Re: [PATCHv3 2/2] btrfs: change remove_extent_mapping to be void function

From: Nikolay Borisov
Date: Thu Sep 13 2018 - 01:53:00 EST




On 13.09.2018 06:01, zhong jiang wrote:
> remove_extent_mapping use the variable "ret" for return value,
> but it is not modified after initialzation. Further, I find that
> any of the callers do not handle the return value, so it is safe
> to drop the unneeded "ret" and make it to be void function.
>
> Signed-off-by: zhong jiang <zhongjiang@xxxxxxxxxx>

Reviewed-by: Nikolay Borisov <nborisov@xxxxxxxx

> ---
> fs/btrfs/extent_map.c | 5 +----
> fs/btrfs/extent_map.h | 2 +-
> 2 files changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
> index c4e2347..81b6a08 100644
> --- a/fs/btrfs/extent_map.c
> +++ b/fs/btrfs/extent_map.c
> @@ -428,16 +428,13 @@ struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
> * Removes @em from @tree. No reference counts are dropped, and no checks
> * are done to see if the range is in use
> */
> -int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em)
> +void remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em)
> {
> - int ret = 0;
> -
> WARN_ON(test_bit(EXTENT_FLAG_PINNED, &em->flags));
> rb_erase_cached(&em->rb_node, &tree->map);
> if (!test_bit(EXTENT_FLAG_LOGGING, &em->flags))
> list_del_init(&em->list);
> RB_CLEAR_NODE(&em->rb_node);
> - return ret;
> }
>
> void replace_extent_mapping(struct extent_map_tree *tree,
> diff --git a/fs/btrfs/extent_map.h b/fs/btrfs/extent_map.h
> index df4e1a5..8798745 100644
> --- a/fs/btrfs/extent_map.h
> +++ b/fs/btrfs/extent_map.h
> @@ -78,7 +78,7 @@ struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
> u64 start, u64 len);
> int add_extent_mapping(struct extent_map_tree *tree,
> struct extent_map *em, int modified);
> -int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
> +void remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
> void replace_extent_mapping(struct extent_map_tree *tree,
> struct extent_map *cur,
> struct extent_map *new,
>