Re: [PATCH] rbd: use GFP_NOIO in rbd_obj_request_create()

[Alex Elder <elder@ieee.org>]

On 06/30/2015 02:19 PM, Ilya Dryomov wrote:
> rbd_obj_request_create() is called on the main I/O path, so we need to
> use GFP_NOIO to make sure allocation doesn't blow back on us.  Not all
> callers need this, but I'm still hardcoding the flag inside rather than
> making it a parameter because a) this is going to stable, and b) those
> callers shouldn't really use rbd_obj_request_create() and will be fixed
> in the future.
> 
> More memory allocation fixes will follow.

This looks OK to me.  It's conservative; you can add a GFP parameter
in the future.

Reviewed-by: Alex Elder <elder@linaro.org>

> 
> Cc: stable@vger.kernel.org # 3.10+
> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
> ---
>  drivers/block/rbd.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
> index b316ee48a30b..d94529d5c8e9 100644
> --- a/drivers/block/rbd.c
> +++ b/drivers/block/rbd.c
> @@ -2022,11 +2022,11 @@ static struct rbd_obj_request *rbd_obj_request_create(const char *object_name,
>  	rbd_assert(obj_request_type_valid(type));
>  
>  	size = strlen(object_name) + 1;
> -	name = kmalloc(size, GFP_KERNEL);
> +	name = kmalloc(size, GFP_NOIO);
>  	if (!name)
>  		return NULL;
>  
> -	obj_request = kmem_cache_zalloc(rbd_obj_request_cache, GFP_KERNEL);
> +	obj_request = kmem_cache_zalloc(rbd_obj_request_cache, GFP_NOIO);
>  	if (!obj_request) {
>  		kfree(name);
>  		return NULL;
>