--- /dev/null
+/*
+ * linux/fs/hfsplus/bnode.c
+ *
+ * Copyright (C) 2001
+ * Brad Boyer (flar@allandria.com)
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ *
+ * Handle basic btree node operations
+ */
+
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/pagemap.h>
+#include <linux/fs.h>
+#include <linux/swap.h>
+
+#include "hfsplus_fs.h"
+#include "hfsplus_raw.h"
+
+/* Copy a specified range of bytes from the raw data of a node */
+void hfs_bnode_read(struct hfs_bnode *node, void *buf, int off, int len)
+{
+ struct page **pagep;
+ int l;
+
+ off += node->page_offset;
+ pagep = node->page + (off >> PAGE_CACHE_SHIFT);
+ off &= ~PAGE_CACHE_MASK;
+
+ l = min_t(int, len, PAGE_CACHE_SIZE - off);
+ memcpy(buf, kmap(*pagep) + off, l);
+ kunmap(*pagep);
+
+ while ((len -= l) != 0) {
+ buf += l;
+ l = min_t(int, len, PAGE_CACHE_SIZE);
+ memcpy(buf, kmap(*++pagep), l);
+ kunmap(*pagep);
+ }
+}
+
+u16 hfs_bnode_read_u16(struct hfs_bnode *node, int off)
+{
+ __be16 data;
+ /* TODO: 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;
+ /* TODO: 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 ||
+ node->tree->cnid == HFSPLUS_ATTR_CNID)
+ key_len = hfs_bnode_read_u16(node, off) + 2;
+ else
+ key_len = tree->max_key_len + 2;
+
+ hfs_bnode_read(node, key, off, key_len);
+}
+
+void hfs_bnode_write(struct hfs_bnode *node, void *buf, int off, int len)
+{
+ struct page **pagep;
+ int l;
+
+ off += node->page_offset;
+ pagep = node->page + (off >> PAGE_CACHE_SHIFT);
+ off &= ~PAGE_CACHE_MASK;
+
+ l = min_t(int, len, PAGE_CACHE_SIZE - off);
+ memcpy(kmap(*pagep) + off, buf, l);
+ set_page_dirty(*pagep);
+ kunmap(*pagep);
+
+ while ((len -= l) != 0) {
+ buf += l;
+ l = min_t(int, len, PAGE_CACHE_SIZE);
+ memcpy(kmap(*++pagep), buf, l);
+ set_page_dirty(*pagep);
+ kunmap(*pagep);
+ }
+}
+
+void hfs_bnode_write_u16(struct hfs_bnode *node, int off, u16 data)
+{
+ __be16 v = cpu_to_be16(data);
+ /* TODO: optimize later... */
+ hfs_bnode_write(node, &v, off, 2);
+}
+
+void hfs_bnode_clear(struct hfs_bnode *node, int off, int len)
+{
+ struct page **pagep;
+ int l;
+
+ off += node->page_offset;
+ pagep = node->page + (off >> PAGE_CACHE_SHIFT);
+ off &= ~PAGE_CACHE_MASK;
+
+ l = min_t(int, len, PAGE_CACHE_SIZE - off);
+ memset(kmap(*pagep) + off, 0, l);
+ set_page_dirty(*pagep);
+ kunmap(*pagep);
+
+ while ((len -= l) != 0) {
+ l = min_t(int, len, PAGE_CACHE_SIZE);
+ memset(kmap(*++pagep), 0, l);
+ set_page_dirty(*pagep);
+ kunmap(*pagep);
+ }
+}
+
+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;
+ int l;
+
+ 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 + (src >> PAGE_CACHE_SHIFT);
+ src &= ~PAGE_CACHE_MASK;
+ dst_page = dst_node->page + (dst >> PAGE_CACHE_SHIFT);
+ dst &= ~PAGE_CACHE_MASK;
+
+ if (src == dst) {
+ l = min_t(int, len, PAGE_CACHE_SIZE - src);
+ memcpy(kmap(*dst_page) + src, kmap(*src_page) + src, l);
+ kunmap(*src_page);
+ set_page_dirty(*dst_page);
+ kunmap(*dst_page);
+
+ while ((len -= l) != 0) {
+ l = min_t(int, len, PAGE_CACHE_SIZE);
+ memcpy(kmap(*++dst_page), kmap(*++src_page), l);
+ kunmap(*src_page);
+ set_page_dirty(*dst_page);
+ kunmap(*dst_page);
+ }
+ } else {
+ void *src_ptr, *dst_ptr;
+
+ do {
+ src_ptr = kmap(*src_page) + src;
+ dst_ptr = kmap(*dst_page) + dst;
+ if (PAGE_CACHE_SIZE - src < PAGE_CACHE_SIZE - dst) {
+ l = PAGE_CACHE_SIZE - src;
+ src = 0;
+ dst += l;
+ } else {
+ l = PAGE_CACHE_SIZE - dst;
+ src += l;
+ dst = 0;
+ }
+ l = min(len, l);
+ memcpy(dst_ptr, src_ptr, l);
+ kunmap(*src_page);
+ set_page_dirty(*dst_page);
+ kunmap(*dst_page);
+ if (!dst)
+ dst_page++;
+ else
+ src_page++;
+ } while ((len -= l));
+ }
+}
+
+void hfs_bnode_move(struct hfs_bnode *node, int dst, int src, int len)
+{
+ struct page **src_page, **dst_page;
+ int l;
+
+ hfs_dbg(BNODE_MOD, "movebytes: %u,%u,%u\n", dst, src, len);
+ if (!len)
+ return;
+ src += node->page_offset;
+ dst += node->page_offset;
+ if (dst > src) {
+ src += len - 1;
+ src_page = node->page + (src >> PAGE_CACHE_SHIFT);
+ src = (src & ~PAGE_CACHE_MASK) + 1;
+ dst += len - 1;
