Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
Uwe Kleine-König | 5886269 | 2007-05-09 07:51:49 +0200 | [diff] [blame] | 2 | * linux/fs/jbd/revoke.c |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 3 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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: |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 18 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | * + Commit: during commit we write the entire list of the current |
| 20 | * transaction's revoked blocks to the journal |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 21 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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: |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 32 | * The desired end result is the journaling of the new block, so we |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | * |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 44 | * Block is revoked and then written as data: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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: |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 57 | * buffer has been revoked. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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/jbd.h> |
| 66 | #include <linux/errno.h> |
| 67 | #include <linux/slab.h> |
| 68 | #include <linux/list.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 69 | #include <linux/init.h> |
| 70 | #endif |
| 71 | |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 72 | static struct kmem_cache *revoke_record_cache; |
| 73 | static struct kmem_cache *revoke_table_cache; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 79 | struct jbd_revoke_record_s |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 80 | { |
| 81 | struct list_head hash; |
| 82 | tid_t sequence; /* Used for recovery only */ |
| 83 | unsigned long blocknr; |
| 84 | }; |
| 85 | |
| 86 | |
| 87 | /* The revoke table is just a simple hash table of revoke records. */ |
| 88 | struct jbd_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. */ |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 92 | int hash_size; |
| 93 | int hash_shift; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 94 | struct list_head *hash_table; |
| 95 | }; |
| 96 | |
| 97 | |
| 98 | #ifdef __KERNEL__ |
| 99 | static void write_one_revoke_record(journal_t *, transaction_t *, |
| 100 | struct journal_head **, int *, |
| 101 | struct jbd_revoke_record_s *); |
| 102 | static 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 */ |
| 108 | static inline int hash(journal_t *journal, unsigned long block) |
| 109 | { |
| 110 | struct jbd_revoke_table_s *table = journal->j_revoke; |
| 111 | int hash_shift = table->hash_shift; |
| 112 | |
| 113 | return ((block << (hash_shift - 6)) ^ |
| 114 | (block >> 13) ^ |
| 115 | (block << (hash_shift - 12))) & (table->hash_size - 1); |
| 116 | } |
| 117 | |
Adrian Bunk | 022a4a7 | 2005-09-06 15:16:41 -0700 | [diff] [blame] | 118 | static int insert_revoke_hash(journal_t *journal, unsigned long blocknr, |
| 119 | tid_t seq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | { |
| 121 | struct list_head *hash_list; |
| 122 | struct jbd_revoke_record_s *record; |
| 123 | |
| 124 | repeat: |
| 125 | record = kmem_cache_alloc(revoke_record_cache, GFP_NOFS); |
| 126 | if (!record) |
| 127 | goto oom; |
| 128 | |
| 129 | record->sequence = seq; |
| 130 | record->blocknr = blocknr; |
| 131 | hash_list = &journal->j_revoke->hash_table[hash(journal, blocknr)]; |
| 132 | spin_lock(&journal->j_revoke_lock); |
| 133 | list_add(&record->hash, hash_list); |
| 134 | spin_unlock(&journal->j_revoke_lock); |
| 135 | return 0; |
| 136 | |
| 137 | oom: |
| 138 | if (!journal_oom_retry) |
| 139 | return -ENOMEM; |
