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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); | |
f7f4bccb MC |
53 | EXPORT_SYMBOL(jbd2_journal_dirty_metadata); |
54 | EXPORT_SYMBOL(jbd2_journal_release_buffer); | |
55 | EXPORT_SYMBOL(jbd2_journal_forget); | |
470decc6 DK |
56 | #if 0 |
57 | EXPORT_SYMBOL(journal_sync_buffer); | |
58 | #endif | |
f7f4bccb MC |
59 | EXPORT_SYMBOL(jbd2_journal_flush); |
60 | EXPORT_SYMBOL(jbd2_journal_revoke); | |
61 | ||
62 | EXPORT_SYMBOL(jbd2_journal_init_dev); | |
63 | EXPORT_SYMBOL(jbd2_journal_init_inode); | |
64 | EXPORT_SYMBOL(jbd2_journal_update_format); | |
65 | EXPORT_SYMBOL(jbd2_journal_check_used_features); | |
66 | EXPORT_SYMBOL(jbd2_journal_check_available_features); | |
67 | EXPORT_SYMBOL(jbd2_journal_set_features); | |
68 | EXPORT_SYMBOL(jbd2_journal_create); | |
69 | EXPORT_SYMBOL(jbd2_journal_load); | |
70 | EXPORT_SYMBOL(jbd2_journal_destroy); | |
f7f4bccb MC |
71 | EXPORT_SYMBOL(jbd2_journal_abort); |
72 | EXPORT_SYMBOL(jbd2_journal_errno); | |
73 | EXPORT_SYMBOL(jbd2_journal_ack_err); | |
74 | EXPORT_SYMBOL(jbd2_journal_clear_err); | |
75 | EXPORT_SYMBOL(jbd2_log_wait_commit); | |
76 | EXPORT_SYMBOL(jbd2_journal_start_commit); | |
77 | EXPORT_SYMBOL(jbd2_journal_force_commit_nested); | |
78 | EXPORT_SYMBOL(jbd2_journal_wipe); | |
79 | EXPORT_SYMBOL(jbd2_journal_blocks_per_page); | |
80 | EXPORT_SYMBOL(jbd2_journal_invalidatepage); | |
81 | EXPORT_SYMBOL(jbd2_journal_try_to_free_buffers); | |
82 | EXPORT_SYMBOL(jbd2_journal_force_commit); | |
c851ed54 JK |
83 | EXPORT_SYMBOL(jbd2_journal_file_inode); |
84 | EXPORT_SYMBOL(jbd2_journal_init_jbd_inode); | |
85 | EXPORT_SYMBOL(jbd2_journal_release_jbd_inode); | |
86 | EXPORT_SYMBOL(jbd2_journal_begin_ordered_truncate); | |
470decc6 DK |
87 | |
88 | static int journal_convert_superblock_v1(journal_t *, journal_superblock_t *); | |
89 | static void __journal_abort_soft (journal_t *journal, int errno); | |
470decc6 DK |
90 | |
91 | /* | |
92 | * Helper function used to manage commit timeouts | |
93 | */ | |
94 | ||
95 | static void commit_timeout(unsigned long __data) | |
96 | { | |
97 | struct task_struct * p = (struct task_struct *) __data; | |
98 | ||
99 | wake_up_process(p); | |
100 | } | |
101 | ||
102 | /* | |
f7f4bccb | 103 | * kjournald2: The main thread function used to manage a logging device |
470decc6 DK |
104 | * journal. |
105 | * | |
106 | * This kernel thread is responsible for two things: | |
107 | * | |
108 | * 1) COMMIT: Every so often we need to commit the current state of the | |
109 | * filesystem to disk. The journal thread is responsible for writing | |
110 | * all of the metadata buffers to disk. | |
111 | * | |
112 | * 2) CHECKPOINT: We cannot reuse a used section of the log file until all | |
113 | * of the data in that part of the log has been rewritten elsewhere on | |
114 | * the disk. Flushing these old buffers to reclaim space in the log is | |
115 | * known as checkpointing, and this thread is responsible for that job. | |
116 | */ | |
117 | ||
f7f4bccb | 118 | static int kjournald2(void *arg) |
470decc6 DK |
119 | { |
120 | journal_t *journal = arg; | |
121 | transaction_t *transaction; | |
122 | ||
123 | /* | |
124 | * Set up an interval timer which can be used to trigger a commit wakeup | |
125 | * after the commit interval expires | |
126 | */ | |
127 | setup_timer(&journal->j_commit_timer, commit_timeout, | |
128 | (unsigned long)current); | |
129 | ||
130 | /* Record that the journal thread is running */ | |
131 | journal->j_task = current; | |
132 | wake_up(&journal->j_wait_done_commit); | |
133 | ||
f7f4bccb | 134 | printk(KERN_INFO "kjournald2 starting. Commit interval %ld seconds\n", |
470decc6 DK |
135 | journal->j_commit_interval / HZ); |
136 | ||
137 | /* | |
138 | * And now, wait forever for commit wakeup events. | |
139 | */ | |
140 | spin_lock(&journal->j_state_lock); | |
141 | ||
142 | loop: | |
f7f4bccb | 143 | if (journal->j_flags & JBD2_UNMOUNT) |
470decc6 DK |
144 | goto end_loop; |
145 | ||
146 | jbd_debug(1, "commit_sequence=%d, commit_request=%d\n", | |
147 | journal->j_commit_sequence, journal->j_commit_request); | |
148 | ||
149 | if (journal->j_commit_sequence != journal->j_commit_request) { | |
150 | jbd_debug(1, "OK, requests differ\n"); | |
151 | spin_unlock(&journal->j_state_lock); | |
152 | del_timer_sync(&journal->j_commit_timer); | |
f7f4bccb | 153 | jbd2_journal_commit_transaction(journal); |
470decc6 DK |
154 | spin_lock(&journal->j_state_lock); |
155 | goto loop; | |
156 | } | |
157 | ||
158 | wake_up(&journal->j_wait_done_commit); | |
159 | if (freezing(current)) { | |
160 | /* | |
161 | * The simpler the better. Flushing journal isn't a | |
162 | * good idea, because that depends on threads that may | |
163 | * be already stopped. | |
164 | */ | |
f7f4bccb | 165 | jbd_debug(1, "Now suspending kjournald2\n"); |
470decc6 DK |
166 | spin_unlock(&journal->j_state_lock); |
167 | refrigerator(); | |
168 | spin_lock(&journal->j_state_lock); | |
169 | } else { | |
170 | /* | |
171 | * We assume on resume that commits are already there, | |
172 | * so we don't sleep | |
173 | */ | |
174 | DEFINE_WAIT(wait); | |
175 | int should_sleep = 1; | |
176 | ||
177 | prepare_to_wait(&journal->j_wait_commit, &wait, | |
178 | TASK_INTERRUPTIBLE); | |
179 | if (journal->j_commit_sequence != journal->j_commit_request) | |
180 | should_sleep = 0; | |
181 | transaction = journal->j_running_transaction; | |
182 | if (transaction && time_after_eq(jiffies, | |
183 | transaction->t_expires)) | |
184 | should_sleep = 0; | |
f7f4bccb | 185 | if (journal->j_flags & JBD2_UNMOUNT) |
470decc6 DK |
186 | should_sleep = 0; |
187 | if (should_sleep) { | |
188 | spin_unlock(&journal->j_state_lock); | |
189 | schedule(); | |
190 | spin_lock(&journal->j_state_lock); | |
191 | } | |
192 | finish_wait(&journal->j_wait_commit, &wait); | |
193 | } | |
194 | ||
f7f4bccb | 195 | jbd_debug(1, "kjournald2 wakes\n"); |
470decc6 DK |
196 | |
197 | /* | |
198 | * Were we woken up by a commit wakeup event? | |
199 | */ | |
200 | transaction = journal->j_running_transaction; | |
201 | if (transaction && time_after_eq(jiffies, transaction->t_expires)) { | |
202 | journal->j_commit_request = transaction->t_tid; | |
203 | jbd_debug(1, "woke because of timeout\n"); | |
204 | } | |
205 | goto loop; | |
206 | ||
207 | end_loop: | |
208 | spin_unlock(&journal->j_state_lock); | |
209 | del_timer_sync(&journal->j_commit_timer); | |
210 | journal->j_task = NULL; | |
211 | wake_up(&journal->j_wait_done_commit); | |
212 | jbd_debug(1, "Journal thread exiting.\n"); | |
213 | return 0; | |
214 | } | |
215 | ||
97f06784 | 216 | static int jbd2_journal_start_thread(journal_t *journal) |
470decc6 | 217 | { |
97f06784 PE |
218 | struct task_struct *t; |
219 | ||
220 | t = kthread_run(kjournald2, journal, "kjournald2"); | |
221 | if (IS_ERR(t)) | |
222 | return PTR_ERR(t); | |
223 | ||
1076d17a | 224 | wait_event(journal->j_wait_done_commit, journal->j_task != NULL); |
97f06784 | 225 | return 0; |
470decc6 DK |
226 | } |
227 | ||
228 | static void journal_kill_thread(journal_t *journal) | |
229 | { | |
230 | spin_lock(&journal->j_state_lock); | |
f7f4bccb | 231 | journal->j_flags |= JBD2_UNMOUNT; |
470decc6 DK |
232 | |
233 | while (journal->j_task) { | |
234 | wake_up(&journal->j_wait_commit); | |
235 | spin_unlock(&journal->j_state_lock); | |
1076d17a | 236 | wait_event(journal->j_wait_done_commit, journal->j_task == NULL); |
470decc6 DK |
237 | spin_lock(&journal->j_state_lock); |
238 | } | |
239 | spin_unlock(&journal->j_state_lock); | |
240 | } | |
241 | ||
242 | /* | |
f7f4bccb | 243 | * jbd2_journal_write_metadata_buffer: write a metadata buffer to the journal. |
470decc6 DK |
244 | * |
245 | * Writes a metadata buffer to a given disk block. The actual IO is not | |
246 | * performed but a new buffer_head is constructed which labels the data | |
247 | * to be written with the correct destination disk block. | |
248 | * | |
249 | * Any magic-number escaping which needs to be done will cause a | |
250 | * copy-out here. If the buffer happens to start with the | |
f7f4bccb | 251 | * JBD2_MAGIC_NUMBER, then we can't write it to the log directly: the |
470decc6 DK |
252 | * magic number is only written to the log for descripter blocks. In |
253 | * this case, we copy the data and replace the first word with 0, and we | |
254 | * return a result code which indicates that this buffer needs to be | |
255 | * marked as an escaped buffer in the corresponding log descriptor | |
256 | * block. The missing word can then be restored when the block is read | |
257 | * during recovery. | |
258 | * | |
259 | * If the source buffer has already been modified by a new transaction | |
260 | * since we took the last commit snapshot, we use the frozen copy of | |
261 | * that data for IO. If we end up using the existing buffer_head's data | |
262 | * for the write, then we *have* to lock the buffer to prevent anyone | |
263 | * else from using and possibly modifying it while the IO is in | |
264 | * progress. | |
265 | * | |
266 | * The function returns a pointer to the buffer_heads to be used for IO. | |
267 | * | |
268 | * We assume that the journal has already been locked in this function. | |
269 | * | |
270 | * Return value: | |
271 | * <0: Error | |
272 | * >=0: Finished OK | |
273 | * | |
274 | * On success: | |
275 | * Bit 0 set == escape performed on the data | |
276 | * Bit 1 set == buffer copy-out performed (kfree the data after IO) | |
277 | */ | |
278 | ||
f7f4bccb | 279 | int jbd2_journal_write_metadata_buffer(transaction_t *transaction, |
470decc6 DK |
280 | struct journal_head *jh_in, |
281 | struct journal_head **jh_out, | |
18eba7aa | 282 | unsigned long long blocknr) |
470decc6 DK |
283 | { |
284 | int need_copy_out = 0; | |
285 | int done_copy_out = 0; | |
286 | int do_escape = 0; | |
287 | char *mapped_data; | |
288 | struct buffer_head *new_bh; | |
289 | struct journal_head *new_jh; | |
290 | struct page *new_page; | |
291 | unsigned int new_offset; | |
292 | struct buffer_head *bh_in = jh2bh(jh_in); | |
293 | ||
294 | /* | |
295 | * The buffer really shouldn't be locked: only the current committing | |
296 | * transaction is allowed to write it, so nobody else is allowed | |
297 | * to do any IO. | |
298 | * | |
299 | * akpm: except if we're journalling data, and write() output is | |
300 | * also part of a shared mapping, and another thread has | |
301 | * decided to launch a writepage() against this buffer. | |
302 | */ | |
303 | J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in)); | |
304 | ||
305 | new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL); | |
306 | ||
307 | /* | |
308 | * If a new transaction has already done a buffer copy-out, then | |
309 | * we use that version of the data for the commit. | |
310 | */ | |
311 | jbd_lock_bh_state(bh_in); | |
312 | repeat: | |
313 | if (jh_in->b_frozen_data) { | |
314 | done_copy_out = 1; | |
315 | new_page = virt_to_page(jh_in->b_frozen_data); | |
316 | new_offset = offset_in_page(jh_in->b_frozen_data); | |
317 | } else { | |
318 | new_page = jh2bh(jh_in)->b_page; | |
319 | new_offset = offset_in_page(jh2bh(jh_in)->b_data); | |
320 | } | |
321 | ||
322 | mapped_data = kmap_atomic(new_page, KM_USER0); | |
323 | /* | |
324 | * Check for escaping | |
325 | */ | |
326 | if (*((__be32 *)(mapped_data + new_offset)) == | |
f7f4bccb | 327 | cpu_to_be32(JBD2_MAGIC_NUMBER)) { |
