yaffs_guts.c

yaffs2

{
	return yaffs_MknodObject(YAFFS_OBJECT_TYPE_FILE, parent, name, mode,
				 uid, gid, NULL, NULL, 0);
}

yaffs_Object *yaffs_MknodDirectory(yaffs_Object * parent, const YCHAR * name,
				   __u32 mode, __u32 uid, __u32 gid)
{
	return yaffs_MknodObject(YAFFS_OBJECT_TYPE_DIRECTORY, parent, name,
				 mode, uid, gid, NULL, NULL, 0);
}

yaffs_Object *yaffs_MknodSpecial(yaffs_Object * parent, const YCHAR * name,
				 __u32 mode, __u32 uid, __u32 gid, __u32 rdev)
{
	return yaffs_MknodObject(YAFFS_OBJECT_TYPE_SPECIAL, parent, name, mode,
				 uid, gid, NULL, NULL, rdev);
}

yaffs_Object *yaffs_MknodSymLink(yaffs_Object * parent, const YCHAR * name,
				 __u32 mode, __u32 uid, __u32 gid,
				 const YCHAR * alias)
{
	return yaffs_MknodObject(YAFFS_OBJECT_TYPE_SYMLINK, parent, name, mode,
				 uid, gid, NULL, alias, 0);
}

/* yaffs_Link returns the object id of the equivalent object.*/
yaffs_Object *yaffs_Link(yaffs_Object * parent, const YCHAR * name,
			 yaffs_Object * equivalentObject)
{
	/* Get the real object in case we were fed a hard link as an equivalent object */
	equivalentObject = yaffs_GetEquivalentObject(equivalentObject);

	if (yaffs_MknodObject
	    (YAFFS_OBJECT_TYPE_HARDLINK, parent, name, 0, 0, 0,
	     equivalentObject, NULL, 0)) {
		return equivalentObject;
	} else {
		return NULL;
	}

}

static int yaffs_ChangeObjectName(yaffs_Object * obj, yaffs_Object * newDir,
				  const YCHAR * newName, int force, int shadows)
{
	int unlinkOp;
	int deleteOp;

	yaffs_Object *existingTarget;

	if (newDir == NULL) {
		newDir = obj->parent;	/* use the old directory */
	}

	if (newDir->variantType != YAFFS_OBJECT_TYPE_DIRECTORY) {
		T(YAFFS_TRACE_ALWAYS,
		  (TSTR
		   ("tragendy: yaffs_ChangeObjectName: newDir is not a directory"
		    TENDSTR)));
		YBUG();
	}
	
	/* TODO: Do we need this different handling for YAFFS2 and YAFFS1?? */
	if (obj->myDev->isYaffs2) {
		unlinkOp = (newDir == obj->myDev->unlinkedDir);
	} else {
		unlinkOp = (newDir == obj->myDev->unlinkedDir
			    && obj->variantType == YAFFS_OBJECT_TYPE_FILE);
	}

	deleteOp = (newDir == obj->myDev->deletedDir);

	existingTarget = yaffs_FindObjectByName(newDir, newName);

	/* If the object is a file going into the unlinked directory, 
	 *   then it is OK to just stuff it in since duplicate names are allowed.
	 *   else only proceed if the new name does not exist and if we're putting 
	 *   it into a directory.
	 */
	if ((unlinkOp ||
	     deleteOp ||
	     force ||
	     (shadows > 0) ||
	     !existingTarget) &&
	    newDir->variantType == YAFFS_OBJECT_TYPE_DIRECTORY) {
		yaffs_SetObjectName(obj, newName);
		obj->dirty = 1;

		yaffs_AddObjectToDirectory(newDir, obj);

		if (unlinkOp)
			obj->unlinked = 1;

		/* If it is a deletion then we mark it as a shrink for gc purposes. */
		if (yaffs_UpdateObjectHeader(obj, newName, 0, deleteOp, shadows)>= 0)
			return YAFFS_OK;
	}

	return YAFFS_FAIL;
}

int yaffs_RenameObject(yaffs_Object * oldDir, const YCHAR * oldName,
		       yaffs_Object * newDir, const YCHAR * newName)
{
	yaffs_Object *obj;
	yaffs_Object *existingTarget;
	int force = 0;

