yaffs_guts.c

yaffs2 source code for linux

		 
	if(nBlocksPerState[YAFFS_BLOCK_STATE_COLLECTING] > 1)
		T(YAFFS_TRACE_VERIFY,
		 (TSTR("Too many collecting blocks %d (max is 1)"TENDSTR),
		 nBlocksPerState[YAFFS_BLOCK_STATE_COLLECTING]));

	T(YAFFS_TRACE_VERIFY,(TSTR(""TENDSTR)));

}

/*
 * Verify the object header. oh must be valid, but obj and tags may be NULL in which
 * case those tests will not be performed.
 */
static void yaffs_VerifyObjectHeader(yaffs_Object *obj, yaffs_ObjectHeader *oh, yaffs_ExtendedTags *tags, int parentCheck)
{
	if(obj && yaffs_SkipVerification(obj->myDev))
		return;
		
	if(!(tags && obj && oh)){
	 	T(YAFFS_TRACE_VERIFY,
		 		(TSTR("Verifying object header tags %x obj %x oh %x"TENDSTR),
		 		(__u32)tags,(__u32)obj,(__u32)oh));
		return;
	}
	
	if(oh->type <= YAFFS_OBJECT_TYPE_UNKNOWN ||
	   oh->type > YAFFS_OBJECT_TYPE_MAX)
	 	T(YAFFS_TRACE_VERIFY,
		 (TSTR("Obj %d header type is illegal value 0x%x"TENDSTR),
		 tags->objectId, oh->type));

	if(tags->objectId != obj->objectId)
	 	T(YAFFS_TRACE_VERIFY,
		 (TSTR("Obj %d header mismatch objectId %d"TENDSTR),
		 tags->objectId, obj->objectId));


	/*
	 * Check that the object's parent ids match if parentCheck requested.
	 * 
	 * Tests do not apply to the root object.
	 */
	
	if(parentCheck && tags->objectId > 1 && !obj->parent)
	 	T(YAFFS_TRACE_VERIFY,
		 (TSTR("Obj %d header mismatch parentId %d obj->parent is NULL"TENDSTR),
	 	 tags->objectId, oh->parentObjectId));
		
	
	if(parentCheck && obj->parent &&
	   oh->parentObjectId != obj->parent->objectId && 
	   (oh->parentObjectId != YAFFS_OBJECTID_UNLINKED ||
	    obj->parent->objectId != YAFFS_OBJECTID_DELETED))
	 	T(YAFFS_TRACE_VERIFY,
		 (TSTR("Obj %d header mismatch parentId %d parentObjectId %d"TENDSTR),
	 	 tags->objectId, oh->parentObjectId, obj->parent->objectId));
		
	
	if(tags->objectId > 1 && oh->name[0] == 0) /* Null name */
		T(YAFFS_TRACE_VERIFY,
		(TSTR("Obj %d header name is NULL"TENDSTR),
		 obj->objectId));

	if(tags->objectId > 1 && ((__u8)(oh->name[0])) == 0xff) /* Trashed name */
		T(YAFFS_TRACE_VERIFY,
		(TSTR("Obj %d header name is 0xFF"TENDSTR),
		 obj->objectId));
}



static int yaffs_VerifyTnodeWorker(yaffs_Object * obj, yaffs_Tnode * tn,
				  	__u32 level, int chunkOffset)
{
	int i;
	yaffs_Device *dev = obj->myDev;
	int ok = 1;

	if (tn) {
		if (level > 0) {

			for (i = 0; i < YAFFS_NTNODES_INTERNAL && ok; i++){
				if (tn->internal[i]) {
					ok = yaffs_VerifyTnodeWorker(obj,
							tn->internal[i],
							level - 1,
							(chunkOffset<<YAFFS_TNODES_INTERNAL_BITS) + i);
				}
			}
		} else if (level == 0) {
			yaffs_ExtendedTags tags;
			__u32 objectId = obj->objectId;
			
			chunkOffset <<=  YAFFS_TNODES_LEVEL0_BITS;
			
			for(i = 0; i < YAFFS_NTNODES_LEVEL0; i++){
				__u32 theChunk = yaffs_GetChunkGroupBase(dev,tn,i);
				
				if(theChunk > 0){
					/* T(~0,(TSTR("verifying (%d:%d) %d"TENDSTR),tags.objectId,tags.chunkId,theChunk)); */
					yaffs_ReadChunkWithTagsFromNAND(dev,theChunk,NULL, &tags);
					if(tags.objectId != objectId || tags.chunkId != chunkOffset){
						T(~0,(TSTR("Object %d chunkId %d NAND mismatch chunk %d tags (%d:%d)"TENDSTR),
							objectId, chunkOffset, theChunk,
							tags.objectId, tags.chunkId));
					}
				}
				chunkOffset++;
			}
		}
	}

	return ok;

