for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
                if (fs_devices->read_policy == i)
-                       ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s[%s]",
+                       ret += sysfs_emit_at(buf, ret, "%s[%s]",
                                         (ret == 0 ? "" : " "),
                                         btrfs_read_policy_name[i]);
                else
-                       ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
+                       ret += sysfs_emit_at(buf, ret, "%s%s",
                                         (ret == 0 ? "" : " "),
                                         btrfs_read_policy_name[i]);
        }
 
-       ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
+       ret += sysfs_emit_at(buf, ret, "\n");
 
        return ret;
 }