Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
Uwe Zeisberger | f30c226 | 2006-10-03 23:01:26 +0200 | [diff] [blame] | 2 | * linux/fs/jbd/journal.c |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3 | * |
| 4 | * Written by Stephen C. Tweedie <sct@redhat.com>, 1998 |
| 5 | * |
| 6 | * Copyright 1998 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 | * Generic filesystem journal-writing code; part of the ext2fs |
| 13 | * journaling system. |
| 14 | * |
| 15 | * This file manages journals: areas of disk reserved for logging |
| 16 | * transactional updates. This includes the kernel journaling thread |
| 17 | * which is responsible for scheduling updates to the log. |
| 18 | * |
| 19 | * We do not actually manage the physical storage of the journal in this |
| 20 | * file: that is left to a per-journal policy function, which allows us |
| 21 | * to store the journal within a filesystem-specified area for ext2 |
| 22 | * journaling (ext2 can use a reserved inode for storing the log). |
| 23 | */ |
| 24 | |
| 25 | #include <linux/module.h> |
| 26 | #include <linux/time.h> |
| 27 | #include <linux/fs.h> |
| 28 | #include <linux/jbd.h> |
| 29 | #include <linux/errno.h> |
| 30 | #include <linux/slab.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 31 | #include <linux/init.h> |
| 32 | #include <linux/mm.h> |
Nigel Cunningham | 7dfb710 | 2006-12-06 20:34:23 -0800 | [diff] [blame] | 33 | #include <linux/freezer.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | #include <linux/pagemap.h> |
Andrew Morton | 8d8c851 | 2006-03-25 03:06:53 -0800 | [diff] [blame] | 35 | #include <linux/kthread.h> |
Randy Dunlap | c9cf552 | 2006-06-27 02:53:52 -0700 | [diff] [blame] | 36 | #include <linux/poison.h> |
Andrew Morton | 8d8c851 | 2006-03-25 03:06:53 -0800 | [diff] [blame] | 37 | #include <linux/proc_fs.h> |
Jose R. Santos | c2a9159 | 2007-10-18 23:39:22 -0700 | [diff] [blame] | 38 | #include <linux/debugfs.h> |
Andrew Morton | 8d8c851 | 2006-03-25 03:06:53 -0800 | [diff] [blame] | 39 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | #include <asm/uaccess.h> |
| 41 | #include <asm/page.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | |
| 43 | EXPORT_SYMBOL(journal_start); |
| 44 | EXPORT_SYMBOL(journal_restart); |
| 45 | EXPORT_SYMBOL(journal_extend); |
| 46 | EXPORT_SYMBOL(journal_stop); |
| 47 | EXPORT_SYMBOL(journal_lock_updates); |
| 48 | EXPORT_SYMBOL(journal_unlock_updates); |
| 49 | EXPORT_SYMBOL(journal_get_write_access); |
| 50 | EXPORT_SYMBOL(journal_get_create_access); |
| 51 | EXPORT_SYMBOL(journal_get_undo_access); |
| 52 | EXPORT_SYMBOL(journal_dirty_data); |
| 53 | EXPORT_SYMBOL(journal_dirty_metadata); |
| 54 | EXPORT_SYMBOL(journal_release_buffer); |
| 55 | EXPORT_SYMBOL(journal_forget); |
| 56 | #if 0 |
| 57 | EXPORT_SYMBOL(journal_sync_buffer); |
| 58 | #endif |
| 59 | EXPORT_SYMBOL(journal_flush); |
| 60 | EXPORT_SYMBOL(journal_revoke); |
| 61 | |
| 62 | EXPORT_SYMBOL(journal_init_dev); |
| 63 | EXPORT_SYMBOL(journal_init_inode); |
| 64 | EXPORT_SYMBOL(journal_update_format); |
| 65 | EXPORT_SYMBOL(journal_check_used_features); |
| 66 | EXPORT_SYMBOL(journal_check_available_features); |
| 67 | EXPORT_SYMBOL(journal_set_features); |
| 68 | EXPORT_SYMBOL(journal_create); |
| 69 | EXPORT_SYMBOL(journal_load); |
| 70 | EXPORT_SYMBOL(journal_destroy); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | EXPORT_SYMBOL(journal_update_superblock); |
| 72 | EXPORT_SYMBOL(journal_abort); |
| 73 | EXPORT_SYMBOL(journal_errno); |
| 74 | EXPORT_SYMBOL(journal_ack_err); |
| 75 | EXPORT_SYMBOL(journal_clear_err); |
| 76 | EXPORT_SYMBOL(log_wait_commit); |
| 77 | EXPORT_SYMBOL(journal_start_commit); |
| 78 | EXPORT_SYMBOL(journal_force_commit_nested); |
| 79 | EXPORT_SYMBOL(journal_wipe); |
| 80 | EXPORT_SYMBOL(journal_blocks_per_page); |
| 81 | EXPORT_SYMBOL(journal_invalidatepage); |
| 82 | EXPORT_SYMBOL(journal_try_to_free_buffers); |
| 83 | EXPORT_SYMBOL(journal_force_commit); |
| 84 | |
| 85 | static int journal_convert_superblock_v1(journal_t *, journal_superblock_t *); |
Adrian Bunk | 022a4a7 | 2005-09-06 15:16:41 -0700 | [diff] [blame] | 86 | static void __journal_abort_soft (journal_t *journal, int errno); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 87 | |
| 88 | /* |
| 89 | * Helper function used to manage commit timeouts |
| 90 | */ |
| 91 | |
| 92 | static void commit_timeout(unsigned long __data) |
| 93 | { |
| 94 | struct task_struct * p = (struct task_struct *) __data; |
| 95 | |
| 96 | wake_up_process(p); |
| 97 | } |
| 98 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | /* |
| 100 | * kjournald: The main thread function used to manage a logging device |
| 101 | * journal. |
| 102 | * |
| 103 | * This kernel thread is responsible for two things: |
| 104 | * |
| 105 | * 1) COMMIT: Every so often we need to commit the current state of the |
| 106 | * filesystem to disk. The journal thread is responsible for writing |
| 107 | * all of the metadata buffers to disk. |
| 108 | * |
| 109 | * 2) CHECKPOINT: We cannot reuse a used section of the log file until all |
| 110 | * of the data in that part of the log has been rewritten elsewhere on |
| 111 | * the disk. Flushing these old buffers to reclaim space in the log is |
| 112 | * known as checkpointing, and this thread is responsible for that job. |
| 113 | */ |
| 114 | |
Adrian Bunk | 022a4a7 | 2005-09-06 15:16:41 -0700 | [diff] [blame] | 115 | static int kjournald(void *arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | { |
Andrew Morton | e3df189 | 2006-03-25 03:06:53 -0800 | [diff] [blame] | 117 | journal_t *journal = arg; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | transaction_t *transaction; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 119 | |
Andrew Morton | e3df189 | 2006-03-25 03:06:53 -0800 | [diff] [blame] | 120 | /* |
| 121 | * Set up an interval timer which can be used to trigger a commit wakeup |
| 122 | * after the commit interval expires |
| 123 | */ |
| 124 | setup_timer(&journal->j_commit_timer, commit_timeout, |
| 125 | (unsigned long)current); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 126 | |
| 127 | /* Record that the journal thread is running */ |
| 128 | journal->j_task = current; |
| 129 | wake_up(&journal->j_wait_done_commit); |
| 130 | |
| 131 | printk(KERN_INFO "kjournald starting. Commit interval %ld seconds\n", |
| 132 | journal->j_commit_interval / HZ); |
| 133 | |
| 134 | /* |
| 135 | * And now, wait forever for commit wakeup events. |
| 136 | */ |
| 137 | spin_lock(&journal->j_state_lock); |
| 138 | |
| 139 | loop: |
| 140 | if (journal->j_flags & JFS_UNMOUNT) |
| 141 | goto end_loop; |
| 142 | |
| 143 | jbd_debug(1, "commit_sequence=%d, commit_request=%d\n", |
| 144 | journal->j_commit_sequence, journal->j_commit_request); |
| 145 | |
| 146 | if (journal->j_commit_sequence != journal->j_commit_request) { |
| 147 | jbd_debug(1, "OK, requests differ\n"); |
| 148 | spin_unlock(&journal->j_state_lock); |
Andrew Morton | e3df189 | 2006-03-25 03:06:53 -0800 | [diff] [blame] | 149 | del_timer_sync(&journal->j_commit_timer); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | journal_commit_transaction(journal); |
| 151 | spin_lock(&journal->j_state_lock); |
| 152 | goto loop; |
| 153 | } |
| 154 | |
| 155 | wake_up(&journal->j_wait_done_commit); |
Christoph Lameter | 3e1d1d2 | 2005-06-24 23:13:50 -0700 | [diff] [blame] | 156 | if (freezing(current)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 157 | /* |
| 158 | * The simpler the better. Flushing journal isn't a |
| 159 | * good idea, because that depends on threads that may |
| 160 | * be already stopped. |
| 161 | */ |
| 162 | jbd_debug(1, "Now suspending kjournald\n"); |
| 163 | spin_unlock(&journal->j_state_lock); |
Christoph Lameter | 3e1d1d2 | 2005-06-24 23:13:50 -0700 | [diff] [blame] | 164 | refrigerator(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | spin_lock(&journal->j_state_lock); |
| 166 | } else { |
| 167 | /* |
| 168 | * We assume on resume that commits are already there, |
| 169 | * so we don't sleep |
| 170 | */ |
| 171 | DEFINE_WAIT(wait); |
| 172 | int should_sleep = 1; |
| 173 | |
| 174 | prepare_to_wait(&journal->j_wait_commit, &wait, |
| 175 | TASK_INTERRUPTIBLE); |
| 176 | if (journal->j_commit_sequence != journal->j_commit_request) |
| 177 | should_sleep = 0; |
| 178 | transaction = journal->j_running_transaction; |
| 179 | if (transaction && time_after_eq(jiffies, |
| 180 | transaction->t_expires)) |
| 181 | should_sleep = 0; |
Mark Fasheh | cbf0d27 | 2005-09-06 15:19:08 -0700 | [diff] [blame] | 182 | if (journal->j_flags & JFS_UNMOUNT) |
Dave Kleikamp | e9ad562 | 2006-09-27 01:49:35 -0700 | [diff] [blame] | 183 | should_sleep = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | if (should_sleep) { |
| 185 | spin_unlock(&journal->j_state_lock); |
| 186 | schedule(); |
| 187 | spin_lock(&journal->j_state_lock); |
| 188 | } |
| 189 | finish_wait(&journal->j_wait_commit, &wait); |
| 190 | } |
| 191 | |
| 192 | jbd_debug(1, "kjournald wakes\n"); |
| 193 | |
| 194 | /* |
| 195 | * Were we woken up by a commit wakeup event? |
| 196 | */ |
| 197 | transaction = journal->j_running_transaction; |
| 198 | if (transaction && time_after_eq(jiffies, transaction->t_expires)) { |
| 199 | journal->j_commit_request = transaction->t_tid; |
| 200 | jbd_debug(1, "woke because of timeout\n"); |
| 201 | } |
| 202 | goto loop; |
| 203 | |
| 204 | end_loop: |
| 205 | spin_unlock(&journal->j_state_lock); |
Andrew Morton | e3df189 | 2006-03-25 03:06:53 -0800 | [diff] [blame] | 206 | del_timer_sync(&journal->j_commit_timer); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | journal->j_task = NULL; |
| 208 | wake_up(&journal->j_wait_done_commit); |
| 209 | jbd_debug(1, "Journal thread exiting.\n"); |
| 210 | return 0; |
| 211 | } |
| 212 | |
Pavel Emelianov | 97f0678 | 2007-05-08 00:30:42 -0700 | [diff] [blame] | 213 | static int journal_start_thread(journal_t *journal) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 214 | { |
Pavel Emelianov | 97f0678 | 2007-05-08 00:30:42 -0700 | [diff] [blame] | 215 | struct task_struct *t; |
| 216 | |
| 217 | t = kthread_run(kjournald, journal, "kjournald"); |
| 218 | if (IS_ERR(t)) |
| 219 | return PTR_ERR(t); |
| 220 | |
