1470decc6SDave Kleikamp /* 258862699SUwe Kleine-König * linux/fs/jbd2/transaction.c 3470decc6SDave Kleikamp * 4470decc6SDave Kleikamp * Written by Stephen C. Tweedie <sct@redhat.com>, 1998 5470decc6SDave Kleikamp * 6470decc6SDave Kleikamp * Copyright 1998 Red Hat corp --- All Rights Reserved 7470decc6SDave Kleikamp * 8470decc6SDave Kleikamp * This file is part of the Linux kernel and is made available under 9470decc6SDave Kleikamp * the terms of the GNU General Public License, version 2, or at your 10470decc6SDave Kleikamp * option, any later version, incorporated herein by reference. 11470decc6SDave Kleikamp * 12470decc6SDave Kleikamp * Generic filesystem transaction handling code; part of the ext2fs 13470decc6SDave Kleikamp * journaling system. 14470decc6SDave Kleikamp * 15470decc6SDave Kleikamp * This file manages transactions (compound commits managed by the 16470decc6SDave Kleikamp * journaling code) and handles (individual atomic operations by the 17470decc6SDave Kleikamp * filesystem). 18470decc6SDave Kleikamp */ 19470decc6SDave Kleikamp 20470decc6SDave Kleikamp #include <linux/time.h> 21470decc6SDave Kleikamp #include <linux/fs.h> 22f7f4bccbSMingming Cao #include <linux/jbd2.h> 23470decc6SDave Kleikamp #include <linux/errno.h> 24470decc6SDave Kleikamp #include <linux/slab.h> 25470decc6SDave Kleikamp #include <linux/timer.h> 26470decc6SDave Kleikamp #include <linux/mm.h> 27470decc6SDave Kleikamp #include <linux/highmem.h> 28e07f7183SJosef Bacik #include <linux/hrtimer.h> 2947def826STheodore Ts'o #include <linux/backing-dev.h> 3047def826STheodore Ts'o #include <linux/module.h> 31470decc6SDave Kleikamp 327ddae860SAdrian Bunk static void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh); 337ddae860SAdrian Bunk 34470decc6SDave Kleikamp /* 35f7f4bccbSMingming Cao * jbd2_get_transaction: obtain a new transaction_t object. 36470decc6SDave Kleikamp * 37470decc6SDave Kleikamp * Simply allocate and initialise a new transaction. Create it in 38470decc6SDave Kleikamp * RUNNING state and add it to the current journal (which should not 39470decc6SDave Kleikamp * have an existing running transaction: we only make a new transaction 40470decc6SDave Kleikamp * once we have started to commit the old one). 41470decc6SDave Kleikamp * 42470decc6SDave Kleikamp * Preconditions: 43470decc6SDave Kleikamp * The journal MUST be locked. We don't perform atomic mallocs on the 44470decc6SDave Kleikamp * new transaction and we can't block without protecting against other 45470decc6SDave Kleikamp * processes trying to touch the journal while it is in transition. 46470decc6SDave Kleikamp * 47470decc6SDave Kleikamp */ 48470decc6SDave Kleikamp 49470decc6SDave Kleikamp static transaction_t * 50f7f4bccbSMingming Cao jbd2_get_transaction(journal_t *journal, transaction_t *transaction) 51470decc6SDave Kleikamp { 52470decc6SDave Kleikamp transaction->t_journal = journal; 53470decc6SDave Kleikamp transaction->t_state = T_RUNNING; 54e07f7183SJosef Bacik transaction->t_start_time = ktime_get(); 55470decc6SDave Kleikamp transaction->t_tid = journal->j_transaction_sequence++; 56470decc6SDave Kleikamp transaction->t_expires = jiffies + journal->j_commit_interval; 57470decc6SDave Kleikamp spin_lock_init(&transaction->t_handle_lock); 58a51dca9cSTheodore Ts'o atomic_set(&transaction->t_updates, 0); 59a51dca9cSTheodore Ts'o atomic_set(&transaction->t_outstanding_credits, 0); 608dd42046STheodore Ts'o atomic_set(&transaction->t_handle_count, 0); 61c851ed54SJan Kara INIT_LIST_HEAD(&transaction->t_inode_list); 623e624fc7STheodore Ts'o INIT_LIST_HEAD(&transaction->t_private_list); 63470decc6SDave Kleikamp 64470decc6SDave Kleikamp /* Set up the commit timer for the new transaction. */ 65b1f485f2SAndreas Dilger journal->j_commit_timer.expires = round_jiffies_up(transaction->t_expires); 66470decc6SDave Kleikamp add_timer(&journal->j_commit_timer); 67470decc6SDave Kleikamp 68470decc6SDave Kleikamp J_ASSERT(journal->j_running_transaction == NULL); 69470decc6SDave Kleikamp journal->j_running_transaction = transaction; 708e85fb3fSJohann Lombardi transaction->t_max_wait = 0; 718e85fb3fSJohann Lombardi transaction->t_start = jiffies; 72470decc6SDave Kleikamp 73470decc6SDave Kleikamp return transaction; 74470decc6SDave Kleikamp } 75470decc6SDave Kleikamp 76470decc6SDave Kleikamp /* 77470decc6SDave Kleikamp * Handle management. 78470decc6SDave Kleikamp * 79470decc6SDave Kleikamp * A handle_t is an object which represents a single atomic update to a 80470decc6SDave Kleikamp * filesystem, and which tracks all of the modifications which form part 81470decc6SDave Kleikamp * of that one update. 82470decc6SDave Kleikamp */ 83470decc6SDave Kleikamp 84470decc6SDave Kleikamp /* 856d0bf005STheodore Ts'o * Update transiaction's maximum wait time, if debugging is enabled. 866d0bf005STheodore Ts'o * 876d0bf005STheodore Ts'o * In order for t_max_wait to be reliable, it must be protected by a 886d0bf005STheodore Ts'o * lock. But doing so will mean that start_this_handle() can not be 896d0bf005STheodore Ts'o * run in parallel on SMP systems, which limits our scalability. So 906d0bf005STheodore Ts'o * unless debugging is enabled, we no longer update t_max_wait, which 916d0bf005STheodore Ts'o * means that maximum wait time reported by the jbd2_run_stats 926d0bf005STheodore Ts'o * tracepoint will always be zero. 936d0bf005STheodore Ts'o */ 946d0bf005STheodore Ts'o static inline void update_t_max_wait(transaction_t *transaction) 956d0bf005STheodore Ts'o { 966d0bf005STheodore Ts'o #ifdef CONFIG_JBD2_DEBUG 976d0bf005STheodore Ts'o unsigned long ts = jiffies; 986d0bf005STheodore Ts'o 996d0bf005STheodore Ts'o if (jbd2_journal_enable_debug && 1006d0bf005STheodore Ts'o time_after(transaction->t_start, ts)) { 1016d0bf005STheodore Ts'o ts = jbd2_time_diff(ts, transaction->t_start); 1026d0bf005STheodore Ts'o spin_lock(&transaction->t_handle_lock); 1036d0bf005STheodore Ts'o if (ts > transaction->t_max_wait) 1046d0bf005STheodore Ts'o transaction->t_max_wait = ts; 1056d0bf005STheodore Ts'o spin_unlock(&transaction->t_handle_lock); 1066d0bf005STheodore Ts'o } 1076d0bf005STheodore Ts'o #endif 1086d0bf005STheodore Ts'o } 1096d0bf005STheodore Ts'o 1106d0bf005STheodore Ts'o /* 111470decc6SDave Kleikamp * start_this_handle: Given a handle, deal with any locking or stalling 112470decc6SDave Kleikamp * needed to make sure that there is enough journal space for the handle 113470decc6SDave Kleikamp * to begin. Attach the handle to a transaction and set up the 114470decc6SDave Kleikamp * transaction's buffer credits. 115470decc6SDave Kleikamp */ 116470decc6SDave Kleikamp 11747def826STheodore Ts'o static int start_this_handle(journal_t *journal, handle_t *handle, 11847def826STheodore Ts'o int gfp_mask) 119470decc6SDave Kleikamp { 120470decc6SDave Kleikamp transaction_t *transaction; 121470decc6SDave Kleikamp int needed; 122470decc6SDave Kleikamp int nblocks = handle->h_buffer_credits; 123470decc6SDave Kleikamp transaction_t *new_transaction = NULL; 124470decc6SDave Kleikamp 125470decc6SDave Kleikamp if (nblocks > journal->j_max_transaction_buffers) { 126470decc6SDave Kleikamp printk(KERN_ERR "JBD: %s wants too many credits (%d > %d)\n", 127470decc6SDave Kleikamp current->comm, nblocks, 128470decc6SDave Kleikamp journal->j_max_transaction_buffers); 12947def826STheodore Ts'o return -ENOSPC; 130470decc6SDave Kleikamp } 131470decc6SDave Kleikamp 132470decc6SDave Kleikamp alloc_transaction: 133470decc6SDave Kleikamp if (!journal->j_running_transaction) { 13447def826STheodore Ts'o new_transaction = kzalloc(sizeof(*new_transaction), gfp_mask); 135470decc6SDave Kleikamp if (!new_transaction) { 13647def826STheodore Ts'o /* 13747def826STheodore Ts'o * If __GFP_FS is not present, then we may be 13847def826STheodore Ts'o * being called from inside the fs writeback 13947def826STheodore Ts'o * layer, so we MUST NOT fail. Since 14047def826STheodore Ts'o * __GFP_NOFAIL is going away, we will arrange 14147def826STheodore Ts'o * to retry the allocation ourselves. 14247def826STheodore Ts'o */ 14347def826STheodore Ts'o if ((gfp_mask & __GFP_FS) == 0) { 14447def826STheodore Ts'o congestion_wait(BLK_RW_ASYNC, HZ/50); 14547def826STheodore Ts'o goto alloc_transaction; 14647def826STheodore Ts'o } 14747def826STheodore Ts'o return -ENOMEM; 148470decc6SDave Kleikamp } 149470decc6SDave Kleikamp } 150470decc6SDave Kleikamp 151470decc6SDave Kleikamp jbd_debug(3, "New handle %p going live.\n", handle); 152470decc6SDave Kleikamp 153470decc6SDave Kleikamp /* 154470decc6SDave Kleikamp * We need to hold j_state_lock until t_updates has been incremented, 155470decc6SDave Kleikamp * for proper journal barrier handling 156470decc6SDave Kleikamp */ 157a931da6aSTheodore Ts'o repeat: 158a931da6aSTheodore Ts'o read_lock(&journal->j_state_lock); 1595c2178e7STheodore Ts'o BUG_ON(journal->j_flags & JBD2_UNMOUNT); 160470decc6SDave Kleikamp if (is_journal_aborted(journal) || 161f7f4bccbSMingming Cao (journal->j_errno != 0 && !(journal->j_flags & JBD2_ACK_ERR))) { 162a931da6aSTheodore Ts'o read_unlock(&journal->j_state_lock); 16347def826STheodore Ts'o kfree(new_transaction); 16447def826STheodore Ts'o return -EROFS; 165470decc6SDave Kleikamp } 166470decc6SDave Kleikamp 167470decc6SDave Kleikamp /* Wait on the journal's transaction barrier if necessary */ 168470decc6SDave Kleikamp if (journal->j_barrier_count) { 169a931da6aSTheodore Ts'o read_unlock(&journal->j_state_lock); 170470decc6SDave Kleikamp wait_event(journal->j_wait_transaction_locked, 171470decc6SDave Kleikamp journal->j_barrier_count == 0); 172470decc6SDave Kleikamp goto repeat; 173470decc6SDave Kleikamp } 174470decc6SDave Kleikamp 175470decc6SDave Kleikamp if (!journal->j_running_transaction) { 176a931da6aSTheodore Ts'o read_unlock(&journal->j_state_lock); 177a931da6aSTheodore Ts'o if (!new_transaction) 178470decc6SDave Kleikamp goto alloc_transaction; 179a931da6aSTheodore Ts'o write_lock(&journal->j_state_lock); 180a931da6aSTheodore Ts'o if (!journal->j_running_transaction) { 181f7f4bccbSMingming Cao jbd2_get_transaction(journal, new_transaction); 182470decc6SDave Kleikamp new_transaction = NULL; 183470decc6SDave Kleikamp } 184a931da6aSTheodore Ts'o write_unlock(&journal->j_state_lock); 185a931da6aSTheodore Ts'o goto repeat; 186a931da6aSTheodore Ts'o } 187470decc6SDave Kleikamp 188470decc6SDave Kleikamp transaction = journal->j_running_transaction; 189470decc6SDave Kleikamp 190470decc6SDave Kleikamp /* 191470decc6SDave Kleikamp * If the current transaction is locked down for commit, wait for the 192470decc6SDave Kleikamp * lock to be released. 193470decc6SDave Kleikamp */ 194470decc6SDave Kleikamp if (transaction->t_state == T_LOCKED) { 195470decc6SDave Kleikamp DEFINE_WAIT(wait); 196470decc6SDave Kleikamp 197470decc6SDave Kleikamp prepare_to_wait(&journal->j_wait_transaction_locked, 198470decc6SDave Kleikamp &wait, TASK_UNINTERRUPTIBLE); 199a931da6aSTheodore Ts'o read_unlock(&journal->j_state_lock); 200470decc6SDave Kleikamp schedule(); 201470decc6SDave Kleikamp finish_wait(&journal->j_wait_transaction_locked, &wait); 202470decc6SDave Kleikamp goto repeat; 203470decc6SDave Kleikamp } 204470decc6SDave Kleikamp 205470decc6SDave Kleikamp /* 206470decc6SDave Kleikamp * If there is not enough space left in the log to write all potential 207470decc6SDave Kleikamp * buffers requested by this operation, we need to stall pending a log 208470decc6SDave Kleikamp * checkpoint to free some more log space. 209470decc6SDave Kleikamp */ 2108dd42046STheodore Ts'o needed = atomic_add_return(nblocks, 2118dd42046STheodore Ts'o &transaction->t_outstanding_credits); 212470decc6SDave Kleikamp 213470decc6SDave Kleikamp if (needed > journal->j_max_transaction_buffers) { 214470decc6SDave Kleikamp /* 215470decc6SDave Kleikamp * If the current transaction is already too large, then start 216470decc6SDave Kleikamp * to commit it: we can then go back and attach this handle to 217470decc6SDave Kleikamp * a new transaction. 218470decc6SDave Kleikamp */ 219470decc6SDave Kleikamp DEFINE_WAIT(wait); 220470decc6SDave Kleikamp 221470decc6SDave Kleikamp jbd_debug(2, "Handle %p starting new commit...\n", handle); 2228dd42046STheodore Ts'o atomic_sub(nblocks, &transaction->t_outstanding_credits); 223470decc6SDave Kleikamp prepare_to_wait(&journal->j_wait_transaction_locked, &wait, 224470decc6SDave Kleikamp TASK_UNINTERRUPTIBLE); 225f7f4bccbSMingming Cao __jbd2_log_start_commit(journal, transaction->t_tid); 226a931da6aSTheodore Ts'o read_unlock(&journal->j_state_lock); 227470decc6SDave Kleikamp schedule(); 228470decc6SDave Kleikamp finish_wait(&journal->j_wait_transaction_locked, &wait); 229470decc6SDave Kleikamp goto repeat; 230470decc6SDave Kleikamp } 231470decc6SDave Kleikamp 232470decc6SDave Kleikamp /* 233470decc6SDave Kleikamp * The commit code assumes that it can get enough log space 234470decc6SDave Kleikamp * without forcing a checkpoint. This is *critical* for 235470decc6SDave Kleikamp * correctness: a checkpoint of a buffer which is also 236470decc6SDave Kleikamp * associated with a committing transaction creates a deadlock, 237470decc6SDave Kleikamp * so commit simply cannot force through checkpoints. 238470decc6SDave Kleikamp * 239470decc6SDave Kleikamp * We must therefore ensure the necessary space in the journal 240470decc6SDave Kleikamp * *before* starting to dirty potentially checkpointed buffers 241470decc6SDave Kleikamp * in the new transaction. 242470decc6SDave Kleikamp * 243470decc6SDave Kleikamp * The worst part is, any transaction currently committing can 244470decc6SDave Kleikamp * reduce the free space arbitrarily. Be careful to account for 245470decc6SDave Kleikamp * those buffers when checkpointing. 246470decc6SDave Kleikamp */ 247470decc6SDave Kleikamp 248470decc6SDave Kleikamp /* 249470decc6SDave Kleikamp * @@@ AKPM: This seems rather over-defensive. We're giving commit 250470decc6SDave Kleikamp * a _lot_ of headroom: 1/4 of the journal plus the size of 251470decc6SDave Kleikamp * the committing transaction. Really, we only need to give it 252470decc6SDave Kleikamp * committing_transaction->t_outstanding_credits plus "enough" for 253470decc6SDave Kleikamp * the log control blocks. 254470decc6SDave Kleikamp * Also, this test is inconsitent with the matching one in 255f7f4bccbSMingming Cao * jbd2_journal_extend(). 256470decc6SDave Kleikamp */ 257f7f4bccbSMingming Cao if (__jbd2_log_space_left(journal) < jbd_space_needed(journal)) { 258470decc6SDave Kleikamp jbd_debug(2, "Handle %p waiting for checkpoint...\n", handle); 2598dd42046STheodore Ts'o atomic_sub(nblocks, &transaction->t_outstanding_credits); 260a931da6aSTheodore Ts'o read_unlock(&journal->j_state_lock); 261a931da6aSTheodore Ts'o write_lock(&journal->j_state_lock); 262a931da6aSTheodore Ts'o if (__jbd2_log_space_left(journal) < jbd_space_needed(journal)) 263f7f4bccbSMingming Cao __jbd2_log_wait_for_space(journal); 264a931da6aSTheodore Ts'o write_unlock(&journal->j_state_lock); 265a931da6aSTheodore Ts'o goto repeat; 266470decc6SDave Kleikamp } 267470decc6SDave Kleikamp 268470decc6SDave Kleikamp /* OK, account for the buffers that this operation expects to 2698dd42046STheodore Ts'o * use and add the handle to the running transaction. 