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LU-5099 api: transfer object type via dt_insert API
[fs/lustre-release.git] / lustre / lfsck / lfsck_layout.c
index 98e61d2..cceebbd 100644 (file)
@@ -39,7 +39,6 @@
 #include <lustre/lustre_idl.h>
 #include <lu_object.h>
 #include <dt_object.h>
-#include <lustre_linkea.h>
 #include <lustre_fid.h>
 #include <lustre_lib.h>
 #include <lustre_net.h>
@@ -492,7 +491,7 @@ static struct lfsck_rbtree_node *lfsck_rbtree_new(const struct lu_env *env,
                return ERR_PTR(-ENOMEM);
        }
 
-       rb_init_node(&lrn->lrn_node);
+       RB_CLEAR_NODE(&lrn->lrn_node);
        lrn->lrn_seq = fid_seq(fid);
        lrn->lrn_first_oid = fid_oid(fid) & ~LFSCK_RBTREE_BITMAP_MASK;
        atomic_set(&lrn->lrn_known_count, 0);
@@ -566,6 +565,9 @@ static int lfsck_rbtree_setup(const struct lu_env *env,
        llsd->llsd_rbtree_valid = 1;
        dev->dd_record_fid_accessed = 1;
 
+       CDEBUG(D_LFSCK, "%s: layout LFSCK init OST-objects accessing bitmap\n",
+              lfsck_lfsck2name(lfsck));
+
        return 0;
 }
 
@@ -596,6 +598,9 @@ static void lfsck_rbtree_cleanup(const struct lu_env *env,
                lu_object_put(env, &llsd->llsd_rb_obj->do_lu);
                llsd->llsd_rb_obj = NULL;
        }
+
+       CDEBUG(D_LFSCK, "%s: layout LFSCK fini OST-objects accessing bitmap\n",
+              lfsck_lfsck2name(lfsck));
 }
 
 static void lfsck_rbtree_update_bitmap(const struct lu_env *env,
@@ -610,9 +615,6 @@ static void lfsck_rbtree_update_bitmap(const struct lu_env *env,
        int                              rc     = 0;
        ENTRY;
 
-       CDEBUG(D_LFSCK, "%s: update bitmap for "DFID"\n",
-              lfsck_lfsck2name(com->lc_lfsck), PFID(fid));
-
        if (unlikely(!fid_is_sane(fid) || fid_is_last_id(fid)))
                RETURN_EXIT;
 
@@ -664,10 +666,12 @@ out:
        if (rc != 0 && accessed) {
                struct lfsck_layout *lo = com->lc_file_ram;
 
-               CERROR("%s: Fail to update object accessed bitmap, will cause "
-                      "incorrect LFSCK OST-object handling, so disable it to "
-                      "cancel orphan handling for related device. rc = %d.\n",
+               CDEBUG(D_LFSCK, "%s: fail to update OST-objects accessing "
+                      "bitmap, and will cause incorrect LFSCK OST-object "
+                      "handling, so disable it to cancel orphan handling "
+                      "for related device. rc = %d\n",
                       lfsck_lfsck2name(com->lc_lfsck), rc);
+
                lo->ll_flags |= LF_INCOMPLETE;
                lfsck_rbtree_cleanup(env, com);
        }
@@ -751,20 +755,20 @@ static int lfsck_layout_load(const struct lu_env *env,
        if (rc == 0) {
                return -ENOENT;
        } else if (rc < 0) {
-               CWARN("%s: failed to load lfsck_layout: rc = %d\n",
-                     lfsck_lfsck2name(com->lc_lfsck), rc);
+               CDEBUG(D_LFSCK, "%s: failed to load lfsck_layout: rc = %d\n",
+                      lfsck_lfsck2name(com->lc_lfsck), rc);
                return rc;
        } else if (rc != size) {
-               CWARN("%s: crashed lfsck_layout, to be reset: rc = %d\n",
-                     lfsck_lfsck2name(com->lc_lfsck), rc);
+               CDEBUG(D_LFSCK, "%s: lfsck_layout size %u != %u; reset it\n",
+                      lfsck_lfsck2name(com->lc_lfsck), rc, (unsigned int)size);
                return 1;
        }
 
        lfsck_layout_le_to_cpu(lo, com->lc_file_disk);
        if (lo->ll_magic != LFSCK_LAYOUT_MAGIC) {
-               CWARN("%s: invalid lfsck_layout magic %#x != %#x, "
-                     "to be reset\n", lfsck_lfsck2name(com->lc_lfsck),
-                     lo->ll_magic, LFSCK_LAYOUT_MAGIC);
+               CDEBUG(D_LFSCK, "%s: invalid lfsck_layout magic %#x != %#x, "
+                      "to be reset\n", lfsck_lfsck2name(com->lc_lfsck),
+                      lo->ll_magic, LFSCK_LAYOUT_MAGIC);
                return 1;
        }
 
@@ -785,39 +789,30 @@ static int lfsck_layout_store(const struct lu_env *env,
 
        lfsck_layout_cpu_to_le(lo, com->lc_file_ram);
        handle = dt_trans_create(env, lfsck->li_bottom);
-       if (IS_ERR(handle)) {
-               rc = PTR_ERR(handle);
-               CERROR("%s: fail to create trans for storing lfsck_layout: "
-                      "rc = %d\n", lfsck_lfsck2name(lfsck), rc);
-               RETURN(rc);
-       }
+       if (IS_ERR(handle))
+               GOTO(log, rc = PTR_ERR(handle));
 
        rc = dt_declare_record_write(env, obj, lfsck_buf_get(env, lo, size),
                                     pos, handle);
-       if (rc != 0) {
-               CERROR("%s: fail to declare trans for storing lfsck_layout(1): "
-                      "rc = %d\n", lfsck_lfsck2name(lfsck), rc);
+       if (rc != 0)
                GOTO(out, rc);
-       }
 
        rc = dt_trans_start_local(env, lfsck->li_bottom, handle);
-       if (rc != 0) {
-               CERROR("%s: fail to start trans for storing lfsck_layout: "
-                      "rc = %d\n", lfsck_lfsck2name(lfsck), rc);
+       if (rc != 0)
                GOTO(out, rc);
-       }
 
        rc = dt_record_write(env, obj, lfsck_buf_get(env, lo, size), &pos,
                             handle);
-       if (rc != 0)
-               CERROR("%s: fail to store lfsck_layout(1): size = %d, "
-                      "rc = %d\n", lfsck_lfsck2name(lfsck), (int)size, rc);
 
        GOTO(out, rc);
 
 out:
        dt_trans_stop(env, lfsck->li_bottom, handle);
 
+log:
+       if (rc != 0)
+               CDEBUG(D_LFSCK, "%s: fail to store lfsck_layout: rc = %d\n",
+                      lfsck_lfsck2name(lfsck), rc);
        return rc;
 }
 
@@ -916,9 +911,6 @@ lfsck_layout_lastid_create(const struct lu_env *env,
        int                       rc;
        ENTRY;
 
-       CDEBUG(D_LFSCK, "To create LAST_ID for <seq> "LPX64"\n",
-              fid_seq(lfsck_dto2fid(obj)));
-
        if (bk->lb_param & LPF_DRYRUN)
                return 0;
 
@@ -929,7 +921,7 @@ lfsck_layout_lastid_create(const struct lu_env *env,
 
        th = dt_trans_create(env, dt);
        if (IS_ERR(th))
-               RETURN(rc = PTR_ERR(th));
+               GOTO(log, rc = PTR_ERR(th));
 
        rc = dt_declare_create(env, obj, la, NULL, dof, th);
        if (rc != 0)
@@ -961,6 +953,11 @@ lfsck_layout_lastid_create(const struct lu_env *env,
 stop:
        dt_trans_stop(env, dt, th);
 
+log:
+       CDEBUG(D_LFSCK, "%s: layout LFSCK will create LAST_ID for <seq> "
+              LPX64": rc = %d\n",
+              lfsck_lfsck2name(lfsck), fid_seq(lfsck_dto2fid(obj)), rc);
+
        return rc;
 }
 
@@ -1041,8 +1038,9 @@ lfsck_layout_lastid_store(const struct lu_env *env,
                }
 #endif
 
-               CDEBUG(D_LFSCK, "To sync the LAST_ID for <seq> "LPX64
-                      " as <oid> "LPU64"\n", lls->lls_seq, lls->lls_lastid);
+               CDEBUG(D_LFSCK, "%s: layout LFSCK will sync the LAST_ID for "
+                      "<seq> "LPX64" as <oid> "LPU64"\n",
+                      lfsck_lfsck2name(lfsck), lls->lls_seq, lls->lls_lastid);
 
                if (bk->lb_param & LPF_DRYRUN) {
                        lls->lls_dirty = 0;
@@ -1052,7 +1050,8 @@ lfsck_layout_lastid_store(const struct lu_env *env,
                th = dt_trans_create(env, dt);
                if (IS_ERR(th)) {
                        rc1 = PTR_ERR(th);
-                       CERROR("%s: (1) failed to store "LPX64": rc = %d\n",
+                       CDEBUG(D_LFSCK, "%s: layout LFSCK failed to store "
+                              "the LAST_ID for <seq> "LPX64"(1): rc = %d\n",
                               lfsck_lfsck2name(com->lc_lfsck),
                               lls->lls_seq, rc1);
                        continue;
@@ -1082,7 +1081,8 @@ stop:
                dt_trans_stop(env, dt, th);
                if (rc != 0) {
                        rc1 = rc;
-                       CERROR("%s: (2) failed to store "LPX64": rc = %d\n",
+                       CDEBUG(D_LFSCK, "%s: layout LFSCK failed to store "
+                              "the LAST_ID for <seq> "LPX64"(2): rc = %d\n",
                               lfsck_lfsck2name(com->lc_lfsck),
                               lls->lls_seq, rc1);
                }
@@ -1170,10 +1170,16 @@ static void lfsck_layout_record_failure(const struct lu_env *env,
                                                 struct lfsck_layout *lo)
 {
        lo->ll_objs_failed_phase1++;
-       if (unlikely(lo->ll_pos_first_inconsistent == 0))
+       if (unlikely(lo->ll_pos_first_inconsistent == 0)) {
                lo->ll_pos_first_inconsistent =
                        lfsck->li_obj_oit->do_index_ops->dio_it.store(env,
                                                        lfsck->li_di_oit);
+
+               CDEBUG(D_LFSCK, "%s: layout LFSCK hit first non-repaired "
+                      "inconsistency at the pos ["LPU64"]\n",
+                      lfsck_lfsck2name(lfsck),
+                      lo->ll_pos_first_inconsistent);
+       }
 }
 
 static int lfsck_layout_master_async_interpret(const struct lu_env *env,
@@ -1192,8 +1198,9 @@ static int lfsck_layout_master_async_interpret(const struct lu_env *env,
                if (rc != 0) {
                        struct lfsck_layout *lo = com->lc_file_ram;
 
