1470decc6SDave Kleikamp /* 258862699SUwe Kleine-König * linux/fs/jbd2/transaction.c 3470decc6SDave Kleikamp * 4470decc6SDave Kleikamp * Written by Stephen C. Tweedie <sct@redhat.com>, 1998 5470decc6SDave Kleikamp * 6470decc6SDave Kleikamp * Copyright 1998 Red Hat corp --- All Rights Reserved 7470decc6SDave Kleikamp * 8470decc6SDave Kleikamp * This file is part of the Linux kernel and is made available under 9470decc6SDave Kleikamp * the terms of the GNU General Public License, version 2, or at your 10470decc6SDave Kleikamp * option, any later version, incorporated herein by reference. 11470decc6SDave Kleikamp * 12470decc6SDave Kleikamp * Generic filesystem transaction handling code; part of the ext2fs 13470decc6SDave Kleikamp * journaling system. 14470decc6SDave Kleikamp * 15470decc6SDave Kleikamp * This file manages transactions (compound commits managed by the 16470decc6SDave Kleikamp * journaling code) and handles (individual atomic operations by the 17470decc6SDave Kleikamp * filesystem). 18470decc6SDave Kleikamp */ 19470decc6SDave Kleikamp 20470decc6SDave Kleikamp #include <linux/time.h> 21470decc6SDave Kleikamp #include <linux/fs.h> 22f7f4bccbSMingming Cao #include <linux/jbd2.h> 23470decc6SDave Kleikamp #include <linux/errno.h> 24470decc6SDave Kleikamp #include <linux/slab.h> 25470decc6SDave Kleikamp #include <linux/timer.h> 26470decc6SDave Kleikamp #include <linux/mm.h> 27470decc6SDave Kleikamp #include <linux/highmem.h> 28e07f7183SJosef Bacik #include <linux/hrtimer.h> 29470decc6SDave Kleikamp 307ddae860SAdrian Bunk static void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh); 317ddae860SAdrian Bunk 32470decc6SDave Kleikamp /* 33f7f4bccbSMingming Cao * jbd2_get_transaction: obtain a new transaction_t object. 34470decc6SDave Kleikamp * 35470decc6SDave Kleikamp * Simply allocate and initialise a new transaction. Create it in 36470decc6SDave Kleikamp * RUNNING state and add it to the current journal (which should not 37470decc6SDave Kleikamp * have an existing running transaction: we only make a new transaction 38470decc6SDave Kleikamp * once we have started to commit the old one). 39470decc6SDave Kleikamp * 40470decc6SDave Kleikamp * Preconditions: 41470decc6SDave Kleikamp * The journal MUST be locked. We don't perform atomic mallocs on the 42470decc6SDave Kleikamp * new transaction and we can't block without protecting against other 43470decc6SDave Kleikamp * processes trying to touch the journal while it is in transition. 44470decc6SDave Kleikamp * 45470decc6SDave Kleikamp */ 46470decc6SDave Kleikamp 47470decc6SDave Kleikamp static transaction_t * 48f7f4bccbSMingming Cao jbd2_get_transaction(journal_t *journal, transaction_t *transaction) 49470decc6SDave Kleikamp { 50470decc6SDave Kleikamp transaction->t_journal = journal; 51470decc6SDave Kleikamp transaction->t_state = T_RUNNING; 52e07f7183SJosef Bacik transaction->t_start_time = ktime_get(); 53470decc6SDave Kleikamp transaction->t_tid = journal->j_transaction_sequence++; 54470decc6SDave Kleikamp transaction->t_expires = jiffies + journal->j_commit_interval; 55470decc6SDave Kleikamp spin_lock_init(&transaction->t_handle_lock); 56c851ed54SJan Kara INIT_LIST_HEAD(&transaction->t_inode_list); 573e624fc7STheodore Ts'o INIT_LIST_HEAD(&transaction->t_private_list); 58470decc6SDave Kleikamp 59470decc6SDave Kleikamp /* Set up the commit timer for the new transaction. */ 60b1f485f2SAndreas Dilger journal->j_commit_timer.expires = round_jiffies_up(transaction->t_expires); 61470decc6SDave Kleikamp add_timer(&journal->j_commit_timer); 62470decc6SDave Kleikamp 63470decc6SDave Kleikamp J_ASSERT(journal->j_running_transaction == NULL); 64470decc6SDave Kleikamp journal->j_running_transaction = transaction; 658e85fb3fSJohann Lombardi transaction->t_max_wait = 0; 668e85fb3fSJohann Lombardi transaction->t_start = jiffies; 67470decc6SDave Kleikamp 68470decc6SDave Kleikamp return transaction; 69470decc6SDave Kleikamp } 70470decc6SDave Kleikamp 71470decc6SDave Kleikamp /* 72470decc6SDave Kleikamp * Handle management. 73470decc6SDave Kleikamp * 74470decc6SDave Kleikamp * A handle_t is an object which represents a single atomic update to a 75470decc6SDave Kleikamp * filesystem, and which tracks all of the modifications which form part 76470decc6SDave Kleikamp * of that one update. 77470decc6SDave Kleikamp */ 78470decc6SDave Kleikamp 79470decc6SDave Kleikamp /* 80470decc6SDave Kleikamp * start_this_handle: Given a handle, deal with any locking or stalling 81470decc6SDave Kleikamp * needed to make sure that there is enough journal space for the handle 82470decc6SDave Kleikamp * to begin. Attach the handle to a transaction and set up the 83470decc6SDave Kleikamp * transaction's buffer credits. 84470decc6SDave Kleikamp */ 85470decc6SDave Kleikamp 86470decc6SDave Kleikamp static int start_this_handle(journal_t *journal, handle_t *handle) 87470decc6SDave Kleikamp { 88470decc6SDave Kleikamp transaction_t *transaction; 89470decc6SDave Kleikamp int needed; 90470decc6SDave Kleikamp int nblocks = handle->h_buffer_credits; 91470decc6SDave Kleikamp transaction_t *new_transaction = NULL; 92470decc6SDave Kleikamp int ret = 0; 938e85fb3fSJohann Lombardi unsigned long ts = jiffies; 94470decc6SDave Kleikamp 95470decc6SDave Kleikamp if (nblocks > journal->j_max_transaction_buffers) { 96470decc6SDave Kleikamp printk(KERN_ERR "JBD: %s wants too many credits (%d > %d)\n", 97470decc6SDave Kleikamp current->comm, nblocks, 98470decc6SDave Kleikamp journal->j_max_transaction_buffers); 99470decc6SDave Kleikamp ret = -ENOSPC; 100470decc6SDave Kleikamp goto out; 101470decc6SDave Kleikamp } 102470decc6SDave Kleikamp 103470decc6SDave Kleikamp alloc_transaction: 104470decc6SDave Kleikamp if (!journal->j_running_transaction) { 105d802ffa8SMingming Cao new_transaction = kzalloc(sizeof(*new_transaction), 1062d917969SMingming Cao GFP_NOFS|__GFP_NOFAIL); 107470decc6SDave Kleikamp if (!new_transaction) { 108470decc6SDave Kleikamp ret = -ENOMEM; 109470decc6SDave Kleikamp goto out; 110470decc6SDave Kleikamp } 111470decc6SDave Kleikamp } 112470decc6SDave Kleikamp 113470decc6SDave Kleikamp jbd_debug(3, "New handle %p going live.\n", handle); 114470decc6SDave Kleikamp 115470decc6SDave Kleikamp repeat: 116470decc6SDave Kleikamp 117470decc6SDave Kleikamp /* 118470decc6SDave Kleikamp * We need to hold j_state_lock until t_updates has been incremented, 119470decc6SDave Kleikamp * for proper journal barrier handling 120470decc6SDave Kleikamp */ 121470decc6SDave Kleikamp spin_lock(&journal->j_state_lock); 122470decc6SDave Kleikamp repeat_locked: 123470decc6SDave Kleikamp if (is_journal_aborted(journal) || 124f7f4bccbSMingming Cao (journal->j_errno != 0 && !(journal->j_flags & JBD2_ACK_ERR))) { 125470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 126470decc6SDave Kleikamp ret = -EROFS; 127470decc6SDave Kleikamp goto out; 128470decc6SDave Kleikamp } 129470decc6SDave Kleikamp 130470decc6SDave Kleikamp /* Wait on the journal's transaction barrier if necessary */ 131470decc6SDave Kleikamp if (journal->j_barrier_count) { 132470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 133470decc6SDave Kleikamp wait_event(journal->j_wait_transaction_locked, 134470decc6SDave Kleikamp journal->j_barrier_count == 0); 135470decc6SDave Kleikamp goto repeat; 136470decc6SDave Kleikamp } 137470decc6SDave Kleikamp 138470decc6SDave Kleikamp if (!journal->j_running_transaction) { 139470decc6SDave Kleikamp if (!new_transaction) { 140470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 141470decc6SDave Kleikamp goto alloc_transaction; 142470decc6SDave Kleikamp } 143f7f4bccbSMingming Cao jbd2_get_transaction(journal, new_transaction); 144470decc6SDave Kleikamp new_transaction = NULL; 145470decc6SDave Kleikamp } 146470decc6SDave Kleikamp 147470decc6SDave Kleikamp transaction = journal->j_running_transaction; 148470decc6SDave Kleikamp 149470decc6SDave Kleikamp /* 150470decc6SDave Kleikamp * If the current transaction is locked down for commit, wait for the 151470decc6SDave Kleikamp * lock to be released. 152470decc6SDave Kleikamp */ 153470decc6SDave Kleikamp if (transaction->t_state == T_LOCKED) { 154470decc6SDave Kleikamp DEFINE_WAIT(wait); 155470decc6SDave Kleikamp 156470decc6SDave Kleikamp prepare_to_wait(&journal->j_wait_transaction_locked, 157470decc6SDave Kleikamp &wait, TASK_UNINTERRUPTIBLE); 158470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 159470decc6SDave Kleikamp schedule(); 160470decc6SDave Kleikamp finish_wait(&journal->j_wait_transaction_locked, &wait); 161470decc6SDave Kleikamp goto repeat; 162470decc6SDave Kleikamp } 163470decc6SDave Kleikamp 164470decc6SDave Kleikamp /* 165470decc6SDave Kleikamp * If there is not enough space left in the log to write all potential 166470decc6SDave Kleikamp * buffers requested by this operation, we need to stall pending a log 167470decc6SDave Kleikamp * checkpoint to free some more log space. 168470decc6SDave Kleikamp */ 169470decc6SDave Kleikamp spin_lock(&transaction->t_handle_lock); 170470decc6SDave Kleikamp needed = transaction->t_outstanding_credits + nblocks; 171470decc6SDave Kleikamp 172470decc6SDave Kleikamp if (needed > journal->j_max_transaction_buffers) { 173470decc6SDave Kleikamp /* 174470decc6SDave Kleikamp * If the current transaction is already too large, then start 175470decc6SDave Kleikamp * to commit it: we can then go back and attach this handle to 176470decc6SDave Kleikamp * a new transaction. 177470decc6SDave Kleikamp */ 178470decc6SDave Kleikamp DEFINE_WAIT(wait); 179470decc6SDave Kleikamp 180470decc6SDave Kleikamp jbd_debug(2, "Handle %p starting new commit...\n", handle); 181470decc6SDave Kleikamp spin_unlock(&transaction->t_handle_lock); 182470decc6SDave Kleikamp prepare_to_wait(&journal->j_wait_transaction_locked, &wait, 183470decc6SDave Kleikamp TASK_UNINTERRUPTIBLE); 184f7f4bccbSMingming Cao __jbd2_log_start_commit(journal, transaction->t_tid); 185470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 186470decc6SDave Kleikamp schedule(); 187470decc6SDave Kleikamp finish_wait(&journal->j_wait_transaction_locked, &wait); 188470decc6SDave Kleikamp goto repeat; 189470decc6SDave Kleikamp } 190470decc6SDave Kleikamp 191470decc6SDave Kleikamp /* 192470decc6SDave Kleikamp * The commit code assumes that it can get enough log space 193470decc6SDave Kleikamp * without forcing a checkpoint. This is *critical* for 194470decc6SDave Kleikamp * correctness: a checkpoint of a buffer which is also 195470decc6SDave Kleikamp * associated with a committing transaction creates a deadlock, 196470decc6SDave Kleikamp * so commit simply cannot force through checkpoints. 197470decc6SDave Kleikamp * 198470decc6SDave Kleikamp * We must therefore ensure the necessary space in the journal 199470decc6SDave Kleikamp * *before* starting to dirty potentially checkpointed buffers 200470decc6SDave Kleikamp * in the new transaction. 201470decc6SDave Kleikamp * 202470decc6SDave Kleikamp * The worst part is, any transaction currently committing can 203470decc6SDave Kleikamp * reduce the free space arbitrarily. Be careful to account for 204470decc6SDave Kleikamp * those buffers when checkpointing. 205470decc6SDave Kleikamp */ 206470decc6SDave Kleikamp 207470decc6SDave Kleikamp /* 208470decc6SDave Kleikamp * @@@ AKPM: This seems rather over-defensive. We're giving commit 209470decc6SDave Kleikamp * a _lot_ of headroom: 1/4 of the journal plus the size of 210470decc6SDave Kleikamp * the committing transaction. Really, we only need to give it 211470decc6SDave Kleikamp * committing_transaction->t_outstanding_credits plus "enough" for 212470decc6SDave Kleikamp * the log control blocks. 213470decc6SDave Kleikamp * Also, this test is inconsitent with the matching one in 214f7f4bccbSMingming Cao * jbd2_journal_extend(). 215470decc6SDave Kleikamp */ 216f7f4bccbSMingming Cao if (__jbd2_log_space_left(journal) < jbd_space_needed(journal)) { 217470decc6SDave Kleikamp jbd_debug(2, "Handle %p waiting for checkpoint...\n", handle); 218470decc6SDave Kleikamp spin_unlock(&transaction->t_handle_lock); 219f7f4bccbSMingming Cao __jbd2_log_wait_for_space(journal); 220470decc6SDave Kleikamp goto repeat_locked; 221470decc6SDave Kleikamp } 222470decc6SDave Kleikamp 223470decc6SDave Kleikamp /* OK, account for the buffers that this operation expects to 224470decc6SDave Kleikamp * use and add the handle to the running transaction. */ 225470decc6SDave Kleikamp 2268e85fb3fSJohann Lombardi if (time_after(transaction->t_start, ts)) { 2278e85fb3fSJohann Lombardi ts = jbd2_time_diff(ts, transaction->t_start); 2288e85fb3fSJohann Lombardi if (ts > transaction->t_max_wait) 2298e85fb3fSJohann Lombardi transaction->t_max_wait = ts; 2308e85fb3fSJohann Lombardi } 2318e85fb3fSJohann Lombardi 232470decc6SDave Kleikamp handle->h_transaction = transaction; 233470decc6SDave Kleikamp transaction->t_outstanding_credits += nblocks; 234470decc6SDave Kleikamp transaction->t_updates++; 235470decc6SDave Kleikamp transaction->t_handle_count++; 236470decc6SDave Kleikamp jbd_debug(4, "Handle %p given %d credits (total %d, free %d)\n", 237470decc6SDave Kleikamp handle, nblocks, transaction->t_outstanding_credits, 238f7f4bccbSMingming Cao __jbd2_log_space_left(journal)); 239470decc6SDave Kleikamp spin_unlock(&transaction->t_handle_lock); 240470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 2419599b0e5SJan Kara 2429599b0e5SJan Kara lock_map_acquire(&handle->h_lockdep_map); 243470decc6SDave Kleikamp out: 244470decc6SDave Kleikamp if (unlikely(new_transaction)) /* It's usually NULL */ 245470decc6SDave Kleikamp kfree(new_transaction); 246470decc6SDave Kleikamp return ret; 247470decc6SDave Kleikamp } 248470decc6SDave Kleikamp 2497b751066SMingming Cao static struct lock_class_key jbd2_handle_key; 2507b751066SMingming Cao 251470decc6SDave Kleikamp /* Allocate a new handle. This should probably be in a slab... */ 252470decc6SDave Kleikamp static handle_t *new_handle(int nblocks) 253470decc6SDave Kleikamp { 254af1e76d6SMingming Cao handle_t *handle = jbd2_alloc_handle(GFP_NOFS); 255470decc6SDave Kleikamp if (!handle) 256470decc6SDave Kleikamp return NULL; 257470decc6SDave Kleikamp memset(handle, 0, sizeof(*handle)); 258470decc6SDave Kleikamp handle->h_buffer_credits = nblocks; 259470decc6SDave Kleikamp handle->h_ref = 1; 260470decc6SDave Kleikamp 2617b751066SMingming Cao lockdep_init_map(&handle->h_lockdep_map, "jbd2_handle", 2627b751066SMingming Cao &jbd2_handle_key, 0); 2637b751066SMingming Cao 264470decc6SDave Kleikamp return handle; 265470decc6SDave Kleikamp } 266470decc6SDave Kleikamp 267470decc6SDave Kleikamp /** 268f7f4bccbSMingming Cao * handle_t *jbd2_journal_start() - Obtain a new handle. 