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LU-8929 lfsck: dumper gets current position properly
[fs/lustre-release.git] / lustre / lfsck / lfsck_layout.c
index bb873c8..8ce6086 100644 (file)
@@ -20,7 +20,7 @@
  * GPL HEADER END
  */
 /*
- * Copyright (c) 2014, Intel Corporation.
+ * Copyright (c) 2014, 2016, Intel Corporation.
  */
 /*
  * lustre/lfsck/lfsck_layout.c
@@ -72,6 +72,8 @@ struct lfsck_layout_slave_target {
        __u64                   llst_gen;
        atomic_t                llst_ref;
        __u32                   llst_index;
+       /* How many times we have failed to get the master status. */
+       int                     llst_failures;
 };
 
 struct lfsck_layout_slave_data {
@@ -88,50 +90,12 @@ struct lfsck_layout_slave_data {
        unsigned int             llsd_rbtree_valid:1;
 };
 
-struct lfsck_layout_object {
-       struct lu_attr           llo_attr;
-       atomic_t                 llo_ref;
-       __u64                    llo_cookie;
-};
-
-struct lfsck_layout_req {
-       struct lfsck_assistant_req       llr_lar;
-       struct lfsck_layout_object      *llr_parent;
-       struct dt_object                *llr_child;
-       __u32                            llr_ost_idx;
-       __u32                            llr_lov_idx; /* offset in LOV EA */
-};
-
 struct lfsck_layout_slave_async_args {
        struct obd_export                *llsaa_exp;
        struct lfsck_component           *llsaa_com;
        struct lfsck_layout_slave_target *llsaa_llst;
 };
 
-static struct lfsck_layout_object *
-lfsck_layout_object_init(const struct lu_env *env, struct dt_object *obj,
-                        __u64 cookie)
-{
-       struct lfsck_layout_object *llo;
-       int                         rc;
-
-       OBD_ALLOC_PTR(llo);
-       if (llo == NULL)
-               return ERR_PTR(-ENOMEM);
-
-       rc = dt_attr_get(env, obj, &llo->llo_attr);
-       if (rc != 0) {
-               OBD_FREE_PTR(llo);
-
-               return ERR_PTR(rc);
-       }
-
-       llo->llo_cookie = cookie;
-       atomic_set(&llo->llo_ref, 1);
-
-       return llo;
-}
-
 static inline void
 lfsck_layout_llst_put(struct lfsck_layout_slave_target *llst)
 {
@@ -215,16 +179,8 @@ lfsck_layout_llst_find_and_del(struct lfsck_layout_slave_data *llsd,
        return NULL;
 }
 
-static inline void lfsck_layout_object_put(const struct lu_env *env,
-                                          struct lfsck_layout_object *llo)
-{
-       if (atomic_dec_and_test(&llo->llo_ref))
-               OBD_FREE_PTR(llo);
-}
-
 static struct lfsck_layout_req *
-lfsck_layout_assistant_req_init(struct lfsck_layout_object *parent,
-                               const struct lu_fid *pfid,
+lfsck_layout_assistant_req_init(struct lfsck_assistant_object *lso,
                                struct dt_object *child, __u32 ost_idx,
                                __u32 lov_idx)
 {
@@ -235,10 +191,7 @@ lfsck_layout_assistant_req_init(struct lfsck_layout_object *parent,
                return ERR_PTR(-ENOMEM);
 
        INIT_LIST_HEAD(&llr->llr_lar.lar_list);
-       llr->llr_lar.lar_fid = *pfid;
-
-       atomic_inc(&parent->llo_ref);
-       llr->llr_parent = parent;
+       llr->llr_lar.lar_parent = lfsck_assistant_object_get(lso);
        llr->llr_child = child;
        llr->llr_ost_idx = ost_idx;
        llr->llr_lov_idx = lov_idx;
@@ -253,7 +206,7 @@ static void lfsck_layout_assistant_req_fini(const struct lu_env *env,
                        container_of0(lar, struct lfsck_layout_req, llr_lar);
 
        lfsck_object_put(env, llr->llr_child);
-       lfsck_layout_object_put(env, llr->llr_parent);
+       lfsck_assistant_object_put(env, lar->lar_parent);
        OBD_FREE_PTR(llr);
 }
 
@@ -327,7 +280,7 @@ static void lfsck_layout_assistant_sync_failures(const struct lu_env *env,
 
        down_read(&ltds->ltd_rw_sem);
        cfs_foreach_bit(lad->lad_bitmap, idx) {
-               ltd = LTD_TGT(ltds, idx);
+               ltd = lfsck_ltd2tgt(ltds, idx);
                LASSERT(ltd != NULL);
 
                laia->laia_ltd = ltd;
@@ -444,7 +397,7 @@ static int lfsck_layout_verify_header(struct lov_mds_md_v1 *lmm)
        return 0;
 }
 
-#define LFSCK_RBTREE_BITMAP_SIZE       PAGE_CACHE_SIZE
+#define LFSCK_RBTREE_BITMAP_SIZE       PAGE_SIZE
 #define LFSCK_RBTREE_BITMAP_WIDTH      (LFSCK_RBTREE_BITMAP_SIZE << 3)
 #define LFSCK_RBTREE_BITMAP_MASK       (LFSCK_RBTREE_BITMAP_WIDTH - 1)
 
@@ -763,6 +716,8 @@ static void lfsck_layout_le_to_cpu(struct lfsck_layout *des,
                                le64_to_cpu(src->ll_objs_repaired[i]);
        des->ll_objs_skipped = le64_to_cpu(src->ll_objs_skipped);
        des->ll_bitmap_size = le32_to_cpu(src->ll_bitmap_size);
+       fid_le_to_cpu(&des->ll_fid_latest_scanned_phase2,
+                     &src->ll_fid_latest_scanned_phase2);
 }
 
 static void lfsck_layout_cpu_to_le(struct lfsck_layout *des,
@@ -793,6 +748,8 @@ static void lfsck_layout_cpu_to_le(struct lfsck_layout *des,
                                cpu_to_le64(src->ll_objs_repaired[i]);
        des->ll_objs_skipped = cpu_to_le64(src->ll_objs_skipped);
        des->ll_bitmap_size = cpu_to_le32(src->ll_bitmap_size);
+       fid_cpu_to_le(&des->ll_fid_latest_scanned_phase2,
+                     &src->ll_fid_latest_scanned_phase2);
 }
 
 /**
@@ -810,7 +767,7 @@ static int lfsck_layout_load_bitmap(const struct lu_env *env,
        struct dt_object                *obj    = com->lc_obj;
        struct lfsck_assistant_data     *lad    = com->lc_data;
        struct lfsck_layout             *lo     = com->lc_file_ram;
-       cfs_bitmap_t                    *bitmap = lad->lad_bitmap;
+       struct cfs_bitmap                       *bitmap = lad->lad_bitmap;
        loff_t                           pos    = com->lc_file_size;
        ssize_t                          size;
        __u32                            nbits;
@@ -828,7 +785,7 @@ static int lfsck_layout_load_bitmap(const struct lu_env *env,
 
        if (nbits > bitmap->size) {
                __u32 new_bits = bitmap->size;
-               cfs_bitmap_t *new_bitmap;
+               struct cfs_bitmap *new_bitmap;
 
                while (new_bits < nbits)
                        new_bits <<= 1;
@@ -936,7 +893,7 @@ static int lfsck_layout_store(const struct lu_env *env,
        struct lfsck_layout     *lo     = com->lc_file_disk;
        struct thandle          *th;
        struct dt_device        *dev    = lfsck_obj2dev(obj);
-       cfs_bitmap_t            *bitmap = NULL;
+       struct cfs_bitmap       *bitmap = NULL;
        loff_t                   pos;
        ssize_t                  size   = com->lc_file_size;
        __u32                    nbits  = 0;
@@ -1012,6 +969,9 @@ static int lfsck_layout_init(const struct lu_env *env,
        lo->ll_status = LS_INIT;
        down_write(&com->lc_sem);
        rc = lfsck_layout_store(env, com);
+       if (rc == 0 && com->lc_lfsck->li_master)
+               rc = lfsck_load_sub_trace_files(env, com,
+                       &dt_lfsck_layout_dangling_features, LFSCK_LAYOUT, true);
        up_write(&com->lc_sem);
 
        return rc;
@@ -1142,7 +1102,7 @@ stop:
 
 log:
        CDEBUG(D_LFSCK, "%s: layout LFSCK will create LAST_ID for <seq> "
-              LPX64": rc = %d\n",
+              "%#llx: rc = %d\n",
               lfsck_lfsck2name(lfsck), fid_seq(lfsck_dto2fid(obj)), rc);
 
        return rc;
@@ -1179,8 +1139,8 @@ lfsck_layout_lastid_reload(const struct lu_env *env,
                        lo->ll_flags |= LF_CRASHED_LASTID;
 
                        CDEBUG(D_LFSCK, "%s: layout LFSCK finds crashed "
-                              "LAST_ID file (1) for the sequence "LPX64
-                              ", old value "LPU64", known value "LPU64"\n",
+                              "LAST_ID file (1) for the sequence %#llx"
+                              ", old value %llu, known value %llu\n",
                               lfsck_lfsck2name(lfsck), lls->lls_seq,
                               lastid, lls->lls_lastid);
                }
@@ -1213,7 +1173,7 @@ lfsck_layout_lastid_store(const struct lu_env *env,
                        continue;
 
                CDEBUG(D_LFSCK, "%s: layout LFSCK will sync the LAST_ID for "
-                      "<seq> "LPX64" as <oid> "LPU64"\n",
+                      "<seq> %#llx as <oid> %llu\n",
                       lfsck_lfsck2name(lfsck), lls->lls_seq, lls->lls_lastid);
 
                if (bk->lb_param & LPF_DRYRUN) {
@@ -1225,7 +1185,7 @@ lfsck_layout_lastid_store(const struct lu_env *env,
                if (IS_ERR(th)) {
                        rc1 = PTR_ERR(th);
                        CDEBUG(D_LFSCK, "%s: layout LFSCK failed to store "
-                              "the LAST_ID for <seq> "LPX64"(1): rc = %d\n",
+                              "the LAST_ID for <seq> %#llx(1): rc = %d\n",
                               lfsck_lfsck2name(com->lc_lfsck),
                               lls->lls_seq, rc1);
                        continue;
@@ -1256,7 +1216,7 @@ stop:
                if (rc != 0) {
                        rc1 = rc;
                        CDEBUG(D_LFSCK, "%s: layout LFSCK failed to store "
-                              "the LAST_ID for <seq> "LPX64"(2): rc = %d\n",
+                              "the LAST_ID for <seq> %#llx(2): rc = %d\n",
                               lfsck_lfsck2name(com->lc_lfsck),
                               lls->lls_seq, rc1);
                }
@@ -1293,7 +1253,7 @@ lfsck_layout_lastid_load(const struct lu_env *env,
                        lo->ll_flags |= LF_CRASHED_LASTID;
 
