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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> | |
43 | ||
f7f4bccb MC |
44 | EXPORT_SYMBOL(jbd2_journal_start); |
45 | EXPORT_SYMBOL(jbd2_journal_restart); | |
46 | EXPORT_SYMBOL(jbd2_journal_extend); | |
47 | EXPORT_SYMBOL(jbd2_journal_stop); | |
48 | EXPORT_SYMBOL(jbd2_journal_lock_updates); | |
49 | EXPORT_SYMBOL(jbd2_journal_unlock_updates); | |
50 | EXPORT_SYMBOL(jbd2_journal_get_write_access); | |
51 | EXPORT_SYMBOL(jbd2_journal_get_create_access); | |
52 | EXPORT_SYMBOL(jbd2_journal_get_undo_access); | |
53 | EXPORT_SYMBOL(jbd2_journal_dirty_data); | |
54 | EXPORT_SYMBOL(jbd2_journal_dirty_metadata); | |
55 | EXPORT_SYMBOL(jbd2_journal_release_buffer); | |
56 | EXPORT_SYMBOL(jbd2_journal_forget); | |
470decc6 DK |
57 | #if 0 |
58 | EXPORT_SYMBOL(journal_sync_buffer); | |
59 | #endif | |
f7f4bccb MC |
60 | EXPORT_SYMBOL(jbd2_journal_flush); |
61 | EXPORT_SYMBOL(jbd2_journal_revoke); | |
62 | ||
63 | EXPORT_SYMBOL(jbd2_journal_init_dev); | |
64 | EXPORT_SYMBOL(jbd2_journal_init_inode); | |
65 | EXPORT_SYMBOL(jbd2_journal_update_format); | |
66 | EXPORT_SYMBOL(jbd2_journal_check_used_features); | |
67 | EXPORT_SYMBOL(jbd2_journal_check_available_features); | |
68 | EXPORT_SYMBOL(jbd2_journal_set_features); | |
69 | EXPORT_SYMBOL(jbd2_journal_create); | |
70 | EXPORT_SYMBOL(jbd2_journal_load); | |
71 | EXPORT_SYMBOL(jbd2_journal_destroy); | |
72 | EXPORT_SYMBOL(jbd2_journal_update_superblock); | |
73 | EXPORT_SYMBOL(jbd2_journal_abort); | |
74 | EXPORT_SYMBOL(jbd2_journal_errno); | |
75 | EXPORT_SYMBOL(jbd2_journal_ack_err); | |
76 | EXPORT_SYMBOL(jbd2_journal_clear_err); | |
77 | EXPORT_SYMBOL(jbd2_log_wait_commit); | |
78 | EXPORT_SYMBOL(jbd2_journal_start_commit); | |
79 | EXPORT_SYMBOL(jbd2_journal_force_commit_nested); | |
80 | EXPORT_SYMBOL(jbd2_journal_wipe); | |
81 | EXPORT_SYMBOL(jbd2_journal_blocks_per_page); | |
82 | EXPORT_SYMBOL(jbd2_journal_invalidatepage); | |
83 | EXPORT_SYMBOL(jbd2_journal_try_to_free_buffers); | |
84 | EXPORT_SYMBOL(jbd2_journal_force_commit); | |
470decc6 DK |
85 | |
86 | static int journal_convert_superblock_v1(journal_t *, journal_superblock_t *); | |
87 | static void __journal_abort_soft (journal_t *journal, int errno); | |
470decc6 DK |
88 | |
89 | /* | |
90 | * Helper function used to manage commit timeouts | |
91 | */ | |
92 | ||
93 | static void commit_timeout(unsigned long __data) | |
94 | { | |
95 | struct task_struct * p = (struct task_struct *) __data; | |
96 | ||
97 | wake_up_process(p); | |
98 | } | |
99 | ||
100 | /* | |
f7f4bccb | 101 | * kjournald2: The main thread function used to manage a logging device |
470decc6 DK |
102 | * journal. |
103 | * | |
104 | * This kernel thread is responsible for two things: | |
105 | * | |
106 | * 1) COMMIT: Every so often we need to commit the current state of the | |
107 | * filesystem to disk. The journal thread is responsible for writing | |
108 | * all of the metadata buffers to disk. | |
109 | * | |
110 | * 2) CHECKPOINT: We cannot reuse a used section of the log file until all | |
111 | * of the data in that part of the log has been rewritten elsewhere on | |
112 | * the disk. Flushing these old buffers to reclaim space in the log is | |
113 | * known as checkpointing, and this thread is responsible for that job. | |
114 | */ | |
115 | ||
f7f4bccb | 116 | static int kjournald2(void *arg) |
470decc6 DK |
117 | { |
118 | journal_t *journal = arg; | |
119 | transaction_t *transaction; | |
120 | ||
121 | /* | |
122 | * Set up an interval timer which can be used to trigger a commit wakeup | |
123 | * after the commit interval expires | |
124 | */ | |
125 | setup_timer(&journal->j_commit_timer, commit_timeout, | |
126 | (unsigned long)current); | |
127 | ||
128 | /* Record that the journal thread is running */ | |
129 | journal->j_task = current; | |
130 | wake_up(&journal->j_wait_done_commit); | |
131 | ||
f7f4bccb | 132 | printk(KERN_INFO "kjournald2 starting. Commit interval %ld seconds\n", |
470decc6 DK |
133 | journal->j_commit_interval / HZ); |
134 | ||
135 | /* | |
136 | * And now, wait forever for commit wakeup events. | |
137 | */ | |
138 | spin_lock(&journal->j_state_lock); | |
139 | ||
140 | loop: | |
f7f4bccb | 141 | if (journal->j_flags & JBD2_UNMOUNT) |
470decc6 DK |
142 | goto end_loop; |
143 | ||
144 | jbd_debug(1, "commit_sequence=%d, commit_request=%d\n", | |
145 | journal->j_commit_sequence, journal->j_commit_request); | |
146 | ||
147 | if (journal->j_commit_sequence != journal->j_commit_request) { | |
148 | jbd_debug(1, "OK, requests differ\n"); | |
149 | spin_unlock(&journal->j_state_lock); | |
150 | del_timer_sync(&journal->j_commit_timer); | |
f7f4bccb | 151 | jbd2_journal_commit_transaction(journal); |
470decc6 DK |
152 | spin_lock(&journal->j_state_lock); |
153 | goto loop; | |
154 | } | |
155 | ||
156 | wake_up(&journal->j_wait_done_commit); | |
157 | if (freezing(current)) { | |
158 | /* | |
159 | * The simpler the better. Flushing journal isn't a | |
160 | * good idea, because that depends on threads that may | |
161 | * be already stopped. | |
162 | */ | |
f7f4bccb | 163 | jbd_debug(1, "Now suspending kjournald2\n"); |
470decc6 DK |
164 | spin_unlock(&journal->j_state_lock); |
165 | refrigerator(); | |
166 | spin_lock(&journal->j_state_lock); | |
167 | } else { | |
168 | /* | |
169 | * We assume on resume that commits are already there, | |
170 | * so we don't sleep | |
171 | */ | |
172 | DEFINE_WAIT(wait); | |
173 | int should_sleep = 1; | |
174 | ||
175 | prepare_to_wait(&journal->j_wait_commit, &wait, | |
176 | TASK_INTERRUPTIBLE); | |
177 | if (journal->j_commit_sequence != journal->j_commit_request) | |
178 | should_sleep = 0; | |
179 | transaction = journal->j_running_transaction; | |
180 | if (transaction && time_after_eq(jiffies, | |
181 | transaction->t_expires)) | |
182 | should_sleep = 0; | |
f7f4bccb | 183 | if (journal->j_flags & JBD2_UNMOUNT) |
470decc6 DK |
184 | should_sleep = 0; |
185 | if (should_sleep) { | |
186 | spin_unlock(&journal->j_state_lock); | |
187 | schedule(); | |
188 | spin_lock(&journal->j_state_lock); | |
189 | } | |
190 | finish_wait(&journal->j_wait_commit, &wait); | |
191 | } | |
192 | ||
f7f4bccb | 193 | jbd_debug(1, "kjournald2 wakes\n"); |
470decc6 DK |
194 | |
195 | /* | |
196 | * Were we woken up by a commit wakeup event? | |
197 | */ | |
198 | transaction = journal->j_running_transaction; | |
199 | if (transaction && time_after_eq(jiffies, transaction->t_expires)) { | |
200 | journal->j_commit_request = transaction->t_tid; | |
201 | jbd_debug(1, "woke because of timeout\n"); | |
202 | } | |
203 | goto loop; | |
204 | ||
205 | end_loop: | |
206 | spin_unlock(&journal->j_state_lock); | |
207 | del_timer_sync(&journal->j_commit_timer); | |
208 | journal->j_task = NULL; | |
209 | wake_up(&journal->j_wait_done_commit); | |
210 | jbd_debug(1, "Journal thread exiting.\n"); | |
211 | return 0; | |
212 | } | |
213 | ||
97f06784 | 214 | static int jbd2_journal_start_thread(journal_t *journal) |
470decc6 | 215 | { |
97f06784 PE |
216 | struct task_struct *t; |
217 | ||
218 | t = kthread_run(kjournald2, journal, "kjournald2"); | |
219 | if (IS_ERR(t)) | |
220 | return PTR_ERR(t); | |
221 | ||
470decc6 | 222 | wait_event(journal->j_wait_done_commit, journal->j_task != 0); |
97f06784 | 223 | return 0; |
470decc6 DK |
224 | } |
225 | ||
226 | static void journal_kill_thread(journal_t *journal) | |
227 | { | |
228 | spin_lock(&journal->j_state_lock); | |
f7f4bccb | 229 | journal->j_flags |= JBD2_UNMOUNT; |
470decc6 DK |
230 | |
231 | while (journal->j_task) { | |
232 | wake_up(&journal->j_wait_commit); | |
233 | spin_unlock(&journal->j_state_lock); | |
234 | wait_event(journal->j_wait_done_commit, journal->j_task == 0); | |
235 | spin_lock(&journal->j_state_lock); | |
236 | } | |
237 | spin_unlock(&journal->j_state_lock); | |
238 | } | |
239 | ||
240 | /* | |
f7f4bccb | 241 | * jbd2_journal_write_metadata_buffer: write a metadata buffer to the journal. |
470decc6 DK |
242 | * |
243 | * Writes a metadata buffer to a given disk block. The actual IO is not | |
244 | * performed but a new buffer_head is constructed which labels the data | |
245 | * to be written with the correct destination disk block. | |
246 | * | |
247 | * Any magic-number escaping which needs to be done will cause a | |
248 | * copy-out here. If the buffer happens to start with the | |
f7f4bccb | 249 | * JBD2_MAGIC_NUMBER, then we can't write it to the log directly: the |
470decc6 DK |
250 | * magic number is only written to the log for descripter blocks. In |
251 | * this case, we copy the data and replace the first word with 0, and we | |
252 | * return a result code which indicates that this buffer needs to be | |
253 | * marked as an escaped buffer in the corresponding log descriptor | |
254 | * block. The missing word can then be restored when the block is read | |
255 | * during recovery. | |
256 | * | |
257 | * If the source buffer has already been modified by a new transaction | |
258 | * since we took the last commit snapshot, we use the frozen copy of | |
259 | * that data for IO. If we end up using the existing buffer_head's data | |
260 | * for the write, then we *have* to lock the buffer to prevent anyone | |
261 | * else from using and possibly modifying it while the IO is in | |
262 | * progress. | |
263 | * | |
264 | * The function returns a pointer to the buffer_heads to be used for IO. | |
265 | * | |
266 | * We assume that the journal has already been locked in this function. | |
267 | * | |
268 | * Return value: | |
269 | * <0: Error | |
270 | * >=0: Finished OK | |
271 | * | |
272 | * On success: | |
273 | * Bit 0 set == escape performed on the data | |
274 | * Bit 1 set == buffer copy-out performed (kfree the data after IO) | |
275 | */ | |
276 | ||
f7f4bccb | 277 | int jbd2_journal_write_metadata_buffer(transaction_t *transaction, |
470decc6 DK |
278 | struct journal_head *jh_in, |
279 | struct journal_head **jh_out, | |