-                       CERROR("%s: fail to notify %s %x for layout start: "
-                              "rc = %d\n", lfsck_lfsck2name(com->lc_lfsck),
+                       CDEBUG(D_LFSCK, "%s: fail to notify %s %x for layout "
+                              "start: rc = %d\n",
+                              lfsck_lfsck2name(com->lc_lfsck),
                               (lr->lr_flags & LEF_TO_OST) ? "OST" : "MDT",
                               ltd->ltd_index, rc);
                        lo->ll_flags |= LF_INCOMPLETE;
@@ -1228,11 +1235,11 @@ static int lfsck_layout_master_async_interpret(const struct lu_env *env,
        case LE_PHASE2_DONE:
        case LE_PEER_EXIT:
                if (rc != 0 && rc != -EALREADY)
-                       CWARN("%s: fail to notify %s %x for layout: "
-                             "event = %d, rc = %d\n",
-                             lfsck_lfsck2name(com->lc_lfsck),
-                             (lr->lr_flags & LEF_TO_OST) ? "OST" : "MDT",
-                             ltd->ltd_index, lr->lr_event, rc);
+                       CDEBUG(D_LFSCK, "%s: fail to notify %s %x for layout: "
+                              "event = %d, rc = %d\n",
+                              lfsck_lfsck2name(com->lc_lfsck),
+                              (lr->lr_flags & LEF_TO_OST) ? "OST" : "MDT",
+                              ltd->ltd_index, lr->lr_event, rc);
                break;
        case LE_QUERY: {
                struct lfsck_reply *reply;
@@ -1249,7 +1256,7 @@ static int lfsck_layout_master_async_interpret(const struct lu_env *env,
                                               &RMF_LFSCK_REPLY);
                if (reply == NULL) {
                        rc = -EPROTO;
-                       CERROR("%s: invalid return value: rc = %d\n",
+                       CDEBUG(D_LFSCK, "%s:  invalid query reply: rc = %d\n",
                               lfsck_lfsck2name(com->lc_lfsck), rc);
                        spin_lock(&ltds->ltd_lock);
                        list_del_init(&ltd->ltd_layout_phase_list);
@@ -1287,7 +1294,7 @@ static int lfsck_layout_master_async_interpret(const struct lu_env *env,
                break;
        }
        default:
-               CERROR("%s: unexpected event: rc = %d\n",
+               CDEBUG(D_LFSCK, "%s: layout LFSCK unexpected event: rc = %d\n",
                       lfsck_lfsck2name(com->lc_lfsck), lr->lr_event);
                break;
        }
@@ -1324,7 +1331,7 @@ static int lfsck_layout_master_query_others(const struct lu_env *env,
        memset(lr, 0, sizeof(*lr));
        lr->lr_index = lfsck_dev_idx(lfsck->li_bottom);
        lr->lr_event = LE_QUERY;
-       lr->lr_active = LT_LAYOUT;
+       lr->lr_active = LFSCK_TYPE_LAYOUT;
        laia->laia_com = com;
        laia->laia_lr = lr;
        laia->laia_shared = 0;
@@ -1360,8 +1367,8 @@ again:
                                         lfsck_layout_master_async_interpret,
                                         laia, LFSCK_QUERY);
                if (rc != 0) {
-                       CERROR("%s: fail to query %s %x for layout: rc = %d\n",
-                              lfsck_lfsck2name(lfsck),
+                       CDEBUG(D_LFSCK, "%s: layout LFSCK fail to query %s %x: "
+                              "rc = %d\n", lfsck_lfsck2name(lfsck),
                               (lr->lr_flags & LEF_TO_OST) ? "OST" : "MDT",
                               ltd->ltd_index, rc);
                        lfsck_tgt_put(ltd);
@@ -1418,7 +1425,7 @@ static int lfsck_layout_master_notify_others(const struct lu_env *env,
                RETURN(-ENOMEM);
 
        lr->lr_index = lfsck_dev_idx(lfsck->li_bottom);
-       lr->lr_active = LT_LAYOUT;
+       lr->lr_active = LFSCK_TYPE_LAYOUT;
        laia->laia_com = com;
        laia->laia_lr = lr;
        laia->laia_shared = 0;
@@ -1438,8 +1445,8 @@ static int lfsck_layout_master_notify_others(const struct lu_env *env,
                                        lfsck_layout_master_async_interpret,
                                        laia, LFSCK_NOTIFY);
                        if (rc != 0) {
-                               CERROR("%s: fail to notify %s %x for layout "
-                                      "start: rc = %d\n",
+                               CDEBUG(D_LFSCK, "%s: layout LFSCK fail to "
+                                      "notify %s %x for start: rc = %d\n",
                                       lfsck_lfsck2name(lfsck),
                                       (lr->lr_flags & LEF_TO_OST) ? "OST" :
                                       "MDT", idx, rc);
@@ -1460,6 +1467,7 @@ static int lfsck_layout_master_notify_others(const struct lu_env *env,
                        break;
 
                /* link other MDT targets locallly. */
+               ltds = &lfsck->li_mdt_descs;
                spin_lock(&ltds->ltd_lock);
                cfs_foreach_bit(ltds->ltd_tgts_bitmap, idx) {
                        ltd = LTD_TGT(ltds, idx);
@@ -1520,8 +1528,9 @@ again:
                                        lfsck_layout_master_async_interpret,
                                        laia, LFSCK_NOTIFY);
                        if (rc != 0) {
-                               CERROR("%s: fail to notify %s %x for layout "
-                                      "stop/phase2: rc = %d\n",
+                               CDEBUG(D_LFSCK, "%s: layout LFSCK fail to "
+                                      "notify %s %x for stop/phase2_done/"
+                                      "peer_exit: rc = %d\n",
                                       lfsck_lfsck2name(lfsck),
                                       (lr->lr_flags & LEF_TO_OST) ? "OST" :
                                       "MDT", ltd->ltd_index, rc);
@@ -1568,9 +1577,9 @@ again:
                                        lfsck_layout_master_async_interpret,
                                        laia, LFSCK_NOTIFY);
                        if (rc != 0) {
-                               CERROR("%s: fail to notify MDT %x for layout "
-                                      "phase1 done: rc = %d\n",
-                                      lfsck_lfsck2name(lfsck),
+                               CDEBUG(D_LFSCK, "%s: layout LFSCK fail to "
+                                      "notify MDT %x for phase1_done: "
+                                      "rc = %d\n", lfsck_lfsck2name(lfsck),
                                       ltd->ltd_index, rc);
                                lfsck_tgt_put(ltd);
                        }
@@ -1579,7 +1588,7 @@ again:
                spin_unlock(&ltds->ltd_lock);
                break;
        default:
-               CERROR("%s: unexpected LFSCK event: rc = %d\n",
+               CDEBUG(D_LFSCK, "%s: layout LFSCK unexpected event: rc = %d\n",
                       lfsck_lfsck2name(lfsck), lr->lr_event);
                rc = -EINVAL;
                break;
@@ -1791,6 +1800,7 @@ static int lfsck_layout_extend_lovea(const struct lu_env *env,
        struct lov_ost_data_v1  *objs;
        int                      rc;
        __u16                    count;
+       bool                     hole   = false;
        ENTRY;
 
        if (fl == LU_XATTR_CREATE || reset) {
@@ -1799,8 +1809,10 @@ static int lfsck_layout_extend_lovea(const struct lu_env *env,
                count = ea_off + 1;
                LASSERT(buf->lb_len == lov_mds_md_size(count, LOV_MAGIC_V1));
 
-               if (ea_off != 0 || reset)
+               if (ea_off != 0 || reset) {
                        pattern |= LOV_PATTERN_F_HOLE;
+                       hole = true;
+               }
 
                memset(lmm, 0, buf->lb_len);
                lmm->lmm_magic = cpu_to_le32(LOV_MAGIC_V1);
@@ -1833,6 +1845,7 @@ static int lfsck_layout_extend_lovea(const struct lu_env *env,
                if (gap > 0) {
                        memset(objs, 0, gap * sizeof(*objs));
                        lmm->lmm_pattern |= cpu_to_le32(LOV_PATTERN_F_HOLE);
+                       hole = true;
                }
 
                lmm->lmm_layout_gen =
@@ -1844,6 +1857,13 @@ static int lfsck_layout_extend_lovea(const struct lu_env *env,
        rc = lfsck_layout_refill_lovea(env, handle, parent, cfid, buf, objs,
                                       fl, ost_idx);
 
+       CDEBUG(D_LFSCK, "%s: layout LFSCK assistant extend layout EA for "
+              DFID": parent "DFID", OST-index %u, stripe-index %u, fl %d, "
+              "reset %s, %s LOV EA hole: rc = %d\n",
+              lfsck_lfsck2name(lfsck), PFID(cfid), PFID(lfsck_dto2fid(parent)),
+              ost_idx, ea_off, fl, reset ? "yes" : "no",
+              hole ? "with" : "without", rc);
+
        RETURN(rc);
 }
 
