[PATCH v5 8/8] dax,iomap: Add helper dax_iomap_zero() to zero a range

[Vivek Goyal <vgoyal@redhat.com>]

Add a helper dax_ioamp_zero() to zero a range. This patch basically
merges __dax_zero_page_range() and iomap_dax_zero().

Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
---
 fs/dax.c               | 12 ++++++------
 fs/iomap/buffered-io.c |  9 +--------
 include/linux/dax.h    | 17 +++--------------
 3 files changed, 10 insertions(+), 28 deletions(-)

diff --git a/fs/dax.c b/fs/dax.c
index f8ae0a9984fa..4be581009db5 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1038,23 +1038,23 @@ static vm_fault_t dax_load_hole(struct xa_state *xas,
 	return ret;
 }
 
-int __dax_zero_page_range(struct block_device *bdev,
-		struct dax_device *dax_dev, sector_t sector,
-		unsigned int offset, unsigned int size)
+int dax_iomap_zero(loff_t pos, unsigned offset, unsigned size,
+		   struct iomap *iomap)
 {
 	pgoff_t pgoff;
 	long rc, id;
+	sector_t sector = iomap_sector(iomap, pos & PAGE_MASK);
 
-	rc = bdev_dax_pgoff(bdev, sector, PAGE_SIZE, &pgoff);
+	rc = bdev_dax_pgoff(iomap->bdev, sector, PAGE_SIZE, &pgoff);
 	if (rc)
 		return rc;
 
 	id = dax_read_lock();
-	rc = dax_zero_page_range(dax_dev, (pgoff << PAGE_SHIFT) + offset, size);
+	rc = dax_zero_page_range(iomap->dax_dev, (pgoff << PAGE_SHIFT) + offset,
+				 size);
 	dax_read_unlock(id);
 	return rc;
 }
-EXPORT_SYMBOL_GPL(__dax_zero_page_range);
 
 static loff_t
 dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 7c84c4c027c4..6f750da545e5 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -974,13 +974,6 @@ static int iomap_zero(struct inode *inode, loff_t pos, unsigned offset,
 	return iomap_write_end(inode, pos, bytes, bytes, page, iomap, srcmap);
 }
 
-static int iomap_dax_zero(loff_t pos, unsigned offset, unsigned bytes,
-		struct iomap *iomap)
-{
-	return __dax_zero_page_range(iomap->bdev, iomap->dax_dev,
-			iomap_sector(iomap, pos & PAGE_MASK), offset, bytes);
-}
-
 static loff_t
 iomap_zero_range_actor(struct inode *inode, loff_t pos, loff_t count,
 		void *data, struct iomap *iomap, struct iomap *srcmap)
@@ -1000,7 +993,7 @@ iomap_zero_range_actor(struct inode *inode, loff_t pos, loff_t count,
 		bytes = min_t(loff_t, PAGE_SIZE - offset, count);
 
 		if (IS_DAX(inode))
-			status = iomap_dax_zero(pos, offset, bytes, iomap);
+			status = dax_iomap_zero(pos, offset, bytes, iomap);
 		else
 			status = iomap_zero(inode, pos, offset, bytes, iomap,
 					srcmap);
diff --git a/include/linux/dax.h b/include/linux/dax.h
index 93a663c26d6a..7b681acfc522 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -13,6 +13,7 @@
 typedef unsigned long dax_entry_t;
 
 struct iomap_ops;
+struct iomap;
 struct dax_device;
 struct dax_operations {
 	/*
@@ -213,20 +214,8 @@ vm_fault_t dax_finish_sync_fault(struct vm_fault *vmf,
 int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
 int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
 				      pgoff_t index);
-
-#ifdef CONFIG_FS_DAX
-int __dax_zero_page_range(struct block_device *bdev,
-		struct dax_device *dax_dev, sector_t sector,
-		unsigned int offset, unsigned int length);
-#else
-static inline int __dax_zero_page_range(struct block_device *bdev,
-		struct dax_device *dax_dev, sector_t sector,
-		unsigned int offset, unsigned int length)
-{
-	return -ENXIO;
-}
-#endif
-
+int dax_iomap_zero(loff_t pos, unsigned offset, unsigned size,
+			struct iomap *iomap);
 static inline bool dax_mapping(struct address_space *mapping)
 {
 	return mapping->host && IS_DAX(mapping->host);
-- 
2.20.1