draft some of the spec for the new filesystem idea

1 files changed, 31 insertions, 11 deletions

diff --git a/docs/vfs.org b/docs/vfs.org
index fda0799..7312851 100644
--- a/docs/vfs.org
+++ b/docs/vfs.org
@@ -9,20 +9,40 @@
 *** be the only abstraction for accessing resources / access control
     I don't really know how to explain this well (TODO). In short: the less shit there is to manage, the easier it is to manage.
 * operations
-** creating filesystems
-   ~fs_t create_fs(struct fs_impl);~
-   
-   ~fs_impl~ contains a bunch of function pointers to the implementations of the basic filesystem operations - so, all the functions mentioned in the file IO section.
-
+** mounting
+   ~void mount(path_t path, fd_t fd);~
    
-   ~fs_t create_bind(path_t path);~
+   Mounts ~fd~ over ~path~ (~path~ doesn't have to be a real directory/file!). The files previously accessible under ~path~ won't ever be accessible anymore to the process or any of its children. If the ~fd~ refers to a file/directory, a bind mount is created. The bind mount is a copy of the original mount, so it will persist even if the latter is gone. This means that you can e.g. mount a directory over ~/~ and it will work like a chroot.
+** creating filesystems
+   ~fd_t fs_create(fs_handle_t *);~
+   ~void fs_destroy(fs_handle_t *);~
    
-   Creates a filesystem which is just a view of the current process' VFS at ~path~. Can be used for bind mounts.
-   note: This can be implemented fully in userland, using only ~create_fs()~. That doesn't mean that it's a good idea, the performance would be awful.
-** mounting
-   ~void mount(path_t path, fs_t fs);~
+   ~void fs_wait(fs_handle_t, fs_call_t *info);~
+   Waits for a filesystem request, the details of which will be put in ~info~.
    
-   Mounts ~fs~ over ~path~ (which doesn't have to be a real directory/file!). The files that were previously accessible on ~path~ will NOT be accessible anymore. The calls to ~fs~ won't include the ~path~. ~path~
+   ~void fs_respond(fs_call_t *info);~
+   Responds to a filesystem request.
+*** TODO more details
+*** example
+    #+begin_src C
+struct fs_call call;
+fs_handle_t myfs_back;
+fd_t myfs_front;
+
+myfs_front = fs_create(&myfs_back);
+mount("/some/where", myfs_front);
+
+for (;;) {
+	fs_wait(myfs_back, &call);
+	switch (call.type) {
+		case FS_CLEANUP:
+			break;
+		default:
+			call.error = ENOTIMPLEMENTED;
+	}
+	fs_respond(&call);
+}
+    #+end_src
 ** file IO
    ~fd_t open(path_t path);~