YAFFS2 import

Direct import of yaffs as a tarball as of 20071113 from their public
CVS-web at http://www.aleph1.co.uk/cgi-bin/viewcvs.cgi/yaffs2/

The code can also be imported on the command line with:
export CVSROOT=:pserver:anonymous@cvs.aleph1.co.uk:/home/aleph1/cvs cvs logon
(Hit return when asked for a password)
cvs checkout yaffs2

Signed-off-by: William Juul <william.juul@tandberg.com>
Signed-off-by: Stig Olsen <stig.olsen@tandberg.com>

1 files changed, 902 insertions, 0 deletions

diff --git a/fs/yaffs2/yaffs_guts.h b/fs/yaffs2/yaffs_guts.h
new file mode 100644
index 000000000..87b539b05
--- /dev/null
+++ b/fs/yaffs2/yaffs_guts.h
@@ -0,0 +1,902 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system. 
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_GUTS_H__
+#define __YAFFS_GUTS_H__
+
+#include "devextras.h"
+#include "yportenv.h"
+
+#define YAFFS_OK	1
+#define YAFFS_FAIL  0
+
+/* Give us a  Y=0x59, 
+ * Give us an A=0x41, 
+ * Give us an FF=0xFF 
+ * Give us an S=0x53
+ * And what have we got... 
+ */
+#define YAFFS_MAGIC			0x5941FF53
+
+#define YAFFS_NTNODES_LEVEL0	  	16
+#define YAFFS_TNODES_LEVEL0_BITS	4
+#define YAFFS_TNODES_LEVEL0_MASK	0xf
+
+#define YAFFS_NTNODES_INTERNAL 		(YAFFS_NTNODES_LEVEL0 / 2)
+#define YAFFS_TNODES_INTERNAL_BITS 	(YAFFS_TNODES_LEVEL0_BITS - 1)
+#define YAFFS_TNODES_INTERNAL_MASK	0x7
+#define YAFFS_TNODES_MAX_LEVEL		6
+
+#ifndef CONFIG_YAFFS_NO_YAFFS1
+#define YAFFS_BYTES_PER_SPARE		16
+#define YAFFS_BYTES_PER_CHUNK		512
+#define YAFFS_CHUNK_SIZE_SHIFT		9
+#define YAFFS_CHUNKS_PER_BLOCK		32
+#define YAFFS_BYTES_PER_BLOCK		(YAFFS_CHUNKS_PER_BLOCK*YAFFS_BYTES_PER_CHUNK)
+#endif
+
+#define YAFFS_MIN_YAFFS2_CHUNK_SIZE 	1024
+#define YAFFS_MIN_YAFFS2_SPARE_SIZE	32
+
+#define YAFFS_MAX_CHUNK_ID		0x000FFFFF
+
+#define YAFFS_UNUSED_OBJECT_ID		0x0003FFFF
+
+#define YAFFS_ALLOCATION_NOBJECTS	100
+#define YAFFS_ALLOCATION_NTNODES	100
+#define YAFFS_ALLOCATION_NLINKS		100
+
+#define YAFFS_NOBJECT_BUCKETS		256
+
+
+#define YAFFS_OBJECT_SPACE		0x40000
+
+#define YAFFS_CHECKPOINT_VERSION 	3
+
+#ifdef CONFIG_YAFFS_UNICODE
+#define YAFFS_MAX_NAME_LENGTH		127
+#define YAFFS_MAX_ALIAS_LENGTH		79
+#else
+#define YAFFS_MAX_NAME_LENGTH		255
+#define YAFFS_MAX_ALIAS_LENGTH		159
+#endif
+
+#define YAFFS_SHORT_NAME_LENGTH		15
+
+/* Some special object ids for pseudo objects */
+#define YAFFS_OBJECTID_ROOT		1
+#define YAFFS_OBJECTID_LOSTNFOUND	2
+#define YAFFS_OBJECTID_UNLINKED		3
+#define YAFFS_OBJECTID_DELETED		4
+
+/* Sseudo object ids for checkpointing */
+#define YAFFS_OBJECTID_SB_HEADER	0x10
+#define YAFFS_OBJECTID_CHECKPOINT_DATA	0x20
+#define YAFFS_SEQUENCE_CHECKPOINT_DATA  0x21
+
+/* */
+
+#define YAFFS_MAX_SHORT_OP_CACHES	20
+
+#define YAFFS_N_TEMP_BUFFERS		4
+
+/* We limit the number attempts at sucessfully saving a chunk of data.
