/*
 * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
 *
 * Copyright (C) 2002-2010 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 General Public License version 2 as
 * published by the Free Software Foundation.
 */


#include "yaffs_guts.h"
#include "yaffs_trace.h"
#include "yaffs_yaffs2.h"
#include "yaffs_checkptrw.h"
#include "yaffs_bitmap.h"
#include "yaffs_qsort.h"
#include "yaffs_nand.h"
#include "yaffs_getblockinfo.h"
#include "yaffs_verify.h"

/*
 * Checkpoints are really no benefit on very small partitions.
 *
 * To save space on small partitions don't bother with checkpoints unless
 * the partition is at least this big.
 */
#define YAFFS_CHECKPOINT_MIN_BLOCKS 60

#define YAFFS_SMALL_HOLE_THRESHOLD 4


/*
 * Oldest Dirty Sequence Number handling.
 */
 
/* yaffs_calc_oldest_dirty_seq()
 * yaffs2_find_oldest_dirty_seq()
 * Calculate the oldest dirty sequence number if we don't know it.
 */
void yaffs_calc_oldest_dirty_seq(yaffs_dev_t *dev)
{
	int i;
	unsigned seq;
	unsigned block_no = 0;
	yaffs_block_info_t *b;

	if(!dev->param.is_yaffs2)
		return;

	/* Find the oldest dirty sequence number. */
	seq = dev->seq_number + 1;
	b = dev->block_info;
	for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
		if (b->block_state == YAFFS_BLOCK_STATE_FULL &&
			(b->pages_in_use - b->soft_del_pages) < dev->param.chunks_per_block &&
			b->seq_number < seq) {
			seq = b->seq_number;
			block_no = i;
		}
		b++;
	}

	if(block_no){
		dev->oldest_dirty_seq = seq;
		dev->oldest_dirty_block = block_no;
	}

}


void yaffs2_find_oldest_dirty_seq(yaffs_dev_t *dev)
{
	if(!dev->param.is_yaffs2)
		return;

	if(!dev->oldest_dirty_seq)
		yaffs_calc_oldest_dirty_seq(dev);
}

/*
 * yaffs_clear_oldest_dirty_seq()
 * Called when a block is erased or marked bad. (ie. when its seq_number
 * becomes invalid). If the value matches the oldest then we clear 
 * dev->oldest_dirty_seq to force its recomputation.
 */
void yaffs2_clear_oldest_dirty_seq(yaffs_dev_t *dev, yaffs_block_info_t *bi)
{

	if(!dev->param.is_yaffs2)
		return;

	if(!bi || bi->seq_number == dev->oldest_dirty_seq){
		dev->oldest_dirty_seq = 0;
		dev->oldest_dirty_block = 0;
	}
}

/*
 * yaffs2_update_oldest_dirty_seq()
 * Update the oldest dirty sequence number whenever we dirty a block.
 * Only do this if the oldest_dirty_seq is actually being tracked.
 */
void yaffs2_update_oldest_dirty_seq(yaffs_dev_t *dev, unsigned block_no, yaffs_block_info_t *bi)
{
	if(!dev->param.is_yaffs2)
		return;

	if(dev->oldest_dirty_seq){
		if(dev->oldest_dirty_seq > bi->seq_number){
			dev->oldest_dirty_seq = bi->seq_number;
			dev->oldest_dirty_block = block_no;
		}
	}
}

int yaffs_block_ok_for_gc(yaffs_dev_t *dev,
					yaffs_block_info_t *bi)
{

	if (!dev->param.is_yaffs2)
		return 1;	/* disqualification only applies to yaffs2. */

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

	yaffs2_find_oldest_dirty_seq(dev);

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

/*
 * yaffs2_find_refresh_block()
 * periodically finds the oldest full block by sequence number for refreshing.
 * Only for yaffs2.
 */
__u32 yaffs2_find_refresh_block(yaffs_dev_t *dev)
{
	__u32 b ;

	__u32 oldest = 0;
	__u32 oldestSequence = 0;

	yaffs_block_info_t *bi;

	if(!dev->param.is_yaffs2)
		return oldest;

	/*
	 * If refresh period < 10 then refreshing is disabled.
	 */
	if(dev->param.refresh_period < 10)
	        return oldest;

        /*
         * Fix broken values.
         */
        if(dev->refresh_skip > dev->param.refresh_period)
                dev->refresh_skip = dev->param.refresh_period;

	if(dev->refresh_skip > 0)
	        return oldest;

	/*
	 * Refresh skip is now zero.
	 * We'll do a refresh this time around....
	 * Update the refresh skip and find the oldest block.
	 */
	dev->refresh_skip = dev->param.refresh_period;
	dev->refresh_count++;
	bi = dev->block_info;
	for (b = dev->internal_start_block; b <=dev->internal_end_block; b++){

		if (bi->block_state == YAFFS_BLOCK_STATE_FULL){

			if(oldest < 1 ||
                                bi->seq_number < oldestSequence){
                                oldest = b;
                                oldestSequence = bi->seq_number;
                        }
		}
		bi++;
	}

	if (oldest > 0) {
		T(YAFFS_TRACE_GC,
		  (TSTR("GC refresh count %d selected block %d with seq_number %d" TENDSTR),
		   dev->refresh_count, oldest, oldestSequence));
	}

	return oldest;
}

int yaffs2_checkpt_required(yaffs_dev_t *dev)
{
	int nblocks;
	
	if(!dev->param.is_yaffs2)
		return 0;
	
	nblocks = dev->internal_end_block - dev->internal_start_block + 1 ;

	return 	!dev->param.skip_checkpt_wr &&
		!dev->read_only &&
		(nblocks >= YAFFS_CHECKPOINT_MIN_BLOCKS);
}

int yaffs_calc_checkpt_blocks_required(yaffs_dev_t *dev)
{
	int retval;

	if(!dev->param.is_yaffs2)
		return 0;

	if (!dev->checkpoint_blocks_required &&
		yaffs2_checkpt_required(dev)){
		/* Not a valid value so recalculate */
		int n_bytes = 0;
		int nBlocks;
		int devBlocks = (dev->param.end_block - dev->param.start_block + 1);

		n_bytes += sizeof(yaffs_checkpt_validty_t);
		n_bytes += sizeof(yaffs_checkpt_dev_t);
		n_bytes += devBlocks * sizeof(yaffs_block_info_t);
		n_bytes += devBlocks * dev->chunk_bit_stride;
		n_bytes += (sizeof(yaffs_checkpt_obj_t) + sizeof(__u32)) * (dev->n_obj);
		n_bytes += (dev->tnode_size + sizeof(__u32)) * (dev->n_tnodes);
		n_bytes += sizeof(yaffs_checkpt_validty_t);
		n_bytes += sizeof(__u32); /* checksum*/