470decc6 DK |
328 | need_copy_out = 1; |
329 | do_escape = 1; | |
330 | } | |
331 | kunmap_atomic(mapped_data, KM_USER0); | |
332 | ||
333 | /* | |
334 | * Do we need to do a data copy? | |
335 | */ | |
336 | if (need_copy_out && !done_copy_out) { | |
337 | char *tmp; | |
338 | ||
339 | jbd_unlock_bh_state(bh_in); | |
af1e76d6 | 340 | tmp = jbd2_alloc(bh_in->b_size, GFP_NOFS); |
470decc6 DK |
341 | jbd_lock_bh_state(bh_in); |
342 | if (jh_in->b_frozen_data) { | |
af1e76d6 | 343 | jbd2_free(tmp, bh_in->b_size); |
470decc6 DK |
344 | goto repeat; |
345 | } | |
346 | ||
347 | jh_in->b_frozen_data = tmp; | |
348 | mapped_data = kmap_atomic(new_page, KM_USER0); | |
349 | memcpy(tmp, mapped_data + new_offset, jh2bh(jh_in)->b_size); | |
350 | kunmap_atomic(mapped_data, KM_USER0); | |
351 | ||
352 | new_page = virt_to_page(tmp); | |
353 | new_offset = offset_in_page(tmp); | |
354 | done_copy_out = 1; | |
355 | } | |
356 | ||
357 | /* | |
358 | * Did we need to do an escaping? Now we've done all the | |
359 | * copying, we can finally do so. | |
360 | */ | |
361 | if (do_escape) { | |
362 | mapped_data = kmap_atomic(new_page, KM_USER0); | |
363 | *((unsigned int *)(mapped_data + new_offset)) = 0; | |
364 | kunmap_atomic(mapped_data, KM_USER0); | |
365 | } | |
366 | ||
367 | /* keep subsequent assertions sane */ | |
368 | new_bh->b_state = 0; | |
369 | init_buffer(new_bh, NULL, NULL); | |
370 | atomic_set(&new_bh->b_count, 1); | |
371 | jbd_unlock_bh_state(bh_in); | |
372 | ||
f7f4bccb | 373 | new_jh = jbd2_journal_add_journal_head(new_bh); /* This sleeps */ |
470decc6 DK |
374 | |
375 | set_bh_page(new_bh, new_page, new_offset); | |
376 | new_jh->b_transaction = NULL; | |
377 | new_bh->b_size = jh2bh(jh_in)->b_size; | |
378 | new_bh->b_bdev = transaction->t_journal->j_dev; | |
379 | new_bh->b_blocknr = blocknr; | |
380 | set_buffer_mapped(new_bh); | |
381 | set_buffer_dirty(new_bh); | |
382 | ||
383 | *jh_out = new_jh; | |
384 | ||
385 | /* | |
386 | * The to-be-written buffer needs to get moved to the io queue, | |
387 | * and the original buffer whose contents we are shadowing or | |
388 | * copying is moved to the transaction's shadow queue. | |
389 | */ | |
390 | JBUFFER_TRACE(jh_in, "file as BJ_Shadow"); | |
f7f4bccb | 391 | jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow); |
470decc6 | 392 | JBUFFER_TRACE(new_jh, "file as BJ_IO"); |
f7f4bccb | 393 | jbd2_journal_file_buffer(new_jh, transaction, BJ_IO); |
470decc6 DK |
394 | |
395 | return do_escape | (done_copy_out << 1); | |
396 | } | |
397 | ||
398 | /* | |
399 | * Allocation code for the journal file. Manage the space left in the | |
400 | * journal, so that we can begin checkpointing when appropriate. | |
401 | */ | |
402 | ||
403 | /* | |
f7f4bccb | 404 | * __jbd2_log_space_left: Return the number of free blocks left in the journal. |
470decc6 DK |
405 | * |
406 | * Called with the journal already locked. | |
407 | * | |
408 | * Called under j_state_lock | |
409 | */ | |
410 | ||
f7f4bccb | 411 | int __jbd2_log_space_left(journal_t *journal) |
470decc6 DK |
412 | { |
413 | int left = journal->j_free; | |
414 | ||
415 | assert_spin_locked(&journal->j_state_lock); | |
416 | ||
417 | /* | |
418 | * Be pessimistic here about the number of those free blocks which | |
419 | * might be required for log descriptor control blocks. | |
420 | */ | |
421 | ||
422 | #define MIN_LOG_RESERVED_BLOCKS 32 /* Allow for rounding errors */ | |
423 | ||
424 | left -= MIN_LOG_RESERVED_BLOCKS; | |
425 | ||
426 | if (left <= 0) | |
427 | return 0; | |
428 | left -= (left >> 3); | |
429 | return left; | |
430 | } | |
431 | ||
432 | /* | |
433 | * Called under j_state_lock. Returns true if a transaction was started. | |
434 | */ | |
f7f4bccb | 435 | int __jbd2_log_start_commit(journal_t *journal, tid_t target) |
470decc6 DK |
436 | { |
437 | /* | |
438 | * Are we already doing a recent enough commit? | |
439 | */ | |
440 | if (!tid_geq(journal->j_commit_request, target)) { | |
441 | /* | |
442 | * We want a new commit: OK, mark the request and wakup the | |
443 | * commit thread. We do _not_ do the commit ourselves. | |
444 | */ | |
445 | ||
446 | journal->j_commit_request = target; | |
447 | jbd_debug(1, "JBD: requesting commit %d/%d\n", | |
448 | journal->j_commit_request, | |
449 | journal->j_commit_sequence); | |
450 | wake_up(&journal->j_wait_commit); | |
451 | return 1; | |
452 | } | |
453 | return 0; | |
454 | } | |
455 | ||
f7f4bccb | 456 | int jbd2_log_start_commit(journal_t *journal, tid_t tid) |
470decc6 DK |
457 | { |
458 | int ret; | |
459 | ||
460 | spin_lock(&journal->j_state_lock); | |
f7f4bccb | 461 | ret = __jbd2_log_start_commit(journal, tid); |
470decc6 DK |
462 | spin_unlock(&journal->j_state_lock); |
463 | return ret; | |
464 | } | |
465 | ||
466 | /* | |
467 | * Force and wait upon a commit if the calling process is not within | |
468 | * transaction. This is used for forcing out undo-protected data which contains | |
469 | * bitmaps, when the fs is running out of space. | |
470 | * | |
471 | * We can only force the running transaction if we don't have an active handle; | |
472 | * otherwise, we will deadlock. | |
473 | * | |
474 | * Returns true if a transaction was started. | |
475 | */ | |
f7f4bccb | 476 | int jbd2_journal_force_commit_nested(journal_t *journal) |
470decc6 DK |
477 | { |
478 | transaction_t *transaction = NULL; | |
479 | tid_t tid; | |
480 | ||
481 | spin_lock(&journal->j_state_lock); | |
482 | if (journal->j_running_transaction && !current->journal_info) { | |
483 | transaction = journal->j_running_transaction; | |
f7f4bccb | 484 | __jbd2_log_start_commit(journal, transaction->t_tid); |
470decc6 DK |
485 | } else if (journal->j_committing_transaction) |
486 | transaction = journal->j_committing_transaction; | |
487 | ||
488 | if (!transaction) { | |
489 | spin_unlock(&journal->j_state_lock); | |
490 | return 0; /* Nothing to retry */ | |
491 | } | |
492 | ||
493 | tid = transaction->t_tid; | |
494 | spin_unlock(&journal->j_state_lock); | |
f7f4bccb | 495 | jbd2_log_wait_commit(journal, tid); |
470decc6 DK |
496 | return 1; |
497 | } | |
498 | ||
499 | /* | |
500 | * Start a commit of the current running transaction (if any). Returns true | |
501 | * if a transaction was started, and fills its tid in at *ptid | |
502 | */ | |
f7f4bccb | 503 | int jbd2_journal_start_commit(journal_t *journal, tid_t *ptid) |
470decc6 DK |
504 | { |
505 | int ret = 0; | |
506 | ||
507 | spin_lock(&journal->j_state_lock); | |
508 | if (journal->j_running_transaction) { | |
509 | tid_t tid = journal->j_running_transaction->t_tid; | |
510 | ||
f7f4bccb | 511 | ret = __jbd2_log_start_commit(journal, tid); |
470decc6 DK |
512 | if (ret && ptid) |
513 | *ptid = tid; | |
514 | } else if (journal->j_committing_transaction && ptid) { | |
515 | /* | |
516 | * If ext3_write_super() recently started a commit, then we | |
517 | * have to wait for completion of that transaction | |
518 | */ | |
519 | *ptid = journal->j_committing_transaction->t_tid; | |
520 | ret = 1; | |
521 | } | |
522 | spin_unlock(&journal->j_state_lock); | |
523 | return ret; | |
524 | } | |
525 | ||
526 | /* | |
527 | * Wait for a specified commit to complete. | |
528 | * The caller may not hold the journal lock. | |
529 | */ | |
f7f4bccb | 530 | int jbd2_log_wait_commit(journal_t *journal, tid_t tid) |
470decc6 DK |
531 | { |
532 | int err = 0; | |
533 | ||
e23291b9 | 534 | #ifdef CONFIG_JBD2_DEBUG |
470decc6 DK |
535 | spin_lock(&journal->j_state_lock); |
536 | if (!tid_geq(journal->j_commit_request, tid)) { | |
537 | printk(KERN_EMERG | |
538 | "%s: error: j_commit_request=%d, tid=%d\n", | |
329d291f | 539 | __func__, journal->j_commit_request, tid); |
470decc6 DK |
540 | } |
541 | spin_unlock(&journal->j_state_lock); | |
542 | #endif | |
543 | spin_lock(&journal->j_state_lock); | |
544 | while (tid_gt(tid, journal->j_commit_sequence)) { | |
545 | jbd_debug(1, "JBD: want %d, j_commit_sequence=%d\n", | |
546 | tid, journal->j_commit_sequence); | |
547 | wake_up(&journal->j_wait_commit); | |
548 | spin_unlock(&journal->j_state_lock); | |
549 | wait_event(journal->j_wait_done_commit, | |
550 | !tid_gt(tid, journal->j_commit_sequence)); | |
551 | spin_lock(&journal->j_state_lock); | |
552 | } | |
553 | spin_unlock(&journal->j_state_lock); | |
554 | ||
555 | if (unlikely(is_journal_aborted(journal))) { | |
556 | printk(KERN_EMERG "journal commit I/O error\n"); | |
557 | err = -EIO; | |
558 | } | |
559 | return err; | |
560 | } | |
561 | ||
562 | /* | |
563 | * Log buffer allocation routines: | |
564 | */ | |
565 | ||
18eba7aa | 566 | int jbd2_journal_next_log_block(journal_t *journal, unsigned long long *retp) |
470decc6 DK |
567 | { |
568 | unsigned long blocknr; | |
569 | ||
570 | spin_lock(&journal->j_state_lock); | |
571 | J_ASSERT(journal->j_free > 1); | |
572 | ||
573 | blocknr = journal->j_head; | |
574 | journal->j_head++; | |
575 | journal->j_free--; | |
576 | if (journal->j_head == journal->j_last) | |
577 | journal->j_head = journal->j_first; | |
578 | spin_unlock(&journal->j_state_lock); | |
f7f4bccb | 579 | return jbd2_journal_bmap(journal, blocknr, retp); |
470decc6 DK |
580 | } |
581 | ||
582 | /* | |
583 | * Conversion of logical to physical block numbers for the journal | |
584 | * | |
585 | * On external journals the journal blocks are identity-mapped, so | |
586 | * this is a no-op. If needed, we can use j_blk_offset - everything is | |
587 | * ready. | |
588 | */ | |
f7f4bccb | 589 | int jbd2_journal_bmap(journal_t *journal, unsigned long blocknr, |
18eba7aa | 590 | unsigned long long *retp) |
470decc6 DK |
591 | { |
592 | int err = 0; | |
18eba7aa | 593 | unsigned long long ret; |
470decc6 DK |
594 | |
595 | if (journal->j_inode) { | |
596 | ret = bmap(journal->j_inode, blocknr); | |
597 | if (ret) | |
598 | *retp = ret; | |
599 | else { | |
470decc6 DK |
600 | printk(KERN_ALERT "%s: journal block not found " |
601 | "at offset %lu on %s\n", | |
05496769 | 602 | __func__, blocknr, journal->j_devname); |
470decc6 DK |
603 | err = -EIO; |
604 | __journal_abort_soft(journal, err); | |
605 | } | |
606 | } else { | |
607 | *retp = blocknr; /* +journal->j_blk_offset */ | |
608 | } | |
609 | return err; | |
610 | } | |
611 | ||
612 | /* | |
613 | * We play buffer_head aliasing tricks to write data/metadata blocks to | |
614 | * the journal without copying their contents, but for journal | |
615 | * descriptor blocks we do need to generate bona fide buffers. | |
616 | * | |
f7f4bccb | 617 | * After the caller of jbd2_journal_get_descriptor_buffer() has finished modifying |
470decc6 DK |
618 | * the buffer's contents they really should run flush_dcache_page(bh->b_page). |
619 | * But we don't bother doing that, so there will be coherency problems with | |
620 | * mmaps of blockdevs which hold live JBD-controlled filesystems. | |
621 | */ | |
f7f4bccb | 622 | struct journal_head *jbd2_journal_get_descriptor_buffer(journal_t *journal) |
470decc6 DK |
623 | { |
624 | struct buffer_head *bh; | |
18eba7aa | 625 | unsigned long long blocknr; |
470decc6 DK |
626 | int err; |
627 | ||
f7f4bccb | 628 | err = jbd2_journal_next_log_block(journal, &blocknr); |
470decc6 DK |
629 | |
630 | if (err) | |
631 | return NULL; | |
632 | ||
633 | bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); | |
634 | lock_buffer(bh); | |
635 | memset(bh->b_data, 0, journal->j_blocksize); | |
636 | set_buffer_uptodate(bh); | |
637 | unlock_buffer(bh); | |
638 | BUFFER_TRACE(bh, "return this buffer"); | |
f7f4bccb | 639 | return jbd2_journal_add_journal_head(bh); |
470decc6 DK |
640 | } |
641 | ||
8e85fb3f JL |
642 | struct jbd2_stats_proc_session { |
643 | journal_t *journal; | |
644 | struct transaction_stats_s *stats; | |
645 | int start; | |
646 | int max; | |
647 | }; | |
648 | ||
649 | static void *jbd2_history_skip_empty(struct jbd2_stats_proc_session *s, | |
650 | struct transaction_stats_s *ts, | |
651 | int first) | |
652 | { | |
653 | if (ts == s->stats + s->max) | |
654 | ts = s->stats; | |
655 | if (!first && ts == s->stats + s->start) | |
656 | return NULL; | |
657 | while (ts->ts_type == 0) { | |
658 | ts++; | |
659 | if (ts == s->stats + s->max) | |
660 | ts = s->stats; | |
661 | if (ts == s->stats + s->start) | |
662 | return NULL; | |
663 | } | |
664 | return ts; | |
665 | ||
666 | } | |
667 | ||
668 | static void *jbd2_seq_history_start(struct seq_file *seq, loff_t *pos) | |
669 | { | |
670 | struct jbd2_stats_proc_session *s = seq->private; | |
671 | struct transaction_stats_s *ts; | |
672 | int l = *pos; | |
673 | ||
674 | if (l == 0) | |
675 | return SEQ_START_TOKEN; | |
676 | ts = jbd2_history_skip_empty(s, s->stats + s->start, 1); | |
677 | if (!ts) | |
678 | return NULL; | |
679 | l--; | |
680 | while (l) { | |
681 | ts = jbd2_history_skip_empty(s, ++ts, 0); | |
682 | if (!ts) | |
683 | break; | |
684 | l--; | |
685 | } | |
686 | return ts; | |
687 | } | |
688 | ||
689 | static void *jbd2_seq_history_next(struct seq_file *seq, void *v, loff_t *pos) | |
690 | { | |
691 | struct jbd2_stats_proc_session *s = seq->private; | |
692 | struct transaction_stats_s *ts = v; | |
693 | ||
694 | ++*pos; | |
695 | if (v == SEQ_START_TOKEN) | |
696 | return jbd2_history_skip_empty(s, s->stats + s->start, 1); | |
697 | else | |
698 | return jbd2_history_skip_empty(s, ++ts, 0); | |
699 | } | |
700 | ||
701 | static int jbd2_seq_history_show(struct seq_file *seq, void *v) | |
702 | { | |
703 | struct transaction_stats_s *ts = v; | |
704 | if (v == SEQ_START_TOKEN) { | |
705 | seq_printf(seq, "%-4s %-5s %-5s %-5s %-5s %-5s %-5s %-6s %-5s " | |
706 | "%-5s %-5s %-5s %-5s %-5s\n", "R/C", "tid", | |
707 | "wait", "run", "lock", "flush", "log", "hndls", | |
708 | "block", "inlog", "ctime", "write", "drop", | |
709 | "close"); | |
710 | return 0; | |
711 | } | |
712 | if (ts->ts_type == JBD2_STATS_RUN) | |
713 | seq_printf(seq, "%-4s %-5lu %-5u %-5u %-5u %-5u %-5u " | |
714 | "%-6lu %-5lu %-5lu\n", "R", ts->ts_tid, | |
715 | jiffies_to_msecs(ts->u.run.rs_wait), | |
716 | jiffies_to_msecs(ts->u.run.rs_running), | |
717 | jiffies_to_msecs(ts->u.run.rs_locked), | |
718 | jiffies_to_msecs(ts->u.run.rs_flushing), | |
719 | jiffies_to_msecs(ts->u.run.rs_logging), | |
720 | ts->u.run.rs_handle_count, | |
721 | ts->u.run.rs_blocks, | |
722 | ts->u.run.rs_blocks_logged); | |
723 | else if (ts->ts_type == JBD2_STATS_CHECKPOINT) | |
724 | seq_printf(seq, "%-4s %-5lu %48s %-5u %-5lu %-5lu %-5lu\n", | |
725 | "C", ts->ts_tid, " ", | |
726 | jiffies_to_msecs(ts->u.chp.cs_chp_time), | |
727 | ts->u.chp.cs_written, ts->u.chp.cs_dropped, | |
728 | ts->u.chp.cs_forced_to_close); | |
729 | else | |
730 | J_ASSERT(0); | |
731 | return 0; | |
732 | } | |
733 | ||
734 | static void jbd2_seq_history_stop(struct seq_file *seq, void *v) | |
735 | { | |
736 | } | |
737 | ||
738 | static struct seq_operations jbd2_seq_history_ops = { | |
739 | .start = jbd2_seq_history_start, | |
740 | .next = jbd2_seq_history_next, | |
741 | .stop = jbd2_seq_history_stop, | |
742 | .show = jbd2_seq_history_show, | |
743 | }; | |
744 | ||
745 | static int jbd2_seq_history_open(struct inode *inode, struct file *file) | |
746 | { | |
747 | journal_t *journal = PDE(inode)->data; | |
748 | struct jbd2_stats_proc_session *s; | |
749 | int rc, size; | |
750 | ||
751 | s = kmalloc(sizeof(*s), GFP_KERNEL); | |
752 | if (s == NULL) | |
753 | return -ENOMEM; | |
754 | size = sizeof(struct transaction_stats_s) * journal->j_history_max; | |
755 | s->stats = kmalloc(size, GFP_KERNEL); | |
756 | if (s->stats == NULL) { | |
757 | kfree(s); | |
758 | return -ENOMEM; | |
759 | } | |
760 | spin_lock(&journal->j_history_lock); | |
761 | memcpy(s->stats, journal->j_history, size); | |
762 | s->max = journal->j_history_max; | |
763 | s->start = journal->j_history_cur % s->max; | |
764 | spin_unlock(&journal->j_history_lock); | |
765 | ||
766 | rc = seq_open(file, &jbd2_seq_history_ops); | |
767 | if (rc == 0) { | |
768 | struct seq_file *m = file->private_data; | |
769 | m->private = s; | |
770 | } else { | |
771 | kfree(s->stats); | |
772 | kfree(s); | |
773 | } | |
774 | return rc; | |
775 | ||
776 | } | |
777 | ||
778 | static int jbd2_seq_history_release(struct inode *inode, struct file *file) | |
779 | { | |
780 | struct seq_file *seq = file->private_data; | |
781 | struct jbd2_stats_proc_session *s = seq->private; | |
782 | ||
783 | kfree(s->stats); | |
784 | kfree(s); | |
785 | return seq_release(inode, file); | |
786 | } | |
787 | ||
788 | static struct file_operations jbd2_seq_history_fops = { | |
789 | .owner = THIS_MODULE, | |
790 | .open = jbd2_seq_history_open, | |
791 | .read = seq_read, | |
792 | .llseek = seq_lseek, | |
793 | .release = jbd2_seq_history_release, | |
794 | }; | |
795 | ||
796 | static void *jbd2_seq_info_start(struct seq_file *seq, loff_t *pos) | |
797 | { | |
798 | return *pos ? NULL : SEQ_START_TOKEN; | |
799 | } | |
800 | ||
801 | static void *jbd2_seq_info_next(struct seq_file *seq, void *v, loff_t *pos) | |
802 | { | |
803 | return NULL; | |
804 | } | |
805 | ||
806 | static int jbd2_seq_info_show(struct seq_file *seq, void *v) | |
807 | { | |
808 | struct jbd2_stats_proc_session *s = seq->private; | |
809 | ||
810 | if (v != SEQ_START_TOKEN) | |
811 | return 0; | |
812 | seq_printf(seq, "%lu transaction, each upto %u blocks\n", | |
813 | s->stats->ts_tid, | |
814 | s->journal->j_max_transaction_buffers); | |
815 | if (s->stats->ts_tid == 0) | |
816 | return 0; | |
817 | seq_printf(seq, "average: \n %ums waiting for transaction\n", | |
818 | jiffies_to_msecs(s->stats->u.run.rs_wait / s->stats->ts_tid)); | |
819 | seq_printf(seq, " %ums running transaction\n", | |
820 | jiffies_to_msecs(s->stats->u.run.rs_running / s->stats->ts_tid)); | |
821 | seq_printf(seq, " %ums transaction was being locked\n", | |
822 | jiffies_to_msecs(s->stats->u.run.rs_locked / s->stats->ts_tid)); | |
823 | seq_printf(seq, " %ums flushing data (in ordered mode)\n", | |
824 | jiffies_to_msecs(s->stats->u.run.rs_flushing / s->stats->ts_tid)); | |
825 | seq_printf(seq, " %ums logging transaction\n", | |
826 | jiffies_to_msecs(s->stats->u.run.rs_logging / s->stats->ts_tid)); | |
827 | seq_printf(seq, " %lu handles per transaction\n", | |
828 | s->stats->u.run.rs_handle_count / s->stats->ts_tid); | |
829 | seq_printf(seq, " %lu blocks per transaction\n", | |
830 | s->stats->u.run.rs_blocks / s->stats->ts_tid); | |
831 | seq_printf(seq, " %lu logged blocks per transaction\n", | |
832 | s->stats->u.run.rs_blocks_logged / s->stats->ts_tid); | |
833 | return 0; | |
834 | } | |
835 | ||
836 | static void jbd2_seq_info_stop(struct seq_file *seq, void *v) | |
837 | { | |
838 | } | |
839 | ||
840 | static struct seq_operations jbd2_seq_info_ops = { | |
841 | .start = jbd2_seq_info_start, | |
842 | .next = jbd2_seq_info_next, | |
843 | .stop = jbd2_seq_info_stop, | |
844 | .show = jbd2_seq_info_show, | |
845 | }; | |
846 | ||
847 | static int jbd2_seq_info_open(struct inode *inode, struct file *file) | |
848 | { | |
849 | journal_t *journal = PDE(inode)->data; | |
850 | struct jbd2_stats_proc_session *s; | |
851 | int rc, size; | |
852 | ||
853 | s = kmalloc(sizeof(*s), GFP_KERNEL); | |
854 | if (s == NULL) | |
855 | return -ENOMEM; | |
856 | size = sizeof(struct transaction_stats_s); | |
857 | s->stats = kmalloc(size, GFP_KERNEL); | |
858 | if (s->stats == NULL) { | |
859 | kfree(s); | |
860 | return -ENOMEM; | |
861 | } | |
862 | spin_lock(&journal->j_history_lock); | |
863 | memcpy(s->stats, &journal->j_stats, size); | |
864 | s->journal = journal; | |
865 | spin_unlock(&journal->j_history_lock); | |
866 | ||
867 | rc = seq_open(file, &jbd2_seq_info_ops); | |
868 | if (rc == 0) { | |
869 | struct seq_file *m = file->private_data; | |
870 | m->private = s; | |
871 | } else { | |
872 | kfree(s->stats); | |
873 | kfree(s); | |
874 | } | |
875 | return rc; | |
876 | ||
877 | } | |
878 | ||
879 | static int jbd2_seq_info_release(struct inode *inode, struct file *file) | |
880 | { | |
881 | struct seq_file *seq = file->private_data; | |
882 | struct jbd2_stats_proc_session *s = seq->private; | |
883 | kfree(s->stats); | |
884 | kfree(s); | |
885 | return seq_release(inode, file); | |
886 | } | |
887 | ||
888 | static struct file_operations jbd2_seq_info_fops = { | |
889 | .owner = THIS_MODULE, | |
890 | .open = jbd2_seq_info_open, | |
891 | .read = seq_read, | |
892 | .llseek = seq_lseek, | |
893 | .release = jbd2_seq_info_release, | |
894 | }; | |
895 | ||
896 | static struct proc_dir_entry *proc_jbd2_stats; | |
897 | ||
898 | static void jbd2_stats_proc_init(journal_t *journal) | |
899 | { | |
05496769 | 900 | journal->j_proc_entry = proc_mkdir(journal->j_devname, proc_jbd2_stats); |
8e85fb3f | 901 | if (journal->j_proc_entry) { |
79da3664 DL |
902 | proc_create_data("history", S_IRUGO, journal->j_proc_entry, |
903 | &jbd2_seq_history_fops, journal); | |
904 | proc_create_data("info", S_IRUGO, journal->j_proc_entry, | |
905 | &jbd2_seq_info_fops, journal); | |
8e85fb3f JL |
906 | } |
907 | } | |
908 | ||
909 | static void jbd2_stats_proc_exit(journal_t *journal) | |
910 | { | |
8e85fb3f JL |
911 | remove_proc_entry("info", journal->j_proc_entry); |
912 | remove_proc_entry("history", journal->j_proc_entry); | |
05496769 | 913 | remove_proc_entry(journal->j_devname, proc_jbd2_stats); |
8e85fb3f JL |
914 | } |
915 | ||
916 | static void journal_init_stats(journal_t *journal) | |
917 | { | |
918 | int size; | |
919 | ||
920 | if (!proc_jbd2_stats) | |
921 | return; | |
922 | ||
923 | journal->j_history_max = 100; | |
924 | size = sizeof(struct transaction_stats_s) * journal->j_history_max; | |
925 | journal->j_history = kzalloc(size, GFP_KERNEL); | |
926 | if (!journal->j_history) { | |
927 | journal->j_history_max = 0; | |
928 | return; | |
929 | } | |
930 | spin_lock_init(&journal->j_history_lock); | |
931 | } | |
932 | ||
470decc6 DK |
933 | /* |
934 | * Management for journal control blocks: functions to create and | |
935 | * destroy journal_t structures, and to initialise and read existing | |
936 | * journal blocks from disk. */ | |
937 | ||
938 | /* First: create and setup a journal_t object in memory. We initialise | |
939 | * very few fields yet: that has to wait until we have created the | |
940 | * journal structures from from scratch, or loaded them from disk. */ | |
941 | ||
942 | static journal_t * journal_init_common (void) | |
943 | { | |
944 | journal_t *journal; | |
945 | int err; | |
946 | ||
d802ffa8 | 947 | journal = kzalloc(sizeof(*journal), GFP_KERNEL|__GFP_NOFAIL); |
470decc6 DK |
948 | if (!journal) |
949 | goto fail; | |
470decc6 DK |
950 | |
951 | init_waitqueue_head(&journal->j_wait_transaction_locked); | |
952 | init_waitqueue_head(&journal->j_wait_logspace); | |
953 | init_waitqueue_head(&journal->j_wait_done_commit); | |
954 | init_waitqueue_head(&journal->j_wait_checkpoint); | |
