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RevokeValid clear: no cached revoke status, need to look it up 53 * RevokeValid set, Revoked clear: 54 * buffer has not been revoked, and cancel_revoke 55 * need do nothing. 56 * RevokeValid set, Revoked set: 57 * buffer has been revoked. 58 */ 59 60#ifndef __KERNEL__ 61#include "jfs_user.h" 62#else 63#include 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 72static struct kmem_cache *jbd2_revoke_record_cache; 73static struct kmem_cache *jbd2_revoke_table_cache; 74 75/* Each revoke record represents one single revoked block. During 76 journal replay, this involves recording the transaction ID of the 77 last transaction to revoke this block. */ 78 79struct jbd2_revoke_record_s 80{ 81 struct list_head hash; 82 tid_t sequence; /* Used for recovery only */ 83 unsigned long long blocknr; 84}; 85 86 87/* The revoke table is just a simple hash table of revoke records. */ 88struct jbd2_revoke_table_s 89{ 90 /* It is conceivable that we might want a larger hash table 91 * for recovery. Must be a power of two. */ 92 int hash_size; 93 int hash_shift; 94 struct list_head *hash_table; 95}; 96 97 98#ifdef __KERNEL__ 99static void write_one_revoke_record(journal_t *, transaction_t *, 100 struct journal_head **, int *, 101 struct jbd2_revoke_record_s *); 102static void flush_descriptor(journal_t *, struct journal_head *, int); 103#endif 104 105/* Utility functions to maintain the revoke table */ 106 107/* Borrowed from buffer.c: this is a tried and tested block hash function */ 108static inline int hash(journal_t *journal, unsigned long long block) 109{ 110 struct jbd2_revoke_table_s *table = journal->j_revoke; 111 int hash_shift = table->hash_shift; 112 int hash = (int)block ^ (int)((block >> 31) >> 1); 113 114 return ((hash << (hash_shift - 6)) ^ 115 (hash >> 13) ^ 116 (hash << (hash_shift - 12))) & (table->hash_size - 1); 117} 118 119static int insert_revoke_hash(journal_t *journal, unsigned long long blocknr, 120 tid_t seq) 121{ 122 struct list_head *hash_list; 123 struct jbd2_revoke_record_s *record; 124 125repeat: 126 record = kmem_cache_alloc(jbd2_revoke_record_cache, GFP_NOFS); 127 if (!record) 128 goto oom; 129 130 record->sequence = seq; 131 record->blocknr = blocknr; 132 hash_list = &journal->j_revoke->hash_table[hash(journal, blocknr)]; 133 spin_lock(&journal->j_revoke_lock); 134 list_add(&record->hash, hash_list); 135 spin_unlock(&journal->j_revoke_lock); 136 return 0; 137 138oom: 139 if (!journal_oom_retry) 140 return -ENOMEM; 141 jbd_debug(1, "ENOMEM in %s, retrying\n", __FUNCTION__); 142 yield(); 143 goto repeat; 144} 145 146/* Find a revoke record in the journal's hash table. */ 147 148static struct jbd2_revoke_record_s *find_revoke_record(journal_t *journal, 149 unsigned long long blocknr) 150{ 151 struct list_head *hash_list; 152 struct jbd2_revoke_record_s *record; 153 154 hash_list = &journal->j_revoke->hash_table[hash(journal, blocknr)]; 155 156 spin_lock(&journal->j_revoke_lock); 157 record = (struct jbd2_revoke_record_s *) hash_list->next; 158 while (&(record->hash) != hash_list) { 159 if (record->blocknr == blocknr) { 160 spin_unlock(&journal->j_revoke_lock); 161 return record; 162 } 163 record = (struct jbd2_revoke_record_s *) record->hash.next; 164 } 165 spin_unlock(&journal->j_revoke_lock); 166 return NULL; 167} 168 169int __init jbd2_journal_init_revoke_caches(void) 170{ 171 jbd2_revoke_record_cache = kmem_cache_create("jbd2_revoke_record", 172 sizeof(struct jbd2_revoke_record_s), 173 0, SLAB_HWCACHE_ALIGN, NULL, NULL); 174 if (jbd2_revoke_record_cache == 0) 175 return -ENOMEM; 176 177 jbd2_revoke_table_cache = kmem_cache_create("jbd2_revoke_table", 178 sizeof(struct jbd2_revoke_table_s), 179 0, 0, NULL, NULL); 180 if (jbd2_revoke_table_cache == 0) { 181 kmem_cache_destroy(jbd2_revoke_record_cache); 182 jbd2_revoke_record_cache = NULL; 183 return -ENOMEM; 184 } 185 return 0; 186} 187 188void jbd2_journal_destroy_revoke_caches(void) 189{ 190 kmem_cache_destroy(jbd2_revoke_record_cache); 191 jbd2_revoke_record_cache = NULL; 192 