1 files changed, 534 insertions, 0 deletions

diff --git a/fs/hfsplus/brec.c b/fs/hfsplus/brec.c
new file mode 100644
index 0000000000..1918544a78
--- /dev/null
+++ b/fs/hfsplus/brec.c
@@ -0,0 +1,534 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/hfsplus/brec.c
+ *
+ * Copyright (C) 2001
+ * Brad Boyer (flar@allandria.com)
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ *
+ * Handle individual btree records
+ */
+
+#include "hfsplus_fs.h"
+#include "hfsplus_raw.h"
+
+static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd);
+static int hfs_brec_update_parent(struct hfs_find_data *fd);
+static int hfs_btree_inc_height(struct hfs_btree *);
+
+/* Get the length and offset of the given record in the given node */
+u16 hfs_brec_lenoff(struct hfs_bnode *node, u16 rec, u16 *off)
+{
+	__be16 retval[2];
+	u16 dataoff;
+
+	dataoff = node->tree->node_size - (rec + 2) * 2;
+	hfs_bnode_read(node, retval, dataoff, 4);
+	*off = be16_to_cpu(retval[1]);
+	return be16_to_cpu(retval[0]) - *off;
+}
+
+/* Get the length of the key from a keyed record */
+u16 hfs_brec_keylen(struct hfs_bnode *node, u16 rec)
+{
+	u16 retval, recoff;
+
+	if (node->type != HFS_NODE_INDEX && node->type != HFS_NODE_LEAF)
+		return 0;
+
+	if ((node->type == HFS_NODE_INDEX) &&
+	   !(node->tree->attributes & HFS_TREE_VARIDXKEYS) &&
+	   (node->tree->cnid != HFSPLUS_ATTR_CNID)) {
+		retval = node->tree->max_key_len + 2;
+	} else {
+		recoff = hfs_bnode_read_u16(node,
+			node->tree->node_size - (rec + 1) * 2);
+		if (!recoff)
+			return 0;
+		if (recoff > node->tree->node_size - 2) {
+			pr_err("recoff %d too large\n", recoff);
+			return 0;
+		}
+
+		retval = hfs_bnode_read_u16(node, recoff) + 2;
+		if (retval > node->tree->max_key_len + 2) {
+			pr_err("keylen %d too large\n",
+				retval);
+			retval = 0;
+		}
+	}
+	return retval;
+}
+
+int hfs_brec_insert(struct hfs_find_data *fd, void *entry, int entry_len)
+{
+	struct hfs_btree *tree;
+	struct hfs_bnode *node, *new_node;
+	int size, key_len, rec;
+	int data_off, end_off;
+	int idx_rec_off, data_rec_off, end_rec_off;
+	__be32 cnid;
+
+	tree = fd->tree;
+	if (!fd->bnode) {
+		if (!tree->root)
+			hfs_btree_inc_height(tree);
+		node = hfs_bnode_find(tree, tree->leaf_head);
+		if (IS_ERR(node))
+			return PTR_ERR(node);
+		fd->bnode = node;
+		fd->record = -1;
+	}
+	new_node = NULL;
+	key_len = be16_to_cpu(fd->search_key->key_len) + 2;
+again:
+	/* new record idx and complete record size */
+	rec = fd->record + 1;
+	size = key_len + entry_len;
+
+	node = fd->bnode;
+	hfs_bnode_dump(node);
+	/* get last offset */
+	end_rec_off = tree->node_size - (node->num_recs + 1) * 2;
+	end_off = hfs_bnode_read_u16(node, end_rec_off);
+	end_rec_off -= 2;
+	hfs_dbg(BNODE_MOD, "insert_rec: %d, %d, %d, %d\n",
+		rec, size, end_off, end_rec_off);
+	if (size > end_rec_off - end_off) {
+		if (new_node)
+			panic("not enough room!\n");
+		new_node = hfs_bnode_split(fd);
