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> 28470decc6SDave Kleikamp 297ddae860SAdrian Bunk static void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh); 307ddae860SAdrian Bunk 31470decc6SDave Kleikamp /* 32f7f4bccbSMingming Cao * jbd2_get_transaction: obtain a new transaction_t object. 33470decc6SDave Kleikamp * 34470decc6SDave Kleikamp * Simply allocate and initialise a new transaction. Create it in 35470decc6SDave Kleikamp * RUNNING state and add it to the current journal (which should not 36470decc6SDave Kleikamp * have an existing running transaction: we only make a new transaction 37470decc6SDave Kleikamp * once we have started to commit the old one). 38470decc6SDave Kleikamp * 39470decc6SDave Kleikamp * Preconditions: 40470decc6SDave Kleikamp * The journal MUST be locked. We don't perform atomic mallocs on the 41470decc6SDave Kleikamp * new transaction and we can't block without protecting against other 42470decc6SDave Kleikamp * processes trying to touch the journal while it is in transition. 43470decc6SDave Kleikamp * 44470decc6SDave Kleikamp */ 45470decc6SDave Kleikamp 46470decc6SDave Kleikamp static transaction_t * 47f7f4bccbSMingming Cao jbd2_get_transaction(journal_t *journal, transaction_t *transaction) 48470decc6SDave Kleikamp { 49470decc6SDave Kleikamp transaction->t_journal = journal; 50470decc6SDave Kleikamp transaction->t_state = T_RUNNING; 51470decc6SDave Kleikamp transaction->t_tid = journal->j_transaction_sequence++; 52470decc6SDave Kleikamp transaction->t_expires = jiffies + journal->j_commit_interval; 53470decc6SDave Kleikamp spin_lock_init(&transaction->t_handle_lock); 54c851ed54SJan Kara INIT_LIST_HEAD(&transaction->t_inode_list); 553e624fc7STheodore Ts'o INIT_LIST_HEAD(&transaction->t_private_list); 56470decc6SDave Kleikamp 57470decc6SDave Kleikamp /* Set up the commit timer for the new transaction. */ 58db857da3SMingming Cao journal->j_commit_timer.expires = round_jiffies(transaction->t_expires); 59470decc6SDave Kleikamp add_timer(&journal->j_commit_timer); 60470decc6SDave Kleikamp 61470decc6SDave Kleikamp J_ASSERT(journal->j_running_transaction == NULL); 62470decc6SDave Kleikamp journal->j_running_transaction = transaction; 638e85fb3fSJohann Lombardi transaction->t_max_wait = 0; 648e85fb3fSJohann Lombardi transaction->t_start = jiffies; 65470decc6SDave Kleikamp 66470decc6SDave Kleikamp return transaction; 67470decc6SDave Kleikamp } 68470decc6SDave Kleikamp 69470decc6SDave Kleikamp /* 70470decc6SDave Kleikamp * Handle management. 71470decc6SDave Kleikamp * 72470decc6SDave Kleikamp * A handle_t is an object which represents a single atomic update to a 73470decc6SDave Kleikamp * filesystem, and which tracks all of the modifications which form part 74470decc6SDave Kleikamp * of that one update. 75470decc6SDave Kleikamp */ 76470decc6SDave Kleikamp 77470decc6SDave Kleikamp /* 78470decc6SDave Kleikamp * start_this_handle: Given a handle, deal with any locking or stalling 79470decc6SDave Kleikamp * needed to make sure that there is enough journal space for the handle 80470decc6SDave Kleikamp * to begin. Attach the handle to a transaction and set up the 81470decc6SDave Kleikamp * transaction's buffer credits. 82470decc6SDave Kleikamp */ 83470decc6SDave Kleikamp 84470decc6SDave Kleikamp static int start_this_handle(journal_t *journal, handle_t *handle) 85470decc6SDave Kleikamp { 86470decc6SDave Kleikamp transaction_t *transaction; 87470decc6SDave Kleikamp int needed; 88470decc6SDave Kleikamp int nblocks = handle->h_buffer_credits; 89470decc6SDave Kleikamp transaction_t *new_transaction = NULL; 90470decc6SDave Kleikamp int ret = 0; 918e85fb3fSJohann Lombardi unsigned long ts = jiffies; 92470decc6SDave Kleikamp 93470decc6SDave Kleikamp if (nblocks > journal->j_max_transaction_buffers) { 94470decc6SDave Kleikamp printk(KERN_ERR "JBD: %s wants too many credits (%d > %d)\n", 95470decc6SDave Kleikamp current->comm, nblocks, 96470decc6SDave Kleikamp journal->j_max_transaction_buffers); 97470decc6SDave Kleikamp ret = -ENOSPC; 98470decc6SDave Kleikamp goto out; 99470decc6SDave Kleikamp } 100470decc6SDave Kleikamp 101470decc6SDave Kleikamp alloc_transaction: 102470decc6SDave Kleikamp if (!journal->j_running_transaction) { 103d802ffa8SMingming Cao new_transaction = kzalloc(sizeof(*new_transaction), 1042d917969SMingming Cao GFP_NOFS|__GFP_NOFAIL); 105470decc6SDave Kleikamp if (!new_transaction) { 106470decc6SDave Kleikamp ret = -ENOMEM; 107470decc6SDave Kleikamp goto out; 108470decc6SDave Kleikamp } 109470decc6SDave Kleikamp } 110470decc6SDave Kleikamp 111470decc6SDave Kleikamp jbd_debug(3, "New handle %p going live.\n", handle); 112470decc6SDave Kleikamp 113470decc6SDave Kleikamp repeat: 114470decc6SDave Kleikamp 115470decc6SDave Kleikamp /* 116470decc6SDave Kleikamp * We need to hold j_state_lock until t_updates has been incremented, 117470decc6SDave Kleikamp * for proper journal barrier handling 118470decc6SDave Kleikamp */ 119470decc6SDave Kleikamp spin_lock(&journal->j_state_lock); 120470decc6SDave Kleikamp repeat_locked: 121470decc6SDave Kleikamp if (is_journal_aborted(journal) || 122f7f4bccbSMingming Cao (journal->j_errno != 0 && !(journal->j_flags & JBD2_ACK_ERR))) { 123470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 124470decc6SDave Kleikamp ret = -EROFS; 125470decc6SDave Kleikamp goto out; 126470decc6SDave Kleikamp } 127470decc6SDave Kleikamp 128470decc6SDave Kleikamp /* Wait on the journal's transaction barrier if necessary */ 129470decc6SDave Kleikamp if (journal->j_barrier_count) { 130470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 131470decc6SDave Kleikamp wait_event(journal->j_wait_transaction_locked, 132470decc6SDave Kleikamp journal->j_barrier_count == 0); 133470decc6SDave Kleikamp goto repeat; 134470decc6SDave Kleikamp } 135470decc6SDave Kleikamp 136470decc6SDave Kleikamp if (!journal->j_running_transaction) { 137470decc6SDave Kleikamp if (!new_transaction) { 138470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 139470decc6SDave Kleikamp goto alloc_transaction; 140470decc6SDave Kleikamp } 141f7f4bccbSMingming Cao jbd2_get_transaction(journal, new_transaction); 142470decc6SDave Kleikamp new_transaction = NULL; 143470decc6SDave Kleikamp } 144470decc6SDave Kleikamp 145470decc6SDave Kleikamp transaction = journal->j_running_transaction; 146470decc6SDave Kleikamp 147470decc6SDave Kleikamp /* 148470decc6SDave Kleikamp * If the current transaction is locked down for commit, wait for the 149470decc6SDave Kleikamp * lock to be released. 150470decc6SDave Kleikamp */ 151470decc6SDave Kleikamp if (transaction->t_state == T_LOCKED) { 152470decc6SDave Kleikamp DEFINE_WAIT(wait); 153470decc6SDave Kleikamp 154470decc6SDave Kleikamp prepare_to_wait(&journal->j_wait_transaction_locked, 155470decc6SDave Kleikamp &wait, TASK_UNINTERRUPTIBLE); 156470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 157470decc6SDave Kleikamp schedule(); 158470decc6SDave Kleikamp finish_wait(&journal->j_wait_transaction_locked, &wait); 159470decc6SDave Kleikamp goto repeat; 160470decc6SDave Kleikamp } 161470decc6SDave Kleikamp 162470decc6SDave Kleikamp /* 163470decc6SDave Kleikamp * If there is not enough space left in the log to write all potential 164470decc6SDave Kleikamp * buffers requested by this operation, we need to stall pending a log 165470decc6SDave Kleikamp * checkpoint to free some more log space. 166470decc6SDave Kleikamp */ 167470decc6SDave Kleikamp spin_lock(&transaction->t_handle_lock); 168470decc6SDave Kleikamp needed = transaction->t_outstanding_credits + nblocks; 169470decc6SDave Kleikamp 170470decc6SDave Kleikamp if (needed > journal->j_max_transaction_buffers) { 171470decc6SDave Kleikamp /* 172470decc6SDave Kleikamp * If the current transaction is already too large, then start 173470decc6SDave Kleikamp * to commit it: we can then go back and attach this handle to 174470decc6SDave Kleikamp * a new transaction. 175470decc6SDave Kleikamp */ 176470decc6SDave Kleikamp DEFINE_WAIT(wait); 177470decc6SDave Kleikamp 178470decc6SDave Kleikamp jbd_debug(2, "Handle %p starting new commit...\n", handle); 179470decc6SDave Kleikamp spin_unlock(&transaction->t_handle_lock); 180470decc6SDave Kleikamp prepare_to_wait(&journal->j_wait_transaction_locked, &wait, 181470decc6SDave Kleikamp TASK_UNINTERRUPTIBLE); 182f7f4bccbSMingming Cao __jbd2_log_start_commit(journal, transaction->t_tid); 183470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 184470decc6SDave Kleikamp schedule(); 185470decc6SDave Kleikamp finish_wait(&journal->j_wait_transaction_locked, &wait); 186470decc6SDave Kleikamp goto repeat; 187470decc6SDave Kleikamp } 188470decc6SDave Kleikamp 189470decc6SDave Kleikamp /* 190470decc6SDave Kleikamp * The commit code assumes that it can get enough log space 191470decc6SDave Kleikamp * without forcing a checkpoint. This is *critical* for 192470decc6SDave Kleikamp * correctness: a checkpoint of a buffer which is also 193470decc6SDave Kleikamp * associated with a committing transaction creates a deadlock, 194470decc6SDave Kleikamp * so commit simply cannot force through checkpoints. 195470decc6SDave Kleikamp * 196470decc6SDave Kleikamp * We must therefore ensure the necessary space in the journal 197470decc6SDave Kleikamp * *before* starting to dirty potentially checkpointed buffers 198470decc6SDave Kleikamp * in the new transaction. 199470decc6SDave Kleikamp * 200470decc6SDave Kleikamp * The worst part is, any transaction currently committing can 201470decc6SDave Kleikamp * reduce the free space arbitrarily. Be careful to account for 202470decc6SDave Kleikamp * those buffers when checkpointing. 203470decc6SDave Kleikamp */ 204470decc6SDave Kleikamp 205470decc6SDave Kleikamp /* 206470decc6SDave Kleikamp * @@@ AKPM: This seems rather over-defensive. We're giving commit 207470decc6SDave Kleikamp * a _lot_ of headroom: 1/4 of the journal plus the size of 208470decc6SDave Kleikamp * the committing transaction. Really, we only need to give it 209470decc6SDave Kleikamp * committing_transaction->t_outstanding_credits plus "enough" for 210470decc6SDave Kleikamp * the log control blocks. 211470decc6SDave Kleikamp * Also, this test is inconsitent with the matching one in 212f7f4bccbSMingming Cao * jbd2_journal_extend(). 213470decc6SDave Kleikamp */ 214f7f4bccbSMingming Cao if (__jbd2_log_space_left(journal) < jbd_space_needed(journal)) { 215470decc6SDave Kleikamp jbd_debug(2, "Handle %p waiting for checkpoint...\n", handle); 216470decc6SDave Kleikamp spin_unlock(&transaction->t_handle_lock); 217f7f4bccbSMingming Cao __jbd2_log_wait_for_space(journal); 218470decc6SDave Kleikamp goto repeat_locked; 219470decc6SDave Kleikamp } 220470decc6SDave Kleikamp 221470decc6SDave Kleikamp /* OK, account for the buffers that this operation expects to 222470decc6SDave Kleikamp * use and add the handle to the running transaction. */ 223470decc6SDave Kleikamp 2248e85fb3fSJohann Lombardi if (time_after(transaction->t_start, ts)) { 2258e85fb3fSJohann Lombardi ts = jbd2_time_diff(ts, transaction->t_start); 2268e85fb3fSJohann Lombardi if (ts > transaction->t_max_wait) 2278e85fb3fSJohann Lombardi transaction->t_max_wait = ts; 2288e85fb3fSJohann Lombardi } 2298e85fb3fSJohann Lombardi 230470decc6SDave Kleikamp handle->h_transaction = transaction; 231470decc6SDave Kleikamp transaction->t_outstanding_credits += nblocks; 232470decc6SDave Kleikamp transaction->t_updates++; 233470decc6SDave Kleikamp transaction->t_handle_count++; 234470decc6SDave Kleikamp jbd_debug(4, "Handle %p given %d credits (total %d, free %d)\n", 235470decc6SDave Kleikamp handle, nblocks, transaction->t_outstanding_credits, 236f7f4bccbSMingming Cao __jbd2_log_space_left(journal)); 237470decc6SDave Kleikamp spin_unlock(&transaction->t_handle_lock); 238470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 239470decc6SDave Kleikamp out: 240470decc6SDave Kleikamp if (unlikely(new_transaction)) /* It's usually NULL */ 241470decc6SDave Kleikamp kfree(new_transaction); 242470decc6SDave Kleikamp return ret; 243470decc6SDave Kleikamp } 244470decc6SDave Kleikamp 2457b751066SMingming Cao static struct lock_class_key jbd2_handle_key; 2467b751066SMingming Cao 247470decc6SDave Kleikamp /* Allocate a new handle. This should probably be in a slab... */ 248470decc6SDave Kleikamp static handle_t *new_handle(int nblocks) 249470decc6SDave Kleikamp { 250af1e76d6SMingming Cao handle_t *handle = jbd2_alloc_handle(GFP_NOFS); 251470decc6SDave Kleikamp if (!handle) 252470decc6SDave Kleikamp return NULL; 253470decc6SDave Kleikamp memset(handle, 0, sizeof(*handle)); 254470decc6SDave Kleikamp handle->h_buffer_credits = nblocks; 255470decc6SDave Kleikamp handle->h_ref = 1; 256470decc6SDave Kleikamp 2577b751066SMingming Cao lockdep_init_map(&handle->h_lockdep_map, "jbd2_handle", 2587b751066SMingming Cao &jbd2_handle_key, 0); 2597b751066SMingming Cao 260470decc6SDave Kleikamp return handle; 261470decc6SDave Kleikamp } 262470decc6SDave Kleikamp 263470decc6SDave Kleikamp /** 264f7f4bccbSMingming Cao * handle_t *jbd2_journal_start() - Obtain a new handle. 265470decc6SDave Kleikamp * @journal: Journal to start transaction on. 266470decc6SDave Kleikamp * @nblocks: number of block buffer we might modify 267470decc6SDave Kleikamp * 268470decc6SDave Kleikamp * We make sure that the transaction can guarantee at least nblocks of 269470decc6SDave Kleikamp * modified buffers in the log. We block until the log can guarantee 270470decc6SDave Kleikamp * that much space. 271470decc6SDave Kleikamp * 272470decc6SDave Kleikamp * This function is visible to journal users (like ext3fs), so is not 273470decc6SDave Kleikamp * called with the journal already locked. 