static void __jbd2_journal_unfile_buffer(struct journal_head *jh); |
7ddae860 | 37 | |
0c2022ec YY |
38 | static struct kmem_cache *transaction_cache; |
39 | int __init jbd2_journal_init_transaction_cache(void) | |
40 | { | |
41 | J_ASSERT(!transaction_cache); | |
42 | transaction_cache = kmem_cache_create("jbd2_transaction_s", | |
43 | sizeof(transaction_t), | |
44 | 0, | |
45 | SLAB_HWCACHE_ALIGN|SLAB_TEMPORARY, | |
46 | NULL); | |
47 | if (transaction_cache) | |
48 | return 0; | |
49 | return -ENOMEM; | |
50 | } | |
51 | ||
52 | void jbd2_journal_destroy_transaction_cache(void) | |
53 | { | |
54 | if (transaction_cache) { | |
55 | kmem_cache_destroy(transaction_cache); | |
56 | transaction_cache = NULL; | |
57 | } | |
58 | } | |
59 | ||
60 | void jbd2_journal_free_transaction(transaction_t *transaction) | |
61 | { | |
62 | if (unlikely(ZERO_OR_NULL_PTR(transaction))) | |
63 | return; | |
64 | kmem_cache_free(transaction_cache, transaction); | |
65 | } | |
66 | ||
470decc6 | 67 | /* |
f7f4bccb | 68 | * jbd2_get_transaction: obtain a new transaction_t object. |
470decc6 DK |
69 | * |
70 | * Simply allocate and initialise a new transaction. Create it in | |
71 | * RUNNING state and add it to the current journal (which should not | |
72 | * have an existing running transaction: we only make a new transaction | |
73 | * once we have started to commit the old one). | |
74 | * | |
75 | * Preconditions: | |
76 | * The journal MUST be locked. We don't perform atomic mallocs on the | |
77 | * new transaction and we can't block without protecting against other | |
78 | * processes trying to touch the journal while it is in transition. | |
79 | * | |
470decc6 DK |
80 | */ |
81 | ||
82 | static transaction_t * | |
f7f4bccb | 83 | jbd2_get_transaction(journal_t *journal, transaction_t *transaction) |
470decc6 DK |
84 | { |
85 | transaction->t_journal = journal; | |
86 | transaction->t_state = T_RUNNING; | |
e07f7183 | 87 | transaction->t_start_time = ktime_get(); |
470decc6 DK |
88 | transaction->t_tid = journal->j_transaction_sequence++; |
89 | transaction->t_expires = jiffies + journal->j_commit_interval; | |
90 | spin_lock_init(&transaction->t_handle_lock); | |
a51dca9c | 91 | atomic_set(&transaction->t_updates, 0); |
8f7d89f3 JK |
92 | atomic_set(&transaction->t_outstanding_credits, |
93 | atomic_read(&journal->j_reserved_credits)); | |
8dd42046 | 94 | atomic_set(&transaction->t_handle_count, 0); |
c851ed54 | 95 | INIT_LIST_HEAD(&transaction->t_inode_list); |
3e624fc7 | 96 | INIT_LIST_HEAD(&transaction->t_private_list); |
470decc6 DK |
97 | |
98 | /* Set up the commit timer for the new transaction. */ | |
b1f485f2 | 99 | journal->j_commit_timer.expires = round_jiffies_up(transaction->t_expires); |
470decc6 DK |
100 | add_timer(&journal->j_commit_timer); |
101 | ||
102 | J_ASSERT(journal->j_running_transaction == NULL); | |
103 | journal->j_running_transaction = transaction; | |
8e85fb3f JL |
104 | transaction->t_max_wait = 0; |
105 | transaction->t_start = jiffies; | |
9fff24aa | 106 | transaction->t_requested = 0; |
470decc6 DK |
107 | |
108 | return transaction; | |
109 | } | |
110 | ||
111 | /* | |
112 | * Handle management. | |
113 | * | |
114 | * A handle_t is an object which represents a single atomic update to a | |
115 | * filesystem, and which tracks all of the modifications which form part | |
116 | * of that one update. | |
117 | */ | |
118 | ||
6d0bf005 | 119 | /* |
28e35e42 | 120 | * Update transaction's maximum wait time, if debugging is enabled. |
6d0bf005 TT |
121 | * |
122 | * In order for t_max_wait to be reliable, it must be protected by a | |
123 | * lock. But doing so will mean that start_this_handle() can not be | |
124 | * run in parallel on SMP systems, which limits our scalability. So | |
125 | * unless debugging is enabled, we no longer update t_max_wait, which | |
126 | * means that maximum wait time reported by the jbd2_run_stats | |
127 | * tracepoint will always be zero. | |
128 | */ | |
28e35e42 TM |
129 | static inline void update_t_max_wait(transaction_t *transaction, |
130 | unsigned long ts) | |
6d0bf005 TT |
131 | { |
132 | #ifdef CONFIG_JBD2_DEBUG | |
6d0bf005 TT |
133 | if (jbd2_journal_enable_debug && |
134 | time_after(transaction->t_start, ts)) { | |
135 | ts = jbd2_time_diff(ts, transaction->t_start); | |
136 | spin_lock(&transaction->t_handle_lock); | |
137 | if (ts > transaction->t_max_wait) | |
138 | transaction->t_max_wait = ts; | |
139 | spin_unlock(&transaction->t_handle_lock); | |
140 | } | |
141 | #endif | |
142 | } | |
143 | ||
8f7d89f3 JK |
144 | /* |
145 | * Wait until running transaction passes T_LOCKED state. Also starts the commit | |
146 | * if needed. The function expects running transaction to exist and releases | |
147 | * j_state_lock. | |
148 | */ | |
149 | static void wait_transaction_locked(journal_t *journal) | |
150 | __releases(journal->j_state_lock) | |
151 | { | |
152 | DEFINE_WAIT(wait); | |
153 | int need_to_start; | |
154 | tid_t tid = journal->j_running_transaction->t_tid; | |
155 | ||
156 | prepare_to_wait(&journal->j_wait_transaction_locked, &wait, | |
157 | TASK_UNINTERRUPTIBLE); | |
158 | need_to_start = !tid_geq(journal->j_commit_request, tid); | |
159 | read_unlock(&journal->j_state_lock); | |
160 | if (need_to_start) | |
161 | jbd2_log_start_commit(journal, tid); | |
162 | schedule(); | |
163 | finish_wait(&journal->j_wait_transaction_locked, &wait); | |
164 | } | |
165 | ||
166 | static void sub_reserved_credits(journal_t *journal, int blocks) | |
167 | { | |
168 | atomic_sub(blocks, &journal->j_reserved_credits); | |
169 | wake_up(&journal->j_wait_reserved); | |
170 | } | |
171 | ||
172 | /* | |
173 | * Wait until we can add credits for handle to the running transaction. Called | |
174 | * with j_state_lock held for reading. Returns 0 if handle joined the running | |
175 | * transaction. Returns 1 if we had to wait, j_state_lock is dropped, and | |
176 | * caller must retry. | |
177 | */ | |
178 | static int add_transaction_credits(journal_t *journal, int blocks, | |
179 | int rsv_blocks) | |
180 | { | |
181 | transaction_t *t = journal->j_running_transaction; | |
182 | int needed; | |
183 | int total = blocks + rsv_blocks; | |
184 | ||
185 | /* | |
186 | * If the current transaction is locked down for commit, wait | |
187 | * for the lock to be released. | |
188 | */ | |
189 | if (t->t_state == T_LOCKED) { | |
190 | wait_transaction_locked(journal); | |
191 | return 1; | |
192 | } | |
193 | ||
194 | /* | |
195 | * If there is not enough space left in the log to write all | |
196 | * potential buffers requested by this operation, we need to | |
197 | * stall pending a log checkpoint to free some more log space. | |
198 | */ | |
199 | needed = atomic_add_return(total, &t->t_outstanding_credits); | |
200 | if (needed > journal->j_max_transaction_buffers) { | |
201 | /* | |
202 | * If the current transaction is already too large, | |
203 | * then start to commit it: we can then go back and | |
204 | * attach this handle to a new transaction. | |
205 | */ | |
206 | atomic_sub(total, &t->t_outstanding_credits); | |
207 | wait_transaction_locked(journal); | |
208 | return 1; | |
209 | } | |
210 | ||
211 | /* | |
212 | * The commit code assumes that it can get enough log space | |
213 | * without forcing a checkpoint. This is *critical* for | |
214 | * correctness: a checkpoint of a buffer which is also | |
215 | * associated with a committing transaction creates a deadlock, | |
216 | * so commit simply cannot force through checkpoints. | |
217 | * | |
218 | * We must therefore ensure the necessary space in the journal | |
219 | * *before* starting to dirty potentially checkpointed buffers | |
220 | * in the new transaction. | |
221 | */ | |
222 | if (jbd2_log_space_left(journal) < jbd2_space_needed(journal)) { | |
223 | atomic_sub(total, &t->t_outstanding_credits); | |
224 | read_unlock(&journal->j_state_lock); | |
225 | write_lock(&journal->j_state_lock); | |
226 | if (jbd2_log_space_left(journal) < jbd2_space_needed(journal)) | |
227 | __jbd2_log_wait_for_space(journal); | |
228 | write_unlock(&journal->j_state_lock); | |
229 | return 1; | |
230 | } | |
231 | ||
232 | /* No reservation? We are done... */ | |
233 | if (!rsv_blocks) | |
234 | return 0; | |
235 | ||
236 | needed = atomic_add_return(rsv_blocks, &journal->j_reserved_credits); | |
237 | /* We allow at most half of a transaction to be reserved */ | |
238 | if (needed > journal->j_max_transaction_buffers / 2) { | |
239 | sub_reserved_credits(journal, rsv_blocks); | |
240 | atomic_sub(total, &t->t_outstanding_credits); | |
241 | read_unlock(&journal->j_state_lock); | |
242 | wait_event(journal->j_wait_reserved, | |
243 | atomic_read(&journal->j_reserved_credits) + rsv_blocks | |
244 | <= journal->j_max_transaction_buffers / 2); | |
245 | return 1; | |
246 | } | |
247 | return 0; | |
248 | } | |
249 | ||
470decc6 DK |
250 | /* |
251 | * start_this_handle: Given a handle, deal with any locking or stalling | |
252 | * needed to make sure that there is enough journal space for the handle | |
253 | * to begin. Attach the handle to a transaction and set up the | |
254 | * transaction's buffer credits. | |
255 | */ | |
256 | ||
47def826 | 257 | static int start_this_handle(journal_t *journal, handle_t *handle, |
d2159fb7 | 258 | gfp_t gfp_mask) |
470decc6 | 259 | { |
e4471831 | 260 | transaction_t *transaction, *new_transaction = NULL; |
8f7d89f3 JK |
261 | int blocks = handle->h_buffer_credits; |
262 | int rsv_blocks = 0; | |
28e35e42 | 263 | unsigned long ts = jiffies; |
470decc6 | 264 | |
8f7d89f3 JK |
265 | /* |
266 | * 1/2 of transaction can be reserved so we can practically handle | |
267 | * only 1/2 of maximum transaction size per operation | |
268 | */ | |
269 | if (WARN_ON(blocks > journal->j_max_transaction_buffers / 2)) { | |
f2a44523 | 270 | printk(KERN_ERR "JBD2: %s wants too many credits (%d > %d)\n", |
8f7d89f3 JK |
271 | current->comm, blocks, |
272 | journal->j_max_transaction_buffers / 2); | |
47def826 | 273 | return -ENOSPC; |
470decc6 DK |
274 | } |
275 | ||
8f7d89f3 JK |
276 | if (handle->h_rsv_handle) |
277 | rsv_blocks = handle->h_rsv_handle->h_buffer_credits; | |
278 | ||
470decc6 DK |
279 | alloc_transaction: |
280 | if (!journal->j_running_transaction) { | |
b2f4edb3 WG |
281 | new_transaction = kmem_cache_zalloc(transaction_cache, |
282 | gfp_mask); | |
470decc6 | 283 | if (!new_transaction) { |
47def826 TT |
284 | /* |
285 | * If __GFP_FS is not present, then we may be | |
286 | * being called from inside the fs writeback | |
287 | * layer, so we MUST NOT fail. Since | |
288 | * __GFP_NOFAIL is going away, we will arrange | |
289 | * to retry the allocation ourselves. | |
290 | */ | |
291 | if ((gfp_mask & __GFP_FS) == 0) { | |
292 | congestion_wait(BLK_RW_ASYNC, HZ/50); | |
293 | goto alloc_transaction; | |
294 | } | |
295 | return -ENOMEM; | |
470decc6 | 296 | } |
470decc6 DK |
297 | } |
298 | ||
299 | jbd_debug(3, "New handle %p going live.\n", handle); | |
300 | ||
470decc6 DK |
301 | /* |
302 | * We need to hold j_state_lock until t_updates has been incremented, | |
303 | * for proper journal barrier handling | |
304 | */ | |
a931da6a TT |
305 | repeat: |
306 | read_lock(&journal->j_state_lock); | |
5c2178e7 | 307 | BUG_ON(journal->j_flags & JBD2_UNMOUNT); |
470decc6 | 308 | if (is_journal_aborted(journal) || |
f7f4bccb | 309 | (journal->j_errno != 0 && !(journal->j_flags & JBD2_ACK_ERR))) { |
a931da6a | 310 | read_unlock(&journal->j_state_lock); |
0c2022ec | 311 | jbd2_journal_free_transaction(new_transaction); |
47def826 | 312 | return -EROFS; |
470decc6 DK |
313 | } |
314 | ||
8f7d89f3 JK |
315 | /* |
316 | * Wait on the journal's transaction barrier if necessary. Specifically | |
317 | * we allow reserved handles to proceed because otherwise commit could | |
318 | * deadlock on page writeback not being able to complete. | |
319 | */ | |
320 | if (!handle->h_reserved && journal->j_barrier_count) { | |
a931da6a | 321 | read_unlock(&journal->j_state_lock); |
470decc6 DK |
322 | wait_event(journal->j_wait_transaction_locked, |
323 | journal->j_barrier_count == 0); | |
324 | goto repeat; | |
325 | } | |
326 | ||
327 | if (!journal->j_running_transaction) { | |
a931da6a TT |
328 | read_unlock(&journal->j_state_lock); |
329 | if (!new_transaction) | |
470decc6 | 330 | goto alloc_transaction; |
a931da6a | 331 | write_lock(&journal->j_state_lock); |
d7961c7f | 332 | if (!journal->j_running_transaction && |
8f7d89f3 | 333 | (handle->h_reserved || !journal->j_barrier_count)) { |
a931da6a TT |
334 | jbd2_get_transaction(journal, new_transaction); |
335 | new_transaction = NULL; | |
470decc6 | 336 | } |
a931da6a TT |
337 | write_unlock(&journal->j_state_lock); |
338 | goto repeat; | |
470decc6 DK |
339 | } |
340 | ||
341 | transaction = journal->j_running_transaction; | |
342 | ||
8f7d89f3 JK |
343 | if (!handle->h_reserved) { |
344 | /* We may have dropped j_state_lock - restart in that case */ | |
345 | if (add_transaction_credits(journal, blocks, rsv_blocks)) | |
346 | goto repeat; | |