@@ -1905,20 +1925,61 @@ out:
 }
 
 /**
- * \retval      +1: repaired
- * \retval       0: did nothing
- * \retval     -ve: on error
+ * This function will create the MDT-object with the given (partial) LOV EA.
+ *
+ * Under some data corruption cases, the MDT-object of the file may be lost,
+ * but its OST-objects, or some of them are there. The layout LFSCK needs to
+ * re-create the MDT-object with the orphan OST-object(s) information.
+ *
+ * On the other hand, the LFSCK may has created some OST-object for repairing
+ * dangling LOV EA reference, but as the LFSCK processing, it may find that
+ * the old OST-object is there and should replace the former new created OST
+ * object. Unfortunately, some others have modified such newly created object.
+ * To keep the data (both new and old), the LFSCK will create MDT-object with
+ * new FID to reference the original OST-object.
+ *
+ * \param[in] env      pointer to the thread context
+ * \param[in] com      pointer to the lfsck component
+ * \param[in] ltd      pointer to target device descriptor
+ * \param[in] rec      pointer to the record for the orphan OST-object
+ * \param[in] cfid     pointer to FID for the orphan OST-object
+ * \param[in] infix    additional information, such as the FID for original
+ *                     MDT-object and the stripe offset in the LOV EA
+ * \param[in] type     the type for describing why the orphan MDT-object is
+ *                     created. The rules are as following:
+ *
+ *  type "C":          Multiple OST-objects claim the same MDT-object and the
+ *                     same slot in the layout EA. Then the LFSCK will create
+ *                     new MDT-object(s) to hold the conflict OST-object(s).
+ *
+ *  type "N":          The orphan OST-object does not know which one was the
+ *                     real parent MDT-object, so the LFSCK uses new FID for
+ *                     its parent MDT-object.
+ *
+ *  type "R":          The orphan OST-object knows its parent MDT-object FID,
+ *                     but does not know the position (the file name) in the
+ *                     namespace.
+ *
+ * The orphan name will be like:
+ * ${FID}-${infix}-${type}-${conflict_version}
+ *
+ * \param[in] ea_off   the stripe offset in the LOV EA
+ *
+ * \retval             positive on repaired something
+ * \retval             0 if needs to repair nothing
+ * \retval             negative error number on failure
  */
 static int lfsck_layout_recreate_parent(const struct lu_env *env,
                                        struct lfsck_component *com,
                                        struct lfsck_tgt_desc *ltd,
                                        struct lu_orphan_rec *rec,
                                        struct lu_fid *cfid,
-                                       const char *prefix,
-                                       const char *postfix,
+                                       const char *infix,
+                                       const char *type,
                                        __u32 ea_off)
 {
        struct lfsck_thread_info        *info   = lfsck_env_info(env);
+       struct dt_insert_rec            *dtrec  = &info->lti_dt_rec;
        char                            *name   = info->lti_key;
        struct lu_attr                  *la     = &info->lti_la;
        struct dt_object_format         *dof    = &info->lti_dof;
@@ -1932,6 +1993,9 @@ static int lfsck_layout_recreate_parent(const struct lu_env *env,
        struct lu_buf                   *pbuf   = NULL;
        struct lu_buf                   *ea_buf = &info->lti_big_buf;
        struct lustre_handle             lh     = { 0 };
+       struct linkea_data               ldata  = { 0 };
+       struct lu_buf                    linkea_buf;
+       const struct lu_name            *pname;
        int                              buflen = ea_buf->lb_len;
        int                              idx    = 0;
        int                              rc     = 0;
@@ -1941,7 +2005,7 @@ static int lfsck_layout_recreate_parent(const struct lu_env *env,
        if (unlikely(lfsck->li_lpf_obj == NULL)) {
                rc = lfsck_create_lpf(env, lfsck);
                if (rc != 0)
-                       RETURN(rc);
+                       GOTO(log, rc);
        }
 
        if (fid_is_zero(pfid)) {
@@ -1960,53 +2024,35 @@ static int lfsck_layout_recreate_parent(const struct lu_env *env,
                pbuf = lfsck_buf_get(env, ff, sizeof(struct filter_fid));
                cobj = lfsck_object_find_by_dev(env, ltd->ltd_tgt, cfid);
                if (IS_ERR(cobj))
-                       RETURN(PTR_ERR(cobj));
+                       GOTO(log, rc = PTR_ERR(cobj));
        }
 
-       CDEBUG(D_LFSCK, "Re-create the lost MDT-object: parent "
-              DFID", child "DFID", OST-index %u, stripe-index %u, "
-              "prefix %s, postfix %s\n",
-              PFID(pfid), PFID(cfid), ltd->ltd_index, ea_off, prefix, postfix);
-
        pobj = lfsck_object_find_by_dev(env, lfsck->li_bottom, pfid);
        if (IS_ERR(pobj))
                GOTO(put, rc = PTR_ERR(pobj));
 
-       LASSERT(prefix != NULL);
-       LASSERT(postfix != NULL);
+       LASSERT(infix != NULL);
+       LASSERT(type != NULL);
 
-       /** name rules:
-        *
-        *  1. Use the MDT-object's FID as the name with prefix and postfix.
-        *
-        *  1.1 prefix "C-":    More than one OST-objects claim the same
-        *                      MDT-object and the same slot in the layout EA.
-        *                      It may be created for dangling referenced MDT
-        *                      object or may be not.
-        *  1.2 prefix "N-":    The orphan OST-object does not know which one
-        *                      is the real parent, so the LFSCK assign a new
-        *                      FID as its parent.
-        *  1.3 prefix "R-":    The orphan OST-object know its parent FID but
-        *                      does not know the position in the namespace.
-        *
-        *  2. If there is name conflict, append more index for new name. */
-       sprintf(name, "%s"DFID"%s", prefix, PFID(pfid), postfix);
        do {
+               snprintf(name, NAME_MAX, DFID"%s-%s-%d", PFID(pfid), infix,
+                        type, idx++);
                rc = dt_lookup(env, lfsck->li_lpf_obj, (struct dt_rec *)tfid,
                               (const struct dt_key *)name, BYPASS_CAPA);
                if (rc != 0 && rc != -ENOENT)
                        GOTO(put, rc);
-
-               if (unlikely(rc == 0)) {
-                       CWARN("%s: The name %s under lost+found has been used "
-                             "by the "DFID". Try to increase the FID version "
-                             "for the new file name.\n",
-                             lfsck_lfsck2name(lfsck), name, PFID(tfid));
-                       sprintf(name, "%s"DFID"%s-%d", prefix, PFID(pfid),
-                               postfix, ++idx);
-               }
        } while (rc == 0);
 
+       rc = linkea_data_new(&ldata,
+                            &lfsck_env_info(env)->lti_linkea_buf);
+       if (rc != 0)
+               GOTO(put, rc);
+
+       pname = lfsck_name_get_const(env, name, strlen(name));
+       rc = linkea_add_buf(&ldata, pname, lfsck_dto2fid(lfsck->li_lpf_obj));
+       if (rc != 0)
+               GOTO(put, rc);
+
        memset(la, 0, sizeof(*la));
        la->la_uid = rec->lor_uid;
        la->la_gid = rec->lor_gid;
@@ -2063,12 +2109,22 @@ static int lfsck_layout_recreate_parent(const struct lu_env *env,
                GOTO(stop, rc);
 
        /* 4a. Insert the MDT-object to .lustre/lost+found/MDTxxxx/ */
+       dtrec->rec_fid = pfid;
+       dtrec->rec_type = S_IFREG;
        rc = dt_declare_insert(env, lfsck->li_lpf_obj,
-                              (const struct dt_rec *)pfid,
+                              (const struct dt_rec *)dtrec,
                               (const struct dt_key *)name, th);
        if (rc != 0)
                GOTO(stop, rc);
 
+       /* 5a. insert linkEA for parent. */
+       linkea_buf.lb_buf = ldata.ld_buf->lb_buf;
+       linkea_buf.lb_len = ldata.ld_leh->leh_len;
+       rc = dt_declare_xattr_set(env, pobj, &linkea_buf,
+                                 XATTR_NAME_LINK, 0, th);
+       if (rc != 0)
+               GOTO(stop, rc);
+
        rc = dt_trans_start(env, next, th);
        if (rc != 0)
                GOTO(stop, rc);
@@ -2094,9 +2150,14 @@ static int lfsck_layout_recreate_parent(const struct lu_env *env,
                GOTO(stop, rc);
 
        /* 4b. Insert the MDT-object to .lustre/lost+found/MDTxxxx/ */
-       rc = dt_insert(env, lfsck->li_lpf_obj,
-                      (const struct dt_rec *)pfid,
+       rc = dt_insert(env, lfsck->li_lpf_obj, (const struct dt_rec *)dtrec,
                       (const struct dt_key *)name, th, BYPASS_CAPA, 1);
+       if (rc != 0)
+               GOTO(stop, rc);
+
+       /* 5b. insert linkEA for parent. */
+       rc = dt_xattr_set(env, pobj, &linkea_buf,
+                         XATTR_NAME_LINK, 0, th, BYPASS_CAPA);
 
        GOTO(stop, rc);
 
@@ -2113,6 +2174,15 @@ put:
                lu_object_put(env, &pobj->do_lu);
        ea_buf->lb_len = buflen;
 
+log:
+       if (rc < 0)
+               CDEBUG(D_LFSCK, "%s layout LFSCK assistant failed to "
+                      "recreate the lost MDT-object: parent "DFID
+                      ", child "DFID", OST-index %u, stripe-index %u, "
+                      "infix %s, type %s: rc = %d\n",
+                      lfsck_lfsck2name(lfsck), PFID(pfid), PFID(cfid),
+                      ltd->ltd_index, ea_off, infix, type, rc);
+
        return rc >= 0 ? 1 : rc;
 }
 
@@ -2152,7 +2222,7 @@ static int lfsck_layout_master_conditional_destroy(const struct lu_env *env,
 
        memset(lr, 0, sizeof(*lr));
        lr->lr_event = LE_CONDITIONAL_DESTROY;
-       lr->lr_active = LT_LAYOUT;
+       lr->lr_active = LFSCK_TYPE_LAYOUT;
        lr->lr_fid = *fid;
 
        tmp = req_capsule_client_get(&req->rq_pill, &RMF_LFSCK_REQUEST);
@@ -2252,10 +2322,11 @@ static int lfsck_layout_slave_conditional_destroy(const struct lu_env *env,
 
        rc = dt_destroy(env, obj, th);
        if (rc == 0)
-               CDEBUG(D_LFSCK, "Destroy the empty OST-object "DFID" which "
-                      "was created for reparing dangling referenced case. "
-                      "But the original missed OST-object is found now.\n",
-                      PFID(fid));
+               CDEBUG(D_LFSCK, "%s: layout LFSCK destroyed the empty "
+                      "OST-object "DFID" that was created for reparing "
+                      "dangling referenced case. But the original missed "
+                      "OST-object is found now.\n",
+                      lfsck_lfsck2name(lfsck), PFID(fid));
 
        GOTO(stop, rc);
 
@@ -2298,7 +2369,7 @@ static int lfsck_layout_conflict_create(const struct lu_env *env,
        struct lfsck_thread_info *info          = lfsck_env_info(env);
        struct lu_fid            *cfid2         = &info->lti_fid2;
        struct ost_id            *oi            = &info->lti_oi;
-       char                     *postfix       = info->lti_tmpbuf;
+       char                     *infix         = info->lti_tmpbuf;
        struct lov_mds_md_v1     *lmm           = ea_buf->lb_buf;
        struct dt_device         *dev           = com->lc_lfsck->li_bottom;
        struct thandle           *th            = NULL;
@@ -2310,12 +2381,6 @@ static int lfsck_layout_conflict_create(const struct lu_env *env,
        ostid_le_to_cpu(&slot->l_ost_oi, oi);
        ostid_to_fid(cfid2, oi, ost_idx2);
 