| 140 | jbd_debug(1, "ENOMEM in %s, retrying\n", __FUNCTION__); |
| 141 | yield(); |
| 142 | goto repeat; |
| 143 | } |
| 144 | |
| 145 | /* Find a revoke record in the journal's hash table. */ |
| 146 | |
| 147 | static struct jbd_revoke_record_s *find_revoke_record(journal_t *journal, |
| 148 | unsigned long blocknr) |
| 149 | { |
| 150 | struct list_head *hash_list; |
| 151 | struct jbd_revoke_record_s *record; |
| 152 | |
| 153 | hash_list = &journal->j_revoke->hash_table[hash(journal, blocknr)]; |
| 154 | |
| 155 | spin_lock(&journal->j_revoke_lock); |
| 156 | record = (struct jbd_revoke_record_s *) hash_list->next; |
| 157 | while (&(record->hash) != hash_list) { |
| 158 | if (record->blocknr == blocknr) { |
| 159 | spin_unlock(&journal->j_revoke_lock); |
| 160 | return record; |
| 161 | } |
| 162 | record = (struct jbd_revoke_record_s *) record->hash.next; |
| 163 | } |
| 164 | spin_unlock(&journal->j_revoke_lock); |
| 165 | return NULL; |
| 166 | } |
| 167 | |
| 168 | int __init journal_init_revoke_caches(void) |
| 169 | { |
| 170 | revoke_record_cache = kmem_cache_create("revoke_record", |
| 171 | sizeof(struct jbd_revoke_record_s), |
| 172 | 0, SLAB_HWCACHE_ALIGN, NULL, NULL); |
| 173 | if (revoke_record_cache == 0) |
| 174 | return -ENOMEM; |
| 175 | |
| 176 | revoke_table_cache = kmem_cache_create("revoke_table", |
| 177 | sizeof(struct jbd_revoke_table_s), |
| 178 | 0, 0, NULL, NULL); |
| 179 | if (revoke_table_cache == 0) { |
| 180 | kmem_cache_destroy(revoke_record_cache); |
| 181 | revoke_record_cache = NULL; |
| 182 | return -ENOMEM; |
| 183 | } |
| 184 | return 0; |
| 185 | } |
| 186 | |
| 187 | void journal_destroy_revoke_caches(void) |
| 188 | { |
| 189 | kmem_cache_destroy(revoke_record_cache); |
| 190 | revoke_record_cache = NULL; |
| 191 | kmem_cache_destroy(revoke_table_cache); |
| 192 | revoke_table_cache = NULL; |
| 193 | } |
| 194 | |
| 195 | /* Initialise the revoke table for a given journal to a given size. */ |
| 196 | |
| 197 | int journal_init_revoke(journal_t *journal, int hash_size) |
| 198 | { |
| 199 | int shift, tmp; |
| 200 | |
| 201 | J_ASSERT (journal->j_revoke_table[0] == NULL); |
| 202 | |
| 203 | shift = 0; |
| 204 | tmp = hash_size; |
| 205 | while((tmp >>= 1UL) != 0UL) |
| 206 | shift++; |
| 207 | |
| 208 | journal->j_revoke_table[0] = kmem_cache_alloc(revoke_table_cache, GFP_KERNEL); |
| 209 | if (!journal->j_revoke_table[0]) |
| 210 | return -ENOMEM; |
| 211 | journal->j_revoke = journal->j_revoke_table[0]; |
| 212 | |
| 213 | /* Check that the hash_size is a power of two */ |
| 214 | J_ASSERT ((hash_size & (hash_size-1)) == 0); |
| 215 | |
| 216 | journal->j_revoke->hash_size = hash_size; |
| 217 | |
| 218 | journal->j_revoke->hash_shift = shift; |
| 219 | |
| 220 | journal->j_revoke->hash_table = |
| 221 | kmalloc(hash_size * sizeof(struct list_head), GFP_KERNEL); |
| 222 | if (!journal->j_revoke->hash_table) { |
| 223 | kmem_cache_free(revoke_table_cache, journal->j_revoke_table[0]); |
| 224 | journal->j_revoke = NULL; |
| 225 | return -ENOMEM; |
| 226 | } |
| 227 | |
| 228 | for (tmp = 0; tmp < hash_size; tmp++) |
| 229 | INIT_LIST_HEAD(&journal->j_revoke->hash_table[tmp]); |
| 230 | |
| 231 | journal->j_revoke_table[1] = kmem_cache_alloc(revoke_table_cache, GFP_KERNEL); |
| 232 | if (!journal->j_revoke_table[1]) { |
| 233 | kfree(journal->j_revoke_table[0]->hash_table); |
| 234 | kmem_cache_free(revoke_table_cache, journal->j_revoke_table[0]); |
| 235 | return -ENOMEM; |
| 236 | } |
| 237 | |
| 238 | journal->j_revoke = journal->j_revoke_table[1]; |
| 239 | |
| 240 | /* Check that the hash_size is a power of two */ |
| 241 | J_ASSERT ((hash_size & (hash_size-1)) == 0); |
| 242 | |
| 243 | journal->j_revoke->hash_size = hash_size; |
| 244 | |
| 245 | journal->j_revoke->hash_shift = shift; |
| 246 | |
