linux-kernel - Re: [PATCH v6 6/9] ovl: Set case-insensitive dentry operations for ovl sb

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Message-ID: <87wm6r4pbf.fsf@mailhost.krisman.be>
Date: Mon, 25 Aug 2025 07:24:04 -0400
From: Gabriel Krisman Bertazi <gabriel@...sman.be>
To: André Almeida <andrealmeid@...lia.com>
Cc: Miklos Szeredi <miklos@...redi.hu>,  Amir Goldstein
 <amir73il@...il.com>,  Theodore Tso <tytso@....edu>,
  linux-unionfs@...r.kernel.org,  linux-kernel@...r.kernel.org,
  linux-fsdevel@...r.kernel.org,  Alexander Viro <viro@...iv.linux.org.uk>,
  Christian Brauner <brauner@...nel.org>,  Jan Kara <jack@...e.cz>,
  kernel-dev@...lia.com
Subject: Re: [PATCH v6 6/9] ovl: Set case-insensitive dentry operations for
 ovl sb

André Almeida <andrealmeid@...lia.com> writes:

> For filesystems with encoding (i.e. with case-insensitive support), set
> the dentry operations for the super block as ovl_dentry_ci_operations.
>
> Reviewed-by: Amir Goldstein <amir73il@...il.com>
> Signed-off-by: André Almeida <andrealmeid@...lia.com>
> ---
> Changes in v6:
> - Fix kernel bot warning: unused variable 'ofs'
> ---
>  fs/overlayfs/super.c | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
>
> diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
> index b1dbd3c79961094d00c7f99cc622e515d544d22f..8db4e55d5027cb975fec9b92251f62fe5924af4f 100644
> --- a/fs/overlayfs/super.c
> +++ b/fs/overlayfs/super.c
> @@ -161,6 +161,16 @@ static const struct dentry_operations ovl_dentry_operations = {
>  	.d_weak_revalidate = ovl_dentry_weak_revalidate,
>  };
>  
> +#if IS_ENABLED(CONFIG_UNICODE)
> +static const struct dentry_operations ovl_dentry_ci_operations = {
> +	.d_real = ovl_d_real,
> +	.d_revalidate = ovl_dentry_revalidate,
> +	.d_weak_revalidate = ovl_dentry_weak_revalidate,
> +	.d_hash = generic_ci_d_hash,
> +	.d_compare = generic_ci_d_compare,
> +};
> +#endif
> +
>  static struct kmem_cache *ovl_inode_cachep;
>  
>  static struct inode *ovl_alloc_inode(struct super_block *sb)
> @@ -1332,6 +1342,19 @@ static struct dentry *ovl_get_root(struct super_block *sb,
>  	return root;
>  }
>  
> +static void ovl_set_d_op(struct super_block *sb)
> +{
> +#if IS_ENABLED(CONFIG_UNICODE)
> +	struct ovl_fs *ofs = sb->s_fs_info;
> +
> +	if (ofs->casefold) {
> +		set_default_d_op(sb, &ovl_dentry_ci_operations);
> +		return;
> +	}
> +#endif
> +	set_default_d_op(sb, &ovl_dentry_operations);
> +}
> +
>  int ovl_fill_super(struct super_block *sb, struct fs_context *fc)
>  {
>  	struct ovl_fs *ofs = sb->s_fs_info;
> @@ -1443,6 +1466,8 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc)
>  	if (IS_ERR(oe))
>  		goto out_err;
>  
> +	ovl_set_d_op(sb);
> +

Absolutely minor, but fill_super is now calling
set_default_d_op(sb, &ovl_dentry_operations) twice, once here and once
at the beginning of the function.  You can remove the original call.

>  	/* If the upper fs is nonexistent, we mark overlayfs r/o too */
>  	if (!ovl_upper_mnt(ofs))
>  		sb->s_flags |= SB_RDONLY;

-- 
Gabriel Krisman Bertazi