Re: [PATCH v2] drivers/base/node.c: Simplify unregister_memory_block_under_nodes()

[Andrew Morton]

On Wed, 27 Nov 2019 17:53:12 +0100 David Hildenbrand <david@xxxxxxxxxx> wrote:

> Just a note that this was actually also a bugfix as noted by Chris.
> 
> If the memory we are removing was never onlined,
> get_nid_for_pfn()->pfn_to_nid() will return garbage. Removing will
> succeed but links will remain in place.
> 
> Can be triggered by
> 
> 1. hotplugging a DIMM to node 1
> 2. not onlining the memory blocks
> 3. unplugging it
> 4. re-plugging it to node 1
> 
> We will trigger the BUG_ON(ret) in add_memory_resource(), because
> link_mem_sections() will return with -EEXIST.

Oh.  In that case case we please redo the patch as a bugfix? 
Appropriate title and changelog?  And perhaps the bugfix can be split
from the cleanup, to make the former more backportable?