From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8CCBEC433DF for ; Thu, 20 Aug 2020 12:44:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 67AC822B4E for ; Thu, 20 Aug 2020 12:44:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597927483; bh=huCiChlyQVRz46fCpLZMtoHb1q8AdA7xw0fOzvyU1vQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=giIzN1Ex/WxZD28whlfqXfCXyCvMflpusmj6sUjyfXbhyAMpRcweRXPCIuag7oKHr VL4kYUlt+Maa7SRvN9zqUnNfJbdNRvvBT5Gh6T3bmWrvZZxsf8bT2HJbITXRtIoyWq oYf6Gu6SJ6F73W1f5GlfpXHNCHW+8OEKjpzkesv8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729756AbgHTMoi (ORCPT ); Thu, 20 Aug 2020 08:44:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:45620 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729217AbgHTJpp (ORCPT ); Thu, 20 Aug 2020 05:45:45 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CA2A922CF7; Thu, 20 Aug 2020 09:45:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597916735; bh=huCiChlyQVRz46fCpLZMtoHb1q8AdA7xw0fOzvyU1vQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1eHOYKEdIBlnsl/RxsJJWTFxHLBgFulWwT6kZWtZR7MKUbUyi7CwtZVFcaYjyWS/B uAstWPoP4WaGesCBuIBXOzp+lI+3l2+z+ItF2D5o0347VXUcYCPqhR6WZDyJlY6zNZ 1dHBVHb/bQ/Xd0AN0/J0AbfB7gZHXDUIAmJcHZV0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Sandeen , Josef Bacik , David Sterba Subject: [PATCH 5.4 028/152] btrfs: make sure SB_I_VERSION doesnt get unset by remount Date: Thu, 20 Aug 2020 11:19:55 +0200 Message-Id: <20200820091555.103552738@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200820091553.615456912@linuxfoundation.org> References: <20200820091553.615456912@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Josef Bacik commit faa008899a4db21a2df99833cb4ff6fa67009a20 upstream. There's some inconsistency around SB_I_VERSION handling with mount and remount. Since we don't really want it to be off ever just work around this by making sure we don't get the flag cleared on remount. There's a tiny cpu cost of setting the bit, otherwise all changes to i_version also change some of the times (ctime/mtime) so the inode needs to be synced. We wouldn't save anything by disabling it. Reported-by: Eric Sandeen CC: stable@vger.kernel.org # 5.4+ Signed-off-by: Josef Bacik Reviewed-by: David Sterba [ add perf impact analysis ] Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/super.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1852,6 +1852,12 @@ static int btrfs_remount(struct super_bl set_bit(BTRFS_FS_OPEN, &fs_info->flags); } out: + /* + * We need to set SB_I_VERSION here otherwise it'll get cleared by VFS, + * since the absence of the flag means it can be toggled off by remount. + */ + *flags |= SB_I_VERSION; + wake_up_process(fs_info->transaction_kthread); btrfs_remount_cleanup(fs_info, old_opts); return 0;