+		if (IS_ERR(new_node))
+			return PTR_ERR(new_node);
+		goto again;
+	}
+	if (node->type == HFS_NODE_LEAF) {
+		tree->leaf_count++;
+		mark_inode_dirty(tree->inode);
+	}
+	node->num_recs++;
+	/* write new last offset */
+	hfs_bnode_write_u16(node,
+		offsetof(struct hfs_bnode_desc, num_recs),
+		node->num_recs);
+	hfs_bnode_write_u16(node, end_rec_off, end_off + size);
+	data_off = end_off;
+	data_rec_off = end_rec_off + 2;
+	idx_rec_off = tree->node_size - (rec + 1) * 2;
+	if (idx_rec_off == data_rec_off)
+		goto skip;
+	/* move all following entries */
+	do {
+		data_off = hfs_bnode_read_u16(node, data_rec_off + 2);
+		hfs_bnode_write_u16(node, data_rec_off, data_off + size);
+		data_rec_off += 2;
+	} while (data_rec_off < idx_rec_off);
+
+	/* move data away */
+	hfs_bnode_move(node, data_off + size, data_off,
+		       end_off - data_off);
+
+skip:
+	hfs_bnode_write(node, fd->search_key, data_off, key_len);
+	hfs_bnode_write(node, entry, data_off + key_len, entry_len);
+	hfs_bnode_dump(node);
+
+	/*
+	 * update parent key if we inserted a key
+	 * at the start of the node and it is not the new node
+	 */
+	if (!rec && new_node != node) {
+		hfs_bnode_read_key(node, fd->search_key, data_off + size);
+		hfs_brec_update_parent(fd);
+	}
+
+	if (new_node) {
+		hfs_bnode_put(fd->bnode);
+		if (!new_node->parent) {
+			hfs_btree_inc_height(tree);
+			new_node->parent = tree->root;
+		}
+		fd->bnode = hfs_bnode_find(tree, new_node->parent);
+
+		/* create index data entry */
+		cnid = cpu_to_be32(new_node->this);
+		entry = &cnid;
+		entry_len = sizeof(cnid);
+
+		/* get index key */
+		hfs_bnode_read_key(new_node, fd->search_key, 14);
+		__hfs_brec_find(fd->bnode, fd, hfs_find_rec_by_key);
+
+		hfs_bnode_put(new_node);
+		new_node = NULL;
+
+		if ((tree->attributes & HFS_TREE_VARIDXKEYS) ||
+				(tree->cnid == HFSPLUS_ATTR_CNID))
+			key_len = be16_to_cpu(fd->search_key->key_len) + 2;
+		else {
+			fd->search_key->key_len =
+				cpu_to_be16(tree->max_key_len);
+			key_len = tree->max_key_len + 2;
+		}
+		goto again;
+	}
+
+	return 0;
+}
+
+int hfs_brec_remove(struct hfs_find_data *fd)
+{
+	struct hfs_btree *tree;
+	struct hfs_bnode *node, *parent;
+	int end_off, rec_off, data_off, size;
+
+	tree = fd->tree;
+	node = fd->bnode;
+again:
+	rec_off = tree->node_size - (fd->record + 2) * 2;
+	end_off = tree->node_size - (node->num_recs + 1) * 2;
+
+	if (node->type == HFS_NODE_LEAF) {
+		tree->leaf_count--;
+		mark_inode_dirty(tree->inode);
+	}
+	hfs_bnode_dump(node);
+	hfs_dbg(BNODE_MOD, "remove_rec: %d, %d\n",
+		fd->record, fd->keylength + fd->entrylength);
+	if (!--node->num_recs) {
+		hfs_bnode_unlink(node);
+		if (!node->parent)
+			return 0;
+		parent = hfs_bnode_find(tree, node->parent);
+		if (IS_ERR(parent))
+			return PTR_ERR(parent);
+		hfs_bnode_put(node);
+		node = fd->bnode = parent;
+
+		__hfs_brec_find(node, fd, hfs_find_rec_by_key);
+		goto again;
+	}
+	hfs_bnode_write_u16(node,
