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Commit cfd3a03d authored by Jeremy Compostella's avatar Jeremy Compostella
Browse files

libsparse: move_chunks_up_to_len() does not account skip chunks 

I caught the fastboot host command sending more data than the fastboot
device can accept.  Fastboot host command was sending 36 surplus bytes
because of 3 skip chunks that were not taken into account in
move_chunks_up_to_len() algorithm.

Change-Id: I39a4a033c9b15893bd70e553f17116735ee4a48e
parent 27cda9a5

libsparse/sparse.c

+10 −3
Original line number Diff line number Diff line
@@ -238,14 +238,15 @@ static struct backed_block *move_chunks_up_to_len(struct sparse_file *from, 
	struct backed_block *last_bb = NULL;

	struct backed_block *bb;

	struct backed_block *start;

	unsigned int last_block = 0;

	int64_t file_len = 0;

	int ret;



	/*

	 * overhead is sparse file header, initial skip chunk, split chunk, end

	 * skip chunk, and crc chunk.

	 * overhead is sparse file header, the potential end skip

	 * chunk and crc chunk.

	 */

	int overhead = sizeof(sparse_header_t) + 4 * sizeof(chunk_header_t) +

	int overhead = sizeof(sparse_header_t) + 2 * sizeof(chunk_header_t) +

			sizeof(uint32_t);

	len -= overhead;
@@ -258,6 +259,11 @@ static struct backed_block *move_chunks_up_to_len(struct sparse_file *from, 


	for (bb = start; bb; bb = backed_block_iter_next(bb)) {

		count = 0;

		if (backed_block_block(bb) > last_block)

			count += sizeof(chunk_header_t);

		last_block = backed_block_block(bb) +

				DIV_ROUND_UP(backed_block_len(bb), to->block_size);



		/* will call out_counter_write to update count */

		ret = sparse_file_write_block(out_counter, bb);

		if (ret) {
@@ -270,6 +276,7 @@ static struct backed_block *move_chunks_up_to_len(struct sparse_file *from, 
			 * requested size, split the chunk.  Results in sparse files that

			 * are at least 7/8ths of the requested size

			 */

			file_len += sizeof(chunk_header_t);

			if (!last_bb || (len - file_len > (len / 8))) {

				backed_block_split(from->backed_block_list, bb, len - file_len);

				last_bb = bb;