Btrfs: fix transaction leak during fsync call

If btrfs_log_dentry_safe() returns an error, we set ret to 1 and
fall through with the goal of committing the transaction. However,
in the case where the inode doesn't need a full sync, we would call
btrfs_wait_ordered_range() against the target range for our inode,
and if it returned an error, we would return without commiting or
ending the transaction.
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>

fs/btrfs/file.c

@@ -2025,9 +2025,11 @@ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
 		if (!full_sync) {
 			ret = btrfs_wait_ordered_range(inode, start,
 						       end - start + 1);
-			if (ret)
+			if (ret) {
+				btrfs_end_transaction(trans, root);
 				goto out;
 			}
+		}
 		ret = btrfs_commit_transaction(trans, root);
 	} else {
 		ret = btrfs_end_transaction(trans, root);