the-tree/io_uring/epoll.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 #include <linux/kernel.h>
0003 #include <linux/errno.h>
0004 #include <linux/file.h>
0005 #include <linux/fs.h>
0006 #include <linux/uaccess.h>
0007 #include <linux/io_uring.h>
0008 #include <linux/eventpoll.h>
0009
0010 #include <uapi/linux/io_uring.h>
0011
0012 #include "io_uring.h"
0013 #include "epoll.h"
0014
0015 #if defined(CONFIG_EPOLL)
0016 struct io_epoll {
0017     struct file         *file;
0018     int             epfd;
0019     int             op;
0020     int             fd;
0021     struct epoll_event      event;
0022 };
0023
0024 int io_epoll_ctl_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
0025 {
0026     struct io_epoll *epoll = io_kiocb_to_cmd(req, struct io_epoll);
0027
0028     pr_warn_once("%s: epoll_ctl support in io_uring is deprecated and will "
0029              "be removed in a future Linux kernel version.\n",
0030              current->comm);
0031
0032     if (sqe->buf_index || sqe->splice_fd_in)
0033         return -EINVAL;
0034
0035     epoll->epfd = READ_ONCE(sqe->fd);
0036     epoll->op = READ_ONCE(sqe->len);
0037     epoll->fd = READ_ONCE(sqe->off);
0038
0039     if (ep_op_has_event(epoll->op)) {
0040         struct epoll_event __user *ev;
0041
0042         ev = u64_to_user_ptr(READ_ONCE(sqe->addr));
0043         if (copy_from_user(&epoll->event, ev, sizeof(*ev)))
0044             return -EFAULT;
0045     }
0046
0047     return 0;
0048 }
0049
0050 int io_epoll_ctl(struct io_kiocb *req, unsigned int issue_flags)
0051 {
0052     struct io_epoll *ie = io_kiocb_to_cmd(req, struct io_epoll);
0053     int ret;
0054     bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
0055
0056     ret = do_epoll_ctl(ie->epfd, ie->op, ie->fd, &ie->event, force_nonblock);
0057     if (force_nonblock && ret == -EAGAIN)
0058         return -EAGAIN;
0059
0060     if (ret < 0)
0061         req_set_fail(req);
0062     io_req_set_res(req, ret, 0);
0063     return IOU_OK;
0064 }
0065 #endif