From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754696AbZD0MH3 (ORCPT ); Mon, 27 Apr 2009 08:07:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753161AbZD0MHV (ORCPT ); Mon, 27 Apr 2009 08:07:21 -0400 Received: from cantor.suse.de ([195.135.220.2]:42147 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753117AbZD0MHU (ORCPT ); Mon, 27 Apr 2009 08:07:20 -0400 From: Nikanth Karthikesan Organization: suse.de To: Jens Axboe Subject: Re: [PATCH] Cleanup: Remove unused __REQ_NR_BITS from enum rq_flag_bits Date: Mon, 27 Apr 2009 17:35:01 +0530 User-Agent: KMail/1.11.1 (Linux/2.6.27.21-0.1-default; KDE/4.2.1; x86_64; ; ) Cc: linux-kernel@vger.kernel.org References: <200904271705.30550.knikanth@suse.de> <20090427114633.GA4593@kernel.dk> In-Reply-To: <20090427114633.GA4593@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200904271735.02007.knikanth@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday 27 April 2009 17:16:33 Jens Axboe wrote: > On Mon, Apr 27 2009, Nikanth Karthikesan wrote: > > The __REQ_NR_BITS was being used by blk_dump_rq_flags() long back, while > > printing the individual request flag bits as strings to limit to the used > > bits. But it does not use it now. Remove unused enum. > > > > Signed-off-by: Nikanth Karthikesan > > > > --- > > > > diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h > > index ba54c83..f41abbb 100644 > > --- a/include/linux/blkdev.h > > +++ b/include/linux/blkdev.h > > @@ -118,7 +118,6 @@ enum rq_flag_bits { > > __REQ_COPY_USER, /* contains copies of user pages */ > > __REQ_INTEGRITY, /* integrity metadata has been remapped */ > > __REQ_NOIDLE, /* Don't anticipate more IO after this one */ > > - __REQ_NR_BITS, /* stops here */ > > }; > > > > #define REQ_RW (1 << __REQ_RW) > > Lets turn it into something useful instead. It's meant to catch someone > adding too many flags, how about something like this: > > Untested ;-) > > diff --git a/block/blk-core.c b/block/blk-core.c > index d73eb76..e62ef94 100644 > --- a/block/blk-core.c > +++ b/block/blk-core.c > @@ -2159,6 +2159,8 @@ EXPORT_SYMBOL(kblockd_schedule_work); > > int __init blk_dev_init(void) > { > + BUILD_BUG_ON(__REQ_NR_BITS > 8 * sizeof(int)); > + > kblockd_workqueue = create_workqueue("kblockd"); > if (!kblockd_workqueue) > panic("Failed to create kblockd\n"); Good idea. How about this? Thanks Nikanth Catch trying to use more bits than request->cmd_flags has. Signed-off-by: Nikanth Karthikesan --- diff --git a/block/blk-core.c b/block/blk-core.c index 07ab754..218f745 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -2156,6 +2156,9 @@ EXPORT_SYMBOL(kblockd_schedule_work); int __init blk_dev_init(void) { + BUILD_BUG_ON(__REQ_NR_BITS > 8 * + sizeof(((struct request *)0)->cmd_flags)); + kblockd_workqueue = create_workqueue("kblockd"); if (!kblockd_workqueue) panic("Failed to create kblockd\n");