Subject: Re: File corruption

From: Ulf Carlsson <[email-masked]>
Date: Wed, 23 Jun 1999 01:49:23 +0200

On Tue, Jun 22, 1999 at 03:21:45PM +0200, Ralf Baechle wrote:
> On Tue, Jun 22, 1999 at 03:29:00AM +0200, Ulf Carlsson wrote:
> 
> > This is *really* annoying, I can't do anything without getting interrupted
> > by some bug on the Indy.  I can't stand this file corruption.  I just lost
> > an entire directory.  This isn't because of crashes, stuff just vanish, or
> > gets corrupted without any reason.  I for example had a gzipped patch, I
> > decompressed it and I got a lot of junk in the middle of the file.
> 
> Question, is this effect repeatable, that is if you decompress the file a
> second time, will you still see the filesystem corruption?  The latter would
> mean that the data decompressed data get corrupted on the fly and the SCSI
> driver isn't involved.  Or does the gzip'ed file itself already contain the
> corrupted data?

Since the file is decompressed without warnings I assume that the scp went fine.
Anyhow, when I had decompressed the file I got corruption in the middle of the
patch.  The corruption affected only a couple of lines, 10 or so.

The problems I experience are not repeatable.  Everything went smooth after a
reboot.  I usually reboot the machine when it's messing with me, that helps.  At
least for a while.

> And under which kernel version did this start to happen?

2.2.1 I think.

> Could you resend me your hinv output?

Unfortunately I don't have IRIX.  However, I have a 133 MHz R4600 CPU with 512 k
board cache.  I have two 1 Gb SCSI driver connected.

> > Earlier today the cached version of /lib/libpam_misc.so.0.64 was corrupted
> > or something, and corrupted ELF headers were reported.  A reboot fixed that
> > one.
> 
> It seems that you observe similar problems like me.  For me however the
> problem has just vanished and was rare anyway.

They're rare for me as well, but I've had a couple in just a few days now.
Maybe the file corruption became heavier since 2.3.6?

> I understand that very well.  Btw, I started to store important stuff on NFS.

I can't stand NFS. Files, or entire directories vanish from ls, but I may still
open them if I specify their names directly.  I think I've been talking to you
about this before.

- Ulf

---

From: Ralf Baechle <[email-masked]>
Date: Fri, 25 Jun 1999 00:28:53 +0200

> > And under which kernel version did this start to happen?

Are you shure?  The problem Alan is tracking started to hit from 2.2.7 on.
If 2.2.1 already starts making these kind of troubles then we probably
track two different problems.

> board cache.  I have two 1 Gb SCSI driver connected.

Is this a low-mem configuration?  The problem Alan is tracking apparently
seems to hit low mem systems more often.

  Ralf

---

From: Ulf Carlsson <[email-masked]>
Date: Fri, 25 Jun 1999 15:31:08 +0200

> Are you shure?  The problem Alan is tracking started to hit from 2.2.7 on.  If
> 2.2.1 already starts making these kind of troubles then we probably track two
> different problems.

Probably.  I have a new problem with the 2.3.8 kernel now as well:  Page->owner
becomes -1 at line 1218 in buffer.c, thus forcing an oops.  This happens when I
try to cat a couple of big files into a new file.  This is even reproduceable...

I get some error messages before the oops as well:

attempt to access beyond end of device
08:01: rw=0, want=122156967, limit=929559
attempt to access beyond end of device
08:01: rw=0, want=886680107, limit=929559

> > Unfortunately I don't have IRIX.  However, I have a 133 MHz R4600 CPU with
> > 512 k board cache.  I have two 1 Gb SCSI driver connected.
> 

Not really, I have 128 Mb RAM, but no swap.

Regards,
Ulf

---

From: "Andrew Linfoot" <[email-masked]>
Date: Fri, 25 Jun 1999 15:34:15 +0100

I have been running 2.2.1 on my indy for about 3 weeks now and have
encountered problems like this,
in fact i am surprised at how stable the box is, i have been doing some
quite large builds of qt, kde and the like too. If this is reproducible then
i would be prepared to experiment on one of my boxes.

