From patchwork Fri Jul 21 10:20:59 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fam Zheng X-Patchwork-Id: 792015 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=2001:4830:134:3::11; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3xDRdp39rjz9t0F for ; Fri, 21 Jul 2017 20:22:05 +1000 (AEST) Received: from localhost ([::1]:42143 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dYV4J-0005Bp-2I for incoming@patchwork.ozlabs.org; Fri, 21 Jul 2017 06:21:59 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58289) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dYV3b-00057F-8V for qemu-devel@nongnu.org; Fri, 21 Jul 2017 06:21:16 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dYV3a-00070D-90 for qemu-devel@nongnu.org; Fri, 21 Jul 2017 06:21:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56640) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dYV3X-0006wg-Vg; Fri, 21 Jul 2017 06:21:12 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 08E9152748; Fri, 21 Jul 2017 10:21:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 08E9152748 Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=famz@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 08E9152748 Received: from lemon.redhat.com (ovpn-12-28.pek2.redhat.com [10.72.12.28]) by smtp.corp.redhat.com (Postfix) with ESMTP id B63128B30B; Fri, 21 Jul 2017 10:21:08 +0000 (UTC) From: Fam Zheng To: qemu-devel@nongnu.org Date: Fri, 21 Jul 2017 18:20:59 +0800 Message-Id: <20170721102059.14663-3-famz@redhat.com> In-Reply-To: <20170721102059.14663-1-famz@redhat.com> References: <20170721102059.14663-1-famz@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Fri, 21 Jul 2017 10:21:11 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH 2/2] file-posix: Do runtime check for ofd lock API X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , qemu-block@nongnu.org, jsnow@redhat.com, Andrew Baumann , Max Reitz Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" It is reported that on Windows Subsystem for Linux, ofd operations fail with -EINVAL. In other words, QEMU binary built with system headers that exports F_OFD_SETLK doesn't necessarily run in an environment that actually supports it: $ qemu-system-aarch64 ... -drive file=test.vhdx,if=none,id=hd0 \ -device virtio-blk-pci,drive=hd0 qemu-system-aarch64: -drive file=test.vhdx,if=none,id=hd0: Failed to unlock byte 100 qemu-system-aarch64: -drive file=test.vhdx,if=none,id=hd0: Failed to unlock byte 100 qemu-system-aarch64: -drive file=test.vhdx,if=none,id=hd0: Failed to lock byte 100 Let's do a runtime check to cope with that. Reported-by: Andrew Baumann Signed-off-by: Fam Zheng Reviewed-by: Eric Blake Tested-By: Andrew Baumann --- block/file-posix.c | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-) diff --git a/block/file-posix.c b/block/file-posix.c index cfbb236f6f..5ddf2729eb 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -457,22 +457,19 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, switch (locking) { case ON_OFF_AUTO_ON: s->use_lock = true; -#ifndef F_OFD_SETLK - fprintf(stderr, - "File lock requested but OFD locking syscall is unavailable, " - "falling back to POSIX file locks.\n" - "Due to the implementation, locks can be lost unexpectedly.\n"); -#endif + if (!qemu_has_ofd_lock()) { + fprintf(stderr, + "File lock requested but OFD locking syscall is " + "unavailable, falling back to POSIX file locks.\n" + "Due to the implementation, locks can be lost " + "unexpectedly.\n"); + } break; case ON_OFF_AUTO_OFF: s->use_lock = false; break; case ON_OFF_AUTO_AUTO: -#ifdef F_OFD_SETLK - s->use_lock = true; -#else - s->use_lock = false; -#endif + s->use_lock = qemu_has_ofd_lock(); break; default: abort();