Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1 | /* |
Uwe Kleine-König | 5886269 | 2007-05-09 07:51:49 +0200 | [diff] [blame] | 2 | * linux/fs/jbd2/transaction.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 | * Generic filesystem transaction handling code; part of the ext2fs |
| 13 | * journaling system. |
| 14 | * |
| 15 | * This file manages transactions (compound commits managed by the |
| 16 | * journaling code) and handles (individual atomic operations by the |
| 17 | * filesystem). |
| 18 | */ |
| 19 | |
| 20 | #include <linux/time.h> |
| 21 | #include <linux/fs.h> |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 22 | #include <linux/jbd2.h> |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 23 | #include <linux/errno.h> |
| 24 | #include <linux/slab.h> |
| 25 | #include <linux/timer.h> |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 26 | #include <linux/mm.h> |
| 27 | #include <linux/highmem.h> |
Josef Bacik | e07f718 | 2008-11-26 01:14:26 -0500 | [diff] [blame] | 28 | #include <linux/hrtimer.h> |
Theodore Ts'o | 47def82 | 2010-07-27 11:56:05 -0400 | [diff] [blame] | 29 | #include <linux/backing-dev.h> |
Randy Dunlap | 4470575 | 2011-10-27 04:05:13 -0400 | [diff] [blame] | 30 | #include <linux/bug.h> |
Theodore Ts'o | 47def82 | 2010-07-27 11:56:05 -0400 | [diff] [blame] | 31 | #include <linux/module.h> |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 32 | |
Theodore Ts'o | 343d9c2 | 2013-02-08 13:00:22 -0500 | [diff] [blame] | 33 | #include <trace/events/jbd2.h> |
| 34 | |
Adrian Bunk | 7ddae86 | 2006-12-06 20:38:27 -0800 | [diff] [blame] | 35 | static void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh); |
Jan Kara | de1b794 | 2011-06-13 15:38:22 -0400 | [diff] [blame] | 36 | static void __jbd2_journal_unfile_buffer(struct journal_head *jh); |
Adrian Bunk | 7ddae86 | 2006-12-06 20:38:27 -0800 | [diff] [blame] | 37 | |
Yongqiang Yang | 0c2022e | 2012-02-20 17:53:02 -0500 | [diff] [blame] | 38 | static struct kmem_cache *transaction_cache; |
| 39 | int __init jbd2_journal_init_transaction_cache(void) |
| 40 | { |
| 41 | J_ASSERT(!transaction_cache); |
| 42 | transaction_cache = kmem_cache_create("jbd2_transaction_s", |
| 43 | sizeof(transaction_t), |
| 44 | 0, |
| 45 | SLAB_HWCACHE_ALIGN|SLAB_TEMPORARY, |
| 46 | NULL); |
| 47 | if (transaction_cache) |
| 48 | return 0; |
| 49 | return -ENOMEM; |
| 50 | } |
| 51 | |
| 52 | void jbd2_journal_destroy_transaction_cache(void) |
| 53 | { |
| 54 | if (transaction_cache) { |
| 55 | kmem_cache_destroy(transaction_cache); |
| 56 | transaction_cache = NULL; |
| 57 | } |
| 58 | } |
| 59 | |
| 60 | void jbd2_journal_free_transaction(transaction_t *transaction) |
| 61 | { |
| 62 | if (unlikely(ZERO_OR_NULL_PTR(transaction))) |
| 63 | return; |
| 64 | kmem_cache_free(transaction_cache, transaction); |
| 65 | } |
| 66 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 67 | /* |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 68 | * jbd2_get_transaction: obtain a new transaction_t object. |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 69 | * |
| 70 | * Simply allocate and initialise a new transaction. Create it in |
| 71 | * RUNNING state and add it to the current journal (which should not |
| 72 | * have an existing running transaction: we only make a new transaction |
| 73 | * once we have started to commit the old one). |
| 74 | * |
| 75 | * Preconditions: |
| 76 | * The journal MUST be locked. We don't perform atomic mallocs on the |
| 77 | * new transaction and we can't block without protecting against other |
| 78 | * processes trying to touch the journal while it is in transition. |
| 79 | * |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 80 | */ |
| 81 | |
| 82 | static transaction_t * |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 83 | jbd2_get_transaction(journal_t *journal, transaction_t *transaction) |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 84 | { |
| 85 | transaction->t_journal = journal; |
| 86 | transaction->t_state = T_RUNNING; |
Josef Bacik | e07f718 | 2008-11-26 01:14:26 -0500 | [diff] [blame] | 87 | transaction->t_start_time = ktime_get(); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 88 | transaction->t_tid = journal->j_transaction_sequence++; |
| 89 | transaction->t_expires = jiffies + journal->j_commit_interval; |
| 90 | spin_lock_init(&transaction->t_handle_lock); |
Theodore Ts'o | a51dca9 | 2010-08-02 08:43:25 -0400 | [diff] [blame] | 91 | atomic_set(&transaction->t_updates, 0); |
Jan Kara | 8f7d89f | 2013-06-04 12:35:11 -0400 | [diff] [blame] | 92 | atomic_set(&transaction->t_outstanding_credits, |
| 93 | atomic_read(&journal->j_reserved_credits)); |
Theodore Ts'o | 8dd4204 | 2010-08-03 21:38:29 -0400 | [diff] [blame] | 94 | atomic_set(&transaction->t_handle_count, 0); |
Jan Kara | c851ed5 | 2008-07-11 19:27:31 -0400 | [diff] [blame] | 95 | INIT_LIST_HEAD(&transaction->t_inode_list); |
Theodore Ts'o | 3e624fc | 2008-10-16 20:00:24 -0400 | [diff] [blame] | 96 | INIT_LIST_HEAD(&transaction->t_private_list); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 97 | |
| 98 | /* Set up the commit timer for the new transaction. */ |
Andreas Dilger | b1f485f | 2009-08-10 22:51:53 -0400 | [diff] [blame] | 99 | journal->j_commit_timer.expires = round_jiffies_up(transaction->t_expires); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 100 | add_timer(&journal->j_commit_timer); |
| 101 | |
| 102 | J_ASSERT(journal->j_running_transaction == NULL); |
| 103 | journal->j_running_transaction = transaction; |
Johann Lombardi | 8e85fb3 | 2008-01-28 23:58:27 -0500 | [diff] [blame] | 104 | transaction->t_max_wait = 0; |
| 105 | transaction->t_start = jiffies; |
Theodore Ts'o | 9fff24a | 2013-02-06 22:30:23 -0500 | [diff] [blame] | 106 | transaction->t_requested = 0; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 107 | |
| 108 | return transaction; |
| 109 | } |
| 110 | |
| 111 | /* |
| 112 | * Handle management. |
| 113 | * |
| 114 | * A handle_t is an object which represents a single atomic update to a |
| 115 | * filesystem, and which tracks all of the modifications which form part |
| 116 | * of that one update. |
| 117 | */ |
| 118 | |
| 119 | /* |
Tao Ma | 28e35e4 | 2011-05-22 21:45:26 -0400 | [diff] [blame] | 120 | * Update transaction's maximum wait time, if debugging is enabled. |
Theodore Ts'o | 6d0bf00 | 2010-08-09 17:28:38 -0400 | [diff] [blame] | 121 | * |
| 122 | * In order for t_max_wait to be reliable, it must be protected by a |
| 123 | * lock. But doing so will mean that start_this_handle() can not be |
| 124 | * run in parallel on SMP systems, which limits our scalability. So |
| 125 | * unless debugging is enabled, we no longer update t_max_wait, which |
| 126 | * means that maximum wait time reported by the jbd2_run_stats |
| 127 | * tracepoint will always be zero. |
| 128 | */ |
Tao Ma | 28e35e4 | 2011-05-22 21:45:26 -0400 | [diff] [blame] | 129 | static inline void update_t_max_wait(transaction_t *transaction, |
| 130 | unsigned long ts) |
Theodore Ts'o | 6d0bf00 | 2010-08-09 17:28:38 -0400 | [diff] [blame] | 131 | { |
| 132 | #ifdef CONFIG_JBD2_DEBUG |
Theodore Ts'o | 6d0bf00 | 2010-08-09 17:28:38 -0400 | [diff] [blame] | 133 | if (jbd2_journal_enable_debug && |
| 134 | time_after(transaction->t_start, ts)) { |
| 135 | ts = jbd2_time_diff(ts, transaction->t_start); |
| 136 | spin_lock(&transaction->t_handle_lock); |
| 137 | if (ts > transaction->t_max_wait) |
| 138 | transaction->t_max_wait = ts; |
| 139 | spin_unlock(&transaction->t_handle_lock); |
| 140 | } |
| 141 | #endif |
| 142 | } |
| 143 | |
| 144 | /* |
Jan Kara | 8f7d89f | 2013-06-04 12:35:11 -0400 | [diff] [blame] | 145 | * Wait until running transaction passes T_LOCKED state. Also starts the commit |
| 146 | * if needed. The function expects running transaction to exist and releases |
| 147 | * j_state_lock. |
| 148 | */ |
| 149 | static void wait_transaction_locked(journal_t *journal) |
| 150 | __releases(journal->j_state_lock) |
| 151 | { |
| 152 | DEFINE_WAIT(wait); |
| 153 | int need_to_start; |
| 154 | tid_t tid = journal->j_running_transaction->t_tid; |
| 155 | |
| 156 | prepare_to_wait(&journal->j_wait_transaction_locked, &wait, |
| 157 | TASK_UNINTERRUPTIBLE); |
| 158 | need_to_start = !tid_geq(journal->j_commit_request, tid); |
| 159 | read_unlock(&journal->j_state_lock); |
| 160 | if (need_to_start) |
| 161 | jbd2_log_start_commit(journal, tid); |
| 162 | schedule(); |
| 163 | finish_wait(&journal->j_wait_transaction_locked, &wait); |
| 164 | } |
| 165 | |
| 166 | static void sub_reserved_credits(journal_t *journal, int blocks) |
| 167 | { |
| 168 | atomic_sub(blocks, &journal->j_reserved_credits); |
| 169 | wake_up(&journal->j_wait_reserved); |
| 170 | } |
| 171 | |
| 172 | /* |
| 173 | * Wait until we can add credits for handle to the running transaction. Called |
| 174 | * with j_state_lock held for reading. Returns 0 if handle joined the running |
| 175 | * transaction. Returns 1 if we had to wait, j_state_lock is dropped, and |
| 176 | * caller must retry. |
| 177 | */ |
| 178 | static int add_transaction_credits(journal_t *journal, int blocks, |
| 179 | int rsv_blocks) |
| 180 | { |
| 181 | transaction_t *t = journal->j_running_transaction; |
| 182 | int needed; |
| 183 | int total = blocks + rsv_blocks; |
| 184 | |
| 185 | /* |
| 186 | * If the current transaction is locked down for commit, wait |
| 187 | * for the lock to be released. |
| 188 | */ |
| 189 | if (t->t_state == T_LOCKED) { |
| 190 | wait_transaction_locked(journal); |
| 191 | return 1; |
| 192 | } |
| 193 | |
| 194 | /* |
| 195 | * If there is not enough space left in the log to write all |
| 196 | * potential buffers requested by this operation, we need to |
| 197 | * stall pending a log checkpoint to free some more log space. |
| 198 | */ |
| 199 | needed = atomic_add_return(total, &t->t_outstanding_credits); |
| 200 | if (needed > journal->j_max_transaction_buffers) { |
| 201 | /* |
| 202 | * If the current transaction is already too large, |
| 203 | * then start to commit it: we can then go back and |
| 204 | * attach this handle to a new transaction. |
| 205 | */ |
| 206 | atomic_sub(total, &t->t_outstanding_credits); |
Lukas Czerner | 6d3ec14 | 2015-08-04 11:21:52 -0400 | [diff] [blame] | 207 | |
| 208 | /* |
| 209 | * Is the number of reserved credits in the current transaction too |
| 210 | * big to fit this handle? Wait until reserved credits are freed. |
| 211 | */ |
| 212 | if (atomic_read(&journal->j_reserved_credits) + total > |
| 213 | journal->j_max_transaction_buffers) { |
| 214 | read_unlock(&journal->j_state_lock); |
| 215 | wait_event(journal->j_wait_reserved, |
| 216 | atomic_read(&journal->j_reserved_credits) + total <= |
| 217 | journal->j_max_transaction_buffers); |
| 218 | return 1; |
| 219 | } |
| 220 | |
Jan Kara | 8f7d89f | 2013-06-04 12:35:11 -0400 | [diff] [blame] | 221 | wait_transaction_locked(journal); |
| 222 | return 1; |
| 223 | } |
| 224 | |
| 225 | /* |
| 226 | * The commit code assumes that it can get enough log space |
| 227 | * without forcing a checkpoint. This is *critical* for |
| 228 | * correctness: a checkpoint of a buffer which is also |
| 229 | * associated with a committing transaction creates a deadlock, |
| 230 | * so commit simply cannot force through checkpoints. |
| 231 | * |
| 232 | * We must therefore ensure the necessary space in the journal |
| 233 | * *before* starting to dirty potentially checkpointed buffers |
| 234 | * in the new transaction. |
| 235 | */ |
| 236 | if (jbd2_log_space_left(journal) < jbd2_space_needed(journal)) { |
| 237 | atomic_sub(total, &t->t_outstanding_credits); |
| 238 | read_unlock(&journal->j_state_lock); |
| 239 | write_lock(&journal->j_state_lock); |
| 240 | if (jbd2_log_space_left(journal) < jbd2_space_needed(journal)) |
| 241 | __jbd2_log_wait_for_space(journal); |
| 242 | write_unlock(&journal->j_state_lock); |
| 243 | return 1; |
| 244 | } |
| 245 | |
| 246 | /* No reservation? We are done... */ |
| 247 | if (!rsv_blocks) |
| 248 | return 0; |
| 249 | |
| 250 | needed = atomic_add_return(rsv_blocks, &journal->j_reserved_credits); |
| 251 | /* We allow at most half of a transaction to be reserved */ |
| 252 | if (needed > journal->j_max_transaction_buffers / 2) { |
| 253 | sub_reserved_credits(journal, rsv_blocks); |
| 254 | atomic_sub(total, &t->t_outstanding_credits); |
| 255 | read_unlock(&journal->j_state_lock); |
| 256 | wait_event(journal->j_wait_reserved, |
| 257 | atomic_read(&journal->j_reserved_credits) + rsv_blocks |
| 258 | <= journal->j_max_transaction_buffers / 2); |
| 259 | return 1; |
| 260 | } |
| 261 | return 0; |
| 262 | } |
| 263 | |
| 264 | /* |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 265 | * start_this_handle: Given a handle, deal with any locking or stalling |
| 266 | * needed to make sure that there is enough journal space for the handle |
| 267 | * to begin. Attach the handle to a transaction and set up the |
| 268 | * transaction's buffer credits. |
| 269 | */ |
| 270 | |
Theodore Ts'o | 47def82 | 2010-07-27 11:56:05 -0400 | [diff] [blame] | 271 | static int start_this_handle(journal_t *journal, handle_t *handle, |
Dan Carpenter | d2159fb | 2011-09-04 10:20:14 -0400 | [diff] [blame] | 272 | gfp_t gfp_mask) |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 273 | { |
Theodore Ts'o | e447183 | 2011-02-12 08:18:24 -0500 | [diff] [blame] | 274 | transaction_t *transaction, *new_transaction = NULL; |
Jan Kara | 8f7d89f | 2013-06-04 12:35:11 -0400 | [diff] [blame] | 275 | int blocks = handle->h_buffer_credits; |
| 276 | int rsv_blocks = 0; |
Tao Ma | 28e35e4 | 2011-05-22 21:45:26 -0400 | [diff] [blame] | 277 | unsigned long ts = jiffies; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 278 | |
Jan Kara | 8f7d89f | 2013-06-04 12:35:11 -0400 | [diff] [blame] | 279 | if (handle->h_rsv_handle) |
| 280 | rsv_blocks = handle->h_rsv_handle->h_buffer_credits; |
| 281 | |
Lukas Czerner | 6d3ec14 | 2015-08-04 11:21:52 -0400 | [diff] [blame] | 282 | /* |
| 283 | * Limit the number of reserved credits to 1/2 of maximum transaction |
| 284 | * size and limit the number of total credits to not exceed maximum |
| 285 | * transaction size per operation. |
| 286 | */ |
| 287 | if ((rsv_blocks > journal->j_max_transaction_buffers / 2) || |
| 288 | (rsv_blocks + blocks > journal->j_max_transaction_buffers)) { |
| 289 | printk(KERN_ERR "JBD2: %s wants too many credits " |
| 290 | "credits:%d rsv_credits:%d max:%d\n", |
| 291 | current->comm, blocks, rsv_blocks, |
| 292 | journal->j_max_transaction_buffers); |
| 293 | WARN_ON(1); |
| 294 | return -ENOSPC; |
| 295 | } |
| 296 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 297 | alloc_transaction: |
| 298 | if (!journal->j_running_transaction) { |
Michal Hocko | 6ccaf3e | 2015-06-08 10:53:10 -0400 | [diff] [blame] | 299 | /* |
| 300 | * If __GFP_FS is not present, then we may be being called from |
| 301 | * inside the fs writeback layer, so we MUST NOT fail. |
| 302 | */ |
| 303 | if ((gfp_mask & __GFP_FS) == 0) |
| 304 | gfp_mask |= __GFP_NOFAIL; |
Wanlong Gao | b2f4edb | 2012-06-01 00:10:32 -0400 | [diff] [blame] | 305 | new_transaction = kmem_cache_zalloc(transaction_cache, |
| 306 | gfp_mask); |
Michal Hocko | 6ccaf3e | 2015-06-08 10:53:10 -0400 | [diff] [blame] | 307 | if (!new_transaction) |
Theodore Ts'o | 47def82 | 2010-07-27 11:56:05 -0400 | [diff] [blame] | 308 | return -ENOMEM; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 309 | } |
| 310 | |
| 311 | jbd_debug(3, "New handle %p going live.\n", handle); |
| 312 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 313 | /* |
| 314 | * We need to hold j_state_lock until t_updates has been incremented, |
| 315 | * for proper journal barrier handling |
| 316 | */ |
Theodore Ts'o | a931da6 | 2010-08-03 21:35:12 -0400 | [diff] [blame] | 317 | repeat: |
| 318 | read_lock(&journal->j_state_lock); |
Theodore Ts'o | 5c2178e | 2010-10-27 21:30:04 -0400 | [diff] [blame] | 319 | BUG_ON(journal->j_flags & JBD2_UNMOUNT); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 320 | if (is_journal_aborted(journal) || |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 321 | (journal->j_errno != 0 && !(journal->j_flags & JBD2_ACK_ERR))) { |
Theodore Ts'o | a931da6 | 2010-08-03 21:35:12 -0400 | [diff] [blame] | 322 | read_unlock(&journal->j_state_lock); |
Yongqiang Yang | 0c2022e | 2012-02-20 17:53:02 -0500 | [diff] [blame] | 323 | jbd2_journal_free_transaction(new_transaction); |
Theodore Ts'o | 47def82 | 2010-07-27 11:56:05 -0400 | [diff] [blame] | 324 | return -EROFS; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 325 | } |
| 326 | |
Jan Kara | 8f7d89f | 2013-06-04 12:35:11 -0400 | [diff] [blame] | 327 | /* |
| 328 | * Wait on the journal's transaction barrier if necessary. Specifically |
| 329 | * we allow reserved handles to proceed because otherwise commit could |
| 330 | * deadlock on page writeback not being able to complete. |
| 331 | */ |
| 332 | if (!handle->h_reserved && journal->j_barrier_count) { |
Theodore Ts'o | a931da6 | 2010-08-03 21:35:12 -0400 | [diff] [blame] | 333 | read_unlock(&journal->j_state_lock); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 334 | wait_event(journal->j_wait_transaction_locked, |
| 335 | journal->j_barrier_count == 0); |
| 336 | goto repeat; |
| 337 | } |
| 338 | |
| 339 | if (!journal->j_running_transaction) { |
Theodore Ts'o | a931da6 | 2010-08-03 21:35:12 -0400 | [diff] [blame] | 340 | read_unlock(&journal->j_state_lock); |
| 341 | if (!new_transaction) |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 342 | goto alloc_transaction; |
Theodore Ts'o | a931da6 | 2010-08-03 21:35:12 -0400 | [diff] [blame] | 343 | write_lock(&journal->j_state_lock); |
Jan Kara | d7961c7 | 2012-12-21 00:15:51 -0500 | [diff] [blame] | 344 | if (!journal->j_running_transaction && |
