Add qemu 2.4.0

Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>

1 files changed, 5021 insertions, 0 deletions

diff --git a/qemu/roms/u-boot/fs/yaffs2/yaffs_guts.c b/qemu/roms/u-boot/fs/yaffs2/yaffs_guts.c
new file mode 100644
index 000000000..21441fd99
--- /dev/null
+++ b/qemu/roms/u-boot/fs/yaffs2/yaffs_guts.c
@@ -0,0 +1,5021 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2011 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 "yportenv.h"
+#include "yaffs_trace.h"
+
+#include "yaffs_guts.h"
+#include "yaffs_getblockinfo.h"
+#include "yaffs_tagscompat.h"
+#include "yaffs_nand.h"
+#include "yaffs_yaffs1.h"
+#include "yaffs_yaffs2.h"
+#include "yaffs_bitmap.h"
+#include "yaffs_verify.h"
+#include "yaffs_nand.h"
+#include "yaffs_packedtags2.h"
+#include "yaffs_nameval.h"
+#include "yaffs_allocator.h"
+#include "yaffs_attribs.h"
+#include "yaffs_summary.h"
+
+/* Note YAFFS_GC_GOOD_ENOUGH must be <= YAFFS_GC_PASSIVE_THRESHOLD */
+#define YAFFS_GC_GOOD_ENOUGH 2
+#define YAFFS_GC_PASSIVE_THRESHOLD 4
+
+#include "yaffs_ecc.h"
+
+/* Forward declarations */
+
+static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk,
+			     const u8 *buffer, int n_bytes, int use_reserve);
+
+
+
+/* Function to calculate chunk and offset */
+
+void yaffs_addr_to_chunk(struct yaffs_dev *dev, loff_t addr,
+				int *chunk_out, u32 *offset_out)
+{
+	int chunk;
+	u32 offset;
+
+	chunk = (u32) (addr >> dev->chunk_shift);
+
+	if (dev->chunk_div == 1) {
+		/* easy power of 2 case */
+		offset = (u32) (addr & dev->chunk_mask);
+	} else {
+		/* Non power-of-2 case */
+
+		loff_t chunk_base;
+
+		chunk /= dev->chunk_div;
+
+		chunk_base = ((loff_t) chunk) * dev->data_bytes_per_chunk;
+		offset = (u32) (addr - chunk_base);
+	}
+
+	*chunk_out = chunk;
+	*offset_out = offset;
+}
+
+/* Function to return the number of shifts for a power of 2 greater than or
+ * equal to the given number
+ * Note we don't try to cater for all possible numbers and this does not have to
+ * be hellishly efficient.
+ */
+
+static inline u32 calc_shifts_ceiling(u32 x)
+{
+	int extra_bits;
+	int shifts;
+
+	shifts = extra_bits = 0;
+
+	while (x > 1) {
+		if (x & 1)
+			extra_bits++;
+		x >>= 1;
+		shifts++;
+	}
+
+	if (extra_bits)
+		shifts++;
+
+	return shifts;
+}
+
+/* Function to return the number of shifts to get a 1 in bit 0
+ */
+
+static inline u32 calc_shifts(u32 x)
+{
+	u32 shifts;
+
+	shifts = 0;
+
+	if (!x)
+		return 0;
+
+	while (!(x & 1)) {
+		x >>= 1;
+		shifts++;
+	}
+
+	return shifts;
+}
+
+/*
+ * Temporary buffer manipulations.
+ */
+
+static int yaffs_init_tmp_buffers(struct yaffs_dev *dev)
+{
+	int i;
+	u8 *buf = (u8 *) 1;
+
+	memset(dev->temp_buffer, 0, sizeof(dev->temp_buffer));
+
+	for (i = 0; buf && i < YAFFS_N_TEMP_BUFFERS; i++) {
+		dev->temp_buffer[i].in_use = 0;
+		buf = kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
+		dev->temp_buffer[i].buffer = buf;
+	}
+
+	return buf ? YAFFS_OK : YAFFS_FAIL;
+}
+
+u8 *yaffs_get_temp_buffer(struct yaffs_dev * dev)
+{
+	int i;
+
+	dev->temp_in_use++;
+	if (dev->temp_in_use > dev->max_temp)
+		dev->max_temp = dev->temp_in_use;
+
+	for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
+		if (dev->temp_buffer[i].in_use == 0) {
+			dev->temp_buffer[i].in_use = 1;
+			return dev->temp_buffer[i].buffer;
+		}
+	}
+
+	yaffs_trace(YAFFS_TRACE_BUFFERS, "Out of temp buffers");
+	/*
+	 * If we got here then we have to allocate an unmanaged one
+	 * This is not good.
+	 */
+
+	dev->unmanaged_buffer_allocs++;
+	return kmalloc(dev->data_bytes_per_chunk, GFP_NOFS);
+
+}
+
+void yaffs_release_temp_buffer(struct yaffs_dev *dev, u8 *buffer)
+{
+	int i;
+
+	dev->temp_in_use--;
+
+	for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
+		if (dev->temp_buffer[i].buffer == buffer) {
+			dev->temp_buffer[i].in_use = 0;
+			return;
+		}
+	}
+
+	if (buffer) {
+		/* assume it is an unmanaged one. */
+		yaffs_trace(YAFFS_TRACE_BUFFERS,
+			"Releasing unmanaged temp buffer");
+		kfree(buffer);
+		dev->unmanaged_buffer_deallocs++;
+	}
+
+}
+
+/*
+ * Determine if we have a managed buffer.
+ */
+int yaffs_is_managed_tmp_buffer(struct yaffs_dev *dev, const u8 *buffer)
+{
+	int i;
+
+	for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
+		if (dev->temp_buffer[i].buffer == buffer)
+			return 1;
+	}
+
+	for (i = 0; i < dev->param.n_caches; i++) {
+		if (dev->cache[i].data == buffer)
+			return 1;
+	}
+
+	if (buffer == dev->checkpt_buffer)
+		return 1;
+
+	yaffs_trace(YAFFS_TRACE_ALWAYS,
+	  "yaffs: unmaged buffer detected.");
+	return 0;
+}
+
+/*
+ * Functions for robustisizing TODO
+ *
+ */
+
+static void yaffs_handle_chunk_wr_ok(struct yaffs_dev *dev, int nand_chunk,
+				     const u8 *data,
+				     const struct yaffs_ext_tags *tags)
+{
+	dev = dev;
+	nand_chunk = nand_chunk;
+	data = data;
+	tags = tags;
+}
+
+static void yaffs_handle_chunk_update(struct yaffs_dev *dev, int nand_chunk,
+				      const struct yaffs_ext_tags *tags)
+{
+	dev = dev;
+	nand_chunk = nand_chunk;
+	tags = tags;
+}
+
+void yaffs_handle_chunk_error(struct yaffs_dev *dev,
+			      struct yaffs_block_info *bi)
+{
+	if (!bi->gc_prioritise) {
+		bi->gc_prioritise = 1;
+		dev->has_pending_prioritised_gc = 1;
+		bi->chunk_error_strikes++;
+
+		if (bi->chunk_error_strikes > 3) {
+			bi->needs_retiring = 1;	/* Too many stikes, so retire */
+			yaffs_trace(YAFFS_TRACE_ALWAYS,
+				"yaffs: Block struck out");
+
+		}
+	}
+}
+
+static void yaffs_handle_chunk_wr_error(struct yaffs_dev *dev, int nand_chunk,
+					int erased_ok)
+{
+	int flash_block = nand_chunk / dev->param.chunks_per_block;
+	struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block);
+
+	yaffs_handle_chunk_error(dev, bi);
+
+	if (erased_ok) {
+		/* Was an actual write failure,
+		 * so mark the block for retirement.*/
+		bi->needs_retiring = 1;
+		yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
+		  "**>> Block %d needs retiring", flash_block);
+	}
+
+	/* Delete the chunk */
+	yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
+	yaffs_skip_rest_of_block(dev);
+}
+
+/*
+ * Verification code
+ */
+
+/*
+ *  Simple hash function. Needs to have a reasonable spread
+ */
+
+static inline int yaffs_hash_fn(int n)
+{
+	if (n < 0)
+		n = -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.
+ */
+
+struct yaffs_obj *yaffs_root(struct yaffs_dev *dev)
+{
+	return dev->root_dir;
+}
+
+struct yaffs_obj *yaffs_lost_n_found(struct yaffs_dev *dev)
+{
+	return dev->lost_n_found;
+}
+
+/*
+ *  Erased NAND checking functions
+ */
+
+int yaffs_check_ff(u8 *buffer, int n_bytes)
+{
+	/* Horrible, slow implementation */
+	while (n_bytes--) {
+		if (*buffer != 0xff)
+			return 0;
+		buffer++;
+	}
+	return 1;
+}
+
+static int yaffs_check_chunk_erased(struct yaffs_dev *dev, int nand_chunk)
+{
+	int retval = YAFFS_OK;
+	u8 *data = yaffs_get_temp_buffer(dev);
+	struct yaffs_ext_tags tags;
+
+	yaffs_rd_chunk_tags_nand(dev, nand_chunk, data, &tags);
+
+	if (tags.ecc_result > YAFFS_ECC_RESULT_NO_ERROR)
+		retval = YAFFS_FAIL;
+
+	if (!yaffs_check_ff(data, dev->data_bytes_per_chunk) ||
+		tags.chunk_used) {
+		yaffs_trace(YAFFS_TRACE_NANDACCESS,
+			"Chunk %d not erased", nand_chunk);
+		retval = YAFFS_FAIL;
+	}
+
+	yaffs_release_temp_buffer(dev, data);
+
+	return retval;
+
+}
+
+static int yaffs_verify_chunk_written(struct yaffs_dev *dev,
+				      int nand_chunk,
+				      const u8 *data,
+				      struct yaffs_ext_tags *tags)
+{
+	int retval = YAFFS_OK;
+	struct yaffs_ext_tags temp_tags;
+	u8 *buffer = yaffs_get_temp_buffer(dev);
+
+	yaffs_rd_chunk_tags_nand(dev, nand_chunk, buffer, &temp_tags);
+	if (memcmp(buffer, data, dev->data_bytes_per_chunk) ||
+	    temp_tags.obj_id != tags->obj_id ||
+	    temp_tags.chunk_id != tags->chunk_id ||
+	    temp_tags.n_bytes != tags->n_bytes)
+		retval = YAFFS_FAIL;
+
+	yaffs_release_temp_buffer(dev, buffer);
+
+	return retval;
+}
+
+
+int yaffs_check_alloc_available(struct yaffs_dev *dev, int n_chunks)
+{
+	int reserved_chunks;
+	int reserved_blocks = dev->param.n_reserved_blocks;
+	int checkpt_blocks;
+
+	checkpt_blocks = yaffs_calc_checkpt_blocks_required(dev);
+
+	reserved_chunks =
+	    (reserved_blocks + checkpt_blocks) * dev->param.chunks_per_block;
+
+	return (dev->n_free_chunks > (reserved_chunks + n_chunks));
+}
+
+static int yaffs_find_alloc_block(struct yaffs_dev *dev)
+{
+	int i;
+	struct yaffs_block_info *bi;
+
+	if (dev->n_erased_blocks < 1) {
+		/* Hoosterman we've got a problem.
+		 * Can't get space to gc
+		 */
+		yaffs_trace(YAFFS_TRACE_ERROR,
+		  "yaffs tragedy: no more erased blocks");
+
+		return -1;
+	}
+
+	/* Find an empty block. */
+
+	for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
+		dev->alloc_block_finder++;
+		if (dev->alloc_block_finder < dev->internal_start_block
+		    || dev->alloc_block_finder > dev->internal_end_block) {
+			dev->alloc_block_finder = dev->internal_start_block;
+		}
+
+		bi = yaffs_get_block_info(dev, dev->alloc_block_finder);
+
+		if (bi->block_state == YAFFS_BLOCK_STATE_EMPTY) {
+			bi->block_state = YAFFS_BLOCK_STATE_ALLOCATING;
+			dev->seq_number++;
+			bi->seq_number = dev->seq_number;
+			dev->n_erased_blocks--;
+			yaffs_trace(YAFFS_TRACE_ALLOCATE,
+			  "Allocated block %d, seq  %d, %d left" ,
+			   dev->alloc_block_finder, dev->seq_number,
+			   dev->n_erased_blocks);
+			return dev->alloc_block_finder;
+		}
+	}
+
+	yaffs_trace(YAFFS_TRACE_ALWAYS,
+		"yaffs tragedy: no more erased blocks, but there should have been %d",
+		dev->n_erased_blocks);
+
+	return -1;
+}
+
+static int yaffs_alloc_chunk(struct yaffs_dev *dev, int use_reserver,
+			     struct yaffs_block_info **block_ptr)
+{
+	int ret_val;
+	struct yaffs_block_info *bi;
+
+	if (dev->alloc_block < 0) {
+		/* Get next block to allocate off */
+		dev->alloc_block = yaffs_find_alloc_block(dev);
+		dev->alloc_page = 0;
+	}
+
+	if (!use_reserver && !yaffs_check_alloc_available(dev, 1)) {
+		/* No space unless we're allowed to use the reserve. */
+		return -1;
+	}
+
+	if (dev->n_erased_blocks < dev->param.n_reserved_blocks
+	    && dev->alloc_page == 0)
+		yaffs_trace(YAFFS_TRACE_ALLOCATE, "Allocating reserve");
+
+	/* Next page please.... */
+	if (dev->alloc_block >= 0) {
+		bi = yaffs_get_block_info(dev, dev->alloc_block);
+
+		ret_val = (dev->alloc_block * dev->param.chunks_per_block) +
+		    dev->alloc_page;
+		bi->pages_in_use++;
+		yaffs_set_chunk_bit(dev, dev->alloc_block, dev->alloc_page);
+
+		dev->alloc_page++;
+
+		dev->n_free_chunks--;
+
+		/* If the block is full set the state to full */
+		if (dev->alloc_page >= dev->param.chunks_per_block) {
+			bi->block_state = YAFFS_BLOCK_STATE_FULL;
+			dev->alloc_block = -1;
+		}
+
+		if (block_ptr)
+			*block_ptr = bi;
+
+		return ret_val;
+	}
+
+	yaffs_trace(YAFFS_TRACE_ERROR,
+		"!!!!!!!!! Allocator out !!!!!!!!!!!!!!!!!");
+
+	return -1;
+}
+
+static int yaffs_get_erased_chunks(struct yaffs_dev *dev)
+{
+	int n;
+
+	n = dev->n_erased_blocks * dev->param.chunks_per_block;
+
+	if (dev->alloc_block > 0)
+		n += (dev->param.chunks_per_block - dev->alloc_page);
+
+	return n;
+
+}
+
+/*
+ * yaffs_skip_rest_of_block() skips over the rest of the allocation block
+ * if we don't want to write to it.
+ */
+void yaffs_skip_rest_of_block(struct yaffs_dev *dev)
+{
+	struct yaffs_block_info *bi;
+
+	if (dev->alloc_block > 0) {
+		bi = yaffs_get_block_info(dev, dev->alloc_block);
+		if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING) {
+			bi->block_state = YAFFS_BLOCK_STATE_FULL;
+			dev->alloc_block = -1;
+		}
+	}
+}
+
+static int yaffs_write_new_chunk(struct yaffs_dev *dev,
+				 const u8 *data,
+				 struct yaffs_ext_tags *tags, int use_reserver)
+{
+	int attempts = 0;
+	int write_ok = 0;
+	int chunk;
+
+	yaffs2_checkpt_invalidate(dev);
+
+	do {
+		struct yaffs_block_info *bi = 0;
+		int erased_ok = 0;
+
+		chunk = yaffs_alloc_chunk(dev, use_reserver, &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.
+		 *
+		 * Mods to the above
+		 * If an erase check fails or the write fails we skip the
+		 * rest of the block.
+		 */
+
+		/* let's give it a try */
+		attempts++;
+
+		if (dev->param.always_check_erased)
+			bi->skip_erased_check = 0;
+
+		if (!bi->skip_erased_check) {
+			erased_ok = yaffs_check_chunk_erased(dev, chunk);
+			if (erased_ok != YAFFS_OK) {
+				yaffs_trace(YAFFS_TRACE_ERROR,
+				  "**>> yaffs chunk %d was not erased",
+				  chunk);
+
+				/* If not erased, delete this one,
+				 * skip rest of block and
+				 * try another chunk */
+				yaffs_chunk_del(dev, chunk, 1, __LINE__);
+				yaffs_skip_rest_of_block(dev);
+				continue;
+			}
+		}
+
+		write_ok = yaffs_wr_chunk_tags_nand(dev, chunk, data, tags);
+
+		if (!bi->skip_erased_check)
+			write_ok =
+			    yaffs_verify_chunk_written(dev, chunk, data, tags);
+
+		if (write_ok != YAFFS_OK) {
+			/* Clean up aborted write, skip to next block and
+			 * try another chunk */
+			yaffs_handle_chunk_wr_error(dev, chunk, erased_ok);
+			continue;
+		}
+
+		bi->skip_erased_check = 1;
+
+		/* Copy the data into the robustification buffer */
+		yaffs_handle_chunk_wr_ok(dev, chunk, data, tags);
+
+	} while (write_ok != YAFFS_OK &&
+		 (yaffs_wr_attempts <= 0 || attempts <= yaffs_wr_attempts));
+
+	if (!write_ok)
+		chunk = -1;
+
+	if (attempts > 1) {
+		yaffs_trace(YAFFS_TRACE_ERROR,
+			"**>> yaffs write required %d attempts",
+			attempts);
+		dev->n_retried_writes += (attempts - 1);
+	}
+
+	return chunk;
+}
+
+/*
+ * Block retiring for handling a broken block.
+ */
+
+static void yaffs_retire_block(struct yaffs_dev *dev, int flash_block)
+{
+	struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block);
+
+	yaffs2_checkpt_invalidate(dev);
+
+	yaffs2_clear_oldest_dirty_seq(dev, bi);
+
+	if (yaffs_mark_bad(dev, flash_block) != YAFFS_OK) {
+		if (yaffs_erase_block(dev, flash_block) != YAFFS_OK) {
+			yaffs_trace(YAFFS_TRACE_ALWAYS,
+				"yaffs: Failed to mark bad and erase block %d",
+				flash_block);
+		} else {
+			struct yaffs_ext_tags tags;
+			int chunk_id =
+			    flash_block * dev->param.chunks_per_block;
+
+			u8 *buffer = yaffs_get_temp_buffer(dev);
+
+			memset(buffer, 0xff, dev->data_bytes_per_chunk);
+			memset(&tags, 0, sizeof(tags));
+			tags.seq_number = YAFFS_SEQUENCE_BAD_BLOCK;
+			if (dev->param.write_chunk_tags_fn(dev, chunk_id -
+							   dev->chunk_offset,
+							   buffer,
+							   &tags) != YAFFS_OK)
+				yaffs_trace(YAFFS_TRACE_ALWAYS,
+					"yaffs: Failed to write bad block marker to block %d",
+					flash_block);
+
+			yaffs_release_temp_buffer(dev, buffer);
+		}
+	}
+
+	bi->block_state = YAFFS_BLOCK_STATE_DEAD;
+	bi->gc_prioritise = 0;
+	bi->needs_retiring = 0;
+
+	dev->n_retired_blocks++;
+}
+
+/*---------------- Name handling functions ------------*/
+
+static u16 yaffs_calc_name_sum(const YCHAR *name)
+{
+	u16 sum = 0;
+	u16 i = 1;
+
+	if (!name)
+		return 0;
+
+	while ((*name) && i < (YAFFS_MAX_NAME_LENGTH / 2)) {
+
+		/* 0x1f mask is case insensitive */
+		sum += ((*name) & 0x1f) * i;
+		i++;
+		name++;
+	}
+	return sum;
+}
+
+void yaffs_set_obj_name(struct yaffs_obj *obj, const YCHAR * name)
+{
+	memset(obj->short_name, 0, sizeof(obj->short_name));
+	if (name &&
+		yaffs_strnlen(name, YAFFS_SHORT_NAME_LENGTH + 1) <=
+		YAFFS_SHORT_NAME_LENGTH)
+		yaffs_strcpy(obj->short_name, name);
+	else
+		obj->short_name[0] = _Y('\0');
+	obj->sum = yaffs_calc_name_sum(name);
+}
+
+void yaffs_set_obj_name_from_oh(struct yaffs_obj *obj,
+				const struct yaffs_obj_hdr *oh)
+{
+#ifdef CONFIG_YAFFS_AUTO_UNICODE
+	YCHAR tmp_name[YAFFS_MAX_NAME_LENGTH + 1];
+	memset(tmp_name, 0, sizeof(tmp_name));
+	yaffs_load_name_from_oh(obj->my_dev, tmp_name, oh->name,
+				YAFFS_MAX_NAME_LENGTH + 1);
+	yaffs_set_obj_name(obj, tmp_name);
+#else
+	yaffs_set_obj_name(obj, oh->name);
+#endif
+}
+
+loff_t yaffs_max_file_size(struct yaffs_dev *dev)
+{
+	return ((loff_t) YAFFS_MAX_CHUNK_ID) * dev->data_bytes_per_chunk;
+}
+
+/*-------------------- TNODES -------------------
+
+ * List of spare tnodes
+ * The list is hooked together using the first pointer
+ * in the tnode.
