linux-kernel - Re: [PATCHv2] fat: add config option to set UTF-8 mount option by default

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 23 Mar 2016 13:27:43 +0100
From:	Geert Uytterhoeven <geert@...ux-m68k.org>
To:	Josh Boyer <jwboyer@...oraproject.org>
Cc:	"Maciej S. Szmigiero" <mail@...iej.szmigiero.name>,
	OGAWA Hirofumi <hirofumi@...l.parknet.co.jp>,
	Jonathan Corbet <corbet@....net>,
	"linux-doc@...r.kernel.org" <linux-doc@...r.kernel.org>,
	linux-kernel <linux-kernel@...r.kernel.org>
Subject: Re: [PATCHv2] fat: add config option to set UTF-8 mount option by default

On Wed, Mar 23, 2016 at 12:28 PM, Josh Boyer <jwboyer@...oraproject.org> wrote:
> On Wed, Mar 23, 2016 at 4:17 AM, Geert Uytterhoeven
> <geert@...ux-m68k.org> wrote:
>> On Tue, Mar 8, 2016 at 2:53 PM, Maciej S. Szmigiero
>> <mail@...iej.szmigiero.name> wrote:
>>> FAT has long supported its own default file name encoding
>>> config setting, separate from CONFIG_NLS_DEFAULT.
>>>
>>> However, if UTF-8 encoded file names are desired FAT
>>> character set should not be set to utf8 since this would
>>> make file names case sensitive even if case insensitive
>>> matching is requested.
>>> Instead, "utf8" mount options should be provided to enable
>>> UTF-8 file names in FAT file system.
>>>
>>> Unfortunately, there was no possibility to set the default
>>> value of this option so on UTF-8 system "utf8" mount option
>>> had to be added manually to most FAT mounts.
>>>
>>> This patch adds config option to set such default value.
>>>
>>> Signed-off-by: Maciej S. Szmigiero <mail@...iej.szmigiero.name>
>>
>>> --- a/fs/fat/Kconfig
>>> +++ b/fs/fat/Kconfig
>>> @@ -93,8 +93,24 @@ config FAT_DEFAULT_IOCHARSET
>>>           that most of your FAT filesystems use, and can be overridden
>>>           with the "iocharset" mount option for FAT filesystems.
>>>           Note that "utf8" is not recommended for FAT filesystems.
>>> -         If unsure, you shouldn't set "utf8" here.
>>> +         If unsure, you shouldn't set "utf8" here - select the next option
>>> +         instead if you would like to use UTF-8 encoded file names by default.
>>>           See <file:Documentation/filesystems/vfat.txt> for more information.
>>>
>>>           Enable any character sets you need in File Systems/Native Language
>>>           Support.
>>> +
>>> +config FAT_DEFAULT_UTF8
>>> +       bool "Enable FAT UTF-8 option by default"
>>> +       depends on VFAT_FS
>>> +       default n
>>> +       help
>>> +         Set this if you would like to have "utf8" mount option set
>>> +         by default when mounting FAT filesystems.
>>> +
>>> +         Even if you say Y here can always disable UTF-8 for
>>> +         particular mount by adding "utf8=0" to mount options.
>>> +
>>> +         Say Y if you use UTF-8 encoding for file names, N otherwise.
>>> +
>>> +         See <file:Documentation/filesystems/vfat.txt> for more information.
>>
>> What's the recommended value of CONFIG_FAT_DEFAULT_UTF8 for
>> a (distro) defconfig?
>
> Yes, I'm curious about this as well.  My initial assumption is to
> leave it off, given that if you turn it on when it wasn't previously
> it will change the behavior.  I would also assume that is why it is
> marked as default n.

"default n" is superfluous, as all options default to "n" in the absence
of a default specifier.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@...ux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds