Re: silent semantic changes with reiser4

From: Linus Torvalds
Date: Thu Aug 26 2004 - 16:09:41 EST




On Thu, 26 Aug 2004, Martin J. Bligh wrote:
>
> What would "test -d" and "test -f" return on these magic beasties? I can't
> think of any combinations that wouldn't confuse the crap out of userspace.

"It's a feature".

The S_ISDIR/S_ISREG tests show real information: it shows not only user
intent ("you should consider this a file, even if it has attributes"), but
also whether it is a directory or a container.

And there's a real technical difference there: the streams contained
within a file are bound to that file. The files contained within a
directory are _independent_ of that directory. Big difference. HUGE
difference.

So it's not confusing. If it tests as a file, you think of it as a file.
It may have attributes aka named streams associated with it, and you may
be able to open those attributes by treating the file as a directory, but
that doesn't really change the fact that it's a file.

The _big_ difference is that when you can make the compound object _look_
like a directory, that means that you can now manage the attributes with
standard tools. They are still attributes, though.

Linus
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