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470decc6 | 1 | /* |
58862699 | 2 | * linux/fs/jbd2/revoke.c |
470decc6 DK |
3 | * |
4 | * Written by Stephen C. Tweedie <sct@redhat.com>, 2000 | |
5 | * | |
6 | * Copyright 2000 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 | * Journal revoke routines for the generic filesystem journaling code; | |
13 | * part of the ext2fs journaling system. | |
14 | * | |
15 | * Revoke is the mechanism used to prevent old log records for deleted | |
16 | * metadata from being replayed on top of newer data using the same | |
17 | * blocks. The revoke mechanism is used in two separate places: | |
18 | * | |
19 | * + Commit: during commit we write the entire list of the current | |
20 | * transaction's revoked blocks to the journal | |
21 | * | |
22 | * + Recovery: during recovery we record the transaction ID of all | |
23 | * revoked blocks. If there are multiple revoke records in the log | |
24 | * for a single block, only the last one counts, and if there is a log | |
25 | * entry for a block beyond the last revoke, then that log entry still | |
26 | * gets replayed. | |
27 | * | |
28 | * We can get interactions between revokes and new log data within a | |
29 | * single transaction: | |
30 | * | |
31 | * Block is revoked and then journaled: | |
32 | * The desired end result is the journaling of the new block, so we | |
33 | * cancel the revoke before the transaction commits. | |
34 | * | |
35 | * Block is journaled and then revoked: | |
36 | * The revoke must take precedence over the write of the block, so we | |
37 | * need either to cancel the journal entry or to write the revoke | |
38 | * later in the log than the log block. In this case, we choose the | |
39 | * latter: journaling a block cancels any revoke record for that block | |
40 | * in the current transaction, so any revoke for that block in the | |
41 | * transaction must have happened after the block was journaled and so | |
42 | * the revoke must take precedence. | |
43 | * | |
44 | * Block is revoked and then written as data: | |
45 | * The data write is allowed to succeed, but the revoke is _not_ | |
46 | * cancelled. We still need to prevent old log records from | |
47 | * overwriting the new data. We don't even need to clear the revoke | |
48 | * bit here. | |
49 | * | |
50 | * Revoke information on buffers is a tri-state value: | |
51 | * | |
52 | * RevokeValid clear: no cached revoke status, need to look it up | |
53 | * RevokeValid set, Revoked clear: | |
54 | * buffer has not been revoked, and cancel_revoke | |
55 | * need do nothing. | |
56 | * RevokeValid set, Revoked set: | |
57 | * buffer has been revoked. | |
58 | */ | |
59 | ||
60 | #ifndef __KERNEL__ | |
61 | #include "jfs_user.h" | |
62 | #else | |
63 | #include <linux/time.h> | |
64 | #include <linux/fs.h> | |
f7f4bccb | 65 | #include <linux/jbd2.h> |
470decc6 DK |
66 | #include <linux/errno.h> |
67 | #include <linux/slab.h> | |
68 | #include <linux/list.h> | |
470decc6 DK |
69 | #include <linux/init.h> |
70 | #endif | |
f482394c | 71 | #include <linux/log2.h> |
470decc6 | 72 | |
e18b890b CL |
73 | static struct kmem_cache *jbd2_revoke_record_cache; |
74 | static struct kmem_cache *jbd2_revoke_table_cache; | |
470decc6 DK |
75 | |
76 | /* Each revoke record represents one single revoked block. During | |
77 | journal replay, this involves recording the transaction ID of the | |
78 | last transaction to revoke this block. */ | |
79 | ||
f7f4bccb | 80 | struct jbd2_revoke_record_s |
