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470decc6 | 1 | /* |
f7f4bccb | 2 | * linux/fs/jbd2/journal.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 journal-writing code; part of the ext2fs | |
13 | * journaling system. | |
14 | * | |
15 | * This file manages journals: areas of disk reserved for logging | |
16 | * transactional updates. This includes the kernel journaling thread | |
17 | * which is responsible for scheduling updates to the log. | |
18 | * | |
19 | * We do not actually manage the physical storage of the journal in this | |
20 | * file: that is left to a per-journal policy function, which allows us | |
21 | * to store the journal within a filesystem-specified area for ext2 | |
22 | * journaling (ext2 can use a reserved inode for storing the log). | |
23 | */ | |
24 | ||
25 | #include <linux/module.h> | |
26 | #include <linux/time.h> | |
27 | #include <linux/fs.h> | |
f7f4bccb | 28 | #include <linux/jbd2.h> |
470decc6 DK |
29 | #include <linux/errno.h> |
30 | #include <linux/slab.h> | |
470decc6 DK |
31 | #include <linux/init.h> |
32 | #include <linux/mm.h> | |
7dfb7103 | 33 | #include <linux/freezer.h> |
470decc6 DK |
34 | #include <linux/pagemap.h> |
35 | #include <linux/kthread.h> | |
36 | #include <linux/poison.h> | |
37 | #include <linux/proc_fs.h> | |
0f49d5d0 | 38 | #include <linux/debugfs.h> |
8e85fb3f | 39 | #include <linux/seq_file.h> |
470decc6 DK |
40 | |
41 | #include <asm/uaccess.h> | |
42 | #include <asm/page.h> | |
d7cfa468 | 43 | #include <asm/div64.h> |
470decc6 | 44 | |
f7f4bccb MC |
45 | EXPORT_SYMBOL(jbd2_journal_start); |
46 | EXPORT_SYMBOL(jbd2_journal_restart); | |
47 | EXPORT_SYMBOL(jbd2_journal_extend); | |
48 | EXPORT_SYMBOL(jbd2_journal_stop); | |
49 | EXPORT_SYMBOL(jbd2_journal_lock_updates); | |
50 | EXPORT_SYMBOL(jbd2_journal_unlock_updates); | |
51 | EXPORT_SYMBOL(jbd2_journal_get_write_access); | |
52 | EXPORT_SYMBOL(jbd2_journal_get_create_access); | |
53 | EXPORT_SYMBOL(jbd2_journal_get_undo_access); | |
e06c8227 | 54 | EXPORT_SYMBOL(jbd2_journal_set_triggers); |
f7f4bccb MC |
55 | EXPORT_SYMBOL(jbd2_journal_dirty_metadata); |
56 | EXPORT_SYMBOL(jbd2_journal_release_buffer); | |
57 | EXPORT_SYMBOL(jbd2_journal_forget); | |
470decc6 DK |
58 | #if 0 |
59 | EXPORT_SYMBOL(journal_sync_buffer); | |
60 | #endif | |
f7f4bccb MC |
61 | EXPORT_SYMBOL(jbd2_journal_flush); |
62 | EXPORT_SYMBOL(jbd2_journal_revoke); | |
63 | ||
64 | EXPORT_SYMBOL(jbd2_journal_init_dev); | |
65 | EXPORT_SYMBOL(jbd2_journal_init_inode); | |
66 | EXPORT_SYMBOL(jbd2_journal_update_format); | |
67 | EXPORT_SYMBOL(jbd2_journal_check_used_features); | |
68 | EXPORT_SYMBOL(jbd2_journal_check_available_features); | |
69 | EXPORT_SYMBOL(jbd2_journal_set_features); | |
f7f4bccb MC |
70 | EXPORT_SYMBOL(jbd2_journal_load); |
71 | EXPORT_SYMBOL(jbd2_journal_destroy); | |
f7f4bccb MC |
72 | EXPORT_SYMBOL(jbd2_journal_abort); |
73 | EXPORT_SYMBOL(jbd2_journal_errno); | |
74 | EXPORT_SYMBOL(jbd2_journal_ack_err); | |
75 | EXPORT_SYMBOL(jbd2_journal_clear_err); | |
76 | EXPORT_SYMBOL(jbd2_log_wait_commit); | |
77 | EXPORT_SYMBOL(jbd2_journal_start_commit); | |
78 | EXPORT_SYMBOL(jbd2_journal_force_commit_nested); | |
79 | EXPORT_SYMBOL(jbd2_journal_wipe); | |
80 | EXPORT_SYMBOL(jbd2_journal_blocks_per_page); | |
81 | EXPORT_SYMBOL(jbd2_journal_invalidatepage); | |
82 | EXPORT_SYMBOL(jbd2_journal_try_to_free_buffers); | |
83 | EXPORT_SYMBOL(jbd2_journal_force_commit); | |
c851ed54 JK |
84 | EXPORT_SYMBOL(jbd2_journal_file_inode); |
85 | EXPORT_SYMBOL(jbd2_journal_init_jbd_inode); | |
86 | EXPORT_SYMBOL(jbd2_journal_release_jbd_inode); | |
87 | EXPORT_SYMBOL(jbd2_journal_begin_ordered_truncate); | |
470decc6 DK |
88 | |
89 | static int journal_convert_superblock_v1(journal_t *, journal_superblock_t *); | |
90 | static void __journal_abort_soft (journal_t *journal, int errno); | |
470decc6 DK |
91 | |
92 | /* | |
93 | * Helper function used to manage commit timeouts | |
94 | */ | |
95 | ||
96 | static void commit_timeout(unsigned long __data) | |
97 | { | |
98 | struct task_struct * p = (struct task_struct *) __data; | |
99 | ||
100 | wake_up_process(p); | |
101 | } | |
102 | ||
103 | /* | |
f7f4bccb | 104 | * kjournald2: The main thread function used to manage a logging device |
470decc6 DK |
105 | * journal. |
106 | * | |
107 | * This kernel thread is responsible for two things: | |
108 | * | |
109 | * 1) COMMIT: Every so often we need to commit the current state of the | |
110 | * filesystem to disk. The journal thread is responsible for writing | |
111 | * all of the metadata buffers to disk. | |
112 | * | |
113 | * 2) CHECKPOINT: We cannot reuse a used section of the log file until all | |
114 | * of the data in that part of the log has been rewritten elsewhere on | |
115 | * the disk. Flushing these old buffers to reclaim space in the log is | |
116 | * known as checkpointing, and this thread is responsible for that job. | |
117 | */ | |
118 | ||
f7f4bccb | 119 | static int kjournald2(void *arg) |
470decc6 DK |
120 | { |
121 | journal_t *journal = arg; | |
122 | transaction_t *transaction; | |
123 | ||
124 | /* | |
125 | * Set up an interval timer which can be used to trigger a commit wakeup | |
126 | * after the commit interval expires | |
127 | */ | |
128 | setup_timer(&journal->j_commit_timer, commit_timeout, | |
129 | (unsigned long)current); | |
130 | ||
131 | /* Record that the journal thread is running */ | |
132 | journal->j_task = current; | |
133 | wake_up(&journal->j_wait_done_commit); | |
134 | ||
4a9bf99b TT |
135 | printk(KERN_INFO "kjournald2 starting: pid %d, dev %s, " |
136 | "commit interval %ld seconds\n", current->pid, | |
137 | journal->j_devname, journal->j_commit_interval / HZ); | |
470decc6 DK |
138 | |
139 | /* | |
140 | * And now, wait forever for commit wakeup events. | |
141 | */ | |
142 | spin_lock(&journal->j_state_lock); | |
143 | ||
144 | loop: | |
f7f4bccb | 145 | if (journal->j_flags & JBD2_UNMOUNT) |
470decc6 DK |
146 | goto end_loop; |
147 | ||
148 | jbd_debug(1, "commit_sequence=%d, commit_request=%d\n", | |
149 | journal->j_commit_sequence, journal->j_commit_request); | |
150 | ||
151 | if (journal->j_commit_sequence != journal->j_commit_request) { | |
152 | jbd_debug(1, "OK, requests differ\n"); | |
153 | spin_unlock(&journal->j_state_lock); | |
154 | del_timer_sync(&journal->j_commit_timer); | |
f7f4bccb | 155 | jbd2_journal_commit_transaction(journal); |
470decc6 DK |
156 | spin_lock(&journal->j_state_lock); |
157 | goto loop; | |
158 | } | |
159 | ||
160 | wake_up(&journal->j_wait_done_commit); | |
161 | if (freezing(current)) { | |
162 | /* | |
163 | * The simpler the better. Flushing journal isn't a | |
164 | * good idea, because that depends on threads that may | |
165 | * be already stopped. | |
166 | */ | |
f7f4bccb | 167 | jbd_debug(1, "Now suspending kjournald2\n"); |
470decc6 DK |
168 | spin_unlock(&journal->j_state_lock); |
169 | refrigerator(); | |
170 | spin_lock(&journal->j_state_lock); | |
171 | } else { | |
172 | /* | |
173 | * We assume on resume that commits are already there, | |
174 | * so we don't sleep | |
175 | */ | |
176 | DEFINE_WAIT(wait); | |
177 | int should_sleep = 1; | |
178 | ||
179 | prepare_to_wait(&journal->j_wait_commit, &wait, | |
180 | TASK_INTERRUPTIBLE); | |
181 | if (journal->j_commit_sequence != journal->j_commit_request) | |
182 | should_sleep = 0; | |
183 | transaction = journal->j_running_transaction; | |
184 | if (transaction && time_after_eq(jiffies, | |
185 | transaction->t_expires)) | |
186 | should_sleep = 0; | |
f7f4bccb | 187 | if (journal->j_flags & JBD2_UNMOUNT) |
470decc6 DK |
188 | should_sleep = 0; |
189 | if (should_sleep) { | |
190 | spin_unlock(&journal->j_state_lock); | |
191 | schedule(); | |
192 | spin_lock(&journal->j_state_lock); | |
193 | } | |
194 | finish_wait(&journal->j_wait_commit, &wait); | |
195 | } | |
196 | ||
f7f4bccb | 197 | jbd_debug(1, "kjournald2 wakes\n"); |
470decc6 DK |
198 | |
199 | /* | |
200 | * Were we woken up by a commit wakeup event? | |
201 | */ | |
202 | transaction = journal->j_running_transaction; | |
203 | if (transaction && time_after_eq(jiffies, transaction->t_expires)) { | |
204 | journal->j_commit_request = transaction->t_tid; | |
205 | jbd_debug(1, "woke because of timeout\n"); | |
206 | } | |
207 | goto loop; | |
208 | ||
209 | end_loop: | |
210 | spin_unlock(&journal->j_state_lock); | |
211 | del_timer_sync(&journal->j_commit_timer); | |
212 | journal->j_task = NULL; | |
213 | wake_up(&journal->j_wait_done_commit); | |
214 | jbd_debug(1, "Journal thread exiting.\n"); | |
215 | return 0; | |
216 | } | |
217 | ||
97f06784 | 218 | static int jbd2_journal_start_thread(journal_t *journal) |
470decc6 | 219 | { |
97f06784 PE |
220 | struct task_struct *t; |
221 | ||
222 | t = kthread_run(kjournald2, journal, "kjournald2"); | |
223 | if (IS_ERR(t)) | |
224 | return PTR_ERR(t); | |
225 | ||
1076d17a | 226 | wait_event(journal->j_wait_done_commit, journal->j_task != NULL); |
97f06784 | 227 | return 0; |
470decc6 DK |
228 | } |
229 | ||
230 | static void journal_kill_thread(journal_t *journal) | |
231 | { | |
232 | spin_lock(&journal->j_state_lock); | |
f7f4bccb | 233 | journal->j_flags |= JBD2_UNMOUNT; |
470decc6 DK |
234 | |
235 | while (journal->j_task) { | |
236 | wake_up(&journal->j_wait_commit); | |
237 | spin_unlock(&journal->j_state_lock); | |
1076d17a | 238 | wait_event(journal->j_wait_done_commit, journal->j_task == NULL); |
470decc6 DK |
239 | spin_lock(&journal->j_state_lock); |
240 | } | |
241 | spin_unlock(&journal->j_state_lock); | |
242 | } | |
243 | ||
244 | /* | |
f7f4bccb | 245 | * jbd2_journal_write_metadata_buffer: write a metadata buffer to the journal. |
470decc6 DK |
246 | * |
247 | * Writes a metadata buffer to a given disk block. The actual IO is not | |
248 | * performed but a new buffer_head is constructed which labels the data | |
249 | * to be written with the correct destination disk block. | |
250 | * | |
251 | * Any magic-number escaping which needs to be done will cause a | |
252 | * copy-out here. If the buffer happens to start with the | |
f7f4bccb | 253 | * JBD2_MAGIC_NUMBER, then we can't write it to the log directly: the |
470decc6 DK |
254 | * magic number is only written to the log for descripter blocks. In |
255 | * this case, we copy the data and replace the first word with 0, and we | |
256 | * return a result code which indicates that this buffer needs to be | |
257 | * marked as an escaped buffer in the corresponding log descriptor | |
258 | * block. The missing word can then be restored when the block is read | |
259 | * during recovery. | |
260 | * | |
261 | * If the source buffer has already been modified by a new transaction | |
262 | * since we took the last commit snapshot, we use the frozen copy of | |
263 | * that data for IO. If we end up using the existing buffer_head's data | |
264 | * for the write, then we *have* to lock the buffer to prevent anyone | |
265 | * else from using and possibly modifying it while the IO is in | |
266 | * progress. | |
267 | * | |
268 | * The function returns a pointer to the buffer_heads to be used for IO. | |
269 | * | |
270 | * We assume that the journal has already been locked in this function. | |
271 | * | |
272 | * Return value: | |
273 | * <0: Error | |
274 | * >=0: Finished OK | |
275 | * | |
276 | * On success: | |
277 | * Bit 0 set == escape performed on the data | |
278 | * Bit 1 set == buffer copy-out performed (kfree the data after IO) | |
279 | */ | |
280 | ||
f7f4bccb | 281 | int jbd2_journal_write_metadata_buffer(transaction_t *transaction, |
