From owner-freebsd-fs Fri Nov 5 9:19:37 1999 Delivered-To: freebsd-fs@freebsd.org Received: from parker.yahoo.com (parker.yahoo.com [205.216.162.204]) by hub.freebsd.org (Postfix) with ESMTP id A4C2F1522B for ; Fri, 5 Nov 1999 09:19:25 -0800 (PST) (envelope-from jh@parker.yahoo.com) Received: from parker.yahoo.com (localhost.yahoo.com [127.0.0.1]) by parker.yahoo.com (8.8.8/8.6.12) with ESMTP id JAA23410; Fri, 5 Nov 1999 09:15:46 -0800 (PST) Message-Id: <199911051715.JAA23410@parker.yahoo.com> To: Jan Pechanec Cc: Erez Zadok , Robert Watson , freebsd-fs@FreeBSD.ORG Subject: deadfs, Re: stupidfs - easily extensible test file systems? In-reply-to: Your message of "Fri, 05 Nov 1999 15:23:22 +0100." Date: Fri, 05 Nov 1999 09:15:46 -0800 From: John Hanley Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org > BTW, don't you know why deadfs was written? No doc in FreeBSD. > From what I saw in the source code, operations just fail. Deadfs is so you can V_BAD a vnode to revoke access to a tty or pty. (Or revoke access to a filesystem, upon forcible umount.) There used to be an ugly security problem where someone would log in, start background jobs that can read/write a tty or pty, their login shell exits, and some hapless person logs on to the tty or pty and is abused by the background jobs that still hold an open file descriptor. Nowadays, upon logout we V_BAD those file descriptors and the background jobs can do no harm, but they are allowed to finish their computations and write their results to disk. Cheers, JH To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message