1 files changed, 5164 insertions, 0 deletions

diff --git a/fs/yaffs2/yaffs_guts.c b/fs/yaffs2/yaffs_guts.c
new file mode 100644
index 00000000000..f4ae9deed72
--- /dev/null
+++ b/fs/yaffs2/yaffs_guts.c
@@ -0,0 +1,5164 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yportenv.h"
+#include "yaffs_trace.h"
+
+#include "yaffs_guts.h"
+#include "yaffs_tagsvalidity.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"
+
+/* 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 */
+
+static 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 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 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].line = 0;   /* not in use */
+                dev->temp_buffer[i].buffer = buf =
+                    kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
+        }
+
+        return buf ? YAFFS_OK : YAFFS_FAIL;
+}
+
+u8 *yaffs_get_temp_buffer(struct yaffs_dev * dev, int line_no)
+{
+        int i, j;
+
+        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].line == 0) {
+                        dev->temp_buffer[i].line = line_no;
+                        if ((i + 1) > dev->max_temp) {
+                                dev->max_temp = i + 1;
+                                for (j = 0; j <= i; j++)
+                                        dev->temp_buffer[j].max_line =
+                                            dev->temp_buffer[j].line;
+                        }
+
+                        return dev->temp_buffer[i].buffer;
+                }
+        }
+
+        yaffs_trace(YAFFS_TRACE_BUFFERS,
+                "Out of temp buffers at line %d, other held by lines:",
+                line_no);
+        for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++)
+                yaffs_trace(YAFFS_TRACE_BUFFERS," %d", dev->temp_buffer[i].line);
+
+        /*
+         * 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 line_no)
+{
+        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].line = 0;
+                        return;
+                }
+        }
+
+        if (buffer) {
+                /* assume it is an unmanaged one. */
+                yaffs_trace(YAFFS_TRACE_BUFFERS,
+                  "Releasing unmanaged temp buffer in line %d",
+                   line_no);
+                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 this */
+                        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)
+{
+        n = abs(n);
+        return n % YAFFS_NOBJECT_BUCKETS;
+}
+
+/*
+ * Access functions to useful fake objects.
+ * Note that root might have a presence in NAND if permissions are set.
+ */
+
+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, __LINE__);
+        struct yaffs_ext_tags tags;
+        int result;
+
+        result = 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, __LINE__);
+
+        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, __LINE__);
+        int result;
+
+        result = 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, __LINE__);
+
+        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)) {
+                /* Not enough space to allocate 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)
+{
+        if (dev->alloc_block > 0) {
+                struct yaffs_block_info *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_retired_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, __LINE__);
+
+                        memset(buffer, 0xff, dev->data_bytes_per_chunk);
+                        yaffs_init_tags(&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, __LINE__);
+                }
+        }
+
+        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;
+
+        const YUCHAR *bname = (const YUCHAR *)name;
+        if (bname) {
+                while ((*bname) && (i < (YAFFS_MAX_NAME_LENGTH / 2))) {
+
+                        /* 0x1f mask is case insensitive */
+                        sum += ((*bname) & 0x1f) * i;
+                        i++;
+                        bname++;
+                }
+        }
+        return sum;
+}
+
+void yaffs_set_obj_name(struct yaffs_obj *obj, const YCHAR * name)
+{
+#ifndef CONFIG_YAFFS_NO_SHORT_NAMES
+        memset(obj->short_name, 0, sizeof(obj->short_name));
+        if (name && 
+                strnlen(name, YAFFS_SHORT_NAME_LENGTH + 1) <=
+            YAFFS_SHORT_NAME_LENGTH)
+                strcpy(obj->short_name, name);
+        else
+                obj->short_name[0] = _Y('\0');
+#endif
+        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
+}
+
+/*-------------------- 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 >> ( /*dev->tnode_width - */ 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;
+}
+
+/* AddOrFindLevel0Tnode 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, then 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) {
+                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) {
+
+                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"
+                                );
+                        YBUG();
+                }
+
+                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 ever
+                 * 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.