269470decc6SDave Kleikamp * @journal: Journal to start transaction on. 270470decc6SDave Kleikamp * @nblocks: number of block buffer we might modify 271470decc6SDave Kleikamp * 272470decc6SDave Kleikamp * We make sure that the transaction can guarantee at least nblocks of 273470decc6SDave Kleikamp * modified buffers in the log. We block until the log can guarantee 274470decc6SDave Kleikamp * that much space. 275470decc6SDave Kleikamp * 276470decc6SDave Kleikamp * This function is visible to journal users (like ext3fs), so is not 277470decc6SDave Kleikamp * called with the journal already locked. 278470decc6SDave Kleikamp * 279470decc6SDave Kleikamp * Return a pointer to a newly allocated handle, or NULL on failure 280470decc6SDave Kleikamp */ 281f7f4bccbSMingming Cao handle_t *jbd2_journal_start(journal_t *journal, int nblocks) 282470decc6SDave Kleikamp { 283470decc6SDave Kleikamp handle_t *handle = journal_current_handle(); 284470decc6SDave Kleikamp int err; 285470decc6SDave Kleikamp 286470decc6SDave Kleikamp if (!journal) 287470decc6SDave Kleikamp return ERR_PTR(-EROFS); 288470decc6SDave Kleikamp 289470decc6SDave Kleikamp if (handle) { 290470decc6SDave Kleikamp J_ASSERT(handle->h_transaction->t_journal == journal); 291470decc6SDave Kleikamp handle->h_ref++; 292470decc6SDave Kleikamp return handle; 293470decc6SDave Kleikamp } 294470decc6SDave Kleikamp 295470decc6SDave Kleikamp handle = new_handle(nblocks); 296470decc6SDave Kleikamp if (!handle) 297470decc6SDave Kleikamp return ERR_PTR(-ENOMEM); 298470decc6SDave Kleikamp 299470decc6SDave Kleikamp current->journal_info = handle; 300470decc6SDave Kleikamp 301470decc6SDave Kleikamp err = start_this_handle(journal, handle); 302470decc6SDave Kleikamp if (err < 0) { 303af1e76d6SMingming Cao jbd2_free_handle(handle); 304470decc6SDave Kleikamp current->journal_info = NULL; 305470decc6SDave Kleikamp handle = ERR_PTR(err); 3067b751066SMingming Cao goto out; 307470decc6SDave Kleikamp } 3087b751066SMingming Cao out: 309470decc6SDave Kleikamp return handle; 310470decc6SDave Kleikamp } 311470decc6SDave Kleikamp 312470decc6SDave Kleikamp /** 313f7f4bccbSMingming Cao * int jbd2_journal_extend() - extend buffer credits. 314470decc6SDave Kleikamp * @handle: handle to 'extend' 315470decc6SDave Kleikamp * @nblocks: nr blocks to try to extend by. 316470decc6SDave Kleikamp * 317470decc6SDave Kleikamp * Some transactions, such as large extends and truncates, can be done 318470decc6SDave Kleikamp * atomically all at once or in several stages. The operation requests 319470decc6SDave Kleikamp * a credit for a number of buffer modications in advance, but can 320470decc6SDave Kleikamp * extend its credit if it needs more. 321470decc6SDave Kleikamp * 322f7f4bccbSMingming Cao * jbd2_journal_extend tries to give the running handle more buffer credits. 323470decc6SDave Kleikamp * It does not guarantee that allocation - this is a best-effort only. 324470decc6SDave Kleikamp * The calling process MUST be able to deal cleanly with a failure to 325470decc6SDave Kleikamp * extend here. 326470decc6SDave Kleikamp * 327470decc6SDave Kleikamp * Return 0 on success, non-zero on failure. 328470decc6SDave Kleikamp * 329470decc6SDave Kleikamp * return code < 0 implies an error 330470decc6SDave Kleikamp * return code > 0 implies normal transaction-full status. 331470decc6SDave Kleikamp */ 332f7f4bccbSMingming Cao int jbd2_journal_extend(handle_t *handle, int nblocks) 333470decc6SDave Kleikamp { 334470decc6SDave Kleikamp transaction_t *transaction = handle->h_transaction; 335470decc6SDave Kleikamp journal_t *journal = transaction->t_journal; 336470decc6SDave Kleikamp int result; 337470decc6SDave Kleikamp int wanted; 338470decc6SDave Kleikamp 339470decc6SDave Kleikamp result = -EIO; 340470decc6SDave Kleikamp if (is_handle_aborted(handle)) 341470decc6SDave Kleikamp goto out; 342470decc6SDave Kleikamp 343470decc6SDave Kleikamp result = 1; 344470decc6SDave Kleikamp 345470decc6SDave Kleikamp spin_lock(&journal->j_state_lock); 346470decc6SDave Kleikamp 347470decc6SDave Kleikamp /* Don't extend a locked-down transaction! */ 348470decc6SDave Kleikamp if (handle->h_transaction->t_state != T_RUNNING) { 349470decc6SDave Kleikamp jbd_debug(3, "denied handle %p %d blocks: " 350470decc6SDave Kleikamp "transaction not running\n", handle, nblocks); 351470decc6SDave Kleikamp goto error_out; 352470decc6SDave Kleikamp } 353470decc6SDave Kleikamp 354470decc6SDave Kleikamp spin_lock(&transaction->t_handle_lock); 355470decc6SDave Kleikamp wanted = transaction->t_outstanding_credits + nblocks; 356470decc6SDave Kleikamp 357470decc6SDave Kleikamp if (wanted > journal->j_max_transaction_buffers) { 358470decc6SDave Kleikamp jbd_debug(3, "denied handle %p %d blocks: " 359470decc6SDave Kleikamp "transaction too large\n", handle, nblocks); 360470decc6SDave Kleikamp goto unlock; 361470decc6SDave Kleikamp } 362470decc6SDave Kleikamp 363f7f4bccbSMingming Cao if (wanted > __jbd2_log_space_left(journal)) { 364470decc6SDave Kleikamp jbd_debug(3, "denied handle %p %d blocks: " 365470decc6SDave Kleikamp "insufficient log space\n", handle, nblocks); 366470decc6SDave Kleikamp goto unlock; 367470decc6SDave Kleikamp } 368470decc6SDave Kleikamp 369470decc6SDave Kleikamp handle->h_buffer_credits += nblocks; 370470decc6SDave Kleikamp transaction->t_outstanding_credits += nblocks; 371470decc6SDave Kleikamp result = 0; 372470decc6SDave Kleikamp 373470decc6SDave Kleikamp jbd_debug(3, "extended handle %p by %d\n", handle, nblocks); 374470decc6SDave Kleikamp unlock: 375470decc6SDave Kleikamp spin_unlock(&transaction->t_handle_lock); 376470decc6SDave Kleikamp error_out: 377470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 378470decc6SDave Kleikamp out: 379470decc6SDave Kleikamp return result; 380470decc6SDave Kleikamp } 381470decc6SDave Kleikamp 382470decc6SDave Kleikamp 383470decc6SDave Kleikamp /** 384f7f4bccbSMingming Cao * int jbd2_journal_restart() - restart a handle . 385470decc6SDave Kleikamp * @handle: handle to restart 386470decc6SDave Kleikamp * @nblocks: nr credits requested 387470decc6SDave Kleikamp * 388470decc6SDave Kleikamp * Restart a handle for a multi-transaction filesystem 389470decc6SDave Kleikamp * operation. 390470decc6SDave Kleikamp * 391f7f4bccbSMingming Cao * If the jbd2_journal_extend() call above fails to grant new buffer credits 392f7f4bccbSMingming Cao * to a running handle, a call to jbd2_journal_restart will commit the 393470decc6SDave Kleikamp * handle's transaction so far and reattach the handle to a new 394470decc6SDave Kleikamp * transaction capabable of guaranteeing the requested number of 395470decc6SDave Kleikamp * credits. 396470decc6SDave Kleikamp */ 397470decc6SDave Kleikamp 398f7f4bccbSMingming Cao int jbd2_journal_restart(handle_t *handle, int nblocks) 399470decc6SDave Kleikamp { 400470decc6SDave Kleikamp transaction_t *transaction = handle->h_transaction; 401470decc6SDave Kleikamp journal_t *journal = transaction->t_journal; 402470decc6SDave Kleikamp int ret; 403470decc6SDave Kleikamp 404470decc6SDave Kleikamp /* If we've had an abort of any type, don't even think about 405470decc6SDave Kleikamp * actually doing the restart! */ 406470decc6SDave Kleikamp if (is_handle_aborted(handle)) 407470decc6SDave Kleikamp return 0; 408470decc6SDave Kleikamp 409470decc6SDave Kleikamp /* 410470decc6SDave Kleikamp * First unlink the handle from its current transaction, and start the 411470decc6SDave Kleikamp * commit on that. 412470decc6SDave Kleikamp */ 413470decc6SDave Kleikamp J_ASSERT(transaction->t_updates > 0); 414470decc6SDave Kleikamp J_ASSERT(journal_current_handle() == handle); 415470decc6SDave Kleikamp 416470decc6SDave Kleikamp spin_lock(&journal->j_state_lock); 417470decc6SDave Kleikamp spin_lock(&transaction->t_handle_lock); 418470decc6SDave Kleikamp transaction->t_outstanding_credits -= handle->h_buffer_credits; 419470decc6SDave Kleikamp transaction->t_updates--; 420470decc6SDave Kleikamp 421470decc6SDave Kleikamp if (!transaction->t_updates) 422470decc6SDave Kleikamp wake_up(&journal->j_wait_updates); 423470decc6SDave Kleikamp spin_unlock(&transaction->t_handle_lock); 424470decc6SDave Kleikamp 425470decc6SDave Kleikamp jbd_debug(2, "restarting handle %p\n", handle); 426f7f4bccbSMingming Cao __jbd2_log_start_commit(journal, transaction->t_tid); 427470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 428470decc6SDave Kleikamp 4299599b0e5SJan Kara lock_map_release(&handle->h_lockdep_map); 430470decc6SDave Kleikamp handle->h_buffer_credits = nblocks; 431470decc6SDave Kleikamp ret = start_this_handle(journal, handle); 432470decc6SDave Kleikamp return ret; 433470decc6SDave Kleikamp } 434470decc6SDave Kleikamp 435470decc6SDave Kleikamp 436470decc6SDave Kleikamp /** 437f7f4bccbSMingming Cao * void jbd2_journal_lock_updates () - establish a transaction barrier. 438470decc6SDave Kleikamp * @journal: Journal to establish a barrier on. 439470decc6SDave Kleikamp * 440470decc6SDave Kleikamp * This locks out any further updates from being started, and blocks 441470decc6SDave Kleikamp * until all existing updates have completed, returning only once the 442470decc6SDave Kleikamp * journal is in a quiescent state with no updates running. 443470decc6SDave Kleikamp * 444470decc6SDave Kleikamp * The journal lock should not be held on entry. 445470decc6SDave Kleikamp */ 446f7f4bccbSMingming Cao void jbd2_journal_lock_updates(journal_t *journal) 447470decc6SDave Kleikamp { 448470decc6SDave Kleikamp DEFINE_WAIT(wait); 449470decc6SDave Kleikamp 450470decc6SDave Kleikamp spin_lock(&journal->j_state_lock); 451470decc6SDave Kleikamp ++journal->j_barrier_count; 452470decc6SDave Kleikamp 453470decc6SDave Kleikamp /* Wait until there are no running updates */ 454470decc6SDave Kleikamp while (1) { 455470decc6SDave Kleikamp transaction_t *transaction = journal->j_running_transaction; 456470decc6SDave Kleikamp 457470decc6SDave Kleikamp if (!transaction) 458470decc6SDave Kleikamp break; 459470decc6SDave Kleikamp 460470decc6SDave Kleikamp spin_lock(&transaction->t_handle_lock); 461470decc6SDave Kleikamp if (!transaction->t_updates) { 462470decc6SDave Kleikamp spin_unlock(&transaction->t_handle_lock); 463470decc6SDave Kleikamp break; 464470decc6SDave Kleikamp } 465470decc6SDave Kleikamp prepare_to_wait(&journal->j_wait_updates, &wait, 466470decc6SDave Kleikamp TASK_UNINTERRUPTIBLE); 467470decc6SDave Kleikamp spin_unlock(&transaction->t_handle_lock); 468470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 469470decc6SDave Kleikamp schedule(); 470470decc6SDave Kleikamp finish_wait(&journal->j_wait_updates, &wait); 471470decc6SDave Kleikamp spin_lock(&journal->j_state_lock); 472470decc6SDave Kleikamp } 473470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 474470decc6SDave Kleikamp 475470decc6SDave Kleikamp /* 476470decc6SDave Kleikamp * We have now established a barrier against other normal updates, but 477f7f4bccbSMingming Cao * we also need to barrier against other jbd2_journal_lock_updates() calls 478470decc6SDave Kleikamp * to make sure that we serialise special journal-locked operations 479470decc6SDave Kleikamp * too. 480470decc6SDave Kleikamp */ 481470decc6SDave Kleikamp mutex_lock(&journal->j_barrier); 482470decc6SDave Kleikamp } 483470decc6SDave Kleikamp 484470decc6SDave Kleikamp /** 485f7f4bccbSMingming Cao * void jbd2_journal_unlock_updates (journal_t* journal) - release barrier 486470decc6SDave Kleikamp * @journal: Journal to release the barrier on. 487470decc6SDave Kleikamp * 488f7f4bccbSMingming Cao * Release a transaction barrier obtained with jbd2_journal_lock_updates(). 489470decc6SDave Kleikamp * 490470decc6SDave Kleikamp * Should be called without the journal lock held. 491470decc6SDave Kleikamp */ 492f7f4bccbSMingming Cao void jbd2_journal_unlock_updates (journal_t *journal) 493470decc6SDave Kleikamp { 494470decc6SDave Kleikamp J_ASSERT(journal->j_barrier_count != 0); 495470decc6SDave Kleikamp 496470decc6SDave Kleikamp mutex_unlock(&journal->j_barrier); 497470decc6SDave Kleikamp spin_lock(&journal->j_state_lock); 498470decc6SDave Kleikamp --journal->j_barrier_count; 499470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 500470decc6SDave Kleikamp wake_up(&journal->j_wait_transaction_locked); 501470decc6SDave Kleikamp } 502470decc6SDave Kleikamp 503f91d1d04SJan Kara static void warn_dirty_buffer(struct buffer_head *bh) 504470decc6SDave Kleikamp { 505f91d1d04SJan Kara char b[BDEVNAME_SIZE]; 506470decc6SDave Kleikamp 507f91d1d04SJan Kara printk(KERN_WARNING 508f91d1d04SJan Kara "JBD: Spotted dirty metadata buffer (dev = %s, blocknr = %llu). " 509f91d1d04SJan Kara "There's a risk of filesystem corruption in case of system " 510f91d1d04SJan Kara "crash.\n", 511f91d1d04SJan Kara bdevname(bh->b_bdev, b), (unsigned long long)bh->b_blocknr); 512470decc6SDave Kleikamp } 513470decc6SDave Kleikamp 514470decc6SDave Kleikamp /* 515470decc6SDave Kleikamp * If the buffer is already part of the current transaction, then there 516470decc6SDave Kleikamp * is nothing we need to do. If it is already part of a prior 517470decc6SDave Kleikamp * transaction which we are still committing to disk, then we need to 518470decc6SDave Kleikamp * make sure that we do not overwrite the old copy: we do copy-out to 519470decc6SDave Kleikamp * preserve the copy going to disk. We also account the buffer against 520470decc6SDave Kleikamp * the handle's metadata buffer credits (unless the buffer is already 521470decc6SDave Kleikamp * part of the transaction, that is). 522470decc6SDave Kleikamp * 523470decc6SDave Kleikamp */ 524470decc6SDave Kleikamp static int 525470decc6SDave Kleikamp do_get_write_access(handle_t *handle, struct journal_head *jh, 526470decc6SDave Kleikamp int force_copy) 527470decc6SDave Kleikamp { 528470decc6SDave Kleikamp struct buffer_head *bh; 529470decc6SDave Kleikamp transaction_t *transaction; 530470decc6SDave Kleikamp journal_t *journal; 531470decc6SDave Kleikamp int error; 532470decc6SDave Kleikamp char *frozen_buffer = NULL; 533470decc6SDave Kleikamp int need_copy = 0; 534470decc6SDave Kleikamp 535470decc6SDave Kleikamp if (is_handle_aborted(handle)) 536470decc6SDave Kleikamp return -EROFS; 537470decc6SDave Kleikamp 538470decc6SDave Kleikamp transaction = handle->h_transaction; 539470decc6SDave Kleikamp journal = transaction->t_journal; 540470decc6SDave Kleikamp 541470decc6SDave Kleikamp jbd_debug(5, "buffer_head %p, force_copy %d\n", jh, force_copy); 542470decc6SDave Kleikamp 543470decc6SDave Kleikamp JBUFFER_TRACE(jh, "entry"); 544470decc6SDave Kleikamp repeat: 545470decc6SDave Kleikamp bh = jh2bh(jh); 546470decc6SDave Kleikamp 547470decc6SDave Kleikamp /* @@@ Need to check for errors here at some point. */ 548470decc6SDave Kleikamp 549470decc6SDave Kleikamp lock_buffer(bh); 550470decc6SDave Kleikamp jbd_lock_bh_state(bh); 551470decc6SDave Kleikamp 552470decc6SDave Kleikamp /* We now hold the buffer lock so it is safe to query the buffer 553470decc6SDave Kleikamp * state. Is the buffer dirty? 