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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.
Jan Kara86db97c2009-03-27 17:20:40 -040058 *
59 * Locking rules:
60 * We keep two hash tables of revoke records. One hashtable belongs to the
61 * running transaction (is pointed to by journal->j_revoke), the other one
62 * belongs to the committing transaction. Accesses to the second hash table
63 * happen only from the kjournald and no other thread touches this table. Also
64 * journal_switch_revoke_table() which switches which hashtable belongs to the
65 * running and which to the committing transaction is called only from
66 * kjournald. Therefore we need no locks when accessing the hashtable belonging
67 * to the committing transaction.
68 *
69 * All users operating on the hash table belonging to the running transaction
70 * have a handle to the transaction. Therefore they are safe from kjournald
71 * switching hash tables under them. For operations on the lists of entries in
72 * the hash table j_revoke_lock is used.
73 *
74 * Finally, also replay code uses the hash tables but at this moment noone else
75 * can touch them (filesystem isn't mounted yet) and hence no locking is
76 * needed.
Dave Kleikamp470decc2006-10-11 01:20:57 -070077 */
78
79#ifndef __KERNEL__
80#include "jfs_user.h"
81#else
82#include <linux/time.h>
83#include <linux/fs.h>
Mingming Caof7f4bcc2006-10-11 01:20:59 -070084#include <linux/jbd2.h>
Dave Kleikamp470decc2006-10-11 01:20:57 -070085#include <linux/errno.h>
86#include <linux/slab.h>
87#include <linux/list.h>
Dave Kleikamp470decc2006-10-11 01:20:57 -070088#include <linux/init.h>
89#endif
vignesh babuf4823942007-07-15 23:41:17 -070090#include <linux/log2.h>
Dave Kleikamp470decc2006-10-11 01:20:57 -070091
Christoph Lametere18b8902006-12-06 20:33:20 -080092static struct kmem_cache *jbd2_revoke_record_cache;
93static struct kmem_cache *jbd2_revoke_table_cache;
Dave Kleikamp470decc2006-10-11 01:20:57 -070094
95/* Each revoke record represents one single revoked block. During
96 journal replay, this involves recording the transaction ID of the
97 last transaction to revoke this block. */
98
Mingming Caof7f4bcc2006-10-11 01:20:59 -070099struct jbd2_revoke_record_s
Dave Kleikamp470decc2006-10-11 01:20:57 -0700100{
101 struct list_head hash;
102 tid_t sequence; /* Used for recovery only */
Mingming Cao18eba7a2006-10-11 01:21:13 -0700103 unsigned long long blocknr;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700104};
105
106
107/* The revoke table is just a simple hash table of revoke records. */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700108struct jbd2_revoke_table_s
Dave Kleikamp470decc2006-10-11 01:20:57 -0700109{
110 /* It is conceivable that we might want a larger hash table
111 * for recovery. Must be a power of two. */
112 int hash_size;
113 int hash_shift;
114 struct list_head *hash_table;
115};
116
117
118#ifdef __KERNEL__
119static void write_one_revoke_record(journal_t *, transaction_t *,
120 struct journal_head **, int *,
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700121 struct jbd2_revoke_record_s *);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700122static void flush_descriptor(journal_t *, struct journal_head *, int);
123#endif
124
125/* Utility functions to maintain the revoke table */
126
127/* Borrowed from buffer.c: this is a tried and tested block hash function */
Mingming Cao18eba7a2006-10-11 01:21:13 -0700128static inline int hash(journal_t *journal, unsigned long long block)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700129{
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700130 struct jbd2_revoke_table_s *table = journal->j_revoke;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700131 int hash_shift = table->hash_shift;
Mingming Cao29971762006-10-11 01:21:09 -0700132 int hash = (int)block ^ (int)((block >> 31) >> 1);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700133
Mingming Cao29971762006-10-11 01:21:09 -0700134 return ((hash << (hash_shift - 6)) ^
135 (hash >> 13) ^
