Subject: 1.0A Repeated "panic: ffs_alloccg" Any ideas?
To: None <>
From: Mark Delany <>
List: current-users
Date: 10/10/1994 20:31:55
Howdy. I'm after a little help.

I've just upgraded from 0.9B of ancient vintage to 1.0A with a sup
date of 8/10/94 and now I get repeated panics out of ffs_allo.c and
I'd like to know if anyone else has seen these.

The specific message comes out of ffs_alloc.c at line 1358:

start = 0, len = 2, fs = /tmp
panic: ffs_alloccg: map corrupted

Now here's the interesting thing. The system in question is running
lots of news and mail and creating lots of files all day long, but it
only seems to get this panic when an interactive user (me, coz I'm the
only one) is using it.

Normally /tmp is an mfs but I get the same error when it's part of the
root file system.

sup date isn't especially relevant as I tried to upgrade to 1.0A about
a month ago and I got the same error then (but at that time I reverted

Some details about the machine:

486/50 16M
EISA BT747 controller
ST13200 scsi disk

As part of the process of elimination the old file systems were
gradually converted to the new fs but the error persisted.

The panic seems to occur at the time that a file is created (funny
that), but as I said inn is creating files every couple of seconds and
if I don't use it interactively, it stays up for days. If I create
files it crashes within about 5 minutes.

It doesn't occur all the time, or on every file create, just some file
creations. Sending mail (ultimately via sendmail) or saving within
emacs seems to exacerbate it, so *maybe* they are doing unusual system
calls or ioctls or some such. Dunno. The pattern isn't strong enough
for me to hunt that far yet (and I'm kinda trying to avoid actions
that give me patterns...).

We have two other systems running kernels built from the same sources
and they work just fine. But they are different configs without a BT
controller so I'm vaguely suspicious of that.

So, can anyone tell me where to look next? Or what I can do to narrow
the problem down a bit? What other info should I say at this stage?