From patchwork Thu Feb 27 18:18:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 11409393 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2D2EA13A4 for ; Thu, 27 Feb 2020 18:19:35 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 03B8E2469B for ; Thu, 27 Feb 2020 18:19:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="IkaA1GbH" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 03B8E2469B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:36202 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j7Nl0-00054R-7C for patchwork-qemu-devel@patchwork.kernel.org; Thu, 27 Feb 2020 13:19:34 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:33659) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j7Njs-0003TW-Qq for qemu-devel@nongnu.org; Thu, 27 Feb 2020 13:18:25 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1j7Njr-0003zO-Jj for qemu-devel@nongnu.org; Thu, 27 Feb 2020 13:18:24 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:22582 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1j7Njr-0003yv-FR for qemu-devel@nongnu.org; Thu, 27 Feb 2020 13:18:23 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582827502; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=uTcNxecxKCRfJbeio/yWCoTSVQA5fom7KF5ZLfprYoE=; b=IkaA1GbHvMZRXUWLDJcZPZNOWqTuj/7t9N872GpXUoaVBOD+K6Gi7cQs+eknUEn0bkML7i moY08RFBJ2MhMw3Gy5AHKz69jz9onC1YkF8DUUCK1jTiaOKeLBGm4peXmw6JBeIIlWpx09 Ll20uxHscXgv6U+lT4J5Rm9F8IU2QVQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-213-tfl_sEhjPjCnnDAxWLpZHg-1; Thu, 27 Feb 2020 13:18:21 -0500 X-MC-Unique: tfl_sEhjPjCnnDAxWLpZHg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0D5DC800D55; Thu, 27 Feb 2020 18:18:20 +0000 (UTC) Received: from linux.fritz.box.com (unknown [10.36.118.7]) by smtp.corp.redhat.com (Postfix) with ESMTP id B1C2A8C081; Thu, 27 Feb 2020 18:18:18 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Subject: [PATCH 2/2] block: bdrv_reopen() with backing file in different AioContext Date: Thu, 27 Feb 2020 19:18:04 +0100 Message-Id: <20200227181804.15299-3-kwolf@redhat.com> In-Reply-To: <20200227181804.15299-1-kwolf@redhat.com> References: <20200227181804.15299-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.120 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, pkrempa@redhat.com, berto@igalia.com, qemu-devel@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" This patch allows bdrv_reopen() (and therefore the x-blockdev-reopen QMP command) to attach a node as the new backing file even if the node is in a different AioContext than the parent if one of both nodes can be moved to the AioContext of the other node. Signed-off-by: Kevin Wolf --- block.c | 36 +++++++++++++++++++++++++++--------- tests/qemu-iotests/245 | 8 +++----- 2 files changed, 30 insertions(+), 14 deletions(-) diff --git a/block.c b/block.c index 202c67e1e8..5dbba6cf31 100644 --- a/block.c +++ b/block.c @@ -3781,6 +3781,29 @@ static void bdrv_reopen_perm(BlockReopenQueue *q, BlockDriverState *bs, *shared = cumulative_shared_perms; } +static bool bdrv_reopen_can_attach(BdrvChild *child, + BlockDriverState *new_child, + BlockDriverState *parent, + Error **errp) +{ + AioContext *parent_ctx = bdrv_get_aio_context(parent); + AioContext *child_ctx = bdrv_get_aio_context(new_child); + GSList *ignore; + bool ret; + + ignore = g_slist_prepend(NULL, child); + ret = bdrv_can_set_aio_context(new_child, parent_ctx, &ignore, NULL); + g_slist_free(ignore); + if (ret) { + return ret; + } + + ignore = g_slist_prepend(NULL, child); + ret = bdrv_can_set_aio_context(parent, child_ctx, &ignore, errp); + g_slist_free(ignore); + return ret; +} + /* * Take a BDRVReopenState and check if the value of 'backing' in the * reopen_state->options QDict is valid or not. @@ -3832,16 +3855,11 @@ static int bdrv_reopen_parse_backing(BDRVReopenState *reopen_state, } /* - * TODO: before removing the x- prefix from x-blockdev-reopen we - * should move the new backing file into the right AioContext - * instead of returning an error. + * Check AioContext compatibility so that the bdrv_set_backing_hd() call in + * bdrv_reopen_commit() won't fail. */ - if (new_backing_bs) { - if (bdrv_get_aio_context(new_backing_bs) != bdrv_get_aio_context(bs)) { - error_setg(errp, "Cannot use a new backing file " - "with a different AioContext"); - return -EINVAL; - } + if (!bdrv_reopen_can_attach(bs->backing, bs, new_backing_bs, errp)) { + return -EINVAL; } /* diff --git a/tests/qemu-iotests/245 b/tests/qemu-iotests/245 index 5a2cd5ed0e..d6135ec14d 100755 --- a/tests/qemu-iotests/245 +++ b/tests/qemu-iotests/245 @@ -1010,18 +1010,16 @@ class TestBlockdevReopen(iotests.QMPTestCase): # neither of them can switch to the other AioContext def test_iothreads_error(self): self.run_test_iothreads('iothread0', 'iothread1', - "Cannot use a new backing file with a different AioContext") + "Cannot change iothread of active block backend") def test_iothreads_compatible_users(self): self.run_test_iothreads('iothread0', 'iothread0') def test_iothreads_switch_backing(self): - self.run_test_iothreads('iothread0', None, - "Cannot use a new backing file with a different AioContext") + self.run_test_iothreads('iothread0', None) def test_iothreads_switch_overlay(self): - self.run_test_iothreads(None, 'iothread0', - "Cannot use a new backing file with a different AioContext") + self.run_test_iothreads(None, 'iothread0') if __name__ == '__main__': iotests.main(supported_fmts=["qcow2"],