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authorJosé Pekkarinen <jose.pekkarinen@nokia.com>2016-04-11 10:41:07 +0300
committerJosé Pekkarinen <jose.pekkarinen@nokia.com>2016-04-13 08:17:18 +0300
commite09b41010ba33a20a87472ee821fa407a5b8da36 (patch)
treed10dc367189862e7ca5c592f033dc3726e1df4e3 /kernel/fs/jbd
parentf93b97fd65072de626c074dbe099a1fff05ce060 (diff)
These changes are the raw update to linux-4.4.6-rt14. Kernel sources
are taken from kernel.org, and rt patch from the rt wiki download page. During the rebasing, the following patch collided: Force tick interrupt and get rid of softirq magic(I70131fb85). Collisions have been removed because its logic was found on the source already. Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769 Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>
Diffstat (limited to 'kernel/fs/jbd')
-rw-r--r--kernel/fs/jbd/Kconfig30
-rw-r--r--kernel/fs/jbd/Makefile7
-rw-r--r--kernel/fs/jbd/checkpoint.c784
-rw-r--r--kernel/fs/jbd/commit.c1021
-rw-r--r--kernel/fs/jbd/journal.c2145
-rw-r--r--kernel/fs/jbd/recovery.c594
-rw-r--r--kernel/fs/jbd/revoke.c733
-rw-r--r--kernel/fs/jbd/transaction.c2237
8 files changed, 0 insertions, 7551 deletions
diff --git a/kernel/fs/jbd/Kconfig b/kernel/fs/jbd/Kconfig
deleted file mode 100644
index 4e28beeed..000000000
--- a/kernel/fs/jbd/Kconfig
+++ /dev/null
@@ -1,30 +0,0 @@
-config JBD
- tristate
- help
- This is a generic journalling layer for block devices. It is
- currently used by the ext3 file system, but it could also be
- used to add journal support to other file systems or block
- devices such as RAID or LVM.
-
- If you are using the ext3 file system, you need to say Y here.
- If you are not using ext3 then you will probably want to say N.
-
- To compile this device as a module, choose M here: the module will be
- called jbd. If you are compiling ext3 into the kernel, you
- cannot compile this code as a module.
-
-config JBD_DEBUG
- bool "JBD (ext3) debugging support"
- depends on JBD && DEBUG_FS
- help
- If you are using the ext3 journaled file system (or potentially any
- other file system/device using JBD), this option allows you to
- enable debugging output while the system is running, in order to
- help track down any problems you are having. By default the
- debugging output will be turned off.
-
- If you select Y here, then you will be able to turn on debugging
- with "echo N > /sys/kernel/debug/jbd/jbd-debug", where N is a
- number between 1 and 5, the higher the number, the more debugging
- output is generated. To turn debugging off again, do
- "echo 0 > /sys/kernel/debug/jbd/jbd-debug".
diff --git a/kernel/fs/jbd/Makefile b/kernel/fs/jbd/Makefile
deleted file mode 100644
index 54aca4868..000000000
--- a/kernel/fs/jbd/Makefile
+++ /dev/null
@@ -1,7 +0,0 @@
-#
-# Makefile for the linux journaling routines.
-#
-
-obj-$(CONFIG_JBD) += jbd.o
-
-jbd-objs := transaction.o commit.o recovery.o checkpoint.o revoke.o journal.o
diff --git a/kernel/fs/jbd/checkpoint.c b/kernel/fs/jbd/checkpoint.c
deleted file mode 100644
index 95debd71e..000000000
--- a/kernel/fs/jbd/checkpoint.c
+++ /dev/null
@@ -1,784 +0,0 @@
-/*
- * linux/fs/jbd/checkpoint.c
- *
- * Written by Stephen C. Tweedie <sct@redhat.com>, 1999
- *
- * Copyright 1999 Red Hat Software --- All Rights Reserved
- *
- * This file is part of the Linux kernel and is made available under
- * the terms of the GNU General Public License, version 2, or at your
- * option, any later version, incorporated herein by reference.
- *
- * Checkpoint routines for the generic filesystem journaling code.
- * Part of the ext2fs journaling system.
- *
- * Checkpointing is the process of ensuring that a section of the log is
- * committed fully to disk, so that that portion of the log can be
- * reused.
- */
-
-#include <linux/time.h>
-#include <linux/fs.h>
-#include <linux/jbd.h>
-#include <linux/errno.h>
-#include <linux/slab.h>
-#include <linux/blkdev.h>
-#include <trace/events/jbd.h>
-
-/*
- * Unlink a buffer from a transaction checkpoint list.
- *
- * Called with j_list_lock held.
- */
-static inline void __buffer_unlink_first(struct journal_head *jh)
-{
- transaction_t *transaction = jh->b_cp_transaction;
-
- jh->b_cpnext->b_cpprev = jh->b_cpprev;
- jh->b_cpprev->b_cpnext = jh->b_cpnext;
- if (transaction->t_checkpoint_list == jh) {
- transaction->t_checkpoint_list = jh->b_cpnext;
- if (transaction->t_checkpoint_list == jh)
- transaction->t_checkpoint_list = NULL;
- }
-}
-
-/*
- * Unlink a buffer from a transaction checkpoint(io) list.
- *
- * Called with j_list_lock held.
- */
-static inline void __buffer_unlink(struct journal_head *jh)
-{
- transaction_t *transaction = jh->b_cp_transaction;
-
- __buffer_unlink_first(jh);
- if (transaction->t_checkpoint_io_list == jh) {
- transaction->t_checkpoint_io_list = jh->b_cpnext;
- if (transaction->t_checkpoint_io_list == jh)
- transaction->t_checkpoint_io_list = NULL;
- }
-}
-
-/*
- * Move a buffer from the checkpoint list to the checkpoint io list
- *
- * Called with j_list_lock held
- */
-static inline void __buffer_relink_io(struct journal_head *jh)
-{
- transaction_t *transaction = jh->b_cp_transaction;
-
- __buffer_unlink_first(jh);
-
- if (!transaction->t_checkpoint_io_list) {
- jh->b_cpnext = jh->b_cpprev = jh;
- } else {
- jh->b_cpnext = transaction->t_checkpoint_io_list;
- jh->b_cpprev = transaction->t_checkpoint_io_list->b_cpprev;
- jh->b_cpprev->b_cpnext = jh;
- jh->b_cpnext->b_cpprev = jh;
- }
- transaction->t_checkpoint_io_list = jh;
-}
-
-/*
- * Try to release a checkpointed buffer from its transaction.
- * Returns 1 if we released it and 2 if we also released the
- * whole transaction.
- *
- * Requires j_list_lock
- * Called under jbd_lock_bh_state(jh2bh(jh)), and drops it
- */
-static int __try_to_free_cp_buf(struct journal_head *jh)
-{
- int ret = 0;
- struct buffer_head *bh = jh2bh(jh);
-
- if (jh->b_jlist == BJ_None && !buffer_locked(bh) &&
- !buffer_dirty(bh) && !buffer_write_io_error(bh)) {
- /*
- * Get our reference so that bh cannot be freed before
- * we unlock it
- */
- get_bh(bh);
- JBUFFER_TRACE(jh, "remove from checkpoint list");
- ret = __journal_remove_checkpoint(jh) + 1;
- jbd_unlock_bh_state(bh);
- BUFFER_TRACE(bh, "release");
- __brelse(bh);
- } else {
- jbd_unlock_bh_state(bh);
- }
- return ret;
-}
-
-/*
- * __log_wait_for_space: wait until there is space in the journal.
- *
- * Called under j-state_lock *only*. It will be unlocked if we have to wait
- * for a checkpoint to free up some space in the log.
- */
-void __log_wait_for_space(journal_t *journal)
-{
- int nblocks, space_left;
- assert_spin_locked(&journal->j_state_lock);
-
- nblocks = jbd_space_needed(journal);
- while (__log_space_left(journal) < nblocks) {
- if (journal->j_flags & JFS_ABORT)
- return;
- spin_unlock(&journal->j_state_lock);
- if (current->plug)
- io_schedule();
- mutex_lock(&journal->j_checkpoint_mutex);
-
- /*
- * Test again, another process may have checkpointed while we
- * were waiting for the checkpoint lock. If there are no
- * transactions ready to be checkpointed, try to recover
- * journal space by calling cleanup_journal_tail(), and if
- * that doesn't work, by waiting for the currently committing
- * transaction to complete. If there is absolutely no way
- * to make progress, this is either a BUG or corrupted
- * filesystem, so abort the journal and leave a stack
- * trace for forensic evidence.
- */
- spin_lock(&journal->j_state_lock);
- spin_lock(&journal->j_list_lock);
- nblocks = jbd_space_needed(journal);
- space_left = __log_space_left(journal);
- if (space_left < nblocks) {
- int chkpt = journal->j_checkpoint_transactions != NULL;
- tid_t tid = 0;
-
- if (journal->j_committing_transaction)
- tid = journal->j_committing_transaction->t_tid;
- spin_unlock(&journal->j_list_lock);
- spin_unlock(&journal->j_state_lock);
- if (chkpt) {
- log_do_checkpoint(journal);
- } else if (cleanup_journal_tail(journal) == 0) {
- /* We were able to recover space; yay! */
- ;
- } else if (tid) {
- log_wait_commit(journal, tid);
- } else {
- printk(KERN_ERR "%s: needed %d blocks and "
- "only had %d space available\n",
- __func__, nblocks, space_left);
- printk(KERN_ERR "%s: no way to get more "
- "journal space\n", __func__);
- WARN_ON(1);
- journal_abort(journal, 0);
- }
- spin_lock(&journal->j_state_lock);
- } else {
- spin_unlock(&journal->j_list_lock);
- }
- mutex_unlock(&journal->j_checkpoint_mutex);
- }
-}
-
-/*
- * We were unable to perform jbd_trylock_bh_state() inside j_list_lock.
- * The caller must restart a list walk. Wait for someone else to run
- * jbd_unlock_bh_state().
- */
-static void jbd_sync_bh(journal_t *journal, struct buffer_head *bh)
- __releases(journal->j_list_lock)
-{
- get_bh(bh);
- spin_unlock(&journal->j_list_lock);
- jbd_lock_bh_state(bh);
- jbd_unlock_bh_state(bh);
- put_bh(bh);
-}
-
-/*
- * Clean up transaction's list of buffers submitted for io.
- * We wait for any pending IO to complete and remove any clean
- * buffers. Note that we take the buffers in the opposite ordering
- * from the one in which they were submitted for IO.
- *
- * Return 0 on success, and return <0 if some buffers have failed
- * to be written out.
- *
- * Called with j_list_lock held.
- */
-static int __wait_cp_io(journal_t *journal, transaction_t *transaction)
-{
- struct journal_head *jh;
- struct buffer_head *bh;
- tid_t this_tid;
- int released = 0;
- int ret = 0;
-
- this_tid = transaction->t_tid;
-restart:
- /* Did somebody clean up the transaction in the meanwhile? */
- if (journal->j_checkpoint_transactions != transaction ||
- transaction->t_tid != this_tid)
- return ret;
- while (!released && transaction->t_checkpoint_io_list) {
- jh = transaction->t_checkpoint_io_list;
- bh = jh2bh(jh);
- if (!jbd_trylock_bh_state(bh)) {
- jbd_sync_bh(journal, bh);
- spin_lock(&journal->j_list_lock);
- goto restart;
- }
- get_bh(bh);
- if (buffer_locked(bh)) {
- spin_unlock(&journal->j_list_lock);
- jbd_unlock_bh_state(bh);
- wait_on_buffer(bh);
- /* the journal_head may have gone by now */
- BUFFER_TRACE(bh, "brelse");
- __brelse(bh);
- spin_lock(&journal->j_list_lock);
- goto restart;
- }
- if (unlikely(buffer_write_io_error(bh)))
- ret = -EIO;
-
- /*
- * Now in whatever state the buffer currently is, we know that
- * it has been written out and so we can drop it from the list
- */
- released = __journal_remove_checkpoint(jh);
- jbd_unlock_bh_state(bh);
- __brelse(bh);
- }
-
- return ret;
-}
-
-#define NR_BATCH 64
-
-static void
-__flush_batch(journal_t *journal, struct buffer_head **bhs, int *batch_count)
-{
- int i;
- struct blk_plug plug;
-
- blk_start_plug(&plug);
- for (i = 0; i < *batch_count; i++)
- write_dirty_buffer(bhs[i], WRITE_SYNC);
- blk_finish_plug(&plug);
-
- for (i = 0; i < *batch_count; i++) {
- struct buffer_head *bh = bhs[i];
- clear_buffer_jwrite(bh);
- BUFFER_TRACE(bh, "brelse");
- __brelse(bh);
- }
- *batch_count = 0;
-}
-
-/*
- * Try to flush one buffer from the checkpoint list to disk.
- *
- * Return 1 if something happened which requires us to abort the current
- * scan of the checkpoint list. Return <0 if the buffer has failed to
- * be written out.
- *
- * Called with j_list_lock held and drops it if 1 is returned
- * Called under jbd_lock_bh_state(jh2bh(jh)), and drops it
- */
-static int __process_buffer(journal_t *journal, struct journal_head *jh,
- struct buffer_head **bhs, int *batch_count)
-{
- struct buffer_head *bh = jh2bh(jh);
- int ret = 0;
-
- if (buffer_locked(bh)) {
- get_bh(bh);
- spin_unlock(&journal->j_list_lock);
- jbd_unlock_bh_state(bh);
- wait_on_buffer(bh);
- /* the journal_head may have gone by now */
- BUFFER_TRACE(bh, "brelse");
- __brelse(bh);
- ret = 1;
- } else if (jh->b_transaction != NULL) {
- transaction_t *t = jh->b_transaction;
- tid_t tid = t->t_tid;
-
- spin_unlock(&journal->j_list_lock);
- jbd_unlock_bh_state(bh);
- log_start_commit(journal, tid);
- log_wait_commit(journal, tid);
- ret = 1;
- } else if (!buffer_dirty(bh)) {
- ret = 1;
- if (unlikely(buffer_write_io_error(bh)))
- ret = -EIO;
- get_bh(bh);
- J_ASSERT_JH(jh, !buffer_jbddirty(bh));
- BUFFER_TRACE(bh, "remove from checkpoint");
- __journal_remove_checkpoint(jh);
- spin_unlock(&journal->j_list_lock);
- jbd_unlock_bh_state(bh);
- __brelse(bh);
- } else {
- /*
- * Important: we are about to write the buffer, and
- * possibly block, while still holding the journal lock.
- * We cannot afford to let the transaction logic start
- * messing around with this buffer before we write it to
- * disk, as that would break recoverability.
- */
- BUFFER_TRACE(bh, "queue");
- get_bh(bh);
- J_ASSERT_BH(bh, !buffer_jwrite(bh));
- set_buffer_jwrite(bh);
- bhs[*batch_count] = bh;
- __buffer_relink_io(jh);
- jbd_unlock_bh_state(bh);
- (*batch_count)++;
- if (*batch_count == NR_BATCH) {
- spin_unlock(&journal->j_list_lock);
- __flush_batch(journal, bhs, batch_count);
- ret = 1;
- }
- }
- return ret;
-}
-
-/*
- * Perform an actual checkpoint. We take the first transaction on the
- * list of transactions to be checkpointed and send all its buffers
- * to disk. We submit larger chunks of data at once.
- *
- * The journal should be locked before calling this function.
- * Called with j_checkpoint_mutex held.
- */
-int log_do_checkpoint(journal_t *journal)
-{
- transaction_t *transaction;
- tid_t this_tid;
- int result;
-
- jbd_debug(1, "Start checkpoint\n");
-
- /*
- * First thing: if there are any transactions in the log which
- * don't need checkpointing, just eliminate them from the
- * journal straight away.
- */
- result = cleanup_journal_tail(journal);
- trace_jbd_checkpoint(journal, result);
- jbd_debug(1, "cleanup_journal_tail returned %d\n", result);
- if (result <= 0)
- return result;
-
- /*
- * OK, we need to start writing disk blocks. Take one transaction
- * and write it.
- */
- result = 0;
- spin_lock(&journal->j_list_lock);
- if (!journal->j_checkpoint_transactions)
- goto out;
- transaction = journal->j_checkpoint_transactions;
- this_tid = transaction->t_tid;
-restart:
- /*
- * If someone cleaned up this transaction while we slept, we're
- * done (maybe it's a new transaction, but it fell at the same
- * address).
- */
- if (journal->j_checkpoint_transactions == transaction &&
- transaction->t_tid == this_tid) {
- int batch_count = 0;
- struct buffer_head *bhs[NR_BATCH];
- struct journal_head *jh;
- int retry = 0, err;
-
- while (!retry && transaction->t_checkpoint_list) {
- struct buffer_head *bh;
-
- jh = transaction->t_checkpoint_list;
- bh = jh2bh(jh);
- if (!jbd_trylock_bh_state(bh)) {
- jbd_sync_bh(journal, bh);
- retry = 1;
- break;
- }
- retry = __process_buffer(journal, jh, bhs,&batch_count);
- if (retry < 0 && !result)
- result = retry;
- if (!retry && (need_resched() ||
- spin_needbreak(&journal->j_list_lock))) {
- spin_unlock(&journal->j_list_lock);
- retry = 1;
- break;
- }
- }
-
- if (batch_count) {
- if (!retry) {
- spin_unlock(&journal->j_list_lock);
- retry = 1;
- }
- __flush_batch(journal, bhs, &batch_count);
- }
-
- if (retry) {
- spin_lock(&journal->j_list_lock);
- goto restart;
- }
- /*
- * Now we have cleaned up the first transaction's checkpoint
- * list. Let's clean up the second one
- */
- err = __wait_cp_io(journal, transaction);
- if (!result)
- result = err;
- }
-out:
- spin_unlock(&journal->j_list_lock);
- if (result < 0)
- journal_abort(journal, result);
- else
- result = cleanup_journal_tail(journal);
-
- return (result < 0) ? result : 0;
-}
-
-/*
- * Check the list of checkpoint transactions for the journal to see if
- * we have already got rid of any since the last update of the log tail
- * in the journal superblock. If so, we can instantly roll the
- * superblock forward to remove those transactions from the log.
- *
- * Return <0 on error, 0 on success, 1 if there was nothing to clean up.
- *
- * This is the only part of the journaling code which really needs to be
- * aware of transaction aborts. Checkpointing involves writing to the
- * main filesystem area rather than to the journal, so it can proceed
- * even in abort state, but we must not update the super block if
- * checkpointing may have failed. Otherwise, we would lose some metadata
- * buffers which should be written-back to the filesystem.
- */
-
-int cleanup_journal_tail(journal_t *journal)
-{
- transaction_t * transaction;
- tid_t first_tid;
- unsigned int blocknr, freed;
-
- if (is_journal_aborted(journal))
- return 1;
-
- /*
- * OK, work out the oldest transaction remaining in the log, and
- * the log block it starts at.
- *
- * If the log is now empty, we need to work out which is the
- * next transaction ID we will write, and where it will
- * start.
- */
- spin_lock(&journal->j_state_lock);
- spin_lock(&journal->j_list_lock);
- transaction = journal->j_checkpoint_transactions;
- if (transaction) {
- first_tid = transaction->t_tid;
- blocknr = transaction->t_log_start;
- } else if ((transaction = journal->j_committing_transaction) != NULL) {
- first_tid = transaction->t_tid;
- blocknr = transaction->t_log_start;
- } else if ((transaction = journal->j_running_transaction) != NULL) {
- first_tid = transaction->t_tid;
- blocknr = journal->j_head;
- } else {
- first_tid = journal->j_transaction_sequence;
- blocknr = journal->j_head;
- }
- spin_unlock(&journal->j_list_lock);
- J_ASSERT(blocknr != 0);
-
- /* If the oldest pinned transaction is at the tail of the log
- already then there's not much we can do right now. */
- if (journal->j_tail_sequence == first_tid) {
- spin_unlock(&journal->j_state_lock);
- return 1;
- }
- spin_unlock(&journal->j_state_lock);
-
- /*
- * We need to make sure that any blocks that were recently written out
- * --- perhaps by log_do_checkpoint() --- are flushed out before we
- * drop the transactions from the journal. Similarly we need to be sure
- * superblock makes it to disk before next transaction starts reusing
- * freed space (otherwise we could replay some blocks of the new
- * transaction thinking they belong to the old one). So we use
- * WRITE_FLUSH_FUA. It's unlikely this will be necessary, especially
- * with an appropriately sized journal, but we need this to guarantee
- * correctness. Fortunately cleanup_journal_tail() doesn't get called
- * all that often.
- */
- journal_update_sb_log_tail(journal, first_tid, blocknr,
- WRITE_FLUSH_FUA);
-
- spin_lock(&journal->j_state_lock);
- /* OK, update the superblock to recover the freed space.
- * Physical blocks come first: have we wrapped beyond the end of
- * the log? */
- freed = blocknr - journal->j_tail;
- if (blocknr < journal->j_tail)
- freed = freed + journal->j_last - journal->j_first;
-
- trace_jbd_cleanup_journal_tail(journal, first_tid, blocknr, freed);
- jbd_debug(1,
- "Cleaning journal tail from %d to %d (offset %u), "
- "freeing %u\n",
- journal->j_tail_sequence, first_tid, blocknr, freed);
-
- journal->j_free += freed;
- journal->j_tail_sequence = first_tid;
- journal->j_tail = blocknr;
- spin_unlock(&journal->j_state_lock);
- return 0;
-}
-
-
-/* Checkpoint list management */
-
-/*
- * journal_clean_one_cp_list
- *
- * Find all the written-back checkpoint buffers in the given list and release
- * them.
- *
- * Called with j_list_lock held.
- * Returns number of buffers reaped (for debug)
- */
-
-static int journal_clean_one_cp_list(struct journal_head *jh, int *released)
-{
- struct journal_head *last_jh;
- struct journal_head *next_jh = jh;
- int ret, freed = 0;
-
- *released = 0;
- if (!jh)
- return 0;
-
- last_jh = jh->b_cpprev;
- do {
- jh = next_jh;
- next_jh = jh->b_cpnext;
- /* Use trylock because of the ranking */
- if (jbd_trylock_bh_state(jh2bh(jh))) {
- ret = __try_to_free_cp_buf(jh);
- if (ret) {
- freed++;
- if (ret == 2) {
- *released = 1;
- return freed;
- }
- }
- }
- /*
- * This function only frees up some memory
- * if possible so we dont have an obligation
- * to finish processing. Bail out if preemption
- * requested:
- */
- if (need_resched())
- return freed;
- } while (jh != last_jh);
-
- return freed;
-}
-
-/*
- * journal_clean_checkpoint_list
- *
- * Find all the written-back checkpoint buffers in the journal and release them.
- *
- * Called with the journal locked.
- * Called with j_list_lock held.
- * Returns number of buffers reaped (for debug)
- */
-
-int __journal_clean_checkpoint_list(journal_t *journal)
-{
- transaction_t *transaction, *last_transaction, *next_transaction;
- int ret = 0;
- int released;
-
- transaction = journal->j_checkpoint_transactions;
- if (!transaction)
- goto out;
-
- last_transaction = transaction->t_cpprev;
- next_transaction = transaction;
- do {
- transaction = next_transaction;
- next_transaction = transaction->t_cpnext;
- ret += journal_clean_one_cp_list(transaction->
- t_checkpoint_list, &released);
- /*
- * This function only frees up some memory if possible so we
- * dont have an obligation to finish processing. Bail out if
- * preemption requested:
- */
- if (need_resched())
- goto out;
- if (released)
- continue;
- /*
- * It is essential that we are as careful as in the case of
- * t_checkpoint_list with removing the buffer from the list as
- * we can possibly see not yet submitted buffers on io_list
- */
- ret += journal_clean_one_cp_list(transaction->
- t_checkpoint_io_list, &released);
- if (need_resched())
- goto out;
- } while (transaction != last_transaction);
-out:
- return ret;
-}
-
-/*
- * journal_remove_checkpoint: called after a buffer has been committed
- * to disk (either by being write-back flushed to disk, or being
- * committed to the log).
- *
- * We cannot safely clean a transaction out of the log until all of the
- * buffer updates committed in that transaction have safely been stored
- * elsewhere on disk. To achieve this, all of the buffers in a
- * transaction need to be maintained on the transaction's checkpoint
- * lists until they have been rewritten, at which point this function is
- * called to remove the buffer from the existing transaction's
- * checkpoint lists.
- *
- * The function returns 1 if it frees the transaction, 0 otherwise.
- * The function can free jh and bh.
- *
- * This function is called with j_list_lock held.
- * This function is called with jbd_lock_bh_state(jh2bh(jh))
- */
-
-int __journal_remove_checkpoint(struct journal_head *jh)
-{
- transaction_t *transaction;
- journal_t *journal;
- int ret = 0;
-
- JBUFFER_TRACE(jh, "entry");
-
- if ((transaction = jh->b_cp_transaction) == NULL) {
- JBUFFER_TRACE(jh, "not on transaction");
- goto out;
- }
- journal = transaction->t_journal;
-
- JBUFFER_TRACE(jh, "removing from transaction");
- __buffer_unlink(jh);
- jh->b_cp_transaction = NULL;
- journal_put_journal_head(jh);
-
- if (transaction->t_checkpoint_list != NULL ||
- transaction->t_checkpoint_io_list != NULL)
- goto out;
-
- /*
- * There is one special case to worry about: if we have just pulled the
- * buffer off a running or committing transaction's checkpoing list,
- * then even if the checkpoint list is empty, the transaction obviously
- * cannot be dropped!
- *
- * The locking here around t_state is a bit sleazy.
- * See the comment at the end of journal_commit_transaction().
- */
- if (transaction->t_state != T_FINISHED)
- goto out;
-
- /* OK, that was the last buffer for the transaction: we can now
- safely remove this transaction from the log */
-
- __journal_drop_transaction(journal, transaction);
-
- /* Just in case anybody was waiting for more transactions to be
- checkpointed... */
- wake_up(&journal->j_wait_logspace);
- ret = 1;
-out:
- return ret;
-}
-
-/*
- * journal_insert_checkpoint: put a committed buffer onto a checkpoint
- * list so that we know when it is safe to clean the transaction out of
- * the log.
- *
- * Called with the journal locked.
- * Called with j_list_lock held.
- */
-void __journal_insert_checkpoint(struct journal_head *jh,
- transaction_t *transaction)
-{
- JBUFFER_TRACE(jh, "entry");
- J_ASSERT_JH(jh, buffer_dirty(jh2bh(jh)) || buffer_jbddirty(jh2bh(jh)));
- J_ASSERT_JH(jh, jh->b_cp_transaction == NULL);
-
- /* Get reference for checkpointing transaction */
- journal_grab_journal_head(jh2bh(jh));
- jh->b_cp_transaction = transaction;
-
- if (!transaction->t_checkpoint_list) {
- jh->b_cpnext = jh->b_cpprev = jh;
- } else {
- jh->b_cpnext = transaction->t_checkpoint_list;
- jh->b_cpprev = transaction->t_checkpoint_list->b_cpprev;
- jh->b_cpprev->b_cpnext = jh;
- jh->b_cpnext->b_cpprev = jh;
- }
- transaction->t_checkpoint_list = jh;
-}
-
-/*
- * We've finished with this transaction structure: adios...
- *
- * The transaction must have no links except for the checkpoint by this
- * point.
- *
- * Called with the journal locked.
- * Called with j_list_lock held.
- */
-
-void __journal_drop_transaction(journal_t *journal, transaction_t *transaction)
-{
- assert_spin_locked(&journal->j_list_lock);
- if (transaction->t_cpnext) {
- transaction->t_cpnext->t_cpprev = transaction->t_cpprev;
- transaction->t_cpprev->t_cpnext = transaction->t_cpnext;
- if (journal->j_checkpoint_transactions == transaction)
- journal->j_checkpoint_transactions =
- transaction->t_cpnext;
- if (journal->j_checkpoint_transactions == transaction)
- journal->j_checkpoint_transactions = NULL;
- }
-
- J_ASSERT(transaction->t_state == T_FINISHED);
- J_ASSERT(transaction->t_buffers == NULL);
- J_ASSERT(transaction->t_sync_datalist == NULL);
- J_ASSERT(transaction->t_forget == NULL);
- J_ASSERT(transaction->t_iobuf_list == NULL);
- J_ASSERT(transaction->t_shadow_list == NULL);
- J_ASSERT(transaction->t_log_list == NULL);
- J_ASSERT(transaction->t_checkpoint_list == NULL);
- J_ASSERT(transaction->t_checkpoint_io_list == NULL);
- J_ASSERT(transaction->t_updates == 0);
- J_ASSERT(journal->j_committing_transaction != transaction);
- J_ASSERT(journal->j_running_transaction != transaction);
-
- trace_jbd_drop_transaction(journal, transaction);
- jbd_debug(1, "Dropping transaction %d, all done\n", transaction->t_tid);
- kfree(transaction);
-}
diff --git a/kernel/fs/jbd/commit.c b/kernel/fs/jbd/commit.c
deleted file mode 100644
index bb217dcb4..000000000
--- a/kernel/fs/jbd/commit.c
+++ /dev/null
@@ -1,1021 +0,0 @@
-/*
- * linux/fs/jbd/commit.c
- *
- * Written by Stephen C. Tweedie <sct@redhat.com>, 1998
- *
- * Copyright 1998 Red Hat corp --- All Rights Reserved
- *
- * This file is part of the Linux kernel and is made available under
- * the terms of the GNU General Public License, version 2, or at your
- * option, any later version, incorporated herein by reference.
- *
- * Journal commit routines for the generic filesystem journaling code;
- * part of the ext2fs journaling system.
- */
-
-#include <linux/time.h>
-#include <linux/fs.h>
-#include <linux/jbd.h>
-#include <linux/errno.h>
-#include <linux/mm.h>
-#include <linux/pagemap.h>
-#include <linux/bio.h>
-#include <linux/blkdev.h>
-#include <trace/events/jbd.h>
-
-/*
- * Default IO end handler for temporary BJ_IO buffer_heads.
- */
-static void journal_end_buffer_io_sync(struct buffer_head *bh, int uptodate)
-{
- BUFFER_TRACE(bh, "");
- if (uptodate)
- set_buffer_uptodate(bh);
- else
- clear_buffer_uptodate(bh);
- unlock_buffer(bh);
-}
-
-/*
- * When an ext3-ordered file is truncated, it is possible that many pages are
- * not successfully freed, because they are attached to a committing transaction.
- * After the transaction commits, these pages are left on the LRU, with no
- * ->mapping, and with attached buffers. These pages are trivially reclaimable
- * by the VM, but their apparent absence upsets the VM accounting, and it makes
- * the numbers in /proc/meminfo look odd.
- *
- * So here, we have a buffer which has just come off the forget list. Look to
- * see if we can strip all buffers from the backing page.
