1 files changed, 498 insertions, 0 deletions

diff --git a/fs/hfs/bnode.c b/fs/hfs/bnode.c
new file mode 100644
index 0000000..6ad1211
--- /dev/null
+++ b/fs/hfs/bnode.c
@@ -0,0 +1,498 @@
+/*
+ *  linux/fs/hfs/bnode.c
+ *
+ * Copyright (C) 2001
+ * Brad Boyer (flar@allandria.com)
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ *
+ * Handle basic btree node operations
+ */
+
+#include <linux/pagemap.h>
+#include <linux/swap.h>
+
+#include "btree.h"
+
+#define REF_PAGES	0
+
+void hfs_bnode_read(struct hfs_bnode *node, void *buf,
+		int off, int len)
+{
+	struct page *page;
+
+	off += node->page_offset;
+	page = node->page[0];
+
+	memcpy(buf, kmap(page) + off, len);
+	kunmap(page);
+}
+
+u16 hfs_bnode_read_u16(struct hfs_bnode *node, int off)
+{
+	__be16 data;
+	// optimize later...
+	hfs_bnode_read(node, &data, off, 2);
+	return be16_to_cpu(data);
+}
+
+u8 hfs_bnode_read_u8(struct hfs_bnode *node, int off)
+{
+	u8 data;
+	// optimize later...
+	hfs_bnode_read(node, &data, off, 1);
+	return data;
+}
+
+void hfs_bnode_read_key(struct hfs_bnode *node, void *key, int off)
+{
+	struct hfs_btree *tree;
+	int key_len;
+
+	tree = node->tree;
+	if (node->type == HFS_NODE_LEAF ||
+	    tree->attributes & HFS_TREE_VARIDXKEYS)
+		key_len = hfs_bnode_read_u8(node, off) + 1;
+	else
+		key_len = tree->max_key_len + 1;
+
+	hfs_bnode_read(node, key, off, key_len);
+}
+
+void hfs_bnode_write(struct hfs_bnode *node, void *buf, int off, int len)
+{
+	struct page *page;
+
+	off += node->page_offset;
+	page = node->page[0];
+
+	memcpy(kmap(page) + off, buf, len);
+	kunmap(page);
+	set_page_dirty(page);
+}
+
+void hfs_bnode_write_u16(struct hfs_bnode *node, int off, u16 data)
+{
+	__be16 v = cpu_to_be16(data);
+	// optimize later...
+	hfs_bnode_write(node, &v, off, 2);
+}
+
+void hfs_bnode_write_u8(struct hfs_bnode *node, int off, u8 data)
+{
+	// optimize later...
+	hfs_bnode_write(node, &data, off, 1);
+}
+
+void hfs_bnode_clear(struct hfs_bnode *node, int off, int len)
+{
+	struct page *page;
+
+	off += node->page_offset;
+	page = node->page[0];
+
+	memset(kmap(page) + off, 0, len);
+	kunmap(page);
+	set_page_dirty(page);
+}
+
+void hfs_bnode_copy(struct hfs_bnode *dst_node, int dst,
+		struct hfs_bnode *src_node, int src, int len)
+{
+	struct hfs_btree *tree;
+	struct page *src_page, *dst_page;
+
+	dprint(DBG_BNODE_MOD, "copybytes: %u,%u,%u\n", dst, src, len);
+	if (!len)
+		return;
+	tree = src_node->tree;
+	src += src_node->page_offset;
+	dst += dst_node->page_offset;
+	src_page = src_node->page[0];
+	dst_page = dst_node->page[0];
+
+	memcpy(kmap(dst_page) + dst, kmap(src_page) + src, len);
+	kunmap(src_page);
+	kunmap(dst_page);
+	set_page_dirty(dst_page);
+}
+
+void hfs_bnode_move(struct hfs_bnode *node, int dst, int src, int len)
+{
+	struct page *page;
+	void *ptr;
+
+	dprint(DBG_BNODE_MOD, "movebytes: %u,%u,%u\n", dst, src, len);
+	if (!len)
+		return;
+	src += node->page_offset;
+	dst += node->page_offset;
+	page = node->page[0];
+	ptr = kmap(page);
+	memmove(ptr + dst, ptr + src, len);
+	kunmap(page);
+	set_page_dirty(page);
+}
+
+void hfs_bnode_dump(struct hfs_bnode *node)