-       CDEBUG(D_LFSCK, "Handle layout EA conflict: parent "DFID
-              ", cur-child "DFID" on the OST %u, orphan-child "
-              DFID" on the OST %u, stripe-index %u\n",
-              PFID(lfsck_dto2fid(parent)), PFID(cfid2), ost_idx2,
-              PFID(cfid), ltd->ltd_index, ea_off);
-
        /* Hold layout lock on the parent to prevent others to access. */
        rc = lfsck_layout_lock(env, com, parent, &lh,
                               MDS_INODELOCK_LAYOUT | MDS_INODELOCK_XATTR);
@@ -2334,10 +2399,10 @@ static int lfsck_layout_conflict_create(const struct lu_env *env,
                ea_buf->lb_len = ori_len;
 
                fid_zero(&rec->lor_fid);
-               snprintf(postfix, LFSCK_TMPBUF_LEN, "-"DFID"-%x",
+               snprintf(infix, LFSCK_TMPBUF_LEN, "-"DFID"-%x",
                         PFID(lu_object_fid(&parent->do_lu)), ea_off);
                rc = lfsck_layout_recreate_parent(env, com, ltd, rec, cfid,
-                                                 "C-", postfix, ea_off);
+                                                 infix, "C", ea_off);
 
                RETURN(rc);
        }
@@ -2375,6 +2440,13 @@ unlock:
 out:
        ea_buf->lb_len = ori_len;
 
+       CDEBUG(D_LFSCK, "%s: layout LFSCK assistant replaced the conflict "
+              "OST-object "DFID" on the OST %x with the orphan "DFID" on "
+              "the OST %x: parent "DFID", stripe-index %u: rc = %d\n",
+              lfsck_lfsck2name(com->lc_lfsck), PFID(cfid2), ost_idx2,
+              PFID(cfid), ltd->ltd_index, PFID(lfsck_dto2fid(parent)),
+              ea_off, rc);
+
        return rc >= 0 ? 1 : rc;
 }
 
@@ -2412,14 +2484,17 @@ static int lfsck_layout_recreate_lovea(const struct lu_env *env,
        bool                      locked        = false;
        ENTRY;
 
-       CDEBUG(D_LFSCK, "Re-create the crashed layout EA: parent "
-              DFID", child "DFID", OST-index %u, stripe-index %u\n",
-              PFID(lfsck_dto2fid(parent)), PFID(cfid), ost_idx, ea_off);
-
        rc = lfsck_layout_lock(env, com, parent, &lh,
                               MDS_INODELOCK_LAYOUT | MDS_INODELOCK_XATTR);
-       if (rc != 0)
+       if (rc != 0) {
+               CDEBUG(D_LFSCK, "%s: layout LFSCK assistant failed to recreate "
+                      "LOV EA for "DFID": parent "DFID", OST-index %u, "
+                      "stripe-index %u: rc = %d\n",
+                      lfsck_lfsck2name(lfsck), PFID(cfid),
+                      PFID(lfsck_dto2fid(parent)), ost_idx, ea_off, rc);
+
                RETURN(rc);
+       }
 
 again:
        if (locked) {
@@ -2567,6 +2642,13 @@ again:
                        rc = lfsck_layout_refill_lovea(env, handle, parent,
                                                       cfid, buf, objs, fl,
                                                       ost_idx);
+
+                       CDEBUG(D_LFSCK, "%s layout LFSCK assistant fill "
+                              "dummy layout slot for "DFID": parent "DFID
+                              ", OST-index %u, stripe-index %u: rc = %d\n",
+                              lfsck_lfsck2name(lfsck), PFID(cfid),
+                              PFID(lfsck_dto2fid(parent)), ost_idx, i, rc);
+
                        GOTO(unlock_parent, rc);
                }
 
@@ -2592,6 +2674,14 @@ again:
                                rc = lfsck_layout_update_pfid(env, com, parent,
                                                        cfid, ltd->ltd_tgt, i);
 
+                               CDEBUG(D_LFSCK, "%s layout LFSCK assistant "
+                                      "updated OST-object's pfid for "DFID
+                                      ": parent "DFID", OST-index %u, "
+                                      "stripe-index %u: rc = %d\n",
+                                      lfsck_lfsck2name(lfsck), PFID(cfid),
+                                      PFID(lfsck_dto2fid(parent)),
+                                      ltd->ltd_index, i, rc);
+
                                RETURN(rc);
                        }
                }
@@ -2648,7 +2738,7 @@ static int lfsck_layout_scan_orphan_one(const struct lu_env *env,
 
        if (fid_is_zero(pfid)) {
                rc = lfsck_layout_recreate_parent(env, com, ltd, rec, cfid,
-                                                 "N-", "", ea_off);
+                                                 "", "N", ea_off);
                GOTO(out, rc);
        }
 
@@ -2666,7 +2756,7 @@ static int lfsck_layout_scan_orphan_one(const struct lu_env *env,
        if (dt_object_exists(parent) == 0) {
                lu_object_put(env, &parent->do_lu);
                rc = lfsck_layout_recreate_parent(env, com, ltd, rec, cfid,
-                                                 "R-", "", ea_off);
+                                                 "", "R", ea_off);
                GOTO(out, rc);
        }
 
@@ -2716,7 +2806,8 @@ static int lfsck_layout_scan_orphan(const struct lu_env *env,
        int                              rc     = 0;
        ENTRY;
 
-       CDEBUG(D_LFSCK, "%s: start the orphan scanning for OST%04x\n",
+       CDEBUG(D_LFSCK, "%s: layout LFSCK assistant starts the orphan "
+              "scanning for OST%04x\n",
               lfsck_lfsck2name(lfsck), ltd->ltd_index);
 
        ostid_set_seq(oi, FID_SEQ_IDIF);
@@ -2724,7 +2815,7 @@ static int lfsck_layout_scan_orphan(const struct lu_env *env,
        ostid_to_fid(fid, oi, ltd->ltd_index);
        obj = lfsck_object_find_by_dev(env, ltd->ltd_tgt, fid);
        if (unlikely(IS_ERR(obj)))
-               RETURN(PTR_ERR(obj));
+               GOTO(log, rc = PTR_ERR(obj));
 
        rc = obj->do_ops->do_index_try(env, obj, &dt_lfsck_orphan_features);
        if (rc != 0)
@@ -2793,7 +2884,9 @@ fini:
 put:
        lu_object_put(env, &obj->do_lu);
 
-       CDEBUG(D_LFSCK, "%s: finish the orphan scanning for OST%04x, rc = %d\n",
+log:
+       CDEBUG(D_LFSCK, "%s: layout LFSCK assistant finished the orphan "
+              "scanning for OST%04x: rc = %d\n",
               lfsck_lfsck2name(lfsck), ltd->ltd_index, rc);
 
        return rc > 0 ? 0 : rc;
@@ -2833,15 +2926,8 @@ static int lfsck_layout_repair_dangling(const struct lu_env *env,
        else
                create = false;
 
-       CDEBUG(D_LFSCK, "Found dangling reference for: parent "DFID
-              ", child "DFID", OST-index %u, stripe-index %u, owner %u:%u. %s",
-              PFID(lfsck_dto2fid(parent)), PFID(lfsck_dto2fid(child)),
-              llr->llr_ost_idx, llr->llr_lov_idx, pla->la_uid, pla->la_gid,
-              create ? "Create the lost OST-object as required.\n" :
-                       "Keep the MDT-object there by default.\n");
-
        if (!create)
-               RETURN(1);
+               GOTO(log, rc = 1);
 
        memset(cla, 0, sizeof(*cla));
        cla->la_uid = pla->la_uid;
@@ -2853,7 +2939,7 @@ static int lfsck_layout_repair_dangling(const struct lu_env *env,
        rc = lfsck_layout_lock(env, com, parent, &lh,
                               MDS_INODELOCK_LAYOUT | MDS_INODELOCK_XATTR);
        if (rc != 0)
-               RETURN(rc);
+               GOTO(log, rc);
 
        handle = dt_trans_create(env, dev);
        if (IS_ERR(handle))
@@ -2904,6 +2990,16 @@ stop:
 unlock1:
        lfsck_layout_unlock(&lh);
 
+log:
+       CDEBUG(D_LFSCK, "%s: layout LFSCK assistant found dangling "
+              "reference for: parent "DFID", child "DFID", OST-index %u, "
+              "stripe-index %u, owner %u/%u. %s: rc = %d\n",
+              lfsck_lfsck2name(com->lc_lfsck), PFID(lfsck_dto2fid(parent)),
+              PFID(lfsck_dto2fid(child)), llr->llr_ost_idx,
+              llr->llr_lov_idx, pla->la_uid, pla->la_gid,
+              create ? "Create the lost OST-object as required" :
+                       "Keep the MDT-object there by default", rc);
+
        return rc;
 }
 
@@ -2928,15 +3024,10 @@ static int lfsck_layout_repair_unmatched_pair(const struct lu_env *env,
        int                              rc;
        ENTRY;
 
-       CDEBUG(D_LFSCK, "Repair unmatched MDT-OST pair for: parent "DFID
-              ", child "DFID", OST-index %u, stripe-index %u, owner %u:%u\n",
-              PFID(lfsck_dto2fid(parent)), PFID(lfsck_dto2fid(child)),
-              llr->llr_ost_idx, llr->llr_lov_idx, pla->la_uid, pla->la_gid);
-
        rc = lfsck_layout_lock(env, com, parent, &lh,
                               MDS_INODELOCK_LAYOUT | MDS_INODELOCK_XATTR);
        if (rc != 0)
-               RETURN(rc);
+               GOTO(log, rc);
 
        handle = dt_trans_create(env, dev);
        if (IS_ERR(handle))
@@ -2993,6 +3084,14 @@ stop:
 unlock1:
        lfsck_layout_unlock(&lh);
 
+log:
+       CDEBUG(D_LFSCK, "%s: layout LFSCK assistant repaired unmatched "
+              "MDT-OST pair for: parent "DFID", child "DFID", OST-index %u, "
+              "stripe-index %u, owner %u/%u: rc = %d\n",
+              lfsck_lfsck2name(com->lc_lfsck), PFID(lfsck_dto2fid(parent)),
+              PFID(lfsck_dto2fid(child)), llr->llr_ost_idx, llr->llr_lov_idx,
+              pla->la_uid, pla->la_gid, rc);
+
        return rc;
 }
 