+ * Small-page devices have 32 pages per block; large-page devices have 64.
+ * Default to something in the order of 5 to 10 blocks worth of chunks.
+ */
+#define YAFFS_WR_ATTEMPTS		(5*64)
+
+/* Sequence numbers are used in YAFFS2 to determine block allocation order.
+ * The range is limited slightly to help distinguish bad numbers from good.
+ * This also allows us to perhaps in the future use special numbers for
+ * special purposes.
+ * EFFFFF00 allows the allocation of 8 blocks per second (~1Mbytes) for 15 years, 
+ * and is a larger number than the lifetime of a 2GB device.
+ */
+#define YAFFS_LOWEST_SEQUENCE_NUMBER	0x00001000
+#define YAFFS_HIGHEST_SEQUENCE_NUMBER	0xEFFFFF00
+
+/* ChunkCache is used for short read/write operations.*/
+typedef struct {
+	struct yaffs_ObjectStruct *object;
+	int chunkId;
+	int lastUse;
+	int dirty;
+	int nBytes;		/* Only valid if the cache is dirty */
+	int locked;		/* Can't push out or flush while locked. */
+#ifdef CONFIG_YAFFS_YAFFS2
+	__u8 *data;
+#else
+	__u8 data[YAFFS_BYTES_PER_CHUNK];
+#endif
+} yaffs_ChunkCache;
+
+
+
+/* Tags structures in RAM
+ * NB This uses bitfield. Bitfields should not straddle a u32 boundary otherwise
+ * the structure size will get blown out.
+ */
+
+#ifndef CONFIG_YAFFS_NO_YAFFS1
+typedef struct {
+	unsigned chunkId:20;
+	unsigned serialNumber:2;
+	unsigned byteCount:10;
+	unsigned objectId:18;
+	unsigned ecc:12;
+	unsigned unusedStuff:2;
+
+} yaffs_Tags;
+
+typedef union {
+	yaffs_Tags asTags;
+	__u8 asBytes[8];
+} yaffs_TagsUnion;
+
+#endif
+
+/* Stuff used for extended tags in YAFFS2 */
+
+typedef enum {
+	YAFFS_ECC_RESULT_UNKNOWN,
+	YAFFS_ECC_RESULT_NO_ERROR,
+	YAFFS_ECC_RESULT_FIXED,
+	YAFFS_ECC_RESULT_UNFIXED
+} yaffs_ECCResult;
+
+typedef enum {
+	YAFFS_OBJECT_TYPE_UNKNOWN,
+	YAFFS_OBJECT_TYPE_FILE,
+	YAFFS_OBJECT_TYPE_SYMLINK,
+	YAFFS_OBJECT_TYPE_DIRECTORY,
+	YAFFS_OBJECT_TYPE_HARDLINK,
+	YAFFS_OBJECT_TYPE_SPECIAL
+} yaffs_ObjectType;
+
+#define YAFFS_OBJECT_TYPE_MAX YAFFS_OBJECT_TYPE_SPECIAL
+
+typedef struct {
+
+	unsigned validMarker0;
+	unsigned chunkUsed;	/*  Status of the chunk: used or unused */
+	unsigned objectId;	/* If 0 then this is not part of an object (unused) */
+	unsigned chunkId;	/* If 0 then this is a header, else a data chunk */
+	unsigned byteCount;	/* Only valid for data chunks */
+
+	/* The following stuff only has meaning when we read */
+	yaffs_ECCResult eccResult;
+	unsigned blockBad;	
+
+	/* YAFFS 1 stuff */
+	unsigned chunkDeleted;	/* The chunk is marked deleted */
+	unsigned serialNumber;	/* Yaffs1 2-bit serial number */
+
+	/* YAFFS2 stuff */
+	unsigned sequenceNumber;	/* The sequence number of this block */
+
+	/* Extra info if this is an object header (YAFFS2 only) */
+
+	unsigned extraHeaderInfoAvailable;	/* There is extra info available if this is not zero */
+	unsigned extraParentObjectId;	/* The parent object */
+	unsigned extraIsShrinkHeader;	/* Is it a shrink header? */
+	unsigned extraShadows;		/* Does this shadow another object? */
+
+	yaffs_ObjectType extraObjectType;	/* What object type? */
+
+	unsigned extraFileLength;		/* Length if it is a file */
+	unsigned extraEquivalentObjectId;	/* Equivalent object Id if it is a hard link */
+
+	unsigned validMarker1;
+
+} yaffs_ExtendedTags;
+
+/* Spare structure for YAFFS1 */
+typedef struct {
+	__u8 tagByte0;
+	__u8 tagByte1;
+	__u8 tagByte2;
+	__u8 tagByte3;
+	__u8 pageStatus;	/* set to 0 to delete the chunk */
+	__u8 blockStatus;
+	__u8 tagByte4;
+	__u8 tagByte5;
+	__u8 ecc1[3];
+	__u8 tagByte6;
+	__u8 tagByte7;
+	__u8 ecc2[3];
+} yaffs_Spare;
+
+/*Special structure for passing through to mtd */
+struct yaffs_NANDSpare {
+	yaffs_Spare spare;
+	int eccres1;
+	int eccres2;
+};
+
+/* Block data in RAM */
+
+typedef enum {
+	YAFFS_BLOCK_STATE_UNKNOWN = 0,
+
+	YAFFS_BLOCK_STATE_SCANNING,
+	YAFFS_BLOCK_STATE_NEEDS_SCANNING,
+	/* The block might have something on it (ie it is allocating or full, perhaps empty)
+	 * but it needs to be scanned to determine its true state.
