From patchwork Tue Mar 26 13:54:39 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 1916175 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=DP25vuDJ; dkim-atps=neutral Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=patchwork.ozlabs.org) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4V3rtK6M0jz1yWr for ; Wed, 27 Mar 2024 00:55:52 +1100 (AEDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rp7GW-0004Cv-2q; Tue, 26 Mar 2024 09:55:00 -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 1rp7GU-0004BW-G9 for qemu-devel@nongnu.org; Tue, 26 Mar 2024 09:54:58 -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 1rp7GT-0001Pp-01 for qemu-devel@nongnu.org; Tue, 26 Mar 2024 09:54:58 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1711461296; 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=iiFRDqyPBuCxQcW8SpSU8hf+uTFJyzli3rpm/de5tJE=; b=DP25vuDJiL02j91oFthLeLZbNgpoWq3i/2vtGcbb0fB+FqbgSQxJDOG3xoy7Q6WndfDgRv 7LAlsjxZSHwWUQxMenJ0TCRsWtl4761fY4E47eTVBKVY8lGQJ9WkC1tj572wCd8OrBFFJ4 WVP+mgZSeXUI8iCHQTNRCDGtva3V78A= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-653-KXZaZdYPNEOFMyNGUI__xg-1; Tue, 26 Mar 2024 09:54:52 -0400 X-MC-Unique: KXZaZdYPNEOFMyNGUI__xg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (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 mimecast-mx02.redhat.com (Postfix) with ESMTPS id 6529D8007A2; Tue, 26 Mar 2024 13:54:52 +0000 (UTC) Received: from merkur.fritz.box (unknown [10.39.193.60]) by smtp.corp.redhat.com (Postfix) with ESMTP id B063E1121312; Tue, 26 Mar 2024 13:54:51 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Cc: kwolf@redhat.com, peter.maydell@linaro.org, qemu-devel@nongnu.org Subject: [PULL 5/6] block-backend: fix edge case in bdrv_next_cleanup() where BDS associated to BB changes Date: Tue, 26 Mar 2024 14:54:39 +0100 Message-ID: <20240326135440.421609-6-kwolf@redhat.com> In-Reply-To: <20240326135440.421609-1-kwolf@redhat.com> References: <20240326135440.421609-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.3 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: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.088, 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_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable 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+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Fiona Ebner Same rationale as for commit "block-backend: fix edge case in bdrv_next() where BDS associated to BB changes". The block graph might change between the bdrv_next() call and the bdrv_next_cleanup() call, so it could be that the associated BDS is not the same that was referenced previously anymore. Instead, rely on bdrv_next() to set it->bs to the BDS it referenced and unreference that one in any case. Signed-off-by: Fiona Ebner Message-ID: <20240322095009.346989-4-f.ebner@proxmox.com> Reviewed-by: Kevin Wolf Reviewed-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- block/block-backend.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/block/block-backend.c b/block/block-backend.c index 28af1eb17a..db6f9b92a3 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -663,13 +663,10 @@ void bdrv_next_cleanup(BdrvNextIterator *it) /* Must be called from the main loop */ assert(qemu_get_current_aio_context() == qemu_get_aio_context()); - if (it->phase == BDRV_NEXT_BACKEND_ROOTS) { - if (it->blk) { - bdrv_unref(blk_bs(it->blk)); - blk_unref(it->blk); - } - } else { - bdrv_unref(it->bs); + bdrv_unref(it->bs); + + if (it->phase == BDRV_NEXT_BACKEND_ROOTS && it->blk) { + blk_unref(it->blk); } bdrv_next_reset(it);