kmem_cache_destroy(jbd2_revoke_table_cache); 193 jbd2_revoke_table_cache = NULL; 194} 195 196/* Initialise the revoke table for a given journal to a given size. */ 197 198int jbd2_journal_init_revoke(journal_t *journal, int hash_size) 199{ 200 int shift, tmp; 201 202 J_ASSERT (journal->j_revoke_table[0] == NULL); 203 204 shift = 0; 205 tmp = hash_size; 206 while((tmp >>= 1UL) != 0UL) 207 shift++; 208 209 journal->j_revoke_table[0] = kmem_cache_alloc(jbd2_revoke_table_cache, GFP_KERNEL); 210 if (!journal->j_revoke_table[0]) 211 return -ENOMEM; 212 journal->j_revoke = journal->j_revoke_table[0]; 213 214 /* Check that the hash_size is a power of two */ 215 J_ASSERT ((hash_size & (hash_size-1)) == 0); 216 217 journal->j_revoke->hash_size = hash_size; 218 219 journal->j_revoke->hash_shift = shift; 220 221 journal->j_revoke->hash_table = 222 kmalloc(hash_size * sizeof(struct list_head), GFP_KERNEL); 223 if (!journal->j_revoke->hash_table) { 224 kmem_cache_free(jbd2_revoke_table_cache, journal->j_revoke_table[0]); 225 journal->j_revoke = NULL; 226 return -ENOMEM; 227 } 228 229 for (tmp = 0; tmp < hash_size; tmp++) 230 INIT_LIST_HEAD(&journal->j_revoke->hash_table[tmp]); 231 232 journal->j_revoke_table[1] = kmem_cache_alloc(jbd2_revoke_table_cache, GFP_KERNEL); 233 if (!journal->j_revoke_table[1]) { 234 kfree(journal->j_revoke_table[0]->hash_table); 235 kmem_cache_free(jbd2_revoke_table_cache, journal->j_revoke_table[0]); 236 return -ENOMEM; 237 } 238 239 journal->j_revoke = journal->j_revoke_table[1]; 240 241 /* Check that the hash_size is a power of two */ 242 J_ASSERT ((hash_size & (hash_size-1)) == 0); 243 244 journal->j_revoke->hash_size = hash_size; 245 246 journal->j_revoke->hash_shift = shift; 247 248 journal->j_revoke->hash_table = 249 kmalloc(hash_size * sizeof(struct list_head), GFP_KERNEL); 250 if (!journal->j_revoke->hash_table) { 251 kfree(journal->j_revoke_table[0]->hash_table); 252 kmem_cache_free(jbd2_revoke_table_cache, journal->j_revoke_table[0]); 253 kmem_cache_free(jbd2_revoke_table_cache, journal->j_revoke_table[1]); 254 journal->j_revoke = NULL; 255 return -ENOMEM; 256 } 257 258 for (tmp = 0; tmp < hash_size; tmp++) 259 INIT_LIST_HEAD(&journal->j_revoke->hash_table[tmp]); 260 261 spin_lock_init(&journal->j_revoke_lock); 262 263 return 0; 264} 265 266/* Destoy a journal's revoke table. The table must already be empty! */ 267 268void jbd2_journal_destroy_revoke(journal_t *journal) 269{ 270 struct jbd2_revoke_table_s *table; 271 struct list_head *hash_list; 272 int i; 273 274 table = journal->j_revoke_table[0]; 275 if (!table) 276 return; 277 278 for (i=0; i<table->hash_size; i++) { 279 hash_list = &table->hash_table[i]; 280 J_ASSERT (list_empty(hash_list)); 281 } 282 283 kfree(table->hash_table); 284 kmem_cache_free(jbd2_revoke_table_cache, table); 285 journal->j_revoke = NULL; 286 287 table = journal->j_revoke_table[1]; 288 if (!table) 289 return; 290 291 for (i=0; i<table->hash_size; i++) { 292 hash_list = &table->hash_table[i]; 293 J_ASSERT (list_empty(hash_list)); 294 } 295 296 kfree(table->hash_table); 297 kmem_cache_free(jbd2_revoke_table_cache, table); 298 journal->j_revoke = NULL; 299} 300 301 302#ifdef __KERNEL__ 303 304/* 305 * jbd2_journal_revoke: revoke a given buffer_head from the journal. This 306 * prevents the block from being replayed during recovery if we take a 307 * crash after this current transaction commits. Any subsequent 308 * metadata writes of the buffer in this transaction cancel the 309 * revoke. 310 * 311 * Note that this call may block --- it is up to the caller to make 312 * sure that there are no further calls to journal_write_metadata 313 * before the revoke is complete. In ext3, this implies calling the 314 * revoke before clearing the block bitmap when we are deleting 315 * metadata. 316 * 317 * Revoke performs a jbd2_journal_forget on any buffer_head passed in as a 318 * parameter, but does _not_ forget the buffer_head if the bh was only 319 * found implicitly. 