1 files changed, 511 insertions, 0 deletions

diff --git a/fs/hfsplus/btree.c b/fs/hfsplus/btree.c
new file mode 100644
index 000000000..66774f4cb
--- /dev/null
+++ b/fs/hfsplus/btree.c
@@ -0,0 +1,511 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/hfsplus/btree.c
+ *
+ * Copyright (C) 2001
+ * Brad Boyer (flar@allandria.com)
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ *
+ * Handle opening/closing btree
+ */
+
+#include <linux/slab.h>
+#include <linux/pagemap.h>
+#include <linux/log2.h>
+
+#include "hfsplus_fs.h"
+#include "hfsplus_raw.h"
+
+/*
+ * Initial source code of clump size calculation is gotten
+ * from http://opensource.apple.com/tarballs/diskdev_cmds/
+ */
+#define CLUMP_ENTRIES	15
+
+static short clumptbl[CLUMP_ENTRIES * 3] = {
+/*
+ *	    Volume	Attributes	 Catalog	 Extents
+ *	     Size	Clump (MB)	Clump (MB)	Clump (MB)
+ */
+	/*   1GB */	  4,		  4,		 4,
+	/*   2GB */	  6,		  6,		 4,
+	/*   4GB */	  8,		  8,		 4,
+	/*   8GB */	 11,		 11,		 5,
+	/*
+	 * For volumes 16GB and larger, we want to make sure that a full OS
+	 * install won't require fragmentation of the Catalog or Attributes
+	 * B-trees.  We do this by making the clump sizes sufficiently large,
+	 * and by leaving a gap after the B-trees for them to grow into.
+	 *
+	 * For SnowLeopard 10A298, a FullNetInstall with all packages selected
+	 * results in:
+	 * Catalog B-tree Header
+	 *	nodeSize:          8192
+	 *	totalNodes:       31616
+	 *	freeNodes:         1978
+	 * (used = 231.55 MB)
+	 * Attributes B-tree Header
+	 *	nodeSize:          8192
+	 *	totalNodes:       63232
+	 *	freeNodes:          958
+	 * (used = 486.52 MB)
+	 *
+	 * We also want Time Machine backup volumes to have a sufficiently
+	 * large clump size to reduce fragmentation.
+	 *
+	 * The series of numbers for Catalog and Attribute form a geometric
+	 * series. For Catalog (16GB to 512GB), each term is 8**(1/5) times
+	 * the previous term.  For Attributes (16GB to 512GB), each term is
+	 * 4**(1/5) times the previous term.  For 1TB to 16TB, each term is
+	 * 2**(1/5) times the previous term.
+	 */
+	/*  16GB */	 64,		 32,		 5,
+	/*  32GB */	 84,		 49,		 6,
+	/*  64GB */	111,		 74,		 7,
+	/* 128GB */	147,		111,		 8,
+	/* 256GB */	194,		169,		 9,
+	/* 512GB */	256,		256,		11,
+	/*   1TB */	294,		294,		14,
+	/*   2TB */	338,		338,		16,
+	/*   4TB */	388,		388,		20,
+	/*   8TB */	446,		446,		25,
+	/*  16TB */	512,		512,		32
+};
+
+u32 hfsplus_calc_btree_clump_size(u32 block_size, u32 node_size,
+					u64 sectors, int file_id)
+{
+	u32 mod = max(node_size, block_size);
+	u32 clump_size;
+	int column;
+	int i;
+
+	/* Figure out which column of the above table to use for this file. */
+	switch (file_id) {
+	case HFSPLUS_ATTR_CNID:
+		column = 0;
+		break;
+	case HFSPLUS_CAT_CNID:
+		column = 1;
+		break;
+	default:
+		column = 2;
+		break;
+	}
+
+	/*
+	 * The default clump size is 0.8% of the volume size. And
+	 * it must also be a multiple of the node and block size.
+	 */
+	if (sectors < 0x200000) {
+		clump_size = sectors << 2;	/*  0.8 %  */
+		if (clump_size < (8 * node_size))
+			clump_size = 8 * node_size;
+	} else {
+		/* turn exponent into table index... */
+		for (i = 0, sectors = sectors >> 22;
+		     sectors && (i < CLUMP_ENTRIES - 1);
+		     ++i, sectors = sectors >> 1) {
+			/* empty body */
+		}
+
+		clump_size = clumptbl[column + (i) * 3] * 1024 * 1024;
+	}
+
+	/*
+	 * Round the clump size to a multiple of node and block size.
+	 * NOTE: This rounds down.