347 | } else { | |
470decc6 | 348 | /* |
8f7d89f3 JK |
349 | * We have handle reserved so we are allowed to join T_LOCKED |
350 | * transaction and we don't have to check for transaction size | |
351 | * and journal space. | |
470decc6 | 352 | */ |
8f7d89f3 JK |
353 | sub_reserved_credits(journal, blocks); |
354 | handle->h_reserved = 0; | |
470decc6 DK |
355 | } |
356 | ||
357 | /* OK, account for the buffers that this operation expects to | |
8dd42046 | 358 | * use and add the handle to the running transaction. |
8dd42046 | 359 | */ |
28e35e42 | 360 | update_t_max_wait(transaction, ts); |
470decc6 | 361 | handle->h_transaction = transaction; |
8f7d89f3 | 362 | handle->h_requested_credits = blocks; |
343d9c28 | 363 | handle->h_start_jiffies = jiffies; |
a51dca9c | 364 | atomic_inc(&transaction->t_updates); |
8dd42046 | 365 | atomic_inc(&transaction->t_handle_count); |
8f7d89f3 JK |
366 | jbd_debug(4, "Handle %p given %d credits (total %d, free %lu)\n", |
367 | handle, blocks, | |
a51dca9c | 368 | atomic_read(&transaction->t_outstanding_credits), |
76c39904 | 369 | jbd2_log_space_left(journal)); |
a931da6a | 370 | read_unlock(&journal->j_state_lock); |
41a5b913 | 371 | current->journal_info = handle; |
9599b0e5 JK |
372 | |
373 | lock_map_acquire(&handle->h_lockdep_map); | |
0c2022ec | 374 | jbd2_journal_free_transaction(new_transaction); |
47def826 | 375 | return 0; |
470decc6 DK |
376 | } |
377 | ||
7b751066 MC |
378 | static struct lock_class_key jbd2_handle_key; |
379 | ||
470decc6 DK |
380 | /* Allocate a new handle. This should probably be in a slab... */ |
381 | static handle_t *new_handle(int nblocks) | |
382 | { | |
af1e76d6 | 383 | handle_t *handle = jbd2_alloc_handle(GFP_NOFS); |
470decc6 DK |
384 | if (!handle) |
385 | return NULL; | |
470decc6 DK |
386 | handle->h_buffer_credits = nblocks; |
387 | handle->h_ref = 1; | |
388 | ||
7b751066 MC |
389 | lockdep_init_map(&handle->h_lockdep_map, "jbd2_handle", |
390 | &jbd2_handle_key, 0); | |
391 | ||
470decc6 DK |
392 | return handle; |
393 | } | |
394 | ||
395 | /** | |
f7f4bccb | 396 | * handle_t *jbd2_journal_start() - Obtain a new handle. |
470decc6 DK |
397 | * @journal: Journal to start transaction on. |
398 | * @nblocks: number of block buffer we might modify | |
399 | * | |
400 | * We make sure that the transaction can guarantee at least nblocks of | |
401 | * modified buffers in the log. We block until the log can guarantee | |
8f7d89f3 JK |
402 | * that much space. Additionally, if rsv_blocks > 0, we also create another |
403 | * handle with rsv_blocks reserved blocks in the journal. This handle is | |
404 | * is stored in h_rsv_handle. It is not attached to any particular transaction | |
405 | * and thus doesn't block transaction commit. If the caller uses this reserved | |
406 | * handle, it has to set h_rsv_handle to NULL as otherwise jbd2_journal_stop() | |
407 | * on the parent handle will dispose the reserved one. Reserved handle has to | |
408 | * be converted to a normal handle using jbd2_journal_start_reserved() before | |
409 | * it can be used. | |
470decc6 | 410 | * |
c867516d EG |
411 | * Return a pointer to a newly allocated handle, or an ERR_PTR() value |
412 | * on failure. | |
470decc6 | 413 | */ |
8f7d89f3 JK |
414 | handle_t *jbd2__journal_start(journal_t *journal, int nblocks, int rsv_blocks, |
415 | gfp_t gfp_mask, unsigned int type, | |
416 | unsigned int line_no) | |
470decc6 DK |
417 | { |
418 | handle_t *handle = journal_current_handle(); | |
419 | int err; | |
420 | ||
421 | if (!journal) | |
422 | return ERR_PTR(-EROFS); | |
423 | ||
424 | if (handle) { | |
425 | J_ASSERT(handle->h_transaction->t_journal == journal); | |
426 | handle->h_ref++; | |
427 | return handle; | |
428 | } | |
429 | ||
430 | handle = new_handle(nblocks); | |
431 | if (!handle) | |
432 | return ERR_PTR(-ENOMEM); | |
8f7d89f3 JK |
433 | if (rsv_blocks) { |
434 | handle_t *rsv_handle; | |
435 | ||
436 | rsv_handle = new_handle(rsv_blocks); | |
437 | if (!rsv_handle) { | |
438 | jbd2_free_handle(handle); | |
439 | return ERR_PTR(-ENOMEM); | |
440 | } | |
441 | rsv_handle->h_reserved = 1; | |
442 | rsv_handle->h_journal = journal; | |
443 | handle->h_rsv_handle = rsv_handle; | |
444 | } | |
470decc6 | 445 | |
47def826 | 446 | err = start_this_handle(journal, handle, gfp_mask); |
470decc6 | 447 | if (err < 0) { |
8f7d89f3 JK |
448 | if (handle->h_rsv_handle) |
449 | jbd2_free_handle(handle->h_rsv_handle); | |
af1e76d6 | 450 | jbd2_free_handle(handle); |
df05c1b8 | 451 | return ERR_PTR(err); |
470decc6 | 452 | } |
343d9c28 TT |
453 | handle->h_type = type; |
454 | handle->h_line_no = line_no; | |
455 | trace_jbd2_handle_start(journal->j_fs_dev->bd_dev, | |
456 | handle->h_transaction->t_tid, type, | |
457 | line_no, nblocks); | |
470decc6 DK |
458 | return handle; |
459 | } | |
47def826 TT |
460 | EXPORT_SYMBOL(jbd2__journal_start); |
461 | ||
462 | ||
463 | handle_t *jbd2_journal_start(journal_t *journal, int nblocks) | |
464 | { | |
8f7d89f3 | 465 | return jbd2__journal_start(journal, nblocks, 0, GFP_NOFS, 0, 0); |
47def826 TT |
466 | } |
467 | EXPORT_SYMBOL(jbd2_journal_start); | |
468 | ||
8f7d89f3 JK |
469 | void jbd2_journal_free_reserved(handle_t *handle) |
470 | { | |
471 | journal_t *journal = handle->h_journal; | |
472 | ||
473 | WARN_ON(!handle->h_reserved); | |
474 | sub_reserved_credits(journal, handle->h_buffer_credits); | |
475 | jbd2_free_handle(handle); | |
476 | } | |
477 | EXPORT_SYMBOL(jbd2_journal_free_reserved); | |
478 | ||
479 | /** | |
480 | * int jbd2_journal_start_reserved(handle_t *handle) - start reserved handle | |
481 | * @handle: handle to start | |
482 | * | |
483 | * Start handle that has been previously reserved with jbd2_journal_reserve(). | |
484 | * This attaches @handle to the running transaction (or creates one if there's | |
485 | * not transaction running). Unlike jbd2_journal_start() this function cannot | |
486 | * block on journal commit, checkpointing, or similar stuff. It can block on | |
487 | * memory allocation or frozen journal though. | |
488 | * | |
489 | * Return 0 on success, non-zero on error - handle is freed in that case. | |
490 | */ | |
491 | int jbd2_journal_start_reserved(handle_t *handle, unsigned int type, | |
492 | unsigned int line_no) | |
493 | { | |
494 | journal_t *journal = handle->h_journal; | |
495 | int ret = -EIO; | |
496 | ||
497 | if (WARN_ON(!handle->h_reserved)) { | |
498 | /* Someone passed in normal handle? Just stop it. */ | |
499 | jbd2_journal_stop(handle); | |
500 | return ret; | |
501 | } | |
502 | /* | |
503 | * Usefulness of mixing of reserved and unreserved handles is | |
504 | * questionable. So far nobody seems to need it so just error out. | |
505 | */ | |
506 | if (WARN_ON(current->journal_info)) { | |
507 | jbd2_journal_free_reserved(handle); | |
508 | return ret; | |
509 | } | |
510 | ||
511 | handle->h_journal = NULL; | |
8f7d89f3 JK |
512 | /* |
513 | * GFP_NOFS is here because callers are likely from writeback or | |
514 | * similarly constrained call sites | |
515 | */ | |
516 | ret = start_this_handle(journal, handle, GFP_NOFS); | |
92e3b405 | 517 | if (ret < 0) { |
8f7d89f3 | 518 | jbd2_journal_free_reserved(handle); |
92e3b405 DC |
519 | return ret; |
520 | } | |
8f7d89f3 JK |
521 | handle->h_type = type; |
522 | handle->h_line_no = line_no; | |
92e3b405 | 523 | return 0; |
8f7d89f3 JK |
524 | } |
525 | EXPORT_SYMBOL(jbd2_journal_start_reserved); | |
470decc6 DK |
526 | |
527 | /** | |
f7f4bccb | 528 | * int jbd2_journal_extend() - extend buffer credits. |
470decc6 DK |
529 | * @handle: handle to 'extend' |
530 | * @nblocks: nr blocks to try to extend by. | |
531 | * | |
532 | * Some transactions, such as large extends and truncates, can be done | |
533 | * atomically all at once or in several stages. The operation requests | |
534 | * a credit for a number of buffer modications in advance, but can | |
535 | * extend its credit if it needs more. | |
536 | * | |
f7f4bccb | 537 | * jbd2_journal_extend tries to give the running handle more buffer credits. |
470decc6 DK |
538 | * It does not guarantee that allocation - this is a best-effort only. |
539 | * The calling process MUST be able to deal cleanly with a failure to | |
540 | * extend here. | |
541 | * | |
542 | * Return 0 on success, non-zero on failure. | |
543 | * | |
544 | * return code < 0 implies an error | |
545 | * return code > 0 implies normal transaction-full status. | |
546 | */ | |
f7f4bccb | 547 | int jbd2_journal_extend(handle_t *handle, int nblocks) |
470decc6 DK |
548 | { |
549 | transaction_t *transaction = handle->h_transaction; | |
41a5b913 | 550 | journal_t *journal; |
470decc6 DK |
551 | int result; |
552 | int wanted; | |
553 | ||
470decc6 | 554 | if (is_handle_aborted(handle)) |
41a5b913 TT |
555 | return -EROFS; |
556 | journal = transaction->t_journal; | |
470decc6 DK |
557 | |
558 | result = 1; | |
559 | ||
a931da6a | 560 | read_lock(&journal->j_state_lock); |
470decc6 DK |
561 | |
562 | /* Don't extend a locked-down transaction! */ | |
41a5b913 | 563 | if (transaction->t_state != T_RUNNING) { |
470decc6 DK |
564 | jbd_debug(3, "denied handle %p %d blocks: " |
565 | "transaction not running\n", handle, nblocks); | |
566 | goto error_out; | |
567 | } | |
568 | ||
569 | spin_lock(&transaction->t_handle_lock); | |
fe1e8db5 JK |
570 | wanted = atomic_add_return(nblocks, |
571 | &transaction->t_outstanding_credits); | |
470decc6 DK |
572 | |
573 | if (wanted > journal->j_max_transaction_buffers) { | |
574 | jbd_debug(3, "denied handle %p %d blocks: " | |
575 | "transaction too large\n", handle, nblocks); | |
fe1e8db5 | 576 | atomic_sub(nblocks, &transaction->t_outstanding_credits); |
470decc6 DK |
577 | goto unlock; |
578 | } | |
579 | ||
76c39904 JK |
580 | if (wanted + (wanted >> JBD2_CONTROL_BLOCKS_SHIFT) > |
581 | jbd2_log_space_left(journal)) { | |
470decc6 DK |
582 | jbd_debug(3, "denied handle %p %d blocks: " |
583 | "insufficient log space\n", handle, nblocks); | |
fe1e8db5 | 584 | atomic_sub(nblocks, &transaction->t_outstanding_credits); |
470decc6 DK |
585 | goto unlock; |
586 | } | |
587 | ||
343d9c28 | 588 | trace_jbd2_handle_extend(journal->j_fs_dev->bd_dev, |
41a5b913 | 589 | transaction->t_tid, |
343d9c28 TT |
590 | handle->h_type, handle->h_line_no, |
591 | handle->h_buffer_credits, | |
592 | nblocks); | |
593 | ||
470decc6 | 594 | handle->h_buffer_credits += nblocks; |
343d9c28 | 595 | handle->h_requested_credits += nblocks; |
470decc6 DK |
596 | result = 0; |
597 | ||
598 | jbd_debug(3, "extended handle %p by %d\n", handle, nblocks); | |
599 | unlock: | |
600 | spin_unlock(&transaction->t_handle_lock); | |
601 | error_out: | |
a931da6a | 602 | read_unlock(&journal->j_state_lock); |
470decc6 DK |
603 | return result; |
604 | } | |
605 | ||
606 | ||
607 | /** | |
f7f4bccb | 608 | * int jbd2_journal_restart() - restart a handle . |
470decc6 DK |
609 | * @handle: handle to restart |
610 | * @nblocks: nr credits requested | |
611 | * | |
612 | * Restart a handle for a multi-transaction filesystem | |
613 | * operation. | |
614 | * | |
f7f4bccb MC |
615 | * If the jbd2_journal_extend() call above fails to grant new buffer credits |
616 | * to a running handle, a call to jbd2_journal_restart will commit the | |
470decc6 DK |
617 | * handle's transaction so far and reattach the handle to a new |
618 | * transaction capabable of guaranteeing the requested number of | |
8f7d89f3 JK |
619 | * credits. We preserve reserved handle if there's any attached to the |
620 | * passed in handle. | |
470decc6 | 621 | */ |
d2159fb7 | 622 | int jbd2__journal_restart(handle_t *handle, int nblocks, gfp_t gfp_mask) |
470decc6 DK |
623 | { |
624 | transaction_t *transaction = handle->h_transaction; | |
41a5b913 | 625 | journal_t *journal; |
e4471831 TT |
626 | tid_t tid; |
627 | int need_to_start, ret; | |
470decc6 DK |
628 | |
629 | /* If we've had an abort of any type, don't even think about | |
630 | * actually doing the restart! */ | |
631 | if (is_handle_aborted(handle)) | |
632 | return 0; | |
41a5b913 | 633 | journal = transaction->t_journal; |
470decc6 DK |
634 | |
635 | /* | |
636 | * First unlink the handle from its current transaction, and start the | |
637 | * commit on that. | |
638 | */ | |
a51dca9c | 639 | J_ASSERT(atomic_read(&transaction->t_updates) > 0); |
470decc6 DK |
640 | J_ASSERT(journal_current_handle() == handle); |
641 | ||
a931da6a | 642 | read_lock(&journal->j_state_lock); |
470decc6 | 643 | spin_lock(&transaction->t_handle_lock); |
a51dca9c TT |
644 | atomic_sub(handle->h_buffer_credits, |
645 | &transaction->t_outstanding_credits); | |
8f7d89f3 JK |
646 | if (handle->h_rsv_handle) { |
647 | sub_reserved_credits(journal, | |
648 | handle->h_rsv_handle->h_buffer_credits); | |
649 | } | |
a51dca9c | 650 | if (atomic_dec_and_test(&transaction->t_updates)) |
470decc6 | 651 | wake_up(&journal->j_wait_updates); |
39c04153 | 652 | tid = transaction->t_tid; |
470decc6 | 653 | spin_unlock(&transaction->t_handle_lock); |
41a5b913 TT |
654 | handle->h_transaction = NULL; |
