From patchwork Wed Aug 24 13:59:46 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 600338 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 alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (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 EEEA7C38142 for ; Wed, 24 Aug 2022 14:01:26 +0000 (UTC) Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id 42C3015C2; Wed, 24 Aug 2022 16:00:35 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 42C3015C2 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1661349685; bh=KWnwJ1zMa3C2CDw6Y/OMLmmwDWaJ+biZe3MkwUbZHYs=; h=From:To:Subject:Date:Cc:List-Id:List-Unsubscribe:List-Archive: List-Post:List-Help:List-Subscribe:From; b=PcdwNZJ+kRvAhfM1IX29qoi1Z3c4bbEGxHLKHSuQ4J8JSVEnrqwjBJ6GHytE+4Ptu hVeatg8952Tl/N3GexxKb40ZNZSn2l1Bm+Q0djFwYMbwWnhEC3tK5iqsDxhtJtyuMu M5YhzQnoa5NS/mHSyAbWz32DnQKSVyODbM+HJFvo= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id 86AF0F80508; Wed, 24 Aug 2022 16:00:08 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 3CF32F8014E; Wed, 24 Aug 2022 16:00:07 +0200 (CEST) Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id 153E1F8014E for ; Wed, 24 Aug 2022 16:00:01 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 153E1F8014E Authentication-Results: alsa1.perex.cz; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="xYytor4R" 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 78BE9617CA; Wed, 24 Aug 2022 13:59:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 65A3EC433D7; Wed, 24 Aug 2022 13:59:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661349598; bh=KWnwJ1zMa3C2CDw6Y/OMLmmwDWaJ+biZe3MkwUbZHYs=; h=From:To:Cc:Subject:Date:From; b=xYytor4RJ8GRoHDLUA3TaZ9L/xtJ0TSzUzd8eYZwFZUYTlZJoyJzIX6VPNQ4kWlvB /mEkcpnn+u4OEMEyOfh3v66v2TtHwlgpU7ErpY+5PPGzX5QJL9s2ECgzO8NG4T4p10 ECDFw+dnybc0XE1nrvBqsyelkp3AwXbRJSEyI2sQ= From: Greg Kroah-Hartman To: alsa-devel@alsa-project.org Subject: [PATCH v2 1/6] sysfs: do not create empty directories if no attributes are present Date: Wed, 24 Aug 2022 15:59:46 +0200 Message-Id: <20220824135951.3604059-1-gregkh@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2703; i=gregkh@linuxfoundation.org; h=from:subject; bh=KWnwJ1zMa3C2CDw6Y/OMLmmwDWaJ+biZe3MkwUbZHYs=; b=owGbwMvMwCRo6H6F97bub03G02pJDMlseleWz0p77dt8m1tRzqymifO7SvSa+rS3M/3+ef91PVd/ 565YRywLgyATg6yYIsuXbTxH91ccUvQytD0NM4eVCWQIAxenAExkvwDDPPUPRss8Dk0ItLX7e80gh0 32681eC4YFM9ZNVL4f/e7no65TiZp5vyfVvXaWAwA= X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Cc: Greg Kroah-Hartman , Pierre-Louis Bossart , linux-kernel@vger.kernel.org, Vinod Koul , Sanyog Kale , Bard Liao X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: "Alsa-devel" When creating an attribute group, if it is named a subdirectory is created and the sysfs files are placed into that subdirectory. If no files are created, normally the directory would still be present, but it would be empty. Clean this up by removing the directory if no files were successfully created in the group at all. Cc: Vinod Koul Cc: Bard Liao Cc: Pierre-Louis Bossart Cc: Sanyog Kale Cc: alsa-devel@alsa-project.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- v2: new patch Note, totally untested! The following soundwire patches will need this, if a soundwire developer could test this out, it would be most apreciated. fs/sysfs/group.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c index eeb0e3099421..9fe0b47db47f 100644 --- a/fs/sysfs/group.c +++ b/fs/sysfs/group.c @@ -31,12 +31,14 @@ static void remove_files(struct kernfs_node *parent, kernfs_remove_by_name(parent, (*bin_attr)->attr.name); } +/* returns -ERROR if error, or >= 0 for number of files actually created */ static int create_files(struct kernfs_node *parent, struct kobject *kobj, kuid_t uid, kgid_t gid, const struct attribute_group *grp, int update) { struct attribute *const *attr; struct bin_attribute *const *bin_attr; + int files_created = 0; int error = 0, i; if (grp->attrs) { @@ -65,6 +67,8 @@ static int create_files(struct kernfs_node *parent, struct kobject *kobj, gid, NULL); if (unlikely(error)) break; + + files_created++; } if (error) { remove_files(parent, grp); @@ -95,12 +99,15 @@ static int create_files(struct kernfs_node *parent, struct kobject *kobj, NULL); if (error) break; + files_created++; } if (error) remove_files(parent, grp); } exit: - return error; + if (error) + return error; + return files_created; } @@ -146,10 +153,16 @@ static int internal_create_group(struct kobject *kobj, int update, kn = kobj->sd; kernfs_get(kn); error = create_files(kn, kobj, uid, gid, grp, update); - if (error) { + if (error <= 0) { + /* + * If an error happened _OR_ if no files were created in the + * attribute group, and we have a name for this group, delete + * the name so there's not an empty directory. + */ if (grp->name) kernfs_remove(kn); - } + } else + error = 0; kernfs_put(kn); if (grp->name && update)