+ dst_page = node->page + (dst >> PAGE_CACHE_SHIFT);
+ dst = (dst & ~PAGE_CACHE_MASK) + 1;
+
+ if (src == dst) {
+ while (src < len) {
+ memmove(kmap(*dst_page), kmap(*src_page), src);
+ kunmap(*src_page);
+ set_page_dirty(*dst_page);
+ kunmap(*dst_page);
+ len -= src;
+ src = PAGE_CACHE_SIZE;
+ src_page--;
+ dst_page--;
+ }
+ src -= len;
+ memmove(kmap(*dst_page) + src,
+ kmap(*src_page) + src, len);
+ kunmap(*src_page);
+ set_page_dirty(*dst_page);
+ kunmap(*dst_page);
+ } else {
+ void *src_ptr, *dst_ptr;
+
+ do {
+ src_ptr = kmap(*src_page) + src;
+ dst_ptr = kmap(*dst_page) + dst;
+ if (src < dst) {
+ l = src;
+ src = PAGE_CACHE_SIZE;
+ dst -= l;
+ } else {
+ l = dst;
+ src -= l;
+ dst = PAGE_CACHE_SIZE;
+ }
+ l = min(len, l);
+ memmove(dst_ptr - l, src_ptr - l, l);
+ kunmap(*src_page);
+ set_page_dirty(*dst_page);
+ kunmap(*dst_page);
+ if (dst == PAGE_CACHE_SIZE)
+ dst_page--;
+ else
+ src_page--;
+ } while ((len -= l));
+ }
+ } else {
+ src_page = node->page + (src >> PAGE_CACHE_SHIFT);
+ src &= ~PAGE_CACHE_MASK;
+ dst_page = node->page + (dst >> PAGE_CACHE_SHIFT);
+ dst &= ~PAGE_CACHE_MASK;
+
+ if (src == dst) {
+ l = min_t(int, len, PAGE_CACHE_SIZE - src);
+ memmove(kmap(*dst_page) + src,
+ kmap(*src_page) + src, l);
+ kunmap(*src_page);
+ set_page_dirty(*dst_page);
+ kunmap(*dst_page);
+
+ while ((len -= l) != 0) {
+ l = min_t(int, len, PAGE_CACHE_SIZE);
+ memmove(kmap(*++dst_page),
+ kmap(*++src_page), l);
+ kunmap(*src_page);
+ set_page_dirty(*dst_page);
+ kunmap(*dst_page);
+ }
+ } else {
+ void *src_ptr, *dst_ptr;
+
+ do {
+ src_ptr = kmap(*src_page) + src;
+ dst_ptr = kmap(*dst_page) + dst;
+ if (PAGE_CACHE_SIZE - src <
+ PAGE_CACHE_SIZE - dst) {
+ l = PAGE_CACHE_SIZE - src;
+ src = 0;
+ dst += l;
+ } else {
+ l = PAGE_CACHE_SIZE - dst;
+ src += l;
+ dst = 0;
+ }
+ l = min(len, l);
+ memmove(dst_ptr, src_ptr, l);
+ kunmap(*src_page);
+ set_page_dirty(*dst_page);
+ kunmap(*dst_page);
+ if (!dst)
+ dst_page++;
+ else
+ src_page++;
+ } while ((len -= l));
+ }
+ }
+}
+
+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(BNODE_MOD, " %d", key_off);
+ if (i && node->type == HFS_NODE_INDEX) {
+ int tmp;
+
+ if (node->tree->attributes & HFS_TREE_VARIDXKEYS ||
+ node->tree->cnid == HFSPLUS_ATTR_CNID)
+ tmp = hfs_bnode_read_u16(node, key_off) + 2;
+ else
+ tmp = node->tree->max_key_len + 2;
+ hfs_dbg_cont(BNODE_MOD, " (%d", tmp);
+ 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_u16(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)
+ hfs_dbg(BNODE_MOD, "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_shift;
+ block = off >> PAGE_CACHE_SHIFT;
+ node->page_offset = off & ~PAGE_CACHE_MASK;
+ for (i = 0; i < tree->pages_per_bnode; block++, i++) {
+ page = read_mapping_page(mapping, block, NULL);
+ if (IS_ERR(page))
+ goto fail;
+ if (PageError(page)) {
+ page_cache_release(page);
+ goto fail;
+ }
+ page_cache_release(page);
+ 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_u16(node, off) + 2;
+ 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)
+{
+#if 0
+ int i;
+
+ for (i = 0; i < node->tree->pages_per_bnode; i++)
+ if (node->page[i])
+ page_cache_release(node->page[i]);
+#endif
+ 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_t(int, PAGE_CACHE_SIZE, 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);
+ 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);
+ if (hfs_bnode_need_zeroout(tree))
+ hfs_bnode_clear(node, 0, tree->node_size);
+ hfs_bmap_free(node);
+ hfs_bnode_free(node);
+ return;
+ }
+ spin_unlock(&tree->hash_lock);
+ }
+}
+
+/*
+ * Unused nodes have to be zeroed if this is the catalog tree and
+ * a corresponding flag in the volume header is set.
+ */
+bool hfs_bnode_need_zeroout(struct hfs_btree *tree)
+{
+ struct super_block *sb = tree->inode->i_sb;
+ struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
+ const u32 volume_attr = be32_to_cpu(sbi->s_vhdr->attributes);
+
+ return tree->cnid == HFSPLUS_CAT_CNID &&
+ volume_attr & HFSPLUS_VOL_UNUSED_NODE_FIX;
+}
Code Review / kvmfornfv.git / blobdiff