470decc6 DK |
282 | struct journal_head *jh_in, |
283 | struct journal_head **jh_out, | |
18eba7aa | 284 | unsigned long long blocknr) |
470decc6 DK |
285 | { |
286 | int need_copy_out = 0; | |
287 | int done_copy_out = 0; | |
288 | int do_escape = 0; | |
289 | char *mapped_data; | |
290 | struct buffer_head *new_bh; | |
291 | struct journal_head *new_jh; | |
292 | struct page *new_page; | |
293 | unsigned int new_offset; | |
294 | struct buffer_head *bh_in = jh2bh(jh_in); | |
e06c8227 | 295 | struct jbd2_buffer_trigger_type *triggers; |
470decc6 DK |
296 | |
297 | /* | |
298 | * The buffer really shouldn't be locked: only the current committing | |
299 | * transaction is allowed to write it, so nobody else is allowed | |
300 | * to do any IO. | |
301 | * | |
302 | * akpm: except if we're journalling data, and write() output is | |
303 | * also part of a shared mapping, and another thread has | |
304 | * decided to launch a writepage() against this buffer. | |
305 | */ | |
306 | J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in)); | |
307 | ||
308 | new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL); | |
309 | ||
310 | /* | |
311 | * If a new transaction has already done a buffer copy-out, then | |
312 | * we use that version of the data for the commit. | |
313 | */ | |
314 | jbd_lock_bh_state(bh_in); | |
315 | repeat: | |
316 | if (jh_in->b_frozen_data) { | |
317 | done_copy_out = 1; | |
318 | new_page = virt_to_page(jh_in->b_frozen_data); | |
319 | new_offset = offset_in_page(jh_in->b_frozen_data); | |
e06c8227 | 320 | triggers = jh_in->b_frozen_triggers; |
470decc6 DK |
321 | } else { |
322 | new_page = jh2bh(jh_in)->b_page; | |
323 | new_offset = offset_in_page(jh2bh(jh_in)->b_data); | |
e06c8227 | 324 | triggers = jh_in->b_triggers; |
470decc6 DK |
325 | } |
326 | ||
327 | mapped_data = kmap_atomic(new_page, KM_USER0); | |
e06c8227 JB |
328 | /* |
329 | * Fire any commit trigger. Do this before checking for escaping, | |
330 | * as the trigger may modify the magic offset. If a copy-out | |
331 | * happens afterwards, it will have the correct data in the buffer. | |
332 | */ | |
333 | jbd2_buffer_commit_trigger(jh_in, mapped_data + new_offset, | |
334 | triggers); | |
335 | ||
470decc6 DK |
336 | /* |
337 | * Check for escaping | |
338 | */ | |
339 | if (*((__be32 *)(mapped_data + new_offset)) == | |
f7f4bccb | 340 | cpu_to_be32(JBD2_MAGIC_NUMBER)) { |
470decc6 DK |
341 | need_copy_out = 1; |
342 | do_escape = 1; | |
343 | } | |
344 | kunmap_atomic(mapped_data, KM_USER0); | |
345 | ||
346 | /* | |
347 | * Do we need to do a data copy? | |
348 | */ | |
349 | if (need_copy_out && !done_copy_out) { | |
350 | char *tmp; | |
351 | ||
352 | jbd_unlock_bh_state(bh_in); | |
af1e76d6 | 353 | tmp = jbd2_alloc(bh_in->b_size, GFP_NOFS); |
470decc6 DK |
354 | jbd_lock_bh_state(bh_in); |
355 | if (jh_in->b_frozen_data) { | |
af1e76d6 | 356 | jbd2_free(tmp, bh_in->b_size); |
470decc6 DK |
357 | goto repeat; |
358 | } | |
359 | ||
360 | jh_in->b_frozen_data = tmp; | |
361 | mapped_data = kmap_atomic(new_page, KM_USER0); | |
362 | memcpy(tmp, mapped_data + new_offset, jh2bh(jh_in)->b_size); | |
363 | kunmap_atomic(mapped_data, KM_USER0); | |
364 | ||
365 | new_page = virt_to_page(tmp); | |
366 | new_offset = offset_in_page(tmp); | |
367 | done_copy_out = 1; | |
e06c8227 JB |
368 | |
369 | /* | |
370 | * This isn't strictly necessary, as we're using frozen | |
371 | * data for the escaping, but it keeps consistency with | |
372 | * b_frozen_data usage. | |
373 | */ | |
374 | jh_in->b_frozen_triggers = jh_in->b_triggers; | |
470decc6 DK |
375 | } |
376 | ||
377 | /* | |
378 | * Did we need to do an escaping? Now we've done all the | |
379 | * copying, we can finally do so. | |
380 | */ | |
381 | if (do_escape) { | |
382 | mapped_data = kmap_atomic(new_page, KM_USER0); | |
383 | *((unsigned int *)(mapped_data + new_offset)) = 0; | |
384 | kunmap_atomic(mapped_data, KM_USER0); | |
385 | } | |
386 | ||
387 | /* keep subsequent assertions sane */ | |
388 | new_bh->b_state = 0; | |
389 | init_buffer(new_bh, NULL, NULL); | |
390 | atomic_set(&new_bh->b_count, 1); | |
391 | jbd_unlock_bh_state(bh_in); | |
392 | ||
f7f4bccb | 393 | new_jh = jbd2_journal_add_journal_head(new_bh); /* This sleeps */ |
470decc6 DK |
394 | |
395 | set_bh_page(new_bh, new_page, new_offset); | |
396 | new_jh->b_transaction = NULL; | |
397 | new_bh->b_size = jh2bh(jh_in)->b_size; | |
398 | new_bh->b_bdev = transaction->t_journal->j_dev; | |
399 | new_bh->b_blocknr = blocknr; | |
400 | set_buffer_mapped(new_bh); | |
401 | set_buffer_dirty(new_bh); | |
402 | ||
403 | *jh_out = new_jh; | |
404 | ||
405 | /* | |
406 | * The to-be-written buffer needs to get moved to the io queue, | |
407 | * and the original buffer whose contents we are shadowing or | |
408 | * copying is moved to the transaction's shadow queue. | |
409 | */ | |
410 | JBUFFER_TRACE(jh_in, "file as BJ_Shadow"); | |
f7f4bccb | 411 | jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow); |
470decc6 | 412 | JBUFFER_TRACE(new_jh, "file as BJ_IO"); |
f7f4bccb | 413 | jbd2_journal_file_buffer(new_jh, transaction, BJ_IO); |
470decc6 DK |
414 | |
415 | return do_escape | (done_copy_out << 1); | |
416 | } | |
417 | ||
418 | /* | |
419 | * Allocation code for the journal file. Manage the space left in the | |
420 | * journal, so that we can begin checkpointing when appropriate. | |
421 | */ | |
422 | ||
423 | /* | |
f7f4bccb | 424 | * __jbd2_log_space_left: Return the number of free blocks left in the journal. |
470decc6 DK |
425 | * |
426 | * Called with the journal already locked. | |
427 | * | |
428 | * Called under j_state_lock | |
429 | */ | |
430 | ||
f7f4bccb | 431 | int __jbd2_log_space_left(journal_t *journal) |
470decc6 DK |
432 | { |
433 | int left = journal->j_free; | |
434 | ||
435 | assert_spin_locked(&journal->j_state_lock); | |
436 | ||
437 | /* | |
438 | * Be pessimistic here about the number of those free blocks which | |
439 | * might be required for log descriptor control blocks. | |
440 | */ | |
441 | ||
442 | #define MIN_LOG_RESERVED_BLOCKS 32 /* Allow for rounding errors */ | |
443 | ||
444 | left -= MIN_LOG_RESERVED_BLOCKS; | |
445 | ||
446 | if (left <= 0) | |
447 | return 0; | |
448 | left -= (left >> 3); | |
449 | return left; | |
450 | } | |
451 | ||
452 | /* | |
453 | * Called under j_state_lock. Returns true if a transaction was started. | |
454 | */ | |
f7f4bccb | 455 | int __jbd2_log_start_commit(journal_t *journal, tid_t target) |
470decc6 DK |
456 | { |
457 | /* | |
458 | * Are we already doing a recent enough commit? | |
459 | */ | |
460 | if (!tid_geq(journal->j_commit_request, target)) { | |
461 | /* | |
462 | * We want a new commit: OK, mark the request and wakup the | |
463 | * commit thread. We do _not_ do the commit ourselves. | |
464 | */ | |
465 | ||
466 | journal->j_commit_request = target; | |
467 | jbd_debug(1, "JBD: requesting commit %d/%d\n", | |
468 | journal->j_commit_request, | |
469 | journal->j_commit_sequence); | |
470 | wake_up(&journal->j_wait_commit); | |
471 | return 1; | |
472 | } | |
473 | return 0; | |
474 | } | |
475 | ||
f7f4bccb | 476 | int jbd2_log_start_commit(journal_t *journal, tid_t tid) |
470decc6 DK |
477 | { |
478 | int ret; | |
479 | ||
480 | spin_lock(&journal->j_state_lock); | |
f7f4bccb | 481 | ret = __jbd2_log_start_commit(journal, tid); |
470decc6 DK |
482 | spin_unlock(&journal->j_state_lock); |
483 | return ret; | |
484 | } | |
485 | ||
486 | /* | |
487 | * Force and wait upon a commit if the calling process is not within | |
488 | * transaction. This is used for forcing out undo-protected data which contains | |
489 | * bitmaps, when the fs is running out of space. | |
490 | * | |
491 | * We can only force the running transaction if we don't have an active handle; | |
492 | * otherwise, we will deadlock. | |
493 | * | |
494 | * Returns true if a transaction was started. | |
495 | */ | |
f7f4bccb | 496 | int jbd2_journal_force_commit_nested(journal_t *journal) |
470decc6 DK |
497 | { |
498 | transaction_t *transaction = NULL; | |
499 | tid_t tid; | |
500 | ||
501 | spin_lock(&journal->j_state_lock); | |
502 | if (journal->j_running_transaction && !current->journal_info) { | |
503 | transaction = journal->j_running_transaction; | |
f7f4bccb | 504 | __jbd2_log_start_commit(journal, transaction->t_tid); |
470decc6 DK |
505 | } else if (journal->j_committing_transaction) |
506 | transaction = journal->j_committing_transaction; | |
507 | ||
508 | if (!transaction) { | |
509 | spin_unlock(&journal->j_state_lock); | |
510 | return 0; /* Nothing to retry */ | |
511 | } | |
512 | ||
513 | tid = transaction->t_tid; | |
514 | spin_unlock(&journal->j_state_lock); | |
f7f4bccb | 515 | jbd2_log_wait_commit(journal, tid); |
470decc6 DK |
516 | return 1; |
517 | } | |
518 | ||
519 | /* | |
520 | * Start a commit of the current running transaction (if any). Returns true | |
521 | * if a transaction was started, and fills its tid in at *ptid | |
522 | */ | |
f7f4bccb | 523 | int jbd2_journal_start_commit(journal_t *journal, tid_t *ptid) |
470decc6 DK |
524 | { |
525 | int ret = 0; | |
526 | ||
527 | spin_lock(&journal->j_state_lock); | |
528 | if (journal->j_running_transaction) { | |
529 | tid_t tid = journal->j_running_transaction->t_tid; | |
530 | ||
f7f4bccb | 531 | ret = __jbd2_log_start_commit(journal, tid); |
470decc6 DK |
532 | if (ret && ptid) |
533 | *ptid = tid; | |
534 | } else if (journal->j_committing_transaction && ptid) { | |
535 | /* | |
536 | * If ext3_write_super() recently started a commit, then we | |
537 | * have to wait for completion of that transaction | |
538 | */ | |
539 | *ptid = journal->j_committing_transaction->t_tid; | |
540 | ret = 1; | |
541 | } | |
542 | spin_unlock(&journal->j_state_lock); | |
543 | return ret; | |
544 | } | |
545 | ||
546 | /* | |
547 | * Wait for a specified commit to complete. | |
548 | * The caller may not hold the journal lock. | |
549 | */ | |
f7f4bccb | 550 | int jbd2_log_wait_commit(journal_t *journal, tid_t tid) |
470decc6 DK |
551 | { |
552 | int err = 0; | |
553 | ||
e23291b9 | 554 | #ifdef CONFIG_JBD2_DEBUG |
470decc6 DK |
555 | spin_lock(&journal->j_state_lock); |
556 | if (!tid_geq(journal->j_commit_request, tid)) { | |
557 | printk(KERN_EMERG | |
558 | "%s: error: j_commit_request=%d, tid=%d\n", | |
329d291f | 559 | __func__, journal->j_commit_request, tid); |
470decc6 DK |
560 | } |
561 | spin_unlock(&journal->j_state_lock); | |
562 | #endif | |
563 | spin_lock(&journal->j_state_lock); | |
564 | while (tid_gt(tid, journal->j_commit_sequence)) { | |
565 | jbd_debug(1, "JBD: want %d, j_commit_sequence=%d\n", | |
566 | tid, journal->j_commit_sequence); | |
567 | wake_up(&journal->j_wait_commit); | |
568 | spin_unlock(&journal->j_state_lock); | |
569 | wait_event(journal->j_wait_done_commit, | |
570 | !tid_gt(tid, journal->j_commit_sequence)); | |
571 | spin_lock(&journal->j_state_lock); | |
572 | } | |
573 | spin_unlock(&journal->j_state_lock); | |
574 | ||
575 | if (unlikely(is_journal_aborted(journal))) { | |
576 | printk(KERN_EMERG "journal commit I/O error\n"); | |
577 | err = -EIO; | |
578 | } | |
579 | return err; | |
580 | } | |
581 | ||
582 | /* | |
583 | * Log buffer allocation routines: | |
584 | */ | |
585 | ||
18eba7aa | 586 | int jbd2_journal_next_log_block(journal_t *journal, unsigned long long *retp) |
470decc6 DK |
587 | { |
588 | unsigned long blocknr; | |
589 | ||
590 | spin_lock(&journal->j_state_lock); | |
591 | J_ASSERT(journal->j_free > 1); | |
