• Mike Snitzer's avatar
    dm mpath: add optional "queue_mode" feature · e83068a5
    Mike Snitzer authored
    Allow a user to specify an optional feature 'queue_mode <mode>' where
    <mode> may be "bio", "rq" or "mq" -- which corresponds to bio-based,
    request_fn rq-based, and blk-mq rq-based respectively.
    If the queue_mode feature isn't specified the default for the
    "multipath" target is still "rq" but if dm_mod.use_blk_mq is set to Y
    it'll default to mode "mq".
    This new queue_mode feature introduces the ability for each multipath
    device to have its own queue_mode (whereas before this feature all
    multipath devices effectively had to have the same queue_mode).
    This commit also goes a long way to eliminate the awkward (ab)use of
    DM_TYPE_*, the associated filter_md_type() and other relatively fragile
    and difficult to maintain code.
    Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
dm-rq.h 1.57 KB