+		offsetof(struct hfs_bnode_desc, num_recs),
+		node->num_recs);
+
+	if (rec_off == end_off)
+		goto skip;
+	size = fd->keylength + fd->entrylength;
+
+	do {
+		data_off = hfs_bnode_read_u16(node, rec_off);
+		hfs_bnode_write_u16(node, rec_off + 2, data_off - size);
+		rec_off -= 2;
+	} while (rec_off >= end_off);
+
+	/* fill hole */
+	hfs_bnode_move(node, fd->keyoffset, fd->keyoffset + size,
+		       data_off - fd->keyoffset - size);
+skip:
+	hfs_bnode_dump(node);
+	if (!fd->record)
+		hfs_brec_update_parent(fd);
+	return 0;
+}
+
+static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd)
+{
+	struct hfs_btree *tree;
+	struct hfs_bnode *node, *new_node, *next_node;
+	struct hfs_bnode_desc node_desc;
+	int num_recs, new_rec_off, new_off, old_rec_off;
+	int data_start, data_end, size;
+
+	tree = fd->tree;
+	node = fd->bnode;
+	new_node = hfs_bmap_alloc(tree);
+	if (IS_ERR(new_node))
+		return new_node;
+	hfs_bnode_get(node);
+	hfs_dbg(BNODE_MOD, "split_nodes: %d - %d - %d\n",
+		node->this, new_node->this, node->next);
+	new_node->next = node->next;
+	new_node->prev = node->this;
+	new_node->parent = node->parent;
+	new_node->type = node->type;
+	new_node->height = node->height;
+
+	if (node->next)
+		next_node = hfs_bnode_find(tree, node->next);
+	else
+		next_node = NULL;
+
+	if (IS_ERR(next_node)) {
+		hfs_bnode_put(node);
+		hfs_bnode_put(new_node);
+		return next_node;
+	}
+
+	size = tree->node_size / 2 - node->num_recs * 2 - 14;
+	old_rec_off = tree->node_size - 4;
+	num_recs = 1;
+	for (;;) {
+		data_start = hfs_bnode_read_u16(node, old_rec_off);
+		if (data_start > size)
+			break;
+		old_rec_off -= 2;
+		if (++num_recs < node->num_recs)
+			continue;
+		/* panic? */
+		hfs_bnode_put(node);
+		hfs_bnode_put(new_node);
+		if (next_node)
+			hfs_bnode_put(next_node);
+		return ERR_PTR(-ENOSPC);
+	}
+
+	if (fd->record + 1 < num_recs) {
+		/* new record is in the lower half,
+		 * so leave some more space there
+		 */
+		old_rec_off += 2;
+		num_recs--;
+		data_start = hfs_bnode_read_u16(node, old_rec_off);
+	} else {
+		hfs_bnode_put(node);
+		hfs_bnode_get(new_node);
+		fd->bnode = new_node;
+		fd->record -= num_recs;
+		fd->keyoffset -= data_start - 14;
+		fd->entryoffset -= data_start - 14;
+	}
+	new_node->num_recs = node->num_recs - num_recs;
+	node->num_recs = num_recs;
+
+	new_rec_off = tree->node_size - 2;
+	new_off = 14;
+	size = data_start - new_off;
+	num_recs = new_node->num_recs;
+	data_end = data_start;
+	while (num_recs) {
+		hfs_bnode_write_u16(new_node, new_rec_off, new_off);
+		old_rec_off -= 2;
+		new_rec_off -= 2;
+		data_end = hfs_bnode_read_u16(node, old_rec_off);
+		new_off = data_end - size;
+		num_recs--;
+	}
+	hfs_bnode_write_u16(new_node, new_rec_off, new_off);
+	hfs_bnode_copy(new_node, 14, node, data_start, data_end - data_start);
+
+	/* update new bnode header */
+	node_desc.next = cpu_to_be32(new_node->next);
+	node_desc.prev = cpu_to_be32(new_node->prev);