+	 * This state is only valid during yaffs_Scan.
+	 * NB We tolerate empty because the pre-scanner might be incapable of deciding
+	 * However, if this state is returned on a YAFFS2 device, then we expect a sequence number
+	 */
+
+	YAFFS_BLOCK_STATE_EMPTY,
+	/* This block is empty */
+
+	YAFFS_BLOCK_STATE_ALLOCATING,
+	/* This block is partially allocated. 
+	 * At least one page holds valid data.
+	 * This is the one currently being used for page
+	 * allocation. Should never be more than one of these
+	 */
+
+	YAFFS_BLOCK_STATE_FULL,	
+	/* All the pages in this block have been allocated.
+	 */
+
+	YAFFS_BLOCK_STATE_DIRTY,
+	/* All pages have been allocated and deleted. 
+	 * Erase me, reuse me.
+	 */
+
+	YAFFS_BLOCK_STATE_CHECKPOINT,	
+	/* This block is assigned to holding checkpoint data.
+	 */
+
+	YAFFS_BLOCK_STATE_COLLECTING,	
+	/* This block is being garbage collected */
+
+	YAFFS_BLOCK_STATE_DEAD	
+	/* This block has failed and is not in use */
+} yaffs_BlockState;
+
+#define	YAFFS_NUMBER_OF_BLOCK_STATES (YAFFS_BLOCK_STATE_DEAD + 1)
+
+
+typedef struct {
+
+	int softDeletions:10;	/* number of soft deleted pages */
+	int pagesInUse:10;	/* number of pages in use */
+	unsigned blockState:4;	/* One of the above block states. NB use unsigned because enum is sometimes an int */
+	__u32 needsRetiring:1;	/* Data has failed on this block, need to get valid data off */
+                        	/* and retire the block. */
+	__u32 skipErasedCheck: 1; /* If this is set we can skip the erased check on this block */
+	__u32 gcPrioritise: 1; 	/* An ECC check or blank check has failed on this block. 
+				   It should be prioritised for GC */
+        __u32 chunkErrorStrikes:3; /* How many times we've had ecc etc failures on this block and tried to reuse it */
+
+#ifdef CONFIG_YAFFS_YAFFS2
+	__u32 hasShrinkHeader:1; /* This block has at least one shrink object header */
+	__u32 sequenceNumber;	 /* block sequence number for yaffs2 */
+#endif
+
+} yaffs_BlockInfo;
+
+/* -------------------------- Object structure -------------------------------*/
+/* This is the object structure as stored on NAND */
+
+typedef struct {
+	yaffs_ObjectType type;
+
+	/* Apply to everything  */
+	int parentObjectId;
+	__u16 sum__NoLongerUsed;	/* checksum of name. No longer used */
+	YCHAR name[YAFFS_MAX_NAME_LENGTH + 1];
+
+	/* Thes following apply to directories, files, symlinks - not hard links */
+	__u32 yst_mode;		/* protection */
+
+#ifdef CONFIG_YAFFS_WINCE
+	__u32 notForWinCE[5];
+#else
+	__u32 yst_uid;
+	__u32 yst_gid;
+	__u32 yst_atime;
+	__u32 yst_mtime;
+	__u32 yst_ctime;
+#endif
+
+	/* File size  applies to files only */
+	int fileSize;
+
+	/* Equivalent object id applies to hard links only. */
+	int equivalentObjectId;
+
+	/* Alias is for symlinks only. */
+	YCHAR alias[YAFFS_MAX_ALIAS_LENGTH + 1];
