Re: [PATCH v12 4/4] ext4: Use generic casefolding support

[Eric Biggers]

On Sun, Sep 20, 2020 at 09:10:57PM -0400, Gabriel Krisman Bertazi wrote:
> Daniel Rosenberg <drosen@xxxxxxxxxx> writes:
> 
> > This switches ext4 over to the generic support provided in
> > the previous patch.
> >
> > Since casefolded dentries behave the same in ext4 and f2fs, we decrease
> > the maintenance burden by unifying them, and any optimizations will
> > immediately apply to both.
> >
> > Signed-off-by: Daniel Rosenberg <drosen@xxxxxxxxxx>
> > Reviewed-by: Eric Biggers <ebiggers@xxxxxxxxxx>
> >  
> >  #ifdef CONFIG_UNICODE
> > -	if (EXT4_SB(parent->i_sb)->s_encoding && IS_CASEFOLDED(parent)) {
> > +	if (parent->i_sb->s_encoding && IS_CASEFOLDED(parent)) {
> >  		if (fname->cf_name.name) {
> >  			struct qstr cf = {.name = fname->cf_name.name,
> >  					  .len = fname->cf_name.len};
> > @@ -2171,9 +2171,6 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
> >  	struct buffer_head *bh = NULL;
> >  	struct ext4_dir_entry_2 *de;
> >  	struct super_block *sb;
> > -#ifdef CONFIG_UNICODE
> > -	struct ext4_sb_info *sbi;
> > -#endif
> >  	struct ext4_filename fname;
> >  	int	retval;
> >  	int	dx_fallback=0;
> > @@ -2190,9 +2187,8 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
> >  		return -EINVAL;
> >  
> >  #ifdef CONFIG_UNICODE
> > -	sbi = EXT4_SB(sb);
> > -	if (ext4_has_strict_mode(sbi) && IS_CASEFOLDED(dir) &&
> > -	    sbi->s_encoding && utf8_validate(sbi->s_encoding, &dentry->d_name))
> > +	if (sb_has_strict_encoding(sb) && IS_CASEFOLDED(dir) &&
> > +	    sb->s_encoding && utf8_validate(sb->s_encoding, &dentry->d_name))
> >  		return -EINVAL;
> 
> hm, just noticed the sb->s_encoding check here is superfluous, since the
> has_strict_mode() cannot be true if !s_encoding.  Not related to this
> patch though.
> 
> Daniel, are you still working on getting this upstream?  The fscrypt
> support would be very useful for us. :)
> 
> In the hope this will get upstream, as its been flying for a while and
> looks correct.
> 
> Reviewed-by: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>

We couldn't get a response from Ted, so instead Jaegeuk has applied patches 1-3
to f2fs/dev for 5.10.  Hopefully Ted will take the ext4 patch for 5.11.

I believe that Daniel is planning to resend the actual encryption+casefolding
support soon, but initially only for f2fs since that will be ready first.

- Eric