274470decc6SDave Kleikamp * 275470decc6SDave Kleikamp * Return a pointer to a newly allocated handle, or NULL on failure 276470decc6SDave Kleikamp */ 277f7f4bccbSMingming Cao handle_t *jbd2_journal_start(journal_t *journal, int nblocks) 278470decc6SDave Kleikamp { 279470decc6SDave Kleikamp handle_t *handle = journal_current_handle(); 280470decc6SDave Kleikamp int err; 281470decc6SDave Kleikamp 282470decc6SDave Kleikamp if (!journal) 283470decc6SDave Kleikamp return ERR_PTR(-EROFS); 284470decc6SDave Kleikamp 285470decc6SDave Kleikamp if (handle) { 286470decc6SDave Kleikamp J_ASSERT(handle->h_transaction->t_journal == journal); 287470decc6SDave Kleikamp handle->h_ref++; 288470decc6SDave Kleikamp return handle; 289470decc6SDave Kleikamp } 290470decc6SDave Kleikamp 291470decc6SDave Kleikamp handle = new_handle(nblocks); 292470decc6SDave Kleikamp if (!handle) 293470decc6SDave Kleikamp return ERR_PTR(-ENOMEM); 294470decc6SDave Kleikamp 295470decc6SDave Kleikamp current->journal_info = handle; 296470decc6SDave Kleikamp 297470decc6SDave Kleikamp err = start_this_handle(journal, handle); 298470decc6SDave Kleikamp if (err < 0) { 299af1e76d6SMingming Cao jbd2_free_handle(handle); 300470decc6SDave Kleikamp current->journal_info = NULL; 301470decc6SDave Kleikamp handle = ERR_PTR(err); 3027b751066SMingming Cao goto out; 303470decc6SDave Kleikamp } 3047b751066SMingming Cao 3053295f0efSIngo Molnar lock_map_acquire(&handle->h_lockdep_map); 3067b751066SMingming Cao out: 307470decc6SDave Kleikamp return handle; 308470decc6SDave Kleikamp } 309470decc6SDave Kleikamp 310470decc6SDave Kleikamp /** 311f7f4bccbSMingming Cao * int jbd2_journal_extend() - extend buffer credits. 312470decc6SDave Kleikamp * @handle: handle to 'extend' 313470decc6SDave Kleikamp * @nblocks: nr blocks to try to extend by. 314470decc6SDave Kleikamp * 315470decc6SDave Kleikamp * Some transactions, such as large extends and truncates, can be done 316470decc6SDave Kleikamp * atomically all at once or in several stages. The operation requests 317470decc6SDave Kleikamp * a credit for a number of buffer modications in advance, but can 318470decc6SDave Kleikamp * extend its credit if it needs more. 319470decc6SDave Kleikamp * 320f7f4bccbSMingming Cao * jbd2_journal_extend tries to give the running handle more buffer credits. 321470decc6SDave Kleikamp * It does not guarantee that allocation - this is a best-effort only. 322470decc6SDave Kleikamp * The calling process MUST be able to deal cleanly with a failure to 323470decc6SDave Kleikamp * extend here. 324470decc6SDave Kleikamp * 325470decc6SDave Kleikamp * Return 0 on success, non-zero on failure. 326470decc6SDave Kleikamp * 327470decc6SDave Kleikamp * return code < 0 implies an error 328470decc6SDave Kleikamp * return code > 0 implies normal transaction-full status. 329470decc6SDave Kleikamp */ 330f7f4bccbSMingming Cao int jbd2_journal_extend(handle_t *handle, int nblocks) 331470decc6SDave Kleikamp { 332470decc6SDave Kleikamp transaction_t *transaction = handle->h_transaction; 333470decc6SDave Kleikamp journal_t *journal = transaction->t_journal; 334470decc6SDave Kleikamp int result; 335470decc6SDave Kleikamp int wanted; 336470decc6SDave Kleikamp 337470decc6SDave Kleikamp result = -EIO; 338470decc6SDave Kleikamp if (is_handle_aborted(handle)) 339470decc6SDave Kleikamp goto out; 340470decc6SDave Kleikamp 341470decc6SDave Kleikamp result = 1; 342470decc6SDave Kleikamp 343470decc6SDave Kleikamp spin_lock(&journal->j_state_lock); 344470decc6SDave Kleikamp 345470decc6SDave Kleikamp /* Don't extend a locked-down transaction! */ 346470decc6SDave Kleikamp if (handle->h_transaction->t_state != T_RUNNING) { 347470decc6SDave Kleikamp jbd_debug(3, "denied handle %p %d blocks: " 348470decc6SDave Kleikamp "transaction not running\n", handle, nblocks); 349470decc6SDave Kleikamp goto error_out; 350470decc6SDave Kleikamp } 351470decc6SDave Kleikamp 352470decc6SDave Kleikamp spin_lock(&transaction->t_handle_lock); 353470decc6SDave Kleikamp wanted = transaction->t_outstanding_credits + nblocks; 354470decc6SDave Kleikamp 355470decc6SDave Kleikamp if (wanted > journal->j_max_transaction_buffers) { 356470decc6SDave Kleikamp jbd_debug(3, "denied handle %p %d blocks: " 357470decc6SDave Kleikamp "transaction too large\n", handle, nblocks); 358470decc6SDave Kleikamp goto unlock; 359470decc6SDave Kleikamp } 360470decc6SDave Kleikamp 361f7f4bccbSMingming Cao if (wanted > __jbd2_log_space_left(journal)) { 362470decc6SDave Kleikamp jbd_debug(3, "denied handle %p %d blocks: " 363470decc6SDave Kleikamp "insufficient log space\n", handle, nblocks); 364470decc6SDave Kleikamp goto unlock; 365470decc6SDave Kleikamp } 366470decc6SDave Kleikamp 367470decc6SDave Kleikamp handle->h_buffer_credits += nblocks; 368470decc6SDave Kleikamp transaction->t_outstanding_credits += nblocks; 369470decc6SDave Kleikamp result = 0; 370470decc6SDave Kleikamp 371470decc6SDave Kleikamp jbd_debug(3, "extended handle %p by %d\n", handle, nblocks); 372470decc6SDave Kleikamp unlock: 373470decc6SDave Kleikamp spin_unlock(&transaction->t_handle_lock); 374470decc6SDave Kleikamp error_out: 375470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 376470decc6SDave Kleikamp out: 377470decc6SDave Kleikamp return result; 378470decc6SDave Kleikamp } 379470decc6SDave Kleikamp 380470decc6SDave Kleikamp 381470decc6SDave Kleikamp /** 382f7f4bccbSMingming Cao * int jbd2_journal_restart() - restart a handle . 383470decc6SDave Kleikamp * @handle: handle to restart 384470decc6SDave Kleikamp * @nblocks: nr credits requested 385470decc6SDave Kleikamp * 386470decc6SDave Kleikamp * Restart a handle for a multi-transaction filesystem 387470decc6SDave Kleikamp * operation. 388470decc6SDave Kleikamp * 389f7f4bccbSMingming Cao * If the jbd2_journal_extend() call above fails to grant new buffer credits 390f7f4bccbSMingming Cao * to a running handle, a call to jbd2_journal_restart will commit the 391470decc6SDave Kleikamp * handle's transaction so far and reattach the handle to a new 392470decc6SDave Kleikamp * transaction capabable of guaranteeing the requested number of 393470decc6SDave Kleikamp * credits. 394470decc6SDave Kleikamp */ 395470decc6SDave Kleikamp 396f7f4bccbSMingming Cao int jbd2_journal_restart(handle_t *handle, int nblocks) 397470decc6SDave Kleikamp { 398470decc6SDave Kleikamp transaction_t *transaction = handle->h_transaction; 399470decc6SDave Kleikamp journal_t *journal = transaction->t_journal; 400470decc6SDave Kleikamp int ret; 401470decc6SDave Kleikamp 402470decc6SDave Kleikamp /* If we've had an abort of any type, don't even think about 403470decc6SDave Kleikamp * actually doing the restart! */ 404470decc6SDave Kleikamp if (is_handle_aborted(handle)) 405470decc6SDave Kleikamp return 0; 406470decc6SDave Kleikamp 407470decc6SDave Kleikamp /* 408470decc6SDave Kleikamp * First unlink the handle from its current transaction, and start the 409470decc6SDave Kleikamp * commit on that. 410470decc6SDave Kleikamp */ 411470decc6SDave Kleikamp J_ASSERT(transaction->t_updates > 0); 412470decc6SDave Kleikamp J_ASSERT(journal_current_handle() == handle); 413470decc6SDave Kleikamp 414470decc6SDave Kleikamp spin_lock(&journal->j_state_lock); 415470decc6SDave Kleikamp spin_lock(&transaction->t_handle_lock); 416470decc6SDave Kleikamp transaction->t_outstanding_credits -= handle->h_buffer_credits; 417470decc6SDave Kleikamp transaction->t_updates--; 418470decc6SDave Kleikamp 419470decc6SDave Kleikamp if (!transaction->t_updates) 420470decc6SDave Kleikamp wake_up(&journal->j_wait_updates); 421470decc6SDave Kleikamp spin_unlock(&transaction->t_handle_lock); 422470decc6SDave Kleikamp 423470decc6SDave Kleikamp jbd_debug(2, "restarting handle %p\n", handle); 424f7f4bccbSMingming Cao __jbd2_log_start_commit(journal, transaction->t_tid); 425470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 426470decc6SDave Kleikamp 427470decc6SDave Kleikamp handle->h_buffer_credits = nblocks; 428470decc6SDave Kleikamp ret = start_this_handle(journal, handle); 429470decc6SDave Kleikamp return ret; 430470decc6SDave Kleikamp } 431470decc6SDave Kleikamp 432470decc6SDave Kleikamp 433470decc6SDave Kleikamp /** 434f7f4bccbSMingming Cao * void jbd2_journal_lock_updates () - establish a transaction barrier. 435470decc6SDave Kleikamp * @journal: Journal to establish a barrier on. 436470decc6SDave Kleikamp * 437470decc6SDave Kleikamp * This locks out any further updates from being started, and blocks 438470decc6SDave Kleikamp * until all existing updates have completed, returning only once the 439470decc6SDave Kleikamp * journal is in a quiescent state with no updates running. 440470decc6SDave Kleikamp * 441470decc6SDave Kleikamp * The journal lock should not be held on entry. 442470decc6SDave Kleikamp */ 443f7f4bccbSMingming Cao void jbd2_journal_lock_updates(journal_t *journal) 444470decc6SDave Kleikamp { 445470decc6SDave Kleikamp DEFINE_WAIT(wait); 446470decc6SDave Kleikamp 447470decc6SDave Kleikamp spin_lock(&journal->j_state_lock); 448470decc6SDave Kleikamp ++journal->j_barrier_count; 449470decc6SDave Kleikamp 450470decc6SDave Kleikamp /* Wait until there are no running updates */ 451470decc6SDave Kleikamp while (1) { 452470decc6SDave Kleikamp transaction_t *transaction = journal->j_running_transaction; 453470decc6SDave Kleikamp 454470decc6SDave Kleikamp if (!transaction) 455470decc6SDave Kleikamp break; 456470decc6SDave Kleikamp 457470decc6SDave Kleikamp spin_lock(&transaction->t_handle_lock); 458470decc6SDave Kleikamp if (!transaction->t_updates) { 459470decc6SDave Kleikamp spin_unlock(&transaction->t_handle_lock); 460470decc6SDave Kleikamp break; 461470decc6SDave Kleikamp } 462470decc6SDave Kleikamp prepare_to_wait(&journal->j_wait_updates, &wait, 463470decc6SDave Kleikamp TASK_UNINTERRUPTIBLE); 464470decc6SDave Kleikamp spin_unlock(&transaction->t_handle_lock); 465470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 466470decc6SDave Kleikamp schedule(); 467470decc6SDave Kleikamp finish_wait(&journal->j_wait_updates, &wait); 468470decc6SDave Kleikamp spin_lock(&journal->j_state_lock); 469470decc6SDave Kleikamp } 470470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 471470decc6SDave Kleikamp 472470decc6SDave Kleikamp /* 473470decc6SDave Kleikamp * We have now established a barrier against other normal updates, but 474f7f4bccbSMingming Cao * we also need to barrier against other jbd2_journal_lock_updates() calls 475470decc6SDave Kleikamp * to make sure that we serialise special journal-locked operations 476470decc6SDave Kleikamp * too. 477470decc6SDave Kleikamp */ 478470decc6SDave Kleikamp mutex_lock(&journal->j_barrier); 479470decc6SDave Kleikamp } 480470decc6SDave Kleikamp 481470decc6SDave Kleikamp /** 482f7f4bccbSMingming Cao * void jbd2_journal_unlock_updates (journal_t* journal) - release barrier 483470decc6SDave Kleikamp * @journal: Journal to release the barrier on. 484470decc6SDave Kleikamp * 485f7f4bccbSMingming Cao * Release a transaction barrier obtained with jbd2_journal_lock_updates(). 486470decc6SDave Kleikamp * 487470decc6SDave Kleikamp * Should be called without the journal lock held. 488470decc6SDave Kleikamp */ 489f7f4bccbSMingming Cao void jbd2_journal_unlock_updates (journal_t *journal) 490470decc6SDave Kleikamp { 491470decc6SDave Kleikamp J_ASSERT(journal->j_barrier_count != 0); 492470decc6SDave Kleikamp 493470decc6SDave Kleikamp mutex_unlock(&journal->j_barrier); 494470decc6SDave Kleikamp spin_lock(&journal->j_state_lock); 495470decc6SDave Kleikamp --journal->j_barrier_count; 496470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 497470decc6SDave Kleikamp wake_up(&journal->j_wait_transaction_locked); 498470decc6SDave Kleikamp } 499470decc6SDave Kleikamp 500470decc6SDave Kleikamp /* 501470decc6SDave Kleikamp * Report any unexpected dirty buffers which turn up. Normally those 502470decc6SDave Kleikamp * indicate an error, but they can occur if the user is running (say) 503470decc6SDave Kleikamp * tune2fs to modify the live filesystem, so we need the option of 504470decc6SDave Kleikamp * continuing as gracefully as possible. # 505470decc6SDave Kleikamp * 506470decc6SDave Kleikamp * The caller should already hold the journal lock and 507470decc6SDave Kleikamp * j_list_lock spinlock: most callers will need those anyway 508470decc6SDave Kleikamp * in order to probe the buffer's journaling state safely. 509470decc6SDave Kleikamp */ 510470decc6SDave Kleikamp static void jbd_unexpected_dirty_buffer(struct journal_head *jh) 511470decc6SDave Kleikamp { 512470decc6SDave Kleikamp int jlist; 513470decc6SDave Kleikamp 514470decc6SDave Kleikamp /* If this buffer is one which might reasonably be dirty 515470decc6SDave Kleikamp * --- ie. data, or not part of this journal --- then 516470decc6SDave Kleikamp * we're OK to leave it alone, but otherwise we need to 517470decc6SDave Kleikamp * move the dirty bit to the journal's own internal 518470decc6SDave Kleikamp * JBDDirty bit. */ 519470decc6SDave Kleikamp jlist = jh->b_jlist; 520470decc6SDave Kleikamp 521470decc6SDave Kleikamp if (jlist == BJ_Metadata || jlist == BJ_Reserved || 522470decc6SDave Kleikamp jlist == BJ_Shadow || jlist == BJ_Forget) { 523470decc6SDave Kleikamp struct buffer_head *bh = jh2bh(jh); 524470decc6SDave Kleikamp 525470decc6SDave Kleikamp if (test_clear_buffer_dirty(bh)) 526470decc6SDave Kleikamp set_buffer_jbddirty(bh); 527470decc6SDave Kleikamp } 528470decc6SDave Kleikamp } 529470decc6SDave Kleikamp 530470decc6SDave Kleikamp /* 531470decc6SDave Kleikamp * If the buffer is already part of the current transaction, then there 532470decc6SDave Kleikamp * is nothing we need to do. If it is already part of a prior 533470decc6SDave Kleikamp * transaction which we are still committing to disk, then we need to 534470decc6SDave Kleikamp * make sure that we do not overwrite the old copy: we do copy-out to 535470decc6SDave Kleikamp * preserve the copy going to disk. We also account the buffer against 536470decc6SDave Kleikamp * the handle's metadata buffer credits (unless the buffer is already 537470decc6SDave Kleikamp * part of the transaction, that is). 538470decc6SDave Kleikamp * 539470decc6SDave Kleikamp */ 540470decc6SDave Kleikamp static int 541470decc6SDave Kleikamp do_get_write_access(handle_t *handle, struct journal_head *jh, 542470decc6SDave Kleikamp int force_copy) 543470decc6SDave Kleikamp { 544470decc6SDave Kleikamp struct buffer_head *bh; 545470decc6SDave Kleikamp transaction_t *transaction; 546470decc6SDave Kleikamp journal_t *journal; 547470decc6SDave Kleikamp int error; 548470decc6SDave Kleikamp char *frozen_buffer = NULL; 549470decc6SDave Kleikamp int need_copy = 0; 550470decc6SDave Kleikamp 551470decc6SDave Kleikamp if (is_handle_aborted(handle)) 552470decc6SDave Kleikamp return -EROFS; 553470decc6SDave Kleikamp 554470decc6SDave Kleikamp transaction = handle->h_transaction; 555470decc6SDave Kleikamp journal = transaction->t_journal; 556470decc6SDave Kleikamp 557470decc6SDave Kleikamp jbd_debug(5, "buffer_head %p, force_copy %d\n", jh, force_copy); 558470decc6SDave Kleikamp 559470decc6SDave Kleikamp JBUFFER_TRACE(jh, "entry"); 560470decc6SDave Kleikamp repeat: 561470decc6SDave Kleikamp bh = jh2bh(jh); 562470decc6SDave Kleikamp 563470decc6SDave Kleikamp /* @@@ Need to check for errors here at some point. */ 564470decc6SDave Kleikamp 565470decc6SDave Kleikamp lock_buffer(bh); 566470decc6SDave Kleikamp jbd_lock_bh_state(bh); 567470decc6SDave Kleikamp 568470decc6SDave Kleikamp /* We now hold the buffer lock so it is safe to query the buffer 569470decc6SDave Kleikamp * state. Is the buffer dirty? 