Re: [PATCH v6 1/5] mm/zone_device: Reinitialize large zone device private folios

Andrew Morton
2026-01-16T22:34:42Z

On Fri, 16 Jan 2026 12:10:16 +0100 Francois Dugast <francois.dugast@intel.com> wrote:

> Reinitialize metadata for large zone device private folios in
> zone_device_page_init prior to creating a higher-order zone device
> private folio. This step is necessary when the folio’s order changes
> dynamically between zone_device_page_init calls to avoid building a
> corrupt folio. As part of the metadata reinitialization, the dev_pagemap
> must be passed in from the caller because the pgmap stored in the folio
> page may have been overwritten with a compound head.
>
> Without this fix, individual pages could have invalid pgmap fields and
> flags (with PG_locked being notably problematic) due to prior different
> order allocations, which can, and will, result in kernel crashes.

Is it OK to leave 6.18.x without this fixed?