From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753634Ab3B1KcA (ORCPT ); Thu, 28 Feb 2013 05:32:00 -0500 Received: from smtp.eu.citrix.com ([46.33.159.39]:54669 "EHLO SMTP.EU.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752282Ab3B1K3g (ORCPT ); Thu, 28 Feb 2013 05:29:36 -0500 X-IronPort-AV: E=Sophos;i="4.84,754,1355097600"; d="scan'208";a="2012277" From: Roger Pau Monne To: , CC: Roger Pau Monne , Konrad Rzeszutek Wilk Subject: [PATCH RFC 02/12] xen-blkback: fix foreach_grant_safe to handle empty lists Date: Thu, 28 Feb 2013 11:28:45 +0100 Message-ID: <1362047335-26402-3-git-send-email-roger.pau@citrix.com> X-Mailer: git-send-email 1.7.7.5 (Apple Git-26) In-Reply-To: <1362047335-26402-1-git-send-email-roger.pau@citrix.com> References: <1362047335-26402-1-git-send-email-roger.pau@citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We may use foreach_grant_safe in the future with empty lists, so make sure we can handle them. Signed-off-by: Roger Pau Monné Cc: xen-devel@lists.xen.org Cc: Konrad Rzeszutek Wilk --- drivers/block/xen-blkback/blkback.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c index d40beb3..415a0c7 100644 --- a/drivers/block/xen-blkback/blkback.c +++ b/drivers/block/xen-blkback/blkback.c @@ -164,7 +164,7 @@ static void make_response(struct xen_blkif *blkif, u64 id, #define foreach_grant_safe(pos, n, rbtree, node) \ for ((pos) = container_of(rb_first((rbtree)), typeof(*(pos)), node), \ - (n) = rb_next(&(pos)->node); \ + (n) = (&(pos)->node != NULL) ? rb_next(&(pos)->node) : NULL; \ &(pos)->node != NULL; \ (pos) = container_of(n, typeof(*(pos)), node), \ (n) = (&(pos)->node != NULL) ? rb_next(&(pos)->node) : NULL) -- 1.7.7.5 (Apple Git-26)