Re: [PATCH 2/5] ext4: Simplify the handling of chached insensitive names

[Eric Biggers <ebiggers@kernel.org>]

On Mon, Mar 21, 2022 at 11:00:01PM -0400, Gabriel Krisman Bertazi wrote:
> Keeping it as qstr avoids the unnecessary conversion in ext4_match
> 
> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
> ---
>  fs/ext4/ext4.h  |  2 +-
>  fs/ext4/namei.c | 23 +++++++++++------------
>  2 files changed, 12 insertions(+), 13 deletions(-)
> 
> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> index bcd3b9bf8069..46e729ce7b35 100644
> --- a/fs/ext4/ext4.h
> +++ b/fs/ext4/ext4.h
> @@ -2484,7 +2484,7 @@ struct ext4_filename {
>  	struct fscrypt_str crypto_buf;
>  #endif
>  #if IS_ENABLED(CONFIG_UNICODE)
> -	struct fscrypt_str cf_name;
> +	struct qstr cf_name;
>  #endif
>  };
>  
> diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
> index 24ea3bb446d0..8976e5a28c73 100644
> --- a/fs/ext4/namei.c
> +++ b/fs/ext4/namei.c
> @@ -1382,28 +1382,29 @@ static int ext4_ci_compare(const struct inode *parent, const struct qstr *name,
>  int ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname,
>  				  struct ext4_filename *name)
>  {
> -	struct fscrypt_str *cf_name = &name->cf_name;
> +	struct qstr *cf_name = &name->cf_name;
> +	unsigned char *buf;
>  	struct dx_hash_info *hinfo = &name->hinfo;
>  	int len;
>  
>  	if (!IS_CASEFOLDED(dir) || !dir->i_sb->s_encoding ||
>  	    (IS_ENCRYPTED(dir) && !fscrypt_has_encryption_key(dir))) {
> -		cf_name->name = NULL;
> +		name->cf_name.name = NULL;
>  		return 0;
>  	}

Why not keep "cf_name->name = NULL;" above?

- Eric