From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Elder Subject: [PATCH 3/5] rbd: do a few checks at build time Date: Tue, 28 Feb 2012 19:59:16 -0800 Message-ID: <4F4DA294.7050008@dreamhost.com> References: <4F4DA1EA.3080705@dreamhost.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail.hq.newdream.net ([66.33.206.127]:40137 "EHLO mail.hq.newdream.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752470Ab2B2D7R (ORCPT ); Tue, 28 Feb 2012 22:59:17 -0500 Received: from mail.hq.newdream.net (localhost [127.0.0.1]) by mail.hq.newdream.net (Postfix) with ESMTP id C674324318 for ; Tue, 28 Feb 2012 19:59:16 -0800 (PST) Received: from [192.168.107.136] (aon.hq.newdream.net [64.111.111.107]) by mail.hq.newdream.net (Postfix) with ESMTPSA id BAEE924314 for ; Tue, 28 Feb 2012 19:59:16 -0800 (PST) In-Reply-To: <4F4DA1EA.3080705@dreamhost.com> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: ceph-devel@vger.kernel.org This is a bit gratuitous, but there are a few things that can be verified at build time rather than run time, so do that. Signed-off-by: Alex Elder --- drivers/block/rbd.c | 15 ++++++++++++--- 1 files changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index d2157a7..0602ed9 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -53,7 +53,14 @@ #define RBD_SNAP_HEAD_NAME "-" +/* + * An RBD device name will be "rbd#", where the "rbd" comes from + * RBD_DRV_NAME above, and # is a unique integer identifier. + * MAX_INT_FORMAT_WIDTH is used in ensuring DEV_NAME_LEN is big + * enough to hold all possible device names. + */ #define DEV_NAME_LEN 32 +#define MAX_INT_FORMAT_WIDTH ((5 * sizeof (int)) / 2 + 1) #define RBD_NOTIFY_TIMEOUT_DEFAULT 10 @@ -2303,8 +2310,9 @@ static int rbd_add_parse_args(struct rbd_device *rbd_dev, rbd_dev->obj_len = len; - snprintf(rbd_dev->obj_md_name, sizeof(rbd_dev->obj_md_name), "%s%s", - rbd_dev->obj, RBD_SUFFIX); + BUILD_BUG_ON(RBD_MAX_MD_NAME_LEN + < RBD_MAX_OBJ_NAME_LEN + sizeof RBD_SUFFIX); + sprintf(rbd_dev->obj_md_name, "%s%s", rbd_dev->obj, RBD_SUFFIX); /* * The snapshot name is optional, but it's an error if it's @@ -2352,7 +2360,8 @@ static ssize_t rbd_add(struct bus_type *bus, rbd_id_get(rbd_dev); /* Fill in the device name, now that we have its id. */ - snprintf(rbd_dev->name, DEV_NAME_LEN, RBD_DRV_NAME "%d", rbd_dev->id); + BUILD_BUG_ON(DEV_NAME_LEN < sizeof RBD_DRV_NAME + MAX_INT_FORMAT_WIDTH); + sprintf(rbd_dev->name, "%s%d", RBD_DRV_NAME, rbd_dev->id); /* parse add command */ rc = rbd_add_parse_args(rbd_dev, buf, mon_addrs, count, -- 1.7.5.4