320 * 321 * bh_in may not be a journalled buffer - it may have come off 322 * the hash tables without an attached journal_head. 323 * 324 * If bh_in is non-zero, jbd2_journal_revoke() will decrement its b_count 325 * by one. 326 */ 327 328int jbd2_journal_revoke(handle_t *handle, unsigned long long blocknr, 329 struct buffer_head *bh_in) 330{ 331 struct buffer_head *bh = NULL; 332 journal_t *journal; 333 struct block_device *bdev; 334 int err; 335 336 might_sleep(); 337 if (bh_in) 338 BUFFER_TRACE(bh_in, "enter"); 339 340 journal = handle->h_transaction->t_journal; 341 if (!jbd2_journal_set_features(journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)){ 342 J_ASSERT (!"Cannot set revoke feature!"); 343 return -EINVAL; 344 } 345 346 bdev = journal->j_fs_dev; 347 bh = bh_in; 348 349 if (!bh) { 350 bh = __find_get_block(bdev, blocknr, journal->j_blocksize); 351 if (bh) 352 BUFFER_TRACE(bh, "found on hash"); 353 } 354#ifdef JBD_EXPENSIVE_CHECKING 355 else { 356 struct buffer_head *bh2; 357 358 /* If there is a different buffer_head lying around in 359 * memory anywhere... */ 360 bh2 = __find_get_block(bdev, blocknr, journal->j_blocksize); 361 if (bh2) { 362 /* ... and it has RevokeValid status... */ 363 if (bh2 != bh && buffer_revokevalid(bh2)) 364 /* ...then it better be revoked too, 365 * since it's illegal to create a revoke 366 * record against a buffer_head which is 367 * not marked revoked --- that would 368 * risk missing a subsequent revoke 369 * cancel. */ 370 J_ASSERT_BH(bh2, buffer_revoked(bh2)); 371 put_bh(bh2); 372 } 373 } 374#endif 375 376 /* We really ought not ever to revoke twice in a row without 377 first having the revoke cancelled: it's illegal to free a 378 block twice without allocating it in between! */ 379 if (bh) { 380 if (!J_EXPECT_BH(bh, !buffer_revoked(bh), 381 "inconsistent data on disk")) { 382 if (!bh_in) 383 brelse(bh); 384 return -EIO; 385 } 386 set_buffer_revoked(bh); 387 set_buffer_revokevalid(bh); 388 if (bh_in) { 389 BUFFER_TRACE(bh_in, "call jbd2_journal_forget"); 390 jbd2_journal_forget(handle, bh_in); 391 } else { 392 BUFFER_TRACE(bh, "call brelse"); 393 __brelse(bh); 394 } 395 } 396 397 jbd_debug(2, "insert revoke for block %llu, bh_in=%p\n",blocknr, bh_in); 398 err = insert_revoke_hash(journal, blocknr, 399 handle->h_transaction->t_tid); 400 BUFFER_TRACE(bh_in, "exit"); 401 return err; 402} 403 404/* 405 * Cancel an outstanding revoke. For use only internally by the 406 * journaling code (called from jbd2_journal_get_write_access). 407 * 408 * We trust buffer_revoked() on the buffer if the buffer is already 409 * being journaled: if there is no revoke pending on the buffer, then we 410 * don't do anything here. 411 * 412 * This would break if it were possible for a buffer to be revoked and 413 * discarded, and then reallocated within the same transaction. In such 414 * a case we would have lost the revoked bit, but when we arrived here 415 * the second time we would still have a pending revoke to cancel. So, 416 * do not trust the Revoked bit on buffers unless RevokeValid is also 417 * set. 418 * 419 * The caller must have the journal locked. 420 */ 421int jbd2_journal_cancel_revoke(handle_t *handle, struct journal_head *jh) 422{ 423 struct jbd2_revoke_record_s *record; 424 journal_t *journal = handle->h_transaction->t_journal; 425 int need_cancel; 426 int did_revoke = 0; /* akpm: debug */ 427 struct buffer_head *bh = jh2bh(jh); 428 429 jbd_debug(4, "journal_head %p, cancelling revoke\n", jh); 430 431 /* Is the existing Revoke bit valid? If so, we trust it, and 432 * only perform the full cancel if the revoke bit is set. If 433 * not, we can't trust the revoke bit, and we need to do the 434 * full search for a revoke record. */ 435 if (test_set_buffer_revokevalid(bh)) { 436 need_cancel = test_clear_buffer_revoked(bh); 437 } else { 438 need_cancel = 1; 439 clear_buffer_revoked(bh); 440 } 441 442 if (need_cancel) { 443 record = find_revoke_record(journal, bh->b_blocknr); 444 if (record) { 445 jbd_debug(4, "cancelled existing revoke on " 446 "blocknr %llu\n", (unsigned long long)bh->b_blocknr); 447 spin_lock(&journal->j_revoke_lock); 448 list_del(&record->hash); 449 spin_unlock(&journal->j_revoke_lock); 450 kmem_cache_free(jbd2_revoke_record_cache, record); 451 did_revoke = 1; 452 } 453 } 454 455#ifdef JBD_EXPENSIVE_CHECKING 456 /* There better not be one left behind by now! */ 457 record = find_revoke_record(journal, bh->b_blocknr); 458 J_ASSERT_JH(jh, record == NULL); 459#endif 460 461 /* Finally, have we just cleared revoke on an unhashed 462 * buffer_head? If so, we'd better make sure we clear the 463 * revoked status on any hashed alias too, otherwise the revoke 464 * state machine will get very upset later on. */ 465 if (need_cancel) { 466 struct buffer_head *bh2; 467 bh2 = __find_get_block(bh->b_bdev, bh->b_blocknr, bh->b_size); 468 if (bh2) { 469 if (bh2 != bh) 470 clear_buffer_revoked(bh2); 471 __brelse(bh2); 472 } 473 } 474 return did_revoke; 475} 476 477/* journal_switch_revoke table select j_revoke for next transaction 478 * we do not want to suspend any processing until all revokes are 479 * written -bzzz 480 */ 481void jbd2_journal_switch_revoke_table(journal_t *journal) 482{ 483 int i; 484 485 if (journal->j_revoke == journal->j_revoke_table[0]) 486 journal->j_revoke = journal->j_revoke_table[1]; 487 else 488 journal->j_revoke = journal->j_revoke_table[0]; 489 490 for (i = 0; i < journal->j_revoke->hash_size; i++) 491 INIT_LIST_HEAD(&journal->j_revoke->hash_table[i]); 492} 493 494/* 495 * Write revoke records to the journal for all entries in the current 496 * revoke hash, deleting the entries as we go. 497 * 498 * Called with the journal lock held. 499 */ 500 501void jbd2_journal_write_revoke_records(journal_t *journal, 502 transaction_t *transaction) 503{ 504 struct journal_head *descriptor; 505 struct jbd2_revoke_record_s *record; 506 struct jbd2_revoke_table_s *revoke; 507 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)) { 522 record = (struct jbd2_revoke_record_s *) 523 hash_list->next; 524 write_one_revoke_record(journal, transaction, 525 &descriptor, &offset, 526 record); 527 count++; 528 list_del(&record->hash); 529 kmem_cache_free(jbd2_revoke_record_cache, record); 530 } 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, 546 struct jbd2_revoke_record_s *record) 547{ 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 554 jbd2_journal_write_revoke_records in order to free all of the 555 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) { 571 descriptor = jbd2_journal_get_descriptor_buffer(journal); 572 if (!descriptor) 573 return; 574 header = (journal_header_t *) &jh2bh(descriptor)->b_data[0]; 575 header->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER); 576 header->h_blocktype = cpu_to_be32(JBD2_REVOKE_BLOCK); 577 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"); 581 jbd2_journal_file_buffer(descriptor, transaction, BJ_LogCtl); 582 583 offset = sizeof(jbd2_journal_revoke_header_t); 584 *descriptorp = descriptor; 585 } 586 587 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 } 597 598 *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{ 612 jbd2_journal_revoke_header_t *header; 613 struct buffer_head *bh = jh2bh(descriptor); 614 615 if (is_journal_aborted(journal)) { 616 put_bh(bh); 617 return; 618 } 619 620 header = (jbd2_journal_revoke_header_t *) jh2bh(descriptor)->b_data; 621 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 651int jbd2_journal_set_revoke(journal_t *journal, 652 unsigned long long blocknr, 653 tid_t sequence) 654{ 655 struct jbd2_revoke_record_s *record; 656 657 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 675int jbd2_journal_test_revoke(journal_t *journal, 676 unsigned long long blocknr, 677 tid_t sequence) 678{ 679 struct jbd2_revoke_record_s *record; 680 681 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 694void jbd2_journal_clear_revoke(journal_t *journal) 695{ 696 int i; 697 struct list_head *hash_list; 698 struct jbd2_revoke_record_s *record; 699 struct jbd2_revoke_table_s *revoke; 700 701 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)) { 706 record = (struct jbd2_revoke_record_s*) hash_list->next; 707 list_del(&record->hash); 708 kmem_cache_free(jbd2_revoke_record_cache, record); 709 } 710 } 711} 712