Start work on filesystems.

1 files changed, 86 insertions, 0 deletions

diff --git a/src/kernel/include/vfs.h b/src/kernel/include/vfs.h
new file mode 100644
index 0000000..5f7a0d8
--- /dev/null
+++ b/src/kernel/include/vfs.h
@@ -0,0 +1,86 @@
+#pragma once
+
+#include <stdbool.h>
+#include <malloc.h>
+
+typedef struct {
+	// TODO
+	// (should also be moved to a user-visible header)
+} stat_t;
+
+#define FM_READ 	(0x01)
+#define FM_WRITE 	(0x02)
+#define FM_MMAP 	(0x04)
+#define FM_CREATE   (0x10)
+#define FM_TRUNC    (0x20)
+#define FM_APPEND   (0x40)
+
+// How to use :
+// - when using a filesystem : never call the operations in fs_*_ops_t directly, use
+// 		the functions defined bellow
+// - when programming a filesystem : don't worry about allocating the fs_handle_t and fs_t,
+// 		it is done automatically
+
+
+// Structure defining a handle to an open file
+
+typedef struct {
+	size_t (*read)(void* f, size_t offset, size_t len, char* buf);
+	size_t (*write)(void* f, size_t offset, size_t len, const char* buf);
+	void (*close)(void* f);
+} fs_handle_ops_t;
+
+typedef struct fs_handle {
+	int refs;
+	fs_handle_ops_t *ops;
+	void* data;
+	int mode;
+} fs_handle_t;
+
+// Structure defining a filesystem
+
+typedef struct {
+	bool (*open)(void *fs, const char* file, int mode, fs_handle_t *s);
+	bool (*delete)(void *fs, const char* file);
+	bool (*rename)(void *fs, const char* from, const char* to);
+	bool (*stat)(void *fs, const char* file, stat_t *st);
+	int (*ioctl)(void *fs, const char* file, int command, void* data);
+	bool (*add_source)(void* fs, fs_handle_t* source);
+	void (*shutdown)(void *fs);
+} fs_ops_t;
+
+typedef struct fs {
+	int refs;
+	fs_ops_t *ops;
+	void* data;
+} fs_t;
+
+// Structure defining a filesystem driver
+
+typedef struct {
+	bool (*make)(fs_handle_t *source, char* opts, fs_t *d);
+	bool (*detect)(fs_handle_t *source);
+} fs_driver_ops_t;
+
+// Common functions
+
+void register_fs_driver(const char* name, fs_driver_ops_t *ops);
+
+fs_t* make_fs(const char* driver, fs_handle_t *source, char* opts);
+bool fs_add_source(fs_t *fs, fs_handle_t *source);
+void ref_fs(fs_t *fs);
+void unref_fs(fs_t *fs);
+
+bool fs_delete(fs_t *fs, const char* file);
+bool fs_rename(fs_t *fs, const char* from, const char* to);
+bool fs_stat(fs_t *fs, const char* file, stat_t *st);
+int fs_ioctl(fs_t *fs, const char* file, int command, void* data);
+
+fs_handle_t* fs_open(fs_t *fs, const char* file, int mode);
+void ref_file(fs_handle_t *file);
+void unref_file(fs_handle_t *file);
+size_t file_read(fs_handle_t *f, size_t offset, size_t len, char* buf);
+size_t file_write(fs_handle_t *f, size_t offset, size_t len, const char* buf);
+int file_get_mode(fs_handle_t *f);
+
+/* vim: set ts=4 sw=4 tw=0 noet :*/