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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-17 02:20:36 +0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-17 02:20:36 +0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/linux/jffs.h
downloadlinux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'include/linux/jffs.h')
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diff --git a/include/linux/jffs.h b/include/linux/jffs.h
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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 1.20 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__ */