Commit | Line | Data |
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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> |
c225aa57 | 40 | #include <linux/math64.h> |
879c5e6b | 41 | #include <linux/hash.h> |
d2eecb03 TT |
42 | #include <linux/log2.h> |
43 | #include <linux/vmalloc.h> | |
47def826 | 44 | #include <linux/backing-dev.h> |
39e3ac25 | 45 | #include <linux/bitops.h> |
879c5e6b TT |
46 | |
47 | #define CREATE_TRACE_POINTS | |
48 | #include <trace/events/jbd2.h> | |
470decc6 DK |
49 | |
50 | #include <asm/uaccess.h> | |
51 | #include <asm/page.h> | |
39e3ac25 | 52 | #include <asm/system.h> |
470decc6 | 53 | |
f7f4bccb MC |
54 | EXPORT_SYMBOL(jbd2_journal_extend); |
55 | EXPORT_SYMBOL(jbd2_journal_stop); | |
56 | EXPORT_SYMBOL(jbd2_journal_lock_updates); | |
57 | EXPORT_SYMBOL(jbd2_journal_unlock_updates); | |
58 | EXPORT_SYMBOL(jbd2_journal_get_write_access); | |
59 | EXPORT_SYMBOL(jbd2_journal_get_create_access); | |
60 | EXPORT_SYMBOL(jbd2_journal_get_undo_access); | |
e06c8227 | 61 | EXPORT_SYMBOL(jbd2_journal_set_triggers); |
f7f4bccb MC |
62 | EXPORT_SYMBOL(jbd2_journal_dirty_metadata); |
63 | EXPORT_SYMBOL(jbd2_journal_release_buffer); | |
64 | EXPORT_SYMBOL(jbd2_journal_forget); | |
470decc6 DK |
65 | #if 0 |
66 | EXPORT_SYMBOL(journal_sync_buffer); | |
67 | #endif | |
f7f4bccb MC |
68 | EXPORT_SYMBOL(jbd2_journal_flush); |
69 | EXPORT_SYMBOL(jbd2_journal_revoke); | |
70 | ||
71 | EXPORT_SYMBOL(jbd2_journal_init_dev); | |
72 | EXPORT_SYMBOL(jbd2_journal_init_inode); | |
73 | EXPORT_SYMBOL(jbd2_journal_update_format); | |
74 | EXPORT_SYMBOL(jbd2_journal_check_used_features); | |
75 | EXPORT_SYMBOL(jbd2_journal_check_available_features); | |
76 | EXPORT_SYMBOL(jbd2_journal_set_features); | |
f7f4bccb MC |
77 | EXPORT_SYMBOL(jbd2_journal_load); |
78 | EXPORT_SYMBOL(jbd2_journal_destroy); | |
f7f4bccb MC |
79 | EXPORT_SYMBOL(jbd2_journal_abort); |
80 | EXPORT_SYMBOL(jbd2_journal_errno); | |
81 | EXPORT_SYMBOL(jbd2_journal_ack_err); | |
82 | EXPORT_SYMBOL(jbd2_journal_clear_err); | |
83 | EXPORT_SYMBOL(jbd2_log_wait_commit); | |
3b799d15 | 84 | EXPORT_SYMBOL(jbd2_log_start_commit); |
f7f4bccb MC |
85 | EXPORT_SYMBOL(jbd2_journal_start_commit); |
86 | EXPORT_SYMBOL(jbd2_journal_force_commit_nested); | |
87 | EXPORT_SYMBOL(jbd2_journal_wipe); | |
88 | EXPORT_SYMBOL(jbd2_journal_blocks_per_page); | |
89 | EXPORT_SYMBOL(jbd2_journal_invalidatepage); | |
90 | EXPORT_SYMBOL(jbd2_journal_try_to_free_buffers); | |
91 | EXPORT_SYMBOL(jbd2_journal_force_commit); | |
c851ed54 JK |
92 | EXPORT_SYMBOL(jbd2_journal_file_inode); |
93 | EXPORT_SYMBOL(jbd2_journal_init_jbd_inode); | |
94 | EXPORT_SYMBOL(jbd2_journal_release_jbd_inode); | |
95 | EXPORT_SYMBOL(jbd2_journal_begin_ordered_truncate); | |
470decc6 DK |
96 | |
97 | static int journal_convert_superblock_v1(journal_t *, journal_superblock_t *); | |
98 | static void __journal_abort_soft (journal_t *journal, int errno); | |
d2eecb03 | 99 | static int jbd2_journal_create_slab(size_t slab_size); |
470decc6 DK |
100 | |
101 | /* | |
102 | * Helper function used to manage commit timeouts | |
103 | */ | |
104 | ||
105 | static void commit_timeout(unsigned long __data) | |
106 | { | |
107 | struct task_struct * p = (struct task_struct *) __data; | |
108 | ||
109 | wake_up_process(p); | |
110 | } | |
111 | ||
112 | /* | |
f7f4bccb | 113 | * kjournald2: The main thread function used to manage a logging device |
470decc6 DK |
114 | * journal. |
115 | * | |
116 | * This kernel thread is responsible for two things: | |
117 | * | |
118 | * 1) COMMIT: Every so often we need to commit the current state of the | |
119 | * filesystem to disk. The journal thread is responsible for writing | |
120 | * all of the metadata buffers to disk. | |
121 | * | |
122 | * 2) CHECKPOINT: We cannot reuse a used section of the log file until all | |
123 | * of the data in that part of the log has been rewritten elsewhere on | |
124 | * the disk. Flushing these old buffers to reclaim space in the log is | |
125 | * known as checkpointing, and this thread is responsible for that job. | |
126 | */ | |
127 | ||
f7f4bccb | 128 | static int kjournald2(void *arg) |
470decc6 DK |
129 | { |
130 | journal_t *journal = arg; | |
131 | transaction_t *transaction; | |
132 | ||
133 | /* | |
134 | * Set up an interval timer which can be used to trigger a commit wakeup | |
135 | * after the commit interval expires | |
136 | */ | |
137 | setup_timer(&journal->j_commit_timer, commit_timeout, | |
138 | (unsigned long)current); | |
139 | ||
140 | /* Record that the journal thread is running */ | |
141 | journal->j_task = current; | |
142 | wake_up(&journal->j_wait_done_commit); | |
143 | ||
470decc6 DK |
144 | /* |
145 | * And now, wait forever for commit wakeup events. | |
146 | */ | |
a931da6a | 147 | write_lock(&journal->j_state_lock); |
470decc6 DK |
148 | |
149 | loop: | |
f7f4bccb | 150 | if (journal->j_flags & JBD2_UNMOUNT) |
470decc6 DK |
151 | goto end_loop; |
152 | ||
153 | jbd_debug(1, "commit_sequence=%d, commit_request=%d\n", | |
154 | journal->j_commit_sequence, journal->j_commit_request); | |
155 | ||
156 | if (journal->j_commit_sequence != journal->j_commit_request) { | |
157 | jbd_debug(1, "OK, requests differ\n"); | |
a931da6a | 158 | write_unlock(&journal->j_state_lock); |
470decc6 | 159 | del_timer_sync(&journal->j_commit_timer); |
f7f4bccb | 160 | jbd2_journal_commit_transaction(journal); |
a931da6a | 161 | write_lock(&journal->j_state_lock); |
470decc6 DK |
162 | goto loop; |
163 | } | |
164 | ||
165 | wake_up(&journal->j_wait_done_commit); | |
166 | if (freezing(current)) { | |
167 | /* | |
168 | * The simpler the better. Flushing journal isn't a | |
169 | * good idea, because that depends on threads that may | |
170 | * be already stopped. | |
171 | */ | |
f7f4bccb | 172 | jbd_debug(1, "Now suspending kjournald2\n"); |
a931da6a | 173 | write_unlock(&journal->j_state_lock); |
470decc6 | 174 | refrigerator(); |
a931da6a | 175 | write_lock(&journal->j_state_lock); |
470decc6 DK |
176 | } else { |
177 | /* | |
178 | * We assume on resume that commits are already there, | |
179 | * so we don't sleep | |
180 | */ | |
181 | DEFINE_WAIT(wait); | |
182 | int should_sleep = 1; | |
183 | ||
184 | prepare_to_wait(&journal->j_wait_commit, &wait, | |
185 | TASK_INTERRUPTIBLE); | |
186 | if (journal->j_commit_sequence != journal->j_commit_request) | |
187 | should_sleep = 0; | |
188 | transaction = journal->j_running_transaction; | |
189 | if (transaction && time_after_eq(jiffies, | |
190 | transaction->t_expires)) | |
191 | should_sleep = 0; | |
f7f4bccb | 192 | if (journal->j_flags & JBD2_UNMOUNT) |
470decc6 DK |
193 | should_sleep = 0; |
194 | if (should_sleep) { | |
a931da6a | 195 | write_unlock(&journal->j_state_lock); |
470decc6 | 196 | schedule(); |
a931da6a | 197 | write_lock(&journal->j_state_lock); |
470decc6 DK |
198 | } |
199 | finish_wait(&journal->j_wait_commit, &wait); | |
200 | } | |
201 | ||
f7f4bccb | 202 | jbd_debug(1, "kjournald2 wakes\n"); |
470decc6 DK |
203 | |
204 | /* | |
205 | * Were we woken up by a commit wakeup event? | |
206 | */ | |
207 | transaction = journal->j_running_transaction; | |
208 | if (transaction && time_after_eq(jiffies, transaction->t_expires)) { | |
209 | journal->j_commit_request = transaction->t_tid; | |
210 | jbd_debug(1, "woke because of timeout\n"); | |
211 | } | |
212 | goto loop; | |
213 | ||
214 | end_loop: | |
a931da6a | 215 | write_unlock(&journal->j_state_lock); |
470decc6 DK |
216 | del_timer_sync(&journal->j_commit_timer); |
217 | journal->j_task = NULL; | |
218 | wake_up(&journal->j_wait_done_commit); | |
219 | jbd_debug(1, "Journal thread exiting.\n"); | |
220 | return 0; | |
221 | } | |
222 | ||
97f06784 | 223 | static int jbd2_journal_start_thread(journal_t *journal) |
470decc6 | 224 | { |
97f06784 PE |
225 | struct task_struct *t; |
226 | ||
90576c0b TT |
227 | t = kthread_run(kjournald2, journal, "jbd2/%s", |
228 | journal->j_devname); | |
97f06784 PE |
229 | if (IS_ERR(t)) |
230 | return PTR_ERR(t); | |
231 | ||
1076d17a | 232 | wait_event(journal->j_wait_done_commit, journal->j_task != NULL); |
97f06784 | 233 | return 0; |
470decc6 DK |
234 | } |
235 | ||
236 | static void journal_kill_thread(journal_t *journal) | |
237 | { | |
a931da6a | 238 | write_lock(&journal->j_state_lock); |
f7f4bccb | 239 | journal->j_flags |= JBD2_UNMOUNT; |
470decc6 DK |
240 | |
241 | while (journal->j_task) { | |
242 | wake_up(&journal->j_wait_commit); | |
a931da6a | 243 | write_unlock(&journal->j_state_lock); |
1076d17a | 244 | wait_event(journal->j_wait_done_commit, journal->j_task == NULL); |
a931da6a | 245 | write_lock(&journal->j_state_lock); |
470decc6 | 246 | } |
a931da6a | 247 | write_unlock(&journal->j_state_lock); |
470decc6 DK |
248 | } |
249 | ||
250 | /* | |
f7f4bccb | 251 | * jbd2_journal_write_metadata_buffer: write a metadata buffer to the journal. |
470decc6 DK |
252 | * |
253 | * Writes a metadata buffer to a given disk block. The actual IO is not | |
254 | * performed but a new buffer_head is constructed which labels the data | |
255 | * to be written with the correct destination disk block. | |
256 | * | |
257 | * Any magic-number escaping which needs to be done will cause a | |
258 | * copy-out here. If the buffer happens to start with the | |
f7f4bccb | 259 | * JBD2_MAGIC_NUMBER, then we can't write it to the log directly: the |
470decc6 DK |
260 | * magic number is only written to the log for descripter blocks. In |
261 | * this case, we copy the data and replace the first word with 0, and we | |
262 | * return a result code which indicates that this buffer needs to be | |
263 | * marked as an escaped buffer in the corresponding log descriptor | |
264 | * block. The missing word can then be restored when the block is read | |
265 | * during recovery. | |
266 | * | |
267 | * If the source buffer has already been modified by a new transaction | |
268 | * since we took the last commit snapshot, we use the frozen copy of | |
269 | * that data for IO. If we end up using the existing buffer_head's data | |
270 | * for the write, then we *have* to lock the buffer to prevent anyone | |
271 | * else from using and possibly modifying it while the IO is in | |
272 | * progress. | |
273 | * | |
274 | * The function returns a pointer to the buffer_heads to be used for IO. | |
275 | * | |
276 | * We assume that the journal has already been locked in this function. | |
277 | * | |
278 | * Return value: | |
279 | * <0: Error | |
280 | * >=0: Finished OK | |
281 | * | |
282 | * On success: | |
283 | * Bit 0 set == escape performed on the data | |
284 | * Bit 1 set == buffer copy-out performed (kfree the data after IO) | |
285 | */ | |
286 | ||
f7f4bccb | 287 | int jbd2_journal_write_metadata_buffer(transaction_t *transaction, |
470decc6 DK |
288 | struct journal_head *jh_in, |
289 | struct journal_head **jh_out, | |
18eba7aa | 290 | unsigned long long blocknr) |
470decc6 DK |
291 | { |
292 | int need_copy_out = 0; | |
293 | int done_copy_out = 0; | |
294 | int do_escape = 0; | |
295 | char *mapped_data; | |
296 | struct buffer_head *new_bh; | |
297 | struct journal_head *new_jh; | |
298 | struct page *new_page; | |
299 | unsigned int new_offset; | |
300 | struct buffer_head *bh_in = jh2bh(jh_in); | |
96577c43 | 301 | journal_t *journal = transaction->t_journal; |
470decc6 DK |
302 | |
303 | /* | |
304 | * The buffer really shouldn't be locked: only the current committing | |
305 | * transaction is allowed to write it, so nobody else is allowed | |
306 | * to do any IO. | |
307 | * | |
308 | * akpm: except if we're journalling data, and write() output is | |
309 | * also part of a shared mapping, and another thread has | |
310 | * decided to launch a writepage() against this buffer. | |
311 | */ | |
312 | J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in)); | |
