blob: df36f42e19e11687b32bd08741c5969db325e116 [file] [log] [blame]
Dave Kleikamp470decc2006-10-11 01:20:57 -07001/*
Uwe Kleine-König58862692007-05-09 07:51:49 +02002 * linux/fs/jbd2/revoke.c
Dave Kleikamp470decc2006-10-11 01:20:57 -07003 *
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>
Mingming Caof7f4bcc2006-10-11 01:20:59 -070065#include <linux/jbd2.h>
Dave Kleikamp470decc2006-10-11 01:20:57 -070066#include <linux/errno.h>
67#include <linux/slab.h>
68#include <linux/list.h>
Dave Kleikamp470decc2006-10-11 01:20:57 -070069#include <linux/init.h>
70#endif
vignesh babuf4823942007-07-15 23:41:17 -070071#include <linux/log2.h>
Dave Kleikamp470decc2006-10-11 01:20:57 -070072
Christoph Lametere18b8902006-12-06 20:33:20 -080073static struct kmem_cache *jbd2_revoke_record_cache;
74static struct kmem_cache *jbd2_revoke_table_cache;
Dave Kleikamp470decc2006-10-11 01:20:57 -070075
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
Mingming Caof7f4bcc2006-10-11 01:20:59 -070080struct jbd2_revoke_record_s
Dave Kleikamp470decc2006-10-11 01:20:57 -070081{
82 struct list_head hash;
83 tid_t sequence; /* Used for recovery only */
Mingming Cao18eba7a2006-10-11 01:21:13 -070084 unsigned long long blocknr;
Dave Kleikamp470decc2006-10-11 01:20:57 -070085};
86
87
88/* The revoke table is just a simple hash table of revoke records. */
Mingming Caof7f4bcc2006-10-11 01:20:59 -070089struct jbd2_revoke_table_s
Dave Kleikamp470decc2006-10-11 01:20:57 -070090{
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__
100static void write_one_revoke_record(journal_t *, transaction_t *,
101 struct journal_head **, int *,
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700102 struct jbd2_revoke_record_s *);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700103static 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 */
Mingming Cao18eba7a2006-10-11 01:21:13 -0700109static inline int hash(journal_t *journal, unsigned long long block)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700110{
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700111 struct jbd2_revoke_table_s *table = journal->j_revoke;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700112 int hash_shift = table->hash_shift;
Mingming Cao29971762006-10-11 01:21:09 -0700113 int hash = (int)block ^ (int)((block >> 31) >> 1);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700114
Mingming Cao29971762006-10-11 01:21:09 -0700115 return ((hash << (hash_shift - 6)) ^
116 (hash >> 13) ^
117 (hash << (hash_shift - 12))) & (table->hash_size - 1);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700118}
119
Mingming Cao18eba7a2006-10-11 01:21:13 -0700120static int insert_revoke_hash(journal_t *journal, unsigned long long blocknr,
Dave Kleikamp470decc2006-10-11 01:20:57 -0700121 tid_t seq)
122{
123 struct list_head *hash_list;
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700124 struct jbd2_revoke_record_s *record;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700125
126repeat:
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700127 record = kmem_cache_alloc(jbd2_revoke_record_cache, GFP_NOFS);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700128 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
139oom:
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
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700149static struct jbd2_revoke_record_s *find_revoke_record(journal_t *journal,
Mingming Cao18eba7a2006-10-11 01:21:13 -0700150 unsigned long long blocknr)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700151{
152 struct list_head *hash_list;
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700153 struct jbd2_revoke_record_s *record;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700154
155 hash_list = &journal->j_revoke->hash_table[hash(journal, blocknr)];
156
157 spin_lock(&journal->j_revoke_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700158 record = (struct jbd2_revoke_record_s *) hash_list->next;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700159 while (&(record->hash) != hash_list) {
160 if (record->blocknr == blocknr) {
161 spin_unlock(&journal->j_revoke_lock);
162 return record;
163 }
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700164 record = (struct jbd2_revoke_record_s *) record->hash.next;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700165 }
166 spin_unlock(&journal->j_revoke_lock);
167 return NULL;
168}
169
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700170int __init jbd2_journal_init_revoke_caches(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700171{
Johann Lombardia920e942006-10-11 01:21:00 -0700172 jbd2_revoke_record_cache = kmem_cache_create("jbd2_revoke_record",
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700173 sizeof(struct jbd2_revoke_record_s),
Mingming Cao77160952008-01-28 23:58:27 -0500174 0,
175 SLAB_HWCACHE_ALIGN|SLAB_TEMPORARY,
176 NULL);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700177 if (jbd2_revoke_record_cache == 0)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700178 return -ENOMEM;
179
Johann Lombardia920e942006-10-11 01:21:00 -0700180 jbd2_revoke_table_cache = kmem_cache_create("jbd2_revoke_table",
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700181 sizeof(struct jbd2_revoke_table_s),
