From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 2D46620214B40 for ; Mon, 19 Aug 2019 00:07:08 -0700 (PDT) Received: from pps.filterd (m0098393.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x7J730gq107710 for ; Mon, 19 Aug 2019 03:05:39 -0400 Received: from e06smtp02.uk.ibm.com (e06smtp02.uk.ibm.com [195.75.94.98]) by mx0a-001b2d01.pphosted.com with ESMTP id 2ufnsmtx3t-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 From: "Aneesh Kumar K.V" 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 Message-Id: <87y2zp1vph.fsf@linux.ibm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: Dan Williams Cc: Linux MM , linuxppc-dev , linux-nvdimm 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 _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm