}
}
} else {
- rc = osd_ios_scan_one(info, dev, child->d_inode, NULL, 0);
+ /* For lustre-2.x (x <= 3), the ".lustre" has NO FID-in-LMA,
+ * so the client will get IGIF for the ".lustre" object when
+ * the MDT restart.
+ *
+ * From the OI scrub view, when the MDT upgrade to Lustre-2.4,
+ * it does not know whether there are some old clients cached
+ * the ".lustre" IGIF during the upgrading. Two choices:
+ *
+ * 1) Generate IGIF-in-LMA and IGIF-in-OI for the ".lustre".
+ * It will allow the old connected clients to access the
+ * ".lustre" with cached IGIF. But it will cause others
+ * on the MDT failed to check "fid_is_dot_lustre()".
+ *
+ * 2) Use fixed FID {FID_SEQ_DOT_LUSTRE, FID_OID_DOT_LUSTRE, 0}
+ * for ".lustre" in spite of whether there are some clients
+ * cached the ".lustre" IGIF or not. It enables the check
+ * "fid_is_dot_lustre()" on the MDT, although it will cause
+ * that the old connected clients cannot access the ".lustre"
+ * with the cached IGIF.
+ *
+ * Usually, it is rare case for the old connected clients
+ * to access the ".lustre" with cached IGIF. So we prefer
+ * to the solution 2). */
+ rc = osd_ios_scan_one(info, dev, child->d_inode,
+ &LU_DOT_LUSTRE_FID, 0);
dput(child);
}