Re: reiser4 plugins

Hubert Chan
2005-06-30T19:01:04Z

On Thu, 30 Jun 2005 19:10:57 +0200, David Weinehall <tao@acc.umu.se> said:

> For the analogy to be complete:

> User has a file browser (say Nautilus)
> The file browser sees the userland VFS (say a unified VFS between
> GNOME and KDE)
> The VFS sees the real file system

I would say that this only works if everyone is forced to use the same
VFS. In the web example, everyone is forced to use the same API (HTTP),
and so everyone gets the same view. For the real filesystem, not
everyone is forced to use the hypothetical unified GNOME/KDE VFS. So if
I try to edit with gedit or kate, I get something different than if I
try to edit with vi or emacs.

As I see it:
web browser <-> Nautilus/user apps
web server <-> filesystem
web server's filesystem/database/etc. <-> physical disk storage

Of course, we all know that analogies are not perfect. The layering in
both sides isn't exactly the same. And other people could assign
different equivalences (e.g. web browser <-> Nautilus/user apps; web
server <-> VFS; web server's filesystem <-> filesystem).

Anyways, the analogy wasn't supposed to be about where to handle the
magic extra functionality, whether userspace or kernel space. The
analogy was for people who might think that it's stupid to return
foo/.data when the user tries to open the directory foo; it was meant to
illustrate that that idea isn't completely braindead.

> This way the userland VFS can be ported to almost any platform.

I think GNOME and KDE will always need a VFS if it wants to be
cross-platform. But I think that if the kernel provides extra
functionality, GNOME may be better off. For example, glib provides its
own threading abstraction. But on systems that use pthreads, glib's
threading library uses it for its implementation. And I think it can
even be used on systems that don't offer threading, by doing its own
emulation of threading.

> When toying around on the desktop, an abstraction of what a file is
> works fine with me. When doing serious work (programming, tar:ing up
> stuff, etc) I want to be bloody sure that I see the files in the same
> way always. I don't want surprises such as files suddenly behaving as
> directories or vice versa.

--
Hubert Chan <hubert@uhoreg.ca> - http://www.uhoreg.ca/
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