		/* Round up and add 2 blocks to allow for some bad blocks, so add 3 */

		nBlocks = (n_bytes/(dev->data_bytes_per_chunk * dev->param.chunks_per_block)) + 3;

		dev->checkpoint_blocks_required = nBlocks;
	}

	retval = dev->checkpoint_blocks_required - dev->blocks_in_checkpt;
	if(retval < 0)
		retval = 0;
	return retval;
}

/*--------------------- Checkpointing --------------------*/


static int yaffs2_wr_checkpt_validity_marker(yaffs_dev_t *dev, int head)
{
	yaffs_checkpt_validty_t cp;

	memset(&cp, 0, sizeof(cp));

	cp.struct_type = sizeof(cp);
	cp.magic = YAFFS_MAGIC;
	cp.version = YAFFS_CHECKPOINT_VERSION;
	cp.head = (head) ? 1 : 0;

	return (yaffs2_checkpt_wr(dev, &cp, sizeof(cp)) == sizeof(cp)) ?
		1 : 0;
}

static int yaffs2_rd_checkpt_validty_marker(yaffs_dev_t *dev, int head)
{
	yaffs_checkpt_validty_t cp;
	int ok;

	ok = (yaffs2_checkpt_rd(dev, &cp, sizeof(cp)) == sizeof(cp));

	if (ok)
		ok = (cp.struct_type == sizeof(cp)) &&
		     (cp.magic == YAFFS_MAGIC) &&
		     (cp.version == YAFFS_CHECKPOINT_VERSION) &&
		     (cp.head == ((head) ? 1 : 0));
	return ok ? 1 : 0;
}

static void yaffs2_dev_to_checkpt_dev(yaffs_checkpt_dev_t *cp,
					   yaffs_dev_t *dev)
{
	cp->n_erased_blocks = dev->n_erased_blocks;
	cp->alloc_block = dev->alloc_block;
	cp->alloc_page = dev->alloc_page;
	cp->n_free_chunks = dev->n_free_chunks;

	cp->n_deleted_files = dev->n_deleted_files;
	cp->n_unlinked_files = dev->n_unlinked_files;
	cp->n_bg_deletions = dev->n_bg_deletions;
	cp->seq_number = dev->seq_number;

}

static void yaffs_checkpt_dev_to_dev(yaffs_dev_t *dev,
					   yaffs_checkpt_dev_t *cp)
{
	dev->n_erased_blocks = cp->n_erased_blocks;
	dev->alloc_block = cp->alloc_block;
	dev->alloc_page = cp->alloc_page;
	dev->n_free_chunks = cp->n_free_chunks;

	dev->n_deleted_files = cp->n_deleted_files;
	dev->n_unlinked_files = cp->n_unlinked_files;
	dev->n_bg_deletions = cp->n_bg_deletions;
	dev->seq_number = cp->seq_number;
}


static int yaffs2_wr_checkpt_dev(yaffs_dev_t *dev)
{
	yaffs_checkpt_dev_t cp;
	__u32 n_bytes;
	__u32 nBlocks = (dev->internal_end_block - dev->internal_start_block + 1);

	int ok;

	/* Write device runtime values*/
	yaffs2_dev_to_checkpt_dev(&cp, dev);
	cp.struct_type = sizeof(cp);

	ok = (yaffs2_checkpt_wr(dev, &cp, sizeof(cp)) == sizeof(cp));

	/* Write block info */
	if (ok) {
		n_bytes = nBlocks * sizeof(yaffs_block_info_t);
		ok = (yaffs2_checkpt_wr(dev, dev->block_info, n_bytes) == n_bytes);
	}

	/* Write chunk bits */
	if (ok) {
		n_bytes = nBlocks * dev->chunk_bit_stride;
		ok = (yaffs2_checkpt_wr(dev, dev->chunk_bits, n_bytes) == n_bytes);
	}
	return	 ok ? 1 : 0;

}

static int yaffs2_rd_checkpt_dev(yaffs_dev_t *dev)
{
	yaffs_checkpt_dev_t cp;
	__u32 n_bytes;
	__u32 nBlocks = (dev->internal_end_block - dev->internal_start_block + 1);

	int ok;

	ok = (yaffs2_checkpt_rd(dev, &cp, sizeof(cp)) == sizeof(cp));
	if (!ok)
		return 0;

	if (cp.struct_type != sizeof(cp))
		return 0;


	yaffs_checkpt_dev_to_dev(dev, &cp);

	n_bytes = nBlocks * sizeof(yaffs_block_info_t);

	ok = (yaffs2_checkpt_rd(dev, dev->block_info, n_bytes) == n_bytes);

	if (!ok)
		return 0;
	n_bytes = nBlocks * dev->chunk_bit_stride;

	ok = (yaffs2_checkpt_rd(dev, dev->chunk_bits, n_bytes) == n_bytes);

	return ok ? 1 : 0;
}

static void yaffs2_obj_checkpt_obj(yaffs_checkpt_obj_t *cp,
					   yaffs_obj_t *obj)
{

	cp->obj_id = obj->obj_id;
	cp->parent_id = (obj->parent) ? obj->parent->obj_id : 0;
	cp->hdr_chunk = obj->hdr_chunk;
	cp->variant_type = obj->variant_type;
	cp->deleted = obj->deleted;
	cp->soft_del = obj->soft_del;
	cp->unlinked = obj->unlinked;
	cp->fake = obj->fake;
	cp->rename_allowed = obj->rename_allowed;
	cp->unlink_allowed = obj->unlink_allowed;
	cp->serial = obj->serial;
	cp->n_data_chunks = obj->n_data_chunks;

	if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
		cp->size_or_equiv_obj = obj->variant.file_variant.file_size;
	else if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK)
		cp->size_or_equiv_obj = obj->variant.hardlink_variant.equiv_id;
}

static int taffs2_checkpt_obj_to_obj(yaffs_obj_t *obj, yaffs_checkpt_obj_t *cp)
{