655 | current->journal_info = NULL; | |
470decc6 DK |
656 | |
657 | jbd_debug(2, "restarting handle %p\n", handle); | |
e4471831 | 658 | need_to_start = !tid_geq(journal->j_commit_request, tid); |
a931da6a | 659 | read_unlock(&journal->j_state_lock); |
e4471831 TT |
660 | if (need_to_start) |
661 | jbd2_log_start_commit(journal, tid); | |
470decc6 | 662 | |
9599b0e5 | 663 | lock_map_release(&handle->h_lockdep_map); |
470decc6 | 664 | handle->h_buffer_credits = nblocks; |
47def826 | 665 | ret = start_this_handle(journal, handle, gfp_mask); |
470decc6 DK |
666 | return ret; |
667 | } | |
47def826 | 668 | EXPORT_SYMBOL(jbd2__journal_restart); |
470decc6 DK |
669 | |
670 | ||
47def826 TT |
671 | int jbd2_journal_restart(handle_t *handle, int nblocks) |
672 | { | |
673 | return jbd2__journal_restart(handle, nblocks, GFP_NOFS); | |
674 | } | |
675 | EXPORT_SYMBOL(jbd2_journal_restart); | |
676 | ||
470decc6 | 677 | /** |
f7f4bccb | 678 | * void jbd2_journal_lock_updates () - establish a transaction barrier. |
470decc6 DK |
679 | * @journal: Journal to establish a barrier on. |
680 | * | |
681 | * This locks out any further updates from being started, and blocks | |
682 | * until all existing updates have completed, returning only once the | |
683 | * journal is in a quiescent state with no updates running. | |
684 | * | |
685 | * The journal lock should not be held on entry. | |
686 | */ | |
f7f4bccb | 687 | void jbd2_journal_lock_updates(journal_t *journal) |
470decc6 DK |
688 | { |
689 | DEFINE_WAIT(wait); | |
690 | ||
a931da6a | 691 | write_lock(&journal->j_state_lock); |
470decc6 DK |
692 | ++journal->j_barrier_count; |
693 | ||
8f7d89f3 JK |
694 | /* Wait until there are no reserved handles */ |
695 | if (atomic_read(&journal->j_reserved_credits)) { | |
696 | write_unlock(&journal->j_state_lock); | |
697 | wait_event(journal->j_wait_reserved, | |
698 | atomic_read(&journal->j_reserved_credits) == 0); | |
699 | write_lock(&journal->j_state_lock); | |
700 | } | |
701 | ||
470decc6 DK |
702 | /* Wait until there are no running updates */ |
703 | while (1) { | |
704 | transaction_t *transaction = journal->j_running_transaction; | |
705 | ||
706 | if (!transaction) | |
707 | break; | |
708 | ||
709 | spin_lock(&transaction->t_handle_lock); | |
9837d8e9 JK |
710 | prepare_to_wait(&journal->j_wait_updates, &wait, |
711 | TASK_UNINTERRUPTIBLE); | |
a51dca9c | 712 | if (!atomic_read(&transaction->t_updates)) { |
470decc6 | 713 | spin_unlock(&transaction->t_handle_lock); |
9837d8e9 | 714 | finish_wait(&journal->j_wait_updates, &wait); |
470decc6 DK |
715 | break; |
716 | } | |
470decc6 | 717 | spin_unlock(&transaction->t_handle_lock); |
a931da6a | 718 | write_unlock(&journal->j_state_lock); |
470decc6 DK |
719 | schedule(); |
720 | finish_wait(&journal->j_wait_updates, &wait); | |
a931da6a | 721 | write_lock(&journal->j_state_lock); |
470decc6 | 722 | } |
a931da6a | 723 | write_unlock(&journal->j_state_lock); |
470decc6 DK |
724 | |
725 | /* | |
726 | * We have now established a barrier against other normal updates, but | |
f7f4bccb | 727 | * we also need to barrier against other jbd2_journal_lock_updates() calls |
470decc6 DK |
728 | * to make sure that we serialise special journal-locked operations |
729 | * too. | |
730 | */ | |
731 | mutex_lock(&journal->j_barrier); | |
732 | } | |
733 | ||
734 | /** | |
f7f4bccb | 735 | * void jbd2_journal_unlock_updates (journal_t* journal) - release barrier |
470decc6 DK |
736 | * @journal: Journal to release the barrier on. |
737 | * | |
f7f4bccb | 738 | * Release a transaction barrier obtained with jbd2_journal_lock_updates(). |
470decc6 DK |
739 | * |
740 | * Should be called without the journal lock held. | |
741 | */ | |
f7f4bccb | 742 | void jbd2_journal_unlock_updates (journal_t *journal) |
470decc6 DK |
743 | { |
744 | J_ASSERT(journal->j_barrier_count != 0); | |
745 | ||
746 | mutex_unlock(&journal->j_barrier); | |
a931da6a | 747 | write_lock(&journal->j_state_lock); |
470decc6 | 748 | --journal->j_barrier_count; |
a931da6a | 749 | write_unlock(&journal->j_state_lock); |
470decc6 DK |
750 | wake_up(&journal->j_wait_transaction_locked); |
751 | } | |
752 | ||
f91d1d04 | 753 | static void warn_dirty_buffer(struct buffer_head *bh) |
470decc6 | 754 | { |
f91d1d04 | 755 | char b[BDEVNAME_SIZE]; |
470decc6 | 756 | |
f91d1d04 | 757 | printk(KERN_WARNING |
f2a44523 | 758 | "JBD2: Spotted dirty metadata buffer (dev = %s, blocknr = %llu). " |
f91d1d04 JK |
759 | "There's a risk of filesystem corruption in case of system " |
760 | "crash.\n", | |
761 | bdevname(bh->b_bdev, b), (unsigned long long)bh->b_blocknr); | |
470decc6 DK |
762 | } |
763 | ||
764 | /* | |
765 | * If the buffer is already part of the current transaction, then there | |
766 | * is nothing we need to do. If it is already part of a prior | |
767 | * transaction which we are still committing to disk, then we need to | |
768 | * make sure that we do not overwrite the old copy: we do copy-out to | |
769 | * preserve the copy going to disk. We also account the buffer against | |
770 | * the handle's metadata buffer credits (unless the buffer is already | |
771 | * part of the transaction, that is). | |
772 | * | |
773 | */ | |
774 | static int | |
775 | do_get_write_access(handle_t *handle, struct journal_head *jh, | |
776 | int force_copy) | |
777 | { | |
778 | struct buffer_head *bh; | |
41a5b913 | 779 | transaction_t *transaction = handle->h_transaction; |
470decc6 DK |
780 | journal_t *journal; |
781 | int error; | |
782 | char *frozen_buffer = NULL; | |
783 | int need_copy = 0; | |
f783f091 | 784 | unsigned long start_lock, time_lock; |
470decc6 DK |
785 | |
786 | if (is_handle_aborted(handle)) | |
787 | return -EROFS; | |
470decc6 DK |
788 | journal = transaction->t_journal; |
789 | ||
cfef2c6a | 790 | jbd_debug(5, "journal_head %p, force_copy %d\n", jh, force_copy); |
470decc6 DK |
791 | |
792 | JBUFFER_TRACE(jh, "entry"); | |
793 | repeat: | |
794 | bh = jh2bh(jh); | |
795 | ||
796 | /* @@@ Need to check for errors here at some point. */ | |
797 | ||
f783f091 | 798 | start_lock = jiffies; |
470decc6 DK |
799 | lock_buffer(bh); |
800 | jbd_lock_bh_state(bh); | |
801 | ||
f783f091 TT |
802 | /* If it takes too long to lock the buffer, trace it */ |
803 | time_lock = jbd2_time_diff(start_lock, jiffies); | |
804 | if (time_lock > HZ/10) | |
805 | trace_jbd2_lock_buffer_stall(bh->b_bdev->bd_dev, | |
806 | jiffies_to_msecs(time_lock)); | |
807 | ||
470decc6 DK |
808 | /* We now hold the buffer lock so it is safe to query the buffer |
809 | * state. Is the buffer dirty? | |
810 | * | |
811 | * If so, there are two possibilities. The buffer may be | |
812 | * non-journaled, and undergoing a quite legitimate writeback. | |
813 | * Otherwise, it is journaled, and we don't expect dirty buffers | |
814 | * in that state (the buffers should be marked JBD_Dirty | |
815 | * instead.) So either the IO is being done under our own | |
816 | * control and this is a bug, or it's a third party IO such as | |
817 | * dump(8) (which may leave the buffer scheduled for read --- | |
818 | * ie. locked but not dirty) or tune2fs (which may actually have | |
819 | * the buffer dirtied, ugh.) */ | |
820 | ||
821 | if (buffer_dirty(bh)) { | |
822 | /* | |
823 | * First question: is this buffer already part of the current | |
824 | * transaction or the existing committing transaction? | |
825 | */ | |
826 | if (jh->b_transaction) { | |
827 | J_ASSERT_JH(jh, | |
828 | jh->b_transaction == transaction || | |
829 | jh->b_transaction == | |
830 | journal->j_committing_transaction); | |
831 | if (jh->b_next_transaction) | |
832 | J_ASSERT_JH(jh, jh->b_next_transaction == | |
833 | transaction); | |
f91d1d04 | 834 | warn_dirty_buffer(bh); |
470decc6 DK |
835 | } |
836 | /* | |
837 | * In any case we need to clean the dirty flag and we must | |
838 | * do it under the buffer lock to be sure we don't race | |
839 | * with running write-out. | |
840 | */ | |
f91d1d04 JK |
841 | JBUFFER_TRACE(jh, "Journalling dirty buffer"); |
842 | clear_buffer_dirty(bh); | |
843 | set_buffer_jbddirty(bh); | |
470decc6 DK |
844 | } |
845 | ||
846 | unlock_buffer(bh); | |
847 | ||
848 | error = -EROFS; | |
849 | if (is_handle_aborted(handle)) { | |
850 | jbd_unlock_bh_state(bh); | |
851 | goto out; | |
852 | } | |
853 | error = 0; | |
854 | ||
855 | /* | |
856 | * The buffer is already part of this transaction if b_transaction or | |
857 | * b_next_transaction points to it | |
858 | */ | |
859 | if (jh->b_transaction == transaction || | |
860 | jh->b_next_transaction == transaction) | |
861 | goto done; | |
862 | ||
9fc7c63a JB |
863 | /* |
864 | * this is the first time this transaction is touching this buffer, | |
865 | * reset the modified flag | |
866 | */ | |
867 | jh->b_modified = 0; | |
868 | ||
470decc6 DK |
869 | /* |
870 | * If there is already a copy-out version of this buffer, then we don't | |
871 | * need to make another one | |
872 | */ | |
873 | if (jh->b_frozen_data) { | |
874 | JBUFFER_TRACE(jh, "has frozen data"); | |
875 | J_ASSERT_JH(jh, jh->b_next_transaction == NULL); | |
876 | jh->b_next_transaction = transaction; | |
877 | goto done; | |
878 | } | |
879 | ||
880 | /* Is there data here we need to preserve? */ | |
881 | ||
882 | if (jh->b_transaction && jh->b_transaction != transaction) { | |
883 | JBUFFER_TRACE(jh, "owned by older transaction"); | |
884 | J_ASSERT_JH(jh, jh->b_next_transaction == NULL); | |
885 | J_ASSERT_JH(jh, jh->b_transaction == | |
886 | journal->j_committing_transaction); | |
887 | ||
888 | /* There is one case we have to be very careful about. | |
889 | * If the committing transaction is currently writing | |
890 | * this buffer out to disk and has NOT made a copy-out, | |
891 | * then we cannot modify the buffer contents at all | |
892 | * right now. The essence of copy-out is that it is the | |
893 | * extra copy, not the primary copy, which gets | |
894 | * journaled. If the primary copy is already going to | |
895 | * disk then we cannot do copy-out here. */ | |
896 | ||
b34090e5 | 897 | if (buffer_shadow(bh)) { |
470decc6 DK |
898 | JBUFFER_TRACE(jh, "on shadow: sleep"); |
899 | jbd_unlock_bh_state(bh); | |
74316201 N |
900 | wait_on_bit_io(&bh->b_state, BH_Shadow, |
901 | TASK_UNINTERRUPTIBLE); | |
470decc6 DK |
902 | goto repeat; |
903 | } | |
904 | ||
b34090e5 JK |
905 | /* |
906 | * Only do the copy if the currently-owning transaction still | |
907 | * needs it. If buffer isn't on BJ_Metadata list, the | |
908 | * committing transaction is past that stage (here we use the | |
909 | * fact that BH_Shadow is set under bh_state lock together with | |
910 | * refiling to BJ_Shadow list and at this point we know the | |
911 | * buffer doesn't have BH_Shadow set). | |
470decc6 DK |
912 | * |
913 | * Subtle point, though: if this is a get_undo_access, | |
914 | * then we will be relying on the frozen_data to contain | |
915 | * the new value of the committed_data record after the | |
916 | * transaction, so we HAVE to force the frozen_data copy | |
b34090e5 JK |
917 | * in that case. |
918 | */ | |
919 | if (jh->b_jlist == BJ_Metadata || force_copy) { | |
470decc6 DK |
920 | JBUFFER_TRACE(jh, "generate frozen data"); |
921 | if (!frozen_buffer) { | |
922 | JBUFFER_TRACE(jh, "allocate memory for buffer"); | |
923 | jbd_unlock_bh_state(bh); | |
924 | frozen_buffer = | |
af1e76d6 | 925 | jbd2_alloc(jh2bh(jh)->b_size, |
470decc6 DK |
926 | GFP_NOFS); |
927 | if (!frozen_buffer) { | |
75685071 | 928 | printk(KERN_ERR |
470decc6 | 929 | "%s: OOM for frozen_buffer\n", |
329d291f | 930 | __func__); |
470decc6 DK |
931 | JBUFFER_TRACE(jh, "oom!"); |
932 | error = -ENOMEM; | |
933 | jbd_lock_bh_state(bh); | |
934 | goto done; | |
935 | } | |
936 | goto repeat; | |
937 | } | |
938 | jh->b_frozen_data = frozen_buffer; | |
939 | frozen_buffer = NULL; | |
940 | need_copy = 1; | |
941 | } | |
942 | jh->b_next_transaction = transaction; | |
943 | } | |
944 | ||
945 | ||
946 | /* | |
947 | * Finally, if the buffer is not journaled right now, we need to make | |
948 | * sure it doesn't get written to disk before the caller actually | |
949 | * commits the new data | |
950 | */ | |
951 | if (!jh->b_transaction) { | |
952 | JBUFFER_TRACE(jh, "no transaction"); | |
953 | J_ASSERT_JH(jh, !jh->b_next_transaction); | |
470decc6 DK |
954 | JBUFFER_TRACE(jh, "file as BJ_Reserved"); |
955 | spin_lock(&journal->j_list_lock); | |
f7f4bccb | 956 | __jbd2_journal_file_buffer(jh, transaction, BJ_Reserved); |
470decc6 DK |
957 | spin_unlock(&journal->j_list_lock); |
958 | } | |
959 | ||
960 | done: | |
961 | if (need_copy) { | |
962 | struct page *page; | |
963 | int offset; | |
964 | char *source; | |
965 | ||
966 | J_EXPECT_JH(jh, buffer_uptodate(jh2bh(jh)), | |
967 | "Possible IO failure.\n"); | |
968 | page = jh2bh(jh)->b_page; | |
a1dd5331 | 969 | offset = offset_in_page(jh2bh(jh)->b_data); |
303a8f2a | 970 | source = kmap_atomic(page); |
13ceef09 JK |
971 | /* Fire data frozen trigger just before we copy the data */ |
972 | jbd2_buffer_frozen_trigger(jh, source + offset, | |
