[PATCH v8 09/20] erofs: add mode checking helper

[Gao Xiang]

On Wed, Apr 06, 2022 at 03:56:01PM +0800, Jeffle Xu wrote:
> Until then erofs is exactly blockdev based filesystem.
> 
> A new fscache-based mode is going to be introduced for erofs to support
> scenarios where on-demand read semantics is needed, e.g. container
> image distribution. In this case, erofs could be mounted from data blobs
> through fscache.
> 
> Add a helper checking which mode erofs works in.
> 
> Signed-off-by: Jeffle Xu <jefflexu at linux.alibaba.com>

Reviewed-by: Gao Xiang <hsiangkao at linux.alibaba.com>

Thanks,
Gao Xiang

> ---
>  fs/erofs/internal.h | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
> index fe9564e5091e..05a97533b1e9 100644
> --- a/fs/erofs/internal.h
> +++ b/fs/erofs/internal.h
> @@ -161,6 +161,11 @@ struct erofs_sb_info {
>  #define set_opt(opt, option)	((opt)->mount_opt |= EROFS_MOUNT_##option)
>  #define test_opt(opt, option)	((opt)->mount_opt & EROFS_MOUNT_##option)
>  
> +static inline bool erofs_is_fscache_mode(struct super_block *sb)
> +{
> +	return IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) && !sb->s_bdev;
> +}
> +
>  enum {
>  	EROFS_ZIP_CACHE_DISABLED,
>  	EROFS_ZIP_CACHE_READAHEAD,
> -- 
> 2.27.0