From patchwork Tue Apr 11 12:26:31 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fam Zheng X-Patchwork-Id: 749467 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3w2RLr4g21z9sDG for ; Tue, 11 Apr 2017 22:34:12 +1000 (AEST) Received: from localhost ([::1]:39057 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cxuzq-0001Uw-1z for incoming@patchwork.ozlabs.org; Tue, 11 Apr 2017 08:34:10 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39247) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cxut4-0004LL-Bw for qemu-devel@nongnu.org; Tue, 11 Apr 2017 08:27:11 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cxut1-00043d-MR for qemu-devel@nongnu.org; Tue, 11 Apr 2017 08:27:10 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44892) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cxut1-00042J-GY for qemu-devel@nongnu.org; Tue, 11 Apr 2017 08:27:07 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 887372BA6E1; Tue, 11 Apr 2017 12:27:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 887372BA6E1 Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=famz@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 887372BA6E1 Received: from lemon.redhat.com (ovpn-8-27.pek2.redhat.com [10.72.8.27]) by smtp.corp.redhat.com (Postfix) with ESMTP id BA0FB7C12E; Tue, 11 Apr 2017 12:27:04 +0000 (UTC) From: Fam Zheng To: qemu-devel@nongnu.org Date: Tue, 11 Apr 2017 20:26:31 +0800 Message-Id: <20170411122632.14050-11-famz@redhat.com> In-Reply-To: <20170411122632.14050-1-famz@redhat.com> References: <20170411122632.14050-1-famz@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Tue, 11 Apr 2017 12:27:06 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 10/11] block: Fix bdrv_co_flush early return 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: Peter Maydell , famz@redhat.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" bdrv_inc_in_flight and bdrv_dec_in_flight are mandatory for BDRV_POLL_WHILE to work, even for the shortcut case where flush is unnecessary. Move the if block to below bdrv_dec_in_flight, and BTW fix the variable declaration position. Signed-off-by: Fam Zheng Acked-by: Stefan Hajnoczi Reviewed-by: Kevin Wolf Reviewed-by: Paolo Bonzini --- block/io.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/block/io.c b/block/io.c index 00e45ca..bae6947 100644 --- a/block/io.c +++ b/block/io.c @@ -2278,16 +2278,17 @@ static void coroutine_fn bdrv_flush_co_entry(void *opaque) int coroutine_fn bdrv_co_flush(BlockDriverState *bs) { - int ret; - - if (!bs || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs) || - bdrv_is_sg(bs)) { - return 0; - } + int current_gen; + int ret = 0; bdrv_inc_in_flight(bs); - int current_gen = bs->write_gen; + if (!bs || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs) || + bdrv_is_sg(bs)) { + goto early_exit; + } + + current_gen = bs->write_gen; /* Wait until any previous flushes are completed */ while (bs->active_flush_req) { @@ -2370,6 +2371,7 @@ out: /* Return value is ignored - it's ok if wait queue is empty */ qemu_co_queue_next(&bs->flush_queue); +early_exit: bdrv_dec_in_flight(bs); return ret; }