From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! --- fs/hfsplus/btree.c | 319 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 319 insertions(+) create mode 100644 fs/hfsplus/btree.c (limited to 'fs/hfsplus/btree.c') diff --git a/fs/hfsplus/btree.c b/fs/hfsplus/btree.c new file mode 100644 index 000000000000..44326aa2bd34 --- /dev/null +++ b/fs/hfsplus/btree.c @@ -0,0 +1,319 @@ +/* + * linux/fs/hfsplus/btree.c + * + * Copyright (C) 2001 + * Brad Boyer (flar@allandria.com) + * (C) 2003 Ardis Technologies + * + * Handle opening/closing btree + */ + +#include +#include + +#include "hfsplus_fs.h" +#include "hfsplus_raw.h" + + +/* 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 page *page; + unsigned int size; + + tree = kmalloc(sizeof(*tree), GFP_KERNEL); + if (!tree) + return NULL; + memset(tree, 0, sizeof(*tree)); + + init_MUTEX(&tree->tree_lock); + spin_lock_init(&tree->hash_lock); + /* Set the correct compare function */ + tree->sb = sb; + tree->cnid = id; + if (id == HFSPLUS_EXT_CNID) { + tree->keycmp = hfsplus_ext_cmp_key; + } else if (id == HFSPLUS_CAT_CNID) { + tree->keycmp = hfsplus_cat_cmp_key; + } else { + printk("HFS+-fs: unknown B*Tree requested\n"); + goto free_tree; + } + tree->inode = iget(sb, id); + if (!tree->inode) + goto free_tree; + + mapping = tree->inode->i_mapping; + page = read_cache_page(mapping, 0, (filler_t *)mapping->a_ops->readpage, NULL); + if (IS_ERR(page)) + goto free_tree; + + /* 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); + + size = tree->node_size; + if (!size || size & (size - 1)) + 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_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; + + kunmap(page); + page_cache_release(page); + return tree; + + fail_page: + tree->inode->i_mapping->a_ops = &hfsplus_aops; + page_cache_release(page); + free_tree: + iput(tree->inode); + 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)) + printk("HFS+: 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); +} + +void 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; + /* 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); +} + +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; + u16 off, len; + u8 *data, byte, m; + int i; + + while (!tree->free_nodes) { + struct inode *inode = tree->inode; + u32 count; + int res; + + res = hfsplus_file_extend(inode); + if (res) + return ERR_PTR(res); + HFSPLUS_I(inode).phys_size = inode->i_size = + (loff_t)HFSPLUS_I(inode).alloc_blocks << + HFSPLUS_SB(tree->sb).alloc_blksz_shift; + HFSPLUS_I(inode).fs_blocks = HFSPLUS_I(inode).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, &off); + + off += node->page_offset; + pagep = node->page + (off >> PAGE_CACHE_SHIFT); + data = kmap(*pagep); + off &= ~PAGE_CACHE_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); + if (!idx) { + printk("unexpected idx %u (%u)\n", idx, node->this); + BUG(); + } + return hfs_bnode_create(tree, idx); + } + } + } + if (++off >= PAGE_CACHE_SIZE) { + kunmap(*pagep); + data = kmap(*++pagep); + off = 0; + } + idx += 8; + len--; + } + kunmap(*pagep); + nidx = node->next; + if (!nidx) { + printk("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, &off); + off += node->page_offset; + pagep = node->page + (off >> PAGE_CACHE_SHIFT); + data = kmap(*pagep); + off &= ~PAGE_CACHE_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; + + dprint(DBG_BNODE_MOD, "btree_free_node: %u\n", node->this); + if (!node->this) + BUG(); + 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 */; + printk("HFS: 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 */; + printk("HFS: 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_CACHE_SHIFT]; + data = kmap(page); + off &= ~PAGE_CACHE_MASK; + m = 1 << (~nidx & 7); + byte = data[off]; + if (!(byte & m)) { + printk("HFS: 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); +} -- cgit v1.2.3-59-g8ed1b