@@ -3023,15 +3122,10 @@ static int lfsck_layout_repair_multiple_references(const struct lu_env *env,
        int                              rc;
        ENTRY;
 
-       CDEBUG(D_LFSCK, "Repair multiple references for: parent "DFID
-              ", OST-index %u, stripe-index %u, owner %u:%u\n",
-              PFID(lfsck_dto2fid(parent)), llr->llr_ost_idx,
-              llr->llr_lov_idx, la->la_uid, la->la_gid);
-
        rc = lfsck_layout_lock(env, com, parent, &lh,
                               MDS_INODELOCK_LAYOUT | MDS_INODELOCK_XATTR);
        if (rc != 0)
-               RETURN(rc);
+               GOTO(log, rc);
 
        handle = dt_trans_create(env, pdev);
        if (IS_ERR(handle))
@@ -3115,6 +3209,13 @@ stop:
 unlock1:
        lfsck_layout_unlock(&lh);
 
+log:
+       CDEBUG(D_LFSCK, "%s: layout LFSCK assistant repaired multiple "
+              "references for: parent "DFID", OST-index %u, stripe-index %u, "
+              "owner %u/%u: rc = %d\n",
+              lfsck_lfsck2name(com->lc_lfsck), PFID(lfsck_dto2fid(parent)),
+              llr->llr_ost_idx, llr->llr_lov_idx, la->la_uid, la->la_gid, rc);
+
        return rc;
 }
 
@@ -3136,14 +3237,9 @@ static int lfsck_layout_repair_owner(const struct lu_env *env,
        int                              rc;
        ENTRY;
 
-       CDEBUG(D_LFSCK, "Repair inconsistent file owner for: parent "DFID
-              ", child "DFID", OST-index %u, stripe-index %u, owner %u:%u\n",
-              PFID(lfsck_dto2fid(parent)), PFID(lfsck_dto2fid(child)),
-              llr->llr_ost_idx, llr->llr_lov_idx, pla->la_uid, pla->la_gid);
-
        handle = dt_trans_create(env, dev);
        if (IS_ERR(handle))
-               RETURN(PTR_ERR(handle));
+               GOTO(log, rc = PTR_ERR(handle));
 
        tla->la_uid = pla->la_uid;
        tla->la_gid = pla->la_gid;
@@ -3163,14 +3259,8 @@ static int lfsck_layout_repair_owner(const struct lu_env *env,
 
        /* Get the latest parent's owner. */
        rc = dt_attr_get(env, parent, tla, BYPASS_CAPA);
-       if (rc != 0) {
-               CWARN("%s: fail to get the latest parent's ("DFID") owner, "
-                     "not sure whether some others chown/chgrp during the "
-                     "LFSCK: rc = %d\n", lfsck_lfsck2name(com->lc_lfsck),
-                     PFID(lfsck_dto2fid(parent)), rc);
-
+       if (rc != 0)
                GOTO(unlock, rc);
-       }
 
        /* Some others chown/chgrp during the LFSCK, needs to do nothing. */
        if (unlikely(tla->la_uid != pla->la_uid ||
@@ -3188,6 +3278,14 @@ unlock:
 stop:
        rc = lfsck_layout_trans_stop(env, dev, handle, rc);
 
+log:
+       CDEBUG(D_LFSCK, "%s: layout LFSCK assistant repaired inconsistent "
+              "file owner for: parent "DFID", child "DFID", OST-index %u, "
+              "stripe-index %u, owner %u/%u: rc = %d\n",
+              lfsck_lfsck2name(com->lc_lfsck), PFID(lfsck_dto2fid(parent)),
+              PFID(lfsck_dto2fid(child)), llr->llr_ost_idx, llr->llr_lov_idx,
+              pla->la_uid, pla->la_gid, rc);
+
        return rc;
 }
 
@@ -3412,7 +3510,8 @@ out:
                           rc == -EHOSTUNREACH) {
                        /* If cannot touch the target server,
                         * mark the LFSCK as INCOMPLETE. */
-                       CERROR("%s: Fail to talk with OST %x: rc = %d.\n",
+                       CDEBUG(D_LFSCK, "%s: layout LFSCK assistant fail to "
+                              "talk with OST %x: rc = %d\n",
                               lfsck_lfsck2name(lfsck), llr->llr_ost_idx, rc);
                        lo->ll_flags |= LF_INCOMPLETE;
                        lo->ll_objs_skipped++;
@@ -3469,7 +3568,8 @@ static int lfsck_layout_assistant(void *args)
 
        rc = lfsck_layout_master_notify_others(env, com, lr);
        if (rc != 0) {
-               CERROR("%s: fail to notify others for layout start: rc = %d\n",
+               CDEBUG(D_LFSCK, "%s: layout LFSCK assistant failed to notify "
+                      "others for LFSCK start: rc = %d\n",
                       lfsck_lfsck2name(lfsck), rc);
                GOTO(fini, rc);
        }
@@ -3538,8 +3638,9 @@ static int lfsck_layout_assistant(void *args)
                        lr->lr_status = llmd->llmd_post_result;
                        rc = lfsck_layout_master_notify_others(env, com, lr);
                        if (rc != 0)
-                               CERROR("%s: failed to notify others "
-                                      "for layout post: rc = %d\n",
+                               CDEBUG(D_LFSCK, "%s: layout LFSCK assistant "
+                                      "failed to notify others for LFSCK "
+                                      "post: rc = %d\n",
                                       lfsck_lfsck2name(lfsck), rc);
 
                        /* Wakeup the master engine to go ahead. */
@@ -3552,6 +3653,9 @@ static int lfsck_layout_assistant(void *args)
                        llmd->llmd_in_double_scan = 1;
                        wake_up_all(&mthread->t_ctl_waitq);
 
+                       CDEBUG(D_LFSCK, "%s: layout LFSCK assistant phase2 "
+                              "scan start\n", lfsck_lfsck2name(lfsck));
+
                        com->lc_new_checked = 0;
                        com->lc_new_scanned = 0;
                        com->lc_time_last_checkpoint = cfs_time_current();
@@ -3673,7 +3777,7 @@ cleanup2:
                                lr->lr_status = LS_CO_STOPPED;
                                break;
                        default:
-                               CERROR("%s: unknown status: rc = %d\n",
+                               CDEBUG(D_LFSCK, "%s: unknown status: rc = %d\n",
                                       lfsck_lfsck2name(lfsck),
                                       lfsck->li_status);
                                lr->lr_status = LS_CO_FAILED;
@@ -3692,7 +3796,8 @@ cleanup2:
 
        rc1 = lfsck_layout_master_notify_others(env, com, lr);
        if (rc1 != 0) {
-               CERROR("%s: failed to notify others for layout quit: rc = %d\n",
+               CDEBUG(D_LFSCK, "%s: layout LFSCK assistant failed to "
+                      "notify others for LFSCK quit: rc = %d\n",
                       lfsck_lfsck2name(lfsck), rc1);
                rc = rc1;
        }
@@ -3700,8 +3805,16 @@ cleanup2:
        /* Under force exit case, some requests may be just freed without
         * verification, those objects should be re-handled when next run.
         * So not update the on-disk tracing file under such case. */
-       if (llmd->llmd_in_double_scan && !llmd->llmd_exit)
-               rc1 = lfsck_layout_double_scan_result(env, com, rc);
+       if (llmd->llmd_in_double_scan) {
+               struct lfsck_layout *lo = com->lc_file_ram;
+
+               if (!llmd->llmd_exit)
+                       rc1 = lfsck_layout_double_scan_result(env, com, rc);
+
+               CDEBUG(D_LFSCK, "%s: layout LFSCK assistant phase2 scan "
+                      "finished, status %d: rc = %d\n",
+                      lfsck_lfsck2name(lfsck), lo->ll_status, rc1);
+       }
 
 fini:
        if (llmd->llmd_in_double_scan)
@@ -3727,6 +3840,7 @@ lfsck_layout_slave_async_interpret(const struct lu_env *env,
        struct lfsck_component               *com   = llsaa->llsaa_com;
        struct lfsck_layout_slave_target     *llst  = llsaa->llsaa_llst;
        struct lfsck_layout_slave_data       *llsd  = com->lc_data;
+       struct lfsck_reply                   *lr    = NULL;
        bool                                  done  = false;
 
        if (rc != 0) {
@@ -3735,15 +3849,20 @@ lfsck_layout_slave_async_interpret(const struct lu_env *env,
                 * the target finished the LFSCK prcoessing. */
                done = true;
        } else {
-               struct lfsck_reply *lr;
-
                lr = req_capsule_server_get(&req->rq_pill, &RMF_LFSCK_REPLY);
                if (lr->lr_status != LS_SCANNING_PHASE1 &&
                    lr->lr_status != LS_SCANNING_PHASE2)
                        done = true;
        }
-       if (done)
+
+       if (done) {
+               CDEBUG(D_LFSCK, "%s: layout LFSCK slave gets the MDT %x "
+                      "status %d\n", lfsck_lfsck2name(com->lc_lfsck),
+                      llst->llst_index, lr != NULL ? lr->lr_status : rc);
+
                lfsck_layout_llst_del(llsd, llst);
+       }
+
        lfsck_layout_llst_put(llst);
        lfsck_component_put(env, com);
        class_export_put(exp);
@@ -3832,12 +3951,12 @@ lfsck_layout_slave_query_master(const struct lu_env *env,
 
        set = ptlrpc_prep_set();
        if (set == NULL)
-               RETURN(-ENOMEM);
+               GOTO(log, rc = -ENOMEM);
 
        memset(lr, 0, sizeof(*lr));
        lr->lr_index = lfsck_dev_idx(lfsck->li_bottom);
        lr->lr_event = LE_QUERY;
-       lr->lr_active = LT_LAYOUT;
+       lr->lr_active = LFSCK_TYPE_LAYOUT;
 
        llsd->llsd_touch_gen++;
        spin_lock(&llsd->llsd_lock);
@@ -3866,9 +3985,11 @@ lfsck_layout_slave_query_master(const struct lu_env *env,
 
                rc = lfsck_layout_async_query(env, com, exp, llst, lr, set);
                if (rc != 0) {
-                       CERROR("%s: slave fail to query %s for layout: "
-                              "rc = %d\n", lfsck_lfsck2name(lfsck),
+                       CDEBUG(D_LFSCK, "%s: layout LFSCK slave fail to "
+                              "query %s for layout: rc = %d\n",
+                              lfsck_lfsck2name(lfsck),
                               exp->exp_obd->obd_name, rc);
+
                        rc1 = rc;
                        lfsck_layout_llst_put(llst);
                        class_export_put(exp);
@@ -3880,7 +4001,13 @@ lfsck_layout_slave_query_master(const struct lu_env *env,
        rc = ptlrpc_set_wait(set);
        ptlrpc_set_destroy(set);
 
