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- /*
- * linux/fs/hfs/bnode.c
- *
- * Copyright (C) 2001
- * Brad Boyer (flar@allandria.com)
- * (C) 2003 Ardis Technologies <roman@ardistech.com>
- *
- * Handle basic btree node operations
- */
- #include <linux/pagemap.h>
- #include <linux/slab.h>
- #include <linux/swap.h>
- #include "btree.h"
- void hfs_bnode_read(struct hfs_bnode *node, void *buf,
- int off, int len)
- {
- struct page *page;
- off += node->page_offset;
- page = node->page[0];
- memcpy(buf, kmap(page) + off, len);
- kunmap(page);
- }
- u16 hfs_bnode_read_u16(struct hfs_bnode *node, int off)
- {
- __be16 data;
- // optimize later...
- hfs_bnode_read(node, &data, off, 2);
- return be16_to_cpu(data);
- }
- u8 hfs_bnode_read_u8(struct hfs_bnode *node, int off)
- {
- u8 data;
- // optimize later...
- hfs_bnode_read(node, &data, off, 1);
- return data;
- }
- void hfs_bnode_read_key(struct hfs_bnode *node, void *key, int off)
- {
- struct hfs_btree *tree;
- int key_len;
- tree = node->tree;
- if (node->type == HFS_NODE_LEAF ||
- tree->attributes & HFS_TREE_VARIDXKEYS)
- key_len = hfs_bnode_read_u8(node, off) + 1;
- else
- key_len = tree->max_key_len + 1;
- hfs_bnode_read(node, key, off, key_len);
- }
- void hfs_bnode_write(struct hfs_bnode *node, void *buf, int off, int len)
- {
- struct page *page;
- off += node->page_offset;
- page = node->page[0];
- memcpy(kmap(page) + off, buf, len);
- kunmap(page);
- set_page_dirty(page);
- }
- void hfs_bnode_write_u16(struct hfs_bnode *node, int off, u16 data)
- {
- __be16 v = cpu_to_be16(data);
- // optimize later...
- hfs_bnode_write(node, &v, off, 2);
- }
- void hfs_bnode_write_u8(struct hfs_bnode *node, int off, u8 data)
- {
- // optimize later...
- hfs_bnode_write(node, &data, off, 1);
- }
- void hfs_bnode_clear(struct hfs_bnode *node, int off, int len)
- {
- struct page *page;
- off += node->page_offset;
- page = node->page[0];
- memset(kmap(page) + off, 0, len);
- kunmap(page);
- set_page_dirty(page);
- }
- void hfs_bnode_copy(struct hfs_bnode *dst_node, int dst,
- struct hfs_bnode *src_node, int src, int len)
- {
- struct hfs_btree *tree;
- struct page *src_page, *dst_page;
- hfs_dbg(BNODE_MOD, "copybytes: %u,%u,%u\n", dst, src, len);
- if (!len)
- return;
- tree = src_node->tree;
- src += src_node->page_offset;
- dst += dst_node->page_offset;
- src_page = src_node->page[0];
- dst_page = dst_node->page[0];
- memcpy(kmap(dst_page) + dst, kmap(src_page) + src, len);
- kunmap(src_page);
- kunmap(dst_page);
- set_page_dirty(dst_page);
- }
- void hfs_bnode_move(struct hfs_bnode *node, int dst, int src, int len)
- {
- struct page *page;
- void *ptr;
- hfs_dbg(BNODE_MOD, "movebytes: %u,%u,%u\n", dst, src, len);
- if (!len)
- return;
- src += node->page_offset;
- dst += node->page_offset;
- page = node->page[0];
- ptr = kmap(page);
- memmove(ptr + dst, ptr + src, len);
- kunmap(page);
- set_page_dirty(page);
- }
- void hfs_bnode_dump(struct hfs_bnode *node)
