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clear: no cached revoke status, need to look it up 53 * RevokeValid set, Revoked clear: 54 * buffer has not been revoked, and cancel_revoke 55 * need do nothing. 56 * RevokeValid set, Revoked set: 57 * buffer has been revoked. 58 */ 59 60 #ifndef __KERNEL__ 61 #include "jfs_user.h" 62 #else 63 #include 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