void journal_sync_buffer(struct buffer_head *bh)
{
transaction_t *transaction;
journal_t *journal;
long sequence;
/* If the buffer isn't journaled, this is easy: just sync it to
* disk. */
if (bh->b_transaction == NULL) {
/* If the buffer has already been journaled, then this
* is a noop. */
if (bh->b_cp_transaction == NULL)
return;
ll_rw_block (WRITE, 1, &bh);
wait_on_buffer (bh);
return;
}
/* Otherwise, just wait until the transaction is synced to disk. */
transaction = bh->b_transaction;
journal = transaction->t_journal;
sequence = transaction->t_tid;
jfs_debug(2, "requesting commit for bh %p\n", bh);
log_start_commit (journal, transaction);
while (tid_gt(sequence, journal->j_commit_sequence)) {
wake_up(&journal->j_wait_done_commit);
sleep_on(&journal->j_wait_done_commit);
}
}
int ext3_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
{
struct inode *inode = file->f_mapping->host;
struct ext3_inode_info *ei = EXT3_I(inode);
journal_t *journal = EXT3_SB(inode->i_sb)->s_journal;
int ret, needs_barrier = 0;
tid_t commit_tid;
trace_ext3_sync_file_enter(file, datasync);
if (inode->i_sb->s_flags & MS_RDONLY)
return 0;
ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
if (ret)
goto out;
J_ASSERT(ext3_journal_current_handle() == NULL);
/*
* data=writeback,ordered:
* The caller's filemap_fdatawrite()/wait will sync the data.
* Metadata is in the journal, we wait for a proper transaction
* to commit here.
*
* data=journal:
* filemap_fdatawrite won't do anything (the buffers are clean).
* ext3_force_commit will write the file data into the journal and
* will wait on that.
* filemap_fdatawait() will encounter a ton of newly-dirtied pages
* (they were dirtied by commit). But that's OK - the blocks are
* safe in-journal, which is all fsync() needs to ensure.
*/
if (ext3_should_journal_data(inode)) {
ret = ext3_force_commit(inode->i_sb);
goto out;
}
if (datasync)
commit_tid = atomic_read(&ei->i_datasync_tid);
else
commit_tid = atomic_read(&ei->i_sync_tid);
if (test_opt(inode->i_sb, BARRIER) &&
!journal_trans_will_send_data_barrier(journal, commit_tid))
needs_barrier = 1;
log_start_commit(journal, commit_tid);
ret = log_wait_commit(journal, commit_tid);
/*
* In case we didn't commit a transaction, we have to flush
* disk caches manually so that data really is on persistent
* storage
*/
if (needs_barrier)
blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
out:
trace_ext3_sync_file_exit(inode, ret);
return ret;
}
static int mlowerfs_ext3_commit_async(struct inode *inode, void *h,
void **wait_handle)
{
unsigned long tid = 0;
transaction_t *transaction = NULL;
handle_t *handle = h;
journal_t *journal = NULL;
int ret = 0;
MENTRY();
MASSERT(current->journal_info == handle);
transaction = handle->h_transaction;
journal = transaction->t_journal;
tid = transaction->t_tid;
/* we don't want to be blocked */
handle->h_sync = 0;
ret = _mlowerfs_ext3_journal_stop(handle);
if (ret) {
MERROR("error while stopping transaction: %d\n", ret);
goto out;
}
log_start_commit(journal, tid);
*wait_handle = (void *) tid;
out:
MRETURN(ret);
}
/*
* 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.
*
* 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)) {
atomic_inc(&bh->b_count);
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)) {
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);
journal_remove_journal_head(bh);
__brelse(bh);
ret = 1;
} 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;
}
int journal_stop (handle_t *handle)
{
transaction_t *transaction = handle->h_transaction;
journal_t *journal = transaction->t_journal;
int force_sync;
if (!handle)
return 0;
J_ASSERT (transaction->t_updates > 0);
J_ASSERT (current->j_handle == handle);
if (--handle->h_ref > 0)
return 0;
jfs_debug(4, "Handle %p going down\n", handle);
current->j_handle = NULL;
// current->fs_locks--;
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 journal 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.