2708dd42046STheodore Ts'o */ 2716d0bf005STheodore Ts'o update_t_max_wait(transaction); 272470decc6SDave Kleikamp handle->h_transaction = transaction; 273a51dca9cSTheodore Ts'o atomic_inc(&transaction->t_updates); 2748dd42046STheodore Ts'o atomic_inc(&transaction->t_handle_count); 275470decc6SDave Kleikamp jbd_debug(4, "Handle %p given %d credits (total %d, free %d)\n", 276a51dca9cSTheodore Ts'o handle, nblocks, 277a51dca9cSTheodore Ts'o atomic_read(&transaction->t_outstanding_credits), 278f7f4bccbSMingming Cao __jbd2_log_space_left(journal)); 279a931da6aSTheodore Ts'o read_unlock(&journal->j_state_lock); 2809599b0e5SJan Kara 2819599b0e5SJan Kara lock_map_acquire(&handle->h_lockdep_map); 282470decc6SDave Kleikamp kfree(new_transaction); 28347def826STheodore Ts'o return 0; 284470decc6SDave Kleikamp } 285470decc6SDave Kleikamp 2867b751066SMingming Cao static struct lock_class_key jbd2_handle_key; 2877b751066SMingming Cao 288470decc6SDave Kleikamp /* Allocate a new handle. This should probably be in a slab... */ 289470decc6SDave Kleikamp static handle_t *new_handle(int nblocks) 290470decc6SDave Kleikamp { 291af1e76d6SMingming Cao handle_t *handle = jbd2_alloc_handle(GFP_NOFS); 292470decc6SDave Kleikamp if (!handle) 293470decc6SDave Kleikamp return NULL; 294470decc6SDave Kleikamp memset(handle, 0, sizeof(*handle)); 295470decc6SDave Kleikamp handle->h_buffer_credits = nblocks; 296470decc6SDave Kleikamp handle->h_ref = 1; 297470decc6SDave Kleikamp 2987b751066SMingming Cao lockdep_init_map(&handle->h_lockdep_map, "jbd2_handle", 2997b751066SMingming Cao &jbd2_handle_key, 0); 3007b751066SMingming Cao 301470decc6SDave Kleikamp return handle; 302470decc6SDave Kleikamp } 303470decc6SDave Kleikamp 304470decc6SDave Kleikamp /** 305f7f4bccbSMingming Cao * handle_t *jbd2_journal_start() - Obtain a new handle. 306470decc6SDave Kleikamp * @journal: Journal to start transaction on. 307470decc6SDave Kleikamp * @nblocks: number of block buffer we might modify 308470decc6SDave Kleikamp * 309470decc6SDave Kleikamp * We make sure that the transaction can guarantee at least nblocks of 310470decc6SDave Kleikamp * modified buffers in the log. We block until the log can guarantee 311470decc6SDave Kleikamp * that much space. 312470decc6SDave Kleikamp * 313470decc6SDave Kleikamp * This function is visible to journal users (like ext3fs), so is not 314470decc6SDave Kleikamp * called with the journal already locked. 315470decc6SDave Kleikamp * 316470decc6SDave Kleikamp * Return a pointer to a newly allocated handle, or NULL on failure 317470decc6SDave Kleikamp */ 31847def826STheodore Ts'o handle_t *jbd2__journal_start(journal_t *journal, int nblocks, int gfp_mask) 319470decc6SDave Kleikamp { 320470decc6SDave Kleikamp handle_t *handle = journal_current_handle(); 321470decc6SDave Kleikamp int err; 322470decc6SDave Kleikamp 323470decc6SDave Kleikamp if (!journal) 324470decc6SDave Kleikamp return ERR_PTR(-EROFS); 325470decc6SDave Kleikamp 326470decc6SDave Kleikamp if (handle) { 327470decc6SDave Kleikamp J_ASSERT(handle->h_transaction->t_journal == journal); 328470decc6SDave Kleikamp handle->h_ref++; 329470decc6SDave Kleikamp return handle; 330470decc6SDave Kleikamp } 331470decc6SDave Kleikamp 332470decc6SDave Kleikamp handle = new_handle(nblocks); 333470decc6SDave Kleikamp if (!handle) 334470decc6SDave Kleikamp return ERR_PTR(-ENOMEM); 335470decc6SDave Kleikamp 336470decc6SDave Kleikamp current->journal_info = handle; 337470decc6SDave Kleikamp 33847def826STheodore Ts'o err = start_this_handle(journal, handle, gfp_mask); 339470decc6SDave Kleikamp if (err < 0) { 340af1e76d6SMingming Cao jbd2_free_handle(handle); 341470decc6SDave Kleikamp current->journal_info = NULL; 342470decc6SDave Kleikamp handle = ERR_PTR(err); 3437b751066SMingming Cao goto out; 344470decc6SDave Kleikamp } 3457b751066SMingming Cao out: 346470decc6SDave Kleikamp return handle; 347470decc6SDave Kleikamp } 34847def826STheodore Ts'o EXPORT_SYMBOL(jbd2__journal_start); 34947def826STheodore Ts'o 35047def826STheodore Ts'o 35147def826STheodore Ts'o handle_t *jbd2_journal_start(journal_t *journal, int nblocks) 35247def826STheodore Ts'o { 35347def826STheodore Ts'o return jbd2__journal_start(journal, nblocks, GFP_NOFS); 35447def826STheodore Ts'o } 35547def826STheodore Ts'o EXPORT_SYMBOL(jbd2_journal_start); 35647def826STheodore Ts'o 357470decc6SDave Kleikamp 358470decc6SDave Kleikamp /** 359f7f4bccbSMingming Cao * int jbd2_journal_extend() - extend buffer credits. 360470decc6SDave Kleikamp * @handle: handle to 'extend' 361470decc6SDave Kleikamp * @nblocks: nr blocks to try to extend by. 362470decc6SDave Kleikamp * 363470decc6SDave Kleikamp * Some transactions, such as large extends and truncates, can be done 364470decc6SDave Kleikamp * atomically all at once or in several stages. The operation requests 365470decc6SDave Kleikamp * a credit for a number of buffer modications in advance, but can 366470decc6SDave Kleikamp * extend its credit if it needs more. 367470decc6SDave Kleikamp * 368f7f4bccbSMingming Cao * jbd2_journal_extend tries to give the running handle more buffer credits. 369470decc6SDave Kleikamp * It does not guarantee that allocation - this is a best-effort only. 370470decc6SDave Kleikamp * The calling process MUST be able to deal cleanly with a failure to 371470decc6SDave Kleikamp * extend here. 372470decc6SDave Kleikamp * 373470decc6SDave Kleikamp * Return 0 on success, non-zero on failure. 374470decc6SDave Kleikamp * 375470decc6SDave Kleikamp * return code < 0 implies an error 376470decc6SDave Kleikamp * return code > 0 implies normal transaction-full status. 377470decc6SDave Kleikamp */ 378f7f4bccbSMingming Cao int jbd2_journal_extend(handle_t *handle, int nblocks) 379470decc6SDave Kleikamp { 380470decc6SDave Kleikamp transaction_t *transaction = handle->h_transaction; 381470decc6SDave Kleikamp journal_t *journal = transaction->t_journal; 382470decc6SDave Kleikamp int result; 383470decc6SDave Kleikamp int wanted; 384470decc6SDave Kleikamp 385470decc6SDave Kleikamp result = -EIO; 386470decc6SDave Kleikamp if (is_handle_aborted(handle)) 387470decc6SDave Kleikamp goto out; 388470decc6SDave Kleikamp 389470decc6SDave Kleikamp result = 1; 390470decc6SDave Kleikamp 391a931da6aSTheodore Ts'o read_lock(&journal->j_state_lock); 392470decc6SDave Kleikamp 393470decc6SDave Kleikamp /* Don't extend a locked-down transaction! */ 394470decc6SDave Kleikamp if (handle->h_transaction->t_state != T_RUNNING) { 395470decc6SDave Kleikamp jbd_debug(3, "denied handle %p %d blocks: " 396470decc6SDave Kleikamp "transaction not running\n", handle, nblocks); 397470decc6SDave Kleikamp goto error_out; 398470decc6SDave Kleikamp } 399470decc6SDave Kleikamp 400470decc6SDave Kleikamp spin_lock(&transaction->t_handle_lock); 401a51dca9cSTheodore Ts'o wanted = atomic_read(&transaction->t_outstanding_credits) + nblocks; 402470decc6SDave Kleikamp 403470decc6SDave Kleikamp if (wanted > journal->j_max_transaction_buffers) { 404470decc6SDave Kleikamp jbd_debug(3, "denied handle %p %d blocks: " 405470decc6SDave Kleikamp "transaction too large\n", handle, nblocks); 406470decc6SDave Kleikamp goto unlock; 407470decc6SDave Kleikamp } 408470decc6SDave Kleikamp 409f7f4bccbSMingming Cao if (wanted > __jbd2_log_space_left(journal)) { 410470decc6SDave Kleikamp jbd_debug(3, "denied handle %p %d blocks: " 411470decc6SDave Kleikamp "insufficient log space\n", handle, nblocks); 412470decc6SDave Kleikamp goto unlock; 413470decc6SDave Kleikamp } 414470decc6SDave Kleikamp 415470decc6SDave Kleikamp handle->h_buffer_credits += nblocks; 416a51dca9cSTheodore Ts'o atomic_add(nblocks, &transaction->t_outstanding_credits); 417470decc6SDave Kleikamp result = 0; 418470decc6SDave Kleikamp 419470decc6SDave Kleikamp jbd_debug(3, "extended handle %p by %d\n", handle, nblocks); 420470decc6SDave Kleikamp unlock: 421470decc6SDave Kleikamp spin_unlock(&transaction->t_handle_lock); 422470decc6SDave Kleikamp error_out: 423a931da6aSTheodore Ts'o read_unlock(&journal->j_state_lock); 424470decc6SDave Kleikamp out: 425470decc6SDave Kleikamp return result; 426470decc6SDave Kleikamp } 427470decc6SDave Kleikamp 428470decc6SDave Kleikamp 429470decc6SDave Kleikamp /** 430f7f4bccbSMingming Cao * int jbd2_journal_restart() - restart a handle . 431470decc6SDave Kleikamp * @handle: handle to restart 432470decc6SDave Kleikamp * @nblocks: nr credits requested 433470decc6SDave Kleikamp * 434470decc6SDave Kleikamp * Restart a handle for a multi-transaction filesystem 435470decc6SDave Kleikamp * operation. 436470decc6SDave Kleikamp * 437f7f4bccbSMingming Cao * If the jbd2_journal_extend() call above fails to grant new buffer credits 438f7f4bccbSMingming Cao * to a running handle, a call to jbd2_journal_restart will commit the 439470decc6SDave Kleikamp * handle's transaction so far and reattach the handle to a new 440470decc6SDave Kleikamp * transaction capabable of guaranteeing the requested number of 441470decc6SDave Kleikamp * credits. 442470decc6SDave Kleikamp */ 44347def826STheodore Ts'o int jbd2__journal_restart(handle_t *handle, int nblocks, int gfp_mask) 444470decc6SDave Kleikamp { 445470decc6SDave Kleikamp transaction_t *transaction = handle->h_transaction; 446470decc6SDave Kleikamp journal_t *journal = transaction->t_journal; 447470decc6SDave Kleikamp int ret; 448470decc6SDave Kleikamp 449470decc6SDave Kleikamp /* If we've had an abort of any type, don't even think about 450470decc6SDave Kleikamp * actually doing the restart! */ 451470decc6SDave Kleikamp if (is_handle_aborted(handle)) 452470decc6SDave Kleikamp return 0; 453470decc6SDave Kleikamp 454470decc6SDave Kleikamp /* 455470decc6SDave Kleikamp * First unlink the handle from its current transaction, and start the 456470decc6SDave Kleikamp * commit on that. 457470decc6SDave Kleikamp */ 458a51dca9cSTheodore Ts'o J_ASSERT(atomic_read(&transaction->t_updates) > 0); 459470decc6SDave Kleikamp J_ASSERT(journal_current_handle() == handle); 460470decc6SDave Kleikamp 461a931da6aSTheodore Ts'o read_lock(&journal->j_state_lock); 462470decc6SDave Kleikamp spin_lock(&transaction->t_handle_lock); 463a51dca9cSTheodore Ts'o atomic_sub(handle->h_buffer_credits, 464a51dca9cSTheodore Ts'o &transaction->t_outstanding_credits); 465a51dca9cSTheodore Ts'o if (atomic_dec_and_test(&transaction->t_updates)) 466470decc6SDave Kleikamp wake_up(&journal->j_wait_updates); 467470decc6SDave Kleikamp spin_unlock(&transaction->t_handle_lock); 468470decc6SDave Kleikamp 469470decc6SDave Kleikamp jbd_debug(2, "restarting handle %p\n", handle); 470f7f4bccbSMingming Cao __jbd2_log_start_commit(journal, transaction->t_tid); 471a931da6aSTheodore Ts'o read_unlock(&journal->j_state_lock); 472470decc6SDave Kleikamp 4739599b0e5SJan Kara lock_map_release(&handle->h_lockdep_map); 474470decc6SDave Kleikamp handle->h_buffer_credits = nblocks; 47547def826STheodore Ts'o ret = start_this_handle(journal, handle, gfp_mask); 476470decc6SDave Kleikamp return ret; 477470decc6SDave Kleikamp } 47847def826STheodore Ts'o EXPORT_SYMBOL(jbd2__journal_restart); 479470decc6SDave Kleikamp 480470decc6SDave Kleikamp 48147def826STheodore Ts'o int jbd2_journal_restart(handle_t *handle, int nblocks) 48247def826STheodore Ts'o { 48347def826STheodore Ts'o return jbd2__journal_restart(handle, nblocks, GFP_NOFS); 48447def826STheodore Ts'o } 48547def826STheodore Ts'o EXPORT_SYMBOL(jbd2_journal_restart); 48647def826STheodore Ts'o 487470decc6SDave Kleikamp /** 488f7f4bccbSMingming Cao * void jbd2_journal_lock_updates () - establish a transaction barrier. 489470decc6SDave Kleikamp * @journal: Journal to establish a barrier on. 490470decc6SDave Kleikamp * 491470decc6SDave Kleikamp * This locks out any further updates from being started, and blocks 492470decc6SDave Kleikamp * until all existing updates have completed, returning only once the 493470decc6SDave Kleikamp * journal is in a quiescent state with no updates running. 494470decc6SDave Kleikamp * 495470decc6SDave Kleikamp * The journal lock should not be held on entry. 496470decc6SDave Kleikamp */ 497f7f4bccbSMingming Cao void jbd2_journal_lock_updates(journal_t *journal) 498470decc6SDave Kleikamp { 499470decc6SDave Kleikamp DEFINE_WAIT(wait); 500470decc6SDave Kleikamp 501a931da6aSTheodore Ts'o write_lock(&journal->j_state_lock); 502470decc6SDave Kleikamp ++journal->j_barrier_count; 503470decc6SDave Kleikamp 504470decc6SDave Kleikamp /* Wait until there are no running updates */ 505470decc6SDave Kleikamp while (1) { 506470decc6SDave Kleikamp transaction_t *transaction = journal->j_running_transaction; 507470decc6SDave Kleikamp 508470decc6SDave Kleikamp if (!transaction) 509470decc6SDave Kleikamp break; 510470decc6SDave Kleikamp 511470decc6SDave Kleikamp spin_lock(&transaction->t_handle_lock); 512a51dca9cSTheodore Ts'o if (!atomic_read(&transaction->t_updates)) { 513470decc6SDave Kleikamp spin_unlock(&transaction->t_handle_lock); 514470decc6SDave Kleikamp break; 515470decc6SDave Kleikamp } 516470decc6SDave Kleikamp prepare_to_wait(&journal->j_wait_updates, &wait, 517470decc6SDave Kleikamp TASK_UNINTERRUPTIBLE); 518470decc6SDave Kleikamp spin_unlock(&transaction->t_handle_lock); 519a931da6aSTheodore Ts'o write_unlock(&journal->j_state_lock); 520470decc6SDave Kleikamp schedule(); 521470decc6SDave Kleikamp finish_wait(&journal->j_wait_updates, &wait); 522a931da6aSTheodore Ts'o write_lock(&journal->j_state_lock); 523470decc6SDave Kleikamp } 524a931da6aSTheodore Ts'o write_unlock(&journal->j_state_lock); 525470decc6SDave Kleikamp 526470decc6SDave Kleikamp /* 527470decc6SDave Kleikamp * We have now established a barrier against other normal updates, but 528f7f4bccbSMingming Cao * we also need to barrier against other jbd2_journal_lock_updates() calls 529470decc6SDave Kleikamp * to make sure that we serialise special journal-locked operations 530470decc6SDave Kleikamp * too. 531470decc6SDave Kleikamp */ 532470decc6SDave Kleikamp mutex_lock(&journal->j_barrier); 533470decc6SDave Kleikamp } 534470decc6SDave Kleikamp 535470decc6SDave Kleikamp /** 536f7f4bccbSMingming Cao * void jbd2_journal_unlock_updates (journal_t* journal) - release barrier 537470decc6SDave Kleikamp * @journal: Journal to release the barrier on. 538470decc6SDave Kleikamp * 539f7f4bccbSMingming Cao * Release a transaction barrier obtained with jbd2_journal_lock_updates(). 540470decc6SDave Kleikamp * 541470decc6SDave Kleikamp * Should be called without the journal lock held. 542470decc6SDave Kleikamp */ 543f7f4bccbSMingming Cao void jbd2_journal_unlock_updates (journal_t *journal) 544470decc6SDave Kleikamp { 545470decc6SDave Kleikamp J_ASSERT(journal->j_barrier_count != 0); 546470decc6SDave Kleikamp 547470decc6SDave Kleikamp mutex_unlock(&journal->j_barrier); 548a931da6aSTheodore Ts'o write_lock(&journal->j_state_lock); 549470decc6SDave Kleikamp --journal->j_barrier_count; 550a931da6aSTheodore Ts'o write_unlock(&journal->j_state_lock); 551470decc6SDave Kleikamp wake_up(&journal->j_wait_transaction_locked); 552470decc6SDave Kleikamp } 553470decc6SDave Kleikamp 554f91d1d04SJan Kara static void warn_dirty_buffer(struct buffer_head *bh) 555470decc6SDave Kleikamp { 556f91d1d04SJan Kara char b[BDEVNAME_SIZE]; 557470decc6SDave Kleikamp 558f91d1d04SJan Kara printk(KERN_WARNING 559f91d1d04SJan Kara "JBD: Spotted dirty metadata buffer (dev = %s, blocknr = %llu). " 560f91d1d04SJan Kara "There's a risk of filesystem corruption in case of system " 561f91d1d04SJan Kara "crash.\n", 562f91d1d04SJan Kara bdevname(bh->b_bdev, b), (unsigned long long)bh->b_blocknr); 563470decc6SDave Kleikamp } 564470decc6SDave Kleikamp 565470decc6SDave Kleikamp /* 566470decc6SDave Kleikamp * If the buffer is already part of the current transaction, then there 567470decc6SDave Kleikamp * is nothing we need to do. If it is already part of a prior 568470decc6SDave Kleikamp * transaction which we are still committing to disk, then we need to 569470decc6SDave Kleikamp * make sure that we do not overwrite the old copy: we do copy-out to 570470decc6SDave Kleikamp * preserve the copy going to disk. We also account the buffer against 571470decc6SDave Kleikamp * the handle's metadata buffer credits (unless the buffer is already 572470decc6SDave Kleikamp * part of the transaction, that is). 573470decc6SDave Kleikamp * 574470decc6SDave Kleikamp */ 575470decc6SDave Kleikamp static int 576470decc6SDave Kleikamp do_get_write_access(handle_t *handle, struct journal_head *jh, 577470decc6SDave Kleikamp int force_copy) 578470decc6SDave Kleikamp { 579470decc6SDave Kleikamp struct buffer_head *bh; 580470decc6SDave Kleikamp transaction_t *transaction; 581470decc6SDave Kleikamp journal_t *journal; 582470decc6SDave Kleikamp int error; 583470decc6SDave Kleikamp char *frozen_buffer = NULL; 584470decc6SDave Kleikamp int need_copy = 0; 585470decc6SDave Kleikamp 586470decc6SDave Kleikamp if (is_handle_aborted(handle)) 587470decc6SDave Kleikamp return -EROFS; 588470decc6SDave Kleikamp 589470decc6SDave Kleikamp transaction = handle->h_transaction; 590470decc6SDave Kleikamp journal = transaction->t_journal; 591470decc6SDave Kleikamp 592470decc6SDave Kleikamp jbd_debug(5, "buffer_head %p, force_copy %d\n", jh, force_copy); 593470decc6SDave Kleikamp 594470decc6SDave Kleikamp JBUFFER_TRACE(jh, "entry"); 595470decc6SDave Kleikamp repeat: 596470decc6SDave Kleikamp bh = jh2bh(jh); 597470decc6SDave Kleikamp 598470decc6SDave Kleikamp /* @@@ Need to check for errors here at some point. */ 599470decc6SDave Kleikamp 600470decc6SDave Kleikamp lock_buffer(bh); 601470decc6SDave Kleikamp jbd_lock_bh_state(bh); 602470decc6SDave Kleikamp 603470decc6SDave Kleikamp /* We now hold the buffer lock so it is safe to query the buffer 604470decc6SDave Kleikamp * state. Is the buffer dirty? 605470decc6SDave Kleikamp * 606470decc6SDave Kleikamp * If so, there are two possibilities. The buffer may be 607470decc6SDave Kleikamp * non-journaled, and undergoing a quite legitimate writeback. 608470decc6SDave Kleikamp * Otherwise, it is journaled, and we don't expect dirty buffers 609470decc6SDave Kleikamp * in that state (the buffers should be marked JBD_Dirty 610470decc6SDave Kleikamp * instead.) So either the IO is being done under our own 611470decc6SDave Kleikamp * control and this is a bug, or it's a third party IO such as 612470decc6SDave Kleikamp * dump(8) (which may leave the buffer scheduled for read --- 613470decc6SDave Kleikamp * ie. locked but not dirty) or tune2fs (which may actually have 614470decc6SDave Kleikamp * the buffer dirtied, ugh.) */ 615470decc6SDave Kleikamp 616470decc6SDave Kleikamp if (buffer_dirty(bh)) { 617470decc6SDave Kleikamp /* 618470decc6SDave Kleikamp * First question: is this buffer already part of the current 619470decc6SDave Kleikamp * transaction or the existing committing transaction? 620470decc6SDave Kleikamp */ 621470decc6SDave Kleikamp if (jh->b_transaction) { 622470decc6SDave Kleikamp J_ASSERT_JH(jh, 623470decc6SDave Kleikamp jh->b_transaction == transaction || 624470decc6SDave Kleikamp jh->b_transaction == 625470decc6SDave Kleikamp journal->j_committing_transaction); 626470decc6SDave Kleikamp if (jh->b_next_transaction) 627470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_next_transaction == 628470decc6SDave Kleikamp transaction); 629f91d1d04SJan Kara warn_dirty_buffer(bh); 630470decc6SDave Kleikamp } 631470decc6SDave Kleikamp /* 632470decc6SDave Kleikamp * In any case we need to clean the dirty flag and we must 633470decc6SDave Kleikamp * do it under the buffer lock to be sure we don't race 634470decc6SDave Kleikamp * with running write-out. 635470decc6SDave Kleikamp */ 636f91d1d04SJan Kara JBUFFER_TRACE(jh, "Journalling dirty buffer"); 637f91d1d04SJan Kara clear_buffer_dirty(bh); 638f91d1d04SJan Kara set_buffer_jbddirty(bh); 639470decc6SDave Kleikamp } 640470decc6SDave Kleikamp 641470decc6SDave Kleikamp unlock_buffer(bh); 642470decc6SDave Kleikamp 643470decc6SDave Kleikamp error = -EROFS; 644470decc6SDave Kleikamp if (is_handle_aborted(handle)) { 645470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 646470decc6SDave Kleikamp goto out; 647470decc6SDave Kleikamp } 648470decc6SDave Kleikamp error = 0; 649470decc6SDave Kleikamp 650470decc6SDave Kleikamp /* 651470decc6SDave Kleikamp * The buffer is already part of this transaction if b_transaction or 652470decc6SDave Kleikamp * b_next_transaction points to it 653470decc6SDave Kleikamp */ 654470decc6SDave Kleikamp if (jh->b_transaction == transaction || 655470decc6SDave Kleikamp jh->b_next_transaction == transaction) 656470decc6SDave Kleikamp goto done; 657470decc6SDave Kleikamp 658470decc6SDave Kleikamp /* 6599fc7c63aSJosef Bacik * this is the first time this transaction is touching this buffer, 6609fc7c63aSJosef Bacik * reset the modified flag 6619fc7c63aSJosef Bacik */ 6629fc7c63aSJosef Bacik jh->b_modified = 0; 6639fc7c63aSJosef Bacik 6649fc7c63aSJosef Bacik /* 665470decc6SDave Kleikamp * If there is already a copy-out version of this buffer, then we don't 666470decc6SDave Kleikamp * need to make another one 667470decc6SDave Kleikamp */ 668470decc6SDave Kleikamp if (jh->b_frozen_data) { 669470decc6SDave Kleikamp JBUFFER_TRACE(jh, "has frozen data"); 670470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_next_transaction == NULL); 671470decc6SDave Kleikamp jh->b_next_transaction = transaction; 672470decc6SDave Kleikamp goto done; 673470decc6SDave Kleikamp } 674470decc6SDave Kleikamp 675470decc6SDave Kleikamp /* Is there data here we need to preserve? */ 676470decc6SDave Kleikamp 677470decc6SDave Kleikamp if (jh->b_transaction && jh->b_transaction != transaction) { 678470decc6SDave Kleikamp JBUFFER_TRACE(jh, "owned by older transaction"); 679470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_next_transaction == NULL); 680470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_transaction == 681470decc6SDave Kleikamp journal->j_committing_transaction); 682470decc6SDave Kleikamp 683470decc6SDave Kleikamp /* There is one case we have to be very careful about. 684470decc6SDave Kleikamp * If the committing transaction is currently writing 685470decc6SDave Kleikamp * this buffer out to disk and has NOT made a copy-out, 686470decc6SDave Kleikamp * then we cannot modify the buffer contents at all 687470decc6SDave Kleikamp * right now. The essence of copy-out is that it is the 688470decc6SDave Kleikamp * extra copy, not the primary copy, which gets 689470decc6SDave Kleikamp * journaled. If the primary copy is already going to 690470decc6SDave Kleikamp * disk then we cannot do copy-out here. */ 691470decc6SDave Kleikamp 692470decc6SDave Kleikamp if (jh->b_jlist == BJ_Shadow) { 693470decc6SDave Kleikamp DEFINE_WAIT_BIT(wait, &bh->b_state, BH_Unshadow); 694470decc6SDave Kleikamp wait_queue_head_t *wqh; 695470decc6SDave Kleikamp 696470decc6SDave Kleikamp wqh = bit_waitqueue(&bh->b_state, BH_Unshadow); 697470decc6SDave Kleikamp 698470decc6SDave Kleikamp JBUFFER_TRACE(jh, "on shadow: sleep"); 699470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 700470decc6SDave Kleikamp /* commit wakes up all shadow buffers after IO */ 701470decc6SDave Kleikamp for ( ; ; ) { 702470decc6SDave Kleikamp prepare_to_wait(wqh, &wait.wait, 703470decc6SDave Kleikamp TASK_UNINTERRUPTIBLE); 704470decc6SDave Kleikamp if (jh->b_jlist != BJ_Shadow) 705470decc6SDave Kleikamp break; 706470decc6SDave Kleikamp schedule(); 707470decc6SDave Kleikamp } 708470decc6SDave Kleikamp finish_wait(wqh, &wait.wait); 709470decc6SDave Kleikamp goto repeat; 710470decc6SDave Kleikamp } 711470decc6SDave Kleikamp 712470decc6SDave Kleikamp /* Only do the copy if the currently-owning transaction 713470decc6SDave Kleikamp * still needs it. If it is on the Forget list, the 714470decc6SDave Kleikamp * committing transaction is past that stage. The 715470decc6SDave Kleikamp * buffer had better remain locked during the kmalloc, 716470decc6SDave Kleikamp * but that should be true --- we hold the journal lock 717470decc6SDave Kleikamp * still and the buffer is already on the BUF_JOURNAL 718470decc6SDave Kleikamp * list so won't be flushed. 719470decc6SDave Kleikamp * 720470decc6SDave Kleikamp * Subtle point, though: if this is a get_undo_access, 721470decc6SDave Kleikamp * then we will be relying on the frozen_data to contain 722470decc6SDave Kleikamp * the new value of the committed_data record after the 723470decc6SDave Kleikamp * transaction, so we HAVE to force the frozen_data copy 724470decc6SDave Kleikamp * in that case. */ 725470decc6SDave Kleikamp 726470decc6SDave Kleikamp if (jh->b_jlist != BJ_Forget || force_copy) { 727470decc6SDave Kleikamp JBUFFER_TRACE(jh, "generate frozen data"); 728470decc6SDave Kleikamp if (!frozen_buffer) { 729470decc6SDave Kleikamp JBUFFER_TRACE(jh, "allocate memory for buffer"); 730470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 731470decc6SDave Kleikamp frozen_buffer = 732af1e76d6SMingming Cao jbd2_alloc(jh2bh(jh)->b_size, 733470decc6SDave Kleikamp GFP_NOFS); 734470decc6SDave Kleikamp if (!frozen_buffer) { 735470decc6SDave Kleikamp printk(KERN_EMERG 736470decc6SDave Kleikamp "%s: OOM for frozen_buffer\n", 737329d291fSHarvey Harrison __func__); 738470decc6SDave Kleikamp JBUFFER_TRACE(jh, "oom!"); 739470decc6SDave Kleikamp error = -ENOMEM; 740470decc6SDave Kleikamp jbd_lock_bh_state(bh); 741470decc6SDave Kleikamp goto done; 742470decc6SDave Kleikamp } 743470decc6SDave Kleikamp goto repeat; 744470decc6SDave Kleikamp } 745470decc6SDave Kleikamp jh->b_frozen_data = frozen_buffer; 746470decc6SDave Kleikamp frozen_buffer = NULL; 747470decc6SDave Kleikamp need_copy = 1; 748470decc6SDave Kleikamp } 749470decc6SDave Kleikamp jh->b_next_transaction = transaction; 750470decc6SDave Kleikamp } 751470decc6SDave Kleikamp 752470decc6SDave Kleikamp 753470decc6SDave Kleikamp /* 754470decc6SDave Kleikamp * Finally, if the buffer is not journaled right now, we need to make 755470decc6SDave Kleikamp * sure it doesn't get written to disk before the caller actually 756470decc6SDave Kleikamp * commits the new data 757470decc6SDave Kleikamp */ 758470decc6SDave Kleikamp if (!jh->b_transaction) { 759470decc6SDave Kleikamp JBUFFER_TRACE(jh, "no transaction"); 760470decc6SDave Kleikamp J_ASSERT_JH(jh, !jh->b_next_transaction); 761470decc6SDave Kleikamp jh->b_transaction = transaction; 762470decc6SDave Kleikamp JBUFFER_TRACE(jh, "file as BJ_Reserved"); 763470decc6SDave Kleikamp spin_lock(&journal->j_list_lock); 764f7f4bccbSMingming Cao __jbd2_journal_file_buffer(jh, transaction, BJ_Reserved); 765470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 766470decc6SDave Kleikamp } 767470decc6SDave Kleikamp 768470decc6SDave Kleikamp done: 769470decc6SDave Kleikamp if (need_copy) { 770470decc6SDave Kleikamp struct page *page; 771470decc6SDave Kleikamp int offset; 772470decc6SDave Kleikamp char *source; 773470decc6SDave Kleikamp 774470decc6SDave Kleikamp J_EXPECT_JH(jh, buffer_uptodate(jh2bh(jh)), 775470decc6SDave Kleikamp "Possible IO failure.\n"); 776470decc6SDave Kleikamp page = jh2bh(jh)->b_page; 777470decc6SDave Kleikamp offset = ((unsigned long) jh2bh(jh)->b_data) & ~PAGE_MASK; 778470decc6SDave Kleikamp source = kmap_atomic(page, KM_USER0); 77913ceef09SJan Kara /* Fire data frozen trigger just before we copy the data */ 78013ceef09SJan Kara jbd2_buffer_frozen_trigger(jh, source + offset, 78113ceef09SJan Kara jh->b_triggers); 782470decc6SDave Kleikamp memcpy(jh->b_frozen_data, source+offset, jh2bh(jh)->b_size); 783470decc6SDave Kleikamp kunmap_atomic(source, KM_USER0); 784e06c8227SJoel Becker 785e06c8227SJoel Becker /* 786e06c8227SJoel Becker * Now that the frozen data is saved off, we need to store 787e06c8227SJoel Becker * any matching triggers. 788e06c8227SJoel Becker */ 789e06c8227SJoel Becker jh->b_frozen_triggers = jh->b_triggers; 790470decc6SDave Kleikamp } 791470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 792470decc6SDave Kleikamp 793470decc6SDave Kleikamp /* 794470decc6SDave Kleikamp * If we are about to journal a buffer, then any revoke pending on it is 795470decc6SDave Kleikamp * no longer valid 796470decc6SDave Kleikamp */ 797f7f4bccbSMingming Cao jbd2_journal_cancel_revoke(handle, jh); 798470decc6SDave Kleikamp 799470decc6SDave Kleikamp out: 800470decc6SDave Kleikamp if (unlikely(frozen_buffer)) /* It's usually NULL */ 801af1e76d6SMingming Cao jbd2_free(frozen_buffer, bh->b_size); 802470decc6SDave Kleikamp 803470decc6SDave Kleikamp JBUFFER_TRACE(jh, "exit"); 804470decc6SDave Kleikamp return error; 805470decc6SDave Kleikamp } 806470decc6SDave Kleikamp 807470decc6SDave Kleikamp /** 808f7f4bccbSMingming Cao * int jbd2_journal_get_write_access() - notify intent to modify a buffer for metadata (not data) update. 809470decc6SDave Kleikamp * @handle: transaction to add buffer modifications to 810470decc6SDave Kleikamp * @bh: bh to be used for metadata writes 811470decc6SDave Kleikamp * @credits: variable that will receive credits for the buffer 812470decc6SDave Kleikamp * 813470decc6SDave Kleikamp * Returns an error code or 0 on success. 814470decc6SDave Kleikamp * 815470decc6SDave Kleikamp * In full data journalling mode the buffer may be of type BJ_AsyncData, 816470decc6SDave Kleikamp * because we're write()ing a buffer which is also part of a shared mapping. 817470decc6SDave Kleikamp */ 818470decc6SDave Kleikamp 819f7f4bccbSMingming Cao int jbd2_journal_get_write_access(handle_t *handle, struct buffer_head *bh) 820470decc6SDave Kleikamp { 821f7f4bccbSMingming Cao struct journal_head *jh = jbd2_journal_add_journal_head(bh); 822470decc6SDave Kleikamp int rc; 823470decc6SDave Kleikamp 824470decc6SDave Kleikamp /* We do not want to get caught playing with fields which the 825470decc6SDave Kleikamp * log thread also manipulates. Make sure that the buffer 826470decc6SDave Kleikamp * completes any outstanding IO before proceeding. */ 827470decc6SDave Kleikamp rc = do_get_write_access(handle, jh, 0); 828f7f4bccbSMingming Cao jbd2_journal_put_journal_head(jh); 829470decc6SDave Kleikamp return rc; 830470decc6SDave Kleikamp } 831470decc6SDave Kleikamp 832470decc6SDave Kleikamp 833470decc6SDave Kleikamp /* 834470decc6SDave Kleikamp * When the user wants to journal a newly created buffer_head 835470decc6SDave Kleikamp * (ie. getblk() returned a new buffer and we are going to populate it 836470decc6SDave Kleikamp * manually rather than reading off disk), then we need to keep the 837470decc6SDave Kleikamp * buffer_head locked until it has been completely filled with new 838470decc6SDave Kleikamp * data. In this case, we should be able to make the assertion that 839470decc6SDave Kleikamp * the bh is not already part of an existing transaction. 840470decc6SDave Kleikamp * 841470decc6SDave Kleikamp * The buffer should already be locked by the caller by this point. 842470decc6SDave Kleikamp * There is no lock ranking violation: it was a newly created, 843470decc6SDave Kleikamp * unlocked buffer beforehand. */ 844470decc6SDave Kleikamp 845470decc6SDave Kleikamp /** 846f7f4bccbSMingming Cao * int jbd2_journal_get_create_access () - notify intent to use newly created bh 847470decc6SDave Kleikamp * @handle: transaction to new buffer to 848470decc6SDave Kleikamp * @bh: new buffer. 849470decc6SDave Kleikamp * 850470decc6SDave Kleikamp * Call this if you create a new bh. 851470decc6SDave Kleikamp */ 852f7f4bccbSMingming Cao int jbd2_journal_get_create_access(handle_t *handle, struct buffer_head *bh) 853470decc6SDave Kleikamp { 854470decc6SDave Kleikamp transaction_t *transaction = handle->h_transaction; 855470decc6SDave Kleikamp journal_t *journal = transaction->t_journal; 856f7f4bccbSMingming Cao struct journal_head *jh = jbd2_journal_add_journal_head(bh); 857470decc6SDave Kleikamp int err; 858470decc6SDave Kleikamp 859470decc6SDave Kleikamp jbd_debug(5, "journal_head %p\n", jh); 860470decc6SDave Kleikamp err = -EROFS; 861470decc6SDave Kleikamp if (is_handle_aborted(handle)) 862470decc6SDave Kleikamp goto out; 863470decc6SDave Kleikamp err = 0; 864470decc6SDave Kleikamp 865470decc6SDave Kleikamp JBUFFER_TRACE(jh, "entry"); 866470decc6SDave Kleikamp /* 867470decc6SDave Kleikamp * The buffer may already belong to this transaction due to pre-zeroing 868470decc6SDave Kleikamp * in the filesystem's new_block code. It may also be on the previous, 869470decc6SDave Kleikamp * committing transaction's lists, but it HAS to be in Forget state in 870470decc6SDave Kleikamp * that case: the transaction must have deleted the buffer for it to be 871470decc6SDave Kleikamp * reused here. 872470decc6SDave Kleikamp */ 873470decc6SDave Kleikamp jbd_lock_bh_state(bh); 874470decc6SDave Kleikamp spin_lock(&journal->j_list_lock); 875470decc6SDave Kleikamp J_ASSERT_JH(jh, (jh->b_transaction == transaction || 876470decc6SDave Kleikamp jh->b_transaction == NULL || 877470decc6SDave Kleikamp (jh->b_transaction == journal->j_committing_transaction && 878470decc6SDave Kleikamp jh->b_jlist == BJ_Forget))); 879470decc6SDave Kleikamp 880470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_next_transaction == NULL); 881470decc6SDave Kleikamp J_ASSERT_JH(jh, buffer_locked(jh2bh(jh))); 882470decc6SDave Kleikamp 883470decc6SDave Kleikamp if (jh->b_transaction == NULL) { 884f91d1d04SJan Kara /* 885f91d1d04SJan Kara * Previous jbd2_journal_forget() could have left the buffer 886f91d1d04SJan Kara * with jbddirty bit set because it was being committed. When 887f91d1d04SJan Kara * the commit finished, we've filed the buffer for 888f91d1d04SJan Kara * checkpointing and marked it dirty. Now we are reallocating 889f91d1d04SJan Kara * the buffer so the transaction freeing it must have 890f91d1d04SJan Kara * committed and so it's safe to clear the dirty bit. 891f91d1d04SJan Kara */ 892f91d1d04SJan Kara clear_buffer_dirty(jh2bh(jh)); 893470decc6SDave Kleikamp jh->b_transaction = transaction; 8949fc7c63aSJosef Bacik 8959fc7c63aSJosef Bacik /* first access by this transaction */ 8969fc7c63aSJosef Bacik jh->b_modified = 0; 8979fc7c63aSJosef Bacik 898470decc6SDave Kleikamp JBUFFER_TRACE(jh, "file as BJ_Reserved"); 899f7f4bccbSMingming Cao __jbd2_journal_file_buffer(jh, transaction, BJ_Reserved); 900470decc6SDave Kleikamp } else if (jh->b_transaction == journal->j_committing_transaction) { 9019fc7c63aSJosef Bacik /* first access by this transaction */ 9029fc7c63aSJosef Bacik jh->b_modified = 0; 9039fc7c63aSJosef Bacik 904470decc6SDave Kleikamp JBUFFER_TRACE(jh, "set next transaction"); 905470decc6SDave Kleikamp jh->b_next_transaction = transaction; 906470decc6SDave Kleikamp } 907470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 908470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 909470decc6SDave Kleikamp 910470decc6SDave Kleikamp /* 911470decc6SDave Kleikamp * akpm: I added this. ext3_alloc_branch can pick up new indirect 912470decc6SDave Kleikamp * blocks which contain freed but then revoked metadata. We need 913470decc6SDave Kleikamp * to cancel the revoke in case we end up freeing it yet again 914470decc6SDave Kleikamp * and the reallocating as data - this would cause a second revoke, 915470decc6SDave Kleikamp * which hits an assertion error. 916470decc6SDave Kleikamp */ 917470decc6SDave Kleikamp JBUFFER_TRACE(jh, "cancelling revoke"); 918f7f4bccbSMingming Cao jbd2_journal_cancel_revoke(handle, jh); 919f7f4bccbSMingming Cao jbd2_journal_put_journal_head(jh); 920470decc6SDave Kleikamp out: 921470decc6SDave Kleikamp return err; 922470decc6SDave Kleikamp } 923470decc6SDave Kleikamp 924470decc6SDave Kleikamp /** 925f7f4bccbSMingming Cao * int jbd2_journal_get_undo_access() - Notify intent to modify metadata with 926470decc6SDave Kleikamp * non-rewindable consequences 927470decc6SDave Kleikamp * @handle: transaction 928470decc6SDave Kleikamp * @bh: buffer to undo 929470decc6SDave Kleikamp * @credits: store the number of taken credits here (if not NULL) 930470decc6SDave Kleikamp * 931470decc6SDave Kleikamp * Sometimes there is a need to distinguish between metadata which has 932470decc6SDave Kleikamp * been committed to disk and that which has not. The ext3fs code uses 933470decc6SDave Kleikamp * this for freeing and allocating space, we have to make sure that we 934470decc6SDave Kleikamp * do not reuse freed space until the deallocation has been committed, 935470decc6SDave Kleikamp * since if we overwrote that space we would make the delete 936470decc6SDave Kleikamp * un-rewindable in case of a crash. 937470decc6SDave Kleikamp * 938f7f4bccbSMingming Cao * To deal with that, jbd2_journal_get_undo_access requests write access to a 939470decc6SDave Kleikamp * buffer for parts of non-rewindable operations such as delete 940470decc6SDave Kleikamp * operations on the bitmaps. The journaling code must keep a copy of 941470decc6SDave Kleikamp * the buffer's contents prior to the undo_access call until such time 942470decc6SDave Kleikamp * as we know that the buffer has definitely been committed to disk. 943470decc6SDave Kleikamp * 944470decc6SDave Kleikamp * We never need to know which transaction the committed data is part 945470decc6SDave Kleikamp * of, buffers touched here are guaranteed to be dirtied later and so 946470decc6SDave Kleikamp * will be committed to a new transaction in due course, at which point 947470decc6SDave Kleikamp * we can discard the old committed data pointer. 948470decc6SDave Kleikamp * 949470decc6SDave Kleikamp * Returns error number or 0 on success. 950470decc6SDave Kleikamp */ 951f7f4bccbSMingming Cao int jbd2_journal_get_undo_access(handle_t *handle, struct buffer_head *bh) 952470decc6SDave Kleikamp { 953470decc6SDave Kleikamp int err; 954f7f4bccbSMingming Cao struct journal_head *jh = jbd2_journal_add_journal_head(bh); 955470decc6SDave Kleikamp char *committed_data = NULL; 956470decc6SDave Kleikamp 957470decc6SDave Kleikamp JBUFFER_TRACE(jh, "entry"); 958470decc6SDave Kleikamp 959470decc6SDave Kleikamp /* 960470decc6SDave Kleikamp * Do this first --- it can drop the journal lock, so we want to 961470decc6SDave Kleikamp * make sure that obtaining the committed_data is done 962470decc6SDave Kleikamp * atomically wrt. completion of any outstanding commits. 963470decc6SDave Kleikamp */ 964470decc6SDave Kleikamp err = do_get_write_access(handle, jh, 1); 965470decc6SDave Kleikamp if (err) 966470decc6SDave Kleikamp goto out; 967470decc6SDave Kleikamp 968470decc6SDave Kleikamp repeat: 969470decc6SDave Kleikamp if (!jh->b_committed_data) { 970af1e76d6SMingming Cao committed_data = jbd2_alloc(jh2bh(jh)->b_size, GFP_NOFS); 971470decc6SDave Kleikamp if (!committed_data) { 972470decc6SDave Kleikamp printk(KERN_EMERG "%s: No memory for committed data\n", 973329d291fSHarvey Harrison __func__); 974470decc6SDave Kleikamp err = -ENOMEM; 975470decc6SDave Kleikamp goto out; 976470decc6SDave Kleikamp } 977470decc6SDave Kleikamp } 978470decc6SDave Kleikamp 979470decc6SDave Kleikamp jbd_lock_bh_state(bh); 980470decc6SDave Kleikamp if (!jh->b_committed_data) { 981470decc6SDave Kleikamp /* Copy out the current buffer contents into the 982470decc6SDave Kleikamp * preserved, committed copy. */ 983470decc6SDave Kleikamp JBUFFER_TRACE(jh, "generate b_committed data"); 984470decc6SDave Kleikamp if (!committed_data) { 985470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 986470decc6SDave Kleikamp goto repeat; 987470decc6SDave Kleikamp } 988470decc6SDave Kleikamp 989470decc6SDave Kleikamp jh->b_committed_data = committed_data; 990470decc6SDave Kleikamp committed_data = NULL; 991470decc6SDave Kleikamp memcpy(jh->b_committed_data, bh->b_data, bh->b_size); 992470decc6SDave Kleikamp } 993470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 994470decc6SDave Kleikamp out: 995f7f4bccbSMingming Cao jbd2_journal_put_journal_head(jh); 996470decc6SDave Kleikamp if (unlikely(committed_data)) 997af1e76d6SMingming Cao jbd2_free(committed_data, bh->b_size); 998470decc6SDave Kleikamp return err; 999470decc6SDave Kleikamp } 1000470decc6SDave Kleikamp 1001470decc6SDave Kleikamp /** 1002e06c8227SJoel Becker * void jbd2_journal_set_triggers() - Add triggers for commit writeout 1003e06c8227SJoel Becker * @bh: buffer to trigger on 1004e06c8227SJoel Becker * @type: struct jbd2_buffer_trigger_type containing the trigger(s). 1005e06c8227SJoel Becker * 1006e06c8227SJoel Becker * Set any triggers on this journal_head. This is always safe, because 1007e06c8227SJoel Becker * triggers for a committing buffer will be saved off, and triggers for 1008e06c8227SJoel Becker * a running transaction will match the buffer in that transaction. 1009e06c8227SJoel Becker * 1010e06c8227SJoel Becker * Call with NULL to clear the triggers. 1011e06c8227SJoel Becker */ 1012e06c8227SJoel Becker void jbd2_journal_set_triggers(struct buffer_head *bh, 1013e06c8227SJoel Becker struct jbd2_buffer_trigger_type *type) 1014e06c8227SJoel Becker { 1015e06c8227SJoel Becker struct journal_head *jh = bh2jh(bh); 1016e06c8227SJoel Becker 1017e06c8227SJoel Becker jh->b_triggers = type; 1018e06c8227SJoel Becker } 1019e06c8227SJoel Becker 102013ceef09SJan Kara void jbd2_buffer_frozen_trigger(struct journal_head *jh, void *mapped_data, 1021e06c8227SJoel Becker struct jbd2_buffer_trigger_type *triggers) 1022e06c8227SJoel Becker { 1023e06c8227SJoel Becker struct buffer_head *bh = jh2bh(jh); 1024e06c8227SJoel Becker 102513ceef09SJan Kara if (!triggers || !triggers->t_frozen) 1026e06c8227SJoel Becker return; 1027e06c8227SJoel Becker 102813ceef09SJan Kara triggers->t_frozen(triggers, bh, mapped_data, bh->b_size); 1029e06c8227SJoel Becker } 1030e06c8227SJoel Becker 1031e06c8227SJoel Becker void jbd2_buffer_abort_trigger(struct journal_head *jh, 1032e06c8227SJoel Becker struct jbd2_buffer_trigger_type *triggers) 1033e06c8227SJoel Becker { 1034e06c8227SJoel Becker if (!triggers || !triggers->t_abort) 1035e06c8227SJoel Becker return; 1036e06c8227SJoel Becker 1037e06c8227SJoel Becker triggers->t_abort(triggers, jh2bh(jh)); 1038e06c8227SJoel Becker } 1039e06c8227SJoel Becker 1040e06c8227SJoel Becker 1041e06c8227SJoel Becker 1042e06c8227SJoel Becker /** 1043f7f4bccbSMingming Cao * int jbd2_journal_dirty_metadata() - mark a buffer as containing dirty metadata 1044470decc6SDave Kleikamp * @handle: transaction to add buffer to. 1045470decc6SDave Kleikamp * @bh: buffer to mark 1046470decc6SDave Kleikamp * 1047470decc6SDave Kleikamp * mark dirty metadata which needs to be journaled as part of the current 1048470decc6SDave Kleikamp * transaction. 1049470decc6SDave Kleikamp * 1050470decc6SDave Kleikamp * The buffer is placed on the transaction's metadata list and is marked 1051470decc6SDave Kleikamp * as belonging to the transaction. 1052470decc6SDave Kleikamp * 1053470decc6SDave Kleikamp * Returns error number or 0 on success. 1054470decc6SDave Kleikamp * 1055470decc6SDave Kleikamp * Special care needs to be taken if the buffer already belongs to the 1056470decc6SDave Kleikamp * current committing transaction (in which case we should have frozen 1057470decc6SDave Kleikamp * data present for that commit). In that case, we don't relink the 1058470decc6SDave Kleikamp * buffer: that only gets done when the old transaction finally 1059470decc6SDave Kleikamp * completes its commit. 1060470decc6SDave Kleikamp */ 1061f7f4bccbSMingming Cao int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh) 1062470decc6SDave Kleikamp { 1063470decc6SDave Kleikamp transaction_t *transaction = handle->h_transaction; 1064470decc6SDave Kleikamp journal_t *journal = transaction->t_journal; 1065470decc6SDave Kleikamp struct journal_head *jh = bh2jh(bh); 1066470decc6SDave Kleikamp 1067470decc6SDave Kleikamp jbd_debug(5, "journal_head %p\n", jh); 1068470decc6SDave Kleikamp JBUFFER_TRACE(jh, "entry"); 1069470decc6SDave Kleikamp if (is_handle_aborted(handle)) 1070470decc6SDave Kleikamp goto out; 1071470decc6SDave Kleikamp 1072470decc6SDave Kleikamp jbd_lock_bh_state(bh); 1073470decc6SDave Kleikamp 1074470decc6SDave Kleikamp if (jh->b_modified == 0) { 1075470decc6SDave Kleikamp /* 1076470decc6SDave Kleikamp * This buffer's got modified and becoming part 1077470decc6SDave Kleikamp * of the transaction. This needs to be done 1078470decc6SDave Kleikamp * once a transaction -bzzz 1079470decc6SDave Kleikamp */ 1080470decc6SDave Kleikamp jh->b_modified = 1; 1081470decc6SDave Kleikamp J_ASSERT_JH(jh, handle->h_buffer_credits > 0); 1082470decc6SDave Kleikamp handle->h_buffer_credits--; 1083470decc6SDave Kleikamp } 1084470decc6SDave Kleikamp 1085470decc6SDave Kleikamp /* 1086470decc6SDave Kleikamp * fastpath, to avoid expensive locking. If this buffer is already 1087470decc6SDave Kleikamp * on the running transaction's metadata list there is nothing to do. 1088470decc6SDave Kleikamp * Nobody can take it off again because there is a handle open. 1089470decc6SDave Kleikamp * I _think_ we're OK here with SMP barriers - a mistaken decision will 1090470decc6SDave Kleikamp * result in this test being false, so we go in and take the locks. 