Stephen Hemminger | c80544d | 2007-10-18 03:07:05 -0700 | [diff] [blame] | 221 | wait_event(journal->j_wait_done_commit, journal->j_task != NULL); |
Pavel Emelianov | 97f0678 | 2007-05-08 00:30:42 -0700 | [diff] [blame] | 222 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | } |
| 224 | |
| 225 | static void journal_kill_thread(journal_t *journal) |
| 226 | { |
| 227 | spin_lock(&journal->j_state_lock); |
| 228 | journal->j_flags |= JFS_UNMOUNT; |
| 229 | |
| 230 | while (journal->j_task) { |
| 231 | wake_up(&journal->j_wait_commit); |
| 232 | spin_unlock(&journal->j_state_lock); |
Stephen Hemminger | c80544d | 2007-10-18 03:07:05 -0700 | [diff] [blame] | 233 | wait_event(journal->j_wait_done_commit, |
| 234 | journal->j_task == NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 235 | spin_lock(&journal->j_state_lock); |
| 236 | } |
| 237 | spin_unlock(&journal->j_state_lock); |
| 238 | } |
| 239 | |
| 240 | /* |
| 241 | * journal_write_metadata_buffer: write a metadata buffer to the journal. |
| 242 | * |
| 243 | * Writes a metadata buffer to a given disk block. The actual IO is not |
| 244 | * performed but a new buffer_head is constructed which labels the data |
| 245 | * to be written with the correct destination disk block. |
| 246 | * |
| 247 | * Any magic-number escaping which needs to be done will cause a |
| 248 | * copy-out here. If the buffer happens to start with the |
| 249 | * JFS_MAGIC_NUMBER, then we can't write it to the log directly: the |
| 250 | * magic number is only written to the log for descripter blocks. In |
| 251 | * this case, we copy the data and replace the first word with 0, and we |
| 252 | * return a result code which indicates that this buffer needs to be |
| 253 | * marked as an escaped buffer in the corresponding log descriptor |
| 254 | * block. The missing word can then be restored when the block is read |
| 255 | * during recovery. |
| 256 | * |
| 257 | * If the source buffer has already been modified by a new transaction |
| 258 | * since we took the last commit snapshot, we use the frozen copy of |
| 259 | * that data for IO. If we end up using the existing buffer_head's data |
| 260 | * for the write, then we *have* to lock the buffer to prevent anyone |
| 261 | * else from using and possibly modifying it while the IO is in |
| 262 | * progress. |
| 263 | * |
| 264 | * The function returns a pointer to the buffer_heads to be used for IO. |
| 265 | * |
| 266 | * We assume that the journal has already been locked in this function. |
| 267 | * |
| 268 | * Return value: |
| 269 | * <0: Error |
| 270 | * >=0: Finished OK |
| 271 | * |
| 272 | * On success: |
| 273 | * Bit 0 set == escape performed on the data |
| 274 | * Bit 1 set == buffer copy-out performed (kfree the data after IO) |
| 275 | */ |
| 276 | |
| 277 | int journal_write_metadata_buffer(transaction_t *transaction, |
| 278 | struct journal_head *jh_in, |
| 279 | struct journal_head **jh_out, |
Eric Sandeen | 37ed322 | 2006-09-27 01:49:31 -0700 | [diff] [blame] | 280 | unsigned long blocknr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 281 | { |
| 282 | int need_copy_out = 0; |
| 283 | int done_copy_out = 0; |
| 284 | int do_escape = 0; |
| 285 | char *mapped_data; |
| 286 | struct buffer_head *new_bh; |
| 287 | struct journal_head *new_jh; |
| 288 | struct page *new_page; |
| 289 | unsigned int new_offset; |
| 290 | struct buffer_head *bh_in = jh2bh(jh_in); |
| 291 | |
| 292 | /* |
| 293 | * The buffer really shouldn't be locked: only the current committing |
| 294 | * transaction is allowed to write it, so nobody else is allowed |
| 295 | * to do any IO. |
| 296 | * |
| 297 | * akpm: except if we're journalling data, and write() output is |
| 298 | * also part of a shared mapping, and another thread has |
| 299 | * decided to launch a writepage() against this buffer. |
| 300 | */ |
| 301 | J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in)); |
| 302 | |
| 303 | new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL); |
| 304 | |
| 305 | /* |
| 306 | * If a new transaction has already done a buffer copy-out, then |
| 307 | * we use that version of the data for the commit. |
| 308 | */ |
| 309 | jbd_lock_bh_state(bh_in); |
| 310 | repeat: |
| 311 | if (jh_in->b_frozen_data) { |
| 312 | done_copy_out = 1; |
| 313 | new_page = virt_to_page(jh_in->b_frozen_data); |
| 314 | new_offset = offset_in_page(jh_in->b_frozen_data); |
| 315 | } else { |
| 316 | new_page = jh2bh(jh_in)->b_page; |
| 317 | new_offset = offset_in_page(jh2bh(jh_in)->b_data); |
| 318 | } |
| 319 | |
| 320 | mapped_data = kmap_atomic(new_page, KM_USER0); |
| 321 | /* |
| 322 | * Check for escaping |
| 323 | */ |
| 324 | if (*((__be32 *)(mapped_data + new_offset)) == |
| 325 | cpu_to_be32(JFS_MAGIC_NUMBER)) { |
| 326 | need_copy_out = 1; |
| 327 | do_escape = 1; |
| 328 | } |
| 329 | kunmap_atomic(mapped_data, KM_USER0); |
| 330 | |
| 331 | /* |
| 332 | * Do we need to do a data copy? |
| 333 | */ |
| 334 | if (need_copy_out && !done_copy_out) { |
| 335 | char *tmp; |
| 336 | |
| 337 | jbd_unlock_bh_state(bh_in); |
Mingming Cao | c089d49 | 2007-10-16 18:38:25 -0400 | [diff] [blame] | 338 | tmp = jbd_alloc(bh_in->b_size, GFP_NOFS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 339 | jbd_lock_bh_state(bh_in); |
| 340 | if (jh_in->b_frozen_data) { |
Mingming Cao | c089d49 | 2007-10-16 18:38:25 -0400 | [diff] [blame] | 341 | jbd_free(tmp, bh_in->b_size); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 342 | goto repeat; |
| 343 | } |
| 344 | |
| 345 | jh_in->b_frozen_data = tmp; |
| 346 | mapped_data = kmap_atomic(new_page, KM_USER0); |
| 347 | memcpy(tmp, mapped_data + new_offset, jh2bh(jh_in)->b_size); |
| 348 | kunmap_atomic(mapped_data, KM_USER0); |
| 349 | |
| 350 | new_page = virt_to_page(tmp); |
| 351 | new_offset = offset_in_page(tmp); |
| 352 | done_copy_out = 1; |
| 353 | } |
| 354 | |
| 355 | /* |
| 356 | * Did we need to do an escaping? Now we've done all the |
| 357 | * copying, we can finally do so. |
| 358 | */ |
| 359 | if (do_escape) { |
| 360 | mapped_data = kmap_atomic(new_page, KM_USER0); |
| 361 | *((unsigned int *)(mapped_data + new_offset)) = 0; |
| 362 | kunmap_atomic(mapped_data, KM_USER0); |
| 363 | } |
| 364 | |
| 365 | /* keep subsequent assertions sane */ |
| 366 | new_bh->b_state = 0; |
| 367 | init_buffer(new_bh, NULL, NULL); |
| 368 | atomic_set(&new_bh->b_count, 1); |
| 369 | jbd_unlock_bh_state(bh_in); |
| 370 | |
| 371 | new_jh = journal_add_journal_head(new_bh); /* This sleeps */ |
| 372 | |
| 373 | set_bh_page(new_bh, new_page, new_offset); |
| 374 | new_jh->b_transaction = NULL; |
| 375 | new_bh->b_size = jh2bh(jh_in)->b_size; |
| 376 | new_bh->b_bdev = transaction->t_journal->j_dev; |
| 377 | new_bh->b_blocknr = blocknr; |
| 378 | set_buffer_mapped(new_bh); |
| 379 | set_buffer_dirty(new_bh); |
| 380 | |
| 381 | *jh_out = new_jh; |
| 382 | |
| 383 | /* |
| 384 | * The to-be-written buffer needs to get moved to the io queue, |
| 385 | * and the original buffer whose contents we are shadowing or |
| 386 | * copying is moved to the transaction's shadow queue. |
| 387 | */ |
| 388 | JBUFFER_TRACE(jh_in, "file as BJ_Shadow"); |
| 389 | journal_file_buffer(jh_in, transaction, BJ_Shadow); |
| 390 | JBUFFER_TRACE(new_jh, "file as BJ_IO"); |
| 391 | journal_file_buffer(new_jh, transaction, BJ_IO); |
| 392 | |
| 393 | return do_escape | (done_copy_out << 1); |
| 394 | } |
| 395 | |
| 396 | /* |
| 397 | * Allocation code for the journal file. Manage the space left in the |
| 398 | * journal, so that we can begin checkpointing when appropriate. |
| 399 | */ |
| 400 | |
| 401 | /* |
| 402 | * __log_space_left: Return the number of free blocks left in the journal. |
| 403 | * |
| 404 | * Called with the journal already locked. |
| 405 | * |
| 406 | * Called under j_state_lock |
| 407 | */ |
| 408 | |
| 409 | int __log_space_left(journal_t *journal) |
| 410 | { |
| 411 | int left = journal->j_free; |
| 412 | |
| 413 | assert_spin_locked(&journal->j_state_lock); |
| 414 | |
| 415 | /* |
| 416 | * Be pessimistic here about the number of those free blocks which |
| 417 | * might be required for log descriptor control blocks. |
| 418 | */ |
| 419 | |
| 420 | #define MIN_LOG_RESERVED_BLOCKS 32 /* Allow for rounding errors */ |
| 421 | |
| 422 | left -= MIN_LOG_RESERVED_BLOCKS; |
| 423 | |
| 424 | if (left <= 0) |
| 425 | return 0; |
| 426 | left -= (left >> 3); |
| 427 | return left; |
| 428 | } |
| 429 | |
| 430 | /* |
| 431 | * Called under j_state_lock. Returns true if a transaction was started. |
| 432 | */ |
| 433 | int __log_start_commit(journal_t *journal, tid_t target) |
| 434 | { |
| 435 | /* |
| 436 | * Are we already doing a recent enough commit? |
| 437 | */ |
| 438 | if (!tid_geq(journal->j_commit_request, target)) { |
| 439 | /* |
| 440 | * We want a new commit: OK, mark the request and wakup the |
| 441 | * commit thread. We do _not_ do the commit ourselves. |
| 442 | */ |
| 443 | |
| 444 | journal->j_commit_request = target; |
| 445 | jbd_debug(1, "JBD: requesting commit %d/%d\n", |
| 446 | journal->j_commit_request, |
| 447 | journal->j_commit_sequence); |
| 448 | wake_up(&journal->j_wait_commit); |
| 449 | return 1; |
| 450 | } |
| 451 | return 0; |
| 452 | } |
| 453 | |
| 454 | int log_start_commit(journal_t *journal, tid_t tid) |
| 455 | { |
| 456 | int ret; |
| 457 | |
| 458 | spin_lock(&journal->j_state_lock); |
| 459 | ret = __log_start_commit(journal, tid); |
| 460 | spin_unlock(&journal->j_state_lock); |
| 461 | return ret; |
| 462 | } |
| 463 | |
| 464 | /* |
| 465 | * Force and wait upon a commit if the calling process is not within |
| 466 | * transaction. This is used for forcing out undo-protected data which contains |
| 467 | * bitmaps, when the fs is running out of space. |
| 468 | * |
| 469 | * We can only force the running transaction if we don't have an active handle; |
| 470 | * otherwise, we will deadlock. |
| 471 | * |
| 472 | * Returns true if a transaction was started. |
| 473 | */ |
| 474 | int journal_force_commit_nested(journal_t *journal) |
| 475 | { |
| 476 | transaction_t *transaction = NULL; |
| 477 | tid_t tid; |
| 478 | |
| 479 | spin_lock(&journal->j_state_lock); |
| 480 | if (journal->j_running_transaction && !current->journal_info) { |
| 481 | transaction = journal->j_running_transaction; |
| 482 | __log_start_commit(journal, transaction->t_tid); |