+ */
+
+struct yaffs_tnode *yaffs_get_tnode(struct yaffs_dev *dev)
+{
+	struct yaffs_tnode *tn = yaffs_alloc_raw_tnode(dev);
+
+	if (tn) {
+		memset(tn, 0, dev->tnode_size);
+		dev->n_tnodes++;
+	}
+
+	dev->checkpoint_blocks_required = 0;	/* force recalculation */
+
+	return tn;
+}
+
+/* FreeTnode frees up a tnode and puts it back on the free list */
+static void yaffs_free_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn)
+{
+	yaffs_free_raw_tnode(dev, tn);
+	dev->n_tnodes--;
+	dev->checkpoint_blocks_required = 0;	/* force recalculation */
+}
+
+static void yaffs_deinit_tnodes_and_objs(struct yaffs_dev *dev)
+{
+	yaffs_deinit_raw_tnodes_and_objs(dev);
+	dev->n_obj = 0;
+	dev->n_tnodes = 0;
+}
+
+void yaffs_load_tnode_0(struct yaffs_dev *dev, struct yaffs_tnode *tn,
+			unsigned pos, unsigned val)
+{
+	u32 *map = (u32 *) tn;
+	u32 bit_in_map;
+	u32 bit_in_word;
+	u32 word_in_map;
+	u32 mask;
+
+	pos &= YAFFS_TNODES_LEVEL0_MASK;
+	val >>= dev->chunk_grp_bits;
+
+	bit_in_map = pos * dev->tnode_width;
+	word_in_map = bit_in_map / 32;
+	bit_in_word = bit_in_map & (32 - 1);
+
+	mask = dev->tnode_mask << bit_in_word;
+
+	map[word_in_map] &= ~mask;
+	map[word_in_map] |= (mask & (val << bit_in_word));
+
+	if (dev->tnode_width > (32 - bit_in_word)) {
+		bit_in_word = (32 - bit_in_word);
+		word_in_map++;
+		mask =
+		    dev->tnode_mask >> bit_in_word;
+		map[word_in_map] &= ~mask;
+		map[word_in_map] |= (mask & (val >> bit_in_word));
+	}
+}
+
+u32 yaffs_get_group_base(struct yaffs_dev *dev, struct yaffs_tnode *tn,
+			 unsigned pos)
+{
+	u32 *map = (u32 *) tn;
+	u32 bit_in_map;
+	u32 bit_in_word;
+	u32 word_in_map;
+	u32 val;
+
+	pos &= YAFFS_TNODES_LEVEL0_MASK;
+
+	bit_in_map = pos * dev->tnode_width;
+	word_in_map = bit_in_map / 32;
+	bit_in_word = bit_in_map & (32 - 1);
+
+	val = map[word_in_map] >> bit_in_word;
+
+	if (dev->tnode_width > (32 - bit_in_word)) {
+		bit_in_word = (32 - bit_in_word);
+		word_in_map++;
+		val |= (map[word_in_map] << bit_in_word);
+	}
+
+	val &= dev->tnode_mask;
+	val <<= dev->chunk_grp_bits;
+
+	return val;
+}
+
+/* ------------------- End of individual tnode manipulation -----------------*/
+
+/* ---------Functions to manipulate the look-up tree (made up of tnodes) ------
+ * The look up tree is represented by the top tnode and the number of top_level
+ * in the tree. 0 means only the level 0 tnode is in the tree.
+ */
+
+/* FindLevel0Tnode finds the level 0 tnode, if one exists. */
+struct yaffs_tnode *yaffs_find_tnode_0(struct yaffs_dev *dev,
+				       struct yaffs_file_var *file_struct,
+				       u32 chunk_id)
+{
+	struct yaffs_tnode *tn = file_struct->top;
+	u32 i;
+	int required_depth;
+	int level = file_struct->top_level;
+
+	dev = dev;
+
+	/* Check sane level and chunk Id */
+	if (level < 0 || level > YAFFS_TNODES_MAX_LEVEL)
+		return NULL;
+
+	if (chunk_id > YAFFS_MAX_CHUNK_ID)
+		return NULL;
+
+	/* First check we're tall enough (ie enough top_level) */
+
+	i = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
+	required_depth = 0;
+	while (i) {
+		i >>= YAFFS_TNODES_INTERNAL_BITS;
+		required_depth++;
+	}
+
+	if (required_depth > file_struct->top_level)
+		return NULL;	/* Not tall enough, so we can't find it */
+
+	/* Traverse down to level 0 */
+	while (level > 0 && tn) {
+		tn = tn->internal[(chunk_id >>
+				   (YAFFS_TNODES_LEVEL0_BITS +
+				    (level - 1) *
+				    YAFFS_TNODES_INTERNAL_BITS)) &
+				  YAFFS_TNODES_INTERNAL_MASK];
+		level--;
+	}
+
+	return tn;
+}
+
+/* add_find_tnode_0 finds the level 0 tnode if it exists,
+ * otherwise first expands the tree.
+ * This happens in two steps:
+ *  1. If the tree isn't tall enough, then make it taller.
+ *  2. Scan down the tree towards the level 0 tnode adding tnodes if required.
+ *
+ * Used when modifying the tree.
+ *
+ *  If the tn argument is NULL, then a fresh tnode will be added otherwise the
+ *  specified tn will be plugged into the ttree.
+ */
+
+struct yaffs_tnode *yaffs_add_find_tnode_0(struct yaffs_dev *dev,
+					   struct yaffs_file_var *file_struct,
+					   u32 chunk_id,
+					   struct yaffs_tnode *passed_tn)
+{
+	int required_depth;
+	int i;
+	int l;
+	struct yaffs_tnode *tn;
+	u32 x;
+
+	/* Check sane level and page Id */
+	if (file_struct->top_level < 0 ||
+	    file_struct->top_level > YAFFS_TNODES_MAX_LEVEL)
+		return NULL;
+
+	if (chunk_id > YAFFS_MAX_CHUNK_ID)
+		return NULL;
+
+	/* First check we're tall enough (ie enough top_level) */
+
+	x = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
+	required_depth = 0;
+	while (x) {
+		x >>= YAFFS_TNODES_INTERNAL_BITS;
+		required_depth++;
+	}
+
+	if (required_depth > file_struct->top_level) {
+		/* Not tall enough, gotta make the tree taller */
+		for (i = file_struct->top_level; i < required_depth; i++) {
+
+			tn = yaffs_get_tnode(dev);
+
+			if (tn) {
+				tn->internal[0] = file_struct->top;
+				file_struct->top = tn;
+				file_struct->top_level++;
+			} else {
+				yaffs_trace(YAFFS_TRACE_ERROR,
+					"yaffs: no more tnodes");
+				return NULL;
+			}
+		}
+	}
+
+	/* Traverse down to level 0, adding anything we need */
+
+	l = file_struct->top_level;
+	tn = file_struct->top;
+
+	if (l > 0) {
+		while (l > 0 && tn) {
+			x = (chunk_id >>
+			     (YAFFS_TNODES_LEVEL0_BITS +
+			      (l - 1) * YAFFS_TNODES_INTERNAL_BITS)) &
+			    YAFFS_TNODES_INTERNAL_MASK;
+
+			if ((l > 1) && !tn->internal[x]) {
+				/* Add missing non-level-zero tnode */
+				tn->internal[x] = yaffs_get_tnode(dev);
+				if (!tn->internal[x])
+					return NULL;
+			} else if (l == 1) {
+				/* Looking from level 1 at level 0 */
+				if (passed_tn) {
+					/* If we already have one, release it */
+					if (tn->internal[x])
+						yaffs_free_tnode(dev,
+							tn->internal[x]);
+					tn->internal[x] = passed_tn;
+
+				} else if (!tn->internal[x]) {
+					/* Don't have one, none passed in */
+					tn->internal[x] = yaffs_get_tnode(dev);
+					if (!tn->internal[x])
+						return NULL;
+				}
+			}
+
+			tn = tn->internal[x];
+			l--;
+		}
+	} else {
+		/* top is level 0 */
+		if (passed_tn) {
+			memcpy(tn, passed_tn,
+			       (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8);
+			yaffs_free_tnode(dev, passed_tn);
+		}
+	}
+
+	return tn;
+}
+
+static int yaffs_tags_match(const struct yaffs_ext_tags *tags, int obj_id,
+			    int chunk_obj)
+{
+	return (tags->chunk_id == chunk_obj &&
+		tags->obj_id == obj_id &&
+		!tags->is_deleted) ? 1 : 0;
+
+}
+
+static int yaffs_find_chunk_in_group(struct yaffs_dev *dev, int the_chunk,
+					struct yaffs_ext_tags *tags, int obj_id,
+					int inode_chunk)
+{
+	int j;
+
+	for (j = 0; the_chunk && j < dev->chunk_grp_size; j++) {
+		if (yaffs_check_chunk_bit
+		    (dev, the_chunk / dev->param.chunks_per_block,
+		     the_chunk % dev->param.chunks_per_block)) {
+
+			if (dev->chunk_grp_size == 1)
+				return the_chunk;
+			else {
+				yaffs_rd_chunk_tags_nand(dev, the_chunk, NULL,
+							 tags);
+				if (yaffs_tags_match(tags,
+							obj_id, inode_chunk)) {
+					/* found it; */
+					return the_chunk;
+				}
+			}
+		}
+		the_chunk++;
+	}
+	return -1;
+}
+
+static int yaffs_find_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
+				    struct yaffs_ext_tags *tags)
+{
+	/*Get the Tnode, then get the level 0 offset chunk offset */
+	struct yaffs_tnode *tn;
+	int the_chunk = -1;
+	struct yaffs_ext_tags local_tags;
+	int ret_val = -1;
+	struct yaffs_dev *dev = in->my_dev;
+
+	if (!tags) {
+		/* Passed a NULL, so use our own tags space */
+		tags = &local_tags;
+	}
+
+	tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
+
+	if (!tn)
+		return ret_val;
+
+	the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
+
+	ret_val = yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
+					      inode_chunk);
+	return ret_val;
+}
+
+static int yaffs_find_del_file_chunk(struct yaffs_obj *in, int inode_chunk,
+				     struct yaffs_ext_tags *tags)
+{
+	/* Get the Tnode, then get the level 0 offset chunk offset */
+	struct yaffs_tnode *tn;
+	int the_chunk = -1;
+	struct yaffs_ext_tags local_tags;
+	struct yaffs_dev *dev = in->my_dev;
+	int ret_val = -1;
+
+	if (!tags) {
+		/* Passed a NULL, so use our own tags space */
+		tags = &local_tags;
+	}
+
+	tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
+
+	if (!tn)
+		return ret_val;
+
+	the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
+
+	ret_val = yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
+					      inode_chunk);
+
+	/* Delete the entry in the filestructure (if found) */
+	if (ret_val != -1)
+		yaffs_load_tnode_0(dev, tn, inode_chunk, 0);
+
+	return ret_val;
+}
+
+int yaffs_put_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
+			    int nand_chunk, int in_scan)
+{
+	/* NB in_scan is zero unless scanning.
+	 * For forward scanning, in_scan is > 0;
+	 * for backward scanning in_scan is < 0
+	 *
+	 * nand_chunk = 0 is a dummy insert to make sure the tnodes are there.
+	 */
+
+	struct yaffs_tnode *tn;
+	struct yaffs_dev *dev = in->my_dev;
+	int existing_cunk;
+	struct yaffs_ext_tags existing_tags;
+	struct yaffs_ext_tags new_tags;
+	unsigned existing_serial, new_serial;
+
+	if (in->variant_type != YAFFS_OBJECT_TYPE_FILE) {
+		/* Just ignore an attempt at putting a chunk into a non-file
+		 * during scanning.
+		 * If it is not during Scanning then something went wrong!
+		 */
+		if (!in_scan) {
+			yaffs_trace(YAFFS_TRACE_ERROR,
+				"yaffs tragedy:attempt to put data chunk into a non-file"
+				);
+			BUG();
+		}
+
+		yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
+		return YAFFS_OK;
+	}
+
+	tn = yaffs_add_find_tnode_0(dev,
+				    &in->variant.file_variant,
+				    inode_chunk, NULL);
+	if (!tn)
+		return YAFFS_FAIL;
+
+	if (!nand_chunk)
+		/* Dummy insert, bail now */
+		return YAFFS_OK;
+
+	existing_cunk = yaffs_get_group_base(dev, tn, inode_chunk);
+
+	if (in_scan != 0) {
+		/* If we're scanning then we need to test for duplicates
+		 * NB This does not need to be efficient since it should only
+		 * happen when the power fails during a write, then only one
+		 * chunk should ever be affected.
+		 *
+		 * Correction for YAFFS2: This could happen quite a lot and we
+		 * need to think about efficiency! TODO
+		 * Update: For backward scanning we don't need to re-read tags
+		 * so this is quite cheap.
+		 */
+
+		if (existing_cunk > 0) {
+			/* NB Right now existing chunk will not be real
+			 * chunk_id if the chunk group size > 1
+			 * thus we have to do a FindChunkInFile to get the
+			 * real chunk id.
+			 *
+			 * We have a duplicate now we need to decide which
+			 * one to use:
+			 *
+			 * Backwards scanning YAFFS2: The old one is what
+			 * we use, dump the new one.
+			 * YAFFS1: Get both sets of tags and compare serial
+			 * numbers.
+			 */
+
+			if (in_scan > 0) {
+				/* Only do this for forward scanning */
+				yaffs_rd_chunk_tags_nand(dev,
+							 nand_chunk,
+							 NULL, &new_tags);
+
+				/* Do a proper find */
+				existing_cunk =
+				    yaffs_find_chunk_in_file(in, inode_chunk,
+							     &existing_tags);
+			}
+
+			if (existing_cunk <= 0) {
+				/*Hoosterman - how did this happen? */
+
+				yaffs_trace(YAFFS_TRACE_ERROR,
+					"yaffs tragedy: existing chunk < 0 in scan"
+					);
+
+			}
+
+			/* NB The deleted flags should be false, otherwise
+			 * the chunks will not be loaded during a scan
+			 */
+
+			if (in_scan > 0) {
+				new_serial = new_tags.serial_number;
+				existing_serial = existing_tags.serial_number;
+			}
+
+			if ((in_scan > 0) &&
+			    (existing_cunk <= 0 ||
+			     ((existing_serial + 1) & 3) == new_serial)) {
+				/* Forward scanning.
+				 * Use new
+				 * Delete the old one and drop through to
+				 * update the tnode
+				 */
+				yaffs_chunk_del(dev, existing_cunk, 1,
+						__LINE__);
+			} else {
+				/* Backward scanning or we want to use the
+				 * existing one
+				 * Delete the new one and return early so that
+				 * the tnode isn't changed
+				 */
+				yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
+				return YAFFS_OK;
+			}
+		}
+
+	}
+
+	if (existing_cunk == 0)
+		in->n_data_chunks++;
+
+	yaffs_load_tnode_0(dev, tn, inode_chunk, nand_chunk);
+
+	return YAFFS_OK;
+}
+
+static void yaffs_soft_del_chunk(struct yaffs_dev *dev, int chunk)
+{
+	struct yaffs_block_info *the_block;
+	unsigned block_no;
+
+	yaffs_trace(YAFFS_TRACE_DELETION, "soft delete chunk %d", chunk);
+
+	block_no = chunk / dev->param.chunks_per_block;
+	the_block = yaffs_get_block_info(dev, block_no);
+	if (the_block) {
+		the_block->soft_del_pages++;
+		dev->n_free_chunks++;
+		yaffs2_update_oldest_dirty_seq(dev, block_no, the_block);
+	}
+}
+
+/* SoftDeleteWorker scans backwards through the tnode tree and soft deletes all
+ * the chunks in the file.
+ * All soft deleting does is increment the block's softdelete count and pulls
+ * the chunk out of the tnode.
+ * Thus, essentially this is the same as DeleteWorker except that the chunks
+ * are soft deleted.
+ */
+
+static int yaffs_soft_del_worker(struct yaffs_obj *in, struct yaffs_tnode *tn,
+				 u32 level, int chunk_offset)
+{
+	int i;
+	int the_chunk;
+	int all_done = 1;
+	struct yaffs_dev *dev = in->my_dev;
+
+	if (!tn)
+		return 1;
+
+	if (level > 0) {
+		for (i = YAFFS_NTNODES_INTERNAL - 1;
+			all_done && i >= 0;
+			i--) {
+			if (tn->internal[i]) {
+				all_done =
+				    yaffs_soft_del_worker(in,
+					tn->internal[i],
+					level - 1,
+					(chunk_offset <<
+					YAFFS_TNODES_INTERNAL_BITS)
+					+ i);
+				if (all_done) {
+					yaffs_free_tnode(dev,
+						tn->internal[i]);
+					tn->internal[i] = NULL;
+				} else {
+					/* Can this happen? */
+				}
+			}
+		}
+		return (all_done) ? 1 : 0;
+	}
+
+	/* level 0 */
+	 for (i = YAFFS_NTNODES_LEVEL0 - 1; i >= 0; i--) {
+		the_chunk = yaffs_get_group_base(dev, tn, i);
+		if (the_chunk) {
+			yaffs_soft_del_chunk(dev, the_chunk);
+			yaffs_load_tnode_0(dev, tn, i, 0);
+		}
+	}
+	return 1;
+}
+
+static void yaffs_remove_obj_from_dir(struct yaffs_obj *obj)
+{
+	struct yaffs_dev *dev = obj->my_dev;
+	struct yaffs_obj *parent;
+
+	yaffs_verify_obj_in_dir(obj);
+	parent = obj->parent;
+
+	yaffs_verify_dir(parent);
+
+	if (dev && dev->param.remove_obj_fn)
+		dev->param.remove_obj_fn(obj);
+
+	list_del_init(&obj->siblings);
+	obj->parent = NULL;
+
+	yaffs_verify_dir(parent);
+}
+
+void yaffs_add_obj_to_dir(struct yaffs_obj *directory, struct yaffs_obj *obj)
+{
+	if (!directory) {
+		yaffs_trace(YAFFS_TRACE_ALWAYS,
+			"tragedy: Trying to add an object to a null pointer directory"
+			);
+		BUG();
+		return;
+	}
+	if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
+		yaffs_trace(YAFFS_TRACE_ALWAYS,
+			"tragedy: Trying to add an object to a non-directory"
+			);
+		BUG();
+	}
+
+	if (obj->siblings.prev == NULL) {
+		/* Not initialised */
+		BUG();
+	}
+
+	yaffs_verify_dir(directory);
+
+	yaffs_remove_obj_from_dir(obj);
+
+	/* Now add it */
+	list_add(&obj->siblings, &directory->variant.dir_variant.children);
+	obj->parent = directory;
+
+	if (directory == obj->my_dev->unlinked_dir
+	    || directory == obj->my_dev->del_dir) {
+		obj->unlinked = 1;
+		obj->my_dev->n_unlinked_files++;
+		obj->rename_allowed = 0;
+	}
+
+	yaffs_verify_dir(directory);
+	yaffs_verify_obj_in_dir(obj);
+}
+
+static int yaffs_change_obj_name(struct yaffs_obj *obj,
+				 struct yaffs_obj *new_dir,
+				 const YCHAR *new_name, int force, int shadows)
+{
+	int unlink_op;
+	int del_op;
+	struct yaffs_obj *existing_target;
+
+	if (new_dir == NULL)
+		new_dir = obj->parent;	/* use the old directory */
+
+	if (new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
+		yaffs_trace(YAFFS_TRACE_ALWAYS,
+			"tragedy: yaffs_change_obj_name: new_dir is not a directory"
+			);
+		BUG();
+	}
+
+	unlink_op = (new_dir == obj->my_dev->unlinked_dir);
+	del_op = (new_dir == obj->my_dev->del_dir);
+
+	existing_target = yaffs_find_by_name(new_dir, new_name);
+
+	/* If the object is a file going into the unlinked directory,
+	 *   then it is OK to just stuff it in since duplicate names are OK.
+	 *   else only proceed if the new name does not exist and we're putting
+	 *   it into a directory.
