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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/hfs/bnode.c
downloadlinux-2.6.34-ux500-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2v2.6.12-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!
Diffstat (limited to 'fs/hfs/bnode.c')
-rw-r--r--fs/hfs/bnode.c498
1 files changed, 498 insertions, 0 deletions
diff --git a/fs/hfs/bnode.c b/fs/hfs/bnode.c
new file mode 100644
index 00000000000..6ad1211f84e
--- /dev/null
+++ b/fs/hfs/bnode.c
@@ -0,0 +1,498 @@
+/*
+ * 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/swap.h>
+
+#include "btree.h"
+
+#define REF_PAGES 0
+
+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;
+
+ dprint(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;
+
+ dprint(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;
+
+ dprint(DBG_BNODE_MOD, "bnode: %d\n", node->this);
+ hfs_bnode_read(node, &desc, 0, sizeof(desc));
+ dprint(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);
+ dprint(DBG_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;
+ dprint(DBG_BNODE_MOD, " (%d,%d", tmp, hfs_bnode_read_u8(node, key_off));
+ hfs_bnode_read(node, &cnid, key_off + tmp, 4);
+ dprint(DBG_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);
+ dprint(DBG_BNODE_MOD, " (%d)", tmp);
+ }
+ }
+ dprint(DBG_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("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) {
+ printk("HFS: 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) {
+ printk("HFS: 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 = kmalloc(size, GFP_KERNEL);
+ if (!node)
+ return NULL;
+ memset(node, 0, size);
+ node->tree = tree;
+ node->this = cnid;
+ set_bit(HFS_BNODE_NEW, &node->flags);
+ atomic_set(&node->refcnt, 1);
+ dprint(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_CACHE_SHIFT;
+ node->page_offset = off & ~PAGE_CACHE_MASK;
+ for (i = 0; i < tree->pages_per_bnode; i++) {
+ page = read_cache_page(mapping, block++, (filler_t *)mapping->a_ops->readpage, NULL);
+ if (IS_ERR(page))
+ goto fail;
+ if (PageError(page)) {
+ page_cache_release(page);
+ goto fail;
+ }
+#if !REF_PAGES
+ page_cache_release(page);
+#endif
+ 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;
+
+ dprint(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)
+ ;
+ if (!*p)
+ BUG();
+ *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])
+ // page_cache_release(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)
+ BUG();
+ 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_CACHE_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_CACHE_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);
+#if REF_PAGES
+ {
+ int i;
+ for (i = 0; i < node->tree->pages_per_bnode; i++)
+ get_page(node->page[i]);
+ }
+#endif
+ dprint(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;
+
+ dprint(DBG_BNODE_REFS, "put_node(%d:%d): %d\n",
+ node->tree->cnid, node->this, atomic_read(&node->refcnt));
+ if (!atomic_read(&node->refcnt))
+ BUG();
+ if (!atomic_dec_and_lock(&node->refcnt, &tree->hash_lock)) {
+#if REF_PAGES
+ for (i = 0; i < tree->pages_per_bnode; i++)
+ put_page(node->page[i]);
+#endif
+ return;
+ }
+ for (i = 0; i < tree->pages_per_bnode; i++) {
+ mark_page_accessed(node->page[i]);
+#if REF_PAGES
+ put_page(node->page[i]);
+#endif
+ }
+
+ 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);
+ }
+}