dax,iomap: Add helper dax_iomap_zero() to zero a range

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>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20200228163456.1587-7-vgoyal@redhat.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/fs/dax.c b/fs/dax.c
index 98ba375..11b1672 100644 (file)
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1038,10 +1038,10 @@ 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)
 {
+       sector_t sector = iomap_sector(iomap, pos & PAGE_MASK);
        pgoff_t pgoff;
        long rc, id;
        void *kaddr;
@@ -1052,16 +1052,17 @@ int __dax_zero_page_range(struct block_device *bdev,
            IS_ALIGNED(size, PAGE_SIZE))
                page_aligned = true;
 
-       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();
 
        if (page_aligned)
-               rc = dax_zero_page_range(dax_dev, pgoff, size >> PAGE_SHIFT);
+               rc = dax_zero_page_range(iomap->dax_dev, pgoff,
+                                        size >> PAGE_SHIFT);
        else
-               rc = dax_direct_access(dax_dev, pgoff, 1, &kaddr, NULL);
+               rc = dax_direct_access(iomap->dax_dev, pgoff, 1, &kaddr, NULL);
        if (rc < 0) {
                dax_read_unlock(id);
                return rc;
@@ -1069,12 +1070,11 @@ int __dax_zero_page_range(struct block_device *bdev,
 
        if (!page_aligned) {
                memset(kaddr + offset, 0, size);
-               dax_flush(dax_dev, kaddr + offset, size);
+               dax_flush(iomap->dax_dev, kaddr + offset, size);
        }
        dax_read_unlock(id);
        return 0;
 }
-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 7c84c4c..6f750da 100644 (file)
--- 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 71735c4..d7af5d2 100644 (file)
--- 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 {
        /*
@@ -214,20 +215,8 @@ 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);