From patchwork Mon Dec 19 08:51:23 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dou Liyang X-Patchwork-Id: 9479881 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 57904606DB for ; Mon, 19 Dec 2016 08:55:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4AC3D28419 for ; Mon, 19 Dec 2016 08:55:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3EEAE28483; Mon, 19 Dec 2016 08:55:38 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 188FF28419 for ; Mon, 19 Dec 2016 08:55:37 +0000 (UTC) Received: from localhost ([::1]:44075 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cItjM-00064O-71 for patchwork-qemu-devel@patchwork.kernel.org; Mon, 19 Dec 2016 03:55:36 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58405) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cItgD-0004B6-82 for qemu-devel@nongnu.org; Mon, 19 Dec 2016 03:52:22 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cItgA-00080L-Br for qemu-devel@nongnu.org; Mon, 19 Dec 2016 03:52:21 -0500 Received: from [59.151.112.132] (port=17864 helo=heian.cn.fujitsu.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cItg9-0007mf-FQ for qemu-devel@nongnu.org; Mon, 19 Dec 2016 03:52:18 -0500 X-IronPort-AV: E=Sophos;i="5.22,518,1449504000"; d="scan'208";a="14050857" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 19 Dec 2016 16:51:57 +0800 Received: from G08CNEXCHPEKD02.g08.fujitsu.local (unknown [10.167.33.83]) by cn.fujitsu.com (Postfix) with ESMTP id 7FE74467049D; Mon, 19 Dec 2016 16:51:54 +0800 (CST) Received: from localhost.localdomain.localdomain (10.167.226.106) by G08CNEXCHPEKD02.g08.fujitsu.local (10.167.33.89) with Microsoft SMTP Server (TLS) id 14.3.319.2; Mon, 19 Dec 2016 16:51:59 +0800 From: Dou Liyang To: , , , , , , Date: Mon, 19 Dec 2016 16:51:23 +0800 Message-ID: <1482137486-9843-2-git-send-email-douly.fnst@cn.fujitsu.com> X-Mailer: git-send-email 2.5.5 In-Reply-To: <1482137486-9843-1-git-send-email-douly.fnst@cn.fujitsu.com> References: <1482137486-9843-1-git-send-email-douly.fnst@cn.fujitsu.com> MIME-Version: 1.0 X-Originating-IP: [10.167.226.106] X-yoursite-MailScanner-ID: 7FE74467049D.A036C X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: douly.fnst@cn.fujitsu.com X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 59.151.112.132 Subject: [Qemu-devel] [PATCH RFC v2 1/4] block: refactor bdrv_next_node for readability 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: izumi.taku@jp.fujitsu.com, caoj.fnst@cn.fujitsu.com, fanc.fnst@cn.fujitsu.com, qemu-devel@nongnu.org, douly.fnst@cn.fujitsu.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP make the bdrv_next_node() clearly and add some comments. Signed-off-by: Dou Liyang --- block.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/block.c b/block.c index 39ddea3..01c9e51 100644 --- a/block.c +++ b/block.c @@ -2931,12 +2931,20 @@ bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base) return top != NULL; } +/* + * Return the BlockDriverStates of all the named nodes. + * If @bs is null, return the first one. + * Else, return @bs's next sibling, which may be null. + * + * To iterate over all BlockDriverStates, do + * for (bs = bdrv_next_node(NULL); bs; bs = bdrv_next_node(blk)) { + * ... + * } + */ BlockDriverState *bdrv_next_node(BlockDriverState *bs) { - if (!bs) { - return QTAILQ_FIRST(&graph_bdrv_states); - } - return QTAILQ_NEXT(bs, node_list); + return bs ? QTAILQ_NEXT(bs, node_list) + : QTAILQ_FIRST(&graph_bdrv_states); } const char *bdrv_get_node_name(const BlockDriverState *bs)