| 483 | } else if (journal->j_committing_transaction) |
| 484 | transaction = journal->j_committing_transaction; |
| 485 | |
| 486 | if (!transaction) { |
| 487 | spin_unlock(&journal->j_state_lock); |
| 488 | return 0; /* Nothing to retry */ |
| 489 | } |
| 490 | |
| 491 | tid = transaction->t_tid; |
| 492 | spin_unlock(&journal->j_state_lock); |
| 493 | log_wait_commit(journal, tid); |
| 494 | return 1; |
| 495 | } |
| 496 | |
| 497 | /* |
| 498 | * Start a commit of the current running transaction (if any). Returns true |
| 499 | * if a transaction was started, and fills its tid in at *ptid |
| 500 | */ |
| 501 | int journal_start_commit(journal_t *journal, tid_t *ptid) |
| 502 | { |
| 503 | int ret = 0; |
| 504 | |
| 505 | spin_lock(&journal->j_state_lock); |
| 506 | if (journal->j_running_transaction) { |
| 507 | tid_t tid = journal->j_running_transaction->t_tid; |
| 508 | |
| 509 | ret = __log_start_commit(journal, tid); |
| 510 | if (ret && ptid) |
| 511 | *ptid = tid; |
| 512 | } else if (journal->j_committing_transaction && ptid) { |
| 513 | /* |
| 514 | * If ext3_write_super() recently started a commit, then we |
| 515 | * have to wait for completion of that transaction |
| 516 | */ |
| 517 | *ptid = journal->j_committing_transaction->t_tid; |
| 518 | ret = 1; |
| 519 | } |
| 520 | spin_unlock(&journal->j_state_lock); |
| 521 | return ret; |
| 522 | } |
| 523 | |
| 524 | /* |
| 525 | * Wait for a specified commit to complete. |
| 526 | * The caller may not hold the journal lock. |
| 527 | */ |
| 528 | int log_wait_commit(journal_t *journal, tid_t tid) |
| 529 | { |
| 530 | int err = 0; |
| 531 | |
| 532 | #ifdef CONFIG_JBD_DEBUG |
| 533 | spin_lock(&journal->j_state_lock); |
| 534 | if (!tid_geq(journal->j_commit_request, tid)) { |
| 535 | printk(KERN_EMERG |
| 536 | "%s: error: j_commit_request=%d, tid=%d\n", |
Harvey Harrison | 08fc99b | 2008-04-28 02:16:16 -0700 | [diff] [blame] | 537 | __func__, journal->j_commit_request, tid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 538 | } |
| 539 | spin_unlock(&journal->j_state_lock); |
| 540 | #endif |
| 541 | spin_lock(&journal->j_state_lock); |
| 542 | while (tid_gt(tid, journal->j_commit_sequence)) { |
| 543 | jbd_debug(1, "JBD: want %d, j_commit_sequence=%d\n", |
| 544 | tid, journal->j_commit_sequence); |
| 545 | wake_up(&journal->j_wait_commit); |
| 546 | spin_unlock(&journal->j_state_lock); |
| 547 | wait_event(journal->j_wait_done_commit, |
| 548 | !tid_gt(tid, journal->j_commit_sequence)); |
| 549 | spin_lock(&journal->j_state_lock); |
| 550 | } |
| 551 | spin_unlock(&journal->j_state_lock); |
| 552 | |
| 553 | if (unlikely(is_journal_aborted(journal))) { |
| 554 | printk(KERN_EMERG "journal commit I/O error\n"); |
| 555 | err = -EIO; |
| 556 | } |
| 557 | return err; |
| 558 | } |
| 559 | |
| 560 | /* |
| 561 | * Log buffer allocation routines: |
| 562 | */ |
| 563 | |
| 564 | int journal_next_log_block(journal_t *journal, unsigned long *retp) |
| 565 | { |
| 566 | unsigned long blocknr; |
| 567 | |
| 568 | spin_lock(&journal->j_state_lock); |
| 569 | J_ASSERT(journal->j_free > 1); |
| 570 | |
| 571 | blocknr = journal->j_head; |
| 572 | journal->j_head++; |
| 573 | journal->j_free--; |
| 574 | if (journal->j_head == journal->j_last) |
| 575 | journal->j_head = journal->j_first; |
| 576 | spin_unlock(&journal->j_state_lock); |
| 577 | return journal_bmap(journal, blocknr, retp); |
| 578 | } |
| 579 | |
| 580 | /* |
| 581 | * Conversion of logical to physical block numbers for the journal |
| 582 | * |
| 583 | * On external journals the journal blocks are identity-mapped, so |
| 584 | * this is a no-op. If needed, we can use j_blk_offset - everything is |
| 585 | * ready. |
| 586 | */ |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 587 | int journal_bmap(journal_t *journal, unsigned long blocknr, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 588 | unsigned long *retp) |
| 589 | { |
| 590 | int err = 0; |
| 591 | unsigned long ret; |
| 592 | |
| 593 | if (journal->j_inode) { |
| 594 | ret = bmap(journal->j_inode, blocknr); |
| 595 | if (ret) |
| 596 | *retp = ret; |
| 597 | else { |
| 598 | char b[BDEVNAME_SIZE]; |
| 599 | |
| 600 | printk(KERN_ALERT "%s: journal block not found " |
| 601 | "at offset %lu on %s\n", |
Harvey Harrison | 08fc99b | 2008-04-28 02:16:16 -0700 | [diff] [blame] | 602 | __func__, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 603 | blocknr, |
| 604 | bdevname(journal->j_dev, b)); |
| 605 | err = -EIO; |
| 606 | __journal_abort_soft(journal, err); |
| 607 | } |
| 608 | } else { |
| 609 | *retp = blocknr; /* +journal->j_blk_offset */ |
| 610 | } |
| 611 | return err; |
| 612 | } |
| 613 | |
| 614 | /* |
| 615 | * We play buffer_head aliasing tricks to write data/metadata blocks to |
| 616 | * the journal without copying their contents, but for journal |
| 617 | * descriptor blocks we do need to generate bona fide buffers. |
| 618 | * |
| 619 | * After the caller of journal_get_descriptor_buffer() has finished modifying |
| 620 | * the buffer's contents they really should run flush_dcache_page(bh->b_page). |
| 621 | * But we don't bother doing that, so there will be coherency problems with |
| 622 | * mmaps of blockdevs which hold live JBD-controlled filesystems. |
| 623 | */ |
| 624 | struct journal_head *journal_get_descriptor_buffer(journal_t *journal) |
| 625 | { |
| 626 | struct buffer_head *bh; |
| 627 | unsigned long blocknr; |
| 628 | int err; |
| 629 | |
| 630 | err = journal_next_log_block(journal, &blocknr); |
| 631 | |
| 632 | if (err) |
| 633 | return NULL; |
| 634 | |
| 635 | bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); |
| 636 | lock_buffer(bh); |
| 637 | memset(bh->b_data, 0, journal->j_blocksize); |
| 638 | set_buffer_uptodate(bh); |
| 639 | unlock_buffer(bh); |
| 640 | BUFFER_TRACE(bh, "return this buffer"); |
| 641 | return journal_add_journal_head(bh); |
| 642 | } |
| 643 | |
| 644 | /* |
| 645 | * Management for journal control blocks: functions to create and |
| 646 | * destroy journal_t structures, and to initialise and read existing |
| 647 | * journal blocks from disk. */ |
| 648 | |
| 649 | /* First: create and setup a journal_t object in memory. We initialise |
| 650 | * very few fields yet: that has to wait until we have created the |
| 651 | * journal structures from from scratch, or loaded them from disk. */ |
| 652 | |
| 653 | static journal_t * journal_init_common (void) |
| 654 | { |
| 655 | journal_t *journal; |
| 656 | int err; |
| 657 | |
Mingming Cao | 8c3478a | 2007-10-18 23:39:20 -0700 | [diff] [blame] | 658 | journal = kzalloc(sizeof(*journal), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 659 | if (!journal) |
| 660 | goto fail; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 661 | |
| 662 | init_waitqueue_head(&journal->j_wait_transaction_locked); |
| 663 | init_waitqueue_head(&journal->j_wait_logspace); |
| 664 | init_waitqueue_head(&journal->j_wait_done_commit); |
| 665 | init_waitqueue_head(&journal->j_wait_checkpoint); |
| 666 | init_waitqueue_head(&journal->j_wait_commit); |
| 667 | init_waitqueue_head(&journal->j_wait_updates); |
Arjan van de Ven | 2c68ee7 | 2006-03-23 03:00:35 -0800 | [diff] [blame] | 668 | mutex_init(&journal->j_barrier); |
| 669 | mutex_init(&journal->j_checkpoint_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 670 | spin_lock_init(&journal->j_revoke_lock); |
| 671 | spin_lock_init(&journal->j_list_lock); |
| 672 | spin_lock_init(&journal->j_state_lock); |
| 673 | |
| 674 | journal->j_commit_interval = (HZ * JBD_DEFAULT_MAX_COMMIT_AGE); |
| 675 | |
| 676 | /* The journal is marked for error until we succeed with recovery! */ |
| 677 | journal->j_flags = JFS_ABORT; |
| 678 | |
| 679 | /* Set up a default-sized revoke table for the new mount. */ |
| 680 | err = journal_init_revoke(journal, JOURNAL_REVOKE_DEFAULT_HASH); |
| 681 | if (err) { |
| 682 | kfree(journal); |
| 683 | goto fail; |
| 684 | } |
| 685 | return journal; |
| 686 | fail: |
| 687 | return NULL; |
| 688 | } |
| 689 | |
| 690 | /* journal_init_dev and journal_init_inode: |
| 691 | * |
| 692 | * Create a journal structure assigned some fixed set of disk blocks to |
| 693 | * the journal. We don't actually touch those disk blocks yet, but we |
| 694 | * need to set up all of the mapping information to tell the journaling |
| 695 | * system where the journal blocks are. |
| 696 | * |
| 697 | */ |
| 698 | |
| 699 | /** |
Randy Dunlap | 0cf01f6 | 2008-03-19 17:00:44 -0700 | [diff] [blame] | 700 | * journal_t * journal_init_dev() - creates and initialises a journal structure |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 701 | * @bdev: Block device on which to create the journal |
| 702 | * @fs_dev: Device which hold journalled filesystem for this journal. |
| 703 | * @start: Block nr Start of journal. |
Eric Sandeen | 37ed322 | 2006-09-27 01:49:31 -0700 | [diff] [blame] | 704 | * @len: Length of the journal in blocks. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 705 | * @blocksize: blocksize of journalling device |
Randy Dunlap | 0cf01f6 | 2008-03-19 17:00:44 -0700 | [diff] [blame] | 706 | * |
| 707 | * Returns: a newly created journal_t * |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 708 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 709 | * journal_init_dev creates a journal which maps a fixed contiguous |
| 710 | * range of blocks on an arbitrary block device. |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 711 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 712 | */ |
| 713 | journal_t * journal_init_dev(struct block_device *bdev, |
| 714 | struct block_device *fs_dev, |
| 715 | int start, int len, int blocksize) |
| 716 | { |
| 717 | journal_t *journal = journal_init_common(); |
| 718 | struct buffer_head *bh; |
| 719 | int n; |
| 720 | |
| 721 | if (!journal) |
| 722 | return NULL; |
| 723 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 724 | /* journal descriptor can store up to n blocks -bzzz */ |
Zoltan Menyhart | d180779 | 2006-09-29 01:58:40 -0700 | [diff] [blame] | 725 | journal->j_blocksize = blocksize; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 726 | n = journal->j_blocksize / sizeof(journal_block_tag_t); |
| 727 | journal->j_wbufsize = n; |
| 728 | journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL); |
