From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46146) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gX4Yc-0002Sh-PP for qemu-devel@nongnu.org; Wed, 12 Dec 2018 08:28:11 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gX4Yb-00015t-K7 for qemu-devel@nongnu.org; Wed, 12 Dec 2018 08:28:10 -0500 From: Kevin Wolf Date: Wed, 12 Dec 2018 14:27:04 +0100 Message-Id: <20181212132735.16080-11-kwolf@redhat.com> In-Reply-To: <20181212132735.16080-1-kwolf@redhat.com> References: <20181212132735.16080-1-kwolf@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PULL 10/41] qcow2: refactor decompress_buffer List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: kwolf@redhat.com, peter.maydell@linaro.org, qemu-devel@nongnu.org From: Vladimir Sementsov-Ogievskiy - make it look more like a pair of qcow2_compress - rename the function and its parameters - drop extra out_len variable, check filling of output buffer by strm structure itself - fix code style - add some documentation Signed-off-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Alberto Garcia Signed-off-by: Kevin Wolf --- block/qcow2.c | 56 ++++++++++++++++++++++++++++++++------------------- 1 file changed, 35 insertions(+), 21 deletions(-) diff --git a/block/qcow2.c b/block/qcow2.c index d4d141c495..ac9bb3a225 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; } =20 -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 exact= ly + * @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 =3D &strm1; - int ret, out_len; - - memset(strm, 0, sizeof(*strm)); + int ret =3D 0; + z_stream strm; =20 - strm->next_in =3D (uint8_t *)buf; - strm->avail_in =3D buf_size; - strm->next_out =3D out_buf; - strm->avail_out =3D out_buf_size; + memset(&strm, 0, sizeof(strm)); + strm.avail_in =3D src_size; + strm.next_in =3D (void *) src; + strm.avail_out =3D dest_size; + strm.next_out =3D dest; =20 - ret =3D inflateInit2(strm, -12); + ret =3D inflateInit2(&strm, -12); if (ret !=3D Z_OK) { return -1; } - ret =3D inflate(strm, Z_FINISH); - out_len =3D strm->next_out - out_buf; - if ((ret !=3D Z_STREAM_END && ret !=3D Z_BUF_ERROR) || - out_len !=3D out_buf_size) { - inflateEnd(strm); - return -1; + + ret =3D inflate(&strm, Z_FINISH); + if ((ret !=3D Z_STREAM_END && ret !=3D Z_BUF_ERROR) || strm.avail_ou= t !=3D 0) { + /* We approve Z_BUF_ERROR because we need @dest buffer to be fil= led, but + * @src buffer may be processed partly (because in qcow2 we know= size of + * compressed data with precision of one sector) */ + ret =3D -1; } - inflateEnd(strm); - return 0; + + inflateEnd(&strm); + + return ret; } =20 #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 =3D coffset; --=20 2.19.2