*/
force_sync = (journal->j_flags & JFS_SYNC) || handle->h_sync;
if (force_sync ||
transaction->t_outstanding_credits > journal->j_max_transaction_buffers ||
time_after_eq(jiffies, transaction->t_expires)) {
tid_t tid = transaction->t_tid;
jfs_debug(2, "transaction too old, requesting commit for handle %p\n", handle);
log_start_commit(journal, transaction);
/*
* Special case: JFS_SYNC synchronous updates require us
* to wait for the commit to complete.
*/
if (force_sync)
log_wait_commit(journal, tid);
}
kfree(handle);
return 0;
}
int ext3_sync_file(struct file * file, struct dentry *dentry, int datasync)
{
struct inode *inode = dentry->d_inode;
struct ext3_inode_info *ei = EXT3_I(inode);
journal_t *journal = EXT3_SB(inode->i_sb)->s_journal;
int ret = 0;
tid_t commit_tid;
if (inode->i_sb->s_flags & MS_RDONLY)
return 0;
J_ASSERT(ext3_journal_current_handle() == NULL);
/*
* data=writeback,ordered:
* The caller's filemap_fdatawrite()/wait will sync the data.
* Metadata is in the journal, we wait for a proper transaction
* to commit here.
*
* data=journal:
* filemap_fdatawrite won't do anything (the buffers are clean).
* ext3_force_commit will write the file data into the journal and
* will wait on that.
* filemap_fdatawait() will encounter a ton of newly-dirtied pages
* (they were dirtied by commit). But that's OK - the blocks are
* safe in-journal, which is all fsync() needs to ensure.
*/
if (ext3_should_journal_data(inode)) {
ret = ext3_force_commit(inode->i_sb);
goto out;
}
if (datasync)
commit_tid = atomic_read(&ei->i_datasync_tid);
else
commit_tid = atomic_read(&ei->i_sync_tid);
if (log_start_commit(journal, commit_tid)) {
log_wait_commit(journal, commit_tid);
goto out;
}
/*
* In case we didn't commit a transaction, we have to flush
* disk caches manually so that data really is on persistent
* storage
*/
if (test_opt(inode->i_sb, BARRIER))
blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL,
BLKDEV_IFL_WAIT);
out:
return ret;
}
int journal_restart(handle_t *handle, int nblocks)
{
transaction_t *transaction = handle->h_transaction;
journal_t *journal = transaction->t_journal;
/* First unlink the handle from its current transaction, and
* start the commit on that. */
J_ASSERT (transaction->t_updates > 0);
J_ASSERT (current->j_handle == handle);
transaction->t_outstanding_credits -= handle->h_buffer_credits;
transaction->t_updates--;
if (!transaction->t_updates)
wake_up(&journal->j_wait_updates);
jfs_debug(2, "restarting handle %p\n", handle);
log_start_commit(journal, transaction);
handle->h_buffer_credits = nblocks;
return start_this_handle(journal, handle);
}
static int start_this_handle(journal_t *journal, handle_t *handle)
{
transaction_t *transaction;
int needed;
int nblocks = handle->h_buffer_credits;
jfs_debug(4, "New handle %p going live.\n", handle);
repeat:
lock_journal(journal);
if ((journal->j_flags & JFS_ABORT) ||
(journal->j_errno != 0 && !(journal->j_flags & JFS_ACK_ERR))) {
unlock_journal(journal);
return -EROFS;
}
/* Wait on the journal's transaction barrier if necessary */
if (journal->j_barrier_count) {
unlock_journal(journal);
sleep_on(&journal->j_wait_transaction_locked);
goto repeat;
}
repeat_locked:
if (!journal->j_running_transaction)
get_transaction(journal);
/* @@@ Error? */
J_ASSERT(journal->j_running_transaction);
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) {
unlock_journal(journal);
jfs_debug(3, "Handle %p stalling...\n", handle);
sleep_on(&journal->j_wait_transaction_locked);
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. */
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. */
jfs_debug(2, "Handle %p starting new commit...\n", handle);
log_start_commit(journal, transaction);
unlock_journal(journal);
sleep_on(&journal->j_wait_transaction_locked);
lock_journal(journal);
goto repeat_locked;
}
/*
* 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.
