From f31ecf671ddc498f20219453395794ff2383e06b Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 10 Jul 2023 16:14:37 -0600 Subject: io_uring: add IORING_OP_WAITID support 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 --- include/linux/io_uring_types.h | 2 ++ include/uapi/linux/io_uring.h | 2 ++ 2 files changed, 4 insertions(+) (limited to 'include') diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h index 13d19b9be9f4..fe1c5d4ec56c 100644 --- a/include/linux/io_uring_types.h +++ b/include/linux/io_uring_types.h @@ -313,6 +313,8 @@ struct io_ring_ctx { struct list_head cq_overflow_list; struct io_hash_table cancel_table; + struct hlist_head waitid_list; + const struct cred *sq_creds; /* cred used for __io_sq_thread() */ struct io_sq_data *sq_data; /* if using sq thread polling */ diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index d127948b0d8a..683ac2b74721 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -65,6 +65,7 @@ struct io_uring_sqe { __u32 xattr_flags; __u32 msg_ring_flags; __u32 uring_cmd_flags; + __u32 waitid_flags; }; __u64 user_data; /* data to be passed back at completion time */ /* pack this to avoid bogus arm OABI complaints */ @@ -241,6 +242,7 @@ enum io_uring_op { IORING_OP_SEND_ZC, IORING_OP_SENDMSG_ZC, IORING_OP_READ_MULTISHOT, + IORING_OP_WAITID, /* this goes last, obviously */ IORING_OP_LAST, -- cgit v1.2.3