1091470decc6SDave Kleikamp */ 1092470decc6SDave Kleikamp if (jh->b_transaction == transaction && jh->b_jlist == BJ_Metadata) { 1093470decc6SDave Kleikamp JBUFFER_TRACE(jh, "fastpath"); 1094470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_transaction == 1095470decc6SDave Kleikamp journal->j_running_transaction); 1096470decc6SDave Kleikamp goto out_unlock_bh; 1097470decc6SDave Kleikamp } 1098470decc6SDave Kleikamp 1099470decc6SDave Kleikamp set_buffer_jbddirty(bh); 1100470decc6SDave Kleikamp 1101470decc6SDave Kleikamp /* 1102470decc6SDave Kleikamp * Metadata already on the current transaction list doesn't 1103470decc6SDave Kleikamp * need to be filed. Metadata on another transaction's list must 1104470decc6SDave Kleikamp * be committing, and will be refiled once the commit completes: 1105470decc6SDave Kleikamp * leave it alone for now. 1106470decc6SDave Kleikamp */ 1107470decc6SDave Kleikamp if (jh->b_transaction != transaction) { 1108470decc6SDave Kleikamp JBUFFER_TRACE(jh, "already on other transaction"); 1109470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_transaction == 1110470decc6SDave Kleikamp journal->j_committing_transaction); 1111470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_next_transaction == transaction); 1112470decc6SDave Kleikamp /* And this case is illegal: we can't reuse another 1113470decc6SDave Kleikamp * transaction's data buffer, ever. */ 1114470decc6SDave Kleikamp goto out_unlock_bh; 1115470decc6SDave Kleikamp } 1116470decc6SDave Kleikamp 1117470decc6SDave Kleikamp /* That test should have eliminated the following case: */ 11184019191bSMingming Cao J_ASSERT_JH(jh, jh->b_frozen_data == NULL); 1119470decc6SDave Kleikamp 1120470decc6SDave Kleikamp JBUFFER_TRACE(jh, "file as BJ_Metadata"); 1121470decc6SDave Kleikamp spin_lock(&journal->j_list_lock); 1122f7f4bccbSMingming Cao __jbd2_journal_file_buffer(jh, handle->h_transaction, BJ_Metadata); 1123470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 1124470decc6SDave Kleikamp out_unlock_bh: 1125470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 1126470decc6SDave Kleikamp out: 1127470decc6SDave Kleikamp JBUFFER_TRACE(jh, "exit"); 1128470decc6SDave Kleikamp return 0; 1129470decc6SDave Kleikamp } 1130470decc6SDave Kleikamp 1131470decc6SDave Kleikamp /* 1132f7f4bccbSMingming Cao * jbd2_journal_release_buffer: undo a get_write_access without any buffer 1133470decc6SDave Kleikamp * updates, if the update decided in the end that it didn't need access. 1134470decc6SDave Kleikamp * 1135470decc6SDave Kleikamp */ 1136470decc6SDave Kleikamp void 1137f7f4bccbSMingming Cao jbd2_journal_release_buffer(handle_t *handle, struct buffer_head *bh) 1138470decc6SDave Kleikamp { 1139470decc6SDave Kleikamp BUFFER_TRACE(bh, "entry"); 1140470decc6SDave Kleikamp } 1141470decc6SDave Kleikamp 1142470decc6SDave Kleikamp /** 1143f7f4bccbSMingming Cao * void jbd2_journal_forget() - bforget() for potentially-journaled buffers. 1144470decc6SDave Kleikamp * @handle: transaction handle 1145470decc6SDave Kleikamp * @bh: bh to 'forget' 1146470decc6SDave Kleikamp * 1147470decc6SDave Kleikamp * We can only do the bforget if there are no commits pending against the 1148470decc6SDave Kleikamp * buffer. If the buffer is dirty in the current running transaction we 1149470decc6SDave Kleikamp * can safely unlink it. 1150470decc6SDave Kleikamp * 1151470decc6SDave Kleikamp * bh may not be a journalled buffer at all - it may be a non-JBD 1152470decc6SDave Kleikamp * buffer which came off the hashtable. Check for this. 1153470decc6SDave Kleikamp * 1154470decc6SDave Kleikamp * Decrements bh->b_count by one. 1155470decc6SDave Kleikamp * 1156470decc6SDave Kleikamp * Allow this call even if the handle has aborted --- it may be part of 1157470decc6SDave Kleikamp * the caller's cleanup after an abort. 1158470decc6SDave Kleikamp */ 1159f7f4bccbSMingming Cao int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh) 1160470decc6SDave Kleikamp { 1161470decc6SDave Kleikamp transaction_t *transaction = handle->h_transaction; 1162470decc6SDave Kleikamp journal_t *journal = transaction->t_journal; 1163470decc6SDave Kleikamp struct journal_head *jh; 1164470decc6SDave Kleikamp int drop_reserve = 0; 1165470decc6SDave Kleikamp int err = 0; 11661dfc3220SJosef Bacik int was_modified = 0; 1167470decc6SDave Kleikamp 1168470decc6SDave Kleikamp BUFFER_TRACE(bh, "entry"); 1169470decc6SDave Kleikamp 1170470decc6SDave Kleikamp jbd_lock_bh_state(bh); 1171470decc6SDave Kleikamp spin_lock(&journal->j_list_lock); 1172470decc6SDave Kleikamp 1173470decc6SDave Kleikamp if (!buffer_jbd(bh)) 1174470decc6SDave Kleikamp goto not_jbd; 1175470decc6SDave Kleikamp jh = bh2jh(bh); 1176470decc6SDave Kleikamp 1177470decc6SDave Kleikamp /* Critical error: attempting to delete a bitmap buffer, maybe? 1178470decc6SDave Kleikamp * Don't do any jbd operations, and return an error. */ 1179470decc6SDave Kleikamp if (!J_EXPECT_JH(jh, !jh->b_committed_data, 1180470decc6SDave Kleikamp "inconsistent data on disk")) { 1181470decc6SDave Kleikamp err = -EIO; 1182470decc6SDave Kleikamp goto not_jbd; 1183470decc6SDave Kleikamp } 1184470decc6SDave Kleikamp 11851dfc3220SJosef Bacik /* keep track of wether or not this transaction modified us */ 11861dfc3220SJosef Bacik was_modified = jh->b_modified; 11871dfc3220SJosef Bacik 1188470decc6SDave Kleikamp /* 1189470decc6SDave Kleikamp * The buffer's going from the transaction, we must drop 1190470decc6SDave Kleikamp * all references -bzzz 1191470decc6SDave Kleikamp */ 1192470decc6SDave Kleikamp jh->b_modified = 0; 1193470decc6SDave Kleikamp 1194470decc6SDave Kleikamp if (jh->b_transaction == handle->h_transaction) { 1195470decc6SDave Kleikamp J_ASSERT_JH(jh, !jh->b_frozen_data); 1196470decc6SDave Kleikamp 1197470decc6SDave Kleikamp /* If we are forgetting a buffer which is already part 1198470decc6SDave Kleikamp * of this transaction, then we can just drop it from 1199470decc6SDave Kleikamp * the transaction immediately. */ 1200470decc6SDave Kleikamp clear_buffer_dirty(bh); 1201470decc6SDave Kleikamp clear_buffer_jbddirty(bh); 1202470decc6SDave Kleikamp 1203470decc6SDave Kleikamp JBUFFER_TRACE(jh, "belongs to current transaction: unfile"); 1204470decc6SDave Kleikamp 12051dfc3220SJosef Bacik /* 12061dfc3220SJosef Bacik * we only want to drop a reference if this transaction 12071dfc3220SJosef Bacik * modified the buffer 12081dfc3220SJosef Bacik */ 12091dfc3220SJosef Bacik if (was_modified) 1210470decc6SDave Kleikamp drop_reserve = 1; 1211470decc6SDave Kleikamp 1212470decc6SDave Kleikamp /* 1213470decc6SDave Kleikamp * We are no longer going to journal this buffer. 1214470decc6SDave Kleikamp * However, the commit of this transaction is still 1215470decc6SDave Kleikamp * important to the buffer: the delete that we are now 1216470decc6SDave Kleikamp * processing might obsolete an old log entry, so by 1217470decc6SDave Kleikamp * committing, we can satisfy the buffer's checkpoint. 1218470decc6SDave Kleikamp * 1219470decc6SDave Kleikamp * So, if we have a checkpoint on the buffer, we should 1220470decc6SDave Kleikamp * now refile the buffer on our BJ_Forget list so that 1221470decc6SDave Kleikamp * we know to remove the checkpoint after we commit. 1222470decc6SDave Kleikamp */ 1223470decc6SDave Kleikamp 1224470decc6SDave Kleikamp if (jh->b_cp_transaction) { 1225f7f4bccbSMingming Cao __jbd2_journal_temp_unlink_buffer(jh); 1226f7f4bccbSMingming Cao __jbd2_journal_file_buffer(jh, transaction, BJ_Forget); 1227470decc6SDave Kleikamp } else { 1228f7f4bccbSMingming Cao __jbd2_journal_unfile_buffer(jh); 1229f7f4bccbSMingming Cao jbd2_journal_remove_journal_head(bh); 1230470decc6SDave Kleikamp __brelse(bh); 1231470decc6SDave Kleikamp if (!buffer_jbd(bh)) { 1232470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 1233470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 1234470decc6SDave Kleikamp __bforget(bh); 1235470decc6SDave Kleikamp goto drop; 1236470decc6SDave Kleikamp } 1237470decc6SDave Kleikamp } 1238470decc6SDave Kleikamp } else if (jh->b_transaction) { 1239470decc6SDave Kleikamp J_ASSERT_JH(jh, (jh->b_transaction == 1240470decc6SDave Kleikamp journal->j_committing_transaction)); 1241470decc6SDave Kleikamp /* However, if the buffer is still owned by a prior 1242470decc6SDave Kleikamp * (committing) transaction, we can't drop it yet... */ 1243470decc6SDave Kleikamp JBUFFER_TRACE(jh, "belongs to older transaction"); 1244470decc6SDave Kleikamp /* ... but we CAN drop it from the new transaction if we 1245470decc6SDave Kleikamp * have also modified it since the original commit. */ 1246470decc6SDave Kleikamp 1247470decc6SDave Kleikamp if (jh->b_next_transaction) { 1248470decc6SDave Kleikamp J_ASSERT(jh->b_next_transaction == transaction); 1249470decc6SDave Kleikamp jh->b_next_transaction = NULL; 12501dfc3220SJosef Bacik 12511dfc3220SJosef Bacik /* 12521dfc3220SJosef Bacik * only drop a reference if this transaction modified 12531dfc3220SJosef Bacik * the buffer 12541dfc3220SJosef Bacik */ 12551dfc3220SJosef Bacik if (was_modified) 1256470decc6SDave Kleikamp drop_reserve = 1; 1257470decc6SDave Kleikamp } 1258470decc6SDave Kleikamp } 1259470decc6SDave Kleikamp 1260470decc6SDave Kleikamp not_jbd: 1261470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 1262470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 1263470decc6SDave Kleikamp __brelse(bh); 1264470decc6SDave Kleikamp drop: 1265470decc6SDave Kleikamp if (drop_reserve) { 1266470decc6SDave Kleikamp /* no need to reserve log space for this block -bzzz */ 1267470decc6SDave Kleikamp handle->h_buffer_credits++; 1268470decc6SDave Kleikamp } 1269470decc6SDave Kleikamp return err; 1270470decc6SDave Kleikamp } 1271470decc6SDave Kleikamp 1272470decc6SDave Kleikamp /** 1273f7f4bccbSMingming Cao * int jbd2_journal_stop() - complete a transaction 1274470decc6SDave Kleikamp * @handle: tranaction to complete. 1275470decc6SDave Kleikamp * 1276470decc6SDave Kleikamp * All done for a particular handle. 1277470decc6SDave Kleikamp * 1278470decc6SDave Kleikamp * There is not much action needed here. We just return any remaining 1279470decc6SDave Kleikamp * buffer credits to the transaction and remove the handle. The only 1280470decc6SDave Kleikamp * complication is that we need to start a commit operation if the 1281470decc6SDave Kleikamp * filesystem is marked for synchronous update. 1282470decc6SDave Kleikamp * 1283f7f4bccbSMingming Cao * jbd2_journal_stop itself will not usually return an error, but it may 1284470decc6SDave Kleikamp * do so in unusual circumstances. In particular, expect it to 1285f7f4bccbSMingming Cao * return -EIO if a jbd2_journal_abort has been executed since the 1286470decc6SDave Kleikamp * transaction began. 1287470decc6SDave Kleikamp */ 1288f7f4bccbSMingming Cao int jbd2_journal_stop(handle_t *handle) 1289470decc6SDave Kleikamp { 1290470decc6SDave Kleikamp transaction_t *transaction = handle->h_transaction; 1291470decc6SDave Kleikamp journal_t *journal = transaction->t_journal; 1292a51dca9cSTheodore Ts'o int err, wait_for_commit = 0; 1293a51dca9cSTheodore Ts'o tid_t tid; 1294470decc6SDave Kleikamp pid_t pid; 1295470decc6SDave Kleikamp 1296470decc6SDave Kleikamp J_ASSERT(journal_current_handle() == handle); 1297470decc6SDave Kleikamp 1298470decc6SDave Kleikamp if (is_handle_aborted(handle)) 1299470decc6SDave Kleikamp err = -EIO; 13003e2a532bSOGAWA Hirofumi else { 1301a51dca9cSTheodore Ts'o J_ASSERT(atomic_read(&transaction->t_updates) > 0); 1302470decc6SDave Kleikamp err = 0; 13033e2a532bSOGAWA Hirofumi } 1304470decc6SDave Kleikamp 1305470decc6SDave Kleikamp if (--handle->h_ref > 0) { 1306470decc6SDave Kleikamp jbd_debug(4, "h_ref %d -> %d\n", handle->h_ref + 1, 1307470decc6SDave Kleikamp handle->h_ref); 1308470decc6SDave Kleikamp return err; 1309470decc6SDave Kleikamp } 1310470decc6SDave Kleikamp 1311470decc6SDave Kleikamp jbd_debug(4, "Handle %p going down\n", handle); 1312470decc6SDave Kleikamp 1313470decc6SDave Kleikamp /* 1314470decc6SDave Kleikamp * Implement synchronous transaction batching. If the handle 1315470decc6SDave Kleikamp * was synchronous, don't force a commit immediately. Let's 1316e07f7183SJosef Bacik * yield and let another thread piggyback onto this 1317e07f7183SJosef Bacik * transaction. Keep doing that while new threads continue to 1318e07f7183SJosef Bacik * arrive. It doesn't cost much - we're about to run a commit 1319e07f7183SJosef Bacik * and sleep on IO anyway. Speeds up many-threaded, many-dir 1320e07f7183SJosef Bacik * operations by 30x or more... 1321470decc6SDave Kleikamp * 1322e07f7183SJosef Bacik * We try and optimize the sleep time against what the 1323e07f7183SJosef Bacik * underlying disk can do, instead of having a static sleep 1324e07f7183SJosef Bacik * time. This is useful for the case where our storage is so 1325e07f7183SJosef Bacik * fast that it is more optimal to go ahead and force a flush 1326e07f7183SJosef Bacik * and wait for the transaction to be committed than it is to 1327e07f7183SJosef Bacik * wait for an arbitrary amount of time for new writers to 1328e07f7183SJosef Bacik * join the transaction. We achieve this by measuring how 1329e07f7183SJosef Bacik * long it takes to commit a transaction, and compare it with 1330e07f7183SJosef Bacik * how long this transaction has been running, and if run time 1331e07f7183SJosef Bacik * < commit time then we sleep for the delta and commit. This 1332e07f7183SJosef Bacik * greatly helps super fast disks that would see slowdowns as 1333e07f7183SJosef Bacik * more threads started doing fsyncs. 1334e07f7183SJosef Bacik * 1335e07f7183SJosef Bacik * But don't do this if this process was the most recent one 1336e07f7183SJosef Bacik * to perform a synchronous write. We do this to detect the 1337e07f7183SJosef Bacik * case where a single process is doing a stream of sync 1338e07f7183SJosef Bacik * writes. No point in waiting for joiners in that case. 1339470decc6SDave Kleikamp */ 1340470decc6SDave Kleikamp pid = current->pid; 1341470decc6SDave Kleikamp if (handle->h_sync && journal->j_last_sync_writer != pid) { 1342e07f7183SJosef Bacik u64 commit_time, trans_time; 1343e07f7183SJosef Bacik 1344470decc6SDave Kleikamp journal->j_last_sync_writer = pid; 1345e07f7183SJosef Bacik 1346a931da6aSTheodore Ts'o read_lock(&journal->j_state_lock); 1347e07f7183SJosef Bacik commit_time = journal->j_average_commit_time; 1348a931da6aSTheodore Ts'o read_unlock(&journal->j_state_lock); 1349e07f7183SJosef Bacik 1350e07f7183SJosef Bacik trans_time = ktime_to_ns(ktime_sub(ktime_get(), 1351e07f7183SJosef Bacik transaction->t_start_time)); 1352e07f7183SJosef Bacik 135330773840STheodore Ts'o commit_time = max_t(u64, commit_time, 135430773840STheodore Ts'o 1000*journal->j_min_batch_time); 1355e07f7183SJosef Bacik commit_time = min_t(u64, commit_time, 135630773840STheodore Ts'o 1000*journal->j_max_batch_time); 1357e07f7183SJosef Bacik 1358e07f7183SJosef Bacik if (trans_time < commit_time) { 1359e07f7183SJosef Bacik ktime_t expires = ktime_add_ns(ktime_get(), 1360e07f7183SJosef Bacik commit_time); 1361e07f7183SJosef Bacik set_current_state(TASK_UNINTERRUPTIBLE); 1362e07f7183SJosef Bacik schedule_hrtimeout(&expires, HRTIMER_MODE_ABS); 1363e07f7183SJosef Bacik } 1364470decc6SDave Kleikamp } 1365470decc6SDave Kleikamp 13667058548cSTheodore Ts'o if (handle->h_sync) 13677058548cSTheodore Ts'o transaction->t_synchronous_commit = 1; 1368470decc6SDave Kleikamp current->journal_info = NULL; 1369a51dca9cSTheodore Ts'o atomic_sub(handle->h_buffer_credits, 1370a51dca9cSTheodore Ts'o &transaction->t_outstanding_credits); 1371470decc6SDave Kleikamp 1372470decc6SDave Kleikamp /* 1373470decc6SDave Kleikamp * If the handle is marked SYNC, we need to set another commit 1374470decc6SDave Kleikamp * going! We also want to force a commit if the current 1375470decc6SDave Kleikamp * transaction is occupying too much of the log, or if the 1376470decc6SDave Kleikamp * transaction is too old now. 1377470decc6SDave Kleikamp */ 1378470decc6SDave Kleikamp if (handle->h_sync || 1379a51dca9cSTheodore Ts'o (atomic_read(&transaction->t_outstanding_credits) > 1380a51dca9cSTheodore Ts'o journal->j_max_transaction_buffers) || 1381470decc6SDave Kleikamp time_after_eq(jiffies, transaction->t_expires)) { 1382470decc6SDave Kleikamp /* Do this even for aborted journals: an abort still 1383470decc6SDave Kleikamp * completes the commit thread, it just doesn't write 1384470decc6SDave Kleikamp * anything to disk. */ 1385470decc6SDave Kleikamp 1386470decc6SDave Kleikamp jbd_debug(2, "transaction too old, requesting commit for " 1387470decc6SDave Kleikamp "handle %p\n", handle); 1388470decc6SDave Kleikamp /* This is non-blocking */ 1389c35a56a0STheodore Ts'o jbd2_log_start_commit(journal, transaction->t_tid); 1390470decc6SDave Kleikamp 1391470decc6SDave Kleikamp /* 1392f7f4bccbSMingming Cao * Special case: JBD2_SYNC synchronous updates require us 1393470decc6SDave Kleikamp * to wait for the commit to complete. 