From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161540AbcFBQ7Q (ORCPT ); Thu, 2 Jun 2016 12:59:16 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:17226 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1161516AbcFBQ7J (ORCPT ); Thu, 2 Jun 2016 12:59:09 -0400 Authentication-Results: gmail.com; dkim=none (message not signed) header.d=none;gmail.com; dmarc=none action=none header.from=fb.com; Date: Thu, 2 Jun 2016 09:58:13 -0700 From: Shaohua Li To: Sitsofe Wheeler , CC: , , , , , Subject: Re: [PATCH] block: correctly fallback for zeroout Message-ID: <20160602165813.GA18527@shli-mbp.local> References: <20160527054918.GA9521@sucs.org> <20160528092755.GB938@sucs.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20160528092755.GB938@sucs.org> User-Agent: Mutt/1.6.1 (2016-04-27) X-Originating-IP: [2620:10d:c090:200::3:d58a] X-ClientProxiedBy: BY1PR13CA0019.namprd13.prod.outlook.com (10.162.107.157) To CY1PR15MB0061.namprd15.prod.outlook.com (10.162.45.23) X-MS-Office365-Filtering-Correlation-Id: e69f4f03-4555-4015-ab66-08d38b071f02 X-Microsoft-Exchange-Diagnostics: 1;CY1PR15MB0061;2:JXMuZqhXtYS3ZLFrSzJvg7YJdhQBBT4s8UMUYs0ATSr2c4tMDsCvQ2WyapCwt4dwXkNKm5s21SOc7AF4u3dVzovvZa3D0EVll7IjbQPa22XIKxzYhqAUr6OaMHCARvGx+4PpjUZRFQNiJIN/94xlPDxmXPqZTJXD9WvrIuaz+wyprvsi3Yycy/H4tXjzrLxY;3:C2N99zHjwclnxQxvTb0lmrphl+9U+a4e/fMBZwNG3WHdKqYon8TCp3aQ+lsU1ERZTrh+rqvfN2srgk9vspcHMcKYf86THmU9DooIk44oJDRoDfpsbRLZHkhULqVLhI8M;25:Jn7j8s2Ekm9FOXnFa/YH/0dB4KoZuvttJ37lTc1+qtELr7Cw4WFW+0zrHMfuQPXsds5U890k9pudNVUYmR8ju1J6YF4LF4QMuYwWRanSUuB4Gzi7XAyR/6wXomQ6Az1FIt9PA1vAQxSOk1/hfaFmtXOu1PdMSDU3tJAIL7bqpb/XcmdSlE2lxvqtU/ZZ2Ep9etxmnZaY93tx4ZfuI9KVIIzrmMfUK08dFj/un6SL7prf6gQtcrNThj/PYSOh1CHnKrAVSpTjjugJzbg85veZvv5VvJW7T7JSblYs0P5LBE4/hVokWvjT9IkpXOwi1fkLUMtlw20jM1vbNYhOpl3FVY55W/IJpaJaTj3l2cRcmm8Nd4SEjzu2spnbhbCycG0A7hJKa2sXZAPG/hjQsVI5L8ueg7Y798qUeQSVqturkIA=;20:BwoVLwCqAuK1uxrDYwo6M0SoSg3DKKIKUdvHRsTkg9InQmfeO3EzZqrX6IgZmZT3dU0oBnoMSv30/jxQsKHXI1bPt5IYTUYRu9W//mqQRJbNh14vf9DAc96eQufQ7kKdVZNwGNwRanjM+MI08MuFJX0AsvFeNQp8qgJbOfxuczc= X-Microsoft-Antispam: UriScan:;BCL:0;PCL:0;RULEID:;SRVR:CY1PR15MB0061; X-LD-Processed: 8ae927fe-1255-47a7-a2af-5f3a069daaa2,ExtAddr X-Microsoft-Antispam-PRVS: X-Exchange-Antispam-Report-Test: UriScan:(201166117486090); X-Exchange-Antispam-Report-CFA-Test: BCL:0;PCL:0;RULEID:(601004)(2401047)(5005006)(8121501046)(10201501046)(3002001);SRVR:CY1PR15MB0061;BCL:0;PCL:0;RULEID:;SRVR:CY1PR15MB0061; X-Microsoft-Exchange-Diagnostics: 1;CY1PR15MB0061;4:KhwYvjFqiz1SqwjFQ9UHmdJwqmMqi6Gs2PwWsoFJ5d/8T/gYBcsKg+3DtlJTHQAWC6eA4yeljDDHHBcPjguBKkDBtajJ8JvkAPEfqGWPO0V8f2+9aftAl+kDyrRv4aHzGlmmI6wkISUGq0busEvrRtMLXNRoMGm29n9SDt77MC9IwCMkUpn1dqNEIw9sJyYt3I0UvDVgvrBTA/jP19odk2nG4Gpp1SyQPbI/61fhQj7IRrCXvfFVOBzeF+4VmxFQqwVMhyn48pq898TkJvqTAMTBFiCmUEfDokeDfwIp52nwg4NLqfg0wcaTHKp7gF2PCtmNRA5jZ9QAMLNf4b/vi3RKpCslLrGuS8nKCOwmE/03WvAe7/4RNFXFLwjHY/F4JuLXPk3g6AtQZ578ofKndyuudgZz19whQiAjXE+n5gE= X-Forefront-PRVS: 0961DF5286 X-Forefront-Antispam-Report: SFV:NSPM;SFS:(10019020)(4630300001)(6009001)(24454002)(86362001)(8676002)(4326007)(77096005)(81166006)(2950100001)(97756001)(2906002)(5008740100001)(50466002)(83506001)(54356999)(76176999)(9686002)(50986999)(5004730100002)(46406003)(42186005)(19580405001)(92566002)(586003)(5001770100001)(23726003)(4001350100001)(1076002)(189998001)(19580395003)(33656002)(98436002)(6116002)(47776003)(3826002);DIR:OUT;SFP:1102;SCL:1;SRVR:CY1PR15MB0061;H:shli-mbp.local;FPR:;SPF:None;MLV:sfv;LANG:en; X-Microsoft-Exchange-Diagnostics: =?us-ascii?Q?1;CY1PR15MB0061;23:eQnnabRhVyOh30m9wRIpuLuDNtIdDyrPMJGTjv3u0?= =?us-ascii?Q?IJsquy706CpFW5YSY0raSHH93watDCngT1/lpmj8qjBgDrg5O9+ZljY2yZn/?= =?us-ascii?Q?dpjYbcN41XzRJsKKqTyOuVjjAABuE3vEd+Iq9oYGWK/4r+oxhed2sdKvEtd0?= =?us-ascii?Q?WeHUQKABOORNFaXKkPZO8750SHjqVdjrmAzJ7lq8anh7xe1EWXd2214rm9Hm?= =?us-ascii?Q?gg5ScD7ti89Gsuft9Hy5UsXuLcJC6vGZCv+iwIo/M/rsPupFebxd4gp6U/yM?= =?us-ascii?Q?8X6++N1oZJwDxTgDdBgRxQiSNCGUpY8y8hsDFXA/gEPO4XoRHdmu+FhEAAaI?= =?us-ascii?Q?cAh7KxAdCjnzz9mDLayErZOjj7LWOjOs0G6oRrEIqyK2yqBaQMJSJZmfWwzM?= =?us-ascii?Q?mKgEK2hPtAl6pEmEmZSeLto3O8zh9+gxNJvYJIWCzNLdnGia+9tzJCJiu3M6?= =?us-ascii?Q?a5R5Oyu23Oqvclqgzt+aSaB5AYC1MY7U79oJgGPPbWtTejwcSdNOm9UZUQRJ?= =?us-ascii?Q?kRAHA5K8M8mqXsNHzmxVQ2HPz8x4cI2Y8hd6xUtJP1KJlT0Oc3lfdgp0xk9P?= =?us-ascii?Q?+jNIUH086rQMucjP6W276Cm3OcEDade58vkoADTvvHgYtm0IC0Ao+uUQO/GV?= =?us-ascii?Q?8hSBf4N/KX47phxJyjyvoYv0qImpqYBenZCzA+HGyjCoxMVjtDSAFdUfi0Ea?= =?us-ascii?Q?hyJVwwhJi2qbUVEqAqGvbzgp4e/a5nq/jsMxw1Gltocyul1Xeruz3vflP/sn?= =?us-ascii?Q?onQ8HDUoBFsk879w8Z6NF4qSbBr3eV8ayEsVZivr32VINsAHVKOFZdQjhgaP?= =?us-ascii?Q?sBZ14juY254Von8kgcRJui8jXyoTaQMqgnA0L+AHqDabSSWRqltrY3TX30+A?= =?us-ascii?Q?w0TnzVOsfoGaVw9FtupecSNfB9IR4g/nq/7fCM84MvpKEj92s7KT7nwuW6zT?= =?us-ascii?Q?nxdziozAqjN9AkjLHtF1Pfh3sDza9Qr5Dw1PKUWKw=3D=3D?