313 | ||
47def826 TT |
314 | retry_alloc: |
315 | new_bh = alloc_buffer_head(GFP_NOFS); | |
316 | if (!new_bh) { | |
317 | /* | |
318 | * Failure is not an option, but __GFP_NOFAIL is going | |
319 | * away; so we retry ourselves here. | |
320 | */ | |
321 | congestion_wait(BLK_RW_ASYNC, HZ/50); | |
322 | goto retry_alloc; | |
323 | } | |
324 | ||
96577c43 | 325 | /* keep subsequent assertions sane */ |
326 | new_bh->b_state = 0; | |
327 | init_buffer(new_bh, NULL, NULL); | |
328 | atomic_set(&new_bh->b_count, 1); | |
329 | new_jh = jbd2_journal_add_journal_head(new_bh); /* This sleeps */ | |
470decc6 DK |
330 | |
331 | /* | |
332 | * If a new transaction has already done a buffer copy-out, then | |
333 | * we use that version of the data for the commit. | |
334 | */ | |
335 | jbd_lock_bh_state(bh_in); | |
336 | repeat: | |
337 | if (jh_in->b_frozen_data) { | |
338 | done_copy_out = 1; | |
339 | new_page = virt_to_page(jh_in->b_frozen_data); | |
340 | new_offset = offset_in_page(jh_in->b_frozen_data); | |
341 | } else { | |
342 | new_page = jh2bh(jh_in)->b_page; | |
343 | new_offset = offset_in_page(jh2bh(jh_in)->b_data); | |
344 | } | |
345 | ||
346 | mapped_data = kmap_atomic(new_page, KM_USER0); | |
e06c8227 | 347 | /* |
13ceef09 JK |
348 | * Fire data frozen trigger if data already wasn't frozen. Do this |
349 | * before checking for escaping, as the trigger may modify the magic | |
350 | * offset. If a copy-out happens afterwards, it will have the correct | |
351 | * data in the buffer. | |
e06c8227 | 352 | */ |
13ceef09 JK |
353 | if (!done_copy_out) |
354 | jbd2_buffer_frozen_trigger(jh_in, mapped_data + new_offset, | |
355 | jh_in->b_triggers); | |
e06c8227 | 356 | |
470decc6 DK |
357 | /* |
358 | * Check for escaping | |
359 | */ | |
360 | if (*((__be32 *)(mapped_data + new_offset)) == | |
f7f4bccb | 361 | cpu_to_be32(JBD2_MAGIC_NUMBER)) { |
470decc6 DK |
362 | need_copy_out = 1; |
363 | do_escape = 1; | |
364 | } | |
365 | kunmap_atomic(mapped_data, KM_USER0); | |
366 | ||
367 | /* | |
368 | * Do we need to do a data copy? | |
369 | */ | |
370 | if (need_copy_out && !done_copy_out) { | |
371 | char *tmp; | |
372 | ||
373 | jbd_unlock_bh_state(bh_in); | |
af1e76d6 | 374 | tmp = jbd2_alloc(bh_in->b_size, GFP_NOFS); |
e6ec116b TT |
375 | if (!tmp) { |
376 | jbd2_journal_put_journal_head(new_jh); | |
377 | return -ENOMEM; | |
378 | } | |
470decc6 DK |
379 | jbd_lock_bh_state(bh_in); |
380 | if (jh_in->b_frozen_data) { | |
af1e76d6 | 381 | jbd2_free(tmp, bh_in->b_size); |
470decc6 DK |
382 | goto repeat; |
383 | } | |
384 | ||
385 | jh_in->b_frozen_data = tmp; | |
386 | mapped_data = kmap_atomic(new_page, KM_USER0); | |
387 | memcpy(tmp, mapped_data + new_offset, jh2bh(jh_in)->b_size); | |
388 | kunmap_atomic(mapped_data, KM_USER0); | |
389 | ||
390 | new_page = virt_to_page(tmp); | |
391 | new_offset = offset_in_page(tmp); | |
392 | done_copy_out = 1; | |
e06c8227 JB |
393 | |
394 | /* | |
395 | * This isn't strictly necessary, as we're using frozen | |
396 | * data for the escaping, but it keeps consistency with | |
397 | * b_frozen_data usage. | |
398 | */ | |
399 | jh_in->b_frozen_triggers = jh_in->b_triggers; | |
470decc6 DK |
400 | } |
401 | ||
402 | /* | |
403 | * Did we need to do an escaping? Now we've done all the | |
404 | * copying, we can finally do so. | |
405 | */ | |
406 | if (do_escape) { | |
407 | mapped_data = kmap_atomic(new_page, KM_USER0); | |
408 | *((unsigned int *)(mapped_data + new_offset)) = 0; | |
409 | kunmap_atomic(mapped_data, KM_USER0); | |
410 | } | |
411 | ||
470decc6 DK |
412 | set_bh_page(new_bh, new_page, new_offset); |
413 | new_jh->b_transaction = NULL; | |
414 | new_bh->b_size = jh2bh(jh_in)->b_size; | |
415 | new_bh->b_bdev = transaction->t_journal->j_dev; | |
416 | new_bh->b_blocknr = blocknr; | |
417 | set_buffer_mapped(new_bh); | |
418 | set_buffer_dirty(new_bh); | |
419 | ||
420 | *jh_out = new_jh; | |
421 | ||
422 | /* | |
423 | * The to-be-written buffer needs to get moved to the io queue, | |
424 | * and the original buffer whose contents we are shadowing or | |
425 | * copying is moved to the transaction's shadow queue. | |
426 | */ | |
427 | JBUFFER_TRACE(jh_in, "file as BJ_Shadow"); | |
96577c43 | 428 | spin_lock(&journal->j_list_lock); |
429 | __jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow); | |
430 | spin_unlock(&journal->j_list_lock); | |
431 | jbd_unlock_bh_state(bh_in); | |
432 | ||
470decc6 | 433 | JBUFFER_TRACE(new_jh, "file as BJ_IO"); |
f7f4bccb | 434 | jbd2_journal_file_buffer(new_jh, transaction, BJ_IO); |
470decc6 DK |
435 | |
436 | return do_escape | (done_copy_out << 1); | |
437 | } | |
438 | ||
439 | /* | |
440 | * Allocation code for the journal file. Manage the space left in the | |
441 | * journal, so that we can begin checkpointing when appropriate. | |
442 | */ | |
443 | ||
444 | /* | |
f7f4bccb | 445 | * __jbd2_log_space_left: Return the number of free blocks left in the journal. |
470decc6 DK |
446 | * |
447 | * Called with the journal already locked. | |
448 | * | |
449 | * Called under j_state_lock | |
450 | */ | |
451 | ||
f7f4bccb | 452 | int __jbd2_log_space_left(journal_t *journal) |
470decc6 DK |
453 | { |
454 | int left = journal->j_free; | |
455 | ||
a931da6a | 456 | /* assert_spin_locked(&journal->j_state_lock); */ |
470decc6 DK |
457 | |
458 | /* | |
459 | * Be pessimistic here about the number of those free blocks which | |
460 | * might be required for log descriptor control blocks. | |
461 | */ | |
462 | ||
463 | #define MIN_LOG_RESERVED_BLOCKS 32 /* Allow for rounding errors */ | |
464 | ||
465 | left -= MIN_LOG_RESERVED_BLOCKS; | |
466 | ||
467 | if (left <= 0) | |
468 | return 0; | |
469 | left -= (left >> 3); | |
470 | return left; | |
471 | } | |
472 | ||
473 | /* | |
c88ccea3 | 474 | * Called under j_state_lock. Returns true if a transaction commit was started. |
470decc6 | 475 | */ |
f7f4bccb | 476 | int __jbd2_log_start_commit(journal_t *journal, tid_t target) |
470decc6 DK |
477 | { |
478 | /* | |
479 | * Are we already doing a recent enough commit? | |
480 | */ | |
481 | if (!tid_geq(journal->j_commit_request, target)) { | |
482 | /* | |
483 | * We want a new commit: OK, mark the request and wakup the | |
484 | * commit thread. We do _not_ do the commit ourselves. | |
485 | */ | |
486 | ||
487 | journal->j_commit_request = target; | |
488 | jbd_debug(1, "JBD: requesting commit %d/%d\n", | |
489 | journal->j_commit_request, | |
490 | journal->j_commit_sequence); | |
491 | wake_up(&journal->j_wait_commit); | |
492 | return 1; | |
493 | } | |
494 | return 0; | |
495 | } | |
496 | ||
f7f4bccb | 497 | int jbd2_log_start_commit(journal_t *journal, tid_t tid) |
470decc6 DK |
498 | { |
499 | int ret; | |
500 | ||
a931da6a | 501 | write_lock(&journal->j_state_lock); |
f7f4bccb | 502 | ret = __jbd2_log_start_commit(journal, tid); |
a931da6a | 503 | write_unlock(&journal->j_state_lock); |
470decc6 DK |
504 | return ret; |
505 | } | |
506 | ||
507 | /* | |
508 | * Force and wait upon a commit if the calling process is not within | |
509 | * transaction. This is used for forcing out undo-protected data which contains | |
510 | * bitmaps, when the fs is running out of space. | |
511 | * | |
512 | * We can only force the running transaction if we don't have an active handle; | |
513 | * otherwise, we will deadlock. | |
514 | * | |
515 | * Returns true if a transaction was started. | |
516 | */ | |
f7f4bccb | 517 | int jbd2_journal_force_commit_nested(journal_t *journal) |
470decc6 DK |
518 | { |
519 | transaction_t *transaction = NULL; | |
520 | tid_t tid; | |
521 | ||
a931da6a | 522 | read_lock(&journal->j_state_lock); |
470decc6 DK |
523 | if (journal->j_running_transaction && !current->journal_info) { |
524 | transaction = journal->j_running_transaction; | |
f7f4bccb | 525 | __jbd2_log_start_commit(journal, transaction->t_tid); |
470decc6 DK |
526 | } else if (journal->j_committing_transaction) |
527 | transaction = journal->j_committing_transaction; | |
528 | ||
529 | if (!transaction) { | |
a931da6a | 530 | read_unlock(&journal->j_state_lock); |
470decc6 DK |
531 | return 0; /* Nothing to retry */ |
532 | } | |
533 | ||
534 | tid = transaction->t_tid; | |
a931da6a | 535 | read_unlock(&journal->j_state_lock); |
f7f4bccb | 536 | jbd2_log_wait_commit(journal, tid); |
470decc6 DK |
537 | return 1; |
538 | } | |
539 | ||
540 | /* | |
541 | * Start a commit of the current running transaction (if any). Returns true | |
c88ccea3 JK |
542 | * if a transaction is going to be committed (or is currently already |
543 | * committing), and fills its tid in at *ptid | |
470decc6 | 544 | */ |
f7f4bccb | 545 | int jbd2_journal_start_commit(journal_t *journal, tid_t *ptid) |
470decc6 DK |
546 | { |
547 | int ret = 0; | |
548 | ||
a931da6a | 549 | write_lock(&journal->j_state_lock); |
470decc6 DK |
550 | if (journal->j_running_transaction) { |
551 | tid_t tid = journal->j_running_transaction->t_tid; | |
552 | ||
c88ccea3 JK |
553 | __jbd2_log_start_commit(journal, tid); |
554 | /* There's a running transaction and we've just made sure | |
555 | * it's commit has been scheduled. */ | |
556 | if (ptid) | |
470decc6 | 557 | *ptid = tid; |
c88ccea3 JK |
558 | ret = 1; |
559 | } else if (journal->j_committing_transaction) { | |
470decc6 DK |
560 | /* |
561 | * If ext3_write_super() recently started a commit, then we | |
562 | * have to wait for completion of that transaction | |
563 | */ | |
c88ccea3 JK |
564 | if (ptid) |
565 | *ptid = journal->j_committing_transaction->t_tid; | |
470decc6 DK |
566 | ret = 1; |
567 | } | |
a931da6a | 568 | write_unlock(&journal->j_state_lock); |
470decc6 DK |
569 | return ret; |
570 | } | |
571 | ||
572 | /* | |
573 | * Wait for a specified commit to complete. | |
574 | * The caller may not hold the journal lock. | |
575 | */ | |
f7f4bccb | 576 | int jbd2_log_wait_commit(journal_t *journal, tid_t tid) |
470decc6 DK |
577 | { |
578 | int err = 0; | |
579 | ||
a931da6a | 580 | read_lock(&journal->j_state_lock); |
e23291b9 | 581 | #ifdef CONFIG_JBD2_DEBUG |
470decc6 DK |
582 | if (!tid_geq(journal->j_commit_request, tid)) { |
583 | printk(KERN_EMERG | |
584 | "%s: error: j_commit_request=%d, tid=%d\n", | |
329d291f | 585 | __func__, journal->j_commit_request, tid); |
470decc6 | 586 | } |
470decc6 | 587 | #endif |
470decc6 DK |
588 | while (tid_gt(tid, journal->j_commit_sequence)) { |
589 | jbd_debug(1, "JBD: want %d, j_commit_sequence=%d\n", | |
590 | tid, journal->j_commit_sequence); | |
591 | wake_up(&journal->j_wait_commit); | |
a931da6a | 592 | read_unlock(&journal->j_state_lock); |
470decc6 DK |
593 | wait_event(journal->j_wait_done_commit, |
594 | !tid_gt(tid, journal->j_commit_sequence)); | |
a931da6a | 595 | read_lock(&journal->j_state_lock); |
470decc6 | 596 | } |
a931da6a | 597 | read_unlock(&journal->j_state_lock); |
470decc6 DK |
598 | |
599 | if (unlikely(is_journal_aborted(journal))) { | |
600 | printk(KERN_EMERG "journal commit I/O error\n"); | |
601 | err = -EIO; | |
602 | } | |
603 | return err; | |
604 | } | |
605 | ||
606 | /* | |
607 | * Log buffer allocation routines: | |
608 | */ | |
609 | ||
18eba7aa | 610 | int jbd2_journal_next_log_block(journal_t *journal, unsigned long long *retp) |
470decc6 DK |
611 | { |
612 | unsigned long blocknr; | |
613 | ||
a931da6a | 614 | write_lock(&journal->j_state_lock); |
470decc6 DK |
615 | J_ASSERT(journal->j_free > 1); |
616 | ||
617 | blocknr = journal->j_head; | |
618 | journal->j_head++; | |
619 | journal->j_free--; | |
620 | if (journal->j_head == journal->j_last) | |
621 | journal->j_head = journal->j_first; | |
a931da6a | 622 | write_unlock(&journal->j_state_lock); |
f7f4bccb | 623 | return jbd2_journal_bmap(journal, blocknr, retp); |
470decc6 DK |
624 | } |
625 | ||
626 | /* | |
627 | * Conversion of logical to physical block numbers for the journal | |