+
+	__u32 yst_rdev;		/* device stuff for block and char devices (major/min) */
+
+#ifdef CONFIG_YAFFS_WINCE
+	__u32 win_ctime[2];
+	__u32 win_atime[2];
+	__u32 win_mtime[2];
+	__u32 roomToGrow[4];
+#else
+	__u32 roomToGrow[10];
+#endif
+
+	int shadowsObject;	/* This object header shadows the specified object if > 0 */
+
+	/* isShrink applies to object headers written when we shrink the file (ie resize) */
+	__u32 isShrink;
+
+} yaffs_ObjectHeader;
+
+/*--------------------------- Tnode -------------------------- */
+
+union yaffs_Tnode_union {
+#ifdef CONFIG_YAFFS_TNODE_LIST_DEBUG
+	union yaffs_Tnode_union *internal[YAFFS_NTNODES_INTERNAL + 1];
+#else
+	union yaffs_Tnode_union *internal[YAFFS_NTNODES_INTERNAL];
+#endif
+/*	__u16 level0[YAFFS_NTNODES_LEVEL0]; */
+
+};
+
+typedef union yaffs_Tnode_union yaffs_Tnode;
+
+struct yaffs_TnodeList_struct {
+	struct yaffs_TnodeList_struct *next;
+	yaffs_Tnode *tnodes;
+};
+
+typedef struct yaffs_TnodeList_struct yaffs_TnodeList;
+
+/*------------------------  Object -----------------------------*/
+/* An object can be one of:
+ * - a directory (no data, has children links
+ * - a regular file (data.... not prunes :->).
+ * - a symlink [symbolic link] (the alias).
+ * - a hard link
+ */
+
+typedef struct {
+	__u32 fileSize;
+	__u32 scannedFileSize;
+	__u32 shrinkSize;
+	int topLevel;
+	yaffs_Tnode *top;
+} yaffs_FileStructure;
+
+typedef struct {
+	struct list_head children;	/* list of child links */
+} yaffs_DirectoryStructure;
+
+typedef struct {
+	YCHAR *alias;
+} yaffs_SymLinkStructure;
+
+typedef struct {
+	struct yaffs_ObjectStruct *equivalentObject;
+	__u32 equivalentObjectId;
+} yaffs_HardLinkStructure;
+
+typedef union {
+	yaffs_FileStructure fileVariant;
+	yaffs_DirectoryStructure directoryVariant;
+	yaffs_SymLinkStructure symLinkVariant;
+	yaffs_HardLinkStructure hardLinkVariant;
+} yaffs_ObjectVariant;
+
+struct yaffs_ObjectStruct {
+	__u8 deleted:1;		/* This should only apply to unlinked files. */
+	__u8 softDeleted:1;	/* it has also been soft deleted */
+	__u8 unlinked:1;	/* An unlinked file. The file should be in the unlinked directory.*/
+	__u8 fake:1;		/* A fake object has no presence on NAND. */
+	__u8 renameAllowed:1;	/* Some objects are not allowed to be renamed. */
+	__u8 unlinkAllowed:1;
+	__u8 dirty:1;		/* the object needs to be written to flash */
+	__u8 valid:1;		/* When the file system is being loaded up, this 
+				 * object might be created before the data
+				 * is available (ie. file data records appear before the header).
+				 */
+	__u8 lazyLoaded:1;	/* This object has been lazy loaded and is missing some detail */
+
+	__u8 deferedFree:1;	/* For Linux kernel. Object is removed from NAND, but is
+				 * still in the inode cache. Free of object is defered.
+				 * until the inode is released.