18eba7aa | 280 | unsigned long long blocknr) |
470decc6 DK |
281 | { |
282 | int need_copy_out = 0; | |
283 | int done_copy_out = 0; | |
284 | int do_escape = 0; | |
285 | char *mapped_data; | |
286 | struct buffer_head *new_bh; | |
287 | struct journal_head *new_jh; | |
288 | struct page *new_page; | |
289 | unsigned int new_offset; | |
290 | struct buffer_head *bh_in = jh2bh(jh_in); | |
291 | ||
292 | /* | |
293 | * The buffer really shouldn't be locked: only the current committing | |
294 | * transaction is allowed to write it, so nobody else is allowed | |
295 | * to do any IO. | |
296 | * | |
297 | * akpm: except if we're journalling data, and write() output is | |
298 | * also part of a shared mapping, and another thread has | |
299 | * decided to launch a writepage() against this buffer. | |
300 | */ | |
301 | J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in)); | |
302 | ||
303 | new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL); | |
304 | ||
305 | /* | |
306 | * If a new transaction has already done a buffer copy-out, then | |
307 | * we use that version of the data for the commit. | |
308 | */ | |
309 | jbd_lock_bh_state(bh_in); | |
310 | repeat: | |
311 | if (jh_in->b_frozen_data) { | |
312 | done_copy_out = 1; | |
313 | new_page = virt_to_page(jh_in->b_frozen_data); | |
314 | new_offset = offset_in_page(jh_in->b_frozen_data); | |
315 | } else { | |
316 | new_page = jh2bh(jh_in)->b_page; | |
317 | new_offset = offset_in_page(jh2bh(jh_in)->b_data); | |
318 | } | |
319 | ||
320 | mapped_data = kmap_atomic(new_page, KM_USER0); | |
321 | /* | |
322 | * Check for escaping | |
323 | */ | |
324 | if (*((__be32 *)(mapped_data + new_offset)) == | |
f7f4bccb | 325 | cpu_to_be32(JBD2_MAGIC_NUMBER)) { |
470decc6 DK |
326 | need_copy_out = 1; |
327 | do_escape = 1; | |
328 | } | |
329 | kunmap_atomic(mapped_data, KM_USER0); | |
330 | ||
331 | /* | |
332 | * Do we need to do a data copy? | |
333 | */ | |
334 | if (need_copy_out && !done_copy_out) { | |
335 | char *tmp; | |
336 | ||
337 | jbd_unlock_bh_state(bh_in); | |
af1e76d6 | 338 | tmp = jbd2_alloc(bh_in->b_size, GFP_NOFS); |
470decc6 DK |
339 | jbd_lock_bh_state(bh_in); |
340 | if (jh_in->b_frozen_data) { | |
af1e76d6 | 341 | jbd2_free(tmp, bh_in->b_size); |
470decc6 DK |
342 | goto repeat; |
343 | } | |
344 | ||
345 | jh_in->b_frozen_data = tmp; | |
346 | mapped_data = kmap_atomic(new_page, KM_USER0); | |
347 | memcpy(tmp, mapped_data + new_offset, jh2bh(jh_in)->b_size); | |
348 | kunmap_atomic(mapped_data, KM_USER0); | |
349 | ||
350 | new_page = virt_to_page(tmp); | |
351 | new_offset = offset_in_page(tmp); | |
352 | done_copy_out = 1; | |
353 | } | |
354 | ||
355 | /* | |
356 | * Did we need to do an escaping? Now we've done all the | |
357 | * copying, we can finally do so. | |
358 | */ | |
359 | if (do_escape) { | |
360 | mapped_data = kmap_atomic(new_page, KM_USER0); | |
361 | *((unsigned int *)(mapped_data + new_offset)) = 0; | |
362 | kunmap_atomic(mapped_data, KM_USER0); | |
363 | } | |
364 | ||
365 | /* keep subsequent assertions sane */ | |
366 | new_bh->b_state = 0; | |
367 | init_buffer(new_bh, NULL, NULL); | |
368 | atomic_set(&new_bh->b_count, 1); | |
369 | jbd_unlock_bh_state(bh_in); | |
370 | ||
f7f4bccb | 371 | new_jh = jbd2_journal_add_journal_head(new_bh); /* This sleeps */ |
470decc6 DK |
372 | |
373 | set_bh_page(new_bh, new_page, new_offset); | |
374 | new_jh->b_transaction = NULL; | |
375 | new_bh->b_size = jh2bh(jh_in)->b_size; | |
376 | new_bh->b_bdev = transaction->t_journal->j_dev; | |
377 | new_bh->b_blocknr = blocknr; | |
378 | set_buffer_mapped(new_bh); | |
379 | set_buffer_dirty(new_bh); | |
380 | ||
381 | *jh_out = new_jh; | |
382 | ||
383 | /* | |
384 | * The to-be-written buffer needs to get moved to the io queue, | |
385 | * and the original buffer whose contents we are shadowing or | |
386 | * copying is moved to the transaction's shadow queue. | |
387 | */ | |
388 | JBUFFER_TRACE(jh_in, "file as BJ_Shadow"); | |
f7f4bccb | 389 | jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow); |
470decc6 | 390 | JBUFFER_TRACE(new_jh, "file as BJ_IO"); |
f7f4bccb | 391 | jbd2_journal_file_buffer(new_jh, transaction, BJ_IO); |
470decc6 DK |
392 | |
393 | return do_escape | (done_copy_out << 1); | |
394 | } | |
395 | ||
396 | /* | |
397 | * Allocation code for the journal file. Manage the space left in the | |
398 | * journal, so that we can begin checkpointing when appropriate. | |
399 | */ | |
400 | ||
401 | /* | |
f7f4bccb | 402 | * __jbd2_log_space_left: Return the number of free blocks left in the journal. |
470decc6 DK |
403 | * |
404 | * Called with the journal already locked. | |
405 | * | |
406 | * Called under j_state_lock | |
407 | */ | |
408 | ||
f7f4bccb | 409 | int __jbd2_log_space_left(journal_t *journal) |
470decc6 DK |
410 | { |
411 | int left = journal->j_free; | |
412 | ||
413 | assert_spin_locked(&journal->j_state_lock); | |
414 | ||
415 | /* | |
416 | * Be pessimistic here about the number of those free blocks which | |
417 | * might be required for log descriptor control blocks. | |
418 | */ | |
419 | ||
420 | #define MIN_LOG_RESERVED_BLOCKS 32 /* Allow for rounding errors */ | |
421 | ||
422 | left -= MIN_LOG_RESERVED_BLOCKS; | |
423 | ||
424 | if (left <= 0) | |
425 | return 0; | |
426 | left -= (left >> 3); | |
427 | return left; | |
428 | } | |
429 | ||
430 | /* | |
431 | * Called under j_state_lock. Returns true if a transaction was started. | |
432 | */ | |
f7f4bccb | 433 | int __jbd2_log_start_commit(journal_t *journal, tid_t target) |
470decc6 DK |
434 | { |
435 | /* | |
436 | * Are we already doing a recent enough commit? | |
437 | */ | |
438 | if (!tid_geq(journal->j_commit_request, target)) { | |
439 | /* | |
440 | * We want a new commit: OK, mark the request and wakup the | |
441 | * commit thread. We do _not_ do the commit ourselves. | |
442 | */ | |
443 | ||
444 | journal->j_commit_request = target; | |
445 | jbd_debug(1, "JBD: requesting commit %d/%d\n", | |
446 | journal->j_commit_request, | |
447 | journal->j_commit_sequence); | |
448 | wake_up(&journal->j_wait_commit); | |
449 | return 1; | |
450 | } | |
451 | return 0; | |
452 | } | |
453 | ||
f7f4bccb | 454 | int jbd2_log_start_commit(journal_t *journal, tid_t tid) |
470decc6 DK |
455 | { |
456 | int ret; | |
457 | ||
458 | spin_lock(&journal->j_state_lock); | |
f7f4bccb | 459 | ret = __jbd2_log_start_commit(journal, tid); |
470decc6 DK |
460 | spin_unlock(&journal->j_state_lock); |
461 | return ret; | |
462 | } | |
463 | ||
464 | /* | |
465 | * Force and wait upon a commit if the calling process is not within | |
466 | * transaction. This is used for forcing out undo-protected data which contains | |
467 | * bitmaps, when the fs is running out of space. | |
468 | * | |
469 | * We can only force the running transaction if we don't have an active handle; | |
470 | * otherwise, we will deadlock. | |
471 | * | |
472 | * Returns true if a transaction was started. | |
473 | */ | |
f7f4bccb | 474 | int jbd2_journal_force_commit_nested(journal_t *journal) |
470decc6 DK |
475 | { |
476 | transaction_t *transaction = NULL; | |
477 | tid_t tid; | |
478 | ||
479 | spin_lock(&journal->j_state_lock); | |
480 | if (journal->j_running_transaction && !current->journal_info) { | |
481 | transaction = journal->j_running_transaction; | |
f7f4bccb | 482 | __jbd2_log_start_commit(journal, transaction->t_tid); |
470decc6 DK |
483 | } else if (journal->j_committing_transaction) |
484 | transaction = journal->j_committing_transaction; | |
485 | ||
486 | if (!transaction) { | |
487 | spin_unlock(&journal->j_state_lock); | |
488 | return 0; /* Nothing to retry */ | |
489 | } | |
490 | ||
491 | tid = transaction->t_tid; | |
492 | spin_unlock(&journal->j_state_lock); | |
f7f4bccb | 493 | jbd2_log_wait_commit(journal, tid); |
470decc6 DK |
494 | return 1; |
495 | } | |
496 | ||
497 | /* | |
498 | * Start a commit of the current running transaction (if any). Returns true | |
499 | * if a transaction was started, and fills its tid in at *ptid | |
500 | */ | |
f7f4bccb | 501 | int jbd2_journal_start_commit(journal_t *journal, tid_t *ptid) |
470decc6 DK |
502 | { |
503 | int ret = 0; | |
504 | ||
505 | spin_lock(&journal->j_state_lock); | |
506 | if (journal->j_running_transaction) { | |
507 | tid_t tid = journal->j_running_transaction->t_tid; | |
508 | ||
f7f4bccb | 509 | ret = __jbd2_log_start_commit(journal, tid); |
470decc6 DK |
510 | if (ret && ptid) |
511 | *ptid = tid; | |
512 | } else if (journal->j_committing_transaction && ptid) { | |
513 | /* | |
514 | * If ext3_write_super() recently started a commit, then we | |
515 | * have to wait for completion of that transaction | |
516 | */ | |
517 | *ptid = journal->j_committing_transaction->t_tid; | |
518 | ret = 1; | |
519 | } | |
520 | spin_unlock(&journal->j_state_lock); | |
521 | return ret; | |
522 | } | |
523 | ||
524 | /* | |
525 | * Wait for a specified commit to complete. | |
526 | * The caller may not hold the journal lock. | |
527 | */ | |
f7f4bccb | 528 | int jbd2_log_wait_commit(journal_t *journal, tid_t tid) |
470decc6 DK |
529 | { |
530 | int err = 0; | |
531 | ||
e23291b9 | 532 | #ifdef CONFIG_JBD2_DEBUG |
470decc6 DK |
533 | spin_lock(&journal->j_state_lock); |
534 | if (!tid_geq(journal->j_commit_request, tid)) { | |
535 | printk(KERN_EMERG | |
536 | "%s: error: j_commit_request=%d, tid=%d\n", | |
537 | __FUNCTION__, journal->j_commit_request, tid); | |
538 | } | |
539 | spin_unlock(&journal->j_state_lock); | |
540 | #endif | |
541 | spin_lock(&journal->j_state_lock); | |
542 | while (tid_gt(tid, journal->j_commit_sequence)) { | |
543 | jbd_debug(1, "JBD: want %d, j_commit_sequence=%d\n", | |
544 | tid, journal->j_commit_sequence); | |
545 | wake_up(&journal->j_wait_commit); | |
546 | spin_unlock(&journal->j_state_lock); | |
547 | wait_event(journal->j_wait_done_commit, | |
548 | !tid_gt(tid, journal->j_commit_sequence)); | |
549 | spin_lock(&journal->j_state_lock); | |
550 | } | |