1394470decc6SDave Kleikamp */ 1395470decc6SDave Kleikamp if (handle->h_sync && !(current->flags & PF_MEMALLOC)) 1396a51dca9cSTheodore Ts'o wait_for_commit = 1; 1397470decc6SDave Kleikamp } 1398470decc6SDave Kleikamp 1399a51dca9cSTheodore Ts'o /* 1400a51dca9cSTheodore Ts'o * Once we drop t_updates, if it goes to zero the transaction 1401a51dca9cSTheodore Ts'o * could start commiting on us and eventually disappear. So 1402a51dca9cSTheodore Ts'o * once we do this, we must not dereference transaction 1403a51dca9cSTheodore Ts'o * pointer again. 1404a51dca9cSTheodore Ts'o */ 1405a51dca9cSTheodore Ts'o tid = transaction->t_tid; 1406a51dca9cSTheodore Ts'o if (atomic_dec_and_test(&transaction->t_updates)) { 1407a51dca9cSTheodore Ts'o wake_up(&journal->j_wait_updates); 1408a51dca9cSTheodore Ts'o if (journal->j_barrier_count) 1409a51dca9cSTheodore Ts'o wake_up(&journal->j_wait_transaction_locked); 1410a51dca9cSTheodore Ts'o } 1411a51dca9cSTheodore Ts'o 1412a51dca9cSTheodore Ts'o if (wait_for_commit) 1413a51dca9cSTheodore Ts'o err = jbd2_log_wait_commit(journal, tid); 1414a51dca9cSTheodore Ts'o 14153295f0efSIngo Molnar lock_map_release(&handle->h_lockdep_map); 14167b751066SMingming Cao 1417af1e76d6SMingming Cao jbd2_free_handle(handle); 1418470decc6SDave Kleikamp return err; 1419470decc6SDave Kleikamp } 1420470decc6SDave Kleikamp 14215648ba5bSRandy Dunlap /** 14225648ba5bSRandy Dunlap * int jbd2_journal_force_commit() - force any uncommitted transactions 1423470decc6SDave Kleikamp * @journal: journal to force 1424470decc6SDave Kleikamp * 1425470decc6SDave Kleikamp * For synchronous operations: force any uncommitted transactions 1426470decc6SDave Kleikamp * to disk. May seem kludgy, but it reuses all the handle batching 1427470decc6SDave Kleikamp * code in a very simple manner. 1428470decc6SDave Kleikamp */ 1429f7f4bccbSMingming Cao int jbd2_journal_force_commit(journal_t *journal) 1430470decc6SDave Kleikamp { 1431470decc6SDave Kleikamp handle_t *handle; 1432470decc6SDave Kleikamp int ret; 1433470decc6SDave Kleikamp 1434f7f4bccbSMingming Cao handle = jbd2_journal_start(journal, 1); 1435470decc6SDave Kleikamp if (IS_ERR(handle)) { 1436470decc6SDave Kleikamp ret = PTR_ERR(handle); 1437470decc6SDave Kleikamp } else { 1438470decc6SDave Kleikamp handle->h_sync = 1; 1439f7f4bccbSMingming Cao ret = jbd2_journal_stop(handle); 1440470decc6SDave Kleikamp } 1441470decc6SDave Kleikamp return ret; 1442470decc6SDave Kleikamp } 1443470decc6SDave Kleikamp 1444470decc6SDave Kleikamp /* 1445470decc6SDave Kleikamp * 1446470decc6SDave Kleikamp * List management code snippets: various functions for manipulating the 1447470decc6SDave Kleikamp * transaction buffer lists. 1448470decc6SDave Kleikamp * 1449470decc6SDave Kleikamp */ 1450470decc6SDave Kleikamp 1451470decc6SDave Kleikamp /* 1452470decc6SDave Kleikamp * Append a buffer to a transaction list, given the transaction's list head 1453470decc6SDave Kleikamp * pointer. 1454470decc6SDave Kleikamp * 1455470decc6SDave Kleikamp * j_list_lock is held. 1456470decc6SDave Kleikamp * 1457470decc6SDave Kleikamp * jbd_lock_bh_state(jh2bh(jh)) is held. 1458470decc6SDave Kleikamp */ 1459470decc6SDave Kleikamp 1460470decc6SDave Kleikamp static inline void 1461470decc6SDave Kleikamp __blist_add_buffer(struct journal_head **list, struct journal_head *jh) 1462470decc6SDave Kleikamp { 1463470decc6SDave Kleikamp if (!*list) { 1464470decc6SDave Kleikamp jh->b_tnext = jh->b_tprev = jh; 1465470decc6SDave Kleikamp *list = jh; 1466470decc6SDave Kleikamp } else { 1467470decc6SDave Kleikamp /* Insert at the tail of the list to preserve order */ 1468470decc6SDave Kleikamp struct journal_head *first = *list, *last = first->b_tprev; 1469470decc6SDave Kleikamp jh->b_tprev = last; 1470470decc6SDave Kleikamp jh->b_tnext = first; 1471470decc6SDave Kleikamp last->b_tnext = first->b_tprev = jh; 1472470decc6SDave Kleikamp } 1473470decc6SDave Kleikamp } 1474470decc6SDave Kleikamp 1475470decc6SDave Kleikamp /* 1476470decc6SDave Kleikamp * Remove a buffer from a transaction list, given the transaction's list 1477470decc6SDave Kleikamp * head pointer. 1478470decc6SDave Kleikamp * 1479470decc6SDave Kleikamp * Called with j_list_lock held, and the journal may not be locked. 1480470decc6SDave Kleikamp * 1481470decc6SDave Kleikamp * jbd_lock_bh_state(jh2bh(jh)) is held. 1482470decc6SDave Kleikamp */ 1483470decc6SDave Kleikamp 1484470decc6SDave Kleikamp static inline void 1485470decc6SDave Kleikamp __blist_del_buffer(struct journal_head **list, struct journal_head *jh) 1486470decc6SDave Kleikamp { 1487470decc6SDave Kleikamp if (*list == jh) { 1488470decc6SDave Kleikamp *list = jh->b_tnext; 1489470decc6SDave Kleikamp if (*list == jh) 1490470decc6SDave Kleikamp *list = NULL; 1491470decc6SDave Kleikamp } 1492470decc6SDave Kleikamp jh->b_tprev->b_tnext = jh->b_tnext; 1493470decc6SDave Kleikamp jh->b_tnext->b_tprev = jh->b_tprev; 1494470decc6SDave Kleikamp } 1495470decc6SDave Kleikamp 1496470decc6SDave Kleikamp /* 1497470decc6SDave Kleikamp * Remove a buffer from the appropriate transaction list. 1498470decc6SDave Kleikamp * 1499470decc6SDave Kleikamp * Note that this function can *change* the value of 150087c89c23SJan Kara * bh->b_transaction->t_buffers, t_forget, t_iobuf_list, t_shadow_list, 150187c89c23SJan Kara * t_log_list or t_reserved_list. If the caller is holding onto a copy of one 150287c89c23SJan Kara * of these pointers, it could go bad. Generally the caller needs to re-read 150387c89c23SJan Kara * the pointer from the transaction_t. 1504470decc6SDave Kleikamp * 1505470decc6SDave Kleikamp * Called under j_list_lock. The journal may not be locked. 1506470decc6SDave Kleikamp */ 1507f7f4bccbSMingming Cao void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh) 1508470decc6SDave Kleikamp { 1509470decc6SDave Kleikamp struct journal_head **list = NULL; 1510470decc6SDave Kleikamp transaction_t *transaction; 1511470decc6SDave Kleikamp struct buffer_head *bh = jh2bh(jh); 1512470decc6SDave Kleikamp 1513470decc6SDave Kleikamp J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh)); 1514470decc6SDave Kleikamp transaction = jh->b_transaction; 1515470decc6SDave Kleikamp if (transaction) 1516470decc6SDave Kleikamp assert_spin_locked(&transaction->t_journal->j_list_lock); 1517470decc6SDave Kleikamp 1518470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_jlist < BJ_Types); 1519470decc6SDave Kleikamp if (jh->b_jlist != BJ_None) 15204019191bSMingming Cao J_ASSERT_JH(jh, transaction != NULL); 1521470decc6SDave Kleikamp 1522470decc6SDave Kleikamp switch (jh->b_jlist) { 1523470decc6SDave Kleikamp case BJ_None: 1524470decc6SDave Kleikamp return; 1525470decc6SDave Kleikamp case BJ_Metadata: 1526470decc6SDave Kleikamp transaction->t_nr_buffers--; 1527470decc6SDave Kleikamp J_ASSERT_JH(jh, transaction->t_nr_buffers >= 0); 1528470decc6SDave Kleikamp list = &transaction->t_buffers; 1529470decc6SDave Kleikamp break; 1530470decc6SDave Kleikamp case BJ_Forget: 1531470decc6SDave Kleikamp list = &transaction->t_forget; 1532470decc6SDave Kleikamp break; 1533470decc6SDave Kleikamp case BJ_IO: 1534470decc6SDave Kleikamp list = &transaction->t_iobuf_list; 1535470decc6SDave Kleikamp break; 1536470decc6SDave Kleikamp case BJ_Shadow: 1537470decc6SDave Kleikamp list = &transaction->t_shadow_list; 1538470decc6SDave Kleikamp break; 1539470decc6SDave Kleikamp case BJ_LogCtl: 1540470decc6SDave Kleikamp list = &transaction->t_log_list; 1541470decc6SDave Kleikamp break; 1542470decc6SDave Kleikamp case BJ_Reserved: 1543470decc6SDave Kleikamp list = &transaction->t_reserved_list; 1544470decc6SDave Kleikamp break; 1545470decc6SDave Kleikamp } 1546470decc6SDave Kleikamp 1547470decc6SDave Kleikamp __blist_del_buffer(list, jh); 1548470decc6SDave Kleikamp jh->b_jlist = BJ_None; 1549470decc6SDave Kleikamp if (test_clear_buffer_jbddirty(bh)) 1550470decc6SDave Kleikamp mark_buffer_dirty(bh); /* Expose it to the VM */ 1551470decc6SDave Kleikamp } 1552470decc6SDave Kleikamp 1553f7f4bccbSMingming Cao void __jbd2_journal_unfile_buffer(struct journal_head *jh) 1554470decc6SDave Kleikamp { 1555f7f4bccbSMingming Cao __jbd2_journal_temp_unlink_buffer(jh); 1556470decc6SDave Kleikamp jh->b_transaction = NULL; 1557470decc6SDave Kleikamp } 1558470decc6SDave Kleikamp 1559f7f4bccbSMingming Cao void jbd2_journal_unfile_buffer(journal_t *journal, struct journal_head *jh) 1560470decc6SDave Kleikamp { 1561470decc6SDave Kleikamp jbd_lock_bh_state(jh2bh(jh)); 1562470decc6SDave Kleikamp spin_lock(&journal->j_list_lock); 1563f7f4bccbSMingming Cao __jbd2_journal_unfile_buffer(jh); 1564470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 1565470decc6SDave Kleikamp jbd_unlock_bh_state(jh2bh(jh)); 1566470decc6SDave Kleikamp } 1567470decc6SDave Kleikamp 1568470decc6SDave Kleikamp /* 1569f7f4bccbSMingming Cao * Called from jbd2_journal_try_to_free_buffers(). 1570470decc6SDave Kleikamp * 1571470decc6SDave Kleikamp * Called under jbd_lock_bh_state(bh) 1572470decc6SDave Kleikamp */ 1573470decc6SDave Kleikamp static void 1574470decc6SDave Kleikamp __journal_try_to_free_buffer(journal_t *journal, struct buffer_head *bh) 1575470decc6SDave Kleikamp { 1576470decc6SDave Kleikamp struct journal_head *jh; 1577470decc6SDave Kleikamp 1578470decc6SDave Kleikamp jh = bh2jh(bh); 1579470decc6SDave Kleikamp 1580470decc6SDave Kleikamp if (buffer_locked(bh) || buffer_dirty(bh)) 1581470decc6SDave Kleikamp goto out; 1582470decc6SDave Kleikamp 15834019191bSMingming Cao if (jh->b_next_transaction != NULL) 1584470decc6SDave Kleikamp goto out; 1585470decc6SDave Kleikamp 1586470decc6SDave Kleikamp spin_lock(&journal->j_list_lock); 158787c89c23SJan Kara if (jh->b_cp_transaction != NULL && jh->b_transaction == NULL) { 1588470decc6SDave Kleikamp /* written-back checkpointed metadata buffer */ 1589470decc6SDave Kleikamp if (jh->b_jlist == BJ_None) { 1590470decc6SDave Kleikamp JBUFFER_TRACE(jh, "remove from checkpoint list"); 1591f7f4bccbSMingming Cao __jbd2_journal_remove_checkpoint(jh); 1592f7f4bccbSMingming Cao jbd2_journal_remove_journal_head(bh); 1593470decc6SDave Kleikamp __brelse(bh); 1594470decc6SDave Kleikamp } 1595470decc6SDave Kleikamp } 1596470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 1597470decc6SDave Kleikamp out: 1598470decc6SDave Kleikamp return; 1599470decc6SDave Kleikamp } 1600470decc6SDave Kleikamp 1601470decc6SDave Kleikamp /** 1602f7f4bccbSMingming Cao * int jbd2_journal_try_to_free_buffers() - try to free page buffers. 1603470decc6SDave Kleikamp * @journal: journal for operation 1604470decc6SDave Kleikamp * @page: to try and free 1605530576bbSMingming Cao * @gfp_mask: we use the mask to detect how hard should we try to release 1606530576bbSMingming Cao * buffers. If __GFP_WAIT and __GFP_FS is set, we wait for commit code to 1607530576bbSMingming Cao * release the buffers. 1608470decc6SDave Kleikamp * 1609470decc6SDave Kleikamp * 1610470decc6SDave Kleikamp * For all the buffers on this page, 1611470decc6SDave Kleikamp * if they are fully written out ordered data, move them onto BUF_CLEAN 1612470decc6SDave Kleikamp * so try_to_free_buffers() can reap them. 1613470decc6SDave Kleikamp * 1614470decc6SDave Kleikamp * This function returns non-zero if we wish try_to_free_buffers() 1615470decc6SDave Kleikamp * to be called. We do this if the page is releasable by try_to_free_buffers(). 1616470decc6SDave Kleikamp * We also do it if the page has locked or dirty buffers and the caller wants 1617470decc6SDave Kleikamp * us to perform sync or async writeout. 1618470decc6SDave Kleikamp * 1619470decc6SDave Kleikamp * This complicates JBD locking somewhat. We aren't protected by the 1620470decc6SDave Kleikamp * BKL here. We wish to remove the buffer from its committing or 1621f7f4bccbSMingming Cao * running transaction's ->t_datalist via __jbd2_journal_unfile_buffer. 1622470decc6SDave Kleikamp * 1623470decc6SDave Kleikamp * This may *change* the value of transaction_t->t_datalist, so anyone 1624470decc6SDave Kleikamp * who looks at t_datalist needs to lock against this function. 1625470decc6SDave Kleikamp * 1626f7f4bccbSMingming Cao * Even worse, someone may be doing a jbd2_journal_dirty_data on this 1627f7f4bccbSMingming Cao * buffer. So we need to lock against that. jbd2_journal_dirty_data() 1628470decc6SDave Kleikamp * will come out of the lock with the buffer dirty, which makes it 1629470decc6SDave Kleikamp * ineligible for release here. 1630470decc6SDave Kleikamp * 1631470decc6SDave Kleikamp * Who else is affected by this? hmm... Really the only contender 1632470decc6SDave Kleikamp * is do_get_write_access() - it could be looking at the buffer while 1633470decc6SDave Kleikamp * journal_try_to_free_buffer() is changing its state. But that 1634470decc6SDave Kleikamp * cannot happen because we never reallocate freed data as metadata 1635470decc6SDave Kleikamp * while the data is part of a transaction. Yes? 1636530576bbSMingming Cao * 1637530576bbSMingming Cao * Return 0 on failure, 1 on success 1638470decc6SDave Kleikamp */ 1639f7f4bccbSMingming Cao int jbd2_journal_try_to_free_buffers(journal_t *journal, 1640530576bbSMingming Cao struct page *page, gfp_t gfp_mask) 1641470decc6SDave Kleikamp { 1642470decc6SDave Kleikamp struct buffer_head *head; 1643470decc6SDave Kleikamp struct buffer_head *bh; 1644470decc6SDave Kleikamp int ret = 0; 1645470decc6SDave Kleikamp 1646470decc6SDave Kleikamp J_ASSERT(PageLocked(page)); 1647470decc6SDave Kleikamp 1648470decc6SDave Kleikamp head = page_buffers(page); 1649470decc6SDave Kleikamp bh = head; 1650470decc6SDave Kleikamp do { 1651470decc6SDave Kleikamp struct journal_head *jh; 1652470decc6SDave Kleikamp 1653470decc6SDave Kleikamp /* 1654470decc6SDave Kleikamp * We take our own ref against the journal_head here to avoid 1655470decc6SDave Kleikamp * having to add tons of locking around each instance of 1656530576bbSMingming Cao * jbd2_journal_remove_journal_head() and 1657530576bbSMingming Cao * jbd2_journal_put_journal_head(). 