Jan Kara | 8f7d89f | 2013-06-04 12:35:11 -0400 | [diff] [blame] | 345 | (handle->h_reserved || !journal->j_barrier_count)) { |
Theodore Ts'o | a931da6 | 2010-08-03 21:35:12 -0400 | [diff] [blame] | 346 | jbd2_get_transaction(journal, new_transaction); |
| 347 | new_transaction = NULL; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 348 | } |
Theodore Ts'o | a931da6 | 2010-08-03 21:35:12 -0400 | [diff] [blame] | 349 | write_unlock(&journal->j_state_lock); |
| 350 | goto repeat; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 351 | } |
| 352 | |
| 353 | transaction = journal->j_running_transaction; |
| 354 | |
Jan Kara | 8f7d89f | 2013-06-04 12:35:11 -0400 | [diff] [blame] | 355 | if (!handle->h_reserved) { |
| 356 | /* We may have dropped j_state_lock - restart in that case */ |
| 357 | if (add_transaction_credits(journal, blocks, rsv_blocks)) |
| 358 | goto repeat; |
| 359 | } else { |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 360 | /* |
Jan Kara | 8f7d89f | 2013-06-04 12:35:11 -0400 | [diff] [blame] | 361 | * We have handle reserved so we are allowed to join T_LOCKED |
| 362 | * transaction and we don't have to check for transaction size |
| 363 | * and journal space. |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 364 | */ |
Jan Kara | 8f7d89f | 2013-06-04 12:35:11 -0400 | [diff] [blame] | 365 | sub_reserved_credits(journal, blocks); |
| 366 | handle->h_reserved = 0; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 367 | } |
| 368 | |
| 369 | /* OK, account for the buffers that this operation expects to |
Theodore Ts'o | 8dd4204 | 2010-08-03 21:38:29 -0400 | [diff] [blame] | 370 | * use and add the handle to the running transaction. |
Theodore Ts'o | 8dd4204 | 2010-08-03 21:38:29 -0400 | [diff] [blame] | 371 | */ |
Tao Ma | 28e35e4 | 2011-05-22 21:45:26 -0400 | [diff] [blame] | 372 | update_t_max_wait(transaction, ts); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 373 | handle->h_transaction = transaction; |
Jan Kara | 8f7d89f | 2013-06-04 12:35:11 -0400 | [diff] [blame] | 374 | handle->h_requested_credits = blocks; |
Theodore Ts'o | 343d9c2 | 2013-02-08 13:00:22 -0500 | [diff] [blame] | 375 | handle->h_start_jiffies = jiffies; |
Theodore Ts'o | a51dca9 | 2010-08-02 08:43:25 -0400 | [diff] [blame] | 376 | atomic_inc(&transaction->t_updates); |
Theodore Ts'o | 8dd4204 | 2010-08-03 21:38:29 -0400 | [diff] [blame] | 377 | atomic_inc(&transaction->t_handle_count); |
Jan Kara | 8f7d89f | 2013-06-04 12:35:11 -0400 | [diff] [blame] | 378 | jbd_debug(4, "Handle %p given %d credits (total %d, free %lu)\n", |
| 379 | handle, blocks, |
Theodore Ts'o | a51dca9 | 2010-08-02 08:43:25 -0400 | [diff] [blame] | 380 | atomic_read(&transaction->t_outstanding_credits), |
Jan Kara | 76c3990 | 2013-06-04 12:12:57 -0400 | [diff] [blame] | 381 | jbd2_log_space_left(journal)); |
Theodore Ts'o | a931da6 | 2010-08-03 21:35:12 -0400 | [diff] [blame] | 382 | read_unlock(&journal->j_state_lock); |
Theodore Ts'o | 41a5b91 | 2013-07-01 08:12:41 -0400 | [diff] [blame] | 383 | current->journal_info = handle; |
Jan Kara | 9599b0e | 2009-08-17 21:23:17 -0400 | [diff] [blame] | 384 | |
| 385 | lock_map_acquire(&handle->h_lockdep_map); |
Yongqiang Yang | 0c2022e | 2012-02-20 17:53:02 -0500 | [diff] [blame] | 386 | jbd2_journal_free_transaction(new_transaction); |
Theodore Ts'o | 47def82 | 2010-07-27 11:56:05 -0400 | [diff] [blame] | 387 | return 0; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 388 | } |
| 389 | |
Mingming Cao | 7b75106 | 2008-01-28 23:58:27 -0500 | [diff] [blame] | 390 | static struct lock_class_key jbd2_handle_key; |
| 391 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 392 | /* Allocate a new handle. This should probably be in a slab... */ |
| 393 | static handle_t *new_handle(int nblocks) |
| 394 | { |
Mingming Cao | af1e76d | 2007-10-16 18:38:25 -0400 | [diff] [blame] | 395 | handle_t *handle = jbd2_alloc_handle(GFP_NOFS); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 396 | if (!handle) |
| 397 | return NULL; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 398 | handle->h_buffer_credits = nblocks; |
| 399 | handle->h_ref = 1; |
| 400 | |
Mingming Cao | 7b75106 | 2008-01-28 23:58:27 -0500 | [diff] [blame] | 401 | lockdep_init_map(&handle->h_lockdep_map, "jbd2_handle", |
| 402 | &jbd2_handle_key, 0); |
| 403 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 404 | return handle; |
| 405 | } |
| 406 | |
| 407 | /** |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 408 | * handle_t *jbd2_journal_start() - Obtain a new handle. |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 409 | * @journal: Journal to start transaction on. |
| 410 | * @nblocks: number of block buffer we might modify |
| 411 | * |
| 412 | * We make sure that the transaction can guarantee at least nblocks of |
| 413 | * modified buffers in the log. We block until the log can guarantee |
Jan Kara | 8f7d89f | 2013-06-04 12:35:11 -0400 | [diff] [blame] | 414 | * that much space. Additionally, if rsv_blocks > 0, we also create another |
| 415 | * handle with rsv_blocks reserved blocks in the journal. This handle is |
| 416 | * is stored in h_rsv_handle. It is not attached to any particular transaction |
| 417 | * and thus doesn't block transaction commit. If the caller uses this reserved |
| 418 | * handle, it has to set h_rsv_handle to NULL as otherwise jbd2_journal_stop() |
| 419 | * on the parent handle will dispose the reserved one. Reserved handle has to |
| 420 | * be converted to a normal handle using jbd2_journal_start_reserved() before |
| 421 | * it can be used. |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 422 | * |
Eryu Guan | c867516 | 2011-05-24 17:09:58 -0400 | [diff] [blame] | 423 | * Return a pointer to a newly allocated handle, or an ERR_PTR() value |
| 424 | * on failure. |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 425 | */ |
Jan Kara | 8f7d89f | 2013-06-04 12:35:11 -0400 | [diff] [blame] | 426 | handle_t *jbd2__journal_start(journal_t *journal, int nblocks, int rsv_blocks, |
| 427 | gfp_t gfp_mask, unsigned int type, |
| 428 | unsigned int line_no) |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 429 | { |
| 430 | handle_t *handle = journal_current_handle(); |
| 431 | int err; |
| 432 | |
| 433 | if (!journal) |
| 434 | return ERR_PTR(-EROFS); |
| 435 | |
| 436 | if (handle) { |
| 437 | J_ASSERT(handle->h_transaction->t_journal == journal); |
| 438 | handle->h_ref++; |
| 439 | return handle; |
| 440 | } |
| 441 | |
| 442 | handle = new_handle(nblocks); |
| 443 | if (!handle) |
| 444 | return ERR_PTR(-ENOMEM); |
Jan Kara | 8f7d89f | 2013-06-04 12:35:11 -0400 | [diff] [blame] | 445 | if (rsv_blocks) { |
| 446 | handle_t *rsv_handle; |
| 447 | |
| 448 | rsv_handle = new_handle(rsv_blocks); |
| 449 | if (!rsv_handle) { |
| 450 | jbd2_free_handle(handle); |
| 451 | return ERR_PTR(-ENOMEM); |
| 452 | } |
| 453 | rsv_handle->h_reserved = 1; |
| 454 | rsv_handle->h_journal = journal; |
| 455 | handle->h_rsv_handle = rsv_handle; |
| 456 | } |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 457 | |
Theodore Ts'o | 47def82 | 2010-07-27 11:56:05 -0400 | [diff] [blame] | 458 | err = start_this_handle(journal, handle, gfp_mask); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 459 | if (err < 0) { |
Jan Kara | 8f7d89f | 2013-06-04 12:35:11 -0400 | [diff] [blame] | 460 | if (handle->h_rsv_handle) |
| 461 | jbd2_free_handle(handle->h_rsv_handle); |
Mingming Cao | af1e76d | 2007-10-16 18:38:25 -0400 | [diff] [blame] | 462 | jbd2_free_handle(handle); |
Dmitry Monakhov | df05c1b8 | 2013-03-02 17:08:46 -0500 | [diff] [blame] | 463 | return ERR_PTR(err); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 464 | } |
Theodore Ts'o | 343d9c2 | 2013-02-08 13:00:22 -0500 | [diff] [blame] | 465 | handle->h_type = type; |
| 466 | handle->h_line_no = line_no; |
| 467 | trace_jbd2_handle_start(journal->j_fs_dev->bd_dev, |
| 468 | handle->h_transaction->t_tid, type, |
| 469 | line_no, nblocks); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 470 | return handle; |
| 471 | } |
Theodore Ts'o | 47def82 | 2010-07-27 11:56:05 -0400 | [diff] [blame] | 472 | EXPORT_SYMBOL(jbd2__journal_start); |
| 473 | |
| 474 | |
| 475 | handle_t *jbd2_journal_start(journal_t *journal, int nblocks) |
| 476 | { |
Jan Kara | 8f7d89f | 2013-06-04 12:35:11 -0400 | [diff] [blame] | 477 | return jbd2__journal_start(journal, nblocks, 0, GFP_NOFS, 0, 0); |
Theodore Ts'o | 47def82 | 2010-07-27 11:56:05 -0400 | [diff] [blame] | 478 | } |
| 479 | EXPORT_SYMBOL(jbd2_journal_start); |
| 480 | |
Jan Kara | 8f7d89f | 2013-06-04 12:35:11 -0400 | [diff] [blame] | 481 | void jbd2_journal_free_reserved(handle_t *handle) |
| 482 | { |
| 483 | journal_t *journal = handle->h_journal; |
| 484 | |
| 485 | WARN_ON(!handle->h_reserved); |
| 486 | sub_reserved_credits(journal, handle->h_buffer_credits); |
| 487 | jbd2_free_handle(handle); |
| 488 | } |
| 489 | EXPORT_SYMBOL(jbd2_journal_free_reserved); |
| 490 | |
| 491 | /** |
| 492 | * int jbd2_journal_start_reserved(handle_t *handle) - start reserved handle |
| 493 | * @handle: handle to start |
| 494 | * |
| 495 | * Start handle that has been previously reserved with jbd2_journal_reserve(). |
| 496 | * This attaches @handle to the running transaction (or creates one if there's |
| 497 | * not transaction running). Unlike jbd2_journal_start() this function cannot |
| 498 | * block on journal commit, checkpointing, or similar stuff. It can block on |
| 499 | * memory allocation or frozen journal though. |
| 500 | * |
| 501 | * Return 0 on success, non-zero on error - handle is freed in that case. |
| 502 | */ |
| 503 | int jbd2_journal_start_reserved(handle_t *handle, unsigned int type, |
| 504 | unsigned int line_no) |
| 505 | { |
| 506 | journal_t *journal = handle->h_journal; |
| 507 | int ret = -EIO; |
| 508 | |
| 509 | if (WARN_ON(!handle->h_reserved)) { |
| 510 | /* Someone passed in normal handle? Just stop it. */ |
| 511 | jbd2_journal_stop(handle); |
| 512 | return ret; |
| 513 | } |
| 514 | /* |
| 515 | * Usefulness of mixing of reserved and unreserved handles is |
| 516 | * questionable. So far nobody seems to need it so just error out. |
| 517 | */ |
| 518 | if (WARN_ON(current->journal_info)) { |
| 519 | jbd2_journal_free_reserved(handle); |
| 520 | return ret; |
| 521 | } |
| 522 | |
| 523 | handle->h_journal = NULL; |
Jan Kara | 8f7d89f | 2013-06-04 12:35:11 -0400 | [diff] [blame] | 524 | /* |
| 525 | * GFP_NOFS is here because callers are likely from writeback or |
| 526 | * similarly constrained call sites |
| 527 | */ |
| 528 | ret = start_this_handle(journal, handle, GFP_NOFS); |
Dan Carpenter | 92e3b40 | 2014-02-17 20:33:01 -0500 | [diff] [blame] | 529 | if (ret < 0) { |
Jan Kara | 8f7d89f | 2013-06-04 12:35:11 -0400 | [diff] [blame] | 530 | jbd2_journal_free_reserved(handle); |
Dan Carpenter | 92e3b40 | 2014-02-17 20:33:01 -0500 | [diff] [blame] | 531 | return ret; |
| 532 | } |
Jan Kara | 8f7d89f | 2013-06-04 12:35:11 -0400 | [diff] [blame] | 533 | handle->h_type = type; |
| 534 | handle->h_line_no = line_no; |
Dan Carpenter | 92e3b40 | 2014-02-17 20:33:01 -0500 | [diff] [blame] | 535 | return 0; |
Jan Kara | 8f7d89f | 2013-06-04 12:35:11 -0400 | [diff] [blame] | 536 | } |
| 537 | EXPORT_SYMBOL(jbd2_journal_start_reserved); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 538 | |
| 539 | /** |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 540 | * int jbd2_journal_extend() - extend buffer credits. |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 541 | * @handle: handle to 'extend' |
| 542 | * @nblocks: nr blocks to try to extend by. |
| 543 | * |
| 544 | * Some transactions, such as large extends and truncates, can be done |
| 545 | * atomically all at once or in several stages. The operation requests |
| 546 | * a credit for a number of buffer modications in advance, but can |
| 547 | * extend its credit if it needs more. |
| 548 | * |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 549 | * jbd2_journal_extend tries to give the running handle more buffer credits. |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 550 | * It does not guarantee that allocation - this is a best-effort only. |
| 551 | * The calling process MUST be able to deal cleanly with a failure to |
| 552 | * extend here. |
| 553 | * |
| 554 | * Return 0 on success, non-zero on failure. |
| 555 | * |
| 556 | * return code < 0 implies an error |
| 557 | * return code > 0 implies normal transaction-full status. |
| 558 | */ |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 559 | int jbd2_journal_extend(handle_t *handle, int nblocks) |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 560 | { |
| 561 | transaction_t *transaction = handle->h_transaction; |
Theodore Ts'o | 41a5b91 | 2013-07-01 08:12:41 -0400 | [diff] [blame] | 562 | journal_t *journal; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 563 | int result; |
| 564 | int wanted; |
| 565 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 566 | if (is_handle_aborted(handle)) |
Theodore Ts'o | 41a5b91 | 2013-07-01 08:12:41 -0400 | [diff] [blame] | 567 | return -EROFS; |
| 568 | journal = transaction->t_journal; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 569 | |
| 570 | result = 1; |
| 571 | |
Theodore Ts'o | a931da6 | 2010-08-03 21:35:12 -0400 | [diff] [blame] | 572 | read_lock(&journal->j_state_lock); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 573 | |
| 574 | /* Don't extend a locked-down transaction! */ |
Theodore Ts'o | 41a5b91 | 2013-07-01 08:12:41 -0400 | [diff] [blame] | 575 | if (transaction->t_state != T_RUNNING) { |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 576 | jbd_debug(3, "denied handle %p %d blocks: " |
| 577 | "transaction not running\n", handle, nblocks); |
| 578 | goto error_out; |
| 579 | } |
| 580 | |
| 581 | spin_lock(&transaction->t_handle_lock); |
Jan Kara | fe1e8db | 2013-06-04 12:22:15 -0400 | [diff] [blame] | 582 | wanted = atomic_add_return(nblocks, |
| 583 | &transaction->t_outstanding_credits); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 584 | |
| 585 | if (wanted > journal->j_max_transaction_buffers) { |
| 586 | jbd_debug(3, "denied handle %p %d blocks: " |
| 587 | "transaction too large\n", handle, nblocks); |
Jan Kara | fe1e8db | 2013-06-04 12:22:15 -0400 | [diff] [blame] | 588 | atomic_sub(nblocks, &transaction->t_outstanding_credits); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 589 | goto unlock; |
| 590 | } |
| 591 | |
Jan Kara | 76c3990 | 2013-06-04 12:12:57 -0400 | [diff] [blame] | 592 | if (wanted + (wanted >> JBD2_CONTROL_BLOCKS_SHIFT) > |
| 593 | jbd2_log_space_left(journal)) { |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 594 | jbd_debug(3, "denied handle %p %d blocks: " |
| 595 | "insufficient log space\n", handle, nblocks); |
Jan Kara | fe1e8db | 2013-06-04 12:22:15 -0400 | [diff] [blame] | 596 | atomic_sub(nblocks, &transaction->t_outstanding_credits); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 597 | goto unlock; |
| 598 | } |
| 599 | |
Theodore Ts'o | 343d9c2 | 2013-02-08 13:00:22 -0500 | [diff] [blame] | 600 | trace_jbd2_handle_extend(journal->j_fs_dev->bd_dev, |
Theodore Ts'o | 41a5b91 | 2013-07-01 08:12:41 -0400 | [diff] [blame] | 601 | transaction->t_tid, |
Theodore Ts'o | 343d9c2 | 2013-02-08 13:00:22 -0500 | [diff] [blame] | 602 | handle->h_type, handle->h_line_no, |
| 603 | handle->h_buffer_credits, |
| 604 | nblocks); |
| 605 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 606 | handle->h_buffer_credits += nblocks; |
Theodore Ts'o | 343d9c2 | 2013-02-08 13:00:22 -0500 | [diff] [blame] | 607 | handle->h_requested_credits += nblocks; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 608 | result = 0; |
| 609 | |
| 610 | jbd_debug(3, "extended handle %p by %d\n", handle, nblocks); |
| 611 | unlock: |
| 612 | spin_unlock(&transaction->t_handle_lock); |
| 613 | error_out: |
Theodore Ts'o | a931da6 | 2010-08-03 21:35:12 -0400 | [diff] [blame] | 614 | read_unlock(&journal->j_state_lock); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 615 | return result; |
| 616 | } |
| 617 | |
| 618 | |
| 619 | /** |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 620 | * int jbd2_journal_restart() - restart a handle . |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 621 | * @handle: handle to restart |
| 622 | * @nblocks: nr credits requested |
| 623 | * |
| 624 | * Restart a handle for a multi-transaction filesystem |
| 625 | * operation. |
| 626 | * |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 627 | * If the jbd2_journal_extend() call above fails to grant new buffer credits |
| 628 | * to a running handle, a call to jbd2_journal_restart will commit the |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 629 | * handle's transaction so far and reattach the handle to a new |
| 630 | * transaction capabable of guaranteeing the requested number of |
Jan Kara | 8f7d89f | 2013-06-04 12:35:11 -0400 | [diff] [blame] | 631 | * credits. We preserve reserved handle if there's any attached to the |
| 632 | * passed in handle. |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 633 | */ |
Dan Carpenter | d2159fb | 2011-09-04 10:20:14 -0400 | [diff] [blame] | 634 | int jbd2__journal_restart(handle_t *handle, int nblocks, gfp_t gfp_mask) |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 635 | { |
| 636 | transaction_t *transaction = handle->h_transaction; |
Theodore Ts'o | 41a5b91 | 2013-07-01 08:12:41 -0400 | [diff] [blame] | 637 | journal_t *journal; |
Theodore Ts'o | e447183 | 2011-02-12 08:18:24 -0500 | [diff] [blame] | 638 | tid_t tid; |
| 639 | int need_to_start, ret; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 640 | |
| 641 | /* If we've had an abort of any type, don't even think about |
| 642 | * actually doing the restart! */ |
| 643 | if (is_handle_aborted(handle)) |
| 644 | return 0; |
Theodore Ts'o | 41a5b91 | 2013-07-01 08:12:41 -0400 | [diff] [blame] | 645 | journal = transaction->t_journal; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 646 | |
