From owner-freebsd-fs Tue Mar 31 09:09:04 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id JAA22334 for freebsd-fs-outgoing; Tue, 31 Mar 1998 09:09:04 -0800 (PST) (envelope-from owner-freebsd-fs@FreeBSD.ORG) Received: from camel7.mindspring.com (camel7.mindspring.com [207.69.200.57]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id JAA22306 for ; Tue, 31 Mar 1998 09:09:02 -0800 (PST) (envelope-from sbsmyth@mindspring.com) Received: from mindspring.com (user-37kb5bs.dialup.mindspring.com [207.69.149.124]) by camel7.mindspring.com (8.8.5/8.8.5) with ESMTP id MAA20970 for ; Tue, 31 Mar 1998 12:08:51 -0500 (EST) Message-ID: <3520FBE2.B12EB7F7@mindspring.com> Date: Tue, 31 Mar 1998 09:21:22 -0500 From: Scott Smyth X-Mailer: Mozilla 4.03 [en] (X11; I; Linux 2.0.33 iU86) MIME-Version: 1.0 To: freebsd-fs@FreeBSD.ORG Subject: Possibility of Porting BSD fs to Linux and vice-versa? Possible? Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org I have been pondering the possibility of porting filesystems back and forth between BSD and Linux. Could someone shed some light on whether porting a BSD-supported filesystem to Linux or vice-versa is fundamentally possible? I think it is, but I wonder if there is something missing from my understanding. What are the issues involved? Specifically, I have been looking at the Union FS, but more generally, what porting issues are involved. Applications are easy from both directions...what about a fs? By the way, I use both. Thanks, Scott -- Scott Smyth (770) 923-2004 sbsmyth@mindspring.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message From owner-freebsd-fs Tue Mar 31 19:30:06 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id TAA28295 for freebsd-fs-outgoing; Tue, 31 Mar 1998 19:30:06 -0800 (PST) (envelope-from owner-freebsd-fs@FreeBSD.ORG) Received: from parkplace.cet.co.jp (parkplace.cet.co.jp [202.32.64.1]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id TAA28286 for ; Tue, 31 Mar 1998 19:30:04 -0800 (PST) (envelope-from michaelh@cet.co.jp) Received: from localhost (michaelh@localhost) by parkplace.cet.co.jp (8.8.8/CET-v2.2) with SMTP id DAA06400; Wed, 1 Apr 1998 03:27:25 GMT Date: Wed, 1 Apr 1998 12:27:25 +0900 (JST) From: Michael Hancock To: Scott Smyth cc: freebsd-fs@FreeBSD.ORG Subject: Re: Possibility of Porting BSD fs to Linux and vice-versa? Possible? In-Reply-To: <3520FBE2.B12EB7F7@mindspring.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Tue, 31 Mar 1998, Scott Smyth wrote: > I have been pondering the possibility of porting filesystems back and > forth between BSD and Linux. Could someone shed some light on whether > porting a BSD-supported filesystem to Linux or vice-versa is > fundamentally possible? I think it is, but I wonder if there is > something missing from my understanding. What are the issues involved? > Specifically, I have been looking at the Union FS, but more generally, > what porting issues are involved. Applications are easy from both > directions...what about a fs? By the way, I use both. It's possible, but far more work than porting user applications where there are standards that are exposed externally. It's kernel programming so the internals differ significantly. UnionFS doesn't stack well so it must consume a lot of internal kernel interfaces. Nullfs on the otherhand would be a lot easier. Regards, Mike To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message From owner-freebsd-fs Wed Apr 1 18:10:08 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id SAA25522 for freebsd-fs-outgoing; Wed, 1 Apr 1998 18:10:08 -0800 (PST) (envelope-from owner-freebsd-fs@FreeBSD.ORG) Received: from parkplace.cet.co.jp (parkplace.cet.co.jp [202.32.64.1]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id SAA25431; Wed, 1 Apr 1998 18:10:00 -0800 (PST) (envelope-from michaelh@cet.co.jp) Received: from localhost (michaelh@localhost) by parkplace.cet.co.jp (8.8.8/CET-v2.2) with SMTP id CAA13638; Thu, 2 Apr 1998 02:09:15 GMT Date: Thu, 2 Apr 1998 11:09:15 +0900 (JST) From: Michael Hancock To: freebsd-fs@FreeBSD.ORG, freebsd-current@FreeBSD.ORG Subject: softupdates and delayed binding of physical block addresses Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org It looks like some of the recent patches have been to take care of FreeBSD optimizations that weren't in 4.4BSD. Delayed binding of physical block addresses to logical block addresses is a good thing and if we can incorporate softupdates and minimize the reduction of these delayed bindings we are going to have a *very* fast file system. Mike To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message