From patchwork Thu Dec 4 02:44:46 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Martin K. Petersen" X-Patchwork-Id: 417608 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id B5EB21400E2 for ; Thu, 4 Dec 2014 13:44:53 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752054AbaLDCow (ORCPT ); Wed, 3 Dec 2014 21:44:52 -0500 Received: from aserp1040.oracle.com ([141.146.126.69]:47934 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751334AbaLDCow (ORCPT ); Wed, 3 Dec 2014 21:44:52 -0500 Received: from ucsinet22.oracle.com (ucsinet22.oracle.com [156.151.31.94]) by aserp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id sB42in6H010274 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 4 Dec 2014 02:44:50 GMT Received: from userz7022.oracle.com (userz7022.oracle.com [156.151.31.86]) by ucsinet22.oracle.com (8.14.5+Sun/8.14.5) with ESMTP id sB42imMd005846 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 4 Dec 2014 02:44:49 GMT Received: from abhmp0014.oracle.com (abhmp0014.oracle.com [141.146.116.20]) by userz7022.oracle.com (8.14.5+Sun/8.14.4) with ESMTP id sB42ilCT005805; Thu, 4 Dec 2014 02:44:48 GMT Received: from mojo.mkp.net (/141.144.6.238) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 03 Dec 2014 18:44:47 -0800 To: Tejun Heo Cc: linux-ide@vger.kernel.org Subject: [PATCH] libata: Whitelist SSDs that are known to properly return zeroes after TRIM From: "Martin K. Petersen" Organization: Oracle Date: Wed, 03 Dec 2014 21:44:46 -0500 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 X-Source-IP: ucsinet22.oracle.com [156.151.31.94] Sender: linux-ide-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ide@vger.kernel.org As defined, the DRAT (Deterministic Read After Trim) and RZAT (Return Zero After Trim) flags in the ATA Command Set are unreliable in the sense that they only define what happens if the device successfully executed the DSM TRIM command. TRIM is only advisory, however, and the device is free to silently ignore all or parts of the request. In practice this renders the DRAT and RZAT flags completely useless and because the results are unpredictable we decided to disable discard in MD for 3.18 to avoid the risk of data corruption. Hardware vendors in the real world obviously need better guarantees than what the standards bodies provide. Unfortuntely those guarantees are encoded in product requirements documents rather than somewhere we can key off of them programatically. So we are compelled to disabling discard_zeroes_data for all devices unless we explicitly have data to support whitelisting them. This patch whitelists SSDs from a few of the main vendors. None of the whitelists are based on written guarantees. They are purely based on empirical evidence collected from internal and external users that have tested or qualified these drives in RAID deployments. The whitelist is only meant as a starting point and is by no means comprehensive: - All intel SSD models except for 510 - Micron M5* - Samsung SSDs - Seagate SSDs Signed-off-by: Martin K. Petersen Reviewed-by: Christoph Hellwig --- drivers/ata/libata-core.c | 18 ++++++++++++++---- drivers/ata/libata-scsi.c | 10 ++++++---- include/linux/libata.h | 1 + 3 files changed, 21 insertions(+), 8 deletions(-) diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index c5ba15af87d3..f41f24a8bc21 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -4225,10 +4225,20 @@ static const struct ata_blacklist_entry ata_device_blacklist [] = { { "PIONEER DVD-RW DVR-216D", NULL, ATA_HORKAGE_NOSETXFER }, /* devices that don't properly handle queued TRIM commands */ - { "Micron_M500*", NULL, ATA_HORKAGE_NO_NCQ_TRIM, }, - { "Crucial_CT???M500SSD*", NULL, ATA_HORKAGE_NO_NCQ_TRIM, }, - { "Micron_M550*", NULL, ATA_HORKAGE_NO_NCQ_TRIM, }, - { "Crucial_CT*M550SSD*", NULL, ATA_HORKAGE_NO_NCQ_TRIM, }, + { "Micron_M5?0*", NULL, ATA_HORKAGE_NO_NCQ_TRIM | + ATA_HORKAGE_ZERO_AFTER_TRIM, }, + { "Crucial_CT???M5?0SSD*", NULL, ATA_HORKAGE_NO_NCQ_TRIM, }, + + /* + * DRAT/RZAT are weak guarantees. Explicitly black/whitelist + * SSDs that provide reliable zero after TRIM. + */ + { "INTEL*SSDSC2MH*", NULL, 0, }, /* Blacklist intel 510 */ + { "INTEL*SSD*", NULL, ATA_HORKAGE_ZERO_AFTER_TRIM, }, + { "SSD*INTEL*", NULL, ATA_HORKAGE_ZERO_AFTER_TRIM, }, + { "Samsung*SSD*", NULL, ATA_HORKAGE_ZERO_AFTER_TRIM, }, + { "SAMSUNG*SSD*", NULL, ATA_HORKAGE_ZERO_AFTER_TRIM, }, + { "ST[1248][0248]0[FH]*", NULL, ATA_HORKAGE_ZERO_AFTER_TRIM, }, /* * Some WD SATA-I drives spin up and down erratically when the link diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index 0586f66d70fa..a19479282b65 100644 --- a/drivers/ata/libata-scsi.c +++ b/drivers/ata/libata-scsi.c @@ -2515,13 +2515,15 @@ static unsigned int ata_scsiop_read_cap(struct ata_scsi_args *args, u8 *rbuf) rbuf[15] = lowest_aligned; if (ata_id_has_trim(args->id)) { - rbuf[14] |= 0x80; /* TPE */ + rbuf[14] |= 0x80; /* LBPME */ - if (ata_id_has_zero_after_trim(args->id)) - rbuf[14] |= 0x40; /* TPRZ */ + if (ata_id_has_zero_after_trim(args->id) && + dev->horkage & ATA_HORKAGE_ZERO_AFTER_TRIM) { + ata_dev_info(dev, "Enabling discard_zeroes_data\n"); + rbuf[14] |= 0x40; /* LBPRZ */ + } } } - return 0; } diff --git a/include/linux/libata.h b/include/linux/libata.h index bd5fefeaf548..45ac825b8366 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -421,6 +421,7 @@ enum { ATA_HORKAGE_NO_NCQ_TRIM = (1 << 19), /* don't use queued TRIM */ ATA_HORKAGE_NOLPM = (1 << 20), /* don't use LPM */ ATA_HORKAGE_WD_BROKEN_LPM = (1 << 21), /* some WDs have broken LPM */ + ATA_HORKAGE_ZERO_AFTER_TRIM = (1 << 22),/* guarantees zero after trim */ /* DMA mask for user DMA control: User visible values; DO NOT renumber */