to #26323588

commit 6c8a31346925cbb373f84a18428ab3df59d3950e upstream.

Grab requests from cache-array from the end, so can get by only
free_reqs.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>