Merge tag 'libnvdimm-fixes-5.2-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm fixes from Dan Williams:

 - Fix a regression that disabled device-mapper dax support

 - Remove unnecessary hardened-user-copy overhead (>30%) for dax
   read(2)/write(2).

 - Fix some compilation warnings.

* tag 'libnvdimm-fixes-5.2-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  libnvdimm/pmem: Bypass CONFIG_HARDENED_USERCOPY overhead
  dax: Arrange for dax_supported check to span multiple devices
  libnvdimm: Fix compilation warnings with W=1

4 files changed, 13 insertions, 6 deletions

diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index 7ff684159f29..2eb6a6cfe9e4 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -642,7 +642,7 @@ static struct attribute *nd_device_attributes[] = {
 	NULL,
 };
 
-/**
+/*
  * nd_device_attribute_group - generic attributes for all devices on an nd bus
  */
 struct attribute_group nd_device_attribute_group = {
@@ -671,7 +671,7 @@ static umode_t nd_numa_attr_visible(struct kobject *kobj, struct attribute *a,
 	return a->mode;
 }
 
-/**
+/*
  * nd_numa_attribute_group - NUMA attributes for all devices on an nd bus
  */
 struct attribute_group nd_numa_attribute_group = {
diff --git a/drivers/nvdimm/label.c b/drivers/nvdimm/label.c
index 2030805aa216..edf278067e72 100644
--- a/drivers/nvdimm/label.c
+++ b/drivers/nvdimm/label.c
@@ -25,6 +25,8 @@ static guid_t nvdimm_btt2_guid;
 static guid_t nvdimm_pfn_guid;
 static guid_t nvdimm_dax_guid;
 
+static const char NSINDEX_SIGNATURE[] = "NAMESPACE_INDEX\0";
+
 static u32 best_seq(u32 a, u32 b)
 {
 	a &= NSINDEX_SEQ_MASK;
diff --git a/drivers/nvdimm/label.h b/drivers/nvdimm/label.h
index e9a2ad3c2150..4bb7add39580 100644
--- a/drivers/nvdimm/label.h
+++ b/drivers/nvdimm/label.h
@@ -38,8 +38,6 @@ enum {
 	ND_NSINDEX_INIT = 0x1,
 };
 
-static const char NSINDEX_SIGNATURE[] = "NAMESPACE_INDEX\0";
-
 /**
  * struct nd_namespace_index - label set superblock
  * @sig: NAMESPACE_INDEX\0
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 0279eb1da3ef..d9d845077b8b 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -281,20 +281,27 @@ static long pmem_dax_direct_access(struct dax_device *dax_dev,
 	return __pmem_direct_access(pmem, pgoff, nr_pages, kaddr, pfn);
 }
 
+/*
+ * Use the 'no check' versions of copy_from_iter_flushcache() and
+ * copy_to_iter_mcsafe() to bypass HARDENED_USERCOPY overhead. Bounds
+ * checking, both file offset and device offset, is handled by
+ * dax_iomap_actor()
+ */
 static size_t pmem_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
 		void *addr, size_t bytes, struct iov_iter *i)
 {
-	return copy_from_iter_flushcache(addr, bytes, i);
+	return _copy_from_iter_flushcache(addr, bytes, i);
 }
 
 static size_t pmem_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff,
 		void *addr, size_t bytes, struct iov_iter *i)
 {
-	return copy_to_iter_mcsafe(addr, bytes, i);
+	return _copy_to_iter_mcsafe(addr, bytes, i);
 }
 
 static const struct dax_operations pmem_dax_ops = {
 	.direct_access = pmem_dax_direct_access,
+	.dax_supported = generic_fsdax_supported,
 	.copy_from_iter = pmem_copy_from_iter,
 	.copy_to_iter = pmem_copy_to_iter,
 };