From patchwork Mon Jun 3 15:02:06 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 10973021 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 24F541398 for ; Mon, 3 Jun 2019 15:08:03 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 13640283AD for ; Mon, 3 Jun 2019 15:08:03 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 07AA7287BA; Mon, 3 Jun 2019 15:08:03 +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=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id ACA68286C6 for ; Mon, 3 Jun 2019 15:08:02 +0000 (UTC) Received: from localhost ([127.0.0.1]:36340 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hXoZ7-00042v-Dh for patchwork-qemu-devel@patchwork.kernel.org; Mon, 03 Jun 2019 11:08:01 -0400 Received: from eggs.gnu.org ([209.51.188.92]:39496) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hXoUV-0000KM-4N for qemu-devel@nongnu.org; Mon, 03 Jun 2019 11:03:16 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hXoUT-0006nU-Sc for qemu-devel@nongnu.org; Mon, 03 Jun 2019 11:03:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:12504) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hXoUQ-0006UP-Eq; Mon, 03 Jun 2019 11:03:10 -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 ABD063107B20; Mon, 3 Jun 2019 15:02:54 +0000 (UTC) Received: from linux.fritz.box.com (ovpn-116-129.ams2.redhat.com [10.36.116.129]) by smtp.corp.redhat.com (Postfix) with ESMTP id 85CC961B6A; Mon, 3 Jun 2019 15:02:52 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Date: Mon, 3 Jun 2019 17:02:06 +0200 Message-Id: <20190603150233.6614-2-kwolf@redhat.com> In-Reply-To: <20190603150233.6614-1-kwolf@redhat.com> References: <20190603150233.6614-1-kwolf@redhat.com> MIME-Version: 1.0 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 [10.5.110.47]); Mon, 03 Jun 2019 15:02:59 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 01/28] block: Drain source node in bdrv_replace_node() 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, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP Instead of just asserting that no requests are in flight in bdrv_replace_node(), which is a requirement that most callers ignore, we can just drain the source node right there. This fixes at least starting a commit job while I/O is active on the backing chain, but probably other callers, too. Having requests in flight on the target node isn't a problem because the target just gets new parents, but the call path of running requests isn't modified. So we can just drop this assertion without a replacement. Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1711643 Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz --- block.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/block.c b/block.c index 1a73e310c1..4c3902508d 100644 --- a/block.c +++ b/block.c @@ -4017,13 +4017,13 @@ void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to, uint64_t perm = 0, shared = BLK_PERM_ALL; int ret; - assert(!atomic_read(&from->in_flight)); - assert(!atomic_read(&to->in_flight)); - /* Make sure that @from doesn't go away until we have successfully attached * all of its parents to @to. */ bdrv_ref(from); + assert(qemu_get_current_aio_context() == qemu_get_aio_context()); + bdrv_drained_begin(from); + /* Put all parents into @list and calculate their cumulative permissions */ QLIST_FOREACH_SAFE(c, &from->parents, next_parent, next) { assert(c->bs == from); @@ -4064,6 +4064,7 @@ void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to, out: g_slist_free(list); + bdrv_drained_end(from); bdrv_unref(from); }