Re: [PATCH] RDMA/rxe: Correct error handling in routines allocating xarray entries

[Bob Pearson <rpearsonhpe@gmail.com>]

On 8/1/22 02:38, William Kucharski wrote:
> The current code will report an error if xa_alloc_cyclic() returns
> non-zero, but it will return 1 if it wrapped indices before successfully
> allocating an entry.
> 
> An error should only be reported if the call actually failed (denoted by
> a return value < 0.)
> 
> Fixes: 3225717f6dfa2 ("RDMA/rxe: Replace red-black trees by xarrays")
> Signed-off-by: William Kucharski <william.kucharski@oracle.com>
> ---
>  drivers/infiniband/sw/rxe/rxe_pool.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/infiniband/sw/rxe/rxe_pool.c b/drivers/infiniband/sw/rxe/rxe_pool.c
> index 19b14826385b..e9f3bbd8d605 100644
> --- a/drivers/infiniband/sw/rxe/rxe_pool.c
> +++ b/drivers/infiniband/sw/rxe/rxe_pool.c
> @@ -139,7 +139,7 @@ void *rxe_alloc(struct rxe_pool *pool)
>  
>  	err = xa_alloc_cyclic(&pool->xa, &elem->index, elem, pool->limit,
>  			      &pool->next, GFP_KERNEL);
> -	if (err)
> +	if (err < 0)
>  		goto err_free;
>  
>  	return obj;
> @@ -167,7 +167,7 @@ int __rxe_add_to_pool(struct rxe_pool *pool, struct rxe_pool_elem *elem)
>  
>  	err = xa_alloc_cyclic(&pool->xa, &elem->index, elem, pool->limit,
>  			      &pool->next, GFP_KERNEL);
> -	if (err)
> +	if (err < 0)
>  		goto err_cnt;
>  
>  	return 0;

We fixed this a while back but not sure what happened. In any case this is absolutely correct.
You can add

Reviewed-by: Bob Pearson <rpearsonhpe@gmail.com>

Bob