+	 */
+	if (!(unlink_op || del_op || force ||
+	      shadows > 0 || !existing_target) ||
+	      new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
+		return YAFFS_FAIL;
+
+	yaffs_set_obj_name(obj, new_name);
+	obj->dirty = 1;
+	yaffs_add_obj_to_dir(new_dir, obj);
+
+	if (unlink_op)
+		obj->unlinked = 1;
+
+	/* If it is a deletion then we mark it as a shrink for gc  */
+	if (yaffs_update_oh(obj, new_name, 0, del_op, shadows, NULL) >= 0)
+		return YAFFS_OK;
+
+	return YAFFS_FAIL;
+}
+
+/*------------------------ Short Operations Cache ------------------------------
+ *   In many situations where there is no high level buffering  a lot of
+ *   reads might be short sequential reads, and a lot of writes may be short
+ *   sequential writes. eg. scanning/writing a jpeg file.
+ *   In these cases, a short read/write cache can provide a huge perfomance
+ *   benefit with dumb-as-a-rock code.
+ *   In Linux, the page cache provides read buffering and the short op cache
+ *   provides write buffering.
+ *
+ *   There are a small number (~10) of cache chunks per device so that we don't
+ *   need a very intelligent search.
+ */
+
+static int yaffs_obj_cache_dirty(struct yaffs_obj *obj)
+{
+	struct yaffs_dev *dev = obj->my_dev;
+	int i;
+	struct yaffs_cache *cache;
+	int n_caches = obj->my_dev->param.n_caches;
+
+	for (i = 0; i < n_caches; i++) {
+		cache = &dev->cache[i];
+		if (cache->object == obj && cache->dirty)
+			return 1;
+	}
+
+	return 0;
+}
+
+static void yaffs_flush_file_cache(struct yaffs_obj *obj)
+{
+	struct yaffs_dev *dev = obj->my_dev;
+	int lowest = -99;	/* Stop compiler whining. */
+	int i;
+	struct yaffs_cache *cache;
+	int chunk_written = 0;
+	int n_caches = obj->my_dev->param.n_caches;
+
+	if (n_caches < 1)
+		return;
+	do {
+		cache = NULL;
+
+		/* Find the lowest dirty chunk for this object */
+		for (i = 0; i < n_caches; i++) {
+			if (dev->cache[i].object == obj &&
+			    dev->cache[i].dirty) {
+				if (!cache ||
+				    dev->cache[i].chunk_id < lowest) {
+					cache = &dev->cache[i];
+					lowest = cache->chunk_id;
+				}
+			}
+		}
+
+		if (cache && !cache->locked) {
+			/* Write it out and free it up */
+			chunk_written =
+			    yaffs_wr_data_obj(cache->object,
+					      cache->chunk_id,
+					      cache->data,
+					      cache->n_bytes, 1);
+			cache->dirty = 0;
+			cache->object = NULL;
+		}
+	} while (cache && chunk_written > 0);
+
+	if (cache)
+		/* Hoosterman, disk full while writing cache out. */
+		yaffs_trace(YAFFS_TRACE_ERROR,
+			"yaffs tragedy: no space during cache write");
+}
+
+/*yaffs_flush_whole_cache(dev)
+ *
+ *
+ */
+
+void yaffs_flush_whole_cache(struct yaffs_dev *dev)
+{
+	struct yaffs_obj *obj;
+	int n_caches = dev->param.n_caches;
+	int i;
+
+	/* Find a dirty object in the cache and flush it...
+	 * until there are no further dirty objects.
+	 */
+	do {
+		obj = NULL;
+		for (i = 0; i < n_caches && !obj; i++) {
+			if (dev->cache[i].object && dev->cache[i].dirty)
+				obj = dev->cache[i].object;
+		}
+		if (obj)
+			yaffs_flush_file_cache(obj);
+	} while (obj);
+
+}
+
+/* Grab us a cache chunk for use.
+ * First look for an empty one.
+ * Then look for the least recently used non-dirty one.
+ * Then look for the least recently used dirty one...., flush and look again.
+ */
+static struct yaffs_cache *yaffs_grab_chunk_worker(struct yaffs_dev *dev)
+{
+	int i;
+
+	if (dev->param.n_caches > 0) {
+		for (i = 0; i < dev->param.n_caches; i++) {
+			if (!dev->cache[i].object)
+				return &dev->cache[i];
+		}
+	}
+	return NULL;
+}
+
+static struct yaffs_cache *yaffs_grab_chunk_cache(struct yaffs_dev *dev)
+{
+	struct yaffs_cache *cache;
+	struct yaffs_obj *the_obj;
+	int usage;
+	int i;
+
+	if (dev->param.n_caches < 1)
+		return NULL;
+
+	/* Try find a non-dirty one... */
+
+	cache = yaffs_grab_chunk_worker(dev);
+
+	if (!cache) {
+		/* They were all dirty, find the LRU object and flush
+		 * its cache, then  find again.
+		 * NB what's here is not very accurate,
+		 * we actually flush the object with the LRU chunk.
+		 */
+
+		/* With locking we can't assume we can use entry zero,
+		 * Set the_obj to a valid pointer for Coverity. */
+		the_obj = dev->cache[0].object;
+		usage = -1;
+		cache = NULL;
+
+		for (i = 0; i < dev->param.n_caches; i++) {
+			if (dev->cache[i].object &&
+			    !dev->cache[i].locked &&
+			    (dev->cache[i].last_use < usage ||
+			    !cache)) {
+				usage = dev->cache[i].last_use;
+				the_obj = dev->cache[i].object;
+				cache = &dev->cache[i];
+			}
+		}
+
+		if (!cache || cache->dirty) {
+			/* Flush and try again */
+			yaffs_flush_file_cache(the_obj);
+			cache = yaffs_grab_chunk_worker(dev);
+		}
+	}
+	return cache;
+}
+
+/* Find a cached chunk */
+static struct yaffs_cache *yaffs_find_chunk_cache(const struct yaffs_obj *obj,
+						  int chunk_id)
+{
+	struct yaffs_dev *dev = obj->my_dev;
+	int i;
+
+	if (dev->param.n_caches < 1)
+		return NULL;
+
+	for (i = 0; i < dev->param.n_caches; i++) {
+		if (dev->cache[i].object == obj &&
+		    dev->cache[i].chunk_id == chunk_id) {
+			dev->cache_hits++;
+
+			return &dev->cache[i];
+		}
+	}
+	return NULL;
+}
+
+/* Mark the chunk for the least recently used algorithym */
+static void yaffs_use_cache(struct yaffs_dev *dev, struct yaffs_cache *cache,
+			    int is_write)
+{
+	int i;
+
+	if (dev->param.n_caches < 1)
+		return;
+
+	if (dev->cache_last_use < 0 ||
+		dev->cache_last_use > 100000000) {
+		/* Reset the cache usages */
+		for (i = 1; i < dev->param.n_caches; i++)
+			dev->cache[i].last_use = 0;
+
+		dev->cache_last_use = 0;
+	}
+	dev->cache_last_use++;
+	cache->last_use = dev->cache_last_use;
+
+	if (is_write)
+		cache->dirty = 1;
+}
+
+/* Invalidate a single cache page.
+ * Do this when a whole page gets written,
+ * ie the short cache for this page is no longer valid.
+ */
+static void yaffs_invalidate_chunk_cache(struct yaffs_obj *object, int chunk_id)
+{
+	struct yaffs_cache *cache;
+
+	if (object->my_dev->param.n_caches > 0) {
+		cache = yaffs_find_chunk_cache(object, chunk_id);
+
+		if (cache)
+			cache->object = NULL;
+	}
+}
+
+/* Invalidate all the cache pages associated with this object
+ * Do this whenever ther file is deleted or resized.
+ */
+static void yaffs_invalidate_whole_cache(struct yaffs_obj *in)
+{
+	int i;
+	struct yaffs_dev *dev = in->my_dev;
+
+	if (dev->param.n_caches > 0) {
+		/* Invalidate it. */
+		for (i = 0; i < dev->param.n_caches; i++) {
+			if (dev->cache[i].object == in)
+				dev->cache[i].object = NULL;
+		}
+	}
+}
+
+static void yaffs_unhash_obj(struct yaffs_obj *obj)
+{
+	int bucket;
+	struct yaffs_dev *dev = obj->my_dev;
+
+	/* If it is still linked into the bucket list, free from the list */
+	if (!list_empty(&obj->hash_link)) {
+		list_del_init(&obj->hash_link);
+		bucket = yaffs_hash_fn(obj->obj_id);
+		dev->obj_bucket[bucket].count--;
+	}
+}
+
+/*  FreeObject frees up a Object and puts it back on the free list */
+static void yaffs_free_obj(struct yaffs_obj *obj)
+{
+	struct yaffs_dev *dev;
+
+	if (!obj) {
+		BUG();
+		return;
+	}
+	dev = obj->my_dev;
+	yaffs_trace(YAFFS_TRACE_OS, "FreeObject %p inode %p",
+		obj, obj->my_inode);
+	if (obj->parent)
+		BUG();
+	if (!list_empty(&obj->siblings))
+		BUG();
+
+	if (obj->my_inode) {
+		/* We're still hooked up to a cached inode.
+		 * Don't delete now, but mark for later deletion
+		 */
+		obj->defered_free = 1;
+		return;
+	}
+
+	yaffs_unhash_obj(obj);
+
+	yaffs_free_raw_obj(dev, obj);
+	dev->n_obj--;
+	dev->checkpoint_blocks_required = 0;	/* force recalculation */
+}
+
+void yaffs_handle_defered_free(struct yaffs_obj *obj)
+{
+	if (obj->defered_free)
+		yaffs_free_obj(obj);
+}
+
+static int yaffs_generic_obj_del(struct yaffs_obj *in)
+{
+	/* Iinvalidate the file's data in the cache, without flushing. */
+	yaffs_invalidate_whole_cache(in);
+
+	if (in->my_dev->param.is_yaffs2 && in->parent != in->my_dev->del_dir) {
+		/* Move to unlinked directory so we have a deletion record */
+		yaffs_change_obj_name(in, in->my_dev->del_dir, _Y("deleted"), 0,
+				      0);
+	}
+
+	yaffs_remove_obj_from_dir(in);
+	yaffs_chunk_del(in->my_dev, in->hdr_chunk, 1, __LINE__);
+	in->hdr_chunk = 0;
+
+	yaffs_free_obj(in);
+	return YAFFS_OK;
+
+}
+
+static void yaffs_soft_del_file(struct yaffs_obj *obj)
+{
+	if (!obj->deleted ||
+	    obj->variant_type != YAFFS_OBJECT_TYPE_FILE ||
+	    obj->soft_del)
+		return;
+
+	if (obj->n_data_chunks <= 0) {
+		/* Empty file with no duplicate object headers,
+		 * just delete it immediately */
+		yaffs_free_tnode(obj->my_dev, obj->variant.file_variant.top);
+		obj->variant.file_variant.top = NULL;
+		yaffs_trace(YAFFS_TRACE_TRACING,
+			"yaffs: Deleting empty file %d",
+			obj->obj_id);
+		yaffs_generic_obj_del(obj);
+	} else {
+		yaffs_soft_del_worker(obj,
+				      obj->variant.file_variant.top,
+				      obj->variant.
+				      file_variant.top_level, 0);
+		obj->soft_del = 1;
+	}
+}
+
+/* Pruning removes any part of the file structure tree that is beyond the
+ * bounds of the file (ie that does not point to chunks).
+ *
+ * A file should only get pruned when its size is reduced.
+ *
+ * Before pruning, the chunks must be pulled from the tree and the
+ * level 0 tnode entries must be zeroed out.
+ * Could also use this for file deletion, but that's probably better handled
+ * by a special case.
+ *
+ * This function is recursive. For levels > 0 the function is called again on
+ * any sub-tree. For level == 0 we just check if the sub-tree has data.
+ * If there is no data in a subtree then it is pruned.
+ */
+
+static struct yaffs_tnode *yaffs_prune_worker(struct yaffs_dev *dev,
+					      struct yaffs_tnode *tn, u32 level,
+					      int del0)
+{
+	int i;
+	int has_data;
+
+	if (!tn)
+		return tn;
+
+	has_data = 0;
+
+	if (level > 0) {
+		for (i = 0; i < YAFFS_NTNODES_INTERNAL; i++) {
+			if (tn->internal[i]) {
+				tn->internal[i] =
+				    yaffs_prune_worker(dev,
+						tn->internal[i],
+						level - 1,
+						(i == 0) ? del0 : 1);
+			}
+
+			if (tn->internal[i])
+				has_data++;
+		}
+	} else {
+		int tnode_size_u32 = dev->tnode_size / sizeof(u32);
+		u32 *map = (u32 *) tn;
+
+		for (i = 0; !has_data && i < tnode_size_u32; i++) {
+			if (map[i])
+				has_data++;
+		}
+	}
+
+	if (has_data == 0 && del0) {
+		/* Free and return NULL */
+		yaffs_free_tnode(dev, tn);
+		tn = NULL;
+	}
+	return tn;
+}
+
+static int yaffs_prune_tree(struct yaffs_dev *dev,
+			    struct yaffs_file_var *file_struct)
+{
+	int i;
+	int has_data;
+	int done = 0;
+	struct yaffs_tnode *tn;
+
+	if (file_struct->top_level < 1)
+		return YAFFS_OK;
+
+	file_struct->top =
+	   yaffs_prune_worker(dev, file_struct->top, file_struct->top_level, 0);
+
+	/* Now we have a tree with all the non-zero branches NULL but
+	 * the height is the same as it was.
+	 * Let's see if we can trim internal tnodes to shorten the tree.
+	 * We can do this if only the 0th element in the tnode is in use
+	 * (ie all the non-zero are NULL)
+	 */
+
+	while (file_struct->top_level && !done) {
+		tn = file_struct->top;
+
+		has_data = 0;
+		for (i = 1; i < YAFFS_NTNODES_INTERNAL; i++) {
+			if (tn->internal[i])
+				has_data++;
+		}
+
+		if (!has_data) {
+			file_struct->top = tn->internal[0];
+			file_struct->top_level--;
+			yaffs_free_tnode(dev, tn);
+		} else {
+			done = 1;
+		}
+	}
+
+	return YAFFS_OK;
+}
+
+/*-------------------- End of File Structure functions.-------------------*/
+
+/* alloc_empty_obj gets us a clean Object.*/
+static struct yaffs_obj *yaffs_alloc_empty_obj(struct yaffs_dev *dev)
+{
+	struct yaffs_obj *obj = yaffs_alloc_raw_obj(dev);
+
+	if (!obj)
+		return obj;
+
+	dev->n_obj++;
+
+	/* Now sweeten it up... */
+
+	memset(obj, 0, sizeof(struct yaffs_obj));
+	obj->being_created = 1;
+
+	obj->my_dev = dev;
+	obj->hdr_chunk = 0;
+	obj->variant_type = YAFFS_OBJECT_TYPE_UNKNOWN;
+	INIT_LIST_HEAD(&(obj->hard_links));
+	INIT_LIST_HEAD(&(obj->hash_link));
+	INIT_LIST_HEAD(&obj->siblings);
+
+	/* Now make the directory sane */
+	if (dev->root_dir) {
+		obj->parent = dev->root_dir;
+		list_add(&(obj->siblings),
+			 &dev->root_dir->variant.dir_variant.children);
+	}
+
+	/* Add it to the lost and found directory.
+	 * NB Can't put root or lost-n-found in lost-n-found so
+	 * check if lost-n-found exists first
+	 */
+	if (dev->lost_n_found)
+		yaffs_add_obj_to_dir(dev->lost_n_found, obj);
+
+	obj->being_created = 0;
+
+	dev->checkpoint_blocks_required = 0;	/* force recalculation */
+
+	return obj;
+}
+
+static int yaffs_find_nice_bucket(struct yaffs_dev *dev)
+{
+	int i;
+	int l = 999;
+	int lowest = 999999;
+
+	/* Search for the shortest list or one that
+	 * isn't too long.
+	 */
+
+	for (i = 0; i < 10 && lowest > 4; i++) {
+		dev->bucket_finder++;
+		dev->bucket_finder %= YAFFS_NOBJECT_BUCKETS;
+		if (dev->obj_bucket[dev->bucket_finder].count < lowest) {
+			lowest = dev->obj_bucket[dev->bucket_finder].count;
+			l = dev->bucket_finder;
+		}
+	}
+
+	return l;
+}
+
+static int yaffs_new_obj_id(struct yaffs_dev *dev)
+{
+	int bucket = yaffs_find_nice_bucket(dev);
+	int found = 0;
+	struct list_head *i;
+	u32 n = (u32) bucket;
+
+	/* Now find an object value that has not already been taken
+	 * by scanning the list.
+	 */
+
+	while (!found) {
+		found = 1;
+		n += YAFFS_NOBJECT_BUCKETS;
+		if (1 || dev->obj_bucket[bucket].count > 0) {
+			list_for_each(i, &dev->obj_bucket[bucket].list) {
+				/* If there is already one in the list */
+				if (i && list_entry(i, struct yaffs_obj,
+						    hash_link)->obj_id == n) {
+					found = 0;
+				}
+			}
+		}
+	}
+	return n;
+}
+
+static void yaffs_hash_obj(struct yaffs_obj *in)
+{
+	int bucket = yaffs_hash_fn(in->obj_id);
+	struct yaffs_dev *dev = in->my_dev;
+
+	list_add(&in->hash_link, &dev->obj_bucket[bucket].list);
+	dev->obj_bucket[bucket].count++;
+}
+
+struct yaffs_obj *yaffs_find_by_number(struct yaffs_dev *dev, u32 number)
+{
+	int bucket = yaffs_hash_fn(number);
+	struct list_head *i;
+	struct yaffs_obj *in;
+
+	list_for_each(i, &dev->obj_bucket[bucket].list) {
+		/* Look if it is in the list */
+		in = list_entry(i, struct yaffs_obj, hash_link);
+		if (in->obj_id == number) {
+			/* Don't show if it is defered free */
+			if (in->defered_free)
+				return NULL;
+			return in;
+		}
+	}
+
+	return NULL;
+}
+
+struct yaffs_obj *yaffs_new_obj(struct yaffs_dev *dev, int number,
+				enum yaffs_obj_type type)
+{
+	struct yaffs_obj *the_obj = NULL;
+	struct yaffs_tnode *tn = NULL;
+
+	if (number < 0)
+		number = yaffs_new_obj_id(dev);
+
+	if (type == YAFFS_OBJECT_TYPE_FILE) {
+		tn = yaffs_get_tnode(dev);
+		if (!tn)
+			return NULL;
+	}
+
+	the_obj = yaffs_alloc_empty_obj(dev);
+	if (!the_obj) {
+		if (tn)
+			yaffs_free_tnode(dev, tn);
+		return NULL;
+	}
+
+	the_obj->fake = 0;
+	the_obj->rename_allowed = 1;
+	the_obj->unlink_allowed = 1;
+	the_obj->obj_id = number;
+	yaffs_hash_obj(the_obj);
+	the_obj->variant_type = type;
+	yaffs_load_current_time(the_obj, 1, 1);
+
+	switch (type) {
+	case YAFFS_OBJECT_TYPE_FILE:
+		the_obj->variant.file_variant.file_size = 0;
+		the_obj->variant.file_variant.scanned_size = 0;
+		the_obj->variant.file_variant.shrink_size =
+						yaffs_max_file_size(dev);
+		the_obj->variant.file_variant.top_level = 0;
+		the_obj->variant.file_variant.top = tn;
+		break;
+	case YAFFS_OBJECT_TYPE_DIRECTORY:
+		INIT_LIST_HEAD(&the_obj->variant.dir_variant.children);
+		INIT_LIST_HEAD(&the_obj->variant.dir_variant.dirty);
+		break;
+	case YAFFS_OBJECT_TYPE_SYMLINK:
+	case YAFFS_OBJECT_TYPE_HARDLINK:
+	case YAFFS_OBJECT_TYPE_SPECIAL:
+		/* No action required */
+		break;
+	case YAFFS_OBJECT_TYPE_UNKNOWN:
+		/* todo this should not happen */
+		break;
+	}
+	return the_obj;
+}
+
+static struct yaffs_obj *yaffs_create_fake_dir(struct yaffs_dev *dev,
+					       int number, u32 mode)
+{
+
+	struct yaffs_obj *obj =
+	    yaffs_new_obj(dev, number, YAFFS_OBJECT_TYPE_DIRECTORY);
+
+	if (!obj)
+		return NULL;
+
+	obj->fake = 1;	/* it is fake so it might not use NAND */
+	obj->rename_allowed = 0;
+	obj->unlink_allowed = 0;
+	obj->deleted = 0;
+	obj->unlinked = 0;
+	obj->yst_mode = mode;
+	obj->my_dev = dev;
+	obj->hdr_chunk = 0;	/* Not a valid chunk. */
+	return obj;
+
+}
+
+
+static void yaffs_init_tnodes_and_objs(struct yaffs_dev *dev)
+{
+	int i;
+
+	dev->n_obj = 0;
+	dev->n_tnodes = 0;
+	yaffs_init_raw_tnodes_and_objs(dev);
+
+	for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
+		INIT_LIST_HEAD(&dev->obj_bucket[i].list);
+		dev->obj_bucket[i].count = 0;
+	}
+}
+
+struct yaffs_obj *yaffs_find_or_create_by_number(struct yaffs_dev *dev,
+						 int number,
+						 enum yaffs_obj_type type)
+{
+	struct yaffs_obj *the_obj = NULL;
+
+	if (number > 0)
+		the_obj = yaffs_find_by_number(dev, number);
+
+	if (!the_obj)
+		the_obj = yaffs_new_obj(dev, number, type);
+
+	return the_obj;
+
+}
+
+YCHAR *yaffs_clone_str(const YCHAR *str)
+{
+	YCHAR *new_str = NULL;
+	int len;
+
+	if (!str)
+		str = _Y("");
+
+	len = yaffs_strnlen(str, YAFFS_MAX_ALIAS_LENGTH);
+	new_str = kmalloc((len + 1) * sizeof(YCHAR), GFP_NOFS);
+	if (new_str) {
+		yaffs_strncpy(new_str, str, len);
+		new_str[len] = 0;
+	}
+	return new_str;
+
+}
+/*
+ *yaffs_update_parent() handles fixing a directories mtime and ctime when a new
+ * link (ie. name) is created or deleted in the directory.