592 | ||
593 | blocknr = journal->j_head; | |
594 | journal->j_head++; | |
595 | journal->j_free--; | |
596 | if (journal->j_head == journal->j_last) | |
597 | journal->j_head = journal->j_first; | |
598 | spin_unlock(&journal->j_state_lock); | |
f7f4bccb | 599 | return jbd2_journal_bmap(journal, blocknr, retp); |
470decc6 DK |
600 | } |
601 | ||
602 | /* | |
603 | * Conversion of logical to physical block numbers for the journal | |
604 | * | |
605 | * On external journals the journal blocks are identity-mapped, so | |
606 | * this is a no-op. If needed, we can use j_blk_offset - everything is | |
607 | * ready. | |
608 | */ | |
f7f4bccb | 609 | int jbd2_journal_bmap(journal_t *journal, unsigned long blocknr, |
18eba7aa | 610 | unsigned long long *retp) |
470decc6 DK |
611 | { |
612 | int err = 0; | |
18eba7aa | 613 | unsigned long long ret; |
470decc6 DK |
614 | |
615 | if (journal->j_inode) { | |
616 | ret = bmap(journal->j_inode, blocknr); | |
617 | if (ret) | |
618 | *retp = ret; | |
619 | else { | |
470decc6 DK |
620 | printk(KERN_ALERT "%s: journal block not found " |
621 | "at offset %lu on %s\n", | |
05496769 | 622 | __func__, blocknr, journal->j_devname); |
470decc6 DK |
623 | err = -EIO; |
624 | __journal_abort_soft(journal, err); | |
625 | } | |
626 | } else { | |
627 | *retp = blocknr; /* +journal->j_blk_offset */ | |
628 | } | |
629 | return err; | |
630 | } | |
631 | ||
632 | /* | |
633 | * We play buffer_head aliasing tricks to write data/metadata blocks to | |
634 | * the journal without copying their contents, but for journal | |
635 | * descriptor blocks we do need to generate bona fide buffers. | |
636 | * | |
f7f4bccb | 637 | * After the caller of jbd2_journal_get_descriptor_buffer() has finished modifying |
470decc6 DK |
638 | * the buffer's contents they really should run flush_dcache_page(bh->b_page). |
639 | * But we don't bother doing that, so there will be coherency problems with | |
640 | * mmaps of blockdevs which hold live JBD-controlled filesystems. | |
641 | */ | |
f7f4bccb | 642 | struct journal_head *jbd2_journal_get_descriptor_buffer(journal_t *journal) |
470decc6 DK |
643 | { |
644 | struct buffer_head *bh; | |
18eba7aa | 645 | unsigned long long blocknr; |
470decc6 DK |
646 | int err; |
647 | ||
f7f4bccb | 648 | err = jbd2_journal_next_log_block(journal, &blocknr); |
470decc6 DK |
649 | |
650 | if (err) | |
651 | return NULL; | |
652 | ||
653 | bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); | |
4b905671 JK |
654 | if (!bh) |
655 | return NULL; | |
470decc6 DK |
656 | lock_buffer(bh); |
657 | memset(bh->b_data, 0, journal->j_blocksize); | |
658 | set_buffer_uptodate(bh); | |
659 | unlock_buffer(bh); | |
660 | BUFFER_TRACE(bh, "return this buffer"); | |
f7f4bccb | 661 | return jbd2_journal_add_journal_head(bh); |
470decc6 DK |
662 | } |
663 | ||
8e85fb3f JL |
664 | struct jbd2_stats_proc_session { |
665 | journal_t *journal; | |
666 | struct transaction_stats_s *stats; | |
667 | int start; | |
668 | int max; | |
669 | }; | |
670 | ||
671 | static void *jbd2_history_skip_empty(struct jbd2_stats_proc_session *s, | |
672 | struct transaction_stats_s *ts, | |
673 | int first) | |
674 | { | |
675 | if (ts == s->stats + s->max) | |
676 | ts = s->stats; | |
677 | if (!first && ts == s->stats + s->start) | |
678 | return NULL; | |
679 | while (ts->ts_type == 0) { | |
680 | ts++; | |
681 | if (ts == s->stats + s->max) | |
682 | ts = s->stats; | |
683 | if (ts == s->stats + s->start) | |
684 | return NULL; | |
685 | } | |
686 | return ts; | |
687 | ||
688 | } | |
689 | ||
690 | static void *jbd2_seq_history_start(struct seq_file *seq, loff_t *pos) | |
691 | { | |
692 | struct jbd2_stats_proc_session *s = seq->private; | |
693 | struct transaction_stats_s *ts; | |
694 | int l = *pos; | |
695 | ||
696 | if (l == 0) | |
697 | return SEQ_START_TOKEN; | |
698 | ts = jbd2_history_skip_empty(s, s->stats + s->start, 1); | |
699 | if (!ts) | |
700 | return NULL; | |
701 | l--; | |
702 | while (l) { | |
703 | ts = jbd2_history_skip_empty(s, ++ts, 0); | |
704 | if (!ts) | |
705 | break; | |
706 | l--; | |
707 | } | |
708 | return ts; | |
709 | } | |
710 | ||
711 | static void *jbd2_seq_history_next(struct seq_file *seq, void *v, loff_t *pos) | |
712 | { | |
713 | struct jbd2_stats_proc_session *s = seq->private; | |
714 | struct transaction_stats_s *ts = v; | |
715 | ||
716 | ++*pos; | |
717 | if (v == SEQ_START_TOKEN) | |
718 | return jbd2_history_skip_empty(s, s->stats + s->start, 1); | |
719 | else | |
720 | return jbd2_history_skip_empty(s, ++ts, 0); | |
721 | } | |
722 | ||
723 | static int jbd2_seq_history_show(struct seq_file *seq, void *v) | |
724 | { | |
725 | struct transaction_stats_s *ts = v; | |
726 | if (v == SEQ_START_TOKEN) { | |
727 | seq_printf(seq, "%-4s %-5s %-5s %-5s %-5s %-5s %-5s %-6s %-5s " | |
728 | "%-5s %-5s %-5s %-5s %-5s\n", "R/C", "tid", | |
729 | "wait", "run", "lock", "flush", "log", "hndls", | |
730 | "block", "inlog", "ctime", "write", "drop", | |
731 | "close"); | |
732 | return 0; | |
733 | } | |
734 | if (ts->ts_type == JBD2_STATS_RUN) | |
735 | seq_printf(seq, "%-4s %-5lu %-5u %-5u %-5u %-5u %-5u " | |
736 | "%-6lu %-5lu %-5lu\n", "R", ts->ts_tid, | |
737 | jiffies_to_msecs(ts->u.run.rs_wait), | |
738 | jiffies_to_msecs(ts->u.run.rs_running), | |
739 | jiffies_to_msecs(ts->u.run.rs_locked), | |
740 | jiffies_to_msecs(ts->u.run.rs_flushing), | |
741 | jiffies_to_msecs(ts->u.run.rs_logging), | |
742 | ts->u.run.rs_handle_count, | |
743 | ts->u.run.rs_blocks, | |
744 | ts->u.run.rs_blocks_logged); | |
745 | else if (ts->ts_type == JBD2_STATS_CHECKPOINT) | |
746 | seq_printf(seq, "%-4s %-5lu %48s %-5u %-5lu %-5lu %-5lu\n", | |
747 | "C", ts->ts_tid, " ", | |
748 | jiffies_to_msecs(ts->u.chp.cs_chp_time), | |
749 | ts->u.chp.cs_written, ts->u.chp.cs_dropped, | |
750 | ts->u.chp.cs_forced_to_close); | |
751 | else | |
752 | J_ASSERT(0); | |
753 | return 0; | |
754 | } | |
755 | ||
756 | static void jbd2_seq_history_stop(struct seq_file *seq, void *v) | |
757 | { | |
758 | } | |
759 | ||
760 | static struct seq_operations jbd2_seq_history_ops = { | |
761 | .start = jbd2_seq_history_start, | |
762 | .next = jbd2_seq_history_next, | |
763 | .stop = jbd2_seq_history_stop, | |
764 | .show = jbd2_seq_history_show, | |
765 | }; | |
766 | ||
767 | static int jbd2_seq_history_open(struct inode *inode, struct file *file) | |
768 | { | |
769 | journal_t *journal = PDE(inode)->data; | |
770 | struct jbd2_stats_proc_session *s; | |
771 | int rc, size; | |
772 | ||
773 | s = kmalloc(sizeof(*s), GFP_KERNEL); | |
774 | if (s == NULL) | |
775 | return -ENOMEM; | |
776 | size = sizeof(struct transaction_stats_s) * journal->j_history_max; | |
777 | s->stats = kmalloc(size, GFP_KERNEL); | |
778 | if (s->stats == NULL) { | |
779 | kfree(s); | |
780 | return -ENOMEM; | |
781 | } | |
782 | spin_lock(&journal->j_history_lock); | |
783 | memcpy(s->stats, journal->j_history, size); | |
784 | s->max = journal->j_history_max; | |
785 | s->start = journal->j_history_cur % s->max; | |
786 | spin_unlock(&journal->j_history_lock); | |
787 | ||
788 | rc = seq_open(file, &jbd2_seq_history_ops); | |
789 | if (rc == 0) { | |
790 | struct seq_file *m = file->private_data; | |
791 | m->private = s; | |
792 | } else { | |
793 | kfree(s->stats); | |
794 | kfree(s); | |
795 | } | |
796 | return rc; | |
797 | ||
798 | } | |
799 | ||
800 | static int jbd2_seq_history_release(struct inode *inode, struct file *file) | |
801 | { | |
802 | struct seq_file *seq = file->private_data; | |
803 | struct jbd2_stats_proc_session *s = seq->private; | |
804 | ||
805 | kfree(s->stats); | |
806 | kfree(s); | |
807 | return seq_release(inode, file); | |
808 | } | |
809 | ||
810 | static struct file_operations jbd2_seq_history_fops = { | |
811 | .owner = THIS_MODULE, | |
812 | .open = jbd2_seq_history_open, | |
813 | .read = seq_read, | |
814 | .llseek = seq_lseek, | |
815 | .release = jbd2_seq_history_release, | |
816 | }; | |
817 | ||
818 | static void *jbd2_seq_info_start(struct seq_file *seq, loff_t *pos) | |
819 | { | |
820 | return *pos ? NULL : SEQ_START_TOKEN; | |
821 | } | |
822 | ||
823 | static void *jbd2_seq_info_next(struct seq_file *seq, void *v, loff_t *pos) | |
824 | { | |
825 | return NULL; | |
826 | } | |
827 | ||
828 | static int jbd2_seq_info_show(struct seq_file *seq, void *v) | |
829 | { | |
830 | struct jbd2_stats_proc_session *s = seq->private; | |
831 | ||
832 | if (v != SEQ_START_TOKEN) | |
833 | return 0; | |
834 | seq_printf(seq, "%lu transaction, each upto %u blocks\n", | |
835 | s->stats->ts_tid, | |
836 | s->journal->j_max_transaction_buffers); | |
837 | if (s->stats->ts_tid == 0) | |
838 | return 0; | |
839 | seq_printf(seq, "average: \n %ums waiting for transaction\n", | |
840 | jiffies_to_msecs(s->stats->u.run.rs_wait / s->stats->ts_tid)); | |
841 | seq_printf(seq, " %ums running transaction\n", | |
842 | jiffies_to_msecs(s->stats->u.run.rs_running / s->stats->ts_tid)); | |
843 | seq_printf(seq, " %ums transaction was being locked\n", | |
844 | jiffies_to_msecs(s->stats->u.run.rs_locked / s->stats->ts_tid)); | |
845 | seq_printf(seq, " %ums flushing data (in ordered mode)\n", | |
846 | jiffies_to_msecs(s->stats->u.run.rs_flushing / s->stats->ts_tid)); | |
847 | seq_printf(seq, " %ums logging transaction\n", | |
848 | jiffies_to_msecs(s->stats->u.run.rs_logging / s->stats->ts_tid)); | |
d7cfa468 TT |
849 | seq_printf(seq, " %luus average transaction commit time\n", |
850 | do_div(s->journal->j_average_commit_time, 1000)); | |
8e85fb3f JL |
851 | seq_printf(seq, " %lu handles per transaction\n", |
852 | s->stats->u.run.rs_handle_count / s->stats->ts_tid); | |
853 | seq_printf(seq, " %lu blocks per transaction\n", | |
854 | s->stats->u.run.rs_blocks / s->stats->ts_tid); | |
855 | seq_printf(seq, " %lu logged blocks per transaction\n", | |
856 | s->stats->u.run.rs_blocks_logged / s->stats->ts_tid); | |
857 | return 0; | |
858 | } | |
859 | ||
860 | static void jbd2_seq_info_stop(struct seq_file *seq, void *v) | |
861 | { | |
862 | } | |
863 | ||
864 | static struct seq_operations jbd2_seq_info_ops = { | |
865 | .start = jbd2_seq_info_start, | |
866 | .next = jbd2_seq_info_next, | |
867 | .stop = jbd2_seq_info_stop, | |
868 | .show = jbd2_seq_info_show, | |
869 | }; | |
870 | ||
871 | static int jbd2_seq_info_open(struct inode *inode, struct file *file) | |
872 | { | |
873 | journal_t *journal = PDE(inode)->data; | |
874 | struct jbd2_stats_proc_session *s; | |
875 | int rc, size; | |
876 | ||
877 | s = kmalloc(sizeof(*s), GFP_KERNEL); | |
878 | if (s == NULL) | |
879 | return -ENOMEM; | |
880 | size = sizeof(struct transaction_stats_s); | |
881 | s->stats = kmalloc(size, GFP_KERNEL); | |
882 | if (s->stats == NULL) { | |
883 | kfree(s); | |
884 | return -ENOMEM; | |
885 | } | |
886 | spin_lock(&journal->j_history_lock); | |
887 | memcpy(s->stats, &journal->j_stats, size); | |
888 | s->journal = journal; | |
889 | spin_unlock(&journal->j_history_lock); | |
890 | ||
891 | rc = seq_open(file, &jbd2_seq_info_ops); | |
892 | if (rc == 0) { | |
893 | struct seq_file *m = file->private_data; | |
894 | m->private = s; | |
895 | } else { | |
896 | kfree(s->stats); | |
897 | kfree(s); | |
898 | } | |
899 | return rc; | |
900 | ||
901 | } | |
902 | ||
903 | static int jbd2_seq_info_release(struct inode *inode, struct file *file) | |
904 | { | |
905 | struct seq_file *seq = file->private_data; | |
906 | struct jbd2_stats_proc_session *s = seq->private; | |
907 | kfree(s->stats); | |
908 | kfree(s); | |
909 | return seq_release(inode, file); | |
910 | } | |
911 | ||
912 | static struct file_operations jbd2_seq_info_fops = { | |
913 | .owner = THIS_MODULE, | |
914 | .open = jbd2_seq_info_open, | |
915 | .read = seq_read, | |
916 | .llseek = seq_lseek, | |
917 | .release = jbd2_seq_info_release, | |
918 | }; | |
919 | ||
920 | static struct proc_dir_entry *proc_jbd2_stats; | |
921 | ||
922 | static void jbd2_stats_proc_init(journal_t *journal) | |
923 | { | |
05496769 | 924 | journal->j_proc_entry = proc_mkdir(journal->j_devname, proc_jbd2_stats); |
8e85fb3f | 925 | if (journal->j_proc_entry) { |
79da3664 DL |
926 | proc_create_data("history", S_IRUGO, journal->j_proc_entry, |
927 | &jbd2_seq_history_fops, journal); | |
928 | proc_create_data("info", S_IRUGO, journal->j_proc_entry, | |
929 | &jbd2_seq_info_fops, journal); | |
8e85fb3f JL |
930 | } |
931 | } | |
932 | ||
933 | static void jbd2_stats_proc_exit(journal_t *journal) | |
934 | { | |
8e85fb3f JL |
935 | remove_proc_entry("info", journal->j_proc_entry); |
936 | remove_proc_entry("history", journal->j_proc_entry); | |
05496769 | 937 | remove_proc_entry(journal->j_devname, proc_jbd2_stats); |
8e85fb3f JL |
938 | } |
939 | ||
940 | static void journal_init_stats(journal_t *journal) | |
941 | { | |
942 | int size; | |
943 | ||
944 | if (!proc_jbd2_stats) | |
945 | return; | |
946 | ||
947 | journal->j_history_max = 100; | |
948 | size = sizeof(struct transaction_stats_s) * journal->j_history_max; | |
949 | journal->j_history = kzalloc(size, GFP_KERNEL); | |
950 | if (!journal->j_history) { | |
951 | journal->j_history_max = 0; | |
952 | return; | |
953 | } | |
954 | spin_lock_init(&journal->j_history_lock); | |
955 | } | |
956 | ||
470decc6 DK |
957 | /* |
958 | * Management for journal control blocks: functions to create and | |
959 | * destroy journal_t structures, and to initialise and read existing | |
960 | * journal blocks from disk. */ | |
961 | ||
962 | /* First: create and setup a journal_t object in memory. We initialise | |
963 | * very few fields yet: that has to wait until we have created the | |
964 | * journal structures from from scratch, or loaded them from disk. */ | |
965 | ||
966 | static journal_t * journal_init_common (void) | |
967 | { | |
968 | journal_t *journal; | |
969 | int err; | |
970 | ||
d802ffa8 | 971 | journal = kzalloc(sizeof(*journal), GFP_KERNEL|__GFP_NOFAIL); |
470decc6 DK |
972 | if (!journal) |
973 | goto fail; | |
470decc6 DK |
974 | |
975 | init_waitqueue_head(&journal->j_wait_transaction_locked); | |
976 | init_waitqueue_head(&journal->j_wait_logspace); | |
977 | init_waitqueue_head(&journal->j_wait_done_commit); | |
978 | init_waitqueue_head(&journal->j_wait_checkpoint); | |
979 | init_waitqueue_head(&journal->j_wait_commit); | |
980 | init_waitqueue_head(&journal->j_wait_updates); | |
981 | mutex_init(&journal->j_barrier); | |
982 | mutex_init(&journal->j_checkpoint_mutex); | |
983 | spin_lock_init(&journal->j_revoke_lock); | |
984 | spin_lock_init(&journal->j_list_lock); | |
985 | spin_lock_init(&journal->j_state_lock); | |
986 | ||
cd02ff0b | 987 | journal->j_commit_interval = (HZ * JBD2_DEFAULT_MAX_COMMIT_AGE); |
30773840 TT |
988 | journal->j_min_batch_time = 0; |
989 | journal->j_max_batch_time = 15000; /* 15ms */ | |
470decc6 DK |
990 | |
991 | /* The journal is marked for error until we succeed with recovery! */ | |
f7f4bccb | 992 | journal->j_flags = JBD2_ABORT; |
470decc6 DK |
993 | |
994 | /* Set up a default-sized revoke table for the new mount. */ | |
f7f4bccb | 995 | err = jbd2_journal_init_revoke(journal, JOURNAL_REVOKE_DEFAULT_HASH); |
470decc6 DK |
996 | if (err) { |
997 | kfree(journal); | |
998 | goto fail; | |
999 | } | |
8e85fb3f JL |
1000 | |
1001 | journal_init_stats(journal); | |
1002 | ||
470decc6 DK |
1003 | return journal; |
1004 | fail: | |
1005 | return NULL; | |
1006 | } | |
1007 | ||
f7f4bccb | 1008 | /* jbd2_journal_init_dev and jbd2_journal_init_inode: |
470decc6 DK |
1009 | * |
1010 | * Create a journal structure assigned some fixed set of disk blocks to | |
1011 | * the journal. We don't actually touch those disk blocks yet, but we | |
1012 | * need to set up all of the mapping information to tell the journaling | |
1013 | * system where the journal blocks are. | |
1014 | * | |
1015 | */ | |
1016 | ||
1017 | /** | |
5648ba5b | 1018 | * journal_t * jbd2_journal_init_dev() - creates and initialises a journal structure |
470decc6 DK |
1019 | * @bdev: Block device on which to create the journal |
1020 | * @fs_dev: Device which hold journalled filesystem for this journal. | |
1021 | * @start: Block nr Start of journal. | |
1022 | * @len: Length of the journal in blocks. | |
1023 | * @blocksize: blocksize of journalling device | |
5648ba5b RD |
1024 | * |
1025 | * Returns: a newly created journal_t * | |
470decc6 | 1026 | * |
f7f4bccb | 1027 | * jbd2_journal_init_dev creates a journal which maps a fixed contiguous |
470decc6 DK |
1028 | * range of blocks on an arbitrary block device. |
1029 | * | |
1030 | */ | |
f7f4bccb | 1031 | journal_t * jbd2_journal_init_dev(struct block_device *bdev, |
470decc6 | 1032 | struct block_device *fs_dev, |
18eba7aa | 1033 | unsigned long long start, int len, int blocksize) |
470decc6 DK |
1034 | { |
1035 | journal_t *journal = journal_init_common(); | |
1036 | struct buffer_head *bh; | |
05496769 | 1037 | char *p; |
470decc6 DK |
1038 | int n; |
1039 | ||
1040 | if (!journal) | |
1041 | return NULL; | |
1042 | ||
1043 | /* journal descriptor can store up to n blocks -bzzz */ | |
1044 | journal->j_blocksize = blocksize; | |
4b905671 | 1045 | jbd2_stats_proc_init(journal); |
470decc6 DK |
1046 | n = journal->j_blocksize / sizeof(journal_block_tag_t); |
1047 | journal->j_wbufsize = n; | |
1048 | journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL); | |
1049 | if (!journal->j_wbuf) { | |
1050 | printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n", | |
329d291f | 1051 | __func__); |
4b905671 | 1052 | goto out_err; |
470decc6 DK |
1053 | } |
1054 | journal->j_dev = bdev; | |
1055 | journal->j_fs_dev = fs_dev; | |
1056 | journal->j_blk_offset = start; | |
1057 | journal->j_maxlen = len; | |
05496769 TT |
1058 | bdevname(journal->j_dev, journal->j_devname); |
1059 | p = journal->j_devname; | |
1060 | while ((p = strchr(p, '/'))) | |
1061 | *p = '!'; | |
470decc6 DK |
1062 | |
1063 | bh = __getblk(journal->j_dev, start, journal->j_blocksize); | |
4b905671 JK |
1064 | if (!bh) { |
1065 | printk(KERN_ERR | |
1066 | "%s: Cannot get buffer for journal superblock\n", | |
1067 | __func__); | |
1068 | goto out_err; | |
1069 | } | |
470decc6 DK |
1070 | journal->j_sb_buffer = bh; |
1071 | journal->j_superblock = (journal_superblock_t *)bh->b_data; | |
4b905671 | 1072 | |
470decc6 | 1073 | return journal; |
4b905671 JK |
1074 | out_err: |
1075 | jbd2_stats_proc_exit(journal); | |
1076 | kfree(journal); | |
1077 | return NULL; | |
470decc6 DK |
1078 | } |
1079 | ||
1080 | /** | |
f7f4bccb | 1081 | * journal_t * jbd2_journal_init_inode () - creates a journal which maps to a inode. |
470decc6 DK |
1082 | * @inode: An inode to create the journal in |
1083 | * | |
f7f4bccb | 1084 | * jbd2_journal_init_inode creates a journal which maps an on-disk inode as |
470decc6 DK |
1085 | * the journal. The inode must exist already, must support bmap() and |
1086 | * must have all data blocks preallocated. | |
1087 | */ | |
f7f4bccb | 1088 | journal_t * jbd2_journal_init_inode (struct inode *inode) |
470decc6 DK |
1089 | { |
1090 | struct buffer_head *bh; | |
1091 | journal_t *journal = journal_init_common(); | |
05496769 | 1092 | char *p; |
470decc6 DK |
1093 | int err; |
1094 | int n; | |
18eba7aa | 1095 | unsigned long long blocknr; |
470decc6 DK |
1096 | |
1097 | if (!journal) | |
1098 | return NULL; | |
1099 | ||
1100 | journal->j_dev = journal->j_fs_dev = inode->i_sb->s_bdev; | |
1101 | journal->j_inode = inode; | |
05496769 TT |
1102 | bdevname(journal->j_dev, journal->j_devname); |
1103 | p = journal->j_devname; | |
1104 | while ((p = strchr(p, '/'))) | |
1105 | *p = '!'; | |
1106 | p = journal->j_devname + strlen(journal->j_devname); | |
1107 | sprintf(p, ":%lu", journal->j_inode->i_ino); | |
470decc6 DK |
1108 | jbd_debug(1, |
1109 | "journal %p: inode %s/%ld, size %Ld, bits %d, blksize %ld\n", | |
1110 | journal, inode->i_sb->s_id, inode->i_ino, | |
1111 | (long long) inode->i_size, | |
1112 | inode->i_sb->s_blocksize_bits, inode->i_sb->s_blocksize); | |
1113 | ||
1114 | journal->j_maxlen = inode->i_size >> inode->i_sb->s_blocksize_bits; | |
1115 | journal->j_blocksize = inode->i_sb->s_blocksize; | |
8e85fb3f | 1116 | jbd2_stats_proc_init(journal); |
470decc6 DK |
1117 | |
1118 | /* journal descriptor can store up to n blocks -bzzz */ | |
1119 | n = journal->j_blocksize / sizeof(journal_block_tag_t); | |
1120 | journal->j_wbufsize = n; | |
1121 | journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL); | |
1122 | if (!journal->j_wbuf) { | |
1123 | printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n", | |
329d291f | 1124 | __func__); |
4b905671 | 1125 | goto out_err; |
470decc6 DK |
1126 | } |
1127 | ||
f7f4bccb | 1128 | err = jbd2_journal_bmap(journal, 0, &blocknr); |
470decc6 DK |
1129 | /* If that failed, give up */ |
1130 | if (err) { | |
1131 | printk(KERN_ERR "%s: Cannnot locate journal superblock\n", | |
329d291f | 1132 | __func__); |
4b905671 | 1133 | goto out_err; |
470decc6 DK |
1134 | } |
1135 | ||
1136 | bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); | |
4b905671 JK |
1137 | if (!bh) { |
1138 | printk(KERN_ERR | |
1139 | "%s: Cannot get buffer for journal superblock\n", | |
1140 | __func__); | |
1141 | goto out_err; | |
1142 | } | |
470decc6 DK |
1143 | journal->j_sb_buffer = bh; |
1144 | journal->j_superblock = (journal_superblock_t *)bh->b_data; | |
1145 | ||
1146 | return journal; | |
4b905671 JK |
1147 | out_err: |
1148 | jbd2_stats_proc_exit(journal); | |
1149 | kfree(journal); | |
1150 | return NULL; | |
470decc6 DK |
1151 | } |
1152 | ||
1153 | /* | |
1154 | * If the journal init or create aborts, we need to mark the journal | |
1155 | * superblock as being NULL to prevent the journal destroy from writing | |
1156 | * back a bogus superblock. | |
1157 | */ | |
1158 | static void journal_fail_superblock (journal_t *journal) | |
1159 | { | |
1160 | struct buffer_head *bh = journal->j_sb_buffer; | |
1161 | brelse(bh); | |
1162 | journal->j_sb_buffer = NULL; | |
1163 | } | |
1164 | ||
1165 | /* | |
1166 | * Given a journal_t structure, initialise the various fields for | |
1167 | * startup of a new journaling session. We use this both when creating | |
1168 | * a journal, and after recovering an old journal to reset it for | |
1169 | * subsequent use. | |
1170 | */ | |
1171 | ||
1172 | static int journal_reset(journal_t *journal) | |
1173 | { | |
1174 | journal_superblock_t *sb = journal->j_superblock; | |
18eba7aa | 1175 | unsigned long long first, last; |
470decc6 DK |
1176 | |
1177 | first = be32_to_cpu(sb->s_first); | |
1178 | last = be32_to_cpu(sb->s_maxlen); | |
1179 | ||
1180 | journal->j_first = first; | |
1181 | journal->j_last = last; | |
1182 | ||
1183 | journal->j_head = first; | |
1184 | journal->j_tail = first; | |
1185 | journal->j_free = last - first; | |
1186 | ||
1187 | journal->j_tail_sequence = journal->j_transaction_sequence; | |
1188 | journal->j_commit_sequence = journal->j_transaction_sequence - 1; | |
1189 | journal->j_commit_request = journal->j_commit_sequence; | |
1190 | ||
1191 | journal->j_max_transaction_buffers = journal->j_maxlen / 4; | |
1192 | ||
1193 | /* Add the dynamic fields and write it to disk. */ | |