470decc6 DK |
81 | { |
82 | struct list_head hash; | |
83 | tid_t sequence; /* Used for recovery only */ | |
18eba7aa | 84 | unsigned long long blocknr; |
470decc6 DK |
85 | }; |
86 | ||
87 | ||
88 | /* The revoke table is just a simple hash table of revoke records. */ | |
f7f4bccb | 89 | struct jbd2_revoke_table_s |
470decc6 DK |
90 | { |
91 | /* It is conceivable that we might want a larger hash table | |
92 | * for recovery. Must be a power of two. */ | |
93 | int hash_size; | |
94 | int hash_shift; | |
95 | struct list_head *hash_table; | |
96 | }; | |
97 | ||
98 | ||
99 | #ifdef __KERNEL__ | |
100 | static void write_one_revoke_record(journal_t *, transaction_t *, | |
101 | struct journal_head **, int *, | |
f7f4bccb | 102 | struct jbd2_revoke_record_s *); |
470decc6 DK |
103 | static void flush_descriptor(journal_t *, struct journal_head *, int); |
104 | #endif | |
105 | ||
106 | /* Utility functions to maintain the revoke table */ | |
107 | ||
108 | /* Borrowed from buffer.c: this is a tried and tested block hash function */ | |
18eba7aa | 109 | static inline int hash(journal_t *journal, unsigned long long block) |
470decc6 | 110 | { |
f7f4bccb | 111 | struct jbd2_revoke_table_s *table = journal->j_revoke; |
470decc6 | 112 | int hash_shift = table->hash_shift; |
29971769 | 113 | int hash = (int)block ^ (int)((block >> 31) >> 1); |
470decc6 | 114 | |
29971769 MC |
115 | return ((hash << (hash_shift - 6)) ^ |
116 | (hash >> 13) ^ | |
117 | (hash << (hash_shift - 12))) & (table->hash_size - 1); | |
470decc6 DK |
118 | } |
119 | ||
18eba7aa | 120 | static int insert_revoke_hash(journal_t *journal, unsigned long long blocknr, |
470decc6 DK |
121 | tid_t seq) |
122 | { | |
123 | struct list_head *hash_list; | |
f7f4bccb | 124 | struct jbd2_revoke_record_s *record; |
470decc6 DK |
125 | |
126 | repeat: | |
f7f4bccb | 127 | record = kmem_cache_alloc(jbd2_revoke_record_cache, GFP_NOFS); |
470decc6 DK |
128 | if (!record) |
129 | goto oom; | |
130 | ||
131 | record->sequence = seq; | |
132 | record->blocknr = blocknr; | |
133 | hash_list = &journal->j_revoke->hash_table[hash(journal, blocknr)]; | |
134 | spin_lock(&journal->j_revoke_lock); | |
135 | list_add(&record->hash, hash_list); | |
136 | spin_unlock(&journal->j_revoke_lock); | |
137 | return 0; | |
138 | ||
139 | oom: | |
140 | if (!journal_oom_retry) | |
141 | return -ENOMEM; | |
142 | jbd_debug(1, "ENOMEM in %s, retrying\n", __FUNCTION__); | |
143 | yield(); | |
144 | goto repeat; | |
145 | } | |
146 | ||
147 | /* Find a revoke record in the journal's hash table. */ | |
148 | ||
f7f4bccb | 149 | static struct jbd2_revoke_record_s *find_revoke_record(journal_t *journal, |
18eba7aa | 150 | unsigned long long blocknr) |
470decc6 DK |
151 | { |
152 | struct list_head *hash_list; | |
f7f4bccb | 153 | struct jbd2_revoke_record_s *record; |
470decc6 DK |
154 | |
155 | hash_list = &journal->j_revoke->hash_table[hash(journal, blocknr)]; | |
156 | ||
157 | spin_lock(&journal->j_revoke_lock); | |
f7f4bccb | 158 | record = (struct jbd2_revoke_record_s *) hash_list->next; |
470decc6 DK |
159 | while (&(record->hash) != hash_list) { |
160 | if (record->blocknr == blocknr) { | |
161 | spin_unlock(&journal->j_revoke_lock); | |
162 | return record; | |
163 | } | |
f7f4bccb | 164 | record = (struct jbd2_revoke_record_s *) record->hash.next; |
470decc6 DK |
165 | } |
166 | spin_unlock(&journal->j_revoke_lock); | |
167 | return NULL; | |
168 | } | |
169 | ||
f7f4bccb | 170 | int __init jbd2_journal_init_revoke_caches(void) |
