If the underlying filesystem does not support
.BR fallocate (2),
then the operation is emulated with the following caveats:
-.IP * 2
+.IP \(bu 3
The emulation is inefficient.
-.IP *
+.IP \(bu
There is a race condition where concurrent writes from another thread or
process could be overwritten with null bytes.
-.IP *
+.IP \(bu
There is a race condition where concurrent file size increases by
another thread or process could result in a file whose size is smaller
than expected.
-.IP *
+.IP \(bu
If
.I fd
has been opened with the