[PATCHv2] btrfs: list usage cleanup

[PATCHv2] btrfs: list usage cleanup

[zhong jiang]

Trival cleanup, list_move_tail will implement the same function that
list_del() + list_add_tail() will do. hence just replace them.

Signed-off-by: zhong jiang <zhongjiang@huawei.com>
---
 fs/btrfs/send.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 094cc144..30e7e12 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -2075,8 +2075,8 @@ static struct name_cache_entry *name_cache_search(struct send_ctx *sctx,
  */
 static void name_cache_used(struct send_ctx *sctx, struct name_cache_entry *nce)
 {
-	list_del(&nce->list);
-	list_add_tail(&nce->list, &sctx->name_cache_list);
+	/* delete from sctx->name_cache_list and add as its tail */
+	list_move_tail(&nce->list, &sctx->name_cache_list);
 }
 
 /*
-- 
1.7.12.4

Re: [PATCHv2] btrfs: list usage cleanup

[David Sterba]

On Thu, Oct 04, 2018 at 12:48:27PM +0800, zhong jiang wrote:
> Trival cleanup, list_move_tail will implement the same function that
> list_del() + list_add_tail() will do. hence just replace them.
> 
> Signed-off-by: zhong jiang <zhongjiang@huawei.com>
> ---
>  fs/btrfs/send.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
> index 094cc144..30e7e12 100644
> --- a/fs/btrfs/send.c
> +++ b/fs/btrfs/send.c
> @@ -2075,8 +2075,8 @@ static struct name_cache_entry *name_cache_search(struct send_ctx *sctx,
>   */
>  static void name_cache_used(struct send_ctx *sctx, struct name_cache_entry *nce)
>  {
> -	list_del(&nce->list);
> -	list_add_tail(&nce->list, &sctx->name_cache_list);
> +	/* delete from sctx->name_cache_list and add as its tail */
> +	list_move_tail(&nce->list, &sctx->name_cache_list);

The suggestion was to drop name_cache_used and replace it with
list_move_tail(...), the comment as you wrote it does not bring much
information as it merely repeats how list_move_tail is implemeted. A
useful comment explains something that's not obvious.