Re: panic: nfsv4root ref cnt cpuid = 1

On Sun, Sep 22, 2024 at 10:17 AM J David <j.david.lists@gmail.com> wrote:
> #8 0xffffffff8302c3a7 at null_lookup+0xc7

After noticing null_lookup in the crash trace, I realized that this
must be an nfs filesystem that is then remounted elsewhere via nullfs.
We've eliminated most of those.

There's only one filesystem that is still used with nullfs
(specifically to avoid a large number of otherwise identical mounts).
Here are the "nfsstat -m" mount flags for that filesystem:

nfsv4,minorversion=2,oneopenown,tcp,resvport,nconnect=1,hard,cto,nolockd,sec=sys,acdirmin=3,acdirmax=60,acregmin=5,acregmax=60,nametimeo=60,negnametimeo=60,rsize=65536,wsize=65536,readdirsize=65536,readahead=1,wcommitsize=16777216,timeout=120,retrans=2147483647

The server of this filesystem is 14.1-RELEASE-p5 and the exported
filesystem is a readonly ZFS dataset.

Thanks!