On 2018/11/28 上午3:53, David Sterba wrote:
> We can use simple enum for values that are not part of on-disk format:
> extent buffer flags;
> 
> Signed-off-by: David Sterba <dsterba@suse.com>

Reviewed-by: Qu Wenruo <wqu@suse.com>

Thanks,
Qu

> ---
>  fs/btrfs/extent_io.h | 28 ++++++++++++++++------------
>  1 file changed, 16 insertions(+), 12 deletions(-)
> 
> diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
> index a1d3ea5a0d32..fd42492e62e5 100644
> --- a/fs/btrfs/extent_io.h
> +++ b/fs/btrfs/extent_io.h
> @@ -37,18 +37,22 @@
>  #define EXTENT_BIO_COMPRESSED 1
>  #define EXTENT_BIO_FLAG_SHIFT 16
>  
> -/* these are bit numbers for test/set bit */
> -#define EXTENT_BUFFER_UPTODATE 0
> -#define EXTENT_BUFFER_DIRTY 2
> -#define EXTENT_BUFFER_CORRUPT 3
> -#define EXTENT_BUFFER_READAHEAD 4	/* this got triggered by readahead */
> -#define EXTENT_BUFFER_TREE_REF 5
> -#define EXTENT_BUFFER_STALE 6
> -#define EXTENT_BUFFER_WRITEBACK 7
> -#define EXTENT_BUFFER_READ_ERR 8        /* read IO error */
> -#define EXTENT_BUFFER_UNMAPPED 9
> -#define EXTENT_BUFFER_IN_TREE 10
> -#define EXTENT_BUFFER_WRITE_ERR 11    /* write IO error */
> +enum {
> +	EXTENT_BUFFER_UPTODATE,
> +	EXTENT_BUFFER_DIRTY,
> +	EXTENT_BUFFER_CORRUPT,
> +	/* this got triggered by readahead */
> +	EXTENT_BUFFER_READAHEAD,
> +	EXTENT_BUFFER_TREE_REF,
> +	EXTENT_BUFFER_STALE,
> +	EXTENT_BUFFER_WRITEBACK,
> +	/* read IO error */
> +	EXTENT_BUFFER_READ_ERR,
> +	EXTENT_BUFFER_UNMAPPED,
> +	EXTENT_BUFFER_IN_TREE,
> +	/* write IO error */
> +	EXTENT_BUFFER_WRITE_ERR,
> +};
>  
>  /* these are flags for __process_pages_contig */
>  #define PAGE_UNLOCK		(1 << 0)
>