| // 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; |
| 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; |
| } |