Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1 | /* |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 2 | * linux/fs/jbd2/commit.c |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -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 | * Journal commit routines for the generic filesystem journaling code; |
| 13 | * part of the ext2fs journaling system. |
| 14 | */ |
| 15 | |
| 16 | #include <linux/time.h> |
| 17 | #include <linux/fs.h> |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 18 | #include <linux/jbd2.h> |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 19 | #include <linux/errno.h> |
| 20 | #include <linux/slab.h> |
| 21 | #include <linux/mm.h> |
| 22 | #include <linux/pagemap.h> |
| 23 | #include <linux/smp_lock.h> |
| 24 | |
| 25 | /* |
| 26 | * Default IO end handler for temporary BJ_IO buffer_heads. |
| 27 | */ |
| 28 | static void journal_end_buffer_io_sync(struct buffer_head *bh, int uptodate) |
| 29 | { |
| 30 | BUFFER_TRACE(bh, ""); |
| 31 | if (uptodate) |
| 32 | set_buffer_uptodate(bh); |
| 33 | else |
| 34 | clear_buffer_uptodate(bh); |
| 35 | unlock_buffer(bh); |
| 36 | } |
| 37 | |
| 38 | /* |
| 39 | * When an ext3-ordered file is truncated, it is possible that many pages are |
| 40 | * not sucessfully freed, because they are attached to a committing transaction. |
| 41 | * After the transaction commits, these pages are left on the LRU, with no |
| 42 | * ->mapping, and with attached buffers. These pages are trivially reclaimable |
| 43 | * by the VM, but their apparent absence upsets the VM accounting, and it makes |
| 44 | * the numbers in /proc/meminfo look odd. |
| 45 | * |
| 46 | * So here, we have a buffer which has just come off the forget list. Look to |
| 47 | * see if we can strip all buffers from the backing page. |
| 48 | * |
| 49 | * Called under lock_journal(), and possibly under journal_datalist_lock. The |
| 50 | * caller provided us with a ref against the buffer, and we drop that here. |
| 51 | */ |
| 52 | static void release_buffer_page(struct buffer_head *bh) |
| 53 | { |
| 54 | struct page *page; |
| 55 | |
| 56 | if (buffer_dirty(bh)) |
| 57 | goto nope; |
| 58 | if (atomic_read(&bh->b_count) != 1) |
| 59 | goto nope; |
| 60 | page = bh->b_page; |
| 61 | if (!page) |
| 62 | goto nope; |
| 63 | if (page->mapping) |
| 64 | goto nope; |
| 65 | |
| 66 | /* OK, it's a truncated page */ |
| 67 | if (TestSetPageLocked(page)) |
| 68 | goto nope; |
| 69 | |
| 70 | page_cache_get(page); |
| 71 | __brelse(bh); |
| 72 | try_to_free_buffers(page); |
| 73 | unlock_page(page); |
| 74 | page_cache_release(page); |
| 75 | return; |
| 76 | |
| 77 | nope: |
| 78 | __brelse(bh); |
| 79 | } |
| 80 | |
| 81 | /* |
| 82 | * Try to acquire jbd_lock_bh_state() against the buffer, when j_list_lock is |
| 83 | * held. For ranking reasons we must trylock. If we lose, schedule away and |
| 84 | * return 0. j_list_lock is dropped in this case. |
| 85 | */ |
| 86 | static int inverted_lock(journal_t *journal, struct buffer_head *bh) |
| 87 | { |
| 88 | if (!jbd_trylock_bh_state(bh)) { |
| 89 | spin_unlock(&journal->j_list_lock); |
| 90 | schedule(); |
| 91 | return 0; |
| 92 | } |
| 93 | return 1; |
| 94 | } |
| 95 | |
| 96 | /* Done it all: now write the commit record. We should have |
| 97 | * cleaned up our previous buffers by now, so if we are in abort |
| 98 | * mode we can now just skip the rest of the journal write |
| 99 | * entirely. |
| 100 | * |
| 101 | * Returns 1 if the journal needs to be aborted or 0 on success |
| 102 | */ |
| 103 | static int journal_write_commit_record(journal_t *journal, |
| 104 | transaction_t *commit_transaction) |
| 105 | { |
| 106 | struct journal_head *descriptor; |
| 107 | struct buffer_head *bh; |
| 108 | int i, ret; |
| 109 | int barrier_done = 0; |
| 110 | |
| 111 | if (is_journal_aborted(journal)) |
| 112 | return 0; |
| 113 | |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 114 | descriptor = jbd2_journal_get_descriptor_buffer(journal); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 115 | if (!descriptor) |
| 116 | return 1; |
| 117 | |
| 118 | bh = jh2bh(descriptor); |
| 119 | |
| 120 | /* AKPM: buglet - add `i' to tmp! */ |
| 121 | for (i = 0; i < bh->b_size; i += 512) { |
| 122 | journal_header_t *tmp = (journal_header_t*)bh->b_data; |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 123 | tmp->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER); |
| 124 | tmp->h_blocktype = cpu_to_be32(JBD2_COMMIT_BLOCK); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 125 | tmp->h_sequence = cpu_to_be32(commit_transaction->t_tid); |
| 126 | } |
| 127 | |
| 128 | JBUFFER_TRACE(descriptor, "write commit block"); |
| 129 | set_buffer_dirty(bh); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 130 | if (journal->j_flags & JBD2_BARRIER) { |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 131 | set_buffer_ordered(bh); |
| 132 | barrier_done = 1; |
| 133 | } |
| 134 | ret = sync_dirty_buffer(bh); |
| 135 | /* is it possible for another commit to fail at roughly |
| 136 | * the same time as this one? If so, we don't want to |
| 137 | * trust the barrier flag in the super, but instead want |
| 138 | * to remember if we sent a barrier request |
| 139 | */ |
| 140 | if (ret == -EOPNOTSUPP && barrier_done) { |
| 141 | char b[BDEVNAME_SIZE]; |
| 142 | |
| 143 | printk(KERN_WARNING |
| 144 | "JBD: barrier-based sync failed on %s - " |
| 145 | "disabling barriers\n", |
| 146 | bdevname(journal->j_dev, b)); |
| 147 | spin_lock(&journal->j_state_lock); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 148 | journal->j_flags &= ~JBD2_BARRIER; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 149 | spin_unlock(&journal->j_state_lock); |
| 150 | |
| 151 | /* And try again, without the barrier */ |
| 152 | clear_buffer_ordered(bh); |
| 153 | set_buffer_uptodate(bh); |
| 154 | set_buffer_dirty(bh); |
| 155 | ret = sync_dirty_buffer(bh); |
| 156 | } |
| 157 | put_bh(bh); /* One for getblk() */ |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 158 | jbd2_journal_put_journal_head(descriptor); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 159 | |
| 160 | return (ret == -EIO); |
| 161 | } |
| 162 | |
| 163 | static void journal_do_submit_data(struct buffer_head **wbuf, int bufs) |
| 164 | { |
| 165 | int i; |
| 166 | |
| 167 | for (i = 0; i < bufs; i++) { |
| 168 | wbuf[i]->b_end_io = end_buffer_write_sync; |
| 169 | /* We use-up our safety reference in submit_bh() */ |
| 170 | submit_bh(WRITE, wbuf[i]); |
| 171 | } |
| 172 | } |
| 173 | |
| 174 | /* |
| 175 | * Submit all the data buffers to disk |
| 176 | */ |
| 177 | static void journal_submit_data_buffers(journal_t *journal, |
| 178 | transaction_t *commit_transaction) |
| 179 | { |
| 180 | struct journal_head *jh; |
| 181 | struct buffer_head *bh; |
| 182 | int locked; |
| 183 | int bufs = 0; |
| 184 | struct buffer_head **wbuf = journal->j_wbuf; |
| 185 | |
| 186 | /* |
| 187 | * Whenever we unlock the journal and sleep, things can get added |
| 188 | * onto ->t_sync_datalist, so we have to keep looping back to |
| 189 | * write_out_data until we *know* that the list is empty. |
| 190 | * |
| 191 | * Cleanup any flushed data buffers from the data list. Even in |
| 192 | * abort mode, we want to flush this out as soon as possible. |
| 193 | */ |
| 194 | write_out_data: |
| 195 | cond_resched(); |
| 196 | spin_lock(&journal->j_list_lock); |
| 197 | |
| 198 | while (commit_transaction->t_sync_datalist) { |
| 199 | jh = commit_transaction->t_sync_datalist; |
| 200 | bh = jh2bh(jh); |
| 201 | locked = 0; |
| 202 | |
| 203 | /* Get reference just to make sure buffer does not disappear |
| 204 | * when we are forced to drop various locks */ |
| 205 | get_bh(bh); |
| 206 | /* If the buffer is dirty, we need to submit IO and hence |
| 207 | * we need the buffer lock. We try to lock the buffer without |
| 208 | * blocking. If we fail, we need to drop j_list_lock and do |
| 209 | * blocking lock_buffer(). |
| 210 | */ |
| 211 | if (buffer_dirty(bh)) { |
| 212 | if (test_set_buffer_locked(bh)) { |
| 213 | BUFFER_TRACE(bh, "needs blocking lock"); |
| 214 | spin_unlock(&journal->j_list_lock); |
| 215 | /* Write out all data to prevent deadlocks */ |
| 216 | journal_do_submit_data(wbuf, bufs); |
| 217 | bufs = 0; |
| 218 | lock_buffer(bh); |
| 219 | spin_lock(&journal->j_list_lock); |
| 220 | } |
| 221 | locked = 1; |
| 222 | } |
| 223 | /* We have to get bh_state lock. Again out of order, sigh. */ |
| 224 | if (!inverted_lock(journal, bh)) { |
| 225 | jbd_lock_bh_state(bh); |
| 226 | spin_lock(&journal->j_list_lock); |
| 227 | } |
| 228 | /* Someone already cleaned up the buffer? */ |
| 229 | if (!buffer_jbd(bh) |
| 230 | || jh->b_transaction != commit_transaction |
| 231 | || jh->b_jlist != BJ_SyncData) { |
| 232 | jbd_unlock_bh_state(bh); |
| 233 | if (locked) |
| 234 | unlock_buffer(bh); |
| 235 | BUFFER_TRACE(bh, "already cleaned up"); |
| 236 | put_bh(bh); |
| 237 | continue; |
| 238 | } |
| 239 | if (locked && test_clear_buffer_dirty(bh)) { |
| 240 | BUFFER_TRACE(bh, "needs writeout, adding to array"); |
| 241 | wbuf[bufs++] = bh; |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 242 | __jbd2_journal_file_buffer(jh, commit_transaction, |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 243 | BJ_Locked); |
| 244 | jbd_unlock_bh_state(bh); |
| 245 | if (bufs == journal->j_wbufsize) { |
| 246 | spin_unlock(&journal->j_list_lock); |
| 247 | journal_do_submit_data(wbuf, bufs); |
| 248 | bufs = 0; |
| 249 | goto write_out_data; |
| 250 | } |
| 251 | } |
| 252 | else { |
| 253 | BUFFER_TRACE(bh, "writeout complete: unfile"); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 254 | __jbd2_journal_unfile_buffer(jh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 255 | jbd_unlock_bh_state(bh); |
| 256 | if (locked) |
| 257 | unlock_buffer(bh); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 258 | jbd2_journal_remove_journal_head(bh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 259 | /* Once for our safety reference, once for |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 260 | * jbd2_journal_remove_journal_head() */ |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 261 | put_bh(bh); |
