Date: Wed, 25 Aug 1999 03:12:55 +1000 (EST) From: Andrew Kenneth Milton <akm@mail.theinternet.com.au> To: chris@netmonger.net (Christopher Masto) Cc: wes@softweyr.com, grog@lemis.com, chuckr@picnic.mat.net, drosih@rpi.edu, dcs@newsguy.com, phk@critter.freebsd.dk, dillon@apollo.backplane.com, hackers@FreeBSD.ORG, cvs-committers@FreeBSD.ORG, wollman@khavrinen.lcs.mit.edu Subject: Re: Mandatory locking? Message-ID: <199908241712.DAA68570@mail.theinternet.com.au> In-Reply-To: <19990824111703.B10650@netmonger.net> from Christopher Masto at "Aug 24, 1999 11:17: 3 am"
next in thread | previous in thread | raw e-mail | index | archive | help
+----[ Christopher Masto ]--------------------------------------------- | | that no other processes are using it." How do you know someone | hasn't, say, opened it in an editor, made some changes, and is about | to save? File Permissions, it's a pretty fundamental UNIX philosophy. How do you know someone hasn't opened your kernel in an editor, made some changes and is about to save? It's not about stopping random users doing random actions to files. It's about (almost) transparently enabling processes to cooperate using a shared resource. Think of it as a mutex on a part/whole file. Mandatory locking enables a process to ensure that its transaction is safe from interference. Interference that can come from a correctly running program writing at the wrong time (but not using the locks -- maybe you don't have source for it either). What happens if root-owned process X has gone off the deep-end and is randomly writing crap into every file on your filesystem? Well you're hosed anyway. -- Totally Holistic Enterprises Internet| P:+61 7 3870 0066 | Andrew The Internet (Aust) Pty Ltd | F:+61 7 3870 4477 | Milton ACN: 082 081 472 | M:+61 416 022 411 |72 Col .Sig PO Box 837 Indooroopilly QLD 4068 |akm@theinternet.com.au|Specialist To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199908241712.DAA68570>