Re: [f2fs-dev] [PATCH v15 6/9] ext4: Log error when lookup of encoded dentry fails

[Gabriel Krisman Bertazi]

Eric Biggers <ebiggers@xxxxxxxxxx> writes:

> On Tue, Apr 02, 2024 at 06:48:39PM +0300, Eugen Hristev via Linux-f2fs-devel wrote:
>> From: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>
>> 

> I'm seeing this error when the volume is *not* in strict mode and a file has a
> name that is not valid UTF-8.  That doesn't seem to be working as
> intended.
>
>     mkfs.ext4 -F -O casefold /dev/vdb
>     mount /dev/vdb /mnt
>     mkdir /mnt/dir
>     chattr +F /mnt/dir
>     touch /mnt/dir/$'\xff'

Yes.  This should work without warnings.  When not in strict mode,
/mnt/dir/$'\xff' is just a valid filename which can only be
looked up with an exact-match name-under-lookup.

The issue is that we must propagate errors from utf8_strncasecmp in
generic_ci_match only if we are in strict mode.  If not on strict mode, we
need to return not-match on error.

-- 
Gabriel Krisman Bertazi