The only gripe i have is that the scsi driver breaks when i attach external
devices, any ideas?

Andy

---

From: Ulf Carlsson <[email-masked]>
Date: Fri, 25 Jun 1999 18:59:06 +0200

On Fri, Jun 25, 1999 at 03:34:15PM +0100, Andrew Linfoot wrote:
> encountered problems like this, in fact i am surprised at how stable the box
> is, i have been doing some quite large builds of qt, kde and the like too. If
> this is reproducible then i would be prepared to experiment on one of my
> boxes.

It doesn't crash, only file corruption..

> The only gripe i have is that the scsi driver breaks when i attach external

I have file corruption without any external devices.  It looks like the problems
appear when more than one SCSI devices are present.  You only have one internal
SCSI drive, right?

Do you mind telling us more exactly what type of file corruption you suffer
from?  It would also help if you could attach an output from hinv, or just tell
us what hardware you have.

Regards,
Ulf

---

From: "Andrew Linfoot" <[email-masked]>
Date: Fri, 25 Jun 1999 18:11:52 +0100

On a couple of occasions i have lost entire directories but this was some
time ago
----- Original Message -----
From: Ulf Carlsson <[email-masked]>
To: Andrew Linfoot <[email-masked]>
Cc: <[email-masked]>
Sent: Friday, June 25, 1999 5:59 PM
Subject: Re: File corruption

> > this is reproducible then i would be prepared to experiment on one of my
I have had a couple of instances where i lost complete directories, but this
was during the first few days of running Linux on my box, i simply put it
down to operator error!
> appear when more than one SCSI devices are present.  You only have one
internal
2 drives - see below
If i attempt to attach an external device the system just hangs during scsi
initialisation. I think this is fixed in later kernels but i don't have cvs
up yet so i can't move past 2.2.1.
> us what hardware you have.
CPU: MIPS-R4400 FPU<MIPS-R4400FPC> ICACHE DCACHE SCACHE
Loading R4000 MMU routines.
CPU revision is: 00000450
Primary instruction cache 16kb, linesize 16 bytes)
Primary data cache 16kb, linesize 16 bytes)
Secondary cache sized at 1024K linesize 128
8-bit graphics
128MB RAM
sda 540MB with base IRIX
sdb 2GB with Linux.and swap

an interesting point here is that /proc/cpuinfo tells me i only have an
r4000!

Andy

---

From: Thomas Bogendoerfer <[email-masked]>
Date: Fri, 25 Jun 1999 20:08:37 +0200

> Probably.  I have a new problem with the 2.3.8 kernel now as well:  Page->owner
[...]
> 08:01: rw=0, want=886680107, limit=929559

this seems to be a normal 2.3 error. At least I get this impression, when
reading the linux-kernel mailinglist.

Thomas.

-- 
   This device has completely bogus header. Compaq scores again :-|
It's a host bridge, but it should be called ghost bridge instead ;^)
                                        [Martin `MJ' Mares on linux-kernel]

---

From: Ralf Baechle <[email-masked]>
Date: Mon, 28 Jun 1999 11:34:54 +0200

> The only gripe i have is that the scsi driver breaks when i attach external

There is nothings special with external devices, so if they result in
crashes you should double check that cabeling and termination are ok.

  Ralf

---

From: Ralf Baechle <[email-masked]>
Date: Mon, 28 Jun 1999 12:39:50 +0200

> CPU: MIPS-R4400 FPU<MIPS-R4400FPC> ICACHE DCACHE SCACHE

This is what the firmware detected.

> Loading R4000 MMU routines.

This will always say R4000 if it's a R4000 class CPU.

> Secondary cache sized at 1024K linesize 128

Which says that you have an R4400SC V5.0.

> an interesting point here is that /proc/cpuinfo tells me i only have an

Good spotting, the CPU detection code has a bug causes only V4 CPUs to be
detected as R4400.  The difference is just cosmetics; R4000 and R4400 are
almost the same.  Especially it's unrelated to the file corruption problem.

  Ralf