Return-Path: linux-nfs-owner@vger.kernel.org Received: from rcsinet15.oracle.com ([148.87.113.117]:42390 "EHLO rcsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753060Ab2AaCXB (ORCPT ); Mon, 30 Jan 2012 21:23:01 -0500 To: Andreas Dilger Cc: "Martin K. Petersen" , Bernd Schubert , Chuck Lever , "lsf-pc\@lists.linux-foundation.org" , linux-fsdevel , Linux NFS Mailing List , "linux-scsi\@vger.kernel.org" , Sven Breuner Subject: Re: [LSF/MM TOPIC] end-to-end data and metadata corruption detection From: "Martin K. Petersen" References: <38C050B3-2AAD-4767-9A25-02C33627E427@oracle.com> <4F2147BA.6030607@itwm.fraunhofer.de> Date: Mon, 30 Jan 2012 21:22:49 -0500 In-Reply-To: (Andreas Dilger's message of "Thu, 26 Jan 2012 09:34:44 -0700") Message-ID: MIME-Version: 1.0 Content-Type: text/plain Sender: linux-nfs-owner@vger.kernel.org List-ID: >>>>> "Andreas" == Andreas Dilger writes: Andreas> Is there a description of sys_dio() somewhere? This was the original draft: http://www.spinics.net/lists/linux-mm/msg14512.html Andreas> In particular, I'm interested to know whether it allows full Andreas> scatter-gather IO submission, unlike pwrite() which only allows Andreas> multiple input buffers, and not multiple file offsets. Each request descriptor contains buffer, target file, and offset. So it's a single entry per descriptor. But many descriptors can be submitted (and reaped) in a single syscall. So you don't have the single file offset limitation of pwritev(). -- Martin K. Petersen Oracle Linux Engineering