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!
This commit is contained in:
Linus Torvalds
319
fs/hfsplus/btree.c
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319
fs/hfsplus/btree.c
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/*
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* linux/fs/hfsplus/btree.c
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*
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* Copyright (C) 2001
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* Brad Boyer (flar@allandria.com)
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* (C) 2003 Ardis Technologies <roman@ardistech.com>
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*
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* Handle opening/closing btree
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*/
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#include <linux/slab.h>
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#include <linux/pagemap.h>
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#include "hfsplus_fs.h"
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#include "hfsplus_raw.h"
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/* Get a reference to a B*Tree and do some initial checks */
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struct hfs_btree *hfs_btree_open(struct super_block *sb, u32 id)
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{
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struct hfs_btree *tree;
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struct hfs_btree_header_rec *head;
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struct address_space *mapping;
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struct page *page;
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unsigned int size;
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tree = kmalloc(sizeof(*tree), GFP_KERNEL);
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if (!tree)
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return NULL;
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memset(tree, 0, sizeof(*tree));
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init_MUTEX(&tree->tree_lock);
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spin_lock_init(&tree->hash_lock);
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/* Set the correct compare function */
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tree->sb = sb;
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tree->cnid = id;
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if (id == HFSPLUS_EXT_CNID) {
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tree->keycmp = hfsplus_ext_cmp_key;
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} else if (id == HFSPLUS_CAT_CNID) {
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tree->keycmp = hfsplus_cat_cmp_key;
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} else {
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printk("HFS+-fs: unknown B*Tree requested\n");
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goto free_tree;
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}
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tree->inode = iget(sb, id);
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if (!tree->inode)
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goto free_tree;
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mapping = tree->inode->i_mapping;
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page = read_cache_page(mapping, 0, (filler_t *)mapping->a_ops->readpage, NULL);
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if (IS_ERR(page))
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goto free_tree;
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/* Load the header */
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head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
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tree->root = be32_to_cpu(head->root);
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tree->leaf_count = be32_to_cpu(head->leaf_count);
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tree->leaf_head = be32_to_cpu(head->leaf_head);
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tree->leaf_tail = be32_to_cpu(head->leaf_tail);
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tree->node_count = be32_to_cpu(head->node_count);
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tree->free_nodes = be32_to_cpu(head->free_nodes);
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tree->attributes = be32_to_cpu(head->attributes);
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tree->node_size = be16_to_cpu(head->node_size);
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tree->max_key_len = be16_to_cpu(head->max_key_len);
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tree->depth = be16_to_cpu(head->depth);
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size = tree->node_size;
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if (!size || size & (size - 1))
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goto fail_page;
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if (!tree->node_count)
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goto fail_page;
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tree->node_size_shift = ffs(size) - 1;
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tree->pages_per_bnode = (tree->node_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
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kunmap(page);
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page_cache_release(page);
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return tree;
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fail_page:
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tree->inode->i_mapping->a_ops = &hfsplus_aops;
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page_cache_release(page);
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free_tree:
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iput(tree->inode);
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kfree(tree);
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return NULL;
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}
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/* Release resources used by a btree */
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void hfs_btree_close(struct hfs_btree *tree)
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{
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struct hfs_bnode *node;
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int i;
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if (!tree)
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return;
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for (i = 0; i < NODE_HASH_SIZE; i++) {
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while ((node = tree->node_hash[i])) {
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tree->node_hash[i] = node->next_hash;
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if (atomic_read(&node->refcnt))
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printk("HFS+: node %d:%d still has %d user(s)!\n",
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node->tree->cnid, node->this, atomic_read(&node->refcnt));
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hfs_bnode_free(node);
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tree->node_hash_cnt--;
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}
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}
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iput(tree->inode);
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kfree(tree);
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}
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void hfs_btree_write(struct hfs_btree *tree)
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{
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struct hfs_btree_header_rec *head;
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struct hfs_bnode *node;
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struct page *page;
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node = hfs_bnode_find(tree, 0);
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if (IS_ERR(node))
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/* panic? */
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return;
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/* Load the header */
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page = node->page[0];
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head = (struct hfs_btree_header_rec *)(kmap(page) + sizeof(struct hfs_bnode_desc));
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head->root = cpu_to_be32(tree->root);
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head->leaf_count = cpu_to_be32(tree->leaf_count);
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head->leaf_head = cpu_to_be32(tree->leaf_head);
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head->leaf_tail = cpu_to_be32(tree->leaf_tail);
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head->node_count = cpu_to_be32(tree->node_count);
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head->free_nodes = cpu_to_be32(tree->free_nodes);
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head->attributes = cpu_to_be32(tree->attributes);
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head->depth = cpu_to_be16(tree->depth);
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kunmap(page);
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set_page_dirty(page);
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hfs_bnode_put(node);
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}
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static struct hfs_bnode *hfs_bmap_new_bmap(struct hfs_bnode *prev, u32 idx)
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{
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struct hfs_btree *tree = prev->tree;
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struct hfs_bnode *node;
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struct hfs_bnode_desc desc;
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__be32 cnid;
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node = hfs_bnode_create(tree, idx);
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if (IS_ERR(node))
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return node;
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tree->free_nodes--;
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prev->next = idx;
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cnid = cpu_to_be32(idx);
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hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
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node->type = HFS_NODE_MAP;
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node->num_recs = 1;
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hfs_bnode_clear(node, 0, tree->node_size);
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desc.next = 0;
