linux-kernel - Re: [PATCH] scsi: cxgbi: remove redundant __kfree

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Date:   Tue, 09 Apr 2019 16:33:59 +0200
From:   walter harms <wharms@....de>
To:     Colin King <colin.king@...onical.com>
CC:     Karen Xie <kxie@...lsio.com>,
        "James E . J . Bottomley" <jejb@...ux.ibm.com>,
        "Martin K . Petersen" <martin.petersen@...cle.com>,
        linux-scsi@...r.kernel.org, kernel-janitors@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] scsi: cxgbi: remove redundant __kfree_skb call on skb



Am 09.04.2019 15:38, schrieb Colin King:
> From: Colin Ian King <colin.king@...onical.com>
> 
> The error return path via label rel_resource checks for a non-null
> skb before free'ing it.  However, skb is always null at this exit
> path, so the null check and the free are redundant and can be removed.
> Removing this allows the original goto's to rel_resource to be cleaned
> up; the first can be replaced by a return of -EINVAL, the second can
> be replaced by a more appropriate -ENOMEM return since allow_wr has
> failed go allocate some memory.
> 
> Addresses-Coverity: ("Logically Dead Code")
> Signed-off-by: Colin Ian King <colin.king@...onical.com>
> ---
>  drivers/scsi/cxgbi/cxgb3i/cxgb3i.c | 9 ++-------
>  1 file changed, 2 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/scsi/cxgbi/cxgb3i/cxgb3i.c b/drivers/scsi/cxgbi/cxgb3i/cxgb3i.c
> index 75e1273a44b3..5a4387f437d5 100644
> --- a/drivers/scsi/cxgbi/cxgb3i/cxgb3i.c
> +++ b/drivers/scsi/cxgbi/cxgb3i/cxgb3i.c
> @@ -979,14 +979,14 @@ static int init_act_open(struct cxgbi_sock *csk)
>  	csk->atid = cxgb3_alloc_atid(t3dev, &t3_client, csk);
>  	if (csk->atid < 0) {
>  		pr_err("NO atid available.\n");
> -		goto rel_resource;
> +		return -EINVAL;
>  	}
>  	cxgbi_sock_set_flag(csk, CTPF_HAS_ATID);
>  	cxgbi_sock_get(csk);
>  
>  	skb = alloc_wr(sizeof(struct cpl_act_open_req), 0, GFP_KERNEL);
>  	if (!skb)
> -		goto rel_resource;
> +		return -ENOMEM;

I would expect a cxgb3_free_atid(csk->atid) here. Did i miss something ?

re,
 wh


>  	skb->sk = (struct sock *)csk;
>  	set_arp_failure_handler(skb, act_open_arp_failure);
>  	csk->snd_win = cxgb3i_snd_win;
> @@ -1007,11 +1007,6 @@ static int init_act_open(struct cxgbi_sock *csk)
>  	cxgbi_sock_set_state(csk, CTP_ACTIVE_OPEN);
>  	send_act_open_req(csk, skb, csk->l2t);
>  	return 0;
> -
> -rel_resource:
> -	if (skb)
> -		__kfree_skb(skb);
> -	return -EINVAL;
>  }
>  
>  cxgb3_cpl_handler_func cxgb3i_cpl_handlers[NUM_CPL_CMDS] = {