--- /dev/null
+/*
+ * linux/fs/hfs/btree.c
+ *
+ * Copyright (C) 2001
+ * Brad Boyer (flar@allandria.com)
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ *
+ * Handle opening/closing btree
+ */
+
+#include <linux/pagemap.h>
+#include <linux/slab.h>
+#include <linux/log2.h>
+
+#include "btree.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, btree_keycmp keycmp)
+{
+ struct hfs_btree *tree;
+ struct hfs_btree_header_rec *head;
+ struct address_space *mapping;
+ 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);
+ /* Set the correct compare function */
+ tree->sb = sb;
+ tree->cnid = id;
+ tree->keycmp = keycmp;
+
+ tree->inode = iget_locked(sb, id);
+ if (!tree->inode)
+ goto free_tree;
+ BUG_ON(!(tree->inode->i_state & I_NEW));
+ {
+ struct hfs_mdb *mdb = HFS_SB(sb)->mdb;
+ HFS_I(tree->inode)->flags = 0;
+ mutex_init(&HFS_I(tree->inode)->extents_lock);
+ switch (id) {
+ case HFS_EXT_CNID:
+ hfs_inode_read_fork(tree->inode, mdb->drXTExtRec, mdb->drXTFlSize,
+ mdb->drXTFlSize, be32_to_cpu(mdb->drXTClpSiz));
+ if (HFS_I(tree->inode)->alloc_blocks >
+ HFS_I(tree->inode)->first_blocks) {
+ pr_err("invalid btree extent records\n");
+ unlock_new_inode(tree->inode);
+ goto free_inode;
+ }
+
+ tree->inode->i_mapping->a_ops = &hfs_btree_aops;
+ break;
+ case HFS_CAT_CNID:
+ hfs_inode_read_fork(tree->inode, mdb->drCTExtRec, mdb->drCTFlSize,
+ mdb->drCTFlSize, be32_to_cpu(mdb->drCTClpSiz));
+
+ if (!HFS_I(tree->inode)->first_blocks) {
+ pr_err("invalid btree extent records (0 size)\n");
+ unlock_new_inode(tree->inode);
+ goto free_inode;
+ }
+
+ tree->inode->i_mapping->a_ops = &hfs_btree_aops;
+ break;
+ default:
+ BUG();
+ }
+ }
+ unlock_new_inode(tree->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);
+
+ size = tree->node_size;
+ if (!is_power_of_2(size))
+ goto fail_page;
+ if (!tree->node_count)
+ goto fail_page;
+ switch (id) {
+ case HFS_EXT_CNID:
+ if (tree->max_key_len != HFS_MAX_EXT_KEYLEN) {
+ pr_err("invalid extent max_key_len %d\n",
+ tree->max_key_len);
+ goto fail_page;
+ }
+ break;
+ case HFS_CAT_CNID:
+ if (tree->max_key_len != HFS_MAX_CAT_KEYLEN) {
+ pr_err("invalid catalog max_key_len %d\n",
+ tree->max_key_len);
+ goto fail_page;
+ }
+ break;
+ default:
+ BUG();
+ }
+
+ 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:
+ page_cache_release(page);
+free_inode:
+ tree->inode->i_mapping->a_ops = &hfs_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_err("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;
+
+ if (!tree->free_nodes)
+ panic("FIXME!!!");
+ 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;
+ u32 count;
+ int res;
+
+ res = hfs_extend_file(inode);
+ if (res)
+ return ERR_PTR(res);
+ HFS_I(inode)->phys_size = inode->i_size =
+ (loff_t)HFS_I(inode)->alloc_blocks *
+ HFS_SB(tree->sb)->alloc_blksz;
+ HFS_I(inode)->fs_blocks = inode->i_size >>
+ tree->sb->s_blocksize_bits;
+ 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_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);
+ 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(KERN_DEBUG "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_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;
+
+ hfs_dbg(BNODE_MOD, "btree_free_node: %u\n", 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_CACHE_SHIFT];
+ data = kmap(page);
+ off &= ~PAGE_CACHE_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);
+}
Code Review / kvmfornfv.git / blobdiff