+
+/*
+ * File inode in the inode list of the handle's transaction
+ */
+int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *jinode)
+{
+ transaction_t *transaction = handle->h_transaction;
+ journal_t *journal = transaction->t_journal;
+
+ if (is_handle_aborted(handle))
+ return -EIO;
+
+ jbd_debug(4, "Adding inode %lu, tid:%d\n", jinode->i_vfs_inode->i_ino,
+ transaction->t_tid);
+
+ /*
+ * First check whether inode isn't already on the transaction's
+ * lists without taking the lock. Note that this check is safe
+ * without the lock as we cannot race with somebody removing inode
+ * from the transaction. The reason is that we remove inode from the
+ * transaction only in journal_release_jbd_inode() and when we commit
+ * the transaction. We are guarded from the first case by holding
+ * a reference to the inode. We are safe against the second case
+ * because if jinode->i_transaction == transaction, commit code
+ * cannot touch the transaction because we hold reference to it,
+ * and if jinode->i_next_transaction == transaction, commit code
+ * will only file the inode where we want it.
+ */
+ if (jinode->i_transaction == transaction ||
+ jinode->i_next_transaction == transaction)
+ return 0;
+
+ spin_lock(&journal->j_list_lock);
+
+ if (jinode->i_transaction == transaction ||
+ jinode->i_next_transaction == transaction)
+ goto done;
+
+ /* On some different transaction's list - should be
+ * the committing one */
+ if (jinode->i_transaction) {
+ J_ASSERT(jinode->i_next_transaction == NULL);
+ J_ASSERT(jinode->i_transaction ==
+ journal->j_committing_transaction);
+ jinode->i_next_transaction = transaction;
+ goto done;
+ }
+ /* Not on any transaction list... */
+ J_ASSERT(!jinode->i_next_transaction);
+ jinode->i_transaction = transaction;
+ list_add(&jinode->i_list, &transaction->t_inode_list);
+done:
+ spin_unlock(&journal->j_list_lock);
+
+ return 0;
+}
+
+/*
+ * File truncate and transaction commit interact with each other in a
+ * non-trivial way. If a transaction writing data block A is
+ * committing, we cannot discard the data by truncate until we have
+ * written them. Otherwise if we crashed after the transaction with
+ * write has committed but before the transaction with truncate has
+ * committed, we could see stale data in block A. This function is a
+ * helper to solve this problem. It starts writeout of the truncated
+ * part in case it is in the committing transaction.
+ *
+ * Filesystem code must call this function when inode is journaled in
+ * ordered mode before truncation happens and after the inode has been
+ * placed on orphan list with the new inode size. The second condition
+ * avoids the race that someone writes new data and we start
+ * committing the transaction after this function has been called but
+ * before a transaction for truncate is started (and furthermore it
+ * allows us to optimize the case where the addition to orphan list
+ * happens in the same transaction as write --- we don't have to write
+ * any data in such case).
+ */
+int jbd2_journal_begin_ordered_truncate(journal_t *journal,
+ struct jbd2_inode *jinode,
+ loff_t new_size)
+{
+ transaction_t *inode_trans, *commit_trans;
+ int ret = 0;
+
+ /* This is a quick check to avoid locking if not necessary */
+ if (!jinode->i_transaction)
+ goto out;
+ /* Locks are here just to force reading of recent values, it is
+ * enough that the transaction was not committing before we started
+ * a transaction adding the inode to orphan list */
+ spin_lock(&journal->j_state_lock);
+ commit_trans = journal->j_committing_transaction;
+ spin_unlock(&journal->j_state_lock);
+ spin_lock(&journal->j_list_lock);
+ inode_trans = jinode->i_transaction;
+ spin_unlock(&journal->j_list_lock);
+ if (inode_trans == commit_trans) {
+ ret = filemap_fdatawrite_range(jinode->i_vfs_inode->i_mapping,
+ new_size, LLONG_MAX);
+ if (ret)
+ jbd2_journal_abort(journal, ret);
+ }
+out:
+ return ret;
+}