1658470decc6SDave Kleikamp */ 1659f7f4bccbSMingming Cao jh = jbd2_journal_grab_journal_head(bh); 1660470decc6SDave Kleikamp if (!jh) 1661470decc6SDave Kleikamp continue; 1662470decc6SDave Kleikamp 1663470decc6SDave Kleikamp jbd_lock_bh_state(bh); 1664470decc6SDave Kleikamp __journal_try_to_free_buffer(journal, bh); 1665f7f4bccbSMingming Cao jbd2_journal_put_journal_head(jh); 1666470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 1667470decc6SDave Kleikamp if (buffer_jbd(bh)) 1668470decc6SDave Kleikamp goto busy; 1669470decc6SDave Kleikamp } while ((bh = bh->b_this_page) != head); 1670530576bbSMingming Cao 1671470decc6SDave Kleikamp ret = try_to_free_buffers(page); 1672530576bbSMingming Cao 1673470decc6SDave Kleikamp busy: 1674470decc6SDave Kleikamp return ret; 1675470decc6SDave Kleikamp } 1676470decc6SDave Kleikamp 1677470decc6SDave Kleikamp /* 1678470decc6SDave Kleikamp * This buffer is no longer needed. If it is on an older transaction's 1679470decc6SDave Kleikamp * checkpoint list we need to record it on this transaction's forget list 1680470decc6SDave Kleikamp * to pin this buffer (and hence its checkpointing transaction) down until 1681470decc6SDave Kleikamp * this transaction commits. If the buffer isn't on a checkpoint list, we 1682470decc6SDave Kleikamp * release it. 1683470decc6SDave Kleikamp * Returns non-zero if JBD no longer has an interest in the buffer. 1684470decc6SDave Kleikamp * 1685470decc6SDave Kleikamp * Called under j_list_lock. 1686470decc6SDave Kleikamp * 1687470decc6SDave Kleikamp * Called under jbd_lock_bh_state(bh). 1688470decc6SDave Kleikamp */ 1689470decc6SDave Kleikamp static int __dispose_buffer(struct journal_head *jh, transaction_t *transaction) 1690470decc6SDave Kleikamp { 1691470decc6SDave Kleikamp int may_free = 1; 1692470decc6SDave Kleikamp struct buffer_head *bh = jh2bh(jh); 1693470decc6SDave Kleikamp 1694f7f4bccbSMingming Cao __jbd2_journal_unfile_buffer(jh); 1695470decc6SDave Kleikamp 1696470decc6SDave Kleikamp if (jh->b_cp_transaction) { 1697470decc6SDave Kleikamp JBUFFER_TRACE(jh, "on running+cp transaction"); 1698f91d1d04SJan Kara /* 1699f91d1d04SJan Kara * We don't want to write the buffer anymore, clear the 1700f91d1d04SJan Kara * bit so that we don't confuse checks in 1701f91d1d04SJan Kara * __journal_file_buffer 1702f91d1d04SJan Kara */ 1703f91d1d04SJan Kara clear_buffer_dirty(bh); 1704f7f4bccbSMingming Cao __jbd2_journal_file_buffer(jh, transaction, BJ_Forget); 1705470decc6SDave Kleikamp may_free = 0; 1706470decc6SDave Kleikamp } else { 1707470decc6SDave Kleikamp JBUFFER_TRACE(jh, "on running transaction"); 1708f7f4bccbSMingming Cao jbd2_journal_remove_journal_head(bh); 1709470decc6SDave Kleikamp __brelse(bh); 1710470decc6SDave Kleikamp } 1711470decc6SDave Kleikamp return may_free; 1712470decc6SDave Kleikamp } 1713470decc6SDave Kleikamp 1714470decc6SDave Kleikamp /* 1715f7f4bccbSMingming Cao * jbd2_journal_invalidatepage 1716470decc6SDave Kleikamp * 1717470decc6SDave Kleikamp * This code is tricky. It has a number of cases to deal with. 1718470decc6SDave Kleikamp * 1719470decc6SDave Kleikamp * There are two invariants which this code relies on: 1720470decc6SDave Kleikamp * 1721470decc6SDave Kleikamp * i_size must be updated on disk before we start calling invalidatepage on the 1722470decc6SDave Kleikamp * data. 1723470decc6SDave Kleikamp * 1724470decc6SDave Kleikamp * This is done in ext3 by defining an ext3_setattr method which 1725470decc6SDave Kleikamp * updates i_size before truncate gets going. By maintaining this 1726470decc6SDave Kleikamp * invariant, we can be sure that it is safe to throw away any buffers 1727470decc6SDave Kleikamp * attached to the current transaction: once the transaction commits, 1728470decc6SDave Kleikamp * we know that the data will not be needed. 1729470decc6SDave Kleikamp * 1730470decc6SDave Kleikamp * Note however that we can *not* throw away data belonging to the 1731470decc6SDave Kleikamp * previous, committing transaction! 1732470decc6SDave Kleikamp * 1733470decc6SDave Kleikamp * Any disk blocks which *are* part of the previous, committing 1734470decc6SDave Kleikamp * transaction (and which therefore cannot be discarded immediately) are 1735470decc6SDave Kleikamp * not going to be reused in the new running transaction 1736470decc6SDave Kleikamp * 1737470decc6SDave Kleikamp * The bitmap committed_data images guarantee this: any block which is 1738470decc6SDave Kleikamp * allocated in one transaction and removed in the next will be marked 1739470decc6SDave Kleikamp * as in-use in the committed_data bitmap, so cannot be reused until 1740470decc6SDave Kleikamp * the next transaction to delete the block commits. This means that 1741470decc6SDave Kleikamp * leaving committing buffers dirty is quite safe: the disk blocks 1742470decc6SDave Kleikamp * cannot be reallocated to a different file and so buffer aliasing is 1743470decc6SDave Kleikamp * not possible. 1744470decc6SDave Kleikamp * 1745470decc6SDave Kleikamp * 1746470decc6SDave Kleikamp * The above applies mainly to ordered data mode. In writeback mode we 1747470decc6SDave Kleikamp * don't make guarantees about the order in which data hits disk --- in 1748470decc6SDave Kleikamp * particular we don't guarantee that new dirty data is flushed before 1749470decc6SDave Kleikamp * transaction commit --- so it is always safe just to discard data 1750470decc6SDave Kleikamp * immediately in that mode. --sct 1751470decc6SDave Kleikamp */ 1752470decc6SDave Kleikamp 1753470decc6SDave Kleikamp /* 1754470decc6SDave Kleikamp * The journal_unmap_buffer helper function returns zero if the buffer 1755470decc6SDave Kleikamp * concerned remains pinned as an anonymous buffer belonging to an older 1756470decc6SDave Kleikamp * transaction. 1757470decc6SDave Kleikamp * 1758470decc6SDave Kleikamp * We're outside-transaction here. Either or both of j_running_transaction 1759470decc6SDave Kleikamp * and j_committing_transaction may be NULL. 1760470decc6SDave Kleikamp */ 1761470decc6SDave Kleikamp static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh) 1762470decc6SDave Kleikamp { 1763470decc6SDave Kleikamp transaction_t *transaction; 1764470decc6SDave Kleikamp struct journal_head *jh; 1765470decc6SDave Kleikamp int may_free = 1; 1766470decc6SDave Kleikamp int ret; 1767470decc6SDave Kleikamp 1768470decc6SDave Kleikamp BUFFER_TRACE(bh, "entry"); 1769470decc6SDave Kleikamp 1770470decc6SDave Kleikamp /* 1771470decc6SDave Kleikamp * It is safe to proceed here without the j_list_lock because the 1772470decc6SDave Kleikamp * buffers cannot be stolen by try_to_free_buffers as long as we are 1773470decc6SDave Kleikamp * holding the page lock. --sct 1774470decc6SDave Kleikamp */ 1775470decc6SDave Kleikamp 1776470decc6SDave Kleikamp if (!buffer_jbd(bh)) 1777470decc6SDave Kleikamp goto zap_buffer_unlocked; 1778470decc6SDave Kleikamp 177987c89c23SJan Kara /* OK, we have data buffer in journaled mode */ 1780a931da6aSTheodore Ts'o write_lock(&journal->j_state_lock); 1781470decc6SDave Kleikamp jbd_lock_bh_state(bh); 1782470decc6SDave Kleikamp spin_lock(&journal->j_list_lock); 1783470decc6SDave Kleikamp 1784f7f4bccbSMingming Cao jh = jbd2_journal_grab_journal_head(bh); 1785470decc6SDave Kleikamp if (!jh) 1786470decc6SDave Kleikamp goto zap_buffer_no_jh; 1787470decc6SDave Kleikamp 1788ba869023Sdingdinghua /* 1789ba869023Sdingdinghua * We cannot remove the buffer from checkpoint lists until the 1790ba869023Sdingdinghua * transaction adding inode to orphan list (let's call it T) 1791ba869023Sdingdinghua * is committed. Otherwise if the transaction changing the 1792ba869023Sdingdinghua * buffer would be cleaned from the journal before T is 1793ba869023Sdingdinghua * committed, a crash will cause that the correct contents of 1794ba869023Sdingdinghua * the buffer will be lost. On the other hand we have to 1795ba869023Sdingdinghua * clear the buffer dirty bit at latest at the moment when the 1796ba869023Sdingdinghua * transaction marking the buffer as freed in the filesystem 1797ba869023Sdingdinghua * structures is committed because from that moment on the 1798ba869023Sdingdinghua * buffer can be reallocated and used by a different page. 1799ba869023Sdingdinghua * Since the block hasn't been freed yet but the inode has 1800ba869023Sdingdinghua * already been added to orphan list, it is safe for us to add 1801ba869023Sdingdinghua * the buffer to BJ_Forget list of the newest transaction. 1802ba869023Sdingdinghua */ 1803470decc6SDave Kleikamp transaction = jh->b_transaction; 1804470decc6SDave Kleikamp if (transaction == NULL) { 1805470decc6SDave Kleikamp /* First case: not on any transaction. If it 1806470decc6SDave Kleikamp * has no checkpoint link, then we can zap it: 1807470decc6SDave Kleikamp * it's a writeback-mode buffer so we don't care 1808470decc6SDave Kleikamp * if it hits disk safely. */ 1809470decc6SDave Kleikamp if (!jh->b_cp_transaction) { 1810470decc6SDave Kleikamp JBUFFER_TRACE(jh, "not on any transaction: zap"); 1811470decc6SDave Kleikamp goto zap_buffer; 1812470decc6SDave Kleikamp } 1813470decc6SDave Kleikamp 1814470decc6SDave Kleikamp if (!buffer_dirty(bh)) { 1815470decc6SDave Kleikamp /* bdflush has written it. We can drop it now */ 1816470decc6SDave Kleikamp goto zap_buffer; 1817470decc6SDave Kleikamp } 1818470decc6SDave Kleikamp 1819470decc6SDave Kleikamp /* OK, it must be in the journal but still not 1820470decc6SDave Kleikamp * written fully to disk: it's metadata or 1821470decc6SDave Kleikamp * journaled data... */ 1822470decc6SDave Kleikamp 1823470decc6SDave Kleikamp if (journal->j_running_transaction) { 1824470decc6SDave Kleikamp /* ... and once the current transaction has 1825470decc6SDave Kleikamp * committed, the buffer won't be needed any 1826470decc6SDave Kleikamp * longer. */ 1827470decc6SDave Kleikamp JBUFFER_TRACE(jh, "checkpointed: add to BJ_Forget"); 1828470decc6SDave Kleikamp ret = __dispose_buffer(jh, 1829470decc6SDave Kleikamp journal->j_running_transaction); 1830f7f4bccbSMingming Cao jbd2_journal_put_journal_head(jh); 1831470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 1832470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 1833a931da6aSTheodore Ts'o write_unlock(&journal->j_state_lock); 1834470decc6SDave Kleikamp return ret; 1835470decc6SDave Kleikamp } else { 1836470decc6SDave Kleikamp /* There is no currently-running transaction. So the 1837470decc6SDave Kleikamp * orphan record which we wrote for this file must have 1838470decc6SDave Kleikamp * passed into commit. We must attach this buffer to 1839470decc6SDave Kleikamp * the committing transaction, if it exists. */ 1840470decc6SDave Kleikamp if (journal->j_committing_transaction) { 1841470decc6SDave Kleikamp JBUFFER_TRACE(jh, "give to committing trans"); 1842470decc6SDave Kleikamp ret = __dispose_buffer(jh, 1843470decc6SDave Kleikamp journal->j_committing_transaction); 1844f7f4bccbSMingming Cao jbd2_journal_put_journal_head(jh); 1845470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 1846470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 1847a931da6aSTheodore Ts'o write_unlock(&journal->j_state_lock); 1848470decc6SDave Kleikamp return ret; 1849470decc6SDave Kleikamp } else { 1850470decc6SDave Kleikamp /* The orphan record's transaction has 1851470decc6SDave Kleikamp * committed. We can cleanse this buffer */ 1852470decc6SDave Kleikamp clear_buffer_jbddirty(bh); 1853470decc6SDave Kleikamp goto zap_buffer; 1854470decc6SDave Kleikamp } 1855470decc6SDave Kleikamp } 1856470decc6SDave Kleikamp } else if (transaction == journal->j_committing_transaction) { 18579b57988dSEric Sandeen JBUFFER_TRACE(jh, "on committing transaction"); 1858470decc6SDave Kleikamp /* 1859ba869023Sdingdinghua * The buffer is committing, we simply cannot touch 1860ba869023Sdingdinghua * it. So we just set j_next_transaction to the 1861ba869023Sdingdinghua * running transaction (if there is one) and mark 1862ba869023Sdingdinghua * buffer as freed so that commit code knows it should 1863ba869023Sdingdinghua * clear dirty bits when it is done with the buffer. 1864ba869023Sdingdinghua */ 1865470decc6SDave Kleikamp set_buffer_freed(bh); 1866ba869023Sdingdinghua if (journal->j_running_transaction && buffer_jbddirty(bh)) 1867ba869023Sdingdinghua jh->b_next_transaction = journal->j_running_transaction; 1868f7f4bccbSMingming Cao jbd2_journal_put_journal_head(jh); 1869470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 1870470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 1871a931da6aSTheodore Ts'o write_unlock(&journal->j_state_lock); 1872470decc6SDave Kleikamp return 0; 1873470decc6SDave Kleikamp } else { 1874470decc6SDave Kleikamp /* Good, the buffer belongs to the running transaction. 1875470decc6SDave Kleikamp * We are writing our own transaction's data, not any 1876470decc6SDave Kleikamp * previous one's, so it is safe to throw it away 1877470decc6SDave Kleikamp * (remember that we expect the filesystem to have set 1878470decc6SDave Kleikamp * i_size already for this truncate so recovery will not 1879470decc6SDave Kleikamp * expose the disk blocks we are discarding here.) */ 1880470decc6SDave Kleikamp J_ASSERT_JH(jh, transaction == journal->j_running_transaction); 18819b57988dSEric Sandeen JBUFFER_TRACE(jh, "on running transaction"); 1882470decc6SDave Kleikamp may_free = __dispose_buffer(jh, transaction); 1883470decc6SDave Kleikamp } 1884470decc6SDave Kleikamp 1885470decc6SDave Kleikamp zap_buffer: 1886f7f4bccbSMingming Cao jbd2_journal_put_journal_head(jh); 1887470decc6SDave Kleikamp zap_buffer_no_jh: 1888470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 1889470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 1890a931da6aSTheodore Ts'o write_unlock(&journal->j_state_lock); 1891470decc6SDave Kleikamp zap_buffer_unlocked: 1892470decc6SDave Kleikamp clear_buffer_dirty(bh); 1893470decc6SDave Kleikamp J_ASSERT_BH(bh, !buffer_jbddirty(bh)); 1894470decc6SDave Kleikamp clear_buffer_mapped(bh); 1895470decc6SDave Kleikamp clear_buffer_req(bh); 1896470decc6SDave Kleikamp clear_buffer_new(bh); 1897470decc6SDave Kleikamp bh->b_bdev = NULL; 1898470decc6SDave Kleikamp return may_free; 1899470decc6SDave Kleikamp } 1900470decc6SDave Kleikamp 1901470decc6SDave Kleikamp /** 1902f7f4bccbSMingming Cao * void jbd2_journal_invalidatepage() 1903470decc6SDave Kleikamp * @journal: journal to use for flush... 1904470decc6SDave Kleikamp * @page: page to flush 1905470decc6SDave Kleikamp * @offset: length of page to invalidate. 