uffd: Hide page server socket back

With epoll helpers in util we can stop exposing the
page-server socket to the oter world.

travis-ci: success for Some more cleanups over uffd.c (rev3)
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Acked-by: Mike Rapoport <rppt@linux.vnet.ibm.com>

criu/cr-dump.c

@@ -1565,7 +1565,7 @@ int cr_pre_dump_tasks(pid_t pid)
 	if (vdso_init())
 		goto err;
 
-	if (connect_to_page_server() < 0)
+	if (connect_to_page_server_to_send() < 0)
 		goto err;
 
 	if (setup_alarm_handler())
@@ -1761,7 +1761,7 @@ int cr_dump_tasks(pid_t pid)
 			goto err;
 	}
 
-	if (connect_to_page_server() < 0)
+	if (connect_to_page_server_to_send() < 0)
 		goto err;
 
 	if (setup_alarm_handler())

criu/include/page-xfer.h

@@ -37,7 +37,8 @@ extern int open_page_xfer(struct page_xfer *xfer, int fd_type, long id);
 struct page_pipe;
 extern int page_xfer_dump_pages(struct page_xfer *, struct page_pipe *,
 				unsigned long off, bool dump_lazy);
-extern int connect_to_page_server(void);
+extern int connect_to_page_server_to_send(void);
+extern int connect_to_page_server_to_recv(int epfd);
 extern int disconnect_from_page_server(void);
 
 extern int check_parent_page_xfer(int fd_type, long id);
@@ -60,6 +61,5 @@ extern int receive_remote_pages(int len, void *buf);
 typedef int (*ps_async_read_complete)(int pid, unsigned long vaddr, int nr_pages, void *);
 extern int page_server_start_async_read(void *buf, int nr_pages,
 		ps_async_read_complete complete, void *priv);
-extern int page_server_async_read(void);
 
 #endif /* __CR_PAGE_XFER__H__ */

criu/page-xfer.c

@@ -885,7 +885,7 @@ no_server:
 	return ret;
 }
 
-int connect_to_page_server(void)
+static int connect_to_page_server(void)
 {
 	if (!opts.use_page_server)
 		return 0;
@@ -906,7 +906,12 @@ out:
 	 * on urgent data is the smartest mode ever.
 	 */
 	tcp_cork(page_server_sk, true);
-	return page_server_sk;
+	return 0;
+}
+
+int connect_to_page_server_to_send(void)
+{
+	return connect_to_page_server();
 }
 
 int disconnect_from_page_server(void)
@@ -993,7 +998,7 @@ int page_server_start_async_read(void *buf, int nr_pages,
  * for sure the next time socket event will occur we'll get page data
  * related to info we've just received
  */
-int page_server_async_read(void)
+static int page_server_async_read(struct epoll_rfd *f)
 {
 	struct ps_async_read *ar;
 	int ret, need;
@@ -1035,6 +1040,19 @@ int page_server_async_read(void)
 	return ret;
 }
 
+static struct epoll_rfd ps_rfd;
+
+int connect_to_page_server_to_recv(int epfd)
+{
+	if (connect_to_page_server())
+		return -1;
+
+	ps_rfd.fd = page_server_sk;
+	ps_rfd.revent = page_server_async_read;
+
+	return epoll_add_rfd(epfd, &ps_rfd);
+}
+
 int request_remote_pages(int pid, unsigned long addr, int nr_pages)
 {
 	struct page_server_iov pi = {

criu/uffd.c

@@ -805,27 +805,6 @@ close_uffd:
 	return -1;
 }
 
-static int page_server_event(struct epoll_rfd *lpfd)
-{
-	return page_server_async_read();
-}
-
-static struct epoll_rfd page_server_sk_fd;
-
-static int prepare_page_server_socket(int epollfd)
-{
-	int sk;
-
-	sk = connect_to_page_server();
-	if (sk < 0)
-		return -1;
-
-	page_server_sk_fd.revent = page_server_event;
-	page_server_sk_fd.fd = sk;
-
-	return epoll_add_rfd(epollfd, &page_server_sk_fd);
-}
-
 int cr_lazy_pages(bool daemon)
 {
 	struct epoll_event *events;
@@ -876,7 +855,7 @@ int cr_lazy_pages(bool daemon)
 		return -1;
 
 	if (opts.use_page_server) {
-		if (prepare_page_server_socket(epollfd))
+		if (connect_to_page_server_to_recv(epollfd))
 			return -1;
 	}