- *
- * Called under journal->j_list_lock. The caller provided us with a ref
- * against the buffer, and we drop that here.
- */
-static void release_buffer_page(struct buffer_head *bh)
-{
- struct page *page;
-
- if (buffer_dirty(bh))
- goto nope;
- if (atomic_read(&bh->b_count) != 1)
- goto nope;
- page = bh->b_page;
- if (!page)
- goto nope;
- if (page->mapping)
- goto nope;
-
- /* OK, it's a truncated page */
- if (!trylock_page(page))
- goto nope;
-
- page_cache_get(page);
- __brelse(bh);
- try_to_free_buffers(page);
- unlock_page(page);
- page_cache_release(page);
- return;
-
-nope:
- __brelse(bh);
-}
-
-/*
- * Decrement reference counter for data buffer. If it has been marked
- * 'BH_Freed', release it and the page to which it belongs if possible.
- */
-static void release_data_buffer(struct buffer_head *bh)
-{
- if (buffer_freed(bh)) {
- WARN_ON_ONCE(buffer_dirty(bh));
- clear_buffer_freed(bh);
- clear_buffer_mapped(bh);
- clear_buffer_new(bh);
- clear_buffer_req(bh);
- bh->b_bdev = NULL;
- release_buffer_page(bh);
- } else
- put_bh(bh);
-}
-
-/*
- * Try to acquire jbd_lock_bh_state() against the buffer, when j_list_lock is
- * held. For ranking reasons we must trylock. If we lose, schedule away and
- * return 0. j_list_lock is dropped in this case.
- */
-static int inverted_lock(journal_t *journal, struct buffer_head *bh)
-{
- if (!jbd_trylock_bh_state(bh)) {
- spin_unlock(&journal->j_list_lock);
- schedule();
- return 0;
- }
- return 1;
-}
-
-/* Done it all: now write the commit record. We should have
- * cleaned up our previous buffers by now, so if we are in abort
- * mode we can now just skip the rest of the journal write
- * entirely.
- *
- * Returns 1 if the journal needs to be aborted or 0 on success
- */
-static int journal_write_commit_record(journal_t *journal,
- transaction_t *commit_transaction)
-{
- struct journal_head *descriptor;
- struct buffer_head *bh;
- journal_header_t *header;
- int ret;
-
- if (is_journal_aborted(journal))
- return 0;
-
- descriptor = journal_get_descriptor_buffer(journal);
- if (!descriptor)
- return 1;
-
- bh = jh2bh(descriptor);
-
- header = (journal_header_t *)(bh->b_data);
- header->h_magic = cpu_to_be32(JFS_MAGIC_NUMBER);
- header->h_blocktype = cpu_to_be32(JFS_COMMIT_BLOCK);
- header->h_sequence = cpu_to_be32(commit_transaction->t_tid);
-
- JBUFFER_TRACE(descriptor, "write commit block");
- set_buffer_dirty(bh);
-
- if (journal->j_flags & JFS_BARRIER)
- ret = __sync_dirty_buffer(bh, WRITE_SYNC | WRITE_FLUSH_FUA);
- else
- ret = sync_dirty_buffer(bh);
-
- put_bh(bh); /* One for getblk() */
- journal_put_journal_head(descriptor);
-
- return (ret == -EIO);
-}
-
-static void journal_do_submit_data(struct buffer_head **wbuf, int bufs,
- int write_op)
-{
- int i;
-
- for (i = 0; i < bufs; i++) {
- wbuf[i]->b_end_io = end_buffer_write_sync;
- /*
- * Here we write back pagecache data that may be mmaped. Since
- * we cannot afford to clean the page and set PageWriteback
- * here due to lock ordering (page lock ranks above transaction
- * start), the data can change while IO is in flight. Tell the
- * block layer it should bounce the bio pages if stable data
- * during write is required.
- *
- * We use up our safety reference in submit_bh().
- */
- _submit_bh(write_op, wbuf[i], 1 << BIO_SNAP_STABLE);
- }
-}
-
-/*
- * Submit all the data buffers to disk
- */
-static int journal_submit_data_buffers(journal_t *journal,
- transaction_t *commit_transaction,
- int write_op)
-{
- struct journal_head *jh;
- struct buffer_head *bh;
- int locked;
- int bufs = 0;
- struct buffer_head **wbuf = journal->j_wbuf;
- int err = 0;
-
- /*
- * Whenever we unlock the journal and sleep, things can get added
- * onto ->t_sync_datalist, so we have to keep looping back to
- * write_out_data until we *know* that the list is empty.
- *
- * Cleanup any flushed data buffers from the data list. Even in
- * abort mode, we want to flush this out as soon as possible.
- */
-write_out_data:
- cond_resched();
- spin_lock(&journal->j_list_lock);
-
- while (commit_transaction->t_sync_datalist) {
- jh = commit_transaction->t_sync_datalist;
- bh = jh2bh(jh);
- locked = 0;
-
- /* Get reference just to make sure buffer does not disappear
- * when we are forced to drop various locks */
- get_bh(bh);
- /* If the buffer is dirty, we need to submit IO and hence
- * we need the buffer lock. We try to lock the buffer without
- * blocking. If we fail, we need to drop j_list_lock and do
- * blocking lock_buffer().
- */
- if (buffer_dirty(bh)) {
- if (!trylock_buffer(bh)) {
- BUFFER_TRACE(bh, "needs blocking lock");
- spin_unlock(&journal->j_list_lock);
- trace_jbd_do_submit_data(journal,
- commit_transaction);
- /* Write out all data to prevent deadlocks */
- journal_do_submit_data(wbuf, bufs, write_op);
- bufs = 0;
- lock_buffer(bh);
- spin_lock(&journal->j_list_lock);
- }
- locked = 1;
- }
- /* We have to get bh_state lock. Again out of order, sigh. */
- if (!inverted_lock(journal, bh)) {
- jbd_lock_bh_state(bh);
- spin_lock(&journal->j_list_lock);
- }
- /* Someone already cleaned up the buffer? */
- if (!buffer_jbd(bh) || bh2jh(bh) != jh
- || jh->b_transaction != commit_transaction
- || jh->b_jlist != BJ_SyncData) {
- jbd_unlock_bh_state(bh);
- if (locked)
- unlock_buffer(bh);
- BUFFER_TRACE(bh, "already cleaned up");
- release_data_buffer(bh);
- continue;
- }
- if (locked && test_clear_buffer_dirty(bh)) {
- BUFFER_TRACE(bh, "needs writeout, adding to array");
- wbuf[bufs++] = bh;
- __journal_file_buffer(jh, commit_transaction,
- BJ_Locked);
- jbd_unlock_bh_state(bh);
- if (bufs == journal->j_wbufsize) {
- spin_unlock(&journal->j_list_lock);
- trace_jbd_do_submit_data(journal,
- commit_transaction);
- journal_do_submit_data(wbuf, bufs, write_op);
- bufs = 0;
- goto write_out_data;
- }
- } else if (!locked && buffer_locked(bh)) {
- __journal_file_buffer(jh, commit_transaction,
- BJ_Locked);
- jbd_unlock_bh_state(bh);
- put_bh(bh);
- } else {
- BUFFER_TRACE(bh, "writeout complete: unfile");
- if (unlikely(!buffer_uptodate(bh)))
- err = -EIO;
- __journal_unfile_buffer(jh);
- jbd_unlock_bh_state(bh);
- if (locked)
- unlock_buffer(bh);
- release_data_buffer(bh);
- }
-
- if (need_resched() || spin_needbreak(&journal->j_list_lock)) {
- spin_unlock(&journal->j_list_lock);
- goto write_out_data;
- }
- }
- spin_unlock(&journal->j_list_lock);
- trace_jbd_do_submit_data(journal, commit_transaction);
- journal_do_submit_data(wbuf, bufs, write_op);
-
- return err;
-}
-
-/*
- * journal_commit_transaction
- *
- * The primary function for committing a transaction to the log. This
- * function is called by the journal thread to begin a complete commit.
- */
-void journal_commit_transaction(journal_t *journal)
-{
- transaction_t *commit_transaction;
- struct journal_head *jh, *new_jh, *descriptor;
- struct buffer_head **wbuf = journal->j_wbuf;
- int bufs;
- int flags;
- int err;
- unsigned int blocknr;
- ktime_t start_time;
- u64 commit_time;
- char *tagp = NULL;
- journal_header_t *header;
- journal_block_tag_t *tag = NULL;
- int space_left = 0;
- int first_tag = 0;
- int tag_flag;
- int i;
- struct blk_plug plug;
- int write_op = WRITE;
-
- /*
- * First job: lock down the current transaction and wait for
- * all outstanding updates to complete.
- */
-
- /* Do we need to erase the effects of a prior journal_flush? */
- if (journal->j_flags & JFS_FLUSHED) {
- jbd_debug(3, "super block updated\n");
- mutex_lock(&journal->j_checkpoint_mutex);
- /*
- * We hold j_checkpoint_mutex so tail cannot change under us.
- * We don't need any special data guarantees for writing sb
- * since journal is empty and it is ok for write to be
- * flushed only with transaction commit.
- */
- journal_update_sb_log_tail(journal, journal->j_tail_sequence,
- journal->j_tail, WRITE_SYNC);
- mutex_unlock(&journal->j_checkpoint_mutex);
- } else {
- jbd_debug(3, "superblock not updated\n");
- }
-
- J_ASSERT(journal->j_running_transaction != NULL);
- J_ASSERT(journal->j_committing_transaction == NULL);
-
- commit_transaction = journal->j_running_transaction;
-
- trace_jbd_start_commit(journal, commit_transaction);
- jbd_debug(1, "JBD: starting commit of transaction %d\n",
- commit_transaction->t_tid);
-
- spin_lock(&journal->j_state_lock);
- J_ASSERT(commit_transaction->t_state == T_RUNNING);
- commit_transaction->t_state = T_LOCKED;
-
- trace_jbd_commit_locking(journal, commit_transaction);
- spin_lock(&commit_transaction->t_handle_lock);
- while (commit_transaction->t_updates) {
- DEFINE_WAIT(wait);
-
- prepare_to_wait(&journal->j_wait_updates, &wait,
- TASK_UNINTERRUPTIBLE);
- if (commit_transaction->t_updates) {
- spin_unlock(&commit_transaction->t_handle_lock);
- spin_unlock(&journal->j_state_lock);
- schedule();
- spin_lock(&journal->j_state_lock);
- spin_lock(&commit_transaction->t_handle_lock);
- }
- finish_wait(&journal->j_wait_updates, &wait);
- }
- spin_unlock(&commit_transaction->t_handle_lock);
-
- J_ASSERT (commit_transaction->t_outstanding_credits <=
- journal->j_max_transaction_buffers);
-
- /*
- * First thing we are allowed to do is to discard any remaining
- * BJ_Reserved buffers. Note, it is _not_ permissible to assume
- * that there are no such buffers: if a large filesystem
- * operation like a truncate needs to split itself over multiple
- * transactions, then it may try to do a journal_restart() while
- * there are still BJ_Reserved buffers outstanding. These must
- * be released cleanly from the current transaction.
- *
- * In this case, the filesystem must still reserve write access
- * again before modifying the buffer in the new transaction, but
- * we do not require it to remember exactly which old buffers it
- * has reserved. This is consistent with the existing behaviour
- * that multiple journal_get_write_access() calls to the same
- * buffer are perfectly permissible.
- */
- while (commit_transaction->t_reserved_list) {
- jh = commit_transaction->t_reserved_list;
- JBUFFER_TRACE(jh, "reserved, unused: refile");
- /*
- * A journal_get_undo_access()+journal_release_buffer() may
- * leave undo-committed data.
- */
- if (jh->b_committed_data) {
- struct buffer_head *bh = jh2bh(jh);
-
- jbd_lock_bh_state(bh);
- jbd_free(jh->b_committed_data, bh->b_size);
- jh->b_committed_data = NULL;
- jbd_unlock_bh_state(bh);
- }
- journal_refile_buffer(journal, jh);
- }
-
- /*
- * Now try to drop any written-back buffers from the journal's
- * checkpoint lists. We do this *before* commit because it potentially
- * frees some memory
- */
- spin_lock(&journal->j_list_lock);
- __journal_clean_checkpoint_list(journal);
- spin_unlock(&journal->j_list_lock);
-
- jbd_debug (3, "JBD: commit phase 1\n");
-
- /*
- * Clear revoked flag to reflect there is no revoked buffers
- * in the next transaction which is going to be started.
- */
- journal_clear_buffer_revoked_flags(journal);
-
- /*
- * Switch to a new revoke table.
- */
- journal_switch_revoke_table(journal);
-
- trace_jbd_commit_flushing(journal, commit_transaction);
- commit_transaction->t_state = T_FLUSH;
- journal->j_committing_transaction = commit_transaction;
- journal->j_running_transaction = NULL;
- start_time = ktime_get();
- commit_transaction->t_log_start = journal->j_head;
- wake_up(&journal->j_wait_transaction_locked);
- spin_unlock(&journal->j_state_lock);
-
- jbd_debug (3, "JBD: commit phase 2\n");
-
- if (tid_geq(journal->j_commit_waited, commit_transaction->t_tid))
- write_op = WRITE_SYNC;
-
- /*
- * Now start flushing things to disk, in the order they appear
- * on the transaction lists. Data blocks go first.
- */
- blk_start_plug(&plug);
- err = journal_submit_data_buffers(journal, commit_transaction,
- write_op);
- blk_finish_plug(&plug);
-
- /*
- * Wait for all previously submitted IO to complete.
- */
- spin_lock(&journal->j_list_lock);
- while (commit_transaction->t_locked_list) {
- struct buffer_head *bh;
-
- jh = commit_transaction->t_locked_list->b_tprev;
- bh = jh2bh(jh);
- get_bh(bh);
- if (buffer_locked(bh)) {
- spin_unlock(&journal->j_list_lock);
- wait_on_buffer(bh);
- spin_lock(&journal->j_list_lock);
- }
- if (unlikely(!buffer_uptodate(bh))) {
- if (!trylock_page(bh->b_page)) {
- spin_unlock(&journal->j_list_lock);
- lock_page(bh->b_page);
- spin_lock(&journal->j_list_lock);
- }
- if (bh->b_page->mapping)
- set_bit(AS_EIO, &bh->b_page->mapping->flags);
-
- unlock_page(bh->b_page);
- SetPageError(bh->b_page);
- err = -EIO;
- }
- if (!inverted_lock(journal, bh)) {
- put_bh(bh);
- spin_lock(&journal->j_list_lock);
- continue;
- }
- if (buffer_jbd(bh) && bh2jh(bh) == jh &&
- jh->b_transaction == commit_transaction &&
- jh->b_jlist == BJ_Locked)
- __journal_unfile_buffer(jh);
- jbd_unlock_bh_state(bh);
- release_data_buffer(bh);
- cond_resched_lock(&journal->j_list_lock);
- }
- spin_unlock(&journal->j_list_lock);
-
- if (err) {
- char b[BDEVNAME_SIZE];
-
- printk(KERN_WARNING
- "JBD: Detected IO errors while flushing file data "
- "on %s\n", bdevname(journal->j_fs_dev, b));
- if (journal->j_flags & JFS_ABORT_ON_SYNCDATA_ERR)
- journal_abort(journal, err);
- err = 0;
- }
-
- blk_start_plug(&plug);
-
- journal_write_revoke_records(journal, commit_transaction, write_op);
-
- /*
- * If we found any dirty or locked buffers, then we should have
- * looped back up to the write_out_data label. If there weren't
- * any then journal_clean_data_list should have wiped the list
- * clean by now, so check that it is in fact empty.
- */
- J_ASSERT (commit_transaction->t_sync_datalist == NULL);
-
- jbd_debug (3, "JBD: commit phase 3\n");
-
- /*
- * Way to go: we have now written out all of the data for a
- * transaction! Now comes the tricky part: we need to write out
- * metadata. Loop over the transaction's entire buffer list:
- */
- spin_lock(&journal->j_state_lock);
- commit_transaction->t_state = T_COMMIT;
- spin_unlock(&journal->j_state_lock);
-
- trace_jbd_commit_logging(journal, commit_transaction);
- J_ASSERT(commit_transaction->t_nr_buffers <=
- commit_transaction->t_outstanding_credits);
-
- descriptor = NULL;
- bufs = 0;
- while (commit_transaction->t_buffers) {
-
- /* Find the next buffer to be journaled... */
-
- jh = commit_transaction->t_buffers;
-
- /* If we're in abort mode, we just un-journal the buffer and
- release it. */
-
- if (is_journal_aborted(journal)) {
- clear_buffer_jbddirty(jh2bh(jh));
- JBUFFER_TRACE(jh, "journal is aborting: refile");
- journal_refile_buffer(journal, jh);
- /* If that was the last one, we need to clean up
- * any descriptor buffers which may have been
- * already allocated, even if we are now
- * aborting. */
- if (!commit_transaction->t_buffers)
- goto start_journal_io;
- continue;
- }
-
- /* Make sure we have a descriptor block in which to
- record the metadata buffer. */
-
- if (!descriptor) {
- struct buffer_head *bh;
-
- J_ASSERT (bufs == 0);
-
- jbd_debug(4, "JBD: get descriptor\n");
-
- descriptor = journal_get_descriptor_buffer(journal);
- if (!descriptor) {
- journal_abort(journal, -EIO);
- continue;
- }
-
- bh = jh2bh(descriptor);
- jbd_debug(4, "JBD: got buffer %llu (%p)\n",
- (unsigned long long)bh->b_blocknr, bh->b_data);
- header = (journal_header_t *)&bh->b_data[0];
- header->h_magic = cpu_to_be32(JFS_MAGIC_NUMBER);
- header->h_blocktype = cpu_to_be32(JFS_DESCRIPTOR_BLOCK);
- header->h_sequence = cpu_to_be32(commit_transaction->t_tid);
-
- tagp = &bh->b_data[sizeof(journal_header_t)];
- space_left = bh->b_size - sizeof(journal_header_t);
- first_tag = 1;
- set_buffer_jwrite(bh);
- set_buffer_dirty(bh);
- wbuf[bufs++] = bh;
-
- /* Record it so that we can wait for IO
- completion later */
- BUFFER_TRACE(bh, "ph3: file as descriptor");
- journal_file_buffer(descriptor, commit_transaction,
- BJ_LogCtl);
- }
-
- /* Where is the buffer to be written? */
-
- err = journal_next_log_block(journal, &blocknr);
- /* If the block mapping failed, just abandon the buffer
- and repeat this loop: we'll fall into the
- refile-on-abort condition above. */
- if (err) {
- journal_abort(journal, err);
- continue;
- }
-
- /*
- * start_this_handle() uses t_outstanding_credits to determine
- * the free space in the log, but this counter is changed
- * by journal_next_log_block() also.
- */
- commit_transaction->t_outstanding_credits--;
-
- /* Bump b_count to prevent truncate from stumbling over
- the shadowed buffer! @@@ This can go if we ever get
- rid of the BJ_IO/BJ_Shadow pairing of buffers. */
- get_bh(jh2bh(jh));
-
- /* Make a temporary IO buffer with which to write it out
- (this will requeue both the metadata buffer and the
- temporary IO buffer). new_bh goes on BJ_IO*/
-
- set_buffer_jwrite(jh2bh(jh));
- /*
- * akpm: journal_write_metadata_buffer() sets
- * new_bh->b_transaction to commit_transaction.
- * We need to clean this up before we release new_bh
- * (which is of type BJ_IO)
- */
- JBUFFER_TRACE(jh, "ph3: write metadata");
- flags = journal_write_metadata_buffer(commit_transaction,
- jh, &new_jh, blocknr);
- set_buffer_jwrite(jh2bh(new_jh));
- wbuf[bufs++] = jh2bh(new_jh);
-
- /* Record the new block's tag in the current descriptor
- buffer */
-
- tag_flag = 0;
- if (flags & 1)
- tag_flag |= JFS_FLAG_ESCAPE;
- if (!first_tag)
- tag_flag |= JFS_FLAG_SAME_UUID;
-
- tag = (journal_block_tag_t *) tagp;
- tag->t_blocknr = cpu_to_be32(jh2bh(jh)->b_blocknr);
- tag->t_flags = cpu_to_be32(tag_flag);
- tagp += sizeof(journal_block_tag_t);
- space_left -= sizeof(journal_block_tag_t);
-
- if (first_tag) {
- memcpy (tagp, journal->j_uuid, 16);
- tagp += 16;
- space_left -= 16;
- first_tag = 0;
- }
-
- /* If there's no more to do, or if the descriptor is full,
- let the IO rip! */
-
- if (bufs == journal->j_wbufsize ||
- commit_transaction->t_buffers == NULL ||
- space_left < sizeof(journal_block_tag_t) + 16) {
-
- jbd_debug(4, "JBD: Submit %d IOs\n", bufs);
-
- /* Write an end-of-descriptor marker before
- submitting the IOs. "tag" still points to
- the last tag we set up. */
-
- tag->t_flags |= cpu_to_be32(JFS_FLAG_LAST_TAG);
-
-start_journal_io:
- for (i = 0; i < bufs; i++) {
- struct buffer_head *bh = wbuf[i];
- lock_buffer(bh);
- clear_buffer_dirty(bh);
- set_buffer_uptodate(bh);
- bh->b_end_io = journal_end_buffer_io_sync;
- /*
- * In data=journal mode, here we can end up
- * writing pagecache data that might be
- * mmapped. Since we can't afford to clean the
- * page and set PageWriteback (see the comment
- * near the other use of _submit_bh()), the
- * data can change while the write is in
- * flight. Tell the block layer to bounce the
- * bio pages if stable pages are required.
- */
- _submit_bh(write_op, bh, 1 << BIO_SNAP_STABLE);
- }
- cond_resched();
-
- /* Force a new descriptor to be generated next
- time round the loop. */
- descriptor = NULL;
- bufs = 0;
- }
- }
-
- blk_finish_plug(&plug);
-
- /* Lo and behold: we have just managed to send a transaction to
- the log. Before we can commit it, wait for the IO so far to
- complete. Control buffers being written are on the
- transaction's t_log_list queue, and metadata buffers are on
- the t_iobuf_list queue.
-
- Wait for the buffers in reverse order. That way we are
- less likely to be woken up until all IOs have completed, and
- so we incur less scheduling load.
- */
-
- jbd_debug(3, "JBD: commit phase 4\n");
-
- /*
- * akpm: these are BJ_IO, and j_list_lock is not needed.
- * See __journal_try_to_free_buffer.
- */
-wait_for_iobuf:
- while (commit_transaction->t_iobuf_list != NULL) {
- struct buffer_head *bh;
-
- jh = commit_transaction->t_iobuf_list->b_tprev;
- bh = jh2bh(jh);
- if (buffer_locked(bh)) {
- wait_on_buffer(bh);
- goto wait_for_iobuf;
- }
- if (cond_resched())
- goto wait_for_iobuf;
-
- if (unlikely(!buffer_uptodate(bh)))
- err = -EIO;
-
- clear_buffer_jwrite(bh);
-
- JBUFFER_TRACE(jh, "ph4: unfile after journal write");
- journal_unfile_buffer(journal, jh);
-
- /*
- * ->t_iobuf_list should contain only dummy buffer_heads
- * which were created by journal_write_metadata_buffer().
- */
- BUFFER_TRACE(bh, "dumping temporary bh");
- journal_put_journal_head(jh);
- __brelse(bh);
- J_ASSERT_BH(bh, atomic_read(&bh->b_count) == 0);
- free_buffer_head(bh);
-
- /* We also have to unlock and free the corresponding
- shadowed buffer */
- jh = commit_transaction->t_shadow_list->b_tprev;
- bh = jh2bh(jh);
- clear_buffer_jwrite(bh);
- J_ASSERT_BH(bh, buffer_jbddirty(bh));
-
- /* The metadata is now released for reuse, but we need
- to remember it against this transaction so that when
- we finally commit, we can do any checkpointing
- required. */
- JBUFFER_TRACE(jh, "file as BJ_Forget");
- journal_file_buffer(jh, commit_transaction, BJ_Forget);
- /*
- * Wake up any transactions which were waiting for this
- * IO to complete. The barrier must be here so that changes
- * by journal_file_buffer() take effect before wake_up_bit()
- * does the waitqueue check.
- */
- smp_mb();
- wake_up_bit(&bh->b_state, BH_Unshadow);
- JBUFFER_TRACE(jh, "brelse shadowed buffer");
- __brelse(bh);
- }
-
- J_ASSERT (commit_transaction->t_shadow_list == NULL);
-
- jbd_debug(3, "JBD: commit phase 5\n");
-
- /* Here we wait for the revoke record and descriptor record buffers */
- wait_for_ctlbuf:
- while (commit_transaction->t_log_list != NULL) {
- struct buffer_head *bh;
-
- jh = commit_transaction->t_log_list->b_tprev;
- bh = jh2bh(jh);
- if (buffer_locked(bh)) {
- wait_on_buffer(bh);
- goto wait_for_ctlbuf;
- }
- if (cond_resched())
- goto wait_for_ctlbuf;
-
- if (unlikely(!buffer_uptodate(bh)))
- err = -EIO;
-
- BUFFER_TRACE(bh, "ph5: control buffer writeout done: unfile");
- clear_buffer_jwrite(bh);
- journal_unfile_buffer(journal, jh);
- journal_put_journal_head(jh);
- __brelse(bh); /* One for getblk */
- /* AKPM: bforget here */
- }
-
- if (err)
- journal_abort(journal, err);
-
- jbd_debug(3, "JBD: commit phase 6\n");
-
- /* All metadata is written, now write commit record and do cleanup */
- spin_lock(&journal->j_state_lock);
- J_ASSERT(commit_transaction->t_state == T_COMMIT);
- commit_transaction->t_state = T_COMMIT_RECORD;
- spin_unlock(&journal->j_state_lock);
-
- if (journal_write_commit_record(journal, commit_transaction))
- err = -EIO;
-
- if (err)
- journal_abort(journal, err);
-
- /* End of a transaction! Finally, we can do checkpoint
- processing: any buffers committed as a result of this
- transaction can be removed from any checkpoint list it was on
- before. */
-
- jbd_debug(3, "JBD: commit phase 7\n");
-
- J_ASSERT(commit_transaction->t_sync_datalist == NULL);
- J_ASSERT(commit_transaction->t_buffers == NULL);
- J_ASSERT(commit_transaction->t_checkpoint_list == NULL);
- J_ASSERT(commit_transaction->t_iobuf_list == NULL);
- J_ASSERT(commit_transaction->t_shadow_list == NULL);
- J_ASSERT(commit_transaction->t_log_list == NULL);
-
-restart_loop:
- /*
- * As there are other places (journal_unmap_buffer()) adding buffers
- * to this list we have to be careful and hold the j_list_lock.
- */
- spin_lock(&journal->j_list_lock);
- while (commit_transaction->t_forget) {
- transaction_t *cp_transaction;
- struct buffer_head *bh;
- int try_to_free = 0;
-
- jh = commit_transaction->t_forget;
- spin_unlock(&journal->j_list_lock);
- bh = jh2bh(jh);
- /*
- * Get a reference so that bh cannot be freed before we are
- * done with it.
- */
- get_bh(bh);
- jbd_lock_bh_state(bh);
- J_ASSERT_JH(jh, jh->b_transaction == commit_transaction ||
- jh->b_transaction == journal->j_running_transaction);
-
- /*
- * If there is undo-protected committed data against
- * this buffer, then we can remove it now. If it is a
- * buffer needing such protection, the old frozen_data
- * field now points to a committed version of the
- * buffer, so rotate that field to the new committed
- * data.
- *
- * Otherwise, we can just throw away the frozen data now.
- */
- if (jh->b_committed_data) {
- jbd_free(jh->b_committed_data, bh->b_size);
- jh->b_committed_data = NULL;
- if (jh->b_frozen_data) {
- jh->b_committed_data = jh->b_frozen_data;
- jh->b_frozen_data = NULL;
- }
- } else if (jh->b_frozen_data) {
- jbd_free(jh->b_frozen_data, bh->b_size);
- jh->b_frozen_data = NULL;
- }
-
- spin_lock(&journal->j_list_lock);
- cp_transaction = jh->b_cp_transaction;
- if (cp_transaction) {
- JBUFFER_TRACE(jh, "remove from old cp transaction");
- __journal_remove_checkpoint(jh);
- }
-
- /* Only re-checkpoint the buffer_head if it is marked
- * dirty. If the buffer was added to the BJ_Forget list
- * by journal_forget, it may no longer be dirty and
- * there's no point in keeping a checkpoint record for
- * it. */
-
- /*
- * A buffer which has been freed while still being journaled by
- * a previous transaction.
- */
- if (buffer_freed(bh)) {
- /*
- * If the running transaction is the one containing
- * "add to orphan" operation (b_next_transaction !=
- * NULL), we have to wait for that transaction to
- * commit before we can really get rid of the buffer.
- * So just clear b_modified to not confuse transaction
- * credit accounting and refile the buffer to
- * BJ_Forget of the running transaction. If the just
- * committed transaction contains "add to orphan"
- * operation, we can completely invalidate the buffer
- * now. We are rather throughout in that since the
- * buffer may be still accessible when blocksize <
- * pagesize and it is attached to the last partial
- * page.
- */
- jh->b_modified = 0;
- if (!jh->b_next_transaction) {
- clear_buffer_freed(bh);
- clear_buffer_jbddirty(bh);
- clear_buffer_mapped(bh);
- clear_buffer_new(bh);
- clear_buffer_req(bh);
- bh->b_bdev = NULL;
- }
- }
-
- if (buffer_jbddirty(bh)) {
- JBUFFER_TRACE(jh, "add to new checkpointing trans");
- __journal_insert_checkpoint(jh, commit_transaction);
- if (is_journal_aborted(journal))
- clear_buffer_jbddirty(bh);
- } else {
- J_ASSERT_BH(bh, !buffer_dirty(bh));
- /*
- * The buffer on BJ_Forget list and not jbddirty means
- * it has been freed by this transaction and hence it
- * could not have been reallocated until this
- * transaction has committed. *BUT* it could be
- * reallocated once we have written all the data to
- * disk and before we process the buffer on BJ_Forget
- * list.
- */
- if (!jh->b_next_transaction)
- try_to_free = 1;
- }
- JBUFFER_TRACE(jh, "refile or unfile freed buffer");
- __journal_refile_buffer(jh);
- jbd_unlock_bh_state(bh);
- if (try_to_free)
- release_buffer_page(bh);
- else
- __brelse(bh);
- cond_resched_lock(&journal->j_list_lock);
- }
- spin_unlock(&journal->j_list_lock);
- /*
- * This is a bit sleazy. We use j_list_lock to protect transition
- * of a transaction into T_FINISHED state and calling
- * __journal_drop_transaction(). Otherwise we could race with
- * other checkpointing code processing the transaction...
