iomap: switch iomap_zero_range to use iomap_iter

Switch iomap_zero_range to use iomap_iter.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

fs/iomap/buffered-io.c

@@ -896,11 +896,12 @@ static s64 iomap_zero(struct inode *inode, loff_t pos, u64 length,
 	return iomap_write_end(inode, pos, bytes, bytes, page, iomap, srcmap);
 }
 
-static loff_t iomap_zero_range_actor(struct inode *inode, loff_t pos,
-		loff_t length, void *data, struct iomap *iomap,
-		struct iomap *srcmap)
+static loff_t iomap_zero_iter(struct iomap_iter *iter, bool *did_zero)
 {
-	bool *did_zero = data;
+	struct iomap *iomap = &iter->iomap;
+	struct iomap *srcmap = iomap_iter_srcmap(iter);
+	loff_t pos = iter->pos;
+	loff_t length = iomap_length(iter);
 	loff_t written = 0;
 
 	/* already zeroed?  we're done. */
@@ -910,10 +911,11 @@ static loff_t iomap_zero_range_actor(struct inode *inode, loff_t pos,
 	do {
 		s64 bytes;
 
-		if (IS_DAX(inode))
+		if (IS_DAX(iter->inode))
 			bytes = dax_iomap_zero(pos, length, iomap);
 		else
-			bytes = iomap_zero(inode, pos, length, iomap, srcmap);
+			bytes = iomap_zero(iter->inode, pos, length, iomap,
+					   srcmap);
 		if (bytes < 0)
 			return bytes;
 
@@ -931,19 +933,17 @@ int
 iomap_zero_range(struct inode *inode, loff_t pos, loff_t len, bool *did_zero,
 		const struct iomap_ops *ops)
 {
-	loff_t ret;
-
-	while (len > 0) {
-		ret = iomap_apply(inode, pos, len, IOMAP_ZERO,
-				ops, did_zero, iomap_zero_range_actor);
-		if (ret <= 0)
-			return ret;
-
-		pos += ret;
-		len -= ret;
-	}
+	struct iomap_iter iter = {
+		.inode		= inode,
+		.pos		= pos,
+		.len		= len,
+		.flags		= IOMAP_ZERO,
+	};
+	int ret;
 
-	return 0;
+	while ((ret = iomap_iter(&iter, ops)) > 0)
+		iter.processed = iomap_zero_iter(&iter, did_zero);
+	return ret;
 }
 EXPORT_SYMBOL_GPL(iomap_zero_range);