[RFC PATCH 1/3] mm/nvdimm: Add PFN_MIN_VERSION support

[RFC PATCH 1/3] mm/nvdimm: Add PFN_MIN_VERSION support

[Aneesh Kumar K.V]

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 <aneesh.kumar@linux.ibm.com>
---
 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 (memcmp(pfn_sb->signature, sig, PFN_SIG_LEN) != 0)
 		return -ENODEV;
 
@@ -769,6 +772,7 @@ 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

[RFC PATCH 1/3] mm/nvdimm: Add PFN_MIN_VERSION support

[Aneesh Kumar K.V]

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 <aneesh.kumar@linux.ibm.com>
---
 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 (memcmp(pfn_sb->signature, sig, PFN_SIG_LEN) != 0)
 		return -ENODEV;
 
@@ -769,6 +772,7 @@ 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

[RFC PATCH 2/3] mm/nvdimm: Add page size and struct page size to pfn superblock

[Aneesh Kumar K.V]

This is needed so that we don't wrongly initialize a namespace
which doesn't have enough space reserved for holding struct pages
with the current kernel.

We also increment PFN_MIN_VERSION to make sure that older kernel
won't initialize namespace created with newer kernel.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 drivers/nvdimm/pfn.h      |  9 ++++++---
 drivers/nvdimm/pfn_devs.c | 19 ++++++++++++++++++-
 2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/drivers/nvdimm/pfn.h b/drivers/nvdimm/pfn.h
index 1b10ae5773b6..ba11738ca8a2 100644
--- a/drivers/nvdimm/pfn.h
+++ b/drivers/nvdimm/pfn.h
@@ -25,7 +25,7 @@
  * kernel should fail to initialize that namespace.
  */
 
-#define PFN_MIN_VERSION 0
+#define PFN_MIN_VERSION 1
 
 struct nd_pfn_sb {
 	u8 signature[PFN_SIG_LEN];
@@ -42,8 +42,11 @@ struct nd_pfn_sb {
 	__le32 end_trunc;
 	/* minor-version-2 record the base alignment of the mapping */
 	__le32 align;
-	__le16 min_verison;
-	u8 padding[3998];
+	__le16 min_version;
+	/* minor-version-3 record the page size and struct page size */
+	__le16 page_struct_size;
+	__le32 page_size;
+	u8 padding[3992];
 	__le64 checksum;
 };
 
diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index 3250de70a7b3..94918a4e6e73 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -462,6 +462,15 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig)
 	if (__le16_to_cpu(pfn_sb->version_minor) < 2)
 		pfn_sb->align = 0;
 
+	if (__le16_to_cpu(pfn_sb->version_minor) < 3) {
+		/*
+		 * For a large part we use PAGE_SIZE. But we
+		 * do have some accounting code using SZ_4K.
+		 */
+		pfn_sb->page_struct_size = cpu_to_le16(64);
+		pfn_sb->page_size = cpu_to_le32(SZ_4K);
+	}
+
 	switch (le32_to_cpu(pfn_sb->mode)) {
 	case PFN_MODE_RAM:
 	case PFN_MODE_PMEM:
@@ -477,6 +486,12 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig)
 		align = 1UL << ilog2(offset);
 	mode = le32_to_cpu(pfn_sb->mode);
 
+	if (le32_to_cpu(pfn_sb->page_size) != PAGE_SIZE)
+		return -EOPNOTSUPP;
+
+	if (le16_to_cpu(pfn_sb->page_struct_size) != sizeof(struct page))
+		return -EOPNOTSUPP;
+
 	if (!nd_pfn->uuid) {
 		/*
 		 * When probing a namepace via nd_pfn_probe() the uuid
@@ -771,11 +786,13 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn)
 	memcpy(pfn_sb->uuid, nd_pfn->uuid, 16);
 	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->version_minor = cpu_to_le16(3);
 	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);
+	pfn_sb->page_struct_size = cpu_to_le16(sizeof(struct page));
+	pfn_sb->page_size = cpu_to_le32(PAGE_SIZE);
 	checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
 	pfn_sb->checksum = cpu_to_le64(checksum);
 
-- 
2.21.0

_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm

[RFC PATCH 2/3] mm/nvdimm: Add page size and struct page size to pfn superblock

[Aneesh Kumar K.V]

This is needed so that we don't wrongly initialize a namespace
which doesn't have enough space reserved for holding struct pages
with the current kernel.

We also increment PFN_MIN_VERSION to make sure that older kernel
won't initialize namespace created with newer kernel.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 drivers/nvdimm/pfn.h      |  9 ++++++---
 drivers/nvdimm/pfn_devs.c | 19 ++++++++++++++++++-
 2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/drivers/nvdimm/pfn.h b/drivers/nvdimm/pfn.h
index 1b10ae5773b6..ba11738ca8a2 100644
--- a/drivers/nvdimm/pfn.h
+++ b/drivers/nvdimm/pfn.h
@@ -25,7 +25,7 @@
  * kernel should fail to initialize that namespace.
  */
 
-#define PFN_MIN_VERSION 0
+#define PFN_MIN_VERSION 1
 
 struct nd_pfn_sb {
 	u8 signature[PFN_SIG_LEN];
@@ -42,8 +42,11 @@ struct nd_pfn_sb {
 	__le32 end_trunc;
 	/* minor-version-2 record the base alignment of the mapping */
 	__le32 align;
-	__le16 min_verison;
-	u8 padding[3998];
+	__le16 min_version;
+	/* minor-version-3 record the page size and struct page size */
+	__le16 page_struct_size;
+	__le32 page_size;
+	u8 padding[3992];
 	__le64 checksum;
 };
 
diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index 3250de70a7b3..94918a4e6e73 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -462,6 +462,15 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig)
 	if (__le16_to_cpu(pfn_sb->version_minor) < 2)
 		pfn_sb->align = 0;
 
+	if (__le16_to_cpu(pfn_sb->version_minor) < 3) {
+		/*
+		 * For a large part we use PAGE_SIZE. But we
+		 * do have some accounting code using SZ_4K.
+		 */
+		pfn_sb->page_struct_size = cpu_to_le16(64);
+		pfn_sb->page_size = cpu_to_le32(SZ_4K);
+	}
+
 	switch (le32_to_cpu(pfn_sb->mode)) {
 	case PFN_MODE_RAM:
 	case PFN_MODE_PMEM:
@@ -477,6 +486,12 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig)
 		align = 1UL << ilog2(offset);
 	mode = le32_to_cpu(pfn_sb->mode);
 
+	if (le32_to_cpu(pfn_sb->page_size) != PAGE_SIZE)
+		return -EOPNOTSUPP;
+
+	if (le16_to_cpu(pfn_sb->page_struct_size) != sizeof(struct page))
+		return -EOPNOTSUPP;
+
 	if (!nd_pfn->uuid) {
 		/*
 		 * When probing a namepace via nd_pfn_probe() the uuid
@@ -771,11 +786,13 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn)
 	memcpy(pfn_sb->uuid, nd_pfn->uuid, 16);
 	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->version_minor = cpu_to_le16(3);
 	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);
+	pfn_sb->page_struct_size = cpu_to_le16(sizeof(struct page));
+	pfn_sb->page_size = cpu_to_le32(PAGE_SIZE);
 	checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
 	pfn_sb->checksum = cpu_to_le64(checksum);
 
-- 
2.21.0

[RFC PATCH 2/3] mm/nvdimm: Add page size and struct page size to pfn superblock

[Aneesh Kumar K.V]

This is needed so that we don't wrongly initialize a namespace
which doesn't have enough space reserved for holding struct pages
with the current kernel.

We also increment PFN_MIN_VERSION to make sure that older kernel
won't initialize namespace created with newer kernel.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 drivers/nvdimm/pfn.h      |  9 ++++++---
 drivers/nvdimm/pfn_devs.c | 19 ++++++++++++++++++-
 2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/drivers/nvdimm/pfn.h b/drivers/nvdimm/pfn.h
index 1b10ae5773b6..ba11738ca8a2 100644
--- a/drivers/nvdimm/pfn.h
+++ b/drivers/nvdimm/pfn.h
@@ -25,7 +25,7 @@
  * kernel should fail to initialize that namespace.
  */
 
-#define PFN_MIN_VERSION 0
+#define PFN_MIN_VERSION 1
 
 struct nd_pfn_sb {
 	u8 signature[PFN_SIG_LEN];
@@ -42,8 +42,11 @@ struct nd_pfn_sb {
 	__le32 end_trunc;
 	/* minor-version-2 record the base alignment of the mapping */
 	__le32 align;
-	__le16 min_verison;
-	u8 padding[3998];
+	__le16 min_version;
+	/* minor-version-3 record the page size and struct page size */
+	__le16 page_struct_size;
+	__le32 page_size;
+	u8 padding[3992];
 	__le64 checksum;
 };
 
diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index 3250de70a7b3..94918a4e6e73 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -462,6 +462,15 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig)
 	if (__le16_to_cpu(pfn_sb->version_minor) < 2)
 		pfn_sb->align = 0;
 