136 (hash << (hash_shift - 12))) & (table->hash_size - 1);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700137}
138
Mingming Cao18eba7a2006-10-11 01:21:13 -0700139static int insert_revoke_hash(journal_t *journal, unsigned long long blocknr,
Dave Kleikamp470decc2006-10-11 01:20:57 -0700140 tid_t seq)
141{
142 struct list_head *hash_list;
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700143 struct jbd2_revoke_record_s *record;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700144
145repeat:
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700146 record = kmem_cache_alloc(jbd2_revoke_record_cache, GFP_NOFS);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700147 if (!record)
148 goto oom;
149
150 record->sequence = seq;
151 record->blocknr = blocknr;
152 hash_list = &journal->j_revoke->hash_table[hash(journal, blocknr)];
153 spin_lock(&journal->j_revoke_lock);
154 list_add(&record->hash, hash_list);
155 spin_unlock(&journal->j_revoke_lock);
156 return 0;
157
158oom:
159 if (!journal_oom_retry)
160 return -ENOMEM;
Harvey Harrison329d2912008-04-17 10:38:59 -0400161 jbd_debug(1, "ENOMEM in %s, retrying\n", __func__);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700162 yield();
163 goto repeat;
164}
165
166/* Find a revoke record in the journal's hash table. */
167
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700168static struct jbd2_revoke_record_s *find_revoke_record(journal_t *journal,
Mingming Cao18eba7a2006-10-11 01:21:13 -0700169 unsigned long long blocknr)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700170{
171 struct list_head *hash_list;
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700172 struct jbd2_revoke_record_s *record;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700173
174 hash_list = &journal->j_revoke->hash_table[hash(journal, blocknr)];
175
176 spin_lock(&journal->j_revoke_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700177 record = (struct jbd2_revoke_record_s *) hash_list->next;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700178 while (&(record->hash) != hash_list) {
179 if (record->blocknr == blocknr) {
180 spin_unlock(&journal->j_revoke_lock);
181 return record;
182 }
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700183 record = (struct jbd2_revoke_record_s *) record->hash.next;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700184 }
185 spin_unlock(&journal->j_revoke_lock);
186 return NULL;
187}
188
Duane Griffin9fa27c82008-04-28 09:40:00 -0400189void jbd2_journal_destroy_revoke_caches(void)
190{
191 if (jbd2_revoke_record_cache) {
192 kmem_cache_destroy(jbd2_revoke_record_cache);
193 jbd2_revoke_record_cache = NULL;
194 }
195 if (jbd2_revoke_table_cache) {
196 kmem_cache_destroy(jbd2_revoke_table_cache);
197 jbd2_revoke_table_cache = NULL;
198 }
199}
200
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700201int __init jbd2_journal_init_revoke_caches(void)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700202{
Duane Griffin9fa27c82008-04-28 09:40:00 -0400203 J_ASSERT(!jbd2_revoke_record_cache);
204 J_ASSERT(!jbd2_revoke_table_cache);
205
Johann Lombardia920e942006-10-11 01:21:00 -0700206 jbd2_revoke_record_cache = kmem_cache_create("jbd2_revoke_record",
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700207 sizeof(struct jbd2_revoke_record_s),
Mingming Cao77160952008-01-28 23:58:27 -0500208 0,
209 SLAB_HWCACHE_ALIGN|SLAB_TEMPORARY,
210 NULL);
Al Viro1076d172008-03-29 03:07:18 +0000211 if (!jbd2_revoke_record_cache)
Duane Griffin9fa27c82008-04-28 09:40:00 -0400212 goto record_cache_failure;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700213
Johann Lombardia920e942006-10-11 01:21:00 -0700214 jbd2_revoke_table_cache = kmem_cache_create("jbd2_revoke_table",
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700215 sizeof(struct jbd2_revoke_table_s),
Mingming Cao77160952008-01-28 23:58:27 -0500216 0, SLAB_TEMPORARY, NULL);
Duane Griffin9fa27c82008-04-28 09:40:00 -0400217 if (!jbd2_revoke_table_cache)
218 goto table_cache_failure;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700219 return 0;
