]> pilppa.com Git - linux-2.6-omap-h63xx.git/commit
dm request: extend target interface
authorKiyoshi Ueda <k-ueda@ct.jp.nec.com>
Tue, 6 Jan 2009 03:05:07 +0000 (03:05 +0000)
committerAlasdair G Kergon <agk@redhat.com>
Tue, 6 Jan 2009 03:05:07 +0000 (03:05 +0000)
commit7d76345da6ed3927c9cbf5d3f7a7021e8bba7374
treed0b470dd1a55dfffb27ffa012e4a5afebd133495
parent8fbf26ad5b16ad3a826ca7fe3e86700420abed1f
dm request: extend target interface

This patch adds the following target interfaces for request-based dm.

  map_rq    : for mapping a request

  rq_end_io : for finishing a request

  busy      : for avoiding performance regression from bio-based dm.
              Target can tell dm core not to map requests now, and
              that may help requests in the block layer queue to be
              bigger by I/O merging.
              In bio-based dm, this behavior is done by device
              drivers managing the block layer queue.
              But in request-based dm, dm core has to do that
              since dm core manages the block layer queue.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
include/linux/device-mapper.h