| 262 | put_bh(bh); |
| 263 | } |
| 264 | |
| 265 | if (lock_need_resched(&journal->j_list_lock)) { |
| 266 | spin_unlock(&journal->j_list_lock); |
| 267 | goto write_out_data; |
| 268 | } |
| 269 | } |
| 270 | spin_unlock(&journal->j_list_lock); |
| 271 | journal_do_submit_data(wbuf, bufs); |
| 272 | } |
| 273 | |
Zach Brown | b517bea | 2006-10-11 01:21:08 -0700 | [diff] [blame] | 274 | static inline void write_tag_block(int tag_bytes, journal_block_tag_t *tag, |
| 275 | sector_t block) |
| 276 | { |
| 277 | tag->t_blocknr = cpu_to_be32(block & (u32)~0); |
| 278 | if (tag_bytes > JBD_TAG_SIZE32) |
| 279 | tag->t_blocknr_high = cpu_to_be32((block >> 31) >> 1); |
| 280 | } |
| 281 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 282 | /* |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 283 | * jbd2_journal_commit_transaction |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 284 | * |
| 285 | * The primary function for committing a transaction to the log. This |
| 286 | * function is called by the journal thread to begin a complete commit. |
| 287 | */ |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 288 | void jbd2_journal_commit_transaction(journal_t *journal) |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 289 | { |
| 290 | transaction_t *commit_transaction; |
| 291 | struct journal_head *jh, *new_jh, *descriptor; |
| 292 | struct buffer_head **wbuf = journal->j_wbuf; |
| 293 | int bufs; |
| 294 | int flags; |
| 295 | int err; |
Mingming Cao | 2997176 | 2006-10-11 01:21:09 -0700 | [diff] [blame] | 296 | sector_t blocknr; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 297 | char *tagp = NULL; |
| 298 | journal_header_t *header; |
| 299 | journal_block_tag_t *tag = NULL; |
| 300 | int space_left = 0; |
| 301 | int first_tag = 0; |
| 302 | int tag_flag; |
| 303 | int i; |
Zach Brown | b517bea | 2006-10-11 01:21:08 -0700 | [diff] [blame] | 304 | int tag_bytes = journal_tag_bytes(journal); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 305 | |
| 306 | /* |
| 307 | * First job: lock down the current transaction and wait for |
| 308 | * all outstanding updates to complete. |
| 309 | */ |
| 310 | |
| 311 | #ifdef COMMIT_STATS |
| 312 | spin_lock(&journal->j_list_lock); |
| 313 | summarise_journal_usage(journal); |
| 314 | spin_unlock(&journal->j_list_lock); |
| 315 | #endif |
| 316 | |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 317 | /* Do we need to erase the effects of a prior jbd2_journal_flush? */ |
| 318 | if (journal->j_flags & JBD2_FLUSHED) { |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 319 | jbd_debug(3, "super block updated\n"); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 320 | jbd2_journal_update_superblock(journal, 1); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 321 | } else { |
| 322 | jbd_debug(3, "superblock not updated\n"); |
| 323 | } |
| 324 | |
| 325 | J_ASSERT(journal->j_running_transaction != NULL); |
| 326 | J_ASSERT(journal->j_committing_transaction == NULL); |
| 327 | |
| 328 | commit_transaction = journal->j_running_transaction; |
| 329 | J_ASSERT(commit_transaction->t_state == T_RUNNING); |
| 330 | |
| 331 | jbd_debug(1, "JBD: starting commit of transaction %d\n", |
| 332 | commit_transaction->t_tid); |
| 333 | |
| 334 | spin_lock(&journal->j_state_lock); |
| 335 | commit_transaction->t_state = T_LOCKED; |
| 336 | |
| 337 | spin_lock(&commit_transaction->t_handle_lock); |
| 338 | while (commit_transaction->t_updates) { |
| 339 | DEFINE_WAIT(wait); |
| 340 | |
| 341 | prepare_to_wait(&journal->j_wait_updates, &wait, |
| 342 | TASK_UNINTERRUPTIBLE); |
| 343 | if (commit_transaction->t_updates) { |
| 344 | spin_unlock(&commit_transaction->t_handle_lock); |
| 345 | spin_unlock(&journal->j_state_lock); |
| 346 | schedule(); |
| 347 | spin_lock(&journal->j_state_lock); |
| 348 | spin_lock(&commit_transaction->t_handle_lock); |
| 349 | } |
| 350 | finish_wait(&journal->j_wait_updates, &wait); |
| 351 | } |
| 352 | spin_unlock(&commit_transaction->t_handle_lock); |
| 353 | |
| 354 | J_ASSERT (commit_transaction->t_outstanding_credits <= |
| 355 | journal->j_max_transaction_buffers); |
| 356 | |
| 357 | /* |
| 358 | * First thing we are allowed to do is to discard any remaining |
| 359 | * BJ_Reserved buffers. Note, it is _not_ permissible to assume |
| 360 | * that there are no such buffers: if a large filesystem |
| 361 | * operation like a truncate needs to split itself over multiple |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 362 | * transactions, then it may try to do a jbd2_journal_restart() while |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 363 | * there are still BJ_Reserved buffers outstanding. These must |
| 364 | * be released cleanly from the current transaction. |
| 365 | * |
| 366 | * In this case, the filesystem must still reserve write access |
| 367 | * again before modifying the buffer in the new transaction, but |
