Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759186AbaGXNzb (ORCPT ); Thu, 24 Jul 2014 09:55:31 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:42833 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758827AbaGXNz3 (ORCPT ); Thu, 24 Jul 2014 09:55:29 -0400 To: Sitsofe Wheeler Cc: Christoph Hellwig , "K. Y. Srinivasan" , gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, devel@linuxdriverproject.org, ohering@suse.com, apw@canonical.com, jasowang@redhat.com, jbottomley@parallels.com, linux-scsi@vger.kernel.org Subject: Re: [PATCH v2 3/3] [SCSI] Make LBP quirk skip lbpme checks tests From: "Martin K. Petersen" Organization: Oracle Corporation References: <20140724122223.GA31798@sucs.org> Date: Thu, 24 Jul 2014 09:54:24 -0400 In-Reply-To: <20140724122223.GA31798@sucs.org> (Sitsofe Wheeler's message of "Thu, 24 Jul 2014 13:22:23 +0100") Message-ID: User-Agent: Gnus/5.130012 (Ma Gnus v0.12) Emacs/24.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Source-IP: acsinet22.oracle.com [141.146.126.238] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >>>>> "Sitsofe" == Sitsofe Wheeler writes: Sitsofe> Fix incorrectly named variable. Some block devices (such as Sitsofe> Hyper-V passthrough SSDs) support logical block provisioning Sitsofe> (e.g. via UNMAP) but don't set lbpme thus disabling discard. The fix for an SSD that is known to support LBP but which does not claim support for it is to use: echo unmap > /sys/class/scsi_disk/foo/provisioning_mode I'm very much against short-circuiting the LBP logic in a passthrough driver because then we might end up in the exact situation we were trying to avoid with this patch series. Namely sending down commands unsupported by the target device. This kind of thing really needs to be a sysadmin decision and can be handled with a udev rule. -- Martin K. Petersen Oracle Linux Engineering -- 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/