/* * JFFS -- Journalling Flash File System, Linux implementation. * * Copyright (C) 1999, 2000 Axis Communications AB. * * Created by Finn Hakansson . * * 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 #include #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__ */