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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 245F6C6FD1D for ; Tue, 21 Mar 2023 17:20:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230500AbjCURUC (ORCPT ); Tue, 21 Mar 2023 13:20:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56494 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230498AbjCURTx (ORCPT ); Tue, 21 Mar 2023 13:19:53 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C04FC19AE; Tue, 21 Mar 2023 10:19:46 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 12C5661D55; Tue, 21 Mar 2023 17:19:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2BFA4C433EF; Tue, 21 Mar 2023 17:19:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1679419184; bh=hvCgy/WFbjzmT9vviDRBBlhBz4fmojTYN1wTRwP7718=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=MD4O3cmB+4/VQSR4jsZRfpRnQ01PJaSVnBusj8iA0wDmo6q8V6Ezagi2Tdswxx8Go ag1n6nLYEaqJAkFggk5PVwTM0lXuuaZ/eCXN3RyEtCPzTniWlHR2Ld7UcFDiN3PwA3 lLC4pbjHvGSbore2NRYLxSlk/y6hSp3qKsAm3dJ7ExU+TAU4j2OeB74n+fgAGSG0Yf Ub39gNk+ANNdrzzwsDIrIRvQSzEcWCG2nMX0nicBcCBzJm3ZzH/iTDFTxhaYbx8mlj vigTT7r6rsC34g0GSFZS2NncXbFA/MtAMaQEYZImmKfUSwMhftl0MjXlZdXMuX6DSZ w8ICsPBqFoLcA== Date: Tue, 21 Mar 2023 18:19:38 +0100 From: Christian Brauner To: Luis Chamberlain Cc: Yangtao Li , Alexander Viro , Andrew Morton , Kees Cook , Iurii Zaikin , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH] fs/drop_caches: move drop_caches sysctls into its own file Message-ID: <20230321171938.z5seopfethaworsm@wittgenstein> References: <20230321130908.6972-1-frank.li@vivo.com> <20230321142836.l6pymt4ygg2qhfvn@wittgenstein> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 21, 2023 at 09:39:41AM -0700, Luis Chamberlain wrote: > On Tue, Mar 21, 2023 at 03:28:36PM +0100, Christian Brauner wrote: > > On Tue, Mar 21, 2023 at 09:09:07PM +0800, Yangtao Li wrote: > > > This moves the fs/drop_caches.c respective sysctls to its own file. > > > > > > Signed-off-by: Yangtao Li > > > --- > > > fs/drop_caches.c | 25 ++++++++++++++++++++++--- > > > include/linux/mm.h | 6 ------ > > > kernel/sysctl.c | 9 --------- > > > 3 files changed, 22 insertions(+), 18 deletions(-) > > > > > > diff --git a/fs/drop_caches.c b/fs/drop_caches.c > > > index e619c31b6bd9..3032b83ce6f2 100644 > > > --- a/fs/drop_caches.c > > > +++ b/fs/drop_caches.c > > > @@ -12,8 +12,7 @@ > > > #include > > > #include "internal.h" > > > > > > -/* A global variable is a bit ugly, but it keeps the code simple */ > > > -int sysctl_drop_caches; > > > +static int sysctl_drop_caches; > > > > > > static void drop_pagecache_sb(struct super_block *sb, void *unused) > > > { > > > @@ -47,7 +46,7 @@ static void drop_pagecache_sb(struct super_block *sb, void *unused) > > > iput(toput_inode); > > > } > > > > > > -int drop_caches_sysctl_handler(struct ctl_table *table, int write, > > > +static int drop_caches_sysctl_handler(struct ctl_table *table, int write, > > > void *buffer, size_t *length, loff_t *ppos) > > > { > > > int ret; > > > @@ -75,3 +74,23 @@ int drop_caches_sysctl_handler(struct ctl_table *table, int write, > > > } > > > return 0; > > > } > > > + > > > +static struct ctl_table drop_caches_table[] = { > > > + { > > > + .procname = "drop_caches", > > > + .data = &sysctl_drop_caches, > > > + .maxlen = sizeof(int), > > > + .mode = 0200, > > > + .proc_handler = drop_caches_sysctl_handler, > > > + .extra1 = SYSCTL_ONE, > > > + .extra2 = SYSCTL_FOUR, > > > + }, > > > + {} > > > +}; > > > + > > > +static int __init drop_cache_init(void) > > > +{ > > > + register_sysctl_init("vm", drop_caches_table); > > > > Does this belong under mm/ or fs/? > > To not break old userspace it must be kept under "vm" because the > patch author is moving it from the kernel/sysctl.c table which used > the "vm" table. > > Moving it to "fs" would be a highly functional change which should > require review from maintainers it would not break existing userspace > expecations. No, I was asking whether this belongs under the fs/ or mm/ directory. But I misread the patch. I thought at first, that the patch moved the file from the mm/ to the fs/ directory. But that's obviously not the case... So ignore me.