+				 */
+
+	__u8 serial;		/* serial number of chunk in NAND. Cached here */
+	__u16 sum;		/* sum of the name to speed searching */
+
+	struct yaffs_DeviceStruct *myDev;	/* The device I'm on */
+
+	struct list_head hashLink;	/* list of objects in this hash bucket */
+
+	struct list_head hardLinks;	/* all the equivalent hard linked objects */
+
+	/* directory structure stuff */
+	/* also used for linking up the free list */
+	struct yaffs_ObjectStruct *parent; 
+	struct list_head siblings;
+
+	/* Where's my object header in NAND? */
+	int chunkId;		
+
+	int nDataChunks;	/* Number of data chunks attached to the file. */
+
+	__u32 objectId;		/* the object id value */
+
+	__u32 yst_mode;
+
+#ifdef CONFIG_YAFFS_SHORT_NAMES_IN_RAM
+	YCHAR shortName[YAFFS_SHORT_NAME_LENGTH + 1];
+#endif
+
+#ifndef __KERNEL__
+	__u32 inUse;
+#endif
+
+#ifdef CONFIG_YAFFS_WINCE
+	__u32 win_ctime[2];
+	__u32 win_mtime[2];
+	__u32 win_atime[2];
+#else
+	__u32 yst_uid;
+	__u32 yst_gid;
+	__u32 yst_atime;
+	__u32 yst_mtime;
+	__u32 yst_ctime;
+#endif
+
+	__u32 yst_rdev;
+
+#ifdef __KERNEL__
+	struct inode *myInode;
+
+#endif
+
+	yaffs_ObjectType variantType;
+
+	yaffs_ObjectVariant variant;
+
+};
+
+typedef struct yaffs_ObjectStruct yaffs_Object;
+
+struct yaffs_ObjectList_struct {
+	yaffs_Object *objects;
+	struct yaffs_ObjectList_struct *next;
+};
+
+typedef struct yaffs_ObjectList_struct yaffs_ObjectList;
+
+typedef struct {
+	struct list_head list;
+	int count;
+} yaffs_ObjectBucket;
+
+
+/* yaffs_CheckpointObject holds the definition of an object as dumped 
+ * by checkpointing.
+ */
+
+typedef struct {
+        int structType;
+	__u32 objectId;		
+	__u32 parentId;
+	int chunkId;
+			
+	yaffs_ObjectType variantType:3;
+	__u8 deleted:1;		
+	__u8 softDeleted:1;	
+	__u8 unlinked:1;	
+	__u8 fake:1;		
+	__u8 renameAllowed:1;
+	__u8 unlinkAllowed:1;
+	__u8 serial;		
+	
+	int nDataChunks;	
+	__u32 fileSizeOrEquivalentObjectId;
+
+}yaffs_CheckpointObject;
+
+/*--------------------- Temporary buffers ----------------
+ *
+ * These are chunk-sized working buffers. Each device has a few
+ */
+
+typedef struct {
+	__u8 *buffer;
+	int line;	/* track from whence this buffer was allocated */
+	int maxLine;
+} yaffs_TempBuffer;
+
+/*----------------- Device ---------------------------------*/
+
+struct yaffs_DeviceStruct {
+	struct list_head devList;
+	const char *name;
+
+	/* Entry parameters set up way early. Yaffs sets up the rest.*/
+	int nDataBytesPerChunk;	/* Should be a power of 2 >= 512 */
+	int nChunksPerBlock;	/* does not need to be a power of 2 */
+	int nBytesPerSpare;	/* spare area size */
+	int startBlock;		/* Start block we're allowed to use */
+	int endBlock;		/* End block we're allowed to use */
+	int nReservedBlocks;	/* We want this tuneable so that we can reduce */
+				/* reserved blocks on NOR and RAM. */
+	
+	
+	/* Stuff used by the shared space checkpointing mechanism */
+	/* If this value is zero, then this mechanism is disabled */
+	
+	int nCheckpointReservedBlocks; /* Blocks to reserve for checkpoint data */
+
+	
+
+
+	int nShortOpCaches;	/* If <= 0, then short op caching is disabled, else
+				 * the number of short op caches (don't use too many)
+				 */
+
+	int useHeaderFileSize;	/* Flag to determine if we should use file sizes from the header */
+
+	int useNANDECC;		/* Flag to decide whether or not to use NANDECC */
+
+	void *genericDevice;	/* Pointer to device context
+				 * On an mtd this holds the mtd pointer.
