end_io_data
struct blk_rq_wait *wait = rq->end_io_data;
rq->end_io_data = &wait;
rq->end_io_data = NULL;
struct dm_rq_target_io *tio = clone->end_io_data;
struct dm_rq_target_io *tio = clone->end_io_data;
struct dm_rq_target_io *tio = clone->end_io_data;
clone->end_io_data = tio;
struct nvme_ctrl *ctrl = rq->end_io_data;
rq->end_io_data = ctrl;
struct io_uring_cmd *ioucmd = req->end_io_data;
req->end_io_data = ioucmd;
abort_req->end_io_data = NULL;
struct nvme_queue *nvmeq = req->end_io_data;
struct nvme_queue *nvmeq = req->end_io_data;
req->end_io_data = nvmeq;
struct nvmet_req *req = rq->end_io_data;
rq->end_io_data = req;
struct sg_request *srp = rq->end_io_data;
rq->end_io_data = srp;
struct st_request *SRpnt = req->end_io_data;
req->end_io_data = SRpnt;
struct se_cmd *cmd = req->end_io_data;
req->end_io_data = cmd;
struct completion *c = req->end_io_data;
req->end_io_data = &wait;