001-squashfs.patch

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+			ERROR("Failed to allocate meta_index\n");
+			goto failed;
+		}
+		for(i = 0; i < SQUASHFS_META_NUMBER; i++) {
+			msblk->meta_index[i].inode_number = 0;
+			msblk->meta_index[i].locked = 0;
+		}
+		msblk->next_meta_index = 0;
+	}
+
+	for(i = SQUASHFS_META_NUMBER; i &&
+			msblk->meta_index[msblk->next_meta_index].locked; i --)
+		msblk->next_meta_index = (msblk->next_meta_index + 1) %
+			SQUASHFS_META_NUMBER;
+
+	if(i == 0) {
+		TRACE("empty_meta_index: failed!\n");
+		goto failed;
+	}
+
+	TRACE("empty_meta_index: returned meta entry %d, %p\n",
+			msblk->next_meta_index,
+			&msblk->meta_index[msblk->next_meta_index]);
+
+	meta = &msblk->meta_index[msblk->next_meta_index];
+	msblk->next_meta_index = (msblk->next_meta_index + 1) %
+			SQUASHFS_META_NUMBER;
+
+	meta->inode_number = inode->i_ino;
+	meta->offset = offset;
+	meta->skip = skip;
+	meta->entries = 0;
+	meta->locked = 1;
+
+failed:
+	up(&msblk->meta_index_mutex);
+	return meta;
+}
+
+
+void release_meta_index(struct inode *inode, struct meta_index *meta)
+{
+	meta->locked = 0;
+}
+
+
+static int read_block_index(struct super_block *s, int blocks, char *block_list,
+		long long *start_block, int *offset)
+{
+	struct squashfs_sb_info *msblk = s->s_fs_info;
+	unsigned int *block_listp;
+	int block = 0;
+
+	if (msblk->swap) {
+		char sblock_list[blocks << 2];
+
+		if (!squashfs_get_cached_block(s, sblock_list, *start_block,
+				*offset, blocks << 2, start_block, offset)) {
+			ERROR("Unable to read block list [%llx:%x]\n",
+				*start_block, *offset);
+			goto failure;
+		}
+		SQUASHFS_SWAP_INTS(((unsigned int *)block_list),
+				((unsigned int *)sblock_list), blocks);
+	} else
+		if (!squashfs_get_cached_block(s, block_list, *start_block,
+				*offset, blocks << 2, start_block, offset)) {
+			ERROR("Unable to read block list [%llx:%x]\n",
+				*start_block, *offset);
+			goto failure;
+		}
+
+	for (block_listp = (unsigned int *) block_list; blocks;
+				block_listp++, blocks --)
+		block += SQUASHFS_COMPRESSED_SIZE_BLOCK(*block_listp);
+
+	return block;
+
+failure:
+	return -1;
+}
+
+
+#define SIZE 256
+
+static inline int calculate_skip(int blocks) {
+	int skip = (blocks - 1) / ((SQUASHFS_SLOTS * SQUASHFS_META_ENTRIES + 1) * SQUASHFS_META_INDEXES);
+	return skip >= 7 ? 7 : skip + 1;
+}
+
+
+static int get_meta_index(struct inode *inode, int index,
+		long long *index_block, int *index_offset,
+		long long *data_block, char *block_list)
+{
+	struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
+	struct squashfs_super_block *sblk = &msblk->sblk;
+	int skip = calculate_skip(i_size_read(inode) >> sblk->block_log);
+	int offset = 0;
+	struct meta_index *meta;
+	struct meta_entry *meta_entry;
+	long long cur_index_block = SQUASHFS_I(inode)->u.s1.block_list_start;
+	int cur_offset = SQUASHFS_I(inode)->offset;
+	long long cur_data_block = SQUASHFS_I(inode)->start_block;
+	int i;
+
+	index /= SQUASHFS_META_INDEXES * skip;
+
+	while ( offset < index ) {
+		meta = locate_meta_index(inode, index, offset + 1);
+
+		if (meta == NULL) {
+			if ((meta = empty_meta_index(inode, offset + 1,
+							skip)) == NULL)
+				goto all_done;
+		} else {
+			offset = index < meta->offset + meta->entries ? index :
