[PATCHv4] blk: Replace SG_GAPGS with new queue limits mask

[Busch, Keith]

Hi,

Can this be applied for 4.3?


> On Tue, Aug 04, 2015 at 01:32:13PM -0600, Keith Busch wrote:
> > The SG_GAPS queue flag caused checks for bio vector alignment against
> > PAGE_SIZE, but the device may have different constraints. This patch
> > adds a queue limits so a driver with such constraints can set to allow
> > requests that would have been unnecessarily split. The new gaps check
> > takes the request_queue as a parameter to simplify the logic around
> > invoking this function.
> >
> > This new limit makes the queue flag redundant, so removing it and
> > all usage. Device-mappers will inherit the correct settings through
> > blk_stack_limits().
> >
> > Signed-off-by: Keith Busch <keith.busch at intel.com>
> 
> Looks good,
> 
> Reviewed-by: Christoph Hellwig <hch at lst.de>