Date: Sat, 26 Sep 1998 08:47:58 +0200 (MET DST) From: Luigi Rizzo <luigi@labinfo.iet.unipi.it> To: luigi@labinfo.iet.unipi.it (Luigi Rizzo) Cc: current@FreeBSD.ORG, sos@FreeBSD.ORG Subject: Re: cd9660 mounts... Message-ID: <199809260647.IAA14017@labinfo.iet.unipi.it> In-Reply-To: <199809251242.OAA12463@labinfo.iet.unipi.it> from "Luigi Rizzo" at Sep 25, 98 02:42:25 pm
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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
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