- */
- spin_lock(&journal->j_state_lock);
- spin_lock(&journal->j_list_lock);
- /*
- * Now recheck if some buffers did not get attached to the transaction
- * while the lock was dropped...
- */
- if (commit_transaction->t_forget) {
- spin_unlock(&journal->j_list_lock);
- spin_unlock(&journal->j_state_lock);
- goto restart_loop;
- }
-
- /* Done with this transaction! */
-
- jbd_debug(3, "JBD: commit phase 8\n");
-
- J_ASSERT(commit_transaction->t_state == T_COMMIT_RECORD);
-
- commit_transaction->t_state = T_FINISHED;
- J_ASSERT(commit_transaction == journal->j_committing_transaction);
- journal->j_commit_sequence = commit_transaction->t_tid;
- journal->j_committing_transaction = NULL;
- commit_time = ktime_to_ns(ktime_sub(ktime_get(), start_time));
-
- /*
- * weight the commit time higher than the average time so we don't
- * react too strongly to vast changes in commit time
- */
- if (likely(journal->j_average_commit_time))
- journal->j_average_commit_time = (commit_time*3 +
- journal->j_average_commit_time) / 4;
- else
- journal->j_average_commit_time = commit_time;
-
- spin_unlock(&journal->j_state_lock);
-
- if (commit_transaction->t_checkpoint_list == NULL &&
- commit_transaction->t_checkpoint_io_list == NULL) {
- __journal_drop_transaction(journal, commit_transaction);
- } else {
- if (journal->j_checkpoint_transactions == NULL) {
- journal->j_checkpoint_transactions = commit_transaction;
- commit_transaction->t_cpnext = commit_transaction;
- commit_transaction->t_cpprev = commit_transaction;
- } else {
- commit_transaction->t_cpnext =
- journal->j_checkpoint_transactions;
- commit_transaction->t_cpprev =
- commit_transaction->t_cpnext->t_cpprev;
- commit_transaction->t_cpnext->t_cpprev =
- commit_transaction;
- commit_transaction->t_cpprev->t_cpnext =
- commit_transaction;
- }
- }
- spin_unlock(&journal->j_list_lock);
-
- trace_jbd_end_commit(journal, commit_transaction);
- jbd_debug(1, "JBD: commit %d complete, head %d\n",
- journal->j_commit_sequence, journal->j_tail_sequence);
-
- wake_up(&journal->j_wait_done_commit);
-}
diff --git a/kernel/fs/jbd/journal.c b/kernel/fs/jbd/journal.c
deleted file mode 100644
index c46a79adb..000000000
--- a/kernel/fs/jbd/journal.c
+++ /dev/null
@@ -1,2145 +0,0 @@
-/*
- * linux/fs/jbd/journal.c
- *
- * Written by Stephen C. Tweedie <sct@redhat.com>, 1998
- *
- * Copyright 1998 Red Hat corp --- All Rights Reserved
- *
- * This file is part of the Linux kernel and is made available under
- * the terms of the GNU General Public License, version 2, or at your
- * option, any later version, incorporated herein by reference.
- *
- * Generic filesystem journal-writing code; part of the ext2fs
- * journaling system.
- *
- * This file manages journals: areas of disk reserved for logging
- * transactional updates. This includes the kernel journaling thread
- * which is responsible for scheduling updates to the log.
- *
- * We do not actually manage the physical storage of the journal in this
- * file: that is left to a per-journal policy function, which allows us
- * to store the journal within a filesystem-specified area for ext2
- * journaling (ext2 can use a reserved inode for storing the log).
- */
-
-#include <linux/module.h>
-#include <linux/time.h>
-#include <linux/fs.h>
-#include <linux/jbd.h>
-#include <linux/errno.h>
-#include <linux/slab.h>
-#include <linux/init.h>
-#include <linux/mm.h>
-#include <linux/freezer.h>
-#include <linux/pagemap.h>
-#include <linux/kthread.h>
-#include <linux/poison.h>
-#include <linux/proc_fs.h>
-#include <linux/debugfs.h>
-#include <linux/ratelimit.h>
-
-#define CREATE_TRACE_POINTS
-#include <trace/events/jbd.h>
-
-#include <asm/uaccess.h>
-#include <asm/page.h>
-
-EXPORT_SYMBOL(journal_start);
-EXPORT_SYMBOL(journal_restart);
-EXPORT_SYMBOL(journal_extend);
-EXPORT_SYMBOL(journal_stop);
-EXPORT_SYMBOL(journal_lock_updates);
-EXPORT_SYMBOL(journal_unlock_updates);
-EXPORT_SYMBOL(journal_get_write_access);
-EXPORT_SYMBOL(journal_get_create_access);
-EXPORT_SYMBOL(journal_get_undo_access);
-EXPORT_SYMBOL(journal_dirty_data);
-EXPORT_SYMBOL(journal_dirty_metadata);
-EXPORT_SYMBOL(journal_release_buffer);
-EXPORT_SYMBOL(journal_forget);
-#if 0
-EXPORT_SYMBOL(journal_sync_buffer);
-#endif
-EXPORT_SYMBOL(journal_flush);
-EXPORT_SYMBOL(journal_revoke);
-
-EXPORT_SYMBOL(journal_init_dev);
-EXPORT_SYMBOL(journal_init_inode);
-EXPORT_SYMBOL(journal_update_format);
-EXPORT_SYMBOL(journal_check_used_features);
-EXPORT_SYMBOL(journal_check_available_features);
-EXPORT_SYMBOL(journal_set_features);
-EXPORT_SYMBOL(journal_create);
-EXPORT_SYMBOL(journal_load);
-EXPORT_SYMBOL(journal_destroy);
-EXPORT_SYMBOL(journal_abort);
-EXPORT_SYMBOL(journal_errno);
-EXPORT_SYMBOL(journal_ack_err);
-EXPORT_SYMBOL(journal_clear_err);
-EXPORT_SYMBOL(log_wait_commit);
-EXPORT_SYMBOL(log_start_commit);
-EXPORT_SYMBOL(journal_start_commit);
-EXPORT_SYMBOL(journal_force_commit_nested);
-EXPORT_SYMBOL(journal_wipe);
-EXPORT_SYMBOL(journal_blocks_per_page);
-EXPORT_SYMBOL(journal_invalidatepage);
-EXPORT_SYMBOL(journal_try_to_free_buffers);
-EXPORT_SYMBOL(journal_force_commit);
-
-static int journal_convert_superblock_v1(journal_t *, journal_superblock_t *);
-static void __journal_abort_soft (journal_t *journal, int errno);
-static const char *journal_dev_name(journal_t *journal, char *buffer);
-
-#ifdef CONFIG_JBD_DEBUG
-void __jbd_debug(int level, const char *file, const char *func,
- unsigned int line, const char *fmt, ...)
-{
- struct va_format vaf;
- va_list args;
-
- if (level > journal_enable_debug)
- return;
- va_start(args, fmt);
- vaf.fmt = fmt;
- vaf.va = &args;
- printk(KERN_DEBUG "%s: (%s, %u): %pV\n", file, func, line, &vaf);
- va_end(args);
-}
-EXPORT_SYMBOL(__jbd_debug);
-#endif
-
-/*
- * Helper function used to manage commit timeouts
- */
-
-static void commit_timeout(unsigned long __data)
-{
- struct task_struct * p = (struct task_struct *) __data;
-
- wake_up_process(p);
-}
-
-/*
- * kjournald: The main thread function used to manage a logging device
- * journal.
- *
- * This kernel thread is responsible for two things:
- *
- * 1) COMMIT: Every so often we need to commit the current state of the
- * filesystem to disk. The journal thread is responsible for writing
- * all of the metadata buffers to disk.
- *
- * 2) CHECKPOINT: We cannot reuse a used section of the log file until all
- * of the data in that part of the log has been rewritten elsewhere on
- * the disk. Flushing these old buffers to reclaim space in the log is
- * known as checkpointing, and this thread is responsible for that job.
- */
-
-static int kjournald(void *arg)
-{
- journal_t *journal = arg;
- transaction_t *transaction;
-
- /*
- * Set up an interval timer which can be used to trigger a commit wakeup
- * after the commit interval expires
- */
- setup_timer(&journal->j_commit_timer, commit_timeout,
- (unsigned long)current);
-
- set_freezable();
-
- /* Record that the journal thread is running */
- journal->j_task = current;
- wake_up(&journal->j_wait_done_commit);
-
- printk(KERN_INFO "kjournald starting. Commit interval %ld seconds\n",
- journal->j_commit_interval / HZ);
-
- /*
- * And now, wait forever for commit wakeup events.
- */
- spin_lock(&journal->j_state_lock);
-
-loop:
- if (journal->j_flags & JFS_UNMOUNT)
- goto end_loop;
-
- jbd_debug(1, "commit_sequence=%d, commit_request=%d\n",
- journal->j_commit_sequence, journal->j_commit_request);
-
- if (journal->j_commit_sequence != journal->j_commit_request) {
- jbd_debug(1, "OK, requests differ\n");
- spin_unlock(&journal->j_state_lock);
- del_timer_sync(&journal->j_commit_timer);
- journal_commit_transaction(journal);
- spin_lock(&journal->j_state_lock);
- goto loop;
- }
-
- wake_up(&journal->j_wait_done_commit);
- if (freezing(current)) {
- /*
- * The simpler the better. Flushing journal isn't a
- * good idea, because that depends on threads that may
- * be already stopped.
- */
- jbd_debug(1, "Now suspending kjournald\n");
- spin_unlock(&journal->j_state_lock);
- try_to_freeze();
- spin_lock(&journal->j_state_lock);
- } else {
- /*
- * We assume on resume that commits are already there,
- * so we don't sleep
- */
- DEFINE_WAIT(wait);
- int should_sleep = 1;
-
- prepare_to_wait(&journal->j_wait_commit, &wait,
- TASK_INTERRUPTIBLE);
- if (journal->j_commit_sequence != journal->j_commit_request)
- should_sleep = 0;
- transaction = journal->j_running_transaction;
- if (transaction && time_after_eq(jiffies,
- transaction->t_expires))
- should_sleep = 0;
- if (journal->j_flags & JFS_UNMOUNT)
- should_sleep = 0;
- if (should_sleep) {
- spin_unlock(&journal->j_state_lock);
- schedule();
- spin_lock(&journal->j_state_lock);
- }
- finish_wait(&journal->j_wait_commit, &wait);
- }
-
- jbd_debug(1, "kjournald wakes\n");
-
- /*
- * Were we woken up by a commit wakeup event?
- */
- transaction = journal->j_running_transaction;
- if (transaction && time_after_eq(jiffies, transaction->t_expires)) {
- journal->j_commit_request = transaction->t_tid;
- jbd_debug(1, "woke because of timeout\n");
- }
- goto loop;
-
-end_loop:
- spin_unlock(&journal->j_state_lock);
- del_timer_sync(&journal->j_commit_timer);
- journal->j_task = NULL;
- wake_up(&journal->j_wait_done_commit);
- jbd_debug(1, "Journal thread exiting.\n");
- return 0;
-}
-
-static int journal_start_thread(journal_t *journal)
-{
- struct task_struct *t;
-
- t = kthread_run(kjournald, journal, "kjournald");
- if (IS_ERR(t))
- return PTR_ERR(t);
-
- wait_event(journal->j_wait_done_commit, journal->j_task != NULL);
- return 0;
-}
-
-static void journal_kill_thread(journal_t *journal)
-{
- spin_lock(&journal->j_state_lock);
- journal->j_flags |= JFS_UNMOUNT;
-
- while (journal->j_task) {
- wake_up(&journal->j_wait_commit);
- spin_unlock(&journal->j_state_lock);
- wait_event(journal->j_wait_done_commit,
- journal->j_task == NULL);
- spin_lock(&journal->j_state_lock);
- }
- spin_unlock(&journal->j_state_lock);
-}
-
-/*
- * journal_write_metadata_buffer: write a metadata buffer to the journal.
- *
- * Writes a metadata buffer to a given disk block. The actual IO is not
- * performed but a new buffer_head is constructed which labels the data
- * to be written with the correct destination disk block.
- *
- * Any magic-number escaping which needs to be done will cause a
- * copy-out here. If the buffer happens to start with the
- * JFS_MAGIC_NUMBER, then we can't write it to the log directly: the
- * magic number is only written to the log for descripter blocks. In
- * this case, we copy the data and replace the first word with 0, and we
- * return a result code which indicates that this buffer needs to be
- * marked as an escaped buffer in the corresponding log descriptor
- * block. The missing word can then be restored when the block is read
- * during recovery.
- *
- * If the source buffer has already been modified by a new transaction
- * since we took the last commit snapshot, we use the frozen copy of
- * that data for IO. If we end up using the existing buffer_head's data
- * for the write, then we *have* to lock the buffer to prevent anyone
- * else from using and possibly modifying it while the IO is in
- * progress.
- *
- * The function returns a pointer to the buffer_heads to be used for IO.
- *
- * We assume that the journal has already been locked in this function.
- *
- * Return value:
- * <0: Error
- * >=0: Finished OK
- *
- * On success:
- * Bit 0 set == escape performed on the data
- * Bit 1 set == buffer copy-out performed (kfree the data after IO)
- */
-
-int journal_write_metadata_buffer(transaction_t *transaction,
- struct journal_head *jh_in,
- struct journal_head **jh_out,
- unsigned int blocknr)
-{
- int need_copy_out = 0;
- int done_copy_out = 0;
- int do_escape = 0;
- char *mapped_data;
- struct buffer_head *new_bh;
- struct journal_head *new_jh;
- struct page *new_page;
- unsigned int new_offset;
- struct buffer_head *bh_in = jh2bh(jh_in);
- journal_t *journal = transaction->t_journal;
-
- /*
- * The buffer really shouldn't be locked: only the current committing
- * transaction is allowed to write it, so nobody else is allowed
- * to do any IO.
- *
- * akpm: except if we're journalling data, and write() output is
- * also part of a shared mapping, and another thread has
- * decided to launch a writepage() against this buffer.
- */
- J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in));
-
- new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL);
- /* keep subsequent assertions sane */
- atomic_set(&new_bh->b_count, 1);
- new_jh = journal_add_journal_head(new_bh); /* This sleeps */
-
- /*
- * If a new transaction has already done a buffer copy-out, then
- * we use that version of the data for the commit.
- */
- jbd_lock_bh_state(bh_in);
-repeat:
- if (jh_in->b_frozen_data) {
- done_copy_out = 1;
- new_page = virt_to_page(jh_in->b_frozen_data);
- new_offset = offset_in_page(jh_in->b_frozen_data);
- } else {
- new_page = jh2bh(jh_in)->b_page;
- new_offset = offset_in_page(jh2bh(jh_in)->b_data);
- }
-
- mapped_data = kmap_atomic(new_page);
- /*
- * Check for escaping
- */
- if (*((__be32 *)(mapped_data + new_offset)) ==
- cpu_to_be32(JFS_MAGIC_NUMBER)) {
- need_copy_out = 1;
- do_escape = 1;
- }
- kunmap_atomic(mapped_data);
-
- /*
- * Do we need to do a data copy?
- */
- if (need_copy_out && !done_copy_out) {
- char *tmp;
-
- jbd_unlock_bh_state(bh_in);
- tmp = jbd_alloc(bh_in->b_size, GFP_NOFS);
- jbd_lock_bh_state(bh_in);
- if (jh_in->b_frozen_data) {
- jbd_free(tmp, bh_in->b_size);
- goto repeat;
- }
-
- jh_in->b_frozen_data = tmp;
- mapped_data = kmap_atomic(new_page);
- memcpy(tmp, mapped_data + new_offset, jh2bh(jh_in)->b_size);
- kunmap_atomic(mapped_data);
-
- new_page = virt_to_page(tmp);
- new_offset = offset_in_page(tmp);
- done_copy_out = 1;
- }
-
- /*
- * Did we need to do an escaping? Now we've done all the
- * copying, we can finally do so.
- */
- if (do_escape) {
- mapped_data = kmap_atomic(new_page);
- *((unsigned int *)(mapped_data + new_offset)) = 0;
- kunmap_atomic(mapped_data);
- }
-
- set_bh_page(new_bh, new_page, new_offset);
- new_jh->b_transaction = NULL;
- new_bh->b_size = jh2bh(jh_in)->b_size;
- new_bh->b_bdev = transaction->t_journal->j_dev;
- new_bh->b_blocknr = blocknr;
- set_buffer_mapped(new_bh);
- set_buffer_dirty(new_bh);
-
- *jh_out = new_jh;
-
- /*
- * The to-be-written buffer needs to get moved to the io queue,
- * and the original buffer whose contents we are shadowing or
- * copying is moved to the transaction's shadow queue.
- */
- JBUFFER_TRACE(jh_in, "file as BJ_Shadow");
- spin_lock(&journal->j_list_lock);
- __journal_file_buffer(jh_in, transaction, BJ_Shadow);
- spin_unlock(&journal->j_list_lock);
- jbd_unlock_bh_state(bh_in);
-
- JBUFFER_TRACE(new_jh, "file as BJ_IO");
- journal_file_buffer(new_jh, transaction, BJ_IO);
-
- return do_escape | (done_copy_out << 1);
-}
-
-/*
- * Allocation code for the journal file. Manage the space left in the
- * journal, so that we can begin checkpointing when appropriate.
- */
-
-/*
- * __log_space_left: Return the number of free blocks left in the journal.
- *
- * Called with the journal already locked.
- *
- * Called under j_state_lock
- */
-
-int __log_space_left(journal_t *journal)
-{
- int left = journal->j_free;
-
- assert_spin_locked(&journal->j_state_lock);
-
- /*
- * Be pessimistic here about the number of those free blocks which
- * might be required for log descriptor control blocks.
- */
-
-#define MIN_LOG_RESERVED_BLOCKS 32 /* Allow for rounding errors */
-
- left -= MIN_LOG_RESERVED_BLOCKS;
-
- if (left <= 0)
- return 0;
- left -= (left >> 3);
- return left;
-}
-
-/*
- * Called under j_state_lock. Returns true if a transaction commit was started.
- */
-int __log_start_commit(journal_t *journal, tid_t target)
-{
- /*
- * The only transaction we can possibly wait upon is the
- * currently running transaction (if it exists). Otherwise,
- * the target tid must be an old one.
- */
- if (journal->j_commit_request != target &&
- journal->j_running_transaction &&
- journal->j_running_transaction->t_tid == target) {
- /*
- * We want a new commit: OK, mark the request and wakeup the
- * commit thread. We do _not_ do the commit ourselves.
- */
-
- journal->j_commit_request = target;
- jbd_debug(1, "JBD: requesting commit %d/%d\n",
- journal->j_commit_request,
- journal->j_commit_sequence);
- wake_up(&journal->j_wait_commit);
- return 1;
- } else if (!tid_geq(journal->j_commit_request, target))
- /* This should never happen, but if it does, preserve
- the evidence before kjournald goes into a loop and
- increments j_commit_sequence beyond all recognition. */
- WARN_ONCE(1, "jbd: bad log_start_commit: %u %u %u %u\n",
- journal->j_commit_request, journal->j_commit_sequence,
- target, journal->j_running_transaction ?
- journal->j_running_transaction->t_tid : 0);
- return 0;
-}
-
-int log_start_commit(journal_t *journal, tid_t tid)
-{
- int ret;
-
- spin_lock(&journal->j_state_lock);
- ret = __log_start_commit(journal, tid);
- spin_unlock(&journal->j_state_lock);
- return ret;
-}
-
-/*
- * Force and wait upon a commit if the calling process is not within
- * transaction. This is used for forcing out undo-protected data which contains
- * bitmaps, when the fs is running out of space.
- *
- * We can only force the running transaction if we don't have an active handle;
- * otherwise, we will deadlock.
- *
- * Returns true if a transaction was started.
- */
-int journal_force_commit_nested(journal_t *journal)
-{
- transaction_t *transaction = NULL;
- tid_t tid;
-
- spin_lock(&journal->j_state_lock);
- if (journal->j_running_transaction && !current->journal_info) {
- transaction = journal->j_running_transaction;
- __log_start_commit(journal, transaction->t_tid);
- } else if (journal->j_committing_transaction)
- transaction = journal->j_committing_transaction;
-
- if (!transaction) {
- spin_unlock(&journal->j_state_lock);
- return 0; /* Nothing to retry */
- }
-
- tid = transaction->t_tid;
- spin_unlock(&journal->j_state_lock);
- log_wait_commit(journal, tid);
- return 1;
-}
-
-/*
- * Start a commit of the current running transaction (if any). Returns true
- * if a transaction is going to be committed (or is currently already
- * committing), and fills its tid in at *ptid
- */
-int journal_start_commit(journal_t *journal, tid_t *ptid)
-{
- int ret = 0;
-
- spin_lock(&journal->j_state_lock);
- if (journal->j_running_transaction) {
- tid_t tid = journal->j_running_transaction->t_tid;
-
- __log_start_commit(journal, tid);
- /* There's a running transaction and we've just made sure
- * it's commit has been scheduled. */
- if (ptid)
- *ptid = tid;
- ret = 1;
- } else if (journal->j_committing_transaction) {
- /*
- * If commit has been started, then we have to wait for
- * completion of that transaction.
- */
- if (ptid)
- *ptid = journal->j_committing_transaction->t_tid;
- ret = 1;
- }
- spin_unlock(&journal->j_state_lock);
- return ret;
-}
-
-/*
- * Wait for a specified commit to complete.
- * The caller may not hold the journal lock.
- */
-int log_wait_commit(journal_t *journal, tid_t tid)
-{
- int err = 0;
-
-#ifdef CONFIG_JBD_DEBUG
- spin_lock(&journal->j_state_lock);
- if (!tid_geq(journal->j_commit_request, tid)) {
- printk(KERN_ERR
- "%s: error: j_commit_request=%d, tid=%d\n",
- __func__, journal->j_commit_request, tid);
- }
- spin_unlock(&journal->j_state_lock);
-#endif
- spin_lock(&journal->j_state_lock);
- /*
- * Not running or committing trans? Must be already committed. This
- * saves us from waiting for a *long* time when tid overflows.
- */
- if (!((journal->j_running_transaction &&
- journal->j_running_transaction->t_tid == tid) ||
- (journal->j_committing_transaction &&
- journal->j_committing_transaction->t_tid == tid)))
- goto out_unlock;
-
- if (!tid_geq(journal->j_commit_waited, tid))
- journal->j_commit_waited = tid;
- while (tid_gt(tid, journal->j_commit_sequence)) {
- jbd_debug(1, "JBD: want %d, j_commit_sequence=%d\n",
- tid, journal->j_commit_sequence);
- wake_up(&journal->j_wait_commit);
- spin_unlock(&journal->j_state_lock);
- wait_event(journal->j_wait_done_commit,
- !tid_gt(tid, journal->j_commit_sequence));
- spin_lock(&journal->j_state_lock);
- }
-out_unlock:
- spin_unlock(&journal->j_state_lock);
-
- if (unlikely(is_journal_aborted(journal)))
- err = -EIO;
- return err;
-}
-
-/*
- * Return 1 if a given transaction has not yet sent barrier request
- * connected with a transaction commit. If 0 is returned, transaction
- * may or may not have sent the barrier. Used to avoid sending barrier
- * twice in common cases.
- */
-int journal_trans_will_send_data_barrier(journal_t *journal, tid_t tid)
-{
- int ret = 0;
- transaction_t *commit_trans;
-
- if (!(journal->j_flags & JFS_BARRIER))
- return 0;
- spin_lock(&journal->j_state_lock);
- /* Transaction already committed? */
- if (tid_geq(journal->j_commit_sequence, tid))
- goto out;
- /*
- * Transaction is being committed and we already proceeded to
- * writing commit record?
- */
- commit_trans = journal->j_committing_transaction;
- if (commit_trans && commit_trans->t_tid == tid &&
- commit_trans->t_state >= T_COMMIT_RECORD)
- goto out;
- ret = 1;
-out:
- spin_unlock(&journal->j_state_lock);
- return ret;
-}
-EXPORT_SYMBOL(journal_trans_will_send_data_barrier);
-
-/*
- * Log buffer allocation routines:
- */
-
-int journal_next_log_block(journal_t *journal, unsigned int *retp)
-{
- unsigned int blocknr;
-
- spin_lock(&journal->j_state_lock);
- J_ASSERT(journal->j_free > 1);
-
- blocknr = journal->j_head;
- journal->j_head++;
- journal->j_free--;
- if (journal->j_head == journal->j_last)
- journal->j_head = journal->j_first;
- spin_unlock(&journal->j_state_lock);
- return journal_bmap(journal, blocknr, retp);
-}
-
-/*
- * Conversion of logical to physical block numbers for the journal
- *
- * On external journals the journal blocks are identity-mapped, so
- * this is a no-op. If needed, we can use j_blk_offset - everything is
- * ready.
- */
-int journal_bmap(journal_t *journal, unsigned int blocknr,
- unsigned int *retp)
-{
- int err = 0;
- unsigned int ret;
-
- if (journal->j_inode) {
- ret = bmap(journal->j_inode, blocknr);
- if (ret)
- *retp = ret;
- else {
- char b[BDEVNAME_SIZE];
-
- printk(KERN_ALERT "%s: journal block not found "
- "at offset %u on %s\n",
- __func__,
- blocknr,
- bdevname(journal->j_dev, b));
- err = -EIO;
- __journal_abort_soft(journal, err);
- }
- } else {
- *retp = blocknr; /* +journal->j_blk_offset */
- }
- return err;
-}
-
-/*
- * We play buffer_head aliasing tricks to write data/metadata blocks to
- * the journal without copying their contents, but for journal
- * descriptor blocks we do need to generate bona fide buffers.
- *
- * After the caller of journal_get_descriptor_buffer() has finished modifying
- * the buffer's contents they really should run flush_dcache_page(bh->b_page).
- * But we don't bother doing that, so there will be coherency problems with
- * mmaps of blockdevs which hold live JBD-controlled filesystems.
- */
-struct journal_head *journal_get_descriptor_buffer(journal_t *journal)
-{
- struct buffer_head *bh;
- unsigned int blocknr;
- int err;
-
- err = journal_next_log_block(journal, &blocknr);
-
- if (err)
- return NULL;
-
- bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
- if (!bh)
- return NULL;
- lock_buffer(bh);
- memset(bh->b_data, 0, journal->j_blocksize);
- set_buffer_uptodate(bh);
- unlock_buffer(bh);
- BUFFER_TRACE(bh, "return this buffer");
- return journal_add_journal_head(bh);
-}
-
-/*
- * Management for journal control blocks: functions to create and
- * destroy journal_t structures, and to initialise and read existing
- * journal blocks from disk. */
-
-/* First: create and setup a journal_t object in memory. We initialise
- * very few fields yet: that has to wait until we have created the
- * journal structures from from scratch, or loaded them from disk. */
-
-static journal_t * journal_init_common (void)
-{
- journal_t *journal;
- int err;
-
- journal = kzalloc(sizeof(*journal), GFP_KERNEL);
- if (!journal)
- goto fail;
-
- init_waitqueue_head(&journal->j_wait_transaction_locked);
- init_waitqueue_head(&journal->j_wait_logspace);
- init_waitqueue_head(&journal->j_wait_done_commit);
- init_waitqueue_head(&journal->j_wait_checkpoint);
- init_waitqueue_head(&journal->j_wait_commit);
- init_waitqueue_head(&journal->j_wait_updates);
- mutex_init(&journal->j_checkpoint_mutex);
- spin_lock_init(&journal->j_revoke_lock);
- spin_lock_init(&journal->j_list_lock);
- spin_lock_init(&journal->j_state_lock);
-
- journal->j_commit_interval = (HZ * JBD_DEFAULT_MAX_COMMIT_AGE);
-
- /* The journal is marked for error until we succeed with recovery! */
- journal->j_flags = JFS_ABORT;
-
- /* Set up a default-sized revoke table for the new mount. */
- err = journal_init_revoke(journal, JOURNAL_REVOKE_DEFAULT_HASH);
- if (err) {
- kfree(journal);
- goto fail;
- }
- return journal;
-fail:
- return NULL;
-}
-
-/* journal_init_dev and journal_init_inode:
- *
- * Create a journal structure assigned some fixed set of disk blocks to
- * the journal. We don't actually touch those disk blocks yet, but we
- * need to set up all of the mapping information to tell the journaling
- * system where the journal blocks are.
- *
- */
-
-/**
- * journal_t * journal_init_dev() - creates and initialises a journal structure
- * @bdev: Block device on which to create the journal
- * @fs_dev: Device which hold journalled filesystem for this journal.
- * @start: Block nr Start of journal.
- * @len: Length of the journal in blocks.
- * @blocksize: blocksize of journalling device
- *
- * Returns: a newly created journal_t *
- *
- * journal_init_dev creates a journal which maps a fixed contiguous
- * range of blocks on an arbitrary block device.
- *
- */
-journal_t * journal_init_dev(struct block_device *bdev,
- struct block_device *fs_dev,
- int start, int len, int blocksize)
-{
- journal_t *journal = journal_init_common();
- struct buffer_head *bh;
- int n;
-
- if (!journal)
- return NULL;
-
- /* journal descriptor can store up to n blocks -bzzz */
- journal->j_blocksize = blocksize;
- n = journal->j_blocksize / sizeof(journal_block_tag_t);
- journal->j_wbufsize = n;
- journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
- if (!journal->j_wbuf) {
- printk(KERN_ERR "%s: Can't allocate bhs for commit thread\n",
- __func__);
- goto out_err;
- }
- journal->j_dev = bdev;
- journal->j_fs_dev = fs_dev;
- journal->j_blk_offset = start;
- journal->j_maxlen = len;
-
- bh = __getblk(journal->j_dev, start, journal->j_blocksize);
- if (!bh) {
- printk(KERN_ERR
- "%s: Cannot get buffer for journal superblock\n",
- __func__);
- goto out_err;
- }
- journal->j_sb_buffer = bh;
- journal->j_superblock = (journal_superblock_t *)bh->b_data;
-
- return journal;
-out_err:
- kfree(journal->j_wbuf);
- kfree(journal);
- return NULL;
-}
-
-/**
- * journal_t * journal_init_inode () - creates a journal which maps to a inode.
- * @inode: An inode to create the journal in
- *
- * journal_init_inode creates a journal which maps an on-disk inode as
- * the journal. The inode must exist already, must support bmap() and
- * must have all data blocks preallocated.