| 729 | if (!journal->j_wbuf) { |
| 730 | printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n", |
Harvey Harrison | 08fc99b | 2008-04-28 02:16:16 -0700 | [diff] [blame] | 731 | __func__); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 732 | kfree(journal); |
| 733 | journal = NULL; |
Eric Sesterhenn | 41716c7 | 2006-10-11 01:20:37 -0700 | [diff] [blame] | 734 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 735 | } |
Zoltan Menyhart | d180779 | 2006-09-29 01:58:40 -0700 | [diff] [blame] | 736 | journal->j_dev = bdev; |
| 737 | journal->j_fs_dev = fs_dev; |
| 738 | journal->j_blk_offset = start; |
| 739 | journal->j_maxlen = len; |
| 740 | |
| 741 | bh = __getblk(journal->j_dev, start, journal->j_blocksize); |
| 742 | J_ASSERT(bh != NULL); |
| 743 | journal->j_sb_buffer = bh; |
| 744 | journal->j_superblock = (journal_superblock_t *)bh->b_data; |
Eric Sesterhenn | 41716c7 | 2006-10-11 01:20:37 -0700 | [diff] [blame] | 745 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 746 | return journal; |
| 747 | } |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 748 | |
| 749 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 750 | * journal_t * journal_init_inode () - creates a journal which maps to a inode. |
| 751 | * @inode: An inode to create the journal in |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 752 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 753 | * journal_init_inode creates a journal which maps an on-disk inode as |
| 754 | * the journal. The inode must exist already, must support bmap() and |
| 755 | * must have all data blocks preallocated. |
| 756 | */ |
| 757 | journal_t * journal_init_inode (struct inode *inode) |
| 758 | { |
| 759 | struct buffer_head *bh; |
| 760 | journal_t *journal = journal_init_common(); |
| 761 | int err; |
| 762 | int n; |
| 763 | unsigned long blocknr; |
| 764 | |
| 765 | if (!journal) |
| 766 | return NULL; |
| 767 | |
| 768 | journal->j_dev = journal->j_fs_dev = inode->i_sb->s_bdev; |
| 769 | journal->j_inode = inode; |
| 770 | jbd_debug(1, |
| 771 | "journal %p: inode %s/%ld, size %Ld, bits %d, blksize %ld\n", |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 772 | journal, inode->i_sb->s_id, inode->i_ino, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 773 | (long long) inode->i_size, |
| 774 | inode->i_sb->s_blocksize_bits, inode->i_sb->s_blocksize); |
| 775 | |
| 776 | journal->j_maxlen = inode->i_size >> inode->i_sb->s_blocksize_bits; |
| 777 | journal->j_blocksize = inode->i_sb->s_blocksize; |
| 778 | |
| 779 | /* journal descriptor can store up to n blocks -bzzz */ |
| 780 | n = journal->j_blocksize / sizeof(journal_block_tag_t); |
| 781 | journal->j_wbufsize = n; |
| 782 | journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL); |
| 783 | if (!journal->j_wbuf) { |
| 784 | printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n", |
Harvey Harrison | 08fc99b | 2008-04-28 02:16:16 -0700 | [diff] [blame] | 785 | __func__); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 786 | kfree(journal); |
| 787 | return NULL; |
| 788 | } |
| 789 | |
| 790 | err = journal_bmap(journal, 0, &blocknr); |
| 791 | /* If that failed, give up */ |
| 792 | if (err) { |
| 793 | printk(KERN_ERR "%s: Cannnot locate journal superblock\n", |
Harvey Harrison | 08fc99b | 2008-04-28 02:16:16 -0700 | [diff] [blame] | 794 | __func__); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 795 | kfree(journal); |
| 796 | return NULL; |
| 797 | } |
| 798 | |
| 799 | bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); |
| 800 | J_ASSERT(bh != NULL); |
| 801 | journal->j_sb_buffer = bh; |
| 802 | journal->j_superblock = (journal_superblock_t *)bh->b_data; |
| 803 | |
| 804 | return journal; |
| 805 | } |
| 806 | |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 807 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 808 | * If the journal init or create aborts, we need to mark the journal |
| 809 | * superblock as being NULL to prevent the journal destroy from writing |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 810 | * back a bogus superblock. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 811 | */ |
| 812 | static void journal_fail_superblock (journal_t *journal) |
| 813 | { |
| 814 | struct buffer_head *bh = journal->j_sb_buffer; |
| 815 | brelse(bh); |
| 816 | journal->j_sb_buffer = NULL; |
| 817 | } |
| 818 | |
| 819 | /* |
| 820 | * Given a journal_t structure, initialise the various fields for |
| 821 | * startup of a new journaling session. We use this both when creating |
| 822 | * a journal, and after recovering an old journal to reset it for |
| 823 | * subsequent use. |
| 824 | */ |
| 825 | |
| 826 | static int journal_reset(journal_t *journal) |
| 827 | { |
| 828 | journal_superblock_t *sb = journal->j_superblock; |
Eric Sandeen | 37ed322 | 2006-09-27 01:49:31 -0700 | [diff] [blame] | 829 | unsigned long first, last; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 830 | |
| 831 | first = be32_to_cpu(sb->s_first); |
| 832 | last = be32_to_cpu(sb->s_maxlen); |
| 833 | |
| 834 | journal->j_first = first; |
| 835 | journal->j_last = last; |
| 836 | |
| 837 | journal->j_head = first; |
| 838 | journal->j_tail = first; |
| 839 | journal->j_free = last - first; |
| 840 | |
| 841 | journal->j_tail_sequence = journal->j_transaction_sequence; |
| 842 | journal->j_commit_sequence = journal->j_transaction_sequence - 1; |
| 843 | journal->j_commit_request = journal->j_commit_sequence; |
| 844 | |
| 845 | journal->j_max_transaction_buffers = journal->j_maxlen / 4; |
| 846 | |
| 847 | /* Add the dynamic fields and write it to disk. */ |
| 848 | journal_update_superblock(journal, 1); |
Pavel Emelianov | 97f0678 | 2007-05-08 00:30:42 -0700 | [diff] [blame] | 849 | return journal_start_thread(journal); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 850 | } |
| 851 | |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 852 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 853 | * int journal_create() - Initialise the new journal file |
| 854 | * @journal: Journal to create. This structure must have been initialised |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 855 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 856 | * Given a journal_t structure which tells us which disk blocks we can |
| 857 | * use, create a new journal superblock and initialise all of the |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 858 | * journal fields from scratch. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 859 | **/ |
| 860 | int journal_create(journal_t *journal) |
| 861 | { |
| 862 | unsigned long blocknr; |
| 863 | struct buffer_head *bh; |
| 864 | journal_superblock_t *sb; |
| 865 | int i, err; |
| 866 | |
| 867 | if (journal->j_maxlen < JFS_MIN_JOURNAL_BLOCKS) { |
| 868 | printk (KERN_ERR "Journal length (%d blocks) too short.\n", |
| 869 | journal->j_maxlen); |
| 870 | journal_fail_superblock(journal); |
| 871 | return -EINVAL; |
| 872 | } |
| 873 | |
| 874 | if (journal->j_inode == NULL) { |
| 875 | /* |
| 876 | * We don't know what block to start at! |
| 877 | */ |
| 878 | printk(KERN_EMERG |
| 879 | "%s: creation of journal on external device!\n", |
Harvey Harrison | 08fc99b | 2008-04-28 02:16:16 -0700 | [diff] [blame] | 880 | __func__); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 881 | BUG(); |
| 882 | } |
| 883 | |
| 884 | /* Zero out the entire journal on disk. We cannot afford to |
| 885 | have any blocks on disk beginning with JFS_MAGIC_NUMBER. */ |
| 886 | jbd_debug(1, "JBD: Zeroing out journal blocks...\n"); |
| 887 | for (i = 0; i < journal->j_maxlen; i++) { |
| 888 | err = journal_bmap(journal, i, &blocknr); |
| 889 | if (err) |
| 890 | return err; |
| 891 | bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); |
| 892 | lock_buffer(bh); |
| 893 | memset (bh->b_data, 0, journal->j_blocksize); |
| 894 | BUFFER_TRACE(bh, "marking dirty"); |
| 895 | mark_buffer_dirty(bh); |
| 896 | BUFFER_TRACE(bh, "marking uptodate"); |
| 897 | set_buffer_uptodate(bh); |
| 898 | unlock_buffer(bh); |
| 899 | __brelse(bh); |
| 900 | } |
| 901 | |
| 902 | sync_blockdev(journal->j_dev); |
| 903 | jbd_debug(1, "JBD: journal cleared.\n"); |
| 904 | |
| 905 | /* OK, fill in the initial static fields in the new superblock */ |
| 906 | sb = journal->j_superblock; |
| 907 | |
| 908 | sb->s_header.h_magic = cpu_to_be32(JFS_MAGIC_NUMBER); |
| 909 | sb->s_header.h_blocktype = cpu_to_be32(JFS_SUPERBLOCK_V2); |
| 910 | |
| 911 | sb->s_blocksize = cpu_to_be32(journal->j_blocksize); |
| 912 | sb->s_maxlen = cpu_to_be32(journal->j_maxlen); |
| 913 | sb->s_first = cpu_to_be32(1); |
| 914 | |
| 915 | journal->j_transaction_sequence = 1; |
| 916 | |
| 917 | journal->j_flags &= ~JFS_ABORT; |
| 918 | journal->j_format_version = 2; |
| 919 | |
| 920 | return journal_reset(journal); |
| 921 | } |
| 922 | |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 923 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 924 | * void journal_update_superblock() - Update journal sb on disk. |
| 925 | * @journal: The journal to update. |
| 926 | * @wait: Set to '0' if you don't want to wait for IO completion. |
| 927 | * |
| 928 | * Update a journal's dynamic superblock fields and write it to disk, |
| 929 | * optionally waiting for the IO to complete. |
| 930 | */ |
| 931 | void journal_update_superblock(journal_t *journal, int wait) |
| 932 | { |
| 933 | journal_superblock_t *sb = journal->j_superblock; |
| 934 | struct buffer_head *bh = journal->j_sb_buffer; |
| 935 | |
| 936 | /* |
| 937 | * As a special case, if the on-disk copy is already marked as needing |
| 938 | * no recovery (s_start == 0) and there are no outstanding transactions |
| 939 | * in the filesystem, then we can safely defer the superblock update |
| 940 | * until the next commit by setting JFS_FLUSHED. This avoids |
| 941 | * attempting a write to a potential-readonly device. |
| 942 | */ |
| 943 | if (sb->s_start == 0 && journal->j_tail_sequence == |
| 944 | journal->j_transaction_sequence) { |
| 945 | jbd_debug(1,"JBD: Skipping superblock update on recovered sb " |
| 946 | "(start %ld, seq %d, errno %d)\n", |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 947 | journal->j_tail, journal->j_tail_sequence, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 948 | journal->j_errno); |
