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

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Message-ID: <CA+5PVA63GWcRWmpgJHyx3ea66mFSoNRRA9Wf+yY2KQeRvjy7KA@mail.gmail.com>
Date:	Wed, 23 Mar 2016 07:28:31 -0400
From:	Josh Boyer <jwboyer@...oraproject.org>
To:	Geert Uytterhoeven <geert@...ux-m68k.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 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.

josh