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Message-ID: <13232d91-d50e-0936-7e46-680721119262@gmail.com>
Date:   Mon, 1 Aug 2022 14:12:42 -0500
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Subject: Re: [PATCH] RDMA/rxe: Correct error handling in routines allocating
 xarray entries
Content-Language: en-US
To:     William Kucharski <william.kucharski@oracle.com>,
        Zhu Yanjun <zyjzyj2000@gmail.com>,
        Jason Gunthorpe <jgg@ziepe.ca>,
        Leon Romanovsky <leon@kernel.org>, linux-rdma@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20220801073850.841628-1-william.kucharski@oracle.com>
From:   Bob Pearson <rpearsonhpe@gmail.com>
In-Reply-To: <20220801073850.841628-1-william.kucharski@oracle.com>
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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