Duane Griffin9fa27c82008-04-28 09:40:00 -0400220table_cache_failure:
221 jbd2_journal_destroy_revoke_caches();
222record_cache_failure:
223 return -ENOMEM;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700224}
225
Duane Griffin83c49522008-04-17 10:38:59 -0400226static struct jbd2_revoke_table_s *jbd2_journal_init_revoke_table(int hash_size)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700227{
Duane Griffin83c49522008-04-17 10:38:59 -0400228 int shift = 0;
229 int tmp = hash_size;
230 struct jbd2_revoke_table_s *table;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700231
Duane Griffin83c49522008-04-17 10:38:59 -0400232 table = kmem_cache_alloc(jbd2_revoke_table_cache, GFP_KERNEL);
233 if (!table)
234 goto out;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700235
Dave Kleikamp470decc2006-10-11 01:20:57 -0700236 while((tmp >>= 1UL) != 0UL)
237 shift++;
238
Duane Griffin83c49522008-04-17 10:38:59 -0400239 table->hash_size = hash_size;
240 table->hash_shift = shift;
241 table->hash_table =
Dave Kleikamp470decc2006-10-11 01:20:57 -0700242 kmalloc(hash_size * sizeof(struct list_head), GFP_KERNEL);
Duane Griffin83c49522008-04-17 10:38:59 -0400243 if (!table->hash_table) {
244 kmem_cache_free(jbd2_revoke_table_cache, table);
245 table = NULL;
246 goto out;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700247 }
248
249 for (tmp = 0; tmp < hash_size; tmp++)
Duane Griffin83c49522008-04-17 10:38:59 -0400250 INIT_LIST_HEAD(&table->hash_table[tmp]);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700251
Duane Griffin83c49522008-04-17 10:38:59 -0400252out:
253 return table;
254}
255
256static void jbd2_journal_destroy_revoke_table(struct jbd2_revoke_table_s *table)
257{
258 int i;
259 struct list_head *hash_list;
260
261 for (i = 0; i < table->hash_size; i++) {
262 hash_list = &table->hash_table[i];
263 J_ASSERT(list_empty(hash_list));
Dave Kleikamp470decc2006-10-11 01:20:57 -0700264 }
265
Duane Griffin83c49522008-04-17 10:38:59 -0400266 kfree(table->hash_table);
267 kmem_cache_free(jbd2_revoke_table_cache, table);
268}
269
270/* Initialise the revoke table for a given journal to a given size. */
271int jbd2_journal_init_revoke(journal_t *journal, int hash_size)
272{
273 J_ASSERT(journal->j_revoke_table[0] == NULL);
274 J_ASSERT(is_power_of_2(hash_size));
275
276 journal->j_revoke_table[0] = jbd2_journal_init_revoke_table(hash_size);
277 if (!journal->j_revoke_table[0])
278 goto fail0;
279
280 journal->j_revoke_table[1] = jbd2_journal_init_revoke_table(hash_size);
281 if (!journal->j_revoke_table[1])
282 goto fail1;
283
Dave Kleikamp470decc2006-10-11 01:20:57 -0700284 journal->j_revoke = journal->j_revoke_table[1];
285
Dave Kleikamp470decc2006-10-11 01:20:57 -0700286 spin_lock_init(&journal->j_revoke_lock);
287
288 return 0;
Duane Griffin83c49522008-04-17 10:38:59 -0400289
290fail1:
291 jbd2_journal_destroy_revoke_table(journal->j_revoke_table[0]);
292fail0:
293 return -ENOMEM;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700294}
295
Duane Griffin83c49522008-04-17 10:38:59 -0400296/* Destroy a journal's revoke table. The table must already be empty! */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700297void jbd2_journal_destroy_revoke(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700298{
Dave Kleikamp470decc2006-10-11 01:20:57 -0700299 journal->j_revoke = NULL;
Duane Griffin83c49522008-04-17 10:38:59 -0400300 if (journal->j_revoke_table[0])
301 jbd2_journal_destroy_revoke_table(journal->j_revoke_table[0]);
302 if (journal->j_revoke_table[1])
303 jbd2_journal_destroy_revoke_table(journal->j_revoke_table[1]);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700304}
305
306
307#ifdef __KERNEL__
308
309/*
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700310 * jbd2_journal_revoke: revoke a given buffer_head from the journal. This
Dave Kleikamp470decc2006-10-11 01:20:57 -0700311 * prevents the block from being replayed during recovery if we take a
312 * crash after this current transaction commits. Any subsequent
313 * metadata writes of the buffer in this transaction cancel the
314 * revoke.
315 *
316 * Note that this call may block --- it is up to the caller to make
317 * sure that there are no further calls to journal_write_metadata
318 * before the revoke is complete. In ext3, this implies calling the
319 * revoke before clearing the block bitmap when we are deleting
320 * metadata.
321 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700322 * Revoke performs a jbd2_journal_forget on any buffer_head passed in as a
Dave Kleikamp470decc2006-10-11 01:20:57 -0700323 * parameter, but does _not_ forget the buffer_head if the bh was only
324 * found implicitly.
325 *
326 * bh_in may not be a journalled buffer - it may have come off
327 * the hash tables without an attached journal_head.
328 *
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700329 * If bh_in is non-zero, jbd2_journal_revoke() will decrement its b_count
Dave Kleikamp470decc2006-10-11 01:20:57 -0700330 * by one.
331 */
332
Mingming Cao18eba7a2006-10-11 01:21:13 -0700333int jbd2_journal_revoke(handle_t *handle, unsigned long long blocknr,
Dave Kleikamp470decc2006-10-11 01:20:57 -0700334 struct buffer_head *bh_in)
335{
336 struct buffer_head *bh = NULL;
337 journal_t *journal;
338 struct block_device *bdev;
339 int err;
340
341 might_sleep();
342 if (bh_in)
343 BUFFER_TRACE(bh_in, "enter");
344
345 journal = handle->h_transaction->t_journal;
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700346 if (!jbd2_journal_set_features(journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)){
Dave Kleikamp470decc2006-10-11 01:20:57 -0700347 J_ASSERT (!"Cannot set revoke feature!");
348 return -EINVAL;
349 }
350
351 bdev = journal->j_fs_dev;
352 bh = bh_in;
353
354 if (!bh) {
355 bh = __find_get_block(bdev, blocknr, journal->j_blocksize);
356 if (bh)
357 BUFFER_TRACE(bh, "found on hash");
358 }
Mingming Caocd02ff02007-10-16 18:38:25 -0400359#ifdef JBD2_EXPENSIVE_CHECKING
Dave Kleikamp470decc2006-10-11 01:20:57 -0700360 else {
361 struct buffer_head *bh2;
362
363 /* If there is a different buffer_head lying around in
364 * memory anywhere... */
365 bh2 = __find_get_block(bdev, blocknr, journal->j_blocksize);
366 if (bh2) {
367 /* ... and it has RevokeValid status... */
368 if (bh2 != bh && buffer_revokevalid(bh2))
369 /* ...then it better be revoked too,
370 * since it's illegal to create a revoke
371 * record against a buffer_head which is
372 * not marked revoked --- that would
373 * risk missing a subsequent revoke
374 * cancel. */
375 J_ASSERT_BH(bh2, buffer_revoked(bh2));
376 put_bh(bh2);
377 }
378 }
379#endif
380
381 /* We really ought not ever to revoke twice in a row without
382 first having the revoke cancelled: it's illegal to free a
383 block twice without allocating it in between! */
384 if (bh) {
385 if (!J_EXPECT_BH(bh, !buffer_revoked(bh),
386 "inconsistent data on disk")) {
387 if (!bh_in)
388 brelse(bh);
389 return -EIO;
390 }
391 set_buffer_revoked(bh);
392 set_buffer_revokevalid(bh);
393 if (bh_in) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700394 BUFFER_TRACE(bh_in, "call jbd2_journal_forget");
395 jbd2_journal_forget(handle, bh_in);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700396 } else {
397 BUFFER_TRACE(bh, "call brelse");
398 __brelse(bh);
399 }
400 }
401
Mingming Cao29971762006-10-11 01:21:09 -0700402 jbd_debug(2, "insert revoke for block %llu, bh_in=%p\n",blocknr, bh_in);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700403 err = insert_revoke_hash(journal, blocknr,
404 handle->h_transaction->t_tid);
405 BUFFER_TRACE(bh_in, "exit");
406 return err;
407}
408
409/*
410 * Cancel an outstanding revoke. For use only internally by the
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700411 * journaling code (called from jbd2_journal_get_write_access).
