From nobody Sat Sep 21 04:42:12 2024 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1705564536204341.39425485949164; Wed, 17 Jan 2024 23:55:36 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rQNE3-0000L3-AL; Thu, 18 Jan 2024 02:54:11 -0500 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 1rQNE1-0000KX-SF; Thu, 18 Jan 2024 02:54:09 -0500 Received: from isrv.corpit.ru ([86.62.121.231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rQNDz-0007JE-VP; Thu, 18 Jan 2024 02:54:09 -0500 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id D25A74502B; Thu, 18 Jan 2024 10:54:34 +0300 (MSK) Received: from tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with SMTP id 0A85F66194; Thu, 18 Jan 2024 10:54:05 +0300 (MSK) Received: (nullmailer pid 2381631 invoked by uid 1000); Thu, 18 Jan 2024 07:54:04 -0000 From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Kevin Wolf , Michael Tokarev Subject: [Stable-8.2.1 01/38] block: Fix crash when loading snapshot on inactive node Date: Thu, 18 Jan 2024 10:52:28 +0300 Message-Id: <20240118075404.2381519-1-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.2 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=86.62.121.231; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1705564538292100007 Content-Type: text/plain; charset="utf-8" From: Kevin Wolf bdrv_is_read_only() only checks if the node is configured to be read-only eventually, but even if it returns false, writing to the node may not be permitted at the moment (because it's inactive). bdrv_is_writable() checks that the node can be written to right now, and this is what the snapshot operations really need. Change bdrv_can_snapshot() to use bdrv_is_writable() to fix crashes like the following: $ ./qemu-system-x86_64 -hda /tmp/test.qcow2 -loadvm foo -incoming defer qemu-system-x86_64: ../block/io.c:1990: int bdrv_co_write_req_prepare(BdrvC= hild *, int64_t, int64_t, BdrvTrackedRequest *, int): Assertion `!(bs->open= _flags & BDRV_O_INACTIVE)' failed. The resulting error message after this patch isn't perfect yet, but at least it doesn't crash any more: $ ./qemu-system-x86_64 -hda /tmp/test.qcow2 -loadvm foo -incoming defer qemu-system-x86_64: Device 'ide0-hd0' is writable but does not support snap= shots Signed-off-by: Kevin Wolf Message-ID: <20231201142520.32255-2-kwolf@redhat.com> Signed-off-by: Kevin Wolf (cherry picked from commit d3007d348adaaf04ee8b099a475282034a662414) Signed-off-by: Michael Tokarev diff --git a/block/snapshot.c b/block/snapshot.c index ec8cf4810b..c4d40e80dd 100644 --- a/block/snapshot.c +++ b/block/snapshot.c @@ -196,8 +196,10 @@ bdrv_snapshot_fallback(BlockDriverState *bs) int bdrv_can_snapshot(BlockDriverState *bs) { BlockDriver *drv =3D bs->drv; + GLOBAL_STATE_CODE(); - if (!drv || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) { + + if (!drv || !bdrv_is_inserted(bs) || !bdrv_is_writable(bs)) { return 0; } =20 --=20 2.39.2