From patchwork Wed Oct 4 11:19:16 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mateusz Guzik X-Patchwork-Id: 13408646 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A43FFE7B5EE for ; Wed, 4 Oct 2023 11:19:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242251AbjJDLTo (ORCPT ); Wed, 4 Oct 2023 07:19:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59064 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242245AbjJDLTn (ORCPT ); Wed, 4 Oct 2023 07:19:43 -0400 Received: from mail-wm1-x32a.google.com (mail-wm1-x32a.google.com [IPv6:2a00:1450:4864:20::32a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 25ED6E5; Wed, 4 Oct 2023 04:19:39 -0700 (PDT) Received: by mail-wm1-x32a.google.com with SMTP id 5b1f17b1804b1-40675f06f1fso4630435e9.1; Wed, 04 Oct 2023 04:19:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1696418377; x=1697023177; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=LdSMOqyI/Qm2nBy4+9Nq5mSXBIbAfD+yRNlJMg5NxcI=; b=nozvkPIcSknqpkVEgY2Rzlp2QcitOBor26uqinVrTN26tfxYvkkcFhcVwKBpM3sHp3 disW0hQSFrJpUzsDnLS6iD7XGQn3xfVCQrZnhWY/pm+WzZi8phgP/sSHZa/nH5XWRK+z 4qLS6OUQxt7ODKauSb6cLeLypryGm06dTgoeotMyFJlPaBSN67c07hf/whRwjOzrBaEa iOr+lHonaiVXeFlb4APqlAd1jvuStTgTfd3fatBcgFiKhHa+r9kuCJOmYe+QjGmSSi6x Svytw22uj9z4pAksIyHlvbTs09eAYEX/aDnTkRCJgL1fzB31W37HyRjQaMMqo00YlsOS NPmw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1696418377; x=1697023177; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=LdSMOqyI/Qm2nBy4+9Nq5mSXBIbAfD+yRNlJMg5NxcI=; b=PLhP3deebjIPjQQIE2hoKd9AJe+VdbgMN4Qbvt1wsd9y5jE4DFzTBLSTKavS9ZLQQf 7tt2BgvvBRk5aRXEkRyh9CGYUu9QeZIv8un897C784pQYizsbHbfjcGuT3+aZrElwGZG L48rhtmlFdZXM1R06UolghPxktMwwUVxBQ/eFFt5fdY0BuVBcoSbIYTfSUm1jEh2MTHf jBTPEHZbmpbQbpqCRD+M2PDlt/8jp9Lh060UtBwtEJO2lgv7542a1/MejMpg39Y/7Jiq mGRGbUQGqItkCaVNSxZW2sIGlWfefLjShMb9Wj2HFX2MqoFtYyYpUVfhvZKjBnlvGQcs tMXQ== X-Gm-Message-State: AOJu0YzAeODohOLO44wegOsf29YYoHsgdi7026hDK18xkaRziud3q2az lxwTvV9j/qrFK4PNdpCz7fkXax7OQSM= X-Google-Smtp-Source: AGHT+IGfm/7SJFfAziYdhTOsE+/Het/A9KoBfNR0Xm8lxr9whAquAp73f8w7asbiyaeE/YD43LVORg== X-Received: by 2002:a05:600c:4689:b0:405:29ba:9b5c with SMTP id p9-20020a05600c468900b0040529ba9b5cmr4403104wmo.16.1696418377246; Wed, 04 Oct 2023 04:19:37 -0700 (PDT) Received: from f.. (cst-prg-67-191.cust.vodafone.cz. [46.135.67.191]) by smtp.gmail.com with ESMTPSA id o16-20020adfead0000000b003266ece0fe2sm3761527wrn.98.2023.10.04.04.19.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Oct 2023 04:19:36 -0700 (PDT) From: Mateusz Guzik To: brauner@kernel.org Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Mateusz Guzik Subject: [PATCH 2/2] vfs: stop counting on gcc not messing with mnt_expiry_mark if not asked Date: Wed, 4 Oct 2023 13:19:16 +0200 Message-Id: <20231004111916.728135-3-mjguzik@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231004111916.728135-1-mjguzik@gmail.com> References: <20231004111916.728135-1-mjguzik@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org So happens it already was not doing it, but there is no need to "hope" as indicated in the comment. No changes in generated assembly. Signed-off-by: Mateusz Guzik --- fs/namespace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index e157efc54023..d785bcb75111 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1344,9 +1344,9 @@ void mntput(struct vfsmount *mnt) { if (mnt) { struct mount *m = real_mount(mnt); - /* avoid cacheline pingpong, hope gcc doesn't get "smart" */ + /* avoid cacheline pingpong */ if (unlikely(m->mnt_expiry_mark)) - m->mnt_expiry_mark = 0; + WRITE_ONCE(m->mnt_expiry_mark, 0); mntput_no_expire(m); } }