- */
-journal_t * journal_init_inode (struct inode *inode)
-{
- struct buffer_head *bh;
- journal_t *journal = journal_init_common();
- int err;
- int n;
- unsigned int blocknr;
-
- if (!journal)
- return NULL;
-
- journal->j_dev = journal->j_fs_dev = inode->i_sb->s_bdev;
- journal->j_inode = inode;
- jbd_debug(1,
- "journal %p: inode %s/%ld, size %Ld, bits %d, blksize %ld\n",
- journal, inode->i_sb->s_id, inode->i_ino,
- (long long) inode->i_size,
- inode->i_sb->s_blocksize_bits, inode->i_sb->s_blocksize);
-
- journal->j_maxlen = inode->i_size >> inode->i_sb->s_blocksize_bits;
- journal->j_blocksize = inode->i_sb->s_blocksize;
-
- /* journal descriptor can store up to n blocks -bzzz */
- n = journal->j_blocksize / sizeof(journal_block_tag_t);
- journal->j_wbufsize = n;
- journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
- if (!journal->j_wbuf) {
- printk(KERN_ERR "%s: Can't allocate bhs for commit thread\n",
- __func__);
- goto out_err;
- }
-
- err = journal_bmap(journal, 0, &blocknr);
- /* If that failed, give up */
- if (err) {
- printk(KERN_ERR "%s: Cannot locate journal superblock\n",
- __func__);
- goto out_err;
- }
-
- bh = getblk_unmovable(journal->j_dev, blocknr, journal->j_blocksize);
- if (!bh) {
- printk(KERN_ERR
- "%s: Cannot get buffer for journal superblock\n",
- __func__);
- goto out_err;
- }
- journal->j_sb_buffer = bh;
- journal->j_superblock = (journal_superblock_t *)bh->b_data;
-
- return journal;
-out_err:
- kfree(journal->j_wbuf);
- kfree(journal);
- return NULL;
-}
-
-/*
- * If the journal init or create aborts, we need to mark the journal
- * superblock as being NULL to prevent the journal destroy from writing
- * back a bogus superblock.
- */
-static void journal_fail_superblock (journal_t *journal)
-{
- struct buffer_head *bh = journal->j_sb_buffer;
- brelse(bh);
- journal->j_sb_buffer = NULL;
-}
-
-/*
- * Given a journal_t structure, initialise the various fields for
- * startup of a new journaling session. We use this both when creating
- * a journal, and after recovering an old journal to reset it for
- * subsequent use.
- */
-
-static int journal_reset(journal_t *journal)
-{
- journal_superblock_t *sb = journal->j_superblock;
- unsigned int first, last;
-
- first = be32_to_cpu(sb->s_first);
- last = be32_to_cpu(sb->s_maxlen);
- if (first + JFS_MIN_JOURNAL_BLOCKS > last + 1) {
- printk(KERN_ERR "JBD: Journal too short (blocks %u-%u).\n",
- first, last);
- journal_fail_superblock(journal);
- return -EINVAL;
- }
-
- journal->j_first = first;
- journal->j_last = last;
-
- journal->j_head = first;
- journal->j_tail = first;
- journal->j_free = last - first;
-
- journal->j_tail_sequence = journal->j_transaction_sequence;
- journal->j_commit_sequence = journal->j_transaction_sequence - 1;
- journal->j_commit_request = journal->j_commit_sequence;
-
- journal->j_max_transaction_buffers = journal->j_maxlen / 4;
-
- /*
- * As a special case, if the on-disk copy is already marked as needing
- * no recovery (s_start == 0), then we can safely defer the superblock
- * update until the next commit by setting JFS_FLUSHED. This avoids
- * attempting a write to a potential-readonly device.
- */
- if (sb->s_start == 0) {
- jbd_debug(1,"JBD: Skipping superblock update on recovered sb "
- "(start %u, seq %d, errno %d)\n",
- journal->j_tail, journal->j_tail_sequence,
- journal->j_errno);
- journal->j_flags |= JFS_FLUSHED;
- } else {
- /* Lock here to make assertions happy... */
- mutex_lock(&journal->j_checkpoint_mutex);
- /*
- * Update log tail information. We use WRITE_FUA since new
- * transaction will start reusing journal space and so we
- * must make sure information about current log tail is on
- * disk before that.
- */
- journal_update_sb_log_tail(journal,
- journal->j_tail_sequence,
- journal->j_tail,
- WRITE_FUA);
- mutex_unlock(&journal->j_checkpoint_mutex);
- }
- return journal_start_thread(journal);
-}
-
-/**
- * int journal_create() - Initialise the new journal file
- * @journal: Journal to create. This structure must have been initialised
- *
- * Given a journal_t structure which tells us which disk blocks we can
- * use, create a new journal superblock and initialise all of the
- * journal fields from scratch.
- **/
-int journal_create(journal_t *journal)
-{
- unsigned int blocknr;
- struct buffer_head *bh;
- journal_superblock_t *sb;
- int i, err;
-
- if (journal->j_maxlen < JFS_MIN_JOURNAL_BLOCKS) {
- printk (KERN_ERR "Journal length (%d blocks) too short.\n",
- journal->j_maxlen);
- journal_fail_superblock(journal);
- return -EINVAL;
- }
-
- if (journal->j_inode == NULL) {
- /*
- * We don't know what block to start at!
- */
- printk(KERN_EMERG
- "%s: creation of journal on external device!\n",
- __func__);
- BUG();
- }
-
- /* Zero out the entire journal on disk. We cannot afford to
- have any blocks on disk beginning with JFS_MAGIC_NUMBER. */
- jbd_debug(1, "JBD: Zeroing out journal blocks...\n");
- for (i = 0; i < journal->j_maxlen; i++) {
- err = journal_bmap(journal, i, &blocknr);
- if (err)
- return err;
- bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
- if (unlikely(!bh))
- return -ENOMEM;
- lock_buffer(bh);
- memset (bh->b_data, 0, journal->j_blocksize);
- BUFFER_TRACE(bh, "marking dirty");
- mark_buffer_dirty(bh);
- BUFFER_TRACE(bh, "marking uptodate");
- set_buffer_uptodate(bh);
- unlock_buffer(bh);
- __brelse(bh);
- }
-
- sync_blockdev(journal->j_dev);
- jbd_debug(1, "JBD: journal cleared.\n");
-
- /* OK, fill in the initial static fields in the new superblock */
- sb = journal->j_superblock;
-
- sb->s_header.h_magic = cpu_to_be32(JFS_MAGIC_NUMBER);
- sb->s_header.h_blocktype = cpu_to_be32(JFS_SUPERBLOCK_V2);
-
- sb->s_blocksize = cpu_to_be32(journal->j_blocksize);
- sb->s_maxlen = cpu_to_be32(journal->j_maxlen);
- sb->s_first = cpu_to_be32(1);
-
- journal->j_transaction_sequence = 1;
-
- journal->j_flags &= ~JFS_ABORT;
- journal->j_format_version = 2;
-
- return journal_reset(journal);
-}
-
-static void journal_write_superblock(journal_t *journal, int write_op)
-{
- struct buffer_head *bh = journal->j_sb_buffer;
- int ret;
-
- trace_journal_write_superblock(journal, write_op);
- if (!(journal->j_flags & JFS_BARRIER))
- write_op &= ~(REQ_FUA | REQ_FLUSH);
- lock_buffer(bh);
- if (buffer_write_io_error(bh)) {
- char b[BDEVNAME_SIZE];
- /*
- * Oh, dear. A previous attempt to write the journal
- * superblock failed. This could happen because the
- * USB device was yanked out. Or it could happen to
- * be a transient write error and maybe the block will
- * be remapped. Nothing we can do but to retry the
- * write and hope for the best.
- */
- printk(KERN_ERR "JBD: previous I/O error detected "
- "for journal superblock update for %s.\n",
- journal_dev_name(journal, b));
- clear_buffer_write_io_error(bh);
- set_buffer_uptodate(bh);
- }
-
- get_bh(bh);
- bh->b_end_io = end_buffer_write_sync;
- ret = submit_bh(write_op, bh);
- wait_on_buffer(bh);
- if (buffer_write_io_error(bh)) {
- clear_buffer_write_io_error(bh);
- set_buffer_uptodate(bh);
- ret = -EIO;
- }
- if (ret) {
- char b[BDEVNAME_SIZE];
- printk(KERN_ERR "JBD: Error %d detected "
- "when updating journal superblock for %s.\n",
- ret, journal_dev_name(journal, b));
- }
-}
-
-/**
- * journal_update_sb_log_tail() - Update log tail in journal sb on disk.
- * @journal: The journal to update.
- * @tail_tid: TID of the new transaction at the tail of the log
- * @tail_block: The first block of the transaction at the tail of the log
- * @write_op: With which operation should we write the journal sb
- *
- * Update a journal's superblock information about log tail and write it to
- * disk, waiting for the IO to complete.
- */
-void journal_update_sb_log_tail(journal_t *journal, tid_t tail_tid,
- unsigned int tail_block, int write_op)
-{
- journal_superblock_t *sb = journal->j_superblock;
-
- BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
- jbd_debug(1,"JBD: updating superblock (start %u, seq %u)\n",
- tail_block, tail_tid);
-
- sb->s_sequence = cpu_to_be32(tail_tid);
- sb->s_start = cpu_to_be32(tail_block);
-
- journal_write_superblock(journal, write_op);
-
- /* Log is no longer empty */
- spin_lock(&journal->j_state_lock);
- WARN_ON(!sb->s_sequence);
- journal->j_flags &= ~JFS_FLUSHED;
- spin_unlock(&journal->j_state_lock);
-}
-
-/**
- * mark_journal_empty() - Mark on disk journal as empty.
- * @journal: The journal to update.
- *
- * Update a journal's dynamic superblock fields to show that journal is empty.
- * Write updated superblock to disk waiting for IO to complete.
- */
-static void mark_journal_empty(journal_t *journal)
-{
- journal_superblock_t *sb = journal->j_superblock;
-
- BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
- spin_lock(&journal->j_state_lock);
- /* Is it already empty? */
- if (sb->s_start == 0) {
- spin_unlock(&journal->j_state_lock);
- return;
- }
- jbd_debug(1, "JBD: Marking journal as empty (seq %d)\n",
- journal->j_tail_sequence);
-
- sb->s_sequence = cpu_to_be32(journal->j_tail_sequence);
- sb->s_start = cpu_to_be32(0);
- spin_unlock(&journal->j_state_lock);
-
- journal_write_superblock(journal, WRITE_FUA);
-
- spin_lock(&journal->j_state_lock);
- /* Log is empty */
- journal->j_flags |= JFS_FLUSHED;
- spin_unlock(&journal->j_state_lock);
-}
-
-/**
- * journal_update_sb_errno() - Update error in the journal.
- * @journal: The journal to update.
- *
- * Update a journal's errno. Write updated superblock to disk waiting for IO
- * to complete.
- */
-static void journal_update_sb_errno(journal_t *journal)
-{
- journal_superblock_t *sb = journal->j_superblock;
-
- spin_lock(&journal->j_state_lock);
- jbd_debug(1, "JBD: updating superblock error (errno %d)\n",
- journal->j_errno);
- sb->s_errno = cpu_to_be32(journal->j_errno);
- spin_unlock(&journal->j_state_lock);
-
- journal_write_superblock(journal, WRITE_SYNC);
-}
-
-/*
- * Read the superblock for a given journal, performing initial
- * validation of the format.
- */
-
-static int journal_get_superblock(journal_t *journal)
-{
- struct buffer_head *bh;
- journal_superblock_t *sb;
- int err = -EIO;
-
- bh = journal->j_sb_buffer;
-
- J_ASSERT(bh != NULL);
- if (!buffer_uptodate(bh)) {
- ll_rw_block(READ, 1, &bh);
- wait_on_buffer(bh);
- if (!buffer_uptodate(bh)) {
- printk (KERN_ERR
- "JBD: IO error reading journal superblock\n");
- goto out;
- }
- }
-
- sb = journal->j_superblock;
-
- err = -EINVAL;
-
- if (sb->s_header.h_magic != cpu_to_be32(JFS_MAGIC_NUMBER) ||
- sb->s_blocksize != cpu_to_be32(journal->j_blocksize)) {
- printk(KERN_WARNING "JBD: no valid journal superblock found\n");
- goto out;
- }
-
- switch(be32_to_cpu(sb->s_header.h_blocktype)) {
- case JFS_SUPERBLOCK_V1:
- journal->j_format_version = 1;
- break;
- case JFS_SUPERBLOCK_V2:
- journal->j_format_version = 2;
- break;
- default:
- printk(KERN_WARNING "JBD: unrecognised superblock format ID\n");
- goto out;
- }
-
- if (be32_to_cpu(sb->s_maxlen) < journal->j_maxlen)
- journal->j_maxlen = be32_to_cpu(sb->s_maxlen);
- else if (be32_to_cpu(sb->s_maxlen) > journal->j_maxlen) {
- printk (KERN_WARNING "JBD: journal file too short\n");
- goto out;
- }
-
- if (be32_to_cpu(sb->s_first) == 0 ||
- be32_to_cpu(sb->s_first) >= journal->j_maxlen) {
- printk(KERN_WARNING
- "JBD: Invalid start block of journal: %u\n",
- be32_to_cpu(sb->s_first));
- goto out;
- }
-
- return 0;
-
-out:
- journal_fail_superblock(journal);
- return err;
-}
-
-/*
- * Load the on-disk journal superblock and read the key fields into the
- * journal_t.
- */
-
-static int load_superblock(journal_t *journal)
-{
- int err;
- journal_superblock_t *sb;
-
- err = journal_get_superblock(journal);
- if (err)
- return err;
-
- sb = journal->j_superblock;
-
- journal->j_tail_sequence = be32_to_cpu(sb->s_sequence);
- journal->j_tail = be32_to_cpu(sb->s_start);
- journal->j_first = be32_to_cpu(sb->s_first);
- journal->j_last = be32_to_cpu(sb->s_maxlen);
- journal->j_errno = be32_to_cpu(sb->s_errno);
-
- return 0;
-}
-
-
-/**
- * int journal_load() - Read journal from disk.
- * @journal: Journal to act on.
- *
- * Given a journal_t structure which tells us which disk blocks contain
- * a journal, read the journal from disk to initialise the in-memory
- * structures.
- */
-int journal_load(journal_t *journal)
-{
- int err;
- journal_superblock_t *sb;
-
- err = load_superblock(journal);
- if (err)
- return err;
-
- sb = journal->j_superblock;
- /* If this is a V2 superblock, then we have to check the
- * features flags on it. */
-
- if (journal->j_format_version >= 2) {
- if ((sb->s_feature_ro_compat &
- ~cpu_to_be32(JFS_KNOWN_ROCOMPAT_FEATURES)) ||
- (sb->s_feature_incompat &
- ~cpu_to_be32(JFS_KNOWN_INCOMPAT_FEATURES))) {
- printk (KERN_WARNING
- "JBD: Unrecognised features on journal\n");
- return -EINVAL;
- }
- }
-
- /* Let the recovery code check whether it needs to recover any
- * data from the journal. */
- if (journal_recover(journal))
- goto recovery_error;
-
- /* OK, we've finished with the dynamic journal bits:
- * reinitialise the dynamic contents of the superblock in memory
- * and reset them on disk. */
- if (journal_reset(journal))
- goto recovery_error;
-
- journal->j_flags &= ~JFS_ABORT;
- journal->j_flags |= JFS_LOADED;
- return 0;
-
-recovery_error:
- printk (KERN_WARNING "JBD: recovery failed\n");
- return -EIO;
-}
-
-/**
- * void journal_destroy() - Release a journal_t structure.
- * @journal: Journal to act on.
- *
- * Release a journal_t structure once it is no longer in use by the
- * journaled object.
- * Return <0 if we couldn't clean up the journal.
- */
-int journal_destroy(journal_t *journal)
-{
- int err = 0;
-
-
- /* Wait for the commit thread to wake up and die. */
- journal_kill_thread(journal);
-
- /* Force a final log commit */
- if (journal->j_running_transaction)
- journal_commit_transaction(journal);
-
- /* Force any old transactions to disk */
-
- /* We cannot race with anybody but must keep assertions happy */
- mutex_lock(&journal->j_checkpoint_mutex);
- /* Totally anal locking here... */
- spin_lock(&journal->j_list_lock);
- while (journal->j_checkpoint_transactions != NULL) {
- spin_unlock(&journal->j_list_lock);
- log_do_checkpoint(journal);
- spin_lock(&journal->j_list_lock);
- }
-
- J_ASSERT(journal->j_running_transaction == NULL);
- J_ASSERT(journal->j_committing_transaction == NULL);
- J_ASSERT(journal->j_checkpoint_transactions == NULL);
- spin_unlock(&journal->j_list_lock);
-
- if (journal->j_sb_buffer) {
- if (!is_journal_aborted(journal)) {
- journal->j_tail_sequence =
- ++journal->j_transaction_sequence;
- mark_journal_empty(journal);
- } else
- err = -EIO;
- brelse(journal->j_sb_buffer);
- }
- mutex_unlock(&journal->j_checkpoint_mutex);
-
- iput(journal->j_inode);
- if (journal->j_revoke)
- journal_destroy_revoke(journal);
- kfree(journal->j_wbuf);
- kfree(journal);
-
- return err;
-}
-
-
-/**
- *int journal_check_used_features () - Check if features specified are used.
- * @journal: Journal to check.
- * @compat: bitmask of compatible features
- * @ro: bitmask of features that force read-only mount
- * @incompat: bitmask of incompatible features
- *
- * Check whether the journal uses all of a given set of
- * features. Return true (non-zero) if it does.
- **/
-
-int journal_check_used_features (journal_t *journal, unsigned long compat,
- unsigned long ro, unsigned long incompat)
-{
- journal_superblock_t *sb;
-
- if (!compat && !ro && !incompat)
- return 1;
- if (journal->j_format_version == 1)
- return 0;
-
- sb = journal->j_superblock;
-
- if (((be32_to_cpu(sb->s_feature_compat) & compat) == compat) &&
- ((be32_to_cpu(sb->s_feature_ro_compat) & ro) == ro) &&
- ((be32_to_cpu(sb->s_feature_incompat) & incompat) == incompat))
- return 1;
-
- return 0;
-}
-
-/**
- * int journal_check_available_features() - Check feature set in journalling layer
- * @journal: Journal to check.
- * @compat: bitmask of compatible features
- * @ro: bitmask of features that force read-only mount
- * @incompat: bitmask of incompatible features
- *
- * Check whether the journaling code supports the use of
- * all of a given set of features on this journal. Return true
- * (non-zero) if it can. */
-
-int journal_check_available_features (journal_t *journal, unsigned long compat,
- unsigned long ro, unsigned long incompat)
-{
- if (!compat && !ro && !incompat)
- return 1;
-
- /* We can support any known requested features iff the
- * superblock is in version 2. Otherwise we fail to support any
- * extended sb features. */
-
- if (journal->j_format_version != 2)
- return 0;
-
- if ((compat & JFS_KNOWN_COMPAT_FEATURES) == compat &&
- (ro & JFS_KNOWN_ROCOMPAT_FEATURES) == ro &&
- (incompat & JFS_KNOWN_INCOMPAT_FEATURES) == incompat)
- return 1;
-
- return 0;
-}
-
-/**
- * int journal_set_features () - Mark a given journal feature in the superblock
- * @journal: Journal to act on.
- * @compat: bitmask of compatible features
- * @ro: bitmask of features that force read-only mount
- * @incompat: bitmask of incompatible features
- *
- * Mark a given journal feature as present on the
- * superblock. Returns true if the requested features could be set.
- *
- */
-
-int journal_set_features (journal_t *journal, unsigned long compat,
- unsigned long ro, unsigned long incompat)
-{
- journal_superblock_t *sb;
-
- if (journal_check_used_features(journal, compat, ro, incompat))
- return 1;
-
- if (!journal_check_available_features(journal, compat, ro, incompat))
- return 0;
-
- jbd_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n",
- compat, ro, incompat);
-
- sb = journal->j_superblock;
-
- sb->s_feature_compat |= cpu_to_be32(compat);
- sb->s_feature_ro_compat |= cpu_to_be32(ro);
- sb->s_feature_incompat |= cpu_to_be32(incompat);
-
- return 1;
-}
-
-
-/**
- * int journal_update_format () - Update on-disk journal structure.
- * @journal: Journal to act on.
- *
- * Given an initialised but unloaded journal struct, poke about in the
- * on-disk structure to update it to the most recent supported version.
- */
-int journal_update_format (journal_t *journal)
-{
- journal_superblock_t *sb;
- int err;
-
- err = journal_get_superblock(journal);
- if (err)
- return err;
-
- sb = journal->j_superblock;
-
- switch (be32_to_cpu(sb->s_header.h_blocktype)) {
- case JFS_SUPERBLOCK_V2:
- return 0;
- case JFS_SUPERBLOCK_V1:
- return journal_convert_superblock_v1(journal, sb);
- default:
- break;
- }
- return -EINVAL;
-}
-
-static int journal_convert_superblock_v1(journal_t *journal,
- journal_superblock_t *sb)
-{
- int offset, blocksize;
- struct buffer_head *bh;
-
- printk(KERN_WARNING
- "JBD: Converting superblock from version 1 to 2.\n");
-
- /* Pre-initialise new fields to zero */
- offset = ((char *) &(sb->s_feature_compat)) - ((char *) sb);
- blocksize = be32_to_cpu(sb->s_blocksize);
- memset(&sb->s_feature_compat, 0, blocksize-offset);
-
- sb->s_nr_users = cpu_to_be32(1);
- sb->s_header.h_blocktype = cpu_to_be32(JFS_SUPERBLOCK_V2);
- journal->j_format_version = 2;
-
- bh = journal->j_sb_buffer;
- BUFFER_TRACE(bh, "marking dirty");
- mark_buffer_dirty(bh);
- sync_dirty_buffer(bh);
- return 0;
-}
-
-
-/**
- * int journal_flush () - Flush journal
- * @journal: Journal to act on.
- *
- * Flush all data for a given journal to disk and empty the journal.
- * Filesystems can use this when remounting readonly to ensure that
- * recovery does not need to happen on remount.
- */
-
-int journal_flush(journal_t *journal)
-{
- int err = 0;
- transaction_t *transaction = NULL;
-
- spin_lock(&journal->j_state_lock);
-
- /* Force everything buffered to the log... */
- if (journal->j_running_transaction) {
- transaction = journal->j_running_transaction;
- __log_start_commit(journal, transaction->t_tid);
- } else if (journal->j_committing_transaction)
- transaction = journal->j_committing_transaction;
-
- /* Wait for the log commit to complete... */
- if (transaction) {
- tid_t tid = transaction->t_tid;
-
- spin_unlock(&journal->j_state_lock);
- log_wait_commit(journal, tid);
- } else {
- spin_unlock(&journal->j_state_lock);
- }
-
- /* ...and flush everything in the log out to disk. */
- spin_lock(&journal->j_list_lock);
- while (!err && journal->j_checkpoint_transactions != NULL) {
- spin_unlock(&journal->j_list_lock);
- mutex_lock(&journal->j_checkpoint_mutex);
- err = log_do_checkpoint(journal);
- mutex_unlock(&journal->j_checkpoint_mutex);
- spin_lock(&journal->j_list_lock);
- }
- spin_unlock(&journal->j_list_lock);
-
- if (is_journal_aborted(journal))
- return -EIO;
-
- mutex_lock(&journal->j_checkpoint_mutex);
- cleanup_journal_tail(journal);
-
- /* Finally, mark the journal as really needing no recovery.
- * This sets s_start==0 in the underlying superblock, which is
- * the magic code for a fully-recovered superblock. Any future
- * commits of data to the journal will restore the current
- * s_start value. */
- mark_journal_empty(journal);
- mutex_unlock(&journal->j_checkpoint_mutex);
- spin_lock(&journal->j_state_lock);
- J_ASSERT(!journal->j_running_transaction);
- J_ASSERT(!journal->j_committing_transaction);
- J_ASSERT(!journal->j_checkpoint_transactions);
- J_ASSERT(journal->j_head == journal->j_tail);
- J_ASSERT(journal->j_tail_sequence == journal->j_transaction_sequence);
- spin_unlock(&journal->j_state_lock);
- return 0;
-}
-
-/**
- * int journal_wipe() - Wipe journal contents
- * @journal: Journal to act on.
- * @write: flag (see below)
- *
- * Wipe out all of the contents of a journal, safely. This will produce
- * a warning if the journal contains any valid recovery information.
- * Must be called between journal_init_*() and journal_load().
- *
- * If 'write' is non-zero, then we wipe out the journal on disk; otherwise
- * we merely suppress recovery.
- */
-
-int journal_wipe(journal_t *journal, int write)
-{
- int err = 0;
-
- J_ASSERT (!(journal->j_flags & JFS_LOADED));
-
- err = load_superblock(journal);
- if (err)
- return err;
-
- if (!journal->j_tail)
- goto no_recovery;
-
- printk (KERN_WARNING "JBD: %s recovery information on journal\n",
- write ? "Clearing" : "Ignoring");
-
- err = journal_skip_recovery(journal);
- if (write) {
- /* Lock to make assertions happy... */
- mutex_lock(&journal->j_checkpoint_mutex);
- mark_journal_empty(journal);
- mutex_unlock(&journal->j_checkpoint_mutex);
- }
-
- no_recovery:
- return err;
-}
-
-/*
- * journal_dev_name: format a character string to describe on what
- * device this journal is present.
- */
-
-static const char *journal_dev_name(journal_t *journal, char *buffer)
-{
- struct block_device *bdev;
-
- if (journal->j_inode)
- bdev = journal->j_inode->i_sb->s_bdev;
- else
- bdev = journal->j_dev;
-
- return bdevname(bdev, buffer);
-}
-
-/*
- * Journal abort has very specific semantics, which we describe
- * for journal abort.
- *
- * Two internal function, which provide abort to te jbd layer
- * itself are here.
- */
-
-/*
- * Quick version for internal journal use (doesn't lock the journal).
- * Aborts hard --- we mark the abort as occurred, but do _nothing_ else,
- * and don't attempt to make any other journal updates.
- */
-static void __journal_abort_hard(journal_t *journal)
-{
- transaction_t *transaction;
- char b[BDEVNAME_SIZE];
-
- if (journal->j_flags & JFS_ABORT)
- return;
-
- printk(KERN_ERR "Aborting journal on device %s.\n",
- journal_dev_name(journal, b));
-
- spin_lock(&journal->j_state_lock);
- journal->j_flags |= JFS_ABORT;
- transaction = journal->j_running_transaction;
- if (transaction)
- __log_start_commit(journal, transaction->t_tid);
- spin_unlock(&journal->j_state_lock);
-}
-
-/* Soft abort: record the abort error status in the journal superblock,
- * but don't do any other IO. */
-static void __journal_abort_soft (journal_t *journal, int errno)
-{
- if (journal->j_flags & JFS_ABORT)
- return;
-
- if (!journal->j_errno)
- journal->j_errno = errno;
-
- __journal_abort_hard(journal);
-
- if (errno)
- journal_update_sb_errno(journal);
-}
-
-/**
- * void journal_abort () - Shutdown the journal immediately.
- * @journal: the journal to shutdown.
- * @errno: an error number to record in the journal indicating
- * the reason for the shutdown.
- *
- * Perform a complete, immediate shutdown of the ENTIRE
- * journal (not of a single transaction). This operation cannot be
- * undone without closing and reopening the journal.
- *
- * The journal_abort function is intended to support higher level error
- * recovery mechanisms such as the ext2/ext3 remount-readonly error
- * mode.
- *
- * Journal abort has very specific semantics. Any existing dirty,
- * unjournaled buffers in the main filesystem will still be written to
- * disk by bdflush, but the journaling mechanism will be suspended
- * immediately and no further transaction commits will be honoured.
- *
- * Any dirty, journaled buffers will be written back to disk without
- * hitting the journal. Atomicity cannot be guaranteed on an aborted
- * filesystem, but we _do_ attempt to leave as much data as possible
- * behind for fsck to use for cleanup.
- *
- * Any attempt to get a new transaction handle on a journal which is in
- * ABORT state will just result in an -EROFS error return. A
- * journal_stop on an existing handle will return -EIO if we have
- * entered abort state during the update.
- *
- * Recursive transactions are not disturbed by journal abort until the
- * final journal_stop, which will receive the -EIO error.
- *
- * Finally, the journal_abort call allows the caller to supply an errno
- * which will be recorded (if possible) in the journal superblock. This
- * allows a client to record failure conditions in the middle of a
- * transaction without having to complete the transaction to record the
- * failure to disk. ext3_error, for example, now uses this
- * functionality.
- *
- * Errors which originate from within the journaling layer will NOT
- * supply an errno; a null errno implies that absolutely no further
- * writes are done to the journal (unless there are any already in
- * progress).
- *
- */
-
-void journal_abort(journal_t *journal, int errno)
-{
- __journal_abort_soft(journal, errno);
-}
-
-/**
- * int journal_errno () - returns the journal's error state.
- * @journal: journal to examine.
- *
- * This is the errno numbet set with journal_abort(), the last
- * time the journal was mounted - if the journal was stopped
- * without calling abort this will be 0.
- *
- * If the journal has been aborted on this mount time -EROFS will
- * be returned.
- */
-int journal_errno(journal_t *journal)
-{
- int err;
-
- spin_lock(&journal->j_state_lock);
- if (journal->j_flags & JFS_ABORT)
- err = -EROFS;
- else
- err = journal->j_errno;
- spin_unlock(&journal->j_state_lock);
- return err;
-}
-
-/**
- * int journal_clear_err () - clears the journal's error state
- * @journal: journal to act on.
- *
- * An error must be cleared or Acked to take a FS out of readonly
- * mode.
- */
-int journal_clear_err(journal_t *journal)
-{
- int err = 0;
-
- spin_lock(&journal->j_state_lock);
- if (journal->j_flags & JFS_ABORT)
- err = -EROFS;
- else
- journal->j_errno = 0;
- spin_unlock(&journal->j_state_lock);
- return err;
-}
-
-/**
- * void journal_ack_err() - Ack journal err.
- * @journal: journal to act on.
- *
- * An error must be cleared or Acked to take a FS out of readonly
- * mode.
- */
-void journal_ack_err(journal_t *journal)
-{
- spin_lock(&journal->j_state_lock);
- if (journal->j_errno)
- journal->j_flags |= JFS_ACK_ERR;
- spin_unlock(&journal->j_state_lock);
-}
-
-int journal_blocks_per_page(struct inode *inode)
-{
- return 1 << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
-}
-
-/*
- * Journal_head storage management
- */
-static struct kmem_cache *journal_head_cache;
-#ifdef CONFIG_JBD_DEBUG
-static atomic_t nr_journal_heads = ATOMIC_INIT(0);
-#endif
-
-static int journal_init_journal_head_cache(void)
-{
- int retval;
-
- J_ASSERT(journal_head_cache == NULL);
- journal_head_cache = kmem_cache_create("journal_head",
- sizeof(struct journal_head),
- 0, /* offset */
- SLAB_TEMPORARY, /* flags */
- NULL); /* ctor */
- retval = 0;
- if (!journal_head_cache) {
- retval = -ENOMEM;
- printk(KERN_EMERG "JBD: no memory for journal_head cache\n");
- }
- return retval;
-}
-
-static void journal_destroy_journal_head_cache(void)
-{
- if (journal_head_cache) {
- kmem_cache_destroy(journal_head_cache);
- journal_head_cache = NULL;
- }
-}
-
-/*
- * journal_head splicing and dicing
- */
-static struct journal_head *journal_alloc_journal_head(void)
-{
- struct journal_head *ret;
-
-#ifdef CONFIG_JBD_DEBUG
- atomic_inc(&nr_journal_heads);
-#endif
- ret = kmem_cache_zalloc(journal_head_cache, GFP_NOFS);
- if (ret == NULL) {
- jbd_debug(1, "out of memory for journal_head\n");
- printk_ratelimited(KERN_NOTICE "ENOMEM in %s, retrying.\n",
- __func__);
-
- while (ret == NULL) {
- yield();
- ret = kmem_cache_zalloc(journal_head_cache, GFP_NOFS);
- }
- }
- return ret;
-}
-
-static void journal_free_journal_head(struct journal_head *jh)
-{
-#ifdef CONFIG_JBD_DEBUG
- atomic_dec(&nr_journal_heads);
- memset(jh, JBD_POISON_FREE, sizeof(*jh));
-#endif
- kmem_cache_free(journal_head_cache, jh);
-}
-
-/*
- * A journal_head is attached to a buffer_head whenever JBD has an
- * interest in the buffer.
- *
- * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit
- * is set. This bit is tested in core kernel code where we need to take
- * JBD-specific actions. Testing the zeroness of ->b_private is not reliable
- * there.
- *
- * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one.
- *
- * When a buffer has its BH_JBD bit set it is immune from being released by
- * core kernel code, mainly via ->b_count.
- *
- * A journal_head is detached from its buffer_head when the journal_head's
- * b_jcount reaches zero. Running transaction (b_transaction) and checkpoint
- * transaction (b_cp_transaction) hold their references to b_jcount.
- *
- * Various places in the kernel want to attach a journal_head to a buffer_head
- * _before_ attaching the journal_head to a transaction. To protect the
- * journal_head in this situation, journal_add_journal_head elevates the
- * journal_head's b_jcount refcount by one. The caller must call
- * journal_put_journal_head() to undo this.
- *
- * So the typical usage would be:
- *
- * (Attach a journal_head if needed. Increments b_jcount)
- * struct journal_head *jh = journal_add_journal_head(bh);
- * ...
- * (Get another reference for transaction)
- * journal_grab_journal_head(bh);
- * jh->b_transaction = xxx;
- * (Put original reference)
- * journal_put_journal_head(jh);
- */
-
-/*
- * Give a buffer_head a journal_head.
- *
- * May sleep.
- */
-struct journal_head *journal_add_journal_head(struct buffer_head *bh)
-{
- struct journal_head *jh;
- struct journal_head *new_jh = NULL;
-
-repeat:
- if (!buffer_jbd(bh))
- new_jh = journal_alloc_journal_head();
-
- jbd_lock_bh_journal_head(bh);
- if (buffer_jbd(bh)) {
- jh = bh2jh(bh);
- } else {
- J_ASSERT_BH(bh,
- (atomic_read(&bh->b_count) > 0) ||
- (bh->b_page && bh->b_page->mapping));
-
- if (!new_jh) {
- jbd_unlock_bh_journal_head(bh);
- goto repeat;
- }
-
- jh = new_jh;
- new_jh = NULL; /* We consumed it */
- set_buffer_jbd(bh);
- bh->b_private = jh;
- jh->b_bh = bh;
- get_bh(bh);
- BUFFER_TRACE(bh, "added journal_head");
- }
- jh->b_jcount++;
- jbd_unlock_bh_journal_head(bh);
- if (new_jh)
- journal_free_journal_head(new_jh);
- return bh->b_private;
-}
-
-/*
- * Grab a ref against this buffer_head's journal_head. If it ended up not
- * having a journal_head, return NULL
- */
-struct journal_head *journal_grab_journal_head(struct buffer_head *bh)
-{
- struct journal_head *jh = NULL;
-
- jbd_lock_bh_journal_head(bh);
- if (buffer_jbd(bh)) {
- jh = bh2jh(bh);
- jh->b_jcount++;
- }
- jbd_unlock_bh_journal_head(bh);
- return jh;
-}
-
-static void __journal_remove_journal_head(struct buffer_head *bh)
-{
- struct journal_head *jh = bh2jh(bh);
-
- J_ASSERT_JH(jh, jh->b_jcount >= 0);
- J_ASSERT_JH(jh, jh->b_transaction == NULL);
- J_ASSERT_JH(jh, jh->b_next_transaction == NULL);
- J_ASSERT_JH(jh, jh->b_cp_transaction == NULL);
- J_ASSERT_JH(jh, jh->b_jlist == BJ_None);
- J_ASSERT_BH(bh, buffer_jbd(bh));
- J_ASSERT_BH(bh, jh2bh(jh) == bh);
- BUFFER_TRACE(bh, "remove journal_head");
- if (jh->b_frozen_data) {
- printk(KERN_WARNING "%s: freeing b_frozen_data\n", __func__);
- jbd_free(jh->b_frozen_data, bh->b_size);
- }
- if (jh->b_committed_data) {
- printk(KERN_WARNING "%s: freeing b_committed_data\n", __func__);
- jbd_free(jh->b_committed_data, bh->b_size);
- }
- bh->b_private = NULL;
- jh->b_bh = NULL; /* debug, really */
- clear_buffer_jbd(bh);
- journal_free_journal_head(jh);
-}
-
-/*
- * Drop a reference on the passed journal_head. If it fell to zero then
- * release the journal_head from the buffer_head.
- */
-void journal_put_journal_head(struct journal_head *jh)
-{
- struct buffer_head *bh = jh2bh(jh);
-
- jbd_lock_bh_journal_head(bh);
- J_ASSERT_JH(jh, jh->b_jcount > 0);
- --jh->b_jcount;
- if (!jh->b_jcount) {
- __journal_remove_journal_head(bh);
- jbd_unlock_bh_journal_head(bh);
- __brelse(bh);
- } else
- jbd_unlock_bh_journal_head(bh);
-}
-
-/*
- * debugfs tunables
- */
-#ifdef CONFIG_JBD_DEBUG
-
-u8 journal_enable_debug __read_mostly;
-EXPORT_SYMBOL(journal_enable_debug);
-
-static struct dentry *jbd_debugfs_dir;
-static struct dentry *jbd_debug;
-
-static void __init jbd_create_debugfs_entry(void)
-{
- jbd_debugfs_dir = debugfs_create_dir("jbd", NULL);
- if (jbd_debugfs_dir)
- jbd_debug = debugfs_create_u8("jbd-debug", S_IRUGO | S_IWUSR,
- jbd_debugfs_dir,
- &journal_enable_debug);
-}
-
-static void __exit jbd_remove_debugfs_entry(void)
-{
- debugfs_remove(jbd_debug);
- debugfs_remove(jbd_debugfs_dir);
-}
-
-#else
-
-static inline void jbd_create_debugfs_entry(void)
-{
-}
-
-static inline void jbd_remove_debugfs_entry(void)
-{
-}
-
-#endif
-
-struct kmem_cache *jbd_handle_cache;
-
-static int __init journal_init_handle_cache(void)
-{
- jbd_handle_cache = kmem_cache_create("journal_handle",
- sizeof(handle_t),
- 0, /* offset */
- SLAB_TEMPORARY, /* flags */
- NULL); /* ctor */
- if (jbd_handle_cache == NULL) {
- printk(KERN_EMERG "JBD: failed to create handle cache\n");
- return -ENOMEM;
- }
- return 0;
-}
-
-static void journal_destroy_handle_cache(void)
-{
- if (jbd_handle_cache)
- kmem_cache_destroy(jbd_handle_cache);
-}
-
-/*
- * Module startup and shutdown
- */
-
-static int __init journal_init_caches(void)
-{
- int ret;
-
- ret = journal_init_revoke_caches();
- if (ret == 0)
- ret = journal_init_journal_head_cache();
- if (ret == 0)
- ret = journal_init_handle_cache();
- return ret;
-}
-
-static void journal_destroy_caches(void)
-{
- journal_destroy_revoke_caches();
- journal_destroy_journal_head_cache();
- journal_destroy_handle_cache();
-}
-
-static int __init journal_init(void)
-{
- int ret;
-
- BUILD_BUG_ON(sizeof(struct journal_superblock_s) != 1024);
-
- ret = journal_init_caches();
- if (ret != 0)
- journal_destroy_caches();
- jbd_create_debugfs_entry();
- return ret;
-}
-
-static void __exit journal_exit(void)
-{
-#ifdef CONFIG_JBD_DEBUG
- int n = atomic_read(&nr_journal_heads);
- if (n)
- printk(KERN_ERR "JBD: leaked %d journal_heads!\n", n);
-#endif
- jbd_remove_debugfs_entry();
- journal_destroy_caches();
-}
-
-MODULE_LICENSE("GPL");
-module_init(journal_init);
-module_exit(journal_exit);
-
diff --git a/kernel/fs/jbd/recovery.c b/kernel/fs/jbd/recovery.c
deleted file mode 100644
index a748fe214..000000000
--- a/kernel/fs/jbd/recovery.c
+++ /dev/null
@@ -1,594 +0,0 @@
-/*
- * linux/fs/jbd/recovery.c
- *
- * Written by Stephen C. Tweedie <sct@redhat.com>, 1999
- *
- * Copyright 1999-2000 Red Hat Software --- All Rights Reserved
- *
- * This file is part of the Linux kernel and is made available under
- * the terms of the GNU General Public License, version 2, or at your
- * option, any later version, incorporated herein by reference.
- *
- * Journal recovery routines for the generic filesystem journaling code;
- * part of the ext2fs journaling system.
- */
-
-#ifndef __KERNEL__
-#include "jfs_user.h"
-#else
-#include <linux/time.h>
-#include <linux/fs.h>
-#include <linux/jbd.h>
-#include <linux/errno.h>
-#include <linux/blkdev.h>
-#endif
-
-/*
- * Maintain information about the progress of the recovery job, so that
- * the different passes can carry information between them.
- */
-struct recovery_info
-{
- tid_t start_transaction;
- tid_t end_transaction;
-
- int nr_replays;
- int nr_revokes;
- int nr_revoke_hits;
-};
-
-enum passtype {PASS_SCAN, PASS_REVOKE, PASS_REPLAY};
-static int do_one_pass(journal_t *journal,
- struct recovery_info *info, enum passtype pass);
-static int scan_revoke_records(journal_t *, struct buffer_head *,
- tid_t, struct recovery_info *);
-
-#ifdef __KERNEL__
-
-/* Release readahead buffers after use */
-static void journal_brelse_array(struct buffer_head *b[], int n)
-{
- while (--n >= 0)
- brelse (b[n]);
-}
-
-
-/*
- * When reading from the journal, we are going through the block device
- * layer directly and so there is no readahead being done for us. We
- * need to implement any readahead ourselves if we want it to happen at
- * all. Recovery is basically one long sequential read, so make sure we
- * do the IO in reasonably large chunks.
- *
- * This is not so critical that we need to be enormously clever about
- * the readahead size, though. 128K is a purely arbitrary, good-enough
- * fixed value.
- */
-
-#define MAXBUF 8
-static int do_readahead(journal_t *journal, unsigned int start)
-{
- int err;
- unsigned int max, nbufs, next;
- unsigned int blocknr;
- struct buffer_head *bh;
-
- struct buffer_head * bufs[MAXBUF];
-
- /* Do up to 128K of readahead */
- max = start + (128 * 1024 / journal->j_blocksize);
- if (max > journal->j_maxlen)
- max = journal->j_maxlen;
-
- /* Do the readahead itself. We'll submit MAXBUF buffer_heads at
- * a time to the block device IO layer. */
-
- nbufs = 0;
-
- for (next = start; next < max; next++) {
- err = journal_bmap(journal, next, &blocknr);
-
- if (err) {
- printk (KERN_ERR "JBD: bad block at offset %u\n",
- next);
- goto failed;
- }
-
- bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
- if (!bh) {
- err = -ENOMEM;
- goto failed;
- }
-
- if (!buffer_uptodate(bh) && !buffer_locked(bh)) {
- bufs[nbufs++] = bh;
- if (nbufs == MAXBUF) {
- ll_rw_block(READ, nbufs, bufs);
- journal_brelse_array(bufs, nbufs);
- nbufs = 0;
- }
- } else
- brelse(bh);
- }
-
- if (nbufs)
- ll_rw_block(READ, nbufs, bufs);
- err = 0;
-
-failed:
- if (nbufs)
- journal_brelse_array(bufs, nbufs);
- return err;
-}
-
-#endif /* __KERNEL__ */
-
-
-/*
- * Read a block from the journal
- */
-
-static int jread(struct buffer_head **bhp, journal_t *journal,
- unsigned int offset)
-{
- int err;
- unsigned int blocknr;
- struct buffer_head *bh;
-
- *bhp = NULL;
-
- if (offset >= journal->j_maxlen) {
- printk(KERN_ERR "JBD: corrupted journal superblock\n");
- return -EIO;
- }
-
- err = journal_bmap(journal, offset, &blocknr);
-
- if (err) {
- printk (KERN_ERR "JBD: bad block at offset %u\n",
- offset);
- return err;
- }
-
- bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
- if (!bh)
- return -ENOMEM;
-
- if (!buffer_uptodate(bh)) {
- /* If this is a brand new buffer, start readahead.
- Otherwise, we assume we are already reading it. */
- if (!buffer_req(bh))
- do_readahead(journal, offset);
- wait_on_buffer(bh);
- }
-
- if (!buffer_uptodate(bh)) {
- printk (KERN_ERR "JBD: Failed to read block at offset %u\n",
- offset);
- brelse(bh);
- return -EIO;
- }
-
- *bhp = bh;
- return 0;
-}
-
-
-/*
- * Count the number of in-use tags in a journal descriptor block.
- */
-
-static int count_tags(struct buffer_head *bh, int size)
-{
- char * tagp;
- journal_block_tag_t * tag;
- int nr = 0;
-
- tagp = &bh->b_data[sizeof(journal_header_t)];
-
- while ((tagp - bh->b_data + sizeof(journal_block_tag_t)) <= size) {
- tag = (journal_block_tag_t *) tagp;
-
- nr++;
- tagp += sizeof(journal_block_tag_t);
- if (!(tag->t_flags & cpu_to_be32(JFS_FLAG_SAME_UUID)))
- tagp += 16;
-
- if (tag->t_flags & cpu_to_be32(JFS_FLAG_LAST_TAG))
- break;
- }
-
- return nr;
-}
-
-
-/* Make sure we wrap around the log correctly! */
-#define wrap(journal, var) \
-do { \
- if (var >= (journal)->j_last) \
- var -= ((journal)->j_last - (journal)->j_first); \
-} while (0)
-
-/**
- * journal_recover - recovers a on-disk journal
- * @journal: the journal to recover
- *
- * The primary function for recovering the log contents when mounting a
- * journaled device.
- *
- * Recovery is done in three passes. In the first pass, we look for the
- * end of the log. In the second, we assemble the list of revoke
- * blocks. In the third and final pass, we replay any un-revoked blocks
- * in the log.
- */
-int journal_recover(journal_t *journal)
-{
- int err, err2;
- journal_superblock_t * sb;
-
- struct recovery_info info;
-
- memset(&info, 0, sizeof(info));
- sb = journal->j_superblock;
-
- /*
- * The journal superblock's s_start field (the current log head)
- * is always zero if, and only if, the journal was cleanly
- * unmounted.
- */
-
- if (!sb->s_start) {
- jbd_debug(1, "No recovery required, last transaction %d\n",
- be32_to_cpu(sb->s_sequence));
- journal->j_transaction_sequence = be32_to_cpu(sb->s_sequence) + 1;
- return 0;
- }
-
- err = do_one_pass(journal, &info, PASS_SCAN);
- if (!err)
- err = do_one_pass(journal, &info, PASS_REVOKE);
- if (!err)
- err = do_one_pass(journal, &info, PASS_REPLAY);
-
- jbd_debug(1, "JBD: recovery, exit status %d, "
- "recovered transactions %u to %u\n",
- err, info.start_transaction, info.end_transaction);
- jbd_debug(1, "JBD: Replayed %d and revoked %d/%d blocks\n",
- info.nr_replays, info.nr_revoke_hits, info.nr_revokes);
-
- /* Restart the log at the next transaction ID, thus invalidating
- * any existing commit records in the log. */
- journal->j_transaction_sequence = ++info.end_transaction;
-
- journal_clear_revoke(journal);
- err2 = sync_blockdev(journal->j_fs_dev);
- if (!err)
- err = err2;
- /* Flush disk caches to get replayed data on the permanent storage */
- if (journal->j_flags & JFS_BARRIER) {
- err2 = blkdev_issue_flush(journal->j_fs_dev, GFP_KERNEL, NULL);
- if (!err)
- err = err2;
- }
-
- return err;
-}
-
-/**
- * journal_skip_recovery - Start journal and wipe exiting records
- * @journal: journal to startup
- *
- * Locate any valid recovery information from the journal and set up the
- * journal structures in memory to ignore it (presumably because the
- * caller has evidence that it is out of date).
- * This function does'nt appear to be exorted..
- *
- * We perform one pass over the journal to allow us to tell the user how
- * much recovery information is being erased, and to let us initialise
- * the journal transaction sequence numbers to the next unused ID.
- */
-int journal_skip_recovery(journal_t *journal)
-{
- int err;
- struct recovery_info info;
-
- memset (&info, 0, sizeof(info));
-
- err = do_one_pass(journal, &info, PASS_SCAN);
-
- if (err) {
- printk(KERN_ERR "JBD: error %d scanning journal\n", err);
- ++journal->j_transaction_sequence;
- } else {
-#ifdef CONFIG_JBD_DEBUG
- int dropped = info.end_transaction -
- be32_to_cpu(journal->j_superblock->s_sequence);
- jbd_debug(1,
- "JBD: ignoring %d transaction%s from the journal.\n",
- dropped, (dropped == 1) ? "" : "s");
-#endif
- journal->j_transaction_sequence = ++info.end_transaction;
- }
-
- journal->j_tail = 0;
- return err;
-}
-
-static int do_one_pass(journal_t *journal,
- struct recovery_info *info, enum passtype pass)
-{
- unsigned int first_commit_ID, next_commit_ID;
- unsigned int next_log_block;
- int err, success = 0;
- journal_superblock_t * sb;
- journal_header_t * tmp;
- struct buffer_head * bh;
- unsigned int sequence;
- int blocktype;
-
- /*
- * First thing is to establish what we expect to find in the log
- * (in terms of transaction IDs), and where (in terms of log
- * block offsets): query the superblock.
- */
-
- sb = journal->j_superblock;
- next_commit_ID = be32_to_cpu(sb->s_sequence);
- next_log_block = be32_to_cpu(sb->s_start);
-
- first_commit_ID = next_commit_ID;
- if (pass == PASS_SCAN)
- info->start_transaction = first_commit_ID;
-
- jbd_debug(1, "Starting recovery pass %d\n", pass);
-
- /*
- * Now we walk through the log, transaction by transaction,
- * making sure that each transaction has a commit block in the
- * expected place. Each complete transaction gets replayed back
- * into the main filesystem.
- */
-
- while (1) {
- int flags;
- char * tagp;
- journal_block_tag_t * tag;
- struct buffer_head * obh;
- struct buffer_head * nbh;
-
- cond_resched();
-
- /* If we already know where to stop the log traversal,
- * check right now that we haven't gone past the end of
- * the log. */
-
- if (pass != PASS_SCAN)
- if (tid_geq(next_commit_ID, info->end_transaction))
- break;
-
- jbd_debug(2, "Scanning for sequence ID %u at %u/%u\n",
- next_commit_ID, next_log_block, journal->j_last);
-
- /* Skip over each chunk of the transaction looking
- * either the next descriptor block or the final commit
- * record. */
-
- jbd_debug(3, "JBD: checking block %u\n", next_log_block);
- err = jread(&bh, journal, next_log_block);
- if (err)
- goto failed;
-
- next_log_block++;
- wrap(journal, next_log_block);
-
- /* What kind of buffer is it?
- *
- * If it is a descriptor block, check that it has the
- * expected sequence number. Otherwise, we're all done
- * here. */
-
- tmp = (journal_header_t *)bh->b_data;
-
- if (tmp->h_magic != cpu_to_be32(JFS_MAGIC_NUMBER)) {
- brelse(bh);
- break;
- }
-
- blocktype = be32_to_cpu(tmp->h_blocktype);
- sequence = be32_to_cpu(tmp->h_sequence);
- jbd_debug(3, "Found magic %d, sequence %d\n",
- blocktype, sequence);
-
- if (sequence != next_commit_ID) {
- brelse(bh);
- break;
- }
-
- /* OK, we have a valid descriptor block which matches
- * all of the sequence number checks. What are we going
- * to do with it? That depends on the pass... */
-
- switch(blocktype) {
- case JFS_DESCRIPTOR_BLOCK:
- /* If it is a valid descriptor block, replay it
- * in pass REPLAY; otherwise, just skip over the
- * blocks it describes. */
- if (pass != PASS_REPLAY) {
- next_log_block +=
- count_tags(bh, journal->j_blocksize);
- wrap(journal, next_log_block);
- brelse(bh);
- continue;
- }
-
- /* A descriptor block: we can now write all of
- * the data blocks. Yay, useful work is finally
- * getting done here! */
-
- tagp = &bh->b_data[sizeof(journal_header_t)];
- while ((tagp - bh->b_data +sizeof(journal_block_tag_t))
- <= journal->j_blocksize) {
- unsigned int io_block;
-
- tag = (journal_block_tag_t *) tagp;
- flags = be32_to_cpu(tag->t_flags);
-
- io_block = next_log_block++;
- wrap(journal, next_log_block);
- err = jread(&obh, journal, io_block);
- if (err) {
- /* Recover what we can, but
- * report failure at the end. */
- success = err;
- printk (KERN_ERR
- "JBD: IO error %d recovering "
- "block %u in log\n",
- err, io_block);
- } else {
- unsigned int blocknr;
-
- J_ASSERT(obh != NULL);
- blocknr = be32_to_cpu(tag->t_blocknr);
-
- /* If the block has been
- * revoked, then we're all done
- * here. */
- if (journal_test_revoke
- (journal, blocknr,
- next_commit_ID)) {
- brelse(obh);
- ++info->nr_revoke_hits;
- goto skip_write;
- }
-
- /* Find a buffer for the new
- * data being restored */
- nbh = __getblk(journal->j_fs_dev,
- blocknr,
- journal->j_blocksize);
- if (nbh == NULL) {
- printk(KERN_ERR
- "JBD: Out of memory "
- "during recovery.\n");
- err = -ENOMEM;
- brelse(bh);
- brelse(obh);
- goto failed;
- }
-
- lock_buffer(nbh);
- memcpy(nbh->b_data, obh->b_data,
- journal->j_blocksize);
- if (flags & JFS_FLAG_ESCAPE) {
- *((__be32 *)nbh->b_data) =
- cpu_to_be32(JFS_MAGIC_NUMBER);
- }
-
- BUFFER_TRACE(nbh, "marking dirty");
- set_buffer_uptodate(nbh);
- mark_buffer_dirty(nbh);
- BUFFER_TRACE(nbh, "marking uptodate");
- ++info->nr_replays;
- /* ll_rw_block(WRITE, 1, &nbh); */
- unlock_buffer(nbh);
- brelse(obh);
- brelse(nbh);
- }
-
- skip_write:
- tagp += sizeof(journal_block_tag_t);
- if (!(flags & JFS_FLAG_SAME_UUID))
- tagp += 16;
-
- if (flags & JFS_FLAG_LAST_TAG)
- break;
- }
-
- brelse(bh);
- continue;
-
- case JFS_COMMIT_BLOCK:
- /* Found an expected commit block: not much to
- * do other than move on to the next sequence
- * number. */
- brelse(bh);
- next_commit_ID++;
- continue;
-
- case JFS_REVOKE_BLOCK:
- /* If we aren't in the REVOKE pass, then we can
- * just skip over this block. */
- if (pass != PASS_REVOKE) {
- brelse(bh);
- continue;
- }
-
- err = scan_revoke_records(journal, bh,
- next_commit_ID, info);
- brelse(bh);
- if (err)
- goto failed;
- continue;
-
- default:
- jbd_debug(3, "Unrecognised magic %d, end of scan.\n",
- blocktype);
- brelse(bh);
- goto done;
- }
- }
-
- done:
- /*
- * We broke out of the log scan loop: either we came to the
- * known end of the log or we found an unexpected block in the
- * log. If the latter happened, then we know that the "current"
- * transaction marks the end of the valid log.
- */
-
- if (pass == PASS_SCAN)
- info->end_transaction = next_commit_ID;
- else {
- /* It's really bad news if different passes end up at
- * different places (but possible due to IO errors). */
- if (info->end_transaction != next_commit_ID) {
- printk (KERN_ERR "JBD: recovery pass %d ended at "
- "transaction %u, expected %u\n",
- pass, next_commit_ID, info->end_transaction);
- if (!success)
- success = -EIO;
- }
- }
-
- return success;
-
- failed:
- return err;
-}
-
-
-/* Scan a revoke record, marking all blocks mentioned as revoked. */
-
-static int scan_revoke_records(journal_t *journal, struct buffer_head *bh,
- tid_t sequence, struct recovery_info *info)
-{
- journal_revoke_header_t *header;
- int offset, max;
-
- header = (journal_revoke_header_t *) bh->b_data;
- offset = sizeof(journal_revoke_header_t);
- max = be32_to_cpu(header->r_count);
-
- while (offset < max) {
- unsigned int blocknr;
- int err;
-
- blocknr = be32_to_cpu(* ((__be32 *) (bh->b_data+offset)));
- offset += 4;
- err = journal_set_revoke(journal, blocknr, sequence);
- if (err)
- return err;
- ++info->nr_revokes;
- }
- return 0;
-}
diff --git a/kernel/fs/jbd/revoke.c b/kernel/fs/jbd/revoke.c
deleted file mode 100644
index dcead636c..000000000
--- a/kernel/fs/jbd/revoke.c
+++ /dev/null
@@ -1,733 +0,0 @@
-/*
- * linux/fs/jbd/revoke.c
- *
- * Written by Stephen C. Tweedie <sct@redhat.com>, 2000
- *
- * Copyright 2000 Red Hat corp --- All Rights Reserved
- *
- * This file is part of the Linux kernel and is made available under
- * the terms of the GNU General Public License, version 2, or at your
- * option, any later version, incorporated herein by reference.
- *
- * Journal revoke routines for the generic filesystem journaling code;
- * part of the ext2fs journaling system.
- *
- * Revoke is the mechanism used to prevent old log records for deleted
- * metadata from being replayed on top of newer data using the same
- * blocks. The revoke mechanism is used in two separate places:
- *
- * + Commit: during commit we write the entire list of the current
- * transaction's revoked blocks to the journal
- *
- * + Recovery: during recovery we record the transaction ID of all
- * revoked blocks. If there are multiple revoke records in the log
- * for a single block, only the last one counts, and if there is a log
- * entry for a block beyond the last revoke, then that log entry still
- * gets replayed.
- *
- * We can get interactions between revokes and new log data within a
- * single transaction:
- *
- * Block is revoked and then journaled:
- * The desired end result is the journaling of the new block, so we
- * cancel the revoke before the transaction commits.
- *
- * Block is journaled and then revoked:
- * The revoke must take precedence over the write of the block, so we
- * need either to cancel the journal entry or to write the revoke
- * later in the log than the log block. In this case, we choose the
- * latter: journaling a block cancels any revoke record for that block
- * in the current transaction, so any revoke for that block in the
- * transaction must have happened after the block was journaled and so
- * the revoke must take precedence.
- *
- * Block is revoked and then written as data:
- * The data write is allowed to succeed, but the revoke is _not_
- * cancelled. We still need to prevent old log records from
- * overwriting the new data. We don't even need to clear the revoke
- * bit here.
- *
- * We cache revoke status of a buffer in the current transaction in b_states
- * bits. As the name says, revokevalid flag indicates that the cached revoke
- * status of a buffer is valid and we can rely on the cached status.
- *
- * Revoke information on buffers is a tri-state value:
- *
- * RevokeValid clear: no cached revoke status, need to look it up
- * RevokeValid set, Revoked clear:
- * buffer has not been revoked, and cancel_revoke
- * need do nothing.
- * RevokeValid set, Revoked set:
- * buffer has been revoked.
- *
- * Locking rules:
- * We keep two hash tables of revoke records. One hashtable belongs to the
- * running transaction (is pointed to by journal->j_revoke), the other one
- * belongs to the committing transaction. Accesses to the second hash table
- * happen only from the kjournald and no other thread touches this table. Also
- * journal_switch_revoke_table() which switches which hashtable belongs to the
- * running and which to the committing transaction is called only from
- * kjournald. Therefore we need no locks when accessing the hashtable belonging
- * to the committing transaction.
- *
- * All users operating on the hash table belonging to the running transaction
- * have a handle to the transaction. Therefore they are safe from kjournald
- * switching hash tables under them. For operations on the lists of entries in
- * the hash table j_revoke_lock is used.
- *
- * Finally, also replay code uses the hash tables but at this moment no one else
- * can touch them (filesystem isn't mounted yet) and hence no locking is
- * needed.
- */
-
-#ifndef __KERNEL__
-#include "jfs_user.h"
-#else
-#include <linux/time.h>
-#include <linux/fs.h>
-#include <linux/jbd.h>
-#include <linux/errno.h>
-#include <linux/slab.h>
-#include <linux/list.h>
-#include <linux/init.h>
-#include <linux/bio.h>
-#endif
-#include <linux/log2.h>
-#include <linux/hash.h>
-
-static struct kmem_cache *revoke_record_cache;
-static struct kmem_cache *revoke_table_cache;
-
-/* Each revoke record represents one single revoked block. During
- journal replay, this involves recording the transaction ID of the
- last transaction to revoke this block. */
-
-struct jbd_revoke_record_s
-{
- struct list_head hash;
- tid_t sequence; /* Used for recovery only */
- unsigned int blocknr;
-};
-
-
-/* The revoke table is just a simple hash table of revoke records. */
-struct jbd_revoke_table_s
-{
- /* It is conceivable that we might want a larger hash table
- * for recovery. Must be a power of two. */
- int hash_size;
- int hash_shift;
- struct list_head *hash_table;
-};
-
-
-#ifdef __KERNEL__
-static void write_one_revoke_record(journal_t *, transaction_t *,
- struct journal_head **, int *,
- struct jbd_revoke_record_s *, int);
-static void flush_descriptor(journal_t *, struct journal_head *, int, int);
-#endif
-
-/* Utility functions to maintain the revoke table */
-
-static inline int hash(journal_t *journal, unsigned int block)
-{
- struct jbd_revoke_table_s *table = journal->j_revoke;
-
- return hash_32(block, table->hash_shift);
-}
-
-static int insert_revoke_hash(journal_t *journal, unsigned int blocknr,
- tid_t seq)
-{
- struct list_head *hash_list;
- struct jbd_revoke_record_s *record;
-
-repeat:
- record = kmem_cache_alloc(revoke_record_cache, GFP_NOFS);
- if (!record)
- goto oom;
-
- record->sequence = seq;
- record->blocknr = blocknr;
- hash_list = &journal->j_revoke->hash_table[hash(journal, blocknr)];
- spin_lock(&journal->j_revoke_lock);
- list_add(&record->hash, hash_list);
- spin_unlock(&journal->j_revoke_lock);
- return 0;
-
-oom:
- if (!journal_oom_retry)
- return -ENOMEM;
- jbd_debug(1, "ENOMEM in %s, retrying\n", __func__);
- yield();
- goto repeat;
-}
-
-/* Find a revoke record in the journal's hash table. */
-
-static struct jbd_revoke_record_s *find_revoke_record(journal_t *journal,
- unsigned int blocknr)
-{
- struct list_head *hash_list;
- struct jbd_revoke_record_s *record;
-
- hash_list = &journal->j_revoke->hash_table[hash(journal, blocknr)];
-
- spin_lock(&journal->j_revoke_lock);
- record = (struct jbd_revoke_record_s *) hash_list->next;
- while (&(record->hash) != hash_list) {
- if (record->blocknr == blocknr) {
- spin_unlock(&journal->j_revoke_lock);
- return record;
- }
- record = (struct jbd_revoke_record_s *) record->hash.next;
- }
- spin_unlock(&journal->j_revoke_lock);
- return NULL;
-}
-
-void journal_destroy_revoke_caches(void)
-{
- if (revoke_record_cache) {
- kmem_cache_destroy(revoke_record_cache);
- revoke_record_cache = NULL;
- }
- if (revoke_table_cache) {
- kmem_cache_destroy(revoke_table_cache);
- revoke_table_cache = NULL;
- }
-}
-
-int __init journal_init_revoke_caches(void)
-{
- J_ASSERT(!revoke_record_cache);
- J_ASSERT(!revoke_table_cache);
-
- revoke_record_cache = kmem_cache_create("revoke_record",
- sizeof(struct jbd_revoke_record_s),
- 0,
- SLAB_HWCACHE_ALIGN|SLAB_TEMPORARY,
- NULL);
- if (!revoke_record_cache)
- goto record_cache_failure;
-
- revoke_table_cache = kmem_cache_create("revoke_table",
- sizeof(struct jbd_revoke_table_s),
- 0, SLAB_TEMPORARY, NULL);
- if (!revoke_table_cache)
- goto table_cache_failure;
-
- return 0;
-
-table_cache_failure:
- journal_destroy_revoke_caches();
-record_cache_failure:
- return -ENOMEM;
-}
-
-static struct jbd_revoke_table_s *journal_init_revoke_table(int hash_size)
-{
- int i;
- struct jbd_revoke_table_s *table;
-
- table = kmem_cache_alloc(revoke_table_cache, GFP_KERNEL);
- if (!table)
- goto out;
-
- table->hash_size = hash_size;
- table->hash_shift = ilog2(hash_size);
- table->hash_table =
- kmalloc(hash_size * sizeof(struct list_head), GFP_KERNEL);
- if (!table->hash_table) {
- kmem_cache_free(revoke_table_cache, table);
- table = NULL;
- goto out;
- }
-
- for (i = 0; i < hash_size; i++)
- INIT_LIST_HEAD(&table->hash_table[i]);
-
-out:
- return table;
-}
-
-static void journal_destroy_revoke_table(struct jbd_revoke_table_s *table)
-{
- int i;
- struct list_head *hash_list;
-
- for (i = 0; i < table->hash_size; i++) {
- hash_list = &table->hash_table[i];
- J_ASSERT(list_empty(hash_list));
- }
-
- kfree(table->hash_table);
- kmem_cache_free(revoke_table_cache, table);
-}
-
-/* Initialise the revoke table for a given journal to a given size. */
-int journal_init_revoke(journal_t *journal, int hash_size)
-{
- J_ASSERT(journal->j_revoke_table[0] == NULL);
- J_ASSERT(is_power_of_2(hash_size));
-
- journal->j_revoke_table[0] = journal_init_revoke_table(hash_size);
- if (!journal->j_revoke_table[0])
- goto fail0;
-
- journal->j_revoke_table[1] = journal_init_revoke_table(hash_size);
- if (!journal->j_revoke_table[1])
- goto fail1;
-
- journal->j_revoke = journal->j_revoke_table[1];
-
- spin_lock_init(&journal->j_revoke_lock);
-
- return 0;
-
-fail1:
- journal_destroy_revoke_table(journal->j_revoke_table[0]);
-fail0:
- return -ENOMEM;
-}
-
-/* Destroy a journal's revoke table. The table must already be empty! */
-void journal_destroy_revoke(journal_t *journal)
-{
- journal->j_revoke = NULL;
- if (journal->j_revoke_table[0])
- journal_destroy_revoke_table(journal->j_revoke_table[0]);
- if (journal->j_revoke_table[1])
- journal_destroy_revoke_table(journal->j_revoke_table[1]);
-}
-
-
-#ifdef __KERNEL__
-
-/*
- * journal_revoke: revoke a given buffer_head from the journal. This
- * prevents the block from being replayed during recovery if we take a
- * crash after this current transaction commits. Any subsequent
- * metadata writes of the buffer in this transaction cancel the
- * revoke.
- *
- * Note that this call may block --- it is up to the caller to make
- * sure that there are no further calls to journal_write_metadata
- * before the revoke is complete. In ext3, this implies calling the
- * revoke before clearing the block bitmap when we are deleting
- * metadata.
- *
- * Revoke performs a journal_forget on any buffer_head passed in as a
- * parameter, but does _not_ forget the buffer_head if the bh was only
- * found implicitly.
- *
- * bh_in may not be a journalled buffer - it may have come off
- * the hash tables without an attached journal_head.
- *
- * If bh_in is non-zero, journal_revoke() will decrement its b_count
- * by one.
- */
-
-int journal_revoke(handle_t *handle, unsigned int blocknr,
- struct buffer_head *bh_in)
-{
- struct buffer_head *bh = NULL;
- journal_t *journal;
- struct block_device *bdev;
- int err;
-
- might_sleep();
- if (bh_in)
- BUFFER_TRACE(bh_in, "enter");
-
- journal = handle->h_transaction->t_journal;
- if (!journal_set_features(journal, 0, 0, JFS_FEATURE_INCOMPAT_REVOKE)){
- J_ASSERT (!"Cannot set revoke feature!");
- return -EINVAL;
- }
-
- bdev = journal->j_fs_dev;
- bh = bh_in;
-
- if (!bh) {
- bh = __find_get_block(bdev, blocknr, journal->j_blocksize);
- if (bh)
- BUFFER_TRACE(bh, "found on hash");
- }
-#ifdef JBD_EXPENSIVE_CHECKING
- else {
- struct buffer_head *bh2;
-
- /* If there is a different buffer_head lying around in
- * memory anywhere... */
- bh2 = __find_get_block(bdev, blocknr, journal->j_blocksize);
- if (bh2) {
- /* ... and it has RevokeValid status... */
- if (bh2 != bh && buffer_revokevalid(bh2))
- /* ...then it better be revoked too,
- * since it's illegal to create a revoke
- * record against a buffer_head which is
- * not marked revoked --- that would
- * risk missing a subsequent revoke
- * cancel. */
- J_ASSERT_BH(bh2, buffer_revoked(bh2));
- put_bh(bh2);
- }
- }
-#endif
-
- /* We really ought not ever to revoke twice in a row without
- first having the revoke cancelled: it's illegal to free a
- block twice without allocating it in between! */
- if (bh) {
- if (!J_EXPECT_BH(bh, !buffer_revoked(bh),
- "inconsistent data on disk")) {
- if (!bh_in)
- brelse(bh);
- return -EIO;
- }
- set_buffer_revoked(bh);
- set_buffer_revokevalid(bh);
- if (bh_in) {
- BUFFER_TRACE(bh_in, "call journal_forget");
- journal_forget(handle, bh_in);
- } else {
- BUFFER_TRACE(bh, "call brelse");
- __brelse(bh);
- }
- }
-
- jbd_debug(2, "insert revoke for block %u, bh_in=%p\n", blocknr, bh_in);
- err = insert_revoke_hash(journal, blocknr,
- handle->h_transaction->t_tid);
- BUFFER_TRACE(bh_in, "exit");
- return err;
-}
-
-/*
- * Cancel an outstanding revoke. For use only internally by the
- * journaling code (called from journal_get_write_access).
- *
- * We trust buffer_revoked() on the buffer if the buffer is already
- * being journaled: if there is no revoke pending on the buffer, then we
- * don't do anything here.
- *
- * This would break if it were possible for a buffer to be revoked and
- * discarded, and then reallocated within the same transaction. In such
- * a case we would have lost the revoked bit, but when we arrived here
- * the second time we would still have a pending revoke to cancel. So,
- * do not trust the Revoked bit on buffers unless RevokeValid is also
- * set.
- */
-int journal_cancel_revoke(handle_t *handle, struct journal_head *jh)
-{
- struct jbd_revoke_record_s *record;
- journal_t *journal = handle->h_transaction->t_journal;
- int need_cancel;
- int did_revoke = 0; /* akpm: debug */
- struct buffer_head *bh = jh2bh(jh);
-
- jbd_debug(4, "journal_head %p, cancelling revoke\n", jh);
-
- /* Is the existing Revoke bit valid? If so, we trust it, and
- * only perform the full cancel if the revoke bit is set. If
- * not, we can't trust the revoke bit, and we need to do the
- * full search for a revoke record. */
- if (test_set_buffer_revokevalid(bh)) {
- need_cancel = test_clear_buffer_revoked(bh);
- } else {
- need_cancel = 1;
- clear_buffer_revoked(bh);
- }
-
- if (need_cancel) {
- record = find_revoke_record(journal, bh->b_blocknr);
- if (record) {
- jbd_debug(4, "cancelled existing revoke on "
- "blocknr %llu\n", (unsigned long long)bh->b_blocknr);
- spin_lock(&journal->j_revoke_lock);
- list_del(&record->hash);
- spin_unlock(&journal->j_revoke_lock);
- kmem_cache_free(revoke_record_cache, record);
- did_revoke = 1;
- }
- }
-
-#ifdef JBD_EXPENSIVE_CHECKING
- /* There better not be one left behind by now! */
- record = find_revoke_record(journal, bh->b_blocknr);
- J_ASSERT_JH(jh, record == NULL);
-#endif
-
- /* Finally, have we just cleared revoke on an unhashed
- * buffer_head? If so, we'd better make sure we clear the
- * revoked status on any hashed alias too, otherwise the revoke
- * state machine will get very upset later on. */
- if (need_cancel) {
- struct buffer_head *bh2;
- bh2 = __find_get_block(bh->b_bdev, bh->b_blocknr, bh->b_size);
- if (bh2) {
- if (bh2 != bh)
- clear_buffer_revoked(bh2);
- __brelse(bh2);
- }
- }
- return did_revoke;
-}
-
-/*
- * journal_clear_revoked_flags clears revoked flag of buffers in
- * revoke table to reflect there is no revoked buffer in the next
- * transaction which is going to be started.
- */
-void journal_clear_buffer_revoked_flags(journal_t *journal)
-{
- struct jbd_revoke_table_s *revoke = journal->j_revoke;
- int i = 0;
-
- for (i = 0; i < revoke->hash_size; i++) {
- struct list_head *hash_list;
- struct list_head *list_entry;
- hash_list = &revoke->hash_table[i];
-
- list_for_each(list_entry, hash_list) {
- struct jbd_revoke_record_s *record;
- struct buffer_head *bh;
- record = (struct jbd_revoke_record_s *)list_entry;
- bh = __find_get_block(journal->j_fs_dev,
- record->blocknr,
- journal->j_blocksize);
- if (bh) {
- clear_buffer_revoked(bh);
- __brelse(bh);
- }
- }
- }
-}
-
-/* journal_switch_revoke table select j_revoke for next transaction
- * we do not want to suspend any processing until all revokes are
- * written -bzzz
- */
-void journal_switch_revoke_table(journal_t *journal)
-{
- int i;
-
- if (journal->j_revoke == journal->j_revoke_table[0])
- journal->j_revoke = journal->j_revoke_table[1];
- else
- journal->j_revoke = journal->j_revoke_table[0];
-
- for (i = 0; i < journal->j_revoke->hash_size; i++)
- INIT_LIST_HEAD(&journal->j_revoke->hash_table[i]);
-}
-
-/*
- * Write revoke records to the journal for all entries in the current
- * revoke hash, deleting the entries as we go.
- */
-void journal_write_revoke_records(journal_t *journal,
- transaction_t *transaction, int write_op)
-{
- struct journal_head *descriptor;
- struct jbd_revoke_record_s *record;
- struct jbd_revoke_table_s *revoke;
- struct list_head *hash_list;
- int i, offset, count;
-
- descriptor = NULL;
- offset = 0;
- count = 0;
-
- /* select revoke table for committing transaction */
- revoke = journal->j_revoke == journal->j_revoke_table[0] ?
- journal->j_revoke_table[1] : journal->j_revoke_table[0];
-
- for (i = 0; i < revoke->hash_size; i++) {
- hash_list = &revoke->hash_table[i];
-
- while (!list_empty(hash_list)) {
- record = (struct jbd_revoke_record_s *)
- hash_list->next;
- write_one_revoke_record(journal, transaction,
- &descriptor, &offset,
- record, write_op);
- count++;
- list_del(&record->hash);
- kmem_cache_free(revoke_record_cache, record);
- }
- }
- if (descriptor)
- flush_descriptor(journal, descriptor, offset, write_op);
- jbd_debug(1, "Wrote %d revoke records\n", count);
-}
-
-/*
- * Write out one revoke record. We need to create a new descriptor
- * block if the old one is full or if we have not already created one.
- */
-
-static void write_one_revoke_record(journal_t *journal,
- transaction_t *transaction,
- struct journal_head **descriptorp,
- int *offsetp,
- struct jbd_revoke_record_s *record,
- int write_op)
-{
- struct journal_head *descriptor;
- int offset;
- journal_header_t *header;
-
- /* If we are already aborting, this all becomes a noop. We
- still need to go round the loop in
- journal_write_revoke_records in order to free all of the
- revoke records: only the IO to the journal is omitted. */
- if (is_journal_aborted(journal))
- return;
-
- descriptor = *descriptorp;
- offset = *offsetp;
-
- /* Make sure we have a descriptor with space left for the record */
- if (descriptor) {
- if (offset == journal->j_blocksize) {
- flush_descriptor(journal, descriptor, offset, write_op);
- descriptor = NULL;
- }
- }
-
- if (!descriptor) {
- descriptor = journal_get_descriptor_buffer(journal);
- if (!descriptor)
- return;
- header = (journal_header_t *) &jh2bh(descriptor)->b_data[0];
- header->h_magic = cpu_to_be32(JFS_MAGIC_NUMBER);
- header->h_blocktype = cpu_to_be32(JFS_REVOKE_BLOCK);
- header->h_sequence = cpu_to_be32(transaction->t_tid);
-
- /* Record it so that we can wait for IO completion later */
- JBUFFER_TRACE(descriptor, "file as BJ_LogCtl");
- journal_file_buffer(descriptor, transaction, BJ_LogCtl);
-
- offset = sizeof(journal_revoke_header_t);
- *descriptorp = descriptor;
- }
-
- * ((__be32 *)(&jh2bh(descriptor)->b_data[offset])) =
- cpu_to_be32(record->blocknr);
- offset += 4;
- *offsetp = offset;
-}
-
-/*
- * Flush a revoke descriptor out to the journal. If we are aborting,
- * this is a noop; otherwise we are generating a buffer which needs to
- * be waited for during commit, so it has to go onto the appropriate
- * journal buffer list.
- */
-
-static void flush_descriptor(journal_t *journal,
- struct journal_head *descriptor,
- int offset, int write_op)
-{
- journal_revoke_header_t *header;
- struct buffer_head *bh = jh2bh(descriptor);
-
- if (is_journal_aborted(journal)) {
- put_bh(bh);
- return;
- }
-
- header = (journal_revoke_header_t *) jh2bh(descriptor)->b_data;
- header->r_count = cpu_to_be32(offset);
- set_buffer_jwrite(bh);
- BUFFER_TRACE(bh, "write");
- set_buffer_dirty(bh);
- write_dirty_buffer(bh, write_op);
-}
-#endif
-
-/*
- * Revoke support for recovery.
- *
- * Recovery needs to be able to:
- *
- * record all revoke records, including the tid of the latest instance
- * of each revoke in the journal
- *
- * check whether a given block in a given transaction should be replayed
- * (ie. has not been revoked by a revoke record in that or a subsequent
- * transaction)
- *
- * empty the revoke table after recovery.
- */
-
-/*
- * First, setting revoke records. We create a new revoke record for
- * every block ever revoked in the log as we scan it for recovery, and
- * we update the existing records if we find multiple revokes for a
- * single block.
- */
-
-int journal_set_revoke(journal_t *journal,
- unsigned int blocknr,
- tid_t sequence)
-{
- struct jbd_revoke_record_s *record;
-
- record = find_revoke_record(journal, blocknr);
- if (record) {
- /* If we have multiple occurrences, only record the
- * latest sequence number in the hashed record */
- if (tid_gt(sequence, record->sequence))
- record->sequence = sequence;
- return 0;
- }
- return insert_revoke_hash(journal, blocknr, sequence);
-}
-
-/*
- * Test revoke records. For a given block referenced in the log, has
- * that block been revoked? A revoke record with a given transaction
- * sequence number revokes all blocks in that transaction and earlier
- * ones, but later transactions still need replayed.
- */
-
-int journal_test_revoke(journal_t *journal,
- unsigned int blocknr,
- tid_t sequence)
-{
- struct jbd_revoke_record_s *record;
-
- record = find_revoke_record(journal, blocknr);
- if (!record)
- return 0;
- if (tid_gt(sequence, record->sequence))
- return 0;
- return 1;
-}
-
-/*
- * Finally, once recovery is over, we need to clear the revoke table so
- * that it can be reused by the running filesystem.
- */
-
-void journal_clear_revoke(journal_t *journal)
-{
- int i;
- struct list_head *hash_list;
- struct jbd_revoke_record_s *record;
- struct jbd_revoke_table_s *revoke;
-
- revoke = journal->j_revoke;
-
- for (i = 0; i < revoke->hash_size; i++) {
- hash_list = &revoke->hash_table[i];
- while (!list_empty(hash_list)) {
- record = (struct jbd_revoke_record_s*) hash_list->next;
- list_del(&record->hash);
- kmem_cache_free(revoke_record_cache, record);
- }
- }
-}
diff --git a/kernel/fs/jbd/transaction.c b/kernel/fs/jbd/transaction.c
deleted file mode 100644
index 1695ba833..000000000
--- a/kernel/fs/jbd/transaction.c
+++ /dev/null
@@ -1,2237 +0,0 @@
-/*
- * linux/fs/jbd/transaction.c
- *
- * Written by Stephen C. Tweedie <sct@redhat.com>, 1998
- *
- * Copyright 1998 Red Hat corp --- All Rights Reserved
- *
- * This file is part of the Linux kernel and is made available under
- * the terms of the GNU General Public License, version 2, or at your
- * option, any later version, incorporated herein by reference.
- *
- * Generic filesystem transaction handling code; part of the ext2fs
- * journaling system.
- *
- * This file manages transactions (compound commits managed by the
- * journaling code) and handles (individual atomic operations by the
- * filesystem).
- */
-
-#include <linux/time.h>
-#include <linux/fs.h>
-#include <linux/jbd.h>
-#include <linux/errno.h>
-#include <linux/slab.h>
-#include <linux/timer.h>
-#include <linux/mm.h>
-#include <linux/highmem.h>
-#include <linux/hrtimer.h>
-
-static void __journal_temp_unlink_buffer(struct journal_head *jh);
-
-/*
- * get_transaction: obtain a new transaction_t object.
- *
- * Simply allocate and initialise a new transaction. Create it in
- * RUNNING state and add it to the current journal (which should not
- * have an existing running transaction: we only make a new transaction
- * once we have started to commit the old one).
- *
- * Preconditions:
- * The journal MUST be locked. We don't perform atomic mallocs on the
- * new transaction and we can't block without protecting against other
- * processes trying to touch the journal while it is in transition.
- *
- * Called under j_state_lock
- */
-
-static transaction_t *
-get_transaction(journal_t *journal, transaction_t *transaction)
-{
- transaction->t_journal = journal;
- transaction->t_state = T_RUNNING;
- transaction->t_start_time = ktime_get();
- transaction->t_tid = journal->j_transaction_sequence++;
- transaction->t_expires = jiffies + journal->j_commit_interval;
- spin_lock_init(&transaction->t_handle_lock);
-
- /* Set up the commit timer for the new transaction. */
- journal->j_commit_timer.expires =
- round_jiffies_up(transaction->t_expires);
- add_timer(&journal->j_commit_timer);
-
- J_ASSERT(journal->j_running_transaction == NULL);
- journal->j_running_transaction = transaction;
-
- return transaction;
-}
-
-/*
- * Handle management.
- *
- * A handle_t is an object which represents a single atomic update to a
- * filesystem, and which tracks all of the modifications which form part
- * of that one update.
- */
-
-/*
- * start_this_handle: Given a handle, deal with any locking or stalling
- * needed to make sure that there is enough journal space for the handle
- * to begin. Attach the handle to a transaction and set up the
- * transaction's buffer credits.
- */
-
-static int start_this_handle(journal_t *journal, handle_t *handle)
-{
- transaction_t *transaction;
- int needed;
- int nblocks = handle->h_buffer_credits;
- transaction_t *new_transaction = NULL;
- int ret = 0;
-
- if (nblocks > journal->j_max_transaction_buffers) {
- printk(KERN_ERR "JBD: %s wants too many credits (%d > %d)\n",
- current->comm, nblocks,
- journal->j_max_transaction_buffers);
- ret = -ENOSPC;
- goto out;
- }
-
-alloc_transaction:
- if (!journal->j_running_transaction) {
- new_transaction = kzalloc(sizeof(*new_transaction),
- GFP_NOFS|__GFP_NOFAIL);
- if (!new_transaction) {
- ret = -ENOMEM;
- goto out;
- }
- }
-
- jbd_debug(3, "New handle %p going live.\n", handle);
-
-repeat:
-
- /*
- * We need to hold j_state_lock until t_updates has been incremented,
- * for proper journal barrier handling
- */
- spin_lock(&journal->j_state_lock);
-repeat_locked:
- if (is_journal_aborted(journal) ||
- (journal->j_errno != 0 && !(journal->j_flags & JFS_ACK_ERR))) {
- spin_unlock(&journal->j_state_lock);
- ret = -EROFS;
- goto out;
- }
-
- /* Wait on the journal's transaction barrier if necessary */
- if (journal->j_barrier_count) {
- spin_unlock(&journal->j_state_lock);
- wait_event(journal->j_wait_transaction_locked,
- journal->j_barrier_count == 0);
- goto repeat;
- }
-
- if (!journal->j_running_transaction) {
- if (!new_transaction) {
- spin_unlock(&journal->j_state_lock);
- goto alloc_transaction;
- }
- get_transaction(journal, new_transaction);
- new_transaction = NULL;
- }
-
- transaction = journal->j_running_transaction;
-
- /*
- * If the current transaction is locked down for commit, wait for the
- * lock to be released.
- */
- if (transaction->t_state == T_LOCKED) {
- DEFINE_WAIT(wait);
-
- prepare_to_wait(&journal->j_wait_transaction_locked,
- &wait, TASK_UNINTERRUPTIBLE);
- spin_unlock(&journal->j_state_lock);
- schedule();
- finish_wait(&journal->j_wait_transaction_locked, &wait);
- goto repeat;
- }
-
- /*
- * If there is not enough space left in the log to write all potential
- * buffers requested by this operation, we need to stall pending a log
- * checkpoint to free some more log space.
- */
- spin_lock(&transaction->t_handle_lock);
- needed = transaction->t_outstanding_credits + nblocks;
-
- if (needed > journal->j_max_transaction_buffers) {
- /*
- * If the current transaction is already too large, then start
- * to commit it: we can then go back and attach this handle to
- * a new transaction.
- */
- DEFINE_WAIT(wait);
-
- jbd_debug(2, "Handle %p starting new commit...\n", handle);
- spin_unlock(&transaction->t_handle_lock);
- prepare_to_wait(&journal->j_wait_transaction_locked, &wait,
- TASK_UNINTERRUPTIBLE);
- __log_start_commit(journal, transaction->t_tid);
- spin_unlock(&journal->j_state_lock);
- schedule();
- finish_wait(&journal->j_wait_transaction_locked, &wait);
- goto repeat;
- }
-
- /*
- * The commit code assumes that it can get enough log space
- * without forcing a checkpoint. This is *critical* for
- * correctness: a checkpoint of a buffer which is also
- * associated with a committing transaction creates a deadlock,
- * so commit simply cannot force through checkpoints.
- *
- * We must therefore ensure the necessary space in the journal
- * *before* starting to dirty potentially checkpointed buffers
- * in the new transaction.
- *
- * The worst part is, any transaction currently committing can
- * reduce the free space arbitrarily. Be careful to account for
- * those buffers when checkpointing.
- */
-
- /*
- * @@@ AKPM: This seems rather over-defensive. We're giving commit
- * a _lot_ of headroom: 1/4 of the journal plus the size of
- * the committing transaction. Really, we only need to give it
- * committing_transaction->t_outstanding_credits plus "enough" for
- * the log control blocks.
- * Also, this test is inconsistent with the matching one in
- * journal_extend().
- */
- if (__log_space_left(journal) < jbd_space_needed(journal)) {
- jbd_debug(2, "Handle %p waiting for checkpoint...\n", handle);
- spin_unlock(&transaction->t_handle_lock);
- __log_wait_for_space(journal);
- goto repeat_locked;
- }
-
- /* OK, account for the buffers that this operation expects to
- * use and add the handle to the running transaction. */
-
- handle->h_transaction = transaction;
- transaction->t_outstanding_credits += nblocks;
- transaction->t_updates++;
- transaction->t_handle_count++;
- jbd_debug(4, "Handle %p given %d credits (total %d, free %d)\n",
- handle, nblocks, transaction->t_outstanding_credits,
- __log_space_left(journal));
- spin_unlock(&transaction->t_handle_lock);
- spin_unlock(&journal->j_state_lock);
-
- lock_map_acquire(&handle->h_lockdep_map);
-out:
- if (unlikely(new_transaction)) /* It's usually NULL */
- kfree(new_transaction);
- return ret;
-}
-
-static struct lock_class_key jbd_handle_key;
-
-/* Allocate a new handle. This should probably be in a slab... */
-static handle_t *new_handle(int nblocks)
-{
- handle_t *handle = jbd_alloc_handle(GFP_NOFS);
- if (!handle)
- return NULL;
- handle->h_buffer_credits = nblocks;
- handle->h_ref = 1;
-
- lockdep_init_map(&handle->h_lockdep_map, "jbd_handle", &jbd_handle_key, 0);
-
- return handle;
-}
-
-/**
- * handle_t *journal_start() - Obtain a new handle.
- * @journal: Journal to start transaction on.
- * @nblocks: number of block buffer we might modify
- *
- * We make sure that the transaction can guarantee at least nblocks of
- * modified buffers in the log. We block until the log can guarantee
- * that much space.
- *
- * This function is visible to journal users (like ext3fs), so is not
- * called with the journal already locked.
- *
- * Return a pointer to a newly allocated handle, or an ERR_PTR() value
- * on failure.
- */
-handle_t *journal_start(journal_t *journal, int nblocks)
-{
- handle_t *handle = journal_current_handle();
- int err;
-
- if (!journal)
- return ERR_PTR(-EROFS);
-
- if (handle) {
- J_ASSERT(handle->h_transaction->t_journal == journal);
- handle->h_ref++;
- return handle;
- }
-
- handle = new_handle(nblocks);
- if (!handle)
- return ERR_PTR(-ENOMEM);
-
- current->journal_info = handle;
-
- err = start_this_handle(journal, handle);
- if (err < 0) {
- jbd_free_handle(handle);
- current->journal_info = NULL;
- handle = ERR_PTR(err);
- }
- return handle;
-}
-
-/**
- * int journal_extend() - extend buffer credits.
- * @handle: handle to 'extend'
- * @nblocks: nr blocks to try to extend by.
- *
- * Some transactions, such as large extends and truncates, can be done
- * atomically all at once or in several stages. The operation requests
- * a credit for a number of buffer modications in advance, but can
- * extend its credit if it needs more.
- *
- * journal_extend tries to give the running handle more buffer credits.
- * It does not guarantee that allocation - this is a best-effort only.
- * The calling process MUST be able to deal cleanly with a failure to
- * extend here.
- *
- * Return 0 on success, non-zero on failure.
- *
- * return code < 0 implies an error
- * return code > 0 implies normal transaction-full status.
- */
-int journal_extend(handle_t *handle, int nblocks)
-{
- transaction_t *transaction = handle->h_transaction;
- journal_t *journal = transaction->t_journal;
- int result;
- int wanted;
-
- result = -EIO;
- if (is_handle_aborted(handle))
- goto out;
-
- result = 1;
-
- spin_lock(&journal->j_state_lock);
-
- /* Don't extend a locked-down transaction! */
- if (handle->h_transaction->t_state != T_RUNNING) {
- jbd_debug(3, "denied handle %p %d blocks: "
- "transaction not running\n", handle, nblocks);
- goto error_out;
- }
-
- spin_lock(&transaction->t_handle_lock);
- wanted = transaction->t_outstanding_credits + nblocks;
-
- if (wanted > journal->j_max_transaction_buffers) {
- jbd_debug(3, "denied handle %p %d blocks: "
- "transaction too large\n", handle, nblocks);
- goto unlock;
- }
-
- if (wanted > __log_space_left(journal)) {
- jbd_debug(3, "denied handle %p %d blocks: "
- "insufficient log space\n", handle, nblocks);
- goto unlock;
- }
-
- handle->h_buffer_credits += nblocks;
- transaction->t_outstanding_credits += nblocks;
- result = 0;
-
- jbd_debug(3, "extended handle %p by %d\n", handle, nblocks);
-unlock:
- spin_unlock(&transaction->t_handle_lock);
-error_out:
- spin_unlock(&journal->j_state_lock);
-out:
- return result;
-}
-
-
-/**
- * int journal_restart() - restart a handle.
