Re: [PATCH v11 21/48] ext4: Add richacl feature flag

On Fri, Oct 16, 2015 at 7:31 PM, Austin S Hemmelgarn
[off-list ref] wrote:

I would like to re-iterate, on both XFS and ext4, I _really_ think this
should be a ro_compat flag, and not an incompat one.  If a person has the
ability to mount the FS (even if it's a read-only mount), then they by
definition have read access to the file or partition that the filesystem is
contained in, which means that any ACL's stored on the filesystem are
functionally irrelevant,

It is unfortunately not safe to make such a file system accessible to
other users, so the feature is not strictly read-only compatible.

Andreas