lib: fs: add library for implementing a filesystem service

lib/libfs/interface/open.c

@@ -0,0 +1,21 @@
+#include <errno.h>
+#include <fs/context.h>
+
+extern kern_status_t fs_msg_open(
+	const struct msg_endpoint *sender,
+	const char *path,
+	int flags,
+	int *out_err,
+	void *arg)
+{
+	struct fs_context *ctx = arg;
+
+	struct fs_dentry *dent = fs_context_resolve_path(ctx, path);
+	if (!dent) {
+		*out_err = ENOENT;
+		return KERN_OK;
+	}
+
+	*out_err = SUCCESS;
+	return KERN_OK;
+}