NFS 4.2 mount not working properly

Start by reproducing the supplied mount and file-access commands on kernel 5.15.32-v7+ and 5.10.95-v7+, comparing NFS minor versions 0, 1, and 2. Inspect kernel logs and the NFS-related kernel paths involved in the hang; done means NFS 4.2 mounts allow file access without the process hanging.

Describe the bug

Mounting an external NFS server which is running on version 4.2 results in an hanging process if one tries to access file from the NFS server.
This problem occurs for kernel 5.15.32-v7+, whereas using the same mounting commands work properly on kernel 5.10.95-v7+
Specifying the NFS version as an option in the mount command is working, but only for -o nfsvers=4,minorversion=0 or -o nfsvers=4 ommitting the minor version. Minorversion 1 and 2 result in the hanging process, as soon as one trys to access mounted files.

The problem was discussed in https://dietpi.com/phpbb/viewtopic.php?t=10238 earlier

Steps to reproduce the behaviour

Working case:

root@pi2udhifi:# umount /mnt/nfs
root@pi2udhifi:# mount -t nfs -o "nfsvers=4,minorversion=0" 192.168.16.32:/ /mnt/nfs/
root@pi2udhifi:# df -h
Dateisystem Größe Benutzt Verf. Verw% Eingehängt auf
/dev/root 60G 8,1G 49G 15% /
devtmpfs 430M 0 430M 0% /dev
tmpfs 462M 0 462M 0% /dev/shm
tmpfs 185M 7,6M 178M 5% /run
tmpfs 5,0M 8,0K 5,0M 1% /run/lock
tmpfs 1,0G 8,0K 1,0G 1% /tmp
/dev/mmcblk0p1 127M 52M 75M 41% /boot
tmpfs 93M 8,0K 93M 1% /run/user/0
tmpfs 93M 12K 93M 1% /run/user/1000
tmpfs 50M 8,0K 50M 1% /var/log
192.168.16.32:/ 16M 0 16M 0% /mnt/nfs
root@pi2udhifi:# ls -la /mnt/nfs/nfs
insgesamt 256
drwxrwxrwx 10 root root 4096 2. Mär 12:04 .
drwxrwxrwt 3 root root 60 7. Apr 10:02 ..
-rw-rw-rw- 1 root root 227512 2. Mär 11:37 Alarm.mp3
drwxr-xr-x 3 root root 4096 19. Feb 2021 dietpi-backup
drwxrwxr-x 9 dietpi dietpi 4096 27. Sep 2021 dietpi-sync
drwx------ 7 root root 4096 3. Jan 11:44 ha-repo
drwxrwxrwx 2 root root 4096 27. Mär 15:10 @Recycle
drwxrwxrwx 2 root root 4096 2. Mär 12:04 .@__thumb
drwxr-xr-x 3 root root 4096 2. Feb 10:08 tmp
drwx------ 7 root root 4096 3. Jan 14:11 wp-repo
root@pi2udhifi:# df -h
Dateisystem Größe Benutzt Verf. Verw% Eingehängt auf
/dev/root 60G 8,1G 49G 15% /
devtmpfs 430M 0 430M 0% /dev
tmpfs 462M 0 462M 0% /dev/shm
tmpfs 185M 7,6M 178M 5% /run
tmpfs 5,0M 8,0K 5,0M 1% /run/lock
tmpfs 1,0G 8,0K 1,0G 1% /tmp
/dev/mmcblk0p1 127M 52M 75M 41% /boot
tmpfs 93M 8,0K 93M 1% /run/user/0
tmpfs 93M 12K 93M 1% /run/user/1000
tmpfs 50M 8,0K 50M 1% /var/log
192.168.16.32:/ 16M 0 16M 0% /mnt/nfs
192.168.16.32:/nfs 64G 16G 48G 25% /mnt/nfs/nfs
root@pi2udhifi:#

Not working case:
root@pi2udhifi:# umount /mnt/nfs
root@pi2udhifi:# df -h
Dateisystem Größe Benutzt Verf. Verw% Eingehängt auf
/dev/root 60G 8,1G 49G 15% /
devtmpfs 430M 0 430M 0% /dev
tmpfs 462M 0 462M 0% /dev/shm
tmpfs 185M 7,6M 178M 5% /run
tmpfs 5,0M 8,0K 5,0M 1% /run/lock
tmpfs 1,0G 8,0K 1,0G 1% /tmp
/dev/mmcblk0p1 127M 52M 75M 41% /boot
tmpfs 93M 8,0K 93M 1% /run/user/0
tmpfs 93M 12K 93M 1% /run/user/1000
tmpfs 50M 0 50M 0% /var/log
root@pi2udhifi:# mount -t nfs -o "nfsvers=4,minorversion=2" 192.168.16.32:/ /mnt/nfs/
root@pi2udhifi:# df -h
Dateisystem Größe Benutzt Verf. Verw% Eingehängt auf
/dev/root 60G 8,1G 49G 15% /
devtmpfs 430M 0 430M 0% /dev
tmpfs 462M 0 462M 0% /dev/shm
tmpfs 185M 7,6M 178M 5% /run
tmpfs 5,0M 8,0K 5,0M 1% /run/lock
tmpfs 1,0G 8,0K 1,0G 1% /tmp
/dev/mmcblk0p1 127M 52M 75M 41% /boot
tmpfs 93M 8,0K 93M 1% /run/user/0
tmpfs 93M 12K 93M 1% /run/user/1000
tmpfs 50M 0 50M 0% /var/log
192.168.16.32:/ 16M 0 16M 0% /mnt/nfs
root@pi2udhifi:~# ls -la /mnt/nfs/nfs

^C <-----process hangs forever
root@pi2udhifi:~#

Device (s)

Raspberry Pi 2 Mod. B v1.2

System

root@pi2udhifi:/etc# vcgencmd version
Mar 24 2022 13:20:54
Copyright (c) 2012 Broadcom
version e5a963efa66a1974127860b42e913d2374139ff5 (clean) (release) (start)

root@pi2udhifi:/etc# uname -a
Linux pi2udhifi 5.15.32-v7+ #1538 SMP Thu Mar 31 19:38:48 BST 2022 armv7l GNU/Linux
root@pi2udhifi:/etc#

root@pi2udhifi:/etc# cat os-release
PRETTY_NAME="Debian GNU/Linux 11 (bullseye)"
NAME="Debian GNU/Linux"
VERSION_ID="11"
VERSION="11 (bullseye)"
VERSION_CODENAME=bullseye
ID=debian
HOME_URL="https://www.debian.org/"
SUPPORT_URL="https://www.debian.org/support"
BUG_REPORT_URL="https://bugs.debian.org/"
root@pi2udhifi:/etc#

Logs

No response

Additional context

No response