From owner-freebsd-arch Wed Feb 28 21:11:23 2001 Delivered-To: freebsd-arch@freebsd.org Received: from smtp02.primenet.com (smtp02.primenet.com [206.165.6.132]) by hub.freebsd.org (Postfix) with ESMTP id 5E88B37B719 for ; Wed, 28 Feb 2001 21:11:21 -0800 (PST) (envelope-from tlambert@usr05.primenet.com) Received: (from daemon@localhost) by smtp02.primenet.com (8.9.3/8.9.3) id WAA10662; Wed, 28 Feb 2001 22:04:57 -0700 (MST) Received: from usr05.primenet.com(206.165.6.205) via SMTP by smtp02.primenet.com, id smtpdAAAKSayJt; Wed Feb 28 22:03:48 2001 Received: (from tlambert@localhost) by usr05.primenet.com (8.8.5/8.8.5) id WAA16907; Wed, 28 Feb 2001 22:10:06 -0700 (MST) From: Terry Lambert Message-Id: <200103010510.WAA16907@usr05.primenet.com> Subject: Re: Arch question for a UDF FS driver To: scott_long@btc.adaptec.com (Long, Scott) Date: Thu, 1 Mar 2001 05:10:06 +0000 (GMT) Cc: wollman@khavrinen.lcs.mit.edu ('Garrett Wollman'), arch@FreeBSD.ORG In-Reply-To: from "Long, Scott" at Feb 28, 2001 08:59:46 PM X-Mailer: ELM [version 2.5 PL2] MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > > Hash the Unique Id into 31 bits (e.g., u_id % 2147483647). Renumber > > any collisions into the space above 2**31. You would still need to > > keep some state when there is a collision, but if the Ids are > > assigned sequentially then you are likely to win most of the time. > > Interesting idea. Like I said, consuming 32 bits within the life of the > filesystem is going to be pretty hard. > > > I don't see what this has to do with vget(), however. > > not vget() itself, the vget vfsop. Unless I'm totally clueless here, the > vget vfsop is supposed to return the vnode that repesents the passed in > ino_t. The question to ask yourself is "under what circumstances do I care about the ino_t?". My personal take would be to appeal to the Apple people here, since they have already implemented one of these things, and know how they did it, and the technical reasons why. My gut reaction would be to give ownership of the vnodes to the FS itself, and ignore the problem (search for the string "TFS" in the FS releated kernel code to see what I mean). Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message