554470decc6SDave Kleikamp * 555470decc6SDave Kleikamp * If so, there are two possibilities. The buffer may be 556470decc6SDave Kleikamp * non-journaled, and undergoing a quite legitimate writeback. 557470decc6SDave Kleikamp * Otherwise, it is journaled, and we don't expect dirty buffers 558470decc6SDave Kleikamp * in that state (the buffers should be marked JBD_Dirty 559470decc6SDave Kleikamp * instead.) So either the IO is being done under our own 560470decc6SDave Kleikamp * control and this is a bug, or it's a third party IO such as 561470decc6SDave Kleikamp * dump(8) (which may leave the buffer scheduled for read --- 562470decc6SDave Kleikamp * ie. locked but not dirty) or tune2fs (which may actually have 563470decc6SDave Kleikamp * the buffer dirtied, ugh.) */ 564470decc6SDave Kleikamp 565470decc6SDave Kleikamp if (buffer_dirty(bh)) { 566470decc6SDave Kleikamp /* 567470decc6SDave Kleikamp * First question: is this buffer already part of the current 568470decc6SDave Kleikamp * transaction or the existing committing transaction? 569470decc6SDave Kleikamp */ 570470decc6SDave Kleikamp if (jh->b_transaction) { 571470decc6SDave Kleikamp J_ASSERT_JH(jh, 572470decc6SDave Kleikamp jh->b_transaction == transaction || 573470decc6SDave Kleikamp jh->b_transaction == 574470decc6SDave Kleikamp journal->j_committing_transaction); 575470decc6SDave Kleikamp if (jh->b_next_transaction) 576470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_next_transaction == 577470decc6SDave Kleikamp transaction); 578f91d1d04SJan Kara warn_dirty_buffer(bh); 579470decc6SDave Kleikamp } 580470decc6SDave Kleikamp /* 581470decc6SDave Kleikamp * In any case we need to clean the dirty flag and we must 582470decc6SDave Kleikamp * do it under the buffer lock to be sure we don't race 583470decc6SDave Kleikamp * with running write-out. 584470decc6SDave Kleikamp */ 585f91d1d04SJan Kara JBUFFER_TRACE(jh, "Journalling dirty buffer"); 586f91d1d04SJan Kara clear_buffer_dirty(bh); 587f91d1d04SJan Kara set_buffer_jbddirty(bh); 588470decc6SDave Kleikamp } 589470decc6SDave Kleikamp 590470decc6SDave Kleikamp unlock_buffer(bh); 591470decc6SDave Kleikamp 592470decc6SDave Kleikamp error = -EROFS; 593470decc6SDave Kleikamp if (is_handle_aborted(handle)) { 594470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 595470decc6SDave Kleikamp goto out; 596470decc6SDave Kleikamp } 597470decc6SDave Kleikamp error = 0; 598470decc6SDave Kleikamp 599470decc6SDave Kleikamp /* 600470decc6SDave Kleikamp * The buffer is already part of this transaction if b_transaction or 601470decc6SDave Kleikamp * b_next_transaction points to it 602470decc6SDave Kleikamp */ 603470decc6SDave Kleikamp if (jh->b_transaction == transaction || 604470decc6SDave Kleikamp jh->b_next_transaction == transaction) 605470decc6SDave Kleikamp goto done; 606470decc6SDave Kleikamp 607470decc6SDave Kleikamp /* 6089fc7c63aSJosef Bacik * this is the first time this transaction is touching this buffer, 6099fc7c63aSJosef Bacik * reset the modified flag 6109fc7c63aSJosef Bacik */ 6119fc7c63aSJosef Bacik jh->b_modified = 0; 6129fc7c63aSJosef Bacik 6139fc7c63aSJosef Bacik /* 614470decc6SDave Kleikamp * If there is already a copy-out version of this buffer, then we don't 615470decc6SDave Kleikamp * need to make another one 616470decc6SDave Kleikamp */ 617470decc6SDave Kleikamp if (jh->b_frozen_data) { 618470decc6SDave Kleikamp JBUFFER_TRACE(jh, "has frozen data"); 619470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_next_transaction == NULL); 620470decc6SDave Kleikamp jh->b_next_transaction = transaction; 621470decc6SDave Kleikamp goto done; 622470decc6SDave Kleikamp } 623470decc6SDave Kleikamp 624470decc6SDave Kleikamp /* Is there data here we need to preserve? */ 625470decc6SDave Kleikamp 626470decc6SDave Kleikamp if (jh->b_transaction && jh->b_transaction != transaction) { 627470decc6SDave Kleikamp JBUFFER_TRACE(jh, "owned by older transaction"); 628470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_next_transaction == NULL); 629470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_transaction == 630470decc6SDave Kleikamp journal->j_committing_transaction); 631470decc6SDave Kleikamp 632470decc6SDave Kleikamp /* There is one case we have to be very careful about. 633470decc6SDave Kleikamp * If the committing transaction is currently writing 634470decc6SDave Kleikamp * this buffer out to disk and has NOT made a copy-out, 635470decc6SDave Kleikamp * then we cannot modify the buffer contents at all 636470decc6SDave Kleikamp * right now. The essence of copy-out is that it is the 637470decc6SDave Kleikamp * extra copy, not the primary copy, which gets 638470decc6SDave Kleikamp * journaled. If the primary copy is already going to 639470decc6SDave Kleikamp * disk then we cannot do copy-out here. */ 640470decc6SDave Kleikamp 641470decc6SDave Kleikamp if (jh->b_jlist == BJ_Shadow) { 642470decc6SDave Kleikamp DEFINE_WAIT_BIT(wait, &bh->b_state, BH_Unshadow); 643470decc6SDave Kleikamp wait_queue_head_t *wqh; 644470decc6SDave Kleikamp 645470decc6SDave Kleikamp wqh = bit_waitqueue(&bh->b_state, BH_Unshadow); 646470decc6SDave Kleikamp 647470decc6SDave Kleikamp JBUFFER_TRACE(jh, "on shadow: sleep"); 648470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 649470decc6SDave Kleikamp /* commit wakes up all shadow buffers after IO */ 650470decc6SDave Kleikamp for ( ; ; ) { 651470decc6SDave Kleikamp prepare_to_wait(wqh, &wait.wait, 652470decc6SDave Kleikamp TASK_UNINTERRUPTIBLE); 653470decc6SDave Kleikamp if (jh->b_jlist != BJ_Shadow) 654470decc6SDave Kleikamp break; 655470decc6SDave Kleikamp schedule(); 656470decc6SDave Kleikamp } 657470decc6SDave Kleikamp finish_wait(wqh, &wait.wait); 658470decc6SDave Kleikamp goto repeat; 659470decc6SDave Kleikamp } 660470decc6SDave Kleikamp 661470decc6SDave Kleikamp /* Only do the copy if the currently-owning transaction 662470decc6SDave Kleikamp * still needs it. If it is on the Forget list, the 663470decc6SDave Kleikamp * committing transaction is past that stage. The 664470decc6SDave Kleikamp * buffer had better remain locked during the kmalloc, 665470decc6SDave Kleikamp * but that should be true --- we hold the journal lock 666470decc6SDave Kleikamp * still and the buffer is already on the BUF_JOURNAL 667470decc6SDave Kleikamp * list so won't be flushed. 668470decc6SDave Kleikamp * 669470decc6SDave Kleikamp * Subtle point, though: if this is a get_undo_access, 670470decc6SDave Kleikamp * then we will be relying on the frozen_data to contain 671470decc6SDave Kleikamp * the new value of the committed_data record after the 672470decc6SDave Kleikamp * transaction, so we HAVE to force the frozen_data copy 673470decc6SDave Kleikamp * in that case. */ 674470decc6SDave Kleikamp 675470decc6SDave Kleikamp if (jh->b_jlist != BJ_Forget || force_copy) { 676470decc6SDave Kleikamp JBUFFER_TRACE(jh, "generate frozen data"); 677470decc6SDave Kleikamp if (!frozen_buffer) { 678470decc6SDave Kleikamp JBUFFER_TRACE(jh, "allocate memory for buffer"); 679470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 680470decc6SDave Kleikamp frozen_buffer = 681af1e76d6SMingming Cao jbd2_alloc(jh2bh(jh)->b_size, 682470decc6SDave Kleikamp GFP_NOFS); 683470decc6SDave Kleikamp if (!frozen_buffer) { 684470decc6SDave Kleikamp printk(KERN_EMERG 685470decc6SDave Kleikamp "%s: OOM for frozen_buffer\n", 686329d291fSHarvey Harrison __func__); 687470decc6SDave Kleikamp JBUFFER_TRACE(jh, "oom!"); 688470decc6SDave Kleikamp error = -ENOMEM; 689470decc6SDave Kleikamp jbd_lock_bh_state(bh); 690470decc6SDave Kleikamp goto done; 691470decc6SDave Kleikamp } 692470decc6SDave Kleikamp goto repeat; 693470decc6SDave Kleikamp } 694470decc6SDave Kleikamp jh->b_frozen_data = frozen_buffer; 695470decc6SDave Kleikamp frozen_buffer = NULL; 696470decc6SDave Kleikamp need_copy = 1; 697470decc6SDave Kleikamp } 698470decc6SDave Kleikamp jh->b_next_transaction = transaction; 699470decc6SDave Kleikamp } 700470decc6SDave Kleikamp 701470decc6SDave Kleikamp 702470decc6SDave Kleikamp /* 703470decc6SDave Kleikamp * Finally, if the buffer is not journaled right now, we need to make 704470decc6SDave Kleikamp * sure it doesn't get written to disk before the caller actually 705470decc6SDave Kleikamp * commits the new data 706470decc6SDave Kleikamp */ 707470decc6SDave Kleikamp if (!jh->b_transaction) { 708470decc6SDave Kleikamp JBUFFER_TRACE(jh, "no transaction"); 709470decc6SDave Kleikamp J_ASSERT_JH(jh, !jh->b_next_transaction); 710470decc6SDave Kleikamp jh->b_transaction = transaction; 711470decc6SDave Kleikamp JBUFFER_TRACE(jh, "file as BJ_Reserved"); 712470decc6SDave Kleikamp spin_lock(&journal->j_list_lock); 713f7f4bccbSMingming Cao __jbd2_journal_file_buffer(jh, transaction, BJ_Reserved); 714470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 715470decc6SDave Kleikamp } 716470decc6SDave Kleikamp 717470decc6SDave Kleikamp done: 718470decc6SDave Kleikamp if (need_copy) { 719470decc6SDave Kleikamp struct page *page; 720470decc6SDave Kleikamp int offset; 721470decc6SDave Kleikamp char *source; 722470decc6SDave Kleikamp 723470decc6SDave Kleikamp J_EXPECT_JH(jh, buffer_uptodate(jh2bh(jh)), 724470decc6SDave Kleikamp "Possible IO failure.\n"); 725470decc6SDave Kleikamp page = jh2bh(jh)->b_page; 726470decc6SDave Kleikamp offset = ((unsigned long) jh2bh(jh)->b_data) & ~PAGE_MASK; 727470decc6SDave Kleikamp source = kmap_atomic(page, KM_USER0); 72813ceef09SJan Kara /* Fire data frozen trigger just before we copy the data */ 72913ceef09SJan Kara jbd2_buffer_frozen_trigger(jh, source + offset, 73013ceef09SJan Kara jh->b_triggers); 731470decc6SDave Kleikamp memcpy(jh->b_frozen_data, source+offset, jh2bh(jh)->b_size); 732470decc6SDave Kleikamp kunmap_atomic(source, KM_USER0); 733e06c8227SJoel Becker 734e06c8227SJoel Becker /* 735e06c8227SJoel Becker * Now that the frozen data is saved off, we need to store 736e06c8227SJoel Becker * any matching triggers. 737e06c8227SJoel Becker */ 738e06c8227SJoel Becker jh->b_frozen_triggers = jh->b_triggers; 739470decc6SDave Kleikamp } 740470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 741470decc6SDave Kleikamp 742470decc6SDave Kleikamp /* 743470decc6SDave Kleikamp * If we are about to journal a buffer, then any revoke pending on it is 744470decc6SDave Kleikamp * no longer valid 745470decc6SDave Kleikamp */ 746f7f4bccbSMingming Cao jbd2_journal_cancel_revoke(handle, jh); 747470decc6SDave Kleikamp 748470decc6SDave Kleikamp out: 749470decc6SDave Kleikamp if (unlikely(frozen_buffer)) /* It's usually NULL */ 750af1e76d6SMingming Cao jbd2_free(frozen_buffer, bh->b_size); 751470decc6SDave Kleikamp 752470decc6SDave Kleikamp JBUFFER_TRACE(jh, "exit"); 753470decc6SDave Kleikamp return error; 754470decc6SDave Kleikamp } 755470decc6SDave Kleikamp 756470decc6SDave Kleikamp /** 757f7f4bccbSMingming Cao * int jbd2_journal_get_write_access() - notify intent to modify a buffer for metadata (not data) update. 758470decc6SDave Kleikamp * @handle: transaction to add buffer modifications to 759470decc6SDave Kleikamp * @bh: bh to be used for metadata writes 760470decc6SDave Kleikamp * @credits: variable that will receive credits for the buffer 761470decc6SDave Kleikamp * 762470decc6SDave Kleikamp * Returns an error code or 0 on success. 763470decc6SDave Kleikamp * 764470decc6SDave Kleikamp * In full data journalling mode the buffer may be of type BJ_AsyncData, 765470decc6SDave Kleikamp * because we're write()ing a buffer which is also part of a shared mapping. 766470decc6SDave Kleikamp */ 767470decc6SDave Kleikamp 768f7f4bccbSMingming Cao int jbd2_journal_get_write_access(handle_t *handle, struct buffer_head *bh) 769470decc6SDave Kleikamp { 770f7f4bccbSMingming Cao struct journal_head *jh = jbd2_journal_add_journal_head(bh); 771470decc6SDave Kleikamp int rc; 772470decc6SDave Kleikamp 773470decc6SDave Kleikamp /* We do not want to get caught playing with fields which the 774470decc6SDave Kleikamp * log thread also manipulates. Make sure that the buffer 775470decc6SDave Kleikamp * completes any outstanding IO before proceeding. */ 776470decc6SDave Kleikamp rc = do_get_write_access(handle, jh, 0); 777f7f4bccbSMingming Cao jbd2_journal_put_journal_head(jh); 778470decc6SDave Kleikamp return rc; 779470decc6SDave Kleikamp } 780470decc6SDave Kleikamp 781470decc6SDave Kleikamp 782470decc6SDave Kleikamp /* 783470decc6SDave Kleikamp * When the user wants to journal a newly created buffer_head 784470decc6SDave Kleikamp * (ie. getblk() returned a new buffer and we are going to populate it 785470decc6SDave Kleikamp * manually rather than reading off disk), then we need to keep the 786470decc6SDave Kleikamp * buffer_head locked until it has been completely filled with new 787470decc6SDave Kleikamp * data. In this case, we should be able to make the assertion that 788470decc6SDave Kleikamp * the bh is not already part of an existing transaction. 789470decc6SDave Kleikamp * 790470decc6SDave Kleikamp * The buffer should already be locked by the caller by this point. 791470decc6SDave Kleikamp * There is no lock ranking violation: it was a newly created, 792470decc6SDave Kleikamp * unlocked buffer beforehand. */ 793470decc6SDave Kleikamp 794470decc6SDave Kleikamp /** 795f7f4bccbSMingming Cao * int jbd2_journal_get_create_access () - notify intent to use newly created bh 796470decc6SDave Kleikamp * @handle: transaction to new buffer to 797470decc6SDave Kleikamp * @bh: new buffer. 798470decc6SDave Kleikamp * 799470decc6SDave Kleikamp * Call this if you create a new bh. 800470decc6SDave Kleikamp */ 801f7f4bccbSMingming Cao int jbd2_journal_get_create_access(handle_t *handle, struct buffer_head *bh) 802470decc6SDave Kleikamp { 803470decc6SDave Kleikamp transaction_t *transaction = handle->h_transaction; 804470decc6SDave Kleikamp journal_t *journal = transaction->t_journal; 805f7f4bccbSMingming Cao struct journal_head *jh = jbd2_journal_add_journal_head(bh); 806470decc6SDave Kleikamp int err; 807470decc6SDave Kleikamp 808470decc6SDave Kleikamp jbd_debug(5, "journal_head %p\n", jh); 809470decc6SDave Kleikamp err = -EROFS; 810470decc6SDave Kleikamp if (is_handle_aborted(handle)) 811470decc6SDave Kleikamp goto out; 812470decc6SDave Kleikamp err = 0; 813470decc6SDave Kleikamp 814470decc6SDave Kleikamp JBUFFER_TRACE(jh, "entry"); 815470decc6SDave Kleikamp /* 816470decc6SDave Kleikamp * The buffer may already belong to this transaction due to pre-zeroing 817470decc6SDave Kleikamp * in the filesystem's new_block code. It may also be on the previous, 818470decc6SDave Kleikamp * committing transaction's lists, but it HAS to be in Forget state in 819470decc6SDave Kleikamp * that case: the transaction must have deleted the buffer for it to be 820470decc6SDave Kleikamp * reused here. 821470decc6SDave Kleikamp */ 822470decc6SDave Kleikamp jbd_lock_bh_state(bh); 823470decc6SDave Kleikamp spin_lock(&journal->j_list_lock); 824470decc6SDave Kleikamp J_ASSERT_JH(jh, (jh->b_transaction == transaction || 825470decc6SDave Kleikamp jh->b_transaction == NULL || 826470decc6SDave Kleikamp (jh->b_transaction == journal->j_committing_transaction && 827470decc6SDave Kleikamp jh->b_jlist == BJ_Forget))); 828470decc6SDave Kleikamp 829470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_next_transaction == NULL); 830470decc6SDave Kleikamp J_ASSERT_JH(jh, buffer_locked(jh2bh(jh))); 831470decc6SDave Kleikamp 832470decc6SDave Kleikamp if (jh->b_transaction == NULL) { 833f91d1d04SJan Kara /* 834f91d1d04SJan Kara * Previous jbd2_journal_forget() could have left the buffer 835f91d1d04SJan Kara * with jbddirty bit set because it was being committed. When 836f91d1d04SJan Kara * the commit finished, we've filed the buffer for 837f91d1d04SJan Kara * checkpointing and marked it dirty. Now we are reallocating 838f91d1d04SJan Kara * the buffer so the transaction freeing it must have 839f91d1d04SJan Kara * committed and so it's safe to clear the dirty bit. 840f91d1d04SJan Kara */ 841f91d1d04SJan Kara clear_buffer_dirty(jh2bh(jh)); 842470decc6SDave Kleikamp jh->b_transaction = transaction; 8439fc7c63aSJosef Bacik 8449fc7c63aSJosef Bacik /* first access by this transaction */ 8459fc7c63aSJosef Bacik jh->b_modified = 0; 8469fc7c63aSJosef Bacik 847470decc6SDave Kleikamp JBUFFER_TRACE(jh, "file as BJ_Reserved"); 848f7f4bccbSMingming Cao __jbd2_journal_file_buffer(jh, transaction, BJ_Reserved); 849470decc6SDave Kleikamp } else if (jh->b_transaction == journal->j_committing_transaction) { 8509fc7c63aSJosef Bacik /* first access by this transaction */ 8519fc7c63aSJosef Bacik jh->b_modified = 0; 8529fc7c63aSJosef Bacik 853470decc6SDave Kleikamp JBUFFER_TRACE(jh, "set next transaction"); 854470decc6SDave Kleikamp jh->b_next_transaction = transaction; 855470decc6SDave Kleikamp } 856470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 857470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 858470decc6SDave Kleikamp 859470decc6SDave Kleikamp /* 860470decc6SDave Kleikamp * akpm: I added this. ext3_alloc_branch can pick up new indirect 861470decc6SDave Kleikamp * blocks which contain freed but then revoked metadata. We need 862470decc6SDave Kleikamp * to cancel the revoke in case we end up freeing it yet again 863470decc6SDave Kleikamp * and the reallocating as data - this would cause a second revoke, 864470decc6SDave Kleikamp * which hits an assertion error. 865470decc6SDave Kleikamp */ 866470decc6SDave Kleikamp JBUFFER_TRACE(jh, "cancelling revoke"); 867f7f4bccbSMingming Cao jbd2_journal_cancel_revoke(handle, jh); 868f7f4bccbSMingming Cao jbd2_journal_put_journal_head(jh); 869470decc6SDave Kleikamp out: 870470decc6SDave Kleikamp return err; 871470decc6SDave Kleikamp } 872470decc6SDave Kleikamp 873470decc6SDave Kleikamp /** 874f7f4bccbSMingming Cao * int jbd2_journal_get_undo_access() - Notify intent to modify metadata with 875470decc6SDave Kleikamp * non-rewindable consequences 876470decc6SDave Kleikamp * @handle: transaction 877470decc6SDave Kleikamp * @bh: buffer to undo 878470decc6SDave Kleikamp * @credits: store the number of taken credits here (if not NULL) 879470decc6SDave Kleikamp * 880470decc6SDave Kleikamp * Sometimes there is a need to distinguish between metadata which has 881470decc6SDave Kleikamp * been committed to disk and that which has not. The ext3fs code uses 882470decc6SDave Kleikamp * this for freeing and allocating space, we have to make sure that we 883470decc6SDave Kleikamp * do not reuse freed space until the deallocation has been committed, 884470decc6SDave Kleikamp * since if we overwrote that space we would make the delete 885470decc6SDave Kleikamp * un-rewindable in case of a crash. 886470decc6SDave Kleikamp * 887f7f4bccbSMingming Cao * To deal with that, jbd2_journal_get_undo_access requests write access to a 888470decc6SDave Kleikamp * buffer for parts of non-rewindable operations such as delete 889470decc6SDave Kleikamp * operations on the bitmaps. The journaling code must keep a copy of 890470decc6SDave Kleikamp * the buffer's contents prior to the undo_access call until such time 891470decc6SDave Kleikamp * as we know that the buffer has definitely been committed to disk. 892470decc6SDave Kleikamp * 893470decc6SDave Kleikamp * We never need to know which transaction the committed data is part 894470decc6SDave Kleikamp * of, buffers touched here are guaranteed to be dirtied later and so 895470decc6SDave Kleikamp * will be committed to a new transaction in due course, at which point 896470decc6SDave Kleikamp * we can discard the old committed data pointer. 897470decc6SDave Kleikamp * 898470decc6SDave Kleikamp * Returns error number or 0 on success. 899470decc6SDave Kleikamp */ 900f7f4bccbSMingming Cao int jbd2_journal_get_undo_access(handle_t *handle, struct buffer_head *bh) 901470decc6SDave Kleikamp { 902470decc6SDave Kleikamp int err; 903f7f4bccbSMingming Cao struct journal_head *jh = jbd2_journal_add_journal_head(bh); 904470decc6SDave Kleikamp char *committed_data = NULL; 905470decc6SDave Kleikamp 906470decc6SDave Kleikamp JBUFFER_TRACE(jh, "entry"); 907470decc6SDave Kleikamp 908470decc6SDave Kleikamp /* 909470decc6SDave Kleikamp * Do this first --- it can drop the journal lock, so we want to 910470decc6SDave Kleikamp * make sure that obtaining the committed_data is done 911470decc6SDave Kleikamp * atomically wrt. completion of any outstanding commits. 912470decc6SDave Kleikamp */ 913470decc6SDave Kleikamp err = do_get_write_access(handle, jh, 1); 914470decc6SDave Kleikamp if (err) 915470decc6SDave Kleikamp goto out; 916470decc6SDave Kleikamp 917470decc6SDave Kleikamp repeat: 918470decc6SDave Kleikamp if (!jh->b_committed_data) { 919af1e76d6SMingming Cao committed_data = jbd2_alloc(jh2bh(jh)->b_size, GFP_NOFS); 920470decc6SDave Kleikamp if (!committed_data) { 921470decc6SDave Kleikamp printk(KERN_EMERG "%s: No memory for committed data\n", 922329d291fSHarvey Harrison __func__); 923470decc6SDave Kleikamp err = -ENOMEM; 924470decc6SDave Kleikamp goto out; 925470decc6SDave Kleikamp } 926470decc6SDave Kleikamp } 927470decc6SDave Kleikamp 928470decc6SDave Kleikamp jbd_lock_bh_state(bh); 929470decc6SDave Kleikamp if (!jh->b_committed_data) { 930470decc6SDave Kleikamp /* Copy out the current buffer contents into the 931470decc6SDave Kleikamp * preserved, committed copy. */ 932470decc6SDave Kleikamp JBUFFER_TRACE(jh, "generate b_committed data"); 933470decc6SDave Kleikamp if (!committed_data) { 934470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 935470decc6SDave Kleikamp goto repeat; 936470decc6SDave Kleikamp } 937470decc6SDave Kleikamp 938470decc6SDave Kleikamp jh->b_committed_data = committed_data; 939470decc6SDave Kleikamp committed_data = NULL; 940470decc6SDave Kleikamp memcpy(jh->b_committed_data, bh->b_data, bh->b_size); 941470decc6SDave Kleikamp } 942470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 943470decc6SDave Kleikamp out: 944f7f4bccbSMingming Cao jbd2_journal_put_journal_head(jh); 945470decc6SDave Kleikamp if (unlikely(committed_data)) 946af1e76d6SMingming Cao jbd2_free(committed_data, bh->b_size); 947470decc6SDave Kleikamp return err; 948470decc6SDave Kleikamp } 949470decc6SDave Kleikamp 950470decc6SDave Kleikamp /** 951e06c8227SJoel Becker * void jbd2_journal_set_triggers() - Add triggers for commit writeout 952e06c8227SJoel Becker * @bh: buffer to trigger on 953e06c8227SJoel Becker * @type: struct jbd2_buffer_trigger_type containing the trigger(s). 954e06c8227SJoel Becker * 955e06c8227SJoel Becker * Set any triggers on this journal_head. This is always safe, because 956e06c8227SJoel Becker * triggers for a committing buffer will be saved off, and triggers for 957e06c8227SJoel Becker * a running transaction will match the buffer in that transaction. 958e06c8227SJoel Becker * 959e06c8227SJoel Becker * Call with NULL to clear the triggers. 960e06c8227SJoel Becker */ 961e06c8227SJoel Becker void jbd2_journal_set_triggers(struct buffer_head *bh, 962e06c8227SJoel Becker struct jbd2_buffer_trigger_type *type) 963e06c8227SJoel Becker { 964e06c8227SJoel Becker struct journal_head *jh = bh2jh(bh); 965e06c8227SJoel Becker 966e06c8227SJoel Becker jh->b_triggers = type; 967e06c8227SJoel Becker } 968e06c8227SJoel Becker 96913ceef09SJan Kara void jbd2_buffer_frozen_trigger(struct journal_head *jh, void *mapped_data, 970e06c8227SJoel Becker struct jbd2_buffer_trigger_type *triggers) 971e06c8227SJoel Becker { 972e06c8227SJoel Becker struct buffer_head *bh = jh2bh(jh); 973e06c8227SJoel Becker 97413ceef09SJan Kara if (!triggers || !triggers->t_frozen) 975e06c8227SJoel Becker return; 976e06c8227SJoel Becker 97713ceef09SJan Kara triggers->t_frozen(triggers, bh, mapped_data, bh->b_size); 978e06c8227SJoel Becker } 979e06c8227SJoel Becker 980e06c8227SJoel Becker void jbd2_buffer_abort_trigger(struct journal_head *jh, 981e06c8227SJoel Becker struct jbd2_buffer_trigger_type *triggers) 982e06c8227SJoel Becker { 983e06c8227SJoel Becker if (!triggers || !triggers->t_abort) 984e06c8227SJoel Becker return; 985e06c8227SJoel Becker 986e06c8227SJoel Becker triggers->t_abort(triggers, jh2bh(jh)); 987e06c8227SJoel Becker } 988e06c8227SJoel Becker 989e06c8227SJoel Becker 990e06c8227SJoel Becker 991e06c8227SJoel Becker /** 992f7f4bccbSMingming Cao * int jbd2_journal_dirty_metadata() - mark a buffer as containing dirty metadata 993470decc6SDave Kleikamp * @handle: transaction to add buffer to. 994470decc6SDave Kleikamp * @bh: buffer to mark 995470decc6SDave Kleikamp * 996470decc6SDave Kleikamp * mark dirty metadata which needs to be journaled as part of the current 997470decc6SDave Kleikamp * transaction. 998470decc6SDave Kleikamp * 999470decc6SDave Kleikamp * The buffer is placed on the transaction's metadata list and is marked 1000470decc6SDave Kleikamp * as belonging to the transaction. 1001470decc6SDave Kleikamp * 1002470decc6SDave Kleikamp * Returns error number or 0 on success. 1003470decc6SDave Kleikamp * 1004470decc6SDave Kleikamp * Special care needs to be taken if the buffer already belongs to the 1005470decc6SDave Kleikamp * current committing transaction (in which case we should have frozen 1006470decc6SDave Kleikamp * data present for that commit). In that case, we don't relink the 1007470decc6SDave Kleikamp * buffer: that only gets done when the old transaction finally 1008470decc6SDave Kleikamp * completes its commit. 1009470decc6SDave Kleikamp */ 1010f7f4bccbSMingming Cao int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh) 1011470decc6SDave Kleikamp { 1012470decc6SDave Kleikamp transaction_t *transaction = handle->h_transaction; 1013470decc6SDave Kleikamp journal_t *journal = transaction->t_journal; 1014470decc6SDave Kleikamp struct journal_head *jh = bh2jh(bh); 1015470decc6SDave Kleikamp 1016470decc6SDave Kleikamp jbd_debug(5, "journal_head %p\n", jh); 1017470decc6SDave Kleikamp JBUFFER_TRACE(jh, "entry"); 1018470decc6SDave Kleikamp if (is_handle_aborted(handle)) 1019470decc6SDave Kleikamp goto out; 1020470decc6SDave Kleikamp 1021470decc6SDave Kleikamp jbd_lock_bh_state(bh); 1022470decc6SDave Kleikamp 1023470decc6SDave Kleikamp if (jh->b_modified == 0) { 1024470decc6SDave Kleikamp /* 1025470decc6SDave Kleikamp * This buffer's got modified and becoming part 1026470decc6SDave Kleikamp * of the transaction. This needs to be done 1027470decc6SDave Kleikamp * once a transaction -bzzz 1028470decc6SDave Kleikamp */ 1029470decc6SDave Kleikamp jh->b_modified = 1; 1030470decc6SDave Kleikamp J_ASSERT_JH(jh, handle->h_buffer_credits > 0); 1031470decc6SDave Kleikamp handle->h_buffer_credits--; 1032470decc6SDave Kleikamp } 1033470decc6SDave Kleikamp 1034470decc6SDave Kleikamp /* 1035470decc6SDave Kleikamp * fastpath, to avoid expensive locking. If this buffer is already 1036470decc6SDave Kleikamp * on the running transaction's metadata list there is nothing to do. 1037470decc6SDave Kleikamp * Nobody can take it off again because there is a handle open. 1038470decc6SDave Kleikamp * I _think_ we're OK here with SMP barriers - a mistaken decision will 1039470decc6SDave Kleikamp * result in this test being false, so we go in and take the locks. 1040470decc6SDave Kleikamp */ 1041470decc6SDave Kleikamp if (jh->b_transaction == transaction && jh->b_jlist == BJ_Metadata) { 1042470decc6SDave Kleikamp JBUFFER_TRACE(jh, "fastpath"); 1043470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_transaction == 1044470decc6SDave Kleikamp journal->j_running_transaction); 1045470decc6SDave Kleikamp goto out_unlock_bh; 1046470decc6SDave Kleikamp } 1047470decc6SDave Kleikamp 1048470decc6SDave Kleikamp set_buffer_jbddirty(bh); 1049470decc6SDave Kleikamp 1050470decc6SDave Kleikamp /* 1051470decc6SDave Kleikamp * Metadata already on the current transaction list doesn't 1052470decc6SDave Kleikamp * need to be filed. Metadata on another transaction's list must 1053470decc6SDave Kleikamp * be committing, and will be refiled once the commit completes: 1054470decc6SDave Kleikamp * leave it alone for now. 1055470decc6SDave Kleikamp */ 1056470decc6SDave Kleikamp if (jh->b_transaction != transaction) { 1057470decc6SDave Kleikamp JBUFFER_TRACE(jh, "already on other transaction"); 1058470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_transaction == 1059470decc6SDave Kleikamp journal->j_committing_transaction); 1060470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_next_transaction == transaction); 1061470decc6SDave Kleikamp /* And this case is illegal: we can't reuse another 1062470decc6SDave Kleikamp * transaction's data buffer, ever. */ 1063470decc6SDave Kleikamp goto out_unlock_bh; 1064470decc6SDave Kleikamp } 1065470decc6SDave Kleikamp 1066470decc6SDave Kleikamp /* That test should have eliminated the following case: */ 10674019191bSMingming Cao J_ASSERT_JH(jh, jh->b_frozen_data == NULL); 1068470decc6SDave Kleikamp 1069470decc6SDave Kleikamp JBUFFER_TRACE(jh, "file as BJ_Metadata"); 1070470decc6SDave Kleikamp spin_lock(&journal->j_list_lock); 1071f7f4bccbSMingming Cao __jbd2_journal_file_buffer(jh, handle->h_transaction, BJ_Metadata); 1072470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 1073470decc6SDave Kleikamp out_unlock_bh: 1074470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 1075470decc6SDave Kleikamp out: 1076470decc6SDave Kleikamp JBUFFER_TRACE(jh, "exit"); 1077470decc6SDave Kleikamp return 0; 1078470decc6SDave Kleikamp } 1079470decc6SDave Kleikamp 1080470decc6SDave Kleikamp /* 1081f7f4bccbSMingming Cao * jbd2_journal_release_buffer: undo a get_write_access without any buffer 1082470decc6SDave Kleikamp * updates, if the update decided in the end that it didn't need access. 