                        CDEBUG(D_LFSCK, "%s: layout LFSCK cannot find the "
-                              "LAST_ID file for sequence "LPX64"\n",
+                              "LAST_ID file for sequence %#llx\n",
                               lfsck_lfsck2name(lfsck), lls->lls_seq);
 
                        if (OBD_FAIL_CHECK(OBD_FAIL_LFSCK_DELAY4) &&
@@ -1336,7 +1296,7 @@ lfsck_layout_lastid_load(const struct lu_env *env,
                        lo->ll_flags |= LF_CRASHED_LASTID;
 
                        CDEBUG(D_LFSCK, "%s: layout LFSCK finds invalid "
-                              "LAST_ID file for the sequence "LPX64
+                              "LAST_ID file for the sequence %#llx"
                               ": rc = %d\n",
                               lfsck_lfsck2name(lfsck), lls->lls_seq, rc);
                }
@@ -1370,7 +1330,7 @@ static void lfsck_layout_record_failure(const struct lu_env *env,
                lo->ll_pos_first_inconsistent = cookie;
 
                CDEBUG(D_LFSCK, "%s: layout LFSCK hit first non-repaired "
-                      "inconsistency at the pos ["LPU64"]\n",
+                      "inconsistency at the pos [%llu]\n",
                       lfsck_lfsck2name(lfsck),
                       lo->ll_pos_first_inconsistent);
        }
@@ -1385,7 +1345,7 @@ static int lfsck_layout_double_scan_result(const struct lu_env *env,
 
        down_write(&com->lc_sem);
        lo->ll_run_time_phase2 += cfs_duration_sec(cfs_time_current() +
-                               HALF_SEC - lfsck->li_time_last_checkpoint);
+                                 HALF_SEC - com->lc_time_last_checkpoint);
        lo->ll_time_last_checkpoint = cfs_time_current_sec();
        lo->ll_objs_checked_phase2 += com->lc_new_checked;
 
@@ -1429,12 +1389,122 @@ static int lfsck_layout_trans_stop(const struct lu_env *env,
 {
        int rc;
 
+       /* XXX: If there is something worng or it needs to repair nothing,
+        *      then notify the lower to stop the modification. Currently,
+        *      we use th_result for such purpose, that may be replaced by
+        *      some rollback mechanism in the future. */
        handle->th_result = result;
        rc = dt_trans_stop(env, dev, handle);
-       if (rc > 0)
-               rc = 0;
-       else if (rc == 0)
-               rc = 1;
+       if (result != 0)
+               return result > 0 ? 0 : result;
+
+       return rc == 0 ? 1 : rc;
+}
+
+static int lfsck_layout_ins_dangling_rec(const struct lu_env *env,
+                                        struct lfsck_component *com,
+                                        const struct lu_fid *pfid,
+                                        const struct lu_fid *cfid,
+                                        __u32 ea_off, __u32 ost_idx)
+{
+       struct lu_fid *key = &lfsck_env_info(env)->lti_fid3;
+       struct lu_fid *rec = &lfsck_env_info(env)->lti_fid4;
+       struct dt_device *dev;
+       struct dt_object *obj;
+       struct thandle *th = NULL;
+       int idx;
+       int rc = 0;
+       ENTRY;
+
+       idx = lfsck_sub_trace_file_fid2idx(pfid);
+       obj = com->lc_sub_trace_objs[idx].lsto_obj;
+       dev = lfsck_obj2dev(obj);
+       fid_cpu_to_be(key, pfid);
+       key->f_ver = cpu_to_be32(ea_off);
+       fid_cpu_to_be(rec, cfid);
+       rec->f_ver = cpu_to_be32(ost_idx);
+
+       mutex_lock(&com->lc_sub_trace_objs[idx].lsto_mutex);
+
+       th = dt_trans_create(env, dev);
+       if (IS_ERR(th))
+               GOTO(unlock, rc = PTR_ERR(th));
+
+       rc = dt_declare_insert(env, obj,
+                              (const struct dt_rec *)rec,
+                              (const struct dt_key *)key, th);
+       if (rc)
+               GOTO(unlock, rc);
+
+       rc = dt_trans_start_local(env, dev, th);
+       if (rc)
+               GOTO(unlock, rc);
+
+       rc = dt_insert(env, obj, (const struct dt_rec *)rec,
+                      (const struct dt_key *)key, th, 1);
+
+       GOTO(unlock, rc);
+
+unlock:
+       if (th != NULL && !IS_ERR(th))
+               dt_trans_stop(env, dev, th);
+
+       mutex_unlock(&com->lc_sub_trace_objs[idx].lsto_mutex);
+
+       CDEBUG(D_LFSCK, "%s: insert the paris "DFID" => "DFID", ea_off = %u, "
+              "ost_idx = %u, into the trace file for further dangling check: "
+              "rc = %d\n", lfsck_lfsck2name(com->lc_lfsck),
+              PFID(pfid), PFID(cfid), ea_off, ost_idx, rc);
+
+       return rc;
+}
+
+static int lfsck_layout_del_dangling_rec(const struct lu_env *env,
+                                        struct lfsck_component *com,
+                                        const struct lu_fid *fid,
+                                        __u32 ea_off)
+{
+       struct lu_fid *key = &lfsck_env_info(env)->lti_fid3;
+       struct dt_device *dev;
+       struct dt_object *obj;
+       struct thandle *th = NULL;
+       int idx;
+       int rc = 0;
+       ENTRY;
+
+       idx = lfsck_sub_trace_file_fid2idx(fid);
+       obj = com->lc_sub_trace_objs[idx].lsto_obj;
+       dev = lfsck_obj2dev(obj);
+       fid_cpu_to_be(key, fid);
+       key->f_ver = cpu_to_be32(ea_off);
+
+       mutex_lock(&com->lc_sub_trace_objs[idx].lsto_mutex);
+
+       th = dt_trans_create(env, dev);
+       if (IS_ERR(th))
+               GOTO(unlock, rc = PTR_ERR(th));
+
+       rc = dt_declare_delete(env, obj, (const struct dt_key *)key, th);
+       if (rc)
+               GOTO(unlock, rc);
+
+       rc = dt_trans_start_local(env, dev, th);
+       if (rc)
+               GOTO(unlock, rc);
+
+       rc = dt_delete(env, obj, (const struct dt_key *)key, th);
+
+       GOTO(unlock, rc);
+
+unlock:
+       if (th != NULL && !IS_ERR(th))
+               dt_trans_stop(env, dev, th);
+
+       mutex_unlock(&com->lc_sub_trace_objs[idx].lsto_mutex);
+
+       CDEBUG(D_LFSCK, "%s: delete the dangling record for "DFID
+              ", ea_off = %u from the trace file: rc = %d\n",
+              lfsck_lfsck2name(com->lc_lfsck), PFID(fid), ea_off, rc);
 
        return rc;
 }
@@ -1751,7 +1821,7 @@ static int lfsck_layout_recreate_parent(const struct lu_env *env,
        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 lu_attr                  *la     = &info->lti_la2;
        struct dt_object_format         *dof    = &info->lti_dof;
        struct lfsck_instance           *lfsck  = com->lc_lfsck;
        struct lu_fid                   *pfid   = &rec->lor_fid;
@@ -1849,13 +1919,9 @@ again:
        if (rc != -ENOENT)
                GOTO(unlock, rc);
 
-       rc = linkea_data_new(&ldata,
-                            &lfsck_env_info(env)->lti_linkea_buf);
-       if (rc != 0)
-               GOTO(unlock, rc);
-
        pname = lfsck_name_get_const(env, name, strlen(name));
-       rc = linkea_add_buf(&ldata, pname, lfsck_dto2fid(lfsck->li_lpf_obj));
+       rc = linkea_links_new(&ldata, &lfsck_env_info(env)->lti_linkea_buf,
+                             pname, lfsck_dto2fid(lfsck->li_lpf_obj));
        if (rc != 0)
                GOTO(unlock, rc);
 
@@ -2002,7 +2068,7 @@ static int lfsck_layout_slave_conditional_destroy(const struct lu_env *env,
 {
        struct lfsck_thread_info        *info   = lfsck_env_info(env);
        struct lu_attr                  *la     = &info->lti_la;
-       ldlm_policy_data_t              *policy = &info->lti_policy;
+       union ldlm_policy_data          *policy = &info->lti_policy;
        struct ldlm_res_id              *resid  = &info->lti_resid;
        struct lfsck_instance           *lfsck  = com->lc_lfsck;
        struct dt_device                *dev    = lfsck->li_bottom;
@@ -2134,6 +2200,11 @@ static int lfsck_layout_conflict_create(const struct lu_env *env,
        int                       rc            = 0;
        ENTRY;
 
+       while (CFS_FAIL_TIMEOUT(OBD_FAIL_LFSCK_DELAY3, cfs_fail_val)) {
+               if (unlikely(!thread_is_running(&com->lc_lfsck->li_thread)))
+                       RETURN(0);
+       }
+
        ostid_le_to_cpu(&slot->l_ost_oi, oi);
        rc = ostid_to_fid(cfid2, oi, ost_idx2);
        if (rc != 0)
@@ -2526,6 +2597,12 @@ static int lfsck_layout_scan_orphan_one(const struct lu_env *env,
        if (!S_ISREG(lu_object_attr(&parent->do_lu)))
                GOTO(put, rc = -EISDIR);
 
+       /* The orphan OST-object claims to be the parent's stripe, then
+        * related dangling record in the trace file is meaningless. */
+       rc = lfsck_layout_del_dangling_rec(env, com, pfid, ea_off);
+       if (rc != 0 && rc != -ENOENT)
+               GOTO(put, rc);
+
        rc = lfsck_layout_recreate_lovea(env, com, ltd, rec, parent, cfid,
                                         ltd->ltd_index, ea_off);
 
@@ -2591,7 +2668,8 @@ static int lfsck_layout_scan_orphan(const struct lu_env *env,
        if (unlikely(IS_ERR(obj)))
                GOTO(log, rc = PTR_ERR(obj));
 
-       rc = obj->do_ops->do_index_try(env, obj, &dt_lfsck_orphan_features);
+       rc = obj->do_ops->do_index_try(env, obj,
+                                      &dt_lfsck_layout_orphan_features);
        if (rc != 0)
                GOTO(put, rc);
 
@@ -2658,70 +2736,80 @@ log:
        return rc > 0 ? 0 : rc;
 }
 
-/* For the MDT-object with dangling reference, we need to repare the
- * inconsistency according to the LFSCK sponsor's requirement:
+/**
+ * Repair the MDT-object with dangling LOV EA reference.
+ *
+ * we need to repair the inconsistency according to the users' requirement:
  *
  * 1) Keep the inconsistency there and report the inconsistency case,
  *    then give the chance to the application to find related issues,
  *    and the users can make the decision about how to handle it with
  *    more human knownledge. (by default)
  *
- * 2) Re-create the missing OST-object with the FID/owner information. */
-static int lfsck_layout_repair_dangling(const struct lu_env *env,
-                                       struct lfsck_component *com,
-                                       struct dt_object *parent,
-                                       struct lfsck_layout_req *llr,
-                                       const struct lu_attr *pla)
+ * 2) Re-create the missing OST-object with the FID/owner information.
+ *
+ * \param[in] env      pointer to the thread context
+ * \param[in] com      the layout LFSCK component
+ * \param[in] parent   the MDT-object with dangling LOV EA reference
+ * \param[in] child    the OST-object to be created
+ * \param[in] ea_off   the offset of the OST-object in the LOV EA
+ * \param[in] ost_idx  the index of OST on which the OST-object resides
+ *
+ * \retval             +1 for repair successfully
+ * \retval             0 for did nothing
+ * \retval             negative error number on failure
+ */
+static int __lfsck_layout_repair_dangling(const struct lu_env *env,
+                                         struct lfsck_component *com,
+                                         struct dt_object *parent,
+                                         struct dt_object *child,
+                                         __u32 ea_off, __u32 ost_idx, bool log)
 {
-       struct lfsck_thread_info        *info   = lfsck_env_info(env);
-       struct filter_fid               *pfid   = &info->lti_new_pfid;
-       struct dt_object_format         *dof    = &info->lti_dof;
-       struct lu_attr                  *cla    = &info->lti_la2;
-       struct dt_object                *child  = llr->llr_child;
-       struct dt_device                *dev    = lfsck_obj2dev(child);
-       const struct lu_fid             *tfid   = lu_object_fid(&parent->do_lu);
-       struct thandle                  *handle;
-       struct lu_buf                   *buf;
-       struct lustre_handle             lh     = { 0 };
-       int                              rc;
-       bool                             create;
+       struct lfsck_thread_info *info = lfsck_env_info(env);
+       struct filter_fid *ff = &info->lti_new_pfid;
+       struct dt_object_format *dof = &info->lti_dof;
+       struct lu_attr *la = &info->lti_la;
+       struct lfsck_instance *lfsck = com->lc_lfsck;
+       struct dt_device *dev = lfsck_obj2dev(child);
+       const struct lu_fid *pfid = lfsck_dto2fid(parent);
+       const struct lu_fid *cfid = lfsck_dto2fid(child);
+       struct thandle *handle;
+       struct lu_buf *buf;
+       struct lustre_handle lh = { 0 };
+       int rc;
        ENTRY;
 
-       if (com->lc_lfsck->li_bookmark_ram.lb_param & LPF_CREATE_OSTOBJ)
-               create = true;
-       else
-               create = false;
-
-       if (!create)
+       if (!(lfsck->li_bookmark_ram.lb_param & LPF_CREATE_OSTOBJ))
                GOTO(log, rc = 1);
 
-       memset(cla, 0, sizeof(*cla));
-       cla->la_uid = pla->la_uid;
-       cla->la_gid = pla->la_gid;
-       cla->la_mode = S_IFREG | 0666;
-       cla->la_valid = LA_TYPE | LA_MODE | LA_UID | LA_GID |
-                       LA_ATIME | LA_MTIME | LA_CTIME;
-       memset(dof, 0, sizeof(*dof));
-
-       rc = lfsck_ibits_lock(env, com->lc_lfsck, parent, &lh,
+       rc = lfsck_ibits_lock(env, lfsck, parent, &lh,
                              MDS_INODELOCK_LAYOUT | MDS_INODELOCK_XATTR,
                              LCK_EX);
        if (rc != 0)
                GOTO(log, rc);
 
-       pfid->ff_parent.f_seq = cpu_to_le64(tfid->f_seq);
-       pfid->ff_parent.f_oid = cpu_to_le32(tfid->f_oid);
+       rc = dt_attr_get(env, parent, la);
+       if (rc != 0)
+               GOTO(unlock1, rc);
+
+       la->la_mode = S_IFREG | 0666;
+       la->la_atime = la->la_mtime = la->la_ctime = 0;
+       la->la_valid = LA_TYPE | LA_MODE | LA_UID | LA_GID |
+                      LA_ATIME | LA_MTIME | LA_CTIME;
+       memset(dof, 0, sizeof(*dof));
+       ff->ff_parent.f_seq = cpu_to_le64(pfid->f_seq);
+       ff->ff_parent.f_oid = cpu_to_le32(pfid->f_oid);
        /* Currently, the filter_fid::ff_parent::f_ver is not the real parent
         * MDT-object's FID::f_ver, instead it is the OST-object index in its
         * parent MDT-object's layout EA. */
-       pfid->ff_parent.f_stripe_idx = cpu_to_le32(llr->llr_lov_idx);
-       buf = lfsck_buf_get(env, pfid, sizeof(struct filter_fid));
+       ff->ff_parent.f_stripe_idx = cpu_to_le32(ea_off);
+       buf = lfsck_buf_get(env, ff, sizeof(struct filter_fid));
 
        handle = dt_trans_create(env, dev);
        if (IS_ERR(handle))
                GOTO(unlock1, rc = PTR_ERR(handle));
 
-       rc = dt_declare_create(env, child, cla, NULL, dof, handle);
+       rc = dt_declare_create(env, child, la, NULL, dof, handle);
        if (rc != 0)
                GOTO(stop, rc);
 
@@ -2736,9 +2824,55 @@ static int lfsck_layout_repair_dangling(const struct lu_env *env,
 
        dt_read_lock(env, parent, 0);
        if (unlikely(lfsck_is_dead_obj(parent)))
-               GOTO(unlock2, rc = 1);
+               GOTO(unlock2, rc = 0);
+
+       if (lfsck->li_bookmark_ram.lb_param & LPF_DELAY_CREATE_OSTOBJ) {
+               struct ost_id *oi = &info->lti_oi;
+               struct lu_fid *tfid = &info->lti_fid2;
+               struct lu_buf *lovea = &info->lti_big_buf;
+               struct lov_mds_md_v1 *lmm;
+               struct lov_ost_data_v1 *objs;
+               __u32 magic;
+               int count;
+               int idx2;
+
+               rc = lfsck_layout_get_lovea(env, parent, lovea);
+               if (rc <= 0)
+                       GOTO(unlock2, rc);
 
-       rc = dt_create(env, child, cla, NULL, dof, handle);
+               lmm = lovea->lb_buf;
+               rc = lfsck_layout_verify_header(lmm);
+               if (unlikely(rc != 0))
+                       GOTO(unlock2, rc);
+
+               count = le16_to_cpu(lmm->lmm_stripe_count);
+               /* Someone changed the LOV EA, do nothing. */
+               if (count <= ea_off)
+                       GOTO(unlock2, rc = 0);
+
+               /* Currently, we only support LOV_MAGIC_V1/LOV_MAGIC_V3 which
+                * has been verified in lfsck_layout_verify_header() already.
+                * If some new magic introduced in the future, then the layout
+                * LFSCK needs to be updated also. */
+               magic = le32_to_cpu(lmm->lmm_magic);
+               if (magic == LOV_MAGIC_V1) {
+                       objs = &lmm->lmm_objects[ea_off];
+               } else {
+                       LASSERT(magic == LOV_MAGIC_V3);
+
+                       objs = &((struct lov_mds_md_v3 *)lmm)->\
+                                                       lmm_objects[ea_off];
+               }
+
+               ostid_le_to_cpu(&objs->l_ost_oi, oi);
+               idx2 = le32_to_cpu(objs->l_ost_idx);
+               rc = ostid_to_fid(tfid, oi, idx2);
+               /* Someone changed the LOV EA, do nothing. */
+               if (rc != 0 || !lu_fid_eq(tfid, cfid))
+                       GOTO(unlock2, rc);
+       }
+
+       rc = dt_create(env, child, la, NULL, dof, handle);
        if (rc != 0)
                GOTO(unlock2, rc);
 
@@ -2757,14 +2891,90 @@ unlock1:
        lfsck_ibits_unlock(&lh, LCK_EX);
 
