Re: UTF-8 and case-insensitivity

Dave Kleikamp
2004-02-17T14:25:29Z

On Mon, 2004-02-16 at 22:12, tridge@samba.org wrote:
> Given how much pain the "kernel is agnostic to charset encoding"
> attitude has cost me in terms of programming pain, I thought I should
> de-cloak from lurk mode and put my 2c into the UTF-8 issue.
>
> Personally I think that eventually the Linux kernel will have to
> embrace the interpretation of the byte streams that applications have
> given it, despite the fact that this will be very painful and
> potentially quite complex. The reason is that I think that eventually
> the Linux kernel will need to efficiently support a userspace policy
> of case-insensitivity and the only way to do case-insensitive filename
> operations is to interpret those byte streams as a particular
> encoding.
>
> Personally I much prefer the systems I use to be case-sensitive, but
> there are important applications that require case-insensitivity for
> interoperability. Right now it is not possible to write a case
> insensitive application on Linux in an efficient manner. With the
> current "encoding agnostic" APIs a simple open() or stat() call
> becomes a horrendously expensive operation and one that is fraught
> with race conditions. Providing the same functionality in the kernel
> is dirt cheap by comparison (not cheap in terms of code complexity,
> but cheap in terms of runtime efficiency).

This would be easy to do in JFS due to the baggage we carried over to be
compatible with OS/2-formatted volumes. In OS/2, the directories were
ordered in a case-insensitive fashion. This would have to be a mkfs
option, and would not be a per-process option. The directories must be
created either case-sensitive or not.

Shaggy
--
David Kleikamp
IBM Linux Technology Center