| 647 | /* |
| 648 | * First unlink the handle from its current transaction, and start the |
| 649 | * commit on that. |
| 650 | */ |
Theodore Ts'o | a51dca9 | 2010-08-02 08:43:25 -0400 | [diff] [blame] | 651 | J_ASSERT(atomic_read(&transaction->t_updates) > 0); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 652 | J_ASSERT(journal_current_handle() == handle); |
| 653 | |
Theodore Ts'o | a931da6 | 2010-08-03 21:35:12 -0400 | [diff] [blame] | 654 | read_lock(&journal->j_state_lock); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 655 | spin_lock(&transaction->t_handle_lock); |
Theodore Ts'o | a51dca9 | 2010-08-02 08:43:25 -0400 | [diff] [blame] | 656 | atomic_sub(handle->h_buffer_credits, |
| 657 | &transaction->t_outstanding_credits); |
Jan Kara | 8f7d89f | 2013-06-04 12:35:11 -0400 | [diff] [blame] | 658 | if (handle->h_rsv_handle) { |
| 659 | sub_reserved_credits(journal, |
| 660 | handle->h_rsv_handle->h_buffer_credits); |
| 661 | } |
Theodore Ts'o | a51dca9 | 2010-08-02 08:43:25 -0400 | [diff] [blame] | 662 | if (atomic_dec_and_test(&transaction->t_updates)) |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 663 | wake_up(&journal->j_wait_updates); |
Theodore Ts'o | 39c0415 | 2013-07-01 08:12:40 -0400 | [diff] [blame] | 664 | tid = transaction->t_tid; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 665 | spin_unlock(&transaction->t_handle_lock); |
Theodore Ts'o | 41a5b91 | 2013-07-01 08:12:41 -0400 | [diff] [blame] | 666 | handle->h_transaction = NULL; |
| 667 | current->journal_info = NULL; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 668 | |
| 669 | jbd_debug(2, "restarting handle %p\n", handle); |
Theodore Ts'o | e447183 | 2011-02-12 08:18:24 -0500 | [diff] [blame] | 670 | need_to_start = !tid_geq(journal->j_commit_request, tid); |
Theodore Ts'o | a931da6 | 2010-08-03 21:35:12 -0400 | [diff] [blame] | 671 | read_unlock(&journal->j_state_lock); |
Theodore Ts'o | e447183 | 2011-02-12 08:18:24 -0500 | [diff] [blame] | 672 | if (need_to_start) |
| 673 | jbd2_log_start_commit(journal, tid); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 674 | |
Jan Kara | 9599b0e | 2009-08-17 21:23:17 -0400 | [diff] [blame] | 675 | lock_map_release(&handle->h_lockdep_map); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 676 | handle->h_buffer_credits = nblocks; |
Theodore Ts'o | 47def82 | 2010-07-27 11:56:05 -0400 | [diff] [blame] | 677 | ret = start_this_handle(journal, handle, gfp_mask); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 678 | return ret; |
| 679 | } |
Theodore Ts'o | 47def82 | 2010-07-27 11:56:05 -0400 | [diff] [blame] | 680 | EXPORT_SYMBOL(jbd2__journal_restart); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 681 | |
| 682 | |
Theodore Ts'o | 47def82 | 2010-07-27 11:56:05 -0400 | [diff] [blame] | 683 | int jbd2_journal_restart(handle_t *handle, int nblocks) |
| 684 | { |
| 685 | return jbd2__journal_restart(handle, nblocks, GFP_NOFS); |
| 686 | } |
| 687 | EXPORT_SYMBOL(jbd2_journal_restart); |
| 688 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 689 | /** |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 690 | * void jbd2_journal_lock_updates () - establish a transaction barrier. |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 691 | * @journal: Journal to establish a barrier on. |
| 692 | * |
| 693 | * This locks out any further updates from being started, and blocks |
| 694 | * until all existing updates have completed, returning only once the |
| 695 | * journal is in a quiescent state with no updates running. |
| 696 | * |
| 697 | * The journal lock should not be held on entry. |
| 698 | */ |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 699 | void jbd2_journal_lock_updates(journal_t *journal) |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 700 | { |
| 701 | DEFINE_WAIT(wait); |
| 702 | |
Theodore Ts'o | a931da6 | 2010-08-03 21:35:12 -0400 | [diff] [blame] | 703 | write_lock(&journal->j_state_lock); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 704 | ++journal->j_barrier_count; |
| 705 | |
Jan Kara | 8f7d89f | 2013-06-04 12:35:11 -0400 | [diff] [blame] | 706 | /* Wait until there are no reserved handles */ |
| 707 | if (atomic_read(&journal->j_reserved_credits)) { |
| 708 | write_unlock(&journal->j_state_lock); |
| 709 | wait_event(journal->j_wait_reserved, |
| 710 | atomic_read(&journal->j_reserved_credits) == 0); |
| 711 | write_lock(&journal->j_state_lock); |
| 712 | } |
| 713 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 714 | /* Wait until there are no running updates */ |
| 715 | while (1) { |
| 716 | transaction_t *transaction = journal->j_running_transaction; |
| 717 | |
| 718 | if (!transaction) |
| 719 | break; |
| 720 | |
| 721 | spin_lock(&transaction->t_handle_lock); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 722 | prepare_to_wait(&journal->j_wait_updates, &wait, |
| 723 | TASK_UNINTERRUPTIBLE); |
Jan Kara | 9837d8e | 2012-01-04 22:03:11 -0500 | [diff] [blame] | 724 | if (!atomic_read(&transaction->t_updates)) { |
| 725 | spin_unlock(&transaction->t_handle_lock); |
| 726 | finish_wait(&journal->j_wait_updates, &wait); |
| 727 | break; |
| 728 | } |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 729 | spin_unlock(&transaction->t_handle_lock); |
Theodore Ts'o | a931da6 | 2010-08-03 21:35:12 -0400 | [diff] [blame] | 730 | write_unlock(&journal->j_state_lock); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 731 | schedule(); |
| 732 | finish_wait(&journal->j_wait_updates, &wait); |
Theodore Ts'o | a931da6 | 2010-08-03 21:35:12 -0400 | [diff] [blame] | 733 | write_lock(&journal->j_state_lock); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 734 | } |
Theodore Ts'o | a931da6 | 2010-08-03 21:35:12 -0400 | [diff] [blame] | 735 | write_unlock(&journal->j_state_lock); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 736 | |
| 737 | /* |
| 738 | * We have now established a barrier against other normal updates, but |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 739 | * we also need to barrier against other jbd2_journal_lock_updates() calls |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 740 | * to make sure that we serialise special journal-locked operations |
| 741 | * too. |
| 742 | */ |
| 743 | mutex_lock(&journal->j_barrier); |
| 744 | } |
| 745 | |
| 746 | /** |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 747 | * void jbd2_journal_unlock_updates (journal_t* journal) - release barrier |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 748 | * @journal: Journal to release the barrier on. |
| 749 | * |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 750 | * Release a transaction barrier obtained with jbd2_journal_lock_updates(). |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 751 | * |
| 752 | * Should be called without the journal lock held. |
| 753 | */ |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 754 | void jbd2_journal_unlock_updates (journal_t *journal) |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 755 | { |
| 756 | J_ASSERT(journal->j_barrier_count != 0); |
| 757 | |
| 758 | mutex_unlock(&journal->j_barrier); |
Theodore Ts'o | a931da6 | 2010-08-03 21:35:12 -0400 | [diff] [blame] | 759 | write_lock(&journal->j_state_lock); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 760 | --journal->j_barrier_count; |
Theodore Ts'o | a931da6 | 2010-08-03 21:35:12 -0400 | [diff] [blame] | 761 | write_unlock(&journal->j_state_lock); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 762 | wake_up(&journal->j_wait_transaction_locked); |
| 763 | } |
| 764 | |
Jan Kara | f91d1d0 | 2009-07-13 16:16:20 -0400 | [diff] [blame] | 765 | static void warn_dirty_buffer(struct buffer_head *bh) |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 766 | { |
Jan Kara | f91d1d0 | 2009-07-13 16:16:20 -0400 | [diff] [blame] | 767 | char b[BDEVNAME_SIZE]; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 768 | |
Jan Kara | f91d1d0 | 2009-07-13 16:16:20 -0400 | [diff] [blame] | 769 | printk(KERN_WARNING |
Eryu Guan | f2a4452 | 2011-11-01 19:09:18 -0400 | [diff] [blame] | 770 | "JBD2: Spotted dirty metadata buffer (dev = %s, blocknr = %llu). " |
Jan Kara | f91d1d0 | 2009-07-13 16:16:20 -0400 | [diff] [blame] | 771 | "There's a risk of filesystem corruption in case of system " |
| 772 | "crash.\n", |
| 773 | bdevname(bh->b_bdev, b), (unsigned long long)bh->b_blocknr); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 774 | } |
| 775 | |
Jan Kara | ee57aba | 2015-06-08 12:39:07 -0400 | [diff] [blame] | 776 | /* Call t_frozen trigger and copy buffer data into jh->b_frozen_data. */ |
| 777 | static void jbd2_freeze_jh_data(struct journal_head *jh) |
| 778 | { |
| 779 | struct page *page; |
| 780 | int offset; |
| 781 | char *source; |
| 782 | struct buffer_head *bh = jh2bh(jh); |
| 783 | |
| 784 | J_EXPECT_JH(jh, buffer_uptodate(bh), "Possible IO failure.\n"); |
| 785 | page = bh->b_page; |
| 786 | offset = offset_in_page(bh->b_data); |
| 787 | source = kmap_atomic(page); |
| 788 | /* Fire data frozen trigger just before we copy the data */ |
| 789 | jbd2_buffer_frozen_trigger(jh, source + offset, jh->b_triggers); |
| 790 | memcpy(jh->b_frozen_data, source + offset, bh->b_size); |
| 791 | kunmap_atomic(source); |
| 792 | |
| 793 | /* |
| 794 | * Now that the frozen data is saved off, we need to store any matching |
| 795 | * triggers. |
| 796 | */ |
| 797 | jh->b_frozen_triggers = jh->b_triggers; |
| 798 | } |
| 799 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 800 | /* |
| 801 | * If the buffer is already part of the current transaction, then there |
| 802 | * is nothing we need to do. If it is already part of a prior |
| 803 | * transaction which we are still committing to disk, then we need to |
| 804 | * make sure that we do not overwrite the old copy: we do copy-out to |
| 805 | * preserve the copy going to disk. We also account the buffer against |
| 806 | * the handle's metadata buffer credits (unless the buffer is already |
| 807 | * part of the transaction, that is). |
| 808 | * |
| 809 | */ |
| 810 | static int |
| 811 | do_get_write_access(handle_t *handle, struct journal_head *jh, |
| 812 | int force_copy) |
| 813 | { |
| 814 | struct buffer_head *bh; |
Theodore Ts'o | 41a5b91 | 2013-07-01 08:12:41 -0400 | [diff] [blame] | 815 | transaction_t *transaction = handle->h_transaction; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 816 | journal_t *journal; |
| 817 | int error; |
| 818 | char *frozen_buffer = NULL; |
Theodore Ts'o | f783f09 | 2013-04-21 16:47:54 -0400 | [diff] [blame] | 819 | unsigned long start_lock, time_lock; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 820 | |
| 821 | if (is_handle_aborted(handle)) |
| 822 | return -EROFS; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 823 | journal = transaction->t_journal; |
| 824 | |
Theodore Ts'o | cfef2c6 | 2010-12-18 13:07:34 -0500 | [diff] [blame] | 825 | jbd_debug(5, "journal_head %p, force_copy %d\n", jh, force_copy); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 826 | |
| 827 | JBUFFER_TRACE(jh, "entry"); |
| 828 | repeat: |
| 829 | bh = jh2bh(jh); |
| 830 | |
| 831 | /* @@@ Need to check for errors here at some point. */ |
| 832 | |
Theodore Ts'o | f783f09 | 2013-04-21 16:47:54 -0400 | [diff] [blame] | 833 | start_lock = jiffies; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 834 | lock_buffer(bh); |
| 835 | jbd_lock_bh_state(bh); |
| 836 | |
Theodore Ts'o | f783f09 | 2013-04-21 16:47:54 -0400 | [diff] [blame] | 837 | /* If it takes too long to lock the buffer, trace it */ |
| 838 | time_lock = jbd2_time_diff(start_lock, jiffies); |
| 839 | if (time_lock > HZ/10) |
| 840 | trace_jbd2_lock_buffer_stall(bh->b_bdev->bd_dev, |
| 841 | jiffies_to_msecs(time_lock)); |
| 842 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 843 | /* We now hold the buffer lock so it is safe to query the buffer |
| 844 | * state. Is the buffer dirty? |
| 845 | * |
| 846 | * If so, there are two possibilities. The buffer may be |
| 847 | * non-journaled, and undergoing a quite legitimate writeback. |
| 848 | * Otherwise, it is journaled, and we don't expect dirty buffers |
| 849 | * in that state (the buffers should be marked JBD_Dirty |
| 850 | * instead.) So either the IO is being done under our own |
| 851 | * control and this is a bug, or it's a third party IO such as |
| 852 | * dump(8) (which may leave the buffer scheduled for read --- |
| 853 | * ie. locked but not dirty) or tune2fs (which may actually have |
| 854 | * the buffer dirtied, ugh.) */ |
| 855 | |
| 856 | if (buffer_dirty(bh)) { |
| 857 | /* |
| 858 | * First question: is this buffer already part of the current |
| 859 | * transaction or the existing committing transaction? |
| 860 | */ |
| 861 | if (jh->b_transaction) { |
| 862 | J_ASSERT_JH(jh, |
| 863 | jh->b_transaction == transaction || |
| 864 | jh->b_transaction == |
| 865 | journal->j_committing_transaction); |
| 866 | if (jh->b_next_transaction) |
| 867 | J_ASSERT_JH(jh, jh->b_next_transaction == |
| 868 | transaction); |
Jan Kara | f91d1d0 | 2009-07-13 16:16:20 -0400 | [diff] [blame] | 869 | warn_dirty_buffer(bh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 870 | } |
| 871 | /* |
| 872 | * In any case we need to clean the dirty flag and we must |
| 873 | * do it under the buffer lock to be sure we don't race |
| 874 | * with running write-out. |
| 875 | */ |
Jan Kara | f91d1d0 | 2009-07-13 16:16:20 -0400 | [diff] [blame] | 876 | JBUFFER_TRACE(jh, "Journalling dirty buffer"); |
| 877 | clear_buffer_dirty(bh); |
| 878 | set_buffer_jbddirty(bh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 879 | } |
| 880 | |
| 881 | unlock_buffer(bh); |
| 882 | |
| 883 | error = -EROFS; |
| 884 | if (is_handle_aborted(handle)) { |
| 885 | jbd_unlock_bh_state(bh); |
| 886 | goto out; |
| 887 | } |
| 888 | error = 0; |
| 889 | |
| 890 | /* |
| 891 | * The buffer is already part of this transaction if b_transaction or |
| 892 | * b_next_transaction points to it |
| 893 | */ |
| 894 | if (jh->b_transaction == transaction || |
| 895 | jh->b_next_transaction == transaction) |
| 896 | goto done; |
| 897 | |
| 898 | /* |
Josef Bacik | 9fc7c63 | 2008-04-17 10:38:59 -0400 | [diff] [blame] | 899 | * this is the first time this transaction is touching this buffer, |
| 900 | * reset the modified flag |
| 901 | */ |
| 902 | jh->b_modified = 0; |
| 903 | |
| 904 | /* |
Jan Kara | 8b00f40 | 2015-06-08 12:44:21 -0400 | [diff] [blame] | 905 | * If the buffer is not journaled right now, we need to make sure it |
| 906 | * doesn't get written to disk before the caller actually commits the |
| 907 | * new data |
| 908 | */ |
| 909 | if (!jh->b_transaction) { |
| 910 | JBUFFER_TRACE(jh, "no transaction"); |
| 911 | J_ASSERT_JH(jh, !jh->b_next_transaction); |
| 912 | JBUFFER_TRACE(jh, "file as BJ_Reserved"); |
Jan Kara | de92c8c | 2015-06-08 12:46:37 -0400 | [diff] [blame] | 913 | /* |
| 914 | * Make sure all stores to jh (b_modified, b_frozen_data) are |
| 915 | * visible before attaching it to the running transaction. |
| 916 | * Paired with barrier in jbd2_write_access_granted() |
| 917 | */ |
| 918 | smp_wmb(); |
Jan Kara | 8b00f40 | 2015-06-08 12:44:21 -0400 | [diff] [blame] | 919 | spin_lock(&journal->j_list_lock); |
| 920 | __jbd2_journal_file_buffer(jh, transaction, BJ_Reserved); |
| 921 | spin_unlock(&journal->j_list_lock); |
| 922 | goto done; |
| 923 | } |
| 924 | /* |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 925 | * If there is already a copy-out version of this buffer, then we don't |
| 926 | * need to make another one |
| 927 | */ |
| 928 | if (jh->b_frozen_data) { |
| 929 | JBUFFER_TRACE(jh, "has frozen data"); |
| 930 | J_ASSERT_JH(jh, jh->b_next_transaction == NULL); |
Jan Kara | de92c8c | 2015-06-08 12:46:37 -0400 | [diff] [blame] | 931 | goto attach_next; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 932 | } |
| 933 | |
Jan Kara | 8b00f40 | 2015-06-08 12:44:21 -0400 | [diff] [blame] | 934 | JBUFFER_TRACE(jh, "owned by older transaction"); |
| 935 | J_ASSERT_JH(jh, jh->b_next_transaction == NULL); |
| 936 | J_ASSERT_JH(jh, jh->b_transaction == journal->j_committing_transaction); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 937 | |
| 938 | /* |
Jan Kara | 8b00f40 | 2015-06-08 12:44:21 -0400 | [diff] [blame] | 939 | * There is one case we have to be very careful about. If the |
| 940 | * committing transaction is currently writing this buffer out to disk |
| 941 | * and has NOT made a copy-out, then we cannot modify the buffer |
| 942 | * contents at all right now. The essence of copy-out is that it is |
| 943 | * the extra copy, not the primary copy, which gets journaled. If the |
| 944 | * primary copy is already going to disk then we cannot do copy-out |
| 945 | * here. |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 946 | */ |
Jan Kara | 8b00f40 | 2015-06-08 12:44:21 -0400 | [diff] [blame] | 947 | if (buffer_shadow(bh)) { |
| 948 | JBUFFER_TRACE(jh, "on shadow: sleep"); |
| 949 | jbd_unlock_bh_state(bh); |
| 950 | wait_on_bit_io(&bh->b_state, BH_Shadow, TASK_UNINTERRUPTIBLE); |
| 951 | goto repeat; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 952 | } |
| 953 | |
Jan Kara | 8b00f40 | 2015-06-08 12:44:21 -0400 | [diff] [blame] | 954 | /* |
| 955 | * Only do the copy if the currently-owning transaction still needs it. |
| 956 | * If buffer isn't on BJ_Metadata list, the committing transaction is |
| 957 | * past that stage (here we use the fact that BH_Shadow is set under |
| 958 | * bh_state lock together with refiling to BJ_Shadow list and at this |
| 959 | * point we know the buffer doesn't have BH_Shadow set). |
| 960 | * |
| 961 | * Subtle point, though: if this is a get_undo_access, then we will be |
| 962 | * relying on the frozen_data to contain the new value of the |
| 963 | * committed_data record after the transaction, so we HAVE to force the |
| 964 | * frozen_data copy in that case. |
| 965 | */ |
| 966 | if (jh->b_jlist == BJ_Metadata || force_copy) { |
| 967 | JBUFFER_TRACE(jh, "generate frozen data"); |
| 968 | if (!frozen_buffer) { |
| 969 | JBUFFER_TRACE(jh, "allocate memory for buffer"); |
| 970 | jbd_unlock_bh_state(bh); |
| 971 | frozen_buffer = jbd2_alloc(jh2bh(jh)->b_size, GFP_NOFS); |
| 972 | if (!frozen_buffer) { |
| 973 | printk(KERN_ERR "%s: OOM for frozen_buffer\n", |
| 974 | __func__); |
| 975 | JBUFFER_TRACE(jh, "oom!"); |
| 976 | error = -ENOMEM; |
| 977 | goto out; |
| 978 | } |
| 979 | goto repeat; |
| 980 | } |
| 981 | jh->b_frozen_data = frozen_buffer; |
| 982 | frozen_buffer = NULL; |
| 983 | jbd2_freeze_jh_data(jh); |
| 984 | } |
Jan Kara | de92c8c | 2015-06-08 12:46:37 -0400 | [diff] [blame] | 985 | attach_next: |
| 986 | /* |
| 987 | * Make sure all stores to jh (b_modified, b_frozen_data) are visible |
| 988 | * before attaching it to the running transaction. Paired with barrier |
| 989 | * in jbd2_write_access_granted() |
| 990 | */ |
| 991 | smp_wmb(); |
Jan Kara | 8b00f40 | 2015-06-08 12:44:21 -0400 | [diff] [blame] | 992 | jh->b_next_transaction = transaction; |
| 993 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 994 | done: |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 995 | jbd_unlock_bh_state(bh); |
| 996 | |
| 997 | /* |
| 998 | * If we are about to journal a buffer, then any revoke pending on it is |
| 999 | * no longer valid |
| 1000 | */ |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1001 | jbd2_journal_cancel_revoke(handle, jh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1002 | |
| 1003 | out: |
| 1004 | if (unlikely(frozen_buffer)) /* It's usually NULL */ |
Mingming Cao | af1e76d | 2007-10-16 18:38:25 -0400 | [diff] [blame] | 1005 | jbd2_free(frozen_buffer, bh->b_size); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1006 | |
| 1007 | JBUFFER_TRACE(jh, "exit"); |
| 1008 | return error; |
| 1009 | } |
| 1010 | |
Jan Kara | de92c8c | 2015-06-08 12:46:37 -0400 | [diff] [blame] | 1011 | /* Fast check whether buffer is already attached to the required transaction */ |
| 1012 | static bool jbd2_write_access_granted(handle_t *handle, struct buffer_head *bh) |
| 1013 | { |
| 1014 | struct journal_head *jh; |
| 1015 | bool ret = false; |
| 1016 | |
| 1017 | /* Dirty buffers require special handling... */ |
| 1018 | if (buffer_dirty(bh)) |
| 1019 | return false; |
| 1020 | |
| 1021 | /* |
| 1022 | * RCU protects us from dereferencing freed pages. So the checks we do |
| 1023 | * are guaranteed not to oops. However the jh slab object can get freed |
| 1024 | * & reallocated while we work with it. So we have to be careful. When |
| 1025 | * we see jh attached to the running transaction, we know it must stay |
| 1026 | * so until the transaction is committed. Thus jh won't be freed and |
| 1027 | * will be attached to the same bh while we run. However it can |
| 1028 | * happen jh gets freed, reallocated, and attached to the transaction |
| 1029 | * just after we get pointer to it from bh. So we have to be careful |
| 1030 | * and recheck jh still belongs to our bh before we return success. |
| 1031 | */ |
| 1032 | rcu_read_lock(); |
| 1033 | if (!buffer_jbd(bh)) |
| 1034 | goto out; |
| 1035 | /* This should be bh2jh() but that doesn't work with inline functions */ |
| 1036 | jh = READ_ONCE(bh->b_private); |
| 1037 | if (!jh) |
| 1038 | goto out; |
| 1039 | if (jh->b_transaction != handle->h_transaction && |
| 1040 | jh->b_next_transaction != handle->h_transaction) |
| 1041 | goto out; |
| 1042 | /* |
| 1043 | * There are two reasons for the barrier here: |
| 1044 | * 1) Make sure to fetch b_bh after we did previous checks so that we |
| 1045 | * detect when jh went through free, realloc, attach to transaction |
| 1046 | * while we were checking. Paired with implicit barrier in that path. |
| 1047 | * 2) So that access to bh done after jbd2_write_access_granted() |
| 1048 | * doesn't get reordered and see inconsistent state of concurrent |
| 1049 | * do_get_write_access(). |
| 1050 | */ |
| 1051 | smp_mb(); |
| 1052 | if (unlikely(jh->b_bh != bh)) |
| 1053 | goto out; |
| 1054 | ret = true; |
| 1055 | out: |
| 1056 | rcu_read_unlock(); |
| 1057 | return ret; |
| 1058 | } |
| 1059 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1060 | /** |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1061 | * int jbd2_journal_get_write_access() - notify intent to modify a buffer for metadata (not data) update. |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1062 | * @handle: transaction to add buffer modifications to |
| 1063 | * @bh: bh to be used for metadata writes |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1064 | * |
| 1065 | * Returns an error code or 0 on success. |
| 1066 | * |
| 1067 | * In full data journalling mode the buffer may be of type BJ_AsyncData, |
| 1068 | * because we're write()ing a buffer which is also part of a shared mapping. |
| 1069 | */ |
| 1070 | |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1071 | int jbd2_journal_get_write_access(handle_t *handle, struct buffer_head *bh) |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1072 | { |
Jan Kara | de92c8c | 2015-06-08 12:46:37 -0400 | [diff] [blame] | 1073 | struct journal_head *jh; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1074 | int rc; |
| 1075 | |
Jan Kara | de92c8c | 2015-06-08 12:46:37 -0400 | [diff] [blame] | 1076 | if (jbd2_write_access_granted(handle, bh)) |
| 1077 | return 0; |
| 1078 | |
| 1079 | jh = jbd2_journal_add_journal_head(bh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1080 | /* We do not want to get caught playing with fields which the |
| 1081 | * log thread also manipulates. Make sure that the buffer |
| 1082 | * completes any outstanding IO before proceeding. */ |
| 1083 | rc = do_get_write_access(handle, jh, 0); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1084 | jbd2_journal_put_journal_head(jh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1085 | return rc; |
| 1086 | } |
| 1087 | |
| 1088 | |
| 1089 | /* |
| 1090 | * When the user wants to journal a newly created buffer_head |
| 1091 | * (ie. getblk() returned a new buffer and we are going to populate it |
| 1092 | * manually rather than reading off disk), then we need to keep the |
| 1093 | * buffer_head locked until it has been completely filled with new |
| 1094 | * data. In this case, we should be able to make the assertion that |
| 1095 | * the bh is not already part of an existing transaction. |
| 1096 | * |
| 1097 | * The buffer should already be locked by the caller by this point. |
| 1098 | * There is no lock ranking violation: it was a newly created, |
| 1099 | * unlocked buffer beforehand. */ |
| 1100 | |
| 1101 | /** |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1102 | * int jbd2_journal_get_create_access () - notify intent to use newly created bh |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1103 | * @handle: transaction to new buffer to |
| 1104 | * @bh: new buffer. |
| 1105 | * |
| 1106 | * Call this if you create a new bh. |
| 1107 | */ |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1108 | int jbd2_journal_get_create_access(handle_t *handle, struct buffer_head *bh) |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1109 | { |
| 1110 | transaction_t *transaction = handle->h_transaction; |
Theodore Ts'o | 41a5b91 | 2013-07-01 08:12:41 -0400 | [diff] [blame] | 1111 | journal_t *journal; |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1112 | struct journal_head *jh = jbd2_journal_add_journal_head(bh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1113 | int err; |
| 1114 | |
| 1115 | jbd_debug(5, "journal_head %p\n", jh); |
| 1116 | err = -EROFS; |
| 1117 | if (is_handle_aborted(handle)) |
| 1118 | goto out; |
Theodore Ts'o | 41a5b91 | 2013-07-01 08:12:41 -0400 | [diff] [blame] | 1119 | journal = transaction->t_journal; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1120 | err = 0; |
| 1121 | |
| 1122 | JBUFFER_TRACE(jh, "entry"); |
| 1123 | /* |
| 1124 | * The buffer may already belong to this transaction due to pre-zeroing |
| 1125 | * in the filesystem's new_block code. It may also be on the previous, |
| 1126 | * committing transaction's lists, but it HAS to be in Forget state in |
| 1127 | * that case: the transaction must have deleted the buffer for it to be |
| 1128 | * reused here. |
| 1129 | */ |
| 1130 | jbd_lock_bh_state(bh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1131 | J_ASSERT_JH(jh, (jh->b_transaction == transaction || |
| 1132 | jh->b_transaction == NULL || |
| 1133 | (jh->b_transaction == journal->j_committing_transaction && |
| 1134 | jh->b_jlist == BJ_Forget))); |
| 1135 | |
| 1136 | J_ASSERT_JH(jh, jh->b_next_transaction == NULL); |
| 1137 | J_ASSERT_JH(jh, buffer_locked(jh2bh(jh))); |
| 1138 | |
| 1139 | if (jh->b_transaction == NULL) { |
Jan Kara | f91d1d0 | 2009-07-13 16:16:20 -0400 | [diff] [blame] | 1140 | /* |
| 1141 | * Previous jbd2_journal_forget() could have left the buffer |
| 1142 | * with jbddirty bit set because it was being committed. When |
| 1143 | * the commit finished, we've filed the buffer for |
| 1144 | * checkpointing and marked it dirty. Now we are reallocating |
| 1145 | * the buffer so the transaction freeing it must have |
| 1146 | * committed and so it's safe to clear the dirty bit. |
| 1147 | */ |
| 1148 | clear_buffer_dirty(jh2bh(jh)); |
Josef Bacik | 9fc7c63 | 2008-04-17 10:38:59 -0400 | [diff] [blame] | 1149 | /* first access by this transaction */ |
| 1150 | jh->b_modified = 0; |
| 1151 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1152 | JBUFFER_TRACE(jh, "file as BJ_Reserved"); |
Theodore Ts'o | 6e4862a | 2014-03-09 00:46:23 -0500 | [diff] [blame] | 1153 | spin_lock(&journal->j_list_lock); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1154 | __jbd2_journal_file_buffer(jh, transaction, BJ_Reserved); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1155 | } else if (jh->b_transaction == journal->j_committing_transaction) { |
Josef Bacik | 9fc7c63 | 2008-04-17 10:38:59 -0400 | [diff] [blame] | 1156 | /* first access by this transaction */ |
| 1157 | jh->b_modified = 0; |
| 1158 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1159 | JBUFFER_TRACE(jh, "set next transaction"); |
Theodore Ts'o | 6e4862a | 2014-03-09 00:46:23 -0500 | [diff] [blame] | 1160 | spin_lock(&journal->j_list_lock); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1161 | jh->b_next_transaction = transaction; |
| 1162 | } |
| 1163 | spin_unlock(&journal->j_list_lock); |
| 1164 | jbd_unlock_bh_state(bh); |
| 1165 | |
| 1166 | /* |
| 1167 | * akpm: I added this. ext3_alloc_branch can pick up new indirect |
| 1168 | * blocks which contain freed but then revoked metadata. We need |
| 1169 | * to cancel the revoke in case we end up freeing it yet again |
| 1170 | * and the reallocating as data - this would cause a second revoke, |
| 1171 | * which hits an assertion error. |
| 1172 | */ |
| 1173 | JBUFFER_TRACE(jh, "cancelling revoke"); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1174 | jbd2_journal_cancel_revoke(handle, jh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1175 | out: |
Ding Dinghua | 3991b40 | 2011-05-25 17:43:48 -0400 | [diff] [blame] | 1176 | jbd2_journal_put_journal_head(jh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1177 | return err; |
| 1178 | } |
| 1179 | |
| 1180 | /** |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1181 | * int jbd2_journal_get_undo_access() - Notify intent to modify metadata with |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1182 | * non-rewindable consequences |
| 1183 | * @handle: transaction |
| 1184 | * @bh: buffer to undo |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1185 | * |
| 1186 | * Sometimes there is a need to distinguish between metadata which has |
| 1187 | * been committed to disk and that which has not. The ext3fs code uses |
| 1188 | * this for freeing and allocating space, we have to make sure that we |
| 1189 | * do not reuse freed space until the deallocation has been committed, |
| 1190 | * since if we overwrote that space we would make the delete |
| 1191 | * un-rewindable in case of a crash. |
| 1192 | * |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1193 | * To deal with that, jbd2_journal_get_undo_access requests write access to a |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1194 | * buffer for parts of non-rewindable operations such as delete |
| 1195 | * operations on the bitmaps. The journaling code must keep a copy of |
| 1196 | * the buffer's contents prior to the undo_access call until such time |
| 1197 | * as we know that the buffer has definitely been committed to disk. |
| 1198 | * |
| 1199 | * We never need to know which transaction the committed data is part |
| 1200 | * of, buffers touched here are guaranteed to be dirtied later and so |
| 1201 | * will be committed to a new transaction in due course, at which point |
| 1202 | * we can discard the old committed data pointer. |
| 1203 | * |
| 1204 | * Returns error number or 0 on success. |
| 1205 | */ |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1206 | int jbd2_journal_get_undo_access(handle_t *handle, struct buffer_head *bh) |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1207 | { |
| 1208 | int err; |
Jan Kara | de92c8c | 2015-06-08 12:46:37 -0400 | [diff] [blame] | 1209 | struct journal_head *jh; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1210 | char *committed_data = NULL; |
| 1211 | |
| 1212 | JBUFFER_TRACE(jh, "entry"); |
Jan Kara | de92c8c | 2015-06-08 12:46:37 -0400 | [diff] [blame] | 1213 | if (jbd2_write_access_granted(handle, bh)) |
| 1214 | return 0; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1215 | |
Jan Kara | de92c8c | 2015-06-08 12:46:37 -0400 | [diff] [blame] | 1216 | jh = jbd2_journal_add_journal_head(bh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1217 | /* |
| 1218 | * Do this first --- it can drop the journal lock, so we want to |
| 1219 | * make sure that obtaining the committed_data is done |
| 1220 | * atomically wrt. completion of any outstanding commits. |
| 1221 | */ |
| 1222 | err = do_get_write_access(handle, jh, 1); |
| 1223 | if (err) |
| 1224 | goto out; |
| 1225 | |
| 1226 | repeat: |
| 1227 | if (!jh->b_committed_data) { |
Mingming Cao | af1e76d | 2007-10-16 18:38:25 -0400 | [diff] [blame] | 1228 | committed_data = jbd2_alloc(jh2bh(jh)->b_size, GFP_NOFS); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1229 | if (!committed_data) { |
Jan Kara | 7568507 | 2013-12-08 21:13:59 -0500 | [diff] [blame] | 1230 | printk(KERN_ERR "%s: No memory for committed data\n", |
Harvey Harrison | 329d291 | 2008-04-17 10:38:59 -0400 | [diff] [blame] | 1231 | __func__); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1232 | err = -ENOMEM; |
| 1233 | goto out; |
| 1234 | } |
| 1235 | } |
| 1236 | |
| 1237 | jbd_lock_bh_state(bh); |
| 1238 | if (!jh->b_committed_data) { |
| 1239 | /* Copy out the current buffer contents into the |
| 1240 | * preserved, committed copy. */ |
| 1241 | JBUFFER_TRACE(jh, "generate b_committed data"); |
| 1242 | if (!committed_data) { |
| 1243 | jbd_unlock_bh_state(bh); |
| 1244 | goto repeat; |
| 1245 | } |
| 1246 | |
| 1247 | jh->b_committed_data = committed_data; |
| 1248 | committed_data = NULL; |
| 1249 | memcpy(jh->b_committed_data, bh->b_data, bh->b_size); |
| 1250 | } |
| 1251 | jbd_unlock_bh_state(bh); |
| 1252 | out: |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1253 | jbd2_journal_put_journal_head(jh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1254 | if (unlikely(committed_data)) |
Mingming Cao | af1e76d | 2007-10-16 18:38:25 -0400 | [diff] [blame] | 1255 | jbd2_free(committed_data, bh->b_size); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1256 | return err; |
| 1257 | } |
| 1258 | |
| 1259 | /** |
Joel Becker | e06c822 | 2008-09-11 15:35:47 -0700 | [diff] [blame] | 1260 | * void jbd2_journal_set_triggers() - Add triggers for commit writeout |
| 1261 | * @bh: buffer to trigger on |
| 1262 | * @type: struct jbd2_buffer_trigger_type containing the trigger(s). |
| 1263 | * |
| 1264 | * Set any triggers on this journal_head. This is always safe, because |
| 1265 | * triggers for a committing buffer will be saved off, and triggers for |
| 1266 | * a running transaction will match the buffer in that transaction. |
| 1267 | * |
| 1268 | * Call with NULL to clear the triggers. |
| 1269 | */ |
| 1270 | void jbd2_journal_set_triggers(struct buffer_head *bh, |
| 1271 | struct jbd2_buffer_trigger_type *type) |
| 1272 | { |
Jan Kara | ad56eda | 2013-03-11 13:24:56 -0400 | [diff] [blame] | 1273 | struct journal_head *jh = jbd2_journal_grab_journal_head(bh); |
Joel Becker | e06c822 | 2008-09-11 15:35:47 -0700 | [diff] [blame] | 1274 | |
Jan Kara | ad56eda | 2013-03-11 13:24:56 -0400 | [diff] [blame] | 1275 | if (WARN_ON(!jh)) |
| 1276 | return; |
Joel Becker | e06c822 | 2008-09-11 15:35:47 -0700 | [diff] [blame] | 1277 | jh->b_triggers = type; |
Jan Kara | ad56eda | 2013-03-11 13:24:56 -0400 | [diff] [blame] | 1278 | jbd2_journal_put_journal_head(jh); |
Joel Becker | e06c822 | 2008-09-11 15:35:47 -0700 | [diff] [blame] | 1279 | } |
| 1280 | |
Jan Kara | 13ceef0 | 2010-07-14 07:56:33 +0200 | [diff] [blame] | 1281 | void jbd2_buffer_frozen_trigger(struct journal_head *jh, void *mapped_data, |
Joel Becker | e06c822 | 2008-09-11 15:35:47 -0700 | [diff] [blame] | 1282 | struct jbd2_buffer_trigger_type *triggers) |
| 1283 | { |
| 1284 | struct buffer_head *bh = jh2bh(jh); |
| 1285 | |
Jan Kara | 13ceef0 | 2010-07-14 07:56:33 +0200 | [diff] [blame] | 1286 | if (!triggers || !triggers->t_frozen) |
Joel Becker | e06c822 | 2008-09-11 15:35:47 -0700 | [diff] [blame] | 1287 | return; |
| 1288 | |
Jan Kara | 13ceef0 | 2010-07-14 07:56:33 +0200 | [diff] [blame] | 1289 | triggers->t_frozen(triggers, bh, mapped_data, bh->b_size); |
Joel Becker | e06c822 | 2008-09-11 15:35:47 -0700 | [diff] [blame] | 1290 | } |
| 1291 | |
| 1292 | void jbd2_buffer_abort_trigger(struct journal_head *jh, |
| 1293 | struct jbd2_buffer_trigger_type *triggers) |
| 1294 | { |
| 1295 | if (!triggers || !triggers->t_abort) |
| 1296 | return; |
| 1297 | |
| 1298 | triggers->t_abort(triggers, jh2bh(jh)); |
| 1299 | } |
| 1300 | |
Joel Becker | e06c822 | 2008-09-11 15:35:47 -0700 | [diff] [blame] | 1301 | /** |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1302 | * int jbd2_journal_dirty_metadata() - mark a buffer as containing dirty metadata |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1303 | * @handle: transaction to add buffer to. |
| 1304 | * @bh: buffer to mark |
| 1305 | * |
| 1306 | * mark dirty metadata which needs to be journaled as part of the current |
| 1307 | * transaction. |
| 1308 | * |
Theodore Ts'o | 9ea7a0d | 2011-09-04 10:18:14 -0400 | [diff] [blame] | 1309 | * The buffer must have previously had jbd2_journal_get_write_access() |
| 1310 | * called so that it has a valid journal_head attached to the buffer |
| 1311 | * head. |
| 1312 | * |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1313 | * The buffer is placed on the transaction's metadata list and is marked |
| 1314 | * as belonging to the transaction. |
| 1315 | * |
| 1316 | * Returns error number or 0 on success. |
| 1317 | * |
| 1318 | * Special care needs to be taken if the buffer already belongs to the |
| 1319 | * current committing transaction (in which case we should have frozen |
| 1320 | * data present for that commit). In that case, we don't relink the |
| 1321 | * buffer: that only gets done when the old transaction finally |
| 1322 | * completes its commit. |
| 1323 | */ |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1324 | int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh) |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1325 | { |
| 1326 | transaction_t *transaction = handle->h_transaction; |
Theodore Ts'o | 41a5b91 | 2013-07-01 08:12:41 -0400 | [diff] [blame] | 1327 | journal_t *journal; |
Jan Kara | ad56eda | 2013-03-11 13:24:56 -0400 | [diff] [blame] | 1328 | struct journal_head *jh; |
Theodore Ts'o | 9ea7a0d | 2011-09-04 10:18:14 -0400 | [diff] [blame] | 1329 | int ret = 0; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1330 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1331 | if (is_handle_aborted(handle)) |
Theodore Ts'o | 41a5b91 | 2013-07-01 08:12:41 -0400 | [diff] [blame] | 1332 | return -EROFS; |
Jan Kara | 6e06ae8 | 2015-07-12 18:11:30 -0400 | [diff] [blame] | 1333 | if (!buffer_jbd(bh)) { |
Theodore Ts'o | 9ea7a0d | 2011-09-04 10:18:14 -0400 | [diff] [blame] | 1334 | ret = -EUCLEAN; |
| 1335 | goto out; |
| 1336 | } |
Jan Kara | 6e06ae8 | 2015-07-12 18:11:30 -0400 | [diff] [blame] | 1337 | /* |
| 1338 | * We don't grab jh reference here since the buffer must be part |
| 1339 | * of the running transaction. |
| 1340 | */ |
| 1341 | jh = bh2jh(bh); |
| 1342 | /* |
| 1343 | * This and the following assertions are unreliable since we may see jh |
| 1344 | * in inconsistent state unless we grab bh_state lock. But this is |
| 1345 | * crucial to catch bugs so let's do a reliable check until the |
| 1346 | * lockless handling is fully proven. |
| 1347 | */ |
| 1348 | if (jh->b_transaction != transaction && |
| 1349 | jh->b_next_transaction != transaction) { |
| 1350 | jbd_lock_bh_state(bh); |
| 1351 | J_ASSERT_JH(jh, jh->b_transaction == transaction || |
| 1352 | jh->b_next_transaction == transaction); |
| 1353 | jbd_unlock_bh_state(bh); |
| 1354 | } |
| 1355 | if (jh->b_modified == 1) { |
| 1356 | /* If it's in our transaction it must be in BJ_Metadata list. */ |
| 1357 | if (jh->b_transaction == transaction && |
| 1358 | jh->b_jlist != BJ_Metadata) { |
| 1359 | jbd_lock_bh_state(bh); |
| 1360 | J_ASSERT_JH(jh, jh->b_transaction != transaction || |
| 1361 | jh->b_jlist == BJ_Metadata); |
| 1362 | jbd_unlock_bh_state(bh); |
| 1363 | } |
| 1364 | goto out; |
| 1365 | } |
| 1366 | |
| 1367 | journal = transaction->t_journal; |
Jan Kara | ad56eda | 2013-03-11 13:24:56 -0400 | [diff] [blame] | 1368 | jbd_debug(5, "journal_head %p\n", jh); |
| 1369 | JBUFFER_TRACE(jh, "entry"); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1370 | |
| 1371 | jbd_lock_bh_state(bh); |
| 1372 | |
| 1373 | if (jh->b_modified == 0) { |
| 1374 | /* |
| 1375 | * This buffer's got modified and becoming part |
| 1376 | * of the transaction. This needs to be done |
| 1377 | * once a transaction -bzzz |
| 1378 | */ |
| 1379 | jh->b_modified = 1; |
Theodore Ts'o | f6c07ca | 2013-12-08 21:12:59 -0500 | [diff] [blame] | 1380 | if (handle->h_buffer_credits <= 0) { |
| 1381 | ret = -ENOSPC; |
| 1382 | goto out_unlock_bh; |
| 1383 | } |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1384 | handle->h_buffer_credits--; |
| 1385 | } |
| 1386 | |
| 1387 | /* |
| 1388 | * fastpath, to avoid expensive locking. If this buffer is already |
| 1389 | * on the running transaction's metadata list there is nothing to do. |
| 1390 | * Nobody can take it off again because there is a handle open. |
| 1391 | * I _think_ we're OK here with SMP barriers - a mistaken decision will |
| 1392 | * result in this test being false, so we go in and take the locks. |
| 1393 | */ |
| 1394 | if (jh->b_transaction == transaction && jh->b_jlist == BJ_Metadata) { |
| 1395 | JBUFFER_TRACE(jh, "fastpath"); |
Theodore Ts'o | 9ea7a0d | 2011-09-04 10:18:14 -0400 | [diff] [blame] | 1396 | if (unlikely(jh->b_transaction != |
| 1397 | journal->j_running_transaction)) { |
Dmitry Monakhov | a67c848 | 2013-12-08 21:14:59 -0500 | [diff] [blame] | 1398 | printk(KERN_ERR "JBD2: %s: " |
Theodore Ts'o | 9ea7a0d | 2011-09-04 10:18:14 -0400 | [diff] [blame] | 1399 | "jh->b_transaction (%llu, %p, %u) != " |
Theodore Ts'o | 66a4cb1 | 2014-03-12 16:38:03 -0400 | [diff] [blame] | 1400 | "journal->j_running_transaction (%p, %u)\n", |
Theodore Ts'o | 9ea7a0d | 2011-09-04 10:18:14 -0400 | [diff] [blame] | 1401 | journal->j_devname, |
| 1402 | (unsigned long long) bh->b_blocknr, |
| 1403 | jh->b_transaction, |
| 1404 | jh->b_transaction ? jh->b_transaction->t_tid : 0, |
| 1405 | journal->j_running_transaction, |
| 1406 | journal->j_running_transaction ? |
| 1407 | journal->j_running_transaction->t_tid : 0); |
| 1408 | ret = -EINVAL; |
| 1409 | } |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1410 | goto out_unlock_bh; |
| 1411 | } |
| 1412 | |
| 1413 | set_buffer_jbddirty(bh); |
| 1414 | |
| 1415 | /* |
| 1416 | * Metadata already on the current transaction list doesn't |
| 1417 | * need to be filed. Metadata on another transaction's list must |
| 1418 | * be committing, and will be refiled once the commit completes: |
| 1419 | * leave it alone for now. |
| 1420 | */ |
| 1421 | if (jh->b_transaction != transaction) { |
| 1422 | JBUFFER_TRACE(jh, "already on other transaction"); |
Theodore Ts'o | 66a4cb1 | 2014-03-12 16:38:03 -0400 | [diff] [blame] | 1423 | if (unlikely(((jh->b_transaction != |
| 1424 | journal->j_committing_transaction)) || |
| 1425 | (jh->b_next_transaction != transaction))) { |
| 1426 | printk(KERN_ERR "jbd2_journal_dirty_metadata: %s: " |
| 1427 | "bad jh for block %llu: " |
| 1428 | "transaction (%p, %u), " |
| 1429 | "jh->b_transaction (%p, %u), " |
| 1430 | "jh->b_next_transaction (%p, %u), jlist %u\n", |
Theodore Ts'o | 9ea7a0d | 2011-09-04 10:18:14 -0400 | [diff] [blame] | 1431 | journal->j_devname, |
| 1432 | (unsigned long long) bh->b_blocknr, |
Theodore Ts'o | 66a4cb1 | 2014-03-12 16:38:03 -0400 | [diff] [blame] | 1433 | transaction, transaction->t_tid, |
Theodore Ts'o | 9ea7a0d | 2011-09-04 10:18:14 -0400 | [diff] [blame] | 1434 | jh->b_transaction, |
Theodore Ts'o | 66a4cb1 | 2014-03-12 16:38:03 -0400 | [diff] [blame] | 1435 | jh->b_transaction ? |
| 1436 | jh->b_transaction->t_tid : 0, |
Theodore Ts'o | 9ea7a0d | 2011-09-04 10:18:14 -0400 | [diff] [blame] | 1437 | jh->b_next_transaction, |
| 1438 | jh->b_next_transaction ? |
| 1439 | jh->b_next_transaction->t_tid : 0, |
Theodore Ts'o | 66a4cb1 | 2014-03-12 16:38:03 -0400 | [diff] [blame] | 1440 | jh->b_jlist); |
| 1441 | WARN_ON(1); |
Theodore Ts'o | 9ea7a0d | 2011-09-04 10:18:14 -0400 | [diff] [blame] | 1442 | ret = -EINVAL; |
| 1443 | } |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1444 | /* And this case is illegal: we can't reuse another |
| 1445 | * transaction's data buffer, ever. */ |
| 1446 | goto out_unlock_bh; |
| 1447 | } |
| 1448 | |
| 1449 | /* That test should have eliminated the following case: */ |
Mingming Cao | 4019191 | 2008-01-28 23:58:27 -0500 | [diff] [blame] | 1450 | J_ASSERT_JH(jh, jh->b_frozen_data == NULL); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1451 | |
| 1452 | JBUFFER_TRACE(jh, "file as BJ_Metadata"); |
| 1453 | spin_lock(&journal->j_list_lock); |
Theodore Ts'o | 41a5b91 | 2013-07-01 08:12:41 -0400 | [diff] [blame] | 1454 | __jbd2_journal_file_buffer(jh, transaction, BJ_Metadata); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1455 | spin_unlock(&journal->j_list_lock); |
| 1456 | out_unlock_bh: |
| 1457 | jbd_unlock_bh_state(bh); |
| 1458 | out: |
| 1459 | JBUFFER_TRACE(jh, "exit"); |
Theodore Ts'o | 9ea7a0d | 2011-09-04 10:18:14 -0400 | [diff] [blame] | 1460 | return ret; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1461 | } |
| 1462 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1463 | /** |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1464 | * void jbd2_journal_forget() - bforget() for potentially-journaled buffers. |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1465 | * @handle: transaction handle |
| 1466 | * @bh: bh to 'forget' |
| 1467 | * |
| 1468 | * We can only do the bforget if there are no commits pending against the |
| 1469 | * buffer. If the buffer is dirty in the current running transaction we |
| 1470 | * can safely unlink it. |
| 1471 | * |
| 1472 | * bh may not be a journalled buffer at all - it may be a non-JBD |
| 1473 | * buffer which came off the hashtable. Check for this. |
| 1474 | * |
| 1475 | * Decrements bh->b_count by one. |
| 1476 | * |
| 1477 | * Allow this call even if the handle has aborted --- it may be part of |
| 1478 | * the caller's cleanup after an abort. |
| 1479 | */ |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1480 | int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh) |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1481 | { |
| 1482 | transaction_t *transaction = handle->h_transaction; |
Theodore Ts'o | 41a5b91 | 2013-07-01 08:12:41 -0400 | [diff] [blame] | 1483 | journal_t *journal; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1484 | struct journal_head *jh; |
| 1485 | int drop_reserve = 0; |
| 1486 | int err = 0; |
Josef Bacik | 1dfc322 | 2008-04-17 10:38:59 -0400 | [diff] [blame] | 1487 | int was_modified = 0; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1488 | |
Theodore Ts'o | 41a5b91 | 2013-07-01 08:12:41 -0400 | [diff] [blame] | 1489 | if (is_handle_aborted(handle)) |
| 1490 | return -EROFS; |
| 1491 | journal = transaction->t_journal; |
| 1492 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1493 | BUFFER_TRACE(bh, "entry"); |
| 1494 | |
| 1495 | jbd_lock_bh_state(bh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1496 | |
| 1497 | if (!buffer_jbd(bh)) |
| 1498 | goto not_jbd; |
| 1499 | jh = bh2jh(bh); |
| 1500 | |
| 1501 | /* Critical error: attempting to delete a bitmap buffer, maybe? |
| 1502 | * Don't do any jbd operations, and return an error. */ |
| 1503 | if (!J_EXPECT_JH(jh, !jh->b_committed_data, |
| 1504 | "inconsistent data on disk")) { |
| 1505 | err = -EIO; |
| 1506 | goto not_jbd; |
| 1507 | } |
| 1508 | |
Adam Buchbinder | 48fc7f7 | 2012-09-19 21:48:00 -0400 | [diff] [blame] | 1509 | /* keep track of whether or not this transaction modified us */ |
Josef Bacik | 1dfc322 | 2008-04-17 10:38:59 -0400 | [diff] [blame] | 1510 | was_modified = jh->b_modified; |
| 1511 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1512 | /* |
| 1513 | * The buffer's going from the transaction, we must drop |
| 1514 | * all references -bzzz |
| 1515 | */ |
| 1516 | jh->b_modified = 0; |
| 1517 | |
Theodore Ts'o | 41a5b91 | 2013-07-01 08:12:41 -0400 | [diff] [blame] | 1518 | if (jh->b_transaction == transaction) { |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1519 | J_ASSERT_JH(jh, !jh->b_frozen_data); |
| 1520 | |
| 1521 | /* If we are forgetting a buffer which is already part |
| 1522 | * of this transaction, then we can just drop it from |
| 1523 | * the transaction immediately. */ |
| 1524 | clear_buffer_dirty(bh); |
| 1525 | clear_buffer_jbddirty(bh); |
| 1526 | |
| 1527 | JBUFFER_TRACE(jh, "belongs to current transaction: unfile"); |
| 1528 | |
Josef Bacik | 1dfc322 | 2008-04-17 10:38:59 -0400 | [diff] [blame] | 1529 | /* |
| 1530 | * we only want to drop a reference if this transaction |
| 1531 | * modified the buffer |
| 1532 | */ |
| 1533 | if (was_modified) |
| 1534 | drop_reserve = 1; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1535 | |
| 1536 | /* |
| 1537 | * We are no longer going to journal this buffer. |
| 1538 | * However, the commit of this transaction is still |
| 1539 | * important to the buffer: the delete that we are now |
| 1540 | * processing might obsolete an old log entry, so by |
| 1541 | * committing, we can satisfy the buffer's checkpoint. |
| 1542 | * |
| 1543 | * So, if we have a checkpoint on the buffer, we should |
| 1544 | * now refile the buffer on our BJ_Forget list so that |
| 1545 | * we know to remove the checkpoint after we commit. |
| 1546 | */ |
| 1547 | |
Theodore Ts'o | 0bfea81 | 2014-03-09 00:56:58 -0500 | [diff] [blame] | 1548 | spin_lock(&journal->j_list_lock); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1549 | if (jh->b_cp_transaction) { |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1550 | __jbd2_journal_temp_unlink_buffer(jh); |
| 1551 | __jbd2_journal_file_buffer(jh, transaction, BJ_Forget); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1552 | } else { |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1553 | __jbd2_journal_unfile_buffer(jh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1554 | if (!buffer_jbd(bh)) { |
| 1555 | spin_unlock(&journal->j_list_lock); |
| 1556 | jbd_unlock_bh_state(bh); |
| 1557 | __bforget(bh); |
| 1558 | goto drop; |
| 1559 | } |
| 1560 | } |
Theodore Ts'o | 0bfea81 | 2014-03-09 00:56:58 -0500 | [diff] [blame] | 1561 | spin_unlock(&journal->j_list_lock); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1562 | } else if (jh->b_transaction) { |
| 1563 | J_ASSERT_JH(jh, (jh->b_transaction == |
| 1564 | journal->j_committing_transaction)); |
| 1565 | /* However, if the buffer is still owned by a prior |
| 1566 | * (committing) transaction, we can't drop it yet... */ |
| 1567 | JBUFFER_TRACE(jh, "belongs to older transaction"); |
| 1568 | /* ... but we CAN drop it from the new transaction if we |
| 1569 | * have also modified it since the original commit. */ |
| 1570 | |
| 1571 | if (jh->b_next_transaction) { |
| 1572 | J_ASSERT(jh->b_next_transaction == transaction); |
Theodore Ts'o | 0bfea81 | 2014-03-09 00:56:58 -0500 | [diff] [blame] | 1573 | spin_lock(&journal->j_list_lock); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1574 | jh->b_next_transaction = NULL; |
Theodore Ts'o | 0bfea81 | 2014-03-09 00:56:58 -0500 | [diff] [blame] | 1575 | spin_unlock(&journal->j_list_lock); |
Josef Bacik | 1dfc322 | 2008-04-17 10:38:59 -0400 | [diff] [blame] | 1576 | |
| 1577 | /* |
| 1578 | * only drop a reference if this transaction modified |
| 1579 | * the buffer |
| 1580 | */ |
| 1581 | if (was_modified) |
| 1582 | drop_reserve = 1; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1583 | } |
| 1584 | } |
| 1585 | |
| 1586 | not_jbd: |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1587 | jbd_unlock_bh_state(bh); |
| 1588 | __brelse(bh); |
| 1589 | drop: |
| 1590 | if (drop_reserve) { |
| 1591 | /* no need to reserve log space for this block -bzzz */ |
| 1592 | handle->h_buffer_credits++; |
| 1593 | } |
| 1594 | return err; |
| 1595 | } |
| 1596 | |
| 1597 | /** |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1598 | * int jbd2_journal_stop() - complete a transaction |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1599 | * @handle: tranaction to complete. |
| 1600 | * |
| 1601 | * All done for a particular handle. |
| 1602 | * |
| 1603 | * There is not much action needed here. We just return any remaining |
| 1604 | * buffer credits to the transaction and remove the handle. The only |
| 1605 | * complication is that we need to start a commit operation if the |
| 1606 | * filesystem is marked for synchronous update. |
| 1607 | * |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1608 | * jbd2_journal_stop itself will not usually return an error, but it may |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1609 | * do so in unusual circumstances. In particular, expect it to |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1610 | * return -EIO if a jbd2_journal_abort has been executed since the |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1611 | * transaction began. |
| 1612 | */ |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1613 | int jbd2_journal_stop(handle_t *handle) |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1614 | { |
| 1615 | transaction_t *transaction = handle->h_transaction; |
Theodore Ts'o | 41a5b91 | 2013-07-01 08:12:41 -0400 | [diff] [blame] | 1616 | journal_t *journal; |
| 1617 | int err = 0, wait_for_commit = 0; |
Theodore Ts'o | a51dca9 | 2010-08-02 08:43:25 -0400 | [diff] [blame] | 1618 | tid_t tid; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1619 | pid_t pid; |
| 1620 | |
Lukas Czerner | 9d50659 | 2015-05-14 18:55:18 -0400 | [diff] [blame] | 1621 | if (!transaction) { |
| 1622 | /* |
