diff options
Diffstat (limited to 'fs/jbd2/transaction.c')
| -rw-r--r-- | fs/jbd2/transaction.c | 83 |
1 files changed, 61 insertions, 22 deletions
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c index cc35537232f2..f940d31c2adc 100644 --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -63,7 +63,7 @@ void jbd2_journal_free_transaction(transaction_t *transaction) /* * jbd2_get_transaction: obtain a new transaction_t object. * - * Simply allocate and initialise a new transaction. Create it in + * Simply initialise a new transaction. Initialize 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). @@ -75,8 +75,8 @@ void jbd2_journal_free_transaction(transaction_t *transaction) * */ -static transaction_t * -jbd2_get_transaction(journal_t *journal, transaction_t *transaction) +static void jbd2_get_transaction(journal_t *journal, + transaction_t *transaction) { transaction->t_journal = journal; transaction->t_state = T_RUNNING; @@ -100,8 +100,6 @@ jbd2_get_transaction(journal_t *journal, transaction_t *transaction) transaction->t_max_wait = 0; transaction->t_start = jiffies; transaction->t_requested = 0; - - return transaction; } /* @@ -1252,11 +1250,12 @@ int jbd2_journal_get_undo_access(handle_t *handle, struct buffer_head *bh) struct journal_head *jh; char *committed_data = NULL; - JBUFFER_TRACE(jh, "entry"); if (jbd2_write_access_granted(handle, bh, true)) return 0; jh = jbd2_journal_add_journal_head(bh); + 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 @@ -1367,15 +1366,17 @@ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh) if (is_handle_aborted(handle)) return -EROFS; - if (!buffer_jbd(bh)) { - ret = -EUCLEAN; - goto out; - } + if (!buffer_jbd(bh)) + return -EUCLEAN; + /* * We don't grab jh reference here since the buffer must be part * of the running transaction. */ jh = bh2jh(bh); + jbd_debug(5, "journal_head %p\n", jh); + JBUFFER_TRACE(jh, "entry"); + /* * This and the following assertions are unreliable since we may see jh * in inconsistent state unless we grab bh_state lock. But this is @@ -1409,9 +1410,6 @@ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh) } journal = transaction->t_journal; - jbd_debug(5, "journal_head %p\n", jh); - JBUFFER_TRACE(jh, "entry"); - jbd_lock_bh_state(bh); if (jh->b_modified == 0) { @@ -1597,9 +1595,7 @@ int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh) __jbd2_journal_unfile_buffer(jh); if (!buffer_jbd(bh)) { spin_unlock(&journal->j_list_lock); - jbd_unlock_bh_state(bh); - __bforget(bh); - goto drop; + goto not_jbd; } } spin_unlock(&journal->j_list_lock); @@ -1609,14 +1605,21 @@ int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh) /* 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. */ + /* ... but we CAN drop it from the new transaction through + * marking the buffer as freed and set j_next_transaction to + * the new transaction, so that not only the commit code + * knows it should clear dirty bits when it is done with the + * buffer, but also the buffer can be checkpointed only + * after the new transaction commits. */ - if (jh->b_next_transaction) { - J_ASSERT(jh->b_next_transaction == transaction); + set_buffer_freed(bh); + + if (!jh->b_next_transaction) { spin_lock(&journal->j_list_lock); - jh->b_next_transaction = NULL; + jh->b_next_transaction = transaction; spin_unlock(&journal->j_list_lock); + } else { + J_ASSERT(jh->b_next_transaction == transaction); /* * only drop a reference if this transaction modified @@ -1625,9 +1628,40 @@ int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh) if (was_modified) drop_reserve = 1; } + } else { + /* + * Finally, if the buffer is not belongs to any + * transaction, we can just drop it now if it has no + * checkpoint. + */ + spin_lock(&journal->j_list_lock); + if (!jh->b_cp_transaction) { + JBUFFER_TRACE(jh, "belongs to none transaction"); + spin_unlock(&journal->j_list_lock); + goto not_jbd; + } + + /* + * Otherwise, if the buffer has been written to disk, + * it is safe to remove the checkpoint and drop it. + */ + if (!buffer_dirty(bh)) { + __jbd2_journal_remove_checkpoint(jh); + spin_unlock(&journal->j_list_lock); + goto not_jbd; + } + + /* + * The buffer is still not written to disk, we should + * attach this buffer to current transaction so that the + * buffer can be checkpointed only after the current + * transaction commits. + */ + clear_buffer_dirty(bh); + __jbd2_journal_file_buffer(jh, transaction, BJ_Forget); + spin_unlock(&journal->j_list_lock); } -not_jbd: jbd_unlock_bh_state(bh); __brelse(bh); drop: @@ -1636,6 +1670,11 @@ drop: handle->h_buffer_credits++; } return err; + +not_jbd: + jbd_unlock_bh_state(bh); + __bforget(bh); + goto drop; } /** |