955 | init_waitqueue_head(&journal->j_wait_commit); | |
956 | init_waitqueue_head(&journal->j_wait_updates); | |
957 | mutex_init(&journal->j_barrier); | |
958 | mutex_init(&journal->j_checkpoint_mutex); | |
959 | spin_lock_init(&journal->j_revoke_lock); | |
960 | spin_lock_init(&journal->j_list_lock); | |
961 | spin_lock_init(&journal->j_state_lock); | |
962 | ||
cd02ff0b | 963 | journal->j_commit_interval = (HZ * JBD2_DEFAULT_MAX_COMMIT_AGE); |
470decc6 DK |
964 | |
965 | /* The journal is marked for error until we succeed with recovery! */ | |
f7f4bccb | 966 | journal->j_flags = JBD2_ABORT; |
470decc6 DK |
967 | |
968 | /* Set up a default-sized revoke table for the new mount. */ | |
f7f4bccb | 969 | err = jbd2_journal_init_revoke(journal, JOURNAL_REVOKE_DEFAULT_HASH); |
470decc6 DK |
970 | if (err) { |
971 | kfree(journal); | |
972 | goto fail; | |
973 | } | |
8e85fb3f JL |
974 | |
975 | journal_init_stats(journal); | |
976 | ||
470decc6 DK |
977 | return journal; |
978 | fail: | |
979 | return NULL; | |
980 | } | |
981 | ||
f7f4bccb | 982 | /* jbd2_journal_init_dev and jbd2_journal_init_inode: |
470decc6 DK |
983 | * |
984 | * Create a journal structure assigned some fixed set of disk blocks to | |
985 | * the journal. We don't actually touch those disk blocks yet, but we | |
986 | * need to set up all of the mapping information to tell the journaling | |
987 | * system where the journal blocks are. | |
988 | * | |
989 | */ | |
990 | ||
991 | /** | |
5648ba5b | 992 | * journal_t * jbd2_journal_init_dev() - creates and initialises a journal structure |
470decc6 DK |
993 | * @bdev: Block device on which to create the journal |
994 | * @fs_dev: Device which hold journalled filesystem for this journal. | |
995 | * @start: Block nr Start of journal. | |
996 | * @len: Length of the journal in blocks. | |
997 | * @blocksize: blocksize of journalling device | |
5648ba5b RD |
998 | * |
999 | * Returns: a newly created journal_t * | |
470decc6 | 1000 | * |
f7f4bccb | 1001 | * jbd2_journal_init_dev creates a journal which maps a fixed contiguous |
470decc6 DK |
1002 | * range of blocks on an arbitrary block device. |
1003 | * | |
1004 | */ | |
f7f4bccb | 1005 | journal_t * jbd2_journal_init_dev(struct block_device *bdev, |
470decc6 | 1006 | struct block_device *fs_dev, |
18eba7aa | 1007 | unsigned long long start, int len, int blocksize) |
470decc6 DK |
1008 | { |
1009 | journal_t *journal = journal_init_common(); | |
1010 | struct buffer_head *bh; | |
05496769 | 1011 | char *p; |
470decc6 DK |
1012 | int n; |
1013 | ||
1014 | if (!journal) | |
1015 | return NULL; | |
1016 | ||
1017 | /* journal descriptor can store up to n blocks -bzzz */ | |
1018 | journal->j_blocksize = blocksize; | |
1019 | n = journal->j_blocksize / sizeof(journal_block_tag_t); | |
1020 | journal->j_wbufsize = n; | |
1021 | journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL); | |
1022 | if (!journal->j_wbuf) { | |
1023 | printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n", | |
329d291f | 1024 | __func__); |
470decc6 DK |
1025 | kfree(journal); |
1026 | journal = NULL; | |
5eb30790 | 1027 | goto out; |
470decc6 DK |
1028 | } |
1029 | journal->j_dev = bdev; | |
1030 | journal->j_fs_dev = fs_dev; | |
1031 | journal->j_blk_offset = start; | |
1032 | journal->j_maxlen = len; | |
05496769 TT |
1033 | bdevname(journal->j_dev, journal->j_devname); |
1034 | p = journal->j_devname; | |
1035 | while ((p = strchr(p, '/'))) | |
1036 | *p = '!'; | |
8e85fb3f | 1037 | jbd2_stats_proc_init(journal); |
470decc6 DK |
1038 | |
1039 | bh = __getblk(journal->j_dev, start, journal->j_blocksize); | |
1040 | J_ASSERT(bh != NULL); | |
1041 | journal->j_sb_buffer = bh; | |
1042 | journal->j_superblock = (journal_superblock_t *)bh->b_data; | |
5eb30790 | 1043 | out: |
470decc6 DK |
1044 | return journal; |
1045 | } | |
1046 | ||
1047 | /** | |
f7f4bccb | 1048 | * journal_t * jbd2_journal_init_inode () - creates a journal which maps to a inode. |
470decc6 DK |
1049 | * @inode: An inode to create the journal in |
1050 | * | |
f7f4bccb | 1051 | * jbd2_journal_init_inode creates a journal which maps an on-disk inode as |
470decc6 DK |
1052 | * the journal. The inode must exist already, must support bmap() and |
1053 | * must have all data blocks preallocated. | |
1054 | */ | |
f7f4bccb | 1055 | journal_t * jbd2_journal_init_inode (struct inode *inode) |
470decc6 DK |
1056 | { |
1057 | struct buffer_head *bh; | |
1058 | journal_t *journal = journal_init_common(); | |
05496769 | 1059 | char *p; |
470decc6 DK |
1060 | int err; |
1061 | int n; | |
18eba7aa | 1062 | unsigned long long blocknr; |
470decc6 DK |
1063 | |
1064 | if (!journal) | |
1065 | return NULL; | |
1066 | ||
1067 | journal->j_dev = journal->j_fs_dev = inode->i_sb->s_bdev; | |
1068 | journal->j_inode = inode; | |
05496769 TT |
1069 | bdevname(journal->j_dev, journal->j_devname); |
1070 | p = journal->j_devname; | |
1071 | while ((p = strchr(p, '/'))) | |
1072 | *p = '!'; | |
1073 | p = journal->j_devname + strlen(journal->j_devname); | |
1074 | sprintf(p, ":%lu", journal->j_inode->i_ino); | |
470decc6 DK |
1075 | jbd_debug(1, |
1076 | "journal %p: inode %s/%ld, size %Ld, bits %d, blksize %ld\n", | |
1077 | journal, inode->i_sb->s_id, inode->i_ino, | |
1078 | (long long) inode->i_size, | |
1079 | inode->i_sb->s_blocksize_bits, inode->i_sb->s_blocksize); | |
1080 | ||
1081 | journal->j_maxlen = inode->i_size >> inode->i_sb->s_blocksize_bits; | |
1082 | journal->j_blocksize = inode->i_sb->s_blocksize; | |
8e85fb3f | 1083 | jbd2_stats_proc_init(journal); |
470decc6 DK |
1084 | |
1085 | /* journal descriptor can store up to n blocks -bzzz */ | |
1086 | n = journal->j_blocksize / sizeof(journal_block_tag_t); | |
1087 | journal->j_wbufsize = n; | |
1088 | journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL); | |
1089 | if (!journal->j_wbuf) { | |
1090 | printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n", | |
329d291f | 1091 | __func__); |
470decc6 DK |
1092 | kfree(journal); |
1093 | return NULL; | |
1094 | } | |
1095 | ||
f7f4bccb | 1096 | err = jbd2_journal_bmap(journal, 0, &blocknr); |
470decc6 DK |
1097 | /* If that failed, give up */ |
1098 | if (err) { | |
1099 | printk(KERN_ERR "%s: Cannnot locate journal superblock\n", | |
329d291f | 1100 | __func__); |
470decc6 DK |
1101 | kfree(journal); |
1102 | return NULL; | |
1103 | } | |
1104 | ||
1105 | bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); | |
1106 | J_ASSERT(bh != NULL); | |
1107 | journal->j_sb_buffer = bh; | |
1108 | journal->j_superblock = (journal_superblock_t *)bh->b_data; | |
1109 | ||
1110 | return journal; | |
1111 | } | |
1112 | ||
1113 | /* | |
1114 | * If the journal init or create aborts, we need to mark the journal | |
1115 | * superblock as being NULL to prevent the journal destroy from writing | |
1116 | * back a bogus superblock. | |
1117 | */ | |
1118 | static void journal_fail_superblock (journal_t *journal) | |
1119 | { | |
1120 | struct buffer_head *bh = journal->j_sb_buffer; | |
1121 | brelse(bh); | |
1122 | journal->j_sb_buffer = NULL; | |
1123 | } | |
1124 | ||
1125 | /* | |
1126 | * Given a journal_t structure, initialise the various fields for | |
1127 | * startup of a new journaling session. We use this both when creating | |
1128 | * a journal, and after recovering an old journal to reset it for | |
1129 | * subsequent use. | |
1130 | */ | |
1131 | ||
1132 | static int journal_reset(journal_t *journal) | |
1133 | { | |
1134 | journal_superblock_t *sb = journal->j_superblock; | |
18eba7aa | 1135 | unsigned long long first, last; |
470decc6 DK |
1136 | |
1137 | first = be32_to_cpu(sb->s_first); | |
1138 | last = be32_to_cpu(sb->s_maxlen); | |
1139 | ||
1140 | journal->j_first = first; | |
1141 | journal->j_last = last; | |
1142 | ||
1143 | journal->j_head = first; | |
1144 | journal->j_tail = first; | |
1145 | journal->j_free = last - first; | |
1146 | ||
1147 | journal->j_tail_sequence = journal->j_transaction_sequence; | |
1148 | journal->j_commit_sequence = journal->j_transaction_sequence - 1; | |
1149 | journal->j_commit_request = journal->j_commit_sequence; | |
1150 | ||
1151 | journal->j_max_transaction_buffers = journal->j_maxlen / 4; | |
1152 | ||
1153 | /* Add the dynamic fields and write it to disk. */ | |
f7f4bccb | 1154 | jbd2_journal_update_superblock(journal, 1); |
97f06784 | 1155 | return jbd2_journal_start_thread(journal); |
470decc6 DK |
1156 | } |
1157 | ||
1158 | /** | |
f7f4bccb | 1159 | * int jbd2_journal_create() - Initialise the new journal file |
470decc6 DK |
1160 | * @journal: Journal to create. This structure must have been initialised |
1161 | * | |
1162 | * Given a journal_t structure which tells us which disk blocks we can | |
1163 | * use, create a new journal superblock and initialise all of the | |
1164 | * journal fields from scratch. | |
1165 | **/ | |
f7f4bccb | 1166 | int jbd2_journal_create(journal_t *journal) |
470decc6 | 1167 | { |
18eba7aa | 1168 | unsigned long long blocknr; |
470decc6 DK |
1169 | struct buffer_head *bh; |
1170 | journal_superblock_t *sb; | |
1171 | int i, err; | |
1172 | ||
f7f4bccb | 1173 | if (journal->j_maxlen < JBD2_MIN_JOURNAL_BLOCKS) { |
470decc6 DK |
1174 | printk (KERN_ERR "Journal length (%d blocks) too short.\n", |
1175 | journal->j_maxlen); | |
1176 | journal_fail_superblock(journal); | |
1177 | return -EINVAL; | |
1178 | } | |
1179 | ||
1180 | if (journal->j_inode == NULL) { | |
1181 | /* | |
1182 | * We don't know what block to start at! | |
1183 | */ | |
1184 | printk(KERN_EMERG | |
1185 | "%s: creation of journal on external device!\n", | |
329d291f | 1186 | __func__); |
470decc6 DK |
1187 | BUG(); |
1188 | } | |
1189 | ||
1190 | /* Zero out the entire journal on disk. We cannot afford to | |
f7f4bccb | 1191 | have any blocks on disk beginning with JBD2_MAGIC_NUMBER. */ |
470decc6 DK |
1192 | jbd_debug(1, "JBD: Zeroing out journal blocks...\n"); |
1193 | for (i = 0; i < journal->j_maxlen; i++) { | |
f7f4bccb | 1194 | err = jbd2_journal_bmap(journal, i, &blocknr); |
470decc6 DK |
1195 | if (err) |
1196 | return err; | |
1197 | bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); | |
1198 | lock_buffer(bh); | |
1199 | memset (bh->b_data, 0, journal->j_blocksize); | |
1200 | BUFFER_TRACE(bh, "marking dirty"); | |
1201 | mark_buffer_dirty(bh); | |
1202 | BUFFER_TRACE(bh, "marking uptodate"); | |
1203 | set_buffer_uptodate(bh); | |
1204 | unlock_buffer(bh); | |
1205 | __brelse(bh); | |
1206 | } | |
1207 | ||
1208 | sync_blockdev(journal->j_dev); | |
1209 | jbd_debug(1, "JBD: journal cleared.\n"); | |
1210 | ||
1211 | /* OK, fill in the initial static fields in the new superblock */ | |
1212 | sb = journal->j_superblock; | |
1213 | ||
f7f4bccb MC |
1214 | sb->s_header.h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER); |
1215 | sb->s_header.h_blocktype = cpu_to_be32(JBD2_SUPERBLOCK_V2); | |
470decc6 DK |
1216 | |
1217 | sb->s_blocksize = cpu_to_be32(journal->j_blocksize); | |
1218 | sb->s_maxlen = cpu_to_be32(journal->j_maxlen); | |
1219 | sb->s_first = cpu_to_be32(1); | |
1220 | ||
1221 | journal->j_transaction_sequence = 1; | |
1222 | ||
f7f4bccb | 1223 | journal->j_flags &= ~JBD2_ABORT; |
470decc6 DK |
1224 | journal->j_format_version = 2; |
1225 | ||
1226 | return journal_reset(journal); | |
1227 | } | |
1228 | ||
1229 | /** | |
f7f4bccb | 1230 | * void jbd2_journal_update_superblock() - Update journal sb on disk. |
470decc6 DK |
1231 | * @journal: The journal to update. |
