From patchwork Fri Mar 7 22:16:31 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 14007242 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 A487EC28B28 for ; Fri, 7 Mar 2025 22:17:43 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tqg0U-0002DZ-QZ; Fri, 07 Mar 2025 17:17:26 -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 1tqg05-0001v4-Bf for qemu-devel@nongnu.org; Fri, 07 Mar 2025 17:17:01 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tqg02-0007oz-OU for qemu-devel@nongnu.org; Fri, 07 Mar 2025 17:17:00 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1741385818; 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=EVbiYipccsLmBbLc7DH923fS89CDAwHcTdukc84RR4Y=; b=YYL/bnkGMOdUlVY6hxGVsQrhPQoALl4Det8hoH9l2mGLPugrg39UUn/VVtV5Ig2tuDSXnO hi4e31aOa1e7cmtiLPV/u6DN9bwBvoTvO9epUsJc3+GoxdR6Ng98XJSaGIeeeUybIgC890 JFhytOnxGjOrJlW/Qsgb6eq+WAN53K0= Received: from mx-prod-mc-03.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-658-fCezoiiwPPGs7yNOFZB_Pg-1; Fri, 07 Mar 2025 17:16:55 -0500 X-MC-Unique: fCezoiiwPPGs7yNOFZB_Pg-1 X-Mimecast-MFC-AGG-ID: fCezoiiwPPGs7yNOFZB_Pg_1741385814 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (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-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 21A2A19560BC; Fri, 7 Mar 2025 22:16:54 +0000 (UTC) Received: from merkur.redhat.com (unknown [10.45.226.27]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id B81D018009BC; Fri, 7 Mar 2025 22:16:51 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Cc: kwolf@redhat.com, stefanha@redhat.com, pbonzini@redhat.com, afaria@redhat.com, hreitz@redhat.com, qemu-devel@nongnu.org Subject: [PATCH 2/5] block/io: Ignore FUA with cache.no-flush=on Date: Fri, 7 Mar 2025 23:16:31 +0100 Message-ID: <20250307221634.71951-3-kwolf@redhat.com> In-Reply-To: <20250307221634.71951-1-kwolf@redhat.com> References: <20250307221634.71951-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Received-SPF: pass client-ip=170.10.133.124; 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_H2=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=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+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org For block drivers that don't advertise FUA support, we already call bdrv_co_flush(), which considers BDRV_O_NO_FLUSH. However, drivers that do support FUA still see the FUA flag with BDRV_O_NO_FLUSH and get the associated performance penalty that cache.no-flush=on was supposed to avoid. Clear FUA for write requests if BDRV_O_NO_FLUSH is set. Signed-off-by: Kevin Wolf Reviewed-by: Stefan Hajnoczi --- block/io.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/block/io.c b/block/io.c index d369b994df..1ba8d1aeea 100644 --- a/block/io.c +++ b/block/io.c @@ -1058,6 +1058,10 @@ bdrv_driver_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes, return -ENOMEDIUM; } + if (bs->open_flags & BDRV_O_NO_FLUSH) { + flags &= ~BDRV_REQ_FUA; + } + if ((flags & BDRV_REQ_FUA) && (~bs->supported_write_flags & BDRV_REQ_FUA)) { flags &= ~BDRV_REQ_FUA;