470decc6 | 171 | { |
a920e941 | 172 | jbd2_revoke_record_cache = kmem_cache_create("jbd2_revoke_record", |
f7f4bccb | 173 | sizeof(struct jbd2_revoke_record_s), |
77160957 MC |
174 | 0, |
175 | SLAB_HWCACHE_ALIGN|SLAB_TEMPORARY, | |
176 | NULL); | |
f7f4bccb | 177 | if (jbd2_revoke_record_cache == 0) |
470decc6 DK |
178 | return -ENOMEM; |
179 | ||
a920e941 | 180 | jbd2_revoke_table_cache = kmem_cache_create("jbd2_revoke_table", |
f7f4bccb | 181 | sizeof(struct jbd2_revoke_table_s), |
77160957 | 182 | 0, SLAB_TEMPORARY, NULL); |
f7f4bccb MC |
183 | if (jbd2_revoke_table_cache == 0) { |
184 | kmem_cache_destroy(jbd2_revoke_record_cache); | |
185 | jbd2_revoke_record_cache = NULL; | |
470decc6 DK |
186 | return -ENOMEM; |
187 | } | |
188 | return 0; | |
189 | } | |
190 | ||
f7f4bccb | 191 | void jbd2_journal_destroy_revoke_caches(void) |
470decc6 | 192 | { |
f7f4bccb MC |
193 | kmem_cache_destroy(jbd2_revoke_record_cache); |
194 | jbd2_revoke_record_cache = NULL; | |
195 | kmem_cache_destroy(jbd2_revoke_table_cache); | |
196 | jbd2_revoke_table_cache = NULL; | |
470decc6 DK |
197 | } |
198 | ||
199 | /* Initialise the revoke table for a given journal to a given size. */ | |
200 | ||
f7f4bccb | 201 | int jbd2_journal_init_revoke(journal_t *journal, int hash_size) |
470decc6 DK |
202 | { |
203 | int shift, tmp; | |
204 | ||
205 | J_ASSERT (journal->j_revoke_table[0] == NULL); | |
206 | ||
207 | shift = 0; | |
208 | tmp = hash_size; | |
209 | while((tmp >>= 1UL) != 0UL) | |
210 | shift++; | |
211 | ||
f7f4bccb | 212 | journal->j_revoke_table[0] = kmem_cache_alloc(jbd2_revoke_table_cache, GFP_KERNEL); |
470decc6 DK |
213 | if (!journal->j_revoke_table[0]) |
214 | return -ENOMEM; | |
215 | journal->j_revoke = journal->j_revoke_table[0]; | |
216 | ||
217 | /* Check that the hash_size is a power of two */ | |
f482394c | 218 | J_ASSERT(is_power_of_2(hash_size)); |
470decc6 DK |
219 | |
220 | journal->j_revoke->hash_size = hash_size; | |
221 | ||
222 | journal->j_revoke->hash_shift = shift; | |
223 | ||
224 | journal->j_revoke->hash_table = | |
225 | kmalloc(hash_size * sizeof(struct list_head), GFP_KERNEL); | |
226 | if (!journal->j_revoke->hash_table) { | |
f7f4bccb | 227 | kmem_cache_free(jbd2_revoke_table_cache, journal->j_revoke_table[0]); |
470decc6 DK |
228 | journal->j_revoke = NULL; |
229 | return -ENOMEM; | |
230 | } | |
231 | ||
232 | for (tmp = 0; tmp < hash_size; tmp++) | |
233 | INIT_LIST_HEAD(&journal->j_revoke->hash_table[tmp]); | |
234 | ||
f7f4bccb | 235 | journal->j_revoke_table[1] = kmem_cache_alloc(jbd2_revoke_table_cache, GFP_KERNEL); |
470decc6 DK |
236 | if (!journal->j_revoke_table[1]) { |
237 | kfree(journal->j_revoke_table[0]->hash_table); | |
f7f4bccb | 238 | kmem_cache_free(jbd2_revoke_table_cache, journal->j_revoke_table[0]); |
470decc6 DK |
239 | return -ENOMEM; |
240 | } | |
241 | ||
242 | journal->j_revoke = journal->j_revoke_table[1]; | |
243 | ||
244 | /* Check that the hash_size is a power of two */ | |
f482394c | 245 | J_ASSERT(is_power_of_2(hash_size)); |
470decc6 DK |
246 | |
247 | journal->j_revoke->hash_size = hash_size; | |
248 | ||
249 | journal->j_revoke->hash_shift = shift; | |
250 | ||
251 | journal->j_revoke->hash_table = | |
252 | kmalloc(hash_size * sizeof(struct list_head), GFP_KERNEL); | |
253 | if (!journal->j_revoke->hash_table) { | |
254 | kfree(journal->j_revoke_table[0]->hash_table); | |
f7f4bccb MC |
255 | kmem_cache_free(jbd2_revoke_table_cache, journal->j_revoke_table[0]); |
