From patchwork Tue Jan 18 16:05:41 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 533258 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 E6459C433EF for ; Tue, 18 Jan 2022 16:07:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346316AbiARQHH (ORCPT ); Tue, 18 Jan 2022 11:07:07 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:38544 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346332AbiARQHE (ORCPT ); Tue, 18 Jan 2022 11:07:04 -0500 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 C60E0612ED; Tue, 18 Jan 2022 16:07:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CE5F7C00446; Tue, 18 Jan 2022 16:07:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1642522023; bh=kMDpxjCdg706EV3OMK18iNmKo7NJ4xqzejuxVw2I2lQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YOd1SpAMY4qeemSGE6hy9auIvhsj/vmiPC/XcnvydQNLLYQAC8VOL8mhcHPf6DEB6 QMBk0D/4GJJTNil9lYDAyjzDHJb1xLL/9grXACXeCG/yQrTH4ccQProAaBOcTKhWYL 2Pdwwuk0KmWEsT1N2XyVTnxBgzQ6PNr+XEoG+BXc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Christian Brauner , Al Viro , NeilBrown , Linus Torvalds Subject: [PATCH 5.4 02/15] devtmpfs regression fix: reconfigure on each mount Date: Tue, 18 Jan 2022 17:05:41 +0100 Message-Id: <20220118160450.143738373@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220118160450.062004175@linuxfoundation.org> References: <20220118160450.062004175@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: NeilBrown commit a6097180d884ddab769fb25588ea8598589c218c upstream. Prior to Linux v5.4 devtmpfs used mount_single() which treats the given mount options as "remount" options, so it updates the configuration of the single super_block on each mount. Since that was changed, the mount options used for devtmpfs are ignored. This is a regression which affect systemd - which mounts devtmpfs with "-o mode=755,size=4m,nr_inodes=1m". This patch restores the "remount" effect by calling reconfigure_single() Fixes: d401727ea0d7 ("devtmpfs: don't mix {ramfs,shmem}_fill_super() with mount_single()") Acked-by: Christian Brauner Cc: Al Viro Signed-off-by: NeilBrown Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- drivers/base/devtmpfs.c | 8 ++++++++ fs/super.c | 4 ++-- include/linux/fs_context.h | 2 ++ 3 files changed, 12 insertions(+), 2 deletions(-) --- a/drivers/base/devtmpfs.c +++ b/drivers/base/devtmpfs.c @@ -25,6 +25,7 @@ #include #include #include +#include #include #include "base.h" @@ -62,8 +63,15 @@ static struct dentry *public_dev_mount(s const char *dev_name, void *data) { struct super_block *s = mnt->mnt_sb; + int err; + atomic_inc(&s->s_active); down_write(&s->s_umount); + err = reconfigure_single(s, flags, data); + if (err < 0) { + deactivate_locked_super(s); + return ERR_PTR(err); + } return dget(s->s_root); } --- a/fs/super.c +++ b/fs/super.c @@ -1470,8 +1470,8 @@ struct dentry *mount_nodev(struct file_s } EXPORT_SYMBOL(mount_nodev); -static int reconfigure_single(struct super_block *s, - int flags, void *data) +int reconfigure_single(struct super_block *s, + int flags, void *data) { struct fs_context *fc; int ret; --- a/include/linux/fs_context.h +++ b/include/linux/fs_context.h @@ -135,6 +135,8 @@ extern int generic_parse_monolithic(stru extern int vfs_get_tree(struct fs_context *fc); extern void put_fs_context(struct fs_context *fc); extern void fc_drop_locked(struct fs_context *fc); +int reconfigure_single(struct super_block *s, + int flags, void *data); /* * sget() wrappers to be called from the ->get_tree() op.