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/*
 * JFFS -- Journalling Flash File System, Linux implementation.
 *
 * Copyright (C) 1999, 2000  Finn Hakansson, Axis Communications, Inc.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * $Id: jffs.h,v 1.1 2005-12-20 11:32:24 jcastillo Exp $
 *
 */
 
#ifndef __LINUX_JFFS_H__
#define __LINUX_JFFS_H__
 
#define JFFS_VERSION_STRING "1.0"
 
/* This is a magic number that is used as an identification number for
   this file system.  It is written to the super_block structure.  */
#define JFFS_MAGIC_SB_BITMASK 0x07c0  /* 1984 */
 
/* This is a magic number that every on-flash raw inode begins with.  */
#define JFFS_MAGIC_BITMASK 0x34383931 /* "1984" */
 
/* These two bitmasks are the valid ones for the flash memories we have
   for the moment.  */
#define JFFS_EMPTY_BITMASK 0xffffffff
#define JFFS_DIRTY_BITMASK 0x00000000
 
/* This is the inode number of the root node.  */
#define JFFS_MIN_INO 1
 
/* How many slots in the file hash table should we have?  */
#define JFFS_HASH_SIZE 40
 
/* Don't use more than 254 bytes as the maximum allowed length of a file's
   name due to errors that could occur during the scanning of the flash
   memory. In fact, a name length of 255 or 0xff, could be the result of
   an uncompleted write.  For instance, if a raw inode is written to the
   flash memory and there is a power lossage just before the length of
   the name is written, the length 255 would be interpreted as an illegal
   value.  */
#define JFFS_MAX_NAME_LEN 254
 
/* Commands for ioctl().  */
#define JFFS_IOCTL_MAGIC 't'
#define JFFS_PRINT_HASH _IO(JFFS_IOCTL_MAGIC, 90)
#define JFFS_PRINT_TREE _IO(JFFS_IOCTL_MAGIC, 91)
#define JFFS_GET_STATUS _IO(JFFS_IOCTL_MAGIC, 92)
 
/* XXX: This is something that we should try to get rid of in the future.  */
#define JFFS_MODIFY_INODE 0x01
#define JFFS_MODIFY_NAME  0x02
#define JFFS_MODIFY_DATA  0x04
#define JFFS_MODIFY_EXIST 0x08
 
/* Using the garbage collection mechanism.  */
#define USE_GC
 
struct jffs_control;
 
/* The JFFS raw inode structure: Used for storage on physical media.  */
/* Perhaps the uid, gid, atime, mtime and ctime members should have
   more space due to future changes in the Linux kernel. Anyhow, since
   a user of this filesystem probably have to fix a large number of
   other things, we have decided to not be forward compatible.  */
struct jffs_raw_inode
{
	__u32 magic;      /* A constant magic number.  */
	__u32 ino;        /* Inode number.  */
	__u32 pino;       /* Parent's inode number.  */
	__u32 version;    /* Version number.  */
	__u32 mode;       /* The file's type or mode.  */
	__u16 uid;        /* The file's owner.  */
	__u16 gid;        /* The file's group.  */
	__u32 atime;      /* Last access time.  */
	__u32 mtime;      /* Last modification time.  */
	__u32 ctime;      /* Creation time.  */
	__u32 offset;     /* Where to begin to write.  */
	__u32 dsize;      /* Size of the node's data.  */
	__u32 rsize;      /* How much are going to be replaced?  */
	__u8 nsize;       /* Name length.  */
	__u8 nlink;       /* Number of links.  */
	__u8 spare : 6;   /* For future use.  */
	__u8 rename : 1;  /* Is this a special rename?  */
	__u8 deleted : 1; /* Has this file been deleted?  */
	__u8 accurate;    /* The inode is obsolete if accurate == 0.  */
	__u32 dchksum;    /* Checksum for the data.  */
	__u16 nchksum;    /* Checksum for the name.  */
	__u16 chksum;     /* Checksum for the raw inode.  */
};
 
/* Define the offset of the accurate byte in struct jffs_raw_inode.  */
#define JFFS_RAW_INODE_ACCURATE_OFFSET (sizeof(struct jffs_raw_inode) \
					- 2 * sizeof(__u32) - sizeof(__u8))
 
/* Define the offset of the chksum member in struct jffs_raw_inode.  */
#define JFFS_RAW_INODE_CHKSUM_OFFSET (sizeof(struct jffs_raw_inode) \
				      - sizeof(__u16))
 
