Linux: Was reading past end of file fixed?

[Doug Ledford]

Greg Wickham wrote:
> 
> Hi Doug,
> 
> I didn't mean to imply that it was aic7xxx error.
> 
> However i do feel that the bug I reported is a kernel
> error of somekind.
> 
> Once it happens, if I reboot and do an fsck everything
> is _perfectly_ normal. It is a worry.

This usually means it is a hardware error of some sort that corrupts the in
memory cache.  Once you reboot the cache is cleared of course, so the
problem does go away and e2fsck doesn't find anything.

> As far as I can tell the hardware is functioning
> perfectly. No other error is reported.
> 
> Maybe there is a bug in the scsi code .. :(
> It is damn hard to produce though. Only ever
> happens when I least need it.

I'm Cc:ing this to aic7xxx list because this test is fairly valuable at
finding out these kinds of problems.  To test for hardware bit flips related
to heavy DMA load, I usually recommend running this script (you'll need at
least roughly 50MB of free drive space on your /usr/src partition):

1.  Get a linux-x.y.z.tar.gz tarball.
2.  Put that tarball into /usr/src
3.  Backup any existing /usr/src/linux directory to /usr/src/linux.save
4.  Extract that linux-x.y.z.tar.gx file.
5.  Move the new /usr/src/linux directory to /usr/src/linux.orig
6.  Run the following shell script:

#!/bin/sh
cd /usr/src
for i in 1 2 3 4 5 6 7 8 9 10
do
  tar -xzf linux-x.y.z.tar.gx
  diff -U 3 -rN linux.orig linux
  rm -fr linux
done

If that little shell script produces any visible output, then you have
hardware problems.

> ]   Opinions expressed are my own, but
> ]      they should be everybody's.
> 
> why :)

I am the computer God :)  Just kidding, I was in an arrogant mood one night
and just came up with that to sound pompous and arrogant :)  It was also
meant to be a poke at all those people with those annoying "Opinions
expressed are my own and not necessarily those of my employer"
Duhhh...like I have to be told that you and some corporate entity are not
the same unless you claim to be speaking on behalf of that company.  Oops, I
forgot about all the lamers out there that assume anyone talking from some
domain talk for that domain.  IOW, my sig is both a joke and a
political/social commentary.
-- 

 Doug Ledford  <dledford at dialnet.net>
  Opinions expressed are my own, but
     they should be everybody's.

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