Re: [PATCH alternative 2] block: fix the REQ_OP_SECURE_ERASE handling to not leak erased data

[Christoph Hellwig]

On Thu, Mar 17, 2022 at 10:44:01AM +0100, Ulf Hansson wrote:
> Stating that it can't work is probably not a correct statement.
> Certainly it can, but it depends on how "secure" (or clever) the
> implementation of the FTL is in the flash media. I mean, nothing
> prevents the FTL from doing a real erase on erase block level and
> simply let the "secure erase" request wait on that operation to be
> completed.

Well, that assumes it can find all the previous copied of the data.
Having worked with various higher end SSDs FTLs I know they can't,
so if an eMMC device could that would very much surpise me given
the overhead.