fileio.h

The main purpose of this project is to add a new scheduling algorithm to GeekOS and to implement a s

/*
 * Interface constants and typedefs shared between kernel/user space
 * Copyright (c) 2003, Jeffrey K. Hollingsworth <[e-mail]>
 * Copyright (c) 2004, David H. Hovemeyer <[e-mail]>
 * $Revision: 1.20 $
 *
 * This is free software.  You are permitted to use,
 * redistribute, and modify it as specified in the file "COPYING".
 */

#ifndef GEEKOS_FILEIO_H
#define GEEKOS_FILEIO_H

#include <stddef.h>
#include <geekos/ktypes.h>

/* Maximum name of a path. */
#define VFS_MAX_PATH_LEN 1023

/* Maximum length of the name of a filesystem type: e.g., "pfat", "gosfs", etc. */
#define VFS_MAX_FS_NAME_LEN 15

/* Maximum number of ACL entries in a directory entry. */
#define VFS_MAX_ACL_ENTRIES 10

/* We assume that all block devices have 512 byte sectors.  */
#define SECTOR_SIZE 512

/* Maximum length for the name of a block device, e.g. "ide0".  */
#define BLOCKDEV_MAX_NAME_LEN 15

/*
 * File permissions.
 * These are used as flags for Open() VFS function.
 * O_READ and O_WRITE are also used in the permissions
 * field of struct VFS_ACL_Entry.
 */
#define O_CREATE        0x1	/* Create the file if it doesn't exist. */
#define O_READ          0x2	/* Open file for reading. */
#define O_WRITE         0x4	/* Open file for writing. */
#define O_EXCL          0x8	/* Don't create file if it already exists. */

/*
 * An entry in an Access Control List (ACL).
 * Represents a set of permissions for a particular user id.
 */
struct VFS_ACL_Entry {
    uint_t uid:28;
    uint_t permission:4;
};

/*
 * Generic structure representing the metadata for a directory entry.
 * This is filled in by the Stat() and FStat() VFS functions.
 */
struct VFS_File_Stat {
    int size;
    int isDirectory:1;
    int isSetuid:1;
    struct VFS_ACL_Entry acls[VFS_MAX_ACL_ENTRIES];
};

/*
 * Generic directory entry structure.
 * This is filled in by the Read_Entry() VFS function.
 */
struct VFS_Dir_Entry {
    char name[1024];
    struct VFS_File_Stat stats;
};

/*
 * A request to mount a filesystem.
 * This is passed as a struct because it would require too many registers
 * to pass all of the information in registers.
 */
struct VFS_Mount_Request {
    char devname[BLOCKDEV_MAX_NAME_LEN+1];/* Name of block device: e.g., "ide1". */
    char prefix[VFS_MAX_PATH_LEN+1];	/* Directory prefix to mount on: e.g., "/d". */
    char fstype[VFS_MAX_FS_NAME_LEN+1];	/* Filesystem type: e.g., "gosfs". */
};

#endif