Re: 2.5.49: Severe PIIX4/ATA filesystem corruption

[H. Peter Anvin]

Alan Cox wrote:
> On Tue, 2002-11-26 at 21:07, H. Peter Anvin wrote:
> 
>>So, I finally braved it and tried running 2.5.49 on my workstation to
>>test out my RAID-6 patches.  There were no patches outside the md
>>area, and the ordinary filesystems aren't on md drives.
>>
>>The two SCSI drives (SymBIOS controller) work just fine, but I have
>>gotten repeated, severe data corruption on the one ATA drive in the
>>system after only a few hours of operation.
> 
> 
> If you mash the innards of the page cache you'll get corruption
> everywhere, its one of the charms of testing out that area of the code
> on Linux. You might want to debug using 2.5.49 user mode linux rather
> than on raw disks. Its so much easier to use "cp" to generate a
> replacement root_fs 8)
> 

Yes, that's true.  However, the heavily used two SCSI disks saw no 
corruption whatsoever, whereas the single, lightly used ATA disk saw 
heavy corruption; if it was due to experimental unrelated code one would 
have expected corruption everywhere.  This does not mean that it is not 
my fault (as far as UML is concerned, I tried building it quite a few 
times before giving up), but given the severity of the corruption I was 
seeing I thought I'd raise a red flag.

	-hpa