From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dheeraj Pandey Subject: writev to scsi disks Date: Wed, 20 Apr 2005 08:01:53 -0700 Message-ID: <363f92a8050420080112dec5db@mail.gmail.com> Reply-To: Dheeraj Pandey Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Return-path: Received: from rproxy.gmail.com ([64.233.170.205]:5424 "EHLO rproxy.gmail.com") by vger.kernel.org with ESMTP id S261641AbVDTPBy convert rfc822-to-8bit (ORCPT ); Wed, 20 Apr 2005 11:01:54 -0400 Received: by rproxy.gmail.com with SMTP id a41so126863rng for ; Wed, 20 Apr 2005 08:01:54 -0700 (PDT) Content-Disposition: inline Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org I was wondering if I did a simple writev to a SCSI disk, does it take the sg path to the device? I am guessing sg (REQ_SPECIAL) is only true for character devices (and ioctl's) and not block devices. These are my questions: - Is sg a common feature among SCSI disks these days? How do I know what disks support this feature (any capabilities published by the driver)? - How does one make writev work for SCSI disk (as a block device) in direct_io? - If I use SCSI disks as character device, can I simply use writev on the character device file, and will sg codepath be taken?