del@thrush.mlb.semi.harris.com (Don Lewis) (08/01/90)
This problem just bit me again, so I did some digging and it looks like I found a bug. The problem is that I am unable to unmount an nfs filesystem on a client machine. Umount tells me that the filesystem is busy, but ofiles does not find any processes referencing the filesystem. I wrote a program to snoop around in /dev/kmem, and I found that the mi_refct field in the mntinfo structure for the the filesystem appears to be corrupted. The other nfs mounts have small postive reference counts, but this one has a reference count of -9602! There is another nfs mount with a negative reference count (-2921) that is also unmountable. What is interesting is that there have been nfs write errors to both servers since the client was last booted. In one case the problem was a stale file handle, in the other case the partition was full. I am not able to reproduce the corrupted reference counts by causing these types of write errors on purpose. The client is a Sun 4/280 running 4.0.3. The two servers are a Sun 3/60 running 4.0.3 and a Sun 386i running 4.0.2. Both the 4/280 and the 3/60 are using the NFS confused file patch. Don "Truck" Lewis Harris Semiconductor Internet: del@mlb.semi.harris.com PO Box 883 MS 62A-028 Phone: (407) 729-5205 Melbourne, FL 32901