September 9, 2004

Reiser4 file semantics: An opportunity for open source

Author: Nurul Choudhury

Some people feel that the Reiser4 file semantics will present problems for the Linux community.
In a nutshell, every file now looks like a directory and can be opened as a directory. The names in that directory are not new files but metadata associated with the file, as documented by Hans Reiser on the Namesys site. The immediate response in the community has been that this is too big a change and should be withdrawn. I humbly propose that this is a challenge we should face head on now or we may not have an opportunity to do so in the future.The best way for open source to fight patents is to create prior art, and you can only create prior art if you have a problem to solve. WinFS is going to give Microsoft the opportunity to discover the problems that have to be solved when faced with a filesystem that offers rich metadata.

We have to innovate to prevent patents corralling all open source development to the old Unix domain. If we are too conservative about the
challenge of change we will be simply spectators while the likes of Microsoft patents all the "trivial ideas" around the rich metadata semantics that Reiser4 has to offer. Instead, we should give to the community the opportunity to discover and solve the problems that using new ways of looking at files and information that we will face.

Much of the "innovation" in computing is
largely trivial or useless over the long term. A few years ago we were told that Unix was a relic of the past and Windows NT was the operating of
the future; today that future is reinventing that relic bit by bit. Microsoft had many good ideas but also many worthless ones, and they are retrofitting much that was implemented in Unix all those years ago. But it has not been a one-way street -- we have borrowed many ideas from Microsoft too.

The challenge of WinFS is not that it will be so great, in the beginning, but that it give Microsoft first crack at tackling and patenting all the trivial little solutions that integrating WinFS into an existing computing environment poses. If we face those issues first we have the
opportunity to create the prior art necessary to defend against the mostly trivial patents
that Microsoft and other will file. If we are too
conservative, there will be no prior art. Companies with patients will stop us dead in our tracks if we do not innovate first.

The new file semantics is both a challenge and an opportunity. Yes, this changes the way we view a file system and what it can be used for. As
others have mentioned, user space solutions would be unworkable because of the huge task
of getting everybody to agree on libraries and converting the huge number of
applications to use common libraries. I strongly agree with Hans that the semantics
should not be removed from Reiser4.

The main issue is to enable file system utilities such as backup and restore, file copy and move, and of course the most interesting of all, version control such as CVS, to work well with rich metadata. Microsoft faces this problem also -- let us not wait for it to patent all the simple ideas around this interesting extension to the file semantics.

I strongly believe in the philosophy that Namesys is proposing -- unifying names space for rich data. The Unix file model was great for its time, but as we attempt to handle terabytes of disk space and files, the real challenge
that open source faces is how to balance the desire for conservative incremental change while pushing the limits of our view of computing.
In the last two decades we have seen 10,000X improvement in the power of the machines
we have available, yet the underlying software infrastructure has improved in relatively modest terms. We need to show that open source is not simply a rehash of other people's technology but is capable of expanding our view of
computing. Otherwise, 20 years from now we will still be asking how we can
compete effectively with Microsoft.

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