// 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; } 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; while (!tree->free_nodes) { struct inode *inode = tree->inode; struct hfsplus_inode_info *hip = HFSPLUS_I(inode); u32 count; int res; res = hfsplus_file_extend(inode, hfs_bnode_need_zeroout(tree)); if (res) return ERR_PTR(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; } 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; hfs_bnode_put(node); if (!i) { /* panic */; pr_crit("unable to free bnode %u. " "bmap not found!\n", node->this); return; } 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); }