I'm not perfectly sure if this is a bug or a feature. If it's a feature: sorry for the noise.

I found some behavior of nfsv4 using no_root_quash: it only works with exported directories exported as bind mounts, but not for "real" directories.

E. g., I use the following exports:

    # cat /etc/exports 
    /srv/nfs        192.168.178.0/24(rw,fsid=0,no_subtree_check) 
    /srv/nfs/1      192.168.178.0/24(rw,no_root_squash,no_subtree_check) 
    /srv/nfs/2      192.168.178.0/24(rw,no_root_squash,no_subtree_check)

after mounting them ...

    # mkdir /mnt/1 /mnt/2 
    # mount.nfs4 skoni:/1 /mnt/1 -o rw,vers=4,_netdev 
    # mount.nfs4 skoni:/2 /mnt/2 -o rw,vers=4,_netdev

... they look identical ...

# mount | grep mnt 
    skoni:/1 on /mnt/1 type nfs4 (rw,vers=4,addr=192.168.178.80,clientaddr=192.168.178.80,_netdev) 
    skoni:/2 on /mnt/2 type nfs4 (rw,vers=4,addr=192.168.178.80,clientaddr=192.168.178.80,_netdev)

... but I have only root write access to the first one:

    # touch /mnt/1/foo 
    # touch /mnt/2/foo 
    touch: cannot touch '/mnt/2/foo': Permission denied

The only difference is that mount 1 is a bind mount and mount 2 is a normal directory:

    # mount | grep /srv 
    /var/tmp/1 on /srv/nfs/1 type none (rw,bind)

Is this intended behavior or is this a bug?