From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [RFC PATCH 1/3] mm/nvdimm: Add PFN_MIN_VERSION support References: <20190522062057.26581-1-aneesh.kumar@linux.ibm.com> From: "Aneesh Kumar K.V" Date: Wed, 22 May 2019 12:05:45 +0530 MIME-Version: 1.0 In-Reply-To: <20190522062057.26581-1-aneesh.kumar@linux.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Message-Id: <27bcf0e4-ba1d-2a7e-c181-ff60a9413bce@linux.ibm.com> Sender: owner-linux-mm@kvack.org To: dan.j.williams@intel.com Cc: linux-nvdimm@lists.01.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org List-ID: On 5/22/19 11:50 AM, Aneesh Kumar K.V wrote: > This allows us to make changes in a backward incompatible way. I have > kept the PFN_MIN_VERSION in this patch '0' because we are not introducing > any incompatible changes in this patch. We also may want to backport this > to older kernels. > > Signed-off-by: Aneesh Kumar K.V > --- > drivers/nvdimm/pfn.h | 9 ++++++++- > drivers/nvdimm/pfn_devs.c | 4 ++++ > drivers/nvdimm/pmem.c | 26 ++++++++++++++++++++++---- > 3 files changed, 34 insertions(+), 5 deletions(-) > > diff --git a/drivers/nvdimm/pfn.h b/drivers/nvdimm/pfn.h > index dde9853453d3..1b10ae5773b6 100644 > --- a/drivers/nvdimm/pfn.h > +++ b/drivers/nvdimm/pfn.h > @@ -20,6 +20,12 @@ > #define PFN_SIG_LEN 16 > #define PFN_SIG "NVDIMM_PFN_INFO\0" > #define DAX_SIG "NVDIMM_DAX_INFO\0" > +/* > + * increment this when we are making changes such that older > + * kernel should fail to initialize that namespace. > + */ > + > +#define PFN_MIN_VERSION 0 > > struct nd_pfn_sb { > u8 signature[PFN_SIG_LEN]; > @@ -36,7 +42,8 @@ struct nd_pfn_sb { > __le32 end_trunc; > /* minor-version-2 record the base alignment of the mapping */ > __le32 align; > - u8 padding[4000]; > + __le16 min_verison; > + u8 padding[3998]; > __le64 checksum; > }; > > diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c > index 01f40672507f..3250de70a7b3 100644 > --- a/drivers/nvdimm/pfn_devs.c > +++ b/drivers/nvdimm/pfn_devs.c > @@ -439,6 +439,9 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig) > if (nvdimm_read_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb), 0)) > return -ENXIO; > > + if (le16_to_cpu(pfn_sb->min_version > PFN_MIN_VERSION)) > + return -EOPNOTSUPP; + if (le16_to_cpu(pfn_sb->min_version) > PFN_MIN_VERSION) + return -EOPNOTSUPP; -aneesh 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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 9753EC072A4 for ; Wed, 22 May 2019 06:37:11 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E132020863 for ; Wed, 22 May 2019 06:37:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E132020863 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=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4582x06rbvzDqQx for ; Wed, 22 May 2019 16:37:08 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=linux.ibm.com (client-ip=148.163.158.5; helo=mx0a-001b2d01.pphosted.com; envelope-from=aneesh.kumar@linux.ibm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.ibm.com Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4582vc07KxzDqHP for ; Wed, 22 May 2019 16:35:55 +1000 (AEST) Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x4M6XYBC001150 for ; Wed, 22 May 2019 02:35:52 -0400 Received: from e36.co.us.ibm.com (e36.co.us.ibm.com [32.97.110.154]) by mx0b-001b2d01.pphosted.com with ESMTP id 2sn039tpk7-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 22 May 2019 02:35:52 -0400 Received: from localhost by e36.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Wed, 22 May 2019 07:35:48 +0100 Received: from b03ledav004.gho.boulder.ibm.com (b03ledav004.gho.boulder.ibm.com [9.17.130.235]) by b03cxnp08025.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x4M6ZlS124510908 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 22 May 2019 06:35:48 GMT Received: from b03ledav004.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id CC79778066; Wed, 22 May 2019 06:35:47 +0000 (GMT) Received: from b03ledav004.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 92C897805C; Wed, 22 May 2019 06:35:46 +0000 (GMT) Received: from [9.124.31.87] (unknown [9.124.31.87]) by b03ledav004.gho.boulder.ibm.com (Postfix) with ESMTP; Wed, 22 May 2019 06:35:46 +0000 (GMT) Subject: Re: [RFC PATCH 1/3] mm/nvdimm: Add PFN_MIN_VERSION support To: dan.j.williams@intel.com References: <20190522062057.26581-1-aneesh.kumar@linux.ibm.com> From: "Aneesh Kumar K.V" Date: Wed, 22 May 2019 12:05:45 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190522062057.26581-1-aneesh.kumar@linux.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 19052206-0020-0000-0000-00000EEE87E9 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00011141; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000286; SDB=6.01206848; UDB=6.00633758; IPR=6.00987824; MB=3.00026997; MTD=3.00000008; XFM=3.00000015; UTC=2019-05-22 06:35:50 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19052206-0021-0000-0000-000065EBBC02 Message-Id: <27bcf0e4-ba1d-2a7e-c181-ff60a9413bce@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-05-22_03:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 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=8.0.1-1810050000 definitions=main-1905220048 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-nvdimm@lists.01.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 5/22/19 11:50 AM, Aneesh Kumar K.V wrote: > This allows us to make changes in a backward incompatible way. I have > kept the PFN_MIN_VERSION in this patch '0' because we are not introducing > any incompatible changes in this patch. We also may want to backport this > to older kernels. > > Signed-off-by: Aneesh Kumar K.V > --- > drivers/nvdimm/pfn.h | 9 ++++++++- > drivers/nvdimm/pfn_devs.c | 4 ++++ > drivers/nvdimm/pmem.c | 26 ++++++++++++++++++++++---- > 3 files changed, 34 insertions(+), 5 deletions(-) > > diff --git a/drivers/nvdimm/pfn.h b/drivers/nvdimm/pfn.h > index dde9853453d3..1b10ae5773b6 100644 > --- a/drivers/nvdimm/pfn.h > +++ b/drivers/nvdimm/pfn.h > @@ -20,6 +20,12 @@ > #define PFN_SIG_LEN 16 > #define PFN_SIG "NVDIMM_PFN_INFO\0" > #define DAX_SIG "NVDIMM_DAX_INFO\0" > +/* > + * increment this when we are making changes such that older > + * kernel should fail to initialize that namespace. > + */ > + > +#define PFN_MIN_VERSION 0 > > struct nd_pfn_sb { > u8 signature[PFN_SIG_LEN]; > @@ -36,7 +42,8 @@ struct nd_pfn_sb { > __le32 end_trunc; > /* minor-version-2 record the base alignment of the mapping */ > __le32 align; > - u8 padding[4000]; > + __le16 min_verison; > + u8 padding[3998]; > __le64 checksum; > }; > > diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c > index 01f40672507f..3250de70a7b3 100644 > --- a/drivers/nvdimm/pfn_devs.c > +++ b/drivers/nvdimm/pfn_devs.c > @@ -439,6 +439,9 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig) > if (nvdimm_read_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb), 0)) > return -ENXIO; > > + if (le16_to_cpu(pfn_sb->min_version > PFN_MIN_VERSION)) > + return -EOPNOTSUPP; + if (le16_to_cpu(pfn_sb->min_version) > PFN_MIN_VERSION) + return -EOPNOTSUPP; -aneesh