| 247 | journal->j_revoke->hash_table = |
| 248 | kmalloc(hash_size * sizeof(struct list_head), GFP_KERNEL); |
| 249 | if (!journal->j_revoke->hash_table) { |
| 250 | kfree(journal->j_revoke_table[0]->hash_table); |
| 251 | kmem_cache_free(revoke_table_cache, journal->j_revoke_table[0]); |
| 252 | kmem_cache_free(revoke_table_cache, journal->j_revoke_table[1]); |
| 253 | journal->j_revoke = NULL; |
| 254 | return -ENOMEM; |
| 255 | } |
| 256 | |
| 257 | for (tmp = 0; tmp < hash_size; tmp++) |
| 258 | INIT_LIST_HEAD(&journal->j_revoke->hash_table[tmp]); |
| 259 | |
| 260 | spin_lock_init(&journal->j_revoke_lock); |
| 261 | |
| 262 | return 0; |
| 263 | } |
| 264 | |
| 265 | /* Destoy a journal's revoke table. The table must already be empty! */ |
| 266 | |
| 267 | void journal_destroy_revoke(journal_t *journal) |
| 268 | { |
| 269 | struct jbd_revoke_table_s *table; |
| 270 | struct list_head *hash_list; |
| 271 | int i; |
| 272 | |
| 273 | table = journal->j_revoke_table[0]; |
| 274 | if (!table) |
| 275 | return; |
| 276 | |
| 277 | for (i=0; i<table->hash_size; i++) { |
| 278 | hash_list = &table->hash_table[i]; |
| 279 | J_ASSERT (list_empty(hash_list)); |
| 280 | } |
| 281 | |
| 282 | kfree(table->hash_table); |
| 283 | kmem_cache_free(revoke_table_cache, table); |
| 284 | journal->j_revoke = NULL; |
| 285 | |
| 286 | table = journal->j_revoke_table[1]; |
| 287 | if (!table) |
| 288 | return; |
| 289 | |
| 290 | for (i=0; i<table->hash_size; i++) { |
| 291 | hash_list = &table->hash_table[i]; |
| 292 | J_ASSERT (list_empty(hash_list)); |
| 293 | } |
| 294 | |
| 295 | kfree(table->hash_table); |
| 296 | kmem_cache_free(revoke_table_cache, table); |
| 297 | journal->j_revoke = NULL; |
| 298 | } |
| 299 | |
| 300 | |
| 301 | #ifdef __KERNEL__ |
| 302 | |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 303 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 304 | * journal_revoke: revoke a given buffer_head from the journal. This |
| 305 | * prevents the block from being replayed during recovery if we take a |
| 306 | * crash after this current transaction commits. Any subsequent |
| 307 | * metadata writes of the buffer in this transaction cancel the |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 308 | * revoke. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 309 | * |
| 310 | * Note that this call may block --- it is up to the caller to make |
| 311 | * sure that there are no further calls to journal_write_metadata |
| 312 | * before the revoke is complete. In ext3, this implies calling the |
| 313 | * revoke before clearing the block bitmap when we are deleting |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 314 | * metadata. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 315 | * |
| 316 | * Revoke performs a journal_forget on any buffer_head passed in as a |
| 317 | * parameter, but does _not_ forget the buffer_head if the bh was only |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 318 | * found implicitly. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 319 | * |
| 320 | * bh_in may not be a journalled buffer - it may have come off |
| 321 | * the hash tables without an attached journal_head. |
| 322 | * |
| 323 | * If bh_in is non-zero, journal_revoke() will decrement its b_count |
| 324 | * by one. |
| 325 | */ |
| 326 | |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 327 | int journal_revoke(handle_t *handle, unsigned long blocknr, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 328 | struct buffer_head *bh_in) |
| 329 | { |
| 330 | struct buffer_head *bh = NULL; |
| 331 | journal_t *journal; |
| 332 | struct block_device *bdev; |
| 333 | int err; |
| 334 | |
| 335 | might_sleep(); |
| 336 | if (bh_in) |
| 337 | BUFFER_TRACE(bh_in, "enter"); |
| 338 | |
| 339 | journal = handle->h_transaction->t_journal; |
| 340 | if (!journal_set_features(journal, 0, 0, JFS_FEATURE_INCOMPAT_REVOKE)){ |
| 341 | J_ASSERT (!"Cannot set revoke feature!"); |
| 342 | return -EINVAL; |
| 343 | } |
| 344 | |
| 345 | bdev = journal->j_fs_dev; |
| 346 | bh = bh_in; |
| 347 | |
| 348 | if (!bh) { |
| 349 | bh = __find_get_block(bdev, blocknr, journal->j_blocksize); |
| 350 | if (bh) |
| 351 | BUFFER_TRACE(bh, "found on hash"); |
| 352 | } |
| 353 | #ifdef JBD_EXPENSIVE_CHECKING |
| 354 | else { |
| 355 | struct buffer_head *bh2; |
| 356 | |
| 357 | /* If there is a different buffer_head lying around in |
| 358 | * memory anywhere... */ |
| 359 | bh2 = __find_get_block(bdev, blocknr, journal->j_blocksize); |
| 360 | if (bh2) { |
| 361 | /* ... and it has RevokeValid status... */ |
| 362 | if (bh2 != bh && buffer_revokevalid(bh2)) |
| 363 | /* ...then it better be revoked too, |
| 364 | * since it's illegal to create a revoke |
| 365 | * record against a buffer_head which is |
| 366 | * not marked revoked --- that would |
| 367 | * risk missing a subsequent revoke |
| 368 | * cancel. */ |
| 369 | J_ASSERT_BH(bh2, buffer_revoked(bh2)); |
| 370 | put_bh(bh2); |
| 371 | } |
| 372 | } |
| 373 | #endif |
| 374 | |
| 375 | /* We really ought not ever to revoke twice in a row without |
| 376 | first having the revoke cancelled: it's illegal to free a |
| 377 | block twice without allocating it in between! */ |
| 378 | if (bh) { |
| 379 | if (!J_EXPECT_BH(bh, !buffer_revoked(bh), |
| 380 | "inconsistent data on disk")) { |
| 381 | if (!bh_in) |
| 382 | brelse(bh); |
| 383 | return -EIO; |
| 384 | } |
| 385 | set_buffer_revoked(bh); |
| 386 | set_buffer_revokevalid(bh); |
| 387 | if (bh_in) { |
| 388 | BUFFER_TRACE(bh_in, "call journal_forget"); |
| 389 | journal_forget(handle, bh_in); |
| 390 | } else { |
| 391 | BUFFER_TRACE(bh, "call brelse"); |
| 392 | __brelse(bh); |
| 393 | } |
| 394 | } |
| 395 | |
| 396 | jbd_debug(2, "insert revoke for block %lu, bh_in=%p\n", blocknr, bh_in); |
| 397 | err = insert_revoke_hash(journal, blocknr, |
| 398 | handle->h_transaction->t_tid); |
| 399 | BUFFER_TRACE(bh_in, "exit"); |
| 400 | return err; |
| 401 | } |
| 402 | |
| 403 | /* |
| 404 | * Cancel an outstanding revoke. For use only internally by the |
| 405 | * journaling code (called from journal_get_write_access). |
| 406 | * |
| 407 | * We trust buffer_revoked() on the buffer if the buffer is already |
| 408 | * being journaled: if there is no revoke pending on the buffer, then we |
| 409 | * don't do anything here. |
| 410 | * |
| 411 | * This would break if it were possible for a buffer to be revoked and |
| 412 | * discarded, and then reallocated within the same transaction. In such |
| 413 | * a case we would have lost the revoked bit, but when we arrived here |
| 414 | * the second time we would still have a pending revoke to cancel. So, |
| 415 | * do not trust the Revoked bit on buffers unless RevokeValid is also |
| 416 | * set. |
| 417 | * |
| 418 | * The caller must have the journal locked. |
| 419 | */ |
| 420 | int journal_cancel_revoke(handle_t *handle, struct journal_head *jh) |
| 421 | { |
| 422 | struct jbd_revoke_record_s *record; |
| 423 | journal_t *journal = handle->h_transaction->t_journal; |
| 424 | int need_cancel; |
| 425 | int did_revoke = 0; /* akpm: debug */ |
| 426 | struct buffer_head *bh = jh2bh(jh); |
| 427 | |
| 428 | jbd_debug(4, "journal_head %p, cancelling revoke\n", jh); |
| 429 | |
| 430 | /* Is the existing Revoke bit valid? If so, we trust it, and |
| 431 | * only perform the full cancel if the revoke bit is set. If |
| 432 | * not, we can't trust the revoke bit, and we need to do the |
| 433 | * full search for a revoke record. */ |
| 434 | if (test_set_buffer_revokevalid(bh)) { |
| 435 | need_cancel = test_clear_buffer_revoked(bh); |
| 436 | } else { |
| 437 | need_cancel = 1; |
| 438 | clear_buffer_revoked(bh); |
| 439 | } |
| 440 | |
| 441 | if (need_cancel) { |
| 442 | record = find_revoke_record(journal, bh->b_blocknr); |
| 443 | if (record) { |
| 444 | jbd_debug(4, "cancelled existing revoke on " |
| 445 | "blocknr %llu\n", (unsigned long long)bh->b_blocknr); |
| 446 | spin_lock(&journal->j_revoke_lock); |
| 447 | list_del(&record->hash); |
| 448 | spin_unlock(&journal->j_revoke_lock); |
| 449 | kmem_cache_free(revoke_record_cache, record); |
| 450 | did_revoke = 1; |
| 451 | } |
| 452 | } |
| 453 | |
| 454 | #ifdef JBD_EXPENSIVE_CHECKING |
| 455 | /* There better not be one left behind by now! */ |
| 456 | record = find_revoke_record(journal, bh->b_blocknr); |
| 457 | J_ASSERT_JH(jh, record == NULL); |
| 458 | #endif |
| 459 | |
| 460 | /* Finally, have we just cleared revoke on an unhashed |
| 461 | * buffer_head? If so, we'd better make sure we clear the |
| 462 | * revoked status on any hashed alias too, otherwise the revoke |
| 463 | * state machine will get very upset later on. */ |
| 464 | if (need_cancel) { |
| 465 | struct buffer_head *bh2; |
| 466 | bh2 = __find_get_block(bh->b_bdev, bh->b_blocknr, bh->b_size); |
| 467 | if (bh2) { |
| 468 | if (bh2 != bh) |
| 469 | clear_buffer_revoked(bh2); |
| 470 | __brelse(bh2); |
| 471 | } |
| 472 | } |
| 473 | return did_revoke; |
| 474 | } |
| 475 | |
| 476 | /* journal_switch_revoke table select j_revoke for next transaction |
| 477 | * we do not want to suspend any processing until all revokes are |
| 478 | * written -bzzz |
| 479 | */ |
| 480 | void journal_switch_revoke_table(journal_t *journal) |
| 481 | { |
| 482 | int i; |
| 483 | |
| 484 | if (journal->j_revoke == journal->j_revoke_table[0]) |
| 485 | journal->j_revoke = journal->j_revoke_table[1]; |
| 486 | else |
| 487 | journal->j_revoke = journal->j_revoke_table[0]; |
| 488 | |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 489 | for (i = 0; i < journal->j_revoke->hash_size; i++) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 490 | INIT_LIST_HEAD(&journal->j_revoke->hash_table[i]); |
| 491 | } |
| 492 | |
| 493 | /* |
| 494 | * Write revoke records to the journal for all entries in the current |
| 495 | * revoke hash, deleting the entries as we go. |
| 496 | * |
| 497 | * Called with the journal lock held. |
| 498 | */ |
| 499 | |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 500 | void journal_write_revoke_records(journal_t *journal, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 501 | transaction_t *transaction) |
| 502 | { |
| 503 | struct journal_head *descriptor; |
| 504 | struct jbd_revoke_record_s *record; |
| 505 | struct jbd_revoke_table_s *revoke; |
| 506 | struct list_head *hash_list; |
| 507 | int i, offset, count; |
| 508 | |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 509 | descriptor = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 510 | offset = 0; |
| 511 | count = 0; |
| 512 | |
| 513 | /* select revoke table for committing transaction */ |
| 514 | revoke = journal->j_revoke == journal->j_revoke_table[0] ? |
| 515 | journal->j_revoke_table[1] : journal->j_revoke_table[0]; |
| 516 | |
| 517 | for (i = 0; i < revoke->hash_size; i++) { |
| 518 | hash_list = &revoke->hash_table[i]; |
| 519 | |
| 520 | while (!list_empty(hash_list)) { |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 521 | record = (struct jbd_revoke_record_s *) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 522 | hash_list->next; |
| 523 | write_one_revoke_record(journal, transaction, |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 524 | &descriptor, &offset, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 525 | record); |
| 526 | count++; |
| 527 | list_del(&record->hash); |
| 528 | kmem_cache_free(revoke_record_cache, record); |
| 529 | } |
| 530 | } |
| 531 | if (descriptor) |
| 532 | flush_descriptor(journal, descriptor, offset); |
| 533 | jbd_debug(1, "Wrote %d revoke records\n", count); |
| 534 | } |
| 535 | |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 536 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 537 | * Write out one revoke record. We need to create a new descriptor |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 538 | * block if the old one is full or if we have not already created one. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 539 | */ |
| 540 | |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 541 | static void write_one_revoke_record(journal_t *journal, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 542 | transaction_t *transaction, |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 543 | struct journal_head **descriptorp, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 544 | int *offsetp, |
| 545 | struct jbd_revoke_record_s *record) |
| 546 | { |
| 547 | struct journal_head *descriptor; |
| 548 | int offset; |
| 549 | journal_header_t *header; |
| 550 | |
| 551 | /* If we are already aborting, this all becomes a noop. We |
| 552 | still need to go round the loop in |
| 553 | journal_write_revoke_records in order to free all of the |
| 554 | revoke records: only the IO to the journal is omitted. */ |
| 555 | if (is_journal_aborted(journal)) |
| 556 | return; |
| 557 | |
| 558 | descriptor = *descriptorp; |
| 559 | offset = *offsetp; |
| 560 | |
| 561 | /* Make sure we have a descriptor with space left for the record */ |
| 562 | if (descriptor) { |
| 563 | if (offset == journal->j_blocksize) { |
| 564 | flush_descriptor(journal, descriptor, offset); |
| 565 | descriptor = NULL; |
| 566 | } |
| 567 | } |
| 568 | |
| 569 | if (!descriptor) { |
| 570 | descriptor = journal_get_descriptor_buffer(journal); |
| 571 | if (!descriptor) |
| 572 | return; |
| 573 | header = (journal_header_t *) &jh2bh(descriptor)->b_data[0]; |
| 574 | header->h_magic = cpu_to_be32(JFS_MAGIC_NUMBER); |
| 575 | header->h_blocktype = cpu_to_be32(JFS_REVOKE_BLOCK); |
| 576 | header->h_sequence = cpu_to_be32(transaction->t_tid); |
| 577 | |
| 578 | /* Record it so that we can wait for IO completion later */ |
| 579 | JBUFFER_TRACE(descriptor, "file as BJ_LogCtl"); |
| 580 | journal_file_buffer(descriptor, transaction, BJ_LogCtl); |
| 581 | |
| 582 | offset = sizeof(journal_revoke_header_t); |
| 583 | *descriptorp = descriptor; |
| 584 | } |
| 585 | |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 586 | * ((__be32 *)(&jh2bh(descriptor)->b_data[offset])) = |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 587 | cpu_to_be32(record->blocknr); |
| 588 | offset += 4; |
| 589 | *offsetp = offset; |
| 590 | } |
| 591 | |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 592 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 593 | * Flush a revoke descriptor out to the journal. If we are aborting, |
| 594 | * this is a noop; otherwise we are generating a buffer which needs to |
| 595 | * be waited for during commit, so it has to go onto the appropriate |
| 596 | * journal buffer list. |
| 597 | */ |
| 598 | |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 599 | static void flush_descriptor(journal_t *journal, |
| 600 | struct journal_head *descriptor, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 601 | int offset) |
| 602 | { |
| 603 | journal_revoke_header_t *header; |
| 604 | struct buffer_head *bh = jh2bh(descriptor); |
| 605 | |
| 606 | if (is_journal_aborted(journal)) { |
| 607 | put_bh(bh); |
| 608 | return; |
| 609 | } |
| 610 | |
| 611 | header = (journal_revoke_header_t *) jh2bh(descriptor)->b_data; |
| 612 | header->r_count = cpu_to_be32(offset); |
| 613 | set_buffer_jwrite(bh); |
| 614 | BUFFER_TRACE(bh, "write"); |
| 615 | set_buffer_dirty(bh); |
Jan Kara | 2670769 | 2005-09-06 15:19:12 -0700 | [diff] [blame] | 616 | ll_rw_block(SWRITE, 1, &bh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 617 | } |
| 618 | #endif |
| 619 | |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 620 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 621 | * Revoke support for recovery. |
| 622 | * |
| 623 | * Recovery needs to be able to: |
| 624 | * |
| 625 | * record all revoke records, including the tid of the latest instance |
| 626 | * of each revoke in the journal |
| 627 | * |
| 628 | * check whether a given block in a given transaction should be replayed |
| 629 | * (ie. has not been revoked by a revoke record in that or a subsequent |
| 630 | * transaction) |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 631 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 632 | * empty the revoke table after recovery. |
| 633 | */ |
| 634 | |
| 635 | /* |
| 636 | * First, setting revoke records. We create a new revoke record for |
| 637 | * every block ever revoked in the log as we scan it for recovery, and |
| 638 | * we update the existing records if we find multiple revokes for a |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 639 | * single block. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 640 | */ |
| 641 | |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 642 | int journal_set_revoke(journal_t *journal, |
| 643 | unsigned long blocknr, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 644 | tid_t sequence) |
| 645 | { |
| 646 | struct jbd_revoke_record_s *record; |
| 647 | |
| 648 | record = find_revoke_record(journal, blocknr); |
| 649 | if (record) { |
| 650 | /* If we have multiple occurrences, only record the |
| 651 | * latest sequence number in the hashed record */ |
| 652 | if (tid_gt(sequence, record->sequence)) |
| 653 | record->sequence = sequence; |
| 654 | return 0; |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 655 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 656 | return insert_revoke_hash(journal, blocknr, sequence); |
| 657 | } |
| 658 | |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 659 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 660 | * Test revoke records. For a given block referenced in the log, has |
| 661 | * that block been revoked? A revoke record with a given transaction |
| 662 | * sequence number revokes all blocks in that transaction and earlier |
| 663 | * ones, but later transactions still need replayed. |
| 664 | */ |
| 665 | |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 666 | int journal_test_revoke(journal_t *journal, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 667 | unsigned long blocknr, |
| 668 | tid_t sequence) |
| 669 | { |
| 670 | struct jbd_revoke_record_s *record; |
| 671 | |
| 672 | record = find_revoke_record(journal, blocknr); |
| 673 | if (!record) |
| 674 | return 0; |
| 675 | if (tid_gt(sequence, record->sequence)) |
| 676 | return 0; |
| 677 | return 1; |
| 678 | } |
| 679 | |
| 680 | /* |
| 681 | * Finally, once recovery is over, we need to clear the revoke table so |
| 682 | * that it can be reused by the running filesystem. |
| 683 | */ |
| 684 | |
| 685 | void journal_clear_revoke(journal_t *journal) |
| 686 | { |
| 687 | int i; |
| 688 | struct list_head *hash_list; |
| 689 | struct jbd_revoke_record_s *record; |
| 690 | struct jbd_revoke_table_s *revoke; |
| 691 | |
| 692 | revoke = journal->j_revoke; |
| 693 | |
| 694 | for (i = 0; i < revoke->hash_size; i++) { |
| 695 | hash_list = &revoke->hash_table[i]; |
| 696 | while (!list_empty(hash_list)) { |
| 697 | record = (struct jbd_revoke_record_s*) hash_list->next; |
| 698 | list_del(&record->hash); |
| 699 | kmem_cache_free(revoke_record_cache, record); |
| 700 | } |
| 701 | } |
| 702 | } |