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" <aneesh.ku...@linux.ibm.com> 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 <aneesh.ku...@linux.ibm.com>
> ---
> 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
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