Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756185Ab0KWTBG (ORCPT ); Tue, 23 Nov 2010 14:01:06 -0500 Received: from e4.ny.us.ibm.com ([32.97.182.144]:33602 "EHLO e4.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754613Ab0KWTBD (ORCPT ); Tue, 23 Nov 2010 14:01:03 -0500 Date: Tue, 23 Nov 2010 11:01:03 -0800 From: "Darrick J. Wong" To: Neil Brown Cc: linux-raid@vger.kernel.org, linux-kernel Subject: [PATCH v2] md: Call blk_queue_flush() to establish flush/fua support Message-ID: <20101123190103.GW14383@tux1.beaverton.ibm.com> Reply-To: djwong@us.ibm.com References: <20101122232208.GU14383@tux1.beaverton.ibm.com> <20101123105000.331b40f8@notabene.brown> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20101123105000.331b40f8@notabene.brown> User-Agent: Mutt/1.5.17+20080114 (2008-01-14) X-Content-Scanned: Fidelis XPS MAILER Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1417 Lines: 35 Here's a shorter version that sets up flush/fua unconditionally. --- Before 2.6.37, the md layer had a mechanism for catching I/Os with the barrier flag set, and translating the barrier into barriers for all the underlying devices. With 2.6.37, I/O barriers have become plain old flushes, and the md code was updated to reflect this. However, one piece was left out -- the md layer does not tell the block layer that it supports flushes or FUA access at all, which results in md silently dropping flush requests. Since the support already seems there, just add this one piece of bookkeeping. Signed-off-by: Darrick J. Wong --- drivers/md/md.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 324a366..43243a4 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -4338,6 +4338,8 @@ static int md_alloc(dev_t dev, char *name) if (mddev->kobj.sd && sysfs_create_group(&mddev->kobj, &md_bitmap_group)) printk(KERN_DEBUG "pointless warning\n"); + + blk_queue_flush(mddev->queue, REQ_FLUSH | REQ_FUA); abort: mutex_unlock(&disks_mutex); if (!error && mddev->kobj.sd) { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/