-the first part of the file. If @var{length} is greater than
-@var{fd}'s length, when the file's length is also rounded up to the
-nearest multiple of the page size, the call should fail. Ideally it
-would extend the file, but our file system does not yet support
-growing files.
+the first @var{length} bytes of the file. If @var{length} is greater
+than @var{fd}'s length, when the file's length is also rounded up to a
+page multiple, the call should fail. Ideally it would extend the
+file, but our file system does not yet support growing files.