| 1623 | * Handle is already detached from the transaction so |
| 1624 | * there is nothing to do other than decrease a refcount, |
| 1625 | * or free the handle if refcount drops to zero |
| 1626 | */ |
| 1627 | if (--handle->h_ref > 0) { |
| 1628 | jbd_debug(4, "h_ref %d -> %d\n", handle->h_ref + 1, |
| 1629 | handle->h_ref); |
| 1630 | return err; |
| 1631 | } else { |
| 1632 | if (handle->h_rsv_handle) |
| 1633 | jbd2_free_handle(handle->h_rsv_handle); |
| 1634 | goto free_and_exit; |
| 1635 | } |
| 1636 | } |
Theodore Ts'o | 41a5b91 | 2013-07-01 08:12:41 -0400 | [diff] [blame] | 1637 | journal = transaction->t_journal; |
| 1638 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1639 | J_ASSERT(journal_current_handle() == handle); |
| 1640 | |
| 1641 | if (is_handle_aborted(handle)) |
| 1642 | err = -EIO; |
Theodore Ts'o | 41a5b91 | 2013-07-01 08:12:41 -0400 | [diff] [blame] | 1643 | else |
Theodore Ts'o | a51dca9 | 2010-08-02 08:43:25 -0400 | [diff] [blame] | 1644 | J_ASSERT(atomic_read(&transaction->t_updates) > 0); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1645 | |
| 1646 | if (--handle->h_ref > 0) { |
| 1647 | jbd_debug(4, "h_ref %d -> %d\n", handle->h_ref + 1, |
| 1648 | handle->h_ref); |
| 1649 | return err; |
| 1650 | } |
| 1651 | |
| 1652 | jbd_debug(4, "Handle %p going down\n", handle); |
Theodore Ts'o | 343d9c2 | 2013-02-08 13:00:22 -0500 | [diff] [blame] | 1653 | trace_jbd2_handle_stats(journal->j_fs_dev->bd_dev, |
Theodore Ts'o | 41a5b91 | 2013-07-01 08:12:41 -0400 | [diff] [blame] | 1654 | transaction->t_tid, |
Theodore Ts'o | 343d9c2 | 2013-02-08 13:00:22 -0500 | [diff] [blame] | 1655 | handle->h_type, handle->h_line_no, |
| 1656 | jiffies - handle->h_start_jiffies, |
| 1657 | handle->h_sync, handle->h_requested_credits, |
| 1658 | (handle->h_requested_credits - |
| 1659 | handle->h_buffer_credits)); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1660 | |
| 1661 | /* |
| 1662 | * Implement synchronous transaction batching. If the handle |
| 1663 | * was synchronous, don't force a commit immediately. Let's |
Josef Bacik | e07f718 | 2008-11-26 01:14:26 -0500 | [diff] [blame] | 1664 | * yield and let another thread piggyback onto this |
| 1665 | * transaction. Keep doing that while new threads continue to |
| 1666 | * arrive. It doesn't cost much - we're about to run a commit |
| 1667 | * and sleep on IO anyway. Speeds up many-threaded, many-dir |
| 1668 | * operations by 30x or more... |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1669 | * |
Josef Bacik | e07f718 | 2008-11-26 01:14:26 -0500 | [diff] [blame] | 1670 | * We try and optimize the sleep time against what the |
| 1671 | * underlying disk can do, instead of having a static sleep |
| 1672 | * time. This is useful for the case where our storage is so |
| 1673 | * fast that it is more optimal to go ahead and force a flush |
| 1674 | * and wait for the transaction to be committed than it is to |
| 1675 | * wait for an arbitrary amount of time for new writers to |
| 1676 | * join the transaction. We achieve this by measuring how |
| 1677 | * long it takes to commit a transaction, and compare it with |
| 1678 | * how long this transaction has been running, and if run time |
| 1679 | * < commit time then we sleep for the delta and commit. This |
| 1680 | * greatly helps super fast disks that would see slowdowns as |
| 1681 | * more threads started doing fsyncs. |
| 1682 | * |
| 1683 | * But don't do this if this process was the most recent one |
| 1684 | * to perform a synchronous write. We do this to detect the |
| 1685 | * case where a single process is doing a stream of sync |
| 1686 | * writes. No point in waiting for joiners in that case. |
Eric Sandeen | 5dd2142 | 2014-07-05 19:18:22 -0400 | [diff] [blame] | 1687 | * |
| 1688 | * Setting max_batch_time to 0 disables this completely. |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1689 | */ |
| 1690 | pid = current->pid; |
Eric Sandeen | 5dd2142 | 2014-07-05 19:18:22 -0400 | [diff] [blame] | 1691 | if (handle->h_sync && journal->j_last_sync_writer != pid && |
| 1692 | journal->j_max_batch_time) { |
Josef Bacik | e07f718 | 2008-11-26 01:14:26 -0500 | [diff] [blame] | 1693 | u64 commit_time, trans_time; |
| 1694 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1695 | journal->j_last_sync_writer = pid; |
Josef Bacik | e07f718 | 2008-11-26 01:14:26 -0500 | [diff] [blame] | 1696 | |
Theodore Ts'o | a931da6 | 2010-08-03 21:35:12 -0400 | [diff] [blame] | 1697 | read_lock(&journal->j_state_lock); |
Josef Bacik | e07f718 | 2008-11-26 01:14:26 -0500 | [diff] [blame] | 1698 | commit_time = journal->j_average_commit_time; |
Theodore Ts'o | a931da6 | 2010-08-03 21:35:12 -0400 | [diff] [blame] | 1699 | read_unlock(&journal->j_state_lock); |
Josef Bacik | e07f718 | 2008-11-26 01:14:26 -0500 | [diff] [blame] | 1700 | |
| 1701 | trans_time = ktime_to_ns(ktime_sub(ktime_get(), |
| 1702 | transaction->t_start_time)); |
| 1703 | |
Theodore Ts'o | 3077384 | 2009-01-03 20:27:38 -0500 | [diff] [blame] | 1704 | commit_time = max_t(u64, commit_time, |
| 1705 | 1000*journal->j_min_batch_time); |
Josef Bacik | e07f718 | 2008-11-26 01:14:26 -0500 | [diff] [blame] | 1706 | commit_time = min_t(u64, commit_time, |
Theodore Ts'o | 3077384 | 2009-01-03 20:27:38 -0500 | [diff] [blame] | 1707 | 1000*journal->j_max_batch_time); |
Josef Bacik | e07f718 | 2008-11-26 01:14:26 -0500 | [diff] [blame] | 1708 | |
| 1709 | if (trans_time < commit_time) { |
| 1710 | ktime_t expires = ktime_add_ns(ktime_get(), |
| 1711 | commit_time); |
| 1712 | set_current_state(TASK_UNINTERRUPTIBLE); |
| 1713 | schedule_hrtimeout(&expires, HRTIMER_MODE_ABS); |
| 1714 | } |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1715 | } |
| 1716 | |
Theodore Ts'o | 7058548 | 2009-03-25 23:35:46 -0400 | [diff] [blame] | 1717 | if (handle->h_sync) |
| 1718 | transaction->t_synchronous_commit = 1; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1719 | current->journal_info = NULL; |
Theodore Ts'o | a51dca9 | 2010-08-02 08:43:25 -0400 | [diff] [blame] | 1720 | atomic_sub(handle->h_buffer_credits, |
| 1721 | &transaction->t_outstanding_credits); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1722 | |
| 1723 | /* |
| 1724 | * If the handle is marked SYNC, we need to set another commit |
| 1725 | * going! We also want to force a commit if the current |
| 1726 | * transaction is occupying too much of the log, or if the |
| 1727 | * transaction is too old now. |
| 1728 | */ |
| 1729 | if (handle->h_sync || |
Theodore Ts'o | a51dca9 | 2010-08-02 08:43:25 -0400 | [diff] [blame] | 1730 | (atomic_read(&transaction->t_outstanding_credits) > |
| 1731 | journal->j_max_transaction_buffers) || |
| 1732 | time_after_eq(jiffies, transaction->t_expires)) { |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1733 | /* Do this even for aborted journals: an abort still |
| 1734 | * completes the commit thread, it just doesn't write |
| 1735 | * anything to disk. */ |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1736 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1737 | jbd_debug(2, "transaction too old, requesting commit for " |
| 1738 | "handle %p\n", handle); |
| 1739 | /* This is non-blocking */ |
Theodore Ts'o | c35a56a | 2010-05-16 05:00:00 -0400 | [diff] [blame] | 1740 | jbd2_log_start_commit(journal, transaction->t_tid); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1741 | |
| 1742 | /* |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1743 | * Special case: JBD2_SYNC synchronous updates require us |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1744 | * to wait for the commit to complete. |
| 1745 | */ |
| 1746 | if (handle->h_sync && !(current->flags & PF_MEMALLOC)) |
Theodore Ts'o | a51dca9 | 2010-08-02 08:43:25 -0400 | [diff] [blame] | 1747 | wait_for_commit = 1; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1748 | } |
| 1749 | |
Theodore Ts'o | a51dca9 | 2010-08-02 08:43:25 -0400 | [diff] [blame] | 1750 | /* |
| 1751 | * Once we drop t_updates, if it goes to zero the transaction |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 1752 | * could start committing on us and eventually disappear. So |
Theodore Ts'o | a51dca9 | 2010-08-02 08:43:25 -0400 | [diff] [blame] | 1753 | * once we do this, we must not dereference transaction |
| 1754 | * pointer again. |
| 1755 | */ |
| 1756 | tid = transaction->t_tid; |
| 1757 | if (atomic_dec_and_test(&transaction->t_updates)) { |
| 1758 | wake_up(&journal->j_wait_updates); |
| 1759 | if (journal->j_barrier_count) |
| 1760 | wake_up(&journal->j_wait_transaction_locked); |
| 1761 | } |
| 1762 | |
| 1763 | if (wait_for_commit) |
| 1764 | err = jbd2_log_wait_commit(journal, tid); |
| 1765 | |
Ingo Molnar | 3295f0e | 2008-08-11 10:30:30 +0200 | [diff] [blame] | 1766 | lock_map_release(&handle->h_lockdep_map); |
Mingming Cao | 7b75106 | 2008-01-28 23:58:27 -0500 | [diff] [blame] | 1767 | |
Jan Kara | 8f7d89f | 2013-06-04 12:35:11 -0400 | [diff] [blame] | 1768 | if (handle->h_rsv_handle) |
| 1769 | jbd2_journal_free_reserved(handle->h_rsv_handle); |
Theodore Ts'o | 41a5b91 | 2013-07-01 08:12:41 -0400 | [diff] [blame] | 1770 | free_and_exit: |
Mingming Cao | af1e76d | 2007-10-16 18:38:25 -0400 | [diff] [blame] | 1771 | jbd2_free_handle(handle); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1772 | return err; |
| 1773 | } |
| 1774 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1775 | /* |
| 1776 | * |
| 1777 | * List management code snippets: various functions for manipulating the |
| 1778 | * transaction buffer lists. |
| 1779 | * |
| 1780 | */ |
| 1781 | |
| 1782 | /* |
| 1783 | * Append a buffer to a transaction list, given the transaction's list head |
| 1784 | * pointer. |
| 1785 | * |
| 1786 | * j_list_lock is held. |
| 1787 | * |
| 1788 | * jbd_lock_bh_state(jh2bh(jh)) is held. |
| 1789 | */ |
| 1790 | |
| 1791 | static inline void |
| 1792 | __blist_add_buffer(struct journal_head **list, struct journal_head *jh) |
| 1793 | { |
| 1794 | if (!*list) { |
| 1795 | jh->b_tnext = jh->b_tprev = jh; |
| 1796 | *list = jh; |
| 1797 | } else { |
| 1798 | /* Insert at the tail of the list to preserve order */ |
| 1799 | struct journal_head *first = *list, *last = first->b_tprev; |
| 1800 | jh->b_tprev = last; |
| 1801 | jh->b_tnext = first; |
| 1802 | last->b_tnext = first->b_tprev = jh; |
| 1803 | } |
| 1804 | } |
| 1805 | |
| 1806 | /* |
| 1807 | * Remove a buffer from a transaction list, given the transaction's list |
| 1808 | * head pointer. |
| 1809 | * |
| 1810 | * Called with j_list_lock held, and the journal may not be locked. |
| 1811 | * |
| 1812 | * jbd_lock_bh_state(jh2bh(jh)) is held. |
| 1813 | */ |
| 1814 | |
| 1815 | static inline void |
| 1816 | __blist_del_buffer(struct journal_head **list, struct journal_head *jh) |
| 1817 | { |
| 1818 | if (*list == jh) { |
| 1819 | *list = jh->b_tnext; |
| 1820 | if (*list == jh) |
| 1821 | *list = NULL; |
| 1822 | } |
| 1823 | jh->b_tprev->b_tnext = jh->b_tnext; |
| 1824 | jh->b_tnext->b_tprev = jh->b_tprev; |
| 1825 | } |
| 1826 | |
| 1827 | /* |
| 1828 | * Remove a buffer from the appropriate transaction list. |
| 1829 | * |
| 1830 | * Note that this function can *change* the value of |
Jan Kara | f5113ef | 2013-06-04 12:01:45 -0400 | [diff] [blame] | 1831 | * bh->b_transaction->t_buffers, t_forget, t_shadow_list, t_log_list or |
| 1832 | * t_reserved_list. If the caller is holding onto a copy of one of these |
| 1833 | * pointers, it could go bad. Generally the caller needs to re-read the |
| 1834 | * pointer from the transaction_t. |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1835 | * |
Jan Kara | 5bebccf | 2012-03-13 22:25:06 -0400 | [diff] [blame] | 1836 | * Called under j_list_lock. |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1837 | */ |
Jan Kara | 5bebccf | 2012-03-13 22:25:06 -0400 | [diff] [blame] | 1838 | static void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh) |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1839 | { |
| 1840 | struct journal_head **list = NULL; |
| 1841 | transaction_t *transaction; |
| 1842 | struct buffer_head *bh = jh2bh(jh); |
| 1843 | |
| 1844 | J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh)); |
| 1845 | transaction = jh->b_transaction; |
| 1846 | if (transaction) |
| 1847 | assert_spin_locked(&transaction->t_journal->j_list_lock); |
| 1848 | |
| 1849 | J_ASSERT_JH(jh, jh->b_jlist < BJ_Types); |
| 1850 | if (jh->b_jlist != BJ_None) |
Mingming Cao | 4019191 | 2008-01-28 23:58:27 -0500 | [diff] [blame] | 1851 | J_ASSERT_JH(jh, transaction != NULL); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1852 | |
| 1853 | switch (jh->b_jlist) { |
| 1854 | case BJ_None: |
| 1855 | return; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1856 | case BJ_Metadata: |
| 1857 | transaction->t_nr_buffers--; |
| 1858 | J_ASSERT_JH(jh, transaction->t_nr_buffers >= 0); |
| 1859 | list = &transaction->t_buffers; |
| 1860 | break; |
| 1861 | case BJ_Forget: |
| 1862 | list = &transaction->t_forget; |
| 1863 | break; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1864 | case BJ_Shadow: |
| 1865 | list = &transaction->t_shadow_list; |
| 1866 | break; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1867 | case BJ_Reserved: |
| 1868 | list = &transaction->t_reserved_list; |
| 1869 | break; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1870 | } |
| 1871 | |
| 1872 | __blist_del_buffer(list, jh); |
| 1873 | jh->b_jlist = BJ_None; |
| 1874 | if (test_clear_buffer_jbddirty(bh)) |
| 1875 | mark_buffer_dirty(bh); /* Expose it to the VM */ |
| 1876 | } |
| 1877 | |
Jan Kara | de1b794 | 2011-06-13 15:38:22 -0400 | [diff] [blame] | 1878 | /* |
| 1879 | * Remove buffer from all transactions. |
| 1880 | * |
| 1881 | * Called with bh_state lock and j_list_lock |
| 1882 | * |
| 1883 | * jh and bh may be already freed when this function returns. |
| 1884 | */ |
| 1885 | static void __jbd2_journal_unfile_buffer(struct journal_head *jh) |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1886 | { |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1887 | __jbd2_journal_temp_unlink_buffer(jh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1888 | jh->b_transaction = NULL; |
Jan Kara | de1b794 | 2011-06-13 15:38:22 -0400 | [diff] [blame] | 1889 | jbd2_journal_put_journal_head(jh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1890 | } |
| 1891 | |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1892 | void jbd2_journal_unfile_buffer(journal_t *journal, struct journal_head *jh) |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1893 | { |
Jan Kara | de1b794 | 2011-06-13 15:38:22 -0400 | [diff] [blame] | 1894 | struct buffer_head *bh = jh2bh(jh); |
| 1895 | |
| 1896 | /* Get reference so that buffer cannot be freed before we unlock it */ |
| 1897 | get_bh(bh); |
| 1898 | jbd_lock_bh_state(bh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1899 | spin_lock(&journal->j_list_lock); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1900 | __jbd2_journal_unfile_buffer(jh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1901 | spin_unlock(&journal->j_list_lock); |
Jan Kara | de1b794 | 2011-06-13 15:38:22 -0400 | [diff] [blame] | 1902 | jbd_unlock_bh_state(bh); |
| 1903 | __brelse(bh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1904 | } |
| 1905 | |
| 1906 | /* |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1907 | * Called from jbd2_journal_try_to_free_buffers(). |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1908 | * |
| 1909 | * Called under jbd_lock_bh_state(bh) |
| 1910 | */ |
| 1911 | static void |
| 1912 | __journal_try_to_free_buffer(journal_t *journal, struct buffer_head *bh) |
| 1913 | { |
| 1914 | struct journal_head *jh; |
| 1915 | |
| 1916 | jh = bh2jh(bh); |
| 1917 | |
| 1918 | if (buffer_locked(bh) || buffer_dirty(bh)) |
| 1919 | goto out; |
| 1920 | |
Theodore Ts'o | d2eb0b9 | 2014-03-09 00:07:19 -0500 | [diff] [blame] | 1921 | if (jh->b_next_transaction != NULL || jh->b_transaction != NULL) |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1922 | goto out; |
| 1923 | |
| 1924 | spin_lock(&journal->j_list_lock); |
Theodore Ts'o | d2eb0b9 | 2014-03-09 00:07:19 -0500 | [diff] [blame] | 1925 | if (jh->b_cp_transaction != NULL) { |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1926 | /* written-back checkpointed metadata buffer */ |
Jan Kara | c254c9e | 2012-03-13 22:27:44 -0400 | [diff] [blame] | 1927 | JBUFFER_TRACE(jh, "remove from checkpoint list"); |
| 1928 | __jbd2_journal_remove_checkpoint(jh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1929 | } |
| 1930 | spin_unlock(&journal->j_list_lock); |
| 1931 | out: |
| 1932 | return; |
| 1933 | } |
| 1934 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1935 | /** |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1936 | * int jbd2_journal_try_to_free_buffers() - try to free page buffers. |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1937 | * @journal: journal for operation |
| 1938 | * @page: to try and free |
Mingming Cao | 530576b | 2008-07-13 21:06:39 -0400 | [diff] [blame] | 1939 | * @gfp_mask: we use the mask to detect how hard should we try to release |
Mel Gorman | d0164ad | 2015-11-06 16:28:21 -0800 | [diff] [blame] | 1940 | * buffers. If __GFP_DIRECT_RECLAIM and __GFP_FS is set, we wait for commit |
| 1941 | * code to release the buffers. |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1942 | * |
| 1943 | * |
| 1944 | * For all the buffers on this page, |
| 1945 | * if they are fully written out ordered data, move them onto BUF_CLEAN |
| 1946 | * so try_to_free_buffers() can reap them. |
| 1947 | * |
| 1948 | * This function returns non-zero if we wish try_to_free_buffers() |
| 1949 | * to be called. We do this if the page is releasable by try_to_free_buffers(). |
| 1950 | * We also do it if the page has locked or dirty buffers and the caller wants |
| 1951 | * us to perform sync or async writeout. |