- {
- struct hfs_bnode_desc desc;
- __be32 cnid;
- int i, off, key_off;
- hfs_dbg(BNODE_MOD, "bnode: %d\n", node->this);
- hfs_bnode_read(node, &desc, 0, sizeof(desc));
- hfs_dbg(BNODE_MOD, "%d, %d, %d, %d, %d\n",
- be32_to_cpu(desc.next), be32_to_cpu(desc.prev),
- desc.type, desc.height, be16_to_cpu(desc.num_recs));
- off = node->tree->node_size - 2;
- for (i = be16_to_cpu(desc.num_recs); i >= 0; off -= 2, i--) {
- key_off = hfs_bnode_read_u16(node, off);
- hfs_dbg_cont(BNODE_MOD, " %d", key_off);
- if (i && node->type == HFS_NODE_INDEX) {
- int tmp;
- if (node->tree->attributes & HFS_TREE_VARIDXKEYS)
- tmp = (hfs_bnode_read_u8(node, key_off) | 1) + 1;
- else
- tmp = node->tree->max_key_len + 1;
- hfs_dbg_cont(BNODE_MOD, " (%d,%d",
- tmp, hfs_bnode_read_u8(node, key_off));
- hfs_bnode_read(node, &cnid, key_off + tmp, 4);
- hfs_dbg_cont(BNODE_MOD, ",%d)", be32_to_cpu(cnid));
- } else if (i && node->type == HFS_NODE_LEAF) {
- int tmp;
- tmp = hfs_bnode_read_u8(node, key_off);
- hfs_dbg_cont(BNODE_MOD, " (%d)", tmp);
- }
- }
- hfs_dbg_cont(BNODE_MOD, "\n");
- }
- void hfs_bnode_unlink(struct hfs_bnode *node)
- {
- struct hfs_btree *tree;
- struct hfs_bnode *tmp;
- __be32 cnid;
- tree = node->tree;
- if (node->prev) {
- tmp = hfs_bnode_find(tree, node->prev);
- if (IS_ERR(tmp))
- return;
- tmp->next = node->next;
- cnid = cpu_to_be32(tmp->next);
- hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
- hfs_bnode_put(tmp);
- } else if (node->type == HFS_NODE_LEAF)
- tree->leaf_head = node->next;
- if (node->next) {
- tmp = hfs_bnode_find(tree, node->next);
- if (IS_ERR(tmp))
- return;
- tmp->prev = node->prev;
- cnid = cpu_to_be32(tmp->prev);
- hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, prev), 4);
- hfs_bnode_put(tmp);
- } else if (node->type == HFS_NODE_LEAF)
- tree->leaf_tail = node->prev;
- // move down?
- if (!node->prev && !node->next) {
- printk(KERN_DEBUG "hfs_btree_del_level\n");
- }
- if (!node->parent) {
- tree->root = 0;
- tree->depth = 0;
- }
- set_bit(HFS_BNODE_DELETED, &node->flags);
- }
- static inline int hfs_bnode_hash(u32 num)
- {
- num = (num >> 16) + num;
- num += num >> 8;
- return num & (NODE_HASH_SIZE - 1);
- }
- struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *tree, u32 cnid)
- {
- struct hfs_bnode *node;
- if (cnid >= tree->node_count) {
- pr_err("request for non-existent node %d in B*Tree\n", cnid);
- return NULL;
- }
- for (node = tree->node_hash[hfs_bnode_hash(cnid)];
- node; node = node->next_hash) {
- if (node->this == cnid) {
- return node;
- }
- }
- return NULL;
- }
- static struct hfs_bnode *__hfs_bnode_create(struct hfs_btree *tree, u32 cnid)
- {
- struct super_block *sb;
- struct hfs_bnode *node, *node2;
- struct address_space *mapping;
- struct page *page;
- int size, block, i, hash;
- loff_t off;
- if (cnid >= tree->node_count) {
- pr_err("request for non-existent node %d in B*Tree\n", cnid);
- return NULL;
- }
- sb = tree->inode->i_sb;