+{
+	struct hfs_bnode_desc desc;
+	__be32 cnid;
+	int i, off, key_off;
+
+	dprint(DBG_BNODE_MOD, "bnode: %d\n", node->this);
+	hfs_bnode_read(node, &desc, 0, sizeof(desc));
+	dprint(DBG_BNODE_MOD, "%d, %d, %d, %d, %d\n",
+		be32_to_cpu(desc.next), be32_to_cpu(desc.prev),
+		desc.type, desc.height, be16_to_cpu(desc.num_recs));
+
+	off = node->tree->node_size - 2;
+	for (i = be16_to_cpu(desc.num_recs); i >= 0; off -= 2, i--) {
+		key_off = hfs_bnode_read_u16(node, off);
+		dprint(DBG_BNODE_MOD, " %d", key_off);
+		if (i && node->type == HFS_NODE_INDEX) {
+			int tmp;
+
+			if (node->tree->attributes & HFS_TREE_VARIDXKEYS)
+				tmp = (hfs_bnode_read_u8(node, key_off) | 1) + 1;
+			else
+				tmp = node->tree->max_key_len + 1;
+			dprint(DBG_BNODE_MOD, " (%d,%d", tmp, hfs_bnode_read_u8(node, key_off));
+			hfs_bnode_read(node, &cnid, key_off + tmp, 4);
+			dprint(DBG_BNODE_MOD, ",%d)", be32_to_cpu(cnid));
+		} else if (i && node->type == HFS_NODE_LEAF) {
+			int tmp;
+
+			tmp = hfs_bnode_read_u8(node, key_off);
+			dprint(DBG_BNODE_MOD, " (%d)", tmp);
+		}
+	}
+	dprint(DBG_BNODE_MOD, "\n");
+}
+
+void hfs_bnode_unlink(struct hfs_bnode *node)
+{
+	struct hfs_btree *tree;
+	struct hfs_bnode *tmp;
+	__be32 cnid;
+
+	tree = node->tree;
+	if (node->prev) {
+		tmp = hfs_bnode_find(tree, node->prev);
+		if (IS_ERR(tmp))
+			return;
+		tmp->next = node->next;
+		cnid = cpu_to_be32(tmp->next);
+		hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
+		hfs_bnode_put(tmp);
+	} else if (node->type == HFS_NODE_LEAF)
+		tree->leaf_head = node->next;
+
+	if (node->next) {
+		tmp = hfs_bnode_find(tree, node->next);
+		if (IS_ERR(tmp))
+			return;
+		tmp->prev = node->prev;
+		cnid = cpu_to_be32(tmp->prev);
+		hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, prev), 4);
+		hfs_bnode_put(tmp);
+	} else if (node->type == HFS_NODE_LEAF)
+		tree->leaf_tail = node->prev;
+
+	// move down?
+	if (!node->prev && !node->next) {
+		printk("hfs_btree_del_level\n");
+	}
+	if (!node->parent) {
+		tree->root = 0;
+		tree->depth = 0;
+	}
+	set_bit(HFS_BNODE_DELETED, &node->flags);
+}
+
+static inline int hfs_bnode_hash(u32 num)
+{
+	num = (num >> 16) + num;
+	num += num >> 8;
+	return num & (NODE_HASH_SIZE - 1);
+}
+
+struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *tree, u32 cnid)
+{
+	struct hfs_bnode *node;
+
+	if (cnid >= tree->node_count) {
+		printk("HFS: request for non-existent node %d in B*Tree\n", cnid);
+		return NULL;
+	}
+
+	for (node = tree->node_hash[hfs_bnode_hash(cnid)];
+	     node; node = node->next_hash) {
+		if (node->this == cnid) {
+			return node;
+		}
+	}
+	return NULL;
+}
+
+static struct hfs_bnode *__hfs_bnode_create(struct hfs_btree *tree, u32 cnid)
+{
+	struct super_block *sb;
+	struct hfs_bnode *node, *node2;
+	struct address_space *mapping;
+	struct page *page;
+	int size, block, i, hash;
+	loff_t off;
+
+	if (cnid >= tree->node_count) {
+		printk("HFS: request for non-existent node %d in B*Tree\n", cnid);
+		return NULL;
+	}
+
+	sb = tree->inode->i_sb;
+	size = sizeof(struct hfs_bnode) + tree->pages_per_bnode *
+		sizeof(struct page *);
+	node = kmalloc(size, GFP_KERNEL);