1232 | * @wait: Set to '0' if you don't want to wait for IO completion. | |
1233 | * | |
1234 | * Update a journal's dynamic superblock fields and write it to disk, | |
1235 | * optionally waiting for the IO to complete. | |
1236 | */ | |
f7f4bccb | 1237 | void jbd2_journal_update_superblock(journal_t *journal, int wait) |
470decc6 DK |
1238 | { |
1239 | journal_superblock_t *sb = journal->j_superblock; | |
1240 | struct buffer_head *bh = journal->j_sb_buffer; | |
1241 | ||
1242 | /* | |
1243 | * As a special case, if the on-disk copy is already marked as needing | |
1244 | * no recovery (s_start == 0) and there are no outstanding transactions | |
1245 | * in the filesystem, then we can safely defer the superblock update | |
f7f4bccb | 1246 | * until the next commit by setting JBD2_FLUSHED. This avoids |
470decc6 DK |
1247 | * attempting a write to a potential-readonly device. |
1248 | */ | |
1249 | if (sb->s_start == 0 && journal->j_tail_sequence == | |
1250 | journal->j_transaction_sequence) { | |
1251 | jbd_debug(1,"JBD: Skipping superblock update on recovered sb " | |
1252 | "(start %ld, seq %d, errno %d)\n", | |
1253 | journal->j_tail, journal->j_tail_sequence, | |
1254 | journal->j_errno); | |
1255 | goto out; | |
1256 | } | |
1257 | ||
914258bf TT |
1258 | if (buffer_write_io_error(bh)) { |
1259 | /* | |
1260 | * Oh, dear. A previous attempt to write the journal | |
1261 | * superblock failed. This could happen because the | |
1262 | * USB device was yanked out. Or it could happen to | |
1263 | * be a transient write error and maybe the block will | |
1264 | * be remapped. Nothing we can do but to retry the | |
1265 | * write and hope for the best. | |
1266 | */ | |
1267 | printk(KERN_ERR "JBD2: previous I/O error detected " | |
1268 | "for journal superblock update for %s.\n", | |
1269 | journal->j_devname); | |
1270 | clear_buffer_write_io_error(bh); | |
1271 | set_buffer_uptodate(bh); | |
1272 | } | |
1273 | ||
470decc6 DK |
1274 | spin_lock(&journal->j_state_lock); |
1275 | jbd_debug(1,"JBD: updating superblock (start %ld, seq %d, errno %d)\n", | |
1276 | journal->j_tail, journal->j_tail_sequence, journal->j_errno); | |
1277 | ||
1278 | sb->s_sequence = cpu_to_be32(journal->j_tail_sequence); | |
1279 | sb->s_start = cpu_to_be32(journal->j_tail); | |
1280 | sb->s_errno = cpu_to_be32(journal->j_errno); | |
1281 | spin_unlock(&journal->j_state_lock); | |
1282 | ||
1283 | BUFFER_TRACE(bh, "marking dirty"); | |
1284 | mark_buffer_dirty(bh); | |
914258bf | 1285 | if (wait) { |
470decc6 | 1286 | sync_dirty_buffer(bh); |
914258bf TT |
1287 | if (buffer_write_io_error(bh)) { |
1288 | printk(KERN_ERR "JBD2: I/O error detected " | |
1289 | "when updating journal superblock for %s.\n", | |
1290 | journal->j_devname); | |
1291 | clear_buffer_write_io_error(bh); | |
1292 | set_buffer_uptodate(bh); | |
1293 | } | |
1294 | } else | |
470decc6 DK |
1295 | ll_rw_block(SWRITE, 1, &bh); |
1296 | ||
1297 | out: | |
1298 | /* If we have just flushed the log (by marking s_start==0), then | |
1299 | * any future commit will have to be careful to update the | |
1300 | * superblock again to re-record the true start of the log. */ | |
1301 | ||
1302 | spin_lock(&journal->j_state_lock); | |
1303 | if (sb->s_start) | |
f7f4bccb | 1304 | journal->j_flags &= ~JBD2_FLUSHED; |
470decc6 | 1305 | else |
f7f4bccb | 1306 | journal->j_flags |= JBD2_FLUSHED; |
470decc6 DK |
1307 | spin_unlock(&journal->j_state_lock); |
1308 | } | |
1309 | ||
1310 | /* | |
1311 | * Read the superblock for a given journal, performing initial | |
1312 | * validation of the format. | |
1313 | */ | |
1314 | ||
1315 | static int journal_get_superblock(journal_t *journal) | |
1316 | { | |
1317 | struct buffer_head *bh; | |
1318 | journal_superblock_t *sb; | |
1319 | int err = -EIO; | |
1320 | ||
1321 | bh = journal->j_sb_buffer; | |
1322 | ||
1323 | J_ASSERT(bh != NULL); | |
1324 | if (!buffer_uptodate(bh)) { | |
1325 | ll_rw_block(READ, 1, &bh); | |
1326 | wait_on_buffer(bh); | |
1327 | if (!buffer_uptodate(bh)) { | |
1328 | printk (KERN_ERR | |
1329 | "JBD: IO error reading journal superblock\n"); | |
1330 | goto out; | |
1331 | } | |
1332 | } | |
1333 | ||
1334 | sb = journal->j_superblock; | |
1335 | ||
1336 | err = -EINVAL; | |
1337 | ||
f7f4bccb | 1338 | if (sb->s_header.h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER) || |
470decc6 DK |
1339 | sb->s_blocksize != cpu_to_be32(journal->j_blocksize)) { |
1340 | printk(KERN_WARNING "JBD: no valid journal superblock found\n"); | |
1341 | goto out; | |
1342 | } | |
1343 | ||
1344 | switch(be32_to_cpu(sb->s_header.h_blocktype)) { | |
f7f4bccb | 1345 | case JBD2_SUPERBLOCK_V1: |
470decc6 DK |
1346 | journal->j_format_version = 1; |
1347 | break; | |
f7f4bccb | 1348 | case JBD2_SUPERBLOCK_V2: |
470decc6 DK |
1349 | journal->j_format_version = 2; |
1350 | break; | |
1351 | default: | |
1352 | printk(KERN_WARNING "JBD: unrecognised superblock format ID\n"); | |
1353 | goto out; | |
1354 | } | |
1355 | ||
1356 | if (be32_to_cpu(sb->s_maxlen) < journal->j_maxlen) | |
1357 | journal->j_maxlen = be32_to_cpu(sb->s_maxlen); | |
1358 | else if (be32_to_cpu(sb->s_maxlen) > journal->j_maxlen) { | |
1359 | printk (KERN_WARNING "JBD: journal file too short\n"); | |
1360 | goto out; | |
1361 | } | |
1362 | ||
1363 | return 0; | |
1364 | ||
1365 | out: | |
1366 | journal_fail_superblock(journal); | |
1367 | return err; | |
1368 | } | |
1369 | ||
1370 | /* | |
1371 | * Load the on-disk journal superblock and read the key fields into the | |
1372 | * journal_t. | |
1373 | */ | |
1374 | ||
1375 | static int load_superblock(journal_t *journal) | |
1376 | { | |
1377 | int err; | |
1378 | journal_superblock_t *sb; | |
1379 | ||
1380 | err = journal_get_superblock(journal); | |
1381 | if (err) | |
1382 | return err; | |
1383 | ||
1384 | sb = journal->j_superblock; | |
1385 | ||
1386 | journal->j_tail_sequence = be32_to_cpu(sb->s_sequence); | |
1387 | journal->j_tail = be32_to_cpu(sb->s_start); | |
1388 | journal->j_first = be32_to_cpu(sb->s_first); | |
1389 | journal->j_last = be32_to_cpu(sb->s_maxlen); | |
1390 | journal->j_errno = be32_to_cpu(sb->s_errno); | |
1391 | ||
1392 | return 0; | |
1393 | } | |
1394 | ||
1395 | ||
1396 | /** | |
f7f4bccb | 1397 | * int jbd2_journal_load() - Read journal from disk. |
470decc6 DK |
1398 | * @journal: Journal to act on. |
1399 | * | |
1400 | * Given a journal_t structure which tells us which disk blocks contain | |
1401 | * a journal, read the journal from disk to initialise the in-memory | |
1402 | * structures. | |
1403 | */ | |
f7f4bccb | 1404 | int jbd2_journal_load(journal_t *journal) |
470decc6 DK |
1405 | { |
1406 | int err; | |
1407 | journal_superblock_t *sb; | |
1408 | ||
1409 | err = load_superblock(journal); | |
1410 | if (err) | |
1411 | return err; | |
1412 | ||
1413 | sb = journal->j_superblock; | |
1414 | /* If this is a V2 superblock, then we have to check the | |
1415 | * features flags on it. */ | |
1416 | ||
1417 | if (journal->j_format_version >= 2) { | |
1418 | if ((sb->s_feature_ro_compat & | |
f7f4bccb | 1419 | ~cpu_to_be32(JBD2_KNOWN_ROCOMPAT_FEATURES)) || |
470decc6 | 1420 | (sb->s_feature_incompat & |
f7f4bccb | 1421 | ~cpu_to_be32(JBD2_KNOWN_INCOMPAT_FEATURES))) { |
470decc6 DK |
1422 | printk (KERN_WARNING |
1423 | "JBD: Unrecognised features on journal\n"); | |
1424 | return -EINVAL; | |
1425 | } | |
1426 | } | |
1427 | ||
470decc6 DK |
1428 | /* Let the recovery code check whether it needs to recover any |
1429 | * data from the journal. */ | |
f7f4bccb | 1430 | if (jbd2_journal_recover(journal)) |
470decc6 DK |
1431 | goto recovery_error; |
1432 | ||
1433 | /* OK, we've finished with the dynamic journal bits: | |
1434 | * reinitialise the dynamic contents of the superblock in memory | |
1435 | * and reset them on disk. */ | |
1436 | if (journal_reset(journal)) | |
1437 | goto recovery_error; | |
1438 | ||
f7f4bccb MC |
1439 | journal->j_flags &= ~JBD2_ABORT; |
1440 | journal->j_flags |= JBD2_LOADED; | |
470decc6 DK |
1441 | return 0; |
1442 | ||
1443 | recovery_error: | |
1444 | printk (KERN_WARNING "JBD: recovery failed\n"); | |
1445 | return -EIO; | |
1446 | } | |
1447 | ||
1448 | /** | |
f7f4bccb | 1449 | * void jbd2_journal_destroy() - Release a journal_t structure. |
470decc6 DK |
1450 | * @journal: Journal to act on. |
1451 | * | |
1452 | * Release a journal_t structure once it is no longer in use by the | |
1453 | * journaled object. | |
44519faf | 1454 | * Return <0 if we couldn't clean up the journal. |
470decc6 | 1455 | */ |
44519faf | 1456 | int jbd2_journal_destroy(journal_t *journal) |
470decc6 | 1457 | { |
44519faf HK |
1458 | int err = 0; |
1459 | ||
470decc6 DK |
1460 | /* Wait for the commit thread to wake up and die. */ |
1461 | journal_kill_thread(journal); | |
1462 | ||
1463 | /* Force a final log commit */ | |
1464 | if (journal->j_running_transaction) | |
f7f4bccb | 1465 | jbd2_journal_commit_transaction(journal); |
470decc6 DK |
1466 | |
1467 | /* Force any old transactions to disk */ | |
1468 | ||
1469 | /* Totally anal locking here... */ | |
1470 | spin_lock(&journal->j_list_lock); | |
1471 | while (journal->j_checkpoint_transactions != NULL) { | |
1472 | spin_unlock(&journal->j_list_lock); | |
f7f4bccb | 1473 | jbd2_log_do_checkpoint(journal); |
470decc6 DK |
1474 | spin_lock(&journal->j_list_lock); |
1475 | } | |
1476 | ||
1477 | J_ASSERT(journal->j_running_transaction == NULL); | |
1478 | J_ASSERT(journal->j_committing_transaction == NULL); | |
1479 | J_ASSERT(journal->j_checkpoint_transactions == NULL); | |
1480 | spin_unlock(&journal->j_list_lock); | |
1481 | ||
470decc6 | 1482 | if (journal->j_sb_buffer) { |
44519faf HK |
1483 | if (!is_journal_aborted(journal)) { |
1484 | /* We can now mark the journal as empty. */ | |
1485 | journal->j_tail = 0; | |
1486 | journal->j_tail_sequence = | |
1487 | ++journal->j_transaction_sequence; | |
1488 | jbd2_journal_update_superblock(journal, 1); | |
1489 | } else { | |
1490 | err = -EIO; | |
1491 | } | |
470decc6 DK |
1492 | brelse(journal->j_sb_buffer); |
1493 | } | |
1494 | ||
8e85fb3f JL |
1495 | if (journal->j_proc_entry) |
1496 | jbd2_stats_proc_exit(journal); | |
470decc6 DK |
1497 | if (journal->j_inode) |
1498 | iput(journal->j_inode); | |
1499 | if (journal->j_revoke) | |
f7f4bccb | 1500 | jbd2_journal_destroy_revoke(journal); |
470decc6 DK |
1501 | kfree(journal->j_wbuf); |
1502 | kfree(journal); | |
44519faf HK |
1503 | |
1504 | return err; | |
470decc6 DK |
1505 | } |
1506 | ||
1507 | ||
1508 | /** | |
f7f4bccb | 1509 | *int jbd2_journal_check_used_features () - Check if features specified are used. |
470decc6 DK |
1510 | * @journal: Journal to check. |
1511 | * @compat: bitmask of compatible features | |
1512 | * @ro: bitmask of features that force read-only mount | |
1513 | * @incompat: bitmask of incompatible features | |
1514 | * | |
1515 | * Check whether the journal uses all of a given set of | |
1516 | * features. Return true (non-zero) if it does. | |
1517 | **/ | |
1518 | ||
f7f4bccb | 1519 | int jbd2_journal_check_used_features (journal_t *journal, unsigned long compat, |
470decc6 DK |
1520 | unsigned long ro, unsigned long incompat) |
1521 | { | |
1522 | journal_superblock_t *sb; | |
1523 | ||
1524 | if (!compat && !ro && !incompat) | |
1525 | return 1; | |
1526 | if (journal->j_format_version == 1) | |
1527 | return 0; | |
1528 | ||
1529 | sb = journal->j_superblock; | |
1530 | ||