-       RETURN(rc1 != 0 ? rc1 : rc);
+       GOTO(log, rc = (rc1 != 0 ? rc1 : rc));
+
+log:
+       CDEBUG(D_LFSCK, "%s: layout LFSCK slave queries master: rc = %d\n",
+              lfsck_lfsck2name(com->lc_lfsck), rc);
+
+       return rc;
 }
 
 static void
@@ -3897,6 +4024,9 @@ lfsck_layout_slave_notify_master(const struct lu_env *env,
        int                               rc;
        ENTRY;
 
+       CDEBUG(D_LFSCK, "%s: layout LFSCK slave notifies master\n",
+              lfsck_lfsck2name(com->lc_lfsck));
+
        set = ptlrpc_prep_set();
        if (set == NULL)
                RETURN_EXIT;
@@ -3906,7 +4036,7 @@ lfsck_layout_slave_notify_master(const struct lu_env *env,
        lr->lr_flags = LEF_FROM_OST;
        lr->lr_status = result;
        lr->lr_index = lfsck_dev_idx(lfsck->li_bottom);
-       lr->lr_active = LT_LAYOUT;
+       lr->lr_active = LFSCK_TYPE_LAYOUT;
        llsd->llsd_touch_gen++;
        spin_lock(&llsd->llsd_lock);
        while (!list_empty(&llsd->llsd_master_list)) {
@@ -3934,9 +4064,11 @@ lfsck_layout_slave_notify_master(const struct lu_env *env,
 
                rc = lfsck_layout_async_notify(env, exp, lr, set);
                if (rc != 0)
-                       CERROR("%s: slave fail to notify %s for layout: "
-                              "rc = %d\n", lfsck_lfsck2name(lfsck),
+                       CDEBUG(D_LFSCK, "%s: layout LFSCK slave fail to "
+                              "notify %s for layout: rc = %d\n",
+                              lfsck_lfsck2name(lfsck),
                               exp->exp_obd->obd_name, rc);
+
                lfsck_layout_llst_put(llst);
                class_export_put(exp);
                spin_lock(&llsd->llsd_lock);
@@ -4083,7 +4215,7 @@ static int lfsck_layout_slave_check_pairs(const struct lu_env *env,
        lr = req_capsule_client_get(&req->rq_pill, &RMF_LFSCK_REQUEST);
        memset(lr, 0, sizeof(*lr));
        lr->lr_event = LE_PAIRS_VERIFY;
-       lr->lr_active = LT_LAYOUT;
+       lr->lr_active = LFSCK_TYPE_LAYOUT;
        lr->lr_fid = *cfid; /* OST-object itself FID. */
        lr->lr_fid2 = *pfid; /* The claimed parent FID. */
 
@@ -4118,7 +4250,7 @@ static int lfsck_layout_slave_repair_pfid(const struct lu_env *env,
 
        obj = lfsck_object_find_by_dev(env, dev, &lr->lr_fid);
        if (IS_ERR(obj))
-               RETURN(PTR_ERR(obj));
+               GOTO(log, rc = PTR_ERR(obj));
 
        fid_cpu_to_le(&ff->ff_parent, &lr->lr_fid2);
        buf = lfsck_buf_get(env, ff, sizeof(*ff));
@@ -4149,6 +4281,11 @@ unlock:
        dt_write_unlock(env, obj);
        lu_object_put(env, &obj->do_lu);
 
+log:
+       CDEBUG(D_LFSCK, "%s: layout LFSCK slave repaired pfid for "DFID
+              ", parent "DFID": rc = %d\n", lfsck_lfsck2name(com->lc_lfsck),
+              PFID(&lr->lr_fid), PFID(&lr->lr_fid2), rc);
+
        return rc;
 }
 
@@ -4178,6 +4315,9 @@ static int lfsck_layout_reset(const struct lu_env *env,
        rc = lfsck_layout_store(env, com);
        up_write(&com->lc_sem);
 
+       CDEBUG(D_LFSCK, "%s: layout LFSCK reset: rc = %d\n",
+              lfsck_lfsck2name(com->lc_lfsck), rc);
+
        return rc;
 }
 
@@ -4232,6 +4372,10 @@ static int lfsck_layout_master_checkpoint(const struct lu_env *env,
        rc = lfsck_layout_store(env, com);
        up_write(&com->lc_sem);
 
+       CDEBUG(D_LFSCK, "%s: layout LFSCK master checkpoint at the pos ["
+              LPU64"]: rc = %d\n", lfsck_lfsck2name(lfsck),
+              lfsck->li_pos_current.lp_oit_cookie, rc);
+
        return rc;
 }
 
@@ -4246,7 +4390,6 @@ static int lfsck_layout_slave_checkpoint(const struct lu_env *env,
                return 0;
 
        down_write(&com->lc_sem);
-
        if (init) {
                lo->ll_pos_latest_start = lfsck->li_pos_current.lp_oit_cookie;
        } else {
@@ -4260,9 +4403,12 @@ static int lfsck_layout_slave_checkpoint(const struct lu_env *env,
        }
 
        rc = lfsck_layout_store(env, com);
-
        up_write(&com->lc_sem);
 
+       CDEBUG(D_LFSCK, "%s: layout LFSCK slave checkpoint at the pos ["
+              LPU64"]: rc = %d\n", lfsck_lfsck2name(lfsck),
+              lfsck->li_pos_current.lp_oit_cookie, rc);
+
        return rc;
 }
 
@@ -4286,8 +4432,12 @@ static int lfsck_layout_prep(const struct lu_env *env,
                if (rc == 0)
                        rc = lfsck_set_param(env, lfsck, start, true);
 
-               if (rc != 0)
+               if (rc != 0) {
+                       CDEBUG(D_LFSCK, "%s: layout LFSCK prep failed: "
+                              "rc = %d\n", lfsck_lfsck2name(lfsck), rc);
+
                        return rc;
+               }
        }
 
        down_write(&com->lc_sem);
@@ -4365,6 +4515,10 @@ static int lfsck_layout_slave_prep(const struct lu_env *env,
                write_unlock(&llsd->llsd_rb_lock);
        }
 
+       CDEBUG(D_LFSCK, "%s: layout LFSCK slave prep done, start pos ["
+              LPU64"]\n", lfsck_lfsck2name(lfsck),
+              com->lc_pos_start.lp_oit_cookie);
+
        return rc;
 }
 
@@ -4400,7 +4554,7 @@ static int lfsck_layout_master_prep(const struct lu_env *env,
        task = kthread_run(lfsck_layout_assistant, lta, "lfsck_layout");
        if (IS_ERR(task)) {
                rc = PTR_ERR(task);
-               CERROR("%s: Cannot start LFSCK layout assistant thread: "
+               CERROR("%s: cannot start LFSCK layout assistant thread: "
                       "rc = %d\n", lfsck_lfsck2name(lfsck), rc);
                lfsck_thread_args_fini(lta);
        } else {
@@ -4416,6 +4570,10 @@ static int lfsck_layout_master_prep(const struct lu_env *env,
                        rc = 0;
        }
 
+       CDEBUG(D_LFSCK, "%s: layout LFSCK master prep done, start pos ["
+              LPU64"\n", lfsck_lfsck2name(lfsck),
+              com->lc_pos_start.lp_oit_cookie);
+
        RETURN(rc);
 }
 
@@ -4488,8 +4646,8 @@ static int lfsck_layout_scan_stripes(const struct lu_env *env,
                ostid_to_fid(fid, oi, index);
                tgt = lfsck_tgt_get(ltds, index);
                if (unlikely(tgt == NULL)) {
-                       CERROR("%s: Cannot talk with OST %x which did not join "
-                              "the layout LFSCK.\n",
+                       CDEBUG(D_LFSCK, "%s: cannot talk with OST %x which "
+                              "did not join the layout LFSCK\n",
                               lfsck_lfsck2name(lfsck), index);
                        lo->ll_flags |= LF_INCOMPLETE;
                        goto next;
@@ -4595,6 +4753,7 @@ static int lfsck_layout_master_exec_oit(const struct lu_env *env,
        int                              rc     = 0;
        bool                             locked = false;
        bool                             stripe = false;
+       bool                             bad_oi = false;
        ENTRY;
 
        if (!S_ISREG(lfsck_object_type(obj)))
@@ -4625,8 +4784,7 @@ again:
                GOTO(out, stripe = true);
 
        /* Inconsistent lmm_oi, should be repaired. */
-       CDEBUG(D_LFSCK, "Repair bad lmm_oi for "DFID"\n",
-              PFID(lfsck_dto2fid(obj)));
+       bad_oi = true;
 
        if (bk->lb_param & LPF_DRYRUN) {
                down_write(&com->lc_sem);
@@ -4689,6 +4847,13 @@ out:
                dt_trans_stop(env, dev, handle);
 
        lfsck_layout_unlock(&lh);
+
+       if (bad_oi)
+               CDEBUG(D_LFSCK, "%s: layout LFSCK master %s bad lmm_oi for "
+                      DFID": rc = %d\n", lfsck_lfsck2name(lfsck),
+                      bk->lb_param & LPF_DRYRUN ? "found" : "repaired",
+                      PFID(lfsck_dto2fid(obj)), rc);
+
        if (stripe) {
                rc = lfsck_layout_scan_stripes(env, com, obj, lmm);
        } else {
@@ -4752,6 +4917,9 @@ static int lfsck_layout_slave_exec_oit(const struct lu_env *env,
                lls->lls_seq = seq;
                rc = lfsck_layout_lastid_load(env, com, lls);
                if (rc != 0) {
+                       CDEBUG(D_LFSCK, "%s: layout LFSCK failed to "
+                             "load LAST_ID for "LPX64": rc = %d\n",
+                             lfsck_lfsck2name(com->lc_lfsck), seq, rc);
                        lo->ll_objs_failed_phase1++;
                        OBD_FREE_PTR(lls);
                        GOTO(unlock, rc);
@@ -4772,8 +4940,8 @@ static int lfsck_layout_slave_exec_oit(const struct lu_env *env,
                        /* OFD may create new objects during LFSCK scanning. */
                        rc = lfsck_layout_lastid_reload(env, com, lls);
                        if (unlikely(rc != 0))
-                               CWARN("%s: failed to reload LAST_ID for "LPX64
-                                     ": rc = %d\n",
+                               CDEBUG(D_LFSCK, "%s: layout LFSCK failed to "
+                                     "reload LAST_ID for "LPX64": rc = %d\n",
                                      lfsck_lfsck2name(com->lc_lfsck),
                                      lls->lls_seq, rc);
                        if (oid <= lls->lls_lastid)
@@ -4875,6 +5043,9 @@ static int lfsck_layout_master_post(const struct lu_env *env,
        rc = lfsck_layout_store(env, com);
        up_write(&com->lc_sem);
 