}


static void yaffs_VerifyFile(yaffs_Object *obj)
{
	int requiredTallness;
	int actualTallness;
	__u32 lastChunk;
	__u32 x;
	__u32 i;
	yaffs_Device *dev;
	yaffs_ExtendedTags tags;
	yaffs_Tnode *tn;
	__u32 objectId;
	
	if(!obj)
		return;

	if(yaffs_SkipVerification(obj->myDev))
		return;
	
	dev = obj->myDev;
	objectId = obj->objectId;
	
	/* Check file size is consistent with tnode depth */
	lastChunk =  obj->variant.fileVariant.fileSize / dev->nDataBytesPerChunk + 1;
	x = lastChunk >> YAFFS_TNODES_LEVEL0_BITS;
	requiredTallness = 0;
	while (x> 0) {
		x >>= YAFFS_TNODES_INTERNAL_BITS;
		requiredTallness++;
	}
	
	actualTallness = obj->variant.fileVariant.topLevel;
	
	if(requiredTallness > actualTallness )
		T(YAFFS_TRACE_VERIFY,
		(TSTR("Obj %d had tnode tallness %d, needs to be %d"TENDSTR),
		 obj->objectId,actualTallness, requiredTallness));
	
	
	/* Check that the chunks in the tnode tree are all correct. 
	 * We do this by scanning through the tnode tree and
	 * checking the tags for every chunk match.
	 */

	if(yaffs_SkipNANDVerification(dev))
		return;
		
	for(i = 1; i <= lastChunk; i++){
		tn = yaffs_FindLevel0Tnode(dev, &obj->variant.fileVariant,i);

		if (tn) {
			__u32 theChunk = yaffs_GetChunkGroupBase(dev,tn,i);
			if(theChunk > 0){
				/* T(~0,(TSTR("verifying (%d:%d) %d"TENDSTR),objectId,i,theChunk)); */
				yaffs_ReadChunkWithTagsFromNAND(dev,theChunk,NULL, &tags);
				if(tags.objectId != objectId || tags.chunkId != i){
					T(~0,(TSTR("Object %d chunkId %d NAND mismatch chunk %d tags (%d:%d)"TENDSTR),
						objectId, i, theChunk,
						tags.objectId, tags.chunkId));
				}
			}
		}

	}

}


static void yaffs_VerifyHardLink(yaffs_Object *obj)
{
	if(obj && yaffs_SkipVerification(obj->myDev))
		return;
		
	/* Verify sane equivalent object */
}

static void yaffs_VerifySymlink(yaffs_Object *obj)
{
	if(obj && yaffs_SkipVerification(obj->myDev))
		return;
		
	/* Verify symlink string */
}

static void yaffs_VerifySpecial(yaffs_Object *obj)
{
	if(obj && yaffs_SkipVerification(obj->myDev))
		return;
}

static void yaffs_VerifyObject(yaffs_Object *obj)
{
	yaffs_Device *dev;
	
	__u32 chunkMin;
	__u32 chunkMax;
	
	__u32 chunkIdOk;
	__u32 chunkIsLive;
	
	if(!obj)
		return;
	
	dev = obj->myDev;
	
	if(yaffs_SkipVerification(dev))
		return;
		
	/* Check sane object header chunk */

	chunkMin = dev->internalStartBlock * dev->nChunksPerBlock;
	chunkMax = (dev->internalEndBlock+1) * dev->nChunksPerBlock - 1;

	chunkIdOk = (((unsigned)(obj->hdrChunk)) >= chunkMin && ((unsigned)(obj->hdrChunk)) <= chunkMax);
	chunkIsLive = chunkIdOk &&
			yaffs_CheckChunkBit(dev,
					    obj->hdrChunk / dev->nChunksPerBlock,
					    obj->hdrChunk % dev->nChunksPerBlock);
	if(!obj->fake &&
	    (!chunkIdOk || !chunkIsLive)) {
	   T(YAFFS_TRACE_VERIFY,
	   (TSTR("Obj %d has chunkId %d %s %s"TENDSTR),
	   obj->objectId,obj->hdrChunk,
	   chunkIdOk ? "" : ",out of range",
	   chunkIsLive || !chunkIdOk ? "" : ",marked as deleted"));
	}
	