+ *
+ * ie.
+ *   create dir/a : update dir's mtime/ctime
+ *   rm dir/a:   update dir's mtime/ctime
+ *   modify dir/a: don't update dir's mtimme/ctime
+ *
+ * This can be handled immediately or defered. Defering helps reduce the number
+ * of updates when many files in a directory are changed within a brief period.
+ *
+ * If the directory updating is defered then yaffs_update_dirty_dirs must be
+ * called periodically.
+ */
+
+static void yaffs_update_parent(struct yaffs_obj *obj)
+{
+	struct yaffs_dev *dev;
+
+	if (!obj)
+		return;
+	dev = obj->my_dev;
+	obj->dirty = 1;
+	yaffs_load_current_time(obj, 0, 1);
+	if (dev->param.defered_dir_update) {
+		struct list_head *link = &obj->variant.dir_variant.dirty;
+
+		if (list_empty(link)) {
+			list_add(link, &dev->dirty_dirs);
+			yaffs_trace(YAFFS_TRACE_BACKGROUND,
+			  "Added object %d to dirty directories",
+			   obj->obj_id);
+		}
+
+	} else {
+		yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
+	}
+}
+
+void yaffs_update_dirty_dirs(struct yaffs_dev *dev)
+{
+	struct list_head *link;
+	struct yaffs_obj *obj;
+	struct yaffs_dir_var *d_s;
+	union yaffs_obj_var *o_v;
+
+	yaffs_trace(YAFFS_TRACE_BACKGROUND, "Update dirty directories");
+
+	while (!list_empty(&dev->dirty_dirs)) {
+		link = dev->dirty_dirs.next;
+		list_del_init(link);
+
+		d_s = list_entry(link, struct yaffs_dir_var, dirty);
+		o_v = list_entry(d_s, union yaffs_obj_var, dir_variant);
+		obj = list_entry(o_v, struct yaffs_obj, variant);
+
+		yaffs_trace(YAFFS_TRACE_BACKGROUND, "Update directory %d",
+			obj->obj_id);
+
+		if (obj->dirty)
+			yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
+	}
+}
+
+/*
+ * Mknod (create) a new object.
+ * equiv_obj only has meaning for a hard link;
+ * alias_str only has meaning for a symlink.
+ * rdev only has meaning for devices (a subset of special objects)
+ */
+
+static struct yaffs_obj *yaffs_create_obj(enum yaffs_obj_type type,
+					  struct yaffs_obj *parent,
+					  const YCHAR *name,
+					  u32 mode,
+					  u32 uid,
+					  u32 gid,
+					  struct yaffs_obj *equiv_obj,
+					  const YCHAR *alias_str, u32 rdev)
+{
+	struct yaffs_obj *in;
+	YCHAR *str = NULL;
+	struct yaffs_dev *dev = parent->my_dev;
+
+	/* Check if the entry exists.
+	 * If it does then fail the call since we don't want a dup. */
+	if (yaffs_find_by_name(parent, name))
+		return NULL;
+
+	if (type == YAFFS_OBJECT_TYPE_SYMLINK) {
+		str = yaffs_clone_str(alias_str);
+		if (!str)
+			return NULL;
+	}
+
+	in = yaffs_new_obj(dev, -1, type);
+
+	if (!in) {
+		kfree(str);
+		return NULL;
+	}
+
+	in->hdr_chunk = 0;
+	in->valid = 1;
+	in->variant_type = type;
+
+	in->yst_mode = mode;
+
+	yaffs_attribs_init(in, gid, uid, rdev);
+
+	in->n_data_chunks = 0;
+
+	yaffs_set_obj_name(in, name);
+	in->dirty = 1;
+
+	yaffs_add_obj_to_dir(parent, in);
+
+	in->my_dev = parent->my_dev;
+
+	switch (type) {
+	case YAFFS_OBJECT_TYPE_SYMLINK:
+		in->variant.symlink_variant.alias = str;
+		break;
+	case YAFFS_OBJECT_TYPE_HARDLINK:
+		in->variant.hardlink_variant.equiv_obj = equiv_obj;
+		in->variant.hardlink_variant.equiv_id = equiv_obj->obj_id;
+		list_add(&in->hard_links, &equiv_obj->hard_links);
+		break;
+	case YAFFS_OBJECT_TYPE_FILE:
+	case YAFFS_OBJECT_TYPE_DIRECTORY:
+	case YAFFS_OBJECT_TYPE_SPECIAL:
+	case YAFFS_OBJECT_TYPE_UNKNOWN:
+		/* do nothing */
+		break;
+	}
+
+	if (yaffs_update_oh(in, name, 0, 0, 0, NULL) < 0) {
+		/* Could not create the object header, fail */
+		yaffs_del_obj(in);
+		in = NULL;
+	}
+
+	if (in)
+		yaffs_update_parent(parent);
+
+	return in;
+}
+
+struct yaffs_obj *yaffs_create_file(struct yaffs_obj *parent,
+				    const YCHAR *name, u32 mode, u32 uid,
+				    u32 gid)
+{
+	return yaffs_create_obj(YAFFS_OBJECT_TYPE_FILE, parent, name, mode,
+				uid, gid, NULL, NULL, 0);
+}
+
+struct yaffs_obj *yaffs_create_dir(struct yaffs_obj *parent, const YCHAR *name,
+				   u32 mode, u32 uid, u32 gid)
+{
+	return yaffs_create_obj(YAFFS_OBJECT_TYPE_DIRECTORY, parent, name,
+				mode, uid, gid, NULL, NULL, 0);
+}
+
+struct yaffs_obj *yaffs_create_special(struct yaffs_obj *parent,
+				       const YCHAR *name, u32 mode, u32 uid,
+				       u32 gid, u32 rdev)
+{
+	return yaffs_create_obj(YAFFS_OBJECT_TYPE_SPECIAL, parent, name, mode,
+				uid, gid, NULL, NULL, rdev);
+}
+
+struct yaffs_obj *yaffs_create_symlink(struct yaffs_obj *parent,
+				       const YCHAR *name, u32 mode, u32 uid,
+				       u32 gid, const YCHAR *alias)
+{
+	return yaffs_create_obj(YAFFS_OBJECT_TYPE_SYMLINK, parent, name, mode,
+				uid, gid, NULL, alias, 0);
+}
+
+/* yaffs_link_obj returns the object id of the equivalent object.*/
+struct yaffs_obj *yaffs_link_obj(struct yaffs_obj *parent, const YCHAR * name,
+				 struct yaffs_obj *equiv_obj)
+{
+	/* Get the real object in case we were fed a hard link obj */
+	equiv_obj = yaffs_get_equivalent_obj(equiv_obj);
+
+	if (yaffs_create_obj(YAFFS_OBJECT_TYPE_HARDLINK,
+			parent, name, 0, 0, 0,
+			equiv_obj, NULL, 0))
+		return equiv_obj;
+
+	return NULL;
+
+}
+
+
+
+/*---------------------- Block Management and Page Allocation -------------*/
+
+static void yaffs_deinit_blocks(struct yaffs_dev *dev)
+{
+	if (dev->block_info_alt && dev->block_info)
+		vfree(dev->block_info);
+	else
+		kfree(dev->block_info);
+
+	dev->block_info_alt = 0;
+
+	dev->block_info = NULL;
+
+	if (dev->chunk_bits_alt && dev->chunk_bits)
+		vfree(dev->chunk_bits);
+	else
+		kfree(dev->chunk_bits);
+	dev->chunk_bits_alt = 0;
+	dev->chunk_bits = NULL;
+}
+
+static int yaffs_init_blocks(struct yaffs_dev *dev)
+{
+	int n_blocks = dev->internal_end_block - dev->internal_start_block + 1;
+
+	dev->block_info = NULL;
+	dev->chunk_bits = NULL;
+	dev->alloc_block = -1;	/* force it to get a new one */
+
+	/* If the first allocation strategy fails, thry the alternate one */
+	dev->block_info =
+		kmalloc(n_blocks * sizeof(struct yaffs_block_info), GFP_NOFS);
+	if (!dev->block_info) {
+		dev->block_info =
+		    vmalloc(n_blocks * sizeof(struct yaffs_block_info));
+		dev->block_info_alt = 1;
+	} else {
+		dev->block_info_alt = 0;
+	}
+
+	if (!dev->block_info)
+		goto alloc_error;
+
+	/* Set up dynamic blockinfo stuff. Round up bytes. */
+	dev->chunk_bit_stride = (dev->param.chunks_per_block + 7) / 8;
+	dev->chunk_bits =
+		kmalloc(dev->chunk_bit_stride * n_blocks, GFP_NOFS);
+	if (!dev->chunk_bits) {
+		dev->chunk_bits =
+		    vmalloc(dev->chunk_bit_stride * n_blocks);
+		dev->chunk_bits_alt = 1;
+	} else {
+		dev->chunk_bits_alt = 0;
+	}
+	if (!dev->chunk_bits)
+		goto alloc_error;
+
+
+	memset(dev->block_info, 0, n_blocks * sizeof(struct yaffs_block_info));
+	memset(dev->chunk_bits, 0, dev->chunk_bit_stride * n_blocks);
+	return YAFFS_OK;
+
+alloc_error:
+	yaffs_deinit_blocks(dev);
+	return YAFFS_FAIL;
+}
+
+
+void yaffs_block_became_dirty(struct yaffs_dev *dev, int block_no)
+{
+	struct yaffs_block_info *bi = yaffs_get_block_info(dev, block_no);
+	int erased_ok = 0;
+	int i;
+
+	/* If the block is still healthy erase it and mark as clean.
+	 * If the block has had a data failure, then retire it.
+	 */
+
+	yaffs_trace(YAFFS_TRACE_GC | YAFFS_TRACE_ERASE,
+		"yaffs_block_became_dirty block %d state %d %s",
+		block_no, bi->block_state,
+		(bi->needs_retiring) ? "needs retiring" : "");
+
+	yaffs2_clear_oldest_dirty_seq(dev, bi);
+
+	bi->block_state = YAFFS_BLOCK_STATE_DIRTY;
+
+	/* If this is the block being garbage collected then stop gc'ing */
+	if (block_no == dev->gc_block)
+		dev->gc_block = 0;
+
+	/* If this block is currently the best candidate for gc
+	 * then drop as a candidate */
+	if (block_no == dev->gc_dirtiest) {
+		dev->gc_dirtiest = 0;
+		dev->gc_pages_in_use = 0;
+	}
+
+	if (!bi->needs_retiring) {
+		yaffs2_checkpt_invalidate(dev);
+		erased_ok = yaffs_erase_block(dev, block_no);
+		if (!erased_ok) {
+			dev->n_erase_failures++;
+			yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
+			  "**>> Erasure failed %d", block_no);
+		}
+	}
+
+	/* Verify erasure if needed */
+	if (erased_ok &&
+	    ((yaffs_trace_mask & YAFFS_TRACE_ERASE) ||
+	     !yaffs_skip_verification(dev))) {
+		for (i = 0; i < dev->param.chunks_per_block; i++) {
+			if (!yaffs_check_chunk_erased(dev,
+				block_no * dev->param.chunks_per_block + i)) {
+				yaffs_trace(YAFFS_TRACE_ERROR,
+					">>Block %d erasure supposedly OK, but chunk %d not erased",
+					block_no, i);
+			}
+		}
+	}
+
+	if (!erased_ok) {
+		/* We lost a block of free space */
+		dev->n_free_chunks -= dev->param.chunks_per_block;
+		yaffs_retire_block(dev, block_no);
+		yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
+			"**>> Block %d retired", block_no);
+		return;
+	}
+
+	/* Clean it up... */
+	bi->block_state = YAFFS_BLOCK_STATE_EMPTY;
+	bi->seq_number = 0;
+	dev->n_erased_blocks++;
+	bi->pages_in_use = 0;
+	bi->soft_del_pages = 0;
+	bi->has_shrink_hdr = 0;
+	bi->skip_erased_check = 1;	/* Clean, so no need to check */
+	bi->gc_prioritise = 0;
+	bi->has_summary = 0;
+
+	yaffs_clear_chunk_bits(dev, block_no);
+
+	yaffs_trace(YAFFS_TRACE_ERASE, "Erased block %d", block_no);
+}
+
+static inline int yaffs_gc_process_chunk(struct yaffs_dev *dev,
+					struct yaffs_block_info *bi,
+					int old_chunk, u8 *buffer)
+{
+	int new_chunk;
+	int mark_flash = 1;
+	struct yaffs_ext_tags tags;
+	struct yaffs_obj *object;
+	int matching_chunk;
+	int ret_val = YAFFS_OK;
+
+	memset(&tags, 0, sizeof(tags));
+	yaffs_rd_chunk_tags_nand(dev, old_chunk,
+				 buffer, &tags);
+	object = yaffs_find_by_number(dev, tags.obj_id);
+
+	yaffs_trace(YAFFS_TRACE_GC_DETAIL,
+		"Collecting chunk in block %d, %d %d %d ",
+		dev->gc_chunk, tags.obj_id,
+		tags.chunk_id, tags.n_bytes);
+
+	if (object && !yaffs_skip_verification(dev)) {
+		if (tags.chunk_id == 0)
+			matching_chunk =
+			    object->hdr_chunk;
+		else if (object->soft_del)
+			/* Defeat the test */
+			matching_chunk = old_chunk;
+		else
+			matching_chunk =
+			    yaffs_find_chunk_in_file
+			    (object, tags.chunk_id,
+			     NULL);
+
+		if (old_chunk != matching_chunk)
+			yaffs_trace(YAFFS_TRACE_ERROR,
+				"gc: page in gc mismatch: %d %d %d %d",
+				old_chunk,
+				matching_chunk,
+				tags.obj_id,
+				tags.chunk_id);
+	}
+
+	if (!object) {
+		yaffs_trace(YAFFS_TRACE_ERROR,
+			"page %d in gc has no object: %d %d %d ",
+			old_chunk,
+			tags.obj_id, tags.chunk_id,
+			tags.n_bytes);
+	}
+
+	if (object &&
+	    object->deleted &&
+	    object->soft_del && tags.chunk_id != 0) {
+		/* Data chunk in a soft deleted file,
+		 * throw it away.
+		 * It's a soft deleted data chunk,
+		 * No need to copy this, just forget
+		 * about it and fix up the object.
+		 */
+
+		/* Free chunks already includes
+		 * softdeleted chunks, how ever this
+		 * chunk is going to soon be really
+		 * deleted which will increment free
+		 * chunks. We have to decrement free
+		 * chunks so this works out properly.
+		 */
+		dev->n_free_chunks--;
+		bi->soft_del_pages--;
+
+		object->n_data_chunks--;
+		if (object->n_data_chunks <= 0) {
+			/* remeber to clean up obj */
+			dev->gc_cleanup_list[dev->n_clean_ups] = tags.obj_id;
+			dev->n_clean_ups++;
+		}
+		mark_flash = 0;
+	} else if (object) {
+		/* It's either a data chunk in a live
+		 * file or an ObjectHeader, so we're
+		 * interested in it.
+		 * NB Need to keep the ObjectHeaders of
+		 * deleted files until the whole file
+		 * has been deleted off
+		 */
+		tags.serial_number++;
+		dev->n_gc_copies++;
+
+		if (tags.chunk_id == 0) {
+			/* It is an object Id,
+			 * We need to nuke the
+			 * shrinkheader flags since its
+			 * work is done.
+			 * Also need to clean up
+			 * shadowing.
+			 */
+			struct yaffs_obj_hdr *oh;
+			oh = (struct yaffs_obj_hdr *) buffer;
+
+			oh->is_shrink = 0;
+			tags.extra_is_shrink = 0;
+			oh->shadows_obj = 0;
+			oh->inband_shadowed_obj_id = 0;
+			tags.extra_shadows = 0;
+
+			/* Update file size */
+			if (object->variant_type == YAFFS_OBJECT_TYPE_FILE) {
+				yaffs_oh_size_load(oh,
+				    object->variant.file_variant.file_size);
+				tags.extra_file_size =
+				    object->variant.file_variant.file_size;
+			}
+
+			yaffs_verify_oh(object, oh, &tags, 1);
+			new_chunk =
+			    yaffs_write_new_chunk(dev, (u8 *) oh, &tags, 1);
+		} else {
+			new_chunk =
+			    yaffs_write_new_chunk(dev, buffer, &tags, 1);
+		}
+
+		if (new_chunk < 0) {
+			ret_val = YAFFS_FAIL;
+		} else {
+
+			/* Now fix up the Tnodes etc. */
+
+			if (tags.chunk_id == 0) {
+				/* It's a header */
+				object->hdr_chunk = new_chunk;
+				object->serial = tags.serial_number;
+			} else {
+				/* It's a data chunk */
+				yaffs_put_chunk_in_file(object, tags.chunk_id,
+							new_chunk, 0);
+			}
+		}
+	}
+	if (ret_val == YAFFS_OK)
+		yaffs_chunk_del(dev, old_chunk, mark_flash, __LINE__);
+	return ret_val;
+}
+
+static int yaffs_gc_block(struct yaffs_dev *dev, int block, int whole_block)
+{
+	int old_chunk;
+	int ret_val = YAFFS_OK;
+	int i;
+	int is_checkpt_block;
+	int max_copies;
+	int chunks_before = yaffs_get_erased_chunks(dev);
+	int chunks_after;
+	struct yaffs_block_info *bi = yaffs_get_block_info(dev, block);
+
+	is_checkpt_block = (bi->block_state == YAFFS_BLOCK_STATE_CHECKPOINT);
+
+	yaffs_trace(YAFFS_TRACE_TRACING,
+		"Collecting block %d, in use %d, shrink %d, whole_block %d",
+		block, bi->pages_in_use, bi->has_shrink_hdr,
+		whole_block);
+
+	/*yaffs_verify_free_chunks(dev); */
+
+	if (bi->block_state == YAFFS_BLOCK_STATE_FULL)
+		bi->block_state = YAFFS_BLOCK_STATE_COLLECTING;
+
+	bi->has_shrink_hdr = 0;	/* clear the flag so that the block can erase */
+
+	dev->gc_disable = 1;
+
+	yaffs_summary_gc(dev, block);
+
+	if (is_checkpt_block || !yaffs_still_some_chunks(dev, block)) {
+		yaffs_trace(YAFFS_TRACE_TRACING,
+			"Collecting block %d that has no chunks in use",
+			block);
+		yaffs_block_became_dirty(dev, block);
+	} else {
+
+		u8 *buffer = yaffs_get_temp_buffer(dev);
+
+		yaffs_verify_blk(dev, bi, block);
+
+		max_copies = (whole_block) ? dev->param.chunks_per_block : 5;
+		old_chunk = block * dev->param.chunks_per_block + dev->gc_chunk;
+
+		for (/* init already done */ ;
+		     ret_val == YAFFS_OK &&
+		     dev->gc_chunk < dev->param.chunks_per_block &&
+		     (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) &&
+		     max_copies > 0;
+		     dev->gc_chunk++, old_chunk++) {
+			if (yaffs_check_chunk_bit(dev, block, dev->gc_chunk)) {
+				/* Page is in use and might need to be copied */
+				max_copies--;
+				ret_val = yaffs_gc_process_chunk(dev, bi,
+							old_chunk, buffer);
+			}
+		}
+		yaffs_release_temp_buffer(dev, buffer);
+	}
+
+	yaffs_verify_collected_blk(dev, bi, block);
+
+	if (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
+		/*
+		 * The gc did not complete. Set block state back to FULL
+		 * because checkpointing does not restore gc.