| 368 | * we do not require it to remember exactly which old buffers it |
| 369 | * has reserved. This is consistent with the existing behaviour |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 370 | * that multiple jbd2_journal_get_write_access() calls to the same |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 371 | * buffer are perfectly permissable. |
| 372 | */ |
| 373 | while (commit_transaction->t_reserved_list) { |
| 374 | jh = commit_transaction->t_reserved_list; |
| 375 | JBUFFER_TRACE(jh, "reserved, unused: refile"); |
| 376 | /* |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 377 | * A jbd2_journal_get_undo_access()+jbd2_journal_release_buffer() may |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 378 | * leave undo-committed data. |
| 379 | */ |
| 380 | if (jh->b_committed_data) { |
| 381 | struct buffer_head *bh = jh2bh(jh); |
| 382 | |
| 383 | jbd_lock_bh_state(bh); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 384 | jbd2_slab_free(jh->b_committed_data, bh->b_size); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 385 | jh->b_committed_data = NULL; |
| 386 | jbd_unlock_bh_state(bh); |
| 387 | } |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 388 | jbd2_journal_refile_buffer(journal, jh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 389 | } |
| 390 | |
| 391 | /* |
| 392 | * Now try to drop any written-back buffers from the journal's |
| 393 | * checkpoint lists. We do this *before* commit because it potentially |
| 394 | * frees some memory |
| 395 | */ |
| 396 | spin_lock(&journal->j_list_lock); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 397 | __jbd2_journal_clean_checkpoint_list(journal); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 398 | spin_unlock(&journal->j_list_lock); |
| 399 | |
| 400 | jbd_debug (3, "JBD: commit phase 1\n"); |
| 401 | |
| 402 | /* |
| 403 | * Switch to a new revoke table. |
| 404 | */ |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 405 | jbd2_journal_switch_revoke_table(journal); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 406 | |
| 407 | commit_transaction->t_state = T_FLUSH; |
| 408 | journal->j_committing_transaction = commit_transaction; |
| 409 | journal->j_running_transaction = NULL; |
| 410 | commit_transaction->t_log_start = journal->j_head; |
| 411 | wake_up(&journal->j_wait_transaction_locked); |
| 412 | spin_unlock(&journal->j_state_lock); |
| 413 | |
| 414 | jbd_debug (3, "JBD: commit phase 2\n"); |
| 415 | |
| 416 | /* |
| 417 | * First, drop modified flag: all accesses to the buffers |
| 418 | * will be tracked for a new trasaction only -bzzz |
| 419 | */ |
| 420 | spin_lock(&journal->j_list_lock); |
| 421 | if (commit_transaction->t_buffers) { |
| 422 | new_jh = jh = commit_transaction->t_buffers->b_tnext; |
| 423 | do { |
| 424 | J_ASSERT_JH(new_jh, new_jh->b_modified == 1 || |
| 425 | new_jh->b_modified == 0); |
| 426 | new_jh->b_modified = 0; |
| 427 | new_jh = new_jh->b_tnext; |
| 428 | } while (new_jh != jh); |
| 429 | } |
| 430 | spin_unlock(&journal->j_list_lock); |
| 431 | |
| 432 | /* |
| 433 | * Now start flushing things to disk, in the order they appear |
| 434 | * on the transaction lists. Data blocks go first. |
| 435 | */ |
| 436 | err = 0; |
| 437 | journal_submit_data_buffers(journal, commit_transaction); |
| 438 | |
| 439 | /* |
| 440 | * Wait for all previously submitted IO to complete. |
| 441 | */ |
| 442 | spin_lock(&journal->j_list_lock); |
| 443 | while (commit_transaction->t_locked_list) { |
| 444 | struct buffer_head *bh; |
| 445 | |
| 446 | jh = commit_transaction->t_locked_list->b_tprev; |
| 447 | bh = jh2bh(jh); |
| 448 | get_bh(bh); |
| 449 | if (buffer_locked(bh)) { |
| 450 | spin_unlock(&journal->j_list_lock); |
| 451 | wait_on_buffer(bh); |
| 452 | if (unlikely(!buffer_uptodate(bh))) |
| 453 | err = -EIO; |
| 454 | spin_lock(&journal->j_list_lock); |
| 455 | } |
| 456 | if (!inverted_lock(journal, bh)) { |
| 457 | put_bh(bh); |
| 458 | spin_lock(&journal->j_list_lock); |
| 459 | continue; |
| 460 | } |
| 461 | if (buffer_jbd(bh) && jh->b_jlist == BJ_Locked) { |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 462 | __jbd2_journal_unfile_buffer(jh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 463 | jbd_unlock_bh_state(bh); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 464 | jbd2_journal_remove_journal_head(bh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 465 | put_bh(bh); |
| 466 | } else { |
| 467 | jbd_unlock_bh_state(bh); |
| 468 | } |
| 469 | put_bh(bh); |
| 470 | cond_resched_lock(&journal->j_list_lock); |
| 471 | } |
| 472 | spin_unlock(&journal->j_list_lock); |
| 473 | |
| 474 | if (err) |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 475 | __jbd2_journal_abort_hard(journal); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 476 | |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 477 | jbd2_journal_write_revoke_records(journal, commit_transaction); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 478 | |
| 479 | jbd_debug(3, "JBD: commit phase 2\n"); |
| 480 | |
| 481 | /* |
