[4.6 stable PATCH 0/2] libnvdimm: fix initialization vs autodetect

[4.6 stable PATCH 0/2] libnvdimm: fix initialization vs autodetect

[Dan Williams]

Commit 1ee6667cd8d1 "libnvdimm, pfn, dax: fix initialization vs
autodetect for mode + alignment" originally tagged for -stable does not
apply cleanly to 4.6.  This backport pulls in commit 45a0dac04511
"libnvdimm, dax: record the specified alignment of a dax-device
instance" as a pre-requisite.

The result has been verfied to pass the ndctl unit tests.

---

Dan Williams (2):
      libnvdimm, dax: record the specified alignment of a dax-device instance
      libnvdimm, pfn, dax: fix initialization vs autodetect for mode + alignment


 drivers/nvdimm/pfn.h      |    4 +++
 drivers/nvdimm/pfn_devs.c |   53 +++++++++++++++++++++++++++++++++++++--------
 drivers/nvdimm/pmem.c     |    4 ++-
 3 files changed, 49 insertions(+), 12 deletions(-)
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[4.6 stable PATCH 0/2] libnvdimm: fix initialization vs autodetect

[Dan Williams]

Commit 1ee6667cd8d1 "libnvdimm, pfn, dax: fix initialization vs
autodetect for mode + alignment" originally tagged for -stable does not
apply cleanly to 4.6.  This backport pulls in commit 45a0dac04511
"libnvdimm, dax: record the specified alignment of a dax-device
instance" as a pre-requisite.

The result has been verfied to pass the ndctl unit tests.

---

Dan Williams (2):
      libnvdimm, dax: record the specified alignment of a dax-device instance
      libnvdimm, pfn, dax: fix initialization vs autodetect for mode + alignment


 drivers/nvdimm/pfn.h      |    4 +++
 drivers/nvdimm/pfn_devs.c |   53 +++++++++++++++++++++++++++++++++++++--------
 drivers/nvdimm/pmem.c     |    4 ++-
 3 files changed, 49 insertions(+), 12 deletions(-)

[4.6 stable PATCH 1/2] libnvdimm, dax: record the specified alignment of a dax-device instance

[Dan Williams]

commit 45a0dac0451136fa7ae34a6fea53ef6a136287ce upstream.

We want to use the alignment as the allocation and mapping unit.
Previously this information was only useful for establishing the data
offset, but now it is important to remember the granularity for the
later use.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/nvdimm/pfn.h      |    4 +++-
 drivers/nvdimm/pfn_devs.c |    5 ++++-
 drivers/nvdimm/pmem.c     |    3 ++-
 3 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/nvdimm/pfn.h b/drivers/nvdimm/pfn.h
index 8e343a3ca873..9d2704c83fa7 100644
--- a/drivers/nvdimm/pfn.h
+++ b/drivers/nvdimm/pfn.h
@@ -33,7 +33,9 @@ struct nd_pfn_sb {
 	/* minor-version-1 additions for section alignment */
 	__le32 start_pad;
 	__le32 end_trunc;
-	u8 padding[4004];
+	/* minor-version-2 record the base alignment of the mapping */
+	__le32 align;
+	u8 padding[4000];
 	__le64 checksum;
 };
 
diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index e071e214feba..58bf68c9c414 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -360,6 +360,9 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn)
 		pfn_sb->end_trunc = 0;
 	}
 
+	if (__le16_to_cpu(pfn_sb->version_minor) < 2)
+		pfn_sb->align = 0;
+
 	switch (le32_to_cpu(pfn_sb->mode)) {
 	case PFN_MODE_RAM:
 	case PFN_MODE_PMEM:
@@ -399,7 +402,7 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn)
 		return -EBUSY;
 	}
 
-	nd_pfn->align = 1UL << ilog2(offset);
+	nd_pfn->align = le32_to_cpu(pfn_sb->align);
 	if (!is_power_of_2(offset) || offset < PAGE_SIZE) {
 		dev_err(&nd_pfn->dev, "bad offset: %#llx dax disabled\n",
 				offset);
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 92f536596b24..58ad81dcd1a5 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -426,9 +426,10 @@ 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(1);
+	pfn_sb->version_minor = cpu_to_le16(2);
 	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);
 	checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
 	pfn_sb->checksum = cpu_to_le64(checksum);
 

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[4.6 stable PATCH 1/2] libnvdimm, dax: record the specified alignment of a dax-device instance

[Dan Williams]

commit 45a0dac0451136fa7ae34a6fea53ef6a136287ce upstream.

We want to use the alignment as the allocation and mapping unit.
Previously this information was only useful for establishing the data
offset, but now it is important to remember the granularity for the
later use.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/nvdimm/pfn.h      |    4 +++-
 drivers/nvdimm/pfn_devs.c |    5 ++++-
 drivers/nvdimm/pmem.c     |    3 ++-
 3 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/nvdimm/pfn.h b/drivers/nvdimm/pfn.h
index 8e343a3ca873..9d2704c83fa7 100644
--- a/drivers/nvdimm/pfn.h
+++ b/drivers/nvdimm/pfn.h
@@ -33,7 +33,9 @@ struct nd_pfn_sb {
 	/* minor-version-1 additions for section alignment */
 	__le32 start_pad;
 	__le32 end_trunc;
-	u8 padding[4004];
+	/* minor-version-2 record the base alignment of the mapping */
+	__le32 align;
+	u8 padding[4000];
 	__le64 checksum;
 };
 
diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index e071e214feba..58bf68c9c414 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -360,6 +360,9 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn)
 		pfn_sb->end_trunc = 0;
 	}
 
+	if (__le16_to_cpu(pfn_sb->version_minor) < 2)
+		pfn_sb->align = 0;
+
 	switch (le32_to_cpu(pfn_sb->mode)) {
 	case PFN_MODE_RAM:
 	case PFN_MODE_PMEM:
@@ -399,7 +402,7 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn)
 		return -EBUSY;
 	}
 
-	nd_pfn->align = 1UL << ilog2(offset);
+	nd_pfn->align = le32_to_cpu(pfn_sb->align);
 	if (!is_power_of_2(offset) || offset < PAGE_SIZE) {
 		dev_err(&nd_pfn->dev, "bad offset: %#llx dax disabled\n",
 				offset);
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 92f536596b24..58ad81dcd1a5 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -426,9 +426,10 @@ 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(1);
+	pfn_sb->version_minor = cpu_to_le16(2);
 	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);
 	checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
 	pfn_sb->checksum = cpu_to_le64(checksum);
 

[4.6 stable PATCH 2/2] libnvdimm, pfn, dax: fix initialization vs autodetect for mode + alignment

[Dan Williams]

commit 1ee6667cd8d183b2fed12f97285f184431d2caf9 upstream.

The updated ndctl unit tests discovered that if a pfn configuration with
a 4K alignment is read from the namespace, that alignment will be
ignored in favor of the default 2M alignment.  The result is that the
configuration will fail initialization with a message like:

    dax6.1: bad offset: 0x22000 dax disabled align: 0x200000

Fix this by allowing the alignment read from the info block to override
the default which is 2M not 0 in the autodetect path.  This also fixes a
similar problem with the mode and alignment settings silently being
overwritten by the kernel when userspace has changed it.  We now will
either overwrite the info block if userspace changes the uuid or fail
and warn if a live setting disagrees with the info block.

Cc: <stable@vger.kernel.org>
Cc: Micah Parrish <micah.parrish@hpe.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/nvdimm/pfn_devs.c |   50 +++++++++++++++++++++++++++++++++++++--------
 drivers/nvdimm/pmem.c     |    1 -
 2 files changed, 41 insertions(+), 10 deletions(-)

diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index 58bf68c9c414..84f2372dd0bb 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -329,6 +329,8 @@ struct device *nd_pfn_create(struct nd_region *nd_region)
 int nd_pfn_validate(struct nd_pfn *nd_pfn)
 {
 	u64 checksum, offset;
+	unsigned long align;
+	enum nd_pfn_mode mode;
 	struct nd_namespace_io *nsio;
 	struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
 	struct nd_namespace_common *ndns = nd_pfn->ndns;
@@ -371,20 +373,50 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn)
 		return -ENXIO;
 	}
 
+	align = le32_to_cpu(pfn_sb->align);
+	offset = le64_to_cpu(pfn_sb->dataoff);
+	if (align == 0)
+		align = 1UL << ilog2(offset);
+	mode = le32_to_cpu(pfn_sb->mode);
+
 	if (!nd_pfn->uuid) {
-		/* from probe we allocate */
+		/*
+		 * When probing a namepace via nd_pfn_probe() the uuid
+		 * is NULL (see: nd_pfn_devinit()) we init settings from
+		 * pfn_sb
+		 */
 		nd_pfn->uuid = kmemdup(pfn_sb->uuid, 16, GFP_KERNEL);
 		if (!nd_pfn->uuid)
 			return -ENOMEM;
+		nd_pfn->align = align;
+		nd_pfn->mode = mode;
 	} else {
-		/* from init we validate */
+		/*
+		 * When probing a pfn / dax instance we validate the
+		 * live settings against the pfn_sb
+		 */
 		if (memcmp(nd_pfn->uuid, pfn_sb->uuid, 16) != 0)
 			return -ENODEV;
+
+		/*
+		 * If the uuid validates, but other settings mismatch
+		 * return EINVAL because userspace has managed to change
+		 * the configuration without specifying new
+		 * identification.
+		 */
+		if (nd_pfn->align != align || nd_pfn->mode != mode) {
+			dev_err(&nd_pfn->dev,
+					"init failed, settings mismatch\n");
+			dev_dbg(&nd_pfn->dev, "align: %lx:%lx mode: %d:%d\n",
+					nd_pfn->align, align, nd_pfn->mode,
+					mode);
+			return -EINVAL;
+		}
 	}
 
