Re: [dm-devel] Thin provisioning bug in interface

[Mikulas Patocka <mpatocka redhat com>]

On Mon, 19 Sep 2011, Alasdair G Kergon wrote:

> On Mon, Sep 19, 2011 at 12:59:42PM -0400, Mikulas Patocka wrote:
> > if you destroy the pool target (reload it with empty table or something 
> > like that) --- the pool structure can't be freed from memory (because a 
> > thin device is open) and it is still active. 
> 
> You shouldn't be able to destroy the pool target while it is in use.
> (When I last looked at it a few weeks ago, I thought the target line
> parameters were OK, but just that we'd not fixed every possible usage
> sequence/handover yet.)

I am just concerned that this is bloating dm core with more code. 
dm-get-md and singleton is already a bloat (it exposes something that 
wasn't expected to be exposed to the targets) and now you need to add more 
bloat to prevent a cresh when the user reloads 'pool' table without pool 
target.

If you designed it just like the old snapshots, there would be no need for 
any dm core change.

Mikulas

> Alasdair
>