| 482 | * If we found any dirty or locked buffers, then we should have |
| 483 | * looped back up to the write_out_data label. If there weren't |
| 484 | * any then journal_clean_data_list should have wiped the list |
| 485 | * clean by now, so check that it is in fact empty. |
| 486 | */ |
| 487 | J_ASSERT (commit_transaction->t_sync_datalist == NULL); |
| 488 | |
| 489 | jbd_debug (3, "JBD: commit phase 3\n"); |
| 490 | |
| 491 | /* |
| 492 | * Way to go: we have now written out all of the data for a |
| 493 | * transaction! Now comes the tricky part: we need to write out |
| 494 | * metadata. Loop over the transaction's entire buffer list: |
| 495 | */ |
| 496 | commit_transaction->t_state = T_COMMIT; |
| 497 | |
| 498 | descriptor = NULL; |
| 499 | bufs = 0; |
| 500 | while (commit_transaction->t_buffers) { |
| 501 | |
| 502 | /* Find the next buffer to be journaled... */ |
| 503 | |
| 504 | jh = commit_transaction->t_buffers; |
| 505 | |
| 506 | /* If we're in abort mode, we just un-journal the buffer and |
| 507 | release it for background writing. */ |
| 508 | |
| 509 | if (is_journal_aborted(journal)) { |
| 510 | JBUFFER_TRACE(jh, "journal is aborting: refile"); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 511 | jbd2_journal_refile_buffer(journal, jh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 512 | /* If that was the last one, we need to clean up |
| 513 | * any descriptor buffers which may have been |
| 514 | * already allocated, even if we are now |
| 515 | * aborting. */ |
| 516 | if (!commit_transaction->t_buffers) |
| 517 | goto start_journal_io; |
| 518 | continue; |
| 519 | } |
| 520 | |
| 521 | /* Make sure we have a descriptor block in which to |
| 522 | record the metadata buffer. */ |
| 523 | |
| 524 | if (!descriptor) { |
| 525 | struct buffer_head *bh; |
| 526 | |
| 527 | J_ASSERT (bufs == 0); |
| 528 | |
| 529 | jbd_debug(4, "JBD: get descriptor\n"); |
| 530 | |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 531 | descriptor = jbd2_journal_get_descriptor_buffer(journal); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 532 | if (!descriptor) { |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 533 | __jbd2_journal_abort_hard(journal); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 534 | continue; |
| 535 | } |
| 536 | |
| 537 | bh = jh2bh(descriptor); |
| 538 | jbd_debug(4, "JBD: got buffer %llu (%p)\n", |
| 539 | (unsigned long long)bh->b_blocknr, bh->b_data); |
| 540 | header = (journal_header_t *)&bh->b_data[0]; |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 541 | header->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER); |
| 542 | header->h_blocktype = cpu_to_be32(JBD2_DESCRIPTOR_BLOCK); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 543 | header->h_sequence = cpu_to_be32(commit_transaction->t_tid); |
| 544 | |
| 545 | tagp = &bh->b_data[sizeof(journal_header_t)]; |
| 546 | space_left = bh->b_size - sizeof(journal_header_t); |
| 547 | first_tag = 1; |
| 548 | set_buffer_jwrite(bh); |
| 549 | set_buffer_dirty(bh); |
| 550 | wbuf[bufs++] = bh; |
| 551 | |
| 552 | /* Record it so that we can wait for IO |
| 553 | completion later */ |
| 554 | BUFFER_TRACE(bh, "ph3: file as descriptor"); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 555 | jbd2_journal_file_buffer(descriptor, commit_transaction, |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 556 | BJ_LogCtl); |
| 557 | } |
| 558 | |
| 559 | /* Where is the buffer to be written? */ |
| 560 | |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 561 | err = jbd2_journal_next_log_block(journal, &blocknr); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 562 | /* If the block mapping failed, just abandon the buffer |
| 563 | and repeat this loop: we'll fall into the |
| 564 | refile-on-abort condition above. */ |
| 565 | if (err) { |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 566 | __jbd2_journal_abort_hard(journal); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 567 | continue; |
| 568 | } |
| 569 | |
| 570 | /* |
| 571 | * start_this_handle() uses t_outstanding_credits to determine |
| 572 | * the free space in the log, but this counter is changed |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 573 | * by jbd2_journal_next_log_block() also. |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 574 | */ |
| 575 | commit_transaction->t_outstanding_credits--; |
| 576 | |
| 577 | /* Bump b_count to prevent truncate from stumbling over |
| 578 | the shadowed buffer! @@@ This can go if we ever get |
| 579 | rid of the BJ_IO/BJ_Shadow pairing of buffers. */ |
| 580 | atomic_inc(&jh2bh(jh)->b_count); |
| 581 | |
| 582 | /* Make a temporary IO buffer with which to write it out |
| 583 | (this will requeue both the metadata buffer and the |
| 584 | temporary IO buffer). new_bh goes on BJ_IO*/ |
| 585 | |
| 586 | set_bit(BH_JWrite, &jh2bh(jh)->b_state); |
| 587 | /* |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 588 | * akpm: jbd2_journal_write_metadata_buffer() sets |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 589 | * new_bh->b_transaction to commit_transaction. |
