nfs hang

Hi,

I have setup nfsd in a jail. It exports zfs fs. The kernel is 16-CURRENT/aarch64. Jails are 14.3-RELEASE.
$ cat /data/jails/pkg/_root/etc/exports
V4:	/	-sec=sys

/usr/local/poudriere/data/logs/bulk	-sec=sys -maproot=root
/usr/local/poudriere/data/packages	-sec=sys -maproot=root

/usr/ports	-sec=sys


The clients run poudriere in jails.

Now and than I get hanging processes and unresponsive nfs server messages.

All NFS threads are in this state:
[root@rpi4 ~]# procstat -kk 5973
   PID    TID COMM                TDNAME              KSTACK
  5973 100541 nfsd                nfsd: master        mi_switch+0x100 sleepq_catch_signals+0x3e4 sleepq_timedwait_sig+0x18 _sleep+0x1a0 clnt_vc_call+0x814 clnt_reconnect_call+0x960 newnfs_request+0xacc nfsrpc_closerpc+0xfc nfscl_tryclose+0x58 nfsrpc_doclose+0x294 nfscl_doclose+0x390 nfsrpc_close+0x28 ncl_inactive+0x14c vop_sigdefer+0x34 vinactivef+0xb8 vput_final+0x1f4 null_reclaim+0x1a0 VOP_RECLAIM_APV+0x20
  5973 100784 nfsd                nfsd: service       mi_switch+0x100 sleepq_catch_signals+0x3e4 sleepq_timedwait_sig+0x18 _sleep+0x1a0 clnt_vc_call+0x814 clnt_reconnect_call+0x960 newnfs_request+0xacc nfsrpc_closerpc+0xfc nfscl_tryclose+0x58 nfsrpc_doclose+0x294 nfscl_doclose+0x390 nfsrpc_close+0x28 ncl_inactive+0x14c vop_sigdefer+0x34 vinactivef+0xb8 vput_final+0x1f4 null_reclaim+0x1a0 VOP_RECLAIM_APV+0x20
  5973 100785 nfsd                nfsd: service       mi_switch+0x100 sleepq_catch_signals+0x3e4 sleepq_timedwait_sig+0x18 _sleep+0x1a0 clnt_vc_call+0x814 clnt_reconnect_call+0x960 newnfs_request+0xacc nfsrpc_closerpc+0xfc nfscl_tryclose+0x58 nfsrpc_doclose+0x294 nfscl_doclose+0x390 nfsrpc_close+0x28 ncl_inactive+0x14c vop_sigdefer+0x34 vinactivef+0xb8 vput_final+0x1f4 null_reclaim+0x1a0 VOP_RECLAIM_APV+0x20
  5973 100786 nfsd                nfsd: service       mi_switch+0x100 sleepq_catch_signals+0x3e4 sleepq_timedwait_sig+0x18 _sleep+0x1a0 clnt_vc_call+0x814 clnt_reconnect_call+0x960 newnfs_request+0xacc nfsrpc_closerpc+0xfc nfscl_tryclose+0x58 nfsrpc_doclose+0x294 nfscl_doclose+0x390 nfsrpc_close+0x28 ncl_inactive+0x14c vop_sigdefer+0x34 vinactivef+0xb8 vput_final+0x1f4 null_reclaim+0x1a0 VOP_RECLAIM_APV+0x20
... and a couple more similar lines ...

In rc.conf:
nfs_server_enable=YES
mountd_enable=YES
nfsv4_server_only=YES
nfs_server_flags="-t"

The filesystems are a zfs legacy mount in the jail:
# grep zfs /data/jails/pkg/fstab
zrpi4/data/poudriere-logs-bulk	/data/jails/pkg/_root/usr/local/poudriere/data/logs/bulk	zfs	rw	0	0
zrpi4/data/poudriere-packages	/data/jails/pkg/_root/usr/local/poudriere/data/packages	zfs	rw	0	0
zdata4/ports	/data/jails/pkg/_root/usr/ports	zfs	rw	0	0


Interestingly I also have a bash process hanging which should not access NFS at the moment:
# procstat -kk 83175
   PID    TID COMM                TDNAME              KSTACK
83175 111203 bash                -                   mi_switch+0x100 sleeplk+0xf8 lockmgr_slock_hard+0x29c _vn_lock+0x50 vget_finish+0x28 cache_fplookup_final_child+0x54 cache_fplookup+0x538 namei+0xd8 kern_statat+0xd4 sys_fstatat+0x2c do_el0_sync+0x6b4 handle_el0_sync+0x4c

Any thoughts?

Regards,
Ronald.