I am using XFS filesystem & ACL (setfacl/getfacl). I can set ACL entries only for 21 users per one directory. For the 22nd user it shows invalid argument.
Has somebody the same problem? I need to override this limit.
I believe that ACLS are implemented on top of XFS extended attributes (EAs) which are name,value pairs. Name has a limit <= 254 characters. Is this your problem?