1083470decc6SDave Kleikamp * 1084470decc6SDave Kleikamp */ 1085470decc6SDave Kleikamp void 1086f7f4bccbSMingming Cao jbd2_journal_release_buffer(handle_t *handle, struct buffer_head *bh) 1087470decc6SDave Kleikamp { 1088470decc6SDave Kleikamp BUFFER_TRACE(bh, "entry"); 1089470decc6SDave Kleikamp } 1090470decc6SDave Kleikamp 1091470decc6SDave Kleikamp /** 1092f7f4bccbSMingming Cao * void jbd2_journal_forget() - bforget() for potentially-journaled buffers. 1093470decc6SDave Kleikamp * @handle: transaction handle 1094470decc6SDave Kleikamp * @bh: bh to 'forget' 1095470decc6SDave Kleikamp * 1096470decc6SDave Kleikamp * We can only do the bforget if there are no commits pending against the 1097470decc6SDave Kleikamp * buffer. If the buffer is dirty in the current running transaction we 1098470decc6SDave Kleikamp * can safely unlink it. 1099470decc6SDave Kleikamp * 1100470decc6SDave Kleikamp * bh may not be a journalled buffer at all - it may be a non-JBD 1101470decc6SDave Kleikamp * buffer which came off the hashtable. Check for this. 1102470decc6SDave Kleikamp * 1103470decc6SDave Kleikamp * Decrements bh->b_count by one. 1104470decc6SDave Kleikamp * 1105470decc6SDave Kleikamp * Allow this call even if the handle has aborted --- it may be part of 1106470decc6SDave Kleikamp * the caller's cleanup after an abort. 1107470decc6SDave Kleikamp */ 1108f7f4bccbSMingming Cao int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh) 1109470decc6SDave Kleikamp { 1110470decc6SDave Kleikamp transaction_t *transaction = handle->h_transaction; 1111470decc6SDave Kleikamp journal_t *journal = transaction->t_journal; 1112470decc6SDave Kleikamp struct journal_head *jh; 1113470decc6SDave Kleikamp int drop_reserve = 0; 1114470decc6SDave Kleikamp int err = 0; 11151dfc3220SJosef Bacik int was_modified = 0; 1116470decc6SDave Kleikamp 1117470decc6SDave Kleikamp BUFFER_TRACE(bh, "entry"); 1118470decc6SDave Kleikamp 1119470decc6SDave Kleikamp jbd_lock_bh_state(bh); 1120470decc6SDave Kleikamp spin_lock(&journal->j_list_lock); 1121470decc6SDave Kleikamp 1122470decc6SDave Kleikamp if (!buffer_jbd(bh)) 1123470decc6SDave Kleikamp goto not_jbd; 1124470decc6SDave Kleikamp jh = bh2jh(bh); 1125470decc6SDave Kleikamp 1126470decc6SDave Kleikamp /* Critical error: attempting to delete a bitmap buffer, maybe? 1127470decc6SDave Kleikamp * Don't do any jbd operations, and return an error. */ 1128470decc6SDave Kleikamp if (!J_EXPECT_JH(jh, !jh->b_committed_data, 1129470decc6SDave Kleikamp "inconsistent data on disk")) { 1130470decc6SDave Kleikamp err = -EIO; 1131470decc6SDave Kleikamp goto not_jbd; 1132470decc6SDave Kleikamp } 1133470decc6SDave Kleikamp 11341dfc3220SJosef Bacik /* keep track of wether or not this transaction modified us */ 11351dfc3220SJosef Bacik was_modified = jh->b_modified; 11361dfc3220SJosef Bacik 1137470decc6SDave Kleikamp /* 1138470decc6SDave Kleikamp * The buffer's going from the transaction, we must drop 1139470decc6SDave Kleikamp * all references -bzzz 1140470decc6SDave Kleikamp */ 1141470decc6SDave Kleikamp jh->b_modified = 0; 1142470decc6SDave Kleikamp 1143470decc6SDave Kleikamp if (jh->b_transaction == handle->h_transaction) { 1144470decc6SDave Kleikamp J_ASSERT_JH(jh, !jh->b_frozen_data); 1145470decc6SDave Kleikamp 1146470decc6SDave Kleikamp /* If we are forgetting a buffer which is already part 1147470decc6SDave Kleikamp * of this transaction, then we can just drop it from 1148470decc6SDave Kleikamp * the transaction immediately. */ 1149470decc6SDave Kleikamp clear_buffer_dirty(bh); 1150470decc6SDave Kleikamp clear_buffer_jbddirty(bh); 1151470decc6SDave Kleikamp 1152470decc6SDave Kleikamp JBUFFER_TRACE(jh, "belongs to current transaction: unfile"); 1153470decc6SDave Kleikamp 11541dfc3220SJosef Bacik /* 11551dfc3220SJosef Bacik * we only want to drop a reference if this transaction 11561dfc3220SJosef Bacik * modified the buffer 11571dfc3220SJosef Bacik */ 11581dfc3220SJosef Bacik if (was_modified) 1159470decc6SDave Kleikamp drop_reserve = 1; 1160470decc6SDave Kleikamp 1161470decc6SDave Kleikamp /* 1162470decc6SDave Kleikamp * We are no longer going to journal this buffer. 1163470decc6SDave Kleikamp * However, the commit of this transaction is still 1164470decc6SDave Kleikamp * important to the buffer: the delete that we are now 1165470decc6SDave Kleikamp * processing might obsolete an old log entry, so by 1166470decc6SDave Kleikamp * committing, we can satisfy the buffer's checkpoint. 1167470decc6SDave Kleikamp * 1168470decc6SDave Kleikamp * So, if we have a checkpoint on the buffer, we should 1169470decc6SDave Kleikamp * now refile the buffer on our BJ_Forget list so that 1170470decc6SDave Kleikamp * we know to remove the checkpoint after we commit. 1171470decc6SDave Kleikamp */ 1172470decc6SDave Kleikamp 1173470decc6SDave Kleikamp if (jh->b_cp_transaction) { 1174f7f4bccbSMingming Cao __jbd2_journal_temp_unlink_buffer(jh); 1175f7f4bccbSMingming Cao __jbd2_journal_file_buffer(jh, transaction, BJ_Forget); 1176470decc6SDave Kleikamp } else { 1177f7f4bccbSMingming Cao __jbd2_journal_unfile_buffer(jh); 1178f7f4bccbSMingming Cao jbd2_journal_remove_journal_head(bh); 1179470decc6SDave Kleikamp __brelse(bh); 1180470decc6SDave Kleikamp if (!buffer_jbd(bh)) { 1181470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 1182470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 1183470decc6SDave Kleikamp __bforget(bh); 1184470decc6SDave Kleikamp goto drop; 1185470decc6SDave Kleikamp } 1186470decc6SDave Kleikamp } 1187470decc6SDave Kleikamp } else if (jh->b_transaction) { 1188470decc6SDave Kleikamp J_ASSERT_JH(jh, (jh->b_transaction == 1189470decc6SDave Kleikamp journal->j_committing_transaction)); 1190470decc6SDave Kleikamp /* However, if the buffer is still owned by a prior 1191470decc6SDave Kleikamp * (committing) transaction, we can't drop it yet... */ 1192470decc6SDave Kleikamp JBUFFER_TRACE(jh, "belongs to older transaction"); 1193470decc6SDave Kleikamp /* ... but we CAN drop it from the new transaction if we 1194470decc6SDave Kleikamp * have also modified it since the original commit. */ 1195470decc6SDave Kleikamp 1196470decc6SDave Kleikamp if (jh->b_next_transaction) { 1197470decc6SDave Kleikamp J_ASSERT(jh->b_next_transaction == transaction); 1198470decc6SDave Kleikamp jh->b_next_transaction = NULL; 11991dfc3220SJosef Bacik 12001dfc3220SJosef Bacik /* 12011dfc3220SJosef Bacik * only drop a reference if this transaction modified 12021dfc3220SJosef Bacik * the buffer 12031dfc3220SJosef Bacik */ 12041dfc3220SJosef Bacik if (was_modified) 1205470decc6SDave Kleikamp drop_reserve = 1; 1206470decc6SDave Kleikamp } 1207470decc6SDave Kleikamp } 1208470decc6SDave Kleikamp 1209470decc6SDave Kleikamp not_jbd: 1210470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 1211470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 1212470decc6SDave Kleikamp __brelse(bh); 1213470decc6SDave Kleikamp drop: 1214470decc6SDave Kleikamp if (drop_reserve) { 1215470decc6SDave Kleikamp /* no need to reserve log space for this block -bzzz */ 1216470decc6SDave Kleikamp handle->h_buffer_credits++; 1217470decc6SDave Kleikamp } 1218470decc6SDave Kleikamp return err; 1219470decc6SDave Kleikamp } 1220470decc6SDave Kleikamp 1221470decc6SDave Kleikamp /** 1222f7f4bccbSMingming Cao * int jbd2_journal_stop() - complete a transaction 1223470decc6SDave Kleikamp * @handle: tranaction to complete. 1224470decc6SDave Kleikamp * 1225470decc6SDave Kleikamp * All done for a particular handle. 1226470decc6SDave Kleikamp * 1227470decc6SDave Kleikamp * There is not much action needed here. We just return any remaining 1228470decc6SDave Kleikamp * buffer credits to the transaction and remove the handle. The only 1229470decc6SDave Kleikamp * complication is that we need to start a commit operation if the 1230470decc6SDave Kleikamp * filesystem is marked for synchronous update. 1231470decc6SDave Kleikamp * 1232f7f4bccbSMingming Cao * jbd2_journal_stop itself will not usually return an error, but it may 1233470decc6SDave Kleikamp * do so in unusual circumstances. In particular, expect it to 1234f7f4bccbSMingming Cao * return -EIO if a jbd2_journal_abort has been executed since the 1235470decc6SDave Kleikamp * transaction began. 1236470decc6SDave Kleikamp */ 1237f7f4bccbSMingming Cao int jbd2_journal_stop(handle_t *handle) 1238470decc6SDave Kleikamp { 1239470decc6SDave Kleikamp transaction_t *transaction = handle->h_transaction; 1240470decc6SDave Kleikamp journal_t *journal = transaction->t_journal; 1241e07f7183SJosef Bacik int err; 1242470decc6SDave Kleikamp pid_t pid; 1243470decc6SDave Kleikamp 1244470decc6SDave Kleikamp J_ASSERT(journal_current_handle() == handle); 1245470decc6SDave Kleikamp 1246470decc6SDave Kleikamp if (is_handle_aborted(handle)) 1247470decc6SDave Kleikamp err = -EIO; 12483e2a532bSOGAWA Hirofumi else { 12493e2a532bSOGAWA Hirofumi J_ASSERT(transaction->t_updates > 0); 1250470decc6SDave Kleikamp err = 0; 12513e2a532bSOGAWA Hirofumi } 1252470decc6SDave Kleikamp 1253470decc6SDave Kleikamp if (--handle->h_ref > 0) { 1254470decc6SDave Kleikamp jbd_debug(4, "h_ref %d -> %d\n", handle->h_ref + 1, 1255470decc6SDave Kleikamp handle->h_ref); 1256470decc6SDave Kleikamp return err; 1257470decc6SDave Kleikamp } 1258470decc6SDave Kleikamp 1259470decc6SDave Kleikamp jbd_debug(4, "Handle %p going down\n", handle); 1260470decc6SDave Kleikamp 1261470decc6SDave Kleikamp /* 1262470decc6SDave Kleikamp * Implement synchronous transaction batching. If the handle 1263470decc6SDave Kleikamp * was synchronous, don't force a commit immediately. Let's 1264e07f7183SJosef Bacik * yield and let another thread piggyback onto this 1265e07f7183SJosef Bacik * transaction. Keep doing that while new threads continue to 1266e07f7183SJosef Bacik * arrive. It doesn't cost much - we're about to run a commit 1267e07f7183SJosef Bacik * and sleep on IO anyway. Speeds up many-threaded, many-dir 1268e07f7183SJosef Bacik * operations by 30x or more... 1269470decc6SDave Kleikamp * 1270e07f7183SJosef Bacik * We try and optimize the sleep time against what the 1271e07f7183SJosef Bacik * underlying disk can do, instead of having a static sleep 1272e07f7183SJosef Bacik * time. This is useful for the case where our storage is so 1273e07f7183SJosef Bacik * fast that it is more optimal to go ahead and force a flush 1274e07f7183SJosef Bacik * and wait for the transaction to be committed than it is to 1275e07f7183SJosef Bacik * wait for an arbitrary amount of time for new writers to 1276e07f7183SJosef Bacik * join the transaction. We achieve this by measuring how 1277e07f7183SJosef Bacik * long it takes to commit a transaction, and compare it with 1278e07f7183SJosef Bacik * how long this transaction has been running, and if run time 1279e07f7183SJosef Bacik * < commit time then we sleep for the delta and commit. This 1280e07f7183SJosef Bacik * greatly helps super fast disks that would see slowdowns as 1281e07f7183SJosef Bacik * more threads started doing fsyncs. 1282e07f7183SJosef Bacik * 1283e07f7183SJosef Bacik * But don't do this if this process was the most recent one 1284e07f7183SJosef Bacik * to perform a synchronous write. We do this to detect the 1285e07f7183SJosef Bacik * case where a single process is doing a stream of sync 1286e07f7183SJosef Bacik * writes. No point in waiting for joiners in that case. 1287470decc6SDave Kleikamp */ 1288470decc6SDave Kleikamp pid = current->pid; 1289470decc6SDave Kleikamp if (handle->h_sync && journal->j_last_sync_writer != pid) { 1290e07f7183SJosef Bacik u64 commit_time, trans_time; 1291e07f7183SJosef Bacik 1292470decc6SDave Kleikamp journal->j_last_sync_writer = pid; 1293e07f7183SJosef Bacik 1294e07f7183SJosef Bacik spin_lock(&journal->j_state_lock); 1295e07f7183SJosef Bacik commit_time = journal->j_average_commit_time; 1296e07f7183SJosef Bacik spin_unlock(&journal->j_state_lock); 1297e07f7183SJosef Bacik 1298e07f7183SJosef Bacik trans_time = ktime_to_ns(ktime_sub(ktime_get(), 1299e07f7183SJosef Bacik transaction->t_start_time)); 1300e07f7183SJosef Bacik 130130773840STheodore Ts'o commit_time = max_t(u64, commit_time, 130230773840STheodore Ts'o 1000*journal->j_min_batch_time); 1303e07f7183SJosef Bacik commit_time = min_t(u64, commit_time, 130430773840STheodore Ts'o 1000*journal->j_max_batch_time); 1305e07f7183SJosef Bacik 1306e07f7183SJosef Bacik if (trans_time < commit_time) { 1307e07f7183SJosef Bacik ktime_t expires = ktime_add_ns(ktime_get(), 1308e07f7183SJosef Bacik commit_time); 1309e07f7183SJosef Bacik set_current_state(TASK_UNINTERRUPTIBLE); 1310e07f7183SJosef Bacik schedule_hrtimeout(&expires, HRTIMER_MODE_ABS); 1311e07f7183SJosef Bacik } 1312470decc6SDave Kleikamp } 1313470decc6SDave Kleikamp 13147058548cSTheodore Ts'o if (handle->h_sync) 13157058548cSTheodore Ts'o transaction->t_synchronous_commit = 1; 1316470decc6SDave Kleikamp current->journal_info = NULL; 1317470decc6SDave Kleikamp spin_lock(&transaction->t_handle_lock); 1318470decc6SDave Kleikamp transaction->t_outstanding_credits -= handle->h_buffer_credits; 1319470decc6SDave Kleikamp transaction->t_updates--; 1320470decc6SDave Kleikamp if (!transaction->t_updates) { 1321470decc6SDave Kleikamp wake_up(&journal->j_wait_updates); 1322470decc6SDave Kleikamp if (journal->j_barrier_count) 1323470decc6SDave Kleikamp wake_up(&journal->j_wait_transaction_locked); 1324470decc6SDave Kleikamp } 1325470decc6SDave Kleikamp 1326470decc6SDave Kleikamp /* 1327470decc6SDave Kleikamp * If the handle is marked SYNC, we need to set another commit 1328470decc6SDave Kleikamp * going! We also want to force a commit if the current 1329470decc6SDave Kleikamp * transaction is occupying too much of the log, or if the 1330470decc6SDave Kleikamp * transaction is too old now. 1331470decc6SDave Kleikamp */ 1332470decc6SDave Kleikamp if (handle->h_sync || 1333470decc6SDave Kleikamp transaction->t_outstanding_credits > 1334470decc6SDave Kleikamp journal->j_max_transaction_buffers || 1335470decc6SDave Kleikamp time_after_eq(jiffies, transaction->t_expires)) { 1336470decc6SDave Kleikamp /* Do this even for aborted journals: an abort still 1337470decc6SDave Kleikamp * completes the commit thread, it just doesn't write 1338470decc6SDave Kleikamp * anything to disk. */ 1339470decc6SDave Kleikamp tid_t tid = transaction->t_tid; 1340470decc6SDave Kleikamp 1341470decc6SDave Kleikamp spin_unlock(&transaction->t_handle_lock); 1342470decc6SDave Kleikamp jbd_debug(2, "transaction too old, requesting commit for " 1343470decc6SDave Kleikamp "handle %p\n", handle); 1344470decc6SDave Kleikamp /* This is non-blocking */ 1345c35a56a0STheodore Ts'o jbd2_log_start_commit(journal, transaction->t_tid); 1346470decc6SDave Kleikamp 1347470decc6SDave Kleikamp /* 1348f7f4bccbSMingming Cao * Special case: JBD2_SYNC synchronous updates require us 1349470decc6SDave Kleikamp * to wait for the commit to complete. 1350470decc6SDave Kleikamp */ 1351470decc6SDave Kleikamp if (handle->h_sync && !(current->flags & PF_MEMALLOC)) 1352f7f4bccbSMingming Cao err = jbd2_log_wait_commit(journal, tid); 1353470decc6SDave Kleikamp } else { 1354470decc6SDave Kleikamp spin_unlock(&transaction->t_handle_lock); 1355470decc6SDave Kleikamp } 1356470decc6SDave Kleikamp 13573295f0efSIngo Molnar lock_map_release(&handle->h_lockdep_map); 13587b751066SMingming Cao 1359af1e76d6SMingming Cao jbd2_free_handle(handle); 1360470decc6SDave Kleikamp return err; 1361470decc6SDave Kleikamp } 1362470decc6SDave Kleikamp 13635648ba5bSRandy Dunlap /** 13645648ba5bSRandy Dunlap * int jbd2_journal_force_commit() - force any uncommitted transactions 1365470decc6SDave Kleikamp * @journal: journal to force 1366470decc6SDave Kleikamp * 1367470decc6SDave Kleikamp * For synchronous operations: force any uncommitted transactions 1368470decc6SDave Kleikamp * to disk. May seem kludgy, but it reuses all the handle batching 1369470decc6SDave Kleikamp * code in a very simple manner. 1370470decc6SDave Kleikamp */ 1371f7f4bccbSMingming Cao int jbd2_journal_force_commit(journal_t *journal) 1372470decc6SDave Kleikamp { 1373470decc6SDave Kleikamp handle_t *handle; 1374470decc6SDave Kleikamp int ret; 1375470decc6SDave Kleikamp 1376f7f4bccbSMingming Cao handle = jbd2_journal_start(journal, 1); 1377470decc6SDave Kleikamp if (IS_ERR(handle)) { 1378470decc6SDave Kleikamp ret = PTR_ERR(handle); 1379470decc6SDave Kleikamp } else { 1380470decc6SDave Kleikamp handle->h_sync = 1; 1381f7f4bccbSMingming Cao ret = jbd2_journal_stop(handle); 1382470decc6SDave Kleikamp } 1383470decc6SDave Kleikamp return ret; 1384470decc6SDave Kleikamp } 1385470decc6SDave Kleikamp 1386470decc6SDave Kleikamp /* 1387470decc6SDave Kleikamp * 1388470decc6SDave Kleikamp * List management code snippets: various functions for manipulating the 1389470decc6SDave Kleikamp * transaction buffer lists. 1390470decc6SDave Kleikamp * 1391470decc6SDave Kleikamp */ 1392470decc6SDave Kleikamp 1393470decc6SDave Kleikamp /* 1394470decc6SDave Kleikamp * Append a buffer to a transaction list, given the transaction's list head 1395470decc6SDave Kleikamp * pointer. 1396470decc6SDave Kleikamp * 1397470decc6SDave Kleikamp * j_list_lock is held. 1398470decc6SDave Kleikamp * 1399470decc6SDave Kleikamp * jbd_lock_bh_state(jh2bh(jh)) is held. 1400470decc6SDave Kleikamp */ 1401470decc6SDave Kleikamp 1402470decc6SDave Kleikamp static inline void 1403470decc6SDave Kleikamp __blist_add_buffer(struct journal_head **list, struct journal_head *jh) 1404470decc6SDave Kleikamp { 1405470decc6SDave Kleikamp if (!*list) { 1406470decc6SDave Kleikamp jh->b_tnext = jh->b_tprev = jh; 1407470decc6SDave Kleikamp *list = jh; 1408470decc6SDave Kleikamp } else { 1409470decc6SDave Kleikamp /* Insert at the tail of the list to preserve order */ 1410470decc6SDave Kleikamp struct journal_head *first = *list, *last = first->b_tprev; 1411470decc6SDave Kleikamp jh->b_tprev = last; 1412470decc6SDave Kleikamp jh->b_tnext = first; 1413470decc6SDave Kleikamp last->b_tnext = first->b_tprev = jh; 1414470decc6SDave Kleikamp } 1415470decc6SDave Kleikamp } 1416470decc6SDave Kleikamp 1417470decc6SDave Kleikamp /* 1418470decc6SDave Kleikamp * Remove a buffer from a transaction list, given the transaction's list 1419470decc6SDave Kleikamp * head pointer. 1420470decc6SDave Kleikamp * 1421470decc6SDave Kleikamp * Called with j_list_lock held, and the journal may not be locked. 1422470decc6SDave Kleikamp * 1423470decc6SDave Kleikamp * jbd_lock_bh_state(jh2bh(jh)) is held. 1424470decc6SDave Kleikamp */ 1425470decc6SDave Kleikamp 1426470decc6SDave Kleikamp static inline void 1427470decc6SDave Kleikamp __blist_del_buffer(struct journal_head **list, struct journal_head *jh) 1428470decc6SDave Kleikamp { 1429470decc6SDave Kleikamp if (*list == jh) { 1430470decc6SDave Kleikamp *list = jh->b_tnext; 1431470decc6SDave Kleikamp if (*list == jh) 1432470decc6SDave Kleikamp *list = NULL; 1433470decc6SDave Kleikamp } 1434470decc6SDave Kleikamp jh->b_tprev->b_tnext = jh->b_tnext; 1435470decc6SDave Kleikamp jh->b_tnext->b_tprev = jh->b_tprev; 1436470decc6SDave Kleikamp } 1437470decc6SDave Kleikamp 1438470decc6SDave Kleikamp /* 1439470decc6SDave Kleikamp * Remove a buffer from the appropriate transaction list. 1440470decc6SDave Kleikamp * 1441470decc6SDave Kleikamp * Note that this function can *change* the value of 144287c89c23SJan Kara * bh->b_transaction->t_buffers, t_forget, t_iobuf_list, t_shadow_list, 144387c89c23SJan Kara * t_log_list or t_reserved_list. If the caller is holding onto a copy of one 144487c89c23SJan Kara * of these pointers, it could go bad. Generally the caller needs to re-read 144587c89c23SJan Kara * the pointer from the transaction_t. 1446470decc6SDave Kleikamp * 1447470decc6SDave Kleikamp * Called under j_list_lock. The journal may not be locked. 1448470decc6SDave Kleikamp */ 1449f7f4bccbSMingming Cao void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh) 1450470decc6SDave Kleikamp { 1451470decc6SDave Kleikamp struct journal_head **list = NULL; 1452470decc6SDave Kleikamp transaction_t *transaction; 1453470decc6SDave Kleikamp struct buffer_head *bh = jh2bh(jh); 1454470decc6SDave Kleikamp 1455470decc6SDave Kleikamp J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh)); 1456470decc6SDave Kleikamp transaction = jh->b_transaction; 1457470decc6SDave Kleikamp if (transaction) 1458470decc6SDave Kleikamp assert_spin_locked(&transaction->t_journal->j_list_lock); 1459470decc6SDave Kleikamp 1460470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_jlist < BJ_Types); 1461470decc6SDave Kleikamp if (jh->b_jlist != BJ_None) 14624019191bSMingming Cao J_ASSERT_JH(jh, transaction != NULL); 1463470decc6SDave Kleikamp 1464470decc6SDave Kleikamp switch (jh->b_jlist) { 1465470decc6SDave Kleikamp case BJ_None: 1466470decc6SDave Kleikamp return; 1467470decc6SDave Kleikamp case BJ_Metadata: 1468470decc6SDave Kleikamp transaction->t_nr_buffers--; 1469470decc6SDave Kleikamp J_ASSERT_JH(jh, transaction->t_nr_buffers >= 0); 1470470decc6SDave Kleikamp list = &transaction->t_buffers; 1471470decc6SDave Kleikamp break; 1472470decc6SDave Kleikamp case BJ_Forget: 1473470decc6SDave Kleikamp list = &transaction->t_forget; 1474470decc6SDave Kleikamp break; 1475470decc6SDave Kleikamp case BJ_IO: 1476470decc6SDave Kleikamp list = &transaction->t_iobuf_list; 1477470decc6SDave Kleikamp break; 1478470decc6SDave Kleikamp case BJ_Shadow: 1479470decc6SDave Kleikamp list = &transaction->t_shadow_list; 1480470decc6SDave Kleikamp break; 1481470decc6SDave Kleikamp case BJ_LogCtl: 1482470decc6SDave Kleikamp list = &transaction->t_log_list; 1483470decc6SDave Kleikamp break; 1484470decc6SDave Kleikamp case BJ_Reserved: 1485470decc6SDave Kleikamp list = &transaction->t_reserved_list; 1486470decc6SDave Kleikamp break; 1487470decc6SDave Kleikamp } 1488470decc6SDave Kleikamp 1489470decc6SDave Kleikamp __blist_del_buffer(list, jh); 1490470decc6SDave Kleikamp jh->b_jlist = BJ_None; 1491470decc6SDave Kleikamp if (test_clear_buffer_jbddirty(bh)) 1492470decc6SDave Kleikamp mark_buffer_dirty(bh); /* Expose it to the VM */ 1493470decc6SDave Kleikamp } 1494470decc6SDave Kleikamp 1495f7f4bccbSMingming Cao void __jbd2_journal_unfile_buffer(struct journal_head *jh) 1496470decc6SDave Kleikamp { 1497f7f4bccbSMingming Cao __jbd2_journal_temp_unlink_buffer(jh); 1498470decc6SDave Kleikamp jh->b_transaction = NULL; 1499470decc6SDave Kleikamp } 1500470decc6SDave Kleikamp 1501f7f4bccbSMingming Cao void jbd2_journal_unfile_buffer(journal_t *journal, struct journal_head *jh) 1502470decc6SDave Kleikamp { 1503470decc6SDave Kleikamp jbd_lock_bh_state(jh2bh(jh)); 1504470decc6SDave Kleikamp spin_lock(&journal->j_list_lock); 1505f7f4bccbSMingming Cao __jbd2_journal_unfile_buffer(jh); 1506470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 1507470decc6SDave Kleikamp jbd_unlock_bh_state(jh2bh(jh)); 1508470decc6SDave Kleikamp } 1509470decc6SDave Kleikamp 1510470decc6SDave Kleikamp /* 1511f7f4bccbSMingming Cao * Called from jbd2_journal_try_to_free_buffers(). 1512470decc6SDave Kleikamp * 1513470decc6SDave Kleikamp * Called under jbd_lock_bh_state(bh) 1514470decc6SDave Kleikamp */ 1515470decc6SDave Kleikamp static void 1516470decc6SDave Kleikamp __journal_try_to_free_buffer(journal_t *journal, struct buffer_head *bh) 1517470decc6SDave Kleikamp { 1518470decc6SDave Kleikamp struct journal_head *jh; 1519470decc6SDave Kleikamp 1520470decc6SDave Kleikamp jh = bh2jh(bh); 1521470decc6SDave Kleikamp 1522470decc6SDave Kleikamp if (buffer_locked(bh) || buffer_dirty(bh)) 1523470decc6SDave Kleikamp goto out; 1524470decc6SDave Kleikamp 15254019191bSMingming Cao if (jh->b_next_transaction != NULL) 1526470decc6SDave Kleikamp goto out; 1527470decc6SDave Kleikamp 1528470decc6SDave Kleikamp spin_lock(&journal->j_list_lock); 152987c89c23SJan Kara if (jh->b_cp_transaction != NULL && jh->b_transaction == NULL) { 1530470decc6SDave Kleikamp /* written-back checkpointed metadata buffer */ 1531470decc6SDave Kleikamp if (jh->b_jlist == BJ_None) { 1532470decc6SDave Kleikamp JBUFFER_TRACE(jh, "remove from checkpoint list"); 1533f7f4bccbSMingming Cao __jbd2_journal_remove_checkpoint(jh); 1534f7f4bccbSMingming Cao jbd2_journal_remove_journal_head(bh); 1535470decc6SDave Kleikamp __brelse(bh); 1536470decc6SDave Kleikamp } 1537470decc6SDave Kleikamp } 1538470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 1539470decc6SDave Kleikamp out: 1540470decc6SDave Kleikamp return; 1541470decc6SDave Kleikamp } 1542470decc6SDave Kleikamp 1543470decc6SDave Kleikamp /** 1544f7f4bccbSMingming Cao * int jbd2_journal_try_to_free_buffers() - try to free page buffers. 1545470decc6SDave Kleikamp * @journal: journal for operation 1546470decc6SDave Kleikamp * @page: to try and free 1547530576bbSMingming Cao * @gfp_mask: we use the mask to detect how hard should we try to release 1548530576bbSMingming Cao * buffers. If __GFP_WAIT and __GFP_FS is set, we wait for commit code to 1549530576bbSMingming Cao * release the buffers. 1550470decc6SDave Kleikamp * 1551470decc6SDave Kleikamp * 1552470decc6SDave Kleikamp * For all the buffers on this page, 1553470decc6SDave Kleikamp * if they are fully written out ordered data, move them onto BUF_CLEAN 1554470decc6SDave Kleikamp * so try_to_free_buffers() can reap them. 1555470decc6SDave Kleikamp * 1556470decc6SDave Kleikamp * This function returns non-zero if we wish try_to_free_buffers() 1557470decc6SDave Kleikamp * to be called. We do this if the page is releasable by try_to_free_buffers(). 1558470decc6SDave Kleikamp * We also do it if the page has locked or dirty buffers and the caller wants 1559470decc6SDave Kleikamp * us to perform sync or async writeout. 1560470decc6SDave Kleikamp * 1561470decc6SDave Kleikamp * This complicates JBD locking somewhat. We aren't protected by the 1562470decc6SDave Kleikamp * BKL here. We wish to remove the buffer from its committing or 1563f7f4bccbSMingming Cao * running transaction's ->t_datalist via __jbd2_journal_unfile_buffer. 1564470decc6SDave Kleikamp * 1565470decc6SDave Kleikamp * This may *change* the value of transaction_t->t_datalist, so anyone 1566470decc6SDave Kleikamp * who looks at t_datalist needs to lock against this function. 1567470decc6SDave Kleikamp * 1568f7f4bccbSMingming Cao * Even worse, someone may be doing a jbd2_journal_dirty_data on this 1569f7f4bccbSMingming Cao * buffer. So we need to lock against that. jbd2_journal_dirty_data() 1570470decc6SDave Kleikamp * will come out of the lock with the buffer dirty, which makes it 1571470decc6SDave Kleikamp * ineligible for release here. 1572470decc6SDave Kleikamp * 1573470decc6SDave Kleikamp * Who else is affected by this? hmm... Really the only contender 1574470decc6SDave Kleikamp * is do_get_write_access() - it could be looking at the buffer while 1575470decc6SDave Kleikamp * journal_try_to_free_buffer() is changing its state. But that 1576470decc6SDave Kleikamp * cannot happen because we never reallocate freed data as metadata 1577470decc6SDave Kleikamp * while the data is part of a transaction. Yes? 1578530576bbSMingming Cao * 1579530576bbSMingming Cao * Return 0 on failure, 1 on success 1580470decc6SDave Kleikamp */ 1581f7f4bccbSMingming Cao int jbd2_journal_try_to_free_buffers(journal_t *journal, 1582530576bbSMingming Cao struct page *page, gfp_t gfp_mask) 1583470decc6SDave Kleikamp { 1584470decc6SDave Kleikamp struct buffer_head *head; 1585470decc6SDave Kleikamp struct buffer_head *bh; 1586470decc6SDave Kleikamp int ret = 0; 1587470decc6SDave Kleikamp 1588470decc6SDave Kleikamp J_ASSERT(PageLocked(page)); 1589470decc6SDave Kleikamp 1590470decc6SDave Kleikamp head = page_buffers(page); 1591470decc6SDave Kleikamp bh = head; 1592470decc6SDave Kleikamp do { 1593470decc6SDave Kleikamp struct journal_head *jh; 1594470decc6SDave Kleikamp 1595470decc6SDave Kleikamp /* 1596470decc6SDave Kleikamp * We take our own ref against the journal_head here to avoid 1597470decc6SDave Kleikamp * having to add tons of locking around each instance of 1598530576bbSMingming Cao * jbd2_journal_remove_journal_head() and 1599530576bbSMingming Cao * jbd2_journal_put_journal_head(). 1600470decc6SDave Kleikamp */ 1601f7f4bccbSMingming Cao jh = jbd2_journal_grab_journal_head(bh); 1602470decc6SDave Kleikamp if (!jh) 1603470decc6SDave Kleikamp continue; 1604470decc6SDave Kleikamp 1605470decc6SDave Kleikamp jbd_lock_bh_state(bh); 1606470decc6SDave Kleikamp __journal_try_to_free_buffer(journal, bh); 1607f7f4bccbSMingming Cao jbd2_journal_put_journal_head(jh); 1608470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 1609470decc6SDave Kleikamp if (buffer_jbd(bh)) 1610470decc6SDave Kleikamp goto busy; 1611470decc6SDave Kleikamp } while ((bh = bh->b_this_page) != head); 1612530576bbSMingming Cao 1613470decc6SDave Kleikamp ret = try_to_free_buffers(page); 1614530576bbSMingming Cao 1615470decc6SDave Kleikamp busy: 1616470decc6SDave Kleikamp return ret; 1617470decc6SDave Kleikamp } 1618470decc6SDave Kleikamp 1619470decc6SDave Kleikamp /* 1620470decc6SDave Kleikamp * This buffer is no longer needed. If it is on an older transaction's 1621470decc6SDave Kleikamp * checkpoint list we need to record it on this transaction's forget list 1622470decc6SDave Kleikamp * to pin this buffer (and hence its checkpointing transaction) down until 1623470decc6SDave Kleikamp * this transaction commits. If the buffer isn't on a checkpoint list, we 1624470decc6SDave Kleikamp * release it. 1625470decc6SDave Kleikamp * Returns non-zero if JBD no longer has an interest in the buffer. 1626470decc6SDave Kleikamp * 1627470decc6SDave Kleikamp * Called under j_list_lock. 1628470decc6SDave Kleikamp * 1629470decc6SDave Kleikamp * Called under jbd_lock_bh_state(bh). 