| 949 | goto out; |
| 950 | } |
| 951 | |
| 952 | spin_lock(&journal->j_state_lock); |
| 953 | jbd_debug(1,"JBD: updating superblock (start %ld, seq %d, errno %d)\n", |
| 954 | journal->j_tail, journal->j_tail_sequence, journal->j_errno); |
| 955 | |
| 956 | sb->s_sequence = cpu_to_be32(journal->j_tail_sequence); |
| 957 | sb->s_start = cpu_to_be32(journal->j_tail); |
| 958 | sb->s_errno = cpu_to_be32(journal->j_errno); |
| 959 | spin_unlock(&journal->j_state_lock); |
| 960 | |
| 961 | BUFFER_TRACE(bh, "marking dirty"); |
| 962 | mark_buffer_dirty(bh); |
| 963 | if (wait) |
| 964 | sync_dirty_buffer(bh); |
| 965 | else |
Jan Kara | 2670769 | 2005-09-06 15:19:12 -0700 | [diff] [blame] | 966 | ll_rw_block(SWRITE, 1, &bh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 967 | |
| 968 | out: |
| 969 | /* If we have just flushed the log (by marking s_start==0), then |
| 970 | * any future commit will have to be careful to update the |
| 971 | * superblock again to re-record the true start of the log. */ |
| 972 | |
| 973 | spin_lock(&journal->j_state_lock); |
| 974 | if (sb->s_start) |
| 975 | journal->j_flags &= ~JFS_FLUSHED; |
| 976 | else |
| 977 | journal->j_flags |= JFS_FLUSHED; |
| 978 | spin_unlock(&journal->j_state_lock); |
| 979 | } |
| 980 | |
| 981 | /* |
| 982 | * Read the superblock for a given journal, performing initial |
| 983 | * validation of the format. |
| 984 | */ |
| 985 | |
| 986 | static int journal_get_superblock(journal_t *journal) |
| 987 | { |
| 988 | struct buffer_head *bh; |
| 989 | journal_superblock_t *sb; |
| 990 | int err = -EIO; |
| 991 | |
| 992 | bh = journal->j_sb_buffer; |
| 993 | |
| 994 | J_ASSERT(bh != NULL); |
| 995 | if (!buffer_uptodate(bh)) { |
| 996 | ll_rw_block(READ, 1, &bh); |
| 997 | wait_on_buffer(bh); |
| 998 | if (!buffer_uptodate(bh)) { |
| 999 | printk (KERN_ERR |
| 1000 | "JBD: IO error reading journal superblock\n"); |
| 1001 | goto out; |
| 1002 | } |
| 1003 | } |
| 1004 | |
| 1005 | sb = journal->j_superblock; |
| 1006 | |
| 1007 | err = -EINVAL; |
| 1008 | |
| 1009 | if (sb->s_header.h_magic != cpu_to_be32(JFS_MAGIC_NUMBER) || |
| 1010 | sb->s_blocksize != cpu_to_be32(journal->j_blocksize)) { |
| 1011 | printk(KERN_WARNING "JBD: no valid journal superblock found\n"); |
| 1012 | goto out; |
| 1013 | } |
| 1014 | |
| 1015 | switch(be32_to_cpu(sb->s_header.h_blocktype)) { |
| 1016 | case JFS_SUPERBLOCK_V1: |
| 1017 | journal->j_format_version = 1; |
| 1018 | break; |
| 1019 | case JFS_SUPERBLOCK_V2: |
| 1020 | journal->j_format_version = 2; |
| 1021 | break; |
| 1022 | default: |
| 1023 | printk(KERN_WARNING "JBD: unrecognised superblock format ID\n"); |
| 1024 | goto out; |
| 1025 | } |
| 1026 | |
| 1027 | if (be32_to_cpu(sb->s_maxlen) < journal->j_maxlen) |
| 1028 | journal->j_maxlen = be32_to_cpu(sb->s_maxlen); |
| 1029 | else if (be32_to_cpu(sb->s_maxlen) > journal->j_maxlen) { |
| 1030 | printk (KERN_WARNING "JBD: journal file too short\n"); |
| 1031 | goto out; |
| 1032 | } |
| 1033 | |
| 1034 | return 0; |
| 1035 | |
| 1036 | out: |
| 1037 | journal_fail_superblock(journal); |
| 1038 | return err; |
| 1039 | } |
| 1040 | |
| 1041 | /* |
| 1042 | * Load the on-disk journal superblock and read the key fields into the |
| 1043 | * journal_t. |
| 1044 | */ |
| 1045 | |
| 1046 | static int load_superblock(journal_t *journal) |
| 1047 | { |
| 1048 | int err; |
| 1049 | journal_superblock_t *sb; |
| 1050 | |
| 1051 | err = journal_get_superblock(journal); |
| 1052 | if (err) |
| 1053 | return err; |
| 1054 | |
| 1055 | sb = journal->j_superblock; |
| 1056 | |
| 1057 | journal->j_tail_sequence = be32_to_cpu(sb->s_sequence); |
| 1058 | journal->j_tail = be32_to_cpu(sb->s_start); |
| 1059 | journal->j_first = be32_to_cpu(sb->s_first); |
| 1060 | journal->j_last = be32_to_cpu(sb->s_maxlen); |
| 1061 | journal->j_errno = be32_to_cpu(sb->s_errno); |
| 1062 | |
| 1063 | return 0; |
| 1064 | } |
| 1065 | |
| 1066 | |
| 1067 | /** |
| 1068 | * int journal_load() - Read journal from disk. |
| 1069 | * @journal: Journal to act on. |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 1070 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1071 | * Given a journal_t structure which tells us which disk blocks contain |
| 1072 | * a journal, read the journal from disk to initialise the in-memory |
| 1073 | * structures. |
| 1074 | */ |
| 1075 | int journal_load(journal_t *journal) |
| 1076 | { |
| 1077 | int err; |
Badari Pulavarty | ea81739 | 2006-08-27 01:23:52 -0700 | [diff] [blame] | 1078 | journal_superblock_t *sb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1079 | |
| 1080 | err = load_superblock(journal); |
| 1081 | if (err) |
| 1082 | return err; |
| 1083 | |
Badari Pulavarty | ea81739 | 2006-08-27 01:23:52 -0700 | [diff] [blame] | 1084 | sb = journal->j_superblock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1085 | /* If this is a V2 superblock, then we have to check the |
| 1086 | * features flags on it. */ |
| 1087 | |
| 1088 | if (journal->j_format_version >= 2) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1089 | if ((sb->s_feature_ro_compat & |
| 1090 | ~cpu_to_be32(JFS_KNOWN_ROCOMPAT_FEATURES)) || |
| 1091 | (sb->s_feature_incompat & |
| 1092 | ~cpu_to_be32(JFS_KNOWN_INCOMPAT_FEATURES))) { |
| 1093 | printk (KERN_WARNING |
| 1094 | "JBD: Unrecognised features on journal\n"); |
| 1095 | return -EINVAL; |
| 1096 | } |
| 1097 | } |
| 1098 | |
| 1099 | /* Let the recovery code check whether it needs to recover any |
| 1100 | * data from the journal. */ |
| 1101 | if (journal_recover(journal)) |
| 1102 | goto recovery_error; |
| 1103 | |
| 1104 | /* OK, we've finished with the dynamic journal bits: |
| 1105 | * reinitialise the dynamic contents of the superblock in memory |
| 1106 | * and reset them on disk. */ |
| 1107 | if (journal_reset(journal)) |
| 1108 | goto recovery_error; |
| 1109 | |
| 1110 | journal->j_flags &= ~JFS_ABORT; |
| 1111 | journal->j_flags |= JFS_LOADED; |
| 1112 | return 0; |
| 1113 | |
| 1114 | recovery_error: |
| 1115 | printk (KERN_WARNING "JBD: recovery failed\n"); |
| 1116 | return -EIO; |
| 1117 | } |
| 1118 | |
| 1119 | /** |
| 1120 | * void journal_destroy() - Release a journal_t structure. |
| 1121 | * @journal: Journal to act on. |
| 1122 | * |
| 1123 | * Release a journal_t structure once it is no longer in use by the |
| 1124 | * journaled object. |
| 1125 | */ |
| 1126 | void journal_destroy(journal_t *journal) |
| 1127 | { |
| 1128 | /* Wait for the commit thread to wake up and die. */ |
| 1129 | journal_kill_thread(journal); |
| 1130 | |
| 1131 | /* Force a final log commit */ |
| 1132 | if (journal->j_running_transaction) |
| 1133 | journal_commit_transaction(journal); |
| 1134 | |
| 1135 | /* Force any old transactions to disk */ |
| 1136 | |
| 1137 | /* Totally anal locking here... */ |
| 1138 | spin_lock(&journal->j_list_lock); |
| 1139 | while (journal->j_checkpoint_transactions != NULL) { |
| 1140 | spin_unlock(&journal->j_list_lock); |
| 1141 | log_do_checkpoint(journal); |
| 1142 | spin_lock(&journal->j_list_lock); |
| 1143 | } |
| 1144 | |
| 1145 | J_ASSERT(journal->j_running_transaction == NULL); |
| 1146 | J_ASSERT(journal->j_committing_transaction == NULL); |
| 1147 | J_ASSERT(journal->j_checkpoint_transactions == NULL); |
| 1148 | spin_unlock(&journal->j_list_lock); |
| 1149 | |
| 1150 | /* We can now mark the journal as empty. */ |
| 1151 | journal->j_tail = 0; |
| 1152 | journal->j_tail_sequence = ++journal->j_transaction_sequence; |
| 1153 | if (journal->j_sb_buffer) { |
| 1154 | journal_update_superblock(journal, 1); |
| 1155 | brelse(journal->j_sb_buffer); |
| 1156 | } |
| 1157 | |
| 1158 | if (journal->j_inode) |
| 1159 | iput(journal->j_inode); |
| 1160 | if (journal->j_revoke) |
| 1161 | journal_destroy_revoke(journal); |
| 1162 | kfree(journal->j_wbuf); |
| 1163 | kfree(journal); |
| 1164 | } |
| 1165 | |
| 1166 | |
| 1167 | /** |
| 1168 | *int journal_check_used_features () - Check if features specified are used. |
| 1169 | * @journal: Journal to check. |
| 1170 | * @compat: bitmask of compatible features |
| 1171 | * @ro: bitmask of features that force read-only mount |
| 1172 | * @incompat: bitmask of incompatible features |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 1173 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1174 | * Check whether the journal uses all of a given set of |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 1175 | * features. Return true (non-zero) if it does. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1176 | **/ |
| 1177 | |
| 1178 | int journal_check_used_features (journal_t *journal, unsigned long compat, |
| 1179 | unsigned long ro, unsigned long incompat) |
| 1180 | { |
| 1181 | journal_superblock_t *sb; |
| 1182 | |
| 1183 | if (!compat && !ro && !incompat) |
| 1184 | return 1; |
| 1185 | if (journal->j_format_version == 1) |
| 1186 | return 0; |
| 1187 | |
| 1188 | sb = journal->j_superblock; |
| 1189 | |
| 1190 | if (((be32_to_cpu(sb->s_feature_compat) & compat) == compat) && |
| 1191 | ((be32_to_cpu(sb->s_feature_ro_compat) & ro) == ro) && |
| 1192 | ((be32_to_cpu(sb->s_feature_incompat) & incompat) == incompat)) |
| 1193 | return 1; |
| 1194 | |
| 1195 | return 0; |
| 1196 | } |
| 1197 | |
| 1198 | /** |
| 1199 | * int journal_check_available_features() - Check feature set in journalling layer |
| 1200 | * @journal: Journal to check. |
| 1201 | * @compat: bitmask of compatible features |
| 1202 | * @ro: bitmask of features that force read-only mount |
| 1203 | * @incompat: bitmask of incompatible features |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 1204 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1205 | * Check whether the journaling code supports the use of |
| 1206 | * all of a given set of features on this journal. Return true |
| 1207 | * (non-zero) if it can. */ |
| 1208 | |
| 1209 | int journal_check_available_features (journal_t *journal, unsigned long compat, |
| 1210 | unsigned long ro, unsigned long incompat) |
| 1211 | { |
| 1212 | journal_superblock_t *sb; |
| 1213 | |
| 1214 | if (!compat && !ro && !incompat) |
| 1215 | return 1; |
| 1216 | |
| 1217 | sb = journal->j_superblock; |
| 1218 | |
| 1219 | /* We can support any known requested features iff the |