| 1952 | * |
| 1953 | * This complicates JBD locking somewhat. We aren't protected by the |
| 1954 | * BKL here. We wish to remove the buffer from its committing or |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1955 | * running transaction's ->t_datalist via __jbd2_journal_unfile_buffer. |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1956 | * |
| 1957 | * This may *change* the value of transaction_t->t_datalist, so anyone |
| 1958 | * who looks at t_datalist needs to lock against this function. |
| 1959 | * |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1960 | * Even worse, someone may be doing a jbd2_journal_dirty_data on this |
| 1961 | * buffer. So we need to lock against that. jbd2_journal_dirty_data() |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1962 | * will come out of the lock with the buffer dirty, which makes it |
| 1963 | * ineligible for release here. |
| 1964 | * |
| 1965 | * Who else is affected by this? hmm... Really the only contender |
| 1966 | * is do_get_write_access() - it could be looking at the buffer while |
| 1967 | * journal_try_to_free_buffer() is changing its state. But that |
| 1968 | * cannot happen because we never reallocate freed data as metadata |
| 1969 | * while the data is part of a transaction. Yes? |
Mingming Cao | 530576b | 2008-07-13 21:06:39 -0400 | [diff] [blame] | 1970 | * |
| 1971 | * Return 0 on failure, 1 on success |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1972 | */ |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1973 | int jbd2_journal_try_to_free_buffers(journal_t *journal, |
Mingming Cao | 530576b | 2008-07-13 21:06:39 -0400 | [diff] [blame] | 1974 | struct page *page, gfp_t gfp_mask) |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1975 | { |
| 1976 | struct buffer_head *head; |
| 1977 | struct buffer_head *bh; |
| 1978 | int ret = 0; |
| 1979 | |
| 1980 | J_ASSERT(PageLocked(page)); |
| 1981 | |
| 1982 | head = page_buffers(page); |
| 1983 | bh = head; |
| 1984 | do { |
| 1985 | struct journal_head *jh; |
| 1986 | |
| 1987 | /* |
| 1988 | * We take our own ref against the journal_head here to avoid |
| 1989 | * having to add tons of locking around each instance of |
Mingming Cao | 530576b | 2008-07-13 21:06:39 -0400 | [diff] [blame] | 1990 | * jbd2_journal_put_journal_head(). |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1991 | */ |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1992 | jh = jbd2_journal_grab_journal_head(bh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1993 | if (!jh) |
| 1994 | continue; |
| 1995 | |
| 1996 | jbd_lock_bh_state(bh); |
| 1997 | __journal_try_to_free_buffer(journal, bh); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 1998 | jbd2_journal_put_journal_head(jh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 1999 | jbd_unlock_bh_state(bh); |
| 2000 | if (buffer_jbd(bh)) |
| 2001 | goto busy; |
| 2002 | } while ((bh = bh->b_this_page) != head); |
Mingming Cao | 530576b | 2008-07-13 21:06:39 -0400 | [diff] [blame] | 2003 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2004 | ret = try_to_free_buffers(page); |
Mingming Cao | 530576b | 2008-07-13 21:06:39 -0400 | [diff] [blame] | 2005 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2006 | busy: |
| 2007 | return ret; |
| 2008 | } |
| 2009 | |
| 2010 | /* |
| 2011 | * This buffer is no longer needed. If it is on an older transaction's |
| 2012 | * checkpoint list we need to record it on this transaction's forget list |
| 2013 | * to pin this buffer (and hence its checkpointing transaction) down until |
| 2014 | * this transaction commits. If the buffer isn't on a checkpoint list, we |
| 2015 | * release it. |
| 2016 | * Returns non-zero if JBD no longer has an interest in the buffer. |
| 2017 | * |
| 2018 | * Called under j_list_lock. |
| 2019 | * |
| 2020 | * Called under jbd_lock_bh_state(bh). |
| 2021 | */ |
| 2022 | static int __dispose_buffer(struct journal_head *jh, transaction_t *transaction) |
| 2023 | { |
| 2024 | int may_free = 1; |
| 2025 | struct buffer_head *bh = jh2bh(jh); |
| 2026 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2027 | if (jh->b_cp_transaction) { |
| 2028 | JBUFFER_TRACE(jh, "on running+cp transaction"); |
Jan Kara | de1b794 | 2011-06-13 15:38:22 -0400 | [diff] [blame] | 2029 | __jbd2_journal_temp_unlink_buffer(jh); |
Jan Kara | f91d1d0 | 2009-07-13 16:16:20 -0400 | [diff] [blame] | 2030 | /* |
| 2031 | * We don't want to write the buffer anymore, clear the |
| 2032 | * bit so that we don't confuse checks in |
| 2033 | * __journal_file_buffer |
| 2034 | */ |
| 2035 | clear_buffer_dirty(bh); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 2036 | __jbd2_journal_file_buffer(jh, transaction, BJ_Forget); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2037 | may_free = 0; |
| 2038 | } else { |
| 2039 | JBUFFER_TRACE(jh, "on running transaction"); |
Jan Kara | de1b794 | 2011-06-13 15:38:22 -0400 | [diff] [blame] | 2040 | __jbd2_journal_unfile_buffer(jh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2041 | } |
| 2042 | return may_free; |
| 2043 | } |
| 2044 | |
| 2045 | /* |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 2046 | * jbd2_journal_invalidatepage |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2047 | * |
| 2048 | * This code is tricky. It has a number of cases to deal with. |
| 2049 | * |
| 2050 | * There are two invariants which this code relies on: |
| 2051 | * |
| 2052 | * i_size must be updated on disk before we start calling invalidatepage on the |
| 2053 | * data. |
| 2054 | * |
| 2055 | * This is done in ext3 by defining an ext3_setattr method which |
| 2056 | * updates i_size before truncate gets going. By maintaining this |
| 2057 | * invariant, we can be sure that it is safe to throw away any buffers |
| 2058 | * attached to the current transaction: once the transaction commits, |
| 2059 | * we know that the data will not be needed. |
| 2060 | * |
| 2061 | * Note however that we can *not* throw away data belonging to the |
| 2062 | * previous, committing transaction! |
| 2063 | * |
| 2064 | * Any disk blocks which *are* part of the previous, committing |
| 2065 | * transaction (and which therefore cannot be discarded immediately) are |
| 2066 | * not going to be reused in the new running transaction |
| 2067 | * |
| 2068 | * The bitmap committed_data images guarantee this: any block which is |
| 2069 | * allocated in one transaction and removed in the next will be marked |
| 2070 | * as in-use in the committed_data bitmap, so cannot be reused until |
| 2071 | * the next transaction to delete the block commits. This means that |
| 2072 | * leaving committing buffers dirty is quite safe: the disk blocks |
| 2073 | * cannot be reallocated to a different file and so buffer aliasing is |
| 2074 | * not possible. |
| 2075 | * |
| 2076 | * |
| 2077 | * The above applies mainly to ordered data mode. In writeback mode we |
| 2078 | * don't make guarantees about the order in which data hits disk --- in |
| 2079 | * particular we don't guarantee that new dirty data is flushed before |
| 2080 | * transaction commit --- so it is always safe just to discard data |
| 2081 | * immediately in that mode. --sct |
| 2082 | */ |
| 2083 | |
| 2084 | /* |
| 2085 | * The journal_unmap_buffer helper function returns zero if the buffer |
| 2086 | * concerned remains pinned as an anonymous buffer belonging to an older |
| 2087 | * transaction. |
| 2088 | * |
| 2089 | * We're outside-transaction here. Either or both of j_running_transaction |
| 2090 | * and j_committing_transaction may be NULL. |
| 2091 | */ |
Jan Kara | b794e7a | 2012-09-26 23:11:13 -0400 | [diff] [blame] | 2092 | static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh, |
| 2093 | int partial_page) |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2094 | { |
| 2095 | transaction_t *transaction; |
| 2096 | struct journal_head *jh; |
| 2097 | int may_free = 1; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2098 | |
| 2099 | BUFFER_TRACE(bh, "entry"); |
| 2100 | |
| 2101 | /* |
| 2102 | * It is safe to proceed here without the j_list_lock because the |
| 2103 | * buffers cannot be stolen by try_to_free_buffers as long as we are |
| 2104 | * holding the page lock. --sct |
| 2105 | */ |
| 2106 | |
| 2107 | if (!buffer_jbd(bh)) |
| 2108 | goto zap_buffer_unlocked; |
| 2109 | |
Jan Kara | 87c89c2 | 2008-07-11 19:27:31 -0400 | [diff] [blame] | 2110 | /* OK, we have data buffer in journaled mode */ |
Theodore Ts'o | a931da6 | 2010-08-03 21:35:12 -0400 | [diff] [blame] | 2111 | write_lock(&journal->j_state_lock); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2112 | jbd_lock_bh_state(bh); |
| 2113 | spin_lock(&journal->j_list_lock); |
| 2114 | |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 2115 | jh = jbd2_journal_grab_journal_head(bh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2116 | if (!jh) |
| 2117 | goto zap_buffer_no_jh; |
| 2118 | |
dingdinghua | ba86902 | 2010-02-15 16:35:42 -0500 | [diff] [blame] | 2119 | /* |
| 2120 | * We cannot remove the buffer from checkpoint lists until the |
| 2121 | * transaction adding inode to orphan list (let's call it T) |
| 2122 | * is committed. Otherwise if the transaction changing the |
| 2123 | * buffer would be cleaned from the journal before T is |
| 2124 | * committed, a crash will cause that the correct contents of |
| 2125 | * the buffer will be lost. On the other hand we have to |
| 2126 | * clear the buffer dirty bit at latest at the moment when the |
| 2127 | * transaction marking the buffer as freed in the filesystem |
| 2128 | * structures is committed because from that moment on the |
Jan Kara | b794e7a | 2012-09-26 23:11:13 -0400 | [diff] [blame] | 2129 | * block can be reallocated and used by a different page. |
dingdinghua | ba86902 | 2010-02-15 16:35:42 -0500 | [diff] [blame] | 2130 | * Since the block hasn't been freed yet but the inode has |
| 2131 | * already been added to orphan list, it is safe for us to add |
| 2132 | * the buffer to BJ_Forget list of the newest transaction. |
Jan Kara | b794e7a | 2012-09-26 23:11:13 -0400 | [diff] [blame] | 2133 | * |
| 2134 | * Also we have to clear buffer_mapped flag of a truncated buffer |
| 2135 | * because the buffer_head may be attached to the page straddling |
| 2136 | * i_size (can happen only when blocksize < pagesize) and thus the |
| 2137 | * buffer_head can be reused when the file is extended again. So we end |
| 2138 | * up keeping around invalidated buffers attached to transactions' |
| 2139 | * BJ_Forget list just to stop checkpointing code from cleaning up |
| 2140 | * the transaction this buffer was modified in. |
dingdinghua | ba86902 | 2010-02-15 16:35:42 -0500 | [diff] [blame] | 2141 | */ |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2142 | transaction = jh->b_transaction; |
| 2143 | if (transaction == NULL) { |
| 2144 | /* First case: not on any transaction. If it |
| 2145 | * has no checkpoint link, then we can zap it: |
| 2146 | * it's a writeback-mode buffer so we don't care |
| 2147 | * if it hits disk safely. */ |
| 2148 | if (!jh->b_cp_transaction) { |
| 2149 | JBUFFER_TRACE(jh, "not on any transaction: zap"); |
| 2150 | goto zap_buffer; |
| 2151 | } |
| 2152 | |
| 2153 | if (!buffer_dirty(bh)) { |
| 2154 | /* bdflush has written it. We can drop it now */ |
| 2155 | goto zap_buffer; |
| 2156 | } |
| 2157 | |
| 2158 | /* OK, it must be in the journal but still not |
| 2159 | * written fully to disk: it's metadata or |
| 2160 | * journaled data... */ |
| 2161 | |
| 2162 | if (journal->j_running_transaction) { |
| 2163 | /* ... and once the current transaction has |
| 2164 | * committed, the buffer won't be needed any |
| 2165 | * longer. */ |
| 2166 | JBUFFER_TRACE(jh, "checkpointed: add to BJ_Forget"); |
Jan Kara | b794e7a | 2012-09-26 23:11:13 -0400 | [diff] [blame] | 2167 | may_free = __dispose_buffer(jh, |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2168 | journal->j_running_transaction); |
Jan Kara | b794e7a | 2012-09-26 23:11:13 -0400 | [diff] [blame] | 2169 | goto zap_buffer; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2170 | } else { |
| 2171 | /* There is no currently-running transaction. So the |
| 2172 | * orphan record which we wrote for this file must have |
| 2173 | * passed into commit. We must attach this buffer to |
| 2174 | * the committing transaction, if it exists. */ |
| 2175 | if (journal->j_committing_transaction) { |
| 2176 | JBUFFER_TRACE(jh, "give to committing trans"); |
Jan Kara | b794e7a | 2012-09-26 23:11:13 -0400 | [diff] [blame] | 2177 | may_free = __dispose_buffer(jh, |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2178 | journal->j_committing_transaction); |
Jan Kara | b794e7a | 2012-09-26 23:11:13 -0400 | [diff] [blame] | 2179 | goto zap_buffer; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2180 | } else { |
| 2181 | /* The orphan record's transaction has |
| 2182 | * committed. We can cleanse this buffer */ |
| 2183 | clear_buffer_jbddirty(bh); |
| 2184 | goto zap_buffer; |
| 2185 | } |
| 2186 | } |
| 2187 | } else if (transaction == journal->j_committing_transaction) { |
Eric Sandeen | 9b57988 | 2006-10-28 10:38:28 -0700 | [diff] [blame] | 2188 | JBUFFER_TRACE(jh, "on committing transaction"); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2189 | /* |
dingdinghua | ba86902 | 2010-02-15 16:35:42 -0500 | [diff] [blame] | 2190 | * The buffer is committing, we simply cannot touch |
Jan Kara | b794e7a | 2012-09-26 23:11:13 -0400 | [diff] [blame] | 2191 | * it. If the page is straddling i_size we have to wait |
| 2192 | * for commit and try again. |
| 2193 | */ |
| 2194 | if (partial_page) { |
Jan Kara | b794e7a | 2012-09-26 23:11:13 -0400 | [diff] [blame] | 2195 | jbd2_journal_put_journal_head(jh); |
| 2196 | spin_unlock(&journal->j_list_lock); |
| 2197 | jbd_unlock_bh_state(bh); |
| 2198 | write_unlock(&journal->j_state_lock); |
Jan Kara | 53e8726 | 2012-12-25 13:29:52 -0500 | [diff] [blame] | 2199 | return -EBUSY; |
Jan Kara | b794e7a | 2012-09-26 23:11:13 -0400 | [diff] [blame] | 2200 | } |
| 2201 | /* |
| 2202 | * OK, buffer won't be reachable after truncate. We just set |
| 2203 | * j_next_transaction to the running transaction (if there is |
| 2204 | * one) and mark buffer as freed so that commit code knows it |
| 2205 | * should clear dirty bits when it is done with the buffer. |
dingdinghua | ba86902 | 2010-02-15 16:35:42 -0500 | [diff] [blame] | 2206 | */ |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2207 | set_buffer_freed(bh); |
dingdinghua | ba86902 | 2010-02-15 16:35:42 -0500 | [diff] [blame] | 2208 | if (journal->j_running_transaction && buffer_jbddirty(bh)) |
| 2209 | jh->b_next_transaction = journal->j_running_transaction; |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 2210 | jbd2_journal_put_journal_head(jh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2211 | spin_unlock(&journal->j_list_lock); |
| 2212 | jbd_unlock_bh_state(bh); |
Theodore Ts'o | a931da6 | 2010-08-03 21:35:12 -0400 | [diff] [blame] | 2213 | write_unlock(&journal->j_state_lock); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2214 | return 0; |
| 2215 | } else { |
| 2216 | /* Good, the buffer belongs to the running transaction. |
| 2217 | * We are writing our own transaction's data, not any |
| 2218 | * previous one's, so it is safe to throw it away |
| 2219 | * (remember that we expect the filesystem to have set |
| 2220 | * i_size already for this truncate so recovery will not |
| 2221 | * expose the disk blocks we are discarding here.) */ |
| 2222 | J_ASSERT_JH(jh, transaction == journal->j_running_transaction); |
Eric Sandeen | 9b57988 | 2006-10-28 10:38:28 -0700 | [diff] [blame] | 2223 | JBUFFER_TRACE(jh, "on running transaction"); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2224 | may_free = __dispose_buffer(jh, transaction); |
| 2225 | } |
| 2226 | |
| 2227 | zap_buffer: |
Jan Kara | b794e7a | 2012-09-26 23:11:13 -0400 | [diff] [blame] | 2228 | /* |
| 2229 | * This is tricky. Although the buffer is truncated, it may be reused |
| 2230 | * if blocksize < pagesize and it is attached to the page straddling |
| 2231 | * EOF. Since the buffer might have been added to BJ_Forget list of the |
| 2232 | * running transaction, journal_get_write_access() won't clear |
| 2233 | * b_modified and credit accounting gets confused. So clear b_modified |
| 2234 | * here. |
| 2235 | */ |
| 2236 | jh->b_modified = 0; |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 2237 | jbd2_journal_put_journal_head(jh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2238 | zap_buffer_no_jh: |
| 2239 | spin_unlock(&journal->j_list_lock); |
| 2240 | jbd_unlock_bh_state(bh); |
Theodore Ts'o | a931da6 | 2010-08-03 21:35:12 -0400 | [diff] [blame] | 2241 | write_unlock(&journal->j_state_lock); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2242 | zap_buffer_unlocked: |
| 2243 | clear_buffer_dirty(bh); |
| 2244 | J_ASSERT_BH(bh, !buffer_jbddirty(bh)); |
| 2245 | clear_buffer_mapped(bh); |
| 2246 | clear_buffer_req(bh); |
| 2247 | clear_buffer_new(bh); |
Eric Sandeen | 1529116 | 2012-02-20 17:53:01 -0500 | [diff] [blame] | 2248 | clear_buffer_delay(bh); |
| 2249 | clear_buffer_unwritten(bh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2250 | bh->b_bdev = NULL; |
| 2251 | return may_free; |
| 2252 | } |
| 2253 | |
| 2254 | /** |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 2255 | * void jbd2_journal_invalidatepage() |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2256 | * @journal: journal to use for flush... |
| 2257 | * @page: page to flush |
Lukas Czerner | 259709b | 2013-05-21 23:20:03 -0400 | [diff] [blame] | 2258 | * @offset: start of the range to invalidate |
| 2259 | * @length: length of the range to invalidate |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2260 | * |