+		 */
+		bi->block_state = YAFFS_BLOCK_STATE_FULL;
+	} else {
+		/* The gc completed. */
+		/* Do any required cleanups */
+		for (i = 0; i < dev->n_clean_ups; i++) {
+			/* Time to delete the file too */
+			struct yaffs_obj *object =
+			    yaffs_find_by_number(dev, dev->gc_cleanup_list[i]);
+			if (object) {
+				yaffs_free_tnode(dev,
+					  object->variant.file_variant.top);
+				object->variant.file_variant.top = NULL;
+				yaffs_trace(YAFFS_TRACE_GC,
+					"yaffs: About to finally delete object %d",
+					object->obj_id);
+				yaffs_generic_obj_del(object);
+				object->my_dev->n_deleted_files--;
+			}
+
+		}
+		chunks_after = yaffs_get_erased_chunks(dev);
+		if (chunks_before >= chunks_after)
+			yaffs_trace(YAFFS_TRACE_GC,
+				"gc did not increase free chunks before %d after %d",
+				chunks_before, chunks_after);
+		dev->gc_block = 0;
+		dev->gc_chunk = 0;
+		dev->n_clean_ups = 0;
+	}
+
+	dev->gc_disable = 0;
+
+	return ret_val;
+}
+
+/*
+ * find_gc_block() selects the dirtiest block (or close enough)
+ * for garbage collection.
+ */
+
+static unsigned yaffs_find_gc_block(struct yaffs_dev *dev,
+				    int aggressive, int background)
+{
+	int i;
+	int iterations;
+	unsigned selected = 0;
+	int prioritised = 0;
+	int prioritised_exist = 0;
+	struct yaffs_block_info *bi;
+	int threshold;
+
+	/* First let's see if we need to grab a prioritised block */
+	if (dev->has_pending_prioritised_gc && !aggressive) {
+		dev->gc_dirtiest = 0;
+		bi = dev->block_info;
+		for (i = dev->internal_start_block;
+		     i <= dev->internal_end_block && !selected; i++) {
+
+			if (bi->gc_prioritise) {
+				prioritised_exist = 1;
+				if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
+				    yaffs_block_ok_for_gc(dev, bi)) {
+					selected = i;
+					prioritised = 1;
+				}
+			}
+			bi++;
+		}
+
+		/*
+		 * If there is a prioritised block and none was selected then
+		 * this happened because there is at least one old dirty block
+		 * gumming up the works. Let's gc the oldest dirty block.
+		 */
+
+		if (prioritised_exist &&
+		    !selected && dev->oldest_dirty_block > 0)
+			selected = dev->oldest_dirty_block;
+
+		if (!prioritised_exist)	/* None found, so we can clear this */
+			dev->has_pending_prioritised_gc = 0;
+	}
+
+	/* If we're doing aggressive GC then we are happy to take a less-dirty
+	 * block, and search harder.
+	 * else (leasurely gc), then we only bother to do this if the
+	 * block has only a few pages in use.
+	 */
+
+	if (!selected) {
+		int pages_used;
+		int n_blocks =
+		    dev->internal_end_block - dev->internal_start_block + 1;
+		if (aggressive) {
+			threshold = dev->param.chunks_per_block;
+			iterations = n_blocks;
+		} else {
+			int max_threshold;
+
+			if (background)
+				max_threshold = dev->param.chunks_per_block / 2;
+			else
+				max_threshold = dev->param.chunks_per_block / 8;
+
+			if (max_threshold < YAFFS_GC_PASSIVE_THRESHOLD)
+				max_threshold = YAFFS_GC_PASSIVE_THRESHOLD;
+
+			threshold = background ? (dev->gc_not_done + 2) * 2 : 0;
+			if (threshold < YAFFS_GC_PASSIVE_THRESHOLD)
+				threshold = YAFFS_GC_PASSIVE_THRESHOLD;
+			if (threshold > max_threshold)
+				threshold = max_threshold;
+
+			iterations = n_blocks / 16 + 1;
+			if (iterations > 100)
+				iterations = 100;
+		}
+
+		for (i = 0;
+		     i < iterations &&
+		     (dev->gc_dirtiest < 1 ||
+		      dev->gc_pages_in_use > YAFFS_GC_GOOD_ENOUGH);
+		     i++) {
+			dev->gc_block_finder++;
+			if (dev->gc_block_finder < dev->internal_start_block ||
+			    dev->gc_block_finder > dev->internal_end_block)
+				dev->gc_block_finder =
+				    dev->internal_start_block;
+
+			bi = yaffs_get_block_info(dev, dev->gc_block_finder);
+
+			pages_used = bi->pages_in_use - bi->soft_del_pages;
+
+			if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
+			    pages_used < dev->param.chunks_per_block &&
+			    (dev->gc_dirtiest < 1 ||
+			     pages_used < dev->gc_pages_in_use) &&
+			    yaffs_block_ok_for_gc(dev, bi)) {
+				dev->gc_dirtiest = dev->gc_block_finder;
+				dev->gc_pages_in_use = pages_used;
+			}
+		}
+
+		if (dev->gc_dirtiest > 0 && dev->gc_pages_in_use <= threshold)
+			selected = dev->gc_dirtiest;
+	}
+
+	/*
+	 * If nothing has been selected for a while, try the oldest dirty
+	 * because that's gumming up the works.
+	 */
+
+	if (!selected && dev->param.is_yaffs2 &&
+	    dev->gc_not_done >= (background ? 10 : 20)) {
+		yaffs2_find_oldest_dirty_seq(dev);
+		if (dev->oldest_dirty_block > 0) {
+			selected = dev->oldest_dirty_block;
+			dev->gc_dirtiest = selected;
+			dev->oldest_dirty_gc_count++;
+			bi = yaffs_get_block_info(dev, selected);
+			dev->gc_pages_in_use =
+			    bi->pages_in_use - bi->soft_del_pages;
+		} else {
+			dev->gc_not_done = 0;
+		}
+	}
+
+	if (selected) {
+		yaffs_trace(YAFFS_TRACE_GC,
+			"GC Selected block %d with %d free, prioritised:%d",
+			selected,
+			dev->param.chunks_per_block - dev->gc_pages_in_use,
+			prioritised);
+
+		dev->n_gc_blocks++;
+		if (background)
+			dev->bg_gcs++;
+
+		dev->gc_dirtiest = 0;
+		dev->gc_pages_in_use = 0;
+		dev->gc_not_done = 0;
+		if (dev->refresh_skip > 0)
+			dev->refresh_skip--;
+	} else {
+		dev->gc_not_done++;
+		yaffs_trace(YAFFS_TRACE_GC,
+			"GC none: finder %d skip %d threshold %d dirtiest %d using %d oldest %d%s",
+			dev->gc_block_finder, dev->gc_not_done, threshold,
+			dev->gc_dirtiest, dev->gc_pages_in_use,
+			dev->oldest_dirty_block, background ? " bg" : "");
+	}
+
+	return selected;
+}
+
+/* New garbage collector
+ * If we're very low on erased blocks then we do aggressive garbage collection
+ * otherwise we do "leasurely" garbage collection.
+ * Aggressive gc looks further (whole array) and will accept less dirty blocks.
+ * Passive gc only inspects smaller areas and only accepts more dirty blocks.
+ *
+ * The idea is to help clear out space in a more spread-out manner.
+ * Dunno if it really does anything useful.
+ */
+static int yaffs_check_gc(struct yaffs_dev *dev, int background)
+{
+	int aggressive = 0;
+	int gc_ok = YAFFS_OK;
+	int max_tries = 0;
+	int min_erased;
+	int erased_chunks;
+	int checkpt_block_adjust;
+
+	if (dev->param.gc_control && (dev->param.gc_control(dev) & 1) == 0)
+		return YAFFS_OK;
+
+	if (dev->gc_disable)
+		/* Bail out so we don't get recursive gc */
+		return YAFFS_OK;
+
+	/* This loop should pass the first time.
+	 * Only loops here if the collection does not increase space.
+	 */
+
+	do {
+		max_tries++;
+
+		checkpt_block_adjust = yaffs_calc_checkpt_blocks_required(dev);
+
+		min_erased =
+		    dev->param.n_reserved_blocks + checkpt_block_adjust + 1;
+		erased_chunks =
+		    dev->n_erased_blocks * dev->param.chunks_per_block;
+
+		/* If we need a block soon then do aggressive gc. */
+		if (dev->n_erased_blocks < min_erased)
+			aggressive = 1;
+		else {
+			if (!background
+			    && erased_chunks > (dev->n_free_chunks / 4))
+				break;
+
+			if (dev->gc_skip > 20)
+				dev->gc_skip = 20;
+			if (erased_chunks < dev->n_free_chunks / 2 ||
+			    dev->gc_skip < 1 || background)
+				aggressive = 0;
+			else {
+				dev->gc_skip--;
+				break;
+			}
+		}
+
+		dev->gc_skip = 5;
+
+		/* If we don't already have a block being gc'd then see if we
+		 * should start another */
+
+		if (dev->gc_block < 1 && !aggressive) {
+			dev->gc_block = yaffs2_find_refresh_block(dev);
+			dev->gc_chunk = 0;
+			dev->n_clean_ups = 0;
+		}
+		if (dev->gc_block < 1) {
+			dev->gc_block =
+			    yaffs_find_gc_block(dev, aggressive, background);
+			dev->gc_chunk = 0;
+			dev->n_clean_ups = 0;
+		}
+
+		if (dev->gc_block > 0) {
+			dev->all_gcs++;
+			if (!aggressive)
+				dev->passive_gc_count++;
+
+			yaffs_trace(YAFFS_TRACE_GC,
+				"yaffs: GC n_erased_blocks %d aggressive %d",
+				dev->n_erased_blocks, aggressive);
+
+			gc_ok = yaffs_gc_block(dev, dev->gc_block, aggressive);
+		}
+
+		if (dev->n_erased_blocks < (dev->param.n_reserved_blocks) &&
+		    dev->gc_block > 0) {
+			yaffs_trace(YAFFS_TRACE_GC,
+				"yaffs: GC !!!no reclaim!!! n_erased_blocks %d after try %d block %d",
+				dev->n_erased_blocks, max_tries,
+				dev->gc_block);
+		}
+	} while ((dev->n_erased_blocks < dev->param.n_reserved_blocks) &&
+		 (dev->gc_block > 0) && (max_tries < 2));
+
+	return aggressive ? gc_ok : YAFFS_OK;
+}
+
+/*
+ * yaffs_bg_gc()
+ * Garbage collects. Intended to be called from a background thread.
+ * Returns non-zero if at least half the free chunks are erased.
+ */
+int yaffs_bg_gc(struct yaffs_dev *dev, unsigned urgency)
+{
+	int erased_chunks = dev->n_erased_blocks * dev->param.chunks_per_block;
+
+	yaffs_trace(YAFFS_TRACE_BACKGROUND, "Background gc %u", urgency);
+
+	yaffs_check_gc(dev, 1);
+	return erased_chunks > dev->n_free_chunks / 2;
+}
+
+/*-------------------- Data file manipulation -----------------*/
+
+static int yaffs_rd_data_obj(struct yaffs_obj *in, int inode_chunk, u8 * buffer)
+{
+	int nand_chunk = yaffs_find_chunk_in_file(in, inode_chunk, NULL);
+
+	if (nand_chunk >= 0)
+		return yaffs_rd_chunk_tags_nand(in->my_dev, nand_chunk,
+						buffer, NULL);
+	else {
+		yaffs_trace(YAFFS_TRACE_NANDACCESS,
+			"Chunk %d not found zero instead",
+			nand_chunk);
+		/* get sane (zero) data if you read a hole */
+		memset(buffer, 0, in->my_dev->data_bytes_per_chunk);
+		return 0;
+	}
+
+}
+
+void yaffs_chunk_del(struct yaffs_dev *dev, int chunk_id, int mark_flash,
+		     int lyn)
+{
+	int block;
+	int page;
+	struct yaffs_ext_tags tags;
+	struct yaffs_block_info *bi;
+
+	if (chunk_id <= 0)
+		return;
+
+	dev->n_deletions++;
+	block = chunk_id / dev->param.chunks_per_block;
+	page = chunk_id % dev->param.chunks_per_block;
+
+	if (!yaffs_check_chunk_bit(dev, block, page))
+		yaffs_trace(YAFFS_TRACE_VERIFY,
+			"Deleting invalid chunk %d", chunk_id);
+
+	bi = yaffs_get_block_info(dev, block);
+
+	yaffs2_update_oldest_dirty_seq(dev, block, bi);
+
+	yaffs_trace(YAFFS_TRACE_DELETION,
+		"line %d delete of chunk %d",
+		lyn, chunk_id);
+
+	if (!dev->param.is_yaffs2 && mark_flash &&
+	    bi->block_state != YAFFS_BLOCK_STATE_COLLECTING) {
+
+		memset(&tags, 0, sizeof(tags));
+		tags.is_deleted = 1;
+		yaffs_wr_chunk_tags_nand(dev, chunk_id, NULL, &tags);
+		yaffs_handle_chunk_update(dev, chunk_id, &tags);
+	} else {
+		dev->n_unmarked_deletions++;
+	}
+
+	/* Pull out of the management area.
+	 * If the whole block became dirty, this will kick off an erasure.
+	 */
+	if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING ||
+	    bi->block_state == YAFFS_BLOCK_STATE_FULL ||
+	    bi->block_state == YAFFS_BLOCK_STATE_NEEDS_SCAN ||
+	    bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
+		dev->n_free_chunks++;
+		yaffs_clear_chunk_bit(dev, block, page);
+		bi->pages_in_use--;
+
+		if (bi->pages_in_use == 0 &&
+		    !bi->has_shrink_hdr &&
+		    bi->block_state != YAFFS_BLOCK_STATE_ALLOCATING &&
+		    bi->block_state != YAFFS_BLOCK_STATE_NEEDS_SCAN) {
+			yaffs_block_became_dirty(dev, block);
+		}
+	}
+}
+
+static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk,
+			     const u8 *buffer, int n_bytes, int use_reserve)
+{
+	/* Find old chunk Need to do this to get serial number
+	 * Write new one and patch into tree.
+	 * Invalidate old tags.
+	 */
+
+	int prev_chunk_id;
+	struct yaffs_ext_tags prev_tags;
+	int new_chunk_id;
+	struct yaffs_ext_tags new_tags;
+	struct yaffs_dev *dev = in->my_dev;
+
+	yaffs_check_gc(dev, 0);
+
+	/* Get the previous chunk at this location in the file if it exists.
+	 * If it does not exist then put a zero into the tree. This creates
+	 * the tnode now, rather than later when it is harder to clean up.
+	 */
+	prev_chunk_id = yaffs_find_chunk_in_file(in, inode_chunk, &prev_tags);
+	if (prev_chunk_id < 1 &&
+	    !yaffs_put_chunk_in_file(in, inode_chunk, 0, 0))
+		return 0;
+
+	/* Set up new tags */
+	memset(&new_tags, 0, sizeof(new_tags));
+
+	new_tags.chunk_id = inode_chunk;
+	new_tags.obj_id = in->obj_id;
+	new_tags.serial_number =
+	    (prev_chunk_id > 0) ? prev_tags.serial_number + 1 : 1;
+	new_tags.n_bytes = n_bytes;
+
+	if (n_bytes < 1 || n_bytes > dev->param.total_bytes_per_chunk) {
+		yaffs_trace(YAFFS_TRACE_ERROR,
+		  "Writing %d bytes to chunk!!!!!!!!!",
+		   n_bytes);
+		BUG();
+	}
+
+	new_chunk_id =
+	    yaffs_write_new_chunk(dev, buffer, &new_tags, use_reserve);
+
+	if (new_chunk_id > 0) {
+		yaffs_put_chunk_in_file(in, inode_chunk, new_chunk_id, 0);
+
+		if (prev_chunk_id > 0)
+			yaffs_chunk_del(dev, prev_chunk_id, 1, __LINE__);
+
+		yaffs_verify_file_sane(in);
+	}
+	return new_chunk_id;
+
+}
+
+
+
+static int yaffs_do_xattrib_mod(struct yaffs_obj *obj, int set,
+				const YCHAR *name, const void *value, int size,
+				int flags)
+{
+	struct yaffs_xattr_mod xmod;
+	int result;
+
+	xmod.set = set;
+	xmod.name = name;
+	xmod.data = value;
+	xmod.size = size;
+	xmod.flags = flags;
+	xmod.result = -ENOSPC;
+
+	result = yaffs_update_oh(obj, NULL, 0, 0, 0, &xmod);
+
+	if (result > 0)
+		return xmod.result;
+	else
+		return -ENOSPC;
+}
+
+static int yaffs_apply_xattrib_mod(struct yaffs_obj *obj, char *buffer,
+				   struct yaffs_xattr_mod *xmod)
+{
+	int retval = 0;
+	int x_offs = sizeof(struct yaffs_obj_hdr);
+	struct yaffs_dev *dev = obj->my_dev;
+	int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
+	char *x_buffer = buffer + x_offs;
+
+	if (xmod->set)
+		retval =
+		    nval_set(x_buffer, x_size, xmod->name, xmod->data,
+			     xmod->size, xmod->flags);
+	else
+		retval = nval_del(x_buffer, x_size, xmod->name);
+
+	obj->has_xattr = nval_hasvalues(x_buffer, x_size);
+	obj->xattr_known = 1;
+	xmod->result = retval;
+
+	return retval;
+}
+
+static int yaffs_do_xattrib_fetch(struct yaffs_obj *obj, const YCHAR *name,
+				  void *value, int size)
+{
+	char *buffer = NULL;
+	int result;
+	struct yaffs_ext_tags tags;
+	struct yaffs_dev *dev = obj->my_dev;
+	int x_offs = sizeof(struct yaffs_obj_hdr);
+	int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
+	char *x_buffer;
+	int retval = 0;
+
+	if (obj->hdr_chunk < 1)
+		return -ENODATA;
+
+	/* If we know that the object has no xattribs then don't do all the
+	 * reading and parsing.
+	 */
+	if (obj->xattr_known && !obj->has_xattr) {
+		if (name)
+			return -ENODATA;
+		else
+			return 0;
+	}
+
+	buffer = (char *)yaffs_get_temp_buffer(dev);
+	if (!buffer)
+		return -ENOMEM;
+
+	result =
+	    yaffs_rd_chunk_tags_nand(dev, obj->hdr_chunk, (u8 *) buffer, &tags);
+
+	if (result != YAFFS_OK)
+		retval = -ENOENT;
+	else {
+		x_buffer = buffer + x_offs;
+
+		if (!obj->xattr_known) {
+			obj->has_xattr = nval_hasvalues(x_buffer, x_size);
+			obj->xattr_known = 1;
+		}
+
+		if (name)
+			retval = nval_get(x_buffer, x_size, name, value, size);
+		else
+			retval = nval_list(x_buffer, x_size, value, size);
+	}
+	yaffs_release_temp_buffer(dev, (u8 *) buffer);
+	return retval;
+}
+
+int yaffs_set_xattrib(struct yaffs_obj *obj, const YCHAR * name,
+		      const void *value, int size, int flags)
+{
+	return yaffs_do_xattrib_mod(obj, 1, name, value, size, flags);
+}
+
+int yaffs_remove_xattrib(struct yaffs_obj *obj, const YCHAR * name)
+{
+	return yaffs_do_xattrib_mod(obj, 0, name, NULL, 0, 0);
+}
+
+int yaffs_get_xattrib(struct yaffs_obj *obj, const YCHAR * name, void *value,
+		      int size)
+{
+	return yaffs_do_xattrib_fetch(obj, name, value, size);
+}
+
+int yaffs_list_xattrib(struct yaffs_obj *obj, char *buffer, int size)
+{
+	return yaffs_do_xattrib_fetch(obj, NULL, buffer, size);
+}
+
+static void yaffs_check_obj_details_loaded(struct yaffs_obj *in)
+{
+	u8 *buf;
+	struct yaffs_obj_hdr *oh;
+	struct yaffs_dev *dev;
+	struct yaffs_ext_tags tags;
+
+	if (!in || !in->lazy_loaded || in->hdr_chunk < 1)
+		return;
+
+	dev = in->my_dev;
+	in->lazy_loaded = 0;
+	buf = yaffs_get_temp_buffer(dev);
+
+	yaffs_rd_chunk_tags_nand(dev, in->hdr_chunk, buf, &tags);
+	oh = (struct yaffs_obj_hdr *)buf;
+
+	in->yst_mode = oh->yst_mode;
+	yaffs_load_attribs(in, oh);
+	yaffs_set_obj_name_from_oh(in, oh);
+
+	if (in->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
+		in->variant.symlink_variant.alias =
+		    yaffs_clone_str(oh->alias);
+	}
+	yaffs_release_temp_buffer(dev, buf);
+}
+
+static void yaffs_load_name_from_oh(struct yaffs_dev *dev, YCHAR *name,
+				    const YCHAR *oh_name, int buff_size)
+{
+#ifdef CONFIG_YAFFS_AUTO_UNICODE
+	if (dev->param.auto_unicode) {
+		if (*oh_name) {
+			/* It is an ASCII name, do an ASCII to
+			 * unicode conversion */
+			const char *ascii_oh_name = (const char *)oh_name;
+			int n = buff_size - 1;
+			while (n > 0 && *ascii_oh_name) {
+				*name = *ascii_oh_name;
+				name++;
+				ascii_oh_name++;
+				n--;
+			}
+		} else {
+			yaffs_strncpy(name, oh_name + 1, buff_size - 1);
+		}
+	} else {
+#else
+	dev = dev;
+	{
+#endif
+		yaffs_strncpy(name, oh_name, buff_size - 1);
+	}
+}
+
+static void yaffs_load_oh_from_name(struct yaffs_dev *dev, YCHAR *oh_name,
+				    const YCHAR *name)
+{
+#ifdef CONFIG_YAFFS_AUTO_UNICODE
+
+	int is_ascii;
+	YCHAR *w;
+
+	if (dev->param.auto_unicode) {
+
+		is_ascii = 1;
+		w = name;
+
+		/* Figure out if the name will fit in ascii character set */
+		while (is_ascii && *w) {
+			if ((*w) & 0xff00)
+				is_ascii = 0;
+			w++;
+		}
+
+		if (is_ascii) {
+			/* It is an ASCII name, so convert unicode to ascii */
+			char *ascii_oh_name = (char *)oh_name;
+			int n = YAFFS_MAX_NAME_LENGTH - 1;
+			while (n > 0 && *name) {
+				*ascii_oh_name = *name;
+				name++;
+				ascii_oh_name++;
+				n--;
+			}
+		} else {
+			/* Unicode name, so save starting at the second YCHAR */
+			*oh_name = 0;
+			yaffs_strncpy(oh_name + 1, name, YAFFS_MAX_NAME_LENGTH - 2);
+		}
+	} else {
+#else
+	dev = dev;
+	{
+#endif
+		yaffs_strncpy(oh_name, name, YAFFS_MAX_NAME_LENGTH - 1);
+	}
+}
+
+/* UpdateObjectHeader updates the header on NAND for an object.