+                         * Forward scanning YAFFS2: The new one is what we use, dump the old 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
+                                 * Use existing.
+                                 * 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) {
+                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 {
+                                                /* Hoosterman... how could this happen? */
+                                        }
+                                }
+                        }
+                        return (all_done) ? 1 : 0;
+                } else if (level == 0) {
+
+                        for (i = YAFFS_NTNODES_LEVEL0 - 1; i >= 0; i--) {
+                                the_chunk = yaffs_get_group_base(dev, tn, i);
+                                if (the_chunk) {
+                                        /* Note this does not find the real chunk, only the chunk group.
+                                         * We make an assumption that a chunk group is not larger than
+                                         * a block.
+                                         */
+                                        yaffs_soft_del_chunk(dev, the_chunk);
+                                        yaffs_load_tnode_0(dev, tn, i, 0);
+                                }
+
+                        }
+                        return 1;
+
+                }
+
+        }
+
+        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"
+                        );
+                YBUG();
+                return;
+        }
+        if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
+                yaffs_trace(YAFFS_TRACE_ALWAYS,
+                        "tragedy: Trying to add an object to a non-directory"
+                        );
+                YBUG();
+        }
+
+        if (obj->siblings.prev == NULL) {
+                /* Not initialised */
+                YBUG();
+        }
+
+        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"
+                        );
+                YBUG();
+        }
+
+        /* TODO: Do we need this different handling for YAFFS2 and YAFFS1?? */
+        if (obj->my_dev->param.is_yaffs2)
+                unlink_op = (new_dir == obj->my_dev->unlinked_dir);
+        else
+                unlink_op = (new_dir == obj->my_dev->unlinked_dir
+                             && obj->variant_type == YAFFS_OBJECT_TYPE_FILE);
+
+        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 allowed.
+         *   else only proceed if the new name does not exist and if 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) {
+                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 purposes. */
+                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 limited 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 > 0) {
+                do {
+                        cache = NULL;
+
+                        /* Find the dirty cache for this object with the lowest chunk id. */
+                        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;
+        int pushout;
+
+        if (dev->param.n_caches > 0) {
+                /* Try find a non-dirty one... */
+
+                cache = yaffs_grab_chunk_worker(dev);
+
+                if (!cache) {
+                        /* They were all dirty, find the last recently used object and flush
+                         * its cache, then  find again.
+                         * NB what's here is not very accurate, we actually flush the object
+                         * the last recently used page.
+                         */
+
+                        /* With locking we can't assume we can use entry zero */
+
+                        the_obj = NULL;
+                        usage = -1;
+                        cache = NULL;
+                        pushout = -1;
+
+                        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];
+                                        pushout = i;
+                                }
+                        }
+
+                        if (!cache || cache->dirty) {
+                                /* Flush and try again */
+                                yaffs_flush_file_cache(the_obj);
+                                cache = yaffs_grab_chunk_worker(dev);
+                        }
+
+                }
+                return cache;
+        } else {
+                return NULL;
+        }
+}
+
+/* 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 > 0) {
+                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)
+{
+
+        if (dev->param.n_caches > 0) {
+                if (dev->cache_last_use < 0 || dev->cache_last_use > 100000000) {
+                        /* Reset the cache usages */
+                        int i;
+                        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)
+{
+        if (object->my_dev->param.n_caches > 0) {
+                struct yaffs_cache *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 = obj->my_dev;
+
+        yaffs_trace(YAFFS_TRACE_OS, "FreeObject %p inode %p",
+                obj, obj->my_inode);
+
+        if (!obj)
+                YBUG();
+        if (obj->parent)
+                YBUG();
+        if (!list_empty(&obj->siblings))
+                YBUG();
+
+        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)
+{
+
+        /* First off, invalidate 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 the unlinked directory so we have a record that it was deleted. */
+                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) {
+                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) {
+                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 > 0) {
+                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.-------------------*/
+
+/* AllocateEmptyObject gets us a clean Object. Tries to make allocate more if we run out */
+static struct yaffs_obj *yaffs_alloc_empty_obj(struct yaffs_dev *dev)
+{
+        struct yaffs_obj *obj = yaffs_alloc_raw_obj(dev);
+
+        if (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);
+
+        /* Now find an object value that has not already been taken
+         * by scanning the list.