-	if (nd_pfn->align > nvdimm_namespace_capacity(ndns)) {
+	if (align > nvdimm_namespace_capacity(ndns)) {
 		dev_err(&nd_pfn->dev, "alignment: %lx exceeds capacity %llx\n",
-				nd_pfn->align, nvdimm_namespace_capacity(ndns));
+				align, nvdimm_namespace_capacity(ndns));
 		return -EINVAL;
 	}
 
@@ -394,7 +426,6 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn)
 	 * namespace has changed since the pfn superblock was
 	 * established.
 	 */
-	offset = le64_to_cpu(pfn_sb->dataoff);
 	nsio = to_nd_namespace_io(&ndns->dev);
 	if (offset >= resource_size(&nsio->res)) {
 		dev_err(&nd_pfn->dev, "pfn array size exceeds capacity of %s\n",
@@ -402,10 +433,11 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn)
 		return -EBUSY;
 	}
 
-	nd_pfn->align = le32_to_cpu(pfn_sb->align);
-	if (!is_power_of_2(offset) || offset < PAGE_SIZE) {
-		dev_err(&nd_pfn->dev, "bad offset: %#llx dax disabled\n",
-				offset);
+	if ((align && !IS_ALIGNED(offset, align))
+			|| !IS_ALIGNED(offset, PAGE_SIZE)) {
+		dev_err(&nd_pfn->dev,
+				"bad offset: %#llx dax disabled align: %#lx\n",
+				offset, align);
 		return -ENXIO;
 	}
 
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 58ad81dcd1a5..368efac7a950 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -502,7 +502,6 @@ static int __nvdimm_namespace_attach_pfn(struct nd_pfn *nd_pfn)
 	pmem = dev_get_drvdata(dev);
 	pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
 	pmem->pfn_pad = start_pad + end_trunc;
-	nd_pfn->mode = le32_to_cpu(nd_pfn->pfn_sb->mode);
 	if (nd_pfn->mode == PFN_MODE_RAM) {
 		if (pmem->data_offset < SZ_8K)
 			return -EINVAL;

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[4.6 stable PATCH 2/2] libnvdimm, pfn, dax: fix initialization vs autodetect for mode + alignment

[Dan Williams]

commit 1ee6667cd8d183b2fed12f97285f184431d2caf9 upstream.

The updated ndctl unit tests discovered that if a pfn configuration with
a 4K alignment is read from the namespace, that alignment will be
ignored in favor of the default 2M alignment.  The result is that the
configuration will fail initialization with a message like:

    dax6.1: bad offset: 0x22000 dax disabled align: 0x200000

Fix this by allowing the alignment read from the info block to override
the default which is 2M not 0 in the autodetect path.  This also fixes a
similar problem with the mode and alignment settings silently being
overwritten by the kernel when userspace has changed it.  We now will
either overwrite the info block if userspace changes the uuid or fail
and warn if a live setting disagrees with the info block.

Cc: <stable@vger.kernel.org>
Cc: Micah Parrish <micah.parrish@hpe.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/nvdimm/pfn_devs.c |   50 +++++++++++++++++++++++++++++++++++++--------
 drivers/nvdimm/pmem.c     |    1 -
 2 files changed, 41 insertions(+), 10 deletions(-)

diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index 58bf68c9c414..84f2372dd0bb 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -329,6 +329,8 @@ struct device *nd_pfn_create(struct nd_region *nd_region)
 int nd_pfn_validate(struct nd_pfn *nd_pfn)
 {
 	u64 checksum, offset;
+	unsigned long align;
+	enum nd_pfn_mode mode;
 	struct nd_namespace_io *nsio;
 	struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
 	struct nd_namespace_common *ndns = nd_pfn->ndns;
@@ -371,20 +373,50 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn)
 		return -ENXIO;
 	}
 
