void journal_unfile_buffer(struct buffer_head *buf)
{
struct buffer_head **list = 0;
transaction_t * transaction;
transaction = buf->b_transaction;
#ifdef __SMP__
J_ASSERT (current->lock_depth >= 0);
#endif
J_ASSERT (transaction->t_journal->j_locked);
J_ASSERT (buf->b_jlist < BJ_Types);
if (buf->b_jlist != BJ_None)
J_ASSERT (transaction != 0);
switch (buf->b_jlist) {
case BJ_None:
return;
case BJ_Data:
list = &transaction->t_datalist;
break;
case BJ_Metadata:
transaction->t_nr_buffers--;
J_ASSERT(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;
}
blist_del_buffer(list, buf);
buf->b_jlist = BJ_None;
if (buffer_jdirty(buf)) {
set_bit(BH_Dirty, &buf->b_state);
clear_bit(BH_JDirty, &buf->b_state);
}
}
void journal_release_buffer (handle_t *handle, struct buffer_head *bh)
{
transaction_t *transaction = handle->h_transaction;
journal_t *journal = transaction->t_journal;
lock_journal(journal);
/* If the buffer is reserved but not modified by this
* transaction, then it is safe to release it. In all other
* cases, just leave the buffer as it is. */
if (bh->b_jlist == BJ_Reserved && bh->b_transaction == transaction &&
!buffer_jdirty(bh)) {
handle->h_buffer_credits++;
journal_refile_buffer(bh);
}
unlock_journal(journal);
}
/*
* 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 journal_datalist_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_jdirty(jh2bh(jh)));
J_ASSERT_JH(jh, jh->b_cp_transaction == NULL);
assert_spin_locked(&journal_datalist_lock);
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;
}
/*
* 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;
}