diff options
Diffstat (limited to 'fs/hfsplus/bnode.c')
| -rw-r--r-- | fs/hfsplus/bnode.c | 665 |
1 files changed, 665 insertions, 0 deletions
diff --git a/fs/hfsplus/bnode.c b/fs/hfsplus/bnode.c new file mode 100644 index 000000000..177fae4e6 --- /dev/null +++ b/fs/hfsplus/bnode.c @@ -0,0 +1,665 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * 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_SHIFT); + off &= ~PAGE_MASK; + + l = min_t(int, len, PAGE_SIZE - off); + memcpy(buf, kmap(*pagep) + off, l); + kunmap(*pagep); + + while ((len -= l) != 0) { + buf += l; + l = min_t(int, len, PAGE_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_SHIFT); + off &= ~PAGE_MASK; + + l = min_t(int, len, PAGE_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_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_SHIFT); + off &= ~PAGE_MASK; + + l = min_t(int, len, PAGE_SIZE - off); + memset(kmap(*pagep) + off, 0, l); + set_page_dirty(*pagep); + kunmap(*pagep); + + while ((len -= l) != 0) { + l = min_t(int, len, PAGE_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 page **src_page, **dst_page; + int l; + + hfs_dbg(BNODE_MOD, "copybytes: %u,%u,%u\n", dst, src, len); + if (!len) + return; + src += src_node->page_offset; + dst += dst_node->page_offset; + src_page = src_node->page + (src >> PAGE_SHIFT); + src &= ~PAGE_MASK; + dst_page = dst_node->page + (dst >> PAGE_SHIFT); + dst &= ~PAGE_MASK; + + if (src == dst) { + l = min_t(int, len, PAGE_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_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_SIZE - src < PAGE_SIZE - dst) { + l = PAGE_SIZE - src; + src = 0; + dst += l; + } else { + l = PAGE_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_SHIFT); + src = (src & ~PAGE_MASK) + 1; + dst += len - 1; + dst_page = node->page + (dst >> PAGE_SHIFT); + dst = (dst & ~PAGE_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_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_SIZE; + dst -= l; + } else { + l = dst; + src -= l; + dst = PAGE_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_SIZE) + dst_page--; + else + src_page--; + } while ((len -= l)); + } + } else { + src_page = node->page + (src >> PAGE_SHIFT); + src &= ~PAGE_MASK; + dst_page = node->page + (dst >> PAGE_SHIFT); + dst &= ~PAGE_MASK; + + if (src == dst) { + l = min_t(int, len, PAGE_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_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_SIZE - src < + PAGE_SIZE - dst) { + l = PAGE_SIZE - src; + src = 0; + dst += l; + } else { + l = PAGE_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 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; + } + + 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_SHIFT; + node->page_offset = off & ~PAGE_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)) { + 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_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) +{ + 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_t(int, PAGE_SIZE, 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); + 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; +} |