2018-10-04 05:01:55

by zhong jiang

Subject: [PATCHv2] btrfs: list usage cleanup

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 <[email protected]>
---
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

2018-10-04 10:03:06

by David Sterba

Subject: Re: [PATCHv2] btrfs: list usage cleanup

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 <[email protected]>
> ---
> 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.