Re: [PATCH] erofs: code cleanup by removing ifdef macro surrounding

[Gao Xiang <hsiangkao@redhat.com>]

Hi Chengguang,

On Tue, May 26, 2020 at 05:03:43PM +0800, Chengguang Xu wrote:
> Define erofs_listxattr and erofs_xattr_handlers to NULL when
> CONFIG_EROFS_FS_XATTR is not enabled, then we can remove many
> ugly ifdef macros in the code.
> 
> Signed-off-by: Chengguang Xu <cgxu519@mykernel.net>
> ---
> Only compile tested.
> 
>  fs/erofs/inode.c | 6 ------
>  fs/erofs/namei.c | 2 --
>  fs/erofs/super.c | 4 +---
>  fs/erofs/xattr.h | 7 ++-----
>  4 files changed, 3 insertions(+), 16 deletions(-)
> 
> diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
> index 3350ab65d892..7dd4bbe9674f 100644
> --- a/fs/erofs/inode.c
> +++ b/fs/erofs/inode.c
> @@ -311,27 +311,21 @@ int erofs_getattr(const struct path *path, struct kstat *stat,
>  
>  const struct inode_operations erofs_generic_iops = {
>  	.getattr = erofs_getattr,
> -#ifdef CONFIG_EROFS_FS_XATTR
>  	.listxattr = erofs_listxattr,
> -#endif

It seems equivalent. And it seems ext2 and f2fs behave in the same way...
But I'm not sure whether we'd return 0 (if I didn't see fs/xattr.c by mistake)
or -EOPNOTSUPP here... Some thoughts about this?

Anyway, I'm fine with that if return 0 is okay here, but I'd like to know your
and Chao's thoughts about this... I will play with it later as well.

Reviewed-by: Gao Xiang <hsiangkao@redhat.com>

Thanks,
Gao Xiang

>  	.get_acl = erofs_get_acl,
>  };
>  
>  const struct inode_operations erofs_symlink_iops = {
>  	.get_link = page_get_link,
>  	.getattr = erofs_getattr,
> -#ifdef CONFIG_EROFS_FS_XATTR
>  	.listxattr = erofs_listxattr,
> -#endif
>  	.get_acl = erofs_get_acl,
>  };
>  
>  const struct inode_operations erofs_fast_symlink_iops = {
>  	.get_link = simple_get_link,
>  	.getattr = erofs_getattr,
> -#ifdef CONFIG_EROFS_FS_XATTR
>  	.listxattr = erofs_listxattr,
> -#endif
>  	.get_acl = erofs_get_acl,
>  };
>  
> diff --git a/fs/erofs/namei.c b/fs/erofs/namei.c
> index 3abbecbf73de..52f201e03c62 100644
> --- a/fs/erofs/namei.c
> +++ b/fs/erofs/namei.c
> @@ -244,9 +244,7 @@ static struct dentry *erofs_lookup(struct inode *dir,
>  const struct inode_operations erofs_dir_iops = {
>  	.lookup = erofs_lookup,
>  	.getattr = erofs_getattr,
> -#ifdef CONFIG_EROFS_FS_XATTR
>  	.listxattr = erofs_listxattr,
> -#endif
>  	.get_acl = erofs_get_acl,
>  };
>  
> diff --git a/fs/erofs/super.c b/fs/erofs/super.c
> index b514c67e5fc2..8e46d204a0c2 100644
> --- a/fs/erofs/super.c
> +++ b/fs/erofs/super.c
> @@ -408,10 +408,8 @@ static int erofs_fill_super(struct super_block *sb, void *data, int silent)
>  	sb->s_time_gran = 1;
>  
>  	sb->s_op = &erofs_sops;
> -
> -#ifdef CONFIG_EROFS_FS_XATTR
>  	sb->s_xattr = erofs_xattr_handlers;
> -#endif
> +
>  	/* set erofs default mount options */
>  	erofs_default_options(sbi);
>  
> diff --git a/fs/erofs/xattr.h b/fs/erofs/xattr.h
> index 50966f1c676e..e4e5093f012c 100644
> --- a/fs/erofs/xattr.h
> +++ b/fs/erofs/xattr.h
> @@ -76,11 +76,8 @@ static inline int erofs_getxattr(struct inode *inode, int index,
>  	return -EOPNOTSUPP;
>  }
>  
> -static inline ssize_t erofs_listxattr(struct dentry *dentry,
> -				      char *buffer, size_t buffer_size)
> -{
> -	return -EOPNOTSUPP;
> -}
> +#define erofs_listxattr (NULL)
> +#define erofs_xattr_handlers (NULL)
>  #endif	/* !CONFIG_EROFS_FS_XATTR */
>  
>  #ifdef CONFIG_EROFS_FS_POSIX_ACL
> -- 
> 2.20.1
> 
>