From: Ed Cashin <ecashin@coraid.com>
To: Roel Kluin <roel.kluin@gmail.com>
Cc: lkml <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] aoe: error printed 1 too early
Date: Wed, 25 Feb 2009 12:09:02 -0500 [thread overview]
Message-ID: <20090225170901.GA26634@coraid.com> (raw)
In-Reply-To: <49A549EE.7020202@gmail.com>
On Wed, Feb 25, 2009 at 02:38:54PM +0100, Roel Kluin wrote:
> with while (i-- > 0); i reaches -1 after the loop, so the test below is printed
> one too early: 0 still means success.
>
> Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
> ---
> diff --git a/drivers/block/aoe/aoedev.c b/drivers/block/aoe/aoedev.c
> index cc25057..eeea477 100644
> --- a/drivers/block/aoe/aoedev.c
> +++ b/drivers/block/aoe/aoedev.c
> @@ -173,7 +173,7 @@ skbfree(struct sk_buff *skb)
> return;
> while (atomic_read(&skb_shinfo(skb)->dataref) != 1 && i-- > 0)
> msleep(Sms);
> - if (i <= 0) {
> + if (i < 0) {
> printk(KERN_ERR
> "aoe: %s holds ref: %s\n",
> skb->dev ? skb->dev->name : "netif",
>
You are talking about the case where, when entering the loop on the
"last chance" iteration, the states are,
atomic_read(&skb_shinfo(skb)->dataref == 1
i == 0
... in which case, the skb can and should be used but is not used
because after the value of i is tested it becomes -1.
Right?
Sounds like a good catch. Did you find it because you saw the "cannot
free skb" message?
--
Ed Cashin <ecashin@coraid.com>
next prev parent reply other threads:[~2009-02-25 17:09 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-25 13:38 [PATCH] aoe: error printed 1 too early Roel Kluin
2009-02-25 17:09 ` Ed Cashin [this message]
2009-02-25 22:01 ` David Miller
2009-02-25 22:19 ` Ed Cashin
2009-02-25 22:29 ` roel kluin
2009-03-04 8:08 ` David Miller
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