Initial import

1 files changed, 293 insertions, 0 deletions

diff --git a/fs/hfsplus/bfind.c b/fs/hfsplus/bfind.c
new file mode 100644
index 000000000..528e38b5a
--- /dev/null
+++ b/fs/hfsplus/bfind.c
@@ -0,0 +1,293 @@
+/*
+ *  linux/fs/hfsplus/bfind.c
+ *
+ * Copyright (C) 2001
+ * Brad Boyer (flar@allandria.com)
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ *
+ * Search routines for btrees
+ */
+
+#include <linux/slab.h>
+#include "hfsplus_fs.h"
+
+int hfs_find_init(struct hfs_btree *tree, struct hfs_find_data *fd)
+{
+	void *ptr;
+
+	fd->tree = tree;
+	fd->bnode = NULL;
+	ptr = kmalloc(tree->max_key_len * 2 + 4, GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+	fd->search_key = ptr;
+	fd->key = ptr + tree->max_key_len + 2;
+	hfs_dbg(BNODE_REFS, "find_init: %d (%p)\n",
+		tree->cnid, __builtin_return_address(0));
+	switch (tree->cnid) {
+	case HFSPLUS_CAT_CNID:
+		mutex_lock_nested(&tree->tree_lock, CATALOG_BTREE_MUTEX);
+		break;
+	case HFSPLUS_EXT_CNID:
+		mutex_lock_nested(&tree->tree_lock, EXTENTS_BTREE_MUTEX);
+		break;
+	case HFSPLUS_ATTR_CNID:
+		mutex_lock_nested(&tree->tree_lock, ATTR_BTREE_MUTEX);
+		break;
+	default:
+		BUG();
+	}
+	return 0;
+}
+
+void hfs_find_exit(struct hfs_find_data *fd)
+{
+	hfs_bnode_put(fd->bnode);
+	kfree(fd->search_key);
+	hfs_dbg(BNODE_REFS, "find_exit: %d (%p)\n",
+		fd->tree->cnid, __builtin_return_address(0));
+	mutex_unlock(&fd->tree->tree_lock);
+	fd->tree = NULL;
+}
+
+int hfs_find_1st_rec_by_cnid(struct hfs_bnode *bnode,
+				struct hfs_find_data *fd,
+				int *begin,
+				int *end,
+				int *cur_rec)
+{
+	__be32 cur_cnid;
+	__be32 search_cnid;
+
+	if (bnode->tree->cnid == HFSPLUS_EXT_CNID) {
+		cur_cnid = fd->key->ext.cnid;
+		search_cnid = fd->search_key->ext.cnid;
+	} else if (bnode->tree->cnid == HFSPLUS_CAT_CNID) {
+		cur_cnid = fd->key->cat.parent;
+		search_cnid = fd->search_key->cat.parent;
+	} else if (bnode->tree->cnid == HFSPLUS_ATTR_CNID) {
+		cur_cnid = fd->key->attr.cnid;
+		search_cnid = fd->search_key->attr.cnid;
+	} else {
+		cur_cnid = 0;	/* used-uninitialized warning */
+		search_cnid = 0;
+		BUG();
+	}
+
+	if (cur_cnid == search_cnid) {
+		(*end) = (*cur_rec);
+		if ((*begin) == (*end))
+			return 1;
+	} else {
+		if (be32_to_cpu(cur_cnid) < be32_to_cpu(search_cnid))
+			(*begin) = (*cur_rec) + 1;
+		else
+			(*end) = (*cur_rec) - 1;
+	}
+
+	return 0;
+}
+
+int hfs_find_rec_by_key(struct hfs_bnode *bnode,
+				struct hfs_find_data *fd,
+				int *begin,
+				int *end,
+				int *cur_rec)
+{
+	int cmpval;
+
+	cmpval = bnode->tree->keycmp(fd->key, fd->search_key);
+	if (!cmpval) {
+		(*end) = (*cur_rec);
+		return 1;
+	}
+	if (cmpval < 0)
+		(*begin) = (*cur_rec) + 1;
+	else
+		*(end) = (*cur_rec) - 1;
+
+	return 0;
+}
+
+/* Find the record in bnode that best matches key (not greater than...)*/
+int __hfs_brec_find(struct hfs_bnode *bnode, struct hfs_find_data *fd,
+					search_strategy_t rec_found)
+{
+	u16 off, len, keylen;
+	int rec;
+	int b, e;
+	int res;
+
+	BUG_ON(!rec_found);
+	b = 0;
+	e = bnode->num_recs - 1;
+	res = -ENOENT;
+	do {
+		rec = (e + b) / 2;
+		len = hfs_brec_lenoff(bnode, rec, &off);
+		keylen = hfs_brec_keylen(bnode, rec);
+		if (keylen == 0) {
+			res = -EINVAL;
+			goto fail;
+		}
+		hfs_bnode_read(bnode, fd->key, off, keylen);
+		if (rec_found(bnode, fd, &b, &e, &rec)) {
+			res = 0;
+			goto done;