+         */
+
+        int found = 0;
+        struct list_head *i;
+
+        u32 n = (u32) bucket;
+
+        /* yaffs_check_obj_hash_sane();  */
+
+        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 */
+                if (i) {
+                        in = list_entry(i, struct yaffs_obj, hash_link);
+                        if (in->obj_id == number) {
+
+                                /* Don't tell the VFS about this one 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;
+        }
+
+        if (the_obj) {
+                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 = ~0; /* max */
+                        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) {
+                obj->fake = 1;  /* it is fake so it might have no NAND presence... */
+                obj->rename_allowed = 0;        /* ... and we're not allowed to rename it... */
+                obj->unlink_allowed = 0;        /* ... or unlink it */
+                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 = strnlen(str, YAFFS_MAX_ALIAS_LENGTH);
+        new_str = kmalloc((len + 1) * sizeof(YCHAR), GFP_NOFS);
+        if (new_str) {
+                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) {
+                if (str)
+                        kfree(str);
+                return NULL;
+        }
+
+        if (in) {
+                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 the creation */
+                        yaffs_del_obj(in);
+                        in = NULL;
+                }
+
+                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 as an equivalent object */
+        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;
+        } else {
+                return NULL;
+        }
+
+}
+
+
+
+/*------------------------- Block Management and Page Allocation ----------------*/
+
+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) {
+                /* 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->block_info && dev->chunk_bits) {
+                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;
+        }
+
+        return YAFFS_FAIL;
+}
+
+static void yaffs_deinit_blocks(struct yaffs_dev *dev)
+{
+        if (dev->block_info_alt && dev->block_info)
+                vfree(dev->block_info);
+        else if (dev->block_info)
+                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 if (dev->chunk_bits)
+                kfree(dev->chunk_bits);
+        dev->chunk_bits_alt = 0;
+        dev->chunk_bits = NULL;
+}
+
+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;
+
+        /* 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 this block */
+        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);
+                }
+        }
+
+        if (erased_ok &&
+            ((yaffs_trace_mask & YAFFS_TRACE_ERASE)
+             || !yaffs_skip_verification(dev))) {
+                int i;
+                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) {
+                /* 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;
+                yaffs_clear_chunk_bits(dev, block_no);
+
+                yaffs_trace(YAFFS_TRACE_ERASE,
+                        "Erased block %d", block_no);
+        } else {
+                /* 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);
+        }
+}
+
+
+
+static int yaffs_gc_block(struct yaffs_dev *dev, int block, int whole_block)
+{
+        int old_chunk;
+        int new_chunk;
+        int mark_flash;
+        int ret_val = YAFFS_OK;
+        int i;
+        int is_checkpt_block;
+        int matching_chunk;
+        int max_copies;
+
+        int chunks_before = yaffs_get_erased_chunks(dev);
+        int chunks_after;
+
+        struct yaffs_ext_tags tags;
+
+        struct yaffs_block_info *bi = yaffs_get_block_info(dev, block);
+
+        struct yaffs_obj *object;
+
+        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;
+
+        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, __LINE__);
+
+                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)) {
+
+                                /* This page is in use and might need to be copied off */
+
+                                max_copies--;
+
+                                mark_flash = 1;
+
+                                yaffs_init_tags(&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)
+                                                matching_chunk = old_chunk;     /* Defeat the test */
+                                        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 the object */
+                                                dev->gc_cleanup_list[dev->
+                                                                     n_clean_ups]
+                                                    = tags.obj_id;
+                                                dev->n_clean_ups++;
+                                        }
+                                        mark_flash = 0;
+                                } else if (0) {
+                                        /* Todo object && object->deleted && object->n_data_chunks == 0 */
+                                        /* Deleted object header with no data chunks.