551 | spin_unlock(&journal->j_state_lock); | |
552 | ||
553 | if (unlikely(is_journal_aborted(journal))) { | |
554 | printk(KERN_EMERG "journal commit I/O error\n"); | |
555 | err = -EIO; | |
556 | } | |
557 | return err; | |
558 | } | |
559 | ||
560 | /* | |
561 | * Log buffer allocation routines: | |
562 | */ | |
563 | ||
18eba7aa | 564 | int jbd2_journal_next_log_block(journal_t *journal, unsigned long long *retp) |
470decc6 DK |
565 | { |
566 | unsigned long blocknr; | |
567 | ||
568 | spin_lock(&journal->j_state_lock); | |
569 | J_ASSERT(journal->j_free > 1); | |
570 | ||
571 | blocknr = journal->j_head; | |
572 | journal->j_head++; | |
573 | journal->j_free--; | |
574 | if (journal->j_head == journal->j_last) | |
575 | journal->j_head = journal->j_first; | |
576 | spin_unlock(&journal->j_state_lock); | |
f7f4bccb | 577 | return jbd2_journal_bmap(journal, blocknr, retp); |
470decc6 DK |
578 | } |
579 | ||
580 | /* | |
581 | * Conversion of logical to physical block numbers for the journal | |
582 | * | |
583 | * On external journals the journal blocks are identity-mapped, so | |
584 | * this is a no-op. If needed, we can use j_blk_offset - everything is | |
585 | * ready. | |
586 | */ | |
f7f4bccb | 587 | int jbd2_journal_bmap(journal_t *journal, unsigned long blocknr, |
18eba7aa | 588 | unsigned long long *retp) |
470decc6 DK |
589 | { |
590 | int err = 0; | |
18eba7aa | 591 | unsigned long long ret; |
470decc6 DK |
592 | |
593 | if (journal->j_inode) { | |
594 | ret = bmap(journal->j_inode, blocknr); | |
595 | if (ret) | |
596 | *retp = ret; | |
597 | else { | |
598 | char b[BDEVNAME_SIZE]; | |
599 | ||
600 | printk(KERN_ALERT "%s: journal block not found " | |
601 | "at offset %lu on %s\n", | |
602 | __FUNCTION__, | |
603 | blocknr, | |
604 | bdevname(journal->j_dev, b)); | |
605 | err = -EIO; | |
606 | __journal_abort_soft(journal, err); | |
607 | } | |
608 | } else { | |
609 | *retp = blocknr; /* +journal->j_blk_offset */ | |
610 | } | |
611 | return err; | |
612 | } | |
613 | ||
614 | /* | |
615 | * We play buffer_head aliasing tricks to write data/metadata blocks to | |
616 | * the journal without copying their contents, but for journal | |
617 | * descriptor blocks we do need to generate bona fide buffers. | |
618 | * | |
f7f4bccb | 619 | * After the caller of jbd2_journal_get_descriptor_buffer() has finished modifying |
470decc6 DK |
620 | * the buffer's contents they really should run flush_dcache_page(bh->b_page). |
621 | * But we don't bother doing that, so there will be coherency problems with | |
622 | * mmaps of blockdevs which hold live JBD-controlled filesystems. | |
623 | */ | |
f7f4bccb | 624 | struct journal_head *jbd2_journal_get_descriptor_buffer(journal_t *journal) |
470decc6 DK |
625 | { |
626 | struct buffer_head *bh; | |
18eba7aa | 627 | unsigned long long blocknr; |
470decc6 DK |
628 | int err; |
629 | ||
f7f4bccb | 630 | err = jbd2_journal_next_log_block(journal, &blocknr); |
470decc6 DK |
631 | |
632 | if (err) | |
633 | return NULL; | |
634 | ||
635 | bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); | |
636 | lock_buffer(bh); | |
637 | memset(bh->b_data, 0, journal->j_blocksize); | |
638 | set_buffer_uptodate(bh); | |
639 | unlock_buffer(bh); | |
640 | BUFFER_TRACE(bh, "return this buffer"); | |
f7f4bccb | 641 | return jbd2_journal_add_journal_head(bh); |
470decc6 DK |
642 | } |
643 | ||
8e85fb3f JL |
644 | struct jbd2_stats_proc_session { |
645 | journal_t *journal; | |
646 | struct transaction_stats_s *stats; | |
647 | int start; | |
648 | int max; | |
649 | }; | |
650 | ||
651 | static void *jbd2_history_skip_empty(struct jbd2_stats_proc_session *s, | |
652 | struct transaction_stats_s *ts, | |
653 | int first) | |
654 | { | |
655 | if (ts == s->stats + s->max) | |
656 | ts = s->stats; | |
657 | if (!first && ts == s->stats + s->start) | |
658 | return NULL; | |
659 | while (ts->ts_type == 0) { | |
660 | ts++; | |
661 | if (ts == s->stats + s->max) | |
662 | ts = s->stats; | |
663 | if (ts == s->stats + s->start) | |
664 | return NULL; | |
665 | } | |
666 | return ts; | |
667 | ||
668 | } | |
669 | ||
670 | static void *jbd2_seq_history_start(struct seq_file *seq, loff_t *pos) | |
671 | { | |
672 | struct jbd2_stats_proc_session *s = seq->private; | |
673 | struct transaction_stats_s *ts; | |
674 | int l = *pos; | |
675 | ||
676 | if (l == 0) | |
677 | return SEQ_START_TOKEN; | |
678 | ts = jbd2_history_skip_empty(s, s->stats + s->start, 1); | |
679 | if (!ts) | |
680 | return NULL; | |
681 | l--; | |
682 | while (l) { | |
683 | ts = jbd2_history_skip_empty(s, ++ts, 0); | |
684 | if (!ts) | |
685 | break; | |
686 | l--; | |
687 | } | |
688 | return ts; | |
689 | } | |
690 | ||
691 | static void *jbd2_seq_history_next(struct seq_file *seq, void *v, loff_t *pos) | |
692 | { | |
693 | struct jbd2_stats_proc_session *s = seq->private; | |
694 | struct transaction_stats_s *ts = v; | |
695 | ||
696 | ++*pos; | |
697 | if (v == SEQ_START_TOKEN) | |
698 | return jbd2_history_skip_empty(s, s->stats + s->start, 1); | |
699 | else | |
700 | return jbd2_history_skip_empty(s, ++ts, 0); | |
701 | } | |
702 | ||
703 | static int jbd2_seq_history_show(struct seq_file *seq, void *v) | |
704 | { | |
705 | struct transaction_stats_s *ts = v; | |
706 | if (v == SEQ_START_TOKEN) { | |
707 | seq_printf(seq, "%-4s %-5s %-5s %-5s %-5s %-5s %-5s %-6s %-5s " | |
708 | "%-5s %-5s %-5s %-5s %-5s\n", "R/C", "tid", | |
709 | "wait", "run", "lock", "flush", "log", "hndls", | |
710 | "block", "inlog", "ctime", "write", "drop", | |
711 | "close"); | |
712 | return 0; | |
713 | } | |
714 | if (ts->ts_type == JBD2_STATS_RUN) | |
715 | seq_printf(seq, "%-4s %-5lu %-5u %-5u %-5u %-5u %-5u " | |
716 | "%-6lu %-5lu %-5lu\n", "R", ts->ts_tid, | |
717 | jiffies_to_msecs(ts->u.run.rs_wait), | |
718 | jiffies_to_msecs(ts->u.run.rs_running), | |
719 | jiffies_to_msecs(ts->u.run.rs_locked), | |
720 | jiffies_to_msecs(ts->u.run.rs_flushing), | |
721 | jiffies_to_msecs(ts->u.run.rs_logging), | |
722 | ts->u.run.rs_handle_count, | |
723 | ts->u.run.rs_blocks, | |
724 | ts->u.run.rs_blocks_logged); | |
725 | else if (ts->ts_type == JBD2_STATS_CHECKPOINT) | |
726 | seq_printf(seq, "%-4s %-5lu %48s %-5u %-5lu %-5lu %-5lu\n", | |
727 | "C", ts->ts_tid, " ", | |
728 | jiffies_to_msecs(ts->u.chp.cs_chp_time), | |
729 | ts->u.chp.cs_written, ts->u.chp.cs_dropped, | |
730 | ts->u.chp.cs_forced_to_close); | |
731 | else | |
732 | J_ASSERT(0); | |
733 | return 0; | |
734 | } | |
735 | ||
736 | static void jbd2_seq_history_stop(struct seq_file *seq, void *v) | |
737 | { | |
738 | } | |
739 | ||
740 | static struct seq_operations jbd2_seq_history_ops = { | |
741 | .start = jbd2_seq_history_start, | |
742 | .next = jbd2_seq_history_next, | |
743 | .stop = jbd2_seq_history_stop, | |
744 | .show = jbd2_seq_history_show, | |
745 | }; | |
746 | ||
747 | static int jbd2_seq_history_open(struct inode *inode, struct file *file) | |
748 | { | |
749 | journal_t *journal = PDE(inode)->data; | |
750 | struct jbd2_stats_proc_session *s; | |
751 | int rc, size; | |
752 | ||
753 | s = kmalloc(sizeof(*s), GFP_KERNEL); | |
754 | if (s == NULL) | |
755 | return -ENOMEM; | |
756 | size = sizeof(struct transaction_stats_s) * journal->j_history_max; | |
757 | s->stats = kmalloc(size, GFP_KERNEL); | |
758 | if (s->stats == NULL) { | |
759 | kfree(s); | |
760 | return -ENOMEM; | |
761 | } | |
762 | spin_lock(&journal->j_history_lock); | |
763 | memcpy(s->stats, journal->j_history, size); | |
764 | s->max = journal->j_history_max; | |
765 | s->start = journal->j_history_cur % s->max; | |
766 | spin_unlock(&journal->j_history_lock); | |
767 | ||
768 | rc = seq_open(file, &jbd2_seq_history_ops); | |
769 | if (rc == 0) { | |
770 | struct seq_file *m = file->private_data; | |
771 | m->private = s; | |
772 | } else { | |
773 | kfree(s->stats); | |
774 | kfree(s); | |
775 | } | |
776 | return rc; | |
777 | ||
778 | } | |
779 | ||
780 | static int jbd2_seq_history_release(struct inode *inode, struct file *file) | |
781 | { | |
782 | struct seq_file *seq = file->private_data; | |
783 | struct jbd2_stats_proc_session *s = seq->private; | |
784 | ||
785 | kfree(s->stats); | |
786 | kfree(s); | |
787 | return seq_release(inode, file); | |
788 | } | |
789 | ||
790 | static struct file_operations jbd2_seq_history_fops = { | |
791 | .owner = THIS_MODULE, | |
792 | .open = jbd2_seq_history_open, | |
793 | .read = seq_read, | |
794 | .llseek = seq_lseek, | |
795 | .release = jbd2_seq_history_release, | |
796 | }; | |
797 | ||
798 | static void *jbd2_seq_info_start(struct seq_file *seq, loff_t *pos) | |
799 | { | |
800 | return *pos ? NULL : SEQ_START_TOKEN; | |
801 | } | |
802 | ||
803 | static void *jbd2_seq_info_next(struct seq_file *seq, void *v, loff_t *pos) | |
804 | { | |
805 | return NULL; | |
806 | } | |
807 | ||
808 | static int jbd2_seq_info_show(struct seq_file *seq, void *v) | |
809 | { | |
810 | struct jbd2_stats_proc_session *s = seq->private; | |
811 | ||
812 | if (v != SEQ_START_TOKEN) | |
813 | return 0; | |
814 | seq_printf(seq, "%lu transaction, each upto %u blocks\n", | |
815 | s->stats->ts_tid, | |
816 | s->journal->j_max_transaction_buffers); | |
817 | if (s->stats->ts_tid == 0) | |
818 | return 0; | |
819 | seq_printf(seq, "average: \n %ums waiting for transaction\n", | |
820 | jiffies_to_msecs(s->stats->u.run.rs_wait / s->stats->ts_tid)); | |
821 | seq_printf(seq, " %ums running transaction\n", | |
822 | jiffies_to_msecs(s->stats->u.run.rs_running / s->stats->ts_tid)); | |
823 | seq_printf(seq, " %ums transaction was being locked\n", | |
824 | jiffies_to_msecs(s->stats->u.run.rs_locked / s->stats->ts_tid)); | |
825 | seq_printf(seq, " %ums flushing data (in ordered mode)\n", | |
826 | jiffies_to_msecs(s->stats->u.run.rs_flushing / s->stats->ts_tid)); | |
827 | seq_printf(seq, " %ums logging transaction\n", | |
828 | jiffies_to_msecs(s->stats->u.run.rs_logging / s->stats->ts_tid)); | |
829 | seq_printf(seq, " %lu handles per transaction\n", | |