+		}
+	} while (b <= e);
+
+	if (rec != e && e >= 0) {
+		len = hfs_brec_lenoff(bnode, e, &off);
+		keylen = hfs_brec_keylen(bnode, e);
+		if (keylen == 0) {
+			res = -EINVAL;
+			goto fail;
+		}
+		hfs_bnode_read(bnode, fd->key, off, keylen);
+	}
+
+done:
+	fd->record = e;
+	fd->keyoffset = off;
+	fd->keylength = keylen;
+	fd->entryoffset = off + keylen;
+	fd->entrylength = len - keylen;
+
+fail:
+	return res;
+}
+
+/* Traverse a B*Tree from the root to a leaf finding best fit to key */
+/* Return allocated copy of node found, set recnum to best record */
+int hfs_brec_find(struct hfs_find_data *fd, search_strategy_t do_key_compare)
+{
+	struct hfs_btree *tree;
+	struct hfs_bnode *bnode;
+	u32 nidx, parent;
+	__be32 data;
+	int height, res;
+
+	tree = fd->tree;
+	if (fd->bnode)
+		hfs_bnode_put(fd->bnode);
+	fd->bnode = NULL;
+	nidx = tree->root;
+	if (!nidx)
+		return -ENOENT;
+	height = tree->depth;
+	res = 0;
+	parent = 0;
+	for (;;) {
+		bnode = hfs_bnode_find(tree, nidx);
+		if (IS_ERR(bnode)) {
+			res = PTR_ERR(bnode);
+			bnode = NULL;
+			break;
+		}
+		if (bnode->height != height)
+			goto invalid;
+		if (bnode->type != (--height ? HFS_NODE_INDEX : HFS_NODE_LEAF))
+			goto invalid;
+		bnode->parent = parent;
+
+		res = __hfs_brec_find(bnode, fd, do_key_compare);
+		if (!height)
+			break;
+		if (fd->record < 0)
+			goto release;
+
+		parent = nidx;
+		hfs_bnode_read(bnode, &data, fd->entryoffset, 4);
+		nidx = be32_to_cpu(data);
+		hfs_bnode_put(bnode);
+	}
+	fd->bnode = bnode;
+	return res;
+
+invalid:
+	pr_err("inconsistency in B*Tree (%d,%d,%d,%u,%u)\n",
+		height, bnode->height, bnode->type, nidx, parent);
+	res = -EIO;
+release:
+	hfs_bnode_put(bnode);
+	return res;
+}
+
+int hfs_brec_read(struct hfs_find_data *fd, void *rec, int rec_len)
+{
+	int res;
+
+	res = hfs_brec_find(fd, hfs_find_rec_by_key);
+	if (res)
+		return res;
+	if (fd->entrylength > rec_len)
+		return -EINVAL;
+	hfs_bnode_read(fd->bnode, rec, fd->entryoffset, fd->entrylength);
+	return 0;
+}
+
+int hfs_brec_goto(struct hfs_find_data *fd, int cnt)
+{
+	struct hfs_btree *tree;
+	struct hfs_bnode *bnode;
+	int idx, res = 0;
+	u16 off, len, keylen;
+
+	bnode = fd->bnode;
+	tree = bnode->tree;
+
+	if (cnt < 0) {
+		cnt = -cnt;
+		while (cnt > fd->record) {
+			cnt -= fd->record + 1;
+			fd->record = bnode->num_recs - 1;
+			idx = bnode->prev;
+			if (!idx) {
+				res = -ENOENT;
+				goto out;
+			}
+			hfs_bnode_put(bnode);
+			bnode = hfs_bnode_find(tree, idx);
+			if (IS_ERR(bnode)) {
+				res = PTR_ERR(bnode);
+				bnode = NULL;
+				goto out;
+			}
+		}
+		fd->record -= cnt;
+	} else {
+		while (cnt >= bnode->num_recs - fd->record) {
+			cnt -= bnode->num_recs - fd->record;
+			fd->record = 0;
+			idx = bnode->next;
+			if (!idx) {
+				res = -ENOENT;
+				goto out;
+			}
+			hfs_bnode_put(bnode);
+			bnode = hfs_bnode_find(tree, idx);
+			if (IS_ERR(bnode)) {
+				res = PTR_ERR(bnode);
+				bnode = NULL;
+				goto out;
+			}
+		}
+		fd->record += cnt;
+	}
+
+	len = hfs_brec_lenoff(bnode, fd->record, &off);
+	keylen = hfs_brec_keylen(bnode, fd->record);
+	if (keylen == 0) {
+		res = -EINVAL;
+		goto out;
+	}
+	fd->keyoffset = off;
+	fd->keylength = keylen;
+	fd->entryoffset = off + keylen;
+	fd->entrylength = len - keylen;
+	hfs_bnode_read(bnode, fd->key, off, keylen);
+out:
+	fd->bnode = bnode;
+	return res;
+}