628 | * | |
629 | * On external journals the journal blocks are identity-mapped, so | |
630 | * this is a no-op. If needed, we can use j_blk_offset - everything is | |
631 | * ready. | |
632 | */ | |
f7f4bccb | 633 | int jbd2_journal_bmap(journal_t *journal, unsigned long blocknr, |
18eba7aa | 634 | unsigned long long *retp) |
470decc6 DK |
635 | { |
636 | int err = 0; | |
18eba7aa | 637 | unsigned long long ret; |
470decc6 DK |
638 | |
639 | if (journal->j_inode) { | |
640 | ret = bmap(journal->j_inode, blocknr); | |
641 | if (ret) | |
642 | *retp = ret; | |
643 | else { | |
470decc6 DK |
644 | printk(KERN_ALERT "%s: journal block not found " |
645 | "at offset %lu on %s\n", | |
05496769 | 646 | __func__, blocknr, journal->j_devname); |
470decc6 DK |
647 | err = -EIO; |
648 | __journal_abort_soft(journal, err); | |
649 | } | |
650 | } else { | |
651 | *retp = blocknr; /* +journal->j_blk_offset */ | |
652 | } | |
653 | return err; | |
654 | } | |
655 | ||
656 | /* | |
657 | * We play buffer_head aliasing tricks to write data/metadata blocks to | |
658 | * the journal without copying their contents, but for journal | |
659 | * descriptor blocks we do need to generate bona fide buffers. | |
660 | * | |
f7f4bccb | 661 | * After the caller of jbd2_journal_get_descriptor_buffer() has finished modifying |
470decc6 DK |
662 | * the buffer's contents they really should run flush_dcache_page(bh->b_page). |
663 | * But we don't bother doing that, so there will be coherency problems with | |
664 | * mmaps of blockdevs which hold live JBD-controlled filesystems. | |
665 | */ | |
f7f4bccb | 666 | struct journal_head *jbd2_journal_get_descriptor_buffer(journal_t *journal) |
470decc6 DK |
667 | { |
668 | struct buffer_head *bh; | |
18eba7aa | 669 | unsigned long long blocknr; |
470decc6 DK |
670 | int err; |
671 | ||
f7f4bccb | 672 | err = jbd2_journal_next_log_block(journal, &blocknr); |
470decc6 DK |
673 | |
674 | if (err) | |
675 | return NULL; | |
676 | ||
677 | bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); | |
4b905671 JK |
678 | if (!bh) |
679 | return NULL; | |
470decc6 DK |
680 | lock_buffer(bh); |
681 | memset(bh->b_data, 0, journal->j_blocksize); | |
682 | set_buffer_uptodate(bh); | |
683 | unlock_buffer(bh); | |
684 | BUFFER_TRACE(bh, "return this buffer"); | |
f7f4bccb | 685 | return jbd2_journal_add_journal_head(bh); |
470decc6 DK |
686 | } |
687 | ||
8e85fb3f JL |
688 | struct jbd2_stats_proc_session { |
689 | journal_t *journal; | |
690 | struct transaction_stats_s *stats; | |
691 | int start; | |
692 | int max; | |
693 | }; | |
694 | ||
8e85fb3f JL |
695 | static void *jbd2_seq_info_start(struct seq_file *seq, loff_t *pos) |
696 | { | |
697 | return *pos ? NULL : SEQ_START_TOKEN; | |
698 | } | |
699 | ||
700 | static void *jbd2_seq_info_next(struct seq_file *seq, void *v, loff_t *pos) | |
701 | { | |
702 | return NULL; | |
703 | } | |
704 | ||
705 | static int jbd2_seq_info_show(struct seq_file *seq, void *v) | |
706 | { | |
707 | struct jbd2_stats_proc_session *s = seq->private; | |
708 | ||
709 | if (v != SEQ_START_TOKEN) | |
710 | return 0; | |
bf699327 | 711 | seq_printf(seq, "%lu transaction, each up to %u blocks\n", |
8e85fb3f JL |
712 | s->stats->ts_tid, |
713 | s->journal->j_max_transaction_buffers); | |
714 | if (s->stats->ts_tid == 0) | |
715 | return 0; | |
716 | seq_printf(seq, "average: \n %ums waiting for transaction\n", | |
bf699327 | 717 | jiffies_to_msecs(s->stats->run.rs_wait / s->stats->ts_tid)); |
8e85fb3f | 718 | seq_printf(seq, " %ums running transaction\n", |
bf699327 | 719 | jiffies_to_msecs(s->stats->run.rs_running / s->stats->ts_tid)); |
8e85fb3f | 720 | seq_printf(seq, " %ums transaction was being locked\n", |
bf699327 | 721 | jiffies_to_msecs(s->stats->run.rs_locked / s->stats->ts_tid)); |
8e85fb3f | 722 | seq_printf(seq, " %ums flushing data (in ordered mode)\n", |
bf699327 | 723 | jiffies_to_msecs(s->stats->run.rs_flushing / s->stats->ts_tid)); |
8e85fb3f | 724 | seq_printf(seq, " %ums logging transaction\n", |
bf699327 | 725 | jiffies_to_msecs(s->stats->run.rs_logging / s->stats->ts_tid)); |
c225aa57 SHT |
726 | seq_printf(seq, " %lluus average transaction commit time\n", |
727 | div_u64(s->journal->j_average_commit_time, 1000)); | |
8e85fb3f | 728 | seq_printf(seq, " %lu handles per transaction\n", |
bf699327 | 729 | s->stats->run.rs_handle_count / s->stats->ts_tid); |
8e85fb3f | 730 | seq_printf(seq, " %lu blocks per transaction\n", |
bf699327 | 731 | s->stats->run.rs_blocks / s->stats->ts_tid); |
8e85fb3f | 732 | seq_printf(seq, " %lu logged blocks per transaction\n", |
bf699327 | 733 | s->stats->run.rs_blocks_logged / s->stats->ts_tid); |
8e85fb3f JL |
734 | return 0; |
735 | } | |
736 | ||
737 | static void jbd2_seq_info_stop(struct seq_file *seq, void *v) | |
738 | { | |
739 | } | |
740 | ||
88e9d34c | 741 | static const struct seq_operations jbd2_seq_info_ops = { |
8e85fb3f JL |
742 | .start = jbd2_seq_info_start, |
743 | .next = jbd2_seq_info_next, | |
744 | .stop = jbd2_seq_info_stop, | |
745 | .show = jbd2_seq_info_show, | |
746 | }; | |
747 | ||
748 | static int jbd2_seq_info_open(struct inode *inode, struct file *file) | |
749 | { | |
750 | journal_t *journal = PDE(inode)->data; | |
751 | struct jbd2_stats_proc_session *s; | |
752 | int rc, size; | |
753 | ||
754 | s = kmalloc(sizeof(*s), GFP_KERNEL); | |
755 | if (s == NULL) | |
756 | return -ENOMEM; | |
757 | size = sizeof(struct transaction_stats_s); | |
758 | s->stats = kmalloc(size, GFP_KERNEL); | |
759 | if (s->stats == NULL) { | |
760 | kfree(s); | |
761 | return -ENOMEM; | |
762 | } | |
763 | spin_lock(&journal->j_history_lock); | |
764 | memcpy(s->stats, &journal->j_stats, size); | |
765 | s->journal = journal; | |
766 | spin_unlock(&journal->j_history_lock); | |
767 | ||
768 | rc = seq_open(file, &jbd2_seq_info_ops); | |
769 | if (rc == 0) { | |
770 | struct seq_file *m = file->private_data; | |
771 | m->private = s; | |
772 | } else { | |
773 | kfree(s->stats); | |
774 | kfree(s); | |
775 | } | |
776 | return rc; | |
777 | ||
778 | } | |
779 | ||
780 | static int jbd2_seq_info_release(struct inode *inode, struct file *file) | |
781 | { | |
782 | struct seq_file *seq = file->private_data; | |
783 | struct jbd2_stats_proc_session *s = seq->private; | |
784 | kfree(s->stats); | |
785 | kfree(s); | |
786 | return seq_release(inode, file); | |
787 | } | |
788 | ||
828c0950 | 789 | static const struct file_operations jbd2_seq_info_fops = { |
8e85fb3f JL |
790 | .owner = THIS_MODULE, |
791 | .open = jbd2_seq_info_open, | |
792 | .read = seq_read, | |
793 | .llseek = seq_lseek, | |
794 | .release = jbd2_seq_info_release, | |
795 | }; | |
796 | ||
797 | static struct proc_dir_entry *proc_jbd2_stats; | |
798 | ||
799 | static void jbd2_stats_proc_init(journal_t *journal) | |
800 | { | |
05496769 | 801 | journal->j_proc_entry = proc_mkdir(journal->j_devname, proc_jbd2_stats); |
8e85fb3f | 802 | if (journal->j_proc_entry) { |
79da3664 DL |
803 | proc_create_data("info", S_IRUGO, journal->j_proc_entry, |
804 | &jbd2_seq_info_fops, journal); | |
8e85fb3f JL |
805 | } |
806 | } | |
807 | ||
808 | static void jbd2_stats_proc_exit(journal_t *journal) | |
809 | { | |
8e85fb3f | 810 | remove_proc_entry("info", journal->j_proc_entry); |
05496769 | 811 | remove_proc_entry(journal->j_devname, proc_jbd2_stats); |
8e85fb3f JL |
812 | } |
813 | ||
470decc6 DK |
814 | /* |
815 | * Management for journal control blocks: functions to create and | |
816 | * destroy journal_t structures, and to initialise and read existing | |
817 | * journal blocks from disk. */ | |
818 | ||
819 | /* First: create and setup a journal_t object in memory. We initialise | |
820 | * very few fields yet: that has to wait until we have created the | |
821 | * journal structures from from scratch, or loaded them from disk. */ | |
822 | ||
823 | static journal_t * journal_init_common (void) | |
824 | { | |
825 | journal_t *journal; | |
826 | int err; | |
827 | ||
3ebfdf88 | 828 | journal = kzalloc(sizeof(*journal), GFP_KERNEL); |
470decc6 DK |
829 | if (!journal) |
830 | goto fail; | |
470decc6 DK |
831 | |
832 | init_waitqueue_head(&journal->j_wait_transaction_locked); | |
833 | init_waitqueue_head(&journal->j_wait_logspace); | |
834 | init_waitqueue_head(&journal->j_wait_done_commit); | |
835 | init_waitqueue_head(&journal->j_wait_checkpoint); | |
836 | init_waitqueue_head(&journal->j_wait_commit); | |
837 | init_waitqueue_head(&journal->j_wait_updates); | |
838 | mutex_init(&journal->j_barrier); | |
839 | mutex_init(&journal->j_checkpoint_mutex); | |
840 | spin_lock_init(&journal->j_revoke_lock); | |
841 | spin_lock_init(&journal->j_list_lock); | |
a931da6a | 842 | rwlock_init(&journal->j_state_lock); |
470decc6 | 843 | |
cd02ff0b | 844 | journal->j_commit_interval = (HZ * JBD2_DEFAULT_MAX_COMMIT_AGE); |
30773840 TT |
845 | journal->j_min_batch_time = 0; |
846 | journal->j_max_batch_time = 15000; /* 15ms */ | |
470decc6 DK |
847 | |
848 | /* The journal is marked for error until we succeed with recovery! */ | |
f7f4bccb | 849 | journal->j_flags = JBD2_ABORT; |
470decc6 DK |
850 | |
851 | /* Set up a default-sized revoke table for the new mount. */ | |
f7f4bccb | 852 | err = jbd2_journal_init_revoke(journal, JOURNAL_REVOKE_DEFAULT_HASH); |
470decc6 DK |
853 | if (err) { |
854 | kfree(journal); | |
855 | goto fail; | |
856 | } | |
8e85fb3f | 857 | |
bf699327 | 858 | spin_lock_init(&journal->j_history_lock); |
8e85fb3f | 859 | |
470decc6 DK |
860 | return journal; |
861 | fail: | |
862 | return NULL; | |
863 | } | |
864 | ||
f7f4bccb | 865 | /* jbd2_journal_init_dev and jbd2_journal_init_inode: |
470decc6 DK |
866 | * |
867 | * Create a journal structure assigned some fixed set of disk blocks to | |
868 | * the journal. We don't actually touch those disk blocks yet, but we | |
869 | * need to set up all of the mapping information to tell the journaling | |
870 | * system where the journal blocks are. | |
871 | * | |
872 | */ | |
873 | ||
874 | /** | |
5648ba5b | 875 | * journal_t * jbd2_journal_init_dev() - creates and initialises a journal structure |
470decc6 DK |
876 | * @bdev: Block device on which to create the journal |
877 | * @fs_dev: Device which hold journalled filesystem for this journal. | |
878 | * @start: Block nr Start of journal. | |
879 | * @len: Length of the journal in blocks. | |
880 | * @blocksize: blocksize of journalling device | |
5648ba5b RD |
881 | * |
882 | * Returns: a newly created journal_t * | |
470decc6 | 883 | * |
f7f4bccb | 884 | * jbd2_journal_init_dev creates a journal which maps a fixed contiguous |
470decc6 DK |
885 | * range of blocks on an arbitrary block device. |
886 | * | |
887 | */ | |
f7f4bccb | 888 | journal_t * jbd2_journal_init_dev(struct block_device *bdev, |
470decc6 | 889 | struct block_device *fs_dev, |
18eba7aa | 890 | unsigned long long start, int len, int blocksize) |
470decc6 DK |
891 | { |
892 | journal_t *journal = journal_init_common(); | |
893 | struct buffer_head *bh; | |
05496769 | 894 | char *p; |
470decc6 DK |
895 | int n; |
896 | ||
897 | if (!journal) | |
898 | return NULL; | |
899 | ||
900 | /* journal descriptor can store up to n blocks -bzzz */ | |
901 | journal->j_blocksize = blocksize; | |
4b905671 | 902 | jbd2_stats_proc_init(journal); |
470decc6 DK |
903 | n = journal->j_blocksize / sizeof(journal_block_tag_t); |
904 | journal->j_wbufsize = n; | |
905 | journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL); | |
906 | if (!journal->j_wbuf) { | |
907 | printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n", | |
329d291f | 908 | __func__); |
4b905671 | 909 | goto out_err; |
470decc6 DK |
910 | } |
911 | journal->j_dev = bdev; | |
912 | journal->j_fs_dev = fs_dev; | |
913 | journal->j_blk_offset = start; | |
914 | journal->j_maxlen = len; | |
05496769 TT |