| 590 | * We need to clean this up before we release new_bh |
| 591 | * (which is of type BJ_IO) |
| 592 | */ |
| 593 | JBUFFER_TRACE(jh, "ph3: write metadata"); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 594 | flags = jbd2_journal_write_metadata_buffer(commit_transaction, |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 595 | jh, &new_jh, blocknr); |
| 596 | set_bit(BH_JWrite, &jh2bh(new_jh)->b_state); |
| 597 | wbuf[bufs++] = jh2bh(new_jh); |
| 598 | |
| 599 | /* Record the new block's tag in the current descriptor |
| 600 | buffer */ |
| 601 | |
| 602 | tag_flag = 0; |
| 603 | if (flags & 1) |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 604 | tag_flag |= JBD2_FLAG_ESCAPE; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 605 | if (!first_tag) |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 606 | tag_flag |= JBD2_FLAG_SAME_UUID; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 607 | |
| 608 | tag = (journal_block_tag_t *) tagp; |
Zach Brown | b517bea | 2006-10-11 01:21:08 -0700 | [diff] [blame] | 609 | write_tag_block(tag_bytes, tag, jh2bh(jh)->b_blocknr); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 610 | tag->t_flags = cpu_to_be32(tag_flag); |
Zach Brown | b517bea | 2006-10-11 01:21:08 -0700 | [diff] [blame] | 611 | tagp += tag_bytes; |
| 612 | space_left -= tag_bytes; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 613 | |
| 614 | if (first_tag) { |
| 615 | memcpy (tagp, journal->j_uuid, 16); |
| 616 | tagp += 16; |
| 617 | space_left -= 16; |
| 618 | first_tag = 0; |
| 619 | } |
| 620 | |
| 621 | /* If there's no more to do, or if the descriptor is full, |
| 622 | let the IO rip! */ |
| 623 | |
| 624 | if (bufs == journal->j_wbufsize || |
| 625 | commit_transaction->t_buffers == NULL || |
Zach Brown | b517bea | 2006-10-11 01:21:08 -0700 | [diff] [blame] | 626 | space_left < tag_bytes + 16) { |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 627 | |
| 628 | jbd_debug(4, "JBD: Submit %d IOs\n", bufs); |
| 629 | |
| 630 | /* Write an end-of-descriptor marker before |
| 631 | submitting the IOs. "tag" still points to |
| 632 | the last tag we set up. */ |
| 633 | |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 634 | tag->t_flags |= cpu_to_be32(JBD2_FLAG_LAST_TAG); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 635 | |
| 636 | start_journal_io: |
| 637 | for (i = 0; i < bufs; i++) { |
| 638 | struct buffer_head *bh = wbuf[i]; |
| 639 | lock_buffer(bh); |
| 640 | clear_buffer_dirty(bh); |
| 641 | set_buffer_uptodate(bh); |
| 642 | bh->b_end_io = journal_end_buffer_io_sync; |
| 643 | submit_bh(WRITE, bh); |
| 644 | } |
| 645 | cond_resched(); |
| 646 | |
| 647 | /* Force a new descriptor to be generated next |
| 648 | time round the loop. */ |
| 649 | descriptor = NULL; |
| 650 | bufs = 0; |
| 651 | } |
| 652 | } |
| 653 | |
| 654 | /* Lo and behold: we have just managed to send a transaction to |
| 655 | the log. Before we can commit it, wait for the IO so far to |
| 656 | complete. Control buffers being written are on the |
| 657 | transaction's t_log_list queue, and metadata buffers are on |
| 658 | the t_iobuf_list queue. |
| 659 | |
| 660 | Wait for the buffers in reverse order. That way we are |
| 661 | less likely to be woken up until all IOs have completed, and |
| 662 | so we incur less scheduling load. |
| 663 | */ |
| 664 | |
| 665 | jbd_debug(3, "JBD: commit phase 4\n"); |
| 666 | |
| 667 | /* |
| 668 | * akpm: these are BJ_IO, and j_list_lock is not needed. |
| 669 | * See __journal_try_to_free_buffer. |
| 670 | */ |
| 671 | wait_for_iobuf: |
| 672 | while (commit_transaction->t_iobuf_list != NULL) { |
| 673 | struct buffer_head *bh; |
| 674 | |
| 675 | jh = commit_transaction->t_iobuf_list->b_tprev; |
| 676 | bh = jh2bh(jh); |
| 677 | if (buffer_locked(bh)) { |
| 678 | wait_on_buffer(bh); |
| 679 | goto wait_for_iobuf; |
| 680 | } |
| 681 | if (cond_resched()) |
| 682 | goto wait_for_iobuf; |
| 683 | |
| 684 | if (unlikely(!buffer_uptodate(bh))) |
| 685 | err = -EIO; |
| 686 | |
| 687 | clear_buffer_jwrite(bh); |
| 688 | |
| 689 | JBUFFER_TRACE(jh, "ph4: unfile after journal write"); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 690 | jbd2_journal_unfile_buffer(journal, jh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 691 | |
| 692 | /* |
| 693 | * ->t_iobuf_list should contain only dummy buffer_heads |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 694 | * which were created by jbd2_journal_write_metadata_buffer(). |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 695 | */ |
| 696 | BUFFER_TRACE(bh, "dumping temporary bh"); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 697 | jbd2_journal_put_journal_head(jh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 698 | __brelse(bh); |
| 699 | J_ASSERT_BH(bh, atomic_read(&bh->b_count) == 0); |
| 700 | free_buffer_head(bh); |
| 701 | |
| 702 | /* We also have to unlock and free the corresponding |
| 703 | shadowed buffer */ |
| 704 | jh = commit_transaction->t_shadow_list->b_tprev; |
| 705 | bh = jh2bh(jh); |
| 706 | clear_bit(BH_JWrite, &bh->b_state); |
| 707 | J_ASSERT_BH(bh, buffer_jbddirty(bh)); |
| 708 | |
| 709 | /* The metadata is now released for reuse, but we need |
| 710 | to remember it against this transaction so that when |
| 711 | we finally commit, we can do any checkpointing |
| 712 | required. */ |
| 713 | JBUFFER_TRACE(jh, "file as BJ_Forget"); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 714 | jbd2_journal_file_buffer(jh, commit_transaction, BJ_Forget); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 715 | /* Wake up any transactions which were waiting for this |
| 716 | IO to complete */ |
| 717 | wake_up_bit(&bh->b_state, BH_Unshadow); |
| 718 | JBUFFER_TRACE(jh, "brelse shadowed buffer"); |
| 719 | __brelse(bh); |
| 720 | } |
| 721 | |
| 722 | J_ASSERT (commit_transaction->t_shadow_list == NULL); |
| 723 | |
| 724 | jbd_debug(3, "JBD: commit phase 5\n"); |
| 725 | |
| 726 | /* Here we wait for the revoke record and descriptor record buffers */ |
| 727 | wait_for_ctlbuf: |
| 728 | while (commit_transaction->t_log_list != NULL) { |
| 729 | struct buffer_head *bh; |
| 730 | |
| 731 | jh = commit_transaction->t_log_list->b_tprev; |
| 732 | bh = jh2bh(jh); |
| 733 | if (buffer_locked(bh)) { |
| 734 | wait_on_buffer(bh); |
| 735 | goto wait_for_ctlbuf; |
| 736 | } |
| 737 | if (cond_resched()) |
| 738 | goto wait_for_ctlbuf; |
| 739 | |
| 740 | if (unlikely(!buffer_uptodate(bh))) |
| 741 | err = -EIO; |
| 742 | |
| 743 | BUFFER_TRACE(bh, "ph5: control buffer writeout done: unfile"); |
| 744 | clear_buffer_jwrite(bh); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 745 | jbd2_journal_unfile_buffer(journal, jh); |
| 746 | jbd2_journal_put_journal_head(jh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 747 | __brelse(bh); /* One for getblk */ |
| 748 | /* AKPM: bforget here */ |
| 749 | } |
| 750 | |
| 751 | jbd_debug(3, "JBD: commit phase 6\n"); |
| 752 | |
| 753 | if (journal_write_commit_record(journal, commit_transaction)) |
| 754 | err = -EIO; |
| 755 | |
| 756 | if (err) |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 757 | __jbd2_journal_abort_hard(journal); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 758 | |
| 759 | /* End of a transaction! Finally, we can do checkpoint |
| 760 | processing: any buffers committed as a result of this |
| 761 | transaction can be removed from any checkpoint list it was on |
| 762 | before. */ |
| 763 | |
| 764 | jbd_debug(3, "JBD: commit phase 7\n"); |
| 765 | |
| 766 | J_ASSERT(commit_transaction->t_sync_datalist == NULL); |
| 767 | J_ASSERT(commit_transaction->t_buffers == NULL); |
| 768 | J_ASSERT(commit_transaction->t_checkpoint_list == NULL); |
| 769 | J_ASSERT(commit_transaction->t_iobuf_list == NULL); |
| 770 | J_ASSERT(commit_transaction->t_shadow_list == NULL); |
| 771 | J_ASSERT(commit_transaction->t_log_list == NULL); |
| 772 | |
| 773 | restart_loop: |
| 774 | /* |
| 775 | * As there are other places (journal_unmap_buffer()) adding buffers |
| 776 | * to this list we have to be careful and hold the j_list_lock. |
| 777 | */ |
| 778 | spin_lock(&journal->j_list_lock); |
| 779 | while (commit_transaction->t_forget) { |
| 780 | transaction_t *cp_transaction; |
| 781 | struct buffer_head *bh; |
| 782 | |
| 783 | jh = commit_transaction->t_forget; |
| 784 | spin_unlock(&journal->j_list_lock); |
| 785 | bh = jh2bh(jh); |
| 786 | jbd_lock_bh_state(bh); |
| 787 | J_ASSERT_JH(jh, jh->b_transaction == commit_transaction || |
| 788 | jh->b_transaction == journal->j_running_transaction); |
| 789 | |
| 790 | /* |
| 791 | * If there is undo-protected committed data against |
| 792 | * this buffer, then we can remove it now. If it is a |
| 793 | * buffer needing such protection, the old frozen_data |
| 794 | * field now points to a committed version of the |
| 795 | * buffer, so rotate that field to the new committed |
| 796 | * data. |
| 797 | * |
| 798 | * Otherwise, we can just throw away the frozen data now. |
| 799 | */ |
| 800 | if (jh->b_committed_data) { |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 801 | jbd2_slab_free(jh->b_committed_data, bh->b_size); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 802 | jh->b_committed_data = NULL; |
| 803 | if (jh->b_frozen_data) { |
| 804 | jh->b_committed_data = jh->b_frozen_data; |
| 805 | jh->b_frozen_data = NULL; |
| 806 | } |
| 807 | } else if (jh->b_frozen_data) { |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 808 | jbd2_slab_free(jh->b_frozen_data, bh->b_size); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 809 | jh->b_frozen_data = NULL; |
| 810 | } |
| 811 | |
| 812 | spin_lock(&journal->j_list_lock); |
| 813 | cp_transaction = jh->b_cp_transaction; |
| 814 | if (cp_transaction) { |
| 815 | JBUFFER_TRACE(jh, "remove from old cp transaction"); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 816 | __jbd2_journal_remove_checkpoint(jh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 817 | } |
| 818 | |
| 819 | /* Only re-checkpoint the buffer_head if it is marked |