*/
needed = journal->j_max_transaction_buffers;
if (journal->j_committing_transaction)
needed += journal->j_committing_transaction->t_outstanding_credits;
if (log_space_left(journal) < needed) {
jfs_debug(2, "Handle %p waiting for checkpoint...\n", handle);
log_wait_for_space(journal, needed);
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++;
jfs_debug(4, "Handle %p given %d credits (total %d, free %d)\n",
handle, nblocks, transaction->t_outstanding_credits,
log_space_left(journal));
unlock_journal(journal);
return 0;
}
/*
* Called at inode eviction from icache
*/
void ext3_evict_inode (struct inode *inode)
{
struct ext3_inode_info *ei = EXT3_I(inode);
struct ext3_block_alloc_info *rsv;
handle_t *handle;
int want_delete = 0;
trace_ext3_evict_inode(inode);
if (!inode->i_nlink && !is_bad_inode(inode)) {
dquot_initialize(inode);
want_delete = 1;
}
/*
* When journalling data dirty buffers are tracked only in the journal.
* So although mm thinks everything is clean and ready for reaping the
* inode might still have some pages to write in the running
* transaction or waiting to be checkpointed. Thus calling
* journal_invalidatepage() (via truncate_inode_pages()) to discard
* these buffers can cause data loss. Also even if we did not discard
* these buffers, we would have no way to find them after the inode
* is reaped and thus user could see stale data if he tries to read
* them before the transaction is checkpointed. So be careful and
* force everything to disk here... We use ei->i_datasync_tid to
* store the newest transaction containing inode's data.
*
* Note that directories do not have this problem because they don't
* use page cache.
*
* The s_journal check handles the case when ext3_get_journal() fails
* and puts the journal inode.
*/
if (inode->i_nlink && ext3_should_journal_data(inode) &&
EXT3_SB(inode->i_sb)->s_journal &&
(S_ISLNK(inode->i_mode) || S_ISREG(inode->i_mode)) &&
inode->i_ino != EXT3_JOURNAL_INO) {
tid_t commit_tid = atomic_read(&ei->i_datasync_tid);
journal_t *journal = EXT3_SB(inode->i_sb)->s_journal;
log_start_commit(journal, commit_tid);
log_wait_commit(journal, commit_tid);
filemap_write_and_wait(&inode->i_data);
}
truncate_inode_pages(&inode->i_data, 0);
ext3_discard_reservation(inode);
rsv = ei->i_block_alloc_info;
ei->i_block_alloc_info = NULL;
if (unlikely(rsv))
kfree(rsv);
if (!want_delete)
goto no_delete;
handle = start_transaction(inode);
if (IS_ERR(handle)) {
/*
* If we're going to skip the normal cleanup, we still need to
* make sure that the in-core orphan linked list is properly
* cleaned up.
*/
ext3_orphan_del(NULL, inode);
goto no_delete;
}
if (IS_SYNC(inode))
handle->h_sync = 1;
inode->i_size = 0;
if (inode->i_blocks)
ext3_truncate(inode);
/*
* Kill off the orphan record created when the inode lost the last
* link. Note that ext3_orphan_del() has to be able to cope with the
* deletion of a non-existent orphan - ext3_truncate() could
* have removed the record.
*/
ext3_orphan_del(handle, inode);
ei->i_dtime = get_seconds();
/*
* One subtle ordering requirement: if anything has gone wrong
* (transaction abort, IO errors, whatever), then we can still
* do these next steps (the fs will already have been marked as
* having errors), but we can't free the inode if the mark_dirty
* fails.
*/
if (ext3_mark_inode_dirty(handle, inode)) {
/* If that failed, just dquot_drop() and be done with that */
dquot_drop(inode);
clear_inode(inode);
} else {
ext3_xattr_delete_inode(handle, inode);
dquot_free_inode(inode);
dquot_drop(inode);
clear_inode(inode);
ext3_free_inode(handle, inode);
}
ext3_journal_stop(handle);
return;
no_delete:
clear_inode(inode);
dquot_drop(inode);
}
/*
* Clean up a transaction's checkpoint list.
*
* We wait for any pending IO to complete and make sure any clean
* buffers are removed from the transaction.
