> См., если мне не изменяет склероз, "acl backend".

Изменяет. Это модули VFS:

The vfs_acl_tdb VFS module stores NTFS Access Control Lists (ACLs) in a tdb file. This enables the full mapping of Windows ACLs on Samba servers.

The ACL settings are stored in $LOCKDIR/file_ntacls.tdb.

Please note that this module is experimental!

И для xattr:

The vfs_acl_xattr VFS module stores NTFS Access Control Lists (ACLs) in Extended Attributes (EAs). This enables the full mapping of Windows ACLs on Samba servers.

The ACLs are stored in the Extended Attribute security.NTACL of a file or directory. This Attribute is not listed by getfattr -d filename. To show the current value, the name of the EA must be specified (e.g. getfattr -n security.NTACL filename ).

Please note that this module is experimental!