256 | kmem_cache_free(jbd2_revoke_table_cache, journal->j_revoke_table[1]); | |
470decc6 DK |
257 | journal->j_revoke = NULL; |
258 | return -ENOMEM; | |
259 | } | |
260 | ||
261 | for (tmp = 0; tmp < hash_size; tmp++) | |
262 | INIT_LIST_HEAD(&journal->j_revoke->hash_table[tmp]); | |
263 | ||
264 | spin_lock_init(&journal->j_revoke_lock); | |
265 | ||
266 | return 0; | |
267 | } | |
268 | ||
269 | /* Destoy a journal's revoke table. The table must already be empty! */ | |
270 | ||
f7f4bccb | 271 | void jbd2_journal_destroy_revoke(journal_t *journal) |
470decc6 | 272 | { |
f7f4bccb | 273 | struct jbd2_revoke_table_s *table; |
470decc6 DK |
274 | struct list_head *hash_list; |
275 | int i; | |
276 | ||
277 | table = journal->j_revoke_table[0]; | |
278 | if (!table) | |
279 | return; | |
280 | ||
281 | for (i=0; i<table->hash_size; i++) { | |
282 | hash_list = &table->hash_table[i]; | |
283 | J_ASSERT (list_empty(hash_list)); | |
284 | } | |
285 | ||
286 | kfree(table->hash_table); | |
f7f4bccb | 287 | kmem_cache_free(jbd2_revoke_table_cache, table); |
470decc6 DK |
288 | journal->j_revoke = NULL; |
289 | ||
290 | table = journal->j_revoke_table[1]; | |
291 | if (!table) | |
292 | return; | |
293 | ||
294 | for (i=0; i<table->hash_size; i++) { | |
295 | hash_list = &table->hash_table[i]; | |
296 | J_ASSERT (list_empty(hash_list)); | |
297 | } | |
298 | ||
299 | kfree(table->hash_table); | |
f7f4bccb | 300 | kmem_cache_free(jbd2_revoke_table_cache, table); |
470decc6 DK |
301 | journal->j_revoke = NULL; |
302 | } | |
303 | ||
304 | ||
305 | #ifdef __KERNEL__ | |
306 | ||
307 | /* | |
f7f4bccb | 308 | * jbd2_journal_revoke: revoke a given buffer_head from the journal. This |
470decc6 DK |
309 | * prevents the block from being replayed during recovery if we take a |
310 | * crash after this current transaction commits. Any subsequent | |
311 | * metadata writes of the buffer in this transaction cancel the | |
312 | * revoke. | |
313 | * | |
314 | * Note that this call may block --- it is up to the caller to make | |
315 | * sure that there are no further calls to journal_write_metadata | |
316 | * before the revoke is complete. In ext3, this implies calling the | |
317 | * revoke before clearing the block bitmap when we are deleting | |
318 | * metadata. | |
319 | * | |
f7f4bccb | 320 | * Revoke performs a jbd2_journal_forget on any buffer_head passed in as a |
470decc6 DK |
321 | * parameter, but does _not_ forget the buffer_head if the bh was only |
322 | * found implicitly. | |
323 | * | |
324 | * bh_in may not be a journalled buffer - it may have come off | |
325 | * the hash tables without an attached journal_head. | |
326 | * | |
f7f4bccb | 327 | * If bh_in is non-zero, jbd2_journal_revoke() will decrement its b_count |
470decc6 DK |
328 | * by one. |
329 | */ | |
330 | ||
18eba7aa | 331 | int jbd2_journal_revoke(handle_t *handle, unsigned long long blocknr, |
470decc6 DK |
332 | struct buffer_head *bh_in) |
333 | { | |
334 | struct buffer_head *bh = NULL; | |
335 | journal_t *journal; | |
336 | struct block_device *bdev; | |
337 | int err; | |
338 | ||
339 | might_sleep(); | |
340 | if (bh_in) | |
341 | BUFFER_TRACE(bh_in, "enter"); | |
342 | ||
343 | journal = handle->h_transaction->t_journal; | |
f7f4bccb | 344 | if (!jbd2_journal_set_features(journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)){ |
470decc6 DK |
345 | J_ASSERT (!"Cannot set revoke feature!"); |
346 | return -EINVAL; | |
347 | } | |
348 | ||
349 | bdev = journal->j_fs_dev; | |
350 | bh = bh_in; | |
351 | ||
352 | if (!bh) { | |
353 | bh = __find_get_block(bdev, blocknr, journal->j_blocksize); | |
354 | if (bh) | |
355 | BUFFER_TRACE(bh, "found on hash"); | |
356 | } | |
cd02ff0b | 357 | #ifdef JBD2_EXPENSIVE_CHECKING |
470decc6 DK |
358 | else { |
359 | struct buffer_head *bh2; | |
360 | ||
361 | /* If there is a different buffer_head lying around in | |
362 | * memory anywhere... */ | |
363 | bh2 = __find_get_block(bdev, blocknr, journal->j_blocksize); | |
364 | if (bh2) { | |
365 | /* ... and it has RevokeValid status... */ | |
366 | if (bh2 != bh && buffer_revokevalid(bh2)) | |
367 | /* ...then it better be revoked too, | |
368 | * since it's illegal to create a revoke | |
369 | * record against a buffer_head which is | |
370 | * not marked revoked --- that would | |
371 | * risk missing a subsequent revoke | |
372 | * cancel. */ | |
373 | J_ASSERT_BH(bh2, buffer_revoked(bh2)); | |
374 | put_bh(bh2); | |
375 | } | |
376 | } | |
377 | #endif | |
378 | ||
379 | /* We really ought not ever to revoke twice in a row without | |
380 | first having the revoke cancelled: it's illegal to free a | |
381 | block twice without allocating it in between! */ | |
382 | if (bh) { | |
383 | if (!J_EXPECT_BH(bh, !buffer_revoked(bh), | |
384 | "inconsistent data on disk")) { | |
385 | if (!bh_in) | |
386 | brelse(bh); | |
387 | return -EIO; | |
388 | } | |
389 | set_buffer_revoked(bh); | |
390 | set_buffer_revokevalid(bh); | |
391 | if (bh_in) { | |
f7f4bccb MC |
392 | BUFFER_TRACE(bh_in, "call jbd2_journal_forget"); |
393 | jbd2_journal_forget(handle, bh_in); | |
470decc6 DK |
394 | } else { |
395 | BUFFER_TRACE(bh, "call brelse"); | |
396 | __brelse(bh); | |
397 | } | |
398 | } | |
399 | ||
29971769 | 400 | jbd_debug(2, "insert revoke for block %llu, bh_in=%p\n",blocknr, bh_in); |
470decc6 DK |
401 | err = insert_revoke_hash(journal, blocknr, |
402 | handle->h_transaction->t_tid); | |
403 | BUFFER_TRACE(bh_in, "exit"); | |
404 | return err; | |
405 | } | |
406 | ||
407 | /* | |
408 | * Cancel an outstanding revoke. For use only internally by the | |
f7f4bccb | 409 | * journaling code (called from jbd2_journal_get_write_access). |
470decc6 DK |
410 | * |
411 | * We trust buffer_revoked() on the buffer if the buffer is already | |
412 | * being journaled: if there is no revoke pending on the buffer, then we | |
413 | * don't do anything here. | |
414 | * | |
415 | * This would break if it were possible for a buffer to be revoked and | |
416 | * discarded, and then reallocated within the same transaction. In such | |
417 | * a case we would have lost the revoked bit, but when we arrived here | |
418 | * the second time we would still have a pending revoke to cancel. So, | |
419 | * do not trust the Revoked bit on buffers unless RevokeValid is also | |
420 | * set. | |
421 | * | |
422 | * The caller must have the journal locked. | |
423 | */ | |
f7f4bccb | 424 | int jbd2_journal_cancel_revoke(handle_t *handle, struct journal_head *jh) |
470decc6 | 425 | { |
f7f4bccb | 426 | struct jbd2_revoke_record_s *record; |
470decc6 DK |
427 | journal_t *journal = handle->h_transaction->t_journal; |
428 | int need_cancel; | |
429 | int did_revoke = 0; /* akpm: debug */ | |
430 | struct buffer_head *bh = jh2bh(jh); | |
431 | ||
432 | jbd_debug(4, "journal_head %p, cancelling revoke\n", jh); | |
433 | ||
434 | /* Is the existing Revoke bit valid? If so, we trust it, and | |
435 | * only perform the full cancel if the revoke bit is set. If | |
