[Drbd-dev] [PATCH 21/39] drbd: drop null test before destroy functions

[Drbd-dev] [PATCH 21/39] drbd: drop null test before destroy functions

[Julia Lawall]

Remove unneeded NULL test.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@ expression x; @@
-if (x != NULL)
  \(kmem_cache_destroy\|mempool_destroy\|dma_pool_destroy\)(x);
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

---
 drivers/block/drbd/drbd_main.c |   21 +++++++--------------
 1 file changed, 7 insertions(+), 14 deletions(-)

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 74d97f4..d98eeec 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -2034,20 +2034,13 @@ static void drbd_destroy_mempools(void)
 
 	if (drbd_md_io_bio_set)
 		bioset_free(drbd_md_io_bio_set);
-	if (drbd_md_io_page_pool)
-		mempool_destroy(drbd_md_io_page_pool);
-	if (drbd_ee_mempool)
-		mempool_destroy(drbd_ee_mempool);
-	if (drbd_request_mempool)
-		mempool_destroy(drbd_request_mempool);
-	if (drbd_ee_cache)
-		kmem_cache_destroy(drbd_ee_cache);
-	if (drbd_request_cache)
-		kmem_cache_destroy(drbd_request_cache);
-	if (drbd_bm_ext_cache)
-		kmem_cache_destroy(drbd_bm_ext_cache);
-	if (drbd_al_ext_cache)
-		kmem_cache_destroy(drbd_al_ext_cache);
+	mempool_destroy(drbd_md_io_page_pool);
+	mempool_destroy(drbd_ee_mempool);
+	mempool_destroy(drbd_request_mempool);
+	kmem_cache_destroy(drbd_ee_cache);
+	kmem_cache_destroy(drbd_request_cache);
+	kmem_cache_destroy(drbd_bm_ext_cache);
+	kmem_cache_destroy(drbd_al_ext_cache);
 
 	drbd_md_io_bio_set   = NULL;
 	drbd_md_io_page_pool = NULL;

Re: [Drbd-dev] [PATCH 21/39] drbd: drop null test before destroy functions

[Lars Ellenberg]

On Sun, Sep 13, 2015 at 02:15:14PM +0200, Julia Lawall wrote:
> Remove unneeded NULL test.
> 
> The semantic patch that makes this change is as follows:
> (http://coccinelle.lip6.fr/)
> 
> // <smpl>
> @@ expression x; @@
> -if (x != NULL)
>   \(kmem_cache_destroy\|mempool_destroy\|dma_pool_destroy\)(x);
> // </smpl>

Thanks.

Just a note for our external module repo, which is supposed to be
compatible to "all" kernel versions: don't apply,
requires upstream commits
44d7175 mm/dmapool: allow NULL `pool' pointer in dma_pool_destroy()
4e3ca3e mm/mempool: allow NULL `pool' pointer in mempool_destroy()
3942d29 mm/slab_common: allow NULL cache pointer in kmem_cache_destroy()
(v4.3-rc1)


	Lars Ellenberg