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desc.prev = 0;
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desc.type = HFS_NODE_MAP;
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desc.height = 0;
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desc.num_recs = cpu_to_be16(1);
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desc.reserved = 0;
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hfs_bnode_write(node, &desc, 0, sizeof(desc));
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hfs_bnode_write_u16(node, 14, 0x8000);
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hfs_bnode_write_u16(node, tree->node_size - 2, 14);
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hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6);
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return node;
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}
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struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree)
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{
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struct hfs_bnode *node, *next_node;
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struct page **pagep;
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u32 nidx, idx;
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u16 off, len;
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u8 *data, byte, m;
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int i;
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while (!tree->free_nodes) {
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struct inode *inode = tree->inode;
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u32 count;
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int res;
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res = hfsplus_file_extend(inode);
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if (res)
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return ERR_PTR(res);
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HFSPLUS_I(inode).phys_size = inode->i_size =
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(loff_t)HFSPLUS_I(inode).alloc_blocks <<
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HFSPLUS_SB(tree->sb).alloc_blksz_shift;
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HFSPLUS_I(inode).fs_blocks = HFSPLUS_I(inode).alloc_blocks <<
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HFSPLUS_SB(tree->sb).fs_shift;
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inode_set_bytes(inode, inode->i_size);
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count = inode->i_size >> tree->node_size_shift;
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tree->free_nodes = count - tree->node_count;
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tree->node_count = count;
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}
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nidx = 0;
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node = hfs_bnode_find(tree, nidx);
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if (IS_ERR(node))
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return node;
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len = hfs_brec_lenoff(node, 2, &off);
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off += node->page_offset;
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pagep = node->page + (off >> PAGE_CACHE_SHIFT);
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data = kmap(*pagep);
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off &= ~PAGE_CACHE_MASK;
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idx = 0;
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for (;;) {
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while (len) {
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byte = data[off];
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if (byte != 0xff) {
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for (m = 0x80, i = 0; i < 8; m >>= 1, i++) {
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if (!(byte & m)) {
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idx += i;
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data[off] |= m;
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set_page_dirty(*pagep);
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kunmap(*pagep);
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tree->free_nodes--;
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mark_inode_dirty(tree->inode);
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hfs_bnode_put(node);
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if (!idx) {
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printk("unexpected idx %u (%u)\n", idx, node->this);
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BUG();
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}
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return hfs_bnode_create(tree, idx);
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}
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}
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}
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if (++off >= PAGE_CACHE_SIZE) {
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kunmap(*pagep);
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data = kmap(*++pagep);
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off = 0;
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}
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idx += 8;
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len--;
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}
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kunmap(*pagep);
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nidx = node->next;
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if (!nidx) {
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printk("create new bmap node...\n");
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next_node = hfs_bmap_new_bmap(node, idx);
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} else
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next_node = hfs_bnode_find(tree, nidx);
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hfs_bnode_put(node);
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if (IS_ERR(next_node))
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return next_node;
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node = next_node;
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len = hfs_brec_lenoff(node, 0, &off);
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off += node->page_offset;
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pagep = node->page + (off >> PAGE_CACHE_SHIFT);
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data = kmap(*pagep);
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off &= ~PAGE_CACHE_MASK;
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}
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}
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void hfs_bmap_free(struct hfs_bnode *node)
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{
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struct hfs_btree *tree;
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struct page *page;
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u16 off, len;
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u32 nidx;
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u8 *data, byte, m;
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dprint(DBG_BNODE_MOD, "btree_free_node: %u\n", node->this);
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if (!node->this)
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BUG();
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tree = node->tree;
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nidx = node->this;
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node = hfs_bnode_find(tree, 0);
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if (IS_ERR(node))
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return;
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len = hfs_brec_lenoff(node, 2, &off);
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while (nidx >= len * 8) {
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u32 i;
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nidx -= len * 8;
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i = node->next;
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hfs_bnode_put(node);
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if (!i) {
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/* panic */;
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printk("HFS: unable to free bnode %u. bmap not found!\n", node->this);
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return;
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}
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node = hfs_bnode_find(tree, i);
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if (IS_ERR(node))
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return;
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if (node->type != HFS_NODE_MAP) {
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/* panic */;
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printk("HFS: invalid bmap found! (%u,%d)\n", node->this, node->type);
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hfs_bnode_put(node);
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return;
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}
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len = hfs_brec_lenoff(node, 0, &off);
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}
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off += node->page_offset + nidx / 8;
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page = node->page[off >> PAGE_CACHE_SHIFT];
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data = kmap(page);
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off &= ~PAGE_CACHE_MASK;
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m = 1 << (~nidx & 7);
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byte = data[off];
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if (!(byte & m)) {
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printk("HFS: trying to free free bnode %u(%d)\n", node->this, node->type);
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kunmap(page);
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hfs_bnode_put(node);
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return;
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}
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data[off] = byte & ~m;
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set_page_dirty(page);
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kunmap(page);
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hfs_bnode_put(node);
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tree->free_nodes++;
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mark_inode_dirty(tree->inode);
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}
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