f7f4bccb | 1194 | jbd2_journal_update_superblock(journal, 1); |
97f06784 | 1195 | return jbd2_journal_start_thread(journal); |
470decc6 DK |
1196 | } |
1197 | ||
470decc6 | 1198 | /** |
f7f4bccb | 1199 | * void jbd2_journal_update_superblock() - Update journal sb on disk. |
470decc6 DK |
1200 | * @journal: The journal to update. |
1201 | * @wait: Set to '0' if you don't want to wait for IO completion. | |
1202 | * | |
1203 | * Update a journal's dynamic superblock fields and write it to disk, | |
1204 | * optionally waiting for the IO to complete. | |
1205 | */ | |
f7f4bccb | 1206 | void jbd2_journal_update_superblock(journal_t *journal, int wait) |
470decc6 DK |
1207 | { |
1208 | journal_superblock_t *sb = journal->j_superblock; | |
1209 | struct buffer_head *bh = journal->j_sb_buffer; | |
1210 | ||
1211 | /* | |
1212 | * As a special case, if the on-disk copy is already marked as needing | |
1213 | * no recovery (s_start == 0) and there are no outstanding transactions | |
1214 | * in the filesystem, then we can safely defer the superblock update | |
f7f4bccb | 1215 | * until the next commit by setting JBD2_FLUSHED. This avoids |
470decc6 DK |
1216 | * attempting a write to a potential-readonly device. |
1217 | */ | |
1218 | if (sb->s_start == 0 && journal->j_tail_sequence == | |
1219 | journal->j_transaction_sequence) { | |
1220 | jbd_debug(1,"JBD: Skipping superblock update on recovered sb " | |
1221 | "(start %ld, seq %d, errno %d)\n", | |
1222 | journal->j_tail, journal->j_tail_sequence, | |
1223 | journal->j_errno); | |
1224 | goto out; | |
1225 | } | |
1226 | ||
914258bf TT |
1227 | if (buffer_write_io_error(bh)) { |
1228 | /* | |
1229 | * Oh, dear. A previous attempt to write the journal | |
1230 | * superblock failed. This could happen because the | |
1231 | * USB device was yanked out. Or it could happen to | |
1232 | * be a transient write error and maybe the block will | |
1233 | * be remapped. Nothing we can do but to retry the | |
1234 | * write and hope for the best. | |
1235 | */ | |
1236 | printk(KERN_ERR "JBD2: previous I/O error detected " | |
1237 | "for journal superblock update for %s.\n", | |
1238 | journal->j_devname); | |
1239 | clear_buffer_write_io_error(bh); | |
1240 | set_buffer_uptodate(bh); | |
1241 | } | |
1242 | ||
470decc6 DK |
1243 | spin_lock(&journal->j_state_lock); |
1244 | jbd_debug(1,"JBD: updating superblock (start %ld, seq %d, errno %d)\n", | |
1245 | journal->j_tail, journal->j_tail_sequence, journal->j_errno); | |
1246 | ||
1247 | sb->s_sequence = cpu_to_be32(journal->j_tail_sequence); | |
1248 | sb->s_start = cpu_to_be32(journal->j_tail); | |
1249 | sb->s_errno = cpu_to_be32(journal->j_errno); | |
1250 | spin_unlock(&journal->j_state_lock); | |
1251 | ||
1252 | BUFFER_TRACE(bh, "marking dirty"); | |
1253 | mark_buffer_dirty(bh); | |
914258bf | 1254 | if (wait) { |
470decc6 | 1255 | sync_dirty_buffer(bh); |
914258bf TT |
1256 | if (buffer_write_io_error(bh)) { |
1257 | printk(KERN_ERR "JBD2: I/O error detected " | |
1258 | "when updating journal superblock for %s.\n", | |
1259 | journal->j_devname); | |
1260 | clear_buffer_write_io_error(bh); | |
1261 | set_buffer_uptodate(bh); | |
1262 | } | |
1263 | } else | |
470decc6 DK |
1264 | ll_rw_block(SWRITE, 1, &bh); |
1265 | ||
1266 | out: | |
1267 | /* If we have just flushed the log (by marking s_start==0), then | |
1268 | * any future commit will have to be careful to update the | |
1269 | * superblock again to re-record the true start of the log. */ | |
1270 | ||
1271 | spin_lock(&journal->j_state_lock); | |
1272 | if (sb->s_start) | |
f7f4bccb | 1273 | journal->j_flags &= ~JBD2_FLUSHED; |
470decc6 | 1274 | else |
f7f4bccb | 1275 | journal->j_flags |= JBD2_FLUSHED; |
470decc6 DK |
1276 | spin_unlock(&journal->j_state_lock); |
1277 | } | |
1278 | ||
1279 | /* | |
1280 | * Read the superblock for a given journal, performing initial | |
1281 | * validation of the format. | |
1282 | */ | |
1283 | ||
1284 | static int journal_get_superblock(journal_t *journal) | |
1285 | { | |
1286 | struct buffer_head *bh; | |
1287 | journal_superblock_t *sb; | |
1288 | int err = -EIO; | |
1289 | ||
1290 | bh = journal->j_sb_buffer; | |
1291 | ||
1292 | J_ASSERT(bh != NULL); | |
1293 | if (!buffer_uptodate(bh)) { | |
1294 | ll_rw_block(READ, 1, &bh); | |
1295 | wait_on_buffer(bh); | |
1296 | if (!buffer_uptodate(bh)) { | |
1297 | printk (KERN_ERR | |
1298 | "JBD: IO error reading journal superblock\n"); | |
1299 | goto out; | |
1300 | } | |
1301 | } | |
1302 | ||
1303 | sb = journal->j_superblock; | |
1304 | ||
1305 | err = -EINVAL; | |
1306 | ||
f7f4bccb | 1307 | if (sb->s_header.h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER) || |
470decc6 DK |
1308 | sb->s_blocksize != cpu_to_be32(journal->j_blocksize)) { |
1309 | printk(KERN_WARNING "JBD: no valid journal superblock found\n"); | |
1310 | goto out; | |
1311 | } | |
1312 | ||
1313 | switch(be32_to_cpu(sb->s_header.h_blocktype)) { | |
f7f4bccb | 1314 | case JBD2_SUPERBLOCK_V1: |
470decc6 DK |
1315 | journal->j_format_version = 1; |
1316 | break; | |
f7f4bccb | 1317 | case JBD2_SUPERBLOCK_V2: |
470decc6 DK |
1318 | journal->j_format_version = 2; |
1319 | break; | |
1320 | default: | |
1321 | printk(KERN_WARNING "JBD: unrecognised superblock format ID\n"); | |
1322 | goto out; | |
1323 | } | |
1324 | ||
1325 | if (be32_to_cpu(sb->s_maxlen) < journal->j_maxlen) | |
1326 | journal->j_maxlen = be32_to_cpu(sb->s_maxlen); | |
1327 | else if (be32_to_cpu(sb->s_maxlen) > journal->j_maxlen) { | |
1328 | printk (KERN_WARNING "JBD: journal file too short\n"); | |
1329 | goto out; | |
1330 | } | |
1331 | ||
1332 | return 0; | |
1333 | ||
1334 | out: | |
1335 | journal_fail_superblock(journal); | |
1336 | return err; | |
1337 | } | |
1338 | ||
1339 | /* | |
1340 | * Load the on-disk journal superblock and read the key fields into the | |
1341 | * journal_t. | |
1342 | */ | |
1343 | ||
1344 | static int load_superblock(journal_t *journal) | |
1345 | { | |
1346 | int err; | |
1347 | journal_superblock_t *sb; | |
1348 | ||
1349 | err = journal_get_superblock(journal); | |
1350 | if (err) | |
1351 | return err; | |
1352 | ||
1353 | sb = journal->j_superblock; | |
1354 | ||
1355 | journal->j_tail_sequence = be32_to_cpu(sb->s_sequence); | |
1356 | journal->j_tail = be32_to_cpu(sb->s_start); | |
1357 | journal->j_first = be32_to_cpu(sb->s_first); | |
1358 | journal->j_last = be32_to_cpu(sb->s_maxlen); | |
1359 | journal->j_errno = be32_to_cpu(sb->s_errno); | |
1360 | ||
1361 | return 0; | |
1362 | } | |
1363 | ||
1364 | ||
1365 | /** | |
f7f4bccb | 1366 | * int jbd2_journal_load() - Read journal from disk. |
470decc6 DK |
1367 | * @journal: Journal to act on. |
1368 | * | |
1369 | * Given a journal_t structure which tells us which disk blocks contain | |
1370 | * a journal, read the journal from disk to initialise the in-memory | |
1371 | * structures. | |
1372 | */ | |
f7f4bccb | 1373 | int jbd2_journal_load(journal_t *journal) |
470decc6 DK |
1374 | { |
1375 | int err; | |
1376 | journal_superblock_t *sb; | |
1377 | ||
1378 | err = load_superblock(journal); | |
1379 | if (err) | |
1380 | return err; | |
1381 | ||
1382 | sb = journal->j_superblock; | |
1383 | /* If this is a V2 superblock, then we have to check the | |
1384 | * features flags on it. */ | |
1385 | ||
1386 | if (journal->j_format_version >= 2) { | |
1387 | if ((sb->s_feature_ro_compat & | |
f7f4bccb | 1388 | ~cpu_to_be32(JBD2_KNOWN_ROCOMPAT_FEATURES)) || |
470decc6 | 1389 | (sb->s_feature_incompat & |
f7f4bccb | 1390 | ~cpu_to_be32(JBD2_KNOWN_INCOMPAT_FEATURES))) { |
470decc6 DK |
1391 | printk (KERN_WARNING |
1392 | "JBD: Unrecognised features on journal\n"); | |
1393 | return -EINVAL; | |
1394 | } | |
1395 | } | |
1396 | ||
470decc6 DK |
1397 | /* Let the recovery code check whether it needs to recover any |
1398 | * data from the journal. */ | |
f7f4bccb | 1399 | if (jbd2_journal_recover(journal)) |
470decc6 DK |
1400 | goto recovery_error; |
1401 | ||
1402 | /* OK, we've finished with the dynamic journal bits: | |
1403 | * reinitialise the dynamic contents of the superblock in memory | |
1404 | * and reset them on disk. */ | |
1405 | if (journal_reset(journal)) | |
1406 | goto recovery_error; | |
1407 | ||
f7f4bccb MC |
1408 | journal->j_flags &= ~JBD2_ABORT; |
1409 | journal->j_flags |= JBD2_LOADED; | |
470decc6 DK |
1410 | return 0; |
1411 | ||
1412 | recovery_error: | |
1413 | printk (KERN_WARNING "JBD: recovery failed\n"); | |
1414 | return -EIO; | |
1415 | } | |
1416 | ||
1417 | /** | |
f7f4bccb | 1418 | * void jbd2_journal_destroy() - Release a journal_t structure. |
470decc6 DK |
1419 | * @journal: Journal to act on. |
1420 | * | |
1421 | * Release a journal_t structure once it is no longer in use by the | |
1422 | * journaled object. | |
44519faf | 1423 | * Return <0 if we couldn't clean up the journal. |
470decc6 | 1424 | */ |
44519faf | 1425 | int jbd2_journal_destroy(journal_t *journal) |
470decc6 | 1426 | { |
44519faf HK |
1427 | int err = 0; |
1428 | ||
470decc6 DK |
1429 | /* Wait for the commit thread to wake up and die. */ |
1430 | journal_kill_thread(journal); | |
1431 | ||
1432 | /* Force a final log commit */ | |
1433 | if (journal->j_running_transaction) | |
f7f4bccb | 1434 | jbd2_journal_commit_transaction(journal); |
470decc6 DK |
1435 | |
1436 | /* Force any old transactions to disk */ | |
1437 | ||
1438 | /* Totally anal locking here... */ | |
1439 | spin_lock(&journal->j_list_lock); | |
1440 | while (journal->j_checkpoint_transactions != NULL) { | |
1441 | spin_unlock(&journal->j_list_lock); | |
1a0d3786 | 1442 | mutex_lock(&journal->j_checkpoint_mutex); |
f7f4bccb | 1443 | jbd2_log_do_checkpoint(journal); |
1a0d3786 | 1444 | mutex_unlock(&journal->j_checkpoint_mutex); |
470decc6 DK |
1445 | spin_lock(&journal->j_list_lock); |
1446 | } | |
1447 | ||
1448 | J_ASSERT(journal->j_running_transaction == NULL); | |
1449 | J_ASSERT(journal->j_committing_transaction == NULL); | |
1450 | J_ASSERT(journal->j_checkpoint_transactions == NULL); | |
1451 | spin_unlock(&journal->j_list_lock); | |
1452 | ||
470decc6 | 1453 | if (journal->j_sb_buffer) { |
44519faf HK |
1454 | if (!is_journal_aborted(journal)) { |
1455 | /* We can now mark the journal as empty. */ | |
1456 | journal->j_tail = 0; | |
1457 | journal->j_tail_sequence = | |
1458 | ++journal->j_transaction_sequence; | |
1459 | jbd2_journal_update_superblock(journal, 1); | |
1460 | } else { | |
1461 | err = -EIO; | |
1462 | } | |
470decc6 DK |
1463 | brelse(journal->j_sb_buffer); |
1464 | } | |
1465 | ||
8e85fb3f JL |
1466 | if (journal->j_proc_entry) |
1467 | jbd2_stats_proc_exit(journal); | |
470decc6 DK |
1468 | if (journal->j_inode) |
1469 | iput(journal->j_inode); | |
1470 | if (journal->j_revoke) | |
f7f4bccb | 1471 | jbd2_journal_destroy_revoke(journal); |
470decc6 DK |
1472 | kfree(journal->j_wbuf); |
1473 | kfree(journal); | |
44519faf HK |
1474 | |
1475 | return err; | |
470decc6 DK |
1476 | } |
1477 | ||
1478 | ||
1479 | /** | |
f7f4bccb | 1480 | *int jbd2_journal_check_used_features () - Check if features specified are used. |
470decc6 DK |
1481 | * @journal: Journal to check. |
1482 | * @compat: bitmask of compatible features | |
1483 | * @ro: bitmask of features that force read-only mount | |
1484 | * @incompat: bitmask of incompatible features | |
1485 | * | |
1486 | * Check whether the journal uses all of a given set of | |
1487 | * features. Return true (non-zero) if it does. | |
1488 | **/ | |
1489 | ||
f7f4bccb | 1490 | int jbd2_journal_check_used_features (journal_t *journal, unsigned long compat, |