+	node_desc.type = new_node->type;
+	node_desc.height = new_node->height;
+	node_desc.num_recs = cpu_to_be16(new_node->num_recs);
+	node_desc.reserved = 0;
+	hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
+
+	/* update previous bnode header */
+	node->next = new_node->this;
+	hfs_bnode_read(node, &node_desc, 0, sizeof(node_desc));
+	node_desc.next = cpu_to_be32(node->next);
+	node_desc.num_recs = cpu_to_be16(node->num_recs);
+	hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc));
+
+	/* update next bnode header */
+	if (next_node) {
+		next_node->prev = new_node->this;
+		hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc));
+		node_desc.prev = cpu_to_be32(next_node->prev);
+		hfs_bnode_write(next_node, &node_desc, 0, sizeof(node_desc));
+		hfs_bnode_put(next_node);
+	} else if (node->this == tree->leaf_tail) {
+		/* if there is no next node, this might be the new tail */
+		tree->leaf_tail = new_node->this;
+		mark_inode_dirty(tree->inode);
+	}
+
+	hfs_bnode_dump(node);
+	hfs_bnode_dump(new_node);
+	hfs_bnode_put(node);
+
+	return new_node;
+}
+
+static int hfs_brec_update_parent(struct hfs_find_data *fd)
+{
+	struct hfs_btree *tree;
+	struct hfs_bnode *node, *new_node, *parent;
+	int newkeylen, diff;
+	int rec, rec_off, end_rec_off;
+	int start_off, end_off;
+
+	tree = fd->tree;
+	node = fd->bnode;
+	new_node = NULL;
+	if (!node->parent)
+		return 0;
+
+again:
+	parent = hfs_bnode_find(tree, node->parent);
+	if (IS_ERR(parent))
+		return PTR_ERR(parent);
+	__hfs_brec_find(parent, fd, hfs_find_rec_by_key);
+	if (fd->record < 0)
+		return -ENOENT;
+	hfs_bnode_dump(parent);
+	rec = fd->record;
+
+	/* size difference between old and new key */
+	if ((tree->attributes & HFS_TREE_VARIDXKEYS) ||
+				(tree->cnid == HFSPLUS_ATTR_CNID))
+		newkeylen = hfs_bnode_read_u16(node, 14) + 2;
+	else
+		fd->keylength = newkeylen = tree->max_key_len + 2;
+	hfs_dbg(BNODE_MOD, "update_rec: %d, %d, %d\n",
+		rec, fd->keylength, newkeylen);
+
+	rec_off = tree->node_size - (rec + 2) * 2;
+	end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
+	diff = newkeylen - fd->keylength;
+	if (!diff)
+		goto skip;
+	if (diff > 0) {
+		end_off = hfs_bnode_read_u16(parent, end_rec_off);
+		if (end_rec_off - end_off < diff) {
+
+			hfs_dbg(BNODE_MOD, "splitting index node\n");
+			fd->bnode = parent;
+			new_node = hfs_bnode_split(fd);
+			if (IS_ERR(new_node))
+				return PTR_ERR(new_node);
+			parent = fd->bnode;
+			rec = fd->record;
+			rec_off = tree->node_size - (rec + 2) * 2;
+			end_rec_off = tree->node_size -
+				(parent->num_recs + 1) * 2;
+		}
+	}
+
+	end_off = start_off = hfs_bnode_read_u16(parent, rec_off);
+	hfs_bnode_write_u16(parent, rec_off, start_off + diff);
+	start_off -= 4;	/* move previous cnid too */
+
+	while (rec_off > end_rec_off) {
+		rec_off -= 2;
+		end_off = hfs_bnode_read_u16(parent, rec_off);
+		hfs_bnode_write_u16(parent, rec_off, end_off + diff);
+	}
