Date: Mon, 4 Jan 1999 16:46:24 -0700 (MST) From: "Kenneth D. Merry" <ken@plutotech.com> To: mike@smith.net.au (Mike Smith) Cc: luigi@labinfo.iet.unipi.it, committers@FreeBSD.ORG Subject: Re: proposed atapi-cd patch Message-ID: <199901042346.QAA60358@panzer.plutotech.com> In-Reply-To: <199901042207.OAA00788@dingo.cdrom.com> from Mike Smith at "Jan 4, 99 02:07:33 pm"
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Mike Smith wrote... > > Hi, > > > > does anyone objects to the following patch for atapi-cd.c to be > > able to mount other than the first data track on one disk ? > > (note that mount_cd9660 -s XXX does not work because it assumes that > > later tracks know about the previous ones). > > > > It (in my opinion) very useful to have multiple data tracks on the same > > disk, e.g. for independent backups. Even more with CDRW media. > > > > This (very small) patch uses a few bits in the minor number to select > > the track, so you need additional device entries in /dev. > > A better approach would involve adding an ioctl to set the track offset > > and call this from mount_cd9660 -- a bit cleaner perhaps, a bit more > > intrusive. > > > > The same thing could be implemented in the SCSI equivalent i guess. > > I think that diffs for both the ATAPI and SCSI drivers (and manpages) > would make this a candidate for immediate inclusion. I'll certainly want to see diffs to the CAM cd driver before they go in. I hesitate to use minor number bits to designate tracks, though. The cd driver currently uses the standard disk minor numbering scheme. It looks like you're using the slice portion of the minor numbering scheme, which limits things to 32 tracks. How many tracks can be on a CD anyway? One (possibly stupid) question I have, though, is why can't the cd9660 code just remember the track offset? The ioctl idea is interesting, but the problem I see is how does the driver know which client a request is coming from, and therefore which offset to use? I think it might be easier if the cd9660 code could handle the track offset stuff. Ken -- Kenneth Merry ken@plutotech.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message
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