470decc6 DK |
1491 | unsigned long ro, unsigned long incompat) |
1492 | { | |
1493 | journal_superblock_t *sb; | |
1494 | ||
1495 | if (!compat && !ro && !incompat) | |
1496 | return 1; | |
1497 | if (journal->j_format_version == 1) | |
1498 | return 0; | |
1499 | ||
1500 | sb = journal->j_superblock; | |
1501 | ||
1502 | if (((be32_to_cpu(sb->s_feature_compat) & compat) == compat) && | |
1503 | ((be32_to_cpu(sb->s_feature_ro_compat) & ro) == ro) && | |
1504 | ((be32_to_cpu(sb->s_feature_incompat) & incompat) == incompat)) | |
1505 | return 1; | |
1506 | ||
1507 | return 0; | |
1508 | } | |
1509 | ||
1510 | /** | |
f7f4bccb | 1511 | * int jbd2_journal_check_available_features() - Check feature set in journalling layer |
470decc6 DK |
1512 | * @journal: Journal to check. |
1513 | * @compat: bitmask of compatible features | |
1514 | * @ro: bitmask of features that force read-only mount | |
1515 | * @incompat: bitmask of incompatible features | |
1516 | * | |
1517 | * Check whether the journaling code supports the use of | |
1518 | * all of a given set of features on this journal. Return true | |
1519 | * (non-zero) if it can. */ | |
1520 | ||
f7f4bccb | 1521 | int jbd2_journal_check_available_features (journal_t *journal, unsigned long compat, |
470decc6 DK |
1522 | unsigned long ro, unsigned long incompat) |
1523 | { | |
1524 | journal_superblock_t *sb; | |
1525 | ||
1526 | if (!compat && !ro && !incompat) | |
1527 | return 1; | |
1528 | ||
1529 | sb = journal->j_superblock; | |
1530 | ||
1531 | /* We can support any known requested features iff the | |
1532 | * superblock is in version 2. Otherwise we fail to support any | |
1533 | * extended sb features. */ | |
1534 | ||
1535 | if (journal->j_format_version != 2) | |
1536 | return 0; | |
1537 | ||
f7f4bccb MC |
1538 | if ((compat & JBD2_KNOWN_COMPAT_FEATURES) == compat && |
1539 | (ro & JBD2_KNOWN_ROCOMPAT_FEATURES) == ro && | |
1540 | (incompat & JBD2_KNOWN_INCOMPAT_FEATURES) == incompat) | |
470decc6 DK |
1541 | return 1; |
1542 | ||
1543 | return 0; | |
1544 | } | |
1545 | ||
1546 | /** | |
f7f4bccb | 1547 | * int jbd2_journal_set_features () - Mark a given journal feature in the superblock |
470decc6 DK |
1548 | * @journal: Journal to act on. |
1549 | * @compat: bitmask of compatible features | |
1550 | * @ro: bitmask of features that force read-only mount | |
1551 | * @incompat: bitmask of incompatible features | |
1552 | * | |
1553 | * Mark a given journal feature as present on the | |
1554 | * superblock. Returns true if the requested features could be set. | |
1555 | * | |
1556 | */ | |
1557 | ||
f7f4bccb | 1558 | int jbd2_journal_set_features (journal_t *journal, unsigned long compat, |
470decc6 DK |
1559 | unsigned long ro, unsigned long incompat) |
1560 | { | |
1561 | journal_superblock_t *sb; | |
1562 | ||
f7f4bccb | 1563 | if (jbd2_journal_check_used_features(journal, compat, ro, incompat)) |
470decc6 DK |
1564 | return 1; |
1565 | ||
f7f4bccb | 1566 | if (!jbd2_journal_check_available_features(journal, compat, ro, incompat)) |
470decc6 DK |
1567 | return 0; |
1568 | ||
1569 | jbd_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n", | |
1570 | compat, ro, incompat); | |
1571 | ||
1572 | sb = journal->j_superblock; | |
1573 | ||
1574 | sb->s_feature_compat |= cpu_to_be32(compat); | |
1575 | sb->s_feature_ro_compat |= cpu_to_be32(ro); | |
1576 | sb->s_feature_incompat |= cpu_to_be32(incompat); | |
1577 | ||
1578 | return 1; | |
1579 | } | |
1580 | ||
818d276c GS |
1581 | /* |
1582 | * jbd2_journal_clear_features () - Clear a given journal feature in the | |
1583 | * superblock | |
1584 | * @journal: Journal to act on. | |
1585 | * @compat: bitmask of compatible features | |
1586 | * @ro: bitmask of features that force read-only mount | |
1587 | * @incompat: bitmask of incompatible features | |
1588 | * | |
1589 | * Clear a given journal feature as present on the | |
1590 | * superblock. | |
1591 | */ | |
1592 | void jbd2_journal_clear_features(journal_t *journal, unsigned long compat, | |
1593 | unsigned long ro, unsigned long incompat) | |
1594 | { | |
1595 | journal_superblock_t *sb; | |
1596 | ||
1597 | jbd_debug(1, "Clear features 0x%lx/0x%lx/0x%lx\n", | |
1598 | compat, ro, incompat); | |
1599 | ||
1600 | sb = journal->j_superblock; | |
1601 | ||
1602 | sb->s_feature_compat &= ~cpu_to_be32(compat); | |
1603 | sb->s_feature_ro_compat &= ~cpu_to_be32(ro); | |
1604 | sb->s_feature_incompat &= ~cpu_to_be32(incompat); | |
1605 | } | |
1606 | EXPORT_SYMBOL(jbd2_journal_clear_features); | |
470decc6 DK |
1607 | |
1608 | /** | |
f7f4bccb | 1609 | * int jbd2_journal_update_format () - Update on-disk journal structure. |
470decc6 DK |
1610 | * @journal: Journal to act on. |
1611 | * | |
1612 | * Given an initialised but unloaded journal struct, poke about in the | |
1613 | * on-disk structure to update it to the most recent supported version. | |
1614 | */ | |
f7f4bccb | 1615 | int jbd2_journal_update_format (journal_t *journal) |
470decc6 DK |
1616 | { |
1617 | journal_superblock_t *sb; | |
1618 | int err; | |
1619 | ||
1620 | err = journal_get_superblock(journal); | |
1621 | if (err) | |
1622 | return err; | |
1623 | ||
1624 | sb = journal->j_superblock; | |
1625 | ||
1626 | switch (be32_to_cpu(sb->s_header.h_blocktype)) { | |
f7f4bccb | 1627 | case JBD2_SUPERBLOCK_V2: |
470decc6 | 1628 | return 0; |
f7f4bccb | 1629 | case JBD2_SUPERBLOCK_V1: |
470decc6 DK |
1630 | return journal_convert_superblock_v1(journal, sb); |
1631 | default: | |
1632 | break; | |
1633 | } | |
1634 | return -EINVAL; | |
1635 | } | |
1636 | ||
1637 | static int journal_convert_superblock_v1(journal_t *journal, | |
1638 | journal_superblock_t *sb) | |
1639 | { | |
1640 | int offset, blocksize; | |
1641 | struct buffer_head *bh; | |
1642 | ||
1643 | printk(KERN_WARNING | |
1644 | "JBD: Converting superblock from version 1 to 2.\n"); | |
1645 | ||
1646 | /* Pre-initialise new fields to zero */ | |
1647 | offset = ((char *) &(sb->s_feature_compat)) - ((char *) sb); | |
1648 | blocksize = be32_to_cpu(sb->s_blocksize); | |
1649 | memset(&sb->s_feature_compat, 0, blocksize-offset); | |
1650 | ||
1651 | sb->s_nr_users = cpu_to_be32(1); | |
f7f4bccb | 1652 | sb->s_header.h_blocktype = cpu_to_be32(JBD2_SUPERBLOCK_V2); |
470decc6 DK |
1653 | journal->j_format_version = 2; |
1654 | ||
1655 | bh = journal->j_sb_buffer; | |
1656 | BUFFER_TRACE(bh, "marking dirty"); | |
1657 | mark_buffer_dirty(bh); | |
1658 | sync_dirty_buffer(bh); | |
1659 | return 0; | |
1660 | } | |
1661 | ||
1662 | ||
1663 | /** | |
f7f4bccb | 1664 | * int jbd2_journal_flush () - Flush journal |
470decc6 DK |
1665 | * @journal: Journal to act on. |
1666 | * | |
1667 | * Flush all data for a given journal to disk and empty the journal. | |
1668 | * Filesystems can use this when remounting readonly to ensure that | |
1669 | * recovery does not need to happen on remount. | |
1670 | */ | |
1671 | ||
f7f4bccb | 1672 | int jbd2_journal_flush(journal_t *journal) |
470decc6 DK |
1673 | { |
1674 | int err = 0; | |
1675 | transaction_t *transaction = NULL; | |
1676 | unsigned long old_tail; | |
1677 | ||
1678 | spin_lock(&journal->j_state_lock); | |
1679 | ||
1680 | /* Force everything buffered to the log... */ | |
1681 | if (journal->j_running_transaction) { | |
1682 | transaction = journal->j_running_transaction; | |
f7f4bccb | 1683 | __jbd2_log_start_commit(journal, transaction->t_tid); |
470decc6 DK |
1684 | } else if (journal->j_committing_transaction) |
1685 | transaction = journal->j_committing_transaction; | |
1686 | ||
1687 | /* Wait for the log commit to complete... */ | |
1688 | if (transaction) { | |
1689 | tid_t tid = transaction->t_tid; | |
1690 | ||
1691 | spin_unlock(&journal->j_state_lock); | |
f7f4bccb | 1692 | jbd2_log_wait_commit(journal, tid); |
470decc6 DK |
1693 | } else { |
1694 | spin_unlock(&journal->j_state_lock); | |
1695 | } | |
1696 | ||
1697 | /* ...and flush everything in the log out to disk. */ | |
1698 | spin_lock(&journal->j_list_lock); | |
1699 | while (!err && journal->j_checkpoint_transactions != NULL) { | |
1700 | spin_unlock(&journal->j_list_lock); | |
44519faf | 1701 | mutex_lock(&journal->j_checkpoint_mutex); |
f7f4bccb | 1702 | err = jbd2_log_do_checkpoint(journal); |
44519faf | 1703 | mutex_unlock(&journal->j_checkpoint_mutex); |
470decc6 DK |
1704 | spin_lock(&journal->j_list_lock); |
1705 | } | |
1706 | spin_unlock(&journal->j_list_lock); | |
44519faf HK |
1707 | |
1708 | if (is_journal_aborted(journal)) | |
1709 | return -EIO; | |
1710 | ||
f7f4bccb | 1711 | jbd2_cleanup_journal_tail(journal); |
470decc6 DK |
1712 | |
1713 | /* Finally, mark the journal as really needing no recovery. | |
1714 | * This sets s_start==0 in the underlying superblock, which is | |
1715 | * the magic code for a fully-recovered superblock. Any future | |
1716 | * commits of data to the journal will restore the current | |
1717 | * s_start value. */ | |
1718 | spin_lock(&journal->j_state_lock); | |
1719 | old_tail = journal->j_tail; | |
1720 | journal->j_tail = 0; | |
1721 | spin_unlock(&journal->j_state_lock); | |
f7f4bccb | 1722 | jbd2_journal_update_superblock(journal, 1); |
470decc6 DK |
1723 | spin_lock(&journal->j_state_lock); |
1724 | journal->j_tail = old_tail; | |
1725 | ||
1726 | J_ASSERT(!journal->j_running_transaction); | |
1727 | J_ASSERT(!journal->j_committing_transaction); | |
1728 | J_ASSERT(!journal->j_checkpoint_transactions); | |
1729 | J_ASSERT(journal->j_head == journal->j_tail); | |
1730 | J_ASSERT(journal->j_tail_sequence == journal->j_transaction_sequence); | |
1731 | spin_unlock(&journal->j_state_lock); | |
44519faf | 1732 | return 0; |
470decc6 DK |
1733 | } |
1734 | ||
1735 | /** | |
f7f4bccb | 1736 | * int jbd2_journal_wipe() - Wipe journal contents |
470decc6 DK |
1737 | * @journal: Journal to act on. |
1738 | * @write: flag (see below) | |
1739 | * | |
1740 | * Wipe out all of the contents of a journal, safely. This will produce | |
1741 | * a warning if the journal contains any valid recovery information. | |
f7f4bccb | 1742 | * Must be called between journal_init_*() and jbd2_journal_load(). |
470decc6 DK |
1743 | * |
1744 | * If 'write' is non-zero, then we wipe out the journal on disk; otherwise | |
1745 | * we merely suppress recovery. | |
1746 | */ | |
1747 | ||
f7f4bccb | 1748 | int jbd2_journal_wipe(journal_t *journal, int write) |
470decc6 DK |
1749 | { |
1750 | journal_superblock_t *sb; | |
1751 | int err = 0; | |
1752 | ||
f7f4bccb | 1753 | J_ASSERT (!(journal->j_flags & JBD2_LOADED)); |
470decc6 DK |
1754 | |
1755 | err = load_superblock(journal); | |
1756 | if (err) | |
1757 | return err; | |
1758 | ||
1759 | sb = journal->j_superblock; | |
1760 | ||
1761 | if (!journal->j_tail) | |
1762 | goto no_recovery; | |
1763 | ||
1764 | printk (KERN_WARNING "JBD: %s recovery information on journal\n", | |
1765 | write ? "Clearing" : "Ignoring"); | |
1766 | ||
f7f4bccb | 1767 | err = jbd2_journal_skip_recovery(journal); |
470decc6 | 1768 | if (write) |
f7f4bccb | 1769 | jbd2_journal_update_superblock(journal, 1); |
470decc6 DK |
1770 | |
1771 | no_recovery: | |
1772 | return err; | |
1773 | } | |
1774 | ||
470decc6 DK |
1775 | /* |
1776 | * Journal abort has very specific semantics, which we describe | |
1777 | * for journal abort. | |
1778 | * | |
1779 | * Two internal function, which provide abort to te jbd layer | |
1780 | * itself are here. | |
1781 | */ | |
1782 | ||
1783 | /* | |
1784 | * Quick version for internal journal use (doesn't lock the journal). | |