+	 */
+	clump_size /= mod;
+	clump_size *= mod;
+
+	/*
+	 * Rounding down could have rounded down to 0 if the block size was
+	 * greater than the clump size.  If so, just use one block or node.
+	 */
+	if (clump_size == 0)
+		clump_size = mod;
+
+	return clump_size;
+}
+
+/* Get a reference to a B*Tree and do some initial checks */
+struct hfs_btree *hfs_btree_open(struct super_block *sb, u32 id)
+{
+	struct hfs_btree *tree;
+	struct hfs_btree_header_rec *head;
+	struct address_space *mapping;
+	struct inode *inode;
+	struct page *page;
+	unsigned int size;
+
+	tree = kzalloc(sizeof(*tree), GFP_KERNEL);
+	if (!tree)
+		return NULL;
+
+	mutex_init(&tree->tree_lock);
+	spin_lock_init(&tree->hash_lock);
+	tree->sb = sb;
+	tree->cnid = id;
+	inode = hfsplus_iget(sb, id);
+	if (IS_ERR(inode))
+		goto free_tree;
+	tree->inode = inode;
+
+	if (!HFSPLUS_I(tree->inode)->first_blocks) {
+		pr_err("invalid btree extent records (0 size)\n");
+		goto free_inode;
+	}
+
+	mapping = tree->inode->i_mapping;
+	page = read_mapping_page(mapping, 0, NULL);
+	if (IS_ERR(page))
+		goto free_inode;
+
+	/* Load the header */
+	head = (struct hfs_btree_header_rec *)(kmap(page) +
+		sizeof(struct hfs_bnode_desc));
+	tree->root = be32_to_cpu(head->root);
+	tree->leaf_count = be32_to_cpu(head->leaf_count);
+	tree->leaf_head = be32_to_cpu(head->leaf_head);
+	tree->leaf_tail = be32_to_cpu(head->leaf_tail);
+	tree->node_count = be32_to_cpu(head->node_count);
+	tree->free_nodes = be32_to_cpu(head->free_nodes);
+	tree->attributes = be32_to_cpu(head->attributes);
+	tree->node_size = be16_to_cpu(head->node_size);
+	tree->max_key_len = be16_to_cpu(head->max_key_len);
+	tree->depth = be16_to_cpu(head->depth);
+
+	/* Verify the tree and set the correct compare function */
+	switch (id) {
+	case HFSPLUS_EXT_CNID:
+		if (tree->max_key_len != HFSPLUS_EXT_KEYLEN - sizeof(u16)) {
+			pr_err("invalid extent max_key_len %d\n",
+				tree->max_key_len);
+			goto fail_page;
+		}
+		if (tree->attributes & HFS_TREE_VARIDXKEYS) {
+			pr_err("invalid extent btree flag\n");
+			goto fail_page;
+		}
+
+		tree->keycmp = hfsplus_ext_cmp_key;
+		break;
+	case HFSPLUS_CAT_CNID:
+		if (tree->max_key_len != HFSPLUS_CAT_KEYLEN - sizeof(u16)) {
+			pr_err("invalid catalog max_key_len %d\n",
+				tree->max_key_len);
+			goto fail_page;
+		}
+		if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) {
+			pr_err("invalid catalog btree flag\n");
+			goto fail_page;
+		}
+
+		if (test_bit(HFSPLUS_SB_HFSX, &HFSPLUS_SB(sb)->flags) &&
+		    (head->key_type == HFSPLUS_KEY_BINARY))
+			tree->keycmp = hfsplus_cat_bin_cmp_key;
+		else {
+			tree->keycmp = hfsplus_cat_case_cmp_key;
+			set_bit(HFSPLUS_SB_CASEFOLD, &HFSPLUS_SB(sb)->flags);
+		}
+		break;
+	case HFSPLUS_ATTR_CNID:
+		if (tree->max_key_len != HFSPLUS_ATTR_KEYLEN - sizeof(u16)) {
+			pr_err("invalid attributes max_key_len %d\n",
+				tree->max_key_len);
+			goto fail_page;
+		}
+		tree->keycmp = hfsplus_attr_bin_cmp_key;
+		break;
+	default:
+		pr_err("unknown B*Tree requested\n");
+		goto fail_page;
+	}
+
+	if (!(tree->attributes & HFS_TREE_BIGKEYS)) {
+		pr_err("invalid btree flag\n");
+		goto fail_page;
+	}
+
+	size = tree->node_size;
+	if (!is_power_of_2(size))