+       CDEBUG(D_LFSCK, "%s: layout LFSCK master post done: rc = %d\n",
+              lfsck_lfsck2name(lfsck), rc);
+
        RETURN(rc);
 }
 
@@ -4894,7 +5065,6 @@ static int lfsck_layout_slave_post(const struct lu_env *env,
        LASSERT(lfsck->li_out_notify != NULL);
 
        down_write(&com->lc_sem);
-
        spin_lock(&lfsck->li_lock);
        if (!init)
                lo->ll_pos_last_checkpoint =
@@ -4937,7 +5107,6 @@ static int lfsck_layout_slave_post(const struct lu_env *env,
        }
 
        rc = lfsck_layout_store(env, com);
-
        up_write(&com->lc_sem);
 
        lfsck_layout_slave_notify_master(env, com, LE_PHASE1_DONE, result);
@@ -4945,73 +5114,60 @@ static int lfsck_layout_slave_post(const struct lu_env *env,
        if (result <= 0)
                lfsck_rbtree_cleanup(env, com);
 
+       CDEBUG(D_LFSCK, "%s: layout LFSCK slave post done: rc = %d\n",
+              lfsck_lfsck2name(lfsck), rc);
+
        return rc;
 }
 
 static int lfsck_layout_dump(const struct lu_env *env,
-                            struct lfsck_component *com, char *buf, int len)
+                            struct lfsck_component *com, struct seq_file *m)
 {
        struct lfsck_instance   *lfsck = com->lc_lfsck;
        struct lfsck_bookmark   *bk    = &lfsck->li_bookmark_ram;
        struct lfsck_layout     *lo    = com->lc_file_ram;
-       int                      save  = len;
-       int                      ret   = -ENOSPC;
        int                      rc;
 
        down_read(&com->lc_sem);
-       rc = snprintf(buf, len,
-                     "name: lfsck_layout\n"
+       seq_printf(m, "name: lfsck_layout\n"
                      "magic: %#x\n"
                      "version: %d\n"
                      "status: %s\n",
                      lo->ll_magic,
                      bk->lb_version,
                      lfsck_status2names(lo->ll_status));
-       if (rc <= 0)
-               goto out;
 
-       buf += rc;
-       len -= rc;
-       rc = lfsck_bits_dump(&buf, &len, lo->ll_flags, lfsck_flags_names,
-                            "flags");
+       rc = lfsck_bits_dump(m, lo->ll_flags, lfsck_flags_names, "flags");
        if (rc < 0)
                goto out;
 
-       rc = lfsck_bits_dump(&buf, &len, bk->lb_param, lfsck_param_names,
-                            "param");
+       rc = lfsck_bits_dump(m, bk->lb_param, lfsck_param_names, "param");
        if (rc < 0)
                goto out;
 
-       rc = lfsck_time_dump(&buf, &len, lo->ll_time_last_complete,
+       rc = lfsck_time_dump(m, lo->ll_time_last_complete,
                             "time_since_last_completed");
        if (rc < 0)
                goto out;
 
-       rc = lfsck_time_dump(&buf, &len, lo->ll_time_latest_start,
+       rc = lfsck_time_dump(m, lo->ll_time_latest_start,
                             "time_since_latest_start");
        if (rc < 0)
                goto out;
 
-       rc = lfsck_time_dump(&buf, &len, lo->ll_time_last_checkpoint,
+       rc = lfsck_time_dump(m, lo->ll_time_last_checkpoint,
                             "time_since_last_checkpoint");
        if (rc < 0)
                goto out;
 
-       rc = snprintf(buf, len,
-                     "latest_start_position: "LPU64"\n"
+       seq_printf(m, "latest_start_position: "LPU64"\n"
                      "last_checkpoint_position: "LPU64"\n"
                      "first_failure_position: "LPU64"\n",
                      lo->ll_pos_latest_start,
                      lo->ll_pos_last_checkpoint,
                      lo->ll_pos_first_inconsistent);
-       if (rc <= 0)
-               goto out;
 
-       buf += rc;
-       len -= rc;
-
-       rc = snprintf(buf, len,
-                     "success_count: %u\n"
+       seq_printf(m, "success_count: %u\n"
                      "repaired_dangling: "LPU64"\n"
                      "repaired_unmatched_pair: "LPU64"\n"
                      "repaired_multiple_referenced: "LPU64"\n"
@@ -5031,11 +5187,6 @@ static int lfsck_layout_dump(const struct lu_env *env,
                      lo->ll_objs_skipped,
                      lo->ll_objs_failed_phase1,
                      lo->ll_objs_failed_phase2);
-       if (rc <= 0)
-               goto out;
-
-       buf += rc;
-       len -= rc;
 
        if (lo->ll_status == LS_SCANNING_PHASE1) {
                __u64 pos;
@@ -5053,8 +5204,7 @@ static int lfsck_layout_dump(const struct lu_env *env,
                        do_div(new_checked, duration);
                if (rtime != 0)
                        do_div(speed, rtime);
-               rc = snprintf(buf, len,
-                             "checked_phase1: "LPU64"\n"
+               seq_printf(m, "checked_phase1: "LPU64"\n"
                              "checked_phase2: "LPU64"\n"
                              "run_time_phase1: %u seconds\n"
                              "run_time_phase2: %u seconds\n"
@@ -5068,11 +5218,6 @@ static int lfsck_layout_dump(const struct lu_env *env,
                              lo->ll_run_time_phase2,
                              speed,
                              new_checked);
-               if (rc <= 0)
-                       goto out;
-
-               buf += rc;
-               len -= rc;
 
                LASSERT(lfsck->li_di_oit != NULL);
 
@@ -5085,12 +5230,8 @@ static int lfsck_layout_dump(const struct lu_env *env,
                pos = iops->store(env, lfsck->li_di_oit);
                if (!lfsck->li_current_oit_processed)
                        pos--;
-               rc = snprintf(buf, len, "current_position: "LPU64"\n", pos);
-               if (rc <= 0)
-                       goto out;
+               seq_printf(m, "current_position: "LPU64"\n", pos);
 
-               buf += rc;
-               len -= rc;
        } else if (lo->ll_status == LS_SCANNING_PHASE2) {
                cfs_duration_t duration = cfs_time_current() -
                                          lfsck->li_time_last_checkpoint;
@@ -5108,29 +5249,26 @@ static int lfsck_layout_dump(const struct lu_env *env,
                        do_div(speed1, lo->ll_run_time_phase1);
                if (rtime != 0)
                        do_div(speed2, rtime);
-               rc = snprintf(buf, len,
-                             "checked_phase1: "LPU64"\n"
-                             "checked_phase2: "LPU64"\n"
-                             "run_time_phase1: %u seconds\n"
-                             "run_time_phase2: %u seconds\n"
-                             "average_speed_phase1: "LPU64" items/sec\n"
-                             "average_speed_phase2: "LPU64" items/sec\n"
-                             "real-time_speed_phase1: N/A\n"
-                             "real-time_speed_phase2: "LPU64" items/sec\n"
-                             "current_position: "DFID"\n",
-                             lo->ll_objs_checked_phase1,
-                             checked,
-                             lo->ll_run_time_phase1,
-                             rtime,
-                             speed1,
-                             speed2,
-                             new_checked,
-                             PFID(&com->lc_fid_latest_scanned_phase2));
+               rc = seq_printf(m, "checked_phase1: "LPU64"\n"
+                               "checked_phase2: "LPU64"\n"
+                               "run_time_phase1: %u seconds\n"
+                               "run_time_phase2: %u seconds\n"
+                               "average_speed_phase1: "LPU64" items/sec\n"
+                               "average_speed_phase2: "LPU64" items/sec\n"
+                               "real-time_speed_phase1: N/A\n"
+                               "real-time_speed_phase2: "LPU64" items/sec\n"
+                               "current_position: "DFID"\n",
+                               lo->ll_objs_checked_phase1,
+                               checked,
+                               lo->ll_run_time_phase1,
+                               rtime,
+                               speed1,
+                               speed2,
+                               new_checked,
+                               PFID(&com->lc_fid_latest_scanned_phase2));
                if (rc <= 0)
                        goto out;
 
-               buf += rc;
-               len -= rc;
        } else {
                __u64 speed1 = lo->ll_objs_checked_phase1;
                __u64 speed2 = lo->ll_objs_checked_phase2;
@@ -5139,34 +5277,26 @@ static int lfsck_layout_dump(const struct lu_env *env,
                        do_div(speed1, lo->ll_run_time_phase1);
                if (lo->ll_run_time_phase2 != 0)
                        do_div(speed2, lo->ll_run_time_phase2);
-               rc = snprintf(buf, len,
-                             "checked_phase1: "LPU64"\n"
-                             "checked_phase2: "LPU64"\n"
-                             "run_time_phase1: %u seconds\n"
-                             "run_time_phase2: %u seconds\n"
-                             "average_speed_phase1: "LPU64" items/sec\n"
-                             "average_speed_phase2: "LPU64" objs/sec\n"
-                             "real-time_speed_phase1: N/A\n"
-                             "real-time_speed_phase2: N/A\n"
-                             "current_position: N/A\n",
-                             lo->ll_objs_checked_phase1,
-                             lo->ll_objs_checked_phase2,
-                             lo->ll_run_time_phase1,
-                             lo->ll_run_time_phase2,
-                             speed1,
-                             speed2);
-               if (rc <= 0)
-                       goto out;
-
-               buf += rc;
-               len -= rc;
+               seq_printf(m, "checked_phase1: "LPU64"\n"
+                          "checked_phase2: "LPU64"\n"
+                          "run_time_phase1: %u seconds\n"
+                          "run_time_phase2: %u seconds\n"
+                          "average_speed_phase1: "LPU64" items/sec\n"
+                          "average_speed_phase2: "LPU64" objs/sec\n"
+                          "real-time_speed_phase1: N/A\n"
+                          "real-time_speed_phase2: N/A\n"
+                          "current_position: N/A\n",
+                          lo->ll_objs_checked_phase1,
+                          lo->ll_objs_checked_phase2,
+                          lo->ll_run_time_phase1,
+                          lo->ll_run_time_phase2,
+                          speed1,
+                          speed2);
        }
-       ret = save - len;
-
 out:
        up_read(&com->lc_sem);
 
