UFS lockups

[Sławek Żak]

I observe UFS lockups under heavy I/O. To reproduce the problem run around
10 copies of cp -Rp /usr/some-random-dir. All cp's after some time are hanging
on getblk. du's running concurrently are hanging in ufs state. The filesystems
are UFS2. The Server is running 5.2-BETA on SMP Dell 2650. Filesystems are laid
on Adaptec RAID controller (aac). Any ideas how to trace the problem?

/S