1531 | if (((be32_to_cpu(sb->s_feature_compat) & compat) == compat) && | |
1532 | ((be32_to_cpu(sb->s_feature_ro_compat) & ro) == ro) && | |
1533 | ((be32_to_cpu(sb->s_feature_incompat) & incompat) == incompat)) | |
1534 | return 1; | |
1535 | ||
1536 | return 0; | |
1537 | } | |
1538 | ||
1539 | /** | |
f7f4bccb | 1540 | * int jbd2_journal_check_available_features() - Check feature set in journalling layer |
470decc6 DK |
1541 | * @journal: Journal to check. |
1542 | * @compat: bitmask of compatible features | |
1543 | * @ro: bitmask of features that force read-only mount | |
1544 | * @incompat: bitmask of incompatible features | |
1545 | * | |
1546 | * Check whether the journaling code supports the use of | |
1547 | * all of a given set of features on this journal. Return true | |
1548 | * (non-zero) if it can. */ | |
1549 | ||
f7f4bccb | 1550 | int jbd2_journal_check_available_features (journal_t *journal, unsigned long compat, |
470decc6 DK |
1551 | unsigned long ro, unsigned long incompat) |
1552 | { | |
1553 | journal_superblock_t *sb; | |
1554 | ||
1555 | if (!compat && !ro && !incompat) | |
1556 | return 1; | |
1557 | ||
1558 | sb = journal->j_superblock; | |
1559 | ||
1560 | /* We can support any known requested features iff the | |
1561 | * superblock is in version 2. Otherwise we fail to support any | |
1562 | * extended sb features. */ | |
1563 | ||
1564 | if (journal->j_format_version != 2) | |
1565 | return 0; | |
1566 | ||
f7f4bccb MC |
1567 | if ((compat & JBD2_KNOWN_COMPAT_FEATURES) == compat && |
1568 | (ro & JBD2_KNOWN_ROCOMPAT_FEATURES) == ro && | |
1569 | (incompat & JBD2_KNOWN_INCOMPAT_FEATURES) == incompat) | |
470decc6 DK |
1570 | return 1; |
1571 | ||
1572 | return 0; | |
1573 | } | |
1574 | ||
1575 | /** | |
f7f4bccb | 1576 | * int jbd2_journal_set_features () - Mark a given journal feature in the superblock |
470decc6 DK |
1577 | * @journal: Journal to act on. |
1578 | * @compat: bitmask of compatible features | |
1579 | * @ro: bitmask of features that force read-only mount | |
1580 | * @incompat: bitmask of incompatible features | |
1581 | * | |
1582 | * Mark a given journal feature as present on the | |
1583 | * superblock. Returns true if the requested features could be set. | |
1584 | * | |
1585 | */ | |
1586 | ||
f7f4bccb | 1587 | int jbd2_journal_set_features (journal_t *journal, unsigned long compat, |
470decc6 DK |
1588 | unsigned long ro, unsigned long incompat) |
1589 | { | |
1590 | journal_superblock_t *sb; | |
1591 | ||
f7f4bccb | 1592 | if (jbd2_journal_check_used_features(journal, compat, ro, incompat)) |
470decc6 DK |
1593 | return 1; |
1594 | ||
f7f4bccb | 1595 | if (!jbd2_journal_check_available_features(journal, compat, ro, incompat)) |
470decc6 DK |
1596 | return 0; |
1597 | ||
1598 | jbd_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n", | |
1599 | compat, ro, incompat); | |
1600 | ||
1601 | sb = journal->j_superblock; | |
1602 | ||
1603 | sb->s_feature_compat |= cpu_to_be32(compat); | |
1604 | sb->s_feature_ro_compat |= cpu_to_be32(ro); | |
1605 | sb->s_feature_incompat |= cpu_to_be32(incompat); | |
1606 | ||
1607 | return 1; | |
1608 | } | |
1609 | ||
818d276c GS |
1610 | /* |
1611 | * jbd2_journal_clear_features () - Clear a given journal feature in the | |
1612 | * superblock | |
1613 | * @journal: Journal to act on. | |
1614 | * @compat: bitmask of compatible features | |
1615 | * @ro: bitmask of features that force read-only mount | |
1616 | * @incompat: bitmask of incompatible features | |
1617 | * | |
1618 | * Clear a given journal feature as present on the | |
1619 | * superblock. | |
1620 | */ | |
1621 | void jbd2_journal_clear_features(journal_t *journal, unsigned long compat, | |
1622 | unsigned long ro, unsigned long incompat) | |
1623 | { | |
1624 | journal_superblock_t *sb; | |
1625 | ||
1626 | jbd_debug(1, "Clear features 0x%lx/0x%lx/0x%lx\n", | |
1627 | compat, ro, incompat); | |
1628 | ||
1629 | sb = journal->j_superblock; | |
1630 | ||
1631 | sb->s_feature_compat &= ~cpu_to_be32(compat); | |
1632 | sb->s_feature_ro_compat &= ~cpu_to_be32(ro); | |
1633 | sb->s_feature_incompat &= ~cpu_to_be32(incompat); | |
1634 | } | |
1635 | EXPORT_SYMBOL(jbd2_journal_clear_features); | |
470decc6 DK |
1636 | |
1637 | /** | |
f7f4bccb | 1638 | * int jbd2_journal_update_format () - Update on-disk journal structure. |
470decc6 DK |
1639 | * @journal: Journal to act on. |
1640 | * | |
1641 | * Given an initialised but unloaded journal struct, poke about in the | |
1642 | * on-disk structure to update it to the most recent supported version. | |
1643 | */ | |
f7f4bccb | 1644 | int jbd2_journal_update_format (journal_t *journal) |
470decc6 DK |
1645 | { |
1646 | journal_superblock_t *sb; | |
1647 | int err; | |
1648 | ||
1649 | err = journal_get_superblock(journal); | |
1650 | if (err) | |
1651 | return err; | |
1652 | ||
1653 | sb = journal->j_superblock; | |
1654 | ||
1655 | switch (be32_to_cpu(sb->s_header.h_blocktype)) { | |
f7f4bccb | 1656 | case JBD2_SUPERBLOCK_V2: |
470decc6 | 1657 | return 0; |
f7f4bccb | 1658 | case JBD2_SUPERBLOCK_V1: |
470decc6 DK |
1659 | return journal_convert_superblock_v1(journal, sb); |
1660 | default: | |
1661 | break; | |
1662 | } | |
1663 | return -EINVAL; | |
1664 | } | |
1665 | ||
1666 | static int journal_convert_superblock_v1(journal_t *journal, | |
1667 | journal_superblock_t *sb) | |
1668 | { | |
1669 | int offset, blocksize; | |
1670 | struct buffer_head *bh; | |
1671 | ||
1672 | printk(KERN_WARNING | |
1673 | "JBD: Converting superblock from version 1 to 2.\n"); | |
1674 | ||
1675 | /* Pre-initialise new fields to zero */ | |
1676 | offset = ((char *) &(sb->s_feature_compat)) - ((char *) sb); | |
1677 | blocksize = be32_to_cpu(sb->s_blocksize); | |
1678 | memset(&sb->s_feature_compat, 0, blocksize-offset); | |
1679 | ||
1680 | sb->s_nr_users = cpu_to_be32(1); | |
f7f4bccb | 1681 | sb->s_header.h_blocktype = cpu_to_be32(JBD2_SUPERBLOCK_V2); |
470decc6 DK |
1682 | journal->j_format_version = 2; |
1683 | ||
1684 | bh = journal->j_sb_buffer; | |
1685 | BUFFER_TRACE(bh, "marking dirty"); | |
1686 | mark_buffer_dirty(bh); | |
1687 | sync_dirty_buffer(bh); | |
1688 | return 0; | |
1689 | } | |
1690 | ||
1691 | ||
1692 | /** | |
f7f4bccb | 1693 | * int jbd2_journal_flush () - Flush journal |
470decc6 DK |
1694 | * @journal: Journal to act on. |
1695 | * | |
1696 | * Flush all data for a given journal to disk and empty the journal. | |
1697 | * Filesystems can use this when remounting readonly to ensure that | |
1698 | * recovery does not need to happen on remount. | |
1699 | */ | |
1700 | ||
f7f4bccb | 1701 | int jbd2_journal_flush(journal_t *journal) |
470decc6 DK |
1702 | { |
1703 | int err = 0; | |
1704 | transaction_t *transaction = NULL; | |
1705 | unsigned long old_tail; | |
1706 | ||
1707 | spin_lock(&journal->j_state_lock); | |
1708 | ||
1709 | /* Force everything buffered to the log... */ | |
1710 | if (journal->j_running_transaction) { | |
1711 | transaction = journal->j_running_transaction; | |
f7f4bccb | 1712 | __jbd2_log_start_commit(journal, transaction->t_tid); |
470decc6 DK |
1713 | } else if (journal->j_committing_transaction) |
1714 | transaction = journal->j_committing_transaction; | |
1715 | ||
1716 | /* Wait for the log commit to complete... */ | |
1717 | if (transaction) { | |
1718 | tid_t tid = transaction->t_tid; | |
1719 | ||
1720 | spin_unlock(&journal->j_state_lock); | |
f7f4bccb | 1721 | jbd2_log_wait_commit(journal, tid); |
470decc6 DK |
1722 | } else { |
1723 | spin_unlock(&journal->j_state_lock); | |
1724 | } | |
1725 | ||
1726 | /* ...and flush everything in the log out to disk. */ | |
1727 | spin_lock(&journal->j_list_lock); | |
1728 | while (!err && journal->j_checkpoint_transactions != NULL) { | |
1729 | spin_unlock(&journal->j_list_lock); | |
44519faf | 1730 | mutex_lock(&journal->j_checkpoint_mutex); |
f7f4bccb | 1731 | err = jbd2_log_do_checkpoint(journal); |
44519faf | 1732 | mutex_unlock(&journal->j_checkpoint_mutex); |
470decc6 DK |
1733 | spin_lock(&journal->j_list_lock); |
1734 | } | |
1735 | spin_unlock(&journal->j_list_lock); | |
44519faf HK |
1736 | |
1737 | if (is_journal_aborted(journal)) | |
1738 | return -EIO; | |
1739 | ||
f7f4bccb | 1740 | jbd2_cleanup_journal_tail(journal); |
470decc6 DK |
1741 | |
1742 | /* Finally, mark the journal as really needing no recovery. | |
1743 | * This sets s_start==0 in the underlying superblock, which is | |
1744 | * the magic code for a fully-recovered superblock. Any future | |
1745 | * commits of data to the journal will restore the current | |
1746 | * s_start value. */ | |
1747 | spin_lock(&journal->j_state_lock); | |
1748 | old_tail = journal->j_tail; | |
1749 | journal->j_tail = 0; | |
1750 | spin_unlock(&journal->j_state_lock); | |
f7f4bccb | 1751 | jbd2_journal_update_superblock(journal, 1); |
470decc6 DK |
1752 | spin_lock(&journal->j_state_lock); |
1753 | journal->j_tail = old_tail; | |
1754 | ||
1755 | J_ASSERT(!journal->j_running_transaction); | |
1756 | J_ASSERT(!journal->j_committing_transaction); | |
1757 | J_ASSERT(!journal->j_checkpoint_transactions); | |
1758 | J_ASSERT(journal->j_head == journal->j_tail); | |
1759 | J_ASSERT(journal->j_tail_sequence == journal->j_transaction_sequence); | |
1760 | spin_unlock(&journal->j_state_lock); | |
44519faf | 1761 | return 0; |
470decc6 DK |
1762 | } |
1763 | ||
1764 | /** | |
f7f4bccb | 1765 | * int jbd2_journal_wipe() - Wipe journal contents |
470decc6 DK |
1766 | * @journal: Journal to act on. |
1767 | * @write: flag (see below) | |
1768 | * | |
1769 | * Wipe out all of the contents of a journal, safely. This will produce | |
1770 | * a warning if the journal contains any valid recovery information. | |
f7f4bccb | 1771 | * Must be called between journal_init_*() and jbd2_journal_load(). |
470decc6 DK |
1772 | * |
1773 | * If 'write' is non-zero, then we wipe out the journal on disk; otherwise | |
1774 | * we merely suppress recovery. | |
1775 | */ | |
1776 | ||
f7f4bccb | 1777 | int jbd2_journal_wipe(journal_t *journal, int write) |
470decc6 DK |
1778 | { |
1779 | journal_superblock_t *sb; | |
1780 | int err = 0; | |
1781 | ||
f7f4bccb | 1782 | J_ASSERT (!(journal->j_flags & JBD2_LOADED)); |
470decc6 DK |
1783 | |
1784 | err = load_superblock(journal); | |
1785 | if (err) | |
1786 | return err; | |
1787 | ||
1788 | sb = journal->j_superblock; | |
1789 | ||
1790 | if (!journal->j_tail) | |
1791 | goto no_recovery; | |
1792 | ||
1793 | printk (KERN_WARNING "JBD: %s recovery information on journal\n", | |
1794 | write ? "Clearing" : "Ignoring"); | |
1795 | ||
f7f4bccb | 1796 | err = jbd2_journal_skip_recovery(journal); |
470decc6 | 1797 | if (write) |
f7f4bccb | 1798 | jbd2_journal_update_superblock(journal, 1); |
470decc6 DK |
1799 | |
1800 | no_recovery: | |
1801 | return err; | |
1802 | } | |
1803 | ||
470decc6 DK |
1804 | /* |
1805 | * Journal abort has very specific semantics, which we describe | |
1806 | * for journal abort. | |
1807 | * | |
1808 | * Two internal function, which provide abort to te jbd layer | |
1809 | * itself are here. | |
1810 | */ | |
1811 | ||
1812 | /* | |
1813 | * Quick version for internal journal use (doesn't lock the journal). | |
1814 | * Aborts hard --- we mark the abort as occurred, but do _nothing_ else, | |
1815 | * and don't attempt to make any other journal updates. | |
1816 | */ | |
f7f4bccb | 1817 | void __jbd2_journal_abort_hard(journal_t *journal) |
470decc6 DK |
1818 | { |