915 | bdevname(journal->j_dev, journal->j_devname); |
916 | p = journal->j_devname; | |
917 | while ((p = strchr(p, '/'))) | |
918 | *p = '!'; | |
470decc6 DK |
919 | |
920 | bh = __getblk(journal->j_dev, start, journal->j_blocksize); | |
4b905671 JK |
921 | if (!bh) { |
922 | printk(KERN_ERR | |
923 | "%s: Cannot get buffer for journal superblock\n", | |
924 | __func__); | |
925 | goto out_err; | |
926 | } | |
470decc6 DK |
927 | journal->j_sb_buffer = bh; |
928 | journal->j_superblock = (journal_superblock_t *)bh->b_data; | |
4b905671 | 929 | |
470decc6 | 930 | return journal; |
4b905671 | 931 | out_err: |
7b02bec0 | 932 | kfree(journal->j_wbuf); |
4b905671 JK |
933 | jbd2_stats_proc_exit(journal); |
934 | kfree(journal); | |
935 | return NULL; | |
470decc6 DK |
936 | } |
937 | ||
938 | /** | |
f7f4bccb | 939 | * journal_t * jbd2_journal_init_inode () - creates a journal which maps to a inode. |
470decc6 DK |
940 | * @inode: An inode to create the journal in |
941 | * | |
f7f4bccb | 942 | * jbd2_journal_init_inode creates a journal which maps an on-disk inode as |
470decc6 DK |
943 | * the journal. The inode must exist already, must support bmap() and |
944 | * must have all data blocks preallocated. | |
945 | */ | |
f7f4bccb | 946 | journal_t * jbd2_journal_init_inode (struct inode *inode) |
470decc6 DK |
947 | { |
948 | struct buffer_head *bh; | |
949 | journal_t *journal = journal_init_common(); | |
05496769 | 950 | char *p; |
470decc6 DK |
951 | int err; |
952 | int n; | |
18eba7aa | 953 | unsigned long long blocknr; |
470decc6 DK |
954 | |
955 | if (!journal) | |
956 | return NULL; | |
957 | ||
958 | journal->j_dev = journal->j_fs_dev = inode->i_sb->s_bdev; | |
959 | journal->j_inode = inode; | |
05496769 TT |
960 | bdevname(journal->j_dev, journal->j_devname); |
961 | p = journal->j_devname; | |
962 | while ((p = strchr(p, '/'))) | |
963 | *p = '!'; | |
964 | p = journal->j_devname + strlen(journal->j_devname); | |
90576c0b | 965 | sprintf(p, "-%lu", journal->j_inode->i_ino); |
470decc6 DK |
966 | jbd_debug(1, |
967 | "journal %p: inode %s/%ld, size %Ld, bits %d, blksize %ld\n", | |
968 | journal, inode->i_sb->s_id, inode->i_ino, | |
969 | (long long) inode->i_size, | |
970 | inode->i_sb->s_blocksize_bits, inode->i_sb->s_blocksize); | |
971 | ||
972 | journal->j_maxlen = inode->i_size >> inode->i_sb->s_blocksize_bits; | |
973 | journal->j_blocksize = inode->i_sb->s_blocksize; | |
8e85fb3f | 974 | jbd2_stats_proc_init(journal); |
470decc6 DK |
975 | |
976 | /* journal descriptor can store up to n blocks -bzzz */ | |
977 | n = journal->j_blocksize / sizeof(journal_block_tag_t); | |
978 | journal->j_wbufsize = n; | |
979 | journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL); | |
980 | if (!journal->j_wbuf) { | |
981 | printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n", | |
329d291f | 982 | __func__); |
4b905671 | 983 | goto out_err; |
470decc6 DK |
984 | } |
985 | ||
f7f4bccb | 986 | err = jbd2_journal_bmap(journal, 0, &blocknr); |
470decc6 DK |
987 | /* If that failed, give up */ |
988 | if (err) { | |
989 | printk(KERN_ERR "%s: Cannnot locate journal superblock\n", | |
329d291f | 990 | __func__); |
4b905671 | 991 | goto out_err; |
470decc6 DK |
992 | } |
993 | ||
994 | bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); | |
4b905671 JK |
995 | if (!bh) { |
996 | printk(KERN_ERR | |
997 | "%s: Cannot get buffer for journal superblock\n", | |
998 | __func__); | |
999 | goto out_err; | |
1000 | } | |
470decc6 DK |
1001 | journal->j_sb_buffer = bh; |
1002 | journal->j_superblock = (journal_superblock_t *)bh->b_data; | |
1003 | ||
1004 | return journal; | |
4b905671 | 1005 | out_err: |
7b02bec0 | 1006 | kfree(journal->j_wbuf); |
4b905671 JK |
1007 | jbd2_stats_proc_exit(journal); |
1008 | kfree(journal); | |
1009 | return NULL; | |
470decc6 DK |
1010 | } |
1011 | ||
1012 | /* | |
1013 | * If the journal init or create aborts, we need to mark the journal | |
1014 | * superblock as being NULL to prevent the journal destroy from writing | |
1015 | * back a bogus superblock. | |
1016 | */ | |
1017 | static void journal_fail_superblock (journal_t *journal) | |
1018 | { | |
1019 | struct buffer_head *bh = journal->j_sb_buffer; | |
1020 | brelse(bh); | |
1021 | journal->j_sb_buffer = NULL; | |
1022 | } | |
1023 | ||
1024 | /* | |
1025 | * Given a journal_t structure, initialise the various fields for | |
1026 | * startup of a new journaling session. We use this both when creating | |
1027 | * a journal, and after recovering an old journal to reset it for | |
1028 | * subsequent use. | |
1029 | */ | |
1030 | ||
1031 | static int journal_reset(journal_t *journal) | |
1032 | { | |
1033 | journal_superblock_t *sb = journal->j_superblock; | |
18eba7aa | 1034 | unsigned long long first, last; |
470decc6 DK |
1035 | |
1036 | first = be32_to_cpu(sb->s_first); | |
1037 | last = be32_to_cpu(sb->s_maxlen); | |
f6f50e28 JK |
1038 | if (first + JBD2_MIN_JOURNAL_BLOCKS > last + 1) { |
1039 | printk(KERN_ERR "JBD: Journal too short (blocks %llu-%llu).\n", | |
1040 | first, last); | |
1041 | journal_fail_superblock(journal); | |
1042 | return -EINVAL; | |
1043 | } | |
470decc6 DK |
1044 | |
1045 | journal->j_first = first; | |
1046 | journal->j_last = last; | |
1047 | ||
1048 | journal->j_head = first; | |
1049 | journal->j_tail = first; | |
1050 | journal->j_free = last - first; | |
1051 | ||
1052 | journal->j_tail_sequence = journal->j_transaction_sequence; | |
1053 | journal->j_commit_sequence = journal->j_transaction_sequence - 1; | |
1054 | journal->j_commit_request = journal->j_commit_sequence; | |
1055 | ||
1056 | journal->j_max_transaction_buffers = journal->j_maxlen / 4; | |
1057 | ||
1058 | /* Add the dynamic fields and write it to disk. */ | |
f7f4bccb | 1059 | jbd2_journal_update_superblock(journal, 1); |
97f06784 | 1060 | return jbd2_journal_start_thread(journal); |
470decc6 DK |
1061 | } |
1062 | ||
470decc6 | 1063 | /** |
f7f4bccb | 1064 | * void jbd2_journal_update_superblock() - Update journal sb on disk. |
470decc6 DK |
1065 | * @journal: The journal to update. |
1066 | * @wait: Set to '0' if you don't want to wait for IO completion. | |
1067 | * | |
1068 | * Update a journal's dynamic superblock fields and write it to disk, | |
1069 | * optionally waiting for the IO to complete. | |
1070 | */ | |
f7f4bccb | 1071 | void jbd2_journal_update_superblock(journal_t *journal, int wait) |
470decc6 DK |
1072 | { |
1073 | journal_superblock_t *sb = journal->j_superblock; | |
1074 | struct buffer_head *bh = journal->j_sb_buffer; | |
1075 | ||
1076 | /* | |
1077 | * As a special case, if the on-disk copy is already marked as needing | |
1078 | * no recovery (s_start == 0) and there are no outstanding transactions | |
1079 | * in the filesystem, then we can safely defer the superblock update | |
f7f4bccb | 1080 | * until the next commit by setting JBD2_FLUSHED. This avoids |
470decc6 DK |
1081 | * attempting a write to a potential-readonly device. |
1082 | */ | |
1083 | if (sb->s_start == 0 && journal->j_tail_sequence == | |
1084 | journal->j_transaction_sequence) { | |
1085 | jbd_debug(1,"JBD: Skipping superblock update on recovered sb " | |
1086 | "(start %ld, seq %d, errno %d)\n", | |
1087 | journal->j_tail, journal->j_tail_sequence, | |
1088 | journal->j_errno); | |
1089 | goto out; | |
1090 | } | |
1091 | ||
914258bf TT |
1092 | if (buffer_write_io_error(bh)) { |
1093 | /* | |
1094 | * Oh, dear. A previous attempt to write the journal | |
1095 | * superblock failed. This could happen because the | |
1096 | * USB device was yanked out. Or it could happen to | |
1097 | * be a transient write error and maybe the block will | |
1098 | * be remapped. Nothing we can do but to retry the | |
1099 | * write and hope for the best. | |
1100 | */ | |
1101 | printk(KERN_ERR "JBD2: previous I/O error detected " | |
1102 | "for journal superblock update for %s.\n", | |
1103 | journal->j_devname); | |
1104 | clear_buffer_write_io_error(bh); | |
1105 | set_buffer_uptodate(bh); | |
1106 | } | |
1107 | ||
a931da6a | 1108 | read_lock(&journal->j_state_lock); |
470decc6 DK |
1109 | jbd_debug(1,"JBD: updating superblock (start %ld, seq %d, errno %d)\n", |
1110 | journal->j_tail, journal->j_tail_sequence, journal->j_errno); | |
1111 | ||
1112 | sb->s_sequence = cpu_to_be32(journal->j_tail_sequence); | |
1113 | sb->s_start = cpu_to_be32(journal->j_tail); | |
1114 | sb->s_errno = cpu_to_be32(journal->j_errno); | |
a931da6a | 1115 | read_unlock(&journal->j_state_lock); |
470decc6 DK |
1116 | |
1117 | BUFFER_TRACE(bh, "marking dirty"); | |
1118 | mark_buffer_dirty(bh); | |
914258bf | 1119 | if (wait) { |
470decc6 | 1120 | sync_dirty_buffer(bh); |
914258bf TT |
1121 | if (buffer_write_io_error(bh)) { |
1122 | printk(KERN_ERR "JBD2: I/O error detected " | |
1123 | "when updating journal superblock for %s.\n", | |
1124 | journal->j_devname); | |
1125 | clear_buffer_write_io_error(bh); | |
1126 | set_buffer_uptodate(bh); | |
1127 | } | |
1128 | } else | |
9cb569d6 | 1129 | write_dirty_buffer(bh, WRITE); |
470decc6 DK |
1130 | |
1131 | out: | |
1132 | /* If we have just flushed the log (by marking s_start==0), then | |
1133 | * any future commit will have to be careful to update the | |
1134 | * superblock again to re-record the true start of the log. */ | |
1135 | ||
a931da6a | 1136 | write_lock(&journal->j_state_lock); |
470decc6 | 1137 | if (sb->s_start) |
f7f4bccb | 1138 | journal->j_flags &= ~JBD2_FLUSHED; |
470decc6 | 1139 | else |
f7f4bccb | 1140 | journal->j_flags |= JBD2_FLUSHED; |
a931da6a | 1141 | write_unlock(&journal->j_state_lock); |
470decc6 DK |
1142 | } |
1143 | ||
1144 | /* | |
1145 | * Read the superblock for a given journal, performing initial | |
1146 | * validation of the format. | |
1147 | */ | |
1148 | ||
1149 | static int journal_get_superblock(journal_t *journal) | |
1150 | { | |
1151 | struct buffer_head *bh; | |
1152 | journal_superblock_t *sb; | |
1153 | int err = -EIO; | |
1154 | ||
1155 | bh = journal->j_sb_buffer; | |
1156 | ||
1157 | J_ASSERT(bh != NULL); | |
1158 | if (!buffer_uptodate(bh)) { | |
1159 | ll_rw_block(READ, 1, &bh); | |
1160 | wait_on_buffer(bh); | |
1161 | if (!buffer_uptodate(bh)) { | |
1162 | printk (KERN_ERR | |
1163 | "JBD: IO error reading journal superblock\n"); | |
1164 | goto out; | |
1165 | } | |
1166 | } | |
1167 | ||
1168 | sb = journal->j_superblock; | |
1169 | ||
1170 | err = -EINVAL; | |
1171 | ||
f7f4bccb | 1172 | if (sb->s_header.h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER) || |
470decc6 DK |
1173 | sb->s_blocksize != cpu_to_be32(journal->j_blocksize)) { |
1174 | printk(KERN_WARNING "JBD: no valid journal superblock found\n"); | |
1175 | goto out; | |
1176 | } | |
1177 | ||
1178 | switch(be32_to_cpu(sb->s_header.h_blocktype)) { | |
f7f4bccb | 1179 | case JBD2_SUPERBLOCK_V1: |
470decc6 DK |
1180 | journal->j_format_version = 1; |
1181 | break; | |
f7f4bccb | 1182 | case JBD2_SUPERBLOCK_V2: |
470decc6 DK |
1183 | journal->j_format_version = 2; |
1184 | break; | |
1185 | default: | |
1186 | printk(KERN_WARNING "JBD: unrecognised superblock format ID\n"); | |
1187 | goto out; | |
1188 | } | |
1189 | ||
1190 | if (be32_to_cpu(sb->s_maxlen) < journal->j_maxlen) | |
1191 | journal->j_maxlen = be32_to_cpu(sb->s_maxlen); | |
1192 | else if (be32_to_cpu(sb->s_maxlen) > journal->j_maxlen) { | |
1193 | printk (KERN_WARNING "JBD: journal file too short\n"); | |
1194 | goto out; | |
1195 | } | |
1196 | ||
1197 | return 0; | |
1198 | ||
1199 | out: | |
1200 | journal_fail_superblock(journal); | |
1201 | return err; | |
1202 | } | |
1203 | ||
1204 | /* | |
1205 | * Load the on-disk journal superblock and read the key fields into the | |
1206 | * journal_t. | |
1207 | */ | |
1208 | ||
1209 | static int load_superblock(journal_t *journal) | |
1210 | { | |
1211 | int err; | |