570470decc6SDave Kleikamp * 571470decc6SDave Kleikamp * If so, there are two possibilities. The buffer may be 572470decc6SDave Kleikamp * non-journaled, and undergoing a quite legitimate writeback. 573470decc6SDave Kleikamp * Otherwise, it is journaled, and we don't expect dirty buffers 574470decc6SDave Kleikamp * in that state (the buffers should be marked JBD_Dirty 575470decc6SDave Kleikamp * instead.) So either the IO is being done under our own 576470decc6SDave Kleikamp * control and this is a bug, or it's a third party IO such as 577470decc6SDave Kleikamp * dump(8) (which may leave the buffer scheduled for read --- 578470decc6SDave Kleikamp * ie. locked but not dirty) or tune2fs (which may actually have 579470decc6SDave Kleikamp * the buffer dirtied, ugh.) */ 580470decc6SDave Kleikamp 581470decc6SDave Kleikamp if (buffer_dirty(bh)) { 582470decc6SDave Kleikamp /* 583470decc6SDave Kleikamp * First question: is this buffer already part of the current 584470decc6SDave Kleikamp * transaction or the existing committing transaction? 585470decc6SDave Kleikamp */ 586470decc6SDave Kleikamp if (jh->b_transaction) { 587470decc6SDave Kleikamp J_ASSERT_JH(jh, 588470decc6SDave Kleikamp jh->b_transaction == transaction || 589470decc6SDave Kleikamp jh->b_transaction == 590470decc6SDave Kleikamp journal->j_committing_transaction); 591470decc6SDave Kleikamp if (jh->b_next_transaction) 592470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_next_transaction == 593470decc6SDave Kleikamp transaction); 594470decc6SDave Kleikamp } 595470decc6SDave Kleikamp /* 596470decc6SDave Kleikamp * In any case we need to clean the dirty flag and we must 597470decc6SDave Kleikamp * do it under the buffer lock to be sure we don't race 598470decc6SDave Kleikamp * with running write-out. 599470decc6SDave Kleikamp */ 600470decc6SDave Kleikamp JBUFFER_TRACE(jh, "Unexpected dirty buffer"); 601470decc6SDave Kleikamp jbd_unexpected_dirty_buffer(jh); 602470decc6SDave Kleikamp } 603470decc6SDave Kleikamp 604470decc6SDave Kleikamp unlock_buffer(bh); 605470decc6SDave Kleikamp 606470decc6SDave Kleikamp error = -EROFS; 607470decc6SDave Kleikamp if (is_handle_aborted(handle)) { 608470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 609470decc6SDave Kleikamp goto out; 610470decc6SDave Kleikamp } 611470decc6SDave Kleikamp error = 0; 612470decc6SDave Kleikamp 613470decc6SDave Kleikamp /* 614470decc6SDave Kleikamp * The buffer is already part of this transaction if b_transaction or 615470decc6SDave Kleikamp * b_next_transaction points to it 616470decc6SDave Kleikamp */ 617470decc6SDave Kleikamp if (jh->b_transaction == transaction || 618470decc6SDave Kleikamp jh->b_next_transaction == transaction) 619470decc6SDave Kleikamp goto done; 620470decc6SDave Kleikamp 621470decc6SDave Kleikamp /* 6229fc7c63aSJosef Bacik * this is the first time this transaction is touching this buffer, 6239fc7c63aSJosef Bacik * reset the modified flag 6249fc7c63aSJosef Bacik */ 6259fc7c63aSJosef Bacik jh->b_modified = 0; 6269fc7c63aSJosef Bacik 6279fc7c63aSJosef Bacik /* 628470decc6SDave Kleikamp * If there is already a copy-out version of this buffer, then we don't 629470decc6SDave Kleikamp * need to make another one 630470decc6SDave Kleikamp */ 631470decc6SDave Kleikamp if (jh->b_frozen_data) { 632470decc6SDave Kleikamp JBUFFER_TRACE(jh, "has frozen data"); 633470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_next_transaction == NULL); 634470decc6SDave Kleikamp jh->b_next_transaction = transaction; 635470decc6SDave Kleikamp goto done; 636470decc6SDave Kleikamp } 637470decc6SDave Kleikamp 638470decc6SDave Kleikamp /* Is there data here we need to preserve? */ 639470decc6SDave Kleikamp 640470decc6SDave Kleikamp if (jh->b_transaction && jh->b_transaction != transaction) { 641470decc6SDave Kleikamp JBUFFER_TRACE(jh, "owned by older transaction"); 642470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_next_transaction == NULL); 643470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_transaction == 644470decc6SDave Kleikamp journal->j_committing_transaction); 645470decc6SDave Kleikamp 646470decc6SDave Kleikamp /* There is one case we have to be very careful about. 647470decc6SDave Kleikamp * If the committing transaction is currently writing 648470decc6SDave Kleikamp * this buffer out to disk and has NOT made a copy-out, 649470decc6SDave Kleikamp * then we cannot modify the buffer contents at all 650470decc6SDave Kleikamp * right now. The essence of copy-out is that it is the 651470decc6SDave Kleikamp * extra copy, not the primary copy, which gets 652470decc6SDave Kleikamp * journaled. If the primary copy is already going to 653470decc6SDave Kleikamp * disk then we cannot do copy-out here. */ 654470decc6SDave Kleikamp 655470decc6SDave Kleikamp if (jh->b_jlist == BJ_Shadow) { 656470decc6SDave Kleikamp DEFINE_WAIT_BIT(wait, &bh->b_state, BH_Unshadow); 657470decc6SDave Kleikamp wait_queue_head_t *wqh; 658470decc6SDave Kleikamp 659470decc6SDave Kleikamp wqh = bit_waitqueue(&bh->b_state, BH_Unshadow); 660470decc6SDave Kleikamp 661470decc6SDave Kleikamp JBUFFER_TRACE(jh, "on shadow: sleep"); 662470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 663470decc6SDave Kleikamp /* commit wakes up all shadow buffers after IO */ 664470decc6SDave Kleikamp for ( ; ; ) { 665470decc6SDave Kleikamp prepare_to_wait(wqh, &wait.wait, 666470decc6SDave Kleikamp TASK_UNINTERRUPTIBLE); 667470decc6SDave Kleikamp if (jh->b_jlist != BJ_Shadow) 668470decc6SDave Kleikamp break; 669470decc6SDave Kleikamp schedule(); 670470decc6SDave Kleikamp } 671470decc6SDave Kleikamp finish_wait(wqh, &wait.wait); 672470decc6SDave Kleikamp goto repeat; 673470decc6SDave Kleikamp } 674470decc6SDave Kleikamp 675470decc6SDave Kleikamp /* Only do the copy if the currently-owning transaction 676470decc6SDave Kleikamp * still needs it. If it is on the Forget list, the 677470decc6SDave Kleikamp * committing transaction is past that stage. The 678470decc6SDave Kleikamp * buffer had better remain locked during the kmalloc, 679470decc6SDave Kleikamp * but that should be true --- we hold the journal lock 680470decc6SDave Kleikamp * still and the buffer is already on the BUF_JOURNAL 681470decc6SDave Kleikamp * list so won't be flushed. 682470decc6SDave Kleikamp * 683470decc6SDave Kleikamp * Subtle point, though: if this is a get_undo_access, 684470decc6SDave Kleikamp * then we will be relying on the frozen_data to contain 685470decc6SDave Kleikamp * the new value of the committed_data record after the 686470decc6SDave Kleikamp * transaction, so we HAVE to force the frozen_data copy 687470decc6SDave Kleikamp * in that case. */ 688470decc6SDave Kleikamp 689470decc6SDave Kleikamp if (jh->b_jlist != BJ_Forget || force_copy) { 690470decc6SDave Kleikamp JBUFFER_TRACE(jh, "generate frozen data"); 691470decc6SDave Kleikamp if (!frozen_buffer) { 692470decc6SDave Kleikamp JBUFFER_TRACE(jh, "allocate memory for buffer"); 693470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 694470decc6SDave Kleikamp frozen_buffer = 695af1e76d6SMingming Cao jbd2_alloc(jh2bh(jh)->b_size, 696470decc6SDave Kleikamp GFP_NOFS); 697470decc6SDave Kleikamp if (!frozen_buffer) { 698470decc6SDave Kleikamp printk(KERN_EMERG 699470decc6SDave Kleikamp "%s: OOM for frozen_buffer\n", 700329d291fSHarvey Harrison __func__); 701470decc6SDave Kleikamp JBUFFER_TRACE(jh, "oom!"); 702470decc6SDave Kleikamp error = -ENOMEM; 703470decc6SDave Kleikamp jbd_lock_bh_state(bh); 704470decc6SDave Kleikamp goto done; 705470decc6SDave Kleikamp } 706470decc6SDave Kleikamp goto repeat; 707470decc6SDave Kleikamp } 708470decc6SDave Kleikamp jh->b_frozen_data = frozen_buffer; 709470decc6SDave Kleikamp frozen_buffer = NULL; 710470decc6SDave Kleikamp need_copy = 1; 711470decc6SDave Kleikamp } 712470decc6SDave Kleikamp jh->b_next_transaction = transaction; 713470decc6SDave Kleikamp } 714470decc6SDave Kleikamp 715470decc6SDave Kleikamp 716470decc6SDave Kleikamp /* 717470decc6SDave Kleikamp * Finally, if the buffer is not journaled right now, we need to make 718470decc6SDave Kleikamp * sure it doesn't get written to disk before the caller actually 719470decc6SDave Kleikamp * commits the new data 720470decc6SDave Kleikamp */ 721470decc6SDave Kleikamp if (!jh->b_transaction) { 722470decc6SDave Kleikamp JBUFFER_TRACE(jh, "no transaction"); 723470decc6SDave Kleikamp J_ASSERT_JH(jh, !jh->b_next_transaction); 724470decc6SDave Kleikamp jh->b_transaction = transaction; 725470decc6SDave Kleikamp JBUFFER_TRACE(jh, "file as BJ_Reserved"); 726470decc6SDave Kleikamp spin_lock(&journal->j_list_lock); 727f7f4bccbSMingming Cao __jbd2_journal_file_buffer(jh, transaction, BJ_Reserved); 728470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 729470decc6SDave Kleikamp } 730470decc6SDave Kleikamp 731470decc6SDave Kleikamp done: 732470decc6SDave Kleikamp if (need_copy) { 733470decc6SDave Kleikamp struct page *page; 734470decc6SDave Kleikamp int offset; 735470decc6SDave Kleikamp char *source; 736470decc6SDave Kleikamp 737470decc6SDave Kleikamp J_EXPECT_JH(jh, buffer_uptodate(jh2bh(jh)), 738470decc6SDave Kleikamp "Possible IO failure.\n"); 739470decc6SDave Kleikamp page = jh2bh(jh)->b_page; 740470decc6SDave Kleikamp offset = ((unsigned long) jh2bh(jh)->b_data) & ~PAGE_MASK; 741470decc6SDave Kleikamp source = kmap_atomic(page, KM_USER0); 742470decc6SDave Kleikamp memcpy(jh->b_frozen_data, source+offset, jh2bh(jh)->b_size); 743470decc6SDave Kleikamp kunmap_atomic(source, KM_USER0); 744e06c8227SJoel Becker 745e06c8227SJoel Becker /* 746e06c8227SJoel Becker * Now that the frozen data is saved off, we need to store 747e06c8227SJoel Becker * any matching triggers. 748e06c8227SJoel Becker */ 749e06c8227SJoel Becker jh->b_frozen_triggers = jh->b_triggers; 750470decc6SDave Kleikamp } 751470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 752470decc6SDave Kleikamp 753470decc6SDave Kleikamp /* 754470decc6SDave Kleikamp * If we are about to journal a buffer, then any revoke pending on it is 755470decc6SDave Kleikamp * no longer valid 756470decc6SDave Kleikamp */ 757f7f4bccbSMingming Cao jbd2_journal_cancel_revoke(handle, jh); 758470decc6SDave Kleikamp 759470decc6SDave Kleikamp out: 760470decc6SDave Kleikamp if (unlikely(frozen_buffer)) /* It's usually NULL */ 761af1e76d6SMingming Cao jbd2_free(frozen_buffer, bh->b_size); 762470decc6SDave Kleikamp 763470decc6SDave Kleikamp JBUFFER_TRACE(jh, "exit"); 764470decc6SDave Kleikamp return error; 765470decc6SDave Kleikamp } 766470decc6SDave Kleikamp 767470decc6SDave Kleikamp /** 768f7f4bccbSMingming Cao * int jbd2_journal_get_write_access() - notify intent to modify a buffer for metadata (not data) update. 769470decc6SDave Kleikamp * @handle: transaction to add buffer modifications to 770470decc6SDave Kleikamp * @bh: bh to be used for metadata writes 771470decc6SDave Kleikamp * @credits: variable that will receive credits for the buffer 772470decc6SDave Kleikamp * 773470decc6SDave Kleikamp * Returns an error code or 0 on success. 774470decc6SDave Kleikamp * 775470decc6SDave Kleikamp * In full data journalling mode the buffer may be of type BJ_AsyncData, 776470decc6SDave Kleikamp * because we're write()ing a buffer which is also part of a shared mapping. 777470decc6SDave Kleikamp */ 778470decc6SDave Kleikamp 779f7f4bccbSMingming Cao int jbd2_journal_get_write_access(handle_t *handle, struct buffer_head *bh) 780470decc6SDave Kleikamp { 781f7f4bccbSMingming Cao struct journal_head *jh = jbd2_journal_add_journal_head(bh); 782470decc6SDave Kleikamp int rc; 783470decc6SDave Kleikamp 784470decc6SDave Kleikamp /* We do not want to get caught playing with fields which the 785470decc6SDave Kleikamp * log thread also manipulates. Make sure that the buffer 786470decc6SDave Kleikamp * completes any outstanding IO before proceeding. */ 787470decc6SDave Kleikamp rc = do_get_write_access(handle, jh, 0); 788f7f4bccbSMingming Cao jbd2_journal_put_journal_head(jh); 789470decc6SDave Kleikamp return rc; 790470decc6SDave Kleikamp } 791470decc6SDave Kleikamp 792470decc6SDave Kleikamp 793470decc6SDave Kleikamp /* 794470decc6SDave Kleikamp * When the user wants to journal a newly created buffer_head 795470decc6SDave Kleikamp * (ie. getblk() returned a new buffer and we are going to populate it 796470decc6SDave Kleikamp * manually rather than reading off disk), then we need to keep the 797470decc6SDave Kleikamp * buffer_head locked until it has been completely filled with new 798470decc6SDave Kleikamp * data. In this case, we should be able to make the assertion that 799470decc6SDave Kleikamp * the bh is not already part of an existing transaction. 800470decc6SDave Kleikamp * 801470decc6SDave Kleikamp * The buffer should already be locked by the caller by this point. 802470decc6SDave Kleikamp * There is no lock ranking violation: it was a newly created, 803470decc6SDave Kleikamp * unlocked buffer beforehand. */ 804470decc6SDave Kleikamp 805470decc6SDave Kleikamp /** 806f7f4bccbSMingming Cao * int jbd2_journal_get_create_access () - notify intent to use newly created bh 807470decc6SDave Kleikamp * @handle: transaction to new buffer to 808470decc6SDave Kleikamp * @bh: new buffer. 