Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261541AbVEPL1h (ORCPT ); Mon, 16 May 2005 07:27:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261550AbVEPL1h (ORCPT ); Mon, 16 May 2005 07:27:37 -0400 Received: from verein.lst.de ([213.95.11.210]:18305 "EHLO mail.lst.de") by vger.kernel.org with ESMTP id S261541AbVEPL1X (ORCPT ); Mon, 16 May 2005 07:27:23 -0400 Date: Mon, 16 May 2005 13:27:22 +0200 From: Christoph Hellwig To: axboe@suse.de Cc: linux-kernel@vger.kernel.org Subject: finding out whether a device supports ordered writes ahead of time Message-ID: <20050516112722.GA9736@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.3.28i X-Spam-Score: -4.901 () BAYES_00 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 742 Lines: 12 Currently ext3 and reiserfs submit bios with BIO_RW_BARRIER and when the device doesn't support it it returns EOPNOTUPP. This scheme doesn't work at all for XFS because our I/O submission path keeps around far too much state (XFS supports multi-page metadata buffers). From looking at the code it seems that we can assume such a submission will just work if q->ordered is not QUEUE_ORDERED_NONE. Is that a valid assumption? and if yes should we look directly at the queue or provide an assecor? - 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/