5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Pavel Begunkov asml.silence@gmail.com
From: Dylan Yudaken dylany@meta.com
[ upstream commit c06c6c5d276707e04cedbcc55625e984922118aa ]
This is required for the failure case (io_req_complete_failed) and is missing.
The alternative would be to only lock in the failure path, however all of the non-error paths in io_poll_check_events that do not do not return IOU_POLL_NO_ACTION end up locking anyway. The only extraneous lock would be for the multishot poll overflowing the CQE ring, however multishot poll would probably benefit from being locked as it will allow completions to be batched.
So it seems reasonable to lock always.
Signed-off-by: Dylan Yudaken dylany@meta.com Link: https://lore.kernel.org/r/20221124093559.3780686-3-dylany@meta.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Pavel Begunkov asml.silence@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- io_uring/io_uring.c | 1 + 1 file changed, 1 insertion(+)
--- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -5716,6 +5716,7 @@ static void io_apoll_task_func(struct io if (ret > 0) return;
+ io_tw_lock(req->ctx, locked); io_poll_remove_entries(req); spin_lock(&ctx->completion_lock); hash_del(&req->hash_node);