Re: [dm-devel] [PATCH 1/2 v3] dm: discard support for the linear target

[Mike Snitzer <snitzer redhat com>]

On Tue, Jun 29 2010 at  1:25am -0400,
Mike Snitzer <snitzer redhat com> wrote:

> Allow discards to be passed through to a single device linear mapping.
> Introduce DM_TARGET_SUPPORTS_DISCARDS target features flag that each
> target must set once discard support is added.
> 
> Verify table's underlying devices support discards prior to setting the
> associated DM device as capable of discards (via QUEUE_FLAG_DISCARD).
> 
> Signed-off-by: Mike Snitzer <snitzer redhat com>

I mistakenly dropped Joe's Reviewed-by after making agk's suggested
(minor) changes for v3:
- invert if..else logic in __clone_and_map_discard
- remove unnecessary uninitialized_var() in dm_table_supports_discards

Reviewed-by: Joe Thornber <thornber redhat com>