+	if (!node)
+		return NULL;
+	memset(node, 0, size);
+	node->tree = tree;
+	node->this = cnid;
+	set_bit(HFS_BNODE_NEW, &node->flags);
+	atomic_set(&node->refcnt, 1);
+	dprint(DBG_BNODE_REFS, "new_node(%d:%d): 1\n",
+	       node->tree->cnid, node->this);
+	init_waitqueue_head(&node->lock_wq);
+	spin_lock(&tree->hash_lock);
+	node2 = hfs_bnode_findhash(tree, cnid);
+	if (!node2) {
+		hash = hfs_bnode_hash(cnid);
+		node->next_hash = tree->node_hash[hash];
+		tree->node_hash[hash] = node;
+		tree->node_hash_cnt++;
+	} else {
+		spin_unlock(&tree->hash_lock);
+		kfree(node);
+		wait_event(node2->lock_wq, !test_bit(HFS_BNODE_NEW, &node2->flags));
+		return node2;
+	}
+	spin_unlock(&tree->hash_lock);
+
+	mapping = tree->inode->i_mapping;
+	off = (loff_t)cnid * tree->node_size;
+	block = off >> PAGE_CACHE_SHIFT;
+	node->page_offset = off & ~PAGE_CACHE_MASK;
+	for (i = 0; i < tree->pages_per_bnode; i++) {
+		page = read_cache_page(mapping, block++, (filler_t *)mapping->a_ops->readpage, NULL);
+		if (IS_ERR(page))
+			goto fail;
+		if (PageError(page)) {
+			page_cache_release(page);
+			goto fail;
+		}
+#if !REF_PAGES
+		page_cache_release(page);
+#endif
+		node->page[i] = page;
+	}
+
+	return node;
+fail:
+	set_bit(HFS_BNODE_ERROR, &node->flags);
+	return node;
+}
+
+void hfs_bnode_unhash(struct hfs_bnode *node)
+{
+	struct hfs_bnode **p;
+
+	dprint(DBG_BNODE_REFS, "remove_node(%d:%d): %d\n",
+		node->tree->cnid, node->this, atomic_read(&node->refcnt));
+	for (p = &node->tree->node_hash[hfs_bnode_hash(node->this)];
+	     *p && *p != node; p = &(*p)->next_hash)
+		;
+	if (!*p)
+		BUG();
+	*p = node->next_hash;
+	node->tree->node_hash_cnt--;
+}
+
+/* Load a particular node out of a tree */
+struct hfs_bnode *hfs_bnode_find(struct hfs_btree *tree, u32 num)
+{
+	struct hfs_bnode *node;
+	struct hfs_bnode_desc *desc;
+	int i, rec_off, off, next_off;
+	int entry_size, key_size;
+
+	spin_lock(&tree->hash_lock);
+	node = hfs_bnode_findhash(tree, num);
+	if (node) {
+		hfs_bnode_get(node);
+		spin_unlock(&tree->hash_lock);
+		wait_event(node->lock_wq, !test_bit(HFS_BNODE_NEW, &node->flags));
+		if (test_bit(HFS_BNODE_ERROR, &node->flags))
+			goto node_error;
+		return node;
+	}
+	spin_unlock(&tree->hash_lock);
+	node = __hfs_bnode_create(tree, num);
+	if (!node)
+		return ERR_PTR(-ENOMEM);
+	if (test_bit(HFS_BNODE_ERROR, &node->flags))
+		goto node_error;
+	if (!test_bit(HFS_BNODE_NEW, &node->flags))
+		return node;
+
+	desc = (struct hfs_bnode_desc *)(kmap(node->page[0]) + node->page_offset);
+	node->prev = be32_to_cpu(desc->prev);
+	node->next = be32_to_cpu(desc->next);
+	node->num_recs = be16_to_cpu(desc->num_recs);
+	node->type = desc->type;
+	node->height = desc->height;
+	kunmap(node->page[0]);
+
+	switch (node->type) {
+	case HFS_NODE_HEADER:
+	case HFS_NODE_MAP:
+		if (node->height != 0)
+			goto node_error;
+		break;
+	case HFS_NODE_LEAF:
+		if (node->height != 1)
+			goto node_error;
+		break;
+	case HFS_NODE_INDEX:
+		if (node->height <= 1 || node->height > tree->depth)
+			goto node_error;
+		break;
+	default:
+		goto node_error;
+	}
+
+	rec_off = tree->node_size - 2;