| 1220 | * superblock is in version 2. Otherwise we fail to support any |
| 1221 | * extended sb features. */ |
| 1222 | |
| 1223 | if (journal->j_format_version != 2) |
| 1224 | return 0; |
| 1225 | |
| 1226 | if ((compat & JFS_KNOWN_COMPAT_FEATURES) == compat && |
| 1227 | (ro & JFS_KNOWN_ROCOMPAT_FEATURES) == ro && |
| 1228 | (incompat & JFS_KNOWN_INCOMPAT_FEATURES) == incompat) |
| 1229 | return 1; |
| 1230 | |
| 1231 | return 0; |
| 1232 | } |
| 1233 | |
| 1234 | /** |
| 1235 | * int journal_set_features () - Mark a given journal feature in the superblock |
| 1236 | * @journal: Journal to act on. |
| 1237 | * @compat: bitmask of compatible features |
| 1238 | * @ro: bitmask of features that force read-only mount |
| 1239 | * @incompat: bitmask of incompatible features |
| 1240 | * |
| 1241 | * Mark a given journal feature as present on the |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 1242 | * superblock. Returns true if the requested features could be set. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1243 | * |
| 1244 | */ |
| 1245 | |
| 1246 | int journal_set_features (journal_t *journal, unsigned long compat, |
| 1247 | unsigned long ro, unsigned long incompat) |
| 1248 | { |
| 1249 | journal_superblock_t *sb; |
| 1250 | |
| 1251 | if (journal_check_used_features(journal, compat, ro, incompat)) |
| 1252 | return 1; |
| 1253 | |
| 1254 | if (!journal_check_available_features(journal, compat, ro, incompat)) |
| 1255 | return 0; |
| 1256 | |
| 1257 | jbd_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n", |
| 1258 | compat, ro, incompat); |
| 1259 | |
| 1260 | sb = journal->j_superblock; |
| 1261 | |
| 1262 | sb->s_feature_compat |= cpu_to_be32(compat); |
| 1263 | sb->s_feature_ro_compat |= cpu_to_be32(ro); |
| 1264 | sb->s_feature_incompat |= cpu_to_be32(incompat); |
| 1265 | |
| 1266 | return 1; |
| 1267 | } |
| 1268 | |
| 1269 | |
| 1270 | /** |
| 1271 | * int journal_update_format () - Update on-disk journal structure. |
| 1272 | * @journal: Journal to act on. |
| 1273 | * |
| 1274 | * Given an initialised but unloaded journal struct, poke about in the |
| 1275 | * on-disk structure to update it to the most recent supported version. |
| 1276 | */ |
| 1277 | int journal_update_format (journal_t *journal) |
| 1278 | { |
| 1279 | journal_superblock_t *sb; |
| 1280 | int err; |
| 1281 | |
| 1282 | err = journal_get_superblock(journal); |
| 1283 | if (err) |
| 1284 | return err; |
| 1285 | |
| 1286 | sb = journal->j_superblock; |
| 1287 | |
| 1288 | switch (be32_to_cpu(sb->s_header.h_blocktype)) { |
| 1289 | case JFS_SUPERBLOCK_V2: |
| 1290 | return 0; |
| 1291 | case JFS_SUPERBLOCK_V1: |
| 1292 | return journal_convert_superblock_v1(journal, sb); |
| 1293 | default: |
| 1294 | break; |
| 1295 | } |
| 1296 | return -EINVAL; |
| 1297 | } |
| 1298 | |
| 1299 | static int journal_convert_superblock_v1(journal_t *journal, |
| 1300 | journal_superblock_t *sb) |
| 1301 | { |
| 1302 | int offset, blocksize; |
| 1303 | struct buffer_head *bh; |
| 1304 | |
| 1305 | printk(KERN_WARNING |
| 1306 | "JBD: Converting superblock from version 1 to 2.\n"); |
| 1307 | |
| 1308 | /* Pre-initialise new fields to zero */ |
| 1309 | offset = ((char *) &(sb->s_feature_compat)) - ((char *) sb); |
| 1310 | blocksize = be32_to_cpu(sb->s_blocksize); |
| 1311 | memset(&sb->s_feature_compat, 0, blocksize-offset); |
| 1312 | |
| 1313 | sb->s_nr_users = cpu_to_be32(1); |
| 1314 | sb->s_header.h_blocktype = cpu_to_be32(JFS_SUPERBLOCK_V2); |
| 1315 | journal->j_format_version = 2; |
| 1316 | |
| 1317 | bh = journal->j_sb_buffer; |
| 1318 | BUFFER_TRACE(bh, "marking dirty"); |
| 1319 | mark_buffer_dirty(bh); |
| 1320 | sync_dirty_buffer(bh); |
| 1321 | return 0; |
| 1322 | } |
| 1323 | |
| 1324 | |
| 1325 | /** |
| 1326 | * int journal_flush () - Flush journal |
| 1327 | * @journal: Journal to act on. |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 1328 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1329 | * Flush all data for a given journal to disk and empty the journal. |
| 1330 | * Filesystems can use this when remounting readonly to ensure that |
| 1331 | * recovery does not need to happen on remount. |
| 1332 | */ |
| 1333 | |
| 1334 | int journal_flush(journal_t *journal) |
| 1335 | { |
| 1336 | int err = 0; |
| 1337 | transaction_t *transaction = NULL; |
| 1338 | unsigned long old_tail; |
| 1339 | |
| 1340 | spin_lock(&journal->j_state_lock); |
| 1341 | |
| 1342 | /* Force everything buffered to the log... */ |
| 1343 | if (journal->j_running_transaction) { |
| 1344 | transaction = journal->j_running_transaction; |
| 1345 | __log_start_commit(journal, transaction->t_tid); |
| 1346 | } else if (journal->j_committing_transaction) |
| 1347 | transaction = journal->j_committing_transaction; |
| 1348 | |
| 1349 | /* Wait for the log commit to complete... */ |
| 1350 | if (transaction) { |
| 1351 | tid_t tid = transaction->t_tid; |
| 1352 | |
| 1353 | spin_unlock(&journal->j_state_lock); |
| 1354 | log_wait_commit(journal, tid); |
| 1355 | } else { |
| 1356 | spin_unlock(&journal->j_state_lock); |
| 1357 | } |
| 1358 | |
| 1359 | /* ...and flush everything in the log out to disk. */ |
| 1360 | spin_lock(&journal->j_list_lock); |
| 1361 | while (!err && journal->j_checkpoint_transactions != NULL) { |
| 1362 | spin_unlock(&journal->j_list_lock); |
| 1363 | err = log_do_checkpoint(journal); |
| 1364 | spin_lock(&journal->j_list_lock); |
| 1365 | } |
| 1366 | spin_unlock(&journal->j_list_lock); |
| 1367 | cleanup_journal_tail(journal); |
| 1368 | |
| 1369 | /* Finally, mark the journal as really needing no recovery. |
| 1370 | * This sets s_start==0 in the underlying superblock, which is |
| 1371 | * the magic code for a fully-recovered superblock. Any future |
| 1372 | * commits of data to the journal will restore the current |
| 1373 | * s_start value. */ |
| 1374 | spin_lock(&journal->j_state_lock); |
| 1375 | old_tail = journal->j_tail; |
| 1376 | journal->j_tail = 0; |
| 1377 | spin_unlock(&journal->j_state_lock); |
| 1378 | journal_update_superblock(journal, 1); |
| 1379 | spin_lock(&journal->j_state_lock); |
| 1380 | journal->j_tail = old_tail; |
| 1381 | |
| 1382 | J_ASSERT(!journal->j_running_transaction); |
| 1383 | J_ASSERT(!journal->j_committing_transaction); |
| 1384 | J_ASSERT(!journal->j_checkpoint_transactions); |
| 1385 | J_ASSERT(journal->j_head == journal->j_tail); |
| 1386 | J_ASSERT(journal->j_tail_sequence == journal->j_transaction_sequence); |
| 1387 | spin_unlock(&journal->j_state_lock); |
| 1388 | return err; |
| 1389 | } |
| 1390 | |
| 1391 | /** |
| 1392 | * int journal_wipe() - Wipe journal contents |
| 1393 | * @journal: Journal to act on. |
| 1394 | * @write: flag (see below) |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 1395 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1396 | * Wipe out all of the contents of a journal, safely. This will produce |
| 1397 | * a warning if the journal contains any valid recovery information. |
| 1398 | * Must be called between journal_init_*() and journal_load(). |
| 1399 | * |
| 1400 | * If 'write' is non-zero, then we wipe out the journal on disk; otherwise |
| 1401 | * we merely suppress recovery. |
| 1402 | */ |
| 1403 | |
| 1404 | int journal_wipe(journal_t *journal, int write) |
| 1405 | { |
| 1406 | journal_superblock_t *sb; |
| 1407 | int err = 0; |
| 1408 | |
| 1409 | J_ASSERT (!(journal->j_flags & JFS_LOADED)); |
| 1410 | |
| 1411 | err = load_superblock(journal); |
| 1412 | if (err) |
| 1413 | return err; |
| 1414 | |
| 1415 | sb = journal->j_superblock; |
| 1416 | |
| 1417 | if (!journal->j_tail) |
| 1418 | goto no_recovery; |
| 1419 | |
| 1420 | printk (KERN_WARNING "JBD: %s recovery information on journal\n", |
| 1421 | write ? "Clearing" : "Ignoring"); |
| 1422 | |
| 1423 | err = journal_skip_recovery(journal); |
| 1424 | if (write) |
| 1425 | journal_update_superblock(journal, 1); |
| 1426 | |
| 1427 | no_recovery: |
| 1428 | return err; |
| 1429 | } |
| 1430 | |
| 1431 | /* |
| 1432 | * journal_dev_name: format a character string to describe on what |
| 1433 | * device this journal is present. |
| 1434 | */ |
| 1435 | |
Adrian Bunk | 022a4a7 | 2005-09-06 15:16:41 -0700 | [diff] [blame] | 1436 | static const char *journal_dev_name(journal_t *journal, char *buffer) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1437 | { |
| 1438 | struct block_device *bdev; |
| 1439 | |
| 1440 | if (journal->j_inode) |
| 1441 | bdev = journal->j_inode->i_sb->s_bdev; |
| 1442 | else |
| 1443 | bdev = journal->j_dev; |
| 1444 | |
| 1445 | return bdevname(bdev, buffer); |
| 1446 | } |
| 1447 | |
| 1448 | /* |
| 1449 | * Journal abort has very specific semantics, which we describe |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 1450 | * for journal abort. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1451 | * |
| 1452 | * Two internal function, which provide abort to te jbd layer |
| 1453 | * itself are here. |
| 1454 | */ |
| 1455 | |
| 1456 | /* |
| 1457 | * Quick version for internal journal use (doesn't lock the journal). |
| 1458 | * Aborts hard --- we mark the abort as occurred, but do _nothing_ else, |
| 1459 | * and don't attempt to make any other journal updates. |
| 1460 | */ |
Adrian Bunk | 5330838 | 2008-02-06 01:40:12 -0800 | [diff] [blame] | 1461 | static void __journal_abort_hard(journal_t *journal) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1462 | { |
| 1463 | transaction_t *transaction; |
| 1464 | char b[BDEVNAME_SIZE]; |
| 1465 | |
| 1466 | if (journal->j_flags & JFS_ABORT) |
| 1467 | return; |
| 1468 | |
| 1469 | printk(KERN_ERR "Aborting journal on device %s.\n", |
| 1470 | journal_dev_name(journal, b)); |
| 1471 | |
| 1472 | spin_lock(&journal->j_state_lock); |
| 1473 | journal->j_flags |= JFS_ABORT; |
| 1474 | transaction = journal->j_running_transaction; |
| 1475 | if (transaction) |
| 1476 | __log_start_commit(journal, transaction->t_tid); |
| 1477 | spin_unlock(&journal->j_state_lock); |
| 1478 | } |
| 1479 | |
| 1480 | /* Soft abort: record the abort error status in the journal superblock, |
| 1481 | * but don't do any other IO. */ |
Adrian Bunk | 022a4a7 | 2005-09-06 15:16:41 -0700 | [diff] [blame] | 1482 | static void __journal_abort_soft (journal_t *journal, int errno) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1483 | { |