+	if (__le16_to_cpu(pfn_sb->version_minor) < 3) {
+		/*
+		 * For a large part we use PAGE_SIZE. But we
+		 * do have some accounting code using SZ_4K.
+		 */
+		pfn_sb->page_struct_size = cpu_to_le16(64);
+		pfn_sb->page_size = cpu_to_le32(SZ_4K);
+	}
+
 	switch (le32_to_cpu(pfn_sb->mode)) {
 	case PFN_MODE_RAM:
 	case PFN_MODE_PMEM:
@@ -477,6 +486,12 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig)
 		align = 1UL << ilog2(offset);
 	mode = le32_to_cpu(pfn_sb->mode);
 
+	if (le32_to_cpu(pfn_sb->page_size) != PAGE_SIZE)
+		return -EOPNOTSUPP;
+
+	if (le16_to_cpu(pfn_sb->page_struct_size) != sizeof(struct page))
+		return -EOPNOTSUPP;
+
 	if (!nd_pfn->uuid) {
 		/*
 		 * When probing a namepace via nd_pfn_probe() the uuid
@@ -771,11 +786,13 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn)
 	memcpy(pfn_sb->uuid, nd_pfn->uuid, 16);
 	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->version_minor = cpu_to_le16(3);
 	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);
+	pfn_sb->page_struct_size = cpu_to_le16(sizeof(struct page));
+	pfn_sb->page_size = cpu_to_le32(PAGE_SIZE);
 	checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
 	pfn_sb->checksum = cpu_to_le64(checksum);
 
-- 
2.21.0

[RFC PATCH 3/3] mm/nvdimm: Use correct #defines instead of opencoding

[Aneesh Kumar K.V]

The nfpn related change is needed to fix the kernel message

"number of pfns truncated from 2617344 to 163584"

The change makes sure the nfpns stored in the superblock is right value.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 drivers/nvdimm/label.c       | 2 +-
 drivers/nvdimm/pfn_devs.c    | 6 +++---
 drivers/nvdimm/region_devs.c | 8 ++++----
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/nvdimm/label.c b/drivers/nvdimm/label.c
index f3d753d3169c..bc6de8fb0153 100644
--- a/drivers/nvdimm/label.c
+++ b/drivers/nvdimm/label.c
@@ -361,7 +361,7 @@ static bool slot_valid(struct nvdimm_drvdata *ndd,
 
 	/* check that DPA allocations are page aligned */
 	if ((__le64_to_cpu(nd_label->dpa)
-				| __le64_to_cpu(nd_label->rawsize)) % SZ_4K)
+				| __le64_to_cpu(nd_label->rawsize)) % PAGE_SIZE)
 		return false;
 
 	/* check checksum */
diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index 94918a4e6e73..f549bddc680c 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -765,8 +765,8 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn)
 		 * when populating the vmemmap. This *should* be equal to
 		 * PMD_SIZE for most architectures.
 		 */
-		offset = ALIGN(start + reserve + 64 * npfns,
-				max(nd_pfn->align, PMD_SIZE)) - start;
+		offset = ALIGN(start + reserve + sizeof(struct page) * npfns,
+			       max(nd_pfn->align, PMD_SIZE)) - start;
 	} else if (nd_pfn->mode == PFN_MODE_RAM)
 		offset = ALIGN(start + reserve, nd_pfn->align) - start;
 	else
@@ -778,7 +778,7 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn)
 		return -ENXIO;
 	}
 
-	npfns = (size - offset - start_pad - end_trunc) / SZ_4K;
+	npfns = (size - offset - start_pad - end_trunc) / PAGE_SIZE;
 	pfn_sb->mode = cpu_to_le32(nd_pfn->mode);
 	pfn_sb->dataoff = cpu_to_le64(offset);
 	pfn_sb->npfns = cpu_to_le64(npfns);
diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
index b4ef7d9ff22e..2d8facea5a03 100644
--- a/drivers/nvdimm/region_devs.c
+++ b/drivers/nvdimm/region_devs.c
@@ -994,10 +994,10 @@ static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
 		struct nd_mapping_desc *mapping = &ndr_desc->mapping[i];
 		struct nvdimm *nvdimm = mapping->nvdimm;
 