*
* Return 1 if we performed any actions which might have destroyed the
* checkpoint. (journal_remove_checkpoint() deletes the transaction when
* the last checkpoint buffer is cleansed)
*
* Called with the journal locked.
* Called with journal_datalist_lock held.
*/
static int __cleanup_transaction(journal_t *journal, transaction_t *transaction)
{
struct journal_head *jh, *next_jh, *last_jh;
struct buffer_head *bh;
int ret = 0;
assert_spin_locked(&journal_datalist_lock);
jh = transaction->t_checkpoint_list;
if (!jh)
return 0;
last_jh = jh->b_cpprev;
next_jh = jh;
do {
jh = next_jh;
bh = jh2bh(jh);
if (buffer_locked(bh)) {
atomic_inc(&bh->b_count);
spin_unlock(&journal_datalist_lock);
unlock_journal(journal);
wait_on_buffer(bh);
/* the journal_head may have gone by now */
BUFFER_TRACE(bh, "brelse");
__brelse(bh);
goto out_return_1;
}
if (jh->b_transaction != NULL) {
transaction_t *transaction = jh->b_transaction;
tid_t tid = transaction->t_tid;
spin_unlock(&journal_datalist_lock);
log_start_commit(journal, transaction);
unlock_journal(journal);
log_wait_commit(journal, tid);
goto out_return_1;
}
/*
* We used to test for (jh->b_list != BUF_CLEAN) here.
* But unmap_underlying_metadata() can place buffer onto
* BUF_CLEAN. Since refile_buffer() no longer takes buffers
* off checkpoint lists, we cope with it here
*/
/*
* AKPM: I think the buffer_jdirty test is redundant - it
* shouldn't have NULL b_transaction?
*/
next_jh = jh->b_cpnext;
if (!buffer_dirty(bh) && !buffer_jdirty(bh)) {
BUFFER_TRACE(bh, "remove from checkpoint");
__journal_remove_checkpoint(jh);
__journal_remove_journal_head(bh);
refile_buffer(bh);
__brelse(bh);
ret = 1;
}
jh = next_jh;
} while (jh != last_jh);
return ret;
out_return_1:
lock_journal(journal);
spin_lock(&journal_datalist_lock);
return 1;
}
/*
* Clean up a transaction's checkpoint list.
*
* We wait for any pending IO to complete and make sure any clean
* buffers are removed from the transaction.
*
* Return 1 if we performed any actions which might have destroyed the
* checkpoint. (journal_remove_checkpoint() deletes the transaction when
* the last checkpoint buffer is cleansed)
*
* Called with j_list_lock held.
*/
static int __cleanup_transaction(journal_t *journal, transaction_t *transaction)
{
struct journal_head *jh, *next_jh, *last_jh;
struct buffer_head *bh;
int ret = 0;
assert_spin_locked(&journal->j_list_lock);
jh = transaction->t_checkpoint_list;
if (!jh)
return 0;
last_jh = jh->b_cpprev;
next_jh = jh;
do {
jh = next_jh;
bh = jh2bh(jh);
if (buffer_locked(bh)) {
atomic_inc(&bh->b_count);
spin_unlock(&journal->j_list_lock);
wait_on_buffer(bh);
/* the journal_head may have gone by now */
BUFFER_TRACE(bh, "brelse");
__brelse(bh);
goto out_return_1;
}
/*
* This is foul
*/
if (!jbd_trylock_bh_state(bh)) {
jbd_sync_bh(journal, bh);
goto out_return_1;
}
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);
goto out_return_1;
}
/*
* AKPM: I think the buffer_jbddirty test is redundant - it
* shouldn't have NULL b_transaction?
*/
next_jh = jh->b_cpnext;
if (!buffer_dirty(bh) && !buffer_jbddirty(bh)) {
BUFFER_TRACE(bh, "remove from checkpoint");
__journal_remove_checkpoint(jh);
jbd_unlock_bh_state(bh);
journal_remove_journal_head(bh);
__brelse(bh);
ret = 1;
} else {
jbd_unlock_bh_state(bh);
}
} while (jh != last_jh);
return ret;
out_return_1:
spin_lock(&journal->j_list_lock);
return 1;
}