+		goto fail_page;
+	if (!tree->node_count)
+		goto fail_page;
+
+	tree->node_size_shift = ffs(size) - 1;
+
+	tree->pages_per_bnode =
+		(tree->node_size + PAGE_SIZE - 1) >>
+		PAGE_SHIFT;
+
+	kunmap(page);
+	put_page(page);
+	return tree;
+
+ fail_page:
+	put_page(page);
+ free_inode:
+	tree->inode->i_mapping->a_ops = &hfsplus_aops;
+	iput(tree->inode);
+ free_tree:
+	kfree(tree);
+	return NULL;
+}
+
+/* Release resources used by a btree */
+void hfs_btree_close(struct hfs_btree *tree)
+{
+	struct hfs_bnode *node;
+	int i;
+
+	if (!tree)
+		return;
+
+	for (i = 0; i < NODE_HASH_SIZE; i++) {
+		while ((node = tree->node_hash[i])) {
+			tree->node_hash[i] = node->next_hash;
+			if (atomic_read(&node->refcnt))
+				pr_crit("node %d:%d "
+						"still has %d user(s)!\n",
+					node->tree->cnid, node->this,
+					atomic_read(&node->refcnt));
+			hfs_bnode_free(node);
+			tree->node_hash_cnt--;
+		}
+	}
+	iput(tree->inode);
+	kfree(tree);
+}
+
+int hfs_btree_write(struct hfs_btree *tree)
+{
+	struct hfs_btree_header_rec *head;
+	struct hfs_bnode *node;
+	struct page *page;
+
+	node = hfs_bnode_find(tree, 0);
+	if (IS_ERR(node))
+		/* panic? */
+		return -EIO;
+	/* Load the header */
+	page = node->page[0];
+	head = (struct hfs_btree_header_rec *)(kmap(page) +
+		sizeof(struct hfs_bnode_desc));
+
+	head->root = cpu_to_be32(tree->root);
+	head->leaf_count = cpu_to_be32(tree->leaf_count);
+	head->leaf_head = cpu_to_be32(tree->leaf_head);
+	head->leaf_tail = cpu_to_be32(tree->leaf_tail);
+	head->node_count = cpu_to_be32(tree->node_count);
+	head->free_nodes = cpu_to_be32(tree->free_nodes);
+	head->attributes = cpu_to_be32(tree->attributes);
+	head->depth = cpu_to_be16(tree->depth);
+
+	kunmap(page);
+	set_page_dirty(page);
+	hfs_bnode_put(node);
+	return 0;
+}
+
+static struct hfs_bnode *hfs_bmap_new_bmap(struct hfs_bnode *prev, u32 idx)
+{
+	struct hfs_btree *tree = prev->tree;
+	struct hfs_bnode *node;
+	struct hfs_bnode_desc desc;
+	__be32 cnid;
+
+	node = hfs_bnode_create(tree, idx);
+	if (IS_ERR(node))
+		return node;
+
+	tree->free_nodes--;
+	prev->next = idx;
+	cnid = cpu_to_be32(idx);
+	hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
+
+	node->type = HFS_NODE_MAP;
+	node->num_recs = 1;
+	hfs_bnode_clear(node, 0, tree->node_size);
+	desc.next = 0;
+	desc.prev = 0;
+	desc.type = HFS_NODE_MAP;
+	desc.height = 0;
+	desc.num_recs = cpu_to_be16(1);
+	desc.reserved = 0;
+	hfs_bnode_write(node, &desc, 0, sizeof(desc));
+	hfs_bnode_write_u16(node, 14, 0x8000);
+	hfs_bnode_write_u16(node, tree->node_size - 2, 14);
+	hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6);
+
+	return node;
+}
+
+/* Make sure @tree has enough space for the @rsvd_nodes */
+int hfs_bmap_reserve(struct hfs_btree *tree, int rsvd_nodes)
+{
+	struct inode *inode = tree->inode;
+	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
+	u32 count;
+	int res;
+
+	if (rsvd_nodes <= 0)
+		return 0;
+
+	while (tree->free_nodes < rsvd_nodes) {
+		res = hfsplus_file_extend(inode, hfs_bnode_need_zeroout(tree));
+		if (res)
+			return res;
+		hip->phys_size = inode->i_size =
+			(loff_t)hip->alloc_blocks <<
+				HFSPLUS_SB(tree->sb)->alloc_blksz_shift;
+		hip->fs_blocks =