436 | * not, we can't trust the revoke bit, and we need to do the | |
437 | * full search for a revoke record. */ | |
438 | if (test_set_buffer_revokevalid(bh)) { | |
439 | need_cancel = test_clear_buffer_revoked(bh); | |
440 | } else { | |
441 | need_cancel = 1; | |
442 | clear_buffer_revoked(bh); | |
443 | } | |
444 | ||
445 | if (need_cancel) { | |
446 | record = find_revoke_record(journal, bh->b_blocknr); | |
447 | if (record) { | |
448 | jbd_debug(4, "cancelled existing revoke on " | |
449 | "blocknr %llu\n", (unsigned long long)bh->b_blocknr); | |
450 | spin_lock(&journal->j_revoke_lock); | |
451 | list_del(&record->hash); | |
452 | spin_unlock(&journal->j_revoke_lock); | |
f7f4bccb | 453 | kmem_cache_free(jbd2_revoke_record_cache, record); |
470decc6 DK |
454 | did_revoke = 1; |
455 | } | |
456 | } | |
457 | ||
cd02ff0b | 458 | #ifdef JBD2_EXPENSIVE_CHECKING |
470decc6 DK |
459 | /* There better not be one left behind by now! */ |
460 | record = find_revoke_record(journal, bh->b_blocknr); | |
461 | J_ASSERT_JH(jh, record == NULL); | |
462 | #endif | |
463 | ||
464 | /* Finally, have we just cleared revoke on an unhashed | |
465 | * buffer_head? If so, we'd better make sure we clear the | |
466 | * revoked status on any hashed alias too, otherwise the revoke | |
467 | * state machine will get very upset later on. */ | |
468 | if (need_cancel) { | |
469 | struct buffer_head *bh2; | |
470 | bh2 = __find_get_block(bh->b_bdev, bh->b_blocknr, bh->b_size); | |
471 | if (bh2) { | |
472 | if (bh2 != bh) | |
473 | clear_buffer_revoked(bh2); | |
474 | __brelse(bh2); | |
475 | } | |
476 | } | |
477 | return did_revoke; | |
478 | } | |
479 | ||
480 | /* journal_switch_revoke table select j_revoke for next transaction | |
481 | * we do not want to suspend any processing until all revokes are | |
482 | * written -bzzz | |
483 | */ | |
f7f4bccb | 484 | void jbd2_journal_switch_revoke_table(journal_t *journal) |
470decc6 DK |
485 | { |
486 | int i; | |
487 | ||
488 | if (journal->j_revoke == journal->j_revoke_table[0]) | |
489 | journal->j_revoke = journal->j_revoke_table[1]; | |
490 | else | |
491 | journal->j_revoke = journal->j_revoke_table[0]; | |
492 | ||
493 | for (i = 0; i < journal->j_revoke->hash_size; i++) | |
494 | INIT_LIST_HEAD(&journal->j_revoke->hash_table[i]); | |
495 | } | |
496 | ||
497 | /* | |
498 | * Write revoke records to the journal for all entries in the current | |
499 | * revoke hash, deleting the entries as we go. | |
500 | * | |
501 | * Called with the journal lock held. | |
502 | */ | |
503 | ||
f7f4bccb | 504 | void jbd2_journal_write_revoke_records(journal_t *journal, |
470decc6 DK |
505 | transaction_t *transaction) |
506 | { | |
507 | struct journal_head *descriptor; | |
f7f4bccb MC |
508 | struct jbd2_revoke_record_s *record; |
509 | struct jbd2_revoke_table_s *revoke; | |
470decc6 DK |
510 | struct list_head *hash_list; |
511 | int i, offset, count; | |
512 | ||
513 | descriptor = NULL; | |
514 | offset = 0; | |
515 | count = 0; | |
516 | ||
517 | /* select revoke table for committing transaction */ | |
518 | revoke = journal->j_revoke == journal->j_revoke_table[0] ? | |
519 | journal->j_revoke_table[1] : journal->j_revoke_table[0]; | |
520 | ||
521 | for (i = 0; i < revoke->hash_size; i++) { | |
522 | hash_list = &revoke->hash_table[i]; | |
523 | ||
524 | while (!list_empty(hash_list)) { | |
f7f4bccb | 525 | record = (struct jbd2_revoke_record_s *) |
470decc6 DK |
526 | hash_list->next; |
527 | write_one_revoke_record(journal, transaction, | |