- * @handle: handle to restart
- * @nblocks: nr credits requested
- *
- * Restart a handle for a multi-transaction filesystem
- * operation.
- *
- * If the journal_extend() call above fails to grant new buffer credits
- * to a running handle, a call to journal_restart will commit the
- * handle's transaction so far and reattach the handle to a new
- * transaction capabable of guaranteeing the requested number of
- * credits.
- */
-
-int journal_restart(handle_t *handle, int nblocks)
-{
- transaction_t *transaction = handle->h_transaction;
- journal_t *journal = transaction->t_journal;
- int ret;
-
- /* If we've had an abort of any type, don't even think about
- * actually doing the restart! */
- if (is_handle_aborted(handle))
- return 0;
-
- /*
- * First unlink the handle from its current transaction, and start the
- * commit on that.
- */
- J_ASSERT(transaction->t_updates > 0);
- J_ASSERT(journal_current_handle() == handle);
-
- spin_lock(&journal->j_state_lock);
- spin_lock(&transaction->t_handle_lock);
- transaction->t_outstanding_credits -= handle->h_buffer_credits;
- transaction->t_updates--;
-
- if (!transaction->t_updates)
- wake_up(&journal->j_wait_updates);
- spin_unlock(&transaction->t_handle_lock);
-
- jbd_debug(2, "restarting handle %p\n", handle);
- __log_start_commit(journal, transaction->t_tid);
- spin_unlock(&journal->j_state_lock);
-
- lock_map_release(&handle->h_lockdep_map);
- handle->h_buffer_credits = nblocks;
- ret = start_this_handle(journal, handle);
- return ret;
-}
-
-
-/**
- * void journal_lock_updates () - establish a transaction barrier.
- * @journal: Journal to establish a barrier on.
- *
- * This locks out any further updates from being started, and blocks until all
- * existing updates have completed, returning only once the journal is in a
- * quiescent state with no updates running.
- *
- * We do not use simple mutex for synchronization as there are syscalls which
- * want to return with filesystem locked and that trips up lockdep. Also
- * hibernate needs to lock filesystem but locked mutex then blocks hibernation.
- * Since locking filesystem is rare operation, we use simple counter and
- * waitqueue for locking.
- */
-void journal_lock_updates(journal_t *journal)
-{
- DEFINE_WAIT(wait);
-
-wait:
- /* Wait for previous locked operation to finish */
- wait_event(journal->j_wait_transaction_locked,
- journal->j_barrier_count == 0);
-
- spin_lock(&journal->j_state_lock);
- /*
- * Check reliably under the lock whether we are the ones winning the race
- * and locking the journal
- */
- if (journal->j_barrier_count > 0) {
- spin_unlock(&journal->j_state_lock);
- goto wait;
- }
- ++journal->j_barrier_count;
-
- /* Wait until there are no running updates */
- while (1) {
- transaction_t *transaction = journal->j_running_transaction;
-
- if (!transaction)
- break;
-
- spin_lock(&transaction->t_handle_lock);
- if (!transaction->t_updates) {
- spin_unlock(&transaction->t_handle_lock);
- break;
- }
- prepare_to_wait(&journal->j_wait_updates, &wait,
- TASK_UNINTERRUPTIBLE);
- spin_unlock(&transaction->t_handle_lock);
- spin_unlock(&journal->j_state_lock);
- schedule();
- finish_wait(&journal->j_wait_updates, &wait);
- spin_lock(&journal->j_state_lock);
- }
- spin_unlock(&journal->j_state_lock);
-}
-
-/**
- * void journal_unlock_updates (journal_t* journal) - release barrier
- * @journal: Journal to release the barrier on.
- *
- * Release a transaction barrier obtained with journal_lock_updates().
- */
-void journal_unlock_updates (journal_t *journal)
-{
- J_ASSERT(journal->j_barrier_count != 0);
-
- spin_lock(&journal->j_state_lock);
- --journal->j_barrier_count;
- spin_unlock(&journal->j_state_lock);
- wake_up(&journal->j_wait_transaction_locked);
-}
-
-static void warn_dirty_buffer(struct buffer_head *bh)
-{
- char b[BDEVNAME_SIZE];
-
- printk(KERN_WARNING
- "JBD: Spotted dirty metadata buffer (dev = %s, blocknr = %llu). "
- "There's a risk of filesystem corruption in case of system "
- "crash.\n",
- bdevname(bh->b_bdev, b), (unsigned long long)bh->b_blocknr);
-}
-
-/*
- * If the buffer is already part of the current transaction, then there
- * is nothing we need to do. If it is already part of a prior
- * transaction which we are still committing to disk, then we need to
- * make sure that we do not overwrite the old copy: we do copy-out to
- * preserve the copy going to disk. We also account the buffer against
- * the handle's metadata buffer credits (unless the buffer is already
- * part of the transaction, that is).
- *
- */
-static int
-do_get_write_access(handle_t *handle, struct journal_head *jh,
- int force_copy)
-{
- struct buffer_head *bh;
- transaction_t *transaction;
- journal_t *journal;
- int error;
- char *frozen_buffer = NULL;
- int need_copy = 0;
-
- if (is_handle_aborted(handle))
- return -EROFS;
-
- transaction = handle->h_transaction;
- journal = transaction->t_journal;
-
- jbd_debug(5, "journal_head %p, force_copy %d\n", jh, force_copy);
-
- JBUFFER_TRACE(jh, "entry");
-repeat:
- bh = jh2bh(jh);
-
- /* @@@ Need to check for errors here at some point. */
-
- lock_buffer(bh);
- jbd_lock_bh_state(bh);
-
- /* We now hold the buffer lock so it is safe to query the buffer
- * state. Is the buffer dirty?
- *
- * If so, there are two possibilities. The buffer may be
- * non-journaled, and undergoing a quite legitimate writeback.
- * Otherwise, it is journaled, and we don't expect dirty buffers
- * in that state (the buffers should be marked JBD_Dirty
- * instead.) So either the IO is being done under our own
- * control and this is a bug, or it's a third party IO such as
- * dump(8) (which may leave the buffer scheduled for read ---
- * ie. locked but not dirty) or tune2fs (which may actually have
- * the buffer dirtied, ugh.) */
-
- if (buffer_dirty(bh)) {
- /*
- * First question: is this buffer already part of the current
- * transaction or the existing committing transaction?
- */
- if (jh->b_transaction) {
- J_ASSERT_JH(jh,
- jh->b_transaction == transaction ||
- jh->b_transaction ==
- journal->j_committing_transaction);
- if (jh->b_next_transaction)
- J_ASSERT_JH(jh, jh->b_next_transaction ==
- transaction);
- warn_dirty_buffer(bh);
- }
- /*
- * In any case we need to clean the dirty flag and we must
- * do it under the buffer lock to be sure we don't race
- * with running write-out.
- */
- JBUFFER_TRACE(jh, "Journalling dirty buffer");
- clear_buffer_dirty(bh);
- set_buffer_jbddirty(bh);
- }
-
- unlock_buffer(bh);
-
- error = -EROFS;
- if (is_handle_aborted(handle)) {
- jbd_unlock_bh_state(bh);
- goto out;
- }
- error = 0;
-
- /*
- * The buffer is already part of this transaction if b_transaction or
- * b_next_transaction points to it
- */
- if (jh->b_transaction == transaction ||
- jh->b_next_transaction == transaction)
- goto done;
-
- /*
- * this is the first time this transaction is touching this buffer,
- * reset the modified flag
- */
- jh->b_modified = 0;
-
- /*
- * If there is already a copy-out version of this buffer, then we don't
- * need to make another one
- */
- if (jh->b_frozen_data) {
- JBUFFER_TRACE(jh, "has frozen data");
- J_ASSERT_JH(jh, jh->b_next_transaction == NULL);
- jh->b_next_transaction = transaction;
- goto done;
- }
-
- /* Is there data here we need to preserve? */
-
- if (jh->b_transaction && jh->b_transaction != transaction) {
- JBUFFER_TRACE(jh, "owned by older transaction");
- J_ASSERT_JH(jh, jh->b_next_transaction == NULL);
- J_ASSERT_JH(jh, jh->b_transaction ==
- journal->j_committing_transaction);
-
- /* There is one case we have to be very careful about.
- * If the committing transaction is currently writing
- * this buffer out to disk and has NOT made a copy-out,
- * then we cannot modify the buffer contents at all
- * right now. The essence of copy-out is that it is the
- * extra copy, not the primary copy, which gets
- * journaled. If the primary copy is already going to
- * disk then we cannot do copy-out here. */
-
- if (jh->b_jlist == BJ_Shadow) {
- DEFINE_WAIT_BIT(wait, &bh->b_state, BH_Unshadow);
- wait_queue_head_t *wqh;
-
- wqh = bit_waitqueue(&bh->b_state, BH_Unshadow);
-
- JBUFFER_TRACE(jh, "on shadow: sleep");
- jbd_unlock_bh_state(bh);
- /* commit wakes up all shadow buffers after IO */
- for ( ; ; ) {
- prepare_to_wait(wqh, &wait.wait,
- TASK_UNINTERRUPTIBLE);
- if (jh->b_jlist != BJ_Shadow)
- break;
- schedule();
- }
- finish_wait(wqh, &wait.wait);
- goto repeat;
- }
-
- /* Only do the copy if the currently-owning transaction
- * still needs it. If it is on the Forget list, the
- * committing transaction is past that stage. The
- * buffer had better remain locked during the kmalloc,
- * but that should be true --- we hold the journal lock
- * still and the buffer is already on the BUF_JOURNAL
- * list so won't be flushed.
- *
- * Subtle point, though: if this is a get_undo_access,
- * then we will be relying on the frozen_data to contain
- * the new value of the committed_data record after the
- * transaction, so we HAVE to force the frozen_data copy
- * in that case. */
-
- if (jh->b_jlist != BJ_Forget || force_copy) {
- JBUFFER_TRACE(jh, "generate frozen data");
- if (!frozen_buffer) {
- JBUFFER_TRACE(jh, "allocate memory for buffer");
- jbd_unlock_bh_state(bh);
- frozen_buffer =
- jbd_alloc(jh2bh(jh)->b_size,
- GFP_NOFS);
- if (!frozen_buffer) {
- printk(KERN_ERR
- "%s: OOM for frozen_buffer\n",
- __func__);
- JBUFFER_TRACE(jh, "oom!");
- error = -ENOMEM;
- jbd_lock_bh_state(bh);
- goto done;
- }
- goto repeat;
- }
- jh->b_frozen_data = frozen_buffer;
- frozen_buffer = NULL;
- need_copy = 1;
- }
- jh->b_next_transaction = transaction;
- }
-
-
- /*
- * Finally, if the buffer is not journaled right now, we need to make
- * sure it doesn't get written to disk before the caller actually
- * commits the new data
- */
- if (!jh->b_transaction) {
- JBUFFER_TRACE(jh, "no transaction");
- J_ASSERT_JH(jh, !jh->b_next_transaction);
- JBUFFER_TRACE(jh, "file as BJ_Reserved");
- spin_lock(&journal->j_list_lock);
- __journal_file_buffer(jh, transaction, BJ_Reserved);
- spin_unlock(&journal->j_list_lock);
- }
-
-done:
- if (need_copy) {
- struct page *page;
- int offset;
- char *source;
-
- J_EXPECT_JH(jh, buffer_uptodate(jh2bh(jh)),
- "Possible IO failure.\n");
- page = jh2bh(jh)->b_page;
- offset = offset_in_page(jh2bh(jh)->b_data);
- source = kmap_atomic(page);
- memcpy(jh->b_frozen_data, source+offset, jh2bh(jh)->b_size);
- kunmap_atomic(source);
- }
- jbd_unlock_bh_state(bh);
-
- /*
- * If we are about to journal a buffer, then any revoke pending on it is
- * no longer valid
- */
- journal_cancel_revoke(handle, jh);
-
-out:
- if (unlikely(frozen_buffer)) /* It's usually NULL */
- jbd_free(frozen_buffer, bh->b_size);
-
- JBUFFER_TRACE(jh, "exit");
- return error;
-}
-
-/**
- * int journal_get_write_access() - notify intent to modify a buffer for metadata (not data) update.
- * @handle: transaction to add buffer modifications to
- * @bh: bh to be used for metadata writes
- *
- * Returns an error code or 0 on success.
- *
- * In full data journalling mode the buffer may be of type BJ_AsyncData,
- * because we're write()ing a buffer which is also part of a shared mapping.
- */
-
-int journal_get_write_access(handle_t *handle, struct buffer_head *bh)
-{
- struct journal_head *jh = journal_add_journal_head(bh);
- int rc;
-
- /* We do not want to get caught playing with fields which the
- * log thread also manipulates. Make sure that the buffer
- * completes any outstanding IO before proceeding. */
- rc = do_get_write_access(handle, jh, 0);
- journal_put_journal_head(jh);
- return rc;
-}
-
-
-/*
- * When the user wants to journal a newly created buffer_head
- * (ie. getblk() returned a new buffer and we are going to populate it
- * manually rather than reading off disk), then we need to keep the
- * buffer_head locked until it has been completely filled with new
- * data. In this case, we should be able to make the assertion that
- * the bh is not already part of an existing transaction.
- *
- * The buffer should already be locked by the caller by this point.
- * There is no lock ranking violation: it was a newly created,
- * unlocked buffer beforehand. */
-
-/**
- * int journal_get_create_access () - notify intent to use newly created bh
- * @handle: transaction to new buffer to
- * @bh: new buffer.
- *
- * Call this if you create a new bh.
- */
-int journal_get_create_access(handle_t *handle, struct buffer_head *bh)
-{
- transaction_t *transaction = handle->h_transaction;
- journal_t *journal = transaction->t_journal;
- struct journal_head *jh = journal_add_journal_head(bh);
- int err;
-
- jbd_debug(5, "journal_head %p\n", jh);
- err = -EROFS;
- if (is_handle_aborted(handle))
- goto out;
- err = 0;
-
- JBUFFER_TRACE(jh, "entry");
- /*
- * The buffer may already belong to this transaction due to pre-zeroing
- * in the filesystem's new_block code. It may also be on the previous,
- * committing transaction's lists, but it HAS to be in Forget state in
- * that case: the transaction must have deleted the buffer for it to be
- * reused here.
- */
- jbd_lock_bh_state(bh);
- spin_lock(&journal->j_list_lock);
- J_ASSERT_JH(jh, (jh->b_transaction == transaction ||
- jh->b_transaction == NULL ||
- (jh->b_transaction == journal->j_committing_transaction &&
- jh->b_jlist == BJ_Forget)));
-
- J_ASSERT_JH(jh, jh->b_next_transaction == NULL);
- J_ASSERT_JH(jh, buffer_locked(jh2bh(jh)));
-
- if (jh->b_transaction == NULL) {
- /*
- * Previous journal_forget() could have left the buffer
- * with jbddirty bit set because it was being committed. When
- * the commit finished, we've filed the buffer for
- * checkpointing and marked it dirty. Now we are reallocating
- * the buffer so the transaction freeing it must have
- * committed and so it's safe to clear the dirty bit.
- */
- clear_buffer_dirty(jh2bh(jh));
-
- /* first access by this transaction */
- jh->b_modified = 0;
-
- JBUFFER_TRACE(jh, "file as BJ_Reserved");
- __journal_file_buffer(jh, transaction, BJ_Reserved);
- } else if (jh->b_transaction == journal->j_committing_transaction) {
- /* first access by this transaction */
- jh->b_modified = 0;
-
- JBUFFER_TRACE(jh, "set next transaction");
- jh->b_next_transaction = transaction;
- }
- spin_unlock(&journal->j_list_lock);
- jbd_unlock_bh_state(bh);
-
- /*
- * akpm: I added this. ext3_alloc_branch can pick up new indirect
- * blocks which contain freed but then revoked metadata. We need
- * to cancel the revoke in case we end up freeing it yet again
- * and the reallocating as data - this would cause a second revoke,
- * which hits an assertion error.
- */
- JBUFFER_TRACE(jh, "cancelling revoke");
- journal_cancel_revoke(handle, jh);
-out:
- journal_put_journal_head(jh);
- return err;
-}
-
-/**
- * int journal_get_undo_access() - Notify intent to modify metadata with non-rewindable consequences
- * @handle: transaction
- * @bh: buffer to undo
- *
- * Sometimes there is a need to distinguish between metadata which has
- * been committed to disk and that which has not. The ext3fs code uses
- * this for freeing and allocating space, we have to make sure that we
- * do not reuse freed space until the deallocation has been committed,
- * since if we overwrote that space we would make the delete
- * un-rewindable in case of a crash.
- *
- * To deal with that, journal_get_undo_access requests write access to a
- * buffer for parts of non-rewindable operations such as delete
- * operations on the bitmaps. The journaling code must keep a copy of
- * the buffer's contents prior to the undo_access call until such time
- * as we know that the buffer has definitely been committed to disk.
- *
- * We never need to know which transaction the committed data is part
- * of, buffers touched here are guaranteed to be dirtied later and so
- * will be committed to a new transaction in due course, at which point
- * we can discard the old committed data pointer.
- *
- * Returns error number or 0 on success.
- */
-int journal_get_undo_access(handle_t *handle, struct buffer_head *bh)
-{
- int err;
- struct journal_head *jh = journal_add_journal_head(bh);
- char *committed_data = NULL;
-
- JBUFFER_TRACE(jh, "entry");
-
- /*
- * Do this first --- it can drop the journal lock, so we want to
- * make sure that obtaining the committed_data is done
- * atomically wrt. completion of any outstanding commits.
- */
- err = do_get_write_access(handle, jh, 1);
- if (err)
- goto out;
-
-repeat:
- if (!jh->b_committed_data) {
- committed_data = jbd_alloc(jh2bh(jh)->b_size, GFP_NOFS);
- if (!committed_data) {
- printk(KERN_ERR "%s: No memory for committed data\n",
- __func__);
- err = -ENOMEM;
- goto out;
- }
- }
-
- jbd_lock_bh_state(bh);
- if (!jh->b_committed_data) {
- /* Copy out the current buffer contents into the
- * preserved, committed copy. */
- JBUFFER_TRACE(jh, "generate b_committed data");
- if (!committed_data) {
- jbd_unlock_bh_state(bh);
- goto repeat;
- }
-
- jh->b_committed_data = committed_data;
- committed_data = NULL;
- memcpy(jh->b_committed_data, bh->b_data, bh->b_size);
- }
- jbd_unlock_bh_state(bh);
-out:
- journal_put_journal_head(jh);
- if (unlikely(committed_data))
- jbd_free(committed_data, bh->b_size);
- return err;
-}
-
-/**
- * int journal_dirty_data() - mark a buffer as containing dirty data to be flushed
- * @handle: transaction
- * @bh: bufferhead to mark
- *
- * Description:
- * Mark a buffer as containing dirty data which needs to be flushed before
- * we can commit the current transaction.
- *
- * The buffer is placed on the transaction's data list and is marked as
- * belonging to the transaction.
- *
- * Returns error number or 0 on success.
- *
- * journal_dirty_data() can be called via page_launder->ext3_writepage
- * by kswapd.
- */
-int journal_dirty_data(handle_t *handle, struct buffer_head *bh)
-{
- journal_t *journal = handle->h_transaction->t_journal;
- int need_brelse = 0;
- struct journal_head *jh;
- int ret = 0;
-
- if (is_handle_aborted(handle))
- return ret;
-
- jh = journal_add_journal_head(bh);
- JBUFFER_TRACE(jh, "entry");
-
- /*
- * The buffer could *already* be dirty. Writeout can start
- * at any time.
- */
- jbd_debug(4, "jh: %p, tid:%d\n", jh, handle->h_transaction->t_tid);
-
- /*
- * What if the buffer is already part of a running transaction?
- *
- * There are two cases:
- * 1) It is part of the current running transaction. Refile it,
- * just in case we have allocated it as metadata, deallocated
- * it, then reallocated it as data.
- * 2) It is part of the previous, still-committing transaction.
- * If all we want to do is to guarantee that the buffer will be
- * written to disk before this new transaction commits, then
- * being sure that the *previous* transaction has this same
- * property is sufficient for us! Just leave it on its old
- * transaction.
- *
- * In case (2), the buffer must not already exist as metadata
- * --- that would violate write ordering (a transaction is free
- * to write its data at any point, even before the previous
- * committing transaction has committed). The caller must
- * never, ever allow this to happen: there's nothing we can do
- * about it in this layer.
- */
- jbd_lock_bh_state(bh);
- spin_lock(&journal->j_list_lock);
-
- /* Now that we have bh_state locked, are we really still mapped? */
- if (!buffer_mapped(bh)) {
- JBUFFER_TRACE(jh, "unmapped buffer, bailing out");
- goto no_journal;
- }
-
- if (jh->b_transaction) {
- JBUFFER_TRACE(jh, "has transaction");
- if (jh->b_transaction != handle->h_transaction) {
- JBUFFER_TRACE(jh, "belongs to older transaction");
- J_ASSERT_JH(jh, jh->b_transaction ==
- journal->j_committing_transaction);
-
- /* @@@ IS THIS TRUE ? */
- /*
- * Not any more. Scenario: someone does a write()
- * in data=journal mode. The buffer's transaction has
- * moved into commit. Then someone does another
- * write() to the file. We do the frozen data copyout
- * and set b_next_transaction to point to j_running_t.
- * And while we're in that state, someone does a
- * writepage() in an attempt to pageout the same area
- * of the file via a shared mapping. At present that
- * calls journal_dirty_data(), and we get right here.
- * It may be too late to journal the data. Simply
- * falling through to the next test will suffice: the
- * data will be dirty and wil be checkpointed. The
- * ordering comments in the next comment block still
- * apply.
- */
- //J_ASSERT_JH(jh, jh->b_next_transaction == NULL);
-
- /*
- * If we're journalling data, and this buffer was
- * subject to a write(), it could be metadata, forget
- * or shadow against the committing transaction. Now,
- * someone has dirtied the same darn page via a mapping
- * and it is being writepage()'d.
- * We *could* just steal the page from commit, with some
- * fancy locking there. Instead, we just skip it -
- * don't tie the page's buffers to the new transaction
- * at all.
- * Implication: if we crash before the writepage() data
- * is written into the filesystem, recovery will replay
- * the write() data.
- */
- if (jh->b_jlist != BJ_None &&
- jh->b_jlist != BJ_SyncData &&
- jh->b_jlist != BJ_Locked) {
- JBUFFER_TRACE(jh, "Not stealing");
- goto no_journal;
- }
-
- /*
- * This buffer may be undergoing writeout in commit. We
- * can't return from here and let the caller dirty it
- * again because that can cause the write-out loop in
- * commit to never terminate.
- */
- if (buffer_dirty(bh)) {
- get_bh(bh);
- spin_unlock(&journal->j_list_lock);
- jbd_unlock_bh_state(bh);
- need_brelse = 1;
- sync_dirty_buffer(bh);
- jbd_lock_bh_state(bh);
- spin_lock(&journal->j_list_lock);
- /* Since we dropped the lock... */
- if (!buffer_mapped(bh)) {
- JBUFFER_TRACE(jh, "buffer got unmapped");
- goto no_journal;
- }
- /* The buffer may become locked again at any
- time if it is redirtied */
- }
-
- /*
- * We cannot remove the buffer with io error from the
- * committing transaction, because otherwise it would
- * miss the error and the commit would not abort.
- */
- if (unlikely(!buffer_uptodate(bh))) {
- ret = -EIO;
- goto no_journal;
- }
- /* We might have slept so buffer could be refiled now */
- if (jh->b_transaction != NULL &&
- jh->b_transaction != handle->h_transaction) {
- JBUFFER_TRACE(jh, "unfile from commit");
- __journal_temp_unlink_buffer(jh);
- /* It still points to the committing
- * transaction; move it to this one so
- * that the refile assert checks are
- * happy. */
- jh->b_transaction = handle->h_transaction;
- }
- /* The buffer will be refiled below */
-
- }
- /*
- * Special case --- the buffer might actually have been
- * allocated and then immediately deallocated in the previous,
- * committing transaction, so might still be left on that
- * transaction's metadata lists.
- */
- if (jh->b_jlist != BJ_SyncData && jh->b_jlist != BJ_Locked) {
- JBUFFER_TRACE(jh, "not on correct data list: unfile");
- J_ASSERT_JH(jh, jh->b_jlist != BJ_Shadow);
- JBUFFER_TRACE(jh, "file as data");
- __journal_file_buffer(jh, handle->h_transaction,
- BJ_SyncData);
- }
- } else {
- JBUFFER_TRACE(jh, "not on a transaction");
- __journal_file_buffer(jh, handle->h_transaction, BJ_SyncData);
- }
-no_journal:
- spin_unlock(&journal->j_list_lock);
- jbd_unlock_bh_state(bh);
- if (need_brelse) {
- BUFFER_TRACE(bh, "brelse");
- __brelse(bh);
- }
- JBUFFER_TRACE(jh, "exit");
- journal_put_journal_head(jh);
- return ret;
-}
-
-/**
- * int journal_dirty_metadata() - mark a buffer as containing dirty metadata
- * @handle: transaction to add buffer to.
- * @bh: buffer to mark
- *
- * Mark dirty metadata which needs to be journaled as part of the current
- * transaction.
- *
- * The buffer is placed on the transaction's metadata list and is marked
- * as belonging to the transaction.
- *
- * Returns error number or 0 on success.
- *
- * Special care needs to be taken if the buffer already belongs to the
- * current committing transaction (in which case we should have frozen
- * data present for that commit). In that case, we don't relink the
- * buffer: that only gets done when the old transaction finally
- * completes its commit.
- */
-int journal_dirty_metadata(handle_t *handle, struct buffer_head *bh)
-{
- transaction_t *transaction = handle->h_transaction;
- journal_t *journal = transaction->t_journal;
- struct journal_head *jh = bh2jh(bh);
-
- jbd_debug(5, "journal_head %p\n", jh);
- JBUFFER_TRACE(jh, "entry");
- if (is_handle_aborted(handle))
- goto out;
-
- jbd_lock_bh_state(bh);
-
- if (jh->b_modified == 0) {
- /*
- * This buffer's got modified and becoming part
- * of the transaction. This needs to be done
- * once a transaction -bzzz
- */
- jh->b_modified = 1;
- J_ASSERT_JH(jh, handle->h_buffer_credits > 0);
- handle->h_buffer_credits--;
- }
-
- /*
- * fastpath, to avoid expensive locking. If this buffer is already
- * on the running transaction's metadata list there is nothing to do.
- * Nobody can take it off again because there is a handle open.
- * I _think_ we're OK here with SMP barriers - a mistaken decision will
- * result in this test being false, so we go in and take the locks.
- */
- if (jh->b_transaction == transaction && jh->b_jlist == BJ_Metadata) {
- JBUFFER_TRACE(jh, "fastpath");
- J_ASSERT_JH(jh, jh->b_transaction ==
- journal->j_running_transaction);
- goto out_unlock_bh;
- }
-
- set_buffer_jbddirty(bh);
-
- /*
- * Metadata already on the current transaction list doesn't
- * need to be filed. Metadata on another transaction's list must
- * be committing, and will be refiled once the commit completes:
- * leave it alone for now.
- */
- if (jh->b_transaction != transaction) {
- JBUFFER_TRACE(jh, "already on other transaction");
- J_ASSERT_JH(jh, jh->b_transaction ==
- journal->j_committing_transaction);
- J_ASSERT_JH(jh, jh->b_next_transaction == transaction);
- /* And this case is illegal: we can't reuse another
- * transaction's data buffer, ever. */
- goto out_unlock_bh;
- }
-
- /* That test should have eliminated the following case: */
- J_ASSERT_JH(jh, jh->b_frozen_data == NULL);
-
- JBUFFER_TRACE(jh, "file as BJ_Metadata");
- spin_lock(&journal->j_list_lock);
- __journal_file_buffer(jh, handle->h_transaction, BJ_Metadata);
- spin_unlock(&journal->j_list_lock);
-out_unlock_bh:
- jbd_unlock_bh_state(bh);
-out:
- JBUFFER_TRACE(jh, "exit");
- return 0;
-}
-
-/*
- * journal_release_buffer: undo a get_write_access without any buffer
- * updates, if the update decided in the end that it didn't need access.
- *
- */
-void
-journal_release_buffer(handle_t *handle, struct buffer_head *bh)
-{
- BUFFER_TRACE(bh, "entry");
-}
-
-/**
- * void journal_forget() - bforget() for potentially-journaled buffers.
- * @handle: transaction handle
- * @bh: bh to 'forget'
- *
- * We can only do the bforget if there are no commits pending against the
- * buffer. If the buffer is dirty in the current running transaction we
- * can safely unlink it.
- *
- * bh may not be a journalled buffer at all - it may be a non-JBD
- * buffer which came off the hashtable. Check for this.
- *
- * Decrements bh->b_count by one.
- *
- * Allow this call even if the handle has aborted --- it may be part of
- * the caller's cleanup after an abort.
- */
-int journal_forget (handle_t *handle, struct buffer_head *bh)
-{
- transaction_t *transaction = handle->h_transaction;
- journal_t *journal = transaction->t_journal;
- struct journal_head *jh;
- int drop_reserve = 0;
- int err = 0;
- int was_modified = 0;
-
- BUFFER_TRACE(bh, "entry");
-
- jbd_lock_bh_state(bh);
- spin_lock(&journal->j_list_lock);
-
- if (!buffer_jbd(bh))
- goto not_jbd;
- jh = bh2jh(bh);
-
- /* Critical error: attempting to delete a bitmap buffer, maybe?
- * Don't do any jbd operations, and return an error. */
- if (!J_EXPECT_JH(jh, !jh->b_committed_data,
- "inconsistent data on disk")) {
- err = -EIO;
- goto not_jbd;
- }
-
- /* keep track of whether or not this transaction modified us */
- was_modified = jh->b_modified;
-
- /*
- * The buffer's going from the transaction, we must drop
- * all references -bzzz
- */
- jh->b_modified = 0;
-
- if (jh->b_transaction == handle->h_transaction) {
- J_ASSERT_JH(jh, !jh->b_frozen_data);
-
- /* If we are forgetting a buffer which is already part
- * of this transaction, then we can just drop it from
- * the transaction immediately. */
- clear_buffer_dirty(bh);
- clear_buffer_jbddirty(bh);
-
- JBUFFER_TRACE(jh, "belongs to current transaction: unfile");
-
- /*
- * we only want to drop a reference if this transaction
- * modified the buffer
- */
- if (was_modified)
- drop_reserve = 1;
-
- /*
- * We are no longer going to journal this buffer.
