gfs2: convert to errseq_t based writeback error reporting for fsync

Also, fix a place where a writeback error might get dropped in the
gfs2_is_jdata case.
Signed-off-by: Jeff Layton <jlayton@redhat.com>

fs/gfs2/file.c

@@ -668,12 +668,14 @@ static int gfs2_fsync(struct file *file, loff_t start, loff_t end,
 		if (ret)
 			return ret;
 		if (gfs2_is_jdata(ip))
-			filemap_write_and_wait(mapping);
+			ret = file_write_and_wait(file);
+		if (ret)
+			return ret;
 		gfs2_ail_flush(ip->i_gl, 1);
 	}
 
 	if (mapping->nrpages)
-		ret = filemap_fdatawait_range(mapping, start, end);
+		ret = file_fdatawait_range(file, start, end);
 
 	return ret ? ret : ret1;
 }