+ * If name is not NULL, then that new name is used.
+ */
+int yaffs_update_oh(struct yaffs_obj *in, const YCHAR *name, int force,
+		    int is_shrink, int shadows, struct yaffs_xattr_mod *xmod)
+{
+
+	struct yaffs_block_info *bi;
+	struct yaffs_dev *dev = in->my_dev;
+	int prev_chunk_id;
+	int ret_val = 0;
+	int new_chunk_id;
+	struct yaffs_ext_tags new_tags;
+	struct yaffs_ext_tags old_tags;
+	const YCHAR *alias = NULL;
+	u8 *buffer = NULL;
+	YCHAR old_name[YAFFS_MAX_NAME_LENGTH + 1];
+	struct yaffs_obj_hdr *oh = NULL;
+	loff_t file_size = 0;
+
+	yaffs_strcpy(old_name, _Y("silly old name"));
+
+	if (in->fake && in != dev->root_dir && !force && !xmod)
+		return ret_val;
+
+	yaffs_check_gc(dev, 0);
+	yaffs_check_obj_details_loaded(in);
+
+	buffer = yaffs_get_temp_buffer(in->my_dev);
+	oh = (struct yaffs_obj_hdr *)buffer;
+
+	prev_chunk_id = in->hdr_chunk;
+
+	if (prev_chunk_id > 0) {
+		yaffs_rd_chunk_tags_nand(dev, prev_chunk_id,
+					  buffer, &old_tags);
+
+		yaffs_verify_oh(in, oh, &old_tags, 0);
+		memcpy(old_name, oh->name, sizeof(oh->name));
+		memset(buffer, 0xff, sizeof(struct yaffs_obj_hdr));
+	} else {
+		memset(buffer, 0xff, dev->data_bytes_per_chunk);
+	}
+
+	oh->type = in->variant_type;
+	oh->yst_mode = in->yst_mode;
+	oh->shadows_obj = oh->inband_shadowed_obj_id = shadows;
+
+	yaffs_load_attribs_oh(oh, in);
+
+	if (in->parent)
+		oh->parent_obj_id = in->parent->obj_id;
+	else
+		oh->parent_obj_id = 0;
+
+	if (name && *name) {
+		memset(oh->name, 0, sizeof(oh->name));
+		yaffs_load_oh_from_name(dev, oh->name, name);
+	} else if (prev_chunk_id > 0) {
+		memcpy(oh->name, old_name, sizeof(oh->name));
+	} else {
+		memset(oh->name, 0, sizeof(oh->name));
+	}
+
+	oh->is_shrink = is_shrink;
+
+	switch (in->variant_type) {
+	case YAFFS_OBJECT_TYPE_UNKNOWN:
+		/* Should not happen */
+		break;
+	case YAFFS_OBJECT_TYPE_FILE:
+		if (oh->parent_obj_id != YAFFS_OBJECTID_DELETED &&
+		    oh->parent_obj_id != YAFFS_OBJECTID_UNLINKED)
+			file_size = in->variant.file_variant.file_size;
+		yaffs_oh_size_load(oh, file_size);
+		break;
+	case YAFFS_OBJECT_TYPE_HARDLINK:
+		oh->equiv_id = in->variant.hardlink_variant.equiv_id;
+		break;
+	case YAFFS_OBJECT_TYPE_SPECIAL:
+		/* Do nothing */
+		break;
+	case YAFFS_OBJECT_TYPE_DIRECTORY:
+		/* Do nothing */
+		break;
+	case YAFFS_OBJECT_TYPE_SYMLINK:
+		alias = in->variant.symlink_variant.alias;
+		if (!alias)
+			alias = _Y("no alias");
+		yaffs_strncpy(oh->alias, alias, YAFFS_MAX_ALIAS_LENGTH);
+		oh->alias[YAFFS_MAX_ALIAS_LENGTH] = 0;
+		break;
+	}
+
+	/* process any xattrib modifications */
+	if (xmod)
+		yaffs_apply_xattrib_mod(in, (char *)buffer, xmod);
+
+	/* Tags */
+	memset(&new_tags, 0, sizeof(new_tags));
+	in->serial++;
+	new_tags.chunk_id = 0;
+	new_tags.obj_id = in->obj_id;
+	new_tags.serial_number = in->serial;
+
+	/* Add extra info for file header */
+	new_tags.extra_available = 1;
+	new_tags.extra_parent_id = oh->parent_obj_id;
+	new_tags.extra_file_size = file_size;
+	new_tags.extra_is_shrink = oh->is_shrink;
+	new_tags.extra_equiv_id = oh->equiv_id;
+	new_tags.extra_shadows = (oh->shadows_obj > 0) ? 1 : 0;
+	new_tags.extra_obj_type = in->variant_type;
+	yaffs_verify_oh(in, oh, &new_tags, 1);
+
+	/* Create new chunk in NAND */
+	new_chunk_id =
+	    yaffs_write_new_chunk(dev, buffer, &new_tags,
+				  (prev_chunk_id > 0) ? 1 : 0);
+
+	if (buffer)
+		yaffs_release_temp_buffer(dev, buffer);
+
+	if (new_chunk_id < 0)
+		return new_chunk_id;
+
+	in->hdr_chunk = new_chunk_id;
+
+	if (prev_chunk_id > 0)
+		yaffs_chunk_del(dev, prev_chunk_id, 1, __LINE__);
+
+	if (!yaffs_obj_cache_dirty(in))
+		in->dirty = 0;
+
+	/* If this was a shrink, then mark the block
+	 * that the chunk lives on */
+	if (is_shrink) {
+		bi = yaffs_get_block_info(in->my_dev,
+					  new_chunk_id /
+					  in->my_dev->param.chunks_per_block);
+		bi->has_shrink_hdr = 1;
+	}
+
+
+	return new_chunk_id;
+}
+
+/*--------------------- File read/write ------------------------
+ * Read and write have very similar structures.
+ * In general the read/write has three parts to it
+ * An incomplete chunk to start with (if the read/write is not chunk-aligned)
+ * Some complete chunks
+ * An incomplete chunk to end off with
+ *
+ * Curve-balls: the first chunk might also be the last chunk.
+ */
+
+int yaffs_file_rd(struct yaffs_obj *in, u8 * buffer, loff_t offset, int n_bytes)
+{
+	int chunk;
+	u32 start;
+	int n_copy;
+	int n = n_bytes;
+	int n_done = 0;
+	struct yaffs_cache *cache;
+	struct yaffs_dev *dev;
+
+	dev = in->my_dev;
+
+	while (n > 0) {
+		yaffs_addr_to_chunk(dev, offset, &chunk, &start);
+		chunk++;
+
+		/* OK now check for the curveball where the start and end are in
+		 * the same chunk.
+		 */
+		if ((start + n) < dev->data_bytes_per_chunk)
+			n_copy = n;
+		else
+			n_copy = dev->data_bytes_per_chunk - start;
+
+		cache = yaffs_find_chunk_cache(in, chunk);
+
+		/* If the chunk is already in the cache or it is less than
+		 * a whole chunk or we're using inband tags then use the cache
+		 * (if there is caching) else bypass the cache.
+		 */
+		if (cache || n_copy != dev->data_bytes_per_chunk ||
+		    dev->param.inband_tags) {
+			if (dev->param.n_caches > 0) {
+
+				/* If we can't find the data in the cache,
+				 * then load it up. */
+
+				if (!cache) {
+					cache =
+					    yaffs_grab_chunk_cache(in->my_dev);
+					cache->object = in;
+					cache->chunk_id = chunk;
+					cache->dirty = 0;
+					cache->locked = 0;
+					yaffs_rd_data_obj(in, chunk,
+							  cache->data);
+					cache->n_bytes = 0;
+				}
+
+				yaffs_use_cache(dev, cache, 0);
+
+				cache->locked = 1;
+
+				memcpy(buffer, &cache->data[start], n_copy);
+
+				cache->locked = 0;
+			} else {
+				/* Read into the local buffer then copy.. */
+
+				u8 *local_buffer =
+				    yaffs_get_temp_buffer(dev);
+				yaffs_rd_data_obj(in, chunk, local_buffer);
+
+				memcpy(buffer, &local_buffer[start], n_copy);
+
+				yaffs_release_temp_buffer(dev, local_buffer);
+			}
+		} else {
+			/* A full chunk. Read directly into the buffer. */
+			yaffs_rd_data_obj(in, chunk, buffer);
+		}
+		n -= n_copy;
+		offset += n_copy;
+		buffer += n_copy;
+		n_done += n_copy;
+	}
+	return n_done;
+}
+
+int yaffs_do_file_wr(struct yaffs_obj *in, const u8 *buffer, loff_t offset,
+		     int n_bytes, int write_through)
+{
+
+	int chunk;
+	u32 start;
+	int n_copy;
+	int n = n_bytes;
+	int n_done = 0;
+	int n_writeback;
+	loff_t start_write = offset;
+	int chunk_written = 0;
+	u32 n_bytes_read;
+	loff_t chunk_start;
+	struct yaffs_dev *dev;
+
+	dev = in->my_dev;
+
+	while (n > 0 && chunk_written >= 0) {
+		yaffs_addr_to_chunk(dev, offset, &chunk, &start);
+
+		if (((loff_t)chunk) *
+		    dev->data_bytes_per_chunk + start != offset ||
+		    start >= dev->data_bytes_per_chunk) {
+			yaffs_trace(YAFFS_TRACE_ERROR,
+				"AddrToChunk of offset %lld gives chunk %d start %d",
+				offset, chunk, start);
+		}
+		chunk++;	/* File pos to chunk in file offset */
+
+		/* OK now check for the curveball where the start and end are in
+		 * the same chunk.
+		 */
+
+		if ((start + n) < dev->data_bytes_per_chunk) {
+			n_copy = n;
+
+			/* Now calculate how many bytes to write back....
+			 * If we're overwriting and not writing to then end of
+			 * file then we need to write back as much as was there
+			 * before.
+			 */
+
+			chunk_start = (((loff_t)(chunk - 1)) *
+					dev->data_bytes_per_chunk);
+
+			if (chunk_start > in->variant.file_variant.file_size)
+				n_bytes_read = 0;	/* Past end of file */
+			else
+				n_bytes_read =
+				    in->variant.file_variant.file_size -
+				    chunk_start;
+
+			if (n_bytes_read > dev->data_bytes_per_chunk)
+				n_bytes_read = dev->data_bytes_per_chunk;
+
+			n_writeback =
+			    (n_bytes_read >
+			     (start + n)) ? n_bytes_read : (start + n);
+
+			if (n_writeback < 0 ||
+			    n_writeback > dev->data_bytes_per_chunk)
+				BUG();
+
+		} else {
+			n_copy = dev->data_bytes_per_chunk - start;
+			n_writeback = dev->data_bytes_per_chunk;
+		}
+
+		if (n_copy != dev->data_bytes_per_chunk ||
+		    dev->param.inband_tags) {
+			/* An incomplete start or end chunk (or maybe both
+			 * start and end chunk), or we're using inband tags,
+			 * so we want to use the cache buffers.
+			 */
+			if (dev->param.n_caches > 0) {
+				struct yaffs_cache *cache;
+
+				/* If we can't find the data in the cache, then
+				 * load the cache */
+				cache = yaffs_find_chunk_cache(in, chunk);
+
+				if (!cache &&
+				    yaffs_check_alloc_available(dev, 1)) {
+					cache = yaffs_grab_chunk_cache(dev);
+					cache->object = in;
+					cache->chunk_id = chunk;
+					cache->dirty = 0;
+					cache->locked = 0;
+					yaffs_rd_data_obj(in, chunk,
+							  cache->data);
+				} else if (cache &&
+					   !cache->dirty &&
+					   !yaffs_check_alloc_available(dev,
+									1)) {
+					/* Drop the cache if it was a read cache
+					 * item and no space check has been made
+					 * for it.
+					 */
+					cache = NULL;
+				}
+
+				if (cache) {
+					yaffs_use_cache(dev, cache, 1);
+					cache->locked = 1;
+
+					memcpy(&cache->data[start], buffer,
+					       n_copy);
+
+					cache->locked = 0;
+					cache->n_bytes = n_writeback;
+
+					if (write_through) {
+						chunk_written =
+						    yaffs_wr_data_obj
+						    (cache->object,
+						     cache->chunk_id,
+						     cache->data,
+						     cache->n_bytes, 1);
+						cache->dirty = 0;
+					}
+				} else {
+					chunk_written = -1;	/* fail write */
+				}
+			} else {
+				/* An incomplete start or end chunk (or maybe
+				 * both start and end chunk). Read into the
+				 * local buffer then copy over and write back.
+				 */
+
+				u8 *local_buffer = yaffs_get_temp_buffer(dev);
+
+				yaffs_rd_data_obj(in, chunk, local_buffer);
+				memcpy(&local_buffer[start], buffer, n_copy);
+
+				chunk_written =
+				    yaffs_wr_data_obj(in, chunk,
+						      local_buffer,
+						      n_writeback, 0);
+
+				yaffs_release_temp_buffer(dev, local_buffer);
+			}
+		} else {
+			/* A full chunk. Write directly from the buffer. */
+
+			chunk_written =
+			    yaffs_wr_data_obj(in, chunk, buffer,
+					      dev->data_bytes_per_chunk, 0);
+
+			/* Since we've overwritten the cached data,
+			 * we better invalidate it. */
+			yaffs_invalidate_chunk_cache(in, chunk);
+		}
+
+		if (chunk_written >= 0) {
+			n -= n_copy;
+			offset += n_copy;
+			buffer += n_copy;
+			n_done += n_copy;
+		}
+	}
+
+	/* Update file object */
+
+	if ((start_write + n_done) > in->variant.file_variant.file_size)
+		in->variant.file_variant.file_size = (start_write + n_done);
+
+	in->dirty = 1;
+	return n_done;
+}
+
+int yaffs_wr_file(struct yaffs_obj *in, const u8 *buffer, loff_t offset,
+		  int n_bytes, int write_through)
+{
+	yaffs2_handle_hole(in, offset);
+	return yaffs_do_file_wr(in, buffer, offset, n_bytes, write_through);
+}
+
+/* ---------------------- File resizing stuff ------------------ */
+
+static void yaffs_prune_chunks(struct yaffs_obj *in, loff_t new_size)
+{
+
+	struct yaffs_dev *dev = in->my_dev;
+	loff_t old_size = in->variant.file_variant.file_size;
+	int i;
+	int chunk_id;
+	u32 dummy;
+	int last_del;
+	int start_del;
+
+	if (old_size > 0)
+		yaffs_addr_to_chunk(dev, old_size - 1, &last_del, &dummy);
+	else
+		last_del = 0;
+
+	yaffs_addr_to_chunk(dev, new_size + dev->data_bytes_per_chunk - 1,
+				&start_del, &dummy);
+	last_del++;
+	start_del++;
+
+	/* Delete backwards so that we don't end up with holes if
+	 * power is lost part-way through the operation.
+	 */
+	for (i = last_del; i >= start_del; i--) {
+		/* NB this could be optimised somewhat,
+		 * eg. could retrieve the tags and write them without
+		 * using yaffs_chunk_del
+		 */
+
+		chunk_id = yaffs_find_del_file_chunk(in, i, NULL);
+
+		if (chunk_id < 1)
+			continue;
+
+		if (chunk_id <
+		    (dev->internal_start_block * dev->param.chunks_per_block) ||
+		    chunk_id >=
+		    ((dev->internal_end_block + 1) *
+		      dev->param.chunks_per_block)) {
+			yaffs_trace(YAFFS_TRACE_ALWAYS,
+				"Found daft chunk_id %d for %d",
+				chunk_id, i);
+		} else {
+			in->n_data_chunks--;
+			yaffs_chunk_del(dev, chunk_id, 1, __LINE__);
+		}
+	}
+}
+
+void yaffs_resize_file_down(struct yaffs_obj *obj, loff_t new_size)
+{
+	int new_full;
+	u32 new_partial;
+	struct yaffs_dev *dev = obj->my_dev;
+
+	yaffs_addr_to_chunk(dev, new_size, &new_full, &new_partial);
+
+	yaffs_prune_chunks(obj, new_size);
+
+	if (new_partial != 0) {
+		int last_chunk = 1 + new_full;
+		u8 *local_buffer = yaffs_get_temp_buffer(dev);
+
+		/* Rewrite the last chunk with its new size and zero pad */
+		yaffs_rd_data_obj(obj, last_chunk, local_buffer);
+		memset(local_buffer + new_partial, 0,
+		       dev->data_bytes_per_chunk - new_partial);
+
+		yaffs_wr_data_obj(obj, last_chunk, local_buffer,
+				  new_partial, 1);
+
+		yaffs_release_temp_buffer(dev, local_buffer);
+	}
+
+	obj->variant.file_variant.file_size = new_size;
+
+	yaffs_prune_tree(dev, &obj->variant.file_variant);
+}
+
+int yaffs_resize_file(struct yaffs_obj *in, loff_t new_size)
+{
+	struct yaffs_dev *dev = in->my_dev;
+	loff_t old_size = in->variant.file_variant.file_size;
+
+	yaffs_flush_file_cache(in);
+	yaffs_invalidate_whole_cache(in);
+
+	yaffs_check_gc(dev, 0);
+
+	if (in->variant_type != YAFFS_OBJECT_TYPE_FILE)
+		return YAFFS_FAIL;
+
+	if (new_size == old_size)
+		return YAFFS_OK;
+
+	if (new_size > old_size) {
+		yaffs2_handle_hole(in, new_size);
+		in->variant.file_variant.file_size = new_size;
+	} else {
+		/* new_size < old_size */
+		yaffs_resize_file_down(in, new_size);
+	}
+
+	/* Write a new object header to reflect the resize.
+	 * show we've shrunk the file, if need be
+	 * Do this only if the file is not in the deleted directories
+	 * and is not shadowed.
+	 */
+	if (in->parent &&
+	    !in->is_shadowed &&
+	    in->parent->obj_id != YAFFS_OBJECTID_UNLINKED &&
+	    in->parent->obj_id != YAFFS_OBJECTID_DELETED)
+		yaffs_update_oh(in, NULL, 0, 0, 0, NULL);
+
+	return YAFFS_OK;
+}
+
+int yaffs_flush_file(struct yaffs_obj *in, int update_time, int data_sync)
+{
+	if (!in->dirty)
+		return YAFFS_OK;
+
+	yaffs_flush_file_cache(in);
+
+	if (data_sync)
+		return YAFFS_OK;
+
+	if (update_time)
+		yaffs_load_current_time(in, 0, 0);
+
+	return (yaffs_update_oh(in, NULL, 0, 0, 0, NULL) >= 0) ?
