From patchwork Wed Jul 20 13:56:27 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Frediano Ziglio X-Patchwork-Id: 105771 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [140.186.70.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id DF60AB6F6F for ; Thu, 21 Jul 2011 03:52:31 +1000 (EST) Received: from localhost ([::1]:50468 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QjaGt-0000h3-Hb for incoming@patchwork.ozlabs.org; Wed, 20 Jul 2011 13:09:19 -0400 Received: from eggs.gnu.org ([140.186.70.92]:58712) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QjY9R-0004R3-Ki for qemu-devel@nongnu.org; Wed, 20 Jul 2011 10:53:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QjY9P-0007eP-BH for qemu-devel@nongnu.org; Wed, 20 Jul 2011 10:53:28 -0400 Received: from mail-iy0-f173.google.com ([209.85.210.173]:59564) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QjXIl-00040H-VI for qemu-devel@nongnu.org; Wed, 20 Jul 2011 09:59:04 -0400 Received: by mail-iy0-f173.google.com with SMTP id 39so229029iyb.4 for ; Wed, 20 Jul 2011 06:59:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; bh=c6EIImUPq963SjQKeaMy4MjmHmGdf0WbT+OKVU68igQ=; b=duT0Tv09NbujjGO9wn+/an5MvXN84l3wS9+MOKVFwFDQC4CSv7mweMHS1V4IP/wA+8 U+PmzUXbgcuyGJd9LZd3yJ0046wWeNOBRb3Tcea0ITnX988ibL/2Z6GdT7JTMG+fdmWu wdIqLQdLLpkK9uaa7BfTRrxfn0d3GA5IYMJx4= Received: by 10.231.92.84 with SMTP id q20mr8339845ibm.92.1311170343491; Wed, 20 Jul 2011 06:59:03 -0700 (PDT) Received: from localhost.localdomain (tor-exit-router41-readme.formlessnetworking.net [199.48.147.41]) by mx.google.com with ESMTPS id s2sm359274icw.17.2011.07.20.06.58.50 (version=TLSv1/SSLv3 cipher=OTHER); Wed, 20 Jul 2011 06:59:03 -0700 (PDT) From: Frediano Ziglio To: qemu-devel@nongnu.org Date: Wed, 20 Jul 2011 15:56:27 +0200 Message-Id: <1311170189-29734-4-git-send-email-freddy77@gmail.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1311170189-29734-1-git-send-email-freddy77@gmail.com> References: <1311170189-29734-1-git-send-email-freddy77@gmail.com> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 2) X-Received-From: 209.85.210.173 Cc: Kevin Wolf , Frediano Ziglio Subject: [Qemu-devel] [RFC PATCH 3/5] qcow: move some blocks of code to avoid useless variable initialization X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Signed-off-by: Frediano Ziglio --- block/qcow.c | 53 ++++++++++++++++++++++++++--------------------------- 1 files changed, 26 insertions(+), 27 deletions(-) diff --git a/block/qcow.c b/block/qcow.c index cd1f9e3..8ccd7d7 100644 --- a/block/qcow.c +++ b/block/qcow.c @@ -520,35 +520,18 @@ static int qcow_aio_read_cb(QCowAIOCB *acb) BlockDriverState *bs = acb->bs; BDRVQcowState *s = bs->opaque; int index_in_cluster; - int ret, n = 0; - uint64_t cluster_offset = 0; + int ret, n; + uint64_t cluster_offset; struct iovec hd_iov; QEMUIOVector hd_qiov; redo: - /* post process the read buffer */ - if (!cluster_offset) { - /* nothing to do */ - } else if (cluster_offset & QCOW_OFLAG_COMPRESSED) { - /* nothing to do */ - } else { - if (s->crypt_method) { - encrypt_sectors(s, acb->sector_num, acb->buf, acb->buf, - n, 0, - &s->aes_decrypt_key); - } - } - - acb->nb_sectors -= n; - acb->sector_num += n; - acb->buf += n * 512; - if (acb->nb_sectors == 0) { /* request completed */ return 0; } - /* prepare next AIO request */ + /* prepare next request */ cluster_offset = get_cluster_offset(bs, acb->sector_num << 9, 0, 0, 0, 0); index_in_cluster = acb->sector_num & (s->cluster_sectors - 1); @@ -572,7 +555,6 @@ static int qcow_aio_read_cb(QCowAIOCB *acb) } else { /* Note: in this case, no need to wait */ memset(acb->buf, 0, 512 * n); - goto redo; } } else if (cluster_offset & QCOW_OFLAG_COMPRESSED) { /* add AIO support for compressed blocks ? */ @@ -581,7 +563,6 @@ static int qcow_aio_read_cb(QCowAIOCB *acb) } memcpy(acb->buf, s->cluster_cache + index_in_cluster * 512, 512 * n); - goto redo; } else { if ((cluster_offset & 511) != 0) { return -EIO; @@ -599,6 +580,23 @@ static int qcow_aio_read_cb(QCowAIOCB *acb) } } + /* post process the read buffer */ + if (!cluster_offset) { + /* nothing to do */ + } else if (cluster_offset & QCOW_OFLAG_COMPRESSED) { + /* nothing to do */ + } else { + if (s->crypt_method) { + encrypt_sectors(s, acb->sector_num, acb->buf, acb->buf, + n, 0, + &s->aes_decrypt_key); + } + } + + acb->nb_sectors -= n; + acb->sector_num += n; + acb->buf += n * 512; + goto redo; } @@ -630,16 +628,12 @@ static int qcow_aio_write_cb(QCowAIOCB *acb) int index_in_cluster; uint64_t cluster_offset; const uint8_t *src_buf; - int ret, n = 0; + int ret, n; uint8_t *cluster_data = NULL; struct iovec hd_iov; QEMUIOVector hd_qiov; redo: - acb->nb_sectors -= n; - acb->sector_num += n; - acb->buf += n * 512; - if (acb->nb_sectors == 0) { /* request completed */ return 0; @@ -681,6 +675,11 @@ static int qcow_aio_write_cb(QCowAIOCB *acb) if (ret < 0) { return ret; } + + acb->nb_sectors -= n; + acb->sector_num += n; + acb->buf += n * 512; + goto redo; }