Re: [PATCH v5 4/4] fs: unicode: Add utf8 module and a unicode layer
From: Gabriel Krisman Bertazi
Date: Mon Mar 29 2021 - 22:18:01 EST
Eric Biggers <ebiggers@xxxxxxxxxx> writes:
> On Tue, Mar 30, 2021 at 02:12:40AM +0530, Shreeya Patel wrote:
>> diff --git a/fs/unicode/Kconfig b/fs/unicode/Kconfig
>> index 2c27b9a5cd6c..ad4b837f2eb2 100644
>> --- a/fs/unicode/Kconfig
>> +++ b/fs/unicode/Kconfig
>> @@ -2,13 +2,26 @@
>> #
>> # UTF-8 normalization
>> #
>> +# CONFIG_UNICODE will be automatically enabled if CONFIG_UNICODE_UTF8
>> +# is enabled. This config option adds the unicode subsystem layer which loads
>> +# the UTF-8 module whenever any filesystem needs it.
>> config UNICODE
>> - bool "UTF-8 normalization and casefolding support"
>> + bool
>> +
>> +# utf8data.h_shipped has a large database table which is an auto-generated
>> +# decodification trie for the unicode normalization functions and it is not
>> +# necessary to carry this large table in the kernel.
>> +# Enabling UNICODE_UTF8 option will allow UTF-8 encoding to be built as a
>> +# module and this module will be loaded by the unicode subsystem layer only
>> +# when any filesystem needs it.
>> +config UNICODE_UTF8
>> + tristate "UTF-8 module"
>> help
>> Say Y here to enable UTF-8 NFD normalization and NFD+CF casefolding
>> support.
>> + select UNICODE
>
> This seems problematic; it allows users to set CONFIG_EXT4_FS=y (or
> CONFIG_F2FS_FS=y) but then CONFIG_UNICODE_UTF8=m. Then the filesystem won't
> work if the modules are located on the filesystem itself.
Hi Eric,
Isn't this a user problem? If the modules required to boot are on the
filesystem itself, you are in trouble. But, if that is the case, your
rootfs is case-insensitive and you gotta have utf8 as built-in or have
it in an early userspace.
> I think it should work analogously to CONFIG_FS_ENCRYPTION and
> CONFIG_FS_ENCRYPTION_ALGS. That is, CONFIG_UNICODE should be a user-selectable
> bool, and then the tristate symbols CONFIG_EXT4_FS and CONFIG_F2FS_FS should
> select the tristate symbol CONFIG_UNICODE_UTF8 if CONFIG_UNICODE.
--
Gabriel Krisman Bertazi