830 | s->stats->u.run.rs_handle_count / s->stats->ts_tid); | |
831 | seq_printf(seq, " %lu blocks per transaction\n", | |
832 | s->stats->u.run.rs_blocks / s->stats->ts_tid); | |
833 | seq_printf(seq, " %lu logged blocks per transaction\n", | |
834 | s->stats->u.run.rs_blocks_logged / s->stats->ts_tid); | |
835 | return 0; | |
836 | } | |
837 | ||
838 | static void jbd2_seq_info_stop(struct seq_file *seq, void *v) | |
839 | { | |
840 | } | |
841 | ||
842 | static struct seq_operations jbd2_seq_info_ops = { | |
843 | .start = jbd2_seq_info_start, | |
844 | .next = jbd2_seq_info_next, | |
845 | .stop = jbd2_seq_info_stop, | |
846 | .show = jbd2_seq_info_show, | |
847 | }; | |
848 | ||
849 | static int jbd2_seq_info_open(struct inode *inode, struct file *file) | |
850 | { | |
851 | journal_t *journal = PDE(inode)->data; | |
852 | struct jbd2_stats_proc_session *s; | |
853 | int rc, size; | |
854 | ||
855 | s = kmalloc(sizeof(*s), GFP_KERNEL); | |
856 | if (s == NULL) | |
857 | return -ENOMEM; | |
858 | size = sizeof(struct transaction_stats_s); | |
859 | s->stats = kmalloc(size, GFP_KERNEL); | |
860 | if (s->stats == NULL) { | |
861 | kfree(s); | |
862 | return -ENOMEM; | |
863 | } | |
864 | spin_lock(&journal->j_history_lock); | |
865 | memcpy(s->stats, &journal->j_stats, size); | |
866 | s->journal = journal; | |
867 | spin_unlock(&journal->j_history_lock); | |
868 | ||
869 | rc = seq_open(file, &jbd2_seq_info_ops); | |
870 | if (rc == 0) { | |
871 | struct seq_file *m = file->private_data; | |
872 | m->private = s; | |
873 | } else { | |
874 | kfree(s->stats); | |
875 | kfree(s); | |
876 | } | |
877 | return rc; | |
878 | ||
879 | } | |
880 | ||
881 | static int jbd2_seq_info_release(struct inode *inode, struct file *file) | |
882 | { | |
883 | struct seq_file *seq = file->private_data; | |
884 | struct jbd2_stats_proc_session *s = seq->private; | |
885 | kfree(s->stats); | |
886 | kfree(s); | |
887 | return seq_release(inode, file); | |
888 | } | |
889 | ||
890 | static struct file_operations jbd2_seq_info_fops = { | |
891 | .owner = THIS_MODULE, | |
892 | .open = jbd2_seq_info_open, | |
893 | .read = seq_read, | |
894 | .llseek = seq_lseek, | |
895 | .release = jbd2_seq_info_release, | |
896 | }; | |
897 | ||
898 | static struct proc_dir_entry *proc_jbd2_stats; | |
899 | ||
900 | static void jbd2_stats_proc_init(journal_t *journal) | |
901 | { | |
902 | char name[BDEVNAME_SIZE]; | |
903 | ||
904 | snprintf(name, sizeof(name) - 1, "%s", bdevname(journal->j_dev, name)); | |
905 | journal->j_proc_entry = proc_mkdir(name, proc_jbd2_stats); | |
906 | if (journal->j_proc_entry) { | |
907 | struct proc_dir_entry *p; | |
908 | p = create_proc_entry("history", S_IRUGO, | |
909 | journal->j_proc_entry); | |
910 | if (p) { | |
911 | p->proc_fops = &jbd2_seq_history_fops; | |
912 | p->data = journal; | |
913 | p = create_proc_entry("info", S_IRUGO, | |
914 | journal->j_proc_entry); | |
915 | if (p) { | |
916 | p->proc_fops = &jbd2_seq_info_fops; | |
917 | p->data = journal; | |
918 | } | |
919 | } | |
920 | } | |
921 | } | |
922 | ||
923 | static void jbd2_stats_proc_exit(journal_t *journal) | |
924 | { | |
925 | char name[BDEVNAME_SIZE]; | |
926 | ||
927 | snprintf(name, sizeof(name) - 1, "%s", bdevname(journal->j_dev, name)); | |
928 | remove_proc_entry("info", journal->j_proc_entry); | |
929 | remove_proc_entry("history", journal->j_proc_entry); | |
930 | remove_proc_entry(name, proc_jbd2_stats); | |
931 | } | |
932 | ||
933 | static void journal_init_stats(journal_t *journal) | |
934 | { | |
935 | int size; | |
936 | ||
937 | if (!proc_jbd2_stats) | |
938 | return; | |
939 | ||
940 | journal->j_history_max = 100; | |
941 | size = sizeof(struct transaction_stats_s) * journal->j_history_max; | |
942 | journal->j_history = kzalloc(size, GFP_KERNEL); | |
943 | if (!journal->j_history) { | |
944 | journal->j_history_max = 0; | |
945 | return; | |
946 | } | |
947 | spin_lock_init(&journal->j_history_lock); | |
948 | } | |
949 | ||
470decc6 DK |
950 | /* |
951 | * Management for journal control blocks: functions to create and | |
952 | * destroy journal_t structures, and to initialise and read existing | |
953 | * journal blocks from disk. */ | |
954 | ||
955 | /* First: create and setup a journal_t object in memory. We initialise | |
956 | * very few fields yet: that has to wait until we have created the | |
957 | * journal structures from from scratch, or loaded them from disk. */ | |
958 | ||
959 | static journal_t * journal_init_common (void) | |
960 | { | |
961 | journal_t *journal; | |
962 | int err; | |
963 | ||
d802ffa8 | 964 | journal = kzalloc(sizeof(*journal), GFP_KERNEL|__GFP_NOFAIL); |
470decc6 DK |
965 | if (!journal) |
966 | goto fail; | |
470decc6 DK |
967 | |
968 | init_waitqueue_head(&journal->j_wait_transaction_locked); | |
969 | init_waitqueue_head(&journal->j_wait_logspace); | |
970 | init_waitqueue_head(&journal->j_wait_done_commit); | |
971 | init_waitqueue_head(&journal->j_wait_checkpoint); | |
972 | init_waitqueue_head(&journal->j_wait_commit); | |
973 | init_waitqueue_head(&journal->j_wait_updates); | |
974 | mutex_init(&journal->j_barrier); | |
975 | mutex_init(&journal->j_checkpoint_mutex); | |
976 | spin_lock_init(&journal->j_revoke_lock); | |
977 | spin_lock_init(&journal->j_list_lock); | |
978 | spin_lock_init(&journal->j_state_lock); | |
979 | ||
cd02ff0b | 980 | journal->j_commit_interval = (HZ * JBD2_DEFAULT_MAX_COMMIT_AGE); |
470decc6 DK |
981 | |
982 | /* The journal is marked for error until we succeed with recovery! */ | |
f7f4bccb | 983 | journal->j_flags = JBD2_ABORT; |
470decc6 DK |
984 | |
985 | /* Set up a default-sized revoke table for the new mount. */ | |
f7f4bccb | 986 | err = jbd2_journal_init_revoke(journal, JOURNAL_REVOKE_DEFAULT_HASH); |
470decc6 DK |
987 | if (err) { |
988 | kfree(journal); | |
989 | goto fail; | |
990 | } | |
8e85fb3f JL |
991 | |
992 | journal_init_stats(journal); | |
993 | ||
470decc6 DK |
994 | return journal; |
995 | fail: | |
996 | return NULL; | |
997 | } | |
998 | ||
f7f4bccb | 999 | /* jbd2_journal_init_dev and jbd2_journal_init_inode: |
470decc6 DK |
1000 | * |
1001 | * Create a journal structure assigned some fixed set of disk blocks to | |
1002 | * the journal. We don't actually touch those disk blocks yet, but we | |
1003 | * need to set up all of the mapping information to tell the journaling | |
1004 | * system where the journal blocks are. | |
1005 | * | |
1006 | */ | |
1007 | ||
1008 | /** | |
f7f4bccb | 1009 | * journal_t * jbd2_journal_init_dev() - creates an initialises a journal structure |
470decc6 DK |
1010 | * @bdev: Block device on which to create the journal |
1011 | * @fs_dev: Device which hold journalled filesystem for this journal. | |
1012 | * @start: Block nr Start of journal. | |
1013 | * @len: Length of the journal in blocks. | |
1014 | * @blocksize: blocksize of journalling device | |
1015 | * @returns: a newly created journal_t * | |
1016 | * | |
f7f4bccb | 1017 | * jbd2_journal_init_dev creates a journal which maps a fixed contiguous |
470decc6 DK |
1018 | * range of blocks on an arbitrary block device. |
1019 | * | |
1020 | */ | |
f7f4bccb | 1021 | journal_t * jbd2_journal_init_dev(struct block_device *bdev, |
470decc6 | 1022 | struct block_device *fs_dev, |
18eba7aa | 1023 | unsigned long long start, int len, int blocksize) |
470decc6 DK |
1024 | { |
1025 | journal_t *journal = journal_init_common(); | |
1026 | struct buffer_head *bh; | |
1027 | int n; | |
1028 | ||
1029 | if (!journal) | |
1030 | return NULL; | |
1031 | ||
1032 | /* journal descriptor can store up to n blocks -bzzz */ | |
1033 | journal->j_blocksize = blocksize; | |
1034 | n = journal->j_blocksize / sizeof(journal_block_tag_t); | |
1035 | journal->j_wbufsize = n; | |
1036 | journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL); | |
1037 | if (!journal->j_wbuf) { | |
1038 | printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n", | |
1039 | __FUNCTION__); | |
1040 | kfree(journal); | |
1041 | journal = NULL; | |
5eb30790 | 1042 | goto out; |
470decc6 DK |
1043 | } |
1044 | journal->j_dev = bdev; | |
1045 | journal->j_fs_dev = fs_dev; | |
1046 | journal->j_blk_offset = start; | |
1047 | journal->j_maxlen = len; | |
8e85fb3f | 1048 | jbd2_stats_proc_init(journal); |
470decc6 DK |
1049 | |
1050 | bh = __getblk(journal->j_dev, start, journal->j_blocksize); | |
1051 | J_ASSERT(bh != NULL); | |
1052 | journal->j_sb_buffer = bh; | |
1053 | journal->j_superblock = (journal_superblock_t *)bh->b_data; | |
5eb30790 | 1054 | out: |
470decc6 DK |
1055 | return journal; |
1056 | } | |
1057 | ||
1058 | /** | |
f7f4bccb | 1059 | * journal_t * jbd2_journal_init_inode () - creates a journal which maps to a inode. |
470decc6 DK |
1060 | * @inode: An inode to create the journal in |
1061 | * | |
f7f4bccb | 1062 | * jbd2_journal_init_inode creates a journal which maps an on-disk inode as |
470decc6 DK |
1063 | * the journal. The inode must exist already, must support bmap() and |
1064 | * must have all data blocks preallocated. | |
1065 | */ | |
f7f4bccb | 1066 | journal_t * jbd2_journal_init_inode (struct inode *inode) |
470decc6 DK |
1067 | { |
1068 | struct buffer_head *bh; | |
1069 | journal_t *journal = journal_init_common(); | |
1070 | int err; | |
1071 | int n; | |
18eba7aa | 1072 | unsigned long long blocknr; |
470decc6 DK |
1073 | |
1074 | if (!journal) | |
1075 | return NULL; | |
1076 | ||
1077 | journal->j_dev = journal->j_fs_dev = inode->i_sb->s_bdev; | |
1078 | journal->j_inode = inode; | |
1079 | jbd_debug(1, | |
1080 | "journal %p: inode %s/%ld, size %Ld, bits %d, blksize %ld\n", | |
1081 | journal, inode->i_sb->s_id, inode->i_ino, | |
1082 | (long long) inode->i_size, | |
1083 | inode->i_sb->s_blocksize_bits, inode->i_sb->s_blocksize); | |
1084 | ||
1085 | journal->j_maxlen = inode->i_size >> inode->i_sb->s_blocksize_bits; | |
1086 | journal->j_blocksize = inode->i_sb->s_blocksize; | |
8e85fb3f | 1087 | jbd2_stats_proc_init(journal); |
