Re: zero out blocks of freed user data for operation a virtual machine environment

Goswin von Brederlow
2009-05-25T13:14:02Z

Thomas Glanzmann <thomas@glanzmann.de> writes:

> Hello Ted,
>
>> Yes, it does, sb_issue_discard(). So if you wanted to hook into this
>> routine with a function which issued calls to zero out blocks, it
>> would be easy to create a private patch.
>
> that sounds good because it wouldn't only target the most used
> filesystem but every other filesystem that uses the interface as well.
> Do you think that a tunable or configurable patch has a chance to hit
> upstream as well?
>
> Thomas

I could imagine a device mapper target that eats TRIM commands and
writes out zeroes instead. That should be easy to maintain outside or
inside the upstream kernel source.

MfG
Goswin