Re: [PATCH v2 1/6] fs: Add case sensitivity info to file_kattr

[Chuck Lever]

On Thu, Dec 11, 2025, at 6:41 PM, Eric Biggers wrote:
> On Thu, Dec 11, 2025 at 10:21:11AM -0500, Chuck Lever wrote:
>> +/* Values stored in the low-order byte */
>> +enum fileattr_case_folding {
>> +	/* Code points are compared directly with no case folding. */
>> +	FILEATTR_CASEFOLD_NONE = 0,
>> +
>> +	/* ASCII case-insensitive: A-Z are treated as a-z. */
>> +	FILEATTR_CASEFOLD_ASCII,
>> +
>> +	/* Unicode case-insensitive matching. */
>> +	FILEATTR_CASEFOLD_UNICODE,
>> +};
>
> What does "Unicode case-insensitive matching" mean?  There are many
> different things it could mean: there are multiple types of Unicode
> normalization, Unicode case-folding, NTFS's upper case table, etc.
> There are also multiple versions of each.

This is left over from the RFC version of the series, and can be removed.


> I see you're proposing that ext4, fat, and ntfs3 all set
> FILEATTR_CASEFOLD_UNICODE, at least in some cases.
>
> That seems odd, since they don't do the matching the same way.

The purpose of this series is to design the VFS infrastructure. Exactly what
it reports is up to folks who actually understand i18n.


-- 
Chuck Lever