973 | jh->b_triggers); | |
470decc6 | 974 | memcpy(jh->b_frozen_data, source+offset, jh2bh(jh)->b_size); |
303a8f2a | 975 | kunmap_atomic(source); |
e06c8227 JB |
976 | |
977 | /* | |
978 | * Now that the frozen data is saved off, we need to store | |
979 | * any matching triggers. | |
980 | */ | |
981 | jh->b_frozen_triggers = jh->b_triggers; | |
470decc6 DK |
982 | } |
983 | jbd_unlock_bh_state(bh); | |
984 | ||
985 | /* | |
986 | * If we are about to journal a buffer, then any revoke pending on it is | |
987 | * no longer valid | |
988 | */ | |
f7f4bccb | 989 | jbd2_journal_cancel_revoke(handle, jh); |
470decc6 DK |
990 | |
991 | out: | |
992 | if (unlikely(frozen_buffer)) /* It's usually NULL */ | |
af1e76d6 | 993 | jbd2_free(frozen_buffer, bh->b_size); |
470decc6 DK |
994 | |
995 | JBUFFER_TRACE(jh, "exit"); | |
996 | return error; | |
997 | } | |
998 | ||
999 | /** | |
f7f4bccb | 1000 | * int jbd2_journal_get_write_access() - notify intent to modify a buffer for metadata (not data) update. |
470decc6 DK |
1001 | * @handle: transaction to add buffer modifications to |
1002 | * @bh: bh to be used for metadata writes | |
470decc6 DK |
1003 | * |
1004 | * Returns an error code or 0 on success. | |
1005 | * | |
1006 | * In full data journalling mode the buffer may be of type BJ_AsyncData, | |
1007 | * because we're write()ing a buffer which is also part of a shared mapping. | |
1008 | */ | |
1009 | ||
f7f4bccb | 1010 | int jbd2_journal_get_write_access(handle_t *handle, struct buffer_head *bh) |
470decc6 | 1011 | { |
f7f4bccb | 1012 | struct journal_head *jh = jbd2_journal_add_journal_head(bh); |
470decc6 DK |
1013 | int rc; |
1014 | ||
1015 | /* We do not want to get caught playing with fields which the | |
1016 | * log thread also manipulates. Make sure that the buffer | |
1017 | * completes any outstanding IO before proceeding. */ | |
1018 | rc = do_get_write_access(handle, jh, 0); | |
f7f4bccb | 1019 | jbd2_journal_put_journal_head(jh); |
470decc6 DK |
1020 | return rc; |
1021 | } | |
1022 | ||
1023 | ||
1024 | /* | |
1025 | * When the user wants to journal a newly created buffer_head | |
1026 | * (ie. getblk() returned a new buffer and we are going to populate it | |
1027 | * manually rather than reading off disk), then we need to keep the | |
1028 | * buffer_head locked until it has been completely filled with new | |
1029 | * data. In this case, we should be able to make the assertion that | |
1030 | * the bh is not already part of an existing transaction. | |
1031 | * | |
1032 | * The buffer should already be locked by the caller by this point. | |
1033 | * There is no lock ranking violation: it was a newly created, | |
1034 | * unlocked buffer beforehand. */ | |
1035 | ||
1036 | /** | |
f7f4bccb | 1037 | * int jbd2_journal_get_create_access () - notify intent to use newly created bh |
470decc6 DK |
1038 | * @handle: transaction to new buffer to |
1039 | * @bh: new buffer. | |
1040 | * | |
1041 | * Call this if you create a new bh. | |
1042 | */ | |
f7f4bccb | 1043 | int jbd2_journal_get_create_access(handle_t *handle, struct buffer_head *bh) |
470decc6 DK |
1044 | { |
1045 | transaction_t *transaction = handle->h_transaction; | |
41a5b913 | 1046 | journal_t *journal; |
f7f4bccb | 1047 | struct journal_head *jh = jbd2_journal_add_journal_head(bh); |
470decc6 DK |
1048 | int err; |
1049 | ||
1050 | jbd_debug(5, "journal_head %p\n", jh); | |
1051 | err = -EROFS; | |
1052 | if (is_handle_aborted(handle)) | |
1053 | goto out; | |
41a5b913 | 1054 | journal = transaction->t_journal; |
470decc6 DK |
1055 | err = 0; |
1056 | ||
1057 | JBUFFER_TRACE(jh, "entry"); | |
1058 | /* | |
1059 | * The buffer may already belong to this transaction due to pre-zeroing | |
1060 | * in the filesystem's new_block code. It may also be on the previous, | |
1061 | * committing transaction's lists, but it HAS to be in Forget state in | |
1062 | * that case: the transaction must have deleted the buffer for it to be | |
1063 | * reused here. | |
1064 | */ | |
1065 | jbd_lock_bh_state(bh); | |
470decc6 DK |
1066 | J_ASSERT_JH(jh, (jh->b_transaction == transaction || |
1067 | jh->b_transaction == NULL || | |
1068 | (jh->b_transaction == journal->j_committing_transaction && | |
1069 | jh->b_jlist == BJ_Forget))); | |
1070 | ||
1071 | J_ASSERT_JH(jh, jh->b_next_transaction == NULL); | |
1072 | J_ASSERT_JH(jh, buffer_locked(jh2bh(jh))); | |
1073 | ||
1074 | if (jh->b_transaction == NULL) { | |
f91d1d04 JK |
1075 | /* |
1076 | * Previous jbd2_journal_forget() could have left the buffer | |
1077 | * with jbddirty bit set because it was being committed. When | |
1078 | * the commit finished, we've filed the buffer for | |
1079 | * checkpointing and marked it dirty. Now we are reallocating | |
1080 | * the buffer so the transaction freeing it must have | |
1081 | * committed and so it's safe to clear the dirty bit. | |
1082 | */ | |
1083 | clear_buffer_dirty(jh2bh(jh)); | |
9fc7c63a JB |
1084 | /* first access by this transaction */ |
1085 | jh->b_modified = 0; | |
1086 | ||
470decc6 | 1087 | JBUFFER_TRACE(jh, "file as BJ_Reserved"); |
6e4862a5 | 1088 | spin_lock(&journal->j_list_lock); |
f7f4bccb | 1089 | __jbd2_journal_file_buffer(jh, transaction, BJ_Reserved); |
470decc6 | 1090 | } else if (jh->b_transaction == journal->j_committing_transaction) { |
9fc7c63a JB |
1091 | /* first access by this transaction */ |
1092 | jh->b_modified = 0; | |
1093 | ||
470decc6 | 1094 | JBUFFER_TRACE(jh, "set next transaction"); |
6e4862a5 | 1095 | spin_lock(&journal->j_list_lock); |
470decc6 DK |
1096 | jh->b_next_transaction = transaction; |
1097 | } | |
1098 | spin_unlock(&journal->j_list_lock); | |
1099 | jbd_unlock_bh_state(bh); | |
1100 | ||
1101 | /* | |
1102 | * akpm: I added this. ext3_alloc_branch can pick up new indirect | |
1103 | * blocks which contain freed but then revoked metadata. We need | |
1104 | * to cancel the revoke in case we end up freeing it yet again | |
1105 | * and the reallocating as data - this would cause a second revoke, | |
1106 | * which hits an assertion error. | |
1107 | */ | |
1108 | JBUFFER_TRACE(jh, "cancelling revoke"); | |
f7f4bccb | 1109 | jbd2_journal_cancel_revoke(handle, jh); |
470decc6 | 1110 | out: |
3991b400 | 1111 | jbd2_journal_put_journal_head(jh); |
470decc6 DK |
1112 | return err; |
1113 | } | |
1114 | ||
1115 | /** | |
f7f4bccb | 1116 | * int jbd2_journal_get_undo_access() - Notify intent to modify metadata with |
470decc6 DK |
1117 | * non-rewindable consequences |
1118 | * @handle: transaction | |
1119 | * @bh: buffer to undo | |
470decc6 DK |
1120 | * |
1121 | * Sometimes there is a need to distinguish between metadata which has | |
1122 | * been committed to disk and that which has not. The ext3fs code uses | |
1123 | * this for freeing and allocating space, we have to make sure that we | |
1124 | * do not reuse freed space until the deallocation has been committed, | |
1125 | * since if we overwrote that space we would make the delete | |
1126 | * un-rewindable in case of a crash. | |
1127 | * | |
f7f4bccb | 1128 | * To deal with that, jbd2_journal_get_undo_access requests write access to a |
470decc6 DK |
1129 | * buffer for parts of non-rewindable operations such as delete |
1130 | * operations on the bitmaps. The journaling code must keep a copy of | |
1131 | * the buffer's contents prior to the undo_access call until such time | |
1132 | * as we know that the buffer has definitely been committed to disk. | |
1133 | * | |
1134 | * We never need to know which transaction the committed data is part | |
1135 | * of, buffers touched here are guaranteed to be dirtied later and so | |
1136 | * will be committed to a new transaction in due course, at which point | |
1137 | * we can discard the old committed data pointer. | |
1138 | * | |
1139 | * Returns error number or 0 on success. | |
1140 | */ | |
f7f4bccb | 1141 | int jbd2_journal_get_undo_access(handle_t *handle, struct buffer_head *bh) |
470decc6 DK |
1142 | { |
1143 | int err; | |
f7f4bccb | 1144 | struct journal_head *jh = jbd2_journal_add_journal_head(bh); |
470decc6 DK |
1145 | char *committed_data = NULL; |
1146 | ||
1147 | JBUFFER_TRACE(jh, "entry"); | |
1148 | ||
1149 | /* | |
1150 | * Do this first --- it can drop the journal lock, so we want to | |
1151 | * make sure that obtaining the committed_data is done | |
1152 | * atomically wrt. completion of any outstanding commits. | |
1153 | */ | |
1154 | err = do_get_write_access(handle, jh, 1); | |
1155 | if (err) | |
1156 | goto out; | |
1157 | ||
1158 | repeat: | |
1159 | if (!jh->b_committed_data) { | |
af1e76d6 | 1160 | committed_data = jbd2_alloc(jh2bh(jh)->b_size, GFP_NOFS); |
470decc6 | 1161 | if (!committed_data) { |
75685071 | 1162 | printk(KERN_ERR "%s: No memory for committed data\n", |
329d291f | 1163 | __func__); |
470decc6 DK |
1164 | err = -ENOMEM; |
1165 | goto out; | |
1166 | } | |
1167 | } | |
1168 | ||
1169 | jbd_lock_bh_state(bh); | |
1170 | if (!jh->b_committed_data) { | |
1171 | /* Copy out the current buffer contents into the | |
1172 | * preserved, committed copy. */ | |
1173 | JBUFFER_TRACE(jh, "generate b_committed data"); | |
1174 | if (!committed_data) { | |
1175 | jbd_unlock_bh_state(bh); | |
1176 | goto repeat; | |
1177 | } | |
1178 | ||
1179 | jh->b_committed_data = committed_data; | |
1180 | committed_data = NULL; | |
1181 | memcpy(jh->b_committed_data, bh->b_data, bh->b_size); | |
1182 | } | |
1183 | jbd_unlock_bh_state(bh); | |
1184 | out: | |
f7f4bccb | 1185 | jbd2_journal_put_journal_head(jh); |
470decc6 | 1186 | if (unlikely(committed_data)) |
af1e76d6 | 1187 | jbd2_free(committed_data, bh->b_size); |
470decc6 DK |
1188 | return err; |
1189 | } | |
1190 | ||
e06c8227 JB |
1191 | /** |
1192 | * void jbd2_journal_set_triggers() - Add triggers for commit writeout | |
1193 | * @bh: buffer to trigger on | |
1194 | * @type: struct jbd2_buffer_trigger_type containing the trigger(s). | |
1195 | * | |
1196 | * Set any triggers on this journal_head. This is always safe, because | |
1197 | * triggers for a committing buffer will be saved off, and triggers for | |
1198 | * a running transaction will match the buffer in that transaction. | |
1199 | * | |
1200 | * Call with NULL to clear the triggers. | |
1201 | */ | |
1202 | void jbd2_journal_set_triggers(struct buffer_head *bh, | |
1203 | struct jbd2_buffer_trigger_type *type) | |
1204 | { | |
ad56edad | 1205 | struct journal_head *jh = jbd2_journal_grab_journal_head(bh); |
e06c8227 | 1206 | |
ad56edad JK |
1207 | if (WARN_ON(!jh)) |
1208 | return; | |
e06c8227 | 1209 | jh->b_triggers = type; |
ad56edad | 1210 | jbd2_journal_put_journal_head(jh); |
e06c8227 JB |
1211 | } |
1212 | ||
13ceef09 | 1213 | void jbd2_buffer_frozen_trigger(struct journal_head *jh, void *mapped_data, |
e06c8227 JB |
1214 | struct jbd2_buffer_trigger_type *triggers) |
1215 | { | |
1216 | struct buffer_head *bh = jh2bh(jh); | |
1217 | ||
13ceef09 | 1218 | if (!triggers || !triggers->t_frozen) |
e06c8227 JB |
1219 | return; |
1220 | ||
13ceef09 | 1221 | triggers->t_frozen(triggers, bh, mapped_data, bh->b_size); |
e06c8227 JB |
1222 | } |
1223 | ||
1224 | void jbd2_buffer_abort_trigger(struct journal_head *jh, | |
1225 | struct jbd2_buffer_trigger_type *triggers) | |
1226 | { | |
1227 | if (!triggers || !triggers->t_abort) | |
1228 | return; | |
1229 | ||
1230 | triggers->t_abort(triggers, jh2bh(jh)); | |
1231 | } | |
1232 | ||
1233 | ||
1234 | ||
470decc6 | 1235 | /** |
f7f4bccb | 1236 | * int jbd2_journal_dirty_metadata() - mark a buffer as containing dirty metadata |
470decc6 DK |
1237 | * @handle: transaction to add buffer to. |
1238 | * @bh: buffer to mark | |
1239 | * | |
1240 | * mark dirty metadata which needs to be journaled as part of the current | |
1241 | * transaction. | |
1242 | * | |
9ea7a0df TT |
1243 | * The buffer must have previously had jbd2_journal_get_write_access() |
1244 | * called so that it has a valid journal_head attached to the buffer | |
1245 | * head. | |
1246 | * | |
470decc6 DK |
1247 | * The buffer is placed on the transaction's metadata list and is marked |
1248 | * as belonging to the transaction. | |
1249 | * | |
1250 | * Returns error number or 0 on success. | |
1251 | * | |
1252 | * Special care needs to be taken if the buffer already belongs to the | |
1253 | * current committing transaction (in which case we should have frozen | |
1254 | * data present for that commit). In that case, we don't relink the | |
1255 | * buffer: that only gets done when the old transaction finally | |
1256 | * completes its commit. | |
1257 | */ | |
f7f4bccb | 1258 | int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh) |
470decc6 DK |
1259 | { |
1260 | transaction_t *transaction = handle->h_transaction; | |
41a5b913 | 1261 | journal_t *journal; |
ad56edad | 1262 | struct journal_head *jh; |
9ea7a0df | 1263 | int ret = 0; |
470decc6 | 1264 | |
470decc6 | 1265 | if (is_handle_aborted(handle)) |
41a5b913 TT |
1266 | return -EROFS; |
1267 | journal = transaction->t_journal; | |
ad56edad JK |
1268 | jh = jbd2_journal_grab_journal_head(bh); |