+				meta->offset + meta->entries - 1;
+			meta_entry = &meta->meta_entry[offset - meta->offset];
+			cur_index_block = meta_entry->index_block + sblk->inode_table_start;
+			cur_offset = meta_entry->offset;
+			cur_data_block = meta_entry->data_block;
+			TRACE("get_meta_index: offset %d, meta->offset %d, "
+				"meta->entries %d\n", offset, meta->offset,
+				meta->entries);
+			TRACE("get_meta_index: index_block 0x%llx, offset 0x%x"
+				" data_block 0x%llx\n", cur_index_block,
+				cur_offset, cur_data_block);
+		}
+
+		for (i = meta->offset + meta->entries; i <= index &&
+				i < meta->offset + SQUASHFS_META_ENTRIES; i++) {
+			int blocks = skip * SQUASHFS_META_INDEXES;
+
+			while (blocks) {
+				int block = blocks > (SIZE >> 2) ? (SIZE >> 2) :
+					blocks;
+				int res = read_block_index(inode->i_sb, block,
+					block_list, &cur_index_block,
+					&cur_offset);
+
+				if (res == -1)
+					goto failed;
+
+				cur_data_block += res;
+				blocks -= block;
+			}
+
+			meta_entry = &meta->meta_entry[i - meta->offset];
+			meta_entry->index_block = cur_index_block - sblk->inode_table_start;
+			meta_entry->offset = cur_offset;
+			meta_entry->data_block = cur_data_block;
+			meta->entries ++;
+			offset ++;
+		}
+
+		TRACE("get_meta_index: meta->offset %d, meta->entries %d\n",
+				meta->offset, meta->entries);
+
+		release_meta_index(inode, meta);
+	}
+
+all_done:
+	*index_block = cur_index_block;
+	*index_offset = cur_offset;
+	*data_block = cur_data_block;
+
+	return offset * SQUASHFS_META_INDEXES * skip;
+
+failed:
+	release_meta_index(inode, meta);
+	return -1;
+}
+
+
+static long long read_blocklist(struct inode *inode, int index,
+				int readahead_blks, char *block_list,
+				unsigned short **block_p, unsigned int *bsize)
+{
+	long long block_ptr;
+	int offset;
+	long long block;
+	int res = get_meta_index(inode, index, &block_ptr, &offset, &block,
+		block_list);
+
+	TRACE("read_blocklist: res %d, index %d, block_ptr 0x%llx, offset"
+		       " 0x%x, block 0x%llx\n", res, index, block_ptr, offset,
+		       block);
+
+	if(res == -1)
+		goto failure;
+
+	index -= res;
+
+	while ( index ) {
+		int blocks = index > (SIZE >> 2) ? (SIZE >> 2) : index;
+		int res = read_block_index(inode->i_sb, blocks, block_list,
+			&block_ptr, &offset);
+		if (res == -1)
+			goto failure;
+		block += res;
+		index -= blocks;
+	}
+
+	if (read_block_index(inode->i_sb, 1, block_list,
+			&block_ptr, &offset) == -1)
+		goto failure;
+	*bsize = *((unsigned int *) block_list);
+
+	return block;
+
+failure:
+	return 0;
+}
+
+
+static int squashfs_readpage(struct file *file, struct page *page)
+{
+	struct inode *inode = page->mapping->host;
+	struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
+	struct squashfs_super_block *sblk = &msblk->sblk;
+	unsigned char block_list[SIZE];
+	long long block;
+	unsigned int bsize, i = 0, bytes = 0, byte_offset = 0;
+	int index = page->index >> (sblk->block_log - PAGE_CACHE_SHIFT);
+ 	void *pageaddr;
+	struct squashfs_fragment_cache *fragment = NULL;
+	char *data_ptr = msblk->read_page;
+
+	int mask = (1 << (sblk->block_log - PAGE_CACHE_SHIFT)) - 1;
+	int start_index = page->index & ~mask;
+	int end_index = start_index | mask;
+
+	TRACE("Entered squashfs_readpage, page index %lx, start block %llx\n",
+					page->index,
+					SQUASHFS_I(inode)->start_block);
+
+	if (page->index >= ((i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
+					PAGE_CACHE_SHIFT))
+		goto skip_read;
+
+	if (SQUASHFS_I(inode)->u.s1.fragment_start_block == SQUASHFS_INVALID_BLK
+					|| index < (i_size_read(inode) >>
+					sblk->block_log)) {
+		if ((block = (msblk->read_blocklist)(inode, index, 1,
+					block_list, NULL, &bsize)) == 0)
+			goto skip_read;
+
+		down(&msblk->read_page_mutex);
+
+		if (!(bytes = squashfs_read_data(inode->i_sb, msblk->read_page,
+					block, bsize, NULL))) {
+			ERROR("Unable to read page, block %llx, size %x\n", block,
+					bsize);
+			up(&msblk->read_page_mutex);
+			goto skip_read;
+		}
+	} else {
+		if ((fragment = get_cached_fragment(inode->i_sb,
+					SQUASHFS_I(inode)->
+					u.s1.fragment_start_block,
+					SQUASHFS_I(inode)->u.s1.fragment_size))
+					== NULL) {
+			ERROR("Unable to read page, block %llx, size %x\n",
+					SQUASHFS_I(inode)->
+					u.s1.fragment_start_block,
+					(int) SQUASHFS_I(inode)->
+					u.s1.fragment_size);
+			goto skip_read;
+		}
+		bytes = SQUASHFS_I(inode)->u.s1.fragment_offset +
+					(i_size_read(inode) & (sblk->block_size
+					- 1));
+		byte_offset = SQUASHFS_I(inode)->u.s1.fragment_offset;
+		data_ptr = fragment->data;
+	}
+
+	for (i = start_index; i <= end_index && byte_offset < bytes;
+					i++, byte_offset += PAGE_CACHE_SIZE) {
+		struct page *push_page;
+		int available_bytes = (bytes - byte_offset) > PAGE_CACHE_SIZE ?
+					PAGE_CACHE_SIZE : bytes - byte_offset;
+
+		TRACE("bytes %d, i %d, byte_offset %d, available_bytes %d\n",
+					bytes, i, byte_offset, available_bytes);
+
+		if (i == page->index)  {
+			pageaddr = kmap_atomic(page, KM_USER0);
+			memcpy(pageaddr, data_ptr + byte_offset,
+					available_bytes);
+			memset(pageaddr + available_bytes, 0,
+					PAGE_CACHE_SIZE - available_bytes);
+			kunmap_atomic(pageaddr, KM_USER0);
+			flush_dcache_page(page);
+			SetPageUptodate(page);
+			unlock_page(page);
+		} else if ((push_page =
+				grab_cache_page_nowait(page->mapping, i))) {
+ 			pageaddr = kmap_atomic(push_page, KM_USER0);
+
+			memcpy(pageaddr, data_ptr + byte_offset,
+					available_bytes);
+			memset(pageaddr + available_bytes, 0,
+					PAGE_CACHE_SIZE - available_bytes);
+			kunmap_atomic(pageaddr, KM_USER0);
+			flush_dcache_page(push_page);
+			SetPageUptodate(push_page);
+			unlock_page(push_page);
+			page_cache_release(push_page);
+		}
+	}
+
+	if (SQUASHFS_I(inode)->u.s1.fragment_start_block == SQUASHFS_INVALID_BLK
+					|| index < (i_size_read(inode) >>
+					sblk->block_log))
+		up(&msblk->read_page_mutex);
+	else
+		release_cached_fragment(msblk, fragment);
+
+	return 0;
+
+skip_read:
+	pageaddr = kmap_atomic(page, KM_USER0);
+	memset(pageaddr + bytes, 0, PAGE_CACHE_SIZE - bytes);
+	kunmap_atomic(pageaddr, KM_USER0);
+	flush_dcache_page(page);
+	SetPageUptodate(page);
+	unlock_page(page);
+
+	return 0;
+}
+
+
+static int squashfs_readpage4K(struct file *file, struct page *page)
+{
+	struct inode *inode = page->mapping->host;
+	struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
+	struct squashfs_super_block *sblk = &msblk->sblk;
+	unsigned char block_list[SIZE];
