From: Eric Sandeen Subject: Re: Bug in mount options handling in EXT4? Date: Wed, 04 Feb 2015 21:57:24 -0600 Message-ID: <54D2EA24.70206@redhat.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Cc: linux-ext4@vger.kernel.org To: Enrico Mioso , linux-kernel@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:36982 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751105AbbBED52 (ORCPT ); Wed, 4 Feb 2015 22:57:28 -0500 In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org List-ID: On 2/4/15 9:22 PM, Enrico Mioso wrote: > Hello guys. > I noticed from some time, that I can make mount options accumulate simply continously repeating them. > By typing: > sudo mount -t ext4 -o rw,noatime,nobarrier,nobarrier,nobarrier, ... > I can get: > $ dmesg | tail > [ 216.075581] EXT4-fs (sdb): mounted filesystem without journal. Opts: nobarrier > [ 472.851105] snd_hda_intel 0000:00:1b.0: IRQ timing workaround is activated for card #0. Suggest a bigger bdl_pos_adj. > [41950.250515] EXT4-fs (sdc1): re-mounted. Opts: nobarrier,nobarrier > [42093.049879] EXT4-fs (sdc1): re-mounted. Opts: nobarrier,nobarrier > [42095.673967] EXT4-fs (sdc1): re-mounted. Opts: nobarrier,nobarrier > [42095.954595] EXT4-fs (sdc1): re-mounted. Opts: nobarrier,nobarrier > [42096.220220] EXT4-fs (sdc1): re-mounted. Opts: nobarrier,nobarrier > [42103.212371] EXT4-fs (sdc1): re-mounted. Opts: nobarrier,nobarrier,nobarrier > [42128.137609] EXT4-fs (sdc1): re-mounted. Opts: nobarrier,nobarrier,nobarrier,nobarrier,nobarrier,nobarrier,nobarrier > [42144.960612] EXT4-fs (sdc1): re-mounted. Opts: nobarrier,nobarrier,nobarrier,nobarrier,nobarrier,nobarrier,nobarrier,nobarrier,nobarrier,nobarrier,nobarrier,nobarrier,nobarrier Hm, yes, it's really only cosmetic in that printk. > But the problem seems limited to the filesystem messages / something like that: > $ cat /proc/mounts ... > /dev/sdc1 /mnt/trekstor ext4 rw,noatime,nobarrier 0 0 Yep, because when this is printed, it simply looks at the set option flags, and essentially prints the option name once for each (non-default) flag that is set. What we probably would want is something similar to that code (in _ext4_show_options) which is more generic, and could generate a string for use in the remount case as well. -Eric