1269 | if (!jh) { | |
9ea7a0df TT |
1270 | ret = -EUCLEAN; |
1271 | goto out; | |
1272 | } | |
ad56edad JK |
1273 | jbd_debug(5, "journal_head %p\n", jh); |
1274 | JBUFFER_TRACE(jh, "entry"); | |
470decc6 DK |
1275 | |
1276 | jbd_lock_bh_state(bh); | |
1277 | ||
1278 | if (jh->b_modified == 0) { | |
1279 | /* | |
1280 | * This buffer's got modified and becoming part | |
1281 | * of the transaction. This needs to be done | |
1282 | * once a transaction -bzzz | |
1283 | */ | |
1284 | jh->b_modified = 1; | |
f6c07cad TT |
1285 | if (handle->h_buffer_credits <= 0) { |
1286 | ret = -ENOSPC; | |
1287 | goto out_unlock_bh; | |
1288 | } | |
470decc6 DK |
1289 | handle->h_buffer_credits--; |
1290 | } | |
1291 | ||
1292 | /* | |
1293 | * fastpath, to avoid expensive locking. If this buffer is already | |
1294 | * on the running transaction's metadata list there is nothing to do. | |
1295 | * Nobody can take it off again because there is a handle open. | |
1296 | * I _think_ we're OK here with SMP barriers - a mistaken decision will | |
1297 | * result in this test being false, so we go in and take the locks. | |
1298 | */ | |
1299 | if (jh->b_transaction == transaction && jh->b_jlist == BJ_Metadata) { | |
1300 | JBUFFER_TRACE(jh, "fastpath"); | |
9ea7a0df TT |
1301 | if (unlikely(jh->b_transaction != |
1302 | journal->j_running_transaction)) { | |
a67c848a | 1303 | printk(KERN_ERR "JBD2: %s: " |
9ea7a0df | 1304 | "jh->b_transaction (%llu, %p, %u) != " |
66a4cb18 | 1305 | "journal->j_running_transaction (%p, %u)\n", |
9ea7a0df TT |
1306 | journal->j_devname, |
1307 | (unsigned long long) bh->b_blocknr, | |
1308 | jh->b_transaction, | |
1309 | jh->b_transaction ? jh->b_transaction->t_tid : 0, | |
1310 | journal->j_running_transaction, | |
1311 | journal->j_running_transaction ? | |
1312 | journal->j_running_transaction->t_tid : 0); | |
1313 | ret = -EINVAL; | |
1314 | } | |
470decc6 DK |
1315 | goto out_unlock_bh; |
1316 | } | |
1317 | ||
1318 | set_buffer_jbddirty(bh); | |
1319 | ||
1320 | /* | |
1321 | * Metadata already on the current transaction list doesn't | |
1322 | * need to be filed. Metadata on another transaction's list must | |
1323 | * be committing, and will be refiled once the commit completes: | |
1324 | * leave it alone for now. | |
1325 | */ | |
1326 | if (jh->b_transaction != transaction) { | |
1327 | JBUFFER_TRACE(jh, "already on other transaction"); | |
66a4cb18 TT |
1328 | if (unlikely(((jh->b_transaction != |
1329 | journal->j_committing_transaction)) || | |
1330 | (jh->b_next_transaction != transaction))) { | |
1331 | printk(KERN_ERR "jbd2_journal_dirty_metadata: %s: " | |
1332 | "bad jh for block %llu: " | |
1333 | "transaction (%p, %u), " | |
1334 | "jh->b_transaction (%p, %u), " | |
1335 | "jh->b_next_transaction (%p, %u), jlist %u\n", | |
9ea7a0df TT |
1336 | journal->j_devname, |
1337 | (unsigned long long) bh->b_blocknr, | |
66a4cb18 | 1338 | transaction, transaction->t_tid, |
9ea7a0df | 1339 | jh->b_transaction, |
66a4cb18 TT |
1340 | jh->b_transaction ? |
1341 | jh->b_transaction->t_tid : 0, | |
9ea7a0df TT |
1342 | jh->b_next_transaction, |
1343 | jh->b_next_transaction ? | |
1344 | jh->b_next_transaction->t_tid : 0, | |
66a4cb18 TT |
1345 | jh->b_jlist); |
1346 | WARN_ON(1); | |
9ea7a0df TT |
1347 | ret = -EINVAL; |
1348 | } | |
470decc6 DK |
1349 | /* And this case is illegal: we can't reuse another |
1350 | * transaction's data buffer, ever. */ | |
1351 | goto out_unlock_bh; | |
1352 | } | |
1353 | ||
1354 | /* That test should have eliminated the following case: */ | |
4019191b | 1355 | J_ASSERT_JH(jh, jh->b_frozen_data == NULL); |
470decc6 DK |
1356 | |
1357 | JBUFFER_TRACE(jh, "file as BJ_Metadata"); | |
1358 | spin_lock(&journal->j_list_lock); | |
41a5b913 | 1359 | __jbd2_journal_file_buffer(jh, transaction, BJ_Metadata); |
470decc6 DK |
1360 | spin_unlock(&journal->j_list_lock); |
1361 | out_unlock_bh: | |
1362 | jbd_unlock_bh_state(bh); | |
ad56edad | 1363 | jbd2_journal_put_journal_head(jh); |
470decc6 DK |
1364 | out: |
1365 | JBUFFER_TRACE(jh, "exit"); | |
9ea7a0df | 1366 | return ret; |
470decc6 DK |
1367 | } |
1368 | ||
470decc6 | 1369 | /** |
f7f4bccb | 1370 | * void jbd2_journal_forget() - bforget() for potentially-journaled buffers. |
470decc6 DK |
1371 | * @handle: transaction handle |
1372 | * @bh: bh to 'forget' | |
1373 | * | |
1374 | * We can only do the bforget if there are no commits pending against the | |
1375 | * buffer. If the buffer is dirty in the current running transaction we | |
1376 | * can safely unlink it. | |
1377 | * | |
1378 | * bh may not be a journalled buffer at all - it may be a non-JBD | |
1379 | * buffer which came off the hashtable. Check for this. | |
1380 | * | |
1381 | * Decrements bh->b_count by one. | |
1382 | * | |
1383 | * Allow this call even if the handle has aborted --- it may be part of | |
1384 | * the caller's cleanup after an abort. | |
1385 | */ | |
f7f4bccb | 1386 | int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh) |
470decc6 DK |
1387 | { |
1388 | transaction_t *transaction = handle->h_transaction; | |
41a5b913 | 1389 | journal_t *journal; |
470decc6 DK |
1390 | struct journal_head *jh; |
1391 | int drop_reserve = 0; | |
1392 | int err = 0; | |
1dfc3220 | 1393 | int was_modified = 0; |
470decc6 | 1394 | |
41a5b913 TT |
1395 | if (is_handle_aborted(handle)) |
1396 | return -EROFS; | |
1397 | journal = transaction->t_journal; | |
1398 | ||
470decc6 DK |
1399 | BUFFER_TRACE(bh, "entry"); |
1400 | ||
1401 | jbd_lock_bh_state(bh); | |
470decc6 DK |
1402 | |
1403 | if (!buffer_jbd(bh)) | |
1404 | goto not_jbd; | |
1405 | jh = bh2jh(bh); | |
1406 | ||
1407 | /* Critical error: attempting to delete a bitmap buffer, maybe? | |
1408 | * Don't do any jbd operations, and return an error. */ | |
1409 | if (!J_EXPECT_JH(jh, !jh->b_committed_data, | |
1410 | "inconsistent data on disk")) { | |
1411 | err = -EIO; | |
1412 | goto not_jbd; | |
1413 | } | |
1414 | ||
48fc7f7e | 1415 | /* keep track of whether or not this transaction modified us */ |
1dfc3220 JB |
1416 | was_modified = jh->b_modified; |
1417 | ||
470decc6 DK |
1418 | /* |
1419 | * The buffer's going from the transaction, we must drop | |
1420 | * all references -bzzz | |
1421 | */ | |
1422 | jh->b_modified = 0; | |
1423 | ||
41a5b913 | 1424 | if (jh->b_transaction == transaction) { |
470decc6 DK |
1425 | J_ASSERT_JH(jh, !jh->b_frozen_data); |
1426 | ||
1427 | /* If we are forgetting a buffer which is already part | |
1428 | * of this transaction, then we can just drop it from | |
1429 | * the transaction immediately. */ | |
1430 | clear_buffer_dirty(bh); | |
1431 | clear_buffer_jbddirty(bh); | |
1432 | ||
1433 | JBUFFER_TRACE(jh, "belongs to current transaction: unfile"); | |
1434 | ||
1dfc3220 JB |
1435 | /* |
1436 | * we only want to drop a reference if this transaction | |
1437 | * modified the buffer | |
1438 | */ | |
1439 | if (was_modified) | |
1440 | drop_reserve = 1; | |
470decc6 DK |
1441 | |
1442 | /* | |
1443 | * We are no longer going to journal this buffer. | |
1444 | * However, the commit of this transaction is still | |
1445 | * important to the buffer: the delete that we are now | |
1446 | * processing might obsolete an old log entry, so by | |
1447 | * committing, we can satisfy the buffer's checkpoint. | |
1448 | * | |
1449 | * So, if we have a checkpoint on the buffer, we should | |
1450 | * now refile the buffer on our BJ_Forget list so that | |
1451 | * we know to remove the checkpoint after we commit. | |
1452 | */ | |
1453 | ||
0bfea811 | 1454 | spin_lock(&journal->j_list_lock); |
470decc6 | 1455 | if (jh->b_cp_transaction) { |
f7f4bccb MC |
1456 | __jbd2_journal_temp_unlink_buffer(jh); |
1457 | __jbd2_journal_file_buffer(jh, transaction, BJ_Forget); | |
470decc6 | 1458 | } else { |
f7f4bccb | 1459 | __jbd2_journal_unfile_buffer(jh); |
470decc6 DK |
1460 | if (!buffer_jbd(bh)) { |
1461 | spin_unlock(&journal->j_list_lock); | |
1462 | jbd_unlock_bh_state(bh); | |
1463 | __bforget(bh); | |
1464 | goto drop; | |
1465 | } | |
1466 | } | |
0bfea811 | 1467 | spin_unlock(&journal->j_list_lock); |
470decc6 DK |
1468 | } else if (jh->b_transaction) { |
1469 | J_ASSERT_JH(jh, (jh->b_transaction == | |
1470 | journal->j_committing_transaction)); | |
1471 | /* However, if the buffer is still owned by a prior | |
1472 | * (committing) transaction, we can't drop it yet... */ | |
1473 | JBUFFER_TRACE(jh, "belongs to older transaction"); | |
1474 | /* ... but we CAN drop it from the new transaction if we | |
1475 | * have also modified it since the original commit. */ | |
1476 | ||
1477 | if (jh->b_next_transaction) { | |
1478 | J_ASSERT(jh->b_next_transaction == transaction); | |
0bfea811 | 1479 | spin_lock(&journal->j_list_lock); |
470decc6 | 1480 | jh->b_next_transaction = NULL; |
0bfea811 | 1481 | spin_unlock(&journal->j_list_lock); |
1dfc3220 JB |
1482 | |
1483 | /* | |
1484 | * only drop a reference if this transaction modified | |
1485 | * the buffer | |
1486 | */ | |
1487 | if (was_modified) | |
1488 | drop_reserve = 1; | |
470decc6 DK |
1489 | } |
1490 | } | |
1491 | ||
1492 | not_jbd: | |
470decc6 DK |
1493 | jbd_unlock_bh_state(bh); |
1494 | __brelse(bh); | |
1495 | drop: | |
1496 | if (drop_reserve) { | |
1497 | /* no need to reserve log space for this block -bzzz */ | |
1498 | handle->h_buffer_credits++; | |
1499 | } | |
1500 | return err; | |
1501 | } | |
1502 | ||
1503 | /** | |
f7f4bccb | 1504 | * int jbd2_journal_stop() - complete a transaction |
470decc6 DK |
1505 | * @handle: tranaction to complete. |
1506 | * | |
1507 | * All done for a particular handle. | |
1508 | * | |
1509 | * There is not much action needed here. We just return any remaining | |
1510 | * buffer credits to the transaction and remove the handle. The only | |
1511 | * complication is that we need to start a commit operation if the | |
1512 | * filesystem is marked for synchronous update. | |
1513 | * | |
f7f4bccb | 1514 | * jbd2_journal_stop itself will not usually return an error, but it may |
470decc6 | 1515 | * do so in unusual circumstances. In particular, expect it to |
f7f4bccb | 1516 | * return -EIO if a jbd2_journal_abort has been executed since the |
470decc6 DK |
1517 | * transaction began. |
1518 | */ | |
f7f4bccb | 1519 | int jbd2_journal_stop(handle_t *handle) |
470decc6 DK |
1520 | { |
1521 | transaction_t *transaction = handle->h_transaction; | |
41a5b913 TT |
1522 | journal_t *journal; |
1523 | int err = 0, wait_for_commit = 0; | |
a51dca9c | 1524 | tid_t tid; |
470decc6 DK |
1525 | pid_t pid; |
1526 | ||
9d506594 LC |
1527 | if (!transaction) { |
1528 | /* | |
1529 | * Handle is already detached from the transaction so | |
1530 | * there is nothing to do other than decrease a refcount, | |
1531 | * or free the handle if refcount drops to zero | |
1532 | */ | |
1533 | if (--handle->h_ref > 0) { | |
1534 | jbd_debug(4, "h_ref %d -> %d\n", handle->h_ref + 1, | |
1535 | handle->h_ref); | |
1536 | return err; | |
1537 | } else { | |
1538 | if (handle->h_rsv_handle) | |
1539 | jbd2_free_handle(handle->h_rsv_handle); | |
1540 | goto free_and_exit; | |
1541 | } | |
1542 | } | |
41a5b913 TT |
1543 | journal = transaction->t_journal; |
1544 | ||
470decc6 DK |
1545 | J_ASSERT(journal_current_handle() == handle); |
1546 | ||
1547 | if (is_handle_aborted(handle)) | |
1548 | err = -EIO; | |
41a5b913 | 1549 | else |
a51dca9c | 1550 | J_ASSERT(atomic_read(&transaction->t_updates) > 0); |
470decc6 DK |
1551 | |
1552 | if (--handle->h_ref > 0) { | |
1553 | jbd_debug(4, "h_ref %d -> %d\n", handle->h_ref + 1, | |
1554 | handle->h_ref); | |
1555 | return err; | |
1556 | } | |
1557 | ||
1558 | jbd_debug(4, "Handle %p going down\n", handle); | |
343d9c28 | 1559 | trace_jbd2_handle_stats(journal->j_fs_dev->bd_dev, |
41a5b913 | 1560 | transaction->t_tid, |
343d9c28 TT |
1561 | handle->h_type, handle->h_line_no, |
1562 | jiffies - handle->h_start_jiffies, | |
1563 | handle->h_sync, handle->h_requested_credits, | |
1564 | (handle->h_requested_credits - | |
1565 | handle->h_buffer_credits)); | |
470decc6 DK |
1566 | |
1567 | /* | |
1568 | * Implement synchronous transaction batching. If the handle | |
1569 | * was synchronous, don't force a commit immediately. Let's | |
e07f7183 JB |
1570 | * yield and let another thread piggyback onto this |
1571 | * transaction. Keep doing that while new threads continue to | |
1572 | * arrive. It doesn't cost much - we're about to run a commit | |
1573 | * and sleep on IO anyway. Speeds up many-threaded, many-dir | |
1574 | * operations by 30x or more... | |
1575 | * | |
1576 | * We try and optimize the sleep time against what the | |
1577 | * underlying disk can do, instead of having a static sleep | |
1578 | * time. This is useful for the case where our storage is so | |
1579 | * fast that it is more optimal to go ahead and force a flush | |
1580 | * and wait for the transaction to be committed than it is to | |
1581 | * wait for an arbitrary amount of time for new writers to | |
1582 | * join the transaction. We achieve this by measuring how | |