528 | &descriptor, &offset, | |
529 | record); | |
530 | count++; | |
531 | list_del(&record->hash); | |
f7f4bccb | 532 | kmem_cache_free(jbd2_revoke_record_cache, record); |
470decc6 DK |
533 | } |
534 | } | |
535 | if (descriptor) | |
536 | flush_descriptor(journal, descriptor, offset); | |
537 | jbd_debug(1, "Wrote %d revoke records\n", count); | |
538 | } | |
539 | ||
540 | /* | |
541 | * Write out one revoke record. We need to create a new descriptor | |
542 | * block if the old one is full or if we have not already created one. | |
543 | */ | |
544 | ||
545 | static void write_one_revoke_record(journal_t *journal, | |
546 | transaction_t *transaction, | |
547 | struct journal_head **descriptorp, | |
548 | int *offsetp, | |
f7f4bccb | 549 | struct jbd2_revoke_record_s *record) |
470decc6 DK |
550 | { |
551 | struct journal_head *descriptor; | |
552 | int offset; | |
553 | journal_header_t *header; | |
554 | ||
555 | /* If we are already aborting, this all becomes a noop. We | |
556 | still need to go round the loop in | |
f7f4bccb | 557 | jbd2_journal_write_revoke_records in order to free all of the |
470decc6 DK |
558 | revoke records: only the IO to the journal is omitted. */ |
559 | if (is_journal_aborted(journal)) | |
560 | return; | |
561 | ||
562 | descriptor = *descriptorp; | |
563 | offset = *offsetp; | |
564 | ||
565 | /* Make sure we have a descriptor with space left for the record */ | |
566 | if (descriptor) { | |
567 | if (offset == journal->j_blocksize) { | |
568 | flush_descriptor(journal, descriptor, offset); | |
569 | descriptor = NULL; | |
570 | } | |
571 | } | |
572 | ||
573 | if (!descriptor) { | |
f7f4bccb | 574 | descriptor = jbd2_journal_get_descriptor_buffer(journal); |
470decc6 DK |
575 | if (!descriptor) |
576 | return; | |
577 | header = (journal_header_t *) &jh2bh(descriptor)->b_data[0]; | |
f7f4bccb MC |
578 | header->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER); |
579 | header->h_blocktype = cpu_to_be32(JBD2_REVOKE_BLOCK); | |
470decc6 DK |
580 | header->h_sequence = cpu_to_be32(transaction->t_tid); |
581 | ||
582 | /* Record it so that we can wait for IO completion later */ | |
583 | JBUFFER_TRACE(descriptor, "file as BJ_LogCtl"); | |
f7f4bccb | 584 | jbd2_journal_file_buffer(descriptor, transaction, BJ_LogCtl); |
470decc6 | 585 | |
f7f4bccb | 586 | offset = sizeof(jbd2_journal_revoke_header_t); |
470decc6 DK |
587 | *descriptorp = descriptor; |
588 | } | |
589 | ||
b517bea1 ZB |
590 | if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT)) { |
591 | * ((__be64 *)(&jh2bh(descriptor)->b_data[offset])) = | |
592 | cpu_to_be64(record->blocknr); | |
593 | offset += 8; | |
594 | ||
595 | } else { | |
596 | * ((__be32 *)(&jh2bh(descriptor)->b_data[offset])) = | |
597 | cpu_to_be32(record->blocknr); | |
598 | offset += 4; | |
599 | } | |
600 | ||
470decc6 DK |
601 | *offsetp = offset; |
602 | } | |
603 | ||
604 | /* | |
605 | * Flush a revoke descriptor out to the journal. If we are aborting, | |
606 | * this is a noop; otherwise we are generating a buffer which needs to | |
607 | * be waited for during commit, so it has to go onto the appropriate | |
608 | * journal buffer list. | |
609 | */ | |
610 | ||
611 | static void flush_descriptor(journal_t *journal, | |
612 | struct journal_head *descriptor, | |
613 | int offset) | |
614 | { | |
f7f4bccb | 615 | jbd2_journal_revoke_header_t *header; |
470decc6 DK |
616 | struct buffer_head *bh = jh2bh(descriptor); |
617 | ||
618 | if (is_journal_aborted(journal)) { | |
619 | put_bh(bh); | |
620 | return; | |
621 | } | |
622 | ||
f7f4bccb | 623 | header = (jbd2_journal_revoke_header_t *) jh2bh(descriptor)->b_data; |
470decc6 DK |
624 | header->r_count = cpu_to_be32(offset); |
625 | set_buffer_jwrite(bh); | |
626 | BUFFER_TRACE(bh, "write"); | |
627 | set_buffer_dirty(bh); | |
628 | ll_rw_block(SWRITE, 1, &bh); | |
629 | } | |
630 | #endif | |
631 | ||
632 | /* | |
633 | * Revoke support for recovery. | |
634 | * | |
635 | * Recovery needs to be able to: | |
636 | * | |
637 | * record all revoke records, including the tid of the latest instance | |
638 | * of each revoke in the journal | |
639 | * | |
640 | * check whether a given block in a given transaction should be replayed | |
641 | * (ie. has not been revoked by a revoke record in that or a subsequent | |
642 | * transaction) | |
643 | * | |
644 | * empty the revoke table after recovery. | |
645 | */ | |
646 | ||
647 | /* | |
648 | * First, setting revoke records. We create a new revoke record for | |
649 | * every block ever revoked in the log as we scan it for recovery, and | |
650 | * we update the existing records if we find multiple revokes for a | |
651 | * single block. | |
652 | */ | |
653 | ||
f7f4bccb | 654 | int jbd2_journal_set_revoke(journal_t *journal, |
18eba7aa | 655 | unsigned long long blocknr, |
470decc6 DK |
656 | tid_t sequence) |
657 | { | |
f7f4bccb | 658 | struct jbd2_revoke_record_s *record; |
470decc6 DK |
659 | |
660 | record = find_revoke_record(journal, blocknr); | |
661 | if (record) { | |
662 | /* If we have multiple occurrences, only record the | |
663 | * latest sequence number in the hashed record */ | |
664 | if (tid_gt(sequence, record->sequence)) | |
665 | record->sequence = sequence; | |
666 | return 0; | |
667 | } | |
668 | return insert_revoke_hash(journal, blocknr, sequence); | |
669 | } | |
670 | ||
671 | /* | |
672 | * Test revoke records. For a given block referenced in the log, has | |
673 | * that block been revoked? A revoke record with a given transaction | |
674 | * sequence number revokes all blocks in that transaction and earlier | |
675 | * ones, but later transactions still need replayed. | |
676 | */ | |
677 | ||
f7f4bccb | 678 | int jbd2_journal_test_revoke(journal_t *journal, |
18eba7aa | 679 | unsigned long long blocknr, |
470decc6 DK |
680 | tid_t sequence) |
681 | { | |
f7f4bccb | 682 | struct jbd2_revoke_record_s *record; |
470decc6 DK |
683 | |
684 | record = find_revoke_record(journal, blocknr); | |
685 | if (!record) | |
686 | return 0; | |
687 | if (tid_gt(sequence, record->sequence)) | |
688 | return 0; | |
689 | return 1; | |
690 | } | |
691 | ||
692 | /* | |
693 | * Finally, once recovery is over, we need to clear the revoke table so | |
694 | * that it can be reused by the running filesystem. | |
695 | */ | |
696 | ||
f7f4bccb | 697 | void jbd2_journal_clear_revoke(journal_t *journal) |
470decc6 DK |
698 | { |
699 | int i; | |
700 | struct list_head *hash_list; | |
f7f4bccb MC |
701 | struct jbd2_revoke_record_s *record; |
702 | struct jbd2_revoke_table_s *revoke; | |
470decc6 DK |
703 | |
704 | revoke = journal->j_revoke; | |
705 | ||
706 | for (i = 0; i < revoke->hash_size; i++) { | |
707 | hash_list = &revoke->hash_table[i]; | |
708 | while (!list_empty(hash_list)) { | |
f7f4bccb | 709 | record = (struct jbd2_revoke_record_s*) hash_list->next; |
470decc6 | 710 | list_del(&record->hash); |
f7f4bccb | 711 | kmem_cache_free(jbd2_revoke_record_cache, record); |
470decc6 DK |
712 | } |
713 | } | |
714 | } |