809470decc6SDave Kleikamp * 810470decc6SDave Kleikamp * Call this if you create a new bh. 811470decc6SDave Kleikamp */ 812f7f4bccbSMingming Cao int jbd2_journal_get_create_access(handle_t *handle, struct buffer_head *bh) 813470decc6SDave Kleikamp { 814470decc6SDave Kleikamp transaction_t *transaction = handle->h_transaction; 815470decc6SDave Kleikamp journal_t *journal = transaction->t_journal; 816f7f4bccbSMingming Cao struct journal_head *jh = jbd2_journal_add_journal_head(bh); 817470decc6SDave Kleikamp int err; 818470decc6SDave Kleikamp 819470decc6SDave Kleikamp jbd_debug(5, "journal_head %p\n", jh); 820470decc6SDave Kleikamp err = -EROFS; 821470decc6SDave Kleikamp if (is_handle_aborted(handle)) 822470decc6SDave Kleikamp goto out; 823470decc6SDave Kleikamp err = 0; 824470decc6SDave Kleikamp 825470decc6SDave Kleikamp JBUFFER_TRACE(jh, "entry"); 826470decc6SDave Kleikamp /* 827470decc6SDave Kleikamp * The buffer may already belong to this transaction due to pre-zeroing 828470decc6SDave Kleikamp * in the filesystem's new_block code. It may also be on the previous, 829470decc6SDave Kleikamp * committing transaction's lists, but it HAS to be in Forget state in 830470decc6SDave Kleikamp * that case: the transaction must have deleted the buffer for it to be 831470decc6SDave Kleikamp * reused here. 832470decc6SDave Kleikamp */ 833470decc6SDave Kleikamp jbd_lock_bh_state(bh); 834470decc6SDave Kleikamp spin_lock(&journal->j_list_lock); 835470decc6SDave Kleikamp J_ASSERT_JH(jh, (jh->b_transaction == transaction || 836470decc6SDave Kleikamp jh->b_transaction == NULL || 837470decc6SDave Kleikamp (jh->b_transaction == journal->j_committing_transaction && 838470decc6SDave Kleikamp jh->b_jlist == BJ_Forget))); 839470decc6SDave Kleikamp 840470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_next_transaction == NULL); 841470decc6SDave Kleikamp J_ASSERT_JH(jh, buffer_locked(jh2bh(jh))); 842470decc6SDave Kleikamp 843470decc6SDave Kleikamp if (jh->b_transaction == NULL) { 844470decc6SDave Kleikamp jh->b_transaction = transaction; 8459fc7c63aSJosef Bacik 8469fc7c63aSJosef Bacik /* first access by this transaction */ 8479fc7c63aSJosef Bacik jh->b_modified = 0; 8489fc7c63aSJosef Bacik 849470decc6SDave Kleikamp JBUFFER_TRACE(jh, "file as BJ_Reserved"); 850f7f4bccbSMingming Cao __jbd2_journal_file_buffer(jh, transaction, BJ_Reserved); 851470decc6SDave Kleikamp } else if (jh->b_transaction == journal->j_committing_transaction) { 8529fc7c63aSJosef Bacik /* first access by this transaction */ 8539fc7c63aSJosef Bacik jh->b_modified = 0; 8549fc7c63aSJosef Bacik 855470decc6SDave Kleikamp JBUFFER_TRACE(jh, "set next transaction"); 856470decc6SDave Kleikamp jh->b_next_transaction = transaction; 857470decc6SDave Kleikamp } 858470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 859470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 860470decc6SDave Kleikamp 861470decc6SDave Kleikamp /* 862470decc6SDave Kleikamp * akpm: I added this. ext3_alloc_branch can pick up new indirect 863470decc6SDave Kleikamp * blocks which contain freed but then revoked metadata. We need 864470decc6SDave Kleikamp * to cancel the revoke in case we end up freeing it yet again 865470decc6SDave Kleikamp * and the reallocating as data - this would cause a second revoke, 866470decc6SDave Kleikamp * which hits an assertion error. 867470decc6SDave Kleikamp */ 868470decc6SDave Kleikamp JBUFFER_TRACE(jh, "cancelling revoke"); 869f7f4bccbSMingming Cao jbd2_journal_cancel_revoke(handle, jh); 870f7f4bccbSMingming Cao jbd2_journal_put_journal_head(jh); 871470decc6SDave Kleikamp out: 872470decc6SDave Kleikamp return err; 873470decc6SDave Kleikamp } 874470decc6SDave Kleikamp 875470decc6SDave Kleikamp /** 876f7f4bccbSMingming Cao * int jbd2_journal_get_undo_access() - Notify intent to modify metadata with 877470decc6SDave Kleikamp * non-rewindable consequences 878470decc6SDave Kleikamp * @handle: transaction 879470decc6SDave Kleikamp * @bh: buffer to undo 880470decc6SDave Kleikamp * @credits: store the number of taken credits here (if not NULL) 881470decc6SDave Kleikamp * 882470decc6SDave Kleikamp * Sometimes there is a need to distinguish between metadata which has 883470decc6SDave Kleikamp * been committed to disk and that which has not. The ext3fs code uses 884470decc6SDave Kleikamp * this for freeing and allocating space, we have to make sure that we 885470decc6SDave Kleikamp * do not reuse freed space until the deallocation has been committed, 886470decc6SDave Kleikamp * since if we overwrote that space we would make the delete 887470decc6SDave Kleikamp * un-rewindable in case of a crash. 888470decc6SDave Kleikamp * 889f7f4bccbSMingming Cao * To deal with that, jbd2_journal_get_undo_access requests write access to a 890470decc6SDave Kleikamp * buffer for parts of non-rewindable operations such as delete 891470decc6SDave Kleikamp * operations on the bitmaps. The journaling code must keep a copy of 892470decc6SDave Kleikamp * the buffer's contents prior to the undo_access call until such time 893470decc6SDave Kleikamp * as we know that the buffer has definitely been committed to disk. 894470decc6SDave Kleikamp * 895470decc6SDave Kleikamp * We never need to know which transaction the committed data is part 896470decc6SDave Kleikamp * of, buffers touched here are guaranteed to be dirtied later and so 897470decc6SDave Kleikamp * will be committed to a new transaction in due course, at which point 898470decc6SDave Kleikamp * we can discard the old committed data pointer. 899470decc6SDave Kleikamp * 900470decc6SDave Kleikamp * Returns error number or 0 on success. 901470decc6SDave Kleikamp */ 902f7f4bccbSMingming Cao int jbd2_journal_get_undo_access(handle_t *handle, struct buffer_head *bh) 903470decc6SDave Kleikamp { 904470decc6SDave Kleikamp int err; 905f7f4bccbSMingming Cao struct journal_head *jh = jbd2_journal_add_journal_head(bh); 906470decc6SDave Kleikamp char *committed_data = NULL; 907470decc6SDave Kleikamp 908470decc6SDave Kleikamp JBUFFER_TRACE(jh, "entry"); 909470decc6SDave Kleikamp 910470decc6SDave Kleikamp /* 911470decc6SDave Kleikamp * Do this first --- it can drop the journal lock, so we want to 912470decc6SDave Kleikamp * make sure that obtaining the committed_data is done 913470decc6SDave Kleikamp * atomically wrt. completion of any outstanding commits. 914470decc6SDave Kleikamp */ 915470decc6SDave Kleikamp err = do_get_write_access(handle, jh, 1); 916470decc6SDave Kleikamp if (err) 917470decc6SDave Kleikamp goto out; 918470decc6SDave Kleikamp 919470decc6SDave Kleikamp repeat: 920470decc6SDave Kleikamp if (!jh->b_committed_data) { 921af1e76d6SMingming Cao committed_data = jbd2_alloc(jh2bh(jh)->b_size, GFP_NOFS); 922470decc6SDave Kleikamp if (!committed_data) { 923470decc6SDave Kleikamp printk(KERN_EMERG "%s: No memory for committed data\n", 924329d291fSHarvey Harrison __func__); 925470decc6SDave Kleikamp err = -ENOMEM; 926470decc6SDave Kleikamp goto out; 927470decc6SDave Kleikamp } 928470decc6SDave Kleikamp } 929470decc6SDave Kleikamp 930470decc6SDave Kleikamp jbd_lock_bh_state(bh); 931470decc6SDave Kleikamp if (!jh->b_committed_data) { 932470decc6SDave Kleikamp /* Copy out the current buffer contents into the 933470decc6SDave Kleikamp * preserved, committed copy. */ 934470decc6SDave Kleikamp JBUFFER_TRACE(jh, "generate b_committed data"); 935470decc6SDave Kleikamp if (!committed_data) { 936470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 937470decc6SDave Kleikamp goto repeat; 938470decc6SDave Kleikamp } 939470decc6SDave Kleikamp 940470decc6SDave Kleikamp jh->b_committed_data = committed_data; 941470decc6SDave Kleikamp committed_data = NULL; 942470decc6SDave Kleikamp memcpy(jh->b_committed_data, bh->b_data, bh->b_size); 943470decc6SDave Kleikamp } 944470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 945470decc6SDave Kleikamp out: 946f7f4bccbSMingming Cao jbd2_journal_put_journal_head(jh); 947470decc6SDave Kleikamp if (unlikely(committed_data)) 948af1e76d6SMingming Cao jbd2_free(committed_data, bh->b_size); 949470decc6SDave Kleikamp return err; 950470decc6SDave Kleikamp } 951470decc6SDave Kleikamp 952470decc6SDave Kleikamp /** 953e06c8227SJoel Becker * void jbd2_journal_set_triggers() - Add triggers for commit writeout 954e06c8227SJoel Becker * @bh: buffer to trigger on 955e06c8227SJoel Becker * @type: struct jbd2_buffer_trigger_type containing the trigger(s). 956e06c8227SJoel Becker * 957e06c8227SJoel Becker * Set any triggers on this journal_head. This is always safe, because 958e06c8227SJoel Becker * triggers for a committing buffer will be saved off, and triggers for 959e06c8227SJoel Becker * a running transaction will match the buffer in that transaction. 960e06c8227SJoel Becker * 961e06c8227SJoel Becker * Call with NULL to clear the triggers. 962e06c8227SJoel Becker */ 963e06c8227SJoel Becker void jbd2_journal_set_triggers(struct buffer_head *bh, 964e06c8227SJoel Becker struct jbd2_buffer_trigger_type *type) 965e06c8227SJoel Becker { 966e06c8227SJoel Becker struct journal_head *jh = bh2jh(bh); 967e06c8227SJoel Becker 968e06c8227SJoel Becker jh->b_triggers = type; 969e06c8227SJoel Becker } 970e06c8227SJoel Becker 971e06c8227SJoel Becker void jbd2_buffer_commit_trigger(struct journal_head *jh, void *mapped_data, 972e06c8227SJoel Becker struct jbd2_buffer_trigger_type *triggers) 973e06c8227SJoel Becker { 974e06c8227SJoel Becker struct buffer_head *bh = jh2bh(jh); 975e06c8227SJoel Becker 976e06c8227SJoel Becker if (!triggers || !triggers->t_commit) 977e06c8227SJoel Becker return; 978e06c8227SJoel Becker 979e06c8227SJoel Becker triggers->t_commit(triggers, bh, mapped_data, bh->b_size); 980e06c8227SJoel Becker } 981e06c8227SJoel Becker 982e06c8227SJoel Becker void jbd2_buffer_abort_trigger(struct journal_head *jh, 983e06c8227SJoel Becker struct jbd2_buffer_trigger_type *triggers) 984e06c8227SJoel Becker { 985e06c8227SJoel Becker if (!triggers || !triggers->t_abort) 986e06c8227SJoel Becker return; 987e06c8227SJoel Becker 988e06c8227SJoel Becker triggers->t_abort(triggers, jh2bh(jh)); 989e06c8227SJoel Becker } 990e06c8227SJoel Becker 991e06c8227SJoel Becker 992e06c8227SJoel Becker 993e06c8227SJoel Becker /** 994f7f4bccbSMingming Cao * int jbd2_journal_dirty_metadata() - mark a buffer as containing dirty metadata 995470decc6SDave Kleikamp * @handle: transaction to add buffer to. 996470decc6SDave Kleikamp * @bh: buffer to mark 997470decc6SDave Kleikamp * 998470decc6SDave Kleikamp * mark dirty metadata which needs to be journaled as part of the current 999470decc6SDave Kleikamp * transaction. 1000470decc6SDave Kleikamp * 1001470decc6SDave Kleikamp * The buffer is placed on the transaction's metadata list and is marked 1002470decc6SDave Kleikamp * as belonging to the transaction. 1003470decc6SDave Kleikamp * 1004470decc6SDave Kleikamp * Returns error number or 0 on success. 1005470decc6SDave Kleikamp * 1006470decc6SDave Kleikamp * Special care needs to be taken if the buffer already belongs to the 1007470decc6SDave Kleikamp * current committing transaction (in which case we should have frozen 1008470decc6SDave Kleikamp * data present for that commit). In that case, we don't relink the 1009470decc6SDave Kleikamp * buffer: that only gets done when the old transaction finally 1010470decc6SDave Kleikamp * completes its commit. 1011470decc6SDave Kleikamp */ 1012f7f4bccbSMingming Cao int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh) 1013470decc6SDave Kleikamp { 1014470decc6SDave Kleikamp transaction_t *transaction = handle->h_transaction; 1015470decc6SDave Kleikamp journal_t *journal = transaction->t_journal; 1016470decc6SDave Kleikamp struct journal_head *jh = bh2jh(bh); 1017470decc6SDave Kleikamp 1018470decc6SDave Kleikamp jbd_debug(5, "journal_head %p\n", jh); 1019470decc6SDave Kleikamp JBUFFER_TRACE(jh, "entry"); 1020470decc6SDave Kleikamp if (is_handle_aborted(handle)) 1021470decc6SDave Kleikamp goto out; 1022470decc6SDave Kleikamp 1023470decc6SDave Kleikamp jbd_lock_bh_state(bh); 1024470decc6SDave Kleikamp 1025470decc6SDave Kleikamp if (jh->b_modified == 0) { 1026470decc6SDave Kleikamp /* 1027470decc6SDave Kleikamp * This buffer's got modified and becoming part 1028470decc6SDave Kleikamp * of the transaction. This needs to be done 1029470decc6SDave Kleikamp * once a transaction -bzzz 1030470decc6SDave Kleikamp */ 1031470decc6SDave Kleikamp jh->b_modified = 1; 1032470decc6SDave Kleikamp J_ASSERT_JH(jh, handle->h_buffer_credits > 0); 1033470decc6SDave Kleikamp handle->h_buffer_credits--; 1034470decc6SDave Kleikamp } 1035470decc6SDave Kleikamp 1036470decc6SDave Kleikamp /* 1037470decc6SDave Kleikamp * fastpath, to avoid expensive locking. If this buffer is already 1038470decc6SDave Kleikamp * on the running transaction's metadata list there is nothing to do. 1039470decc6SDave Kleikamp * Nobody can take it off again because there is a handle open. 1040470decc6SDave Kleikamp * I _think_ we're OK here with SMP barriers - a mistaken decision will 1041470decc6SDave Kleikamp * result in this test being false, so we go in and take the locks. 1042470decc6SDave Kleikamp */ 1043470decc6SDave Kleikamp if (jh->b_transaction == transaction && jh->b_jlist == BJ_Metadata) { 1044470decc6SDave Kleikamp JBUFFER_TRACE(jh, "fastpath"); 1045470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_transaction == 1046470decc6SDave Kleikamp journal->j_running_transaction); 1047470decc6SDave Kleikamp goto out_unlock_bh; 1048470decc6SDave Kleikamp } 1049470decc6SDave Kleikamp 1050470decc6SDave Kleikamp set_buffer_jbddirty(bh); 1051470decc6SDave Kleikamp 1052470decc6SDave Kleikamp /* 1053470decc6SDave Kleikamp * Metadata already on the current transaction list doesn't 1054470decc6SDave Kleikamp * need to be filed. Metadata on another transaction's list must 1055470decc6SDave Kleikamp * be committing, and will be refiled once the commit completes: 1056470decc6SDave Kleikamp * leave it alone for now. 1057470decc6SDave Kleikamp */ 1058470decc6SDave Kleikamp if (jh->b_transaction != transaction) { 1059470decc6SDave Kleikamp JBUFFER_TRACE(jh, "already on other transaction"); 1060470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_transaction == 1061470decc6SDave Kleikamp journal->j_committing_transaction); 1062470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_next_transaction == transaction); 1063470decc6SDave Kleikamp /* And this case is illegal: we can't reuse another 1064470decc6SDave Kleikamp * transaction's data buffer, ever. */ 1065470decc6SDave Kleikamp goto out_unlock_bh; 1066470decc6SDave Kleikamp } 1067470decc6SDave Kleikamp 1068470decc6SDave Kleikamp /* That test should have eliminated the following case: */ 10694019191bSMingming Cao J_ASSERT_JH(jh, jh->b_frozen_data == NULL); 1070470decc6SDave Kleikamp 1071470decc6SDave Kleikamp JBUFFER_TRACE(jh, "file as BJ_Metadata"); 1072470decc6SDave Kleikamp spin_lock(&journal->j_list_lock); 1073f7f4bccbSMingming Cao __jbd2_journal_file_buffer(jh, handle->h_transaction, BJ_Metadata); 1074470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 1075470decc6SDave Kleikamp out_unlock_bh: 1076470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 1077470decc6SDave Kleikamp out: 1078470decc6SDave Kleikamp JBUFFER_TRACE(jh, "exit"); 1079470decc6SDave Kleikamp return 0; 1080470decc6SDave Kleikamp } 1081470decc6SDave Kleikamp 1082470decc6SDave Kleikamp /* 1083f7f4bccbSMingming Cao * jbd2_journal_release_buffer: undo a get_write_access without any buffer 1084470decc6SDave Kleikamp * updates, if the update decided in the end that it didn't need access. 