Re: Kernel Panic, root fs..

david parsons (o.r.c@p.e.l.l.p.o.r.t.l.a.n.d.o.r.u.s)
17 Aug 1999 16:15:07 -0700

In article <linux.kernel.Pine.LNX.3.95.990817155201.31582A-100000@chaos.analogic.com>,
Richard B. Johnson <root@chaos.analogic.com> wrote:
>On 17 Aug 1999, david parsons wrote:
>
>> In article <linux.kernel.Pine.LNX.3.95.990817090722.13436A-100000@chaos.analogic.com>,
>> Richard B. Johnson <root@chaos.analogic.com> wrote:
>> >On Tue, 17 Aug 1999, Dan Hollis wrote:
>>
>> >> <QUOTE>
>> >> Kernel Panic: Couldnt mount /dev/sda1 on root fs, perhaps you forgot to
>> >> compile in scsi support?
>> >> </QUOTE>
>>
>> >Big strings mean big kernels. Not too good. The kernel doesn't
>> >know, and *** must not know *** about 'dev/sda1'.
>>
>> Too late, I'm afraid.
>>
>> The de facto standard names are already known to the kernel (cf:
>> init/main.c::name_to_kdev_t(), just for an example) and it is
>> somewhat silly to have this one place spit out a magic code after
>> the kernel has just finished telling you (for example)
>>
>> sda : READ CAPACITY failed.
>> sda : status = 1, message = 00, host = 0, driver = 28
>> sda : extended sense code = 2
>> sda : block size assumed to be 512 bytes, disk size 1GB.
>> Partition check:
>> sda:scsidisk I/O error: dev 08:00, sector 0
>> unable to read partition table
>> hda: hda1 hda2 hda3
>>

>Yep. And it shows you why it's not correct! The SCSI disk devices
>are not named hda: hda1, hda3, etc.,

I think you may misunderstand; the klog snippet I posted, which
does show that the kernel already knows about, is from one of my
development workstations, and not from the offending machine.

Even leaving aside my opinion that major and minor numbers are the
most odious sort of black magic, the kernel as it stands today knows
about the de facto standard for device names, and already has code
that can decode and encode the black magic. The code bloat needed
to tuck skeleton tables for majors that aren't compiled in becomes
nothing more than a simple major/minor->name mapping, which is
probably a whopping 4k.

I'd produce a patch, but I've already got a large pile of patches
waiting for Linux to notice them.

____
david parsons \bi/ It's not bloat when it leads to clearer diagnostics.
\/

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