[dm-devel] [PATCH] dm: introduce DM_GET_TARGET_VERSION

[Christoph Hellwig]

On Mon, Sep 16, 2019 at 05:55:42AM -0400, Mikulas Patocka wrote:
> This patch introduces a new ioctl DM_GET_TARGET_VERSION. It will load a
> target that is specified in the "name" entry in the parameter structure
> and return its version.
> 
> This functionality is intended to be used by cryptsetup, so that it can
> query kernel capabilities before activating the device.

Well, if you want to query kernel features you better ask for a feature
bitmap than a version number, which can be rather meaningless with
the amount of backporting that is going on.