1085470decc6SDave Kleikamp * 1086470decc6SDave Kleikamp */ 1087470decc6SDave Kleikamp void 1088f7f4bccbSMingming Cao jbd2_journal_release_buffer(handle_t *handle, struct buffer_head *bh) 1089470decc6SDave Kleikamp { 1090470decc6SDave Kleikamp BUFFER_TRACE(bh, "entry"); 1091470decc6SDave Kleikamp } 1092470decc6SDave Kleikamp 1093470decc6SDave Kleikamp /** 1094f7f4bccbSMingming Cao * void jbd2_journal_forget() - bforget() for potentially-journaled buffers. 1095470decc6SDave Kleikamp * @handle: transaction handle 1096470decc6SDave Kleikamp * @bh: bh to 'forget' 1097470decc6SDave Kleikamp * 1098470decc6SDave Kleikamp * We can only do the bforget if there are no commits pending against the 1099470decc6SDave Kleikamp * buffer. If the buffer is dirty in the current running transaction we 1100470decc6SDave Kleikamp * can safely unlink it. 1101470decc6SDave Kleikamp * 1102470decc6SDave Kleikamp * bh may not be a journalled buffer at all - it may be a non-JBD 1103470decc6SDave Kleikamp * buffer which came off the hashtable. Check for this. 1104470decc6SDave Kleikamp * 1105470decc6SDave Kleikamp * Decrements bh->b_count by one. 1106470decc6SDave Kleikamp * 1107470decc6SDave Kleikamp * Allow this call even if the handle has aborted --- it may be part of 1108470decc6SDave Kleikamp * the caller's cleanup after an abort. 1109470decc6SDave Kleikamp */ 1110f7f4bccbSMingming Cao int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh) 1111470decc6SDave Kleikamp { 1112470decc6SDave Kleikamp transaction_t *transaction = handle->h_transaction; 1113470decc6SDave Kleikamp journal_t *journal = transaction->t_journal; 1114470decc6SDave Kleikamp struct journal_head *jh; 1115470decc6SDave Kleikamp int drop_reserve = 0; 1116470decc6SDave Kleikamp int err = 0; 11171dfc3220SJosef Bacik int was_modified = 0; 1118470decc6SDave Kleikamp 1119470decc6SDave Kleikamp BUFFER_TRACE(bh, "entry"); 1120470decc6SDave Kleikamp 1121470decc6SDave Kleikamp jbd_lock_bh_state(bh); 1122470decc6SDave Kleikamp spin_lock(&journal->j_list_lock); 1123470decc6SDave Kleikamp 1124470decc6SDave Kleikamp if (!buffer_jbd(bh)) 1125470decc6SDave Kleikamp goto not_jbd; 1126470decc6SDave Kleikamp jh = bh2jh(bh); 1127470decc6SDave Kleikamp 1128470decc6SDave Kleikamp /* Critical error: attempting to delete a bitmap buffer, maybe? 1129470decc6SDave Kleikamp * Don't do any jbd operations, and return an error. */ 1130470decc6SDave Kleikamp if (!J_EXPECT_JH(jh, !jh->b_committed_data, 1131470decc6SDave Kleikamp "inconsistent data on disk")) { 1132470decc6SDave Kleikamp err = -EIO; 1133470decc6SDave Kleikamp goto not_jbd; 1134470decc6SDave Kleikamp } 1135470decc6SDave Kleikamp 11361dfc3220SJosef Bacik /* keep track of wether or not this transaction modified us */ 11371dfc3220SJosef Bacik was_modified = jh->b_modified; 11381dfc3220SJosef Bacik 1139470decc6SDave Kleikamp /* 1140470decc6SDave Kleikamp * The buffer's going from the transaction, we must drop 1141470decc6SDave Kleikamp * all references -bzzz 1142470decc6SDave Kleikamp */ 1143470decc6SDave Kleikamp jh->b_modified = 0; 1144470decc6SDave Kleikamp 1145470decc6SDave Kleikamp if (jh->b_transaction == handle->h_transaction) { 1146470decc6SDave Kleikamp J_ASSERT_JH(jh, !jh->b_frozen_data); 1147470decc6SDave Kleikamp 1148470decc6SDave Kleikamp /* If we are forgetting a buffer which is already part 1149470decc6SDave Kleikamp * of this transaction, then we can just drop it from 1150470decc6SDave Kleikamp * the transaction immediately. */ 1151470decc6SDave Kleikamp clear_buffer_dirty(bh); 1152470decc6SDave Kleikamp clear_buffer_jbddirty(bh); 1153470decc6SDave Kleikamp 1154470decc6SDave Kleikamp JBUFFER_TRACE(jh, "belongs to current transaction: unfile"); 1155470decc6SDave Kleikamp 11561dfc3220SJosef Bacik /* 11571dfc3220SJosef Bacik * we only want to drop a reference if this transaction 11581dfc3220SJosef Bacik * modified the buffer 11591dfc3220SJosef Bacik */ 11601dfc3220SJosef Bacik if (was_modified) 1161470decc6SDave Kleikamp drop_reserve = 1; 1162470decc6SDave Kleikamp 1163470decc6SDave Kleikamp /* 1164470decc6SDave Kleikamp * We are no longer going to journal this buffer. 1165470decc6SDave Kleikamp * However, the commit of this transaction is still 1166470decc6SDave Kleikamp * important to the buffer: the delete that we are now 1167470decc6SDave Kleikamp * processing might obsolete an old log entry, so by 1168470decc6SDave Kleikamp * committing, we can satisfy the buffer's checkpoint. 1169470decc6SDave Kleikamp * 1170470decc6SDave Kleikamp * So, if we have a checkpoint on the buffer, we should 1171470decc6SDave Kleikamp * now refile the buffer on our BJ_Forget list so that 1172470decc6SDave Kleikamp * we know to remove the checkpoint after we commit. 1173470decc6SDave Kleikamp */ 1174470decc6SDave Kleikamp 1175470decc6SDave Kleikamp if (jh->b_cp_transaction) { 1176f7f4bccbSMingming Cao __jbd2_journal_temp_unlink_buffer(jh); 1177f7f4bccbSMingming Cao __jbd2_journal_file_buffer(jh, transaction, BJ_Forget); 1178470decc6SDave Kleikamp } else { 1179f7f4bccbSMingming Cao __jbd2_journal_unfile_buffer(jh); 1180f7f4bccbSMingming Cao jbd2_journal_remove_journal_head(bh); 1181470decc6SDave Kleikamp __brelse(bh); 1182470decc6SDave Kleikamp if (!buffer_jbd(bh)) { 1183470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 1184470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 1185470decc6SDave Kleikamp __bforget(bh); 1186470decc6SDave Kleikamp goto drop; 1187470decc6SDave Kleikamp } 1188470decc6SDave Kleikamp } 1189470decc6SDave Kleikamp } else if (jh->b_transaction) { 1190470decc6SDave Kleikamp J_ASSERT_JH(jh, (jh->b_transaction == 1191470decc6SDave Kleikamp journal->j_committing_transaction)); 1192470decc6SDave Kleikamp /* However, if the buffer is still owned by a prior 1193470decc6SDave Kleikamp * (committing) transaction, we can't drop it yet... */ 1194470decc6SDave Kleikamp JBUFFER_TRACE(jh, "belongs to older transaction"); 1195470decc6SDave Kleikamp /* ... but we CAN drop it from the new transaction if we 1196470decc6SDave Kleikamp * have also modified it since the original commit. */ 1197470decc6SDave Kleikamp 1198470decc6SDave Kleikamp if (jh->b_next_transaction) { 1199470decc6SDave Kleikamp J_ASSERT(jh->b_next_transaction == transaction); 1200470decc6SDave Kleikamp jh->b_next_transaction = NULL; 12011dfc3220SJosef Bacik 12021dfc3220SJosef Bacik /* 12031dfc3220SJosef Bacik * only drop a reference if this transaction modified 12041dfc3220SJosef Bacik * the buffer 12051dfc3220SJosef Bacik */ 12061dfc3220SJosef Bacik if (was_modified) 1207470decc6SDave Kleikamp drop_reserve = 1; 1208470decc6SDave Kleikamp } 1209470decc6SDave Kleikamp } 1210470decc6SDave Kleikamp 1211470decc6SDave Kleikamp not_jbd: 1212470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 1213470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 1214470decc6SDave Kleikamp __brelse(bh); 1215470decc6SDave Kleikamp drop: 1216470decc6SDave Kleikamp if (drop_reserve) { 1217470decc6SDave Kleikamp /* no need to reserve log space for this block -bzzz */ 1218470decc6SDave Kleikamp handle->h_buffer_credits++; 1219470decc6SDave Kleikamp } 1220470decc6SDave Kleikamp return err; 1221470decc6SDave Kleikamp } 1222470decc6SDave Kleikamp 1223470decc6SDave Kleikamp /** 1224f7f4bccbSMingming Cao * int jbd2_journal_stop() - complete a transaction 1225470decc6SDave Kleikamp * @handle: tranaction to complete. 1226470decc6SDave Kleikamp * 1227470decc6SDave Kleikamp * All done for a particular handle. 1228470decc6SDave Kleikamp * 1229470decc6SDave Kleikamp * There is not much action needed here. We just return any remaining 1230470decc6SDave Kleikamp * buffer credits to the transaction and remove the handle. The only 1231470decc6SDave Kleikamp * complication is that we need to start a commit operation if the 1232470decc6SDave Kleikamp * filesystem is marked for synchronous update. 1233470decc6SDave Kleikamp * 1234f7f4bccbSMingming Cao * jbd2_journal_stop itself will not usually return an error, but it may 1235470decc6SDave Kleikamp * do so in unusual circumstances. In particular, expect it to 1236f7f4bccbSMingming Cao * return -EIO if a jbd2_journal_abort has been executed since the 1237470decc6SDave Kleikamp * transaction began. 1238470decc6SDave Kleikamp */ 1239f7f4bccbSMingming Cao int jbd2_journal_stop(handle_t *handle) 1240470decc6SDave Kleikamp { 1241470decc6SDave Kleikamp transaction_t *transaction = handle->h_transaction; 1242470decc6SDave Kleikamp journal_t *journal = transaction->t_journal; 1243470decc6SDave Kleikamp int old_handle_count, err; 1244470decc6SDave Kleikamp pid_t pid; 1245470decc6SDave Kleikamp 1246470decc6SDave Kleikamp J_ASSERT(journal_current_handle() == handle); 1247470decc6SDave Kleikamp 1248470decc6SDave Kleikamp if (is_handle_aborted(handle)) 1249470decc6SDave Kleikamp err = -EIO; 12503e2a532bSOGAWA Hirofumi else { 12513e2a532bSOGAWA Hirofumi J_ASSERT(transaction->t_updates > 0); 1252470decc6SDave Kleikamp err = 0; 12533e2a532bSOGAWA Hirofumi } 1254470decc6SDave Kleikamp 1255470decc6SDave Kleikamp if (--handle->h_ref > 0) { 1256470decc6SDave Kleikamp jbd_debug(4, "h_ref %d -> %d\n", handle->h_ref + 1, 1257470decc6SDave Kleikamp handle->h_ref); 1258470decc6SDave Kleikamp return err; 1259470decc6SDave Kleikamp } 1260470decc6SDave Kleikamp 1261470decc6SDave Kleikamp jbd_debug(4, "Handle %p going down\n", handle); 1262470decc6SDave Kleikamp 1263470decc6SDave Kleikamp /* 1264470decc6SDave Kleikamp * Implement synchronous transaction batching. If the handle 1265470decc6SDave Kleikamp * was synchronous, don't force a commit immediately. Let's 1266470decc6SDave Kleikamp * yield and let another thread piggyback onto this transaction. 1267470decc6SDave Kleikamp * Keep doing that while new threads continue to arrive. 1268470decc6SDave Kleikamp * It doesn't cost much - we're about to run a commit and sleep 1269470decc6SDave Kleikamp * on IO anyway. Speeds up many-threaded, many-dir operations 1270470decc6SDave Kleikamp * by 30x or more... 1271470decc6SDave Kleikamp * 1272470decc6SDave Kleikamp * But don't do this if this process was the most recent one to 1273470decc6SDave Kleikamp * perform a synchronous write. We do this to detect the case where a 1274470decc6SDave Kleikamp * single process is doing a stream of sync writes. No point in waiting 1275470decc6SDave Kleikamp * for joiners in that case. 1276470decc6SDave Kleikamp */ 1277470decc6SDave Kleikamp pid = current->pid; 1278470decc6SDave Kleikamp if (handle->h_sync && journal->j_last_sync_writer != pid) { 1279470decc6SDave Kleikamp journal->j_last_sync_writer = pid; 1280470decc6SDave Kleikamp do { 1281470decc6SDave Kleikamp old_handle_count = transaction->t_handle_count; 1282470decc6SDave Kleikamp schedule_timeout_uninterruptible(1); 1283470decc6SDave Kleikamp } while (old_handle_count != transaction->t_handle_count); 1284470decc6SDave Kleikamp } 1285470decc6SDave Kleikamp 1286470decc6SDave Kleikamp current->journal_info = NULL; 1287470decc6SDave Kleikamp spin_lock(&journal->j_state_lock); 1288470decc6SDave Kleikamp spin_lock(&transaction->t_handle_lock); 1289470decc6SDave Kleikamp transaction->t_outstanding_credits -= handle->h_buffer_credits; 1290470decc6SDave Kleikamp transaction->t_updates--; 1291470decc6SDave Kleikamp if (!transaction->t_updates) { 1292470decc6SDave Kleikamp wake_up(&journal->j_wait_updates); 1293470decc6SDave Kleikamp if (journal->j_barrier_count) 1294470decc6SDave Kleikamp wake_up(&journal->j_wait_transaction_locked); 1295470decc6SDave Kleikamp } 1296470decc6SDave Kleikamp 1297470decc6SDave Kleikamp /* 1298470decc6SDave Kleikamp * If the handle is marked SYNC, we need to set another commit 1299470decc6SDave Kleikamp * going! We also want to force a commit if the current 1300470decc6SDave Kleikamp * transaction is occupying too much of the log, or if the 1301470decc6SDave Kleikamp * transaction is too old now. 1302470decc6SDave Kleikamp */ 1303470decc6SDave Kleikamp if (handle->h_sync || 1304470decc6SDave Kleikamp transaction->t_outstanding_credits > 1305470decc6SDave Kleikamp journal->j_max_transaction_buffers || 1306470decc6SDave Kleikamp time_after_eq(jiffies, transaction->t_expires)) { 1307470decc6SDave Kleikamp /* Do this even for aborted journals: an abort still 1308470decc6SDave Kleikamp * completes the commit thread, it just doesn't write 1309470decc6SDave Kleikamp * anything to disk. */ 1310470decc6SDave Kleikamp tid_t tid = transaction->t_tid; 1311470decc6SDave Kleikamp 1312470decc6SDave Kleikamp spin_unlock(&transaction->t_handle_lock); 1313470decc6SDave Kleikamp jbd_debug(2, "transaction too old, requesting commit for " 1314470decc6SDave Kleikamp "handle %p\n", handle); 1315470decc6SDave Kleikamp /* This is non-blocking */ 1316f7f4bccbSMingming Cao __jbd2_log_start_commit(journal, transaction->t_tid); 1317470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 1318470decc6SDave Kleikamp 1319470decc6SDave Kleikamp /* 1320f7f4bccbSMingming Cao * Special case: JBD2_SYNC synchronous updates require us 1321470decc6SDave Kleikamp * to wait for the commit to complete. 1322470decc6SDave Kleikamp */ 1323470decc6SDave Kleikamp if (handle->h_sync && !(current->flags & PF_MEMALLOC)) 1324f7f4bccbSMingming Cao err = jbd2_log_wait_commit(journal, tid); 1325470decc6SDave Kleikamp } else { 1326470decc6SDave Kleikamp spin_unlock(&transaction->t_handle_lock); 1327470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 1328470decc6SDave Kleikamp } 1329470decc6SDave Kleikamp 13303295f0efSIngo Molnar lock_map_release(&handle->h_lockdep_map); 13317b751066SMingming Cao 1332af1e76d6SMingming Cao jbd2_free_handle(handle); 1333470decc6SDave Kleikamp return err; 1334470decc6SDave Kleikamp } 1335470decc6SDave Kleikamp 13365648ba5bSRandy Dunlap /** 13375648ba5bSRandy Dunlap * int jbd2_journal_force_commit() - force any uncommitted transactions 1338470decc6SDave Kleikamp * @journal: journal to force 1339470decc6SDave Kleikamp * 1340470decc6SDave Kleikamp * For synchronous operations: force any uncommitted transactions 1341470decc6SDave Kleikamp * to disk. May seem kludgy, but it reuses all the handle batching 1342470decc6SDave Kleikamp * code in a very simple manner. 