From owner-freebsd-current Sat Sep 26 01:35:39 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id BAA07566 for freebsd-current-outgoing; Sat, 26 Sep 1998 01:35:39 -0700 (PDT) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from labinfo.iet.unipi.it (labinfo.iet.unipi.it [131.114.9.5]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id BAA07560; Sat, 26 Sep 1998 01:35:34 -0700 (PDT) (envelope-from luigi@labinfo.iet.unipi.it) Received: from localhost (luigi@localhost) by labinfo.iet.unipi.it (8.6.5/8.6.5) id IAA14017; Sat, 26 Sep 1998 08:47:59 +0200 From: Luigi Rizzo Message-Id: <199809260647.IAA14017@labinfo.iet.unipi.it> Subject: Re: cd9660 mounts... To: luigi@labinfo.iet.unipi.it (Luigi Rizzo) Date: Sat, 26 Sep 1998 08:47:58 +0200 (MET DST) Cc: current@FreeBSD.ORG, sos@FreeBSD.ORG In-Reply-To: <199809251242.OAA12463@labinfo.iet.unipi.it> from "Luigi Rizzo" at Sep 25, 98 02:42:25 pm X-Mailer: ELM [version 2.4 PL23] Content-Type: text Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Yesterday i mentioned that it was not possible (at least on 2.2.6) to mount CD9660 disks where the data track was not at offset 0 (i.e. the first track on the disk). I have looked at the code in /sys/isofs/cd9660/ and my impression is that the same problem exists on -current, although the mount might work if the data track has info on its ABSOLUTE location on disk. For sure, it will NOT work with mkisofs-generated files. In order to enable mounting for multitrack CDs, i thought at first it was just a matter to account for the start-of-track offset in the bread() calls in /sys/isofs/cd9660/, but it seems not to be the case since there are VREF/vget calls which appear to get confused by this. An alternative hack (which seems to work and requires very little modification -- just 4 lines in the device driver!) is to use the device minor number to identify the track, so that you can say mount -t cd9660 -o -s=0 /dev/wcd0tN /cdrom to mount the n-th track. In the above you _need_ to specify the "-s=0" option to mount_cd9660 because otherwise it tries to access the last data track on the disk. Opinions ? Is this something worth adding to the system ? It is totally backward compatible and nonintrusive. cheers luigi -----------------------------+-------------------------------------- Luigi Rizzo | Dip. di Ingegneria dell'Informazione email: luigi@iet.unipi.it | Universita' di Pisa tel: +39-50-568533 | via Diotisalvi 2, 56126 PISA (Italy) fax: +39-50-568522 | http://www.iet.unipi.it/~luigi/ _____________________________|______________________________________ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message