 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);
+       if (rc != 0 && log)
+               CDEBUG(D_LFSCK, "%s: layout LFSCK assistant found "
+                      "dangling reference for: parent "DFID", child "
+                      DFID", ea_off %u, ost_idx %u, %s: rc = %d\n",
+                      lfsck_lfsck2name(lfsck), PFID(pfid), PFID(cfid),
+                      ea_off, ost_idx,
+                      (lfsck->li_bookmark_ram.lb_param & LPF_CREATE_OSTOBJ) ?
+                               "Create the lost OST-object as required" :
+                               "Keep the MDT-object there by default", rc);
+
+       return rc;
+}
+
+/**
+ * Repair the MDT-object with dangling LOV EA reference.
+ *
+ * Prepare parameters and call __lfsck_layout_repair_dangling()
+ * to repair the dangling LOV EA reference.
+ *
+ * \param[in] env      pointer to the thread context
+ * \param[in] com      the layout LFSCK component
+ * \param[in] pfid     the MDT-object's FID
+ * \param[in] cfid     the FID for the OST-object to be created
+ * \param[in] ea_off   the offset of the OST-object in the LOV EA
+ * \param[in] ost_idx  the index of OST on which the OST-object resides
+ *
+ * \retval             +1 for repair successfully
+ * \retval             0 for did nothing
+ * \retval             negative error number on failure
+ */
+static int lfsck_layout_repair_dangling(const struct lu_env *env,
+                                       struct lfsck_component *com,
+                                       const struct lu_fid *pfid,
+                                       const struct lu_fid *cfid,
+                                       __u32 ea_off, __u32 ost_idx)
+{
+       struct lfsck_instance *lfsck = com->lc_lfsck;
+       struct dt_object *parent = NULL;
+       struct dt_object *child = NULL;
+       struct lfsck_tgt_desc *ltd;
+       int rc;
+       ENTRY;
+
+       parent = lfsck_object_find_bottom(env, lfsck, pfid);
+       if (IS_ERR(parent))
+               GOTO(log, rc = PTR_ERR(parent));
+
+       /* The MDT-object has been removed. */
+       if (dt_object_exists(parent) == 0)
+               GOTO(log, rc = 0);
+
+       ltd = lfsck_ltd2tgt(&lfsck->li_ost_descs, ost_idx);
+       if (unlikely(ltd == NULL))
+               GOTO(log, rc = -ENODEV);
+
+       child = lfsck_object_find_by_dev(env, ltd->ltd_tgt, cfid);
+       if (IS_ERR(child))
+               GOTO(log, rc = PTR_ERR(child));
+
+       /* The OST-object has been created. */
+       if (unlikely(dt_object_exists(child) != 0))
+               GOTO(log, rc = 0);
+
+       rc = __lfsck_layout_repair_dangling(env, com, parent, child,
+                                           ea_off, ost_idx, false);
+
+       GOTO(log, rc);
+
+log:
+       if (child != NULL && !IS_ERR(child))
+               lfsck_object_put(env, child);
+
+       if (parent != NULL && !IS_ERR(parent))
+               lfsck_object_put(env, parent);
+
+       if (rc != 0)
+               CDEBUG(D_LFSCK, "%s: layout LFSCK assistant found "
+                      "dangling reference for: parent "DFID", child "
+                      DFID", ea_off %u, ost_idx %u, %s: rc = %d\n",
+                      lfsck_lfsck2name(lfsck), PFID(pfid), PFID(cfid),
+                      ea_off, ost_idx,
+                      (lfsck->li_bookmark_ram.lb_param & LPF_CREATE_OSTOBJ) ?
+                               "Create the lost OST-object as required" :
+                               "Keep the MDT-object there by default", rc);
 
        return rc;
 }
@@ -2776,11 +2986,10 @@ static int lfsck_layout_repair_unmatched_pair(const struct lu_env *env,
                                              struct lfsck_component *com,
                                              struct dt_object *parent,
                                              struct lfsck_layout_req *llr,
-                                             const struct lu_attr *pla)
+                                             struct lu_attr *la)
 {
        struct lfsck_thread_info        *info   = lfsck_env_info(env);
        struct filter_fid               *pfid   = &info->lti_new_pfid;
-       struct lu_attr                  *tla    = &info->lti_la3;
        struct dt_object                *child  = llr->llr_child;
        struct dt_device                *dev    = lfsck_obj2dev(child);
        const struct lu_fid             *tfid   = lu_object_fid(&parent->do_lu);
@@ -2812,10 +3021,12 @@ static int lfsck_layout_repair_unmatched_pair(const struct lu_env *env,
        if (rc != 0)
                GOTO(stop, rc);
 
-       tla->la_valid = LA_UID | LA_GID;
-       tla->la_uid = pla->la_uid;
-       tla->la_gid = pla->la_gid;
-       rc = dt_declare_attr_set(env, child, tla, handle);
+       rc = dt_attr_get(env, parent, la);
+       if (rc != 0)
+               GOTO(stop, rc);
+
+       la->la_valid = LA_UID | LA_GID;
+       rc = dt_declare_attr_set(env, child, la, handle);
        if (rc != 0)
                GOTO(stop, rc);
 
@@ -2832,12 +3043,12 @@ static int lfsck_layout_repair_unmatched_pair(const struct lu_env *env,
                GOTO(unlock2, rc);
 
        /* Get the latest parent's owner. */
-       rc = dt_attr_get(env, parent, tla);
+       rc = dt_attr_get(env, parent, la);
        if (rc != 0)
                GOTO(unlock2, rc);
 
-       tla->la_valid = LA_UID | LA_GID;
-       rc = dt_attr_set(env, child, tla, handle);
+       la->la_valid = LA_UID | LA_GID;
+       rc = dt_attr_set(env, child, la, handle);
 
        GOTO(unlock2, rc);
 
@@ -2851,12 +3062,16 @@ unlock1:
        lfsck_ibits_unlock(&lh, LCK_EX);
 
 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);
+       if (rc != 0)
+               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,
+                      la->la_uid, la->la_gid, rc);
 
        return rc;
 }
@@ -2876,7 +3091,7 @@ static int lfsck_layout_repair_multiple_references(const struct lu_env *env,
        struct dt_object_format         *dof    = &info->lti_dof;
        struct ost_id                   *oi     = &info->lti_oi;
        struct lfsck_instance           *lfsck  = com->lc_lfsck;
-       struct dt_device                *dev    = lfsck->li_bottom;
+       struct dt_device                *dev;
        struct lu_device                *d      =
                                &lfsck_obj2dev(llr->llr_child)->dd_lu_dev;
        struct lu_object                *o;
@@ -2919,9 +3134,14 @@ static int lfsck_layout_repair_multiple_references(const struct lu_env *env,
 
        child = container_of(n, struct dt_object, do_lu);
        memset(hint, 0, sizeof(*hint));
+       rc = dt_attr_get(env, parent, la);
+       if (rc != 0)
+               GOTO(log, rc);
+
        la->la_valid = LA_UID | LA_GID;
        memset(dof, 0, sizeof(*dof));
 
+       dev = lfsck_obj2dev(child);
        handle = dt_trans_create(env, dev);
        if (IS_ERR(handle))
                GOTO(log, rc = PTR_ERR(handle));
@@ -3030,10 +3250,12 @@ log:
        if (child != NULL)
                lfsck_object_put(env, child);
 
-       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(lfsck), PFID(pfid),
-              llr->llr_ost_idx, llr->llr_lov_idx, la->la_uid, la->la_gid, rc);
+       if (rc != 0)
+               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(lfsck), PFID(pfid), llr->llr_ost_idx,
+                      llr->llr_lov_idx, la->la_uid, la->la_gid, rc);
 
        return rc;
 }
@@ -3046,23 +3268,24 @@ static int lfsck_layout_repair_owner(const struct lu_env *env,
                                     struct lfsck_component *com,
                                     struct dt_object *parent,
                                     struct lfsck_layout_req *llr,
-                                    struct lu_attr *pla)
+                                    struct lu_attr *pla,
+                                    const struct lu_attr *cla)
 {
        struct lfsck_thread_info        *info   = lfsck_env_info(env);
-       struct lu_attr                  *tla    = &info->lti_la3;
+       struct lu_attr                  *tla    = &info->lti_la2;
        struct dt_object                *child  = llr->llr_child;
        struct dt_device                *dev    = lfsck_obj2dev(child);
        struct thandle                  *handle;
        int                              rc;
        ENTRY;
 
+       tla->la_uid = pla->la_uid;
+       tla->la_gid = pla->la_gid;
+       tla->la_valid = LA_UID | LA_GID;
        handle = dt_trans_create(env, dev);
        if (IS_ERR(handle))
                GOTO(log, rc = PTR_ERR(handle));
 
-       tla->la_uid = pla->la_uid;
-       tla->la_gid = pla->la_gid;
-       tla->la_valid = LA_UID | LA_GID;
        rc = dt_declare_attr_set(env, child, tla, handle);
        if (rc != 0)
                GOTO(stop, rc);
@@ -3077,17 +3300,16 @@ static int lfsck_layout_repair_owner(const struct lu_env *env,
                GOTO(unlock, rc = 1);
 
        /* Get the latest parent's owner. */
-       rc = dt_attr_get(env, parent, tla);
+       rc = dt_attr_get(env, parent, pla);
        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 ||
                     tla->la_gid != pla->la_gid))
-               GOTO(unlock, rc = 1);
-
-       tla->la_valid = LA_UID | LA_GID;
-       rc = dt_attr_set(env, child, tla, handle);
+               rc = 1;
+       else
+               rc = dt_attr_set(env, child, tla, handle);
 
        GOTO(unlock, rc);
 
@@ -3098,12 +3320,15 @@ 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);
+       if (rc != 0)
+               CDEBUG(D_LFSCK, "%s: layout LFSCK assistant repaired "
+                      "inconsistent file owner for: parent "DFID", child "DFID
+                      ", OST-index %u, stripe-index %u, old owner %u/%u, "
+                      "new 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,
+                      cla->la_uid, cla->la_gid, tla->la_uid, tla->la_gid, rc);
 
        return rc;
 }
@@ -3112,10 +3337,9 @@ log:
  * MDT-object (@parent) via the XATTR_NAME_FID xattr (@pfid). */
 static int lfsck_layout_check_parent(const struct lu_env *env,
                                     struct lfsck_component *com,
-                                    struct dt_object *parent,
+                                    struct lfsck_assistant_object *lso,
                                     const struct lu_fid *pfid,
                                     const struct lu_fid *cfid,
-                                    const struct lu_attr *pla,
                                     const struct lu_attr *cla,
                                     struct lfsck_layout_req *llr,
                                     struct lu_buf *lov_ea, __u32 idx)
@@ -3132,24 +3356,11 @@ static int lfsck_layout_check_parent(const struct lu_env *env,
        __u16                            count;
        ENTRY;
 
-       if (fid_is_zero(pfid)) {
-               /* client never wrote. */
-               if (cla->la_size == 0 && cla->la_blocks == 0) {
-                       if (unlikely(cla->la_uid != pla->la_uid ||
-                                    cla->la_gid != pla->la_gid))
-                               RETURN (LLIT_INCONSISTENT_OWNER);
-
-                       RETURN(0);
-               }
-
-               RETURN(LLIT_UNMATCHED_PAIR);
-       }
-
        if (unlikely(!fid_is_sane(pfid)))
                RETURN(LLIT_UNMATCHED_PAIR);
 
-       if (lu_fid_eq(pfid, lu_object_fid(&parent->do_lu))) {
-               if (llr->llr_lov_idx == idx)
+       if (lu_fid_eq(pfid, &lso->lso_fid)) {
+               if (likely(llr->llr_lov_idx == idx))
                        RETURN(0);
 