/* Define the offset of the dchksum member in struct jffs_raw_inode.  */
#define JFFS_RAW_INODE_DCHKSUM_OFFSET (sizeof(struct jffs_raw_inode)   \
				       - sizeof(__u16) - sizeof(__u16) \
				       - sizeof(__u32))
 
 
/* The RAM representation of the node.  The names of pointers to
   jffs_nodes are very often just called `n' in the source code.  */
struct jffs_node
{
	__u32 ino;          /* Inode number.  */
	__u32 version;      /* Version number.  */
	__u32 data_offset;  /* Logic location of the data to insert.  */
	__u32 data_size;    /* The amount of data this node inserts.  */
	__u32 removed_size; /* The amount of data that this node removes.  */
	__u32 fm_offset;    /* Physical location of the data in the actual
			       flash memory data chunk.  */
	__u8 name_size;     /* Size of the name.  */
	struct jffs_fm *fm; /* Physical memory information.  */
	struct jffs_node *version_prev;
	struct jffs_node *version_next;
	struct jffs_node *range_prev;
	struct jffs_node *range_next;
};
 
 
/* The RAM representation of a file (plain files, directories,
   links, etc.).  Pointers to jffs_files are normally named `f'
   in the JFFS source code.  */
struct jffs_file
{
	__u32 ino;    /* Inode number.  */
	__u32 pino;   /* Parent's inode number.  */
	__u32 mode;   /* file_type, mode  */
	__u16 uid;    /* owner  */
	__u16 gid;    /* group  */
	__u32 atime;  /* Last access time.  */
	__u32 mtime;  /* Last modification time.  */
	__u32 ctime;  /* Creation time.  */
	__u8 nsize;   /* Name length.  */
	__u8 nlink;   /* Number of links.  */
	__u8 deleted; /* Has this file been deleted?  */
	char *name;   /* The name of this file; NULL-terminated.  */
	__u32 size;   /* The total size of the file's data.  */
	__u32 highest_version; /* The highest version number of this file.  */
	struct jffs_control *c;
	struct jffs_file *parent;   /* Reference to the parent directory.  */
	struct jffs_file *children; /* Always NULL for plain files.  */
	struct jffs_file *sibling_prev; /* Siblings in the same directory.  */
	struct jffs_file *sibling_next;
	struct jffs_file *hash_prev;    /* Previous file in hash list.  */
	struct jffs_file *hash_next;    /* Next file in hash list.  */
	struct jffs_node *range_head;   /* The final data.  */
	struct jffs_node *range_tail;   /* The first data.  */
	struct jffs_node *version_head; /* The youngest node.  */
	struct jffs_node *version_tail; /* The oldest node.  */
};
 
 
/* A struct for the overall file system control.  Pointers to
   jffs_control structs are named `c' in the source code.  */
struct jffs_control
{
	struct super_block *sb;  /* Reference to the VFS super block.  */
	struct jffs_file *root;  /* The root directory file.  */
	struct jffs_file **hash; /* Hash table for finding files by ino.  */
	struct jffs_fmcontrol *fmc; /* Flash memory control structure.  */
	__u32 hash_len;    /* The size of the hash table.  */
	__u32 next_ino;    /* Next inode number to use for new files.  */
	__u16 building_fs; /* Is the file system being built right now?  */
	int rename_lock;   /* Used by jffs_rename().  */
	struct wait_queue *rename_wait; /* Likewise.  */
};
 
 
/* Used to inform about flash status.  */
struct jffs_flash_status
{
	__u32 size;
	__u32 used;
	__u32 dirty;
	__u32 begin;
	__u32 end;
};
 
/* This stuff could be used for finding memory leaks.  */
#define JFFS_MEMORY_DEBUG 0
 
#if defined(JFFS_MEMORY_DEBUG) && JFFS_MEMORY_DEBUG
extern long no_jffs_file;
extern long no_jffs_node;
extern long no_jffs_control;
extern long no_jffs_raw_inode;
extern long no_jffs_node_ref;
extern long no_jffs_fm;
extern long no_jffs_fmcontrol;
extern long no_hash;
extern long no_name;
#define DJM(x) x
#else
#define DJM(x)
#endif
 
 
#ifdef __KERNEL__
extern int init_jffs_fs(void);
#endif /* __KERNEL__ */
 
#endif /* __LINUX_JFFS_H__ */