[PATCH] dm vdo indexer: Use swap() instead of open coding it

[PATCH] dm vdo indexer: Use swap() instead of open coding it

[Jiapeng Chong]

Swap is a function interface that provides exchange function. To avoid
code duplication, we can use swap function.

./drivers/md/dm-vdo/indexer/index.c:207:43-44: WARNING opportunity for swap().

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=9173
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
---
 drivers/md/dm-vdo/indexer/index.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/md/dm-vdo/indexer/index.c b/drivers/md/dm-vdo/indexer/index.c
index 1ba767144426..df4934846244 100644
--- a/drivers/md/dm-vdo/indexer/index.c
+++ b/drivers/md/dm-vdo/indexer/index.c
@@ -197,15 +197,12 @@ static int finish_previous_chapter(struct uds_index *index, u64 current_chapter_
 static int swap_open_chapter(struct index_zone *zone)
 {
 	int result;
-	struct open_chapter_zone *temporary_chapter;
 
 	result = finish_previous_chapter(zone->index, zone->newest_virtual_chapter);
 	if (result != UDS_SUCCESS)
 		return result;
 
-	temporary_chapter = zone->open_chapter;
-	zone->open_chapter = zone->writing_chapter;
-	zone->writing_chapter = temporary_chapter;
+	swap(zone->open_chapter, zone->writing_chapter);
 	return UDS_SUCCESS;
 }
 
-- 
2.20.1.7.g153144c

Re: [PATCH] dm vdo indexer: Use swap() instead of open coding it

[Markus Elfring]

> Swap is a function interface that provides exchange function. To avoid
> code duplication, we can use swap function.

Would a wording approach (like the following) be a bit nicer
for the second sentence?

   Use existing swap() function rather than duplicating its implementation.


How do you think about to apply the summary phrase “Use swap() in swap_open_chapter()”?


> ./drivers/md/dm-vdo/indexer/index.c:207:43-44: WARNING opportunity for swap().
>
> Reported-by: Abaci Robot <abaci@linux.alibaba.com>
> Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=9173

Would another indication be helpful for the involved analysis tool?
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/scripts/coccinelle/misc/swap.cocci?h=v6.9

Regards,
Markus

Re: [PATCH] dm vdo indexer: Use swap() instead of open coding it

[Matthew Sakai]

On 5/24/24 03:41, Jiapeng Chong wrote:
> Swap is a function interface that provides exchange function. To avoid
> code duplication, we can use swap function.
> 
> ./drivers/md/dm-vdo/indexer/index.c:207:43-44: WARNING opportunity for swap().
> 
> Reported-by: Abaci Robot <abaci@linux.alibaba.com>
> Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=9173
> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>

Reviewed-by: Matthew Sakai <msakai@redhat.com>

Mike, can you make sure this gets applied with the rest of the pending 
dm patches?

> ---
>   drivers/md/dm-vdo/indexer/index.c | 5 +----
>   1 file changed, 1 insertion(+), 4 deletions(-)
> 
> diff --git a/drivers/md/dm-vdo/indexer/index.c b/drivers/md/dm-vdo/indexer/index.c
> index 1ba767144426..df4934846244 100644
> --- a/drivers/md/dm-vdo/indexer/index.c
> +++ b/drivers/md/dm-vdo/indexer/index.c
> @@ -197,15 +197,12 @@ static int finish_previous_chapter(struct uds_index *index, u64 current_chapter_
>   static int swap_open_chapter(struct index_zone *zone)
>   {
>   	int result;
> -	struct open_chapter_zone *temporary_chapter;
>   
>   	result = finish_previous_chapter(zone->index, zone->newest_virtual_chapter);
>   	if (result != UDS_SUCCESS)
>   		return result;
>   
> -	temporary_chapter = zone->open_chapter;
> -	zone->open_chapter = zone->writing_chapter;
> -	zone->writing_chapter = temporary_chapter;
> +	swap(zone->open_chapter, zone->writing_chapter);
>   	return UDS_SUCCESS;
>   }
>