1819 | transaction_t *transaction; | |
470decc6 | 1820 | |
f7f4bccb | 1821 | if (journal->j_flags & JBD2_ABORT) |
470decc6 DK |
1822 | return; |
1823 | ||
1824 | printk(KERN_ERR "Aborting journal on device %s.\n", | |
05496769 | 1825 | journal->j_devname); |
470decc6 DK |
1826 | |
1827 | spin_lock(&journal->j_state_lock); | |
f7f4bccb | 1828 | journal->j_flags |= JBD2_ABORT; |
470decc6 DK |
1829 | transaction = journal->j_running_transaction; |
1830 | if (transaction) | |
f7f4bccb | 1831 | __jbd2_log_start_commit(journal, transaction->t_tid); |
470decc6 DK |
1832 | spin_unlock(&journal->j_state_lock); |
1833 | } | |
1834 | ||
1835 | /* Soft abort: record the abort error status in the journal superblock, | |
1836 | * but don't do any other IO. */ | |
1837 | static void __journal_abort_soft (journal_t *journal, int errno) | |
1838 | { | |
f7f4bccb | 1839 | if (journal->j_flags & JBD2_ABORT) |
470decc6 DK |
1840 | return; |
1841 | ||
1842 | if (!journal->j_errno) | |
1843 | journal->j_errno = errno; | |
1844 | ||
f7f4bccb | 1845 | __jbd2_journal_abort_hard(journal); |
470decc6 DK |
1846 | |
1847 | if (errno) | |
f7f4bccb | 1848 | jbd2_journal_update_superblock(journal, 1); |
470decc6 DK |
1849 | } |
1850 | ||
1851 | /** | |
f7f4bccb | 1852 | * void jbd2_journal_abort () - Shutdown the journal immediately. |
470decc6 DK |
1853 | * @journal: the journal to shutdown. |
1854 | * @errno: an error number to record in the journal indicating | |
1855 | * the reason for the shutdown. | |
1856 | * | |
1857 | * Perform a complete, immediate shutdown of the ENTIRE | |
1858 | * journal (not of a single transaction). This operation cannot be | |
1859 | * undone without closing and reopening the journal. | |
1860 | * | |
f7f4bccb | 1861 | * The jbd2_journal_abort function is intended to support higher level error |
470decc6 DK |
1862 | * recovery mechanisms such as the ext2/ext3 remount-readonly error |
1863 | * mode. | |
1864 | * | |
1865 | * Journal abort has very specific semantics. Any existing dirty, | |
1866 | * unjournaled buffers in the main filesystem will still be written to | |
1867 | * disk by bdflush, but the journaling mechanism will be suspended | |
1868 | * immediately and no further transaction commits will be honoured. | |
1869 | * | |
1870 | * Any dirty, journaled buffers will be written back to disk without | |
1871 | * hitting the journal. Atomicity cannot be guaranteed on an aborted | |
1872 | * filesystem, but we _do_ attempt to leave as much data as possible | |
1873 | * behind for fsck to use for cleanup. | |
1874 | * | |
1875 | * Any attempt to get a new transaction handle on a journal which is in | |
1876 | * ABORT state will just result in an -EROFS error return. A | |
f7f4bccb | 1877 | * jbd2_journal_stop on an existing handle will return -EIO if we have |
470decc6 DK |
1878 | * entered abort state during the update. |
1879 | * | |
1880 | * Recursive transactions are not disturbed by journal abort until the | |
f7f4bccb | 1881 | * final jbd2_journal_stop, which will receive the -EIO error. |
470decc6 | 1882 | * |
f7f4bccb | 1883 | * Finally, the jbd2_journal_abort call allows the caller to supply an errno |
470decc6 DK |
1884 | * which will be recorded (if possible) in the journal superblock. This |
1885 | * allows a client to record failure conditions in the middle of a | |
1886 | * transaction without having to complete the transaction to record the | |
1887 | * failure to disk. ext3_error, for example, now uses this | |
1888 | * functionality. | |
1889 | * | |
1890 | * Errors which originate from within the journaling layer will NOT | |
1891 | * supply an errno; a null errno implies that absolutely no further | |
1892 | * writes are done to the journal (unless there are any already in | |
1893 | * progress). | |
1894 | * | |
1895 | */ | |
1896 | ||
f7f4bccb | 1897 | void jbd2_journal_abort(journal_t *journal, int errno) |
470decc6 DK |
1898 | { |
1899 | __journal_abort_soft(journal, errno); | |
1900 | } | |
1901 | ||
1902 | /** | |
f7f4bccb | 1903 | * int jbd2_journal_errno () - returns the journal's error state. |
470decc6 DK |
1904 | * @journal: journal to examine. |
1905 | * | |
f7f4bccb | 1906 | * This is the errno numbet set with jbd2_journal_abort(), the last |
470decc6 DK |
1907 | * time the journal was mounted - if the journal was stopped |
1908 | * without calling abort this will be 0. | |
1909 | * | |
1910 | * If the journal has been aborted on this mount time -EROFS will | |
1911 | * be returned. | |
1912 | */ | |
f7f4bccb | 1913 | int jbd2_journal_errno(journal_t *journal) |
470decc6 DK |
1914 | { |
1915 | int err; | |
1916 | ||
1917 | spin_lock(&journal->j_state_lock); | |
f7f4bccb | 1918 | if (journal->j_flags & JBD2_ABORT) |
470decc6 DK |
1919 | err = -EROFS; |
1920 | else | |
1921 | err = journal->j_errno; | |
1922 | spin_unlock(&journal->j_state_lock); | |
1923 | return err; | |
1924 | } | |
1925 | ||
1926 | /** | |
f7f4bccb | 1927 | * int jbd2_journal_clear_err () - clears the journal's error state |
470decc6 DK |
1928 | * @journal: journal to act on. |
1929 | * | |
1930 | * An error must be cleared or Acked to take a FS out of readonly | |
1931 | * mode. | |
1932 | */ | |
f7f4bccb | 1933 | int jbd2_journal_clear_err(journal_t *journal) |
470decc6 DK |
1934 | { |
1935 | int err = 0; | |
1936 | ||
1937 | spin_lock(&journal->j_state_lock); | |
f7f4bccb | 1938 | if (journal->j_flags & JBD2_ABORT) |
470decc6 DK |
1939 | err = -EROFS; |
1940 | else | |
1941 | journal->j_errno = 0; | |
1942 | spin_unlock(&journal->j_state_lock); | |
1943 | return err; | |
1944 | } | |
1945 | ||
1946 | /** | |
f7f4bccb | 1947 | * void jbd2_journal_ack_err() - Ack journal err. |
470decc6 DK |
1948 | * @journal: journal to act on. |
1949 | * | |
1950 | * An error must be cleared or Acked to take a FS out of readonly | |
1951 | * mode. | |
1952 | */ | |
f7f4bccb | 1953 | void jbd2_journal_ack_err(journal_t *journal) |
470decc6 DK |
1954 | { |
1955 | spin_lock(&journal->j_state_lock); | |
1956 | if (journal->j_errno) | |
f7f4bccb | 1957 | journal->j_flags |= JBD2_ACK_ERR; |
470decc6 DK |
1958 | spin_unlock(&journal->j_state_lock); |
1959 | } | |
1960 | ||
f7f4bccb | 1961 | int jbd2_journal_blocks_per_page(struct inode *inode) |
470decc6 DK |
1962 | { |
1963 | return 1 << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits); | |
1964 | } | |
1965 | ||
b517bea1 ZB |
1966 | /* |
1967 | * helper functions to deal with 32 or 64bit block numbers. | |
1968 | */ | |
1969 | size_t journal_tag_bytes(journal_t *journal) | |
1970 | { | |
1971 | if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT)) | |
cd02ff0b | 1972 | return JBD2_TAG_SIZE64; |
b517bea1 | 1973 | else |
cd02ff0b | 1974 | return JBD2_TAG_SIZE32; |
b517bea1 ZB |
1975 | } |
1976 | ||
470decc6 DK |
1977 | /* |
1978 | * Journal_head storage management | |
1979 | */ | |
e18b890b | 1980 | static struct kmem_cache *jbd2_journal_head_cache; |
e23291b9 | 1981 | #ifdef CONFIG_JBD2_DEBUG |
470decc6 DK |
1982 | static atomic_t nr_journal_heads = ATOMIC_INIT(0); |
1983 | #endif | |
1984 | ||
f7f4bccb | 1985 | static int journal_init_jbd2_journal_head_cache(void) |
470decc6 DK |
1986 | { |
1987 | int retval; | |
1988 | ||
1076d17a | 1989 | J_ASSERT(jbd2_journal_head_cache == NULL); |
a920e941 | 1990 | jbd2_journal_head_cache = kmem_cache_create("jbd2_journal_head", |
470decc6 DK |
1991 | sizeof(struct journal_head), |
1992 | 0, /* offset */ | |
77160957 | 1993 | SLAB_TEMPORARY, /* flags */ |
20c2df83 | 1994 | NULL); /* ctor */ |
470decc6 | 1995 | retval = 0; |
1076d17a | 1996 | if (!jbd2_journal_head_cache) { |
470decc6 DK |
1997 | retval = -ENOMEM; |
1998 | printk(KERN_EMERG "JBD: no memory for journal_head cache\n"); | |
1999 | } | |
2000 | return retval; | |
2001 | } | |
2002 | ||
f7f4bccb | 2003 | static void jbd2_journal_destroy_jbd2_journal_head_cache(void) |
470decc6 | 2004 | { |
8a9362eb DG |
2005 | if (jbd2_journal_head_cache) { |
2006 | kmem_cache_destroy(jbd2_journal_head_cache); | |
2007 | jbd2_journal_head_cache = NULL; | |
2008 | } | |
470decc6 DK |
2009 | } |
2010 | ||
2011 | /* | |
2012 | * journal_head splicing and dicing | |
2013 | */ | |
2014 | static struct journal_head *journal_alloc_journal_head(void) | |
2015 | { | |
2016 | struct journal_head *ret; | |
2017 | static unsigned long last_warning; | |
2018 | ||
e23291b9 | 2019 | #ifdef CONFIG_JBD2_DEBUG |
470decc6 DK |
2020 | atomic_inc(&nr_journal_heads); |
2021 | #endif | |
f7f4bccb | 2022 | ret = kmem_cache_alloc(jbd2_journal_head_cache, GFP_NOFS); |
1076d17a | 2023 | if (!ret) { |
470decc6 DK |
2024 | jbd_debug(1, "out of memory for journal_head\n"); |
2025 | if (time_after(jiffies, last_warning + 5*HZ)) { | |
2026 | printk(KERN_NOTICE "ENOMEM in %s, retrying.\n", | |
329d291f | 2027 | __func__); |
470decc6 DK |
2028 | last_warning = jiffies; |
2029 | } | |
1076d17a | 2030 | while (!ret) { |
470decc6 | 2031 | yield(); |
f7f4bccb | 2032 | ret = kmem_cache_alloc(jbd2_journal_head_cache, GFP_NOFS); |
470decc6 DK |
2033 | } |
2034 | } | |
2035 | return ret; | |
2036 | } | |
2037 | ||
2038 | static void journal_free_journal_head(struct journal_head *jh) | |
2039 | { | |
e23291b9 | 2040 | #ifdef CONFIG_JBD2_DEBUG |
470decc6 | 2041 | atomic_dec(&nr_journal_heads); |
cd02ff0b | 2042 | memset(jh, JBD2_POISON_FREE, sizeof(*jh)); |
470decc6 | 2043 | #endif |
f7f4bccb | 2044 | kmem_cache_free(jbd2_journal_head_cache, jh); |
470decc6 DK |
2045 | } |
2046 | ||
2047 | /* | |
2048 | * A journal_head is attached to a buffer_head whenever JBD has an | |
2049 | * interest in the buffer. | |
2050 | * | |
2051 | * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit | |
2052 | * is set. This bit is tested in core kernel code where we need to take | |
2053 | * JBD-specific actions. Testing the zeroness of ->b_private is not reliable | |
2054 | * there. | |
2055 | * | |
2056 | * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one. | |
2057 | * | |
2058 | * When a buffer has its BH_JBD bit set it is immune from being released by | |
2059 | * core kernel code, mainly via ->b_count. | |
2060 | * | |
2061 | * A journal_head may be detached from its buffer_head when the journal_head's | |
2062 | * b_transaction, b_cp_transaction and b_next_transaction pointers are NULL. | |
f7f4bccb | 2063 | * Various places in JBD call jbd2_journal_remove_journal_head() to indicate that the |
470decc6 DK |
2064 | * journal_head can be dropped if needed. |
2065 | * | |
2066 | * Various places in the kernel want to attach a journal_head to a buffer_head | |
2067 | * _before_ attaching the journal_head to a transaction. To protect the | |
f7f4bccb | 2068 | * journal_head in this situation, jbd2_journal_add_journal_head elevates the |
470decc6 | 2069 | * journal_head's b_jcount refcount by one. The caller must call |
f7f4bccb | 2070 | * jbd2_journal_put_journal_head() to undo this. |
470decc6 DK |
2071 | * |
2072 | * So the typical usage would be: | |
2073 | * | |
2074 | * (Attach a journal_head if needed. Increments b_jcount) | |
f7f4bccb | 2075 | * struct journal_head *jh = jbd2_journal_add_journal_head(bh); |
470decc6 DK |
2076 | * ... |
2077 | * jh->b_transaction = xxx; | |
f7f4bccb | 2078 | * jbd2_journal_put_journal_head(jh); |
470decc6 DK |
2079 | * |
2080 | * Now, the journal_head's b_jcount is zero, but it is safe from being released | |
2081 | * because it has a non-zero b_transaction. | |
2082 | */ | |
2083 | ||
2084 | /* | |