+                                         * Can be discarded and the file deleted.
+                                         */
+                                        object->hdr_chunk = 0;
+                                        yaffs_free_tnode(object->my_dev,
+                                                         object->
+                                                         variant.file_variant.
+                                                         top);
+                                        object->variant.file_variant.top = NULL;
+                                        yaffs_generic_obj_del(object);
+
+                                } 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 first
+                                                 * Also need to clean up shadowing.
+                                                 * We no longer want the shrink_header flag since its work is done
+                                                 * and if it is left in place it will mess up scanning.
+                                                 */
+
+                                                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) {
+                                                        oh->file_size =
+                                                            object->variant.
+                                                            file_variant.
+                                                            file_size;
+                                                        tags.extra_length =
+                                                            oh->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 {
+
+                                                /* Ok, 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 */
+                                                        int ok;
+                                                        ok = 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__);
+
+                        }
+                }
+
+                yaffs_release_temp_buffer(dev, buffer, __LINE__);
+
+        }
+
+        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 */
+                        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;
+}
+
+/*
+ * FindBlockForgarbageCollection is used to select 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 (we're doing a 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 selecting 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 will only accept 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.
+         * We'll only see looping 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) {
+
+                yaffs_init_tags(&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_SCANNING ||
+            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_SCANNING) {
+                        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 */
+        yaffs_init_tags(&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);
+                YBUG();
+        }
+
+        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, __LINE__);
+        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, __LINE__);
+        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 *chunk_data;
+        struct yaffs_obj_hdr *oh;
+        struct yaffs_dev *dev;
+        struct yaffs_ext_tags tags;
+        int result;
+        int alloc_failed = 0;
+
+        if (!in)
+                return;
+
+        dev = in->my_dev;
+
+        if (in->lazy_loaded && in->hdr_chunk > 0) {
+                in->lazy_loaded = 0;
+                chunk_data = yaffs_get_temp_buffer(dev, __LINE__);
+
+                result =
+                    yaffs_rd_chunk_tags_nand(dev, in->hdr_chunk, chunk_data,
+                                             &tags);
+                oh = (struct yaffs_obj_hdr *)chunk_data;
+
+                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);
+                        if (!in->variant.symlink_variant.alias)
+                                alloc_failed = 1;       /* Not returned to caller */
+                }
+
+                yaffs_release_temp_buffer(dev, chunk_data, __LINE__);
+        }
+}
+
+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 {
+                        strncpy(name, oh_name + 1, buff_size - 1);
+                }
+        } else {
+#else
+        {
+#endif
+                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 do a unicode to ascii conversion */
+                        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 {
+                        /* It is a unicode name, so save starting at the second YCHAR */
+                        *oh_name = 0;
+                        strncpy(oh_name + 1, name,
+                                      YAFFS_MAX_NAME_LENGTH - 2);
+                }
+        } else {
+#else
+        {
+#endif
+                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 result = 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;
+
+        strcpy(old_name, _Y("silly old name"));
+
+        if (!in->fake || in == dev->root_dir ||
+            force || xmod) {
+
+                yaffs_check_gc(dev, 0);
+                yaffs_check_obj_details_loaded(in);
+
+                buffer = yaffs_get_temp_buffer(in->my_dev, __LINE__);
+                oh = (struct yaffs_obj_hdr *)buffer;
+
+                prev_chunk_id = in->hdr_chunk;
+
+                if (prev_chunk_id > 0) {
+                        result = 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:
+                        oh->file_size =