+				YAFFS_OK : YAFFS_FAIL;
+}
+
+
+/* yaffs_del_file deletes the whole file data
+ * and the inode associated with the file.
+ * It does not delete the links associated with the file.
+ */
+static int yaffs_unlink_file_if_needed(struct yaffs_obj *in)
+{
+	int ret_val;
+	int del_now = 0;
+	struct yaffs_dev *dev = in->my_dev;
+
+	if (!in->my_inode)
+		del_now = 1;
+
+	if (del_now) {
+		ret_val =
+		    yaffs_change_obj_name(in, in->my_dev->del_dir,
+					  _Y("deleted"), 0, 0);
+		yaffs_trace(YAFFS_TRACE_TRACING,
+			"yaffs: immediate deletion of file %d",
+			in->obj_id);
+		in->deleted = 1;
+		in->my_dev->n_deleted_files++;
+		if (dev->param.disable_soft_del || dev->param.is_yaffs2)
+			yaffs_resize_file(in, 0);
+		yaffs_soft_del_file(in);
+	} else {
+		ret_val =
+		    yaffs_change_obj_name(in, in->my_dev->unlinked_dir,
+					  _Y("unlinked"), 0, 0);
+	}
+	return ret_val;
+}
+
+int yaffs_del_file(struct yaffs_obj *in)
+{
+	int ret_val = YAFFS_OK;
+	int deleted;	/* Need to cache value on stack if in is freed */
+	struct yaffs_dev *dev = in->my_dev;
+
+	if (dev->param.disable_soft_del || dev->param.is_yaffs2)
+		yaffs_resize_file(in, 0);
+
+	if (in->n_data_chunks > 0) {
+		/* Use soft deletion if there is data in the file.
+		 * That won't be the case if it has been resized to zero.
+		 */
+		if (!in->unlinked)
+			ret_val = yaffs_unlink_file_if_needed(in);
+
+		deleted = in->deleted;
+
+		if (ret_val == YAFFS_OK && in->unlinked && !in->deleted) {
+			in->deleted = 1;
+			deleted = 1;
+			in->my_dev->n_deleted_files++;
+			yaffs_soft_del_file(in);
+		}
+		return deleted ? YAFFS_OK : YAFFS_FAIL;
+	} else {
+		/* The file has no data chunks so we toss it immediately */
+		yaffs_free_tnode(in->my_dev, in->variant.file_variant.top);
+		in->variant.file_variant.top = NULL;
+		yaffs_generic_obj_del(in);
+
+		return YAFFS_OK;
+	}
+}
+
+int yaffs_is_non_empty_dir(struct yaffs_obj *obj)
+{
+	return (obj &&
+		obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY) &&
+		!(list_empty(&obj->variant.dir_variant.children));
+}
+
+static int yaffs_del_dir(struct yaffs_obj *obj)
+{
+	/* First check that the directory is empty. */
+	if (yaffs_is_non_empty_dir(obj))
+		return YAFFS_FAIL;
+
+	return yaffs_generic_obj_del(obj);
+}
+
+static int yaffs_del_symlink(struct yaffs_obj *in)
+{
+	kfree(in->variant.symlink_variant.alias);
+	in->variant.symlink_variant.alias = NULL;
+
+	return yaffs_generic_obj_del(in);
+}
+
+static int yaffs_del_link(struct yaffs_obj *in)
+{
+	/* remove this hardlink from the list associated with the equivalent
+	 * object
+	 */
+	list_del_init(&in->hard_links);
+	return yaffs_generic_obj_del(in);
+}
+
+int yaffs_del_obj(struct yaffs_obj *obj)
+{
+	int ret_val = -1;
+
+	switch (obj->variant_type) {
+	case YAFFS_OBJECT_TYPE_FILE:
+		ret_val = yaffs_del_file(obj);
+		break;
+	case YAFFS_OBJECT_TYPE_DIRECTORY:
+		if (!list_empty(&obj->variant.dir_variant.dirty)) {
+			yaffs_trace(YAFFS_TRACE_BACKGROUND,
+				"Remove object %d from dirty directories",
+				obj->obj_id);
+			list_del_init(&obj->variant.dir_variant.dirty);
+		}
+		return yaffs_del_dir(obj);
+		break;
+	case YAFFS_OBJECT_TYPE_SYMLINK:
+		ret_val = yaffs_del_symlink(obj);
+		break;
+	case YAFFS_OBJECT_TYPE_HARDLINK:
+		ret_val = yaffs_del_link(obj);
+		break;
+	case YAFFS_OBJECT_TYPE_SPECIAL:
+		ret_val = yaffs_generic_obj_del(obj);
+		break;
+	case YAFFS_OBJECT_TYPE_UNKNOWN:
+		ret_val = 0;
+		break;		/* should not happen. */
+	}
+	return ret_val;
+}
+
+static int yaffs_unlink_worker(struct yaffs_obj *obj)
+{
+	int del_now = 0;
+
+	if (!obj)
+		return YAFFS_FAIL;
+
+	if (!obj->my_inode)
+		del_now = 1;
+
+	yaffs_update_parent(obj->parent);
+
+	if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
+		return yaffs_del_link(obj);
+	} else if (!list_empty(&obj->hard_links)) {
+		/* Curve ball: We're unlinking an object that has a hardlink.
+		 *
+		 * This problem arises because we are not strictly following
+		 * The Linux link/inode model.
+		 *
+		 * We can't really delete the object.
+		 * Instead, we do the following:
+		 * - Select a hardlink.
+		 * - Unhook it from the hard links
+		 * - Move it from its parent directory so that the rename works.
+		 * - Rename the object to the hardlink's name.
+		 * - Delete the hardlink
+		 */
+
+		struct yaffs_obj *hl;
+		struct yaffs_obj *parent;
+		int ret_val;
+		YCHAR name[YAFFS_MAX_NAME_LENGTH + 1];
+
+		hl = list_entry(obj->hard_links.next, struct yaffs_obj,
+				hard_links);
+
+		yaffs_get_obj_name(hl, name, YAFFS_MAX_NAME_LENGTH + 1);
+		parent = hl->parent;
+
+		list_del_init(&hl->hard_links);
+
+		yaffs_add_obj_to_dir(obj->my_dev->unlinked_dir, hl);
+
+		ret_val = yaffs_change_obj_name(obj, parent, name, 0, 0);
+
+		if (ret_val == YAFFS_OK)
+			ret_val = yaffs_generic_obj_del(hl);
+
+		return ret_val;
+
+	} else if (del_now) {
+		switch (obj->variant_type) {
+		case YAFFS_OBJECT_TYPE_FILE:
+			return yaffs_del_file(obj);
+			break;
+		case YAFFS_OBJECT_TYPE_DIRECTORY:
+			list_del_init(&obj->variant.dir_variant.dirty);
+			return yaffs_del_dir(obj);
+			break;
+		case YAFFS_OBJECT_TYPE_SYMLINK:
+			return yaffs_del_symlink(obj);
+			break;
+		case YAFFS_OBJECT_TYPE_SPECIAL:
+			return yaffs_generic_obj_del(obj);
+			break;
+		case YAFFS_OBJECT_TYPE_HARDLINK:
+		case YAFFS_OBJECT_TYPE_UNKNOWN:
+		default:
+			return YAFFS_FAIL;
+		}
+	} else if (yaffs_is_non_empty_dir(obj)) {
+		return YAFFS_FAIL;
+	} else {
+		return yaffs_change_obj_name(obj, obj->my_dev->unlinked_dir,
+						_Y("unlinked"), 0, 0);
+	}
+}
+
+static int yaffs_unlink_obj(struct yaffs_obj *obj)
+{
+	if (obj && obj->unlink_allowed)
+		return yaffs_unlink_worker(obj);
+
+	return YAFFS_FAIL;
+}
+
+int yaffs_unlinker(struct yaffs_obj *dir, const YCHAR *name)
+{
+	struct yaffs_obj *obj;
+
+	obj = yaffs_find_by_name(dir, name);
+	return yaffs_unlink_obj(obj);
+}
+
+/* Note:
+ * If old_name is NULL then we take old_dir as the object to be renamed.
+ */
+int yaffs_rename_obj(struct yaffs_obj *old_dir, const YCHAR *old_name,
+		     struct yaffs_obj *new_dir, const YCHAR *new_name)
+{
+	struct yaffs_obj *obj = NULL;
+	struct yaffs_obj *existing_target = NULL;
+	int force = 0;
+	int result;
+	struct yaffs_dev *dev;
+
+	if (!old_dir || old_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
+		BUG();
+		return YAFFS_FAIL;
+	}
+	if (!new_dir || new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
+		BUG();
+		return YAFFS_FAIL;
+	}
+
+	dev = old_dir->my_dev;
+
+#ifdef CONFIG_YAFFS_CASE_INSENSITIVE
+	/* Special case for case insemsitive systems.
+	 * While look-up is case insensitive, the name isn't.
+	 * Therefore we might want to change x.txt to X.txt
+	 */
+	if (old_dir == new_dir &&
+		old_name && new_name &&
+		yaffs_strcmp(old_name, new_name) == 0)
+		force = 1;
+#endif
+
+	if (yaffs_strnlen(new_name, YAFFS_MAX_NAME_LENGTH + 1) >
+	    YAFFS_MAX_NAME_LENGTH)
+		/* ENAMETOOLONG */
+		return YAFFS_FAIL;
+
+	if (old_name)
+		obj = yaffs_find_by_name(old_dir, old_name);
+	else{
+		obj = old_dir;
+		old_dir = obj->parent;
+	}
+
+	if (obj && obj->rename_allowed) {
+		/* Now handle an existing target, if there is one */
+		existing_target = yaffs_find_by_name(new_dir, new_name);
+		if (yaffs_is_non_empty_dir(existing_target)) {
+			return YAFFS_FAIL;	/* ENOTEMPTY */
+		} else if (existing_target && existing_target != obj) {
+			/* Nuke the target first, using shadowing,
+			 * but only if it isn't the same object.
+			 *
+			 * Note we must disable gc here otherwise it can mess
+			 * up the shadowing.
+			 *
+			 */
+			dev->gc_disable = 1;
+			yaffs_change_obj_name(obj, new_dir, new_name, force,
+					      existing_target->obj_id);
+			existing_target->is_shadowed = 1;
+			yaffs_unlink_obj(existing_target);
+			dev->gc_disable = 0;
+		}
+
+		result = yaffs_change_obj_name(obj, new_dir, new_name, 1, 0);
+
+		yaffs_update_parent(old_dir);
+		if (new_dir != old_dir)
+			yaffs_update_parent(new_dir);
+
+		return result;
+	}
+	return YAFFS_FAIL;
+}
+
+/*----------------------- Initialisation Scanning ---------------------- */
+
+void yaffs_handle_shadowed_obj(struct yaffs_dev *dev, int obj_id,
+			       int backward_scanning)
+{
+	struct yaffs_obj *obj;
+
+	if (backward_scanning) {
+		/* Handle YAFFS2 case (backward scanning)
+		 * If the shadowed object exists then ignore.
+		 */
+		obj = yaffs_find_by_number(dev, obj_id);
+		if (obj)
+			return;
+	}
+
+	/* Let's create it (if it does not exist) assuming it is a file so that
+	 * it can do shrinking etc.
+	 * We put it in unlinked dir to be cleaned up after the scanning
+	 */
+	obj =
+	    yaffs_find_or_create_by_number(dev, obj_id, YAFFS_OBJECT_TYPE_FILE);
+	if (!obj)
+		return;
+	obj->is_shadowed = 1;
+	yaffs_add_obj_to_dir(dev->unlinked_dir, obj);
+	obj->variant.file_variant.shrink_size = 0;
+	obj->valid = 1;		/* So that we don't read any other info. */
+}
+
+void yaffs_link_fixup(struct yaffs_dev *dev, struct list_head *hard_list)
+{
+	struct list_head *lh;
+	struct list_head *save;
+	struct yaffs_obj *hl;
+	struct yaffs_obj *in;
+
+	list_for_each_safe(lh, save, hard_list) {
+		hl = list_entry(lh, struct yaffs_obj, hard_links);
+		in = yaffs_find_by_number(dev,
+					hl->variant.hardlink_variant.equiv_id);
+
+		if (in) {
+			/* Add the hardlink pointers */
+			hl->variant.hardlink_variant.equiv_obj = in;
+			list_add(&hl->hard_links, &in->hard_links);
+		} else {
+			/* Todo Need to report/handle this better.
+			 * Got a problem... hardlink to a non-existant object
+			 */
+			hl->variant.hardlink_variant.equiv_obj = NULL;
+			INIT_LIST_HEAD(&hl->hard_links);
+		}
+	}
+}
+
+static void yaffs_strip_deleted_objs(struct yaffs_dev *dev)
+{
+	/*
+	 *  Sort out state of unlinked and deleted objects after scanning.
+	 */
+	struct list_head *i;
+	struct list_head *n;
+	struct yaffs_obj *l;
+
+	if (dev->read_only)
+		return;
+
+	/* Soft delete all the unlinked files */
+	list_for_each_safe(i, n,
+			   &dev->unlinked_dir->variant.dir_variant.children) {
+		l = list_entry(i, struct yaffs_obj, siblings);
+		yaffs_del_obj(l);
+	}
+
+	list_for_each_safe(i, n, &dev->del_dir->variant.dir_variant.children) {
+		l = list_entry(i, struct yaffs_obj, siblings);
+		yaffs_del_obj(l);
+	}
+}
+
+/*
+ * This code iterates through all the objects making sure that they are rooted.
+ * Any unrooted objects are re-rooted in lost+found.
+ * An object needs to be in one of:
+ * - Directly under deleted, unlinked
+ * - Directly or indirectly under root.
+ *
+ * Note:
+ *  This code assumes that we don't ever change the current relationships
+ *  between directories:
+ *   root_dir->parent == unlinked_dir->parent == del_dir->parent == NULL
+ *   lost-n-found->parent == root_dir
+ *
+ * This fixes the problem where directories might have inadvertently been
+ * deleted leaving the object "hanging" without being rooted in the
+ * directory tree.
+ */
+
+static int yaffs_has_null_parent(struct yaffs_dev *dev, struct yaffs_obj *obj)
+{
+	return (obj == dev->del_dir ||
+		obj == dev->unlinked_dir || obj == dev->root_dir);
+}
+
+static void yaffs_fix_hanging_objs(struct yaffs_dev *dev)
+{
+	struct yaffs_obj *obj;
+	struct yaffs_obj *parent;
+	int i;
+	struct list_head *lh;
+	struct list_head *n;
+	int depth_limit;
+	int hanging;
+
+	if (dev->read_only)
+		return;
+
+	/* Iterate through the objects in each hash entry,
+	 * looking at each object.
+	 * Make sure it is rooted.
+	 */
+
+	for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
+		list_for_each_safe(lh, n, &dev->obj_bucket[i].list) {
+			obj = list_entry(lh, struct yaffs_obj, hash_link);
+			parent = obj->parent;
+
+			if (yaffs_has_null_parent(dev, obj)) {
+				/* These directories are not hanging */
+				hanging = 0;
+			} else if (!parent ||
+				   parent->variant_type !=
+				   YAFFS_OBJECT_TYPE_DIRECTORY) {
+				hanging = 1;
+			} else if (yaffs_has_null_parent(dev, parent)) {
+				hanging = 0;
+			} else {
+				/*
+				 * Need to follow the parent chain to
+				 * see if it is hanging.
+				 */
+				hanging = 0;
+				depth_limit = 100;
+
+				while (parent != dev->root_dir &&
+				       parent->parent &&
+				       parent->parent->variant_type ==
+				       YAFFS_OBJECT_TYPE_DIRECTORY &&
+				       depth_limit > 0) {
+					parent = parent->parent;
+					depth_limit--;
+				}
+				if (parent != dev->root_dir)
+					hanging = 1;
+			}
+			if (hanging) {
+				yaffs_trace(YAFFS_TRACE_SCAN,
+					"Hanging object %d moved to lost and found",
+					obj->obj_id);
+				yaffs_add_obj_to_dir(dev->lost_n_found, obj);
+			}
+		}
+	}
+}
+
+/*
+ * Delete directory contents for cleaning up lost and found.
+ */
+static void yaffs_del_dir_contents(struct yaffs_obj *dir)
+{
+	struct yaffs_obj *obj;
+	struct list_head *lh;
+	struct list_head *n;
+
+	if (dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
+		BUG();
+
+	list_for_each_safe(lh, n, &dir->variant.dir_variant.children) {
+		obj = list_entry(lh, struct yaffs_obj, siblings);
+		if (obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY)
+			yaffs_del_dir_contents(obj);
+		yaffs_trace(YAFFS_TRACE_SCAN,
+			"Deleting lost_found object %d",
+			obj->obj_id);
+		yaffs_unlink_obj(obj);
+	}
+}
+
+static void yaffs_empty_l_n_f(struct yaffs_dev *dev)
+{
+	yaffs_del_dir_contents(dev->lost_n_found);
+}
+
+
+struct yaffs_obj *yaffs_find_by_name(struct yaffs_obj *directory,
+				     const YCHAR *name)
+{
+	int sum;
+	struct list_head *i;
+	YCHAR buffer[YAFFS_MAX_NAME_LENGTH + 1];
+	struct yaffs_obj *l;
+
+	if (!name)
+		return NULL;
+
+	if (!directory) {
+		yaffs_trace(YAFFS_TRACE_ALWAYS,
+			"tragedy: yaffs_find_by_name: null pointer directory"
+			);
+		BUG();
+		return NULL;
+	}
+	if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
+		yaffs_trace(YAFFS_TRACE_ALWAYS,
+			"tragedy: yaffs_find_by_name: non-directory"
+			);
+		BUG();
+	}
+
+	sum = yaffs_calc_name_sum(name);
+
+	list_for_each(i, &directory->variant.dir_variant.children) {
+		l = list_entry(i, struct yaffs_obj, siblings);
+
+		if (l->parent != directory)
+			BUG();
+
+		yaffs_check_obj_details_loaded(l);
+
+		/* Special case for lost-n-found */
+		if (l->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
+			if (!yaffs_strcmp(name, YAFFS_LOSTNFOUND_NAME))
+				return l;
+		} else if (l->sum == sum || l->hdr_chunk <= 0) {
+			/* LostnFound chunk called Objxxx
+			 * Do a real check
+			 */
+			yaffs_get_obj_name(l, buffer,
+				YAFFS_MAX_NAME_LENGTH + 1);
+			if (!yaffs_strncmp(name, buffer, YAFFS_MAX_NAME_LENGTH))
+				return l;
+		}
+	}
+	return NULL;
+}
+
+/* GetEquivalentObject dereferences any hard links to get to the
+ * actual object.
+ */
+
+struct yaffs_obj *yaffs_get_equivalent_obj(struct yaffs_obj *obj)
+{
+	if (obj && obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
+		obj = obj->variant.hardlink_variant.equiv_obj;
+		yaffs_check_obj_details_loaded(obj);
+	}
+	return obj;
+}
+
+/*
+ *  A note or two on object names.
+ *  * If the object name is missing, we then make one up in the form objnnn
+ *
+ *  * ASCII names are stored in the object header's name field from byte zero
+ *  * Unicode names are historically stored starting from byte zero.
+ *
+ * Then there are automatic Unicode names...
+ * The purpose of these is to save names in a way that can be read as
+ * ASCII or Unicode names as appropriate, thus allowing a Unicode and ASCII
+ * system to share files.
+ *
+ * These automatic unicode are stored slightly differently...
+ *  - If the name can fit in the ASCII character space then they are saved as
+ *    ascii names as per above.
+ *  - If the name needs Unicode then the name is saved in Unicode
+ *    starting at oh->name[1].
+
+ */
+static void yaffs_fix_null_name(struct yaffs_obj *obj, YCHAR *name,
+				int buffer_size)
+{
+	/* Create an object name if we could not find one. */
+	if (yaffs_strnlen(name, YAFFS_MAX_NAME_LENGTH) == 0) {
+		YCHAR local_name[20];
+		YCHAR num_string[20];
+		YCHAR *x = &num_string[19];
+		unsigned v = obj->obj_id;
+		num_string[19] = 0;
+		while (v > 0) {
+			x--;
+			*x = '0' + (v % 10);
+			v /= 10;
+		}
+		/* make up a name */
+		yaffs_strcpy(local_name, YAFFS_LOSTNFOUND_PREFIX);
+		yaffs_strcat(local_name, x);
+		yaffs_strncpy(name, local_name, buffer_size - 1);
+	}
+}
+
+int yaffs_get_obj_name(struct yaffs_obj *obj, YCHAR *name, int buffer_size)
+{
+	memset(name, 0, buffer_size * sizeof(YCHAR));
+	yaffs_check_obj_details_loaded(obj);
+	if (obj->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
+		yaffs_strncpy(name, YAFFS_LOSTNFOUND_NAME, buffer_size - 1);
+	} else if (obj->short_name[0]) {
+		yaffs_strcpy(name, obj->short_name);
+	} else if (obj->hdr_chunk > 0) {
+		u8 *buffer = yaffs_get_temp_buffer(obj->my_dev);
+
+		struct yaffs_obj_hdr *oh = (struct yaffs_obj_hdr *)buffer;
+
+		memset(buffer, 0, obj->my_dev->data_bytes_per_chunk);
+
+		if (obj->hdr_chunk > 0) {
+			yaffs_rd_chunk_tags_nand(obj->my_dev,
+						 obj->hdr_chunk,
+						 buffer, NULL);
+		}
+		yaffs_load_name_from_oh(obj->my_dev, name, oh->name,
+					buffer_size);
+
+		yaffs_release_temp_buffer(obj->my_dev, buffer);
+	}
+
+	yaffs_fix_null_name(obj, name, buffer_size);
+
+	return yaffs_strnlen(name, YAFFS_MAX_NAME_LENGTH);
+}
+
+loff_t yaffs_get_obj_length(struct yaffs_obj *obj)
+{
+	/* Dereference any hard linking */
+	obj = yaffs_get_equivalent_obj(obj);
+
+	if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
+		return obj->variant.file_variant.file_size;
+	if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
+		if (!obj->variant.symlink_variant.alias)
+			return 0;
+		return yaffs_strnlen(obj->variant.symlink_variant.alias,
+				     YAFFS_MAX_ALIAS_LENGTH);
+	} else {
+		/* Only a directory should drop through to here */
+		return obj->my_dev->data_bytes_per_chunk;
+	}
+}
+
+int yaffs_get_obj_link_count(struct yaffs_obj *obj)
+{
+	int count = 0;
+	struct list_head *i;
+
+	if (!obj->unlinked)
+		count++;	/* the object itself */
+
+	list_for_each(i, &obj->hard_links)
+	    count++;		/* add the hard links; */
+
+	return count;
+}
+
+int yaffs_get_obj_inode(struct yaffs_obj *obj)
+{
+	obj = yaffs_get_equivalent_obj(obj);
+
+	return obj->obj_id;
+}
+
+unsigned yaffs_get_obj_type(struct yaffs_obj *obj)
+{
+	obj = yaffs_get_equivalent_obj(obj);
+
+	switch (obj->variant_type) {
+	case YAFFS_OBJECT_TYPE_FILE:
+		return DT_REG;
+		break;
+	case YAFFS_OBJECT_TYPE_DIRECTORY:
+		return DT_DIR;
+		break;
+	case YAFFS_OBJECT_TYPE_SYMLINK:
+		return DT_LNK;
+		break;
+	case YAFFS_OBJECT_TYPE_HARDLINK:
+		return DT_REG;
+		break;
+	case YAFFS_OBJECT_TYPE_SPECIAL:
+		if (S_ISFIFO(obj->yst_mode))
+			return DT_FIFO;
+		if (S_ISCHR(obj->yst_mode))
+			return DT_CHR;
+		if (S_ISBLK(obj->yst_mode))
+			return DT_BLK;
+		if (S_ISSOCK(obj->yst_mode))
+			return DT_SOCK;
+		return DT_REG;
+		break;
+	default:
+		return DT_REG;
+		break;
+	}
+}
+
+YCHAR *yaffs_get_symlink_alias(struct yaffs_obj *obj)
+{
+	obj = yaffs_get_equivalent_obj(obj);
+	if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK)
+		return yaffs_clone_str(obj->variant.symlink_variant.alias);
+	else
+		return yaffs_clone_str(_Y(""));
+}
+
+/*--------------------------- Initialisation code -------------------------- */
+
+static int yaffs_check_dev_fns(const struct yaffs_dev *dev)
+{
+	/* Common functions, gotta have */
+	if (!dev->param.erase_fn || !dev->param.initialise_flash_fn)
+		return 0;
+
+	/* Can use the "with tags" style interface for yaffs1 or yaffs2 */
+	if (dev->param.write_chunk_tags_fn &&
+	    dev->param.read_chunk_tags_fn &&
+	    !dev->param.write_chunk_fn &&
+	    !dev->param.read_chunk_fn &&
+	    dev->param.bad_block_fn && dev->param.query_block_fn)
+		return 1;
+
+	/* Can use the "spare" style interface for yaffs1 */
+	if (!dev->param.is_yaffs2 &&
+	    !dev->param.write_chunk_tags_fn &&
+	    !dev->param.read_chunk_tags_fn &&
+	    dev->param.write_chunk_fn &&
+	    dev->param.read_chunk_fn &&
+	    !dev->param.bad_block_fn && !dev->param.query_block_fn)
+		return 1;
+
+	return 0;		/* bad */
+}
+
+static int yaffs_create_initial_dir(struct yaffs_dev *dev)
+{
+	/* Initialise the unlinked, deleted, root and lost+found directories */
+	dev->lost_n_found = dev->root_dir = NULL;
+	dev->unlinked_dir = dev->del_dir = NULL;
+	dev->unlinked_dir =
+	    yaffs_create_fake_dir(dev, YAFFS_OBJECTID_UNLINKED, S_IFDIR);
+	dev->del_dir =
+	    yaffs_create_fake_dir(dev, YAFFS_OBJECTID_DELETED, S_IFDIR);
+	dev->root_dir =
+	    yaffs_create_fake_dir(dev, YAFFS_OBJECTID_ROOT,
+				  YAFFS_ROOT_MODE | S_IFDIR);
+	dev->lost_n_found =
+	    yaffs_create_fake_dir(dev, YAFFS_OBJECTID_LOSTNFOUND,
+				  YAFFS_LOSTNFOUND_MODE | S_IFDIR);
+
+	if (dev->lost_n_found && dev->root_dir && dev->unlinked_dir
+	    && dev->del_dir) {
+		yaffs_add_obj_to_dir(dev->root_dir, dev->lost_n_found);
+		return YAFFS_OK;
+	}
+	return YAFFS_FAIL;
+}
+
+int yaffs_guts_initialise(struct yaffs_dev *dev)
+{
+	int init_failed = 0;
+	unsigned x;
+	int bits;
+
+	yaffs_trace(YAFFS_TRACE_TRACING, "yaffs: yaffs_guts_initialise()");
+
+	/* Check stuff that must be set */
+
+	if (!dev) {
+		yaffs_trace(YAFFS_TRACE_ALWAYS,
+			"yaffs: Need a device"
+			);
+		return YAFFS_FAIL;
+	}
+
+	if (dev->is_mounted) {
+		yaffs_trace(YAFFS_TRACE_ALWAYS, "device already mounted");
+		return YAFFS_FAIL;
+	}
+
+	dev->internal_start_block = dev->param.start_block;
+	dev->internal_end_block = dev->param.end_block;
+	dev->block_offset = 0;
+	dev->chunk_offset = 0;
+	dev->n_free_chunks = 0;
+
+	dev->gc_block = 0;
+
+	if (dev->param.start_block == 0) {
+		dev->internal_start_block = dev->param.start_block + 1;
+		dev->internal_end_block = dev->param.end_block + 1;
+		dev->block_offset = 1;
+		dev->chunk_offset = dev->param.chunks_per_block;
+	}
+
+	/* Check geometry parameters. */
+
+	if ((!dev->param.inband_tags && dev->param.is_yaffs2 &&
+		dev->param.total_bytes_per_chunk < 1024) ||
+		(!dev->param.is_yaffs2 &&
+			dev->param.total_bytes_per_chunk < 512) ||
+		(dev->param.inband_tags && !dev->param.is_yaffs2) ||
+		 dev->param.chunks_per_block < 2 ||
+		 dev->param.n_reserved_blocks < 2 ||
+		dev->internal_start_block <= 0 ||
+		dev->internal_end_block <= 0 ||
+		dev->internal_end_block <=
+		(dev->internal_start_block + dev->param.n_reserved_blocks + 2)
+		) {
+		/* otherwise it is too small */
+		yaffs_trace(YAFFS_TRACE_ALWAYS,
+			"NAND geometry problems: chunk size %d, type is yaffs%s, inband_tags %d ",
+			dev->param.total_bytes_per_chunk,
+			dev->param.is_yaffs2 ? "2" : "",
+			dev->param.inband_tags);
+		return YAFFS_FAIL;
+	}
+
+	if (yaffs_init_nand(dev) != YAFFS_OK) {
+		yaffs_trace(YAFFS_TRACE_ALWAYS, "InitialiseNAND failed");
+		return YAFFS_FAIL;
+	}
+
+	/* Sort out space for inband tags, if required */
+	if (dev->param.inband_tags)
+		dev->data_bytes_per_chunk =
+		    dev->param.total_bytes_per_chunk -
+		    sizeof(struct yaffs_packed_tags2_tags_only);
+	else
+		dev->data_bytes_per_chunk = dev->param.total_bytes_per_chunk;
+
+	/* Got the right mix of functions? */
+	if (!yaffs_check_dev_fns(dev)) {
+		/* Function missing */
+		yaffs_trace(YAFFS_TRACE_ALWAYS,
+			"device function(s) missing or wrong");
+
+		return YAFFS_FAIL;
+	}
+
+	/* Finished with most checks. Further checks happen later on too. */
+
+	dev->is_mounted = 1;
+
+	/* OK now calculate a few things for the device */
+
+	/*
+	 *  Calculate all the chunk size manipulation numbers:
+	 */
+	x = dev->data_bytes_per_chunk;
+	/* We always use dev->chunk_shift and dev->chunk_div */
+	dev->chunk_shift = calc_shifts(x);
+	x >>= dev->chunk_shift;
+	dev->chunk_div = x;
+	/* We only use chunk mask if chunk_div is 1 */
+	dev->chunk_mask = (1 << dev->chunk_shift) - 1;
+
+	/*
+	 * Calculate chunk_grp_bits.
+	 * We need to find the next power of 2 > than internal_end_block
+	 */
+
+	x = dev->param.chunks_per_block * (dev->internal_end_block + 1);
+
+	bits = calc_shifts_ceiling(x);
+
+	/* Set up tnode width if wide tnodes are enabled. */
+	if (!dev->param.wide_tnodes_disabled) {
+		/* bits must be even so that we end up with 32-bit words */
+		if (bits & 1)
+			bits++;
+		if (bits < 16)
+			dev->tnode_width = 16;
+		else
+			dev->tnode_width = bits;
+	} else {
+		dev->tnode_width = 16;
+	}
+
+	dev->tnode_mask = (1 << dev->tnode_width) - 1;
+
+	/* Level0 Tnodes are 16 bits or wider (if wide tnodes are enabled),
+	 * so if the bitwidth of the
+	 * chunk range we're using is greater than 16 we need
+	 * to figure out chunk shift and chunk_grp_size
+	 */
+
+	if (bits <= dev->tnode_width)
+		dev->chunk_grp_bits = 0;
+	else
+		dev->chunk_grp_bits = bits - dev->tnode_width;
+
+	dev->tnode_size = (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8;
+	if (dev->tnode_size < sizeof(struct yaffs_tnode))
+		dev->tnode_size = sizeof(struct yaffs_tnode);
+
+	dev->chunk_grp_size = 1 << dev->chunk_grp_bits;
+
+	if (dev->param.chunks_per_block < dev->chunk_grp_size) {
+		/* We have a problem because the soft delete won't work if
+		 * the chunk group size > chunks per block.
+		 * This can be remedied by using larger "virtual blocks".
+		 */
+		yaffs_trace(YAFFS_TRACE_ALWAYS, "chunk group too large");
+
+		return YAFFS_FAIL;
+	}
+
+	/* Finished verifying the device, continue with initialisation */
+
+	/* More device initialisation */
+	dev->all_gcs = 0;
+	dev->passive_gc_count = 0;
+	dev->oldest_dirty_gc_count = 0;
+	dev->bg_gcs = 0;
+	dev->gc_block_finder = 0;
+	dev->buffered_block = -1;
+	dev->doing_buffered_block_rewrite = 0;
+	dev->n_deleted_files = 0;
+	dev->n_bg_deletions = 0;
+	dev->n_unlinked_files = 0;
+	dev->n_ecc_fixed = 0;
+	dev->n_ecc_unfixed = 0;
+	dev->n_tags_ecc_fixed = 0;
+	dev->n_tags_ecc_unfixed = 0;
+	dev->n_erase_failures = 0;
+	dev->n_erased_blocks = 0;
+	dev->gc_disable = 0;
+	dev->has_pending_prioritised_gc = 1;
+		/* Assume the worst for now, will get fixed on first GC */
+	INIT_LIST_HEAD(&dev->dirty_dirs);
+	dev->oldest_dirty_seq = 0;
+	dev->oldest_dirty_block = 0;
+
+	/* Initialise temporary buffers and caches. */
+	if (!yaffs_init_tmp_buffers(dev))
+		init_failed = 1;
+
+	dev->cache = NULL;
+	dev->gc_cleanup_list = NULL;
+
+	if (!init_failed && dev->param.n_caches > 0) {
+		int i;
+		void *buf;
+		int cache_bytes =
+		    dev->param.n_caches * sizeof(struct yaffs_cache);
+
+		if (dev->param.n_caches > YAFFS_MAX_SHORT_OP_CACHES)
+			dev->param.n_caches = YAFFS_MAX_SHORT_OP_CACHES;
+
+		dev->cache = kmalloc(cache_bytes, GFP_NOFS);
+
+		buf = (u8 *) dev->cache;
+
+		if (dev->cache)
+			memset(dev->cache, 0, cache_bytes);
+
+		for (i = 0; i < dev->param.n_caches && buf; i++) {
+			dev->cache[i].object = NULL;
+			dev->cache[i].last_use = 0;
+			dev->cache[i].dirty = 0;
+			dev->cache[i].data = buf =
+			    kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
+		}
+		if (!buf)
+			init_failed = 1;
+
+		dev->cache_last_use = 0;
+	}
+
+	dev->cache_hits = 0;
+
+	if (!init_failed) {
+		dev->gc_cleanup_list =
+		    kmalloc(dev->param.chunks_per_block * sizeof(u32),
+					GFP_NOFS);
+		if (!dev->gc_cleanup_list)
+			init_failed = 1;
+	}
+
+	if (dev->param.is_yaffs2)
+		dev->param.use_header_file_size = 1;
+
+	if (!init_failed && !yaffs_init_blocks(dev))
+		init_failed = 1;
+
+	yaffs_init_tnodes_and_objs(dev);
+
+	if (!init_failed && !yaffs_create_initial_dir(dev))
+		init_failed = 1;
+
+	if (!init_failed && dev->param.is_yaffs2 &&
+		!dev->param.disable_summary &&
+		!yaffs_summary_init(dev))
+		init_failed = 1;
+
+	if (!init_failed) {
+		/* Now scan the flash. */
+		if (dev->param.is_yaffs2) {
+			if (yaffs2_checkpt_restore(dev)) {
+				yaffs_check_obj_details_loaded(dev->root_dir);
+				yaffs_trace(YAFFS_TRACE_CHECKPOINT |
+					YAFFS_TRACE_MOUNT,
+					"yaffs: restored from checkpoint"
+					);
+			} else {
+
+				/* Clean up the mess caused by an aborted
+				 * checkpoint load then scan backwards.
+				 */
+				yaffs_deinit_blocks(dev);
+
+				yaffs_deinit_tnodes_and_objs(dev);
+
+				dev->n_erased_blocks = 0;
+				dev->n_free_chunks = 0;
+				dev->alloc_block = -1;
+				dev->alloc_page = -1;
+				dev->n_deleted_files = 0;
+				dev->n_unlinked_files = 0;
+				dev->n_bg_deletions = 0;
+
+				if (!init_failed && !yaffs_init_blocks(dev))
+					init_failed = 1;
+
+				yaffs_init_tnodes_and_objs(dev);
+
+				if (!init_failed
+				    && !yaffs_create_initial_dir(dev))
+					init_failed = 1;
+
+				if (!init_failed && !yaffs2_scan_backwards(dev))
+					init_failed = 1;
+			}
+		} else if (!yaffs1_scan(dev)) {
+			init_failed = 1;
+		}
+
+		yaffs_strip_deleted_objs(dev);
+		yaffs_fix_hanging_objs(dev);
+		if (dev->param.empty_lost_n_found)
+			yaffs_empty_l_n_f(dev);
+	}
+
+	if (init_failed) {
+		/* Clean up the mess */
+		yaffs_trace(YAFFS_TRACE_TRACING,
+		  "yaffs: yaffs_guts_initialise() aborted.");
+
+		yaffs_deinitialise(dev);
+		return YAFFS_FAIL;
+	}
+
+	/* Zero out stats */
+	dev->n_page_reads = 0;
+	dev->n_page_writes = 0;
+	dev->n_erasures = 0;
+	dev->n_gc_copies = 0;
+	dev->n_retried_writes = 0;
+
+	dev->n_retired_blocks = 0;
+
+	yaffs_verify_free_chunks(dev);
+	yaffs_verify_blocks(dev);
+
+	/* Clean up any aborted checkpoint data */
+	if (!dev->is_checkpointed && dev->blocks_in_checkpt > 0)
+		yaffs2_checkpt_invalidate(dev);
+
+	yaffs_trace(YAFFS_TRACE_TRACING,
+	  "yaffs: yaffs_guts_initialise() done.");
+	return YAFFS_OK;
+}
+
+void yaffs_deinitialise(struct yaffs_dev *dev)
+{
+	if (dev->is_mounted) {
+		int i;
+
+		yaffs_deinit_blocks(dev);
+		yaffs_deinit_tnodes_and_objs(dev);
+		yaffs_summary_deinit(dev);
+
+		if (dev->param.n_caches > 0 && dev->cache) {
+
+			for (i = 0; i < dev->param.n_caches; i++) {
+				kfree(dev->cache[i].data);
+				dev->cache[i].data = NULL;
+			}
+
+			kfree(dev->cache);
+			dev->cache = NULL;
+		}
+
+		kfree(dev->gc_cleanup_list);
+
+		for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++)
+			kfree(dev->temp_buffer[i].buffer);
+
+		dev->is_mounted = 0;
+
+		if (dev->param.deinitialise_flash_fn)
+			dev->param.deinitialise_flash_fn(dev);
+	}
+}
+
+int yaffs_count_free_chunks(struct yaffs_dev *dev)
+{
+	int n_free = 0;
+	int b;
+	struct yaffs_block_info *blk;
+
+	blk = dev->block_info;
+	for (b = dev->internal_start_block; b <= dev->internal_end_block; b++) {
+		switch (blk->block_state) {
+		case YAFFS_BLOCK_STATE_EMPTY:
+		case YAFFS_BLOCK_STATE_ALLOCATING:
+		case YAFFS_BLOCK_STATE_COLLECTING:
+		case YAFFS_BLOCK_STATE_FULL:
+			n_free +=
+			    (dev->param.chunks_per_block - blk->pages_in_use +
+			     blk->soft_del_pages);
+			break;
+		default:
+			break;
+		}
+		blk++;
+	}
+	return n_free;
+}
+
+int yaffs_get_n_free_chunks(struct yaffs_dev *dev)
+{
+	/* This is what we report to the outside world */
+	int n_free;
+	int n_dirty_caches;
+	int blocks_for_checkpt;
+	int i;
+
+	n_free = dev->n_free_chunks;
+	n_free += dev->n_deleted_files;
+
+	/* Now count and subtract the number of dirty chunks in the cache. */
+
+	for (n_dirty_caches = 0, i = 0; i < dev->param.n_caches; i++) {
+		if (dev->cache[i].dirty)
+			n_dirty_caches++;
+	}
+
+	n_free -= n_dirty_caches;
+
+	n_free -=
+	    ((dev->param.n_reserved_blocks + 1) * dev->param.chunks_per_block);
+
+	/* Now figure checkpoint space and report that... */
+	blocks_for_checkpt = yaffs_calc_checkpt_blocks_required(dev);
+
+	n_free -= (blocks_for_checkpt * dev->param.chunks_per_block);
+
+	if (n_free < 0)
+		n_free = 0;
+
+	return n_free;
+}
+
+/*\
+ * Marshalling functions to get loff_t file sizes into aand out of
+ * object headers.
+ */
+void yaffs_oh_size_load(struct yaffs_obj_hdr *oh, loff_t fsize)
+{
+	oh->file_size_low = (fsize & 0xFFFFFFFF);
+	oh->file_size_high = ((fsize >> 32) & 0xFFFFFFFF);
+}
+
+loff_t yaffs_oh_to_size(struct yaffs_obj_hdr *oh)
+{
+	loff_t retval;
+
+	if (~(oh->file_size_high))
+		retval = (((loff_t) oh->file_size_high) << 32) |
+			(((loff_t) oh->file_size_low) & 0xFFFFFFFF);
+	else
+		retval = (loff_t) oh->file_size_low;
+
+	return retval;
+}