• Jens Axboe's avatar
    blk-mq: don't disallow request merges for req->special being set · e7e24500
    Jens Axboe authored
    For blk-mq, if a driver has requested per-request payload data
    to carry command structures, they are stuffed into req->special.
    For an old style request based driver, req->special is used
    for the same purpose but indicates that a per-driver request
    structure has been prepared for the request already. So for the
    old style driver, we do not merge such requests.
    As most/all blk-mq drivers will use the payload feature, and
    since we have no problem merging on these, make this check
    dependent on whether it's a blk-mq enabled driver or not.
    Reported-by: default avatarShaohua Li <shli@fusionio.com>
    Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
blk-merge.c 13.1 KB