	yaffs_obj_t *parent;

	if (obj->variant_type != cp->variant_type) {
		T(YAFFS_TRACE_ERROR, (TSTR("Checkpoint read object %d type %d "
			TCONT("chunk %d does not match existing object type %d")
			TENDSTR), cp->obj_id, cp->variant_type, cp->hdr_chunk,
			obj->variant_type));
		return 0;
	}

	obj->obj_id = cp->obj_id;

	if (cp->parent_id)
		parent = yaffs_find_or_create_by_number(
					obj->my_dev,
					cp->parent_id,
					YAFFS_OBJECT_TYPE_DIRECTORY);
	else
		parent = NULL;

	if (parent) {
		if (parent->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
			T(YAFFS_TRACE_ALWAYS, (TSTR("Checkpoint read object %d parent %d type %d"
				TCONT(" chunk %d Parent type, %d, not directory")
				TENDSTR),
				cp->obj_id, cp->parent_id, cp->variant_type,
				cp->hdr_chunk, parent->variant_type));
			return 0;
		}
		yaffs_add_obj_to_dir(parent, obj);
	}

	obj->hdr_chunk = cp->hdr_chunk;
	obj->variant_type = cp->variant_type;
	obj->deleted = cp->deleted;
	obj->soft_del = cp->soft_del;
	obj->unlinked = cp->unlinked;
	obj->fake = cp->fake;
	obj->rename_allowed = cp->rename_allowed;
	obj->unlink_allowed = cp->unlink_allowed;
	obj->serial = cp->serial;
	obj->n_data_chunks = cp->n_data_chunks;

	if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
		obj->variant.file_variant.file_size = cp->size_or_equiv_obj;
	else if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK)
		obj->variant.hardlink_variant.equiv_id = cp->size_or_equiv_obj;

	if (obj->hdr_chunk > 0)
		obj->lazy_loaded = 1;
	return 1;
}


static int yaffs2_checkpt_tnode_worker(yaffs_obj_t *in, yaffs_tnode_t *tn,
					__u32 level, int chunk_offset)
{
	int i;
	yaffs_dev_t *dev = in->my_dev;
	int ok = 1;

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

			for (i = 0; i < YAFFS_NTNODES_INTERNAL && ok; i++) {
				if (tn->internal[i]) {
					ok = yaffs2_checkpt_tnode_worker(in,
							tn->internal[i],
							level - 1,
							(chunk_offset<<YAFFS_TNODES_INTERNAL_BITS) + i);
				}
			}
		} else if (level == 0) {
			__u32 baseOffset = chunk_offset <<  YAFFS_TNODES_LEVEL0_BITS;
			ok = (yaffs2_checkpt_wr(dev, &baseOffset, sizeof(baseOffset)) == sizeof(baseOffset));
			if (ok)
				ok = (yaffs2_checkpt_wr(dev, tn, dev->tnode_size) == dev->tnode_size);
		}
	}

	return ok;

}

static int yaffs2_wr_checkpt_tnodes(yaffs_obj_t *obj)
{
	__u32 endMarker = ~0;
	int ok = 1;

	if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE) {
		ok = yaffs2_checkpt_tnode_worker(obj,
					    obj->variant.file_variant.top,
					    obj->variant.file_variant.top_level,
					    0);
		if (ok)
			ok = (yaffs2_checkpt_wr(obj->my_dev, &endMarker, sizeof(endMarker)) ==
				sizeof(endMarker));
	}

	return ok ? 1 : 0;
}

static int yaffs2_rd_checkpt_tnodes(yaffs_obj_t *obj)
{
	__u32 baseChunk;
	int ok = 1;
	yaffs_dev_t *dev = obj->my_dev;
	yaffs_file_s *fileStructPtr = &obj->variant.file_variant;
	yaffs_tnode_t *tn;
	int nread = 0;

	ok = (yaffs2_checkpt_rd(dev, &baseChunk, sizeof(baseChunk)) == sizeof(baseChunk));

	while (ok && (~baseChunk)) {
		nread++;
		/* Read level 0 tnode */


		tn = yaffs_get_tnode(dev);
		if (tn){
			ok = (yaffs2_checkpt_rd(dev, tn, dev->tnode_size) == dev->tnode_size);
		} else
			ok = 0;

		if (tn && ok)
			ok = yaffs_add_find_tnode_0(dev,
							fileStructPtr,
							baseChunk,
							tn) ? 1 : 0;

		if (ok)
			ok = (yaffs2_checkpt_rd(dev, &baseChunk, sizeof(baseChunk)) == sizeof(baseChunk));

	}

	T(YAFFS_TRACE_CHECKPOINT, (
		TSTR("Checkpoint read tnodes %d records, last %d. ok %d" TENDSTR),
		nread, baseChunk, ok));

	return ok ? 1 : 0;
}


static int yaffs2_wr_checkpt_objs(yaffs_dev_t *dev)
{
	yaffs_obj_t *obj;
	yaffs_checkpt_obj_t cp;
	int i;
	int ok = 1;
	struct ylist_head *lh;


	/* Iterate through the objects in each hash entry,
	 * dumping them to the checkpointing stream.
	 */

	for (i = 0; ok &&  i <  YAFFS_NOBJECT_BUCKETS; i++) {
		ylist_for_each(lh, &dev->obj_bucket[i].list) {
			if (lh) {
				obj = ylist_entry(lh, yaffs_obj_t, hash_link);
				if (!obj->defered_free) {
					yaffs2_obj_checkpt_obj(&cp, obj);
					cp.struct_type = sizeof(cp);

					T(YAFFS_TRACE_CHECKPOINT, (
						TSTR("Checkpoint write object %d parent %d type %d chunk %d obj addr %p" TENDSTR),
						cp.obj_id, cp.parent_id, cp.variant_type, cp.hdr_chunk, obj));

					ok = (yaffs2_checkpt_wr(dev, &cp, sizeof(cp)) == sizeof(cp));

					if (ok && obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
						ok = yaffs2_wr_checkpt_tnodes(obj);
				}
			}
		}
	}

	/* Dump end of list */
	memset(&cp, 0xFF, sizeof(yaffs_checkpt_obj_t));
	cp.struct_type = sizeof(cp);

	if (ok)
		ok = (yaffs2_checkpt_wr(dev, &cp, sizeof(cp)) == sizeof(cp));

	return ok ? 1 : 0;
}

static int yaffs2_rd_checkpt_objs(yaffs_dev_t *dev)
{
	yaffs_obj_t *obj;
	yaffs_checkpt_obj_t cp;
	int ok = 1;
	int done = 0;
	yaffs_obj_t *hard_list = NULL;

	while (ok && !done) {
		ok = (yaffs2_checkpt_rd(dev, &cp, sizeof(cp)) == sizeof(cp));
		if (cp.struct_type != sizeof(cp)) {
			T(YAFFS_TRACE_CHECKPOINT, (TSTR("struct size %d instead of %d ok %d"TENDSTR),
				cp.struct_type, (int)sizeof(cp), ok));
			ok = 0;
		}

		T(YAFFS_TRACE_CHECKPOINT, (TSTR("Checkpoint read object %d parent %d type %d chunk %d " TENDSTR),
			cp.obj_id, cp.parent_id, cp.variant_type, cp.hdr_chunk));

		if (ok && cp.obj_id == ~0)
			done = 1;
		else if (ok) {
			obj = yaffs_find_or_create_by_number(dev, cp.obj_id, cp.variant_type);
			if (obj) {
				ok = taffs2_checkpt_obj_to_obj(obj, &cp);
				if (!ok)
					break;
				if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE) {
					ok = yaffs2_rd_checkpt_tnodes(obj);
				} else if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
					obj->hard_links.next =
						(struct ylist_head *) hard_list;
					hard_list = obj;
				}
			} else
				ok = 0;
		}
	}

	if (ok)
		yaffs_link_fixup(dev, hard_list);

	return ok ? 1 : 0;
}

static int yaffs2_wr_checkpt_sum(yaffs_dev_t *dev)
{
	__u32 checkpt_sum;
	int ok;

	yaffs2_get_checkpt_sum(dev, &checkpt_sum);

	ok = (yaffs2_checkpt_wr(dev, &checkpt_sum, sizeof(checkpt_sum)) == sizeof(checkpt_sum));

	if (!ok)
		return 0;

	return 1;
}

static int yaffs2_rd_checkpt_sum(yaffs_dev_t *dev)
{
	__u32 checkpt_sum0;
	__u32 checkpt_sum1;
	int ok;

	yaffs2_get_checkpt_sum(dev, &checkpt_sum0);

	ok = (yaffs2_checkpt_rd(dev, &checkpt_sum1, sizeof(checkpt_sum1)) == sizeof(checkpt_sum1));

	if (!ok)
		return 0;

	if (checkpt_sum0 != checkpt_sum1)
		return 0;

	return 1;
}


static int yaffs2_wr_checkpt_data(yaffs_dev_t *dev)
{
	int ok = 1;

	if (!yaffs2_checkpt_required(dev)) {
		T(YAFFS_TRACE_CHECKPOINT, (TSTR("skipping checkpoint write" TENDSTR)));
		ok = 0;
	}

	if (ok)
		ok = yaffs2_checkpt_open(dev, 1);

	if (ok) {
		T(YAFFS_TRACE_CHECKPOINT, (TSTR("write checkpoint validity" TENDSTR)));
		ok = yaffs2_wr_checkpt_validity_marker(dev, 1);
	}
	if (ok) {
		T(YAFFS_TRACE_CHECKPOINT, (TSTR("write checkpoint device" TENDSTR)));
		ok = yaffs2_wr_checkpt_dev(dev);
	}
	if (ok) {
		T(YAFFS_TRACE_CHECKPOINT, (TSTR("write checkpoint objects" TENDSTR)));
		ok = yaffs2_wr_checkpt_objs(dev);
	}
	if (ok) {
		T(YAFFS_TRACE_CHECKPOINT, (TSTR("write checkpoint validity" TENDSTR)));
		ok = yaffs2_wr_checkpt_validity_marker(dev, 0);
	}

	if (ok)
		ok = yaffs2_wr_checkpt_sum(dev);

	if (!yaffs_checkpt_close(dev))
		ok = 0;

	if (ok)
		dev->is_checkpointed = 1;
	else
		dev->is_checkpointed = 0;

	return dev->is_checkpointed;
}

static int yaffs2_rd_checkpt_data(yaffs_dev_t *dev)
{
	int ok = 1;
	
	if(!dev->param.is_yaffs2)
		ok = 0;

	if (ok && dev->param.skip_checkpt_rd) {
		T(YAFFS_TRACE_CHECKPOINT, (TSTR("skipping checkpoint read" TENDSTR)));
		ok = 0;
	}

	if (ok)
		ok = yaffs2_checkpt_open(dev, 0); /* open for read */

	if (ok) {
		T(YAFFS_TRACE_CHECKPOINT, (TSTR("read checkpoint validity" TENDSTR)));
		ok = yaffs2_rd_checkpt_validty_marker(dev, 1);
	}
	if (ok) {
		T(YAFFS_TRACE_CHECKPOINT, (TSTR("read checkpoint device" TENDSTR)));
		ok = yaffs2_rd_checkpt_dev(dev);
	}
	if (ok) {
		T(YAFFS_TRACE_CHECKPOINT, (TSTR("read checkpoint objects" TENDSTR)));
		ok = yaffs2_rd_checkpt_objs(dev);
	}
	if (ok) {
		T(YAFFS_TRACE_CHECKPOINT, (TSTR("read checkpoint validity" TENDSTR)));
		ok = yaffs2_rd_checkpt_validty_marker(dev, 0);
	}

	if (ok) {
		ok = yaffs2_rd_checkpt_sum(dev);
		T(YAFFS_TRACE_CHECKPOINT, (TSTR("read checkpoint checksum %d" TENDSTR), ok));
	}

	if (!yaffs_checkpt_close(dev))
		ok = 0;

	if (ok)
		dev->is_checkpointed = 1;
	else
		dev->is_checkpointed = 0;

	return ok ? 1 : 0;

