From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:57695 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751413AbeCOQIU (ORCPT ); Thu, 15 Mar 2018 12:08:20 -0400 Subject: Re: [PATCH 08/16] bcache: Fix a compiler warning in bcache_device_init() To: Bart Van Assche , Michael Lyle , Kent Overstreet Cc: linux-block@vger.kernel.org, Christoph Hellwig , linux-bcache References: <20180315150814.9412-1-bart.vanassche@wdc.com> <20180315150814.9412-9-bart.vanassche@wdc.com> From: Coly Li Message-ID: Date: Fri, 16 Mar 2018 00:07:12 +0800 MIME-Version: 1.0 In-Reply-To: <20180315150814.9412-9-bart.vanassche@wdc.com> Content-Type: text/plain; charset=utf-8 Sender: linux-block-owner@vger.kernel.org List-Id: linux-block@vger.kernel.org On 15/03/2018 11:08 PM, Bart Van Assche wrote: > Avoid that building with W=1 triggers the following compiler warning: > > drivers/md/bcache/super.c:776:20: warning: comparison is always false due to limited range of data type [-Wtype-limits] > d->nr_stripes > SIZE_MAX / sizeof(atomic_t)) { > ^ > > Signed-off-by: Bart Van Assche Reviewed-by: Coly Li Thanks. Coly Li > --- > drivers/md/bcache/super.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c > index e8dfa804bd98..87c1f853bbb3 100644 > --- a/drivers/md/bcache/super.c > +++ b/drivers/md/bcache/super.c > @@ -769,6 +769,8 @@ static int bcache_device_init(struct bcache_device *d, unsigned block_size, > sector_t sectors) > { > struct request_queue *q; > + const size_t max_stripes = min_t(size_t, INT_MAX, > + SIZE_MAX / sizeof(atomic_t)); > size_t n; > int idx; > > @@ -777,9 +779,7 @@ static int bcache_device_init(struct bcache_device *d, unsigned block_size, > > d->nr_stripes = DIV_ROUND_UP_ULL(sectors, d->stripe_size); > > - if (!d->nr_stripes || > - d->nr_stripes > INT_MAX || > - d->nr_stripes > SIZE_MAX / sizeof(atomic_t)) { > + if (!d->nr_stripes || d->nr_stripes > max_stripes) { > pr_err("nr_stripes too large or invalid: %u (start sector beyond end of disk?)", > (unsigned)d->nr_stripes); > return -ENOMEM; >