From patchwork Thu Jul 4 21:00:41 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Michael Tokarev X-Patchwork-Id: 13724274 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 B5062C41513 for ; Thu, 4 Jul 2024 21:03:03 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sPTaP-0008Cq-C1; Thu, 04 Jul 2024 17:01:49 -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 1sPTaM-00086l-1P; Thu, 04 Jul 2024 17:01:46 -0400 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 1sPTaF-0004Lz-Lq; Thu, 04 Jul 2024 17:01:45 -0400 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 0ADFD77568; Fri, 5 Jul 2024 00:00:51 +0300 (MSK) Received: from tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with SMTP id 1F00DFECA2; Fri, 5 Jul 2024 00:00:56 +0300 (MSK) Received: (nullmailer pid 1507746 invoked by uid 1000); Thu, 04 Jul 2024 21:00:55 -0000 From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Fabiano Rosas , =?utf-8?q?Danie?= =?utf-8?q?l_P_=2E_Berrang=C3=A9?= , Prasad Pandit , Peter Xu , Michael Tokarev Subject: [Stable-9.0.2 11/22] migration: Fix file migration with fdset Date: Fri, 5 Jul 2024 00:00:41 +0300 Message-Id: <20240704210055.1507652-11-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.2 In-Reply-To: References: MIME-Version: 1.0 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 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 From: Fabiano Rosas When the "file:" migration support was added we missed the special case in the qemu_open_old implementation that allows for a particular file name format to be used to refer to a set of file descriptors that have been previously provided to QEMU via the add-fd QMP command. When using this fdset feature, we should not truncate the migration file because being given an fd means that the management layer is in control of the file and will likely already have some data written to it. This is further indicated by the presence of the 'offset' argument, which indicates the start of the region where QEMU is allowed to write. Fix the issue by replacing the O_TRUNC flag on open by an ftruncate call, which will take the offset into consideration. Fixes: 385f510df5 ("migration: file URI offset") Suggested-by: Daniel P. Berrangé Reviewed-by: Prasad Pandit Reviewed-by: Peter Xu Reviewed-by: Daniel P. Berrangé Signed-off-by: Fabiano Rosas (cherry picked from commit 6d3279655ac49b806265f08415165f471d33e032) Signed-off-by: Michael Tokarev diff --git a/migration/file.c b/migration/file.c index ab18ba505a..ba5b5c44ff 100644 --- a/migration/file.c +++ b/migration/file.c @@ -84,12 +84,19 @@ void file_start_outgoing_migration(MigrationState *s, trace_migration_file_outgoing(filename); - fioc = qio_channel_file_new_path(filename, O_CREAT | O_WRONLY | O_TRUNC, - 0600, errp); + fioc = qio_channel_file_new_path(filename, O_CREAT | O_WRONLY, 0600, errp); if (!fioc) { return; } + if (ftruncate(fioc->fd, offset)) { + error_setg_errno(errp, errno, + "failed to truncate migration file to offset %" PRIx64, + offset); + object_unref(OBJECT(fioc)); + return; + } + outgoing_args.fname = g_strdup(filename); ioc = QIO_CHANNEL(fioc);