From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 73C15C83F22 for ; Tue, 15 Jul 2025 19:33:08 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ublNr-0004dx-VE; Tue, 15 Jul 2025 15:32:29 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ubkwz-00046p-JC for qemu-devel@nongnu.org; Tue, 15 Jul 2025 15:04:36 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ubkww-0001MF-3Q for qemu-devel@nongnu.org; Tue, 15 Jul 2025 15:04:24 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1752606261; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=8W8fQy5JCYizGetg+mDWw1LL18wUNUGbfORKfvklxKo=; b=F7qqcCuY39s+YBFjfDPLhSwt31VNfkoI2ktm7XB6IKaoF06+Xw45cgS4whV8+V16tvOxxB f6xr5rxLHE3j+3PGZg/QzIvl2nIyZMslf2xUesvdzO4ooAPCqc5TwERB4dtjwRN+kuruqR QkESwXt4gD+M0CpUdHrsqkSv1tIFYuY= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-625-9-WJwmQLNkKz1TAbOgkjAQ-1; Tue, 15 Jul 2025 15:04:18 -0400 X-MC-Unique: 9-WJwmQLNkKz1TAbOgkjAQ-1 X-Mimecast-MFC-AGG-ID: 9-WJwmQLNkKz1TAbOgkjAQ_1752606257 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id C3D76195608E; Tue, 15 Jul 2025 19:04:17 +0000 (UTC) Received: from merkur.redhat.com (unknown [10.44.34.84]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 3A667197702B; Tue, 15 Jul 2025 19:04:15 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Cc: kwolf@redhat.com, stefanha@redhat.com, qemu-devel@nongnu.org Subject: [PULL 19/57] block: Allow bdrv_new() with and without graph lock Date: Tue, 15 Jul 2025 21:02:52 +0200 Message-ID: <20250715190330.378764-20-kwolf@redhat.com> In-Reply-To: <20250715190330.378764-1-kwolf@redhat.com> References: <20250715190330.378764-1-kwolf@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Received-SPF: pass client-ip=170.10.129.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org bdrv_new() calls bdrv_drained_begin(), which can poll and therefore can't be called while holding the graph lock. One option to make sure that this call is allowed would be marking bdrv_new() GRAPH_UNLOCKED. However, this is actually an unnecessary restriction because we know that we only just created the BlockDriverState and it isn't even part of the graph yet. We can use bdrv_do_drained_begin_quiesce() instead to avoid the polling, which means that bdrv_new() can now safely be called from callers that hold the graph lock as well as from callers that don't. Signed-off-by: Kevin Wolf --- block.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block.c b/block.c index 932e599f45..fe5aa2e767 100644 --- a/block.c +++ b/block.c @@ -431,7 +431,7 @@ BlockDriverState *bdrv_new(void) bs->block_status_cache = g_new0(BdrvBlockStatusCache, 1); for (i = 0; i < bdrv_drain_all_count; i++) { - bdrv_drained_begin(bs); + bdrv_do_drained_begin_quiesce(bs, NULL); } QTAILQ_INSERT_TAIL(&all_bdrv_states, bs, bs_list); -- 2.50.1