1785 | * Aborts hard --- we mark the abort as occurred, but do _nothing_ else, | |
1786 | * and don't attempt to make any other journal updates. | |
1787 | */ | |
f7f4bccb | 1788 | void __jbd2_journal_abort_hard(journal_t *journal) |
470decc6 DK |
1789 | { |
1790 | transaction_t *transaction; | |
470decc6 | 1791 | |
f7f4bccb | 1792 | if (journal->j_flags & JBD2_ABORT) |
470decc6 DK |
1793 | return; |
1794 | ||
1795 | printk(KERN_ERR "Aborting journal on device %s.\n", | |
05496769 | 1796 | journal->j_devname); |
470decc6 DK |
1797 | |
1798 | spin_lock(&journal->j_state_lock); | |
f7f4bccb | 1799 | journal->j_flags |= JBD2_ABORT; |
470decc6 DK |
1800 | transaction = journal->j_running_transaction; |
1801 | if (transaction) | |
f7f4bccb | 1802 | __jbd2_log_start_commit(journal, transaction->t_tid); |
470decc6 DK |
1803 | spin_unlock(&journal->j_state_lock); |
1804 | } | |
1805 | ||
1806 | /* Soft abort: record the abort error status in the journal superblock, | |
1807 | * but don't do any other IO. */ | |
1808 | static void __journal_abort_soft (journal_t *journal, int errno) | |
1809 | { | |
f7f4bccb | 1810 | if (journal->j_flags & JBD2_ABORT) |
470decc6 DK |
1811 | return; |
1812 | ||
1813 | if (!journal->j_errno) | |
1814 | journal->j_errno = errno; | |
1815 | ||
f7f4bccb | 1816 | __jbd2_journal_abort_hard(journal); |
470decc6 DK |
1817 | |
1818 | if (errno) | |
f7f4bccb | 1819 | jbd2_journal_update_superblock(journal, 1); |
470decc6 DK |
1820 | } |
1821 | ||
1822 | /** | |
f7f4bccb | 1823 | * void jbd2_journal_abort () - Shutdown the journal immediately. |
470decc6 DK |
1824 | * @journal: the journal to shutdown. |
1825 | * @errno: an error number to record in the journal indicating | |
1826 | * the reason for the shutdown. | |
1827 | * | |
1828 | * Perform a complete, immediate shutdown of the ENTIRE | |
1829 | * journal (not of a single transaction). This operation cannot be | |
1830 | * undone without closing and reopening the journal. | |
1831 | * | |
f7f4bccb | 1832 | * The jbd2_journal_abort function is intended to support higher level error |
470decc6 DK |
1833 | * recovery mechanisms such as the ext2/ext3 remount-readonly error |
1834 | * mode. | |
1835 | * | |
1836 | * Journal abort has very specific semantics. Any existing dirty, | |
1837 | * unjournaled buffers in the main filesystem will still be written to | |
1838 | * disk by bdflush, but the journaling mechanism will be suspended | |
1839 | * immediately and no further transaction commits will be honoured. | |
1840 | * | |
1841 | * Any dirty, journaled buffers will be written back to disk without | |
1842 | * hitting the journal. Atomicity cannot be guaranteed on an aborted | |
1843 | * filesystem, but we _do_ attempt to leave as much data as possible | |
1844 | * behind for fsck to use for cleanup. | |
1845 | * | |
1846 | * Any attempt to get a new transaction handle on a journal which is in | |
1847 | * ABORT state will just result in an -EROFS error return. A | |
f7f4bccb | 1848 | * jbd2_journal_stop on an existing handle will return -EIO if we have |
470decc6 DK |
1849 | * entered abort state during the update. |
1850 | * | |
1851 | * Recursive transactions are not disturbed by journal abort until the | |
f7f4bccb | 1852 | * final jbd2_journal_stop, which will receive the -EIO error. |
470decc6 | 1853 | * |
f7f4bccb | 1854 | * Finally, the jbd2_journal_abort call allows the caller to supply an errno |
470decc6 DK |
1855 | * which will be recorded (if possible) in the journal superblock. This |
1856 | * allows a client to record failure conditions in the middle of a | |
1857 | * transaction without having to complete the transaction to record the | |
1858 | * failure to disk. ext3_error, for example, now uses this | |
1859 | * functionality. | |
1860 | * | |
1861 | * Errors which originate from within the journaling layer will NOT | |
1862 | * supply an errno; a null errno implies that absolutely no further | |
1863 | * writes are done to the journal (unless there are any already in | |
1864 | * progress). | |
1865 | * | |
1866 | */ | |
1867 | ||
f7f4bccb | 1868 | void jbd2_journal_abort(journal_t *journal, int errno) |
470decc6 DK |
1869 | { |
1870 | __journal_abort_soft(journal, errno); | |
1871 | } | |
1872 | ||
1873 | /** | |
f7f4bccb | 1874 | * int jbd2_journal_errno () - returns the journal's error state. |
470decc6 DK |
1875 | * @journal: journal to examine. |
1876 | * | |
f7f4bccb | 1877 | * This is the errno numbet set with jbd2_journal_abort(), the last |
470decc6 DK |
1878 | * time the journal was mounted - if the journal was stopped |
1879 | * without calling abort this will be 0. | |
1880 | * | |
1881 | * If the journal has been aborted on this mount time -EROFS will | |
1882 | * be returned. | |
1883 | */ | |
f7f4bccb | 1884 | int jbd2_journal_errno(journal_t *journal) |
470decc6 DK |
1885 | { |
1886 | int err; | |
1887 | ||
1888 | spin_lock(&journal->j_state_lock); | |
f7f4bccb | 1889 | if (journal->j_flags & JBD2_ABORT) |
470decc6 DK |
1890 | err = -EROFS; |
1891 | else | |
1892 | err = journal->j_errno; | |
1893 | spin_unlock(&journal->j_state_lock); | |
1894 | return err; | |
1895 | } | |
1896 | ||
1897 | /** | |
f7f4bccb | 1898 | * int jbd2_journal_clear_err () - clears the journal's error state |
470decc6 DK |
1899 | * @journal: journal to act on. |
1900 | * | |
1901 | * An error must be cleared or Acked to take a FS out of readonly | |
1902 | * mode. | |
1903 | */ | |
f7f4bccb | 1904 | int jbd2_journal_clear_err(journal_t *journal) |
470decc6 DK |
1905 | { |
1906 | int err = 0; | |
1907 | ||
1908 | spin_lock(&journal->j_state_lock); | |
f7f4bccb | 1909 | if (journal->j_flags & JBD2_ABORT) |
470decc6 DK |
1910 | err = -EROFS; |
1911 | else | |
1912 | journal->j_errno = 0; | |
1913 | spin_unlock(&journal->j_state_lock); | |
1914 | return err; | |
1915 | } | |
1916 | ||
1917 | /** | |
f7f4bccb | 1918 | * void jbd2_journal_ack_err() - Ack journal err. |
470decc6 DK |
1919 | * @journal: journal to act on. |
1920 | * | |
1921 | * An error must be cleared or Acked to take a FS out of readonly | |
1922 | * mode. | |
1923 | */ | |
f7f4bccb | 1924 | void jbd2_journal_ack_err(journal_t *journal) |
470decc6 DK |
1925 | { |
1926 | spin_lock(&journal->j_state_lock); | |
1927 | if (journal->j_errno) | |
f7f4bccb | 1928 | journal->j_flags |= JBD2_ACK_ERR; |
470decc6 DK |
1929 | spin_unlock(&journal->j_state_lock); |
1930 | } | |
1931 | ||
f7f4bccb | 1932 | int jbd2_journal_blocks_per_page(struct inode *inode) |
470decc6 DK |
1933 | { |
1934 | return 1 << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits); | |
1935 | } | |
1936 | ||
b517bea1 ZB |
1937 | /* |
1938 | * helper functions to deal with 32 or 64bit block numbers. | |
1939 | */ | |
1940 | size_t journal_tag_bytes(journal_t *journal) | |
1941 | { | |
1942 | if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT)) | |
cd02ff0b | 1943 | return JBD2_TAG_SIZE64; |
b517bea1 | 1944 | else |
cd02ff0b | 1945 | return JBD2_TAG_SIZE32; |
b517bea1 ZB |
1946 | } |
1947 | ||
470decc6 DK |
1948 | /* |
1949 | * Journal_head storage management | |
1950 | */ | |
e18b890b | 1951 | static struct kmem_cache *jbd2_journal_head_cache; |
e23291b9 | 1952 | #ifdef CONFIG_JBD2_DEBUG |
470decc6 DK |
1953 | static atomic_t nr_journal_heads = ATOMIC_INIT(0); |
1954 | #endif | |
1955 | ||
f7f4bccb | 1956 | static int journal_init_jbd2_journal_head_cache(void) |
470decc6 DK |
1957 | { |
1958 | int retval; | |
1959 | ||
1076d17a | 1960 | J_ASSERT(jbd2_journal_head_cache == NULL); |
a920e941 | 1961 | jbd2_journal_head_cache = kmem_cache_create("jbd2_journal_head", |
470decc6 DK |
1962 | sizeof(struct journal_head), |
1963 | 0, /* offset */ | |
77160957 | 1964 | SLAB_TEMPORARY, /* flags */ |
20c2df83 | 1965 | NULL); /* ctor */ |
470decc6 | 1966 | retval = 0; |
1076d17a | 1967 | if (!jbd2_journal_head_cache) { |
470decc6 DK |
1968 | retval = -ENOMEM; |
1969 | printk(KERN_EMERG "JBD: no memory for journal_head cache\n"); | |
1970 | } | |
1971 | return retval; | |
1972 | } | |
1973 | ||
f7f4bccb | 1974 | static void jbd2_journal_destroy_jbd2_journal_head_cache(void) |
470decc6 | 1975 | { |
8a9362eb DG |
1976 | if (jbd2_journal_head_cache) { |
1977 | kmem_cache_destroy(jbd2_journal_head_cache); | |
1978 | jbd2_journal_head_cache = NULL; | |
1979 | } | |
470decc6 DK |
1980 | } |
1981 | ||
1982 | /* | |
1983 | * journal_head splicing and dicing | |
1984 | */ | |
1985 | static struct journal_head *journal_alloc_journal_head(void) | |
1986 | { | |
1987 | struct journal_head *ret; | |
1988 | static unsigned long last_warning; | |
1989 | ||
e23291b9 | 1990 | #ifdef CONFIG_JBD2_DEBUG |
470decc6 DK |
1991 | atomic_inc(&nr_journal_heads); |
1992 | #endif | |
f7f4bccb | 1993 | ret = kmem_cache_alloc(jbd2_journal_head_cache, GFP_NOFS); |
1076d17a | 1994 | if (!ret) { |
470decc6 DK |
1995 | jbd_debug(1, "out of memory for journal_head\n"); |
1996 | if (time_after(jiffies, last_warning + 5*HZ)) { | |
1997 | printk(KERN_NOTICE "ENOMEM in %s, retrying.\n", | |
329d291f | 1998 | __func__); |
470decc6 DK |
1999 | last_warning = jiffies; |
2000 | } | |
1076d17a | 2001 | while (!ret) { |
470decc6 | 2002 | yield(); |
f7f4bccb | 2003 | ret = kmem_cache_alloc(jbd2_journal_head_cache, GFP_NOFS); |
470decc6 DK |
2004 | } |
2005 | } | |
2006 | return ret; | |
2007 | } | |
2008 | ||
2009 | static void journal_free_journal_head(struct journal_head *jh) | |
2010 | { | |
e23291b9 | 2011 | #ifdef CONFIG_JBD2_DEBUG |
470decc6 | 2012 | atomic_dec(&nr_journal_heads); |
cd02ff0b | 2013 | memset(jh, JBD2_POISON_FREE, sizeof(*jh)); |
470decc6 | 2014 | #endif |
f7f4bccb | 2015 | kmem_cache_free(jbd2_journal_head_cache, jh); |
470decc6 DK |
2016 | } |
2017 | ||
2018 | /* | |
2019 | * A journal_head is attached to a buffer_head whenever JBD has an | |
2020 | * interest in the buffer. | |
2021 | * | |
2022 | * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit | |
2023 | * is set. This bit is tested in core kernel code where we need to take | |
2024 | * JBD-specific actions. Testing the zeroness of ->b_private is not reliable | |
2025 | * there. | |
2026 | * | |
2027 | * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one. | |
2028 | * | |
2029 | * When a buffer has its BH_JBD bit set it is immune from being released by | |
2030 | * core kernel code, mainly via ->b_count. | |
2031 | * | |
2032 | * A journal_head may be detached from its buffer_head when the journal_head's | |
2033 | * b_transaction, b_cp_transaction and b_next_transaction pointers are NULL. | |
f7f4bccb | 2034 | * Various places in JBD call jbd2_journal_remove_journal_head() to indicate that the |
470decc6 DK |
2035 | * journal_head can be dropped if needed. |
2036 | * | |
2037 | * Various places in the kernel want to attach a journal_head to a buffer_head | |
2038 | * _before_ attaching the journal_head to a transaction. To protect the | |
f7f4bccb | 2039 | * journal_head in this situation, jbd2_journal_add_journal_head elevates the |
470decc6 | 2040 | * journal_head's b_jcount refcount by one. The caller must call |
f7f4bccb | 2041 | * jbd2_journal_put_journal_head() to undo this. |
470decc6 DK |
2042 | * |
2043 | * So the typical usage would be: | |
2044 | * | |
2045 | * (Attach a journal_head if needed. Increments b_jcount) | |
f7f4bccb | 2046 | * struct journal_head *jh = jbd2_journal_add_journal_head(bh); |
470decc6 DK |
2047 | * ... |
2048 | * jh->b_transaction = xxx; | |
f7f4bccb | 2049 | * jbd2_journal_put_journal_head(jh); |
470decc6 DK |
2050 | * |
2051 | * Now, the journal_head's b_jcount is zero, but it is safe from being released | |