| 820 | * dirty. If the buffer was added to the BJ_Forget list |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 821 | * by jbd2_journal_forget, it may no longer be dirty and |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 822 | * there's no point in keeping a checkpoint record for |
| 823 | * it. */ |
| 824 | |
| 825 | /* A buffer which has been freed while still being |
| 826 | * journaled by a previous transaction may end up still |
| 827 | * being dirty here, but we want to avoid writing back |
| 828 | * that buffer in the future now that the last use has |
| 829 | * been committed. That's not only a performance gain, |
| 830 | * it also stops aliasing problems if the buffer is left |
| 831 | * behind for writeback and gets reallocated for another |
| 832 | * use in a different page. */ |
| 833 | if (buffer_freed(bh)) { |
| 834 | clear_buffer_freed(bh); |
| 835 | clear_buffer_jbddirty(bh); |
| 836 | } |
| 837 | |
| 838 | if (buffer_jbddirty(bh)) { |
| 839 | JBUFFER_TRACE(jh, "add to new checkpointing trans"); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 840 | __jbd2_journal_insert_checkpoint(jh, commit_transaction); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 841 | JBUFFER_TRACE(jh, "refile for checkpoint writeback"); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 842 | __jbd2_journal_refile_buffer(jh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 843 | jbd_unlock_bh_state(bh); |
| 844 | } else { |
| 845 | J_ASSERT_BH(bh, !buffer_dirty(bh)); |
| 846 | /* The buffer on BJ_Forget list and not jbddirty means |
| 847 | * it has been freed by this transaction and hence it |
| 848 | * could not have been reallocated until this |
| 849 | * transaction has committed. *BUT* it could be |
| 850 | * reallocated once we have written all the data to |
| 851 | * disk and before we process the buffer on BJ_Forget |
| 852 | * list. */ |
| 853 | JBUFFER_TRACE(jh, "refile or unfile freed buffer"); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 854 | __jbd2_journal_refile_buffer(jh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 855 | if (!jh->b_transaction) { |
| 856 | jbd_unlock_bh_state(bh); |
| 857 | /* needs a brelse */ |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 858 | jbd2_journal_remove_journal_head(bh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 859 | release_buffer_page(bh); |
| 860 | } else |
| 861 | jbd_unlock_bh_state(bh); |
| 862 | } |
| 863 | cond_resched_lock(&journal->j_list_lock); |
| 864 | } |
| 865 | spin_unlock(&journal->j_list_lock); |
| 866 | /* |
| 867 | * This is a bit sleazy. We borrow j_list_lock to protect |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 868 | * journal->j_committing_transaction in __jbd2_journal_remove_checkpoint. |
| 869 | * Really, __jbd2_journal_remove_checkpoint should be using j_state_lock but |
| 870 | * it's a bit hassle to hold that across __jbd2_journal_remove_checkpoint |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 871 | */ |
| 872 | spin_lock(&journal->j_state_lock); |
| 873 | spin_lock(&journal->j_list_lock); |
| 874 | /* |
| 875 | * Now recheck if some buffers did not get attached to the transaction |
| 876 | * while the lock was dropped... |
| 877 | */ |
| 878 | if (commit_transaction->t_forget) { |
| 879 | spin_unlock(&journal->j_list_lock); |
| 880 | spin_unlock(&journal->j_state_lock); |
| 881 | goto restart_loop; |
| 882 | } |
| 883 | |
| 884 | /* Done with this transaction! */ |
| 885 | |
| 886 | jbd_debug(3, "JBD: commit phase 8\n"); |
| 887 | |
| 888 | J_ASSERT(commit_transaction->t_state == T_COMMIT); |
| 889 | |
| 890 | commit_transaction->t_state = T_FINISHED; |
| 891 | J_ASSERT(commit_transaction == journal->j_committing_transaction); |
| 892 | journal->j_commit_sequence = commit_transaction->t_tid; |
| 893 | journal->j_committing_transaction = NULL; |
| 894 | spin_unlock(&journal->j_state_lock); |
| 895 | |
| 896 | if (commit_transaction->t_checkpoint_list == NULL) { |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 897 | __jbd2_journal_drop_transaction(journal, commit_transaction); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 898 | } else { |
| 899 | if (journal->j_checkpoint_transactions == NULL) { |
| 900 | journal->j_checkpoint_transactions = commit_transaction; |
| 901 | commit_transaction->t_cpnext = commit_transaction; |
| 902 | commit_transaction->t_cpprev = commit_transaction; |
| 903 | } else { |
| 904 | commit_transaction->t_cpnext = |
| 905 | journal->j_checkpoint_transactions; |
| 906 | commit_transaction->t_cpprev = |
| 907 | commit_transaction->t_cpnext->t_cpprev; |
| 908 | commit_transaction->t_cpnext->t_cpprev = |
| 909 | commit_transaction; |
| 910 | commit_transaction->t_cpprev->t_cpnext = |
| 911 | commit_transaction; |
| 912 | } |
| 913 | } |
| 914 | spin_unlock(&journal->j_list_lock); |
| 915 | |
| 916 | jbd_debug(1, "JBD: commit %d complete, head %d\n", |
| 917 | journal->j_commit_sequence, journal->j_tail_sequence); |
| 918 | |
| 919 | wake_up(&journal->j_wait_done_commit); |
| 920 | } |