to #28170604

commit 2fb3e82284fca40afbde5351907f0a5b3be717f9 upstream

Nonblocking do_splice() still may wait for some time on an inode mutex.
Let's play safe and always punt it async.
Reported-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Signed-off-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>