1583 | * long it takes to commit a transaction, and compare it with | |
1584 | * how long this transaction has been running, and if run time | |
1585 | * < commit time then we sleep for the delta and commit. This | |
1586 | * greatly helps super fast disks that would see slowdowns as | |
1587 | * more threads started doing fsyncs. | |
470decc6 | 1588 | * |
e07f7183 JB |
1589 | * But don't do this if this process was the most recent one |
1590 | * to perform a synchronous write. We do this to detect the | |
1591 | * case where a single process is doing a stream of sync | |
1592 | * writes. No point in waiting for joiners in that case. | |
5dd21424 ES |
1593 | * |
1594 | * Setting max_batch_time to 0 disables this completely. | |
470decc6 DK |
1595 | */ |
1596 | pid = current->pid; | |
5dd21424 ES |
1597 | if (handle->h_sync && journal->j_last_sync_writer != pid && |
1598 | journal->j_max_batch_time) { | |
e07f7183 JB |
1599 | u64 commit_time, trans_time; |
1600 | ||
470decc6 | 1601 | journal->j_last_sync_writer = pid; |
e07f7183 | 1602 | |
a931da6a | 1603 | read_lock(&journal->j_state_lock); |
e07f7183 | 1604 | commit_time = journal->j_average_commit_time; |
a931da6a | 1605 | read_unlock(&journal->j_state_lock); |
e07f7183 JB |
1606 | |
1607 | trans_time = ktime_to_ns(ktime_sub(ktime_get(), | |
1608 | transaction->t_start_time)); | |
1609 | ||
30773840 TT |
1610 | commit_time = max_t(u64, commit_time, |
1611 | 1000*journal->j_min_batch_time); | |
e07f7183 | 1612 | commit_time = min_t(u64, commit_time, |
30773840 | 1613 | 1000*journal->j_max_batch_time); |
e07f7183 JB |
1614 | |
1615 | if (trans_time < commit_time) { | |
1616 | ktime_t expires = ktime_add_ns(ktime_get(), | |
1617 | commit_time); | |
1618 | set_current_state(TASK_UNINTERRUPTIBLE); | |
1619 | schedule_hrtimeout(&expires, HRTIMER_MODE_ABS); | |
1620 | } | |
470decc6 DK |
1621 | } |
1622 | ||
7058548c TT |
1623 | if (handle->h_sync) |
1624 | transaction->t_synchronous_commit = 1; | |
470decc6 | 1625 | current->journal_info = NULL; |
a51dca9c TT |
1626 | atomic_sub(handle->h_buffer_credits, |
1627 | &transaction->t_outstanding_credits); | |
470decc6 DK |
1628 | |
1629 | /* | |
1630 | * If the handle is marked SYNC, we need to set another commit | |
1631 | * going! We also want to force a commit if the current | |
1632 | * transaction is occupying too much of the log, or if the | |
1633 | * transaction is too old now. | |
1634 | */ | |
1635 | if (handle->h_sync || | |
a51dca9c TT |
1636 | (atomic_read(&transaction->t_outstanding_credits) > |
1637 | journal->j_max_transaction_buffers) || | |
1638 | time_after_eq(jiffies, transaction->t_expires)) { | |
470decc6 DK |
1639 | /* Do this even for aborted journals: an abort still |
1640 | * completes the commit thread, it just doesn't write | |
1641 | * anything to disk. */ | |
470decc6 | 1642 | |
470decc6 DK |
1643 | jbd_debug(2, "transaction too old, requesting commit for " |
1644 | "handle %p\n", handle); | |
1645 | /* This is non-blocking */ | |
c35a56a0 | 1646 | jbd2_log_start_commit(journal, transaction->t_tid); |
470decc6 DK |
1647 | |
1648 | /* | |
f7f4bccb | 1649 | * Special case: JBD2_SYNC synchronous updates require us |
470decc6 DK |
1650 | * to wait for the commit to complete. |
1651 | */ | |
1652 | if (handle->h_sync && !(current->flags & PF_MEMALLOC)) | |
a51dca9c | 1653 | wait_for_commit = 1; |
470decc6 DK |
1654 | } |
1655 | ||
a51dca9c TT |
1656 | /* |
1657 | * Once we drop t_updates, if it goes to zero the transaction | |
25985edc | 1658 | * could start committing on us and eventually disappear. So |
a51dca9c TT |
1659 | * once we do this, we must not dereference transaction |
1660 | * pointer again. | |
1661 | */ | |
1662 | tid = transaction->t_tid; | |
1663 | if (atomic_dec_and_test(&transaction->t_updates)) { | |
1664 | wake_up(&journal->j_wait_updates); | |
1665 | if (journal->j_barrier_count) | |
1666 | wake_up(&journal->j_wait_transaction_locked); | |
1667 | } | |
1668 | ||
1669 | if (wait_for_commit) | |
1670 | err = jbd2_log_wait_commit(journal, tid); | |
1671 | ||
3295f0ef | 1672 | lock_map_release(&handle->h_lockdep_map); |
7b751066 | 1673 | |
8f7d89f3 JK |
1674 | if (handle->h_rsv_handle) |
1675 | jbd2_journal_free_reserved(handle->h_rsv_handle); | |
41a5b913 | 1676 | free_and_exit: |
af1e76d6 | 1677 | jbd2_free_handle(handle); |
470decc6 DK |
1678 | return err; |
1679 | } | |
1680 | ||
470decc6 DK |
1681 | /* |
1682 | * | |
1683 | * List management code snippets: various functions for manipulating the | |
1684 | * transaction buffer lists. | |
1685 | * | |
1686 | */ | |
1687 | ||
1688 | /* | |
1689 | * Append a buffer to a transaction list, given the transaction's list head | |
1690 | * pointer. | |
1691 | * | |
1692 | * j_list_lock is held. | |
1693 | * | |
1694 | * jbd_lock_bh_state(jh2bh(jh)) is held. | |
1695 | */ | |
1696 | ||
1697 | static inline void | |
1698 | __blist_add_buffer(struct journal_head **list, struct journal_head *jh) | |
1699 | { | |
1700 | if (!*list) { | |
1701 | jh->b_tnext = jh->b_tprev = jh; | |
1702 | *list = jh; | |
1703 | } else { | |
1704 | /* Insert at the tail of the list to preserve order */ | |
1705 | struct journal_head *first = *list, *last = first->b_tprev; | |
1706 | jh->b_tprev = last; | |
1707 | jh->b_tnext = first; | |
1708 | last->b_tnext = first->b_tprev = jh; | |
1709 | } | |
1710 | } | |
1711 | ||
1712 | /* | |
1713 | * Remove a buffer from a transaction list, given the transaction's list | |
1714 | * head pointer. | |
1715 | * | |
1716 | * Called with j_list_lock held, and the journal may not be locked. | |
1717 | * | |
1718 | * jbd_lock_bh_state(jh2bh(jh)) is held. | |
1719 | */ | |
1720 | ||
1721 | static inline void | |
1722 | __blist_del_buffer(struct journal_head **list, struct journal_head *jh) | |
1723 | { | |
1724 | if (*list == jh) { | |
1725 | *list = jh->b_tnext; | |
1726 | if (*list == jh) | |
1727 | *list = NULL; | |
1728 | } | |
1729 | jh->b_tprev->b_tnext = jh->b_tnext; | |
1730 | jh->b_tnext->b_tprev = jh->b_tprev; | |
1731 | } | |
1732 | ||
1733 | /* | |
1734 | * Remove a buffer from the appropriate transaction list. | |
1735 | * | |
1736 | * Note that this function can *change* the value of | |
f5113eff JK |
1737 | * bh->b_transaction->t_buffers, t_forget, t_shadow_list, t_log_list or |
1738 | * t_reserved_list. If the caller is holding onto a copy of one of these | |
1739 | * pointers, it could go bad. Generally the caller needs to re-read the | |
1740 | * pointer from the transaction_t. | |
470decc6 | 1741 | * |
5bebccf9 | 1742 | * Called under j_list_lock. |
470decc6 | 1743 | */ |
5bebccf9 | 1744 | static void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh) |
470decc6 DK |
1745 | { |
1746 | struct journal_head **list = NULL; | |
1747 | transaction_t *transaction; | |
1748 | struct buffer_head *bh = jh2bh(jh); | |
1749 | ||
1750 | J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh)); | |
1751 | transaction = jh->b_transaction; | |
1752 | if (transaction) | |
1753 | assert_spin_locked(&transaction->t_journal->j_list_lock); | |
1754 | ||
1755 | J_ASSERT_JH(jh, jh->b_jlist < BJ_Types); | |
1756 | if (jh->b_jlist != BJ_None) | |
4019191b | 1757 | J_ASSERT_JH(jh, transaction != NULL); |
470decc6 DK |
1758 | |
1759 | switch (jh->b_jlist) { | |
1760 | case BJ_None: | |
1761 | return; | |
470decc6 DK |
1762 | case BJ_Metadata: |
1763 | transaction->t_nr_buffers--; | |
1764 | J_ASSERT_JH(jh, transaction->t_nr_buffers >= 0); | |
1765 | list = &transaction->t_buffers; | |
1766 | break; | |
1767 | case BJ_Forget: | |
1768 | list = &transaction->t_forget; | |
1769 | break; | |
470decc6 DK |
1770 | case BJ_Shadow: |
1771 | list = &transaction->t_shadow_list; | |
1772 | break; | |
470decc6 DK |
1773 | case BJ_Reserved: |
1774 | list = &transaction->t_reserved_list; | |
1775 | break; | |
470decc6 DK |
1776 | } |
1777 | ||
1778 | __blist_del_buffer(list, jh); | |
1779 | jh->b_jlist = BJ_None; | |
1780 | if (test_clear_buffer_jbddirty(bh)) | |
1781 | mark_buffer_dirty(bh); /* Expose it to the VM */ | |
1782 | } | |
1783 | ||
de1b7941 JK |
1784 | /* |
1785 | * Remove buffer from all transactions. | |
1786 | * | |
1787 | * Called with bh_state lock and j_list_lock | |
1788 | * | |
1789 | * jh and bh may be already freed when this function returns. | |
1790 | */ | |
1791 | static void __jbd2_journal_unfile_buffer(struct journal_head *jh) | |
470decc6 | 1792 | { |
f7f4bccb | 1793 | __jbd2_journal_temp_unlink_buffer(jh); |
470decc6 | 1794 | jh->b_transaction = NULL; |
de1b7941 | 1795 | jbd2_journal_put_journal_head(jh); |
470decc6 DK |
1796 | } |
1797 | ||
f7f4bccb | 1798 | void jbd2_journal_unfile_buffer(journal_t *journal, struct journal_head *jh) |
470decc6 | 1799 | { |
de1b7941 JK |
1800 | struct buffer_head *bh = jh2bh(jh); |
1801 | ||
1802 | /* Get reference so that buffer cannot be freed before we unlock it */ | |
1803 | get_bh(bh); | |
1804 | jbd_lock_bh_state(bh); | |
470decc6 | 1805 | spin_lock(&journal->j_list_lock); |
f7f4bccb | 1806 | __jbd2_journal_unfile_buffer(jh); |
470decc6 | 1807 | spin_unlock(&journal->j_list_lock); |
de1b7941 JK |
1808 | jbd_unlock_bh_state(bh); |
1809 | __brelse(bh); | |
470decc6 DK |
1810 | } |
1811 | ||
1812 | /* | |
f7f4bccb | 1813 | * Called from jbd2_journal_try_to_free_buffers(). |
470decc6 DK |
1814 | * |
1815 | * Called under jbd_lock_bh_state(bh) | |
1816 | */ | |
1817 | static void | |
1818 | __journal_try_to_free_buffer(journal_t *journal, struct buffer_head *bh) | |
1819 | { | |
1820 | struct journal_head *jh; | |
1821 | ||
1822 | jh = bh2jh(bh); | |
1823 | ||
1824 | if (buffer_locked(bh) || buffer_dirty(bh)) | |
1825 | goto out; | |
1826 | ||
d2eb0b99 | 1827 | if (jh->b_next_transaction != NULL || jh->b_transaction != NULL) |
470decc6 DK |
1828 | goto out; |
1829 | ||
1830 | spin_lock(&journal->j_list_lock); | |
d2eb0b99 | 1831 | if (jh->b_cp_transaction != NULL) { |
470decc6 | 1832 | /* written-back checkpointed metadata buffer */ |
c254c9ec JK |
1833 | JBUFFER_TRACE(jh, "remove from checkpoint list"); |
1834 | __jbd2_journal_remove_checkpoint(jh); | |
470decc6 DK |
1835 | } |
1836 | spin_unlock(&journal->j_list_lock); | |
1837 | out: | |
1838 | return; | |
1839 | } | |
1840 | ||
470decc6 | 1841 | /** |
f7f4bccb | 1842 | * int jbd2_journal_try_to_free_buffers() - try to free page buffers. |
470decc6 DK |
1843 | * @journal: journal for operation |
1844 | * @page: to try and free | |
530576bb MC |
1845 | * @gfp_mask: we use the mask to detect how hard should we try to release |
1846 | * buffers. If __GFP_WAIT and __GFP_FS is set, we wait for commit code to | |
1847 | * release the buffers. | |
470decc6 DK |
1848 | * |
1849 | * | |
1850 | * For all the buffers on this page, | |
1851 | * if they are fully written out ordered data, move them onto BUF_CLEAN | |
1852 | * so try_to_free_buffers() can reap them. | |
1853 | * | |
1854 | * This function returns non-zero if we wish try_to_free_buffers() | |
1855 | * to be called. We do this if the page is releasable by try_to_free_buffers(). | |
1856 | * We also do it if the page has locked or dirty buffers and the caller wants | |
1857 | * us to perform sync or async writeout. | |
1858 | * | |
1859 | * This complicates JBD locking somewhat. We aren't protected by the | |
1860 | * BKL here. We wish to remove the buffer from its committing or | |
f7f4bccb | 1861 | * running transaction's ->t_datalist via __jbd2_journal_unfile_buffer. |
470decc6 DK |
1862 | * |
1863 | * This may *change* the value of transaction_t->t_datalist, so anyone | |
1864 | * who looks at t_datalist needs to lock against this function. | |
1865 | * | |
f7f4bccb MC |
1866 | * Even worse, someone may be doing a jbd2_journal_dirty_data on this |
1867 | * buffer. So we need to lock against that. jbd2_journal_dirty_data() | |
470decc6 DK |
1868 | * will come out of the lock with the buffer dirty, which makes it |
1869 | * ineligible for release here. | |
1870 | * | |
1871 | * Who else is affected by this? hmm... Really the only contender | |
1872 | * is do_get_write_access() - it could be looking at the buffer while | |
1873 | * journal_try_to_free_buffer() is changing its state. But that | |
1874 | * cannot happen because we never reallocate freed data as metadata | |
1875 | * while the data is part of a transaction. Yes? | |
530576bb MC |
1876 | * |
1877 | * Return 0 on failure, 1 on success | |
470decc6 | 1878 | */ |
f7f4bccb | 1879 | int jbd2_journal_try_to_free_buffers(journal_t *journal, |
530576bb | 1880 | struct page *page, gfp_t gfp_mask) |
470decc6 DK |
1881 | { |
1882 | struct buffer_head *head; | |
1883 | struct buffer_head *bh; | |
1884 | int ret = 0; | |
1885 | ||
1886 | J_ASSERT(PageLocked(page)); | |
1887 | ||
1888 | head = page_buffers(page); | |
1889 | bh = head; | |
1890 | do { | |
1891 | struct journal_head *jh; | |
1892 | ||
1893 | /* | |
1894 | * We take our own ref against the journal_head here to avoid | |
1895 | * having to add tons of locking around each instance of | |
530576bb | 1896 | * jbd2_journal_put_journal_head(). |
470decc6 | 1897 | */ |