-		if ((mapping->start | mapping->size) % SZ_4K) {
-			dev_err(&nvdimm_bus->dev, "%s: %s mapping%d is not 4K aligned\n",
-					caller, dev_name(&nvdimm->dev), i);
-
+		if ((mapping->start | mapping->size) % PAGE_SIZE) {
+			dev_err(&nvdimm_bus->dev,
+				"%s: %s mapping%d is not 4K aligned\n",
+				caller, dev_name(&nvdimm->dev), i);
 			return NULL;
 		}
 
-- 
2.21.0

[RFC PATCH 3/3] mm/nvdimm: Use correct #defines instead of opencoding

[Aneesh Kumar K.V]

The nfpn related change is needed to fix the kernel message

"number of pfns truncated from 2617344 to 163584"

The change makes sure the nfpns stored in the superblock is right value.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 drivers/nvdimm/label.c       | 2 +-
 drivers/nvdimm/pfn_devs.c    | 6 +++---
 drivers/nvdimm/region_devs.c | 8 ++++----
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/nvdimm/label.c b/drivers/nvdimm/label.c
index f3d753d3169c..bc6de8fb0153 100644
--- a/drivers/nvdimm/label.c
+++ b/drivers/nvdimm/label.c
@@ -361,7 +361,7 @@ static bool slot_valid(struct nvdimm_drvdata *ndd,
 
 	/* check that DPA allocations are page aligned */
 	if ((__le64_to_cpu(nd_label->dpa)
-				| __le64_to_cpu(nd_label->rawsize)) % SZ_4K)
+				| __le64_to_cpu(nd_label->rawsize)) % PAGE_SIZE)
 		return false;
 
 	/* check checksum */
diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index 94918a4e6e73..f549bddc680c 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -765,8 +765,8 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn)
 		 * when populating the vmemmap. This *should* be equal to
 		 * PMD_SIZE for most architectures.
 		 */
-		offset = ALIGN(start + reserve + 64 * npfns,
-				max(nd_pfn->align, PMD_SIZE)) - start;
+		offset = ALIGN(start + reserve + sizeof(struct page) * npfns,
+			       max(nd_pfn->align, PMD_SIZE)) - start;
 	} else if (nd_pfn->mode == PFN_MODE_RAM)
 		offset = ALIGN(start + reserve, nd_pfn->align) - start;
 	else
@@ -778,7 +778,7 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn)
 		return -ENXIO;
 	}
 
-	npfns = (size - offset - start_pad - end_trunc) / SZ_4K;
+	npfns = (size - offset - start_pad - end_trunc) / PAGE_SIZE;
 	pfn_sb->mode = cpu_to_le32(nd_pfn->mode);
 	pfn_sb->dataoff = cpu_to_le64(offset);
 	pfn_sb->npfns = cpu_to_le64(npfns);
diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
index b4ef7d9ff22e..2d8facea5a03 100644
--- a/drivers/nvdimm/region_devs.c
+++ b/drivers/nvdimm/region_devs.c
@@ -994,10 +994,10 @@ static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
 		struct nd_mapping_desc *mapping = &ndr_desc->mapping[i];
 		struct nvdimm *nvdimm = mapping->nvdimm;
 
-		if ((mapping->start | mapping->size) % SZ_4K) {
-			dev_err(&nvdimm_bus->dev, "%s: %s mapping%d is not 4K aligned\n",
-					caller, dev_name(&nvdimm->dev), i);
-
+		if ((mapping->start | mapping->size) % PAGE_SIZE) {
+			dev_err(&nvdimm_bus->dev,
+				"%s: %s mapping%d is not 4K aligned\n",
+				caller, dev_name(&nvdimm->dev), i);
 			return NULL;
 		}
 
-- 
2.21.0

Re: [RFC PATCH 1/3] mm/nvdimm: Add PFN_MIN_VERSION support

[Aneesh Kumar K.V]

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 <aneesh.kumar@linux.ibm.com>
> ---
>   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

Re: [RFC PATCH 1/3] mm/nvdimm: Add PFN_MIN_VERSION support

[Aneesh Kumar K.V]

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 <aneesh.kumar@linux.ibm.com>
> ---
>   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