+				 */
+        void *superBlock;
+        
+	/* NAND access functions (Must be set before calling YAFFS)*/
+
+	int (*writeChunkToNAND) (struct yaffs_DeviceStruct * dev,
+				 int chunkInNAND, const __u8 * data,
+				 const yaffs_Spare * spare);
+	int (*readChunkFromNAND) (struct yaffs_DeviceStruct * dev,
+				  int chunkInNAND, __u8 * data,
+				  yaffs_Spare * spare);
+	int (*eraseBlockInNAND) (struct yaffs_DeviceStruct * dev,
+				 int blockInNAND);
+	int (*initialiseNAND) (struct yaffs_DeviceStruct * dev);
+
+#ifdef CONFIG_YAFFS_YAFFS2
+	int (*writeChunkWithTagsToNAND) (struct yaffs_DeviceStruct * dev,
+					 int chunkInNAND, const __u8 * data,
+					 const yaffs_ExtendedTags * tags);
+	int (*readChunkWithTagsFromNAND) (struct yaffs_DeviceStruct * dev,
+					  int chunkInNAND, __u8 * data,
+					  yaffs_ExtendedTags * tags);
+	int (*markNANDBlockBad) (struct yaffs_DeviceStruct * dev, int blockNo);
+	int (*queryNANDBlock) (struct yaffs_DeviceStruct * dev, int blockNo,
+			       yaffs_BlockState * state, int *sequenceNumber);
+#endif
+
+	int isYaffs2;
+	
+	/* The removeObjectCallback function must be supplied by OS flavours that 
+	 * need it. The Linux kernel does not use this, but yaffs direct does use
+	 * it to implement the faster readdir
+	 */
+	void (*removeObjectCallback)(struct yaffs_ObjectStruct *obj);
+	
+	/* Callback to mark the superblock dirsty */
+	void (*markSuperBlockDirty)(void * superblock);
+	
+	int wideTnodesDisabled; /* Set to disable wide tnodes */
+	
+
+	/* End of stuff that must be set before initialisation. */
+	
+	/* Checkpoint control. Can be set before or after initialisation */
+	__u8 skipCheckpointRead;
+	__u8 skipCheckpointWrite;
+
+	/* Runtime parameters. Set up by YAFFS. */
+
+	__u16 chunkGroupBits;	/* 0 for devices <= 32MB. else log2(nchunks) - 16 */
+	__u16 chunkGroupSize;	/* == 2^^chunkGroupBits */
+	
+	/* Stuff to support wide tnodes */
+	__u32 tnodeWidth;
+	__u32 tnodeMask;
+	
+	/* Stuff to support various file offses to chunk/offset translations */
+	/* "Crumbs" for nDataBytesPerChunk not being a power of 2 */
+	__u32 crumbMask;
+	__u32 crumbShift;
+	__u32 crumbsPerChunk;
+	
+	/* Straight shifting for nDataBytesPerChunk being a power of 2 */
+	__u32 chunkShift;
+	__u32 chunkMask;
+	
+
+#ifdef __KERNEL__
+
+	struct semaphore sem;	/* Semaphore for waiting on erasure.*/
+	struct semaphore grossLock;	/* Gross locking semaphore */
+	__u8 *spareBuffer;	/* For mtdif2 use. Don't know the size of the buffer 
+				 * at compile time so we have to allocate it.
+				 */
+	void (*putSuperFunc) (struct super_block * sb);
+#endif
+
+	int isMounted;
+	
+	int isCheckpointed;
+
+
+	/* Stuff to support block offsetting to support start block zero */
+	int internalStartBlock;
+	int internalEndBlock;
+	int blockOffset;
+	int chunkOffset;
+	
+
+	/* Runtime checkpointing stuff */
+	int checkpointPageSequence;   /* running sequence number of checkpoint pages */
+	int checkpointByteCount;
+	int checkpointByteOffset;
+	__u8 *checkpointBuffer;
+	int checkpointOpenForWrite;
+	int blocksInCheckpoint;
+	int checkpointCurrentChunk;
+	int checkpointCurrentBlock;
+	int checkpointNextBlock;
+	int *checkpointBlockList;
+	int checkpointMaxBlocks;
+	__u32 checkpointSum;
+	__u32 checkpointXor;
+	
+	/* Block Info */
+	yaffs_BlockInfo *blockInfo;
+	__u8 *chunkBits;	/* bitmap of chunks in use */
+	unsigned blockInfoAlt:1;	/* was allocated using alternative strategy */
+	unsigned chunkBitsAlt:1;	/* was allocated using alternative strategy */
+	int chunkBitmapStride;	/* Number of bytes of chunkBits per block. 
+				 * Must be consistent with nChunksPerBlock.