1630470decc6SDave Kleikamp */ 1631470decc6SDave Kleikamp static int __dispose_buffer(struct journal_head *jh, transaction_t *transaction) 1632470decc6SDave Kleikamp { 1633470decc6SDave Kleikamp int may_free = 1; 1634470decc6SDave Kleikamp struct buffer_head *bh = jh2bh(jh); 1635470decc6SDave Kleikamp 1636f7f4bccbSMingming Cao __jbd2_journal_unfile_buffer(jh); 1637470decc6SDave Kleikamp 1638470decc6SDave Kleikamp if (jh->b_cp_transaction) { 1639470decc6SDave Kleikamp JBUFFER_TRACE(jh, "on running+cp transaction"); 1640f91d1d04SJan Kara /* 1641f91d1d04SJan Kara * We don't want to write the buffer anymore, clear the 1642f91d1d04SJan Kara * bit so that we don't confuse checks in 1643f91d1d04SJan Kara * __journal_file_buffer 1644f91d1d04SJan Kara */ 1645f91d1d04SJan Kara clear_buffer_dirty(bh); 1646f7f4bccbSMingming Cao __jbd2_journal_file_buffer(jh, transaction, BJ_Forget); 1647470decc6SDave Kleikamp may_free = 0; 1648470decc6SDave Kleikamp } else { 1649470decc6SDave Kleikamp JBUFFER_TRACE(jh, "on running transaction"); 1650f7f4bccbSMingming Cao jbd2_journal_remove_journal_head(bh); 1651470decc6SDave Kleikamp __brelse(bh); 1652470decc6SDave Kleikamp } 1653470decc6SDave Kleikamp return may_free; 1654470decc6SDave Kleikamp } 1655470decc6SDave Kleikamp 1656470decc6SDave Kleikamp /* 1657f7f4bccbSMingming Cao * jbd2_journal_invalidatepage 1658470decc6SDave Kleikamp * 1659470decc6SDave Kleikamp * This code is tricky. It has a number of cases to deal with. 1660470decc6SDave Kleikamp * 1661470decc6SDave Kleikamp * There are two invariants which this code relies on: 1662470decc6SDave Kleikamp * 1663470decc6SDave Kleikamp * i_size must be updated on disk before we start calling invalidatepage on the 1664470decc6SDave Kleikamp * data. 1665470decc6SDave Kleikamp * 1666470decc6SDave Kleikamp * This is done in ext3 by defining an ext3_setattr method which 1667470decc6SDave Kleikamp * updates i_size before truncate gets going. By maintaining this 1668470decc6SDave Kleikamp * invariant, we can be sure that it is safe to throw away any buffers 1669470decc6SDave Kleikamp * attached to the current transaction: once the transaction commits, 1670470decc6SDave Kleikamp * we know that the data will not be needed. 1671470decc6SDave Kleikamp * 1672470decc6SDave Kleikamp * Note however that we can *not* throw away data belonging to the 1673470decc6SDave Kleikamp * previous, committing transaction! 1674470decc6SDave Kleikamp * 1675470decc6SDave Kleikamp * Any disk blocks which *are* part of the previous, committing 1676470decc6SDave Kleikamp * transaction (and which therefore cannot be discarded immediately) are 1677470decc6SDave Kleikamp * not going to be reused in the new running transaction 1678470decc6SDave Kleikamp * 1679470decc6SDave Kleikamp * The bitmap committed_data images guarantee this: any block which is 1680470decc6SDave Kleikamp * allocated in one transaction and removed in the next will be marked 1681470decc6SDave Kleikamp * as in-use in the committed_data bitmap, so cannot be reused until 1682470decc6SDave Kleikamp * the next transaction to delete the block commits. This means that 1683470decc6SDave Kleikamp * leaving committing buffers dirty is quite safe: the disk blocks 1684470decc6SDave Kleikamp * cannot be reallocated to a different file and so buffer aliasing is 1685470decc6SDave Kleikamp * not possible. 1686470decc6SDave Kleikamp * 1687470decc6SDave Kleikamp * 1688470decc6SDave Kleikamp * The above applies mainly to ordered data mode. In writeback mode we 1689470decc6SDave Kleikamp * don't make guarantees about the order in which data hits disk --- in 1690470decc6SDave Kleikamp * particular we don't guarantee that new dirty data is flushed before 1691470decc6SDave Kleikamp * transaction commit --- so it is always safe just to discard data 1692470decc6SDave Kleikamp * immediately in that mode. --sct 1693470decc6SDave Kleikamp */ 1694470decc6SDave Kleikamp 1695470decc6SDave Kleikamp /* 1696470decc6SDave Kleikamp * The journal_unmap_buffer helper function returns zero if the buffer 1697470decc6SDave Kleikamp * concerned remains pinned as an anonymous buffer belonging to an older 1698470decc6SDave Kleikamp * transaction. 1699470decc6SDave Kleikamp * 1700470decc6SDave Kleikamp * We're outside-transaction here. Either or both of j_running_transaction 1701470decc6SDave Kleikamp * and j_committing_transaction may be NULL. 1702470decc6SDave Kleikamp */ 1703470decc6SDave Kleikamp static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh) 1704470decc6SDave Kleikamp { 1705470decc6SDave Kleikamp transaction_t *transaction; 1706470decc6SDave Kleikamp struct journal_head *jh; 1707470decc6SDave Kleikamp int may_free = 1; 1708470decc6SDave Kleikamp int ret; 1709470decc6SDave Kleikamp 1710470decc6SDave Kleikamp BUFFER_TRACE(bh, "entry"); 1711470decc6SDave Kleikamp 1712470decc6SDave Kleikamp /* 1713470decc6SDave Kleikamp * It is safe to proceed here without the j_list_lock because the 1714470decc6SDave Kleikamp * buffers cannot be stolen by try_to_free_buffers as long as we are 1715470decc6SDave Kleikamp * holding the page lock. --sct 1716470decc6SDave Kleikamp */ 1717470decc6SDave Kleikamp 1718470decc6SDave Kleikamp if (!buffer_jbd(bh)) 1719470decc6SDave Kleikamp goto zap_buffer_unlocked; 1720470decc6SDave Kleikamp 172187c89c23SJan Kara /* OK, we have data buffer in journaled mode */ 1722470decc6SDave Kleikamp spin_lock(&journal->j_state_lock); 1723470decc6SDave Kleikamp jbd_lock_bh_state(bh); 1724470decc6SDave Kleikamp spin_lock(&journal->j_list_lock); 1725470decc6SDave Kleikamp 1726f7f4bccbSMingming Cao jh = jbd2_journal_grab_journal_head(bh); 1727470decc6SDave Kleikamp if (!jh) 1728470decc6SDave Kleikamp goto zap_buffer_no_jh; 1729470decc6SDave Kleikamp 1730ba869023Sdingdinghua /* 1731ba869023Sdingdinghua * We cannot remove the buffer from checkpoint lists until the 1732ba869023Sdingdinghua * transaction adding inode to orphan list (let's call it T) 1733ba869023Sdingdinghua * is committed. Otherwise if the transaction changing the 1734ba869023Sdingdinghua * buffer would be cleaned from the journal before T is 1735ba869023Sdingdinghua * committed, a crash will cause that the correct contents of 1736ba869023Sdingdinghua * the buffer will be lost. On the other hand we have to 1737ba869023Sdingdinghua * clear the buffer dirty bit at latest at the moment when the 1738ba869023Sdingdinghua * transaction marking the buffer as freed in the filesystem 1739ba869023Sdingdinghua * structures is committed because from that moment on the 1740ba869023Sdingdinghua * buffer can be reallocated and used by a different page. 1741ba869023Sdingdinghua * Since the block hasn't been freed yet but the inode has 1742ba869023Sdingdinghua * already been added to orphan list, it is safe for us to add 1743ba869023Sdingdinghua * the buffer to BJ_Forget list of the newest transaction. 1744ba869023Sdingdinghua */ 1745470decc6SDave Kleikamp transaction = jh->b_transaction; 1746470decc6SDave Kleikamp if (transaction == NULL) { 1747470decc6SDave Kleikamp /* First case: not on any transaction. If it 1748470decc6SDave Kleikamp * has no checkpoint link, then we can zap it: 1749470decc6SDave Kleikamp * it's a writeback-mode buffer so we don't care 1750470decc6SDave Kleikamp * if it hits disk safely. */ 1751470decc6SDave Kleikamp if (!jh->b_cp_transaction) { 1752470decc6SDave Kleikamp JBUFFER_TRACE(jh, "not on any transaction: zap"); 1753470decc6SDave Kleikamp goto zap_buffer; 1754470decc6SDave Kleikamp } 1755470decc6SDave Kleikamp 1756470decc6SDave Kleikamp if (!buffer_dirty(bh)) { 1757470decc6SDave Kleikamp /* bdflush has written it. We can drop it now */ 1758470decc6SDave Kleikamp goto zap_buffer; 1759470decc6SDave Kleikamp } 1760470decc6SDave Kleikamp 1761470decc6SDave Kleikamp /* OK, it must be in the journal but still not 1762470decc6SDave Kleikamp * written fully to disk: it's metadata or 1763470decc6SDave Kleikamp * journaled data... */ 1764470decc6SDave Kleikamp 1765470decc6SDave Kleikamp if (journal->j_running_transaction) { 1766470decc6SDave Kleikamp /* ... and once the current transaction has 1767470decc6SDave Kleikamp * committed, the buffer won't be needed any 1768470decc6SDave Kleikamp * longer. */ 1769470decc6SDave Kleikamp JBUFFER_TRACE(jh, "checkpointed: add to BJ_Forget"); 1770470decc6SDave Kleikamp ret = __dispose_buffer(jh, 1771470decc6SDave Kleikamp journal->j_running_transaction); 1772f7f4bccbSMingming Cao jbd2_journal_put_journal_head(jh); 1773470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 1774470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 1775470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 1776470decc6SDave Kleikamp return ret; 1777470decc6SDave Kleikamp } else { 1778470decc6SDave Kleikamp /* There is no currently-running transaction. So the 1779470decc6SDave Kleikamp * orphan record which we wrote for this file must have 1780470decc6SDave Kleikamp * passed into commit. We must attach this buffer to 1781470decc6SDave Kleikamp * the committing transaction, if it exists. */ 1782470decc6SDave Kleikamp if (journal->j_committing_transaction) { 1783470decc6SDave Kleikamp JBUFFER_TRACE(jh, "give to committing trans"); 1784470decc6SDave Kleikamp ret = __dispose_buffer(jh, 1785470decc6SDave Kleikamp journal->j_committing_transaction); 1786f7f4bccbSMingming Cao jbd2_journal_put_journal_head(jh); 1787470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 1788470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 1789470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 1790470decc6SDave Kleikamp return ret; 1791470decc6SDave Kleikamp } else { 1792470decc6SDave Kleikamp /* The orphan record's transaction has 1793470decc6SDave Kleikamp * committed. We can cleanse this buffer */ 1794470decc6SDave Kleikamp clear_buffer_jbddirty(bh); 1795470decc6SDave Kleikamp goto zap_buffer; 1796470decc6SDave Kleikamp } 1797470decc6SDave Kleikamp } 1798470decc6SDave Kleikamp } else if (transaction == journal->j_committing_transaction) { 17999b57988dSEric Sandeen JBUFFER_TRACE(jh, "on committing transaction"); 1800470decc6SDave Kleikamp /* 1801ba869023Sdingdinghua * The buffer is committing, we simply cannot touch 1802ba869023Sdingdinghua * it. So we just set j_next_transaction to the 1803ba869023Sdingdinghua * running transaction (if there is one) and mark 1804ba869023Sdingdinghua * buffer as freed so that commit code knows it should 1805ba869023Sdingdinghua * clear dirty bits when it is done with the buffer. 1806ba869023Sdingdinghua */ 1807470decc6SDave Kleikamp set_buffer_freed(bh); 1808ba869023Sdingdinghua if (journal->j_running_transaction && buffer_jbddirty(bh)) 1809ba869023Sdingdinghua jh->b_next_transaction = journal->j_running_transaction; 1810f7f4bccbSMingming Cao jbd2_journal_put_journal_head(jh); 1811470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 1812470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 1813470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 1814470decc6SDave Kleikamp return 0; 1815470decc6SDave Kleikamp } else { 1816470decc6SDave Kleikamp /* Good, the buffer belongs to the running transaction. 1817470decc6SDave Kleikamp * We are writing our own transaction's data, not any 1818470decc6SDave Kleikamp * previous one's, so it is safe to throw it away 1819470decc6SDave Kleikamp * (remember that we expect the filesystem to have set 1820470decc6SDave Kleikamp * i_size already for this truncate so recovery will not 1821470decc6SDave Kleikamp * expose the disk blocks we are discarding here.) */ 1822470decc6SDave Kleikamp J_ASSERT_JH(jh, transaction == journal->j_running_transaction); 18239b57988dSEric Sandeen JBUFFER_TRACE(jh, "on running transaction"); 1824470decc6SDave Kleikamp may_free = __dispose_buffer(jh, transaction); 1825470decc6SDave Kleikamp } 1826470decc6SDave Kleikamp 1827470decc6SDave Kleikamp zap_buffer: 1828f7f4bccbSMingming Cao jbd2_journal_put_journal_head(jh); 1829470decc6SDave Kleikamp zap_buffer_no_jh: 1830470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 1831470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 1832470decc6SDave Kleikamp spin_unlock(&journal->j_state_lock); 1833470decc6SDave Kleikamp zap_buffer_unlocked: 1834470decc6SDave Kleikamp clear_buffer_dirty(bh); 1835470decc6SDave Kleikamp J_ASSERT_BH(bh, !buffer_jbddirty(bh)); 1836470decc6SDave Kleikamp clear_buffer_mapped(bh); 1837470decc6SDave Kleikamp clear_buffer_req(bh); 1838470decc6SDave Kleikamp clear_buffer_new(bh); 1839470decc6SDave Kleikamp bh->b_bdev = NULL; 1840470decc6SDave Kleikamp return may_free; 1841470decc6SDave Kleikamp } 1842470decc6SDave Kleikamp 1843470decc6SDave Kleikamp /** 1844f7f4bccbSMingming Cao * void jbd2_journal_invalidatepage() 1845470decc6SDave Kleikamp * @journal: journal to use for flush... 1846470decc6SDave Kleikamp * @page: page to flush 1847470decc6SDave Kleikamp * @offset: length of page to invalidate. 