[lkml]   [2006]   [Feb]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: CD writing in future Linux (stirring up a hornets' nest)
    On Friday 10 February 2006 10:38, jerome lacoste wrote:
    > On 2/10/06, Joerg Schilling <> wrote:
    > > "D. Hazelton" <> 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

    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2006-02-11 04:47    [from the cache]
    ©2003-2014 Jasper Spaans. hosted at Digital Ocean