+				 */
+
+	int nErasedBlocks;
+	int allocationBlock;	/* Current block being allocated off */
+	__u32 allocationPage;
+	int allocationBlockFinder;	/* Used to search for next allocation block */
+
+	/* Runtime state */
+	int nTnodesCreated;
+	yaffs_Tnode *freeTnodes;
+	int nFreeTnodes;
+	yaffs_TnodeList *allocatedTnodeList;
+
+	int isDoingGC;
+
+	int nObjectsCreated;
+	yaffs_Object *freeObjects;
+	int nFreeObjects;
+
+	yaffs_ObjectList *allocatedObjectList;
+
+	yaffs_ObjectBucket objectBucket[YAFFS_NOBJECT_BUCKETS];
+
+	int nFreeChunks;
+
+	int currentDirtyChecker;	/* Used to find current dirtiest block */
+
+	__u32 *gcCleanupList;	/* objects to delete at the end of a GC. */
+	int nonAggressiveSkip;	/* GC state/mode */
+
+	/* Statistcs */
+	int nPageWrites;
+	int nPageReads;
+	int nBlockErasures;
+	int nErasureFailures;
+	int nGCCopies;
+	int garbageCollections;
+	int passiveGarbageCollections;
+	int nRetriedWrites;
+	int nRetiredBlocks;
+	int eccFixed;
+	int eccUnfixed;
+	int tagsEccFixed;
+	int tagsEccUnfixed;
+	int nDeletions;
+	int nUnmarkedDeletions;
+	
+	int hasPendingPrioritisedGCs; /* We think this device might have pending prioritised gcs */
+
+	/* Special directories */
+	yaffs_Object *rootDir;
+	yaffs_Object *lostNFoundDir;
+
+	/* Buffer areas for storing data to recover from write failures TODO
+	 *      __u8            bufferedData[YAFFS_CHUNKS_PER_BLOCK][YAFFS_BYTES_PER_CHUNK];
+	 *      yaffs_Spare bufferedSpare[YAFFS_CHUNKS_PER_BLOCK];
+	 */
+	
+	int bufferedBlock;	/* Which block is buffered here? */
+	int doingBufferedBlockRewrite;
+
+	yaffs_ChunkCache *srCache;
+	int srLastUse;
+
+	int cacheHits;
+
+	/* Stuff for background deletion and unlinked files.*/
+	yaffs_Object *unlinkedDir;	/* Directory where unlinked and deleted files live. */
+	yaffs_Object *deletedDir;	/* Directory where deleted objects are sent to disappear. */
+	yaffs_Object *unlinkedDeletion;	/* Current file being background deleted.*/
+	int nDeletedFiles;		/* Count of files awaiting deletion;*/
+	int nUnlinkedFiles;		/* Count of unlinked files. */
+	int nBackgroundDeletions;	/* Count of background deletions. */
+
+
+	yaffs_TempBuffer tempBuffer[YAFFS_N_TEMP_BUFFERS];
+	int maxTemp;
+	int unmanagedTempAllocations;
+	int unmanagedTempDeallocations;
+
+	/* yaffs2 runtime stuff */
+	unsigned sequenceNumber;	/* Sequence number of currently allocating block */
+	unsigned oldestDirtySequence;
+
+};
+
+typedef struct yaffs_DeviceStruct yaffs_Device;
+
+/* The static layout of bllock usage etc is stored in the super block header */
+typedef struct {
+        int StructType;
+	int version;
+	int checkpointStartBlock;
+	int checkpointEndBlock;
+	int startBlock;
+	int endBlock;
+	int rfu[100];
+} yaffs_SuperBlockHeader;
+	
+/* The CheckpointDevice structure holds the device information that changes at runtime and
+ * must be preserved over unmount/mount cycles.
+ */
+typedef struct {
+        int structType;
+	int nErasedBlocks;
+	int allocationBlock;	/* Current block being allocated off */
+	__u32 allocationPage;
+	int nFreeChunks;
+
+	int nDeletedFiles;		/* Count of files awaiting deletion;*/
+	int nUnlinkedFiles;		/* Count of unlinked files. */
+	int nBackgroundDeletions;	/* Count of background deletions. */
+
+	/* yaffs2 runtime stuff */
+	unsigned sequenceNumber;	/* Sequence number of currently allocating block */
+	unsigned oldestDirtySequence;
+
+} yaffs_CheckpointDevice;
+
+
+typedef struct {
+    int structType;
+    __u32 magic;
+    __u32 version;
+    __u32 head;
+} yaffs_CheckpointValidity;
+
+/* Function to manipulate block info */