}

void yaffs2_checkpt_invalidate(yaffs_dev_t *dev)
{
	if (dev->is_checkpointed ||
			dev->blocks_in_checkpt > 0) {
		dev->is_checkpointed = 0;
		yaffs2_checkpt_invalidate_stream(dev);
	}
	if (dev->param.sb_dirty_fn)
		dev->param.sb_dirty_fn(dev);
}


int yaffs_checkpoint_save(yaffs_dev_t *dev)
{

	T(YAFFS_TRACE_CHECKPOINT, (TSTR("save entry: is_checkpointed %d"TENDSTR), dev->is_checkpointed));

	yaffs_verify_objects(dev);
	yaffs_verify_blocks(dev);
	yaffs_verify_free_chunks(dev);

	if (!dev->is_checkpointed) {
		yaffs2_checkpt_invalidate(dev);
		yaffs2_wr_checkpt_data(dev);
	}

	T(YAFFS_TRACE_ALWAYS, (TSTR("save exit: is_checkpointed %d"TENDSTR), dev->is_checkpointed));

	return dev->is_checkpointed;
}

int yaffs2_checkpt_restore(yaffs_dev_t *dev)
{
	int retval;
	T(YAFFS_TRACE_CHECKPOINT, (TSTR("restore entry: is_checkpointed %d"TENDSTR), dev->is_checkpointed));

	retval = yaffs2_rd_checkpt_data(dev);

	if (dev->is_checkpointed) {
		yaffs_verify_objects(dev);
		yaffs_verify_blocks(dev);
		yaffs_verify_free_chunks(dev);
	}

	T(YAFFS_TRACE_CHECKPOINT, (TSTR("restore exit: is_checkpointed %d"TENDSTR), dev->is_checkpointed));

	return retval;
}

int yaffs2_handle_hole(yaffs_obj_t *obj, loff_t new_size)
{
	/* if newsSize > oldFileSize.
	 * We're going to be writing a hole.
	 * If the hole is small then write zeros otherwise write a start of hole marker.
	 */
		

	loff_t oldFileSize;
	int increase;
	int smallHole   ;
	int result = YAFFS_OK;
	yaffs_dev_t *dev = NULL;

	__u8 *localBuffer = NULL;
	
	int smallIncreaseOk = 0;
	
	if(!obj)
		return YAFFS_FAIL;

	if(obj->variant_type != YAFFS_OBJECT_TYPE_FILE)
		return YAFFS_FAIL;
	
	dev = obj->my_dev;
	
	/* Bail out if not yaffs2 mode */
	if(!dev->param.is_yaffs2)
		return YAFFS_OK;

	oldFileSize = obj->variant.file_variant.file_size;

	if (new_size <= oldFileSize)
		return YAFFS_OK;

	increase = new_size - oldFileSize;

	if(increase < YAFFS_SMALL_HOLE_THRESHOLD * dev->data_bytes_per_chunk &&
		yaffs_check_alloc_available(dev, YAFFS_SMALL_HOLE_THRESHOLD + 1))
		smallHole = 1;
	else
		smallHole = 0;

	if(smallHole)
		localBuffer= yaffs_get_temp_buffer(dev, __LINE__);
	
	if(localBuffer){
		/* fill hole with zero bytes */
		int pos = oldFileSize;
		int thisWrite;
		int written;
		memset(localBuffer,0,dev->data_bytes_per_chunk);
		smallIncreaseOk = 1;

		while(increase > 0 && smallIncreaseOk){
			thisWrite = increase;
			if(thisWrite > dev->data_bytes_per_chunk)
				thisWrite = dev->data_bytes_per_chunk;
			written = yaffs_do_file_wr(obj,localBuffer,pos,thisWrite,0);
			if(written == thisWrite){
				pos += thisWrite;
				increase -= thisWrite;
			} else
				smallIncreaseOk = 0;
		}

		yaffs_release_temp_buffer(dev,localBuffer,__LINE__);

		/* If we were out of space then reverse any chunks we've added */		
		if(!smallIncreaseOk)
			yaffs_resize_file_down(obj, oldFileSize);
	}
	
	if (!smallIncreaseOk &&
		obj->parent &&
		obj->parent->obj_id != YAFFS_OBJECTID_UNLINKED &&
		obj->parent->obj_id != YAFFS_OBJECTID_DELETED){
		/* Write a hole start header with the old file size */
		yaffs_update_oh(obj, NULL, 0, 1, 0, NULL);
	}

	return result;

}


typedef struct {
	int seq;
	int block;
} yaffs_BlockIndex;


static int yaffs2_ybicmp(const void *a, const void *b)
{
	register int aseq = ((yaffs_BlockIndex *)a)->seq;
	register int bseq = ((yaffs_BlockIndex *)b)->seq;
	register int ablock = ((yaffs_BlockIndex *)a)->block;
	register int bblock = ((yaffs_BlockIndex *)b)->block;
	if (aseq == bseq)
		return ablock - bblock;
	else
		return aseq - bseq;
}

int yaffs2_scan_backwards(yaffs_dev_t *dev)
{
	yaffs_ext_tags tags;
	int blk;
	int blockIterator;
	int startIterator;
	int endIterator;
	int nBlocksToScan = 0;

	int chunk;
	int result;
	int c;
	int deleted;
	yaffs_block_state_t state;
	yaffs_obj_t *hard_list = NULL;
	yaffs_block_info_t *bi;
	__u32 seq_number;
	yaffs_obj_header *oh;
	yaffs_obj_t *in;
	yaffs_obj_t *parent;
	int nBlocks = dev->internal_end_block - dev->internal_start_block + 1;
	int itsUnlinked;
	__u8 *chunkData;

	int file_size;
	int is_shrink;
	int foundChunksInBlock;
	int equiv_id;
	int alloc_failed = 0;


	yaffs_BlockIndex *blockIndex = NULL;
	int altBlockIndex = 0;

	T(YAFFS_TRACE_SCAN,
	  (TSTR
	   ("yaffs2_scan_backwards starts  intstartblk %d intendblk %d..."
	    TENDSTR), dev->internal_start_block, dev->internal_end_block));


	dev->seq_number = YAFFS_LOWEST_SEQUENCE_NUMBER;

	blockIndex = YMALLOC(nBlocks * sizeof(yaffs_BlockIndex));

	if (!blockIndex) {
		blockIndex = YMALLOC_ALT(nBlocks * sizeof(yaffs_BlockIndex));
		altBlockIndex = 1;
	}

	if (!blockIndex) {
		T(YAFFS_TRACE_SCAN,
		  (TSTR("yaffs2_scan_backwards() could not allocate block index!" TENDSTR)));
		return YAFFS_FAIL;
	}

	dev->blocks_in_checkpt = 0;

	chunkData = yaffs_get_temp_buffer(dev, __LINE__);