#ifdef CONFIG_YAFFS_CASE_INSENSITIVE
	/* Special case for case insemsitive systems (eg. WinCE).
	 * While look-up is case insensitive, the name isn't.
	 * Therefore we might want to change x.txt to X.txt
	*/
	if (oldDir == newDir && yaffs_strcmp(oldName, newName) == 0) {
		force = 1;
	}
#endif

	obj = yaffs_FindObjectByName(oldDir, oldName);
	/* Check new name to long. */
	if (obj->variantType == YAFFS_OBJECT_TYPE_SYMLINK &&
	    yaffs_strlen(newName) > YAFFS_MAX_ALIAS_LENGTH)
	  /* ENAMETOOLONG */
	  return YAFFS_FAIL;
	else if (obj->variantType != YAFFS_OBJECT_TYPE_SYMLINK &&
		 yaffs_strlen(newName) > YAFFS_MAX_NAME_LENGTH)
	  /* ENAMETOOLONG */
	  return YAFFS_FAIL;

	if (obj && obj->renameAllowed) {

		/* Now do the handling for an existing target, if there is one */

		existingTarget = yaffs_FindObjectByName(newDir, newName);
		if (existingTarget &&
		    existingTarget->variantType == YAFFS_OBJECT_TYPE_DIRECTORY &&
		    !list_empty(&existingTarget->variant.directoryVariant.children)) {
			/* There is a target that is a non-empty directory, so we fail */
			return YAFFS_FAIL;	/* EEXIST or ENOTEMPTY */
		} else if (existingTarget && existingTarget != obj) {
			/* Nuke the target first, using shadowing, 
			 * but only if it isn't the same object
			 */
			yaffs_ChangeObjectName(obj, newDir, newName, force,
					       existingTarget->objectId);
			yaffs_UnlinkObject(existingTarget);
		}

		return yaffs_ChangeObjectName(obj, newDir, newName, 1, 0);
	}
	return YAFFS_FAIL;
}

/*------------------------- Block Management and Page Allocation ----------------*/

static int yaffs_InitialiseBlocks(yaffs_Device * dev)
{
	int nBlocks = dev->internalEndBlock - dev->internalStartBlock + 1;
	
	dev->allocationBlock = -1;	/* force it to get a new one */

	/* Todo we're assuming the malloc will pass. */
	dev->blockInfo = YMALLOC(nBlocks * sizeof(yaffs_BlockInfo));
	if(!dev->blockInfo){
		dev->blockInfo = YMALLOC_ALT(nBlocks * sizeof(yaffs_BlockInfo));
		dev->blockInfoAlt = 1;
	}
	else
		dev->blockInfoAlt = 0;
	
	/* Set up dynamic blockinfo stuff. */
	dev->chunkBitmapStride = (dev->nChunksPerBlock + 7) / 8; // round up bytes
	dev->chunkBits = YMALLOC(dev->chunkBitmapStride * nBlocks);
	if(!dev->chunkBits){
		dev->chunkBits = YMALLOC_ALT(dev->chunkBitmapStride * nBlocks);
		dev->chunkBitsAlt = 1;
	}
	else
		dev->chunkBitsAlt = 0;
	
	if (dev->blockInfo && dev->chunkBits) {
		memset(dev->blockInfo, 0, nBlocks * sizeof(yaffs_BlockInfo));
		memset(dev->chunkBits, 0, dev->chunkBitmapStride * nBlocks);
		return YAFFS_OK;
	}

	return YAFFS_FAIL;

}

static void yaffs_DeinitialiseBlocks(yaffs_Device * dev)
{
	if(dev->blockInfoAlt)
		YFREE_ALT(dev->blockInfo);
	else
		YFREE(dev->blockInfo);
	dev->blockInfoAlt = 0;

	dev->blockInfo = NULL;
	
	if(dev->chunkBitsAlt)
		YFREE_ALT(dev->chunkBits);
	else
		YFREE(dev->chunkBits);
	dev->chunkBitsAlt = 0;
	dev->chunkBits = NULL;
}

static int yaffs_BlockNotDisqualifiedFromGC(yaffs_Device * dev,
					    yaffs_BlockInfo * bi)
{
	int i;
	__u32 seq;
	yaffs_BlockInfo *b;

	if (!dev->isYaffs2)
		return 1;	/* disqualification only applies to yaffs2. */

	if (!bi->hasShrinkHeader)
		return 1;	/* can gc */

	/* Find the oldest dirty sequence number if we don't know it and save it
	 * so we don't have to keep recomputing it.
	 */
	if (!dev->oldestDirtySequence) {
		seq = dev->sequenceNumber;

		for (i = dev->internalStartBlock; i <= dev->internalEndBlock;
		     i++) {
			b = yaffs_GetBlockInfo(dev, i);
			if (b->blockState == YAFFS_BLOCK_STATE_FULL &&
			    (b->pagesInUse - b->softDeletions) <
			    dev->nChunksPerBlock && b->sequenceNumber < seq) {
				seq = b->sequenceNumber;
			}
		}
		dev->oldestDirtySequence = seq;
	}

	/* Can't do gc of this block if there are any blocks older than this one that have
	 * discarded pages.
	 */
	return (bi->sequenceNumber <= dev->oldestDirtySequence);

	return 1;

}

/* FindDiretiestBlock is used to select the dirtiest block (or close enough)
 * for garbage collection.
 */

static int yaffs_FindBlockForGarbageCollection(yaffs_Device * dev,
					       int aggressive)
{

	int b = dev->currentDirtyChecker;

	int i;
	int iterations;
	int dirtiest = -1;
	int pagesInUse;
	yaffs_BlockInfo *bi;
	static int nonAggressiveSkip = 0;

	/* If we're doing aggressive GC then we are happy to take a less-dirty block, and
	 * search harder.
	 * else (we're doing a leasurely gc), then we only bother to do this if the
	 * block has only a few pages in use.
	 */

	nonAggressiveSkip--;

	if (!aggressive && (nonAggressiveSkip > 0)) {
		return -1;
	}

	pagesInUse =
	    (aggressive) ? dev->nChunksPerBlock : YAFFS_PASSIVE_GC_CHUNKS + 1;

	if (aggressive) {
		iterations =
		    dev->internalEndBlock - dev->internalStartBlock + 1;
	} else {
		iterations =
		    dev->internalEndBlock - dev->internalStartBlock + 1;
		iterations = iterations / 16;
		if (iterations > 200) {
			iterations = 200;
		}
	}

	for (i = 0; i <= iterations && pagesInUse > 0; i++) {
		b++;
		if (b < dev->internalStartBlock || b > dev->internalEndBlock) {
			b = dev->internalStartBlock;
		}

		if (b < dev->internalStartBlock || b > dev->internalEndBlock) {
			T(YAFFS_TRACE_ERROR,
			  (TSTR("**>> Block %d is not valid" TENDSTR), b));
			YBUG();
		}

		bi = yaffs_GetBlockInfo(dev, b);

#if 0
		if (bi->blockState == YAFFS_BLOCK_STATE_CHECKPOINT) {
			dirtiest = b;
			pagesInUse = 0;
		}
		else 
#endif

		if (bi->blockState == YAFFS_BLOCK_STATE_FULL &&
		      (bi->pagesInUse - bi->softDeletions) < pagesInUse &&
		        yaffs_BlockNotDisqualifiedFromGC(dev, bi)) {
			dirtiest = b;
			pagesInUse = (bi->pagesInUse - bi->softDeletions);
		}
	}

	dev->currentDirtyChecker = b;

	if (dirtiest > 0) {
		T(YAFFS_TRACE_GC,
		  (TSTR("GC Selected block %d with %d free" TENDSTR), dirtiest,
		   dev->nChunksPerBlock - pagesInUse));
	}

	dev->oldestDirtySequence = 0;

	if (dirtiest > 0) {
		nonAggressiveSkip = 4;
	}

	return dirtiest;
}

static void yaffs_BlockBecameDirty(yaffs_Device * dev, int blockNo)
{
	yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, blockNo);

	int erasedOk = 0;

	/* If the block is still healthy erase it and mark as clean.
	 * If the block has had a data failure, then retire it.
	 */
	bi->blockState = YAFFS_BLOCK_STATE_DIRTY;

	if (!bi->needsRetiring) {
		yaffs_InvalidateCheckpoint(dev);
		erasedOk = yaffs_EraseBlockInNAND(dev, blockNo);
		if (!erasedOk) {
			dev->nErasureFailures++;
			T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
			  (TSTR("**>> Erasure failed %d" TENDSTR), blockNo));
		}
	}

	if (erasedOk && (yaffs_traceMask & YAFFS_TRACE_ERASE)) {
		int i;
		for (i = 0; i < dev->nChunksPerBlock; i++) {
			if (!yaffs_CheckChunkErased
			    (dev, blockNo * dev->nChunksPerBlock + i)) {
				T(YAFFS_TRACE_ERROR,
				  (TSTR
				   (">>Block %d erasure supposedly OK, but chunk %d not erased"
				    TENDSTR), blockNo, i));
			}
		}
	}

	if (erasedOk) {
		/* Clean it up... */
		bi->blockState = YAFFS_BLOCK_STATE_EMPTY;
		dev->nErasedBlocks++;
		bi->pagesInUse = 0;
		bi->softDeletions = 0;
		bi->hasShrinkHeader = 0;
		yaffs_ClearChunkBits(dev, blockNo);