+static Y_INLINE yaffs_BlockInfo *yaffs_GetBlockInfo(yaffs_Device * dev, int blk)
+{
+	if (blk < dev->internalStartBlock || blk > dev->internalEndBlock) {
+		T(YAFFS_TRACE_ERROR,
+		  (TSTR
+		   ("**>> yaffs: getBlockInfo block %d is not valid" TENDSTR),
+		   blk));
+		YBUG();
+	}
+	return &dev->blockInfo[blk - dev->internalStartBlock];
+}
+
+/*----------------------- YAFFS Functions -----------------------*/
+
+int yaffs_GutsInitialise(yaffs_Device * dev);
+void yaffs_Deinitialise(yaffs_Device * dev);
+
+int yaffs_GetNumberOfFreeChunks(yaffs_Device * dev);
+
+int yaffs_RenameObject(yaffs_Object * oldDir, const YCHAR * oldName,
+		       yaffs_Object * newDir, const YCHAR * newName);
+
+int yaffs_Unlink(yaffs_Object * dir, const YCHAR * name);
+int yaffs_DeleteFile(yaffs_Object * obj);
+
+int yaffs_GetObjectName(yaffs_Object * obj, YCHAR * name, int buffSize);
+int yaffs_GetObjectFileLength(yaffs_Object * obj);
+int yaffs_GetObjectInode(yaffs_Object * obj);
+unsigned yaffs_GetObjectType(yaffs_Object * obj);
+int yaffs_GetObjectLinkCount(yaffs_Object * obj);
+
+int yaffs_SetAttributes(yaffs_Object * obj, struct iattr *attr);
+int yaffs_GetAttributes(yaffs_Object * obj, struct iattr *attr);
+
+/* File operations */
+int yaffs_ReadDataFromFile(yaffs_Object * obj, __u8 * buffer, loff_t offset,
+			   int nBytes);
+int yaffs_WriteDataToFile(yaffs_Object * obj, const __u8 * buffer, loff_t offset,
+			  int nBytes, int writeThrough);
+int yaffs_ResizeFile(yaffs_Object * obj, loff_t newSize);
+
+yaffs_Object *yaffs_MknodFile(yaffs_Object * parent, const YCHAR * name,
+			      __u32 mode, __u32 uid, __u32 gid);
+int yaffs_FlushFile(yaffs_Object * obj, int updateTime);
+
+/* Flushing and checkpointing */
+void yaffs_FlushEntireDeviceCache(yaffs_Device *dev);
+
+int yaffs_CheckpointSave(yaffs_Device *dev);
+int yaffs_CheckpointRestore(yaffs_Device *dev);
+
+/* Directory operations */
+yaffs_Object *yaffs_MknodDirectory(yaffs_Object * parent, const YCHAR * name,
+				   __u32 mode, __u32 uid, __u32 gid);
+yaffs_Object *yaffs_FindObjectByName(yaffs_Object * theDir, const YCHAR * name);
+int yaffs_ApplyToDirectoryChildren(yaffs_Object * theDir,
+				   int (*fn) (yaffs_Object *));
+
+yaffs_Object *yaffs_FindObjectByNumber(yaffs_Device * dev, __u32 number);
+
+/* Link operations */
+yaffs_Object *yaffs_Link(yaffs_Object * parent, const YCHAR * name,
+			 yaffs_Object * equivalentObject);
+
+yaffs_Object *yaffs_GetEquivalentObject(yaffs_Object * obj);
+
+/* Symlink operations */
+yaffs_Object *yaffs_MknodSymLink(yaffs_Object * parent, const YCHAR * name,
+				 __u32 mode, __u32 uid, __u32 gid,
+				 const YCHAR * alias);
+YCHAR *yaffs_GetSymlinkAlias(yaffs_Object * obj);
+
+/* Special inodes (fifos, sockets and devices) */
+yaffs_Object *yaffs_MknodSpecial(yaffs_Object * parent, const YCHAR * name,
+				 __u32 mode, __u32 uid, __u32 gid, __u32 rdev);
+
+/* Special directories */
+yaffs_Object *yaffs_Root(yaffs_Device * dev);
+yaffs_Object *yaffs_LostNFound(yaffs_Device * dev);
+
+#ifdef CONFIG_YAFFS_WINCE
+/* CONFIG_YAFFS_WINCE special stuff */
+void yfsd_WinFileTimeNow(__u32 target[2]);
+#endif
+
+#ifdef __KERNEL__
+
+void yaffs_HandleDeferedFree(yaffs_Object * obj);
+#endif
+
+/* Debug dump  */
+int yaffs_DumpObject(yaffs_Object * obj);
+
+void yaffs_GutsTest(yaffs_Device * dev);
+
+/* A few useful functions */
+void yaffs_InitialiseTags(yaffs_ExtendedTags * tags);
+void yaffs_DeleteChunk(yaffs_Device * dev, int chunkId, int markNAND, int lyn);
+int yaffs_CheckFF(__u8 * buffer, int nBytes);
+void yaffs_HandleChunkError(yaffs_Device *dev, yaffs_BlockInfo *bi);
+
+#endif