include/linux/jffs.h - kernel/msm-4.9 - Gitiles

 /*
  * 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 1.20 2001/09/18 21:33:37 dwmw2 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;
 #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__ */
	/*
	* 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 1.20 2001/09/18 21:33:37 dwmw2 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;
	#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__ */