+                            (oh->parent_obj_id == YAFFS_OBJECTID_DELETED
+                             || oh->parent_obj_id ==
+                             YAFFS_OBJECTID_UNLINKED) ? 0 : in->
+                            variant.file_variant.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");
+                        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 */
+                yaffs_init_tags(&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_length = oh->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 (new_chunk_id >= 0) {
+
+                        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;
+                        }
+
+                }
+
+                ret_val = new_chunk_id;
+
+        }
+
+        if (buffer)
+                yaffs_release_temp_buffer(dev, buffer, __LINE__);
+
+        return ret_val;
+}
+
+/*--------------------- 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) {
+                /* chunk = offset / dev->data_bytes_per_chunk + 1; */
+                /* start = offset % dev->data_bytes_per_chunk; */
+                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, __LINE__);
+                                yaffs_rd_data_obj(in, chunk, local_buffer);
+
+                                memcpy(buffer, &local_buffer[start], n_copy);
+
+                                yaffs_release_temp_buffer(dev, local_buffer,
+                                                          __LINE__);
+                        }
+
+                } else {
+
+                        /* A full chunk. Read directly into the supplied 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_trhrough)
+{
+
+        int chunk;
+        u32 start;
+        int n_copy;
+        int n = n_bytes;
+        int n_done = 0;
+        int n_writeback;
+        int start_write = offset;
+        int chunk_written = 0;
+        u32 n_bytes_read;
+        u32 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 (chunk * dev->data_bytes_per_chunk + start != offset ||
+                    start >= dev->data_bytes_per_chunk) {
+                        yaffs_trace(YAFFS_TRACE_ERROR,
+                                "AddrToChunk of offset %d gives chunk %d start %d",
+                                (int)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 folks, to 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 = ((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)
+                                YBUG();
+
+                } 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_trhrough) {
+                                                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 the write */
+                                }
+                        } else {
+                                /* An incomplete start or end chunk (or maybe both start and end chunk)
+                                 * Read into the local buffer then copy, then copy over and write back.
+                                 */
+
+                                u8 *local_buffer =
+                                    yaffs_get_temp_buffer(dev, __LINE__);
+
+                                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,
+                                                          __LINE__);
+
+                        }
+
+                } else {
+                        /* A full chunk. Write directly from the supplied 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_trhrough)
+{
+        yaffs2_handle_hole(in, offset);
+        return yaffs_do_file_wr(in, buffer, offset, n_bytes, write_trhrough);
+}
+
+/* ---------------------- File resizing stuff ------------------ */
+
+static void yaffs_prune_chunks(struct yaffs_obj *in, int new_size)
+{
+
+        struct yaffs_dev *dev = in->my_dev;
+        int old_size = in->variant.file_variant.file_size;
+
+        int last_del = 1 + (old_size - 1) / dev->data_bytes_per_chunk;
+
+        int start_del = 1 + (new_size + dev->data_bytes_per_chunk - 1) /
+            dev->data_bytes_per_chunk;
+        int i;
+        int chunk_id;
+
+        /* 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 > 0) {
+                        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, __LINE__);
+
+                /* 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, __LINE__);
+        }
+
+        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;
+        int 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)
+{
+        int ret_val;
+        if (in->dirty) {
+                yaffs_flush_file_cache(in);
+                if (data_sync)  /* Only sync data */
+                        ret_val = YAFFS_OK;
+                else {
+                        if (update_time)
+                                yaffs_load_current_time(in, 0, 0);
+
+                        ret_val = (yaffs_update_oh(in, NULL, 0, 0, 0, NULL) >=
+                                   0) ? YAFFS_OK : YAFFS_FAIL;
+                }
+        } else {
+                ret_val = YAFFS_OK;
+        }
+
+        return ret_val;
+
+}
+
+
+/* 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)
+{
+        if (in->variant.symlink_variant.alias)
+                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 assocaited 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->my_inode)
+                del_now = 1;
+
+        if (obj)
+                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 can work)
+                 * - 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)
+                YBUG();
+        if (!new_dir || new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