+	align = le32_to_cpu(pfn_sb->align);
+	offset = le64_to_cpu(pfn_sb->dataoff);
+	if (align == 0)
+		align = 1UL << ilog2(offset);
+	mode = le32_to_cpu(pfn_sb->mode);
+
 	if (!nd_pfn->uuid) {
-		/* from probe we allocate */
+		/*
+		 * When probing a namepace via nd_pfn_probe() the uuid
+		 * is NULL (see: nd_pfn_devinit()) we init settings from
+		 * pfn_sb
+		 */
 		nd_pfn->uuid = kmemdup(pfn_sb->uuid, 16, GFP_KERNEL);
 		if (!nd_pfn->uuid)
 			return -ENOMEM;
+		nd_pfn->align = align;
+		nd_pfn->mode = mode;
 	} else {
-		/* from init we validate */
+		/*
+		 * When probing a pfn / dax instance we validate the
+		 * live settings against the pfn_sb
+		 */
 		if (memcmp(nd_pfn->uuid, pfn_sb->uuid, 16) != 0)
 			return -ENODEV;
+
+		/*
+		 * If the uuid validates, but other settings mismatch
+		 * return EINVAL because userspace has managed to change
+		 * the configuration without specifying new
+		 * identification.
+		 */
+		if (nd_pfn->align != align || nd_pfn->mode != mode) {
+			dev_err(&nd_pfn->dev,
+					"init failed, settings mismatch\n");
+			dev_dbg(&nd_pfn->dev, "align: %lx:%lx mode: %d:%d\n",
+					nd_pfn->align, align, nd_pfn->mode,
+					mode);
+			return -EINVAL;
+		}
 	}
 
-	if (nd_pfn->align > nvdimm_namespace_capacity(ndns)) {
+	if (align > nvdimm_namespace_capacity(ndns)) {
 		dev_err(&nd_pfn->dev, "alignment: %lx exceeds capacity %llx\n",
-				nd_pfn->align, nvdimm_namespace_capacity(ndns));
+				align, nvdimm_namespace_capacity(ndns));
 		return -EINVAL;
 	}
 
@@ -394,7 +426,6 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn)
 	 * namespace has changed since the pfn superblock was
 	 * established.
 	 */
-	offset = le64_to_cpu(pfn_sb->dataoff);
 	nsio = to_nd_namespace_io(&ndns->dev);
 	if (offset >= resource_size(&nsio->res)) {
 		dev_err(&nd_pfn->dev, "pfn array size exceeds capacity of %s\n",
@@ -402,10 +433,11 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn)
 		return -EBUSY;
 	}
 
-	nd_pfn->align = le32_to_cpu(pfn_sb->align);
-	if (!is_power_of_2(offset) || offset < PAGE_SIZE) {
-		dev_err(&nd_pfn->dev, "bad offset: %#llx dax disabled\n",
-				offset);
+	if ((align && !IS_ALIGNED(offset, align))
+			|| !IS_ALIGNED(offset, PAGE_SIZE)) {
+		dev_err(&nd_pfn->dev,
+				"bad offset: %#llx dax disabled align: %#lx\n",
+				offset, align);
 		return -ENXIO;
 	}
 
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 58ad81dcd1a5..368efac7a950 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -502,7 +502,6 @@ static int __nvdimm_namespace_attach_pfn(struct nd_pfn *nd_pfn)
 	pmem = dev_get_drvdata(dev);
 	pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
 	pmem->pfn_pad = start_pad + end_trunc;
-	nd_pfn->mode = le32_to_cpu(nd_pfn->pfn_sb->mode);
 	if (nd_pfn->mode == PFN_MODE_RAM) {
 		if (pmem->data_offset < SZ_8K)
 			return -EINVAL;

Re: [4.6 stable PATCH 0/2] libnvdimm: fix initialization vs autodetect

[Greg KH]

On Wed, Aug 03, 2016 at 03:55:26PM -0700, Dan Williams wrote:
> Commit 1ee6667cd8d1 "libnvdimm, pfn, dax: fix initialization vs
> autodetect for mode + alignment" originally tagged for -stable does not
> apply cleanly to 4.6.  This backport pulls in commit 45a0dac04511
> "libnvdimm, dax: record the specified alignment of a dax-device
> instance" as a pre-requisite.
> 
> The result has been verfied to pass the ndctl unit tests.

Thanks, now queued up.

greg k-h
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Re: [4.6 stable PATCH 0/2] libnvdimm: fix initialization vs autodetect

[Greg KH]

On Wed, Aug 03, 2016 at 03:55:26PM -0700, Dan Williams wrote:
> Commit 1ee6667cd8d1 "libnvdimm, pfn, dax: fix initialization vs
> autodetect for mode + alignment" originally tagged for -stable does not
> apply cleanly to 4.6.  This backport pulls in commit 45a0dac04511
> "libnvdimm, dax: record the specified alignment of a dax-device
> instance" as a pre-requisite.
> 
> The result has been verfied to pass the ndctl unit tests.

Thanks, now queued up.

greg k-h