Note: This is left here for historical reasons, but this information is now mostly obsolete.
You have to mount the filesystem with acls. If it is unmounted you can set it in the superblock with tunefs -a.
FreeBSD does not support GNU/Linux Extended User Attributes so you should configure with --disable-user-attributes (though configure should disable them if it is not being run in GNU/Linux).
Following are the options you have to enable in File System to have ACL support in the several filesystems that Linux supports.
<*> Second extended fs support [*] Ext2 POSIX Access Control Lists
You have to mount the filesystem with acl option if you want ACL support. You have to mount the filesystem with user_xattr if you want extended user attributes. Consult the mount(8) manual.
<*> Ext3 journalling file system support [*] Ext3 extended attributes [*] Ext3 POSIX Access Control Lists
You have to mount the filesystem with acl option if you want ACL support. You have to mount the filesystem with user_xattr if you want extended user attributes. Consult the mount(8) manual.
<*> Reiserfs support [*] ReiserFS extended attributes [*] ReiserFS POSIX Access Control Lists
It is not necessary to enable any special option in ReiserFS. This filesystem supports both ACL and extended user attributes.
<*> JFS filesystem support [*] JFS POSIX Access Control Lists
It is not necessary to enable any special option in JFS. This filesystem supports both ACL and extended user attributes.
<*> XFS filesystem support [*] POSIX ACL support
It is not necessary to enable any special option in XFS. This filesystem supports both ACL and extended user attributes.
<*> NFS file system support [*] Provide NFSv3 client support [*] Provide client support for the NFSv3 ACL protocol extension
This filesystem only supports ACL. The exported filesystem must have ACL turned on. The imported filesystem must have ACL turned on with acl. Consult mount(8) manual.
CIFS is supported in Samba 3 and Windows 2000. Note that this is still regarded as experimental.
<*> CIFS support (advanced network filesystem for Samba, Windows and other CIFS compliant servers) [*] CIFS extended attributes (EXPERIMENTAL) [*] CIFS POSIX Extensions (EXPERIMENTAL)