1343470decc6SDave Kleikamp */ 1344f7f4bccbSMingming Cao int jbd2_journal_force_commit(journal_t *journal) 1345470decc6SDave Kleikamp { 1346470decc6SDave Kleikamp handle_t *handle; 1347470decc6SDave Kleikamp int ret; 1348470decc6SDave Kleikamp 1349f7f4bccbSMingming Cao handle = jbd2_journal_start(journal, 1); 1350470decc6SDave Kleikamp if (IS_ERR(handle)) { 1351470decc6SDave Kleikamp ret = PTR_ERR(handle); 1352470decc6SDave Kleikamp } else { 1353470decc6SDave Kleikamp handle->h_sync = 1; 1354f7f4bccbSMingming Cao ret = jbd2_journal_stop(handle); 1355470decc6SDave Kleikamp } 1356470decc6SDave Kleikamp return ret; 1357470decc6SDave Kleikamp } 1358470decc6SDave Kleikamp 1359470decc6SDave Kleikamp /* 1360470decc6SDave Kleikamp * 1361470decc6SDave Kleikamp * List management code snippets: various functions for manipulating the 1362470decc6SDave Kleikamp * transaction buffer lists. 1363470decc6SDave Kleikamp * 1364470decc6SDave Kleikamp */ 1365470decc6SDave Kleikamp 1366470decc6SDave Kleikamp /* 1367470decc6SDave Kleikamp * Append a buffer to a transaction list, given the transaction's list head 1368470decc6SDave Kleikamp * pointer. 1369470decc6SDave Kleikamp * 1370470decc6SDave Kleikamp * j_list_lock is held. 1371470decc6SDave Kleikamp * 1372470decc6SDave Kleikamp * jbd_lock_bh_state(jh2bh(jh)) is held. 1373470decc6SDave Kleikamp */ 1374470decc6SDave Kleikamp 1375470decc6SDave Kleikamp static inline void 1376470decc6SDave Kleikamp __blist_add_buffer(struct journal_head **list, struct journal_head *jh) 1377470decc6SDave Kleikamp { 1378470decc6SDave Kleikamp if (!*list) { 1379470decc6SDave Kleikamp jh->b_tnext = jh->b_tprev = jh; 1380470decc6SDave Kleikamp *list = jh; 1381470decc6SDave Kleikamp } else { 1382470decc6SDave Kleikamp /* Insert at the tail of the list to preserve order */ 1383470decc6SDave Kleikamp struct journal_head *first = *list, *last = first->b_tprev; 1384470decc6SDave Kleikamp jh->b_tprev = last; 1385470decc6SDave Kleikamp jh->b_tnext = first; 1386470decc6SDave Kleikamp last->b_tnext = first->b_tprev = jh; 1387470decc6SDave Kleikamp } 1388470decc6SDave Kleikamp } 1389470decc6SDave Kleikamp 1390470decc6SDave Kleikamp /* 1391470decc6SDave Kleikamp * Remove a buffer from a transaction list, given the transaction's list 1392470decc6SDave Kleikamp * head pointer. 1393470decc6SDave Kleikamp * 1394470decc6SDave Kleikamp * Called with j_list_lock held, and the journal may not be locked. 1395470decc6SDave Kleikamp * 1396470decc6SDave Kleikamp * jbd_lock_bh_state(jh2bh(jh)) is held. 1397470decc6SDave Kleikamp */ 1398470decc6SDave Kleikamp 1399470decc6SDave Kleikamp static inline void 1400470decc6SDave Kleikamp __blist_del_buffer(struct journal_head **list, struct journal_head *jh) 1401470decc6SDave Kleikamp { 1402470decc6SDave Kleikamp if (*list == jh) { 1403470decc6SDave Kleikamp *list = jh->b_tnext; 1404470decc6SDave Kleikamp if (*list == jh) 1405470decc6SDave Kleikamp *list = NULL; 1406470decc6SDave Kleikamp } 1407470decc6SDave Kleikamp jh->b_tprev->b_tnext = jh->b_tnext; 1408470decc6SDave Kleikamp jh->b_tnext->b_tprev = jh->b_tprev; 1409470decc6SDave Kleikamp } 1410470decc6SDave Kleikamp 1411470decc6SDave Kleikamp /* 1412470decc6SDave Kleikamp * Remove a buffer from the appropriate transaction list. 1413470decc6SDave Kleikamp * 1414470decc6SDave Kleikamp * Note that this function can *change* the value of 141587c89c23SJan Kara * bh->b_transaction->t_buffers, t_forget, t_iobuf_list, t_shadow_list, 141687c89c23SJan Kara * t_log_list or t_reserved_list. If the caller is holding onto a copy of one 141787c89c23SJan Kara * of these pointers, it could go bad. Generally the caller needs to re-read 141887c89c23SJan Kara * the pointer from the transaction_t. 1419470decc6SDave Kleikamp * 1420470decc6SDave Kleikamp * Called under j_list_lock. The journal may not be locked. 1421470decc6SDave Kleikamp */ 1422f7f4bccbSMingming Cao void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh) 1423470decc6SDave Kleikamp { 1424470decc6SDave Kleikamp struct journal_head **list = NULL; 1425470decc6SDave Kleikamp transaction_t *transaction; 1426470decc6SDave Kleikamp struct buffer_head *bh = jh2bh(jh); 1427470decc6SDave Kleikamp 1428470decc6SDave Kleikamp J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh)); 1429470decc6SDave Kleikamp transaction = jh->b_transaction; 1430470decc6SDave Kleikamp if (transaction) 1431470decc6SDave Kleikamp assert_spin_locked(&transaction->t_journal->j_list_lock); 1432470decc6SDave Kleikamp 1433470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_jlist < BJ_Types); 1434470decc6SDave Kleikamp if (jh->b_jlist != BJ_None) 14354019191bSMingming Cao J_ASSERT_JH(jh, transaction != NULL); 1436470decc6SDave Kleikamp 1437470decc6SDave Kleikamp switch (jh->b_jlist) { 1438470decc6SDave Kleikamp case BJ_None: 1439470decc6SDave Kleikamp return; 1440470decc6SDave Kleikamp case BJ_Metadata: 1441470decc6SDave Kleikamp transaction->t_nr_buffers--; 1442470decc6SDave Kleikamp J_ASSERT_JH(jh, transaction->t_nr_buffers >= 0); 1443470decc6SDave Kleikamp list = &transaction->t_buffers; 1444470decc6SDave Kleikamp break; 1445470decc6SDave Kleikamp case BJ_Forget: 1446470decc6SDave Kleikamp list = &transaction->t_forget; 1447470decc6SDave Kleikamp break; 1448470decc6SDave Kleikamp case BJ_IO: 1449470decc6SDave Kleikamp list = &transaction->t_iobuf_list; 1450470decc6SDave Kleikamp break; 1451470decc6SDave Kleikamp case BJ_Shadow: 1452470decc6SDave Kleikamp list = &transaction->t_shadow_list; 1453470decc6SDave Kleikamp break; 1454470decc6SDave Kleikamp case BJ_LogCtl: 1455470decc6SDave Kleikamp list = &transaction->t_log_list; 1456470decc6SDave Kleikamp break; 1457470decc6SDave Kleikamp case BJ_Reserved: 1458470decc6SDave Kleikamp list = &transaction->t_reserved_list; 1459470decc6SDave Kleikamp break; 1460470decc6SDave Kleikamp } 1461470decc6SDave Kleikamp 1462470decc6SDave Kleikamp __blist_del_buffer(list, jh); 1463470decc6SDave Kleikamp jh->b_jlist = BJ_None; 1464470decc6SDave Kleikamp if (test_clear_buffer_jbddirty(bh)) 1465470decc6SDave Kleikamp mark_buffer_dirty(bh); /* Expose it to the VM */ 1466470decc6SDave Kleikamp } 1467470decc6SDave Kleikamp 1468f7f4bccbSMingming Cao void __jbd2_journal_unfile_buffer(struct journal_head *jh) 1469470decc6SDave Kleikamp { 1470f7f4bccbSMingming Cao __jbd2_journal_temp_unlink_buffer(jh); 1471470decc6SDave Kleikamp jh->b_transaction = NULL; 1472470decc6SDave Kleikamp } 1473470decc6SDave Kleikamp 1474f7f4bccbSMingming Cao void jbd2_journal_unfile_buffer(journal_t *journal, struct journal_head *jh) 1475470decc6SDave Kleikamp { 1476470decc6SDave Kleikamp jbd_lock_bh_state(jh2bh(jh)); 1477470decc6SDave Kleikamp spin_lock(&journal->j_list_lock); 1478f7f4bccbSMingming Cao __jbd2_journal_unfile_buffer(jh); 1479470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 1480470decc6SDave Kleikamp jbd_unlock_bh_state(jh2bh(jh)); 1481470decc6SDave Kleikamp } 1482470decc6SDave Kleikamp 1483470decc6SDave Kleikamp /* 1484f7f4bccbSMingming Cao * Called from jbd2_journal_try_to_free_buffers(). 1485470decc6SDave Kleikamp * 1486470decc6SDave Kleikamp * Called under jbd_lock_bh_state(bh) 1487470decc6SDave Kleikamp */ 1488470decc6SDave Kleikamp static void 1489470decc6SDave Kleikamp __journal_try_to_free_buffer(journal_t *journal, struct buffer_head *bh) 1490470decc6SDave Kleikamp { 1491470decc6SDave Kleikamp struct journal_head *jh; 1492470decc6SDave Kleikamp 1493470decc6SDave Kleikamp jh = bh2jh(bh); 1494470decc6SDave Kleikamp 1495470decc6SDave Kleikamp if (buffer_locked(bh) || buffer_dirty(bh)) 1496470decc6SDave Kleikamp goto out; 1497470decc6SDave Kleikamp 14984019191bSMingming Cao if (jh->b_next_transaction != NULL) 1499470decc6SDave Kleikamp goto out; 1500470decc6SDave Kleikamp 1501470decc6SDave Kleikamp spin_lock(&journal->j_list_lock); 150287c89c23SJan Kara if (jh->b_cp_transaction != NULL && jh->b_transaction == NULL) { 1503470decc6SDave Kleikamp /* written-back checkpointed metadata buffer */ 1504470decc6SDave Kleikamp if (jh->b_jlist == BJ_None) { 1505470decc6SDave Kleikamp JBUFFER_TRACE(jh, "remove from checkpoint list"); 1506f7f4bccbSMingming Cao __jbd2_journal_remove_checkpoint(jh); 1507f7f4bccbSMingming Cao jbd2_journal_remove_journal_head(bh); 1508470decc6SDave Kleikamp __brelse(bh); 1509470decc6SDave Kleikamp } 1510470decc6SDave Kleikamp } 1511470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 1512470decc6SDave Kleikamp out: 1513470decc6SDave Kleikamp return; 1514470decc6SDave Kleikamp } 1515470decc6SDave Kleikamp 1516530576bbSMingming Cao /* 1517530576bbSMingming Cao * jbd2_journal_try_to_free_buffers() could race with 1518530576bbSMingming Cao * jbd2_journal_commit_transaction(). The later might still hold the 1519530576bbSMingming Cao * reference count to the buffers when inspecting them on 1520530576bbSMingming Cao * t_syncdata_list or t_locked_list. 1521530576bbSMingming Cao * 1522530576bbSMingming Cao * jbd2_journal_try_to_free_buffers() will call this function to 1523530576bbSMingming Cao * wait for the current transaction to finish syncing data buffers, before 1524530576bbSMingming Cao * try to free that buffer. 1525530576bbSMingming Cao * 1526530576bbSMingming Cao * Called with journal->j_state_lock hold. 1527530576bbSMingming Cao */ 1528530576bbSMingming Cao static void jbd2_journal_wait_for_transaction_sync_data(journal_t *journal) 1529530576bbSMingming Cao { 1530530576bbSMingming Cao transaction_t *transaction; 1531530576bbSMingming Cao tid_t tid; 1532530576bbSMingming Cao 1533530576bbSMingming Cao spin_lock(&journal->j_state_lock); 1534530576bbSMingming Cao transaction = journal->j_committing_transaction; 1535530576bbSMingming Cao 1536530576bbSMingming Cao if (!transaction) { 1537530576bbSMingming Cao spin_unlock(&journal->j_state_lock); 1538530576bbSMingming Cao return; 1539530576bbSMingming Cao } 1540530576bbSMingming Cao 1541530576bbSMingming Cao tid = transaction->t_tid; 1542530576bbSMingming Cao spin_unlock(&journal->j_state_lock); 1543530576bbSMingming Cao jbd2_log_wait_commit(journal, tid); 1544530576bbSMingming Cao } 1545470decc6SDave Kleikamp 1546470decc6SDave Kleikamp /** 1547f7f4bccbSMingming Cao * int jbd2_journal_try_to_free_buffers() - try to free page buffers. 1548470decc6SDave Kleikamp * @journal: journal for operation 1549470decc6SDave Kleikamp * @page: to try and free 1550530576bbSMingming Cao * @gfp_mask: we use the mask to detect how hard should we try to release 1551530576bbSMingming Cao * buffers. If __GFP_WAIT and __GFP_FS is set, we wait for commit code to 1552530576bbSMingming Cao * release the buffers. 1553470decc6SDave Kleikamp * 1554470decc6SDave Kleikamp * 1555470decc6SDave Kleikamp * For all the buffers on this page, 1556470decc6SDave Kleikamp * if they are fully written out ordered data, move them onto BUF_CLEAN 1557470decc6SDave Kleikamp * so try_to_free_buffers() can reap them. 1558470decc6SDave Kleikamp * 1559470decc6SDave Kleikamp * This function returns non-zero if we wish try_to_free_buffers() 1560470decc6SDave Kleikamp * to be called. We do this if the page is releasable by try_to_free_buffers(). 1561470decc6SDave Kleikamp * We also do it if the page has locked or dirty buffers and the caller wants 1562470decc6SDave Kleikamp * us to perform sync or async writeout. 1563470decc6SDave Kleikamp * 1564470decc6SDave Kleikamp * This complicates JBD locking somewhat. We aren't protected by the 1565470decc6SDave Kleikamp * BKL here. We wish to remove the buffer from its committing or 1566f7f4bccbSMingming Cao * running transaction's ->t_datalist via __jbd2_journal_unfile_buffer. 1567470decc6SDave Kleikamp * 1568470decc6SDave Kleikamp * This may *change* the value of transaction_t->t_datalist, so anyone 1569470decc6SDave Kleikamp * who looks at t_datalist needs to lock against this function. 1570470decc6SDave Kleikamp * 1571f7f4bccbSMingming Cao * Even worse, someone may be doing a jbd2_journal_dirty_data on this 1572f7f4bccbSMingming Cao * buffer. So we need to lock against that. jbd2_journal_dirty_data() 1573470decc6SDave Kleikamp * will come out of the lock with the buffer dirty, which makes it 1574470decc6SDave Kleikamp * ineligible for release here. 1575470decc6SDave Kleikamp * 1576470decc6SDave Kleikamp * Who else is affected by this? hmm... Really the only contender 1577470decc6SDave Kleikamp * is do_get_write_access() - it could be looking at the buffer while 1578470decc6SDave Kleikamp * journal_try_to_free_buffer() is changing its state. But that 1579470decc6SDave Kleikamp * cannot happen because we never reallocate freed data as metadata 1580470decc6SDave Kleikamp * while the data is part of a transaction. Yes? 1581530576bbSMingming Cao * 1582530576bbSMingming Cao * Return 0 on failure, 1 on success 1583470decc6SDave Kleikamp */ 1584f7f4bccbSMingming Cao int jbd2_journal_try_to_free_buffers(journal_t *journal, 1585530576bbSMingming Cao struct page *page, gfp_t gfp_mask) 1586470decc6SDave Kleikamp { 1587470decc6SDave Kleikamp struct buffer_head *head; 1588470decc6SDave Kleikamp struct buffer_head *bh; 1589470decc6SDave Kleikamp int ret = 0; 1590470decc6SDave Kleikamp 1591470decc6SDave Kleikamp J_ASSERT(PageLocked(page)); 1592470decc6SDave Kleikamp 1593470decc6SDave Kleikamp head = page_buffers(page); 1594470decc6SDave Kleikamp bh = head; 1595470decc6SDave Kleikamp do { 1596470decc6SDave Kleikamp struct journal_head *jh; 1597470decc6SDave Kleikamp 1598470decc6SDave Kleikamp /* 1599470decc6SDave Kleikamp * We take our own ref against the journal_head here to avoid 1600470decc6SDave Kleikamp * having to add tons of locking around each instance of 1601530576bbSMingming Cao * jbd2_journal_remove_journal_head() and 1602530576bbSMingming Cao * jbd2_journal_put_journal_head(). 