1212 | journal_superblock_t *sb; | |
1213 | ||
1214 | err = journal_get_superblock(journal); | |
1215 | if (err) | |
1216 | return err; | |
1217 | ||
1218 | sb = journal->j_superblock; | |
1219 | ||
1220 | journal->j_tail_sequence = be32_to_cpu(sb->s_sequence); | |
1221 | journal->j_tail = be32_to_cpu(sb->s_start); | |
1222 | journal->j_first = be32_to_cpu(sb->s_first); | |
1223 | journal->j_last = be32_to_cpu(sb->s_maxlen); | |
1224 | journal->j_errno = be32_to_cpu(sb->s_errno); | |
1225 | ||
1226 | return 0; | |
1227 | } | |
1228 | ||
1229 | ||
1230 | /** | |
f7f4bccb | 1231 | * int jbd2_journal_load() - Read journal from disk. |
470decc6 DK |
1232 | * @journal: Journal to act on. |
1233 | * | |
1234 | * Given a journal_t structure which tells us which disk blocks contain | |
1235 | * a journal, read the journal from disk to initialise the in-memory | |
1236 | * structures. | |
1237 | */ | |
f7f4bccb | 1238 | int jbd2_journal_load(journal_t *journal) |
470decc6 DK |
1239 | { |
1240 | int err; | |
1241 | journal_superblock_t *sb; | |
1242 | ||
1243 | err = load_superblock(journal); | |
1244 | if (err) | |
1245 | return err; | |
1246 | ||
1247 | sb = journal->j_superblock; | |
1248 | /* If this is a V2 superblock, then we have to check the | |
1249 | * features flags on it. */ | |
1250 | ||
1251 | if (journal->j_format_version >= 2) { | |
1252 | if ((sb->s_feature_ro_compat & | |
f7f4bccb | 1253 | ~cpu_to_be32(JBD2_KNOWN_ROCOMPAT_FEATURES)) || |
470decc6 | 1254 | (sb->s_feature_incompat & |
f7f4bccb | 1255 | ~cpu_to_be32(JBD2_KNOWN_INCOMPAT_FEATURES))) { |
470decc6 DK |
1256 | printk (KERN_WARNING |
1257 | "JBD: Unrecognised features on journal\n"); | |
1258 | return -EINVAL; | |
1259 | } | |
1260 | } | |
1261 | ||
d2eecb03 TT |
1262 | /* |
1263 | * Create a slab for this blocksize | |
1264 | */ | |
1265 | err = jbd2_journal_create_slab(be32_to_cpu(sb->s_blocksize)); | |
1266 | if (err) | |
1267 | return err; | |
1268 | ||
470decc6 DK |
1269 | /* Let the recovery code check whether it needs to recover any |
1270 | * data from the journal. */ | |
f7f4bccb | 1271 | if (jbd2_journal_recover(journal)) |
470decc6 DK |
1272 | goto recovery_error; |
1273 | ||
e6a47428 TT |
1274 | if (journal->j_failed_commit) { |
1275 | printk(KERN_ERR "JBD2: journal transaction %u on %s " | |
1276 | "is corrupt.\n", journal->j_failed_commit, | |
1277 | journal->j_devname); | |
1278 | return -EIO; | |
1279 | } | |
1280 | ||
470decc6 DK |
1281 | /* OK, we've finished with the dynamic journal bits: |
1282 | * reinitialise the dynamic contents of the superblock in memory | |
1283 | * and reset them on disk. */ | |
1284 | if (journal_reset(journal)) | |
1285 | goto recovery_error; | |
1286 | ||
f7f4bccb MC |
1287 | journal->j_flags &= ~JBD2_ABORT; |
1288 | journal->j_flags |= JBD2_LOADED; | |
470decc6 DK |
1289 | return 0; |
1290 | ||
1291 | recovery_error: | |
1292 | printk (KERN_WARNING "JBD: recovery failed\n"); | |
1293 | return -EIO; | |
1294 | } | |
1295 | ||
1296 | /** | |
f7f4bccb | 1297 | * void jbd2_journal_destroy() - Release a journal_t structure. |
470decc6 DK |
1298 | * @journal: Journal to act on. |
1299 | * | |
1300 | * Release a journal_t structure once it is no longer in use by the | |
1301 | * journaled object. | |
44519faf | 1302 | * Return <0 if we couldn't clean up the journal. |
470decc6 | 1303 | */ |
44519faf | 1304 | int jbd2_journal_destroy(journal_t *journal) |
470decc6 | 1305 | { |
44519faf HK |
1306 | int err = 0; |
1307 | ||
470decc6 DK |
1308 | /* Wait for the commit thread to wake up and die. */ |
1309 | journal_kill_thread(journal); | |
1310 | ||
1311 | /* Force a final log commit */ | |
1312 | if (journal->j_running_transaction) | |
f7f4bccb | 1313 | jbd2_journal_commit_transaction(journal); |
470decc6 DK |
1314 | |
1315 | /* Force any old transactions to disk */ | |
1316 | ||
1317 | /* Totally anal locking here... */ | |
1318 | spin_lock(&journal->j_list_lock); | |
1319 | while (journal->j_checkpoint_transactions != NULL) { | |
1320 | spin_unlock(&journal->j_list_lock); | |
1a0d3786 | 1321 | mutex_lock(&journal->j_checkpoint_mutex); |
f7f4bccb | 1322 | jbd2_log_do_checkpoint(journal); |
1a0d3786 | 1323 | mutex_unlock(&journal->j_checkpoint_mutex); |
470decc6 DK |
1324 | spin_lock(&journal->j_list_lock); |
1325 | } | |
1326 | ||
1327 | J_ASSERT(journal->j_running_transaction == NULL); | |
1328 | J_ASSERT(journal->j_committing_transaction == NULL); | |
1329 | J_ASSERT(journal->j_checkpoint_transactions == NULL); | |
1330 | spin_unlock(&journal->j_list_lock); | |
1331 | ||
470decc6 | 1332 | if (journal->j_sb_buffer) { |
44519faf HK |
1333 | if (!is_journal_aborted(journal)) { |
1334 | /* We can now mark the journal as empty. */ | |
1335 | journal->j_tail = 0; | |
1336 | journal->j_tail_sequence = | |
1337 | ++journal->j_transaction_sequence; | |
1338 | jbd2_journal_update_superblock(journal, 1); | |
1339 | } else { | |
1340 | err = -EIO; | |
1341 | } | |
470decc6 DK |
1342 | brelse(journal->j_sb_buffer); |
1343 | } | |
1344 | ||
8e85fb3f JL |
1345 | if (journal->j_proc_entry) |
1346 | jbd2_stats_proc_exit(journal); | |
470decc6 DK |
1347 | if (journal->j_inode) |
1348 | iput(journal->j_inode); | |
1349 | if (journal->j_revoke) | |
f7f4bccb | 1350 | jbd2_journal_destroy_revoke(journal); |
470decc6 DK |
1351 | kfree(journal->j_wbuf); |
1352 | kfree(journal); | |
44519faf HK |
1353 | |
1354 | return err; | |
470decc6 DK |
1355 | } |
1356 | ||
1357 | ||
1358 | /** | |
f7f4bccb | 1359 | *int jbd2_journal_check_used_features () - Check if features specified are used. |
470decc6 DK |
1360 | * @journal: Journal to check. |
1361 | * @compat: bitmask of compatible features | |
1362 | * @ro: bitmask of features that force read-only mount | |
1363 | * @incompat: bitmask of incompatible features | |
1364 | * | |
1365 | * Check whether the journal uses all of a given set of | |
1366 | * features. Return true (non-zero) if it does. | |
1367 | **/ | |
1368 | ||
f7f4bccb | 1369 | int jbd2_journal_check_used_features (journal_t *journal, unsigned long compat, |
470decc6 DK |
1370 | unsigned long ro, unsigned long incompat) |
1371 | { | |
1372 | journal_superblock_t *sb; | |
1373 | ||
1374 | if (!compat && !ro && !incompat) | |
1375 | return 1; | |
1376 | if (journal->j_format_version == 1) | |
1377 | return 0; | |
1378 | ||
1379 | sb = journal->j_superblock; | |
1380 | ||
1381 | if (((be32_to_cpu(sb->s_feature_compat) & compat) == compat) && | |
1382 | ((be32_to_cpu(sb->s_feature_ro_compat) & ro) == ro) && | |
1383 | ((be32_to_cpu(sb->s_feature_incompat) & incompat) == incompat)) | |
1384 | return 1; | |
1385 | ||
1386 | return 0; | |
1387 | } | |
1388 | ||
1389 | /** | |
f7f4bccb | 1390 | * int jbd2_journal_check_available_features() - Check feature set in journalling layer |
470decc6 DK |
1391 | * @journal: Journal to check. |
1392 | * @compat: bitmask of compatible features | |
1393 | * @ro: bitmask of features that force read-only mount | |
1394 | * @incompat: bitmask of incompatible features | |
1395 | * | |
1396 | * Check whether the journaling code supports the use of | |
1397 | * all of a given set of features on this journal. Return true | |
1398 | * (non-zero) if it can. */ | |
1399 | ||
f7f4bccb | 1400 | int jbd2_journal_check_available_features (journal_t *journal, unsigned long compat, |
470decc6 DK |
1401 | unsigned long ro, unsigned long incompat) |
1402 | { | |
470decc6 DK |
1403 | if (!compat && !ro && !incompat) |
1404 | return 1; | |
1405 | ||
470decc6 DK |
1406 | /* We can support any known requested features iff the |
1407 | * superblock is in version 2. Otherwise we fail to support any | |
1408 | * extended sb features. */ | |
1409 | ||
1410 | if (journal->j_format_version != 2) | |
1411 | return 0; | |
1412 | ||
f7f4bccb MC |
1413 | if ((compat & JBD2_KNOWN_COMPAT_FEATURES) == compat && |
1414 | (ro & JBD2_KNOWN_ROCOMPAT_FEATURES) == ro && | |
1415 | (incompat & JBD2_KNOWN_INCOMPAT_FEATURES) == incompat) | |
470decc6 DK |
1416 | return 1; |
1417 | ||
1418 | return 0; | |
1419 | } | |
1420 | ||
1421 | /** | |
f7f4bccb | 1422 | * int jbd2_journal_set_features () - Mark a given journal feature in the superblock |
470decc6 DK |
1423 | * @journal: Journal to act on. |
1424 | * @compat: bitmask of compatible features | |
1425 | * @ro: bitmask of features that force read-only mount | |
1426 | * @incompat: bitmask of incompatible features | |
1427 | * | |
1428 | * Mark a given journal feature as present on the | |
1429 | * superblock. Returns true if the requested features could be set. | |
1430 | * | |
1431 | */ | |
1432 | ||
f7f4bccb | 1433 | int jbd2_journal_set_features (journal_t *journal, unsigned long compat, |
470decc6 DK |
1434 | unsigned long ro, unsigned long incompat) |
1435 | { | |
1436 | journal_superblock_t *sb; | |
1437 | ||
f7f4bccb | 1438 | if (jbd2_journal_check_used_features(journal, compat, ro, incompat)) |
470decc6 DK |
1439 | return 1; |
1440 | ||
f7f4bccb | 1441 | if (!jbd2_journal_check_available_features(journal, compat, ro, incompat)) |
470decc6 DK |
1442 | return 0; |
1443 | ||
1444 | jbd_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n", | |
1445 | compat, ro, incompat); | |
1446 | ||
1447 | sb = journal->j_superblock; | |
1448 | ||
1449 | sb->s_feature_compat |= cpu_to_be32(compat); | |
1450 | sb->s_feature_ro_compat |= cpu_to_be32(ro); | |
1451 | sb->s_feature_incompat |= cpu_to_be32(incompat); | |
1452 | ||
1453 | return 1; | |
1454 | } | |
1455 | ||
818d276c GS |
1456 | /* |
1457 | * jbd2_journal_clear_features () - Clear a given journal feature in the | |
1458 | * superblock | |
1459 | * @journal: Journal to act on. | |
1460 | * @compat: bitmask of compatible features | |
1461 | * @ro: bitmask of features that force read-only mount | |
1462 | * @incompat: bitmask of incompatible features | |
1463 | * | |
1464 | * Clear a given journal feature as present on the | |
1465 | * superblock. | |
1466 | */ | |
1467 | void jbd2_journal_clear_features(journal_t *journal, unsigned long compat, | |
1468 | unsigned long ro, unsigned long incompat) | |
1469 | { | |
1470 | journal_superblock_t *sb; | |
1471 | ||
1472 | jbd_debug(1, "Clear features 0x%lx/0x%lx/0x%lx\n", | |
1473 | compat, ro, incompat); | |
1474 | ||
1475 | sb = journal->j_superblock; | |
1476 | ||
1477 | sb->s_feature_compat &= ~cpu_to_be32(compat); | |
1478 | sb->s_feature_ro_compat &= ~cpu_to_be32(ro); | |
1479 | sb->s_feature_incompat &= ~cpu_to_be32(incompat); | |
1480 | } | |
1481 | EXPORT_SYMBOL(jbd2_journal_clear_features); | |
470decc6 DK |
1482 | |
1483 | /** | |
f7f4bccb | 1484 | * int jbd2_journal_update_format () - Update on-disk journal structure. |
470decc6 DK |
1485 | * @journal: Journal to act on. |
1486 | * | |
1487 | * Given an initialised but unloaded journal struct, poke about in the | |
1488 | * on-disk structure to update it to the most recent supported version. | |
1489 | */ | |
f7f4bccb | 1490 | int jbd2_journal_update_format (journal_t *journal) |
470decc6 DK |
1491 | { |
1492 | journal_superblock_t *sb; | |
1493 | int err; | |
1494 | ||
1495 | err = journal_get_superblock(journal); | |
1496 | if (err) | |
1497 | return err; | |
1498 | ||
1499 | sb = journal->j_superblock; | |
1500 | ||
1501 | switch (be32_to_cpu(sb->s_header.h_blocktype)) { | |
f7f4bccb | 1502 | case JBD2_SUPERBLOCK_V2: |
470decc6 | 1503 | return 0; |
f7f4bccb | 1504 | case JBD2_SUPERBLOCK_V1: |
470decc6 DK |
1505 | return journal_convert_superblock_v1(journal, sb); |
1506 | default: | |
1507 | break; | |
1508 | } | |
1509 | return -EINVAL; | |
1510 | } | |
1511 | ||
1512 | static int journal_convert_superblock_v1(journal_t *journal, | |
1513 | journal_superblock_t *sb) | |
1514 | { | |
1515 | int offset, blocksize; | |
1516 | struct buffer_head *bh; | |
1517 | ||
1518 | printk(KERN_WARNING | |
1519 | "JBD: Converting superblock from version 1 to 2.\n"); | |