	/* Scan all the blocks to determine their state */
	bi = dev->block_info;
	for (blk = dev->internal_start_block; blk <= dev->internal_end_block; blk++) {
		yaffs_clear_chunk_bits(dev, blk);
		bi->pages_in_use = 0;
		bi->soft_del_pages = 0;

		yaffs_query_init_block_state(dev, blk, &state, &seq_number);

		bi->block_state = state;
		bi->seq_number = seq_number;

		if (bi->seq_number == YAFFS_SEQUENCE_CHECKPOINT_DATA)
			bi->block_state = state = YAFFS_BLOCK_STATE_CHECKPOINT;
		if (bi->seq_number == YAFFS_SEQUENCE_BAD_BLOCK)
			bi->block_state = state = YAFFS_BLOCK_STATE_DEAD;

		T(YAFFS_TRACE_SCAN_DEBUG,
		  (TSTR("Block scanning block %d state %d seq %d" TENDSTR), blk,
		   state, seq_number));


		if (state == YAFFS_BLOCK_STATE_CHECKPOINT) {
			dev->blocks_in_checkpt++;

		} else if (state == YAFFS_BLOCK_STATE_DEAD) {
			T(YAFFS_TRACE_BAD_BLOCKS,
			  (TSTR("block %d is bad" TENDSTR), blk));
		} else if (state == YAFFS_BLOCK_STATE_EMPTY) {
			T(YAFFS_TRACE_SCAN_DEBUG,
			  (TSTR("Block empty " TENDSTR)));
			dev->n_erased_blocks++;
			dev->n_free_chunks += dev->param.chunks_per_block;
		} else if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING) {

			/* Determine the highest sequence number */
			if (seq_number >= YAFFS_LOWEST_SEQUENCE_NUMBER &&
			    seq_number < YAFFS_HIGHEST_SEQUENCE_NUMBER) {

				blockIndex[nBlocksToScan].seq = seq_number;
				blockIndex[nBlocksToScan].block = blk;

				nBlocksToScan++;

				if (seq_number >= dev->seq_number)
					dev->seq_number = seq_number;
			} else {
				/* TODO: Nasty sequence number! */
				T(YAFFS_TRACE_SCAN,
				  (TSTR
				   ("Block scanning block %d has bad sequence number %d"
				    TENDSTR), blk, seq_number));

			}
		}
		bi++;
	}

	T(YAFFS_TRACE_SCAN,
	(TSTR("%d blocks to be sorted..." TENDSTR), nBlocksToScan));


	YYIELD();

	/* Sort the blocks by sequence number*/
	yaffs_qsort(blockIndex, nBlocksToScan, sizeof(yaffs_BlockIndex), yaffs2_ybicmp);

	YYIELD();

	T(YAFFS_TRACE_SCAN, (TSTR("...done" TENDSTR)));

	/* Now scan the blocks looking at the data. */
	startIterator = 0;
	endIterator = nBlocksToScan - 1;
	T(YAFFS_TRACE_SCAN_DEBUG,
	  (TSTR("%d blocks to be scanned" TENDSTR), nBlocksToScan));

	/* For each block.... backwards */
	for (blockIterator = endIterator; !alloc_failed && blockIterator >= startIterator;
			blockIterator--) {
		/* Cooperative multitasking! This loop can run for so
		   long that watchdog timers expire. */
		YYIELD();

		/* get the block to scan in the correct order */
		blk = blockIndex[blockIterator].block;

		bi = yaffs_get_block_info(dev, blk);


		state = bi->block_state;

		deleted = 0;

		/* For each chunk in each block that needs scanning.... */
		foundChunksInBlock = 0;
		for (c = dev->param.chunks_per_block - 1;
		     !alloc_failed && c >= 0 &&
		     (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING ||
		      state == YAFFS_BLOCK_STATE_ALLOCATING); c--) {
			/* Scan backwards...
			 * Read the tags and decide what to do
			 */

			chunk = blk * dev->param.chunks_per_block + c;

			result = yaffs_rd_chunk_tags_nand(dev, chunk, NULL,
							&tags);

			/* Let's have a good look at this chunk... */

			if (!tags.chunk_used) {
				/* An unassigned chunk in the block.
				 * If there are used chunks after this one, then
				 * it is a chunk that was skipped due to failing the erased
				 * check. Just skip it so that it can be deleted.
				 * But, more typically, We get here when this is an unallocated
				 * chunk and his means that either the block is empty or
				 * this is the one being allocated from
				 */

				if (foundChunksInBlock) {
					/* This is a chunk that was skipped due to failing the erased check */
				} else if (c == 0) {
					/* We're looking at the first chunk in the block so the block is unused */
					state = YAFFS_BLOCK_STATE_EMPTY;
					dev->n_erased_blocks++;
				} else {
					if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING ||
					    state == YAFFS_BLOCK_STATE_ALLOCATING) {
						if (dev->seq_number == bi->seq_number) {
							/* this is the block being allocated from */

							T(YAFFS_TRACE_SCAN,
							  (TSTR
							   (" Allocating from %d %d"
							    TENDSTR), blk, c));

							state = YAFFS_BLOCK_STATE_ALLOCATING;
							dev->alloc_block = blk;
							dev->alloc_page = c;
							dev->alloc_block_finder = blk;
						} else {
							/* This is a partially written block that is not
							 * the current allocation block.
							 */

							 T(YAFFS_TRACE_SCAN,
							 (TSTR("Partially written block %d detected" TENDSTR),
							 blk));
						}
					}
				}

				dev->n_free_chunks++;

			} else if (tags.ecc_result == YAFFS_ECC_RESULT_UNFIXED) {
				T(YAFFS_TRACE_SCAN,
				  (TSTR(" Unfixed ECC in chunk(%d:%d), chunk ignored"TENDSTR),
				  blk, c));

				  dev->n_free_chunks++;

			} else if (tags.obj_id > YAFFS_MAX_OBJECT_ID ||
				tags.chunk_id > YAFFS_MAX_CHUNK_ID ||
				(tags.chunk_id > 0 && tags.n_bytes > dev->data_bytes_per_chunk) ||
				tags.seq_number != bi->seq_number ) {
				T(YAFFS_TRACE_SCAN,
				  (TSTR("Chunk (%d:%d) with bad tags:obj = %d, chunk_id = %d, n_bytes = %d, ignored"TENDSTR),
				  blk, c,tags.obj_id, tags.chunk_id, tags.n_bytes));

				  dev->n_free_chunks++;

