From patchwork Thu Nov 1 18:27:35 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vladimir Sementsov-Ogievskiy X-Patchwork-Id: 992050 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=2001:4830:134:3::11; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=virtuozzo.com Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 42mDTP3HbkzB2xQ for ; Fri, 2 Nov 2018 05:37:29 +1100 (AEDT) Received: from localhost ([::1]:43533 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gIHqQ-0003fq-K3 for incoming@patchwork.ozlabs.org; Thu, 01 Nov 2018 14:37:26 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55894) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gIHhA-0002Xg-92 for qemu-devel@nongnu.org; Thu, 01 Nov 2018 14:27:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gIHh9-0007je-3F for qemu-devel@nongnu.org; Thu, 01 Nov 2018 14:27:52 -0400 Received: from relay.sw.ru ([185.231.240.75]:47976) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gIHh8-0007ey-O0; Thu, 01 Nov 2018 14:27:50 -0400 Received: from [10.28.8.145] (helo=kvm.sw.ru) by relay.sw.ru with esmtp (Exim 4.90_1) (envelope-from ) id 1gIHgy-0002Mo-RI; Thu, 01 Nov 2018 21:27:40 +0300 From: Vladimir Sementsov-Ogievskiy To: qemu-devel@nongnu.org, qemu-block@nongnu.org Date: Thu, 1 Nov 2018 21:27:35 +0300 Message-Id: <20181101182738.70462-5-vsementsov@virtuozzo.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20181101182738.70462-1-vsementsov@virtuozzo.com> References: <20181101182738.70462-1-vsementsov@virtuozzo.com> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 185.231.240.75 Subject: [Qemu-devel] [PATCH 4/7] qcow2: refactor decompress_buffer X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, den@openvz.org, vsementsov@virtuozzo.com, mreitz@redhat.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" - 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 --- block/qcow2.c | 56 ++++++++++++++++++++++++++++++++------------------- 1 file changed, 35 insertions(+), 21 deletions(-) diff --git a/block/qcow2.c b/block/qcow2.c index b45a6c4135..e9d24b801e 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -3758,32 +3758,46 @@ 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 @@ -3973,8 +3987,8 @@ 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;