1520 | ||
1521 | /* Pre-initialise new fields to zero */ | |
1522 | offset = ((char *) &(sb->s_feature_compat)) - ((char *) sb); | |
1523 | blocksize = be32_to_cpu(sb->s_blocksize); | |
1524 | memset(&sb->s_feature_compat, 0, blocksize-offset); | |
1525 | ||
1526 | sb->s_nr_users = cpu_to_be32(1); | |
f7f4bccb | 1527 | sb->s_header.h_blocktype = cpu_to_be32(JBD2_SUPERBLOCK_V2); |
470decc6 DK |
1528 | journal->j_format_version = 2; |
1529 | ||
1530 | bh = journal->j_sb_buffer; | |
1531 | BUFFER_TRACE(bh, "marking dirty"); | |
1532 | mark_buffer_dirty(bh); | |
1533 | sync_dirty_buffer(bh); | |
1534 | return 0; | |
1535 | } | |
1536 | ||
1537 | ||
1538 | /** | |
f7f4bccb | 1539 | * int jbd2_journal_flush () - Flush journal |
470decc6 DK |
1540 | * @journal: Journal to act on. |
1541 | * | |
1542 | * Flush all data for a given journal to disk and empty the journal. | |
1543 | * Filesystems can use this when remounting readonly to ensure that | |
1544 | * recovery does not need to happen on remount. | |
1545 | */ | |
1546 | ||
f7f4bccb | 1547 | int jbd2_journal_flush(journal_t *journal) |
470decc6 DK |
1548 | { |
1549 | int err = 0; | |
1550 | transaction_t *transaction = NULL; | |
1551 | unsigned long old_tail; | |
1552 | ||
a931da6a | 1553 | write_lock(&journal->j_state_lock); |
470decc6 DK |
1554 | |
1555 | /* Force everything buffered to the log... */ | |
1556 | if (journal->j_running_transaction) { | |
1557 | transaction = journal->j_running_transaction; | |
f7f4bccb | 1558 | __jbd2_log_start_commit(journal, transaction->t_tid); |
470decc6 DK |
1559 | } else if (journal->j_committing_transaction) |
1560 | transaction = journal->j_committing_transaction; | |
1561 | ||
1562 | /* Wait for the log commit to complete... */ | |
1563 | if (transaction) { | |
1564 | tid_t tid = transaction->t_tid; | |
1565 | ||
a931da6a | 1566 | write_unlock(&journal->j_state_lock); |
f7f4bccb | 1567 | jbd2_log_wait_commit(journal, tid); |
470decc6 | 1568 | } else { |
a931da6a | 1569 | write_unlock(&journal->j_state_lock); |
470decc6 DK |
1570 | } |
1571 | ||
1572 | /* ...and flush everything in the log out to disk. */ | |
1573 | spin_lock(&journal->j_list_lock); | |
1574 | while (!err && journal->j_checkpoint_transactions != NULL) { | |
1575 | spin_unlock(&journal->j_list_lock); | |
44519faf | 1576 | mutex_lock(&journal->j_checkpoint_mutex); |
f7f4bccb | 1577 | err = jbd2_log_do_checkpoint(journal); |
44519faf | 1578 | mutex_unlock(&journal->j_checkpoint_mutex); |
470decc6 DK |
1579 | spin_lock(&journal->j_list_lock); |
1580 | } | |
1581 | spin_unlock(&journal->j_list_lock); | |
44519faf HK |
1582 | |
1583 | if (is_journal_aborted(journal)) | |
1584 | return -EIO; | |
1585 | ||
f7f4bccb | 1586 | jbd2_cleanup_journal_tail(journal); |
470decc6 DK |
1587 | |
1588 | /* Finally, mark the journal as really needing no recovery. | |
1589 | * This sets s_start==0 in the underlying superblock, which is | |
1590 | * the magic code for a fully-recovered superblock. Any future | |
1591 | * commits of data to the journal will restore the current | |
1592 | * s_start value. */ | |
a931da6a | 1593 | write_lock(&journal->j_state_lock); |
470decc6 DK |
1594 | old_tail = journal->j_tail; |
1595 | journal->j_tail = 0; | |
a931da6a | 1596 | write_unlock(&journal->j_state_lock); |
f7f4bccb | 1597 | jbd2_journal_update_superblock(journal, 1); |
a931da6a | 1598 | write_lock(&journal->j_state_lock); |
470decc6 DK |
1599 | journal->j_tail = old_tail; |
1600 | ||
1601 | J_ASSERT(!journal->j_running_transaction); | |
1602 | J_ASSERT(!journal->j_committing_transaction); | |
1603 | J_ASSERT(!journal->j_checkpoint_transactions); | |
1604 | J_ASSERT(journal->j_head == journal->j_tail); | |
1605 | J_ASSERT(journal->j_tail_sequence == journal->j_transaction_sequence); | |
a931da6a | 1606 | write_unlock(&journal->j_state_lock); |
44519faf | 1607 | return 0; |
470decc6 DK |
1608 | } |
1609 | ||
1610 | /** | |
f7f4bccb | 1611 | * int jbd2_journal_wipe() - Wipe journal contents |
470decc6 DK |
1612 | * @journal: Journal to act on. |
1613 | * @write: flag (see below) | |
1614 | * | |
1615 | * Wipe out all of the contents of a journal, safely. This will produce | |
1616 | * a warning if the journal contains any valid recovery information. | |
f7f4bccb | 1617 | * Must be called between journal_init_*() and jbd2_journal_load(). |
470decc6 DK |
1618 | * |
1619 | * If 'write' is non-zero, then we wipe out the journal on disk; otherwise | |
1620 | * we merely suppress recovery. | |
1621 | */ | |
1622 | ||
f7f4bccb | 1623 | int jbd2_journal_wipe(journal_t *journal, int write) |
470decc6 | 1624 | { |
470decc6 DK |
1625 | int err = 0; |
1626 | ||
f7f4bccb | 1627 | J_ASSERT (!(journal->j_flags & JBD2_LOADED)); |
470decc6 DK |
1628 | |
1629 | err = load_superblock(journal); | |
1630 | if (err) | |
1631 | return err; | |
1632 | ||
470decc6 DK |
1633 | if (!journal->j_tail) |
1634 | goto no_recovery; | |
1635 | ||
1636 | printk (KERN_WARNING "JBD: %s recovery information on journal\n", | |
1637 | write ? "Clearing" : "Ignoring"); | |
1638 | ||
f7f4bccb | 1639 | err = jbd2_journal_skip_recovery(journal); |
470decc6 | 1640 | if (write) |
f7f4bccb | 1641 | jbd2_journal_update_superblock(journal, 1); |
470decc6 DK |
1642 | |
1643 | no_recovery: | |
1644 | return err; | |
1645 | } | |
1646 | ||
470decc6 DK |
1647 | /* |
1648 | * Journal abort has very specific semantics, which we describe | |
1649 | * for journal abort. | |
1650 | * | |
bfcd3555 | 1651 | * Two internal functions, which provide abort to the jbd layer |
470decc6 DK |
1652 | * itself are here. |
1653 | */ | |
1654 | ||
1655 | /* | |
1656 | * Quick version for internal journal use (doesn't lock the journal). | |
1657 | * Aborts hard --- we mark the abort as occurred, but do _nothing_ else, | |
1658 | * and don't attempt to make any other journal updates. | |
1659 | */ | |
f7f4bccb | 1660 | void __jbd2_journal_abort_hard(journal_t *journal) |
470decc6 DK |
1661 | { |
1662 | transaction_t *transaction; | |
470decc6 | 1663 | |
f7f4bccb | 1664 | if (journal->j_flags & JBD2_ABORT) |
470decc6 DK |
1665 | return; |
1666 | ||
1667 | printk(KERN_ERR "Aborting journal on device %s.\n", | |
05496769 | 1668 | journal->j_devname); |
470decc6 | 1669 | |
a931da6a | 1670 | write_lock(&journal->j_state_lock); |
f7f4bccb | 1671 | journal->j_flags |= JBD2_ABORT; |
470decc6 DK |
1672 | transaction = journal->j_running_transaction; |
1673 | if (transaction) | |
f7f4bccb | 1674 | __jbd2_log_start_commit(journal, transaction->t_tid); |
a931da6a | 1675 | write_unlock(&journal->j_state_lock); |
470decc6 DK |
1676 | } |
1677 | ||
1678 | /* Soft abort: record the abort error status in the journal superblock, | |
1679 | * but don't do any other IO. */ | |
1680 | static void __journal_abort_soft (journal_t *journal, int errno) | |
1681 | { | |
f7f4bccb | 1682 | if (journal->j_flags & JBD2_ABORT) |
470decc6 DK |
1683 | return; |
1684 | ||
1685 | if (!journal->j_errno) | |
1686 | journal->j_errno = errno; | |
1687 | ||
f7f4bccb | 1688 | __jbd2_journal_abort_hard(journal); |
470decc6 DK |
1689 | |
1690 | if (errno) | |
f7f4bccb | 1691 | jbd2_journal_update_superblock(journal, 1); |
470decc6 DK |
1692 | } |
1693 | ||
1694 | /** | |
f7f4bccb | 1695 | * void jbd2_journal_abort () - Shutdown the journal immediately. |
470decc6 DK |
1696 | * @journal: the journal to shutdown. |
1697 | * @errno: an error number to record in the journal indicating | |
1698 | * the reason for the shutdown. | |
1699 | * | |
1700 | * Perform a complete, immediate shutdown of the ENTIRE | |
1701 | * journal (not of a single transaction). This operation cannot be | |
1702 | * undone without closing and reopening the journal. | |
1703 | * | |
f7f4bccb | 1704 | * The jbd2_journal_abort function is intended to support higher level error |
470decc6 DK |
1705 | * recovery mechanisms such as the ext2/ext3 remount-readonly error |
1706 | * mode. | |
1707 | * | |
1708 | * Journal abort has very specific semantics. Any existing dirty, | |
1709 | * unjournaled buffers in the main filesystem will still be written to | |
1710 | * disk by bdflush, but the journaling mechanism will be suspended | |
1711 | * immediately and no further transaction commits will be honoured. | |
1712 | * | |
1713 | * Any dirty, journaled buffers will be written back to disk without | |
1714 | * hitting the journal. Atomicity cannot be guaranteed on an aborted | |
1715 | * filesystem, but we _do_ attempt to leave as much data as possible | |
1716 | * behind for fsck to use for cleanup. | |
1717 | * | |
1718 | * Any attempt to get a new transaction handle on a journal which is in | |
1719 | * ABORT state will just result in an -EROFS error return. A | |
f7f4bccb | 1720 | * jbd2_journal_stop on an existing handle will return -EIO if we have |
470decc6 DK |
1721 | * entered abort state during the update. |
1722 | * | |
1723 | * Recursive transactions are not disturbed by journal abort until the | |
f7f4bccb | 1724 | * final jbd2_journal_stop, which will receive the -EIO error. |
470decc6 | 1725 | * |
f7f4bccb | 1726 | * Finally, the jbd2_journal_abort call allows the caller to supply an errno |
470decc6 DK |
1727 | * which will be recorded (if possible) in the journal superblock. This |
1728 | * allows a client to record failure conditions in the middle of a | |
1729 | * transaction without having to complete the transaction to record the | |
1730 | * failure to disk. ext3_error, for example, now uses this | |
1731 | * functionality. | |
1732 | * | |
1733 | * Errors which originate from within the journaling layer will NOT | |
1734 | * supply an errno; a null errno implies that absolutely no further | |
1735 | * writes are done to the journal (unless there are any already in | |
1736 | * progress). | |
1737 | * | |
1738 | */ | |
1739 | ||
f7f4bccb | 1740 | void jbd2_journal_abort(journal_t *journal, int errno) |
470decc6 DK |
1741 | { |
1742 | __journal_abort_soft(journal, errno); | |
1743 | } | |
1744 | ||
1745 | /** | |
f7f4bccb | 1746 | * int jbd2_journal_errno () - returns the journal's error state. |
470decc6 DK |
1747 | * @journal: journal to examine. |
1748 | * | |
bfcd3555 | 1749 | * This is the errno number set with jbd2_journal_abort(), the last |
470decc6 DK |
1750 | * time the journal was mounted - if the journal was stopped |
1751 | * without calling abort this will be 0. | |
1752 | * | |
1753 | * If the journal has been aborted on this mount time -EROFS will | |
1754 | * be returned. | |
1755 | */ | |
f7f4bccb | 1756 | int jbd2_journal_errno(journal_t *journal) |
470decc6 DK |
1757 | { |
1758 | int err; | |
1759 | ||
a931da6a | 1760 | read_lock(&journal->j_state_lock); |
f7f4bccb | 1761 | if (journal->j_flags & JBD2_ABORT) |
470decc6 DK |
1762 | err = -EROFS; |
1763 | else | |
1764 | err = journal->j_errno; | |
a931da6a | 1765 | read_unlock(&journal->j_state_lock); |
470decc6 DK |
1766 | return err; |
1767 | } | |
1768 | ||
1769 | /** | |
f7f4bccb | 1770 | * int jbd2_journal_clear_err () - clears the journal's error state |
470decc6 DK |
1771 | * @journal: journal to act on. |
1772 | * | |
bfcd3555 | 1773 | * An error must be cleared or acked to take a FS out of readonly |
470decc6 DK |
1774 | * mode. |
1775 | */ | |
f7f4bccb | 1776 | int jbd2_journal_clear_err(journal_t *journal) |
470decc6 DK |
1777 | { |
1778 | int err = 0; | |
1779 | ||
a931da6a | 1780 | write_lock(&journal->j_state_lock); |
f7f4bccb | 1781 | if (journal->j_flags & JBD2_ABORT) |
470decc6 DK |
1782 | err = -EROFS; |
1783 | else | |
1784 | journal->j_errno = 0; | |
a931da6a | 1785 | write_unlock(&journal->j_state_lock); |
470decc6 DK |
1786 | return err; |
1787 | } | |
1788 | ||
1789 | /** | |
f7f4bccb | 1790 | * void jbd2_journal_ack_err() - Ack journal err. |
470decc6 DK |
1791 | * @journal: journal to act on. |
1792 | * | |
