From owner-freebsd-fs Mon Oct 7 21:40: 5 2002 Delivered-To: freebsd-fs@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 306FE37B446 for ; Mon, 7 Oct 2002 21:40:00 -0700 (PDT) Received: from cs.rpi.edu (mumble.cs.rpi.edu [128.213.8.16]) by mx1.FreeBSD.org (Postfix) with ESMTP id 66C0043E3B for ; Mon, 7 Oct 2002 21:39:59 -0700 (PDT) (envelope-from crossd@cs.rpi.edu) Received: from pegasus.cs.rpi.edu (pegasus.cs.rpi.edu [128.213.12.48]) by cs.rpi.edu (8.9.3/8.9.3) with ESMTP id AAA47721; Tue, 8 Oct 2002 00:39:53 -0400 (EDT) Received: from pegasus.cs.rpi.edu (crossd@localhost) by pegasus.cs.rpi.edu (8.11.6+Sun/8.9.3) with ESMTP id g984drE16529; Tue, 8 Oct 2002 00:39:53 -0400 (EDT) Message-Id: <200210080439.g984drE16529@pegasus.cs.rpi.edu> X-Authentication-Warning: pegasus.cs.rpi.edu: crossd owned process doing -bs To: bright@mu.org Cc: freebsd-fs@freebsd.org, guptar@cs.rpi.edu Subject: UFS, Inode question Date: Tue, 08 Oct 2002 00:39:52 -0400 From: "David E. Cross" Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org In our Journalling work we just hit a "hmmmm" point where we aren't sure if we've accounted for a certain case. That case is in the point of inode allocation.... to be specific "how (on disk) is an inode marked for allocation" Our current method independently stores inode allocation and linking as discrete events. The problem arises if one is committed without the other (think an inopportune break point in the disk-journal vs. in-core journal.) That could lead to an inode being allocated, but not actually referenced. What does the system do with an inode with a reference count of 0, is that a free inode (on the "free list"). Or can it still be an unreferenced inode? If it can be unreferenced then we need to rethink some things here as the entire point is to avoid fsck. -- David Cross | email: crossd@cs.rpi.edu Lab Director | Rm: 308 Lally Hall Rensselaer Polytechnic Institute, | Ph: 518.276.2860 Department of Computer Science | Fax: 518.276.4033 I speak only for myself. | WinNT:Linux::Linux:FreeBSD To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message