Dave Kleikamp470decc2006-10-11 01:20:57 -0700412 *
413 * We trust buffer_revoked() on the buffer if the buffer is already
414 * being journaled: if there is no revoke pending on the buffer, then we
415 * don't do anything here.
416 *
417 * This would break if it were possible for a buffer to be revoked and
418 * discarded, and then reallocated within the same transaction. In such
419 * a case we would have lost the revoked bit, but when we arrived here
420 * the second time we would still have a pending revoke to cancel. So,
421 * do not trust the Revoked bit on buffers unless RevokeValid is also
422 * set.
Dave Kleikamp470decc2006-10-11 01:20:57 -0700423 */
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.
Dave Kleikamp470decc2006-10-11 01:20:57 -0700500 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700501void jbd2_journal_write_revoke_records(journal_t *journal,
Dave Kleikamp470decc2006-10-11 01:20:57 -0700502 transaction_t *transaction)
503{
504 struct journal_head *descriptor;
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700505 struct jbd2_revoke_record_s *record;
506 struct jbd2_revoke_table_s *revoke;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700507 struct list_head *hash_list;
508 int i, offset, count;
509
510 descriptor = NULL;
511 offset = 0;
512 count = 0;
513
514 /* select revoke table for committing transaction */
515 revoke = journal->j_revoke == journal->j_revoke_table[0] ?
516 journal->j_revoke_table[1] : journal->j_revoke_table[0];
517
518 for (i = 0; i < revoke->hash_size; i++) {
519 hash_list = &revoke->hash_table[i];
520
521 while (!list_empty(hash_list)) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700522 record = (struct jbd2_revoke_record_s *)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700523 hash_list->next;
524 write_one_revoke_record(journal, transaction,
525 &descriptor, &offset,
526 record);
527 count++;
528 list_del(&record->hash);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700529 kmem_cache_free(jbd2_revoke_record_cache, record);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700530 }
531 }
532 if (descriptor)
533 flush_descriptor(journal, descriptor, offset);
534 jbd_debug(1, "Wrote %d revoke records\n", count);
535}
536
537/*
538 * Write out one revoke record. We need to create a new descriptor
539 * block if the old one is full or if we have not already created one.
540 */
541
542static void write_one_revoke_record(journal_t *journal,
543 transaction_t *transaction,
544 struct journal_head **descriptorp,
545 int *offsetp,
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700546 struct jbd2_revoke_record_s *record)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700547{
548 struct journal_head *descriptor;
549 int offset;
550 journal_header_t *header;
551
552 /* If we are already aborting, this all becomes a noop. We
553 still need to go round the loop in
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700554 jbd2_journal_write_revoke_records in order to free all of the
Dave Kleikamp470decc2006-10-11 01:20:57 -0700555 revoke records: only the IO to the journal is omitted. */
556 if (is_journal_aborted(journal))
557 return;
558
559 descriptor = *descriptorp;
560 offset = *offsetp;
561
562 /* Make sure we have a descriptor with space left for the record */
563 if (descriptor) {
564 if (offset == journal->j_blocksize) {
565 flush_descriptor(journal, descriptor, offset);
566 descriptor = NULL;
567 }
568 }
569
570 if (!descriptor) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700571 descriptor = jbd2_journal_get_descriptor_buffer(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700572 if (!descriptor)
573 return;
574 header = (journal_header_t *) &jh2bh(descriptor)->b_data[0];
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700575 header->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER);
576 header->h_blocktype = cpu_to_be32(JBD2_REVOKE_BLOCK);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700577 header->h_sequence = cpu_to_be32(transaction->t_tid);
578
579 /* Record it so that we can wait for IO completion later */
580 JBUFFER_TRACE(descriptor, "file as BJ_LogCtl");
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700581 jbd2_journal_file_buffer(descriptor, transaction, BJ_LogCtl);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700582
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700583 offset = sizeof(jbd2_journal_revoke_header_t);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700584 *descriptorp = descriptor;
585 }
586
Zach Brownb517bea2006-10-11 01:21:08 -0700587 if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT)) {
588 * ((__be64 *)(&jh2bh(descriptor)->b_data[offset])) =
589 cpu_to_be64(record->blocknr);
590 offset += 8;
591
592 } else {
593 * ((__be32 *)(&jh2bh(descriptor)->b_data[offset])) =
594 cpu_to_be32(record->blocknr);
595 offset += 4;
596 }
597
Dave Kleikamp470decc2006-10-11 01:20:57 -0700598 *offsetp = offset;
599}
600
601/*
602 * Flush a revoke descriptor out to the journal. If we are aborting,
603 * this is a noop; otherwise we are generating a buffer which needs to
604 * be waited for during commit, so it has to go onto the appropriate
605 * journal buffer list.
