[PATCH 1/2] zram: fix memory freeing in zram_meta_alloc

[PATCH 1/2] zram: fix memory freeing in zram_meta_alloc

[Geliang Tang]

When meta->table is NULL, there is no need to vfree it.

Signed-off-by: Geliang Tang <geliangtang@163.com>
---
 drivers/block/zram/zram_drv.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 81a557c..197a7ad 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -511,7 +511,7 @@ static struct zram_meta *zram_meta_alloc(char *pool_name, u64 disksize)
 	meta->table = vzalloc(num_pages * sizeof(*meta->table));
 	if (!meta->table) {
 		pr_err("Error allocating zram address table\n");
-		goto out_error;
+		goto out_free;
 	}
 
 	meta->mem_pool = zs_create_pool(pool_name, GFP_NOIO | __GFP_HIGHMEM);
@@ -524,6 +524,7 @@ static struct zram_meta *zram_meta_alloc(char *pool_name, u64 disksize)
 
 out_error:
 	vfree(meta->table);
+out_free:
 	kfree(meta);
 	return NULL;
 }
-- 
2.5.0

[PATCH 2/2] zram: fix memory freeing in zram_bvec_read

[Geliang Tang]

When user_mem is NULL, there is no need to kunmap_atomic it.

Signed-off-by: Geliang Tang <geliangtang@163.com>
---
 drivers/block/zram/zram_drv.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 197a7ad..da7b348 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -625,7 +625,7 @@ static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec,
 	if (!uncmem) {
 		pr_err("Unable to allocate temp memory\n");
 		ret = -ENOMEM;
-		goto out_cleanup;
+		goto out_free;
 	}
 
 	ret = zram_decompress_page(zram, uncmem, index);
@@ -641,6 +641,7 @@ static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec,
 	ret = 0;
 out_cleanup:
 	kunmap_atomic(user_mem);
+out_free:
 	if (is_partial_io(bvec))
 		kfree(uncmem);
 	return ret;
-- 
2.5.0

Re: [PATCH 2/2] zram: fix memory freeing in zram_bvec_read

[Sergey Senozhatsky]

On (11/08/15 23:32), Geliang Tang wrote:
> When user_mem is NULL, there is no need to kunmap_atomic it.

Hi,

kunmap_atomic() should be called.

	-ss

> Signed-off-by: Geliang Tang <geliangtang@163.com>
> ---
>  drivers/block/zram/zram_drv.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
> index 197a7ad..da7b348 100644
> --- a/drivers/block/zram/zram_drv.c
> +++ b/drivers/block/zram/zram_drv.c
> @@ -625,7 +625,7 @@ static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec,
>  	if (!uncmem) {
>  		pr_err("Unable to allocate temp memory\n");
>  		ret = -ENOMEM;
> -		goto out_cleanup;
> +		goto out_free;
>  	}
>  
>  	ret = zram_decompress_page(zram, uncmem, index);
> @@ -641,6 +641,7 @@ static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec,
>  	ret = 0;
>  out_cleanup:
>  	kunmap_atomic(user_mem);
> +out_free:
>  	if (is_partial_io(bvec))
>  		kfree(uncmem);
>  	return ret;
> -- 
> 2.5.0

Re: [PATCH 1/2] zram: fix memory freeing in zram_meta_alloc

[Sergey Senozhatsky]

On (11/08/15 23:32), Geliang Tang wrote:
> When meta->table is NULL, there is no need to vfree it.
> 

Hi,

So what's the benefit? It's ok to pass a NULL pointer to vfree(). Why
would we add another label? To avoid a valid call on error path?

	-ss

> Signed-off-by: Geliang Tang <geliangtang@163.com>
> ---
>  drivers/block/zram/zram_drv.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
> index 81a557c..197a7ad 100644
> --- a/drivers/block/zram/zram_drv.c
> +++ b/drivers/block/zram/zram_drv.c
> @@ -511,7 +511,7 @@ static struct zram_meta *zram_meta_alloc(char *pool_name, u64 disksize)
>  	meta->table = vzalloc(num_pages * sizeof(*meta->table));
>  	if (!meta->table) {
>  		pr_err("Error allocating zram address table\n");
> -		goto out_error;
> +		goto out_free;
>  	}
>  
>  	meta->mem_pool = zs_create_pool(pool_name, GFP_NOIO | __GFP_HIGHMEM);
> @@ -524,6 +524,7 @@ static struct zram_meta *zram_meta_alloc(char *pool_name, u64 disksize)
>  
>  out_error:
>  	vfree(meta->table);
> +out_free:
>  	kfree(meta);
>  	return NULL;
>  }
> -- 
> 2.5.0
> 
>