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Path: utzoo!mnetor!seismo!cmcl2!phri!orville!dvm!dave
From: dave@dvm.UUCP (David Brand)
Newsgroups: comp.unix.wizards
Subject: Re: lockf and the SVID, (Was "Re: Wanted: lockf system call source")
Message-ID: <124@dvm.UUCP>
Date: Tue, 2-Dec-86 21:34:52 EST
Article-I.D.: dvm.124
Posted: Tue Dec  2 21:34:52 1986
Date-Received: Wed, 3-Dec-86 06:12:09 EST
References: <5413@brl-smoke.ARPA> <2264@sdcsvax.UCSD.EDU>
Reply-To: dave@dvm.UUCP (David Brand)
Organization: Philon, Inc. (NY, NY)
Lines: 18

In article <2264@sdcsvax.UCSD.EDU> hutch@sdcsvax.UUCP (Jim Hutchison) writes:

>Not that H-P is at fault for following the mighty SVID, but why require
>that the file-descriptor is open for write to do a write lock?  Wouldn't

Requiring that a file be open in write mode is a sure fire way of requiring
that the user have write premission.  An implementation should require that
a process have write permission on the file before allowing MANDATORY write
mode locks to prevent unauthorized denial of resources (eg. locking
/etc/passwd).  This restriction is then carried over into ADVISORY locks for
consistency.

This is often cited as the reason to leave out mandatory locks entirely.
-- 

					- Dave

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