1906470decc6SDave Kleikamp * 1907470decc6SDave Kleikamp * Reap page buffers containing data after offset in page. 1908470decc6SDave Kleikamp * 1909470decc6SDave Kleikamp */ 1910f7f4bccbSMingming Cao void jbd2_journal_invalidatepage(journal_t *journal, 1911470decc6SDave Kleikamp struct page *page, 1912470decc6SDave Kleikamp unsigned long offset) 1913470decc6SDave Kleikamp { 1914470decc6SDave Kleikamp struct buffer_head *head, *bh, *next; 1915470decc6SDave Kleikamp unsigned int curr_off = 0; 1916470decc6SDave Kleikamp int may_free = 1; 1917470decc6SDave Kleikamp 1918470decc6SDave Kleikamp if (!PageLocked(page)) 1919470decc6SDave Kleikamp BUG(); 1920470decc6SDave Kleikamp if (!page_has_buffers(page)) 1921470decc6SDave Kleikamp return; 1922470decc6SDave Kleikamp 1923470decc6SDave Kleikamp /* We will potentially be playing with lists other than just the 1924470decc6SDave Kleikamp * data lists (especially for journaled data mode), so be 1925470decc6SDave Kleikamp * cautious in our locking. */ 1926470decc6SDave Kleikamp 1927470decc6SDave Kleikamp head = bh = page_buffers(page); 1928470decc6SDave Kleikamp do { 1929470decc6SDave Kleikamp unsigned int next_off = curr_off + bh->b_size; 1930470decc6SDave Kleikamp next = bh->b_this_page; 1931470decc6SDave Kleikamp 1932470decc6SDave Kleikamp if (offset <= curr_off) { 1933470decc6SDave Kleikamp /* This block is wholly outside the truncation point */ 1934470decc6SDave Kleikamp lock_buffer(bh); 1935470decc6SDave Kleikamp may_free &= journal_unmap_buffer(journal, bh); 1936470decc6SDave Kleikamp unlock_buffer(bh); 1937470decc6SDave Kleikamp } 1938470decc6SDave Kleikamp curr_off = next_off; 1939470decc6SDave Kleikamp bh = next; 1940470decc6SDave Kleikamp 1941470decc6SDave Kleikamp } while (bh != head); 1942470decc6SDave Kleikamp 1943470decc6SDave Kleikamp if (!offset) { 1944470decc6SDave Kleikamp if (may_free && try_to_free_buffers(page)) 1945470decc6SDave Kleikamp J_ASSERT(!page_has_buffers(page)); 1946470decc6SDave Kleikamp } 1947470decc6SDave Kleikamp } 1948470decc6SDave Kleikamp 1949470decc6SDave Kleikamp /* 1950470decc6SDave Kleikamp * File a buffer on the given transaction list. 1951470decc6SDave Kleikamp */ 1952f7f4bccbSMingming Cao void __jbd2_journal_file_buffer(struct journal_head *jh, 1953470decc6SDave Kleikamp transaction_t *transaction, int jlist) 1954470decc6SDave Kleikamp { 1955470decc6SDave Kleikamp struct journal_head **list = NULL; 1956470decc6SDave Kleikamp int was_dirty = 0; 1957470decc6SDave Kleikamp struct buffer_head *bh = jh2bh(jh); 1958470decc6SDave Kleikamp 1959470decc6SDave Kleikamp J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh)); 1960470decc6SDave Kleikamp assert_spin_locked(&transaction->t_journal->j_list_lock); 1961470decc6SDave Kleikamp 1962470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_jlist < BJ_Types); 1963470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_transaction == transaction || 19644019191bSMingming Cao jh->b_transaction == NULL); 1965470decc6SDave Kleikamp 1966470decc6SDave Kleikamp if (jh->b_transaction && jh->b_jlist == jlist) 1967470decc6SDave Kleikamp return; 1968470decc6SDave Kleikamp 1969470decc6SDave Kleikamp if (jlist == BJ_Metadata || jlist == BJ_Reserved || 1970470decc6SDave Kleikamp jlist == BJ_Shadow || jlist == BJ_Forget) { 1971f91d1d04SJan Kara /* 1972f91d1d04SJan Kara * For metadata buffers, we track dirty bit in buffer_jbddirty 1973f91d1d04SJan Kara * instead of buffer_dirty. We should not see a dirty bit set 1974f91d1d04SJan Kara * here because we clear it in do_get_write_access but e.g. 1975f91d1d04SJan Kara * tune2fs can modify the sb and set the dirty bit at any time 1976f91d1d04SJan Kara * so we try to gracefully handle that. 1977f91d1d04SJan Kara */ 1978f91d1d04SJan Kara if (buffer_dirty(bh)) 1979f91d1d04SJan Kara warn_dirty_buffer(bh); 1980470decc6SDave Kleikamp if (test_clear_buffer_dirty(bh) || 1981470decc6SDave Kleikamp test_clear_buffer_jbddirty(bh)) 1982470decc6SDave Kleikamp was_dirty = 1; 1983470decc6SDave Kleikamp } 1984470decc6SDave Kleikamp 1985470decc6SDave Kleikamp if (jh->b_transaction) 1986f7f4bccbSMingming Cao __jbd2_journal_temp_unlink_buffer(jh); 1987470decc6SDave Kleikamp jh->b_transaction = transaction; 1988470decc6SDave Kleikamp 1989470decc6SDave Kleikamp switch (jlist) { 1990470decc6SDave Kleikamp case BJ_None: 1991470decc6SDave Kleikamp J_ASSERT_JH(jh, !jh->b_committed_data); 1992470decc6SDave Kleikamp J_ASSERT_JH(jh, !jh->b_frozen_data); 1993470decc6SDave Kleikamp return; 1994470decc6SDave Kleikamp case BJ_Metadata: 1995470decc6SDave Kleikamp transaction->t_nr_buffers++; 1996470decc6SDave Kleikamp list = &transaction->t_buffers; 1997470decc6SDave Kleikamp break; 1998470decc6SDave Kleikamp case BJ_Forget: 1999470decc6SDave Kleikamp list = &transaction->t_forget; 2000470decc6SDave Kleikamp break; 2001470decc6SDave Kleikamp case BJ_IO: 2002470decc6SDave Kleikamp list = &transaction->t_iobuf_list; 2003470decc6SDave Kleikamp break; 2004470decc6SDave Kleikamp case BJ_Shadow: 2005470decc6SDave Kleikamp list = &transaction->t_shadow_list; 2006470decc6SDave Kleikamp break; 2007470decc6SDave Kleikamp case BJ_LogCtl: 2008470decc6SDave Kleikamp list = &transaction->t_log_list; 2009470decc6SDave Kleikamp break; 2010470decc6SDave Kleikamp case BJ_Reserved: 2011470decc6SDave Kleikamp list = &transaction->t_reserved_list; 2012470decc6SDave Kleikamp break; 2013470decc6SDave Kleikamp } 2014470decc6SDave Kleikamp 2015470decc6SDave Kleikamp __blist_add_buffer(list, jh); 2016470decc6SDave Kleikamp jh->b_jlist = jlist; 2017470decc6SDave Kleikamp 2018470decc6SDave Kleikamp if (was_dirty) 2019470decc6SDave Kleikamp set_buffer_jbddirty(bh); 2020470decc6SDave Kleikamp } 2021470decc6SDave Kleikamp 2022f7f4bccbSMingming Cao void jbd2_journal_file_buffer(struct journal_head *jh, 2023470decc6SDave Kleikamp transaction_t *transaction, int jlist) 2024470decc6SDave Kleikamp { 2025470decc6SDave Kleikamp jbd_lock_bh_state(jh2bh(jh)); 2026470decc6SDave Kleikamp spin_lock(&transaction->t_journal->j_list_lock); 2027f7f4bccbSMingming Cao __jbd2_journal_file_buffer(jh, transaction, jlist); 2028470decc6SDave Kleikamp spin_unlock(&transaction->t_journal->j_list_lock); 2029470decc6SDave Kleikamp jbd_unlock_bh_state(jh2bh(jh)); 2030470decc6SDave Kleikamp } 2031470decc6SDave Kleikamp 2032470decc6SDave Kleikamp /* 2033470decc6SDave Kleikamp * Remove a buffer from its current buffer list in preparation for 2034470decc6SDave Kleikamp * dropping it from its current transaction entirely. If the buffer has 2035470decc6SDave Kleikamp * already started to be used by a subsequent transaction, refile the 2036470decc6SDave Kleikamp * buffer on that transaction's metadata list. 2037470decc6SDave Kleikamp * 2038470decc6SDave Kleikamp * Called under journal->j_list_lock 2039470decc6SDave Kleikamp * 2040470decc6SDave Kleikamp * Called under jbd_lock_bh_state(jh2bh(jh)) 2041470decc6SDave Kleikamp */ 2042f7f4bccbSMingming Cao void __jbd2_journal_refile_buffer(struct journal_head *jh) 2043470decc6SDave Kleikamp { 2044ba869023Sdingdinghua int was_dirty, jlist; 2045470decc6SDave Kleikamp struct buffer_head *bh = jh2bh(jh); 2046470decc6SDave Kleikamp 2047470decc6SDave Kleikamp J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh)); 2048470decc6SDave Kleikamp if (jh->b_transaction) 2049470decc6SDave Kleikamp assert_spin_locked(&jh->b_transaction->t_journal->j_list_lock); 2050470decc6SDave Kleikamp 2051470decc6SDave Kleikamp /* If the buffer is now unused, just drop it. */ 2052470decc6SDave Kleikamp if (jh->b_next_transaction == NULL) { 2053f7f4bccbSMingming Cao __jbd2_journal_unfile_buffer(jh); 2054470decc6SDave Kleikamp return; 2055470decc6SDave Kleikamp } 2056470decc6SDave Kleikamp 2057470decc6SDave Kleikamp /* 2058470decc6SDave Kleikamp * It has been modified by a later transaction: add it to the new 2059470decc6SDave Kleikamp * transaction's metadata list. 2060470decc6SDave Kleikamp */ 2061470decc6SDave Kleikamp 2062470decc6SDave Kleikamp was_dirty = test_clear_buffer_jbddirty(bh); 2063f7f4bccbSMingming Cao __jbd2_journal_temp_unlink_buffer(jh); 2064470decc6SDave Kleikamp jh->b_transaction = jh->b_next_transaction; 2065470decc6SDave Kleikamp jh->b_next_transaction = NULL; 2066ba869023Sdingdinghua if (buffer_freed(bh)) 2067ba869023Sdingdinghua jlist = BJ_Forget; 2068ba869023Sdingdinghua else if (jh->b_modified) 2069ba869023Sdingdinghua jlist = BJ_Metadata; 2070ba869023Sdingdinghua else 2071ba869023Sdingdinghua jlist = BJ_Reserved; 2072ba869023Sdingdinghua __jbd2_journal_file_buffer(jh, jh->b_transaction, jlist); 2073470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_transaction->t_state == T_RUNNING); 2074470decc6SDave Kleikamp 2075470decc6SDave Kleikamp if (was_dirty) 2076470decc6SDave Kleikamp set_buffer_jbddirty(bh); 2077470decc6SDave Kleikamp } 2078470decc6SDave Kleikamp 2079470decc6SDave Kleikamp /* 2080470decc6SDave Kleikamp * For the unlocked version of this call, also make sure that any 2081470decc6SDave Kleikamp * hanging journal_head is cleaned up if necessary. 2082470decc6SDave Kleikamp * 2083f7f4bccbSMingming Cao * __jbd2_journal_refile_buffer is usually called as part of a single locked 2084470decc6SDave Kleikamp * operation on a buffer_head, in which the caller is probably going to 2085470decc6SDave Kleikamp * be hooking the journal_head onto other lists. In that case it is up 2086470decc6SDave Kleikamp * to the caller to remove the journal_head if necessary. For the 2087f7f4bccbSMingming Cao * unlocked jbd2_journal_refile_buffer call, the caller isn't going to be 2088470decc6SDave Kleikamp * doing anything else to the buffer so we need to do the cleanup 2089470decc6SDave Kleikamp * ourselves to avoid a jh leak. 2090470decc6SDave Kleikamp * 2091470decc6SDave Kleikamp * *** The journal_head may be freed by this call! *** 2092470decc6SDave Kleikamp */ 2093f7f4bccbSMingming Cao void jbd2_journal_refile_buffer(journal_t *journal, struct journal_head *jh) 2094470decc6SDave Kleikamp { 2095470decc6SDave Kleikamp struct buffer_head *bh = jh2bh(jh); 2096470decc6SDave Kleikamp 2097470decc6SDave Kleikamp jbd_lock_bh_state(bh); 2098470decc6SDave Kleikamp spin_lock(&journal->j_list_lock); 2099470decc6SDave Kleikamp 2100f7f4bccbSMingming Cao __jbd2_journal_refile_buffer(jh); 2101470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 2102f7f4bccbSMingming Cao jbd2_journal_remove_journal_head(bh); 2103470decc6SDave Kleikamp 2104470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 2105470decc6SDave Kleikamp __brelse(bh); 2106470decc6SDave Kleikamp } 2107c851ed54SJan Kara 2108c851ed54SJan Kara /* 2109c851ed54SJan Kara * File inode in the inode list of the handle's transaction 2110c851ed54SJan Kara */ 2111c851ed54SJan Kara int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *jinode) 2112c851ed54SJan Kara { 2113c851ed54SJan Kara transaction_t *transaction = handle->h_transaction; 2114c851ed54SJan Kara journal_t *journal = transaction->t_journal; 2115c851ed54SJan Kara 2116c851ed54SJan Kara if (is_handle_aborted(handle)) 2117c851ed54SJan Kara return -EIO; 2118c851ed54SJan Kara 2119c851ed54SJan Kara jbd_debug(4, "Adding inode %lu, tid:%d\n", jinode->i_vfs_inode->i_ino, 2120c851ed54SJan Kara transaction->t_tid); 2121c851ed54SJan Kara 2122c851ed54SJan Kara /* 2123c851ed54SJan Kara * First check whether inode isn't already on the transaction's 2124c851ed54SJan Kara * lists without taking the lock. Note that this check is safe 2125c851ed54SJan Kara * without the lock as we cannot race with somebody removing inode 2126c851ed54SJan Kara * from the transaction. The reason is that we remove inode from the 2127c851ed54SJan Kara * transaction only in journal_release_jbd_inode() and when we commit 2128c851ed54SJan Kara * the transaction. We are guarded from the first case by holding 2129c851ed54SJan Kara * a reference to the inode. We are safe against the second case 2130c851ed54SJan Kara * because if jinode->i_transaction == transaction, commit code 2131c851ed54SJan Kara * cannot touch the transaction because we hold reference to it, 2132c851ed54SJan Kara * and if jinode->i_next_transaction == transaction, commit code 2133c851ed54SJan Kara * will only file the inode where we want it. 2134c851ed54SJan Kara */ 2135c851ed54SJan Kara if (jinode->i_transaction == transaction || 2136c851ed54SJan Kara jinode->i_next_transaction == transaction) 2137c851ed54SJan Kara return 0; 2138c851ed54SJan Kara 2139c851ed54SJan Kara spin_lock(&journal->j_list_lock); 2140c851ed54SJan Kara 2141c851ed54SJan Kara if (jinode->i_transaction == transaction || 2142c851ed54SJan Kara jinode->i_next_transaction == transaction) 2143c851ed54SJan Kara goto done; 2144c851ed54SJan Kara 2145c851ed54SJan Kara /* On some different transaction's list - should be 2146c851ed54SJan Kara * the committing one */ 2147c851ed54SJan Kara if (jinode->i_transaction) { 2148c851ed54SJan Kara J_ASSERT(jinode->i_next_transaction == NULL); 2149c851ed54SJan Kara J_ASSERT(jinode->i_transaction == 2150c851ed54SJan Kara journal->j_committing_transaction); 2151c851ed54SJan Kara jinode->i_next_transaction = transaction; 2152c851ed54SJan Kara goto done; 2153c851ed54SJan Kara } 2154c851ed54SJan Kara /* Not on any transaction list... */ 2155c851ed54SJan Kara J_ASSERT(!jinode->i_next_transaction); 2156c851ed54SJan Kara jinode->i_transaction = transaction; 2157c851ed54SJan Kara list_add(&jinode->i_list, &transaction->t_inode_list); 2158c851ed54SJan Kara done: 2159c851ed54SJan Kara spin_unlock(&journal->j_list_lock); 2160c851ed54SJan Kara 2161c851ed54SJan Kara return 0; 2162c851ed54SJan Kara } 2163c851ed54SJan Kara 2164c851ed54SJan Kara /* 21657f5aa215SJan Kara * File truncate and transaction commit interact with each other in a 21667f5aa215SJan Kara * non-trivial way. If a transaction writing data block A is 21677f5aa215SJan Kara * committing, we cannot discard the data by truncate until we have 21687f5aa215SJan Kara * written them. Otherwise if we crashed after the transaction with 21697f5aa215SJan Kara * write has committed but before the transaction with truncate has 21707f5aa215SJan Kara * committed, we could see stale data in block A. This function is a 21717f5aa215SJan Kara * helper to solve this problem. It starts writeout of the truncated 21727f5aa215SJan Kara * part in case it is in the committing transaction. 21737f5aa215SJan Kara * 21747f5aa215SJan Kara * Filesystem code must call this function when inode is journaled in 21757f5aa215SJan Kara * ordered mode before truncation happens and after the inode has been 21767f5aa215SJan Kara * placed on orphan list with the new inode size. The second condition 21777f5aa215SJan Kara * avoids the race that someone writes new data and we start 21787f5aa215SJan Kara * committing the transaction after this function has been called but 21797f5aa215SJan Kara * before a transaction for truncate is started (and furthermore it 21807f5aa215SJan Kara * allows us to optimize the case where the addition to orphan list 21817f5aa215SJan Kara * happens in the same transaction as write --- we don't have to write 21827f5aa215SJan Kara * any data in such case). 2183c851ed54SJan Kara */ 21847f5aa215SJan Kara int jbd2_journal_begin_ordered_truncate(journal_t *journal, 21857f5aa215SJan Kara struct jbd2_inode *jinode, 2186c851ed54SJan Kara loff_t new_size) 2187c851ed54SJan Kara { 21887f5aa215SJan Kara transaction_t *inode_trans, *commit_trans; 2189c851ed54SJan Kara int ret = 0; 2190c851ed54SJan Kara 21917f5aa215SJan Kara /* This is a quick check to avoid locking if not necessary */ 21927f5aa215SJan Kara if (!jinode->i_transaction) 2193c851ed54SJan Kara goto out; 21947f5aa215SJan Kara /* Locks are here just to force reading of recent values, it is 21957f5aa215SJan Kara * enough that the transaction was not committing before we started 21967f5aa215SJan Kara * a transaction adding the inode to orphan list */ 2197a931da6aSTheodore Ts'o read_lock(&journal->j_state_lock); 2198c851ed54SJan Kara commit_trans = journal->j_committing_transaction; 2199a931da6aSTheodore Ts'o read_unlock(&journal->j_state_lock); 22007f5aa215SJan Kara spin_lock(&journal->j_list_lock); 22017f5aa215SJan Kara inode_trans = jinode->i_transaction; 22027f5aa215SJan Kara spin_unlock(&journal->j_list_lock); 22037f5aa215SJan Kara if (inode_trans == commit_trans) { 22047f5aa215SJan Kara ret = filemap_fdatawrite_range(jinode->i_vfs_inode->i_mapping, 2205c851ed54SJan Kara new_size, LLONG_MAX); 2206c851ed54SJan Kara if (ret) 2207c851ed54SJan Kara jbd2_journal_abort(journal, ret); 2208c851ed54SJan Kara } 2209c851ed54SJan Kara out: 2210c851ed54SJan Kara return ret; 2211c851ed54SJan Kara } 2212