Re: PROBLEM: bad device file for cdrom while using devfs and ide-scsi

From: Mamoru Yamanishi (yama@biotech.okayama-u.ac.jp)
Date: Fri Jan 17 2003 - 05:26:35 EST


Thanks replying.

> > [2.] Full description of the problem/report:
>>
>> I use Kernle-2.4.20 with devfs and ide-scsi.
>> "devfs" is mounted at boot.
>>
>> I wonder that the symbolic-link to actual device file of cdrom is not
>> correct, which is placed in /dev as
>>
> > "cdrom0 -> ../scsi/host0/bus0/target0/lun0/cd"
>>
>> It should be placed in subdirectory /dev/cdroms, or it should be
>> linked to "scsi/host0/bus0/target0/lun0/cd", I think.
>>
>> Without ide-scsi, there is /dev/cdroms/cdrom0 which is correctry
>> linked to actual device file.
>>
>> I was looking around the kernel source codes, but I cannot find
>> where it was.
>
>Are you sure that sr_mod is loaded? After installing ide-scsi the cdrom drive
>is a scsi cdrom so you must load the scsi cdrom driver (module sr_mod). If it
>is not in the `lsmod` output you should try "modprobe sr_mod".

The problem is only mis-linked device file.

        # My cdrom can be accessed with /dev/sr0, which is
        # SCSI CD-ROM driver. For previous compatibility,
        # I make a symbolic link /dev/sr0 to /dev/cdrom,
        # and they works fine.

Device files under devfs are dynamically generated by kernel, right?
For some representative devices, I think, the symbolic links are
also made for user's convenience. "cdrom0" and "sr0" are such
links, I think. On my environment, "sr0" has proper link to
actual one, but "cdrom0" do not.

The kernel might generate these links, right?
So I wonder there are some bugs.

Considering the behavior when I boot without ide-scsi, I think
proper place, where "cdrom0" is placed, is /dev/cdroms/cdrom0.
If so, the link "cdrom0 -> ../scsi/host0/bus0/target0/lun0/cd"
become ok.

Sorry for bad explanation in English.

-- 
-------------8<-------------8<-------------8<-------------
Mamoru Yamanishi, Ph. D. <yama@biotech.okayama-u.ac.jp>

Department of Bioscience and Biotechnology Faculty of Engineering, Okayama University +81-86-251-8196(voice)/+81-86-251-8264(GIII fax) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/



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