2085 | * Give a buffer_head a journal_head. | |
2086 | * | |
2087 | * Doesn't need the journal lock. | |
2088 | * May sleep. | |
2089 | */ | |
f7f4bccb | 2090 | struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh) |
470decc6 DK |
2091 | { |
2092 | struct journal_head *jh; | |
2093 | struct journal_head *new_jh = NULL; | |
2094 | ||
2095 | repeat: | |
2096 | if (!buffer_jbd(bh)) { | |
2097 | new_jh = journal_alloc_journal_head(); | |
2098 | memset(new_jh, 0, sizeof(*new_jh)); | |
2099 | } | |
2100 | ||
2101 | jbd_lock_bh_journal_head(bh); | |
2102 | if (buffer_jbd(bh)) { | |
2103 | jh = bh2jh(bh); | |
2104 | } else { | |
2105 | J_ASSERT_BH(bh, | |
2106 | (atomic_read(&bh->b_count) > 0) || | |
2107 | (bh->b_page && bh->b_page->mapping)); | |
2108 | ||
2109 | if (!new_jh) { | |
2110 | jbd_unlock_bh_journal_head(bh); | |
2111 | goto repeat; | |
2112 | } | |
2113 | ||
2114 | jh = new_jh; | |
2115 | new_jh = NULL; /* We consumed it */ | |
2116 | set_buffer_jbd(bh); | |
2117 | bh->b_private = jh; | |
2118 | jh->b_bh = bh; | |
2119 | get_bh(bh); | |
2120 | BUFFER_TRACE(bh, "added journal_head"); | |
2121 | } | |
2122 | jh->b_jcount++; | |
2123 | jbd_unlock_bh_journal_head(bh); | |
2124 | if (new_jh) | |
2125 | journal_free_journal_head(new_jh); | |
2126 | return bh->b_private; | |
2127 | } | |
2128 | ||
2129 | /* | |
2130 | * Grab a ref against this buffer_head's journal_head. If it ended up not | |
2131 | * having a journal_head, return NULL | |
2132 | */ | |
f7f4bccb | 2133 | struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh) |
470decc6 DK |
2134 | { |
2135 | struct journal_head *jh = NULL; | |
2136 | ||
2137 | jbd_lock_bh_journal_head(bh); | |
2138 | if (buffer_jbd(bh)) { | |
2139 | jh = bh2jh(bh); | |
2140 | jh->b_jcount++; | |
2141 | } | |
2142 | jbd_unlock_bh_journal_head(bh); | |
2143 | return jh; | |
2144 | } | |
2145 | ||
2146 | static void __journal_remove_journal_head(struct buffer_head *bh) | |
2147 | { | |
2148 | struct journal_head *jh = bh2jh(bh); | |
2149 | ||
2150 | J_ASSERT_JH(jh, jh->b_jcount >= 0); | |
2151 | ||
2152 | get_bh(bh); | |
2153 | if (jh->b_jcount == 0) { | |
2154 | if (jh->b_transaction == NULL && | |
2155 | jh->b_next_transaction == NULL && | |
2156 | jh->b_cp_transaction == NULL) { | |
2157 | J_ASSERT_JH(jh, jh->b_jlist == BJ_None); | |
2158 | J_ASSERT_BH(bh, buffer_jbd(bh)); | |
2159 | J_ASSERT_BH(bh, jh2bh(jh) == bh); | |
2160 | BUFFER_TRACE(bh, "remove journal_head"); | |
2161 | if (jh->b_frozen_data) { | |
2162 | printk(KERN_WARNING "%s: freeing " | |
2163 | "b_frozen_data\n", | |
329d291f | 2164 | __func__); |
af1e76d6 | 2165 | jbd2_free(jh->b_frozen_data, bh->b_size); |
470decc6 DK |
2166 | } |
2167 | if (jh->b_committed_data) { | |
2168 | printk(KERN_WARNING "%s: freeing " | |
2169 | "b_committed_data\n", | |
329d291f | 2170 | __func__); |
af1e76d6 | 2171 | jbd2_free(jh->b_committed_data, bh->b_size); |
470decc6 DK |
2172 | } |
2173 | bh->b_private = NULL; | |
2174 | jh->b_bh = NULL; /* debug, really */ | |
2175 | clear_buffer_jbd(bh); | |
2176 | __brelse(bh); | |
2177 | journal_free_journal_head(jh); | |
2178 | } else { | |
2179 | BUFFER_TRACE(bh, "journal_head was locked"); | |
2180 | } | |
2181 | } | |
2182 | } | |
2183 | ||
2184 | /* | |
f7f4bccb | 2185 | * jbd2_journal_remove_journal_head(): if the buffer isn't attached to a transaction |
470decc6 DK |
2186 | * and has a zero b_jcount then remove and release its journal_head. If we did |
2187 | * see that the buffer is not used by any transaction we also "logically" | |
2188 | * decrement ->b_count. | |
2189 | * | |
2190 | * We in fact take an additional increment on ->b_count as a convenience, | |
2191 | * because the caller usually wants to do additional things with the bh | |
2192 | * after calling here. | |
f7f4bccb | 2193 | * The caller of jbd2_journal_remove_journal_head() *must* run __brelse(bh) at some |
470decc6 DK |
2194 | * time. Once the caller has run __brelse(), the buffer is eligible for |
2195 | * reaping by try_to_free_buffers(). | |
2196 | */ | |
f7f4bccb | 2197 | void jbd2_journal_remove_journal_head(struct buffer_head *bh) |
470decc6 DK |
2198 | { |
2199 | jbd_lock_bh_journal_head(bh); | |
2200 | __journal_remove_journal_head(bh); | |
2201 | jbd_unlock_bh_journal_head(bh); | |
2202 | } | |
2203 | ||
2204 | /* | |
2205 | * Drop a reference on the passed journal_head. If it fell to zero then try to | |
2206 | * release the journal_head from the buffer_head. | |
2207 | */ | |
f7f4bccb | 2208 | void jbd2_journal_put_journal_head(struct journal_head *jh) |
470decc6 DK |
2209 | { |
2210 | struct buffer_head *bh = jh2bh(jh); | |
2211 | ||
2212 | jbd_lock_bh_journal_head(bh); | |
2213 | J_ASSERT_JH(jh, jh->b_jcount > 0); | |
2214 | --jh->b_jcount; | |
2215 | if (!jh->b_jcount && !jh->b_transaction) { | |
2216 | __journal_remove_journal_head(bh); | |
2217 | __brelse(bh); | |
2218 | } | |
2219 | jbd_unlock_bh_journal_head(bh); | |
2220 | } | |
2221 | ||
c851ed54 JK |
2222 | /* |
2223 | * Initialize jbd inode head | |
2224 | */ | |
2225 | void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode) | |
2226 | { | |
2227 | jinode->i_transaction = NULL; | |
2228 | jinode->i_next_transaction = NULL; | |
2229 | jinode->i_vfs_inode = inode; | |
2230 | jinode->i_flags = 0; | |
2231 | INIT_LIST_HEAD(&jinode->i_list); | |
2232 | } | |
2233 | ||
2234 | /* | |
2235 | * Function to be called before we start removing inode from memory (i.e., | |
2236 | * clear_inode() is a fine place to be called from). It removes inode from | |
2237 | * transaction's lists. | |
2238 | */ | |
2239 | void jbd2_journal_release_jbd_inode(journal_t *journal, | |
2240 | struct jbd2_inode *jinode) | |
2241 | { | |
2242 | int writeout = 0; | |
2243 | ||
2244 | if (!journal) | |
2245 | return; | |
2246 | restart: | |
2247 | spin_lock(&journal->j_list_lock); | |
2248 | /* Is commit writing out inode - we have to wait */ | |
2249 | if (jinode->i_flags & JI_COMMIT_RUNNING) { | |
2250 | wait_queue_head_t *wq; | |
2251 | DEFINE_WAIT_BIT(wait, &jinode->i_flags, __JI_COMMIT_RUNNING); | |
2252 | wq = bit_waitqueue(&jinode->i_flags, __JI_COMMIT_RUNNING); | |
2253 | prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE); | |
2254 | spin_unlock(&journal->j_list_lock); | |
2255 | schedule(); | |
2256 | finish_wait(wq, &wait.wait); | |
2257 | goto restart; | |
2258 | } | |
2259 | ||
2260 | /* Do we need to wait for data writeback? */ | |
2261 | if (journal->j_committing_transaction == jinode->i_transaction) | |
2262 | writeout = 1; | |
2263 | if (jinode->i_transaction) { | |
2264 | list_del(&jinode->i_list); | |
2265 | jinode->i_transaction = NULL; | |
2266 | } | |
2267 | spin_unlock(&journal->j_list_lock); | |
2268 | } | |
2269 | ||
470decc6 | 2270 | /* |
0f49d5d0 | 2271 | * debugfs tunables |
470decc6 | 2272 | */ |
6f38c74f JS |
2273 | #ifdef CONFIG_JBD2_DEBUG |
2274 | u8 jbd2_journal_enable_debug __read_mostly; | |
f7f4bccb | 2275 | EXPORT_SYMBOL(jbd2_journal_enable_debug); |
470decc6 | 2276 | |
0f49d5d0 | 2277 | #define JBD2_DEBUG_NAME "jbd2-debug" |
470decc6 | 2278 | |
6f38c74f JS |
2279 | static struct dentry *jbd2_debugfs_dir; |
2280 | static struct dentry *jbd2_debug; | |
470decc6 | 2281 | |
0f49d5d0 JS |
2282 | static void __init jbd2_create_debugfs_entry(void) |
2283 | { | |
2284 | jbd2_debugfs_dir = debugfs_create_dir("jbd2", NULL); | |
2285 | if (jbd2_debugfs_dir) | |
2286 | jbd2_debug = debugfs_create_u8(JBD2_DEBUG_NAME, S_IRUGO, | |
2287 | jbd2_debugfs_dir, | |
2288 | &jbd2_journal_enable_debug); | |
470decc6 DK |
2289 | } |
2290 | ||
0f49d5d0 | 2291 | static void __exit jbd2_remove_debugfs_entry(void) |
470decc6 | 2292 | { |
6f38c74f JS |
2293 | debugfs_remove(jbd2_debug); |
2294 | debugfs_remove(jbd2_debugfs_dir); | |
470decc6 DK |
2295 | } |
2296 | ||
0f49d5d0 | 2297 | #else |
470decc6 | 2298 | |
0f49d5d0 | 2299 | static void __init jbd2_create_debugfs_entry(void) |
470decc6 | 2300 | { |
470decc6 DK |
2301 | } |
2302 | ||
0f49d5d0 | 2303 | static void __exit jbd2_remove_debugfs_entry(void) |
470decc6 | 2304 | { |
470decc6 DK |
2305 | } |
2306 | ||
470decc6 DK |
2307 | #endif |
2308 | ||
8e85fb3f JL |
2309 | #ifdef CONFIG_PROC_FS |
2310 | ||
2311 | #define JBD2_STATS_PROC_NAME "fs/jbd2" | |
2312 | ||
2313 | static void __init jbd2_create_jbd_stats_proc_entry(void) | |
2314 | { | |
2315 | proc_jbd2_stats = proc_mkdir(JBD2_STATS_PROC_NAME, NULL); | |
2316 | } | |
2317 | ||
2318 | static void __exit jbd2_remove_jbd_stats_proc_entry(void) | |
2319 | { | |
2320 | if (proc_jbd2_stats) | |
2321 | remove_proc_entry(JBD2_STATS_PROC_NAME, NULL); | |
2322 | } | |
2323 | ||
2324 | #else | |
2325 | ||
2326 | #define jbd2_create_jbd_stats_proc_entry() do {} while (0) | |
2327 | #define jbd2_remove_jbd_stats_proc_entry() do {} while (0) | |
2328 | ||
2329 | #endif | |
2330 | ||
e18b890b | 2331 | struct kmem_cache *jbd2_handle_cache; |
470decc6 DK |
2332 | |
2333 | static int __init journal_init_handle_cache(void) | |
2334 | { | |
a920e941 | 2335 | jbd2_handle_cache = kmem_cache_create("jbd2_journal_handle", |
470decc6 DK |
2336 | sizeof(handle_t), |
2337 | 0, /* offset */ | |
77160957 | 2338 | SLAB_TEMPORARY, /* flags */ |
20c2df83 | 2339 | NULL); /* ctor */ |
f7f4bccb | 2340 | if (jbd2_handle_cache == NULL) { |
470decc6 DK |
2341 | printk(KERN_EMERG "JBD: failed to create handle cache\n"); |
2342 | return -ENOMEM; | |
2343 | } | |
2344 | return 0; | |
2345 | } | |
2346 | ||
f7f4bccb | 2347 | static void jbd2_journal_destroy_handle_cache(void) |
470decc6 | 2348 | { |
f7f4bccb MC |
2349 | if (jbd2_handle_cache) |
2350 | kmem_cache_destroy(jbd2_handle_cache); | |
470decc6 DK |
2351 | } |
2352 | ||
2353 | /* | |
2354 | * Module startup and shutdown | |
2355 | */ | |
2356 | ||
2357 | static int __init journal_init_caches(void) | |
2358 | { | |
2359 | int ret; | |
2360 | ||
f7f4bccb | 2361 | ret = jbd2_journal_init_revoke_caches(); |
470decc6 | 2362 | if (ret == 0) |
f7f4bccb | 2363 | ret = journal_init_jbd2_journal_head_cache(); |
470decc6 DK |
2364 | if (ret == 0) |
2365 | ret = journal_init_handle_cache(); | |
2366 | return ret; | |
2367 | } | |
2368 | ||
f7f4bccb | 2369 | static void jbd2_journal_destroy_caches(void) |
470decc6 | 2370 | { |
f7f4bccb MC |
2371 | jbd2_journal_destroy_revoke_caches(); |
2372 | jbd2_journal_destroy_jbd2_journal_head_cache(); | |
2373 | jbd2_journal_destroy_handle_cache(); | |
470decc6 DK |
2374 | } |
2375 | ||
2376 | static int __init journal_init(void) | |
2377 | { | |
2378 | int ret; | |
2379 | ||
2380 | BUILD_BUG_ON(sizeof(struct journal_superblock_s) != 1024); | |
2381 | ||
2382 | ret = journal_init_caches(); | |
620de4e1 DG |
2383 | if (ret == 0) { |
2384 | jbd2_create_debugfs_entry(); | |
2385 | jbd2_create_jbd_stats_proc_entry(); | |
2386 | } else { | |
f7f4bccb | 2387 | jbd2_journal_destroy_caches(); |
620de4e1 | 2388 | } |
470decc6 DK |
2389 | return ret; |
2390 | } | |
2391 | ||
2392 | static void __exit journal_exit(void) | |
2393 | { | |
e23291b9 | 2394 | #ifdef CONFIG_JBD2_DEBUG |
470decc6 DK |
2395 | int n = atomic_read(&nr_journal_heads); |
2396 | if (n) | |
2397 | printk(KERN_EMERG "JBD: leaked %d journal_heads!\n", n); | |
2398 | #endif | |
0f49d5d0 | 2399 | jbd2_remove_debugfs_entry(); |
8e85fb3f | 2400 | jbd2_remove_jbd_stats_proc_entry(); |
f7f4bccb | 2401 | jbd2_journal_destroy_caches(); |
470decc6 DK |
2402 | } |
2403 | ||
2404 | MODULE_LICENSE("GPL"); | |
2405 | module_init(journal_init); | |
2406 | module_exit(journal_exit); | |
2407 |