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/*

 * JFFS -- Journalling Flash File System, Linux implementation.

 *

 * Copyright (C) 1999, 2000  Axis Communications AB.

 *

 * Created by Finn Hakansson <finn@axis.com>.

 *

 * 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 2004-01-28 15:25:47 giacomo Exp $

 *

 * Ported to Linux 2.3.x and MTD:

 * Copyright (C) 2000  Alexander Larsson (alex@cendio.se), Cendio Systems AB

 *

 */

#ifndef __LINUX_JFFS_H__

#define __LINUX_JFFS_H__

#include <linux/types.h>

#include <linux/completion.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

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;  /* Rename to a name of an already existing file?  */

        __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 list_head hash;    /* 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.  */

};

/* This is just a definition of a simple list used for keeping track of

   files deleted due to a rename.  This list is only used during the

   mounting of the file system and only if there have been rename operations

   earlier.  */

struct jffs_delete_list

{

        __u32 ino;

        struct jffs_delete_list *next;

};

/* 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 list_head *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?  */

        struct jffs_delete_list *delete_list; /* Track deleted files.  */

        pid_t thread_pid;               /* GC thread's PID */

        struct task_struct *gc_task;    /* GC task struct */

        struct completion gc_thread_comp; /* GC thread exit mutex */

        __u32 gc_minfree_threshold;     /* GC trigger thresholds */

        __u32 gc_maxdirty_threshold;

};

/* 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

extern long no_jffs_node;

extern long no_jffs_file;

#if defined(JFFS_MEMORY_DEBUG) && JFFS_MEMORY_DEBUG

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

#endif /* __LINUX_JFFS_H__ */