Commit 3e4827b0 authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring: add support for epoll_ctl(2) 



This adds IORING_OP_EPOLL_CTL, which can perform the same work as the
epoll_ctl(2) system call.

Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 39220e8d

fs/io_uring.c

+71 −0
Original line number Diff line number Diff line
@@ -74,6 +74,7 @@ 
#include <linux/namei.h>

#include <linux/fsnotify.h>

#include <linux/fadvise.h>

#include <linux/eventpoll.h>



#define CREATE_TRACE_POINTS

#include <trace/events/io_uring.h>
@@ -423,6 +424,14 @@ struct io_madvise { 
	u32				advice;

};



struct io_epoll {

	struct file			*file;

	int				epfd;

	int				op;

	int				fd;

	struct epoll_event		event;

};



struct io_async_connect {

	struct sockaddr_storage		address;

};
@@ -536,6 +545,7 @@ struct io_kiocb { 
		struct io_files_update	files_update;

		struct io_fadvise	fadvise;

		struct io_madvise	madvise;

		struct io_epoll		epoll;

	};



	struct io_async_ctx		*io;
@@ -728,6 +738,10 @@ static const struct io_op_def io_op_defs[] = { 
		.fd_non_neg		= 1,

		.file_table		= 1,

	},

	[IORING_OP_EPOLL_CTL] = {

		.unbound_nonreg_file	= 1,

		.file_table		= 1,

	},

};



static void io_wq_submit_work(struct io_wq_work **workptr);
@@ -2611,6 +2625,52 @@ static int io_openat(struct io_kiocb *req, struct io_kiocb **nxt, 
	return io_openat2(req, nxt, force_nonblock);

}



static int io_epoll_ctl_prep(struct io_kiocb *req,

			     const struct io_uring_sqe *sqe)

{

#if defined(CONFIG_EPOLL)

	if (sqe->ioprio || sqe->buf_index)

		return -EINVAL;



	req->epoll.epfd = READ_ONCE(sqe->fd);

	req->epoll.op = READ_ONCE(sqe->len);

	req->epoll.fd = READ_ONCE(sqe->off);



	if (ep_op_has_event(req->epoll.op)) {

		struct epoll_event __user *ev;



		ev = u64_to_user_ptr(READ_ONCE(sqe->addr));

		if (copy_from_user(&req->epoll.event, ev, sizeof(*ev)))

			return -EFAULT;

	}



	return 0;

#else

	return -EOPNOTSUPP;

#endif

}



static int io_epoll_ctl(struct io_kiocb *req, struct io_kiocb **nxt,

			bool force_nonblock)

{

#if defined(CONFIG_EPOLL)

	struct io_epoll *ie = &req->epoll;

	int ret;



	ret = do_epoll_ctl(ie->epfd, ie->op, ie->fd, &ie->event, force_nonblock);

	if (force_nonblock && ret == -EAGAIN)

		return -EAGAIN;



	if (ret < 0)

		req_set_fail_links(req);

	io_cqring_add_event(req, ret);

	io_put_req_find_next(req, nxt);

	return 0;

#else

	return -EOPNOTSUPP;

#endif

}



static int io_madvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)

{

#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
@@ -4075,6 +4135,9 @@ static int io_req_defer_prep(struct io_kiocb *req, 
	case IORING_OP_OPENAT2:

		ret = io_openat2_prep(req, sqe);

		break;

	case IORING_OP_EPOLL_CTL:

		ret = io_epoll_ctl_prep(req, sqe);

		break;

	default:

		printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",

				req->opcode);
@@ -4303,6 +4366,14 @@ static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe, 
		}

		ret = io_openat2(req, nxt, force_nonblock);

		break;

	case IORING_OP_EPOLL_CTL:

		if (sqe) {

			ret = io_epoll_ctl_prep(req, sqe);

			if (ret)

				break;

		}

		ret = io_epoll_ctl(req, nxt, force_nonblock);

		break;

	default:

		ret = -EINVAL;

		break;

include/uapi/linux/io_uring.h

+1 −0
Original line number Diff line number Diff line
@@ -112,6 +112,7 @@ enum { 
	IORING_OP_SEND,

	IORING_OP_RECV,

	IORING_OP_OPENAT2,

	IORING_OP_EPOLL_CTL,



	/* this goes last, obviously */

	IORING_OP_LAST,