1848470decc6SDave Kleikamp * 1849470decc6SDave Kleikamp * Reap page buffers containing data after offset in page. 1850470decc6SDave Kleikamp * 1851470decc6SDave Kleikamp */ 1852f7f4bccbSMingming Cao void jbd2_journal_invalidatepage(journal_t *journal, 1853470decc6SDave Kleikamp struct page *page, 1854470decc6SDave Kleikamp unsigned long offset) 1855470decc6SDave Kleikamp { 1856470decc6SDave Kleikamp struct buffer_head *head, *bh, *next; 1857470decc6SDave Kleikamp unsigned int curr_off = 0; 1858470decc6SDave Kleikamp int may_free = 1; 1859470decc6SDave Kleikamp 1860470decc6SDave Kleikamp if (!PageLocked(page)) 1861470decc6SDave Kleikamp BUG(); 1862470decc6SDave Kleikamp if (!page_has_buffers(page)) 1863470decc6SDave Kleikamp return; 1864470decc6SDave Kleikamp 1865470decc6SDave Kleikamp /* We will potentially be playing with lists other than just the 1866470decc6SDave Kleikamp * data lists (especially for journaled data mode), so be 1867470decc6SDave Kleikamp * cautious in our locking. */ 1868470decc6SDave Kleikamp 1869470decc6SDave Kleikamp head = bh = page_buffers(page); 1870470decc6SDave Kleikamp do { 1871470decc6SDave Kleikamp unsigned int next_off = curr_off + bh->b_size; 1872470decc6SDave Kleikamp next = bh->b_this_page; 1873470decc6SDave Kleikamp 1874470decc6SDave Kleikamp if (offset <= curr_off) { 1875470decc6SDave Kleikamp /* This block is wholly outside the truncation point */ 1876470decc6SDave Kleikamp lock_buffer(bh); 1877470decc6SDave Kleikamp may_free &= journal_unmap_buffer(journal, bh); 1878470decc6SDave Kleikamp unlock_buffer(bh); 1879470decc6SDave Kleikamp } 1880470decc6SDave Kleikamp curr_off = next_off; 1881470decc6SDave Kleikamp bh = next; 1882470decc6SDave Kleikamp 1883470decc6SDave Kleikamp } while (bh != head); 1884470decc6SDave Kleikamp 1885470decc6SDave Kleikamp if (!offset) { 1886470decc6SDave Kleikamp if (may_free && try_to_free_buffers(page)) 1887470decc6SDave Kleikamp J_ASSERT(!page_has_buffers(page)); 1888470decc6SDave Kleikamp } 1889470decc6SDave Kleikamp } 1890470decc6SDave Kleikamp 1891470decc6SDave Kleikamp /* 1892470decc6SDave Kleikamp * File a buffer on the given transaction list. 1893470decc6SDave Kleikamp */ 1894f7f4bccbSMingming Cao void __jbd2_journal_file_buffer(struct journal_head *jh, 1895470decc6SDave Kleikamp transaction_t *transaction, int jlist) 1896470decc6SDave Kleikamp { 1897470decc6SDave Kleikamp struct journal_head **list = NULL; 1898470decc6SDave Kleikamp int was_dirty = 0; 1899470decc6SDave Kleikamp struct buffer_head *bh = jh2bh(jh); 1900470decc6SDave Kleikamp 1901470decc6SDave Kleikamp J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh)); 1902470decc6SDave Kleikamp assert_spin_locked(&transaction->t_journal->j_list_lock); 1903470decc6SDave Kleikamp 1904470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_jlist < BJ_Types); 1905470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_transaction == transaction || 19064019191bSMingming Cao jh->b_transaction == NULL); 1907470decc6SDave Kleikamp 1908470decc6SDave Kleikamp if (jh->b_transaction && jh->b_jlist == jlist) 1909470decc6SDave Kleikamp return; 1910470decc6SDave Kleikamp 1911470decc6SDave Kleikamp if (jlist == BJ_Metadata || jlist == BJ_Reserved || 1912470decc6SDave Kleikamp jlist == BJ_Shadow || jlist == BJ_Forget) { 1913f91d1d04SJan Kara /* 1914f91d1d04SJan Kara * For metadata buffers, we track dirty bit in buffer_jbddirty 1915f91d1d04SJan Kara * instead of buffer_dirty. We should not see a dirty bit set 1916f91d1d04SJan Kara * here because we clear it in do_get_write_access but e.g. 1917f91d1d04SJan Kara * tune2fs can modify the sb and set the dirty bit at any time 1918f91d1d04SJan Kara * so we try to gracefully handle that. 1919f91d1d04SJan Kara */ 1920f91d1d04SJan Kara if (buffer_dirty(bh)) 1921f91d1d04SJan Kara warn_dirty_buffer(bh); 1922470decc6SDave Kleikamp if (test_clear_buffer_dirty(bh) || 1923470decc6SDave Kleikamp test_clear_buffer_jbddirty(bh)) 1924470decc6SDave Kleikamp was_dirty = 1; 1925470decc6SDave Kleikamp } 1926470decc6SDave Kleikamp 1927470decc6SDave Kleikamp if (jh->b_transaction) 1928f7f4bccbSMingming Cao __jbd2_journal_temp_unlink_buffer(jh); 1929470decc6SDave Kleikamp jh->b_transaction = transaction; 1930470decc6SDave Kleikamp 1931470decc6SDave Kleikamp switch (jlist) { 1932470decc6SDave Kleikamp case BJ_None: 1933470decc6SDave Kleikamp J_ASSERT_JH(jh, !jh->b_committed_data); 1934470decc6SDave Kleikamp J_ASSERT_JH(jh, !jh->b_frozen_data); 1935470decc6SDave Kleikamp return; 1936470decc6SDave Kleikamp case BJ_Metadata: 1937470decc6SDave Kleikamp transaction->t_nr_buffers++; 1938470decc6SDave Kleikamp list = &transaction->t_buffers; 1939470decc6SDave Kleikamp break; 1940470decc6SDave Kleikamp case BJ_Forget: 1941470decc6SDave Kleikamp list = &transaction->t_forget; 1942470decc6SDave Kleikamp break; 1943470decc6SDave Kleikamp case BJ_IO: 1944470decc6SDave Kleikamp list = &transaction->t_iobuf_list; 1945470decc6SDave Kleikamp break; 1946470decc6SDave Kleikamp case BJ_Shadow: 1947470decc6SDave Kleikamp list = &transaction->t_shadow_list; 1948470decc6SDave Kleikamp break; 1949470decc6SDave Kleikamp case BJ_LogCtl: 1950470decc6SDave Kleikamp list = &transaction->t_log_list; 1951470decc6SDave Kleikamp break; 1952470decc6SDave Kleikamp case BJ_Reserved: 1953470decc6SDave Kleikamp list = &transaction->t_reserved_list; 1954470decc6SDave Kleikamp break; 1955470decc6SDave Kleikamp } 1956470decc6SDave Kleikamp 1957470decc6SDave Kleikamp __blist_add_buffer(list, jh); 1958470decc6SDave Kleikamp jh->b_jlist = jlist; 1959470decc6SDave Kleikamp 1960470decc6SDave Kleikamp if (was_dirty) 1961470decc6SDave Kleikamp set_buffer_jbddirty(bh); 1962470decc6SDave Kleikamp } 1963470decc6SDave Kleikamp 1964f7f4bccbSMingming Cao void jbd2_journal_file_buffer(struct journal_head *jh, 1965470decc6SDave Kleikamp transaction_t *transaction, int jlist) 1966470decc6SDave Kleikamp { 1967470decc6SDave Kleikamp jbd_lock_bh_state(jh2bh(jh)); 1968470decc6SDave Kleikamp spin_lock(&transaction->t_journal->j_list_lock); 1969f7f4bccbSMingming Cao __jbd2_journal_file_buffer(jh, transaction, jlist); 1970470decc6SDave Kleikamp spin_unlock(&transaction->t_journal->j_list_lock); 1971470decc6SDave Kleikamp jbd_unlock_bh_state(jh2bh(jh)); 1972470decc6SDave Kleikamp } 1973470decc6SDave Kleikamp 1974470decc6SDave Kleikamp /* 1975470decc6SDave Kleikamp * Remove a buffer from its current buffer list in preparation for 1976470decc6SDave Kleikamp * dropping it from its current transaction entirely. If the buffer has 1977470decc6SDave Kleikamp * already started to be used by a subsequent transaction, refile the 1978470decc6SDave Kleikamp * buffer on that transaction's metadata list. 1979470decc6SDave Kleikamp * 1980470decc6SDave Kleikamp * Called under journal->j_list_lock 1981470decc6SDave Kleikamp * 1982470decc6SDave Kleikamp * Called under jbd_lock_bh_state(jh2bh(jh)) 1983470decc6SDave Kleikamp */ 1984f7f4bccbSMingming Cao void __jbd2_journal_refile_buffer(struct journal_head *jh) 1985470decc6SDave Kleikamp { 1986ba869023Sdingdinghua int was_dirty, jlist; 1987470decc6SDave Kleikamp struct buffer_head *bh = jh2bh(jh); 1988470decc6SDave Kleikamp 1989470decc6SDave Kleikamp J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh)); 1990470decc6SDave Kleikamp if (jh->b_transaction) 1991470decc6SDave Kleikamp assert_spin_locked(&jh->b_transaction->t_journal->j_list_lock); 1992470decc6SDave Kleikamp 1993470decc6SDave Kleikamp /* If the buffer is now unused, just drop it. */ 1994470decc6SDave Kleikamp if (jh->b_next_transaction == NULL) { 1995f7f4bccbSMingming Cao __jbd2_journal_unfile_buffer(jh); 1996470decc6SDave Kleikamp return; 1997470decc6SDave Kleikamp } 1998470decc6SDave Kleikamp 1999470decc6SDave Kleikamp /* 2000470decc6SDave Kleikamp * It has been modified by a later transaction: add it to the new 2001470decc6SDave Kleikamp * transaction's metadata list. 2002470decc6SDave Kleikamp */ 2003470decc6SDave Kleikamp 2004470decc6SDave Kleikamp was_dirty = test_clear_buffer_jbddirty(bh); 2005f7f4bccbSMingming Cao __jbd2_journal_temp_unlink_buffer(jh); 2006470decc6SDave Kleikamp jh->b_transaction = jh->b_next_transaction; 2007470decc6SDave Kleikamp jh->b_next_transaction = NULL; 2008ba869023Sdingdinghua if (buffer_freed(bh)) 2009ba869023Sdingdinghua jlist = BJ_Forget; 2010ba869023Sdingdinghua else if (jh->b_modified) 2011ba869023Sdingdinghua jlist = BJ_Metadata; 2012ba869023Sdingdinghua else 2013ba869023Sdingdinghua jlist = BJ_Reserved; 2014ba869023Sdingdinghua __jbd2_journal_file_buffer(jh, jh->b_transaction, jlist); 2015470decc6SDave Kleikamp J_ASSERT_JH(jh, jh->b_transaction->t_state == T_RUNNING); 2016470decc6SDave Kleikamp 2017470decc6SDave Kleikamp if (was_dirty) 2018470decc6SDave Kleikamp set_buffer_jbddirty(bh); 2019470decc6SDave Kleikamp } 2020470decc6SDave Kleikamp 2021470decc6SDave Kleikamp /* 2022470decc6SDave Kleikamp * For the unlocked version of this call, also make sure that any 2023470decc6SDave Kleikamp * hanging journal_head is cleaned up if necessary. 2024470decc6SDave Kleikamp * 2025f7f4bccbSMingming Cao * __jbd2_journal_refile_buffer is usually called as part of a single locked 2026470decc6SDave Kleikamp * operation on a buffer_head, in which the caller is probably going to 2027470decc6SDave Kleikamp * be hooking the journal_head onto other lists. In that case it is up 2028470decc6SDave Kleikamp * to the caller to remove the journal_head if necessary. For the 2029f7f4bccbSMingming Cao * unlocked jbd2_journal_refile_buffer call, the caller isn't going to be 2030470decc6SDave Kleikamp * doing anything else to the buffer so we need to do the cleanup 2031470decc6SDave Kleikamp * ourselves to avoid a jh leak. 2032470decc6SDave Kleikamp * 2033470decc6SDave Kleikamp * *** The journal_head may be freed by this call! *** 2034470decc6SDave Kleikamp */ 2035f7f4bccbSMingming Cao void jbd2_journal_refile_buffer(journal_t *journal, struct journal_head *jh) 2036470decc6SDave Kleikamp { 2037470decc6SDave Kleikamp struct buffer_head *bh = jh2bh(jh); 2038470decc6SDave Kleikamp 2039470decc6SDave Kleikamp jbd_lock_bh_state(bh); 2040470decc6SDave Kleikamp spin_lock(&journal->j_list_lock); 2041470decc6SDave Kleikamp 2042f7f4bccbSMingming Cao __jbd2_journal_refile_buffer(jh); 2043470decc6SDave Kleikamp jbd_unlock_bh_state(bh); 2044f7f4bccbSMingming Cao jbd2_journal_remove_journal_head(bh); 2045470decc6SDave Kleikamp 2046470decc6SDave Kleikamp spin_unlock(&journal->j_list_lock); 2047470decc6SDave Kleikamp __brelse(bh); 2048470decc6SDave Kleikamp } 2049c851ed54SJan Kara 2050c851ed54SJan Kara /* 2051c851ed54SJan Kara * File inode in the inode list of the handle's transaction 2052c851ed54SJan Kara */ 2053c851ed54SJan Kara int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *jinode) 2054c851ed54SJan Kara { 2055c851ed54SJan Kara transaction_t *transaction = handle->h_transaction; 2056c851ed54SJan Kara journal_t *journal = transaction->t_journal; 2057c851ed54SJan Kara 2058c851ed54SJan Kara if (is_handle_aborted(handle)) 2059c851ed54SJan Kara return -EIO; 2060c851ed54SJan Kara 2061c851ed54SJan Kara jbd_debug(4, "Adding inode %lu, tid:%d\n", jinode->i_vfs_inode->i_ino, 2062c851ed54SJan Kara transaction->t_tid); 2063c851ed54SJan Kara 2064c851ed54SJan Kara /* 2065c851ed54SJan Kara * First check whether inode isn't already on the transaction's 2066c851ed54SJan Kara * lists without taking the lock. Note that this check is safe 2067c851ed54SJan Kara * without the lock as we cannot race with somebody removing inode 2068c851ed54SJan Kara * from the transaction. The reason is that we remove inode from the 2069c851ed54SJan Kara * transaction only in journal_release_jbd_inode() and when we commit 2070c851ed54SJan Kara * the transaction. We are guarded from the first case by holding 2071c851ed54SJan Kara * a reference to the inode. We are safe against the second case 2072c851ed54SJan Kara * because if jinode->i_transaction == transaction, commit code 2073c851ed54SJan Kara * cannot touch the transaction because we hold reference to it, 2074c851ed54SJan Kara * and if jinode->i_next_transaction == transaction, commit code 2075c851ed54SJan Kara * will only file the inode where we want it. 2076c851ed54SJan Kara */ 2077c851ed54SJan Kara if (jinode->i_transaction == transaction || 2078c851ed54SJan Kara jinode->i_next_transaction == transaction) 2079c851ed54SJan Kara return 0; 2080c851ed54SJan Kara 2081c851ed54SJan Kara spin_lock(&journal->j_list_lock); 2082c851ed54SJan Kara 2083c851ed54SJan Kara if (jinode->i_transaction == transaction || 2084c851ed54SJan Kara jinode->i_next_transaction == transaction) 2085c851ed54SJan Kara goto done; 2086c851ed54SJan Kara 2087c851ed54SJan Kara /* On some different transaction's list - should be 2088c851ed54SJan Kara * the committing one */ 2089c851ed54SJan Kara if (jinode->i_transaction) { 2090c851ed54SJan Kara J_ASSERT(jinode->i_next_transaction == NULL); 2091c851ed54SJan Kara J_ASSERT(jinode->i_transaction == 2092c851ed54SJan Kara journal->j_committing_transaction); 2093c851ed54SJan Kara jinode->i_next_transaction = transaction; 2094c851ed54SJan Kara goto done; 2095c851ed54SJan Kara } 2096c851ed54SJan Kara /* Not on any transaction list... */ 2097c851ed54SJan Kara J_ASSERT(!jinode->i_next_transaction); 2098c851ed54SJan Kara jinode->i_transaction = transaction; 2099c851ed54SJan Kara list_add(&jinode->i_list, &transaction->t_inode_list); 2100c851ed54SJan Kara done: 2101c851ed54SJan Kara spin_unlock(&journal->j_list_lock); 2102c851ed54SJan Kara 2103c851ed54SJan Kara return 0; 2104c851ed54SJan Kara } 2105c851ed54SJan Kara 2106c851ed54SJan Kara /* 21077f5aa215SJan Kara * File truncate and transaction commit interact with each other in a 21087f5aa215SJan Kara * non-trivial way. If a transaction writing data block A is 21097f5aa215SJan Kara * committing, we cannot discard the data by truncate until we have 21107f5aa215SJan Kara * written them. Otherwise if we crashed after the transaction with 21117f5aa215SJan Kara * write has committed but before the transaction with truncate has 21127f5aa215SJan Kara * committed, we could see stale data in block A. This function is a 21137f5aa215SJan Kara * helper to solve this problem. It starts writeout of the truncated 21147f5aa215SJan Kara * part in case it is in the committing transaction. 21157f5aa215SJan Kara * 21167f5aa215SJan Kara * Filesystem code must call this function when inode is journaled in 21177f5aa215SJan Kara * ordered mode before truncation happens and after the inode has been 21187f5aa215SJan Kara * placed on orphan list with the new inode size. The second condition 21197f5aa215SJan Kara * avoids the race that someone writes new data and we start 21207f5aa215SJan Kara * committing the transaction after this function has been called but 21217f5aa215SJan Kara * before a transaction for truncate is started (and furthermore it 21227f5aa215SJan Kara * allows us to optimize the case where the addition to orphan list 21237f5aa215SJan Kara * happens in the same transaction as write --- we don't have to write 21247f5aa215SJan Kara * any data in such case). 2125c851ed54SJan Kara */ 21267f5aa215SJan Kara int jbd2_journal_begin_ordered_truncate(journal_t *journal, 21277f5aa215SJan Kara struct jbd2_inode *jinode, 2128c851ed54SJan Kara loff_t new_size) 2129c851ed54SJan Kara { 21307f5aa215SJan Kara transaction_t *inode_trans, *commit_trans; 2131c851ed54SJan Kara int ret = 0; 2132c851ed54SJan Kara 21337f5aa215SJan Kara /* This is a quick check to avoid locking if not necessary */ 21347f5aa215SJan Kara if (!jinode->i_transaction) 2135c851ed54SJan Kara goto out; 21367f5aa215SJan Kara /* Locks are here just to force reading of recent values, it is 21377f5aa215SJan Kara * enough that the transaction was not committing before we started 21387f5aa215SJan Kara * a transaction adding the inode to orphan list */ 2139c851ed54SJan Kara spin_lock(&journal->j_state_lock); 2140c851ed54SJan Kara commit_trans = journal->j_committing_transaction; 2141c851ed54SJan Kara spin_unlock(&journal->j_state_lock); 21427f5aa215SJan Kara spin_lock(&journal->j_list_lock); 21437f5aa215SJan Kara inode_trans = jinode->i_transaction; 21447f5aa215SJan Kara spin_unlock(&journal->j_list_lock); 21457f5aa215SJan Kara if (inode_trans == commit_trans) { 21467f5aa215SJan Kara ret = filemap_fdatawrite_range(jinode->i_vfs_inode->i_mapping, 2147c851ed54SJan Kara new_size, LLONG_MAX); 2148c851ed54SJan Kara if (ret) 2149c851ed54SJan Kara jbd2_journal_abort(journal, ret); 2150c851ed54SJan Kara } 2151c851ed54SJan Kara out: 2152c851ed54SJan Kara return ret; 2153c851ed54SJan Kara } 2154