[dm-devel] dm-crypt: add mapping table option to allowing discard requests

[Mike Snitzer]

On Thu, Jul 14 2011 at  8:56pm -0400,
Jeff Cook <jeff at deserettechnology.com> wrote:

> On 07/14/2011 05:56 AM, Milan Broz wrote:
> > Add optional parameter field to dmcrypt table and support
> > "allow_discards" option.
> > 
> > Discard requests bypass crypt queue processing, bio
> > request is simple remapped to underlying device.
> > 
> > Note that discard will be never enabled by default because
> > of security consequences, it is up to administrator
> > to enable it for encrypted devices.
> > 
> > (Note that userspace cryptsetup will not understand new
> > optional parameters yet, support for this will come later.)
> > 
> > Signed-off-by: Milan Broz <mbroz at redhat.com>
> > [snip]
> 
> Thanks very much for this patch Milan. I will try compiling it shortly
> and see where things go -- are you expecting this to be submitted for
> inclusion in mainline soon?

It is already staged for linux-next (and upstream inclusion when the 3.1
merge window opens):
ftp://sources.redhat.com/pub/dm/patches/2.6-unstable/editing/patches/dm-crypt-optionally-support-discard-requests.patch

NOTE: this version of the patch depends on additional changes that were
also staged, e.g.:
ftp://sources.redhat.com/pub/dm/patches/2.6-unstable/editing/patches/dm-table-share-target-argument-parsing-functions.patch