+			hip->alloc_blocks << HFSPLUS_SB(tree->sb)->fs_shift;
+		inode_set_bytes(inode, inode->i_size);
+		count = inode->i_size >> tree->node_size_shift;
+		tree->free_nodes += count - tree->node_count;
+		tree->node_count = count;
+	}
+	return 0;
+}
+
+struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree)
+{
+	struct hfs_bnode *node, *next_node;
+	struct page **pagep;
+	u32 nidx, idx;
+	unsigned off;
+	u16 off16;
+	u16 len;
+	u8 *data, byte, m;
+	int i, res;
+
+	res = hfs_bmap_reserve(tree, 1);
+	if (res)
+		return ERR_PTR(res);
+
+	nidx = 0;
+	node = hfs_bnode_find(tree, nidx);
+	if (IS_ERR(node))
+		return node;
+	len = hfs_brec_lenoff(node, 2, &off16);
+	off = off16;
+
+	off += node->page_offset;
+	pagep = node->page + (off >> PAGE_SHIFT);
+	data = kmap(*pagep);
+	off &= ~PAGE_MASK;
+	idx = 0;
+
+	for (;;) {
+		while (len) {
+			byte = data[off];
+			if (byte != 0xff) {
+				for (m = 0x80, i = 0; i < 8; m >>= 1, i++) {
+					if (!(byte & m)) {
+						idx += i;
+						data[off] |= m;
+						set_page_dirty(*pagep);
+						kunmap(*pagep);
+						tree->free_nodes--;
+						mark_inode_dirty(tree->inode);
+						hfs_bnode_put(node);
+						return hfs_bnode_create(tree,
+							idx);
+					}
+				}
+			}
+			if (++off >= PAGE_SIZE) {
+				kunmap(*pagep);
+				data = kmap(*++pagep);
+				off = 0;
+			}
+			idx += 8;
+			len--;
+		}
+		kunmap(*pagep);
+		nidx = node->next;
+		if (!nidx) {
+			hfs_dbg(BNODE_MOD, "create new bmap node\n");
+			next_node = hfs_bmap_new_bmap(node, idx);
+		} else
+			next_node = hfs_bnode_find(tree, nidx);
+		hfs_bnode_put(node);
+		if (IS_ERR(next_node))
+			return next_node;
+		node = next_node;
+
+		len = hfs_brec_lenoff(node, 0, &off16);
+		off = off16;
+		off += node->page_offset;
+		pagep = node->page + (off >> PAGE_SHIFT);
+		data = kmap(*pagep);
+		off &= ~PAGE_MASK;
+	}
+}
+
+void hfs_bmap_free(struct hfs_bnode *node)
+{
+	struct hfs_btree *tree;
+	struct page *page;
+	u16 off, len;
+	u32 nidx;
+	u8 *data, byte, m;
+
+	hfs_dbg(BNODE_MOD, "btree_free_node: %u\n", node->this);
+	BUG_ON(!node->this);
+	tree = node->tree;
+	nidx = node->this;
+	node = hfs_bnode_find(tree, 0);
+	if (IS_ERR(node))
+		return;
+	len = hfs_brec_lenoff(node, 2, &off);
+	while (nidx >= len * 8) {
+		u32 i;
+
+		nidx -= len * 8;
+		i = node->next;
+		if (!i) {
+			/* panic */;
+			pr_crit("unable to free bnode %u. "
+					"bmap not found!\n",
+				node->this);
+			hfs_bnode_put(node);
+			return;
+		}
+		hfs_bnode_put(node);
+		node = hfs_bnode_find(tree, i);
+		if (IS_ERR(node))
+			return;
+		if (node->type != HFS_NODE_MAP) {
+			/* panic */;
+			pr_crit("invalid bmap found! "
+					"(%u,%d)\n",
+				node->this, node->type);
+			hfs_bnode_put(node);
+			return;
+		}
+		len = hfs_brec_lenoff(node, 0, &off);
+	}
+	off += node->page_offset + nidx / 8;
+	page = node->page[off >> PAGE_SHIFT];
+	data = kmap(page);
+	off &= ~PAGE_MASK;
+	m = 1 << (~nidx & 7);
+	byte = data[off];
+	if (!(byte & m)) {
+		pr_crit("trying to free free bnode "
+				"%u(%d)\n",
+			node->this, node->type);
+		kunmap(page);
+		hfs_bnode_put(node);
+		return;
+	}
+	data[off] = byte & ~m;
+	set_page_dirty(page);
+	kunmap(page);
+	hfs_bnode_put(node);
+	tree->free_nodes++;
+	mark_inode_dirty(tree->inode);
+}