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-rw-r--r--fs/hfsplus/btree.c679
1 files changed, 679 insertions, 0 deletions
diff --git a/fs/hfsplus/btree.c b/fs/hfsplus/btree.c
new file mode 100644
index 000000000..2ea8cd565
--- /dev/null
+++ b/fs/hfsplus/btree.c
@@ -0,0 +1,679 @@
+// 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;
+}
+
+/* Context for iterating b-tree map pages
+ * @page_idx: The index of the page within the b-node's page array
+ * @off: The byte offset within the mapped page
+ * @len: The remaining length of the map record
+ */
+struct hfs_bmap_ctx {
+ unsigned int page_idx;
+ unsigned int off;
+ u16 len;
+};
+
+/*
+ * Finds the specific page containing the requested byte offset within the map
+ * record. Automatically handles the difference between header and map nodes.
+ * Returns the struct page pointer, or an ERR_PTR on failure.
+ * Note: The caller is responsible for mapping/unmapping the returned page.
+ */
+static struct page *hfs_bmap_get_map_page(struct hfs_bnode *node,
+ struct hfs_bmap_ctx *ctx,
+ u32 byte_offset)
+{
+ u16 rec_idx, off16;
+ unsigned int page_off;
+
+ if (node->this == HFSPLUS_TREE_HEAD) {
+ if (node->type != HFS_NODE_HEADER) {
+ pr_err("hfsplus: invalid btree header node\n");
+ return ERR_PTR(-EIO);
+ }
+ rec_idx = HFSPLUS_BTREE_HDR_MAP_REC_INDEX;
+ } else {
+ if (node->type != HFS_NODE_MAP) {
+ pr_err("hfsplus: invalid btree map node\n");
+ return ERR_PTR(-EIO);
+ }
+ rec_idx = HFSPLUS_BTREE_MAP_NODE_REC_INDEX;
+ }
+
+ ctx->len = hfs_brec_lenoff(node, rec_idx, &off16);
+ if (hfs_brec_len_invalid(node, ctx->len))
+ return ERR_PTR(-EINVAL);
+
+ if (!is_bnode_offset_valid(node, off16))
+ return ERR_PTR(-EIO);
+
+ ctx->len = check_and_correct_requested_length(node, off16, ctx->len);
+
+ if (byte_offset >= ctx->len)
+ return ERR_PTR(-EINVAL);
+
+ page_off = (u32)off16 + node->page_offset + byte_offset;
+ ctx->page_idx = page_off >> PAGE_SHIFT;
+ ctx->off = page_off & ~PAGE_MASK;
+
+ return node->page[ctx->page_idx];
+}
+
+/**
+ * hfs_bmap_test_bit - test a bit in the b-tree map
+ * @node: the b-tree node containing the map record
+ * @node_bit_idx: the relative bit index within the node's map record
+ *
+ * Returns true if set, false if clear or on failure.
+ */
+static bool hfs_bmap_test_bit(struct hfs_bnode *node, u32 node_bit_idx)
+{
+ struct hfs_bmap_ctx ctx;
+ struct page *page;
+ u8 *bmap, byte, mask;
+
+ page = hfs_bmap_get_map_page(node, &ctx, node_bit_idx / BITS_PER_BYTE);
+ if (IS_ERR(page))
+ return false;
+
+ bmap = kmap_local_page(page);
+ byte = bmap[ctx.off];
+ kunmap_local(bmap);
+
+ mask = 1 << (7 - (node_bit_idx % BITS_PER_BYTE));
+ return (byte & mask) != 0;
+}
+
+
+/**
+ * hfs_bmap_clear_bit - clear a bit in the b-tree map
+ * @node: the b-tree node containing the map record
+ * @node_bit_idx: the relative bit index within the node's map record
+ *
+ * Returns 0 on success, -EINVAL if already clear, or negative error code.
