Re: [dm-devel] Snapshots

[Phillip Susi <psusi cfl rr com>]

Jun'ichi Nomura wrote:
> So, you have to put the linear mapping *before* that.
> Then, the top-level block device will be locked but you can
> still change the underlying mappings.

So using a disk device as a dm target locks it.  DM won't use a disk
device as a target if it is locked.  Are you saying that dm can use
another dm device as a target, even if it is already locked by being
used as another dm target?