Re: adding linux syscall fallocate

[Edgar Fuß <ef%math.uni-bonn.de@localhost>]

> You don't have to know where to write.  Strictly speaking you only need
> to know that the space is reserved.
Strictly speaking, yes. But callers of fallocate may expect that the space 
is not only available, mut more-or-less contiguous---as if zeroes had actually 
been written. I.e., when demultiplexing a AV file, fallocate the video output, 
fallocate the audio output, write intertwined and expect a disc layout similar 
to having written all the video at once and then all the audio at once.