- size = sizeof(struct hfs_bnode) + tree->pages_per_bnode *
- sizeof(struct page *);
- node = kzalloc(size, GFP_KERNEL);
- if (!node)
- return NULL;
- node->tree = tree;
- node->this = cnid;
- set_bit(HFS_BNODE_NEW, &node->flags);
- atomic_set(&node->refcnt, 1);
- hfs_dbg(BNODE_REFS, "new_node(%d:%d): 1\n",
- node->tree->cnid, node->this);
- init_waitqueue_head(&node->lock_wq);
- spin_lock(&tree->hash_lock);
- node2 = hfs_bnode_findhash(tree, cnid);
- if (!node2) {
- hash = hfs_bnode_hash(cnid);
- node->next_hash = tree->node_hash[hash];
- tree->node_hash[hash] = node;
- tree->node_hash_cnt++;
- } else {
- spin_unlock(&tree->hash_lock);
- kfree(node);
- wait_event(node2->lock_wq, !test_bit(HFS_BNODE_NEW, &node2->flags));
- return node2;
- }
- spin_unlock(&tree->hash_lock);
- mapping = tree->inode->i_mapping;
- off = (loff_t)cnid * tree->node_size;
- block = off >> PAGE_SHIFT;
- node->page_offset = off & ~PAGE_MASK;
- for (i = 0; i < tree->pages_per_bnode; i++) {
- page = read_mapping_page(mapping, block++, NULL);
- if (IS_ERR(page))
- goto fail;
- if (PageError(page)) {
- put_page(page);
- goto fail;
- }
- node->page[i] = page;
- }
- return node;
- fail:
- set_bit(HFS_BNODE_ERROR, &node->flags);
- return node;
- }
- void hfs_bnode_unhash(struct hfs_bnode *node)
- {
- struct hfs_bnode **p;
- hfs_dbg(BNODE_REFS, "remove_node(%d:%d): %d\n",
- node->tree->cnid, node->this, atomic_read(&node->refcnt));
- for (p = &node->tree->node_hash[hfs_bnode_hash(node->this)];
- *p && *p != node; p = &(*p)->next_hash)
- ;
- BUG_ON(!*p);
- *p = node->next_hash;
- node->tree->node_hash_cnt--;
- }
- /* Load a particular node out of a tree */
- struct hfs_bnode *hfs_bnode_find(struct hfs_btree *tree, u32 num)
- {
- struct hfs_bnode *node;
- struct hfs_bnode_desc *desc;
- int i, rec_off, off, next_off;
- int entry_size, key_size;
- spin_lock(&tree->hash_lock);
- node = hfs_bnode_findhash(tree, num);
- if (node) {
- hfs_bnode_get(node);
- spin_unlock(&tree->hash_lock);
- wait_event(node->lock_wq, !test_bit(HFS_BNODE_NEW, &node->flags));
- if (test_bit(HFS_BNODE_ERROR, &node->flags))
- goto node_error;
- return node;
- }
- spin_unlock(&tree->hash_lock);
- node = __hfs_bnode_create(tree, num);
- if (!node)
- return ERR_PTR(-ENOMEM);
- if (test_bit(HFS_BNODE_ERROR, &node->flags))
- goto node_error;
- if (!test_bit(HFS_BNODE_NEW, &node->flags))
- return node;
- desc = (struct hfs_bnode_desc *)(kmap(node->page[0]) + node->page_offset);
- node->prev = be32_to_cpu(desc->prev);
- node->next = be32_to_cpu(desc->next);
- node->num_recs = be16_to_cpu(desc->num_recs);
- node->type = desc->type;
- node->height = desc->height;
- kunmap(node->page[0]);
- switch (node->type) {
- case HFS_NODE_HEADER:
- case HFS_NODE_MAP:
- if (node->height != 0)
- goto node_error;
- break;
- case HFS_NODE_LEAF:
- if (node->height != 1)
- goto node_error;
- break;
- case HFS_NODE_INDEX:
- if (node->height <= 1 || node->height > tree->depth)
