Re: 2.5.1-pre2 bio offset by one error in VIA IDE

From: Anton Altaparmakov (aia21@cam.ac.uk)
Date: Wed Nov 28 2001 - 20:07:33 EST

At 23:55 28/11/01, Andreas Dilger wrote:
>On Nov 28, 2001 23:31 +0000, Anton Altaparmakov wrote:
> > I just booted my Athlon VIA KT133 chipset box with 2.5.1-pre2 only to
> > discover it dropped me into single user mode because /dev/hda2 could
> not be
> > mounted. (Rebooting into 2.5.0+viro patch everything is ok, back into
> > 2.5.1-pre2 is broken...)
> >
> > Looking with hexedit /dev/hda2 when booted into 2.5.1-pre2 the first
> sector
> > contains junk, the second sector contains the real data that I see as the
> > first sector when booted into 2.5.0+viro fix.
> >
> > That suggests to me there is an off by one error in the VIA IDE driver in
> > the 2.5.10pre2 kernel causing the partition to start one sector earlier
> > than it should.
>
>It may be an issue with your particular partition table having /dev/hda1
>being an odd number of 512-byte sectors long, but Jens' code only doing
>math on 1kB blocks. Just speculation of course. What does "fdisk -ul"
>tell you under the two kernels?

Both exactly the same:

Disk /dev/hda: 255 heads, 63 sectors, 5005 cylinders
Units = sectors of 1 * 512 bytes

    Device Boot Start End Blocks Id System
/dev/hda1 * 63 31471334 15735636 83 Linux
/dev/hda2 31471335 35680364 2104515 83 Linux
/dev/hda3 35680365 39889394 2104515 82 Linux swap
/dev/hda4 39889395 80405324 20257965 f Win95 Ext'd (LBA)
/dev/hda5 39889458 71360729 15735636 83 Linux
/dev/hda6 71360793 75264524 1951866 7 HPFS/NTFS

So everything always starts on same sector. And yes, hda2 starts on an odd
sector.

However, that is not the explanation as the ntfs partition hda6 also starts
with an odd sector but that works fine (using NTFS TNG to mount it and also
looking at start of partition with hexedit).

Best regards,

         Anton 

-- 
   "I've not lost my mind. It's backed up on tape somewhere." - Unknown
-- 
Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @)
Linux NTFS Maintainer / WWW: http://linux-ntfs.sf.net/
ICQ: 8561279 / WWW: http://www-stu.christs.cam.ac.uk/~aia21/

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This archive was generated by hypermail 2b29 : Fri Nov 30 2001 - 21:00:33 EST