yaffs_guts.h

这是ARM yaffs文件系统

#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