Re: [EXT] Re: [PATCH v2 0/2] Optimize secure erase performance for certain Kingston eMMC devices

[Christoph Hellwig]

On Tue, Dec 16, 2025 at 10:02:49AM +0000, Luke Wang wrote:
> In fact, secure erase does not guarantee that data is physically
> erased.

It can't.  Given how Flash storage works there is no way to actually
securely erase data on a per-LBA range basis. 

> And the eMMC 5.1 Spec:
> "NOTE Secure Erase is included for backwards compatibility. New system level implementations
> (based on v4.51 devices and beyond) should use Erase combined with Sanitize instead of secure erase."

And this is 100% correct.  Only a device-level Sanitize operation
can do meaningful erasure of data on Flash based media (or modern
HDDs with all the remapping they do for that matter).