2052 | * because it has a non-zero b_transaction. | |
2053 | */ | |
2054 | ||
2055 | /* | |
2056 | * Give a buffer_head a journal_head. | |
2057 | * | |
2058 | * Doesn't need the journal lock. | |
2059 | * May sleep. | |
2060 | */ | |
f7f4bccb | 2061 | struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh) |
470decc6 DK |
2062 | { |
2063 | struct journal_head *jh; | |
2064 | struct journal_head *new_jh = NULL; | |
2065 | ||
2066 | repeat: | |
2067 | if (!buffer_jbd(bh)) { | |
2068 | new_jh = journal_alloc_journal_head(); | |
2069 | memset(new_jh, 0, sizeof(*new_jh)); | |
2070 | } | |
2071 | ||
2072 | jbd_lock_bh_journal_head(bh); | |
2073 | if (buffer_jbd(bh)) { | |
2074 | jh = bh2jh(bh); | |
2075 | } else { | |
2076 | J_ASSERT_BH(bh, | |
2077 | (atomic_read(&bh->b_count) > 0) || | |
2078 | (bh->b_page && bh->b_page->mapping)); | |
2079 | ||
2080 | if (!new_jh) { | |
2081 | jbd_unlock_bh_journal_head(bh); | |
2082 | goto repeat; | |
2083 | } | |
2084 | ||
2085 | jh = new_jh; | |
2086 | new_jh = NULL; /* We consumed it */ | |
2087 | set_buffer_jbd(bh); | |
2088 | bh->b_private = jh; | |
2089 | jh->b_bh = bh; | |
2090 | get_bh(bh); | |
2091 | BUFFER_TRACE(bh, "added journal_head"); | |
2092 | } | |
2093 | jh->b_jcount++; | |
2094 | jbd_unlock_bh_journal_head(bh); | |
2095 | if (new_jh) | |
2096 | journal_free_journal_head(new_jh); | |
2097 | return bh->b_private; | |
2098 | } | |
2099 | ||
2100 | /* | |
2101 | * Grab a ref against this buffer_head's journal_head. If it ended up not | |
2102 | * having a journal_head, return NULL | |
2103 | */ | |
f7f4bccb | 2104 | struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh) |
470decc6 DK |
2105 | { |
2106 | struct journal_head *jh = NULL; | |
2107 | ||
2108 | jbd_lock_bh_journal_head(bh); | |
2109 | if (buffer_jbd(bh)) { | |
2110 | jh = bh2jh(bh); | |
2111 | jh->b_jcount++; | |
2112 | } | |
2113 | jbd_unlock_bh_journal_head(bh); | |
2114 | return jh; | |
2115 | } | |
2116 | ||
2117 | static void __journal_remove_journal_head(struct buffer_head *bh) | |
2118 | { | |
2119 | struct journal_head *jh = bh2jh(bh); | |
2120 | ||
2121 | J_ASSERT_JH(jh, jh->b_jcount >= 0); | |
2122 | ||
2123 | get_bh(bh); | |
2124 | if (jh->b_jcount == 0) { | |
2125 | if (jh->b_transaction == NULL && | |
2126 | jh->b_next_transaction == NULL && | |
2127 | jh->b_cp_transaction == NULL) { | |
2128 | J_ASSERT_JH(jh, jh->b_jlist == BJ_None); | |
2129 | J_ASSERT_BH(bh, buffer_jbd(bh)); | |
2130 | J_ASSERT_BH(bh, jh2bh(jh) == bh); | |
2131 | BUFFER_TRACE(bh, "remove journal_head"); | |
2132 | if (jh->b_frozen_data) { | |
2133 | printk(KERN_WARNING "%s: freeing " | |
2134 | "b_frozen_data\n", | |
329d291f | 2135 | __func__); |
af1e76d6 | 2136 | jbd2_free(jh->b_frozen_data, bh->b_size); |
470decc6 DK |
2137 | } |
2138 | if (jh->b_committed_data) { | |
2139 | printk(KERN_WARNING "%s: freeing " | |
2140 | "b_committed_data\n", | |
329d291f | 2141 | __func__); |
af1e76d6 | 2142 | jbd2_free(jh->b_committed_data, bh->b_size); |
470decc6 DK |
2143 | } |
2144 | bh->b_private = NULL; | |
2145 | jh->b_bh = NULL; /* debug, really */ | |
2146 | clear_buffer_jbd(bh); | |
2147 | __brelse(bh); | |
2148 | journal_free_journal_head(jh); | |
2149 | } else { | |
2150 | BUFFER_TRACE(bh, "journal_head was locked"); | |
2151 | } | |
2152 | } | |
2153 | } | |
2154 | ||
2155 | /* | |
f7f4bccb | 2156 | * jbd2_journal_remove_journal_head(): if the buffer isn't attached to a transaction |
470decc6 DK |
2157 | * and has a zero b_jcount then remove and release its journal_head. If we did |
2158 | * see that the buffer is not used by any transaction we also "logically" | |
2159 | * decrement ->b_count. | |
2160 | * | |
2161 | * We in fact take an additional increment on ->b_count as a convenience, | |
2162 | * because the caller usually wants to do additional things with the bh | |
2163 | * after calling here. | |
f7f4bccb | 2164 | * The caller of jbd2_journal_remove_journal_head() *must* run __brelse(bh) at some |
470decc6 DK |
2165 | * time. Once the caller has run __brelse(), the buffer is eligible for |
2166 | * reaping by try_to_free_buffers(). | |
2167 | */ | |
f7f4bccb | 2168 | void jbd2_journal_remove_journal_head(struct buffer_head *bh) |
470decc6 DK |
2169 | { |
2170 | jbd_lock_bh_journal_head(bh); | |
2171 | __journal_remove_journal_head(bh); | |
2172 | jbd_unlock_bh_journal_head(bh); | |
2173 | } | |
2174 | ||
2175 | /* | |
2176 | * Drop a reference on the passed journal_head. If it fell to zero then try to | |
2177 | * release the journal_head from the buffer_head. | |
2178 | */ | |
f7f4bccb | 2179 | void jbd2_journal_put_journal_head(struct journal_head *jh) |
470decc6 DK |
2180 | { |
2181 | struct buffer_head *bh = jh2bh(jh); | |
2182 | ||
2183 | jbd_lock_bh_journal_head(bh); | |
2184 | J_ASSERT_JH(jh, jh->b_jcount > 0); | |
2185 | --jh->b_jcount; | |
2186 | if (!jh->b_jcount && !jh->b_transaction) { | |
2187 | __journal_remove_journal_head(bh); | |
2188 | __brelse(bh); | |
2189 | } | |
2190 | jbd_unlock_bh_journal_head(bh); | |
2191 | } | |
2192 | ||
c851ed54 JK |
2193 | /* |
2194 | * Initialize jbd inode head | |
2195 | */ | |
2196 | void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode) | |
2197 | { | |
2198 | jinode->i_transaction = NULL; | |
2199 | jinode->i_next_transaction = NULL; | |
2200 | jinode->i_vfs_inode = inode; | |
2201 | jinode->i_flags = 0; | |
2202 | INIT_LIST_HEAD(&jinode->i_list); | |
2203 | } | |
2204 | ||
2205 | /* | |
2206 | * Function to be called before we start removing inode from memory (i.e., | |
2207 | * clear_inode() is a fine place to be called from). It removes inode from | |
2208 | * transaction's lists. | |
2209 | */ | |
2210 | void jbd2_journal_release_jbd_inode(journal_t *journal, | |
2211 | struct jbd2_inode *jinode) | |
2212 | { | |
2213 | int writeout = 0; | |
2214 | ||
2215 | if (!journal) | |
2216 | return; | |
2217 | restart: | |
2218 | spin_lock(&journal->j_list_lock); | |
2219 | /* Is commit writing out inode - we have to wait */ | |
2220 | if (jinode->i_flags & JI_COMMIT_RUNNING) { | |
2221 | wait_queue_head_t *wq; | |
2222 | DEFINE_WAIT_BIT(wait, &jinode->i_flags, __JI_COMMIT_RUNNING); | |
2223 | wq = bit_waitqueue(&jinode->i_flags, __JI_COMMIT_RUNNING); | |
2224 | prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE); | |
2225 | spin_unlock(&journal->j_list_lock); | |
2226 | schedule(); | |
2227 | finish_wait(wq, &wait.wait); | |
2228 | goto restart; | |
2229 | } | |
2230 | ||
2231 | /* Do we need to wait for data writeback? */ | |
2232 | if (journal->j_committing_transaction == jinode->i_transaction) | |
2233 | writeout = 1; | |
2234 | if (jinode->i_transaction) { | |
2235 | list_del(&jinode->i_list); | |
2236 | jinode->i_transaction = NULL; | |
2237 | } | |
2238 | spin_unlock(&journal->j_list_lock); | |
2239 | } | |
2240 | ||
470decc6 | 2241 | /* |
0f49d5d0 | 2242 | * debugfs tunables |
470decc6 | 2243 | */ |
6f38c74f JS |
2244 | #ifdef CONFIG_JBD2_DEBUG |
2245 | u8 jbd2_journal_enable_debug __read_mostly; | |
f7f4bccb | 2246 | EXPORT_SYMBOL(jbd2_journal_enable_debug); |
470decc6 | 2247 | |
0f49d5d0 | 2248 | #define JBD2_DEBUG_NAME "jbd2-debug" |
470decc6 | 2249 | |
6f38c74f JS |
2250 | static struct dentry *jbd2_debugfs_dir; |
2251 | static struct dentry *jbd2_debug; | |
470decc6 | 2252 | |
0f49d5d0 JS |
2253 | static void __init jbd2_create_debugfs_entry(void) |
2254 | { | |
2255 | jbd2_debugfs_dir = debugfs_create_dir("jbd2", NULL); | |
2256 | if (jbd2_debugfs_dir) | |
2257 | jbd2_debug = debugfs_create_u8(JBD2_DEBUG_NAME, S_IRUGO, | |
2258 | jbd2_debugfs_dir, | |
2259 | &jbd2_journal_enable_debug); | |
470decc6 DK |
2260 | } |
2261 | ||
0f49d5d0 | 2262 | static void __exit jbd2_remove_debugfs_entry(void) |
470decc6 | 2263 | { |
6f38c74f JS |
2264 | debugfs_remove(jbd2_debug); |
2265 | debugfs_remove(jbd2_debugfs_dir); | |
470decc6 DK |
2266 | } |
2267 | ||
0f49d5d0 | 2268 | #else |
470decc6 | 2269 | |
0f49d5d0 | 2270 | static void __init jbd2_create_debugfs_entry(void) |
470decc6 | 2271 | { |
470decc6 DK |
2272 | } |
2273 | ||
0f49d5d0 | 2274 | static void __exit jbd2_remove_debugfs_entry(void) |
470decc6 | 2275 | { |
470decc6 DK |
2276 | } |
2277 | ||
470decc6 DK |
2278 | #endif |
2279 | ||
8e85fb3f JL |
2280 | #ifdef CONFIG_PROC_FS |
2281 | ||
2282 | #define JBD2_STATS_PROC_NAME "fs/jbd2" | |
2283 | ||
2284 | static void __init jbd2_create_jbd_stats_proc_entry(void) | |
2285 | { | |
2286 | proc_jbd2_stats = proc_mkdir(JBD2_STATS_PROC_NAME, NULL); | |
2287 | } | |
2288 | ||
2289 | static void __exit jbd2_remove_jbd_stats_proc_entry(void) | |
2290 | { | |
2291 | if (proc_jbd2_stats) | |
2292 | remove_proc_entry(JBD2_STATS_PROC_NAME, NULL); | |
2293 | } | |
2294 | ||
2295 | #else | |
2296 | ||
2297 | #define jbd2_create_jbd_stats_proc_entry() do {} while (0) | |
2298 | #define jbd2_remove_jbd_stats_proc_entry() do {} while (0) | |
2299 | ||
2300 | #endif | |
2301 | ||
e18b890b | 2302 | struct kmem_cache *jbd2_handle_cache; |
470decc6 DK |
2303 | |
2304 | static int __init journal_init_handle_cache(void) | |
2305 | { | |
a920e941 | 2306 | jbd2_handle_cache = kmem_cache_create("jbd2_journal_handle", |
470decc6 DK |
2307 | sizeof(handle_t), |
2308 | 0, /* offset */ | |
77160957 | 2309 | SLAB_TEMPORARY, /* flags */ |
20c2df83 | 2310 | NULL); /* ctor */ |
f7f4bccb | 2311 | if (jbd2_handle_cache == NULL) { |
470decc6 DK |
2312 | printk(KERN_EMERG "JBD: failed to create handle cache\n"); |
2313 | return -ENOMEM; | |
2314 | } | |
2315 | return 0; | |
2316 | } | |
2317 | ||
f7f4bccb | 2318 | static void jbd2_journal_destroy_handle_cache(void) |
470decc6 | 2319 | { |
f7f4bccb MC |
2320 | if (jbd2_handle_cache) |
2321 | kmem_cache_destroy(jbd2_handle_cache); | |
470decc6 DK |
2322 | } |
2323 | ||
2324 | /* | |
2325 | * Module startup and shutdown | |
2326 | */ | |
2327 | ||
2328 | static int __init journal_init_caches(void) | |
2329 | { | |
2330 | int ret; | |
2331 | ||
f7f4bccb | 2332 | ret = jbd2_journal_init_revoke_caches(); |
470decc6 | 2333 | if (ret == 0) |
f7f4bccb | 2334 | ret = journal_init_jbd2_journal_head_cache(); |
470decc6 DK |
2335 | if (ret == 0) |
2336 | ret = journal_init_handle_cache(); | |
2337 | return ret; | |
2338 | } | |
2339 | ||
f7f4bccb | 2340 | static void jbd2_journal_destroy_caches(void) |
470decc6 | 2341 | { |
f7f4bccb MC |
2342 | jbd2_journal_destroy_revoke_caches(); |
2343 | jbd2_journal_destroy_jbd2_journal_head_cache(); | |
2344 | jbd2_journal_destroy_handle_cache(); | |
470decc6 DK |
2345 | } |
2346 | ||
2347 | static int __init journal_init(void) | |
2348 | { | |
2349 | int ret; | |
2350 | ||
2351 | BUILD_BUG_ON(sizeof(struct journal_superblock_s) != 1024); | |
2352 | ||
2353 | ret = journal_init_caches(); | |
620de4e1 DG |
2354 | if (ret == 0) { |
2355 | jbd2_create_debugfs_entry(); | |
2356 | jbd2_create_jbd_stats_proc_entry(); | |
2357 | } else { | |
f7f4bccb | 2358 | jbd2_journal_destroy_caches(); |
620de4e1 | 2359 | } |
470decc6 DK |
2360 | return ret; |
2361 | } | |
2362 | ||
2363 | static void __exit journal_exit(void) | |
2364 | { | |
e23291b9 | 2365 | #ifdef CONFIG_JBD2_DEBUG |
470decc6 DK |
2366 | int n = atomic_read(&nr_journal_heads); |
2367 | if (n) | |
2368 | printk(KERN_EMERG "JBD: leaked %d journal_heads!\n", n); | |
2369 | #endif | |
0f49d5d0 | 2370 | jbd2_remove_debugfs_entry(); |
8e85fb3f | 2371 | jbd2_remove_jbd_stats_proc_entry(); |
f7f4bccb | 2372 | jbd2_journal_destroy_caches(); |
470decc6 DK |
2373 | } |
2374 | ||
2375 | MODULE_LICENSE("GPL"); | |
2376 | module_init(journal_init); | |
2377 | module_exit(journal_exit); | |
2378 |