[dm-devel] [PATCH 05/16] dm: always defer request allocation to the owner of the request_queue

[Hannes Reinecke]

On 01/23/2017 04:29 PM, Christoph Hellwig wrote:
> DM already calls blk_mq_alloc_request on the request_queue of the
> underlying device if it is a blk-mq device.  But now that we allow drivers
> to allocate additional data and initialize it ahead of time we need to do
> the same for all drivers.   Doing so and using the new cmd_size
> infrastructure in the block layer greatly simplifies the dm-rq and mpath
> code, and should also make arbitrary combinations of SQ and MQ devices
> with SQ or MQ device mapper tables easily possible as a further step.
> 
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> ---
>  drivers/md/dm-core.h          |   1 -
>  drivers/md/dm-mpath.c         | 132 ++++------------------
>  drivers/md/dm-rq.c            | 251 ++++++++++--------------------------------
>  drivers/md/dm-rq.h            |   2 +-
>  drivers/md/dm-target.c        |   7 --
>  drivers/md/dm.c               |  18 +--
>  drivers/md/dm.h               |   3 +-
>  include/linux/device-mapper.h |   3 -
>  8 files changed, 81 insertions(+), 336 deletions(-)
> 
Reviewed-by: Hannes Reinecke <hare at suse.com>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		   Teamlead Storage & Networking
hare at suse.de			               +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)