From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2FAF3C3A59B for ; Mon, 19 Aug 2019 07:05:41 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id DFA8C20874 for ; Mon, 19 Aug 2019 07:05:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DFA8C20874 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 741986B000C; Mon, 19 Aug 2019 03:05:40 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6F1E56B000D; Mon, 19 Aug 2019 03:05:40 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5DF296B000E; Mon, 19 Aug 2019 03:05:40 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0145.hostedemail.com [216.40.44.145]) by kanga.kvack.org (Postfix) with ESMTP id 37A736B000C for ; Mon, 19 Aug 2019 03:05:40 -0400 (EDT) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with SMTP id CAAC02C8B for ; Mon, 19 Aug 2019 07:05:39 +0000 (UTC) X-FDA: 75838291998.12.verse94_3165c45508752 X-HE-Tag: verse94_3165c45508752 X-Filterd-Recvd-Size: 7369 Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) by imf40.hostedemail.com (Postfix) with ESMTP for ; Mon, 19 Aug 2019 07:05:39 +0000 (UTC) Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x7J72U3m142599 for ; Mon, 19 Aug 2019 03:05:38 -0400 Received: from e06smtp02.uk.ibm.com (e06smtp02.uk.ibm.com [195.75.94.98]) by mx0b-001b2d01.pphosted.com with ESMTP id 2ufn6ec62j-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 19 Aug 2019 03:05:38 -0400 Received: from localhost by e06smtp02.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 19 Aug 2019 08:05:36 +0100 Received: from b06cxnps3074.portsmouth.uk.ibm.com (9.149.109.194) by e06smtp02.uk.ibm.com (192.168.101.132) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Mon, 19 Aug 2019 08:05:33 +0100 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x7J75WWR13107280 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 19 Aug 2019 07:05:32 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 95AFD52054; Mon, 19 Aug 2019 07:05:32 +0000 (GMT) Received: from skywalker.linux.ibm.com (unknown [9.124.35.64]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id B12A352051; Mon, 19 Aug 2019 07:05:31 +0000 (GMT) X-Mailer: emacs 26.2 (via feedmail 11-beta-1 I) From: "Aneesh Kumar K.V" To: Dan Williams Cc: linux-nvdimm , Linux MM , linuxppc-dev Subject: Re: [PATCH v5 1/4] nvdimm: Consider probe return -EOPNOTSUPP as success In-Reply-To: References: <20190809074520.27115-1-aneesh.kumar@linux.ibm.com> <20190809074520.27115-2-aneesh.kumar@linux.ibm.com> Date: Mon, 19 Aug 2019 12:35:30 +0530 MIME-Version: 1.0 Content-Type: text/plain X-TM-AS-GCONF: 00 x-cbid: 19081907-0008-0000-0000-0000030A9AB1 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19081907-0009-0000-0000-00004A28BCAB Message-Id: <87y2zp1vph.fsf@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-08-19_02:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1908190081 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Dan Williams writes: > On Tue, Aug 13, 2019 at 9:22 PM Dan Williams wrote: >> >> Hi Aneesh, logic looks correct but there are some cleanups I'd like to >> see and a lead-in patch that I attached. >> >> I've started prefixing nvdimm patches with: >> >> libnvdimm/$component: >> >> ...since this patch mostly impacts the pmem driver lets prefix it >> "libnvdimm/pmem: " >> >> On Fri, Aug 9, 2019 at 12:45 AM Aneesh Kumar K.V >> wrote: >> > >> > This patch add -EOPNOTSUPP as return from probe callback to >> >> s/This patch add/Add/ >> >> No need to say "this patch" it's obviously a patch. >> >> > indicate we were not able to initialize a namespace due to pfn superblock >> > feature/version mismatch. We want to consider this a probe success so that >> > we can create new namesapce seed and there by avoid marking the failed >> > namespace as the seed namespace. >> >> Please replace usage of "we" with the exact agent involved as which >> "we" is being referred to gets confusing for the reader. >> >> i.e. "indicate that the pmem driver was not..." "The nvdimm core wants >> to consider this...". >> >> > >> > Signed-off-by: Aneesh Kumar K.V >> > --- >> > drivers/nvdimm/bus.c | 2 +- >> > drivers/nvdimm/pmem.c | 26 ++++++++++++++++++++++---- >> > 2 files changed, 23 insertions(+), 5 deletions(-) >> > >> > diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c >> > index 798c5c4aea9c..16c35e6446a7 100644 >> > --- a/drivers/nvdimm/bus.c >> > +++ b/drivers/nvdimm/bus.c >> > @@ -95,7 +95,7 @@ static int nvdimm_bus_probe(struct device *dev) >> > rc = nd_drv->probe(dev); >> > debug_nvdimm_unlock(dev); >> > >> > - if (rc == 0) >> > + if (rc == 0 || rc == -EOPNOTSUPP) >> > nd_region_probe_success(nvdimm_bus, dev); >> >> This now makes the nd_region_probe_success() helper obviously misnamed >> since it now wants to take actions on non-probe success. I attached a >> lead-in cleanup that you can pull into your series that renames that >> routine to nd_region_advance_seeds(). >> >> When you rebase this needs a comment about why EOPNOTSUPP has special handling. >> >> > else >> > nd_region_disable(nvdimm_bus, dev); >> > diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c >> > index 4c121dd03dd9..3f498881dd28 100644 >> > --- a/drivers/nvdimm/pmem.c >> > +++ b/drivers/nvdimm/pmem.c >> > @@ -490,6 +490,7 @@ static int pmem_attach_disk(struct device *dev, >> > >> > static int nd_pmem_probe(struct device *dev) >> > { >> > + int ret; >> > struct nd_namespace_common *ndns; >> > >> > ndns = nvdimm_namespace_common_probe(dev); >> > @@ -505,12 +506,29 @@ static int nd_pmem_probe(struct device *dev) >> > if (is_nd_pfn(dev)) >> > return pmem_attach_disk(dev, ndns); >> > >> > - /* if we find a valid info-block we'll come back as that personality */ >> > - if (nd_btt_probe(dev, ndns) == 0 || nd_pfn_probe(dev, ndns) == 0 >> > - || nd_dax_probe(dev, ndns) == 0) >> >> Similar need for an updated comment here to explain the special >> translation of error codes. >> >> > + ret = nd_btt_probe(dev, ndns); >> > + if (ret == 0) >> > return -ENXIO; >> > + else if (ret == -EOPNOTSUPP) >> >> Are there cases where the btt driver needs to return EOPNOTSUPP? I'd >> otherwise like to keep this special casing constrained to the pfn / >> dax info block cases. > > In fact I think EOPNOTSUPP is only something that the device-dax case > would be concerned with because that's the only interface that > attempts to guarantee a given mapping granularity. We need to do similar error handling w.r.t fsdax when the pfn superblock indicates different PAGE_SIZE and struct page size? I don't think btt needs to support EOPNOTSUPP. But we can keep it for consistency? -aneesh