| 1484 | if (journal->j_flags & JFS_ABORT) |
| 1485 | return; |
| 1486 | |
| 1487 | if (!journal->j_errno) |
| 1488 | journal->j_errno = errno; |
| 1489 | |
| 1490 | __journal_abort_hard(journal); |
| 1491 | |
| 1492 | if (errno) |
| 1493 | journal_update_superblock(journal, 1); |
| 1494 | } |
| 1495 | |
| 1496 | /** |
| 1497 | * void journal_abort () - Shutdown the journal immediately. |
| 1498 | * @journal: the journal to shutdown. |
| 1499 | * @errno: an error number to record in the journal indicating |
| 1500 | * the reason for the shutdown. |
| 1501 | * |
| 1502 | * Perform a complete, immediate shutdown of the ENTIRE |
| 1503 | * journal (not of a single transaction). This operation cannot be |
| 1504 | * undone without closing and reopening the journal. |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 1505 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1506 | * The journal_abort function is intended to support higher level error |
| 1507 | * recovery mechanisms such as the ext2/ext3 remount-readonly error |
| 1508 | * mode. |
| 1509 | * |
| 1510 | * Journal abort has very specific semantics. Any existing dirty, |
| 1511 | * unjournaled buffers in the main filesystem will still be written to |
| 1512 | * disk by bdflush, but the journaling mechanism will be suspended |
| 1513 | * immediately and no further transaction commits will be honoured. |
| 1514 | * |
| 1515 | * Any dirty, journaled buffers will be written back to disk without |
| 1516 | * hitting the journal. Atomicity cannot be guaranteed on an aborted |
| 1517 | * filesystem, but we _do_ attempt to leave as much data as possible |
| 1518 | * behind for fsck to use for cleanup. |
| 1519 | * |
| 1520 | * Any attempt to get a new transaction handle on a journal which is in |
| 1521 | * ABORT state will just result in an -EROFS error return. A |
| 1522 | * journal_stop on an existing handle will return -EIO if we have |
| 1523 | * entered abort state during the update. |
| 1524 | * |
| 1525 | * Recursive transactions are not disturbed by journal abort until the |
| 1526 | * final journal_stop, which will receive the -EIO error. |
| 1527 | * |
| 1528 | * Finally, the journal_abort call allows the caller to supply an errno |
| 1529 | * which will be recorded (if possible) in the journal superblock. This |
| 1530 | * allows a client to record failure conditions in the middle of a |
| 1531 | * transaction without having to complete the transaction to record the |
| 1532 | * failure to disk. ext3_error, for example, now uses this |
| 1533 | * functionality. |
| 1534 | * |
| 1535 | * Errors which originate from within the journaling layer will NOT |
| 1536 | * supply an errno; a null errno implies that absolutely no further |
| 1537 | * writes are done to the journal (unless there are any already in |
| 1538 | * progress). |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 1539 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1540 | */ |
| 1541 | |
| 1542 | void journal_abort(journal_t *journal, int errno) |
| 1543 | { |
| 1544 | __journal_abort_soft(journal, errno); |
| 1545 | } |
| 1546 | |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 1547 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1548 | * int journal_errno () - returns the journal's error state. |
| 1549 | * @journal: journal to examine. |
| 1550 | * |
| 1551 | * This is the errno numbet set with journal_abort(), the last |
| 1552 | * time the journal was mounted - if the journal was stopped |
| 1553 | * without calling abort this will be 0. |
| 1554 | * |
| 1555 | * If the journal has been aborted on this mount time -EROFS will |
| 1556 | * be returned. |
| 1557 | */ |
| 1558 | int journal_errno(journal_t *journal) |
| 1559 | { |
| 1560 | int err; |
| 1561 | |
| 1562 | spin_lock(&journal->j_state_lock); |
| 1563 | if (journal->j_flags & JFS_ABORT) |
| 1564 | err = -EROFS; |
| 1565 | else |
| 1566 | err = journal->j_errno; |
| 1567 | spin_unlock(&journal->j_state_lock); |
| 1568 | return err; |
| 1569 | } |
| 1570 | |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 1571 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1572 | * int journal_clear_err () - clears the journal's error state |
| 1573 | * @journal: journal to act on. |
| 1574 | * |
| 1575 | * An error must be cleared or Acked to take a FS out of readonly |
| 1576 | * mode. |
| 1577 | */ |
| 1578 | int journal_clear_err(journal_t *journal) |
| 1579 | { |
| 1580 | int err = 0; |
| 1581 | |
| 1582 | spin_lock(&journal->j_state_lock); |
| 1583 | if (journal->j_flags & JFS_ABORT) |
| 1584 | err = -EROFS; |
| 1585 | else |
| 1586 | journal->j_errno = 0; |
| 1587 | spin_unlock(&journal->j_state_lock); |
| 1588 | return err; |
| 1589 | } |
| 1590 | |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 1591 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1592 | * void journal_ack_err() - Ack journal err. |
| 1593 | * @journal: journal to act on. |
| 1594 | * |
| 1595 | * An error must be cleared or Acked to take a FS out of readonly |
| 1596 | * mode. |
| 1597 | */ |
| 1598 | void journal_ack_err(journal_t *journal) |
| 1599 | { |
| 1600 | spin_lock(&journal->j_state_lock); |
| 1601 | if (journal->j_errno) |
| 1602 | journal->j_flags |= JFS_ACK_ERR; |
| 1603 | spin_unlock(&journal->j_state_lock); |
| 1604 | } |
| 1605 | |
| 1606 | int journal_blocks_per_page(struct inode *inode) |
| 1607 | { |
| 1608 | return 1 << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits); |
| 1609 | } |
| 1610 | |
| 1611 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1612 | * Journal_head storage management |
| 1613 | */ |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 1614 | static struct kmem_cache *journal_head_cache; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1615 | #ifdef CONFIG_JBD_DEBUG |
| 1616 | static atomic_t nr_journal_heads = ATOMIC_INIT(0); |
| 1617 | #endif |
| 1618 | |
| 1619 | static int journal_init_journal_head_cache(void) |
| 1620 | { |
| 1621 | int retval; |
| 1622 | |
Al Viro | 1076d17 | 2008-03-29 03:07:18 +0000 | [diff] [blame] | 1623 | J_ASSERT(journal_head_cache == NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1624 | journal_head_cache = kmem_cache_create("journal_head", |
| 1625 | sizeof(struct journal_head), |
| 1626 | 0, /* offset */ |
Mel Gorman | e12ba74 | 2007-10-16 01:25:52 -0700 | [diff] [blame] | 1627 | SLAB_TEMPORARY, /* flags */ |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 1628 | NULL); /* ctor */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1629 | retval = 0; |
Al Viro | 1076d17 | 2008-03-29 03:07:18 +0000 | [diff] [blame] | 1630 | if (!journal_head_cache) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1631 | retval = -ENOMEM; |
| 1632 | printk(KERN_EMERG "JBD: no memory for journal_head cache\n"); |
| 1633 | } |
| 1634 | return retval; |
| 1635 | } |
| 1636 | |
| 1637 | static void journal_destroy_journal_head_cache(void) |
| 1638 | { |
| 1639 | J_ASSERT(journal_head_cache != NULL); |
| 1640 | kmem_cache_destroy(journal_head_cache); |
| 1641 | journal_head_cache = NULL; |
| 1642 | } |
| 1643 | |
| 1644 | /* |
| 1645 | * journal_head splicing and dicing |
| 1646 | */ |
| 1647 | static struct journal_head *journal_alloc_journal_head(void) |
| 1648 | { |
| 1649 | struct journal_head *ret; |
| 1650 | static unsigned long last_warning; |
| 1651 | |
| 1652 | #ifdef CONFIG_JBD_DEBUG |
| 1653 | atomic_inc(&nr_journal_heads); |
| 1654 | #endif |
| 1655 | ret = kmem_cache_alloc(journal_head_cache, GFP_NOFS); |
Stephen Hemminger | c80544d | 2007-10-18 03:07:05 -0700 | [diff] [blame] | 1656 | if (ret == NULL) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1657 | jbd_debug(1, "out of memory for journal_head\n"); |
| 1658 | if (time_after(jiffies, last_warning + 5*HZ)) { |
| 1659 | printk(KERN_NOTICE "ENOMEM in %s, retrying.\n", |
Harvey Harrison | 08fc99b | 2008-04-28 02:16:16 -0700 | [diff] [blame] | 1660 | __func__); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1661 | last_warning = jiffies; |
| 1662 | } |
Stephen Hemminger | c80544d | 2007-10-18 03:07:05 -0700 | [diff] [blame] | 1663 | while (ret == NULL) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1664 | yield(); |
| 1665 | ret = kmem_cache_alloc(journal_head_cache, GFP_NOFS); |
| 1666 | } |
| 1667 | } |
| 1668 | return ret; |
| 1669 | } |
| 1670 | |
| 1671 | static void journal_free_journal_head(struct journal_head *jh) |
| 1672 | { |
| 1673 | #ifdef CONFIG_JBD_DEBUG |
| 1674 | atomic_dec(&nr_journal_heads); |
Randy Dunlap | c9cf552 | 2006-06-27 02:53:52 -0700 | [diff] [blame] | 1675 | memset(jh, JBD_POISON_FREE, sizeof(*jh)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1676 | #endif |
| 1677 | kmem_cache_free(journal_head_cache, jh); |
| 1678 | } |
| 1679 | |
| 1680 | /* |
| 1681 | * A journal_head is attached to a buffer_head whenever JBD has an |
| 1682 | * interest in the buffer. |
| 1683 | * |
| 1684 | * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit |
| 1685 | * is set. This bit is tested in core kernel code where we need to take |
| 1686 | * JBD-specific actions. Testing the zeroness of ->b_private is not reliable |
| 1687 | * there. |
| 1688 | * |
| 1689 | * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one. |
| 1690 | * |
| 1691 | * When a buffer has its BH_JBD bit set it is immune from being released by |
| 1692 | * core kernel code, mainly via ->b_count. |
| 1693 | * |
| 1694 | * A journal_head may be detached from its buffer_head when the journal_head's |
| 1695 | * b_transaction, b_cp_transaction and b_next_transaction pointers are NULL. |
| 1696 | * Various places in JBD call journal_remove_journal_head() to indicate that the |
| 1697 | * journal_head can be dropped if needed. |
| 1698 | * |
| 1699 | * Various places in the kernel want to attach a journal_head to a buffer_head |
| 1700 | * _before_ attaching the journal_head to a transaction. To protect the |
| 1701 | * journal_head in this situation, journal_add_journal_head elevates the |
| 1702 | * journal_head's b_jcount refcount by one. The caller must call |
| 1703 | * journal_put_journal_head() to undo this. |
| 1704 | * |
| 1705 | * So the typical usage would be: |
| 1706 | * |
| 1707 | * (Attach a journal_head if needed. Increments b_jcount) |
| 1708 | * struct journal_head *jh = journal_add_journal_head(bh); |
| 1709 | * ... |
| 1710 | * jh->b_transaction = xxx; |
| 1711 | * journal_put_journal_head(jh); |
| 1712 | * |
| 1713 | * Now, the journal_head's b_jcount is zero, but it is safe from being released |
| 1714 | * because it has a non-zero b_transaction. |
| 1715 | */ |
| 1716 | |
| 1717 | /* |
| 1718 | * Give a buffer_head a journal_head. |
| 1719 | * |
| 1720 | * Doesn't need the journal lock. |
| 1721 | * May sleep. |
| 1722 | */ |
| 1723 | struct journal_head *journal_add_journal_head(struct buffer_head *bh) |
| 1724 | { |
| 1725 | struct journal_head *jh; |
| 1726 | struct journal_head *new_jh = NULL; |
| 1727 | |
| 1728 | repeat: |
| 1729 | if (!buffer_jbd(bh)) { |
| 1730 | new_jh = journal_alloc_journal_head(); |
| 1731 | memset(new_jh, 0, sizeof(*new_jh)); |
| 1732 | } |
| 1733 | |
| 1734 | jbd_lock_bh_journal_head(bh); |
| 1735 | if (buffer_jbd(bh)) { |
| 1736 | jh = bh2jh(bh); |
| 1737 | } else { |
| 1738 | J_ASSERT_BH(bh, |
| 1739 | (atomic_read(&bh->b_count) > 0) || |
| 1740 | (bh->b_page && bh->b_page->mapping)); |
| 1741 | |
| 1742 | if (!new_jh) { |
| 1743 | jbd_unlock_bh_journal_head(bh); |
| 1744 | goto repeat; |
| 1745 | } |
| 1746 | |
| 1747 | jh = new_jh; |
| 1748 | new_jh = NULL; /* We consumed it */ |
| 1749 | set_buffer_jbd(bh); |
| 1750 | bh->b_private = jh; |
| 1751 | jh->b_bh = bh; |
| 1752 | get_bh(bh); |
| 1753 | BUFFER_TRACE(bh, "added journal_head"); |
| 1754 | } |
| 1755 | jh->b_jcount++; |
| 1756 | jbd_unlock_bh_journal_head(bh); |
| 1757 | if (new_jh) |
| 1758 | journal_free_journal_head(new_jh); |
| 1759 | return bh->b_private; |
| 1760 | } |
| 1761 | |
| 1762 | /* |
| 1763 | * Grab a ref against this buffer_head's journal_head. If it ended up not |
| 1764 | * having a journal_head, return NULL |
| 1765 | */ |
| 1766 | struct journal_head *journal_grab_journal_head(struct buffer_head *bh) |
| 1767 | { |
| 1768 | struct journal_head *jh = NULL; |
| 1769 | |
| 1770 | jbd_lock_bh_journal_head(bh); |
| 1771 | if (buffer_jbd(bh)) { |
| 1772 | jh = bh2jh(bh); |
| 1773 | jh->b_jcount++; |
| 1774 | } |
| 1775 | jbd_unlock_bh_journal_head(bh); |
| 1776 | return jh; |
| 1777 | } |
| 1778 | |
| 1779 | static void __journal_remove_journal_head(struct buffer_head *bh) |
| 1780 | { |
| 1781 | struct journal_head *jh = bh2jh(bh); |
| 1782 | |
| 1783 | J_ASSERT_JH(jh, jh->b_jcount >= 0); |
| 1784 | |
| 1785 | get_bh(bh); |
| 1786 | if (jh->b_jcount == 0) { |
| 1787 | if (jh->b_transaction == NULL && |
| 1788 | jh->b_next_transaction == NULL && |
| 1789 | jh->b_cp_transaction == NULL) { |
| 1790 | J_ASSERT_JH(jh, jh->b_jlist == BJ_None); |
| 1791 | J_ASSERT_BH(bh, buffer_jbd(bh)); |
| 1792 | J_ASSERT_BH(bh, jh2bh(jh) == bh); |
| 1793 | BUFFER_TRACE(bh, "remove journal_head"); |
| 1794 | if (jh->b_frozen_data) { |
| 1795 | printk(KERN_WARNING "%s: freeing " |
| 1796 | "b_frozen_data\n", |
Harvey Harrison | 08fc99b | 2008-04-28 02:16:16 -0700 | [diff] [blame] | 1797 | __func__); |
Mingming Cao | c089d49 | 2007-10-16 18:38:25 -0400 | [diff] [blame] | 1798 | jbd_free(jh->b_frozen_data, bh->b_size); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1799 | } |
| 1800 | if (jh->b_committed_data) { |
| 1801 | printk(KERN_WARNING "%s: freeing " |
| 1802 | "b_committed_data\n", |
Harvey Harrison | 08fc99b | 2008-04-28 02:16:16 -0700 | [diff] [blame] | 1803 | __func__); |
Mingming Cao | c089d49 | 2007-10-16 18:38:25 -0400 | [diff] [blame] | 1804 | jbd_free(jh->b_committed_data, bh->b_size); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1805 | } |
| 1806 | bh->b_private = NULL; |
| 1807 | jh->b_bh = NULL; /* debug, really */ |
| 1808 | clear_buffer_jbd(bh); |
| 1809 | __brelse(bh); |
| 1810 | journal_free_journal_head(jh); |
| 1811 | } else { |
| 1812 | BUFFER_TRACE(bh, "journal_head was locked"); |
| 1813 | } |
| 1814 | } |
| 1815 | } |
| 1816 | |
| 1817 | /* |
| 1818 | * journal_remove_journal_head(): if the buffer isn't attached to a transaction |
| 1819 | * and has a zero b_jcount then remove and release its journal_head. If we did |
| 1820 | * see that the buffer is not used by any transaction we also "logically" |
| 1821 | * decrement ->b_count. |
| 1822 | * |
| 1823 | * We in fact take an additional increment on ->b_count as a convenience, |
| 1824 | * because the caller usually wants to do additional things with the bh |
| 1825 | * after calling here. |
| 1826 | * The caller of journal_remove_journal_head() *must* run __brelse(bh) at some |
| 1827 | * time. Once the caller has run __brelse(), the buffer is eligible for |
| 1828 | * reaping by try_to_free_buffers(). |
| 1829 | */ |
| 1830 | void journal_remove_journal_head(struct buffer_head *bh) |
| 1831 | { |
| 1832 | jbd_lock_bh_journal_head(bh); |
| 1833 | __journal_remove_journal_head(bh); |
| 1834 | jbd_unlock_bh_journal_head(bh); |
| 1835 | } |
| 1836 | |
| 1837 | /* |
| 1838 | * Drop a reference on the passed journal_head. If it fell to zero then try to |
| 1839 | * release the journal_head from the buffer_head. |
| 1840 | */ |
| 1841 | void journal_put_journal_head(struct journal_head *jh) |
| 1842 | { |
| 1843 | struct buffer_head *bh = jh2bh(jh); |
| 1844 | |
| 1845 | jbd_lock_bh_journal_head(bh); |
| 1846 | J_ASSERT_JH(jh, jh->b_jcount > 0); |
| 1847 | --jh->b_jcount; |
| 1848 | if (!jh->b_jcount && !jh->b_transaction) { |
| 1849 | __journal_remove_journal_head(bh); |
| 1850 | __brelse(bh); |
| 1851 | } |
| 1852 | jbd_unlock_bh_journal_head(bh); |
| 1853 | } |
| 1854 | |
| 1855 | /* |
Jose R. Santos | c2a9159 | 2007-10-18 23:39:22 -0700 | [diff] [blame] | 1856 | * debugfs tunables |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1857 | */ |
Jose R. Santos | c2a9159 | 2007-10-18 23:39:22 -0700 | [diff] [blame] | 1858 | #ifdef CONFIG_JBD_DEBUG |
| 1859 | |
| 1860 | u8 journal_enable_debug __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1861 | EXPORT_SYMBOL(journal_enable_debug); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1862 | |
Jose R. Santos | c2a9159 | 2007-10-18 23:39:22 -0700 | [diff] [blame] | 1863 | static struct dentry *jbd_debugfs_dir; |
| 1864 | static struct dentry *jbd_debug; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1865 | |
Jose R. Santos | c2a9159 | 2007-10-18 23:39:22 -0700 | [diff] [blame] | 1866 | static void __init jbd_create_debugfs_entry(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1867 | { |
Jose R. Santos | c2a9159 | 2007-10-18 23:39:22 -0700 | [diff] [blame] | 1868 | jbd_debugfs_dir = debugfs_create_dir("jbd", NULL); |
| 1869 | if (jbd_debugfs_dir) |
| 1870 | jbd_debug = debugfs_create_u8("jbd-debug", S_IRUGO, |
| 1871 | jbd_debugfs_dir, |
| 1872 | &journal_enable_debug); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1873 | } |
| 1874 | |
Jose R. Santos | c2a9159 | 2007-10-18 23:39:22 -0700 | [diff] [blame] | 1875 | static void __exit jbd_remove_debugfs_entry(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1876 | { |
Jose R. Santos | c2a9159 | 2007-10-18 23:39:22 -0700 | [diff] [blame] | 1877 | debugfs_remove(jbd_debug); |
| 1878 | debugfs_remove(jbd_debugfs_dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1879 | } |
| 1880 | |
| 1881 | #else |
| 1882 | |
Jose R. Santos | c2a9159 | 2007-10-18 23:39:22 -0700 | [diff] [blame] | 1883 | static inline void jbd_create_debugfs_entry(void) |
| 1884 | { |
| 1885 | } |
| 1886 | |
| 1887 | static inline void jbd_remove_debugfs_entry(void) |
| 1888 | { |
| 1889 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1890 | |
| 1891 | #endif |
| 1892 | |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 1893 | struct kmem_cache *jbd_handle_cache; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1894 | |
| 1895 | static int __init journal_init_handle_cache(void) |
| 1896 | { |
| 1897 | jbd_handle_cache = kmem_cache_create("journal_handle", |
| 1898 | sizeof(handle_t), |
| 1899 | 0, /* offset */ |
Mel Gorman | e12ba74 | 2007-10-16 01:25:52 -0700 | [diff] [blame] | 1900 | SLAB_TEMPORARY, /* flags */ |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 1901 | NULL); /* ctor */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1902 | if (jbd_handle_cache == NULL) { |
| 1903 | printk(KERN_EMERG "JBD: failed to create handle cache\n"); |
| 1904 | return -ENOMEM; |
| 1905 | } |
| 1906 | return 0; |
| 1907 | } |
| 1908 | |
| 1909 | static void journal_destroy_handle_cache(void) |
| 1910 | { |
| 1911 | if (jbd_handle_cache) |
| 1912 | kmem_cache_destroy(jbd_handle_cache); |
| 1913 | } |
| 1914 | |
| 1915 | /* |
| 1916 | * Module startup and shutdown |
| 1917 | */ |
| 1918 | |
| 1919 | static int __init journal_init_caches(void) |
| 1920 | { |
| 1921 | int ret; |
| 1922 | |
| 1923 | ret = journal_init_revoke_caches(); |
| 1924 | if (ret == 0) |
| 1925 | ret = journal_init_journal_head_cache(); |
| 1926 | if (ret == 0) |
| 1927 | ret = journal_init_handle_cache(); |
| 1928 | return ret; |
| 1929 | } |
| 1930 | |
| 1931 | static void journal_destroy_caches(void) |
| 1932 | { |
| 1933 | journal_destroy_revoke_caches(); |
| 1934 | journal_destroy_journal_head_cache(); |
| 1935 | journal_destroy_handle_cache(); |
| 1936 | } |
| 1937 | |
| 1938 | static int __init journal_init(void) |
| 1939 | { |
| 1940 | int ret; |
| 1941 | |
Alexey Dobriyan | 2aed348 | 2006-09-27 01:49:28 -0700 | [diff] [blame] | 1942 | BUILD_BUG_ON(sizeof(struct journal_superblock_s) != 1024); |
Adrian Bunk | 022a4a7 | 2005-09-06 15:16:41 -0700 | [diff] [blame] | 1943 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1944 | ret = journal_init_caches(); |
| 1945 | if (ret != 0) |
| 1946 | journal_destroy_caches(); |
Jose R. Santos | c2a9159 | 2007-10-18 23:39:22 -0700 | [diff] [blame] | 1947 | jbd_create_debugfs_entry(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1948 | return ret; |
| 1949 | } |
| 1950 | |
| 1951 | static void __exit journal_exit(void) |
| 1952 | { |
| 1953 | #ifdef CONFIG_JBD_DEBUG |
| 1954 | int n = atomic_read(&nr_journal_heads); |
| 1955 | if (n) |
| 1956 | printk(KERN_EMERG "JBD: leaked %d journal_heads!\n", n); |
| 1957 | #endif |
Jose R. Santos | c2a9159 | 2007-10-18 23:39:22 -0700 | [diff] [blame] | 1958 | jbd_remove_debugfs_entry(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1959 | journal_destroy_caches(); |
| 1960 | } |
| 1961 | |
| 1962 | MODULE_LICENSE("GPL"); |
| 1963 | module_init(journal_init); |
| 1964 | module_exit(journal_exit); |
| 1965 | |