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

Pull libnvdimm fixes from Dan Williams:
 "Incremental fixes and a small feature addition on top of the main
  libnvdimm 4.12 pull request:

   - Geert noticed that tinyconfig was bloated by BLOCK selecting DAX.
     The size regression is fixed by moving all dax helpers into the
     dax-core and only specifying "select DAX" for FS_DAX and
     dax-capable drivers. He also asked for clarification of the
     NR_DEV_DAX config option which, on closer look, does not need to be
     a config option at all. Mike also throws in a DEV_DAX_PMEM fixup
     for good measure.

   - Ben's attention to detail on -stable patch submissions caught a
     case where the recent fixes to arch_copy_from_iter_pmem() missed a
     condition where we strand dirty data in the cache. This is tagged
     for -stable and will also be included in the rework of the pmem api
     to a proposed {memcpy,copy_user}_flushcache() interface for 4.13.

   - Vishal adds a feature that missed the initial pull due to pending
     review feedback. It allows the kernel to clear media errors when
     initializing a BTT (atomic sector update driver) instance on a pmem
     namespace.

   - Ross noticed that the dax_device + dax_operations conversion broke
     __dax_zero_page_range(). The nvdimm unit tests fail to check this
     path, but xfstests immediately trips over it. No excuse for missing
     this before submitting the 4.12 pull request.

  These all pass the nvdimm unit tests and an xfstests spot check. The
  set has received a build success notification from the kbuild robot"

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  filesystem-dax: fix broken __dax_zero_page_range() conversion
  libnvdimm, btt: ensure that initializing metadata clears poison
  libnvdimm: add an atomic vs process context flag to rw_bytes
  x86, pmem: Fix cache flushing for iovec write < 8 bytes
  device-dax: kill NR_DEV_DAX
  block, dax: move "select DAX" from BLOCK to FS_DAX
  device-dax: Tell kbuild DEV_DAX_PMEM depends on DEV_DAX

3 files changed, 35 insertions, 9 deletions

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index b5d1e27631ee..ab92c4ea138b 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1947,8 +1947,6 @@ extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
 extern int bdev_read_page(struct block_device *, sector_t, struct page *);
 extern int bdev_write_page(struct block_device *, sector_t, struct page *,
 						struct writeback_control *);
-extern int bdev_dax_supported(struct super_block *, int);
-int bdev_dax_pgoff(struct block_device *, sector_t, size_t, pgoff_t *pgoff);
 #else /* CONFIG_BLOCK */
 
 struct block_device;
diff --git a/include/linux/dax.h b/include/linux/dax.h
index d3158e74a59e..7fdf1d710042 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -18,12 +18,38 @@ struct dax_operations {
 			void **, pfn_t *);
 };
 
+int bdev_dax_pgoff(struct block_device *, sector_t, size_t, pgoff_t *pgoff);
+#if IS_ENABLED(CONFIG_FS_DAX)
+int __bdev_dax_supported(struct super_block *sb, int blocksize);
+static inline int bdev_dax_supported(struct super_block *sb, int blocksize)
+{
+	return __bdev_dax_supported(sb, blocksize);
+}
+#else
+static inline int bdev_dax_supported(struct super_block *sb, int blocksize)
+{
+	return -EOPNOTSUPP;
+}
+#endif
+
+#if IS_ENABLED(CONFIG_DAX)
+struct dax_device *dax_get_by_host(const char *host);
+void put_dax(struct dax_device *dax_dev);
+#else
+static inline struct dax_device *dax_get_by_host(const char *host)
+{
+	return NULL;
+}
+
+static inline void put_dax(struct dax_device *dax_dev)
+{
+}
+#endif
+
 int dax_read_lock(void);
 void dax_read_unlock(int id);
-struct dax_device *dax_get_by_host(const char *host);
 struct dax_device *alloc_dax(void *private, const char *host,
 		const struct dax_operations *ops);
-void put_dax(struct dax_device *dax_dev);
 bool dax_alive(struct dax_device *dax_dev);
 void kill_dax(struct dax_device *dax_dev);
 void *dax_get_private(struct dax_device *dax_dev);
diff --git a/include/linux/nd.h b/include/linux/nd.h
index fa66aeed441a..194b8e002ea7 100644
--- a/include/linux/nd.h
+++ b/include/linux/nd.h
@@ -48,7 +48,7 @@ struct nd_namespace_common {
 	struct device dev;
 	struct device *claim;
 	int (*rw_bytes)(struct nd_namespace_common *, resource_size_t offset,
-			void *buf, size_t size, int rw);
+			void *buf, size_t size, int rw, unsigned long flags);
 };
 
 static inline struct nd_namespace_common *to_ndns(struct device *dev)
@@ -134,9 +134,10 @@ static inline struct nd_namespace_blk *to_nd_namespace_blk(const struct device *
  * @buf is up-to-date upon return from this routine.
  */
 static inline int nvdimm_read_bytes(struct nd_namespace_common *ndns,
-		resource_size_t offset, void *buf, size_t size)
+		resource_size_t offset, void *buf, size_t size,
+		unsigned long flags)
 {
-	return ndns->rw_bytes(ndns, offset, buf, size, READ);
+	return ndns->rw_bytes(ndns, offset, buf, size, READ, flags);
 }
 
 /**
@@ -152,9 +153,10 @@ static inline int nvdimm_read_bytes(struct nd_namespace_common *ndns,
  * to media is handled internal to the @ndns driver, if at all.
  */
 static inline int nvdimm_write_bytes(struct nd_namespace_common *ndns,
-		resource_size_t offset, void *buf, size_t size)
+		resource_size_t offset, void *buf, size_t size,
+		unsigned long flags)
 {
-	return ndns->rw_bytes(ndns, offset, buf, size, WRITE);
+	return ndns->rw_bytes(ndns, offset, buf, size, WRITE, flags);
 }
 
 #define MODULE_ALIAS_ND_DEVICE(type) \