Lukas Czerner | 259709b | 2013-05-21 23:20:03 -0400 | [diff] [blame] | 2261 | * Reap page buffers containing data after in the specified range in page. |
| 2262 | * Can return -EBUSY if buffers are part of the committing transaction and |
| 2263 | * the page is straddling i_size. Caller then has to wait for current commit |
| 2264 | * and try again. |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2265 | */ |
Jan Kara | 53e8726 | 2012-12-25 13:29:52 -0500 | [diff] [blame] | 2266 | int jbd2_journal_invalidatepage(journal_t *journal, |
| 2267 | struct page *page, |
Lukas Czerner | 259709b | 2013-05-21 23:20:03 -0400 | [diff] [blame] | 2268 | unsigned int offset, |
| 2269 | unsigned int length) |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2270 | { |
| 2271 | struct buffer_head *head, *bh, *next; |
Lukas Czerner | 259709b | 2013-05-21 23:20:03 -0400 | [diff] [blame] | 2272 | unsigned int stop = offset + length; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2273 | unsigned int curr_off = 0; |
Lukas Czerner | 259709b | 2013-05-21 23:20:03 -0400 | [diff] [blame] | 2274 | int partial_page = (offset || length < PAGE_CACHE_SIZE); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2275 | int may_free = 1; |
Jan Kara | 53e8726 | 2012-12-25 13:29:52 -0500 | [diff] [blame] | 2276 | int ret = 0; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2277 | |
| 2278 | if (!PageLocked(page)) |
| 2279 | BUG(); |
| 2280 | if (!page_has_buffers(page)) |
Jan Kara | 53e8726 | 2012-12-25 13:29:52 -0500 | [diff] [blame] | 2281 | return 0; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2282 | |
Lukas Czerner | 259709b | 2013-05-21 23:20:03 -0400 | [diff] [blame] | 2283 | BUG_ON(stop > PAGE_CACHE_SIZE || stop < length); |
| 2284 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2285 | /* We will potentially be playing with lists other than just the |
| 2286 | * data lists (especially for journaled data mode), so be |
| 2287 | * cautious in our locking. */ |
| 2288 | |
| 2289 | head = bh = page_buffers(page); |
| 2290 | do { |
| 2291 | unsigned int next_off = curr_off + bh->b_size; |
| 2292 | next = bh->b_this_page; |
| 2293 | |
Lukas Czerner | 259709b | 2013-05-21 23:20:03 -0400 | [diff] [blame] | 2294 | if (next_off > stop) |
| 2295 | return 0; |
| 2296 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2297 | if (offset <= curr_off) { |
| 2298 | /* This block is wholly outside the truncation point */ |
| 2299 | lock_buffer(bh); |
Lukas Czerner | 259709b | 2013-05-21 23:20:03 -0400 | [diff] [blame] | 2300 | ret = journal_unmap_buffer(journal, bh, partial_page); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2301 | unlock_buffer(bh); |
Jan Kara | 53e8726 | 2012-12-25 13:29:52 -0500 | [diff] [blame] | 2302 | if (ret < 0) |
| 2303 | return ret; |
| 2304 | may_free &= ret; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2305 | } |
| 2306 | curr_off = next_off; |
| 2307 | bh = next; |
| 2308 | |
| 2309 | } while (bh != head); |
| 2310 | |
Lukas Czerner | 259709b | 2013-05-21 23:20:03 -0400 | [diff] [blame] | 2311 | if (!partial_page) { |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2312 | if (may_free && try_to_free_buffers(page)) |
| 2313 | J_ASSERT(!page_has_buffers(page)); |
| 2314 | } |
Jan Kara | 53e8726 | 2012-12-25 13:29:52 -0500 | [diff] [blame] | 2315 | return 0; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2316 | } |
| 2317 | |
| 2318 | /* |
| 2319 | * File a buffer on the given transaction list. |
| 2320 | */ |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 2321 | void __jbd2_journal_file_buffer(struct journal_head *jh, |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2322 | transaction_t *transaction, int jlist) |
| 2323 | { |
| 2324 | struct journal_head **list = NULL; |
| 2325 | int was_dirty = 0; |
| 2326 | struct buffer_head *bh = jh2bh(jh); |
| 2327 | |
| 2328 | J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh)); |
| 2329 | assert_spin_locked(&transaction->t_journal->j_list_lock); |
| 2330 | |
| 2331 | J_ASSERT_JH(jh, jh->b_jlist < BJ_Types); |
| 2332 | J_ASSERT_JH(jh, jh->b_transaction == transaction || |
Mingming Cao | 4019191 | 2008-01-28 23:58:27 -0500 | [diff] [blame] | 2333 | jh->b_transaction == NULL); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2334 | |
| 2335 | if (jh->b_transaction && jh->b_jlist == jlist) |
| 2336 | return; |
| 2337 | |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2338 | if (jlist == BJ_Metadata || jlist == BJ_Reserved || |
| 2339 | jlist == BJ_Shadow || jlist == BJ_Forget) { |
Jan Kara | f91d1d0 | 2009-07-13 16:16:20 -0400 | [diff] [blame] | 2340 | /* |
| 2341 | * For metadata buffers, we track dirty bit in buffer_jbddirty |
| 2342 | * instead of buffer_dirty. We should not see a dirty bit set |
| 2343 | * here because we clear it in do_get_write_access but e.g. |
| 2344 | * tune2fs can modify the sb and set the dirty bit at any time |
| 2345 | * so we try to gracefully handle that. |
| 2346 | */ |
| 2347 | if (buffer_dirty(bh)) |
| 2348 | warn_dirty_buffer(bh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2349 | if (test_clear_buffer_dirty(bh) || |
| 2350 | test_clear_buffer_jbddirty(bh)) |
| 2351 | was_dirty = 1; |
| 2352 | } |
| 2353 | |
| 2354 | if (jh->b_transaction) |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 2355 | __jbd2_journal_temp_unlink_buffer(jh); |
Jan Kara | de1b794 | 2011-06-13 15:38:22 -0400 | [diff] [blame] | 2356 | else |
| 2357 | jbd2_journal_grab_journal_head(bh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2358 | jh->b_transaction = transaction; |
| 2359 | |
| 2360 | switch (jlist) { |
| 2361 | case BJ_None: |
| 2362 | J_ASSERT_JH(jh, !jh->b_committed_data); |
| 2363 | J_ASSERT_JH(jh, !jh->b_frozen_data); |
| 2364 | return; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2365 | case BJ_Metadata: |
| 2366 | transaction->t_nr_buffers++; |
| 2367 | list = &transaction->t_buffers; |
| 2368 | break; |
| 2369 | case BJ_Forget: |
| 2370 | list = &transaction->t_forget; |
| 2371 | break; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2372 | case BJ_Shadow: |
| 2373 | list = &transaction->t_shadow_list; |
| 2374 | break; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2375 | case BJ_Reserved: |
| 2376 | list = &transaction->t_reserved_list; |
| 2377 | break; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2378 | } |
| 2379 | |
| 2380 | __blist_add_buffer(list, jh); |
| 2381 | jh->b_jlist = jlist; |
| 2382 | |
| 2383 | if (was_dirty) |
| 2384 | set_buffer_jbddirty(bh); |
| 2385 | } |
| 2386 | |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 2387 | void jbd2_journal_file_buffer(struct journal_head *jh, |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2388 | transaction_t *transaction, int jlist) |
| 2389 | { |
| 2390 | jbd_lock_bh_state(jh2bh(jh)); |
| 2391 | spin_lock(&transaction->t_journal->j_list_lock); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 2392 | __jbd2_journal_file_buffer(jh, transaction, jlist); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2393 | spin_unlock(&transaction->t_journal->j_list_lock); |
| 2394 | jbd_unlock_bh_state(jh2bh(jh)); |
| 2395 | } |
| 2396 | |
| 2397 | /* |
| 2398 | * Remove a buffer from its current buffer list in preparation for |
| 2399 | * dropping it from its current transaction entirely. If the buffer has |
| 2400 | * already started to be used by a subsequent transaction, refile the |
| 2401 | * buffer on that transaction's metadata list. |
| 2402 | * |
Jan Kara | de1b794 | 2011-06-13 15:38:22 -0400 | [diff] [blame] | 2403 | * Called under j_list_lock |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2404 | * Called under jbd_lock_bh_state(jh2bh(jh)) |
Jan Kara | de1b794 | 2011-06-13 15:38:22 -0400 | [diff] [blame] | 2405 | * |
| 2406 | * jh and bh may be already free when this function returns |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2407 | */ |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 2408 | void __jbd2_journal_refile_buffer(struct journal_head *jh) |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2409 | { |
dingdinghua | ba86902 | 2010-02-15 16:35:42 -0500 | [diff] [blame] | 2410 | int was_dirty, jlist; |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2411 | struct buffer_head *bh = jh2bh(jh); |
| 2412 | |
| 2413 | J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh)); |
| 2414 | if (jh->b_transaction) |
| 2415 | assert_spin_locked(&jh->b_transaction->t_journal->j_list_lock); |
| 2416 | |
| 2417 | /* If the buffer is now unused, just drop it. */ |
| 2418 | if (jh->b_next_transaction == NULL) { |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 2419 | __jbd2_journal_unfile_buffer(jh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2420 | return; |
| 2421 | } |
| 2422 | |
| 2423 | /* |
| 2424 | * It has been modified by a later transaction: add it to the new |
| 2425 | * transaction's metadata list. |
| 2426 | */ |
| 2427 | |
| 2428 | was_dirty = test_clear_buffer_jbddirty(bh); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 2429 | __jbd2_journal_temp_unlink_buffer(jh); |
Jan Kara | de1b794 | 2011-06-13 15:38:22 -0400 | [diff] [blame] | 2430 | /* |
| 2431 | * We set b_transaction here because b_next_transaction will inherit |
| 2432 | * our jh reference and thus __jbd2_journal_file_buffer() must not |
| 2433 | * take a new one. |
| 2434 | */ |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2435 | jh->b_transaction = jh->b_next_transaction; |
| 2436 | jh->b_next_transaction = NULL; |
dingdinghua | ba86902 | 2010-02-15 16:35:42 -0500 | [diff] [blame] | 2437 | if (buffer_freed(bh)) |
| 2438 | jlist = BJ_Forget; |
| 2439 | else if (jh->b_modified) |
| 2440 | jlist = BJ_Metadata; |
| 2441 | else |
| 2442 | jlist = BJ_Reserved; |
| 2443 | __jbd2_journal_file_buffer(jh, jh->b_transaction, jlist); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2444 | J_ASSERT_JH(jh, jh->b_transaction->t_state == T_RUNNING); |
| 2445 | |
| 2446 | if (was_dirty) |
| 2447 | set_buffer_jbddirty(bh); |
| 2448 | } |
| 2449 | |
| 2450 | /* |
Jan Kara | de1b794 | 2011-06-13 15:38:22 -0400 | [diff] [blame] | 2451 | * __jbd2_journal_refile_buffer() with necessary locking added. We take our |
| 2452 | * bh reference so that we can safely unlock bh. |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2453 | * |
Jan Kara | de1b794 | 2011-06-13 15:38:22 -0400 | [diff] [blame] | 2454 | * The jh and bh may be freed by this call. |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2455 | */ |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 2456 | void jbd2_journal_refile_buffer(journal_t *journal, struct journal_head *jh) |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2457 | { |
| 2458 | struct buffer_head *bh = jh2bh(jh); |
| 2459 | |
Jan Kara | de1b794 | 2011-06-13 15:38:22 -0400 | [diff] [blame] | 2460 | /* Get reference so that buffer cannot be freed before we unlock it */ |
| 2461 | get_bh(bh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2462 | jbd_lock_bh_state(bh); |
| 2463 | spin_lock(&journal->j_list_lock); |
Mingming Cao | f7f4bcc | 2006-10-11 01:20:59 -0700 | [diff] [blame] | 2464 | __jbd2_journal_refile_buffer(jh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2465 | jbd_unlock_bh_state(bh); |
Dave Kleikamp | 470decc | 2006-10-11 01:20:57 -0700 | [diff] [blame] | 2466 | spin_unlock(&journal->j_list_lock); |
| 2467 | __brelse(bh); |
| 2468 | } |
Jan Kara | c851ed5 | 2008-07-11 19:27:31 -0400 | [diff] [blame] | 2469 | |
| 2470 | /* |
| 2471 | * File inode in the inode list of the handle's transaction |
| 2472 | */ |
| 2473 | int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *jinode) |
| 2474 | { |
| 2475 | transaction_t *transaction = handle->h_transaction; |
Theodore Ts'o | 41a5b91 | 2013-07-01 08:12:41 -0400 | [diff] [blame] | 2476 | journal_t *journal; |
Jan Kara | c851ed5 | 2008-07-11 19:27:31 -0400 | [diff] [blame] | 2477 | |
| 2478 | if (is_handle_aborted(handle)) |
Theodore Ts'o | 41a5b91 | 2013-07-01 08:12:41 -0400 | [diff] [blame] | 2479 | return -EROFS; |
| 2480 | journal = transaction->t_journal; |
Jan Kara | c851ed5 | 2008-07-11 19:27:31 -0400 | [diff] [blame] | 2481 | |
| 2482 | jbd_debug(4, "Adding inode %lu, tid:%d\n", jinode->i_vfs_inode->i_ino, |
| 2483 | transaction->t_tid); |
| 2484 | |
| 2485 | /* |
| 2486 | * First check whether inode isn't already on the transaction's |
| 2487 | * lists without taking the lock. Note that this check is safe |
| 2488 | * without the lock as we cannot race with somebody removing inode |
| 2489 | * from the transaction. The reason is that we remove inode from the |
| 2490 | * transaction only in journal_release_jbd_inode() and when we commit |
| 2491 | * the transaction. We are guarded from the first case by holding |
| 2492 | * a reference to the inode. We are safe against the second case |
| 2493 | * because if jinode->i_transaction == transaction, commit code |
| 2494 | * cannot touch the transaction because we hold reference to it, |
| 2495 | * and if jinode->i_next_transaction == transaction, commit code |
| 2496 | * will only file the inode where we want it. |
| 2497 | */ |
| 2498 | if (jinode->i_transaction == transaction || |
| 2499 | jinode->i_next_transaction == transaction) |
| 2500 | return 0; |
| 2501 | |
| 2502 | spin_lock(&journal->j_list_lock); |
| 2503 | |
| 2504 | if (jinode->i_transaction == transaction || |
| 2505 | jinode->i_next_transaction == transaction) |
| 2506 | goto done; |
| 2507 | |
Jan Kara | 81be12c | 2011-05-24 11:52:40 -0400 | [diff] [blame] | 2508 | /* |
| 2509 | * We only ever set this variable to 1 so the test is safe. Since |
| 2510 | * t_need_data_flush is likely to be set, we do the test to save some |
| 2511 | * cacheline bouncing |
| 2512 | */ |
| 2513 | if (!transaction->t_need_data_flush) |
| 2514 | transaction->t_need_data_flush = 1; |
Jan Kara | c851ed5 | 2008-07-11 19:27:31 -0400 | [diff] [blame] | 2515 | /* On some different transaction's list - should be |
| 2516 | * the committing one */ |
| 2517 | if (jinode->i_transaction) { |
| 2518 | J_ASSERT(jinode->i_next_transaction == NULL); |
| 2519 | J_ASSERT(jinode->i_transaction == |
| 2520 | journal->j_committing_transaction); |
| 2521 | jinode->i_next_transaction = transaction; |
| 2522 | goto done; |
| 2523 | } |
| 2524 | /* Not on any transaction list... */ |
| 2525 | J_ASSERT(!jinode->i_next_transaction); |
| 2526 | jinode->i_transaction = transaction; |
| 2527 | list_add(&jinode->i_list, &transaction->t_inode_list); |
| 2528 | done: |
| 2529 | spin_unlock(&journal->j_list_lock); |
| 2530 | |
| 2531 | return 0; |
| 2532 | } |
| 2533 | |
| 2534 | /* |
Jan Kara | 7f5aa21 | 2009-02-10 11:15:34 -0500 | [diff] [blame] | 2535 | * File truncate and transaction commit interact with each other in a |
| 2536 | * non-trivial way. If a transaction writing data block A is |
| 2537 | * committing, we cannot discard the data by truncate until we have |
| 2538 | * written them. Otherwise if we crashed after the transaction with |
| 2539 | * write has committed but before the transaction with truncate has |
| 2540 | * committed, we could see stale data in block A. This function is a |
| 2541 | * helper to solve this problem. It starts writeout of the truncated |
| 2542 | * part in case it is in the committing transaction. |
| 2543 | * |
| 2544 | * Filesystem code must call this function when inode is journaled in |
| 2545 | * ordered mode before truncation happens and after the inode has been |
| 2546 | * placed on orphan list with the new inode size. The second condition |
| 2547 | * avoids the race that someone writes new data and we start |
| 2548 | * committing the transaction after this function has been called but |
| 2549 | * before a transaction for truncate is started (and furthermore it |
| 2550 | * allows us to optimize the case where the addition to orphan list |
| 2551 | * happens in the same transaction as write --- we don't have to write |
| 2552 | * any data in such case). |
Jan Kara | c851ed5 | 2008-07-11 19:27:31 -0400 | [diff] [blame] | 2553 | */ |
Jan Kara | 7f5aa21 | 2009-02-10 11:15:34 -0500 | [diff] [blame] | 2554 | int jbd2_journal_begin_ordered_truncate(journal_t *journal, |
| 2555 | struct jbd2_inode *jinode, |
Jan Kara | c851ed5 | 2008-07-11 19:27:31 -0400 | [diff] [blame] | 2556 | loff_t new_size) |
| 2557 | { |
Jan Kara | 7f5aa21 | 2009-02-10 11:15:34 -0500 | [diff] [blame] | 2558 | transaction_t *inode_trans, *commit_trans; |
Jan Kara | c851ed5 | 2008-07-11 19:27:31 -0400 | [diff] [blame] | 2559 | int ret = 0; |
| 2560 | |
Jan Kara | 7f5aa21 | 2009-02-10 11:15:34 -0500 | [diff] [blame] | 2561 | /* This is a quick check to avoid locking if not necessary */ |
| 2562 | if (!jinode->i_transaction) |
Jan Kara | c851ed5 | 2008-07-11 19:27:31 -0400 | [diff] [blame] | 2563 | goto out; |
Jan Kara | 7f5aa21 | 2009-02-10 11:15:34 -0500 | [diff] [blame] | 2564 | /* Locks are here just to force reading of recent values, it is |
| 2565 | * enough that the transaction was not committing before we started |
| 2566 | * a transaction adding the inode to orphan list */ |
Theodore Ts'o | a931da6 | 2010-08-03 21:35:12 -0400 | [diff] [blame] | 2567 | read_lock(&journal->j_state_lock); |
Jan Kara | c851ed5 | 2008-07-11 19:27:31 -0400 | [diff] [blame] | 2568 | commit_trans = journal->j_committing_transaction; |
Theodore Ts'o | a931da6 | 2010-08-03 21:35:12 -0400 | [diff] [blame] | 2569 | read_unlock(&journal->j_state_lock); |
Jan Kara | 7f5aa21 | 2009-02-10 11:15:34 -0500 | [diff] [blame] | 2570 | spin_lock(&journal->j_list_lock); |
| 2571 | inode_trans = jinode->i_transaction; |
| 2572 | spin_unlock(&journal->j_list_lock); |
| 2573 | if (inode_trans == commit_trans) { |
| 2574 | ret = filemap_fdatawrite_range(jinode->i_vfs_inode->i_mapping, |
Jan Kara | c851ed5 | 2008-07-11 19:27:31 -0400 | [diff] [blame] | 2575 | new_size, LLONG_MAX); |
| 2576 | if (ret) |
| 2577 | jbd2_journal_abort(journal, ret); |
| 2578 | } |
| 2579 | out: |
| 2580 | return ret; |
| 2581 | } |