ocfs2: Use own splice write actor

We need to fill holes during a splice write. Provide our own splice write
actor which can call ocfs2_file_buffered_write() with a splice-specific
callback.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/ocfs2/aops.h b/fs/ocfs2/aops.h
index 7d94071..1b4ba53 100644
--- a/fs/ocfs2/aops.h
+++ b/fs/ocfs2/aops.h
@@ -80,6 +80,20 @@
 				  unsigned int *ret_from,
 				  unsigned int *ret_to);
 
+struct ocfs2_splice_write_priv {
+	struct splice_desc		*s_sd;
+	struct pipe_buffer		*s_buf;
+	struct pipe_inode_info		*s_pipe;
+	/* Neither offset value is ever larger than one page */
+	unsigned int			s_offset;
+	unsigned int			s_buf_offset;
+};
+int ocfs2_map_and_write_splice_data(struct inode *inode,
+				    struct ocfs2_write_ctxt *wc,
+				    u64 *p_blkno,
+				    unsigned int *ret_from,
+				    unsigned int *ret_to);
+
 /* all ocfs2_dio_end_io()'s fault */
 #define ocfs2_iocb_is_rw_locked(iocb) \
 	test_bit(0, (unsigned long *)&iocb->private)