Just noticed that ACL mapping from POSIX ACLs to NFSv4 ACLs (which are somewhat similar to CIFS ones) seems to have just been added to the Linux kernel http://www.citi.umich.edu/u/marius/draft-eriksen-nfsv4-acl-02.txt And the code at: http://linux.bkbits.net:8080/linux-2.5/cset@1.1803.100.180?nav=index. html|src/|src/fs|related/fs/Kconfig