112 static void read_ahead(struct buffered_reader *reader, sector_t block_number)  in read_ahead()  argument
114 	if (block_number < reader->limit) {  in read_ahead()
116 					  reader->limit - block_number);  in read_ahead()
118 		dm_bufio_prefetch(reader->client, block_number, read_ahead);  in read_ahead()
122 void uds_free_buffered_reader(struct buffered_reader *reader)  in uds_free_buffered_reader()  argument
124 	if (reader == NULL)  in uds_free_buffered_reader()
127 	if (reader->buffer != NULL)  in uds_free_buffered_reader()
128 		dm_bufio_release(reader->buffer);  in uds_free_buffered_reader()
130 	dm_bufio_client_destroy(reader->client);  in uds_free_buffered_reader()
131 	uds_put_io_factory(reader->factory);  in uds_free_buffered_reader()
132 	vdo_free(reader);  in uds_free_buffered_reader()
141 	struct buffered_reader *reader = NULL;  in uds_make_buffered_reader()  local
147 	result = vdo_allocate(1, struct buffered_reader, "buffered reader", &reader);  in uds_make_buffered_reader()
153 	*reader = (struct buffered_reader) {  in uds_make_buffered_reader()
163 	read_ahead(reader, 0);  in uds_make_buffered_reader()
165 	*reader_ptr = reader;  in uds_make_buffered_reader()
169 static int position_reader(struct buffered_reader *reader, sector_t block_number,  in position_reader()  argument
175 	if ((reader->end == NULL) || (block_number != reader->block_number)) {  in position_reader()
176 		if (block_number >= reader->limit)  in position_reader()
179 		if (reader->buffer != NULL)  in position_reader()
180 			dm_bufio_release(vdo_forget(reader->buffer));  in position_reader()
182 		data = dm_bufio_read(reader->client, block_number, &buffer);  in position_reader()
186 		reader->buffer = buffer;  in position_reader()
187 		reader->start = data;  in position_reader()
188 		if (block_number == reader->block_number + 1)  in position_reader()
189 			read_ahead(reader, block_number + 1);  in position_reader()
192 	reader->block_number = block_number;  in position_reader()
193 	reader->end = reader->start + offset;  in position_reader()
197 static size_t bytes_remaining_in_read_buffer(struct buffered_reader *reader)  in bytes_remaining_in_read_buffer()  argument
199 	return (reader->end == NULL) ? 0 : reader->start + UDS_BLOCK_SIZE - reader->end;  in bytes_remaining_in_read_buffer()
202 static int reset_reader(struct buffered_reader *reader)  in reset_reader()  argument
206 	if (bytes_remaining_in_read_buffer(reader) > 0)  in reset_reader()
209 	block_number = reader->block_number;  in reset_reader()
210 	if (reader->end != NULL)  in reset_reader()
213 	return position_reader(reader, block_number, 0);  in reset_reader()
216 int uds_read_from_buffered_reader(struct buffered_reader *reader, u8 *data,  in uds_read_from_buffered_reader()  argument
223 		result = reset_reader(reader);  in uds_read_from_buffered_reader()
227 		chunk_size = min(length, bytes_remaining_in_read_buffer(reader));  in uds_read_from_buffered_reader()
228 		memcpy(data, reader->end, chunk_size);  in uds_read_from_buffered_reader()
231 		reader->end += chunk_size;  in uds_read_from_buffered_reader()
241 int uds_verify_buffered_data(struct buffered_reader *reader, const u8 *value,  in uds_verify_buffered_data()  argument
246 	sector_t start_block_number = reader->block_number;  in uds_verify_buffered_data()
247 	int start_offset = reader->end - reader->start;  in uds_verify_buffered_data()
250 		result = reset_reader(reader);  in uds_verify_buffered_data()
256 		chunk_size = min(length, bytes_remaining_in_read_buffer(reader));  in uds_verify_buffered_data()
257 		if (memcmp(value, reader->end, chunk_size) != 0) {  in uds_verify_buffered_data()
264 		reader->end += chunk_size;  in uds_verify_buffered_data()
268 		position_reader(reader, start_block_number, start_offset);  in uds_verify_buffered_data()