f7f4bccb | 1898 | jh = jbd2_journal_grab_journal_head(bh); |
470decc6 DK |
1899 | if (!jh) |
1900 | continue; | |
1901 | ||
1902 | jbd_lock_bh_state(bh); | |
1903 | __journal_try_to_free_buffer(journal, bh); | |
f7f4bccb | 1904 | jbd2_journal_put_journal_head(jh); |
470decc6 DK |
1905 | jbd_unlock_bh_state(bh); |
1906 | if (buffer_jbd(bh)) | |
1907 | goto busy; | |
1908 | } while ((bh = bh->b_this_page) != head); | |
530576bb | 1909 | |
470decc6 | 1910 | ret = try_to_free_buffers(page); |
530576bb | 1911 | |
470decc6 DK |
1912 | busy: |
1913 | return ret; | |
1914 | } | |
1915 | ||
1916 | /* | |
1917 | * This buffer is no longer needed. If it is on an older transaction's | |
1918 | * checkpoint list we need to record it on this transaction's forget list | |
1919 | * to pin this buffer (and hence its checkpointing transaction) down until | |
1920 | * this transaction commits. If the buffer isn't on a checkpoint list, we | |
1921 | * release it. | |
1922 | * Returns non-zero if JBD no longer has an interest in the buffer. | |
1923 | * | |
1924 | * Called under j_list_lock. | |
1925 | * | |
1926 | * Called under jbd_lock_bh_state(bh). | |
1927 | */ | |
1928 | static int __dispose_buffer(struct journal_head *jh, transaction_t *transaction) | |
1929 | { | |
1930 | int may_free = 1; | |
1931 | struct buffer_head *bh = jh2bh(jh); | |
1932 | ||
470decc6 DK |
1933 | if (jh->b_cp_transaction) { |
1934 | JBUFFER_TRACE(jh, "on running+cp transaction"); | |
de1b7941 | 1935 | __jbd2_journal_temp_unlink_buffer(jh); |
f91d1d04 JK |
1936 | /* |
1937 | * We don't want to write the buffer anymore, clear the | |
1938 | * bit so that we don't confuse checks in | |
1939 | * __journal_file_buffer | |
1940 | */ | |
1941 | clear_buffer_dirty(bh); | |
f7f4bccb | 1942 | __jbd2_journal_file_buffer(jh, transaction, BJ_Forget); |
470decc6 DK |
1943 | may_free = 0; |
1944 | } else { | |
1945 | JBUFFER_TRACE(jh, "on running transaction"); | |
de1b7941 | 1946 | __jbd2_journal_unfile_buffer(jh); |
470decc6 DK |
1947 | } |
1948 | return may_free; | |
1949 | } | |
1950 | ||
1951 | /* | |
f7f4bccb | 1952 | * jbd2_journal_invalidatepage |
470decc6 DK |
1953 | * |
1954 | * This code is tricky. It has a number of cases to deal with. | |
1955 | * | |
1956 | * There are two invariants which this code relies on: | |
1957 | * | |
1958 | * i_size must be updated on disk before we start calling invalidatepage on the | |
1959 | * data. | |
1960 | * | |
1961 | * This is done in ext3 by defining an ext3_setattr method which | |
1962 | * updates i_size before truncate gets going. By maintaining this | |
1963 | * invariant, we can be sure that it is safe to throw away any buffers | |
1964 | * attached to the current transaction: once the transaction commits, | |
1965 | * we know that the data will not be needed. | |
1966 | * | |
1967 | * Note however that we can *not* throw away data belonging to the | |
1968 | * previous, committing transaction! | |
1969 | * | |
1970 | * Any disk blocks which *are* part of the previous, committing | |
1971 | * transaction (and which therefore cannot be discarded immediately) are | |
1972 | * not going to be reused in the new running transaction | |
1973 | * | |
1974 | * The bitmap committed_data images guarantee this: any block which is | |
1975 | * allocated in one transaction and removed in the next will be marked | |
1976 | * as in-use in the committed_data bitmap, so cannot be reused until | |
1977 | * the next transaction to delete the block commits. This means that | |
1978 | * leaving committing buffers dirty is quite safe: the disk blocks | |
1979 | * cannot be reallocated to a different file and so buffer aliasing is | |
1980 | * not possible. | |
1981 | * | |
1982 | * | |
1983 | * The above applies mainly to ordered data mode. In writeback mode we | |
1984 | * don't make guarantees about the order in which data hits disk --- in | |
1985 | * particular we don't guarantee that new dirty data is flushed before | |
1986 | * transaction commit --- so it is always safe just to discard data | |
1987 | * immediately in that mode. --sct | |
1988 | */ | |
1989 | ||
1990 | /* | |
1991 | * The journal_unmap_buffer helper function returns zero if the buffer | |
1992 | * concerned remains pinned as an anonymous buffer belonging to an older | |
1993 | * transaction. | |
1994 | * | |
1995 | * We're outside-transaction here. Either or both of j_running_transaction | |
1996 | * and j_committing_transaction may be NULL. | |
1997 | */ | |
b794e7a6 JK |
1998 | static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh, |
1999 | int partial_page) | |
470decc6 DK |
2000 | { |
2001 | transaction_t *transaction; | |
2002 | struct journal_head *jh; | |
2003 | int may_free = 1; | |
470decc6 DK |
2004 | |
2005 | BUFFER_TRACE(bh, "entry"); | |
2006 | ||
2007 | /* | |
2008 | * It is safe to proceed here without the j_list_lock because the | |
2009 | * buffers cannot be stolen by try_to_free_buffers as long as we are | |
2010 | * holding the page lock. --sct | |
2011 | */ | |
2012 | ||
2013 | if (!buffer_jbd(bh)) | |
2014 | goto zap_buffer_unlocked; | |
2015 | ||
87c89c23 | 2016 | /* OK, we have data buffer in journaled mode */ |
a931da6a | 2017 | write_lock(&journal->j_state_lock); |
470decc6 DK |
2018 | jbd_lock_bh_state(bh); |
2019 | spin_lock(&journal->j_list_lock); | |
2020 | ||
f7f4bccb | 2021 | jh = jbd2_journal_grab_journal_head(bh); |
470decc6 DK |
2022 | if (!jh) |
2023 | goto zap_buffer_no_jh; | |
2024 | ||
ba869023 | 2025 | /* |
2026 | * We cannot remove the buffer from checkpoint lists until the | |
2027 | * transaction adding inode to orphan list (let's call it T) | |
2028 | * is committed. Otherwise if the transaction changing the | |
2029 | * buffer would be cleaned from the journal before T is | |
2030 | * committed, a crash will cause that the correct contents of | |
2031 | * the buffer will be lost. On the other hand we have to | |
2032 | * clear the buffer dirty bit at latest at the moment when the | |
2033 | * transaction marking the buffer as freed in the filesystem | |
2034 | * structures is committed because from that moment on the | |
b794e7a6 | 2035 | * block can be reallocated and used by a different page. |
ba869023 | 2036 | * Since the block hasn't been freed yet but the inode has |
2037 | * already been added to orphan list, it is safe for us to add | |
2038 | * the buffer to BJ_Forget list of the newest transaction. | |
b794e7a6 JK |
2039 | * |
2040 | * Also we have to clear buffer_mapped flag of a truncated buffer | |
2041 | * because the buffer_head may be attached to the page straddling | |
2042 | * i_size (can happen only when blocksize < pagesize) and thus the | |
2043 | * buffer_head can be reused when the file is extended again. So we end | |
2044 | * up keeping around invalidated buffers attached to transactions' | |
2045 | * BJ_Forget list just to stop checkpointing code from cleaning up | |
2046 | * the transaction this buffer was modified in. | |
ba869023 | 2047 | */ |
470decc6 DK |
2048 | transaction = jh->b_transaction; |
2049 | if (transaction == NULL) { | |
2050 | /* First case: not on any transaction. If it | |
2051 | * has no checkpoint link, then we can zap it: | |
2052 | * it's a writeback-mode buffer so we don't care | |
2053 | * if it hits disk safely. */ | |
2054 | if (!jh->b_cp_transaction) { | |
2055 | JBUFFER_TRACE(jh, "not on any transaction: zap"); | |
2056 | goto zap_buffer; | |
2057 | } | |
2058 | ||
2059 | if (!buffer_dirty(bh)) { | |
2060 | /* bdflush has written it. We can drop it now */ | |
2061 | goto zap_buffer; | |
2062 | } | |
2063 | ||
2064 | /* OK, it must be in the journal but still not | |
2065 | * written fully to disk: it's metadata or | |
2066 | * journaled data... */ | |
2067 | ||
2068 | if (journal->j_running_transaction) { | |
2069 | /* ... and once the current transaction has | |
2070 | * committed, the buffer won't be needed any | |
2071 | * longer. */ | |
2072 | JBUFFER_TRACE(jh, "checkpointed: add to BJ_Forget"); | |
b794e7a6 | 2073 | may_free = __dispose_buffer(jh, |
470decc6 | 2074 | journal->j_running_transaction); |
b794e7a6 | 2075 | goto zap_buffer; |
470decc6 DK |
2076 | } else { |
2077 | /* There is no currently-running transaction. So the | |
2078 | * orphan record which we wrote for this file must have | |
2079 | * passed into commit. We must attach this buffer to | |
2080 | * the committing transaction, if it exists. */ | |
2081 | if (journal->j_committing_transaction) { | |
2082 | JBUFFER_TRACE(jh, "give to committing trans"); | |
b794e7a6 | 2083 | may_free = __dispose_buffer(jh, |
470decc6 | 2084 | journal->j_committing_transaction); |
b794e7a6 | 2085 | goto zap_buffer; |
470decc6 DK |
2086 | } else { |
2087 | /* The orphan record's transaction has | |
2088 | * committed. We can cleanse this buffer */ | |
2089 | clear_buffer_jbddirty(bh); | |
2090 | goto zap_buffer; | |
2091 | } | |
2092 | } | |
2093 | } else if (transaction == journal->j_committing_transaction) { | |
9b57988d | 2094 | JBUFFER_TRACE(jh, "on committing transaction"); |
470decc6 | 2095 | /* |
ba869023 | 2096 | * The buffer is committing, we simply cannot touch |
b794e7a6 JK |
2097 | * it. If the page is straddling i_size we have to wait |
2098 | * for commit and try again. | |
2099 | */ | |
2100 | if (partial_page) { | |
b794e7a6 JK |
2101 | jbd2_journal_put_journal_head(jh); |
2102 | spin_unlock(&journal->j_list_lock); | |
2103 | jbd_unlock_bh_state(bh); | |
2104 | write_unlock(&journal->j_state_lock); | |
53e87268 | 2105 | return -EBUSY; |
b794e7a6 JK |
2106 | } |
2107 | /* | |
2108 | * OK, buffer won't be reachable after truncate. We just set | |
2109 | * j_next_transaction to the running transaction (if there is | |
2110 | * one) and mark buffer as freed so that commit code knows it | |
2111 | * should clear dirty bits when it is done with the buffer. | |
ba869023 | 2112 | */ |
470decc6 | 2113 | set_buffer_freed(bh); |
ba869023 | 2114 | if (journal->j_running_transaction && buffer_jbddirty(bh)) |
2115 | jh->b_next_transaction = journal->j_running_transaction; | |
f7f4bccb | 2116 | jbd2_journal_put_journal_head(jh); |
470decc6 DK |
2117 | spin_unlock(&journal->j_list_lock); |
2118 | jbd_unlock_bh_state(bh); | |
a931da6a | 2119 | write_unlock(&journal->j_state_lock); |
470decc6 DK |
2120 | return 0; |
2121 | } else { | |
2122 | /* Good, the buffer belongs to the running transaction. | |
2123 | * We are writing our own transaction's data, not any | |
2124 | * previous one's, so it is safe to throw it away | |
2125 | * (remember that we expect the filesystem to have set | |
2126 | * i_size already for this truncate so recovery will not | |
2127 | * expose the disk blocks we are discarding here.) */ | |
2128 | J_ASSERT_JH(jh, transaction == journal->j_running_transaction); | |
9b57988d | 2129 | JBUFFER_TRACE(jh, "on running transaction"); |
470decc6 DK |
2130 | may_free = __dispose_buffer(jh, transaction); |
2131 | } | |
2132 | ||
2133 | zap_buffer: | |
b794e7a6 JK |
2134 | /* |
2135 | * This is tricky. Although the buffer is truncated, it may be reused | |
2136 | * if blocksize < pagesize and it is attached to the page straddling | |
2137 | * EOF. Since the buffer might have been added to BJ_Forget list of the | |
2138 | * running transaction, journal_get_write_access() won't clear | |
2139 | * b_modified and credit accounting gets confused. So clear b_modified | |
2140 | * here. | |
2141 | */ | |
2142 | jh->b_modified = 0; | |
f7f4bccb | 2143 | jbd2_journal_put_journal_head(jh); |
470decc6 DK |
2144 | zap_buffer_no_jh: |
2145 | spin_unlock(&journal->j_list_lock); | |
2146 | jbd_unlock_bh_state(bh); | |
a931da6a | 2147 | write_unlock(&journal->j_state_lock); |
470decc6 DK |
2148 | zap_buffer_unlocked: |
2149 | clear_buffer_dirty(bh); | |
2150 | J_ASSERT_BH(bh, !buffer_jbddirty(bh)); | |
2151 | clear_buffer_mapped(bh); | |
2152 | clear_buffer_req(bh); | |
2153 | clear_buffer_new(bh); | |
15291164 ES |
2154 | clear_buffer_delay(bh); |
2155 | clear_buffer_unwritten(bh); | |
470decc6 DK |
2156 | bh->b_bdev = NULL; |
2157 | return may_free; | |
2158 | } | |
2159 | ||
2160 | /** | |
f7f4bccb | 2161 | * void jbd2_journal_invalidatepage() |
470decc6 DK |
2162 | * @journal: journal to use for flush... |
2163 | * @page: page to flush | |
259709b0 LC |
2164 | * @offset: start of the range to invalidate |
2165 | * @length: length of the range to invalidate | |
470decc6 | 2166 | * |
259709b0 LC |
2167 | * Reap page buffers containing data after in the specified range in page. |
2168 | * Can return -EBUSY if buffers are part of the committing transaction and | |
2169 | * the page is straddling i_size. Caller then has to wait for current commit | |
2170 | * and try again. | |
470decc6 | 2171 | */ |
53e87268 JK |
2172 | int jbd2_journal_invalidatepage(journal_t *journal, |
2173 | struct page *page, | |
259709b0 LC |
2174 | unsigned int offset, |
2175 | unsigned int length) | |
470decc6 DK |
2176 | { |
2177 | struct buffer_head *head, *bh, *next; | |
259709b0 | 2178 | unsigned int stop = offset + length; |
470decc6 | 2179 | unsigned int curr_off = 0; |
