io_uring: move epoll handler to its own file

Would be nice to sort out Kconfig for this and don't even compile
epoll.c if we don't have epoll configured.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

io_uring/Makefile

@@ -4,5 +4,5 @@
 
 obj-$(CONFIG_IO_URING)		+= io_uring.o xattr.o nop.o fs.o splice.o \
 					sync.o advise.o filetable.o \
-					openclose.o uring_cmd.o
+					openclose.o uring_cmd.o epoll.o
 obj-$(CONFIG_IO_WQ)		+= io-wq.o

io_uring/epoll.c

+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/uaccess.h>
+#include <linux/io_uring.h>
+#include <linux/eventpoll.h>
+
+#include <uapi/linux/io_uring.h>
+
+#include "io_uring_types.h"
+#include "io_uring.h"
+#include "epoll.h"
+
+#if defined(CONFIG_EPOLL)
+struct io_epoll {
+	struct file			*file;
+	int				epfd;
+	int				op;
+	int				fd;
+	struct epoll_event		event;
+};
+
+int io_epoll_ctl_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+	struct io_epoll *epoll = io_kiocb_to_cmd(req);
+
+	if (sqe->buf_index || sqe->splice_fd_in)
+		return -EINVAL;
+
+	epoll->epfd = READ_ONCE(sqe->fd);
+	epoll->op = READ_ONCE(sqe->len);
+	epoll->fd = READ_ONCE(sqe->off);
+
+	if (ep_op_has_event(epoll->op)) {
+		struct epoll_event __user *ev;
+
+		ev = u64_to_user_ptr(READ_ONCE(sqe->addr));
+		if (copy_from_user(&epoll->event, ev, sizeof(*ev)))
+			return -EFAULT;
+	}
+
+	return 0;
+}
+
+int io_epoll_ctl(struct io_kiocb *req, unsigned int issue_flags)
+{
+	struct io_epoll *ie = io_kiocb_to_cmd(req);
+	int ret;
+	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
+
+	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(req);
+	io_req_set_res(req, ret, 0);
+	return IOU_OK;
+}
+#endif

io_uring/epoll.h

+// SPDX-License-Identifier: GPL-2.0
+
+#if defined(CONFIG_EPOLL)
+int io_epoll_ctl_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
+int io_epoll_ctl(struct io_kiocb *req, unsigned int issue_flags);
+#endif

io_uring/io_uring.c

@@ -100,6 +100,7 @@
 #include "advise.h"
 #include "openclose.h"
 #include "uring_cmd.h"
+#include "epoll.h"
 
 #define IORING_MAX_ENTRIES	32768
 #define IORING_MAX_CQ_ENTRIES	(2 * IORING_MAX_ENTRIES)
@@ -374,14 +375,6 @@ struct io_rsrc_update {
 	u32				offset;
 };
 
-struct io_epoll {
-	struct file			*file;
-	int				epfd;
-	int				op;
-	int				fd;
-	struct epoll_event		event;
-};
-
 struct io_provide_buf {
 	struct file			*file;
 	__u64				addr;
@@ -4040,47 +4033,6 @@ static __maybe_unused int io_eopnotsupp_prep(struct io_kiocb *kiocb,
 	return -EOPNOTSUPP;
 }
 
-#if defined(CONFIG_EPOLL)
-static int io_epoll_ctl_prep(struct io_kiocb *req,
-			     const struct io_uring_sqe *sqe)
-{
-	struct io_epoll *epoll = io_kiocb_to_cmd(req);
-
-	if (sqe->buf_index || sqe->splice_fd_in)
-		return -EINVAL;
-
-	epoll->epfd = READ_ONCE(sqe->fd);
-	epoll->op = READ_ONCE(sqe->len);
-	epoll->fd = READ_ONCE(sqe->off);
-
-	if (ep_op_has_event(epoll->op)) {
-		struct epoll_event __user *ev;
-
-		ev = u64_to_user_ptr(READ_ONCE(sqe->addr));
-		if (copy_from_user(&epoll->event, ev, sizeof(*ev)))
-			return -EFAULT;
-	}
-
-	return 0;
-}
-
-static int io_epoll_ctl(struct io_kiocb *req, unsigned int issue_flags)
-{
-	struct io_epoll *ie = io_kiocb_to_cmd(req);
-	int ret;
-	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
-
-	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(req);
-	io_req_set_res(req, ret, 0);
-	return IOU_OK;
-}
-#endif
-
 static int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 {
 	struct io_statx *sx = io_kiocb_to_cmd(req);