tree 89c307e276bef985b803920bb2c744f8a16e2570
parent c98de08c990e190fc7cc3aaf8079b4a0674c6425
author Pavel Begunkov <asml.silence@gmail.com> 1605729446 +0000
committer Jens Axboe <axboe@kernel.dk> 1607540641 -0700

io_uring: share fixed_file_refs b/w multiple rsrcs

Double fixed files for splice/tee are done in a nasty way, it takes 2
ref_node refs, and during the second time it blindly overrides
req->fixed_file_refs hoping that it haven't changed. That works because
all that is done under iouring_lock in a single go but is error-prone.

Bind everything explicitly to a single ref_node and take only one ref,
with current ref_node ordering it's guaranteed to keep all files valid
awhile the request is inflight.

That's mainly a cleanup + preparation for generic resource handling,
but also saves pcpu_ref get/put for splice/tee with 2 fixed files.

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