- goto node_error;
- break;
- default:
- goto node_error;
- }
- rec_off = tree->node_size - 2;
- off = hfs_bnode_read_u16(node, rec_off);
- if (off != sizeof(struct hfs_bnode_desc))
- goto node_error;
- for (i = 1; i <= node->num_recs; off = next_off, i++) {
- rec_off -= 2;
- next_off = hfs_bnode_read_u16(node, rec_off);
- if (next_off <= off ||
- next_off > tree->node_size ||
- next_off & 1)
- goto node_error;
- entry_size = next_off - off;
- if (node->type != HFS_NODE_INDEX &&
- node->type != HFS_NODE_LEAF)
- continue;
- key_size = hfs_bnode_read_u8(node, off) + 1;
- if (key_size >= entry_size /*|| key_size & 1*/)
- goto node_error;
- }
- clear_bit(HFS_BNODE_NEW, &node->flags);
- wake_up(&node->lock_wq);
- return node;
- node_error:
- set_bit(HFS_BNODE_ERROR, &node->flags);
- clear_bit(HFS_BNODE_NEW, &node->flags);
- wake_up(&node->lock_wq);
- hfs_bnode_put(node);
- return ERR_PTR(-EIO);
- }
- void hfs_bnode_free(struct hfs_bnode *node)
- {
- int i;
- for (i = 0; i < node->tree->pages_per_bnode; i++)
- if (node->page[i])
- put_page(node->page[i]);
- kfree(node);
- }
- struct hfs_bnode *hfs_bnode_create(struct hfs_btree *tree, u32 num)
- {
- struct hfs_bnode *node;
- struct page **pagep;
- int i;
- spin_lock(&tree->hash_lock);
- node = hfs_bnode_findhash(tree, num);
- spin_unlock(&tree->hash_lock);
- if (node) {
- pr_crit("new node %u already hashed?\n", num);
- WARN_ON(1);
- return node;
- }
- node = __hfs_bnode_create(tree, num);
- if (!node)
- return ERR_PTR(-ENOMEM);
- if (test_bit(HFS_BNODE_ERROR, &node->flags)) {
- hfs_bnode_put(node);
- return ERR_PTR(-EIO);
- }
- pagep = node->page;
- memset(kmap(*pagep) + node->page_offset, 0,
- min((int)PAGE_SIZE, (int)tree->node_size));
- set_page_dirty(*pagep);
- kunmap(*pagep);
- for (i = 1; i < tree->pages_per_bnode; i++) {
- memset(kmap(*++pagep), 0, PAGE_SIZE);
- set_page_dirty(*pagep);
- kunmap(*pagep);
- }
- clear_bit(HFS_BNODE_NEW, &node->flags);
- wake_up(&node->lock_wq);
- return node;
- }
- void hfs_bnode_get(struct hfs_bnode *node)
- {
- if (node) {
- atomic_inc(&node->refcnt);
- hfs_dbg(BNODE_REFS, "get_node(%d:%d): %d\n",
- node->tree->cnid, node->this,
- atomic_read(&node->refcnt));
- }
- }
- /* Dispose of resources used by a node */
- void hfs_bnode_put(struct hfs_bnode *node)
- {
- if (node) {
- struct hfs_btree *tree = node->tree;
- int i;
- hfs_dbg(BNODE_REFS, "put_node(%d:%d): %d\n",
- node->tree->cnid, node->this,
- atomic_read(&node->refcnt));
- BUG_ON(!atomic_read(&node->refcnt));
- if (!atomic_dec_and_lock(&node->refcnt, &tree->hash_lock))
- return;
- for (i = 0; i < tree->pages_per_bnode; i++) {
- if (!node->page[i])
- continue;
- mark_page_accessed(node->page[i]);
- }
- if (test_bit(HFS_BNODE_DELETED, &node->flags)) {
- hfs_bnode_unhash(node);
- spin_unlock(&tree->hash_lock);
- hfs_bmap_free(node);
- hfs_bnode_free(node);
- return;
- }
- spin_unlock(&tree->hash_lock);
- }
- }
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