gosfs.h

GEEKOS是一个免费的操作系统内核

/*
 * GeekOS file system
 * Copyright (c) 2003, Jeffrey K. Hollingsworth <[e-mail]>
 * Copyright (c) 2004, David H. Hovemeyer <[e-mail]>
 * $Revision: 1.19 $
 *
 * This is free software.  You are permitted to use,
 * redistribute, and modify it as specified in the file "COPYING".
 */

#ifndef GEEKOS_GOSFS_H
#define GEEKOS_GOSFS_H

#include <geekos/blockdev.h>
#include <geekos/fileio.h>
#include <geekos/vfs.h>

/* Number of disk sectors per filesystem block. */
#define GOSFS_SECTORS_PER_FS_BLOCK	8

/* Size of a filesystem block in bytes. */
#define GOSFS_FS_BLOCK_SIZE		(GOSFS_SECTORS_PER_FS_BLOCK*SECTOR_SIZE)

/* Flags bits for directory entries. */
#define GOSFS_DIRENTRY_USED		0x01	/* Directory entry is in use. */
#define GOSFS_DIRENTRY_ISDIRECTORY	0x02	/* Directory entry refers to a subdirectory. */
#define GOSFS_DIRENTRY_SETUID		0x04	/* File executes using uid of file owner. */

#define GOSFS_FILENAME_MAX		127	/* Maximum filename length. */

#define GOSFS_NUM_DIRECT_BLOCKS		8	/* Number of direct blocks in dir entry. */
#define GOSFS_NUM_INDIRECT_BLOCKS	1	/* Number of singly-indirect blocks in dir entry. */
#define GOSFS_NUM_2X_INDIRECT_BLOCKS	1	/* Number of doubly-indirect blocks in dir entry. */

/* Number of block pointers that can be stored in a single filesystem block. */
#define GOSFS_NUM_PTRS_PER_BLOCK	(GOSFS_FS_BLOCK_SIZE / sizeof(ulong_t))

/* Total number of block pointers in a directory entry. */
#define GOSFS_NUM_BLOCK_PTRS \
    (GOSFS_NUM_DIRECT_BLOCKS+GOSFS_NUM_INDIRECT_BLOCKS+GOSFS_NUM_2X_INDIRECT_BLOCKS)

/*
 * A directory entry.
 * It is strongly recommended that you don't change this struct.
 */
struct GOSFS_Dir_Entry {
    ulong_t size;				/* Size of file. */
    ulong_t flags;				/* Flags: used, isdirectory, setuid. */
    char filename[GOSFS_FILENAME_MAX+1];	/* Filename (including space for nul-terminator). */
    ulong_t blockList[GOSFS_NUM_BLOCK_PTRS];	/* Pointers to direct, indirect, and doubly-indirect blocks. */
    struct VFS_ACL_Entry acl[VFS_MAX_ACL_ENTRIES];/* List of ACL entries; first is for the file's owner. */
};

/* Number of directory entries that fit in a filesystem block. */
#define GOSFS_DIR_ENTRIES_PER_BLOCK	(GOSFS_FS_BLOCK_SIZE / sizeof(struct GOSFS_Dir_Entry))

void Init_GOSFS(void);

#endif