- * However, the commit of this transaction is still
- * important to the buffer: the delete that we are now
- * processing might obsolete an old log entry, so by
- * committing, we can satisfy the buffer's checkpoint.
- *
- * So, if we have a checkpoint on the buffer, we should
- * now refile the buffer on our BJ_Forget list so that
- * we know to remove the checkpoint after we commit.
- */
-
- if (jh->b_cp_transaction) {
- __journal_temp_unlink_buffer(jh);
- __journal_file_buffer(jh, transaction, BJ_Forget);
- } else {
- __journal_unfile_buffer(jh);
- if (!buffer_jbd(bh)) {
- spin_unlock(&journal->j_list_lock);
- jbd_unlock_bh_state(bh);
- __bforget(bh);
- goto drop;
- }
- }
- } else if (jh->b_transaction) {
- J_ASSERT_JH(jh, (jh->b_transaction ==
- journal->j_committing_transaction));
- /* However, if the buffer is still owned by a prior
- * (committing) transaction, we can't drop it yet... */
- JBUFFER_TRACE(jh, "belongs to older transaction");
- /* ... but we CAN drop it from the new transaction if we
- * have also modified it since the original commit. */
-
- if (jh->b_next_transaction) {
- J_ASSERT(jh->b_next_transaction == transaction);
- jh->b_next_transaction = NULL;
-
- /*
- * only drop a reference if this transaction modified
- * the buffer
- */
- if (was_modified)
- drop_reserve = 1;
- }
- }
-
-not_jbd:
- spin_unlock(&journal->j_list_lock);
- jbd_unlock_bh_state(bh);
- __brelse(bh);
-drop:
- if (drop_reserve) {
- /* no need to reserve log space for this block -bzzz */
- handle->h_buffer_credits++;
- }
- return err;
-}
-
-/**
- * int journal_stop() - complete a transaction
- * @handle: tranaction to complete.
- *
- * All done for a particular handle.
- *
- * There is not much action needed here. We just return any remaining
- * buffer credits to the transaction and remove the handle. The only
- * complication is that we need to start a commit operation if the
- * filesystem is marked for synchronous update.
- *
- * journal_stop itself will not usually return an error, but it may
- * do so in unusual circumstances. In particular, expect it to
- * return -EIO if a journal_abort has been executed since the
- * transaction began.
- */
-int journal_stop(handle_t *handle)
-{
- transaction_t *transaction = handle->h_transaction;
- journal_t *journal = transaction->t_journal;
- int err;
- pid_t pid;
-
- J_ASSERT(journal_current_handle() == handle);
-
- if (is_handle_aborted(handle))
- err = -EIO;
- else {
- J_ASSERT(transaction->t_updates > 0);
- err = 0;
- }
-
- if (--handle->h_ref > 0) {
- jbd_debug(4, "h_ref %d -> %d\n", handle->h_ref + 1,
- handle->h_ref);
- return err;
- }
-
- jbd_debug(4, "Handle %p going down\n", handle);
-
- /*
- * Implement synchronous transaction batching. If the handle
- * was synchronous, don't force a commit immediately. Let's
- * yield and let another thread piggyback onto this transaction.
- * Keep doing that while new threads continue to arrive.
- * It doesn't cost much - we're about to run a commit and sleep
- * on IO anyway. Speeds up many-threaded, many-dir operations
- * by 30x or more...
- *
- * We try and optimize the sleep time against what the underlying disk
- * can do, instead of having a static sleep time. This is useful for
- * the case where our storage is so fast that it is more optimal to go
- * ahead and force a flush and wait for the transaction to be committed
- * than it is to wait for an arbitrary amount of time for new writers to
- * join the transaction. We achieve this by measuring how long it takes
- * to commit a transaction, and compare it with how long this
- * transaction has been running, and if run time < commit time then we
- * sleep for the delta and commit. This greatly helps super fast disks
- * that would see slowdowns as more threads started doing fsyncs.
- *
- * But don't do this if this process was the most recent one to
- * perform a synchronous write. We do this to detect the case where a
- * single process is doing a stream of sync writes. No point in waiting
- * for joiners in that case.
- */
- pid = current->pid;
- if (handle->h_sync && journal->j_last_sync_writer != pid) {
- u64 commit_time, trans_time;
-
- journal->j_last_sync_writer = pid;
-
- spin_lock(&journal->j_state_lock);
- commit_time = journal->j_average_commit_time;
- spin_unlock(&journal->j_state_lock);
-
- trans_time = ktime_to_ns(ktime_sub(ktime_get(),
- transaction->t_start_time));
-
- commit_time = min_t(u64, commit_time,
- 1000*jiffies_to_usecs(1));
-
- if (trans_time < commit_time) {
- ktime_t expires = ktime_add_ns(ktime_get(),
- commit_time);
- set_current_state(TASK_UNINTERRUPTIBLE);
- schedule_hrtimeout(&expires, HRTIMER_MODE_ABS);
- }
- }
-
- current->journal_info = NULL;
- spin_lock(&journal->j_state_lock);
- spin_lock(&transaction->t_handle_lock);
- transaction->t_outstanding_credits -= handle->h_buffer_credits;
- transaction->t_updates--;
- if (!transaction->t_updates) {
- wake_up(&journal->j_wait_updates);
- if (journal->j_barrier_count)
- wake_up(&journal->j_wait_transaction_locked);
- }
-
- /*
- * If the handle is marked SYNC, we need to set another commit
- * going! We also want to force a commit if the current
- * transaction is occupying too much of the log, or if the
- * transaction is too old now.
- */
- if (handle->h_sync ||
- transaction->t_outstanding_credits >
- journal->j_max_transaction_buffers ||
- time_after_eq(jiffies, transaction->t_expires)) {
- /* Do this even for aborted journals: an abort still
- * completes the commit thread, it just doesn't write
- * anything to disk. */
- tid_t tid = transaction->t_tid;
-
- spin_unlock(&transaction->t_handle_lock);
- jbd_debug(2, "transaction too old, requesting commit for "
- "handle %p\n", handle);
- /* This is non-blocking */
- __log_start_commit(journal, transaction->t_tid);
- spin_unlock(&journal->j_state_lock);
-
- /*
- * Special case: JFS_SYNC synchronous updates require us
- * to wait for the commit to complete.
- */
- if (handle->h_sync && !(current->flags & PF_MEMALLOC))
- err = log_wait_commit(journal, tid);
- } else {
- spin_unlock(&transaction->t_handle_lock);
- spin_unlock(&journal->j_state_lock);
- }
-
- lock_map_release(&handle->h_lockdep_map);
-
- jbd_free_handle(handle);
- return err;
-}
-
-/**
- * int journal_force_commit() - force any uncommitted transactions
- * @journal: journal to force
- *
- * For synchronous operations: force any uncommitted transactions
- * to disk. May seem kludgy, but it reuses all the handle batching
- * code in a very simple manner.
- */
-int journal_force_commit(journal_t *journal)
-{
- handle_t *handle;
- int ret;
-
- handle = journal_start(journal, 1);
- if (IS_ERR(handle)) {
- ret = PTR_ERR(handle);
- } else {
- handle->h_sync = 1;
- ret = journal_stop(handle);
- }
- return ret;
-}
-
-/*
- *
- * List management code snippets: various functions for manipulating the
- * transaction buffer lists.
- *
- */
-
-/*
- * Append a buffer to a transaction list, given the transaction's list head
- * pointer.
- *
- * j_list_lock is held.
- *
- * jbd_lock_bh_state(jh2bh(jh)) is held.
- */
-
-static inline void
-__blist_add_buffer(struct journal_head **list, struct journal_head *jh)
-{
- if (!*list) {
- jh->b_tnext = jh->b_tprev = jh;
- *list = jh;
- } else {
- /* Insert at the tail of the list to preserve order */
- struct journal_head *first = *list, *last = first->b_tprev;
- jh->b_tprev = last;
- jh->b_tnext = first;
- last->b_tnext = first->b_tprev = jh;
- }
-}
-
-/*
- * Remove a buffer from a transaction list, given the transaction's list
- * head pointer.
- *
- * Called with j_list_lock held, and the journal may not be locked.
- *
- * jbd_lock_bh_state(jh2bh(jh)) is held.
- */
-
-static inline void
-__blist_del_buffer(struct journal_head **list, struct journal_head *jh)
-{
- if (*list == jh) {
- *list = jh->b_tnext;
- if (*list == jh)
- *list = NULL;
- }
- jh->b_tprev->b_tnext = jh->b_tnext;
- jh->b_tnext->b_tprev = jh->b_tprev;
-}
-
-/*
- * Remove a buffer from the appropriate transaction list.
- *
- * Note that this function can *change* the value of
- * bh->b_transaction->t_sync_datalist, t_buffers, t_forget,
- * t_iobuf_list, t_shadow_list, t_log_list or t_reserved_list. If the caller
- * is holding onto a copy of one of thee pointers, it could go bad.
- * Generally the caller needs to re-read the pointer from the transaction_t.
- *
- * Called under j_list_lock. The journal may not be locked.
- */
-static void __journal_temp_unlink_buffer(struct journal_head *jh)
-{
- struct journal_head **list = NULL;
- transaction_t *transaction;
- struct buffer_head *bh = jh2bh(jh);
-
- J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh));
- transaction = jh->b_transaction;
- if (transaction)
- assert_spin_locked(&transaction->t_journal->j_list_lock);
-
- J_ASSERT_JH(jh, jh->b_jlist < BJ_Types);
- if (jh->b_jlist != BJ_None)
- J_ASSERT_JH(jh, transaction != NULL);
-
- switch (jh->b_jlist) {
- case BJ_None:
- return;
- case BJ_SyncData:
- list = &transaction->t_sync_datalist;
- break;
- case BJ_Metadata:
- transaction->t_nr_buffers--;
- J_ASSERT_JH(jh, transaction->t_nr_buffers >= 0);
- list = &transaction->t_buffers;
- break;
- case BJ_Forget:
- list = &transaction->t_forget;
- break;
- case BJ_IO:
- list = &transaction->t_iobuf_list;
- break;
- case BJ_Shadow:
- list = &transaction->t_shadow_list;
- break;
- case BJ_LogCtl:
- list = &transaction->t_log_list;
- break;
- case BJ_Reserved:
- list = &transaction->t_reserved_list;
- break;
- case BJ_Locked:
- list = &transaction->t_locked_list;
- break;
- }
-
- __blist_del_buffer(list, jh);
- jh->b_jlist = BJ_None;
- if (test_clear_buffer_jbddirty(bh))
- mark_buffer_dirty(bh); /* Expose it to the VM */
-}
-
-/*
- * Remove buffer from all transactions.
- *
- * Called with bh_state lock and j_list_lock
- *
- * jh and bh may be already freed when this function returns.
- */
-void __journal_unfile_buffer(struct journal_head *jh)
-{
- __journal_temp_unlink_buffer(jh);
- jh->b_transaction = NULL;
- journal_put_journal_head(jh);
-}
-
-void journal_unfile_buffer(journal_t *journal, struct journal_head *jh)
-{
- struct buffer_head *bh = jh2bh(jh);
-
- /* Get reference so that buffer cannot be freed before we unlock it */
- get_bh(bh);
- jbd_lock_bh_state(bh);
- spin_lock(&journal->j_list_lock);
- __journal_unfile_buffer(jh);
- spin_unlock(&journal->j_list_lock);
- jbd_unlock_bh_state(bh);
- __brelse(bh);
-}
-
-/*
- * Called from journal_try_to_free_buffers().
- *
- * Called under jbd_lock_bh_state(bh)
- */
-static void
-__journal_try_to_free_buffer(journal_t *journal, struct buffer_head *bh)
-{
- struct journal_head *jh;
-
- jh = bh2jh(bh);
-
- if (buffer_locked(bh) || buffer_dirty(bh))
- goto out;
-
- if (jh->b_next_transaction != NULL)
- goto out;
-
- spin_lock(&journal->j_list_lock);
- if (jh->b_transaction != NULL && jh->b_cp_transaction == NULL) {
- if (jh->b_jlist == BJ_SyncData || jh->b_jlist == BJ_Locked) {
- /* A written-back ordered data buffer */
- JBUFFER_TRACE(jh, "release data");
- __journal_unfile_buffer(jh);
- }
- } else if (jh->b_cp_transaction != NULL && jh->b_transaction == NULL) {
- /* written-back checkpointed metadata buffer */
- if (jh->b_jlist == BJ_None) {
- JBUFFER_TRACE(jh, "remove from checkpoint list");
- __journal_remove_checkpoint(jh);
- }
- }
- spin_unlock(&journal->j_list_lock);
-out:
- return;
-}
-
-/**
- * int journal_try_to_free_buffers() - try to free page buffers.
- * @journal: journal for operation
- * @page: to try and free
- * @gfp_mask: we use the mask to detect how hard should we try to release
- * buffers. If __GFP_WAIT and __GFP_FS is set, we wait for commit code to
- * release the buffers.
- *
- *
- * For all the buffers on this page,
- * if they are fully written out ordered data, move them onto BUF_CLEAN
- * so try_to_free_buffers() can reap them.
- *
- * This function returns non-zero if we wish try_to_free_buffers()
- * to be called. We do this if the page is releasable by try_to_free_buffers().
- * We also do it if the page has locked or dirty buffers and the caller wants
- * us to perform sync or async writeout.
- *
- * This complicates JBD locking somewhat. We aren't protected by the
- * BKL here. We wish to remove the buffer from its committing or
- * running transaction's ->t_datalist via __journal_unfile_buffer.
- *
- * This may *change* the value of transaction_t->t_datalist, so anyone
- * who looks at t_datalist needs to lock against this function.
- *
- * Even worse, someone may be doing a journal_dirty_data on this
- * buffer. So we need to lock against that. journal_dirty_data()
- * will come out of the lock with the buffer dirty, which makes it
- * ineligible for release here.
- *
- * Who else is affected by this? hmm... Really the only contender
- * is do_get_write_access() - it could be looking at the buffer while
- * journal_try_to_free_buffer() is changing its state. But that
- * cannot happen because we never reallocate freed data as metadata
- * while the data is part of a transaction. Yes?
- *
- * Return 0 on failure, 1 on success
- */
-int journal_try_to_free_buffers(journal_t *journal,
- struct page *page, gfp_t gfp_mask)
-{
- struct buffer_head *head;
- struct buffer_head *bh;
- int ret = 0;
-
- J_ASSERT(PageLocked(page));
-
- head = page_buffers(page);
- bh = head;
- do {
- struct journal_head *jh;
-
- /*
- * We take our own ref against the journal_head here to avoid
- * having to add tons of locking around each instance of
- * journal_put_journal_head().
- */
- jh = journal_grab_journal_head(bh);
- if (!jh)
- continue;
-
- jbd_lock_bh_state(bh);
- __journal_try_to_free_buffer(journal, bh);
- journal_put_journal_head(jh);
- jbd_unlock_bh_state(bh);
- if (buffer_jbd(bh))
- goto busy;
- } while ((bh = bh->b_this_page) != head);
-
- ret = try_to_free_buffers(page);
-
-busy:
- return ret;
-}
-
-/*
- * This buffer is no longer needed. If it is on an older transaction's
- * checkpoint list we need to record it on this transaction's forget list
- * to pin this buffer (and hence its checkpointing transaction) down until
- * this transaction commits. If the buffer isn't on a checkpoint list, we
- * release it.
- * Returns non-zero if JBD no longer has an interest in the buffer.
- *
- * Called under j_list_lock.
- *
- * Called under jbd_lock_bh_state(bh).
- */
-static int __dispose_buffer(struct journal_head *jh, transaction_t *transaction)
-{
- int may_free = 1;
- struct buffer_head *bh = jh2bh(jh);
-
- if (jh->b_cp_transaction) {
- JBUFFER_TRACE(jh, "on running+cp transaction");
- __journal_temp_unlink_buffer(jh);
- /*
- * We don't want to write the buffer anymore, clear the
- * bit so that we don't confuse checks in
- * __journal_file_buffer
- */
- clear_buffer_dirty(bh);
- __journal_file_buffer(jh, transaction, BJ_Forget);
- may_free = 0;
- } else {
- JBUFFER_TRACE(jh, "on running transaction");
- __journal_unfile_buffer(jh);
- }
- return may_free;
-}
-
-/*
- * journal_invalidatepage
- *
- * This code is tricky. It has a number of cases to deal with.
- *
- * There are two invariants which this code relies on:
- *
- * i_size must be updated on disk before we start calling invalidatepage on the
- * data.
- *
- * This is done in ext3 by defining an ext3_setattr method which
- * updates i_size before truncate gets going. By maintaining this
- * invariant, we can be sure that it is safe to throw away any buffers
- * attached to the current transaction: once the transaction commits,
- * we know that the data will not be needed.
- *
- * Note however that we can *not* throw away data belonging to the
- * previous, committing transaction!
- *
- * Any disk blocks which *are* part of the previous, committing
- * transaction (and which therefore cannot be discarded immediately) are
- * not going to be reused in the new running transaction
- *
- * The bitmap committed_data images guarantee this: any block which is
- * allocated in one transaction and removed in the next will be marked
- * as in-use in the committed_data bitmap, so cannot be reused until
- * the next transaction to delete the block commits. This means that
- * leaving committing buffers dirty is quite safe: the disk blocks
- * cannot be reallocated to a different file and so buffer aliasing is
- * not possible.
- *
- *
- * The above applies mainly to ordered data mode. In writeback mode we
- * don't make guarantees about the order in which data hits disk --- in
- * particular we don't guarantee that new dirty data is flushed before
- * transaction commit --- so it is always safe just to discard data
- * immediately in that mode. --sct
- */
-
-/*
- * The journal_unmap_buffer helper function returns zero if the buffer
- * concerned remains pinned as an anonymous buffer belonging to an older
- * transaction.
- *
- * We're outside-transaction here. Either or both of j_running_transaction
- * and j_committing_transaction may be NULL.
- */
-static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh,
- int partial_page)
-{
- transaction_t *transaction;
- struct journal_head *jh;
- int may_free = 1;
-
- BUFFER_TRACE(bh, "entry");
-
-retry:
- /*
- * It is safe to proceed here without the j_list_lock because the
- * buffers cannot be stolen by try_to_free_buffers as long as we are
- * holding the page lock. --sct
- */
-
- if (!buffer_jbd(bh))
- goto zap_buffer_unlocked;
-
- spin_lock(&journal->j_state_lock);
- jbd_lock_bh_state(bh);
- spin_lock(&journal->j_list_lock);
-
- jh = journal_grab_journal_head(bh);
- if (!jh)
- goto zap_buffer_no_jh;
-
- /*
- * We cannot remove the buffer from checkpoint lists until the
- * transaction adding inode to orphan list (let's call it T)
- * is committed. Otherwise if the transaction changing the
- * buffer would be cleaned from the journal before T is
- * committed, a crash will cause that the correct contents of
- * the buffer will be lost. On the other hand we have to
- * clear the buffer dirty bit at latest at the moment when the
- * transaction marking the buffer as freed in the filesystem
- * structures is committed because from that moment on the
- * block can be reallocated and used by a different page.
- * Since the block hasn't been freed yet but the inode has
- * already been added to orphan list, it is safe for us to add
- * the buffer to BJ_Forget list of the newest transaction.
- *
- * Also we have to clear buffer_mapped flag of a truncated buffer
- * because the buffer_head may be attached to the page straddling
- * i_size (can happen only when blocksize < pagesize) and thus the
- * buffer_head can be reused when the file is extended again. So we end
- * up keeping around invalidated buffers attached to transactions'
- * BJ_Forget list just to stop checkpointing code from cleaning up
- * the transaction this buffer was modified in.
- */
- transaction = jh->b_transaction;
- if (transaction == NULL) {
- /* First case: not on any transaction. If it
- * has no checkpoint link, then we can zap it:
- * it's a writeback-mode buffer so we don't care
- * if it hits disk safely. */
- if (!jh->b_cp_transaction) {
- JBUFFER_TRACE(jh, "not on any transaction: zap");
- goto zap_buffer;
- }
-
- if (!buffer_dirty(bh)) {
- /* bdflush has written it. We can drop it now */
- goto zap_buffer;
- }
-
- /* OK, it must be in the journal but still not
- * written fully to disk: it's metadata or
- * journaled data... */
-
- if (journal->j_running_transaction) {
- /* ... and once the current transaction has
- * committed, the buffer won't be needed any
- * longer. */
- JBUFFER_TRACE(jh, "checkpointed: add to BJ_Forget");
- may_free = __dispose_buffer(jh,
- journal->j_running_transaction);
- goto zap_buffer;
- } else {
- /* There is no currently-running transaction. So the
- * orphan record which we wrote for this file must have
- * passed into commit. We must attach this buffer to
- * the committing transaction, if it exists. */
- if (journal->j_committing_transaction) {
- JBUFFER_TRACE(jh, "give to committing trans");
- may_free = __dispose_buffer(jh,
- journal->j_committing_transaction);
- goto zap_buffer;
- } else {
- /* The orphan record's transaction has
- * committed. We can cleanse this buffer */
- clear_buffer_jbddirty(bh);
- goto zap_buffer;
- }
- }
- } else if (transaction == journal->j_committing_transaction) {
- JBUFFER_TRACE(jh, "on committing transaction");
- if (jh->b_jlist == BJ_Locked) {
- /*
- * The buffer is on the committing transaction's locked
- * list. We have the buffer locked, so I/O has
- * completed. So we can nail the buffer now.
- */
- may_free = __dispose_buffer(jh, transaction);
- goto zap_buffer;
- }
- /*
- * The buffer is committing, we simply cannot touch
- * it. If the page is straddling i_size we have to wait
- * for commit and try again.
- */
- if (partial_page) {
- tid_t tid = journal->j_committing_transaction->t_tid;
-
- journal_put_journal_head(jh);
- spin_unlock(&journal->j_list_lock);
- jbd_unlock_bh_state(bh);
- spin_unlock(&journal->j_state_lock);
- unlock_buffer(bh);
- log_wait_commit(journal, tid);
- lock_buffer(bh);
- goto retry;
- }
- /*
- * OK, buffer won't be reachable after truncate. We just set
- * j_next_transaction to the running transaction (if there is
- * one) and mark buffer as freed so that commit code knows it
- * should clear dirty bits when it is done with the buffer.
- */
- set_buffer_freed(bh);
- if (journal->j_running_transaction && buffer_jbddirty(bh))
- jh->b_next_transaction = journal->j_running_transaction;
- journal_put_journal_head(jh);
- spin_unlock(&journal->j_list_lock);
- jbd_unlock_bh_state(bh);
- spin_unlock(&journal->j_state_lock);
- return 0;
- } else {
- /* Good, the buffer belongs to the running transaction.
- * We are writing our own transaction's data, not any
- * previous one's, so it is safe to throw it away
- * (remember that we expect the filesystem to have set
- * i_size already for this truncate so recovery will not
- * expose the disk blocks we are discarding here.) */
- J_ASSERT_JH(jh, transaction == journal->j_running_transaction);
- JBUFFER_TRACE(jh, "on running transaction");
- may_free = __dispose_buffer(jh, transaction);
- }
-
-zap_buffer:
- /*
- * This is tricky. Although the buffer is truncated, it may be reused
- * if blocksize < pagesize and it is attached to the page straddling
- * EOF. Since the buffer might have been added to BJ_Forget list of the
- * running transaction, journal_get_write_access() won't clear
- * b_modified and credit accounting gets confused. So clear b_modified
- * here. */
- jh->b_modified = 0;
- journal_put_journal_head(jh);
-zap_buffer_no_jh:
- spin_unlock(&journal->j_list_lock);
- jbd_unlock_bh_state(bh);
- spin_unlock(&journal->j_state_lock);
-zap_buffer_unlocked:
- clear_buffer_dirty(bh);
- J_ASSERT_BH(bh, !buffer_jbddirty(bh));
- clear_buffer_mapped(bh);
- clear_buffer_req(bh);
- clear_buffer_new(bh);
- bh->b_bdev = NULL;
- return may_free;
-}
-
-/**
- * void journal_invalidatepage() - invalidate a journal page
- * @journal: journal to use for flush
- * @page: page to flush
- * @offset: offset of the range to invalidate
- * @length: length of the range to invalidate
- *
- * Reap page buffers containing data in specified range in page.
- */
-void journal_invalidatepage(journal_t *journal,
- struct page *page,
- unsigned int offset,
- unsigned int length)
-{
- struct buffer_head *head, *bh, *next;
- unsigned int stop = offset + length;
- unsigned int curr_off = 0;
- int partial_page = (offset || length < PAGE_CACHE_SIZE);
- int may_free = 1;
-
- if (!PageLocked(page))
- BUG();
- if (!page_has_buffers(page))
- return;
-
- BUG_ON(stop > PAGE_CACHE_SIZE || stop < length);
-
- /* We will potentially be playing with lists other than just the
- * data lists (especially for journaled data mode), so be
- * cautious in our locking. */
-
- head = bh = page_buffers(page);
- do {
- unsigned int next_off = curr_off + bh->b_size;
- next = bh->b_this_page;
-
- if (next_off > stop)
- return;
-
- if (offset <= curr_off) {
- /* This block is wholly outside the truncation point */
- lock_buffer(bh);
- may_free &= journal_unmap_buffer(journal, bh,
- partial_page);
- unlock_buffer(bh);
- }
- curr_off = next_off;
- bh = next;
-
- } while (bh != head);
-
- if (!partial_page) {
- if (may_free && try_to_free_buffers(page))
- J_ASSERT(!page_has_buffers(page));
- }
-}
-
-/*
- * File a buffer on the given transaction list.
- */
-void __journal_file_buffer(struct journal_head *jh,
- transaction_t *transaction, int jlist)
-{
- struct journal_head **list = NULL;
- int was_dirty = 0;
- struct buffer_head *bh = jh2bh(jh);
-
- J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh));
- assert_spin_locked(&transaction->t_journal->j_list_lock);
-
- J_ASSERT_JH(jh, jh->b_jlist < BJ_Types);
- J_ASSERT_JH(jh, jh->b_transaction == transaction ||
- jh->b_transaction == NULL);
-
- if (jh->b_transaction && jh->b_jlist == jlist)
- return;
-
- if (jlist == BJ_Metadata || jlist == BJ_Reserved ||
- jlist == BJ_Shadow || jlist == BJ_Forget) {
- /*
- * For metadata buffers, we track dirty bit in buffer_jbddirty
- * instead of buffer_dirty. We should not see a dirty bit set
- * here because we clear it in do_get_write_access but e.g.
- * tune2fs can modify the sb and set the dirty bit at any time
- * so we try to gracefully handle that.
- */
- if (buffer_dirty(bh))
- warn_dirty_buffer(bh);
- if (test_clear_buffer_dirty(bh) ||
- test_clear_buffer_jbddirty(bh))
- was_dirty = 1;
- }
-
- if (jh->b_transaction)
- __journal_temp_unlink_buffer(jh);
- else
- journal_grab_journal_head(bh);
- jh->b_transaction = transaction;
-
- switch (jlist) {
- case BJ_None:
- J_ASSERT_JH(jh, !jh->b_committed_data);
- J_ASSERT_JH(jh, !jh->b_frozen_data);
- return;
- case BJ_SyncData:
- list = &transaction->t_sync_datalist;
- break;
- case BJ_Metadata:
- transaction->t_nr_buffers++;
- list = &transaction->t_buffers;
- break;
- case BJ_Forget:
- list = &transaction->t_forget;
- break;
- case BJ_IO:
- list = &transaction->t_iobuf_list;
- break;
- case BJ_Shadow:
- list = &transaction->t_shadow_list;
- break;
- case BJ_LogCtl:
- list = &transaction->t_log_list;
- break;
- case BJ_Reserved:
- list = &transaction->t_reserved_list;
- break;
- case BJ_Locked:
- list = &transaction->t_locked_list;
- break;
- }
-
- __blist_add_buffer(list, jh);
- jh->b_jlist = jlist;
-
- if (was_dirty)
- set_buffer_jbddirty(bh);
-}
-
-void journal_file_buffer(struct journal_head *jh,
- transaction_t *transaction, int jlist)
-{
- jbd_lock_bh_state(jh2bh(jh));
- spin_lock(&transaction->t_journal->j_list_lock);
- __journal_file_buffer(jh, transaction, jlist);
- spin_unlock(&transaction->t_journal->j_list_lock);
- jbd_unlock_bh_state(jh2bh(jh));
-}
-
-/*
- * Remove a buffer from its current buffer list in preparation for
- * dropping it from its current transaction entirely. If the buffer has
- * already started to be used by a subsequent transaction, refile the
- * buffer on that transaction's metadata list.
- *
- * Called under j_list_lock
- * Called under jbd_lock_bh_state(jh2bh(jh))
- *
- * jh and bh may be already free when this function returns
- */
-void __journal_refile_buffer(struct journal_head *jh)
-{
- int was_dirty, jlist;
- struct buffer_head *bh = jh2bh(jh);
-
- J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh));
- if (jh->b_transaction)
- assert_spin_locked(&jh->b_transaction->t_journal->j_list_lock);
-
- /* If the buffer is now unused, just drop it. */
- if (jh->b_next_transaction == NULL) {
- __journal_unfile_buffer(jh);
- return;
- }
-
- /*
- * It has been modified by a later transaction: add it to the new
- * transaction's metadata list.
- */
-
- was_dirty = test_clear_buffer_jbddirty(bh);
- __journal_temp_unlink_buffer(jh);
- /*
- * We set b_transaction here because b_next_transaction will inherit
- * our jh reference and thus __journal_file_buffer() must not take a
- * new one.
- */
- jh->b_transaction = jh->b_next_transaction;
- jh->b_next_transaction = NULL;
- if (buffer_freed(bh))
- jlist = BJ_Forget;
- else if (jh->b_modified)
- jlist = BJ_Metadata;
- else
- jlist = BJ_Reserved;
- __journal_file_buffer(jh, jh->b_transaction, jlist);
- J_ASSERT_JH(jh, jh->b_transaction->t_state == T_RUNNING);
-
- if (was_dirty)
- set_buffer_jbddirty(bh);
-}
-
-/*
- * __journal_refile_buffer() with necessary locking added. We take our bh
- * reference so that we can safely unlock bh.
- *
- * The jh and bh may be freed by this call.
- */
-void journal_refile_buffer(journal_t *journal, struct journal_head *jh)
-{
- struct buffer_head *bh = jh2bh(jh);
-
- /* Get reference so that buffer cannot be freed before we unlock it */
- get_bh(bh);
- jbd_lock_bh_state(bh);
- spin_lock(&journal->j_list_lock);
- __journal_refile_buffer(jh);
- jbd_unlock_bh_state(bh);
- spin_unlock(&journal->j_list_lock);
- __brelse(bh);
-}