+ 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 = dev->cache[0].object;
+ 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+ * ie the short cache for this page is no longer valid.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;