			} else if (tags.chunk_id > 0) {
				/* chunk_id > 0 so it is a data chunk... */
				unsigned int endpos;
				__u32 chunkBase =
				    (tags.chunk_id - 1) * dev->data_bytes_per_chunk;

				foundChunksInBlock = 1;


				yaffs_set_chunk_bit(dev, blk, c);
				bi->pages_in_use++;

				in = yaffs_find_or_create_by_number(dev,
								      tags.
								      obj_id,
								      YAFFS_OBJECT_TYPE_FILE);
				if (!in) {
					/* Out of memory */
					alloc_failed = 1;
				}

				if (in &&
				    in->variant_type == YAFFS_OBJECT_TYPE_FILE
				    && chunkBase < in->variant.file_variant.shrink_size) {
					/* This has not been invalidated by a resize */
					if (!yaffs_put_chunk_in_file(in, tags.chunk_id, chunk, -1)) {
						alloc_failed = 1;
					}

					/* File size is calculated by looking at the data chunks if we have not
					 * seen an object header yet. Stop this practice once we find an object header.
					 */
					endpos = chunkBase + tags.n_bytes;

					if (!in->valid &&	/* have not got an object header yet */
					    in->variant.file_variant.scanned_size < endpos) {
						in->variant.file_variant.scanned_size = endpos;
						in->variant.file_variant.file_size = endpos;
					}

				} else if (in) {
					/* This chunk has been invalidated by a resize, or a past file deletion
					 * so delete the chunk*/
					yaffs_chunk_del(dev, chunk, 1, __LINE__);

				}
			} else {
				/* chunk_id == 0, so it is an ObjectHeader.
				 * Thus, we read in the object header and make the object
				 */
				foundChunksInBlock = 1;

				yaffs_set_chunk_bit(dev, blk, c);
				bi->pages_in_use++;

				oh = NULL;
				in = NULL;

				if (tags.extra_available) {
					in = yaffs_find_or_create_by_number(dev,
						tags.obj_id,
						tags.extra_obj_type);
					if (!in)
						alloc_failed = 1;
				}

				if (!in ||
				    (!in->valid && dev->param.disable_lazy_load) ||
				    tags.extra_shadows ||
				    (!in->valid &&
				    (tags.obj_id == YAFFS_OBJECTID_ROOT ||
				     tags.obj_id == YAFFS_OBJECTID_LOSTNFOUND))) {

					/* If we don't have  valid info then we need to read the chunk
					 * TODO In future we can probably defer reading the chunk and
					 * living with invalid data until needed.
					 */

					result = yaffs_rd_chunk_tags_nand(dev,
									chunk,
									chunkData,
									NULL);

					oh = (yaffs_obj_header *) chunkData;

					if (dev->param.inband_tags) {
						/* Fix up the header if they got corrupted by inband tags */
						oh->shadows_obj = oh->inband_shadowed_obj_id;
						oh->is_shrink = oh->inband_is_shrink;
					}

					if (!in) {
						in = yaffs_find_or_create_by_number(dev, tags.obj_id, oh->type);
						if (!in)
							alloc_failed = 1;
					}

				}

				if (!in) {
					/* TODO Hoosterman we have a problem! */
					T(YAFFS_TRACE_ERROR,
					  (TSTR
					   ("yaffs tragedy: Could not make object for object  %d at chunk %d during scan"
					    TENDSTR), tags.obj_id, chunk));
					continue;
				}

				if (in->valid) {
					/* We have already filled this one.
					 * We have a duplicate that will be discarded, but
					 * we first have to suck out resize info if it is a file.
					 */

					if ((in->variant_type == YAFFS_OBJECT_TYPE_FILE) &&
					     ((oh &&
					       oh->type == YAFFS_OBJECT_TYPE_FILE) ||
					      (tags.extra_available  &&
					       tags.extra_obj_type == YAFFS_OBJECT_TYPE_FILE))) {
						__u32 thisSize =
						    (oh) ? oh->file_size : tags.
						    extra_length;
						__u32 parent_obj_id =
						    (oh) ? oh->
						    parent_obj_id : tags.
						    extra_parent_id;


						is_shrink =
						    (oh) ? oh->is_shrink : tags.
						    extra_is_shrink;

						/* If it is deleted (unlinked at start also means deleted)
						 * we treat the file size as being zeroed at this point.
						 */
						if (parent_obj_id ==
						    YAFFS_OBJECTID_DELETED
						    || parent_obj_id ==
						    YAFFS_OBJECTID_UNLINKED) {
							thisSize = 0;
							is_shrink = 1;
						}

						if (is_shrink && in->variant.file_variant.shrink_size > thisSize)
							in->variant.file_variant.shrink_size = thisSize;

						if (is_shrink)
							bi->has_shrink_hdr = 1;

					}
					/* Use existing - destroy this one. */
					yaffs_chunk_del(dev, chunk, 1, __LINE__);

				}

				if (!in->valid && in->variant_type !=
				    (oh ? oh->type : tags.extra_obj_type))
					T(YAFFS_TRACE_ERROR, (
						TSTR("yaffs tragedy: Bad object type, "
					    TCONT("%d != %d, for object %d at chunk ")
					    TCONT("%d during scan")
						TENDSTR), oh ?
					    oh->type : tags.extra_obj_type,
					    in->variant_type, tags.obj_id,
					    chunk));

				if (!in->valid &&
				    (tags.obj_id == YAFFS_OBJECTID_ROOT ||
				     tags.obj_id ==
				     YAFFS_OBJECTID_LOSTNFOUND)) {
					/* We only load some info, don't fiddle with directory structure */
					in->valid = 1;

					if (oh) {

						in->yst_mode = oh->yst_mode;
#ifdef CONFIG_YAFFS_WINCE
						in->win_atime[0] = oh->win_atime[0];
						in->win_ctime[0] = oh->win_ctime[0];
						in->win_mtime[0] = oh->win_mtime[0];
						in->win_atime[1] = oh->win_atime[1];
						in->win_ctime[1] = oh->win_ctime[1];
						in->win_mtime[1] = oh->win_mtime[1];
#else
						in->yst_uid = oh->yst_uid;
						in->yst_gid = oh->yst_gid;
						in->yst_atime = oh->yst_atime;
						in->yst_mtime = oh->yst_mtime;
						in->yst_ctime = oh->yst_ctime;
						in->yst_rdev = oh->yst_rdev;

						in->lazy_loaded = 0;