                RETURN(LLIT_UNMATCHED_PAIR);
@@ -3159,11 +3370,8 @@ static int lfsck_layout_check_parent(const struct lu_env *env,
        if (IS_ERR(tobj))
                RETURN(PTR_ERR(tobj));
 
-       if (dt_object_exists(tobj) == 0 ||
-           lfsck_is_dead_obj(tobj))
-               GOTO(out, rc = LLIT_UNMATCHED_PAIR);
-
-       if (!S_ISREG(lfsck_object_type(tobj)))
+       if (dt_object_exists(tobj) == 0 || lfsck_is_dead_obj(tobj) ||
+           !S_ISREG(lfsck_object_type(tobj)))
                GOTO(out, rc = LLIT_UNMATCHED_PAIR);
 
        /* Load the tobj's layout EA, in spite of it is a local MDT-object or
@@ -3273,15 +3481,16 @@ static int lfsck_layout_assistant_handler_p1(const struct lu_env *env,
 {
        struct lfsck_layout_req              *llr    =
                        container_of0(lar, struct lfsck_layout_req, llr_lar);
+       struct lfsck_assistant_object        *lso    = lar->lar_parent;
        struct lfsck_layout                  *lo     = com->lc_file_ram;
        struct lfsck_thread_info             *info   = lfsck_env_info(env);
        struct filter_fid_old                *pea    = &info->lti_old_pfid;
        struct lu_fid                        *pfid   = &info->lti_fid;
        struct lu_buf                         buf    = { NULL };
-       struct dt_object                     *parent;
+       struct dt_object                     *parent = NULL;
        struct dt_object                     *child  = llr->llr_child;
-       struct lu_attr                       *pla    = &info->lti_la;
-       struct lu_attr                       *cla    = &info->lti_la2;
+       struct lu_attr                       *pla    = &lso->lso_attr;
+       struct lu_attr                       *cla    = &info->lti_la;
        struct lfsck_instance                *lfsck  = com->lc_lfsck;
        struct lfsck_bookmark                *bk     = &lfsck->li_bookmark_ram;
        enum lfsck_layout_inconsistency_type  type   = LLIT_NONE;
@@ -3289,21 +3498,19 @@ static int lfsck_layout_assistant_handler_p1(const struct lu_env *env,
        int                                   rc;
        ENTRY;
 
-       parent = lfsck_object_find_bottom(env, lfsck, &lar->lar_fid);
-       if (IS_ERR(parent))
-               RETURN(PTR_ERR(parent));
-
-       if (unlikely(lfsck_is_dead_obj(parent)))
-               GOTO(put_parent, rc = 0);
+       if (lso->lso_dead)
+               RETURN(0);
 
-       rc = dt_attr_get(env, parent, pla);
-       if (rc != 0)
-               GOTO(out, rc);
+       CFS_FAIL_TIMEOUT(OBD_FAIL_LFSCK_ASSISTANT_DIRECT, cfs_fail_val);
 
        rc = dt_attr_get(env, child, cla);
        if (rc == -ENOENT) {
-               if (unlikely(lfsck_is_dead_obj(parent)))
-                       GOTO(put_parent, rc = 0);
+               parent = lfsck_assistant_object_load(env, lfsck, lso);
+               if (IS_ERR(parent)) {
+                       rc = PTR_ERR(parent);
+
+                       RETURN(rc == -ENOENT ? 0 : rc);
+               }
 
                type = LLIT_DANGLING;
                goto repair;
@@ -3314,7 +3521,7 @@ static int lfsck_layout_assistant_handler_p1(const struct lu_env *env,
 
        lfsck_buf_init(&buf, pea, sizeof(struct filter_fid_old));
        rc = dt_xattr_get(env, child, &buf, XATTR_NAME_FID);
-       if (unlikely(rc >= 0 && rc != sizeof(struct filter_fid_old) &&
+       if (unlikely(rc > 0 && rc != sizeof(struct filter_fid_old) &&
                     rc != sizeof(struct filter_fid))) {
                type = LLIT_UNMATCHED_PAIR;
                goto repair;
@@ -3323,20 +3530,18 @@ static int lfsck_layout_assistant_handler_p1(const struct lu_env *env,
        if (rc < 0 && rc != -ENODATA)
                GOTO(out, rc);
 
-       if (rc == -ENODATA) {
-               fid_zero(pfid);
-       } else {
-               fid_le_to_cpu(pfid, &pea->ff_parent);
-               /* Currently, the filter_fid::ff_parent::f_ver is not the
-                * real parent MDT-object's FID::f_ver, instead it is the
-                * OST-object index in its parent MDT-object's layout EA. */
-               idx = pfid->f_stripe_idx;
-               pfid->f_ver = 0;
-       }
+       if (rc == 0 || rc == -ENODATA)
+               GOTO(check_owner, rc = 0);
 
-       rc = lfsck_layout_check_parent(env, com, parent, pfid,
+       fid_le_to_cpu(pfid, &pea->ff_parent);
+       /* Currently, the filter_fid::ff_parent::f_ver is not the
+        * real parent MDT-object's FID::f_ver, instead it is the
+        * OST-object index in its parent MDT-object's layout EA. */
+       idx = pfid->f_stripe_idx;
+       pfid->f_ver = 0;
+       rc = lfsck_layout_check_parent(env, com, lso, pfid,
                                       lu_object_fid(&child->do_lu),
-                                      pla, cla, llr, &buf, idx);
+                                      cla, llr, &buf, idx);
        if (rc > 0) {
                type = rc;
                goto repair;
@@ -3345,6 +3550,9 @@ static int lfsck_layout_assistant_handler_p1(const struct lu_env *env,
        if (rc < 0)
                GOTO(out, rc);
 
+check_owner:
+       /* Someone may has changed the owner after the parent attr pre-loaded.
+        * It can be handled later inside the lfsck_layout_repair_owner(). */
        if (unlikely(cla->la_uid != pla->la_uid ||
                     cla->la_gid != pla->la_gid)) {
                type = LLIT_INCONSISTENT_OWNER;
@@ -3352,16 +3560,34 @@ static int lfsck_layout_assistant_handler_p1(const struct lu_env *env,
        }
 
 repair:
-       if (bk->lb_param & LPF_DRYRUN) {
-               if (type != LLIT_NONE)
-                       GOTO(out, rc = 1);
-               else
-                       GOTO(out, rc = 0);
+       if (type == LLIT_NONE)
+               GOTO(out, rc = 0);
+
+       if (bk->lb_param & LPF_DRYRUN)
+               GOTO(out, rc = 1);
+
+       if (parent == NULL) {
+               parent = lfsck_assistant_object_load(env, lfsck, lso);
+               if (IS_ERR(parent)) {
+                       rc = PTR_ERR(parent);
+
+                       if (rc == -ENOENT)
+                               RETURN(0);
+
+                       GOTO(out, rc);
+               }
        }
 
        switch (type) {
        case LLIT_DANGLING:
-               rc = lfsck_layout_repair_dangling(env, com, parent, llr, pla);
+               if (bk->lb_param & LPF_DELAY_CREATE_OSTOBJ)
+                       rc = lfsck_layout_ins_dangling_rec(env, com,
+                               lfsck_dto2fid(parent), lfsck_dto2fid(child),
+                               llr->llr_lov_idx, llr->llr_ost_idx);
+               else
+                       rc = __lfsck_layout_repair_dangling(env, com, parent,
+                                       llr->llr_child, llr->llr_lov_idx,
+                                       llr->llr_ost_idx, true);
                break;
        case LLIT_UNMATCHED_PAIR:
                rc = lfsck_layout_repair_unmatched_pair(env, com, parent,
@@ -3372,7 +3598,7 @@ repair:
                                                             llr, pla, &buf);
                break;
        case LLIT_INCONSISTENT_OWNER:
-               rc = lfsck_layout_repair_owner(env, com, parent, llr, pla);
+               rc = lfsck_layout_repair_owner(env, com, parent, llr, pla, cla);
                break;
        default:
                rc = 0;
@@ -3402,7 +3628,8 @@ out:
                } else {
                        lfsck_layout_record_failure(env, lfsck, lo);
                }
-       } else if (rc > 0) {
+       } else if (rc > 0 && (type != LLIT_DANGLING ||
+                             !(bk->lb_param & LPF_DELAY_CREATE_OSTOBJ))) {
                LASSERTF(type > LLIT_NONE && type <= LLIT_MAX,
                         "unknown type = %d\n", type);
 
@@ -3415,8 +3642,136 @@ out:
        }
        up_write(&com->lc_sem);
 