+	long long block;
+	unsigned int bsize, bytes = 0;
+ 	void *pageaddr;
+
+	TRACE("Entered squashfs_readpage4K, page index %lx, start block %llx\n",
+					page->index,
+					SQUASHFS_I(inode)->start_block);
+
+	if (page->index >= ((i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
+					PAGE_CACHE_SHIFT)) {
+		pageaddr = kmap_atomic(page, KM_USER0);
+		goto skip_read;
+	}
+
+	if (SQUASHFS_I(inode)->u.s1.fragment_start_block == SQUASHFS_INVALID_BLK
+					|| page->index < (i_size_read(inode) >>
+					sblk->block_log)) {
+		block = (msblk->read_blocklist)(inode, page->index, 1,
+					block_list, NULL, &bsize);
+
+		down(&msblk->read_page_mutex);
+		bytes = squashfs_read_data(inode->i_sb, msblk->read_page, block,
+					bsize, NULL);
+		pageaddr = kmap_atomic(page, KM_USER0);
+		if (bytes)
+			memcpy(pageaddr, msblk->read_page, bytes);
+		else
+			ERROR("Unable to read page, block %llx, size %x\n",
+					block, bsize);
+		up(&msblk->read_page_mutex);
+	} else {
+		struct squashfs_fragment_cache *fragment =
+			get_cached_fragment(inode->i_sb,
+					SQUASHFS_I(inode)->
+					u.s1.fragment_start_block,
+					SQUASHFS_I(inode)-> u.s1.fragment_size);
+		pageaddr = kmap_atomic(page, KM_USER0);
+		if (fragment) {
+			bytes = i_size_read(inode) & (sblk->block_size - 1);
+			memcpy(pageaddr, fragment->data + SQUASHFS_I(inode)->
+					u.s1.fragment_offset, bytes);
+			release_cached_fragment(msblk, fragment);
+		} else
+			ERROR("Unable to read page, block %llx, size %x\n",
+					SQUASHFS_I(inode)->
+					u.s1.fragment_start_block, (int)
+					SQUASHFS_I(inode)-> u.s1.fragment_size);
+	}
+
+skip_read:
+	memset(pageaddr + bytes, 0, PAGE_CACHE_SIZE - bytes);
+	kunmap_atomic(pageaddr, KM_USER0);
+	flush_dcache_page(page);
+	SetPageUptodate(page);
+	unlock_page(page);
+
+	return 0;
+}
+
+
+static int get_dir_index_using_offset(struct super_block *s, long long
+				*next_block, unsigned int *next_offset,
+				long long index_start,
+				unsigned int index_offset, int i_count,
+				long long f_pos)
+{
+	struct squashfs_sb_info *msblk = s->s_fs_info;
+	struct squashfs_super_block *sblk = &msblk->sblk;
+	int i, length = 0;
+	struct squashfs_dir_index index;
+
+	TRACE("Entered get_dir_index_using_offset, i_count %d, f_pos %d\n",
+					i_count, (unsigned int) f_pos);
+
+	f_pos =- 3;
+	if (f_pos == 0)
+		goto finish;
+
+	for (i = 0; i < i_count; i++) {
+		if (msblk->swap) {
+			struct squashfs_dir_index sindex;
+			squashfs_get_cached_block(s, (char *) &sindex,
+					index_start, index_offset,
+					sizeof(sindex), &index_start,
+					&index_offset);
+			SQUASHFS_SWAP_DIR_INDEX(&index, &sindex);
+		} else
+			squashfs_get_cached_block(s, (char *) &index,
+					index_start, index_offset,
+					sizeof(index), &index_start,
+					&index_offset);
+
+		if (index.index > f_pos)
+			break;
+
+		squashfs_get_cached_block(s, NULL, index_start, index_offset,
+					index.size + 1, &index_start,
+					&index_offset);
+
+		length = index.index;
+		*next_block = index.start_block + sblk->directory_table_start;
+	}
+
+	*next_offset = (length + *next_offset) % SQUASHFS_METADATA_SIZE;
+
+finish:
+	return length + 3;
+}
+
+
+static int get_dir_index_using_name(struct super_block *s, long long
+				*next_block, unsigned int *next_offset,