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Diffstat (limited to 'include/linux/jffs.h')
| -rw-r--r-- | include/linux/jffs.h | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/include/linux/jffs.h b/include/linux/jffs.h new file mode 100644 index 000000000000..92213215277f --- /dev/null +++ b/include/linux/jffs.h @@ -0,0 +1,224 @@ +/* + * 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__ */ |