scaffolding for user fs dispatch

4 files changed, 24 insertions, 1 deletions

diff --git a/src/kernel/proc.h b/src/kernel/proc.h
index 447dac8..0efccde 100644
--- a/src/kernel/proc.h
+++ b/src/kernel/proc.h
@@ -8,6 +8,8 @@ enum process_state {
 	PS_DEAD,    // return message wasn't collected
 	PS_DEADER,  // return message was collected
 	PS_WAITS4CHILDDEATH,
+	PS_WAITS4FS,
+	PS_WAITS4REQUEST,
 };
 
 struct process {
diff --git a/src/kernel/syscalls.c b/src/kernel/syscalls.c
index d2217eb..ddc3d4b 100644
--- a/src/kernel/syscalls.c
+++ b/src/kernel/syscalls.c
@@ -179,6 +179,9 @@ handle_t _syscall_fs_create(user_ptr back_user) {
 
 	backend = kmalloc(sizeof(struct vfs_backend)); // TODO never freed
 	backend->type = VFS_BACK_USER;
+	backend->handler = NULL;
+	backend->queue = NULL;
+
 	process_current->handles[front].fs.backend = backend;
 	process_current->handles[back ].fs.backend = backend;
 
diff --git a/src/kernel/vfs/backend.c b/src/kernel/vfs/backend.c
index 9a2b777..0f684a0 100644
--- a/src/kernel/vfs/backend.c
+++ b/src/kernel/vfs/backend.c
@@ -14,6 +14,20 @@ _Noreturn void vfs_backend_dispatch(struct vfs_backend *backend, struct vfs_op o
 		case VFS_BACK_ROOT:
 			int ret = vfs_root_handler(&req);
 			vfs_backend_finish(&req, ret);
+		case VFS_BACK_USER:
+			process_current->state = PS_WAITS4FS;
+			if (backend->handler == NULL) { // backend not ready yet
+				if (backend->queue == NULL) {
+					backend->queue = process_current;
+					process_switch_any();
+				} else {
+					panic(); // TODO implement a proper queue
+				}
+			} else {
+				if (backend->handler->state != PS_WAITS4REQUEST)
+					panic(); // invalid state
+				panic(); // TODO
+			}
 		default:
 			panic();
 	}
diff --git a/src/kernel/vfs/backend.h b/src/kernel/vfs/backend.h
index fe46db1..bf16ee7 100644
--- a/src/kernel/vfs/backend.h
+++ b/src/kernel/vfs/backend.h
@@ -6,9 +6,13 @@ enum vfs_backend_type {
 	VFS_BACK_USER,
 };
 
-// describes something which can acts as an access function
+// describes something which can act as an access function
 struct vfs_backend {
 	enum vfs_backend_type type;
+
+	// only used with VFS_BACK_USER
+	struct process *handler;
+	struct process *queue;
 };
 
 // describes an in-progress vfs call