bfcd3555 | 1793 | * An error must be cleared or acked to take a FS out of readonly |
470decc6 DK |
1794 | * mode. |
1795 | */ | |
f7f4bccb | 1796 | void jbd2_journal_ack_err(journal_t *journal) |
470decc6 | 1797 | { |
a931da6a | 1798 | write_lock(&journal->j_state_lock); |
470decc6 | 1799 | if (journal->j_errno) |
f7f4bccb | 1800 | journal->j_flags |= JBD2_ACK_ERR; |
a931da6a | 1801 | write_unlock(&journal->j_state_lock); |
470decc6 DK |
1802 | } |
1803 | ||
f7f4bccb | 1804 | int jbd2_journal_blocks_per_page(struct inode *inode) |
470decc6 DK |
1805 | { |
1806 | return 1 << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits); | |
1807 | } | |
1808 | ||
b517bea1 ZB |
1809 | /* |
1810 | * helper functions to deal with 32 or 64bit block numbers. | |
1811 | */ | |
1812 | size_t journal_tag_bytes(journal_t *journal) | |
1813 | { | |
1814 | if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT)) | |
cd02ff0b | 1815 | return JBD2_TAG_SIZE64; |
b517bea1 | 1816 | else |
cd02ff0b | 1817 | return JBD2_TAG_SIZE32; |
b517bea1 ZB |
1818 | } |
1819 | ||
d2eecb03 TT |
1820 | /* |
1821 | * JBD memory management | |
1822 | * | |
1823 | * These functions are used to allocate block-sized chunks of memory | |
1824 | * used for making copies of buffer_head data. Very often it will be | |
1825 | * page-sized chunks of data, but sometimes it will be in | |
1826 | * sub-page-size chunks. (For example, 16k pages on Power systems | |
1827 | * with a 4k block file system.) For blocks smaller than a page, we | |
1828 | * use a SLAB allocator. There are slab caches for each block size, | |
1829 | * which are allocated at mount time, if necessary, and we only free | |
1830 | * (all of) the slab caches when/if the jbd2 module is unloaded. For | |
1831 | * this reason we don't need to a mutex to protect access to | |
1832 | * jbd2_slab[] allocating or releasing memory; only in | |
1833 | * jbd2_journal_create_slab(). | |
1834 | */ | |
1835 | #define JBD2_MAX_SLABS 8 | |
1836 | static struct kmem_cache *jbd2_slab[JBD2_MAX_SLABS]; | |
1837 | static DECLARE_MUTEX(jbd2_slab_create_sem); | |
1838 | ||
1839 | static const char *jbd2_slab_names[JBD2_MAX_SLABS] = { | |
1840 | "jbd2_1k", "jbd2_2k", "jbd2_4k", "jbd2_8k", | |
1841 | "jbd2_16k", "jbd2_32k", "jbd2_64k", "jbd2_128k" | |
1842 | }; | |
1843 | ||
1844 | ||
1845 | static void jbd2_journal_destroy_slabs(void) | |
1846 | { | |
1847 | int i; | |
1848 | ||
1849 | for (i = 0; i < JBD2_MAX_SLABS; i++) { | |
1850 | if (jbd2_slab[i]) | |
1851 | kmem_cache_destroy(jbd2_slab[i]); | |
1852 | jbd2_slab[i] = NULL; | |
1853 | } | |
1854 | } | |
1855 | ||
1856 | static int jbd2_journal_create_slab(size_t size) | |
1857 | { | |
1858 | int i = order_base_2(size) - 10; | |
1859 | size_t slab_size; | |
1860 | ||
1861 | if (size == PAGE_SIZE) | |
1862 | return 0; | |
1863 | ||
1864 | if (i >= JBD2_MAX_SLABS) | |
1865 | return -EINVAL; | |
1866 | ||
1867 | if (unlikely(i < 0)) | |
1868 | i = 0; | |
1869 | down(&jbd2_slab_create_sem); | |
1870 | if (jbd2_slab[i]) { | |
1871 | up(&jbd2_slab_create_sem); | |
1872 | return 0; /* Already created */ | |
1873 | } | |
1874 | ||
1875 | slab_size = 1 << (i+10); | |
1876 | jbd2_slab[i] = kmem_cache_create(jbd2_slab_names[i], slab_size, | |
1877 | slab_size, 0, NULL); | |
1878 | up(&jbd2_slab_create_sem); | |
1879 | if (!jbd2_slab[i]) { | |
1880 | printk(KERN_EMERG "JBD2: no memory for jbd2_slab cache\n"); | |
1881 | return -ENOMEM; | |
1882 | } | |
1883 | return 0; | |
1884 | } | |
1885 | ||
1886 | static struct kmem_cache *get_slab(size_t size) | |
1887 | { | |
1888 | int i = order_base_2(size) - 10; | |
1889 | ||
1890 | BUG_ON(i >= JBD2_MAX_SLABS); | |
1891 | if (unlikely(i < 0)) | |
1892 | i = 0; | |
8ac97b74 | 1893 | BUG_ON(jbd2_slab[i] == NULL); |
d2eecb03 TT |
1894 | return jbd2_slab[i]; |
1895 | } | |
1896 | ||
1897 | void *jbd2_alloc(size_t size, gfp_t flags) | |
1898 | { | |
1899 | void *ptr; | |
1900 | ||
1901 | BUG_ON(size & (size-1)); /* Must be a power of 2 */ | |
1902 | ||
1903 | flags |= __GFP_REPEAT; | |
1904 | if (size == PAGE_SIZE) | |
1905 | ptr = (void *)__get_free_pages(flags, 0); | |
1906 | else if (size > PAGE_SIZE) { | |
1907 | int order = get_order(size); | |
1908 | ||
1909 | if (order < 3) | |
1910 | ptr = (void *)__get_free_pages(flags, order); | |
1911 | else | |
1912 | ptr = vmalloc(size); | |
1913 | } else | |
1914 | ptr = kmem_cache_alloc(get_slab(size), flags); | |
1915 | ||
1916 | /* Check alignment; SLUB has gotten this wrong in the past, | |
1917 | * and this can lead to user data corruption! */ | |
1918 | BUG_ON(((unsigned long) ptr) & (size-1)); | |
1919 | ||
1920 | return ptr; | |
1921 | } | |
1922 | ||
1923 | void jbd2_free(void *ptr, size_t size) | |
1924 | { | |
1925 | if (size == PAGE_SIZE) { | |
1926 | free_pages((unsigned long)ptr, 0); | |
1927 | return; | |
1928 | } | |
1929 | if (size > PAGE_SIZE) { | |
1930 | int order = get_order(size); | |
1931 | ||
1932 | if (order < 3) | |
1933 | free_pages((unsigned long)ptr, order); | |
1934 | else | |
1935 | vfree(ptr); | |
1936 | return; | |
1937 | } | |
1938 | kmem_cache_free(get_slab(size), ptr); | |
1939 | }; | |
1940 | ||
470decc6 DK |
1941 | /* |
1942 | * Journal_head storage management | |
1943 | */ | |
e18b890b | 1944 | static struct kmem_cache *jbd2_journal_head_cache; |
e23291b9 | 1945 | #ifdef CONFIG_JBD2_DEBUG |
470decc6 DK |
1946 | static atomic_t nr_journal_heads = ATOMIC_INIT(0); |
1947 | #endif | |
1948 | ||
f7f4bccb | 1949 | static int journal_init_jbd2_journal_head_cache(void) |
470decc6 DK |
1950 | { |
1951 | int retval; | |
1952 | ||
1076d17a | 1953 | J_ASSERT(jbd2_journal_head_cache == NULL); |
a920e941 | 1954 | jbd2_journal_head_cache = kmem_cache_create("jbd2_journal_head", |
470decc6 DK |
1955 | sizeof(struct journal_head), |
1956 | 0, /* offset */ | |
77160957 | 1957 | SLAB_TEMPORARY, /* flags */ |
20c2df83 | 1958 | NULL); /* ctor */ |
470decc6 | 1959 | retval = 0; |
1076d17a | 1960 | if (!jbd2_journal_head_cache) { |
470decc6 DK |
1961 | retval = -ENOMEM; |
1962 | printk(KERN_EMERG "JBD: no memory for journal_head cache\n"); | |
1963 | } | |
1964 | return retval; | |
1965 | } | |
1966 | ||
f7f4bccb | 1967 | static void jbd2_journal_destroy_jbd2_journal_head_cache(void) |
470decc6 | 1968 | { |
8a9362eb DG |
1969 | if (jbd2_journal_head_cache) { |
1970 | kmem_cache_destroy(jbd2_journal_head_cache); | |
1971 | jbd2_journal_head_cache = NULL; | |
1972 | } | |
470decc6 DK |
1973 | } |
1974 | ||
1975 | /* | |
1976 | * journal_head splicing and dicing | |
1977 | */ | |
1978 | static struct journal_head *journal_alloc_journal_head(void) | |
1979 | { | |
1980 | struct journal_head *ret; | |
1981 | static unsigned long last_warning; | |
1982 | ||
e23291b9 | 1983 | #ifdef CONFIG_JBD2_DEBUG |
470decc6 DK |
1984 | atomic_inc(&nr_journal_heads); |
1985 | #endif | |
f7f4bccb | 1986 | ret = kmem_cache_alloc(jbd2_journal_head_cache, GFP_NOFS); |
1076d17a | 1987 | if (!ret) { |
470decc6 DK |
1988 | jbd_debug(1, "out of memory for journal_head\n"); |
1989 | if (time_after(jiffies, last_warning + 5*HZ)) { | |
1990 | printk(KERN_NOTICE "ENOMEM in %s, retrying.\n", | |
329d291f | 1991 | __func__); |
470decc6 DK |
1992 | last_warning = jiffies; |
1993 | } | |
1076d17a | 1994 | while (!ret) { |
470decc6 | 1995 | yield(); |
f7f4bccb | 1996 | ret = kmem_cache_alloc(jbd2_journal_head_cache, GFP_NOFS); |
470decc6 DK |
1997 | } |
1998 | } | |
1999 | return ret; | |
2000 | } | |
2001 | ||
2002 | static void journal_free_journal_head(struct journal_head *jh) | |
2003 | { | |
e23291b9 | 2004 | #ifdef CONFIG_JBD2_DEBUG |
470decc6 | 2005 | atomic_dec(&nr_journal_heads); |
cd02ff0b | 2006 | memset(jh, JBD2_POISON_FREE, sizeof(*jh)); |
470decc6 | 2007 | #endif |
f7f4bccb | 2008 | kmem_cache_free(jbd2_journal_head_cache, jh); |
470decc6 DK |
2009 | } |
2010 | ||
2011 | /* | |
2012 | * A journal_head is attached to a buffer_head whenever JBD has an | |
2013 | * interest in the buffer. | |
2014 | * | |
2015 | * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit | |
2016 | * is set. This bit is tested in core kernel code where we need to take | |
2017 | * JBD-specific actions. Testing the zeroness of ->b_private is not reliable | |
2018 | * there. | |
2019 | * | |
2020 | * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one. | |
2021 | * | |
2022 | * When a buffer has its BH_JBD bit set it is immune from being released by | |
2023 | * core kernel code, mainly via ->b_count. | |
2024 | * | |
2025 | * A journal_head may be detached from its buffer_head when the journal_head's | |
2026 | * b_transaction, b_cp_transaction and b_next_transaction pointers are NULL. | |
f7f4bccb | 2027 | * Various places in JBD call jbd2_journal_remove_journal_head() to indicate that the |
470decc6 DK |
2028 | * journal_head can be dropped if needed. |
2029 | * | |
2030 | * Various places in the kernel want to attach a journal_head to a buffer_head | |
2031 | * _before_ attaching the journal_head to a transaction. To protect the | |
f7f4bccb | 2032 | * journal_head in this situation, jbd2_journal_add_journal_head elevates the |
470decc6 | 2033 | * journal_head's b_jcount refcount by one. The caller must call |
f7f4bccb | 2034 | * jbd2_journal_put_journal_head() to undo this. |
470decc6 DK |
2035 | * |
2036 | * So the typical usage would be: | |
2037 | * | |
2038 | * (Attach a journal_head if needed. Increments b_jcount) | |
f7f4bccb | 2039 | * struct journal_head *jh = jbd2_journal_add_journal_head(bh); |
470decc6 DK |
2040 | * ... |
2041 | * jh->b_transaction = xxx; | |
f7f4bccb | 2042 | * jbd2_journal_put_journal_head(jh); |
470decc6 DK |
2043 | * |
2044 | * Now, the journal_head's b_jcount is zero, but it is safe from being released | |
2045 | * because it has a non-zero b_transaction. | |
2046 | */ | |
2047 | ||
2048 | /* | |
2049 | * Give a buffer_head a journal_head. | |
2050 | * | |
2051 | * Doesn't need the journal lock. | |
2052 | * May sleep. | |
2053 | */ | |
f7f4bccb | 2054 | struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh) |
470decc6 DK |
2055 | { |
2056 | struct journal_head *jh; | |
2057 | struct journal_head *new_jh = NULL; | |
2058 | ||
2059 | repeat: | |
2060 | if (!buffer_jbd(bh)) { | |
2061 | new_jh = journal_alloc_journal_head(); | |
2062 | memset(new_jh, 0, sizeof(*new_jh)); | |
2063 | } | |
2064 | ||
2065 | jbd_lock_bh_journal_head(bh); | |
2066 | if (buffer_jbd(bh)) { | |
2067 | jh = bh2jh(bh); | |
2068 | } else { | |
2069 | J_ASSERT_BH(bh, | |
2070 | (atomic_read(&bh->b_count) > 0) || | |
2071 | (bh->b_page && bh->b_page->mapping)); | |
2072 | ||
2073 | if (!new_jh) { | |
2074 | jbd_unlock_bh_journal_head(bh); | |
2075 | goto repeat; | |
2076 | } | |
2077 | ||
2078 | jh = new_jh; | |
2079 | new_jh = NULL; /* We consumed it */ | |
2080 | set_buffer_jbd(bh); | |
2081 | bh->b_private = jh; | |
2082 | jh->b_bh = bh; | |
2083 | get_bh(bh); | |
2084 | BUFFER_TRACE(bh, "added journal_head"); | |
2085 | } | |
2086 | jh->b_jcount++; | |
2087 | jbd_unlock_bh_journal_head(bh); | |
2088 | if (new_jh) | |
2089 | journal_free_journal_head(new_jh); | |
2090 | return bh->b_private; | |
2091 | } | |
2092 | ||
2093 | /* | |
2094 | * Grab a ref against this buffer_head's journal_head. If it ended up not | |
2095 | * having a journal_head, return NULL | |
2096 | */ | |
f7f4bccb | 2097 | struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh) |
470decc6 DK |
2098 | { |
2099 | struct journal_head *jh = NULL; | |
2100 | ||
2101 | jbd_lock_bh_journal_head(bh); | |
2102 | if (buffer_jbd(bh)) { | |
2103 | jh = bh2jh(bh); | |
2104 | jh->b_jcount++; | |
2105 | } | |
2106 | jbd_unlock_bh_journal_head(bh); | |
2107 | return jh; | |
2108 | } | |
2109 | ||
2110 | static void __journal_remove_journal_head(struct buffer_head *bh) | |
2111 | { | |
2112 | struct journal_head *jh = bh2jh(bh); | |
2113 | ||
2114 | J_ASSERT_JH(jh, jh->b_jcount >= 0); | |