1603470decc6SDave Kleikamp */ 1604f7f4bccbSMingming Cao jh = jbd2_journal_grab_journal_head(bh); 1605470decc6SDave Kleikamp if (!jh) 1606470decc6SDave Kleikamp continue; 1607470decc6SDave Kleikamp 1608470decc6SDave Kleikamp jbd_lock_bh_state(bh); 1609470decc6SDave Kleikamp __journal_try_to_free_buffer(journal, bh); 1610f7f4bccbSMingming Cao jbd2_journal_put_journal_head(jh); 1611470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 1612470decc6SDave Kleikamp if (buffer_jbd(bh)) 1613470decc6SDave Kleikamp goto busy; 1614470decc6SDave Kleikamp } while ((bh = bh->b_this_page) != head); 1615530576bbSMingming Cao 1616470decc6SDave Kleikamp ret = try_to_free_buffers(page); 1617530576bbSMingming Cao 1618530576bbSMingming Cao /* 1619530576bbSMingming Cao * There are a number of places where jbd2_journal_try_to_free_buffers() 1620530576bbSMingming Cao * could race with jbd2_journal_commit_transaction(), the later still 1621530576bbSMingming Cao * holds the reference to the buffers to free while processing them. 1622530576bbSMingming Cao * try_to_free_buffers() failed to free those buffers. Some of the 1623530576bbSMingming Cao * caller of releasepage() request page buffers to be dropped, otherwise 1624530576bbSMingming Cao * treat the fail-to-free as errors (such as generic_file_direct_IO()) 1625530576bbSMingming Cao * 1626530576bbSMingming Cao * So, if the caller of try_to_release_page() wants the synchronous 1627530576bbSMingming Cao * behaviour(i.e make sure buffers are dropped upon return), 1628530576bbSMingming Cao * let's wait for the current transaction to finish flush of 1629530576bbSMingming Cao * dirty data buffers, then try to free those buffers again, 1630530576bbSMingming Cao * with the journal locked. 1631530576bbSMingming Cao */ 1632530576bbSMingming Cao if (ret == 0 && (gfp_mask & __GFP_WAIT) && (gfp_mask & __GFP_FS)) { 1633530576bbSMingming Cao jbd2_journal_wait_for_transaction_sync_data(journal); 1634530576bbSMingming Cao ret = try_to_free_buffers(page); 1635530576bbSMingming Cao } 1636530576bbSMingming Cao 1637470decc6SDave Kleikamp busy: 1638470decc6SDave Kleikamp return ret; 1639470decc6SDave Kleikamp } 1640470decc6SDave Kleikamp 1641470decc6SDave Kleikamp /* 1642470decc6SDave Kleikamp * This buffer is no longer needed. If it is on an older transaction's 1643470decc6SDave Kleikamp * checkpoint list we need to record it on this transaction's forget list 1644470decc6SDave Kleikamp * to pin this buffer (and hence its checkpointing transaction) down until 1645470decc6SDave Kleikamp * this transaction commits. If the buffer isn't on a checkpoint list, we 1646470decc6SDave Kleikamp * release it. 1647470decc6SDave Kleikamp * Returns non-zero if JBD no longer has an interest in the buffer. 1648470decc6SDave Kleikamp * 1649470decc6SDave Kleikamp * Called under j_list_lock. 1650470decc6SDave Kleikamp * 1651470decc6SDave Kleikamp * Called under jbd_lock_bh_state(bh). 1652470decc6SDave Kleikamp */ 1653470decc6SDave Kleikamp static int __dispose_buffer(struct journal_head *jh, transaction_t *transaction) 1654470decc6SDave Kleikamp { 1655470decc6SDave Kleikamp int may_free = 1; 1656470decc6SDave Kleikamp struct buffer_head *bh = jh2bh(jh); 1657470decc6SDave Kleikamp 1658f7f4bccbSMingming Cao __jbd2_journal_unfile_buffer(jh); 1659470decc6SDave Kleikamp 1660470decc6SDave Kleikamp if (jh->b_cp_transaction) { 1661470decc6SDave Kleikamp JBUFFER_TRACE(jh, "on running+cp transaction"); 1662f7f4bccbSMingming Cao __jbd2_journal_file_buffer(jh, transaction, BJ_Forget); 1663470decc6SDave Kleikamp clear_buffer_jbddirty(bh); 1664470decc6SDave Kleikamp may_free = 0; 1665470decc6SDave Kleikamp } else { 1666470decc6SDave Kleikamp JBUFFER_TRACE(jh, "on running transaction"); 1667f7f4bccbSMingming Cao jbd2_journal_remove_journal_head(bh); 1668470decc6SDave Kleikamp __brelse(bh); 1669470decc6SDave Kleikamp } 1670470decc6SDave Kleikamp return may_free; 1671470decc6SDave Kleikamp } 1672470decc6SDave Kleikamp 1673470decc6SDave Kleikamp /* 1674f7f4bccbSMingming Cao * jbd2_journal_invalidatepage 1675470decc6SDave Kleikamp * 1676470decc6SDave Kleikamp * This code is tricky. It has a number of cases to deal with. 1677470decc6SDave Kleikamp * 1678470decc6SDave Kleikamp * There are two invariants which this code relies on: 1679470decc6SDave Kleikamp * 1680470decc6SDave Kleikamp * i_size must be updated on disk before we start calling invalidatepage on the 1681470decc6SDave Kleikamp * data. 1682470decc6SDave Kleikamp * 1683470decc6SDave Kleikamp * This is done in ext3 by defining an ext3_setattr method which 1684470decc6SDave Kleikamp * updates i_size before truncate gets going. By maintaining this 1685470decc6SDave Kleikamp * invariant, we can be sure that it is safe to throw away any buffers 1686470decc6SDave Kleikamp * attached to the current transaction: once the transaction commits, 1687470decc6SDave Kleikamp * we know that the data will not be needed. 1688470decc6SDave Kleikamp * 1689470decc6SDave Kleikamp * Note however that we can *not* throw away data belonging to the 1690470decc6SDave Kleikamp * previous, committing transaction! 1691470decc6SDave Kleikamp * 1692470decc6SDave Kleikamp * Any disk blocks which *are* part of the previous, committing 1693470decc6SDave Kleikamp * transaction (and which therefore cannot be discarded immediately) are 1694470decc6SDave Kleikamp * not going to be reused in the new running transaction 1695470decc6SDave Kleikamp * 1696470decc6SDave Kleikamp * The bitmap committed_data images guarantee this: any block which is 1697470decc6SDave Kleikamp * allocated in one transaction and removed in the next will be marked 1698470decc6SDave Kleikamp * as in-use in the committed_data bitmap, so cannot be reused until 1699470decc6SDave Kleikamp * the next transaction to delete the block commits. This means that 1700470decc6SDave Kleikamp * leaving committing buffers dirty is quite safe: the disk blocks 1701470decc6SDave Kleikamp * cannot be reallocated to a different file and so buffer aliasing is 1702470decc6SDave Kleikamp * not possible. 1703470decc6SDave Kleikamp * 1704470decc6SDave Kleikamp * 1705470decc6SDave Kleikamp * The above applies mainly to ordered data mode. In writeback mode we 1706470decc6SDave Kleikamp * don't make guarantees about the order in which data hits disk --- in 1707470decc6SDave Kleikamp * particular we don't guarantee that new dirty data is flushed before 1708470decc6SDave Kleikamp * transaction commit --- so it is always safe just to discard data 1709470decc6SDave Kleikamp * immediately in that mode. --sct 1710470decc6SDave Kleikamp */ 1711470decc6SDave Kleikamp 1712470decc6SDave Kleikamp /* 1713470decc6SDave Kleikamp * The journal_unmap_buffer helper function returns zero if the buffer 1714470decc6SDave Kleikamp * concerned remains pinned as an anonymous buffer belonging to an older 1715470decc6SDave Kleikamp * transaction. 1716470decc6SDave Kleikamp * 1717470decc6SDave Kleikamp * We're outside-transaction here. Either or both of j_running_transaction 1718470decc6SDave Kleikamp * and j_committing_transaction may be NULL. 1719470decc6SDave Kleikamp */ 1720470decc6SDave Kleikamp static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh) 1721470decc6SDave Kleikamp { 1722470decc6SDave Kleikamp transaction_t *transaction; 1723470decc6SDave Kleikamp struct journal_head *jh; 1724470decc6SDave Kleikamp int may_free = 1; 1725470decc6SDave Kleikamp int ret; 1726470decc6SDave Kleikamp 1727470decc6SDave Kleikamp BUFFER_TRACE(bh, "entry"); 1728470decc6SDave Kleikamp 1729470decc6SDave Kleikamp /* 1730470decc6SDave Kleikamp * It is safe to proceed here without the j_list_lock because the 1731470decc6SDave Kleikamp * buffers cannot be stolen by try_to_free_buffers as long as we are 1732470decc6SDave Kleikamp * holding the page lock. --sct 1733470decc6SDave Kleikamp */ 1734470decc6SDave Kleikamp 1735470decc6SDave Kleikamp if (!buffer_jbd(bh)) 1736470decc6SDave Kleikamp goto zap_buffer_unlocked; 1737470decc6SDave Kleikamp 173887c89c23SJan Kara /* OK, we have data buffer in journaled mode */ 1739470decc6SDave Kleikamp spin_lock(&journal->j_state_lock); 1740470decc6SDave Kleikamp jbd_lock_bh_state(bh); 1741470decc6SDave Kleikamp spin_lock(&journal->j_list_lock); 1742470decc6SDave Kleikamp 1743f7f4bccbSMingming Cao jh = jbd2_journal_grab_journal_head(bh); 1744470decc6SDave Kleikamp if (!jh) 1745470decc6SDave Kleikamp goto zap_buffer_no_jh; 1746470decc6SDave Kleikamp 1747470decc6SDave Kleikamp transaction = jh->b_transaction; 1748470decc6SDave Kleikamp if (transaction == NULL) { 1749470decc6SDave Kleikamp /* First case: not on any transaction. If it 1750470decc6SDave Kleikamp * has no checkpoint link, then we can zap it: 1751470decc6SDave Kleikamp * it's a writeback-mode buffer so we don't care 1752470decc6SDave Kleikamp * if it hits disk safely. */ 1753470decc6SDave Kleikamp if (!jh->b_cp_transaction) { 1754470decc6SDave Kleikamp JBUFFER_TRACE(jh, "not on any transaction: zap"); 1755470decc6SDave Kleikamp goto zap_buffer; 1756470decc6SDave Kleikamp } 1757470decc6SDave Kleikamp 1758470decc6SDave Kleikamp if (!buffer_dirty(bh)) { 1759470decc6SDave Kleikamp /* bdflush has written it. We can drop it now */ 1760470decc6SDave Kleikamp goto zap_buffer; 1761470decc6SDave Kleikamp } 1762470decc6SDave Kleikamp 1763470decc6SDave Kleikamp /* OK, it must be in the journal but still not 1764470decc6SDave Kleikamp * written fully to disk: it's metadata or 1765470decc6SDave Kleikamp * journaled data... */ 1766470decc6SDave Kleikamp 1767470decc6SDave Kleikamp if (journal->j_running_transaction) { 1768470decc6SDave Kleikamp /* ... and once the current transaction has 1769470decc6SDave Kleikamp * committed, the buffer won't be needed any 1770470decc6SDave Kleikamp * longer. */ 1771470decc6SDave Kleikamp JBUFFER_TRACE(jh, "checkpointed: add to BJ_Forget"); 1772470decc6SDave Kleikamp ret = __dispose_buffer(jh, 1773470decc6SDave Kleikamp journal->j_running_transaction); 1774f7f4bccbSMingming Cao jbd2_journal_put_journal_head(jh); 1775470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 1776470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 1777470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 1778470decc6SDave Kleikamp return ret; 1779470decc6SDave Kleikamp } else { 1780470decc6SDave Kleikamp /* There is no currently-running transaction. So the 1781470decc6SDave Kleikamp * orphan record which we wrote for this file must have 1782470decc6SDave Kleikamp * passed into commit. We must attach this buffer to 1783470decc6SDave Kleikamp * the committing transaction, if it exists. */ 1784470decc6SDave Kleikamp if (journal->j_committing_transaction) { 1785470decc6SDave Kleikamp JBUFFER_TRACE(jh, "give to committing trans"); 1786470decc6SDave Kleikamp ret = __dispose_buffer(jh, 1787470decc6SDave Kleikamp journal->j_committing_transaction); 1788f7f4bccbSMingming Cao jbd2_journal_put_journal_head(jh); 1789470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 1790470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 1791470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 1792470decc6SDave Kleikamp return ret; 1793470decc6SDave Kleikamp } else { 1794470decc6SDave Kleikamp /* The orphan record's transaction has 1795470decc6SDave Kleikamp * committed. We can cleanse this buffer */ 1796470decc6SDave Kleikamp clear_buffer_jbddirty(bh); 1797470decc6SDave Kleikamp goto zap_buffer; 1798470decc6SDave Kleikamp } 1799470decc6SDave Kleikamp } 1800470decc6SDave Kleikamp } else if (transaction == journal->j_committing_transaction) { 18019b57988dSEric Sandeen JBUFFER_TRACE(jh, "on committing transaction"); 1802470decc6SDave Kleikamp /* 1803470decc6SDave Kleikamp * If it is committing, we simply cannot touch it. We 1804470decc6SDave Kleikamp * can remove it's next_transaction pointer from the 1805470decc6SDave Kleikamp * running transaction if that is set, but nothing 1806470decc6SDave Kleikamp * else. */ 1807470decc6SDave Kleikamp set_buffer_freed(bh); 1808470decc6SDave Kleikamp if (jh->b_next_transaction) { 1809470decc6SDave Kleikamp J_ASSERT(jh->b_next_transaction == 1810470decc6SDave Kleikamp journal->j_running_transaction); 1811470decc6SDave Kleikamp jh->b_next_transaction = NULL; 1812470decc6SDave Kleikamp } 1813f7f4bccbSMingming Cao jbd2_journal_put_journal_head(jh); 1814470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 1815470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 1816470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 1817470decc6SDave Kleikamp return 0; 1818470decc6SDave Kleikamp } else { 1819470decc6SDave Kleikamp /* Good, the buffer belongs to the running transaction. 1820470decc6SDave Kleikamp * We are writing our own transaction's data, not any 1821470decc6SDave Kleikamp * previous one's, so it is safe to throw it away 1822470decc6SDave Kleikamp * (remember that we expect the filesystem to have set 1823470decc6SDave Kleikamp * i_size already for this truncate so recovery will not 1824470decc6SDave Kleikamp * expose the disk blocks we are discarding here.) */ 1825470decc6SDave Kleikamp J_ASSERT_JH(jh, transaction == journal->j_running_transaction); 18269b57988dSEric Sandeen JBUFFER_TRACE(jh, "on running transaction"); 1827470decc6SDave Kleikamp may_free = __dispose_buffer(jh, transaction); 1828470decc6SDave Kleikamp } 1829470decc6SDave Kleikamp 1830470decc6SDave Kleikamp zap_buffer: 1831f7f4bccbSMingming Cao jbd2_journal_put_journal_head(jh); 1832470decc6SDave Kleikamp zap_buffer_no_jh: 1833470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 1834470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 1835470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 1836470decc6SDave Kleikamp zap_buffer_unlocked: 1837470decc6SDave Kleikamp clear_buffer_dirty(bh); 1838470decc6SDave Kleikamp J_ASSERT_BH(bh, !buffer_jbddirty(bh)); 1839470decc6SDave Kleikamp clear_buffer_mapped(bh); 1840470decc6SDave Kleikamp clear_buffer_req(bh); 1841470decc6SDave Kleikamp clear_buffer_new(bh); 1842470decc6SDave Kleikamp bh->b_bdev = NULL; 1843470decc6SDave Kleikamp return may_free; 1844470decc6SDave Kleikamp } 1845470decc6SDave Kleikamp 1846470decc6SDave Kleikamp /** 1847f7f4bccbSMingming Cao * void jbd2_journal_invalidatepage() 1848470decc6SDave Kleikamp * @journal: journal to use for flush... 1849470decc6SDave Kleikamp * @page: page to flush 1850470decc6SDave Kleikamp * @offset: length of page to invalidate. 