-       return ret;
+       return rc;
 }
 
 static int lfsck_layout_master_double_scan(const struct lu_env *env,
@@ -5209,6 +5339,9 @@ static int lfsck_layout_slave_double_scan(const struct lu_env *env,
                RETURN(0);
        }
 
+       CDEBUG(D_LFSCK, "%s: layout LFSCK slave phase2 scan start\n",
+              lfsck_lfsck2name(lfsck));
+
        atomic_inc(&lfsck->li_double_scan_count);
 
        com->lc_new_checked = 0;
@@ -5255,6 +5388,10 @@ done:
        if (atomic_dec_and_test(&lfsck->li_double_scan_count))
                wake_up_all(&lfsck->li_thread.t_ctl_waitq);
 
+       CDEBUG(D_LFSCK, "%s: layout LFSCK slave phase2 scan finished, "
+              "status %d: rc = %d\n",
+              lfsck_lfsck2name(lfsck), lo->ll_status, rc);
+
        return rc;
 }
 
@@ -5288,6 +5425,10 @@ static void lfsck_layout_master_data_release(const struct lu_env *env,
                                 ltd_layout_list) {
                list_del_init(&ltd->ltd_layout_list);
        }
+       spin_unlock(&ltds->ltd_lock);
+
+       ltds = &lfsck->li_mdt_descs;
+       spin_lock(&ltds->ltd_lock);
        list_for_each_entry_safe(ltd, next, &llmd->llmd_mdt_phase1_list,
                                 ltd_layout_phase_list) {
                list_del_init(&ltd->ltd_layout_phase_list);
@@ -5377,6 +5518,11 @@ static int lfsck_layout_master_in_notify(const struct lu_env *env,
                RETURN(rc);
        }
 
+       CDEBUG(D_LFSCK, "%s: layout LFSCK master handle notify %u "
+              "from %s %x, status %d\n", lfsck_lfsck2name(lfsck),
+              lr->lr_event, (lr->lr_flags & LEF_TO_OST) ? "OST" : "MDT",
+              lr->lr_index, lr->lr_status);
+
        if (lr->lr_event != LE_PHASE1_DONE &&
            lr->lr_event != LE_PHASE2_DONE &&
            lr->lr_event != LE_PEER_EXIT)
@@ -5400,10 +5546,6 @@ static int lfsck_layout_master_in_notify(const struct lu_env *env,
                if (lr->lr_status <= 0) {
                        ltd->ltd_layout_done = 1;
                        list_del_init(&ltd->ltd_layout_list);
-                       CWARN("%s: %s %x failed/stopped at phase1: rc = %d.\n",
-                             lfsck_lfsck2name(lfsck),
-                             (lr->lr_flags & LEF_TO_OST) ? "OST" : "MDT",
-                             ltd->ltd_index, lr->lr_status);
                        lo->ll_flags |= LF_INCOMPLETE;
                        fail = true;
                        break;
@@ -5431,13 +5573,8 @@ static int lfsck_layout_master_in_notify(const struct lu_env *env,
                fail = true;
                ltd->ltd_layout_done = 1;
                list_del_init(&ltd->ltd_layout_list);
-               if (!(lfsck->li_bookmark_ram.lb_param & LPF_FAILOUT)) {
-                       CWARN("%s: the peer %s %x exit layout LFSCK.\n",
-                             lfsck_lfsck2name(lfsck),
-                             (lr->lr_flags & LEF_TO_OST) ? "OST" : "MDT",
-                             ltd->ltd_index);
+               if (!(lfsck->li_bookmark_ram.lb_param & LPF_FAILOUT))
                        lo->ll_flags |= LF_INCOMPLETE;
-               }
                break;
        default:
                break;
@@ -5510,6 +5647,9 @@ static int lfsck_layout_slave_in_notify(const struct lu_env *env,
        }
        case LE_PHASE2_DONE:
        case LE_PEER_EXIT:
+               CDEBUG(D_LFSCK, "%s: layout LFSCK slave handle notify %u "
+                      "from MDT %x, status %d\n", lfsck_lfsck2name(lfsck),
+                      lr->lr_event, lr->lr_index, lr->lr_status);
                break;
        default:
                RETURN(-EINVAL);
@@ -5571,7 +5711,7 @@ static int lfsck_layout_master_stop_notify(const struct lu_env *env,
        memset(lr, 0, sizeof(*lr));
        lr->lr_index = lfsck_dev_idx(lfsck->li_bottom);
        lr->lr_event = LE_PEER_EXIT;
-       lr->lr_active = LT_LAYOUT;
+       lr->lr_active = LFSCK_TYPE_LAYOUT;
        lr->lr_status = LS_CO_PAUSED;
        if (ltds == &lfsck->li_ost_descs)
                lr->lr_flags = LEF_TO_OST;
@@ -5587,7 +5727,8 @@ static int lfsck_layout_master_stop_notify(const struct lu_env *env,
                                 lfsck_layout_master_async_interpret,
                                 laia, LFSCK_NOTIFY);
        if (rc != 0) {
-               CERROR("%s: Fail to notify %s %x for co-stop: rc = %d\n",
+               CDEBUG(D_LFSCK, "%s: layout LFSCK fail to notify %s %x "
+                      "for co-stop: rc = %d\n",
                       lfsck_lfsck2name(lfsck),
                       (lr->lr_flags & LEF_TO_OST) ? "OST" : "MDT",
                       ltd->ltd_index, rc);
@@ -5609,10 +5750,17 @@ static int lfsck_layout_slave_join(const struct lu_env *env,
        int                               rc    = 0;
        ENTRY;
 
-       if (!lsp->lsp_index_valid || start == NULL ||
-           !(start->ls_flags & LPF_ALL_TGT) ||
-           !(lfsck->li_bookmark_ram.lb_param & LPF_ALL_TGT))
-               RETURN(-EALREADY);
+       if (start == NULL || !(start->ls_flags & LPF_ORPHAN))
+               RETURN(0);
+
+       if (!lsp->lsp_index_valid)
+               RETURN(-EINVAL);
+
+       /* If someone is running the LFSCK without orphan handling,
+        * it will not maintain the object accessing rbtree. So we
+        * cannot join it for orphan handling. */
+       if (!llsd->llsd_rbtree_valid)
+               RETURN(-EBUSY);
 
        spin_unlock(&lfsck->li_lock);
        rc = lfsck_layout_llst_add(llsd, lsp->lsp_index);
@@ -5683,7 +5831,7 @@ int lfsck_layout_setup(const struct lu_env *env, struct lfsck_instance *lfsck)
        init_rwsem(&com->lc_sem);
        atomic_set(&com->lc_ref, 1);
        com->lc_lfsck = lfsck;
-       com->lc_type = LT_LAYOUT;
+       com->lc_type = LFSCK_TYPE_LAYOUT;
        if (lfsck->li_master) {
                struct lfsck_layout_master_data *llmd;
 
@@ -5761,7 +5909,7 @@ int lfsck_layout_setup(const struct lu_env *env, struct lfsck_instance *lfsck)
                spin_unlock(&lfsck->li_lock);
                break;
        default:
-               CERROR("%s: unknown lfsck_layout status: rc = %u\n",
+               CERROR("%s: unknown lfsck_layout status %d\n",
                       lfsck_lfsck2name(lfsck), lo->ll_status);
                /* fall through */
        case LS_SCANNING_PHASE1:
@@ -5796,8 +5944,11 @@ out:
        if (root != NULL && !IS_ERR(root))
                lu_object_put(env, &root->do_lu);
 
-       if (rc != 0)
+       if (rc != 0) {
                lfsck_component_cleanup(env, com);
+               CERROR("%s: fail to init layout LFSCK component: rc = %d\n",
+                      lfsck_lfsck2name(lfsck), rc);
+       }
 
        return rc;
 }
@@ -5885,6 +6036,9 @@ static void lfsck_layout_destroy_orphan(const struct lu_env *env,
 stop:
        dt_trans_stop(env, dev, handle);
 
+       CDEBUG(D_LFSCK, "destroy orphan OST-object "DFID": rc = %d\n",
+              PFID(lfsck_dto2fid(obj)), rc);
+
        RETURN_EXIT;
 }
 
@@ -5951,7 +6105,7 @@ static struct dt_it *lfsck_orphan_it_init(const struct lu_env *env,
        if (unlikely(lfsck == NULL))
                RETURN(ERR_PTR(-ENXIO));
 
-       com = lfsck_component_find(lfsck, LT_LAYOUT);
+       com = lfsck_component_find(lfsck, LFSCK_TYPE_LAYOUT);
        if (unlikely(com == NULL))
                GOTO(out, rc = -ENOENT);
 
@@ -6005,6 +6159,10 @@ static struct dt_it *lfsck_orphan_it_init(const struct lu_env *env,
 out:
        if (com != NULL)
                lfsck_component_put(env, com);
+
+       CDEBUG(D_LFSCK, "%s: init the orphan iteration: rc = %d\n",
+              lfsck_lfsck2name(lfsck), rc);
+
        lfsck_instance_put(env, lfsck);
        if (rc != 0) {
                if (it != NULL)
@@ -6025,6 +6183,9 @@ static void lfsck_orphan_it_fini(const struct lu_env *env,
        struct lfsck_layout_slave_target *llst;
 
        if (com != NULL) {
+               CDEBUG(D_LFSCK, "%s: fini the orphan iteration\n",
+                      lfsck_lfsck2name(com->lc_lfsck));
+
                llsd = com->lc_data;
                read_unlock(&llsd->llsd_rb_lock);
                llst = it->loi_llst;
@@ -6325,10 +6486,11 @@ static int lfsck_orphan_it_load(const struct lu_env *env,
        LASSERT(llst != NULL);
 
        if (hash != llst->llst_hash) {
-               CWARN("%s: the given hash "LPU64" for orphan iteration does "
-                     "not match the one when fini "LPU64", to be reset.\n",
-                     lfsck_lfsck2name(it->loi_com->lc_lfsck), hash,
-                     llst->llst_hash);
+               CDEBUG(D_LFSCK, "%s: the given hash "LPU64" for orphan "
+                      "iteration does not match the one when fini "
+                      LPU64", to be reset.\n",
+                      lfsck_lfsck2name(it->loi_com->lc_lfsck), hash,
+                      llst->llst_hash);
                fid_zero(&llst->llst_fid);
                llst->llst_hash = 0;
        }