-put_parent:
-       lfsck_object_put(env, parent);
+       if (parent != NULL && !IS_ERR(parent))
+               lfsck_object_put(env, parent);
+
+       return rc;
+}
+
+static int
+lfsck_layout_double_scan_one_trace_file(const struct lu_env *env,
+                                       struct lfsck_component *com,
+                                       struct dt_object *obj, bool first)
+{
+       struct lfsck_instance *lfsck = com->lc_lfsck;
+       struct ptlrpc_thread *thread = &lfsck->li_thread;
+       struct lfsck_bookmark *bk = &lfsck->li_bookmark_ram;
+       struct lfsck_layout *lo = com->lc_file_ram;
+       const struct dt_it_ops *iops = &obj->do_index_ops->dio_it;
+       struct dt_it *di;
+       struct dt_key *key;
+       struct lu_fid *pfid = &lfsck_env_info(env)->lti_fid3;
+       struct lu_fid *cfid = &lfsck_env_info(env)->lti_fid4;
+       __u32 ea_off;
+       __u32 ost_idx;
+       int rc;
+       ENTRY;
+
+       di = iops->init(env, obj, 0);
+       if (IS_ERR(di))
+               RETURN(PTR_ERR(di));
+
+       if (first)
+               fid_cpu_to_be(pfid, &lo->ll_fid_latest_scanned_phase2);
+       else
+               fid_zero(pfid);
+       rc = iops->get(env, di, (const struct dt_key *)pfid);
+       if (rc < 0)
+               GOTO(fini, rc);
+
+       if (first) {
+               /* The start one either has been processed or does not exist,
+                * skip it. */
+               rc = iops->next(env, di);
+               if (rc != 0)
+                       GOTO(put, rc);
+       }
+
+       do {
+               if (CFS_FAIL_TIMEOUT(OBD_FAIL_LFSCK_DELAY3, cfs_fail_val) &&
+                   unlikely(!thread_is_running(thread)))
+                       GOTO(put, rc = 0);
+
+               key = iops->key(env, di);
+               if (IS_ERR(key)) {
+                       rc = PTR_ERR(key);
+                       if (rc == -ENOENT)
+                               GOTO(put, rc = 1);
+
+                       goto checkpoint;
+               }
+
+               fid_be_to_cpu(pfid, (const struct lu_fid *)key);
+               ea_off = pfid->f_ver;
+               pfid->f_ver = 0;
+               if (!fid_is_sane(pfid)) {
+                       rc = 0;
+                       goto checkpoint;
+               }
+
+               rc = iops->rec(env, di, (struct dt_rec *)cfid, 0);
+               if (rc == 0) {
+                       fid_be_to_cpu(cfid, cfid);
+                       ost_idx = cfid->f_ver;
+                       cfid->f_ver = 0;
+                       if (!fid_is_sane(cfid)) {
+                               rc = 0;
+                               goto checkpoint;
+                       }
+
+                       rc = lfsck_layout_repair_dangling(env, com, pfid, cfid,
+                                                         ea_off, ost_idx);
+               }
+
+checkpoint:
+               down_write(&com->lc_sem);
+               com->lc_new_checked++;
+               com->lc_new_scanned++;
+               if (rc >= 0)
+                       lo->ll_fid_latest_scanned_phase2 = *pfid;
+
+               if (rc > 0)
+                       lo->ll_objs_repaired[LLIT_DANGLING - 1]++;
+               else if (rc < 0)
+                       lo->ll_objs_failed_phase2++;
+               up_write(&com->lc_sem);
+
+               if (rc < 0 && bk->lb_param & LPF_FAILOUT)
+                       GOTO(put, rc);
+
+               if (unlikely(cfs_time_beforeq(com->lc_time_next_checkpoint,
+                                             cfs_time_current())) &&
+                   com->lc_new_checked != 0) {
+                       down_write(&com->lc_sem);
+                       lo->ll_run_time_phase2 +=
+                               cfs_duration_sec(cfs_time_current() +
+                               HALF_SEC - com->lc_time_last_checkpoint);
+                       lo->ll_time_last_checkpoint = cfs_time_current_sec();
+                       lo->ll_objs_checked_phase2 += com->lc_new_checked;
+                       com->lc_new_checked = 0;
+                       lfsck_layout_store(env, com);
+                       up_write(&com->lc_sem);
+
+                       com->lc_time_last_checkpoint = cfs_time_current();
+                       com->lc_time_next_checkpoint =
+                               com->lc_time_last_checkpoint +
+                               cfs_time_seconds(LFSCK_CHECKPOINT_INTERVAL);
+               }
+
+               lfsck_control_speed_by_self(com);
+               if (unlikely(!thread_is_running(thread)))
+                       GOTO(put, rc = 0);
+
+               rc = iops->next(env, di);
+       } while (rc == 0);
+
+       GOTO(put, rc);
+
+put:
+       iops->put(env, di);
+
+fini:
+       iops->fini(env, di);
 
        return rc;
 }
@@ -3441,7 +3796,7 @@ static int lfsck_layout_assistant_handler_p2(const struct lu_env *env,
                                 struct lfsck_tgt_desc,
                                 ltd_layout_phase_list);
                list_del_init(&ltd->ltd_layout_phase_list);
-               if (bk->lb_param & LPF_ALL_TGT) {
+               if (bk->lb_param & LPF_OST_ORPHAN) {
                        spin_unlock(&ltds->ltd_lock);
                        rc = lfsck_layout_scan_orphan(env, com, ltd);
                        if (rc != 0 && bk->lb_param & LPF_FAILOUT)
@@ -3460,6 +3815,29 @@ static int lfsck_layout_assistant_handler_p2(const struct lu_env *env,
                rc = 0;
        spin_unlock(&ltds->ltd_lock);
 
+       if (rc == 1 && bk->lb_param & LPF_OST_ORPHAN) {
+               struct lfsck_layout *lo = com->lc_file_ram;
+               int i;
+
+               com->lc_new_checked = 0;
+               com->lc_new_scanned = 0;
+               com->lc_time_last_checkpoint = cfs_time_current();
+               com->lc_time_next_checkpoint = com->lc_time_last_checkpoint +
+                               cfs_time_seconds(LFSCK_CHECKPOINT_INTERVAL);
+
+               i = lfsck_sub_trace_file_fid2idx(
+                               &lo->ll_fid_latest_scanned_phase2);
+               rc = lfsck_layout_double_scan_one_trace_file(env, com,
+                               com->lc_sub_trace_objs[i].lsto_obj, true);
+               while (rc > 0 && ++i < LFSCK_STF_COUNT)
+                       rc = lfsck_layout_double_scan_one_trace_file(env, com,
+                               com->lc_sub_trace_objs[i].lsto_obj, false);
+
+               CDEBUG(D_LFSCK, "%s: layout LFSCK phase2 scan dangling stop "
+                      "at the No. %d trace file: rc = %d\n",
+                      lfsck_lfsck2name(lfsck), i, rc);
+       }
+
        CDEBUG(D_LFSCK, "%s: layout LFSCK phase2 scan stop: rc = %d\n",
               lfsck_lfsck2name(lfsck), rc);
 
@@ -3480,11 +3858,22 @@ lfsck_layout_slave_async_interpret(const struct lu_env *env,
        bool                                  done  = false;
 
        if (rc != 0) {
-               /* It is quite probably caused by target crash,
-                * to make the LFSCK can go ahead, assume that
-                * the target finished the LFSCK prcoessing. */
-               done = true;
+               /* It is probably caused by network trouble, or target crash,
+                * it will try several times (depends on the obd_timeout, and
+                * will not less than 3 times). But to make the LFSCK can go
+                * ahead, we should not try for ever. After some try but still
+                * hit failure, it will assume that the target exit the LFSCK
+                * prcoessing and stop try. */
+               if (rc == -ENOTCONN || rc == -ESHUTDOWN) {
+                       int max_try = max_t(int, obd_timeout / 30, 3);
+
+                       if (++(llst->llst_failures) > max_try)
+                               done = true;
+               } else {
+                       done = true;
+               }
        } else {
+               llst->llst_failures = 0;
                lr = req_capsule_server_get(&req->rq_pill, &RMF_LFSCK_REPLY);
                if (lr->lr_status != LS_SCANNING_PHASE1 &&
                    lr->lr_status != LS_SCANNING_PHASE2)
@@ -3493,8 +3882,9 @@ lfsck_layout_slave_async_interpret(const struct lu_env *env,
 
        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);
+                      "status %d, failures_try %d\n", lfsck_lfsck2name(com->lc_lfsck),
+                      llst->llst_index, lr != NULL ? lr->lr_status : rc,
+                      llst->llst_failures);
 
                lfsck_layout_llst_del(llsd, llst);
        }
@@ -3538,6 +3928,7 @@ static int lfsck_layout_async_query(const struct lu_env *env,
        llsaa->llsaa_com = lfsck_component_get(com);
        llsaa->llsaa_llst = llst;
        req->rq_interpret_reply = lfsck_layout_slave_async_interpret;
+       req->rq_allow_intr = 1;
        ptlrpc_set_add_req(set, req);
 
        RETURN(0);
@@ -3566,6 +3957,7 @@ static int lfsck_layout_async_notify(const struct lu_env *env,
        tmp = req_capsule_client_get(&req->rq_pill, &RMF_LFSCK_REQUEST);
        *tmp = *lr;
        ptlrpc_request_set_replen(req);
+       req->rq_allow_intr = 1;
        ptlrpc_set_add_req(set, req);
 
        RETURN(0);
@@ -3941,6 +4333,9 @@ static int lfsck_layout_reset(const struct lu_env *env,
        }
 
        rc = lfsck_layout_store(env, com);
+       if (rc == 0 && com->lc_lfsck->li_master)
+               rc = lfsck_load_sub_trace_files(env, com,
+                       &dt_lfsck_layout_dangling_features, LFSCK_LAYOUT, true);
        up_write(&com->lc_sem);
 
        CDEBUG(D_LFSCK, "%s: layout LFSCK reset: rc = %d\n",
@@ -3992,8 +4387,8 @@ static int lfsck_layout_master_checkpoint(const struct lu_env *env,
        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);
+              "%llu], status = %d: rc = %d\n", lfsck_lfsck2name(lfsck),
+              lfsck->li_pos_current.lp_oit_cookie, lo->ll_status, rc);
 
        return rc;
 }
@@ -4026,8 +4421,8 @@ static int lfsck_layout_slave_checkpoint(const struct lu_env *env,
        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);
+              "%llu], status = %d: rc = %d\n", lfsck_lfsck2name(lfsck),
+              lfsck->li_pos_current.lp_oit_cookie, lo->ll_status, rc);
 
        return rc;
 }
@@ -4135,7 +4530,7 @@ static int lfsck_layout_slave_prep(const struct lu_env *env,
        }
 
        CDEBUG(D_LFSCK, "%s: layout LFSCK slave prep done, start pos ["
-              LPU64"]\n", lfsck_lfsck2name(lfsck),
+              "%llu]\n", lfsck_lfsck2name(lfsck),
               com->lc_pos_start.lp_oit_cookie);
 
        return rc;
@@ -4169,7 +4564,7 @@ static int lfsck_layout_master_prep(const struct lu_env *env,
 
 log:
        CDEBUG(D_LFSCK, "%s: layout LFSCK master prep done, start pos ["
-              LPU64"]\n", lfsck_lfsck2name(com->lc_lfsck),
+              "%llu]\n", lfsck_lfsck2name(com->lc_lfsck),
               com->lc_pos_start.lp_oit_cookie);
 
        return 0;
@@ -4186,7 +4581,7 @@ static int lfsck_layout_scan_stripes(const struct lu_env *env,
        struct lfsck_bookmark           *bk      = &lfsck->li_bookmark_ram;
        struct lfsck_layout             *lo      = com->lc_file_ram;
        struct lfsck_assistant_data     *lad     = com->lc_data;
-       struct lfsck_layout_object      *llo     = NULL;
+       struct lfsck_assistant_object   *lso     = NULL;
        struct lov_ost_data_v1          *objs;
        struct lfsck_tgt_descs          *ltds    = &lfsck->li_ost_descs;
        struct ptlrpc_thread            *mthread = &lfsck->li_thread;
@@ -4300,26 +4695,36 @@ static int lfsck_layout_scan_stripes(const struct lu_env *env,
                        goto next;
                }
 