+	hfs_bnode_move(parent, start_off + diff, start_off,
+		       end_off - start_off);
+skip:
+	hfs_bnode_copy(parent, fd->keyoffset, node, 14, newkeylen);
+	hfs_bnode_dump(parent);
+
+	hfs_bnode_put(node);
+	node = parent;
+
+	if (new_node) {
+		__be32 cnid;
+
+		if (!new_node->parent) {
+			hfs_btree_inc_height(tree);
+			new_node->parent = tree->root;
+		}
+		fd->bnode = hfs_bnode_find(tree, new_node->parent);
+		/* create index key and entry */
+		hfs_bnode_read_key(new_node, fd->search_key, 14);
+		cnid = cpu_to_be32(new_node->this);
+
+		__hfs_brec_find(fd->bnode, fd, hfs_find_rec_by_key);
+		hfs_brec_insert(fd, &cnid, sizeof(cnid));
+		hfs_bnode_put(fd->bnode);
+		hfs_bnode_put(new_node);
+
+		if (!rec) {
+			if (new_node == node)
+				goto out;
+			/* restore search_key */
+			hfs_bnode_read_key(node, fd->search_key, 14);
+		}
+		new_node = NULL;
+	}
+
+	if (!rec && node->parent)
+		goto again;
+out:
+	fd->bnode = node;
+	return 0;
+}
+
+static int hfs_btree_inc_height(struct hfs_btree *tree)
+{
+	struct hfs_bnode *node, *new_node;
+	struct hfs_bnode_desc node_desc;
+	int key_size, rec;
+	__be32 cnid;
+
+	node = NULL;
+	if (tree->root) {
+		node = hfs_bnode_find(tree, tree->root);
+		if (IS_ERR(node))
+			return PTR_ERR(node);
+	}
+	new_node = hfs_bmap_alloc(tree);
+	if (IS_ERR(new_node)) {
+		hfs_bnode_put(node);
+		return PTR_ERR(new_node);
+	}
+
+	tree->root = new_node->this;
+	if (!tree->depth) {
+		tree->leaf_head = tree->leaf_tail = new_node->this;
+		new_node->type = HFS_NODE_LEAF;
+		new_node->num_recs = 0;
+	} else {
+		new_node->type = HFS_NODE_INDEX;
+		new_node->num_recs = 1;
+	}
+	new_node->parent = 0;
+	new_node->next = 0;
+	new_node->prev = 0;
+	new_node->height = ++tree->depth;
+
+	node_desc.next = cpu_to_be32(new_node->next);
+	node_desc.prev = cpu_to_be32(new_node->prev);
+	node_desc.type = new_node->type;
+	node_desc.height = new_node->height;
+	node_desc.num_recs = cpu_to_be16(new_node->num_recs);
+	node_desc.reserved = 0;
+	hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
+
+	rec = tree->node_size - 2;
+	hfs_bnode_write_u16(new_node, rec, 14);
+
+	if (node) {
+		/* insert old root idx into new root */
+		node->parent = tree->root;
+		if (node->type == HFS_NODE_LEAF ||
+				tree->attributes & HFS_TREE_VARIDXKEYS ||
+				tree->cnid == HFSPLUS_ATTR_CNID)
+			key_size = hfs_bnode_read_u16(node, 14) + 2;
+		else
+			key_size = tree->max_key_len + 2;
+		hfs_bnode_copy(new_node, 14, node, 14, key_size);
+
+		if (!(tree->attributes & HFS_TREE_VARIDXKEYS) &&
+				(tree->cnid != HFSPLUS_ATTR_CNID)) {
+			key_size = tree->max_key_len + 2;
+			hfs_bnode_write_u16(new_node, 14, tree->max_key_len);
+		}
+		cnid = cpu_to_be32(node->this);
+		hfs_bnode_write(new_node, &cnid, 14 + key_size, 4);
+
+		rec -= 2;
+		hfs_bnode_write_u16(new_node, rec, 14 + key_size + 4);
+
+		hfs_bnode_put(node);
+	}
+	hfs_bnode_put(new_node);
+	mark_inode_dirty(tree->inode);
+
+	return 0;
+}