The POSIX file system

[Moderator, John Quarterman]

From: rgenter at labs-b.bbn.com (Rick Genter)
Date: 30 Oct 86 09:57:13 EST (Thu)

Here's the text of my original article, modified to reflect dmr's comments:

     The recent discussion regarding the issue of case insensitivity in the
POSIX environment has caused me to think about the Unix file system and
its impact on the kernel.  I came into the Unix game late, but as I understand
it, various flavors of Unix (such as MERT, Unix' real-time cousin), 
implemented the file system completely outside the kernel, I suppose as a
library of routines.  I also understand that the MACH project at CMU is 
heading in this direction.

     The primary reason that I see for having the file system in the kernel in
the first place is perhaps for efficiency and to solve certain concurrency
problems.  I see making the file system case insensitive as another step in
this direction; unfortunately I see it as a step backwards.  I suppose the
next logical step would be to put wildcard expansion in the kernel.

     If any sort of fundamental change is to be made to the file system for
POSIX, I'd prefer moving towards a non-kernel file system.  In addition to
simplifying the design of the operating system, it also allows users to
implement layers on top of the file system, such as case insensitivity,
wildcard expansion, network file systems, access methods, etc.  Gee, is this
starting to sound like streams?

     Personally, I'd rather that POSIX not change the appearance of the Unix
file system; it's too big a task to do right involving a redesign rather 
than a standardization.  This is clearly (at least to me) outside the scope 
of an effort such as P1003.
--------
Rick Genter 				BBN Laboratories Inc.
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rgenter at labs-b.bbn.COM  (Internet new)	Cambridge, MA   02238
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Volume-Number: Volume 8, Number 13