470decc6 DK |
1088 | |
1089 | /* journal descriptor can store up to n blocks -bzzz */ | |
1090 | n = journal->j_blocksize / sizeof(journal_block_tag_t); | |
1091 | journal->j_wbufsize = n; | |
1092 | journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL); | |
1093 | if (!journal->j_wbuf) { | |
1094 | printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n", | |
1095 | __FUNCTION__); | |
1096 | kfree(journal); | |
1097 | return NULL; | |
1098 | } | |
1099 | ||
f7f4bccb | 1100 | err = jbd2_journal_bmap(journal, 0, &blocknr); |
470decc6 DK |
1101 | /* If that failed, give up */ |
1102 | if (err) { | |
1103 | printk(KERN_ERR "%s: Cannnot locate journal superblock\n", | |
1104 | __FUNCTION__); | |
1105 | kfree(journal); | |
1106 | return NULL; | |
1107 | } | |
1108 | ||
1109 | bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); | |
1110 | J_ASSERT(bh != NULL); | |
1111 | journal->j_sb_buffer = bh; | |
1112 | journal->j_superblock = (journal_superblock_t *)bh->b_data; | |
1113 | ||
1114 | return journal; | |
1115 | } | |
1116 | ||
1117 | /* | |
1118 | * If the journal init or create aborts, we need to mark the journal | |
1119 | * superblock as being NULL to prevent the journal destroy from writing | |
1120 | * back a bogus superblock. | |
1121 | */ | |
1122 | static void journal_fail_superblock (journal_t *journal) | |
1123 | { | |
1124 | struct buffer_head *bh = journal->j_sb_buffer; | |
1125 | brelse(bh); | |
1126 | journal->j_sb_buffer = NULL; | |
1127 | } | |
1128 | ||
1129 | /* | |
1130 | * Given a journal_t structure, initialise the various fields for | |
1131 | * startup of a new journaling session. We use this both when creating | |
1132 | * a journal, and after recovering an old journal to reset it for | |
1133 | * subsequent use. | |
1134 | */ | |
1135 | ||
1136 | static int journal_reset(journal_t *journal) | |
1137 | { | |
1138 | journal_superblock_t *sb = journal->j_superblock; | |
18eba7aa | 1139 | unsigned long long first, last; |
470decc6 DK |
1140 | |
1141 | first = be32_to_cpu(sb->s_first); | |
1142 | last = be32_to_cpu(sb->s_maxlen); | |
1143 | ||
1144 | journal->j_first = first; | |
1145 | journal->j_last = last; | |
1146 | ||
1147 | journal->j_head = first; | |
1148 | journal->j_tail = first; | |
1149 | journal->j_free = last - first; | |
1150 | ||
1151 | journal->j_tail_sequence = journal->j_transaction_sequence; | |
1152 | journal->j_commit_sequence = journal->j_transaction_sequence - 1; | |
1153 | journal->j_commit_request = journal->j_commit_sequence; | |
1154 | ||
1155 | journal->j_max_transaction_buffers = journal->j_maxlen / 4; | |
1156 | ||
1157 | /* Add the dynamic fields and write it to disk. */ | |
f7f4bccb | 1158 | jbd2_journal_update_superblock(journal, 1); |
97f06784 | 1159 | return jbd2_journal_start_thread(journal); |
470decc6 DK |
1160 | } |
1161 | ||
1162 | /** | |
f7f4bccb | 1163 | * int jbd2_journal_create() - Initialise the new journal file |
470decc6 DK |
1164 | * @journal: Journal to create. This structure must have been initialised |
1165 | * | |
1166 | * Given a journal_t structure which tells us which disk blocks we can | |
1167 | * use, create a new journal superblock and initialise all of the | |
1168 | * journal fields from scratch. | |
1169 | **/ | |
f7f4bccb | 1170 | int jbd2_journal_create(journal_t *journal) |
470decc6 | 1171 | { |
18eba7aa | 1172 | unsigned long long blocknr; |
470decc6 DK |
1173 | struct buffer_head *bh; |
1174 | journal_superblock_t *sb; | |
1175 | int i, err; | |
1176 | ||
f7f4bccb | 1177 | if (journal->j_maxlen < JBD2_MIN_JOURNAL_BLOCKS) { |
470decc6 DK |
1178 | printk (KERN_ERR "Journal length (%d blocks) too short.\n", |
1179 | journal->j_maxlen); | |
1180 | journal_fail_superblock(journal); | |
1181 | return -EINVAL; | |
1182 | } | |
1183 | ||
1184 | if (journal->j_inode == NULL) { | |
1185 | /* | |
1186 | * We don't know what block to start at! | |
1187 | */ | |
1188 | printk(KERN_EMERG | |
1189 | "%s: creation of journal on external device!\n", | |
1190 | __FUNCTION__); | |
1191 | BUG(); | |
1192 | } | |
1193 | ||
1194 | /* Zero out the entire journal on disk. We cannot afford to | |
f7f4bccb | 1195 | have any blocks on disk beginning with JBD2_MAGIC_NUMBER. */ |
470decc6 DK |
1196 | jbd_debug(1, "JBD: Zeroing out journal blocks...\n"); |
1197 | for (i = 0; i < journal->j_maxlen; i++) { | |
f7f4bccb | 1198 | err = jbd2_journal_bmap(journal, i, &blocknr); |
470decc6 DK |
1199 | if (err) |
1200 | return err; | |
1201 | bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); | |
1202 | lock_buffer(bh); | |
1203 | memset (bh->b_data, 0, journal->j_blocksize); | |
1204 | BUFFER_TRACE(bh, "marking dirty"); | |
1205 | mark_buffer_dirty(bh); | |
1206 | BUFFER_TRACE(bh, "marking uptodate"); | |
1207 | set_buffer_uptodate(bh); | |
1208 | unlock_buffer(bh); | |
1209 | __brelse(bh); | |
1210 | } | |
1211 | ||
1212 | sync_blockdev(journal->j_dev); | |
1213 | jbd_debug(1, "JBD: journal cleared.\n"); | |
1214 | ||
1215 | /* OK, fill in the initial static fields in the new superblock */ | |
1216 | sb = journal->j_superblock; | |
1217 | ||
f7f4bccb MC |
1218 | sb->s_header.h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER); |
1219 | sb->s_header.h_blocktype = cpu_to_be32(JBD2_SUPERBLOCK_V2); | |
470decc6 DK |
1220 | |
1221 | sb->s_blocksize = cpu_to_be32(journal->j_blocksize); | |
1222 | sb->s_maxlen = cpu_to_be32(journal->j_maxlen); | |
1223 | sb->s_first = cpu_to_be32(1); | |
1224 | ||
1225 | journal->j_transaction_sequence = 1; | |
1226 | ||
f7f4bccb | 1227 | journal->j_flags &= ~JBD2_ABORT; |
470decc6 DK |
1228 | journal->j_format_version = 2; |
1229 | ||
1230 | return journal_reset(journal); | |
1231 | } | |
1232 | ||
1233 | /** | |
f7f4bccb | 1234 | * void jbd2_journal_update_superblock() - Update journal sb on disk. |
470decc6 DK |
1235 | * @journal: The journal to update. |
1236 | * @wait: Set to '0' if you don't want to wait for IO completion. | |
1237 | * | |
1238 | * Update a journal's dynamic superblock fields and write it to disk, | |
1239 | * optionally waiting for the IO to complete. | |
1240 | */ | |
f7f4bccb | 1241 | void jbd2_journal_update_superblock(journal_t *journal, int wait) |
470decc6 DK |
1242 | { |
1243 | journal_superblock_t *sb = journal->j_superblock; | |
1244 | struct buffer_head *bh = journal->j_sb_buffer; | |
1245 | ||
1246 | /* | |
1247 | * As a special case, if the on-disk copy is already marked as needing | |
1248 | * no recovery (s_start == 0) and there are no outstanding transactions | |
1249 | * in the filesystem, then we can safely defer the superblock update | |
f7f4bccb | 1250 | * until the next commit by setting JBD2_FLUSHED. This avoids |
470decc6 DK |
1251 | * attempting a write to a potential-readonly device. |
1252 | */ | |
1253 | if (sb->s_start == 0 && journal->j_tail_sequence == | |
1254 | journal->j_transaction_sequence) { | |
1255 | jbd_debug(1,"JBD: Skipping superblock update on recovered sb " | |
1256 | "(start %ld, seq %d, errno %d)\n", | |
1257 | journal->j_tail, journal->j_tail_sequence, | |
1258 | journal->j_errno); | |
1259 | goto out; | |
1260 | } | |
1261 | ||
1262 | spin_lock(&journal->j_state_lock); | |
1263 | jbd_debug(1,"JBD: updating superblock (start %ld, seq %d, errno %d)\n", | |
1264 | journal->j_tail, journal->j_tail_sequence, journal->j_errno); | |
1265 | ||
1266 | sb->s_sequence = cpu_to_be32(journal->j_tail_sequence); | |
1267 | sb->s_start = cpu_to_be32(journal->j_tail); | |
1268 | sb->s_errno = cpu_to_be32(journal->j_errno); | |
1269 | spin_unlock(&journal->j_state_lock); | |
1270 | ||
1271 | BUFFER_TRACE(bh, "marking dirty"); | |
1272 | mark_buffer_dirty(bh); | |
1273 | if (wait) | |
1274 | sync_dirty_buffer(bh); | |
1275 | else | |
1276 | ll_rw_block(SWRITE, 1, &bh); | |
1277 | ||
1278 | out: | |
1279 | /* If we have just flushed the log (by marking s_start==0), then | |
1280 | * any future commit will have to be careful to update the | |
1281 | * superblock again to re-record the true start of the log. */ | |
1282 | ||
1283 | spin_lock(&journal->j_state_lock); | |
1284 | if (sb->s_start) | |
f7f4bccb | 1285 | journal->j_flags &= ~JBD2_FLUSHED; |
470decc6 | 1286 | else |
f7f4bccb | 1287 | journal->j_flags |= JBD2_FLUSHED; |
470decc6 DK |
1288 | spin_unlock(&journal->j_state_lock); |
1289 | } | |
1290 | ||
1291 | /* | |
1292 | * Read the superblock for a given journal, performing initial | |
1293 | * validation of the format. | |
1294 | */ | |
1295 | ||
1296 | static int journal_get_superblock(journal_t *journal) | |
1297 | { | |
1298 | struct buffer_head *bh; | |
1299 | journal_superblock_t *sb; | |
1300 | int err = -EIO; | |
1301 | ||
1302 | bh = journal->j_sb_buffer; | |
1303 | ||
1304 | J_ASSERT(bh != NULL); | |
1305 | if (!buffer_uptodate(bh)) { | |
1306 | ll_rw_block(READ, 1, &bh); | |
1307 | wait_on_buffer(bh); | |
1308 | if (!buffer_uptodate(bh)) { | |
1309 | printk (KERN_ERR | |
1310 | "JBD: IO error reading journal superblock\n"); | |
1311 | goto out; | |
1312 | } | |
1313 | } | |
1314 | ||
1315 | sb = journal->j_superblock; | |
1316 | ||
1317 | err = -EINVAL; | |
1318 | ||
f7f4bccb | 1319 | if (sb->s_header.h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER) || |
470decc6 DK |
1320 | sb->s_blocksize != cpu_to_be32(journal->j_blocksize)) { |
1321 | printk(KERN_WARNING "JBD: no valid journal superblock found\n"); | |
1322 | goto out; | |
1323 | } | |
1324 | ||
1325 | switch(be32_to_cpu(sb->s_header.h_blocktype)) { | |
f7f4bccb | 1326 | case JBD2_SUPERBLOCK_V1: |
470decc6 DK |
1327 | journal->j_format_version = 1; |
1328 | break; | |
f7f4bccb | 1329 | case JBD2_SUPERBLOCK_V2: |
470decc6 DK |
1330 | journal->j_format_version = 2; |
1331 | break; | |
1332 | default: | |
1333 | printk(KERN_WARNING "JBD: unrecognised superblock format ID\n"); | |
1334 | goto out; | |
1335 | } | |
1336 | ||
1337 | if (be32_to_cpu(sb->s_maxlen) < journal->j_maxlen) | |
1338 | journal->j_maxlen = be32_to_cpu(sb->s_maxlen); | |
1339 | else if (be32_to_cpu(sb->s_maxlen) > journal->j_maxlen) { | |
1340 | printk (KERN_WARNING "JBD: journal file too short\n"); | |
1341 | goto out; | |
1342 | } | |
1343 | ||
1344 | return 0; | |
1345 | ||
1346 | out: | |
1347 | journal_fail_superblock(journal); | |
1348 | return err; | |
1349 | } | |
1350 | ||
1351 | /* | |
1352 | * Load the on-disk journal superblock and read the key fields into the | |
1353 | * journal_t. | |
1354 | */ | |
1355 | ||
1356 | static int load_superblock(journal_t *journal) | |
1357 | { | |
1358 | int err; | |
1359 | journal_superblock_t *sb; | |
1360 | ||
1361 | err = journal_get_superblock(journal); | |
1362 | if (err) | |
1363 | return err; | |
1364 | ||
1365 | sb = journal->j_superblock; | |
1366 | ||
1367 | journal->j_tail_sequence = be32_to_cpu(sb->s_sequence); | |
1368 | journal->j_tail = be32_to_cpu(sb->s_start); | |
1369 | journal->j_first = be32_to_cpu(sb->s_first); | |
1370 | journal->j_last = be32_to_cpu(sb->s_maxlen); | |
1371 | journal->j_errno = be32_to_cpu(sb->s_errno); | |
1372 | ||
1373 | return 0; | |
1374 | } | |
1375 | ||
1376 | ||
1377 | /** | |
f7f4bccb | 1378 | * int jbd2_journal_load() - Read journal from disk. |
470decc6 DK |
1379 | * @journal: Journal to act on. |
1380 | * | |
1381 | * Given a journal_t structure which tells us which disk blocks contain | |
1382 | * a journal, read the journal from disk to initialise the in-memory | |
1383 | * structures. | |
1384 | */ | |
f7f4bccb | 1385 | int jbd2_journal_load(journal_t *journal) |
470decc6 DK |
1386 | { |
1387 | int err; | |
1388 | journal_superblock_t *sb; | |
1389 | ||
1390 | err = load_superblock(journal); | |
1391 | if (err) | |
1392 | return err; | |
1393 | ||
1394 | sb = journal->j_superblock; | |
1395 | /* If this is a V2 superblock, then we have to check the | |
1396 | * features flags on it. */ | |
1397 | ||
1398 | if (journal->j_format_version >= 2) { | |
1399 | if ((sb->s_feature_ro_compat & | |
f7f4bccb | 1400 | ~cpu_to_be32(JBD2_KNOWN_ROCOMPAT_FEATURES)) || |
470decc6 | 1401 | (sb->s_feature_incompat & |
f7f4bccb | 1402 | ~cpu_to_be32(JBD2_KNOWN_INCOMPAT_FEATURES))) { |
470decc6 DK |
1403 | printk (KERN_WARNING |
1404 | "JBD: Unrecognised features on journal\n"); | |
1405 | return -EINVAL; | |
1406 | } | |
1407 | } | |
1408 | ||
470decc6 DK |
1409 | /* Let the recovery code check whether it needs to recover any |
1410 | * data from the journal. */ | |
f7f4bccb | 1411 | if (jbd2_journal_recover(journal)) |
470decc6 DK |
1412 | goto recovery_error; |
1413 | ||
1414 | /* OK, we've finished with the dynamic journal bits: | |
1415 | * reinitialise the dynamic contents of the superblock in memory | |
1416 | * and reset them on disk. */ | |
1417 | if (journal_reset(journal)) | |
1418 | goto recovery_error; | |
1419 | ||
f7f4bccb MC |
1420 | journal->j_flags &= ~JBD2_ABORT; |
1421 | journal->j_flags |= JBD2_LOADED; | |
470decc6 DK |
1422 | return 0; |
1423 | ||
1424 | recovery_error: | |
1425 | printk (KERN_WARNING "JBD: recovery failed\n"); | |
1426 | return -EIO; | |
1427 | } | |
1428 | ||
1429 | /** | |
f7f4bccb | 1430 | * void jbd2_journal_destroy() - Release a journal_t structure. |
470decc6 DK |
1431 | * @journal: Journal to act on. |
1432 | * | |
1433 | * Release a journal_t structure once it is no longer in use by the | |
1434 | * journaled object. | |
1435 | */ | |
f7f4bccb | 1436 | void jbd2_journal_destroy(journal_t *journal) |
470decc6 DK |
1437 | { |
1438 | /* Wait for the commit thread to wake up and die. */ | |
1439 | journal_kill_thread(journal); | |
1440 | ||
1441 | /* Force a final log commit */ | |
1442 | if (journal->j_running_transaction) | |
f7f4bccb | 1443 | jbd2_journal_commit_transaction(journal); |
470decc6 DK |
1444 | |
1445 | /* Force any old transactions to disk */ | |
1446 | ||
1447 | /* Totally anal locking here... */ | |
1448 | spin_lock(&journal->j_list_lock); | |
1449 | while (journal->j_checkpoint_transactions != NULL) { | |
1450 | spin_unlock(&journal->j_list_lock); | |
f7f4bccb | 1451 | jbd2_log_do_checkpoint(journal); |
470decc6 DK |
1452 | spin_lock(&journal->j_list_lock); |
1453 | } | |
1454 | ||
1455 | J_ASSERT(journal->j_running_transaction == NULL); | |
1456 | J_ASSERT(journal->j_committing_transaction == NULL); | |
1457 | J_ASSERT(journal->j_checkpoint_transactions == NULL); | |
1458 | spin_unlock(&journal->j_list_lock); | |
1459 | ||
1460 | /* We can now mark the journal as empty. */ | |
1461 | journal->j_tail = 0; | |
1462 | journal->j_tail_sequence = ++journal->j_transaction_sequence; | |
1463 | if (journal->j_sb_buffer) { | |
f7f4bccb | 1464 | jbd2_journal_update_superblock(journal, 1); |
470decc6 DK |
1465 | brelse(journal->j_sb_buffer); |
1466 | } | |
1467 | ||
8e85fb3f JL |
1468 | if (journal->j_proc_entry) |
1469 | jbd2_stats_proc_exit(journal); | |
470decc6 DK |
1470 | if (journal->j_inode) |
1471 | iput(journal->j_inode); | |
1472 | if (journal->j_revoke) | |
f7f4bccb | 1473 | jbd2_journal_destroy_revoke(journal); |
470decc6 DK |
1474 | kfree(journal->j_wbuf); |
1475 | kfree(journal); | |
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); | |
f7f4bccb | 1701 | err = jbd2_log_do_checkpoint(journal); |
470decc6 DK |
1702 | spin_lock(&journal->j_list_lock); |
1703 | } | |
1704 | spin_unlock(&journal->j_list_lock); | |
f7f4bccb | 1705 | jbd2_cleanup_journal_tail(journal); |
470decc6 DK |
1706 | |
1707 | /* Finally, mark the journal as really needing no recovery. | |
1708 | * This sets s_start==0 in the underlying superblock, which is | |
1709 | * the magic code for a fully-recovered superblock. Any future | |
1710 | * commits of data to the journal will restore the current | |
1711 | * s_start value. */ | |
1712 | spin_lock(&journal->j_state_lock); | |
1713 | old_tail = journal->j_tail; | |
1714 | journal->j_tail = 0; | |
1715 | spin_unlock(&journal->j_state_lock); | |
f7f4bccb | 1716 | jbd2_journal_update_superblock(journal, 1); |
470decc6 DK |
1717 | spin_lock(&journal->j_state_lock); |
1718 | journal->j_tail = old_tail; | |
1719 | ||
1720 | J_ASSERT(!journal->j_running_transaction); | |
1721 | J_ASSERT(!journal->j_committing_transaction); | |
1722 | J_ASSERT(!journal->j_checkpoint_transactions); | |
1723 | J_ASSERT(journal->j_head == journal->j_tail); | |
1724 | J_ASSERT(journal->j_tail_sequence == journal->j_transaction_sequence); | |
1725 | spin_unlock(&journal->j_state_lock); | |
1726 | return err; | |
1727 | } | |
1728 | ||
1729 | /** | |
f7f4bccb | 1730 | * int jbd2_journal_wipe() - Wipe journal contents |
470decc6 DK |
1731 | * @journal: Journal to act on. |
1732 | * @write: flag (see below) | |
1733 | * | |
1734 | * Wipe out all of the contents of a journal, safely. This will produce | |
1735 | * a warning if the journal contains any valid recovery information. | |
f7f4bccb | 1736 | * Must be called between journal_init_*() and jbd2_journal_load(). |
470decc6 DK |
1737 | * |
1738 | * If 'write' is non-zero, then we wipe out the journal on disk; otherwise | |
1739 | * we merely suppress recovery. | |
1740 | */ | |
1741 | ||
f7f4bccb | 1742 | int jbd2_journal_wipe(journal_t *journal, int write) |
470decc6 DK |
1743 | { |
1744 | journal_superblock_t *sb; | |
1745 | int err = 0; | |
1746 | ||
f7f4bccb | 1747 | J_ASSERT (!(journal->j_flags & JBD2_LOADED)); |
470decc6 DK |
1748 | |
1749 | err = load_superblock(journal); | |
1750 | if (err) | |
1751 | return err; | |
1752 | ||
1753 | sb = journal->j_superblock; | |
1754 | ||
1755 | if (!journal->j_tail) | |
1756 | goto no_recovery; | |
1757 | ||
1758 | printk (KERN_WARNING "JBD: %s recovery information on journal\n", | |
1759 | write ? "Clearing" : "Ignoring"); | |
1760 | ||
f7f4bccb | 1761 | err = jbd2_journal_skip_recovery(journal); |
470decc6 | 1762 | if (write) |
f7f4bccb | 1763 | jbd2_journal_update_superblock(journal, 1); |
470decc6 DK |
1764 | |
1765 | no_recovery: | |
1766 | return err; | |
1767 | } | |
1768 | ||
1769 | /* | |
1770 | * journal_dev_name: format a character string to describe on what | |
1771 | * device this journal is present. | |
1772 | */ | |
1773 | ||
1774 | static const char *journal_dev_name(journal_t *journal, char *buffer) | |
1775 | { | |
1776 | struct block_device *bdev; | |
1777 | ||
1778 | if (journal->j_inode) | |
1779 | bdev = journal->j_inode->i_sb->s_bdev; | |
1780 | else | |
1781 | bdev = journal->j_dev; | |
1782 | ||
1783 | return bdevname(bdev, buffer); | |
1784 | } | |
1785 | ||
1786 | /* | |
1787 | * Journal abort has very specific semantics, which we describe | |
1788 | * for journal abort. | |
1789 | * | |
1790 | * Two internal function, which provide abort to te jbd layer | |
1791 | * itself are here. | |
1792 | */ | |
1793 | ||
1794 | /* | |
1795 | * Quick version for internal journal use (doesn't lock the journal). | |
1796 | * Aborts hard --- we mark the abort as occurred, but do _nothing_ else, | |
1797 | * and don't attempt to make any other journal updates. | |
1798 | */ | |
f7f4bccb | 1799 | void __jbd2_journal_abort_hard(journal_t *journal) |
470decc6 DK |
1800 | { |
1801 | transaction_t *transaction; | |
1802 | char b[BDEVNAME_SIZE]; | |
1803 | ||
f7f4bccb | 1804 | if (journal->j_flags & JBD2_ABORT) |
470decc6 DK |
1805 | return; |
1806 | ||
1807 | printk(KERN_ERR "Aborting journal on device %s.\n", | |
1808 | journal_dev_name(journal, b)); | |
1809 | ||
1810 | spin_lock(&journal->j_state_lock); | |
f7f4bccb | 1811 | journal->j_flags |= JBD2_ABORT; |
470decc6 DK |
1812 | transaction = journal->j_running_transaction; |
1813 | if (transaction) | |
f7f4bccb | 1814 | __jbd2_log_start_commit(journal, transaction->t_tid); |
470decc6 DK |
1815 | spin_unlock(&journal->j_state_lock); |
1816 | } | |
1817 | ||
1818 | /* Soft abort: record the abort error status in the journal superblock, | |
1819 | * but don't do any other IO. */ | |
1820 | static void __journal_abort_soft (journal_t *journal, int errno) | |
1821 | { | |
f7f4bccb | 1822 | if (journal->j_flags & JBD2_ABORT) |
470decc6 DK |
1823 | return; |
1824 | ||
1825 | if (!journal->j_errno) | |
1826 | journal->j_errno = errno; | |
1827 | ||
f7f4bccb | 1828 | __jbd2_journal_abort_hard(journal); |
470decc6 DK |
1829 | |
1830 | if (errno) | |
f7f4bccb | 1831 | jbd2_journal_update_superblock(journal, 1); |
470decc6 DK |
1832 | } |
1833 | ||
1834 | /** | |
f7f4bccb | 1835 | * void jbd2_journal_abort () - Shutdown the journal immediately. |
470decc6 DK |
1836 | * @journal: the journal to shutdown. |
1837 | * @errno: an error number to record in the journal indicating | |
1838 | * the reason for the shutdown. | |
1839 | * | |
1840 | * Perform a complete, immediate shutdown of the ENTIRE | |
1841 | * journal (not of a single transaction). This operation cannot be | |
1842 | * undone without closing and reopening the journal. | |
1843 | * | |
f7f4bccb | 1844 | * The jbd2_journal_abort function is intended to support higher level error |
470decc6 DK |
1845 | * recovery mechanisms such as the ext2/ext3 remount-readonly error |
1846 | * mode. | |
1847 | * | |
1848 | * Journal abort has very specific semantics. Any existing dirty, | |
1849 | * unjournaled buffers in the main filesystem will still be written to | |
1850 | * disk by bdflush, but the journaling mechanism will be suspended | |
1851 | * immediately and no further transaction commits will be honoured. | |
1852 | * | |
1853 | * Any dirty, journaled buffers will be written back to disk without | |
1854 | * hitting the journal. Atomicity cannot be guaranteed on an aborted | |
1855 | * filesystem, but we _do_ attempt to leave as much data as possible | |
1856 | * behind for fsck to use for cleanup. | |
1857 | * | |
1858 | * Any attempt to get a new transaction handle on a journal which is in | |
1859 | * ABORT state will just result in an -EROFS error return. A | |
f7f4bccb | 1860 | * jbd2_journal_stop on an existing handle will return -EIO if we have |
470decc6 DK |
1861 | * entered abort state during the update. |
1862 | * | |
1863 | * Recursive transactions are not disturbed by journal abort until the | |
f7f4bccb | 1864 | * final jbd2_journal_stop, which will receive the -EIO error. |
470decc6 | 1865 | * |
f7f4bccb | 1866 | * Finally, the jbd2_journal_abort call allows the caller to supply an errno |
470decc6 DK |
1867 | * which will be recorded (if possible) in the journal superblock. This |
1868 | * allows a client to record failure conditions in the middle of a | |
1869 | * transaction without having to complete the transaction to record the | |
1870 | * failure to disk. ext3_error, for example, now uses this | |
1871 | * functionality. | |
1872 | * | |
1873 | * Errors which originate from within the journaling layer will NOT | |
1874 | * supply an errno; a null errno implies that absolutely no further | |
1875 | * writes are done to the journal (unless there are any already in | |
1876 | * progress). | |
1877 | * | |
1878 | */ | |
1879 | ||
f7f4bccb | 1880 | void jbd2_journal_abort(journal_t *journal, int errno) |
470decc6 DK |
1881 | { |
1882 | __journal_abort_soft(journal, errno); | |
1883 | } | |
1884 | ||
1885 | /** | |
f7f4bccb | 1886 | * int jbd2_journal_errno () - returns the journal's error state. |
470decc6 DK |
1887 | * @journal: journal to examine. |
1888 | * | |
f7f4bccb | 1889 | * This is the errno numbet set with jbd2_journal_abort(), the last |
470decc6 DK |
1890 | * time the journal was mounted - if the journal was stopped |
1891 | * without calling abort this will be 0. | |
1892 | * | |
1893 | * If the journal has been aborted on this mount time -EROFS will | |
1894 | * be returned. | |
1895 | */ | |
f7f4bccb | 1896 | int jbd2_journal_errno(journal_t *journal) |
470decc6 DK |
1897 | { |
1898 | int err; | |
1899 | ||
1900 | spin_lock(&journal->j_state_lock); | |
f7f4bccb | 1901 | if (journal->j_flags & JBD2_ABORT) |
470decc6 DK |
1902 | err = -EROFS; |
1903 | else | |
1904 | err = journal->j_errno; | |
1905 | spin_unlock(&journal->j_state_lock); | |
1906 | return err; | |
1907 | } | |
1908 | ||
1909 | /** | |
f7f4bccb | 1910 | * int jbd2_journal_clear_err () - clears the journal's error state |
470decc6 DK |
1911 | * @journal: journal to act on. |
1912 | * | |
1913 | * An error must be cleared or Acked to take a FS out of readonly | |
1914 | * mode. | |
1915 | */ | |
f7f4bccb | 1916 | int jbd2_journal_clear_err(journal_t *journal) |
470decc6 DK |
1917 | { |
1918 | int err = 0; | |
1919 | ||
1920 | spin_lock(&journal->j_state_lock); | |
f7f4bccb | 1921 | if (journal->j_flags & JBD2_ABORT) |
470decc6 DK |
1922 | err = -EROFS; |
1923 | else | |
1924 | journal->j_errno = 0; | |
1925 | spin_unlock(&journal->j_state_lock); | |
1926 | return err; | |
1927 | } | |
1928 | ||
1929 | /** | |
f7f4bccb | 1930 | * void jbd2_journal_ack_err() - Ack journal err. |
470decc6 DK |
1931 | * @journal: journal to act on. |
1932 | * | |
1933 | * An error must be cleared or Acked to take a FS out of readonly | |
1934 | * mode. | |
1935 | */ | |
f7f4bccb | 1936 | void jbd2_journal_ack_err(journal_t *journal) |
470decc6 DK |
1937 | { |
1938 | spin_lock(&journal->j_state_lock); | |
1939 | if (journal->j_errno) | |
f7f4bccb | 1940 | journal->j_flags |= JBD2_ACK_ERR; |
470decc6 DK |
1941 | spin_unlock(&journal->j_state_lock); |
1942 | } | |
1943 | ||
f7f4bccb | 1944 | int jbd2_journal_blocks_per_page(struct inode *inode) |
470decc6 DK |
1945 | { |
1946 | return 1 << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits); | |
1947 | } | |
1948 | ||
b517bea1 ZB |
1949 | /* |
1950 | * helper functions to deal with 32 or 64bit block numbers. | |
1951 | */ | |
1952 | size_t journal_tag_bytes(journal_t *journal) | |
1953 | { | |
1954 | if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT)) | |
cd02ff0b | 1955 | return JBD2_TAG_SIZE64; |
b517bea1 | 1956 | else |
cd02ff0b | 1957 | return JBD2_TAG_SIZE32; |
b517bea1 ZB |
1958 | } |
1959 | ||
470decc6 DK |
1960 | /* |
1961 | * Journal_head storage management | |
1962 | */ | |
e18b890b | 1963 | static struct kmem_cache *jbd2_journal_head_cache; |
e23291b9 | 1964 | #ifdef CONFIG_JBD2_DEBUG |
470decc6 DK |
1965 | static atomic_t nr_journal_heads = ATOMIC_INIT(0); |
1966 | #endif | |
1967 | ||
f7f4bccb | 1968 | static int journal_init_jbd2_journal_head_cache(void) |
470decc6 DK |
1969 | { |
1970 | int retval; | |
1971 | ||
f7f4bccb | 1972 | J_ASSERT(jbd2_journal_head_cache == 0); |
a920e941 | 1973 | jbd2_journal_head_cache = kmem_cache_create("jbd2_journal_head", |
470decc6 DK |
1974 | sizeof(struct journal_head), |
1975 | 0, /* offset */ | |
1976 | 0, /* flags */ | |
20c2df83 | 1977 | NULL); /* ctor */ |
470decc6 | 1978 | retval = 0; |
f7f4bccb | 1979 | if (jbd2_journal_head_cache == 0) { |
470decc6 DK |
1980 | retval = -ENOMEM; |
1981 | printk(KERN_EMERG "JBD: no memory for journal_head cache\n"); | |
1982 | } | |
1983 | return retval; | |
1984 | } | |
1985 | ||
f7f4bccb | 1986 | static void jbd2_journal_destroy_jbd2_journal_head_cache(void) |
470decc6 | 1987 | { |
f7f4bccb MC |
1988 | J_ASSERT(jbd2_journal_head_cache != NULL); |
1989 | kmem_cache_destroy(jbd2_journal_head_cache); | |
1990 | jbd2_journal_head_cache = NULL; | |
470decc6 DK |
1991 | } |
1992 | ||
1993 | /* | |
1994 | * journal_head splicing and dicing | |
1995 | */ | |
1996 | static struct journal_head *journal_alloc_journal_head(void) | |
1997 | { | |
1998 | struct journal_head *ret; | |
1999 | static unsigned long last_warning; | |
2000 | ||
e23291b9 | 2001 | #ifdef CONFIG_JBD2_DEBUG |
470decc6 DK |
2002 | atomic_inc(&nr_journal_heads); |
2003 | #endif | |
f7f4bccb | 2004 | ret = kmem_cache_alloc(jbd2_journal_head_cache, GFP_NOFS); |
470decc6 DK |
2005 | if (ret == 0) { |
2006 | jbd_debug(1, "out of memory for journal_head\n"); | |
2007 | if (time_after(jiffies, last_warning + 5*HZ)) { | |
2008 | printk(KERN_NOTICE "ENOMEM in %s, retrying.\n", | |
2009 | __FUNCTION__); | |
2010 | last_warning = jiffies; | |
2011 | } | |
2012 | while (ret == 0) { | |
2013 | yield(); | |
f7f4bccb | 2014 | ret = kmem_cache_alloc(jbd2_journal_head_cache, GFP_NOFS); |
470decc6 DK |
2015 | } |
2016 | } | |
2017 | return ret; | |
2018 | } | |
2019 | ||
2020 | static void journal_free_journal_head(struct journal_head *jh) | |
2021 | { | |
e23291b9 | 2022 | #ifdef CONFIG_JBD2_DEBUG |
470decc6 | 2023 | atomic_dec(&nr_journal_heads); |
cd02ff0b | 2024 | memset(jh, JBD2_POISON_FREE, sizeof(*jh)); |
470decc6 | 2025 | #endif |
f7f4bccb | 2026 | kmem_cache_free(jbd2_journal_head_cache, jh); |
470decc6 DK |
2027 | } |
2028 | ||
2029 | /* | |
2030 | * A journal_head is attached to a buffer_head whenever JBD has an | |
2031 | * interest in the buffer. | |
2032 | * | |
2033 | * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit | |
2034 | * is set. This bit is tested in core kernel code where we need to take | |
2035 | * JBD-specific actions. Testing the zeroness of ->b_private is not reliable | |
2036 | * there. | |
2037 | * | |
2038 | * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one. | |
2039 | * | |
2040 | * When a buffer has its BH_JBD bit set it is immune from being released by | |
2041 | * core kernel code, mainly via ->b_count. | |
2042 | * | |
2043 | * A journal_head may be detached from its buffer_head when the journal_head's | |
2044 | * b_transaction, b_cp_transaction and b_next_transaction pointers are NULL. | |
f7f4bccb | 2045 | * Various places in JBD call jbd2_journal_remove_journal_head() to indicate that the |
470decc6 DK |
2046 | * journal_head can be dropped if needed. |
2047 | * | |
2048 | * Various places in the kernel want to attach a journal_head to a buffer_head | |
2049 | * _before_ attaching the journal_head to a transaction. To protect the | |
f7f4bccb | 2050 | * journal_head in this situation, jbd2_journal_add_journal_head elevates the |
470decc6 | 2051 | * journal_head's b_jcount refcount by one. The caller must call |
f7f4bccb | 2052 | * jbd2_journal_put_journal_head() to undo this. |
470decc6 DK |
2053 | * |
2054 | * So the typical usage would be: | |
2055 | * | |
2056 | * (Attach a journal_head if needed. Increments b_jcount) | |
