io_uring: fix cancel of deferred reqs with ->files

io_uring: fix cancel of deferred reqs with ->files

[ Upstream commit b7ddce3cbf010edbfac6c6d8cc708560a7bcd7a4 ]

While trying to cancel requests with ->files, it also should look for
requests in ->defer_list, otherwise it might end up hanging a thread.

Cancel all requests in ->defer_list up to the last request there with
matching ->files, that's needed to follow drain ordering semantics.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>