	if(chunkIdOk && chunkIsLive &&!yaffs_SkipNANDVerification(dev)) {
		yaffs_ExtendedTags tags;
		yaffs_ObjectHeader *oh;
		__u8 *buffer = yaffs_GetTempBuffer(dev,__LINE__);
		
		oh = (yaffs_ObjectHeader *)buffer;

		yaffs_ReadChunkWithTagsFromNAND(dev, obj->hdrChunk,buffer, &tags);

		yaffs_VerifyObjectHeader(obj,oh,&tags,1);
		
		yaffs_ReleaseTempBuffer(dev,buffer,__LINE__);
	}
	
	/* Verify it has a parent */
	if(obj && !obj->fake &&
	   (!obj->parent || obj->parent->myDev != dev)){
	   T(YAFFS_TRACE_VERIFY,
	   (TSTR("Obj %d has parent pointer %p which does not look like an object"TENDSTR),
	   obj->objectId,obj->parent));	   
	}
	
	/* Verify parent is a directory */
	if(obj->parent && obj->parent->variantType != YAFFS_OBJECT_TYPE_DIRECTORY){
	   T(YAFFS_TRACE_VERIFY,
	   (TSTR("Obj %d's parent is not a directory (type %d)"TENDSTR),
	   obj->objectId,obj->parent->variantType));	   
	}
	
	switch(obj->variantType){
	case YAFFS_OBJECT_TYPE_FILE:
		yaffs_VerifyFile(obj);
		break;
	case YAFFS_OBJECT_TYPE_SYMLINK:
		yaffs_VerifySymlink(obj);
		break;
	case YAFFS_OBJECT_TYPE_DIRECTORY:
		yaffs_VerifyDirectory(obj);
		break;
	case YAFFS_OBJECT_TYPE_HARDLINK:
		yaffs_VerifyHardLink(obj);
		break;
	case YAFFS_OBJECT_TYPE_SPECIAL:
		yaffs_VerifySpecial(obj);
		break;
	case YAFFS_OBJECT_TYPE_UNKNOWN:
	default:
		T(YAFFS_TRACE_VERIFY,
		(TSTR("Obj %d has illegaltype %d"TENDSTR),
		obj->objectId,obj->variantType));	   
		break;
	}
	
	
}

static void yaffs_VerifyObjects(yaffs_Device *dev)
{
        yaffs_Object *obj;
        int i;
        struct ylist_head *lh;

        if(yaffs_SkipVerification(dev))
                return;
	
        /* Iterate through the objects in each hash entry */
         
         for(i = 0; i <  YAFFS_NOBJECT_BUCKETS; i++){
                ylist_for_each(lh, &dev->objectBucket[i].list) {
                        if (lh) {
                                obj = ylist_entry(lh, yaffs_Object, hashLink);
                                yaffs_VerifyObject(obj);
                        }
                }
	 }

}


/*
 *  Simple hash function. Needs to have a reasonable spread
 */
 
static Y_INLINE int yaffs_HashFunction(int n)
{
	n = abs(n);
	return (n % YAFFS_NOBJECT_BUCKETS);
}

/*
 * Access functions to useful fake objects.
 * Note that root might have a presence in NAND if permissions are set.
 */
 
yaffs_Object *yaffs_Root(yaffs_Device * dev)
{
	return dev->rootDir;
}

yaffs_Object *yaffs_LostNFound(yaffs_Device * dev)
{
	return dev->lostNFoundDir;
}


/*
 *  Erased NAND checking functions
 */
 
int yaffs_CheckFF(__u8 * buffer, int nBytes)
{
	/* Horrible, slow implementation */
	while (nBytes--) {
		if (*buffer != 0xFF)
			return 0;
		buffer++;
	}
	return 1;
}

static int yaffs_CheckChunkErased(struct yaffs_DeviceStruct *dev,
				  int chunkInNAND)
{

	int retval = YAFFS_OK;
	__u8 *data = yaffs_GetTempBuffer(dev, __LINE__);
	yaffs_ExtendedTags tags;
	int result;

	result = yaffs_ReadChunkWithTagsFromNAND(dev, chunkInNAND, data, &tags);
	
	if(tags.eccResult > YAFFS_ECC_RESULT_NO_ERROR)
		retval = YAFFS_FAIL;
		

	if (!yaffs_CheckFF(data, dev->nDataBytesPerChunk) || tags.chunkUsed) {
		T(YAFFS_TRACE_NANDACCESS,
		  (TSTR("Chunk %d not erased" TENDSTR), chunkInNAND));
		retval = YAFFS_FAIL;
	}

	yaffs_ReleaseTempBuffer(dev, data, __LINE__);

	return retval;

