bug#20884: copying NFS4 ACLs portably

[Andreas Grünbacher]

2015-06-23 20:43 GMT+02:00 Michael Stone <address@hidden>:
> Well, moving things around on an NFSv4 filesystem is the request I received,
> not converting the ACL from NFSv4 to POSIX. :) I'm not convinced that it's
> possible to transparently map arbitrary ACLs from one filesystem to another
> given different semantics, so I'm not sure that's a goal worth holding up
> the ability to copy NFS4 ACLs indefinitely. Other implementations just warn
> when they can't preserve ACLs, which seems reasonable.

I'm not talking about converting between NFSv4 and POSIX ACLs, I'm thinking
of optionally having local NFSv4 ACL support on Linux on select file systems,
like Solaris has on ZFS.

Support for the "system.nfs4_acl" attribute could be added to gnulib; it's not
that big a deal, especially since the acl handling cleanup. I'm not
going to write
that code though.

> The current situation seems pretty bad, in that something is happening that
> seems to be almost-working, but which shouldn't be working at all. It's double
> bad that the behavior of coreutils depends on a config file
> (/etc/xattr.conf) which almost no distributions include by default.
> And if we start to include it, then something that people are currently using 
> to
> copy NFS4 ACLs stops working (without any changes in coreutils).

Agreed, it's a mess.

Andreas