Hi, We currently only support looking up and canceling requests based on the user_data of the original request. Sometimes it can be useful to instead key off the fd used in the original request, eg if a socket goes away. Patch 1 is just a cleanup spotted while doing this, 2 is a prep patch, patch 3 adds support for IORING_ASYNC_CANCEL_ALL, patch 4 adds support for IORING_ASYNC_CANCEL_FD, and patch 5 adds support for matching any request (useful with CANCEL_ALL). If IORING_ASYNC_CANCEL_ALL is set, all requests matching the given criteria are canceled. Return value is number of requests canceled, and 0 if none were found, or any error encountered canceling requests. If IORING_ASYNC_CANCEL_FD is set, requests matching sqe->fd are canceled rather than matching on sqe->addr for user_data. If IORING_ASYNC_CANCEL_ANY is set, all requests are matched vs using the fd or user_data key. There's some support in the below liburing branch: https://git.kernel.dk/cgit/liburing/log/?h=cancel-fd-all which also has various test cases. v4: - Minor cleanups - Rebase on current tree - Add IORING_ASYNC_CANCEL_ANY -- Jens Axboe
