diff options
| -rw-r--r-- | block/qcow2.c | 56 |
1 files changed, 35 insertions, 21 deletions
diff --git a/block/qcow2.c b/block/qcow2.c index a3b9fe391c..b60c01582c 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -3762,32 +3762,46 @@ static ssize_t qcow2_compress(void *dest, size_t dest_size, return ret; } -static int decompress_buffer(uint8_t *out_buf, int out_buf_size, - const uint8_t *buf, int buf_size) +/* + * qcow2_decompress() + * + * Decompress some data (not more than @src_size bytes) to produce exactly + * @dest_size bytes. + * + * @dest - destination buffer, @dest_size bytes + * @src - source buffer, @src_size bytes + * + * Returns: 0 on success + * -1 on fail + */ +static ssize_t qcow2_decompress(void *dest, size_t dest_size, + const void *src, size_t src_size) { - z_stream strm1, *strm = &strm1; - int ret, out_len; - - memset(strm, 0, sizeof(*strm)); + int ret = 0; + z_stream strm; - strm->next_in = (uint8_t *)buf; - strm->avail_in = buf_size; - strm->next_out = out_buf; - strm->avail_out = out_buf_size; + memset(&strm, 0, sizeof(strm)); + strm.avail_in = src_size; + strm.next_in = (void *) src; + strm.avail_out = dest_size; + strm.next_out = dest; - ret = inflateInit2(strm, -12); + ret = inflateInit2(&strm, -12); if (ret != Z_OK) { return -1; } - ret = inflate(strm, Z_FINISH); - out_len = strm->next_out - out_buf; - if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) || - out_len != out_buf_size) { - inflateEnd(strm); - return -1; + + ret = inflate(&strm, Z_FINISH); + if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) || strm.avail_out != 0) { + /* We approve Z_BUF_ERROR because we need @dest buffer to be filled, but + * @src buffer may be processed partly (because in qcow2 we know size of + * compressed data with precision of one sector) */ + ret = -1; } - inflateEnd(strm); - return 0; + + inflateEnd(&strm); + + return ret; } #define MAX_COMPRESS_THREADS 4 @@ -3977,8 +3991,8 @@ int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset) if (ret < 0) { return ret; } - if (decompress_buffer(s->cluster_cache, s->cluster_size, - s->cluster_data + sector_offset, csize) < 0) { + if (qcow2_decompress(s->cluster_cache, s->cluster_size, + s->cluster_data + sector_offset, csize) < 0) { return -EIO; } s->cluster_cache_offset = coffset; |