606 */
607
608static void flush_descriptor(journal_t *journal,
609 struct journal_head *descriptor,
610 int offset)
611{
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700612 jbd2_journal_revoke_header_t *header;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700613 struct buffer_head *bh = jh2bh(descriptor);
614
615 if (is_journal_aborted(journal)) {
616 put_bh(bh);
617 return;
618 }
619
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700620 header = (jbd2_journal_revoke_header_t *) jh2bh(descriptor)->b_data;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700621 header->r_count = cpu_to_be32(offset);
622 set_buffer_jwrite(bh);
623 BUFFER_TRACE(bh, "write");
624 set_buffer_dirty(bh);
625 ll_rw_block(SWRITE, 1, &bh);
626}
627#endif
628
629/*
630 * Revoke support for recovery.
631 *
632 * Recovery needs to be able to:
633 *
634 * record all revoke records, including the tid of the latest instance
635 * of each revoke in the journal
636 *
637 * check whether a given block in a given transaction should be replayed
638 * (ie. has not been revoked by a revoke record in that or a subsequent
639 * transaction)
640 *
641 * empty the revoke table after recovery.
642 */
643
644/*
645 * First, setting revoke records. We create a new revoke record for
646 * every block ever revoked in the log as we scan it for recovery, and
647 * we update the existing records if we find multiple revokes for a
648 * single block.
649 */
650
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700651int jbd2_journal_set_revoke(journal_t *journal,
Mingming Cao18eba7a2006-10-11 01:21:13 -0700652 unsigned long long blocknr,
Dave Kleikamp470decc2006-10-11 01:20:57 -0700653 tid_t sequence)
654{
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700655 struct jbd2_revoke_record_s *record;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700656
657 record = find_revoke_record(journal, blocknr);
658 if (record) {
659 /* If we have multiple occurrences, only record the
660 * latest sequence number in the hashed record */
661 if (tid_gt(sequence, record->sequence))
662 record->sequence = sequence;
663 return 0;
664 }
665 return insert_revoke_hash(journal, blocknr, sequence);
666}
667
668/*
669 * Test revoke records. For a given block referenced in the log, has
670 * that block been revoked? A revoke record with a given transaction
671 * sequence number revokes all blocks in that transaction and earlier
672 * ones, but later transactions still need replayed.
673 */
674
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700675int jbd2_journal_test_revoke(journal_t *journal,
Mingming Cao18eba7a2006-10-11 01:21:13 -0700676 unsigned long long blocknr,
Dave Kleikamp470decc2006-10-11 01:20:57 -0700677 tid_t sequence)
678{
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700679 struct jbd2_revoke_record_s *record;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700680
681 record = find_revoke_record(journal, blocknr);
682 if (!record)
683 return 0;
684 if (tid_gt(sequence, record->sequence))
685 return 0;
686 return 1;
687}
688
689/*
690 * Finally, once recovery is over, we need to clear the revoke table so
691 * that it can be reused by the running filesystem.
692 */
693
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700694void jbd2_journal_clear_revoke(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700695{
696 int i;
697 struct list_head *hash_list;
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700698 struct jbd2_revoke_record_s *record;
699 struct jbd2_revoke_table_s *revoke;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700700
701 revoke = journal->j_revoke;
702
703 for (i = 0; i < revoke->hash_size; i++) {
704 hash_list = &revoke->hash_table[i];
705 while (!list_empty(hash_list)) {
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700706 record = (struct jbd2_revoke_record_s*) hash_list->next;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700707 list_del(&record->hash);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700708 kmem_cache_free(jbd2_revoke_record_cache, record);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700709 }
710 }
711}