Re: [PATCH hotfix 6.12] maple_tree: correct tree corruption on spanning store

[Lorenzo Stoakes]

On Sat, Oct 05, 2024 at 07:41:14AM +0100, Lorenzo Stoakes wrote:
> Writing a data range into a maple tree may involve overwriting a number of
> existing entries that span across more than one node. Doing so invokes a
> 'spanning' store.
>

[snip]

Andrew - just to note that I have intentionally left stable off this, in
order that wre can allow this to stabilise in the 6.12 release candidates.

Up until 6.12 this bug seemed much harder to hit, and as far as I'm aware
we've never had a bug report for it prior to this.

I am confident in the patch for 6.12 as all of the (_numerous_) maple tree
userland tests pass and the kernel is stable with it, but as this is a
such a subtle algorithmic change I think we should be cautious.

As soon as things settle down I will ping stable to get it backported.

Thanks!