Messages in this thread | | | From | "D. Hazelton" <> | Subject | Re: CD writing in future Linux (stirring up a hornets' nest) | Date | Thu, 9 Feb 2006 22:41:28 -0500 |
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On Friday 10 February 2006 10:38, jerome lacoste wrote: > On 2/10/06, Joerg Schilling <schilling@fokus.fraunhofer.de> wrote: > > "D. Hazelton" <dhazelton@enter.net> wrote: > > > And does cdrecord even need libscg anymore? From having actually gone > > > through your code, Joerg, I can tell you that it does serve a larger > > > purpose. But at this point I have to ask - besides cdrecord and a few > > > other _COMPACT_ _DISC_ writing programs, does _ANYONE_ use libscg? Is > > > it ever used to access any other devices that are either SCSI or use a > > > SCSI command protocol (like ATAPI)? My point there is that you have a > > > wonderful library, but despite your wishes, there is no proof that it > > > is ever used for anything except writing/ripping CD's. > > > > Name a single program (not using libscg) that implements user space SCSI > > and runs on as many platforms as cdrecord/libscg does. > > I have 2 technical questions, and I hope that you will take the time > to answer them. > > 1) extract from the README of the latest stable cdrtools package: > > Linux driver design oddities > ****************************************** Although cdrecord supports to > use dev=/dev/sgc, it is not recommended and it is unsupported. > > The /dev/sg* device mapping in Linux is not stable! Using > dev=/dev/sgc in a shell script may fail after a reboot because the device > you want to talk to has moved to /dev/sgd. For the proper and OS > independent dev=<bus>,<tgt>,<lun> syntax read the man page of cdrecord. > > My understanding of that is you say to not use dev=/dev/sgc because it > isn't stable. Now that you've said that bus,tgt,lun is not stable on > Linux (because of a "Linux bug") why is the b,t,l scheme preferred > over the /dev/sg* one ?
Excellent question. Well Joerg, can you give us a good answer, or will it be more finger pointing, mud slinging and FUD ?
> > 2) design question: > > - cdrecord scans then maps the device to the b,t,l scheme. > - the libsg uses the b,t,l ids in its interface to perform the operations > > So now, if cdrecord could have a new option called -scanbusmap that > displays the mapping it performs in a way that people can parse the > output, I think that will solve most issues.
I'm wondering this myself. If Joerg didn't seem to think everyone in the world was an idiot I'd attempt this myself and submit it.
> cdrecord already has this information available, it just doesn't display > it: > > $ cdrecord debug=2 dev=ATAPI -scanbus 2>&1 | grep INFO > INFO: /dev/hdc, (host0/bus1/target0/lun0) will be mapped on the > schilly bus No 0 (0,0,0) > INFO: /dev/hdd, (host0/bus1/target1/lun0) will be mapped on the > schilly bus No 0 (0,1,0) > > It could perform in the following way: > > $ cdrecord dev=ATAPI -scanbusmap > ... > > 0,0,0 <= /dev/hdc > 0,1,0 <= /dev/hdd > > > Are you accepting such a patch?
If his response to the last patch someone provided is any example the answer is going to be no. And I firmly believe the old adage that a leopard can't change it's spots.
> Jerome
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