}

static int yaffs_WriteNewChunkWithTagsToNAND(struct yaffs_DeviceStruct *dev,
					     const __u8 * data,
					     yaffs_ExtendedTags * tags,
					     int useReserve)
{
	int attempts = 0;
	int writeOk = 0;
	int chunk;

	yaffs_InvalidateCheckpoint(dev);

	do {
		yaffs_BlockInfo *bi = 0;
		int erasedOk = 0;

		chunk = yaffs_AllocateChunk(dev, useReserve, &bi);
		if (chunk < 0) {
			/* no space */
			break;
		}

		/* First check this chunk is erased, if it needs
		 * checking.  The checking policy (unless forced
		 * always on) is as follows:
		 *
		 * Check the first page we try to write in a block.
		 * If the check passes then we don't need to check any
		 * more.	If the check fails, we check again...
		 * If the block has been erased, we don't need to check.
		 *
		 * However, if the block has been prioritised for gc,
		 * then we think there might be something odd about
		 * this block and stop using it.
		 *
		 * Rationale: We should only ever see chunks that have
		 * not been erased if there was a partially written
		 * chunk due to power loss.  This checking policy should
		 * catch that case with very few checks and thus save a
		 * lot of checks that are most likely not needed.
		 */
		if (bi->gcPrioritise) {
			yaffs_DeleteChunk(dev, chunk, 1, __LINE__);
			/* try another chunk */
			continue;
		}

		/* let's give it a try */
		attempts++;

#ifdef CONFIG_YAFFS_ALWAYS_CHECK_CHUNK_ERASED
		bi->skipErasedCheck = 0;
#endif
		if (!bi->skipErasedCheck) {
			erasedOk = yaffs_CheckChunkErased(dev, chunk);
			if (erasedOk != YAFFS_OK) {
				T(YAFFS_TRACE_ERROR,
				(TSTR ("**>> yaffs chunk %d was not erased"
				TENDSTR), chunk));

				/* try another chunk */
				continue;
			}
			bi->skipErasedCheck = 1;
		}

		writeOk = yaffs_WriteChunkWithTagsToNAND(dev, chunk,
				data, tags);
		if (writeOk != YAFFS_OK) {
			yaffs_HandleWriteChunkError(dev, chunk, erasedOk);
			/* try another chunk */
			continue;
		}

		/* Copy the data into the robustification buffer */
		yaffs_HandleWriteChunkOk(dev, chunk, data, tags);

	} while (writeOk != YAFFS_OK && 
	        (yaffs_wr_attempts <= 0 || attempts <= yaffs_wr_attempts));
	
	if(!writeOk)
		chunk = -1;

	if (attempts > 1) {
		T(YAFFS_TRACE_ERROR,
			(TSTR("**>> yaffs write required %d attempts" TENDSTR),
			attempts));

		dev->nRetriedWrites += (attempts - 1);
	}

	return chunk;
}

/*
 * Block retiring for handling a broken block.
 */
 
static void yaffs_RetireBlock(yaffs_Device * dev, int blockInNAND)
{
	yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, blockInNAND);

	yaffs_InvalidateCheckpoint(dev);
	
	yaffs_MarkBlockBad(dev, blockInNAND);

	bi->blockState = YAFFS_BLOCK_STATE_DEAD;
	bi->gcPrioritise = 0;
	bi->needsRetiring = 0;

	dev->nRetiredBlocks++;
}

/*
 * Functions for robustisizing TODO
 *
 */
 
static void yaffs_HandleWriteChunkOk(yaffs_Device * dev, int chunkInNAND,
				     const __u8 * data,
				     const yaffs_ExtendedTags * tags)
{
}

static void yaffs_HandleUpdateChunk(yaffs_Device * dev, int chunkInNAND,
				    const yaffs_ExtendedTags * tags)
{
}

void yaffs_HandleChunkError(yaffs_Device *dev, yaffs_BlockInfo *bi)
{
	if(!bi->gcPrioritise){
		bi->gcPrioritise = 1;
		dev->hasPendingPrioritisedGCs = 1;
		bi->chunkErrorStrikes ++;
		
		if(bi->chunkErrorStrikes > 3){
			bi->needsRetiring = 1; /* Too many stikes, so retire this */
			T(YAFFS_TRACE_ALWAYS, (TSTR("yaffs: Block struck out" TENDSTR)));

		}
		
	}
}

static void yaffs_HandleWriteChunkError(yaffs_Device * dev, int chunkInNAND, int erasedOk)
{