2115 | ||
2116 | get_bh(bh); | |
2117 | if (jh->b_jcount == 0) { | |
2118 | if (jh->b_transaction == NULL && | |
2119 | jh->b_next_transaction == NULL && | |
2120 | jh->b_cp_transaction == NULL) { | |
2121 | J_ASSERT_JH(jh, jh->b_jlist == BJ_None); | |
2122 | J_ASSERT_BH(bh, buffer_jbd(bh)); | |
2123 | J_ASSERT_BH(bh, jh2bh(jh) == bh); | |
2124 | BUFFER_TRACE(bh, "remove journal_head"); | |
2125 | if (jh->b_frozen_data) { | |
2126 | printk(KERN_WARNING "%s: freeing " | |
2127 | "b_frozen_data\n", | |
329d291f | 2128 | __func__); |
af1e76d6 | 2129 | jbd2_free(jh->b_frozen_data, bh->b_size); |
470decc6 DK |
2130 | } |
2131 | if (jh->b_committed_data) { | |
2132 | printk(KERN_WARNING "%s: freeing " | |
2133 | "b_committed_data\n", | |
329d291f | 2134 | __func__); |
af1e76d6 | 2135 | jbd2_free(jh->b_committed_data, bh->b_size); |
470decc6 DK |
2136 | } |
2137 | bh->b_private = NULL; | |
2138 | jh->b_bh = NULL; /* debug, really */ | |
2139 | clear_buffer_jbd(bh); | |
2140 | __brelse(bh); | |
2141 | journal_free_journal_head(jh); | |
2142 | } else { | |
2143 | BUFFER_TRACE(bh, "journal_head was locked"); | |
2144 | } | |
2145 | } | |
2146 | } | |
2147 | ||
2148 | /* | |
f7f4bccb | 2149 | * jbd2_journal_remove_journal_head(): if the buffer isn't attached to a transaction |
470decc6 DK |
2150 | * and has a zero b_jcount then remove and release its journal_head. If we did |
2151 | * see that the buffer is not used by any transaction we also "logically" | |
2152 | * decrement ->b_count. | |
2153 | * | |
2154 | * We in fact take an additional increment on ->b_count as a convenience, | |
2155 | * because the caller usually wants to do additional things with the bh | |
2156 | * after calling here. | |
f7f4bccb | 2157 | * The caller of jbd2_journal_remove_journal_head() *must* run __brelse(bh) at some |
470decc6 DK |
2158 | * time. Once the caller has run __brelse(), the buffer is eligible for |
2159 | * reaping by try_to_free_buffers(). | |
2160 | */ | |
f7f4bccb | 2161 | void jbd2_journal_remove_journal_head(struct buffer_head *bh) |
470decc6 DK |
2162 | { |
2163 | jbd_lock_bh_journal_head(bh); | |
2164 | __journal_remove_journal_head(bh); | |
2165 | jbd_unlock_bh_journal_head(bh); | |
2166 | } | |
2167 | ||
2168 | /* | |
2169 | * Drop a reference on the passed journal_head. If it fell to zero then try to | |
2170 | * release the journal_head from the buffer_head. | |
2171 | */ | |
f7f4bccb | 2172 | void jbd2_journal_put_journal_head(struct journal_head *jh) |
470decc6 DK |
2173 | { |
2174 | struct buffer_head *bh = jh2bh(jh); | |
2175 | ||
2176 | jbd_lock_bh_journal_head(bh); | |
2177 | J_ASSERT_JH(jh, jh->b_jcount > 0); | |
2178 | --jh->b_jcount; | |
2179 | if (!jh->b_jcount && !jh->b_transaction) { | |
2180 | __journal_remove_journal_head(bh); | |
2181 | __brelse(bh); | |
2182 | } | |
2183 | jbd_unlock_bh_journal_head(bh); | |
2184 | } | |
2185 | ||
c851ed54 JK |
2186 | /* |
2187 | * Initialize jbd inode head | |
2188 | */ | |
2189 | void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode) | |
2190 | { | |
2191 | jinode->i_transaction = NULL; | |
2192 | jinode->i_next_transaction = NULL; | |
2193 | jinode->i_vfs_inode = inode; | |
2194 | jinode->i_flags = 0; | |
2195 | INIT_LIST_HEAD(&jinode->i_list); | |
2196 | } | |
2197 | ||
2198 | /* | |
2199 | * Function to be called before we start removing inode from memory (i.e., | |
2200 | * clear_inode() is a fine place to be called from). It removes inode from | |
2201 | * transaction's lists. | |
2202 | */ | |
2203 | void jbd2_journal_release_jbd_inode(journal_t *journal, | |
2204 | struct jbd2_inode *jinode) | |
2205 | { | |
c851ed54 JK |
2206 | if (!journal) |
2207 | return; | |
2208 | restart: | |
2209 | spin_lock(&journal->j_list_lock); | |
2210 | /* Is commit writing out inode - we have to wait */ | |
39e3ac25 | 2211 | if (test_bit(__JI_COMMIT_RUNNING, &jinode->i_flags)) { |
c851ed54 JK |
2212 | wait_queue_head_t *wq; |
2213 | DEFINE_WAIT_BIT(wait, &jinode->i_flags, __JI_COMMIT_RUNNING); | |
2214 | wq = bit_waitqueue(&jinode->i_flags, __JI_COMMIT_RUNNING); | |
2215 | prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE); | |
2216 | spin_unlock(&journal->j_list_lock); | |
2217 | schedule(); | |
2218 | finish_wait(wq, &wait.wait); | |
2219 | goto restart; | |
2220 | } | |
2221 | ||
c851ed54 JK |
2222 | if (jinode->i_transaction) { |
2223 | list_del(&jinode->i_list); | |
2224 | jinode->i_transaction = NULL; | |
2225 | } | |
2226 | spin_unlock(&journal->j_list_lock); | |
2227 | } | |
2228 | ||
470decc6 | 2229 | /* |
0f49d5d0 | 2230 | * debugfs tunables |
470decc6 | 2231 | */ |
6f38c74f JS |
2232 | #ifdef CONFIG_JBD2_DEBUG |
2233 | u8 jbd2_journal_enable_debug __read_mostly; | |
f7f4bccb | 2234 | EXPORT_SYMBOL(jbd2_journal_enable_debug); |
470decc6 | 2235 | |
0f49d5d0 | 2236 | #define JBD2_DEBUG_NAME "jbd2-debug" |
470decc6 | 2237 | |
6f38c74f JS |
2238 | static struct dentry *jbd2_debugfs_dir; |
2239 | static struct dentry *jbd2_debug; | |
470decc6 | 2240 | |
0f49d5d0 JS |
2241 | static void __init jbd2_create_debugfs_entry(void) |
2242 | { | |
2243 | jbd2_debugfs_dir = debugfs_create_dir("jbd2", NULL); | |
2244 | if (jbd2_debugfs_dir) | |
765f8361 YK |
2245 | jbd2_debug = debugfs_create_u8(JBD2_DEBUG_NAME, |
2246 | S_IRUGO | S_IWUSR, | |
0f49d5d0 JS |
2247 | jbd2_debugfs_dir, |
2248 | &jbd2_journal_enable_debug); | |
470decc6 DK |
2249 | } |
2250 | ||
0f49d5d0 | 2251 | static void __exit jbd2_remove_debugfs_entry(void) |
470decc6 | 2252 | { |
6f38c74f JS |
2253 | debugfs_remove(jbd2_debug); |
2254 | debugfs_remove(jbd2_debugfs_dir); | |
470decc6 DK |
2255 | } |
2256 | ||
0f49d5d0 | 2257 | #else |
470decc6 | 2258 | |
0f49d5d0 | 2259 | static void __init jbd2_create_debugfs_entry(void) |
470decc6 | 2260 | { |
470decc6 DK |
2261 | } |
2262 | ||
0f49d5d0 | 2263 | static void __exit jbd2_remove_debugfs_entry(void) |
470decc6 | 2264 | { |
470decc6 DK |
2265 | } |
2266 | ||
470decc6 DK |
2267 | #endif |
2268 | ||
8e85fb3f JL |
2269 | #ifdef CONFIG_PROC_FS |
2270 | ||
2271 | #define JBD2_STATS_PROC_NAME "fs/jbd2" | |
2272 | ||
2273 | static void __init jbd2_create_jbd_stats_proc_entry(void) | |
2274 | { | |
2275 | proc_jbd2_stats = proc_mkdir(JBD2_STATS_PROC_NAME, NULL); | |
2276 | } | |
2277 | ||
2278 | static void __exit jbd2_remove_jbd_stats_proc_entry(void) | |
2279 | { | |
2280 | if (proc_jbd2_stats) | |
2281 | remove_proc_entry(JBD2_STATS_PROC_NAME, NULL); | |
2282 | } | |
2283 | ||
2284 | #else | |
2285 | ||
2286 | #define jbd2_create_jbd_stats_proc_entry() do {} while (0) | |
2287 | #define jbd2_remove_jbd_stats_proc_entry() do {} while (0) | |
2288 | ||
2289 | #endif | |
2290 | ||
e18b890b | 2291 | struct kmem_cache *jbd2_handle_cache; |
470decc6 DK |
2292 | |
2293 | static int __init journal_init_handle_cache(void) | |
2294 | { | |
a920e941 | 2295 | jbd2_handle_cache = kmem_cache_create("jbd2_journal_handle", |
470decc6 DK |
2296 | sizeof(handle_t), |
2297 | 0, /* offset */ | |
77160957 | 2298 | SLAB_TEMPORARY, /* flags */ |
20c2df83 | 2299 | NULL); /* ctor */ |
f7f4bccb | 2300 | if (jbd2_handle_cache == NULL) { |
470decc6 DK |
2301 | printk(KERN_EMERG "JBD: failed to create handle cache\n"); |
2302 | return -ENOMEM; | |
2303 | } | |
2304 | return 0; | |
2305 | } | |
2306 | ||
f7f4bccb | 2307 | static void jbd2_journal_destroy_handle_cache(void) |
470decc6 | 2308 | { |
f7f4bccb MC |
2309 | if (jbd2_handle_cache) |
2310 | kmem_cache_destroy(jbd2_handle_cache); | |
470decc6 DK |
2311 | } |
2312 | ||
2313 | /* | |
2314 | * Module startup and shutdown | |
2315 | */ | |
2316 | ||
2317 | static int __init journal_init_caches(void) | |
2318 | { | |
2319 | int ret; | |
2320 | ||
f7f4bccb | 2321 | ret = jbd2_journal_init_revoke_caches(); |
470decc6 | 2322 | if (ret == 0) |
f7f4bccb | 2323 | ret = journal_init_jbd2_journal_head_cache(); |
470decc6 DK |
2324 | if (ret == 0) |
2325 | ret = journal_init_handle_cache(); | |
2326 | return ret; | |
2327 | } | |
2328 | ||
f7f4bccb | 2329 | static void jbd2_journal_destroy_caches(void) |
470decc6 | 2330 | { |
f7f4bccb MC |
2331 | jbd2_journal_destroy_revoke_caches(); |
2332 | jbd2_journal_destroy_jbd2_journal_head_cache(); | |
2333 | jbd2_journal_destroy_handle_cache(); | |
d2eecb03 | 2334 | jbd2_journal_destroy_slabs(); |
470decc6 DK |
2335 | } |
2336 | ||
2337 | static int __init journal_init(void) | |
2338 | { | |
2339 | int ret; | |
2340 | ||
2341 | BUILD_BUG_ON(sizeof(struct journal_superblock_s) != 1024); | |
2342 | ||
2343 | ret = journal_init_caches(); | |
620de4e1 DG |
2344 | if (ret == 0) { |
2345 | jbd2_create_debugfs_entry(); | |
2346 | jbd2_create_jbd_stats_proc_entry(); | |
2347 | } else { | |
f7f4bccb | 2348 | jbd2_journal_destroy_caches(); |
620de4e1 | 2349 | } |
470decc6 DK |
2350 | return ret; |
2351 | } | |
2352 | ||
2353 | static void __exit journal_exit(void) | |
2354 | { | |
e23291b9 | 2355 | #ifdef CONFIG_JBD2_DEBUG |
470decc6 DK |
2356 | int n = atomic_read(&nr_journal_heads); |
2357 | if (n) | |
2358 | printk(KERN_EMERG "JBD: leaked %d journal_heads!\n", n); | |
2359 | #endif | |
0f49d5d0 | 2360 | jbd2_remove_debugfs_entry(); |
8e85fb3f | 2361 | jbd2_remove_jbd_stats_proc_entry(); |
f7f4bccb | 2362 | jbd2_journal_destroy_caches(); |
470decc6 DK |
2363 | } |
2364 | ||
879c5e6b TT |
2365 | /* |
2366 | * jbd2_dev_to_name is a utility function used by the jbd2 and ext4 | |
2367 | * tracing infrastructure to map a dev_t to a device name. | |
2368 | * | |
2369 | * The caller should use rcu_read_lock() in order to make sure the | |
2370 | * device name stays valid until its done with it. We use | |
2371 | * rcu_read_lock() as well to make sure we're safe in case the caller | |
2372 | * gets sloppy, and because rcu_read_lock() is cheap and can be safely | |
2373 | * nested. | |
2374 | */ | |
2375 | struct devname_cache { | |
2376 | struct rcu_head rcu; | |
2377 | dev_t device; | |
2378 | char devname[BDEVNAME_SIZE]; | |
2379 | }; | |
2380 | #define CACHE_SIZE_BITS 6 | |
2381 | static struct devname_cache *devcache[1 << CACHE_SIZE_BITS]; | |
2382 | static DEFINE_SPINLOCK(devname_cache_lock); | |
2383 | ||
2384 | static void free_devcache(struct rcu_head *rcu) | |
2385 | { | |
2386 | kfree(rcu); | |
2387 | } | |
2388 | ||
2389 | const char *jbd2_dev_to_name(dev_t device) | |
2390 | { | |
2391 | int i = hash_32(device, CACHE_SIZE_BITS); | |
2392 | char *ret; | |
2393 | struct block_device *bd; | |
b5744805 | 2394 | static struct devname_cache *new_dev; |
879c5e6b TT |
2395 | |
2396 | rcu_read_lock(); | |
2397 | if (devcache[i] && devcache[i]->device == device) { | |
2398 | ret = devcache[i]->devname; | |
2399 | rcu_read_unlock(); | |
2400 | return ret; | |
2401 | } | |
2402 | rcu_read_unlock(); | |
2403 | ||
b5744805 TT |
2404 | new_dev = kmalloc(sizeof(struct devname_cache), GFP_KERNEL); |
2405 | if (!new_dev) | |
2406 | return "NODEV-ALLOCFAILURE"; /* Something non-NULL */ | |
879c5e6b TT |
2407 | spin_lock(&devname_cache_lock); |
2408 | if (devcache[i]) { | |
2409 | if (devcache[i]->device == device) { | |
b5744805 | 2410 | kfree(new_dev); |
879c5e6b TT |
2411 | ret = devcache[i]->devname; |
2412 | spin_unlock(&devname_cache_lock); | |
2413 | return ret; | |
2414 | } | |
2415 | call_rcu(&devcache[i]->rcu, free_devcache); | |
2416 | } | |
b5744805 | 2417 | devcache[i] = new_dev; |
879c5e6b TT |
2418 | devcache[i]->device = device; |
2419 | bd = bdget(device); | |
2420 | if (bd) { | |
2421 | bdevname(bd, devcache[i]->devname); | |
2422 | bdput(bd); | |
2423 | } else | |
2424 | __bdevname(device, devcache[i]->devname); | |
2425 | ret = devcache[i]->devname; | |
2426 | spin_unlock(&devname_cache_lock); | |
2427 | return ret; | |
2428 | } | |
2429 | EXPORT_SYMBOL(jbd2_dev_to_name); | |
2430 | ||
470decc6 DK |
2431 | MODULE_LICENSE("GPL"); |
2432 | module_init(journal_init); | |
2433 | module_exit(journal_exit); | |
2434 |