Mingming Cao77160952008-01-28 23:58:27 -0500182 0, SLAB_TEMPORARY, NULL);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700183 if (jbd2_revoke_table_cache == 0) {
184 kmem_cache_destroy(jbd2_revoke_record_cache);
185 jbd2_revoke_record_cache = NULL;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700186 return -ENOMEM;
187 }
188 return 0;
189}
190
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700191void jbd2_journal_destroy_revoke_caches(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700192{
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700193 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;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700197}
198
199/* Initialise the revoke table for a given journal to a given size. */
200
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700201int jbd2_journal_init_revoke(journal_t *journal, int hash_size)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700202{
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
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700212 journal->j_revoke_table[0] = kmem_cache_alloc(jbd2_revoke_table_cache, GFP_KERNEL);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700213 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 */
vignesh babuf4823942007-07-15 23:41:17 -0700218 J_ASSERT(is_power_of_2(hash_size));
Dave Kleikamp470decc2006-10-11 01:20:57 -0700219
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) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700227 kmem_cache_free(jbd2_revoke_table_cache, journal->j_revoke_table[0]);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700228 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
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700235 journal->j_revoke_table[1] = kmem_cache_alloc(jbd2_revoke_table_cache, GFP_KERNEL);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700236 if (!journal->j_revoke_table[1]) {
237 kfree(journal->j_revoke_table[0]->hash_table);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700238 kmem_cache_free(jbd2_revoke_table_cache, journal->j_revoke_table[0]);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700239 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 */
vignesh babuf4823942007-07-15 23:41:17 -0700245 J_ASSERT(is_power_of_2(hash_size));
Dave Kleikamp470decc2006-10-11 01:20:57 -0700246
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);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700255 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]);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700257 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
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700271void jbd2_journal_destroy_revoke(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700272{
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700273 struct jbd2_revoke_table_s *table;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700274 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);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700287 kmem_cache_free(jbd2_revoke_table_cache, table);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700288 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);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700300 kmem_cache_free(jbd2_revoke_table_cache, table);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700301 journal->j_revoke = NULL;
302}
303
304
305#ifdef __KERNEL__
306
307/*
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700308 * jbd2_journal_revoke: revoke a given buffer_head from the journal. This
Dave Kleikamp470decc2006-10-11 01:20:57 -0700309 * 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 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700320 * Revoke performs a jbd2_journal_forget on any buffer_head passed in as a
Dave Kleikamp470decc2006-10-11 01:20:57 -0700321 * 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 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700327 * If bh_in is non-zero, jbd2_journal_revoke() will decrement its b_count
Dave Kleikamp470decc2006-10-11 01:20:57 -0700328 * by one.
329 */
330
Mingming Cao18eba7a2006-10-11 01:21:13 -0700331int jbd2_journal_revoke(handle_t *handle, unsigned long long blocknr,
Dave Kleikamp470decc2006-10-11 01:20:57 -0700332 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;
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700344 if (!jbd2_journal_set_features(journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)){
Dave Kleikamp470decc2006-10-11 01:20:57 -0700345 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 }
Mingming Caocd02ff02007-10-16 18:38:25 -0400357#ifdef JBD2_EXPENSIVE_CHECKING
Dave Kleikamp470decc2006-10-11 01:20:57 -0700358 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) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700392 BUFFER_TRACE(bh_in, "call jbd2_journal_forget");
393 jbd2_journal_forget(handle, bh_in);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700394 } else {
395 BUFFER_TRACE(bh, "call brelse");
396 __brelse(bh);
397 }
398 }
399
Mingming Cao29971762006-10-11 01:21:09 -0700400 jbd_debug(2, "insert revoke for block %llu, bh_in=%p\n",blocknr, bh_in);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700401 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
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700409 * journaling code (called from jbd2_journal_get_write_access).
