[Virtio-fs] regression: lsetfilecon fails, breaks rpm, dpkg, dnf in virtiofs guests.

[Harry G. Coin]

Some regression in virtio-fs has led to rpm/dnf/yum failing  in the same
guest it previously worked.

linux 5.11.19-300.fc34.x86_64

Specifically, all attempts to use dnf/yum lead to examples similar to this:

Error unpacking rpm package dnf-4.7.0-1.fc34.noarch
  Upgrading        :
python3-dnf-plugins-core-4.0.21-1.fc34.noarch                                                                                                                                                     
8/20
error: unpacking of archive failed on file /usr/bin/dnf;60b1b277: cpio:
(error 0x2)
error: dnf-4.7.0-1.fc34.noarch: install failed
error: lsetfilecon: (/etc/dnf/plugins/copr.conf,
system_u:object_r:etc_t:s0) Operation not permitted
error: Plugin selinux: hook fsm_file_prepare failed

(

For all packages.  No updates are possible.  Possibly related to:
https://github.com/fedora-selinux/selinux-policy/pull/478/files/21a2df26cd605c55de7edc80e16907fcb76ccf08 
?  What really gets me, is this error exists even though

# getenforce
Permissive

)

The host is running btrfs.  ... virtiofsd --fd=50 -o
source=/vmsystems/fedora_generic,xattr,flock,posix_lock

same effect with  .... virtiofsd --fd=36 -o
source=/vmsystems/dbl1,xattr,flock,no_posix_lock

/etc/fstab:

myfs / virtiofs seclabel 0 0