+	off = hfs_bnode_read_u16(node, rec_off);
+	if (off != sizeof(struct hfs_bnode_desc))
+		goto node_error;
+	for (i = 1; i <= node->num_recs; off = next_off, i++) {
+		rec_off -= 2;
+		next_off = hfs_bnode_read_u16(node, rec_off);
+		if (next_off <= off ||
+		    next_off > tree->node_size ||
+		    next_off & 1)
+			goto node_error;
+		entry_size = next_off - off;
+		if (node->type != HFS_NODE_INDEX &&
+		    node->type != HFS_NODE_LEAF)
+			continue;
+		key_size = hfs_bnode_read_u8(node, off) + 1;
+		if (key_size >= entry_size /*|| key_size & 1*/)
+			goto node_error;
+	}
+	clear_bit(HFS_BNODE_NEW, &node->flags);
+	wake_up(&node->lock_wq);
+	return node;
+
+node_error:
+	set_bit(HFS_BNODE_ERROR, &node->flags);
+	clear_bit(HFS_BNODE_NEW, &node->flags);
+	wake_up(&node->lock_wq);
+	hfs_bnode_put(node);
+	return ERR_PTR(-EIO);
+}
+
+void hfs_bnode_free(struct hfs_bnode *node)
+{
+	//int i;
+
+	//for (i = 0; i < node->tree->pages_per_bnode; i++)
+	//	if (node->page[i])
+	//		page_cache_release(node->page[i]);
+	kfree(node);
+}
+
+struct hfs_bnode *hfs_bnode_create(struct hfs_btree *tree, u32 num)
+{
+	struct hfs_bnode *node;
+	struct page **pagep;
+	int i;
+
+	spin_lock(&tree->hash_lock);
+	node = hfs_bnode_findhash(tree, num);
+	spin_unlock(&tree->hash_lock);
+	if (node)
+		BUG();
+	node = __hfs_bnode_create(tree, num);
+	if (!node)
+		return ERR_PTR(-ENOMEM);
+	if (test_bit(HFS_BNODE_ERROR, &node->flags)) {
+		hfs_bnode_put(node);
+		return ERR_PTR(-EIO);
+	}
+
+	pagep = node->page;
+	memset(kmap(*pagep) + node->page_offset, 0,
+	       min((int)PAGE_CACHE_SIZE, (int)tree->node_size));
+	set_page_dirty(*pagep);
+	kunmap(*pagep);
+	for (i = 1; i < tree->pages_per_bnode; i++) {
+		memset(kmap(*++pagep), 0, PAGE_CACHE_SIZE);
+		set_page_dirty(*pagep);
+		kunmap(*pagep);
+	}
+	clear_bit(HFS_BNODE_NEW, &node->flags);
+	wake_up(&node->lock_wq);
+
+	return node;
+}
+
+void hfs_bnode_get(struct hfs_bnode *node)
+{
+	if (node) {
+		atomic_inc(&node->refcnt);
+#if REF_PAGES
+		{
+		int i;
+		for (i = 0; i < node->tree->pages_per_bnode; i++)
+			get_page(node->page[i]);
+		}
+#endif
+		dprint(DBG_BNODE_REFS, "get_node(%d:%d): %d\n",
+		       node->tree->cnid, node->this, atomic_read(&node->refcnt));
+	}
+}
+
+/* Dispose of resources used by a node */
+void hfs_bnode_put(struct hfs_bnode *node)
+{
+	if (node) {
+		struct hfs_btree *tree = node->tree;
+		int i;
+
+		dprint(DBG_BNODE_REFS, "put_node(%d:%d): %d\n",
+		       node->tree->cnid, node->this, atomic_read(&node->refcnt));
+		if (!atomic_read(&node->refcnt))
+			BUG();
+		if (!atomic_dec_and_lock(&node->refcnt, &tree->hash_lock)) {
+#if REF_PAGES
+			for (i = 0; i < tree->pages_per_bnode; i++)
+				put_page(node->page[i]);
+#endif
+			return;
+		}
+		for (i = 0; i < tree->pages_per_bnode; i++) {
+			mark_page_accessed(node->page[i]);
+#if REF_PAGES
+			put_page(node->page[i]);
+#endif
+		}
+
+		if (test_bit(HFS_BNODE_DELETED, &node->flags)) {
+			hfs_bnode_unhash(node);
+			spin_unlock(&tree->hash_lock);
+			hfs_bmap_free(node);
+			hfs_bnode_free(node);
+			return;
+		}
+		spin_unlock(&tree->hash_lock);
+	}
+}