1851470decc6SDave Kleikamp * 1852470decc6SDave Kleikamp * Reap page buffers containing data after offset in page. 1853470decc6SDave Kleikamp * 1854470decc6SDave Kleikamp */ 1855f7f4bccbSMingming Cao void jbd2_journal_invalidatepage(journal_t *journal, 1856470decc6SDave Kleikamp struct page *page, 1857470decc6SDave Kleikamp unsigned long offset) 1858470decc6SDave Kleikamp { 1859470decc6SDave Kleikamp struct buffer_head *head, *bh, *next; 1860470decc6SDave Kleikamp unsigned int curr_off = 0; 1861470decc6SDave Kleikamp int may_free = 1; 1862470decc6SDave Kleikamp 1863470decc6SDave Kleikamp if (!PageLocked(page)) 1864470decc6SDave Kleikamp BUG(); 1865470decc6SDave Kleikamp if (!page_has_buffers(page)) 1866470decc6SDave Kleikamp return; 1867470decc6SDave Kleikamp 1868470decc6SDave Kleikamp /* We will potentially be playing with lists other than just the 1869470decc6SDave Kleikamp * data lists (especially for journaled data mode), so be 1870470decc6SDave Kleikamp * cautious in our locking. */ 1871470decc6SDave Kleikamp 1872470decc6SDave Kleikamp head = bh = page_buffers(page); 1873470decc6SDave Kleikamp do { 1874470decc6SDave Kleikamp unsigned int next_off = curr_off + bh->b_size; 1875470decc6SDave Kleikamp next = bh->b_this_page; 1876470decc6SDave Kleikamp 1877470decc6SDave Kleikamp if (offset <= curr_off) { 1878470decc6SDave Kleikamp /* This block is wholly outside the truncation point */ 1879470decc6SDave Kleikamp lock_buffer(bh); 1880470decc6SDave Kleikamp may_free &= journal_unmap_buffer(journal, bh); 1881470decc6SDave Kleikamp unlock_buffer(bh); 1882470decc6SDave Kleikamp } 1883470decc6SDave Kleikamp curr_off = next_off; 1884470decc6SDave Kleikamp bh = next; 1885470decc6SDave Kleikamp 1886470decc6SDave Kleikamp } while (bh != head); 1887470decc6SDave Kleikamp 1888470decc6SDave Kleikamp if (!offset) { 1889470decc6SDave Kleikamp if (may_free && try_to_free_buffers(page)) 1890470decc6SDave Kleikamp J_ASSERT(!page_has_buffers(page)); 1891470decc6SDave Kleikamp } 1892470decc6SDave Kleikamp } 1893470decc6SDave Kleikamp 1894470decc6SDave Kleikamp /* 1895470decc6SDave Kleikamp * File a buffer on the given transaction list. 1896470decc6SDave Kleikamp */ 1897f7f4bccbSMingming Cao void __jbd2_journal_file_buffer(struct journal_head *jh, 1898470decc6SDave Kleikamp transaction_t *transaction, int jlist) 1899470decc6SDave Kleikamp { 1900470decc6SDave Kleikamp struct journal_head **list = NULL; 1901470decc6SDave Kleikamp int was_dirty = 0; 1902470decc6SDave Kleikamp struct buffer_head *bh = jh2bh(jh); 1903470decc6SDave Kleikamp 1904470decc6SDave Kleikamp J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh)); 1905470decc6SDave Kleikamp assert_spin_locked(&transaction->t_journal->j_list_lock); 1906470decc6SDave Kleikamp 1907470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_jlist < BJ_Types); 1908470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_transaction == transaction || 19094019191bSMingming Cao jh->b_transaction == NULL); 1910470decc6SDave Kleikamp 1911470decc6SDave Kleikamp if (jh->b_transaction && jh->b_jlist == jlist) 1912470decc6SDave Kleikamp return; 1913470decc6SDave Kleikamp 1914470decc6SDave Kleikamp /* The following list of buffer states needs to be consistent 1915470decc6SDave Kleikamp * with __jbd_unexpected_dirty_buffer()'s handling of dirty 1916470decc6SDave Kleikamp * state. */ 1917470decc6SDave Kleikamp 1918470decc6SDave Kleikamp if (jlist == BJ_Metadata || jlist == BJ_Reserved || 1919470decc6SDave Kleikamp jlist == BJ_Shadow || jlist == BJ_Forget) { 1920470decc6SDave Kleikamp if (test_clear_buffer_dirty(bh) || 1921470decc6SDave Kleikamp test_clear_buffer_jbddirty(bh)) 1922470decc6SDave Kleikamp was_dirty = 1; 1923470decc6SDave Kleikamp } 1924470decc6SDave Kleikamp 1925470decc6SDave Kleikamp if (jh->b_transaction) 1926f7f4bccbSMingming Cao __jbd2_journal_temp_unlink_buffer(jh); 1927470decc6SDave Kleikamp jh->b_transaction = transaction; 1928470decc6SDave Kleikamp 1929470decc6SDave Kleikamp switch (jlist) { 1930470decc6SDave Kleikamp case BJ_None: 1931470decc6SDave Kleikamp J_ASSERT_JH(jh, !jh->b_committed_data); 1932470decc6SDave Kleikamp J_ASSERT_JH(jh, !jh->b_frozen_data); 1933470decc6SDave Kleikamp return; 1934470decc6SDave Kleikamp case BJ_Metadata: 1935470decc6SDave Kleikamp transaction->t_nr_buffers++; 1936470decc6SDave Kleikamp list = &transaction->t_buffers; 1937470decc6SDave Kleikamp break; 1938470decc6SDave Kleikamp case BJ_Forget: 1939470decc6SDave Kleikamp list = &transaction->t_forget; 1940470decc6SDave Kleikamp break; 1941470decc6SDave Kleikamp case BJ_IO: 1942470decc6SDave Kleikamp list = &transaction->t_iobuf_list; 1943470decc6SDave Kleikamp break; 1944470decc6SDave Kleikamp case BJ_Shadow: 1945470decc6SDave Kleikamp list = &transaction->t_shadow_list; 1946470decc6SDave Kleikamp break; 1947470decc6SDave Kleikamp case BJ_LogCtl: 1948470decc6SDave Kleikamp list = &transaction->t_log_list; 1949470decc6SDave Kleikamp break; 1950470decc6SDave Kleikamp case BJ_Reserved: 1951470decc6SDave Kleikamp list = &transaction->t_reserved_list; 1952470decc6SDave Kleikamp break; 1953470decc6SDave Kleikamp } 1954470decc6SDave Kleikamp 1955470decc6SDave Kleikamp __blist_add_buffer(list, jh); 1956470decc6SDave Kleikamp jh->b_jlist = jlist; 1957470decc6SDave Kleikamp 1958470decc6SDave Kleikamp if (was_dirty) 1959470decc6SDave Kleikamp set_buffer_jbddirty(bh); 1960470decc6SDave Kleikamp } 1961470decc6SDave Kleikamp 1962f7f4bccbSMingming Cao void jbd2_journal_file_buffer(struct journal_head *jh, 1963470decc6SDave Kleikamp transaction_t *transaction, int jlist) 1964470decc6SDave Kleikamp { 1965470decc6SDave Kleikamp jbd_lock_bh_state(jh2bh(jh)); 1966470decc6SDave Kleikamp spin_lock(&transaction->t_journal->j_list_lock); 1967f7f4bccbSMingming Cao __jbd2_journal_file_buffer(jh, transaction, jlist); 1968470decc6SDave Kleikamp spin_unlock(&transaction->t_journal->j_list_lock); 1969470decc6SDave Kleikamp jbd_unlock_bh_state(jh2bh(jh)); 1970470decc6SDave Kleikamp } 1971470decc6SDave Kleikamp 1972470decc6SDave Kleikamp /* 1973470decc6SDave Kleikamp * Remove a buffer from its current buffer list in preparation for 1974470decc6SDave Kleikamp * dropping it from its current transaction entirely. If the buffer has 1975470decc6SDave Kleikamp * already started to be used by a subsequent transaction, refile the 1976470decc6SDave Kleikamp * buffer on that transaction's metadata list. 1977470decc6SDave Kleikamp * 1978470decc6SDave Kleikamp * Called under journal->j_list_lock 1979470decc6SDave Kleikamp * 1980470decc6SDave Kleikamp * Called under jbd_lock_bh_state(jh2bh(jh)) 1981470decc6SDave Kleikamp */ 1982f7f4bccbSMingming Cao void __jbd2_journal_refile_buffer(struct journal_head *jh) 1983470decc6SDave Kleikamp { 1984470decc6SDave Kleikamp int was_dirty; 1985470decc6SDave Kleikamp struct buffer_head *bh = jh2bh(jh); 1986470decc6SDave Kleikamp 1987470decc6SDave Kleikamp J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh)); 1988470decc6SDave Kleikamp if (jh->b_transaction) 1989470decc6SDave Kleikamp assert_spin_locked(&jh->b_transaction->t_journal->j_list_lock); 1990470decc6SDave Kleikamp 1991470decc6SDave Kleikamp /* If the buffer is now unused, just drop it. */ 1992470decc6SDave Kleikamp if (jh->b_next_transaction == NULL) { 1993f7f4bccbSMingming Cao __jbd2_journal_unfile_buffer(jh); 1994470decc6SDave Kleikamp return; 1995470decc6SDave Kleikamp } 1996470decc6SDave Kleikamp 1997470decc6SDave Kleikamp /* 1998470decc6SDave Kleikamp * It has been modified by a later transaction: add it to the new 1999470decc6SDave Kleikamp * transaction's metadata list. 2000470decc6SDave Kleikamp */ 2001470decc6SDave Kleikamp 2002470decc6SDave Kleikamp was_dirty = test_clear_buffer_jbddirty(bh); 2003f7f4bccbSMingming Cao __jbd2_journal_temp_unlink_buffer(jh); 2004470decc6SDave Kleikamp jh->b_transaction = jh->b_next_transaction; 2005470decc6SDave Kleikamp jh->b_next_transaction = NULL; 2006f7f4bccbSMingming Cao __jbd2_journal_file_buffer(jh, jh->b_transaction, 20071dfc3220SJosef Bacik jh->b_modified ? BJ_Metadata : BJ_Reserved); 2008470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_transaction->t_state == T_RUNNING); 2009470decc6SDave Kleikamp 2010470decc6SDave Kleikamp if (was_dirty) 2011470decc6SDave Kleikamp set_buffer_jbddirty(bh); 2012470decc6SDave Kleikamp } 2013470decc6SDave Kleikamp 2014470decc6SDave Kleikamp /* 2015470decc6SDave Kleikamp * For the unlocked version of this call, also make sure that any 2016470decc6SDave Kleikamp * hanging journal_head is cleaned up if necessary. 2017470decc6SDave Kleikamp * 2018f7f4bccbSMingming Cao * __jbd2_journal_refile_buffer is usually called as part of a single locked 2019470decc6SDave Kleikamp * operation on a buffer_head, in which the caller is probably going to 2020470decc6SDave Kleikamp * be hooking the journal_head onto other lists. In that case it is up 2021470decc6SDave Kleikamp * to the caller to remove the journal_head if necessary. For the 2022f7f4bccbSMingming Cao * unlocked jbd2_journal_refile_buffer call, the caller isn't going to be 2023470decc6SDave Kleikamp * doing anything else to the buffer so we need to do the cleanup 2024470decc6SDave Kleikamp * ourselves to avoid a jh leak. 2025470decc6SDave Kleikamp * 2026470decc6SDave Kleikamp * *** The journal_head may be freed by this call! *** 2027470decc6SDave Kleikamp */ 2028f7f4bccbSMingming Cao void jbd2_journal_refile_buffer(journal_t *journal, struct journal_head *jh) 2029470decc6SDave Kleikamp { 2030470decc6SDave Kleikamp struct buffer_head *bh = jh2bh(jh); 2031470decc6SDave Kleikamp 2032470decc6SDave Kleikamp jbd_lock_bh_state(bh); 2033470decc6SDave Kleikamp spin_lock(&journal->j_list_lock); 2034470decc6SDave Kleikamp 2035f7f4bccbSMingming Cao __jbd2_journal_refile_buffer(jh); 2036470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 2037f7f4bccbSMingming Cao jbd2_journal_remove_journal_head(bh); 2038470decc6SDave Kleikamp 2039470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 2040470decc6SDave Kleikamp __brelse(bh); 2041470decc6SDave Kleikamp } 2042c851ed54SJan Kara 2043c851ed54SJan Kara /* 2044c851ed54SJan Kara * File inode in the inode list of the handle's transaction 2045c851ed54SJan Kara */ 2046c851ed54SJan Kara int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *jinode) 2047c851ed54SJan Kara { 2048c851ed54SJan Kara transaction_t *transaction = handle->h_transaction; 2049c851ed54SJan Kara journal_t *journal = transaction->t_journal; 2050c851ed54SJan Kara 2051c851ed54SJan Kara if (is_handle_aborted(handle)) 2052c851ed54SJan Kara return -EIO; 2053c851ed54SJan Kara 2054c851ed54SJan Kara jbd_debug(4, "Adding inode %lu, tid:%d\n", jinode->i_vfs_inode->i_ino, 2055c851ed54SJan Kara transaction->t_tid); 2056c851ed54SJan Kara 2057c851ed54SJan Kara /* 2058c851ed54SJan Kara * First check whether inode isn't already on the transaction's 2059c851ed54SJan Kara * lists without taking the lock. Note that this check is safe 2060c851ed54SJan Kara * without the lock as we cannot race with somebody removing inode 2061c851ed54SJan Kara * from the transaction. The reason is that we remove inode from the 2062c851ed54SJan Kara * transaction only in journal_release_jbd_inode() and when we commit 2063c851ed54SJan Kara * the transaction. We are guarded from the first case by holding 2064c851ed54SJan Kara * a reference to the inode. We are safe against the second case 2065c851ed54SJan Kara * because if jinode->i_transaction == transaction, commit code 2066c851ed54SJan Kara * cannot touch the transaction because we hold reference to it, 2067c851ed54SJan Kara * and if jinode->i_next_transaction == transaction, commit code 2068c851ed54SJan Kara * will only file the inode where we want it. 2069c851ed54SJan Kara */ 2070c851ed54SJan Kara if (jinode->i_transaction == transaction || 2071c851ed54SJan Kara jinode->i_next_transaction == transaction) 2072c851ed54SJan Kara return 0; 2073c851ed54SJan Kara 2074c851ed54SJan Kara spin_lock(&journal->j_list_lock); 2075c851ed54SJan Kara 2076c851ed54SJan Kara if (jinode->i_transaction == transaction || 2077c851ed54SJan Kara jinode->i_next_transaction == transaction) 2078c851ed54SJan Kara goto done; 2079c851ed54SJan Kara 2080c851ed54SJan Kara /* On some different transaction's list - should be 2081c851ed54SJan Kara * the committing one */ 2082c851ed54SJan Kara if (jinode->i_transaction) { 2083c851ed54SJan Kara J_ASSERT(jinode->i_next_transaction == NULL); 2084c851ed54SJan Kara J_ASSERT(jinode->i_transaction == 2085c851ed54SJan Kara journal->j_committing_transaction); 2086c851ed54SJan Kara jinode->i_next_transaction = transaction; 2087c851ed54SJan Kara goto done; 2088c851ed54SJan Kara } 2089c851ed54SJan Kara /* Not on any transaction list... */ 2090c851ed54SJan Kara J_ASSERT(!jinode->i_next_transaction); 2091c851ed54SJan Kara jinode->i_transaction = transaction; 2092c851ed54SJan Kara list_add(&jinode->i_list, &transaction->t_inode_list); 2093c851ed54SJan Kara done: 2094c851ed54SJan Kara spin_unlock(&journal->j_list_lock); 2095c851ed54SJan Kara 2096c851ed54SJan Kara return 0; 2097c851ed54SJan Kara } 2098c851ed54SJan Kara 2099c851ed54SJan Kara /* 2100c851ed54SJan Kara * This function must be called when inode is journaled in ordered mode 2101c851ed54SJan Kara * before truncation happens. It starts writeout of truncated part in 2102c851ed54SJan Kara * case it is in the committing transaction so that we stand to ordered 2103c851ed54SJan Kara * mode consistency guarantees. 2104c851ed54SJan Kara */ 2105c851ed54SJan Kara int jbd2_journal_begin_ordered_truncate(struct jbd2_inode *inode, 2106c851ed54SJan Kara loff_t new_size) 2107c851ed54SJan Kara { 2108c851ed54SJan Kara journal_t *journal; 2109c851ed54SJan Kara transaction_t *commit_trans; 2110c851ed54SJan Kara int ret = 0; 2111c851ed54SJan Kara 2112c851ed54SJan Kara if (!inode->i_transaction && !inode->i_next_transaction) 2113c851ed54SJan Kara goto out; 2114c851ed54SJan Kara journal = inode->i_transaction->t_journal; 2115c851ed54SJan Kara spin_lock(&journal->j_state_lock); 2116c851ed54SJan Kara commit_trans = journal->j_committing_transaction; 2117c851ed54SJan Kara spin_unlock(&journal->j_state_lock); 2118c851ed54SJan Kara if (inode->i_transaction == commit_trans) { 2119c851ed54SJan Kara ret = filemap_fdatawrite_range(inode->i_vfs_inode->i_mapping, 2120c851ed54SJan Kara new_size, LLONG_MAX); 2121c851ed54SJan Kara if (ret) 2122c851ed54SJan Kara jbd2_journal_abort(journal, ret); 2123c851ed54SJan Kara } 2124c851ed54SJan Kara out: 2125c851ed54SJan Kara return ret; 2126c851ed54SJan Kara } 2127