machine is unusable with panic: vrele: negative ref cnt

[Alan Evans]

On boot I see the following on an IBM T30 laptop:

Mounting root from ufs:/dev/ad0s1a
WARNING: / was not properly dismounted
ad0: FAILURE - READ_MUL status=59<READY,DSC,DRQ,ERROR>
error=40<UNCORRECTABLE> LBA=376639
ad0: FAILURE - READ_MUL status=59<READY,DSC,DRQ,ERROR>
error=40<UNCORRECTABLE> LBA=376639
ad0: FAILURE - READ_MUL status=59<READY,DSC,DRQ,ERROR>
error=40<UNCORRECTABLE> LBA=376639
ad0: FAILURE - READ_MUL status=59<READY,DSC,DRQ,ERROR>
error=40<UNCORRECTABLE> LBA=376639
ad0: FAILURE - READ_MUL status=59<READY,DSC,DRQ,ERROR>
error=40<UNCORRECTABLE> LBA=376639
ad0: FAILURE - READ_MUL status=59<READY,DSC,DRQ,ERROR>
error=40<UNCORRECTABLE> LBA=376639
ad0: FAILURE - READ_MUL status=59<READY,DSC,DRQ,ERROR>
error=40<UNCORRECTABLE> LBA=376639
panic: vrele: negative ref cnt

syncing disks, buffers remaining... 9 9 9 9 9 9 9 9 9
9  \giving up on 9 buffers.

And the same occurs on every reboot and the machine
isn't usable anymore. I'd like to salvage the data
that's in the hard disk. Any ideas on how ro recover
data from the hard disk? The disk is only 4 months
old.


Thanks,

Alan Evans