Re: Msdos name alias patch for 2.1.48

docwhat@gerf.org ;The Doctor What ("docwhat@gerf.org)
Fri, 08 Aug 1997 11:54:42 -0700

Telephone Game! Linus Torvalds said (on 09:31 AM 8/8/97 -0700):
<SNIP>
->HOWEVER. If we can make that name translation generic enough that it works
->for _all_ filesystems (even ext2 if you want it to), and there are no
->filesystem-specific hooks for it, then I already start likin git a lot
->more. Then it goes from being "damn ms-dos braindamage that we have to
->hack around" to being "the VFS layer can handle case-insensitive names".
->
->Further, if the new feature then allows us to actually give value-added
->features to user space (like a O_NOCASE flag), it goes from "the VFS layer
->can handle case-insensitive names" to "hey cool, we can do THIS, and it's
->really useful for this class of applications".
->
->Does this explain my motivation a bit? Essentially, I'm NOT really
->interested in how we can make the MS-DOS filesystem work.
->
->I'm interested in seeing something that might be a good VFS feature to
->have anyway, and that _ALSO_ happens to make MS-DOS (and NTFS and..)
->happy, but more importantly I want it to make sense on some level even
->_without_ that.

------------
Thought One: Summary

Okay...so the idea is that Case-insensitivity is something that can be
applicable to all FS's (if one desires), while 8.3 munging isn't.

That means the following...

VFS layer handles Case insensitivity - configurable

MSDOSFS layer handles 8.3 - else returns error and legalchar - else
returns error. I assume legalchar checking checks for '.' and '..'
problems.

------------
Thought Two: Case preserving case insensitivity

Someone mentioned that OS/2 HPFS has "Case Preserving Case
Insensitivity" (aka CPCI)? Anyway, that you can create a file with a
specific case and then read it back using a different case.

Would it be disable to bundle that with O_NOCASE? It seems to me to be
more desirable, both from a user POV and Not-A-Big-Deal from a
programmers POV.

It would be there for OS/2 people who wanted it and MS-DOS will never know.
Err... let me clarify: I believe that command.com cannot *tell* that a
file has a specific case.

Well...I guess I've gotta go be productive.

Ciao!

--
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