Recent changes to autorid (was Re: [SCM] Samba Shared Repository - branch master updated)

[Simo]

On Wed, 2014-04-30 at 14:38 +0200, Mathias Dietz wrote:
> Hi Michael, Jeremy, 
> 
> I'm concerned about the proposal of having fixed ids for well-knowns 
> because it has a high potential to break existing customer setups. 
> Even though having fixed ids for well-knows sounds appealing, you can not 
> guarantee that they do not conflict with existing users on the system.

I think the proposal form Jeremy is more nuanced.

As far as I understood it the idea is to propose *default* wellknown
mappings for wellknown SIDs.
However should those conflict with pre-existing setups then samba would
stop and tell the admin how to manually map all those sids in idmap.

The idea is not to hardcode the mappings, but to preset them in an idmap
table.

> We use Samba with autorid for many customer installations and it happens 
> often that there are existing NFS ids which can not be changed easliy.
> A full file system traversal would be needed to replace conflicting ids in 
> the acls. Even worse, if conflicting NFSv3 users exists you would have to 
> change all the clients as well. In combination with SFU or NIS the 
> externally store ids would need to be changed as well.
> 
> This will scare some customers and lead to upgrade problems.
> Michaels initials proposal sounds more flexible and would not lead to such 
> problems. 

See the above, remapping of those IDs will always be possible, it is
just that it should be an exception and not the rule.

Simo.