+ */
+static int hfs_bmap_clear_bit(struct hfs_bnode *node, u32 node_bit_idx)
+{
+ struct hfs_bmap_ctx ctx;
+ struct page *page;
+ u8 *bmap, mask;
+
+ page = hfs_bmap_get_map_page(node, &ctx, node_bit_idx / BITS_PER_BYTE);
+ if (IS_ERR(page))
+ return PTR_ERR(page);
+
+ bmap = kmap_local_page(page);
+
+ mask = 1 << (7 - (node_bit_idx % BITS_PER_BYTE));
+
+ if (!(bmap[ctx.off] & mask)) {
+ kunmap_local(bmap);
+ return -EINVAL;
+ }
+
+ bmap[ctx.off] &= ~mask;
+ set_page_dirty(page);
+ kunmap_local(bmap);
+
+ return 0;
+}
+
+#define HFS_EXTENT_TREE_NAME "Extents Overflow File"
+#define HFS_CATALOG_TREE_NAME "Catalog File"
+#define HFS_ATTR_TREE_NAME "Attributes File"
+#define HFS_UNKNOWN_TREE_NAME "Unknown B-tree"
+
+static const char *hfs_btree_name(u32 cnid)
+{
+ switch (cnid) {
+ case HFSPLUS_EXT_CNID:
+ return HFS_EXTENT_TREE_NAME;
+ case HFSPLUS_CAT_CNID:
+ return HFS_CATALOG_TREE_NAME;
+ case HFSPLUS_ATTR_CNID:
+ return HFS_ATTR_TREE_NAME;
+ default:
+ return HFS_UNKNOWN_TREE_NAME;
+ }
+}
+
+/* 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 hfs_bnode *node;
+ struct inode *inode;
+ struct page *page;
+ unsigned int size;
+
+ tree = kzalloc_obj(*tree);
+ 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_local_page(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 (size < HFSPLUS_NODE_MINSZ || size > HFSPLUS_NODE_MXSZ)
+ goto fail_page;
+ 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_local(head);
+ put_page(page);
+
+ node = hfs_bnode_find(tree, HFSPLUS_TREE_HEAD);
+ if (IS_ERR(node))
+ goto free_inode;
+
+ if (!hfs_bmap_test_bit(node, 0)) {
+ pr_warn("(%s): %s (cnid 0x%x) map record invalid or bitmap corruption detected, forcing read-only.\n",
+ sb->s_id, hfs_btree_name(id), id);
+ pr_warn("Run fsck.hfsplus to repair.\n");
+ sb->s_flags |= SB_RDONLY;
+ }
+
+ hfs_bnode_put(node);
+
+ return tree;
+
+ fail_page:
+ kunmap_local(head);
+ 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_local_page(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_local(head);
+ 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, u32 rsvd_nodes)
+{
+ struct inode *inode = tree->inode;
+ struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
+ u32 count;
+ int res;
+
+ lockdep_assert_held(&tree->tree_lock);
+
+ 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 hfs_bmap_ctx ctx;
+ struct page *page;
+ u32 nidx, idx;
+ u8 *data, byte, m;
+ int i, res;
+
+ lockdep_assert_held(&tree->tree_lock);
+
+ 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;
+
+ page = hfs_bmap_get_map_page(node, &ctx, 0);
+ if (IS_ERR(page)) {
+ res = PTR_ERR(page);
+ hfs_bnode_put(node);
+ return ERR_PTR(res);
+ }
+
+ data = kmap_local_page(page);
+ idx = 0;
+
+ for (;;) {
+ while (ctx.len) {
+ byte = data[ctx.off];
+ if (byte != 0xff) {
+ for (m = 0x80, i = 0; i < 8; m >>= 1, i++) {
+ if (!(byte & m)) {
+ idx += i;
+ data[ctx.off] |= m;
+ set_page_dirty(page);
+ kunmap_local(data);
+ tree->free_nodes--;
+ hfs_btree_write(tree);
+ mark_inode_dirty(tree->inode);
+ hfs_bnode_put(node);
+ return hfs_bnode_create(tree,
+ idx);
+ }
+ }
+ }
+ if (++ctx.off >= PAGE_SIZE) {
+ kunmap_local(data);
+ page = node->page[++ctx.page_idx];
+ data = kmap_local_page(page);
+ ctx.off = 0;
+ }
+ idx += 8;
+ ctx.len--;
+ }
+ kunmap_local(data);
+ nidx = node->next;
+ if (!nidx) {
+ hfs_dbg("create new bmap node\n");
+ next_node = hfs_bmap_new_bmap(node, idx);
+ hfs_btree_write(tree);
+ } else
+ next_node = hfs_bnode_find(tree, nidx);
+ hfs_bnode_put(node);
+ if (IS_ERR(next_node))
+ return next_node;
+ node = next_node;
+
+ page = hfs_bmap_get_map_page(node, &ctx, 0);
+ if (IS_ERR(page)) {
+ res = PTR_ERR(page);
+ hfs_bnode_put(node);
+ return ERR_PTR(res);
+ }
+ data = kmap_local_page(page);
+ }
+}
+
+void hfs_bmap_free(struct hfs_bnode *node)
+{
+ struct hfs_btree *tree;
+ u16 off, len;
+ u32 nidx;
+ int res;
+
+ hfs_dbg("node %u\n", node->this);
+ BUG_ON(!node->this);
+ tree = node->tree;
+ lockdep_assert_held(&tree->tree_lock);
+ nidx = node->this;
+ node = hfs_bnode_find(tree, 0);
+ if (IS_ERR(node))
+ return;
+ len = hfs_brec_lenoff(node, 2, &off);
+ if (hfs_brec_len_invalid(node, len)) {
+ pr_err("invalid bmap record length: node %u, len %u\n",
+ node->this, len);
+ hfs_bnode_put(node);
+ return;
+ }
+ 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);
+ if (hfs_brec_len_invalid(node, len)) {
+ pr_err("invalid bmap record length: node %u, len %u\n",
+ node->this, len);
+ hfs_bnode_put(node);
+ return;
+ }
+ }
+
+ res = hfs_bmap_clear_bit(node, nidx);
+ if (res == -EINVAL) {
+ pr_crit("trying to free the freed bnode %u(%d)\n",
+ nidx, node->type);
+ } else if (res) {
+ pr_crit("fail to free bnode %u(%d)\n",
+ nidx, node->type);
+ } else {
+ tree->free_nodes++;
+ hfs_btree_write(tree);
+ mark_inode_dirty(tree->inode);
+ }
+
+ hfs_bnode_put(node);
+}
generated by cgit v1.3.1 (git 2.54.0) at 2026-10-12 10:11:04 +0000