		T(YAFFS_TRACE_ERASE,
		  (TSTR("Erased block %d" TENDSTR), blockNo));
	} else {
		dev->nFreeChunks -= dev->nChunksPerBlock;	/* We lost a block of free space */

		yaffs_RetireBlock(dev, blockNo);
		T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
		  (TSTR("**>> Block %d retired" TENDSTR), blockNo));
	}
}

static int yaffs_FindBlockForAllocation(yaffs_Device * dev)
{
	int i;

	yaffs_BlockInfo *bi;

	if (dev->nErasedBlocks < 1) {
		/* Hoosterman we've got a problem.
		 * Can't get space to gc
		 */
		T(YAFFS_TRACE_ERROR,
		  (TSTR("yaffs tragedy: no more eraased blocks" TENDSTR)));

		return -1;
	}
	
	/* Find an empty block. */

	for (i = dev->internalStartBlock; i <= dev->internalEndBlock; i++) {
		dev->allocationBlockFinder++;
		if (dev->allocationBlockFinder < dev->internalStartBlock
		    || dev->allocationBlockFinder > dev->internalEndBlock) {
			dev->allocationBlockFinder = dev->internalStartBlock;
		}

		bi = yaffs_GetBlockInfo(dev, dev->allocationBlockFinder);

		if (bi->blockState == YAFFS_BLOCK_STATE_EMPTY) {
			bi->blockState = YAFFS_BLOCK_STATE_ALLOCATING;
			dev->sequenceNumber++;
			bi->sequenceNumber = dev->sequenceNumber;
			dev->nErasedBlocks--;
			T(YAFFS_TRACE_ALLOCATE,
			  (TSTR("Allocated block %d, seq  %d, %d left" TENDSTR),
			   dev->allocationBlockFinder, dev->sequenceNumber,
			   dev->nErasedBlocks));
			return dev->allocationBlockFinder;
		}
	}

	T(YAFFS_TRACE_ALWAYS,
	  (TSTR
	   ("yaffs tragedy: no more eraased blocks, but there should have been %d"
	    TENDSTR), dev->nErasedBlocks));

	return -1;
}


// Check if there's space to allocate...
// Thinks.... do we need top make this ths same as yaffs_GetFreeChunks()?
static int yaffs_CheckSpaceForAllocation(yaffs_Device * dev)
{
	int reservedChunks;
	int reservedBlocks = dev->nReservedBlocks;
	int checkpointBlocks;
	
	checkpointBlocks =  dev->nCheckpointReservedBlocks - dev->blocksInCheckpoint;
	if(checkpointBlocks < 0)
		checkpointBlocks = 0;
	
	reservedChunks = ((reservedBlocks + checkpointBlocks) * dev->nChunksPerBlock);
	
	return (dev->nFreeChunks > reservedChunks);
}

static int yaffs_AllocateChunk(yaffs_Device * dev, int useReserve)
{
	int retVal;
	yaffs_BlockInfo *bi;

	if (dev->allocationBlock < 0) {
		/* Get next block to allocate off */
		dev->allocationBlock = yaffs_FindBlockForAllocation(dev);
		dev->allocationPage = 0;
	}

	if (!useReserve && !yaffs_CheckSpaceForAllocation(dev)) {
		/* Not enough space to allocate unless we're allowed to use the reserve. */
		return -1;
	}

	if (dev->nErasedBlocks < dev->nReservedBlocks
	    && dev->allocationPage == 0) {
		T(YAFFS_TRACE_ALLOCATE, (TSTR("Allocating reserve" TENDSTR)));
	}

	/* Next page please.... */
	if (dev->allocationBlock >= 0) {
		bi = yaffs_GetBlockInfo(dev, dev->allocationBlock);

		retVal = (dev->allocationBlock * dev->nChunksPerBlock) +
		    dev->allocationPage;
		bi->pagesInUse++;
		yaffs_SetChunkBit(dev, dev->allocationBlock,
				  dev->allocationPage);

		dev->allocationPage++;

		dev->nFreeChunks--;

		/* If the block is full set the state to full */
		if (dev->allocationPage >= dev->nChunksPerBlock) {
			bi->blockState = YAFFS_BLOCK_STATE_FULL;
			dev->allocationBlock = -1;
		}

		return retVal;
	}
	
	T(YAFFS_TRACE_ERROR,
	  (TSTR("!!!!!!!!! Allocator out !!!!!!!!!!!!!!!!!" TENDSTR)));

	return -1;
}

static int yaffs_GetErasedChunks(yaffs_Device * dev)
{
	int n;

	n = dev->nErasedBlocks * dev->nChunksPerBlock;

	if (dev->allocationBlock > 0) {
		n += (dev->nChunksPerBlock - dev->allocationPage);
	}

	return n;

}

static int yaffs_GarbageCollectBlock(yaffs_Device * dev, int block)
{
	int oldChunk;
	int newChunk;
	int chunkInBlock;
	int markNAND;
	int retVal = YAFFS_OK;
	int cleanups = 0;
	int i;
	int isCheckpointBlock;

	int chunksBefore = yaffs_GetErasedChunks(dev);
	int chunksAfter;

	yaffs_ExtendedTags tags;

	yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, block);

	yaffs_Object *object;