= X-Microsoft-Exchange-Diagnostics: 1;CY1PR15MB0061;5:IczT+xSEgKws/FHfNQMKjMa8LCkyTCZMWYQRZHekDDBkd4DsUwHOX69PoXk8izSl0SK3+N7ozmXRqgPtobmEw4F59pOcCyl4tXbs1J4Km/EPESqsGxqBrdObiovdFaWKbThzPGrY1SOah1atEg7TmQ==;24:Z9nvy/CUAD6yu6XV6EGksEdI2kirVF1mkLiwp0wlSt88wcm8GDz46ZZajUgfDHgtf2t9jQpBRdH52IQMbjAGxe+BtIP1Ai/9pJjAn3jxeWw=;7:cfSyzBEX39KipCKoky2YWqabgEuyXuFwp6QkKdrsQUBqWXq62ir39QsJDNyod3AE53Xfoofex3m11c/NwyAPx+Ejjc/hcltJe2MN4CS5rGE7bnL/+7YrridOQnU4skCRcvCaURPIhB//6ATogX07Pr+/mmywVPJ0fow2GGgo+QXrsdEunFLut+bJQZoZf419;20:s6u+Pb73M1J1kJgFpPDztmoZPn9WtIJHHxoJLCAcG1j6lwM+nZKY4Vn4ytYrLlxNqhVycB6TROSbtwsX1VdVGLYOfeVomgy6eXXOkPf3S3g0n/PdvvLFA0h3Gm5a5DpQruVc0F5rh6JhDzZaX6ZfT+4kBItQQDhKLM/6/IOHdKw= SpamDiagnosticOutput: 1:23 SpamDiagnosticMetadata: NSPM X-MS-Exchange-CrossTenant-OriginalArrivalTime: 02 Jun 2016 16:58:23.4108 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY1PR15MB0061 X-OriginatorOrg: fb.com X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-06-02_05:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, May 28, 2016 at 10:27:55AM +0100, Sitsofe Wheeler wrote: > On Sat, May 28, 2016 at 08:55:43AM +0000, Sitsofe Wheeler wrote: > > On Thu, May 26, 2016 at 11:08:14AM -0700, Shaohua Li wrote: > > > blkdev_issue_zeroout try discard/writesame first, if they fail, zeroout > > > fallback to regular write. The problem is discard/writesame doesn't > > > return error for -EOPNOTSUPP, then zeroout can't do fallback and leave > > > disk data not changed. zeroout should have guaranteed zero-fill > > > behavior. > > > > It sounds like at least this patch should go in so BLKZEROOUT can always > > fall back (since those zeros are essential) but it would still be nice > > to see the disabling of write same being copied up to md device's > > write_same_max_bytes so everyone knows not to try using it in the future > > but perhaps someone will say "what if I re-enable it on the device > > below?" etc. > > I've tested Shaohua's original patch on top of Linus' tree and even > without the suggested changes (above and below) it at least resolves the > success being returned but data not being zeroed (with both PVSCSI and > scsi_debug underlying devices) issue so: > > Tested-by: Sitsofe Wheeler Jens, any chance you could merge this one? I'll fix the MD part later and make sure write_same_max_bytes sets to 0 after IO failure. Thanks, Shaohua