Softupdate/kernel panic ffs_fsync

[Sven Willenberger]

Once upon a time I wrote:

> I have seen a few (unresolved) questions similar to this searching
> (google|archives). On a 5.2.1-Release-P2 system (actually a couple with
> essentially identical configs) I get the following Stack Backtrace
> messages:
> 
> backtrace(c070cbf8,2,e5b3af60,0,22) at backtrace +0x17
> getdirtybuf(f7f99bbc,0,1,e5b3a,f60,1) at getdirtybuf +0x30
> flush_deplist(c724e64c,1,f7f99be4,f7f99be8,0) at flush_deplist +0x43
> flush_inode_deps(c6c35000,5c108,f7f99c10,c0510fe3,f7f99c40) at
> flush_inode_deps + 0xa3
> softdep_sync_metadata(f7f99ca8,0,c06da90f,124,0) at
> softdep_sync_metadata +0x87
> ffs_fsync(f7f99ca8,0,c06d0c8b,beb,0) at ffs_fsync +0x3b9
> fsync(c7c224780,f7f99d14,c06e15c0,3ee,1) at fsync +0x151
> syscall(80e002f,bfbf002f,bfbf0028,0,80f57e0) at syscall +0x2a0
> Xint0x80_syscall() at Xint0x80_syscall() +0x1d
> --- syscall (95), eip=0x282a89af, esp=0xbfbfa10c, ebp=0xbfbfba68 ---
> 
> 
> The systems in question are mail servers that act as gateways (no local
> delivery) running mimedefang (2.39 - 2.42) with spamassassin. The work
> directory is not swap/memory mounted but rather on
> /var/spool/MIMEDefang. The frequency of these messages increases when
> bayes filtering is added (as the bayes tokens db file also resides on
> the same filesystem/directory).
> 
> I have read that it may be that getdirtybuf() was passed a corrupt
> buffer header; has anything further ever been made of this and if not,
> where/how do I start to help contributing to finding a solution?

I have yet to see a resolution to this issue. I am now running all the
boxen using 5.2.1-Release-P8 with perl 5.8.4 and all ports upgraded.

I have created 256MB Ramdisks on each machine that MIMEDefang now uses
for it's temp files and bayesian database but, if anything, the
frequency of backtraces has actually increased, rather than decreased.

What do I need to do to further delineate this issue? For me this is a
showstopper as it will occasionally cause a panic/reboot. I have these
machines clustered so as not to interrupt services but it is slowly
becoming frustrating as the machines are bailing under heavy traffic.
Is there any output I can provide or diagnostics I can run to help find
a solution?

Sven