Public bug reported: Step to reproduse:
- Crete dircetory with other directories and files. - Chown some files in this directory, set any non-root permissions. - Export nfs share with 'ro' permissions. - Mount nfs share. - Mount ovrelayfs with nfs as lowerdir - Try to read theese non-root files or directories: Example for overlay mount: # ls -l /var/lib/libvirt total 16 drwx--x--x 2 root root 4096 Oct 10 07:33 boot drwx--x--x 2 root root 4096 Oct 10 07:33 images drwxr-x--- 3 libvirt-qemu kvm 4096 Jan 11 21:49 qemu drwx------ 2 root root 4096 Oct 10 07:33 sanlock # ls -l /var/lib/libvirt/qemu/ ls: cannot open directory '/var/lib/libvirt/qemu/': Operation not supported And for nfs mount: # ls -l /rofs/var/lib/libvirt total 16 drwx--x--x 2 root root 4096 Oct 10 07:33 boot drwx--x--x 2 root root 4096 Oct 10 07:33 images drwxr-x--- 3 libvirt-qemu kvm 4096 Jan 11 21:49 qemu drwx------ 2 root root 4096 Oct 10 07:33 sanlock # ls -l /rofs/var/lib/libvirt/qemu/ total 4 drwxr-xr-x 3 root root 4096 Jan 11 21:49 channel If I reset permission, it helps: # chown libvirt-qemu:kvm /var/lib/libvirt/qemu # ls -l /var/lib/libvirt/qemu/ total 4 drwxr-xr-x 3 root root 4096 Jan 11 21:49 channel My mounts (from /proc/mounts) 192.168.101.61:/data/opt/ltsp/amd64 /rofs nfs ro,relatime,vers=3,rsize=1048576,wsize=1048576,namlen=255,hard,nolock,proto=tcp,port=2049,timeo=7,retrans=10,sec=sys,local_lock=all,addr=192.168.101.61 0 0 overlay / overlay rw,relatime,lowerdir=/rofs,upperdir=/cow/up,workdir=/cow/work 0 0 I tested it nfs3 and nfs4 mount, with this kenels: # uname -a Linux controller03 4.4.0-62-generic #83-Ubuntu SMP Wed Jan 18 14:10:15 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux # uname -a Linux m1c18n1 4.8.0-36-generic #36~16.04.1-Ubuntu SMP Sun Feb 5 09:39:57 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux ** Affects: linux (Ubuntu) Importance: Undecided Status: Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1665921 Title: OverlayFS with readonly NFS lower layer. Operation not supported for non-root files. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1665921/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs