io_uring: rewrite methods and add missing structs

fs/io_uring.c

@@ -9299,55 +9299,55 @@ static int io_allocate_scq_urings(struct io_ring_ctx *ctx,
 	return 0;
 }
 
+static int io_uring_install_fd(struct io_ring_ctx *ctx, struct file *file)
+{
+	int ret, fd;
+
+	fd = get_unused_fd_flags(O_RDWR | O_CLOEXEC);
+	if (fd < 0)
+		return fd;
+
+	ret = io_uring_add_task_file(ctx, file);
+	if (ret) {
+		put_unused_fd(fd);
+		return ret;
+	}
+	fd_install(fd, file);
+	return fd;
+}
+
 /*
  * Allocate an anonymous fd, this is what constitutes the application
  * visible backing of an io_uring instance. The application mmaps this
  * fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled,
  * we have to tie this fd to a socket for file garbage collection purposes.
  */
-static int io_uring_get_fd(struct io_ring_ctx *ctx)
+static struct file *io_uring_get_file(struct io_ring_ctx *ctx)
 {
 	struct file *file;
+#if defined(CONFIG_UNIX)
 	int ret;
-	int fd;
 
-#if defined(CONFIG_UNIX)
 	ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP,
 				&ctx->ring_sock);
 	if (ret)
-		return ret;
+		return ERR_PTR(err);
 #endif
 
-	ret = get_unused_fd_flags(O_RDWR | O_CLOEXEC);
-	if (ret < 0)
-		goto err;
-	fd = ret;
-
 	file = anon_inode_getfile("[io_uring]", &io_uring_fops, ctx,
-					O_RDWR | O_CLOEXEC);
-	if (IS_ERR(file)) {
-		put_unused_fd(fd);
-		ret = PTR_ERR(file);
-		goto err;
-	}
+							  O_RDWR | O_CLOEXEC);
 
 #if defined(CONFIG_UNIX)
-	ctx->ring_sock->file = file;
-#endif
-	ret = io_uring_add_task_file(ctx, file);
-	if (ret) {
-		fput(file);
-		put_unused_fd(fd);
-		goto err;
+	if (IS_ERR(file)) {
+		sock_release(ctx->ring_sock);
+		ctx->ring_sock = NULL;
+	} else {
+		ctx->ring_sock->file = file;
 	}
-	fd_install(fd, file);
-	return fd;
-err:
-#if defined(CONFIG_UNIX)
 	sock_release(ctx->ring_sock);
 	ctx->ring_sock = NULL;
 #endif
-	return ret;
+	return file;
 }
 
 static int io_uring_create(unsigned entries, struct io_uring_params *p,