Dave Kleikamp470decc2006-10-11 01:20:57 -0700410 *
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 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700424int jbd2_journal_cancel_revoke(handle_t *handle, struct journal_head *jh)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700425{
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700426 struct jbd2_revoke_record_s *record;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700427 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);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700453 kmem_cache_free(jbd2_revoke_record_cache, record);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700454 did_revoke = 1;
455 }
456 }
457
Mingming Caocd02ff02007-10-16 18:38:25 -0400458#ifdef JBD2_EXPENSIVE_CHECKING
Dave Kleikamp470decc2006-10-11 01:20:57 -0700459 /* 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 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700484void jbd2_journal_switch_revoke_table(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700485{
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
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700504void jbd2_journal_write_revoke_records(journal_t *journal,
Dave Kleikamp470decc2006-10-11 01:20:57 -0700505 transaction_t *transaction)
506{
507 struct journal_head *descriptor;
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700508 struct jbd2_revoke_record_s *record;
509 struct jbd2_revoke_table_s *revoke;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700510 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)) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700525 record = (struct jbd2_revoke_record_s *)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700526 hash_list->next;
527 write_one_revoke_record(journal, transaction,
528 &descriptor, &offset,
529 record);
530 count++;
531 list_del(&record->hash);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700532 kmem_cache_free(jbd2_revoke_record_cache, record);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700533 }
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
545static void write_one_revoke_record(journal_t *journal,
546 transaction_t *transaction,
547 struct journal_head **descriptorp,
548 int *offsetp,
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700549 struct jbd2_revoke_record_s *record)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700550{
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
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700557 jbd2_journal_write_revoke_records in order to free all of the
Dave Kleikamp470decc2006-10-11 01:20:57 -0700558 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) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700574 descriptor = jbd2_journal_get_descriptor_buffer(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700575 if (!descriptor)
576 return;
577 header = (journal_header_t *) &jh2bh(descriptor)->b_data[0];
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700578 header->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER);
579 header->h_blocktype = cpu_to_be32(JBD2_REVOKE_BLOCK);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700580 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");
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700584 jbd2_journal_file_buffer(descriptor, transaction, BJ_LogCtl);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700585
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700586 offset = sizeof(jbd2_journal_revoke_header_t);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700587 *descriptorp = descriptor;
588 }
589
Zach Brownb517bea2006-10-11 01:21:08 -0700590 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
Dave Kleikamp470decc2006-10-11 01:20:57 -0700601 *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
611static void flush_descriptor(journal_t *journal,
612 struct journal_head *descriptor,
613 int offset)
614{
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700615 jbd2_journal_revoke_header_t *header;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700616 struct buffer_head *bh = jh2bh(descriptor);
617
618 if (is_journal_aborted(journal)) {
619 put_bh(bh);
620 return;
621 }
622
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700623 header = (jbd2_journal_revoke_header_t *) jh2bh(descriptor)->b_data;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700624 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
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700654int jbd2_journal_set_revoke(journal_t *journal,
Mingming Cao18eba7a2006-10-11 01:21:13 -0700655 unsigned long long blocknr,
Dave Kleikamp470decc2006-10-11 01:20:57 -0700656 tid_t sequence)
657{
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700658 struct jbd2_revoke_record_s *record;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700659
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
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700678int jbd2_journal_test_revoke(journal_t *journal,
Mingming Cao18eba7a2006-10-11 01:21:13 -0700679 unsigned long long blocknr,
Dave Kleikamp470decc2006-10-11 01:20:57 -0700680 tid_t sequence)
681{
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700682 struct jbd2_revoke_record_s *record;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700683
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
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700697void jbd2_journal_clear_revoke(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700698{
699 int i;
700 struct list_head *hash_list;
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700701 struct jbd2_revoke_record_s *record;
702 struct jbd2_revoke_table_s *revoke;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700703
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)) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700709 record = (struct jbd2_revoke_record_s*) hash_list->next;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700710 list_del(&record->hash);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700711 kmem_cache_free(jbd2_revoke_record_cache, record);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700712 }
713 }
714}