[dm-devel] reinstate dm target local ioctl support

[Alasdair G Kergon]

On Thu, Jan 28, 2016 at 01:50:19PM +0000, Andy Whitcroft wrote:
> However this also removed the possibility of a dm target having target
> specific ioctls.  Currently this is not used by any in-tree targets but
> was utilised by the flashcache out-of-tree module.
 
What data is being passed in and out?

The method we support is passing it through DM_TARGET_MSG (as text).
For examples look at dm-switch.c and dm-stats.c, which handled
pretty large quantities of data.

Would that work?

Alasdair