lwn.git - Linux kernel documentation tree maintained by Jonathan Corbet

Age	Commit message (Collapse)	Author
2024-03-15	io_uring/waitid: always remove waitid entry for cancel all	Jens Axboe
	We know the request is either being removed, or already in the process of being removed through task_work, so we can delete it from our waitid list upfront. This is important for remove all conditions, as we otherwise will find it multiple times and prevent cancelation progress. Remove the dead check in cancelation as well for the hash_node being empty or not. We already have a waitid reference check for ownership, so we don't need to check the list too. Cc: stable@vger.kernel.org Fixes: f31ecf671ddc ("io_uring: add IORING_OP_WAITID support") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-09-21	io_uring: add IORING_OP_WAITID support	Jens Axboe
	This adds support for an async version of waitid(2), in a fully async version. If an event isn't immediately available, wait for a callback to trigger a retry. The format of the sqe is as follows: sqe->len The 'which', the idtype being queried/waited for. sqe->fd The 'pid' (or id) being waited for. sqe->file_index The 'options' being set. sqe->addr2 A pointer to siginfo_t, if any, being filled in. buf_index, add3, and waitid_flags are reserved/unused for now. waitid_flags will be used for options for this request type. One interesting use case may be to add multi-shot support, so that the request stays armed and posts a notification every time a monitored process state change occurs. Note that this does not support rusage, on Arnd's recommendation. See the waitid(2) man page for details on the arguments. Signed-off-by: Jens Axboe <axboe@kernel.dk>