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Violators will be prosecuted for from ; Thu, 30 May 2019 16:12:37 +0100 From: "Aneesh Kumar K.V" Subject: Re: [RFC PATCH V2 1/3] mm/nvdimm: Add PFN_MIN_VERSION support In-Reply-To: <20190522082701.6817-1-aneesh.kumar@linux.ibm.com> References: <20190522082701.6817-1-aneesh.kumar@linux.ibm.com> Date: Thu, 30 May 2019 20:42:32 +0530 MIME-Version: 1.0 Message-Id: <874l5c563j.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.j.williams@intel.com Cc: linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-nvdimm@lists.01.org List-ID: Hi Dan, Are you ok with this patch series? If yes I can send a non-RFC version for this series. Since we are now marking all previously created pfn_sb on ppc64 as not supported, (pfn_sb->page_size = SZ_4K) I would like to get this merged early. -aneesh "Aneesh Kumar K.V" writes: > 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. > > The error looks like > > dax0.1: init failed, superblock min version 1, kernel support version 0 > > and the namespace is marked disabled > > $ndctl list -Ni > [ > { > "dev":"namespace0.0", > "mode":"fsdax", > "map":"mem", > "size":10737418240, > "uuid":"9605de6d-cefa-4a87-99cd-dec28b02cffe", > "state":"disabled" > } > ] > > Signed-off-by: Aneesh Kumar K.V > --- > drivers/nvdimm/pfn.h | 9 ++++++++- > drivers/nvdimm/pfn_devs.c | 8 ++++++++ > drivers/nvdimm/pmem.c | 26 ++++++++++++++++++++++---- > 3 files changed, 38 insertions(+), 5 deletions(-) > > diff --git a/drivers/nvdimm/pfn.h b/drivers/nvdimm/pfn.h > index dde9853453d3..5fd29242745a 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_version; > + u8 padding[3998]; > __le64 checksum; > }; > > diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c > index 01f40672507f..a2268cf262f5 100644 > --- a/drivers/nvdimm/pfn_devs.c > +++ b/drivers/nvdimm/pfn_devs.c > @@ -439,6 +439,13 @@ 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) { > + dev_err(&nd_pfn->dev, > + "init failed, superblock min version %ld kernel support version %ld\n", > + le16_to_cpu(pfn_sb->min_version), PFN_MIN_VERSION); > + return -EOPNOTSUPP; > + } > + > if (memcmp(pfn_sb->signature, sig, PFN_SIG_LEN) != 0) > return -ENODEV; > > @@ -769,6 +776,7 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn) > memcpy(pfn_sb->parent_uuid, nd_dev_to_uuid(&ndns->dev), 16); > pfn_sb->version_major = cpu_to_le16(1); > pfn_sb->version_minor = cpu_to_le16(2); > + pfn_sb->min_version = cpu_to_le16(PFN_MIN_VERSION); > pfn_sb->start_pad = cpu_to_le32(start_pad); > pfn_sb->end_trunc = cpu_to_le32(end_trunc); > pfn_sb->align = cpu_to_le32(nd_pfn->align); > diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c > index 845c5b430cdd..406427c064d9 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) > + ret = nd_btt_probe(dev, ndns); > + if (ret == 0) > return -ENXIO; > + else if (ret == -EOPNOTSUPP) > + return ret; > > - /* ...otherwise we're just a raw pmem device */ > + ret = nd_pfn_probe(dev, ndns); > + if (ret == 0) > + return -ENXIO; > + else if (ret == -EOPNOTSUPP) > + return ret; > + > + ret = nd_dax_probe(dev, ndns); > + if (ret == 0) > + return -ENXIO; > + else if (ret == -EOPNOTSUPP) > + return ret; > + /* > + * We have two failure conditions here, there is no > + * info reserver block or we found a valid info reserve block > + * but failed to initialize the pfn superblock. > + * Don't create a raw pmem disk for the second case. > + */ > return pmem_attach_disk(dev, ndns); > } > > -- > 2.21.0 _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm