Re: [PATCH] blk: remove NULL check before freeing functions
From: Jeff Moyer
Date: Mon May 23 2016 - 11:20:30 EST
Mike Danese <mikedanese@xxxxxxxxxx> writes:
> Coccinelle complains:
>
> WARNING: NULL check before freeing functions like kfree, debugfs_remove,
> debugfs_remove_recursive or usb_free_urb is not needed. Maybe consider
> reorganizing relevant code to avoid passing NULL values.
>
> Signed-off-by: Mike Danese <mikedanese@xxxxxxxxxx>
Acked-by: Jeff Moyer <jmoyer@xxxxxxxxxx>
> ---
> block/bio-integrity.c | 7 ++-----
> block/bio.c | 7 ++-----
> block/blk-core.c | 3 +--
> block/elevator.c | 3 +--
> 4 files changed, 6 insertions(+), 14 deletions(-)
>
> diff --git a/block/bio-integrity.c b/block/bio-integrity.c
> index 711e4d8d..27bf4e7 100644
> --- a/block/bio-integrity.c
> +++ b/block/bio-integrity.c
> @@ -499,11 +499,8 @@ EXPORT_SYMBOL(bioset_integrity_create);
>
> void bioset_integrity_free(struct bio_set *bs)
> {
> - if (bs->bio_integrity_pool)
> - mempool_destroy(bs->bio_integrity_pool);
> -
> - if (bs->bvec_integrity_pool)
> - mempool_destroy(bs->bvec_integrity_pool);
> + mempool_destroy(bs->bio_integrity_pool);
> + mempool_destroy(bs->bvec_integrity_pool);
> }
> EXPORT_SYMBOL(bioset_integrity_free);
>
> diff --git a/block/bio.c b/block/bio.c
> index 0e4aa42..e1e1773 100644
> --- a/block/bio.c
> +++ b/block/bio.c
> @@ -1844,11 +1844,8 @@ void bioset_free(struct bio_set *bs)
> if (bs->rescue_workqueue)
> destroy_workqueue(bs->rescue_workqueue);
>
> - if (bs->bio_pool)
> - mempool_destroy(bs->bio_pool);
> -
> - if (bs->bvec_pool)
> - mempool_destroy(bs->bvec_pool);
> + mempool_destroy(bs->bio_pool);
> + mempool_destroy(bs->bvec_pool);
>
> bioset_integrity_free(bs);
> bio_put_slab(bs);
> diff --git a/block/blk-core.c b/block/blk-core.c
> index 2475b1c7..916e7c3 100644
> --- a/block/blk-core.c
> +++ b/block/blk-core.c
> @@ -636,8 +636,7 @@ int blk_init_rl(struct request_list *rl, struct request_queue *q,
>
> void blk_exit_rl(struct request_list *rl)
> {
> - if (rl->rq_pool)
> - mempool_destroy(rl->rq_pool);
> + mempool_destroy(rl->rq_pool);
> }
>
> struct request_queue *blk_alloc_queue(gfp_t gfp_mask)
> diff --git a/block/elevator.c b/block/elevator.c
> index c3555c9..5dc91ca 100644
> --- a/block/elevator.c
> +++ b/block/elevator.c
> @@ -847,8 +847,7 @@ int elv_register(struct elevator_type *e)
> spin_lock(&elv_list_lock);
> if (elevator_find(e->elevator_name)) {
> spin_unlock(&elv_list_lock);
> - if (e->icq_cache)
> - kmem_cache_destroy(e->icq_cache);
> + kmem_cache_destroy(e->icq_cache);
> return -EBUSY;
> }
> list_add_tail(&e->list, &elv_list);