-               rc = dt_declare_attr_get(env, cobj);
-               if (rc != 0)
-                       goto next;
+               if (!OBD_FAIL_CHECK(OBD_FAIL_LFSCK_ASSISTANT_DIRECT)) {
+                       rc = dt_declare_attr_get(env, cobj);
+                       if (rc != 0)
+                               goto next;
 
-               rc = dt_declare_xattr_get(env, cobj, &buf, XATTR_NAME_FID);
-               if (rc != 0)
-                       goto next;
+                       rc = dt_declare_xattr_get(env, cobj, &buf,
+                                                 XATTR_NAME_FID);
+                       if (rc != 0)
+                               goto next;
+               }
+
+               if (lso == NULL) {
+                       struct lu_attr *attr = &info->lti_la;
+
+                       rc = dt_attr_get(env, parent, attr);
+                       if (rc != 0)
+                               goto next;
+
+                       lso = lfsck_assistant_object_init(env,
+                               lfsck_dto2fid(parent), attr,
+                               lfsck->li_pos_current.lp_oit_cookie, false);
+                       if (IS_ERR(lso)) {
+                               rc = PTR_ERR(lso);
+                               lso = NULL;
 
-               if (llo == NULL) {
-                       llo = lfsck_layout_object_init(env, parent,
-                               lfsck->li_pos_current.lp_oit_cookie);
-                       if (IS_ERR(llo)) {
-                               rc = PTR_ERR(llo);
                                goto next;
                        }
                }
 
-               llr = lfsck_layout_assistant_req_init(llo,
-                                                     lfsck_dto2fid(parent),
-                                                     cobj, index, i);
+               llr = lfsck_layout_assistant_req_init(lso, cobj, index, i);
                if (IS_ERR(llr)) {
                        rc = PTR_ERR(llr);
                        goto next;
@@ -4363,8 +4768,8 @@ next:
        GOTO(out, rc = 0);
 
 out:
-       if (llo != NULL && !IS_ERR(llo))
-               lfsck_layout_object_put(env, llo);
+       if (lso != NULL)
+               lfsck_assistant_object_put(env, lso);
 
        return rc;
 }
@@ -4561,7 +4966,7 @@ static int lfsck_layout_slave_exec_oit(const struct lu_env *env,
                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",
+                             "load LAST_ID for %#llx: rc = %d\n",
                              lfsck_lfsck2name(com->lc_lfsck), seq, rc);
                        lo->ll_objs_failed_phase1++;
                        OBD_FREE_PTR(lls);
@@ -4588,7 +4993,7 @@ static int lfsck_layout_slave_exec_oit(const struct lu_env *env,
                        rc = lfsck_layout_lastid_reload(env, com, lls);
                        if (unlikely(rc != 0)) {
                                CDEBUG(D_LFSCK, "%s: layout LFSCK failed to "
-                                     "reload LAST_ID for "LPX64": rc = %d\n",
+                                     "reload LAST_ID for %#llx: rc = %d\n",
                                      lfsck_lfsck2name(com->lc_lfsck),
                                      lls->lls_seq, rc);
 
@@ -4606,8 +5011,8 @@ static int lfsck_layout_slave_exec_oit(const struct lu_env *env,
                        lo->ll_flags |= LF_CRASHED_LASTID;
 
                        CDEBUG(D_LFSCK, "%s: layout LFSCK finds crashed "
-                              "LAST_ID file (2) for the sequence "LPX64
-                              ", old value "LPU64", known value "LPU64"\n",
+                              "LAST_ID file (2) for the sequence %#llx"
+                              ", old value %llu, known value %llu\n",
                               lfsck_lfsck2name(lfsck), lls->lls_seq,
                               lls->lls_lastid, oid);
                }
@@ -4626,6 +5031,7 @@ unlock:
 
 static int lfsck_layout_exec_dir(const struct lu_env *env,
                                 struct lfsck_component *com,
+                                struct lfsck_assistant_object *lso,
                                 struct lu_dirent *ent, __u16 type)
 {
        return 0;
@@ -4695,13 +5101,13 @@ static int lfsck_layout_slave_post(const struct lu_env *env,
        int                      rc;
        bool                     done  = false;
 
+       down_write(&com->lc_sem);
        rc = lfsck_layout_lastid_store(env, com);
        if (rc != 0)
                result = rc;
 
        LASSERT(lfsck->li_out_notify != NULL);
 
-       down_write(&com->lc_sem);
        spin_lock(&lfsck->li_lock);
        if (!init)
                lo->ll_pos_last_checkpoint =
@@ -4756,77 +5162,62 @@ static int lfsck_layout_slave_post(const struct lu_env *env,
        return rc;
 }
 
-static int lfsck_layout_dump(const struct lu_env *env,
-                            struct lfsck_component *com, struct seq_file *m)
+static void lfsck_layout_dump(const struct lu_env *env,
+                             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                      rc;
 
        down_read(&com->lc_sem);
        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));
-
-       rc = lfsck_bits_dump(m, lo->ll_flags, lfsck_flags_names, "flags");
-       if (rc < 0)
-               goto out;
+                  "magic: %#x\n"
+                  "version: %d\n"
+                  "status: %s\n",
+                  lo->ll_magic,
+                  bk->lb_version,
+                  lfsck_status2name(lo->ll_status));
 
-       rc = lfsck_bits_dump(m, bk->lb_param, lfsck_param_names, "param");
-       if (rc < 0)
-               goto out;
+       lfsck_bits_dump(m, lo->ll_flags, lfsck_flags_names, "flags");
 
-       rc = lfsck_time_dump(m, lo->ll_time_last_complete,
-                            "last_completed");
-       if (rc < 0)
-               goto out;
+       lfsck_bits_dump(m, bk->lb_param, lfsck_param_names, "param");
 
-       rc = lfsck_time_dump(m, lo->ll_time_latest_start,
-                            "latest_start");
-       if (rc < 0)
-               goto out;
+       lfsck_time_dump(m, lo->ll_time_last_complete, "last_completed");
 
-       rc = lfsck_time_dump(m, lo->ll_time_last_checkpoint,
-                            "last_checkpoint");
-       if (rc < 0)
-               goto out;
+       lfsck_time_dump(m, lo->ll_time_latest_start, "latest_start");
+
+       lfsck_time_dump(m, lo->ll_time_last_checkpoint, "last_checkpoint");
 
-       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);
+       seq_printf(m, "latest_start_position: %llu\n"
+                  "last_checkpoint_position: %llu\n"
+                  "first_failure_position: %llu\n",
+                  lo->ll_pos_latest_start,
+                  lo->ll_pos_last_checkpoint,
+                  lo->ll_pos_first_inconsistent);
 
        seq_printf(m, "success_count: %u\n"
-                     "repaired_dangling: "LPU64"\n"
-                     "repaired_unmatched_pair: "LPU64"\n"
-                     "repaired_multiple_referenced: "LPU64"\n"
-                     "repaired_orphan: "LPU64"\n"
-                     "repaired_inconsistent_owner: "LPU64"\n"
-                     "repaired_others: "LPU64"\n"
-                     "skipped: "LPU64"\n"
-                     "failed_phase1: "LPU64"\n"
-                     "failed_phase2: "LPU64"\n",
-                     lo->ll_success_count,
-                     lo->ll_objs_repaired[LLIT_DANGLING - 1],
-                     lo->ll_objs_repaired[LLIT_UNMATCHED_PAIR - 1],
-                     lo->ll_objs_repaired[LLIT_MULTIPLE_REFERENCED - 1],
-                     lo->ll_objs_repaired[LLIT_ORPHAN - 1],
-                     lo->ll_objs_repaired[LLIT_INCONSISTENT_OWNER - 1],
-                     lo->ll_objs_repaired[LLIT_OTHERS - 1],
-                     lo->ll_objs_skipped,
-                     lo->ll_objs_failed_phase1,
-                     lo->ll_objs_failed_phase2);
+                  "repaired_dangling: %llu\n"
+                  "repaired_unmatched_pair: %llu\n"
+                  "repaired_multiple_referenced: %llu\n"
+                  "repaired_orphan: %llu\n"
+                  "repaired_inconsistent_owner: %llu\n"
+                  "repaired_others: %llu\n"
+                  "skipped: %llu\n"
+                  "failed_phase1: %llu\n"
+                  "failed_phase2: %llu\n",
+                  lo->ll_success_count,
+                  lo->ll_objs_repaired[LLIT_DANGLING - 1],
+                  lo->ll_objs_repaired[LLIT_UNMATCHED_PAIR - 1],
+                  lo->ll_objs_repaired[LLIT_MULTIPLE_REFERENCED - 1],
+                  lo->ll_objs_repaired[LLIT_ORPHAN - 1],
+                  lo->ll_objs_repaired[LLIT_INCONSISTENT_OWNER - 1],
+                  lo->ll_objs_repaired[LLIT_OTHERS - 1],
+                  lo->ll_objs_skipped,
+                  lo->ll_objs_failed_phase1,
+                  lo->ll_objs_failed_phase2);
 
        if (lo->ll_status == LS_SCANNING_PHASE1) {
                __u64 pos;
-               const struct dt_it_ops *iops;
                cfs_duration_t duration = cfs_time_current() -
                                          lfsck->li_time_last_checkpoint;
                __u64 checked = lo->ll_objs_checked_phase1 +
@@ -4841,37 +5232,40 @@ static int lfsck_layout_dump(const struct lu_env *env,
                        do_div(new_checked, duration);
                if (rtime != 0)
                        do_div(speed, rtime);
-               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: N/A\n"
-                             "real-time_speed_phase1: "LPU64" items/sec\n"
-                             "real-time_speed_phase2: N/A\n",
-                             checked,
-                             lo->ll_objs_checked_phase2,
-                             rtime,
-                             lo->ll_run_time_phase2,
-                             speed,
-                             new_checked);
-
-               LASSERT(lfsck->li_di_oit != NULL);
-
-               iops = &lfsck->li_obj_oit->do_index_ops->dio_it;
-
-               /* The low layer otable-based iteration position may NOT
-                * exactly match the layout-based directory traversal
-                * cookie. Generally, it is not a serious issue. But the
-                * caller should NOT make assumption on that. */
-               pos = iops->store(env, lfsck->li_di_oit);
-               if (!lfsck->li_current_oit_processed)
-                       pos--;
-               seq_printf(m, "current_position: "LPU64"\n", pos);
+               seq_printf(m, "checked_phase1: %llu\n"
+                          "checked_phase2: %llu\n"
+                          "run_time_phase1: %u seconds\n"
+                          "run_time_phase2: %u seconds\n"
+                          "average_speed_phase1: %llu items/sec\n"
+                          "average_speed_phase2: N/A\n"
+                          "real-time_speed_phase1: %llu items/sec\n"
+                          "real-time_speed_phase2: N/A\n",
+                          checked,
+                          lo->ll_objs_checked_phase2,
+                          rtime,
+                          lo->ll_run_time_phase2,
+                          speed,
+                          new_checked);
+
+               if (likely(lfsck->li_di_oit)) {
+                       const struct dt_it_ops *iops =
+                               &lfsck->li_obj_oit->do_index_ops->dio_it;
+
+                       /* The low layer otable-based iteration position may NOT
+                        * exactly match the layout-based directory traversal
+                        * cookie. Generally, it is not a serious issue. But the
+                        * caller should NOT make assumption on that. */
+                       pos = iops->store(env, lfsck->li_di_oit);
+                       if (!lfsck->li_current_oit_processed)
+                               pos--;
+               } else {
+                       pos = lo->ll_pos_last_checkpoint;
+               }
 
+               seq_printf(m, "current_position: %llu\n", pos);
        } else if (lo->ll_status == LS_SCANNING_PHASE2) {
                cfs_duration_t duration = cfs_time_current() -
-                                         lfsck->li_time_last_checkpoint;
+                                         com->lc_time_last_checkpoint;
                __u64 checked = lo->ll_objs_checked_phase2 +
                                com->lc_new_checked;
                __u64 speed1 = lo->ll_objs_checked_phase1;
@@ -4887,26 +5281,23 @@ 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 = 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;
-
+               seq_printf(m, "checked_phase1: %llu\n"
+                          "checked_phase2: %llu\n"
+                          "run_time_phase1: %u seconds\n"
+                          "run_time_phase2: %u seconds\n"
+                          "average_speed_phase1: %llu items/sec\n"
+                          "average_speed_phase2: %llu items/sec\n"
+                          "real-time_speed_phase1: N/A\n"
+                          "real-time_speed_phase2: %llu 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));
        } else {
                __u64 speed1 = lo->ll_objs_checked_phase1;
                __u64 speed2 = lo->ll_objs_checked_phase2;
@@ -4915,12 +5306,12 @@ 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);
-               seq_printf(m, "checked_phase1: "LPU64"\n"
-                          "checked_phase2: "LPU64"\n"
+               seq_printf(m, "checked_phase1: %llu\n"
+                          "checked_phase2: %llu\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"
+                          "average_speed_phase1: %llu items/sec\n"
+                          "average_speed_phase2: %llu objs/sec\n"
                           "real-time_speed_phase1: N/A\n"
                           "real-time_speed_phase2: N/A\n"
                           "current_position: N/A\n",
@@ -4931,10 +5322,8 @@ static int lfsck_layout_dump(const struct lu_env *env,
                           speed1,
                           speed2);
        }
-out:
-       up_read(&com->lc_sem);
 
-       return rc;
+       up_read(&com->lc_sem);
 }
 
 static int lfsck_layout_master_double_scan(const struct lu_env *env,
@@ -5164,12 +5553,14 @@ static void lfsck_layout_slave_quit(const struct lu_env *env,
 
        LASSERT(llsd != NULL);
 
+       down_write(&com->lc_sem);
        list_for_each_entry_safe(lls, next, &llsd->llsd_seq_list,
                                 lls_list) {
                list_del_init(&lls->lls_list);
                lfsck_object_put(env, lls->lls_lastid_obj);
                OBD_FREE_PTR(lls);
        }
+       up_write(&com->lc_sem);
 
        spin_lock(&llsd->llsd_lock);
        while (!list_empty(&llsd->llsd_master_list)) {
@@ -5223,7 +5614,7 @@ static int lfsck_layout_master_in_notify(const struct lu_env *env,
        else
                ltds = &lfsck->li_mdt_descs;
        spin_lock(&ltds->ltd_lock);
-       ltd = LTD_TGT(ltds, lr->lr_index);
+       ltd = lfsck_ltd2tgt(ltds, lr->lr_index);
        if (ltd == NULL) {
                spin_unlock(&ltds->ltd_lock);
 
@@ -5400,12 +5791,85 @@ static int lfsck_layout_slave_in_notify(const struct lu_env *env,
        RETURN(0);
 }
 
+static void lfsck_layout_repaired(struct lfsck_layout *lo, __u64 *count)
+{
+       int i;
+
+       for (i = 0; i < LLIT_MAX; i++)
+               *count += lo->ll_objs_repaired[i];
+}
+
+static int lfsck_layout_query_all(const struct lu_env *env,
+                                 struct lfsck_component *com,
+                                 __u32 *mdts_count, __u32 *osts_count,
+                                 __u64 *repaired)
+{
+       struct lfsck_layout *lo = com->lc_file_ram;
+       struct lfsck_tgt_descs *ltds;
+       struct lfsck_tgt_desc *ltd;
+       int idx;
+       int rc;
+       ENTRY;
+
+       rc = lfsck_query_all(env, com);
+       if (rc != 0)
+               RETURN(rc);
+
+       ltds = &com->lc_lfsck->li_mdt_descs;
+       down_read(&ltds->ltd_rw_sem);
+       cfs_foreach_bit(ltds->ltd_tgts_bitmap, idx) {
+               ltd = lfsck_ltd2tgt(ltds, idx);
+               LASSERT(ltd != NULL);
+
+               mdts_count[ltd->ltd_layout_status]++;
+               *repaired += ltd->ltd_layout_repaired;
+       }
+       up_read(&ltds->ltd_rw_sem);
+
+       ltds = &com->lc_lfsck->li_ost_descs;
+       down_read(&ltds->ltd_rw_sem);
+       cfs_foreach_bit(ltds->ltd_tgts_bitmap, idx) {
+               ltd = lfsck_ltd2tgt(ltds, idx);
+               LASSERT(ltd != NULL);
+
+               osts_count[ltd->ltd_layout_status]++;
+               *repaired += ltd->ltd_layout_repaired;
+       }
+       up_read(&ltds->ltd_rw_sem);
+
+       down_read(&com->lc_sem);
+       mdts_count[lo->ll_status]++;
+       lfsck_layout_repaired(lo, repaired);
+       up_read(&com->lc_sem);
+
+       RETURN(0);
+}
+
 static int lfsck_layout_query(const struct lu_env *env,
-                             struct lfsck_component *com)
+                             struct lfsck_component *com,
+                             struct lfsck_request *req,
+                             struct lfsck_reply *rep,
+                             struct lfsck_query *que, int idx)
 {
        struct lfsck_layout *lo = com->lc_file_ram;
+       int rc = 0;
+
+       if (que != NULL) {
+               LASSERT(com->lc_lfsck->li_master);
+
+               rc = lfsck_layout_query_all(env, com,
+                                           que->lu_mdts_count[idx],
+                                           que->lu_osts_count[idx],
+                                           &que->lu_repaired[idx]);
+       } else {
+               down_read(&com->lc_sem);
+               rep->lr_status = lo->ll_status;
+               if (req->lr_flags & LEF_QUERY_ALL)
+                       lfsck_layout_repaired(lo, &rep->lr_repaired);
+               up_read(&com->lc_sem);
+       }
 
-       return lo->ll_status;
+       return rc;
 }
 
 /* with lfsck::li_lock held */
@@ -5488,13 +5952,17 @@ static void lfsck_layout_assistant_fill_pos(const struct lu_env *env,
        struct lfsck_assistant_data     *lad = com->lc_data;
        struct lfsck_layout_req         *llr;
 
+       if (((struct lfsck_layout *)(com->lc_file_ram))->ll_status !=
+           LS_SCANNING_PHASE1)
+               return;
+
        if (list_empty(&lad->lad_req_list))
                return;
 
        llr = list_entry(lad->lad_req_list.next,
                         struct lfsck_layout_req,
                         llr_lar.lar_list);
-       pos->lp_oit_cookie = llr->llr_parent->llo_cookie - 1;
+       pos->lp_oit_cookie = llr->llr_lar.lar_parent->lso_oit_cookie - 1;
 }
 
 struct lfsck_assistant_operations lfsck_layout_assistant_ops = {
@@ -5512,6 +5980,7 @@ int lfsck_layout_setup(const struct lu_env *env, struct lfsck_instance *lfsck)
        struct lfsck_layout     *lo;
        struct dt_object        *root = NULL;
        struct dt_object        *obj;
+       int                      i;
        int                      rc;
        ENTRY;
 
@@ -5532,6 +6001,9 @@ int lfsck_layout_setup(const struct lu_env *env, struct lfsck_instance *lfsck)
                                LFSCK_LAYOUT);
                if (com->lc_data == NULL)
                        GOTO(out, rc = -ENOMEM);
+
+               for (i = 0; i < LFSCK_STF_COUNT; i++)
+                       mutex_init(&com->lc_sub_trace_objs[i].lsto_mutex);
        } else {
                struct lfsck_layout_slave_data *llsd;
 
@@ -5575,6 +6047,10 @@ int lfsck_layout_setup(const struct lu_env *env, struct lfsck_instance *lfsck)
                rc = lfsck_layout_reset(env, com, true);
        else if (rc == -ENOENT)
                rc = lfsck_layout_init(env, com);
+       else if (lfsck->li_master)
+               rc = lfsck_load_sub_trace_files(env, com,
+                               &dt_lfsck_layout_dangling_features,
+                               LFSCK_LAYOUT, false);
 
        if (rc != 0)
                GOTO(out, rc);
@@ -6169,9 +6645,9 @@ static int lfsck_orphan_it_load(const struct lu_env *env,
        LASSERT(llst != NULL);
 
        if (hash != llst->llst_hash) {
-               CDEBUG(D_LFSCK, "%s: the given hash "LPU64" for orphan "
+               CDEBUG(D_LFSCK, "%s: the given hash %llu for orphan "
                       "iteration does not match the one when fini "
-                      LPU64", to be reset.\n",
+                      "%llu, to be reset.\n",
                       lfsck_lfsck2name(it->loi_com->lc_lfsck), hash,
                       llst->llst_hash);
                fid_zero(&llst->llst_fid);