259709b0 | 2180 | int partial_page = (offset || length < PAGE_CACHE_SIZE); |
470decc6 | 2181 | int may_free = 1; |
53e87268 | 2182 | int ret = 0; |
470decc6 DK |
2183 | |
2184 | if (!PageLocked(page)) | |
2185 | BUG(); | |
2186 | if (!page_has_buffers(page)) | |
53e87268 | 2187 | return 0; |
470decc6 | 2188 | |
259709b0 LC |
2189 | BUG_ON(stop > PAGE_CACHE_SIZE || stop < length); |
2190 | ||
470decc6 DK |
2191 | /* We will potentially be playing with lists other than just the |
2192 | * data lists (especially for journaled data mode), so be | |
2193 | * cautious in our locking. */ | |
2194 | ||
2195 | head = bh = page_buffers(page); | |
2196 | do { | |
2197 | unsigned int next_off = curr_off + bh->b_size; | |
2198 | next = bh->b_this_page; | |
2199 | ||
259709b0 LC |
2200 | if (next_off > stop) |
2201 | return 0; | |
2202 | ||
470decc6 DK |
2203 | if (offset <= curr_off) { |
2204 | /* This block is wholly outside the truncation point */ | |
2205 | lock_buffer(bh); | |
259709b0 | 2206 | ret = journal_unmap_buffer(journal, bh, partial_page); |
470decc6 | 2207 | unlock_buffer(bh); |
53e87268 JK |
2208 | if (ret < 0) |
2209 | return ret; | |
2210 | may_free &= ret; | |
470decc6 DK |
2211 | } |
2212 | curr_off = next_off; | |
2213 | bh = next; | |
2214 | ||
2215 | } while (bh != head); | |
2216 | ||
259709b0 | 2217 | if (!partial_page) { |
470decc6 DK |
2218 | if (may_free && try_to_free_buffers(page)) |
2219 | J_ASSERT(!page_has_buffers(page)); | |
2220 | } | |
53e87268 | 2221 | return 0; |
470decc6 DK |
2222 | } |
2223 | ||
2224 | /* | |
2225 | * File a buffer on the given transaction list. | |
2226 | */ | |
f7f4bccb | 2227 | void __jbd2_journal_file_buffer(struct journal_head *jh, |
470decc6 DK |
2228 | transaction_t *transaction, int jlist) |
2229 | { | |
2230 | struct journal_head **list = NULL; | |
2231 | int was_dirty = 0; | |
2232 | struct buffer_head *bh = jh2bh(jh); | |
2233 | ||
2234 | J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh)); | |
2235 | assert_spin_locked(&transaction->t_journal->j_list_lock); | |
2236 | ||
2237 | J_ASSERT_JH(jh, jh->b_jlist < BJ_Types); | |
2238 | J_ASSERT_JH(jh, jh->b_transaction == transaction || | |
4019191b | 2239 | jh->b_transaction == NULL); |
470decc6 DK |
2240 | |
2241 | if (jh->b_transaction && jh->b_jlist == jlist) | |
2242 | return; | |
2243 | ||
470decc6 DK |
2244 | if (jlist == BJ_Metadata || jlist == BJ_Reserved || |
2245 | jlist == BJ_Shadow || jlist == BJ_Forget) { | |
f91d1d04 JK |
2246 | /* |
2247 | * For metadata buffers, we track dirty bit in buffer_jbddirty | |
2248 | * instead of buffer_dirty. We should not see a dirty bit set | |
2249 | * here because we clear it in do_get_write_access but e.g. | |
2250 | * tune2fs can modify the sb and set the dirty bit at any time | |
2251 | * so we try to gracefully handle that. | |
2252 | */ | |
2253 | if (buffer_dirty(bh)) | |
2254 | warn_dirty_buffer(bh); | |
470decc6 DK |
2255 | if (test_clear_buffer_dirty(bh) || |
2256 | test_clear_buffer_jbddirty(bh)) | |
2257 | was_dirty = 1; | |
2258 | } | |
2259 | ||
2260 | if (jh->b_transaction) | |
f7f4bccb | 2261 | __jbd2_journal_temp_unlink_buffer(jh); |
de1b7941 JK |
2262 | else |
2263 | jbd2_journal_grab_journal_head(bh); | |
470decc6 DK |
2264 | jh->b_transaction = transaction; |
2265 | ||
2266 | switch (jlist) { | |
2267 | case BJ_None: | |
2268 | J_ASSERT_JH(jh, !jh->b_committed_data); | |
2269 | J_ASSERT_JH(jh, !jh->b_frozen_data); | |
2270 | return; | |
470decc6 DK |
2271 | case BJ_Metadata: |
2272 | transaction->t_nr_buffers++; | |
2273 | list = &transaction->t_buffers; | |
2274 | break; | |
2275 | case BJ_Forget: | |
2276 | list = &transaction->t_forget; | |
2277 | break; | |
470decc6 DK |
2278 | case BJ_Shadow: |
2279 | list = &transaction->t_shadow_list; | |
2280 | break; | |
470decc6 DK |
2281 | case BJ_Reserved: |
2282 | list = &transaction->t_reserved_list; | |
2283 | break; | |
470decc6 DK |
2284 | } |
2285 | ||
2286 | __blist_add_buffer(list, jh); | |
2287 | jh->b_jlist = jlist; | |
2288 | ||
2289 | if (was_dirty) | |
2290 | set_buffer_jbddirty(bh); | |
2291 | } | |
2292 | ||
f7f4bccb | 2293 | void jbd2_journal_file_buffer(struct journal_head *jh, |
470decc6 DK |
2294 | transaction_t *transaction, int jlist) |
2295 | { | |
2296 | jbd_lock_bh_state(jh2bh(jh)); | |
2297 | spin_lock(&transaction->t_journal->j_list_lock); | |
f7f4bccb | 2298 | __jbd2_journal_file_buffer(jh, transaction, jlist); |
470decc6 DK |
2299 | spin_unlock(&transaction->t_journal->j_list_lock); |
2300 | jbd_unlock_bh_state(jh2bh(jh)); | |
2301 | } | |
2302 | ||
2303 | /* | |
2304 | * Remove a buffer from its current buffer list in preparation for | |
2305 | * dropping it from its current transaction entirely. If the buffer has | |
2306 | * already started to be used by a subsequent transaction, refile the | |
2307 | * buffer on that transaction's metadata list. | |
2308 | * | |
de1b7941 | 2309 | * Called under j_list_lock |
470decc6 | 2310 | * Called under jbd_lock_bh_state(jh2bh(jh)) |
de1b7941 JK |
2311 | * |
2312 | * jh and bh may be already free when this function returns | |
470decc6 | 2313 | */ |
f7f4bccb | 2314 | void __jbd2_journal_refile_buffer(struct journal_head *jh) |
470decc6 | 2315 | { |
ba869023 | 2316 | int was_dirty, jlist; |
470decc6 DK |
2317 | struct buffer_head *bh = jh2bh(jh); |
2318 | ||
2319 | J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh)); | |
2320 | if (jh->b_transaction) | |
2321 | assert_spin_locked(&jh->b_transaction->t_journal->j_list_lock); | |
2322 | ||
2323 | /* If the buffer is now unused, just drop it. */ | |
2324 | if (jh->b_next_transaction == NULL) { | |
f7f4bccb | 2325 | __jbd2_journal_unfile_buffer(jh); |
470decc6 DK |
2326 | return; |
2327 | } | |
2328 | ||
2329 | /* | |
2330 | * It has been modified by a later transaction: add it to the new | |
2331 | * transaction's metadata list. | |
2332 | */ | |
2333 | ||
2334 | was_dirty = test_clear_buffer_jbddirty(bh); | |
f7f4bccb | 2335 | __jbd2_journal_temp_unlink_buffer(jh); |
de1b7941 JK |
2336 | /* |
2337 | * We set b_transaction here because b_next_transaction will inherit | |
2338 | * our jh reference and thus __jbd2_journal_file_buffer() must not | |
2339 | * take a new one. | |
2340 | */ | |
470decc6 DK |
2341 | jh->b_transaction = jh->b_next_transaction; |
2342 | jh->b_next_transaction = NULL; | |
ba869023 | 2343 | if (buffer_freed(bh)) |
2344 | jlist = BJ_Forget; | |
2345 | else if (jh->b_modified) | |
2346 | jlist = BJ_Metadata; | |
2347 | else | |
2348 | jlist = BJ_Reserved; | |
2349 | __jbd2_journal_file_buffer(jh, jh->b_transaction, jlist); | |
470decc6 DK |
2350 | J_ASSERT_JH(jh, jh->b_transaction->t_state == T_RUNNING); |
2351 | ||
2352 | if (was_dirty) | |
2353 | set_buffer_jbddirty(bh); | |
2354 | } | |
2355 | ||
2356 | /* | |
de1b7941 JK |
2357 | * __jbd2_journal_refile_buffer() with necessary locking added. We take our |
2358 | * bh reference so that we can safely unlock bh. | |
2359 | * | |
2360 | * The jh and bh may be freed by this call. | |
470decc6 | 2361 | */ |
f7f4bccb | 2362 | void jbd2_journal_refile_buffer(journal_t *journal, struct journal_head *jh) |
470decc6 DK |
2363 | { |
2364 | struct buffer_head *bh = jh2bh(jh); | |
2365 | ||
de1b7941 JK |
2366 | /* Get reference so that buffer cannot be freed before we unlock it */ |
2367 | get_bh(bh); | |
470decc6 DK |
2368 | jbd_lock_bh_state(bh); |
2369 | spin_lock(&journal->j_list_lock); | |
f7f4bccb | 2370 | __jbd2_journal_refile_buffer(jh); |
470decc6 | 2371 | jbd_unlock_bh_state(bh); |
470decc6 DK |
2372 | spin_unlock(&journal->j_list_lock); |
2373 | __brelse(bh); | |
2374 | } | |
c851ed54 JK |
2375 | |
2376 | /* | |
2377 | * File inode in the inode list of the handle's transaction | |
2378 | */ | |
2379 | int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *jinode) | |
2380 | { | |
2381 | transaction_t *transaction = handle->h_transaction; | |
41a5b913 | 2382 | journal_t *journal; |
c851ed54 JK |
2383 | |
2384 | if (is_handle_aborted(handle)) | |
41a5b913 TT |
2385 | return -EROFS; |
2386 | journal = transaction->t_journal; | |
c851ed54 JK |
2387 | |
2388 | jbd_debug(4, "Adding inode %lu, tid:%d\n", jinode->i_vfs_inode->i_ino, | |
2389 | transaction->t_tid); | |
2390 | ||
2391 | /* | |
2392 | * First check whether inode isn't already on the transaction's | |
2393 | * lists without taking the lock. Note that this check is safe | |
2394 | * without the lock as we cannot race with somebody removing inode | |
2395 | * from the transaction. The reason is that we remove inode from the | |
2396 | * transaction only in journal_release_jbd_inode() and when we commit | |
2397 | * the transaction. We are guarded from the first case by holding | |
2398 | * a reference to the inode. We are safe against the second case | |
2399 | * because if jinode->i_transaction == transaction, commit code | |
2400 | * cannot touch the transaction because we hold reference to it, | |
2401 | * and if jinode->i_next_transaction == transaction, commit code | |
2402 | * will only file the inode where we want it. | |
2403 | */ | |
2404 | if (jinode->i_transaction == transaction || | |
2405 | jinode->i_next_transaction == transaction) | |
2406 | return 0; | |
2407 | ||
2408 | spin_lock(&journal->j_list_lock); | |
2409 | ||
2410 | if (jinode->i_transaction == transaction || | |
2411 | jinode->i_next_transaction == transaction) | |
2412 | goto done; | |
2413 | ||
81be12c8 JK |
2414 | /* |
2415 | * We only ever set this variable to 1 so the test is safe. Since | |
2416 | * t_need_data_flush is likely to be set, we do the test to save some | |
2417 | * cacheline bouncing | |
2418 | */ | |
2419 | if (!transaction->t_need_data_flush) | |
2420 | transaction->t_need_data_flush = 1; | |
c851ed54 JK |
2421 | /* On some different transaction's list - should be |
2422 | * the committing one */ | |
2423 | if (jinode->i_transaction) { | |
2424 | J_ASSERT(jinode->i_next_transaction == NULL); | |
2425 | J_ASSERT(jinode->i_transaction == | |
2426 | journal->j_committing_transaction); | |
2427 | jinode->i_next_transaction = transaction; | |
2428 | goto done; | |
2429 | } | |
2430 | /* Not on any transaction list... */ | |
2431 | J_ASSERT(!jinode->i_next_transaction); | |
2432 | jinode->i_transaction = transaction; | |
2433 | list_add(&jinode->i_list, &transaction->t_inode_list); | |
2434 | done: | |
2435 | spin_unlock(&journal->j_list_lock); | |
2436 | ||
2437 | return 0; | |
2438 | } | |
2439 | ||
2440 | /* | |
7f5aa215 JK |
2441 | * File truncate and transaction commit interact with each other in a |
2442 | * non-trivial way. If a transaction writing data block A is | |
2443 | * committing, we cannot discard the data by truncate until we have | |
2444 | * written them. Otherwise if we crashed after the transaction with | |
2445 | * write has committed but before the transaction with truncate has | |
2446 | * committed, we could see stale data in block A. This function is a | |
2447 | * helper to solve this problem. It starts writeout of the truncated | |
2448 | * part in case it is in the committing transaction. | |
2449 | * | |
2450 | * Filesystem code must call this function when inode is journaled in | |
2451 | * ordered mode before truncation happens and after the inode has been | |
2452 | * placed on orphan list with the new inode size. The second condition | |
2453 | * avoids the race that someone writes new data and we start | |
2454 | * committing the transaction after this function has been called but | |
2455 | * before a transaction for truncate is started (and furthermore it | |
2456 | * allows us to optimize the case where the addition to orphan list | |
2457 | * happens in the same transaction as write --- we don't have to write | |
2458 | * any data in such case). | |
c851ed54 | 2459 | */ |
7f5aa215 JK |
2460 | int jbd2_journal_begin_ordered_truncate(journal_t *journal, |
2461 | struct jbd2_inode *jinode, | |
c851ed54 JK |
2462 | loff_t new_size) |
2463 | { | |
7f5aa215 | 2464 | transaction_t *inode_trans, *commit_trans; |
c851ed54 JK |
2465 | int ret = 0; |
2466 | ||
7f5aa215 JK |
2467 | /* This is a quick check to avoid locking if not necessary */ |
2468 | if (!jinode->i_transaction) | |
c851ed54 | 2469 | goto out; |
7f5aa215 JK |
2470 | /* Locks are here just to force reading of recent values, it is |
2471 | * enough that the transaction was not committing before we started | |
2472 | * a transaction adding the inode to orphan list */ | |
a931da6a | 2473 | read_lock(&journal->j_state_lock); |
c851ed54 | 2474 | commit_trans = journal->j_committing_transaction; |
a931da6a | 2475 | read_unlock(&journal->j_state_lock); |
7f5aa215 JK |
2476 | spin_lock(&journal->j_list_lock); |
2477 | inode_trans = jinode->i_transaction; | |
2478 | spin_unlock(&journal->j_list_lock); | |
2479 | if (inode_trans == commit_trans) { | |
2480 | ret = filemap_fdatawrite_range(jinode->i_vfs_inode->i_mapping, | |
c851ed54 JK |
2481 | new_size, LLONG_MAX); |
2482 | if (ret) | |
2483 | jbd2_journal_abort(journal, ret); | |
2484 | } | |
2485 | out: | |
2486 | return ret; | |
2487 | } |