+                YBUG();
+
+        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 && 
+                strcmp(old_name, new_name) == 0)
+                force = 1;
+#endif
+
+        if (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 do the handling for 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 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 YAFFS1 forward scanning case
+                 * For YAFFS1 we always do the deletion
+                 */
+
+        } else {
+                /* 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 for this file */
+
+}
+
+void yaffs_link_fixup(struct yaffs_dev *dev, struct yaffs_obj *hard_list)
+{
+        struct yaffs_obj *hl;
+        struct yaffs_obj *in;
+
+        while (hard_list) {
+                hl = hard_list;
+                hard_list = (struct yaffs_obj *)(hard_list->hard_links.next);
+
+                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) {
+                if (i) {
+                        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) {
+                if (i) {
+                        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) {
+                        if (lh) {
+                                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)
+                YBUG();
+
+        list_for_each_safe(lh, n, &dir->variant.dir_variant.children) {
+                if (lh) {
+                        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);
+
+                        /* Need to use UnlinkObject since Delete would not handle
+                         * hardlinked objects correctly.
+                         */
+                        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"
+                        );
+                YBUG();
+                return NULL;
+        }
+        if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
+                yaffs_trace(YAFFS_TRACE_ALWAYS,
+                        "tragedy: yaffs_find_by_name: non-directory"
+                        );
+                YBUG();
+        }
+
+        sum = yaffs_calc_name_sum(name);
+
+        list_for_each(i, &directory->variant.dir_variant.children) {
+                if (i) {
+                        l = list_entry(i, struct yaffs_obj, siblings);
+
+                        if (l->parent != directory)
+                                YBUG();
+
+                        yaffs_check_obj_details_loaded(l);
+
+                        /* Special case for lost-n-found */
+                        if (l->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
+                                if (!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 (strncmp
+                                    (name, buffer, YAFFS_MAX_NAME_LENGTH) == 0)
+                                        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) {
+                /* We want the object id of the equivalent object, not this one */
+                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 (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 */
+                strcpy(local_name, YAFFS_LOSTNFOUND_PREFIX);
+                strcat(local_name, x);
+                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) {
+                strncpy(name, YAFFS_LOSTNFOUND_NAME, buffer_size - 1);
+        }
+#ifndef CONFIG_YAFFS_NO_SHORT_NAMES
+        else if (obj->short_name[0]) {
+                strcpy(name, obj->short_name);
+        }
+#endif
+        else if (obj->hdr_chunk > 0) {
+                int result;
+                u8 *buffer = yaffs_get_temp_buffer(obj->my_dev, __LINE__);
+
+                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) {
+                        result = 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, __LINE__);
+        }
+
+        yaffs_fix_null_name(obj, name, buffer_size);
+
+        return strnlen(name, YAFFS_MAX_NAME_LENGTH);
+}
+
+int 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 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;
+        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;
+
+#ifdef CONFIG_YAFFS_YAFFS2
+
+        /* 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;
+#endif
+
+        /* 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 and 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;
+        }
+
+        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;
+        }
+
+        if (dev->is_mounted) {
+                yaffs_trace(YAFFS_TRACE_ALWAYS, "device already mounted");
+                return YAFFS_FAIL;
+        }
+
+        /* Finished with most checks. One or two more 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;
+        }
+
+        /* OK, we've finished verifying the device, lets 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) {
+                /* 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
+                                 * and 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_retired_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);
+                if (dev->param.n_caches > 0 && dev->cache) {
+
+                        for (i = 0; i < dev->param.n_caches; i++) {
+                                if (dev->cache[i].data)
+                                        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 the number of dirty chunks in the cache and subtract those */
+
+        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 we figure out how much to reserve for the checkpoint 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;
+
+}