Re: silent semantic changes with reiser4

Spam
2004-09-06T15:13:39Z

> Spam <spam@tnonline.net> writes:

>> >> The problem with the userspace library is standardization. What
>> >> would be needed is a userspace library that has a extensible plugin
>> >> interface that is standardized. Otherwise we would need lots of
>> >> different libraries, and I seriously doubt that 1) this will happen
>> >> and 2) we get all Linux programs to be patched to use it.
>>
>> > libvfs from midnight commander (and anything build on the top of it)
>> > already is very extensible.
>>
>> This wasn't my point. My point was about all applications using it.
>> Most aren't.

> So why do you think that just because you put an interface into the
> everyone will automatically start using it and use it without any
> conflicts (i.e. is foo/icon a windows icon, a gif, png, or jpeg file,
> what size is it, 16x16, 48x48...).

> When you add a new shared namespace, userspace must be taught about it
> anyways. So start with a userspace library, convince people to use
> it, and when you know what people want, _then_ put it into the kernel
> to increase performance or security.

Several aspects of this;

1) Programs will need to actually be coded against this shared
library which probably will be more advanced that just usning normal
file access code.

2) Then we redo it all again to fit in the kernel, as a kernel
plugin or user-level plugin.

> Don't start with "wouldn't it be
> nice if" without any thought behind it, it will just mean that we get
> another useless and misdesigned interface in the kernel that we have
> to live with for years.

I am not saying that there should not be any thought behind
implementing something. But from many hear I just hear a big no,
without any thought about it either.

Named streams and meta files are just one example of a general
access to extra data that belongs to files. It seem to me as a much
simpler way for program to use those than to link in several various
libraries to do the same thing.

Plugins were just another thing that could extend the functionality
of these streams and meta data. Reiser4 has a plugin architecture,
although not yet any run-time support for loading them. Is this so
bad that we have to prevent it?

No one has to use them. maybe at some point it would be possible to
specify which classes of plugins that could be loaded by a user and
his files.

What are the complaints about. The technical challenge to make
things like this secure, or the concept to have this functionality
at all. I do not think that because something is hard to do, it
should be dismissed.

~S

> Do you know how long it took to get rid of /dev/cua0 and the locking
> mess associated with it? (Deity! I just checked on my FC2 system,
> it's still there. I thought it would be dead by now.)

> /Christer