f7f4bccb | 2057 | * struct journal_head *jh = jbd2_journal_add_journal_head(bh); |
470decc6 DK |
2058 | * ... |
2059 | * jh->b_transaction = xxx; | |
f7f4bccb | 2060 | * jbd2_journal_put_journal_head(jh); |
470decc6 DK |
2061 | * |
2062 | * Now, the journal_head's b_jcount is zero, but it is safe from being released | |
2063 | * because it has a non-zero b_transaction. | |
2064 | */ | |
2065 | ||
2066 | /* | |
2067 | * Give a buffer_head a journal_head. | |
2068 | * | |
2069 | * Doesn't need the journal lock. | |
2070 | * May sleep. | |
2071 | */ | |
f7f4bccb | 2072 | struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh) |
470decc6 DK |
2073 | { |
2074 | struct journal_head *jh; | |
2075 | struct journal_head *new_jh = NULL; | |
2076 | ||
2077 | repeat: | |
2078 | if (!buffer_jbd(bh)) { | |
2079 | new_jh = journal_alloc_journal_head(); | |
2080 | memset(new_jh, 0, sizeof(*new_jh)); | |
2081 | } | |
2082 | ||
2083 | jbd_lock_bh_journal_head(bh); | |
2084 | if (buffer_jbd(bh)) { | |
2085 | jh = bh2jh(bh); | |
2086 | } else { | |
2087 | J_ASSERT_BH(bh, | |
2088 | (atomic_read(&bh->b_count) > 0) || | |
2089 | (bh->b_page && bh->b_page->mapping)); | |
2090 | ||
2091 | if (!new_jh) { | |
2092 | jbd_unlock_bh_journal_head(bh); | |
2093 | goto repeat; | |
2094 | } | |
2095 | ||
2096 | jh = new_jh; | |
2097 | new_jh = NULL; /* We consumed it */ | |
2098 | set_buffer_jbd(bh); | |
2099 | bh->b_private = jh; | |
2100 | jh->b_bh = bh; | |
2101 | get_bh(bh); | |
2102 | BUFFER_TRACE(bh, "added journal_head"); | |
2103 | } | |
2104 | jh->b_jcount++; | |
2105 | jbd_unlock_bh_journal_head(bh); | |
2106 | if (new_jh) | |
2107 | journal_free_journal_head(new_jh); | |
2108 | return bh->b_private; | |
2109 | } | |
2110 | ||
2111 | /* | |
2112 | * Grab a ref against this buffer_head's journal_head. If it ended up not | |
2113 | * having a journal_head, return NULL | |
2114 | */ | |
f7f4bccb | 2115 | struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh) |
470decc6 DK |
2116 | { |
2117 | struct journal_head *jh = NULL; | |
2118 | ||
2119 | jbd_lock_bh_journal_head(bh); | |
2120 | if (buffer_jbd(bh)) { | |
2121 | jh = bh2jh(bh); | |
2122 | jh->b_jcount++; | |
2123 | } | |
2124 | jbd_unlock_bh_journal_head(bh); | |
2125 | return jh; | |
2126 | } | |
2127 | ||
2128 | static void __journal_remove_journal_head(struct buffer_head *bh) | |
2129 | { | |
2130 | struct journal_head *jh = bh2jh(bh); | |
2131 | ||
2132 | J_ASSERT_JH(jh, jh->b_jcount >= 0); | |
2133 | ||
2134 | get_bh(bh); | |
2135 | if (jh->b_jcount == 0) { | |
2136 | if (jh->b_transaction == NULL && | |
2137 | jh->b_next_transaction == NULL && | |
2138 | jh->b_cp_transaction == NULL) { | |
2139 | J_ASSERT_JH(jh, jh->b_jlist == BJ_None); | |
2140 | J_ASSERT_BH(bh, buffer_jbd(bh)); | |
2141 | J_ASSERT_BH(bh, jh2bh(jh) == bh); | |
2142 | BUFFER_TRACE(bh, "remove journal_head"); | |
2143 | if (jh->b_frozen_data) { | |
2144 | printk(KERN_WARNING "%s: freeing " | |
2145 | "b_frozen_data\n", | |
2146 | __FUNCTION__); | |
af1e76d6 | 2147 | jbd2_free(jh->b_frozen_data, bh->b_size); |
470decc6 DK |
2148 | } |
2149 | if (jh->b_committed_data) { | |
2150 | printk(KERN_WARNING "%s: freeing " | |
2151 | "b_committed_data\n", | |
2152 | __FUNCTION__); | |
af1e76d6 | 2153 | jbd2_free(jh->b_committed_data, bh->b_size); |
470decc6 DK |
2154 | } |
2155 | bh->b_private = NULL; | |
2156 | jh->b_bh = NULL; /* debug, really */ | |
2157 | clear_buffer_jbd(bh); | |
2158 | __brelse(bh); | |
2159 | journal_free_journal_head(jh); | |
2160 | } else { | |
2161 | BUFFER_TRACE(bh, "journal_head was locked"); | |
2162 | } | |
2163 | } | |
2164 | } | |
2165 | ||
2166 | /* | |
f7f4bccb | 2167 | * jbd2_journal_remove_journal_head(): if the buffer isn't attached to a transaction |
470decc6 DK |
2168 | * and has a zero b_jcount then remove and release its journal_head. If we did |
2169 | * see that the buffer is not used by any transaction we also "logically" | |
2170 | * decrement ->b_count. | |
2171 | * | |
2172 | * We in fact take an additional increment on ->b_count as a convenience, | |
2173 | * because the caller usually wants to do additional things with the bh | |
2174 | * after calling here. | |
f7f4bccb | 2175 | * The caller of jbd2_journal_remove_journal_head() *must* run __brelse(bh) at some |
470decc6 DK |
2176 | * time. Once the caller has run __brelse(), the buffer is eligible for |
2177 | * reaping by try_to_free_buffers(). | |
2178 | */ | |
f7f4bccb | 2179 | void jbd2_journal_remove_journal_head(struct buffer_head *bh) |
470decc6 DK |
2180 | { |
2181 | jbd_lock_bh_journal_head(bh); | |
2182 | __journal_remove_journal_head(bh); | |
2183 | jbd_unlock_bh_journal_head(bh); | |
2184 | } | |
2185 | ||
2186 | /* | |
2187 | * Drop a reference on the passed journal_head. If it fell to zero then try to | |
2188 | * release the journal_head from the buffer_head. | |
2189 | */ | |
f7f4bccb | 2190 | void jbd2_journal_put_journal_head(struct journal_head *jh) |
470decc6 DK |
2191 | { |
2192 | struct buffer_head *bh = jh2bh(jh); | |
2193 | ||
2194 | jbd_lock_bh_journal_head(bh); | |
2195 | J_ASSERT_JH(jh, jh->b_jcount > 0); | |
2196 | --jh->b_jcount; | |
2197 | if (!jh->b_jcount && !jh->b_transaction) { | |
2198 | __journal_remove_journal_head(bh); | |
2199 | __brelse(bh); | |
2200 | } | |
2201 | jbd_unlock_bh_journal_head(bh); | |
2202 | } | |
2203 | ||
2204 | /* | |
0f49d5d0 | 2205 | * debugfs tunables |
470decc6 | 2206 | */ |
6f38c74f JS |
2207 | #ifdef CONFIG_JBD2_DEBUG |
2208 | u8 jbd2_journal_enable_debug __read_mostly; | |
f7f4bccb | 2209 | EXPORT_SYMBOL(jbd2_journal_enable_debug); |
470decc6 | 2210 | |
0f49d5d0 | 2211 | #define JBD2_DEBUG_NAME "jbd2-debug" |
470decc6 | 2212 | |
6f38c74f JS |
2213 | static struct dentry *jbd2_debugfs_dir; |
2214 | static struct dentry *jbd2_debug; | |
470decc6 | 2215 | |
0f49d5d0 JS |
2216 | static void __init jbd2_create_debugfs_entry(void) |
2217 | { | |
2218 | jbd2_debugfs_dir = debugfs_create_dir("jbd2", NULL); | |
2219 | if (jbd2_debugfs_dir) | |
2220 | jbd2_debug = debugfs_create_u8(JBD2_DEBUG_NAME, S_IRUGO, | |
2221 | jbd2_debugfs_dir, | |
2222 | &jbd2_journal_enable_debug); | |
470decc6 DK |
2223 | } |
2224 | ||
0f49d5d0 | 2225 | static void __exit jbd2_remove_debugfs_entry(void) |
470decc6 | 2226 | { |
6f38c74f JS |
2227 | debugfs_remove(jbd2_debug); |
2228 | debugfs_remove(jbd2_debugfs_dir); | |
470decc6 DK |
2229 | } |
2230 | ||
0f49d5d0 | 2231 | #else |
470decc6 | 2232 | |
0f49d5d0 | 2233 | static void __init jbd2_create_debugfs_entry(void) |
470decc6 | 2234 | { |
470decc6 DK |
2235 | } |
2236 | ||
0f49d5d0 | 2237 | static void __exit jbd2_remove_debugfs_entry(void) |
470decc6 | 2238 | { |
470decc6 DK |
2239 | } |
2240 | ||
470decc6 DK |
2241 | #endif |
2242 | ||
8e85fb3f JL |
2243 | #ifdef CONFIG_PROC_FS |
2244 | ||
2245 | #define JBD2_STATS_PROC_NAME "fs/jbd2" | |
2246 | ||
2247 | static void __init jbd2_create_jbd_stats_proc_entry(void) | |
2248 | { | |
2249 | proc_jbd2_stats = proc_mkdir(JBD2_STATS_PROC_NAME, NULL); | |
2250 | } | |
2251 | ||
2252 | static void __exit jbd2_remove_jbd_stats_proc_entry(void) | |
2253 | { | |
2254 | if (proc_jbd2_stats) | |
2255 | remove_proc_entry(JBD2_STATS_PROC_NAME, NULL); | |
2256 | } | |
2257 | ||
2258 | #else | |
2259 | ||
2260 | #define jbd2_create_jbd_stats_proc_entry() do {} while (0) | |
2261 | #define jbd2_remove_jbd_stats_proc_entry() do {} while (0) | |
2262 | ||
2263 | #endif | |
2264 | ||
e18b890b | 2265 | struct kmem_cache *jbd2_handle_cache; |
470decc6 DK |
2266 | |
2267 | static int __init journal_init_handle_cache(void) | |
2268 | { | |
a920e941 | 2269 | jbd2_handle_cache = kmem_cache_create("jbd2_journal_handle", |
470decc6 DK |
2270 | sizeof(handle_t), |
2271 | 0, /* offset */ | |
2272 | 0, /* flags */ | |
20c2df83 | 2273 | NULL); /* ctor */ |
f7f4bccb | 2274 | if (jbd2_handle_cache == NULL) { |
470decc6 DK |
2275 | printk(KERN_EMERG "JBD: failed to create handle cache\n"); |
2276 | return -ENOMEM; | |
2277 | } | |
2278 | return 0; | |
2279 | } | |
2280 | ||
f7f4bccb | 2281 | static void jbd2_journal_destroy_handle_cache(void) |
470decc6 | 2282 | { |
f7f4bccb MC |
2283 | if (jbd2_handle_cache) |
2284 | kmem_cache_destroy(jbd2_handle_cache); | |
470decc6 DK |
2285 | } |
2286 | ||
2287 | /* | |
2288 | * Module startup and shutdown | |
2289 | */ | |
2290 | ||
2291 | static int __init journal_init_caches(void) | |
2292 | { | |
2293 | int ret; | |
2294 | ||
f7f4bccb | 2295 | ret = jbd2_journal_init_revoke_caches(); |
470decc6 | 2296 | if (ret == 0) |
f7f4bccb | 2297 | ret = journal_init_jbd2_journal_head_cache(); |
470decc6 DK |
2298 | if (ret == 0) |
2299 | ret = journal_init_handle_cache(); | |
2300 | return ret; | |
2301 | } | |
2302 | ||
f7f4bccb | 2303 | static void jbd2_journal_destroy_caches(void) |
470decc6 | 2304 | { |
f7f4bccb MC |
2305 | jbd2_journal_destroy_revoke_caches(); |
2306 | jbd2_journal_destroy_jbd2_journal_head_cache(); | |
2307 | jbd2_journal_destroy_handle_cache(); | |
470decc6 DK |
2308 | } |
2309 | ||
2310 | static int __init journal_init(void) | |
2311 | { | |
2312 | int ret; | |
2313 | ||
2314 | BUILD_BUG_ON(sizeof(struct journal_superblock_s) != 1024); | |
2315 | ||
2316 | ret = journal_init_caches(); | |
2317 | if (ret != 0) | |
f7f4bccb | 2318 | jbd2_journal_destroy_caches(); |
0f49d5d0 | 2319 | jbd2_create_debugfs_entry(); |
8e85fb3f | 2320 | jbd2_create_jbd_stats_proc_entry(); |
470decc6 DK |
2321 | return ret; |
2322 | } | |
2323 | ||
2324 | static void __exit journal_exit(void) | |
2325 | { | |
e23291b9 | 2326 | #ifdef CONFIG_JBD2_DEBUG |
470decc6 DK |
2327 | int n = atomic_read(&nr_journal_heads); |
2328 | if (n) | |
2329 | printk(KERN_EMERG "JBD: leaked %d journal_heads!\n", n); | |
2330 | #endif | |
0f49d5d0 | 2331 | jbd2_remove_debugfs_entry(); |
8e85fb3f | 2332 | jbd2_remove_jbd_stats_proc_entry(); |
f7f4bccb | 2333 | jbd2_journal_destroy_caches(); |
470decc6 DK |
2334 | } |
2335 | ||
2336 | MODULE_LICENSE("GPL"); | |
2337 | module_init(journal_init); | |
2338 | module_exit(journal_exit); | |
2339 |