#endif
					} else
						in->lazy_loaded = 1;

					in->hdr_chunk = chunk;

				} else if (!in->valid) {
					/* we need to load this info */

					in->valid = 1;
					in->hdr_chunk = chunk;

					if (oh) {
						in->variant_type = oh->type;

						in->yst_mode = oh->yst_mode;
#ifdef CONFIG_YAFFS_WINCE
						in->win_atime[0] = oh->win_atime[0];
						in->win_ctime[0] = oh->win_ctime[0];
						in->win_mtime[0] = oh->win_mtime[0];
						in->win_atime[1] = oh->win_atime[1];
						in->win_ctime[1] = oh->win_ctime[1];
						in->win_mtime[1] = oh->win_mtime[1];
#else
						in->yst_uid = oh->yst_uid;
						in->yst_gid = oh->yst_gid;
						in->yst_atime = oh->yst_atime;
						in->yst_mtime = oh->yst_mtime;
						in->yst_ctime = oh->yst_ctime;
						in->yst_rdev = oh->yst_rdev;
#endif

						if (oh->shadows_obj > 0)
							yaffs_handle_shadowed_obj(dev,
									   oh->
									   shadows_obj,
									   1);
							

						yaffs_set_obj_name_from_oh(in, oh);
						parent =
						    yaffs_find_or_create_by_number
							(dev, oh->parent_obj_id,
							 YAFFS_OBJECT_TYPE_DIRECTORY);

						 file_size = oh->file_size;
						 is_shrink = oh->is_shrink;
						 equiv_id = oh->equiv_id;

					} else {
						in->variant_type = tags.extra_obj_type;
						parent =
						    yaffs_find_or_create_by_number
							(dev, tags.extra_parent_id,
							 YAFFS_OBJECT_TYPE_DIRECTORY);
						 file_size = tags.extra_length;
						 is_shrink = tags.extra_is_shrink;
						 equiv_id = tags.extra_equiv_id;
						in->lazy_loaded = 1;

					}
					in->dirty = 0;

					if (!parent)
						alloc_failed = 1;

					/* directory stuff...
					 * hook up to parent
					 */

					if (parent && parent->variant_type ==
					    YAFFS_OBJECT_TYPE_UNKNOWN) {
						/* Set up as a directory */
						parent->variant_type =
							YAFFS_OBJECT_TYPE_DIRECTORY;
						YINIT_LIST_HEAD(&parent->variant.
							dir_variant.
							children);
					} else if (!parent || parent->variant_type !=
						   YAFFS_OBJECT_TYPE_DIRECTORY) {
						/* Hoosterman, another problem....
						 * We're trying to use a non-directory as a directory
						 */

						T(YAFFS_TRACE_ERROR,
						  (TSTR
						   ("yaffs tragedy: attempting to use non-directory as a directory in scan. Put in lost+found."
						    TENDSTR)));
						parent = dev->lost_n_found;
					}

					yaffs_add_obj_to_dir(parent, in);

					itsUnlinked = (parent == dev->del_dir) ||
						      (parent == dev->unlinked_dir);

					if (is_shrink) {
						/* Mark the block as having a shrinkHeader */
						bi->has_shrink_hdr = 1;
					}

					/* Note re hardlinks.
					 * Since we might scan a hardlink before its equivalent object is scanned
					 * we put them all in a list.
					 * After scanning is complete, we should have all the objects, so we run
					 * through this list and fix up all the chains.
					 */

					switch (in->variant_type) {
					case YAFFS_OBJECT_TYPE_UNKNOWN:
						/* Todo got a problem */
						break;
					case YAFFS_OBJECT_TYPE_FILE:

						if (in->variant.file_variant.
						    scanned_size < file_size) {
							/* This covers the case where the file size is greater
							 * than where the data is
							 * This will happen if the file is resized to be larger
							 * than its current data extents.
							 */
							in->variant.file_variant.file_size = file_size;
							in->variant.file_variant.scanned_size = file_size;
						}

						if (in->variant.file_variant.shrink_size > file_size)
							in->variant.file_variant.shrink_size = file_size;
				

						break;
					case YAFFS_OBJECT_TYPE_HARDLINK:
						if (!itsUnlinked) {
							in->variant.hardlink_variant.equiv_id =
								equiv_id;
							in->hard_links.next =
								(struct ylist_head *) hard_list;
							hard_list = in;
						}
						break;
					case YAFFS_OBJECT_TYPE_DIRECTORY:
						/* Do nothing */
						break;
					case YAFFS_OBJECT_TYPE_SPECIAL:
						/* Do nothing */
						break;
					case YAFFS_OBJECT_TYPE_SYMLINK:
						if (oh) {
							in->variant.symlink_variant.alias =
								yaffs_clone_str(oh->alias);
							if (!in->variant.symlink_variant.alias)
								alloc_failed = 1;
						}
						break;
					}

				}

			}

		} /* End of scanning for each chunk */

		if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
			/* If we got this far while scanning, then the block is fully allocated. */
			state = YAFFS_BLOCK_STATE_FULL;
		}


		bi->block_state = state;

		/* Now let's see if it was dirty */
		if (bi->pages_in_use == 0 &&
		    !bi->has_shrink_hdr &&
		    bi->block_state == YAFFS_BLOCK_STATE_FULL) {
			yaffs_block_became_dirty(dev, blk);
		}

	}
	
	yaffs_skip_rest_of_block(dev);

	if (altBlockIndex)
		YFREE_ALT(blockIndex);
	else
		YFREE(blockIndex);

	/* Ok, we've done all the scanning.
	 * Fix up the hard link chains.
	 * We should now have scanned all the objects, now it's time to add these
	 * hardlinks.
	 */
	yaffs_link_fixup(dev, hard_list);


	yaffs_release_temp_buffer(dev, chunkData, __LINE__);

	if (alloc_failed)
		return YAFFS_FAIL;

	T(YAFFS_TRACE_SCAN, (TSTR("yaffs2_scan_backwards ends" TENDSTR)));

	return YAFFS_OK;
}